PubMed Health⌕ Search

Biomedical subjects

G Pioli

Publications and source records attributed to G Pioli.

At least 37 records · Page 2Linked to original sources

Meal-stimulated gastrin release and calcitonin secretion.

In order to study the effects of a physiologic meal on calcitonin (CT) secretion we studied 6 normal male volunteers (aged 28-34 yr). Each subject was given, on two separate days, either a mixed meal or 200 ml of distilled water, in random order. Gastrin (G) was effectively stimulated by the meal (F = 8.82; p less than 0.001) and reached a peak (with an average 100% increase) 30 min after the end of the meal, slowly decreasing thereafter; no increase was seen after water ingestion. On the other hand, CT levels remained stable throughout the observation period on both occasions. Ionized and total calcium did not show significant variations either after the meal or after water ingestion. These findings suggest that G alone, at the concentrations usually reached after a physiologic meal, is unable to stimulate CT secretion, at least in the absence of calcium increases.

Adult↗

Short-term effects on bone and mineral metabolism of 4-amino-1-hydroxybutylidene-1,1-diphosphonate (ABDP) in Paget's disease of bone.

To study the short-term effects on mineral and bone metabolism of a recently introduced amino-diphosphonate (4-amino-1-hydroxybutylidene-1,1-diphosphonate or ABDP), 10 patients suffering from active Paget's disease were examined. Each subject received intravenously 5 mg/day of ABDP for 4 days and the effects of treatment were monitored for 12 days. ABDP administration was followed by an early and significant decrease of the urinary hydroxyproline and calcium excretion, of the theoretical renal threshold for phosphate of the serum calcium. Serum phosphate also decreased, while its urinary excretion increased. Intact parathyroid hormone levels at the end of treatment were four times higher than basal levels. Total and bone alkaline phosphatase tended to decrease only slightly at the end of the observation, whereas serum osteocalcin, tended to increase. These findings indicate that the earlier effect of ABDP is a profound inhibition of bone resorption, which brings about a compensatory parathyroid hormone response. The decrease of urinary hydroxyproline follows an exponential curve, with a calculated half-life of 2.2 days, suggesting an approximate equivalency of 5 mg/day ABDP to slightly more than 30 mg/day 3-amino-1-hydroxypropylidene-1,1-diphosphonate. Bone formation seems scarcely influenced in the short-term, but osteoblastic indices show a contrasting behaviour, which may reflect a different biological origin and/or significance.

Adult↗

Impaired ACTH and beta-endorphin response to sauna-induced hyperthermia in heroin addicts.

To evaluate the responses of circulating beta-endorphin, met-enkephalin and ACTH to sauna-induced hyperthermia, 8 male heroin addicts recently admitted to a therapeutic community and 8 age-matched normal subjects were examined. Compared with control subjects, heroin addicts showed 1. A decrease of the basal levels of beta-endorphin; 2. Absence of the normal increase of beta-endorphin and ACTH after sauna; 3. A lower increase in systolic blood pressure. It is concluded that an impairment of the adaptive response to stress may be present in heroin addicts, even after a relatively short drug-free period (14 days).

Adolescent↗

Metergoline, naloxone, and sodium valproate did not modify arginine vasopressin response to insulin-induced hypoglycemia in man.

The present study was carried out in order to determine whether insulin-induced hypoglycemia exerts its stimulatory effect on plasma concentrations of arginine vasopressin (AVP) by interacting with a serotonergic, a GABA-ergic or an opioid pathway. For this purpose, the effect of the serotonergic antagonist metergoline (10 mg/day for 4 days po), the GABA-ergic agonist sodium valproate (600 mg in three divided doses po) and the opioid-receptor blocker naloxone (10 mg in a iv bolus) on the AVP response during an insulin (0.15 IU/kg bw) tolerance test (ITT) was evaluated in three groups of 6 normal men each. In all men, control ITTs were performed without drug treatments. Basal and ITT-stimulated AVP secretion was not modified by drug administration, suggesting that serotonergic, GABAergic and naloxone-sensitive opioid receptors are not involved in the regulation of AVP secretion in response to insulin-induced hypoglycemia.

Adrenocorticotropic Hormone↗

Calcitonin levels in normal women of various ages evaluated with a new sensitive radioimmunoassay.

In order to establish the normal range of serum Calcitonin (CT), evaluated with a new, sensitive radioimmunoassay in normal women of various ages, 67 female subjects were examined. CT levels were detectable in all the subjects, with a reference interval (bounded by the 2.5 and 97.5 percentiles) of 3.6-16.9 pg/ml; a very slight decrease with age was observed (correlation coefficient = -0.24; P = 0.05; regression equation: CT = 9.55--0.042 x age). This assay seems sensitive enough to permit the measurement of CT in physiological conditions.

Adult↗

[Changes in bone mass with age. Transversal study on a female population using photon densitometry].

In order to evaluate the age-related changes of the bone mineral content (BMC), 281 clinically healthy women (20-80 year old) underwent single photon abosorptiometry (SPA) on the distal third of the radius (where there is a prevalence of cortical bone); 161 subjects of this group were examined also by dual photon absorptiometry (DPA) of the lumbar tract of the spine (L2-L4) (trabecular bone). The relationship of trabecular BMC with age is described by a cubic polynomial regression (r = 0.46; p less than 0.0001) that shows an increase in BMC until 31 years of age followed by a decrease with a minimum at the age of 78; afterwards trabecular BMC adds an apparent increase. No increase in the rate of trabecular BMC loss was seen after the menopause. A positive correlation was found between body weight and vertebral BMC. The behaviour of cortical BMC with age is described by a quadratic regression (r = 0.42; p less than 0.0001) that shows an increase until 32 years of age followed by a decrease. Cortical BMC shows a significant decrease after menopause. No correlation was found between body weight and cortical BMC. These findings underline the different behaviour of trabecular and cortical bone tissue with age; in addition, the relation between trabecular (but not cortical) BMC and body weight argues for an important role of biomechanical factors in the local modulation of bone mass.

Adult↗

[Sequential calcitriol-calcitonin in the therapy of osteoporosis].

Different therapeutic regimens have been proposed by Authors in the treatment of involutional (and particularly postmenopausal) osteoporosis. Following the up to date concepts on bone remodelling, an ADFR (Activate, Depress, Free, Repeat) trial was performed in 20 females affected by involutional osteoporosis. They were treated with Calcitriol 2 mcg/d for 7 days, followed by a 21 days period of 100 U/d Salmon Calcitonin + 1 g/d Calcitonin, followed by a 2-month period of Calcium alone. The cycles were repeated for 1 year and the results of densitometric examinations (radial mineral content evaluated by single photon absorptiometer, and vertebral mineral content evaluated by dual photon absorptiometer) and of biochemical markers (Ca++, P, osteocalcin, alkaline phosphatase, hydroxyproline) controlled every 3 months, were compared with those obtained in a group of patients treated only with Salmon Calcitonin and in a group treated with Calcium for 1 year. After two therapeutical cycles radial bone mineral density significantly increased; vertebral bone density also increased but not significantly. The effects were more evident in comparison to calcitonin alone treatment. A significant reduction in serum osteocalcin was documented. At the end of the therapy no further improvement was registered. This suggests that some variations and adaptation of therapeutic strategy are needed to achieve a more important and substantial improvement of bone conditions.

Administration, Oral↗