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Biomedical subjects

S Go

Publications and source records attributed to S Go.

At least 37 records · Page 2Linked to original sources

Effects of castration and testosterone administration on serum lipoproteins and their apoproteins in male spontaneously hypertensive rat.

Serum triglyceride and very low density lipoprotein (VLDL) concentrations were higher in male spontaneously hypertensive rat than in male control Wistar Kyoto rat, whereas serum cholesterol, phospholipids, and high density lipoprotein (HDL) concentrations were lower. Castration of hypertensive rats induced an increase in serum cholesterol, phospholipids, and HDL, and a decrease in serum triglyceride and VLDL. The cholesterol content of HDL increased, whereas the triglycerides decreased after gonadectomy of hypertensive rats. These changes in serum lipids and lipoproteins could be reversed by the administration of testosterone. Apolipoprotein E contents in VLDL and HDL of hypertensive rats were low when compared with control rats but rose after castration and could be reduced by testosterone administration. Hypertensive rats accumulated triglycerides and cholesterol in the liver, which resulted in an increase of liver weight. Castration reduced the hepatic lipids as well as liver weight. The effects of castration and testosterone treatment on lipids and lipoproteins were more prominent in spontaneously hypertensive rats than in control rats. These results suggest that testosterone reduces VLDL catabolism which is related to changes of apolipoprotein composition, and that hypertensive rats are more sensitive to testosterone than control rats.

Animals↗

Aging changes of riboflavin concentration and glutathione reductase activity in erythrocytes.

Aged erythrocytes obtained by fractionation using gradient centrifugation with Dextran 40, showed lower glutathione reductase activity and riboflavin content than young cells. However, both young and old cells displayed almost the same increase in enzyme activity upon addition of flavin adenine dinucleotide to the test hemolysate in vitro. The lipid peroxide content in the cell membranes showed no consistent changes with aging.

Centrifugation, Density Gradient↗

The inactive to active renin ratio in the kidneys and the plasma in diabetic nephropathy.

We examined the inactive to active renin ratio in the renin granules of the cadaver kidneys and the plasma in patients with diabetic nephropathy. The inactive renin in the break-through fraction when the plasma or the renin from the renin granules was put into a pepstatin column was determined. The inactive renin in this fraction was activated by trypsin. Concerning plasma, the inactive to active renin ratio was 90 in the patients and 9 in the normal subjects. On the other hand, this ratio was 0.29 in the patients' kidneys and 0.28 in the control kidneys. These results suggest that the increase of the inactive to active renin ratio in plasma of diabetic nephropathy does not result from the change of the renin storage in the kidneys.

Blood Proteins↗

Absence of increase of histidine decarboxylase activity in mast cell-deficient W/W mouse embryos before parturition.

The histidine decarboxylase (L-histidine carboxylase, EC 4.1.1.22) activity of whole W/W mouse embryos, which are devoid of mast cells, remained very low and did not show the rapid increase before birth (17-20 days of gestation) seen in wild-type +/+ embryos. During the same period, the histamine content also remained very low and no mast cells were detected in the W/W embryos, in the contrast to the large increase in both histamine content and number of mast cells in wild-type embryos. These findings imply that the histamine in embryos is largely derived from mast cells. In +/+ mice, histidine decarboxylase activity decreased rapidly soon after birth without concomitant decrease in histamine content or number of mast cells, suggesting that the enzyme activity in mast cells is regulated by some unknown mechanism.

Age Factors↗

An autopsied case of an elementary school boy with sudden death four years after Kawasaki disease: on the problem of present method of cardiac mass screening of school children.

An 8 year-old boy died suddenly 4 years after the onset of Kawasaki disease. He was examined by a cardiac mass screening for school children one and a half year before the death, and was evaluated as having no sequela of Kawasaki disease. The autopsy showed coronary arterial aneurysms and obstruction with fresh and old myocardial infarction. One of the problems of the present method for cardiac mass screening for school children is that it is performed only with history taking, physical findings and electrocardiograms. This method is completely insufficient to find out coronary involvement as a sequela of Kawasaki disease. All the children with history of Kawasaki disease should be examined by two dimensional echocardiography, which is the most sensitive and specific noninvasive method to detect the coronary involvement in our experience.

Autopsy↗

Cardiac biopsy of Kawasaki disease.

Two hundred one patients (138 boys, 63 girls), 1 month to 11 years old, with Kawasaki disease underwent coronary angiography, ultrasonic tomography, myocardial imaging, and biopsy of right ventricular myocardium. Aneurysms of epicardial coronary arteries, mostly left, occurred in 26 cases (12.9%). Degeneration and proliferation of endothelium, edema, scarring, and fibrosis, slight to moderate, involved the tunicae of intramural small vessels in all cases. These changes tended to abate with time. The basic lesion of Kawasaki disease, round-cell myocarditis and fibrosis, involved all cases and persisted. Disarrangement, abnormal branching, disarray, and hypertrophy of myocytes correlated significantly with myocarditis, but not with epimural or intramural coronary angitis. As a consequence of the myocardial changes, it is suggested that some cases may terminate as myocardiopathy. Scoring criteria for vascular and myocardial changes in biopsy specimens are included.

Biopsy↗

Distribution of mast-cell precursors in hematopoeitic and lymphopoietic tissues of mice.

Two experimental systems were used to investigate the origin of precursor cells which differentiate into tissue mast cells in vivo. (a) Increase of mast cell number was examined in the skin, stomach, cecum, and mesentery of genetically mast cell-depleted WBB6F1 (WB X C57BL/6)-W/WV mice after the injection of various hematolymphoid cells of congenic +/+ mice. (b) Appearance of mast cells with giant granules was studied in irradiated C57BL/6-+/+ mice after the injection of lymphoid cells of C57BL/6-bgJ/bgJ (beige, Chediak-Higashi syndrome) mice. Concentrations of mast cell precursors in the thymus, lymph node and Peyer's patch were less than 0.1% of the concentration in the bone marrow. Neither treatment of donor bone marrow cells with anti-Thy-1.2 serum and complement nor thymectomy of the recipient mice affects the development of mast cells in the skin, stomach, cecum, and mesentery. Moreover, the number of mast cells increased to normal level when the skin of WBB6F1-W/WV mice was grafted on the back of nude athymic (BALB/c-nu/nu) mice. These results indicate that mast cell precursors are derived from hematopoietic tissues rather than lymphopoetic ones and that the differentiation of the precursor cells does not depend on T lymphocytes or the thymus.

Animals↗