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Biomedical subjects

M Kashida

Publications and source records attributed to M Kashida.

At least 19 recordsLinked to original sources

Myopericarditis caused by cyclophosphamide used to mobilize peripheral blood stem cells in a myeloma patient with renal failure.

Cyclophosphamide (CPA) is widely used for peripheral blood stem cell mobilization, and a dose adjustment of CPA in the presence of renal failure has not been suggested. However, we describe a myeloma patient with renal failure (serum creatinine 4.2 mg/dl, creatinine clearance 11.2 ml/min) receiving CPA 2 g/m2 for 2 days, who developed unexpectedly severe toxicity, including myopericarditis and prolonged myelosuppression. The serial serum concentrations of CPA metabolites were persistently much higher than those in a myeloma patient with normal renal function. We consider, therefore, that the dose of CPA should be reduced in the presence of severe renal failure when used as high-dose therapy or to mobilize peripheral blood stem cells.

Adult↗

Possible mechanism of ECG features in patients with idiopathic ventricular fibrillation studied by heart model and computer simulation.

The possible contribution of localized conduction delay and abnormal action potentials to ventricular fibrillation (VF) was studied by applying an anisotropic cardiac computer model to clinical cases of the Brugada-type electrocardiogram (ECG), which shows right bundle branch block (RBBB), a normal QT interval, ST-segment elevation, and late r' in leads V1 and V2. The anisotropic heart model was composed of 50,000 discrete units with a spatial resolution of 1.5 mm and was mounted in a human torso model. The longitudinal/transverse conduction velocity ratio was 3:1. For the normal ECG, a conduction velocity of 0.75 m/s was required. In the abnormal area of the right anterior epicardial wall, the conduction velocity was set at 0.2 m/s, with decreasing action potential amplitude and 10% prolonged action potential duration. The ECG features of ST-segment elevation and Brugada-type right bundle branch block pattern were simulated. The action potential duration was able to change dynamically with coupling interval of stimulation, with a ratio of 9% for normal ventricular muscle and 50% for Purkinje fibers. Five successive stimuli were applied to the left lateral epicardium 300 ms after the first sinus excitation, and sustained VF was induced with the transmural conduction delay at the right anterior ventricle as a block increasing the vulnerability. At the initiation of VF, reentry circuits were shown around the border zone of the right epicardium and were very heterogeneous around the conduction delayed area and septal area. In an area with the characteristics of nontransmural conduction delay, sustained VF was prevented, and the pattern of transient right bundle branch block appeared on the simulated ECG and body surface potential maps. The late r' wave was calculated in the precordial leads and right anterior site on the body surface potential maps. These results suggest that increased multipolarity in the border zone between the Purkinje fibers and delayed conduction area in the right ventricle might play an important role as a functional block for the persistence of VF.

Action Potentials↗

Correlations between resting regional wall motion and regional myocardial blood flow (at rest and during exercise) in infarct-related myocardium--a study with [13N]ammonia positron emission tomography.

We evaluated quantitatively the correlations between resting wall motion and regional myocardial blood flow (RMBF; at rest and during exercise) in infarct-related myocardium. The study was performed in 28 subjects: 21 patients who had previously suffered myocardial infarction of the anteroseptal wall, and 7 normal individuals. Positron emission tomography (PET) with [13N]ammonia was performed at rest and during low-grade exercise (bicycle ergometer fixed at 25 W for 6.5 min), and RMBF was measured quantitatively from the radioactivity in myocardial tissue and arterial blood. Resting regional wall motion was calculated using the centerline method on left ventriculographic findings. Resting regional wall motion was correlated with RMBF both at rest and during exercise in the infarct areas (anterior walls; y = 2.74 +/- 4.25 x 10(-2)x, r = 0.43, at rest; and y = -2.48 + 3.04 x 10(-2)x, r = 0.48, during exercise, p < 0.05; septal walls; y = -3.61 + 5.64 x 10(-2)x, r = 0.62, at rest; and y = -3.46 + 4.31 x 10(-2)x, r = 0.62, during exercise, p < 0.01). In each infarct-related wall, the coefficient (the slope) during exercise was smaller than that at rest (3.04 vs 4.25 and 4.31 vs 5.64 in each), and the infarct areas with preserved wall motion showed higher RMBF during exercise than those with reduced wall motion. Our results may show that wall motion depends on viable but ischemic myocardium in infarct-related walls.

