Biomedical subjects
Publications and source records attributed to T Takamoto.
A 56-year-old female presented with a rare intraosseous meningioma associated with an unusual dural defect caused by invasion of the tumor. The underlying dura mater is normal or thickened in most cases of intraosseous meningiomas. Most intraosseous meningiomas are benign histologically, but they should be extirpated before invasion into the subdural space occurs.
In Japan, clinical and basic investigations of Albunex were started from 1989, and was firstly approved by the government as a commercially available contrast agent for the cardiovascular disorders. Although it has recently evacuated from the market, its acoustic properties proven by the many investigators were valuable for preparation of the second generation of contrast agents. Therefore, we summarized our data of the ultrasonic properties of Albunex both in vitro and experimental dog studies using RF signals. In conclusion, Albunex was a extremely sensitive blood flow tracer in evaluating intracardiac blood flow as well as intramyocardial perfusion.
The contrast echocardiography used to be applied for the diagnosis of congenital heart diseases, analysis of right side heart hemodynamics, and the evaluation of peripheral blood flow profiles. Recently, myocardial contrast echocardiography is evoked for estimating regional coronary blood flow as a parallel procedure of interventional therapy for ischemic patients. Advanced technology such as harmonic imaging, rf signal processing and digital storage of the data are extremely supportive for the quantitative evaluation of myocardial blood flow. In addition, new contrast agents which enable interpretation of myocardial contrast could be administered by peripheral injection.
Mitral valve aneurysm is defined as a localized protrusion of the valve with a different radius from that of the remaining portion of the valve. The medical records and pathological findings of seven patients with mitral valve aneurysm [aged 48-69 years (mean 64), 4 males] and the pathological findings of other 29 Japanese cases were reviewed. All seven patients were diagnosed pathologically as infective endocarditis, but two patients had no documentation of clinical symptoms suggestive of infective endocarditis (latent infective endocarditis). The underlying lesion of the heart was aortic valve disease and/or fibrosal degeneration of the mitral valve. Only 29 of 36 Japanese case reports stated a precise description of the valve pathology. Of these 29 cases, 23 were associated with infective endocarditis, two with rheumatic valvular disease with fusion and/or shrinkage of the chordae tendineae, three with mitral valve prolapse or myxomatous degeneration of the mitral valve, and one with aortitis syndrome. Neovascularization was described in eight cases. Neovascularization with thick wall should be considered as post-inflammatory vascularization. This review indicates that patients with latent infective endocarditis and mitral valve aneurysm should be considered as potential candidates for valve surgery.
A vigorous production of human T lymphotropic virus type I (HTLV-I)-infected CD4+ T cells is closely associated with the development of adult T cell leukemia (ATL) and neurological disease. However, the immunological mechanisms leading to generation of the HTLV-I-infected cells are not fully clarified. The modulation of CD80 and CD86 expression on the HTLV-I-infected cells and its physiological role in the interaction of infected CD4+ T cells with uninfected CD4+ T cells was examined. The HTLV-I-infected CD4+ T cell lines established from ATL patients and normal donors by infecting their CD4+ T cells with the virus expressed CD80, CD86, and HLA-DR, and induced a proliferation of autologous and allogenic CD4+ T cells. While the CD4+ T cells stimulated with the autologous HTLV-I-infected cells for 7 days expressed CD80 and CD86 but not HTLV-I gene products, they expressed HTLV-I gag antigen after 4 weeks. The interaction of HTLV-I-infected and -uninfected CD4+ T cells was profoundly suppressed by a combination of CD80 and CD86 monoclonal antibodies. These results suggest that the induction of CD80 and CD86 on HTLV-I-infected CD4+ T cells participates actively in the generation of the virus-infected progenitor cells.
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PURPOSE: To describe a method which provides quantitative measurements of the surface area of pallor in each quadrant of the three-dimensional optic cup, using photogrammetric measurements from simultaneous stereophotographs and computerized image analysis. METHODS: Simultaneous stereophotographs of one normal subject and two subjects with primary open angle glaucoma were digitized and analyzed for depth measurements. The boundaries of the optic disc, optic cup and region of pallor were identified. Pallor/disc and pallor/cup ratios were subsequently calculated for the superior, temporal, inferior and nasal walls. RESULTS: A digitized photograph and a Laplacian-filtered image were obtained for each eye to be studied. After processing each stereo pair through a similarity sequential detection-based algorithm, depth measurements are represented as a grey scale image, a contour plot, and a wire mesh, with the boundaries of the optic disc, optic cup and pallor superimposed. Ratios are given of the surface area of pallor to the surface area of the disc and the surface area of pallor to the surface area of the cup, by quadrant. CONCLUSIONS: Determination of surface area of pallor to cup may be useful in detecting early visual field loss in glaucoma and neurological disease.
