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Biomedical subjects

T Takamoto

Publications and source records attributed to T Takamoto.

At least 73 records · Page 4Linked to original sources
PubMed1989

[Studies of cell-mediated immunity in mesangial proliferative glomerulonephritis--IgA nephropathy and non-IgA nephropathy].

In order to clarify the abnormalities of cell-mediated immunity in patients with mesangial proliferative glomerulonephritis [IgA nephropathy (IgA N) and Non-IgA nephropathy (Non-IgA N)], lymphocyte subsets were analysed by using monoclonal antibodies with flow cytometric two-color analysis and interleukin-2 (IL-2) production from lymphocytes of the patients was measured by ELISA system. A markedly decreased percentage (11.6 +/- 10.5%) of CD4+ 45R+ cells was found in the patients with IgA N when the results were compared with the normal controls (20 +/- 6%) (P less than 0.01). No difference was found between patients with IgA N and the controls as to the percentage of CD4+ 45R-, CD8+, 11+ and CD8+ 11- cells, respectively. Patients with Non-IgA N also showed a significantly decreased percentage of CD4+ 45R+ cells (10.9 +/- 6.5%), while CD8+ 11+ cells was parallely lowered (7.4 +/- 5%) in compared with the controls (10 +/- 4%). The percentage of HLA-DR positive cells was found to be increased in the patients with both IgA N and Non-IgA N, although the antigen bearing cells were reduced after stimulation with Concanavalin-A (Con-A). No difference in IL-2 production from lymphocyte of both patients groups and the controls cultured with Con-A was found. These results suggested that a deficiency of suppressor inducer T cells played a part of the pathogenesis of IgA N and Non-IgA N.

Adolescent↗
PubMed1988

Diagnostic accuracy of continuous wave Doppler echocardiography in severe aortic stenosis in the elderly.

Forty-four male patients (mean age 63.6 years) with aortic stenosis (AS) were evaluated by conventional hemodynamic methods and continuous wave (CW) Doppler echocardiography. The relationship between Doppler mean gradients and direct mean pressure gradients in all patients was significant, with an r value of 0.88. Sixteen of 17 patients with a mean Doppler gradient greater than or equal to 40 mmHg had severe AS (AVA less than or equal to 1.0 cm2). Twenty-seven patients had a Doppler gradient less than 40 mmHg, and 8 of these patients had severe AS (AVA less than or equal to 1.0 cm2). The sensitivity and specificity of a Doppler gradient greater than or equal to 40 mmHg in detecting severe AS were, therefore, 67% and 95%, respectively. Thirty-three percent (8/24) of patients with severe AS and low Doppler gradients (less than 40 mmHg) had evidence of poor left ventricular function, evidenced by a lower cardiac output, a higher heart rate and an abnormal PEP/LVET ratio compared to the other patients. Thus, the presence of a low stroke volume less than or equal to 60 ml/beat and PEP/LVET x HR greater than 26 is of value in identifying patients where the Doppler is likely to significantly underestimate the degree of aortic stenosis.

Adult↗
PubMed1988

DIDMOAD (diabetes insipidus, diabetes mellitus, optic atrophy and deafness) syndrome associated with myocardial disease.

A 30 year old man with DIDMOAD (diabetes insipidus, diabetes mellitus, optic atrophy and deafness) syndrome associated with myocardial disease is reported. Echocardiographic study revealed a marked symmetric left ventricular hypertrophy. Histology of the endomyocardial biopsy specimen from the right ventricle showed severe glycogen deposition in the myocytes. This case may indicate that DIDMOAD syndrome is a hereditary systemic disease affecting multiple organs, including the myocardium.

Adult↗
PubMed1988

Progression of aortic stenosis in the elderly detected by noninvasive methods.

