P物质在家兔延髓腹侧面加压区的升压作用及其机制探讨

在乌拉坦麻醉，三碘季铵酚制动，人工呼吸的家兔上观察到，延髓腹侧面加压区给予Ｐ物质使血压呈剂量依赖性升高，但对心率无明显影响。ＶＳＭｐ给予ＳＰ受体阻断使ＢＰ明显降低并可阻断ＳＰ升压效应，ＶＳＭｐ给予酚妥拉明或哌唑嗪预处理使ＳＰ升压效应减弱或消失，而给予育亨宾或心得安对ＳＰ升压效应无明显影响。ＶＳＭｐ给予ＳＰ可使肾交感神经放电显著增加，并伴有ＢＰ显著升高；ＶＳＭｐ给予ＤＳＰ使ＲＳＮＤ和ＢＰ明显降低并可     

Comparison of tissue-cultured bovine endothelial cells from aorta and saphenous vein

Endothelial cells were harvested from bovine aorta and saphenous vein with collagenase and cultured in McCoy's 5a medium (modified GIBCO) supplemented with 10% fetal bovine serum. The cells were subcultured through 17 passages over 4 to 5 months. The growth properties in culture of the two cell types were compared. Morphological comparisons included phase microscopy and scanning and transmission electron microscopy. Comparisons with cultured aortic smooth-muscle cells were made using phase and scanning electron microscopy. No differences were found between cultured endothelial cells from aorta and saphenous vein. Differences in growth patterns in culture clearly distinguished both endothelial cell types from smooth-muscle cells. The presence of Weibel-Palade bodies identified the cells from both sources as endothelial.     

Mapping of C2, Bf, and C4 genes to the swine major histocompatibility complex (swine leukocyte antigen)

Three miniature swine lines, inbred for swine leukocyte antigen (SLA) haplotypes, a, c, and d, and a recombinant line, haplotype g, were analyzed for possible restriction fragment length polymorphisms (RFLP) by Southern blot hybridization with human C2, factor B (Bf), and C4 specific probes. The search for RFLP by using a human C2 probe failed to reveal any variants. However, a Taq I polymorphism was identified with the human Bf probe and Bam HI and Pvu II polymorphisms were identified with the human C4 probe. Overlapping restriction fragments were found with the C2 and Bf probes, which strongly suggests close linkage of C2 and Bf genes in swine. Segregation analyses of the Bf and C4 polymorphisms indicated that the polymorphic fragments followed a Mendelian pattern of inheritance. The recombinant haplotype g, which expresses class I genes of haplotype c and class II genes of haplotype d, was shown to produce an identical RFLP pattern, by using the Bf and C4 probes, as haplotype d, but different from that of haplotype c. This indicates that there is a close association of [C4-Bf-C2] and class II genes in miniature swine. Although these data do not show conclusively the location of the [C4-Bf-C2] genes, it is hypothesized that swine [C4-Bf-C2] genes are located between the class II and class I genes, as has been demonstrated in mouse and man.     

血管内皮舒张因子在氧自由基所致慢性缺氧大鼠肺内动脉收缩中的作用

以黄嘌岭(X)-黄嘌呤氧化酶(XO)系统产生氧自由基,应用微量生物测定法观察慢性缺氧(5000m,10d)对大鼠氧自由基所致肺内动脉收缩的影响及内皮舒张因子(EDRF)在其中的作用。慢性缺氧大鼠有内皮的肺内动脉环对氧自由基的收缩反应较正常环境中的对照动物明显增强,加入EDRF灭活剂还原型血红蛋白(RHb)后更加显著;而加入超氧化物歧化酶(铜锌SOD)后则减弱,甚至消除。反之,不论加入RHb或SOD对氧自由基所致去内皮肺内动脉环的收缩反应均无明显影响。上述结果表明慢性缺氧引起肺内动脉收缩增强与EDRF有密切关系:慢性缺氧可能使EDRF的作用减弱,肺内动脉对氧自由基的反应性增强。表示EDRF及其与氧自由基的关系在慢性缺氧性肺动脉高压的形成中可能具有十分重要的意义。     

Nodulation of lucerne (Medicago sativa L.) in an acid soil: Effects of inoculum size and lime-pelleting

The effects of inoculum level and lime-pelleting were studied in an acid soil with respect to the nodulation and growth of lucerne (Medicago sativa cv Resis) and the population dynamics of Rhizobium meliloti. In small root-boxes (rhizotrons), the in-situ survival of inoculated rhizobia was studied in the micro-environment around the seed for a period of 12 days after sowing. During the initial 24 hours, a strong increase in rhizobial numbers was measured, concomitantly with the development of roots. As a result of lime-pelleting, rhizobial numbers were higher only at 3 days after sowing (P<0.05). Later, this difference diminished steadily. Addition of lime did not increase the adhesion of the rhizobia to the seedling tap root. Plant responses to inoculation were studied in pots. To obtain optimal nodulation, the soil had to be neutralized around the seed with lime and at least 10⁵ cells of R. meliloti were required. With more than 10⁵ rhizobia per seed, lime-pelleting increased the number of crown-nodulated seedlings from 24% to 77%. Higher numbers of rhizobia could not compensate the effect of lime. A strong correlation was found between crown nodulation, nitrogen content and dry weight of the shoots.     

青海省海北地区高寒草甸鸟类群落结构的季节变化

本研究地区,高寒草甸鸟类群落由22种鸟组成,它们隶属于2目9科,其中留鸟11种,迁徙鸟8种。在当地繁殖的鸟19种,冬候鸟2种。各项鸟类群落指标呈现明显季节变化,一般从早春开始上升,到夏季达到高峰,然后逐渐下降至隆冬的最低点。     

悼念李世英教授

中国植物生态学与地植物学家,中国植物学会理事,《植物生态学与地植物学学报》常务编委,中国科学院植物研究所研究员李世英同志,因患鼻咽癌,经多方长期治疗无效,于1985年12月17日零点在北京逝世,终年64岁。李世英同志1945年毕业于前中央大学。研究生肄业后,就职于前巾央林业实验所,从     

促生长素抑制素样免疫反应在大白鼠弓状核和正中隆起的超微结构分布

本文用免疫电镜方法证明:促生长素抑制素样免疫反应神经末梢分布于弓状棱并与未标记的树突形成轴树突触。在正中隆起的纤维层和栅状层内均可见上述免疫反应末梢,大多数紧贴门脉毛细血管基底膜周围甚至穿入基底膜内。免疫反应末梢尚可与未标记的末梢形成轴轴突触样结构。