Managemental influences on the selective proliferation of two strains of haemolytic Escherichia coli in weaned pigs

In an experimental study on a piggery it was found that haemolytic Escherichia coli of O-serotypes 138 or 139 proliferated in the intestinal tracts of pigs following weaning, with E. coli of the O-138 type also being occasionally recovered from unweaned pigs, and once from a sow. Organisms of the O-138 type produced heat labile enterotoxin and their presence in weaned pigs was associated with the development of severe post-weaning diarrhoea. E. coli of O-139 type produced a vero cell cytotoxin and were associated with a milder diarrhoea in weaned pigs. Under various managemental circumstances the O-138 type E. coli almost invariably proliferated after weaning. The O-139 strain of E. coli did however proliferate rather than the O-138 strain following the movement of weaned pigs to new accommodation, after weaned pigs were returned to their sow and then weaning again 5 days later, and very occasionally in pigs weaned at 5 weeks of age. In all these cases earlier proliferation of the O-138 E. coli had been detected, suggesting that this may be a prerequisite for proliferation of the O-139 strain.     

Ischemia and reperfusion reduce the endogenous basic fibroblast growth factor in rat skeletal muscles: an immunohistochemical study.

Polyclonal antibodies directed against human recombinant basic fibroblast growth factor were used in immunohistochemical studies to localize this growth factor in normal and wounded rat skeletal muscles. According to the intensity of the stain, three main classes of fibers could be identified: the strongly, moderately, and weakly stained fibers. Basic fibroblast growth factor immunoreactivity was found mainly in the extracellular matrix, primarily in the endomysium, which includes the heparin-containing basal lamina, and also in the capillary basal membrane of both normal and wounded muscles; however, the signal intensity was much stronger in normal muscles. The distribution of basic fibroblast growth factor in wounded muscles became markedly heterogeneous and sparse. After 4 hours of ischemia, about 40% of skeletal muscle fibers lost their basic fibroblast growth factor immuno-reactivity. Muscles which underwent 4 hours of ischemia and 24 hours of reperfusion had only a diminished basic fibroblast growth factor immunoreactivity. The pathologic results supported the concept of destroyed cell connection and fiber necrosis in ischemic and reperfused muscles. Potential mechanisms involved in this reduced concentration of basic fibroblast growth factor in wounded muscles may include oxygen free radical activation, a generalized effect of the inflammatory response, and reduced secretion of endogenous basic fibroblast growth factor. These results are only partially compatible with the established mitogenic role of this growth factor and suggest that a reduction of endogenous fibroblast growth factor may partly contribute to a delay in wound healing.     

Differential effects of galactose-induced cataractogenesis on the soluble crystallins of rat lens

Soluble lens crystallins from 6-10-week-old, galactose-fed, male Sprague-Dawley rats were analyzed by two-dimensional polyacrylamide gel electrophoresis at each of the five Sippel stages of cataractogenesis. Electrophoretograms were compared with similarly analyzed crystallins from comparably aged, chow-fed controls. Polypeptides were assigned to crystallin families and subfamilies on the basis of chromatographic fractionations with Sephadex G-200, superfine. Staining intensities of polypeptides from control lenses remained essentially unchanged throughout the experimental period, while those of the polypeptides from cataractous lenses showed non-uniform changes. Staining of the genomic gamma-crystallins increases up to at least stage 3; by stage 4, staining of gamma-chains, with perhaps those of gamma 5 and gamma 6 excepted, diminishes and in the total cataract, staining of all chains is further reduced. With possibly the addition of one chain, the total number of postsynthetically modified gamma-crystallins in cataractous lenses does not exceed that in the comparably aged normal lens. The genomic alpha- and beta-crystallin polypeptides are sustained close to normal levels up to stages 3 or 2, respectively, after which their gradually falling levels are accompanied by the generation of new species or elevated levels of existing post-translational species. An exception to this behavior is the rapid and total loss of beta B1a, a genomic subunit implicated in the aggregation of beta H-crystallins. Charge heterogeneity and variable pI displayed by beta B1a and other highly cationic beta- and gamma-crystallin polypeptides can be induced during isoelectric focusing and may be due to thiol group oxidation.     

