Search PubMed⌕ Search

Biomedical subjects

H Ohsawa

Publications and source records attributed to H Ohsawa.

At least 55 records · Page 3Linked to original sources
PubMed1993

[Evaluation of myocardial viability in the infarcted areas by the improved myocardial perfusion after percutaneous transluminal coronary angioplasty].

Muscle viability in infarcted areas was evaluated based on the relationship between Tl myocardial scintigraphic findings and improvements in myocardial perfusion after percutaneous transluminal coronary angioplasty (PTCA) in 110 patients with old myocardial infarction (OMI). 1. Myocardial perfusion was improved in 95% of patients with redistribution in infarcted areas before PTCA, but in only 29% of patients without redistribution before PTCA. 2. The %Tl-uptake and the washout rate were significantly improved after PTCA in all patients with redistribution before PTCA with normal to dyskinesia of segmental wall motion. The %Tl-uptake of infarcted area after PTCA was greater than 50% in all patients. 3. The %Tl-uptake and the washout rate were significantly improved after PTCA in patients without redistribution before PTCA. However, the %Tl-uptake was not changed after PTCA in such patients with akinesia or dyskinesia of segmental wall motion. 4. Myocardial perfusion was improved late during prolonged follow-up after PTCA in 40% of patients without restenosis. Stunning of the myocardium is likely in these patients. 5. %Tl-uptake of more over 50% in patients with or without redistribution before PTCA indicates the presence of muscle viability. Muscle viability cannot be expected in the infarcted areas of patients without redistribution showing akinesia or dyskinesia of segmental wall motion. Patients without redistribution before PTCA include cases with underestimated ischemic lesion. The diagnosis of muscle viability by single photon emission computed tomography will be improved by including evaluation of segmental wall motion by echocardiography.

Aged↗
PubMed1992

Islet amyloid polypeptide-derived amyloid deposition increases along with the duration of type 2 diabetes mellitus.

To investigate the involvement of islet amyloid polypeptide (IAPP) and amyloid deposits in the pathophysiology of this disease, we studied the relationship between IAPP-derived amyloid deposition and the clinical features in type 2 diabetes mellitus. We examined pancreata obtained from 37 type 2 diabetic subjects and 12 non-diabetic ones by immunohistochemical techniques using two specific antibodies to IAPP. IAPP-derived deposits occurred in 1 of the 12 (8.3%) non-diabetic subjects and 28 of the 37 (75.7%) diabetics. When diabetic patients were divided into categories according to the presence of the deposits, the duration of the disease was significantly longer in patients with amyloid than that in the patients without it. The odds ratio of type 2 diabetes mellitus of at least 14-years-duration to the deposition was significantly high, and a body weight of at least 120% maximal ideal body weight was relatively high. In conclusion, IAPP-derived amyloid deposition increases along with the duration of type 2 diabetes mellitus and obesity may further enhance these deposits, hence hypersecretion of IAPP may be involved in the progression of this disease.

Aged↗
PubMed1992

Hypersecretion of IAPP from the islets of VMH-lesioned rats and obese Zucker rats.

To investigate the possible role of islet amyloid polypeptide (IAPP) in the development of type 2 diabetes mellitus, we examined the IAPP content and secretion in pancreatic islets isolated from ventromedial hypothalamic (VMH)-lesioned rats and genetically obese Zucker rats, using a specific radioimmunoassay for IAPP. Obesity and hyperinsulinemia were observed in rats 21 days after VMH lesioning. IAPP content was increased in the islets of VMH-lesioned rats compared with findings in the sham-operated controls (100.9 +/- 6.6 vs 72.8 +/- 3.85 fmol/islet; P less than 0.01). Isolated islets of VMH-lesioned rats secreted larger amounts of IAPP in the presence of 2.8 and 16.7 mM glucose (2.99 +/- 0.98 and 11.2 +/- 0.29 fmol islet-1 3 h-1) than was noted in sham-operated rats (ND and 6.65 +/- 0.78 fmol islet-1 3 h-1). In the obese Zucker rats, aged 14 weeks, IAPP concentrations in the islets were elevated compared with lean rats (133.3 +/- 10.6 vs 84.4 +/- 8.5 fmol/islet; P less than 0.01). The isolated islets secreted larger amounts of IAPP in response to 2.8 and 16.7 mM glucose (2.83 +/- 0.88 and 15.81 +/- 1.35 fmol islet-1 3 h-1) than did those from lean control rats (0.36 +/- 0.19 and 12.49 +/- 1.20 fmol islet-1 3 h-1). These results strongly suggest that overproduction and hypersecretion of IAPP occur in animals with obesity and hyperinsulinemia.

