猪繁殖与呼吸综合征未免疫猪群的抗体消长规律研究

为研究未免疫猪繁殖与呼吸综合征病毒疫苗的猪场的PRRSV抗体消长规律,试验采集A、B、C三个规模化猪场共147头猪的血液样本,分离血清,用IDEXX试剂盒检测血清中的PRRSV抗体。检测结果表明A、B、C三个猪场的猪群具有相似的PRRSV抗体消长规律,即哺乳仔猪体内存在PRRSV抗体,随着猪周龄的增长,PRRSV抗体水平降低,PRRSV抗体水平下降到最低后,随着PRRSV的感染,机体产生免疫应答,PRRSV抗体水平快速上升。可为猪场制定合理的PRRSV疫苗免疫程序提供指导。     

猪繁殖与呼吸综合征油乳剂灭活疫苗的免疫效果研究

猪繁殖与呼吸综合征(PRRS)是由猪繁殖与呼吸综合征病毒(PRRSV)引起的一种以母猪繁殖障碍,仔猪呼吸系统症状和高死亡率为特征的传染病.本研究用PRRSV SY株和美洲型代表株VR2332制备成油乳剂灭活疫苗,同时选用2种商品化PRRS油乳剂灭活疫苗(CH-1a株和SD1株),在曾发生过PRRS流行的某猪场进行4种疫苗的免疫试验.使用美国IDEXX公司的试剂盒检测血清中的PRRSV抗体效价,并用XCHeK软件系统处理数据.免疫试验结果显示,一免后第6组(CH1-a株)产生的抗体效价较其它组高;第3组和第4组(VR2332株)在二免后抗体效价较一免有小幅升高.对免疫试验的结果分析显示,接种灭活疫苗后抗体效价未达到预期的水平,其中具体的影响因素或工艺问题尚需要进一步探讨.此外,IDEXX公司的PRRSV试剂盒不能区分野毒抗体和疫苗毒抗体,这也可能是影响测定实际抗体效价的凶素之一.     

两种猪瘟病毒ELISA抗体检测试剂盒对疫苗免疫猪血清抗体检测的比较试验

为了比较两种猪瘟病毒抗体检测试剂盒对猪瘟疫苗免疫抗体的检测结果,本试验将27头猪瘟抗体阴性仔猪免疫猪瘟活疫苗后7、10、14、17、20、23、27、30、34 d共9个时间点采血,分别用两种猪瘟病毒ELISA抗体检测试剂盒进行抗体检测,同时采用OIE指定方法-荧光抗体病毒中和试验对检测结果进行验证。结果表明,虽然两种试剂盒均可在免疫后30 d 100%检测到免疫猪体内的猪瘟抗体,但国产试剂盒在疫苗免疫后第10天便可在6/21猪体内检测到猪瘟抗体,20 d时抗体检测全为阳性,而美国IDEXX公司的试剂盒在疫苗免疫后27 d才在11/21猪体内检测到猪瘟抗体,30 d时才全部变为阳性,而两种试剂盒对6头阴性对照猪血清连续跟踪检测34 d均为阴性。由此可以得出结论:国产试剂盒在疫苗免疫后的早期抗体检测中敏感性明显高于IDEXX公司的试剂盒。     

重组N蛋白抗原检测PRRSV抗体ELISA的研究Ⅳ.与IDEXX ELISA试剂盒及Western blot的比较

利用重组N蛋白抗原建立了检测猪繁殖与呼吸综合征病毒（PRRSV）抗体的ELISA方法并组装成试剂盒，将试制的3批试剂盒分别与IDEXX生产的试剂盒及Western—blot进行了符合率试验。试验结果表明，所研制的试剂盒与Western blot的符合率达97．67％以上。对460份临床血清分别用自制的试剂盒和IDEXX公司生产的试剂盒进行检测，其中有37份不相符合，用Western blot对这37份血清进行验证，有35份血清检测结果与自制的试刺盒检测结果一致。由此表明，自行研制的试剂盒，其特异性和敏感性均能满足目前临床上该疫病的流行病学分析或免疫抗体检测。     

