应用蛋白印迹法检测鼻咽癌病人血清中抗Epstein—Barr病毒IgA/EA抗体

曾毅等建立了一系列检测EB病毒IgA/VCA和IgA/EA抗体的鼻咽癌早期诊断方法,取得了满意的结果。为了进一步提高对鼻咽癌诊断更为特异的IgA/EA抗体的检出率,我们建立了检测EB病毒IgA/EA抗体的蛋白印迹法。方法敏感特异,结果令人满意。 本法中所用的两个质粒系由本实验室与西德Pettenkofer研究所Wolf教授的实验室合作构建。pUCARG1140和pUC9MBcE3.2质粒均为表达质粒,前者携带着来源于EB病毒Bam     

应用明胶颗粒凝集试验检测人免疫缺陷病病毒(HIV-1)抗体

明胶颗粒凝集试验是测定HIV-1抗体的新方法。本研究将明胶颗粒凝集试验与ELISA法、蛋白印迹法和间接免疫荧光试验做了比较,观察本方法的敏感性和特异性。共检测了195份来自法国和非洲象牙海岸的血清,凡是蛋白印迹法阳性的血清,明胶颗粒凝试验都是阳性。这表明本方法是特异和敏感的,方法简便,不需特殊仪器,省时,可用于HIV-1抗体的筛选,但多数蛋白印迹法可疑的血清,明胶颗粒试验均阴性。因此,对蛋白印迹法测出的可疑者应该用数种方法进行追踪检测。     

樗蚕丝腺5SrRNA的核苷酸顺序

本文用凝胶直读法、末端鉴定法等相配合,测定了樗蚕(Philosamia cynthia)絲腺5SrRNA的核苷酸顺序:AGACAACGUCCAUACCACGUUGAAAACACCGGUUCUCGUCCGAUCACCGAAGUCAAGCAACGUCGGGCGCGGUCAGUACUUGGAUGGGUGACCGCCUGGGAACACCGCGUGCUGUUGGCUU比较了樗蚕、蓖麻蚕、柞蚕、家蚕、果蝇等5SrRNA结构差异,在分子水平上探讨了昆虫的分化。     

Expression of c-myc protooncogene in rat lens cells during development,maturation and reversal of galactose cataracts

It is well established that normal patterns of epithelial cell proliferation and metabolism, and of fiber cell differentiation and maturation are essential for the maintenance of transparency in the ocular lens. Several factors, including exposure to high levels of sugars, have been known to result in the compromise of lens transparency. For example, initiation of lens cell damage by galactose induces lens epithelial cells to proliferate. Elevated levels of c-myc mRNA have usually been correlated with rapid cell growth and increased entry of cells into the S phase. Therefore, changes in c-myc mRNA levels may provide an early indication of the stimulation of lens epithelial cells to proliferate and differentiate, which has been postulated to be an early and important event in response to lens cell injury by galactose. By Northern blot hybridization analysis we quantitated c-myc mRNA levels in the lens capsule epithelia of rats (1) exposed to galactose, and (2) undergoing a partial recovery from the galactose-induced cell damage. At the onset of lens cell damage, we find c-myc mRNA to elevate to 6-fold by 24 hr, and by 48 hr decreases to about 3-fold the normal levels. During recovery, c-myc mRNA continues to be expressed at high levels approaching a 10-fold increase by day 12, then decreasing to levels of about 8-fold the control by day 30. The 24 h transitory elevation in c-myc mRNA in lens epithelial cells is in accord with our previous observations on the 24 h increase in MP26, crystallin and aldose reductase mRNAs following a high influx of galactose. Therefore, the elevation in c-myc mRNA as well suggest that galactose appears to cause lens cells to undergo an early transitory period of gene induction following the exposure of lens cells to galactose.     

Assignment of a novel protein tyrosine phosphatase gene (Hcph) to mouse chromosome 6.

Hematopoietic cell phosphatase (Hcph) was identified by amplification of conserved protein tyrosine phosphatase sequences from a myeloid cell line and is predominantly expressed in hematopoietic cells. Hcph is unique in containing two, tandemly repeated, src-homology 2 domains in the amino terminal region of the phosphatase. Using a genomic probe in interspecific backcross analysis, the murine Hcph gene maps to mouse Chromosome 6 and is tightly linked to the Tnfr-2 and Ly-4 genes.     

The 32-kilodalton envelope protein of vaccinia virus synthesized in Escherichia coli binds with specificity to cell surfaces.

