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Biomedical subjects

H Toyoshima

Publications and source records attributed to H Toyoshima.

At least 163 records · Page 9Linked to original sources
PubMed1983

Renal papillary necrosis associated with Wegener's granulomatosis.

Review of the kidneys from 23 cases of Wegener's granulomatosis revealed necrosis of the renal papillae in five (21.7 per cent). These cases took a fulminant course of the disease consistent with the classic description of Wegener's granulomatosis, prevalence in the older age group, and rapid deterioration of renal function. Morphologic examination of the kidneys uniformly disclosed a variety of lesions in the blood vessels supplying the renal papilla. The most conspicuous was the widely distributed glomerular lesion represented by thrombotic and necrotic occlusion of capillary loops and crescent formation. A medullary interstitial lesion characterized by fibrinoid necrosis of the vasa recta was invariably found in the outer portion of the necrotic papilla. In addition, acute segmental and diffuse necrosis and occlusion by thrombosis were identified in the branches of spiral arteries in the adjoining papilla. The results provide an anatomic basis for the assumption that papillary ischemia due to impairment of the dual blood supply from the vasa recta and the calyceal arteries is the essential factor in papillary necrosis.

Adolescent↗
PubMed1983

Effect of LH on ovarian steroidogenesis in the mid-pregnant rat.

In order to investigate the effect of LH on the steroidogenesis of ovary in mid-pregnant rats, the ovary from day 15 pregnant rats was sliced and incubated in Krebs-Ringer bicarbonate buffer containing various kinds of materials as follows; rat LH (NIAMDD-Rat LH-RP-1, 10, 100, 1,000 ng/ml); estradiol (0.1, 1.0, 10 micrograms/ml); testosterone (0.1, 1.0, 10 micrograms/ml); dihydrotestosterone (DHT, 0.1, 1.0, 10 micrograms/ml). One thousand ng/ml of LH significantly (p less than 0.01) increased progesterone release from the ovarian tissue. LH also stimulated testosterone release. One or 10 micrograms/ml of testosterone increased progesterone release (p less than 0.01), whereas DHT caused no increase in progesterone release. These results indicated that LH could stimulate progesterone release of the ovary on day 15 of pregnant rat, by affecting the production of testosterone or estradiol.

Animals↗
PubMed1982

Effect of ventricular hypertrophy on conduction velocity of activation front in the ventricular myocardium.

To study the effect of ventricular hypertrophy on conduction velocity of the activation front noninvasively, transmural conduction indexes were obtained from findings of echocardiography and body surface potential mapping performed in 40 patients with right bundle branch block uncomplicated by the left anterior fascicular block. Because in these patients, left ventricular activation proceeds radially without being modified by right ventricular activation, the index was obtained by dividing ventricular septal thickness measured from the echocardiogram by transmural conduction time, which was taken as the time interval from the onset of the QRS complex to the time when the left ventricular epicardial breakthrough minimum appeared on the potential map. The indexes, ranging from 11 to 45 cm/s, has a good positive linear correlation with the septal thickness (Y = 2.37X - 1.33, correlation coefficient [r] = 0.83) and were abnormally small in some failed hearts. Further, both the mean ventricular activation times in lead V5 and the mean value for total duration of left ventricular activation did not differ significantly in patients with and without left ventricular hypertrophy. These findings suggest that conduction velocity was increased in the hypertrophied ventricle and decreased in the failed hearts. Because there were no significant differences in the mean serum sodium and potassium concentrations in the patients with and without left ventricular hypertrophy, it is concluded that hypertrophy itself most likely caused greater conduction velocity. Enlarged cells and multiple intercalated discs abundant in hypertrophied ventricle would have facilitated intercellular current flow and, hence, conduction velocity and impaired cellular connection in the failed heart would have reduced them. Thus, the transmural conduction index is suggested to be an important aid in interpreting electrocardiograms as well as in estimating the pathologic state of the heart.

