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Pollution characteristics and ecological risk assessment of 11 unheeded metals in sediments of the Chinese Xiangjiang River.
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With the change in global climate and environment, water scarcity has been of great concern around the word and exacerbated by serious pollution in water resources. Pollutants accumulated in sediments are threatening water safety and ecological security. Different from others focusing on prevalent heavy metals (Cu, Pb, Zn, As, Cd, Cr, Hg, etc.), in this study, some unheeded metal pollutants Tl, Sb, Mo, Sr, Co, V, Ti, Ca, Mg, Be and Li were monitored in sediments of the Xiangjiang River, China. It was found that there was no remarkable vertical variation with depth, but the seasonal characteristics of Tl, Sb, Mo, Be and Li. The enrichment, pollution and potential ecological risk of Tl, Sb and Mo were revealed by the enrichment factor (EF), geoaccumulation index (I<sub>geo</sub>), pollution load index (PLI<sub>site</sub> and PLI<sub>zone</sub>) and potential ecological risk index (RI). It is noticed that the pollution of Tl mainly occurred in summer at midstream and downstream and Mo pollution was much higher than Sb in summer and the reverse in other seasons. Additionally, sediment quality on east side was worse than on west side in Songbai section of the Xiangjiang River. For the first time, the toxic-response factor was figured out as Mo = 18, Tl = 17, Sb = 13, Sr = 6, Co = Be = 1, V = Li = 0, and importantly, the high potential ecological risk of Tl, Sb and Mo needs to be taken seriously for the comprehensive assessment on watershed environmental quality.
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Several heavy metals, including Cu, Zn, Cr, Ni, Pb, and Cd, were investigated at 80 sampling sites in the southern and central areas of Haihe River Basin. The spatial patterns and potential anthropogenic impacts of heavy metals were evaluated by several methods, such as the potential ecological risk index and enrichment factors (EFs). Results showed that, (1) The concentrations of heavy metals in the sediments were higher than the background values in most sites except for Cr, Ni. The concentration of Cd was 2.64 times higher than its background value. Based on the potential ecological risk index for single heavy metal, Cd in river sediments showed a high potential ecological risk while the other elements showed a slight potential ecological risk at most sampling sites. Generally, the decreasing order of the heavy metals was Cd > Cu > Pb > Ni > Cr > Zn. (2) The concentration of heavy metals in surface sediment varied in different regions. The concentration of heavy metals and the potential ecological risks were higher in the Ziya river (RI = 155. 64) and Daqing river (RI = 111.84) than those in the other rivers. For example, slight pollution of heavy metals was found in the Tuhai, Majia river (RI = 69. 54) and Heilonggang river (RI = 84. 50) due to a relatively low level of industrialization. (3) Cd, Pb, Zn, Cr were positively correlated with each other and might be derived from similar sources. The increasing order of anthropogenic impacts on heavy metals was Ni < Cr < Cu < Zn < Pb < Cd according to the calculated EFs. The anthropogenic impacts differed in different rivers. For example, strong impacts were found in the Ziya, Daqing, Yongding and Zhangwei rivers whereas weak impacts were showed in Tuhai, Majia and Heilonggang rivers.
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Pollution characteristics and ecological risk assessment of 11 unheeded metals in sediments of the Chinese Xiangjiang River.
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With the change in global climate and environment, water scarcity has been of great concern around the word and exacerbated by serious pollution in water resources. Pollutants accumulated in sediments are threatening water safety and ecological security. Different from others focusing on prevalent heavy metals (Cu, Pb, Zn, As, Cd, Cr, Hg, etc.), in this study, some unheeded metal pollutants Tl, Sb, Mo, Sr, Co, V, Ti, Ca, Mg, Be and Li were monitored in sediments of the Xiangjiang River, China. It was found that there was no remarkable vertical variation with depth, but the seasonal characteristics of Tl, Sb, Mo, Be and Li. The enrichment, pollution and potential ecological risk of Tl, Sb and Mo were revealed by the enrichment factor (EF), geoaccumulation index (I<sub>geo</sub>), pollution load index (PLI<sub>site</sub> and PLI<sub>zone</sub>) and potential ecological risk index (RI). It is noticed that the pollution of Tl mainly occurred in summer at midstream and downstream and Mo pollution was much higher than Sb in summer and the reverse in other seasons. Additionally, sediment quality on east side was worse than on west side in Songbai section of the Xiangjiang River. For the first time, the toxic-response factor was figured out as Mo = 18, Tl = 17, Sb = 13, Sr = 6, Co = Be = 1, V = Li = 0, and importantly, the high potential ecological risk of Tl, Sb and Mo needs to be taken seriously for the comprehensive assessment on watershed environmental quality.
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The Le'an River is a main tributary of the Poyang Lake, which is the largest freshwater lake in China. The aim of this study is to research the distribution and potential ecological risks of heavy metals in the middle and lower reaches of the Le'an River, which is contaminated by nearby copper mines. Sediment and water samples were collected from 12 stations during the dry, wet, and normal season in 2016, respectively. The geo-accumulation index and potential ecological risk index were used to determine general pollution characteristics of trace metals in sediments. Results suggested that sediments in the Le'an River were considerably polluted by Cd, Pb, Cu, and Zn. Sediment concentrations of heavy metals showed significant spatial variations. The concentrations of heavy metals such as Cu, Zn, and Cd in water are higher in the dry season than in the normal and wet seasons. The distribution of heavy metals along the river is influenced by hydraulic conditions. The flow velocities in wet and normal seasons are positively correlated with the concentrations of heavy metals such as Cd, Pb, Cu, and Cr. There are seasonal differences in the distribution characteristics of heavy metals in surface sediments. In the dry season, the concentration of heavy metals in sediments is the highest in the middle reaches of rivers near mining areas, while during the wet and normal season, it reaches the highest value in the lower reach near the estuary. Except for Cd, whose major form of heavy metal in the sediment is in an exchanging state, the other heavy metals occur mainly in stable states. The assessment of the geo-accumulation index showed significant Cu, Cd, and Cr pollution. Among the heavy metals investigated, Cd was likely to result in more harmful effects.
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Pollution characteristics and ecological risk assessment of 11 unheeded metals in sediments of the Chinese Xiangjiang River.
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With the change in global climate and environment, water scarcity has been of great concern around the word and exacerbated by serious pollution in water resources. Pollutants accumulated in sediments are threatening water safety and ecological security. Different from others focusing on prevalent heavy metals (Cu, Pb, Zn, As, Cd, Cr, Hg, etc.), in this study, some unheeded metal pollutants Tl, Sb, Mo, Sr, Co, V, Ti, Ca, Mg, Be and Li were monitored in sediments of the Xiangjiang River, China. It was found that there was no remarkable vertical variation with depth, but the seasonal characteristics of Tl, Sb, Mo, Be and Li. The enrichment, pollution and potential ecological risk of Tl, Sb and Mo were revealed by the enrichment factor (EF), geoaccumulation index (I<sub>geo</sub>), pollution load index (PLI<sub>site</sub> and PLI<sub>zone</sub>) and potential ecological risk index (RI). It is noticed that the pollution of Tl mainly occurred in summer at midstream and downstream and Mo pollution was much higher than Sb in summer and the reverse in other seasons. Additionally, sediment quality on east side was worse than on west side in Songbai section of the Xiangjiang River. For the first time, the toxic-response factor was figured out as Mo = 18, Tl = 17, Sb = 13, Sr = 6, Co = Be = 1, V = Li = 0, and importantly, the high potential ecological risk of Tl, Sb and Mo needs to be taken seriously for the comprehensive assessment on watershed environmental quality.
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The particle size, total organic carbon (TOC), total nitrogen (TN), C/N ratio and metal concentrations as well as activities of 210Pb were determined in Liaohe River estuary area (LN-2) and Shenyang area (LN-5), and the organic matter resources were discussed in two core sediments. Also the index of geoaccumulation (Igeo) and enrichment factors (EFs) methods were applied to evaluate the state of heavy metal contamination in the studied sties. The study showed that both sediment cores LN-2 and LN-5 were dominated by silts, and the vertical variations of grain-size composition and organic matter were well distributed in LN- 2 while fluctuated in LN-5. According to the organic matter source analysis through C/N ratio, C/N ratio varied in the scale of 5. 24-7.93 in LN-2 which was dominated by river source, and 9.94-14.21 in LN-5 which was dominated by terrestrial input. Al, Ca, Fe, Mn, Ni, Cu, Zn, Cd, Pb and Cr in two sediment cores had different vertical changing rules, Ni and Zn in LN-2 as well as Pb and Zn in LN-5 were affected by both natural and human factors, other elements had similar distributions to those of organic matters, which showed that these elements were mainly affected by the natural activities. Based on Igeo and EFs, both sediment cores were more severely polluted with Ni, Zn and Pb than other metals. The effects of human activities on the environment were also discussed in this study, combined with the economical development of Liaoning Province and the studied sites in the past 20 years.
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Pollution characteristics and ecological risk assessment of 11 unheeded metals in sediments of the Chinese Xiangjiang River.
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With the change in global climate and environment, water scarcity has been of great concern around the word and exacerbated by serious pollution in water resources. Pollutants accumulated in sediments are threatening water safety and ecological security. Different from others focusing on prevalent heavy metals (Cu, Pb, Zn, As, Cd, Cr, Hg, etc.), in this study, some unheeded metal pollutants Tl, Sb, Mo, Sr, Co, V, Ti, Ca, Mg, Be and Li were monitored in sediments of the Xiangjiang River, China. It was found that there was no remarkable vertical variation with depth, but the seasonal characteristics of Tl, Sb, Mo, Be and Li. The enrichment, pollution and potential ecological risk of Tl, Sb and Mo were revealed by the enrichment factor (EF), geoaccumulation index (I<sub>geo</sub>), pollution load index (PLI<sub>site</sub> and PLI<sub>zone</sub>) and potential ecological risk index (RI). It is noticed that the pollution of Tl mainly occurred in summer at midstream and downstream and Mo pollution was much higher than Sb in summer and the reverse in other seasons. Additionally, sediment quality on east side was worse than on west side in Songbai section of the Xiangjiang River. For the first time, the toxic-response factor was figured out as Mo = 18, Tl = 17, Sb = 13, Sr = 6, Co = Be = 1, V = Li = 0, and importantly, the high potential ecological risk of Tl, Sb and Mo needs to be taken seriously for the comprehensive assessment on watershed environmental quality.
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Sediment column and soil samples collected from 12 sampling sites in four regions of the Ruxi River, a typical tributary of the Three Gorges Reservoir, were analyzed for eight selected heavy metals including Cr, Ni, Cu, Mn, Zn, Cd, Pb, and Hg to evaluate their spatial and vertical distribution, source, and biological toxic effects. The results showed that the average concentrations of heavy metals were (79.60±11.87), (41.340±4.999), (32.69±8.70), (823.34±125.76), (122.11±22.82), (0.393±0.140), and (29.122±6.811) mg·kg<sup>-1</sup> for Cr, Ni, Cu, Mn, Zn, Cd, and Pb, respectively, and (74.84±39.50) μg·kg<sup>-1</sup> for Hg, all of which exceeded the sediment background values of the Yangtze River. A spatial trend of decreasing metal concentrations was observed from the reach influenced by the human activities of Ruxi town to the backwater zone and then to the natural river reach. Moreover, in the backwater zone, the heavy metals in sediments and soil along the river were significantly lower than those in sediments, indicating that the sediments and soil were not one primary source for these metals in backwater zone sediment. From the vertical distribution of sediment, in addition to Pb, the highest level of metals was observed at 8 cm in the reach influenced by human activities, and their concentrations decreased with sediment depth in the backwater zone and natural river beach. Significant correlation was found between all the heavy metals (<i>P</i><0.01, except Ni), indicating a potential homology of these metals in the Ruxi River. Evaluation results of the geoaccumulation index reveal that there exists light to partial moderate Cd and Zn pollution in the Ruxi River. The evaluation of biotoxicity effects showed that Ni was likely to have toxic effects on organisms with a probability of 10% to 75%, and Cd, Zn, Hg, Cu, Pb, and Cr are likely to have biotoxic effects at<10% probability. The combined effect values of multiple metals indicated that the risk of adverse effects was between low and lower medium in the sediments of the Ruxi River.
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Food supply modifies the trade-off between past and future reproduction in a sexual parasite-host system (Rana esculenta, Rana lessonae).
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Life history theory is concerned with the costs of survival, growth and reproduction under different ecological conditions and the allocation of resources to meet these costs. Typical approaches used to address these topics include manipulation of food resources, followed by measures of subsequent reproductive traits, and measures of the relationship between current and future reproductive investment. Rarely, however, do studies test for the interaction of past investment, present resource availability and future investment simultaneously. Here, we investigate this interaction in females of a sexual parasite-host system consisting of the hybridogenetic frog Rana esculenta (E) and one of its parental species Rana lessonae (L). We kept females from each of two groups (with or without previous reproduction) under two food treatments (low or high) and regularly recorded their growth as well as their body condition and hormone titres as measures of future reproductive condition. After keeping them in hibernation until the following spring, we exposed the females to males, recorded whether they spawned or not and related this response to their condition in the previous autumn. Past reproduction negatively affected growth during summer and condition during autumn which, in turn, reduced the following year's reproductive output. These costs of previous reproduction were less pronounced under the high than under the low food treatment and lower in R. lessonae than in R. esculenta. Increasing food supply improved reproductive condition more in L than in E females. These species differences in reproductive costs and food requirements provide a mechanistic explanation for why E females skip annual reproduction almost twice as often as L females. Since R. esculenta is a sexual parasite that depends on R. lessonae for successful reproduction, these species-specific life history patterns not only affect individual fitness but also the spatial structure and temporal dynamics of mixed LE populations.
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Why is sex ubiquitous when asexual reproduction is much less costly? Sex disrupts coadapted gene complexes; it also causes costs associated with mate finding and the production of males who do not themselves bear offspring. Theory predicts parasites select for host sex, because genetically variable offspring can escape infection from parasites adapted to infect the previous generations. We examine this using a facultative sexual crustacean, Daphnia magna, and its sterilizing bacterial parasite, Pasteuria ramosa We obtained sexually and asexually produced offspring from wild-caught hosts and exposed them to contemporary parasites or parasites isolated from the same population one year later. We found rapid parasite adaptation to replicate within asexual but not sexual offspring. Moreover, sexually produced offspring were twice as resistant to infection as asexuals when exposed to parasites that had coevolved alongside their parents (i.e. the year two parasite). This fulfils the requirement that the benefits of sex must be both large and rapid for sex to be favoured by selection.
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Food supply modifies the trade-off between past and future reproduction in a sexual parasite-host system (Rana esculenta, Rana lessonae).
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Life history theory is concerned with the costs of survival, growth and reproduction under different ecological conditions and the allocation of resources to meet these costs. Typical approaches used to address these topics include manipulation of food resources, followed by measures of subsequent reproductive traits, and measures of the relationship between current and future reproductive investment. Rarely, however, do studies test for the interaction of past investment, present resource availability and future investment simultaneously. Here, we investigate this interaction in females of a sexual parasite-host system consisting of the hybridogenetic frog Rana esculenta (E) and one of its parental species Rana lessonae (L). We kept females from each of two groups (with or without previous reproduction) under two food treatments (low or high) and regularly recorded their growth as well as their body condition and hormone titres as measures of future reproductive condition. After keeping them in hibernation until the following spring, we exposed the females to males, recorded whether they spawned or not and related this response to their condition in the previous autumn. Past reproduction negatively affected growth during summer and condition during autumn which, in turn, reduced the following year's reproductive output. These costs of previous reproduction were less pronounced under the high than under the low food treatment and lower in R. lessonae than in R. esculenta. Increasing food supply improved reproductive condition more in L than in E females. These species differences in reproductive costs and food requirements provide a mechanistic explanation for why E females skip annual reproduction almost twice as often as L females. Since R. esculenta is a sexual parasite that depends on R. lessonae for successful reproduction, these species-specific life history patterns not only affect individual fitness but also the spatial structure and temporal dynamics of mixed LE populations.
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Parasites can impact wildlife populations through their effects on host fitness and survival. The life history strategies of a parasite species can dictate the mechanisms and timing through which it influences the host. However, unravelling this species-specific effect is difficult as parasites generally occur as part of a broader community of co-infecting parasites. Here, we use a unique study system to explore how life histories of different abomasal nematode species may influence host fitness. We examined abomasal nematodes in two adjacent, but isolated, West Greenland caribou (Rangifer tarandus groenlandicus) populations. One herd of caribou were naturally infected with Ostertagia gruehneri, a common and dominant summer nematode of Rangifer sspp., and the other with Marshallagia marshalli (abundant; winter) and Teladorsagia boreoarcticus (less abundant; summer), allowing us to determine if these nematode species have differing effects on host fitness. Using a Partial Least Squares Path Modelling approach, we found that in the caribou infected with O. gruehneri, higher infection intensity was associated with lower body condition, and that animals with lower body condition were less likely to be pregnant. In caribou infected with M. marshalli and T. boreoarcticus, we found that only M. marshalli infection intensity was negatively related to body condition and pregnancy, but that caribou with a calf at heel were more likely to have higher infection intensities of both nematode species. The differing effects of abomasal nematode species on caribou health outcomes in these herds may be due to parasite species-specific seasonal patterns which influence both transmission dynamics and when the parasites have the greatest impact on host condition. These results highlight the importance of considering parasite life history when testing associations between parasitic infection and host fitness.
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Food supply modifies the trade-off between past and future reproduction in a sexual parasite-host system (Rana esculenta, Rana lessonae).
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Life history theory is concerned with the costs of survival, growth and reproduction under different ecological conditions and the allocation of resources to meet these costs. Typical approaches used to address these topics include manipulation of food resources, followed by measures of subsequent reproductive traits, and measures of the relationship between current and future reproductive investment. Rarely, however, do studies test for the interaction of past investment, present resource availability and future investment simultaneously. Here, we investigate this interaction in females of a sexual parasite-host system consisting of the hybridogenetic frog Rana esculenta (E) and one of its parental species Rana lessonae (L). We kept females from each of two groups (with or without previous reproduction) under two food treatments (low or high) and regularly recorded their growth as well as their body condition and hormone titres as measures of future reproductive condition. After keeping them in hibernation until the following spring, we exposed the females to males, recorded whether they spawned or not and related this response to their condition in the previous autumn. Past reproduction negatively affected growth during summer and condition during autumn which, in turn, reduced the following year's reproductive output. These costs of previous reproduction were less pronounced under the high than under the low food treatment and lower in R. lessonae than in R. esculenta. Increasing food supply improved reproductive condition more in L than in E females. These species differences in reproductive costs and food requirements provide a mechanistic explanation for why E females skip annual reproduction almost twice as often as L females. Since R. esculenta is a sexual parasite that depends on R. lessonae for successful reproduction, these species-specific life history patterns not only affect individual fitness but also the spatial structure and temporal dynamics of mixed LE populations.
