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Biomedical subjects

A Seki

Publications and source records attributed to A Seki.

At least 199 records · Page 11Linked to original sources

Congenital generalized lipodystrophy with insulin-resistant diabetes.

Hyperglycemia, glucose intolerance, hyperinsulinemia and resistance to exogenous insulin were found in a 10-year-old Japanese boy diagnosed as having congenital generalized lipodystrophy. Studies on insulin receptors of circulating mononuclear leucocytes indicated that insulin-resistant diabetes combined with congenital generalized lipodystrophy may be due to disturbance of insulin binding to membrane receptors. No insulin-binding antibody or antibody that impairs insulin-receptor binding was found. Plasma glucagon showed an exaggerated response to L-arginine before treatment. After treatment with a controlled diet and an oral sulfonylurea (500 mg/day) for 4 weeks, there was improvement in the plasma glucagon response to L-arginine. Improvement in the hyperglycemia, hyperinsulinemia and acanthosis nigricans was also observed. On the other hand, on completion of a 7-day high-fat diet, a marked increase in serum free fatty acids, triglycerides and beta-lipoproteins was observed. The total plasma post-heparin lipolytic activity during the high fat diet was within the normal range. However, the level of protamine-inactivated activity was 3 times that of the control.

Acanthosis Nigricans↗

Ultrastructure of an anaplastic giant-cell carcinoma found 8 years after operation on a papillary carcinoma of the thyroid.

Light and electron microscopic studies have been made on an anaplastic giant-cell tumor that developed in a woman 8 years after an operation on the thyroid for papillary carcinoma. Many giant cells were observed in the anaplastic tumor tissue, but no follicles. Numerous tightly-packed mitochondria and abundant ribosomes were present, but there were no desmosomes. The basement membrane was not distinct.

Aged↗

Effect of amyl nitrite inhalation on the abnormal T loop of vectorcardiogram.

The effect of amyl nitrite (AN) on the vectorcardiographic T loop was studied in 17 cases who had negative T waves in the left chest leads of ECG. Thirty sec after AN inhalation the maximum T vector was displaced to the left and anteriorly in 15 and to the left and posteriorly in 2 cases. The magnitude of maximum spatial T vector was decreased and the spatial T loop became more circular. Changes in the amplitude of T loop projected to the scalar lead X were closely related with changes in the heart rate which would represent the sympathetic tone.

Adult↗

Increased vascular permeability of developing collateral arteries after femoral artery ligation in rabbits.

Ligation of the main femoral artery is followed by a rapid development of collateral arteries. To detect an increase in vascular permeability of the collateral arteries, colloidal carbon (1 ml/Kg, iv) was injected into 153 rabbits at various times after ligation or sham-ligation of the main femoral artery. These animals were killed later and collateral arteries was dissected. Increase in vascular permeability was identified by the presence of visible carbon deposits on the vascular walls. The carbon deposits were frequently found on the intermediate segments of the collateral system in legs with ligation, but were not found on any arteries either in legs with sham-ligation or in contralateral untouched legs. The increase in vascular permeability was observed in 15 of 17 animals as early as 6 hours, in 32 of 36 animals 1 day but only in 5 of 21 animals 6 to 8 days after ligation. The arterial segments with carbon deposits showed various structural changes such as fragmentation of the internal elastic layer, degeneration of the medial muscle and deposition of fibrinoid material. These results indicate that vascular permeability transiently increases in the intermediate segments of developing collateral arteries. Acute vasodilatation may be responsible for the increase in vascular permeability.

Animals↗

Increased weight and protein contents of the aorta and left ventricle in acute Goldblatt hypertension.

The weight and protein contents of the aorta and left ventricle were measured in rabbits with two-kidney or one-kidney Goldblatt hypertension (group 2H and group 1H) and in respective control animals (group 2C and group 1C). 14 days after a renal artery constriction the protein contents of the aorta were greater in group 2H (124+/-3 mg) than in group 2C (95+/-2 mg) (p less than 0.001) and in group 1H (124+/-5 mg) than in group 1C (102+/-4 mg) (p less than 0.001). The weight and protein contents of the aorta and of the left ventricle were also significantly greater in group 1H and group 2H than in group 1C and group 2C respectively. Furthermore in both types of hypertension the weight and protein contents of these two organs significantly correlated to the blood pressure. These results indicate that hypertrophy of the aorta as well as the left ventricle develops already in early developing stage of Goldblatt hypertension.

Animals↗

The coordination of gastrointestinal hormones and the autonomic nerves.

We have conducted investigations on the relationship between gastrointestinal hormones and the autonomic nervous system. In this paper are described main themes of our investigations where a close association between gastrointestinal hormones and the autonomic nervous system was shown from the functional and morphological points of view. The "nervism" proposed by Pavlov, where the regulation of various organs in the body was thought to be accomplished wholly by the nervous system, was based on the findings on the physiology of the digestive glands. In the meantime, the discovery of secretin from the duodenal mucosa led Bayliss and Starling to propose a chemical co-ordination or a humoral regulatory mechanism in addition to the nervous system for the regulation of the various organs in the body. It is indeed surprising that the principle of two major regulatory mechanisms in the body was thus developed originally on the basic studies of the exocrine and endocrine function of the digestive system. Our investigations reported in this paper disclosed the fact that the neural and humoral regulatory mechanisms for gastrointestinal secretions acted not separately but in close association both morphologically and functionally.

Abdomen↗

Responses of plasma renin to sodium load in two types of experimental renal hypertension.

