Search PubMed⌕ Search

Biomedical subjects

Haruhiko Asano

Publications and source records attributed to Haruhiko Asano.

At least 37 records · Page 2Linked to original sources
PubMed2004

[Surgical treatment of active infective endocarditis: analysis of 20 years' experience].

OBJECTIVES: Changes in perioperative condition and outcomes of surgically treated patients with active infective endocarditis were evaluated during the last 20 years. METHODS: Between 1983 and 2002, 132 patients with active infective endocarditis underwent surgery at Saitama Medical School. Changes in frequency, pathogens, clinical features, surgical results, and perioperative treatment were compared between four periods of 5 years. RESULTS: The percentage of surgery for infective endocarditis remained almost the same among all cardiovascular procedures. Staphylococcal infective endocarditis increased significantly (p < 0.01), and prosthetic valve infective endocarditis and periannular abscess became more common. Surgery tended to be performed in severely ill patients significantly more frequently (p < 0.01). If all patients were included, hospital mortality did not decrease significantly, at 1.7% in stable patients, but 50% in critically ill patients. Intensive care unit stay became relatively longer. Recurrent infection was observed significantly more frequently in critically ill patients and in patients with prosthetic valve infective endocarditis. Patients were referred for surgery following diagnosis and underwent surgery at increasingly more appropriate timing. However, the diagnosis of infective endocarditis took 1.5 months to establish regardless of the patient's condition or the clinical outcome. Moreover, antibiotics were administered orally in around 90% and intravenously in nearly 70% of the patients without microbiological tests, and negative cultures remained very frequent. CONCLUSIONS: Critically ill patients underwent surgery increasingly more frequently, and surgical outcomes remained unsatisfactory over the last 20 years. Early diagnosis and avoidance of premature antibiotic therapy may be important for future improvement.

Endocarditis, Bacterial↗
PubMed2004

[Pseudoaneurysm of the left ventricle following suppurative pericarditis and sepsis due to Staphylococcus aureus: a case report].

A 35-year-old diabetic man presented with a left ventricular aneurysm very close to the mitral valve annulus. He had been conservatively treated for suppurative pericarditis and sepsis due to Staphylococcus aureus during the previous 3 weeks. The left ventricular aneurysm rapidly enlarged (6 cm in diameter) and the patient underwent emergent surgery. Cardiopulmonary bypass and cardioplegic arrest were induced, and the left ventricular aneurysm orifice was closed with a double layer of autologous pericardium. Mitral valve function was not impaired. He has been doing well for 4 years. Surgery is indicated as soon as possible after the diagnosis of infective left ventricular aneurysm.

Adult↗
PubMed2003

Regulation of sphingosine kinase 1 gene expression by protein kinase C in a human leukemia cell line, MEG-O1.

The prolonged treatment with phorbol 12-myristate 13-acetate (PMA) of a human megakaryoblastic leukemia cell line, MEG-O1, induced increase of sphingosine kinase (SPHK) enzyme activity and SPHK1 protein expression as well as SPHK1 message. Protein kinase C (PKC) inhibitor prevented the PMA-induced SPHK1 gene expression. To elucidate the regulatory mechanism of this gene expression, we examined the promoter area (distal to the first exon) and its binding proteins. Luciferase analyses showed that the area of 300 bp from the first exon was sufficient for PMA-responsiveness, and that specificity protein 1 (Sp1)- and two activator protein 2 (AP-2)-binding motifs within this area were necessary for responsiveness. Inhibitors for PKC and MEK1 decreased this PMA-induced promoter activity. Electrophoresis mobility shift assay (EMSA) showed that Sp1 protein was originally bound to the Sp1 site and that two additional bands bound to the two AP-2 motifs were observed only when stimulated with PMA in MEG-O1 cells. The appearance of these bands resulted from binding to an unknown protein rather than AP-2. These results indicated that PMA up-regulates SPHK1 gene expression through PMA-responsive elements of the 5' promoter area of the gene, and suggested that PMA-mediated SPHK1 gene expression would be mediated via PKC- and ERK-dependent signal transduction pathway by binding the transcription factor to AP-2 motifs.

Binding Sites↗
PubMed2003

Combined coronary artery bypass grafting and abdominal aortic aneurysm repair.

