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M J Cals

Publications and source records attributed to M J Cals.

At least 19 recordsLinked to original sources

Reactive oxygen species induce apoptosis of synoviocytes in vitro. Alpha-tocopherol provides no protection.

Reactive oxygen species (ROS) are released during the inflammation of the synovial membrane associated with cartilage degradation in osteoarthritis. In this work, we exposed synoviocytes to superoxide anions at concentrations that may cause either apoptosis or necrosis. We studied membrane organization, dehydrogenase mitochondrial activity and nuclear morphology and integrity, to determine the nature of the death process initiated by superoxide anions and tried to counteract ROS effects with alpha-tocopherol. We found that oxidative stress caused synoviocytes to undergo a process of cell death of an apoptotic nature rather than necrotic. Mitochondrial injury occurred at an early stage, and the FITC-annexin-V-positive/propidium iodide-positive cells occurred later than the metabolic changes. DNA strand breaks were evident at 8 h and nuclear condensation at 24 h. No LDH activity was detected in culture supernatants. In our experimental conditions, alpha-tocopherol had little effect on stress damage; the antioxidant properties of this molecule did not affect the apoptosis caused by superoxide anions.

Apoptosis↗

Discrimination of osteoarthritic and rheumatoid human synovial cells in culture by nuclear image analysis.

Rheumatoid arthritic (RA) and osteoarthritic (OA) synovial cells in culture differ in their metabolic and proliferative behaviour. To assess links between these properties and nuclear changes, we used image analysis to study chromatin texture, together with nuclear morphometry and densitometry of OA and RA cells in primary culture. Chromatin pattern at the third day (D3) was heterogeneous and granular with chromatin clumps whereas at the final stage (D11) of culture a homogeneous and finely granular chromatin texture was observed. This evolution indicates global chromatin decondensation. These characteristics were more marked for RA than for OA nuclei. At each culture time, RA nuclei could be discriminated with high confidence from OA ones from parameters evaluating the organization of the chromatine texture. Nuclear image analysis is thus a useful tool for investigating synovial cell biology.

Arthritis, Rheumatoid↗

Markers of oxidative stress in fit, health-conscious elderly people living in the Paris area. The Research Group on Ageing (GERBAP)

Lipid peroxidation index and antioxidant indicators were assessed by biochemical means in 193 healthy elderly volunteers (103 men and 90 women), ages 70-89 y and living freely in the Paris area. Lipid peroxidation index was in the same range as in young adults. Zinc, copper, and selenium levels were satisfactory and similar to those in young adults, though the range of copper values tended to be higher. Copper and selenium levels were higher in elderly women than in men. However, for selenium values this sex-related difference disappeared in elderly volunteers > 75 y. Copper-zinc-superoxide dismutase and glutathione peroxidase activities were similar to those in young adults, with no influence of sex or age. Vitamin E and total carotene, closely related to cholesterol levels, were satisfactory. Our findings show that markers of oxidative stress are not influenced by old age when good health and nutritional status are preserved, as in this selected population.

Adolescent↗

Methodological considerations on Feulgen-staining applied to cells in primoculture: the model of osteoarthritic synovial cells.

Human synovial cells in primoculture are an interesting model for the study of articular joint diseases and anti-rheumatic drugs. Based on results obtained by image cytometry of Feulgen-stained nuclei, we describe the heterogeneity of synovial cell populations and their progression during culture time in primoculture. Using the hydrolysis properties of the Feulgen reaction and their variations dependent on fixatives, we demonstrate the high acid-lability of the condensed chromatin observed in short term cultured nuclei compared to the acid-resistance of decondensed chromatin in long term cultured nuclei; these variations being probably induced by modifications in the molecular supra-organisation of chromatin during the aging of a culture. Finally, due to the cellular heterogeneity of the biological model and its evolution during culture progression, technical compromises are proposed to obtain optimal Feulgen staining, using Böhm-Sprenger fixative and a 1 h hydrolysis by 6 M HCl at 20 degrees C.

Aged↗

[Reference intervals and biological profile in a group of healthy elderly population in the Paris region].

The superimposition of pathological processes on ageing-related metabolic changes makes the interpretation of laboratory data difficult in the elderly. Therefore, in order to establish reference values of anthropometric, hematological and biochemical variables, we have carefully selected fit, health-conscious elderly subjects on the basis of clinical and biological criteria. We observed a trend for a wider range of values than in young adults. For some variables, the values were shifted down (eg: albumin, vitamin D) or up (eg: glucose, urea, cholesterol, ferritin), as a result of slow metabolic changes or progressive functional decline of different organs. The high prevalence of hypovitaminosis D was worthy of note, particularly in women, suggesting a high risk of deficiency.

Aged↗

Extensive laboratory assessment of nutritional status in fit, health-conscious, elderly people living in the Paris area. Research Group on Aging.