A sodium-rich diet was given 20 rabbits with 2-kidney hypertension (clipping of one renal artery with an intact contralateral kidney), 19 rabbits with 1-kidney hypertension (clipping of one renal artery with contralateral nephrectomy), and 13 normal rabbits. Sodium content of the diet was twice as much as the regular diet. The sodium load was started 10 weeks after clipping of the renal artery and lasted for 2 weeks. During the sodium load blood pressure did not show any significant changes but hematocrit was reduced in all 3 groups. Plasma renin activity (PRA) was clearly suppressed in 10 of 19 animals with 1-kidney hypertension and in 6 of 13 normal animals, but only in 4 of 20 animals with 2-kidney hypertension (p less than 0.04). The results indicate that PRA was more easily suppressed in animals with 1-kidney hypertension than in those with 2-kidney hypertension by a sodium-rich diet and the suppressive response is not associated with alterations in blood pressure.

Animals↗

Increase of hematocrit in experimental renal hypertension and its reversal.

Hematocrit can be increased in experimental animals with renal hypertension of two-kidney type. The present study showed that the increased hematocrit was returned to normal by removal of the clipped kidney. The left renal artery was clipped in 13 rabbits with an intact contralateral kidney, and a sham operation was performed in 10 rabbits as a control. After an interval of 10 weeks the left kidney was removed in all animals. Blood pressure, hematocrit, hemoglobin content, and erythrocyte count were rapidly increased and remained raised after clipping of the renal artery but they did not show any significant changes after sham operation. A transient but significant increase of reticulocyte count was found at the end of the first week after clipping of the renal artery. Removal of the clipped kidney was followed by a rapid return of hematocrit, hemoglobin content, and erythrocyte count to normal within 2 weeks. Blood pressure was also decreased but not returned to normal by removal of the clipped kidney.

Animals↗

Peri-ureteric collateral vessels in rabbits with experimental renal hypertension.

The development of collaterals to an ischemic kidney was studied in rabbits with two-kidney Goldblatt hypertension. Hypertension was produced by applying a silver clip of 0.9 mm in internal diameter on the left renal artery with the right kidney intact. Peri-ureteric collaterals were found at autopsy in 27 (32.9%) of 82 animals that were killed 7 days (early stage) and in 30 (40.5%) of 74 animals that were killed in more than 70 days (late stage) after clipping. The average blood pressure was 123.8 +/- 2.6 (SE) mmHg in animals with collaterals vs. 125.3 +/- 2.1 mmHg in animals without them in the early stage, and 142.5 +/- 4.4 mm Hg in animals with collaterals vs. 122.6 +/- 3.3 mmHg in animals without them in the late stage. These results indicate that the collaterals to an ischemic kidney develop independently of the rises in blood pressure during the first week and the presence of collaterals is associated with moderate to severe hypertension in the late stage.

Animals↗

The content and turnover of norepinephrine in the rabbit brain regions and cardiovascular tissues.

The content and turnover of norepinephrine (NE) in the hypothalamus, midbrain, pons-medulla, mesenteric artery, aorta and left ventricle were studied in the normal rabbit. Turnover rate of NE was determined by measuring the rate of decline in NE content of the tissue after blockade of synthesis with alpha-methyl-p-tyrosine. The NE content of the hypothalamus (1.44+/-0.03 microgram/g) was significantly higher than those of the midbrain (0.25+/-0.01 microgram/g) and the pons-medulla (0.36+/-0.01 microgram/g) (p less than 0.001), whereas the rate constant of NE turnover for the pons-medulla (0.213+/-0.009 hr-1) was significantly greater than those for the hypothalamus (0.164+/-0.008 hr-1, p less than 0.001) and the midbrain (0.180+/-0.008 hr-1, p less than 0.01). In the cardiovascular tissues examined, the NE content was highest in the mesenteric artery (6.33+/-0.19 microgram/g), moderate in the left ventricle (2.08+/-0.10 microgram/g) and lowest in the aorta (0.70+/-0.06 microgram/g). The differences among them were significant (p less than 0.001). However, the rate constant of NE turnover for the aorta (0.119+/-0.014 hr-1) was significantly greater than those for the mesenteric artery (0.059+/-0.008 hr-1, p less than 0.001) and the left ventricle (0.069+/-0.006 hr-1, p less than 0.005). The turnover rate of NE in the mesenteric artery was high, 0.372 microgram/g-hr, which suggests the very active NE synthesis. These results indicate that there are regional differences in content and turnover of NE of the cardiovascular tissues as well as of the brain.

Animals↗

Mild variant of maple syrup urine disease.

Amino acids analysis were made on serum and cerebrospinal fluid samples of a Japanese 5-month-old infant suffering from irritability and mental retardation noticed at 2 months of age. Excessive amounts of branched-chain amino acids and of keto acids were detected in those samples and the large quantity of keto acids was found in urine with a qualitative 2,4-dinitro-phenyl-hydrazin test and with quantitative estimation. When thiamine hydrochloride (100 mg/day) was administered orally for 7 days to the patient fed with the cow's milk formula containing 2.1 gm/dl milk protein, there was no improvement of the branched-chain amino acidemia. Urinary keto acids, however, showed a marked decrease 7 days after the administration of thiamine hydrochloride. An overnight fast for 13 h resulted in normoglycemia. There was found no difference of blood L-lencine level between both parents and normal infants to whom L-leucine was loaded. The relation between decarboxylase activity for keto acids of branched-chain amino acids and thiamine hydrochloride was studied clinically, in the present communication.

Amino Acids↗