Browsing by Author "CARDENAS, L"

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    DEGRADATION OF TRICHLOROPHENOLS BY ALCALIGENES-EUTROPHUS JMP134
    (1995) CLEMENT, P; MATUS, V; CARDENAS, L; GONZALEZ, B
    The degradation of chlorophenols by Alcaligenes eutrophus JMP134 (pJP4) was studied. The strain grew on 2,4,6-trichlorophenol or 2,4,6-tribromophenol as the sole carbon and energy source. Complete degradation of 2,4,6-trichlorophenol was confirmed by chloride release and gas chromatography analysis of supernatants from growth cultures. The 2,3,5-, 2,3,4-, 2,3,6- and 2,4,5-isomers of trichlorophenol did not support growth. However, up to 40% of 2,4,5-trichlorophenol was mineralized during growth of A. eutrophus on chemostats fed with either phenol (0.4 mM) or 2,4,6-trichlorophenol (0.4 mM) plus 2,4,5-trichlorophenol (0.1 mM). Growth on 2,4,6-trihalophenols was also observed in A. eutrophus JMP222, the strain lacking pJP4, suggesting that this new degradative ability reported for A. eutrophus is not related to pJP4 encoded catabolic functions.
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    HYPOLIPEMIC DRUGS ARE ACTIVATED TO ACYL-COA ESTERS IN ISOLATED RAT HEPATOCYTES - DETECTION OF DRUG ACTIVATION BY HUMAN LIVER HOMOGENATES AND BY HUMAN PLATELETS
    (1992) BRONFMAN, M; MORALES, MN; AMIGO, L; ORELLANA, A; NUNEZ, L; CARDENAS, L; HIDALGO, PC
    The formation of acyl-CoA esters of the hypolipidaemic peroxisome proliferators clofibric acid, ciprofibrate and nafenopin was studied in isolated rat hepatocytes. The concentration of ciprofibroyl-CoA in the liver of ciprofibrate-treated rats was in the range of 10-30-mu-M. The three drugs formed acyl-CoA esters when incubated with isolated hepatocytes. Their formation was saturable and reached a plateau after 30 min incubation. Maximal intracellular concentrations of ciprofibroyl-CoA and clofibroyl-CoA (100-mu-M and 55-mu-M respectively) were attained at 0.5 mM of the free drugs in the incubation medium, whereas for nafenopin-CoA, the maximal intracellular concentration (9-mu-M) was reached at 1 mM-nafenopin. At low concentrations of the hypolipidaemic compounds in the incubation medium a significant proportion of the total intracellular drug was present as its acyl-CoA ester (25-35% for ciprofibrate). When isolated hepatocytes were incubated with a ciprofibrate concentration comparable with that observed in the blood of drug-treated rats (0.1 mM), ciprofibroyl-CoA attained an intracellular concentration similar to that previously observed in the liver of treated rats. The formation of ciprofibroyl-CoA by isolated rat hepatocytes was stimulated by the addition of carnitine and partially inhibited by the addition of palmitate. Further, it was shown that human liver homogenates synthesized ciprofibroyl-CoA at a rate similar to that observed for rat liver homogenates. Solubilized human platelets also formed ciprofibroyl-CoA, although at a rate two orders of magnitude lower than that of liver. The results support the view that acyl-CoA esters of hypolipidaemic peroxisome proliferators may be the pharmacologically active species of the drugs.
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    THE EFFECT OF SIDE-CHAINS ON THE PARTIAL SPECIFIC VOLUMES OF POLY(ORTHO-ALKYLPHENYL METHACRYLATE)S AND POLYDIITACONATES
    (1988) GARGALLO, L; RADIC, D; HAMIDI, N; CARDENAS, L; HORTA, A; HERNANDEZFUENTES, I