Bovine cumulus-oocyte disconnection in vitro

Summary Cumulus-oocyte complexes were obtained from cows by aspiration of small (1–6 mm in diameter) antral follicles after slaughter. Complexes with a compact multilayered cumulus investment were cultured and processed for transmission electron microscopy after different periods of culture including a 0 h control group. In 0 h control oocytes the cumulus cells had numerous projections which penetrated the zona pellucida and established gap junctions with the oolemma. A partial loss of these junctions was noticed as an early event of oocyte maturation occurring within the first 3 h of culture. A low frequency of gap junctions was maintained until 12–18 h of culture where the junctional contact was completely disrupted. This decrease in intercellular communication was parallelled by resumption of oocyte meiosis.     

牛骨形成蛋白在骨不连中的临床应用

应用牛骨形成蛋白（ｂｏｖｉｎｅＢｏｎｅＭｏｒｐｈｏｇｅｎｅｔｉｃＰｒｏｔｅｉｎ简称ｂ－ＢＭＰ）成功的治愈１３例骨不连病人。经过１３个月～２９个月随访观察，效果较好。本组病人术前平均已做过１．５次手术。１３例病人中，有１２例被１次治愈。１例病人再次行内固定加用牛骨形成蛋白的植入也被治愈。骨形成蛋白的应用方式，采用同锻石膏复合后植入骨不连处。平均每个病人植入１００ｍｇＢＭＰ，１３例病人平均治愈时间为４．７个月。术后没有任何并发症。     

The comparative evaluation of cellular localization of viral antigens with microscopic changes in the ileum of cattle infected with bovine viral diarrhea

The correlation between microscopic changes with cellular localization of viral antigens was studied in the ileum of 16 cases infected with bovine viral diarrhea virus (BVDV). Microscopic lesions in the ileum included multifocal erosive and ulcerative ileitis, severe congestion and hemorrhage, crypt dilation and mucus engorgement, epithelial debris and leukocytes, lymphoid depletion of Peyer’s patches, herniation of mucosal epithelium into depleted Peyer’s patches, and fibrinoid vasculitis of submucosal vessels. BVDV antigen was detected by immunohistochemistry in macrophages, dendritic cells, smooth muscle cells, endothelial cells, epithelial cells of crypts, and mucosal epithelium, together with other mononuclear cells including lymphocytes, plasma cells, fibroblasts, and intramural ganglial cells. No consistent correlation between the presence of BVDV antigen and vascular lesions in the ileum was identified. The intensity and distribution of the immunoperoxidase stain in the ileum was graded as highly positive (18.7%), moderately positive (56.3%), and mildly positive (25%). In conclusion, the pattern and density of distribution and localization of BVDV antigen in the ileum was not consistently correlated with the severity of microscopic lesions.     

牛初乳复合细胞营养因子（CHF）的体内,外抗菌作用研究

牛初乳复合细胞营养因子（ＣＨＦ）对伤寒杆菌、大肠杆菌、白色葡萄球菌、变形杆菌、绿脓杆菌、福氏痢疾杆菌６种肠道常见致病菌均有一定的正常凝集效价，其中对大肠杆菌和绿脓杆菌的凝集效价与人γ－球蛋白相同。体外试验表明ＣＨＦ对白色葡萄球菌和福氏痢疾杆菌有一定的抑菌作用，且这种抑菌作用不依赖补体的参与。ＣＨＦ可促进小鼠体内抗绿脓杆菌的免疫保护作用，当绿脓杆菌的攻击量达２．８×ＬＤ５０时，就有非常显著的作用，且强度与人γ－球蛋白相似。     

Are transforming properties of the bovine papillomavirus E5 protein shared by E5 from high-risk human papillomavirus type 16?

