Identification of hub biomarkers and immune cell infiltration characteristics of polymyositis by bioinformatics analysis.

Background: Polymyositis (PM) is an acquirable muscle disease with proximal muscle involvement of the extremities as the main manifestation; it is a category of idiopathic inflammatory myopathy. This study aimed to identify the key biomarkers of PM, while elucidating PM-associated immune cell infiltration and immune-related pathways. Methods: The gene microarray data related to PM were downloaded from the Gene Expression Omnibus database. The analyses using Gene Ontology (GO), Kyoto Encyclopedia of Genes and Genomes, gene set enrichment analysis (GSEA), and protein-protein interaction (PPI) networks were performed on differentially expressed genes (DEGs). The hub genes of PM were identified using weighted gene co-expression network analysis (WGCNA) and least absolute shrinkage and selection operator (LASSO) algorithm, and the diagnostic accuracy of hub markers for PM was assessed using the receiver operating characteristic curve. In addition, the level of infiltration of 28 immune cells in PM and their interrelationship with hub genes were analyzed using single-sample GSEA. Results: A total of 420 DEGs were identified. The biological functions and signaling pathways closely associated with PM were inflammatory and immune processes. A series of four expression modules were obtained by WGCNA analysis, with the turquoise module having the highest correlation with PM; 196 crossover genes were obtained by combining DEGs. Subsequently, six hub genes were finally identified as the potential biomarkers of PM using LASSO algorithm and validation set verification analysis. In the immune cell infiltration analysis, the infiltration of T lymphocytes and subpopulations, dendritic cells, macrophages, and natural killer cells was more significant in the PM. Conclusion: We identified the hub genes closely related to PM using WGCNA combined with LASSO algorithm, which helped clarify the molecular mechanism of PM development and might have great significance for finding new immunotherapeutic targets, and disease prevention and treatment.

Study on the correlation between hypertension and the indexes of vascular endothelial function among people living in the community / 中华流行病学杂志

<p><b>OBJECTIVE</b>To study the features of hypertension and vessel endothelium functional parameter in people living at the community level as well as the risk factors of hypertension. Differences of angiotensin II (Ang II ), prostacyclin (PGI2) and nitric oxide (NO) among normal group and three hypertension groups were also studied.</p><p><b>METHODS</b>By cluster sampling, 1134 adult Han people were selected from the residential communities. Medical history was documented and measurements of body height, body weight, waist circumference, hip circumference and blood pressure were performed. Serum NO levels were determined by cadmium reduction method while plasma Ang II and PGI2 concentration were determined by radioimmunoassay. SPSS 13.0 was used for data analysis.</p><p><b>RESULTS</b>The total ratio of hypertension from people living at the community was 44.5%, with the standardized prevalence of hypertension as 15.3%. With the increase of age, the prevalence of hypertension also increased. Overweight and obesity seemed to be independent risk factors for hypertension. History of smoking and drinking and gender did not enter the logistic equation for hypertension. The amount of plasma Ang II concentration of the three hypertension groups was significantly lower than that in the normal group while the lowest group appeared to from the one that hypertension was under control. The NO and PGI2 levels of the two groups whose hypertension had been known were significantly higher than in the normal group while the difference between the group whose hypertension had not been measured and the normal group was not found.</p><p><b>CONCLUSION</b>The prevalence of hypertension had been increasing. Control of body weight seemed to be a useful way for prevention of hypertension. We assumed that the negative feedback regulation of renin-angiotonin-aldosterone system in hypertension patient still existed which called for the research on the mechanism of hypertension.</p>

The analysis of plasma homocysteine among 1020 residents in community / 中华流行病学杂志

<p><b>OBJECTIVE</b>To study the plasma homocysteine (Hcy) distributive characteristics in different sex and age groups of the community residents in Guangdong, and to analyze its associated factors as well as its effects on cerebral artery stenosis.</p><p><b>METHODS</b>In this study, we presented data concerning 2500 residents who had undergone a systematic health checkup,including clinical and biologic examinations. Plasma was saved from 1020 residents who were asymptomatic but having TCD examination. Hcy concentration was measured by fluorescence ration biochemical assay kit.</p><p><b>RESULTS</b>The average plasma Hcy levels of males (15.0 micromol/L+/-5.8 micromol/L) were significantly higher than those of females (12.4 micromol/L-I 3.9 micromol/L, P< 0.05). Hcy level increased parallel with age. The prevalence rate of hyperhomocysteinemia in males (47.2%) was higher than in females (23.2%). Hcy levels in MCA stenosis group (18.3 micromol/L+ 5.3 micromol/L) were significantly higher than that in control group (12.9 micromol/L+/- 4.6 micromol/L, P< 0.05). Based on logistic regression analysis, Hcy was only associated with sex and age, but not with blood lipids etc.</p><p><b>CONCLUSION</b>Hcy levels were different in sex and age groups which emerged as independent predictors of hyperhomocysteinemia but had no association with blood lipids in the community residents, suggesting that hyperhomocysteinemia might worsen cerebral artery stenosis.</p>