Mutation c.359_363delGTATTinsATAC in the COL4A5 Causes alport syndrome in a Chinese family

The X-linked form of Alport syndrome is associated with mutations in the COL4A5 gene, which is located at Xq22.3 and encodes the α5 chain of type IV collagen. Here we clinically characterized a Chinese family with Alport Syndrome, but no ocular or hearing abnormalities have been observed in any patient in the family. Through Linkage analysis and direct DNA sequencing, a novel complex deletion/insertion mutation c.359_363delGTATTinsATAC in the COL4A5 gene was identified in the family. The mutation was found in all affected family members, but was not present in the unaffected family individuals or the 200 controls. The predicted mutant protein in the family is a truncated protein consisting of only 153 residues. Our report for the first time revealed that the frameshift mutation in the type IV collagen chain α5 causes only renal disease, without extrarenal lesion. Our study broadens genotypic and phenotypic spectrum of COL4A5 mutations associated with Alport syndrome.     

REV3基因对结肠癌细胞遗传信息表达的影响

利用RNA干扰技术降低REV3基因在人类结肠癌细胞(SW480)中的表达, 以荧光实时定量PCR检测REV3表达量的降低情况, 选择低表达效率具有统计学意义的细胞作为实验组细胞。运用细胞生长曲线、MTT、微核和姐妹染色单体交换等方法, 对实验组和对照组细胞进行细胞生长周期、增殖变化情况和遗传信息表达等指标的检测。结果显示: REV3低表达的结肠癌实验组细胞在细胞增殖以及细胞的微核和姐妹染色单体交换等遗传信息表达均明显低于结肠癌对照组细胞, 实验结果具有统计学意义(P＜0.05); 结肠癌的两对照组间(阴性和空白)的结果虽然有一定的差异, 但没有统计学意义。研究结果提示, REV3低表达时, 可能对结肠癌细胞(SW480)的生长与增殖产生影响, 并对微核和姐妹染色单体交换等遗传不稳定现象的产生有一定的抑制作用。     

43 例HIV/AIDS 患者抗病毒治疗情况分析

目的:研究来第四军医大学唐都医院传染科就诊的人类免疫缺陷病毒/艾滋病(Human immunodeficiency virus/Acquired immuno deficiency syndrome,HIV/AIDS)患者感染状况及抗病毒治疗效果。方法:采用前瞻性随访研究的方法,收集来我院就诊的HIV/AIDS患者的基本信息,并对其实验室检查结果、治疗方案及后续随访结果进行分析。结果:随访观察的43例HIV/AIDS患者治疗前平均基线CD4+T淋巴细胞计数为(330.74±176.35)cells/μL,CD8+T淋巴细胞计数为(1177.80±321.49)cells/μL,CD4+,CD8+T淋巴细胞比值为0.30±0.19;治疗一年后平均CD4+T淋巴细胞计数为(482.74±217.77)cells/μL,CD8+T淋巴细胞计数为(861.53±282.85)cells/μL,CD4+,CD8+T淋巴细胞比值为0.59±0.28。所有患者治疗一年后血浆HIV-RNA载量均达到检测限以下(500copies/m L)。结论:规范的抗病毒治疗对于改善HIV/AIDS患者预后至关重要;基线CD4+T淋巴细胞计数越低,抗病毒治疗效果越差。     

Determination of the chromosomal site for the human radiosensitive ataxia telangiectasia gene by chromosome transfer

The chromosomal localization of the gene which complements radiation hypersensitivity of AT cells was studied by microcell-mediated chromosome transfer. A 6-thioguanine-resistant derivative of an immortalized AT cell line, AT2KYSVTG, was used as a recipient for microcell-mediated chromosome transfer from 4 strains of mouse A9 cells, 3 of which carried a human X/11 recombinant chromosome containing various regions of chromosome 11, while the other carried an intact X chromosome. HAT-resistant microcell hybrids were isolated and examined for their radiosensitivity and chromosome constitution. The microcell hybrid clones obtained from the transfer of an intact X chromosome or an X/11 chromosome bearing the pter → q13 region of chromosome 11 did not show a difference in radiosensitivity from parental AT cells, while those obtained from the transfer of X/11 chromosomes bearing either the p11 → qter or the pter → q23 region of chromosome 11 exhibited a marked radioresistance which was comparable to normal human fibroblasts. A HAT-resistant but radiosensitive variant was further obtained from the microcell fusion with an A9 cell strain carrying an X/11 chromosome bearing the 11p11 → qter region, in which a deletion at the 11q23 region was found. The results indicate that the gene which complements a radiosensitive phenotype of AT is located at the q23 region of chromosome 11.     

Development and validation of a bioreactor system for dynamic loading and mechanical characterization of whole human intervertebral discs in organ culture

Intervertebral disc (IVD) degeneration is a common cause of back pain, and attempts to develop therapies are frustrated by lack of model systems that mimic the human condition. Human IVD organ culture models can address this gap, yet current models are limited since vertebral endplates are removed to maintain cell viability, physiological loading is not applied, and mechanical behaviors are not measured. This study aimed to (i) establish a method for isolating human IVDs from autopsy with intact vertebral endplates, and (ii) develop and validate an organ culture loading system for human or bovine IVDs. Human IVDs with intact endplates were isolated from cadavers within 48 h of death and cultured for up to 21 days. IVDs remained viable with ~80% cell viability in nucleus and annulus regions. A dynamic loading system was designed and built with the capacity to culture 9 bovine or 6 human IVDs simultaneously while applying simulated physiologic loads (maximum force: 4 kN) and measuring IVD mechanical behaviors. The loading system accurately applied dynamic loading regimes (RMS error <2.5 N and total harmonic distortion <2.45%), and precisely evaluated mechanical behavior of rubber and bovine IVDs. Bovine IVDs maintained their mechanical behavior and retained >85% viable cells throughout the 3 week culture period. This organ culture loading system can closely mimic physiological conditions and be used to investigate response of living human and bovine IVDs to mechanical and chemical challenges and to screen therapeutic repair techniques.     

