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Biomedical subjects

S Miki

Publications and source records attributed to S Miki.

At least 163 records · Page 9Linked to original sources
PubMed1990

Palliative reconstruction of right ventricular outflow tract in tetralogy with hypoplastic pulmonary arteries.

Twenty-five symptomatic patients with tetralogy of Fallot underwent palliative reconstruction of the right ventricular outflow tract without closure of the ventricular septal defect. Their ages ranged from 5 months to 20 years (mean age, 3.5 years). Eight patients had had 13 prior systemic-pulmonary arterial shunts. There were six hospital deaths (24%). Three patients needed a repeat right ventricular outflow reconstruction. There was one late death. The other patients manifested clinical improvement; hematocrit decreased from 0.54 to 0.43 (p less than 0.01) and arterial oxygen saturation increased from 63.0% to 83.2% (p less than 0.01). The size of the pulmonary artery, defined as the ratio of the sum of the diameter of the right and left pulmonary arteries to the diameter of the descending aorta, increased from 0.72 to 2.06 (p less than 0.01). Sixteen patients underwent a corrective operation 2.4 years after palliation. The results of palliative right ventricular outflow tract reconstruction suggest that it may be an optional strategy for the treatment of symptomatic patients who have tetralogy of Fallot with severely hypoplastic pulmonary arteries.

Adolescent↗
PubMed1990

Multiple congenital aneurysms of the atria.

Aneurysms of both the left and right atria are very rare congenital abnormalities. A 3-year-old boy underwent operation with preoperative diagnosis of aneurysms of both atria and supraventricular tachyarrhythmia. The multiple aneurysms were resected during cardiopulmonary bypass. The patient was asymptomatic after operation and has maintained sinus rhythm.

Child, Preschool↗
PubMed1990

Change of genetic expression by physical compression forces.

Despite intense investigation of transmembrane signalling mediated by lymphocyte surface molecules, the subcellular mechanisms responsible for these phenomena remain poorly understood (Kishimoto, T. et al., 1983). In the present study, an answer for the mechanism is demonstrated by using human B blastoid cell line (CESS) which has IgG and Interleukin 6 (IL-6) receptors on the cell surface and produces IgG in response to IL-6 without any requirement for proliferation (Muraguchi, A. et al., 1981).

Animals↗
PubMed1990

Metabolism and effect on cholesterol metabolism of 3 alpha-hydroxy-7-hydroxyimino-5 beta-cholanoic acid in hamsters.

The metabolic fate of a bile acid analog, 3 alpha-hydroxy-7-hydroxyimino-5 beta-cholanoic acid, was studied in hamsters. This compound was absorbed rapidly from the intestine and secreted into the bile as either taurine- or glycine-conjugates, at the rate similar to that of chenodeoxycholic acid. The ratio of glycine to taurine conjugates for this bile acid analog, 0.2, was much smaller than that for chenodeoxycholic acid, 2.0. After oral administration of a single dose of the labeled analog to intact hamsters, radioactivity was recovered in faces but not in urine. A major metabolite found in the feces was lithocholic acid (60%), whereas unchanged material was present only in a trace amount (2.4%). After the hamsters were fed chow supplemented with 0.075% of this bile acid analog for 21 d, analysis of the gallbladder bile acids revealed that the administered compound accounted for only 1.6% of total bile acids. The biliary bile acid composition was similar to that of chenodeoxycholic acid fed group. In the strain of hamster studied, feeding of the bile acid analog decreased cholesterol absorption significantly (19% decrease, p less than 0.05), and tended to reduce serum and liver cholesterol concentrations.

Animals↗
PubMed1990

Metabolism of 3,7-dioxo-5 beta-cholanoic acid in the biliary fistula rodents and rabbits.

