Primary liver carcinoma and liver cirrhosis in atomic bomb survivors, Hiroshima and Nagasaki, 1961-75, with special reference to hepatitis B surface antigen.

During 1961-75, 128 cases of primary liver carcinoma (PLC) in the Radiation Effects Research Foundation life-span study extended sample and 301 cases of liver cirrhosis in the pathology study sample were observed. The presence of hepatitis B surface antigen (HBsAg) was assessed in all of the cases with the use of orcein and aldehyde fuchsin stains and was confirmed by the immunofluorescence technique. The incidence of PLC was two times higher in Nagasaki than in Hiroshima, which was statistically significant, but little difference was noted in the prevalence of cirrhosis in the two cities. Findings that might possibly explain the higher PLC incidence in Nagasaki were 1) the 2.3 times higher presence in Nagasaki than in Hiroshima of HBsAg in the livers of subjects without liver disease and 2) the two times higher prevalence in Nagasaki than in Hiroshima of cirrhosis with PLC. We believe that the higher incidence of PLC in Nagasaki is attributable to hepatitis B virus infection, although other factors (e.g., immunologic competence affected by radiation) cannot be excluded. In both cities, a suggestive relationship of radiation dose to cirrhosis prevalence, but not to PCL prevalence, was noted. To clarify possible radiation effects on cirrhosis prevalence, further follow-up of the populations of these two cities is necessary.

Cells constituting cerebellar hemangioblastomas. Ultrastructural study.

Five capillary hemangioblastomas exhibiting a range of histologic variations common to this tumor were studied using electron microscopy. The capillary hemangioblastoma were composed commonly of three cell lines -- stromal cells, endothelial cells and pericytes. In addition, extramedullary hematopoietic foci were seen in the tissue of one case. We regarded all these cellular elements as neoplastic components. The interconvertibility among them was not confirmed. The capillary hemangioblastomas were highly organized by those multiple cell lines. The histologic pattern of growth was arbitrarily subgrouped into stromal cell prominent type and capillary prominent type. Intermediate features between the two types were observed. These different types would depend on relative proportions and the degree of maturity of the constituting cell elements. From the histogenetic point of view, we considered capillary hemangioblastomas as being a hamartomatous tumor.

Frequency of Alzheimer's neurofibrillary tangle in the brains of progressive supranuclear palsy, postencephalitic parkinsonism, Alzheimer's disease, senile dementia and non-demented elderly person.

The frequency and the distribution of Alzheimer's neurofibrillary tangles were examined in those cases of progressive supranuclear palsy (one case), postencephalitic parkinsonism (one case), Alzheimer's disease (two cases), senile dementia (two cases) and non-demented elderly person (three cases). The light microscopic pattern of Alzheimer's neurofibrillary tangles seen in progressive supranuclear palsy was similar to those in postencephalitic parkinsonism, Alzheimer's disease, senile dementia and non-demented elderly person. Some differences in the frequency and the distribution of Alzheimer's neurofibrillary tangles were demonstrated.

Cystic prolactinoma: a variant of "transitional cell tumor" of the pituitary.

Pituitary tumors with features of both Rathke's cleft cysts and adenohypophysial adenomas are extremely rare and have been termed "transitional cel tumors." The ultrastructural features of one of these tumors has been reported, demonstrating cells with features transitional between those of adenohypophysial cells and Rathke's cleft cells, along with other cells with the distinctive features of either cell type. We report a case of a prolactin-secreting "transitional cell tumor" with similar light-microscopic and ultrastructural features. Additionally, the transitional cells in our case exhibited abundant intracellular mucin production. This represents a variant of "transitional cell tumor" of the pituitary gland.

Ultrastructural study of the human neurohypophysis. II. Cellular elements of neural parenchyma, the pituicytes.

The pars nervosa of the neurohypophysis from 12 patients undergoing hypophysectomy for palliative treatment of advanced carcinoma was studied electron microscopically. Special attention was given to the cellular elements, the pituicytes. Five different classes of pituicytes, with various transitional forms, were elucidated based on their ultrastructural characteristics: (1) The most common type, referred to as "major pituicytes", is reminiscent of astrocytes. (2) "Dark pituicytes" are thought to represent different functional stages of the "major pituicytes". (3) "Ependymal pituicytes" are believed to provide ultrastructural evidence that human pituicytes are phylogenetically derived from ependymal cells. (4) "Oncocytic pituicytes" were observed in all cases and are of unknown significane. (5) The ultrastructural features of "granular pituicytes" suggest the existence of an active uptake and catabolism of extracellular material by pituicytes, probably through "ultraphagocytosis" or "endocytosis". These five classes of pituicytes are considered to represent different functional forms of one cell line that originates phylogenetically from the ependyma.

Ultrastructural study of the human neurohypophysis. I. Neurosecretory axons and their dilatations in the pars nervosa.

Neurosecretory axons and their dilatations in the pars nervosa of the human neurohypophysis were studied electron microscopically. The axons are of two different types based on their content of neurosecretory granules (NSGs): (i) NSGs of Type A are 100-300 nm, and (ii) NSGs of type B are 50-100 nm in diameter. While fibers (or axons) of type B were scarce, showing simple swellings and terminal formations, fibers of type A were ubiquitous in the human pars nervosa, exhibiting numerous dilatations with a diversity of internal structure, apparently representing the ultrastructural manifestation of intraaxonal turnover of neurohypophysial hormones. Based on the predominating aspect of their internal structure, dilatations of type A-fibers were classified into six different types, with various transitional forms: Type I is characterized by abundant NSGs; type II by prominent mitochondria; type III by abundant lysosomal bodies; type IV by an electron-lucent matrix with few organelles; type V by prominent tubuloreticular profiles; and type VI by numerous microvesicles. The functional significance of each type is discussed and a scheme of possible interrelationships between these dilatations is proposed.

Ultrastructural study of the human neurohypophysis. III. Vascular and perivascular structures.

The vascular and perivascular regions of the human neurohypophysis were studied electron microscopically. The abluminal basement membrane, perivascular space, luminal basement membrane and endothelium are interposed between the neural parenchyma and the blood stream. The capillaries are fenestrated, with pores measuring 30 to 50 nm in diameter. The perivascular and intercellular spaces form prominent networks that penetrate between rows of neurohypophysial parenchymal cells. The perivascular space contains pericytes, histiocytes, fibroblasts and mast cells, with ultrastructural features typical of each cell type. No transitional forms between histiocytes and pericytes were observed. A schema for the extracellular flow of neurohypophysial hormones through the sinusoidal and perivascular spaces is proposed, suggesting an important role for the pituicytes and their intercellular junctions in the control of hormone release.

Biochemical and histocytochemical studies on response of ammonia-producing enzymes for nh4cl-induced acidosis.

NH4Cl-induced acidosis in rats resulted in renal enlargement and increase in activities of phosphate-dependent glutaminase and glutamic dehydrogenase. The renal enlargement was associated with protein synthesis but not deoxyribonucleic acid synthesis. In control rats histochemical activity of glutamic dehydrogenase was seen dominantly in the proximal straight tubule. In acidotic rats high activity was noted in the proximal convoluted tubule as well as in the proximal straight tubule. By electron microscopy reaction product was in mitochondria. The results suggest that urine ammonia is produced in mitochondria of epithelial cells in the proximal straight tubule in both normal and acidotic rats. Increased enzyme activity in acidotic rats is largely associated with epithelial cells of the proximal convoluted tubule.