To assess the relationship between coronary artery calcification and the late success rate of percutaneous transluminal coronary angioplasty (PTCA), we performed electron beam computed tomography (EBCT) in 22 patients with ischemic heart disease who underwent PTCA. The calcification score in each coronary artery vessel was estimated and compared with the occurrence of restenosis at 3 months after PTCA. Angioplasty had been performed in 28 sites in 22 patients, and 12 sites exhibited restenosis. The mean calcium score in the unsuccessful PTCA vessels was significantly higher than in successful sites (228 vs 92). The overall late success rate of PTCA with moderate to severe calcification was extremely low at 29%. Coronary segments with diffuse and extensive calcification were not optimal target lesions for PTCA. Prediction of the late success rate after PTCA may be possible by prior evaluation of coronary artery calcification utilizing EBCT.
To investigate the left ventricular hypertrophic patterns and wall motion dynamics in hypertrophic cardiomyopathy, 51 patients were studied using electron beam computed tomography. The subject consisted of 26 asymmetrical hypertrophy, 9 diffuse hypertrophy, 14 apical hypertrophy and 2 papillary muscle hypertrophy. Concerning the wall motion dynamics in hypertrophic wall, 7 demonstrated homogeneous wall thickening involving the non-hypertrophic wall, 36 showed decrease wall thickening, 6 showed normal wall thickening, and 2 cases of papillary muscle hypertrophy had increased wall thickening in the apical wall. The percent wall thickening in hypertrophic wall was significantly reduced in relation to the increase of wall thickness; 14 +/- 8% in the wall over 20 mm, 23 +/- 12% in 16-9 mm and 56 +/- 36% in 13-15 mm. The reduced wall motion dynamics in hypertrophic wall were clearly observed by electron beam computed tomography.
A 43-year-old female, admitted because of acute infero-posterior myocardial infarction, showed angiographic findings of 100% occlusion of left circumflex artery. Echocardiographic findings showed inferior hypokinesis, while a large left intraatrial tumor was also observed. The coronary angiography on the 17th hospital day showed complete reperfusion of the culprit lesion without stenosis. On the 21st hospital day, the removal operation of the tumor was performed. Pathological findings showed typical cardiac myxoma, and the etiology of the occlusion at the culprit vessel was presumed to be closely related to the existence of the left atrial tumor.
A 79-year-old male, admitted because of severe dyspnea on exertion, showed echocardiographic findings of a large tumor in the dilated right ventricle. The right ventricular outflow tract was nearly occluded by the tumor mass, and the mass was attached to the interventricular septum by a pedicle. The tumor removal operation was successful. The size of the tumor was 40 mm x 90 mm, and the weight 70 g. Microscopic findings showed typical myxomatous tissue with high cellularity, and no malignancy was observed. This is the oldest reported patient with right ventricular myxoma which was cured by operation.
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PURPOSE: The purpose of this study was to determine whether timolol drops compared to placebo drops had a significant effect on optic disc cupping and pallor in ocular hypertensives. METHODS: Thirty-seven ocular hypertensives were randomly assigned to placebo or 0.5% timolol drops to both eyes in a double masked clinical trial. Measurements of ocular pressure and photographs of the optic disc for cupping by photogrammetry and pallor by computerized image analysis were made at about 3 month intervals, for 18 to 24 months of follow-up. RESULTS: None of the subjects developed visual field loss when tested with the Goldmann perimeter by kinetic and static means at six month intervals. Subjects treated with timolol developed a significant decrease in ocular pressure and a significant decrease in optic disc cupping with a smaller decrease in pallor compared to subject treated with placebo. Multivariate analyses indicated that the decrease of optic disc cupping and pallor was not associated with the ocular pressure on treatment or the decrease in ocular pressure during the trial. CONCLUSION: Timolol treatment was associated with a decrease in optic disc cupping and pallor. The effect of timolol appears to be related to mechanisms other than the decrease in ocular pressure.
PURPOSE: The purpose of this study was to determine whether timolol drops compared to placebo drops had a significant effect on retinal nerve fiber layer thickness in ocular hypertensives. METHODS: Thirty-seven ocular hypertensives were randomly assigned to receive placebo or 0.5% timolol drops to both eyes for 18 to 24 months in a double masked clinical trial. Measurements of ocular pressure and photographs of retinal nerve fiber layer using stereophotogrammetric techniques were made at about 3 month intervals for 18 to 24 months of follow-up. RESULTS: None of the subjects developed visual field loss when tested with the Goldmann perimeter by kinetic and static means at six month intervals. Subjects treated with timolol had a significant decrease in ocular pressure and developed a significant increase in retinal nerve fiber layer thickness compared to subjects treated with placebo. Multivariate analyses indicated that the increase of retinal nerve layer thickness was not associated either with the ocular pressure on treatment or the decrease in ocular pressure on treatment. CONCLUSION: Timolol treatment was associated with an increase of retinal nerve fiber thickness. The effect of timolol appears to be related to mechanisms other than the decrease in ocular pressure.
