Papers by Lenita De Freitas Tallarico
Empoderamento feminino em Taboão da Serra: as percepções de três mulheres da cidade que lutam pel... more Empoderamento feminino em Taboão da Serra: as percepções de três mulheres da cidade que lutam pelos direitos de todas nós.
Molluscan Research, 2015
ABSTRACT Publication details, including instructions for authors and subscription information: (2... more ABSTRACT Publication details, including instructions for authors and subscription information: (2015): Spermatozoan ultrastructure and mitochondrial gene sequence of Caryocorbula caribaea (d'Orbigny, 1853) (Corbulidae: Bivalvia), a species with plasticity in shell morphology, Molluscan Research,
Despite the mollusks being the second largest group in kingdom Animalia, they have not been consi... more Despite the mollusks being the second largest group in kingdom Animalia, they have not been considered in environmental risk assessment so far, mainly due to the lack of standardized protocols. In this sense, the gastropods, with abundant species widely distributed in aquatic environments, have been employed in water and sediment quality assessments due their clear sensitivity to chemical compounds,
as pollution indicators for different substances. Acute and chronic toxicity tests have been mostly used in ecotoxicological protocols to evaluate potential effects of contaminants on natural populations. However, with the need to assess potential sublethal hazards to ecosystems of pollutants at low concentrations, environmental monitoring programs have encouraged analyzing effects on gametes, fertilization,
reproduction and embryo-larval development. Furthermore, among the myriad of chemicals reaching the environment, some compounds can directly affect the reproductive potential through induction of mutations in germ cells and vulnerable embryos. This work discusses some case studies of standardization assays with freshwater snails, especially good organisms for laboratory and in situ monitoring studies, to be
considered for regulatory environmental agencies. In that context, this work also shows the prospects for using gastropods in monitoring freshwater environments in Latin America.
On 18 December 2014, the Ministry of Environment of Brasil published the “Official National List ... more On 18 December 2014, the Ministry of Environment of Brasil published the “Official National List of Fauna Threatened with Extinction” (MMA, 2014a) and the “Official National List of Fauna Threatened with Extinction-Fish and Aquatic Invertebrates” (MMA, 2014b). This work was linked to the review of the continental fauna (freshwater and terrestrial) threatened with extinction, coordinated by the Chico Mendes Institute for the Conservation of Biodiversity (ICMBio) (Santos & Carvalho, 2014). This review covered 12,256 species evaluated by 1,383 specialists
A protocol combining acute toxicity, developmental toxicity and mutagenicity analysis in freshwat... more A protocol combining acute toxicity, developmental toxicity and mutagenicity analysis in freshwater snail Biomphalaria glabrata for application in ecotoxicological studies is described. For acute toxicity testing, LC50 and EC50 values were determined; dominant lethal mutations induction was the endpoint for mutagenicity analysis. Reference toxicant potassium dichromate (K2Cr2O7) was used to characterize B. glabrata sensitivity for toxicity and cyclophosphamide to mutagenicity testing purposes. Compared to other relevant freshwater species, B. glabrata showed high sensitivity: the lowest EC50 value was obtained with embryos at veliger stage (5.76 mg/L). To assess the model applicability for environmental studies, influent and effluent water samples from a wastewater treatment plant were evaluated. Gastropod sensitivity was assessed in comparison to the standardized bioassay with Daphnia similis exposed to the same water samples. Sampling sites identified as toxic to daphnids were also detected by snails, showing a qualitatively similar sensitivity suggesting that B. glabrata is a suitable test species for freshwater monitoring. Holding procedures and protocols implemented for toxicity and developmental bioassays showed to be in compliance with international standards for intra-laboratory precision. Thereby, we are proposing this system for application in ecotoxicological studies.
