人乳头瘤病毒感染超微结构观察

本文对5例典型尖锐湿疣标本及10例可疑人乳头瘤病毒感染标本进行透射电子显微镜观察。结果典型尖锐湿疣标本中仅1例于细胞核内见到人乳头瘤病毒,排列规则呈结晶状。其余14例标本的细胞内均见不同程度的由病毒感染所引起的非特异性病理变化。本文对人孔头瘤病毒及受感染细胞的超微结构进行了初步探讨。     

Ultrastructural distribution of NADPH-diaphorase in the normal hippocampus and after long-term potentiation

Summary The distribution of the enzyme nitric oxide synthase (NOS) was investigated at the ultrastructural level in synaptic structures of the hippocampal formation in relation to long-term potentiation (LTP), based on the histochemical NADPH-diaphorase (NADPH-d) staining with the tetrazolium salt BSPT. BSPT-formazan, the osmiophilic reaction product, was found to be selectively distributed and predominantly attached to membranes of the endoplasmic reticulum. In synaptic regions mainly the presynaptic sides showed labeling. Although several groups have demonstrated a principal involvement of NO in the LTP-mechanism, we found only a low, statistically insignificant increase in NADPH-d stained presynaptic areas of the dentate gyrus, where LTP was evoked. Postsynaptic elements also did not show any noticeable differences. Based on the present results, the predominantly presynaptic localization of NOS should be preferably considered in models describing a functional role of NO in LTP formation, despite the fact that we failed to reveal any indications for an LTP-related change in synaptically located NADPH-d.     

ONCOCYTES OF THE THYROID: A NEUTRAL RED DYE UPTAKE STUDY

Oncocytosis and oncocytomas have attracted attention because on the one hand there have been reports of the favourable prognosis and generally benign nature of oncocytic tumours, while on the other hand, Hurthle cell change in thyroid neoplasms have been reported to be correlated with aggressive biological behaviour and a significantly worse clinical course. Presently, there appear to be two schools of thought on the significance of oncocytosis: (i) a process where there is redifferentiation of cells with involvement in the pathogenesis of cancer; and (ii) a compensatory process for ‘functional exhaustion’ of the cell. Many aspects of oncocytosis seem unclear. In this study, transmission electron microscopy is used to demonstrate the presence of thyroid oncocytes in the hemithyroidectomy specimen of a patient with focal lymphocytic thyroiditis. Tissue sections from this specimen did not display preferential uptake of neutral red dye, a distinctive characteristic of M-phase cancer cells which was previously reported. The findings seem to suggest that oncocytes are not cells with distinctive proliferative potentials. If that were the case, then oncogenesis or cancer cell progression and oncocytosis may not be convergent processes.     

Morphologic characterization of osteoblast-like cell cultures isolated from newborn rat calvaria

Summary Two methods for harvesting osteoblast-like cell populations from newborn (10 days) rat calvaria were compared. The first one consisted in culturing the periosteum-free bones and then trypsinizing the cells on the bone surface. The second one involved the migration of the osteoblasts on glass fragments before trypsinization. Since the plating efficiency, the proportion of alkaline phosphatase-positive cells, the population doubling time, and the calcium deposition were more adequate, the second method was used to further characterize the behavior of the cultures. During the first week of culture, the cells featured shapes similar to those observedin vivo on the surface of periosteum-free calvaria. They formed multilayers and, in the presence of ascorbic acid, synthetized an organic matrix containing exclusively type I collagen. Later, small amounts of type III collagen appeared. The cells were embedded in the matrix and progressively acquired the morphologic phenotype of osteocyte-like cells. The matrix mineralized in the presence of β-glycerophosphate. The technique of dropinoculation (high concentration of cells in a small volume of medium) promoted the multilayer formation and the achievement of large mineralized plates (about 1 cm²) in 3 weeks of culture.     

整合素β1在自身免疫性心肌炎小鼠心肌的表达

目的:观察整合素β1在自身免疫性心肌炎小鼠心肌的表达变化。方法:猪肌凝蛋白皮下注射免疫Balb/c小鼠,建立慢性自身免疫性心肌炎模型,于初次免疫后14、30和60d对心肌组织进行病理学检查,同时用激光共聚焦技术和间接免疫荧光法检测整合素β1在心肌的表达变化。结果:在初次免疫后14d,小鼠心脏有局部炎症出现,整合素β1在心脏血管周围的表达高于正常组（P<0.05）;在第30天,小鼠心脏炎性浸润更加明显,整合素β1在心肌的表达增强,显著高于正常组（P<0.05）;第60天,小鼠心脏炎症细胞减少,而纤维化则开始出现,整合素β1在心肌的表达最强（P<0.05）,且排列紊乱。结论:整合素β1在自身免疫性心肌炎的发生及发展过程中起着不同重要作用,整合素β可能参与自身免疫反应及心肌的重构。     

