安徽省部分地区牛衣原体的血清学调查

牛衣原体病是由鹦鹉热衣原体引起的一种接触性人兽共患传染病。本调查采用间接血凝法(IHA)对安徽省部分地区的535份牛血清进行了衣原体抗体检测,结果显示,血清抗体阳性率为22.43%(120/535);4个奶牛场的群阳性率为75%,个体阳性率为23.21%(68/293);9个肉牛场的群阳性率为88.9%,个体阳性率为21.49%(52/242)。对不同用途、不同年龄段、不同购入来源以及不同送检地区的牛衣原体抗体阳性率进行统计分析。结果表明安徽省的牛群中存在不同程度的衣原体感染。IHA法检测衣原体抗体简便、快速,适合在基层推广。     

牛病毒性腹泻-粘膜病病毒TaqMan荧光定量RT-PCR检测方法的建立及初步应用

为建立-种牛病毒性腹泻-粘膜病病毒（BVDV）的快速检测方法,根据GenBank中登录的BVDV基因序列,针对5’UTR的保守序列,设计合成了一对特异性引物和一条TaqMan荧光探针。通过对反应条件和反应体系进行优化,建立了一种能快速定量检测BVDV的荧光定量RT—PCR检测方法。通过对20份胎牛血清样品和猪瘟细胞苗半成品进行检测,对该方法的特异性、敏感性和重复性进行试验。结果显示,建立的方法能检测到BVDV,而对CSFV、PRRSV和MDBK细胞的扩增结果均为阴性,具有高度的特异性。在所检测的20份样品中,BVDV阳性6份（30％）。对所构建的标准品进行检测,在10^2-10^8拷贝／μL的范围内可以得到良好的动力学曲线,能检测低至10^3-10^4拷贝／mL的病毒量。表明所建立的检测方法具有快速、特异、灵敏、重复性好等特点,可用于临床及科研中对BVDV的快速定量检测和对牛血清及猪瘟兔化弱毒疫苗等生物制品中是否污染BVDV进行监测。     

子宫内膜炎患牛唾液生化变化的初步研究

[目的]探究子宫内膜炎患牛唾液生物标志物特点,[方法]研究收集试验组子宫内膜炎患牛和对照组健康奶牛唾液,针对所选10种生物标志物使用相关试剂盒在自动生化分析仪上进行检测,并将所得数据进行对比分析。[结果]相比健康奶牛,子宫内膜炎患牛唾液生物标志物的升高项为α唾液淀粉酶、皮质醇、乳酸和尿酸,而腺苷脱氨酶、乙酰胆碱酯酶水平、pH值、钠钾比则下降明显。[结论]说明应激、炎症和氧化应激在患子宫内膜炎奶牛体内的存在,钠营养状况略受影响。     

Studies on Bovine Leukosis

Summary

An enzyme linked immunosorbent assay (ELISA) and the agar gel immunodiffusion test with bovine leukosis virus glycoprotein as antigen (AGIDT‐BLV gp) were further used to test 633 bovine sera for antibodies to BL V. Both tests detected the same number of sera positive (149) or negative (464) for antibodies. Nine sera were negative in the ELISA but found to be weakly positive (2 sera) or bending the control line (7) in the AGIDT‐BLV gp. On the other hand 11 sera were scored negative in the AGIDT‐BLV gp but were weakly positive (9 sera), positive (1), and strongly positive (I) in the ELISA. Both tests are used routinely in this Institute as they complement each other, specially if sera with low antibody titers are under investigation. It is concluded that ELISA can fully replace radioimmunoassays in the serodiagnosis of enzootic bovine leukosis.     

Monitoring and identification of residues of anabolic preparations in slaughtered cattle by HPLC with diode array detection

Summary

The new combination of isocratic high performance liquid chromatography (HPLC) with on line UV spectrum detection via a diode array configuration has been applied to the detection and identification of anabolics present in application sites of cattle.

Combination of the characteristic retention time in the HPLC chromatogram and a comparison of the full spectrum between 190–400 nm of the anabolic components with that of a standard resulted in a very reliable identification. By means of this method 117 samples of application sites were investigated for the presence of anabolic residues. Of the xenobiotic anabolics, 19‐nortestosterone (NT) was found most frequently (in 96 cases), whereas diethylstilbestrol (DES) was found in only 11 cases.

In all samples the identification of NT and DES was confirmed by high resolution gas chromatography‐mass spectrometry (GCMS).     

Role of estrogen receptor-α (ESR1) and the type 1 insulin-like growth factor receptor (IGFR1) in estradiol-stimulated proliferation of cultured bovine satellite cells

Although the exact mechanism(s) by which estradiol (E₂) enhances muscle growth in a number of species, including humans and cattle, is not known, E₂ treatment has been shown to stimulate proliferation of cultured bovine satellite cells (BSCs). This is particularly significant because satellite cells are the source of nuclei needed to support postnatal muscle fiber hypertrophy and are thus crucial in determining the rate and extent of muscle growth. The objective of this study was to assess the role of estrogen receptor-α (ESR1) and the type 1 insulin-like growth factor receptor (IGFR1) in E₂-stimulated proliferation of cultured BSCs. To accomplish this, we have used small interfering RNA (siRNA) to silence expression of ESR1 or IGFR1 and assessed the effects on E₂-stimulated proliferation in BSC cultures. In BSCs treated with nonspecific siRNA, E₂ significantly (P < 0.05) stimulates proliferation under conditions in which neither IGF-1 nor IGF-2 expression is increased; however, treatment of ESR1- or IGFR1-silenced cells with E₂ does not significantly stimulate proliferation. These results indicate that both ESR1 and IGFR1 are required for E₂ to stimulate proliferation in BSC cultures. The fact that this occurs under culture conditions in which neither IGF-1 nor IGF-2 mRNA expression is increased strongly suggests that E₂ activates IGFR1 via a mechanism that does not involve increased IGF-1 or IGF-2 binding to the receptor.