Vaccination of calves with Mycobacteria bovis Bacilli Calmete Guerin (BCG) induced rapid increase in the proportion of peripheral blood γδ T cells

Changes in the proportion of peripheral blood T cell subsets after subcutaneous inoculation of cattle with Mycobacterium bovis Bacille Calmette-Guerin (BCG) were studied. Calves were injected with approximately 8 × 10⁶ BCG bacillus and blood samples collected at weekly intervals for flow-cytometric analyses to determine the proportion of CD4⁺, CD8⁺ and γδ T cells. In addition, whole blood samples were stimulated in vitro with M. bovis purified protein derivative (PPD) and the secreted IFN-γ quantified by ELISA. Results showed cellular and cytokine changes which could be categorized into three phases. The first phase occurred within the first 2 weeks after vaccination involving an increase in proportion of WC1⁺ γδ T cells and a concomitant increase in the secretion of IFN-γ. These two responses peaked at 2 weeks and waned thereafter. The second phase involved an increase in the CD4/CD8 ratio as a result of an increase in the proportion of CD4⁺ T cells between 4 and 6 weeks. The third phase involved a decrease in the CD4/CD8 ratio due to an increase in the proportion of CD8⁺ T cells between 8 and 10 weeks. Surprisingly, the IFN-γ response was associated with changes in the γδ rather than the CD4⁺ or CD8⁺ T cells, suggesting that this cytokine was secreted by γδ-T cells. These results are consistent with the reported ability of γδ T cells to act rapidly and bridging the innate and classically adaptive immune responses.     

Kit receptor tyrosine kinase dysregulations in feline splenic mast cell tumours

This study investigated Kit receptor dysregulations (cytoplasmic immunohistochemical expression and/or c‐KIT mutations) in cats affected with splenic mast cell tumours. Twenty‐two cats were included. Median survival time was 780 days (range: 1–1219). An exclusive splenic involvement was significantly (P = 0.042) associated with longer survival (807 versus 120 days). Eighteen tumours (85.7%) showed Kit cytoplasmic expression (Kit pattern 2, 3). Mutation analysis was successful in 20 cases. Fourteen missense mutations were detected in 13 out of 20 tumours (65%). Eleven (78.6%) were located in exon 8, and three (21.6%) in exon 9. No mutations were detected in exons 11 and 17. Seven mutations corresponded to the same internal tandem duplication in exon 8 (c.1245_1256dup). Although the association between Kit cytoplasmic expression and mutations was significant, immunohistochemistry cannot be considered a surrogate marker for mutation analysis. No correlation was observed between c‐Kit mutations and tumour differentiation, mitotic activity or survival.     

Evaluating the efficacy of an attenuated Streptococcus equi ssp. zooepidemicus vaccine produced by multi-gene deletion in pathogenicity island SeseCisland_4

Streptococcus equi ssp. zooepidemicus(SEZ) is a pathogen associated with a wild range of animal species. Frequent outbreaks have occurred in recent years in pigs, horses, goats and dogs which is liable to infect humans. There is a lack of efficient vaccines against this disease and the occurrence of antibiotic resistance may render drug therapies ineffective. In this study, gene deletion mutant(ΔSEZ) in pathogenicity islands SeseCisland_4 was constructed. The mutant ΔSEZ had a 52-fold decrease in 50% lethal dose(LD_(50)) and had less capacity to adhere epithelial cells. Importantly, immunization of mice with attenuated vaccine ΔSEZ at the dose of 10~2 colony-forming units(CFU) mL~(–1) elicited a significant humoral antibody response, with an antibody titer of 1:12 800. Therefore, 10~2 CFU mL~(–1) might be used as the appropriate immune dose for the attenuated vaccine ΔSEZ, which provided mice with efficient protection against virulent SEZ. In addition, the hyperimmune sera against 10~2 CFU m L–1 attenuated vaccine ΔSEZ could confer significant protection against virulent SEZ infection in the passive immunization experiment and exhibited efficient bactericidal activity in the whole blood assay. Meanwhile, no viable bacteria was detected in blood when mice were immunized with ΔSEZ at the dose of 10~2 CFU mL~(–1) via hypodermic injection. Thereafter, the mutant ΔSEZ at the dose of 10~2 CFU mL~(–1) could confer significant protection in mice and had less negative effects on host, which could be an effective attenuated vaccine candidate for the prevention of SEZ.     

