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Biomedical subjects

A Miyazaki

Publications and source records attributed to A Miyazaki.

At least 235 records · Page 13Linked to original sources
PubMed1986

Demonstration of islet cell surface antibodies in sera of New Zealand black mice and inhibitory effect on insulin release.

Islet cell surface antibodies (ICSAs) in sera of New Zealand Black (NZB) and New Zealand White (NZW) mice were detected by the indirect immunofluorescence method with cultured Balb/c mouse islet cells as antigens. Circulating ICSAs appeared in NZB mice from age 20 wk; at 30 wk, 73% of male mice and 88% of female mice had detectable ICSAs. The ICSAs were significantly absorbed with mouse islet cells but hardly absorbed with spleen cells or liver powder. The ICSAs also bound with islet cells of ICR mice, Sprague-Dawley rats, and NZB mice. NZB mice showed glucose intolerance especially at ages 10 and 30 wk. Although plasma glucose levels tended to be higher in NZB mice with strongly positive ICSAs, pancreatic insulin content was not reduced, and insulitis was rarely observed in the pancreases. On the other hand, 30-wk-old NZW mice had normal or mildly impaired glucose tolerance and only weak, if any, ICSAs. The ICSA-positive serum of NZB mice significantly suppressed glucose-induced insulin release by cultured islet cells. The ICSAs may be responsible, at least in part, for glucose intolerance in NZB mice after age 20 wk through the inhibitory effect on insulin secretion.

Age Factors↗
PubMed1985

Nicotinamide prevents lymphocytic infiltration in submandibular glands but not the appearance of anti-salivary duct antibodies in non-obese diabetic (NOD) mice.

Previously we have shown that nicotinamide prevents spontaneously occurring diabetes associated with insulitis in non-obese diabetic (NOD) mice. In this study we injected nicotinamide (0.5 mg/g) or saline (0.01 ml/g) into female NOD mice daily during a period between 4 and 16 weeks of age. At the end of the treatment, periductal and perivascular lymphocytic infiltration in submandibular glands was observed in 91% of saline-injected control mice and 36% of nicotinamide-injected mice (P less than 0.01). No significant difference was observed in the prevalence of anti-salivary duct antibodies or antinuclear antibodies between the nicotinamide group and the saline group. Nicotinamide may alter cell-mediated, but not humoral, immunity to salivary gland cells, resulting in the prevention of submandibulitis.

Animals↗
PubMed1985

Predominance of T lymphocytes in pancreatic islets and spleen of pre-diabetic non-obese diabetic (NOD) mice: a longitudinal study.

We examined sequential changes in the subsets of mononuclear cells infiltrating the pancreatic islets and splenic lymphocytes in pre-diabetic non-obese diabetic (NOD) mice, an animal model for type I diabetes, using immunofluorescent techniques. In the pancreas, a predominant infiltration by activated T lymphocytes, including helper inducer and cytotoxic suppressor T cells, was observed in the early stage of insulitis. Natural killer cells were also detected in the lesions. Immunoglobulin bearing cells tended to increase in number with the progression of insulitis. T lymphocytes were localized close to islet cells, while immunoglobulin bearing cells appeared adjacent to blood vessels and around T cell clusters. Immunoglobulin deposition or Ia expression on islet cells was not observed. The percentage of splenic T lymphocytes was markedly increased in the initial stage of insulitis as compared with control ICR mice and this elevated proportion of T cells continued throughout the observation period. As for splenic T cell subsets, cytotoxic suppressor T cells were increased in NOD mice. These results suggest that T lymphocytes play an important role in the initiation of insulitis long before the onset of overt diabetes. Moreover, NOD mice seem to have characteristic immunological features different from the BB rat or a reported case with human type I diabetes.

Animals↗
PubMed1985

Decreased incidence of diabetes mellitus by monosodium glutamate in the non-obese diabetic (NOD) mouse.

Subcutaneous administration of monosodium glutamate (MSG) to neonatal female non-obese diabetic (NOD) mice resulted in obesity associated with stunting and hyperinsulinemia. However, the cumulative incidence of diabetes mellitus at 25 weeks of age in the MSG group was significantly lower than in the control group (10.3% vs. 43.6%, P less than 0.005). The immunoreactive insulin content of the pancreas from the 13- to 20-week-old MSG-treated mice was higher than that of the control mice (P less than 0.005). Immunohistochemistry showed that the number of pancreatic B-cells was well preserved and insulitis was attenuated in the MSG-treated mice. Plasma corticosterone and 3, 5, 3'-triiodothyronine levels were elevated in the MSG group. These results suggested that, by the MSG treatment, the B-cell functions were maintained through the modification of the degenerative process of the islets in the NOD mouse.

