RT-PCR检测和区分猪传染性胃肠炎病毒和猪呼吸道冠状病毒的研究

根据猪传染性胃肠炎病毒（TGEV）和猪呼吸道冠状病毒（PRCV）的基因组核苷酸序列，在S基因（纤突蛋白基因）5′端保守区设计了一对引物P3／P4，该对引物在TGEV扩增跨幅约为2.4kb；而PRCV由于在此区域存在一约0.6kb碱基缺失，扩增跨幅约为1.8kb。用引物P3／P4对TGEV Miller株、Purdue株和PRCV AR310株分别进行RT－PCR，根据RT－PCR扩增片段大小可以直接区分TGEV和PRCV。用引物P3／P4与引物P1／P2作Nested-PCR,提高了该RT－PCR的特异性和敏感性，建立的RT－PCR可为临床上诊断TGEV及调查我国是否存在PRCV感染提供可靠的鉴别手段。     

RT-PCR方法快速诊断猪传染性胃肠炎

根据猪传染性胃肠炎病毒（TGEV）标准毒株（Purdue-115）的ORF6（N基因）的基因序列，设计俣成了一对引物Li01/Li02用反转录聚俣酶链反应（RT－PCR）技术对发病猪的粪便进行检测。结果得到与预期大小相一致的约1174bp(N基因）的PCR产物，与从参照毒株TGEV TH－98扩增出的片段大小相一致。进一步用限制性内切酶进行分析，发现从发病猪火花名扩增出的N基因与参照毒株TH－98株具有相同的限制性内切酶图谱，从而证实本病例致病病毒为TGEV。     

猪传染性胃肠炎病毒SYBR GreenⅠ模式实时定量RT-PCR检测方法的建立及初步应用

登录GenBank下载猪传染性胃肠炎病毒（TGEV）的N基因序列,依据保守区设计一对特异性引物,采用SYBR GreenⅠ随机结合渗入法,建立检测猪传染性胃肠炎病毒的实时定量RT—PCR检测方法,成功构建了检测TGEV的标准DNA模板,循环阈值（Ct）与标准DNA模板在1．0×10-1．0×10^7拷贝／μl浓度范围内呈良好的线性关系,相关系数为0．9985。该方法用于检测TGEV具有很高的特异性,其敏感性与常规PCR相比可以提高100倍,可以用于猪传染性胃肠炎病毒的快速检测。用建立的检测方法对82份临床样品进行了检测,和普通PCR检测结果100％相符。     

检测猪流行性腹泻病毒的R-PCR方法的建立

根据猪流行性腹泻病毒 (PEDV)的N基因自行设计和合成了一对可扩增长度为 641bp目的片段的引物 ,成功地建立了检测的猪流行性腹泻病毒的RT PCR方法。对猪轮状病毒 (PRV)、猪传染性胃肠炎病毒 (TGEV)的RT PCR检测结果均呈阴性。对PEDV JS株的RT PCR产物的序列分析表明 ,与CV777株的同源性为 97 3 %。     

应用多重RT-PCR方法检测158例猪粪样中的两种冠状病毒

根据GenBank上发表的猪流行性腹泻（PEDV）和猪传染性胃肠炎（TGEV）基因序列，针对其PEDVM（膜蛋白）基因保守区及TGEV的S基因（纤突蛋白基因）5’端保守区，各设计一对引物，可特异扩增出目的条带大小分别为467bp和1062bp。用上述两对引物对同一样品中的PEDV和TGEV可进行鉴别检测，对猪的其它病毒和细菌的PCR扩增结果均为阴性。敏感性测定结果表明：该双重PCR方法能检出PEDV1pg、TGEV0．1pg的模板。同时采用建立的多重RT-PCR及韩国引进的PEDV和TGEV病毒抗原快速诊断试剂盒检测结果显示：此多重RT-PCR方法特异性强，且较快速试剂盒更加敏感。应用多重RT-PCR对158份临床猪粪样的检测结果表明：我国很多猪场普遍存在TGEV和PEDV，尤其以PEDV污染更为严重，感染率达53．2％，但双重感染率较低，仅为4，4％。     

