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Biomedical subjects

H Miyajima

Publications and source records attributed to H Miyajima.

At least 127 records · Page 7Linked to original sources
PubMed1983

Three families with hereditary hemolytic anemia and pyrimidine 5'-nucleotidase deficiency: electrophoretic and kinetic studies.

Three new variants of pyrimidine 5'-nucleotidase (P5N) found in Japan were studied. They are characterized by slow electrophoretic mobility and a high Michaelis constant for cytidine 5'-monophosphate as has been described in previously reported cases, but are unique with respect to the thermostability test and in pH optima. P5N Kumamoto was thermostable and showed a markedly basic shift in the pH optimum. P5N Nagano was thermolabile and had a normal pH optimum. P5N Kurume was thermostable and showed a basic shift in the pH optimum. These data suggest that these variants have structural gene mutations and that they are clearly distinguished from previously reported cases.

5'-Nucleotidase↗
PubMed1982

Protective effect of inactivated virus vaccine on Sendai virus infection in rats.

Rats which had received two doses of inactivated Sendai virus vaccine were resistant to intranasal virus challenge. Vaccination was equally effective when administered by intravenous, intraperitoneal, intramuscular, or subcutaneous routes but not the intranasal route. Rats vaccinated intraperitoneally with inactivated Sendai virus vaccine were protected from contact infection. Suckling rats born to vaccinated dams were resistant to challenge infection at 3 weeks of age, but the resistance was not demonstrated after weaning at 4 weeks of age.

Animals↗
PubMed1981

[Antibody production in rats vaccinated with inactivated Sendai virus (author's transl)].

Adult male and female rats were inoculated with tween 80-ethylether-formalin-ultraviolet inactivated Sendai virus (Sv-V) and examined for the production of hemagglutination inhibition (HI) antibody. There were no significant differences in the antibody titers between males and females, and among the various routes of inoculation except for the intranasal which was not effective. The antibody became detectable 7 days after a single inoculation with 10(5) HAU of Sv-V. The antibody titer, which had its peak 21 days after the inoculation, persisted for 200 days and declined gradually thereafter. The HI antibody titers were correlated with inoculated Sv-V doses and a predominant booster reaction with the vaccine was observed. Maternal antibodies were detected in sucklings born to dams hyperimmunized with the vaccine. The titers were similar to those of the dams until 3 weeks after birth but declined rapidly after weaning at 4-week-old. The titers of fetuses and neonates before suckling were significantly lower than those of the sucklings.

Animals↗
PubMed1980

Modification of haloalkane-induced hepatotoxicity by exogenous ketones and metabolic ketosis.

A variety of chemicals potentiate haloalkane-induced liver injury, but structure-activity relationships are not apparent. Recent studies have shown that one structural determinant, a carbonyl moiety, is common to several potentiating agents. Thus five ketonic chemicals (acetone, 2-butanone, methyl n-butylketone, 2,5-hexanedione, Kepone) and three chemicals that are metabolized to ketones (isopropranol, 2-butanol, n-hexane) potentiate the liver injury produced by one or more haloalkanes. Potentiation also has been observed when haloalkanes are administered to animals in a state of metabolic ketosis produced by alloxan-induced diabetes or by 1,3-butanediol administration. These observations are consistent with the hypothesis that administration or generation of ketonic substances increases the susceptibility of the liver to the toxic actions of haloalkanes.

Acidosis↗
PubMed1978

Ultrastructural changes of human sural nerves in the neuropathy induced by intrauterine methylmercury poisoning (so-called fetal Minamata disease).

Biopsy of the sural nerve was performed on three patients with severe Minamata disease of more than 10 years duration. There were so many unmyelinated and poorly myelinated nerve fibers that myelinated fibers scattered irregularly in small numbers or in groups of peculiar features in the intraneural bundle. Abnormaly thin or poorly formed myelin sheaths were noticed. Incomplete myelination and abnormal myelination varied in size and shape appeared as fetal anomaly. Regenerated axons extremely small in size remained singly or in groups following regenerative sprouting. Sometimes, extremely small axons with normal myelination were noticeable, while the axons were lost, leaving myelin sheaths. Axons occasionally contained increased neurofilaments. Schwann cells were not so increased as in adult Minamata disease. Degenerative changes of nerve fibers still proceeded, presumably because the patients lived in the mercury-contaminated district. Myelin degenerations and glycogen deposits in the axoplasm were identified.

