Toxicologia dos cosméticos

Although not desirable, cosmetic products can cause some adverse effects in me user. Such effects can be due bom to individual factors and by inadequate use. So, the safety evaluation must precede the placement of the cosmetic product in the market. Once the consumer has free access to cosmetic product, it must be safe in normal conditions or reasonably previsible of use. Historically the evaluation tests were accomplished with animals (in vivo) but, at the moment, some research centers have been adopting new alternatives (in vitro) in order to replace me tests with animals. This article emphasizes me necessity of accomplishing toxicity assays for personal hygiene products, cosmetics and perfumes, an also presents the tests in vivo and in vitro used, approaching the necessity of alternative methods to the assays in vitro in the evaluation of security of them.

Toxicologia e psicofarmacologia em biologia e programas de saúde para o ensino médio

Pós-graduação em Educação para a Ciência - FC

Da capacitação em toxicologia, psicofarmacologia e legislação na formação inicial de professores de ciências e biologia para a prevenção educacional ao uso abusivo de substâncias psicoativas

Pós-graduação em Educação para a Ciência - FC

Toxicologia reprodutiva de ratos adultos expostos ao 2,3,7,8-Tetraclorodibenzo-P-Dioxina (TCDD) in útero

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Clinical, cytogenetic and toxicological studies in rural workers exposed to pesticides in Botucatu, São Paulo, Brazil

Pesticidas podem causar mutações gênicas e aberrações cromossômicas em indivíduos expostos. Investigamos 24 trabalhadores expostos a pesticidas, nos quais foram executados exames clínicos e testes citogenéticos e toxicológicos. Dez indivíduos não expostos foram usados como controles. Dosagem toxicológica de cobre, zinco e manganês (metais encontrados em alguns pesticidas), dosagem de enzimas hepáticas (GOT, GPT, AP) e atividade de acetilcolinesterase foram executadas em 16 trabalhadores e oito controles. Nos trabalhadores expostos, os sintomas clínicos mais pertinentes foram digestão pobre, com sensação de plenitude após alimentação, olhos irritados, enxaqueca e fasciculações. O grupo exposto mostrou dosagem de manganês e atividade de acetilcolinesterase significativamente mais baixas, e nível significativamente mais alto de fosfatase alcalina. Estudos citogenéticos mostraram freqüências de aberrações cromossômicas significativamente mais altas no grupo exposto quando comparado ao grupo de controle. Embora usassem vestuário protetor contra névoa de pesticidas, o qual incluía calças de borracha, botas, luvas, máscara e chapéu, os resultados clínicos revelaram que os trabalhadores foram contaminados. Concluímos que estudos citogenéticos, toxicológicos, juntamente com exames clínicos, são importantes no controle da saúde do trabalhador, mesmo em condições de proteção.

Hematological parameters in Nile Tilápia, Oreochromis niloticus exposed to sub-letal concentrations of mercury

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Effects of experimental amitraz intoxication in cats

Este trabalho estudou os efeitos da intoxicação experimental por amitraz em 16 gatos, distribuídos, aleatoriamente, em dois grupos: grupo amitraz - animais receberam amitraz a 1,5% na dose de 1,0 mg/kg IV; e grupo controle - animais sem amitraz. Parâmetros fisiológicos sangüíneos, do sistema cardiorespiratório e de sedação foram aferidos até 360min. Perfil sangüíneo, uréia, creatinina, alanina aminotransferase e aspartato aminotransferase não foram afetados pelo amitraz. Sedação, perda de reflexos, hipotermia, bradicardia, bradiarritmias, hipotensão, bradipnéia, midríase, além de transitória hiperglicemia, hipoinsulinemia e diminuição dos níveis de cortisol, foram observados nos gatos experimentalmente expostos ao amitraz. Os efeitos alfa 2-adrenérgicos induzidos pela intoxicação por amitraz em gatos são muito similares aos mesmos efeitos relatados em outras espécies, contribuindo com mais informações dessa intoxicação para a toxicologia veterinária.

Clinical and epidemiological study of 27 poisonings caused by ingesting puffer fish (Tetrodontidae) in the states of Santa Catarina and Bahia, Brazil

Os baiacus ou peixes-bola podem ser venenosos devido à presença em seus tecidos corporais de Tetrodotoxina e/ou Saxitoxina, ambas potentes neurotoxinas. Os autores relatam 27 envenenamentos por ingestão da carne de baiacus. Os pacientes foram atendidos nos Centros de Toxicologia de Santa Catarina e da Bahia de 1984 a 2009. Os acidentes foram classificados em moderados (52%) e graves (33%), havendo dois óbitos. O diagnóstico precoce é fundamental no sentido de garantir suporte ventilatório aos pacientes.

Behavioural alterations provoked by prolonged calcitonin administration in rats

Present work investigated the effect of prolonged administration of salmon calcitonin, a hormone secreted by parafollicular cells from thyroid, on behavioural parameters of rats. Animals received calcitonin sc, 100 mUI/100 g of body weight, three times a week, during 50 days. Behaviour was assessed utilizing an Open Field, Elevated Plus-Maze and Hole Board apparatus. Calcitonin treatment in rats seems to modify open field and elevated plus maze behaviour, suggesting emotionality and anxiety state alterations of the animals. These conditions can be provoked due to the direct calcitonin action on its receptors, even though we do not exclude an action mediated by tissue calcium level alterations.

