镉中毒小鼠肝细胞的立体学定量研究

本文用立体学定量的方法,分析镉中毒小鼠肝细胞核、线粒体、脂滴的变化,确定肝细胞核及线粒体的平均体积、表面积显著缩小;脂滴的平均体积及表面积明显增大,与正常对照组有高度显著性差异(P<0.01)。细胞形态的计量研究越来越多地应用于形态学科领域,本文用立体学的方法定量研究镉中毒小鼠的肝细胞。     

镉中毒小鼠肝细胞的立体学定量研究

本文用立体学定量的方法,分析镉中毒小毒肝细胞核、线粒体、脂滴的变化,确定肝细胞核及线粒体的平均体积、表面积显著缩小;脂滴的平均体积及表面积明显增大,与正常对照组有高度显著性差异(P<0.01)     

无蹼壁虎冬眠期与出眠初期肝脏比较细胞学研究

用形态计量学方法对无蹼壁虎冬眠期与出眠初期肝脏进行了比较细胞学研究，结果表明：１．冬眠期肝细胞内富含糖原颗粒和脂滴，线粒体和粗面内质网稀少，溶酶体较小且电子密度较低，高尔基复合体极少。出眠初期肝细胞内糖原颗粒和脂滴稀少，线粒体和粗面内质网丰富，溶酶体较大且电子密度较高，高尔基复合体增多。２．出眠初期肝脏有明细胞和暗细胞区分。３．冬眠期肝血窦内肝细胞表面的微绒毛数目明显少于出眠初期。４．冬眠期与出眠初期胆小管内肝细胞表面微绒毛数目之间差异不显著，但冬眠期肝小管细胞内富含糖原颗粒，出眠初期肝小管细胞内富含粗面内质网。上述结果提示：１．冬眠期肝细胞处于不活跃状态，出眠初期大部分肝细胞处于活跃状态。２．出眠初期肝细胞内溶酶体功能较冬眠期活跃，细胞内消化能力明显增强。３．出眠初期肝细胞与血液之间的交换能力较冬眠期强。４．肝细胞中的脂滴是冬眠中脂肪储备的一种重要形式，其在维持冬眠期物质与能量消耗方面有重要意义。     

大鼠烫伤后早期肝细胞变化的超微结构观察及形态计量分析

用超微结构形态计量方法分析了大鼠30％烫伤后早期肝细胞超微结构的变化规律。烫伤后,肝细胞内精原迅速减少,至6小时,几乎全部消失。烫伤后2小时、6小时。肝细胞内溶酶体的体积密度、数目密度和平均体积均明显增大。线粒体于烫伤后半小时出现基质密度增加、嵴扩张,烫伤后2小时、6小时,线粒体肿胀,其体积密度、平均体积增大。实验结果提示:在严重烧伤后数小时内,肝细胞的超微结构即出现明显的改变。本文对出现这些变化的机制进行了讨论。     

高脂血症大鼠血液流变学及肝脏微循环的改变

目的 探讨高脂血症大鼠血液流变学及肝脏微循环的改变。方法 Wistar大鼠随机分为（1）正常组：喂普通饲料；（2）高脂血症组：喂高脂饲料4周，每组6只。于造模4周后测定血清血脂水平、体质量及肝质量与体质量之比、血液流变学和肝脏活体微循环的改变。结果 喂高脂饲料4周后肝脏体积增大，体质量及肝质量明显高于正常对照组（P〈0．01）。肝组织标本显示肝细胞肿胀、脂肪性变，肝细胞的胞浆内充满大小不等的脂滴。血清胆固醇、低密度脂蛋白较正常对照组明显增高（P〈0．01），高密度脂蛋白减少，甘油三脂变化不大；血压及血浆黏度较正常组增高明显（P〈0．05）；肝脏活体微循环观察显示肝脏微血管数明显减少，肝细胞索增大，泡沫状突起压迫周围血管，血流速度减慢，血管内有红细胞聚集和白细胞黏附。结论 短期内高脂食物的摄入可造成脂质代谢紊乱，继而发生血液流变学及肝脏微循环障碍。     

银杏叶提取物减轻臂丛根性撕脱后脊髓运动神经元超微结构的损伤

目的：研究银杏叶提取物(EGb761)对臂丛撕脱后运动神经元超微结构的保护作用。方法：显微镜下撕脱大鼠臂丛 C_5～T_(?)神经根,术后实验大鼠腹腔注射100 mg·kg~(-1)·d~(-1)EGb761,透射电镜观察损伤 C_7节段运动神经元的超微结构。结果：神经根撕脱6～8周,运动神经元胞体体积缩小、胞核染色质裂解、浓缩异染色质增多;粗面内质网和游离核糖体减少、线粒体减少、嵴肿胀;神经髓鞘不完整、呈空泡状变性。EGb761治疗后,胞体体积基本正常,偶见浓缩异染色质;粗面内质网减少不显著;游离核糖体数量明显增多;线粒体形态正常;髓鞘完整呈同心圆包绕在轴索周围。结论：EGb761能减轻运动神经元超微结构的损伤,减少臂丛根性撕脱诱导的运动神经元凋亡。     

