Estrogenic activity of o,p'-DDT in the mammalian uterus and avian oviduct

When rats and birds were treated with o, p-DDT, their reproductive tissues exhibited the same response as when they were treated with estrogen. Weight, water content, glycogen, and RNA increased in uteri and oviducts of rats, chickens, and quail receiving o, p-DDT; p, p-DDT produced little if any response. The o, p-DDT did not accumulate in the reproductive or adipose tissues to a greater extent than p, p-DDT.     

Avian thyroid: effect of p,p'-DDT on size and activity

Feeding sublethal amounts of p,p'-DDT to pigeons caused an increase in thyroid weight and a reduction in colloid content of the follicles. This may reflect a hyper- or hypo-functioning gland and may be cotnnected with recent reductions in egg shell weights in wild birds. The effect was accompanied by increased liver weight.     

p,p'-DDT: effect on calcium metabolism and concentration of estradiol in the blood

Ringdoves given 10 parts per million p,p'-DDT showed a decrease of estradiol in the blood early in the breeding cycle and egg-laying was delayed. There was also a decrease in deposition of medullary calcium and in eggshell weight. Injection of p,p'-DDE (150 milligrams per kilogram of body weight) caused reduction of eggshell weight and inhibition of carbonic anhydrase in the oviduct.     

Microsomal hydroxylase induction in liver cell culture by phenobarbital, polycyclic hydrocarbons, and p,p'-DDT

Aryl hydrocarbon hydroxylase induction by phenobarbital, polycyclic hydrocarbons, and the insecticide, 2.2-bis(p-chlorophenyl)-1,1,1-trichloroethane (p,p'-DDT), occurs in rat fetal liver cell cultures. The maximum net rate at which the hydroxylase activity accumulates is about the same when phenobarbital, 3-methlcholanthrene, or benz[a]anthracene is in the growth medium at optimum concentrations. An additive effect is obtained when either phenobarbital or p.p'-DDT is present with a polycyclic hydrocarbon in the growth medium, but not when the cells are treated with phenobarbital plus p.p'-DDT or with the combination of two polycyclic hydrocarbons.     

环境雌激素E2、o,p′-DDT和抗雌激素TAM对斑马鱼(Danio rerio)胚胎的二元联合毒性效应

为了探究雌激素与抗雌激素类化合物的联合毒性效应,将斑马鱼胚胎暴露于雌激素17β-雌二醇(E2)和o,p′-DDT,抗雌激素它莫昔芬(TAM)以及雌激素(E2、DDT)与抗雌激素(TAM)的二元混合物96 h,观察其形态学变化(孵化率、畸形率和孵化时间)以及测定雌激素效应相关基因(VTG1,VTG2和ERα)的转录水平。结果显示,暴露于E2 (0.25 μg/L),o,p′-DDT (100 μg/L)与TAM (10,0,250 μg/L)的二元混合物组可致斑马鱼的畸形率上升、孵化率下降、孵化时间延长,混合暴露组与单独暴露组差异显著(P<0.05)。例如当E2浓度为0.25 μg/L,TAM浓度为50 μg/L,混合暴露组孵化率为57.2%,显著低于单独暴露于E2的82.5%以及单独暴露于TAM的90.4%。在胚胎发育形态学水平上,未观察到二元混合物组繁殖毒性明显减低的现象;在基因转录水平上,TAM对雌激素并不是单纯的拮抗作用,其作用随暴露浓度不同而有所改变。实验表明,抗雌激素TAM与雌激素E2及DDT的混合暴露提高了对斑马鱼的毒害作用。     

p，p′-DDT在黄河兰州段沉积物上的吸附/解吸特性及影响因素研究

采用批量平衡实验,研究了黄河兰州段沉积物对p,p′-DDT的吸附/解吸特性,并考察了环境因素温度、pH值、沉积物粒度等对吸附的影响。结果表明,p,p′-DDT在黄河兰州段沉积物上的吸附在24h内可以充分达到平衡。吸附过程是非线性的,Freundlich模型可以较好地描述吸附行为,分配作用和表面吸附作用同时存在;解吸过程存在明显滞后性,即解吸要比吸附困难。正交结果表明吸附质浓度和吸附剂浓度对p,p′-DDT在沉积物上的吸附量有显著影响,而温度、pH值、有机质含量、沉积物粒度影响不显著。     

