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Biomedical subjects

K Kuwaki

Publications and source records attributed to K Kuwaki.

32 records · Page 2Linked to original sources

Lazaroid U74389G ameliorates ischemia-reperfusion injury in the rat lung transplant model.

We investigated the effect of Lazaroid U74389G on ischemia-reperfusion injury in the rat orthotopic left lung transplantation model. Five groups of reperfused lungs were studied. In group I, donor lungs were transplanted after 12 hours of preservation in University of Wisconsin (UW) solution at 4C. In groups II, III, and IV, Lazaroid was intravenously administrated at a dose of 1 mg/kg, 8 mg/kg, and 15 mg/kg, respectively, to the donors 30 minutes before preservation and also to the recipients 30 minutes before reperfusion after 12 hours of storage in UW solution at 4C. In group V, Lazaroid was added to the UW solution (80 micromol/l), and also was administered intravenously (6 mg/kg) 30 minutes before reperfusion. After 1 hour of reperfusion, gas exchange function and tissue lipid peroxide levels were significantly improved in Lazaroid-treated groups III, and V compared with no treatment group I. Histologic damage was less severe in groups III, IV, and V than in group I. These findings suggest that Lazaroid U74389G ameliorates ischemia-reperfusion injury in the rat lung transplants by inhibiting lipid peroxidation, regardless of whether it is administrated intravenously or given as an additive to the preservation solution.

Analysis of Variance↗

[Focal segmental glomerulosclerosis associated with type C virus hepatitis and decrement of proteinuria by interferon-alpha therapy].

Focal segmental glomerulosclerosis (FSGS) associated with type C virus (HCV) hepatitis has not been described in the literature to date. However, we experienced a 30-year-old man, who had had HCV hepatitis, developed nephrotic syndrome and was admitted to our hospital. The first renal biopsy showed FSGS which was diagnosed by light, immunofluorescent, and electron microscopic study. FSGS diagnosis was based upon the findings of focal segmental glomerular sclerosis associated with hyalinosis and foam cells, segmental deposition of IgM and C3 on glomeruli, and epithelial cell vacuolization in the Bowman's space. HCV hepatitis was treated with interferon-alpha (INF-alpha) over 6 months. The treatment brought the disappearance of not only HCV-RNA from the blood, but also the manifestation of nephrotic syndrome. Therefore, the second renal biopsy was performed, but did not reveal any great pathological improvement. Five months later after the remission, he again had an elevated HCV-RNA level and a relapse of nephrotic syndrome. He was retreated with the same therapy and achieved a second remission of nephrotic syndrome. FSGS associated with HCV hepatitis is described first and the implication of INF-therapy in the improvement of proteinuria is discussed.

Adult↗

Long-term results of porcine bioprostheses in the tricuspid position.

From January 1976 to September 1994, 26 patients underwent a tricuspid valve replacement (TVR) with porcine bioprostheses (Hancock II in 19 patients, Carpentier-Edwards in 3, Hancock standard in 2, Medtronic-Intact in 1, and Liotta in 1). The mean age of these patients was 38.4 years (range, 9 to 70 years). The mean follow-up period was 6.7 years (range, 1.8 to 16.5 years). There was a complete follow-up in 100%. There were two hospital deaths and three late deaths. The actuarial survival rate at 16 years was 78.7%+/-8.6%. Five patients developed structural deterioration. Four of these 5 patients underwent re-TVR. The actuarial freedom rate from structural deterioration at 10 years was 47.1%+/-19.1%. There were no instances of thromboembolism and prosthetic valve endocarditis. Our experience indicated the major problem of the porcine bioprostheses in the tricuspid position thus to be valve durability: however, the long-term actuarial survival rate was satisfactory, including no operative morality with re-TVR due to tricuspid prosthetic structural deterioration. We therefore conclude that the choice of a porcine bioprosthesis in the tricuspid position should be considered not only for patients with isolated tricuspid valve disease, but also for the patients who have not previously received mechanical valves in the mitral or the aortic valve position.