PURPOSE: The purpose of this study was to determine whether timolol drops compared to placebo drops had a significant effect on retinal vessel width in ocular hypertensives. METHODS: Thirty-seven ocular hypertensives were randomly assigned to receive placebo or 0.5% timolol drops to both eyes for 18 to 24 months in a double masked clinical trial. Measurements of ocular pressure and retinal vessel width by computerized image analysis from fundus photographs were made at about 3 month intervals for 18 to 24 months of follow-up. RESULTS: None of the subjects developed visual field loss when tested with the Goldmann perimeter by kinetic and static means at six month intervals. Subjects treated with the placebo showed no change in ocular pressure and a significant decrease in retinal vessel width over time especially in the right eye. Subjects treated with timolol had an increase in retinal vessel width compared to the placebo group significant especially for the superior temporal vein. Multivariate analyses indicated that the increase of retinal vessel width was not associated mainly with the ocular pressure on treatment or decrease in ocular pressure on treatment. CONCLUSION: Timolol treatment was associated with an increase of retinal vessel width. The effect of timolol appears to be related primarily to mechanisms other than the decrease in ocular pressure.
AIMS: The laser Doppler technique was used to compare the capillary blood speed measured at localised sites of the optic nerve head in stable, untreated ocular hypertensive patients with that measured in healthy normal subjects. The stereophotogrammetric technique was also used to measure the retinal nerve fibre layer thickness at the disc margin in the eyes of the patients. METHODS: Doppler broadening measurements were made at superior and inferior temporal disc sites in 18 eyes of 10 ocular hypertensive patients and in 12 eyes of seven age and sex-matched normal subjects. RESULTS: On average, Doppler broadening and, hence, capillary blood speed were significantly higher (p = 0.018) in the patients than in the normal subjects. The largest values of Doppler broadening in the patients were measured at sites adjacent to the thinnest retinal nerve fibre layer. Linear regression analysis showed a significant inverse relation (p = 0.0004) between Doppler broadening and nerve fibre layer thickness in left eyes, and a nearly significant relation (p = 0.06) in right eyes. At temporal sites of the optic nerve head there is a compensatory relation between a thinning nerve fibre layer and a locally increasing blood supply to the optic nerve head. CONCLUSION: Together with previous observations of fluorescein filling defects in similar patients, these results indicate that there is spatial heterogeneity of blood flow in the optic nerve head in stable, untreated ocular hypertensive patients.
To evaluate postprandial hemodynamic changes, Doppler measurements of stroke volume before and after lunch were carried out in 10 healthy volunteers (all men) with a mean age of 28 years. The stroke volume was calculated as the product of echocardiographically determined aortic valve area and the ejection flow velocity integral obtained by continuous wave Doppler. The stroke volume before lunch was 61 +/- 7 ml, which was increased to 72 +/- 8 ml 1 hour after lunch and remained constant for the next 4 hours. Five hours later the stroke volume was then decreased to the baseline. M-mode echocardiography revealed an increase in left ventricular end-diastolic dimension and ejection fraction after lunch. Another 9 healthy subjects (6 women and 3 men) with a mean age of 52 years received a 75 g oral glucose tolerance test (OGTT) instead of a common lunch; stroke volumes were not altered in association with the elevation of plasma glucose level. In conclusion, ingestion of food had a positive inotropic effect and caused circulating blood volume expansion with an increment of heart rate. Therefore, Doppler studies that are not standardized for patients' mealtimes may affect the validity of data in serial studies of left ventricular function.
Laser scanning tomography (LST) and computed stereophotogrammetry (CSP) are sophisticated diagnostic tools for the three-dimensional analysis of optic nerve head topography. The two methods are based on different physical principles. To compare the information about the shape of the cup of an optic nerve head obtained by LST and CSP, we evaluated the volume profile (VP; i.e., the cross-sectional area of the cup from top to bottom) in 36 discs of 36 patients (20 control group discs C, 16 glaucoma discs G). The Spearman correlation coefficient between the photogrammetric and the laser scanning VP-slope measurements was rs = 0.931; P < 0.001 (rs = 0.935 G, P < 0.001; rs = 0.910 C, P < 0.001). The results suggest that confocal laser scanning provides readings of the shape of the optic disc cup that are similar to the measurements of computed stereophotogrammetry.