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A host infected with multiple parasitic species provides a unique system to test evolutionary and ecological hypotheses. Different parasitic species associated with a single host are expected to occupy different niches. This niche specialization can evolve from intraguild competition among parasites. However, niche specialization can also be structured directly by the host when its defence strategy depends on the parasite's potential impact. Then it can be expected that species with low or no tendency to prey on host brood will elicit less aggression than severe brood parasitic species and will be able to integrate better in the host system. We examined this hypothesis in a large community of symbionts associated with European red wood ants (Formica rufa group) by testing the association between 1) level of symbiont integration (i.e. presence in dense brood chambers vs. less populated chambers without brood) 2) level of ant aggression towards the symbiont 3) brood predation tendency of the symbiont.
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Food supply modifies the trade-off between past and future reproduction in a sexual parasite-host system (Rana esculenta, Rana lessonae).
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Life history theory is concerned with the costs of survival, growth and reproduction under different ecological conditions and the allocation of resources to meet these costs. Typical approaches used to address these topics include manipulation of food resources, followed by measures of subsequent reproductive traits, and measures of the relationship between current and future reproductive investment. Rarely, however, do studies test for the interaction of past investment, present resource availability and future investment simultaneously. Here, we investigate this interaction in females of a sexual parasite-host system consisting of the hybridogenetic frog Rana esculenta (E) and one of its parental species Rana lessonae (L). We kept females from each of two groups (with or without previous reproduction) under two food treatments (low or high) and regularly recorded their growth as well as their body condition and hormone titres as measures of future reproductive condition. After keeping them in hibernation until the following spring, we exposed the females to males, recorded whether they spawned or not and related this response to their condition in the previous autumn. Past reproduction negatively affected growth during summer and condition during autumn which, in turn, reduced the following year's reproductive output. These costs of previous reproduction were less pronounced under the high than under the low food treatment and lower in R. lessonae than in R. esculenta. Increasing food supply improved reproductive condition more in L than in E females. These species differences in reproductive costs and food requirements provide a mechanistic explanation for why E females skip annual reproduction almost twice as often as L females. Since R. esculenta is a sexual parasite that depends on R. lessonae for successful reproduction, these species-specific life history patterns not only affect individual fitness but also the spatial structure and temporal dynamics of mixed LE populations.
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Where multiple symbionts coexist in the same host, the selective elimination of a specific symbiont may enable the roles of a given symbiont to be investigated. We treated the Mediterranean species of the whitefly Bemisia tabaci complex by oral delivery of the antibiotic rifampicin, and then examined the temporal changes of its primary symbiont "Candidatus Portiera aleyrodidarum" and secondary symbiont "Ca. Hamiltonella defensa" as well as host fitness for three generations. In adults treated with rifampicin (F0), the secondary symbiont was rapidly reduced, approaching complete disappearance as adults aged. In contrast, the primary symbiont was little affected until later in the adult life. In the offspring of these adults (F1), both symbionts were significantly reduced and barely detectable when the hosts reached the adult stage. The F1 adults laid few eggs (F2), all of which failed to hatch. Mating experiments illustrated that the negative effects of rifampicin on host fitness were exerted via female hosts but not males. This study provides the first evidence of differential temporal reductions of primary and secondary symbionts in whiteflies following an antibiotic treatment. Studies that disrupt functions of bacterial symbionts must consider their temporal changes.
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Food supply modifies the trade-off between past and future reproduction in a sexual parasite-host system (Rana esculenta, Rana lessonae).
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Life history theory is concerned with the costs of survival, growth and reproduction under different ecological conditions and the allocation of resources to meet these costs. Typical approaches used to address these topics include manipulation of food resources, followed by measures of subsequent reproductive traits, and measures of the relationship between current and future reproductive investment. Rarely, however, do studies test for the interaction of past investment, present resource availability and future investment simultaneously. Here, we investigate this interaction in females of a sexual parasite-host system consisting of the hybridogenetic frog Rana esculenta (E) and one of its parental species Rana lessonae (L). We kept females from each of two groups (with or without previous reproduction) under two food treatments (low or high) and regularly recorded their growth as well as their body condition and hormone titres as measures of future reproductive condition. After keeping them in hibernation until the following spring, we exposed the females to males, recorded whether they spawned or not and related this response to their condition in the previous autumn. Past reproduction negatively affected growth during summer and condition during autumn which, in turn, reduced the following year's reproductive output. These costs of previous reproduction were less pronounced under the high than under the low food treatment and lower in R. lessonae than in R. esculenta. Increasing food supply improved reproductive condition more in L than in E females. These species differences in reproductive costs and food requirements provide a mechanistic explanation for why E females skip annual reproduction almost twice as often as L females. Since R. esculenta is a sexual parasite that depends on R. lessonae for successful reproduction, these species-specific life history patterns not only affect individual fitness but also the spatial structure and temporal dynamics of mixed LE populations.
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A large proportion of phytophagous insect species are specialised on one or a few host plants, and female host plant preference is predicted to be tightly linked to high larval survival and performance on the preferred plant(s). Specialisation is likely favoured by selection under stable circumstances, since different host plant species are likely to differ in suitability-a pattern usually explained by the "trade-off hypothesis", which posits that increased performance on a given plant comes at a cost of decreased performance on other plants. Host plant specialisation is also ascribed an important role in host shift speciation, where different incipient species specialise on different host plants. Hence, it is important to determine the role of host plants when studying species divergence and niche partitioning between closely related species, such as the butterfly species pair Leptidea sinapis and Leptidea reali. In Sweden, Leptidea sinapis is a habitat generalist, appearing in both forests and meadows, whereas Leptidea reali is specialised on meadows. Here, we study the female preference and larval survival and performance in terms of growth rate, pupal weight and development time on the seven most-utilised host plants. Both species showed similar host plant rank orders, and larvae survived and performed equally well on most plants with the exceptions of two rarely utilised forest plants. We therefore conclude that differences in preference or performance on plants from the two habitats do not drive, or maintain, niche separation, and we argue that the results of this study do not support the trade-off hypothesis for host plant specialisation, since the host plant generalist Leptidea sinapis survived and performed as well on the most preferred meadow host plant Lathyrus pratensis as did Leptidea reali although the generalist species also includes other plants in its host range.
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Synthetic auxotrophs for stable and tunable maintenance of plasmid copy number.
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Although plasmid-based expression systems have advantages in multi-copy expression of genes, heterogeneity of plasmid copy number (PCN) in individual cells is inevitable even with the addition of antibiotics. Here, we developed a synthetic auxotrophic system for stable and tunable maintenance of the PCN in Escherichia coli without addition of antibiotics. This auxotroph expresses infA, one of the essential genes encoding a translation initiation factor, on a plasmid instead of on the chromosome. With this system, the gene expression was stably maintained for 40 generations with minimized cell-to-cell variation under antibiotic-free conditions. Moreover, varying the expression level of infA enabled us to rationally tune the PCN by more than 5.6-fold. This antibiotic-free PCN control system significantly improved the production of itaconic acid and lycopene compared to the conventional system based on antibiotics (2-fold). Collectively, the developed strategy could be a platform for the production of value-added products in antibiotic-free cultivation.
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Plasmids are stably maintained extra-chromosomal genetic elements that replicate independently from the host cell's chromosomes. Although plasmids harbor biomedically important genes, (such as genes involved in virulence and antibiotics resistance), there is a shortage of specialized software tools for extracting and assembling plasmid data from whole genome sequencing projects.
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Synthetic auxotrophs for stable and tunable maintenance of plasmid copy number.
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Although plasmid-based expression systems have advantages in multi-copy expression of genes, heterogeneity of plasmid copy number (PCN) in individual cells is inevitable even with the addition of antibiotics. Here, we developed a synthetic auxotrophic system for stable and tunable maintenance of the PCN in Escherichia coli without addition of antibiotics. This auxotroph expresses infA, one of the essential genes encoding a translation initiation factor, on a plasmid instead of on the chromosome. With this system, the gene expression was stably maintained for 40 generations with minimized cell-to-cell variation under antibiotic-free conditions. Moreover, varying the expression level of infA enabled us to rationally tune the PCN by more than 5.6-fold. This antibiotic-free PCN control system significantly improved the production of itaconic acid and lycopene compared to the conventional system based on antibiotics (2-fold). Collectively, the developed strategy could be a platform for the production of value-added products in antibiotic-free cultivation.
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The complement of tRNA genes within a genome is typically considered to be a (relatively) stable characteristic of an organism. Here, we demonstrate that bacterial tRNA gene set composition can be more flexible than previously appreciated, particularly regarding tRNA gene copy number. We report the high-rate occurrence of spontaneous, large-scale, tandem duplication events in laboratory populations of the bacterium Pseudomonas fluorescens SBW25. The identified duplications are up to ∼1 Mb in size (∼15% of the wildtype genome) and are predicted to change the copy number of up to 917 genes, including several tRNA genes. The observed duplications are inherently unstable: they occur, and are subsequently lost, at extremely high rates. We propose that this unusually plastic type of mutation provides a mechanism by which tRNA gene set diversity can be rapidly generated, while simultaneously preserving the underlying tRNA gene set in the absence of continued selection. That is, if a tRNA set variant provides no fitness advantage, then high-rate segregation of the duplication ensures the maintenance of the original tRNA gene set. However, if a tRNA gene set variant is beneficial, the underlying duplication fragment(s) may persist for longer and provide raw material for further, more stable, evolutionary change.
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Synthetic auxotrophs for stable and tunable maintenance of plasmid copy number.
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Although plasmid-based expression systems have advantages in multi-copy expression of genes, heterogeneity of plasmid copy number (PCN) in individual cells is inevitable even with the addition of antibiotics. Here, we developed a synthetic auxotrophic system for stable and tunable maintenance of the PCN in Escherichia coli without addition of antibiotics. This auxotroph expresses infA, one of the essential genes encoding a translation initiation factor, on a plasmid instead of on the chromosome. With this system, the gene expression was stably maintained for 40 generations with minimized cell-to-cell variation under antibiotic-free conditions. Moreover, varying the expression level of infA enabled us to rationally tune the PCN by more than 5.6-fold. This antibiotic-free PCN control system significantly improved the production of itaconic acid and lycopene compared to the conventional system based on antibiotics (2-fold). Collectively, the developed strategy could be a platform for the production of value-added products in antibiotic-free cultivation.
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The broad host-range IncQ-2 family plasmid, pTF-FC2, is a mobilizable, medium copy number plasmid that lacks an active partitioning system. Plasmid stability is enhanced by a toxin-antitoxin (TA) system known as pas (plasmid addiction system) that is located within the replicon between the repB (primase) and the repA (helicase) and repC (DNA-binding) genes. The discovery of a closely related IncQ-2 plasmid, pRAS3, with a completely different TA system located between the repB and repAC genes raised the question of whether the location of pas within the replicon had an effect on the plasmid in addition to its ability to act as a TA system. In this work we demonstrate that the presence of the strongly expressed, autoregulated pas operon within the replicon resulted in an increase in the expression of the downstream repAC genes when autoregulation was relieved. While deletion of the pas module did not affect the average plasmid copy number, a pas-containing plasmid exhibited increased stability compared with a pas deletion plasmid even when the TA system was neutralized. It is proposed that the location of a strongly expressed, autoregulated operon within the replicon results in a rapid, but transient, expression of the repAC genes that enables the plasmid to rapidly restore its normal copy number should it fall below a threshold.
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Synthetic auxotrophs for stable and tunable maintenance of plasmid copy number.
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Although plasmid-based expression systems have advantages in multi-copy expression of genes, heterogeneity of plasmid copy number (PCN) in individual cells is inevitable even with the addition of antibiotics. Here, we developed a synthetic auxotrophic system for stable and tunable maintenance of the PCN in Escherichia coli without addition of antibiotics. This auxotroph expresses infA, one of the essential genes encoding a translation initiation factor, on a plasmid instead of on the chromosome. With this system, the gene expression was stably maintained for 40 generations with minimized cell-to-cell variation under antibiotic-free conditions. Moreover, varying the expression level of infA enabled us to rationally tune the PCN by more than 5.6-fold. This antibiotic-free PCN control system significantly improved the production of itaconic acid and lycopene compared to the conventional system based on antibiotics (2-fold). Collectively, the developed strategy could be a platform for the production of value-added products in antibiotic-free cultivation.
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Human centromeres are located within α-satellite arrays and evolve rapidly, which can lead to individual variation in array length. Proposed mechanisms for such alterations in length are unequal crossover between sister chromatids, gene conversion, and break-induced replication. However, the underlying molecular mechanisms responsible for the massive, complex, and homogeneous organization of centromeric arrays have not been experimentally validated. Here, we use droplet digital PCR assays to demonstrate that centromeric arrays can expand and contract within ∼20 somatic cell divisions of an alternative lengthening of telomere (ALT)-positive cell line. We find that the frequency of array variation among single-cell-derived subclones ranges from a minimum of ∼7% to a maximum of ∼100%. Further clonal evolution revealed that centromere expansion is favored over contraction. We find that the homologous recombination protein RAD52 and the helicase PIF1 are required for extensive array change, suggesting that centromere sequence evolution can occur via break-induced replication.
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Synthetic auxotrophs for stable and tunable maintenance of plasmid copy number.
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Although plasmid-based expression systems have advantages in multi-copy expression of genes, heterogeneity of plasmid copy number (PCN) in individual cells is inevitable even with the addition of antibiotics. Here, we developed a synthetic auxotrophic system for stable and tunable maintenance of the PCN in Escherichia coli without addition of antibiotics. This auxotroph expresses infA, one of the essential genes encoding a translation initiation factor, on a plasmid instead of on the chromosome. With this system, the gene expression was stably maintained for 40 generations with minimized cell-to-cell variation under antibiotic-free conditions. Moreover, varying the expression level of infA enabled us to rationally tune the PCN by more than 5.6-fold. This antibiotic-free PCN control system significantly improved the production of itaconic acid and lycopene compared to the conventional system based on antibiotics (2-fold). Collectively, the developed strategy could be a platform for the production of value-added products in antibiotic-free cultivation.
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Plasmids play an important role in bacterial evolution by transferring niche-adaptive functional genes between lineages, thus driving genomic diversification. Bacterial genomes commonly contain multiple, coexisting plasmid replicons, which could fuel adaptation by increasing the range of gene functions available to selection and allowing their recombination. However, plasmid coexistence is difficult to explain because the acquisition of plasmids typically incurs high fitness costs for the host cell. Here, we show that plasmid coexistence was stably maintained without positive selection for plasmid-borne gene functions and was associated with compensatory evolution to reduce fitness costs. In contrast, with positive selection, plasmid coexistence was unstable despite compensatory evolution. Positive selection discriminated between differential fitness benefits of functionally redundant plasmid replicons, retaining only the more beneficial plasmid. These data suggest that while the efficiency of negative selection against plasmid fitness costs declines over time due to compensatory evolution, positive selection to maximize plasmid-derived fitness benefits remains efficient. Our findings help to explain the forces structuring bacterial genomes: coexistence of multiple plasmids in a genome is likely to require either rare positive selection in nature or nonredundancy of accessory gene functions among the coexisting plasmids.<b>IMPORTANCE</b> Bacterial genomes often contain multiple coexisting plasmids that provide important functions like antibiotic resistance. Using lab experiments, we show that such plasmid coexistence within a genome is stable only in environments where the function they encode is useless but is unstable if the function is useful and beneficial for bacterial fitness. Where competing plasmids perform the same useful function, only the most beneficial plasmid is kept by the cell, a process that is similar to competitive exclusion in ecological communities. This process helps explain how bacterial genomes are structured: bacterial genomes expand in size by acquiring multiple plasmids when selection is relaxed but subsequently contract during periods of strong selection for the useful plasmid-encoded function.
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Acute renal failure and hepatocellular damage as presenting symptoms of type II aortic dissection.
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Pericardial effusion can be a consequence of a number of pathological conditions, and as
such it can cause impaired left ventricular filling followed by decreased cardiac output and blood pressure.
This kind of hemodynamic compromise and its consequences are extremely uncommon unless
pericardial effusion causes tamponade.
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Stanford type B aortic dissections (TBADs) involve the descending aorta and can present with complications, including malperfusion syndrome or aortic rupture, which are associated with significant morbidity and mortality if left untreated. Clinical diagnosis is straightforward, typically confirmed using CT angiography. Treatment begins with immediate anti-impulse medical therapy. Acute TBAD with complications should be repaired with emergent thoracic endovascular aortic repair (TEVAR). Uncomplicated TBAD with high-risk features should undergo TEVAR in the subacute phase. Open surgical repair is seldom required and reserved only for select cases. It is critical to follow these patients clinically and radiographically in the outpatient setting.
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Acute renal failure and hepatocellular damage as presenting symptoms of type II aortic dissection.
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Pericardial effusion can be a consequence of a number of pathological conditions, and as
such it can cause impaired left ventricular filling followed by decreased cardiac output and blood pressure.
This kind of hemodynamic compromise and its consequences are extremely uncommon unless
pericardial effusion causes tamponade.
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Acute aortic dissection can be fatal if overlooked, and the absence of D-dimer elevation can be used to exclude acute aortic dissection. However, we report a case of acute aortic dissection without D-dimer elevation. A man in his 70s presented to the emergency department with lumbar back pain. D-dimer was <1.0 µg/mL; however, acute aortic dissection was strongly suspected because of the sudden onset of lumbar back pain with a shifting location. Because of a difference in systolic blood pressure in both upper extremities, we performed a thorough examination using contrast-enhanced CT, leading to a diagnosis of acute aortic dissection. The patient was immediately referred to cardiovascular surgery and treated conservatively with antihypertensive management. The aortic dissection detection risk score (ADD-RS) classified the patient as high risk. This suggests the importance of using the D-dimer with the ADD-RS rather than solely relying on the D-dimer results to diagnose acute aortic dissection.
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Acute renal failure and hepatocellular damage as presenting symptoms of type II aortic dissection.
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Pericardial effusion can be a consequence of a number of pathological conditions, and as
such it can cause impaired left ventricular filling followed by decreased cardiac output and blood pressure.
This kind of hemodynamic compromise and its consequences are extremely uncommon unless
pericardial effusion causes tamponade.
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Acute kidney injury (AKI) is a common complication in advanced liver dysfunction. Our aim is to clarify the mechanisms of acute hepatic failure (AHF)-associated AKI.
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Acute renal failure and hepatocellular damage as presenting symptoms of type II aortic dissection.
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Pericardial effusion can be a consequence of a number of pathological conditions, and as
such it can cause impaired left ventricular filling followed by decreased cardiac output and blood pressure.
This kind of hemodynamic compromise and its consequences are extremely uncommon unless
pericardial effusion causes tamponade.
