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Biomedical subjects

G C Isaia

Publications and source records attributed to G C Isaia.

At least 19 recordsLinked to original sources
PubMed1992

Influence of estrogens on calcitonin secretion.

In this study we investigated the calcitonin (CT) pattern both in basal conditions and after calcium infusion before and one month after oophorectomy in 17 premenopausal women. In addition, 13 oophorectomized women were randomly allocated to two groups, one given hormone replacement treatment and the other untreated, and CT response to hypercalcemia was reevaluated one year later. CT response to calcium infusion was significant only before oophorectomy and one year after estrogen-progestogen treatment, whereas there was no response one month after oophorectomy or after one year without hormone replacement therapy. Our data indicate that both estrogen secretion and replacement treatment may be important factors in CT response.

Adult↗
PubMed1992

Effects of ipriflavone on bone mass and calcium metabolism in postmenopausal osteoporosis.

Recently it has been demonstrated that ipriflavone (IP), an isoflavone derivative, is able to increase bone mass in patients with established postmenopausal osteoporosis (PMO). Here we present a preliminary report of a 2-year multicenter, double-blind, placebo-controlled clinical study performed in order to evaluate the efficacy and tolerability of IP in PMO. A large number of patients with PMO, referred to 12 Italian centers, was randomly divided into 2 groups and treated with oral IP (600 mg/day) or placebo (Pl). All patients received an oral Ca supplement (1 g/day). One hundred and twenty six patients completed 1 year of the study. Bone mineral density (BMD) of the distal radius, measured by DPA, serum osteocalcin (BGP), and urinary hydroxyproline excretion (HOP/Cr), were measured before and after 12 months. After 12 months, a significant increase in BMD was observed in the IP-treated group (P < 0.05). IP determined a reduction of HOP/Cr, while in Pl-treated patients a significant increase of this index, as well as of BGP, was observed. After 12 months the difference between the two groups resulted significant (P < 0.05) for BGP. The drug was well tolerated and the patients' compliance to the oral treatment resulted excellent. The results of this study indicate that IP is able to increase bone mass in patients with PMO.

Aged↗
PubMed1990

Vertebral bone loss in menopause.

A direct correlation between loss of ovarian function and reduction of bone mass is well established. The incidence of fractures sharply increases with age starting from the menopause. Therefore, it is very important to know the rate of bone loss occurring after menopause, at both trabecular and cortical levels. Several factors may contribute to the reduction of bone mass in menopause. Reduced estrogen secretion results in reduced intestinal calcium absorption, increased bone resorption, and probably a deficient production of calcitonin. Furthermore, in vivo and in vitro experimental data confirm that estrogen failure is associated with histologic changes, mirroring the biochemical changes described in postmenopausal osteoporosis.

Aged↗
PubMed1990

[Effect on phospho-calcium metabolism of testosterone administration in hypogonadal males].

Many authors have shown that osteoporosis is an important complication in male hypogonadism, due to the chronic lack of androgens; but in hypogonadal males the pathogenesis of osteopenia isn't completely explained. In this work we examined in 10 hypogonadal males (4 with Klinefelter's Syndrome and 6 with Hypogonadotropic Hypogonadism) lumbar bone mineral content (BMC) and the effects of testosterone (Sustanon) administration on BMC and other phosphocalcium parameters. We evidenced lower BMC levels in hypogonadal subjects if compared to those observed in the control age-matched group; moreover after 3 months of treatment a statistically significant increment of plasma bone gla protein, calcitonin and lumbar BMC was observed. On the contrary no significant variation was observed in osteoclastic indexes (PTH-MM, OHPU/CrU, CaU/CrU) after treatment. In addition both calcitonin basal levels and secretory reserve, measured with calcium infusion, were significantly increased after treatment. Our data confirm the hypothesis that androgen acts on bone principally directly at osteoblastic level, in a stimulatory manner, and indirectly, with calcitonin mediation, with inhibition of osteoclasts.

