Investigating the relationship between embryotoxic and genotoxic effects of benzo[a]pyrene, 17alpha-ethinylestradiol and endosulfan on Crassostrea gigas embryos.

Genotoxicity biomarkers are widely measured in ecotoxicology as molecular toxic endpoints of major environmental pollutants. However, the long-term consequences of such damage still have to be elucidated. Some authors have suggested that the accumulation of unrepaired DNA lesions could explain the embryotoxicity of certain chemical pollutants. As embryotoxicity exerts a direct impact on the recruitment rate, genotoxicity could be closely related to disturbances of ecological concern and produce a possible impact upon population dynamics. The aim of the present work was to study the genotoxicity and the embryotoxicity of three relevant pollutants for oyster embryos: the polycyclic aromatic hydrocarbon, benzo[a]pyrene (BaP), the synthetic estrogenic hormone, 17alpha-ethinylestradiol (EE2), and the organochlorine pesticide, endosulfan (ES). For each substance, gamete fertilization was performed and embryo development followed in contaminated reference seawater. Following exposure, embryotoxicity was evaluated by calculating the percentage of abnormal D-larvae obtained at 20 h development. Genotoxicity was measured in parallel by conducting a comet assay on enzymatically dissociated cells of pre-shelled larvae (16 h development). The oxidized DNA base, 8-oxodGuo, was also measured by HPLC coupled to electrochemical detection. For each contaminant, the relationship between genotoxicity and embryotoxicity was then studied to check for the possible significance of genotoxicity in the population dynamics of marine bivalves from polluted areas. For BaP, embryotoxicity and DNA strand breakage were both observed from the lowest tested concentration of 0.2 nM. Induction of 8-oxodGuo was significant from 20 nM. Endosulfan exposure resulted in similar effects for oyster embryos but from higher concentrations and followed a concentration-dependent manner. Embryotoxicity and genotoxicity in terms of DNA strand breaks were observed for endosulfan from 300 and 150 nM, respectively. No change in 8-oxodGuo level was observed following endosulfan exposure. EE2 displayed no toxic effect for oyster embryos within the range of tested concentrations (from 0.02 to 1.7 nM). Taking into account all the data collected during this study, a positive and significant correlation was demonstrated in oyster embryos between genotoxicity as measured by the comet assay and embryotoxicity.

Cytogenetic, developmental, and biochemical effects of aluminum, iron, and their mixture in sea urchins and mussels.

The present study was undertaken to evaluate the toxicity of aluminum sulfate, ferric chloride and their 1:1 mixture (Mix) on early development, fertilization and offspring quality in three sea urchins species (Sphaerechinus granularis, Paracentrotus lividus, Psammechinus microtuberculatus) and in mussels (Mytilus galloprovincialis). The endpoints were the following: a) larval malformations; b) developmental arrest; c) embryonic mortality; d) fertilization success; e) cytogenetic effects, and f) luminol-dependent chemiluminescence (LDCL). Overall data point to the induction of developmental defects in both sea urchin and mussel embryos following exposure of embryos to Al(III) or Fe(III) (10(-7) to 10(-6) M), whereas Mix caused varied effects vs. Al(III) or Fe(III) alone, from scarce or no additive effects (M. galloprovincialis and P. lividus) to a dramatic rise in embryolethality even at nominal levels of 10(-8) M (Ps. microtuberculatus).S. granularis sperm underwent a dose-dependent decrease in fertilization success following exposure to Al(III), or Fe(III), or Mix at levels ranging from 10(-8) to 10(-5) M. A significant increase of developmental defects was observed in the offspring of S. granularis sperm exposed to micromolar levels of the agents, suggesting an Al(III)- and Fe(III)-related transmissible damage to sperm. The cytogenetic analysis of Al(III)-, Fe(III)-, or Mix-exposed S. granularis embryos showed a significant increase in mitotic aberrations. A relevant feature of the observed cytogenetic damage included scattered chromosomes, suggesting cytoskeleton damage. The LDCL emission in S. granularis embryos showed a dose-related inhibition by agent levels ranging from 10(-7) to 10(-5) M; this held true for both spontaneous and, to a larger extent, for horseradish peroxidase (HRP)-activated LDCL. LDCL associated with fertilization was affected by Al(III), Fe(III) and Mix, with a time- and dose-related shift from stimulation to inhibition. The changes observed in LDCL emission suggested that the observed damage to embryogenesis, fertilization and mitotic activity may be related, at least partly, to alterations of the embryo prooxidant state. The present data point to developmental, cytogenetic and biochemical changes related to realistic levels of Al(III), Fe(III) and their mixtures, raising concern as to their environmental, occupational and iatrogenic exposures.

Efficacy and pharmacokinetics of Timentin in paediatric infections.

Twenty-four children, ten of whom had an infection due to ticarcillin-resistant, Timentin-sensitive bacteria, were treated with Timentin. A full clinical success was obtained in sixteen cases (13 pyelonephritis, nine of them due to ticarcillin-resistant, Timentin-sensitive Escherichia coli, two neonatal infections and one pneumonia). Four children were improved (1 bronchiectasis, 3 leukaemias), three were unassessable and one failure occurred with a staphylococcal urinary tract infection. A pharmacokinetic study was performed in three newborns (under three months) and ten children (mean age 3 years). Timentin was administered as four daily 30-min iv infusions. The mean dosage used in patients under three months was 225 mg/kg/d ticarcillin and 9 mg/kg/d clavulanic acid. In infants older than three months of age the mean dosage was 250 mg/kg/d ticarcillin and 16 mg/kg/d clavulanic acid. The pharmacokinetic results demonstrated similar serum concentrations of ticarcillin to those in earlier studies, and serum concentrations of clavulanic acid of 3.1 +/- 0.63 mg/l and 2.18 +/- 0.17 mg/l at 1 h and 2 h respectively after infusion in newborns. For children, at the same times, the serum levels were respectively 2.3 +/- 0.9 mg/l and 1.4 +/- 0.9 mg/l. The peak serum concentrations of clavulanic acid were the same in the two groups of dosages (4.7 mg/l), but the half-lives of clavulanic acid were 1.1 h in children older than three months and 1.8 h in infants younger than 3 months. The tolerance was good. Timentin may be useful as a first line antibiotic in infections in hospitalized children in the dosage described, as three or four injections daily, according to the age and the severity of the disease.