酸敏感离子通道与脑梗死

急性脑梗死约占全部脑卒中的70%,病死率和致残率高,且极易复发。但目前针对急性脑梗死在时间窗内溶栓、抗凝等治疗手段不能从根本上切实有效地修复受损脑组织,且伴有出血等风险。寻找脑梗死形成发展的原因并予以治疗迫在眉睫。酸中毒是引起缺血性脑损伤的重要机制。大量实验研究表明,酸中毒能加重神经元的缺血性损伤,且其梗死面积与酸中毒的程度直接相关。但缺血产生的酸中毒如何引起神经元损伤的确切机制尚不明确。最近研究发现酸中毒能激活一种在中枢及周围神经中广泛存在的膜通道,即酸敏感离子通道,它对Ca2+通透,能引起细胞内Ca2+超载,同时能激活胞内酶引起细胞内蛋白质、脂类及核酸的降解,加重缺血后脑损伤。本文就酸敏感离子通道1a与脑梗死做一综述。     

黑龙江省三江平原丹顶鹤的数量分布

在地面调查的基础上,我们使用Y-11轻型飞机对黑龙江省三江平原地区的丹顶鹤的数量分布近行了调查,调查时飞行高度80米,航速140公里/小时,续航里程共3748公里。调查结果表明,丹顶鹤在三江平原主要分布在8个地区,其中嘟噜河下游、洪河自然保护区、七星河流域和兴凯湖低地是主要繁殖地,总数量共309只。     

Inhibition of gp160 and CD4 maturation in U937 cells after both defective and productive infections by human immunodeficiency virus type 1.

Our results demonstrate that the formation of intracellular complexes between the envelope glycoprotein precursor gp160 of human immunodeficiency virus type 1 and CD4 is a major event, leading to the disappearance of CD4 at the cell surface of infected U937 cells. Using both productively and defectively infected clones of U937 cells, we assessed the effect of CD4-gp160 intracellular association on the maturation of both proteins. Pulse-chase labeling followed by sequential immunoprecipitation was used to analyze the processing of both free and associated CD4 and gp160, and the results showed that the trimming, proteolytic cleavage, and degradation of gp160 were completely abrogated after intracellular binding to CD4. Similarly, the maturation process which normally transforms 80% of CD4 to a partially endoglycosidase H-resistant species was also impaired subsequent to the formation of these complexes. A comparison of gp160 maturation either in free form or as a CD4 complex revealed that neither inefficient transport nor degradation of gp160 can account for the observed blockage of CD4 maturation. Moreover, this impairment was independent of gp120 and gp41, since a defective clone of human immunodeficiency virus type 1-infected cells, unable to cleave gp160, showed binding of CD4 and inhibition of CD4 transport and maturation with the same efficiency as occurred in productively infected cells. Expression of gp160 is thus necessary and sufficient to cause CD4 receptor down-modulation for both productively and defectively infected cells.     

四川省西部鱼类寄生粘孢子虫——1.粘体虫属六新种(粘孢子纲:双壳目)

本文报导四川省西部鱼类寄生粘孢子虫粘体虫属六新种,即异型粘体虫,新种Myxosoma disparis sp.nov.,四川粘体虫,新种Myxosoma sichuanensis sp.nov.,光唇粘体虫,新种Myxosoma acrossochilusi sp.nov.鳅粘体虫,新种Myxosoma nemachilusi sp.nov.斜囊粘体虫,新种Myxosoma obliqua sp.nov.,雅安粘体虫,新种Myxosoma yaanensis sp.nov.。     

Temporal events of gypsy moth vitellogenesis and ovarian development

Abstract The vitellogenic period of gypsy moth ovarian development starts on day 3 of the pupal stage and continues through adulthood. During this period, rapid increases occur in follicle size, protein content, and wet weight of the ovary. Patency is observed on day 3 of the pupal stage.
Pre-vitellogenic follicles are formed in the last larval stadium. Newly formed follicles detach from the germarium on day 4, and increase rapidly to 140 per ovariole at the end of the last larval stadium. The pre-vitellogenic follicles are uniformly around 50 um in diameter. No vitellogenin is incorporated into the oocytes until the pupal stage.
Polyacrylamide gel electrophosesis (PAGE) in the presence of sodium dodecylsulphate (SDS) analysis of male and female haemolymph samples and vitellogenic ovaries demonstrates the presence of two female-specific subunits of vitellogenin of 180 kD and 160 kD. These proteins are detected only in haemolymph and ovarian extracts of vitellogenic females. The molecular weight of the native protein determined by size exclusion chromatography is approximately 400–420 kD.
A highly sensitive double antibody sandwich enzyme-linked immunosorbent assay (ELISA) was developed to monitor the temporal changes in vitellogenin titre in haemolymph. Vitellogenin production starts on day 2 of the last larval stadium, reaching a maximum level by day 6 of the last larval stadium, and decreasing in the late pupal stage as vitellogenin was internalized into the oocytes. This is the first report of vitellogenin production occurring in the larval stage of a holometabolous insect. The fact that vitellogenin production and uptake occur during different stages of development in the gypsy moth, opens up some interesting questions concerning the underlying regulatory mechanisms controlling each process.     

Immunological responsiveness against tumors induced by avian sarcoma virus: reduced expression of pp60src kinase activity in regressing tumors.

Tumors which are induced in chickens by avian sarcoma virus frequently grow progressively for several weeks and then regress. We showed that tumor cells which are derived from the progressively growing phase of tumor growth produce large quantities of progeny-transforming virus, are reactive with antiviral antibody, and are susceptible to lysis in cell-mediated cytotoxicity assays by splenic lymphocytes of sensitized hosts. In contrast, tumor cells derived from regressing sarcomas are poor producers of progeny virus and are relatively unreactive with both antiviral antibody and sensitized lymphocytes. We further found that pp60src kinase activity was reduced by about 75% in regressing compared with progressively growing tumor cells. The half-lives of directly precipitable pp60src in tumor cells derived from progressively growing and regressing neoplasms were 6 and 1.5 h, respectively. Studies on each of three other cellular enzymes did not reveal any regression-associated decreases in enzyme activity. These data support the notion that expression of adequate levels of long-lived pp60src kinase activity is essential to progressive tumor growth.     

云南叶螨属一新种(蜱螨目:叶螨科)

在鉴定云南叶螨标本时,发现叶螨属一新种,现记述如下。模式标本保存于上海农学院。本文量度单位均为微米。 食禾叶螨Tetranychus graminivorus新种(图1—14) 雌螨 体长(包括喙)454,宽298。椭圆形。浅黄绿色。须肢端感器圆柱形,长6.8,