Search PubMed⌕ Search

Biomedical subjects

S Miki

Publications and source records attributed to S Miki.

At least 73 records · Page 4Linked to original sources
PubMed1996

Mixed neuronal-glial tumors (gangliogliomas) in children.

Mixed tumors account for about 10% of the childhood central nervous system tumors. Studies of the most common tumor, the ganglioglioma, in patients of all ages suggest that optimal therapy is total gross resection. There are few studies on these tumors in children. In our institution between 1984 and 1993, 28 children with gangliogliomas (4 of which were anaplastic) and 4 children with dysembryoplastic neuroepithelial tumors were treated and followed. Fourteen had local subarachnoid involvement. Total gross resection was usually curative, regardless of histology. Subarachnoid involvement was not indicative of a poorer prognosis.

Adolescent↗
PubMed1996

Synthesis and biological activity of novel 1,3-benzoxazine derivatives as K+ channel openers.

A new series of 1,3-benzoxazine derivatives with a 2-pyridine 1-oxide group at C4 was designed to explore novel K+ channel openers. Synthesis was carried out by using a palladium(0)-catalyzed carbon-carbon bond formation reaction of imino-triflates with organozinc reagents and via a new one-pot 1,3-benzoxazine skeleton formation reaction of benzoylpyridines. The compounds were tested for vasorelaxant activity in tetraethylammonium chloride (TEA) and BaCl2-induced and high KCl-induced contraction of rat aorta to identify potential K+ channel openers, and also for oral hypotensive effects in spontaneously hypertensive rats. An electron-withdrawing group with the proper shape at C6 and a methyl or halogeno group at C7 of the 1,3-benzoxazine nucleus were required for the development of optimal vasorelaxant and hypotensive activity. In particular, 2-(6-bromo-7-chloro-2,2-dimethyl-2H-1,3-benzoxazin-4-yl)pyridine 1-oxide (71) showed more potent vasorelaxant activity (EC50 = 0.14 microM) against TEA and BaCl2-induced contraction and longer-lasting hypotensive effects than cromakalim (1).

Animals↗
PubMed1996

Effect of low dietary calcium intake on blood pressure and pressure natriuresis response in rats: a possible role of the renin-angiotensin system.

Dietary Ca is an important modulator of blood pressure in humans and rats. Since the kidney plays a key role in the pathogenesis of hypertension, the effects of a low Ca diet (0.01% Ca) on blood pressure and pressure natriuresis response were studied in normotensive Sprague-Dawley rats. In addition, a possible role of the renin-angiotensin system in the development of hypertension and an altered pressure natriuresis response resulting from low dietary Ca intake was examined. In the low Ca diet group, systolic blood pressure measured by the tail-cuff method was significantly higher than in the normal Ca diet group (1,1% Ca) 1 week after the diet (1 13.0 +/- 7.1 vs. 105.0 +/- 9.5mmHg, p < 0.05). After 4 weeks, the hypertension was more pronounced. Low dietary Ca intake significantly inhibited the water and sodium excretory responses to acute elevation of renal perfusion pressure by tightening an infrarenal aortic constriction. Treatment with an inhibitor of angiotensin-converting enzyme, captopril (30 mg/kg/day), completely abolished the elevation of blood pressure and attenuated the reduced pressure natriuresis response observed in Ca-deficient rats. Although plasma renin activity was not different between the low and normal Ca diet groups after the 2-week dietary regimen, the pressor response to angiotensin II was enhanced by 30% in the low Ca diet group and there was a significant difference in the pressor response between the two groups. These results suggest a possible involvement of the renin-angiotensin system in the development of hypertension and an inhibitory effect on the pressure natriuresis response caused by low dietary Ca intake, via an enhanced sensitivity to angiotensin II.

Analysis of Variance↗
PubMed1996

[Surgical treatment of double-orifice mitral valve associated with incomplete-type endocardial cushion defect].

We report surgical treatment of double-orifice mitral valve (DOMV) associated with incomplete-type endocardial cushion defect. All three cases had "central type DOMV classified by Cascos" with bridging tissue between two mitral orifices. We closed mitral cleft in the two cases with moderate mitral regurgitation, although we left the bridging tissue. It is thought to be beneficial to leave the bridging tissue undivided to avoid postoperative mitral regurgitation in such cases.

Adult↗
PubMed1996

[Surgical treatment of infective endocarditis].

