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Biomedical subjects

S Ohkawa

Publications and source records attributed to S Ohkawa.

At least 109 records · Page 6Linked to original sources
PubMed1993

[Long-term follow-up study after permanent pacemaker implantation in patients aged 60 years or over with sick sinus syndrome].

Ninety-five patients aged 60 years or over with a permanent pacemaker implanted for sick sinus syndrome were divided into two groups: 32 patients with physiological pacing (group P) and 63 patients with ventricular pacing (group V). The mean follow-up period was 45.0 +/- 36.6 months in group P and 50.3 +/- 37.8 months in group V. Paroxysmal atrial fibrillation (Af) occurred in 28% of group P and 71% of group V (p < 0.05). The incidence of stable Af was also lower in group P than in group V (9% vs. 30%, p < 0.05). None of group P with only bradyarrhythmia had stable Af. However, 6 of 21 patients (29%) in group V with bradyarrhythmia showed stable Af. There was no significant difference in stable Af between group P with bradycardia-tachycardia syndrome (BTS) and group V with BTS (19% vs. 31%). A lower incidence of embolic events was also observed in group P (3% vs. 25%, p < 0.05). Nine of 16 patients with embolic events in group V died of complications following embolism (8 patients; cerebral embolism, one patients: renal and superior mesenteric arterial embolism). The survival rates at 5 and 10 years were 80% and 69%, respectively, for group P and 56% and 33% for group V (p < 0.01). Thus, with regard to permanent pacing for patients with sick sinus syndrome, physiological pacing should be selected for control of morbidity and total mortality.

Aged↗
PubMed1993

Prevalence and clinical significance of anomalous muscular band in the left atrium.

The significance of left ventricular false tendon and right atrial anomalous muscular band has been previously reported. As well as in the right atrium, anomalous muscular band is sometimes observed in the left atrium. To evaluate the prevalence and clinical significance of the left atrial anomalous band, a clinico-pathologic study was performed among 1,100 autopsies over 60 years. The following results were obtained: (1) Pathologically, the incidence of the left atrial anomalous band was 2% (22 cases among 1,100 autopsies). The anomalous band connected the left atrial side of fossa ovalis with the other areas of left atrial endocardium in most of the cases (19 cases). The cases with the bands had Chiari's network and patent foramen ovale at the same time more frequently than those without the bands (Chiari's network: 27% vs 8%, p < 0.01, patent foramen ovale: 23% vs 8%, p < 0.05). Microscopically, the anomalous band was composed of fibrous and muscular tissues. (2) Clinically, premature atrial complex was more frequently observed among the cases with left atrial anomalous bands than those without the bands (41% vs 11%, p < 0.01). In conclusion, left atrial anomalous band seemed to be one of congenital abnormalities which was associated with Chiari's network and patent foramen ovale in origin, and might be one of the causes of supraventricular arrhythmias.

Aged↗
PubMed1993

[Pathology and histochemistry of mitral valve prolapse].

UNLABELLED: To analyze the myxomatous changes and the components of acidic glycosaminoglycans (GAG) of the mitral valve in aged patients with the mitral valve prolapse (MVP) syndrome, a pathological and histochemical study was performed on hearts of 18 autopsied cases with MVP. The histochemical study included toluidine blue Ohno's method, and 3 enzymatic digestion tests with streptomyces hyaluronidase, chondroitinase AC-II and chondroitinase ABC. The following results were obtained: 1. The incidence of MVP with mitral regurgitation among 2,060 elderly autopsy patients over 60 years of age was 0.87%. 2. PATHOLOGICAL FINDINGS: marked prolapse was detected in the anterior leaflet of 3 patients, moderate prolapse in the anterior leaflet of 6 and moderate prolapse in the posterior leaflet of 5. Most patients showed greater prolapse in the anterior than in the posterior leaflets. The MVP of 11 patients (61%) was associated with tricuspid valve prolapse. 3. Histological findings: All cases exhibited thickening at the rough zone; 17 patients showed enlargement of the spongiosa layer, and 15 showed a decrease or disappearance of the fibrosa layer. All cases showed various degrees of change in the atrialis layer. The main site of myxomatous change in the mitral valve of MVP was the spongiosa layer of the rough zone. 4. Histochemical findings: Results using 3 methods of enzymatic digestion tests were positive in 13 patients, which suggested that the major component of increased GAG at the myxomatous changes in the mitral valve of MVP was hyaluronic acid, as did the results with Ohno's toluidine blue method.