大鼠肝大部切除后肝细胞超微结构的变化

切除人鼠肝左叶与中叶(68%),电镜观察术后3～120小时的肝细胞。术后20小时内肝细胞超微结构发生进行性衰退,脂滴递增,细胞器退化,而溶酶体和自噬体显著增多,胞质内的退化结构和自噬体从细胞血窦面脱落入血窦内,被巨噬细胞吞噬,此乃肝细胞在DNA复制和分裂高峰前迅速进行结构更新的表现。术后20～48小时,肝细胞处于复制和增殖高峰,也是肝细胞结构逐渐恢复的时期,脂滴减少,游离核糖体先增多,表明此时细胞以合成结构蛋白为主;继而RER等增多。术后48小时以后,肝细胞结构基本恢复正常,RER和高尔基复合体发达,提示细胞功能基本复原。肝大部切除后肝细胞超微结构变化迅烈,恢复也甚快,讨论了这些变化在肝再生中的意义。     

体外反搏后心肌梗死犬心肌形态学的观察

目的：探讨体外反搏对心肌梗死犬超微结构的影响。方法：19只健康杂种犬随机分为对照组、梗死组和反搏组3组，采用透射电镜观察梗死区心肌组织的超微结构变化，并通过图像分析系统对线粒体进行形态定量分析。结果：形态学观察发现反搏组犬心肌肌小节、肌丝、线粒体和血管内皮细胞损伤比梗死组明显减轻。定量分析发现反搏组犬心肌线粒体数密度和比表面均明显高于梗死组，而线粒体体积和平均表面积均小于梗死组（P〈0．05）。结论：体外反搏可减轻心肌梗死犬的心肌超微结构损伤。     

吗啡处理大鼠海马线粒体定量分析及超微结构观察

目的通过对慢性吗啡处理大鼠海马CA1、CA3区神经元线粒体的定量分析及超微结构观察,为阿片类药物依赖的神经元可塑性改变补充理论资料。方法剂量递增法建立大鼠吗啡依赖模型。取海马CA1、CA3区组织进行透射电镜观察和线粒体体视学定量分析。结果海马CA1、CA3区模型组线粒体体积密度(Vv)、数密度(Nv)、表面积密度(sv)均较对照组增大(分别为P<0.05,P<0.01,P<0.01),比表面积(δ)减小(P<0.01)。超微结构观察:对照组线粒体结构正常;模型组线粒体数量增多,基质电子密度增高,肿胀、可见嵴断裂及空泡变。结论吗啡慢性处理造成了神经元线粒体形态结构的代偿性适应改变,从而影响整个神经元的结构和功能可塑性。     

四氯化碳引起肝硬化过程中肝组织的细胞学和组织化学变化

大白鼠肝在CCl_4中毒所引起肝硬化过程中,肝小叶结构被破坏。肝细胞中毒,坏死,脂肪游离增多。血窦因血流受阻而涨大。大部分肝细胞退变或坏死;部分残存而代偿性增生。结缔组织在坏变部分增生并包围肝小结而形成肝硬化。在肝硬化过程中,退变的肝细胞内脂滴增多。线粒体减少,成粒状或溶成一团。核糖核酸,糖元含量也随病变进展而减少。碱性磷酸酶反应增强。代偿性增生的肝细胞体积增大;肝细胞内线粒体增多,核糖核酸,糖元含量逐渐增多。在病变过程中出现冼多小型细胞。小型细胞出现在坏变的肝细胞区域,脂肪空泡附近及结缔组织内并随纤维的增加而减少。小型细胞含线粒体,核糖核酸,PAS反应及碱性磷酸酶反应均为阳性。文中讨论了肝细胞内细胞学和组织化学变化的意义;小型细胞的来源,与纤维形成的关系及纤维增生机制等问题。     

慢性镉中毒小鼠生精上皮的超微结构观察和立体定量分析

本用透射电镜观察并结合立体定量法研究了慢性镉中毒时小鼠睾丸生精上皮的超微结构。结果为：（1）支持细胞明显受损，细胞核增大，细胞器出现变性变化，有的支持细胞呈现坏死现象，（2）各级生精细胞有不同程度损伤，生精小管管腔内常见未成熟精子和畸形精子。（3）支持细胞的细胞连接被破坏，血－生精小管屏障部分瓦解，本还对慢性镉中毒时影响精子发生的机理进行了初步探讨，认为支持及其细胞连接的结构和功能异常可能是生精障碍的主要原因。     

Ultrastructural, immunohistochemical and biochemical investigations of the rat liver exposed to experimental diabetes und acute hypoxia with and without application of Ginkgo extract.