OBJECTIVE: Nutritional status-related biological indexes were measured in fit, health-conscious elderly subjects in order to establish reference values for people over 70 years. SUBJECTS: 103 men and 90 women aged 70-89 years living freely in the Paris area volunteered to participate. METHODS: Nutritional status was assessed by anthropometric and biochemical methods. RESULTS: Serum protein and amino acid status was similar to that of young adults, with only 5.2% of the elderly subjects showing transthyretin concentrations < 0.20 g/L, as well as decreased essential amino acid levels. Iron status, assessed in terms of serum and erythrocyte ferritin levels, total iron binding capacity and erythrocyte protoporphyrin tended to be satisfactory, but iron depletion was detected in 8.8% of the subjects. Serum ferritin levels were elevated in 19.7% of the subjects. Folate and vitamin B12 status was satisfactory, while hypovitaminosis D was observed in 48.2% of cases. CONCLUSION: Our findings suggest that, in aging uncomplicated by disease, nutritional status is similar to that in younger adults, although the range of values tended to be wider, with a higher risk of certain nutrient deficiencies.

Aged↗

[Updating of relative data on tocopherols in clinical biochemistry].

The working group on lipophilic vitamins of the FSBC has reviewed current knowledge in the field of tocopherols and tried to summarize the most important and recent aspects that may be useful to clinical practitioners. The molecular structure of tocopherols and tocotrienols, their biogenesis, their analysis in foods, their metabolism in humans, their measurement in biological fluids, and the organism's needs and dietary requirements are reviewed. Their main functions as antioxidants and free radical scavengers are described at the molecular, ultra-structural, cellular and organ levels. The interest of these vitamins in three pathologies in which oxidative-stress has been implicated (atherosclerosis, cancer, kidney failure) is discussed.

Arteriosclerosis↗

Semi-automated assay of erythrocyte Cu-Zn superoxide dismutase activity.

A semi-automated enzymatic colorimetric method for determining Cu-Zn superoxide dismutase (SOD) in erythrocytes using an FP9 parallel analyzer is described. The method is based on the reaction described by McCord and Fridovich (xanthine/xanthine oxidase, ferricytochrome C), which permits kinetic measurements to be determined colorimetrically for the assay of enzyme activity. The coefficients of variation for within- and between-run analyses were less than 6%. The limit of linearity is 3.5-times the mean value of the normal range while recovery of added SOD ranged from 91 to 120%. The method, which is both reliable and simple, allows rapid, simultaneous measurements of multiple samples.

Adult↗

[Free radicals in clinical biology. Origin, pathogenic effect and defense mechanisms].

Free radicals are chemical species with an unpaired electron on their outer orbit. This review discusses the various endogenous and exogenous sources of free radicals; toxicity of free radicals, especially for DNA and cell membranes; a number of pathophysiologic states related to overproduction of free radicals; the natural protective systems--involving enzymes or scavengers--which prevent free radical-induced cell injury, and therapeutic trials of antioxidants for improving protection against free radicals in a number of conditions.

Arteriosclerosis↗

Influence of sex and age on vitamin A and E status.

Vitamins A and E were determined in the serum of 80 free-living healthy elderly subjects and in 80 healthy younger adults. Mean values and normal ranges were established for both groups and the influence of sex and age studied. We found a significantly lower level of vitamin A in the elderly men and women and a higher level of vitamin E in elderly women, relative to their younger counterparts. These differences may be related to life-style and age-associated physiological changes and justify the use of age-corrected standard values.

Aged↗

Free erythrocyte protoporphyrin assay in the diagnosis of iron deficiency in the anemic aged subject. A prospective study of 103 anemic patients.

We determined the relative value of the free erythrocyte protoporphyrin (FEP) assay compared to those of total iron-binding capacity (TIBC) and serum ferritin in the diagnosis of iron deficiency in a population of elderly anemic subjects. One hundred and three patients, 65 to 98 years old (mean +/- SD: 81.5 +/- 8.8), with hemoglobin levels of less than 110 milligrams (mean +/- SD: 97 +/- 12, range 53-109) were included in the study. In the patients with iron-deficiency anemia due solely to chronic bleeding, mean values for the three parameters were highly different from those in patients without chronic bleeding. In the patients with anemia due to an association of chronic bleeding and chronic inflammation, the mean FEP value was very significantly different (p less than 0.001) from that in the patients with chronic inflammation but without bleeding, whereas this was not the case for TIBC or serum ferritin. The sensitivity of FEP in the diagnosis of iron deficiency due to chronic bleeding in this population of anemic subjects was 60% (specificity 90%), compared to 13% (specificity 96%) for TIBC and 20% (specificity 100%) for serum ferritin. The FEP assay thus emerges as being highly suitable for the diagnosis of iron-deficiency anemia in the elderly subject, particularly when bone marrow is not examined.

Aged↗

Effects of human recombinant IL-1 beta on rheumatoid and non rheumatoid human synovial cell growth.