葱蝇非滞育蛹期的发育形态学研究

葱蝇是昆虫蛹滞育研究的理想模式种,其发育形态学特征对推断滞育发育过程至关重要,目前还没有花蝇科蛹期发育形态学的相关报道.本研究通过解剖和拍照观察,系统地研究了葱蝇老熟幼虫期到羽化的发育形态学特征,特别注重头外翻前后的形态变化.研究结果将老熟幼虫期划分为5个发育阶段;将预蛹期分为白色围蛹期和棕色围蛹期2个亚时期,13个发育阶段;将蛹期分为隐头蛹期和显头蛹期2个亚时期,30个发育阶段.其中,显头蛹期又可细分为显头蛹初期、发育形态停滞期、半透明眼期、浅黄色到琥珀色眼期、红褐色眼期、鬃毛蛹期和预成熟期.本研究还详细地描述了各时期及发育阶段的发育过程、历期和形态特征,并详细地观察和描述了头外翻的发育过程,把蛹壳外可见幼虫口钩确定为头外翻发生的外部标志特征.同时,还描述了蛹主要发育阶段的长宽比例,成熟雌、雄蛹间的形态差异,结果表明雌虫体型(体长和体宽)比雄虫略大,雄虫的复眼比雌虫大,雌虫两复眼间的距离超过雄虫的2倍.本文是花蝇科昆虫蛹期发育形态学的首次报道,对认知蝇类昆虫蛹期发育形态,了解葱蝇滞育与非滞育蛹发育过程、历期和形态变化有重要的意义,为葱蝇滞育的分子机理研究奠定了形态学基础.     

Genetic resistance to aflatoxin in Japanese quail

Progress was rapid in attempts to develop lines of quail resistant to acute aflatoxicosis induced by oral dosing with aflatoxin. After five generations of selection, 8- and 11-fold differences were present in mortality between two selected lines and their respective control lines. These quail lines should be of value in investigating the physiological basis of resistance to aflatoxin.     

Relationship of blood type to histocompatibility in chickens

Evidence shows that the B blood group locus in chickens, which controls red cell antigens, is associated with tolerance of skin homografts. Three other blood group loci studied did not show this effect.     

鸡、鸭和鹅胰腺的比较解剖

本实验用大体解剖学方法,对鸡、鸭、鹅的胰叶和胰管的形态结构进行观察.3种家禽的胰腺均分为背侧胰叶、腹侧胰叶和脾胰叶,除有背侧胰管和腹侧胰管外,并有一小胰管,鸡、鸭、鹅分别自背侧胰叶腹侧、背侧胰叶尾端和腹侧胰叶尾端发出.背侧胰管和腹侧胰管的入肠形式:鸡为背侧胰管在前,腹侧胰管在后.鸭和鹅有3种:背侧胰管和腹侧胰管左、右并列:背侧胰管在前,腹侧胰管在后;腹侧胰管在前,背侧胰管在后.     

清远麻鸡miR-142-3p分析及其关键靶基因的筛选

为分析清远麻鸡不同组织中miR-142-3p的表达情况,并筛选其在脾脏中的关键靶基因,本研究利用在线数据库预测鸡miR-142-3p靶基因,并对靶基因进行GO和KEGG富集分析以及构建蛋白-蛋白互作网络。利用在线公共数据库,分析脾脏相对于其他组织的miR-142-3p表达量;再根据miRNA表达量与其靶基因表达量负相关机制,对miR-142-3p靶基因与脾脏中相对其他组织显著下调基因取交集,筛选潜在靶基因。结果表明：1）预测获得85个靶基因,GO富集分析显示,靶基因参与多种高分子化合物的合成与转运过程。2）KEGG结果显示富集到MAPK、Notch、Wnt等多条与抗肿瘤免疫相关的信号通路。3）PPI网络共筛选到4个Hub基因。4）miR-142-3p在脾脏中的表达量极显著高于肝脏、肺脏、胸肌、心脏和肾脏（P<0.01）。5）共筛选到TWF1、MYH10、NFIB、FNBP1L和FERMT2 5个靶基因。综上,鸡miR-142-3p在脾脏中很可能通过TWF1、MYH10、NFIB、FNBP1L和FERMT2 发挥生物学功能。本研究为解析鸡miR-142-3p的功能及其分子机制提供了参考和依据。     

