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Biomedical subjects

S Adami

Publications and source records attributed to S Adami.

At least 91 records · Page 5Linked to original sources
PubMed1995

Acute effects of deflazacort and prednisone on rates of mineralization and bone formation.

The aims of this study were to determine (1) whether acute suppression of bone formation could be evaluated after the administration of corticosteroids in man by quantitative bone histomorphometry; and (2) whether there were significant differences between the effects of prednisone and its analog deflazacort. Thirteen patients who needed high-dose corticosteroid therapy were randomly allocated to two groups of treatment (prednisone or deflazacort). Quantitative bone histomorphometry, using the technique of triple labeling, and biochemical measurements of bone turnover were studied. There were no differences in biochemical indices of bone turnover between prednisone and deflazacort at the beginning and end of the 15 days of treatment course. During corticosteroid treatment, there were no significant changes in biochemical indices of bone turnover but a significant decline in total alkaline phosphatase (P < 0.01). Histomorphometric indices, as revealed by measurements of tetracycline interval and extent of labeling, showed no significant differences in either mineral apposition rate or bone formation rate in the two groups. We conclude that the acute glucocorticoid suppression of bone turnover by glucocorticoids is not detectable within the first 2 weeks of treatment by histomorphometric techniques. No differences in bone effects of prednisone and deflazacort were detected in this short-term study.

Adult↗
PubMed1995

Evaluation of therapeutic efficacy in osteoporosis.

Evaluation of the efficacy of osteoporosis treatments poses a major challenge for clinical investigators. This paper addresses the question of whether increases in bone mass induced by therapy for osteoporosis are sufficient to determine the efficacy of that therapy, or whether long-term fracture endpoint studies are required. Osteoporosis has been defined as a systematic skeletal disease characterized by low bone mass and microarchitectural deterioration of bone tissue, with a consequent increase in bone fragility and susceptibility to fracture. This association between bone mass and fracture risk has been found to be stronger than other well-recognized risk factor associations, such as blood pressure and risk of stroke. Although fracture endpoint studies would provide confirmation of the benefit of osteoporosis therapy, such trials require that several thousand patients be studied for many years, making such studies impractical as a means for providing data for the approval of new therapies. Determination of increased bone mass may provide data that are just as useful in evaluating therapeutic efficacy. The use of bone mass as the primary efficacy endpoint for those therapies that are associated with normal bone quality is justified by the well-documented relationship between bone mass and fracture risk observed in several epidemiological studies.

Bone Density↗
PubMed1995

Effects of oral alendronate and intranasal salmon calcitonin on bone mass and biochemical markers of bone turnover in postmenopausal women with osteoporosis.

The main objective of this study was to determine the effect of daily oral alendronate treatment on bone mass in postmenopausal women affected by osteoporosis. The efficacy of intranasal salmon calcitonin was also examined. Nine centers in Italy enrolled 286 postmenopausal women between the ages of 48 and 76 with spinal bone mineral density > or = 2 SD below adult mean peak in the two-year, double-blind, randomized, placebo-controlled trial. Patients were randomized to one of four treatment arms: double-blind placebo, alendronate 10 mg/day, alendronate 20 mg/day, or open-label intranasal salmon calcitonin 100 IU/day; all patients received 500 mg Ca++ supplements. Bone mass was measured by dual-energy x-ray absorptiometry every six months for two years. Patients who received alendronate 10 or 20 mg experienced significant increases in bone mass at all sites measured. At the end of the second year, the mean percent changes, for alendronate 10 and 20 mg relative to placebo, were 5.2% and 7.3% at the lumbar spine, 3.8% and 4.6% at the femoral neck, and 7.1% and 7.5% at the trochanter, respectively. In contrast, intranasal salmon calcitonin failed to increase bone mineral mass significantly at any site. Both alendronate doses significantly decreased serum alkaline phosphatase, serum osteocalcin, and urinary pyridinolines, markers of bone turnover, whereas placebo and intranasal calcitonin did not. Alendronate was generally well tolerated and no serious adverse events were attributed to its use.(ABSTRACT TRUNCATED AT 250 WORDS)

Absorptiometry, Photon↗
PubMed1995

Clinical utility of a wheat-germ precipitation assay for determination of bone alkaline phosphatase concentrations in patients with different metabolic bone diseases.

