两种系膜增殖性肾炎大鼠模型的建立比较

目的　探讨快速建立系膜增殖性肾炎大鼠模型的方法。方法　 30只SD大鼠随机分 3组。正常对照组 ;葡萄球菌内毒素 (SEB)静脉注射 ,牛血清白蛋白 (BSA)隔日口服及免疫佐剂皮下注射组 ;在第二组基础上加作肝左叶切除组。 14周后分别作尿蛋白 ,IGA免疫荧光及病理组织检查。结果　肝左叶切除组蛋白尿出现的时间早于非肝切除组 ,但两组在 14周后蛋白尿定量无明显统计学差异 (P >0 0 5 ) ,对照组尿蛋白定性始终均为阴性。光镜检测轻至中度系膜扩张 ,伴系膜细胞少量增生 但两组比较无明显统计学意义 (P >0 0 5 ) ,肝左叶切除组IgA免疫荧光强于非肝切除组。结论　葡萄球菌肠内毒素静脉注射、BSA隔日口服、免疫增强剂或在上述基础上加肝左叶切除的方法都能诱发SD大鼠系膜增殖性肾炎模型。肝左叶切除组蛋白尿出现时间早 ;但于 14周后尿蛋白量无显著差异。     

Rational design of a more stable penicillin G acylase against organic cosolvent

We have used a simple and efficient approach by combining the known functional and structural properties of penicillin G acylase (PGA) from E. coli, and tried to mutate PGA of Bacillus megaterium with the goal of increasing the stability of the enzyme in organic solvents or at acidic pH. The PGA mutants Kβ427A, Kβ430A and Kβ427A/Kβ430A obtained have higher stability in DMF than the wild-type PGA.     

High expression of Trigonopsis variabilis -amino acid oxidase in Pichia pastoris

To explore a new approach of high expression of -amino acid oxidase (DAAO) in Pichia pastoris, a gene encoding DAAO from Trigonopsis variabilis (TvDAAO gene) deleted intron was prepared by PCR amplification and cloned into the intracellular expression vector pPIC3.5K. The expression plasmid pPIC3.5K-DAAO linearized by SalI was transformed into Pichia pastoris strain GS115 (his⁻mut⁺). By means of MM and MD plates and PCR, the recombinant P. pastoris strains (his⁺mut⁺) were obtained. Activity assay and SDS-PAGE demonstrated that DAAO was intracellularly expressed in P. pastoris with the induction of methanol. The recombinant strain PD27 with the highest expression of DAAO was screened through activity assay and its high-density fermentation was carried out in a 1-l fermentor. Activity assay and SDS-PAGE demonstrated that DAAO was intracellularly expressed in P. pastoris with the induction of methanol. The recombinant cells with high expression of DAAO were screened and the high-density fermentation was carried out in a 1-l fermentor. Interestingly, the DAAO expression level reached up to 473 U/g dry cell weight in fermentation yield. Finally, 1-hexanol was used to break recombinant cells and the specific activity of DAAO was 1.46 U/mg protein in crude extraction.     

水稻穗颈维管束及穗部性状的QTL分析

以籼稻 (OryzasativaL .ssp .indicaZYQ8)和粳稻 (O .sativassp .japonicaJX17)的杂交F1代花培加倍的DH群体为材料考察了该群体的穗颈节大小维管束数、一次枝梗数、每穗颖花数、穗颈节顶部直径和穗长 ,并用该群体构建的分子图谱进行数量性状座位 (QTL)分析。检测到控制大维管束的 3个QTL (qLVB_1、qLVB_6和qLVB_7)分别位于第 1、第 6和第 7染色体 ;控制小维管束的 2个QTL (qSVB_4和qSVB_6 )分别位于第 4和第 6染色体 ;控制一次枝梗的 4个QTL (qPRB_4a、qPRB_4b、qPRB_6和qPRB_7)分别位于第 4(2个 )、第 6和第 7染色体 ;每穗颖花数的 3个QTL (qSPN_4a、qSPN_4b和qSPN_6 )分别位于第 4(2个 )和第 6染色体上 ;穗颈节顶部直径的 5个QTL (qPTD_2、qPTD_5、qPTD_6、qPTD_8和qPTD_12 )分别位于第 2、第 5、第 6、第 8和第 12染色体 ;穗长的 3个QTL (qPL_4、qPL_6和qPL_8)分别位于第 4、第 6、第 8染色体上。其中qLVB_6、qSVB_6、qSPN_6、qPTD_6和qPL_6均位于第 6染色体的G12 2_G1314b之间 ;qPL_8和qPTD_8位于第 8染色体的GA40 8_BP12 7a之间 ;qPRB_4a和qSPN_4a位于第 4染色体的G177_CT2 0 6之间 ;qPL_4和qSPN_4b位于第 4染色体CT40 4_CT5 0 0之间 ;qSVB_4所在的区间与qPL_4、qSPN_4b和qPRB_4b所在的区间相邻。     