Adolescent↗
PubMed1977

Serum and tissue lipids and glomerulonephritis in the spontaneously hypercholesterolemic (SHC) rat, with a note on the effects of gonadectomy.

A spontaneously hypercholesterolemic male rat, found in the Sprague-Dawley strain, was mated with normocholesterolemic females of the same strain: the male offspring were hypercholesterolemic. By selecting rats according to their plasma cholesterol levels and repeated brother-sister mating, progeny became progressively more hypercholesterolemic--especially the males--when fed a basal low-cholesterol diet. These rats were tentatively given the short name of SHC and have at present been bred to the F14 generation. Hypercholesterolemia in male SHC rats proceeded in two stages: plasma cholesterol rose only slightly during the first stage up to the age of about 10 weeks and then increased progressively in the subsequent stage. Female SHC rats developed a high degree of hypercholesterolemia from the age of 10 months. SHC rats maintained on the basal diet were not obese, but their kidneys and livers enlarged. Histological examination showed that glomerulonephritis developed in the kidney of male SHC rats by the age of 9 months. The liver of these rats was not fatty and contained rather less lipid than usually found in the normal Sprague-Dawley rat. Male and female SHC rats were subjected to gonadectomy at the age of 4 weeks, and were then maintained on the basal diet for 18 weeks. Blood cholesterol was higher throughout the experiment in ovariectomized female SHC rats than in controls, and the renal lesion was correspondingly worse. However, gonadectomy in male SHC rats had no effect on the disease.

Aging↗
PubMed1977

Enhancement of tumor induction in rats with Moloney murine sarcoma virus by a "new" method based on direct injection into fetuses.

Undiluted, fivefold-diluted, and 25-fold-diluted doses of a stock of Moloney murine sarcoma virus were injected directly, in a volume of 0.025 ml, into the backs of fetal Sprague-Dawley rats by laparotomy through the uterine wall at 18 days of gestation. During the first 8 weeks after birth the young responded to the virus with remarkably high but dose-dependent incidences of neoplasms. When a one-fifth dilution of the virus preparation was inoculated at fetal ages 16, 18, and 20 days, the incidences of lesions decreased with advancing fetal age. The tumors developed preferentially at the virus inoculation site and/or in the proximal parts of the extremeties; all were considered to be of mesenchymal derivation, i.e., malignant mesenchymoma, rhabdomyosarcoma, osteosarcoma, fibrosarcoma or fibromyxosarcoma, hemangiosarcoma, plasmacytoma, and a giant cell tumor. This injection procedure provided us with a valuable experimental tool for the rapid screening or testing of potential chemical carcinogens and other biologic studies.

Animals↗
PubMed1977

Pathology of neoplasms and other lesions induced in rats with Moloney murine sarcoma virus.

Moloney murine sarcoma virus (M-MSV) was injected directly into the fetuses of Sprague-Dawley rats during the late stage of gestation and into the neonates within 24 hours after birth. Ninety rats developed 188 neoplastic lesions during the 8-week period of observation. Nearly all of the neoplasms were of mesenchymal derivation. Sixty percent of these neoplasms revealed more complex histologic features than those previously reported for neoplasms induced in rodents with M-MSV and were designated "malignant mesenchymoma" which developed preferentially in the proximal parts of the extremities, distant from the inoculation site. Rhabdomyosarcoma and osteosarcoma which developed in a pure form at the various sites were the next most common tumor type. Osteosarcoma developing in a pure form and as a component of malignant mesenchymoma in the humerus and femur was comparable to that of juxtacortical osteosarcoma of man; The development of excessive bones were observed in the forelimb and/or hind leg, suggesting a type of skeletal malformation. The reaction to M-MSV merits attention as a model for the study of an osteosarcoma and malignant mesenchymoma as well as rhabdomyosarcoma and also for the study of viral teratogenesis in man, as "rubella syndrome".

Animals↗
PubMed1975

Intracellular localization and size of glycogen particles in glycogen synthesized under histochemical conditions.

During the investigation of the histochemical synthesis of glycogen particles from glucose 1-phosphate by the phosphorylase-branching glycosyltransferase system in various tissue cells, it was observed that focal synthesis localized in a certain area of the cytoplasm occurred in some cells. This differed from the usual synthesis in which particles of similar size were synthesized within the cytoplasm. Otherwise, cytoplasmic particles of various size were also synthesized in other cells under the same histochemical condition. The possible significance of the presence of these patterns in glycogen synthesis is discussed.

Animals↗