敌百虫对大鼠肝细胞[Ca~(2+)]_i、ATP酶及GJIC的影响

通过给大鼠肝细胞培养液中加入敌百虫(染毒终质量浓度分别为0,2,10,50 mg/L),探讨敌百虫对肝细胞内钙离子([Ca2+]i)、Na+-K+-ATPase、Ca2+-Mg2+-ATPase活性及间隙连接通讯(GJIC)的影响。结果显示,不同质量浓度敌百虫作用12 h,[Ca2+]i均极显著高于对照组(P0.01);随着染毒剂量的增加,Na+-K+-ATPase、Ca2+-Mg2+-ATPase活性及GJIC均显著或极显著下降(P0.05或P0.01)。说明敌百虫对肝细胞有明显的毒性作用,GJIC的下调可能与Ca2+浓度的升高和Na+-K+-ATPase、Ca2+-Mg2+-ATPase活性的下降有关。     

敌百虫对体外培养大鼠大脑皮质神经细胞凋亡的影响

为探讨敌百虫对大鼠大脑皮质神经细胞的毒性作用及机理,本研究在建立体外培养新生24h内SD大鼠大脑皮质神经细胞模型的基础上,在细胞培养液中添加0、5、20、80mg/L敌百虫染毒,在染毒后的不同时间测定细胞凋亡率、线粒体膜电位、细胞内[Ca2＋]i、ROS含量和ATP酶的变化。结果显示：①染毒12h,细胞凋亡率明显增加;②染毒12h,各染毒组线粒体膜电位逐渐降低,其中80mg/L组与对照组存在极显著差异（P〈0.01）;③染毒0.5h,各染毒组细胞内[Ca2＋]i显著高于对照组（P〈0.01）;染毒12h,各染毒组细胞内[Ca2＋]i呈下降趋势,但仍显著或极显著高于对照组（P〈0.05或P〈0.01）;④染毒12h和24h,细胞内ROS水平显著或极显著高于对照组（P〈0.05或P〈0.01）;⑤染毒12h,细胞Na＋-K＋-ATPase和Ca2＋-Mg2＋-ATPase活性逐渐降低,20、80mg/L组与对照组有极显著差异（P〈0.01）;上述指标的变化呈显著的剂量-效应关系。结果表明,低质量浓度敌百虫暴露可致大鼠大脑皮质神经细胞凋亡率和细胞内ROS含量升高,线粒体膜电位下降,细胞内钙离子超载且ATPase活性降低,提示细胞凋亡在敌百虫所致的大脑皮质神经细胞损伤过程中发挥主导作用。     

铅、镉及铅镉联合胁迫致雏鸡红细胞膜的损伤

150只7日龄公雏鸡分为10组,分别经口灌服或在体外培养红细胞中加入生理盐水、低浓度、中浓度及高浓度的铅、镉及铅镉混合溶液,研究铅、镉及铅镉联合对雏鸡红细胞膜Na+-K+-ATPase、Ca2+-Mg2+-ATPase活性的影响。结果表明:体内及体外红细胞铅、镉及铅镉联合染毒后,红细胞膜Na+-K+-ATPase、Ca2+-Mg2+-ATPase活性都有不同程度的降低(P0.01或P0.05),且呈明显的时间-剂量效应关系,中浓度联合染毒组与高浓度单独染毒组差异不显著(P0.05)。铅、镉、铅镉联合均对雏鸡红细胞膜有损伤作用,铅镉对红细胞膜的损伤有协同作用。     

钙稳态失衡在镉诱导大鼠大脑皮质神经细胞凋亡中的作用

用不同浓度醋酸镉（0、5、10、20μmol／L）以及细胞内钙离子螯合剂BAPTA-AM（10μmol／L）单独或联合作用于大鼠大脑皮质神经细胞12h,利用流式细胞仪检测细胞凋亡率、细胞内[Ca2＋];、活性氧（ROS）水平以及线粒体膜电位（△ψm）。结果显示,与对照组相比,各镉染毒组细胞凋亡率、细胞内[Ca2＋]i和ROS水平显著或极显著升高（P〈0．05或P〈0．01）,△ψm显著或极显著降低（P〈0．05或P〈0O．01）。BAPTA-AM联合组与相应镉染毒组相比,细胞凋亡率、细胞内[Ca2＋]i和ROS水平降低,△ψm升高,部分组间差异显著或极显著（P〈0．05或P〈0．01）。结果表明,镉可诱导大脑皮质神经细胞凋亡,细胞内钙稳态失衡在镉诱导大脑皮质神经细胞凋亡中起着重要作用,凋亡机理可能与细胞内钙超栽引起ROS水平升高和△ψm下降有关。     

