Search PubMed⌕ Search

Biomedical subjects

S Shimazaki

Publications and source records attributed to S Shimazaki.

At least 55 records · Page 3Linked to original sources
PubMed1995

[Effects of prostaglandin E2 and sodium hyaluronate on bradykinin induced knee joint pain in rat].

We studied effects of prostaglandin E2 and sodium hyaluronate on the reactive muscle activity induced by intra-articular injection of bradykinin into the knee joint of rat. An animal model was developed to evaluate knee joint pain. In unanesthetized and spinalized rat, bradykinin (BK) was injected into the knee joint and the duration of the reactive activity of the knee flexor was evaluated. The duration of the reaction was elongated dependent on the injected BK dosage (0.025-2.5 micrograms). When prostaglandin E2 (PG E2) was injected with BK, the duration of the reaction increased significantly (p < 0.01). In contrast, sodium hyaluronate (Na-HA: average MW 900 kD) injected into the joint 3-24 hours in advance significantly inhibited the BK induced reaction (p < 0.05-0.01). A histological study demonstrated the fluorescein-labeled Na-HA diffusely infiltrating into the surface of the soft tissue. From these results, the animal model used in the present study was valuable to evaluate quantitatively knee joint pain. Furthermore, the sensitizing effect of PG E2 and the inhibitory effect of Na-HA on joint pain was objectively demonstrated.

Animals↗
PubMed1994

Molecular construction of Clostridium botulinum type C progenitor toxin and its gene organization.

The 16S progenitor toxin of Clostridium botulinum type C is made up by conjugation of a neurotoxin with nontoxic components designated as nontoxic-nonHA and hemagglutinin (HA). The HA was found to be composed of subcomponents having 53, 33, 22-23, and 17 kDa molecular masses. Since we previously determined the whole nucleotide sequences of the genes for neurotoxin, nontoxic-nonHA, and HA-33, the cloning and nucleotide sequencing of the genes for the remaining HA subcomponents were performed. Two open reading frames coding for 16.7 kDa (HA-17) and 70.6 kDa proteins were identified. The N-terminal amino acid sequences of HA-53 and HA-22-23 indicated that the 70.6 kDa protein is split into 53 and the 22-23 kDa proteins after translation and that the 22-23 kDa protein consists of at least four proteins showing slightly different molecular weights.

Amino Acid Sequence↗
PubMed1994

Dimerization characteristics of the DNA- and steroid-binding domains of the androgen receptor.

The DNA-binding domain (DBD) of the androgen, mineralocorticoid, and glucocorticoid receptors and the steroid-binding domain (SBD) of the androgen receptor (AR) were expressed separately as fusion proteins with glutathione-S-transferase (GST) in Escherichia coli. Native polyacrylamide gel electrophoresis and gel exclusion HPLC demonstrated that the GST-ARDBD fusion protein was present as a dimer. On the other hand, the GST-ARSBD fusion protein formed a high-molecular weight oligomer, which seemed to be formed by two separate interactions, i.e. GST-GST and ARSBD-ARSBD between the fusion molecules. These findings strongly suggest that ARSBD has a potent ability to form a homodimer and that ARDBD does not. GST-ARDBD specifically interacted with the glucocorticoid response elements of the mouse mammary tumor virus long terminal repeat (GREMMTV). Cleavage of the fusion protein by thrombin abolished the binding, while the nonspecific DNA-cellulose binding ability was retained. Therefore, the dimeric configuration of GST-ARDBD, even if accomplished through the interaction with the GST moiety, is needed for high-affinity binding to the response element. The binding of GST-ARDBD to GREMMTV was strongly competed by the glucocorticoid response element of rat tyrosine aminotransferase gene, followed by the androgen response element of the rat probasin gene. A palindromic thyroid response element showed no competition. Unexpectedly, no apparent different in the binding affinity to these response elements was observed among the DBDs of androgen, mineralocorticoid and glucocorticoid receptors.

Amino Acid Sequence↗
PubMed1994

Severe hyponatremia in a patient with renovascular hypertension: case report.

We report a 2-year-old boy with renovascular hypertension caused by stenosis of the left renal artery that was successfully treated by percutaneous transluminal angioplasty (PTA). He initially presented with severe hyponatremia, hypokalemia, polyuria, transient proteinuria and weight loss. This phenomenon is known to occur in patients with renovascular and malignant hypertension, called hyponatremia hypertensive syndrome, but was thought to be rare in children. Renovascular hypertension should be considered as a cause of hyponatremia in children. In addition, PTA is an appropriate treatment even in very young children with renovascular hypertension.

Angioplasty, Balloon↗
PubMed1993

Successful balloon mitral commissurotomy in a small child: use of small Inoue balloon catheter.

A 15-month-old girl weighing 5.8 kg, in whom congestive heart failure developed due to congenital mitral stenosis, was successfully treated by percutaneous transluminal mitral commissurotomy using a small Inoue balloon catheter. Percutaneous transluminal mitral commissurotomy using a small Inoue balloon catheter may be a first-choice treatment for small children with congenital mitral stenosis.

Catheterization↗
PubMed1993

Detection of tumor necrosis factor-alpha-positive cells in cerebrospinal fluid of patients with HTLV-I-associated myelopathy.

Tumor necrosis factor (TNF)-alpha-positive cells constituted 1.6-18% and 8.2-23.5% of the total number of cerebrospinal fluid cells from six of 12 patients with HTLV-I-associated myelopathy and in all samples obtained from inflammatory cases, respectively. However, in non-inflammatory cases no TNF-alpha-positive cells were detected. These results suggest that some of the infiltrating CSF cells produce TNF-alpha, which plays a role in host immune defenses against causative agents including HTLV-I and in lesion formation within the central nervous system in inflammatory diseases.

Adult↗
PubMed1993

A review of the present emergency medical care system in Japan.

EMT's in the United States initiate emergency treatment including patient resuscitation at accident locations. Such treatment has only recently become available in Japan. In 1992, Emergency Life Support Technicians (ELT's) became available in Japan. ELT's can now implement emergency treatment similar in scope to that of EMT's in the United States. We expect the rate of lifesaving resuscitation and subsequent rehabilitation will improve dramatically. The triage decision making process is designed to aid in choosing appropriate health care facilities. The highest available level of medical expertise should be brought into the triage decision making process. Throughout Japan, improvements in the emergency medical care system are being made in an ongoing process. The Tokyo Fire Department in particular has made great progress in updating and improving its system. It continues to investigate possible innovations which could lead to further improvements.

Data Collection↗
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↗