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Biomedical subjects

Y Yokote

Publications and source records attributed to Y Yokote.

At least 19 recordsLinked to original sources
PubMed2005

Possible link between glycolysis and apoptosis induced by sodium fluoride.

Fluoride has been used to prevent caries in the dentition, but the possible underlying mechanisms of cytotoxicity induction by this compound are still unclear. Since fluoride is known as an inhibitor of glycolytic enzymes, we investigated the possible connection between NaF-induced apoptosis and glycolysis in human promyelocytic leukemia HL-60 cells. NaF-induced apoptotic cell death is characterized by caspase activation, internucleosomal DNA fragmentation, loss of mitochondrial membrane potential, and production of apoptotic bodies. Higher activation of caspases-3 and -9, as compared with that of caspase-8, suggested the involvement of an extrinsic pathway. Utilization of glucose was nearly halted by NaF, whereas that of glutamine was rather enhanced. NaF enhanced the expression of Bad protein, but not that of Bcl-2 and Bax proteins, and reduced HIF-1alpha mRNA expression. Analysis of these data suggests a possible link between glycolysis and apoptosis.

Apoptosis↗
PubMed2005

[Traumatic rupture of the ascending aorta].

A 42-year-old male was diagnosed as having a traumatic rupture of the ascending aorta 24 hours after traffic accident. On admission, the patient was in a state of shock, but he was successfully treated by emergency surgery. Traumatic rupture of the ascending aorta is a serious condition and the mortality may be very high. Although physicians rarely encounter patients with this condition, it is relatively common among autopsy cases with multiple trauma. Urgent diagnosis and treatment are mandatory.

Adult↗
PubMed2005

[Aortic root remodeling and coronary artery bypass grafting for acute type A aortic dissection involving the left main coronary artery; report of a case].

A 56-year-old male was admitted for sudden chest pain followed by loss of consciousness and paraplegia. The electrocardiogram (ECG) revealed ST-elevation in leads II, III, and aVF and ST-depression in leads V3 to V6. The ultrasonic cardiography (UCG) demonstrated an intimal flap in the ascending aorta, grade III aortic regurgitation (AR), and akinesis of the posterior wall of the left ventricle. Transesophageal echocardiography directly showed dissection of the left main coronary artery. Emergency coronary artery bypass grafting (CABG) to the left anterior descending artery (LAD), obtuse marginal artery (OM) and posterolateral artery (PL) was performed using the saphenous vein. In addition, valve-sparing aortic root remodeling was performed in conjunction with replacement of the ascending aorta. The left coronary orifice was repaired and reattached to the prosthetic graft. The patient was weaned from cardiopulmonary bypass without catecholamine support. He was discharged from the hospital on foot after rehabilitation of the paraplegia. AR remains mild by UCG 3 years after surgery.

Acute Disease↗
PubMed2004

Left ventricular outflow obstruction after Fontan procedure involving a patient with complete atrioventricular septal defects complicated by a small left ventricle.

We report a 1-year-old girl who developed ventricular outflow tract obstruction early after a Fontan operation, necessitating surgical relief using the Damus-Kaye-Stansel procedure. The patient had a complete atrioventricular septal defect complicated by a muscular ventricular septal defect (VSD) and a small left ventricle, a morphology that has not previously been reported in cases of systemic outflow tract obstruction after the Fontan procedure. Postoperative systemic outflow obstruction must be considered as a possible sequela following Fontan surgery in patients with an atrioventricular septal defect and a small left ventricle.

Aftercare↗
PubMed2004

[Long survival with chronic ventricular fibrillation under support of uni-left-ventricular assist system].

Few minutes of suspended malignant ventricular arrhythmia may be permitted for the patient with left ventricular assist system (LVAS). However, longer and continuous ventricular arrhythmia, especially ventricular fibrillation (Vf), may induce the low output of LVAS, which leads circulatory collapse immediately. Our presenting case is a female dilated cardiomyopathy patient who has been supported with LVAS. Four months after the LVAS installation, her electrocardiogram has changed to Vf without any symptoms. Her ventricular function has never recovered, even ventricular tachycardia. She has been a candidate of heart transplantation for more than 19 months with this rare hemodynamic condition (LVAS+Vf), like the Fontan circulation. Her performance status is limited due to deceasing of the LVAS flow, which caused by the change of her position: 2.5-2.9 l/min (lie down) to 2.0 l/min (rise). Her peak VO2/W is 6.9 ml/min/kg measured by the cardio-pulmonary exercise test. However, she has developed her general status by doing rehabilitation program and is able to walk for more than 100-150 meters.

