RESUMO
Caiman latirostris is one of the two species of the order Crocodylia that inhabit Argentina and is considered a species of vital ecological and economic importance in the north-east of Argentina. In this region, pesticides are the most common contaminants in natural environments and wild caiman populations are subject to this contamination constantly. The aim of this study was to evaluate the effects the main pesticides used in the region: glyphosate (GLY), cypermethrin (CYP) and chlorpyrifos (CPF) -based formulations, as well as the mixture of them, on C. latirostris juveniles under semi-controlled condition of exposure (ex-situ) during 75 days. One hundred yearling caimans (10-month-old) were equally distributed into five experimental groups (20 animals per group): a negative control (NC -tap water), GLY 2% (Roundup® Full II formulation -RU), CYP 0.12% (Atanor® formulation), CPF 0.8% (Lorsban® formulation), and a mixture of the three pesticides (Mx3: GLY 2% + CYP 0.12% + CPF 0.8%). We applied early warning biomarkers to detect damage induced by these chemicals in peripheral blood: activity of the antioxidant enzymes catalase (CAT) and superoxide dismutase (SOD), analysis of lipid peroxidation (LPO) by the thiobarbituric acid reactive substances (TBARS), DNA damage and specific base oxidation through the standard and modified comet assay (CA), chromosome damage by micronucleus (MN) test and other nuclear abnormalities (NAs), hematological and growth parameters. Results showed a statistically significant increase in MN and NAs frequency, DNA damage, with an important contribution of base oxidation for all exposed groups compared to the NC. Total white blood cells count (TWBCC), and growth parameters showed effects mainly at the Mx3. The principal component analysis (PCA) demonstrated more sensitivity for biomarkers associated to genetic damage, including base oxidation to DNA than LPO, antioxidant enzyme modulation, immunotoxicity or growth parameters, to detect pesticides effects, applied under conditions similar to that found in natural environments.
RESUMO
Agricultural expansion and the consequent use of pesticides lead to the loss and fragmentation of natural habitats of several wild species. Then, many species are inevitably exposed to a wide amount of pesticide formulations. Glyphosate (GLY)-based formulations are the most used herbicide, whereas two of the most employed insecticides are chlorpyrifos (CPF) and cypermethrin (CYP). The aim of this study was to evaluate genotoxicity, oxidative damage, and the modulation of antioxidants defenses in peripheral blood of Caiman latirostris after embryonic exposure to pesticide formulations and their mixtures. Pesticides concentrations employed were equivalent to those recommended in agricultural practices for application in soybean crops and a half of them: GLY: 2% and 1%; CYP: 0.12% and 0.06%; CPF: 0.8% and 0.4%. Two similar experiments (E1 and E2) were carried out in consecutive years, where C. latirostris eggs were exposed to pesticide formulations separately and in different mixtures through application on the incubation material. After hatching, blood samples were taken and genotoxicity and oxidative stress was evaluated through the micronucleus (MN) test, the modified comet assay, the lipid peroxidation (LPO) levels and the activities of catalase (CAT) and superoxide dismutase (SOD) antioxidant enzymes. The results indicated the presence of DNA damage, oxidation of purines and pyrimidines, and increased frequency of micronucleus (FMN) in the case of GLY, CYP, and CPF formulations exposure, as well as in all the mixtures tested, with respect to the control groups. Specifically, the results observed for the mixtures would indicate independent action or antagonism of the components for DNA damage and base oxidation (purines and pyrimidines) and a possible potentiation interaction for the FMN in two binary mixtures. However, there were not differences regarding lipid peroxidation, the activity of antioxidant enzymes and growth parameters. This study proved that the use of pesticide formulations at concentrations used in the field generate deleterious genetic effects on this species, then, exposure to them could threaten its survival and health status.
Assuntos
Jacarés e Crocodilos/metabolismo , Dano ao DNA , Micronúcleos com Defeito Cromossômico/induzido quimicamente , Óvulo/efeitos dos fármacos , Estresse Oxidativo/efeitos dos fármacos , Praguicidas/toxicidade , Jacarés e Crocodilos/sangue , Jacarés e Crocodilos/genética , Animais , Antioxidantes/metabolismo , Argentina , Ensaio Cometa , Peroxidação de Lipídeos/efeitos dos fármacos , Peroxidação de Lipídeos/genética , Testes para Micronúcleos , Óvulo/crescimento & desenvolvimento , Estresse Oxidativo/genéticaRESUMO
BACKGROUND: Gaucher disease (GD) is a lysosomal storage disorder characterized by a deficiency of the lysosomal acid ß-D-glucosidase (GBA). The aim of this study was to develop an ultramicro-fluorometric assay based on the method of Chamoles et al. for determining GBA activity in dried blood spots on filter paper (DBS). METHODS: The assay used 3-mm diameter blood spot and 8 mmol/l of 4-methylumbelliferyl-ß-D-glucoside as enzymatic substrate. The reaction occurred in plates incubated at 37°C for 20 hours and the enzyme activity was expressed in µmol hydrolysed substrate/l blood/h. The fluorescence of the enzyme product was automatically measured in a fluorometer-photometer reader (SUMA Technology). RESULTS: The intra and inter-assay coefficients of variation were lower than 9 and 12%, respectively, and the recovery range was 97-109%.Three patients with GD were correctly diagnosed using the ultramicroassay. Healthy newborn DBS samples (n = 3003) from the National Neonatal Screening Program were analyzed, and the mean GBA activity was 5.7 µmol/l blood/h. Our assay showed high Pearson (n = 26; r = 0.99) and concordance correlations (ρc = 0.99) with the traditional method described by Chamoles et al. CONCLUSIONS: The analytical performance characteristics of our ultramicro-fluorometric assay suggest that it can be used in the diagnosis of GD in newborns and adults.
Assuntos
Teste em Amostras de Sangue Seco , Fluorometria , Doença de Gaucher/enzimologia , Triagem Neonatal , Coleta de Amostras Sanguíneas , Cuba/epidemiologia , Teste em Amostras de Sangue Seco/métodos , Feminino , Fluorometria/métodos , Doença de Gaucher/epidemiologia , Humanos , Recém-Nascido , Masculino , Reprodutibilidade dos Testes , Sensibilidade e EspecificidadeRESUMO
OBJECTIVES: This study sought to determine whether a culturally relevant health message would promote stair use in a predominantly Hispanic community. METHODS: Observations of stair, elevator, and escalator use were collected over a 6-month period at 4 sites throughout the city of El Paso, Tex. The efficacy of individual and family health promotion signs was tested. RESULTS: Stair use increased in response to both individual and family promotion health messages, and use varied widely by intervention site. CONCLUSIONS: These results underscore the importance of considering the physical characteristics of the environments targeted for health promotion campaigns.