A stereological study of the human ovarian surface epithelium.

The surface of the ovary has been found to be composed of two types of epithelial cells called A and B cells which are found in their own respective zones, the A and B zones. A quantitative study was undertaken to determine the mean cell volumes and cell ultrastructure. Ovarian biopsies were taken from six women and A and B zones, having been identified by scanning electron microscopy, were re-embedded for transmission electron microscopy. Stereological measurements using point sampled intercepts were made on vertical sections and showed that B cells are significantly larger than A cells. The volume weighted mean cell volumes of the A and B cells were 237.3 microns 3 and 676.8 microns 3 respectively. The volume fractions of the nucleus and mitochondria were similar in the two cell types. Although the vesicle content of each type was similar, a large variation between cases made the interpretation difficult. The stereological tools used in this study proved to be easy and efficient estimators of surface cell ultrastructure and give an important direction for ultrastructural research.     

大白鼠肾上腺的血管构筑

本实验采用血管铸型扫描电镜,注射明胶卡红组织切片显微镜下观察和注射铅丹乳胶追踪血管来源三种方法对14只健康大白鼠肾上腺血管构筑进行了研究。大白鼠肾上腺动脉发自腹主动脉和肾动脉。它们在行程中发出分支至腺体表面,再次分支穿入囊内,逐级分支至毛细血管。皮质动脉发自囊内血管,它们在皮质中分支分布。球状带的毛细血管与囊的毛细血管相连,毛细血管在球状带围绕细胞团形成网眼状;在束状带呈放射状排列;在网状带吻合增多形成网状。髓质动脉亦发自囊的血管,它们在皮质中不发分支直抵髓质,在髓质分成毛细血管。网状带的毛细血管越向髓质口径越粗,它们在皮髓交界处互相吻合形成更粗的静脉,这些静脉逐级吻合,最后形成一主干——中央静脉,它穿出皮质出现于肾上腺门处。左侧的中央静脉注入在肾静脉,右侧的注入下腔静脉。     

枸杞多糖对运动性骨骼肌疲劳恢复的细胞定量化学分析和电镜观察

通过小鼠实验，用枸杞多糖解除运动性骨骼肌疲劳，以显微分光光度计进行琥珀酸脱氢酶(SDH)和糖原的定性定量分析，并于透射电镜下观察超微结构的变化。结果显示，运动疲劳(B)组糖原含量明显降低，各类肌纤维与对照(A)组比较P<0．001。SDH活性增加，各类肌纤维与A组比较P<0．001。服用枸杞多糖(C)组糖原含量增加，各类肌纤维与A组之较P<0．001；与B组比较P<0．001；SDH反应较B组更深，各类肌纤维与A组比较P<0．001，若与B组比较，则其中Ⅰ(慢肌)型和Ⅱ(中间肌)型P<0．001，而Ⅱ(快肌)型则P>0．05。超微结构显示，B组线粒体增多且体积明显增大，呈肿胀状态，C组全无此类改变，提示服用枸杞多糖后可解除疲劳，其中以Ⅰ(慢肌)型肌纤维效果尤佳。     

Experimental study of spinal cord compression by epidural tumors using electron probe X-ray microanalysis and confocal laser scanning microscopy

Changes in the nerve fibers of the spinal cord were studied in rat experimental epidural tumor models. Light microscopy showed demyelinization in all with rats paraparesis and paraplegia. Cross-sectional views of nerve fibers stained with 3,3dipentyloxacarbo-cyanine iodide, obtained by confocal laser scanning microscopy, showed distorted, shrunken fibers with a low fluorescence intensity. Changes in the electrolyte contents of nerve fibers were studied by electron probe X-ray microanalysis. The K concentration in axons and the myelin sheath was increased in the paraparesis group, but was decreased in the paraplegia group. These findings suggest that, in the paraparesis group, compression of the spinal cord damaged cell membrane channels, which subsequently caused an increase in intracellular K, a decline in the action potential, and low-intensity fluorescence of nerve fibers. On the other hand, in the paraplegia group, destruction of cell membranes caused a decrease in intracellular K until it approached the extracellular level. This reduced both the action potential and the fluorescence intensity. As Ca and Mg concentrations in both axons and the myelin sheath increased in relation to the severity of neurologic damage, it appears that these electrolytes may also play an important role in damage to nerve fibers.     

Pseudoangiosarcomatous carcinoma: a clinicopathological study of seven cases

Seven cases of carcinoma mimicking angiosarcoma occurring in skin (3 cases), breast (3) and lung (1) are described. The cutaneous, pulmonary and one of the breast carcinomas were poorly differentiated and squamous in type; the other two breast tumours were poorly differentiated ductal carcinomas with focal squamous differentiation. Histologically, the pseudoangiosarcomatous pattern was due to complex anastomosing channels and spaces lined by neoplastic cells. The spaces contained hyaluronic acid. The neoplastic cells exhibited cytokeratin positivity but yielded negative results with the endothelial cell markers, factor VIII-related antigen and CD 34 (QB-END/10). Two breast tumours showed binding of UEA-1. Ultrastructurally, unequivocal epithelial differentiation was demonstrated in six of the cases. Pathogenetically, these tumours appeared to be variants of acantholytic squamous cell carcinoma. Recognition of this unusual form of carcinoma is important, as an incorrect diagnosis of angiosarcoma may lead to inappropriate treatment and prognostication.     

