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Minoru Ono

Publications and source records attributed to Minoru Ono.

33 records · Page 2Linked to original sources
PubMed2004

[The effects of Na+ -H+ exchange inhibitor, KB-R9032, administered at the time of reperfusion in perfused rat heart].

BACKGROUND: We have reported that pretreatment with KB-R9032, a newly developed Na+ -H+ exchange inhibitor is protective against reperfusion-induced ventricular arrhythmia in the isolated perfused rat heart. This study was conducted to elucidate whether the drug is equally effective when it is given at the time of reperfusion. METHODS: Male Wistar rat hearts (n=32, 16 for each group) were perfused by means of Langendorff technique. Each heart was subjected to regional ischemia (occlusion of the left anterior descending coronary artery for 11 minutes) and to three minutes of reperfusion (release of the occlusion). KB-R9032 4 mg (one shot group) or a vehicle without drug (control) were given 30 seconds before the reperfusion to 30 seconds after the reperfusion. RESULTS: In the control group reperfusion-induced ventricular fibrillation (VF) occurred in 91.7% and the duration was 165 +/- 14.4 seconds, but, in one shot group, the incidence of VF decreased to 6.3% and the duration of VF was reduced to 0.4 +/- 0.4 seconds, respectively (P<0.05 vs control group). CONCLUSIONS: It has been shown in this study that the Na+/H+ exchange inhibitor KB-R9032 given at the time of reperfusion suppresses reperfusion arrhythmias in the ischemia-reperfusion model of isolated rat heart.

Animals↗
PubMed2003

Inhibition of Na(+),K(+)-ATPase by the extract of Stephania cephararantha HAYATA and bisbenzylisoquinoline alkaloid cycleanine, a major constituent.

The Stephania cephararantha HAYATA extract, and its constituent bisbenzylisoquinoline alkaloids, such as cycleanine, cepharanthine, isotetrandrine, berbamine, homoaromoline, and cepharanoline were studied for effects on Na(+),K(+)-ATPase activity. The S. cephararantha HAYATA extract inhibited Na(+),K(+)-ATPase activity with an apparent IC(50) value of 540 microg/mL. Cycleanine markedly inhibited Na(+),K(+)-ATPase activity with an IC(50) value of 6.2 x 10(-4)M. It slightly inhibited Mg(2+)-ATPase, H(+)-ATPase, and Ca(2+)-ATPase. No effects on alkaline and acid phosphatase activities were observed. The inhibition by isotetrandrine, homoaromoline, cepharanthine, and berbamine was less marked, and cepharanoline showed no effect. Five synthetic analogues of cepharanthine slightly inhibited the activity. The mechanism of inhibition by cycleanine on Na(+),K(+)-ATPase activity was examined in detail, and the following results were obtained in the overall reaction: (1) the mode of inhibition was noncompetitive with respect to ATP; (2) the degree of inhibition was decreased with a decrease of K(+) concentration; (3) it was not affected by Na(+) concentration; (4) the inhibition mechanism was different from that of ouabain. The activity of K(+)-dependent p-nitrophenyl phosphatase, a partial reaction of Na(+),K(+)-ATPase, did not appear to have been inhibited by cycleanine in the reaction mixture containing 15 mM K(+) (optimum condition). However, cycleanine increased the K(0.5) value for K(+) and reduced the K(i) values for Na(+) and ATP, in K(+)-dependent p-nitrophenyl phosphatase. Cycleanine might interact with the enzyme in Na.E(1)-P form and prevents the reaction step from Na.E(1)-P to E(2)-P.

4-Nitrophenylphosphatase↗
PubMed2003

Rupture of a small fusiform thoracic aortic aneurysm.

We report a case of ruptured aortic aneurysm of the distal aortic arch. This aneurysm was fusiform and only 4.0 cm in maximum diameter. Emergency total aortic arch replacement was successful. Rupture of a thoracic aortic aneurysm of this shape and size is possible but extremely rare.

Aged↗
PubMed2003

Two cases of anomalous origin of LAD from right coronary artery requiring coronary artery bypass.