Adolescent↗
PubMed1990

Mineralometry of the lumbar spine and histomorphometry of the iliac crest: preliminary results of a comparison of several parameters in the same individual.

Twelve patients affected with various bone pathologies (osteoporosis, renal osteodystrophy, osteogenesis imperfecta, hyperparathyroidism) were submitted to mineralometry of the lumbar spine with double photonic ray and transiliac biopsy for histomorphometry. A comparison of the values obtained for the mineralometric and histomorphometric parameters--despite the small number of cases--revealed a correlation between bone mineral content of the lumbar spine and trabecular and cortical bone volume of the iliac crest. The correlation is even more significant for the sum of these last two parameters. It may be concluded that: 1) both the methods have predictive values for an evaluation of osteopenia; 2) the measurement of cortical and subcortical bone volume increases the significance of the histomorphometric finding (which is usually limited to the trabecular bone volume); 3) there is a correlation between histomorphometry (iliac crest bone volume) and mineralometry (lumbar spine with double photonic ray) in the same individual.

Absorptiometry, Photon↗
PubMed1988

Vertebral bone density in non-amenorrhoeic hyperprolactinaemic women.

Recently, a decrease in bone mineral content (BMC) in hyperprolactinaemic women with long-lasting amenorrhoea has been reported, and attributed either to a direct effect of PRL on bone or secondary to the oestrogen deficiency. To verify if PRL by itself has a direct effect on bone, we have studied BMC at the lumbar level by double-photon absorptiometry in 22 patients with hyperprolactinaemia, selected on the basis of normal or near-normal oestradiol levels. The results were compared with those obtained in 28 healthy closely-matched women, and seven hyperprolactinaemic patients with long-lasting amenorrhoea and oestrogen deficiency. No significant difference in BMC was observed between hyperprolactinaemic patients with normal oestrogen levels (mean +/- SEM = 3.87 +/- 0.10 gHA/cm) and normal subjects (mean +/- SEM = 3.76 +/- 0.10 gHA/cm). Moreover, no significant change was observed during a 6 month follow-up in 13 patients. On the other hand, a significant difference (P less than 0.05) was detected in BMC between the hyperprolactinaemic patients with normal oestradiol levels and those with long-lasting amenorrhoea and oestrogen deficiency (mean +/- SEM = 3.39 +/- 0.18). These results suggest that hyperprolactinaemia by itself is not a risk factor for the development of osteoporosis.

Adult↗
PubMed1988

[Ultrasonic evaluation of primary hyperparathyroidism].

The authors evaluated the diagnostic reliability of echotomography in detecting parathyroid masses: 37 patients were studied with primary hyperparathyroidism, in four cases recurrent. They all underwent surgical ablation of the mass, identification of all glands, and biopsy of an apparently normal parathyroid. Echotomography was accurate in 91.4% of cases: it identified 27 out of 39 pathological glands (sensibility 69.2%) and gave no false-positive results (specificity 100%). Since parathyroid is often ectopic, oblique scans are suggested, i.e. of jugulum while the patient is swallowing. Such scans were always used in our study, in order to identify lesions even in case of "difficult" locations, such as the superior mediastinum.

Adenoma↗
PubMed1988

[Recent diagnostic and therapeutic findings on postmenopausal and senile osteoporosis].

The incidence of osteoporosis in the West is considerable and its complications are such as to make it a common and disabling problem. Recent developments in the classification, pathogenesis and diagnosis of the disease are reported. Certain laboratory techniques have recently been developed that can provide adequate information about the degree of demineralisation present. Furthermore the accurate in vivo assessment of bone density is made possible by the development of double beam photon osteodensitometry that measures bone mineral content (BMC) with sensitivity and accuracy. On the treatment side, the various drugs available are reviewed with particular reference to estrogen, vitamin D, anabolisers (recently reassessed in radiogrammometric and densitometric studies) fluorides and calcitonin. Finally certain treatment protocols for post-menopausal and senile osteoporosis are proposed that should produce good results in a reasonably short space of time.

Aged↗
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↗
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↗