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Biomedical subjects

J Yamazaki

Publications and source records attributed to J Yamazaki.

At least 127 records · Page 7Linked to original sources

[Evaluation of left atrial function by 99mTc gated blood pool scan].

99mTc gated blood pool scans were studied to assess the left atrial function. Relationship between filling time and rapid emptying time was y = 0.695 x + 109 (r = 0.761, p less than 0.05, n = 14) in LAO and LPO projections. On the other hand, relationship between slow filling and rapid emptying time was good closely (y = 0.846 x + 16.9 (p less than 0.01, r = 0.975, n = 8] in standard and retrograde acquisition. To assess the left atrial function by standard acquisition in LAO projection should be available for clinical use.

Aged↗

[The evaluation of left ventricular eccentric hypertrophy by 201Tl-myocardial scintigraphy].

In order to elucidate the mechanism of left ventricular eccentric hypertrophy in conditions of volume overload, Tl-201 myocardial scintigraphy was performed patients with aortic valve regurgitation and mitral valve regurgitation. There was a good relationship between the severity of Tl-defects, as determined by Tl-201 myocardial scintigraphy, and the changes in the T wave on the ECG on the one hand and the NYHA functional classification of heart diseases. In 17 of 18 patients where LVDd increased with increasing severity of Tl-defects and the defects were moderate to severe, LVDd was 65 mm or larger. There was a significant negative correlation between the washout rate for the whole circumference of the left ventricle, as determined by exercise Tl-201 SPECT, and LVDd (r = -0.603, p less than 0.01). The phenomenon of redistribution as determined by exercise Tl-201 myocardial scintigraphy was observed relatively early. Our results suggest that mechanical volume overload and ischemic changes are involved in left ventricular wall damage in left ventricular eccentric hypertrophy. For patients with moderate to severe Tl-defects valve replacement is indicated, no matter whether they may have heart failure or arrhythmia.

Adult↗

[Application of straight chain fatty acid analog IPPA [omega-(p-iodophenyl)-pentadecanoic acid] for myocardial imaging--using acute myocardial infarction model].

Application for myocardial imaging and fundamental experiments were studied using straight chain fatty acid analog IPPA [omega-(p-iodophenyl)-pentadecanoic acid]. Biodistribution of IPPA in rabbits (n = 6) shows the accumulation in liver was maintained 81.0% at 30 minutes, while the accumulations of heart, lungs and kidneys were 30.0%, 10.0% and 15.0% respectively. Especially the accumulation of heart decreased rapidly from 48.0% at 3 minutes to 30.0% at 30 minutes, reflecting the effect of beta oxidation. On the other hand, in the acute myocardial infarction mode (n = 6), with occlusion in left anterior descending coronary artery, all 6 cases showed defect images at the corresponding areas after injection of 3 mCi of IPPA. Myocardial imaging with IPPA should be useful not only for myocardial metabolic diseases (cardiomyopathy etc.) but also for ischemic heart disease.

Animals↗

[A case of metastatic lung tumor mimicking left atrial myxoma by echocardiography].

We report a case of lung metastatic tumor originated from submandibular osteosarcoma, which shows rare advancement and findings. This lung metastatic tumor advanced from left lower lung to left atrium through the left lower pulmonary vein, which penetrated to the left ventricle in the diastolic phase mimicking left atrial myxoma. 67Ga-citrate images showed that hot accumulation were recognized behind the heart in planar image and clear advancement from the lung to the heart in the SPECT image. 67Ga-citrate SPECT image should be available for cardiac tumors.

Adult↗

[The evaluation of the therapeutic effect on acute myocardial infarction by radioisotope method--assessment of the intravenous injection of urokinase and comparison with the results of PTCR + PTCA].

The therapeutic effect of intravenous injection of Urokinase (UK method) on acute myocardial infarction (AMI) was studied and compared with the results of the therapeutic effect of PTCR + PTCA. The subjects comprise 108 cases with AMI, and a radioisotope examination was performed in the acute stage to calculate LVEF and Tl-defect ratio (Tl-DR). Measured by the UK method, Tl-DR in the group given 1.2 X 10(6) units of UK was 1.63 +/- 0.8, which was lower than the 2.4 +/- 1.33 for the group given 9.6 X 10(5) unit of UK, whereas a favorable therapeutic effect was obtained in both groups compared to 3.5 +/- 2.5 in the control group. In the group given UK within 6 hours after the onset of AMI, favorable results were obtained for LVEF (44.5 +/- 11.2%) and Tl-DR (1.68 +/- 0.82). The UK group showed as better results as the PTCR + PTCA group for LVEF (42.3 +/- 11.3 vs. 38.1 +/- 7.4) and Tl-DR (2.10 +/- 1.19 vs. 2.09 +/- 0.62). In both the UK and PTCR + PTCA groups, Tl-DR was well maintained despite an increase in the peak CPK and a decrease in LVEF, and, therefore, the conservation of stunned myocardium in the acute stage was suggested. From the above, it was concluded that the UK method is useful for treating AMI.

