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Biomedical subjects

K Kosuga

Publications and source records attributed to K Kosuga.

At least 109 records · Page 6Linked to original sources
PubMed1991

Calmodulin-independent nitric oxide synthase from rat polymorphonuclear neutrophils.

Recently, the purification of nitric oxide synthase (EC 1.14.23) from rat cerebellum has been reported, and the enzyme is a calmodulin-requiring enzyme (Bredt, D. S., and Snyder, S. H. (1990) Proc. Natl. Acad. Sci. U. S. A. 87, 682-685). In this paper, nitric oxide synthase has been purified to near homogeneity from the cytosol fraction of rat polymorphonuclear neutrophils. The purification procedure involves affinity chromatography with adenosine 2',5'-diphosphate-agarose and an anion exchange column, DEAE-Bio-Gel A. On polyacrylamide gel electrophoresis in sodium dodecyl sulfate, the enzyme migrated as a single protein band with Mr = 150,000. The molecular weight was estimated to be 150,000 by gel filtration on a Superose 12 HR 10/30. The purified enzyme was unstable with a half-life of 3 h at pH 7.4 and 4 degrees C. The enzyme activity required the presence of Ca2+, NADPH, FAD, and (6R)-5,6,7,8-tetrahydro-L-biopterin. Calmodulin antagonists (W5, W7, W13, and trifluoperazine dihydrochloride) did not inhibit the enzyme activity, and the addition of calmodulin was also ineffective for the increase in the enzyme activity. The neutrophil enzyme appears to be a calmodulin-independent type of nitric oxide synthase.

Amino Acid Oxidoreductases↗
PubMed1991

Primary anastomosis for acute ascending aortic dissection.

Intimal tear resection and primary anastomosis of the aorta were used for the treatment of eight patients with DeBakey I and II type acute aortic dissection. Five patients were of DeBakey I type, and three patients were of the II type. Moderate or severe aortic regurgitation (AR) was observed in six of eight patients. The site of the intimal tear was diagnosed by intraoperative echocardiography, and the adventitia corresponding to the intimal tear was transversely opened under total cardiopulmonary bypass. While resuspension of the aortic valve was performed on only one of six patients, AR disappeared in four, postoperatively. Two of eight patients died early postoperatively. The cause of death was postoperative cardiac tamponade in one patient and cerebral herniation in the remaining one. The other six patients have been observed for a mean period of 27 months. There is no late death, and they show no dilatation of the aortic root and deterioration of AR. We believe that this operative method is a simple and safe emergency procedure for DeBakey I and II type acute aortic dissection.

Acute Disease↗
PubMed1991

Reoperation following total repair of congenital heart disease.

For the past 25 years we have performed 61 reoperations in 58 patients with congenital heart disease who previously underwent total correction for the diagnosed ventricular septal defect, tetralogy of Fallot, atrioventricular septal defect, atrial septal defect, total anomalous pulmonary venous connection (TAPVC), and other involvement for 27, 11, 5, 4, 4, and 7 patients, respectively. Causes of reoperation included 43 events of valvular lesion, 29 of residual septal defect, 5 of conduit failure, 5 of venous obstruction, 3 of hemolysis, 3 of infective endocarditis, and 2 of prosthetic valve dysfunction. Although 5 early and 4 late deaths were encountered, the remaining 49 patients (3 in New York Heart Association (NYHA) Class II and 46 in NYHA class I or II) survived the reoperation. The patients were followed up by echocardiography and chest X-ray examination, and reoperation was indicated under the following conditions: moderate to severe valvular insufficiency; residual defect causing the shunt ratio to be over 30% or a systolic pulmonary pressure over 50 mmHg; or a high pressure gradient over 50 mmHg across the right ventricular outflow tract. Early timing for reoperation seemed to be important in patients with pulmonary venous obstruction, prosthetic dysfunction, severe hemolysis and infective endocarditis.

Adolescent↗
PubMed1991

Cytosolic and membrane-bound nitric oxide synthase.