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Acute aortic dissection (AAD) is a rare and lethal disease with presenting signs and symptoms that can often be seen with other high risk conditions; diagnosis is therefore often delayed or missed. Pain is present in up to 90% of cases and is typically severe at onset. Many patients present with acute on chronic hypertension, but hypotension is an ominous sign, often reflecting hemorrhage or cardiac tamponade. The chest x-ray can be normal in 10-20% of patients with AAD, and though transthoracic echocardiography is useful if suggestive findings are seen, and should be used to identify pericardial effusion, TTE cannot be used to exclude AAD. Transesophageal echocardiography, however, reliably confirms or excludes the diagnosis, where such equipment and expertise is available. CT scan with IV contrast is the most common imaging modality used to diagnose and classify AAD, and MRI can be used in patients in whom the use of CT or IV contrast is undesirable. Recent specialty guidelines have helped define high-risk features and a diagnostic pathway that can be used the emergency department setting. Initial management of diagnosed or highly suspected acute aortic dissection focuses on pain control, heart rate and then blood pressure management, and immediate surgical consultation.
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Acute renal failure and hepatocellular damage as presenting symptoms of type II aortic dissection.
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Pericardial effusion can be a consequence of a number of pathological conditions, and as
such it can cause impaired left ventricular filling followed by decreased cardiac output and blood pressure.
This kind of hemodynamic compromise and its consequences are extremely uncommon unless
pericardial effusion causes tamponade.
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Described below is a case of a 72-year-old man with an abdominal aortic aneurysm (AAA) presenting with symptoms of renal colic. This case illustrates the hazards of making a diagnosis of renal colic in an elderly patient without considering the diagnosis of a leaking AAA. The diagnosis of an AAA can be challenging and renal colic is the single most common misdiagnosis. The patient's initial presentation can be misleading as symptoms fit the features of renal colic or a leaking AAA. Despite normal haemoglobin, microscopic haematuria and a dilated ureter on intravenous urogram (IVU); a leaking AAA should still have been considered. An ultrasound or CT (rather than an IVU) scan would have confirmed the appropriate diagnosis. A high degree of suspicion, early identification and surgical intervention can help reduce the high incidence of mortality in such cases.
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Understanding geriatric models of care for older adults living with HIV: a scoping review and qualitative analysis.
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Advances in Human Immunodeficiency Virus (HIV) treatment have reduced mortality rates and consequently increased the number of individuals with HIV living into older age. Despite this, people aged 50 years and older have been left behind in recent HIV treatment and prevention campaigns, and a gold-standard model of care for this population has not yet been defined. Developing evidence-based geriatric HIV models of care can support an accessible, equitable, and sustainable HIV health care system that ensures older adults have access to care that meets their needs now and in the future.
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Many people ageing with HIV are also living with multiple comorbidities and geriatric syndromes including frailty and cognitive deterioration. These complex needs can be challenging to meet within existing HIV care services. This study investigates the acceptability and feasibility of screening for frailty and of using a comprehensive geriatric assessment approach, delivered via the Silver Clinic, to support people living with HIV affected by frailty.
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Understanding geriatric models of care for older adults living with HIV: a scoping review and qualitative analysis.
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Advances in Human Immunodeficiency Virus (HIV) treatment have reduced mortality rates and consequently increased the number of individuals with HIV living into older age. Despite this, people aged 50 years and older have been left behind in recent HIV treatment and prevention campaigns, and a gold-standard model of care for this population has not yet been defined. Developing evidence-based geriatric HIV models of care can support an accessible, equitable, and sustainable HIV health care system that ensures older adults have access to care that meets their needs now and in the future.
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The aim of this scoping review is to map the nurse-led care management models for patients with multimorbidity in hospital settings.
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Understanding geriatric models of care for older adults living with HIV: a scoping review and qualitative analysis.
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Advances in Human Immunodeficiency Virus (HIV) treatment have reduced mortality rates and consequently increased the number of individuals with HIV living into older age. Despite this, people aged 50 years and older have been left behind in recent HIV treatment and prevention campaigns, and a gold-standard model of care for this population has not yet been defined. Developing evidence-based geriatric HIV models of care can support an accessible, equitable, and sustainable HIV health care system that ensures older adults have access to care that meets their needs now and in the future.
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The provision of inclusive health services for older adults requires a holistic approach to the health needs of the ageing population and their social environment, to deliver an effective response. To describe the health needs of older adults and their social environment, as a basis for integration of primary health care services. A non-systematic narrative review of the literature was conducted based on an electronic database covering the period 2019-2023 along with a combination of citation references. Information collection followed the principles of the thematic analysis derived from the qualitative approach. Two groups of health needs for older adults were identified: natural aging processes and disease processes. The social environment for these health needs were conceptualized in three interconnected dimensions: socioeconomic conditions, health services, and place of residence. Understanding the elements underlying the health needs which are determined by contextual conditions, supports strategies to improve services for older adults as part of the primary health care approach.
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Understanding geriatric models of care for older adults living with HIV: a scoping review and qualitative analysis.
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Advances in Human Immunodeficiency Virus (HIV) treatment have reduced mortality rates and consequently increased the number of individuals with HIV living into older age. Despite this, people aged 50 years and older have been left behind in recent HIV treatment and prevention campaigns, and a gold-standard model of care for this population has not yet been defined. Developing evidence-based geriatric HIV models of care can support an accessible, equitable, and sustainable HIV health care system that ensures older adults have access to care that meets their needs now and in the future.
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The aim of this scoping review was to examine available evidence regarding use of technology-based continence care delivery for older adults and to identify gaps in knowledge.
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Understanding geriatric models of care for older adults living with HIV: a scoping review and qualitative analysis.
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Advances in Human Immunodeficiency Virus (HIV) treatment have reduced mortality rates and consequently increased the number of individuals with HIV living into older age. Despite this, people aged 50 years and older have been left behind in recent HIV treatment and prevention campaigns, and a gold-standard model of care for this population has not yet been defined. Developing evidence-based geriatric HIV models of care can support an accessible, equitable, and sustainable HIV health care system that ensures older adults have access to care that meets their needs now and in the future.
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The purpose of this scoping review was to explore peer-reviewed research and gray literature to examine the extent, range, and nature of available research that describes how home care case managers (HCCMs) provide integrated care for older adults with multiple chronic conditions (MCCs); identify how case management standards of practice correspond with functions of integrated care; identify facilitators and barriers to case management and integrated care delivery; and propose a framework to describe how HCCMs can use case management standards to provide integrated care to older adults with MCCs.
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2, 4, 5-Trideoxyhexopyranosides Derivatives of 4'-Demethylepipodophyllotoxin: <i>De novo</i> Synthesis and Anticancer Activity.
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Podophyllotoxin is a natural lignan which possesses anticancer and antiviral activities. Etoposide and teniposide are semisynthetic glycoside derivatives of podophyllotoxin and are increasingly used in cancer medicine.
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A convenient method has been developed for the glycol-conjugation in 3-position of β-anhydroicaritine in a reasonable yield. The structure of the 3-glycosylated β-anhydroicaritine derivatives was confirmed to be correct by <sup>1</sup>H NMR, <sup>13</sup>C NMR and HRMS spectrum. These compounds are less soluble than icaritin, but more soluble than icariside II in CCl<sub>4</sub>. The screening results showed that compounds <b>12h</b>, <b>12i</b> and <b>12j</b> had higher cytotoxicity to HepG2 and MCF-7 at a concentration of 50 μM.
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2, 4, 5-Trideoxyhexopyranosides Derivatives of 4'-Demethylepipodophyllotoxin: <i>De novo</i> Synthesis and Anticancer Activity.
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Podophyllotoxin is a natural lignan which possesses anticancer and antiviral activities. Etoposide and teniposide are semisynthetic glycoside derivatives of podophyllotoxin and are increasingly used in cancer medicine.
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Two new 12- or 13- membered-ring macrocyclic alkaloids ascomylactam D and E (1 & 2), and a pair of new enantiomer (+)- and (-)- didymetone (3) were purified from the mangrove endophytic fungus Didymella sp. CYSK-4. Their structures and absolute configurations were determined by extensive spectroscopic analysis, single-crystal X-ray diffraction, ECD and <sup>13</sup>C NMR calculations. Compound 2 exhibited significant cytotoxicity against human A549 and KYSE 150 cancer cell lines with IC<sub>50</sub> values of 2.8 μM and 5.9 μM, respectively.
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2, 4, 5-Trideoxyhexopyranosides Derivatives of 4'-Demethylepipodophyllotoxin: <i>De novo</i> Synthesis and Anticancer Activity.
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Podophyllotoxin is a natural lignan which possesses anticancer and antiviral activities. Etoposide and teniposide are semisynthetic glycoside derivatives of podophyllotoxin and are increasingly used in cancer medicine.
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Cardiac glycosides exhibit significant anticancer effects and the glycosyl substitution at C<sub>3</sub> position of digoxigenin is pivotal for their biological activity. In order to study the structure-activity relationship (SAR) of cardiac glycosides toward cancers and explore more potent anticancer agents, a series of C<sub>3</sub>-O-neoglycosides and C<sub>3</sub>-MeON-neoglycosides of digoxigenin were synthesized by the Koenigs-Knorr and neoglycosylation method, respectively. In addition, digoxigenin bisdigitoxoside and monodigitoxoside were prepared from digoxin by sodium periodate (NaIO<sub>4</sub>) oxidation and 6-aminocaproic acid hydrolysis. The SAR analysis revealed that C<sub>3</sub>-O-neoglycosides of digoxigenin exhibited stronger cytotoxicity and induction of Nur77 expression of tumor cells than C<sub>3</sub>-MeON-neoglycosides. Also, 3β-O-glycosides exhibited stronger anticancer effects than 3α-O-glycosides. Among them, 3β-O-(β-l-fucopyranosyl)-digoxigenin (3i) showed the highest activity on induction of Nur77 expression and translocation from the nucleus to cytoplasm, leading to cancer cell apoptosis.
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2, 4, 5-Trideoxyhexopyranosides Derivatives of 4'-Demethylepipodophyllotoxin: <i>De novo</i> Synthesis and Anticancer Activity.
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Podophyllotoxin is a natural lignan which possesses anticancer and antiviral activities. Etoposide and teniposide are semisynthetic glycoside derivatives of podophyllotoxin and are increasingly used in cancer medicine.
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The known DNMT inhibitor SGI-1027 4 has been synthesized using as key steps Pd-catalyzed Ar-N bond formation reactions performed in a sequential or convergent manner. In the former approach, a by-product, which corresponds to the incorporation of two units of 4-chloroquinoline, was also isolated. The biological effects of compound 4 in the U937 human leukemia cell line are also described.
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2, 4, 5-Trideoxyhexopyranosides Derivatives of 4'-Demethylepipodophyllotoxin: <i>De novo</i> Synthesis and Anticancer Activity.
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Podophyllotoxin is a natural lignan which possesses anticancer and antiviral activities. Etoposide and teniposide are semisynthetic glycoside derivatives of podophyllotoxin and are increasingly used in cancer medicine.
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A series of amino derivatives of 10-(diphenylmethylene)-4-azatricyclo[5.2.1.0(2.6)]dec-8-ene-3,5-dione, analogues of chlorpromazine and aminoperazine have been prepared. These compounds are expected to have antipsychotic and/or anti HIV activity. Molecular structure of III was confirmed by an X-ray structure analysis. The cytotoxicity and anti HIV activity of derivatives I-IV were determined.
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Improving the Quality of EDTA-treated Blood Specimens from Mice.
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Nonterminal blood sampling in laboratory mice is a very common procedure. With the goal of improving animal welfare, different sampling sites and methods have been compared but have not achieved a consensus. Moreover, most of these studies overlooked the quality of blood specimens collected. The main preanalytical concern with EDTA-treated blood specimens for hematology analyses is platelet aggregation, which is known to cause analytical errors. Our objective was to find a nonterminal blood sampling method with minimal adverse effects on mice and few or no platelet aggregates. We tested and compared 2 collection sites, 4 sampling methods, and 3 antithrombotic drugs in 80 C57BL6/j male and female mice by evaluating platelet aggregates on blood smears and platelet, WBC, and RBC counts. In addition, the blood collection process was carefully evaluated, and adverse effects were recorded. Platelet aggregation was lower in specimens collected from the jugular vein than from the facial vein, with no effect of the sampling device or the presence of an antithrombotic additive. Highly aggregated specimens were significantly associated with lower platelet counts, whereas aggregation had no effect on WBC or RBC counts. Adverse events during sampling were significantly associated with more numerous platelet aggregates. The jugular vein is thus a satisfactory sampling site in mice in terms of both animal welfare and low platelet aggregation. Using antithrombotic agents appears to be unnecessary, whereas improving sampling conditions remains a key requirement to ensure the quality of EDTA-treated blood specimens from mice.
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Automated component collection systems offer the possibility of increasing blood supply and improving transfusion safety.
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Improving the Quality of EDTA-treated Blood Specimens from Mice.
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Nonterminal blood sampling in laboratory mice is a very common procedure. With the goal of improving animal welfare, different sampling sites and methods have been compared but have not achieved a consensus. Moreover, most of these studies overlooked the quality of blood specimens collected. The main preanalytical concern with EDTA-treated blood specimens for hematology analyses is platelet aggregation, which is known to cause analytical errors. Our objective was to find a nonterminal blood sampling method with minimal adverse effects on mice and few or no platelet aggregates. We tested and compared 2 collection sites, 4 sampling methods, and 3 antithrombotic drugs in 80 C57BL6/j male and female mice by evaluating platelet aggregates on blood smears and platelet, WBC, and RBC counts. In addition, the blood collection process was carefully evaluated, and adverse effects were recorded. Platelet aggregation was lower in specimens collected from the jugular vein than from the facial vein, with no effect of the sampling device or the presence of an antithrombotic additive. Highly aggregated specimens were significantly associated with lower platelet counts, whereas aggregation had no effect on WBC or RBC counts. Adverse events during sampling were significantly associated with more numerous platelet aggregates. The jugular vein is thus a satisfactory sampling site in mice in terms of both animal welfare and low platelet aggregation. Using antithrombotic agents appears to be unnecessary, whereas improving sampling conditions remains a key requirement to ensure the quality of EDTA-treated blood specimens from mice.
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Automated blood collection platforms use different technological systems to isolate and collect individual blood components. These unique systems could potentially result in differences in platelet in vivo viability, as measured by the corrected count increment (CCI).
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Improving the Quality of EDTA-treated Blood Specimens from Mice.
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Nonterminal blood sampling in laboratory mice is a very common procedure. With the goal of improving animal welfare, different sampling sites and methods have been compared but have not achieved a consensus. Moreover, most of these studies overlooked the quality of blood specimens collected. The main preanalytical concern with EDTA-treated blood specimens for hematology analyses is platelet aggregation, which is known to cause analytical errors. Our objective was to find a nonterminal blood sampling method with minimal adverse effects on mice and few or no platelet aggregates. We tested and compared 2 collection sites, 4 sampling methods, and 3 antithrombotic drugs in 80 C57BL6/j male and female mice by evaluating platelet aggregates on blood smears and platelet, WBC, and RBC counts. In addition, the blood collection process was carefully evaluated, and adverse effects were recorded. Platelet aggregation was lower in specimens collected from the jugular vein than from the facial vein, with no effect of the sampling device or the presence of an antithrombotic additive. Highly aggregated specimens were significantly associated with lower platelet counts, whereas aggregation had no effect on WBC or RBC counts. Adverse events during sampling were significantly associated with more numerous platelet aggregates. The jugular vein is thus a satisfactory sampling site in mice in terms of both animal welfare and low platelet aggregation. Using antithrombotic agents appears to be unnecessary, whereas improving sampling conditions remains a key requirement to ensure the quality of EDTA-treated blood specimens from mice.
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The 'order of draw' has been advocated since 1982 to reduce the risk of cross-contaminating blood tubes with additives from a previously filled tube.
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Improving the Quality of EDTA-treated Blood Specimens from Mice.
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Nonterminal blood sampling in laboratory mice is a very common procedure. With the goal of improving animal welfare, different sampling sites and methods have been compared but have not achieved a consensus. Moreover, most of these studies overlooked the quality of blood specimens collected. The main preanalytical concern with EDTA-treated blood specimens for hematology analyses is platelet aggregation, which is known to cause analytical errors. Our objective was to find a nonterminal blood sampling method with minimal adverse effects on mice and few or no platelet aggregates. We tested and compared 2 collection sites, 4 sampling methods, and 3 antithrombotic drugs in 80 C57BL6/j male and female mice by evaluating platelet aggregates on blood smears and platelet, WBC, and RBC counts. In addition, the blood collection process was carefully evaluated, and adverse effects were recorded. Platelet aggregation was lower in specimens collected from the jugular vein than from the facial vein, with no effect of the sampling device or the presence of an antithrombotic additive. Highly aggregated specimens were significantly associated with lower platelet counts, whereas aggregation had no effect on WBC or RBC counts. Adverse events during sampling were significantly associated with more numerous platelet aggregates. The jugular vein is thus a satisfactory sampling site in mice in terms of both animal welfare and low platelet aggregation. Using antithrombotic agents appears to be unnecessary, whereas improving sampling conditions remains a key requirement to ensure the quality of EDTA-treated blood specimens from mice.
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To investigate the influence of handling and storage on HE4 and CA125 serum and EDTA plasma levels to clarify any important consequences for a clinical setting.
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Improving the Quality of EDTA-treated Blood Specimens from Mice.
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Nonterminal blood sampling in laboratory mice is a very common procedure. With the goal of improving animal welfare, different sampling sites and methods have been compared but have not achieved a consensus. Moreover, most of these studies overlooked the quality of blood specimens collected. The main preanalytical concern with EDTA-treated blood specimens for hematology analyses is platelet aggregation, which is known to cause analytical errors. Our objective was to find a nonterminal blood sampling method with minimal adverse effects on mice and few or no platelet aggregates. We tested and compared 2 collection sites, 4 sampling methods, and 3 antithrombotic drugs in 80 C57BL6/j male and female mice by evaluating platelet aggregates on blood smears and platelet, WBC, and RBC counts. In addition, the blood collection process was carefully evaluated, and adverse effects were recorded. Platelet aggregation was lower in specimens collected from the jugular vein than from the facial vein, with no effect of the sampling device or the presence of an antithrombotic additive. Highly aggregated specimens were significantly associated with lower platelet counts, whereas aggregation had no effect on WBC or RBC counts. Adverse events during sampling were significantly associated with more numerous platelet aggregates. The jugular vein is thus a satisfactory sampling site in mice in terms of both animal welfare and low platelet aggregation. Using antithrombotic agents appears to be unnecessary, whereas improving sampling conditions remains a key requirement to ensure the quality of EDTA-treated blood specimens from mice.