One hundred eighty consecutive male patients, mean age of 64.6 years, who were referred to cardiac catheterization for the evaluation of aortic stenosis (AS), were studied using a noninvasive scoring system. The system is based upon 7 variables including: 1) LVH by ECG, 2) aortic valve calcium by chest x-ray, 3) loudness of A2, 4) Q to peak of murmur, 5) T time of the carotid pulse, 6) LV ejection time and 7) LVH by echocardiography. The scoring system has a range from 0 to 16, and a score greater than or equal to 5 indicates severe AS (valve area less than or equal to 1.0 cm2). Eighteen patients had hemodynamic studies on two occasions. In 3 years progression of stenosis was evident by an increase in the mean aortic valve gradient from 23 +/- 3.4 mmHg to 44 +/- 4.2 mmHg (p less than 0.005). The aortic valve area decreased from 1.4 +/- 0.1 cm2 to 0.76 +/- 0.07 cm2 (p less than 0.005). Noninvasive scores increased in these patients from 2.1 +/- 0.5 to 7.6 +/- 1.0 (p less than 0.005). Fifty-one patients had repeated noninvasive studies. Twenty-two patients, who had mild AS at the initial evaluation, attained a score of greater than or equal to 5 in 3 years, indicating probable progression to severe AS. The mean initial score was 2.3 +/- 0.4, and the score at the end of the mean follow-up period of 3 years was 8.0 +/- 0.6 (p less than 0.005).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1988

Behçet's disease associated with aortic and mitral regurgitation: report of two cases.

Two rare cases of complicating valvular lesions in Behçet's disease are reported. Case 1: A 45-year-old man with combined aortic and mitral regurgitation had perforation of both valves. Six months after aortic valve replacement (AVR) and mitral valvuloplasty, an aortic paravalvular leak developed again, and was treated by surgery using an artificial graft with a prosthetic aortic valve. Case 2: A 40-year-old man with congestive heart failure and inflammatory signs had aortic and mitral regurgitation. Although cardiac medications for heart failure and treatment with methylprednisolone were started, he eventually had successful aortic valve replacement. Valvular disease complicating Behçet's disease is rare; only 15 cases, including our two, have so far been reported. Its rarity is partly because Behçet's disease predominantly involves the venous system, not the arterial system.

Adult↗
PubMed1987

Optic disk cupping and pallor measurements of patients with a disk hemorrhage.

We evaluated whether the rate of occurrence of glaucomatous disk damage in eyes with an optic disk hemorrhage differed from the rate of occurrence in control eyes. We compared 24 patients with a disk hemorrhage to 24 control patients, who had been matched for diagnosis, disk appearance, and visual fields. Cup volume and cup-to-disk area ratio of the optic disk were measured using the stereophotogrammetric technique, and area of pallor was measured using computerized image analysis. We found that diabetes increased the probability that a patient would have a disk hemorrhage, and that a hemorrhage was associated with progression of glaucomatous disk changes in half of the cases during the mean 3.1-year follow-up period. However, the mean rate of glaucomatous disk damage in patients with a hemorrhage was not different from matched control patients. A disk hemorrhage is a sign of later disk damage, but it does not alter the rate of glaucomatous disk progression.

Eye Hemorrhage↗
PubMed1987

Dilated cardiomyopathy: clinical significance of possible related factors.

The present study investigates the clinical significance of several possible causative or conditioning factors which have been proposed to be involved in the pathogenesis of dilated cardiomyopathy (DCM). By reviewing the medical records of 68 patients with DCM, we found a definite, and suggestive family history in 16%, and 28%, respectively, and antecedent flu-like symptoms in 43%. A history of hypertension was observed in 35%, habitual alcoholism in 49% and diabetic pattern on glucose tolerance test in 37%. We then classified the study patients into three groups; familial, myocarditic and acquired groups. The familial group showed advanced myocardial damage with the poorest prognosis. Abnormal T-cell subsets in this group suggested that genetically determined abnormal immune response is involved in the development of DCM. In the myocarditic group, endomyocardial biopsy demonstrated mononuclear cell infiltration in 53% and the myocardial damage and prognosis were of intermediate severity. The acquired group showed significantly more frequent histories of hypertension, habitual alcoholism or diabetes than their age- and sex-matched controls, suggesting that they developed the disease in association with these factors. The severity of hemodynamic impairment and myocardial damage was the least extensive and prognosis was relatively favorable in this group. These different clinical features in the three groups may provide evidence that these factors actually contribute to the development of myocardial damage in DCM and that the condition is a clinical syndrome associated with heterogeneous etiologies or conditioning factors. Determination and management of these factors would be of practical value in treating patients with DCM that has no established therapy against underlying etiologies.

Adult↗
PubMed1987

Surface marker studies on activated peripheral blood lymphocytes in idiopathic dilated cardiomyopathy.