Cytotoxic activated macrophages were sonicated and centrifuged. The activity of nitric oxide (NO) synthase was present in the supernatant and independent of Ca2+. The pellets were washed three times and treated with buffer containing 0.1% Triton X-100 or buffer alone, followed by centrifugation. The supernatant containing Triton X-100 showed NO synthase activity that was dependent on Ca2+, whereas the supernatant without the detergent had little activity. These data suggest that there are two forms of NO synthase: cytosolic and membrane-bound enzymes.

Amino Acid Oxidoreductases↗
PubMed1991

Reoperation for acquired valvular heart disease--operative method and surgical results.

Between January, 1982 and December, 1989, 102 reoperations (repeat median sternotomy) in 101 patients with valvular heart disease were performed at Kurume University Hospital. In these operations, the heart was not mobilized from the pericardium to prevent tearing the heart or great vessels. All operative procedures were performed through the pericardium which adhered tightly to the heart. Adequate left ventricular hypothermic protection was obtained without total dissection of the heart by cold crystalloid cardioplegic solution and topical cooling which was accomplished by filling the left pleural space with cold saline during the operation. As to the surgical results, the early mortality rate was 4.0%, and the late mortality rate was 5.2%. The causes of death were not related to the operative procedures or perioperative myocardial protection. There was no significant difference in the early mortality rate between the reoperations and the initial operations. These results suggest that reoperation for valvular heart disease should be performed before the hemodynamic condition of the patient deteriorates.

Adult↗
PubMed1991

An evaluation of long-term results over 10 years after intracardiac repair of tetralogy of Fallot.

A follow-up study was conducted of 166 patients who had survived for more than 10 years after total correction of tetralogy of Fallot. The total number of patients in NYHA class I was 141 (85%); the other 25 patients had been medically treated or had followed a prudent life style. The factors which caused postoperative symptoms were residual lesions and ventricular arrhythmia. Ultrasonic echocardiography showed that among 72 patients with transannular patch, 68 (95%) showed moderate or severe pulmonary incompetence. There was a correlation of gamma = 0.43 between the severity of pulmonary incompetence and cardiothoracic ratio in the 48 patients without any residual lesions, while two cases with severe pulmonary incompetence showed obvious right ventricular failure. Ambulatory ECG monitoring was employed to study 53 patients. As a result, 21 patients were found to present solitary moderate or severe pulmonary incompetence, while premature ventricular contraction of Lown's grade 4A was seen in nine patients (42.9%). In conclusion, it is considered essential to carefully follow up patients after intracardiac repair of tetralogy of Fallot, especially those with severe pulmonary incompetence.

Adolescent↗
PubMed1991

Anomalous origin of the right coronary artery associated with congenital bicuspid aortic valve.

Anomalous origin of the right coronary artery is an infrequent anomaly. A case with anomalous origin of the right coronary artery from the ascending aorta above the left sinus of Valsalva is described. This patient was also found to have a bicuspid aortic valve. The aortic valve was markedly calcified and stenotic. The aortic valve was replaced with a St. Jude Medical prosthesis.

Aortic Valve↗
PubMed1991

[Percutaneous transluminal angioplasty of a constricting coronary artery bypass graft: a case report].

A case with percutaneous transluminal coronary angioplasty (PTCA) for the stenosis of saphenous vein bypass graft was reported. A 68-year-old woman developed repeated effort angina two months after emergency triple CABG. Coronary angiographic study revealed 90% stenotic lesion in a sequential vein graft which was located between proximal and distal OM. PTCA was successful to dilate the stenotic lesion from 90% to 25% narrowing. She has been free from angina after the CABG and PTCA.

Aged↗
PubMed1991

[Coronary artery bypass grafting combined with operation for non-cardiac disease].

