正常生理及ISCOM疫苗免疫下小鼠乳腺Fc受体基因表达变化

本研究对小鼠不同生理阶段以及免疫条件下,乳腺内FcRn基因mRNA表达量的变化进行了分析。选择100只健康昆明小白鼠分为4组,在其分娩后4d分别进行如下制剂处理：灭菌生理盐水、脂肪酶蛋白（Lipase）＋灭菌生理盐水、空免疫刺激复合物（ISCOM）、Lipase-ISCOM。分娩后8d和12d用间接ELISA法测定乳中和血清中的特异性IgG效价,用RealTimePCR检测小鼠乳腺中FcRn基因的相对表达量,而正常生理状态乳腺内FcRn基因mRNA表达量的变化分别是在分娩后1d、4d、8d和12d进行检测。结果表明：正常状态下,乳腺B2M和FCGRT基因mRNA分别在0和1d表达最高,随后表达量下降并保持在一个稳定水平。免疫条件下,乳腺B2M和FCGRT基因mRNA显著上升。由此可知,免疫刺激可以引起小鼠乳FcRn基因表达上调。     

从中药方剂中提取的复合多糖对雏鸡免疫功能的影响

 480只7日龄健康罗曼雏鸡随机分为4组，每组120只。分别于8日龄注射中药复合多糖加环磷酰胺、中药复合多糖、环磷酰胺、生理盐水。分别在试验前、试验后第8、13、21、29、37天采血（每组15只）并涂片，测定淋巴细胞百分率及ANAE+ 淋巴细胞百分率；分别在用药前和停药后采血（每组12只）测定中性粒细胞吞噬力；分别在鸡18、25、32日龄（每组12只）测定腹腔巨噬细胞的吞噬功能；分别在NDⅡ系疫苗首免后7、14、21 d，二免后7、14、28 d采血（每组15只）分离血清，测定ND-HI抗体效价；分别在鸡4、6、9周龄（每组12只）时，测定法氏囊、胸腺、脾的重量；分别在用药前和停药后第4、8天采血（每组15只）测定红细胞免疫功能。试验结果表明：中药复合多糖可使淋巴细胞百分率和ANAE+ 淋巴细胞百分率、外周血中性粒细胞吞噬率和吞噬指数、腹腔巨噬细胞吞噬率和吞噬指数、首免和二免后ND-HI抗体效价、法氏囊和胸腺及脾重量、红细胞-C3b 花环率和红细胞-IC花环率明显升高。环磷酰胺可使上述指标明显下降，中药复合多糖加环磷酰胺组与环磷酰胺组之间上述指标差异显著，中药复合多糖加环磷酰胺组，上述指标接近或略高于生理盐水对照组。     

三明地区牛群疫病的流行病学调查

用ELISA方法对三明市2016年随机抽取的牛群血清样品进行检测,检测内容包括牛病毒性腹泻、牛白血病、牛传染性鼻气管炎、牛布鲁氏菌病。本次调查共检测样品204份。其中检测规模场7个,样品116份;检测散养户14个,样品88份。结果表明：检测牛病毒性腹泻病毒血清204份,检出阳性血清65份;检测牛白血病血清188份,检出阳性血清34份;检测牛传染性鼻气管炎血清184份,检出阳性血清64份;检测牛布鲁氏菌病血清204份,检出阳性血清0份。说明三明地区牛群存在多种疫病感染,应采取相应的防控措施。     

荧光光谱法研究头孢硫脒与牛血清白蛋白的相互作用

在模拟生理条件下,用荧光光谱法和紫外-可见吸收光谱法研究头孢硫脒和牛血清白蛋白(BSA)结合反应的特征。研究表明:头孢硫脒与牛血清白蛋白形成复合物,从而猝灭BSA的内源性荧光,该过程为静态猝灭过程。根据Stern-Volmer方程得出了不同温度下结合位点数n和结合常数Ka;结合位点位于BSA的亚结构ⅡA中。通过计算相应的热力学参数,确定了头孢硫脒与牛血清白蛋白之间的作用力主要为氢键和范德华力。利用同步荧光光谱探讨了头孢硫脒与BSA作用前后BSA的构型变化。Hill系数nH<1,表明头孢硫脒有弱的负协同作用。此研究不仅对于揭示体内药物动力学问题和指导临床合理用药具有一定意义,而且对药物分子设计及新药开发等也具有重要指导意义。     