Expression of interleukin 2 (IL-2) receptor on peripheral blood lymphocytes after stimulation with concanavalin A (Con A) or anti-T3 monoclonal antibody was analyzed in patients with dilated cardiomyopathy (DCM) in order to clarify the abnormalities of lymphocyte activation mechanism in DCM. The expression of IL-2 receptor after the stimulation with either Con A or anti-T3 monoclonal antibody was found to be reduced in the patients with DCM when the results were compared with those of controls. A significant correlation was noticed between the expression of IL-2 receptor after Con A stimulation and T4+/T8+ cell ratio, and between the expression of IL-2 receptor after anti-T3 monoclonal antibody stimulation and the left ventricular end-diastolic pressure (LVEDP). The results suggest that there are abnormalities of lymphocyte activation in DCM and that the alteration may be associated with the cause or clinical conditions of DCM.

Adult↗
PubMed1987

Conduction disturbances associated with mitral anular calcification.

To investigate the apparent association of mitral anular calcification (MAC) and electrocardiographic abnormalities, the relation between the location of two-dimensional (2D) echoquantified MAC and conduction disturbances was studied in 140 patients with MAC (MAC group) and 135 age- and sex-matched patients without MAC (control group). The MAC group was subclassified regarding the site and severity of calcium in the mitral anulus. The site of MAC was defined as Type I of MAC near the conduction system and Type II of MAC away from the conduction system. The severity of MAC was graded on 2D echocardiography as mild (localized within 1 segment) and moderate to severe (more than 1 segment). Seven patients with MAC, and only one control subject, had pacemakers in place. Conduction disturbances were present in 44 (31%) of 140 patients with MAC and in 37 (27%) of the 135 control patients (no significant difference). But there were more conduction disturbances in the patients with Type 1 MAC (53%) than in those with Type II MAC (26%) (p less than 0.01). Specifically, complete left bundle branch block and intraventricular conduction delay were more prevalent when MAC was near the conduction system. Intraventricular conduction delay also was more prevalent in the patients with Type I MAC than in the control group (Type I: 12% vs control: 4%; p less than 0.05). These data suggest that moderate to severe degrees of MAC located near the conduction system are associated with conduction disturbances, especially intraventricular conduction delay.

Aged↗
PubMed1986

Definition of mixing rate of indicator by indicator dilution method: evaluation of relationship between mixing rate of indicator and cardiac output determination.

It is generally agreed that complete mixing of the indicator is one of the most important factors of the indicator dilution method, however, no clear definition of the mixing state has been established. We established a formula for the mixing rate of the indicator by the indicator dilution method, using the concept of entropy in the information theory, and compared the mixing rate of indocyanine green in one mixing chamber (left ventricle) with that in the two mixing chamber system (including the aortic system). The mixing rate of the indicator (M) is shown as M(%) = 100 H/Hcm = -100 (lk sigma ni = 1 Ci + log Ci + log k) (l & k: correction factors in each dye dilution curve, C: mean concentration of the indicator in the region). Left heart and aortic catheterizations by retrograde femoral and carotid artery approach were performed in five anesthetized dogs. Simultaneous dye dilution curves were recorded at the aortic root and at the bifurcation of the abdominal aorta, following the injection of indocyanine green (2.5 mg/1 ml of indocyanine green for each injection) by impulse into the left ventricle at the endsystole, triggered on the R wave of ECG, using the automatic injector devised by the authors. Twenty-five pairs of dye dilution curves were obtained by simultaneous recording in the aortic root and the abdominal aorta under several hemodynamic conditions, and the cardiac output, mean circulation time and the mixing rate of the indicator were determined.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1986

Lymphocyte subsets in patients with dilated cardiomyopathy and perimyocarditis.

Lymphocyte subsets were analyzed in patients with DCM, arrhythmias following influenza symptoms and acute perimyocarditis, respectively by an automated laser flow cytometry system with the use of monoclonal antibodies. A lower percentage of OKT8+ cells and a high OKT4/OKT8 ratio were found in the DCM and arrhythmias groups. No phenotypic abnormalities in the lymphocyte subsets were found in patients with acute perimyocarditis who were favorably progressing in clinical features. The results suggest that an immunological disturbance thought to play a part of the pathogenesis of DCM or heart failure may cause the abnormality of lymphocyte subsets.

Adult↗
PubMed1985

Measurements of reversibility of optic disc cupping and pallor in ocular hypertension and glaucoma.

