Pharmacokinetic Behaviour of Albendazole Sulphoxide Enantiomers in Male and Female Sheep

Benzimidazole anthelmintic drugs are widely used in veterinary practice. Albendazole sulphoxide (ABZSO) is a benzimidazole drug with two enantiomers, as a consequence of a chiral centre in the sulphoxide group. The kinetics of these enantiomers were studied in male and female sheep. Plasma samples were obtained from the animals between 0.5 and 72 h after oral administration of 7.5 mg/kg of a racemic formulation of ABZSO (total-ABZSO). After a liquid–liquid extraction, the samples were analysed by HPLC to determine the concentrations of total-ABZSO and of the sulphone metabolite (ABZSO₂). During the chromatographic analysis, the ABZSO peak was collected and reanalysed by an HPLC technique using a Chiral AGP column to quantify the enantiomeric proportion therein. After kinetic analysis, the AUCs obtained for the (+)-ABZSO were 5.8 and 4.0 times higher than those for the (–)-ABZSO in male and female animals, respectively. The mean residence times were 23.4 and 16.1 h for (+)-ABZSO and 22.2 and 17.4 h for (–)-ABZSO for male and female animals, respectively. The only significant difference between the sexes (p<0.05) was in the T _max of the (–)-ABZSO. Comparing both enantiomers within each sex, significant differences were found in all the kinetic parameters. Finally, no kinetic differences were found between sex for total-ABZSO or ABZSO₂.     

Genomic and Pathogenic Studies on a Glycoprotein E Variant Field Isolate of Bovine Herpesvirus 1

Glycoprotein E-negative (gE–) laboratory strains of bovine herpesvirus 1 (BHV-1) were recently introduced as novel marker vaccines, allowing serological discrimination between vaccinated and naturally infected animals on the basis of lack or presence of antibodies against gE epitopes. The applicability of this approach is based on the genetic stability of the gE. However, mutant field variants of BHV-1 with a variable response in anti-gE ELISA have been isolated. The molecular characterization of a gE variant field isolate (Salwa strain) is presented here. By comparing the gE nucleotide and amino acid sequences of the Salwa strain with those of the wild strain Jura, ten mutated bases were found in the gE strain of Salwa, six of which alter the amino acid sequence, leading to changes in five amino acids. Both strains caused respiratory disease in experimentally infected calves, but Salwa generated slightly milder signs. Both viruses were excreted in nasal and ocular discharges, and were reactivated by dexamethasone treatment. In conclusion, the rather close similarities observed in the gE gene structure and pathogenicity features of the gE mutant and of the wild strain of BHV-1 confirm the genetic stability of gE. The findings indicate that the Salwa isolate is virulent, but less virulent than wild strains. Our data support the use of gE-negative marker vaccines in eradication programmes.     

Prevalence of bovine herpesvirus-4 infection in cats in Central Michigan

The gammaherpesvirus bovine herpesvirus-4 (BHV-4) has been isolated from a wide variety of animals, including lions and domestic cats. Although BHV-4 antibodies have been detected in normal cats and cats with urinary disorders, the epidemiology and pathogenic role of BHV-4 in cats is unknown. The purpose of this study was to determine the prevalence of BHV-4 antibodies and viral nucleic acid in a population of free-roaming cats. Plasma and peripheral blood leukocyte samples were collected from 52 male and 52 female free-roaming cats impounded at a regional animal control facility in Central Michigan. Plasma concentrations of BHV-4 antibodies were measured with an indirect fluorescent antibody test. Peripheral blood leukocyte DNA was isolated, and a 2-stage polymerase chain reaction with heminested primers delineating a conserved portion of the BHV-4 glycoprotein B gene homologue was used to amplify BHV-4-specific DNA sequences. BHV-4 antibodies were detected in 38 (73%) male and 23 (44%) female cats. Seropositive cats were significantly more likely to be male than female (odds ratio = 3.22; P = .007). Cell-associated viremia was detected in 17 (33%) male and 11 (21%) female cats. Of the 61 seropositive cats, 23 (38%) had a detectable viremia; only 5 (12%) seronegative cats had detectable viremia. Seropositive cats were significantly more likely to be viremic than seronegative cats (OR = 4.30: P = .009). Our results suggest that BHV-4 infection may be more widespread in certain cat populations than previously reported. Furthermore, many cats seropositive for BHV-4 antibodies have a concurrent cell-associated viremia.     

Molecular and Pathogenicity Characteristics of Phytophthora nicotianae Responsible for Root Necrosis and Wilting of Pepper (Capsicum annuum L.) in Tunisia

Isolates of Phytophthora from pepper, produced in Tunisia, were characterised according to molecular and pathogenicity criteria. Polymerase chain reaction amplification of the ITS1 region in the ribosomal DNA resulted in different sized fragments. The pepper isolates and P. nicotianae yielded a fragment of 310bp that distinguished it from P. capsici with a fragment of 270bp. The ribosomal RNA gene amplicons of both internal transcribed spacers and the 5.8 S of the pepper Phytophthora and P. nicotianae were digested with 8 endonucleases. The patterns generated, with the 2 enzymes that cut, were identical for both taxa. This molecular analysis corroborated the morphological and biological characteristics and suggests strongly that the isolates of Phytophthora from pepper belong to the species P. nicotianae. Inoculation of pepper, tomato, eggplant and tobacco plants with the isolates of P. nicotianae from pepper showed they were highly pathogenic on pepper but not on tobacco, while their pathogenicity was weak on tomato and eggplant and was associated with atypical symptoms not observed in the field. These pathogenicity tests suggest that pepper isolates of P. nicotianae are particularly adapted to their host and may thus constitute a forma specialis of P. nicotianae.     