From 1981 to 1996, 48 consecutive patients, aged range 1 to 72 years, underwent surgical treatment for infective endocarditis. The infection was in the aortic valve in 10 patients, the mitral valve in 17, the aortic and mitral valves in 7, mixed aortic, mitral and tricuspid valves in one, the tricuspid valve in 9, the pulmonary valve in 3, and the other in 2, thirty-seven patients had native valve endocarditis (NVE) of which 22 cases were in the active stage. Seven cases had active prosthetic valve endocarditis (PVE) and 4 had VSD patch infection. The overall hospital mortality rate was 14.6% (7/48). The hospital mortality rate of NVE was 2.7% (1/37) and that of active NVE was 4.5% (1/22). That of PVE was 71.4% (5/7) and one of 4 cases with VSD patch infection was lost, so the mortality rate of the prosthetic material infection was 54.5% (6/11). Only 1 patient required reoperation for persistent infection. There were 2 late deaths caused by noncardiac disease. Thirty-nine of the total IE patients are now survived. These data demonstrate excellent results in patient with NVE undergoing the surgical treatment at the early phase, and support the premise that patients with active PVE should have also early surgical intervention.

Adolescent↗
PubMed1996

[A post-thymomectomy case of myasthenia gravis which developed nephrotic syndrome with membranous nephropathy during azathioprine administration].

We report a 46-year-old woman who has been suffered from myasthenia gravis and underwent thymomectomy in December 1988. Her myasthenic symptoms improved by treatment with corticosteroid and azathioprine; the latter drug was administrated for more than one year. She noticed weight gain of 10 kg and edema in both legs and feet, which developed acutely in August 1994. Laboratory data showed that she suffered from nephrotic syndrome with a large amount of proteinuria (15 g/day). Renal biopsy revealed that biopsied glomeruli showed early stage of membranous nephropathy associated with acute tubular necrosis. Although therapeutic trials of steroid pulses could not eliminate proteinuria, substitution of cyclophosphamide for azathioprine brought marked improvement of the nephrotic syndrome with disappearance of the urinary protein excretion within 10 days. From reports of similar cases with myasthenia gravis in Japan and in Europe, therapeutic usage of azathioprine in patients with myasthenia gravis associated with thymoma should be cautious for appearance of nephrotic syndrome when azathioprine is continued for more than one year.

Azathioprine↗
PubMed1995

Mitral valve replacement with a collar-reinforced prosthetic valve for disrupted mitral annulus.

The mitral valve was replaced with a collar-reinforced prosthetic valve in 6 patients with a disrupted mitral annulus, in 3 because of infective endocarditis, including 2 patients with prosthetic valve endocarditis, in 2 because of a severely calcified mitral annulus, and in 1 who had previously undergone mitral valve replacement twice. Four patients had undergone prior mitral operations; these consisted of mitral valve replacement in 3 patients and mitral valve repair in 1. In all patients, the prosthesis was secured by double-layered sutures, with the first row of buttressed sutures passing through the leaflet or sutured to the left ventricular muscle and through the sewing cuff of the prosthetic valve. The second row of running sutures was then placed through an extended annular equine pericardial cuff of the prosthetic valve and the supraannular left atrial wall. In 2 patients, all chordae tendineae were preserved to maintain annulopapillary muscle continuity. All patients survived and have remained well for a mean of 22.3 months. There has been no prosthetic valve dehiscence, except for minimal paraprosthetic leakage in 1 patient. These results demonstrate that mitral valve replacement in patients with a disrupted mitral annulus can be successfully accomplished with a collar-reinforced prosthetic valve.

Aged↗
PubMed1995

A simple and rapid method for preliminary evaluation of in vivo efficacy of anti-HIV compounds in mice.

In vivo efficacy of anti-HIV compounds is affected by various factors such as bioavailability, metabolism, clearance, and toxicity. Here we report a simple and rapid method that might be useful for preliminary evaluation of in vivo efficacy of anti-HIV compounds. MT-4 cells carrying proviral HTLV-1 were infected with HIV-1 in vitro and injected into the peritoneal cavity of SCID mice or BALB/c mice. Inoculated cells survive for 1-2 days, and support one to two cycles of viral replication which can be monitored by RT activity or p24 content in the supernatants of peritoneal wash fluids. Test compounds were administered either orally or subcutaneously. AZT, DDC and DDI, the nucleoside-type RT inhibitors currently in clinical use, all showed potent anti-HIV-1 activities in this mouse/MT-4 assay. HEPT (E-EBUdM), a non-nucleoside RT inhibitor, also showed potent anti-HIV-1 activity in vivo, whereas TIBO (R82913), another non-nucleoside RT inhibitor, was less active. In protease inhibitors KNI-272 and Ro 31-8959 showed good in vivo activities, while KNI-144, a compound closely related to KNI-272, showed poor in vivo activity. This mouse/MT-4 assay, although having a number of shortcomings as an animal model for HIV-1 infection, may be of some practical utility for preliminary evaluation of in vivo efficacy of potential anti-HIV compounds.

