Issei Nishimori

Incidence of female breast cancer among atomic bomb survivors, Hiroshima and Nagasaki, 1950-1990.

An incidence survey of the Life Span Study (LSS) population found 1093 breast cancers among 1059 breast cancer cases diagnosed during 1950-1990. As in earlier breast cancer surveys of this population, a linear and statistically highly significant radiation dose response was found. In the analysis, particular attention was paid to modification of radiation dose response by age at exposure (e) and attained age (a). Dose-specific excess relative risk (ERR(1Sv)) decreased with increasing values of e and a. A linear dose-response model analysis, with e and a as exponential age modifiers, did not conclusively discriminate between the two variables as modifiers of dose response. A modified isotonic regression approach, requiring only that ERR(1Sv) be monotonic in age, provides a fresh perspective indicating that both e and a are important modifiers of dose response. Exposure before age 20 was associated with higher ERR(1Sv) compared to exposure at older ages, with no evidence of consistent variation by exposure age for ages under 20. ERR(1Sv) was observed to decline with increasing attained age, with by far the largest drop around age 35. Possible explanations for these observations are discussed, along with research approaches that might provide more information.

PATHOLOGICAL STUDY ON MUCOSAL CHANGES IN SMALL INTESTINE OF RAT BY ORAL ADMINISTRATION OF RICIN: I. Microscopical Observation

A histological study on small intestine of Wistar rats after oral administration of ricin, a proteinous toxin from castor bean seeds, was carried out. In Experiment I, the jejunum was examined at 1, 2, 5, 10, 15, 20, 24, and 40 hours after oral administration of ricin 30 mg/kg. In Experiment II, ricin was administered at dose of 1, 3, 5, 10, 15, 30, and 60 mg/kg, and after 5 hours the jejunum, mid‐portion, and ileum were examined. For comparison, ricin 0.5 mg/kg was administered intraperitoneally and castor bean hemagglutinin (CBH) 30 mg/kg orally. In both experiments, the changes of mucosa were essentially similar dependent on time‐lapse and dose respectively, which were atrophy of villus, elongation of crypt, degeneration of epithelium, decrease of goblet cell, fusion of intervillous epithelia, infiltration of neutrophils and eosinophils, and dissociation between epithelium and lamina propria. These changes were most manifest in the jejunum that was contacted with ricin first in a high concentration. In contrast, intraperitoneal administration of ricin caused only dissociation between epithelium and lamina propria and oral administration of CBH caused only milder atrophic changes. The evidences suggest that the mucosal changes by oral administration were caused by direct contact with ricin.

Glioblastoma with sarcomatous component associated with myxoid change

SummaryThe case of a 22-year-old female suffering from glioblastoma with sarcomatous component (WHO; gliosarcoma) is presented. The tumor consisted of glioblastomatous and sarcomatouos components, and in part of the pleomorphic astrocytomatous region of the glioblastoma there was a prominent production of myxoid matrix. On the basis of its histochemical and immunohistochemical characteristics, the present case strongly suggested that glial cells of neuroectodermal origin assume part of the responsibility for production of myxoid material.

Endothelial intracellular vacuoles in angiosarcoma of the scalp

SummaryUltrastructural observations of an angiosarcoma of the scalp revealed intracellular vacuoles both in undifferentiated and in angiomatous areas of the tumor. These structures resembled closely the ‘intracytoplasmic vacuoles’ described by Furusato et al. (1984); they did not appear to result from tangential sectioning through the tips of capillary loops since single endothelial cells often contained more than one intracellular vacuole. The vacuoles were separated from the cytoplasm by a membrane that was complete in some and interrupted in others. Ultrastructural examination of serial sections of endothelial cells revealed occasional tears in the septum between two adjacent intracellular vacuoles. It is suggested that a number of membrane-bound vacuoles may develop in the cytoplasm of autolytic endothelial cells and that subseuent fusion results in the production of a single intracellular vacuole.

Experimental stress ulcer and gastric catecholamine contents in spontaneously hypertensive rats

SummaryTo determine the role of the sympathetic nervous system in the development of stress ulcer, we carried out experiments on spontaneously hypertensive rats (SHR) exposed to restraint and water immersion stress for 7 h. Normotensive Wistar-Kyoto rats (WKY) were used as controls. Catecholamine (CA) contents in gastric tissues, divided into mucosal and muscular layers of both antrum and corpus, were quantitated by high-performance liquid Chromatographic electrochemical detection (HPLC-EC). The stress ulcer formation was much less frequently induced in SHR than in WKY. The noradrenaline (NA) contents in all regions of gastric tissues were higher in SHR than in WKY. The contents of adrenaline (A) and dopamine (DA), present in small quantities in gastric tissues showed no difference between SHR and WKY. After exposure to stress, the NA contents in mucosal and muscular layers of the gastric corpus decreased significantly in both SHR and WKY, whereas the value remained higher in the former. On the contrary, a remarkable increase of A contents (probably released from the adrenal medulla by the stress) was observed in all gastric tissues, of both SHR and WKY. Increase of the A contents in the mucosal layer was remarkable in the SHR. The DA contents increased in both strains. These results suggest that the peripheral sympathetic hyperfunction in the stomach in the SHR may have an inhibitory role in stress ulcer formation.

