东方人苯丙酮尿症的分子遗传学—苯丙氨酸羟化酶基因中一终止突变与单体型4的连锁不平衡性

应用聚合酶链反应(PCR)方法扩增苯丙氨酸羟化酶(PAH)基因的每个外显子及其侧翼的内含子,并克隆到M 13载体中进行序列分析。发现中国人苯丙酮尿症(Phenylketonuria,PKU)患者的PAH基因外显子3中有1个Arg~(111)→Ter~(111)的点突变,此突变与东方人最常见的突变单体型4呈连锁不平衡。此突变占中国人PAH等位基因的10％左右,但不存在于高加索人群中,表明在种族分化过程中PAH基因位点发生了互不相关的突变事件。     

消化系疾患的血清氨基酸检测

本文报告50名正常人及73例消化系疾病患者血清游离氨基酸检测结果。使用氨基酸自动分析仪,对血中40余种氨基酸组分进行定性定量测定。肝硬化病人芳香氨基酸显著升高,支/芳分子比值明显低于正常值(P<0.01),甲硫氨酸、色氨酸均升高.肝脓疡.消化道肿瘤患者也有此种变化(P<0.05)。统计21种组分中,各病理组有10多种组分有非常显著差异(P<0.01)。结果提示:血液氨基酸测定可为某些消化系疾患,尤其是肝病的诊治提供较好指标。本文改进自动分析条件,节省时间。节约试剂。     

Toll样受体2胞外域及其氨基端和羧基端片段的克隆与序列分析

目的：为研究TLR2胞外域在肽聚糖诱导的信号转导中的功能，构建TLR2胞外域及其氨基端和羧基端片段真核表达载体。方法：提取HL－60细胞总RNA，以RT－PCR方法获取了TLR2胞外域cDNA片段，将其与pGEM-T Easy载体连接，转化E.coli JM109,建立了TLR2胞外域的cDNA克隆；籍此，又相继克隆了胞外域的氨基端和羧基端片段，然后将这三个片段克隆到真核表达载体pcDNA3中。结果：序列分析表明，与GenBank中的人TLR2全长cDNA序列比较，仅4个碱基不同，同源性为0．998。结论：成功获得了HL－60细胞TLR2胞外域及其氨基端和羧基端片段的克隆。     

The phylogeny of howler monkeys (Alouatta, Platyrrhini): Reconstruction by multicolor cross-species chromosome painting

We performed multidirectional chromosome painting in a comparative cytogenetic study of the three howler monkey species Alouatta fusca, A. caraya and A. seniculus macconnelli (Atelinae, Platyrrhini) in order to reconstruct phylogenetic relationships within this genus. Comparative genome maps between these species were established by multicolor fluorescence in-situ hybridization (FISH) employing human, Saguinus oedipus and Lagothrix lagothricha chromosome-specific probes. The three species included in this study and previously analyzed howler monkey species were subjected to a phylogenetic analysis on the basis of a data matrix comprised of 98 discrete molecular cytogenetic characters. The results revealed that howler monkeys represent the genus with the most extensive karyotype diversity within Platyrrhini so far analyzed with high levels of intraspecific chromosomal variability. Two different multiple sex chromosome systems were identified. The phylogenetic analysis indicated that Alouatta is a monophyletic clade which can be derived from a proposed ancestral Atelinae karyotype of 2n=62 chromosomes by a chromosome fusion, a fission, a Y-autosomal translocation and a pericentric inversion. Following these suggestions, the genus Alouatta can be divided into two distinct species groups: the first includes A. caraya and A. belzebul, the second A. s. macconnelli, A. sara, A. s. arctoidea and A. fusca.     

镉对大鼠肾脏和睾丸毒性的比较

大鼠饮水中给镉12wk后,检测了尿低分子蛋白(LMWP)排出量。尿碱性磷酸酶(ALP)活性,血清睾酮水平,睾丸乳酸脱氢酶同功酶(LDH-X)活性,精子计数和形态,雄鼠生育力,肾,睾丸和附睾组织镉含量,并在光镜和电镜下观察上述组织的病理变化,从生化,形态和功能改变三方面比较了大鼠肾脏和睾丸对镉的敏感性,发现尿LMWP和ALP仅在高剂量组显著增加,而血清睾酮和睾丸LDH-X在中剂量纽和低剂量纽已明显降低,说明镉对睾丸的有害作用可出现在肾脏之前。     

Structural variations in the crystal structures of two homologous DL-Leu and Δ-Leu containing peptides+

The similar conformations and interaction modes of Ac-DL-Leu-Nme₂ and Ac-Δ-Leu-NMe₂ molecules in the solid state allow the comparison of their geometrical parameters. The most evident variations are essentially restricted to the α,β-unsaturated side-chain which adopts the Z-disposition. The dimensions of the peptide backbone are much less sensitive to α,β-unsaturation, with a small shortening by 0.04 Å and 0.02 Å of the N-C^α and C^α-C′ bonds, respectively, and an increase by 6° of the N-C^α- C′ bond angle. The ethylenic and amide groups in the Δ-Leu derivative are far from coplanarity, and a significant electronic conjugation of the π-orbital is likely to be rejected.     

小鼠轮状病毒EW株VP7基因的克隆及其在重组腺病毒中的表达

目的：构建表达小鼠轮状病毒(EDIM)EW株VP7基因的重组腺病毒，以在小鼠模型上研究轮状病毒的免疫保护机制。方法：用RT-PCR方法扩增EDIM VP7全长cDNA并进行基因序列分析，将所得的VP7基因片段插入腺病毒穿梭质粒pShuttle-CMV，获得重组质粒pShuttleCMV-EVP7，将该质粒与腺病毒骨架质粒pAdEasy-1共转化大肠杆菌BJ5183获得重组腺病毒质粒pAdCMV-EVP7，将该质粒线性化后转染293细胞包装重组腺病毒rvAdEVP7。以rvAdEVP7感染293细胞，并分别应用电子显微镜、PCR、RT-PCR和Western blot等方法观察rvAdEVP7的形态、VP7基因整合、遗传稳定性、VP7基因在细胞内转录及表达等有关生物学特性。结果：获得了小鼠轮状病毒的全长cDNA，重组腺病毒rvAdEVP7具有典型的腺病毒形态，PCR、RT-PCR和Western blot等分子生物学方法分析显示：rvAdEVP7中确有特异性的VP7基因稳定整合；有较好的遗传稳定性；感染293细胞后能有效转录；可表达轮状病毒主要结构蛋白VP7。结论：成功构建含VP7基因的重组腺病毒rvAdEVP7，为进一步研究轮状病毒的免疫保护机制打下了基础。     

脑动静脉畸形血管重构的分子生物学机制

脑动静脉畸形存在活跃的血管重构,本文就其重构的分子生物学机制作一综述。