The purpose of this paper was to assess the results and feasibility of simultaneous coronary artery bypass grafting and abdominal aortic aneurysm repair. Twenty nine patients with a mean age of 65 years underwent simultaneous coronary artery bypass grafting and abdominal aortic aneurysm repair between June 1990 and March 2002. All patients had significant coronary artery disease and were considered as indicated for coronary artery bypass grafting. This was performed first in 28 patients and simultaneously with abdominal aortic aneurysm repair in one, with a mean number of grafts of 2.5, a mean aortic cross-clamp time of 40 minutes, and a mean bypass time of 115 minutes. Eight straight and 21 bifurcated grafts were employed. The total operating time averaged 400 minutes. The median postoperative hospital stay was 18 days. One patient died of stroke and mediastinitis, for a mortality rate of 3.5%. This experience suggests that combined coronary artery bypass grafting and abdominal aortic aneurysm repair is both safe and effective.

Adult↗
PubMed2003

Noncardioplegic surgery for ischemic mitral regurgitation.

Twenty-seven consecutive patients underwent surgery for ischemic mitral regurgitation (MR): papillary muscle rupture (1), papillary muscle dysfunction (11) and annular dilatation (15). The grade of MR was moderate or severe, and the ejection fraction (EF) was less than 30% in 8 patients (mean, 43%). Three cases were reoperation and 3 were emergencies. Under ventricular fibrillation (VF) and intermittent aortic cross-clamping at moderate hypothermia, coronary artery bypass grafting (CABG) was performed first, followed by the mitral procedure through a right-sided left atriotomy (repair 21, replacement 6) performed under VF with the heart perfused through the native coronary arteries and CABG grafts. Concomitant procedures were CABG (23), Dor's procedure (5), and tricuspid annuloplasty (3). In one reoperative case with cardiogenic shock, CABG was impossible because of dense adhesions and the patient died just after surgery (hospital mortality, 3.7%). Five patients required intra-aortic balloon pump (IABP) support intraoperatively, but none required prolonged (> or =7 days) inotropic support or IABP use, although the serum concentrations of creatine kinase and its myocardial fraction were elevated remarkably. Other morbid events were refractory ventricular arrhythmia in one case and stroke in another. Median duration of mechanical ventilation and intensive care unit stay was 8 h and 3 days, respectively. Mean EF at hospital discharge was 48%. The extended period of VF was not associated with unfavorable clinical outcomes. Noncardioplegic surgery for ischemic MR was carried out with acceptable mortality and morbidity, and can be a good alternative, especially when clamping the aorta is undesirable.

Aged↗
PubMed2003

Mid-term results of aortoplasty for dilated ascending aorta associated with aortic valve disease.

BACKGROUND: Dilatation of the ascending aorta concomitant with aortic valve disease is occasionally associated with progressive enlargement of the ascending aorta or acute aortic dissection (AAD). However, surgical procedure of choice for the aorta and its indication are controversial. PATIENTS AND METHODS: From July 1995 to August 2001, 10 patients with a moderately dilated ascending aorta (mean diameter, 52+/-4.8 mm) underwent concurrent aortic valve replacement (AVR) and aortoplasty. The aortic valve was bicuspid in eight patients. To tailor the ascending aorta 30-35 mm in diameter, the aortic wall was partially resected along the aortotomy, and the aorta was directly closed. RESULTS: Operation time and most of other perioperative variables were comparable to those of patients who underwent isolated AVR. The aortic diameter was reduced to 36.1+/-4.1 mm. Nine patients survived to hospital discharge uneventfully, but one patient developed disruption of the suture line in the aorta and died. During follow-up, no patient suffered AAD but redilatation was observed in one patient. In the two problematic patients, the ascending aorta was larger than 55 mm, and its media was histologically abnormal. CONCLUSION: In patients with dilated ascending aorta less than 55 mm in diameter, aortoplasty can be a procedure of choice. However, a prosthetic graft replacement is recommended when the diameter of the ascending aorta is larger than 55 mm.

Adult↗
PubMed2002

Ventricular afterload and ventricular work in fontan circulation: comparison with normal two-ventricle circulation and single-ventricle circulation with blalock-taussig shunts.

