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Biomedical subjects

Y Ueda

Publications and source records attributed to Y Ueda.

At least 1,081 records · Page 60Linked to original sources

Role and control of isocitrate lyase in Candida lipolytica.

Mutants of Candida lipolytica that were unable to grow on acetate but able to utilize succinate or glycerol as a sole carbon source were isolated. Amongst the mutants isolated, one strain (Icl-) was specifically deficient in isocitrate lyase activity, whereas another strain (Acos-) was deficient in acetyl coenzyme A synthetase activity. Since the Icl- mutant could not grow either on n-alkane or its derivatives, such as fatty acid and long-chain dicarboxylic acid, any anaplerotic route other than the glyoxylate pathway was inconceivable as far as growth on these carbon sources was concerned. Acetyl coenzyme A is most likely a metabolic inducer of isocitrate lyase and malate synthase, because the Acos- mutant was characterized by the least susceptibility to induction of these enzymes by acetate. The structural gene for isocitrate lyase was most probably impaired in the Icl- mutant, since revertants (Icl-) produced thermolabile isocitrate lyase. The production of isocitrate from n-alkane by the revertants was enhanced in comparison with the parental strain.

Acetyl Coenzyme A↗

A simplified screening test for differentiating primary aldosteronism from essential hypertension with low plasma renin activity.

A simplified screening test for differentiating primary aldosteronism (PA) from low renin essential hypertension (LREH) is presented. Nine patients with LREH and 5 patients with PA due to adrenal adenoma were studied. In the patients with LREH, the levels of plasma renin activity (PRA) before and after treatment with furosemide (0.7 mg/kg, i.v.) and a 2-hour ambulation under treatment with dexamethasone (1.0 mg) (dexamethasone + furosemide test) increased briskly, compared to the levels of PRA before and after treatment with furosemide (0.7 mg/kg, i.v.) and a 2-hour ambulation (furosemide test). In patients with PA, there was no significant difference between the mean levels before the furosemide test and before the dexamethasone + furosemide test, or between the mean levels after the furosemide test and after the dexamethasone + furosemide test. These results suggest that the suppression of PRA in patients with LREH may be related to a factor controlled by dexamethasone. It is concluded that the dexamethasone + furosemide test is useful for differentiating PA due to adenoma from LREH.

Aldosterone↗

Effect of somatostatin on plasma renin activity and blood pressure in patients with essential hypertension.

The effects of somatostatin on plasma renin activity (PRA) and blood pressure were evaluated in patients with essential hypertension (EH) and in normotensive subjects. All subjects examined were hospitalized and placed on a diet containing 7-8 g/day sodium chloride and received an intravenous infusion of somatostatin (500 microgram/20 ml of saline, for 60 min) in the basal condition. During somatostatin infusion, the mean blood pressure (MBP) remained unaffected in all patients with EH and the normotensive subjects, while the PRA decreased slightly in the EH group. When the patients with EH were classified according to their renin levels (low, normal and high), parallel significant decreases in MBP and PRA were found only in the high renin group during the somatostatin infusion. No significant change in MBP and PRA was observed in the other groups including the normotensive subjects. To assess the activity of synthetic somatostatin, the plasma levels of growth hormone (GH) and cyclic AMP were measured. These levels were lowered significantly during the infusion and the GH levels showed a rebound 15 min after cessation of the infusion. The cyclic AMP returned to the basal levels, but no rebound was observed. The above data indicate that the fall in blood pressure in the high renin group in the basal condition was probably due in part to reduced renin release by somatostatin, and the maintenance of high blood pressure especially in high renin EH.

Adult↗