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Biomedical subjects

G C Isaia

Publications and source records attributed to G C Isaia.

At least 55 records · Page 3Linked to original sources
PubMed1985

Effect of naloxone on gonadotropin secretion before and after testosterone in Klinefelter's syndrome.

A study was performed on eight subjects with Klinefelter's syndrome to assess the relation between gonadal hormones and opioid inhibition of gonadotropin secretion through comparison of their gonadotropin response to naloxone (NAL) (0.3 mg/kg; 1/3 bolus iv. at time 0 and 2/3 iv. for 120 min) before and after testosterone propionate (TP) 100 mg/day im. for 5 days. Under basal conditions, NAL failed to induce a significant change in LH levels. After TP, however, despite unchanged basal LH levels (mean +/- S.E.M.: 27.0 +/- 3.4 vs 21.2 +/- 3.21 microU/ml), LH significantly increased in response to NAL. FSH did not respond to NAL either before or after TP administration, though FSH levels were significantly reduced by TP. These findings suggest that in man, as in animals, gonadal hormones regulate opioid inhibition of LH secretion. The negative feedback of testosterone and its ability to activate opioid inhibiting tone may be dissociated, in keeping with the view that gonadal hormones control gonadotropin secretion through the activation of distinct, albeit concomitant, mechanisms.

Adolescent↗
PubMed1983

Effects of naloxone on the insulin and GH responses to alpha-adrenergic stimulation with clonidine.

To find if endorphins can influence hormonal responses mediated by noradrenergic pathways, we examined the effects of naloxone, an opiate receptor blocker, on the GH and insulin responses to clonidine, a drug which acts by stimulation of alpha-adrenergic receptors. Intravenous clonidine (0.15 mg in 10 min) induced a significant fall of plasma insulin and a marked increase of plasma GH. Intravenous naloxone (bolus of 1.6 mg followed by 50 micrograms/min) did not change the insulin response to clonidine, and seemed to induce only a slight delay in the GH response.

Adrenergic alpha-Agonists↗
PubMed1978

[Use of releasing hormones in endocrinological diagnosis].

The identification and synthesis of thyrotrophin-releasing hormone (TRH) and luteinising hormone releasing hormone (LHRH) has widened our knowledge of hypothalamo-hypophyseal-thyroid and hypothalamo-hypophyseal-gonad diseases. More precisely, administration of these two releasing factors, by permitting the evaluation of pituitary TSH, LH, and FSH reserves, reveals otherwise undefinable changes in hypophyseal function. An account of the manner of execution and measurement, the administration route, and side-effects related to TRH and LHRH tests is followed by a description of the main diseases in which they offer the greatest degree of diagnostic assistance.

Acromegaly↗
PubMed1977

[A case of primary hyperparathyroidism sustained by parathyroid adenocarcinomatosis].

Primary hyperparathyroidism may at times be associated with carcinoma of the parathyroids. A personal case of primary hyperparathyroidism was operated on by total thyro-parathyroidectomy. The histological picture presented atypical cell patterns and infiltrations of the thyroid capsule, together with adenomatuous parathyroid formations suggesting the possibility of a malignant transformation of initially benign process. Given the benign clinical course, it is possible that when subjected to radical, timely measures, even atypical parathyroid processes may be cured completely.

Adenocarcinoma↗
PubMed1975

[Hyperparathyroidism in pregnancy].

A case of adenoma-based hyperparathyroidism operated at the 4th month of pregnancy (third reported case) is described. The clinical picture was extremely flimsy and diagnosis was formulated exclusively on the observation of the characteristic alterations in the calcium-phosphorus metabolism. The validity of examining renal phosphate excretion for the diagnosis of hyperparathyroidism is considered and proposed evaluation indices (P.E.I. of Nordin and Fraser; I.P.E. OF Nordin and Bulusu) are discussed. The gravity of foetal prognosis in hyperparathyroid women is sufficient justification for surgery during pregnancy.

Adenoma↗
PubMedDate not supplied

High density lipoproteins (HDL) in women with postmenopausal osteoporosis: a preliminary study.

OBJECTIVE: Since a previous study showed an inverse correlation between high density lipoproteins (HDL) and bone mineral density (BMD), we searched for a possible relationship between HDL level and the presence of postmenopausal osteoporosis. DESIGN: We measured HDL levels in 37 women with postmenopausal osteoporosis, and compared them with a control group of 43 healthy postmenopausal women. The HDL levels were compared between the two groups using Student's t test and were correlated with BMD by Pearson's coefficient. To avoid possible selection bias, we compared patients and controls for body mass index by chi 2 test. The sensitivity and specificity of HDL level higher than 65 mg% (positive test) or lower than 45 mg% (negative test) was compared with double emission x-ray absorptiometry (considered the gold standard in the measurement of BMD). RESULTS: The level of HDL was significantly higher in the osteoporotic patients than in the controls (67.7 +/- 15.5 mg% vs 58.3 +/- 11.6 mg%, p = 0.0039). HDL was inversely correlated with BMD (r = -0.29, p = 0.0083). HDL higher than 65 mg% has a high specificity (77%) for patients with osteoporosis, while HDL lower than 45 mg% has a high sensitivity (97%) in detecting subject without osteoporosis. CONCLUSIONS: Our preliminary data suggest an interesting, as yet unexplained association between HDL and bone mineral density in postmenopausal women.

