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Biomedical subjects

Y Inagaki

Publications and source records attributed to Y Inagaki.

At least 199 records · Page 11Linked to original sources
PubMed1992

High-energy phosphate metabolism of the myocardium in normal subjects and patients with various cardiomyopathies--the study using ECG gated MR spectroscopy with a localization technique.

Nuclear magnetic resonance spectroscopy (MRS) is a new technique for the evaluation of myocardial metabolism. Recently, localized MRS has been clinically available to measure by a non-invasive method the relative concentrations of the high-energy phosphate metabolites in the myocardium. We performed ECG gated P-31 MRS using ISIS (image-selected in vivo spectroscopy) in 15 normal volunteers, 12 patients with hypertrophic cardiomyopathy, 12 with left ventricular hypertrophy, 6 with dilated cardiomyopathy and 11 with specific heart muscle disease. Myocardial peak height ratios of PCr/gamma-ATP, Pi/gamma-ATP and PCr/Pi were measured. Myocardial P-31 MRS demonstrated a significant decrease in the ratio PCr/ATP in patients with hypertrophic cardiomyopathy and specific heart muscle disease as compared with normal subjects, indicating myocardial metabolic disturbance in these patients. The ratio of PCr/ATP in patients with dilated cardiomyopathy did not differ significantly from that of normal subjects. However, exercise MRS revealed a marked decrease of PCr peak in an asymptomatic patient with dilated cardiomyopathy, which may indicate a latent metabolic disturbance in the myocardium of dilated cardiomyopathy.

Adenosine Triphosphate↗
PubMed1992

Expansion rate of thoracic aortic aneurysms and influencing factors.

The risk of rupture of an aortic aneurysm increases with size and rapid expansion rate. We studied the expansion rate of thoracic aortic aneurysms and the factors influencing expansion rate, and compared the results with those of abdominal aortic aneurysms. Forty thoracic aortic aneurysms and 25 abdominal aortic aneurysms were serially examined with enhanced and nonenhanced computed tomography. The mean expansion rate of thoracic aortic aneurysms was 1.3 +/- 1.2 mm/yr and was significantly lower than 3.9 +/- 3.2 mm/yr of abdominal aortic aneurysms. The factors increasing expansion rate of thoracic aortic aneurysms were initial size of aneurysms, diastolic blood pressure, and presence of renal failure by univariate analysis. Multivariate analysis concerning the entire aortic aneurysms also revealed that the large size of the aneurysm and the presence of the aortic aneurysm in the abdomen increased expansion rate of aneurysms.

Aged↗
PubMed1992

Unoperated thoracic aortic aneurysms: survival rates of the patients and determinants of prognosis.

The purpose of this study was to evaluate the long-term prognosis of unoperated thoracic aortic aneurysms, and to detect the risk factors which determine the prognosis of unoperated patients. The subjects were 52 unoperated patients with 58 thoracic aortic aneurysms (22 of the ascending aorta, 36 of the descending aorta or the aortic arch) and 38 with abdominal aortic aneurysms. The survival rates of the patients with ascending aortic aneurysms at 3 years and 5 years and those of the patients with descending aortic aneurysms at 5 years were significantly higher than those of the patients with abdominal aortic aneurysms. The risk factors for rupture of thoracic aortic aneurysms were the large size of aneurysms and non-management by the cardiologist and the risk factors for death unrelated to the aneurysms were patient age, male gender and non-management by the cardiologist.

Age Factors↗
PubMed1992

[Left ventricular trabeculae evaluated with MRI in dilated cardiomyopathy and old myocardial infarction].

The morphological examination of the left ventricular trabeculae was performed using MRI (0.5T) in 14 normal volunteers, 12 patients with dilated cardiomyopathy (DCM), and 9 patients with old myocardial infarction (OMI). Left ventricular trabeculae were observed at the free walls of the left ventricle in all subjects, but not at the septal wall. Left ventricular trabeculae were larger in DCM than in the normals. The trabeculae were scarce in OMI and inner sides of the infarcted myocardium were very smooth. The development of the left ventricular trabeculae was graded as diminished, ordinary, and marked. Ordinary trabeculae were seen in 86% of the normals, whereas; marked trabeculae in 75% of DCM, and diminished trabeculae in 78% of OMI. In patients with DCM, the mean area of the left ventricle with marked trabeculae was greater than that with ordinary trabeculae. The more dilated left ventricle, the thinner the anterior wall was and the lower the ejection fraction was in DCM and OMI, though there were no significant differences in values of these 3 items between DCM and OMI. The MRI findings on the development of the trabeculae were confirmed in patients with DCM at autopsy. Thus, the MRI findings were very useful in the differential diagnosis between DCM and OMI.

Adult↗
PubMed1992

Effect of nipradilol on cardiovascular hemodynamics during exercise in angina pectoris with old myocardial infarction.

Nipradilol (3,4-dihydro-(2-hydroxy-3-isopropylamino)-propoxy-3-nitroxy-2H-1- benzopyran, K-351, CAS 81486-22-8) is a new type of beta-blocker with vasodilating action. The effect of nipradilol on hemodynamics at rest and during exercise with a multi-stage bicycle ergometer in supine position was studied in 8 male patients suffering from angina pectoris with old myocardial infarction. Nipradilol was orally given at the daily dose of 12 mg (b.i.d.) for one week, and various hemodynamic parameters were measured at rest and during exercise before and after the treatment with nipradilol. At rest, the blood pressure was almost unchanged, heart rate was significantly reduced, cardiac output tended to decrease, and the pulmonary blood pressure and left ventricular ejection fraction (EF) were almost unchanged. At peak exercise, the blood pressure tended to decline, heart rate was significantly reduced, cardiac output tended to decrease and the pulmonary blood pressure and EF increased significantly. Consequently, the antianginal effect of nipradilol is considered to be attributable to the reduction in myocardial oxygen consumption caused by a decrease in double product. It is thus suggested that nipradilol exerts its antianginal effect without adversely affecting the cardiac performance.

