Arginine vasotocin: effects on development of reproductive organs

Immature 25-day-old mice were injected daily with 1 microgram of arginine vasotocin for 3 or 4 days and killed 24 hours after the last injection. The ovaries were 30 percent smaller in treated females than in controls. The ventral prostates and accessory organs (seminal vesicles and coagulating glands) were less than half the size of these structures in control males. Similar results were observed when 15-day-old mice were given similar injections and killed 2 weeks after the last injection; furthermore, testis weights were 28 percent smaller than those of controls. It is speculated that arginine vasotocin, which has been found in mammalian pineal glands, might mediate effects of the pineal gland on normal sexual development.     

Biosynthesis of a vasotocin-like peptide in cell cultures from pineal glands of human fetuses

Cultured cells from pineal glands of human fetuses release into their media a substance that has antidiuretic and hydroosmotic activities. The ratio of these activities as well as their susceptibility to tryptic digestion, specific oxidative inactivation by tyrosinase, and reductive inactivation by sodium thioglycollate, indicates the presence of a basic peptide, presumably identical with arginine vasotocin. The total amount of this peptide released into the culture media during 38 days of incubation is about ten times greater than the amount contained in nonincubated pineal glands from fetuses of the same age, strongly suggesting that fetal ependymal cells from the pineal gland can synthesize in vitro a peptide similar to arginine vasotocin.     

Abnormal water balance in a mutant strain of chickens

Polydipsia and polyuria are pronounced in chickens of a selected strain and this diabetes insipidus is inherited. The kidneys of such birds are capable of an antidiuretic response when lysine vasopressin or arginine vasotocin is injected. Osmotic pressure and sodium concentration of the plasmas of normal and mutant chickens are identical. Chicks predicted to have diabetes insipidus on the basis of parental pedigree are polydipsic.     

生殖激素对龟类生殖调控的研究进展

迄今为止,已发现有11种生殖激素参与龟类生殖调控。雌二醇和睾酮在促性腺激素释放激素、卵泡刺激素和黄体生成素的调控下主导调控龟类性腺发育、配子生成、交配、产卵及子代性别决定等重要生殖环节。孕酮、前列腺素、精氨酸催产素、皮质酮、甲状腺素和褪黑激素协同调节龟类生殖活动。在人工繁殖方面,使用GnRH等有助于克服龟类繁殖障碍,提高繁殖效率。对生殖激素对龟类生殖活动的调控作用与机理及其应用的研究进展进行了综述。     

Antithrombin 3. Protection against death after injection of thromboplastin

Intravenous injection of autologous lipoprotein (thromboplastin) or thrombin produced a lethal, hemorrhagic syndrome in chicken embryos. The embryos could be protected from this fatal result by injection of antithrombin III, an alpha(2)-globulin (molecular weight 60,000 to 80,000) purified from human, bovine, and guinea pig blood. Heparin also protected the embryos, but other inhibitors were less protective.     

NF-κB、MIF在子宫内膜异位症的表达及其相关性研究

采用免疫组织化学SABC法检测30例对照组子宫内膜、35例子宫内膜异位症患者的在位内膜及60例子宫内膜异位症患者的异位内膜中核转录因子-κB(NF-κB)、巨噬细胞迁移抑制因子(MIF)的表达。结果表明:NF-κB、MIF主要表达于3组内膜的腺上皮细胞,在异位内膜的间质及血管内皮细胞中亦有表达。对照组子宫内膜低表达,而在患者异位内膜的表达最强(P<0.01);NF-κB与MIF在3组内膜中的表达具有较强的相关性,相关系数分别是0.875、0.882、0.927。NF-κB、MIF在子宫内膜异位症患者的在位及异位的内膜中有异常高表达,而在正常子宫内膜组织中低表达;NF-κB与MIF的表达呈正相关。NF-κB可能通过上调MIF的表达在子宫内膜异位症发病机制中起重要作用。     

牦牛乳酸脱氢酶A的分离纯化、酶学性质及其基因的克隆

 【目的】分离纯化牦牛骨骼肌中的乳酸脱氢酶-A（LDH-A）,并克隆其cDNA。通过比较牦牛与普通牛的LDH-A的酶学性质和cDNA序列,为研究牦牛适应高海拔、低氧环境,在分子水平上找到一些线索。【方法】采用染料亲和层析和DEAE-Sephadex离子交换层析等方法,分别从牦牛和普通牛骨骼肌中纯化LDH-A,并对其酶学性质进行比较;通过RT-PCR方法克隆牦牛LDH-A的cDNA序列,并与GenBank登录的普通牛LDH-A的cDNA序列进行比对。【结果】纯化的牦牛LDH-A比活力为103.9 U•mg-1蛋白,纯化倍数为18.2。SDS-PAGE和PAGE分析均显示一条带。酶动力学参数测定显示,牦牛LDH-A的Km NADH为0.097,Km 丙酮酸钠为1.897,均不同程度高于普通牛,其中对丙酮酸钠的Km大约是普通牛的2倍。根据牦牛LDH-A的cDNA序列预测的氨基酸序列与普通牛LDH-A的氨基酸序列比较,只有2个氨基酸残基的改变（257Val-Ala和315Tyr-Cys）。【结论】牦牛LDH-A对丙酮酸的高Km可避免骨骼肌中产生过多的乳酸,是适应进化的结果;这种升高可能与其氨基酸序列变化导致的空间结构微小改变有关。     

