共查询到20条相似文献，搜索用时 93 毫秒
1.
为了研究胶质细胞原性神经营养因子(GDNF)对体外培养小鼠精原干细胞增殖与分化的影响,试验采用差速贴壁法分离小鼠精原干细胞(SSCs)和支持细胞(sertoli),以sertoli为饲养层接种精原干细胞,用免疫荧光染色法对精原干细胞进行鉴定,并将精原干细胞分为2组,试验组培养基中加入GDNF,对照组不加,测定精原干细胞的生长增殖情况,检测精原干细胞生长周期。结果表明:共培养6,9,12,15天时,试验组精原干细胞吸光度值明显高于对照组(P<0.05或0.01)。随着共培养时间的延长,试验组精原干细胞S期染色质含量逐渐增多,然后又逐渐下降,开始另一个分裂周期;与试验组比较,对照组精原干细胞S期染色质含量增长缓慢(P<0.05)。说明GDNF能促进体外分离培养的小鼠精原干细胞的更新增殖。 相似文献
2.
3.
4.
精原干细胞是体内唯一的能在细胞水平进行识别并增殖、分化及调控的成体干细胞,是位于精曲小管基膜上,既能自我更新,维持自身群体数量恒定,又能定向分化产生精母细胞的一类原始精原细胞,其前体是原始生殖细胞(primord ial germ cells,PGCs)。近年来,随着精原干细胞鉴定,体外培养及冻存等技术的发展,精原干细胞的应用成为可能。文章对精原干细胞形态特征、分离纯化、体外培养及影响因素等进行综述。1精原干细胞的形态、特性及其增殖分化精原干细胞相对数量极少,仅占生殖细胞的0.02%~0.03%。睾丸中大部分的精原细胞并非干细胞,而是处于分化… 相似文献
5.
《畜牧与兽医》2016,(7):71-75
探讨一种新的体外培养精原干细胞的方法,为进一步研究精原干细胞增殖与凋亡提供依据。采用组合酶消化、差速贴壁法分离精原干细胞,并设计了支持细胞条件培养基、胶质细胞源性神经营养因子(GDNF)处理培养基以及对照培养基3种培养体系,应用细胞活力分析仪检测精原干细胞数量以及活性,精原干细胞标记蛋白c-kit受体和磷酸酶染色技术进行鉴定,激光共聚焦显微镜技术检测细胞增殖核抗原(PCNA)和BCL-2家族蛋白Bax和Bcl2表达的变化。结果:应用组合酶消化和差速贴d壁法得到了纯度70%以上的精原干细胞;在体外培养7 d以内,PCNA的表达条件培养基组明显好于GDNF处理组以及对照组,Bcl2的表达条件培养基组高于GDNF组和对照组,Bax的表达条件培养基组低于GDNF组和对照组。研究表明在7 d内体外培养精原干细胞,条件培养基明显促进细胞增殖,抑制细胞的凋亡。 相似文献
6.
7.
8.
小鼠精原干细胞的形态结构及其细胞化学和免疫组化特性 总被引：18，自引：1，他引：17
应用光镜、电镜观察了 ７～８ ｄ 小鼠精原干细胞的形态结构特点;应用细胞化学、免疫组织化学方法研究了体外培养小鼠精原干细胞的细胞化学和免疫组织化学特性。结果显示,精原干细胞呈圆形,直径（９±１） μｍ ,核大,呈圆形或轻微卵圆形,胞质较少;核内常染色质占绝对优势,异染色质极少;胞质内核糖体、线粒体较丰富,其他细胞器不发达;精原干细胞 Ａ Ｋ Ｐ染色呈阳性或强阳性,胞质内脂滴很少或没有;精原干细胞表达特异的 ｃｋｉｔ 受体;体外培养的小鼠精原干细胞常呈不完全的胞质分裂,细胞间由细胞间桥相连而呈链状或团状的细胞群丛,细胞群常由偶数细胞组成。 相似文献
9.
10.
奶山羊睾丸组织冷冻保存及复苏后精原干细胞的分离培养 总被引：1，自引：0，他引：1
以关中奶山羊为材料,比较了2种玻璃化冷冻法和1种慢速冷冻法对睾丸组织保存的效率,复苏后发现3种冻存方法均有较高的成活率(超过50%),其中玻璃化Ⅱ组达65%以上,培养及检测后均有精原干细胞存活,在体外培养可以形成胚胎干细胞样克隆,其表达精原干细胞和多能性干细胞的相关特异性标记:碱性磷酸酶(AP)、CD49f、CD133、C-Myc、Oct4和Klf4阳性,证明睾丸组织冷冻可以提供一种有效的奶山羊精原干细胞的保存方法。试验中所使用的低温保存方法简便易行,效果良好,表明这些方法可为癌症治疗等造成的无精症及少精症等不育症患者的医治以及一些珍稀濒危物种和优良畜禽的生殖细胞保存提供一种简捷有效的途径。 相似文献
11.
12.
13.