The aim of this paper was to investigate the effect of streptozotocin-induced diabetes by i.p. bolus injection of streptozotocin at 60 mg per kg bodyweight over four months and additional acute respiratory hypoxia (20 min. duration, 5% oxygen v/v), and also the protective effect of Ginkgo biloba extract (EGb 761) on Wistar rat liver under these experimental conditions. Diabetic and additional hypoxic alterations in histology and ultrastructure were subjected to qualitative and quantitative analysis, collagen was investigated by immunohistochemistry, and some biochemical parameters of oxidative stress were determined. Diabetes caused an increase in the size of the hepatocytes and their nuclei with a decrease in nucleus-to-plasma ratio and glycogen content. Connective tissue was variably increased in individual cases as shown by routine histological staining. EGb did not influence these data. Ultrastructural morphometry revealed a significant reduction in rough endoplasmic reticulum (rER) and a significant increase in smooth endoplasmic reticulum (sER) through diabetes, an increase under EGb protection, with no significant alteration under hypoxia. The volume fraction of mitochondria was significantly increased after induction of diabetes but less increased in the protected group. Additional hypoxia reduced this parameter. The mean cross-section area of mitochondria was significantly elevated in all diabetic groups compared to controls. Volume density of mitochondrial cristae was significantly diminished in all diabetic groups; EGb could only improve this parameter in the diabetic-hypoxic group.     

Cadmium toxicity in perinatal rat hepatocytes: electron microscopy, X-ray microanalysis, and morphometric analysis

Effects of cadmium on the fetal and postnatal rat hepatocytes were studied with an electron microscope and an X-ray microanalyzer. Pregnant and lactating Wistar rat dams at 15 and 21 days of pregnancy and at 3 days after delivery received intraperitoneal injections of cadmium sulfate (1 mg/kg body weight) for 3 days. On the day following the last injection, the livers were isolated from the fetal and suckling rats and provided for electron microscopy. The livers from the untreated fetal and newborn rats served as control. Large bile canaliculi, which were formed by five or more hepatocytes, were frequently observed in the cadmium-treated perinatal rat livers. The intercellular space between each adjacent hepatocyte was widened. By X-ray microanalysis, cadmium peaks were preferentially detected out from intramitochondrial granules of the cadmium-treated hepatocytes. By morphometric analysis, the increase both in the mitochondria volume and in the number of intramitochondrial granules was evident in the cadmium-treated hepatocytes when compared to those of control. These data suggest the preferential accumulation of cadmium in mitochondria of the hepatocytes interferes with the morphogenesis of the perinatal rat liver.     

Morphological and functional responses of rat Leydig cells to a prolonged treatment with human chorionic gonadotropins

The morphological and functional responses of rat Leydig cells to a 3- and 6-day treatment with human chorionic gonadotropins (hCG) (10 IU/kg/day) were investigated by morphometric and radioimmunological techniques. hCG-administration induced a notable time-dependent enhancement in the steroidogenic capacity and growth of Leydig cells; this last was almost exclusively due to hypertrophy (and not to hyperplasia). The volume of mitochondrial and peroxisome compartments, as well as the surface area per cell of mitochondrial cristae and smooth endoplasmic reticulum (SER) were significantly increased after hCG treatment, and showed a highly significant positive linear correlation with both basal and stimulated testosterone production by isolated Leydig cells of the contralateral testis. Also the volume of nuclei and lipid-droplet compartment and the surface area per cell of Golgi apparatus displayed a notable hCG-induced rise, but they did not correlate with testosterone secretion. These findings suggest that, in addition to mitochondria and SER, in which the enzymes of steroid synthesis are located, peroxisomes are also specifically involved in the secretory activity of rat Leydig cells.     

Development of morphologic heterogeneity of hepatocyte mitochondria in the mouse

The ultrastructure of mitochondria in periportal and perihepatic hepatocytes from newborn, 5-, 10-, and 20-day-old, and adult male ddY mice was analyzed by quantitative electron microscopy. In newborn and 5- and 10-day-old animals, the axial ratio (length per diameter), surface to volume ratio (area of the outer membrane per unit mitochondrial volume), and volume density were not significantly different between periportal and perihepatic cells. In 20-day-old and adult animals, the surface to volume ratio was greater in perihepatic cells than periportal cells, and the volume density was greater in periportal cells than perihepatic cells. The axial ratio became greater in perihepatic cells than periportal cells in adult animals. However, there were no differences in the surface density of the outer membrane, and of the inner membrane and cristae between the cells of both zones in all age groups examined. When the data were expressed as volume and area per cell, the patterns of subacinar distribution and age-related changes differed from the patterns seen in the volume and surface density data mainly in adult animals. This difference was generally caused by the marked increase in hepatocyte volume between 20 days of age and adulthood, especially in perihepatic cells. The results show that differences between mitochondria in periportal cells and those in perihepatic cells in the shape (the axial and surface to volume ratios), volume density, and area of the outer membrane per cell, evident in adult animals, are not present in newborn animals but arise during postnatal development.     

