V3 sequence analysis and biological characterization of HIV-1 isolates from asymptomatic and early symptomatic Tanzanian individuals

The aim of this study was to determine HIV-1 V3 sequences, in vitro biological characteristics and co-receptor usage of virus isolates from Tanzania. Virus was isolated from 14 of 17 samples investigated. Four of the isolates induced syncytia in MT-2 cells and used the CXCR4 co-receptor, while the remaining 10 isolates used the CCR5 co-receptor characteristic of non-MT-2 tropic viruses. One of the four MT-2 tropic isolates also used the CCR5 and CCR3 co-receptors. Proviral DNA was detected in all 14 isolates and PCR products were subjected to DNA sequencing. Unambiguous V3 amino acid sequences were obtained from 11 amplificates. Phylogenetic analysis indicated that these sequences were divergent and clustered in HIV-1 subtypes A, C or D. Sequences from the viruses that induced syncytia in MT-2 cells presented characteristic V3 phenotype-associated amino acids. Results of co-receptor analysis are in concordance with the isolate phenotype as determined by replication and induction of syncytia in MT-2 cells. The considerable diversity illustrated by a limited number of isolates from Tanzania is in accordance with reports from other regions of Africa.     

Diversity of Hepatitis G Virus within a Single Infected Individual

The extent of population diversity among GB virus C (GBV-C)/hepatitis G virus (HGV) within a persistently infected individual (Iw) was investigated by sequence analysis of multiple clones generated from polymerase chain reaction (PCR)-amplified products of cDNA analogous to fragments of 5 non-coding region (5NC), envelope region 1/2 (E1/E2) and non-structural region 3 (NS3) of viral genome. Although nucleotide substitutions were more common in coding regions than in the 5NC region, there was no region corresponding to the hypervariable region of hepatitis C virus in the E1/E2 region. Transition substitution exceeded transversion by 7 to 12-fold, and 79.4% of substitutions were synonymous. This bias against substitutions producing amino acid replacements and the use of Pfu DNA polymerase with an error rate 10 times lower than the observed frequency of substitution, suggests that most substitutions were not artefactual. This data suggests that individual genomes of HGV within an infected individual may differ from each other at 0.23–0.84% nucleotide position and at 0.42–0.61% amino acid position.     

热力学模型对石油低压汽液平衡计算的适用性

以Maxwell-Bonnel图拟合式、对比态Antoine方程及Pitzer-Riedel关联式分别求算饱和蒸汽压P^0,并用RoultK值（K＝P^0／P）,计算窄留分K值。根据实测的中原、孤岛和克拉玛依石油馏分低压K值,考察上述三式,结果表明：对比态Antoine式预测精度是最好的,其温度预测绝对平均偏差为7．0℃,K值预测平均相对偏差为15．6％,其他两模型偏差均较大。     

Interphotoreceptor Retinol-Binding Protein Ameliorates Diabetes-Induced Retinal Dysfunction and Neurodegeneration Through Rhodopsin

Patients with diabetes often experience visual defects before any retinal pathologies are detected. The molecular mechanism for the visual defects in early diabetes has not been elucidated. Our previous study reported that in early diabetic retinopathy (DR), rhodopsin levels were reduced due to impaired 11-cis-retinal regeneration. Interphotoreceptor retinol-binding protein (IRBP) is a visual cycle protein and important for 11-cis-retinal generation. IRBP levels are decreased in the vitreous and retina of DR patients and animal models. To determine the role of IRBP downregulation in the visual defects in early DR, we induced diabetes in transgenic mice overexpressing IRBP in the retina. IRBP overexpression prevented diabetes-induced decline of retinal function. Furthermore, IRBP overexpression also prevented decreases of rhodopsin levels and 11-cis-retinal generation in diabetic mice. Diabetic IRBP transgenic mice also showed ameliorated retinal oxidative stress, inflammation, apoptosis, and retinal degeneration compared with diabetic wild-type mice. These findings suggest that diabetes-induced IRBP downregulation impairs the regeneration of 11-cis-retinal and rhodopsin, leading to retinal dysfunction in early DR. Furthermore, increased 11-cis-retinal–free opsin constitutively activates the phototransduction pathway, leading to increased oxidative stress and retinal neurodegeneration. Therefore, restored IRBP expression in the diabetic retina may confer a protective effect against retinal degeneration in DR.     