Adult↗
PubMed2004

[Infective endocarditis caused by methicillin resistant Staphylococcus aureus following corticosteroid pulse therapy; report of a case].

A 51-year-old man, with a history of corticosteroid pulse therapy 3 weeks previously, developed infective endocarditis of the mitral valve due to methicillin resistant Staphylococcus aureus, and underwent mitral valve replacement. Since the second postoperative day, clinical course was seriously complicated because of recurrent abdominal pain corresponding with commencement of oral intake, unremitting spike fever, and renal and hepatic dysfunction. Various examinations except angiography failed to demonstrate the etiology. Two months later, the patient developed panperitonitis due to perforation of ischemic ulcer of the cecum and underwent ileo-cecal resection. After this operation, he convalesced very quickly. Ischemia is one of the main causes of abdominal complication following cardiac surgery. Angiography should be positively considered in cases like the present one.

Abdominal Pain↗
PubMed2003

[Stent-graft implantation for the patient with ruptured acute aortic syndrome: report of a case].

We report a ruptured case of acute aortic syndrome and a successful treatment with transcatheter placed stent-graft. A 67-year-old man underwent a stent-graft implantation for the patient with ruptured acute aortic syndrome. The patient admitted in our institute for a diagnosis of ruptured acute aortic dissection. We planned to operate a graft replacement for distal arch aorta. But he was complicated with right-side monoplesia before the operation. Then we performed a stent-graft implantation in order to avoid the usage of extra-corporeal circulation. The implantation of the stent-graft was successful and shrinkage of the hematoma around the ruptured aorta was documented on the computed tomography of 7 post-operative day.

Acute Disease↗
PubMed2002

[A report of initial clinical use of left ventricular assist system with left ventricular inflow cannula for acute myocardial infarction].

Previous clinical results of left ventricular assist system (LVAS) therapy for cardiogenic shock due to acute myocardial infarction (AMI) are still unacceptable. Japanese LVAS was designed for left atrial inflow cannulation. However, to obtain higher initial LVAS flow and more decompression of left ventricular (LV) cavity and to avoid thromboembolic event, LV inflow cannulation is a preferable procedure. Therefore, LV inflow cannula for Japanese LVAS (Toyobo) was developed. We treated three AMI cases with Toyobo-LVAS using the new LV inflow cannula. All patients were in cardiogenic shock status since broad antero-septal AMI and treated with percutaneous cardio-pulmonary support before the LVAS installation. The LVAS was effective for recovery from cardiogenic shock status and multiple organ failure. Two patients died because of serious LVAS associated complications such as bleeding (case 1, 8 days) and cerebral thromboembolism (case 2, 45 days). One of them was assisted for 202 days and underwent second operation. Sixty days after removal of LVAS, the patient died due to sepsis. The technique of LV inflow cannulation is improved through our experiences. However, our result suggests that renovation of the regimen for anti-coagulation and anti-septic therapy are necessary.

Aged↗
PubMed2001

Circulating matrix metalloproteinases and their inhibitors in patients with Kawasaki disease.

BACKGROUND: Accelerated matrix breakdown caused by the increased activity of matrix metalloproteinases (MMPs) and/or the quantitative imbalance between MMP and tissue inhibitor of MMP (TIMP) have been implicated in several pathological conditions. MMP and TIMP may also be involved in the destruction of the coronary arterial wall and the resultant coronary arterial lesions in Kawasaki disease. METHODS AND RESULTS: Plasma levels of MMPs, neutrophil elastase, and TIMPs were measured by enzyme-linked immunoassay in 57 patients with Kawasaki disease and no coronary arterial lesions (group 1) and in 8 patients with Kawasaki disease and coronary arterial lesions (group 2). Blood samples were obtained before and after intravenous gamma globulin therapy and in the convalescent stage. Levels of MMPs, neutrophil elastase, and TIMPs were significantly higher in Kawasaki disease patients before gamma globulin therapy than in 18 age-matched afebrile control subjects and 17 age-matched febrile disease control subjects (P<0.01). More importantly, the pre-gamma globulin MMP9 level and MMP9/TIMP2 ratio and post-gamma globulin MMP3 level and MMP3/TIMP1 ratio were significantly higher in group 2 than in group 1 patients (P<0.05). Although MMP levels in febrile disease controls were significantly higher than those of afebrile controls, the MMP/TIMP ratios of febrile disease controls and afebrile controls were comparable. CONCLUSIONS: These data suggest that patients with Kawasaki disease and high levels of MMP and/or MMP/TIMP are susceptible to coronary arterial lesions. Studies of the effects of MMP inhibitors on coronary outcome may provide evidence that MMP is a viable therapeutic target for the prevention of coronary arterial lesions due to Kawasaki disease.

