PubMed Health⌕ Search

Biomedical subjects

S Shimazaki

Publications and source records attributed to S Shimazaki.

At least 19 recordsLinked to original sources
PubMed1992

Plasma endothelin concentration: relation with vascular resistance and comparison before and after balloon dilatation procedures.

Endothelin (ET) is a potent vasoconstrictor peptide with an as yet uncertain physiological role in cardiovascular disease. We measured blood plasma ET concentrations using a recently developed radioimmunoassay and analysed the relations between ET concentration, systemic arterial pressure and systemic vascular resistance. In addition, ET levels before and after percutaneous balloon valvuloplasty and angioplasty were measured. Fifty-one patients were studied: (1) 13 patients with small left-to-right shunting or Kawasaki heart disease (age ranged from 4 to 144 months); (2) 10 patients who had undergone balloon valvuloplasty or angioplasty (age ranged from 1 to 233 months) and (3) 28 healthy infants and children (age ranged from 3 to 152 months). Systemic vascular resistance was calculated by the formula (mean aortic pressure--mean right atrial pressure) X 80/cardiac output (dyne.sec.cm-5). Plasma ET concentrations in healthy children less than 2 years were significantly higher than those over 2 years (2.48 +/- 0.62 vs 1.31 +/- 0.53 pg/ml). In eight patients in groups 1 and 2, plasma ET concentration in the pulmonary artery (2.00 +/- 0.43 pg/ml) was significantly lower than that in the femoral vein (2.39 +/- 0.69 pg/ml) and aorta (2.23 +/- 0.59 pg/ml), suggesting ET secretion derived from endothelial cells in peripheral pulmonary vessels. There was a significant positive correlation between ET concentrations in the femoral vein and systemic vascular resistance (r = 0.55, p less than 0.05). After balloon dilatation ET concentration rose from 2.15 +/- 0.82 pg/ml to 2.61 +/- 1.38 pg/ml.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1992

High-dose vitamin C therapy for extensive deep dermal burns.

We studied the haemodynamic effects of antioxidant therapy with high-dose vitamin C administration (170 mg/kg/24 h) in guinea-pigs with 70 per cent body surface area deep dermal burns. The animals were divided into three groups of six animals each. Group 1 was resuscitated with Ringer's lactate solution according to the Parkland formula; group 2 with 25 per cent of the Parkland formula with vitamin C; and group 3 with 25 per cent of the Parkland formula without vitamin C. There were no significant differences in heart rates or in blood pressures between the groups throughout the 24-h study period. Group 3 showed significantly higher haematocrit values at 3 h postburn and thereafter as compared with those of group 2. The cardiac output values of group 2 were significantly higher than those of group 3, but equivalent to those of group 1. The water content of the burned skin in group 2 was significantly lower than that in the other groups, indicating that increased postburn capillary permeability was minimized by the administration of vitamin C. With adjuvant high-dose vitamin C administration, we were able to reduce the 24-h resuscitation fluid volume from 4 ml/kg/per cent burn to 1 ml/kg/per cent burn, while maintaining adequate cardiac output.

Animals↗
PubMed1992

Right ventricular dysfunction in septic patients.

OBJECTIVE: To compare right ventricular ejection fraction in trauma and septic patients during the hyperdynamic circulatory phase of these states. DESIGN: Prospective, consecutive study. SETTING: University hospital ICU. PATIENTS: Eleven trauma patients (group 1) and ten septic patients (group 2) were studied. Patients with circulatory shock were excluded from the study. INTERVENTIONS: Right ventricular ejection fraction was measured with a modified pulmonary artery catheter using the thermodilution method. Patients requiring catecholamines to maintain a systolic BP greater than 90 mm Hg were excluded from the study. MEASUREMENTS AND MAIN RESULTS: Both groups 1 and 2 had high mean cardiac output values (cardiac indices 4.7 +/- 0.9 [SD] and 4.6 +/- 1.4 L/min/m2, respectively). Right ventricular ejection fraction was significantly (p less than .005) reduced in septic patients (47 +/- 7.0% vs. 36 +/- 9.7%; group 1 vs. group 2) and end-diastolic volume index was significantly (p less than .01) increased (101 +/- 34 vs. 122 +/- 40 mL/m2; group 1 vs. group 2) in comparison with the trauma patients. However, there were no significant differences in afterload between the two groups. CONCLUSIONS: Hemodynamic measurements comparing septic and trauma patients showed increased cardiac output in both groups and no differences in the pulmonary resistance. Right ventricular ejection fraction in the septic patients was significantly reduced compared with the trauma patients. Therefore, we concluded that right ventricular contractility may be decreased in septic patients.

Adult↗
PubMed1992

Histamine decreases the permeability of an endothelial cell monolayer by stimulating cyclic AMP production through the H2-receptor.