重组N蛋白抗原检测PRRSV抗体ELISA的研究Ⅱ.试剂盒阴阳性临界值的测定及其与IDEXX公司试剂盒的比较

对临床上采集的899份猪血清样本。用以纯化的重组N蛋白为包被抗原建立的检测猪繁殖与呼吸综合征病毒（PRRSV）抗体的间接ELISA进行检测．运用统计学方法摸清了检测结果的分布规律。并扣国外IDEXX公司PRRSV抗体检测试剂盒同时对460份血清样本进行检测。结果表明。2种方法的符合率为91．73％。利用TG—ROC软件确定了自制的ELISA酶标板（NP—ELISA）的临界值。并标定试剂盒的特异性扣敏感性均为92．6％。ELISA的结果判定标准是：当以血清样本L为标准参考阳性血清时，样品与阳性血清的比值（S／P）小于或等于0．4为阴性；S／P在0．4与0．5之间为可疑；S／P大于或等于0．5为阳性。与IDEXX公司PRRSV抗体检测试剂盒对临床样品的检测结果进行比较后，初步判定所建立的ELISA之所以出现较多的假阴性。可能是目前临床上出现了PRRSV欧洲型所致。     

我国规模化猪场蓝耳病流行病学调查

2005年7月-12月，对10个养猪主产区53个规模化养猪场（母猪头数600头以上）进行PRRS流行病学调查。共采集2635份血样，使用IDEXX公司PRRS抗体检测试剂盒进行抗体检测。检测结果表明，所有送检猪场都至少有一个样本呈PRRSV抗体阳性，样本阳性率76．85％（2025份）。山东样本阳性率40％，福建和湖北的样本阳性率在90％以上。后备母猪共计采样239份，样本阳性率为88．70％；1～3胎母猪采样418份，样本阳性率82.54％；4～6胎母猪采样278份，样本阳性率78.06％。生产猪群从断奶到保育阳性率从56．62％降低到49.71％，以后逐渐上升，表明在保育期发生感染，保育猪是PRRSV多发猪群。     

PRRSV持续性感染猪群抗体动态观察及对猪瘟疫苗免疫的影响

为了解在PRRSV持续性感染猪群中的抗体动态,对蓝耳病阳性猪场育肥猪、经产母猪、后备母猪及仔猪每周采血1次,分离血清,用RT-PCR方法检测PRRSV,ELISA试剂盒检测抗PRRSV抗体并检测猪瘟疫苗免疫后的抗体水平.结果表明,在猪群康复后PRRS抗体水平呈下降趋势,并逐渐趋向于稳定,当整个猪群再次表现临床症状时,抗体逐渐上升至一定水平,但抗原检出率较低;猪瘟疫苗免疫后抗体水平上升依然很快,免疫效果较好.     

PRRSV-IPMA抗体检测试剂盒的研制及其应用

建立了一种检测猪生殖与呼吸综合征病毒（PRRSV）血清抗体的免疫过氧化物酶单层细胞试验法（IPMA），并组装成PRRSV-IPMA抗体检测试剂盒。对该试剂盒的敏感性、特异性、重复性及保存期等进行了试验，并与国外IDEXX ELISA试剂盒进行了比较。结果显示，用该试剂盒检测PRRSV人工接种猪血清样品，第1周抗体阳性检出率为50％，从第2周起抗体阳性检出率均为100％，而对照组猪血清抗体检测均为阴性。该试剂盒重复性好，-20℃保存18个月稳定，与其他病毒参考血清无交叉反应，与国外IDEXX ELISA试剂盒的符合率为83．3%。用该试剂盒对采自黑龙江、吉林、辽宁、河北、上海等地13个猪场的520份正常猪血清样品进行了抗体检测，结果，4个猪场阳性率高达90％以上，仅有2个猪场为阴性，其余猪场阳性率为10％～57%。     

猪繁殖与呼吸综合征病毒感染抑制猪瘟疫苗的免疫应答

对20日龄SPF猪和20日龄猪繁殖与呼吸综合征（PRRS）血清阳性猪，人工感染猪繁殖与呼吸综合征病毒（PRRSV）北京分离株（BJ－4）后48h接种猪瘟疫苗，利用ELISA方法检测仔猪针对PRRSV和猪瘟疫苗的体液免疫，利用MTS法检测仔猪外周血单核细胞对有丝分裂原ConA的刺激反应。结果表明，不论是SPF仔猪还是带有PRRSV抗体的仔猪，在鼻内接种PRRSV后48h接种猪瘟疫苗，其对猪瘟疫苗的抗体反应显著低于对照组，对有丝分裂原ConA的刺激反应也下降。由此说明，PRRSV感染使仔猪对猪瘟疫苗的免疫应答受到抑制。     

