No abstract

The present study was carried out to examine the adverse hematotoxic and genotoxic effects of water nitrate pollution on male adult rats and the use of hyparrhenia hirta methanolic extract in alleviating these effects. Sodium nitrate (NaNO3 ) was administered to adult rats by oral gavage at a dose of 400 mg kg(-1) bw daily for 50 days, while hyparrhenia hirta methanolic extract was given by drinking water at a dose of 1.5 mg mL(-1) (200 mg kg(-1) bw). The NaNO3 -treated group showed a significant decrease in red blood cell count, hemoglobin and hematocrit and a significant increase in total white blood cell, in neutrophil and eosinophil counts. Platelet count, mean corpuscular volume, mean corpuscular hemoglobin, and mean corpuscular hemoglobin concentration remained unchanged in treated groups compared to those of controls. Meanwhile, the results showed a marked reduction in the antioxidant enzyme activities, such as superoxide dismutase, catalase, and glutathione peroxidase, along with an elevation in the level of lipid peroxidation and a reduction in the total glutathione content, indicating the induction of oxidative stress in the erythrocytes of NaNO3 -treated group. Interestingly, NaNO3 treatment showed a significant increase in the frequencies of total chromosomal aberrations, aberrant metaphases and micronucleus in bone-marrow cells. The oxidative stress induced by nitrate treatment might be the major cause for chromosomal rearrangements as free radicals leading to DNA damage. Hyparrhenia hirta methanolic extract appeared to be effective against hematotoxic and genotoxic changes induced by nitrate, as evidenced by the improvement of the markers cited above.

The aim of this study was to determine the effects of thiocyanate on thyroid function in weaned mice. At this developmental period, induction and reversibility of thiocyanate effects have not yet been studied. In the present work, adult female mice were given thiocyanate [SCN − (1 g L −1 )] in their drinking water from the 15 th day of pregnancy until either the 25 th (group B) or the 15 th day (group C) after parturition. During five days after weaning, water and food consumptions of treated mice (group B) were 42.2 ± 1.2% and 56.4 ± 0.9%, respectively, less than those of the controls (group A). On the sacrifice day (the 25 th day after birth), body weight, thyroid iodine content and thyroid hormone levels (FT 4 and FT 3 ) decreased by 10.4 ± 3.0%, 40.6 ± 2.3%; 18.7 ± 2.3% and 18.1 ± 1.3%, respectively. Plasma TSH increased by 30.6 ± 1.7% along with the hypertrophy of thyroid glands (52.6 ± 3.1%). We have observed a hypertrophy of follicle cells and a decrease in colloid volume within histological slides. After SCN − withdrawal (group C), partial or total recovery were noted in all parameters studied. We concluded that hypothyroidism effects added to the weaning event affected greatly thyroid function and behaviour of mice; these would be largely reversed by withdrawing thiocyanate treatment for a period of ten days.

L'analyse bactériologique des eaux de surface dans un effluent urbain et en milieu marin côtier montre une contamination saisonnière mais fréquente de ces eaux par les Aeromonas mobiles. L'évolution spatiale et temporelle des abondances de ces bactéries, en relation avec certains facteurs environnementaux, a été étudiée pendant un an dans le rejet final épuré et dans les eaux marines réceptacles de l'effluent. Ces bactéries présentent, dans les eaux lagunaires, des évolutions saisonnières identiques à celles des coliformes fécaux avec des densités élevées en période froide (moyenne : 29·106 UFC/100 mL) et faibles en période chaude (moyenne : 6·106 UFC/100 mL). L'abattement des abondances d'Aeromonas se trouve corrélé à une forte irradiation et à une faible turbidité.Le déversement des eaux de la station d'épuration dans les eaux marines côtières de la région n'induit pas globalement de modifications de la forme de comportement des bactéries témoins de contamination fécale. À l'opposé, l'évolution des abondances des Aeromonas spp. mobiles s'inverse pour devenir maximale en période chaude (moyenne : 56 CFU/100 mL pour S3) et minimale en période froide (moyenne : 5 CFU/100 mL pour S3). La salinité paraît responsable de la déstabilisation des séquences saisonnières des Aeromonas et de leur réduction à des concentrations non détectables dans les volumes d'eaux analysés.La présence de ces bactéries dans les effluents épurés, parfois à des concentrations supérieures à celles des coliformes fécaux, pose un problème d'intérêt sanitaire et montre clairement que les bactéries témoins de contamination fécale ne peuvent pas être prédictives de la présence ou de l'absence d'Aeromonas et, par conséquent, ne peuvent pas être considérées comme un bon indicateur de pollution.Bacteriological analyse of surface water in an urban effluent and in coastal marine environment showed a seasonal contamination of this water by motile Aeromonas. Spatial and seasonal changes of Aeromonas abundances were studied, in relation to several environmental factors, in the purified effluent and in seawater.The motile Aeromonas spp. and the fecal coliform distributions in the sewage treatment effluent showed the same seasonal cycles with a maximum occuring in winter (mean: 29·106 UFC/100 ml) and a minimum in summer (mean of 6·106 UFC/100 mL). The abatement of Aeromonas abundances was correlated with a strong irradiation and a low turbidity.In the coastal marine water, there was an inversion of the motile Aeromonas spp. cycle in comparison with that of fecal coliforms, with high levels in hot periods (mean: 56 CFU/100 mL for S3) and low levels in cold periods (mean of 5 CFU/100 mL for S3). Salinity appeared responsible for the destabilisation of the seasonal sequences of Aeromonas and their reduction with non detectable concentrations in water analysed volumes.The presence of these bacteria in the purified effluent, sometimes with concentrations higher than those of the fecal coliforms, poses a problem of health hazard and clearly show that fecal contam...