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Biomedical subjects

M Utsuyama

Publications and source records attributed to M Utsuyama.

80 records · Page 5Linked to original sources
PubMed1984

Lung changes resulting from intraperitoneal injections of porcine pancreatic elastase in suckling rats.

We administered 1 mg of purified porcine elastase per 100 g body weight intraperitoneally twice weekly to male rats during the first 4 wk of life. This altered the structure of the lungs so that the proportion of alveolar duct air (the "core" of air internal to the mouths of alveoli in alveolar ducts) increased and the proportion of alveolar air decreased. The alveolar surface-to-volume ratio was decreased, and the lungs had too few alveoli. The lungs were also hyperexpandable, containing more air and saline per gram of lung tissue. No biochemical alterations were noted in elastin or collagen content in elastase-treated animals. In a separate experiment, we showed that elastaselike activity appears in the blood 1 h after intraperitoneal injection of elastase and, although low, was still significantly raised 24 h after injection. We feel that elastase has interfered with lung growth and alveolar development by altering mainly the elastin in the collagen-elastin network. Intraperitoneal elastase injection at the time of active elastin synthesis and alveolar multiplication may be a suitable model to test the hypothesis that lungs injured in infancy may be more susceptible to damage in later life.

Animal Population Groups↗
PubMed1983

Element analysis of Lewy and adrenal bodies in Parkinson's disease by electron probe microanalysis.

Two possible interpretations of the origin of Lewy bodies and adrenal bodies found in Parkinson's disease are now under discussion: a disorder of (1) catecholamine metabolism or (2) sphingomyelin lipidosis. From the electron probe microanalysis of Lewy bodies and adrenal bodies, we find that the Lewy body contains sulfur, calcium, and phosphorus, and the adrenal body also contains these three elements. Furthermore, a positive correlation was obtained between the X-ray intensity of the sulfur and the diameter of adrenal body. For Lewy bodies, this correlation was not obtained. The results suggest that a common mechanism may exist for the production of Lewy and adrenal bodies, although they differ somewhat in their accumulation of sulfur. It is considered that both structures may originate, in part, from degenerated protein containing sulfur.

Adrenal Glands↗
PubMed1983

Changes in lung morphologic features and elasticity caused by streptozotocin-induced diabetes mellitus in growing rats.

Pressure-volume characteristics and morphologic changes were investigated in lungs of growing rats with streptozotocin-induced diabetes mellitus. Lung elastic recoil examined with quasi-static, air-filled pressure-volume curves showed no significant differences from that in control rats at all lung volumes. No alterations of surfactant properties as measured by a surface balance were observed. A 24% increase in the volume proportion of alveolar wall was found in the lungs from diabetic rats. There was an increase in the relative amounts of collagen, elastin, and basal laminae in the alveolar wall. There were more alveoli per unit volume in the diabetic animals (49.12 X 10(5)) than in the control animals (39.80 X 10(5)) (p less than 0.05) and there was an increase in the surface-to-volume ratio of the lungs of the diabetic rats.

Animals↗
PubMedDate not supplied

Lung growth in rats subsequent to administration of intraperitoneal elastase during the first 4 weeks of life.

Male rats received intraperitoneal injections of porcine pancreatic elastase twice weekly during the first 4 weeks of life. Saline-injected male rats served as controls. After a 4-week recovery period, the rats were sacrificed, and the excised lungs were studied using saline- and air-filled volume-pressure curves, morphology, and biochemistry. Both air- and saline-filled volume-pressure curves showed loss of elastic recoil in the elastase-treated animals. In elastase-treated animals the mean linear intercept was increased, the numbers of alveoli per unit area, per unit volume, and per lung decreased, and alveolar surface area decreased. These animals also showed a disproportionate increase of alveolar duct air at the expense of the proportion of alveolar air. Morphometric differences between the elastase-treated animals and the controls were somewhat smaller in this experiment than in a previous one in which the animals were sacrificed immediately after 4 weeks of intraperitoneal elastase. We attribute this difference to alveolar multiplication between 4 and 8 weeks of age. However, evidence is presented that these alveoli were abnormal. Loss of recoil properties was more evident after the 4-week recovery period than at the termination of elastase administration, suggesting that the newly formed alveoli were functionally abnormal. Collagen content was increased in the elastase group, but elastin was significantly decreased. This may be a good elastase model for assessing the hypothesis that lungs minimally damaged in infancy may have an increased susceptibility to environmental damage in later life.

Animals↗
PubMedDate not supplied

Immunological alterations with aging-laying a stress on recent progress in Japan.

Age-related decline of immune functions mainly occurs in the T-cell-dependent immune system and this is precede by physiological thymic involution starting after puberty. Age-related alterations of T cells are seen in their number, subsets and qualities. In relation to the qualitative change of aging T cells, disturbance of intracellular signal transduction is responsible for the impairment of proliferation and cytokine production upon antigenic stimulation. Thymus, but not bone marrow, is responsible for aging of the T-cell-dependent immune system. The thymic capacity to induce T cells starts to decline early in life. Older thymus induces different subsets of T cells which are functionally less active T cells than those of young thymus. In association with a decline in immune functions to exogenous antigens, autoimmune phenomena increase with advance of age, which are observed as production of autoantibodies and auto-reactive T cells. The possible site for controlling thymic function is discussed.

Journal Article↗
PubMedDate not supplied

Induction of immunological tolerance by oral, but not intravenous and intraportal, administration of ovalbumin and the difference between young and old mice.

BACKGROUND: Induction of immunological tolerance is dependent on the route of antigenic administration, the dose of an antigen and the age of animals. OBJECTIVES: We investigated the effect of age on the tolerance induction in mice by administration of antigen through different routes and at different doses. DESIGN: Young and old BDF1 mice were orally, intraportally or intravenously administrated with a low or a high dose of ovalbumin (OVA). Then, delayed-type hypersensitivity (DTH) responses and serum anti-OVA antibody levels were assessed after systemic immunization of OVA with alum after appropriate intervals. RESULTS: In the young mice, oral administration of OVA suppressed DTH response and anti-OVA IgG1, IgG2b, IgM and IgE level in a dose-dependent manner. In the old mice, however, the suppression of IgG1 and IgE levels was induced by oral administration of a low dose of OVA, but no suppression by a high dose. On the other hand, intraportal or intravenous injection of OVA did not suppress DTH response and enhanced anti-OVA antibody levels in a dose-dependent manner in both young and old mice. Production of anti-OVA IgG2a antibody after systemic injection of OVA was detected in the mice, which had been treated with intraportal or intravenous injection of OVA, but not detected in the mice, which had been treated with oral administration of OVA. On the contrary, suppression of anti-OVA IgE antibody was observed only in the mice, which had been treated with oral administration of OVA. CONCLUSION: The oral administration of OVA, neither intravenous nor intraportal, induced immunological tolerance to OVA. An adequate dose of OVA for the tolerance induction and the suppression of antibody production are different between young and old mice. The suppression of IgE antibody was observed only by oral administration of OVA, much obviously in young mice than in the old. The results also indicated that the antigen processing in the liver did not play a major role in the induction of oral tolerance to OVA.

Administration, Oral↗