内毒素致兔红细胞膜ATP酶活性改变及阳离子A的保护作用

为观察内毒素(ET)致兔红细胞膜(ECM)ATP酶(ATPase)活性变化及阳离子A(CA)的保护作用.采用定磷法分别测定正常对照组(Ⅰ组)、内毒素组(Ⅱ组)和阳离子A拮抗组(Ⅲ组)兔ECM的3种ATPase活性.结果除Na+-K+-ATPase、Mg2+-ATPase活性在0.5 h时与Ⅰ组比较无显著差异(P＞0.05)外,Ⅱ组3种ATPase活性在3.0 h内均显著增高(P＜0.01,P＜0.05),而5,7 h全部下降(P＜0.01);与Ⅲ组比较中,Ⅲ组除1 h时Mg2+-ATPase的活性无显著差异(P＞0.05)外,3种ATPase的活性均显著增强(P＜0.05,P＜0.01).结果表明ET可使ECM上3种ATPase活性先增高后降低,而CA对膜ATPase活性有明显保护作用.     

镉对胎鼠大脑皮质神经细胞凋亡与一氧化氮合酶基因mRNA转录的影响

为研究镉对胎鼠大脑皮质神经细胞凋亡与一氧化氮合酶基因mRNA转录的影响,用不同浓度醋酸镉(0、5、10、20 μmol/L)染毒胎鼠大脑皮质神经细胞12 h,流式细胞术检测细胞凋亡率,荧光显微镜观察镉对神经细胞凋亡的形态学影响,实时荧光定量PCR检测神经型一氧化氮合酶(nNOS)、诱导型一氧化氮合酶(iNOS)mRNA的转录水平.结果显示,与对照组相比,各染毒组细胞凋亡率呈现升高趋势;染镉组细胞核皱缩,染色质致密浓染,甚至核碎裂;5、10 μmol/L组nNOS mRNA转录水平显著升高(P＜0.05或P＜0.01),20 μmol/L组nNOS转录水平降低至对照组水平;20 μmol/L组iNOSmRNA转录水平极显著升高(P＜0.01).结果表明,镉可诱导大脑皮质神经细胞凋亡,并可调节nNOS和iNOS mRNA的转录.     

镉对大鼠大脑皮质神经细胞的氧化损伤及N-乙酰半胱氨酸的保护效应

为研究镉对新生大鼠原代大脑皮质神经细胞的脂质过氧化损伤及N-乙酰半胱氨酸(N-acetyl cysteine,NAC)的保护效应,对神经细胞用不同浓度(0,5、10、20 μmol/L)醋酸镉染毒和NAC(100 μmol/L)进行保护,检测细胞内活性氧(ROS)水平、谷胱甘肽过氧化物酶(GSH-Px)、超氧化物歧化酶(SOD)、过氧化氩酶(CAT)活性及丙二醛(MDA)含量.结果表明,与时照组比较,染毒组细胞内ROS水平、MDA含量和CAT活性极显著升高(P＜0.01),GSH-Px活性降低,20μmol/L组出现显著差异(P＜0.05);NAC保护组与相应染毒组比较,ROS水平、MDA含量和CAT活性呈不同程度降低,部分组间出现显著差异(P＜0.05);说明镉有促进神经细胞脂质过氧化的作用,NAC可提高神经细胞的抗氧化能力,对镉暴露所致的脂质过氧化损伤有一定的保护作用.     

甲状腺粉诱导大鼠甲亢过程中心肌微粒体ATP酶活性变化及丹参酮ⅡA磺酸钠的保护作用

给大鼠口服甲状腺粉,每只8mg/d,连续30 d,大鼠出现甲亢体征,检测心肌微粒体Na+、K+-ATPase,Ca2+-ATPase和Mg2+-ATPase活性.结果:甲状腺粉组以上各项指标分别为7.6士1.3,16.5±1.8和21.8士2.2μmol Pi/gHb/h,均明显低于丹参酮ⅡA磺酸钠组和对照组(P＜0.01);丹参酮ⅡA磺酸钠组和对照组比较无显著性差别(P＞0.05).上述结果表明,甲状腺粉诱导甲亢过程中心肌微粒体ATPase活性降低;丹参酮Ⅱ A磺酸钠对ATPase活性具有明显保护作用.     

