Population structure of Y chromosome SNP haplogroups in the United States and forensic implications for constructing Y chromosome STR databases

A set of 61 Y chromosome single-nucleotide-polymorphisms (Y-SNPs) is typed in a sample of 2517 individuals from 38 populations to infer the geographic origins of Y chromosomes in the United States and to test for paternal admixture among African-, European-, Hispanic-, Asian-, and Native-Americans. All of the samples were previously typed with the 11 core U.S. Y chromosome short tandem repeats (Y-STRs) recommended by SWGDAM, which revealed high levels of among ethnic group variation and low levels of among-population-within-ethnic-group variation. Admixture estimates vary greatly among populations and ethnic groups. The frequencies of non-European (3.4%) and non-Asian (4.5%) Y chromosomes are generally low in European-American and Asian-American populations, respectively. The frequencies of European Y chromosomes in Native-American populations range widely (i.e., 7-89%) and follow a West to East gradient, whereas they are relatively consistent in African-American populations (26.4+/-8.9%) from different locations. The European (77.8+/-9.3%) and Native-American (13.7+/-7.4%) components of the Hispanic paternal gene pool are also relatively constant among geographic regions; however, the African contribution is much higher in the Northeast (10.5+/-6.4%) than in the Southwest (1.5+/-0.9%) or Midwest (0%). To test for the effects of inter-ethnic admixture on the structure of Y-STR diversity in the U.S., we perform subtraction analyses in which Y chromosomes inferred to be admixed by Y-SNP analysis are removed from the database and pairwise population differentiation tests are implemented on the remaining Y-STR haplotypes. Results show that low levels of heterogeneity previously observed between pairs of Hispanic-American populations disappear when African-derived chromosomes are removed from the analysis. This is not the case for an unusual sample of European-Americans from New York City when its African-derived chromosomes are removed, or for Native-American populations when European-derived chromosomes are removed. We infer that both inter-ethnic admixture and population structure in ancestral source populations may contribute to fine scale Y-STR heterogeneity within U.S. ethnic groups.     

毛发中GHB的检测及评价

目的探索毛发中外源性GHB的检测及判断的可行性,为涉GHB的鉴定提供方法和依据。方法建立毛发中GHB的GC/MS分析方法,并通过动物实验,考察毛发中内源性GHB的质量分数范围、外源性GHB在毛发中的时间过程以及给药剂量、毛发颜色与毛发中GHB的质量分数关系。结果豚鼠和中国人黑色毛发中内源性GHB质量分数分别为(3.01±1.41)ng/mg(n=28)和(1.02±0.27)ng/mg(n=20);摄GHB后毛发中GHB质量分数明显增加且与给药剂量呈正相关性;GHB在毛干中呈窄带分布;深色毛发中GHB质量分数高于浅色毛发。结论毛发中GHB的检测适用于GHB滥用和中毒的法医毒物学鉴定;根据毛发中的GHB质量分数和毛发分段分析可判断GHB的来源。     

交通事故致胸、腰椎损伤致残等级评定447例分析

目的探讨车祸致胸、腰椎损伤程度与伤残程度的关系,总结伤残评定经验,探寻其规律性。方法选择胸、腰椎损伤的鉴定447例,重新审查诊断,分析治疗措施,评价胸腰部活动度丧失程度及神经功能障碍情况,分析损伤程度与后遗障碍之间的关系,综合评定伤残。结果胸、腰椎损伤类型及数量并不决定其胸、腰部活动障碍程度及神经损伤后遗症严重程度;椎体损伤的部位与胸腰部活动度障碍关系密切;神经损伤主要集中在T1至L2段脊柱损伤;椎体损伤医院误诊率较高。结论伤残评定应分析损伤与后遗症严重程度的因果关系,以损伤所致后遗症为评残依据,重点关注脊柱功能的丧失程度。     

大鼠死后腓肠肌直接电兴奋性变化与早期死亡时间的关系

目的探讨大鼠死亡后不同时间腓肠肌电兴奋性的变化,为早期死亡时间的推断提供新的指标。方法建立大鼠机械性窒息模型,利用电生理检测仪检测死亡后不同时间大鼠腓肠肌对不同强度的电刺激的反应性,记录肌肉组织动作电位出现时间,统计学分析其差异并建立回归方程。结果大鼠机械性窒息死亡后一定时间内,其腓肠肌对电刺激的兴奋性与死亡时间呈明显线性关系。结论肌肉组织的电兴奋性可以作为早期死亡时间推断的有效指标。     

婴幼儿猝死综合征神经病理学的研究进展

婴幼儿猝死综合征(SIDS)是指发生于1岁以内婴儿无明显病因的突然死亡,其死亡原因及鉴别诊断标准迄今仍不明确。本文参考了近年来采用免疫组化方法对SIDS神经系统病理变化的研究文献,提出SIDS致命的病理生理机制是与睡眠相关的呼吸循环失控或衰竭,即SIDS的主要病因存在于中枢神经系统,但不是单一病因。     

大鼠急性心肌缺血动物实验模型的改进

目的改进大鼠急性心肌缺血动物实验模型时,提高手术的成功率和动物成活率。方法比较传统方法与改进方法动物试验的成功率。结果传统方法成功率只有60%,改进方法成功率达到90%以上。结论改进后的方法能大大降低手术难度,减少实验费用,优于传统方法。     

Fatal accidental intrathecal injection of vindesine

ABSTRACT: A 25-year-old woman being treated for non-Hodgkin's lymphoma was accidentally given vindesine intrathecally. The error was recognized immediately and a spinal cord washing was performed through syringing with isotonic saline. However, the patient died 6 weeks later with increasing paralysis, which was followed by neurologic failure. The deceased was autopsied and the central nervous system was removed for a microscopic examination. The results showed microscopic lesions extending from the lumbar to the thoracic portion of the spinal cord, which included pseudocystic transformation of the cells, degeneration of myelin, and microhemorrhages. The brain was edematous and, in the cerebellum, the vermis showed a loss of granule and Purkinje cells. The authors compare this report on vindesine toxicity with cases in the literature involving vincristine. The treating physician admitted responsibility and was sentenced to both a fine and imprisonment.     

Analysis of the population heterogeneity in Hungary using fifteen forensically informative STR markers

Previous studies have shown that population analyses in Hungary can be of great importance from the viewpoint of the examination of population differentiation. This study provides additional population genetic data of the Hungarian population on the thirteen CODIS core STR loci and on two penta STRs (PentaE, PentaD). Allele frequency and profile databases were generated for four population samples. Comparing the allele frequency values by G-statistic, calculating the FST indices and with the pair-wise comparisons of inter-population molecular variance (AMOVA) the four Hungarian populations could be distinguished.