Intestinal absorption and metabolism of 3,7-dioxo-5 beta-cholanoic acid, were studied in the bile fistula rats, hamsters, guinea-pigs and rabbits. The influence of dose (1 and 100 mg/kg) on the absorption and the metabolism was also estimated. The dioxo bile acid was absorbed efficiently from the intestine and quickly excreted into bile in these animals. Large dose did not retard the absorption rate and showed a significant choleretic effect for a few hours. Species differences were observed in the metabolism of this compound. In hamsters and guinea-pigs, most of the metabolites in the bile were conjugated with either taurine or glycine. The proportion of bile acids amidated with glycine was greater with the large dose. In rats, the biliary metabolites were conjugated with taurine, but not with glycine, whereas in rabbits, glycine conjugates were the only recovered metabolites. Unconjugated metabolites were also detected in the bile of the rodents, and the proportion of them rose to 17-29% after the administration of 100 mg/kg quantities. A small part of unchanged 3,7-dioxo-5 beta-cholanoic acid was excreted into the bile as both the conjugated and unconjugated forms in these animals. The greater part of this compound administered was metabolized to 7-ketolithocholic acid, chenodeoxycholic acid and ursodeoxycholic acid. In hamsters and guinea-pigs, chenodeoxycholic acid was a greater metabolite of this compound than ursodeoxycholic acid, while in rats and rabbits, the amount of ursodeoxycholic acid exceeded that of chenodeoxycholic acid. In rats, the resulting dihydroxy bile acids were further metabolized to alpha- and beta-muricholic acids.

Amidohydrolases↗
PubMed1990

Beta-eliminative cleavage of the acidic polysaccharide of Fusarium sp. M7-1 by an enzyme preparation of Cellulomonas sp.

By digestion with an enzyme preparation derived from a culture filtrate of Cellulomonas sp., an unsaturated disaccharide was produced accompanied by the release of mannose and beta 1----2 mannobiose from the acidic oligomer mixture that was obtained from the acidic polysaccharide of Fusarium sp. M7-1 by acetolysis. The unsaturated disaccharide produced was isolated and identified as 4-deoxy-L-threo-hex-4-enopyranouronosyl alpha(1----2)-D-galactose. The same unsaturated sugar linked to the polysaccharide was also produced accompanied by the release of mannose and beta 1----2 mannobiose from the acidic polysaccharide by the enzyme digestion.

Actinomycetales↗
PubMed1990

[Evaluation of the changes in intracranial water, sodium, phosphorus metabolites and intracellular cerebral pH in rats with acute dilutional hyponatremia].

Although most prominent among the clinical manifestations associated with hyponatremia are central nervous system (CNS) symptoms, the alterations in brain function remain poorly understood. In the present study, the alterations in intracellular cerebral pH and intracranial water, sodium and phosphorus metabolites content in rats with acute dilutional hyponatremia were examined by using an in vivo nuclear magnetic resonance (NMR) technique which noninvasively provides continuous informations on intracellular phenomena. Acute dilutional hyponatremia was induced on anesthetized male Sprague-Dawley rats by intraperitoneal injection of distilled water with an initial dose of 10 ml/100 g bw, followed by an additional dose of 5 ml/100 g bw 40 min later. Arterial blood sampling and NMR measurements were made before and every 60 min after the initial injection of distilled water. The treatment with distilled water resulted in dramatic falls in serum Na, Cl and osmolality at 60 min after water loading (Na; from 143.4 +/- 2.6 to 112.3 +/- 1.3 mmol/l, Cl; from 101.02 +/- 2.2 to 78.4 +/- 5.4 mmol/l, Osm; from 306.3 +/- 5.8 to 247.3 +/- 7.3 mOsm/kg H20). 1H-NMR imaging showed the accumulation of brain water as dilutional hyponatremia developed. Intracranial Na content measured by 23Na-NMR spectroscopy decreased significantly at 60 min after of water loading to about 70% of that observed under control condition. Since it has been demonstrated that solute extrusion from the brain with resultant reduction of brain swelling occurs within 60 min after the dilution, this result may be, at least in part, explained by this protective mechanism.(ABSTRACT TRUNCATED AT 250 WORDS)

Acute Disease↗
PubMed1990

[Magnetic resonance angiography using a magnetic resonance flow tagging technique].