肉用鸽新城疫的诊治

采用IDEXX公司生产的猪瘟抗原（CSFV－Ag）ELISA试剂盒和动物接种试验，对不同盐渍时间的猪肠衣进行猪瘟检疫。结果：盐渍时间达6个月的肠衣仍可用CSFV－Ag ELISA试剂盒进行检测，但盐渍后猪瘟病毒免疫原性和感染性存在明显差异。     

白术、微米白术和白术多糖对断奶仔猪生长性能和肠道形态及微生态区系的影响

试验选用96头平均体重14.82 kg左右的杜×长×大断奶仔猪,随机分成4组,每组3栏,每栏8头(公母各半)。对照组饲喂基础日粮,试验1、2、3组分别添加1%80目白术、0.2%白术多糖和1%微米白术。试验期30 d。结果表明:在生长性能方面,与对照组相比,1%微米白术添加组可显著提高日增重(P0.05)、降低饲料增重比和腹泻率,而且效果优于1%80目白术组和0.2%白术多糖组,在肠道形态和肠道微生态区系方面,与对照组相比,日粮添加1%80目白术、0.2%白术多糖、1%微米白术均可不同程度的提高十二指肠和空肠的绒毛高度,加深十二指肠和空肠的隐窝深度,并且增加肠道微生态区系的多样性,其中以1%微米白术添加组的效果最佳。     

Prevalence and seasonal incidence of nematode parasites and fluke infections of sheep and goats in eastern Ethiopia

Sissay, M.M., Uggla, A. and Waller, P.J., XXXX. Prevalence and seasonal incidence of nematode parasites and fluke infections of sheep and goats in eastern Ethiopia. Tropical Animal Health and Production, XXXX. A 2-year abattoir survey was carried out to determine the prevalence, abundance and seasonal incidence of gastro-intestinal (GI) nematodes and trematodes (flukes) of sheep and goats in the semi-arid zone of eastern Ethiopia. During May 2003 to April 2005, viscera including liver, lungs and GI tracts were collected from 655 sheep and 632 goats slaughtered at 4 abattoirs located in the towns of Haramaya, Harar, Dire Dawa and Jijiga in eastern Ethiopia. All animals were raised in the farming areas located within the community boundaries for each town. Collected materials were transported within 24 h to the parasitology laboratory of Haramaya University for immediate processing. Thirteen species belonging to 9 genera of GI nematodes (Haemonchus contortus, Trichostrongylus axei, T. colubriformis, T. vitrinus, Nematodirus filicollis, N. spathiger, Oesophagostomum columbianum, O. venulosum, Strongyloides papillosus, Bunostomum trigonocephalum, Trichuris ovis, Cooperia curticei and Chabertia ovina), and 4 species belonging to 3 genera of trematodes (Fasciola hepatica, F. gigantica, Paramphistomum {Calicohoron} microbothrium and Dicrocoelium dendriticum) were recorded in both sheep and goats. All animals in this investigation were infected with multiple species to varying degrees. The mean burdens of adult nematodes were generally moderate in both sheep and goats and showed patterns of seasonal abundance that corresponded with the bi-modal annual rainfall pattern, with highest burdens around the middle of the rainy season. In both sheep and goats there were significant differences in the mean worm burdens and abundance of the different nematode species between the four geographic locations, with worm burdens in the Haramaya and Harar areas greater than those observed in the Dire Dawa and Jijiga locations. Similar seasonal variations were also observed in the prevalence of flukes. But there were no significant differences in the prevalence of each fluke species between the four locations. Overall, the results showed that Haemonchus, Trichostrongylus, Nematodirus, Oesophagostomum, Fasciola and Paramphistomum species were the most abundant helminth parasites of sheep and goats in eastern Ethiopia.     

