胎牛成纤维细胞的分离培养

应用组织块培养法从胎牛耳部分离培养了胎牛成纤维细胞。应用PCR方法鉴别了细胞的性别。选择雌性成纤维细胞,进行了形态观察、生长曲线测定、染色体分析。结果表明,分离培养的细胞具有正常的大小、形态、分裂增殖特性和染色体数目。胎牛成纤维细胞的培养方法的建立以及其相关的生物学特性的分析,有利于给同种和异种体细胞克隆牛研究提供形态良好、染色体数目正常的供体细胞,同时也为体细胞转基因等其他领域的研究提供了基础条件。     

新疆牛源豕链球菌的部分生物学特性

为查明发生于新疆塔城地区某农场成年牛所发生的一种以流涎,狂躁或低头呆立,视力障碍,咽喉水肿,脑膜出血为特征的传染性疾病的病原,采集该农场濒死期病牛的脑、心血、肝、脾和淋巴结,分离其病原,研究病原的形态学特性、培养特性、API STREP 20生化特性、链球菌乳胶凝集诊断试剂的血清学特性;采用平板法观察细菌对绵羊血和兔血的溶血情况;根据NCSL标准采用纸片法检测对临床常用抗生素的耐药谱;选用清洁级小白鼠和家兔作为实验动物,观察分离株的毒力和致病性.结果表明:引起该此发病的病原为豕链球菌,血清学类型为兰氏B型,分离株有较强的毒力和致病性且对青霉素和四环素有耐药性.     

牛传染性鼻气管炎的诊断和预防研究进展

牛传染性鼻气管炎是一种由牛传染性鼻气管炎病毒感染引起的牛呼吸道接触性传染病,临床多表现为呼吸道症状,同时伴有多器官的炎症,还会引起妊娠母牛流产.该病毒可以感染任何年龄、品种的牛,对犊牛的危害最大.随着现代化牧场的规模不断扩大、集约化程度日益增高,该病的发病率也在逐年上升,阻滞了奶牛业以及肉牛养殖业的健康发展.从牛传染性鼻气管炎的诊断方法和预防措施方面阐述近年来该病的研究进度,以期为牛传染性鼻气管炎疾病的诊断和预防提供参考.     

Morphological and electrophysiological evidence for regeneration of transected spinal cord fibers and restoration of motor functions in adult rats

The evoked potentials are regarded as an efficientindex to evaluate the functional status of a nervoussystem[1]. When stimulating the motor area of cerebralcortex with transcranial magnetic stimulation, elec-tronic signals can be obtained at the spinal co…     

高效液相色谱—电喷雾—质谱法测定蛋白质混合物

介绍高效液相谱－电喷雾－质谱（HPLC－ESI－MS）联用技术在生物大分子（蛋白）的分离和检测上所表现出来的优越性能,并利用LC－ESI－MS技术成功地分离、检测溶菌酶和牛血清蛋白混合物。     

壳聚糖微珠作为亲和层析载体的制备及其用于分离牛凝血酶的研究

在壳聚糖微珠的制备过程中壳聚糖的浓度，交联剂等因素直接影响壳聚糖微珠的质量和性能。用于牛凝血酶亲和层析载体的壳聚糖微珠制备，以壳聚糖浓度为1．5％，交联剂浓度较大时比较适宜，壳聚糖微珠经过环氧氯丙烷活化并与肝素耦联制成亲和层析剂分离和纯化牛凝血酶，每克干物质可吸附5800IU凝血酶，进一步纯化回收率可达到84％。未经活化与肝素耦联的壳聚糖微珠对牛凝血酶则无特异吸附作用。     

成年神经干细胞研究及应用展望

成年神经干细胞(adult neural stem cells ANSCs)起源于人脑室管膜下层、海马的齿状回和嗅回。它具有增殖、多向分化的潜能，能分化成神经元和神经胶质细胞，并迁移到相应的脑区整合在神经网络中。这为利用神经干细胞治疗脑的损伤、退行性病变、帕金森氏综合症(Parkinson’s)、老年性痴呆、多发性硬化症等带来了十分诱人的前景。     

导数紫外光谱法研究牛血清白蛋白与十二烷基硫酸钠的相互作用

利用导数紫外光谱法研究了在pH=7.40,离子强度I=0.013 1 mo.lL-1的磷酸盐缓冲溶液中,浓度为1.5×10-5mo.lL-1的牛血清白蛋白(BSA)与十二烷基硫酸钠(SDS)相互作用的过程中,芳香族氨基酸残基微环境极性的变化.通过研究发现,当SDS浓度小于5×10-4mol.L-1时,三种芳香族氨基酸残基微环境的极性几乎没有发生变化.当SDS浓度大于5×10-4mol.L-1时,苯丙氨酸(Phe)残基所处微环境的极性稍有增强,而酪氨酸(Tyr)残基所处微环境的极性在增强后稍有减弱,色氨酸(Trp)残基所处微环境的极性在减弱后保持基本不变.根据这些氨基酸残基所处微环境的极性的变化,可以判断BSA构象的变化.     

Clone of Chinese Jinan red-cross yellow cattle and evaluation of reproductive characteristics of cloned calf

Somatic cell clone technology is a viable approach to preserving endangered livestock and wildlife genetic resources. In the present research, somatic cell nuclear transfer （SCNT） was performed using granulose cells from the critical endangered Chinese red-cross yellow cattle as donor cells. A total of 211 oocytes were manipulated and 166 （79%） of them were successfully enucleated. 112 （67.4%） SCNT embryos were reconstructed, 94 （83%） of them cleaved, and 48 （43 %） of them developed to blastocyst stage. SCNT blastocysts were transferred to 6 Holstein recipients, and 2 （33%） of them were found to be pregnant. One of them maintained to term and delivered a calf, whereas another aborted. Effect of different fusion buffer （mannitol vs. Zimmerman fusion buffer） and different activation methods （calcium ionophore＋6-DMAP vs. cycloheximide＋CB） on fusion rate and development of SCNT embryos were investigated. The results indicated that： （i） on condition of two DC pulses of 2.5 kV/cm for 10 μs each, fusion rates were higher in mannitol solution than in Zimmerman fusion buffer （71% vs. 61%, respectively, p 〈 0.05）, but the blastocysts rates did not differ between two treatments （36 % vs. 39 %, p〉0.05 ）; （ii） There was no significant difference in development rates to the blastocyst stage for SCNT embryos activated by calcium ionophore＋6-DMAP or by cycloheximide＋CB （42% vs. 46%, respectively, p〉0.05）. Microsatellite DNA analysis examining 28 loci confirmed that the cloned calf was genetically identical to the donor Jinan red-cross yellow cattle and different from the recipient females. Growth and reproductive performance of cloned cow were evaluated, and there were no difference i cross-red n it between cloned and normal control Jinan yellow cattle. Furthermore, the cloned yellow cow has delivered a healthy yellow calf.