The E5 proteins of bovine papillomavirus type 1 (BPV-1) and human papillomavirus type 16 (HPV-16) are small (44-83 amino acids), hydrophobic polypeptides that localize to membranes of the Golgi apparatus and endoplasmic reticulum, respectively. While the oncogenic properties of BPV-1 E5 have been characterized in detail, less is known about HPV-16 E5 due to its low expression in mammalian cells. Using codon-optimized HPV-16 E5 DNA, we have generated stable fibroblast cell lines that express equivalent levels of epitope-tagged BPV-1 and HPV-16 E5 proteins. In contrast to BPV-1 E5, HPV-16 E5 does not activate growth factor receptors, phosphoinositide 3-kinase or c-Src, and fails to induce focus formation, although it does promote anchorage-independent growth in soft agar. These variant activities are apparently unrelated to differences in intracellular localization of the E5 proteins since retargeting HPV-16 E5 to the Golgi apparatus does not induce focus formation.     

牛IL-18基因的克隆及遗传进化分析

目的：克隆牛白细胞介素18（IL-18）全基因，并对其进行序列分析。方法：从ConA刺激培养的牛外周血淋巴细胞提取总RNA，利用巢式RT-PCR方法扩增出牛IL-18全长cDNA，将其克隆到pMDl8-T载体上，测序后进行序列分析。结果：成功地克隆到了牛IL-18全基因，序列分析表明，实验中所克隆到的牛IL-18序列与GeneBank所登录的牛IL-18核苷酸序列及其推导氨酸序列同源性分别是99．5％和99％。与人、猕猴、野猪、山羊属、马等核苷酸序列及其推导氨基酸序列同源性分别在84．9％-99．5％和74．9％～99％之间，研究结果在国内还未见报道。结论：成功地从牛外周血中克隆到了牛IL-18的基因，其全长为598bp。     

Morphogenesis of the bovine rete testis: extratesticular rete, mesonephros and establishment of the definitive urogenital junction

The development of the extratesticular rete, the regression of the mesonephros and the establishment of the urogenital junction between rete testis and efferent ductules were investigated in 67 bovine embryos and fetuses collected in the period from day 29 through day 250 post conception. The results were obtained by immunohistochemistry and by the study of semithin sections. At about day 30, the large mesonephros contains a peculiar Malpighian body in its cranial part, generally referred to as the mesonephric giant corpuscle, which is connected to the Wolffian duct by a series of well-developed and functioning mesonephric tubules. This set of primary mesonephric tubules, however, will not participate in the formation of the definitive urogenital junction, but will regress and soon disappear completely. The efferent ductules in the bovine are represented by another set of secondary mesonephric tubules that grow out from the dorsal aspect of the mesonephric giant corpuscle at about day 50. Transiently, the lumina of the sprouting efferent ductules are plugged by invading intraductular blood vessels, probably representing rudimentary glomeruli. The proximal portions of the newly-formed efferent ductules establish side-to-end contacts with extensions of the extratesticular rete that has bypassed the regressing giant corpuscle. At 85 days, the efferent ductules have reached the Wolffian duct and open into it. At 150 days, the channels of the extratesticular rete display a patent lumen and now form end-to-end anastomoses with the efferent ductules. The proliferating mesenchymal cells surrounding the epithelia of the efferent ductules have arranged in several concentric layers at about 85 days. These mesenchymal cells are the precursors of the periductular musculature and are reached by the first nerve fibers at about day 130. Accepted: 13 December 2000     

Current perspectives on bovine spongiform encephalopathy and variant Creutzfeldt–Jakob disease

Bovine spongiform encephalopathy (BSE) clearly originated in the UK, where there have now been more than 180 000 cases. However, through the exportation of cattle and cattle-feed additives from the UK, BSE also became established to a lesser extent in other European countries. There is current concern that BSE might have been distributed more widely as a result of the exportation of cattle or BSE-infected feed or foodstuff not only from the UK but also from other European countries that later became affected. It is now recognized that the transmissible agent that causes BSE also causes a new variant form of Creutzfeldt–Jakob disease (vCJD) in humans, and the evidence for this is presented. This probably resulted from dietary exposure to the bovine agent, and the potential role of mechanically recovered meat is discussed. There is a brief discussion on the controversial issue of the nature of the causal agents of diseases like BSE and vCJD. Whether or not sheep or goats could have become infected with BSE, and whether they represent a human health hazard, is also debated. Finally, the question of the control of BSE, and consequently vCJD, is discussed with regard to the rigorous application of the relevant regulations.