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Biomedical subjects

S Eguchi

Publications and source records attributed to S Eguchi.

At least 181 records · Page 10Linked to original sources
PubMed1994

Total circular annuloplasty with absorbable suture for the repair of left atrioventricular valve regurgitation in atrioventricular septal defect.

To obtain a better control of left atrioventricular valve regurgitation, we applied total circular annuloplasty with the use of absorbable sutures to 14 children with atrioventricular septal defect (six complete forms and eight incomplete forms). In the intraoperative period, a good coaptation of the leaflets was achieved and the regurgitation was minimized or disappeared. Follow-up studies with echocardiography for 13 survivors showed a gradual increase of annular size during the postoperative period. Ten patients of the survivor group (77%) maintained good valvular competency in a long-term period. Total circular annuloplasty is a simple and effective procedure to reduce the regurgitation and prevent the annular dilatation during the immediate postoperative period.

Cardiac Surgical Procedures↗
PubMed1994

[How extensive should lymph node dissection be done for the surgery of the left lung cancer?].

Mediastinal lymph node dissection for cancer of the left lung is more difficult than for cancer of the right lung because of the presence of aorta. Location and frequency of lymph node metastasis were examined for 231 left lung cancer patients who underwent pulmonary resection and mediastinal lymph node dissection, and survival rate of them was evaluated. Subaortic (# 5), paraaortic (#6), subcarinal (#7), tracheobronchial (#4) lymph nodes were the most frequently involved N 2 nodes. 5-year survival rate of the patients who had #4, #5, #6, #7, #8 or #9 lymph node metastasis was 20.7%. #4, #5, #6, #7, #8 and #9 should be dissected for the surgery of the left lung cancer.

Carcinoma, Non-Small-Cell Lung↗
PubMed1994

[Effects of subcutaneous administration of erythropoietin on autologous blood predonation in open heart surgery: Japanese multicenter double-blinded dose-study].

The effects of subcutaneous administration of recombinant human erythropoietin (EPO) on harvesting autologous blood predonation (ABP) and decreasing homologous blood transfusion (HBT) in open-heart surgery were examined prospectively in 132 patients treated in a 32-institute multicenter study. Single doses of 6000, 12,000, 18,000 and 24,000 unit (IU) of EPO with intravenous iron (40 mg) were administered once a week for 3 weeks with ABP (400 ml/week) before surgery. ABP volume (ml), change of blood hemoglobin level (C-Hb), preoperative net blood hemoglobin increase (delta Hb [g/dl] including ABP, perioperative blood loss (ml), and HBT rate, were as follows; [table: see text] Preoperative reduction of Hb (C-Hb) was less in administration dose of 18,000 IU and 24,000 IU than 6000 IU (p < 0.05). The increase of delta Hb was highest in 18,000 IU and HBT rate was lowest in administration dose of 24,000 IU, however, there was no statistical difference. In conclusion, both 18,000 IU and 24,000 IU of EPO treatment is effective to minimize the progression of anemia according to ABP for open heart surgery.

Blood Transfusion, Autologous↗
PubMed1993

The effect of bupivacaine hydrochloride on skeletal muscle fiber type transformation by low frequency electrical stimulation.

Bupivacaine hydrochloride (bupivacaine HCl) is known to induce the degeneration and regeneration of skeletal muscles. We examined the priming effect of chronic and continuous nerve stimulation (5 Hz) on regenerating pectoralis major muscle after a single injection of bupivacaine HCl (3 mg/kg). Pectoralis muscle stimulated for 24 days after bupivacaine HCl injection contained 55.4 +/- 8.2% type 1 muscle fibers (n = 4). Control pectoralis major muscle stimulated for 34 days without bupivacaine HCl injection, in contrast, contained 37.7 +/- 5.5% type 1 fibers (n = 5). Therefore, the stimulated pectoralis major muscle with bupivacaine HCl injection contained a significantly larger number of type 1 fibers than that without bupivacaine HCl injection. Undifferentiated myosatellite cells produced by bupivacaine HCl may be primed to differentiate into type 1 cells by chronic low frequency electrical stimulation.

