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Biomedical subjects

R Foti

Publications and source records attributed to R Foti.

At least 37 records · Page 2Linked to original sources

[Modification of cortical and trabecular mineral density of the femur, induced by ipriflavone therapy, Clinical results after 12 months].

In order to evaluate the effects of ipriflavone therapy, a clinical and metabolic study was carried out in a group of female patients with low bone mass. In particular, mineral density of the proximal femur was measured, this being a fundamental factor for the resistance of this district. At the end of the 12-months treatment cycle, reduced plasma concentration of Bone Gla Protein and urinary hydroxyproline/creatinine ratio (indicating reduced bone resorption), and a significant increase of bone density of the femoral neck and of the trabecular substructure of Ward's triangle were found. On the whole, treatment was well tolerated.

Adult↗

Differences in the time course of the effects of oophorectomy in women on parameters of bone metabolism and interleukin-1 levels in the circulation.

Interleukin-1 is a cytokine with bone-resorbing activity which is claimed to play a role in the pathogenesis of osteoporosis and of post-oophorectomy bone loss. We measured plasma levels of interleukin-1 (IL-1) in 16 women who underwent hysterectomy and bilateral oophorectomy and in 12 women with hysterectomy alone before surgery and 7, 15, 30, 45 and 60 days after surgery. Only oophorectomized patients showed a significant increase of circulating interleukin-1 levels. This increase was significant only 30 days after surgery, whereas a rise at 7 days (P < 0.001) was observed for serum calcium and hydroxyproline/creatinine and calcium/creatinine ratios. These data do not indicate a definite role of IL-1 in promoting bone resorption in estrogen-deficient women in vivo.

Adult↗

Evaluation of the biological activity of unmodified synthetic eel calcitonin rectal capsules. Comparison with intramuscular administration and placebo.

Biological activity of eel calcitonin 100 IU administered by the rectal route was evaluated in healthy volunteers by measuring plasmatic variations of cyclic adenosine monophosphate (cAMP) after a single dose and during a 21-day treatment. This formulation appears to allow a bioavailability of the drug which is half of the same dose administered intramuscularly, and to cause a prompt and significant increase of plasma cAMP, with minimal variations of calcaemia. Repeated administration shows the persistence in time of this effect. The overall conclusion is that the amount of calcitonin absorbed through the rectal mucosa seems sufficient to induce a typical biological response related to the interaction of the hormone with its specific receptors in bone.

Administration, Rectal↗

The effects of muscle-building exercise on forearm bone mineral content and osteoblast activity in drug-free and anabolic steroids self-administering young men.

We measured bone mineral content (BMC) and bone density (BD) at appendicular sites by single photon absorptiometry in 18 men engaged in body-building exercises for at least 2 years, and in 14 age- and weight-matched controls. Eight exercises were using anabolic steroids by self-administration. Serum levels of bone Gla-protein (BGP), a reliable index of bone formation were also measured in all subjects. It was observed that muscle-building exercise was associated with increased BMC and BD at the distal radius, which contains both cortical and trabecular (more than 50%) bone. Previous authors have failed to detect any increase in BMC at mid radius, a site consisting almost entirely of cortical bone. Serum BGP levels were significantly higher in exercisers than in controls. If compared to drug-free exercisers, subjects taking steroids showed no significant increase of BMC, BD and serum levels of BGP. This study shows that muscle-building exercise is associated with increase in BMC and BD also at non-weight bearing sites, and that anabolic steroids did not provide, at the time of the observation, any further stimulus for osteoblast activity and bone formation.

Absorptiometry, Photon↗

Assessment of the biological activity of synthetic salmon calcitonin by intranasal administration in healthy volunteers.

The authors conducted an open crossover trial of the biological activity of single-dose salmon calcitonin (sCT) 100 I.U. by nasal spray versus single-dose sCT 50 I.U. by intramuscular route in six healthy volunteers. The biological activity of the hormone was assessed on the changes in the blood levels of calcium, cAMP and osteocalcin recorded in the 4 h following administration. The increase in plasma cAMP shows that the hormone acts effectively by the nasal route. Further, the lack of statistically significant differences between the two modes of administration in any of the parameters considered demonstrates the bioequivalence of 50 I.U. of sCT i.m. and 100 I.U. of sCT intranasally.

Administration, Intranasal↗

[Early myocardial involvement in collagen diseases. An endomyocardial biopsy study].

Endomyocardial biopsy was performed in three patients affected by systemic connectivitis (one case of systemic lupus erythematosus--SLE--, one of scleroderma and one of dermatomyositis). The analysis of the specimens revealed the presence of fibrosis and microvascular lesions (these latter only in SLE). Immunofluorescence showed in SLE and scleroderma perivascular IgG or perisarcolemmal IgM deposits respectively. Despite the scarcity of cardiac signs and symptoms, cardiac involvement can be early and frequent in connectivitis. The immune pathogenesis of the cardiac lesions seems to be possible because of the presence of immunocomplexes in the myocardium.

Adolescent↗

Reduced axial bone mineral content in patients taking an oral anticoagulant.