Animals↗
PubMed1995

Early and late results of repair of tetralogy of Fallot with subarterial ventricular septal defect. A comparative evaluation of tetralogy with perimembranous ventricular septal defect.

Between November 1966 and December 1990, 511 pediatric patients with tetralogy of Fallot underwent corrective operation at Tenri Hospital. There were 78 patients with subarterial ventricular septal defect. Mean age at repair was 5.6 +/- 3.3 years. The method of right ventricular outflow tract reconstruction was simple infundibulectomy in 14 patients, right ventricular ventricular outflow patch in 36, and transannular patch in 28. There were 7 (9.0%) early deaths as a result of low cardiac output syndrome and acute renal failure. The pressure ratio of the right ventricle to the left ventricle was 0.62 +/- 0.18 during the early postoperative catheterization. Follow-up was achieved for 442.6 patient-years and ranged from 0.5 to 27 years, with an average of 8.5 +/- 6.7 years. There were three late deaths (2 cardiac and 1 noncardiac). Actuarial survival was 94.8% +/- 4.0% at 20 years. Catheterization during late follow-up (6.8 +/- 4.7 years after repair) was done in 53 patients and the pressure ratio of the right ventricle to the left ventricle was 0.48 +/- 0.21. Fifteen patients underwent subsequent operation because of residual lesions, including ventricular septal defect in four patients, pulmonary stenosis in nine, combined ventricular septal defect and pulmonary stenosis in one, and pulmonary regurgitation in one, with no mortality. Actuarial rate of freedom from reoperation was 71.1% +/- 8.0% at 10 years and 58.8% +/- 16.8% at 20 years. Patients with tetralogy and subarterial ventricular septal defect were more likely to have the development of residual obstruction at the level of the pulmonary valve anulus after repair than were those with tetralogy and perimembranous ventricular septal defect.

Abnormalities, Multiple↗
PubMed1995

Continuous retrograde cerebral perfusion aids repair of aortic laceration during sternal re-entry.

We successfully repaired an anticipated large laceration of the ascending aorta occurring during sternal re-entry in a 68-year old woman undergoing replacement of a prosthetic aortic valve. Cerebral protection was ensured by using continuous retrograde cerebral perfusion via femoro-femoral bypass with deep hypothermia. The cooling time was 20 minutes. The minimum nasopharyngeal temperature was 15 degrees C and the duration of the retrograde perfusion was 11 minutes at a rate of 600 ml per minute. The postoperative course was uneventful and no neurological deficits occurred.

Aged↗
PubMed1995

Diagnostic relevance of abortion-associated human embryonic antigen expressed on the cell surface of tumour promoter-treated Bloom syndrome cells.

We detected stable expression of human embryonic antigen associated with spontaneous abortion (HEAA) on the cell surface of a tumour promoter-treated B lymphoblastoid cell line (BS-SHY) originating from Bloom syndrome. We used indirect immunofluorescence and diluted serum from 44 patients who had recurrent spontaneous abortions. With the use of the panning procedure, we separated characteristic cells expressing strong HEAA. The BS-SHY-HEAA cells separated here would be useful for measuring serum antibody (against HEAA) produced by patients with recurrent abortions. It was also noted that aborters who received husbands' leukocyte immunization have lost this antibody, and have delivered successful pregnancies at term. Using HEAA proteins, we conducted Western blotting analysis for the amino acid sequencing (mol. wt 77 kDa). Amino acid sequencing data indicated that HEAA had 87.5% homology to the immunoglobulin (Ig) VHIII region in the framework. Recently, the protective value of high dose i.v. administration of immunoglobulin in the treatment of recurrent spontaneous abortions has been reported to be similar to that of leukocyte immunization. Therefore, the BS-SHY-HEAA cells appear to provide a valuable tool for rapid serological diagnosis and for evaluating the efficacy of immunotherapy with husbands' leukocytes in patients with recurrent spontaneous abortions.

Abortion, Habitual↗
PubMed1995

[Report of a severely deformed and calcified equine pericardial patch using for intracardiac repair of tetralogy of Fallot].

An 11-year-old boy with tetralogy of Fallot had undergone palliative right ventricular outflow tract reconstruction twice previously. After the second palliative surgery recurrent mediastinitis persisted. At the age of 5 years and 11 months, he underwent closure of VSD and reconstruction of the right ventricular outflow tract with an equine pericardial patch after removal of the infected prosthetic material. The postoperative course was uneventful, however, severe pulmonary stenosis developed 6 years later. The stenosis was caused by the severely deformed and calcified equine pericardial patch used for intracardiac repair. The reason for severe calcification seemed to be the accentuated calcium metabolism in children, hemodynamic stress and persistent infection.