魏静 《四川畜牧兽医学院学报》2009,(4):28-32
在现代法律秩序中,商会自治规范是制定法的基础和必要的补充,甚至在某些方面替代了制定法;商会自治规范主要包括商会组织规范、行为规范、惩罚规范以及争端解决规范等;其效力仅及于其内部成员;商会自治规范和制定法之间存在冲突,但也存在整合的基础。 相似文献
14.
本文概述了猪的毛色类型、猪的毛色遗传模式,着重综述了猪毛色基因分子基础的研究进展,指出存在问题并就未来发展方向做了思考。 相似文献
15.
16.
以国际标准强毒Ｒ株人工感染非免疫产蛋鸡,定时扑杀,分别从鼻窦、眶下孔、气管、肺、气囊、卵巢和输卵管分离ＭＧ,并收集感染鸡所产蛋分离ＭＧ。结果表明,人工感染４８小时后上、下呼吸道及肺已被全面感染,９６小时气囊已被感染,１２０小时输卵管已能分离到ＭＧ,卵巢始终分离不到ＭＧ。人工感染鸡自１４４小时便能在其所产蛋中分离出ＭＧ。药物治疗能在７２小时内消除感染,油乳剂苗则需２４天后逐渐降低蛋内ＭＧ分离率,药物卵内注射、种蛋药浴、高温处理均能杀死卵内ＭＧ,但以研制的种蛋浸泡剂药浴效果为最好。 相似文献
17.
REASONS FOR PERFORMING STUDY: Centesis of the bicipital bursa using an 8.9 cm long spinal needle has been reported but the alternative of employing a 3.8 cm long hypodermic needle requires validation. OBJECTIVE: To compare the efficacy of 2 different methods of centesis of the bicipital bursa and to evaluate the usefulness of ultrasonographic imaging to determine the location of solution administered when centesis of the bursa is attempted. METHODS: For Trial 1, 6 clinicians, who had no previous experience of centesis of the bicipital bursa, attempted to inject a solution composed of an aqueous radiopaque contrast medium and physiological saline solution (PSS) into the bicipital bursae of 2/12 horses using the previously described distal approach to inject one bursa and a proximal approach to inject the contralateral bursa. The bicipital tendon and bursa were examined ultrasonographically before and after injection; and both shoulders were examined radiographically to identify the location of the medium. In Trial 2, another 6 clinicians, also with no previous experience of centesis, repeated Trial 1, using 6 horses, but the radiopaque contrast medium was mixed with air instead of PSS. RESULTS: Accuracy of centesis using the proximal approach was 39% and that of the distal approach 28%. Ultrasonographic examination of the shoulder allowed the location of solution and air to be accurately predicted in all 12 shoulders examined. CONCLUSIONS: Clinicians who have had no previous experience performing centesis of the bicipital bursa are unlikely to be successful in centesis using either approach. Radiographic examination after injecting a radiopaque contrast medium may be necessary to assess the success of centesis especially if bursal fluid is not obtained during centesis. Injecting air along with the radiopaque contrast medium provides more accurate ultrasonographic confirmation of centesis and better radiographic definition than does injection without air. 相似文献
18.
19.
20.
Effects of size of ingestively masticated fragments of plant tissues on kinetics of digestion of NDF
Ingestively masticated fragments were collected and sized via sieving. Different sizes of esophageal masticate and ruminal digesta fragments, and ground fragments of larger masticated pieces were incubated in vitro, and undigested NDF remaining at intervals of up to 168 h of incubation was determined. The ruminal age-dependent time delay (tau) for onset of digestion of NDF was positively correlated (P < 0.004) with the mean sieve aperture estimated to retain 50% of the fragments between successive sieve apertures (MRA). Degradation rate of potentially degradable NDF (PDF) and level of indigestible NDF were not related (P > 0.10) to MRA of masticated and ground fragments. Estimates of tau were positively related to MRA, with slopes of bermudagrass < corn silage < ruminal fragments of corn silage. It was concluded that fragment size-, and consequently, ruminal age-dependent onset of PDF degradation of a mixture of different fragment sizes results in an age-dependent rate of degradation of the more rapidly degrading of two subentities of PDF. Models are proposed that assume a tau before onset of simultaneous degradation of PDF from two pools characterized as having gamma-modeled age-dependency and age-constant rates. The ruminal age-dependent pool seems to be associated with the faster-degrading pool, and its rate parameter increases with range in MRA in the population of fragments. Conceptually, the ruminal age-dependent rate parameter for PDF degradation seems to represent a composite of several effects: 1) effects of the size-dependent tau; 2) range in MRA of the population of ingestively masticated fragments; and 3) subentities of PDF that degrade via more rapid age-dependent rates compared with subentities of PDF that degrade via age-constant rates. The estimated fractional rates of ruminative comminution of ingestively masticated fragments (0.060 to 0.075/h) were of a magnitude similar to the mean fractional rates of PDF digestion (0.030 to 0.085/h), which implies that ruminative comminution may be first-limiting to fractional rate of PDF digestion. The in vivo roles of ingestive and ruminative mastication of fragments on PDF degradation must be considered in any kinetic system for estimating PDF digestion in the rumen. These results and others in the literature suggest that the rate of surface area exposure rather than intrinsic chemical attributes of PDF may be first-limiting to degradation rate of PDF in vivo. 相似文献