The nature of interaction between vaccinia virus and the surface of host cells as the first step in virus infection is undefined. A 32-kDa virus envelope protein has been identified as a cell surface binding protein (J.-S. Maa, J. F. Rodriguez, and M. Esteban, J. Biol. Chem. 265:1569-1577, 1990). To carry out studies on the structure-function relationship of this protein, the 32-kDa protein was obtained from Escherichia coli cells harboring the expression plasmid pT7Ek32. The recombinant polypeptide was found to have structural properties similar to those of the native virus envelope protein. Binding studies of 125I-labeled 32-kDa protein to cultured cells of various origins revealed that the E. coli-produced 32-kDa protein exhibited selectivity, specificity, and saturability. Scatchard analysis indicated about 4.5 x 10(4) sites per cell with a high affinity (Kd = 1.8 x 10(-9) M), suggesting interaction of the 32-kDa protein with a specific receptor. The availability of large quantities of the 32-kDa virus protein in bacteria will permit further structural and functional studies of this virus envelope protein and facilitate identification of the specific cell surface receptor.     

Multiplicity of soluble glucan-synthase activity in spinach leaves: Enzyme pattern and intracellular location

Buffer-extractable proteins from leaves of Spinacia oleracea L. were separated by non-denaturing polyacrylamide gel electrophoresis. Gels were stained for adenosine diphosphoglucose (ADPglucose)-dependent glucan-synthase (GS) activity (EC 2.4.1.21). Three major forms of activity were observed. No staining was detectable when ADPglucose was replaced by an equimolar concentration of either uridine, guanosine or cytosine diphosphoglucose. Two of the three GS forms exhibited both primed and citrate-stimulated unprimed activity whereas one enzyme form was strictly dependent upon the presence of an exogenous glucan. For intracellular localization, mesophyll protoplasts and intact chloroplasts were isolated and their enzyme pattern was compared with that of the leaf extract. Intactness and purity of the chloroplast preparations were ascertained by polarographic measurement of the ferricyanide- or CO₂-dependent oxygen evolution, by determination of marker-enzyme activities, and by electrophoretic evaluation of the content of chloroplast- and cytosol-specific glucanphosphorylase forms (EC 2.4.1.1). The three GS forms were present in mesophyll protoplasts. Intact chloroplasts possessed both primer-independent enzyme forms but lacked the primer-dependent one. The latter form was enriched in supernatant fractions of leaf homogenates when the intact chloroplasts had been pelleted by centrifugation. Thus, in spinach-leaf mesophyll cells soluble ADPglucose-dependent GS is located both inside and outside the chloroplast.Abbreviations GS glucan synthase - PAGE polyacrylamide gel electrophoresis This work has been made possible by grants from the Deutsche Forschungsgemeinschaft and from the Minister für Wissenschaft und Forschung des Landes Nordrhein-Westfalen. The authors gratefully acknowledge the generous permission to use the laser densitometer of Professor Dr. W. Barz (Biochemie der Pflanzen, Universität Münster, FRG). They are indebted to Dr. H.-J. Witt (Pflanzenphysiologie, Universität Kassel, FRG) for helpful discussions and to Mr. W. Lamkemeyer for skilfull technical assistance.     

Changes in pulmonary Cu−Zn contents in superior mesenteric artery occlusion shock of rabbit

Contents of Cu and Zn of into-pulmonary blood (IPB), out-pulmonary blood (OPB), Lung tissue, and supernatant and macrophages of Lung Lavage were determined in superior mesenteric artery occlusion (SMAO) shock of rabbits. Zn of pulmonary tissue was 11.42 +/- 0.60 and 14.52 +/- 1.78 (micrograms/g wet wt) in SMAO shock and control groups, respectively. Content of Zn was found to be lower, Cu was not changed, and Cu/Zn ratio increased in lung tissue in SMAO shock. Contents of Cu and Zn in other samples were not changed. The results suggest that lower Zn in lung tissue related to acute lung injury.     

用2DNMR鉴定倍半萜多元酯的结构

利用2DNMR结合其他波谱方法从苦皮藤种子油中鉴定了2个新倍半萜多元酯,它们分别是1α-苯甲酰氧-8β-烟酰氧-9α、11β-2乙酰氧-β-二氢沉香呋喃,1β-苯甲酰氧-2α、8β、9α、11β-4乙酰氧-β-二氢沉香呋喃,命名为苦皮藤酯2和3。     

对冷适应大鼠棕色脂肪和肝脏在非寒颤产热机制中作用的评价

本实验主要观察并比较了大鼠冷适应前后直肠温度(RT)、血清游离脂肪酸(SFFA)浓度、肩胛间棕色脂肪组织(IBAT)和肝脏cAMP含量的变化及其对去甲肾上腺素(NE)反应性的改变。结果表明:①冷适应28d大鼠在冷环境中RT稳定,NE刺激后RT上升幅度大于常温对照组(P<0.005);②冷适应1d组SFFA升高,冷适应28d组SFFA接近对照组,且对NE刺激无反应,对照组给NE后SFFA与RT一致性升高;③冷适应28d组IBAT的cAMP升高,而肝脏的cAMP含量三组间无显著性差异。NE刺激后,冷适应28d组IBAT和肝脏cAMP均升高,与RT反应一致,而对照组不变。结果提示,在5±3℃适应28d的大鼠已建立冷适应机制,非寒颤产热(NST)容量增加,在冷适应的不同时期,肝脏和IBAT调节NST的机制不同。