Aged↗

Malignant schwannoma of the heart.

Primary cardiac tumor is an extremely rare disease entity. Only three cases of primary malignant cardiac schwannoma, the subject of this report, have been recorded in Japan. Recently, we encountered a case of malignant schwannoma in which retention of pericardial effusion was the first clinical finding. This case was a 30-year-old female, who had dyspnea at work, general fatigue, and fever. Striking cardiac expansion was seen, with a cardiothoracic ratio (CTR) of 69% on chest x-ray. Two-dimensional echocardiograms showed a large volume of pericardial effusion between the side wall of the left ventricle and the epicardium, and the presence of a parenchymatous tumor. An increase in tumor size was detected on chest computer tomography (CT) scan. Using a pump oxygenator, median sternotomy was performed to reach the epicardium. A pale yellow, soft tumor was seen in the left atrium near the left ventricle. Histologically, the patient was diagnosed as having a malignant schwannoma. We have reported a case of primary malignant schwannoma which was surmised to have arisen from the boundary between the atrium and the ventricle.

Adult↗

Alumina ceramic prosthesis arthroplasty of the metacarpophalangeal joint in the rheumatoid hand. A 2-4-year follow-up study.

Swanson's finger implant is being widely used to improve deformity of the thumb and finger and to restore function in the rheumatoid hand. Breakage of the implant and implant synovitis have been the most troublesome complications. The authors developed an alumina ceramic finger prosthesis to lessen these complications. This prosthesis was used for the metacarpophalangeal joint in 5 cases of flexion deformity of the thumb and in 21 cases (82 digits) with ulnar drift deformity. These cases were followed for 24-62 months (average, 38 months). Postoperative extension of the thumb was limited to 18 degrees and flexion was 48 degrees, on average. Postoperative range of motion was 30 degrees. The average limitation of extension of all digits was 18 degrees, and the average flexion was 54.5 degrees. The average range of motion was 36.5 degrees. Flexion deformity of the metacarpophalangeal joint of the thumb disappeared after operation, and ulnar drift was reduced to less than 10 degrees deviation in 87.8%. No dislocation or fracture of the prosthesis has been found on roentgenologic examination during short-term follow-up study. This prosthesis is useful for reducing deformity of the thumb and the finger in the rheumatoid hand. Postoperative extension of the metacarpophalangeal joint, however, has been unsatisfactory. The design of the prosthesis should be improved so that the rotational center of the metacarpophalangeal joint is located palmarly.

Adult↗

[Evaluation of cardiovascular responses to handgrip tests in patients with ischemic heart disease by radionuclide method].

Left ventricular responses to handgrip exercise test in patients with ischemic heart disease were assessed by RI methods. We subdivided into three groups (A: delta EF more than 5% increased, B: delta EF -5%-+5% no change, C: delta EF less than 5% reduced), left ventricular contractility (LVEF/LVET) and Tl defect score changed significantly in global EF reduced group, moreover the usefulness of handgrip test was assured. This instrument is low cost, safety, small size, and available for wide ranged ages.

Blood Pressure↗

Nonunion of the capitate.

A case of nonunion of the capitate of a 13-year-old girl is reported. Autogenous iliac bone grafting obtained union. At the 2-year follow-up, she had no complaints and had full motion of the wrist.

Adolescent↗

Certain neuroleptics reduce bone mineralization in schizophrenic patients.

A significant increase of urinary Ca and hydroxyproline levels and a decrease of urinary alkaline phosphatase activity were found in 12 schizophrenic patients receiving certain neuroleptic drugs. In these patients, the levels of active metabolites of vitamin D3 were decreased, while the levels of midmolecule parathyroid hormone were within the normal range, except for 2 cases. These results suggest that certain neuroleptics induce the increased urinary Ca excretion through suppression of active vitamin D3 formation and that chronic treatment with certain neuroleptics may induce abnormal bone mineralization.

Adolescent↗