促红细胞生成素在铅镉联合胁迫致雏鸡贫血中的作用

为研究促红细胞生成素(EPO)在铅镉联合胁迫致雏鸡贫血中的作用,选用60只7日龄公雏鸡,平均分为对照组、铅组、镉组和铅镉组,每日经口灌服染毒,分别于第1、3、7天染毒后,检测雏鸡血液学指标和网织红细胞数量,并进行骨髓象的观察及红细胞膜ATP酶活性、红细胞渗透脆性和血清EPO含量的检测。结果表明铅镉单独染毒使雏鸡发生贫血,网织红细胞数量先增加后降低,骨髓象增生先活跃后受抑制,红细胞膜Na+-K+-ATPase、Ca2+-Mg2+-ATPase活性降低,红细胞渗透脆性增加,血清EPO含量先增加后降低,铅镉联合染毒也表现出上述变化,且较单独染毒组变化明显(P<0.05或P<0.01)。本研究证实铅、镉单独及联合染毒均可引起雏鸡发生贫血,贫血类型主要为再生障碍性和溶血性贫血,且铅与镉存在显著的协同效应;EPO参与了铅镉联合胁迫致雏鸡的贫血作用。     

镉对鸡卵巢NO代谢及ATP酶活性的影响

为了探讨镉对鸡卵巢发育的毒性机制,在饲料中分别加入CdCl2140和210mg/kg,建立亚慢性镉中毒模型,分别在试验第20、40、60天取卵巢,检测NO含量,以及NOS、Na+-K+-ATPase、Mg2+-ATPase和Ca2+-ATPase活性。结果显示,卵巢组织NO含量和NOS活性升高,Na+-K+-ATPase、Mg2+-ATPase和Ca2+-ATPase活性降低,且存在时间-剂量效应。表明镉中毒可引起卵巢组织NO代谢紊乱及ATPase活性降低,进而损伤卵巢。     

Comparison of in vitro and in situ methods in evaluation of forage digestibility in ruminants

The objective of this study was to compare the application of different in vitro and in situ methods in empirical and mechanistic predictions of in vivo OM digestibility (OMD) and their associations to near-infrared reflectance spectroscopy spectra for a variety of forages. Apparent in vivo OMD of silages made from alfalfa (n = 2), corn (n = 9), corn stover (n = 2), grass (n = 11), whole crops of wheat and barley (n = 8) and red clover (n = 7), and fresh alfalfa (n = 1), grass hays (n = 5), and wheat straws (n = 5) had previously been determined in sheep. Concentrations of indigestible NDF (iNDF) in all forage samples were determined by a 288-h ruminal in situ incubation. Gas production of isolated forage NDF was measured by in vitro incubations for 72 h. In vitro pepsin-cellulase OM solubility (OMS) of the forages was determined by a 2-step gravimetric digestion method. Samples were also subjected to a 2-step determination of in vitro OMD based on buffered rumen fluid and pepsin. Further, rumen fluid digestible OM was determined from a single 96-h incubation at 38°C. Digestibility of OM from the in situ and the in vitro incubations was calculated according to published empirical equations, which were either forage specific or general (1 equation for all forages) within method. Indigestible NDF was also used in a mechanistic model to predict OMD. Predictions of OMD were evaluated by residual analysis using the GLM procedure in SAS. In vitro OMS in a general prediction equation of OMD did not display a significant forage-type effect on the residuals (observed - predicted OMD; P = 0.10). Predictions of OMD within forage types were consistent between iNDF and the 2-step in vitro method based on rumen fluid. Root mean square error of OMD was least (0.032) when the prediction was based on a general forage equation of OMS. However, regenerating a simple regression for iNDF by omitting alfalfa and wheat straw reduced the root mean square error of OMD to 0.025. Indigestible NDF in a general forage equation predicted OMD without any bias (P ≥ 0.16), and root mean square error of prediction was smallest among all methods when alfalfa and wheat straw samples were excluded. Our study suggests that compared with the in vitro laboratory methods, iNDF used in forage-specific equations will improve overall predictions of forage in vivo OMD. The in vitro and in situ methods performed equally well in calibrations of iNDF or OMD by near-infrared reflectance spectroscopy.     