We experienced two cases with anomalous origin of the left anterior descending artery (LAD) from the proximal right coronary artery requiring coronary artery bypass grafting. A 66-yr old female with a long history of angina and a positive stress test had the anomalous artery coursing anterior to the right ventricular outflow tract. A 42-yr old male with worsening angina after an anteroseptal myocardial infarction had the anomalous artery running between the great vessels. Both patients underwent left internal mammary artery-to-LAD bypass on the beating heart with complete resolution of ischemic symptoms. Isolated coronary artery anomaly is an uncommon disease (0.6-1.2%) in patients undergoing cardiac catheterization. An anomalous origin of the LAD from the proximal right coronary artery (RCA) or the right sinus of Valsalva (RSV) is very rare, found in 1.2-6.1% of all coronary anomalies. This coronary anomaly has been considered potentially serious but functionally unimportant. We report two cases of anomalous LAD from the proximal RCA resulting in anterior wall ischemia which was effectively treated by coronary artery bypass surgery.

Adult↗
PubMed2003

Recurrent embolism caused by floating thrombus originating from the ligamentum arteriosum.

Few patients with an embolism derived from apparently normal thoracic aorta with no other disease have been reported. We were presented with a case of a floating thrombus originating from the ligamentum arteriosum that caused multiple embolic episodes in the bilateral common iliac and superior mesenteric arteries. From our findings, we recommend a surgical approach for a floating thrombus in the aorta to prevent further embolism.

Adult↗
PubMed2003

Development of a liquid culture system for megakaryocyte terminal differentiation: fibrinogen promotes megakaryocytopoiesis but not thrombopoiesis.

Megakaryocyte differentiation is composed of three distinct stages: formation of erythromegakaryocytic progenitor cells, maturation of megakaryocytes and production of platelets. We have developed a liquid culture system for megakaryocyte terminal differentiation from haematopoietic stem cells into proplatelets. In this system, CD34+ cells isolated from human cord blood, differentiated to CD41+ cells, were classified either as propidium iodide (PI)+ cells (large) or PI- cells (small) by fluorescence-activated cell sorting analysis on the late-stage CD41+ cells. Transmission electron microscopy showed that the cultured small cells were morphologically identical to platelets isolated from normal peripheral blood. Moreover, the number of differentiated cells that were CD42b-positive attained an approximately 60-fold expansion over that of the primary CD34+ cells in this culture system. Furthermore, gene expression of megakaryocytopoietic transcriptional factors, GATA-1 and NF-E2, and several megakaryocytic markers such as glycoprotein (GP)IIb and thromboxane synthase was observed in the individual differentiation stage. Treatment with fibrinogen, a ligand of GPIIb/IIIa, increased the number of CD41+/PI+ cells, but treatment in the late stage suppressed CD41+/PI- cell formation, suggesting that fibrinogen promotes megakaryocytopoiesis, but not thrombopoiesis. We conclude that this liquid culture system using human CD34+ cells may be used to mimic the physiological development from haematopoietic stem cells into megakaryocytes, as well as promote subsequent thrombopoiesis.

Antigens, CD34↗
PubMed2003

Lung cancer associated with diffuse pulmonary fibrosis: CT-pathologic correlation.

The authors reviewed the computed tomographic (CT) scans and pathologic specimens of 57 histologically proved bronchogenic carcinomas (35 squamous cell carcinomas, 12 small cell carcinomas, and 10 adenocarcinomas) in 47 patients with diffuse pulmonary fibrosis. The patients ranged in age from 61 to 87 years (mean age, 72 years; 42 men and 5 women). On radiography and CT, most tumors (82%) were located in peripheral areas of honeycomb lung. In 50 of the 57 lesions, the tumors were round or lobulated with sharp margins. In seven tumors, including six squamous cell carcinomas and one small cell carcinoma, the tumor invaded the adjacent honeycomb lung and lacked distinct margins. Intratumor lucency was seen in 13 tumors (five solitary and eight multiple). The CT findings, including high-resolution CT scans, were compared with the histologic findings in a subgroup of 29 lesions in 25 patients with available surgical or autopsy specimens. Invasive growth of tumors with unclear margins (four lesions), septal thickening of the contiguous/surrounding honeycombed areas (16 lesions), and discrete masses (nine lesions) with solitary (four of nine) or multiple (five of nine) intratumor lucencies. The lucencies in six of nine patients (67%) with intratumor lucencies were found to represent engulfed cystic airspaces histologically. CT revealed that bronchogenic carcinoma associated with diffuse pulmonary fibrosis has distinct morphologic characteristics that correlate histologically with a specific pattern of tumor growth.

Aged↗
PubMed2003

Radiologic features of Castleman's disease occupying the renal sinus.