Adult↗

Functional role of coronary collaterals with exercise in infarct-related myocardium.

We evaluated the regional myocardial blood flow in collateral dependent infarct-related areas to examine the functional role of coronary collaterals. Regional myocardial blood flow was measured by positron emission tomography with 13N-ammonia at rest and during low-grade exercise (bicycle ergometer fixed at 25 W for 6.5 min). The study was performed in 24 subjects, consisting of 19 patients with prior myocardial infarction, and five normal individuals. Regional myocardial blood flow was calculated using the radioactivity in myocardial tissue measured by positron emission tomography and the radioactivity in arterial blood. Concerning the infarct related area, the exercise caused myocardial blood flow to decrease by 18.4% (P < 0.01) in the collateral-dependent areas (n = 8) of angiographically positive collaterals, and to increase by 14.4% (P = not significant) in the areas (n = 10) of negative collaterals. Four patients in whom the myocardial blood flow in all walls, including the normal areas, decreased with exercise were excluded from this evaluation. Myocardial blood flow in collateral-dependent infarct-related areas appeared to decrease transiently by low-grade exercise. Our results suggest that collaterals increase the incidence of exercise-induced ischemia, but may protect the infarct related but viable myocardium from necrosis.

Adult↗

Determination of regional myocardial blood flow with 13N-ammonia positron emission tomography during low-grade exercise for evaluating coronary artery stenosis.

We measured regional myocardial blood flow (RMBF) by positron emission tomography (PET) with 13N-ammonia at rest and during low-grade exercise using a bicycle ergometer fixed at 25 watts for 6.5 min. The ischemic area with severe coronary artery stenosis was evaluated in terms of quantitative RMBF. The study was performed in 46 subjects consisting of 19 patients with old myocardial infarction, 20 with effort angina pectoris, and 7 normal individuals. RMBF was calculated using the radioactivity in myocardial tissue measured by PET and the radioactivity in arterial blood. The PET data were compared with coronary arteriographic findings and ECG findings. When the analysis was restricted to the anterior wall of the myocardium, it was found that exercise caused RMBF to increase by 44.9% (n = 28) in normal area, to increase by 23.3% (n = 37) in severely stenotic area (stenosis > or = 90%), and to decrease by 17.4% (n = 20) in infarcted area. When we considered only the infarcted area of the entire heart, exercise caused RMBF to decrease by 26.6% (n = 30) in the area of angiographically positive collaterals, and to increase by 0.8% (n = 31) in the area of negative collaterals. Thus, we were able to quantitate the degree of ischemia in myocardium that was associated with severe coronary artery stenosis. By application of low-grade exercise, RMBF in normal myocardium increased, while RMBF in myocardium perfused by collaterals decreased.

Adult↗

[A case report of left ventricular-right atrial communication with tricuspid regurgitation due to infective endocarditis].

A case of 58-year-old man with a left ventricular-right atrial communication with tricuspid regurgitation due to infective endocarditis was reported. Surgical treatment was performed following intensive chemotherapy. The communication was found in the center of a vegetation on the septal leaflet. Closure of the communication and replacement of the tricuspid valve were done successfully. His postoperative course was uneventful.

Endocarditis, Bacterial↗

Detection of cholera toxin by a highly sensitive bead-enzyme linked immunosorbent assay.