细粒棘球绦虫感染终末宿主检测方法的评价

对细粒棘球绦虫感染家/牧犬常用的检测方法开展比对试验,并予以评估。对人工感染细粒棘球绦虫试验犬含卵粪样在不同时段用饱和蔗糖液(1.28 g/m L)漂浮虫卵,镜检;经化学药物驱虫,收集人工感染试验犬驱虫前、后粪样,流行病学调查中收集的家/牧犬粪样,用粪抗原抗体夹心ELISA检测试剂盒检测,同时,对检出的家/牧犬阳性粪样,再用虫卵漂浮法复检;通过氢溴酸槟榔碱下泻法检查家/牧犬感染细粒棘球绦虫虫体,同时,对下泻犬粪样用粪抗原检测和虫卵漂浮法进行复检。饱和蔗糖液漂浮虫卵最佳时段为2 h,可检出虫卵量与其他时段差异显著(P0.05);人工感染犬驱虫前、后粪样经粪抗原检测,OD值差异极显著(P0.01);对12 288份家/牧犬粪样进行粪抗原检测,阳性样品991份,感染率为8.1%(991/12 288),对991份阳性粪样进行虫卵漂浮法复检,检查出54份粪样中含虫卵。经下泻法检查312只家牧犬,其中,262只犬下泻,检查出27只犬感染细粒棘球绦虫成虫;对262份下泻犬粪样进行粪抗原检测,阳性29份;对262份下泻犬粪样用虫卵漂浮法检查,仅14份粪样检出虫卵。犬粪抗原抗体夹心ELISA检测犬感染细粒棘球绦虫可及时区分驱虫前、后感染状况,其更为安全、快捷、准确。     

TGEV-PEDV二重RT-PCR检测方法的建立及应用

本试验旨在建立能同时检测猪传染性胃肠炎病毒(TGEV)和猪流行性腹泻病毒(PEDV)的二重RT-PCR检测方法。首先根据Gen Bank收录的TGEV和PEDV的基因序列,设计扩增猪传染性胃肠炎病毒(TGEV)、猪流行性腹泻病毒(PEDV)的特异性引物,然后通过优化二重PCR的体系建立一个二重RT-PCR检测方法。用该方法对临床收集的10份粪便样品进行检测,初步表明本研究建立的二重PCR方法具有良好的特异性和灵敏度,能用于临床诊断及流行病学调查。     

猪传染性胃肠炎病毒SYBR Green I模式实时定量RT-PCR检测方法的建立及初步应用

登录GenBank下载猪传染性胃肠炎病毒(TGEV)的N基因序列,依据保守区设计一对特异性引物,采用SYBR GreenⅠ随机结合渗入法,建立检测猪传染性胃肠炎病毒的实时定量RT-PCR检测方法,成功构建了检测TGEV的标准DNA模板,循环阈值(Ct)与标准DNA模板在1.0×10-1.0×107拷贝/μl浓度范围内呈良好的线性关系,相关系数为0.9985。该方法用于检测TGEV具有很高的特异性,其敏感性与常规PCR相比可以提高100倍,可以用于猪传染性胃肠炎病毒的快速检测。用建立的检测方法对82份临床样品进行了检测,和普通PCR检测结果100%相符。     

猪传染性胃肠炎病毒国内分离株S基因克隆及与国外分离株的同源性比较

用猪睾丸细胞增殖并扩增猪传染性胃肠炎病毒（TGEV）国内分离株TH－98，根据基因库中已发表的TGEV S基因cDNA序列，利用Oligo软件设计并合成2对引物，进行逆转录聚合酶合酶链反应（RT－PCR），扩增出2.3kb和2.1kb2个片段，即Sa与Sb。将Sa与Sb先后插入到pUC18质粒载体上的EcoRⅠ和PstⅠ多克隆位点上，构建了重组质粒pUC-S，根据TGEV S基因位点和pUC18的物理图谱，用相应的限制性内切酶进行酶进行酶切及套式PCR方法鉴定，分析，证明克隆的pUC-S为TGEV S基因，同时对pUC-S进行序列测定分析，并与来自美国，英国和日本的5个毒株进行核苷酸及编码氨基酸同源性比较，证明了S基因的高度保守性。     

