“棘防E号”诱发小白鼠骨髓细胞的微核效应

采用微核试验观察“棘防E号”对小鼠骨髓细胞遗传毒性作用和量效关系。结果表明,“棘防E号”剂量为1/2 LD50(1 404 mg/kg)、1/4LD50(702 mg/kg)、1/8 LD50(352 mg/kg)时微核率分别为(140.27±4.71)%、(64.04±3.07)%、(42.01±1.99)%。其中1/2 LD50(1 404mg/kg)剂量组的微核率是阴性对照组的3.2倍,说明“棘防E号”的剂量超过1/2 LD50以上时对小白鼠骨髓细胞有一定的致突变作用。     

N-氨甲酰谷氨酸对小鼠骨髓细胞微核影响的试验研究

在预试验基础上,选用50只ICR小鼠随机分为5组,每组10只。N-氨甲酰谷氨酸混悬液经口服灌药的剂量分别为1/2 LD50(每千克体重2500 mg)作为高剂量组经口灌服染毒,中剂量组、低剂量组灌服剂量分别为1/4 LD50(每千克体重1 250 mg)、1/8 LD50(每千克体重625 mg),另设环磷酰胺阳性对照组与无菌水阴性对照组。按常规方法进行小鼠骨髓微核试验,采用30 h两次给药法,于第2次给药后6 h取材、制片,在油镜下观察微核,计算微核率。试验结果表明:N-氨甲酰谷氨酸对小鼠骨髓细胞的微核率无显著影响,表明N-氨甲酰谷氨酸无遗传毒性。     

沙咪珠利对小鼠精子畸形和骨髓细胞微核的影响

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。     

阿特拉津与氯氰菊酯联合染毒对鲫外周血红细胞微核和核异常的影响

将鲫分别暴露于不同浓度阿特拉津与氯氰菊酯混合溶液中,研究阿特拉津与氯氰菊酯联合染毒对鲫红细胞微核和核异常的影响,探讨其对鲫遗传毒性影响的变化规律和趋势。结果显示:阿特拉津与氯氰菊酯联合染毒对鲫红细胞微核率和核异常率的影响在一定条件下具有"浓度-时间-效应"关系。较低浓度阿特拉津(5.3 mg/l)与氯氰菊酯联合在染毒后期(第11 d)微核率增加显著,较高浓度阿特拉津(7.11、0.6 mg/l)与氯氰菊酯联合在染毒第8 d微核率增加显著。较高浓度阿特拉津(7.1、10.6 mg/l)-氯氰菊酯联合在短时间(第3 d)核异常率显著,较低浓度阿特拉津(5.3 mg/l)与氯氰菊酯联合在染毒后期(第11 d)核异常率增加极显著。由此得出,阿特拉津与氯氰菊酯联合对鲫具有潜在的遗传毒性效应,且随阿特拉津与氯氰菊酯联合浓度的增加和染毒时间的延长而增强。     

槲皮素作为饲料添加剂的急性毒性和致突变性评价

本试验采用急性毒性试验、污染物致突变性检测(Ames试验)、小鼠骨髓细胞微核试验和小鼠精子畸形试验对槲皮素作为饲料添加剂的安全性进行评价。结果表明:槲皮素半数致死剂量(LD50)>10 g/kg BW;Ames试验鼠伤寒沙门菌突变型各菌株在加与不加肝微粒体多氯联苯诱导剂(S9)情况下,经过2次试验结果均呈阴性;小鼠骨髓细胞微核试验结果为阴性,各槲皮素剂量组动物未见细胞毒性作用;小鼠精子畸形试验结果表明槲皮素剂量组与阴性对照组相比差异均不显著(P>0.05),且没有剂量反应关系。试验结果提示,槲皮素是一种安全的饲料添加剂。     

抗真菌药安特芬的小鼠微核试验与精子畸形试验研究

采用小鼠精子畸形试验和微核试验,对安特芬(特比萘芬)进行体内致突变性评价。微核试验:小鼠32只分4组(阴性组、阳性组、治疗量组、2倍治疗量组),连续两次灌胃,间隔24 h,末次灌胃6 h后处死小鼠,取股骨制成骨髓涂片,Gimsa染色,读取微核率;精子畸形试验:雄性小鼠32只分4组(阴性组、阳性组、治疗量组、2倍治疗量组),灌胃5 d,首次给药35 d后处死小鼠,取附睾制片,读取精子畸形率。试验结果显示,安特芬试验组小鼠微核发生率与阴性对照组差异不显著(P＞0.05),而阳性对照组微核发生率极显著高于阴性对照组(P＜0.01);安特芬试验组小鼠精子畸形率与阴性对照组差异不显著(P＞0.05),阳性对照组精子畸形率极显著高于阴性对照组(P＜0.01)。研究结果表明,新药安特芬在推荐剂量下无体内致突变作用。     

豆类丝核菌次级代谢产物的急性毒性与致突变性试验

通过经口急性毒性试验、小鼠骨髓微核试验和精子畸形试验对豆类丝核菌次级代谢产物的急性毒性和致突变性进行了研究.结果表明,以该代谢产物中苦马豆素的量计算,小鼠经口急性毒性试验的LD50为226.46mg/kg,LD50的95%可信限为158.49～323.59mg/kg,是治疗肿瘤剂量的14～84倍,属于实际低毒级药物.微核试验和精子畸形试验的各试验组与阴性对照组比较差异均不显著(P＞0.05),说明豆类丝核菌次级代谢产物无明显致突变性;各试验组之间比较差异均不显著(P＞0.05),说明微核的形成和精子畸形的形成与受试物无量效关系.结论:豆类丝核菌次级代谢产物是一种较安全的抗肿瘤药物.     