During the last two years and six months, ten patients underwent operation for both coronary artery disease and non-cardiac surgery. There were six patients with vascular disease, three with gastric cancer and one with cholelithiasis. Six patients had simultaneous operation of both coronary artery bypass grafting (CABG) and non-cardiac surgery, and four underwent non-cardiac surgery mean of 105 days after CABG. The number of significant lesions of coronary artery in patients with simultaneous or two-staged operation was 2.2 +/- 0.8 or 2.8 +/- 0.5 per patient, respectively. The operative time in patients with simultaneous operation was 361 +/- 49 minutes. However, in patients with staged operation the time for cardiac surgery was 380 +/- 36 minutes and the time for non-cardiac operation was 388 +/- 83 minutes. There were no patients with complications after either cardiac or non-cardiac operation. In patients having surgical indications for both coronary artery and non-cardiac diseases, CABG should be performed prior to the non-cardiac surgery. In patients with normal cardiac function and sufficient operative time after CABG, concomitant operation seemed to be recommended. In case with advanced malignant disease or incompetent cardiac function, staged operation would be selected for good surgical result.

Aortic Aneurysm↗
PubMed1991

[Surgical treatment of acute ascending dissection--a simplified operative method].

Primary anastomosis for acute ascending aortic dissection was performed in 8 patients. Primary anastomosis included resection of the intimal tear where applicable, a circumferential suture line in the ascending aorta at the site of the tear, and wrapping of the anastomosis of the ascending aorta with Dacron vascular prosthesis. The aortic valve was resuspended in 1 of 6 patients associated with aortic regurgitation. In 4 patients, aortic regurgitation disappeared postoperatively. Two patients show minor non-progressive valve regurgitation. Two of 8 patients died early postoperatively. There was no late death and dilatation of the aortic root in the follow-up period of mean 27 months. On the basis of these results, we believe that primary anastomosis is a simpler and safer operative method for acute dissection of the ascending aorta.

Acute Disease↗
PubMed1991

[Surgical treatment of the aortic arch dissection--a report of two cases operated by partial brachiocephalic perfusion, and open aortic anastomosis].

Two patients underwent aortic arch replacement for the dissecting aneurysm of the aorta using a simplified cardiopulmonary bypass (CPB) technique with partial brachiocephalic perfusion, moderate systemic cooling (22 degrees to 23 degrees C), and open aortic anastomosis were reported. The partial brachiocephalic perfusion was accomplished by perfusion to the right axillary artery using separate pump. Open distal anastomosis was performed under low flow hypothermic perfusion of the lower body during selective perfusion to the brain. Cardiopulmonary bypass and partial brachiocephalic perfusion time were 170 minutes, and 30 minutes in one case, and 207 minutes, 56 minutes in the other case. Both patients survived operations, and there were no postoperative strokes, and neurological complications. On the basis of these results, we discussed about supportive methods for aortic arch surgery.

Anastomosis, Surgical↗
PubMed1991

[Ten years experience with the St. Jude Medical valve prosthesis for mitral valve replacement].

During the 10-year period between 1980 and December 1989, isolated mitral valve replacement (MVR) with the St. Jude Medical (SJM) valve prosthesis was performed on 404 patients at our hospital, and a long-term postoperative follow-up was conducted. There were 161 males and 243 females ranged in age from 1 year to 73 years. Early operative mortality was 5.2%. Follow-up period for 383 patients who discharged from the hospital was 1970.7 patient-years. Twenty of these patients died during the follow-up period, and a late mortality rate was 5.2%. During 10 years, thromboembolic event occurred in 8 patients. Four patients had anticoagulant-related bleeding, 4 had paravalvular leak, and 5 underwent re-operations. There was neither structural valve failure nor prosthetic valve endocarditis. Therefore, the actuarial survival rate and the valve-related death-free rate at 10 years were 83.2%, and 96.8%. Of the patients who survived, New York Heart Association class improved significantly (93% in classes II and III preoperatively and 71% in class I postoperatively). Linearized rates for thromboembolism, anticoagulant-related bleeding, and hemolysis were 0.41%, 0.20% and 0.36%/100 patient-years, respectively. The actuarial estimate of incidence free from all complications was 92.0% at 10 years. On the basis of this 10 years' experience, we believe that the SJM valve prosthesis is an excellent mechanical prosthesis for mitral valve replacement, in terms of hemodynamic performance and low thrombogenicity in patients receiving anticoagulants.