猪传染性胃肠炎病毒SYBR Green I模式实时定量RT-PCR检测方法的建立及初步应用

登录GenBank下载猪传染性胃肠炎病毒(TGEV)的N基因序列,依据保守区设计一对特异性引物,采用SYBR Green I随机结合渗入法,建立检测猪传染性胃肠炎病毒的实时定量RT-PCR检测方法,成功构建了检测TGEV的标准DNA模板,循环阈值(Ct)与标准DNA模板在1.0×10-1.0×107拷贝/μ1浓度范围内呈良好的线性关系,相关系数为0.9985.该方法用于检测TGEV具有很高的特异性,其敏感性与常规PCR相比可以提高100倍,可以用于猪传染性胃肠炎病毒的快速检测.用建立的检测方法对82份临床样品进行了检测,和普通PCR检测结果100%相符.     

Feline intracranial neoplasia: retrospective review of 160 cases (1985-2001)

The purpose of this study was to determine the frequency of different tumor types within a large cohort of cats with intracranial neoplasia and to attempt to correlate signalment, tumor size and location, and survival time for each tumor. Medical records of 160 cats with confirmed intracranial neoplasia evaluated between 1985 and 2001 were reviewed. Parameters evaluated included age, sex, breed, FeLV/FIV status, clinical signs, duration of signs, number of tumors, tumor location(s), imaging results, treatment, survival times, and histopathologic diagnosis. Most of the cats were older (11.3 +/- 3.8 years). Primary tumors accounted for 70.6% of cases. Metastasis and direct extension of secondary tumors accounted for only 5.6 and 3.8% of cases, respectively. Twelve cats (7.5%) had 2 or more discrete tumors of the same type, whereas 16 cats (10.0%) had 2 different types of intracranial tumors. The most common tumor types were meningioma (n = 93, 58.1%), lymphoma (n = 23, 14.4%), pituitary tumors (n = 14, 8.8%), and gliomas (n = 12, 7.5%). The most common neurological signs were altered consciousness (n = 42, 26.2%), circling (n = 36, 22.5%), and seizures (n = 36, 22.5%). Cats without specific neurological signs were common (n = 34, 21.2%). The tumor was considered an incidental finding in 30 (18.8%) cats. In addition to expected relationships (eg, meninges and meningioma, pituitary and pituitary tumors), we found that lesion location was predictive of tumor type with diffuse cerebral or brainstem involvement predictive of lymphoma and third ventricle involvement predictive of meningioma.     

The Prevalence and Intensity of Helminth and Coccidial Infections in Dairy Cattle in Central Kenya

A survey of gastrointestinal parasite infections of young (<6 months old), immature (6–12 months old) and adult (>12 months old) dairy cattle on 16 farms in Kiambu District, Kenya was conducted during a dry season (September 1991 to January 1992) and during a wet season (March to July 1992). The survey was based on monthly coproparasitological examination of cohorts and worm counts in tracer calves. The effects of age, sex, farm and season on the prevalence and intensity of helminth and coccidial infections were determined. Faecal egg and oocyst counts revealed that the overall prevalences were: strongyles (including trichostrongyles) (85.5%), liver flukes (Fasciola gigantica) (34.0%), coccidia (30.9%) and tapeworms (9.6%). Eight species of the protozoan Eimeria were identified, the most prevalent species being E. bovis and E. zuernii. The most prevalent nematode genera were Haemonchus, Cooperia, Oesophagostomum and Trichostrongylus. Season, farm and age of the animals had a significant (p<0.05) influence on the intensity of infection with strongyles, liver flukes and coccidia, whereas the sex of the animals had no significant (p>0.05) effect on the prevalence or intensity of infections. A higher intensity of infection with strongyles and coccidia was found in the wet season than in the dry season (p<0.05). The age-specific intensity was in the following order: for strongyles, immature animals of 6–12 months of age had the highest egg counts, followed by young calves and adults. Calves had significantly (p<0.05) higher oocyst counts than immatures or adults. Liver fluke egg counts did not differ significant (p>0.05) between immatures and adult cattle.     

