鸡精原干细胞定向诱导分化特性的研究

取孵化18～20d的鸡胚睾丸，分离精原干细胞（SSCs），培养传代3次后，用特异性化学物质定向诱导分化，以研究鸡培养传代后SSCs保持多向分化的潜能。①用特异的化学物质地塞米松、β-磷酸甘油钠、维生素C诱导鸡SSCs向成骨细胞分化，用Von Kossa＇s法、改良的钙钴法及免疫组化法进行成骨细胞鉴定；②用维甲酸（RA）、3-异丁基-1-甲基黄嘌呤（IBMX）诱导SSCs向神经元样细胞分化，甲苯胺蓝特异染色和组织化学鉴定。③用地塞米松、胰岛素、3-异丁基-1-甲基黄嘌呤（IBMX）诱导SSCs向脂肪细胞分化，特异性的油红O染色和脂肪细胞标志基因PPAR7检测。结果显示，SSCs被诱导15～21d后分化为成骨细胞，诱导形成率为80％；Von Kossa＇s染色细胞间布满黑色颗粒，具有矿化基质沉积；改良钙钴法碱性磷酸酶染色胞浆呈深棕色或深黑色，免疫组化染色细胞呈阳性。SSCs被诱导3～7d后分化为神经元样细胞，甲苯胺蓝染色阳性率为85％。SSCs被诱导7～21d后，分化成脂肪细胞，分化率为85％。诱导的脂肪细胞经特异性的油红O染色为阳性，并高表达脂肪细胞标志基因PPARγ。结论：在不同的诱导条件下，SSCs可被定向诱导分化为3种成体细胞，证明其培养传代后仍具有多向分化能力。     

诱导鸡胚精原干细胞向成骨细胞分化的研究

为了探讨体外培养的鸡胚精原干细胞(SSCs)的多向分化潜能,取孵化18~20 d的鸡胚睾丸,无菌获取SSCs,体外培养传代,通过地塞米松、β-甘油磷酸钠、维生素C诱导鸡胚SSCs向成骨细胞分化,钙结节Von Kossa s法、改良的钙钴法及免疫组化法进行成骨细胞鉴定。结果显示SSCs被诱导15~21 d后分化为成骨细胞,诱导形成率为75%~80%;诱导后的细胞Von Kossa s染色可见细胞间布满黑色颗粒,提示有矿化基质沉积;改良钙钴法碱性磷酸酶染色胞浆呈深棕色或深黑色,免疫组化法染色细胞呈阳性。因此可以得出在不同的诱导条件下,SSCs体外可被定向诱导分化为成骨细胞,证明其具有多向分化潜能。     

蒙古马骨髓间充质干细胞的分离培养及多向分化潜能的研究

旨在探索一个高效分离和扩增蒙古马骨髓间充质干细胞的方法,并通过形态学和多向分化能力进行鉴定.抽取蒙古马骨髓标本,利用密度梯度离心和差异贴壁法分离MSCs,体外扩增后传代,进行相差显微镜形态学观察.在地塞米松、IBMX、胰岛素及罗格列酮的作用下向脂肪细胞诱导分化,以及在地塞米松、VitC、β-磷酸甘油等作用下向成骨细胞诱导分化.结果显示原代和传代细胞呈梭形成纤维细胞样外观,生长增殖能力良好.经定向诱导分化后,细胞分别呈现脂肪细胞、成骨细胞的表型特征.证明所纯化的细胞为尚未分化的基质细胞,而不是组织的成体细胞,它具有多向分化潜能.     

