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Biomedical subjects

T Isomura

Publications and source records attributed to T Isomura.

At least 127 records · Page 7Linked to original sources
PubMed1990

Ultrastructural alterations of right and left ventricular myocytes in tetralogy of Fallot.

We examined the ultrastructure of right and left ventricular myocardial biopsies obtained prior to cardiopulmonary bypass in fourteen patients undergoing total correction of tetralogy of Fallot (TOF). Twelve patients were undergoing primary one-stage repair and two patients had had a previous Blalock-Taussig shunt operation. The ages of the patients ranged from 3 to 35 years. In left ventricular (LV) myocytes, the sarcolemma often formed pouches filled with mitochondria and the muscle fibers showed a disoriented arrangement. In addition, the myofibrils showed hypercontraction and the Z-bands were thickened; the degree of the myofibril contraction was more severe than that in right ventricular (RV) myocytes. These ultrastructural findings are similar to those observed in myocytes under hypoxic conditions. The number of lysosomes in LV myocytes, but not in RV myocyte increased in the older patients. While we have not established a causal relationship between the ultrastructural findings and clinical features in our cases, our observations are consistent with the possibility that early total correction of TOF may be required to prevent the development of hypoxic changes and degeneration of heart muscle.

Adolescent↗
PubMed1990

[Late postoperative results after repair of tetralogy of Fallot].

Two hundred and eighty two survivors after complete correction of tetralogy of Fallot were analyzed in late follow up periods. The method of the reconstruction of right ventricular outflow tract was non-transannular path (NTAP) in 110 patients and transannular patch in 172. In the group of TAP, pulmonary regurgitation occurred in all and the cardio-thoracic ratio was larger than the ratio in the group of NTAP (p less than 0.05). Postoperative ECG at rest showed complete right bundle branch block (CRBBB) in 224 patients and 6 of them showed sudden death in their follow up period. However, there were no sudden deaths in 41 patients without CRBBB. The rate of reoperation after intracardiac repair was 4.25% and the causes were residual pulmonary stenosis and residual ventricular septal defect, and there were no significant differences of the reoperation rate between NTAP-group and TAP-group.

Adolescent↗
PubMed1990

[Combined operation for renovascular hypertension and ischemic heart disease].

We have experienced two patients of ischemic heart disease associated with renovascular hypertension. Patient 1 (60-year-old man) underwent LV aneurysmectomy and triple aortocoronary bypass grafting (saphenous vein to diagonal branch, left internal mammary artery to obtuse marginal branch, and right gastroepiploic artery to right coronary artery). Seventy five days after the initial cardiac surgery endarterectomy for the left renal artery and bifurcated Dacron graft implantation for the iliac artery obstruction were performed. Patient 2 (62-year-old woman) underwent simultaneous operation of both right nephrectomy and triple aortocoronary bypass grafting (saphenous vein grafts to obtuse marginal branch and right coronary artery, and left internal mammary artery to left anterior descending artery). Their postoperative courses were uneventful except unstable and high blood pressure for four to seven days after the operation. It appears that it should be decided to achieve either simultaneous or two stage approach for ischemic heart disease associated with renovascular hypertension based on the preoperative cardiac function. And both postoperative cardiac function and hypertension should be carefully managed until the blood pressure becomes stable after the surgery.

Coronary Artery Bypass↗
PubMed1989

[Clinical study of the effect to myocardial protection with crystalloid cardioplegic solution during open heart surgery in infants under age 3 months].

We investigated the effect to myocardial protection with crystalloid cardioplegic solution (Kurume solution I (S-I)) during open heart surgery in 21 infants less than 3 months old. The mortality was 28.6% (6 cases) including 2 patients having peroperative severe acidosis or shock. It was suggested that about half of them died of inadequate myocardial preservation. Comparing factors in the deaths with the survivors, there were significant differences between them in extracorporeal circulation time (ECCT) (196.7 +/- 50.1 min versus 133.2 +/- 45.8 min, p less than 0.01) and aortic-cross clamping time (ACCT) (120.0 +/- 45.8 min versus 78.3 +/- 30.5 min, p less than 0.05). In survivors, 86.7% of them required the effective dose (more than 6 micrograms/kg/min) of catecholamine and 33.3% presented low cardiac output syndrome (with the dose of more than 10 micrograms/kg/min and more than for 48 hours). The incidence of LOS was related to ECCT and ACCT. Thus it seemed that infant was more susceptible than older patient to the effects of ECC and the operation was carried out safely with ECCT less than 150 minutes and ACCT under age 3 months, it is necessary to use the cardioplegic solution fitting immature myocardium and to design operative technique and assist device for open heart surgery to shorten ECCT and ACCT.

