锌和铜在生长抑素对链佐霉素引起的胰岛B细胞损伤的保护中的作用

我们以前的工作指出,生长抑素可以预防链佐霉素对大鼠胰岛B细胞的损伤。本工作测定给药前后大鼠血清和组织中Zn、Cu含量,以进一步观察链佐霉素破坏大鼠胰岛B细胞后生长抑素预防效应的可能机制。结果为:链佐霉素(STZ)(35mg/kg,ip)注射后24h的大鼠,血清Zn浓度下降,Cu浓度升高,Zn/Cu比值倒置;用生长抑素作预防性注射后,血清Zn浓度与正常对照水平相同,Cu浓度虽稍有升高,但Zn/Cu比值正常。保护组的血清Zn与损伤组比较,差异极为显著。两组的Zn/Cu比值同样也具有显著差异。在给药后72h,血清Zn/Cu比值在各组之间仍呈上述关系,但差异减小。在大鼠胰腺,注射链佐霉素后胰腺组织Zn浓度未见改变,但生长抑素作预防性注射可使组织锌含量增加。上述结果提示,在生长抑素对胰岛B细胞的保护机制中可能有Zn和Cu的参与。预防性注射生长抑素所引起的高Zn状态可能有利于机体细胞含Zn酶类的活性,增强已损伤细胞的修复。     

冷杉蒸腾速率及其与生态因子的相关分析

滇西北亚高山地带20年生长苞冷杉（Abies georgei)的蒸腾速率,一年中由低至高,7月份达最大值（195．88mgH2/g.h),尔后下降,蒸腾速率的日进程为午休型,呈双峰曲线变化,蒸腾速率与气温,叶温和光强为正相关,与相对湿度为负相关,冷杉蒸腾速率随海拔增高而降低,高海拔处冷杉蒸腾速率的日进程波动也较小,海拔相同时,迹地上生长的冷杉蒸腾速率比林地内的高,前者为186．15mgH2O/g.h,后者则为123．97mgH2O/g.h。     

不同动物制备的抗血清对病毒抗原免疫反应的差异

血清学技术是病毒诊断、鉴定、分类及亲缘关系分析的重要手段。一般常用以制备抗病毒血清的动物是家兔,但也有采用其它动物的,如蛙、羊、豚鼠、鸡及小鼠等。本文比较了Balb/c小鼠、昆明种小鼠和新西兰大白兔对长叶车前花叶病毒上海分离株(RMVsh)和烟草花叶病毒普通株(TMVc)的免疫反应特征。     

单克隆抗体亲和层析纯化长叶车前花叶病毒

长叶车前花叶病毒上海分离株(HRVsh)单克隆抗体1H2,经纯化后以溴化氰活化法偶联于Sepharose 4B上制成亲和层析柱。HRVsh感染的三生烟提取液,经一次聚乙二醇沉淀初步纯化,悬浮液上亲和层析柱,于磷酸缓冲液中吸附,蒸馏水洗脱。收集的病毒制剂接种心叶烟有感染性,电镜观察见典型的HRVsh粒子,紫外吸收光谱与常规方法提纯的病毒相似,SDS-聚丙烯酰胺凝胶电泳呈一条带。结果表明单克隆抗体亲和层忻得到高度纯化的HRVsh。最后讨论了单克隆抗体亲和层析方法的优点。     

白萝卜提取物诱生干扰素的有效成份

本实验用CF-11纤维素柱层析,从白萝卜提取物中分离纯化到一种双链RNA,简称E.R.s.r-dsRNA(全称见正文)。实验证明,E.R.s.r-dsRNA在家兔体内可诱生高水平的干扰素;纳克(ng)水平即可在体外细胞培养中抑制病毒感染。E.R.s.r-dsRNA分子量略小于1.34×10~6道尔顿,它对RNase的耐受性比Poly Ⅰ:PolyC强。推测E.R.s.r-dsRNA可能有较好的应用前景。     

连续注射抗菌i-RNA诱生内源性细胞毒因子的研究

应用抗菌免疫核糖核酸(i-RNA)对家兔进行连续致敏注射和诱生注射,结果证明在家兔血清中有抑制和杀伤靶细胞(L929)作用较强的细胞毒因子出现。实验对i-RNA诱生内源性细胞毒因子的动态、不同i-RNA的诱生效果,对人和鼠的某些瘤细胞毒作用等做了初步研究,对内源性细胞毒因子的作用主要来自TNF的活性也做了讨论。     

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。     

NMDA受体在海马CA3区习得性TP保持中的作用

The effect of microinjection of 2-amino-5-phosphonovaleric acid (APV), a selective NMDA receptor antagonist, into the rat hippocampal CA3 area on the synaptic efficacy and related conditioned behavior during the acquisition and consolidation of discrimination learning behavior was examined. The results showed: (1) After population spike (PS) amplitude had just increased to the maximum through training i.e. learning-dependent LTP had just formed, APV 1 microliter (2 mmol/L) was injected into CA3 area, then the rats were trained during the time of efficacy of the drug in every experimental block. The result demonstrated that the PS amplitude could not be maintained at the highest level but decreased to the pre-experiment level after 8 blocks. Correct response percentage of rats could not be consolidated with further training but decreased to less than 10%. (2) After the PS amplitude had kept up at the highest level, APV 1 microliter (2 mmol/L) was injected into CA3 area, then the rats were trained during the time of efficacy of the drug in every experimental block, in which case the PS amplitude also could not be maintained at the highest level but decreased to the pre-experiment level after 14 blocks. Correlatively, when the correct response percentage of rats decreased gradually to less than 10%, the conditioned response of the animals extinguished, but its extinction speed was slower than it was in result (1). These results suggest that the NMDA receptor in CA3 area plays an important role in the maintenance of the learning-dependent long-term potentiation.     

NMDA受体在海马CA_3区习得性LTP保持中的作用

在大鼠明暗分辨学习的建立和巩固过程中,通过与记录电极一起慢性埋植于海马CA_3区的注药管微量注射NMDA受体的特异性拮抗剂2-amino-5-phosphonovaleric acid(APV),观察对海马CA_3区突触效应及与之相关的习得性行为的影响。结果如下:(1)在动物经训练PS峰幅值刚增大至最高水平后,即在习得性LTP刚好形成后,每实验单元先于CA_3区注射AFV 1μl(2mmol/L),然后在药物有效作用时间内再进行训练,则PS峰值不能随训练而保持在最高水平,相反经8个实验单元,PS峰值降至实验前水平;相应地动物的正确反应率不能随训练而巩固,反而下降至10％以下。(2)在动物习得性LTP已形成并经一单元训练PS保持在最高水平后,于每实验单元训练前注射APV 1μl(2mmol/L),PS峰值同样不会随训练而保持在最高水平,经14个实验单元注药和训练,PS峰值逐渐降至实验前水平,相应地动物行为的正确反应率也降至10％以下,习得性行为消退,不过其消退速度比前一情况的动物为慢,说明习得性LTP发展情况不同,APV的作用效率有差别。结果表明:NMDA受体在习得性LTP的巩固中起着重要作用。     

芦苇苗期高粱长蝽若虫空间分布型及抽样技术

<正> 高梁长蝽Dimorphopterus spinolae(Si-gnoret)是湘鄂两省湖区重要的芦苇害虫,以芦苇苗期受害最烈,长势衰弱,枯黄死亡,对苇株生长和产量都有严重影响。空间分布型可以