鸡胚原始生殖细胞定向诱导分化成骨细胞的研究

探讨体外培养的鸡胚胎原始生殖细胞(EPGCs)的多向分化潜能。分别从发育至19期和28期的鸡胚胎性腺中获取EPGCs,体外培养传代。通过地塞米松、β-甘油磷酸钠和维生素C诱导EPGCs向成骨细胞分化,分别进行碱性磷酸酶改良钙钴法染色鉴定、钙结节Von Kossa's染色鉴定和免疫组化鉴定。结果表明:EPGCs被诱导21 d后,定向分化成成骨细胞,诱导率达到80%,碱性磷酸酶改良钙钴法染色、钙结节Von Kossa's染色和免疫组化鉴定均呈阳性,阳性率为75%-85%。由此可得出在诱导条件下,EPGCs体外可定向诱导分化为成骨细胞。     

鸡脑神经干细胞体外诱导分化研究

为了研究鸡脑神经干细胞(neural stem cells,NSCs)体外的分离、培养及诱导分化等生物学特性,试验采用机械吹打法分离鸡脑神经干细胞,通过免疫荧光对体外培养鸡脑神经干细胞进行表面标记检测,并在适宜的诱导条件下向神经元细胞、星形胶质细胞和少突胶质细胞三个方向进行诱导,检测其多向分化潜能。结果表明:体外分离培养的鸡NSCs为目的细胞,并可向神经元细胞、星形胶质细胞和少突胶质细胞诱导分化。说明鸡脑NSCs具有良好的体外增殖能力和多向分化潜能。     

北京油鸡羊膜上皮细胞的分离、培养及分化潜能的研究

旨在研究禽类胚胎羊膜上皮细胞的分离、培养、鉴定及向不同胚层细胞诱导分化等的生物学特性.本研究使用酶消化法从北京油鸡胎膜中分离羊膜上皮细胞,通过免疫荧光和RT-PCR方法鉴定羊膜上皮细胞标志物(Nanog、Oct-4、Sox-2、CK19和Vimentin),并诱导其向成骨细胞、脂肪细胞和胰岛样细胞诱导分化,检测其多向分化潜能.结果表明,酶消化法获得的鸡羊膜上皮细胞不仅表达干细胞特有的标志,而且成功诱导分化为成骨细胞、脂肪细胞和胰岛样细胞.综上所述,北京油鸡羊膜上皮细胞在体外具有较强的自我更新能力及可塑性,可作为种子细胞进行濒危物种的保存,并为日后利用羊膜上皮细胞进行临床治疗提供一定的理论依据,同时也可为油鸡基因的改良提供模型.     

蒙古羊骨髓间充质干细胞的分离培养及多向诱导分化

本研究旨在建立蒙古羊骨髓间充质干细胞(bone marrow mesenchymal stem cell,BMSC)体外分离、纯化、增殖方法,诱导其向脂肪细胞、成骨细胞及软骨细胞分化。穿刺法抽取蒙古羊骨髓组织,采用密度梯度离心法结合贴壁培养法分离纯化BMSC,增殖,并测定其生长曲线及细胞倍增时间。对第3代蒙古羊BMSC进行成脂、成骨及成软骨诱导,观察诱导后的细胞形态。采用油红O、茜素红、HE等染色法在组织学水平对BMSC进行成脂、成骨和成软骨分化鉴定。结果显示,蒙古羊BMSC呈现均一梭形成纤维细胞样生长,生长曲线呈S型,生长增殖能力良好。在不同分化诱导之后,细胞呈现脂肪细胞、成骨细胞及软骨细胞的表型特征。表明获得的蒙古羊BMSC具有多向分化潜能,所分离细胞确为骨髓间充质干细胞。     

脂肪细胞去分化及其调控机制研究进展

脂肪发育、沉积及代谢直接影响动物的生产及肉类产品品质,也与人类的健康息息相关。成熟的脂肪细胞在体内和体外均具有去分化生成可增殖细胞的能力,这种可增殖细胞被称为去分化脂肪(DFAT)细胞。DFAT细胞具有多能干细胞的特性和多向分化潜能,可以分化为脂肪细胞、平滑肌细胞、心肌细胞、成骨细胞和神经细胞等。本文在阐述体内外成熟脂肪细胞去分化的基础上,重点综述了DFAT细胞的多向分化潜能、去分化调控机制及其在猪上的相关研究进展,为通过调控脂肪细胞的去分化,进而改善肉品质、提高人类健康水平提供一定理论依据。     