Phase I evaluation of CCNU (lomustine) in tumor-bearing cats

1-(2-Chloroethyl)3-cyclohexyl-1-nitrosourea (CCNU) is an alkylating agent in the nitrosourea subclass. A prospective evaluation of CCNU was done to determine the maximally tolerated dosage of CCNU in tumor-bearing cats. Response data were obtained when available. Twenty-five cats were treated with CCNU at a dosage of 50-60 mg/m3 body surface area. Complete hematologic data were available for 13 cats. Neutropenia was the acute dose-limiting toxicity. The median neutrophil count at the nadir was 1,000 cells/microL (mean, 2,433 cells/microL; range, 0-9,694 cells/microL). The time of neutrophil nadir was variable, occurring 7-28 days after treatment, and counts sometimes did not return to normal for up to 14 days after the nadir. Based on these findings, a 6-week dosing interval and weekly hematologic monitoring after the 1st treatment with CCNU are recommended. The nadir of the platelet count may occur 14-21 days after treatment. The median platelet count at the nadir was 43,500 cells/microL. No gastrointestinal, renal, or hepatic toxicities were observed after a single CCNU treatment, and additional studies to evaluate the potential for cumulative toxicity should be performed. Five cats with lymphoma and 1 cat with mast cell tumor had measurable responses to CCNU. Phase II studies to evaluate antitumor activity should be completed with a dosing regimen of 50-60 mg/m3 every 6 weeks.     

Y‐chromosomal variation of local goat breeds of Turkey close to the domestication centre

Genetic variations in chromosome Y are enabling researchers to identify paternal lineages, which are informative for introgressions and migrations. In this study, the male‐specific region markers, sex‐determining region‐Y (SRY), amelogenin (AMELY) and zinc finger (ZFY) were analysed in seven Turkish native goat breeds, Angora, Kilis, Hair, Honaml?, Norduz, Gürcü and Abaza. A SNP in the ZFY gene defined a new haplotype Y2C. All domestic haplogroups originate from Capra aegagrus, while the finding of Y1A, Y1B, Y2A and Y2C in 32, 4, 126 and 2 Turkish domestic goats, respectively, appears to indicate a predomestic origin of the major haplotypes. The occurrence of four haplotypes in the Hair goat and, in contrast, a frequency of 96% of Y1A in the Kilis breed illustrate that Y‐chromosomal variants have a more breed‐dependent distribution than mitochondrial or autosomal DNA. This probably reflects male founder effects, but a role in adaptation cannot be excluded.     

Furosemide continuous rate infusion in the horse: evaluation of enhanced efficacy and reduced side effects

Continuous rate infusion (CRI) of furosemide in humans is considered superior to intermittent administration (IA). This study examined whether furosemide CRI, compared with IA, would increase diuretic efficacy with decreased fluid and electrolyte fluctuations and activation of the renin-angiotensin-aldosterone system (RAAS) in the horse. Five mares were used in a crossover-design study. During a 24-hour period, each horse received a total of 3 mg/kg furosemide by either CRI (0.12 mg/kg/h preceded by a loading dose of 0.12 mg/kg IV) or IA (1 mg/kg IV q8h). There was not a statistically significant difference in urine volume over 24 hours between methods; however, urine volume was significantly greater after CRI compared with IA during the first 8 hours ([median 25th percentile, 75th percentile]: 9.6 L [8.9, 14.4] for CRI versus 5.9 L [5.3, 6.0] for IA). CRI produced a more uniform urine flow, decreased fluctuations in plasma volume, and suppressed renal concentrating ability throughout the infusion period. Potassium, Ca, and Cl excretion was greater during CRI than IA (1,133 mmol [1.110, 1,229] versus 764 mmol [709, 904], 102.7 mmol [96.0, 117.2] versus 73.3 mmol [65.0, 73.5], and 1,776 mmol [1,657, 2.378] versus 1,596 mmol [1,457, 1,767], respectively). Elimination half-lives of furosemide were 1.35 and 0.47 hours for CRI and IA, respectively. The area under the excretion rate curve was 1,285.7 and 184.2 mL x mg/mL for CRI and IA, respectively. Furosemide CRI (0.12 mg/kg/h) for 8 hours, preceded by a loading dose (0.12 mg/kg), is recommended when profound diuresis is needed acutely in horses.     