Sheep persistently infected with Border disease readily transmit virus to calves seronegative to BVD virus

Bovine viral diarrhea- and Border disease viruses of sheep belong to the highly diverse genus pestivirus of the Flaviviridae. Ruminant pestiviruses may infect a wide range of domestic and wild cloven-hooved mammals (artiodactyla). Due to its economic importance, programs to eradicate bovine viral diarrhea are a high priority in the cattle industry. By contrast, Border disease is not a target of eradication, although the Border disease virus is known to be capable of also infecting cattle. In this work, we compared single dose experimental inoculation of calves with Border disease virus with co-mingling of calves with sheep persistently infected with this virus. As indicated by seroconversion, infection was achieved only in one out of seven calves with a dose of Border disease virus that was previously shown to be successful in calves inoculated with BVD virus. By contrast, all calves kept together with persistently infected sheep readily became infected with Border disease virus. The ease of viral transmission from sheep to cattle and the antigenic similarity of bovine and ovine pestiviruses may become a problem for demonstrating freedom of BVD by serology in the cattle population.     

Bovine herpesvirus type 1 infection of bovine bronchial epithelial cells increases neutrophil adhesion and activation

Respiratory infection of cattle with bovine herpesvirus type 1 (BHV-1) predisposes cattle to secondary pneumonia with Mannheimia haemolytica as part of the bovine respiratory disease complex (BRD). One cell type that has received limited investigation for its role in the inflammation that accompanies BRD is the respiratory epithelial cell. In the present study we investigated mechanisms by which BHV-1 infection of respiratory epithelial cells contributes to the recruitment and activation of bovine polymorphonuclear neutrophils (PMNs) in vitro. Primary cultures of bovine bronchial epithelial (BBE) cells were infected with BHV-1 and assessed for cytokine expression by real-time PCR. We found that BHV-1 infection elicits a rapid IL-1, IL-8 and TNF-α mRNA response by BBE cells. Bovine PMNs exhibited greater adherence to BHV-1 infected BBE cells than uninfected cells. The increased adherence was significantly reduced by the addition of an anti-IL-1β antibody or human soluble TNF-α receptor (sTNF-αR). Pre-incubation of bovine PMNs with conditioned media from BHV-1 infected BBE cells increased PMN migration, which was inhibited by addition of an anti-IL-1β antibody, sTNF-αR, or an IL-8 peptide inhibitor. Conditioned media from BHV-1 infected BBE cells activated bovine PMNs in vitro as demonstrated by PMN shape change, production of reactive oxygen species and degranulation. PMNs also exhibited increased LFA-1 expression and susceptibility to M. haemolytica LKT following incubation with BHV-1 infected BBE cell conditioned media. Our results suggest that BHV-1 infection of BBE cells triggers cytokine expression that contributes to the recruitment and activation of neutrophils, and amplifies the detrimental effects of M. haemolytica LKT.     

Effects of chemotherapy on immune responses in dogs with cancer

Chemotherapy is assumed to be immunosuppressive; yet to the authors' knowledge, the effects of common chemotherapy protocols on adaptive immune responses in dogs with cancer have not been fully evaluated. Therefore, a study was conducted to evaluate the effects of 2 common chemotherapy protocols on T- and B-cell numbers and humoral immune responses to de novo vaccination in dogs with cancer. Twenty-one dogs with cancer (12 with lymphoma, 9 with osteosarcoma) were enrolled in a prospective study to assess effects of doxorubicin versus multi-drug chemotherapy on adaptive immunity. Numbers of circulating T and B cells were assessed by flow cytometry, and antibody responses to de novo vaccination were assessed before, during, and after chemotherapy. The T- and B-cell numbers before treatment also were compared with those of healthy, age-matched, control dogs. Prior to treatment, dogs with cancer had significantly fewer (P < .05) CD4+ T cells and CD8+ T cells than did healthy dogs. Doxorubicin treatment did not cause a significant decrease in T- or B-cell numbers, whereas treatment with combination chemotherapy caused a significant and persistent decrease in B-cell numbers. Antibody titers after vaccination were not significantly different between control and chemotherapy-treated dogs. These findings suggest that chemotherapy may have less impact on T-cell numbers and ability to mount antibody responses in dogs with cancer than was previously anticipated, though dogs with lymphoma or osteosarcoma appear to be relatively T-cell deficient before initiation of chemotherapy.     

