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树突状细胞及其在抗感染免疫中的作用 总被引:1,自引:0,他引:1
树突状细胞 (Dendritic cell,简称DC) ,以其在成熟期中伸出树枝状突起 (伪足 )而得名 ,其真实涵义 ,除形态特征外 ,还应包括 :膜表面能高效表达MHC Ⅱ类分子、能移行至淋巴器官和刺激初始型T细胞 (Naive T cells)增殖活化 ,并具有一些相对特异性的表面标志 (如各种CD分子 )。DC在 2 0世纪 70年代就由Steinman首次报道。由于DC在组织中含量极微 ,细胞来源困难 ,限制了对其生物学特性等方面的深入研究。直到 1 992年 ,Steinman实验室首先建立了用重组粒细胞巨噬细胞集落刺激因子 (G… 相似文献
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杜洛克猪及新姜曲海基础母本氟烷基因的检测 总被引:4,自引:0,他引:4
猪应激综合征 (Porcinestresssyndrome,PSS)是PSE或DFD肉的直接原因。控制PSS的基因称为氟烷基因 (Halothane)。进一步研究表明猪兰尼啶受体(Ryanodinereceptor,RYR1)基因突变是导致PSS的主要原因。RYR1基因的C183 4 →T ,使受体蛋白Arg615→Cys,从而引起其结构和功能的改变 ,这种改变导致了应激状态下Ca2 大量非正常释放 ,激活过量肌糖元酵解 ,引起PSE肉。未突变的纯合子HalNN 以及杂合子HalNn个体抗应激能力强 ,突变的纯合子Halnn对… 相似文献
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气管环组织培养 (TOC)是用于鸡传染性鼻气管炎病毒 (TRTV)分离、鉴定和血清学检查的有效方法 ,Buy、McDongall、Cook等应用TOC已成功地分离到TRTV。我们曾用TOC鸡胚成纤维细胞 (CEF)、绿猴肾细胞 (VERO)对可疑的鸡传染性鼻气管炎病鸡进行野毒株分离 ,证明TOC比CEF、VERO细胞更适于TRTV的分离和鉴定。经过鸡胚传代、电镜观察和中和试验等初步鉴定为鸡传染性鼻气管炎病毒 ,并通过理化特性和病原学的特性作进一步研究。1 材料与方法1 .1 病毒及血清标准株 :NL 7784株。分离株 :上海… 相似文献
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中国饲料成分及营养价值表 总被引:1,自引:0,他引:1
《中国饲料》2002,(22)
TABLESOFFEEDCOMPOSITIONANDNUTRITIVEVALUESINCHINA表 4 .矿物质及维生素含量MineralsandVitamins序号 中国饲料号CFN 饲料名称FeedName 钠Na( % ) 氯Cl( % ) 镁Mg( % ) 钾K ( % ) 铁Fe(mg/kg)铜Cu(mg/kg)锰Mn(mg/kg)1 4- 0 7- 0 2 78玉米corngrain 0 .0 1 0 .0 4 0 .1 1 0 .2 936 3.4 5.82 4 - 0 7- 0 2 88玉米corngrain 0 .0 1 0 .0 4 0 .1 1 0 .2 936 3.4 5.834 - 0 7- 0 2 79玉米corngrain 0 .0 … 相似文献
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MD-2(related lipid recognition protein,ML蛋白质)是哺乳动物中一类重要的脂类识别蛋白,可以识别革兰氏阴性杆菌细胞壁的主要组分脂多糖(Lipopolysaccharides,LPS),二者形成复合体后被跨膜蛋白质受体TLR4(Toll like receptor 4)识别,进而启动下游免疫信号通路。在鳞翅目昆虫家蚕中,研究发现LPS可以诱导其体内抗菌肽的表达。为了研究家蚕中参与LPS识别的跨膜蛋白及信号通路,论文通过生物信息学分析家蚕基因组数据库中的MD-2类似基因,通过对其结构域分析,发现家蚕Bm PP具有与哺乳动物中的MD-2相似的保守结构域。同时抽提脂肪体RNA,通过RT-PCR获得Bm PP基因,将其克隆至p IEx-4载体上转染家蚕Bm12细胞,48 h后Western-blotting检测发现BmPP成功表达并分泌到细胞培养基中。研究结果将为进一步研究LPS诱导家蚕细胞发生免疫反应的通路研究提供材料。 相似文献