Bone alkaline phosphatase was evaluated by wheat-germ lectin precipitation in several clinical conditions. The study included 33 premenopausal healthy women, 46 postmenopausal apparently healthy women, 19 growing children, 24 patients with Paget's disease, 31 patients with primary hyperparathyroidism and 66 patients with hepatobiliary diseases. In postmenopausal women the mean T score (i.e.: the number of SD below or above the mean for premenopausal women) was 2.6 +/- 1.3 (SD) for bone alkaline phosphatase and 1.61 +/- 1.21 for total alkaline phosphatase (p < 0.001). The T score for bone alkaline phosphatase provided a better discrimination from normals for both Paget's disease (22.1 +/- 27.8 versus 12.8 +/- 16 p < 0.001) and primary hyperparathyroidism (8.2 +/- 4.3 versus 4.6 +/- 3.7 p < 0.005 for bone alkaline phosphatase and total alkaline phosphatase respectively). After treatment with intravenous bisphosphonate the percent decrease of bone alkaline phosphatase was larger than that of total alkaline phosphatase both in patients with Paget's disease (-46% versus -72% p < 0.01) and in patients with primary hyperparathyroidism (-21% versus -47% p < 0.02) and an estimate of the precision (delta mean/SD of the delta mean) for bone alkaline phosphatase was 1.9-3.7 times higher than that of total alkaline phosphatase. In twelve osteoporotic patients treated for six months with oral alendronate the decrease in bone turnover was detected with significantly higher precision with bone alkaline phosphatase than with total alkaline phosphatase (p < 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1995

Bone mineral metabolism in girls with precocious puberty during gonadotrophin-releasing hormone agonist treatment.

Bone mineral metabolism and mineralization before and during treatment were studied in 10 girls aged 6.9-8.4 years affected by central precocious puberty and treated with gonadotrophin-releasing hormone agonist (GnRHa) leuprolide acetate depot, in order to understand better the consequences of oestrogen deficiency and the reduction of growth hormone (GH)-insulin-like growth factor I (IGF-I) axis activity. Before and after 12 months of therapy, the patients underwent a clonidine stimulation test and a 4-day calcitriol osteoblast stimulation test. On day 0, day 5 and at 3-month intervals thereafter, serum calcium, phosphate, alkaline phosphatase, IGF-I, IGF binding protein 3 (IGFBP-3), GH, GH binding protein and osteocalcin levels were measured; urinary calcium, phosphate and hydroxyproline levels were evaluated in fasting spot samples. Trabecular and cortical bone mass variations, measured by dual X-ray absorptiometry in the lumbar spine and by dual photon absorptiometry in the radius, respectively were evaluated before the start and after 12 months of therapy. During treatment, a decrease of serum oestradiol levels from pubertal to prepubertal levels was observed. The GH peak following clonidine diminished significantly after 1 year. Growth hormone binding protein showed a slight increase, and IGF-I and IGFBP-3 decreased, although not significantly. Osteocalcin levels decreased significantly after 9 and 12 months of treatment, but they did not change significantly after calcitriol load, either before or after GnRHa therapy. Urinary hydroxyproline decreased significantly after 12 months.(ABSTRACT TRUNCATED AT 250 WORDS)

Body Height↗
PubMed1995

[Rational bases for the treatment of osteoporosis].

Bone tissue undergoes a continuous process of remodelling through resorption of damaged tissue by osteoclasts and apposition of new bone by osteoblasts, at the level of basic multicellular units (BMUs). The number of BMUs ultimately defines bone turnover and it is by itself a source of scarcely mineralized bone. In young healthy individuals bone resorption and bone formation are strictly coupled at the level of the individual BMU and thus of the entire skeleton. Bone loss in the elderly is due to both excess resorption over formation and increased turnover. The inhibitors of bone resorption diminishes the number of BMUs and this invariably decreases the rate of bone loss. However their effect at individual BMU is uncertain. Estrogen replacement therapy lessens the rate of bone loss in postmenopausal women but it does not seem to correct the imbalance between resorption and formation. In several studies bisphosphonates have been shown to induce a continuous positive balance, and this might indicate that these compounds are able to correct the basic alteration of bone metabolism leading to age-related bone loss.

Bone Remodeling↗
PubMed1994

Long-term effects of a treatment course with oral alendronate of postmenopausal osteoporosis.

