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Biomedical subjects

W Mori

Publications and source records attributed to W Mori.

At least 37 records · Page 2Linked to original sources
PubMed1988

The organ distribution of [3H]endotoxin following partial hepatectomy.

3H-labeled endotoxin was intravenously injected into Wistar rats 24 hours following 70% hepatectomy and also into the normal rats. They were sacrificed 12 hours, 24 hours or 5 days after the injection. Microscopical autoradiography was performed on the rats' organs. The distribution of endotoxin in the organs was investigated by quantitatively measuring their radioactivity. Endotoxin was taken up mainly by Kupffer cells of the liver in all the groups. Endotoxin was observed also in macrophages of the spleen and the lung in all the groups. The amount of endotoxin per 1 g organ weight of the hepatectomized rat was significantly smaller in the liver, and significantly larger in the spleen, lung and blood (per 1 ml) than that of the control groups early after hepatectomy. These differences of the organ accumulation of endotoxin between groups diminished 5 days later. Deficient tolerance of the liver to endotoxin at the peak phase of regeneration following partial hepatectomy was suggested.

Animals↗
PubMed1988

Fate of 3H-labeled endotoxin in partially hepatectomised rats.

Organ distribution of endotoxin was compared in normal and previously hepatectomised rats after administration of endotoxin lipopolysaccharide labeled at the galactose moiety. Most of the radioactivity was found in the liver in both cases, but total recovery was much higher in the organs of normal rats. In the liver, the amount of endotoxin per total organ and per 1 g organ weight was significantly reduced in the hepatectomised rats as compared with the intact controls. In normal rats, the radioactivity decreased 12 to 24 hours in the liver, but in the hepatectomised rats, no significant change was observed during this period. The total radioactivity in the lungs, spleen and blood (1 ml), as well as that per unit weight bases, was significantly higher in the hepatectomised rat than in normal rats. These results and autoradiographical studies suggest that endotoxin clearance activity of Kupffer cells in the liver is decreased by partial hepatectomy of the rats at the peak phase of regeneration, and that remaining endotoxin flow out of the liver is disposed mainly by the macrophages in the spleen.

Animals↗
PubMed1987

Pineal gland in old age; quantitative and qualitative morphological study of 168 human autopsy cases.

Age-related changes of human pineal gland were studied morphologically on 168 autopsy cases. Pineal weight in the formalin-fixed condition was 99 +/- 56 mg in males (n = 88, mean age 78 years) and 91 +/- 41 mg in females (n = 80, mean age 79 years), which showed no sexual difference (P = 0.290). There was no correlation between pineal weight and age of the patient (r = 0.0678, P = 0.191, n = 168). The pineal volume calculated as a spheroid was directly proportional to the weight (r = 0.904, n = 167, P = 0.000). A significant correlation existed between pineal weight and the degree of calcification (r = 0.231, P = 0.002, n = 156). The density of the pineals decreased with age (r = -0.164, P = 0.017, n = 167). The degree of calcification and cyst formation did not increase with age, but the grade of cyst formation was related to the pineal volume (P = 0.0002). Some pineals of the patients over 90 years old showed no calcification and appeared indistinguishable from the ones of the younger subjects. The weight and volume of the pineals of the patients with hypertension was appreciably greater than those of the non-hypertensive patients. These results indicate that human pineals do not necessarily degenerate progressively after involution.

Age Factors↗
PubMed1987

Acute, massive, haemorrhagic adrenal necrosis experimentally produced by the Shwartzman mechanism in rabbits.

Acute and severe haemorrhagic necrosis of the adrenal was produced experimentally in rabbits by means of intravenous injection of endotoxin after pretreatment by adrenocorticotropic hormone (ACTH) administration. The change occurred mainly in the zona fasciculata of the adrenal cortex, and its pathology was quite similar to that of the Shwartzman reaction. Numerous microthrombi were found in and around the lesion, but no marked changes were seen in other parts of the body. Heparin administration was very effective in preventing the necrosis. The pathogenesis of this lesion was postulated to be a univisceral Shwartzman mechanism in the adrenal. This seems to be a good experimental model for massive haemorrhagic necrosis of the adrenal in man, for example in the Waterhouse-Friderichsen syndrome, the pathogenesis of which has been assumed to involve intravascular clotting. It is suggested that hyperfunction of the adrenal cortex caused by ACTH administration could be a preparative condition for the Shwartzman reaction.