Child, Preschool↗
PubMed2001

Inferior vena cava occlusion catheter for pediatric patients with heart disease: for more detailed cardiovascular assessments.

Traditional evaluation of cardiac function is too often limited by reliance on measurements with complex interdependence between cardiac properties and loading factors. Analysis by ventricular pressure-volume (P-V), -area (P-A), or -dimension (P-D) relations during inferior vena caval (IVC) occlusion independently quantifies ventricular properties and loading conditions, providing detailed information about cardiovascular dynamics. However, there has been no appropriate size of balloon catheter that can effectively occlude IVC of pediatric patients, hindering the application of P-V (P-A, or P-D) analysis to children with heart disease despite its potential benefit. To address this problem, we have developed a new balloon catheter for IVC occlusion in children. The catheter effectively occluded IVC in 92 pediatric patients with varying forms of heart disease who underwent cardiac catheterization, yielding end-systolic pressure-area relations. Thus a newly developed balloon catheter would contribute to establishing more accurate and detailed cardiovascular assessments in children with heart disease. Cathet Cardiovasc Intervent 2001;53:392-396.

Adolescent↗
PubMed2001

Combined coronary intervention in heart-transplant patient with rapidly accelerated cardiac allograft vasculopathy.

A 46-year-old man accepted for heart transplantation due to persistent cardiac failure from dilated cardiomyopathy underwent a transplant in Germany on July 13, 1995. The donor heart was suspected of coronary artery disease at explantation, but he could wait no longer because of his rapidly deteriorating hemodynamics. Postoperative coronary angiography revealed 25% stenosis of the left descending artery. He showed several episodes of minimal or moderate rejection postoperatively, and coronary angiography 15 months postoperatively showed rapidly accelerated cardiac allograft vasculopathy demonstrating triple vessel disease with multiple lesions. Percutaneous transluminal coronary angioplasty was successful on 2 coronary vessels, but immediately recurrent stenosis and new lesions involving the left main trunk occurred 6 weeks thereafter. Since he was financially unable to afford a second heart transplantation, quadruple coronary artery bypass grafting was conducted October 25, 1996. A biventricular assist device was used when he could not be weaned from cardiopulmonary bypass. He died of multiple organ failure 3 days after surgery.

Angioplasty, Balloon, Coronary↗
PubMed2001

Aortobiventricular fistulas associated with pseudoaneurysm of the ascending aorta 12 years after patch repair of supravalvular aortic stenosis.

Fistula formation between the aorta and cardiac chamber is a rare complication of the ascending aortic aneurysm. A 27 year-old man undergoing successful patch aortoplasty for supravalvular aortic stenosis 12 years before admission had a high fever, infectious signs in blood laboratory data, and congestive heart failure. Transthoracic and transesophageal echocardiography revealed a pseudoaneurysm of the aortic root and aortobiventricular fistulas. Detachment of the proximal end of the aortic patch was thought to be the cause of the pseudoaneurysm. Debridement of necrotic tissue surrounding fistulas produced large defects in the anterior wall of the right ventricle, interventricular septum, and ascending aorta. A modified Konno operation effectively reconstructed the outflow tracts of both ventricles and the aorta.

Adult↗
PubMed2001

Assessment of cardiovascular dynamics by pressure-area relations in pediatric patients with congenital heart disease.