Adolescent↗
PubMed1982

Islet-activating protein (IAP) reduces bethanechol-stimulated release of pancreatic polypeptide in the dog.

The effect of islet-activating protein (IAP) purified from culture medium of Bordetella pertussis was examined in dogs. This was assessed by the levels of pancreatic polypeptide (PP) as well as the responses of plasma insulin and glucagon to a parasympathomimetic agent, bethanechol. Plasma responses of these pancreatic hormones were measured before and 5 days after IAP injection. Although IAP had no significant effect on the bethanechol-stimulated increase in plasma glucose, insulin and glucagon, the PP response to bethanechol was significantly reduced after IAP treatment compared with that before IAP (p less than 0.05). In conclusion, IAP significantly and selectively reduced bethanechol-stimulated PP release in the dog although the mechanism remained to be elucidated.

Animals↗
PubMed1982

Impaired response of human pancreatic polypeptide to insulin-induced hypoglycemia in chronic pancreatitis without diabetes mellitus.

In order to clarify the pancreatic endocrine functions in mild chronic pancreatitis, the response of insulin to oral glucose load and the response of glucagon and human pancreatic polypeptide (HPP) to insulin-induced hypoglycemia were investigated in five normal controls and eight patients with chronic pancreatitis but without diabetes mellitus. Although insulin and glucagon responses in patients with chronic pancreatitis tended to be lower than those in normal subjects, the differences between the two groups were not statistically significant. In contrast, HPP response to hypoglycemia in the patients was markedly impaired and significantly lower than that in normals (p less than 0.02). This finding indicates that the impairment of HP response is the earliest and most definite manifestation among pancreatic endocrine abnormalities in chronic pancreatitis.

Adult↗
PubMed1982

Various phenotypes of diabetes mellitus at ultimate outcome of acutely developed diabetic state induced by viral infection.

For 4 to 8 years we followed up 3 diabetic patients in whom the onset of diabetes seemed to be closely related to the well-documented Epstein-Barr virus infection (Case 1) or Coxsackie B4 virus infection (Case 2, 3). Although all developed acute ketosis-prone diabetes in the convalescent stage of the viral infections, the subsequent clinical courses were quite different from each other. Case 1 has remained consistently insulin-dependent and associated with positive islet cell antibody, gastric parietal cell antibody, thyroglobulin hemoagglutinating antibody and thyroidal microsomal hemoagglutinating antibody. Case 2 restored normal glucose tolerance. Case 3 has become noninsulin-dependent diabetes mellitus after a 6 year interval. Thus, it is reasonably presumed that virus could be responsible for the occurrence of different phenotypes of diabetes.

Acute Disease↗
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

[The double contrast hysterography using CO2 insufflation (author's transl)].

The double contrast hysterography, which was performed by the continuous CO2 insufflation with the ordinary HSG, was applied to 162 infertile patients. Forty-nine of 162 patients showed the abnormal findings by this method. Hysteroscopic or histological examinations revealed that 26 of these patients had hyperplasia, 15 had polyp, 2 had myoma and 1 had intrauterine foreign body. When these results were compared with those obtained by ordinary HSG, it was found that the double contrast hysterography would be more useful to investigate the detailed intrauterine changes such as hyperplasia or polyp than the ordinary HSG, and, therefore, would be a useful aid in the clinical care.

Carbon Dioxide↗
PubMed1982

Therapeutic effect of intra-articular injection of high molecular weight hyaluronic acid on osteoarthritis of the knee.

Intra-articular injections of high molecular hyaluronic acid (1% solution) were given at 1- or 2-week intervals to 43 patients with osteoarthritis of the knee. Of the 45 treated knees, 32 (71%) responded favorably. This therapy was effective if the osteoarthritis was of a grade less than moderate; it was not effective in cases with considerable effusion or in those with gross architectural changes. No serious side effects were encountered. We suggest that the beneficial effects of hyaluronic acid may be attributable to improved lubrication of the affected joint, to normalization of synovial fluid production by the action of hyaluronic acid on synovial tissue, and/or to the improvement of the intra-articular environment by the contribution of hyaluronic acid to the rebuilding of the barrier that protects the synovial membrane and articular surface.

