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Biomedical subjects

A Peretz

Publications and source records attributed to A Peretz.

At least 73 records · Page 4Linked to original sources
PubMed1991

Choice of parameter for expressing bone mineralization.

In this cross-sectional study, the relative importance of anthropometric factors and that of biological parameters on bone mineralization were evaluated and their practical implications inferred on the choice of the parameter to be used for the estimation of bone mineralization. A close relationship between anthropometric factors and bone mineral content (BMC) was observed and this relationship was shown to be independent of age. Furthermore, by regression analyses, anthropometric parameters appeared to explain a large part of the variance in BMC and preceded the hormonal parameters in the stepwise analysis of this model. Using bone mineral density (BMD) data, however, we observed a weaker relationship between anthropometric factors and bone mineralization and a relatively stronger relationship between steroid hormones and bone mineralization than those observed using the BMC data. Furthermore, by multiple regression analysis the hormonal factors preceded the anthropometric parameters in the stepwise analysis of the model. As strong epidemiological and clinical evidence exists on the relationship between steroid hormones and bone loss, these results constitute a supplementary argument for the use of BMD for the estimation of bone mineralization.

Adult↗
PubMed1991

Oesophageal involvement in rheumatoid arthritis patients: a study with oesophageal radionuclide transit using 81Krm.

Rheumatoid arthritis (RA) is an inflammatory disease affecting mainly the joints. In addition, signs of systemic disease are likely to be present although they are not always clinically evident. Oesophageal motility dysfunction, present in 75% of progressive systemic sclerosis patients, was also reported in various other connective tissue diseases. The present study involved 32 rheumatic patients devoid of any gastrointestinal complaints or diseases: 16 RA, nine Raynaud's syndrome and seven mild osteoarthritis as controls. Oesophageal transit was assessed by using 81Krm radionuclide scan, a sensitive and non-invasive technique. Diffusing lung capacity for carbon monoxide (DLCO) was performed as evidence of subclinical systemic involvement. Abnormal oesophageal transit was observed in 5/16 RA (31%). Two of them were subsequently discarded due to the presence of asymptomatic goiter and asymptomatic gastrointestinal reflux leaving 3/14 RA for analysis. They all had extra-articular features (EAF) (pericarditis, nodules) and two of them had diminished DLCO. Two with Raynaud's syndrome had abnormal oesophageal transit but none of the controls had abnormal oesophageal transit. Upper gastrointestinal dysfunction after exclusion of symptomatic patients appears thus to be not very frequent in RA, even when a sensitive technique is used. Radionuclide transit scanning of the oesophagus is not a more useful method than others in detecting early EAF in RA.

Adult↗
PubMed1991

Effects of chronic prednisolone administration on plasma copper in rats with adjuvant arthritis.

Copper metabolism is known to be significantly affected by inflammation or by glucocorticoid administration. We have previously demonstrated that acute prednisolone administration induces a moderate but sustained increase in plasma copper in healthy rats while it induces a more pronounced but shorter increase in rats with adjuvant arthritis. In the present study we have investigated the effects of chronic prednisolone administration (around 0.65 mg/kg daily in food) in both healthy rats and rats with adjuvant arthritis at various stages of the disease. In healthy rats, a slight but significant increase of 11% was observed in plasma copper after 3 weeks of treatment. This modification was no longer apparent after 5 weeks of treatment. In arthritic rats, plasma copper was, as expected, higher than in healthy rats and reached a maximum 3 weeks after adjuvant injection. In prednisolone-treated arthritic rats, there was a sustained decrease in plasma copper starting after 2 weeks of treatment which could be correlated with an improvement of the clinical and biochemical signs of inflammation. In conclusion, chronic prednisolone treatment only slightly increases plasma copper in healthy rats while in arthritic rats plasma copper is dependent on the severity of the disease which is improved by the treatment.

Administration, Oral↗
PubMed1991

[Cortisone-induced osteoporosis: from physiopathogenesis to treatment].

Glucocorticoids are useful as therapeutic agents in a wide variety of clinical disorders for their antiinflammatory, immunosuppressive and cytolytic properties. When administered in supraphysiological doses they cause an array of undesired side-effects that greatly limit their clinical utility. Among them, the development of osteoporosis is critical. It is a multifactorial process with important actions occurring in bone and other sites. As a consequence, an uncoupling of bone turnover is observed with a decrease in bone formation and an increase in bone resorption. The efficacy of preventive and therapeutic interventions are limited but an area of new perspectives are currently under investigation.

Bone Resorption↗
PubMed1990

Age, steroids and bone mineral content.