Cardiac Surgical Procedures↗
PubMed1989

[Surgery for aortic aneurysms with coronary disease].

Between 1981 and 1988, 52 patients with dissecting aneurysms were operated and four of them (7.7%) had right coronary dissections that were repaired by Bentall's method with or without right coronary bypass grafting (CABG). Three (8.5%) of 35 patients with thoracic aneurysms had coronary disease. Among them, two had one vessel disease (1VD) and one had 2VD; two underwent temporary axillofemoral bypass grafting (AFBG) without CABG and one underwent extracorporeal circulation with CABG. Eight (5.6%) of 142 patients with abdominal aneurysms had coronary disease. They consisted of three patients with 1VD, two with 2VD and three with 3VD; their ejection fraction rates were 0.46 to 0.75. Three of them underwent temporary AFBG and one first underwent CABG but later underwent abdominal aortic graft replacement. In conclusion, patients with good coronary distal run-off and a low ejection fraction rate (under 0.5) should initially undergo CABG, but for those with poor run-off, temporary AFBG is better to prevent cardiac afterload.

Aged↗
PubMed1989

[A case report of aortitis syndrome with massive aortic regurgitation (AR), and ostial stenosis of the right coronary artery].

A 55-year-old female with massive aortic regurgitation and ostial stenosis of the right coronary artery due to aortitis syndrome was reported. The patient was admitted to the hospital with anterior chest pain and dyspnea on exertion. Retrograde aortogram showed massive aortic regurgitation and selective coronary angiogram revealed ostial stenosis of the right coronary artery. She was treated with aorto-coronary bypass (A-C bypass) and aortic valve replacement (AVR) with St. Jude Medical prosthetic valve. At operation, ostial stenosis of the right coronary artery due to aortitis syndrome was confirmed. Aortic valve replacement with a prosthetic valve and saphenous vein grafting to the distal right coronary artery were performed. Steroid therapy was started immediately after the operation. She recovered well and no complications was recognized after the operation.

Aortic Arch Syndromes↗
PubMed1989

Changes in lymphocyte subsets, mitogen responsiveness, and interleukin-2 production after cardiac operations.

We studied 104 patients after cardiac operations to search for changes in peripheral blood lymphocyte subsets, mitogen responsiveness, and interleukin-2 production. Mononuclear cells obtained from 10 patients with cholecystectomy were examined as control samples. Cultures for phytohemagglutinin and interleukin-2 production were incubated in microtiter plates for 24 hours with cells labeled with tritium thymidine used as target cells. Lymphocyte subsets were measured by using monoclonal antibodies. The results obtained with preoperative blood samples were compared with those from the first, third, and seventh days after operation. In patients having cardiac operations, mitogen responsiveness was low on both the first and the seventh days after operation and interleukin-2 production was markedly depressed (greater than 90% depressed) on the first postoperative day. However, in control samples from patients having cholecystectomy, lymphocyte subsets, mitogen responsiveness, and interleukin-2 production showed no significant changes. Improvement in interleukin-2 production occurred immediately in patients without blood transfusion from random donors and reached normal levels by postoperative day 3. However, interleukin-2 production remained depressed on day 3 in all patients with transfusion from random donors and remained significantly diminished even on day 7 in such patients in New York Heart Association classes III and IV. We conclude that heart operations for which cardiopulmonary bypass is used are associated with depression of cellular immunity, including interleukin-2 production. Furthermore, it appears that both blood transfusion from random donors and the general preoperative condition of the patients contribute to suppression of measures of cell-mediated immunity.

Adult↗
PubMed1989

[Studies of pathogenicity of GVHD induced by blood transfusion after open heart surgery].

