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Biomedical subjects

C Ponteziere

Publications and source records attributed to C Ponteziere.

7 recordsLinked to original sources
PubMed1999

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↗
PubMed1997

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↗
PubMed1991

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↗
PubMed1990

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↗
PubMed1990

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↗
PubMed1987

Aminotransferases in elderly people: influence of pyridoxal 5'-phosphate addition on the determination of serum aminotransferases in healthy elderly subjects.

Aspartate aminotransferase (ASAT) and alanine aminotransferase (ALAT) activity was measured in a group of 81 healthy subjects over 70 years of age and another of 180 younger persons, in order to investigate histograms and means of aminotransferase values in both groups and the variation in stimulation of these enzyme activities by pyridoxal 5'-phosphate (P5P) added in vitro. It was found that ASAT and ALAT mean values were significantly higher in both groups in the presence of P5P, than in the absence of P5P. ASAT and ALAT mean values obtained with and without P5P in old people were similar to those found in young subjects. In addition, mean stimulation percentages by P5P were identical in both groups.

Adolescent↗