A bead-enzyme linked immunosorbent assay (bead-ELISA) for detection and quantification of cholera toxin (CT) in broth cultures of Vibrio cholerae O1 has been developed. Under optimal buffer and pH conditions the bead-ELISA could consistently detect 40 pg/ml of CT. None of the ingredients of commonly used media for in vitro culture of V. cholerae O1 hindered the performance of the bead-ELISA. Evaluation of the sensitivity and specificity of the bead-ELISA against the commonly used reversed passive latex agglutination (RPLA) test for detection of CT was performed using a collection of 239 strains of V. cholerae O1 (including both biotypes and serotypes) which were examined by a gene probe encoding for the A1 subunit of CT. Although both the assays were highly specific, the bead-ELISA was more sensitive than the RPLA. Quantification of CT by the bead-ELISA revealed that the concentration of CT produced by the strains of V. cholerae O1 which were negative by the RPLA was lower than 1 ng/ml and therefore below the minimum detection ability of the RPLA. The bead-ELISA is a simple, specific and highly sensitive assay for routine detection of CT and is recommended for routine use in clinical microbiology laboratories.

Antigen-Antibody Reactions↗

[Long-term prognosis in patients with echocardiographic left ventricular dysfunction masquerading as dilated cardiomyopathy].

The long-term prognosis and prognostic factors were assessed in patients with left ventricular dilatation with impaired function secondary to idiopathic dilated cardiomyopathy (DCM) or to heart diseases of various pathogeneses masquerading as DCM (DCM-like). The echocardiographic criteria for DCM-like disease were 1) left ventricular end-diastolic dimension exceeding 60 mm and 2) fractional shortening less than 15%. Those who showed improvement in either of these 2 parameters within 3 months were excluded from this study. One hundred and fifty-eight of 35,250 serially examined patients fulfilled the definitions. The pathogeneses of diseases were valvular heart disease (VHD) in 30 patients, ischemic heart disease (IHD) in 37, alcoholic cardiomyopathy (AC) in 12, hypertensive heart disease (HHD) in 31 and DCM in 48. All of the survivors were followed for more than 24 months; an average of 40 months. During this period, there were a total of 75 deaths, 18 (27%) of whom were judged as sudden death. Five-year survival rates calculated using the Kaplan-Meier method in AC and HHD were 86% and 77%, respectively, which were significantly higher than those in DCM (48%; p < 0.05); whereas, patients with VHD and IHD had lower values (60% and 46%, respectively) which were nearly equal to those in DCM. Factors that contributed to the increase in total cardiac mortality were advanced age, higher NYHA functional class, larger cardiac size on chest radiograph and history of heavy alcohol intake. Each of these factors were closely related to the specific pathogeneses as follows: age to IHD, cardiac size to VHD, and NYHA functional class to DCM. Long-term prognosis of DCM-like heart diseases, especially those of IHD and VHD, seemed to be as bad as those of DCM.

Adult↗

Angioplasty of stenoses adjacent to aneurysmal coronary artery disease.

We examined the effectiveness and safety of performing angioplasty on stenoses adjacent to aneurysmal coronary artery disease. Out of 386 consecutive lesions (270 patients) on which we performed angioplasty, 13 lesions (13 patients) were within one balloon length of aneurysmal disease (group A) and 373 lesions (257 patients) were not (group NA). Angioplasty had previously been performed on 10 lesions (77%) in group A but only on 112 lesions (30%) in group NA (p less than 0.01). In group A the angioplasty success rate was 100% (13/13). The maximum inflation pressure was 6.5 +/- 1.1 atm, the frequency of inflation was 6.1 +/- 2.8, the average inflation duration was 60 +/- 0 sec, and the balloon/artery ratio was 1.20 +/- 0.11. There were no major complications. Restenosis occurred in only one lesion. There were no significant differences in the angioplasty results, procedures, complications and the incidence of restenosis between both groups. The ratio of the diameter of the aneurysmal disease to the mean diameter of the normal adjacent segments remained unchanged throughout the follow-up period. These data suggest that angioplasty may be an effective and safe treatment for those stenoses that are adjacent to aneurysmal coronary artery disease.

Angioplasty, Balloon, Coronary↗

[Medical treatment of type III dissecting aortic aneurysms: influence of the shape of the false lumen assessed by X-ray CT as a factor in the long-term prognosis].