Several bisphosphonates are under investigation for the treatment and prevention of postmenopausal osteoporosis. Alendronate, one of these compounds, has been shown to inhibit bone turnover and induce substantial increases in bone mass, but little is known about the duration of its effects. This is considered important, keeping in mind the long half-life of bisphosphonate in bone. In this double-blind controlled study, two groups of 15 postmenopausal women with spinal bone mineral density (BMD) > 2 SD below adult mean peak without vertebral fractures were randomized to receive either alendronate, 20 mg/day, or placebo for 6 months. The treatment course with alendronate significantly suppressed all indices of bone turnover (hydroxyproline, collagen crosslinks, and alkaline phosphatase activity) within 3 months, and a further slight decrease was observed in the subsequent 3 months. After treatment withdrawal, all indices of bone turnover slowly increased, and they attained the pretreatment values within 6-9 months. Lumbar spine BMD rose by 3.7% (+/- 1.7 SD) after 6 months of alendronate therapy but did not change 6 and 12 months after treatment withdrawal (4.6 +/- 2.8 and 4.7 +/- 2.6% versus baseline, respectively). In control patients a slow decrease in lumbar spine BMD was observed, but this was significant only at month 18 of the study. Femoral BMD did not significantly change in the alendronate group, but it slowly decreased in the control group at all sites of evaluation. The fractional loss became statistically significant versus both baseline and the active group by the end of the study only at the level of the femoral neck.(ABSTRACT TRUNCATED AT 250 WORDS)

Absorptiometry, Photon↗
PubMed1994

Optimizing peak bone mass: what are the therapeutic possibilities?

Bone mass in the elderly depends on the rate of involutional bone loss and on the peak bone mass, i.e. the bone mass present around the third decade of life. Factors relating to the attainment of peak bone mass include congenital factors, diet, hormones, physical activity, life-style factors, drugs and diseases. A therapeutic intervention aimed at increasing peak bone mass is conceivable only by controlling factors such as estrogen status, dietary calcium intake and physical activity. Calcium intake appears to be relevant up to the so-called threshold intake (1000 mg/day), but higher allowances do not seem to offer additive advantages. Exercise affects only the regions of the skeleton under mechanical stress. Estrogen administration is realistic only in conditions characterized by severe hypoestrogenism.

Bone Density↗
PubMed1994

Bone loss in the elderly.

A large number of cross-sectional studies suggest that rates of bone loss decrease in the elderly, particularly at the spine and radius. For this reason it has been argued that bone mass measurements are unhelpful in assessing fracture risk in the elderly and that drugs affecting bone metabolism are less likely to be of benefit in reducing this risk. This paper reviews the assumptions on which these conclusions are based and argues that in many instances they are flawed. Indeed, studies examining rates of bone loss in the elderly either directly or by biochemical indices of bone turnover suggest that bone loss continues throughout life and may even accelerate after the age of 70 years. This conclusion supports the view that identification of patients at risk and subsequent treatment is of value in all age groups.

Absorptiometry, Photon↗
PubMed1994

Duration of the effects of intravenous alendronate in postmenopausal women and in patients with primary hyperparathyroidism and Paget's disease of bone.

The effect of a single intravenous (i.v.) infusion of 5 mg alendronate was studied in ten patients with Paget's disease, six patients with primary hyperparathyroidism and ten osteopenic postmenopausal women. Urinary hydroxyproline excretion significantly decreased within few days in all patients (from 113 +/- 67.9 to 58 +/- 35 mmol/mol Cr in Paget's disease, from 21.8 +/- 9 to 12.9 +/- 6 mmol/mol Cr in hyperparathyroidism, from 18.7 +/- 9.5 to 8.5 +/- 4.3 mmol/mol Cr in postmenopausal women). In the patients with Paget's disease urinary hydroxyproline remained suppressed over the 6 months of follow-up, whereas it rose toward pretreatment values within 4 and 6 weeks in the patients with primary hyperparathyroidism and in postmenopausal osteopenic women, respectively. Plasma alkaline phosphatase significantly fell only after 4-6 weeks in patients with primary hyperparathyroidism and in Pagetic patients. In the latter group alkaline phosphatase continued to decline thereafter and a plateau became apparent after 2 months. In postmenopausal women the serum alkaline phosphatase remained unchanged. Thus, the same dose of alendronate induces comparable fractional decreases of bone resorption in the three groups of patients, but the effect is persistent only in Paget's disease. This is consistent with the hypothesis that alendronate inhibits osteoclastic activity only at the level of the existing resorption sites. In osteoporotic and primary hyperparathyroid patients, as soon as the treatment is withdrawn, the appearance of new sites of resorption is not inhibited and bone turnover is resumed to pre-treatment values.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1993

Treatment of postmenopausal osteoporosis with continuous daily oral alendronate in comparison with either placebo or intranasal salmon calcitonin.