激素对股骨头微血管及组织细胞的影响

目的通过建立激素性股骨头缺血性坏死动物模型,研究股骨头微血管密度(microvas-culardensity,MVD)和股骨头组织细胞超微结构的变化,探讨长期大剂量使用糖皮质激素引起股骨头缺血性坏死的机制。方法健康日本白兔40只,1.86～2.21kg,平均2.06kg。随机分为两组,实验组31只,对照组9只。实验组每周皮下注射醋酸氢化泼尼松8mg/kg,对照组每周皮下注射生理盐水0.32ml/kg。在实验的第4、8和12周分别对实验组和对照组的股骨头行微血管墨汁灌注,研究股骨头MVD的变化;制作半薄切片,在透射电镜下分别观察实验组和对照组的股骨头组织细胞的超微结构。拍摄兔耳背微血管网观察用药前后的变化。结果实验组双侧股骨头松质骨和密质骨的单位面积内MVD与对照组相比在用药3个月后明显下降(P<0.01)。兔耳背微血管网随用药时间的延长逐渐变稀疏。股骨头各系组织细胞内均发现有脂质堆积;骨细胞核膜失去连续性、碎裂,染色质溶解;血管内皮细胞内出现脂滴,胞膜结构不完整,可见明显的裂隙,线粒体肿胀、变圆,结构不清;脂肪细胞异常肥大,核内出现脂滴,并压迫小静脉,管腔变窄;小静脉内可见红细胞相互重叠呈“缗线状”。结论骨内压升高是激素性骨坏死病理过程中的一个表现,与肥大的脂肪细胞压迫小静脉有关。长期大剂量使用糖皮质激素可抑制     

Prevalence of silent myocardial ischemia in asymptomatic individuals with subclinical atherosclerosis detected by electron beam tomography

BACKGROUND: Electron beam tomography coronary calcium imaging is an evolving technique for the early detection of coronary atherosclerosis, and recent studies have established its prognostic value in asymptomatic individuals. The relationship of coronary artery calcium scores (CAC) to obstructive coronary artery disease (CAD) has been poorly studied but is clinically relevant because it determines which individuals are likely to benefit from revascularization procedures. Hence, we prospectively evaluated the prevalence of myocardial ischemia in asymptomatic patients with cardiovascular risk factors and subclinical atherosclerosis. METHODS AND RESULTS: We studied 864 asymptomatic patients with no previous CAD but with cardiovascular risk factors, referred for electron beam tomography coronary calcium imaging to our institution over an 18-month period. From this group, 220 consecutive patients (85% men; mean age, 61 +/- 9 years; age range, 31-84 years) with moderate to severe atherosclerotic disease (coronary calcium score > or =100 Agatston units) were prospectively evaluated by technetium 99m sestamibi single photon emission computed tomography (SPECT). Patients were followed up (mean follow-up, 14 months) and data regarding their subsequent clinical management recorded. Of the 220 patients, 119 had moderate atherosclerosis (CAC score of 100-400 Agatston units) and 101 had severe atherosclerosis (CAC score > or =400 Agatston units). Abnormal SPECT findings were seen in 18% of patients with moderate atherosclerosis (n = 21) and 45% of patients with severe atherosclerosis (n = 45). Increasing severity of atherosclerosis was related to increasing ischemic burden (summed difference score = 1 +/- 0.2 for CAC score of 100-400 Agatston units and 3.2 +/- 0.5 for CAC score > or =400 Agatston units). In a multivariate linear regression model incorporating risk factors, CAC was the only predictor of silent ischemia. CONCLUSION: In comparison to previously published data, we detected a higher prevalence of silent ischemia even in patients with moderate coronary atherosclerosis (18%). This may reflect the differing risk factor profile of our patient population. When coronary calcium screening is used to preselect asymptomatic patients with cardiovascular risk factors for myocardial perfusion imaging, the optimum coronary calcium score threshold will depend on the population prevalence of risk factors and asymptomatic obstructive CAD.     

电镜观察透明质酸酶对人眼晶状体上皮细胞作用

目的：探讨透明质酸酶是否可以溶解晶状体囊膜上皮细胞及其作用机制。方法。取人眼超声乳化白内障摘除术中撕下的前囊膜，对半切开，一半立即置于37℃水浴箱中的2ml平衡液中。另一半置于37℃水浴箱中的2ml平衡液 1500IU透明质酸酶中。分别放置5、1O、15min，然后立即放入4％戊二醛中固定，送透射电镜检查。结果：置于平衡液中5、10、15min的前囊膜，囊膜表面的晶状体上皮细胞之间的细胞连接完整;而置于透明质酸酶中5，10、15min的前囊膜，其表面的晶状体上皮细胞之间以及细胞与囊膜之间的缝隙随时间延长而增大。结论:透明质酸酶可以破坏晶状体上皮细胞之间以及细胞与囊膜之间的连接，从而使晶状体囊膜上的上皮细胞易于被清除。