A direct bolus imaging method, which was developed for flow quantitation, was applied to the cervical regions of four normal volunteers to perform magnetic resonance angiography. A transverse section of 10 mm thickness was selectively excited to tag blood flow in the supraclavicular region and a projected image of the tagged bolus viewed in terms of anteroposterior direction was obtained after the echo time (TE). Like cine magnetic resonance imaging, multiple images representing four to 16 cardiac phases were obtained with repeated excitations. With a relatively long TE, ranging from 50 to 200 msec, we advanced tagged blood farther downstream, so as to elongate the visualized bolus along the vessel. Within the visualized bolus, the outer layer close to the vessel wall, where the blood flow velocity was slow, stretched like long tails behind the central part of the bolus producing arrow-head shapes, and the tails were assumed to represent the vascular structure. Bilateral common carotid and vertebral arteries were visualized in each image size approximately 5 cm obtained at the systolic phase. Since prolonged TE yielded less signal intensity, the bolus was not clearly visualized when TE was longer than 100 msec. The cine display of images with multiple cardiac phases produced good evaluations of dynamic changes of pulsatile flow, and this method is expected to be a useful diagnostic tool which combines the capability of flow quantitation with non-invasive angiography. The accuracy of this method in delineating a stenotic lesion was also evaluated using phantom with steady flow, since it is one of the most important capabilities of a clinically used angiographic method.(ABSTRACT TRUNCATED AT 250 WORDS)

Angiography↗
PubMed1990

[Hyponatremia in isolated deficiency of adrenocorticotropic hormone: role of a decrease in aldosterone secretion independent of antidiuretic hormone excess].

We report a case of 47-year-old woman with an isolated deficiency of adrenocorticotropic hormone. She was admitted complaining of fatigue and frequent loss of consciousness. The patient developed severe hyponatremia (100 mEq/l) after five days of the admission. Her plasma renin activity and plasma aldosterone concentration were low though she was dehydrated. After the treatment of dehydration, plasma osmolality was low but high plasma antidiuretic hormone (ADH) level sustained. Both high urinary sodium excretion and low urinary aldosterone excretion still remained after one month of replacement therapy with prednisolone. But, glomerular filtration rate and a response of urinary volume to acute water loading were normalized. These results suggested that severe hyponatremia of the patient was caused by an inappropriate secretion of ADH and suppression of renin-aldosterone system. We consider the suppression of renin-aldosterone system was partially independent of an inappropriate secretion of ADH.

Adrenocorticotropic Hormone↗
PubMed1990

[A case of asbestos exposure complicated by a malignant pheochromocytoma].

Reported is a case of non-functioning malignant pheochromocytoma. The patient had an occupational history of asbestos exposure and pleural plaque was seen in the chest X-rays. The tumor appeared from right adrenal gland and its size was 12 x 15 cm, which was measured by CT scanning. This determined to be non functioning because catecholamines in the serum and VMA in the urine were within normal limits. A metastasis of this tumor was seen in the lung, the liver, and the bone. So far as is known, this is the first case of asbestos exposure complicated with malignant pheochromocytoma that has been reported in the Japanese literature.

Adrenal Gland Neoplasms↗
PubMed1990

[Angiotensin and prostaglandins in the pressure-natriuresis response in rats].

The possible roles of angiotensin and prostaglandins as humoral mediators of the pressure-natriuresis response were studied in anesthetized Sprague-Dawley rats. Neural and other hormonal influences on the kidney were held constant by denervating the kidney and by maintaining fixed high plasma levels of aldosterone, corticosterone, vasopressin and norepinephrine by continuous intravenous infusion. Acute elevation of arterial pressure by tightening the ligature placed around the abdominal aorta below the renal artery produced marked increases in urine flow and sodium excretion with no detectable changes in renal blood flow or glomerular filtration rate. In rats undergoing a saline diuresis, the pressure-natriuresis response was markedly inhibited by intravenous infusion of angiotensin II at a rate of 10 ng/kg/min. Blockade of prostaglandin synthesis with indomethacin also reduced the pressure-natriuresis response in the presence of low-dose (2 ng/kg/min) of angiotensin II, but indomethacin alone did not affect significantly. On the other hand, in rats with hydropenia indomethacin alone significantly inhibited the sodium excretory response to changes in arterial pressure. This indomethacin-induced inhibitory effect on the pressure-natriuresis response was completely attenuated in rats treated with captopril. These results indicate that angiotensin II is a powerful modulator of the pressure-natriuresis response. In addition, it has been suggested that prostaglandins are also capable of modulating the response only in the presence of the renin-angiotensin system. However, neither angiotensin nor prostaglandins appears to be essential for the basic pressure-natriuresis phenomenon since the pressure-natriuresis response can occur during blockade of both the renin-angiotensin and prostaglandin systems.(ABSTRACT TRUNCATED AT 250 WORDS)

Angiotensin II↗
PubMed1989

Interleukin-6 (IL-6) functions as an in vitro autocrine growth factor in renal cell carcinomas.