The possible existence of correlations between bone mineral content (BMC), age and serum levels of steroid hormones was investigated. It was found that dehydroepiandrosterone sulphate (DHEA-S), oestradiol (E2) and delta-4-androstenedione (A) were correlated with BMC, whereas oestrone (E1) and testosterone (T) were not. Partial correlations after adjustment for age were significant (P less than 0.05) only between E2 and DHEA-S and BMC at the L2-L4 lumbar site (BMC-1) and between DHEA-S (P less than 0.01) and BMC at the midradius site (BMC-r). Stepwise multiple regression analysis showed that, apart from age, E2 was the only factor to fit (P less than 0.05) into the mathematical model with BMC-1 as the dependent variable, while DHEA-S was the only factor to fit (P less than 0.01) with BMC-r as the dependent variable. These data suggest that different hormonal influences are related to BMC at different sites, namely E2 to lumbar trabecular bone (L2-L4) and DHEA-S to cortical bone (midradius).

Adult↗
PubMed1989

Osteocalcin and bone mineral content in rheumatoid arthritis.

Abnormal bone metabolism was reported in rheumatoid arthritis (RA). In order to evaluate the interest of serum osteocalcin, also called bone GLA-protein (BGP), to assess bone metabolism in RA, we studied 20 postmenopausal RA out-patients and 20 matched controls. Nine patients were treated with low-dose corticosteroids (C+) for at least one year (less than 10 mg/day, prednisolone equivalent), the remaining 11 (C-) received non-steroidal anti-inflammatory drugs (NSAID). The distal and proximal forearm bone mineral content (BMC) was measured by single photon absorptiometry, the vertebral BMC was measured by dual photon absorptiometry. A trend to low BGP was observed in the C+ group. The lowest values were observed in patients with vertebral fractures. Compared with controls, both RA groups had similar low significant BMC at the forearm sites. At the vertebral sites, the bone mineral content decrease observed in the two groups, was more marked in the C+ group. From our results, BGP did not appear as a useful index of osteoporosis in RA, except in some patients with vertebral fractures, treated with low-dose corticosteroids.

Aged↗
PubMed1989

Effects of chronic and acute corticosteroid therapy on zinc and copper status in rheumatoid arthritis patients.

The modifications in plasma, erythrocyte and urine zinc and copper concentrations induced by chronic or acute corticotherapy were studied in patients suffering from rheumatoid arthritis and the results compared with those from controls. Patients not treated with corticosteroids had low plasma zinc and high plasma copper, which significantly correlated with inflammatory parameters (erythrocyte sedimentation rate and C-reactive protein); no change was observed in erythrocyte and urine zinc and copper. Oral long-term treatment with corticosteroids (less than 10 mg prednisolone/day) was associated with a further decrease in plasma zinc only in patients with moderate inflammation. Changes induced by such a treatment were less intense than those due to severe inflammation. The administration of intravenous high doses (1 g methylprednisolone/day) resulted in a rapid decrease in plasma zinc with a return to baseline levels two days after withdrawal. The modification was associated with a sustained increase in urine zinc and copper without changes in diuresis.

Administration, Oral↗
PubMed1989

[Anthropometric factors in the prevention of osteoporosis].

Osteoporosis, an important health problem, essentially concerns postmenopausal women since women have a lower peak bone mass than men when they reach adulthood and since the menopause is associated with an accelerated bone loss. We retrospectively analysed the bone measurements of 318 women, age less than 50. The bone mineral contents and densities of the mid- and distal radius (BMC m-rad, BMD m-rad, BMC d-rad, BMD d-rad) and of the lumbar L2-L4 vertebra (BMC L2-L4, BMD L2-L4) were measured using single and dual photon absorptiometer, respectively. The relations between age, height, weight, body mass index and the bone measurements were studied using multiple regression analyses. The anthropometric factors were accepted as first factors in the equations. R2 were respectively 17%, 17%, 28% for BMC m-rad, BMC d-rad, BMC L2-L4 and 7%, 5%, 8% for BMD m-rad, BMD d-rad, BMD L2-L4. These data suggest that anthropometric factors have an important influence on the different bone measurements. They also draw attention on the importance of preventive measures to achieve and to maintain an optimal bone reserve in premenopausal women.

Adult↗
PubMed1989

Comparison of effects of chronic inflammation and long-term prednisolone administration on zinc metabolism in rats.

It is well known that plasma zinc is depressed in animals following administration of endotoxin, endogenous pyrogen, interleukin-1, and glucocorticoids. The modification is related to an induction of liver metallothionein causing an accumulation of the element in this organ. The changes in zinc metabolism induced by adjuvant arthritis in rats evidenced a redistribution of body zinc with a rapid and sustained decrease in plasma zinc that occurred simultaneously with an increase in liver zinc levels, and slower modification in erythrocyte and femur zinc concentrations. These effects were compared to those induced by a long-term corticosteroid administration in healthy rats. Male Wistar rats received either a commercially available complete maintenance diet or the same diet enriched with prednisolone at a level providing 1 mg prednisolone/kg body weight. Groups of animals were sacrificed after 3 or 5 weeks' treatment. Ingested food quantity, total body weight, total serum proteins and serum albumin were similar in treated and control rats. No significant modifications in parameters of zinc status could be observed after 3 weeks of treatment. However after 5 weeks, plasma zinc was significantly lower in treated rats as compared to controls, but modifications in liver, erythrocyte and femur zinc did not reach statistical significance. Changes induced by long-term corticosteroid administration are therefore less intense than those due to the inflammatory process of adjuvant arthritis.