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The type of blood collection tube affects specimen quality and laboratory results. Because plasma specimens have a shorter processing time compared with serum specimens, emergency biochemistry tests use plasma. However, serum specimens remain stable after centrifugation and show more accurate results than plasma. Therefore, a quick-clotting serum separator tube is expected to be useful for shorter turnaround times and accurate results. We evaluated a new quick-clotting serum separator tube VQ-Tube™ (AB Medical, Korea) for clinical chemistry and thyroid hormone assays.
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Double wall versus single wall incubator for reducing heat loss in very low birth weight infants in incubators.
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Studies have shown improved survival of newborn infants maintained in the thermoneutral range. The concept of an incubator with additional insulation, a double plexiglass wall, is appealing for very low birth weight infants as it may help to provide a thermoneutral environment.
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The outcome of extremely low birth weight (ELBW, ≤1000 g) infants has recently been improved in Taiwan. However, their postdischarge anthropometry and development have seldom been explored. We report these results for ELBW infants at corrected age of 2 years in a tertiary care center.
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Double wall versus single wall incubator for reducing heat loss in very low birth weight infants in incubators.
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Studies have shown improved survival of newborn infants maintained in the thermoneutral range. The concept of an incubator with additional insulation, a double plexiglass wall, is appealing for very low birth weight infants as it may help to provide a thermoneutral environment.
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We compared effects of infant positioning and feed-rate interventions on respiratory events and oximetry parameters in spontaneously breathing preterm infants born <32 weeks gestation managed in a neonatal unit.
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Double wall versus single wall incubator for reducing heat loss in very low birth weight infants in incubators.
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Studies have shown improved survival of newborn infants maintained in the thermoneutral range. The concept of an incubator with additional insulation, a double plexiglass wall, is appealing for very low birth weight infants as it may help to provide a thermoneutral environment.
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Infants born at less than 34 weeks' gestational age are at higher risk for morbidity and mortality. Data are limited on the impact of maternal obesity on the very preterm infant. This study reviewed whether maternal obesity further increases the intensive care needs of very preterm infants of less than 34 weeks' gestation.
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Double wall versus single wall incubator for reducing heat loss in very low birth weight infants in incubators.
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Studies have shown improved survival of newborn infants maintained in the thermoneutral range. The concept of an incubator with additional insulation, a double plexiglass wall, is appealing for very low birth weight infants as it may help to provide a thermoneutral environment.
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To explore the effect of feeding initiation with different formulas on the growth, development, and feeding tolerance in very low birth weight infants.
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Double wall versus single wall incubator for reducing heat loss in very low birth weight infants in incubators.
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Studies have shown improved survival of newborn infants maintained in the thermoneutral range. The concept of an incubator with additional insulation, a double plexiglass wall, is appealing for very low birth weight infants as it may help to provide a thermoneutral environment.
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We determined thromboelastographic (TEG) profiles of healthy very low birthweight infants (VLBWIs) of the day of birth and at set intervals during their first month.
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Combination vaccines: synergistic simultaneous induction of antibody and T-cell immunity.
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Vaccines have traditionally been designed to induce antibody responses and have been licensed on their capacity to induce high titers of circulating antibody to the pathogen. With our increased knowledge of host-pathogen interactions, it became apparent that induction of the cellular arm of the immune response is crucial to the efficacy of vaccines against intracellular pathogens and for providing appropriate help for antibody induction. Diverging strategies emerged that concentrate on developing candidate vaccines that solely induce either cellular or humoral responses. As most microbes reside at some point in the infectious cycle in the extracellular as well as intracellular space, and there is interplay between antibody and T cells, it is now apparent that both arms of immunity are essential to effectively control and eliminate the infection. It is, therefore, necessary to develop vaccines that can effectively induce a broad adaptive immune response. For vaccines targeted at diseases of the developing world, such as HIV, tuberculosis and malaria, it is imperative that these vaccines are simple to deliver and cost effective, that is,that optimum T-cell and antibody immunity is achieved with the minimum number of vaccinations. Combination vaccines, where an antibody-inducing subunit protein vaccine is coadministered with a T-cell-inducing poxvirus-based vaccine fulfill these requirements and induce sterile immunity to pathogen challenge.
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Patients receiving anti-CD20 antibodies showed limited efficacy of a booster dose of BNT162b2. Patients with lymphomas combine such immunotherapies with cytotoxic chemotherapies that could result in an even greater alteration of the immune response to vaccination. We report here the impact of a third vaccine dose on T cell specific responses in a small cohort of patients treated in our center by anti-CD20 therapies and cytotoxic chemotherapies for lymphoid malignancies. Our results showed that a third dose in these severely immune suppressed patients could improve the expansion on CD4<sup>+</sup>Th1<sup>+</sup>T cell responses while the effect CD8 + T cell responses was marginal.
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Combination vaccines: synergistic simultaneous induction of antibody and T-cell immunity.
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Vaccines have traditionally been designed to induce antibody responses and have been licensed on their capacity to induce high titers of circulating antibody to the pathogen. With our increased knowledge of host-pathogen interactions, it became apparent that induction of the cellular arm of the immune response is crucial to the efficacy of vaccines against intracellular pathogens and for providing appropriate help for antibody induction. Diverging strategies emerged that concentrate on developing candidate vaccines that solely induce either cellular or humoral responses. As most microbes reside at some point in the infectious cycle in the extracellular as well as intracellular space, and there is interplay between antibody and T cells, it is now apparent that both arms of immunity are essential to effectively control and eliminate the infection. It is, therefore, necessary to develop vaccines that can effectively induce a broad adaptive immune response. For vaccines targeted at diseases of the developing world, such as HIV, tuberculosis and malaria, it is imperative that these vaccines are simple to deliver and cost effective, that is,that optimum T-cell and antibody immunity is achieved with the minimum number of vaccinations. Combination vaccines, where an antibody-inducing subunit protein vaccine is coadministered with a T-cell-inducing poxvirus-based vaccine fulfill these requirements and induce sterile immunity to pathogen challenge.
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Live-attenuated vaccines (LAVs) have achieved remarkable successes in controlling virus spread, as well as for other applications such as cancer immunotherapy. However, with rapid increases in international travel, globalization, geographic spread of viral vectors, and widespread use of vaccines, there is an increasing need to consider how pre-exposure to viruses which share similar antigenic regions can impact vaccine efficacy. Pre-existing antibodies, derived from either from maternal-fetal transmission, or by previous infection or vaccination, have been demonstrated to interfere with vaccine immunogenicity of measles, adenovirus, and influenza LAVs. Immune interference of LAVs can be caused by the formation of virus-antibody complexes that neutralize virus infection in antigen-presenting cells, or by the cross-linking of the B-cell receptor with the inhibitory receptor, FcgRIIB. On the other hand, pre-existing antibodies can augment flaviviral LAV efficacy such as that of dengue and yellow fever virus, especially when pre-existing antibodies are present at sub-neutralizing levels. The increased vaccine immunogenicity can be facilitated by antibody-dependent enhancement of virus infection, enhancing virus uptake in antigen-presenting cells, and robust induction of innate immune responses that promote vaccine immunogenicity. This review examines the literature on this topic and examines the circumstances where pre-existing antibodies can inhibit or enhance LAV efficacy. A better knowledge of the underlying mechanisms involved could allow us to better manage immunization in seropositive individuals and even identify possibilities that could allow us to exploit pre-existing antibodies to boost vaccine-induced responses for improved vaccine efficacy.
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Combination vaccines: synergistic simultaneous induction of antibody and T-cell immunity.
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Vaccines have traditionally been designed to induce antibody responses and have been licensed on their capacity to induce high titers of circulating antibody to the pathogen. With our increased knowledge of host-pathogen interactions, it became apparent that induction of the cellular arm of the immune response is crucial to the efficacy of vaccines against intracellular pathogens and for providing appropriate help for antibody induction. Diverging strategies emerged that concentrate on developing candidate vaccines that solely induce either cellular or humoral responses. As most microbes reside at some point in the infectious cycle in the extracellular as well as intracellular space, and there is interplay between antibody and T cells, it is now apparent that both arms of immunity are essential to effectively control and eliminate the infection. It is, therefore, necessary to develop vaccines that can effectively induce a broad adaptive immune response. For vaccines targeted at diseases of the developing world, such as HIV, tuberculosis and malaria, it is imperative that these vaccines are simple to deliver and cost effective, that is,that optimum T-cell and antibody immunity is achieved with the minimum number of vaccinations. Combination vaccines, where an antibody-inducing subunit protein vaccine is coadministered with a T-cell-inducing poxvirus-based vaccine fulfill these requirements and induce sterile immunity to pathogen challenge.
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Emerging data in animal models and humans suggest that pathogen-associated and damage-associated molecular patterns variably impact RBC alloantibody formation. In this study, we tested the hypothesis that vaccinations may enhance immune responses to transfused RBCs. The Pneumovax23 vaccine decreased the magnitude of anti-KEL alloimmunization in a murine model, whereas the hepB vaccine did not impact the response; RBC transfusion did not alter immune responses to either vaccine. These data highlight the complexities of the intersection of innate and adaptive immunity and suggest that future studies investigating the pathways through which inflammation impacts alloimmunization are warranted.
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Combination vaccines: synergistic simultaneous induction of antibody and T-cell immunity.
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Vaccines have traditionally been designed to induce antibody responses and have been licensed on their capacity to induce high titers of circulating antibody to the pathogen. With our increased knowledge of host-pathogen interactions, it became apparent that induction of the cellular arm of the immune response is crucial to the efficacy of vaccines against intracellular pathogens and for providing appropriate help for antibody induction. Diverging strategies emerged that concentrate on developing candidate vaccines that solely induce either cellular or humoral responses. As most microbes reside at some point in the infectious cycle in the extracellular as well as intracellular space, and there is interplay between antibody and T cells, it is now apparent that both arms of immunity are essential to effectively control and eliminate the infection. It is, therefore, necessary to develop vaccines that can effectively induce a broad adaptive immune response. For vaccines targeted at diseases of the developing world, such as HIV, tuberculosis and malaria, it is imperative that these vaccines are simple to deliver and cost effective, that is,that optimum T-cell and antibody immunity is achieved with the minimum number of vaccinations. Combination vaccines, where an antibody-inducing subunit protein vaccine is coadministered with a T-cell-inducing poxvirus-based vaccine fulfill these requirements and induce sterile immunity to pathogen challenge.
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Trained immunity-based vaccines (TIbV) is an emerging vaccine strategy in the field of vaccine research, referring to vaccines designed based on the principles of trained immunity (TI). TI involves the enhanced immune response of innate immune cells upon re-stimulation after being trained. TIbV, built on the concept of TI, aims to enhance resistance to various infectious pathogens by training the host's innate immune system to acquire natural immune memory. This approach is designed to bolster immunity against a wide range of infectious agents, including those not covered by conventional vaccines. This article reviews the concepts, mechanisms, application areas, and future prospects of TIbV, intending to offer a new perspective for vaccine development and design.
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Combination vaccines: synergistic simultaneous induction of antibody and T-cell immunity.
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Vaccines have traditionally been designed to induce antibody responses and have been licensed on their capacity to induce high titers of circulating antibody to the pathogen. With our increased knowledge of host-pathogen interactions, it became apparent that induction of the cellular arm of the immune response is crucial to the efficacy of vaccines against intracellular pathogens and for providing appropriate help for antibody induction. Diverging strategies emerged that concentrate on developing candidate vaccines that solely induce either cellular or humoral responses. As most microbes reside at some point in the infectious cycle in the extracellular as well as intracellular space, and there is interplay between antibody and T cells, it is now apparent that both arms of immunity are essential to effectively control and eliminate the infection. It is, therefore, necessary to develop vaccines that can effectively induce a broad adaptive immune response. For vaccines targeted at diseases of the developing world, such as HIV, tuberculosis and malaria, it is imperative that these vaccines are simple to deliver and cost effective, that is,that optimum T-cell and antibody immunity is achieved with the minimum number of vaccinations. Combination vaccines, where an antibody-inducing subunit protein vaccine is coadministered with a T-cell-inducing poxvirus-based vaccine fulfill these requirements and induce sterile immunity to pathogen challenge.
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Antibodies against the protective antigen (PA) component of anthrax toxin play an important role in protection against disease caused by Bacillus anthracis. In this study, we examined defined combinations of PA-specific monoclonal antibodies for their ability to neutralize anthrax toxin in cell culture assays. We observed additive, synergistic, and antagonistic effects of the antibodies depending on the specific antibody combination examined and the specific assay used. Synergistic toxin-neutralizing antibody interactions were examined in more detail. We found that one mechanism that can lead to antibody synergy is the bridging of PA monomers by one antibody, with resultant bivalent binding of the second antibody. These results may aid in optimal design of new vaccines and antibody therapies against anthrax.
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How noise statistics impact models of enzyme cycles.
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Theoretical tools for adequately treating stochastic effects are important for understanding their role in biological processes. Although master equations provide rigorous means for investigating effects associated with fluctuations of discrete molecular copy numbers, they can be very challenging to treat analytically and numerically. Approaches based on the Langevin approximation are often more tractable, but care must be used to ensure that it is justified in each situation. Here, we examine a model of an enzyme cycle for which noise qualitatively alters the behavior of the system: fluctuations in the population of an enzyme can result in amplification and multistability in the distribution of its product. We compare master equation and Langevin treatments of this system and show that results derived previously with a white noise Langevin equation [M. Samoilov et al., Proc. Natl. Acad. Sci. U.S.A. 102, 2310 (2005)] are inconsistent with the master equation. A colored noise Langevin equation captures some, but not all, of the essential physics of the system. The advantages and disadvantages of the Langevin approximation for modeling biological processes are discussed.
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In the noisy cellular environment, stochastic fluctuations at the molecular level manifest as cell-cell variability at the population level that is quantifiable using high-throughput single-cell measurements. Such variability is rich with information about the cell's underlying gene regulatory networks, their architecture and the parameters of the biochemical reactions at their core.
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How noise statistics impact models of enzyme cycles.
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Theoretical tools for adequately treating stochastic effects are important for understanding their role in biological processes. Although master equations provide rigorous means for investigating effects associated with fluctuations of discrete molecular copy numbers, they can be very challenging to treat analytically and numerically. Approaches based on the Langevin approximation are often more tractable, but care must be used to ensure that it is justified in each situation. Here, we examine a model of an enzyme cycle for which noise qualitatively alters the behavior of the system: fluctuations in the population of an enzyme can result in amplification and multistability in the distribution of its product. We compare master equation and Langevin treatments of this system and show that results derived previously with a white noise Langevin equation [M. Samoilov et al., Proc. Natl. Acad. Sci. U.S.A. 102, 2310 (2005)] are inconsistent with the master equation. A colored noise Langevin equation captures some, but not all, of the essential physics of the system. The advantages and disadvantages of the Langevin approximation for modeling biological processes are discussed.
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The movement of single kinesin molecules was observed while applying noisy external forces that mimic intracellular active fluctuations. We found kinesin accelerates under noise, especially when a large hindering load is added. The behavior quantitatively conformed to a theoretical model that describes the kinesin movement with simple two-state reactions. The universality of the kinetic theory suggests that intracellular enzymes share a similar noise-induced acceleration mechanism, i.e., active fluctuations in cells are not just noise but are utilized to promote various physiological processes.
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How noise statistics impact models of enzyme cycles.
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Theoretical tools for adequately treating stochastic effects are important for understanding their role in biological processes. Although master equations provide rigorous means for investigating effects associated with fluctuations of discrete molecular copy numbers, they can be very challenging to treat analytically and numerically. Approaches based on the Langevin approximation are often more tractable, but care must be used to ensure that it is justified in each situation. Here, we examine a model of an enzyme cycle for which noise qualitatively alters the behavior of the system: fluctuations in the population of an enzyme can result in amplification and multistability in the distribution of its product. We compare master equation and Langevin treatments of this system and show that results derived previously with a white noise Langevin equation [M. Samoilov et al., Proc. Natl. Acad. Sci. U.S.A. 102, 2310 (2005)] are inconsistent with the master equation. A colored noise Langevin equation captures some, but not all, of the essential physics of the system. The advantages and disadvantages of the Langevin approximation for modeling biological processes are discussed.
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Filtered shot noise processes have proven to be very effective in modeling the evolution of systems exposed to shot noise sources and have been applied to a wide variety of fields ranging from electronics through biology. In particular, they can model the membrane potential V(m) of neurons driven by stochastic input, where these filtered processes are able to capture the nonstationary characteristics of V(m) fluctuations in response to presynaptic input with variable rate. In this paper we apply the general framework of Poisson point processes transformations to analyze these systems in the general case of nonstationary input rates. We obtain exact analytic expressions, as well as different approximations, for the joint cumulants of filtered shot noise processes with multiplicative noise. These general results are then applied to a model of neuronal membranes subject to conductance shot noise with a continuously variable rate of presynaptic spikes. We propose very effective approximations for the time evolution of the V(m) distribution and a simple method to estimate the presynaptic rate from a small number of V(m) traces. This work opens the perspective of obtaining analytic access to important statistical properties of conductance-based neuronal models such as the first passage time.
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How noise statistics impact models of enzyme cycles.
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Theoretical tools for adequately treating stochastic effects are important for understanding their role in biological processes. Although master equations provide rigorous means for investigating effects associated with fluctuations of discrete molecular copy numbers, they can be very challenging to treat analytically and numerically. Approaches based on the Langevin approximation are often more tractable, but care must be used to ensure that it is justified in each situation. Here, we examine a model of an enzyme cycle for which noise qualitatively alters the behavior of the system: fluctuations in the population of an enzyme can result in amplification and multistability in the distribution of its product. We compare master equation and Langevin treatments of this system and show that results derived previously with a white noise Langevin equation [M. Samoilov et al., Proc. Natl. Acad. Sci. U.S.A. 102, 2310 (2005)] are inconsistent with the master equation. A colored noise Langevin equation captures some, but not all, of the essential physics of the system. The advantages and disadvantages of the Langevin approximation for modeling biological processes are discussed.
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Over the last few years, experimental data on the fluctuations in gene activity between individual cells and within the same cell over time have confirmed that gene expression is a "noisy" process. This variation is in part due to the small number of molecules taking part in some of the key reactions that are involved in gene expression. One of the consequences of this is that protein production often occurs in bursts, each due to a single promoter or transcription factor binding event. Recently, the distribution of the number of proteins produced in such bursts has been experimentally measured, offering a unique opportunity to study the relative importance of different sources of noise in gene expression. Here, we provide a derivation of the theoretical probability distribution of these bursts for a wide variety of different models of gene expression. We show that there is a good fit between our theoretical distribution and that obtained from two different published experimental datasets. We then prove that, irrespective of the details of the model, the burst size distribution is always geometric and hence determined by a single parameter. Many different combinations of the biochemical rates for the constituent reactions of both transcription and translation will therefore lead to the same experimentally observed burst size distribution. It is thus impossible to identify different sources of fluctuations purely from protein burst size data or to use such data to estimate all of the model parameters. We explore methods of inferring these values when additional types of experimental data are available.
