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Biomedical subjects

M Takamiya

Publications and source records attributed to M Takamiya.

At least 145 records · Page 8Linked to original sources
PubMed1988

[Comparisons of images simultaneously documented by digital subtraction coronary arteriography and cine coronary arteriography].

Using an angiography apparatus capable of simultaneously processing digital subtraction angiograms and cine angiograms, the diagnostic capabilities of both methods for the coronary arteries (DSCAG and Cine-CAG) were compared. 1. Twenty stenotic lesions of the coronary arteries of 11 patients were evaluated using both modalities. The severity of stenosis using DSCAG with a 512 x 512 x 8 bit matrix was semiautomatically measured on the cathode ray tube (CRT) based on enlarged images on the screen of a Vanguard cine projector which were of the same size as those of or 10 times larger than images of Cine-CAG. The negative and positive hard copies of DSCAG images were also compared with those of Cine-CAG. The correlation coefficients of the severity of stenosis by DSCAG and Cine-CAG were as follows: (1) the same size DSCAG images on CRT to Cine-CAG, 0.95, (2) 10 times enlarged DSCAG images on CRT to Cine-CAG, 0.96, and (3) the same size DSCAG images on negative and positive hard copies to Cine-CAG, 0.97. The semiautomatically measured values of 10 times enlarged DSCAG images on CRT and the manually measured values of the same size negative and positive DSCAG images in hard copy closely correlated with the values measured using Cine-CAG. 2. When the liver was superimposed in the long-axis projection, the diagnostic capabilities of DSCAG and Cine-CAG were compared. The materials included 10 left coronary arteriograms and 11 right coronary arteriograms. Diagnostically, DSCAG was more useful than Cine-CAG in the long-axis projection.

Angiography, Digital Subtraction↗
PubMed1987

Characterization of picomolar affinity binding sites for [125I]-human calcitonin gene-related peptide in rat brain and heart.

We have characterized picomolar affinity binding sites for human calcitonin gene-related peptide (CGRP) in rat brain and heart (atria and ventricle) membranes. By saturation analysis, apparent dissociation constant (KD) values of high affinity sites for [125I]-human CGRP are 9 approximately 15 pM (brain), 34 pM (ventricle) and 85 pM (atria). Low affinity sites with KD values of about 50 nM are found in rat brain and ventricle, but not in atria. Human and rat CGRP potently inhibited [125I]-human CGRP binding to these high affinity sites with apparent inhibition constant (Ki) values comparable to their KD values. Salmon calcitonin marginally inhibited these binding with Ki values between 0.1 microM and 1 microM. Extremely potent cardiovascular and gastrointestinal actions of CGRP might be mediated through CGRP binding sites with picomolar affinity which are similar to those we characterized in this study.

Animals↗
PubMed1987

Magnetic resonance imaging of human cerebral infarction: enhancement with Gd-DTPA.

Five patients (1 female and 4 males) with cerebral infarction of 4 h to 27 months duration were studied 9 times with magnetic resonance (MR) using Gd-DTPA. Spin-echo (SE) MR images (MRI) were obtained before and after the administration of Gd-DTPA, and correlative CT scans were performed on the same day. In 2 cases, 4 h and 27 months after the ictus, there was no enhancement with Gd-DTPA. There was faint enhancement in 2 cases with cerebral infarction of about 24 h duration and obvious enhancement in all cases in the subacute stage. Compared with enhanced CT, MR using Gd-DTPA demonstrated more obvious enhancement of infarcted areas. MR enhancement using Gd-DTPA showed a gradual increase and the accumulated Gd-DTPA in infarcted areas slowly diffused to the periphery. MR enhancement with Gd-DTPA is similar to that of enhanced CT, but may be more sensitive in the detection of blood brain barrier breakdown.

Adult↗
PubMed1987

Cor pulmonale due to embolization of metastatic chondrosarcoma.

A 25-year-old woman with acute dyspnea was found to have nodular shadows in a chest X-ray film. Multiple defects in a perfusion scan indicated pulmonary embolization. The cause of acute cor pulmonale was extensive metastatic embolization from chondrosarcoma of the calf. Embolization by metastasis as a rare occurrence resulting in acute cor pulmonale should be considered in patients with a malignant tumor.

Adult↗
PubMed1987

Follow-up study of coronary artery lesions due to Kawasaki disease by serial selective coronary arteriography in 200 patients.

In a follow-up study of coronary artery lesions (CAL) due to Kawasaki disease, 200 patients were examined by serial coronary arteriography 1 year after first detection of the condition. On comparing the findings of the two coronary angiographic studies, a worsening of stenotic lesions was detected in 30 patients (15%; 40 of 139 stenotic lesions, 29%), while improvement of stenotic lesions was seen in 24 patients (12%; 40 lesions, 29%). Relating these changes in CAL to the interval from the onset of disease to the first coronary arteriography showed the rate of increased or new stenotic lesions (37%) to be higher in the late group, in which the first study was performed 5 months after the onset of the disease, than in the early group (21%), in which the study was done within 4 months from the disease onset. The frequency of decrease in aneurysm size was higher in the early group (70%) than in the late group (19%).