Amyloid↗
PubMed1992

An epidemiological study on hyponatremia in psychiatric patients in mental hospitals in Nara Prefecture.

Hyponatremia occurs often in mental illness. The frequency was not noticed because of the uncharacteristic symptoms of mild hyponatremia. Of the 1,114 psychiatric inpatients retrospectively surveyed, 10.5% had hyponatremia. Not only patients with schizophrenia, but also patients with other mental illness, especially with epilepsy, having hyponatremia were confirmed. An early onset, a long duration of psychiatric disorder and a prolonged admission were statistically significant factors. Nicotine abuse was not a significant factor. It was suggested that the pathogenesis of hyponatremia in psychiatric patients might be involved in a chronic course of psychiatric disorders and poor response to psychopharmacotherapy.

Adult↗
PubMed1992

Islet amyloid polypeptide/amylin in pancreatic beta-cell line derived from transgenic mouse insulinoma.

We examined the production and secretion of IAPP in a beta-cell line, MIN6, which is derived from an insulinoma obtained by targeted expression of the SV40 T-antigen gene in a transgenic mouse. RNA blot analysis revealed an abundance of IAPP and insulin II mRNA in the cells, findings comparable with those in the pancreas of a normal mouse. The presence of IAPP and insulin was confirmed immunohistochemically and by RIA. Analysis of the reverse-phase HPLC identified IAPP in cells with authentic mouse IAPP. Raising the glucose concentration from 5.6 to 25 mM failed to induce increments in IAPP and insulin II mRNAs. The cells secrete IAPP and insulin for short- and long-term incubations in response to concentration of glucose in the medium. These features resemble those of islet cells from normal animals. This beta-cell line will aid in analyzing the regulation of IAPP gene expression and the mechanisms of IAPP biosynthesis and secretion.

Amyloid↗
PubMed1992

[Evaluation of myocardial disorders in patients with dilated cardiomyopathy and left ventricular eccentric hypertrophy--by 201Tl myocardial SPECT].

201Tl myocardial SPECT was performed in cases of dilated cardiomyopathy and valvular heart disease with left ventricular eccentric hypertrophy, and the two groups were compared from the standpoint of the mechanism of onset of myocardial disorders. Significant coefficients of correlation were seen between the Tl score and LVDd (r = 0.792, r = 0.785) and Tl score and LVEF (r = -0.634, r = -0.555) in both dilated cardiomyopathy and valvular heart disease. In cases of valvular heart disease, significant correlation coefficients (r = -0.756, r = -0.720) between LVDd and r-WR (relative-washout rate), and Tl score and r-WR were observed, but no such correlation was seen in dilated cardiomyopathy. In valvular heart disease, a decrease in myocardial perfusion associated with enlargement of the left ventricle appeared, while in dilated cardiomyopathy, there was a marked decrease in LVEF in proportion to the thallium defect. Therefore, it was assumed that left ventricular wall disorders occur due to myocardial metabolic disorders and coronary microcirculation disorders.

Adult↗
PubMed1991

[Clinical and pathological analysis of deep mycoses].

Clinical and pathological analysis were performed on 127 cases of deep mycoses diagnosed by autopsy during the 24 years between 1964 and 1987 in Juntendo University Hospital. The following findings were obtained. 1) There has been a tendency for the number of mycoses to increase each year, especially notable for candidiasis and aspergillosis. 2) Underlying diseases were, in order of incidence, various hematologic diseases, solid tumors, inflammatory diseases and collagen diseases; the most common were various types of leukemia. 3) Candidiasis was often observed in patients with gastrointestinal tract cancers. Aspergillosis was often observed in patients with collagen diseases. 4) Regarding the visceral distribution of mycoses, aspergillosis was observed in the lung, candidiasis was observed in the lung, kidney and intestinal tract in decreasing order, and cryptococcosis was also observed in the lung and central nervous system. 5) There was a probability of fungal infections occurring in cases of lymphopenia. 6) A fever was present at the time of hospitalization in many cases of aspergillosis, and the presence of an indwelling catheter was a common feature in cases of candidiasis. 7) Fungemia was frequently observed in candidiasis, but very rarely in cases of aspergillosis. 8) The large amounts of corticosteroid hormones and blood transfusions were suspected as causative factors of fungal infections.