Acute Disease↗
PubMed1987

Early adrenal infection by herpes simplex virus type-1 (Miyama + GC strain): special reference to inoculation dose and spread from the adrenal to the central nervous system.

Male C3H/HeN mice, aged 5 weeks, were inoculated intraperitoneally (i.p.) with different doses (1 x 10(3), 1 x 10(5), 5 x 10(5), 1 x 10(6) pfu) of the herpes simplex virus type-1 (HSV-1) (Miyama + GC strain). The LD50 of this virus was 10(2) pfu (i.p.) per mouse. All the mice in each group died 12 days after inoculation. Adrenal necrosis was found to be dose-dependent, the threshold dose being 5 x 10(5) pfu. In addition, encephalitis and inflammatory cell infiltration in abdominal ganglia appeared in 3-4 days after inoculation. By the plaque method, HSV-1 was detected first in the adrenal glands, then in neurons in the spinal cord and the brain. These findings suggest that in mice inoculated with doses of virus sufficient to infect the adrenal gland, HSV-1 spreads to the central nervous system through peripheral nerves after replication in the adrenal.

Adrenal Gland Diseases↗
PubMed1987

A study on the mechanism of acute hepatic necrosis following partial resection of the liver.

Endotoxin was injected intravenously into rats 48 hours after 70% hepatectomy. The remaining hepatic tissue demonstrated marked hemorrhagic necrosis in high frequency. However, hepatic lesions were slight in other groups such as the group in which heparin was administered simultaneously with injection of endotoxin 48 hours after 70% hepatectomy and the group in which endotoxin was injected 10 days after 70% hepatectomy. Defining of this marked necrosis to be a univisceral Shwartzman reaction in the liver may be justified from (i) conformity of experimental manipulations to those employed in the Shwartzman reaction, (ii) macroscopical as well as histological evidence, (iii) formation of microthrombi in hepatic lesions, (iv) inhibition of occurrence of the reaction by heparin, and (v) absence of any remarkable change in other organs. We concluded that the hepatic regenerative state might correspond theoretically to a state of preparedness for the Shwartzman reaction.

Animals↗
PubMed1987

Anti-glucocorticoid effects of melatonin on adult rats.

To extend our previous experiment on anti-glucocorticoid effects of melatonin which was performed under a very special condition using young rats, we have carried out another experiment of long term administration of pineal hormone melatonin to adult female rats which were conditioned by overdose glucocorticoid. The results clearly demonstrated significant protection, by melatonin, from the injurious effects of a glucocorticoid, dexamethasone: decrease of body weight gain, atrophy of the thymus and adrenals, and elevation of the level of total cholesterol in blood. Thus, it has been clarified that anti-glucocorticoid effects of melatonin could be shown experimentally not only in young rats but also in adults, and also, could be really seen not only in short term experiment but also in longer ones. Anti-glucocorticoid effects of melatonin seem to be of considerably wide range, not being limited to occur under a special condition, including the age of animals, in experiments.

Adrenal Glands↗
PubMed1987

An autopsy study of lung cancer in University of Tokyo for the last 27 years, from 1958 to 1984, with special reference to the characteristics of lung cancer in Japan.