胚胎干细胞定向分化研究进展(下)

(续上期 )尽管在造血生长因子的刺激及基质细胞存在的情况下 ,ES细胞可以向造血细胞分化 ,但是离临床应用还有相当长的距离。如何诱导ES细胞高效地向某一系造血细胞或血液细胞分化的方法还不成熟。比如ES细胞在体外能分化形成淋巴细胞 ,但效率很低 ,只有少数拟胚体 (EB)中含有淋巴细胞 ,表明诱导ES细胞分化为淋巴细胞尚需补充一些其他的未知因子。而且要尽可能模拟体内造血生成的环境。2 2　向神经细胞的定向分化　在体外培养中 ,用全反式维甲酸 (RA)能诱导ES细胞向神经细胞分化 ,可形成有典型神经冲动等电生理反应的神经细胞 ,神经…     

胚胎干细胞体外诱导分化的研究进展

胚胎干细胞(embryonic stem cell，ES细胞)是由早期胚胎内细胞团(ICM)或原始生殖(PGC)细胞经体外分离、抑制分化培养获得的多潜能细胞。ES细胞具有发育分化的多潜能性和无限的自我更新能力，能在体外长期培养并具有向机体各种组织细胞分化的潜能。由于ES细胞的全能性，在体外可以分化出包括3个胚层在内的所有细胞，     

白术、微米白术和白术多糖对断奶仔猪生长性能和肠道形态及微生态区系的影响

试验选用96头平均体重14.82 kg左右的杜×长×大断奶仔猪,随机分成4组,每组3栏,每栏8头(公母各半)。对照组饲喂基础日粮,试验1、2、3组分别添加1%80目白术、0.2%白术多糖和1%微米白术。试验期30 d。结果表明:在生长性能方面,与对照组相比,1%微米白术添加组可显著提高日增重(P0.05)、降低饲料增重比和腹泻率,而且效果优于1%80目白术组和0.2%白术多糖组,在肠道形态和肠道微生态区系方面,与对照组相比,日粮添加1%80目白术、0.2%白术多糖、1%微米白术均可不同程度的提高十二指肠和空肠的绒毛高度,加深十二指肠和空肠的隐窝深度,并且增加肠道微生态区系的多样性,其中以1%微米白术添加组的效果最佳。     

Feline intracranial neoplasia: retrospective review of 160 cases (1985-2001)

The purpose of this study was to determine the frequency of different tumor types within a large cohort of cats with intracranial neoplasia and to attempt to correlate signalment, tumor size and location, and survival time for each tumor. Medical records of 160 cats with confirmed intracranial neoplasia evaluated between 1985 and 2001 were reviewed. Parameters evaluated included age, sex, breed, FeLV/FIV status, clinical signs, duration of signs, number of tumors, tumor location(s), imaging results, treatment, survival times, and histopathologic diagnosis. Most of the cats were older (11.3 +/- 3.8 years). Primary tumors accounted for 70.6% of cases. Metastasis and direct extension of secondary tumors accounted for only 5.6 and 3.8% of cases, respectively. Twelve cats (7.5%) had 2 or more discrete tumors of the same type, whereas 16 cats (10.0%) had 2 different types of intracranial tumors. The most common tumor types were meningioma (n = 93, 58.1%), lymphoma (n = 23, 14.4%), pituitary tumors (n = 14, 8.8%), and gliomas (n = 12, 7.5%). The most common neurological signs were altered consciousness (n = 42, 26.2%), circling (n = 36, 22.5%), and seizures (n = 36, 22.5%). Cats without specific neurological signs were common (n = 34, 21.2%). The tumor was considered an incidental finding in 30 (18.8%) cats. In addition to expected relationships (eg, meninges and meningioma, pituitary and pituitary tumors), we found that lesion location was predictive of tumor type with diffuse cerebral or brainstem involvement predictive of lymphoma and third ventricle involvement predictive of meningioma.     

