TCA对小鼠脾脏T B淋巴细胞和T淋巴细胞亚群变化的影响

牛磺胆酸(taurocholate acid,TCA)是胆酸(CA)的羧基与牛磺酸(taurine)的氨基以酰胺键结合的一种初级胆汁酸[1],其化学名称为3α,7α,12α-三羟基-5β-24-胆烷酰-N-牛磺酸.经研究发现牛磺胆酸在抗炎、镇咳、祛痰等方面具有显著的药理作用[2-4].但目前,国内外关于TCA的免疫作用研究开展甚少,为此本文检测了TCA对小鼠脾脏CD4 、CD8 T淋巴细胞和CD19 B淋巴细胞百分率的影响,以便为揭示TCA对细胞免疫功能的调节作用提供线索.     

BVDV-E2截短基因重组卡介苗对牛的免疫效果评价

为评价牛病毒性腹泻病毒(BVDV)E2截短基因重组卡介苗对牛的免疫效果,将BVDV抗原抗体阴性牛随机分为rBCG-pMV361-E2-1(1 aa-297aa)、rBCG-pMV361-E2-2(1 aa-345 aa)、rBCG-pMV361-E2-3(1 aa-374 aa)、rBCG-pMV361-E2-4(45 aa-297 aa)、rBCG-pMV361-E2-5(45 aa-345 aa)、rBCG-pMV361-E2-6(45 aa-374 aa)、BVDV对照组、BCG对照组和PBS对照组,各组牛免疫相应疫苗后通过特异性抗体检测、淋巴细胞增殖试验、淋巴细胞亚群检测和细胞因子检测分析疫苗的免疫效果。结果显示,BVDV E2截短基因重组卡介苗均可诱导BVDV特异性抗体的产生,rBCG-pMV361-E2-1组抗体水平高于其他重组卡介苗试验组和BVDV对照组。淋巴细胞增殖试验结果显示,rBCG-pMV361-E2-2组SI为2.038±0.21,显著高于其他重组卡介苗试验组(P<0.01)。牛外周血CD4^+、CD8^+T淋巴细胞亚群检测结果显示,rBCG-pMV361-E2-5组牛外周血中CD4^+和CD8^+ T淋巴细胞亚群含量与PBS组比较,差异极显著(P<0.01)。IFN-γ检测结果显示,rBCG-pMV361-E2-1的IFN-γ水平显著高于其他试验组和对照组(P<0.01)。研究表明,rBCG-pMV361-E2-1可诱导接种牛产生较好的体液免疫应答,rBCG-pMV361-E2-1、rBCG-pMV361-E2-2和rBCG-pMV361-E2-5在诱导细胞免疫应答上效果较好。     

临床健康牛外周血淋巴细胞亚类分布的研究

以流式细胞术研究了临床健康牛外周血中CD3、CD4、CD8和γδT淋巴细胞的分布情况.结果表明,牛外周血淋巴细胞中各T淋巴细胞亚类分布差异较大.其中CD3平均值为53.88±8.71%,CD4为17.13±3.22%,CD8为15.10±5.81%,γδT为18.77±8.07%.同时检测了广泛存在于各种淋巴细胞表面的白细胞介素-2α受体(IL-2Rα),发现IL-2Rα百分率与γδT细胞百分率具有正相关关系,即γδT细胞百分率高时,IL-2Rα也高,反之亦然.跟踪3头牛外周血各淋巴细胞亚类分布百分率的实验结果,证明牛外周血中各淋巴细胞亚类分布的差异,与牛的生物节律有着密切关系.     