Alendronate sodium (ALN) is a potent amino bisphosphonate which specifically inhibits osteoclastic bone resorption and has been found to reverse bone loss in several animal models. To determine if daily oral ALN treatment could prevent or reverse bone loss in osteoporotic postmenopausal women, and to compare ALN to intranasal salmon calcitonin (CT), a 2-year, double-masked, randomized, placebo-controlled study was initiated at 9 clinical centers in Italy. Two hundred and eighty six postmenopausal women (age 48-76) with spinal bone mineral density (BMD) > or = 2 SD below adult mean peak, with or without vertebral crush fractures, were randomized to one of four treatment arms: ALN 10 mg daily, ALN 20 mg daily or matching placebo (these groups all double-masked), or CT 100 IU daily (open label) for 2 years. All patients received supplemental calcium (as carbonate) 500 mg daily. Bone mass was measured by dual-energy X-ray absorptiometry of the PA lumbar spine (LS) and proximal femur (femoral neck and trochanter) at 6-month intervals. Subject safety was measured through sequential clinical and laboratory evaluation. A planned 1-year interim analysis of this ongoing study was performed centrally in a manner that maintains the double-mask for all subjects receiving oral study drug. Relative to PBO, ALN at either 10 mg or 20 mg daily increased LS BMD by 4.7% and 6.1%, respectively; each increased femoral neck BMD by 3.1% and increased trochanter BMD by 3.3% and 3.8% respectively. In contrast, CT failed to significantly increase BMD of either the spine, femoral neck or trochanter, either relative to baseline or to PBO.(ABSTRACT TRUNCATED AT 250 WORDS)

Administration, Intranasal↗
PubMed1993

Long-term effects of transdermal and oral estrogens on serum lipids and lipoproteins in postmenopausal women.

The transdermal and oral administration of estrogens for one year were compared with respect to the effects on lipid metabolism. Eighty-one postmenopausal women (1.5-3 years after menopause) were randomly divided into three groups. The first two groups received sequential estrogen treatment with either transdermal estradiol (Estraderm TTS, Ciba Geigy; 50 micrograms/day; 24 women) or 0.625 mg/day conjugated estrogens (Premarin, Wyeth; 20 subjects), respectively. In both groups medroxyprogesterone (10 mg/day per os) was added for 12 days of each cycle. Thirty-five subjects served as control group without therapy. No significant changes in the lipid profile was observed in control subjects after 1 year of follow-up. Serum triglycerides decreased significantly (-10.9 +/- 26% S.D.; P < 0.05) in transdermal treated women, whereas it slightly rose in oral estrogen group. Comparable significant decreases in total and low density lipoprotein (LDL) cholesterol (mean range -6.5/-18.0%) were observed in women on estrogen replacement therapy. High density lipoprotein (HDL) cholesterol significantly diminished in transdermal estradiol group, but it rose slightly in the oral estrogen group. Thus the fraction of HDL cholesterol over LDL cholesterol did not change in the transdermal group whereas it significantly rose in subjects treated with oral estrogens. It remains to be established to what extent these differences on lipid metabolism are relevant for the prevention of cardiovascular diseases.

Administration, Cutaneous↗
PubMed1993

Effects of 1,25-dihydroxyvitamin D3 and growth hormone therapy on serum osteocalcin levels in children with growth hormone deficiency.

In order to investigate the influence on bone metabolism of growth hormone (GH), we evaluated the response to an acute load of 1,25(OH)2D3 (Rocaltrol) (1.5 micrograms/day for 4 days) in 16 growth hormone-deficient prepubertal children (11 boys and 5 girls, aged from 6.2 to 9.6 years) both before and after 1 month of human GH (hGH) therapy (0.1 IU/kg/day, 6 times per week). Before and after the 1,25(OH)2D3 load, serum IGF-I, osteocalcin, Ca, P, alkaline phosphatase (ALP) and urinary excretion of Ca and P were measured. The serum levels of osteocalcin rose significantly after the first 1,25(OH)2D3 load, without an increase in IGF-I values and with a slight non-significant increase in serum Ca and P. Almost superimposable increases of osteocalcin, Ca and P were observed after 1 month of hGH therapy, with a significant increase of IGF-I, but they did not rise further after the second 1,25(OH)2D3 load. On the basis of our results, 1,25(OH)2D3 seems to have a stimulatory action on osteoblastic activity even in the absence of normal levels of GH. However, there is no apparent additional stimulatory activity after administration of hGH. Osteocalcin level behaviour during our study might suggest that GH and 1,25(OH)2D3 have a common and easily saturable stimulatory pathway on osteoblastic function.

Alkaline Phosphatase↗
PubMed1993

Influence of aging and menopause in determining vertebral and distal forearm bone loss in adult healthy women.