The surface area of sheep cardiac Purkinje fibres

1. Measurements combining the techniques of point counting and line integration were performed on light and electron micrographs of Purkinje fibres from the sheep's heart. The measurements were aimed at determining membrane areas of importance for the cellular electrophysiology of this tissue.2. The mean volume fractions of the cells occupied by various constituents were: myofibrils, 0.234; mitochondria, 0.103; and nuclei, 0.009. The mean volume fraction of the fibres occupied by the interspaces between the tightly packed cells was 0.0023.3. The mean fractions of intercellular surface area occupied by junctional specializations were: nexus, 0.17; desmosome, 0.023; and fascia adherens, 0.014.4. The mean surface to volume ratio of the Purkinje cells and fibres was 0.46 mu(-1) which is 11.5 times the value of the surface to volume ratio of a long right circular cylinder 100 mu in diameter.5. There are two reasons for the increment in the surface to volume ratio of the fibre (when compared to that of a long right circular cylinder 100 mu in diameter): the multicellular composition of the fibres and the extensive folding of the surface of the cells.6. After correction for the intercellular nexal area the surface to volume ratio of a long cylindrical fibre 100 mu in diameter was 0.39 mu(-1), or about 10 times the value for a long right circular cylinder 100 mu in diameter. The surface to volume ratio of the tissue interspaces in the same fibre was 170 mu(-1).7. It was concluded that the total sarcolemmal area in this tissue is great enough so that the specific membrane capacitance could be about 1 muF/cm(2) and the specific membrane resistance 20,000 Omega cm(2).     

So-called empty liver cell nuclei in hepato-cerebral dystrophy and other diseases]

The frequency of identification of "empty" nuclei of hepatocytes was investigated in 65 patients (25 patients with hepato-cerebral dystrophy, 18 patients with cirrhosis of the liver, 15 patients with chronic diseases of the extrapyramidal nervous system and other diseases) with the help of fluorescent and electron microscopy, cytophotometric determination of DNA, and on the basks of bioptic material (in 60 patients) and autopsy findings (in 5 cases). The so-called "empty" nuclei of hepatocytes are not specific for hepato-cerebral dystrophy, although in this disease they were observed in a greater number than in other diseases. Their dependence on the degree of portal hypertension and on some endocrine factors was noted. "Empty" nuclei were identified most often in the periportal regions and were characterized by a considerable increase in the volume, invaginations of the membrane, intranuclear inclusions, polyploidy. The study of polyploidy of the ordinary nuclei of hepatocytes in hepatocytes in hepato-cerebral dystrophy, bearing in mind the reduplicated DNA, revealed the predominance of diploid nuclei.     

Number and ultrastructure of epithelial cells in crypts and villi along the streptozotocin-diabetic small intestine: a quantitative study on the effects of insulin and aldose reductase inhibition

This study has quantified the effects of insulin treatment with and without aldose reductase inhibitor (ponalrestat) on intestinal epithelial cell morphology in streptozotocin-diabetic rats. Epithelial volumes, villous and microvillous surface areas and mean volumes of cells (and their nuclei) in crypts and villi were estimated in each of four segments and in the entire intestine. We derived total numbers of cells, quantified the ultrastructural features of average cells and explored variation along the intestine and between experimental groups. In crypts, insulin and ponalrestat had significant effects on cell number (reduced towards normal values) and size (volume and apex area increased beyond normal values). There were interaction effects between insulin and ponalrestat for cell volume and apex area (insulin producing more exaggerated effects when given without ponalrestat). On villi, insulin and ponalrestat returned cell numbers towards normal values but neither treatment normalised cell size or the number and area of microvilli per cell. Indeed, ponalrestat increased microvillous number and area beyond values found in untreated diabetic animals. Again, there were interaction effects between insulin and ponalrestat. Patterns of segmental variation seen in crypts of normal rats (values tending to be higher in proximal or mid-intestinal regions) were not preserved, and only some of the segmental differences seen on villi (higher values at proximal or mid-intestinal sites) were maintained during therapy. Apart from reducing the abnormally high numbers of cells in untreated diabetic rats, these results show that insulin and ponalrestat treatment fail to restitute epithelial cell morphology in the small intestines of experimental diabetic rats.