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How noise statistics impact models of enzyme cycles.
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Theoretical tools for adequately treating stochastic effects are important for understanding their role in biological processes. Although master equations provide rigorous means for investigating effects associated with fluctuations of discrete molecular copy numbers, they can be very challenging to treat analytically and numerically. Approaches based on the Langevin approximation are often more tractable, but care must be used to ensure that it is justified in each situation. Here, we examine a model of an enzyme cycle for which noise qualitatively alters the behavior of the system: fluctuations in the population of an enzyme can result in amplification and multistability in the distribution of its product. We compare master equation and Langevin treatments of this system and show that results derived previously with a white noise Langevin equation [M. Samoilov et al., Proc. Natl. Acad. Sci. U.S.A. 102, 2310 (2005)] are inconsistent with the master equation. A colored noise Langevin equation captures some, but not all, of the essential physics of the system. The advantages and disadvantages of the Langevin approximation for modeling biological processes are discussed.
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We assess the impact of cell cycle noise on gene circuit dynamics. For bistable genetic switches and excitable circuits, we find that transitions between metastable states most likely occur just after cell division and that this concentration effect intensifies in the presence of transcriptional delay. We explain this concentration effect with a three-states stochastic model. For genetic oscillators, we quantify the temporal correlations between daughter cells induced by cell division. Temporal correlations must be captured properly in order to accurately quantify noise sources within gene networks.
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Morphological deformities in the invasive driftwood catfish Trachelyopterus galeatus in the Upper Paraná River basin, Brazil: a sign of human impact?
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In this study, the authors report morphological deformities in driftwood catfish Trachelyopterus galeatus (Auchenipteridae), an invasive catfish occurring in the Upper Paraná River basin, Brazil. The frequency of anomalous individuals reached 18.3% of all catches. X-ray images showed anomalies, or total absence of structures, in the pelvic girdle. The authors also observed the absence of the adipose fin and mental barbels. These findings are of extreme importance for evidencing the anthropogenic impact on aquatic communities as the region suffers within fragmentation by dams and pollution from several human activities. This sort of information can be used in management systems and environmental monitoring, especially to protect other species and the native fish assemblage.
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During the study of the metazoan parasites of fishes from Araguaia River, municipality of Araguatins (05 degrees 39'S, 48 degrees 07'W), State of Tocantins, Brazil, a third stage larvae of an undescribed species of Terranova were collected from the mesenteries of Plagioscion squamosissimus. These larvae were characterized to present large size, excretory pore situated near of the base of ventrolateral lips, presence of short intestinal caecum dorsal to oesophagus, ventriculus less than seven times as long as wide and absence of mucron. This is the first record and description of larval of species of Terranova parasitic in South American freshwater fishes.
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Morphological deformities in the invasive driftwood catfish Trachelyopterus galeatus in the Upper Paraná River basin, Brazil: a sign of human impact?
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In this study, the authors report morphological deformities in driftwood catfish Trachelyopterus galeatus (Auchenipteridae), an invasive catfish occurring in the Upper Paraná River basin, Brazil. The frequency of anomalous individuals reached 18.3% of all catches. X-ray images showed anomalies, or total absence of structures, in the pelvic girdle. The authors also observed the absence of the adipose fin and mental barbels. These findings are of extreme importance for evidencing the anthropogenic impact on aquatic communities as the region suffers within fragmentation by dams and pollution from several human activities. This sort of information can be used in management systems and environmental monitoring, especially to protect other species and the native fish assemblage.
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The Neotropical catfish genus Kronichthys contains three species distributed along coastal rivers of southern and southeastern Brazil. Although phylogenetic hypotheses are available, the molecular and morphological diversity and species boundaries within the genus remain unexplored. In this study, the authors generated mitochondrial data for 90 specimens combined with morphometric and meristic data to investigate species diversity, species boundaries and putative morphological signatures in Kronichthys. Phylogenetic and species delimitation results clearly show the presence of four genetic lineages, three within Kronichthys heylandi along the coast from Rio de Janeiro to southern São Paulo and a single lineage encompassing both the nominal species Kronichthys lacerta and Kronichthys subteres from the Ribeira de Iguape basin to Santa Catarina in southern Brazil. Nonetheless, morphological data show overlapped ranges in morphometrics and a definition of only two morphotypes, with clear phenotypic differences in the teeth number: K. heylandi differs from K. subteres + K. lacerta by the higher number of premaxillary teeth (30-52 vs. 19-28) and higher number of dentary teeth (28-54 vs. 17-28). Headwater captures and connections of paleodrainages because of sea-level fluctuations represent the two major biogeographic processes promoting species diversification and lineage dispersal of Kronichthys in the Atlantic coastal range of Brazil.
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Morphological deformities in the invasive driftwood catfish Trachelyopterus galeatus in the Upper Paraná River basin, Brazil: a sign of human impact?
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In this study, the authors report morphological deformities in driftwood catfish Trachelyopterus galeatus (Auchenipteridae), an invasive catfish occurring in the Upper Paraná River basin, Brazil. The frequency of anomalous individuals reached 18.3% of all catches. X-ray images showed anomalies, or total absence of structures, in the pelvic girdle. The authors also observed the absence of the adipose fin and mental barbels. These findings are of extreme importance for evidencing the anthropogenic impact on aquatic communities as the region suffers within fragmentation by dams and pollution from several human activities. This sort of information can be used in management systems and environmental monitoring, especially to protect other species and the native fish assemblage.
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The Guiana dolphin (Sotalia guianensis) is categorized as vulnerable in the Brazilian list of endangered animals, and its populations suffer from several anthropological threats. In this study, we analyzed the presence of macro, meso, and microplastics (MPs) in Guiana dolphins (n = 12) in Brazil Southeastern coast by analysing their gastrointestinal tract. The MP extractions were carried out with H<sub>2</sub>O<sub>2</sub> (35 %) to remove organic matter. Four specimens ingested meso and macroplastics, including an item of polypropylene of 19.22 cm that was produced about 943 km from the place in which the animal was found stranded. All the specimens analyzed had fragment-type microplastics in their intestines. Blue was the prevailing color, followed by black, green, and red. We highlight the contamination by microplastics in the species, still little investigated, especially the need to understand the contamination by microplastics along trophic levels.
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Morphological deformities in the invasive driftwood catfish Trachelyopterus galeatus in the Upper Paraná River basin, Brazil: a sign of human impact?
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In this study, the authors report morphological deformities in driftwood catfish Trachelyopterus galeatus (Auchenipteridae), an invasive catfish occurring in the Upper Paraná River basin, Brazil. The frequency of anomalous individuals reached 18.3% of all catches. X-ray images showed anomalies, or total absence of structures, in the pelvic girdle. The authors also observed the absence of the adipose fin and mental barbels. These findings are of extreme importance for evidencing the anthropogenic impact on aquatic communities as the region suffers within fragmentation by dams and pollution from several human activities. This sort of information can be used in management systems and environmental monitoring, especially to protect other species and the native fish assemblage.
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The ectoparasitic copepod Lernaea cyprinacea (anchor worm) has more than 100 host species among teleost fishes and affects cyprinids both in fish farms and natural waters. In addition, while L. cyprinacea infection in amphibians has been recorded in Asia, North and South America, there is no data available in the literature on their presence in Europe. In this study, we first reported L. cf. cyprinacea parasitising an anuran tadpole in Europe. Specimens of L. cf. cyprinacea were observed attached to a tadpole of the agile frog (Rana dalmatina), which was caught during fishing of crucian carp fingerlings (Carassius carassius) from a small fish pond in Hungary during the summer of 2012. The infected tadpole was collected from a rearing pond, where juvenile crucian carps were kept. The tadpole was inspected in the laboratory, and digital photos were taken. The parasites were found attached to the body-tail junction and to the leg of the tadpole (at Gosner stage 41). The parasite species was identified as L. cf. cyprinacea based on morphological traits.
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Morphological deformities in the invasive driftwood catfish Trachelyopterus galeatus in the Upper Paraná River basin, Brazil: a sign of human impact?
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In this study, the authors report morphological deformities in driftwood catfish Trachelyopterus galeatus (Auchenipteridae), an invasive catfish occurring in the Upper Paraná River basin, Brazil. The frequency of anomalous individuals reached 18.3% of all catches. X-ray images showed anomalies, or total absence of structures, in the pelvic girdle. The authors also observed the absence of the adipose fin and mental barbels. These findings are of extreme importance for evidencing the anthropogenic impact on aquatic communities as the region suffers within fragmentation by dams and pollution from several human activities. This sort of information can be used in management systems and environmental monitoring, especially to protect other species and the native fish assemblage.
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The aim of this study was to evaluate the impacts of metazoan parasites on hematological and biochemical parameters and relative condition factor of tambaqui (Colossoma macropomum ) farmed in northern Brazil. A total of 32 juvenile fish were captured from a commercial fish farm located in the municipality of Rio Preto da Eva, Amazonas state, Brazil. Parasite prevalence was 100% for Anacanthorus spathulatus, Mymarothecium boegeri and Notozothecium janauachensis, 100% for Neoechinorhynchus buttnerae and 53.13% for Dolops geayi. The greatest mean parasite intensity was found in acantocephalans followed by monogeneans and branchiuran crustaceans. A negative correlation was observed between abundance of N. buttnerae and hematocrit percentage, hemoglobin concentration, total thrombocyte count and glucose and between abundance of the monogenean and glucose concentration. Parasitic infections caused damage in tambaqui in terms of the observed hematological parameters that were characterized by hypochromic anemia and thrombocytopenia, which are important parameters to be used in parasitic diagnosis. This study is the first record of the occurrence of Dolops geayi in farmed tambaqui in the Amazon.
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Gene identification and analysis of transcripts differentially regulated in fracture healing by EST sequencing in the domestic sheep.
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The sheep is an important model animal for testing novel fracture treatments and other medical applications. Despite these medical uses and the well known economic and cultural importance of the sheep, relatively little research has been performed into sheep genetics, and DNA sequences are available for only a small number of sheep genes.
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Increasing age negatively affects different phases of bone fracture healing. The present study aimed to explore underlying mechanisms related to bone fracture repair in the elderly. GSE17825 public transcriptome data from the Gene Expression Omnibus database were used for analysis. First, raw data were normalized and differentially expressed genes (DEGs) were identified. Next, Kyoto Encyclopedia of Genes and Genomes (KEGG) and Gene Ontology (GO) analyses were implemented to evaluate pathways and DEGs. A protein-protein interaction (PPI) network was then constructed. A total of 726, 861, and 432 DEGs were identified between the young and elderly individuals at 1, 3, and 5 days after fracture, respectively. The results of GO, KEGG, and PPI network analyses suggested that the inflammatory response, Wnt signaling pathway, vascularization-associated processes, and synaptic-related functions of the identified DEGs are markedly enriched, which may account for delayed fracture healing in the elderly. These findings provide valuable clues for investigating the effects of aging on fracture healing but should be validated through further experiments.
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Gene identification and analysis of transcripts differentially regulated in fracture healing by EST sequencing in the domestic sheep.
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The sheep is an important model animal for testing novel fracture treatments and other medical applications. Despite these medical uses and the well known economic and cultural importance of the sheep, relatively little research has been performed into sheep genetics, and DNA sequences are available for only a small number of sheep genes.
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The dynamic synergy of genes and pathways in muscles in relation to age affects the muscle characteristics. Investigating the temporal changes in gene expression will help illustrate the molecular mechanisms underlying muscle development. Here we report the gene expression changes in skeletal muscles through successive age groups in Bandur, a meat type sheep of India. RNA sequencing data was generated from the longissimus thoracis muscles from four age groups, ranging from lamb to adult. Analysis of 20 highest expressed genes common across the groups revealed muscle protein, phosphorylation, acetylation, metal binding and transport as significant functions. Maximum differentiation was observed after 2.5-3 years on transition from lambs to adult. Transcriptional regulation by the TFAP2 transcription factors, IL-6 signaling and PI3K/AKT signaling pathways were enriched in younger animals. The gene-protein network demarcated key interactive genes involved in muscle development and proliferation that can be used as candidates for future research on improvement of muscle characteristics.
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Gene identification and analysis of transcripts differentially regulated in fracture healing by EST sequencing in the domestic sheep.
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The sheep is an important model animal for testing novel fracture treatments and other medical applications. Despite these medical uses and the well known economic and cultural importance of the sheep, relatively little research has been performed into sheep genetics, and DNA sequences are available for only a small number of sheep genes.
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The analysis of global gene expression changes is a valuable tool for identifying novel pathways underlying observed phenotypes. The zebrafish is an excellent model for rapid assessment of whole transcriptome from whole animal or individual cell populations due to the ease of isolation of RNA from large numbers of animals. Here a protocol for global gene expression analysis in zebrafish embryos using RNA sequencing (RNASeq) is presented. We describe preparation of RNA from whole embryos or from cell populations obtained using cell sorting in transgenic animals. We also describe an approach for analysis of RNASeq data to identify enriched pathways and Gene Ontology (GO) terms in global gene expression data sets. Finally, we provide a protocol for validation of gene expression changes using quantitative reverse transcriptase PCR (qRT-PCR). These protocols can be used for comparative analysis of control and experimental sets of zebrafish to identify novel gene expression changes, and provide molecular insight into phenotypes of interest.
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Gene identification and analysis of transcripts differentially regulated in fracture healing by EST sequencing in the domestic sheep.
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The sheep is an important model animal for testing novel fracture treatments and other medical applications. Despite these medical uses and the well known economic and cultural importance of the sheep, relatively little research has been performed into sheep genetics, and DNA sequences are available for only a small number of sheep genes.
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Antler is the fastest growing and ossifying tissue in animals and it is a valuable model for cartilage/bone development. To understand the molecular mechanisms of chondrogenesis and osteogenesis of antlers, the PacBio Sequel II and Illumina sequencing technology were combined and used to investigate the mRNA expression profiles in antler tip, middle, and base at six different developmental stages, i.e., at 15th, 25th, 45th, 65th, 100th and 130th growth days. Consequently, we identified 24,856 genes (FPKM > 0.1), including 8778 novel genes. Besides, principal component analysis (PCA) revealed a significant separation between the growth stage (25th, 45th and 65th days) and ossification stage (100th and 130th days). COL2A1 gene was significantly abundant in the growth stage, whereas S100A7, S100A12, S100A8, and WFDC18 genes were abundant at the ossification stage. Subsequently screened to 14,765 significantly differentially expressed genes (DEGs), WGCNA and GO functional enrichment analyses revealed that genes related to cell division and chondrocyte differentiation were up-regulated, whereas those with steroid hormone-mediated signaling pathways were down-regulated at ossification stages. Additionally, 25 tumor suppressor genes and 11 oncogenes were identified and were predicted to interact with p53. Co-regulation of tumor suppressor genes and oncogenes is responsible for the special growth pattern of antlers. Together, we constructed the most complete sika deer antler transcriptome database so far. The database provides data support for subsequent studies on the molecular mechanism of sika deer antler chondrogenesis and osteogenesis.
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Gene identification and analysis of transcripts differentially regulated in fracture healing by EST sequencing in the domestic sheep.
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The sheep is an important model animal for testing novel fracture treatments and other medical applications. Despite these medical uses and the well known economic and cultural importance of the sheep, relatively little research has been performed into sheep genetics, and DNA sequences are available for only a small number of sheep genes.
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Transcriptome experiments are performed to assess protein abundance through mRNA expression analysis. Expression levels of genes vary depending on the experimental conditions and the cell response. Transcriptome data must be diverse and yet comparable in reference to stably expressed genes, even if they are generated from different experiments on the same biological context from various laboratories. In this study, expression patterns of 9090 microarray samples grouped into 381 NCBI-GEO datasets were investigated to identify novel candidate reference genes using randomizations and Receiver Operating Characteristic (ROC) curves. The analysis demonstrated that cell type specific reference gene sets display less variability than a united set for all tissues. Therefore, constitutively and stably expressed, origin specific novel reference gene sets were identified based on their coefficient of variation and percentage of occurrence in all GEO datasets, which were classified using Medical Subject Headings (MeSH). A large number of MeSH grouped reference gene lists are presented as novel tissue specific reference gene lists. The most commonly observed 17 genes in these sets were compared for their expression in 8 hepatocellular, 5 breast and 3 colon carcinoma cells by RT-qPCR to verify tissue specificity. Indeed, commonly used housekeeping genes GAPDH, Actin and EEF2 had tissue specific variations, whereas several ribosomal genes were among the most stably expressed genes in vitro. Our results confirm that two or more reference genes should be used in combination for differential expression analysis of large-scale data obtained from microarray or next generation sequencing studies. Therefore context dependent reference gene sets, as presented in this study, are required for normalization of expression data from diverse technological backgrounds.
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Avoidance of the NLRP3 Inflammasome by the Stealth Pathogen, <i>Coxiella burnetii</i>.
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<i>Coxiella burnetii</i>, a highly adapted obligate intracellular bacterial pathogen and the cause of the zoonosis Q fever, is a reemerging public health threat. <i>C. burnetii</i> employs a Type IV secretion system (T4SS) to establish and maintain its intracellular niche and modulate host immune responses including the inhibition of apoptosis. Interactions between <i>C. burnetii</i> and caspase-1-mediated inflammasomes are not fully elucidated. This study confirms that <i>C. burnetii</i> does not activate caspase-1 during infection of mouse macrophages in vitro. <i>C. burnetii</i>-infected cells did not develop NLRP3 and ASC foci indicating its ability to avoid cytosolic detection. <i>C. burnetii</i> is unable to inhibit the pyroptosis and IL-1β secretion that is induced by potent inflammasome stimuli but rather enhances these caspase-1-mediated effects. We found that <i>C. burnetii</i> upregulates pro-IL-1β and robustly primes NLRP3 inflammasomes via TLR2 and MyD88 signaling. As for wildtype <i>C. burnetii</i>, T4SS-deficient mutants primed and potentiated NLRP3 inflammasomes. An in vivo model of pulmonary infection in C57BL/6 mice was developed. Mice deficient in NLRP3 or caspase-1 were like wildtype mice in the development and resolution of splenomegaly due to red pulp hyperplasia, and histologic lesions and macrophage kinetics, but had slightly higher pulmonary bacterial burdens at the greatest measured time point. Together these findings indicate that <i>C. burnetii</i> primes but avoids cytosolic detection by NLRP3 inflammasomes, which are not required for the clinical resistance of C57BL/6 mice. Determining mechanisms employed by <i>C. burnetii</i> to avoid cytosolic detection via NLRP3 inflammasomes will be beneficial to the development of preventative and interventional therapies for Q fever.