OBJECTIVES: It is particularly useful to separately quantify the ventricular contractility and loading conditions for a better understanding of the cardiovascular dynamics in congenital heart disease, where abnormalities in chamber and loading properties may coexist. Furthermore, ventricular contractility and loading conditions may alter independently or simultaneously with disease progression and therapeutic intervention. The objectives of the present study were (1) to test whether ventricular pressure-area analysis can provide such quantitation among patients with various forms of congenital heart disease, (2) to reveal basal cardiovascular interaction in congenital heart disease by means of pressure-area analysis, and (3) to test the feasibility of this method in a simplified and less invasive form to further enhance its clinical value. METHODS: We constructed pressure-area loops during caval occlusion by using transthoracic echocardiographic automated border detection combined with ventricular pressure recordings in 59 pediatric patients with congenital heart disease and in 7 normal control subjects. RESULTS: Area measurements obtained by automated border detection were highly reproducible, and area changes reflected volume changes. The pressure-area data provided load-independent measures of contractility, which were consistently increased by use of dobutamine (P <.05). End-systolic and arterial elastance individually quantified simultaneous changes in ventricular contractility and loading with milrinone infusion and predicted net cardiac performance. The pressure-area analysis better characterized the ventricular contractile states under a variety of loading conditions in congenital heart disease, whereas predominant load dependence of conventional indices confounded them. Furthermore, pressure-area relations were reasonably estimated from a single beat and from aortic pressure data during abdominal compression. CONCLUSIONS: Pressure-area analysis should provide a useful modality with which to assess cardiovascular dynamics in pediatric patients with congenital heart disease in more detail and should thus help improve the management of patients with this disease.

Adolescent↗
PubMed2001

[High pressure occlusion of leukocyte depletion arterial line filter in patients with cardio-pulmonary bypass surgery].

Cardio-pulmonary bypass (CPB) leads the activation of neutrophil, which may cause reperfusion organ dysfunction. Utility of using the leukocyte depletion arterial filter to pretend postoperative complications has been reported. The other side, the risk of the leukocyte depletion filter occlusion with high-pressures of CPB arterial line (high-pressure occlusion) has been noted. We used the leukocyte deletion filter (LG-6, Pall), and experienced two cases of high-pressure occlusion in 421 CPB surgery with LG-6 (0.48%). No high-pressure occlusion was occurred with 1,508 patients used the standard arterial line filter in it period (0%, p = 0.007). In the both cases of high-pressure occlusion, monitored arterial line pressure increased to over 340 mmHg within 10 minutes after CPB installation. The filters were changed to standard type, then no more filter trouble was occurred. In the second case, we inspected the occluded LG-6. Light microscopic survey showed eosin stained small spherical cells (HE) and negative for fibrin (PTAH). Electromicroscopy revealed that spherical cells (1-2 microns) adherated to structure of the filter. No fibrin was detected with Gel electrophoresis. Because of the pathologic analysis, the cells, which might cause the filter occlusion, were platelet. In addition, no fibrin exist suggests that the coagulation system did not relate to the high-pressure occlusion. In conclusion, we experienced two high-pressure occlusion cases of the leukocyte depletion arterial filter with CPB surgery (0.48%); the filter occlusion may be caused by the initial thrombus formation by platelet.

Aged↗
PubMed2000

Clinical effects of ventricular assist system in end-stage cardiac failure. Advantages of left ventricular blood drainage for recovery from cardiac dysfunction.

OBJECTIVES: Heart transplantation is extremely limited currently in Japan. As a consequence ventricular assist system implantation is employed the patient falls into end-stage cardiogenic shock. This preliminary report describes our initial clinical experience with use of 2 kinds of ventricular assist system for 13 Japanese patients. METHODS: 7 patients were supported by a left ventricular assist system with blood drainage from the left atrium (LA drainage Group) using a Toyobo ventricular assist system, while another 6 patients were supported by a left ventricular assist system with blood drainage from the left ventricle (LV drainage Group) using the Toyobo ventricular assist system (1 patient) or TCI-LVAS (5 patients). RESULTS: The average duration of ventricular assist system support in the LV drainage Group was 112 days including two on-going patients (now at 39 days and 241 days) and in the LA drainage Group was 49 days. The average left ventricular ejection fraction at 3 weeks after ventricular assist system implantation was improved from 12.3 to 54% using the TCI-LVAS and from 14 to 33% using the Toyobo ventricular assist system with drainage from the left ventricle. However, this was decreased from 20 to 10% using the Toyobo ventricular assist system with drainage from the left atrium. The ventricular assist system was explanted in 4 patients (31%) with recovery of cardiac dysfunction and 3 were long survivors. The 2 on-going patients are awaiting heart transplantation. Thus the current survival rate overall is 38%. The survival rate (67%) is excellent in the LV drainage Group including 2 long survivors after explantation. CONCLUSION: Ventricular assist system support with drainage from the left ventricle seems to be more advantageous for cardiac functional recovery than from the left atrium for end-stage heart failure.

Adult↗