三江源区高寒草甸草场放牧牦牛采食量的测定

试验选用约2．5岁公牦牛8头，在三江源地区玉树县的高寒草甸草场，应用4N盐酸不溶灰分法（4N—AIA）和木质素标记物法测定了不同物候期（青草期和枯黄期）放牧牦牛日采食量及牧草营养成分的消化率。结果表明：2．5岁牦牛在青草期、枯黄期的100kg体重日采食量分别为3．69kg和2．96kg，差异极显著（P〈0.01）；其不同物候期的千物质消化率分别为65．70％、61．72％（P〉0．05），粗蛋白的消化率为62．25％、39．00％（P〈0．01），粗脂肪为49．36％、58．18％（P〈0．05），ADF的消化率为57．88％、62．67％（P〉0．05），NDF的消化率为69．09％、79．38％（P＜0．01）。     

北极狐多巴胺受体D1基因的克隆测序

为了获得北极狐多巴胺受体D1基因序列,给北极狐自咬行为提供理论依据。采用聚合酶链式反应方法,从北极狐耳组织扩增出多巴胺受体D1基因的部分外显子序列,并对其进行克隆测序,将该序列提交到Genebank上。Genebank中的Blast分析表明,北极狐多巴胺D1受体基因与家狗(Canis familiaris)的同源性为99%,与牛(Bos taurus)的同源性为93%,与人(Homo sapiens)的同源性为92%。     

复方黄柏颗粒剂在小鼠体内的药代动力学

为探讨复方黄柏颗粒剂有效成分-盐酸小檗碱在小鼠体内的药动学特征,按25 g/kg(相当于盐酸小檗碱10.95 mg/kg)的剂量经口给予小鼠复方黄柏颗粒剂,用高效液相色谱法检测用药后不同时间血浆中盐酸小檗碱的质量浓度,研究在小白鼠体内的药物动力学。结果表明口服复方黄柏颗粒的有效成分-盐酸小檗碱在小鼠体内的药时数据符合开放性二室模型,动力学方程为C=17.8e-0.859 81t 14.51e-0.636 1t。主要药代动力学参数:t1/2α为(0.81±0.07)h,t1/2β为(5.25±2.96)h,t1/2Ka为(0.76±0.05)h,AUC0→∞为(3.389 3±0.437 4)mg.L-1.h,CL/F为(3.281 8±0.446 3)L/h,Vd/F为(13.65±22.38)L/kg,Tpeak为(1.617 19±0.056 50)h,Cmax为(1.149 98±0.056 04)μg/mL。     

氧气对低地鸡蛋胚胎死亡和孵化率的影响

通过模拟常压低氧和高海拔增氧孵化试验，研究了氧气浓度对低地良种鸡蛋胚胎死亡率和孵化率的影响。死亡胚胎的分布用2阶段增长模型分析。模拟2900m海拔常压低氧孵化增加了胚胎后期死亡率，使孵化率降低到接近2900m海拔实际孵化率水平；2900m海拔全期增氧孵化可以有效降低前期和后期胚胎死亡率，大大提高孵化率；阶段增氧孵化也能不同程度提高孵化率，改变胚胎死亡分布，其中效果最好的为前期增氧组。结果说明低氧是影响2900m海拔鸡蛋孵化的最主要因素。     

伊氏锥虫安锥赛抗药性相关基因-TbTA1的分析

为探讨伊氏锥虫对安锥赛抗药性的分子机理，以布氏锥虫对砷剂药物抗药性相关的TbTA1基因设计引物，以55℃、57℃、60℃、63℃和65℃不同退火温度，分别从伊氏锥虫敏感株的cDNA和基因组DNA中扩增出TbTA1基因的全长序列，但是从安锥赛抗药株伊氏锥虫的cDNA和基因组DNA中都未扩增出TbTA1基因，这表明基因TbTA1可能与伊氏锥虫安锥赛抗药性的产生有关。伊氏锥虫与布氏锥虫的，TbTA1基因序列比较，它们有10个碱基不同，即第88位的G（T.e）-A（T.b）、第144位的T（T．e）-C（T．b）、第224位的C（T．e）-T（T．b）、第471位的C（T.e）-T（T.b）、第472位的A（T．e）-G（T.b）、第549位的G（T．e）-T（T．b）、第1008位的C（T．e）-T（T.b）、第1033位的A（T．e）-G（T．b）、第1293位的A（T．e）-G（T．b）和第1384位的T（T．e）-C（T．b），其中有5个碱基所编码的氨基酸不同，即Val^30（T.e）Ile（T．b）、Ala^75（T．e）-Val（T．b）、Ile^158（T．e）-Val（T．b）、Thr^345（T．e）-Ala（T．b）和Ser^462（T.e）-Pro（T．b），这表明伊氏锥虫与布氏锥虫的TbTA1差异可能是它们的种间差异。     

新孢子虫dNcSRS2重组蛋白间接ELISA的建立及其应用

利用新孢子虫体外重组表面蛋白dNcSRS2蛋白作为包被抗原，对各项条件进行优化，确定判定标准，建立了检测新孢子虫血清抗体的间接ELISA方法。经对多例血清检测表明，所建立的诊断试剂盒重复性好、特异性强、灵敏度高，与进口的IFAT及两种商品化ELISA试剂盒的检测结果相比较，符合率均达到92％以上。应用建立的ELISA方法对236份奶牛血清的新孢子虫抗体进行检测，阳性率为22％。这是国内首次利用重组蛋白建立的诊断试剂盒，该方法的建立将为牛新孢子虫病的诊断与流行病学调查提供有效的技术手段。