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Biomedical subjects

M Pedrazzoni

Publications and source records attributed to M Pedrazzoni.

At least 55 records · Page 3Linked to original sources
PubMed1989

Spontaneous release of interleukin-1 (IL-1) from medullary mononuclear cells of pagetic subjects.

The Authors examined interleukin 1 (IL-1) secretion from the peripheral and medullary mononuclear cells, obtained with sequential separation on Ficoll-Hypaque and 45% Percoll gradient, in 6 pagetic subjects and 6 normal controls. Both peripheral and medullary cells from pagetic subjects showed a significantly greater IL-1 production after stimulation with lipopolysaccharides (LPS); moreover, we observed a spontaneous IL-1 release from medullary cells in pagetic subjects but not in normal controls. These findings suggest a possible role of IL-1 in the elevated bone turnover of Paget's disease of bone.

Aged↗
PubMed1989

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↗
PubMed1989

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↗
PubMed1989

The comparative effect of ovarian hormone administration on bone mineral status in oophorectomized rats.

The effect of oophorectomy and hormone replacement therapy on cortical and trabecular bone mass was assessed in Sprague-Dawley rats. Bone mineral density (BMD) of the femur and the lumbar spine was determined by dual photon absorptiometry 4 months after surgery. Femoral mineral content was also determined. A significant decrease in bone density and in calcium content was observed after surgical castration. Bone mineral loss was prevented by either progesterone or estrogen, while the combination of progesterone and estrogen had no effect on the bone mineral content. The present study suggests the possibility that estrogen-progestin treatment may be less effective than a therapy with estrogen alone, and that further study on the effect of progesterone alone would be worthwhile.

Animals↗
PubMed1989

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↗
PubMed1988

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↗
PubMed1987

[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↗
PubMed1987

Impaired calcitonin secretion following stimulation in spasmophilic women.

Calcitonin (CT) secretion following stimulation was studied in 9 young women suffering from spasmophilia, this having been diagnosed by clinical and electromyographic criteria. The controls were 9 women, matched by age, who responded negatively to the diagnostic tests. After rapid intravenous infusion (60 sec) of 4 mg/kg/lean body mass of calcium (as gluconate), CT concentration increased measurably (p less than 0.0001) in the controls, while remaining unchanged in the spasmophilic. The average increase per cent vs. the baseline values was 225% in the controls and 34% in those with spasmophilia (p less than 0.005). 5 out of 9 of the patients showed a completely flat curve. This finding, due to a diminished CT reserve in spasmophilia, may be considered a possible diagnostic feature as well as a fundamental pathological element in the reduction of the intracellular calcium pool responsible for the neuromuscular hyperexcitability. Moreover, the therapeutic use of the hormone in this condition is to be encouraged.

Adult↗
PubMed1986

The pathophysiology of calcitonin in man.

It is generally accepted that calcitonin (CT) induces a decrement in cytosolic Ca++, and an increase of cAMP in target cells of several organs and tissues. This happens particularly in bone, where osteoclast activity and size decreases, along with the widely-known hypocalcaemic and hypophosphoraemic effect of the hormone. The physiological role of CT appears to be of importance in pregnancy and perhaps in infancy, when it antagonizes possible excessive bone loss. Some experimental evidence shows that CT may be involved in the maintenance of post-meal calcaemia. It is not yet established whether paucity of CT plays any important role in the pathogenesis of pathological conditions such as post-menopausal and senile osteoporosis.

Adult↗
PubMed1985

[Noninvasive study of the bone using single- and dual-photon densitometry: effects of age and menopause on bone density of normal and osteoporotic female population].

The assessment of bone status is so far usually performed by means of the relatively simple methods of radiographs and radiogrammetry, which are not always able to give a correct information about bone mineral content (B.M.C.) especially in cases of cortical osteoporosis. Among the other non-invasive methods, single- and dual-photon absorptiometry are of particular interest for their relatively low cost, precision, accuracy and repetitibility, giving the patient a very slight dose of radioactivity. Dual-photon device, in particular, offers the possibility to investigate B.M.C. in the bones surrounded with large amount of tissue, even in obese people. To assess bone status of feminine population, we have analyzed 238 patients, divided into 3 groups (normal pre- and post-menopausal women, and osteoporotic) measuring their radius and lumbar spine B.M.C. with single- and dual-photon absorptiometry. As a result, B.M.C. of both measuring sites appears closely correlated with age, and with the duration of menopause. In our group, cortical bone density showed a postmenopausal rate of loss higher than the trabecular. Vertebral measurements, too, were more closely correlated with age when corrected for body surface area. Osteoporotic group showed a B.M.C. significantly lower than the age-matched group of normal women both in spine and in radius: in conclusion, all these findings stress the importance of a widespread population surveillance in order to individuate and treat the patients at risk of spontaneous fractures.

Adolescent↗