Animals↗
PubMed1993

A case of tachycardia-induced cardiomyopathy due to chronic ectopic atrial tachycardia.

Only a few reports exist that chronic supraventricular tachycardia causes ventricular dilation and poor left ventricular contraction--so-called "tachycardia-induced cardiomyopathy." Clinical and electrophysiologic features of chronic supraventricular tachycardia including chronic persistent ectopic atrial tachycardia (EAT) in adults have also been described by a few investigators. We report a rare case of long follow-up of chronic EAT-induced severe cardiomyopathy and mitral regurgitation that was well controlled after medical treatment.

Cardiac Catheterization↗
PubMed1993

Long-term results of the intracardiac repair of tetralogy of Fallot: a follow-up study conducted over more than 20 years on 100 consecutive operative survivors.

A long-term retrospective and follow-up study was conducted on patients with tetralogy of Fallot to evaluate survival rates and quality of life following surgery. Intracardiac repairs were performed on 132 patients at our institute between January, 1965, and July, 1971, among whom 100 consecutive operative survivors, being 54 males and 46 females, were followed for 20-25 years. Late deaths were confirmed in eight patients (8%) six of which (6%) were considered cardiac deaths. The 20- and 25-year survival rates were 93.7 +/- 2.5% and 90.9 +/- 3.6%, respectively. Reoperations were performed on six patients for residuae or sequelae without mortality or morbidity, and 90.4% +/- 3.1% of the patients were free from late death or reoperation at 20 years and 83.9 +/- 5.3% at 25 years. Thirty-one of the 46 female patients were married and 28 had children. Forty-three live births were confirmed without any association of a congenital heart anomaly. Employment status was satisfactory in most of the patients, and 81%-89% of the patients in this series were considered to have a good quality of life. Less than half the patients had late symptoms, and all were related to cardiac arrhythmias. Late ventricular arrhythmias remain the major concern of the future, and therefore, the establishment of effective pre- and intraoperative management to prevent postoperative arrhythmias is essential.

Adolescent↗
PubMed1993

Extracorporeal membrane oxygenation for severe heart failure after Fontan operation.

A 10-year-old boy with tricuspid atresia and Glenn anastomosis underwent a modified Fontan operation. After the operation, the pressure in the inferior vena cava increased, leading to oliguria and ascites. After the creation of continuity between the superior vena cava and the inferior vena cava to reduce the pressure gradient, there remained an elevated right atrial pressure. Six days of extracorporeal membrane oxygenation effectively stabilized his hemodynamics and organ function and allowed an excellent outcome.

Angiography↗
PubMed1993

Force and histochemical changes in rabbit pectoral muscle induced by chronic electrical stimulation for use in cardiac assistance.

Before the application of skeletal muscle in a cardiac-assist device, a preconditioning procedure is required in order to overcome the easy fatigability of this muscle. We evaluated the effect of preconditioning muscles while keeping their collateral blood supply. In 15 male rabbits, a skeletal muscle ventricle (SMV) was constructed from silicone and pectoralis major muscle with minimal dissection. In six rabbits, the muscle was electrically preconditioned. The pressure generated by the SMV was measured under various conditions. Histochemical fiber grouping was performed using myosin ATPase staining. The pressure rose with preconditioning despite an increase in slow-twitch fibers. The cross-sectional area of both slow-twitch and fast-twitch fibers increased significantly. The rise in pressure is attributable to muscle hypertrophy. The use of muscles with minimal dissection may avoid or shorten the vascular delay because of a well maintained blood supply and nearly isometric preconditioning.

Animals↗
PubMed1993

Endothelin subtype B receptors are coupled to adenylate cyclase via inhibitory G protein in cultured bovine endothelial cells.

