动物性饲料中沙门氏菌的快速鉴别

沙门氏菌属是饲料中污染最高、危害最大的病原性细菌,此菌属种多,分布广,已知的血清型株有2449种。沙门氏菌对人和动物有致病力,如伤寒沙门氏菌、副伤寒沙门氏菌等,动物通过饲料摄人大量菌体后,细菌在肠道繁殖并产生内毒素,对肠道产生刺激作用,引起严重的胃肠炎症状。该菌能引起动物的多种疾病,如禽霍乱、鸡白痢、马流产等,并造成沙门氏菌的传播循环即：饲料一动物一食品原料一人。饲料原料被沙门氏菌污染是造成饲料产品沙门氏菌污染的主要途径,因此国家农业部饲料中心把沙门氏菌的检测作为饲料原料抽检的必检的卫生指标之一。然而饲料中沙门氏菌的检验采用国标方法则相当复杂。为了探索更准确、快捷的检验方法,我们分别采用国标方法和参照法国生物梅里埃公司AOAC食品中沙门氏菌属的生物化学工具鉴定法进行。     

Study on Expression of Bcl-2 and PCNA Genes in Testicular Tissue of Chickens,Quails and Chicken-quail Hybrids

In order to investigate the molecular mechanism of stunted growth testis of chicken (♂) and quail (♀) hybrids. 84 testicular tissue samples of New Roman cocks, male Korean quails and chicken-quail hybrids at different developmental stages were collected,the mRNA expression of Bcl-2 and PCNA genes in testicular tissue of cocks, quails and chicken-quail hybrids at different growth stages were detected using Real-time PCR. The results showed that the Bcl-2 and PCNA genes mRNA expression patterns in testes of chickens and quails at different growth stages were similar.The Bcl-2 gene was fluctuated in a whole, and decreased to the lowest value, then recovered rapidly and remained at a high level. The PCNA gene had a very significant peak value.Compared with the chicken and quail,the expression of Bcl-2 and PCNA genes mRNA in hybrids had no obvious change, which indicated that the pattern of the Bcl-2 gene regulation apoptosis in testis was different from chicken and quail at the hybrid testicular development process, and there was no obvious cell appreciation process.It was suggested that the molecular influencing factors of testicular dysplasia of chicken and quail hybrids were related to the abnormal expression of Bcl-2 and PCNA genes mRNA in testes.The results provided an important reference for the further study of the mechanism of testicular dysplasia between chicken and quail interspecific hybrids.     

超微粉碎对菌草鹿角灵芝中多糖、三萜类溶出度的影响

目的:比较不同浸提时间菌草鹿角灵芝超微粉和普通粉中多糖和三萜类溶出率的差异。方法:采用苯酚-硫酸法检测多糖含量,以齐墩果酸为标准品,采用紫外-可见分光光度法检测三萜类含量。结果:相同提取时间下,超微粉多糖和三萜类的溶出量分别比细粉的溶出量提高24%和15.2%,溶出度参数T50和Td检测结果显示,超微粉多糖、三萜类溶出速度也比细粉快,在90 min时超微粉多糖累计溶出量达到95%以上,三萜类在90%以上,而细粉的两项溶出量均仅为约70%。结论:超微粉碎技术有利于菌草鹿角灵芝有效成分的溶出。     

日粮中缺硒对鸡空肠肥大细胞组织化学和超微结构的影响

为探讨硒缺乏对鸡空肠中肥大细胞(MC)的形态学和超微结构的影响,将10只鸡随机分成低硒试验组(饲喂低硒日粮0.032 mg/kg)和正常对照组,在75日龄时断头处死立即取出空肠,进行甲苯胺蓝、长时间甲苯胺蓝、阿利新蓝-藏花红染色、阿利新蓝-高碘雪夫氏反应和醛品红-阿利新蓝5种染色并进行透射电镜观察.结果显示,采用不同染色方法所获得的MC数量、大小、形态、颜色及颗粒的黏多糖成分均不相同.电镜下,MC细胞胞浆内充盈大量的特征性颗粒,颗粒内容物呈均质状,电子密度高低不等,核圆形或椭圆形,胞质中可见高尔基复合体和较多的线粒体;试验组可见MC数量显著增加并与变性细胞紧密相邻,异染色质增多,核偏位或固缩,胞质稀疏,同时可见MC内颗粒内容物释放后的空隙或空泡.因此,组化染色提示肥大细胞存在不同亚型;试验组MC数量明显增加,这提示MC是重要的免疫细胞之一,在机体的免疫调节中发挥着重要的作用.     

Separating component parts of soil respiration under <Emphasis Type="Italic">Robinia pseudoacacia</Emphasis> plantation in the Taihang Mountains,China

Partitioning the respiratory components of soil surface CO₂ efflux is important in understanding carbon turnover and in identifying the soil carbon sink/source function in response to land-use change. The sensitivities of soil respiration components on changing climate patterns are currently not fully understood. We used trench and isotopic methods to separate total soil respiration into autotrophic (R _A ) and heterotrophic components (R _H ). This study was undertaken on a Robinia pseudoacacia L. plantation in the southern Taihang Mountains, China. The fractionation of soil ¹³CO₂ was analyzed by comparing the δ¹³C of soil CO₂ extracted from buried steel tubes with results from Gas Vapor Probe Kits at a depth of 50 cm at the preliminary test (2.03‰). The results showed that the contribution of autotrophic respiration (fR _A ) increased with increasing soil depth. The contribution of heterotrophic respiration (fR _H ) declined with increasing soil depth. The contribution of autotrophic respiration was similar whether estimated by the trench method (fR _A , 23.50%) or by the isotopic method in which a difference in value of ¹³C between soil and plant prevailed in the natural state (RC, 21.03%). The experimental error produced by the trench method was insignificant as compared with that produced by the isotopic method, providing a technical basis for further investigations.     

