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Biomedical subjects

G Girasole

Publications and source records attributed to G Girasole.

47 records · Page 3Linked to original sources

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↗

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↗

Rociverine for nocturia in the elderly: medium-term controlled clinical trial.

Forty patients, aged 51 to 79 years, with nocturia due to bladder instability, resorption of postural edema, or senile decay, were treated with rociverine or flavoxate to test the possibility of reducing or eliminating nocturnal voidings. After a two-day observation period, each patient received either 20 mg of rociverine or 200 mg of flavoxate in a single dose at 8 PM. The following were assessed before the trial and after 14 and 28 days of treatment: number of night voidings, interval between drug administration and first voiding, volume of first voiding, volume of urine voided during the night, volume of morning urine, and total volume of urine passed between 8 PM and 8 AM. Routine laboratory tests performed before and after the trial showed both drugs to be well tolerated. The results of the trial show that rociverine reduced the number of night voidings significantly more (P less than 0.05) than did flavoxate.

Aged↗

[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↗

[Bisphosphonates stimulate the production of basic fibroblast growth factor and the formation of bone marrow precursors of osteoblasts. New findings about their mechanism of action].

BACKGROUND: It has been recently shown that bisphosphonates may affect bone resorption either directly on osteoclast activity or through the mediation of osteoblasts activity. In this experimental study the potential effects of etidronate and alendronate on osteoblastic bone formation are investigated. METHODS: The number of fibroblastic colony forming units (CFU-F) and mineralized nodules (CFU-OB) in murine and human bone marrow cultures, assessed. In addition, the basic-FGF production by human osteoblastic cells MG-63 measured. RESULTS: In murine bone marrow cultures etidronate and alendronate stimulate CFU-F formation with a mean increases vs control of 106 +/- 17% at 10(-5) M and 78 +/- 5% at 10(-7) M respectively (p < 0.001). The formation of bone nodules is inhibited by bisphosphonates at high concentrations (> 10(-6) M) and stimulated at lower concentrations (from 10(-7) M to 10(-9) M for etidronate and from 10(-7) M to 10(-10) M for alendronate; p < 0.001). Similarly, in human bone marrow cultures alendronate increases CFU-F formation with a maximal effect at 10(-10) M (+161 +/- 12% vs control; p < 0.01) and the formation of CFU-OB with a maximal effect at 10(-10) M (+133 +/- 34%; p < 0.001). Finally, etidronate (from 10(-9) to 10(-11) M) and alendronate (from 10(-9) to 10(-12) M) stimulate the b-FGF production by human osteoblastic cells (p < 0.01). CONCLUSIONS: In line with previous histomorphometric and clinical observations, the results obtained indicate that bisphosphonates directly affect osteoblastic cells with a positive effect on bone formation, probably via the stimulation of growth factors.

Alendronate↗

The possible role of hematin and Mössbauer effect in the inhibition of osteosarcoma cell proliferation.

Hematin, like many hematoporphyrines and porphyrin derivatives, shows a higher affinity and preferential localization for tumor cells. These properties are particularly interesting in view of their possible applications in tumor treatment. The aim of the present work was to test the capability of porphyrines and resonant low energy gamma rays to produce some kind of selective inhibition of tumor cell proliferation. We investigated the role of hematin to potentiate the killing capability of 14.4 keV resonant gamma rays from a 57Co Mössbauer source. Human osteosarcoma cell cultures "MG-63" were incubated in the presence or absence of hematin (10(-4) to 10(-5) M) for 24 hours. They were successively irradiated for 4 hours with 14.4 keV gamma rays from a 3.7 GBq 57Co source. The combined effects of hematin and resonant gamma radiation were then examined and tested statistically for significance. Different degrees of growth inhibition were observed when hematin alone, radiation alone, and hematin plus gamma rays were administered to the cultures. Hematin, at the concentrations of 10(-4) M is capable of inhibiting tumor cells growth. While no significant effect is attributable to irradiation alone, hematin plus irradiation show a larger inhibition than that expected for purely additive effects.

Cell Division↗