EFFECT OF MAGNESIUM DEFICIENCY ON ULTRASTRUCTURAL CHANGES IN CORONARY ARTERIES OF SWINE

The effects of magnesium (Mg) deficiency on the coronary arteries of 27 Yorkshire swine were studied by light and electron microscopy. The experimental animals were divided into 4 groups which received the following supplements: Group I, basal ration with adequate Mg (540 mg/kg diet), Group II, basal ration with insufficient Mg (270 mg/kg diet) Group III, 10% milk powder with adequate Mg (540 mg/kg diet), Group IV, 10% milk powder with insufficient Mg (270 mg/kg diet). Serum analysis indicated that dietary low Mg supplementation decreased cholesterol levels and increased phospholipid concentrations significantly. The highest magnitude and incidence of intimal thickening were observed in the coronary arteries of Group IV (p < 0.003). No significant intimal thickening was detected in any of the other groups. Ultra‐structural studies revealed a greater frequency of degenerated cells in Group III and IV (p<0.01). Numerous calcifications were observed in only Group IV. These data suggest that moderate Mg deficiency can promote atherosclerosis in combination with some atherogenic diet, and that the presence of smooth muscle cell degeneration is important in order for a magnesium deficiency to exert an effect on the coronary artery of swine.

PRIMARY MALIGNANT FIBROUS HISTIOCYTOMA OF THE ENDOMETRIUM

Malignant fibrous histiocytoma (MFH) has become one of the most common malignancies occurring in soft tissue. To our knowledge, the present case is the first of MFH occurring in the endometrium. The uterus removed from a 47‐year‐old woman demonstrated a large multinodular endometrial lesion with gross invasive foci in the myometrium and the left oviduct. Microscopically, the endometrial tumor and the invasive lesions were composed of dense sheets of markedly pleomorphic cells consisting of fibroblast‐like cells, histiocyte‐like cells, foamy histiocytes, benign appearing multinucleated giant cells resembling either osteoclasts or Touton giant cells, and bizarre tumor giant cells. Some of the tumor cells showed phagocytic activities. The tumor cells were oriented in a random or haphazard fashion and classical storiform and fascicular patterns were not observed. The tumor was diagnosed as MFH consisting exclusively of so‐called pleomorphic pattern. The patient is alive without evidence of disease, months following total hysterectomy and bilateral salpingo‐oophorectomy.

Disseminated intravascular coagulation induced by generalized cytomegalic inclusion disease during steroid therapy for polymyositis

A 56‐year‐old woman came to the hospital with fever and skin eruptions. A rise in myogenic enzyme and the presence of antileucocyte antibody were noticed, along with the gradual appearance of myalgia in both lower extremities, and muscle weakness. Steroid therapy was started under the diagnosis of polymyositis. The steroid was reduced because of mental disturbance but immediately the patient developed high fever. Various forms of treatment were carried out but there was no improvement, and the patient died. At autopsy there were scattered purpura on the skin, and the muscles were atrophic and yellowish‐grey in color. Histopathologically, there was inflammatory cell infiltration and muscle fiber degeneration visible in many of the muscles, and the findings showed evidence of polymyositis. There were intranuclear inclusions in the lungs, ovaries, and adrenal glands, and this was diagnosed as generalized cytomegalic inclusion disease. Fibrin thrombi were found in the kidneys, lungs, and adrenal glands and this was pathologically diagnosed as disseminated intravascular coagulation. Endothelial cell damage caused by cytomegalovirus was assumed to be involved to a large extent in triggering the disseminated intravascular coagulation. ACTA PATHOL. JPN. 35: 723–730, 1985.

Intraventricular neuroblastoma. A light and electron microscopic study and review of the literature.

The neuroblastoma can generally be diagnosed from the histologic findings, but electron microscopic evidence is often required. A neuroblastoma occurring in the lateral ventricle of a 17-year-old female is described in this report. The tumor cells, which were strongly stained with hematoxylin, contained a small round or oval nucleus with scant cytoplasm and an obscure cell border as observed by light microscopy. No calcification, mitoses and typical ganglion cells were detected. An electron microscopic examination disclosed dense-cored vesicles, cell processes, clear vesicles, dumbbell-shaped dense bodies, microtubules and zonulae adherentes in the tumor cells. These findings suggest differentiation of the tumor cells to neuronal cells.

An autopsy case of alkaptonuria with ochronosis.

An autopsy case of alkaptonuria in a 47‐year‐old man is reported. Since childhood, he had noticed black color of his excreted urine. Autopsy revealed characteristic pathologic changes due to alkaptonuria such as ochronosis and ochronotic spondylosis, etc. The primary cause of death was pontine hemorrhage. Histologically, two types of ochronotic pigment were observed. Enzyme activity of homogentisate oxygenase in the liver and kidney homogenate was extremely decreased.