Recent literature indicates that the vitamin K cycle plays a role in the calcification process, presumably via its intervention on gamma-carboxylation of the noncollagenous proteins of bone osteocalcin and matrix gamma-carboxyglutamic acid protein. The major clinical evidence of this interference is fetal bone defect caused by oral anticoagulants given to the mother during the first trimester of pregnancy. No bone abnormalities have been reported so far in adults receiving oral anticoagulants. We studied 56 women who had had cardiac valve replacement and who were given acenocoumarol as anticoagulant, and 61 age-matched women who were in the same New York Heart Association functional class but who were not taking anticoagulants. Osteocalcin serum levels were comparable between the two groups; bone density values measured at appendicular bone were significantly lower in patients taking acenocoumarol. No significant correlation was found between duration of treatment and bone density. Significant osteopenia was present in the women being treated with oral anticoagulants.

1-Carboxyglutamic Acid↗

Serum antibodies to human enteric coronavirus-like particles in Australia, South Africa, Indonesia, Niue, and Papua New Guinea.

Relatively high levels of antibody to human enteric coronavirus-like particles were detected in the sera from rural Aborigines in Australia. Levels were generally much lower in the sera from urban Aborigines, and extremely low to not detectable in the sera from Europeans. Antibody to coronavirus-like particles was also detected in the sera from rural blacks from South Africa, in the sera from Indonesia and Niue, and also possibly in the sera from rural villagers from Papua New Guinea, but in the latter case at only very low level.

Adolescent↗

Endomyocardial biopsy in diagnosis and management of cardiovascular manifestations of systemic lupus erythematosus (SLE).

In recent years, the cardiovascular manifestations of systemic lupus erythematosus have became more apparent as a consequence of both prolonged survival and improvement in diagnostic modalities. We report the case of a 16-year old woman with systemic lupus erythematosus in whom the presence of cardiomyopathy was characterized by endomyocardial biopsy. This diagnostic technique also showed that the histologic hallmark of lupus myocardiopathy persisted despite corticosteroid and plasmapheresis, suggesting the need of a careful cardiac follow-up in these patients.

Adolescent↗

Effects of ovariectomy and 17 beta-estradiol on bone GLA protein in growing rats: an indirect evidence for estrogen receptors in bone cells.

Estrogen deficiency after ovariectomy in the rat is followed by an increase of bone turnover and bone loss. Estrogens are thought to modulate the sensitivity of skeleton to Parathyroid Hormone; according to the recently reported evidence of estrogen receptors on osteoblasts, however, a direct effect on bone cells should not be ruled out. We studied the behaviour of Bone Gla Protein (Osteocalcin), a reliable marker of osteoblast function, in growing rats after ovariectomy and treatment with 17 beta-estradiol. Results indicate that ovariectomy stimulates, as expected, bone turnover, and that estrogen induces a further increase of osteoblast activity revealed by the rise of Bone Gla Protein plasma levels. This data may have clinical implications in humans, where estrogens are currently suggested for prevention and therapy of post menopausal osteoporosis.

Animals↗

Bone mineral content of the hyperprolactinemic rat femur by single photon absorptiometry.

Chronic hyperprolactinemia was obtained in the rat by an implantation of two adenohypophyses under the kidney capsule. This experimental model was set to evaluate the influence that high prolactin levels may have on bone mineralization when an intervention of estrogens can reasonably be excluded. Bone density was measured by single photon absorptiometry at the femur level. Our results indicate that the increase in PRL throughout the period of observation was associated with a significant decrease in bone mineral content, while calcium and parathyroid hormone serum levels remained unchanged. This would suggest that PRL plays a role in bone calcium metabolism, that might be included among the effects of this hormone.

Animals↗

Postoophorectomy bone loss is associated with reduced bone Gla protein serum levels: a possible effect of osteoblastic insufficiency.

To further investigate the relationship between oophorectomy (OF) and mineral bone loss, 15 women who underwent total hysterectomy and bilateral oophorectomy were studied for 12 months after surgery. Mineralometric and metabolic data were obtained before and after 3, 6, and 12 months. The women lost bone mineral content (measured by single photon absorptiometry) at the same rate they lost cortical and trabecular bone, suggesting that bone loss after OF is a generalized phenomenon. Our data also show that an increase in bone resorption takes place only in the first period after OF; the persistency of a negative bone balance up to 12 months, accompanied by a reduction of osteocalcin serum levels, may be dependent on a reduced bone formation, probably due to osteoblastic insufficiency.

1-Carboxyglutamic Acid↗

Calcium-induced serum bone Gla protein variations in preterm newborns.

The effect of calcium infusion on osteocalcin(Bone Gla Protein, BGP) serum levels were studied in a group of preterm newborns with bw appropriate for gestational age. Results showed that basal BGP serum levels in preterm newborns are higher than those reported at birth in normal infants. Moreover, calcium infusion induced a significant decrease in BGP values, inversely correlated with serum calcium. Since calcium loading increases both Ca availability for bone formation and BGP affinity for mineral surfaces, reduction of osteocalcin serum levels might reflect a shift of the protein from bloodstream to bone, suggesting an intervention in regulating an effective calcium uptake.

Calcium↗

Acute effects of salmon calcitonin in man include stimulation of the renin-angiotensin-aldosterone system.

The present double-blind placebo-controlled cross-over study was designed to evaluate the renin-angiotensin-aldosterone system behavior after a short-term infusion of a pharmacological dose (100 MRC U) of salmon calcitonin. Overall, a significant increase in plasma renin activity, aldosterone and serum angiotensin-converting enzyme was seen throughout. This effect may be, at least in part, due to the renal loss in sodium and calcium ions, while the increased kaliuresis could be interpreted as a consequence of the stimulation of aldosterone release.

Adult↗