The Epidemiology of Gastrointestinal Nematodes of Dairy Cattle in Central Kenya

The epidemiology of H. placei and of other gastrointestinal nematodes in yearling dairy cattle was examined on two farms in Kiambu District, central Kenya during each of 13 one-month periods from April 1993 to April 1994. On each farm, 32 newly weaned dairy calves were given a single dose of albendazole and then placed on experimental pastures. Twelve of the animals were designated for bi-monthly slaughter (n = 2) and analysis of worm population characteristics and 20 were designated for blood and faecal collection and for weighing. Two parasite-free tracer calves were grazed alongside the weaner calves each month throughout the study period and were also slaughtered for analysis of worm populations. Faecal egg counts, haematological and serum pepsinogen determinations, herbage larval counts, and animal live weight changes were recorded monthly. The study revealed that Haemonchus placei, Trichostrongylus axei, Cooperia spp. and Oesophagostomum radiatum were responsible for parasitic gastroenteritis and that H. placei was the predominant nematode present in the young cattle on both farms. Faecal egg counts from resident cattle and necropsy worm counts revealed that pasture larval levels were directly related to the amount of rainfall. The total worm burdens in the animals were highest during the rainy season (March–June and October–December) and lowest during the dry seasons (July–September and January–February). The very low recovery of immature larvae of H. placei from the tracer calves indicated that arrested development is not a feature of the life cycle of this parasite in central Kenya. The maintenance of the parasite population depended on continuous cycling of infection between the host and the pasture. The agroclimatic conditions of the study area were such that, in general, favourable weather conditions for the development and survival of the free-living stages of gastrointestinal nematodes existed all year round.     

Diversity of Ectoparasites in Sheep Flocks in Sa~o Paulo,Brazil

The occurrence of ectoparasites in sheep flocks is frequently reported but seldom quantified. Sheep production used to be a predominantly family activity in the state of Sa~o Paulo (Brazil), but it began to become a commercial activity in the past decade. Thus, information about the ectoparasites existing in sheep flocks has become necessary. The present data were obtained by means of questionnaires sent to all sheep breeders belonging to the `Associaça~o Paulista de Criadores de Ovinos' (ASPACO; Sa~o Paulo State Association of Sheep Breeders). Response reliability was tested by means of random visits paid to 10.6% of the respondents. Most of the properties (89.5%) reported the presence of one or more ectoparasites. Screw-worm (Cochliomyia hominivorax) was the most frequent ectoparasite (72.5%), followed by bot fly larvae (Dermatobia hominis, 45.0%), ticks (Amblyomma cajennense) and Boophilus microplus, 31.3%) and finally lice (Damalinia ovis, 13.8%). Combined infestations also occurred, the most common one being screw-worm with bot fly larvae (36.0%) followed by bot fly larvae with ticks (13.9%), screw-worm with ticks (9.3%), bot fly larvae with lice (6.9%), and ticks with lice (5.0%). The most common triple combination was screw-worm, bot fly larvae and ticks (12.8%). Breeds raised for meat or wool were attacked by bot fly larvae and ticks more often than other breeds. Lice were only absent from animals of indigenous breeds. The relationships among these ectoparasites are discussed in terms of sheep breeds, flock size, seasonality and the ectoparasitic combinations on the host.     

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.     

A brief history of the prevention of infectious diseases by immunisations

Infectious diseases have always been a terrible scourge for humans. The appearance of these plagues, as they were called without distinction, was generally connected to various conditions: asters, climatic changes or religious reasons. The concept of contagious, and then infectious, diseases came slowly. Variolation, i.e. transmission of ‘virulent’ matter to induce a natural disease and the immunity against it, was brought from Constantinople to England by Lady Montague, in 1721. This ‘variolation’ technique was also often performed in veterinary medicine against diseases like sheep-pox or pleuropneumonia. As ‘vaccination’ is the term generally accepted for ‘immunisation’, variolation can be the word designating such a technique. The second period of the history of immunisation began, in 1880, with the studies of Pasteur and his collaborators. A great number of bacterial vaccines were developed: dead, live but attenuated or only parts of pathogens. The viruses were produced in animals, then in eggs and at last, in tissue cultures. Second generation vaccines appeared with genetic engineering: recombinant vaccines, vector vaccines, nucleic acids vaccines, and markers vaccines, among others. These novel technologies can permit the development of new ones and improve the quality of the vaccines already existing.