中国人群维生素D受体rs7975232和rs1544410位点基因多态性与骨质疏松症相关性的meta分析

目的本研究采用meta分析的方法,探讨了中国人维生素D受体基因多态性与骨质疏松的关系。 方法检索CNKI、万方、维普、Pubmed、Web of Science、Embase数据库,检索时间从建库至2020年3月,从数据库中检索有关维生素D受体（rs7975232和rs1544410）基因多态性和骨质疏松症之间相关性的文章。采用NOS文献质量评价标准对符合纳入排除标准的文献进行质量评价。采用OR值及其95%可信区间（95% CI）评估关联强度。根据是否存在异质性,采用固定效应模型或随机效应模型合并效应量。采用单因素敏感性分析法进行敏感性分析。 结果本研究最终共纳入20项符合条件的研究,包括4 468例病例和4 988名对照。在等位基因模型中,rs7975232和rs1544410的合并OR估计值分别为1.09（95% CI：0.84,1.39,P=0.524）和0.9（95% CI：0.57,1.43,P=0.659）,尚未发现两个位点与骨质疏松症的关联。在显性模型、隐性模型和共显性模型中,结果均未显示二者的相关性。 结论在中国人群中,维生素D受体（rs7975232和rs1544410）基因多态性与骨质疏松风险之间无关联。     

乳磨牙龋非创伤性修复技术的临床应用分析

目的分析非创伤性的修复技术/ART技术在乳磨牙龋治疗中的效果。方法选取乳磨牙龋患儿150例,研究组(75例)采用ART技术治疗,对照组(75例)用传统方式治疗;对比两组修复后效果。结果研究组修复总有效率92.0%,对照组为78.7%;研究组综合效果更优(P<0.05)。结论 ART技术在乳磨牙龋治疗中修复效果理想,值得推广。     

TMPRSS2-ERG Fusions Are Strongly Linked to Young Patient Age in Low-grade Prostate Cancer

Based on next-generation sequencing of early-onset prostate cancer (PCa), we earlier demonstrated that PCa in young patients is prone to rearrangements involving androgen-regulated genes—such as transmembrane protease, serine 2 (TMPRSS2)–v-ets avian erythroblastosis virus E26 oncogene homolog (ERG) fusion—and provided data suggesting that this situation might be caused by increased androgen signaling in younger men. In the same study, an accumulation of chromosomal deletions was found in cancers of elderly patients. To determine how age-dependent molecular features relate to cancer phenotype, an existing data set of 11 152 PCas was expanded by additional fluorescence in situ hybridization analyses of phosphatase and tensin homolog (PTEN), 6q15 and 5q21. The results demonstrate that the decrease in TMPRSS2–ERG fusions with increasing patient age is limited to low-grade cancers (Gleason ≤3 + 4) and that the significant increase in the deletion frequency with age was strictly limited to ERG-negative cancers for 6q15 and 5q21 but to ERG-positive cancers for PTEN. These data suggest that the accumulation of non–androgen-linked genomic alterations with advanced patient age may require an appropriate microenvironment, such as a positive or negative ERG status. The strong link of ERG activation to young patient age and low-grade cancers may help to explain a slight predominance of low-grade cancers in young patients.     

Monomethylarsonous acid inhibited endogenous cholesterol biosynthesis in human skin fibroblasts

Human exposure to arsenic in drinking water is a widespread public health concern, and such exposure is known to be associated with many human diseases. The detailed molecular mechanisms about how arsenic species contribute to the adverse human health effects, however, remain incompletely understood. Monomethylarsonous acid [MMA(III)] is a highly toxic and stable metabolite of inorganic arsenic. To exploit the mechanisms through which MMA(III) exerts its cytotoxic effect, we adopted a quantitative proteomic approach, by coupling stable isotope labeling by amino acids in cell culture (SILAC) with LC-MS/MS analysis, to examine the variation in the entire proteome of GM00637 human skin fibroblasts following acute MMA(III) exposure. Among the ~ 6500 unique proteins quantified, ~ 300 displayed significant changes in expression after exposure with 2 μM MMA(III) for 24 h. Subsequent analysis revealed the perturbation of de novo cholesterol biosynthesis, selenoprotein synthesis and Nrf2 pathways evoked by MMA(III) exposure. Particularly, MMA(III) treatment resulted in considerable down-regulation of several enzymes involved in cholesterol biosynthesis. In addition, real-time PCR analysis showed reduced mRNA levels of select genes in this pathway. Furthermore, MMA(III) exposure contributed to a distinct decline in cellular cholesterol content and significant growth inhibition of multiple cell lines, both of which could be restored by supplementation of cholesterol to the culture media. Collectively, the present study demonstrated that the cytotoxicity of MMA(III) may arise, at least in part, from the down-regulation of cholesterol biosynthesis enzymes and the resultant decrease of cellular cholesterol content.     

Gene therapy and DNA delivery systems

Gene therapy is a promising new technique for treating many serious incurable diseases, such as cancer and genetic disorders. The main problem limiting the application of this strategy in vivo is the difficulty of transporting large, fragile and negatively charged molecules like DNA into the nucleus of the cell without degradation. The key to success of gene therapy is to create safe and efficient gene delivery vehicles. Ideally, the vehicle must be able to remain in the bloodstream for a long time and avoid uptake by the mononuclear phagocyte system, in order to ensure its arrival at the desired targets. Moreover, this carrier must also be able to transport the DNA efficiently into the cell cytoplasm, avoiding lysosomal degradation. Viral vehicles are the most commonly used carriers for delivering DNA and have long been used for their high efficiency. However, these vehicles can trigger dangerous immunological responses. Scientists need to find safer and cheaper alternatives. Consequently, the non-viral carriers are being prepared and developed until techniques for encapsulating DNA can be found. This review highlights gene therapy as a new promising technique used to treat many incurable diseases and the different strategies used to transfer DNA, taking into account that introducing DNA into the cell nucleus without degradation is essential for the success of this therapeutic technique.     

Interactions between polymorphisms in the aryl hydrocarbon receptor signalling pathway and exposure to persistent organochlorine pollutants affect human semen quality

Persistent organic pollutants (POPs) may affect male reproductive function. Many dioxin-like POPs exert their effects by activation of the aryl hydrocarbon receptor (AHR) signalling pathway. We analysed whether gene–environment interactions between polymorphisms in AHR (R554K) and AHR repressor (AHRR P185A) and serum levels of markers of POP exposure 1,1-bis-(4-chlorophenyl)-2,2-dichloroethene (p,p′-DDE) and 2,2′,4,4′,5,5′-hexachlorobiphenyl (CB-153) are associated with 21 parameters of male reproductive function in 581 proven-fertile European and Greenlandic men. In Greenlandic men, AHR variants significantly modified the association between serum levels of both p,p′-DDE and CB-153 and inhibin B levels, sperm chromatin integrity, and seminal zinc levels. In the total cohort, interactions between AHRR variants and serum levels of CB-153 were associated with sperm chromatin integrity and the expression of the pro-apoptotic marker protein Fas. The data indicate that susceptibility to adverse effects of POP exposure on male reproductive function is dependent on polymorphisms in genes involved in AHR signalling.