Four hundred and sixty-five male and 159 female consecutive autopsy cases of lung cancer, autopsied over the 27 years from 1958 to 1984, were analysed and were compared with other materials and mortality statistics, including statistics from other countries. Malignant tumor autopsy cases are gradually increasing and now comprise more than 60% of total autopsy cases. The percentage of lung cancer cases among all autopsy cases was 7% in males and 4% in females. The percentage of lung cancer in autopsies of patients with malignancies was about 13% for males and 9% for females. The most frequent fatal malignant tumors were gastric cancer, lung cancer, and leukemia. The relative incidence of gastric cancer was decreasing, while that of lung cancer was increasing. In the distribution of the histological types of lung cancer, adenocarcinomas were the most frequent types in both sexes. As has been noted in mortality statistics, we noticed a gradual shift in the peak age of lung cancer autopsy cases towards older patients. During the period under study, the peak shifted from patients in their sixties to patient in their seventies; this was true for most of the major histological types in both sexes. The male/female ratio of all lung cancer cases was 2.9, which was much lower than the ratio found in the United States and Europe, and very similar to the ratio of the mortality rates in Japan and other Asian countries. It was pointed out that the male/female ratios by age-group in each country is a very good reflection of the histological distribution.

Adult↗
PubMed1987

A light and scanning electron microscopic study of hepatic veno-occlusive disease.

Hepatic veno-occlusive disease, which was observed in a patient with hepatic coma, was examined by scanning electron microscopy (SEM), and correlated with its histology. Postmortem examination disclosed microscopic occlusion of the centrilobular and sublobular veins in the liver. These veins were occluded, partially or completely, by intimal and medial thickening of their walls due to proliferation of collagen and reticulin fibers. In addition to venous obliteration, which had not been demonstrated by other techniques, frequent occlusion of the sinusoidal opening into the central veins was observed by SEM. The size and distribution of the openings were irregular in comparison with those in normal controls. There was no evidence of fibrin thrombus formation in the veins. This case exemplified the usefulness of the application of SEM to autopsy material.

Aged↗
PubMed1987

Postinflammatory mitral and aortic valve prolapse: a clinical and pathological study.

In this study we reevaluated whether the sole cause of mitral valve prolapse (MVP) and aortic valve prolapse (AVP) is myxomatous degeneration. Forty-two surgical cases of prolapsed valves with mitral and/or aortic regurgitation were reviewed (AVP in nine, MVP in 27, and combined AVP and MVP [CVP] in six). On microscopic examination, myxomatous degeneration was observed in 20 patients, including six with AVP, 13 with MVP, and one with CVP. In the other 22 patients, including three with AVP, 14 with MVP, and five with CVP, microscopic examination revealed fibrosis with vascularization and scattered infiltration of inflammatory round cells caused by postinflammatory changes with or without chronic inflammation. We coined the term "postinflammatory valve prolapse" (PIVP) to describe these valves. Both postinflammatory and myxomatous degeneration were observed in seven patients with floppy mitral valves attributable to PIVP. Rupture of chordae tendineae was present in six patients with myxomatous mitral valve and three with PIVP. Seven patients with PIVP had a history of rheumatic fever. The results suggest that valvular prolapse is produced not only by myxomatous degeneration but also by postinflammatory changes, including those caused by rheumatic fever.

Adult↗
PubMed1987

Origin of the medulloblastoma experimentally induced by human polyomavirus JC.

The origin of the medulloblastoma induced by JC virus (JCV) in golden hamsters was investigated by the in situ hybridization method. After inoculation of JCV into newborn hamsters, a few migrating cells in the cerebellar molecular layer as well as several cells in the internal granular layer hybridized with an antisense mRNA probe of JCV T-antigen on the 10th day. The number of cells positive for this probe decreased on the 15th and 20th days. Moreover, an incipient medulloblastoma consisting of many cells positive for T-antigen mRNA was noticed in the cerebellar internal granular layer 30 days after inoculation. About 6 months post inoculation, 95% of the animals had succumbed to medulloblastoma. Therefore, the origin of the medulloblastoma seemed to be the cells in the cerebellar external granular layer that were infected by JCV, that migrated normally through the molecular layer to the internal granular layer, and that began to proliferate to become medulloblastoma. When 5-day-old hamsters were inoculated, a few cells positive for T-antigen mRNA were detected in the cerebellum within a month. In the long-term observation, the ratio of medulloblastoma induction decreased as the age of the animals at inoculation increased. These results support the idea that JCV infects and transforms the cells in the cerebellar external granular layer, because this layer appears only transiently in newborn hamsters.

Animals↗
PubMed1986

Immunohistochemical localization of apolipoprotein E in atherosclerotic lesions of the aorta and coronary arteries.