饲用五环三萜提取物的致突变试验北大核心

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。     

桔皮提取物有效成分的毒性研究

进行了桔皮提取物有效成分对小鼠急性毒性,眼刺激性和致突变性研究。结果,桔皮有效成分对小鼠口服LD_(50)为1578.0±268.2mg/kg,腹腔注射LD_(50)为379.7±36.0mg/kg;浓度为0.1％时对兔眼无刺激作用;Ames试验,桔皮有效成分对TA_(97)、TA_(93)、TA_(100)和TA_(102)的回变菌落数与其自发回变菌落数相近,无剂量效应关系;鼠骨髓细胞微核试验,各试验组微核率(1.8‰～2.3‰)均在正常范围内,精子畸形试验,各试验组精子畸形率(1.72％～2.04％)与阴性对照组无显著差异。表明桔皮提取物有效成分无致突变性。     

利用小鼠的遗传损伤检测竹炭板对甲醛的吸附作用

试验以不同剂量的气态甲醛对小鼠采用静式吸入染毒,利用小鼠的遗传损伤检测竹炭板对甲醛的吸附作用。结果发现:甲醛能引起小鼠骨髓细胞微核率升高,呈现一定的剂量-反应关系;中剂量组和高剂量组与对照组相比细胞微核率差异均有极显著性(P<0.01),具有统计学意义。高剂量甲醛经竹炭板吸附后,小鼠骨髓细胞微核率显著下降,差异有统计学意义(P<0.05,P<0.01),且随着吸附时间的增长,微核率降低。     

癸氧喹酯干混悬剂含量测定的改进

采用高效液相色谱法测定癸氧喹酯干混悬剂的含量,在2-250μg/mL范围内,峰面积的常用对数与进样量浓度的常用对数呈良好的线性关系,R^2=1(n=5),平均回收率为99.24%~99.51%,RSD在0.05%~0.28%。此方法分析时间短,样品前处理简便、定量结果准确,重现性好,结果满意,为其质量控制提供了依据。     

商会自治的基石——商会自治规范研究

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。     

猪毛色遗传的研究进展

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。     

中华人民共和国农业部公告 第267号

为贯彻落实《兽药生产质量管理规范》(简称《兽药GMP》),进一步推动兽药GMP实施进程,我部制定了《兽药生产质量管理规范检查验收办法》,现予公告。本公告自2003年6月1日起施行。附件:兽药生产质量管理规范检查验收办法二○○三年四月十日第一章 总则 第一条 为推动《兽药生产质量管理规范》(以下简称兽药GMP)的实施,规范兽药GMP检查验收工作,制定本办法。 第二条 农业部负责全国兽药GMP管理和检查验收工作;负责制修订兽药GMP检查验收管理规定;负责兽药GMP检查员队伍建设和监督管理工作,负责国际兽药贸易中GMP互认工作。 …     

鸡败血支原体垂直传播模式及其阻断方法

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。     

Comparison of 2 methods of centesis of the bursa of the biceps brachii tendon of horses

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.     

不同样本商品蜂蜜中硒含量的测定

用硝酸和高氯酸消化蜂蜜,使硒游离出来,在微酸性环境下,硒和2,3-二氨基萘(DAN)生成有较强荧光的物质,用环己烷萃取,在激发波长378nm,荧光波长518nm处测定其荧光强度。蜂蜜中硒含量范围:0.10～0.82μg/g。表明:蜂蜜应视为天然富硒营养品。     

乳酸杆菌益生作用机制的研究进展

乳酸杆菌作为益生菌广泛用于人和动物。本文综述了乳酸杆菌改善宿主健康的机制。乳酸杆菌可通过产生抗菌物质如乳酸、过氧化氢、细菌素,或者通过竞争营养或肠道黏附位点来抑制致病菌;通过诱导黏附素的分泌或阻止细胞凋亡而增强肠道的屏障功能,从而保护肠道。文章重点讨论了乳酸杆菌表面成分（表面蛋白、脂磷壁酸和肽聚糖）与肠道受体（Ｃ型凝集素受体、Ｔｏｌｌ样受体和 Ｎｏｄ样受体）,阐述了他们结合后启动免疫调节信号,调控肠道免疫功能以发挥改善健康作用的机制。     

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.