Bioprosthesis↗
PubMed1995

[A rare case of coronary artery perforation by a PTCA guide wire complicating with postinfarction cardiac rupture after thrombolytic therapy].

We report a rare case of coronary artery perforation by a guide wire for percutaneous transluminal coronary angioplasty (PTCA) complicating with postinfarction cardiac rupture (oozing type). The patient had acute myocardial infarction on the extensive anterior wall and developed cardiac rupture followed by serious cardiac tamponade during the emergency PTCA several hours after tissue plasminogen activator (t-PA) given intravenously. The meandering left anterior descending artery (LAD) was found injured by a PTCA guide wire apart from a small oozing-type cardiac rupture near the apex. We repaired urgently the perforated LAD as well as the ruptured left ventricle. It is thus suggested that coronary artery perforation by a PTCA guide wire may occur on meandering coronary arteries and develop a serious hemorrhagic complication, particularly after thrombolytic therapy.

Angioplasty, Balloon, Coronary↗
PubMed1995

[The prevalence of atherosclerotic lesions in the aortic arch].

In relation to the aortic arch operation, atherosclerotic lesions in this area was investigated in autopsy specimen. Fifty specimens of the aorta with severe atherosclerotic lesions were chosen from 182 autopsies of patients older than 70 years at Tenri Hospital. The aortic arch and the adjacent aorta were divided into 9 segments (three portions around orifices of the arch tributaries [1-3], the ascending aorta proximal to the branchiocephalic artery [4], the descending aorta distal to the left subclavian artery [5], and 4 portions of the aortic arch which consisted with proximal anterior [6], distal anterior [7], proximal posterior [8], and distal posterior wall [9]) as shown in the figure. The degree of atherosclerosis was scored by Gore-Tejada atherosclerosis index (ASCI). The ASCI of the arch (12.7) was significantly higher than the ascending aorta (5.3). (p > 0.05). Among 9 segments of the aortic arch, the ASCIs of the anterior wall of the distal arch (25.1), the aorta distal to the left subclavian artery (17.3), the arch around the orifice of the brachiocephalic artery (17.1) were significantly higher. The ulcerative plaques were predominantly found at the anterior wall of the distal arch (36%). On the other hand, the calcified plaques were predominantly found around the orifice of the brachiocephalic artery (26%). Ten specimens demonstrated significant stenosis at the orifice of the left subclavian artery. From this autopsy study, the degree of atherosclerotic lesion was predominant at the anterior wall of the distal aortic arch and at around the orifice of the brachiocephalic artery.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1995

[Long-term results of mitral valvuloplasty for mitral regurgitation].

From July 1979 to February 1995, 126 patients, including 4 reoperations, aged between 6 months and 77 years underwent mitral valve repair for mitral regurgitation. The patients were divided in two groups, 46 patients aged less than 16 years in pediatric age group and the other 80 patients in a dult group. The methods consisted of asymmetric annuloplasty (Kay-Reed method) in 98 patient, Carpentier-Edwards ring annuloplasty in 14, quadrangular resection of the posterior leaflet with annuloplasty in 9, and chordal and leaflet repair in 5. There was no hospital nor late death in pediatric age group. Three hospital deaths and one late death were in adult group. Follow-up was 96% complete and totaled 812.1 patient years. Reoperations underwent in 3 pediatric patients and 9 adults. At 15 years' follow-up, freedom from reoperation was 91.5 +/- 4.7% in pediatric age group and 67.1 +/- 12.7% in adults. Freedom from event was 63.5 +/- 12.1% in adult group. These results suggest that mitral repair with Kay-Reed method in pediatric age group is favorable for long-term. In contrast, indications for mitral reconstraction with other methods including ring annuloplasty should be extended for aged patients with severely dilated annuls and degenerated leaflets.

Adolescent↗
PubMed1995

[Successful surgical treatment for ruptured distal aortic arch aneurysm into lung].

We report successful aortic arch replacement using continuous retrograde cerebral perfusion (CRCP) for the three cases of ruptured distal aortic arch aneurysm (DAAA) into the left lung. All of them, who had preoperative episodes of hemosputum and hemoptysis, were diagnosed rupture of DAAA into the lung with computed tomography, magnetic resonance image, aortography or transesophageal echo. Following urgent graft replacement of the aortic arch or repair of the rupture on the suture line in the previous arch vessel reconstruction was carried out safely through median sternotomy approach. The left upper lobe of lung adherent tightly to the DAAA wall was not dissected to prevent the lung from bleeding, air leakage and infection. All of them, who awoke smoothly after CRCP, did not developed any pulmonary complications and survived uneventually. We concluded that median approach and not tearing lung from DAAA wall might be key-points for successful operation in cases of ruptured DAAA into lung and that CRCP is an safe and useful method to protect brain in such cases.

Aged↗