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Coxiella burnetii is a highly infectious bacterial pathogen that replicates in a specialized vacuole inside eukaryotic cells. Due to a prolonged growth cycle, Coxiella continuously manipulates cellular processes to generate this parasitophorous vacuole (PV) and promote host cell viability. Here, we discuss recent findings that indicate Coxiella modulates several host signaling pathways to influence survival and ensure intracellular replication. The pathogen actively inhibits apoptotic cell death and activates the pro-survival kinases Akt and Erk1/2 to promote host viability. Coxiella's anti-apoptotic activity also involves the interface between autophagy and apoptosis, which is regulated by the interaction of autophagy-related Beclin-1 and anti-apoptotic Bcl-2. Additionally, Coxiella requires host kinase activity for PV biogenesis and maintenance. Thus, signaling modulation by Coxiella is critical for multiple aspects of host cell parasitism. Collectively, recent signaling studies have enhanced our understanding of the unique Coxiella-host cell interaction. Identification of bacterial factors that regulate signaling events will further our ability to model this intriguing infectious process.
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Avoidance of the NLRP3 Inflammasome by the Stealth Pathogen, <i>Coxiella burnetii</i>.
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<i>Coxiella burnetii</i>, a highly adapted obligate intracellular bacterial pathogen and the cause of the zoonosis Q fever, is a reemerging public health threat. <i>C. burnetii</i> employs a Type IV secretion system (T4SS) to establish and maintain its intracellular niche and modulate host immune responses including the inhibition of apoptosis. Interactions between <i>C. burnetii</i> and caspase-1-mediated inflammasomes are not fully elucidated. This study confirms that <i>C. burnetii</i> does not activate caspase-1 during infection of mouse macrophages in vitro. <i>C. burnetii</i>-infected cells did not develop NLRP3 and ASC foci indicating its ability to avoid cytosolic detection. <i>C. burnetii</i> is unable to inhibit the pyroptosis and IL-1β secretion that is induced by potent inflammasome stimuli but rather enhances these caspase-1-mediated effects. We found that <i>C. burnetii</i> upregulates pro-IL-1β and robustly primes NLRP3 inflammasomes via TLR2 and MyD88 signaling. As for wildtype <i>C. burnetii</i>, T4SS-deficient mutants primed and potentiated NLRP3 inflammasomes. An in vivo model of pulmonary infection in C57BL/6 mice was developed. Mice deficient in NLRP3 or caspase-1 were like wildtype mice in the development and resolution of splenomegaly due to red pulp hyperplasia, and histologic lesions and macrophage kinetics, but had slightly higher pulmonary bacterial burdens at the greatest measured time point. Together these findings indicate that <i>C. burnetii</i> primes but avoids cytosolic detection by NLRP3 inflammasomes, which are not required for the clinical resistance of C57BL/6 mice. Determining mechanisms employed by <i>C. burnetii</i> to avoid cytosolic detection via NLRP3 inflammasomes will be beneficial to the development of preventative and interventional therapies for Q fever.
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The organism needs to tailor the intestinal inflammatory response to pathogenic bacteria and to pathobionts that are only occasionally pathogenic. In this issue of Immunity, Seo et al. (2015) show that the pathobiont Proteus mirabilis induces NLRP3 inflammasome-dependent interleukin-1β (IL-1β) release from CCR2(+) Ly6C(high) inflammatory monocytes.
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Avoidance of the NLRP3 Inflammasome by the Stealth Pathogen, <i>Coxiella burnetii</i>.
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<i>Coxiella burnetii</i>, a highly adapted obligate intracellular bacterial pathogen and the cause of the zoonosis Q fever, is a reemerging public health threat. <i>C. burnetii</i> employs a Type IV secretion system (T4SS) to establish and maintain its intracellular niche and modulate host immune responses including the inhibition of apoptosis. Interactions between <i>C. burnetii</i> and caspase-1-mediated inflammasomes are not fully elucidated. This study confirms that <i>C. burnetii</i> does not activate caspase-1 during infection of mouse macrophages in vitro. <i>C. burnetii</i>-infected cells did not develop NLRP3 and ASC foci indicating its ability to avoid cytosolic detection. <i>C. burnetii</i> is unable to inhibit the pyroptosis and IL-1β secretion that is induced by potent inflammasome stimuli but rather enhances these caspase-1-mediated effects. We found that <i>C. burnetii</i> upregulates pro-IL-1β and robustly primes NLRP3 inflammasomes via TLR2 and MyD88 signaling. As for wildtype <i>C. burnetii</i>, T4SS-deficient mutants primed and potentiated NLRP3 inflammasomes. An in vivo model of pulmonary infection in C57BL/6 mice was developed. Mice deficient in NLRP3 or caspase-1 were like wildtype mice in the development and resolution of splenomegaly due to red pulp hyperplasia, and histologic lesions and macrophage kinetics, but had slightly higher pulmonary bacterial burdens at the greatest measured time point. Together these findings indicate that <i>C. burnetii</i> primes but avoids cytosolic detection by NLRP3 inflammasomes, which are not required for the clinical resistance of C57BL/6 mice. Determining mechanisms employed by <i>C. burnetii</i> to avoid cytosolic detection via NLRP3 inflammasomes will be beneficial to the development of preventative and interventional therapies for Q fever.
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<i>Coxiella burnetii</i> is an intracellular pathogen responsible for causing Q fever in humans, a disease with varied presentations ranging from a mild flu-like sickness to a debilitating illness that can result in endocarditis. The intracellular lifestyle of <i>C. burnetii</i> is unique, residing in an acidic phagolysosome-like compartment within host cells. An understanding of the core molecular biology of <i>C. burnetii</i> will greatly increase our understanding of <i>C. burnetii</i> growth, survival and pathogenesis. We used transposon-directed insertion site sequencing (TraDIS) to reveal <i>C. burnetii</i> Nine Mile Phase II genes fundamental for growth and <i>in vitro</i> survival. Screening a transposon library containing >10 000 unique transposon mutants revealed 512 predicted essential genes. Essential routes of synthesis were identified for the mevalonate pathway, as well as peptidoglycan and biotin synthesis. Some essential genes identified (e.g. predicted type IV secretion system effector genes) are typically considered to be associated with <i>C. burnetii</i> virulence, a caveat concerning the axenic media used in the study. Investigation into the conservation of the essential genes identified revealed that 78 % are conserved across all <i>C. burnetii</i> strains sequenced to date, which probably play critical functions. This is the first report of a whole genome transposon screen in <i>C. burnetii</i> that has been undertaken for the identification of essential genes.
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Avoidance of the NLRP3 Inflammasome by the Stealth Pathogen, <i>Coxiella burnetii</i>.
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<i>Coxiella burnetii</i>, a highly adapted obligate intracellular bacterial pathogen and the cause of the zoonosis Q fever, is a reemerging public health threat. <i>C. burnetii</i> employs a Type IV secretion system (T4SS) to establish and maintain its intracellular niche and modulate host immune responses including the inhibition of apoptosis. Interactions between <i>C. burnetii</i> and caspase-1-mediated inflammasomes are not fully elucidated. This study confirms that <i>C. burnetii</i> does not activate caspase-1 during infection of mouse macrophages in vitro. <i>C. burnetii</i>-infected cells did not develop NLRP3 and ASC foci indicating its ability to avoid cytosolic detection. <i>C. burnetii</i> is unable to inhibit the pyroptosis and IL-1β secretion that is induced by potent inflammasome stimuli but rather enhances these caspase-1-mediated effects. We found that <i>C. burnetii</i> upregulates pro-IL-1β and robustly primes NLRP3 inflammasomes via TLR2 and MyD88 signaling. As for wildtype <i>C. burnetii</i>, T4SS-deficient mutants primed and potentiated NLRP3 inflammasomes. An in vivo model of pulmonary infection in C57BL/6 mice was developed. Mice deficient in NLRP3 or caspase-1 were like wildtype mice in the development and resolution of splenomegaly due to red pulp hyperplasia, and histologic lesions and macrophage kinetics, but had slightly higher pulmonary bacterial burdens at the greatest measured time point. Together these findings indicate that <i>C. burnetii</i> primes but avoids cytosolic detection by NLRP3 inflammasomes, which are not required for the clinical resistance of C57BL/6 mice. Determining mechanisms employed by <i>C. burnetii</i> to avoid cytosolic detection via NLRP3 inflammasomes will be beneficial to the development of preventative and interventional therapies for Q fever.
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Caspases have important functions beyond their established role in driving inflammation and apoptosis. In this issue of Immunity, Wang et al. (2017) demonstrate that inflammasome-triggered caspases cleave and inactivate the DNA sensor cGAS, thus restricting the type I interferon response to cytosolic DNA.
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Avoidance of the NLRP3 Inflammasome by the Stealth Pathogen, <i>Coxiella burnetii</i>.
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<i>Coxiella burnetii</i>, a highly adapted obligate intracellular bacterial pathogen and the cause of the zoonosis Q fever, is a reemerging public health threat. <i>C. burnetii</i> employs a Type IV secretion system (T4SS) to establish and maintain its intracellular niche and modulate host immune responses including the inhibition of apoptosis. Interactions between <i>C. burnetii</i> and caspase-1-mediated inflammasomes are not fully elucidated. This study confirms that <i>C. burnetii</i> does not activate caspase-1 during infection of mouse macrophages in vitro. <i>C. burnetii</i>-infected cells did not develop NLRP3 and ASC foci indicating its ability to avoid cytosolic detection. <i>C. burnetii</i> is unable to inhibit the pyroptosis and IL-1β secretion that is induced by potent inflammasome stimuli but rather enhances these caspase-1-mediated effects. We found that <i>C. burnetii</i> upregulates pro-IL-1β and robustly primes NLRP3 inflammasomes via TLR2 and MyD88 signaling. As for wildtype <i>C. burnetii</i>, T4SS-deficient mutants primed and potentiated NLRP3 inflammasomes. An in vivo model of pulmonary infection in C57BL/6 mice was developed. Mice deficient in NLRP3 or caspase-1 were like wildtype mice in the development and resolution of splenomegaly due to red pulp hyperplasia, and histologic lesions and macrophage kinetics, but had slightly higher pulmonary bacterial burdens at the greatest measured time point. Together these findings indicate that <i>C. burnetii</i> primes but avoids cytosolic detection by NLRP3 inflammasomes, which are not required for the clinical resistance of C57BL/6 mice. Determining mechanisms employed by <i>C. burnetii</i> to avoid cytosolic detection via NLRP3 inflammasomes will be beneficial to the development of preventative and interventional therapies for Q fever.
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Pathogens frequently exist in an immunological balancing act with their host. Pathogens must not only replicate within a host but also transmit effectively between hosts to perpetuate their species. On the other hand, the host seeks to maintain homeostasis by clearing pathogens. The inflammasome is a multi-protein complex that can induce cell death and processes IL-1β and additional proinflammatory substrates. In this review we discuss the pathogen specific modulation of inflammasome activation and the role this plays in virulence and disease pathology.
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AAL Service Performance Measurement Cube - Key Criteria for AAL New Service Development.
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The living environments of senior citizens are gaining in complexity with regard to health, mobility, information, support and behaviour. The development of Ambient Assisted Living (AAL) services in order to reduce this complexity is becoming increasingly important. The question is: What relevant criteria support the development, measurement and evaluation of business models of hybrid AAL services which have to be considered in an appropriate Performance Measurement Set? Within the EU funded research project DALIA (Assistant for Daily Life Activities at Home) a Service Performance Measurement Criteria (SPMC) Set has been developed and described. With the help of literature review and expert interviews relevant performance criteria were identified and described in the context of Analytic Hierarchy Process (AHP). In conjunction with an AAL business models scanning, a set of performance measurement criteria could be created.
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The study aimed to establish recommendations and quality criteria to enhance the healthcare process of PBC.
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AAL Service Performance Measurement Cube - Key Criteria for AAL New Service Development.
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The living environments of senior citizens are gaining in complexity with regard to health, mobility, information, support and behaviour. The development of Ambient Assisted Living (AAL) services in order to reduce this complexity is becoming increasingly important. The question is: What relevant criteria support the development, measurement and evaluation of business models of hybrid AAL services which have to be considered in an appropriate Performance Measurement Set? Within the EU funded research project DALIA (Assistant for Daily Life Activities at Home) a Service Performance Measurement Criteria (SPMC) Set has been developed and described. With the help of literature review and expert interviews relevant performance criteria were identified and described in the context of Analytic Hierarchy Process (AHP). In conjunction with an AAL business models scanning, a set of performance measurement criteria could be created.
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Accrediting organizations require laboratories to establish analytic performance criteria that ensure their tests provide results of the high quality required for patient care. However, the procedures for instituting performance criteria that are directly linked to the needs of medical practice are not well established, and therefore alternative strategies often are used to create and implement surrogate performance standards. We reviewed six approaches for establishing outcome-related analytic performance goals: (a) limits defined by regulations and external assessment programs, (b) limits based on biologic variation, (c) limits based on surveys of clinicians about their needs, (d) limits based on effects on guideline driven medical decisions, (e) limits based on analysis of patterns for ordering follow-up clinical tests, and (f) limits based on formal medical decision models. Performance criteria were tabulated for 12 common chemistry analytes and four routine hematology tests. There is no consensus currently about the preferred methods for establishing medically necessary analytic performance limits. The various methods reviewed give considerably different performance limits. The analytic performance limits claimed by a laboratory should correspond to those limits that can be reliably maintained based on validated QC monitoring systems. These limits generally are larger than the observed CVs and bias parameters collected for assay validation. There is a major need for increased communication among laboratorians and clinicians on this topic, especially when the analytic performance limits that can be consistently maintained by a laboratory are inconsistent with the expectations of health care providers.
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AAL Service Performance Measurement Cube - Key Criteria for AAL New Service Development.
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The living environments of senior citizens are gaining in complexity with regard to health, mobility, information, support and behaviour. The development of Ambient Assisted Living (AAL) services in order to reduce this complexity is becoming increasingly important. The question is: What relevant criteria support the development, measurement and evaluation of business models of hybrid AAL services which have to be considered in an appropriate Performance Measurement Set? Within the EU funded research project DALIA (Assistant for Daily Life Activities at Home) a Service Performance Measurement Criteria (SPMC) Set has been developed and described. With the help of literature review and expert interviews relevant performance criteria were identified and described in the context of Analytic Hierarchy Process (AHP). In conjunction with an AAL business models scanning, a set of performance measurement criteria could be created.
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Organisational performance measurement is a recognised business management tool and essential for survival and success. There is a paucity of methodological studies of organisational performance measurement relating to non-acute healthcare charities and this study is the first to suggest a set of evidence-informed organisational performance measures for the sector.
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AAL Service Performance Measurement Cube - Key Criteria for AAL New Service Development.
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The living environments of senior citizens are gaining in complexity with regard to health, mobility, information, support and behaviour. The development of Ambient Assisted Living (AAL) services in order to reduce this complexity is becoming increasingly important. The question is: What relevant criteria support the development, measurement and evaluation of business models of hybrid AAL services which have to be considered in an appropriate Performance Measurement Set? Within the EU funded research project DALIA (Assistant for Daily Life Activities at Home) a Service Performance Measurement Criteria (SPMC) Set has been developed and described. With the help of literature review and expert interviews relevant performance criteria were identified and described in the context of Analytic Hierarchy Process (AHP). In conjunction with an AAL business models scanning, a set of performance measurement criteria could be created.
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Program evaluations in schools of nursing (SONs) serve the purpose of clearly demonstrating how the SON meets the quality standards established by governance, regulatory, and accreditation bodies. The authors describe the step-by-step process taken by a SON to develop a new model of an evaluation protocol that includes linkages to external criteria for evaluation of the plan itself. This analysis and feedback step is often neglected but is essential to the quality improvement process.
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AAL Service Performance Measurement Cube - Key Criteria for AAL New Service Development.
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The living environments of senior citizens are gaining in complexity with regard to health, mobility, information, support and behaviour. The development of Ambient Assisted Living (AAL) services in order to reduce this complexity is becoming increasingly important. The question is: What relevant criteria support the development, measurement and evaluation of business models of hybrid AAL services which have to be considered in an appropriate Performance Measurement Set? Within the EU funded research project DALIA (Assistant for Daily Life Activities at Home) a Service Performance Measurement Criteria (SPMC) Set has been developed and described. With the help of literature review and expert interviews relevant performance criteria were identified and described in the context of Analytic Hierarchy Process (AHP). In conjunction with an AAL business models scanning, a set of performance measurement criteria could be created.
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To develop a proposal for a nursing panel of indicators based on the guiding principles of Balanced Scorecard.
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[Expression of TRAF-6,TAK1 and TGF-β mRNA in peripheral blood mononuclear cells of patients with diffuse large B cell lymphoma before and after chemotherapy].
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This study was purposed to detect the expression levels of TRAF6, TAK1 and TGF-β mRNA in peripheral blood mononuclear cell (PBMNC) of patients with diffuse large B cell lymphoma (DLBCL) before and after chemotherapy, and to explore the effect of chemotherapy on the activity of TRAF6/TAK1 signal pathway. The expression levels of TRAF-6, TAK1 and TGF-β mRNA in PBMNC of 38 patients with DLBCL were detected by using the quantitative real time PCR before treatment or after two cycles of chemotherapy, 12 healthy people were served as the control. The results showed that the expression levels of TRAF-6, TAK1 and TGF-β mRNA in PBMNC of DLBCL patients' were higher than those in healthy people. Before treatment, the expression levels of TRAF-6 and TAK1 mRNA had no significant difference as compared with healthy people (P > 0.05); after chemotherapy, the expression levels of these two genes significantly increased, and the differences both had statistically significant as compared with healthy people (P < 0.05); meanwhile the increased expression levels of these two genes after chemotherapy had statistically significant difference as compared with levels before treatment (P < 0.05) , and those expression levels were positively correlated. While the expression level of TGF-β mRNA decreased after chemotherapy as compared with level before treatment, and the differences had statistically significantse(P < 0.05). It is concluded that the activity of TRF6/TAK1 signal pathways in PBMNC of DLBCL patients' significantly increases after chemotherapy, while the expression level of TGF-β mRNA after chemotherapy is abviously lower than level before treatment.
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To study the CDR3 spectratyping and clonal expansion of T cells in the peripheral blood mononuclear cells (PBMCs) of patients with beta-mediterranean anemia patient undergoing allogeneic peripheral blood stem cell (PBSC) transplantation.
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[Expression of TRAF-6,TAK1 and TGF-β mRNA in peripheral blood mononuclear cells of patients with diffuse large B cell lymphoma before and after chemotherapy].
