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Biomedical subjects

F Okamoto

Publications and source records attributed to F Okamoto.

At least 37 records · Page 2Linked to original sources
PubMed1999

[Prosthetic valve replacement in children].

Between 1975 and 1998, 27 patients aged 3 months to 14 years underwent replacement of the aortic, mitral, tricuspid, and pulmonary valves. Five different types of prosthetic valves were used; three were mechanical valves and two were bioprosthetic valves. There were 3 hospital deaths. Among the 24 survivors there were 4 late deaths. Arrhythmia requiring pacemaker implantation occurred in 2 cases after AVR and TVR. Thromboembolic events occurred in 3 patients, all with mechanical valves in pulmonary position. Infective endocarditis occurred in 1 patient after PVR with a mechanical valve. No bleeding complication occurred among the patients on a regimen of Coumadin and Dipyridamole. Two patients, both with Hancock bioprosthesis, required a second valve replacement on account of severely calcified changes. Mechanical valves in left side heart had a satisfactory long-term performance. One patient who had undergone MVR for congenital parachute mitral valve received reoperation for growth. A larger sized prosthetic valve should be used at the first replacement, and special procedures including supra-annular positioning or annular augmentation are recommended for MVR or AVR respectively.

Adolescent↗
PubMed1999

CD36 mediates long-chain fatty acid transport in human myocardium: complete myocardial accumulation defect of radiolabeled long-chain fatty acid analog in subjects with CD36 deficiency.

Long-chain fatty acids (LCFA) are the major energy substrate for heart and their oxidation is important for achieving maximal cardiac work. However, the mechanism of uptake of LCFA by myocardium has not been clarified. We previously reported that bovine myocardial LCFA transporter has a sequence homology to human CD36. Clinically, total defect of myocardial uptake of radiolabeled long-chain fatty acid analog [123I-BMIPP: Iodine-123 15-(p-iodophenyl)-(R,S)-methylpentadecanoic acid] has been reported in some restricted cases, but the etiology has not been clarified. In the present study, we analyzed CD36 expression and CD36 gene in subjects who showed total lack of myocardial 123I-BMIPP accumulation, and, vice versa, evaluated myocardial 123I-BMIPP uptake in subjects with CD36 deficiency. Four unrelated subjects were evaluated, Two were found to have negative myocardial LCFA accumulation by 123I-BMIPP scintigraphy, after which the expression of CD36 on their platelets and monocytes was analyzed. Remaining two subjects were identified as CD36 deficiency by screening, then 123I-BMIPP scintigraphy was performed. Expression of CD36 on platelets and monocytes was measured by flow cytometric analysis. The molecular defects responsible for CD36 deficiency was detected by allele-specific restriction enzyme analysis. CD36 expression was totally deficient in all 4 subjects on both platelets and monocytes. Two subjects were homozygous for a 478C-->T mutation. One was heterozygous for the dinucleotide deletion of exon V and single nucleotide insertion of exon X, and remaining one was considered to be heterozygous for the dinucleotide deletion of exon V and an unknown gene abnormality. All cases demonstrated a completely negative accumulation of myocardial LCFA despite of normal myocardial perfusion, which was evaluated by thallium scintigraphy. In addition, all cases demonstrated apparently normal hepatic LCFA accumulation Thus, these findings suggested that CD36 acts as a major myocardial specific LCFA transporter in humans.

Aged↗
PubMed1999

Long term follow-up of atrioventricular valve function after repair of atrioventricular septal defect.

To elucidate the factors which are associated with early and late operative results of atrioventricular septal defects, 102 consecutive patients who underwent reparative operation of atrioventricular septal defects (AVSD) in our institution since 1968 were studied. Our operative technique was basically the same through this period. That is the two patch method in its complete form (the so-called Shirotani's method) and preferential use of cleft closure supplemented with Kay-Reed-Wooler type annuloplasty. Early mortality (< 30 days) rate was 18.6%. More than 80% of the early deaths were not related to atrioventricular valve malfunction. Non-complete closure of the cleft, high preoperative pulmonary vascular resistance, deficient atrioventricular valve, and complete form showed independent correlations with early mortality in multiple logistic regression analysis. For operative survivors, event-free survival curves, for atrioventricular valve related reoperations were drawn for various factors. Two late deaths and 3 late atrioventricular-valve-related reoperations occurred. The event-free actuarial survival for operative survivors at 5, 10, and 20 years were 97.0%, 89.4%, and 89.4%, respectively. The survival analysis revealed that preoperative high pulmonary vascular resistance, preoperative severe atrioventricular regurgitation, and preoperative large cardiothoracic ratio in chest radiogram were related with late event occurrence. Higher early mortality in our series may be attributable to relatively advanced pulmonary vascular occlusive disease rather than post repair atrioventricular valve malfunction. On the other hand, our late results were rather good. We concluded that the Shirotani's method and preferential use of cleft closure supplemented with Kay-Reed-Wooler type annuloplasty was effective for most of atrioventricular valves in atrioventricular septal defects. Early surgical intervention before pulmonary vascular disease progression or atrioventricular valve regurgitation development is also important.