BACKGROUND: Recent studies have indicated that there are inherent limitations associated with Fontan physiology. However, there have been no quantitative analyses of the effects of right heart bypass on ventricular afterload, hydraulic power, and resultant overall hemodynamics. Methods and Results- During routine cardiac catheterization, aortic impedance and ventricular hydraulic power were determined, both at rest and under increased ventricular work induced by dobutamine, in 17 patients with Fontan circulation, 15 patients with a single ventricle whose pulmonary circulation was maintained only by Blalock-Taussig shunts, and 13 patients who had normal 2-ventricle circulation. Both vascular resistance (nonpulsatile load on the ventricle) and pulsatile components of ventricular afterload (represented by low-frequency impedance) were significantly higher in the Fontan group than in the other groups (P<0.01), and this was associated with decreased cardiac output in the Fontan patients. In addition, hydraulic power cost per unit forward flow was 40% lower in the 2-ventricle circulation than in the single-ventricle circulation, suggesting lower ventricular efficiency in single-ventricle circulation attributable to the lack of a pulmonary ventricle. Furthermore, in the Fontan group, beta-adrenergic reserve was markedly decreased because of a limited preload reserve. CONCLUSIONS: Fontan physiology is associated with disadvantageous ventricular power and afterload profiles and has limited ventricular reserve capacity. Thus, to improve the long-term prognosis of patients after Fontan surgery, future research should be conducted into medical interventions that can overcome these limitations inherent in Fontan circulation.

Adrenergic beta-Agonists↗
PubMed2002

Up-regulation of acid sphingomyelinase during retinoic acid-induced myeloid differentiation of NB4, a human acute promyelocytic leukemia cell line.

All-trans-retinoic acid (ATRA) induces myeloid differentiation of a human promyelocytic leukemia cell line, NB4, but does not affect its subclone NB4/RA harboring a point-mutated ligand-binding domain (AF2) in retinoic acid receptor alpha (RARalpha) gene. We found that ATRA induced the 4-fold elevation of acid sphingomyelinase (ASMase) activity 24 h after treatment in NB4 cells, but not in NB4/RA cells. ATRA did not affect neutral sphingomyelinase activity in either NB4 or NB4/RA. Upon treatment with ATRA, ceramide, the product of an ASMase reaction, accumulated in NB4 cells. Northern blot analysis showed a marked elevation of the ASMase mRNA 8 h after ATRA treatment, reaching a plateau at 24 h. Regulation of ASMase gene expression was studied by a promoter analysis using luciferase reporter assay. The 5'-upstream flanking region of human ASMase gene (-519/+300) conjugated with the luciferase gene was introduced into COS-7 cells. Luciferase activity in transformed cells markedly increased in response to ATRA stimulation when the wild type RARalpha or the PML/RARalpha hybrid protein was co-expressed. Deletion experiments revealed that a short sequence at the 5'-end (-519/-485) was indispensable for the ATRA response. Within this short region, two retinoic acid-responsive element-like motifs (TGCCCG and TCTCCT) and one AP2-like motif (CCCTTCCC) were identified. Deletion and base-substitution experiments showed that all three motifs are required for the full expression induced by ATRA. Electrophoresis mobility shift assays with the nuclear extract of ATRA-treated NB4 cells showed that proteins were bound specifically to the probe being mediated by all three motifs in the promoter sequence.

Amino Acid Motifs↗
PubMed2002

Allograft pulmonary artery root replacement for refractory isolated pulmonic valve endocarditis.

A 45-year-old diabetic woman was subjected to percutaneous cardiopulmonary support for a life-threatening pulmonary embolism. One month later, she developed isolated pulmonic valve endocarditis. The causative organism was methicillin-resistant Staphylococcus aureus. Because of the uncontrollable infection and residual pulmonary hypertension, she underwent pulmonary artery root replacement with a cryopreserved pulmonary allograft. The postoperative course was very good. In this case, allograft implantation with a full root played a very important role because this method permitted thorough resection of the infected tissues and reconstruction which is highly resistant to infection.

Angiography↗
PubMed2002

The MAGE-A1 gene expression is not determined solely by methylation status of the promoter region in hematological malignancies.

Tumor antigens such as MAGE-A1 are aberrantly expressed in many human tumors and could be recognized by CTL. Thus, they could be targets for cancer immunotherapy. It is presently considered that the expression of the MAGE-A1 gene is regulated by methylation of its promoter region. To estimate the possibility of activating the MAGE-A1 gene with demethylating agents with a view toward clinical use, we assessed the methylation status of its CpG-rich promoter by sodium bisulfite mapping both of samples that express the gene and those that do not. Cell lines and samples from patients with hematological malignancies were examined. Surprisingly, the methylation status of the MAGE-A1 gene did not clearly correlate with the expression of the gene. Our results indicate that the MAGE-A1 gene expression is not determined solely by the methylation status of the promoter region in hematological malignancies.