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This study was purposed to detect the expression levels of TRAF6, TAK1 and TGF-β mRNA in peripheral blood mononuclear cell (PBMNC) of patients with diffuse large B cell lymphoma (DLBCL) before and after chemotherapy, and to explore the effect of chemotherapy on the activity of TRAF6/TAK1 signal pathway. The expression levels of TRAF-6, TAK1 and TGF-β mRNA in PBMNC of 38 patients with DLBCL were detected by using the quantitative real time PCR before treatment or after two cycles of chemotherapy, 12 healthy people were served as the control. The results showed that the expression levels of TRAF-6, TAK1 and TGF-β mRNA in PBMNC of DLBCL patients' were higher than those in healthy people. Before treatment, the expression levels of TRAF-6 and TAK1 mRNA had no significant difference as compared with healthy people (P > 0.05); after chemotherapy, the expression levels of these two genes significantly increased, and the differences both had statistically significant as compared with healthy people (P < 0.05); meanwhile the increased expression levels of these two genes after chemotherapy had statistically significant difference as compared with levels before treatment (P < 0.05) , and those expression levels were positively correlated. While the expression level of TGF-β mRNA decreased after chemotherapy as compared with level before treatment, and the differences had statistically significantse(P < 0.05). It is concluded that the activity of TRF6/TAK1 signal pathways in PBMNC of DLBCL patients' significantly increases after chemotherapy, while the expression level of TGF-β mRNA after chemotherapy is abviously lower than level before treatment.
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To analyze the expression and its promoter methylation of chemokine CXC ligand 14 (CXCL14) in peripheral blood mononuclear cells (PBMCs) from patients with systemic lupus erythematosus (SLE).
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[Expression of TRAF-6,TAK1 and TGF-β mRNA in peripheral blood mononuclear cells of patients with diffuse large B cell lymphoma before and after chemotherapy].
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This study was purposed to detect the expression levels of TRAF6, TAK1 and TGF-β mRNA in peripheral blood mononuclear cell (PBMNC) of patients with diffuse large B cell lymphoma (DLBCL) before and after chemotherapy, and to explore the effect of chemotherapy on the activity of TRAF6/TAK1 signal pathway. The expression levels of TRAF-6, TAK1 and TGF-β mRNA in PBMNC of 38 patients with DLBCL were detected by using the quantitative real time PCR before treatment or after two cycles of chemotherapy, 12 healthy people were served as the control. The results showed that the expression levels of TRAF-6, TAK1 and TGF-β mRNA in PBMNC of DLBCL patients' were higher than those in healthy people. Before treatment, the expression levels of TRAF-6 and TAK1 mRNA had no significant difference as compared with healthy people (P > 0.05); after chemotherapy, the expression levels of these two genes significantly increased, and the differences both had statistically significant as compared with healthy people (P < 0.05); meanwhile the increased expression levels of these two genes after chemotherapy had statistically significant difference as compared with levels before treatment (P < 0.05) , and those expression levels were positively correlated. While the expression level of TGF-β mRNA decreased after chemotherapy as compared with level before treatment, and the differences had statistically significantse(P < 0.05). It is concluded that the activity of TRF6/TAK1 signal pathways in PBMNC of DLBCL patients' significantly increases after chemotherapy, while the expression level of TGF-β mRNA after chemotherapy is abviously lower than level before treatment.
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The properties of bone marrow (BM)-derived multipotent mesenchymal stromal cells (MSCs) are altered in the patients with the diffuse large B cell lymphoma (DLBCL) without BM involvement. It was suggested that plasma from the patients contains soluble factors that affect MSCs. Plasma and BM-derived MSCs from the DLBCL patients at the onset of the disease and one month after the end of treatment were studied. Concentration of the plasma cytokines and gene expression in the MSCs were evaluated by the Bio-Plex Pro Human Cytokine Panel kit to measure 27 analytes and real-time PCR. Plasma and MSCs from the healthy donors were used as controls. Analysis of cytokines in the plasma from healthy donors and patients before and one month after the end of treatment revealed significant differences in the concentration of 14 out of 27 cytokines. Correlations between the levels of secreted cytokines were altered in the plasma from patients indicating that the immune response regulation was disturbed. Cultivation of the MSCs from the healthy donors in the medium supplemented with the plasma from patients led to the changes in the MSC properties, similar to those observed in the MSCs from patients. The BM-derived MSCs were shown to participate in the humoral changes occurring in the DLBCL patients. For the first time, it was shown that the precursors of the stromal microenvironment - multipotent mesenchymal stromal cells - are altered in the patients with DLBCL without bone marrow involvement due to the humoral effect of the tumor and the response of organism to it. Comprehensive analysis of the results shows that, when remission is achieved in the patients with DLBCL, composition of the plasma cytokines normalizes, but does not reach the level observed in the healthy donors. The discovery of a new aspect of the effect of the tumor B-cells on the organism could help to reveal general regularities of the humoral effect of various tumors on the bone marrow stromal cells.
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[Expression of TRAF-6,TAK1 and TGF-β mRNA in peripheral blood mononuclear cells of patients with diffuse large B cell lymphoma before and after chemotherapy].
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This study was purposed to detect the expression levels of TRAF6, TAK1 and TGF-β mRNA in peripheral blood mononuclear cell (PBMNC) of patients with diffuse large B cell lymphoma (DLBCL) before and after chemotherapy, and to explore the effect of chemotherapy on the activity of TRAF6/TAK1 signal pathway. The expression levels of TRAF-6, TAK1 and TGF-β mRNA in PBMNC of 38 patients with DLBCL were detected by using the quantitative real time PCR before treatment or after two cycles of chemotherapy, 12 healthy people were served as the control. The results showed that the expression levels of TRAF-6, TAK1 and TGF-β mRNA in PBMNC of DLBCL patients' were higher than those in healthy people. Before treatment, the expression levels of TRAF-6 and TAK1 mRNA had no significant difference as compared with healthy people (P > 0.05); after chemotherapy, the expression levels of these two genes significantly increased, and the differences both had statistically significant as compared with healthy people (P < 0.05); meanwhile the increased expression levels of these two genes after chemotherapy had statistically significant difference as compared with levels before treatment (P < 0.05) , and those expression levels were positively correlated. While the expression level of TGF-β mRNA decreased after chemotherapy as compared with level before treatment, and the differences had statistically significantse(P < 0.05). It is concluded that the activity of TRF6/TAK1 signal pathways in PBMNC of DLBCL patients' significantly increases after chemotherapy, while the expression level of TGF-β mRNA after chemotherapy is abviously lower than level before treatment.
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Activated B-cell-like (ABC) subtype of diffuse large B-cell lymphoma (DLBCL) is characterized by chronic active B-cell receptor signaling and a constitutive activation of the NF-KB pathway. MYD88 L265P mutation occurs as a driving force of NF-KB overactivity in ABC-DLBCL. Nonetheless, in cases of DLBCL, the MYD88 L265P mutation has not yet been investigated in association with the tumour necrosis factor alpha induced protein3 (TNFAIP3) mutation.
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[Expression of TRAF-6,TAK1 and TGF-β mRNA in peripheral blood mononuclear cells of patients with diffuse large B cell lymphoma before and after chemotherapy].
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This study was purposed to detect the expression levels of TRAF6, TAK1 and TGF-β mRNA in peripheral blood mononuclear cell (PBMNC) of patients with diffuse large B cell lymphoma (DLBCL) before and after chemotherapy, and to explore the effect of chemotherapy on the activity of TRAF6/TAK1 signal pathway. The expression levels of TRAF-6, TAK1 and TGF-β mRNA in PBMNC of 38 patients with DLBCL were detected by using the quantitative real time PCR before treatment or after two cycles of chemotherapy, 12 healthy people were served as the control. The results showed that the expression levels of TRAF-6, TAK1 and TGF-β mRNA in PBMNC of DLBCL patients' were higher than those in healthy people. Before treatment, the expression levels of TRAF-6 and TAK1 mRNA had no significant difference as compared with healthy people (P > 0.05); after chemotherapy, the expression levels of these two genes significantly increased, and the differences both had statistically significant as compared with healthy people (P < 0.05); meanwhile the increased expression levels of these two genes after chemotherapy had statistically significant difference as compared with levels before treatment (P < 0.05) , and those expression levels were positively correlated. While the expression level of TGF-β mRNA decreased after chemotherapy as compared with level before treatment, and the differences had statistically significantse(P < 0.05). It is concluded that the activity of TRF6/TAK1 signal pathways in PBMNC of DLBCL patients' significantly increases after chemotherapy, while the expression level of TGF-β mRNA after chemotherapy is abviously lower than level before treatment.
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Our previous studies have demonstrated that tumor-infiltrating lymphocytes (TILs), including normal B cells, T cells, and natural killer (NK) cells, in diffuse large B-cell lymphoma (DLBCL) have a significantly favorable impact on the clinical outcomes of patients treated with standard chemoimmunotherapy. In this study, to gain a full overview of the tumor immune microenvironment (TIME), we assembled a flow cytometry cohort of 102 patients diagnosed with DLBCL at the Duke University Medical Center.
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Epidemiology and Outcome of Nailbed Injuries Managed in Children's Emergency Department: A 10-Year Single-Center Experience.
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Fingertip injuries are among the most common hand injuries in children and result in significant health, time, and a financial burden. Nailbed injuries constitute a large proportion of fingertip injuries and are frequent in children.
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The overall objective of the study was to describe the disposition status of children presenting with a burn injury to five emergency departments (ED) across New South Wales (NSW), Australia.
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Epidemiology and Outcome of Nailbed Injuries Managed in Children's Emergency Department: A 10-Year Single-Center Experience.
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Fingertip injuries are among the most common hand injuries in children and result in significant health, time, and a financial burden. Nailbed injuries constitute a large proportion of fingertip injuries and are frequent in children.
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In this study, the authors have compared data concerning the pediatric triage that is carried out in 2 large emergency departments (EDs) in Rome, one located in a university pediatric clinic with qualified staff and the other one in a general hospital with a high flow of users and pediatric admissions.
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Epidemiology and Outcome of Nailbed Injuries Managed in Children's Emergency Department: A 10-Year Single-Center Experience.
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Fingertip injuries are among the most common hand injuries in children and result in significant health, time, and a financial burden. Nailbed injuries constitute a large proportion of fingertip injuries and are frequent in children.
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The aims of the study were (1) to determine the frequency of neck pain in patients diagnosed with mild traumatic brain injury (mTBI) or concussion in a pediatric level 1 trauma center emergency department (ED), (2) to identify variables associated with neck pain in this population, and (3) to report on aspects of care received in the ED including imaging and medication use.
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Epidemiology and Outcome of Nailbed Injuries Managed in Children's Emergency Department: A 10-Year Single-Center Experience.
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Fingertip injuries are among the most common hand injuries in children and result in significant health, time, and a financial burden. Nailbed injuries constitute a large proportion of fingertip injuries and are frequent in children.
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To describe the prevalence and clinical characteristics of a large cohort of childhood glaucoma patients that presented to a tertiary Egyptian children's hospital using the childhood glaucoma research network (CGRN) classification.
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Epidemiology and Outcome of Nailbed Injuries Managed in Children's Emergency Department: A 10-Year Single-Center Experience.
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Fingertip injuries are among the most common hand injuries in children and result in significant health, time, and a financial burden. Nailbed injuries constitute a large proportion of fingertip injuries and are frequent in children.
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To analyze the etiology, characteristics, and ureteral reconstruction strategies of iatrogenic ureteric injuries in a high-volume center.
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Identifying patients with psychosocial problems in general practice: a scoping review protocol.
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Psychosocial problems (PSPs) are common issues associated with negative health outcomes. Since general practitioners are the first point of contact for any health-related concern, understanding their options to recognise patients with PSPs plays an important role as it is essential for early intervention and can prevent serious conditions. The objective of our scoping review is to map published evidence on the usage of instruments to identify patients with PSPs in general practice.
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This scoping review aims to give a comprehensive and systematic overview of published evaluations and the potential impact of patient education interventions for children, adolescents and young adults who are living with chronic illness and/or impairment loss.
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Identifying patients with psychosocial problems in general practice: a scoping review protocol.
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Psychosocial problems (PSPs) are common issues associated with negative health outcomes. Since general practitioners are the first point of contact for any health-related concern, understanding their options to recognise patients with PSPs plays an important role as it is essential for early intervention and can prevent serious conditions. The objective of our scoping review is to map published evidence on the usage of instruments to identify patients with PSPs in general practice.
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To critically synthesize the literature that describes men's help-seeking and engagement with general practice.
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Identifying patients with psychosocial problems in general practice: a scoping review protocol.
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Psychosocial problems (PSPs) are common issues associated with negative health outcomes. Since general practitioners are the first point of contact for any health-related concern, understanding their options to recognise patients with PSPs plays an important role as it is essential for early intervention and can prevent serious conditions. The objective of our scoping review is to map published evidence on the usage of instruments to identify patients with PSPs in general practice.
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The objective of this scoping review is to describe the current evidence exploring integrated care for people with chronic musculoskeletal disorders.
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Identifying patients with psychosocial problems in general practice: a scoping review protocol.
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Psychosocial problems (PSPs) are common issues associated with negative health outcomes. Since general practitioners are the first point of contact for any health-related concern, understanding their options to recognise patients with PSPs plays an important role as it is essential for early intervention and can prevent serious conditions. The objective of our scoping review is to map published evidence on the usage of instruments to identify patients with PSPs in general practice.
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The objective of this scoping review is to understand the range and types of evidence in relation to the views of general practitioner and other general practice staff on sharing general practice data for research purposes.
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Identifying patients with psychosocial problems in general practice: a scoping review protocol.
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Psychosocial problems (PSPs) are common issues associated with negative health outcomes. Since general practitioners are the first point of contact for any health-related concern, understanding their options to recognise patients with PSPs plays an important role as it is essential for early intervention and can prevent serious conditions. The objective of our scoping review is to map published evidence on the usage of instruments to identify patients with PSPs in general practice.
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The qualitative systematic review is a rapidly developing area of nursing research. In order to present trustworthy, high-quality recommendations, such reviews should be based on a review protocol to minimize bias and enhance transparency and reproducibility. Although there are a number of resources available to guide researchers in developing a quantitative review protocol, very few resources exist for qualitative reviews.
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Impact of coronavirus disease 2019 on food security in early childhood.
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To summarize the impact of the COVID-19 pandemic on food insecurity during early childhood, with a focus on challenges and strategies to improve access to and consumption of nutritious food in early childcare and education settings.
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We aimed to assess the impact of the coronavirus disease 2019 (COVID-19) pandemic on the incidence of intussusception.
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Impact of coronavirus disease 2019 on food security in early childhood.
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To summarize the impact of the COVID-19 pandemic on food insecurity during early childhood, with a focus on challenges and strategies to improve access to and consumption of nutritious food in early childcare and education settings.
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Safe and effective vaccination is considered to be the most critical strategy to fight coronavirus disease 2019 (COVID-19), leading to individual and herd immunity protection. We aimed to systematically review the economic evaluation of COVID-19 vaccination globally.
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Impact of coronavirus disease 2019 on food security in early childhood.
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To summarize the impact of the COVID-19 pandemic on food insecurity during early childhood, with a focus on challenges and strategies to improve access to and consumption of nutritious food in early childcare and education settings.
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In December 2019, a cluster of viral pneumonia cases, later identified as coronavirus disease 2019 (COVID-19), was first reported in Wuhan, China, and then continued to spread to other parts of the world. COVID-19 is thought to be more prevalent in adults than children; therefore, information about COVID-19 burden and characteristics in children is lacking.
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Impact of coronavirus disease 2019 on food security in early childhood.
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To summarize the impact of the COVID-19 pandemic on food insecurity during early childhood, with a focus on challenges and strategies to improve access to and consumption of nutritious food in early childcare and education settings.
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Knowledge about protection conferred by previous Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) infection and/or vaccination against emerging viral variants allows clinicians, epidemiologists, and health authorities to predict and reduce the future Coronavirus Disease 2019 (COVID-19) burden. We investigated the risk and symptoms of SARS-CoV-2 (re)infection and vaccine breakthrough infection during the Delta and Omicron waves, depending on baseline immune status and subsequent vaccinations.
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Impact of coronavirus disease 2019 on food security in early childhood.
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To summarize the impact of the COVID-19 pandemic on food insecurity during early childhood, with a focus on challenges and strategies to improve access to and consumption of nutritious food in early childcare and education settings.
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Coronavirus disease 2019 (COVID-19), now a global pandemic, has spread to a large number of countries around the world. Symptoms of COVID-19 can range from mild to severe, including fever, cough, shortness of breath, and pneumonia. Some cases even remain asymptomatic. Data regarding the epidemiological and clinical features of children with COVID-19 are limited. Symptoms in children are thought to be atypical when compared with adults. As a result, diagnosis in many children is likely to be missed. Children presenting with atypical symptoms, especially those with a history of exposure, should be referred to early screening.
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Lipid diversity in clostridia.
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Studies of the lipidomes of twenty-one species of clostridia have revealed considerable diversity. Even among those species now defined as Clostridium sensu stricto, which are related to Clostridium butyricum, the type species, lipid analysis has shown that a number of distinct clades have characteristic polar lipids. All species of Clostridium sensu stricto have phosphatidylethanolamine, phosphatidylglycerol and cardiolipin which are present as all acyl or alk-1'-enyl acyl (plasmalogen) species. In addition, almost every clade has specialized polar lipids. For example, the group closely related to Clostridium beijerinckii and several other solventogenic species has glycerol acetals of plasmenylethanolamine, which protects the membrane bilayer arrangement when the lipids are highly unsaturated or in the presence of solvents. The group related to Clostridium novyi has aminoacyl-phosphatidylglycerol, which protects these pathogens from cationic antimicrobial peptides (CAMPs) of innate immunity. Clostridium botulinum species, which fall into several groups, align with these clades, and have the same specific lipids. This review will present the current state of knowledge on clostridial lipids.
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Clostridium organisms are of major importance in the development of technologies to produce biofuels and chemicals. They are uniquely capable of utilizing virtually all biomass-derived carbohydrates, as well as waste gases, waste materials, and C1 compounds, and they possess diverse biosynthetic capabilities for producing a broad spectrum of metabolites, including those of C4-C8 chain length. They can also be readily used in synthetic, syntrophic, and other microbial consortia to broaden the biosynthetic repertoire of individual organisms, thus enabling the development of novel biotechnological processes. Engineering Clostridium organisms at the molecular and population level is hampered by genetic engineering, genome engineering, and microbial-population engineering tools. We discuss these challenges, and the promise that derives from their resolution aiming to usher in an era of broader use of Clostridium organisms as biotechnological platforms.
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Lipid diversity in clostridia.
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Studies of the lipidomes of twenty-one species of clostridia have revealed considerable diversity. Even among those species now defined as Clostridium sensu stricto, which are related to Clostridium butyricum, the type species, lipid analysis has shown that a number of distinct clades have characteristic polar lipids. All species of Clostridium sensu stricto have phosphatidylethanolamine, phosphatidylglycerol and cardiolipin which are present as all acyl or alk-1'-enyl acyl (plasmalogen) species. In addition, almost every clade has specialized polar lipids. For example, the group closely related to Clostridium beijerinckii and several other solventogenic species has glycerol acetals of plasmenylethanolamine, which protects the membrane bilayer arrangement when the lipids are highly unsaturated or in the presence of solvents. The group related to Clostridium novyi has aminoacyl-phosphatidylglycerol, which protects these pathogens from cationic antimicrobial peptides (CAMPs) of innate immunity. Clostridium botulinum species, which fall into several groups, align with these clades, and have the same specific lipids. This review will present the current state of knowledge on clostridial lipids.