Studies on mutagenic agents have mostly focused on potential effects in humans. Despite the prese... more Studies on mutagenic agents have mostly focused on potential effects in humans. Despite the presence of mutagens in most of the pollution sources, the impact of mutagens on natural populations is still poorly understood. Mutagens in the environment may represent a long-term risk for ecosystems. Although exposure of aquatic organisms to genotoxic contaminants can pose a risk to human health via the food chain, there is also an ecological risk that may lead to heritable mutations and loss in the total genetic diversity. Mutagens can also directly affect the reproductive potential of populations by alterations in the fecundity and offspring viability caused by germ cell mutations. Among the biomarkers of germ cell effects, dominant lethal events have been used as convenient indicators of genetic damage since they are easily detectable. The so-called dominant lethal test with rodents has generally been considered one of the most important methods for the estimation of the mutagenic effects in humans. Freshwater mollusks of the genus Biomphalaria are good indicators for biomonitoring studies. The genus shows wide geographical distribution, has low dispersion and is easily collected. Other aspects make this system a good model for laboratory studies. The snails are easy to breed, need little space, can reproduce throughout the year under controlled conditions and have a short life-span: an egg-to-egg monitoring can be done in two months in B. glabrata. The dominant lethal assay was established in B.glabrata to evaluate mutagenic effects on germ cells by using a similar approach to that used in the test in rodents. Albinism was used as genetic marker to adapt the test for Biomphalaria, since the animal is a simultaneous hermaphrodite and reproduces by self- and cross-fertilization. Adult wild-type snails are exposed for ten to 30 days to the test agent in aqueous solutions. The range of concentrations is defined in preliminary experiments. After the end of the exposure, animals are crossed with albino snails at different intervals to evaluate the effects in the germ cells at the different stages of spermatogenesis. The analysis of lethal effects in the heterozygous offspring indicates the induction of mutations on germ cells of the exposed wild-type snails. Dominant lethal test in B. glabrata can be an useful tool to predict ecological changes in biomonitoring studies. Germ cell effects are biomarkers of great value in determining the implications for ecosystems of exposure to pollution since they reflect changes that affect the overall reproductive capability.
O aumento demográfico e o desenvolvimento industrial geram contaminação aos recursos hídricos mui... more O aumento demográfico e o desenvolvimento industrial geram contaminação aos recursos hídricos muito acima da sua capacidade de autodepuração. A agência responsável pelo monitoramento ambiental, CETESB, prioriza 27 locais para abastecimento de água na região do Alto Tietê. Poucos são os dados de toxicidade disponíveis em Estações de Tratamento de Esgotos em São Paulo. Este trabalho avaliou efeitos agudos de 5 amostras de afluentes e efluentes da ETE Suzano coletadas entre Setembro de 2005 e Março de 2008 em Daphnia similis e Vibrio fischeri. Os resultados mostraram que para D. similis a toxicidade foi reduzida totalmente pelo tratamento, enquanto que ensaios com V. fischeri resultaram em toxicidade remanescente e cuja eficiência média foi de 57,90%. Comparação entre estudos revelaram melhor situação atual, refletindo esforços da Cia. de Saneamento Básico do Estado de São Paulo (SABESP) no controle de recebimento de efluentes e na manutenção da operação da ETE.
Freshwater snails of the genus Biomphalaria play a major role as intermediate hosts of Schistosom... more Freshwater snails of the genus Biomphalaria play a major role as intermediate hosts of Schistosoma mansoni, the etiologic agent of schistosomiasis. While Biomphalaria spp. control by molluscicides is one of the main strategies to reduce the snail population in infected areas, there are few effective molluscicides commercially available. Natural products may be considered as potentially useful and safe molluscicides. We have evaluated the molluscicidal activity of 12 extracts from ten marine organisms on adult and embryonic stages of Biomphalaria glabrata. Only extracts of the red algae Liagora farinosa and of the sponge Amphimedon viridis presented molluscicidal activity. Lethal concentration (LC) 50 values obtained were 120 μg/mL for L. farinosa CH 2 Cl 2 extract (apolar fraction) and 20 μg/mL for A. viridis extract and halitoxin. The polar alga fraction and halitoxin had no effect on B. glabrata embryos. The algae apolar fraction was active on B. glabrata in all embryonic development stages, with LC 50 values for blastulae at 42 μg/mL, gastrulae at 124 μg/mL, trochophore at 180 μg/mL, and veliger at 222 μg/mL. This is the first report of extracts from marine organisms which presented molluscicidal activity.