The growth of adherent synovial cells passaged once was studied in response to human recombinant interleukin 1 (hr IL-1) beta. Human synovial cell cultures were established from tissues obtained during therapeutic joint surgery for patients with rheumatoid arthritis (rheumatoid synovial cells, RSC) or non inflammatory rheumatic diseases (non rheumatoid synovial cells, NRSC). The effect of IL-1 beta (0.1 to 10 ng/ml) on the time course of proliferation showed that values for DNA synthesis and cell numbers in RSC cultures were higher than in NRSC cultures. Similarly, untreated control RSC cultures grew more quickly than NRSC. These results demonstrate that RSC, which are continuously stimulated by IL-1 beta produced in the rheumatoid pannus in vivo, have a higher capacity for proliferation than NRSC but are less responsive to IL-1 beta. A dose-response curve of proliferation was established 72 hrs. after the addition of IL-1 to the medium. The stimulating effect of IL-1 beta (0.001 to 10 ng/ml) was dose-dependent in both RSC and NRSC and reached a plateau at 10 ng/ml; the response of NRSC was stronger than that of RCS.

Arthritis, Rheumatoid↗

Comparative proliferation of non-rheumatoid and rheumatoid human synovial cells.

While normal synovial membrane cells have a very long doubling time, rheumatoid arthritis increases cell turn-over leading to the formation of a pannus. We studied the comparative proliferative behaviour in culture of synoviocytes of rheumatoid (RA) and non-rheumatoid (NR) origin in order to evaluate the usefulness of this model to investigate the drugs used in the treatment of inflammatory diseases. First-passage cultures of cells from patients with clinically defined non-inflammatory joint disease or rheumatoid arthritis were observed for 8 days. In the presence of various combinations of supplemented media, 3H-thymidine incorporation, protein content and cell density were assessed. In addition to a relationship between the fetal calf serum (FCS) concentration and cell growth, it was found that RA cells proliferated more rapidly than NR cells. In 1% FCS, protein content and cell density increased in RA cultures whereas NR synoviocytes accumulated in the quiescent phase. In 5% and 10% FCS, RA cells responded more strongly than NR in terms of protein and DNA synthesis and cell division. After 48 hours of relative FCS deprivation, NR cells abruptly started to proliferate; the response of RA cultures was delayed, but the synoviocytes quickly reached preconfluence.

Animals↗

An epidemiological and clinical study of transaminase levels and hepatitis B antibodies in 1,100 blood donors.

In order to provide epidemiological and clinical information on surrogate testing of blood donations, the respective prevalences of serum hepatitis B virus (HBV) markers and elevated transaminase levels were studied in 1,100 blood donors according to their geographic origin and socioeconomic level. The frequency of serum HBV markers varied as a function of HBV endemicity in the country of origin; however, it was inversely correlated (p less than 0.05) to the socioeconomic level of the donors, even in those originating from countries of low HBV endemicity. There was no association between serum HBV markers and the increased transaminase level which was observed in 48 (4.3%) donors. Twenty-five of these accepted further clinical evaluation. A diagnosis appeared probable in 12 of the 25: alcohol in 5; drugs in 6; non-A, non-B hepatitis in 1. Seven of the remaining 13 subjects were more than 25% above ideal body weight. Transaminase activities determined at the time of clinical assessment were normal in 14. In addition, serum HBV DNA was found in 5 of 247 donors, even in the absence of any usual HBV marker and/or hypertransaminasemia. This could account for the few cases of B and B-like posttransfusion hepatitis which are known to still occur despite careful HBsAg screening of blood donors.

Biomarkers↗

[Determination of erythrocyte protoporphyrin by a spectrofluorometry method].

Erythrocyte protoporphyrin (EP) measurement is useful for the diagnosis of protoporphyrin, iron deficiency or lead poisoning. The authors described a manual procedure for the spectrofluorimetric determination of EP. Erythrocytes were used, instead of whole blood. The following steps were performed: treatment with celite suspension, extraction using ethylacetate/acetic acid, estimation of the fluorescence of protoporphyrin IX extracted in HCl. Analytical results are following: a low detection limit (0.045 mumol/l), a linear response up to 2 mumol/l, within run and day-to-day precision respectively better than 3.5 p. cent and 5.8 p. cent. The procedure with predilution led to no significant difference with the spectrophotometric reference method (student t-test, t: 0.85) up to 42 mumol/l. Concentrations of EP according to age were studied for children (0.0470-1.000 mumol/l), middle-aged subjects (0.390-0.880) and elderly subjects (0.340-1.040). The proposed method is accurate, rapid and available for routine measurements.

Adult↗

The biological effects of retinoids on cell differentiation and proliferation.

The retinoids are the natural and synthetic analogues of retinol or vitamin A. These molecules are able to modulate differentiation and proliferation processes in several cell types. The presence of retinoids is essential for inducing or maintaining the differentiation of epithelial cells. On the other hand, when excess retinol is added to the culture medium, the differentiation of some mesenchymal cells is impaired. Retinoids also promote the differentiation of carcinoma cells of various origins: embryonal carcinoma, leukaemic and melanoma cells. While their effect on the proliferation of normal cells appears variable, these molecules inhibit the growth of cells treated with a tumoural promoter, or spontaneously transformed cells, and they prevent tumour promotion. Various mechanisms of action might be involved: retinoids could act at the level of the genome with or without the participation of their binding proteins. They might also influence glycoconjugate biosynthesis and interact, through certain glycosylation reactions, with growth factor receptors. The role of vitamin A and its structural analogues in cell differentiation and growth is of great therapeutic interest.

Animals↗