Eccrine duct carcinoma of the eyelid mimicking meibomian carcinoma: clinicopathological study of a case

Eccrine duct carcinoma belongs to a group of malignant sweat gland tumors showing de novo eccrine differentiation, but without features of benign adnexal counterparts. They are therefore likely to be confused with visceral adenocarcinomas that have metastasized to the lid. These tumors require important diagnostic considerations when adenocarcinoma is encountered in the lid in the absence of a known primary tumor. We present the case of a 60-year-old man with a nodule in the right upper eyelid that was histopathologically diagnosed as eccrine duct carcinoma of the lid. The differential diagnosis of eccrine carcinomas based on light microscopy, enzyme histochemistry, and immunohistochemistry is discussed, and a list of the various malignant eccrine tumors reported in the lid is presented.     

Müller cells express the neuronal progenitor cell marker nestin in both differentiated and undifferentiated human foetal retina

Tritiated thymidine studies suggest that Müller cells are the last cells born in the retina, although several authors describe Müller cells throughout the retina from very early ages. In this study immunohistochemistry was used to identify progenitor and Müller cells in human foetal retina. Antibodies to nestin (an intermediate filament protein expressed by neural progenitor cells), vimentin, cellular retinaldehyde binding protein (CRALBP) and glutamate and aspartate transporter (GLAST), which are each expressed by Müller cells, were used in combination with anti-Ki67 to identify proliferating cells. By definition, Ki67-positive proliferating cells were present in undifferentiated retina, but not in differentiated retina. Nestin-immunoreactive (IR) cells colocalized with vimentin throughout the retina. CRALBP-IR was detected in differentiated retina and in some proliferating cells. GLAST-IR cells were present only within the differentiated region. Nestin, vimentin and CRALBP each colocalized with mitotic Ki67-IR cells, suggesting that in foetal retina Müller cells and retinal progenitor cells are overlapping populations and that Müller cells are end-stage progenitor cells.     

Glucose-6-phosphate dehydrogenase expression associated with NADPH-dependent reactions in cerebellar neurons

This review describes the variation of glucose-6-phosphate dehydrogenase (G6PD) activity in the main neurons of the molecular and granular layers as well as in the deep nuclei of the cerebellum as observed so far by optical and electron microscopy studies. Light microscopy and semiquantitative microphotometry of histochemical staining showed that the highest G6PD activity was expressed by Purkinje cells and neurons of the deep cerebellar nuclei; the elements of the molecular layer showed a diffuse G6PD staining, while the granular layer displayed only scattered G6PD activity. Electron microscopy analysis showed that the basket and stellate cells, as well as the Golgi cells, have a remarkable G6PD activity, while in the granule cells the enzyme was barely detectable. The results show that cerebellar G6PD activity changes with different neuron types as a function of its role in sustaining NADPH dependent pathways in these cells.     

Microglial ecto-Ca(2+)-ATPase activity in a rat model of focal homologous blood clot embolic cerebral ischemia: an enzyme histochemical study

Post-ischemic changes in ecto-Ca(2+)-ATPase activity in microglia and the infarcted tissue were studied in a rat model of focal embolic cerebral ischemia using an enzyme histochemical method. Ecto-Ca(2+)-ATPase activity was observed in whole brains in non-operated and sham-operated control animals. In addition, this enzyme activity was determined to be localized in ramified microglia. At 30 min after ischemia, non-microglial ecto-Ca(2+)-ATPase activity in the infarcted tissue slightly decreased and continued to decrease thereafter. The ecto-Ca(2+)-ATPase activity in microglia did not appear changed at this time. The decrease of enzyme activity in the infarcted tissue made it much easier to clearly observe ecto-Ca(2+)-ATPase-positive microglia. The enzyme activity of microglia in the ischemic area began to decrease 2 or 4h after embolization and remarkably decreased, except in the perinuclear cytoplasm, apical parts of the processes, and several parts along the processes, 8h after ischemia. By 12h after onset of embolization, the enzyme activity of microglia and infarcted tissue had almost completely disappeared. Ecto-Ca(2+)-ATPase of microglia is likely to play an important role in the metabolism of extracellular nucleotides in the ischemic area immediately after the onset of embolization by means of ecto-enzymes. Thus, the findings of the present study suggest that microglia might serve to protect the infarcted tissue in the ischemic brain.     