Aged↗
PubMed1992

[Biliary enhanced MR imaging by Gd-DTPA].

Biliary enhanced MRI (BEMRI) by Gd-DTPA via PTCD and/or PTGBD tube for obstructive jaundice was performed in 8 patients. In all cases, biliary tract was clearly visualised as high signal intensity on T1 weighted images. On same images, primary lesion such as common bile duct cancer was also visualised as well as portal system. In addition, MR angiography (MRA) by 2D-time of flight method was performed. MRA with BEMRI shows portal encasement on the same image as biliary tract obstruction. It suggests MRA with BEMRI may replace the other modality for obstructive jaundice.

Biliary Tract↗
PubMed1992

Interaction between endothelium-derived relaxing factors, S-nitrosothiols, and endothelin-1 on Ca2+ mobilization in rat vascular smooth muscle cells.

S-Nitrosothiols (S-nitrosocysteine, S-nitrosoglutathione and S-nitroso-N-acetylpenicillamine), which belong to the group of endothelium-derived relaxing factors (EDRFs), caused decreases of cytosolic free Ca2+ concentrations ([Ca2+]i) in cultured rat vascular smooth muscle cells (VSMCs). The endothelin-1 (ET-1)-induced sustained increase of [Ca2+]i in rat VSMCs was completely abolished by preaddition of at least an equal molar quantity of S-nitrosocysteine (Cys-SNO). Also exposure of VSMCs to a mixture of Cys-SNO and ET-1 at the same time resulted in the transient increase only. These results suggest that S-nitrosothiols may have no significant effect on ET-1-induced Ca2+ release from intracellular stores via inositol 1,4,5-triphosphate production but do affect Ca2+ influx through Ca2+ channels in the plasma membrane.

Animals↗
PubMed1992

Surgical laser ablation of a pediatric idiopathic ventricular tachycardia.

A pediatric patient with medically refractory idiopathic ventricular tachycardia was successfully treated by surgical laser ablation. Application of laser on the normothermic beating heart enables continuous electrophysiological assessment. The histopathology of idiopathic ventricular tachycardia and the advantages of laser ablation are presented.

Atrioventricular Node↗
PubMed1992

Development of hepatocellular carcinoma associated with increases in DNA synthesis in the surrounding cirrhosis.

The relationship between DNA synthesis activity in hepatocytes from cirrhotic tissue and development of hepatocellular carcinoma was studied in 33 posthepatitic patients with Child's grade A cirrhosis. DNA synthesis activity was measured by a bromodeoxyuridine (a thymidine analogue) labeling index, using the bromodeoxyuridine-antibromodeoxyuridine in vitro method, and the patients were followed up prospectively with frequent liver ultrasonography for 2 years. During the 2-year follow-up, 11 of the 33 cirrhotic patients developed hepatocellular carcinoma; they included 8 of the 15 patients (53%) in the high labeling index (greater than 1.5%) group compared with only 3 of the 18 patients (17%) in the low labeling index (less than 1.5) group (P less than 0.05). Five of the latter 18 subsequently had increased synthesis activity. Of these 20 patients who showed high synthesis activities either initially or subsequently, 10 (50%) developed hepatocellular carcinoma, in contrast to 1 of 13 (8%) with persistently low activities (P less than 0.05). Thus, hepatocellular carcinoma seems to develop or may become detectable when DNA synthesis in the background cirrhosis is increasing or remains high.

Adult↗
PubMed1992

Characterization of "modified-self"-induced specific antibody hyporesponsiveness to herpes simplex virus.