Adolescent↗

[Redo operation for recurrent pulmonary artery aneurysm associated with pulmonary stenosis and regurgitation].

A 63-year-old woman who underwent surgical correction of a recurrent pulmonary artery aneurysm associated with pulmonary stenosis and regurgitation is reported. On April 1986, she underwent commissurotomy of pulmonary valve, reconstruction of right ventricle out flow tract using a Polystan monocusp patch and pulmonary aneurysmorrhaphy for pulmonary artery aneurysm. Pathological examination of the resected pulmonary arterial wall revealed mucoid degeneration of media and fragmentation of elastic fiber. Nine years after the operation, recurrence of pulmonary artery aneurysm, pulmonary stenosis and regurgitation were recognized. On September 1995, she underwent redo operation with graft replacement of pulmonary artery and pulmonary valve replacement using woven Dacron prosthesis containing a Carpentier-Edwards bioprosthetic valve. We should choose as an initial procedure with graft replacement for pulmonary artery aneurysm with fragility of the pulmonary arterial wall. She is now doing very well at one year and 5 months after the redo operation.

Aneurysm↗

Ten years' experience of aortic valve replacement with the Omnicarbon valve prosthesis.

BACKGROUND: There are few clinical studies on late follow-up of the Omnicarbon monoleaflet valve. We report our 10-year experience with this valve in the aortic position and also compare late hemodynamic performance of this valve with that of the CarboMedics valve in the aortic position. METHODS: From January 1985 to June 1995, 117 consecutive patients underwent aortic valve replacement (AVR) with the Omnicarbon valve. There were 66 men and 51 women aged 13 to 69 years (mean age, 50 +/- 12 years). They were divided into three groups: group 1 (43 patients) had isolated AVR, group 2 (36) had AVR and concomitant operations, and group 3 (38) had combined AVR and mitral valve replacement. Follow-up was 96.6% complete and consisted of 882.7 patient-years (range, 2.5 to 10.6 years; mean follow-up, 7.5 +/- 2.7 years). RESULTS: There were three early deaths (2.6%) and 18 late deaths (2.0%/patient-year) ten of which were due to valve-related causes and eight, non-valve-related causes. Survival rates at 10 years in groups 1, 2, and 3 were 77.6%, 82.4%, and 78.6%, respectively. The overall rates of freedom from valve-related complications in groups 1, 2, and 3 at 10 years were 77.4%, 100%, and 80.9%, respectively. The rates of freedom from the following complications in groups 1, 2, and 3 at 10 years were as follows: thromboembolism--94.8%, 100%, and 89.4%, respectively; valvar thrombosis--95.0%, 100%, and 100%; anticoagulant-related hemorrhage--93.6%, 100%, and 93.4%; prosthetic valve endocarditis--93.0%, 100%, and 97.2%; and reoperation--90.6%, 100%, and 97.2%. There were no significant differences between groups. All survivors showed marked improvement in New York Heart Association functional class, from 86% in classes III and IV preoperatively to 96% in classes I and II postoperatively. The Omnicarbon valve exhibited no significant difference in hemodynamic performance after isolated AVR compared with the CarboMedics bileaflet valve at the same follow-up periods. CONCLUSIONS: This 10-year study confirms that the Omnicarbon valve is a durable prosthesis and provides excellent functional improvement with low rates of thromboembolism and valvar thrombosis in the aortic position.

Adolescent↗

[Early and late results of surgical intervention for 32 active infective endocarditis patients in last 10 years].

Thirty-two active infectious endocarditis patients who underwent 36 surgical procedures (23 NVEs, 13 PVEs) in last 10 years were reviewed. Seven patients (19.4%) died early postoperatively, 3/23 (13%) in NVEs and 4/13 (31%) in PVEs, and the causes of death were LOS in 5, MOF in one and cerebral bleeding in one. NVE patients of double valve deterioration who developed cardiogenic shock had poor operative results, 3 death in 4 (75%) despite of circulatory assist. Aortic PVEs who underwent Danielson's translocation technique also showed 3 death in 4 (75%). Five in 25 survivors (20%) developed late death and 3 of them were related with reinfection of prosthetic valve. We concluded that surgical treatment for active IE provides reasonable results, although they are still challenging for double valve NVEs and aortic PVEs, for which aortic root replacement using homograft would be the procedure of choice.