Aging↗
PubMed1982

Preventive and therapeutic effects of large-dose nicotinamide injections on diabetes associated with insulitis. An observation in nonobese diabetic (NOD) mice.

This experiment was undertaken to explore a novel method of therapy for insulin-dependent diabetes mellitus (IDDM), using nonobese diabetic (NOD) mice that had symptoms and histologic changes similar to those of human IDDM patients. We examined preventive and therapeutic effects of large-dose nicotinamide administration on diabetes in NOD mice. Eighteen young female NOD mice without glycosuria were randomly divided into two groups; nine received subcutaneous nicotinamide (0.5 mg/g body wt) injections every day and the other nine were maintained as a control group and not injected. After 40 days, all of the mice given nicotinamide showed almost normal glucose tolerance and only mild insulitis on histologic study. On the other hand, marked glycosuria and severe insulitis were observed in six of the nine mice not injected. Four of six NOD mice given nicotinamide from the day of the first occurrence of marked glycosuria displayed a disappearance of glycosuria and an improvement in glucose tolerance during the therapy; however, urine sugar became negative in only one of six mice that received nicotinamide from 1 to 2 wk after the onset of marked glycosuria. These results indicate that nicotinamide has preventive and therapeutic effects on diabetes in NOD mice, and suggest the reversibility of B-cell damage, at least at a very early stage of IDDM.

Animals↗
PubMed1982

[Amyl nitrite test in the evaluation of left ventricular function: application to ischemic heart disease and Duchenne's progressive muscular dystrophy].

The effect of amyl nitrite (AN) inhalation on the left ventricular function was evaluated by mechanocardiography and echocardiography. The patient's group consisted of 110 cases with ischemic heart disease (IHD) and 25 cases of dystrophia musculorum progressiva (DMP) of Duchenne type. The former was a representative of impairment of blood supply and myocardial involvement, and the latter was of predominant myocardial disease. The control was age-matched 32 normals for IHD group and 17 cases for DMP group. Left ventricular function was mainly evaluated by systolic time intervals (STI) and the echocardiographic correlates. Fifty-five cases of IHD group were tested by coronary angiography and left ventriculography and these data were compared with the noninvasive measures. The results were as follows: I. IHD group: The ratio of ejection time (ET) to pre-ejection period (PEP), ET/PEP, did not change so much as in controls after AN inhalation, and this percent change was much smaller in cases with lesions of the left anterior descending artery (LAD) than in cases with lesions of the right coronary artery (RCA). On the other hand, mean posterior wall velocity (mPWV) and posterior wall excursion (PWE) changed greater in patients with LAD lesion than in those with RCA lesion. In cases with LAD stenosis, percent change in ET/PEP was smaller in cases with asynergy than in cases without it, disclosing more significant impairment of the left ventricle in the former. II. DMP group: In severe cases, ET/PEP was small even at rest, and percent change by AN inhalation was smaller than control in mild cases and smallest in severe cases. This seems to be useful in evaluating the severity of the diseased process. The mPWV and PWE showed impairment of left ventricular motion even at rest, but it was clearly showed in severe cases after AN inhalation. These results indicate that impairment of left ventricular function induces the poor response to AN inhalation and this, in turn, results in the lack of hyperactivity of the heart produced by this drug.

Adolescent↗
PubMed1982

[Estimation of infarct size with 201Tl by multiprojection analysis].

