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Biomedical subjects

E Barabas

Publications and source records attributed to E Barabas.

24 records · Page 2Linked to original sources
PubMedDate not supplied

Calcitonin secretion in thyroid insufficiency.

The level of circulating calcitonin was followed up in 30 patients with severe hypothyroidism, diagnosed clinically and by laboratory examinations. Four of the patients under study had goiter. The complex investigation of phosphorus-calcium metabolism, including radioimmunoassay of calcitonin was made under basal conditions and after calcium loading. The results revealed low basal urinary calcium excretion and an increased skeletal uptake of calcium after loading. Calcitonin secretion persisted in 8 of the patients under basal conditions and it increased after calcium loading in another 14 of them, accounting for the increased "skeletal avidity" for calcium. The persistence of calcitonin secretion supports an earlier clinical observation concerning the relative integrity of the skeleton in patients with hypothyroidism. In the hypothyroid patients with goiter the results do not differ from those obtained in the remaining patients.

Adult↗
PubMedDate not supplied

45Ca uptake in tooth germs: effects of parathormone, calcitonin and propranolol.

Tooth germs harvested from 6-day-old rats were incubated in a 45Ca-containing medium for 6 hours. The addition of PTH consistently stimulated the increase in 45Ca uptake, while calcitonin significantly reduced both the PTH-stimulated incorporation and the spontaneous one. Dibutyrul CAMP (3.5 mM) had no effects. Propranolol significantly inhibited the spontaneous and stimulated 45Ca uptake. Results obtained support the concept that the two hormones have a clear influence on calcium entering the tooth germs in full calcification process probably by early membrane effect.

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PubMedDate not supplied

Calcitonin secretion in chronic renal patients treated with hemodialysis.

Calcitonin levels were studied in 18 patients with chronic renal insufficiency periodically hemodialysed, comparatively with 9 only drug-treated uremic patients. Calcitonin was radioimmunologically assayed before and after hemodialysis and repeated 5 months later in some of the patients. Serum calcitonin was increased in most of the studied patients, especially in the dialysed ones and with a creatinine clearance below 10 ml/min. Calcitonin concentration was all the more increased as the dialytic treatment lasted longer. Considering the increasing role of calcitonin as osteoprotector, these findings might be of interest in the treatment of renal osteopathy.

Adult↗
PubMedDate not supplied

Peculiarities of diabetes in patients with hyperthyroidism.

The authors report on 5 patients aged 25 to 63, with hyperthyroidism confirmed by high and plateau radioiodine uptake curves, protein-bound iodine of more than 7.4 micrograms/dl and low values of TSH (0.95 +/- 0.7 microU/ml). The fasting blood sugar was 157.6 mg% +/- 41 on average. Glycosuria ranged from 3.8 to 20.7 g/24 h and had a mean of 11 g 8.8 g/24 h. Determination of serum immunoreactive insulin (IRI) revealed very variable values: in one patient it was nondetectable, in 3 patients it had normal values, and in one patient it exceeded 41 microU/ml. These data confirm the authors' earlier reports on the variability of the glycoregulating mechanisms in hyperthyroidism, ranging from diabetes mellitusto hyperinsulinic reaction. However, most of the patients had normal IRI and reduced tolerance to glucose. The latter is probably due to the excess of thyroid hormones.

Adult↗
PubMedDate not supplied

The renin-angiotensin system and the effect of propranolol upon the cerebral cortical and hypothalamic circulation in hypoxia.

The regulatory mechanisms of the cerebral blood flow have preoccupied the physiology department of Cluj since the end of the 4th decade. These studies continued over the last years. The researches progressed from the studies of regulation by blood pressure changes to the nervous regulation and to the metabolic one. This paper's subject is the renin-angiotensin and adrenalin system influence on the changes of cerebral blood flow during the general hypoxic hypoxia and cephalic ischemia. Experiments were performed in 10 dogs anaesthetised with a mixture of chloralose, urethan and morphine. Hypoxic hypoxia was obtained by breathing a mixture of 11% oxygen in nitrogen, in a closed system and cerebral ischemic hypoxia by partial compression of the carotid arteries, after the ligation of the vertebral and thyroid arteries. The arterial blood pressure and the cerebral and hypothalamic blood flow, measured with the heated thermoelement, were registered. The plasma renin activity was tested radioimmunologically before, at 1.5 min, 5, 10 and 15 min, after the beginning of hypoxia. In ischemic hypoxia the experiment was repeated after venous perfusion with propranolol (0.6 mg/kg/h). The systemic blood pressure increased in both forms of hypoxia. The cortical and hypothalamic blood flow increased with the systemic arterial blood pressure. The hypothalamic blood flow remained stable or diminished a little. Propranolol increased the cerebral blood flow during ischemic hypoxia up to 300%. The i.v. administration of angiotensin (1-5 mg/kg) increased the cortical flow, while the hypothalamic flow remained self-regulated. Plasma renin activity increased more in general hypoxic hypoxia, than in cephalic ischemic hypoxia. After propranolol the increase was higher in this hypoxia. Propranolol produced a major activation of the renin-angiotensin system and of the cortical blood flow in ischemic cephalic hypoxia, the renin-angiotensin system being located in the cerebral structure. As well high doses of angiotensin produced cerebral vasodilatation in small cerebral vessels. This effect was found in our experiments in the cortical blood flow too. Our results indicate a beneficial propranolol effect on cortical circulation in ischemic hypoxia.

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