H3亚型猪流感病毒SYBR Green Ⅰ实时荧光定量PCR检测方法的建立

为建立一种快捷、可行的检测H3亚型猪流感病毒(SIV)的方法,本研究根据GenBank中登录的H3亚型SIV HA基因的保守序列,设计合成一对特异性引物,建立了一种检测H3亚型SIV的SYBR Green Ⅰ荧光定量检测方法,并进行灵敏度、稳定性和特异性试验,与普通PCR进行比较.研究结果表明,标准曲线的循环阈值与模板浓度呈现良好的线性关系,R2为0.994,CV在0.17％～1.41％之间,具有良好稳定性.除H3亚型SIV外,对H1、H4、H6、H9亚型SIV以及猪瘟病毒、猪繁殖与呼吸综合征病毒、口蹄疫病毒和猪圆环病毒2型的检测均为阴性,与普通PCR相比更灵敏.该方法特异性好,准确率高,适于临床分离鉴别H3亚型SIV.     

H1亚型猪流感病毒一步法实时荧光定量RT-PCR检测方法的建立及应用

为建立一种快速、简便、准确的方法以诊断和检测H1亚型猪流感病毒(swine influenza virus,SIV),试验根据H1亚型SIV血凝素(hemagglutinin,HA)基因保守序列,分别设计并合成1对特异性引物和1条TaqMan MGB探针,建立检测H1亚型SIV的一步法实时荧光定量RT-PCR技术。结果显示,该方法的敏感性可达10²拷贝/μL,除H1亚型SIV外,对H3N2亚型SIV、H9N1亚型SIV、猪瘟病毒、猪繁殖与呼吸综合征病毒、猪流行性腹泻病毒、猪传染性胃肠炎病毒的检测均为阴性,且应用该方法对疑似猪流感样品进行检测,其结果与SPF鸡胚分离病毒方法结果的符合率为94%。本试验结果表明该方法特异性强、重复性好,有望成为一种特异、敏感、快速、定量检测H1亚型SIV的方法。     

广东省部分地区规模化猪场猪流感病毒感染的血清学调查与分析

为了解广东省规模化猪场猪流感病毒(SIV)感染情况,本研究采用ELISA方法和血凝抑制试验(HI),对2011年～2012年采集的1 050份血清样品进行SIV血清学检测.两种检测方法结果显示1 050份血清样品中SIV抗体阳性率分别为50.4％(ELISA)和50.2％(HI).其中珠三角地区和粤东地区的感染率高于粤西地区.SIV亚型调查结果显示该地区流行的SIV主要为H1和H3亚型,抗体阳性率分别为39.2％和18.2％(ELISA).部分猪场存在H9亚型SIV抗体.部分猪群中同时存在H1和H3两种亚型SIV抗体,表明猪群中存在不同亚型SIV混合感染.本研究为广东省猪流感的预防提供参考依据.     

猪流感病毒LAMP检测方法的建立

本试验针对猪流感病毒（swine influenza virus,SIV）NP基因保守区域设计并合成6条引物,建立了SIV的环介导等温扩增（LAMP）检测方法,并进行了特异性、敏感性和重复性试验。结果显示,该方法可特异性检测H1N1、H1N2、H3N2、类禽H1N1亚型SIV及甲型H1N1流感病毒,但不能检测猪繁殖与呼吸综合征病毒、猪细小病毒、猪瘟病毒、猪伪狂犬病病毒、猪圆环病毒2型、日本乙型脑炎病毒;该方法的最低检测量为100拷贝/μL质粒DNA。结果表明建立的LAMP方法具有较高的敏感性和特异性,可用于SIV的快速检测。     

河南省部分地区猪流感血清学调查

采用血凝抑制试验对河南省新乡、焦作、漯河等地采集的139份猪血清样品进行了猪流感病毒H1、H3、H5、H9亚型抗体的检测。结果显示,在被调查的139份血清中,H1亚型SIV抗体阳性率为43．17％,H3亚型SIV抗体阳性率为0,H5亚型SIV抗体阳性率为2．16％,H9亚型SIV抗体阳性率为1．44％;H1＋H5亚型SIV抗体阳性率为1．44％：H1＋H9亚型SIV抗体阳性率为1．44％;H1＋H5＋H9亚型SIV抗体阳性率为0。表明在所调查的猪群中,猪流感病毒的感染较为普遍,大部分猪场都曾被H1亚型感染,部分猪群有多种亚型混合感染存在。     