半干旱地区禾-豆混播草地生物固氮作用研究

 本研究以羊草－沙打旺、羊草－兴安胡枝子、羊草－ 花苜蓿和羊草－ 紫花苜蓿混播草地为对象,比较４种豆科牧草在松嫩平原半干旱地区的生物固氮能力、氮素转移能力以及生物固氮量对草地氮产量的贡献。结果表明,羊草－沙打旺、羊草－紫花苜蓿混播草地氮产量显著高于单播羊草草地,草地粗蛋白含量的增加显著改善了草地质量。沙打旺、兴安胡枝子、花苜蓿和紫花苜蓿生物固氮率为３５％～４０％,大气氮是豆科牧草生长不可缺少的氮素来源。豆科牧草向羊草转移氮素２～１２ｋｇＮ／（ｈｍ^２·ａ）,占羊草氮产量的５％ ～２４％。豆科植物的固氮能力增加了草地氮素资源,沙打旺、兴安胡枝子、花苜蓿和紫花苜蓿生物固氮量分别占其混播草地总氮产量的２０．３０％,１７．７８％,１１．２９％和３１．７７％。     

铅对昆明小鼠肾脏毒性的病理学观察

采用醋酸铅灌胃于成年昆明小鼠,观察铅致小鼠肾脏的病理形态变化。取小鼠分为4组,分别为醋酸铅高、中、低剂量组(40、20、10mg/kg)、生理盐水阴性对照组,经口灌胃每天定时定量连续给药40d。取小鼠肾脏经甲醛固定,常规石蜡包埋切片,HE染色,显微镜下观察小鼠肾脏的组织形态。结果表明,各试验组肾皮质部小管上皮细胞肿胀,胞质疏松,染色浅,空泡变性,发生广泛性颗粒变性,部分肾小管上皮细胞嗜酸性坏死;高剂量组肾皮质部肾小管周围大量淋巴细胞浸润,肾小管上皮细胞表现明显的颗粒变性和嗜酸性坏死,肾小球体积萎缩,结构破坏,出现局灶性硬化;部分肾小管管腔内可见嗜酸性凝固物,肾小球毛细血管扩张充血;中剂量组病变相对较轻;而低剂量组无明显形态学异常。结果提示铅对小鼠肾脏有毒性作用,且随剂量增加损伤加重。     

青海省"西繁东育"工程经济、生态效益核算

针对农民关心的经济收益问题,核算了"西繁东育"的经济收入;同时,参考Robert Costanza对全球自然生态系统服务价值的核算以及谢高地等对中国草地生态系统服务价值和青藏高原生态资产价值的评估,对"西繁东育"工程带来的生态效益进行估算.藏系绵羊羔羊、淘汰母羊和牦牛牛犊西繁东育为农民带来的经济收益分别为38.98,47.12元/只和212.6元/头,而因此产生的生态效益价值高达5 301.85元/个羊单位和15 953.31元/头,在青海实施"西繁东育"不仅可以增加农民经济收入,提高牧户抗灾保畜能力,因此而产生的生态效益也非常可观.     

鸡传染性支气管炎病毒广西流行株3种主要结构蛋白基因的遗传变异分析

为了解鸡传染性支气管炎病毒(IBV)广西流行株的遗传变异情况,应用RT-PCR方法对2004-2007年的7株广西IBV分离株的纤突蛋白S1基因、核(N)蛋白和膜(M)蛋白基因进行扩增、克隆、测序和同源性比较及系统进化分析。结果显示广西IBV分离株S1基因存在广泛的基因点突变,部分毒株出现基因插入和缺失,分离株之间氨基酸同源性为74.2%～98.7%;N基因无插入和缺失,但存在基因点突变,分离株之间氨基酸同源性为91.7%～99.3%;M基因存在点突变和插入现象,分离株之间氨基酸同源性为90.7%～98.2%。以疫苗株H120为参照,广西IBV分离株的S1、N和M基因都出现了变异,其中S1基因变异程度最大。7株广西IBV在S1、N和M基因氨基酸序列系统进化树中分别集中在2、3和3个基因群中,其中4株的S1、N和M基因分型结果不一致。结果表明广西IBV分离株的S1、N和M基因已发生变异,广西IBV存在广泛的基因突变、缺失或插入现象。研究的结果提示流行株的遗传变异可能是目前影响疫苗免疫效果的主要原因。     

胆翘注射液急性和亚慢性毒性试验

旨在评价胆翘注射液的毒性,为临床安全用药提供理论依据。以昆明小鼠为研究对象,进行急性和亚慢性毒性试验。在急性毒性试验中,给予小鼠不同浓度的胆翘注射液来测定胆翘注射液的半数致死量和最大耐受量;在亚慢性毒性试验中,小鼠以(10、5、2.5g/kg)不同剂量连续腹腔注射给药28d,在给药第28天观察小鼠的临床体征、体重及饲料利用率、血常规、血液生化指标和病理组织学变化。结果显示,急性毒性试验各剂量组小鼠均无死亡,无法测出LD_(50),最大耐受量为20g/kg。亚慢性毒性试验中用药组小鼠的临床体征、体重及饲料利用率、血常规、血液生化指标与空白组小鼠相比,无显著差异(P0.05),组织病理学观察,实质器官无异常病变。表明胆翘注射液实际无毒,安全性好。