Since mortality resulting from cardiac arrhythmia has been decreased by an introduction of CCU, power failure has become the major cause of death in patients with acute myocardial infarction. The power failure is assumed to be related to an infarct size. Therefore, noninvasive quantification of the infarct size is required for proper assessment of prognosis and treatment. Recently, a scintigraphic technique using radionuclide thallium-201 has developed, which is accumulated not in myocardial necrosis but in the intact myocardium. In this study, we tested two different parameters expressing the infarct size based on 5-projection myocardial scintigrams. One parameter is the ratio of the defect area to the total myocardium (% area), and the other is the ratio of a count decrease by the defect to total counts (% loss counts) in the planar image. Each parameter was obtained from uni- and multi-projection analysis. Six items were selected in the study including % area of 1-projection analysis, % area of 3-projection analysis, % area of 5-projection analysis, % loss counts of 1-projection analysis, % loss counts of 3-projection analysis, and % loss counts of 5-projection analysis. In 56 patients with the first attack of acute myocardial infarction, these parameters showed a clinically acceptable correlation with ejection fractions obtained by contrast ventriculography performed about 4 weeks later, with pulmonary end-diastolic pressure shortly after the onset, and with peak-CPK and sigma CPK obtained by 4 or 6 hourly measurements. Correlation coefficients between two parameters among 6 items showed no difference from each other. Scintigraphy was performed more than twice in 11 patients and the infarct size of these patients was decreased with the clinical course. Validity for estimates of the infarct size obtained with two parameters (% loss counts and % area) in different projection analysis was examined by a phantom model experiment and the clinical implications were discussed. In conclusion, an infarct size estimated by 201Tl scintigraphy provides useful informations about the size of necrosis and cardiac function in patients with acute myocardial infarction.

Adult↗
PubMed1979

Ossification of the posterior longitudianl ligament of the cervical spine: subtotal vertebrectomy as a treatment.

If the ossification is localized in the central part of the intervertebral space, anterior decompression surgery of Cloward may be indicated. However, if most posterior ligamentous ossification covers the posterior surface of the vertebral body and the lateral sides, Cloward's method is not indicated. We have developed a method of anterior decompression and fusion surgery to clear the ossified area, resecting the vertebral body (subtotal vertebrectomy). The results were excellent in 3 of 4 patients with preoperative radiculopathy; there were 2 excellent and 16 good results in 22 patients with myelopathy. Of course laminectomy can produce some good effects, but the anterior obstruction removes through the anterior approach. Anterior decompression may be indicated when ossification is localized below the C3--4 intervertebral space, and when the spinal canal is not narrowed in the upper cervical region, even if ossification extends over the whole cervical spine. Laminectomy is advised when ossification involves all levels of the cervical spine, the upper cervical spine is narrowed or the sagittal dimension of the spinal canal is reduced more than 60%.

Cervical Vertebrae↗
PubMed1968

[Spina bifida].

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Child, Preschool↗
PubMedDate not supplied

Immunocytochemical detection of desmin in fat-storing cells (Ito cells).

Desmin is a smooth muscle protein consisting of intermediate filaments. It is also present in other cell types. We obtained desmin antibodies from New Zealand white rabbits which were immunized with desmin following its extraction from chicken gizzard smooth muscle. By immunocytochemical methods, the antibody stained the Z-line of rat skeletal myofibrils and produced only one band with chicken gizzard desmin by immunoblotting. The antibody was specific for desmin, but was not tissue-specific. Wistar rat liver was studied by indirect immunoperoxidase and immunofluorescent methods using the antibody. Cells which reacted were diffusely distributed in the hepatic lobule, had stellate shape, bore elongated cytoplasmic extensions and contained few fat droplets. The fat droplets increased in size and amount after administration of vitamin A, and contained vitamin A as determined by ultraviolet exposure and gold impregnation. The fat-containing cells did not phagocytose carbon particles after injection of colloidal carbon and were, therefore, classified as fat-storing cells (Ito cells).

Animals↗
PubMedDate not supplied

Successful thrombolytic therapy using tissue-type plasminogen activator in Kawasaki disease.

Thrombolytic therapy using tissue-type plasminogen activator was performed in a 7-month-old boy with massive mural thrombi in large coronary aneurysms due to Kawasaki disease. Magnetic resonance imaging successfully demonstrated mural thrombi in both proximal and distal coronary aneurysms and their disappearance after thrombolytic therapy. We conclude that for preventing acute myocardial infarction and sudden death intravenous and intracoronary thrombolytic therapy with tissue-type plasminogen activator may help in infants and children with Kawasaki disease who have thrombi in coronary aneurysms.

Coronary Aneurysm↗
PubMedDate not supplied

Aneurysmal change of the ductus arteriosus after prostaglandin E1 administration for pulmonary atresia: demonstration with magnetic resonance imaging.

We report a case of pulmonary atresia in which the ductus arteriosus underwent aneurysmal dilatation after infusion of prostaglandin E1 incorporated in lipid microspheres. To our knowledge this is the first case in which this rare morphological change has been demonstrated with the noninvasive method of magnetic resonance imaging.

Alprostadil↗