We compared the case like acute GVHD (graft versus host disease) induced by blood transfusion with the cases after open heart surgery which received blood transfusion by the measurement of cell-mediated immunity. Furthermore, we investigated the etiology of GVHD in comparison with cases according to age. Seventy-three cases (under 60 years old: 55 cases, over 60 years old: 18 cases) underwent open heart surgery and the mean blood transfusion volume was 2368cc and the mean age was 52.8 years old. After open heart surgery the rate of peripheral OKT3+ and OKT4+ cells, lymphocyte transformation and IL-2 (interleukin 2 product) were significantly decreased at postoperative day (POD) 1 and recovered to preoperative value until POD 14. However, in the cases like GVHD the rate of OKT4+ cell was decreased in contrast with the change of OKT8+ cell, and lymphocyte transformation and IL-2 production did not recover to normal range postoperatively. In conclusion, in the cases like GVHD the postoperative charge of cell-immunity is similar to the acute GVHD induced after bone marrow transplantation and we must take care about the blood transfusion to the older patients after open heart surgery because there is a possibility that cell-mediated immunity may be more depressed in the elder patient pre and postoperatively.

Acute Disease↗
PubMed1989

[Case reports of fistula formation between aortic pseudo-aneurysms and atria after Bentall's operation].

Fistula between aortic pseudo-aneurysm and atrium occurred in two patients ten or thirteen years after initial Bentall's operation. Their chief complaints were edema of lower extremity, oliguria and dyspnea. Because the pseudo-aneurysm and fistula was suspected by continuous murmur and echocardiogram, cardiac catheterization and aortography were performed to make accurate diagnosis. In these cases, both the fistula and the leakage at the site of initial anastomosis were repaired as soon as the diagnosis was made. To our knowledge, there have been no such reports of aortic pseudo-aneurysm penetrating into the atrium after Bentall's operation.

Adult↗
PubMed1988

The surgical treatment of aortic regurgitation secondary to aortitis.

We describe the operative and perioperative management of 11 patients with aortic regurgitation due to aortitis. All patients required aortic valve replacement because of severely uncoapted cusps secondary to dilatation of the ascending aorta. The right coronary ostium was narrowed in 5 patients and consequently necessitated a smaller coronary tip for the administration of cardioplegic solution. To implant the prosthetic valve, pledgeted 2-0 Tevdek sutures were placed through the aortic valve annulus either from the ventricular side or from outside the aortic wall. Steroids were administered to 4 patients preoperatively and 8 patients postoperatively. Postoperative dehiscence of the prosthesis was seen in 1 of the 3 patients not given any steriods. We conclude that it is important to arrest the inflammatory reaction before operation and if the aortic valve must be replaced, to reinforce the implanted prosthesis with pledgeted sutures. Also, we suggest the possible importance of steroid therapy.

Adult↗
PubMed1987

Ventricular septal defect associated with aortic regurgitation.

The effectiveness of aortic valvuloplasty and the indications for aortic valve replacement were examined in 76 patients with ventricular septal defect associated with aortic regurgitation. Results of this study indicate aortic regurgitation is associated with rapid deterioration and that aortic valvuloplasty should be performed as soon as aortic regurgitation is detected. The data also suggest that aortoplasty is indicated if aortic valvuloplasty alone is inadequate for coaptation of the aortic cusps with thickening.

Adolescent↗
PubMed1987

Two Japanese families: a cultural perspective.

Some of the difficulties in treating second and third generation Japanese immigrant families are reviewed. An authoritarian, rather concrete approach to symptom relief is expected by, and is effective in, some families. The emphasis placed on academic achievement may lead to particular problems and misunderstandings. Two case examples of very different families are presented to emphasize a flexible therapeutic approach. Particular details of Japanese internment and population movements make the attitudes and behaviors of some families more comprehensible.

Acculturation↗
PubMed1987

Nonspecific esterase activity expressed in Weibel-Palade bodies of cloned guinea pig aortic endothelial cells.

We studied the localization of nonspecific esterase activities in cloned guinea pig aortic endothelial cells using ultrastructural cytochemistry. Weibel-Palade bodies (WPB), which are known to contain von Willebrand protein, were positive for esterase, defining a heretofore unrecognized activity of these organelles. Esterase activity was also found localized to the external surface of the plasma membrane, to cytoplasmic lipid bodies, and to the outer (cytoplasm-facing) surface of certain membrane-bound cytoplasmic vacuoles. Localization of esterase activity to these four discrete sites probably reflects the presence of a number of endothelial cell enzymes capable of hydrolyzing alpha-naphthyl acetate or butyrate. The physiological substrate and biological function of these enzyme activities are not presently understood.

Animals↗