The distribution of apolipoprotein E (apo E) immunoreactive substances (IRS) in atherosclerotic lesions and lesion-free areas of the aorta and coronary arteries obtained from 17 autopsied cases was studied using a specific anti-apo E serum and the unlabeled peroxidase-antiperoxidase (PAP) method. In fatty streak lesions of the aorta, many cells containing apo E-IRS were found in the deeper layer of the intima and diffuse staining of apo E in the extracellular spaces was also noted. In more advanced lesions apo E-positive cells could not be found. Immunohistochemical findings of coronary arteries differed distinctly from those of the aorta in that the apo-E-positive cells were absent in the deeper layer of the intima. The endothelial cells of coronary arteries, but not those of the aorta, showed positive staining for apo E.

Adult↗
PubMed1986

Systemic hemangiomatosis.

An autopsy case of unusual vasoformative tumor is presented. The distribution of this tumor was restricted to the organ of the hematopoietic system such as the spleen, liver, and whole bone marrow. Although it may be considered as a variant of certain splenic hemangiosarcoma because of widespread dissemination, both the benign-looking histological features and specific distribution of this tumor suggest its hamartomatous nature. Several additional similar cases in the literatures are briefly reviewed from the viewpoint of systemic hemangiomatosis.

Female↗
PubMed1986

Fatal hepatic necrosis after shock.

A clinicopathological study was undertaken in 15 cases of massive hepatic necrosis after shock. The GOT and GPT level exceeded 1000 units in 10 cases. The 15 cases consisted of 3 diagnosed as fulminant hepatitis clinically and 12 diagnosed as disseminated intravascular coagulation (DIC) or multiple systemic organ failure (MOF) from the unremarkableness of liver dysfunction. It was noteworthy that sepsis and surgery were closely associated with these lesions. The weight of the liver at autopsy ranged from 800 to 2,700 g. Liver necrosis was macroscopically characterized by clear demarcation of the necrotic areas sharply separated from the surrounding liver parenchyma, showing the appearance of so-called "map-like necrosis". Microscopically, the lesions in these subjects showed mainly the pattern of centrilobular necrosis. As observed in the burn shock case (case 12), the shock which provoked in different phases of time seemed to have repeated its attack. These liver necroses were considered to result from severe systemic circulatory disturbance or intrahepatic circulatory disturbance. The possibility is indicated that the generalized or univisceral Shwartzman reaction, and repeated and combined severe shock participated in the pathogenesis. Fibrin thrombi aggrevate tissue perfusion and accelerate anoxia. Heparin therapy seemed effective in these cases if administered at an appropriate time.

Adolescent↗
PubMed1986

Anti-glucocorticoid effects of melatonin in young rats.

Administration of the pineal hormone melatonin to young female rats provided significant prevention of the injurious effects (decrease of body weight gain, atrophy of the thymus and adrenals, glucosuria, elevation of the blood level of glucose, free fatty acid, triglyceride, and total cholesterol) caused by three different glucocorticoids, i.e. dexamethasone, prednisolone, and hydrocortisone. Although these protective effects of melatonin were slightly more remarkable in dexamethasone-treated rats than in prednisolone- or hydrocortisone-treated rats, our hypothesis of melatonin's anti-glucocorticoid effects is said to have been confirmed rather universally and with a considerably wide range through this experiment.

Adrenal Glands↗
PubMed1986

Ultrastructural localization of Thorotrast (thorium dioxide) in human liver by analytical scanning electron microscope.

The distribution of thorium dioxide (Thorotrast) in the liver from a Thorotrast-administered autopsy case was examined stereographically by analytical scanning electron microscopy. Thorium particles were detected in the macrophages of the portal triad and hepatic sinusoid. These macrophages were irregularly shaped and tended to be aggregated. In the sinusoid, accumulation of the macrophages formed a thrombus-like structure. Furthermore, observed in the sinusoid were free Thorotrast particles that appeared to have been released into the sinusoid as a result of breakdown of the macrophages (Kupffer cells).

Carcinoma, Hepatocellular↗