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11.
实验冻伤大鼠神经纤维的超微结构改变   总被引:2,自引:1,他引:1  
为探讨冷冻损伤发生、发展及转归的规律,采用健康Wistar大鼠,分为冻伤组(20只)和对照组(5只)。电镜下观察大鼠后肢冷冻至-20℃后即刻、4小时、24小时及72小时时周围神经的超微结构改变。冻后即刻,神经髓鞘即出现轻度变性;冻后1~24小时,有髓神经雪旺细胞及轴突严重变性,而无髓神经变性较轻;冻后72小时,神经溃变及修复并存,无髓神经较有髓神经易于修复。  相似文献   
12.
Summary A two-cell human embryo recovered from the Fallopian tube 82 h following the LH peak in plasma and 37 h after a single episode of intercourse was examined by transmission electron microscopy. At the time of recovery the embryo was denuded of cumulus cells, and both the zona pellucida and the two adjoining blastomeres were intact. The finding of two polar bodies in the perivitelline space, two nucleated blastomeres and remnants of the fertilizing sperm tail within the cytoplasm of one of them, were considered as evidences that the embryo was normally fertilized. Among the most compicuous features found were the presence of very distinct desmosome-like structure between blastomeres, and the cytoplasmic cell organelles distribution in three areas referred as: a sub-cortical, a middle and a perinuclear bands. An outstanding feature was the extensive blebbing of the nuclear envelope. In general, the features seem to correspond to a normally developing two-cell embryo undergoing cleavage at a normal rate.  相似文献   
13.
本文报道了6例地中海贫血红细胞系列的超微结构改变,包括中、晚幼红细胞,网织红细胞及部份成熟红细胞的胞浆及胞核内可见电子密度较高的包涵体(α或β肽链的沉积);核膜有缺失或重叠,核周间隙扩大;各期红细胞中易见自噬泡和空泡形成;红细胞外形变化显著,发现有特征性的棒形红细胞。此外,还观察到红细胞在狭窄的脾窦中被扣押、挤压、破坏的现象。上述变化提供了地中海贫血发病机理的形态学证据  相似文献   
14.
The intracellular structure of endothelium lining vein-to-artery grafts in rats was analysed, using transmission electron microscopy and morphometry, to determine the ultrastructural adaptations of endothelial cells in this altered vascular environment. Autogenous 4-mm sections of iliolumbar veins were inserted microsurgically into the left common iliac arteries of 16 male Wistar rats. At 3, 6, 26 and 52 weeks the cytoplasmic-vesicular, mitochondrial and rough endoplasmic reticular contents of endothelial cells lining the grafts, the opposite iliac arteries and the remaining ilio-lumbar veins were analysed morphometrically. There was a significant increase in the amount of all these cytoplasmic structures in endothelial cells at 3, 6 and 26 weeks; at 52 weeks there was also a significant increase in the volumes of mitochondria and cytoplasmic vesicles, but not in rough endoplasmic reticulum. It was concluded that the ultrastructure of endothelial cells lining these grafts is changed chronically after graft insertion, and we propose that this may be attributable to altered haemodynamic stresses within the graft.  相似文献   
15.
Although the esophagus is the most frequent site ofCandida infections in the gastrointestinal tract, and many clinical studies about it have been reported, little attention has been directed toward experimental candidiasis of the esophagus, especially with regard to its ultrastructure. Using transmission electron microscopy, this study was performed to clarify the ultrastructure of experimental lesions, obtained from five New Zealand white male rabbits which were given a suspension ofCandida albicans cells (107/ml) for 13 days. The results showed that the lesions consisted of exfoliating, squamous epithelial cells with mycelial elements ofCandida albicans cells penetrating through them, and that a widened intercellular space between individual cells in the area of candidial invasion seems to be a characteristic finding of candidial infection. A part of this study was presented at the 25th Annual Meeting of the Clinical Electron Microscopy Society of Japan, Matsumoto, September 28–30, 1993.  相似文献   
16.
