大豆低聚糖对牙鲆营养效应的研究：Ⅱ 消化率和消化生理

本试验比较研究了不同蛋白源(鱼粉,FM;大豆分离蛋白,SPI)基础饲料中添加大豆低聚糖(SBOS)对牙鲆(Paralichthys olivaceus)消化道(胃、幽门盲囊、前肠、中肠和后肠)和肝脏消化酶活性、饲料表观消化率和消化道(胃、小肠)组织结构的影响。分别以FM、SPI作为主要蛋白源,配制了4种等氮等能饲料。其中,饲料FM、SPI分别以FM、SPI作为主要蛋白源;饲料FMO、SPIO分别在饲料FM、SPI基础上添加10%SBOS(水苏糖：2.61%;棉籽糖：0.61%)。试验表明：①饲料中添加SBOS普遍降低了牙鲆消化道和肝脏蛋白酶活性,但差异均不显著(p > 0.05)。FM基础饲料中添加SBOS显著降低了肝脏脂肪酶活性(p < 0.05),而对消化道脂肪酶活性无显著影响;SPI基础饲料中添加SBOS显著提高了前肠脂肪酶活性,降低了胃和中肠脂肪酶的活性,而对幽门盲囊、后肠和肝脏脂肪酶活性均无显著影响。FM基础饲料中添加SBOS显著降低了中肠淀粉酶活性,提高了胃淀粉酶活性(p < 0.05),而对幽门盲囊、前肠、后肠和肝脏淀粉酶活性无显著影响;SPI基础饲料中添加SBOS显著提高了胃和前肠淀粉酶活性,降低了中肠脂肪酶活性(p < 0.05),而对幽门盲囊、后肠和肝脏淀粉酶活性无显著影响;②FM基础饲料中添加SBOS显著降低了饲料干物质表观消化率(p < 0.05),而对粗蛋白、粗脂肪和能量表观消化率均无显著影响(p > 0.05)。SPI基础饲料中添加SBOS对干物质、粗蛋白、粗脂肪和能量表观消化率均无显著影响;③饲料中添加SBOS对牙鲆胃和小肠组织结构均无明显负面影响。试验结果表明,饲料中添加SBOS对牙鲆消化道和肝脏消化酶活性、饲料表观消化率和消化道组织结构均没有表现出明显的负面效应;大豆蛋白源中含有的SBOS不是影响牙鲆对其利用率差的主要因素。     

Degradation of CCK-8 by rat synaptosomal peptidases

By use of an antiserum raised against conjugated ovine corticotropin releasing factor (CRF_1–41), nerve fibres can be stained immunocytochemically in the external zone of the median eminence of rats. The presence of CRF-immunoreactive (CRF_i) nerve fibres and the plasma corticosterone response to ether stress were studied in rats 6–7 days after making various types of lesions in the hypothalamus. Complete anterolateral deafferentation of the mediobasal hypothalamus caused complete disappearance of CRF_i fibres from the median eminence and blocked the corticosterone response to stress. Incomplete anterolateral hypothalamic deafferentation did not prevent the stress-induced increase of corticosterone and in these rats, part of the CRF_i nerve fibres remained intact. A horizontal cut placed ventral to the paraventricular nuclei, completely prevented the corticosterone response in those rats that showed a complete disappearance of CRF_i nerve fibres from the median eminence. Some rats however, still exhibited CRF_i nerve fibres and these animals responded to stress with increased corticosterone levels. A similar horizontal cut made just dorsal to the paraventricular nuclei affected neither the corticosterone response to stress nor the appearance of CRF_i nerve fibres in the median eminence. We conclude that the presence of CRF_i nerve fibres in the median eminence is a prerequisite for rats to show a pituitary-adrenal response to ether stress and therefore represents the first functional evidence for the role of these hypothalamic CRF_i-neurons.     

基因转移治疗血友病B的动物试验和安全性探讨

本文报道了皮肤成纤维细胞基因治疗血友病Ｂ的新西兰大白兔试验及安全性检测。转有人凝血因子ＩＸｃＤＮＡ的兔皮肤成纤维细胞包埋于胶原基质中,然后进行不同方式的自体或同种异体移植,移植兔血浆中人ＩＸ因子蛋白有高水平的表达且持续稳定,腹腔移植有ＲＳＦ－ｐＣＭＶＩＸ转化细胞的兔血浆中人ＩＸ因子表达水平达１００ｎｇ／ｍｌ．持续５个月以上,腹腔移植有ＲＳＦ－ｐＣＭＶＩＸｌ转化细胞的兔血中人ＩＸ因子表达水平达２９５     