Angiography↗
PubMed1987

Variation in coronary arterial dimension (distensible abnormality) after disappearing aneurysm in Kawasaki disease.

Distensible abnormality of the coronary arteries was evaluated in children with Kawasaki disease. The internal diameter of the left coronary artery (diameter) was measured by cineangiography. Among 38 children with Kawasaki disease, 17 developed aneurysms which later disappeared (disappearance group) and 21 had no aneurysm (no aneurysm group). Eleven children had no history of the disease (control group). The maximal diameter was recognized in systole and the minimal diameter in diastole. The mean distensibility index ([maximal diameter-minimal diameter]/minimal diameter) was 5.7% in the disappearance group, 7.9% in the no aneurysm group, and 11.3% in the control group. There were significant differences among the three groups. We demonstrated that distensibility in the coronary arteries in children with Kawasaki disease decreased and that in the no aneurysm group distensibility ranged between the values in the control group and those in the disappearance group.

Adolescent↗
PubMed1987

31P in-vivo spectroscopic study by high-field whole-body MR system--an application to a case with arteriosclerosis obliterans.

31P in-vivo spectroscopy was performed by a 1.5-tesla whole-body MR system. The 31P spectrum for the calf muscle in a patient with arteriosclerosis obliterans having intermittent claudication was obtained every two minutes. When the spectrum after the workload was compared with that at rest, an increase in inorganic phosphate (Pi) and a decrease in phosphocreatine (PCr) were observed, resulting in a strong decrease in the PCr/Pi ratio. This method can measure the ischemic and recovery stages of energy metabolism in skeletal muscle noninvasively and continuously in addition to magnetic resonance imaging.

Aged↗
PubMed1987

[Myocardial perfusion detected using digital subtraction angiography as compared with X-ray CT and Tl-201 myocardial imaging].

Forty-two patients who underwent aorto-coronary bypass surgery were examined with intra-aortic digital subtraction angiography (IADSA) to detect abnormalities of myocardial blood perfusion. Tl-201 myocardial imaging and cardiac X-ray CT were performed nearly simultaneously about one month postoperatively. Cardiac imaging using IADSA was performed at a rate of 30 frames/sec with matrix size of 512 x 256. Time density curves of each pixel in the region of the myocardium of the left ventricle were post-processed to obtain functional images. The maximal concentration (Cmax), integration of the time-density curve (Cinteg), mean transit time (MTT), Cmax/MTT and Cinteg/MTT were computed for each pixel. Cmax and Cinteg are parameters related to the volume of the coronary vascular bed. Cmax/MTT and Cinteg/MTT are parameters related to the regional myocardial blood flow. These functional images showed hypoperfusion areas in 35 of 37 ischemic segments confirmed by wall motion in digital subtraction left ventriculography, Tl-201 myocardial imaging and ECG. Normal perfusion areas of the functional images were observed in 18 of 54 infarcted segments. These results show the complexities of myocardial perfusion in old myocardial infarction.

Coronary Angiography↗
PubMed1987

[Pre- and post-operative right ventricular functions in valvular heart diseases: the significance of noninvasive assessment].

This investigation was undertaken to evaluate right ventricular function in valvular heart diseases by calculating right ventricular ejection fraction (RVEF) from first-pass radionuclide angiography (RNA). One hundred cases of valvular heart disease were examined by RNA, 93 of whom underwent cardiac catheterization and contrast left ventriculography, preoperatively. Fifty of the 100 cases were examined by RNA; 18 by cardiac catheterization post-operatively. The results were as follows: 1. In 49 cases of mitral valve disease, there was a correlation (r = -0.75) between pulmonary artery mean pressure (PAm) and RVEF. This suggested that afterload of left atrial pressure elevation induced a decrease in RVEF. 2. Although PAm did not increase so much in aortic valve disease, RVEF decreased in some cases, especially in those having massive aortic stenosis or regurgitation. In 22 cases of aortic regurgitation which had normal PAm and a left ventricular-aortic systolic pressure gradient less than 50 mmHg, there was a correlation (r = -0.69) between the RVEF and the left ventricular end-diastolic volume index (LVEDVI). 3. Although post-operative RVEF did not improve significantly in mitral valve disease, it increased significantly in the early post-operative period in aortic valve disease. Also, the increase in RVEF and the decrease in LVEDVI seemed to correlate closely in aortic valve disease. It was speculated that pre-operative decrease of RVEF is derived from a deformity of the RV caused by pressure from the enlarged or thickened LV, and that post-operative increase of RVEF is dependent upon a decrease of LV size and volume.

Erythrocytes↗