The future needs of surgical repair for type III dissecting aneurysms among medically-treated patients were estimated according to the influence of the shapes of false lumina assessed by contrast-enhanced CT scans and by the level of blood pressure control at the time of discharge on the long-term prognoses. Thirty-six patients, 30 males and six females, whose mean age was 61 years, underwent enhanced CT scans at their discharge. Events, including deaths and dissection-related surgery were analyzed by a nonparametric actuarial method of Kaplan and Meier. The changes in CT findings were also studied in 33 patients who underwent follow-up CT scans within a mean interval of 3.5 years. 1. Systolic blood pressure was maintained below 140 mmHg (good control group) in 15 patients, and above 140 mmHg (poor control group) in 18 controls. There were no significant differences between the two groups for event-free survival rates. 2. The shapes of false lumina assessed by enhanced CT scans at the time of discharge were categorized in three types; 21 patients (group A) without false lumina of the aorta, or with a small crescentic false lumen in the thoracic aorta (type a), six patients (group B) with intimal flaps and two contrast-material-filled lumina in the thoracic aorta (type b), and nine patients (group C) with expanded false lumina or a false lumen whose margin was convex towards a true lumen in the thoracic aorta (type c).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

[A case of right-sided infective endocarditis in a drug addict].

A 49-year-old man was admitted to Mitsui Memorial Hospital because of fever of unknown origin. Since one year ago, he had often used intravenous narcotic drugs. Ten months before his admission, he had his first experience of fever and a chill. Four months later, he was admitted to a hospital under the diagnosis of pneumonia and he was treated successfully. After his discharge, he began to use drugs again, which resulted in the repetition of fever and chills during four months prior to his admission to our hospital. On admission, physical findings concerning the patient were unremarkable, except for mild hepatomegaly. ECG and chest X-ray were normal. Laboratory data revealed marked inflammatory changes and severe liver injury. Blood culture disclosed Campylobacter fetus and two dimensional echocardiography showed a large vegetation on the anterior tricuspid valve. He was diagnosed as isolated tricuspid infective endocarditis accompanied with acute hepatitis due to drug abuse. Moreover pulmonary perfusion scintigraphy showed decreased perfusion in the right lower lung field, which suggested that pneumonia of six months ago was due to septic pulmonary emboli from the infected tricuspid valve. The combined antibiotics therapy was successful. By the follow-up echocardiographic studies, the size of vegetation was observed to decrease progressively.

Campylobacter Infections↗

[Clinical significance of aortic ring dilatation and changes in aortic root configuration in the pathogenesis of non-rheumatic aortic regurgitation].

This study was undertaken to determine the etiology of non-rheumatic aortic regurgitation (AR) by two-dimensional echocardiography. Dimensions of the aortic root at the levels of the surgical aortic ring (ARDs), sinus of Valsalva (AOD), and anatomical aortic ring (ARD) were measured in 23 patients who underwent aortic valve replacement due to AR with idiopathic aortic root dilatation, in 15 hypertensive patients without AR and in 15 normal controls. The 23 patients with AR were classified as annuloaortic ectasia (AAE) (seven cases) and non-AAE (16 cases) groups. In the AAE group, the ascending aorta and aortic root were markedly dilated and had a pear-like configuration on aortography while the aorta had a normal configuration in the non-AAE group. ARDs was significantly larger in the non-AAE and AAE groups than in the hypertension and normal control groups. AOD and ARD were significantly larger in the hypertension and non-AAE groups than in the normal controls, and those in the AAE group were greater than those in any other group. The end-diastolic shape of the aortic valve in the long-axis view was "Y" shaped in the normal control and hypertension groups, "T" shaped in the non-AAE group, and the patients with AAE showed no cuspal coaptation. AR due to aortic ring dilatation, mainly reported by pathologists, were due to marked degree of ARD dilatation. However, our two-dimensional echocardiographic study showed that moderate dilatation of the entire aortic root in the non-AAE group seemed to be an important factor in the genesis of AR, even without dilatation of ARD.