Pretreatment of mice iv with syngeneic spleen cells modified with soluble HSV envelope antigens induced an anti-HSV antibody hyporesponsiveness following challenge with infectious virus. The epitope density on the HSV-modified spleen cells was quantitated using a photon-counting spectrofluorimeter so that observed immunological results could be correlated with the HSV antigen dose on the splenocytes. The degree of anti-HSV antibody hyporesponsiveness was found to be related to the epitope density on the HSV-modified spleen cells, but not the number of modified cells used in the pretreatment over the 16-fold range tested. Anti-HSV antibody hyporesponsiveness was induced if 7, but not 3, days had elapsed between pretreatment and challenge. This antibody hyporesponsiveness could be adoptively transferred with T cells. Only mice that had induced an anti-HSV antibody hyporesponsiveness following pretreatment with HSV-modified splenocytes were able to survive an LD50 challenge with infectious virus.

Animals↗
PubMed1992

Intravenous recombinant tissue plasminogen activator in acute carotid artery territory stroke.

To determine the effect of intravenous recombinant tissue plasminogen activator (rt-PA) on vascular and neurologic outcomes, we enrolled 31 patients with acute carotid artery-territory ischemic stroke within 6 hours from symptom onset in a randomized, double-blind, placebo-controlled study. We gave either rt-PA (duteplase at the dose of 20 or 30 mega-international units [MIU]) or placebo intravenously for 60 minutes in patients randomly assigned to the three groups. A comparison between the baseline and postinfusion angiograms showed that complete or partial reperfusion occurred in 50% (5/10) of patients treated with 30 MIU rt-PA, 44% (4/9) of those treated with 20 MIU rt-PA, and 17% (2/12) in the control group. In patients with middle cerebral artery occlusions, reperfusion occurred in 71% (5/7) of the 30-MIU group, in 67% (4/6) of the 20-MIU group, and in 13% (1/8) of the control group. Patients treated with 30 MIU rt-PA showed a significantly early and better clinical improvement, as measured by the neurologic scale, than did those treated with placebo. Parenchymal hemorrhage occurred in one patient in each group, and frequency of clinically insignificant hemorrhagic infarction was comparable among the treatment groups. No major systemic complications occurred in any group. These results support the efficacy of intravenous infusion of rt-PA soon after the onset of stroke in producing rapid thrombolysis and neurologic recovery; it may be of particular value in patients with thromboembolic occlusion in the middle cerebral artery.

Acute Disease↗
PubMed1992

[Acute hemodynamic effects of intravenous bolus injection of isosorbide dinitrate in aged patients with congestive heart failure].

In order to investigate whether intravenous bolus injection of isosorbide dinitrate (ISDN) is a safe and efficient therapy in aged patients with congestive heart failure, we studied acute hemodynamic effects in 11 patients. Peak effects on preload were observed after 5 to 10 minutes of bolus injection and unloading effects continued effectively for 60 minutes. At peak effect, pulmonary systolic pressure decreased from 50.2 +/- 2.6 to 36.2 +/- 2.6 mmHg (-28.5%, p less than 0.01) and pulmonary end diastolic pressure decreased from 25.0 +/- 2.2 to 18.5 +/- 2.1 mmHg (-26.0%, p less than 0.01). Mean pulmonary artery wedge pressure decreased from 23.4 +/- 2.2 to 16.0 +/- 2.1 mmHg (-31.6%, p less than 0.01). Mean right atrial pressure decreased from 10.5 +/- 1.8 to 7.4 +/- 2.0 mmHg (-29.5%, p less than 0.01). Blood pressure, heart rate, cardiac index, systemic and pulmonary vascular resistance showed no significant changes. Thus, intravenous bolus injection of ISDN showed a potent vasodilator effects on preload, and may be a safe and useful treatment for aged patients with acute congestive heart failure.

Aged↗
PubMed1992

[An autopsy case of endocardial cushion defect (ECD) in an 82-year-old female].

In an 82-year-old female case of endocardial cushion defect (ECD), a systolic regurgitant murmur was heard at the apex, and her ECG showed atrial fibrillation without right bundle branch block or left axis deviation. An echocardiogram demonstrated atrial septal defect (ASD) and a cleft of the anterior mitral leaflet with calcification. She died of refractory congestive heart failure. Autopsy revealed ECD (intermediate type) with mitral and tricuspid cleft, and ASD (ostium primum type, 2.0 x 1.0 cm in diameter). In addition, mitral ring calcification and calcification of the cleft mitral valve was disclosed, causing mitral stenosis in addition to mitral regurgitation due to the cleft mitral valve. This was the second oldest Japanese autopsy case of ECD. We concluded that echocardiographic examinations, including color flow imaging, in aged patients with heart murmur are necessary to confirm the diagnosis of congenital heart disease in the aged.

