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Biomedical subjects

K Ohtsubo

Publications and source records attributed to K Ohtsubo.

At least 91 records · Page 5Linked to original sources
PubMed1987

Effects of nivalenol on the bone marrow in mice.

In order to investigate the toxic effects of nivalenol, one of the trichothecene mycotoxins, we performed a short-term feeding trial for 24 days using feed supplemented with rice artificially molded with nivalenol producing fungus, Fusarium nivale Fn 2B, in female C57BL/6CrSlc SPF mice. A significant erythropenia and slight leukopenia were observed in the 30 ppm group, but no marked changes were observed in other hematological parameters, feed consumption, body weight gain, or weights of the liver, spleen, and thymus. Ultrastructural studies also revealed polyribosomal breakdowns of the bone marrow cells in the 30 ppm group.

Animals↗
PubMed1987

Spontaneous regression of a carcinoma of the residual stomach with latent carcinoma of the pancreas: autopsy report.

An 85-yr-old female was subjected to subtotal gastrectomy for double early carcinomas. Five years later a hemispheric protuberant lesion was observed endoscopically in the residual stomach and found by biopsy to be adenocarcinoma. Because of her poor general condition, anticancerous drugs were not given. She gradually became debilitated, and died 10 months later. At autopsy there was no protuberant lesion in the residual stomach and no cancer was found on multiple-step microscopical sections. A small pancreatic cancer with regional lymph node metastasis was found incidentally. In an immunohistological examination, only the carcinoma of the pancreas and its lymph node metastasis were positively stained with monoclonal anti-CA19-9 antibody-PAP. This is a rare case of a spontaneous regression of human gastric carcinoma, and was proved by autopsy.

Adenocarcinoma↗
PubMed1986

Expression of the c-Ha-ras and c-myc genes in aflatoxin B1-induced hepatocellular carcinomas.

Expression and activation of several c-oncogenes in seven hepatocellular carcinomas from seven separate rats treated with aflatoxin B1 (AFB1) were examined by Northern and Southern blot analyses. Both c-Ha-ras and c-myc transcripts were elevated at high levels in all hepatomas. Moreover, in one of them, T2-1 hepatoma, the c-myc gene was amplified only in a tumor part of liver without significant rearrangement. N-ras specific transcripts were not elevated in these hepatomas. The present data suggest that the consistently increased expression or deregulation of the c-myc and c-Ha-ras genes may play an important role in the development of hepatomas induced by AFB1.

Aflatoxin B1↗
PubMed1986

A flow cytofluorometric study on age-dependent ploidy class changes in mouse hepatocyte nuclei.

To quantitate the age-dependent hyperploidization of mouse hepatic cell nuclei, a cytophotometric study using FACS III was performed. The isolated nuclei from the liver of C57BL/6CrSlc mice at various ages were stained with chromomycin A3. The fraction of polyploid nuclei was increased with age and invariably greater in male than in female animals of corresponding ages. The highest ploidy class observed was 16C, but from the analysis of polyploidization ratio, increase in 4C and 8C nuclei was considered to be the characteristic of the age-related change.

Aging↗
PubMed1985

[Do giant negative T waves represent apical hypertrophic cardiomyopathy? Left ventriculographic and cardiac biopsy studies].

Whether giant negative T waves (GNT) of 1 mV or greater represent the electrocardiographic characteristics of idiopathic cardiomyopathy, particularly apical hypertrophic cardiomyopathy, is controversial. To clarify this point, a comparative study was conducted for 57 persons with GNT (GNT+ group) and 57 persons of hypertrophic cardiomyopathy with either asymmetric septal hypertrophy or diffuse hypertrophy of the ventricular wall in the absence of GNT (GNT- group). Patients with cerebral vascular accidents, myocardial infarctions, valvular heart disease, myopericarditis, and implanted pacemakers were excluded from the study because these patients' ECGs may show GNT. Left ventriculograms were investigated at end-diastole in the right anterior oblique projection. The GNT+ group showed a spade-like configuration indicating a marked reduction in the lumen of the apical cavity in 25 cases (43.9%); a kidney or banana-like configuration indicating the inferior wall bulging into the left ventricular cavity in its mid-zone in eight cases (14.0%), and an oval configuration which indicated no deformity of the left ventricular cavity in 24 (42.1%). The spade-like configuration was also seen in four cases (7.0%) of the GNT- group. A study of ventricular wall thicknesses based on left ventriculography showed that 25.5% of cases with GNT did not have concomitant apical hypertrophy. Generally, the GNT+ group cases had a significantly thicker anterior left ventricular wall and apical hypertrophy compared to the GNT- group. The hypertrophic states of the apical wall and anterior wall of the left ventricle correlated well. The GNT+ group included a significantly larger percentage of patients who were middle aged and older than did the GNT- group, and the frequency of accompanying hypertension was significantly higher in the former. The confirmed or suspected familial occurrence of cardiomyopathy (CM) was observed in 32 cases (56.1%) of the GNT- group, and in 18 cases (31.6%) of the GNT+ group, i.e., the incidence was significantly lower in the GNT+ group. In an endomyocardial biopsy study, 40 cases (70.1%) of HCM without GNT had bizarre myocardial hypertrophy with disorganization (BMHD). The incidence of BMHD in the GNT+ group was 21/57 (36.8%)-significantly lower than in the GNT- group. In the GNT- group, there was no significant difference in the incidence of BMHD between relatively young and old patients or between patients with and without accompanying hypertension; whereas, in the GNT+ group, it was significantly lower among those with accompanying hypertension and in older patients than in those without accompanying hypertension and in younger patients.(ABSTRACT TRUNCATED AT 400 WORDS)

Adult↗
PubMed1985

Sarcoidosis of the spinal cord. Report of an autopsy case and review of the literature.