H1和H3亚型猪流感病毒二重TaqMan-MGB探针荧光RT-PCR检测方法的建立

根据H1和H3亚型猪流感病毒(SIV)血凝素(HA)编码基因的保守序列,分别设计合成特异性引物和Taq Man-MGB探针,建立了一种检测H1和H3亚型SIV的二重荧光RT-PCR方法。结果显示,该方法仅对H1和H3亚型SIV呈特异性扩增,对H9亚型SIV、猪繁殖与呼吸综合征病毒(PRRSV)、猪瘟病毒(SFV)、猪流行性腹泻病毒(PEDV)和猪传染性胃肠炎病毒(TGEV)无交叉扩增反应;用该方法检测H1和H3亚型SIV的HA基因的RNA标准对照(SIV-H1-RNA,SIV-H3-RNA),最适线性检测范围分别为3.7×10~1~3.7×10~8拷贝数/反应和3.4×10~0~3.4×10~8拷贝数/反应,最低检出限分别为38和34个拷贝数;该方法的组内试验和组间试验的变异系数均小于2.0%,显示其具有良好的可重复性。用该方法对520份进口猪的鼻拭子样本和78份国内猪鼻拭子样本进行SIV检测发现,进口猪鼻拭子样本的SIV检测结果均为阴性,12份国内猪鼻拭子样本的H1亚型SIV检测结果为阳性,5份国内猪鼻拭子样本的H3亚型SIV检测结果为阳性。本方法的建立为H1和H3亚型SIV检测提供了一种快速、敏感和特异的技术手段。     

河南省部分地区猪流感血清学调查

采用血凝抑制试验对河南省新乡、焦作、漯河等地采集的139份猪血清样品进行了猪流感病毒H1、H3、H5、H9亚型抗体的检测.结果显示,在被调查的139份血清中,H1亚型SIV抗体阳性率为43.17%,H3亚型SIV抗体阳性率为0,H5亚型SIV抗体阳性率为2.16%.H9亚型SIV抗体阳性率为1.44%:H1+H5亚型SIV抗体阳性率为1.44%;H1+H9亚型SIV抗体阳性率为1.44%:H1+H5+H9亚型SIV抗体阳性率为0.表明在所调查的猪群中,猪流感病毒的感染较为普遍,大部分猪场都曾被H1亚型感染,部分猪群有多种亚型混合感染存在.     

基于多重RT-PCR同时鉴定猪流感病毒不同HA和NA基因亚型的DHPLC检测方法的建立

为建立快速、敏感并同时鉴定不同HA和NA基因亚型的猪流感病毒(SIV)的方法。本研究根据SIV的H1、H2、H3、H5、H9、N1及N2亚型基因的保守序列分别设计型特异性引物,建立了同时扩增SIV不同亚型的多重RT-PCR及变性高效液相色谱(DHPLC)的高灵敏度和高通量分型检测方法。结果显示,该方法能够特异性的检测并鉴定H1、H2、H3、H5、H9、N1、N2等亚型SIV,而对猪瘟病毒、口蹄疫病毒、猪流行性腹泻病毒、猪繁殖和呼吸综合征病毒均无交叉反应,该方法的最低检出限为100拷贝/μL核酸。对76份猪流感鼻拭子样品临床样品检测结果表明,DHPLC与商业化荧光定量PCR检测试剂盒的检测结果完全一致。本研究建立的方法,特异性强、敏感性高、自动化程度高,为快速分型检测SIV提供技术支撑,并具有良好的应用前景。     

H1亚型猪流感病毒微滴数字RT-PCR定量检测方法的建立

本研究针对H1亚型猪流感病毒(swine influenza virus,SIV)HA基因保守序列设计引物和探针,通过反应条件优化,建立了一种快速、准确检测H1亚型SIV的微滴数字RT-PCR定量方法。该方法特异性强,除H1亚型SIV外,H3、H5、H7亚型SIV以及猪瘟病毒、猪繁殖与呼吸综合征病毒等检测均为阴性;敏感性高,最低可检测4.7拷贝/μL;重复性好,对5个不同稀释度的H1亚型SIV RNA进行3次重复试验,每个稀释度的变异系数均小于5%。利用该方法对湖南省规模化养殖场收集的30份猪鼻拭子样品进行检测,发现与荧光RT-PCR检测结果一致。试验表明,该方法快速、准确、灵敏,可为H1亚型SIV的快速筛查及流行病学研究提供可靠的技术保障。     