Adult↗

[Dissecting aortic aneurysm of DeBakey type II diagnosed by color Doppler flow imaging and treated by a Bentall surgical procedure: a case report].

A 33-year-old man with known annuloaortic ectasia was admitted to the hospital because of chest pain. A dissecting aortic aneurysm was strongly suspected, but angiography was not performed because of his history of allergic reaction to iodine contrast material. Two-dimensional echocardiography demonstrated a markedly dilated basal aorta. The aortic wall immediately above the right sinus of Valsalva appeared to divide the aortic lumen into anterior and posterior channels. A defect in the intimal flap with a diameter of two cm was also detected six cm above the aortic ring. Color Doppler flow mapping showed blood flow passing through a probable entrance tear from the true lumen into the false lumen. Reentry could not be detected by Doppler imaging. All major aortic tributaries were presumed patent and supplied via the true lumen. The patient underwent successful emergency Bentall surgical procedure and recovered. It is emphasized that in some cases of DeBakey type I or II aortic dissection, color Doppler flow imaging is helpful for determining indications for emergency surgery.

Adult↗

Right ventricular filling detected by pulsed Doppler echocardiography during the convalescent stage of inferior wall acute myocardial infarction.

To evaluate right ventricular (RV) diastolic function in patients with inferior wall acute myocardial infarction (AMI), flow velocity patterns of the RV inflow tract were studied in patients with anterior AMI (n = 32), inferior AMI (n = 32) and angina pectoris without left ventricular asynergy (n = 10) using pulsed Doppler echocardiography. Doppler examinations were performed at least 4 weeks after the attack. Twenty-seven healthy persons served as control subjects. Three Doppler variables were measured at the RV inflow tract: the ratio of the late diastolic peak flow velocity due to atrial contraction to the rapid filling peak flow velocity in early diastole (A/E) and the acceleration time and deceleration time of the RV rapid filling wave. A/E in patients with inferior AMI (1.01 +/- 0.24, mean +/- standard deviation) was significantly greater than in those with anterior AMI (0.80 +/- 0.16, p less than 0.001) and angina pectoris (0.79 +/- 0.17, p less than 0.01) and in normal subjects (0.70 +/- 0.17, p less than 0.001). A/E in patients with inferior AMI correlated with the ratio of left ventricular to RV end-diastolic pressure (r = -0.60, p less than 0.05). A/E in inferior AMI with relatively high RV end-diastolic pressure (more than 8 mm Hg, n = 8) was significantly greater than that in those with normal pressure (8 mm Hg or less, n = 9). A/E in patients with proximal right coronary artery occlusion was significantly greater than that in those with distal occlusion.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

[Left ventricular diastolic properties before and after percutaneous transluminal coronary angioplasty evaluated by pulsed Doppler echocardiography].

Left ventricular diastolic properties were assessed by pulsed Doppler echocardiography before and after percutaneous transluminal coronary angioplasty (PTCA) in 30 patients. Four parameters were measured from records obtained by directing the ultrasonic beam from the cardiac apex to the base and by locating the sample volume at the mitral orifice: 1) the peak velocity of the rapid filling wave (R), 2) the peak velocity of the atrial contraction wave (A), 3) the acceleration half time (Ta: the time from half of the peak velocity to the peak velocity of the R, and 4) deceleration half time (Td: the time from the peak velocity to half of the peak velocity of the R). The ratio of the peak velocity of the atrial contraction to that of the rapid filling wave (A/R) was also calculated. 1. The R increased significantly after PTCA (p less than 0.01), whereas no significant change was observed in the A. 2. The A/R decreased significantly after PTCA (p less than 0.01). 3. PTCA did not influence significantly the acceleration half time or the deceleration half time. The augmented rapid filling observed after PTCA may reflect improvement of left ventricular myocardial relaxation. Our method sensitive in assessing diastolic properties is helpful for evaluating left ventricular function after PTCA.

Adult↗