Antigens, Neoplasm↗
PubMed2002

Mitral valve surgery under perfused ventricular fibrillation with moderate hypothermia.

The safety and myocardial protective effect of perfused ventricular fibrillation (VF) under moderate hypothermia were investigated. Through a midline sternotomy and opening the left atrium from the right side, isolated mitral valve surgery was performed under aortic cross-clamping (ACC) and cardioplegic arrest using Bretschneider HTK solution in 96 patients, and under perfused VF in 20 patients (VF Group). Patient characteristics, clinical outcomes, and perioperative variables were compared. A satisfactory surgical view was obtained in all VF Group patients. Patient characteristics in the 2 groups were similar, and both groups had comparable results for mortality and morbidity, operation time, cardiopulmonary bypass time, peak levels of creatine kinase (CK) and its myocardial fraction, hours of mechanical ventilation, intensive care unit stay, and postoperative left ventricular ejection fraction. Even in VF Group patients with preoperative critical hemodynamic compromise, inotropes could be discontinued within 3 days. Thus, no detrimental effect of perfused VF was observed. On the other hand, in patients who underwent ACC and cardioplegic arrest of 120min or longer, peak levels of CK and its myocardial fraction were significantly higher than those of the rest of C group patients and VF Group patients. Perfused VF under moderate hypothermia can be a good alternative myocardial protection strategy during mitral valve surgery, particularly in patients in whom ACC is unsuitable or the duration of ACC is expected to be long.

Adult↗
PubMed2002

The efficacy and safety of additional bypass graft during isolated coronary artery bypass grafting.

In 19 patients with an undesirable hemodynamic condition (n=15) or with regional asynergy and coexistent ST-T change (n=4) during isolated coronary artery bypass grafting (CABG) surgery, one (n=17) or two (n=3) additional saphenous vein grafts were placed onto left anterior descending (LAD) (n=16), right (n=4), and left circumflex (LCx) (n=2) coronary arteries. Diagnosis of the cause of the suboptimal condition was insufficient graft flow in 16 patients, and spasm of the ungrafted coronary artery in 3. Additional myocardial ischemic time was 17 9 minutes, and the graft flow was 59 25 ml/min. Additional bypass was effective in 94.5%. Eighteen patients could be weaned from cardiopulmonary bypass, and 17 (89.5%) survived and were discharged from hospital. Median duration of mechanical ventilatory support and intensive care unit stay was 15 hours and 4 days, respectively. During 63 44 months follow-up, the additional graft was occluded and the treadmill test was positive for ischemia in 2 patients, and one child patient is now considered for redo CABG. Placement of additional bypass grafts thus appeared to be an effective and relatively safe strategy, although the decision has to be made cautiously.

Adolescent↗
PubMed2002

[Left ventricular assist system].

Two types of artificial heart, the total artificial heart (TAH) and ventricular assist system (VAS), have been utilized in patients with end-stage heart failure waiting for heart transplantation (bridge to transplantation). The TAH is a system to replace the native heart, whereas the VAS is a system to support the left ventricle (LVAS), right ventricle (RVAS), or both ventricles (BVAS) while maintaining native cardiac function. There are two types of VAS, paracorporeal VAS and implantable VAS. Implantable VAS devices such as Novacor LVAS and HeartMate LVAS are only available for LVAS, although paracorporeal VAS, such as Toyobo VAS, Zeon VAS, and Thoratec VAS, are available for RVAS, LVAS, or BVAS. Due to recent advances in the VAS, the "patient discharge program" from hospital has been promoted for improvement of the quality of life (QOL) and reduction of medical costs. VAS also have been utilized as "bridges to recovery" for native hearts or for "semipermanent use" in patients without indications for heart transplantation, and superior clinical results of VAS therapy compared with conservative therapy have been reported in terms of one-year survival rate and improvement of QOL. Recently, several inexpensive VAS systems with an axial or centrifugal pump have been developed and the initial clinical trials of these systems have recently started in Western countries. Another remarkable technological advance in VAS is the Lion Heart (Arrow) which is a totally implantable VAS system the includes an energy transmission system. We expect that recent technological progress in VAS will improve the survival and QOL in patients with end-stage heart failure.

Heart Failure↗