Mutation Research-genetic Toxicology and Environmental Mutagenesis, 2004
The dominant lethal effects of gamma radiation of 60 Co in the snail Biomphalaria glabrata were s... more The dominant lethal effects of gamma radiation of 60 Co in the snail Biomphalaria glabrata were studied. Three groups of 13 wild-type snails were irradiated with single doses of 2.5; 10 and 20 Gy. Crossings were carried out at intervals of 7, 17, 23, 30 and 36 days after irradiation. The dominant lethal effect was observed only at the first crossing occurring 7 days after irradiation with 2.5 Gy. With 10 and 20 Gy, the induction of lethal mutations was detected at 7, 17 and 23 days after irradiation; a dose-response effect was observed. The effect was stronger 7 days after irradiation, decreasing in the succeeding crossings up to 30 days. Cell-killing effects on germ cells were detected in the crossings at 23 days and 30 days after irradiation with 20 Gy. After 36 days, frequencies of malformations resumed background levels; crossing rates partially recovered. These results show that gamma radiation affected all the stages of spermatogenesis. Germ cells at later phases were more sensitive to the mutagenic effect of radiation and the cell killing effects were observed on the youngest cells. This response was similar to the highly homogeneous pattern observed in widely different species and allowed us to estimate some parameters of spermatogenesis in B. glabrata.
Mutation Research-genetic Toxicology and Environmental Mutagenesis, 2008
The single cell gel eletrophoresis or the comet assay was established in the freshwater snail Bio... more The single cell gel eletrophoresis or the comet assay was established in the freshwater snail Biomphalaria glabrata. For detecting DNA damage in circulating hemocytes, adult snails were irradiated with single doses of 2.5, 5, 10 and 20 Gy of 60 Co gamma radiation. Genotoxic effect of ionizing radiation was detected at all doses as a dose-related increase in DNA migration. Comet assay in B. glabrata demonstrated to be a simple, fast and reliable tool in the evaluation of genotoxic effects of environmental mutagens.
The dominant lethal effects of gamma radiation of 60 Co in the snail Biomphalaria glabrata were s... more The dominant lethal effects of gamma radiation of 60 Co in the snail Biomphalaria glabrata were studied. Three groups of 13 wild-type snails were irradiated with single doses of 2.5; 10 and 20 Gy. Crossings were carried out at intervals of 7, 17, 23, 30 and 36 days after irradiation. The dominant lethal effect was observed only at the first crossing occurring 7 days after irradiation with 2.5 Gy. With 10 and 20 Gy, the induction of lethal mutations was detected at 7, 17 and 23 days after irradiation; a dose-response effect was observed. The effect was stronger 7 days after irradiation, decreasing in the succeeding crossings up to 30 days. Cell-killing effects on germ cells were detected in the crossings at 23 days and 30 days after irradiation with 20 Gy. After 36 days, frequencies of malformations resumed background levels; crossing rates partially recovered. These results show that gamma radiation affected all the stages of spermatogenesis. Germ cells at later phases were more sensitive to the mutagenic effect of radiation and the cell killing effects were observed on the youngest cells. This response was similar to the highly homogeneous pattern observed in widely different species and allowed us to estimate some parameters of spermatogenesis in B. glabrata.
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Papers by Lenita De Freitas Tallarico
as pollution indicators for different substances. Acute and chronic toxicity tests have been mostly used in ecotoxicological protocols to evaluate potential effects of contaminants on natural populations. However, with the need to assess potential sublethal hazards to ecosystems of pollutants at low concentrations, environmental monitoring programs have encouraged analyzing effects on gametes, fertilization,
reproduction and embryo-larval development. Furthermore, among the myriad of chemicals reaching the environment, some compounds can directly affect the reproductive potential through induction of mutations in germ cells and vulnerable embryos. This work discusses some case studies of standardization assays with freshwater snails, especially good organisms for laboratory and in situ monitoring studies, to be
considered for regulatory environmental agencies. In that context, this work also shows the prospects for using gastropods in monitoring freshwater environments in Latin America.
as pollution indicators for different substances. Acute and chronic toxicity tests have been mostly used in ecotoxicological protocols to evaluate potential effects of contaminants on natural populations. However, with the need to assess potential sublethal hazards to ecosystems of pollutants at low concentrations, environmental monitoring programs have encouraged analyzing effects on gametes, fertilization,
reproduction and embryo-larval development. Furthermore, among the myriad of chemicals reaching the environment, some compounds can directly affect the reproductive potential through induction of mutations in germ cells and vulnerable embryos. This work discusses some case studies of standardization assays with freshwater snails, especially good organisms for laboratory and in situ monitoring studies, to be
considered for regulatory environmental agencies. In that context, this work also shows the prospects for using gastropods in monitoring freshwater environments in Latin America.