Cardiac Surgical Procedures↗
PubMed1999

[Assessment of internal thoracic artery grafts using duplex scanning].

In an effort to develop a noninvasive method to evaluate flow characteristics of the internal thoracic artery grafts (ITAG) after coronary artery bypass grafting, we performed duplex scanning of ITAGs of 51 patients who underwent bypass grafting. The ITAG was visualized with a duplex scanner of 7.5 MHz through the first or second left intercostal space. The visualization of the ITAG was adequate to make reliable measurements in 47 patients (92.2%). The diameter of the vessel, systolic peak velocity, and diastolic peak velocity were recorded, and systolic flow volume, diastolic flow volume, velocity ratio, flow volume ratio, and diastolic flow volume fraction were calculated. The velocity ratio, flow volume ratio, and diastolic flow volume fraction were markedly higher in the unstenotic subjects than in the stenotic subjects. In the group in which severe LAD stenosis were recognized preoperatively, both systolic and diastolic flow volumes were increased compared with moderately stenotic group. No differences in flow characteristics could be demonstrated between the subjects with old anterior myocardial infarction and without it. In 10 patients in whom flow pattern was abnormal or not identified, angiography revealed graft stenosis or predominant native coronary arterial flow. Duplex scanning is thought to be a reliable, sensitive, and noninvasive technique for the assessment of the ITAG.

Adult↗
PubMed1999

[Emergency coronary artery bypass grafting with integrated myocardial protection].

In the following retrospective study we reviewed the early postoperative results of emergency CABG; the myocardial management was achieved by utilization of integrated myocardial protection including warm cardioplegic induction, performed at our hospital. From April 1st 1994 to October 30th 1998; 63 patients underwent emergency CABG with integrated myocardial protection. All surgical procedures were performed within 6 hours from the onset of disease or admission transferred from another hospitals. Age ranged 48 to 86 years (mean 69.9 +/- 8.5; 41 male, 22 female). AMI was present in 52, UAP in 11. Preoperative PTCA was done in 20 and IABP was inserted in 53. Cardiogenic shock in 26, mechanical complications in 6, three vessel disease in 48 and LMT disease in 17 was present. Eight patients (12.7%) died in the early postoperative period. Among evaluated risk factors for early postoperative death; the occurrence of cardiogenic shock, mechanical complications of AMI, preoperatively done PTCA and prolonged CPB time were significantly increasing the mortality rate in early postoperative death.

Aged↗
PubMed1998

Double cardiac rupture after direct infarct coronary angioplasty: report of a case.

The occurrence of double cardiac rupture (DCR) after a successful direct infarct coronary angioplasty (DICA) is extremely uncommon. We describe herein the case of a patient who underwent delayed DICA and despite successful recanalization, subsequently suffered DCR, as a postinfarction ventricular septal defect (PIVSD) with left ventricular free wall rupture (LVFWR). Emergency surgery was performed, and the patient is now doing well more than 2 years after his operation. The possible mechanisms of DCR after delayed DICA are discussed following the presentation of this unusual case.

Aged↗
PubMed1998

A brimmed valved conduit in repair of fibrous skeleton abscess.

Aortomitral common annular involvement, which is not uncommon in infective endocarditis, necessitates deliberate surgical procedures. To repair fibrous skeleton abscess accompanied with annuloaortic ectasia, we used a brimmed valved conduit. Tension-free reconstruction of the aortic root and aortomitral common annulus was easily performed with this method.

Abscess↗
PubMed1998

CD36 abnormality and impaired myocardial long-chain fatty acid uptake in patients with hypertrophic cardiomyopathy.