人类免疫缺陷病毒潜伏库定量检测技术的研究进展

以静息CD4~+T细胞为主的人类免疫缺陷病毒(human immunodeficiency virus,HIV)潜伏库的清除已成为治愈HIV-1感染的主要障碍,人们迫切需要建立一种高通量、可靠的、高灵敏度的方法来定量检测病毒潜伏库的真实大小。本文就目前关于HIV潜伏库的多种定量检测方法进行综述。     

The effects of guanine and cytosine variation on dinucleotide frequency and amino acid composition in the human genome

Summary One hundred twelve human DNA sequences were analyzed with respect to dinucleotide frequency and amino acid composition. The variation in guanine and cytosine (G+C) content revealed: (1) at 2–3 and 3-1 doublet positions CG discrimination is attenuated at high G+C, but TA disfavor is enhanced, and (2) several amino acids are subject to G+C change. These findings have been reported in part for collections of sequences from various species. The present study confirms that in a single organism-the human-the G+C effects do exist. Aspects of the argument that connects G+C with protein thermal stability are also discussed.     

Conservation of human Y chromosome sequences among male great apes: Implications for the evolution of Y chromosomes

Nine newly described single-copy and lowcopy-number genomic DNA sequences isolated from a flow-sorted human Y chromosome library were mapped to regions of the human Y chromosome and were hybridized to Southern blots of male and female great ape genomic DNAs (Gorilla gorilla, Pan troglodytes, Pongo pygmaeus). Eight of the nine sequences mapped to the euchromatic Y long arm (Yq) in humans, and the ninth mapped to the short arm or pericentromeric region. All nine of the newly identified sequences and two additional human Yq sequences hybridized to restriction fragments in male but not female genomic DNA from the great apes, indicating Y chromosome localization. Seven of these 11 human Yq sequences hybridized to similarly-sized restriction endonuclease fragments in all the great ape species analyzed. The five human sequences that mapped to the most distal subregion of Yq (deletion of which region is associated with spermatogenic failure in humans) were hybridized to Southern blots generated by pulsed-field gel electrophoresis. These sequences define a region of approximately 1 Mb on human Yq in which HpaII tiny fragment (HTF) islands appear to be absent. The conservation of these human Yq sequences on great ape Y chromosomes indicates a greater stability in this region of the Y than has been previously described for most anonymous human Y chromosomal sequences. The stability of these sequences on great ape Y chromosomes seems remarkable given that this region of the Y does not undergo meiotic recombination and the sequences do not appear to encode genes for which positive selection might occur. Correspondence to: B. Steele Allen     

甲基毒死蜱对红细胞膜乙酰胆碱酯酶的抑制作用及其与膜脂相互关系

以人红细胞膜为材料,研究了甲基毒死蜱与膜上乙酰胆碱酯酶(AChE)的相互作用及其与膜脂的关系。结果显示,甲基毒死蜱对人红细胞膜AChE有明显的抑制作用,与膜温育30min,其半数抑制浓度约为0.10 mmol/L。动力学分析表明,其抑制作用为非竞争性。0.2％Triton X-100并不改变AChE对甲基毒死蜱的敏感性,亦即AChE上甲基毒死蜱的作用部位与其所处的脂质微环境无关。     

马铃薯甲虫结节性硬化复合物基因LdTSC1和LdTSC2基因的克隆及功能分析

【目的】通过RNAi技术明确马铃薯甲虫TOR上游的关键信号集成节点及类胰岛素信号通道下游基因结节性硬化复合物TSC1和TSC2的功能。旨在为探明马铃薯甲虫类胰岛素信号转导提供更多理论支持。【方法】在NCBI(美国国家生物技术信息中心)获取马铃薯甲虫LdTSC1/2序列,分别利用多重序列比对和系统发育分析确定该基因的完整性和系统发育关系;采用喂食幼虫dsRNA的方法,观察该基因的调低对马铃薯甲虫幼虫生长发育、糖脂代谢的影响。【结果】克隆得到马铃薯甲虫TSC1编码蛋白的氨基酸序列与鞘翅目白蜡窄吉丁直系同源蛋白的氨基酸序列的自展一致度为100%,聚为一支;TSC2编码蛋白的氨基酸序列与鞘翅目白蜡窄吉丁和赤拟谷盗的同源蛋白氨基酸序列的自展一致度为100%,聚为一支。通过分别喂食2龄幼虫LdTSC1/2的dsRNA能有效降低靶标基因的表达量,幼虫出现体重减轻,化蛹率和羽化率显著下降,葡萄糖的吸收转化效率降低,海藻糖含量升高和甘油三酯均减少。【结论】下调2龄幼虫LdTSC1/2的表达量,导致试虫出现抑制了糖脂代谢、脂肪体减少、体重减轻以及发育延迟;结果表明LdTSC1/2调控了马铃薯甲虫幼虫的糖脂代谢过程,显著影响幼虫化蛹和蜕皮过程。