Adrenal Cortex Hormones↗
PubMed1989

[Usual values of selenium and glutathione peroxidase in a Belgian population].

Several biological parameters for assessing selenium status have been determined in years 1985-1986 in a large Belgian population group, males and females 0 to 92 years old, representative from Brussels and surroundings. In 145 people, 20 to 79 years old, mean concentrations were: 1.06 +/- 0.15 mumol Se/l plasma, 5.0 +/- 1.1 nmol Se/g Hb in erythrocytes and 7.4 +/- 2.0 mu/g Hb for the selenodependent glutathione peroxidase activity measured in erythrocytes (mean +/- standard deviation). Values for urine selenium have a disymmetric distribution and range from 0.05 to 0.65 mumol Se/g creatinine. No difference was evidenced in this group according to sex and age. Children below 20 years and elderly above 80 years have decreased plasma and erythrocyte selenium concentrations but glutathione peroxidase is not modified. These blood selenium concentrations are lower than those determined in a similar population group in years 1980-1981, suggesting a progressive decrease in selenium intake. The concentrations of the biological parameters are not correlated together except in selenium deficient patients having plasma selenium less than 0.75 mumol/l: a significant correlation is observed between plasma selenium and erythrocyte glutathione peroxidase activity, that becomes more intense with decreasing plasma selenium. Finally, two recent investigations are described where a significant response in platelet glutathione peroxidase was obtained during a 60 days selenium supplementation with 100 to 200 micrograms selenium per day, suggesting that usual selenium intake in Belgium (50 micrograms per day) is marginally deficient.

Adolescent↗
PubMed1989

Concomitant osteitis fibrosa cystica and ameloblastoma of the mandible.

A patient with a multiloculated cystic lesion of the mandible, and clinical as well as biological features of hyperparathyroidism is presented. This association suggesting the diagnosis of brown tumor was actually due to an ameloblastoma of the mandible. Such a concomitant association of an ameloblastoma with symptomatic hyperparathyroidism has never been reported to our knowledge.

Adenoma↗
PubMed1989

Serum osteocalcin in the assessment of corticosteroid induced osteoporosis. Effect of long and short term corticosteroid treatment.

Serum osteocalcin was measured in patients receiving corticosteroid for long and short term at different doses. Low osteocalcin levels were observed in treated patients compared to age and sex matched controls (p less than 0.001). The effect was dose dependent and paralleled the adrenal inhibition assessed by morning cortisol. Short term administration resulted in a rapid decline of baseline osteocalcin which was maintained during the treatment period and was reversible after withdrawal. Osteocalcin appeared as a sensitive index of the inhibitory effect of corticosteroid on osteoblasts.

Adolescent↗
PubMed1988

Changes in zinc, copper and selenium status during adjuvant-induced arthritis in rats.

Trace elements such as zinc, copper and selenium are involved in the pathogenesis of inflammatory diseases. In order to obtain more information about the overall movements of these minerals during the evolution of an experimental chronic inflammatory process, trace element levels were determined in five body compartments of the rat at several time intervals after induction of adjuvant arthritis. Rapid and significant changes in plasma zinc and copper levels and in liver zinc levels were observed. These modifications occurred as early as those in biochemical parameters of inflammation such as serum fibrinogen and ceruloplasmin, and preceded the appearance of any clinical symptom of the disease. Inverse correlations were found between plasma zinc levels and these two biochemical indices. Other modifications in trace element levels were observed two weeks after disease induction, the most important being a considerable increase in liver copper levels. Although food intake of affected animals decreased with the progression of the disease, there was no evidence of depletion in zinc and copper levels over the study period. A redistribution of body zinc between different biological compartments (mainly plasma and liver) occurred simultaneously with an accumulation of copper in several organs. The decreasing selenium status of animals was not clearly related to the inflammatory process.

Animals↗
PubMed1988

Serum levels of gonadotrophins and steroid hormones in the post-menopause and later life.

Changes in the serum levels of gonadotrophins and steroid hormones with increasing age were studied in 449 women aged 40 and over to investigate the relationships between these hormones even very late in life. The levels of oestradiol (E2) and dehydroepiandrosterone sulphate (DHEA-S) fell after age 50 and remained low thereafter. However, while serum oestrone (E1), testosterone (T), delta-4-androstenedione (A) and prolactin (PRL) concentrations also decreased initially after age 50 they subsequently rose again progressively and this increase was in fact significant in the case of E1. Luteinizing hormone (LH) and follicle-stimulating hormone (FSH) rose after age 50, but whereas FSH remained elevated, LH decreased late in life. Cortisol (F) increased significantly after age 70. There was a significant correlation between androgens and E1 as well as between E2 and LH, even after age 60. Owing to the great heterogeneity of the population studied, it is not yet possible to speculate as to the physiopathological significance of these observations. It would seem, however, that the negative feedback effect of oestrogens on LH secretion remains operational very late in life.

Aged↗