Adolescent↗
PubMed1991

Hypersecretion of islet amyloid polypeptide from pancreatic islets of ventromedial hypothalamic-lesioned rats and obese Zucker rats.

To investigate the possible role of islet amyloid polypeptide (IAPP) in the development of type 2 diabetes mellitus, we examined the IAPP content and secretion in pancreatic islets isolated from ventromedial hypothalamic (VMH)-lesioned rats and genetically obese Zucker rats, using a specific RIA for IAPP. Obesity and hyperinsulinemia were observed in rats 21 days after VMH lesioning. IAPP content was increased in the islets of VMH-lesioned rats compared with findings in the sham-operated controls (100.9 +/- 6.6 vs. 72.8 +/- 3.85 fmol/islet; P less than 0.01). Isolated islets of VMH-lesioned rats secreted larger amounts of IAPP in the presence of 2.8 mM and 16.7 mM glucose (2.99 +/- 0.98 and 11.2 +/- 1.29 fmol.islet(-1).3 h-1) than was noted in sham-operated rats (ND and 6.65 +/- 0.78 fmol.islet(-1).3 h-1). In the obese Zucker rats, aged 14 weeks, IAPP concentrations in the islets were elevated compared with lean rats (133.3 +/- 10.6 vs. 84.4 +/- 8.5 fmol/islet; P less than 0.01). The isolated islets secreted larger amounts of IAPP in response to 2.8 mM and 16.7 mM glucose (2.83 +/- 0.88 and 15.81 +/- 1.35 fmol.islet(-1).3 h-1) than did those from lean control rats (0.36 +/- 0.19 and 12.49 +/- 1.20 fmol.islet(-1).3 h-1). These results strongly suggest that overproduction and hypersecretion of IAPP occur in animals with obesity and hyperinsulinemia.

Amyloid↗
PubMed1991

Amyloid protein in somatostatinoma differs from human islet amyloid polypeptide.

Amyloid deposits in somatostatinomas are rare observations. To examine the characteristics of this amyloid, we compared amyloid deposits in a somatostatinoma to those found in pancreatic tissue in patients with Type II diabetes mellitus and in insulinomas, using immunohistochemical techniques and specific antibodies to islet amyloid polypeptide or other pancreatic hormones, as well as electron-microscopy. Antibodies to islet amyloid polypeptide regions 8-17 or 25-37 were confirmed to be specific. Amyloid deposits in patients with Type II diabetes mellitus and in insulinomas, but not those in the somatostatinoma strongly reacted with these antibodies, or to an antibody to amyloid P component. Amyloid deposits in the somatostatinoma were not reactive with antibodies to somatostatin or to other pancreatic hormones. Electron-microscopic examinations revealed that amyloid fibrils in the somatostatinoma were thinner and more randomly distributed than were those in islets from patients with Type II diabetes mellitus. As amyloid in somatostatinomas is unlike that consisting of islet amyloid polypeptide or other mature pancreatic hormones, it may be a novel type of local amyloid in pancreatic islets.

Adult↗
PubMed1991

[Left ventricular wall damage as an indicator for valve replacement in patients with volume overload: a radionuclide study].

Using Tl-201 myocardial single photon emission computed tomography (SPECT), we tried to utilize the Tl-defects to determine the timing for aortic or mitral valve replacement in cases with chronic aortic (AR) or mitral regurgitation (MR), or both. Examinations including echocardiography and angiography were performed to evaluate left ventricular dilatation. Subjects consisted of 80 patients, including 22 with AR, 26 with MR, 17 with AR+MR, and 15 post-operative cases. The Tl-scores (sum of the grade of Tl-defects) correlated well with T wave abnormalities (V5) and NYHA functional class. The scores also correlated with left ventricular end-diastolic dimension (LVDd) and LV ejection fraction (LVEF), indicating that the LV wall defect progressed as the LV dimension increased with the increase in the volume load. Exercise Tl-201 myocardial SPECT revealed redistribution at an early stage of valvular regurgitation, indicating the development of LV wall damage in cases of LV enlargement due to regurgitation. Valve replacement caused a decrease in LVDd, with mild improvement in the Tl-score. We concluded that, in addition to the T wave changes and the echocardiographic measurements, Tl-201 myocardial SPECT should be included in the criteria for valve replacement.

Aortic Valve Insufficiency↗
PubMed1990

[A study of dental soldering. (10) The temperature distribution of infra-red soldering machine].