To determine if histamine acts directly on the vascular endothelium, the effect of histamine on the permeability of cultured human endothelial cell monolayers and the role of second messengers were examined. The addition of 10(-6) to 10(-4) M histamine to the culture medium decreased the endothelial cell monolayer permeability and increased both cyclic AMP and free-calcium levels. The decrease in permeability and the increase in cyclic AMP mediated by histamine were prevented by an H2-blocker (famotidine) while the increase in free-calcium was inhibited by an H1-blocker (diphenhydramine). These results suggest that histamine decreases the permeability of endothelial cell monolayers through the H2-receptor, and cyclic AMP plays a more important role than calcium ion as a second messenger.

Animals↗
PubMed1992

Intermediate-term results of balloon valvuloplasty for isolated and complicated pulmonary valve stenosis.

UNLABELLED: The purpose of this study is to report our experience regarding the acute and intermediate-term results of balloon pulmonary valvuloplasty (BPV) in various types of congenital pulmonary valve stenosis. METHODS AND RESULTS: Twenty-four consecutive patients with a median age of 6.6 years (ranging from 1 month to 24 years old) underwent BPV between January 1988 and September 1991. These patients were divided into 2 groups; Group 1 consisting of 13 patients with isolated pulmonary valve stenosis, and Group 2 consisting of 11 patients with complicated pulmonary valve stenosis (supravalvular, subvalvular, valved conduit and post-right ventricular outflow reconstruction). Mean peak systolic pressure gradients from the right ventricle to the pulmonary artery were as follows: In group 1, 48 +/- 21 (mean +/- SD) mmHg before BPV, 18 +/- 8 mmHg immediately after BPV and 13 +/- 5 mmHg at the longest follow-up based on catheterization or Doppler echocardiographic studies. The gradients in group 2 were 65 +/- 28 mmHg before BPV, 46 +/- 25 mmHg immediately after BPV and 47 +/- 21 mmHg at the longest follow-up. CONCLUSIONS: BPV provides both acute and intermediate-term gradient relief in patients with isolated pulmonary valve stenosis. In complicated pulmonary valve stenosis, on the other hand, the effect of BPV was unsatisfactory and appears to depend on the mechanism of associated obstruction. Therefore accurate evaluation of the anatomy of associated obstruction in the pulmonary valve region is needed to determine that BPV is indicated.

Adolescent↗
PubMed1991

Balloon occlusion aortography.

We review the validity of balloon occlusion aortography (BOA) on the basis of our personal experience with 18 patients with congenital heart disease (mean weight 4.55 g, including 8 neonates). Four of the 18 patients underwent aortic arch angiography using balloon occlusion of the descending aorta. Pulmonary angiography was also performed in 9 patients via a patent ductus arteriosus and in 3 patients via a Blalock-Taussig shunt. The remaining 2 patients underwent coronary arteriography by balloon occlusion of the ascending aorta. The information obtained was satisfactory in 17 of the 18 patients. However, in one patient with a double-outlet right ventricle and pulmonary stenosis, the pulmonary arteries were not clearly visualized because of dominant antegrade flow from the right ventricle. BOA is a safe and useful procedure which can be used to image the aortic arch, pulmonary artery, and coronary arteries in infants with congenital heart diseases. In children over 3 years of age, however, the balloon may not be able to occlude the appropriate site of the aorta, so selective angiography is required to obtain precise information.

Aorta, Thoracic↗
PubMed1991

Percutaneous transluminal coronary angioplasty for Kawasaki disease: a case report and literature review.

A 31-month-old boy developed right coronary artery stenosis after Kawasaki disease for which he underwent percutaneous transluminal coronary angioplasty (PTCA). The narrowing of the right coronary artery was successfully dilated by angioplasty without apparent complication. This case suggests that PTCA may have a potential advantage as a temporary method to postpone the aortocoronary bypass surgery in a child with coronary artery stenosis due to Kawasaki disease. However, strict patient selection is recommended for coronary angioplasty.

Angioplasty, Balloon, Coronary↗
PubMed1991

Fluid distribution and pulmonary dysfunction following burn shock.

Respiratory function and body fluid changes were measured in 46 burned patients for up to 7 days postburn (DPB). The patients in this prospective study were divided into an HLS group [n = 17, burn size 61 +/- 0.5% BSA (mean +/- SEM), resuscitated with hypertonic lactated saline] and an iso-Na group (n = 29, burn size 60 +/- 4.5% BSA, resuscitated with lactated Ringer's solution). During DPB 3 to 5, the Respiratory Index (A-aDO2/PaO2), functional extracellular fluid volume (f-ECFV), an ratio of plasma volume to interstitial fluid volume (PV/ISFV) were increased in the iso-Na group compared with the HLS group. During the same period, the Respiratory Index and PV/ISFV correlated significantly; respiratory dysfunction was less in the HLS group. Nearly 50% of the iso-Na group required endotracheal intubation. Sodium loads were the same in both groups; the HLS group required less water. These results suggest that extracellular fluid distribution differs between the two treatments; HLS may be associated with ameliorated respiratory function not only because of less volume loading during resuscitation, but also because the PV/ISFV ratio is less than when lactated Ringer's is administered.