Prevalence and seasonal incidence of nematode parasites and fluke infections of sheep and goats in eastern Ethiopia

Sissay, M.M., Uggla, A. and Waller, P.J., XXXX. Prevalence and seasonal incidence of nematode parasites and fluke infections of sheep and goats in eastern Ethiopia. Tropical Animal Health and Production, XXXX. A 2-year abattoir survey was carried out to determine the prevalence, abundance and seasonal incidence of gastro-intestinal (GI) nematodes and trematodes (flukes) of sheep and goats in the semi-arid zone of eastern Ethiopia. During May 2003 to April 2005, viscera including liver, lungs and GI tracts were collected from 655 sheep and 632 goats slaughtered at 4 abattoirs located in the towns of Haramaya, Harar, Dire Dawa and Jijiga in eastern Ethiopia. All animals were raised in the farming areas located within the community boundaries for each town. Collected materials were transported within 24 h to the parasitology laboratory of Haramaya University for immediate processing. Thirteen species belonging to 9 genera of GI nematodes (Haemonchus contortus, Trichostrongylus axei, T. colubriformis, T. vitrinus, Nematodirus filicollis, N. spathiger, Oesophagostomum columbianum, O. venulosum, Strongyloides papillosus, Bunostomum trigonocephalum, Trichuris ovis, Cooperia curticei and Chabertia ovina), and 4 species belonging to 3 genera of trematodes (Fasciola hepatica, F. gigantica, Paramphistomum {Calicohoron} microbothrium and Dicrocoelium dendriticum) were recorded in both sheep and goats. All animals in this investigation were infected with multiple species to varying degrees. The mean burdens of adult nematodes were generally moderate in both sheep and goats and showed patterns of seasonal abundance that corresponded with the bi-modal annual rainfall pattern, with highest burdens around the middle of the rainy season. In both sheep and goats there were significant differences in the mean worm burdens and abundance of the different nematode species between the four geographic locations, with worm burdens in the Haramaya and Harar areas greater than those observed in the Dire Dawa and Jijiga locations. Similar seasonal variations were also observed in the prevalence of flukes. But there were no significant differences in the prevalence of each fluke species between the four locations. Overall, the results showed that Haemonchus, Trichostrongylus, Nematodirus, Oesophagostomum, Fasciola and Paramphistomum species were the most abundant helminth parasites of sheep and goats in eastern Ethiopia.     

Y‐chromosomal variation of local goat breeds of Turkey close to the domestication centre

Genetic variations in chromosome Y are enabling researchers to identify paternal lineages, which are informative for introgressions and migrations. In this study, the male‐specific region markers, sex‐determining region‐Y (SRY), amelogenin (AMELY) and zinc finger (ZFY) were analysed in seven Turkish native goat breeds, Angora, Kilis, Hair, Honaml?, Norduz, Gürcü and Abaza. A SNP in the ZFY gene defined a new haplotype Y2C. All domestic haplogroups originate from Capra aegagrus, while the finding of Y1A, Y1B, Y2A and Y2C in 32, 4, 126 and 2 Turkish domestic goats, respectively, appears to indicate a predomestic origin of the major haplotypes. The occurrence of four haplotypes in the Hair goat and, in contrast, a frequency of 96% of Y1A in the Kilis breed illustrate that Y‐chromosomal variants have a more breed‐dependent distribution than mitochondrial or autosomal DNA. This probably reflects male founder effects, but a role in adaptation cannot be excluded.     