油量计量的微计算机控制

讨论了运用ＣＭＣ－８０双板机控制成品油库发油计量的原理和实现方法，该控制装置已在实际系统中使用。     

小鼠CD19基因部分片段的克隆及其鉴定

[目的]为了研究小鼠CD19胞膜外区的结构与功能。[方法]应用反转录—聚合酶链式反应技术(RT-PCR),通过一对自行设计的引物,从小鼠脾脏RNA中扩增出一条特异性基因片段,大小约为910 bp,对该片段进行酶切和测序鉴定。[结果]所获得的DNA片段的酶切位点与所报道的小鼠CD19基因一致,从而确定其为小鼠CD19胞膜外区基因。[结论]该研究为小鼠CD19胞膜外区的结构与功能的进一步研究提供了试验基础。     

羊痘病毒P32基因与羊CD58基因共表达载体的构建

为了开发出一种可行的羊痘基因疫苗,尝试用羊P32基因与CD58基因建立共表达载体.试验根据GenBank中收录的羊痘病毒(GPV)P32和羊CD58基因组序列,设计了扩增GPV P32基因和CD58基因的特异性引物,运用PCR技术从GPV中扩增出P32基因,从羊的外周血中扩增出CD58基因,并将其分别克隆到pMD18-T载体,测序正确.将P32基因去掉后端疏水区一段与CD58基因先后克隆至载体pBudCE4.1,并转化大肠埃希菌JM109,提取质粒通过酶切鉴定和测序正确,且读码框正确.说明成功获得了真核共表达质粒pBudCE4.1/CD58/P32.     

随书附盘有效利用的实用性对策

分析了几种传统随书附盘管理模式存在的问题,设想全校各个学院共建随书附盘数据库,提出了有效利用的实用性对策。     

中俄输气管道技术方案研究

根据中俄输气管道工程可行性研究报告中的基础参数,通过对输气工艺的水力计算、X70和X80两种钢级用管壁厚计算以及投资对比分析,提出了未来中俄输气管道项目可采用的输送技术方案,并根据管道建设的需要,提出了当前应积极组织X80级管道钢应用研究的建议。     

Steam explosion of crop straws improves the characteristics of biochar as a soil amendment

Five crop straws(wheat, rice, maize, oil-rape, and cotton) were first steam-exploded for 2 min at 210°C, 2.5 MPa and then pyrolyzed at 500°C for 2 h. Steam explosion(SE) induced 47–95% and 5–16% reduction of hemicellulose and cellulose, respectively, in the crop straws. The biochars derived from SE-treated feedstocks had a lower specific surface area(SSA) and pore volume, compared to those from pristine feedstocks, with one exception that SE enhanced SSA of oil-rape straw biochar by approximately 16 times. After SE, biochars had significant higher anion exchange capacity(AEC)(6.88–11.44 cmol kg~(–1)) and point of zero net charges(PZNC)(pH 3.61–5.32) values. It can thus be speculated that these biochars may have higher potential for anions adsorption. In addition, oil-rape straw might be suitable to SE pretreatment for preparing biochar as a soil amendment and sorbent as well. Further work is required for testing its application in soil.     

CD58对猪PBMC转化的作用

应用ＭＴＴ比色法,测定了由ＳＲＢＣ膜及ＰＲＢＣ膜提取的ＣＤ５８对猪ＰＢＭＣ转化的影响。结果证明,两种ＣＤ５８成分均能显著提高ＰＨＡ－Ｐ对ＰＢＭＣ的激活作用（Ｐ＜０．０１或Ｐ＜０．０５）,单独应用也表现出对ＰＢＭＣ的活化效应,且上述作用具有剂量依赖性。ＣＤ５８浓度达２．５ｇ·Ｌ－１时作用最强（Ｐ＜０．０５）,超过该浓度则活化作用减弱,其作用的规律与ＲＢＣ一致。比较分析表明,猪源ＣＤ５８在最佳剂量时,单独刺激作用或对ＰＨＡ－Ｐ诱导的ＰＢＭＣ转化的协同作用均显著大于绵羊源ＣＤ５８（Ｐ＜０．０５）,ＰＲＢＣ的协同刺激作用也大于ＳＲＢＣ．