We studied whether endothelin (ET) isopeptides have any effects on adenylate cyclase activity in cultured bovine endothelial cells (ECs). Both ET-1 and ET-3 dose-dependently inhibited cAMP formation stimulated by forskolin and isoproterenol, although the inhibitory effect of ET-1 was less potent than that of ET-3. In contrast, ET-1 and ET-3 almost equipotently inhibited forskolin-stimulated cAMP formation in bovine EC pretreated with phosphoramidon, a putative ET-1 converting-enzyme inhibitor. These data suggest that endothelial ETB receptors are functionally coupled to adenylate cyclase, possibly via Gi protein.

Adenylyl Cyclases↗
PubMed1993

Endothelin receptor subtype B mediates synthesis of nitric oxide by cultured bovine endothelial cells.

Endothelins (ET) produce endothelium-dependent vasodilation through nitric oxide (NO) synthesis. The present study was designed to elucidate the cellular mechanism by which ET induces synthesis and release of endothelium-derived NO by cultured bovine endothelial cells (EC). Binding studies revealed that bovine EC membrane had the binding sites of a novel agonist (BQ3020) for non-isopeptide-selective receptor subtype (ETB). Affinity labeling studies showed a major labeled band with the apparent molecular mass of 50 kD. Northern blot analysis demonstrated the expression of mRNA for ETB receptor. BQ3020 rapidly and dose dependently induced formation of inositol-1,4,5-triphosphate and increased intracellular Ca2+ concentrations in fura-2-loaded cells. Concomitantly, BQ3020 dose dependently stimulated production of both nitrate/nitrite (NOx) and cyclic GMP; a highly significant correlation existed between NOx and cGMP production. The stimulatory effect on NOx and cGMP production by ETB agonist was inhibited by NO synthase inhibitor monomethyl-L-arginine; this effect was reversed by coaddition of L-arginine, but not D-arginine. NOx and cGMP production stimulated by BQ3020 was inhibited by pretreatment with pertussis toxin. ETB agonist-induced NOx production was blocked by a calmodulin inhibitor and an intracellular Ca2+ chelator, but not by an extracellular Ca2+ chelator or a Ca2+ channel blocker. These data suggest that endothelins stimulate ETB receptor-mediated phosphoinositide breakdown via pertussis toxin-sensitive G-protein(s), which triggers release of intracellular Ca2+, thereby activating Ca2+/calmodulin-dependent NO synthase in EC.

Amino Acid Oxidoreductases↗
PubMed1993

Endothelin receptor subtypes are coupled to adenylate cyclase via different guanyl nucleotide-binding proteins in vasculature.

We have studied whether endothelin (ET) isopeptides have any effects on adenylate cyclase activity via different guanyl nucleotide-binding proteins (G-proteins) in cultured rat vascular smooth muscle cells (VSMC) and bovine endothelial cells (EC). Northern blot analysis clearly demonstrated gene expression of ETA receptors in VSMC and ETB receptors in EC. ET-1 dose-dependently (10(-9)-10(-6) M) stimulated cAMP formation in VSMC, whose effect was inhibited completely by ETA receptor antagonist (BQ-123) but not by indomethacin or quinacrine. The ET-1-induced cAMP formation was additive with isoproterenol but not with cholera toxin. In contrast, ET-3 and ETB receptor agonist (BQ-3020) dose-dependently (10(-9)-10(-6) M) inhibited forskolin-stimulated cAMP formation in EC, whose effect was completely abolished by pertussis toxin. Cholera toxin ADP ribosylated 45- and 52-kilodalton proteins in VSMC, whereas pertussis toxin ADP ribosylated the 41-kilodalton protein in EC. These data suggest that, in addition to phospholipase C via Gq, ETA and ETB receptor subtypes are functionally coupled to adenylate cyclase, possibly via Gs in VSMC and Gi in EC, respectively.

Adenylate Cyclase Toxin↗
PubMed1993

Cellular mechanism of natriuretic peptides-induced inhibition of endothelin-1 biosynthesis in rat endothelial cells.