In order to assess the relative influence of aging and menopause in determining the decrease of bone mass in adult women, two groups of normal subjects were examined in this retrospective, cross-sectional study. In group A, bone mineral density (BMD) was evaluated at spine (L2-L4) by dual X-ray absorptiometry (DXA) (Hologic QDR-1000); in group B, BMD was measured at the distal forearm by single photon absorptiometry (SPA) (Osteometer DT 100). Both groups were further divided into two subgroups: A1 and B1 included women with the same postmenopausal, but different chronological age; A2 and B2 included women with the same chronological, but different postmenopausal age. BMD and BMI-corrected BMD (cBMD) were plotted versus age and years since menopause, respectively. Mathematical analysis of the correlation curves between BMD and chronological age showed that the decrease of BMD is very similar at spine and forearm, and is better fitted by a quadratic function. Age-related fractional bone diminution shows a progressive increase with aging (at spine: -0.38%/year at 45 years, -0.81%/year at 50, -1.3%/year at 55 and -1.9%/year at 60. At forearm: -0.5%/year at 50 years, -1.1%/year at 55 and -1.68%/year at 60). On the other hand, menopause-related BMD decrement is very evident during the first year since menopause (at spine: -8.1%/year; at forearm: -3.4%/year), and progressively decreases, according to a logarithmic function. Ten years later, yearly diminution of BMD is below 1%/year and 0.4%/year at spine and forearm, respectively. At this time, age contributes to determine bone loss for 2/3 and menopause for 1/3.

Absorptiometry, Photon↗
PubMed1993

Bone mineral density in children and adolescent females treated with high doses of L-thyroxine.

Single-photon absorptiometry was used to assess forearm bone mineral content (BMC) at a proximal site (PBMC) and at a more distal site (DBMC) of the non-dominant distal forearm in 20 children and adolescent females taking high doses of L-thyroxine (120 micrograms/m2/day) for a period of 6-96 months for endemic goiter, Hashimoto's thyroiditis or thyroid cancer. PBMC was significantly reduced compared to controls (p < 0.002). No correlation was found between PBMC, the values of circulating thyroid hormones and the indices of tissue hyperthyroidism such as TSH and systolic time intervals (STI), suggesting that bone is a very sensitive target for thyroid hormones. Further studies are necessary to confirm our findings and to verify their clinical significance. At present, we believe that suppressive doses of L-thyroxine should be reserved for cancer patients only.

Adolescent↗
PubMed1993

Effects of therapeutic doses of salbutamol alone and combined with beclomethasone dipropionate on airway responsiveness and cyclic AMP plasma levels in asthmatic patients.

Twelve asthmatic patients received by inhalation for 2 weeks, in a double-blind, cross-over design, beclomethasone dipropionate (BDP; 600 micrograms/day) plus salbutamol (S; 900 micrograms/day), or S (900 micrograms/day) alone. Before and after each treatment course the subjects received intravenous cumulative doses of S up to 200 micrograms. In basal conditions and immediately before the next dose forced expiratory volume in 1 s (FEV1) and plasma cyclic AMP (cAMP) were measured. BDP+S treatment increased FEV1 basal values (p < 0.05) whereas inhaled S resulted in unsignificant improvement of ventilatory parameters. The slopes of the dose-response curves of FEV1 and plasma cAMP to intravenous S were unaffected by the two treatment courses. Our results suggest that DBP+S, differently from S alone, improves ventilatory function in asthmatic patients and that neither S nor S+BDP seem to affect adrenergic function.

Administration, Inhalation↗
PubMed1993

Anabolic steroids in corticosteroid-induced osteoporosis.

Severe osteoporosis represents a major complication of corticosteroid (CST) excess. Steroid-induced osteoporosis is characterized by both increased bone resorption and inhibition of bone formation. Excessive bone resorption is attributed to hyperparathyroidism which is secondary to calcium malabsorption. Calcium and vitamin D supplementation or treatment with inhibitors of bone resorption are of benefit but they usually lead to further inhibition of bone formation. The inhibition of bone formation in CST treated patients is due in part to suppression of adrenal androgen secretion. Thus the suppressed circulating levels of osteocalcin, a biochemical marker of osteoblast activity, in patients on CST can be reverted to normal by administration of anabolic steroids. In a prospective controlled trial in patients on long-term CST therapy we have observed that nandrolone decanoate therapy, 50 mg intramuscularly every 3 weeks for 18 months, induces a transient increase in bone mass within the first 6 months of treatment and prevent further losses thereafter. The sequential biochemical changes indicate that nandrolone decanoate in patients on CST inhibits bone resorption without affecting or even increasing bone formation. Furthermore in patients on CST treatment the virilizing activity of nandrolone decanoate was virtually negligible at least within the 18 months of treatment. These results indicate that anabolic steroid administration may represent a rational and convenient strategy for preventing and treating CST-induced osteoporosis.

Adrenal Cortex Hormones↗