鸭白细胞抗菌肽对小鼠免疫功能的影响

从樱桃谷鸭血液中提取出白细胞并制备粗提抗菌肽,分别以低、中、高3种剂量(质量浓度分别为1.5 g/L、7.5 g/L、15 g/L)灌胃清洁级昆明系小鼠,0.2 mL/(d·只),同时设0.0l%醋酸溶液对照组和蛋白对照组(10 g/L牛血清白蛋白).连续灌胃14 d后,测定小鼠的免疫器官指数、E玫瑰花环形成率、碳粒廓...     

Breakdown severity during a bovine tuberculosis episode as a predictor of future herd breakdowns in Ireland

A retrospective cohort study of Irish cattle herds investigated whether the severity of a herd’s bovine tuberculosis (BTB) breakdown was a predictor of the hazard of a future BTB breakdown in that herd. Data on 10,926 herds not having had BTB in 1995 (the “non-exposed” group) were obtained using a 10% random sample from all herds without BTB in 1995. Data on 6757 herds that had a new BTB breakdown in 1995 (the “exposed” group) were obtained and categorized into five increasing exposure-severity classes based on the total number of standard reactors (to the single intra-dermal comparative cervical tuberculin test) detected during the breakdown. Exposed herds were deemed to be free of BTB after they passed a 6-month check test; non-exposed herds were deemed free as of the date of the first negative herd-test in 1995.

In the 5 years after 1995, 18% of the non-exposed herds had a BTB breakdown, whereas 31% of the exposed herds had a subsequent breakdown. Relative to the hazard for non-exposed herds, the hazard for the first future singleton standard reactor breakdown, was 1.6-times higher for exposed herds with only 1 standard reactor in 1995, and 1.8-times higher for those exposed herds with 4–8 standard reactors during the 1995 episode. When the outcome for future breakdowns was 2 or more standard reactors, the hazard ratios ranged from 1.6 for exposed herds with only 1 standard reactor in 1995 up to 2.9 in exposed herds with 8 or more standard reactors during the 1995 episode. The latter hazard ratio varied over time, decreasing to 1.7 after 3 years of risk. The hazard of a future BTB breakdown increased directly with number of cattle in the herd, a positive history of previous BTB in the herd, and the local herd prevalence of BTB. The presence of confirmed BTB lesions in reactor cattle was not predictive of the future breakdown hazard when the effects of other factors were controlled.     

Efficacy of a modified live intranasal bovine respiratory syncytial virus vaccine in 3-week-old calves experimentally challenged with BRSV

Two experimental bovine respiratory syncytial virus (BRSV) challenge studies were undertaken to evaluate the efficacy of a single intranasal dose of a bivalent modified live vaccine containing BRSV in 3-week-old calves. In the first study, vaccine efficacy was evaluated in colostrum deprived (maternal antibody negative) calves 5, 10 and 21 days after vaccination. Nasal shedding of BRSV was significantly reduced in vaccinated calves challenged 10 or 21 days after vaccination. Virus excretion titres were also reduced in vaccinates challenged 5 days after vaccination but reduction in duration of shedding and total amount of virus shed were not statistically significant. Clinical disease after challenge in this study was mild. In the second study, vaccine efficacy was assessed in calves with maternal antibodies against BRSV by challenge 66 days post-vaccination. Vaccination significantly reduced nasal shedding after challenge and the severity of clinical disease was also reduced.