Aged↗
PubMed1992

[Congestive heart failure in elderly readmitted patients].

The clinical features of congestive heart failure in the elderly were investigated in 104 patients (57 males, 47 females, mean age of 79.2). Patients were divided into two subgroups, the readmission group, 33 patients who were readmitted within 6 months after discharge, and the non-readmission group. Chief complaints were dyspnea, edema, chest pain, loss of appetite, chest compression, and palpitation. Heart failure was caused by infection, myocardial ischemia, arrhythmia, inappropriate drug usage including poor drug compliance, the use of beta-blockers, excessive intake of sodium, and anemia. Careful use of drug was essential especially in the readmission group. Major underlying heart disease were ischemic heart disease (39.4%), valvular disease (26.9%), hypertensive heart disease (9.6%), with cardiomyopathy, congenital heart disease seen in the minority. There was no statistically significant difference in underlying heart diseases between the two groups. Supraventricular arrhythmias such as atrial fibrillations, paroxysmal atrial fibrillations, paroxysmal supraventricular tachycardias, and premature atrial contractions were noted in 85.3% of the cases. Drugs for treatment were diuretics, digitalis, isosorbide dinitrate, calcium antagonists. ACE inhibitors and alpha-blockers were also used, showing that vasodilators were more extensively used than before. The major complications were hypertension (39.4%), renal dysfunction (27.9%), cerebrovascular disease (26.9%), diabetes mellitus (16.5%), arteriosclerosis obliterans (7.7%). Renal dysfunction, arteriosclerosis obliterans was seen significantly more frequently in the readmission group. The prognosis at one year after admission was significantly worse in the readmission group. In summary, the major underlying diseases were ischemic heart disease, valvular disease, and hypertensive heart disease. Ischemic heart disease was seen more frequently than in previous investigations at our hospital.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1992

[A case of moyamoya-like disease with repetitive TIA on drinking].

We reported here a patient of moyamoya-like disease with repetitive limb-shaking TIAs on drinking. Regional cerebral blood flow (rCBF) was quantified with and without drinking by single photon emission computed tomography with intravenously injected N-isopropyl-p-(I-123) iodoamphetamine (IMP). RCBF was reduced by alcohol ingestion. We speculated that homodynamic TIAs might be caused by impaired autoregulation in the region of the left carotid artery.

Alcohol Drinking↗
PubMed1992

[A case of acute multiple sclerosis mimicking tumor on the neuro-imaging studies].

A 31-year-old woman with a history of suspected optic neuritis was admitted with weakness of right-sided extremities and confusion. On admission general physical examination revealed no abnormality. Neurological examination revealed central facial palsy, mild hemiparesis and hemisensory deficit on the right side. Cerebrospinal fluid analysis showed monocytosis of 29 cells, protein of 82 mg/dl, glucose of 62 mg/dl and myelin basic protein of 6.8 ng/ml. No oligoclonal bands were seen. X-ray computed tomographic (CT) scans showed multiple homogeneous contrast-enhancing lesions in the white matter of bilateral parietal lobes without distinct edema or mass effect. Follow-up CT scans showed ring-enhanced lesions. Magnetic resonance image (MRI) showed multiple Gadolinium-enhanced lesions. Additionally, 123I-IMP SPECT [Gamma view-SPCT 2000 H-20 (Hitachi Co.)] was performed at 30 minutes and 5 hours after intravenous administration of IMP (3 mCi). It showed high IMP uptake corresponding to the CT and MRI lesions. Cerebral angiography was considered to be normal. Other laboratory findings were within normal limits. A biopsy was performed. Histological examination showed spongiosis, gliosis and perivascular cuffing. The histological diagnosis was acute demyelinating disease. After therapy with methylprednisolone, she improved gradually. Enhanced lesions in CT and MRI may correspond to active demyelination at acute MS. High uptake of SPECT may also appear in acute stage, although it has not been reported. We should perform neuro-imaging studies including SPECT on acute MS.

Adult↗