α-酮戊二酸二甲酯预处理对犬脂肪间充质干细胞氧化应激损伤的保护作用

研究旨在探究α-酮戊二酸二甲酯(dimethyl α-ketoglutarate,DMKG)预处理对犬脂肪间充质干细胞(adipose-derived mesenchymal stem cells,ADSCs)抗氧化应激损伤的影响。以含0、0.2、0.4、0.6、0.8、1.0 mmol/L过氧化氢(H₂O₂)的DMEM/F12基础培养基处理犬ADSCs,1 h后采用CCK-8法检测细胞存活率,筛选最适浓度以建立犬ADSCs氧化应激模型。选取生长良好的P3代犬ADSCs分为3组,分别为空白对照组、模型组、DMKG组。空白对照组正常培养,不作处理;模型组使用最佳浓度的H₂O₂溶液处理犬ADSCs 1 h;DMKG组使用1 mmol/L DMKG预处理犬ADSCs 24 h后,使用最佳浓度的H₂O₂溶液处理犬ADSCs 1 h。培养结束后,采用CCK-8法检测各组的细胞存活率,可见分光光度法检测还原型谷胱甘肽含量,荧光探针DCFH-DA检测活性氧水平,Annexin V/PI双染法检测细胞凋亡率,实时荧光定量PCR检测超氧化物歧化酶(superoxide dismutase,SOD)、过氧化氢酶(catalase,CAT)、抗凋亡相关基因Bcl-2和促凋亡相关基因Bax、Cleaved-Caspase3的mRNA表达水平。结果显示,与模型组相比,DMKG预处理能有效减少细胞内活性氧的产生(P<0.05),增加细胞存活率(P<0.01),并抑制细胞凋亡(P<0.05);同时,DMKG预处理可增加还原型谷胱甘肽含量(P<0.01),上调相关抗氧化酶基因SOD1、SOD2(P<0.01)和CAT(P<0.05),下调凋亡基因Cleaved-Caspase3的表达水平(P<0.05),增加Bcl-2/Bax的比值(P<0.05)。综上所述,DMKG预处理可显著提高犬ADSCs抗氧化、抗凋亡的能力,从而增加犬ADSCs在氧化应激条件下的存活。     

免疫调节剂对奶牛呼吸道及消化道疫病发病率的影响

为应对新疆地区部分规模化奶牛场牛传染性鼻气管炎病毒(IBRV)、牛病毒性腹泻-黏膜病病毒(BVDV)、牛呼吸道合胞体病毒(BRSV)、副流感病毒(PI3)和牛支原体等感染率高、发病率高的情况,本试验对18头围产期奶牛注射免疫调节剂,并检测注射前后奶牛血清中IFN-γ、IL-1、IL-2、IL-6、CD4、CD8六个指标的变化,并统计分析母牛产后和新生犊牛发病率和死亡率,对使用不同剂量免疫调节剂的作用进行综合评估。研究结果表明,对于感染多种病毒的围产期母牛而言,适量注射免疫调节剂具有上调IFN-γ、IL-1、IL-2、IL-6(白介素)的作用,提高机体免疫力和抗病能力。通过促使激活后的外周血中的T淋巴细胞成熟,增加T细胞在各种抗原激活后各种淋巴因子(γ-干扰素、白介素1、白介素2和白介素6)的分泌,使CD4/CD8趋于正常,产后母牛和新生犊牛发病率和死亡率均有一定程度降低,因此使用免疫调节剂具有调节和增强动物免疫功能和降低发病率的作用。     

探讨富含α-亚麻酸的添加剂对奶牛脂肪代谢及免疫功能的影响

在奶牛泌乳中期日粮中添加4.5%(精料的9.0%)富含α-亚麻酸的添加剂,探讨其对泌乳牛血清有关生化指标及其脂肪代谢与免疫功能的影响,结果表明(1)使血清HDLc(P＜0.01)浓度明显增加,而血清LDLc(P＜0.05)和vLDLc(P＞0.05)浓度降低,同时使血清TG、NEFA和CHO含量降低(P＞0.05);(2)增加血清Pr(P＜0.05)、INS(P＜0.05)、CH(P＞0.05)和T3(P＞0.05)浓度,而降低T4(P＜0.05)浓度显示具有很强的营养再分配功能,即泌乳牛物质合成代谢转向有利于泌乳的组织肝脏和乳腺;(3)提高红细胞膜PUFA组成(P＜0.01),而降低其TSFA组成(P＜0.01);(4)提高血液CD2+T细胞(P＜0.01)、CD4+T细胞(P＜0.05)和CD8+T细胞(P＜0.05),而降低血波CD4+/CD8+比值(P＞0.05),显示具有很强的免疫阳性.     