Adrenergic beta-Antagonists↗
PubMed1992

[Pulmonary kinetics of 13N-ammonia in smoking subjects--a quantitative study using dynamic PET].

To evaluate the effect of smoking on nonrespiratory function in the lung, a dynamic PET with 13NH3 in the lung was performed in 18 normal volunteers without lung disease nor congestion (9 non-smokers, 4 exsmokers, 5 smokers). After intravenous bolus injection of 13NH3, twenty serial 5.5-second scans followed by six 30-second scans were performed. Regions of interests were assigned on the ventral, lateral and dorsal part of the right lung and time-activity curves were generated through 26 images. The activity curve demonstrated a biexponential clearance from the lung with fast and slow component. The retention fraction (RF), fractional size of the slow component, was calculated, and the half-times (t 1/2) of both components were also evaluated. A significant increase of RF and prolongation of t 1/2 of slow component were observed in smokers compared to non-smokers and exsmokers. However, no significant difference of RF nor t 1/2 of both components was observed between non-smokers and exsmokers. These results suggest that long term smoking may modify the pulmonary kinetics of 13NH3, but the change is reversible after cessation of smoking for one year or longer.

Adult↗
PubMed1992

[Effect of DQ-2556, a new cephalosporin derivative, on fecal microflora].

A new cephalosporin derivative antibacterial agent, DQ-2556, was administered intravenously to 4 healthy adult male volunteers at 2 grams per dosage 2 times a day for 5 days, and degrees of effects of drug concentrations on the fecal microflora were investigated. 1. The total viable count remained unchanged during the study period due to the minimal change in the number of members of the family Bacteroidaceae, which were the most dominant organisms. In one of the volunteers, however, the total count was remarkably reduced immediately after the end of administration of the drug. 2. Among the obligate anaerobes, most of the organisms decreased except members of the family Bacteroidaceae. A marked increase of lecithinase-positive clostridia was noted in 2 volunteers. 3. The number of aerobes, including facultative anaerobes, members of the family Enterobacteriaceae were suppressed but bacilli and yeasts showed slight increases. In many cases, increases in enterococci were also observed. 4. DQ-2556 was not detected in the feces from any of the volunteers during the study period. 5. Neither Clostridium difficile nor its toxin D-1 was detected in any of the volunteers. 6. Diarrhoea or other side-effects were not noted in any of the volunteers.

Adult↗
PubMed1992

[Usefulness of 18F-fluorodeoxyglucose positron emission tomography for evaluating myocardial viability in old myocardial infarction].

The purpose of this study is to compare the characteristics of images obtained by positron emission tomography (PET) using 18F-fluorodeoxyglucose (FDG) in the fasted state (> 6 hours) and in the glucose-loaded state (oral 50 g glucose load). In the both condition FDG-PET were performed in 18 cases with old myocardial infarction. PET images in the fasted state were divided into 2 groups (Group A; 12 cases and Group B; 6 cases). FDG uptake of normal region was visually absent (grade 0) in group A, whereas it was visually apparent (grade 1-3) in group B. Serum free fatty acid in group B was significantly lower than that in group A. In the 7 cases, the relation between myocardial FDG uptake of the infarcted regions and reversibility after coronary intervention was studied. Both in the fasted and in the glucose-loaded state, postoperative improvement was observed in the segments, in which myocardial uptake of FDG were visually apparent (glucose-loaded state, 11/13 segments; fasted state, 6/8 segments). Therefore FDG-PET images appeared to be useful for evaluating myocardial viability.

Aged↗
PubMed1992

The effect of levofloxacin, an optically-active isomer of ofloxacin, on fecal microflora in human volunteers.

Following oral administration of levofloxacin (LVFX, (S)-(-)-Ofloxacin; formerly designated as DR-3355) at 200 mg per dose 3 times a day for 7 days to 6 healthy male volunteers, degrees of disturbance of the fecal microflora and fecal drug concentrations were examined. The total viable count remained unchanged during the study period due to the minimal change in the number of members of the family Bacteroidaceae, the most predominant organisms. Most of the aerobes including facultative anaerobes were suppressed by LVFX with only a slight increase in yeasts. In particular, the members of the family Enterobacteriaceae were reduced to below the detection limit on and after day 3 through the time of discontinuation of the drug in all subjects but one. Among the obligate anaerobes, peptostreptococci and bifidobacteria decreased or disappeared in some volunteers, but no significant changes were observed in other anaerobes. Neither Clostridium difficile nor its toxin D-1 was detected in any of the volunteers. No side effects attributable to the drug were observed. During administration, LVFX was detected in the feces at high concentrations which correlated well with the decrease of susceptible members of flora as well as to their detection rate.

Adult↗
PubMed1992

[A hypertensive crisis during surgery in a patient with neuroblastoma].

Neuroblastoma is the most common solid tumour in infancy and childhood. The tumour usually produces large amounts of catecholamines. Few patients with neuroblastoma, however, were reported to have become hypertensive because of catecholamine metabolism within the tumour itself. This is one of the most important differences compared with pheochromocytomas. We experienced a hypertensive crisis accompanied by tachycardia and an increase in the plasma catecholamine concentration during surgery in a patient with neuroblastoma. The plasma catecholamine level was comparable to that of pheochromocytoma. Phentolamine and propranolol were effective to control the hypertension and tachycardia.

Catecholamines↗