Adult↗
PubMed1990

Coronary artery calcification in Kawasaki disease.

To evaluate the angiographic features of coronary lesions in Kawasaki disease with coronary artery calcification, cinefluoroscopy and cineangiography were retrospectively reviewed in 116 patients who had undergone coronary angiography between 1982 and 1989. Angiographic abnormalities of coronary arteries were demonstrated in 55 of the 116 patients. In 5 (9.1%) of the 55 patients, 9 with calcification were identified by cinefluoroscopy and chest x-ray. Eight of the 9 calcified lesions showed a circular or ring-shape configuration. Coronary angiography revealed a total occlusion of the right coronary artery with collateral circulation from the distal left coronary artery in 2 patients and a severe stenosis of the right coronary artery in 2 patients, in whom anticoagulant therapy had not been continued during the follow-up periods. The remaining patient in whom anticoagulant therapy had been continued had bilateral aneurysms but no significant stenosis. These results indicate that a ring-shape calcification on chest x-ray in a patient with a history of Kawasaki disease may suggest an involvement by coronary artery stenosis even when anticoagulant drugs had been given. Therefore, coronary angiography should be performed to evaluate the stenotic lesions if this type of calcification is found by routine radiographic examination.

Adolescent↗
PubMed1990

[Simultaneous in situ detection of JC virus antigens and RNA in progressive multifocal leukoencephalopathy (PML) by immunocytochemistry and in situ hybridization].

We detected simultaneously JC virus (JCV) antigen and RNA in the frozen brain tissue from a patient with PML using immunocytochemistry and in situ hybridization. Histologically, the majority of JCV antigen positive cells were mainly located at the margin of demyelinated lesions. By simultaneous in situ detection of JCV antigen and RNA, the percentage of both JCV antigen and RNA positive cells in total number cells were 20 in the periplaque region and 2.3 in the central region of plaque respectively. On the contrary, only JCV RNA positive cells were detected 3.6% in the periplaque region and 4.6% in the central region of plaque, while there was not found any positive cells in apparently normal white matter. Moreover, JCV antigen in both antigen and RNA positive cells found in the periplaques was stained homogeneous and filled the whole swollen nucleus, whereas most of both antigen and RNA positive cells appeared in the center of plaques showed small amounts of antigen in the nucleus. From the results, it seems likely that most of the cells displaying only RNA detected in the periplaque were oligodendrocytes in the early stages of productive infection prior to viral protein synthesis. However, a small number of cells displaying only RNA in the center of plaques were likely to be oligodendrocytes and seemed to be in the nonproductive stages of a JCV infection, limited expression of viral protein, influenced by the host immune response including the infiltration of macrophages and humoral immunity.

Antigens, Viral↗
PubMed1990

[The detection and quantitative analysis of viral antigens, infiltrating mononuclear cells, IFN-gamma, LT and IL-6 bearing cells in the frozen brain tissue sections from a patient with herpes simplex encephalitis by immunocytochemistry].

To identify viral antigens, the types of infiltrating mononuclear cells and cytokine bearing cells, the frozen brain tissue sections form a patient with herpes simplex encephalitis who died on 12th hospital days, were examined by immunocytochemistry methods and combined immunocytochemistry and in situ hybridization. The avidin-biotin peroxidase complex (ABC) techniques were applied for the detection of antigens. All monoclonal antibodies to Leu series and polyclonal antisera to lymphotoxin (LT), interleukin-6 (IL-6) and interferon-gamma (IFN-gamma) were purchased form Becton Dickinson Co., and Genzyme Co., (USA) respectively. A large number of neurons and glial cells staining positively HSV-1 antigens were found in the gray matter. Moreover, although a moderate number of HLA-DR (Ia) positive cells were found in the parenchyma, there were few cells displaying positively for Leu-3a, Leu-2a and Leu-7 respectively. To evaluate the number of positive cells appeared in the brain tissues, Leu stain for 4, 2a, 3a, 7, 12 and HLA-DR demonstrated 1.6%, 0.4%, 0.9%, 0.7% and 10% respectively. In addition, numerous number of IFN-gamma positive cells were detected around the lesion and randomly distributed thoroughly the lesion. IL-6 positive cells and LT positive cells were also similar in distribution to IFN-gamma positive cells. Moreover, in simultaneous detection of HLA-DR and HSV-1 mRNA by the combined immunocytochemistry and in situ hybridization, there were seen glial cells staining positively for HLA-DR (Ia) and several cells with mRNA.(ABSTRACT TRUNCATED AT 250 WORDS)

Antigens, Viral↗