赖型钩端螺旋体重组DNApCX7的特异性鉴定和限制性内切酶谱分析

本实验将赖型钩端螺旋体（简称钩体）ＤＮＡ基因库的克隆ｐＣＸ７制备成￣（３２）Ｐ－重组ＤＮＡ探针，对８个不同血清群的１７株问号状钩体、双曲钩体ＰａｔｏｃⅠ株以及细螺旋体３０５５株ＤＮＡ进行打点杂交；同时用１５种ＤＮＡ片断进行限制性内切酶谱分析。结果表明，该重组ＤＮＡ具有问号状钩体种（Ｓｐｅｃｉｅｓ）特异性，但与不同问号状钩体之间的同源性程度有差别；限制性内切酶谱分析发现ｐＣＸ７重组ＤＮＡ片段长约１．７ｋｂ，具有１个Ｂｇ１Ⅱ识别位点和３个ＢｓｔＢ１识别位点。     

伊那普利治疗糖尿病肾病的临床研究

目的评估伊那普利治疗糖尿病肾病(DN)的临床疗效 ,并探讨其作用机制。方法40例持续微量蛋白尿的非胰岛素依赖型糖尿病(NIDDM)患者随机分为常规治疗组(n=19)和伊那普利治疗组(n=21)。利用 131I -邻碘马尿酸钠测定有效肾血浆流量(ERPF) ;肾小球滤过率(GFR)以内生肌酐清除率表示 ;通过ELISA法测定尿微量蛋白 ,包括白蛋白(ALB)、转铁蛋白(TF)、视黄醇结合蛋白(RBP)和N -乙酰 - β氨基葡萄糖苷酶(NAG)。结果伊那普利治疗组增高的尿ALB、TF、RBP和NAG均显著下降 ;ERPF显著增加 ;增加的滤过分数(FF)显著减低。而常规治疗组这些参数无显著变化。结论伊那普利具有改善DN患者的肾小球血流动力学 ,保护肾小球和肾小管功能的作用     

人白细胞干扰素诱导慢性乙型肝炎病人DNA损伤修复的探讨

应用不同浓度人白细胞干扰素处理10例慢性乙型肝炎病人外周血淋巴细胞,观察病人姐妹染色单体互换(SCE)频率的动力学变化.结果表明,人白细胞干扰素处理组SCE平均频率明显低于对照组,差异高度显著(P<0.01);慢性迁延性肝炎和慢性活动性肝炎处理组之间SCE平均频率无显著性差异;但人白细胞干扰素处理低浓度组SCE平均频率低于高浓度组,差异不显著(P>0.05).提示人白细胞干扰素具有诱导HBV损伤人体DNA的修复作用;大剂量人白细胞干扰素对HBV损伤人体DNA的修复未必有益.     

EFFECTS OF ANGIOTENSINS II AND III ON GLOMERULOTUBULAR BALANCE IN RATS

1. The role of angiotensin as a modulator of proximal glomerulotubular (GT) balance was investigated in anaesthetized rats by examining the relationship between glomerular filtration rate (GFR) and absolute proximal reabsorption (APR) during removal of endogenous angiotensin II (AII) and III (AIII) with enalaprilat (CEI) and then during their subsequent replacement by intravenous infusions. 2. Enalaprilat lowered mean arterial blood pressure (MABP) and increased renal blood flow (RBF), GFR, urine flow rate and sodium excretion. Filtration fraction (FF) was not altered. Absolute proximal reabsorption, derived from fractional lithium clearance, increased by only 48% of the change expected for 'perfect' GT balance. 3. Angiotensin II replacement corrected MABP, GFR and plasma renin level, but reduced RBF and increased FF; APR was decreased and GT balance was restored. Urine flow and sodium excretion remained above control values with AII. 4. Replacement with AIII did not correct the hypotension but completely reversed the renal and renin responses to enalaprilat and restored GT balance without affecting FF. 5. It was concluded that the relation between proximal reabsorption and GFR is considerably modified by the intrarenal angiotensin concentration. The findings are best explained by a direct stimulation of proximal tubular sodium transport by angiotensin at the concentrations existing in anaesthetized rats.     

Analysis of the mechanism of action of bradykinin on human basilar artery in vitro

Summary Bradykinin (BK) initially produced concentration-related relaxations of human basilar artery in vitro. Concentration-effect curves constructed at 2 h intervals to BK over an 8 h period were reproducible. The rank order of potency of three kinins on the human basilar artery was found to be BK > methionyl-lysyl-BK > des-Arg⁹-BK. The B₂-receptor antagonist Thi^5,8 d-Phe⁷-BK but not the B₁-receptor antagonist des-Arg⁹-Leu⁸-BK selectively blocked BK-induced relaxations of the human basilar artery.The relaxant effects of bradykinin and acetylcholine but not papaverine were attenuated after removal of the endothelium or treating the tissues with BW755C. Indomethacin was without effect. Concentration-effect curves to angiotensin I were markedly attenuated by captopril at a concentration which had no effect on BK, angiotensin II or 5-hydroxytryptamine responses. It is concluded that BK induced relaxations of the human basilar artery are mediated via activation of a B₂ receptor and the response is dependent upon the release of a factor present in the endothelium. Angiotensin converting enzyme is present in the human basilar artery and is important for the conversion of angiotensin I to angiotensin II but apparently not for the degradation of BK. It is likely that other kininases are present and active in the tissue. Send offprint requests to E. T. Whalley at the above address     