西北肉用绵羊新品种群陶滩寒蒙组合生长发育性状的比较研究

以引进的无角陶赛特羊与滩羊、小尾寒羊和蒙古羊不同杂交组合的后代(F1、F2及F3)为研究对象,采用随机抽样的方法对已培育出的西北肉用绵羊新品种群部分杂交组合生长发育性状以及在不同月龄的体重、体高和体长等指标进行测定与分析,探讨培育新品种的最佳杂交组合模式.结果表明:杂种三代生长发育速度快于对应杂种二代,杂种二代生长发育速度快于对应杂种一代;3种杂交组合改良小尾寒羊和蒙古羊效果都好,尤其是高代或三元杂交经济效应更为显著.选择理想型的三代或二代杂种羊进行横交固定培育新品种的技术方案是可行的,培育的新品种群是国内肉用绵羊育种计划最具代表性和遗传性能表现最好的育种基础群和最宝贵的种质资源.     

Conversion of p,p' -DDT to p,p' -DDD by intestinal flora of the rat

p,p-DDD [1,1-dichloro- 2,2-bis(p-chlorophenyl)-ethane] occurs in the feces and livers of rats, that are given p, p-DDT [1,1,1-trichloro-2,2-bis-(p-chlorophenyl)-ethane] by stomach tube, but not of rats injected intraperitoneally with p,p-DDT. Coliform bacteria, isolated from feces of control animals, can effect reductive dechlorination of p,p-DDT to p,p-DDD. These findings indicate that the normal flora of the gastrointestinal tract, rather than the liver, as others have suggested, is the major source of the p,p-DDD that is found in animals fed p,p-DDT.     

Scoliosis in chickens: responsiveness of severity and incidence to dietary copper

The severity and incidence of spinal lesions were manipulated in a line of chickens susceptible to scoliosis by varying their dietary intake of copper. A decrease in expression of the lesion was related to increased intake of copper. The change in expression, however, appeared to be related only indirectly to the defects in collagen cross-linking, maturation, and deposition known to be associated with dietary copper deficiency. Thus, a dietary constituent in the range of normal intakes may act as an environmental factor in the expression of scoliosis.     

中草药及其制剂对猪、鸡、羊疾病的免疫调节作用

对临床上常见的猪无名高热,动物的垂脱症及鸡的法氏囊等病症,笔者采用西药疗法与中药补中益气、提升免疫力的疗法进行对比试验。治疗猪无名高热346例,西药治愈率为18%,用中草药治愈率为88%,治疗猪的直肠脱、阴道脱及山羊的阴道脱20例,西药治疗效果不好,全都是采用中药及手术疗法而治愈;治疗鸡法氏囊病采用了对比试验,中草药治愈率为80%,且中药治愈后复发比例生产、生长性能优越于西药疗法。大量研究表明,中草药多糖作为许多中药的主要免疫活动性物质,不仅促进机体的细胞和体液免疫,并能促进免疫器官的发育,增强免疫功能。     

鹌鹑性别鉴定的分子标记方法

采用PCR方法扩增北京白羽蛋用鹌鹑基因组中性别基因CHD相关片段,探讨鹌鹑性别的分子标记方法。通过特异引物2550F/2718R,对3对已知性别和14只未知性别鹌鹑性别基因片段进行特异性扩增。结果表明,这对引物从雄性鹌鹑中扩增出1条片段,从雌性鹌鹑中扩增出2条片段,可以对鹌鹑的性别作出准确鉴定。该方法可以应用于初生鹌鹑的性别筛选,降低饲养成本,提高经济效益。对2条片段进行克隆测序,片段长度分别为613和446bp。     

Susceptibility of mink to sheep scrapie

A progressive, fatal spongiform polioencephalopathy was induced in mink intracerebrally inoculated with a suspension of brain from a Suffolk sheep with naturally acquired scrapie. The clinical signs and pathological lesions of the experimental disease were indistinguishable from transmissible mink encephalopathy, a disease of undetermined origin that occurs in mink.     

鹌鹑脏器、肌肉蛋白质多型座位电泳技术

将应用于家畜血液蛋白质多型座位的电泳技术加以改进，成功地应用于鹌鹑脏器、肌肉蛋白质多型座位的检测，使可检测的鹌鹑蛋白质多型座位数从国内报道的３个增至３２个。详细介绍了检测３２个鹌鹑脏器、肌肉蛋白质多型座位的淀粉凝胶电泳技术，为客观评价鹌鹑遗传资源提供了科学的研究方法。