The purpose of this study is to measure the temperature distribution of focused energy by infra-red soldering machine. The result indicate following. 1. The three dimensional heating area is an ellipse shape, and soldering area is about 10 mm in diameter centering around the focus. 2. Temperature adjustment of INFRARED (NEY Co.) is to use Powerlevel, and of BEAMWERDER (YOSHIDA Co.) is adjusting the height of the turn table. 3. When soldering with focused energy with infra-red machine, it is adequate to solder at the focused level or the upper level, after pre-heating of the soldering objects at the lower level.

Dental Soldering↗
PubMed1990

[A case of cardiac amyloidosis showing the ischemic change by exercise Tl-201 myocardial scintigraphy].

A case of cardiac amyloidosis, which was recognized as an ischemic change by exercise Tl-201 myocardial scintigraphy, was studied. The case was 41 year-old woman, whose initial symptom was pretibial edema and died of ventricular fibrillation. Ischemic change was ascertained by the treadmill exercise test and exercise Tl-201 myocardial scintigraphy, however, the significant coronary stenotic lesion was not detected by coronary angiography. Our data suggested that ischemic change may be related with the disturbance of microcirculation caused by deposit of amyloid in the vessels and/or around the vessels from the pathological findings.

Adult↗
PubMed1989

Secretion of islet amyloid polypeptide in response to glucose.

The content of islet amyloid polypeptide (IAPP) in isolated rat pancreatic islets was determined by a radioimmunoassay. Reverse-phase high-performance liquid chromatography analysis revealed that a main peak of IAPP immunoreactivity in the extracts from the islets corresponded to a synthetic rat IAPP. Secretion of IAPP from the cells is regulated by the extracellular glucose concentration. Thus, IAPP may be a novel regulator for glucose homeostasis and changes in the secretion perhaps relate to insular amyloid deposits and impaired glucose tolerance in type 2 diabetes mellitus.

Amyloid↗
PubMed1989

Islet amyloid polypeptide inhibits glucose-stimulated insulin secretion from isolated rat pancreatic islets.

Islet amyloid polypeptide has 37 amino acids and is a major component of amyloid deposition in pancreatic islets of patients with type 2 diabetes mellitus. To determine whether the peptide is involved in the impaired insulin secretion in this type of diabetes mellitus, we synthesized islet amyloid polypeptide and its fragments and examined its effect on insulin secretion. Islet amyloid polypeptide inhibited the glucose-stimulated insulin secretion from isolated rat pancreatic islets, as calcitonin gene-related peptide did, but the fragments failed to inhibit the secretion. Thus, we propose that amyloid deposition may be an important factor in the impairment of insulin secretion in type 2 diabetes mellitus.

Amino Acids↗
PubMed1989

Manners of arginine vasopressin secretion in schizophrenic patients--with reference to the mechanism of water intoxication.

Water intoxication occurs almost exclusively in many patients with chronic psychiatric disorder. To elucidate the mechanism of this syndrome, we undertook the following animal experiments and clinical study. Twelve rabbits were given neuroleptics for eight weeks. From measurement of arginine vasopressin (AVP) secretion response to osmotic stimuli (fluid deprivation, partaking ad lib. and water loading), we found that chronic neuroleptic administration might raise the sensitivity of AVP escretion response. Then we investigated the manners of AVP secretion during ad lib. drinking in seventeen schizophrenic patients with hyponatremia and sixteen schizophrenic patients without hyponatremia. Normal range of plasma AVP was obtained from healthy volunteers by water loading. Only in both schizophrenic groups was plasma AVP detected below 270 mOsm/kg osmolality. We observed that sensitivity of AVP secretion response to osmolality was decreased in schizophrenic patients, regardless of the presence of hyponatremia. We hypothesize that the primary low sensitivity of AVP secretion response to osmo-receptor and the secondary renal hypersensitivity of AVP receptor may play the major role in the occurrence of water intoxication, linked to SIADH, in schizophrenic patients.

Adult↗
PubMed1989

Elevated serum secretory IgA in patients with IgA nephropathy.

Serum secretory IgA was measured to elucidate the significance of secretory IgA in patients with IgA nephropathy. The levels of serum secretory IgA and IgA were, respectively, 6.8 +/- 3.5 micrograms/ml and 231.0 +/- 69.2 mg/dl in the controls and 11.8 +/- 3.2 micrograms/ml and 385.3 +/- 78.7 mg/dl in the patients. The levels of serum secretory IgA and IgA in the patients were significantly higher than those in controls (p less than 0.01). Elevated serum secretory IgA may reflect the excessive state of the IgA-secreting system in IgA nephropathy patients.

Adolescent↗