外泌体调控猪脂肪间充质干细胞向脂肪源神经干细胞诱导分化的研究

为探讨猪脂肪间充质干细胞(adipose-derived stem cells, ADSCs)来源外泌体对脂肪源神经干细胞(neural stem cells, NSCs)诱导的调控作用，采用含20 ng/mL表皮生长因子(epidermal growth factor, EGF)、20 ng/mL碱性成纤维细胞生长因子(basic fibroblast growth factor, bFGF)和2%B27的无血清DMEM/F12培养基，将ADSCs诱导成细胞球，通过免疫荧光技术检测神经干细胞标记蛋白巢蛋白(Nestin)和神经干细胞RNA结合蛋白(Musashi1)的表达，提取ADSCs外泌体，通过纳米粒径跟踪分析(NTA)和透射电镜技术对外泌体进行检测，PKH67染色后荧光显微镜观察ADSCs对外泌体的摄取情况，外泌体与ADSCs共培养作为试验组，不加外泌体作为对照组，qPCR检测外泌体对Nestin和Musashi1基因表达的影响。结果显示：ADSCs经诱导培养获得细胞球，免疫荧光检测显示所获得的细胞球Nestin和Musashi1抗体阳性，表明为诱导形成了神经干细胞；提取的AD...     

T、B淋巴细胞功能对流行性牛白血病发生发展的影响

本文回顾了T、B淋巴细胞功能与牛白血病发生发展的相关性。阐明了感染BLV牛B细胞淋巴瘤细胞除了来源于Bla(CD5^ CD11b^ )细胞，也可来源于B1b(CD5^-CD11b^ )及常规B2（CD5^-CD11b^-)细胞。探讨了T细胞功能对牛白血病的发生发展的影响，指出IL－12表达下降和IL－10表达增加可能导致了B细胞淋巴肉瘤的形成，Ⅰ型和Ⅱ型细胞因子的不平衡引起了BLV的发展。同时讨论了B－T细胞的相互作用在BLV感染时疾病阶段性发展过程中的作用。     

细胞传代对小型猪脂肪间充质干细胞及分泌因子的影响

为了探索细胞传代对小型猪脂肪间充质干细胞(adipose-derived mesenchymal stem cells, ADSCs)的影响，试验采用形态学观察法、CCK8法、Transwell迁移法、ELISA法对P3～P9代ADSCs的形态变化、增殖能力、迁移能力进行研究，并检测了传达次数对脂肪间充质干细胞的条件培养基(adipose-derived mesenchymal stem cells conditioned medium, ADSCs-CM)中血管内皮生长因子(VEGF)、血管生成素-1(ANG-1)、血管生成素-2(ANG-2)、碱性成纤维细胞生长因子(b-FGF)、白细胞介素-6(IL-6)、白细胞介素-1β(IL-1β)含量的影响。结果表明：随着传代次数的增加，ADSCs形态发生变化，细胞折射率变低，边界逐渐不清晰；不同传代次数的ADSCs生长曲线相似，近似S型，但P3、P5代细胞增殖能力显著高于P9代(P<0.05);且P5代细胞迁移能力与P3、P9代细胞存在极显著差异(P<0.01);P5代细胞分泌VEGF、ANG-1、ANG-2、b-FGF、IL...     

新疆褐牛CD46基因的原核表达及其多克隆抗体的制备

旨在克隆并表达新疆褐牛CD46基因,制备其多克隆抗体,为进一步研究牛CD46分子生物学功能奠定基础。采用RT-PCR方法从新疆褐牛脾脏中扩增CD46基因全长,进行测序,并对测序结果进行生物信息学分析,将CD46部分序列亚克隆于pET-28a(+)和pVAX1载体中。将阳性重组质粒pET-28a-△CD46转化于E.coli Rosetta-gamiB(DE3)感受态细胞,诱导表达截短CD46蛋白。用切胶纯化的His-△CD46融合蛋白免疫新西兰大白兔,制备多克隆抗体;采用ELISA测定多克隆抗体的效价;取无内毒素重组质粒pVAX1-△CD46转入BHK-21(仓鼠肾细胞)细胞,表达产物以制备的多克隆抗体为一抗,采用Western blot法检测该多克隆抗体的特异性。CD46基因的测序结果表明,部分基因蛋白表达、纯化条带大小与预期一致;制备的抗牛CD46多克隆抗体效价高于1∶128 000,并具有良好的特异性。     

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