Summary Ultrastructural studies of cells and tissues in the acquired immunodeficiency syndrome (AIDS) have revealed two distinct cytomembranous inclusions referred to as tubuloreticular inclusions (TRI) and confronting cylindrical cisterns (CCC). TRI are found most often in leukocytes and endothelial cells in conditions with elevated levels of alpha-interferon, such as viral infections, autoimmune diseases and certain neoplasms. On the other hand, CCC are detected almost exclusively in mononuclear inflammatory cells and are limited to a few conditions, of which AIDS is the most common. CCC have been proposed as an ultrastructural marker for human immunodeficiency virus (HIV) infection. We describe CCC in mononuclear inflammatory cells in the brain of a patient with AIDS. Finding CCC in brain tissue with no other specific feature such as multinucleated giant cells, nevertheless, should alert the neuropathologist to the possibility that the patient might have AIDS.  相似文献   
17.
Summary Unusual inclusions with some of the features of reducing bodies were encountered in the skeletal muscle biopsy of a 2.5-year-old boy with childhoodonset acid maltase deficiency. The biopsy revealed a vacuolar myopathy with lysosomal storage of glycogen and eosinophilic refractile inclusions in myofibers, which appeared dark blue with the menadione-nitroblue tetrazolium reaction. The significance of the association of inclusions with reducing properties in the setting of acid maltase deficiency is discussed.  相似文献   
18.
本文介绍一种具有较高性能价格比的生物医学电镜图像处理系统,该系统以IBM PC/XT,AT或386计算机为主机,图像接口板直接插入机内扩展槽。应用软件可对生物医学图像作图像处理和定量计算。作者通过对人膈腹膜超微结构进行定量分析,为腹水的治疗和腹膜透析(CAPD)等临床医学研究,提供了形态学定量资料。  相似文献   
19.
The purpose of this investigation was to test the hypothesis that activation of the immune system in rats will lead to changes in the density of innervation in lymph nodes. In order to reduce the variability between animals, the rats were reared under sterile conditions and immunostimulation was effected by subcutaneous application of bovine albumin in a region draining to the axillary lymph nodes of both sides. Control animals received an equivalent application of sterile physiological saline. The animals were sacrificed 10 days and 27 days and 4 months after immunostimulation. The nerves in the axillary lymph nodes were quantified by light microscopy in silver impregnated sections and at the ultrastructural level on ultrathin sections. The survival times were chosen so that the first group was in the ascending phase of antibody production, the second group at the peak, and the third group in the declining phase. Both at the light and ultrastructural levels, there were statistically significant differences in the density of innervation of medulla between the groups, with a particularly pronounced increase in the group 4 months after immunostimulation. At the ultrastructural level, there was also an increase in the density of incompletely ensheathed axonal profiles in the parenchyma of the medulla, while the nerves associated with blood vessels were not increased. We conclude that immunostimulation leads to morphological changes in the innervation of the medulla of axillary lymph nodes, that are consistent with the concept of functional activation of the autonomic nervous system through the immune system. © 1994 Wiley-Liss, Inc.  相似文献   
20.
慢性低氧大鼠肾上腺皮质球状带的变化   总被引:1,自引:0,他引:1  
瓦龙美 《解剖学报》1998,29(1):90-93,I016
将Wistar大鼠喂养在逐渐降低的常压低氧条件下,用氮气和空气的混合气体调节氧含量。氧浓度由正常逐步降低为15%、12%、10%、8%,最后降至7%,实验共进行112d,结果显示低氧动物体重下降,肾上腺重量减少,肾上腺皮质球状带萎缩,脂质丢失,球状带细胞线粒体肿胀和空泡变性,溶酶体增多,表明在慢性常压低氧中,当吸入气氧含量降至7%时,可导致肾上腺皮质球状带细胞超微结构改变,从而影响醛固酮的合成与分  相似文献   
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