Lectin affinity of the seminiferous epithelium in healthy and cryptorchid post-pubertal boars

The present study describes the sugar content of the seminiferous epithelium, using lectin histochemistry, in healthy boars and in boars with unilateral and bilateral abdominal cryptorchidism. In healthy boars the apical cytoplasm of Sertoli cells exhibited abundant glucosyl (Con A and WGA lectins), galactosyl (HPA, DBA, SBA and PNA lectins), and fucosyl (AAA lectin) residues. Spermatogonia and spermatocytes contained abundant glucosyl (Con A and WGA lectins) and fucosyl (AAA lectin) residues. In spermatids, galactosyl (SBA and PNA lectins) and glucosyl (Con A and WGA lectins) residues increased progressively throughout spermiogenesis, and fucosyl (AAA lectin) residues decreased. As compared with healthy boars, the scrotal testis of unilateral cryptorchid boars showed decreased amounts of fucosyl (AAA lectin) and galactosyl (HPA and DBA lectins) residues on the Sertoli cell apical cytoplasm; spermatocytes exhibited higher content of glucosyl (Con A lectin) residues and spermatids showed altered nature of glucosyl (Con A and WGA lectins) and galactosyl (SBA and PNA lectins) complexes. In abdominal testes of unilateral and bilateral cryptorchid boars, immature Sertoli cells and spermatogonia showed decreased fucosyl (AAA lectin), and increased glucosyl (Con A and WGA lectins) and galactosyl (SBA and PNA lectins) contents. These results suggest that the seminiferous epithelium of healthy boars has polarized activity with the apical compartment implicated in germ cell-Sertoli cell adhesion and interaction, in transport of ions, substrates and fluids, and in acrosomal differentiation. In scrotal testes, unilateral abdominal cryptorchidism could lead to defective germ cell-Sertoli cell adhesion, impaired acrosomal differentiation and increased ionic transport in the apical compartment of the seminiferous epithelium. Unilateral and bilateral cryptorchidism could induce increased ionic transport and membrane permeability in the seminiferous epithelium of abdominal testes.     

MUSCLE HISTOCHEMISTRY AND MUSCLE FUNCTION

Abstract. Henriksson, K. G. (Neuromuscular Unit, Department of Neurology, Clinical Neurophysiology and Pathology I, University of Linköping, Linköping, Sweden). Muscle histochemistry and muscle function. Acta Paediatr Scand, Suppl. 283: 15, 1980.—A short review of the histochemical characteristics of the different muscle fibre types is given. The possibility of changing contraction time, strength, and endurance by physical training is discussed.     

Adenocarcinoma of Rectosigmoid Colon

A case of hybrid leukemia is presented. A 30-year-old man had two blast cell populations with bone marrow. The majority of the blast cells had B-lymphoid markers on their surfaces and a small number of cells had both lymphoid markers and penoxidase activity on the same cell. Immunoelectron microscopy combined with ultrastructural cytochemistry (MPO reaction) demonstrated the biphenotypic nature of the blast cells.     

黑质—纹状体环路内胆硷能结构——AchE药理组化研究结合HRP追踪

用乙酰胆碱酯酶(AchE)药理组织化学方法结合辣根过氧化物酶(HRP)追踪研究黑质—纹状体环路的胆硷能神经元及其纤维联系。结果显示尾、壳核内有两种AchE阳性神经元,它们不被黑质注射HRP所标记。黑质内纹投射细胞呈AchE阳性。本文对AchE阳性神经元和黑质—纹状体环路的关系进行了讨论。     

小鼠H_(22)肿瘤的酶组织化学和超微结构观察

光镜下H_(22)肿瘤细胞弥漫索样排列,网状纤维包绕瘤细胞团形成巢状,胶原纤维极少。碱性磷酸酶反应产物主要附着于细胞膜部位;酸性磷酸酶细胞内散在分布;细胞色素氧化酶及乳酸脱氢酶弥散位于细胞浆内。各种酶反应产物均较匀细。扫描和透射电镜示瘤细胞表面微绒毛发达,细胞间可见桥粒连接,线粒体、粗面内质网和多聚核糖体丰富,胞浆内细胞器有极性分布倾向。以上结果不仅为该瘤株的进一步应用提供了有益的参考资料,同时提示关于H_(22)肿瘤已转变为多形细胞肉瘤的结论是值得商榷的,其应是一株低分化肝癌腹水瘤模型。