We studied the cellular mechanism by which natriuretic peptides inhibit the synthesis and release of endothelin-1 (ET-1) in cultured rat aortic endothelial cells (EC). Atrial natriuretic peptide (ANP) and brain natriuretic peptide (BNP) showed dose-dependent and equipotent effects on displacement of [125I]ANP binding and generation of cGMP production in rat EC, whereas C-type natriuretic peptide and biologically inactive ANP analog had lesser effects. ANP and BNP as well as 8-bromo-cGMP had potent inhibitory effects on immunoreactive ET-1 release, the transient increase in the intracellular Ca2+ concentration, and the formation of inositol 1,4,5-trisphosphate stimulated by thrombin in rat EC. A cGMP-dependent protein kinase inhibitor (KT5823), but not a cAMP-dependent protein kinase inhibitor (KT5720), completely abolished the inhibitory effect of ANP on thrombin-induced immunoreactive Et-1 release. Northern blot analysis using cDNA for rat prepro-ET-1 as a probe showed that ANP and 8-bromo-cGMP, but not C-type natriuretic peptide, inhibited thrombin-induced prepro-ET-1 mRNA expression, whose effect was abolished by KT5823. These data suggest that ANP and BNP inhibit the thrombin-induced synthesis and release of ET-1 in cultured rat aortic EC by blocking phosphoinositide breakdown, possibly via natriuretic peptides type A receptor-mediated cGMP-dependent mechanism.

Animals↗
PubMed1993

Does recombinant human erythropoietin accelerate erythropoiesis for predonation before cardiac surgery?

This study was performed to determine the effect of recombinant human erythropoietin (rEPO) on preoperative autologous blood donation in patients undergoing elective coronary bypass or valvular operations. Nineteen patients received 200 u/kg of rEPO intravenously 3 times a week, and 210 mg/day of iron sulfate orally, for 2 weeks before surgery (EPO group). Seven matched patients only took the same dose of iron sulfate (control group). Bone marrow was aspirated from the sternum during surgery, and the Myeloids/Erythroids ratio was calculated in 13 patients of the EPO group. The total donated blood mass was 853 +/- 231 g in the EPO group, and 657 +/- 140 g in the control group (p < 0.05). The average increase in hemoglobin (Hb) mass from admission to the day before surgery was 87 +/- 33 g in the EPO group, and 24 +/- 13 g in the control group (p < 0.001). Furthermore, the logarithm of the ratio of "increased Hb mass/Hb mass at admission" was significantly correlated to the Myeloids/Erythroids ratio (r = -0.9130, p < 0.01). These results strongly indicate that rEPO is a very useful agent for predonation of autologous blood for cardiac operations.

Adult↗
PubMed1993

Sinus and atrioventricular nodal re-entrant tachycardia.

A case of a 42-year-old woman who had combined sinus and atrioventricular nodal tachycardia is reported. Programmed atrial stimulation study showed the induction of the two types of paroxysmal supraventricular tachycardia. The mechanisms of these supraventricular tachycardias were both sinus nodal and atrioventricular re-entrant tachycardia. Sinus nodal re-entrant tachycardia could be induced only after injection of atropine. The tachycardias could no longer be induced after the administration of verapamil.

Adult↗
PubMed1993

Direct thrombolytic revascularization of the occluded basilar artery.

Successful direct revascularization in a 54-year-old man with embolism of the basilar artery following St Jude Medical valve replacement for mitral regurgitation 6 years earlier is reported. He arrived at the hospital in a deep coma. Computed tomography showed no new lesions, but subsequent angiography revealed occlusion of the basilar tip, bilateral posterior cerebral arteries and right superior cerebellar artery. Direct thrombolytic therapy was performed using 420,000 units urokinase through an infusion catheter placed in the basilar artery. The patient immediately regained consciousness, with only slight diplopia. Direct thrombolytic therapy is considered to be an effective treatment for thromboembolism following prosthetic valve replacement in certain selected cases.

Basilar Artery↗