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用从健康猪胸腺提取的 T 淋巴细胞作抗原免疫 B A L B/c 小鼠。取免疫鼠脾细胞与 S P2/0 骨髓瘤细胞融合,经 3 次克隆,共获得 10 株稳定分泌抗体的杂交瘤细胞。以细胞反应特异性试验、 W esternblotting 分析、流式细胞计数( F C M )等方法,确定了对猪 T 细胞表面抗原特异性反应的单抗( M c Abs),其中 2 D9 、3 B1 0 可以识别相对分子质量 50 000 的 T 细胞膜蛋白,能标记 96% 的胸腺细胞、89% 的外周血 T 淋巴细胞、87% 的脾 T 淋巴细胞,其特性与猪 C D2 抗原相符;另一株 1 G1 2 可识别相对分子质量 63 000 的 T 细胞膜蛋白,能标记 98% 的胸腺细胞、91% 的外周血 T 淋巴细胞、78% 的脾 T 淋巴细胞,其特性与猪 C D5 抗原相符。 相似文献
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禽类免疫系统知识大多来自对鸡的研究.鸡和哺乳动物的免疫机制存在许多相似之处,但两者也存在重要的差异性.禽类受到抗原刺激产生抗体和细胞免疫应答,主要有三类抗体:IgM、IgG(亦称IgY)、和IgA,通过基因转换获得抗体多样性.T淋巴细胞是细胞免疫的主要效应细胞,禽类T细胞有两种不同的分化途径即α/β和γ/β.类似于哺乳动物T细胞受体机制,通过结合和连接机制产生禽类T细胞多样性.同哺乳动物T细胞一样,禽类T细胞参与MHC限制的辅助细胞和细胞毒性细胞功能.天然效应细胞由自然杀伤细胞(NK细胞)和抗体依赖细胞的细胞毒性作用(ADCC)介导.近来,禽类一些细胞因子得到克隆和表达,许多病毒引起鸡免疫抑制.目前我们感兴趣的是如何了解免疫抑制的机制以及采取何种策略增强商业鸡群的免疫应答能力. 相似文献
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《中国饲料》2000,14(22)
表 1 饲料描述及常规成分Feeddescriptionandproximatecomposition饲料名称feedname饲料描述description中国饲料编号CFN干物质DM(% )0 1玉米corngrain成熟 ,高蛋白质 4-0 7-0 2 7886 .00 2玉米corngrain成熟 ,GB/T 17890 -19991级 4-0 7-0 2 7986 .00 3玉米corngrain成熟 ,GB/T 17890 -19992级 4-0 7-0 2 80 86 .00 4高粱sorghumgrainNY/T 1级 ,成熟 4-0 7-0 2 72 86 .00 5小麦wheatgrainNY/T 2级 ,混合小麦… 相似文献
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bcl-2在鸡马立氏克氏病肿瘤中的表达 总被引:1,自引:0,他引:1
用来克亨 S P F鸡复制马立克氏病( Marek’s disease, M D)肿瘤模型,取肿瘤和相应正常组织,液氮保存。 A G P C( Acid Guanidinium Thiocyanate Phenol Chloroform )法提取组织总 R N A( T R N A),紫外测定其浓度,甲醛变性胶电泳观察其纯度。将一个含鸡 bcl2 1.2 kb 片段的质粒( P T T B C1),经转化扩增,提取质粒 D N A,限制性内切酶( R E)消化,回收纯化bcl2片段,放射性 α32 P标记,制成探针。通过 Northern 分子交杂检测 M D 肿瘤组织中bcl2 的表达,并与相应的正常组织比较。结果:①鸡 M D 肿瘤组织和相应正常组织中均有 bcl2 的表达;② M D 肿瘤组织中bcl2 的表达显著高于相应的正常组织。结合已进行的凋亡研究表明,bcl2 表达产物通过阻遏细胞凋亡促进 M D 淋巴瘤的形成。 相似文献
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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
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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
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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
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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
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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