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Biomedical subjects

H Maezawa

Publications and source records attributed to H Maezawa.

At least 91 records · Page 5Linked to original sources
PubMed1986

Morphological and functional differentiation of cultured vascular smooth-muscle cells.

In numerous investigations using cultured smooth-muscle cells, investigators have consistently added 10-20% fetal calf serum (FCS) to the medium to maintain viable cells. In the present study we utilized an optical technique to investigate whether smooth-muscle cells, cultured with or without FCS, maintain their contractile activity in vitro. With such optical measurement, we were able to detect signals due to spontaneous contractions, in muscle cells cultured in FCS-free medium for up to 8 days, and, for the first time, were also able to observe the conduction of these cell contractions. The ultrastructural characteristics of cultured smooth-muscle cells during contractile activity, were also examined by electron microscopy. The cells were mature and well-differentiated, and were packed with numerous myofilaments. They had developed long cell processes, and were linked to one another by gap junctions. These observations indicated that the smooth-muscle cells, cultured without FCS for 7 to 8 days, were morphologically mature and maintained their contractile activity, whereas the cells cultured in FCS-containing medium showed no detectable signs of contractile activity.

Animals↗
PubMed1985

Relationship between the R-R interval variation and metabolic states of diabetes.

To investigate whether the metabolic state of diabetes affects the R-R interval variation, 82 diabetics were studied at intervals of about 1 month and of about 1 year. There was no significant relationship between the rate of change for FBG and that for R-R interval variation at both these intervals. However, in the cases that showed a change of HbA1 by more than 10% in a month, the rate of change for the R-R interval variation was 20 +/- 30% in the group with improved HbA1 and -9 +/- 17% in the group with aggravated HbA1, demonstrating a significant difference (P less than 0.05) between the 2 groups. There was a significant difference (P less than 0.02) in the rate of change for the R-R interval variation between the group with improved HbA1 by more than 5% and the group with aggravated HbA1 by more than 5%, when measured at intervals of 1 year. No special relationship was observed between the difference in R-R interval variation and each of the following: (1) the mean FBG for 1 year preceding the day of initial measurement of the R-R interval variation; (2) the mean FBG for the succeeding year; and (3) the difference in these 2. It was suggested that the R-R interval variation was likely to be affected by the metabolic state during the preceding 1-2 months.

Adult↗
PubMed1985

Electronmicroscopic autoradiographic study of the distribution of 3H-diltiazem in myocardial cells.

The distribution of 3H-diltiazem in myocardial cell organelles was studied using an electronmicroscopic autoradiographic technique. At 3, 5 and 10 min after 3H-diltiazem injection, silver grains, which indicate the existence of diltiazem, were detected in plasma membranes and intracellular organelles. Silver grains in T systems were observed more frequently at 3 min than at 5 and 10 min. In contrast, silver grains in sarcoplasmic reticula and mitochondria apparently increased with the passage of time. These findings suggest that diltiazem is transported through the T system and may accumulate within the sarcoplasmic reticula and mitochondria. Furthermore, our study revealed morphologically for the first time that the intracellular sites of action where diltiazem was directed were possibly the mitochondria.

Animals↗
PubMed1985

[Aortic dissection presenting aortic regurgitation induced by diastolic prolapse of an intimal flap into the left ventricle: a case report].

A case of aortic dissection associated with aortic regurgitation which was induced by diastolic prolapse of an intimal flap into the left ventricular outflow tract was reported. This 57-year-old man, referred for evaluation of sudden onset of chest oppression and a heart murmur, was hypertensive for several years. His admission blood pressure was 184/44 mmHg, and a systolic ejection murmur and a diastolic decrescendo murmur were audible along the left sternal border. Two-dimensional echocardiography revealed an intimal flap in the markedly enlarged aortic root. The intimal flap moved posteriorly in systole and anteriorly in diastole, and prolapsed into the left ventricular outflow tract during diastole. Associated with the movement of the intimal flap, an aortic cusp was shifted from its original position to the left ventricular outflow tract in diastole. Aortography disclosed type I aortic dissection and severe aortic regurgitation. After medical treatment for four months, the patient underwent a Bentall surgical procedure and recovered. Impaired coaptation of the aortic valve induced by diastolic prolapse of the intimal flap into the left ventricular outflow tract is a newly encountered echocardiographic finding in proximal aortic dissection.

Aortic Dissection↗
PubMed1985

Serum levels of lipids and apolipoproteins in angiographycally defined ischemic heart disease.

To determine the predictive risk factors of the severity of the coronary artery disease, the serum levels of lipoprotein cholesterol and apolipoprotein were measured in 103 patients undergoing coronary angiography examination for suspected myocardial ischemia. The extent and severity of the coronary artery disease (CAD) were assessed by assigning scores to each lesion. Twenty-six female patients (59 +/- 8 yrs.) showed a stronger relationship of apo B and apo A-I/B to the coronary scores than the 77 male patients (57 +/- 8 yrs.). The male patients were divided into four groups based on the coronary scores: H-CAD (range: over 11 points), M-CAD (5-10 points), L-CAD (1-4 points) and N-CAD (0 point). The atherogenic risk factors other than the abnormalities in lipid metabolism (obesity index, fasting plasma glucose, smoking and blood pressure) were well matched in the four groups. T.C., LDL-C., HDL-C., HDL2-C., apo B, apo A-I/B ratio and apo A-II/B ratio significantly differed in the H-CAD and N-CAD groups. These results indicate that T.C., LDL-C., HDL-C., HDL2-C., apo B, apo A-I/B ratio and apo A-II/B ratio are predictive risk factors of the coronary heart disease. Furthermore, apo B and apo A-I/B ratio significantly differed in the H-CAD and L-CAD groups. These results suggest that apo B and apo A-I/B ratio may be good discriminators of the severity of the coronary heart disease.

Aged↗