Some patients with hypertrophic cardiomyopathy (HCM) demonstrate abnormal myocardial long-chain fatty acid (LCFA) metabolism. However, the exact mechanism involved is unknown. Recently, it was proposed that myocardial cells take up LCFAs via a specific mechanism, in which the CD36 molecule has been implicated as a possible candidate molecule. In addition, a high prevalence of CD36 deficiency was also found in a small number of HCM patients. Accordingly, the investigation of abnormality of the CD36 molecule in a large number of HCM patients may be useful in finding the possible cause of HCM. Moreover, the analysis of myocardial LCFA uptake in patients with molecular abnormalities may be helpful in understanding the possible function of this molecule. In this study, in order to discover the relationship between HCM and the CD36 molecular abnormality, the expression level of platelet CD36 and CD36 cDNA in 55 HCM patients was analyzed. Twelve patients showed negligible (<5%) CD36 expression on their platelets. Among them, one was found to be homozygous for the C-478-->T substitution and 6 were heterozygous for the C-478-->T substitution. In 9 patients, CD36 was expressed by less than 50% of the platelets. One of them was found to be heterozygous for the C-478-->T substitution. Two other patients were also found to be heterozygous for this point mutation, although their platelets expressed CD36. Thus, 23 out of 55 (41.8%) HCM patients had negligible (<5%) or reduced (<50%) levels of CD36 expression on platelets, or had a point mutation of CD36 cDNA. These 55 HCM patients were also evaluated with myocardial scintigraphy both for LCFA uptake and perfusion, which showed a moderate to severe discrepancy between myocardial LCFA accumulation and myocardial perfusion in 95.5% of the patients (21/23). On the other hand, 70% of the patients with normal (>90%) CD36 expression (14/20) did not show any severe discrepancies between myocardial LCFA accumulation and myocardial perfusion. These data could suggest that abnormal myocardial LCFA metabolism seen in HCM patients may be related to abnormality of the CD36 molecule, and that abnormalities of this molecule may be linked to the cause of some types of HCM.

Adult↗
PubMed1998

[Training of personnel for work in home medical care and social welfare].

Our foundation initiated another home nursing station last year, bringing to 7 the number of social welfare institutions we are running (hospital, elderly, special elderly, day service, home support center, nursing station). We are trying to maintain close communication between the institutions and local community, but service in keeping with the demand is more necessary than ever. Moreover, in supplying medical care and welfare services, we are working harder for very close communication with those on the spot. Among employees the call is also for faster, more sure communication for dealing with matters on a "quality work" basis. From the earlier attitude of local medical and welfare institutions of "Bring them here to our hospital or facility," to "We'll come there," a definite change in thinking has begun to take over now. In the home care and Welfare office end of things, while "business ability and skill" are important as ever, "attitude" has become a large factor in doing the job among employees. The report gives actual examples of training of personnel to handle these various tasks with greater ability.

Education, Nonprofessional↗
PubMed1997

Recent experience of integrated myocardial management: the newest strategy for myocardial protection.

From April 1994 until June 1996, we exclusively utilized the integrated myocardial management (IMM) proposed by Buckberg et al. at UCLA. Two hundred sixty-two consecutive patients undergoing open heart surgery at our hospital were divided into 2 groups, the non-IMM (n = 49, from July 1993 until March 1994) and the IMM (n = 213, from April 1994 until June 1996) groups. Although many older and more severely ill patients were treated with IMM, acceptable clinical outcomes with comparable safety and efficiency were obtained. Shorter durations of total cardiopulmonary bypass (CPB) and aortic cross-clamping (AXC) were needed in the IMM group despite there being many more procedures undertaken during a single cross-clamp period.

Adult↗
PubMed1997

[Quantitative evaluation of aqueous flare in psoriasis using a laser flare-cell meter].