The authors report a female elderly patient with quadriplegia, hypesthesia below the neck, and rectourinary dysfunction, which were found at autopsy to have been caused by involvement of the lower cervical and upper thoracic segments of the spinal cord in systemic sarcoidosis. Sixty cases of spinal cord sarcoidosis reported in the literature are also reviewed. Most patients had clinical signs which mimicked those of a spinal cord tumor or meningomyelitis. Only in less than one-third of the cases had sarcoidosis been diagnosed before neurological symptoms occurred. Macroscopically, most intramedullary lesions formed a mass, whereas extramedullary lesions usually manifested as meningitis. Histologically, perivascular distribution of sarcoid granulomas was noted in our patient as well as in many cases reported in the literature. The clinical course of the patients with spinal sarcoidosis was usually poor when early diagnosis was not made.

Adult↗
PubMed1984

Pancreatic lithiasis in the aged. Its clinicopathology and pathogenesis.

The incidence of pancreatic calculi in autopsy material was found to increase in proportion to age after 70 yr: 0% under 69 yr of age (0 of 134), 4.2% in the 70s (5 of 119), 7.7% in the 80s (9 of 117), and 16.7% in the 90s (8 of 48). Most of the stones were found scattered throughout the peripheral ducts. Pancreatic lithiasis in the aged was clinically characterized by lack of signs and symptoms, absence of alcoholism, and was unassociated with hypercalcemia. Extensive parenchymal atrophy and fibrosis were limited to the areas upstream from the calculi. The stones were found in the ducts just above the sites of obstruction where squamous metaplasia was invariably present. Immunohistologic study showed intense staining for lactoferrin in the protein plugs and in the cytoplasm of cuboidal or squamous cells of ducts containing the plugs. Ductal stenosis, either primarily caused or secondarily exacerbated by squamous metaplasia, and lactoferrin-positive cells appeared to play a role in the pathogenesis of pancreatic lithiasis in the aged.

Age Factors↗
PubMed1982

Assay for dopamine beta-hydroxylase in rat serum and adrenal medulla by high-performance liquid chromatography with fluorescence detection.

A highly sensitive method for the assay of dopamine beta-hydroxylase in rat serum and in sample solution prepared from rat adrenal medulla is described which employs high-performance liquid chromatography with fluorescence detection. Octopamine, formed enzymatically from the substrate tyramine, is separated by Dowex 50/-X4 column chromatography and oxidized with periodate to p-hydroxybenzaldehyde, which is then converted into a fluorescent compound with 2,2'-dithiobis(1-aminonaphthalene). The derivative, after extraction with n-hexane--chloroform, is separated by normal-phase chromatography on Alox T. The limit of detection for octopamine formed enzymatically is 10 pmol. This method requires as little as 5 microliter of rat serum.

Adrenal Medulla↗
PubMed1980

Effects of fusarenon-X, a trichothecene produced by Fusarium nivale, on pregnant mice and their fetuses.

Pregnant DDD female mice received fusarenon-X, a trichothecene mycotoxin produced by Fusarium nivale, by subcutaneous infection or mixed in the diet. An abortion was induced by a single injection of 0.63 to 2.6 mg/kg body weight, with increasing frequency and shortening of the latent period corresponding to the increasing doses given. When the mice were fed with diet containing 5, 10 or 20 ppm throughout pregnancy or early phase of pregnancy, fusarenon-X inhibited embryonal implantation. Seven day-feeding during the middle phase of pregnancy was sufficient to cause abortion in 100% of dams at the concentration of 20 ppm, and at 10 ppm, in 40% of dams. Fetal body weight and length were significantly reduced by administration of the toxin, especially when it was given in the middle or late phase of pregnancy. Teratogenic effects were not apparent as the result of these studies. Direct effect of fusarenon-X on the fetuses may be the cause of embryonal deaths and stillbirths as well as growth retardation.

Abortion, Spontaneous↗
PubMed1980

Low tumor incidence in rats with long-term feeding of fusarenon-X, a cytotoxic trichothecene produced by Fusarium nivale.

In order to examine tumorigenic effects of fusarenon-X, a trichothecene compound produced by Fusarium nivale, feeding experiments on 151 male Donryu rats were carried out. Daily dose of 105 micrograms (7 ppm in the diet) or 50 micrograms (3.5 ppm)/animal of fusarenon-X was given for 1 or 2 years. Although the animals of the experimental groups showed lower body weight than controls and were more liable to be afflicted by pulmonary infections, tumor incidences were as low as that of the control group. However, several unusual tumors as follows were observed only in the experimental groups: 1 adenocarcinoma of the stomach, 2 papillary carcinomas of the urinary bladder, 1 adrenocortical adenoma, and 1 leukemia.

Animal Feed↗