Inhibition of serum- and ras-stimulated DNA synthesis by antibodies to phospholipase C

Several immunologically distinct isozymes of inositol phospholipid-specific phospholipase C (PLC) have been purified from bovine brain. Murine NIH 3T3 fibroblasts were found to express PLC-gamma, but the expression of PLC-beta was barely detectable by radioimmunoassay or protein immunoblot. A mixture of monoclonal antibodies was identified that neutralizes the biological activity of both endogenous and injected purified PLC-gamma. When co-injected with oncogenic Ras protein or PLC-gamma, this mixture of antibodies inhibited the induction of DNA synthesis that characteristically results from the injection of these proteins into quiescent 3T3 cells. However, when oncogenic Ras protein or PLC-gamma was co-injected with a neutralizing monoclonal antibody to Ras, only the DNA synthesis induced by the Ras protein was inhibited--that induced by PLC was unaffected. These results suggest that the Ras protein is an upstream effector of PLC activity in phosphoinositide-specific signal transduction and that PLC-gamma activity is necessary for Ras-mediated induction of DNA synthesis.     

常乳中牛乳铁蛋白的纯化及抗菌活性研究

[目的]研究从常乳中纯化牛乳铁蛋白的工艺条件,探讨牛乳铁蛋白的抗菌活性。[方法]选用SP sepharose HP作为强阳离子交换介质,利用AKTApurifier10高效液相色谱仪纯化牛乳铁蛋白。[结果]结果表明,牛乳铁蛋白在pH值7.5、浓度0.85 mol/L的NaCl洗脱液中可以被洗脱下来,且产品纯度为90%以上。牛乳铁蛋白浓度为5 mg/ml时对大肠杆菌的生长具有显著的抑制作用。[结论]该研究建立了从常乳中纯化牛乳铁蛋白的方法,为大规模生产具有活性的牛乳铁蛋白奠定了基础。     

Repression of ornithine transcarbamylase protein formation by arginine

Arginine-repressed cells of Escherichia coli W do not form a protein immunologically related to ornithine transcarbamylase. This was determined by lack of cross-reactivity of repressed cell extracts with rabbit antisera prepared against purified ornithine transcarbamylase. The results indicate that arginine acts by blocking the synthesis of the entire enzyme-protein.     

A Method of Purification of Bovine Colostrum sIgA

sIgA in bovine colostrum was purified by ultrafiltration and enzymolysis methods in this experiment, and the prepared substance was detected by Western Blot. The purity and yield were up to 73.6% and 65.2%, respectively. This convenient technique offers helpful exploration for production of bovine colostrum sIgA.     

Mass-dependent and -independent fractionation of hg isotopes by photoreduction in aquatic systems

Mercury (Hg) isotopes can be used as tracers of Hg biogeochemical pathways in the environment. The photochemical reduction of aqueous Hg species by natural sunlight leads to both mass-dependent fractionation (MDF) of Hg isotopes and mass-independent fractionation (MIF) of the odd-mass isotopes, with the relation between the MIF for the two odd isotopes being distinct for different photoreduction pathways. Large variations in MDF and MIF are observed in fish and provide new insights into the sources and bioaccumulation of Hg in food webs. MIF in fish can also be used to estimate the loss of methylmercury via photoreduction in aquatic ecosystems.     

牛胎肺间充质干细胞体外培养及生物学特性研究

[目的]建立牛胎肺间充质干细胞（Mesenchymal stem cells,MSCs）体外培养体系并对其进行生物学特性研究。[方法]取3～5月龄牛胎儿肺脏,得到MSCs。通过控制胰酶消化时间,去除难消化的上皮样贴壁细胞,获得纯化的牛肺MSCs,研究其形态、增殖情况及体外诱导分化潜能。[结果]牛胎肺MSCs可在体外扩增培养,传至24代以上,表达CD29、CIM4和CDl66,不表达CDM、CIM5和BOL-DR,并具有向成骨细胞诱导分化的潜能。[结论]从牛胎肺中可以分离出MSCs,可以在体外培养,并可诱导分化为成骨细胞。     

Cysteine stimulation of glucose oxidation in thyroid tissue

Oxidation of D-glucose-C(14) by bovine thyroid slices was stimulated by cysteine, 2-aminoethanethiol, and cystamine. Amino acids tested, other than cysteine, were not stimulatory, except tyrosine and arginine to a slight degree. The pattern of stimulation resembled that brought about by thyroid-stimulating hormone. Stimulation of labeled CO(2) production was greater when glucose-1-C(14) rather than glucose-6-C(14) was the substrate.     