大庆市羊东毕吸虫病流行病学调查

对大庆市羊东毕吸虫病的流行病学进行了调查研究。结果表明，大庆有3种东毕吸虫，即程氏东毕吸虫（O.cheni)、土耳其斯坦东毕吸虫（O.turkestanica)和土耳斯坦东毕吸虫结节变种（O.turkestanican var.thuberculata)；中间宿主螺类有1种，即卵萝卜螺；东毕吸虫病在大庆分布很广，所调查的4区2县均有发生，羊东毕吸虫平均感染率分别为50．33％，平均死亡率为21．12％，大庆羊急性病例发病时间为8月上旬至10月下旬，慢性病例为11月上旬至翌年2月中旬。     

中国圈养野生动物疫苗使用调查

2005年对中国动物园协会单位中的18家动物园饲养野生动物疫苗免疫情况进行调查。受调查动物园在野生动物疫苗使用和动物种类方面具有一定的代表性。调查结果显示动物园动物现共使用18类36种疫苗,预防31种疫病。其中哺乳动物使用14类24种疫苗,预防24种疫病;禽类使用4类12种疫苗,预防7种疫病。使用范围最广的有禽流感、犬瘟热疫苗等、新城疫疫苗、猫瘟热疫苗等。共有24目58科动物接种疫苗,其中食肉动物类1目8科,食草动物类3目9科,杂食动物类2目3科,禽类18目38科。研究结果提示应加强动物园之间疫病信息交流、防疫资源的利用、疫病监测和研究,加大对动物园动物疫病的研究投入,逐步建立动物园动物统一的防疫规程。     

ELISA试验在防制猪伪狂犬病中的应用

猪伪狂犬病是由伪狂病病毒(Pseudorabies virus PRV)引起的急性传染病。其特征是成年猪常为隐性感染，可有流产、死胎、呼吸系统症状，新生仔猪除神经症状外还可侵害消化系统，并伴大批死亡。本病已经给全世界的养猪业造成严重的损失，我国许多地区已报道该病。为进一步探讨该病的控制、净化措施，我们对12个养猪场共856分血清采用美国嗍公司的ELISA试剂盒进行了抗体检测。     

Use of cyclocryotherapy in management of glaucoma in dogs

In 5 cases of glaucoma (2 from trauma, 2 from narrowed drainage angles, 1 secondary to lens extraction), cyclocryotherapy was used to control intraocular pressure. In all cases the intraocular pressure decreased, with the usual result being a cosmetic and painless but blind eye.     

Estimate of economic impact of fowl cholera in turkeys in Georgia in 1986

Information gathered from cases of fowl cholera (FC) in commercial turkey flocks through case records, flock records, and telephone and mail surveys was used to estimate disease costs. The cost to the Georgia commercial turkey industry in 1986 from preventive measures, treatment of outbreaks, and production losses from the disease was estimated at $634,545. The cost of FC per kg of live production was estimated to be $0.015.     

Occurrence of MRSA in pigs and in humans involved in pig production--preliminary results of a study in the northwest of Germany

In 2007, 678 pigs of all age groups out of 347 different farms from Lower Saxony and Northrhine-Westphalia and 86 persons occupationally exposed to pigs were investigated for their nasal colonisation with methicillin-resistant Staphylococcus areus (MRSA) by the Field Station for Epidemiology of the University of Veterinary Medicine Hannover and the Robert Koch-Institute. At the individual animal level, a frequency of positive results of 13% (n = 85 positive animals) and at the herd level, a frequency of positive results of 18% (n = 62 positive herds) were found. All isolates were assigned to the Multilocus Sequence Typing Type ST398. Within MRSA-positive herds, there were more MRSA-negative than MRSA-positive animals. Among the occupationally exposed persons (veterinarians, laboratory personnel and meat inspection personnel), 20 persons (23%) showed a nasal colonisation with MRSA ST398. A quite strong association between the intensity of the contact to pigs with the frequency of nasal colonisation in the occupationally exposed persons was detected. None of the animals or the humans nasally colonised by MRSA ST398 showed any clinical symptoms of a staphylococcal infection. Conclusions are drawn on the herd and intra-herd prevalence of the nasal colonisation of pigs with MRSA ST398 in pigs, but especially on which questions need to be addressed by further research.     

2017年西藏拉萨市家禽禽流感抗体水平检测

为了解西藏拉萨市家禽禽流感抗体水平,2017年8月随机选择免疫过H5禽流感疫苗的8个规模养殖场、2个散养户、3个活禽交易市场,共13个群体,采集1 041份家禽血清样品进行H5、H7、H9亚型禽流感HI抗体检测。结果显示：H5亚型禽流感免疫抗体合格率为45.73%,H7、H9亚型抗体阳性率分别为21.13%、52.64%;养殖场、散养户和活禽交易市场的不同亚型抗体水平存在较大差异,规模化养殖场的H7亚型抗体阳性率最高（29.92%）,活禽市场的H5、H9亚型阳性率最高（78.16%、79.31%）,散养户的所有亚型抗体阳性率均最低。结果表明,拉萨市H5亚型禽流感疫苗免疫效果较差,特别是散养户,疫病发生风险较高,H7、H9亚型疑似自然感染率较高,应进一步查明原因,及时采取相应的措施,防止疫情发生。