一种标记cDNA芯片探针的新方法

探讨mRNA长片段反转录PCR技术(RT-LDPCR)在cDNA芯片微量探针标记和信号放大中的应用.首先提取BEP2D细胞的总RNA,然后用两种不同的方法进行标记,一种为RT-LDPCR,用荧光素Cy3-dCTP进行标记;另一种为传统的RNA反转录,用荧光素Cy5-dCTP进行标记.将两种方法标记好的探针等量混合后与含有440个点(44个基因)的cDNA芯片同时杂交,发现二者具有很高的一致性(0.5＜Cy3/Cy5＞2.0).由于RNA反转录法为cDNA芯片探针标记的传统方法,从而验证了RT-LDPCR用于cDNA芯片探针标记的可行性.RT-LDPCR具有对样品总RNA的需要量少和可对样品中信号进行放大的优点,特别适合于对材料来源受到限制的RNA进行标记.     

A Novel Family of Magnesium Transport Genes in Arabidopsis

Magnesium (Mg(2+)) is the most abundant divalent cation in plant cells and plays a critical role in many physiological processes. We describe the identification of a 10-member Arabidopsis gene family (AtMGT) encoding putative Mg(2+) transport proteins. Most members of the AtMGT family are expressed in a range of Arabidopsis tissues. One member of this family, AtMGT1, functionally complemented a bacterial mutant lacking Mg(2+) transport capability. A second member, AtMGT10, complemented a yeast mutant defective in Mg(2+) uptake and increased the cellular Mg(2+) content of starved cells threefold during a 60-min uptake period. (63)Ni tracer studies in bacteria showed that AtMGT1 has highest affinity for Mg(2+) but may also be capable of transporting several other divalent cations, including Ni(2+), Co(2+), Fe(2+), Mn(2+), and Cu(2+). However, the concentrations required for transport of these other cations are beyond normal physiological ranges. Both AtMGT1 and AtMGT10 are highly sensitive to Al(3+) inhibition, providing potential molecular targets for Al(3+) toxicity in plants. Using green fluorescence protein as a reporter, we localized AtMGT1 protein to the plasma membrane in Arabidopsis plants. We suggest that the AtMGT gene family encodes a Mg(2+) transport system in higher plants.     

害虫防治决策的复序贯分析方法及抽样技术研究

复序贯抽样决策技术实际应用的受限 ,原因在于截止限序贯抽样模型的缺乏。本文在检验昆虫种群空间格局回归模型的基础上 ,推导出了目前国内常用检验回归模型的截止限序贯抽样模型 ,并将其运用于复序贯分析决策过程中。实例分析表明 ,对于同一种生物种群 ,在一定的精度 (D)和置信水平(tα)要求下 ,复序贯抽样决策技术可以大幅度地节约抽样成本     

烤烟品种资源的RAPD分析

从156个随机引物中筛选出30个引物,对来自国内外的31个烤烟品种进行了遗传多样性和亲缘关系的RAPD分析。在检测的246个位点中,127个位点为多态位点（52％）。聚类分析表明,不同烤烟品种之间存在明显差异,31个品种基本上可分为4大类,品种最多的第一大类（19个）主要由来自美国的Orinoco烤烟选育而成,反映了我国现在推广的烤烟品种遗传基因比较狭窄。研究结果表明,RAPD技术可用于烤烟品种的鉴别和纯度测定。研究为烤烟杂种育种中亲本的选配提供了一定的理论依据。     

DNA repair enhancement of aqueous extracts of Uncaria tomentosa in a human volunteer study.

The Uncaria tomentosa water extracts (C-Med-100) have been shown to enhance DNA repair, mitogenic response and leukocyte recovery after chemotherapy-induced DNA damage in vivo. In this study, the effect of C-Med-100 supplement was evaluated in a human volunteer study. Twelve apparently healthy adults working in the same environment were randomly assigned into 3 groups with age and gender matched. One group was daily supplemented with a 250 mg tablet containing an aqueous extract of Uncaria tomentosa of C-Med-100, and another group with a 350 mg tablet, for 8 consecutive weeks. DNA repair after induction of DNA damage by a standard dose of hydrogen peroxide was measured 3 times before supplement and 3 times after the supplement for the last 3 weeks of the 8 week-supplement period. There were no drug-related toxic responses to C-Med-100 supplement when judged in terms of clinical symptoms, serum clinical chemistry, whole blood analysis and leukocyte differential counts. There was a statistically significant decrease of DNA damage and a concomitant increase of DNA repair in the supplement groups (250 and 350 mg/day) when compared with non-supplemented controls (p < 0.05). There was also an increased tendency of PHA induced lymphocyte proliferation in the treatment groups. Taken together, this trial has confirmed the earlier results obtained in the rat model when estimating DNA repair enhancement by C-Med-100.