Hypothalamic dopamine is required for salsolinol‐induced prolactin secretion in goats

The aim of the present study was to clarify the relationship between hypothalamic dopamine (DA) and salsolinol (SAL) for the secretion of prolactin (PRL) in goats. SAL or thyrotropin‐releasing hormone (TRH) was intravenously injected into female goats treated with or without the D₂ DA receptor antagonist haloperidol (Hal), which crosses the blood‐brain barrier, and the PRL‐releasing response to SAL was compared with that to TRH. PRL‐releasing responses to SAL, Hal, and Hal plus SAL were also examined after a pretreatment to augment central DA using carbidopa (Carbi) and L‐dopa. The PRL‐releasing response to Hal alone was greater than that to SAL or TRH alone. The PRL‐releasing response to Hal plus SAL was similar to that of Hal alone. In contrast, the PRL‐releasing response to Hal plus TRH was greater than that to TRH or Hal alone. The treatment with Carbi plus L‐dopa inhibited SAL‐ and Hal‐induced PRL secretion. The inhibition of the PRL‐releasing response to SAL disappeared when SAL was injected with Hal. These results indicate that the mechanisms underlying the SAL‐induced PRL response differ from those of TRH, and suggest that hypothalamic DA and its synthesis is associated in part with SAL‐induced PRL secretion in goats.     

Laboratory diagnosis of respiratory diseases of cattle

The authors describe the procedure of laboratory diagnosis for bovine respiratory diseases: direct diagnosis by isolation and for identification of bacteria or viruses and indirect diagnosis by serological methods. They specify the restraints and limits of this diagnosis and the significance results which are obtained and connected with knowledge of anamnestic information.     

The effect of peri-parturient anthelmintic treatment on the productivity of dairy cattle in subtropical western India

Trials with fenbendazole (Panacur, Hoechst India Ltd) were carried out on two commercial farms in subtropical western India to study the response and economics of nematode treatment in adult dairy cows. Milk yield, lactation length, time to first oestrus and worm egg output were monitored in treated and control groups. Treatment reduced the egg count considerably. Treated cows produced 142 litres more milk over 100 days (p<0.05), with extension of lactation length and advancement of time to first oestrus. The economic gain in terms of milk yield far outweighed the cost of anthelmintic used.     

An Evaluation of the Acceptability as Forage of Some Nutritive and Antinutritive Components and of the Dry Matter Degradation Profiles of Five Species of Ficus

The suitability of five species of Ficus, F. mucoso, F. thonningii, F. polita, F. religiosa and F. benjamina, for feeding ruminant livestock was studied. The nutritive and antinutritive components were determined and the acceptability of the forages to livestock was assessed using a cafeteria method in 8 adult small ruminants. Also, the degradation potential of the dry matter of the five Ficus species was investigated using 3 fistulated sheep. The crude protein (CP) content of the Ficus species varied significantly (p < 0.05), ranging from 130 to 180 g/kg DM. The content of neutral detergent fibre (NDF) also varied significantly (p < 0.05), ranging from 650 to 710 g/kg DM. The organic matter (OM) contents did not differ significantly (p > 0.05), having a mean value of 916 g/kg DM. The concentrations of tannin, saponin, phytic acid and oxalic acid were low. The acceptability of the forage was similar for four of the species but poor for F. polita. The extent of DM degradation varied significant among the Ficus species, the ranking order being F. benjamina > F. thonningii > F. mucoso > F. religiosa > F. polita.     

Macrolides and lincosamides

Macrolides and lincosamides are first choice bacteriostatic antibiotics used in veterinary dermatology. The main antibiotics in these classes are erythromycin, lincomycin, clindamycin and tylosin. They are well absorbed if given orally and are able to penetrate well into infected skin. Their spectrum of action comprises bacteria commonly associated with skin infections, including staphylococci. Their main disadvantages are the rapid development of bacterial resistance and occasional gastroenteric upset, most often seen with erythromycin. More recently developed macrolides, such as azithromycin and clarithomycin, are bactericidal, have a larger spectrum of action, a longer endurance, less resistance and may be given once a day instead of two or three times daily.