影响α-淀粉酶分离液澄清度的因素

本文根据凝聚和絮凝原理,研究了无机盐和高分子絮凝剂加入量对枯草杆菌BF 7658α-淀粉酶分离液澄清度的影响。实验结果表明,氯化钙可使α-淀粉酶发酵液的ζ电位降低,分离液的澄清度增加,用氯化钙和磷酸氢二钠来处理发酵液,则其分离液的澄清度较单用氯化钙为大,阴离子型高分子絮凝剂如海藻酸钠加入量对分离液澄清度也有一定影响。实验中还发现,澄清的发酵液在10℃下贮存可保持澄清透明状态。     

Early onset of autoimmunity in MRL/++ mice following immunization with beta 2 glycoprotein I.

Antiphospholipid antibodies (aPL) are associated with thrombosis, thrombocytopenia and recurrent fetal loss in humans and in some animal models. Immunization with beta 2 glycoprotein I (beta 2GPI) induced aPL production in normal rabbits and mice. However, the association of these antibodies with disease manifestations remains controversial. To determine whether induction of aPL by beta 2GPI immunization in an autoimmune strain of mice (MRL/++) would result in acceleration of clinical and serological autoimmune disease manifestations, three groups of 8-week-old female mice were studied. One group was immunized with beta 2GPI, and one with ovalbumin (OVA); the third was not immunized. After two booster injections, sera were analysed for the presence of anticardiolipin (aCL) and anti-DNA by ELISA and anti-nuclear antibody (ANA) by immunofluorescence. Mice were studied for thrombocytopenia, proteinuria, fecundity rates, litter sizes and the development of central nervous system dysfunction. Elevated levels of aCL, anti-DNA and ANA were detected in all beta 2GPI-immunized, in three OVA-immunized, and in none of the unimmunized mice. The anti-DNA antibodies were inhibited by CL micelles, suggesting cross-reactivity between aCL and anti-DNA. Platelet counts, fecundity rates and litter size were reduced in beta 2GPI-immunized but not in OVA-immunized or unimmunized mice. None of the mice developed neurological dysfunction or significant proteinuria over a 10-week period post-immunization. These findings suggest that beta 2GPI immunization induces aPL in MRL/++ mice associated with accelerated autoimmune manifestations resembling the antiphospholipid syndrome.     

The potential of topoisomerase I inhibitors in the treatment of CNS malignancies: report of a synergistic effect between topotecan and radiation

Summary Despite innovations in imaging, surgery, and radiation therapy, local failure remains the principle clinical problem in most CNS malignancies. To date, chemotherapy has not made a major impact in the treatment of most adult CNS tumors. The inroads made by chemotherapy in pediatric CNS malignancies suggest that novel drugs, or drug combinations, may improve therapy. Topoisomerase I (Topo I) inhibitors are a relatively new group of chemotherapy drugs with a novel mechanism of action. Drugs in this group currently undergoing clinical trials are the Camptothecin analogues Topotecan, CPT-11, and 9-aminocamptothecin. There is substantial preclinical and some clinical evidence to suggest that these drugs could be useful in the treatment of CNS malignancies. Preclinical studies with the water soluble Topo I inhibitor, Topotecan, demonstrate antineoplastic activity in a variety of CNS malignancies. In addition, Topotecan has good CNS penetration in primates, and recent preliminary phase I and II clinical trials of Topotecan in pediatric and adult CNS malignancies have been promising. In this paper, we describe the unique mechanism of action, antineoplastic activity, and radiosensitizing properties of Topo I inhibitors. We present the first report demonstrating potentiation of radiation lethality by Topotecan in a human glioma (1354) cell line. The dose enhancement ratio was 3.2 at 10% survival. Thus, there is evidence to suggest that Topo I inhibitors may be beneficial in the treatment of CNS neoplasms on the basis of their antineoplastic activity alone, as well as their radiosensitizing effects. Two clinical trials which utilize concurrent Topotecan and radiation in the treatment of pediatric and adult CNS malignancies are discussed.     

大肠杆菌表达耐热DNA聚合酶的纯化和鉴定

目的探讨工程菌表达的耐热ＤＮＡ聚合酶的纯化方法。②方法收集ＩＰＴＧ诱导带有耐热ＤＮＡ聚合酶（ＴＤ聚合酶）基因表达质粒的工程菌株ＤＨ－ＴＤ４，用溶菌酶裂解，６０℃处理后，上清液用硫酸铵沉淀，根据溶解度差异进行粗分级，然后进行离子交换层析细分级，并经聚合酶链式反应（ＰＣＲ扩增）鉴定其活性。③结果纯化的ＴＤ聚合酶具有良好的聚合活性。④结论溶解度差异与离子交换层析是工程菌表达的耐热ＤＮＡ聚合酶纯化的主要步骤。基因工程制备的ＤＮＡ聚合酶可用于ＰＣＲ检测