猪水肿病大肠杆菌志贺样毒素Ⅱ型突变体新基因的分子特征

从仔猪水肿病样品中分离的一株大肠杆菌菌株NP9621,抽提染色体DNA,构建NP9621的总DNA文库,经菌落原位杂交筛选、限制酶酶切和Southern印迹等分析,获得含有志贺样毒素基因的重组质粒,核苷酸序列分析表明, 该基因的 A亚基与SLTIIes的同源性为97.6%～98.1%,与SLTIIc、SLTIId及EHEC O157:H7产生的SLTII 的A亚基之间的同源性分别为93.1%、93.0%和92.9%;B亚基与SLTIIes的同源性为99.62%～100%,与SLTIic、SLTIid及SLTII的同源性分别为81.5%、81.1%和81.5%;与29种已知序列的SLTII 、SLTI及志贺毒素STX进行聚类分析,结果证实大肠杆菌NP9621菌株中的志贺样毒素基因属于一种新的SLTIIe亚型。SLTIie/NP9621的A亚基与其它SLTIIe之间存在7～9个氨基酸的差异,B亚基的氨基酸序列完全相同,与A亚基毒力活性密切相关的氨基酸分别为Thr4、Glu167、Arg170和Arg176。     

克仑特罗对绵羊肝脏血液中IGF-Ⅰ、GH和胰岛素水平的影响

克仑特罗 (ｃｌｅｎｂｕｔｅｒｏｌ ,ＣＬ)为一种 β -肾上腺素能受体激动剂。自 80年代初发现 β -受体激动剂可促进机体生长并改变机体胴体组成以来 ,许多研究均显示 β -激动剂具促进脂肪动员、减少体脂沉积、增加氮素贮存和促进蛋白质合成等作用 ,进而调节机体的生长发育 ,因而 β -激动剂又被称为“营养分重分配剂” (Ｙａｎｇ＆ＭｃＥｌｌｉｇｏｔｔ ,1989;Ｃａｒｄｏｓｏ＆Ｓｔｏｃｋ ,1996;Ｓｍｉｔｈ ,1998)。然而机体内代谢水平在很大程度上受内分泌的调控。在对影响机体生长发育的内分泌研究中 ,越来越多的证据表明胰岛素样生长…     

一株海洋放线菌的分离鉴定及活性研究

从大连海域20~30 m深处生长的海绵中分离到一株有很高抗菌活性的链霉菌D164。根据培养和显微形态、生理生化数据、16S rRNA基因序列数据分析,菌株D164鉴定为娄彻氏链霉菌(Streptomyces rochei)。对菌株D164发酵产物进行抗农业病原菌、杀虫和除草活性检测,结果表明,菌株D164发酵产物具有很高的抗农业病原菌活性,同时又具有很高的杀虫和除草活性,其活性化合物值得进一步研究。     

Diversity and Community Quantitative Characteristics ofFloor Lichen in Yaoluoping National NatureReserve of Anhui,China

Twenty nine quadrats belonging to various habitats were sampled in Yaoluoping National Nature Reserve, lichen species in each quadrat were identified and the lichen coverage of each quadrat was measured, combined with several environmental indices, with the purpose of understanding the lichen distributing pattern and community quantitative characteristics. Factor analysis was used to appraise relationships among ecological factors, cluster analysis and Spearman rank correlation coefficient test were employed for ordination and Fisher’s exact test was applied to evaluate interspecific correlation. Factor analysis showed that the number of species decreased as the altitude increased, and there was significant positive correlation between dominant species quantity and coverage (P=0.034), very significant positive correlation between humidity and habitat type (P=0.001). Based on cluster analysis data, twenty nine quadrats were divided into 5 types of association. Fisher’s exact test indicates 10 species pairs were very significant positive association and four species pairs significant positive, but no species pair was negative significant association. Fisher’s exact test demonstrated that the competition between the species was low.     

湖羊6号染色体微卫星标记多样性与产羔数的关系

选择位于绵羊6号染色体上FecB基因紧密连锁的6个微卫星标记, 即LSCV043、BMS2508、GC101、300U、Bulge5和471U, 分析其在湖羊中的遗传多样性以及和产羔数的关系。结果表明, 6个微卫星位点均属多态性位点, 共检测到34个等位基因、53种基因型。LSCV043、BMS2508和300U属高度多态位点, 其多态信息含量分别为0.6674、0.6035和0.5615。对不同基因型群体的产羔率进行统计分析, LSCV043基因型为107 bp/123 bp所对应的总体产羔数明显高于110 bp/123 bp基因型群体所对应的产羔数(P<0.05); BMS2508基因型为154 bp/154 bp、154 bp/170 bp和154 bp/200 bp所对应的群体第一胎产羔数明显高于170 bp/170 bp所对应的产羔数(P<0.05), 基因型170 bp/170 bp的群体总体产羔数均低于该位点的其他基因型(P<0.05); 其他位点各基因型之间产羔数均无显著差异。