Nonidentity of fetuin and protein growth (flattening) factor

Fetuin, a fetal calf serum glycoprotein, appeared to possess activity with cultured mammalian cells similar to that of a protein growth factor partially purified from adult bovine and human sera. Column chromatography, however, yielded highly purified but inactive fetuin. These results leave open questions regarding the role of this interesting and readily purified protein.     

牛eIF5基因原核表达与蛋白纯化

研究应用PCR方法扩增牛e IF5基因编码序列,通过Eco RⅠ和SalⅠ酶切位点将其定向插入p GEX-4T-1载体,构建原核表达重组质粒p GEX-4T-1-e IF5,并转化大肠埃希菌BL21。酶切和测序鉴定正确后,用异丙基硫代-β-D-半乳糖苷(IPTG)大量诱导表达,利用GST-Sepharose 4B亲和珠纯化,SDS-PAGE和Western Blot鉴定。结果表明,原核表达载体p GEX-4T-1-e IF5构建成功,Western Blot证实融合蛋白大量表达,纯化后获得GSTe IF5融合蛋白,为深入研究牛e IF5蛋白功能奠定基础。     

Isolation and Purification of Bovine Colostrum sIgA and IgG

To further utilize bioactive substance such as bovine colostrum sIgA and IgG,sIgA and IgG were isolated and purified simultaneously by salting out,ultrafiltration and gel chromatography,etc.The analysis of results were showed quantitatively by non-hydrogenized SDS-PAGE,and quanlities of sIgA and IgG were respectively detected by Western Blot.The results showed that the purity and yield of bovine colostrum sIgA were 85.3%and 42.8%,respectively,while the purity and yield of bovine colostrum IgG were respectively 97.2%and 64.4%.This preparative method provides theoretical and experimental foundation for sIgA industrial production.     

牛病毒性腹泻病毒夹心ELISA快速检测方法的建立与初步应用

用增殖与浓缩后的牛病毒性腹泻病毒(BVDV)分别免疫健康牛犊和家兔,制备牛抗BVDV和兔抗BVDV超免疫血清,并用层析法纯化牛抗BVDV IgG和兔抗BVDV IgG,建立了检测BVDV的双抗体夹心ELISA快速检测方法.结果表明:该检测方法的最佳反应条件为:牛抗BVDV IgG包被浓度为100μg/mL,兔抗BVDV IgG最佳工作浓度为50μg/mL,样品反应时间为90min,酶标抗体工作浓度为1∶8 000,以D490nm≥0.177作为阳性判定标准.该ELISA检测方法的重复性CV小于10%,最低检测限为1.87μg/mL,与牛轮状病毒、牛冠状病毒、猪瘟病毒、犊牛大肠杆菌和沙门菌等病原无交叉反应,该ELISA试剂在室温下至少可保存6个月.用该ELISA方法和IDEXX公司抗原检测试剂盒对甘肃省不同地区牛场156份临床粪便样品进行了检测,阳性检出率分别为17.3%和16.7%.表明本试验建立的ELISA方法特异性强、敏感性高且重复性好,可用于BVDV的快速检测.     

THYMECTOMY: PROLONGATION OF IMMUNOLOGICAL TOLERANCE IN THE ADULT MOUSE

The loss of acquired immunological tolerance of mice to bovine gamma globulin depended on the presence of the thymus. Mice were repeatedly injected with bovine gamma-globulin from birth until the age of 5 to 10 weeks and then thymectomized or sham operated. After 130 to 160 days without antigen, an accelerated (immune) disappearance of I(125) bovine gamma-globulin could be uniformly induced in controls while thymectomized mice remained tolerant. Adult thymectomized mice made tolerant by a single injection of bovine gamma-globulin lost tolerance more slowly than sham-operated controls.     

Isolation of infectious bovine rhinotracheitis virus from the soft-shelled tick, Ornithodoros coriaceus

Infectious bovine rhinotracheitis virus was isolated from the soft-shelled tick (Ornithodoros coriaceus). Serological identification of the isolated viruses was confirmed by restriction endonuclease digestion of purified virus DNA. These isolations indicate that the soft-shelled tick may be a vector for infectious bovine rhinotracheitis virus. This may be the first reported isolation of mammalian herpesvirus from an arthropod vector.