We evaluated aqueous humor protein concentration in psoriasis using a laser flare-cell meter, which can quantify aqueous flare precisely and objectively. Psoriatic severity was evaluated on the basis of psoriasis area and severity index (PASI) score. Aqueous flare was measured in 40 eyes of 20 psoriasis patients (sixteen psoriasis vulgaris, three guttate psoriasis, and one psoriatic arthritis) and 28 eyes of 14 normal controls. Aqueous flare value was significantly higher in psoriatic patients than in normal controls (p < 0.01). There was no difference between psoriasis vulgaris and the other types of psoriasis. Aqueous flare value was higher in patients with psoriatic history longer than 10 years than in those with less than 10 years (p < 0.05), and also higher in patients with severe psoriasis (PASI score > 10) than in those with mild psoriasis (PASI score < 10) (p < 0.05). But no statistically significant differences in aqueous flare value were found among cyclosporin, etretinate, and psoralen ultra violet A therapies. These findings strongly suggest that patients suffering from psoriasis have slight damage of the blood-aqueous barrier even if they have no ocular symptoms, and that the degree of blood-aqueous barrier damage increases with time and severity of psoriasis.

Adult↗
PubMed1997

[A case report of coronary artery bypass grafting (CABG) and graft replacement of the ascending aorta for coronary artery disease associated with dissection of the ascending aorta].

A 64-year-old woman waiting for CABG for triple coronary artery disease admitted to our hospital due to chest oppression. One week after the admission, pericardiotomy was performed and blood in the pericardial effusion was found. Emergent chest CT scan revealed dissection of the ascending aorta (DeBakey II) with occluded false lumen. Because her condition was stable, concomitant operation of graft replacement of the ascending aorta and triple coronary artery bypass grafting were performed 3 months after the medical therapy. Her postoperative course was uneventful and the patient remains asymptomatic.

Aortic Dissection↗
PubMed1997

[A case of quadricuspid aortic valve associated with aortic steno-insufficiency].

A case of quadricuspid aortic valve associated with aortic steno-insufficiency was described. A 60-year-old man who had been shown to be suffering from heart murmur was admitted to our hospital. Both aortogram and echocardiogram showed a significant aortic insufficiency with mild stenosis. The aortic valve revealed 4 cusps consisting of 3 equal cusps and a smaller cusp and it had a poor coaptation and mild calcification at each commissure. The coronary orifices were normally located. Aortic valve replacement was carried out with a 25 mm St. Jude Medical valve. Histological findings showed edematous and fibrous changes. His postoperative clinical course was uneventful. Quadricuspid aortic valve is rare and the literatures were reviewed with 33 reported cases in Japan.

Aortic Valve↗
PubMed1996

[A case of isolated congenital mitral insufficiency].

A 1-year and 8-month-old girl admitted to our hospital because of wheeze and dyspnea. Echocardiogram and cardiac catheterization confirmed isolated congenital mitral insufficiency with pulmonary hypertension. She was treated with reconstructive surgery consisting of suture of clefted anterior mitral leaflet and annuloplasty. Her postoperative course was uneventual and mitral regurgitation was remarkably improved.

Female↗
PubMed1996

[The problem of 19 mm St. Jude Medical valve prosthesis in the small aortic annuls--19 mm St. Jude Medical valve vs 23 mm St. Jude Medical valve].

We compared the results of 19 mm SJM aortic valve replacements with those of 23 mm SJM aortic valve replacements conducted the same period. [Material & Method] The subjects were 21 patients who underwent valve replacement with a 19 mm SJM prosthesis (the SJM19A group). The age ranged among 16 and 65-year-old, mean of 51. The body surface area was 1.24 to 1.76 m2, mean of 1.48 m2. The post-operative follow-up period was 156 months at maximum and 44 months on average. We compared the SJM19A group with the SJM23A group by chest X-ray and echocardiography. [Results] Two patients in the SJM19A group died soon after surgery. Of the other patient, 19 were categorized NYHA I and one in NYHA II classification in their late phase. Arrhythmia of Lown IVa developed in one patient. The cardio-thoracic ratio decreased from preoperative 60% in the late phase after surgery (p < 0.002) in the SJM19A group, although there was no significant difference with that in the SJM23A group. Echocardiographic improvement in left ventricular hypertrophy was considerable between before and late after surgery in the SJM19A group, while it was not significantly different between the SJM19A and SJM23A group. The mean value of aorta-left ventricle pressure difference in the late stage was 32 mmHg in the SJM19A group and significantly different from the value in the SJM23A group (p < 0.001). This pressure difference tended to be greater as the follow-up period was progressed, while the percentage decrease in the myocardial mass of the left ventricle tended to decreased with longer follow-up period. This data suggests that an increasing level of aorta-left ventricle pressure difference should raise little problem in the mid-term late stage after surgery but possibly cause a serious problem in the long term. Clinical observation should be continued over a long period of time after surgery.

Adolescent↗