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《中国饲料》2017,(3)
本文选用Ames试验、小鼠骨髓细胞微核试验和精子畸形试验三种短期测试组合探究胍基乙酸是否具有致突变作用。结果发现:Ames试验结果显示,胍基乙酸在8~5000μg/皿,有或无代谢活化系统(S9)时,对鼠伤寒沙门氏菌TA_(97)、TA_(98)、TA_(100)、TA_(102)四种试验株均没有诱变性;骨髓细胞微核试验结果显示,胍基乙酸在1250~5000 mg/kg体重剂量内经口染毒后,各剂量组小鼠骨髓细胞中嗜多染红细胞(PCE)微核率与阴性对照组比较均无显著性差异(P0.05);小鼠精子畸形试验结果显示,胍基乙酸在1250~5000 mg/kg体重剂量内经口染毒后,各剂量组小鼠精子畸形率与阴性对照组比较均无显著性差异(P0.05)。结果表明,三个致突变试验结果均为阴性,胍基乙酸为非致突变物质。 相似文献
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《饲料工业》2017,(20):6-10
研究通过致突变性检测(Ames)试验、骨髓微核试验以及精子畸形试验,以进一步确定槲皮素作为饲料添加剂在体内和体外致突变性的潜力。体内骨髓微核试验采用昆明种小鼠50只(雌、雄各半),随机分5组,每组10个重复。精子畸形试验采用昆明种雄性小鼠50只,随机分5组,每组10个重复;体外试验采用鼠伤寒沙门氏菌突变型菌株(TA97、TA98、TA100和TA102)进行。在肝微粒体多氯联苯诱导剂(9 000×g Supernatant,S9)干预和不干预的情况下,槲皮素各剂量组对鼠伤寒沙门氏菌(TA97、TA98、TA100和TA102)的回复突变菌落数与阴性对照组无显著差异(P0.05);同时,槲皮素各剂量组雌雄小鼠的骨髓微核率和嗜多染红细胞/红细胞(Polychromatic erythrocyte/Red blood cell,PCE/RBC)值与阴性对照组无显著差异(P0.05);槲皮素各剂量组雄性小鼠精子畸形率与阴性组无显著差异(P0.05)。结果表明,在本试验条件下,槲皮素无致突变性和细胞毒性,并且进一步证明槲皮素是一种安全的饲料添加剂。 相似文献
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《中国兽医杂志》2016,(5)
为了评价甜菊糖苷中的主要成分之一莱鲍迪苷A的致突变作用,在2 500~4μg/皿范围内,对莱鲍迪苷A(含量≥97%)进行了Ames试验,灭菌水作为阴性对照;以5.0 g/kg体重、2.5 g/kg体重和1.25 g/kg体重剂量进行了小鼠骨髓细胞微核试验和小鼠精子畸形试验,以40 mg/kg环磷酰胺为阳性对照,生理盐水为阴性对照。结果 Ames试验中,莱鲍迪苷A对TA97、TA98、TA100和TA102菌株的回变菌落数均小于阴性对照组的两倍,且未见剂量-反应关系,Ames试验阴性;小鼠骨髓细胞微核试验和小鼠精子畸形试验均为阴性。表明莱鲍迪苷A在试验剂量下无致突变作用。 相似文献
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试验旨在通过鼠伤寒沙门氏菌回复突变试验(Ames试验)、小鼠骨髓细胞微核和精子畸变试验,评价五环三萜提取物作为饲料添加剂是否具有潜在的致突变性。Ames试验中受试物剂量组为0.008、0.040、0.200、1.000、5.000 mg/皿,另设阴性对照(灭菌水、DMSO)及阳性对照组,每个处理分别设有代谢活化系统(+S9)和无代谢活化系统(-S9)两个系列,测定试验菌的回变菌落数。小鼠骨髓细胞微核试验中受试物剂量组采用1.25、2.50、5.00 g/kg灌胃给药,并设阳性对照(环磷酰胺)及阴性对照(1%羧甲基纤维素液),共给药2次,每次间隔24 h,测定小鼠骨髓细胞微核率。精子畸变试验中受试物剂量组采用1.25、2.50、5.00 g/kg灌胃给药,设阳性对照(环磷酰胺)及阴性对照(1%羧甲基纤维素液),共给药5次每次间隔24 h,于第1次给药5周后处死小鼠,统计精子畸形率和畸形种类。结果显示:不同剂量组与对照组相比,Ame试验中平均回变菌落数均在溶剂组2倍以内,无剂量-反应关系;骨髓细胞微核率和精子畸变率均无显著影响(P>0.05);致突变试验结果均为阴性。研究表明,受试物五环三萜提取物不具有致突变作用。 相似文献
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按常规方法,研究了不同剂量胡杨花粉对小鼠的致突变作用。小鼠骨髓细胞微核试验、小鼠精子畸形试验结果均表明,与阴性对照组比较,各受试剂量组微核率、精子畸形率差异均无统计学意义．提示胡杨花粉对小鼠无致突变作用。 相似文献
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为评价沙咪珠利的安全性,对其进行了小鼠精子畸形和骨髓细胞微核试验研究。选择健康ICR小鼠随机分为受试物高、中、低剂量组,阳性对照组和阴性对照组,进行精子畸形试验和骨髓细胞微核试验,计算精子畸形率和微核率。结果显示,受试物各剂量组精子畸形率与骨髓细胞微核率与阴性对照组比较,差异不显著(P0.05),与阳性对照组比较,差异有统计学意义(P0.01)。表明沙咪珠利对小鼠精子和骨髓细胞微核无影响,不具有遗传毒性。 相似文献
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荚膜甲基球菌蛋白（Methylococcus capsulatus bacteria meal,MBM）拟开发为新饲料原料。本研究旨在通过遗传毒性研究和被动过敏试验评价其毒理学安全性,为其未来的应用奠定基础。本研究包括四个试验：鼠伤寒沙门氏菌回复突变（Ames）试验采用平板掺入法,每皿剂量在0.625～10.000 mg范围内,采用TA97、TA98、TA100、TA102和TA1535五种菌株进行回复突变试验;小鼠骨髓细胞微核试验和精子畸形试验均设2 500、5 000、10 000 mg/kg三个MBM剂量组,微核试验采用30 h两次给药法,精子畸形试验连续染毒5 d,分别在既定的时间采样制片;大鼠被动皮肤过敏试验设250、500、1 000 mg/kg三个MBM剂量组,制备抗血清后背部皮内注射致敏,24 h和/或48 h后进行抗原激发,考察蓝色反应斑直径。所有试验均根据要求设置阴性、阳性对照组。结果表明：在有或无代谢活化系统结果（S9）时,MBM的鼠伤寒沙门氏菌回复突变（Ames）试验结果均为阴性;小鼠骨髓细胞微核和精子畸形试验结果均为阴性;大鼠皮肤被动过敏试验结果为阴性。说明在... 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