The aim of this study was to see whether aluminum (Al) and lead (Pb) salts are toxic for cultured human fibroblasts under different experimental conditions, in the controllable situation offered by cell cultures. Cell survival and membrane lipid peroxidation served as markers of Al and Pb toxicity. Evaluation of the living cells was carried out using a colorimetric method, the mitochondrial reduction of 1-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT). Lipoperoxidation assay was performed on whole cell homogenates by measuring thiobarbituric acid-reactive substances (TBARS) produced after incubation with ascorbic acid-ferrous sulfate. Al(III) and Pb(II) salts (300 microM) produce a considerable decrease in cell survival after an exposure period of 4d, evident with the three fetal calf serum concentrations in the culture media: 2, 5, and 10%. Taking into account in vitro cell aging, the cytotoxic effects of Al(III) and Pb(II) are greater in senescent fibroblasts than in young cells. Lead-induced cytotoxicity is higher than Al-induced cytotoxicity. A mechanism that contributes to cellular toxicity is membrane lipid peroxidation; our results demonstrate that Al(III) and Pb(II) ions, 400 microM, exert an antioxidant-like effect or a pro-oxidant action on cell membranes depending on exposure time. We describe significant increases in TBARS formation associated with the presence of 400 microM Al(III) or Pb(II) salts in the culture media. Our study also revealed that these heavy metals induce a cell age-dependent action on membrane lipoperoxidation that is greater in senescent fibroblasts and this could have severe consequences for maintenance of cellular integrity.

Aluminum Compounds↗

PubMedDate not supplied

[A controlled, double-blind, randomized pilot clinical trial of nicardipine as compared with a placebo in patients with moderate or severe head injury].

INTRODUCTION: One of the factors involved in the occurrence of ischemic cerebral lesions following head injury is cerebral vasospasm. We analyze the effect of intravenous nicardipine on the prevention and treatment of posttraumatic cerebral vasospasm. PATIENTS AND METHODS: We made a placebo-controlled, randomised, double-blind pilot study of the effect of nicardipine (intravenously 5 mg/hour for one week) on patients with moderate or severe head injury who presented with cerebral vasospasm, defined as an average Doppler flow velocity (DFV) of 100 cm/second or more. The main variable assessed was the evolution of the DFV and the secondary criteria were the evolution of the arterial blood pressure, coma scales, the findings on the Glasgow Coma Scale and the safety of the drug. RESULTS: Eleven patients were included in each homogeneous group. The DFV was found to have become normal on the first day of treatment with nicardipine and on the third day with the placebo (p = 0.023). During the first day of treatment the percentage of cerebral hemispheres diagnosed as having suspected spasm was 11.1% for nicardipine and 64.3% for the placebo (p = 0.02881). The average time for recovery (DFV < 100 cm/second) was 3.33 days with the placebo and 1.22 days with nicardipine (p = 0.0039). The patients treated with nicardipine had 8.89 times more chance of recovery from vasospasm. The incidence of adverse effects was greater with the placebo (p = 0.014). CONCLUSION: Nicardipine is effective in the reversal and prevention of increased Doppler flow velocity in patients with moderate or severe head injury.

Adult↗