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Biomedical subjects

H Landau

Publications and source records attributed to H Landau.

68 records · Page 4Linked to original sources
PubMed1978

Gonadotrophin, thyrotrophin and prolactin reserve in beta thalassaemia.

Gonadotrophin (Gn), thyrotrophin (TSH) and prolactin (PRL) reserve was evaluated in patients (aged 12-26 years old) with beta thalassaemia. Abnormalities were detected in Gn reserve only. When compared with young adult controls, three of the four female patients and one of the two adult males had markedly impaired Gn responses to LH-releasing hormone (LHRH). Of the five prepubertal males, one had no Gn rise following LHRH, while responses in the other four patients were comparable to those in boys with delayed puberty. Only one adult male had an exaggerated LH response to LHRH. TSH and PRL dynamics were normal. No correlation could be found between the severity of the disturbance in the gonadal axis and the total number of blood transfusions. Our findings correlate best with the severity of the disease process itself.

Adolescent↗
PubMed1978

11 beta-Hydroxydehydroepiandrosterone in a case of virilizing adrenal adenoma: isolation from urine and mitochondrial conversion from dehydroepiandrosterone.

11 beta-Hydroxydehydroepiandrosterone has been isolated from the urine of a 14-yr-old girl with a virilizing adrenal adenoma. Its excretion was estimated to be 0.4 mg/24 h by gas chromatography and the compound was further identified by mass spectrometry. When [7-3H]dehydroepiandrosterone was incubated with mitochondria prepared from the adenoma, approximately 10% was converted to 11 beta-hydroxydehydroepiandrosterone. The identity of the radioactive 11 beta-hydroxydehydroepiandrosterone was verified by reversed isotopic dilution, its conversion to 11 beta-hydroxyandrostenedione, and its mobility in several chromatographic systems. This is the first demonstration of an 11 beta-hydroxylase from a human source having an affinity for dehydroepiandrosterone.

Adenoma↗
PubMed1978

Pituitary insufficiency following head injury.

A 32-year-old man developed panhypopituitarism and diabetes insipidus shortly after sustaining a head injury. Hormonal investigation showed that basal prolactin levels were moderately elevated the first two years after the accident, but later returned to normal. There was no rise in prolactin after administration on chlorpromazine, and the response to thyrotropin-releasing hormone was attenuated. Basal luteinizing hormone and follicle-stimulating hormone levels were low and there was no change after administration of luteinizing-hormone-releasing hormone. There was also no growth hormone elevation following arginine infusion. On the other hand, there was a normal but delayed elevation of thyrotropin in response to thyrotropin-releasing hormone. Appropriate stimulation tests showed normal responsiveness of the thyroid, adrenals and testes. These findings are compatible with an injury to the pituitary stalk, damaging the neurohypophyseal tract and affecting the blood supply to the pituitary gland.

Adolescent↗
PubMed1977

Diminished prolactin reserve: a case report.

A 17 year old male patient presented with short stature and delayed puberty. Investigations showed normal thyroid function and intact TSH response to TSH-releasing hormone (TRH). Although basal levels of LH were low, both LH and FSH rose following the administration of LH-releasing hormone (LHRH). ACTH secretion assessed indirectly by the cortisol response to insulin hypoglycemia was normal. Growth hormone levels increased following the onset of sleep, as well as after the administration of insulin, L-dopa and L-arginine. Basal levels of prolactin were low (2-5 ng/ml) compared with 5-12 ng/ml in controls. There was a markedly impaired prolactin response to TRH (maximum rise above basal values of 3 ng/ml compared to a rise of 12-29 ng/ml in controls). Prolactin levels did not rise after the administration of chlorpromazine or L-arginine. There was some suppression of prolactin levels after L-dopa. Similar patterns of prolactin are seen in panhypopituitarism, where they are usually associated with other hypophyseal hormonal deficiencies. The diminished prolactin reserve demonstrated in this subject in the presence of intact function of the remainder of the anterior pituitary is compatible with the diagnosis of diminished prolactin reserve.

Adolescent↗
PubMed1977

Salt conservation in familial dysautonomia (Riley-Day syndrome).

In some patients with familial dysautonimia, plasma renin activity shows a paradoxical response to postural stimuli, i.e., levels of plasma renin activity are high when the patient is in the supine position and fall significantly during subsequent ambulation. Furthermore, there is no coordinated release of plasma renin activity and aldosterone. The aim of the present study was to determine whether these findings are accompanied by a disturbance of salt conservation. Six patients were studied in a summer camp while on normal and low-salt diets. Plasma and urinary aldosterone levels rose sharply and appropriately when four of the patients were placed on a low-sodium diet. In these subjects, urinary sodium output fell sharply although three of them failed to attain sodium equilibrium by the third day of the low-sodium regimen. Elevation of early morning plasma renin activity appeared to correlate with an inversion in the normal day-night rhythm in urinary volume.

Adolescent↗