The development of resistance in different inbred strains of mice to infection with Nematospiroides dubius

Infection by the intestinal nematode parasite Nematospiroides dubius was studied in seven different inbred mouse strains. Although there was some minor variation in the susceptibility of the different strains to a primary infection there were marked differences in their ability to develop resistance to infection following repeated exposure to infective larvae. The strains of mice which developed the best resistance also expelled adult worms arising from the previous infections. The adult worms resulting from a primary infection were slowly eliminated in two inbred strains studied whereas no loss occurred from outbred LACA mice. Although males and females of two strains, C3H/HeJ and CBA/H were equally susceptible to a primary infection, the females developed better resistance than the male mice following two oral administrations of third stage larvae. Infected mice of every strain and both sexes contained high levels of IgG1 in the serum.     

骨骼肌缺血再灌注损伤及发病机制初探

目的：探讨骨骼肌缺血再灌注损伤过程的微循环变化。组织学改变以及多肽含量变化和意义。方法：42只雄性大鼠随机分为留伴行神经组和去伴行神经组,建立标准骨骼肌缺血再灌注模型,采用激光多谱勒及显微放大分析系统,组织学方法以及凝胶电泳方法等观察缺血再灌注损伤变化。结果：缺血再灌注损伤后的骨骼肌微血管管径在20分钟时恢复率基本达到高峰约60％,此后为平台期：90分钟最高峰,为75％,主干血管流速率亦在20分钟基本达到上限,病理检查显示：缺血的骨骼肌纤维呈空泡状,核形态增大,染色加深,红细胞严重聚集,凝胶蛋白电泳提示：缺血骨骼肌中分子量20KD左右的多肽显著增加。结论：骨骼肌缺血再灌注损伤发生后,骨骼肌的微循环发生不同程度的破坏,及因之导致骨骼结构损伤和异常的20KD多肽含量明显增加,以及红细胞凝聚,白细胞的改变,这些共同构成了缺血再灌注损伤机制。     

Morphologic features and biological properties of melanomas in children

A complex morphologic study was made of primary skin melanoma, its metastases to the lymph nodes in a boy of 8, as well as of the tumour inoculate from the lymph node of the child on nude mice BALB/c in passages 1-6, 9, 10 and 44. The mitotic regimen of the material was studied. The data obtained show that childhood and adult melanoma is characterized by the same clinical-morphologic features. The electron microscopic study provided additional information for the confirmation of the histogenesis and identification of the melanoma type. To study individual sensitivity to antitumour drugs, it might be more reasonable to use first passages of the tumour, as the ultrastructural cell differentiation in them is maximally similar to the original one.     

Electron microscopic evidence of persistent chlamydial infection following treatment

Chlamydia trachomatis infections of the female and male genital tracts are often asymptomatic and, thus, tend to become persistent. In the persistent state the typical Chlamydia life cycle is arrested and standard antibiotic regimens do not always eradicate this infection. We sought to relate treatment failures in men and women with persistent chlamydial genital tract infections to electron microscopic evidence of chlamydial persistence and with atypical morphological forms of the organism. Of 16 patients with chlamydial persistence following azithromycin treatment, morphological variants of this organism were observed by electron microscopy from one endocervical sample and one male urethral sample. We document the presence of intracellular inclusions containing only reticulate bodies, extracellular monomembrane and polymembrane phagosomes containing elementary bodies and reticulate bodies with abnormal outer membranes in the process of dividing extracellularly. These observations parallel previous in vitro studies of chlamydial persistence under adverse conditions. This capacity of C. trachomatis to undergo atypical morphological alterations in vivo may contribute to its persistence and relative resistance to antibiotics.     

Track membranes in the filtration technique of determination of the quality of water from bacteriological values

The paper describes a new class of microfiltration track membranes (TMs) proposed for laboratories to carry out a sanitary water bacteriological test. TMs have a strictly reference pore structure, a low sorption capacity do not contain the components that able to migrate into the filtrate, they are noted for a screening mechanism of holding microparticles onto the surface. The TMs made in Russia, the reticular membranes "Vladipore", and the foreign Millipore membranes certified by the international standards were comprehensively assessed. TMs are superior to the membranes manufactured in Russia at the moment in a number of basic properties that are most essential for the study of water quality and to foreign certified membranes in physical parameters, the specific features of growth of coliform bacteria, the rate of performance of an oxidase test, and the efficiency of retention of various microorganisms.