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Biomedical subjects

B Di Natale

Publications and source records attributed to B Di Natale.

At least 19 recordsLinked to original sources

Vasopressin and thirst in patients with posterior pituitary ectopia and hypopituitarism.

OBJECTIVE: Partial diabetes insipidus has been documented in patients with congenital hypopituitarism and posterior pituitary ectopia, some cases being clinically silent except for enuresis. The objective of our study was to evaluate vasopressin (AVP) secretion and thirst appreciation in hypopituitary patients with posterior pituitary ectopia. PATIENTS: Twelve males and three females, aged between 13 and 38 years (median 19 years). Eleven had multiple pituitary deficiencies, adequately replaced at the time of the study, and four were only growth hormone deficient. None of the patients suffered from polyuria, polydipsia or nocturnal enuresis. We tested the patients with a 5% NaCl infusion. Five patients with abnormal vasopressin production were also tested with nitroprusside, which affects baroceptor vasopressin secretion. RESULTS: We found that only two out of 12 patients had normal AVP secretion. Thirst assessment showed severe hypodipsia in one patient, hyperdipsia in three out of 15 and more subtle abnormalities in two out of 15 patients. Concordance was found between osmotically and baroceptor-stimulated vasopressin. CONCLUSIONS: Patients with posterior pituitary ectopia showed a high prevalence of subclinical subnormal vasopressin response to the osmolar stimulus and moreover an impairment of thirst appreciation. Our data on nonosmotically stimulated AVP release suggest the existence of a damage in the hypothalamic vasopressin secreting centres.

Adolescent↗

[New perspectives on the treatment of growth hormone deficiency].

In the last few years the therapeutic management of GHD children has been improved by the recent synthesis of GH by DNA recombinant technique (rGH). rGH made it possible to overcome the problems of availability and purity of extractive GH, obtaining the same results (in growth velocity) without any information as regards late side effects of such a treatment. GHRH therapy in GHD patients of hypothalamic origin is still on trial and a lot of aspects are to be pointed out (indications to treatment, schedule and route of administration, cost/benefit ration, side effects).

Biotechnology↗

[Induced hypoglycemia. A unusual case of child battering].

We describe a case of Munchausen's syndrome by proxy in a 12 years old child. The administration of glibenclamide by the mother led to severe hypoglycemias in the child, who underwent various instrumental researches and a subtotal pancreatectomy before the final diagnosis could be reached. The diagnosis also was possible with the substantial help of an accurate psychological survey. The case solution, with disappearance of hypoglycemias, was made possible by the removal of the maternal presence settled by the juvenile court.

Child↗

Correlation of gonadal function with histology of testicular biopsies at treatment discontinuation in childhood acute leukemia.

Testicular open-wedge biopsy was performed in 35 children in complete remission from acute lymphoblastic leukemia without clinical signs of leukemic testicular infiltration at the time of treatment discontinuation. Histological investigation showed thickening of the tunica propria of the seminiferous tubules in 13 of 35 patients. In 5 of 35 patients, the tubular fertility index was markedly reduced; in 5 of 6 pubertal patients, decreased spermatogenesis or aplasia of germinal epithelium was observed. Histologic damage was found mainly in the germinal cells both in patients treated with cytosine arabinoside and cyclophosphamide and in those treated with antiblastic drugs not considered damaging to the gonads. The extent of impairment was independent of age at start of treatment. On the other hand, endocrinological investigation carried out at the crucial moment of treatment suspension showed normal hypothalamic-hypophyseal-gonadal function as well as normal anthropometric data, bone age, and pubertal stage in the majority of patients. Testicular leukemia was found in only one patient (2.8%) whereas three children with negative testicular biopsies had testicular relapses within 7 months. Therefore, in view of the limits of light microscopy in diagnosing leukemic infiltration at treatment discontinuation, we propose the use of more sophisticated techniques, possibly within 6 months of suspension of therapy.

Adolescent↗

Familial XX true hermaphroditism and the H-Y antigen.

Two 46,XX sibs, one of female, one of male gender, and both with ambiguous external genitalia and ovotestis, were H-Y positive. The mother was H-Y negative. It is assumed that the underlying mutation was transmitted by the father, resulting in an autosomal dominant mode of inheritance. The common origin and the nature of the mutation leading to XX sex reversal are discussed.

Adolescent↗

Glucagon response to arginine stimulation in obese and diabetic children.

The effect of arginine infusion on blood sugar and plasma levels of growth hormone and glucagon has been studied in children with clinical diabetes mellitus and in obese children with normal carbohydrate tolerance. Basal levels of plasma GH are significantly lower in obese children than in diabetics and controls; in obese subjects the increment of GH is significantly lower than in diabetics and controls. Basal plasma glucagon levels are comparable in all three groups despite the high sugar levels in diabetic patients. After arginine infusion there is a significant rise in glucagon levels without significant differences between the three groups.

Adolescent↗

Muscular exertion: a test of pituitary function in children.

The elevated level of growth hormone after moderate standardized physical exercise was compared with that induced by intravenous arginine infusion and by insulin induced hypoglycemia in children with normal pituitary function. Tests were performed on 49 prepubertal children (34 boys and 15 girls); in 42 cases the increase was significant for all three tests, in 5 cases the response was minimal after insulin stimulation but normal after arginine and physical exertion; in 1 case arginine produced no response but the other tests were positive; in 1 case there was a response to arginine but none to insulin or physical exertion. The results indicate that frequently more than one test is necessary for the diagnosis of normal pituitary function; physical exertion being a physiologic test, is simple to perform, acceptable to the children and without side effects. It appears the test of first choice because it can be used in patients seen ambulatorily, other tests being performed in case of doubt or negative response.

Arginine↗