肿瘤坏死因子－α（TNF－α）及白细胞介素1β（IL1－β）对胶质增生的影响及机理

本文利用小鼠大脑机械损伤模型及体外培养的胶质细胞,采用同位素渗入法观察了细胞介素及其抗体对胶质细胞增生的影响。结果表明：体外培养时ＴＮＦ－α在浓度为１０～２００ｕ／ｍｌ培养液时均能促进胶质细胞增生（Ｐ＜０．０５）,ＩＬ１－β在浓度为５～２００ｕ／ｍｌ培养液时能促进胶质细胞增生,ＴＮＦ－α＋ＩＬ１－β其促进胶质细胞增生作用更强烈,ＴＮＦ－α抗体能完全阻断ＴＮＦ－α的促增生作用,部分阻断ＴＮＦ－α＋ＩＬ１－β的促增生作用。在体实验时,ＩＬ１－β及ＴＮＦ－α的作用与离体时相似,ＩＬ１－β及ＴＮＦ－α亦能促进胶质细胞增生,二者共同作用时促细胞增生作用更强。以上结果提示,外源性ＴＮＦ－α及ＩＬ１－β能促进中枢神经损伤后胶质细胞增生且具有协同作用。     

EB病毒胸苷激酶基因的扩增

ＥＢ病毒胸苷激酶基因的扩增陈尚武,陈瑞君,黄迪,朱振宇,马涧泉（中山医科大学生化教研室,广州５１００８９）（中山医科大学肿瘤研究所,广州５１００６０）关键词Ｅｐｓｔｅｉｎ－Ｂａｒｒ病毒,胸苷激酶,基因,聚合酶链反应鼻咽癌（ｎａｓｏｐｈａｒｙｎｇｅａｌ...     

DAB诱发大白鼠肝癌过程中细胞质膜上酶变化的观察

本实验以二甲基氨基偶氮苯（ＤＡＢ）诱发大白鼠肝癌的动物模型为材料,观察了在诱癌过程中和肝癌形成后大白鼠肝细胞质膜上几种酶活性的变化,用不连续蔗糖密度梯度离心法制备肝细胞质膜,分光光度法对酶活性进行定量测定。实验结果表明,在诱无病癌过程中,肝细胞质膜上５′－ＡＭＰａｓｅ活性上降,γ－ＧＴａｓｅ活性显著升高。γ－ＧＴａｓｅ活性升高幅度与病理变化正相关,并且在诱癌早期就能表现出来。     

Chemical speciation of arsenic in urine of patients with blackfoot disease

Blackfoot disease is a peripheral vascular disease resulting in gangrene of the lower extremities. Although extensive epidemiological study has implicated high arsenic content in artesian well water of the endemic area bears some important connection with the disease, the etiology of the disease is still not clarified. In this study, attention is paid to chemical speciation of arsenic in order to find out whether the concentrations of arsenic species in urine of Blackfoot disease patients are different from those of controls. Experimental results indicate that the total arsenic, inorganic arsenic, monomethylarsonic acid, and other forms of arsenic in the urine of patients are significantly higher than those of the contols. The possible connection of those arsenic species with the etiology of the disease is discussed.     

Bcl-2 and Fas/APO-1 regulate distinct pathways to lymphocyte apoptosis.

Activation of the cell surface receptor Fas/APO-1 (CD95) induces apoptosis in lymphocytes and regulates immune responses. The cytoplasmic membrane protein Bcl-2 inhibits lymphocyte killing by diverse cytotoxic agents, but we found it provided little protection against Fas/APO-1-transduced apoptosis in B lymphoid cell lines, thymocytes and activated T cells. In contrast, the cowpox virus protease inhibitor CrmA blocked Fas/APO-1-transduced apoptosis, but did not affect cell death induced by gamma-radiation or serum deprivation. Signalling through Fas/APO-1 did not down-regulate Bcl-2 or induce its antagonists Bax and Bcl-xS. In Fas/APO-1-deficient lpr mice, Bcl-2 transgenes markedly augmented the survival of antigen-activated T cells and the abnormal accumulation of lymphocytes (although they did not interfere with deletion of auto-reactive cells in the thymus). These data raise the possibility that Bcl-2 and Fas/APO-1 regulate distinct pathways to lymphocyte apoptosis.     

Synthesis and antiplatelet, antiinflammatory, and antiallergic activities of 2-substituted 3-chloro-1,4-naphthoquinone derivatives

A series of 2-substituted 3-chloro-1,4-naphthoquinones was synthesized, and the antiplatelet, antiinflammatory, and antiallergic activities of these compounds were evaluated. The structure-activity relationships in this series were also examined. Most of the 2-alkyl/arylcarboxamido derivatives of 3-chloro-1,4-naphthoquinone showed potent activities with similar trends in each of the activities evaluated.     

Molecular Evolution and Phylogeny of Satellite RNA Associated with Bamboo Mosaic Potexvirus

Satellite RNA of bamboo mosaic potexvirus (satBaMV) is a linear RNA molecule which encodes a 20-kDa nonstructural protein. Sequences of seven different satBaMV isolates from bamboo hosts in three genera showed 0.7% to 7.5% base variation which spanned the whole RNA molecule. However, the putative 20-kDa open reading frame was all preserved in these isolates. The phylogenetic relationship based on the nucleotide sequence did not show particular grouping of satBaMV from the host in one genus; neither was the grouping of satBaMV evident by location of sampling. Putative secondary structures of the 3′ untranslated regions showed a basic pattern with conserved hexanucleotides (ACCUAA) and polyadenylation signal (AAUAAA) located in the loop regions. Although the satBaMV-encoded 20-kDa protein is a nonstructural protein, its predicted secondary structure contains eight-stranded β-sheets which may form ``jelly-roll' structure similar to that found in capsid protein encoded by satellite virus of panicum mosaic virus. Received: 26 June 1996 / Accepted: 9 September 1996     

新疆10种沙生植物旱生结构的解剖学研究

新疆１０种沙生植物的形态解剖研究表明,它们为适应沙生环境形态结构发生变化。叶器官的形态呈三种类型：叶片退化成膜质或鳞片状,而由同化枝执行光合功能;叶片上下都具栅栏组织,表皮角质膜厚,表皮毛发达,气孔下陷,输导组织和机械组织都发达;叶片肉质化,叶肉组织不分化,贮水组织发达而输导组织不发达。轴器官中厚壁组织发达,围绕维管组织,维管组织内部也有发达的厚壁组织。根中普遍具有周皮,一些植物存在异常的维管组织,部分植物还具有粘液细胞或结晶。沙生植物形成各种旱生结构,以不同的方式适应沙生环境。