儿童臀肌挛缩症免疫发病机理的研究

本文对４１例儿童臀肌挛缩症患者外周血及３２例儿童臀肌挛缩症臀肌进行了系统的免疫学研究。结果表明：儿童臀肌挛缩症患者免疫调节功能紊乱，红细胞免疫功能低下，臀肌组织免疫复合物沉积，臀肌小血管数目减少及管壁损伤。由此认为免疫病理因素是儿童臀肌挛缩症的主要发病机理。     

小脑和脑干梗塞致突发性耳聋

目的:了解小脑和脑干梗塞引起的突发性耳聋的临床特点.探讨其发病机制.方法:回顾性分析12例小脑和脑干梗塞所致突发性耳聋的临床资料.结果:该组患者主要临床表现为耳聋、眩晕、耳鸣、眼震、同侧颜面麻木感.头颅CT或MRI发现小脑或脑干有小于2 cm的梗塞灶.结论:发病机制主要为小脑前下动脉(AlCA)供血不足使小脑脑桥角或脑干缺血,损伤该区域的耳蜗神经和听神经传导通路,导致耳聋.小脑和脑干梗塞的诊断主要依据临床表现、CT或MRI检查.     

运用原位DNA末端标记法研究细胞凋亡对乳腺癌预后的影响

研究临床乳腺癌标本中细胞凋亡的发生情况,评价其在预测后在的意义。方法搜集９１例浸润性乳腺癌的石蜡组织切片,运用原位ＤＮＡ断裂位点的末端标记法,检测细胞凋亡,计算凋亡细胞占肿瘤细胞的百分比,求得凋亡指数。结果本组病例细胞凋亡发生率为９１．２％,凋亡指数分为两组：０～０．２１和０．２８～０．６２,凋亡指数高低与腋淋巴结转称相关（Ｐ＜０．０１）。生存率单因素分析中,凋亡指数高的病例,无病生存率（Ｐ＝０．００９５）及总生存率（Ｐ＝０．０３４８）均优于凋亡指数低的病例。但Ｃｏｘ模型多因素分析末能指示凋亡指数是一个独立的预后指标。结论在乳腺癌组织中,细胞凋亡是一种自发现象,其发生情况各有不同,研究初步提示了细胞凋亡在乳腺癌预后中的作用,了解了凋亡和腋淋巴结转移的相关性。     

胃肠道癌手术与门静脉单细胞转移的相关性研究

目的 进一步了解在胃癌、大肠癌的根治过程中,手术对单细胞转移的影响。方法 １７２例２分２组,阳性受检组１１１例,先结扎肿瘤区引渡以血和的阴性对照组６１例。开腹探后将导管置入门静脉抽取血标本,抗上皮细胞膜克隆抗体为探针,ＡＢＣ免疫组化法检测门静脉癌细胞。结果 阳性受检组１１１例患者中有７２例发现肿瘤细胞、阳性率为６４．９％,有性对照组的６１例仅发现１３例,阳性率为２１．３％,两组且间差异有显著性,     

三级肝硬化患者血浆中支链氨基酸与芳香氨基酸数值的变化及分析

目的;观察三级肝硬化患者血浆中支链氨基酸与芳香氨基酸数值的变化情况。方法：使用氨基酸分析仪检测三级肝硬化患者氨基酸数值。结果：随肝病加重,支／芳比值逐渐减低,各组间的差异具有显著性。结论：支／芳比值可作为了解肝硬化病情严重程度和判断预后的指标。