Interleukin-6 (IL-6) was found to be a growth factor of renal cell carcinomas Furthermore, renal cell carcinomas freshly isolated from the patients expressed mRNA of IL-6 and secreted biologically active IL-6 under the culture conditions where the tumor cells could grow, but they did not produce IL-6 nor proliferate in the absence of fetal calf serum. The production of IL-6 by the tumor cells was also demonstrated by immunostaining of the IL-6-producing cells utilizing anti-IL-6 antiserum. Moreover, anti-IL-6 antiserum specifically inhibited the in vitro tumor growth. All data indicated that IL-6 functions as an in vitro autocrine growth factor of renal cell carcinomas.

Blotting, Northern↗
PubMed1989

Annuloplastic reconstruction for common atrioventricular valvular regurgitation in right isomerism.

Two patients who had common atrioventricular valvular regurgitation associated with right isomerism, univentricular heart of the right ventricular type, transposition of the great arteries, pulmonary stenosis, and both systemic and pulmonary venous anomalies underwent common atrioventricular valvular annuloplasty. They also underwent bilateral, bidirectional cavopulmonary shunt. A Carpentier's ring was used in patient 1 and a polytetrafluoroethylene tube was used in patient 2 to reduce the diameter of the common atrioventricular annuli. Postoperative catheterization confirmed complete elimination of regurgitation of the common atrioventricular valve in both patients.

Child↗
PubMed1989

Rupture of a Dacron aortic prosthesis into the jejunum.

A 55-year-old man was admitted to the hospital with massive melena and shock. He had a history of Dacron Y graft reconstruction for aortoiliac atheroscerotic occlusive disease 10 years before admission. At emergency laparotomy the jejunum was adherent to the graft. After separation a fistulous communication was detected between the two. A longitudinal tear in the stem of the graft was found. The graft was reconstructed with a Gore-Tex (Gore-Tex registered trademark of W.L. Gore & Associates, Inc., Elkton, Md.) patch. His postoperative course was uneventful.

Aorta↗
PubMed1989

[Long-term evaluation of the superior vena cava-pulmonary artery anastomosis in cyanotic heart disease].

We followed up thirty-three patients, to whom the superior vena cava-pulmonary artery anastomosis (Glenn procedure) was undergone between April 1966 and March 1988. There were eighteen patients with single ventricle and nine with tricuspid atresia, two with pulmonary atresia with intact ventricular septum and four with other complex anomalies. Seven patients (21%), including six with single ventricle, died 0.3 to 14.9 years after operation. Regurgitation of common atrioventricular valve was the cause of death in three patients. Serum hemoglobin level fell down from 19.3 +/- 2.2 g/dl preoperatively to 15.3 +/- 1.9 g/dl after operation but increased gradually to the preoperative level about ten years later. The actuarial survival rate at ten years is 80%. Reoperation was performed in 9 patients and reoperation free rate at 10 years is 78%. This analysis suggests that Glenn procedure is still good palliative operation for ten years, although some patients will be necessitated the second operation in future.

Adolescent↗
PubMed1989

[Report of a case of an atypical huge patent ductus arteriosus].

An atypical huge patent ductus arteriosus (PDA) associated with extreme pulmonary hypertension in a 6-month old female infant was reported. The left 3rd intercostal thoracotomy revealed huge PDA which has an appearance of pulmonary-ductus-descending aorta-trunk (PDDT) on the left side. The right side of the ductus continued to the aortic arch without demarcation between the ductus and the aorta. The median sternotomy clarified the ascending aorta, normal aortic arch, and main pulmonary artery. However, the top of the main pulmonary artery seemed to be fused with the aortic arch. The diagnosis of distal type of aortopulmonary window with wide communication was made and the total circulatory arrest with deep hypothermia and the intracavitary patching for separation of systemic and pulmonary blood flow seemed to be required for the complete repair. Total repair was decided to be postponed one week later and the chest was closed. The patient died of multi-organ failure originating from acute respiratory failure 23 days after exploratory thoracotomy without being repaired. Postmortem examination revealed a huge PDA freely communicating with the ascending aorta and the aortic arch. This is a report of an atypical huge PDA rarely seen and the conventional division or ligation is unfeasible. The circulatory arrest with deep hypothermia and intracavitary patching are obligatory for the surgical repair.

Ductus Arteriosus, Patent↗