Adolescent↗

[Two cases of surgically treated malignant primary tumors originated from the pulmonary artery].

Two surgically treated cases of malignant tumors which originated inside of the pulmonary artery were reported. A 62-year-old female with an undifferentiated sarcoma and a 24-year-old male with a malignant fibrous histiocytoma were successively operated on in two months for the release of their chief complaints of exertional dyspnea. In the first case the tumor was resected completely, although partially resected in the second case. Preoperatively, noninvasive examinations including the echocardiography, the computed tomography and the magnetic resonance imaging confirmed the presence of these tumors in the main pulmonary arteries in both cases and also the invasion to the vessel wall with the growth to the pericardial cavity in the second case. Both patients are doing well and has been followed up at the out-patient department 22 and 20 months after surgery, respectively.

Adult↗

[Clinical experience in 3 cases, 5 events of thrombosed Björk-Shiley mitral prostheses].

We have successfully treated 3 cases, 5 events of thrombosed Björk-Shiley mitral prostheses. Case 1: Treatment with urokinase thrombolytic therapy failed to improve the valve opening, and then submergent surgical thrombectomy was performed successfully. Case 2: This case was recurrent thrombosed valve. First time thrombosis was successfully managed by urokinase thrombolytic therapy. Second time thrombosis was treated with emergent surgical thrombectomy. Third time thrombosis was treated with urokinase thrombolysis and elective replacement of the Björk-Shiley valve with a 25 mm SJM valve. Case 3: Urokinase thrombolytic therapy failed to improve the valve function, and then emergent replacement of the Björk-Shiley valve with a 25 mm SJM valve was performed successfully. These cases suggested that the surgical treatment for the thrombosed Björk-Shiley mitral valve should be performed without delay in the patient whose condition is rapidly deteriorating.

Adult↗

Resetting of tachycardia cycle by single and double ventricular extrastimuli in recurrent sustained ventricular tachycardia.

In two cases with recurrent sustained ventricular tachycardia (VT) due to re-entry, the response pattern to extrastimuli during the tachycardia was studied. In each case, right ventricular extrastimuli with longer coupling intervals during VT were followed by fully compensatory pauses and with shorter coupling intervals reset the tachycardia cycle. In one case, a plateau was produced by a single extrastimulus, resembling that seen in the response curve of sinus node automaticity as well as ectopic atrial tachycardia. Two successive stimuli produced three definite zones, i.e., fully compensatory, reset producing a plateau, and progressive prolongation zones with shortening of the coupling intervals between the two stimuli, and terminated the tachycardia with further shortening of the coupling intervals. In conclusion, resetting phenomenon was confirmed on two cases with re-entrant VT. This phenomenon cannot be used as a criterion to determine the mechanism responsible for VT.

Adult↗

Potential of aspirin to inhibit thrombotic microangiopathy in alpha1,3-galactosyltransferase gene-knockout pig hearts after transplantation in baboons.

Hearts from alpha1,3-Galactosyltransferase gene-knockout (GaIT-KO) pigs were transplanted heterotopically into 8 baboons that received an anti-CD154 monoclonal antibody (mAb)-based immunosuppressive regimen and heparin. Three baboons died or were euthanized with beating grafts on 16, 23, and 56 days, respectively, and the remaining 5 grafts functioned for 59-179 days. Hyperacute rejection did not occur, and classical features of acute humoral xenograft or acute cellular rejection were rare. However, thrombotic microangiopathy (TM) developed in all cases; its onset was delayed in 2 baboons that received aspirin. Function of a pig organ in a baboon for a period approaching 6 months has not been reported previously and lends encouragement that the barriers to xenotransplantation will be overcome, but TM requires investigation.

Animals↗