Adult↗
PubMed1981

Intracytoplasmic granules of the inner medulla and papilla of the potassium depleted human kidney.

Morphological changes were studied in the kidney of a potassium depleted 21-year old Japanese male with Bartter's syndrome. Characteristic features were PAS-positive intracytoplasmic granules in the inner medulla and the papilla. The intracytoplasmic granules were conspicuous towards the papillary tip and ultrastructurally composed of small vesicles, vacuoles, amorphous dense materials, lamellar contents and myelin like figures, and bounded by a single limiting membrane. The granules in this human kidney were, with regard to their distribution and ultrastructural findings, similar to those in the kidney of experimentally potassium depleted rats. The results indicate that the intracytoplasmic granules in the renal inner medulla and the papilla are the characteristic feature of the potassium depleted human kidney and a counterpart to those in the potassium depleted rat.

Adult↗
PubMed1981

Sequences of early and late phases of repolarization on dog ventricular epicardium.

Monophasic action potentials from 32 to 43 epicardial sites were recorded with concentric suction electrodes in 11 dogs during atrial pacing at a constant rate. The duration of action potentials and the sequence of repolarization referenced to the onset of ventricular activation at 50% of the highest plateau amplitude and the end of the action potential were determined. These quantities were correlated with activation sequence determined from action potential upstrokes. On the anterior ventricular surface, both 50% and 100% repolarization sequences were qualitatively similar to activation sequence and showed positive correlation coefficients. On the posterior ventricular surface, 50% and 100% repolarization sequences had little qualitative resemblance to activation sequence and showed lower correlation coefficients. Correlations between the patterns of 100% repolarization and action potential duration were significantly higher on the posterior than the anterior ventricular surface. These findings demonstrate that activation sequence has less influence on repolarization sequence on the posterior than the anterior wall and that action potential duration is the major determinant of repolarization sequence on the posterior wall. These findings extend previous descriptions of the normal sequence of ventricular repolarization and the relative roles of activation and action potential duration in determining that sequence. The study also showed differences between the sequences of 50% and 100% repolarization suggesting different slopes of action potential downstrokes at various ventricular sites with steeper slopes at the posterior basal and upper anterolateral left ventricular wall. This finding adds new detail to previous descriptions of the distribution of intrinsic ventricular recovery properties.

Action Potentials↗
PubMed1981

A study on the transmural conduction velocity of activation front in the left ventricle of RBBB patients.

To investigate the effect of ventricular hypertrophy on the conduction velocity, the transmural conduction velocity was obtained from the findings of echocardiographic, and body surface potential mapping examinations on 20 RBBB patients. The transmural conduction velocity was linearly correlated with the ventricular septal thickness and the greater the thickness, the faster was the conduction velocity. There was no statistically significant difference in the duration of the left ventricular activation obtained from the mapping examinations as well as in the time of onset of intrinsicoid deflection in V5 between the group of left ventricular hypertrophy and that of non-hypertrophy. There was a good linear correlation between the imaginary distance covered by the activation front which proceeded in the direction from endocardium to epicardium during the left ventricular activation and the ventricular septal thickness. These findings were explicable from the faster conduction velocity in the hypertrophied ventricle. The increase in the conduction velocity in the hypertrophy group would be due to cable characteristics of hypertrophied cardiac cells and also due to increase in the number of multiple intercalated discs in the hypertrophied ventricle. It was concluded that the conduction velocity would be an important information to interpret the ECGs in ventricular hypertrophy as well as to estimate the pathological state of the heart.

Bundle-Branch Block↗