Adolescent↗
PubMed1991

[Cardiovascular surgery in patients seventy years of age and older].

During 10 years between 1981 and 1990 surgical treatment was performed in 77 elderly patients (emergency 19) for cardiovascular disease at the 2nd Dept of Kurume Univ. Hospital. The 58 elective patients were studied. There were CABG in 29; valve replacement in 18; aneurysm operation in 11. The control patients were consisted of CABG in 60; valve replacement in 40; and aneurysm operation in 20 patients whose age were under 60 years. In the elderly group, operative mortality was 3 in 58 (5.2%) and there were no significant differences compared to that in the control patients. However, low output syndrome or respiratory complication was relatively prevented in the elderly patients and careful post operative management was required. The late results in the elderly patients NYHA or exercise tolerance was improved well. The 5 years actuarial survival rate was 93.3% in ischemic heart disease group, 87.7% in valvular heart disease group, and 90.0% in thoracic aneurysm group. No significant difference was seen compared to these results in control patients and no significant differences among these diseases.

Age Factors↗
PubMed1991

[A case report of atrial septal defect with quadricuspid pulmonary valve].

We reported the successful case of valvuloplasty on the quadriscuspid pulmonary valve which had pulmonary regurgitation. A 38-year-old woman was admitted with the complaint of palpitation. Atrial septal defect and pulmonary regurgitation were revealed preoperatively by the cardiac catheterization and doppler echocardiography. The malcoaptation of the pulmonary valve and pulmonary dilatation were diagnosed in echocardiography. At operation, the pulmonary valve was found quadricuspid and each cusp was same in size. The patient underwent the valvuloplasty on the abnormal cusps and the remarkable improvement of the coaptation was examined postoperatively. The patient had good clinical course for three years after operation.

Adult↗
PubMed1991

[Surgical treatment of cancer of the biliary tract and gall bladder].

With the advances in various kinds of diagnostic methods and improvement of operative technique, operations for cancer in biliary tract have recently increased, however, the prognosis has been unsatisfied. During the past 25 years, 495 cases with carcinoma of biliary tract (ca of gall bladder 175 cases, ca of bile duct 201, and ca of papilla vater 105) were operated. The resectability rate was 66% (62% in gall bladder, 62% in bile duct, 84% in papilla vater). Among the lesions in bile duct, the resectable rate in lower bile duct was better than the other site in bile duct. The late results in ca of bile duct, especially in the lesion of upper bile duct were still poor, however, the 5-years survival rate in ca of gallbladder or papilla vater carcinoma was 61% or 56%, respectively. For the further improvement of the surgical results, the sufficient resection of the intrahepatic bile duct in ca of bile duct should be performed, and in gall bladder carcinoma when tumor extends into the neck of gall bladder, bile duct should be resected. In advanced carcinoma, the appropriate hepatectomy or bile duct resection should be considered in proportion to the operative influence and the extension of the tumor.

Biliary Tract Neoplasms↗
PubMed1990

Stabilizing factor(s) of nitric oxide (NO) synthetase.

We found that the cytosol of rat peritoneal polymorphonuclear neutrophils contains factor(s) that can stabilize an unstable enzyme, nitric oxide synthetase, in the cytosol. This enzyme has been purified to a single protein from the cytosol. Its half-life was 3 hours at 4 degrees C and was prolonged to greater than 24 hours by the stabilizing factor in the cytosol. The molecular weight of the stabilizing factor was greater than 100,000. Its activity was lost by the treatment with heating or alkali for 1 min or with acid for 5 min. It did not adhere to the carboxymethyl or diethylaminoethyl column at neutral pH. This stabilizing factor(s) may play a role in the regulation of the nitric oxide synthetase.

Amino Acid Oxidoreductases↗