分子信标荧光定量PCR检测H3N2亚型猪流感病毒方法的建立

利用新型荧光探针—分子信标,建立一种检测猪流感病毒的新方法。根据H3N2亚型猪流感病毒（SIV）的HA和NA基因的保守基因序列,分别设计并合成了特异性引物和分子信标探针,利用实时荧光定量PCR技术检测H3N2亚型SIV。构建重组质粒pSK-H3和pSK-N2并绘制标准曲线。结果显示,该检测方法的敏感性达到102拷贝/μL;与其它主要相关病毒均不发生交叉反应,批内和批间试验的重复性变异系数（CV）均小于3％,表明该方法灵敏度强、特异性好。此方法的建立将为流感病毒H3N2亚型定型检测提供一种快速有效的方法。     

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.     

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.     

Prevalence of gastric lesions in racing Alaskan sled dogs

Human and equine athletes are reported to have a high prevalence of gastric disease, and anecdotal evidence suggests a similar phenomenon applies to racing sled dogs. To investigate the prevalence of gastric disease in racing sled dogs, we conducted 2 gastroscopy studies on dogs competing in the annual Iditarod Sled Dog Race. A pilot study of dogs that were either dropped from the 2000 Iditarod Sled Dog Race because of illness or that finished the race indicated that, approximately 5 days after competing, 10 of 28 dogs (35%) had endoscopic evidence of gastric ulceration, erosion, or hemorrhage. The next year, an endoscopic study of 73 dogs participating in the 2001 Iditarod race was performed in order to evaluate a larger population of dogs. Data from 70 of these dogs could be used; 34 (48.5%) had ulceration, erosion, gastric hemorrhage, or some combination of these findings. When this group of 70 dogs was compared retrospectively to a control group of 87 dogs presented to the Texas A&M University (TAMU) Veterinary Medical Teaching Hospital, the Iditarod sled dogs had a significantly higher prevalence (P = .049) of gastric lesions. These findings suggest that, similar to athletes of other species, elite canine athletes have an increased prevalence of gastric disease compared to the canine population at large.     

Internal Parasites and Haematological Values in Cattle Slaughtered in Buea Subdivision of Cameroon

Tropical Animal Health and Production -     

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.     

Chemotaxis of macrophage in inflammation

Our particular attention in this article was given to natural mediators for macrophages isolated from the sites of tissue injury. A number of chemotactic factors, which may satisfy many criteria making them acceptable as inflammatory leucocyte chemotactic factors, has been separated. Among them, our laboratory has isolated three macrophage (monocyte) chemotactic factors (MCF-a, -b and -c). Their purification, characterization and functional specificity are discussed.     

Evaluation of biohydrogenation rate of canola vs. soya bean seeds as unsaturated fatty acids sources for ruminants in situ

An experiment was conducted to study disappearance of C14 to C18 fatty acids, lag times and biohydrogenation (BH) rates of C18 fatty acids of ground soya bean and canola seeds in situ. Three ruminally fistulated Dallagh sheep were used to determine ruminal BH of unsaturated fatty acids (UFAs). Differences in the disappearance of fatty acids through the bags and lag times were observed between the oilseeds. We saw that the longer the incubation time of the oilseeds in the rumen, the lower the content of C18:2 and C18:3. Significantly higher lag times for both C18:2 and C18:3 were observed in ground canola compared to ground soya bean. BH rates of C18:2 and C18:3 fatty acids in soya bean were three times higher than those of canola. These results suggest that the fatty acid profile of fat source can affect the BH of UFAs by rumen micro‐organisms. So that UFAs of canola had higher ability to escape from ruminal BH. It seems that fatty acid profile of ruminant products is more affected by canola seed compared to soya bean seed.     

Serum biochemical values and mineral element contents of tissues in yaks

Serum biochemical values and the wet weight to dry weight ratios of tissues were determined in yaks in Shandan county of Gansu province. The liver, kidney, heart and muscle contents of seven elements in yaks were also analysed. Most serum biochemical values were similar to those of cattle, camels and sheep, but the calcium concentration was considerably above the normal range for other ruminants. The liver contained the highest concentrations of copper, manganese and cobalt and the kidney of selenium, iron and calcium.Abbreviations Alb albumin - ALT alanine aminotransferase - AST aspartate aminotransferase - BUN blood urea nitrogen - Chol cholesterol - Glob globulin - -GT -glutamyl transpeptidase - IP inorganic phosphorus - TP total protein