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Quantitative understanding of clostridial metabolism is of longstanding interest due to the importance of Clostridia as model anaerobes, biotechnology workhorses, and contributors to evolutionary history and ecosystem. Current computational methods such as flux balance analysis-based construction of clostridial metabolism in genome scale provide a fundamental framework for metabolic analysis. However, this method alone is inadequate to characterize cellular metabolic activity. Experiment-driven approaches including isotope tracer-based fluxomics in association with genetic and biochemical methods are needed to gain a more comprehensive understanding. Here we focus on typical examples where these integrated approaches have contributed to the identification of new metabolic pathways and quantification of metabolic fluxes in Clostridia. We also highlight the opportunities and challenges of cutting-edge fluxomics approaches such as machine learning modeling, deuterium tracer approach, and high throughput flux phenotyping in exploring clostridial metabolism with respect to inorganic carbon utilization, redox cofactor interconversion, and other key metabolic features.
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Lipid diversity in clostridia.
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Studies of the lipidomes of twenty-one species of clostridia have revealed considerable diversity. Even among those species now defined as Clostridium sensu stricto, which are related to Clostridium butyricum, the type species, lipid analysis has shown that a number of distinct clades have characteristic polar lipids. All species of Clostridium sensu stricto have phosphatidylethanolamine, phosphatidylglycerol and cardiolipin which are present as all acyl or alk-1'-enyl acyl (plasmalogen) species. In addition, almost every clade has specialized polar lipids. For example, the group closely related to Clostridium beijerinckii and several other solventogenic species has glycerol acetals of plasmenylethanolamine, which protects the membrane bilayer arrangement when the lipids are highly unsaturated or in the presence of solvents. The group related to Clostridium novyi has aminoacyl-phosphatidylglycerol, which protects these pathogens from cationic antimicrobial peptides (CAMPs) of innate immunity. Clostridium botulinum species, which fall into several groups, align with these clades, and have the same specific lipids. This review will present the current state of knowledge on clostridial lipids.
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While a substantial amount of dietary fats escape absorption in the human small intestine and reach the colon, the ability of resident microbiota to utilize these dietary fats for growth has not been investigated in detail. In this study, we used an <i>in vitro</i> multivessel simulator system of the human colon to reveal that the human gut microbiota is able to utilize typically consumed dietary fatty acids to sustain growth. Gut microbiota adapted quickly to a macronutrient switch from a balanced Western diet-type medium to its variant lacking carbohydrates and proteins. We defined specific genera that increased in their abundances on the fats-only medium, including <i>Alistipes</i>, <i>Bilophila</i>, and several genera of the class <i>Gammaproteobacteria</i> In contrast, the abundances of well-known glycan and protein degraders, including <i>Bacteroides</i>, <i>Clostridium</i>, and <i>Roseburia</i> spp., were reduced under such conditions. The predicted prevalences of microbial genes coding for fatty acid degradation enzymes and anaerobic respiratory reductases were significantly increased in the fats-only environment, whereas the abundance of glycan degradation genes was diminished. These changes also resulted in lower microbial production of short-chain fatty acids and antioxidants. Our findings provide justification for the previously observed alterations in gut microbiota observed in human and animal studies of high-fat diets.<b>IMPORTANCE</b> Increased intake of fats in many developed countries has raised awareness of potentially harmful and beneficial effects of high fat consumption on human health. Some dietary fats escape digestion in the small intestine and reach the colon where they can be metabolized by gut microbiota. We show that human gut microbes are able to maintain a complex community when supplied with dietary fatty acids as the only nutrient and carbon sources. Such fatty acid-based growth leads to lower production of short-chain fatty acids and antioxidants by community members, which potentially have negative health consequences on the host.
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Lipid diversity in clostridia.
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Studies of the lipidomes of twenty-one species of clostridia have revealed considerable diversity. Even among those species now defined as Clostridium sensu stricto, which are related to Clostridium butyricum, the type species, lipid analysis has shown that a number of distinct clades have characteristic polar lipids. All species of Clostridium sensu stricto have phosphatidylethanolamine, phosphatidylglycerol and cardiolipin which are present as all acyl or alk-1'-enyl acyl (plasmalogen) species. In addition, almost every clade has specialized polar lipids. For example, the group closely related to Clostridium beijerinckii and several other solventogenic species has glycerol acetals of plasmenylethanolamine, which protects the membrane bilayer arrangement when the lipids are highly unsaturated or in the presence of solvents. The group related to Clostridium novyi has aminoacyl-phosphatidylglycerol, which protects these pathogens from cationic antimicrobial peptides (CAMPs) of innate immunity. Clostridium botulinum species, which fall into several groups, align with these clades, and have the same specific lipids. This review will present the current state of knowledge on clostridial lipids.
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Bacterial taxonomy and phylogeny based on rrs (16S rDNA) sequencing is being vigorously pursued. In fact, it has been stated that novel biological findings are driven by comparison and integration of massive data sets. In spite of a large reservoir of rrs sequencing data of 1,237,963 entries, this analysis invariably needs supplementation with other genes. The need is to divide the genetic variability within a taxa or genus at their rrs phylogenetic boundaries and to discover those fundamental features, which will enable the bacteria to naturally fall within them. Within the large bacterial community, Clostridium represents a large genus of around 110 species of significant biotechnological and medical importance. Certain Clostridium strains produce some of the deadliest toxins, which cause heavy economic losses. We have targeted this genus because of its high genetic diversity, which does not allow accurate typing with the available molecular methods.
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Lipid diversity in clostridia.
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Studies of the lipidomes of twenty-one species of clostridia have revealed considerable diversity. Even among those species now defined as Clostridium sensu stricto, which are related to Clostridium butyricum, the type species, lipid analysis has shown that a number of distinct clades have characteristic polar lipids. All species of Clostridium sensu stricto have phosphatidylethanolamine, phosphatidylglycerol and cardiolipin which are present as all acyl or alk-1'-enyl acyl (plasmalogen) species. In addition, almost every clade has specialized polar lipids. For example, the group closely related to Clostridium beijerinckii and several other solventogenic species has glycerol acetals of plasmenylethanolamine, which protects the membrane bilayer arrangement when the lipids are highly unsaturated or in the presence of solvents. The group related to Clostridium novyi has aminoacyl-phosphatidylglycerol, which protects these pathogens from cationic antimicrobial peptides (CAMPs) of innate immunity. Clostridium botulinum species, which fall into several groups, align with these clades, and have the same specific lipids. This review will present the current state of knowledge on clostridial lipids.
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The solventogenic Clostridia are of interest to the chemical industry because of their natural ability to produce chemicals such as butanol, acetone and ethanol from diverse feedstocks. Their use as whole cell factories presents multiple metabolic engineering targets that could lead to improved sustainability and profitability of Clostridium industrial processes. However, engineering efforts have been held back by the scarcity of genetic and synthetic biology tools. Over the past decade, genetic tools to enable transformation and chromosomal modifications have been developed, but the lack of a broad palette of synthetic biology parts remains one of the last obstacles to the rapid engineered improvement of these species for bioproduction. We have systematically reviewed existing parts that have been used in the modification of solventogenic Clostridia, revealing a narrow range of empirically chosen and nonengineered parts that are in current use. The analysis uncovers elements, such as promoters, transcriptional terminators and ribosome binding sites where increased fundamental knowledge is needed for their reliable use in different applications. Together, the review provides the most comprehensive list of parts used and also presents areas where an improved toolbox is needed for full exploitation of these industrially important bacteria.
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Antiviral Bioactive Compounds of Mushrooms and Their Antiviral Mechanisms: A Review.
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Mushrooms are used in their natural form as a food supplement and food additive. In addition, several bioactive compounds beneficial for human health have been derived from mushrooms. Among them, polysaccharides, carbohydrate-binding protein, peptides, proteins, enzymes, polyphenols, triterpenes, triterpenoids, and several other compounds exert antiviral activity against DNA and RNA viruses. Their antiviral targets were mostly virus entry, viral genome replication, viral proteins, and cellular proteins and influenced immune modulation, which was evaluated through pre-, simultaneous-, co-, and post-treatment in vitro and in vivo studies. In particular, they treated and relieved the viral diseases caused by herpes simplex virus, influenza virus, and human immunodeficiency virus (HIV). Some mushroom compounds that act against HIV, influenza A virus, and hepatitis C virus showed antiviral effects comparable to those of antiviral drugs. Therefore, bioactive compounds from mushrooms could be candidates for treating viral infections.
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Throughout history, mushrooms have occupied an inseparable part of the diet in many countries. Mushrooms are considered a rich source of phytonutrients such as polysaccharides, dietary fibers, and other micronutrients, in addition to various essential amino acids, which are building blocks of vital proteins. In general, mushrooms offer a wide range of health benefits with a large spectrum of pharmacological properties, including antidiabetic, antioxidative, antiviral, antibacterial, osteoprotective, nephroprotective, hepatoprotective, etc. Both wild edible and medicinal mushrooms possess strong therapeutic and biological activities, which are evident from their <i>in vivo</i> and <i>in vitro</i> assays. The multifunctional activities of the mushroom extracts and the targeted potential of each of the compounds in the extracts have a broad range of applications, especially in the healing and repair of various organs and cells in humans. Owing to the presence of the aforementioned properties and rich phytocomposition, mushrooms are being used in the production of nutraceuticals and pharmaceuticals. This review aims to provide a clear insight on the commercially cultivated, wild edible, and medicinal mushrooms with comprehensive information on their phytochemical constituents and properties as part of food and medicine for futuristic exploitation. Future outlook and prospective challenges associated with the cultivation and processing of these medicinal mushrooms as functional foods are also discussed.
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Antiviral Bioactive Compounds of Mushrooms and Their Antiviral Mechanisms: A Review.
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Mushrooms are used in their natural form as a food supplement and food additive. In addition, several bioactive compounds beneficial for human health have been derived from mushrooms. Among them, polysaccharides, carbohydrate-binding protein, peptides, proteins, enzymes, polyphenols, triterpenes, triterpenoids, and several other compounds exert antiviral activity against DNA and RNA viruses. Their antiviral targets were mostly virus entry, viral genome replication, viral proteins, and cellular proteins and influenced immune modulation, which was evaluated through pre-, simultaneous-, co-, and post-treatment in vitro and in vivo studies. In particular, they treated and relieved the viral diseases caused by herpes simplex virus, influenza virus, and human immunodeficiency virus (HIV). Some mushroom compounds that act against HIV, influenza A virus, and hepatitis C virus showed antiviral effects comparable to those of antiviral drugs. Therefore, bioactive compounds from mushrooms could be candidates for treating viral infections.
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The antimicrobial resistance (AMR) has opened a new market for functional foods with antibacterial activities. More than ever before, people are interested in the natural foods that offer a pathogen fighting benefits due to their obvious advantages over management of diseases. Consumers who are health aware are continually using functional foods in their dietary regimens both for their nutritious, associated health benefits values and convenience. Examples include plant-based essential oils, garlic, and mushrooms. Many studies were conducted on mushrooms crude extracts as functional food with antimicrobial properties, yet the bioactive compounds isolated are few or even rare. Because antimicrobial resistance and biofilm formation are exacerbating the severity of infectious diseases worldwide, this review summarized the antimicrobial molecules compared to the number of extracts as well as the biofilm acting compounds and extracts from edible mushrooms in the last seven years to facilitate drawing the roadmap of anti-infectious agent's discovery from functional foods in the future. 156 compounds and more than 100 edible mushroom extracts with antibacterial, antifungal or biofilm inhibiting activities through the period from 2015 to 2022 were reviewed. Pubmed, Web of Science, and Scopus were thoroughly searched with relevant search words, and data reviewed indicated ninety active compounds against Gram (-ve), hundred and twenty active compounds against Gram (+ve), sixty-eight active compounds against fungi. The biofilm inhibition was revealed by nineteen compounds. Effective combinations active in biofilm inhibition were represented by quinic acid with uridine/inosine or adenine/oxalic mixtures. Activities against multi-resistant strains, represented by ESKAPE (Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, and Enterobacter species), MRSA (Methicillin Resistant Staphylococcus aureus), VRSA (Vancomycin Resistant Staphylococcus aureus) and multi-resistant tuberculosis were shown by 39 compounds and extracts. Terpenoid compounds revealed the most potent antimicrobial action; for instance, cyathanes, cerevisterol, psathyrins and grifolaone. Because variation in cultural media is accompanied by a different response in fungal growth and mass yield as well as the variation of compounds of interest from one strain to another, the methods of isolation, cultures and media used are highlighted together with structure activity relationships when available.
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Antiviral Bioactive Compounds of Mushrooms and Their Antiviral Mechanisms: A Review.
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Mushrooms are used in their natural form as a food supplement and food additive. In addition, several bioactive compounds beneficial for human health have been derived from mushrooms. Among them, polysaccharides, carbohydrate-binding protein, peptides, proteins, enzymes, polyphenols, triterpenes, triterpenoids, and several other compounds exert antiviral activity against DNA and RNA viruses. Their antiviral targets were mostly virus entry, viral genome replication, viral proteins, and cellular proteins and influenced immune modulation, which was evaluated through pre-, simultaneous-, co-, and post-treatment in vitro and in vivo studies. In particular, they treated and relieved the viral diseases caused by herpes simplex virus, influenza virus, and human immunodeficiency virus (HIV). Some mushroom compounds that act against HIV, influenza A virus, and hepatitis C virus showed antiviral effects comparable to those of antiviral drugs. Therefore, bioactive compounds from mushrooms could be candidates for treating viral infections.
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Among many sources of natural bioactive substances, mushrooms constitute a huge and almost unexplored group. Fungal compounds have been repeatedly reported to exert biological effects which have prompted their use in pharmaceutical and cosmetic industry. Therefore, the aim of this study was analysis of chemical composition and biological activity of 31 wild growing mushroom species (including saprophytic and parasitic) from Poland.
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Antiviral Bioactive Compounds of Mushrooms and Their Antiviral Mechanisms: A Review.
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Mushrooms are used in their natural form as a food supplement and food additive. In addition, several bioactive compounds beneficial for human health have been derived from mushrooms. Among them, polysaccharides, carbohydrate-binding protein, peptides, proteins, enzymes, polyphenols, triterpenes, triterpenoids, and several other compounds exert antiviral activity against DNA and RNA viruses. Their antiviral targets were mostly virus entry, viral genome replication, viral proteins, and cellular proteins and influenced immune modulation, which was evaluated through pre-, simultaneous-, co-, and post-treatment in vitro and in vivo studies. In particular, they treated and relieved the viral diseases caused by herpes simplex virus, influenza virus, and human immunodeficiency virus (HIV). Some mushroom compounds that act against HIV, influenza A virus, and hepatitis C virus showed antiviral effects comparable to those of antiviral drugs. Therefore, bioactive compounds from mushrooms could be candidates for treating viral infections.
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Venoms of several animals have been used to study various physiopathologic processes, and also to offer opportunity to design and develop new therapeutic drugs. We briefly review certain wasp venom components and their biological effects, which may be potential sources of novel pharmacologically active compounds.
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Antiviral Bioactive Compounds of Mushrooms and Their Antiviral Mechanisms: A Review.
|
Mushrooms are used in their natural form as a food supplement and food additive. In addition, several bioactive compounds beneficial for human health have been derived from mushrooms. Among them, polysaccharides, carbohydrate-binding protein, peptides, proteins, enzymes, polyphenols, triterpenes, triterpenoids, and several other compounds exert antiviral activity against DNA and RNA viruses. Their antiviral targets were mostly virus entry, viral genome replication, viral proteins, and cellular proteins and influenced immune modulation, which was evaluated through pre-, simultaneous-, co-, and post-treatment in vitro and in vivo studies. In particular, they treated and relieved the viral diseases caused by herpes simplex virus, influenza virus, and human immunodeficiency virus (HIV). Some mushroom compounds that act against HIV, influenza A virus, and hepatitis C virus showed antiviral effects comparable to those of antiviral drugs. Therefore, bioactive compounds from mushrooms could be candidates for treating viral infections.
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This review covers the 2003-2012 literature data published for antitumor natural products from marine-derived fungi. The focus is on new and highly potent cytotoxic compounds, together with details related to the relevant fungal species. It describes 22 promising bioactives, originating mainly from symbiotic fungi. The chemical structures of all highlighted organic molecules are briefly discussed.
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Design and application of a novel integrated electrochemical hydride generation cell for the determination of arsenic in seaweeds by atomic fluorescence spectrometry.
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An integrated electrochemical hydride generation cell, mainly composed of three components (a gas liquid separator, a graphite tube cathode and a reticulate Pt wire anode), was laboratory constructed and employed for the detection of arsenic by coupling to atomic fluorescence spectrometry. This integrated cell was free of ion-exchange membrane and individual anolyte, with the virtues of low-cost, easy assembly and environmental-friendly. Using flow injection mode, the sample throughput could come to 120 h(-1) attributed to the small dimension of the cathode chamber. The operating conditions for the electrochemical hydride generation of arsenic were investigated in detail and the potential interferences from oxygen or various ions were also evaluated. Under the optimized conditions, no obvious oxygen quenching effects were observed. The limit of detection of As (III) for the sample blank solution was 0.2 ng mL(-1) (3sigma) and the relative standard deviation was 3.1% for nine consecutive measurements of 5 ng mL(-1) As (III) standard solution. The calibration curve was linear up to 100 ng mL(-1). The accuracy of the method was verified by the determination of arsenic in the reference materials GBW08517 (Laminaria Japonica Aresch) and GBW10023 (Porphyra crispata) and the developed method was successfully applied to determine trace amounts of arsenic in edible seaweeds.
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This paper focuses on the analytical performance improvement of the coupled technique HPLC-ICPMS using on-line collision/reaction cell technology for selenium elemental and speciation analyses at the ng (Se) l(-1) level in aquatic environment. Collision/reaction cell operating parameters were optimised, resulting in selected conditions of 5.5 ml min(-1) H(2) and 0.5 ml min(-1) He mixture. The detection limits obtained were around 5 ng (Se) l(-1) for total analysis, and between 7 and 15 ng (Se) l(-1) depending on the species for speciation analysis. The capability of UV irradiation-hydride generation interfacing to increase detector sensitivity was also evaluated for speciation analysis. The detection limits obtained were in the range 2-8 ng (Se) l(-1) depending on the species. Moreover, such interface allowed to prevent bromine introduction to the ICPMS which is particularly convenient for selenium trace analysis in natural waters as (80)Se is preserved free from BrH interferences. The developed method was validated using certified water with low selenium content (TM Rain 95, NWRI, Canada) and applied to the analysis of different waters.
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