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角蛋白是生物材料中角质含量最丰富的结构蛋白，是动物被毛、羽毛、角、蹄和人类头发及指甲等组织的主要成分。角蛋白生物材料由于其丰富的来源和优越的生物学功能，是组织工程中最有前景的天然高分子化合物之一，在生物相容性、降解性、组织愈合和再生等多个方面已被开展研究。目前，从生物材料中提取角蛋白的技术有化学水解法、微生物消化水解法、离子液体溶解法、微波辐射法、蒸汽爆炸技术、热水解或过热法等。提取加工的角蛋白材料已用于药物传递、伤口愈合和组织修复工程等多个生物医学领域，具有广阔的应用前景。论文就角蛋白生物特性、结构、材料来源以及提取分离技术等进行总结，并论述角蛋白生物材料在生物医学领域中的应用，以期为角蛋白及其相关应用研究提供参考。 相似文献
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壳聚糖在畜牧兽医领域的应用前景 总被引：2，自引：0，他引：2
刘博涛 《畜牧兽医科技信息》2007,(2):21-23
壳聚糖是一种天然无毒,具有良好组织相容性与生物降解性的高分子生物材料。已广泛应用于工业、农业、食品、医药等各个方面。本文就壳聚糖的制备与提取、生物活性以及在畜牧兽医领域的应用作一简要的综述,并对其应用前景做出展望。 相似文献
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苦豆子总碱涂膜剂安全性试验研究 总被引：1，自引：0，他引：1
为研究苦豆子总碱涂膜剂在预防和治疗奶牛乳房炎方面的安全性,选用皮肤完好的健康家兔,观察家兔对苦豆子总碱涂膜剂皮肤刺激反应症状,并根据皮肤刺激反应的评分标准进行评分;选用皮肤完好的健康豚鼠进行试验,观察豚鼠对苦豆子总碱皮肤变态反应症状,根据皮肤刺激反应的评分标准进行评分。结果表明:苦豆子总碱涂膜剂皮肤刺激反应积分均值最大值为1.33,属于轻刺激性。根据皮肤变态反应的评分标准,计算所得受试物试验组去除激发受试物后24 h和48 h时的致敏率分别为25%和8.3%,属于轻度致敏强度。试验结果提示,苦豆子总碱涂膜剂临床用药安全,此结论为苦豆子总碱用于奶牛乳房炎的预防与治疗提供了依据。 相似文献
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将家蚕丝素蛋白通过化学接枝反应制备具有抗凝血功效的硫酸化丝素蛋白医用材料。经动物的热原试验、皮内刺激试验、皮肤致敏试验、急性毒性试验以及体外溶血试验,对硫酸化丝素蛋白进行生物相容性评价。结果表明:3只注射受试硫酸化丝素蛋白溶液后的家兔体温仅升高0.2、0.3、0.1℃,未引起热原反应;家兔试验部位和周边组织出现的少量红斑或红肿在72 h后自然消退,无刺激反应;涂抹受试溶液后连续3 d,小鼠的试验部位和周边组织均未出现红斑、水肿等致敏反应;小鼠腹腔注射受试溶液后生理活动及生长正常,无毒性反应;受试溶液在体外溶血试验中无溶血现象。各项试验结果提示:硫酸化丝素蛋白材料有良好的生物相容性,具有在生物医学材料领域应用的前景。 相似文献
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兽用疫苗不同于一般的药品,更不同于一般工业产品。动物疫苗生产涉及生物材料和生物学过程,有其固有的生物易变性和特殊性,其质量必须具有理想的安全性、有效性和可接受性,从原材料投产到产品出厂一系列因素都对动物疫苗生产起着决定性作用。兽用生物制品的特殊性决定了对兽用生物制 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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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
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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