The Prevalence and Intensity of Helminth and Coccidial Infections in Dairy Cattle in Central Kenya

A survey of gastrointestinal parasite infections of young (<6 months old), immature (6–12 months old) and adult (>12 months old) dairy cattle on 16 farms in Kiambu District, Kenya was conducted during a dry season (September 1991 to January 1992) and during a wet season (March to July 1992). The survey was based on monthly coproparasitological examination of cohorts and worm counts in tracer calves. The effects of age, sex, farm and season on the prevalence and intensity of helminth and coccidial infections were determined. Faecal egg and oocyst counts revealed that the overall prevalences were: strongyles (including trichostrongyles) (85.5%), liver flukes (Fasciola gigantica) (34.0%), coccidia (30.9%) and tapeworms (9.6%). Eight species of the protozoan Eimeria were identified, the most prevalent species being E. bovis and E. zuernii. The most prevalent nematode genera were Haemonchus, Cooperia, Oesophagostomum and Trichostrongylus. Season, farm and age of the animals had a significant (p<0.05) influence on the intensity of infection with strongyles, liver flukes and coccidia, whereas the sex of the animals had no significant (p>0.05) effect on the prevalence or intensity of infections. A higher intensity of infection with strongyles and coccidia was found in the wet season than in the dry season (p<0.05). The age-specific intensity was in the following order: for strongyles, immature animals of 6–12 months of age had the highest egg counts, followed by young calves and adults. Calves had significantly (p<0.05) higher oocyst counts than immatures or adults. Liver fluke egg counts did not differ significant (p>0.05) between immatures and adult cattle.     

A brief history of the prevention of infectious diseases by immunisations

Infectious diseases have always been a terrible scourge for humans. The appearance of these plagues, as they were called without distinction, was generally connected to various conditions: asters, climatic changes or religious reasons. The concept of contagious, and then infectious, diseases came slowly. Variolation, i.e. transmission of ‘virulent’ matter to induce a natural disease and the immunity against it, was brought from Constantinople to England by Lady Montague, in 1721. This ‘variolation’ technique was also often performed in veterinary medicine against diseases like sheep-pox or pleuropneumonia. As ‘vaccination’ is the term generally accepted for ‘immunisation’, variolation can be the word designating such a technique. The second period of the history of immunisation began, in 1880, with the studies of Pasteur and his collaborators. A great number of bacterial vaccines were developed: dead, live but attenuated or only parts of pathogens. The viruses were produced in animals, then in eggs and at last, in tissue cultures. Second generation vaccines appeared with genetic engineering: recombinant vaccines, vector vaccines, nucleic acids vaccines, and markers vaccines, among others. These novel technologies can permit the development of new ones and improve the quality of the vaccines already existing.     

Micronutrient Content of Certain Tropical Conventional and Unconventional Feed Resources of Southern India

The ash, silica and certain important micronutrients were estimated in conventional and unconventional feed and fodder resources available in Southern India. Commonly used dry roughages, such as paddy straw, ragi straw, maize kadbi/stalk, jowar kadbi/stalk, bajra stalk and wheat straw, were high in ash (9.9% +/- 0.77%) and silica (6.4% +/- 0.65%) and low in most of the other micronutrients, except iron, with paddy straw containing most silica (>9%). Cultivated non-leguminous (maize, jowar) and improved green crops (hybrid napier, guinea, green panic, NB-21, CO-1) were also high in ash (10.5% +/- 0.60% and 12.5% +/- 0.51%) but were moderate sources of P, Mg and Cu and good sources of Zn (98 +/- 13.8 ppm and 55 +/- 6.7 ppm). Leguminous green fodders (stylosanthus, lucerne, cow pea, soyabean) were excellent sources of Ca (1.9% +/- 0.16%), Mg (0.40% +/- 0.05%), Cu (30 +/- 5.2 ppm), Zn (121 +/- 14.7 ppm) and Fe (1234 +/- 166 ppm) and moderate sources of P. Mixed local grasses and weeds were high in silica (6.9% +/- 1.00%) but were good sources of Cu, Zn and Fe. Cereal grains (maize, wheat, rice, ragi) were low in ash (2.9% +/- 0.33%) and were relatively poor sources of Ca (0.22% +/- 0.03%), Mg (0.19% +/- 0.03%) and Cu (13 +/- 3.1 ppm). Pulses were low to medium sources of most minerals and good sources of Fe (1230 +/- 293 ppm). Oil seed cake/extractions (groundnut cake, cotton seed cake, soyabean meal, sunflower cake, safflower cake) and cereal by-products (rice polish, rice bran, wheat bran) were excellent sources of P (1.1% +/- 0.47% and 2.3% +/- 0.19%) and good sources of Zn (65 +/- 3.9 ppm and 66 +/- 10.7 ppm) and Fe (938 +/- 130 ppm and 662 +/- 126 ppm). Among the unconventional feeds screened, orange peel, sunflower heads, meat meal, rubber seed cake, spirulina algae and sea weeds contained plentiful Ca, Zn and Fe: tree leaves/top feeds (mulberry, erythrina, glyricidia, banana, subabul, groundnut haulms) were excellent sources of Ca (1.5% +/- 0.13%), Zn (120 +/- 22.9 ppm) and Fe (1033 +/- 133 ppm) but relatively poor sources of P. Soyabean husk, cocoa seed husk, rubber seed cake and meat meal were moderate to good sources of P (1.0% and 0.33%). The high Zn and Fe values of most feeds/fodders were probably due to soil contamination. This account of the micronutrient content of feed/fodder resources should help in strategic supplementation intended to alleviate local deficiencies.     