OBJECTIVE: Our purpose was to describe the radiologic findings in five abnormalities in three patients with Castleman's disease occupying the renal sinus. CONCLUSION: Common findings such as mild homogeneous enhancement passing through the mass of the collecting system with mild hydronephrosis on contrast-enhanced CT and hypointense signal on T2-weighted images were obtained. Castleman's disease may be considered in a differential diagnosis of a mass occupying the renal sinus, although it is difficult to differentiate from malignant lymphoma.

Aged↗
PubMed2002

Left ventricular pseudoaneurysm late after mitral valve replacement.

We report an unusual case of left ventricular pseudoaneurysm late after mitral valve replacement. A 60-year-old woman, who had undergone aortic and mitral valve replacement using mechanical prostheses 4 months previously, presented with severe congestive heart failure. The computed tomographic scan of the chest demonstrated a large mass displacing the heart anteriorly. The orifice of the pseudoaneurysm was successfully closed on the beating heart using partial femorofemoral bypass through a left thoracotomy.

Aneurysm, False↗
PubMed2002

Open stent-grafting for aortic arch aneurysm is associated with increased risk of paraplegia.

BACKGROUND: Open surgery using the endovascular stent-graft is a novel technique that lessens the invasiveness of surgery for the aortic arch. However, the outcome of this procedure remains uncertain. METHODS: Between November 1996 and July 2000, a total of 19 patients underwent open surgery using an endovascular stent-graft for thoracic aortic aneurysms. There were 15 men (78.9%) and 4 women (21.1%). Patient age ranged from 29 to 82 years (mean 69.3 years, median 74 years). Atherosclerotic thoracic aortic aneurysms were present in 17 patients (89.4%) and aortic dissection in 2 patients (10.5%). RESULTS: Two patients (10.5%) died in the hospital and 4 patients (21.1%) presented with paraplegia postoperatively. Among the 4 patients with postoperative paraplegia, 1 case was complicated with intraoperative aortic dissection. The other 3 patients with paraplegia had spinal cord ischemic time of more than 60 minutes and intraoperative body weight gain of more than 4 kg. Of these 3 patients, hemodynamic instability after cardiopulmonary bypass was observed in 1 patient and cholesterin embolus in the anterior spinal artery was found at autopsy in another. On univariate analysis, age greater than 75 years was the only risk factor associated with paraplegia (p < 0.05). Autopsy findings for the 2 patients showed that the Adamkiewicz arteries were not blocked by the stent-graft in either patient. CONCLUSIONS: Intraoperative aortic dissection, embolization of the intercostal arteries, long ischemic time of the spinal cord, and excessive weight gain during operation may have been associated with the high incidence of paraplegia after open surgery using the endovascular stent-graft.

Adult↗
PubMed2002

Short- and long-term results of open heart surgery in patients with abdominal solid organ transplant.

OBJECTIVES: Cardiac disease is a common cause of mortality and morbidity in patients with abdominal solid organ transplant. Improvement of the results of abdominal organ transplantation has contributed to an increasing pool of patients who require open heart surgery. We investigated short- and long-term results of open heart surgery in patients with functioning abdominal solid organ transplants. METHODS: We retrospectively examined 60 patients (52.5 years in average) undergoing coronary artery bypass grafting and/or valve surgery since July 1988 after abdominal organ transplantation. There were 22 females (37%). They consisted of 46 kidney, nine kidney-pancreas and five liver recipients. Cardiac surgery was performed 68.9 months after transplantation. Preoperative serum creatinine level was 2.1 mg/dl, and 11 patients (18%) had creatinine level more than 3.0 mg/dl. Eleven patients (18%) were operated upon on non-elective basis. Twelve patients (20%) were not given stress-dose steroids postoperatively. RESULTS: Three patients died early after surgery (5.0%). Twenty-six major complications were seen in 17 patients (28%), including deterioration of renal function in seven (three patients required temporary hemodialysis), three major infections, two bleeding complications, and two strokes. No graft loss was encountered. No differences were seen in mortality and morbidity between patients with or without stress-dose steroids. Multivariate analysis identified cardiopulmonary bypass time (P<0.05) as a risk factor for operative death, preoperative creatinine level (P<0.05), cardiopulmonary bypass time (P<0.05) and the amount of fresh frozen plasma used (P<0.05) for major complication, non-elective surgery (P<0.01) for deterioration of renal function. Thirteen patients died and five kidney allografts failed late after surgery. Three- and 5-year patient and graft survivals were 70.8 and 66.8, 84.5 and 84.5%, respectively. Multivariate regression analysis identified female gender (P<0.05), body mass index (P<0.001) and non-elective surgery (P<0.001) as risk factors for late death, and preoperative creatinine level (P<0.05) for late graft loss. CONCLUSIONS: Open heart surgery can be performed with acceptable short- and long-term results in patients with functioning abdominal transplants. Stress-dose steroid may be unnecessary in selected patients. Aggressive use of open heart surgery in this patient population to avoid non-elective surgery may further improve early and late surgical outcomes.