NMR Microscopy of Single Neurons Using Spin Echo and Line Narrowed 2DFT Imaging

NMR microimages of single neural cells were acquired at 500 MHz using a conventional spin echo pulse sequence and a line-narrowing sequence that eliminates susceptibility effects. The data show that any contribution to the measured T₂ relaxation rate arising from diffusion in local field inhomogeneities using spin echo sequences at high fields and high spatial resolution is relatively small. We conclude that the measured T₂ difference between the nucleus and cytoplasm in these cells represents primarily a true T₂ relaxation effect arising from the interactions of water with macromolecules in the two compartments and does not result from microsusceptibility differences. These observations have implications regarding water compartmentation in single cells and the interpretation of the MR characteristics of tissues in vivo.     

Experimental model of chronic tonsillar herniation associated with early stage syringomyelia

This report describes an experimental model of chronic tonsillar herniation and its effects on the spinal cord. In ten rats, a small piece of chemically induced mammary cancer was transplanted to the supraoccipital bone. In all cases, the transplanted cancers grew into the posterior fossa, destroying the supraoccipital bone and compressing the cerebellum extradurally. In six of the ten rats, tonsillar herniation was observed at 8–14 weeks after transplantation. Transdural infiltration of the tumor cells was not apparent in any animal. In those rats with tonsillar herniation (n=6), the spinal cord from the C5 to the T8 segments showed enlargement of the central canal without exception. Histological examination revealed the following changes: stretching and thinning of the ependymal cells; swelling of the astrocytic processes; and extracellular edema, predominantly in the dorsal gray matter, but also in the ventral inner portion of the dorsal column. In the control group (n=4) and those rats without tonsillar herniation (n=4), such histological changes of the spinal cord were not observed. Although the lesions can not be regarded as representing mature syringomyelia, they most likely constitute an earlier evolutionary stage.     

高功率微波辐照后大鼠肝组织的形态学改变

目的 探讨高功率微波(high power microwave，HPM)辐照后对大鼠肝组织形态结构的影响。方法雄性SD大鼠36只，随机分为两组，实验组(24只)和正常对照组(12只)，在微波辐照后6、24和48h及7d活杀大鼠，取肝脏组织；30mg／L戊二醛固定，进行常规扫描电镜标本制备；甲醛固定制备光镜标本。结果对照组肝细胞形态正常，肝板排列整齐。辐照后6h，肝细胞轻度肿胀。辐照后24h，肝细胞肿胀，肝板排列紊乱，肝窦狭窄。辐照后48h，肝细胞变性更明显，肝板排列严重紊乱，肝细胞空泡化明显，肝窦内广泛淤血。辐照后7d，肝细胞仍然肿胀，空泡化现象主要在中央静脉周围，肝窦内淤血有所减轻。结论高功率微波辐照对肝组织的损伤主要是发生肝细胞肿胀和肝窦淤血；这可能与辐照的致热效应，以及电场、电离作用等有关。     

角膜移植术后角膜在共焦显微镜下的形态学改变

目的：研究角膜移植术后角膜组织在共焦显微镜(Confocal microscopy)下的形态学改变。方法：应用Conoscan2．0共焦显微镜对板层角膜移植术后3～7d患者12例(12只眼)，术后1a患者8例(8只眼)，穿透性角膜移植术后3～7d患者10例(10只眼)，术后1a患者11例(11只眼)进行扫描检查，记录各层角膜图像。结果：板层角膜移植术后3～7d，植片中基质细胞较小，可见裂隙状暗纹和细小神经，层间为大面积高反光区，有点状颗粒沉积，植床水肿，细胞成像不清。移植术后1a，植片中未见神经，层间反光明显减弱，但仍有点状高反光颗粒沉积，植床中出现粗大裂隙状暗纹，内皮细胞密度正常。穿透角膜移植术后3～7d，植片中基质细胞“激活”，可见神经和后基质层的粗大暗纹，内皮细胞密度正常，细胞间可镶嵌有高反光点。术后1a，植片中基质细胞仍较小，未见神经，后基质层仍有裂隙状暗纹，内皮细胞体积增大，密度减少，高反光点消失。结论：Confoscan 2．0共焦显微镜可活体检查角膜移植术后角膜组织结构和细胞的病理改变，这对评估手术效果和临床观察以及跟踪随访具有重大意义。     

The Cutaneous Microcirculation: Ultrastructure and Microanatomical Organization

The cutaneous microcirculation is organized as two horizontal plexuses. One is situated 1–1.5 mm below the skin surface, and the other is at the dermal-subcutaneous junction. Ascending arterioles and descending venules are paired as they connect the two plexuses. From the upper layer, arterial capillaries arise to form the dermal papillary loops that represent the nutritive component of the skin circulation. There are sphincter-like smooth muscle cells at the point where the ascending arterioles divide to form the arteriolar component of the upper horizontal plexus. At the dermal subcutaneous junction, there are collecting veins with 2-cusped valves that are oriented to prevent the retrograde flow of blood. Laser Doppler flowmetry (LDF) has demonstrated vasomotion of red cell flux localized to the sites of ascending arterioles. The simultaneous recording by LDF of red cell flux and the concentration of moving red blood cells from individual sites allows one to construct by computer topographic maps of these two valves. The two maps, based on initial studies using correlative skin biopsy specimens, can define 1-mm³ volumes of skin that are predominantly arteriolar in composition, predominantly venular in composition, or essentially devoid of all microvascular elements. The electron and light microscopic features that define the microvascular segments, when coupled with the ability of LDF to define the predominant microvascular segments under the probe, will allow one to study both the mechanisms of normal physiological states and the pathogenetic mechanisms underlying pathological skin disorders in which the microvasculature plays a predominant role.