人精液中ABH血型物质分泌强度的研究

本文采用中和试验、沉降反应和解离试验对１３５例已知血型人精液中ＡＢＨ血型物质的分泌强度进行了检验，并将其分为强、中、弱三型。这对区别个人血型物质含量及性犯罪的法医学鉴定均有重要意义。并证明了ＡＢ型人精液中Ａ、Ｂ血型物质含量不均等现象，并且绝大多数人Ｂ型物质高于Ａ型物质。     

急性视神经炎47例临床分析

分析了1984～1993年期间47例经治的急性视神经炎患者。治疗应用地塞米松10mg、青霉素480万u静脉点滴7天，随后减量。结果治愈35例（74．47％），好转6例（12．76％），无效2例（4．26％），转院及自动出院各2例。47例中11例治疗效果不好者行筛窦开放术后，视力逐渐恢复正常，显示筛窦开放术有其临床实用价值。     

改良V-W成形矫正内眦赘皮

目的寻求一种简单有效的内眦赘皮矫治方法.方法采用改良V-W成形,即赘皮皮肤的V-W推进改形,加上新内眦点与鼻根外侧的筋膜或骨膜固定、松解皮下粘连、修整错构的眼轮匝肌等,全面治疗内眦赘皮.大部分病例与重睑术同期进行.结果1999年至今矫治明显的内眦赘皮67例,术后效果满意.术后1个月有5例出现内眦部切口增生发红,3-4月逐渐软化消退.所有病例随访1个月到1年,均获得满意疗效.结论改良V-W成形手术切口设计简单明了,术后内眦形态良好,不易复发,瘢痕不显,是矫正内眦赘皮较理想的方法.     

白细胞介素-4和γ-干扰素基因联合治疗胶质瘤

目的 探讨逆转录病毒载体介导的白细胞介素(IL)-4和γ-干扰素(IFN)基因联合治疗胶质瘤的作用。方法构建携带IL-4或IFN-γ基因的逆转录病毒载体，将其导入逆转录病毒包装细胞；将携带IL-4和IFN-γ基因的逆转录病毒包装细胞分别或联合注射到脑内荷瘤大鼠的肿瘤组织中，观察其治疗作用。结果成功获得携带治疗基因的逆转录病毒包装细胞PA317IFN-γ和PA317IL-4，所产病毒滴度分别为2x10^6cfu／ml和2．5x10^6cfu／ml。包装细胞瘤内注射能够诱导大鼠产生抗肿瘤免疫反应，杀伤肿瘤细胞，联合应用具有协同治疗作用。结论携带IL-4或IFN-γ基因的逆转录病毒包装细胞瘤内注射是一种有效的胶质瘤基因治疗方法，两者联合应用具有协同治疗作用。     

甲基强的松龙冲击疗法治疗重型脱髓鞘脑病患者的护理

采用大剂量甲基强的松龙治疗脱髓鞘脑病患者１５例。在治疗过程中，积极预防应激性溃疡，加强呼吸道及人工冬眠护理。经５次治疗，１４例症状明显改善。     

Region-specific growth properties and trophic requirements of brain- and spinal cord-derived rat embryonic neural precursor cells

To determine whether neural precursor cells have region-specific growth properties, we compared the proliferation, mitogenicity, and differentiation of these cells isolated from the embryonic day 16 rat forebrain and spinal cord. Neural precursor cells isolated from both regions were cultured in growth medium supplemented with epidermal growth factor, basic fibroblast growth factor, or epidermal growth factor+basic fibroblast growth factor. Under all three conditions, both neural precursor cell populations proliferated for multiple passages. While spinal cord-derived neural precursor cells proliferated moderately faster in epidermal growth factor-enriched growth medium, brain-derived cells proliferated much faster in basic fibroblast growth factor-enriched growth medium. When exposed to both epidermal growth factor and basic fibroblast growth factor, the two neural precursor cell populations expanded and proliferated more rapidly than when exposed to a single factor, with brain-derived neural precursor cells expanding significantly faster than spinal cord-derived ones (P<0.0001). Differentiation studies showed that both neural precursor cell populations were multi-potent giving rise to neurons, astrocytes, and oligodendrocytes. However, neuronal differentiation from brain-derived neural precursor cells was greater than spinal cord-derived ones (11.95+/-5.00% vs 1.92+/-1.13%; passage 2). Further, the two neural precursor cell populations differentiated into a similar percentage of oligodendrocytes (brain: 8.66+/-5.85%; spinal cord: 7.69+/-3.91%; passage 2). Immunofluorescence and Western blot studies showed that neural precursor cells derived from both regions expressed receptors for basic fibroblast growth factor and epidermal growth factor. However, brain-derived neural precursor cells expressed higher levels of the two receptors than spinal cord-derived ones in growth medium containing epidermal growth factor+basic fibroblast growth factor. Thus, our results showed that neural precursor cells isolated from the two regions of the CNS have distinct properties and growth requirements. Identifying phenotypic differences between these neural precursor cell populations and their growth requirements should provide new insights into the development of cell therapies for region-specific neurological degenerative diseases.