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M Hamada

Publications and source records attributed to M Hamada.

At least 577 records · Page 32Linked to original sources
PubMed1983

[Detectability of stress-induced ischemic lesion in previous myocardial infarction using 201T1 myocardial single photon emission computed tomography].

The purpose of this study was to evaluate the detectability of stress-induced ischemic lesion in patients with previous myocardial infarction using single photon emission computed tomography (SPECT) producing thallium-201 (T1-201) myocardial perfusion imagings (MPI). Seventy patients underwent stress SPECT by symptom-limited graded bicycle ergometer exercise using a dual-headed rotating gamma camera (Toshiba GCA70A) equipped with a computer system (GMS90). After intravenous administration of 2.5 mCi of T1-201, stress SPECT data at 10 minutes and delayed SPECT data at 3 hours after the injection were collected in the 64 X 64 matrix form covering 360 degrees directions by camera sweep of 180 degrees in 6 minutes, which were immediately followed by conventional planar imagings (PL). Transaxial tomographic image reconstruction was performed by convolution method using a Shepp-Logan's filter. Thereafter, sagittal and coronal tomographic images were reconstructed for about 2 minutes. Image interpretation was assessed visually. The results were as follows: Sensitivity and specificity in detecting the affected vessel with more than 75% stenosis by segmental analysis of myocardial images were higher by SPECT than by PL (LAD 89% and 65%, LCX 68% and 56%, RCA 89% and 76% in sensitivity and LAD 94% and LCX 75%, 92% and 94%, RCA 81% and 59% in specificity, respectively). Sensitivity in detecting both single (82%) and multivessel disease (76%) was fairly high. Detectability of stress-induced ischemia (i.e. occurrence of a new defect in patients with previous myocardial infarction and ST-segment depression in ECG) was significantly higher in SPECT (67%) than in PL (39%, p less than 0.005) and in ECG (39%, p less than 0.005). A perfusion defect in the extensive anterior wall, marked left ventricular dilatation and the widening of the angle toward the apex composed of septal and anterolateral walls in transaxial images were the findings characteristic of anterior myocardial infarction with severe dyskinesis. We conclude that stress SPECT is a useful noninvasive technique for the documentation of the number of vessels affected and severe wall motion abnormality of the LV and for the detection of stress-induced ischemia in previous myocardial infarction.

Electrocardiography↗
PubMed1982

Plasma lipids and lipoproteins in Japanese male patients with coronary artery disease and in their relatives.

Plasma cholesterol (CH), triglyceride (TG) and high density lipoprotein cholesterol (HDL-C) were measured in 92 consecutive Japanese male subjects undergoing diagnostic coronary cineangiography. Sixty-nine of them were classified as having coronary artery disease (CAD), the remaining 23 subjects were classified as having normal coronary arteries (NCA). The CAD group had significantly lower HDL-C and higher TG levels than the NCA group. However, there was no significant difference in plasma CH between the two groups. First-degree relatives of the CAD patients were also investigated. The male blood relatives of the CAD patients also had significantly lower HDL-C and higher TG levels than the non-blood male relatives and healthy control males. The female blood relatives, however, showed no significant differences from the non-blood female relatives and the healthy control females in plasma CH, TG and HDL-C levels. These results suggest that low HDL-C and hypertriglyceridemia are the prevalent coronary risk factors, rather than hypercholesterolemia, in a population with a low fat intake such as the Japanese, and that these lipid abnormalities are related to sex and genetic factors.

Adult↗
PubMed1982

Afterloading technique for interstitial irradiation of lesions in deep-seated organs.

An afterloading procedure using iridium 192 seeds was developed for the control of both localized primary lesions that are difficult to remove and superficial residual lesions that remain after the partial removal of tumors in relatively inaccessible, deep-seated organs. This technique makes possible the delivery of a minimal radiation dose to lesions in deep-seated organs. Fewer complications result, the seeds can be adjusted at appropriate intervals in proportion to the amount of radioactivity desired, and radiation exposure to personnel can be reduced. This paper describes the techniques and apparatus used to place the seeds in the tubing. Primary lesions of the urinary bladder, the prostate gland, and the esophagus, residual lesions in the brain and lung, and metastases in intrapelvic lymph nodes were treated. No technical difficulties or complications were encountered. Radiation exposures to personnel were minimized. The results indicate that the procedure has practical applications.

Brachytherapy↗
PubMed1982

Is captopril effective in primary pulmonary hypertension?

Several vasodilating agents have been used for the treatment of primary pulmonary hypertension (PPH). However, no effective therapy is currently available for this distressful disease. We tried to use an angiotensin-I converting enzyme inhibitor, captopril, for one woman suffering from PPH. Her initial treatment with furosemide, digoxin and spironolactone had shown little effect. Further administration of captopril improved her clinical condition from NYHA IV to II and made it possible to treat her at our out-clinic. No adverse effect has been found. We would like to appreciate captopril as one of the effective drugs in the treatment of PPH.

Captopril↗
PubMed1982

Studies of tylosin derivatives effective against macrolide-resistant strains: synthesis and structure-activity relationships.

The 4"-O-substituted tylosin derivatives were prepared by selective esterification of the 4"-OH, and relationships between the substituent groups and antimicrobial activity against macrolide-resistant strains were examined. Introduction of branched-chain aliphatic acyl groups such as 2-methoxyisovaleryl or 4-methylvaleryl group afforded derivatives with good antibacterial activity; MIC values were 12.5 microgram/ml against Staphylococcus aureus MS-8710. MIC values of tylosin, erythromycin and josamycin against this strain were 800 microgram/ml or more. Further improved activity was obtained by introduction of aromatic groups such as phenylthioacetyl, phenylsulfonylacetyl, 4-nitrophenylacetyl, 4-nitrophenylsulfonyl and phenylethanesulfonyl groups; MIC values were 6.25 microgram/ml. These derivatives had also an improved antimycoplasmal activity; MIC values were 0.08 microgram/ml against macrolide-resistant strains of Mycoplasma gallisepticum. MIC values of tylosin against these strains were from 2.5 to 10 microgram/ml. Introduction of the groups described above into the 4"-OH was confirmed to increase the uptake by a resistant strain.

Anti-Bacterial Agents↗