4,724 research outputs found
Comparative analysis of Mycobacterium tuberculosis pe and ppe genes reveals high sequence variation and an apparent absence of selective constraints.
No full textContains fulltext :
110619.pdf (Publisher’s version ) (Open Access)Mycobacterium tuberculosis complex (MTBC) genomes contain 2 large gene families termed pe and ppe. The function of pe/ppe proteins remains enigmatic but studies suggest that they are secreted or cell surface associated and are involved in bacterial virulence. Previous studies have also shown that some pe/ppe genes are polymorphic, a finding that suggests involvement in antigenic variation. Using comparative sequence analysis of 18 publicly available MTBC whole genome sequences, we have performed alignments of 33 pe (excluding pe_pgrs) and 66 ppe genes in order to detect the frequency and nature of genetic variation. This work has been supplemented by whole gene sequencing of 14 pe/ppe (including 5 pe_pgrs) genes in a cohort of 40 diverse and well defined clinical isolates covering all the main lineages of the M. tuberculosis phylogenetic tree. We show that nsSNP's in pe (excluding pgrs) and ppe genes are 3.0 and 3.3 times higher than in non-pe/ppe genes respectively and that numerous other mutation types are also present at a high frequency. It has previously been shown that non-pe/ppe M. tuberculosis genes display a remarkably low level of purifying selection. Here, we also show that compared to these genes those of the pe/ppe families show a further reduction of selection pressure that suggests neutral evolution. This is inconsistent with the positive selection pressure of "classical" antigenic variation. Finally, by analyzing such a large number of genes we were able to detect large differences in mutation type and frequency between both individual genes and gene sub-families. The high variation rates and absence of selective constraints provides valuable insights into potential pe/ppe function. Since pe/ppe proteins are highly antigenic and have been studied as potential vaccine components these results should also prove informative for aspects of M. tuberculosis vaccine design
On minimal non-PE-groups
No full textAbstractIf H is a subgroup of a finite group G, by HG denote the normal closure of H in G. G is called a PE-group if every minimal subgroup X of G satisfies NG(X) ∩ XG = X. The author proves that all PE-groups are solvable with the Fitting height at most 3 and classifies the minimal non-PE-groups
Sex differences in the association between plasma copeptin and incident type 2 diabetes: the Prevention of Renal and Vascular Endstage Disease (PREVEND) study
No full textAIMS/HYPOTHESIS: Vasopressin plays a role in osmoregulation, glucose homeostasis and inflammation. Therefore, plasma copeptin, the stable C-terminal portion of the precursor of vasopressin, has strong potential as a biomarker for the cardiometabolic syndrome and diabetes. Previous results were contradictory, which may be explained by differences between men and women in responsiveness of the vasopressin system. The aim of this study was to evaluate the usefulness of copeptin for prediction of future type 2 diabetes in men and women separately. METHODS: From the Prevention of Renal and Vascular Endstage Disease (PREVEND) study, 4,063 women and 3,909 men without diabetes at baseline were included. A total of 208 women and 288 men developed diabetes during a median follow-up of 7.7 years. RESULTS: In multivariable-adjusted models, we observed a stronger association of copeptin with risk of future diabetes in women (OR 1.49 [95% CI 1.24, 1.79]) than in men (OR 1.01 [95% CI 0.85, 1.19]) (p (interaction) < 0.01). The addition of copeptin to the Data from the Epidemiological Study on the Insulin Resistance Syndrome (DESIR) clinical model improved the discriminative value (C-statistic,+0.007, p = 0.02) and reclassification (integrated discrimination improvement [IDI] = 0.004, p < 0.01) in women. However, we observed no improvement in men. The additive value of copeptin in women was maintained when other independent predictors, such as glucose, high sensitivity C-reactive protein (hs-CRP) and 24 h urinary albumin excretion (UAE), were included in the model. CONCLUSIONS/INTERPRETATION: The association of plasma copeptin with the risk of developing diabetes was stronger in women than in men. Plasma copeptin alone, and along with existing biomarkers (glucose, hs-CRP and UAE), significantly improved the risk prediction for diabetes in women
[[alternative]]The Study of Acknowledgement of Risk Management on Perception of PE Teachers in Taoyuan Junior High Schools
No full text[[abstract]]The purpose of this study was to (1) explore the acknowledgement about physical activity risk management of junior high school PE teachers in Taoyuan, (2) compare PE teachers’ perception difference about risk management with different background (3) realize the strategy of risk management plan of PE teachers in junior high school. (4) finally build effective risk management plan for all PE teachers in junior high school.
One hundred and ninety two Taoyuan PE teachers served as the subjects of this study with the questionnaire of ” PE Teacher’s Perception of The Risk Management”. This study used descriptive statistics, t-test, and one-way ANOVA to analyze data. Besides, the research also chose seven PE teachers to do semi-structured interview, trying to understand risk management strategy of PE teachers. The results were listed as below:
1.The perception of risk management of physical teachers in junior high school, based on the importance, was: theory layer, practical layer, law layer, entity and application layer.
2.Significant difference was found in gender, practical layer, law layer and entity; while other factors showed no significant difference.
3.All the interviewees didn’t take action about risk management , but all of them agreed that risk management plan of physical activity is necessary. They suggested higher authorities ask junior high school to set risk management plan for physical activity, and become an evaluated item.
In conclusion of the research, the PE teachers in junior high school think it is important to execute a better physical activity risk management. Author suggested junior high school should set risk management plan for physical activity to get “zero risk” in school.
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