Four cases are presented of young and elderly glaucoma patients who had both surgical and medical therapy and showed reversal of cupping and pallor of the optic disc. The cupping was measured by photogrammetry and the pallor by computerized image analysis from photographs of the optic disc. Two patients showed regression of visual field loss. The optic disc and visual field changes corresponded to the changes in ocular pressures, generally showing worsening with an increase in ocular pressure. With a decrease in ocular pressure there was regression of visual field loss and a decrease in cupping; pallor did not decrease consistently. The changes in cupping and pallor in some patients followed similar courses but in others behaved in an independent manner. It is proposed that these new sensitive and reproducible techniques for measuring changes in the optic disc may allow the detection of disc changes early in the disease, prior to visual field loss. If treatment is begun at this time, reversal of optic disc changes may occur.

Aged↗
PubMed1985

Comparative recognition of left ventricular thrombi by echocardiography and cineangiography.

Studies performed in 47 patients, 11 of whom underwent surgery for aneurysmectomy and 36 of whom underwent cardiac transplantation, were reviewed to assess the diagnostic accuracies of cross sectional echocardiography and cineangiography in detecting left ventricular mural thrombi and the effect of anticoagulation treatment on the incidence of such thrombi. Cross sectional echocardiography in 37 patients and cineangiography in 26 (16 patients were examined by both methods) were analysed independently by sets of two observers experienced in the respective methods. All four observers were blinded to the pathological or surgical findings regarding mural thrombus. Mural thrombus was confirmed by pathological investigation in 14 of 47 (30%) cases; 11 of these 14 patients had intra-aneurysmal thrombi. The negative predictive value was quite good for both methods, but cross sectional echocardiography had a superior positive predictive value. This was due both to detailed soft tissue resolution by cross sectional echocardiography and to overdetection of mural thrombi by cineangiography in cases of aneurysms without mural thrombi. Mural thrombi were present in three of 20 patients with preceding anticoagulation and in 10 of 19 patients without anticoagulation. The results emphasise that cross sectional echocardiography is more reliable than cineangiography in recognising thrombi.

Adult↗
PubMed1985

Ultrasonic tissue characterization: detection of acute myocardial ischemia in dogs.

Ultrasonic tissue characterization is a new area of investigation in the field of cardiac ultrasound. The amplitude and frequency of the ultrasound signal are normally altered as the signal penetrates through tissue. It is assumed that the amplitude distribution and frequency shift of diseased or edematous tissue are different than those of normal tissue. A statistical approach to the analysis of the unprocessed radiofrequency signal in the amplitude domain was used to study the effect of acute myocardial ischemia on the parameter mean amplitude/standard deviation of the amplitude (MSR). Ten dogs were anesthetized and underwent left lateral thoracotomy. Baseline mean MSR from the interventricular septum was 1.99 +/- 0.05, but increased by 30 min after coronary artery occlusion and started to plateau at 1 hr (mean 2.24 +/- 0.06). Reproducibility in noninfarcted myocardium (left ventricular inferoposterior wall) was good, with a mean MSR of 2.00 +/- 0.05 at baseline and 1.98 +/- 0.04 3 to 4 hr later. There was no difference in mean MSR when data were obtained through chest wall and when they were obtained directly from the surface of the heart. We conclude that statistical analysis in the amplitude domain of the unprocessed radiofrequency signal can detect acute myocardial ischemia within 30 min after coronary artery occlusion, provides reproducible measurements, and is unaffected by chest wall filtering.

Animals↗
PubMed1985

Reproducibility of photogrammetric optic disc cup measurements.

To detect early glaucoma-associated changes in the optic disc cup, the authors analyzed reproducibility of optic disc cup measurements by photogrammetry of three age-matched groups: 10 normal, 10 ocular hypertensive, and 10 glaucomatous subjects. For each eye, three simultaneous stereophotographs were taken on the same day and one measurement was made for each stereophotograph. In order to reduce the effects of refractive error of the eye and photographic magnification, the authors computed cup parameters as relative measurements, ie, a ratio to the optic disc area. The median coefficients of variation for glaucomatous eyes were 4.5% for cup volume/disc area, 6.1% for cup depth/disc area, and 4.7% for cup area/disc area. Coefficients of variation of normal and ocular hypertensive subjects were slightly larger than those of glaucomatous subjects. Coefficients of variation generally were larger for quadrants than for total disc area. These findings suggest that the photogrammetric technique is highly reproducible and sensitive and could be a valuable quantitative technique for the clinical study of glaucoma.

Glaucoma, Open-Angle↗