Bovine Mastitis in Selected Areas of Southern Ethiopia

A study on bovine mastitis, designed to determine the causal agents, prevalence of infection and impact of risk factors in three cattle breeds, was conducted in selected areas of southern Ethiopia. A total of 307 lactating and non-lactating cows, of which 162 were indigenous Zebu, 85 Jersey and 60 Holstein-Friesian, were examined by clinical examination and the California mastitis (CMT) test. Of these, 40.4% were positive by CMT and bacteriology for clinical or subclinical mastitis, with prevalence rates of 37.1% and 62.9%, respectively. Out of 1133 quarters examined, 212 (18.7%) were found to be infected, 83 (39.2%) clinically and 129 (60.8%) subclinically. The prevalence of mastitis was significantly higher in Holstein-Friesian than in indigenous Zebu, in non-lactating cows than in lactating cows, in the early lactation stage than in the mid-lactation stage, in cows with lesions and/or tick infestation on skin of udder and/or teats than in cows without this factor, and in the wet season than in the dry season. Mastitis increased with parity number (R = 0.9). Of 248 CMT and clinically positive udder quarter samples analysed microbiologically, 212 were culturally positive for known mastitis pathogens and 36 were negative. Of the 199 positive samples, Staphylococcus accounted for 39.2%, Streptococcus for 23.6%, coliforms for 14.1%, Micrococcus and Bacillus species for 8.0% each and Actinomyces or Arcanobacterium (Corynebacterium) for 7.0%. It was concluded that there was a high prevalence of clinical and subclinical mastitis, mainly caused by Staphylococcus aureus, Streptococcus agalactiae and Escherichia coli, in this study area.     

不同日粮氮水平对山羊氮代谢和微生物蛋白质合成的影响

本试验旨在探讨不同日粮氮水平对内蒙古白绒山羊氮代谢和微生物蛋白质合成(MCP)的影响,以达到提高氮利用率,减少环境污染和饲料资源的浪费。试验选用9只体况良好、体重为(43.83±2.95)kg,装有瘤胃瘘管的内蒙古白绒山羊,按体重随机分为3组,每组3只。日粮分为低氮7.5%、中氮10.5%、高氮13.5%3个氮水平。试验使用常规试验方法分析测定粪尿血液等生化指标,通过全收尿法和尿嘌呤衍生物法估测MCP。结果表明:随着氮水平增加,氨氮(NH3-N)浓度、氮摄入量、尿氮排出、尿中尿素氮(UUN)和MCP显著增加(P0.05),干物质采食量(DMI)显著降低(P0.01);沉积氮占总摄入氮的比例在中氮组最高,MCP在高氮组最高。综上所述,适当降低日粮氮水平可减少粪尿氮排放,提高反刍动物氮利用率。