Absorptiometry, Photon↗
PubMedDate not supplied

Plasma levels of testosterone, LH and FSH after prostatic adenomectomy.

Changes in blood testosterone, LH and FSH induced by the surgical management of BPH were studied. It is felt that the observation of depressed testosterone and enhanced LH mean levels one year after surgery, substantiates a previously advanced personal view that hyperplastic nodules are heavy consumers of testosterone.

Aged↗
PubMedDate not supplied

Bone mineral density in the growing human mandible.

The objective of this study was to investigate bone mineral density (BMD) in the growing human mandible by dual-energy X-ray absorptiometry, comparing densitometric data with the nature of the dentition and hence, indirectly, with variation of mechanical stresses. Postero-anterior scans were performed on 58 dried mandibles (between 15 months and 14 years) by a Hologic QDR 1000 X-ray densitometer with "Ultra-Hi-Resolution" software (Hologic Inc., Waltham, MA). The analyses were performed on a polygonal area corresponding to the infero-median region of the mandibular body, and divided into three sections. The sample was divided into two groups according to the appearance of the first permanent molar. A high correlation is detectable between BMD values and age in the group with decidual dentition, while BMD values are significantly less correlated with age in the group with mixed dentition. There are no significant differences between the BMD values of males and females.

Adolescent↗
PubMedDate not supplied

[Gamma-ray bone densitometry and evaluation of the patient at risk for osteoporosis].

After having briefly illustrated the main theories of photonic ray bone densitometry, the authors describe the various techniques used to evaluate bone mass and bone mineral density as accurately and precisely as possible both at an appendicular level and at lumbar and femoral sites. Since these data only provide a static measurement and are unable to provide information regarding bone mass evolution in time, a method is illustrated which is theoretically capable of identifying high risk subjects, namely those who, on the basis of simple blood and urine tests for some biochemical parameters, are likely to undergo a significant reduction in bone mass in the future. Lastly, the paper reports the preliminary results of a study carried out in immediately post-menopausal women in whom rapid loss of bone mass was followed by a greater reduction in bone mineral density measured at an appendicular level.

Absorptiometry, Photon↗
PubMedDate not supplied

[Postmenopausal and senile osteoporosis. Prevention or therapy?].

Pharmacological treatments of osteoporosis can improve bone mineral content, but are not able to restore trabecular bone structure in presence of microfractures. It is therefore necessary to carry out at the right moment some preventive actions to increase peak bone mass in premenopausal age: adequate calcium intake, systematic physical activity and, if necessary, oestrogen administration before menopause are correct prophylactic measures against osteoporosis; moreover risk factors identification allows to perform a preliminary screening. Serial bone absorptiometry at lumbar level is able to identify fast losers women by means of integrating densitometric data and some metabolic results. Utilizing these methods it is possible to activate proper preventive or therapeutic measures and prevent osteoporotic complications.

Absorptiometry, Photon↗
PubMedDate not supplied

[Photon densitometry in the diagnosis of osteoporosis].

The increased average life expectancy of the inhabitants of industrialised countries has led to a marked increase in degenerative pathologies, including osteoporosis. This has made it necessary to elaborate instrumental tests capable of identifying risk subjects in order to intervene as quickly as possible using appropriate prophylactic and therapeutic measures. Single and dual photon ray densitometry represents the first correct approach to quantitatively assess bone mineral content. It not only allows an early diagnosis to be made but also enables a longitudinal study to be made of patients receiving treatment. The main studies on the accuracy and precision of dual photon ray densitometry are reported together with the authors' findings regarding the definition of the fracture threshold and osteoporosis caused by metabolic and endocrinological disorders.

Absorptiometry, Photon↗
PubMedDate not supplied

[Comparison of MR and CT in a radiological study of Cushing's syndrome. A report on 16 cases].

In 16 patients with high cortisol plasma levels MRI and CT investigation of adrenal gland region was performed; 13 also had the pituitary region examined. CT and MRI results in Cushing's Syndrome due to adrenal glands etiology (8 cases) are overlapping. The morphological criteria utilized consist in the radiological finding of bilateral adrenal hyperplasia or adrenal mass (adenoma, carcinoma). The great amount of retroperitoneal fat increases the normal contrast with both techniques. In the pituitary Cushing's Syndrome MRI was more sensible than CT as far as it concerns ACTH producing pituitary lesion assessment; this technique may show 5 mm diameter adenomas for their high signal intensity.

Adenoma↗