Adult↗
PubMed2002

Early experience of coronary artery bypass grafting with a new self-closing clip device.

OBJECTIVE: We are in the midst of development of several new anastomotic devices for use in coronary artery bypass grafting surgery. This study was designed to examine one of these devices (a new self-closing clip) for left internal thoracic artery-left anterior descending coronary artery anastomosis. Its feasibility and the quality of anastomosis were evaluated. METHODS: Fourteen patients who underwent first-time elective coronary artery bypass surgery were enrolled between July and December 2000. The left internal thoracic artery was anastomosed to the left anterior descending coronary artery in an interrupted manner with Coalescent U-clips (Coalescent Surgical, Inc, Sunnyvale, Calif). Immediate patency was checked with a transit-time flowmeter. Selective angiography was performed 6 months after surgical intervention. RESULTS: Five patients underwent on-pump coronary bypass grafting, 9 on the beating heart. One patient was excluded from the study intraoperatively because of a poor target site necessitating a 2-cm-long anastomosis. Left internal thoracic artery-left anterior descending artery anastomoses were created with an average of 11.8 clips in 15.9 minutes. Mean graft flow was 45.6 mL/min. Neither conversion to standard suture technique nor revision of anastomosis was necessary. There tended to be a learning curve in the anastomosis on the beating heart. Postoperative lengths of stay in the intensive care unit and the hospital were 20.7 hours and 3.9 days, respectively. Neither death nor major complication was seen, except for temporary atrial fibrillation in 2 patients. Graft patency at 6 months was 100% (FitzGibbon grade A). CONCLUSION: Left internal thoracic artery-left anterior descending artery anastomoses can be created safely and effectively with new self-closing clips on the beating, as well as the arrested, heart. Midterm patency was shown to be perfect by means of angiography.

Adult↗
PubMedDate not supplied

Beating heart coronary artery bypass surgery after orthotopic heart transplantation.

Beating-heart coronary artery bypass surgery was performed in a 52-year-old man with accelerated transplant coronary artery disease 10 years after orthotopic heart transplantation. Transplant coronary artery disease was first detected in the left circumflex coronary artery 9 years after transplantation. Rapid progression to triple vessel disease occurred within 1 year, and the patient developed worsening symptoms of shortness of breath and chest pain. He underwent off-pump "beating heart" left internal mammary artery to left anterior descending coronary artery bypass surgery. The circumflex coronary artery was not graftable due to diffuse and truncated small vessel disease. His postoperative course was uneventful and he was discharged on the fifth postoperative day. Coronary angiography 3 months after the surgery revealed a widely patent left internal mammary artery to left anterior descending artery bypass. He is alive and symptom free more than 1 year after his surgery.

Coronary Disease↗
PubMedDate not supplied

Unilateral proximal interruption of the pulmonary artery in adults: CT findings in eight patients.

PURPOSE: The authors retrospectively reviewed CT findings of unilateral proximal interruption of the pulmonary artery in eight adults. METHODS: Patient age ranged from 23 to 65 years (mean, 44 years), and three men and five women (six left-side affected and two right-side affected) comprised the study group. High resolution CT was obtained in five patients. Associated anomalies of great vessels included five cases of right aortic arch and one tetralogy of Fallot. RESULTS: On the affected side, complete defects of pulmonary arteries were seen in all patients. CT revealed serrated pleural thickening in six patients (75%), subpleural parenchymal bands in five (63%), and mosaic attenuation in three (38%) on the affected lung. Dilatation of bronchial arteries in five patients (71%), internal thoracic arteries in four (57%), and intercostal arteries in three (43%) were also seen. As for other parenchymal changes, cystic bronchiectasis and honeycombing were seen in two (25%) respective cases. On the unaffected lung, mosaic attenuation was seen in four (50%) patients. CONCLUSIONS: The main manifestations of unilateral proximal interruption of the pulmonary artery were complete defects of pulmonary arteries, enlarged bronchial arteries, and formed pleural thickening or some parenchymal changes of the lung.

Adult↗