共查询到20条相似文献,搜索用时 46 毫秒
1.
葡聚糖作为一种免疫增强剂可以通过增强细胞的吞噬作用和增强免疫相关酶的活性来提高水生动物的非特异性免疫性能,提高抗病能力,其在水生动物的免疫系统上起着重要的作用。本文对葡聚糖对水生动物免疫功能的影响作一综述。 相似文献
2.
壳聚糖主要由甲壳素脱乙酰得到,其在抗生物活性、激活淋巴细胞以及提高动物免疫力方面都有一定的促进作用。很多研究表明,在基础饲料中添加一定量的壳聚糖能有效增强异育银鲫、黄颡鱼、草鱼、中华鳖等等水产动物的非特异性免疫力。本文就甲壳素及其衍生物对水产动物的免疫性能的影响做一综述。 相似文献
3.
4.
壳聚糖对动物免疫调节作用的研究进展 总被引:1,自引:2,他引:1
壳聚糖是一种天然、绿色的环保高分子物质,具有可生物降解性、可食用性及生物相容性等特点,且安全无毒,对环境无公害。许多研究表明,壳聚糖对动物机体免疫功能具有多方面的调节作用,既可有效提高非特异性免疫功能,也可对特异性免疫功能产生调节作用,并且存在剂量效应。在机理研究方面,目前的研究报道较少,且多为体外免疫细胞培养试验。从现有的报道看,壳聚糖调节免疫功能的机理可能是通过调控免疫细胞一氧化氮和花生四烯酸的生成等途径来实现的。 相似文献
5.
6.
鱼类生长发育与疾病抵抗力密切相关,而营养物质在鱼类疾病抵抗力及其免疫调控中发挥着重要作用.已有研究表明部分营养物质可通过雷帕霉素靶蛋白(TOR)和核因子E2相关因子2(Nrf2)信号途径调控鱼类免疫器官细胞因子产生,降低鱼类免疫器官氧化损伤,从而保证其结构完整性和功能正常,进而提高鱼类非特异性和特异性免疫力,增强鱼类疾病抵抗力.本文就部分氨基酸(蛋氨酸和异亮氨酸)、脂溶性维生素(维生素A)、水溶性维生素(维生素B1、吡哆醇、泛酸、胆碱和肌醇)以及营养性添加物(蛋氨酸羟基类似物)等营养物质与鱼类疾病抵抗力、非特异和特异性免疫防御、免疫器官生长发育、结构完整性和抗氧化防御、细胞因子及其相关信号途径之间关系的研究进展作一综述. 相似文献
7.
益生菌是良好的免疫激活剂,可以提高内源宿主的防御机能,有效提高抗干扰素和巨噬细胞的活性,通过产生抗体提高噬菌作用活性等刺激免疫激发机体体液免疫和细胞免疫,并增强宿主对病原的非特异性免疫,辅助免疫清除,调节宿主对潜在病原的免疫调节作用,减弱宿主对过敏原的过敏性反应,增强机体的免疫力和抗病力。 相似文献
8.
9.
10.
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