Effects of deltamethrin pyrethroid on the respiratory metabolism of the neotropical spirostreptid millipedes Gymnostreptus olivaceus and Plusioporus setiger

The effects of deltamethrin on the respiratory metabolism of Gymnostreptus olivaceus and Plusioporus setiger were investigated. Acetone solutions corresponding to half the LD50 values, i.e., 20 μg.g-1g for G. olivaceus and 4.40 μg.g-1 for P. setiger, were used. Metabolism was determined with a Warburg respirometer at 25°C. Respirometric measurements were performed 1, 3 and 6 hours after administration of the pyrethroid to the same groups of millipedes. After 24 hours, daily respirometric measurements lasting 1 hour each were made on different millipede groups for a period of 10 days. Significant differences were detected only between the groups treated with the pyrethroid and the two control groups. In G. olivaceus, respiratory rates increased by about 1.65-fold compared to normal immediately after administration of the pyrethroid, followed by a gradual decrease up to 72 hours and a return to normal levels thereafter. In P. setiger the increase was about 1.1-fold compared to normal, with a decrease up to 96 hours and a return to normal thereafter. Although increased oxygen consumption was observed, a detoxification process occurred in both species, so that the possible metabolism of the pyrethroid may justify the low toxicity of deltamethrin for G. olivaceus and P. setiger.

Avaliação da fertilidade e de possíveis defeitos estruturais externos sobre a prole de ratos machos expostos cronicamente ao arsênio

Arsenic is an environmental pollutant that influences the male reproductive function, affecting the spermatogenesis process in the testis and causing alterations in the sperm. The objective of this work was evaluate the reproductive efficiency in adult male rats exposed to arsenic and the possible male-mediated structural malformations. The animal were treated with sodium arsenato (3,6 mg/Kg, i.p.), twice a weak, for 15, 30, 45, 60 or 75 days whereas control received only distilled water. Results have showed a reduced pregnancy rate associated to a decrease in the fertility potencial and to a increase in the preimplantation loss. There was a decrease in the fetal weights, as showed by its average. Malformations rate, postimplantation loss and resorptions were unaffect by treatment. These results suggest that chronic exposure to arsenic provokes reduction on fertility of male rats. Further studies are required to clarify the arsenic effects on male reproductive system and male-mediated effects on progeny.

Importância da linha de base pré-exposição das colinesterases (ChEs) no controle ocupacional a praguicidas organofosforados e carbamatos

The most immediate toxic effects of a poisoning for organophosphate or carbamate are promoted by inhibition of cholinesterases (ChEs). However, a serious limitation to the diagnosis of mild organophosphate or carbamate poisoning and to preventive screening of organophosphate-exposed workers has been the large interindividual variability in ChEs activity. This makes it necessary to obtain a pre-exposure baseline measurement of enzyme activity as a basis for evaluating subsequent declines. Thus, the objective of this work is demonstrate the value of the pre-exposure baseline in the interpretation of the results of the ChEs activity of the carbamate or organophosphate-exposed workers. Using Nabb & Whitfield (1967) method to analyze blood of 48 workers the results have shown a erythrocyte cholinesterase range of 10.1 to 19.7 μmol/min/mL and plasm cholinesterase range of 2.2 to 6.9 μmol/min/mL. Despite the large interindividual variation presented, when one used the pre-exposure baseline it was possible to correlate symptoms of light poisoning of the exposure workers to carbamate with fall in the Er-ChE activity lesser then 30% of the pre-exposure baseline activity.

Occupational exposure to paint solvents and particulate material in car repair shops

Aims: We evaluated solvents and total particulates exposures in auto body repair shops together with a search of painter's related complaints. Methods: 26 painters exposures were evaluated by pumped personal sampling; solvents were retained in charcoal sorbent tubes and the particulates in PVC filters. Painter's personal habits and their work characteristics were obtained through a questionnaire, applied in a private interview. For the symptoms the Q16 questionnaire was used, added of questions about complaints during the painting. Results: High exposures were detected during spray painting. For solvents, the TLV-STEL adjusted for the mixtures was surpassed in six evaluations. However, as repaint is a short-term operation, it makes the average concentrations weighed for the work shift lower than the TLV-TWA adjusted for the mixtures. Total particulate concentrations had surpassed the TLV-TWA in four of the evaluations. Symptoms frequency in the Q16 questionnaire was higher for painters than for the controls (Mann-Whitney test U=193; p=0.008), and they showed positive correlations with the age (Spearman r=0.354, t=1.85, p=0.076), the number of years in the profession (Spearman r=0.433, t=2.35, p=0.027) and the alcoholic beverage consumption (Spearman r=0.457, t=2.516, p=0.019). Conclusions: The painting work done at car repair shops can result in high solvent and particulate exposures, although they are short-term operations. Their acute and chronic effects for the painters do not have been clearly evidenced in the present study, continuing deserving multidisciplinary attention.

Toxic and genotoxic effects of trivalent and hexavalent chromium - A review

During the last years, the emission of heavy metals to the environment has increased, causing a severe negative impact to the ecosystems and seriously compromising human health due to their mutagenic potential. Tri- (III) and hexavalent (VI) chromium (Cr) constitute the oxidative states of the metal chromium that are active in living organisms. These two oxidation states of the chromium differ with regards to their cellular effects, mainly due to the different abilities they possess in relation to easy of transport through biological membranes. Cr VI is transported into the cell through transference channels of endogenous anions that are isostructural and isoelectronical to Cr VI, such as SO 4 -2 and HPO 4 -2. On the other hand, Cr III is unable to diffuse through the cell membrane. Its existence inside the cells is generally due to the reduction of Cr VI, the endocytosis, or the absortion by the cells via phagocytosis. Cr III acts directly on the DNA molecule, while Cr VI reacts little with this molecule. In the ecosystem, however, Cr VI is more dangerous since this is the form that presents greater reactivity with biological membranes, crossing them and being easily incorporated into the cell. In the cell it is biotransformed to Cr III, a potentially mutagenic molecule. In vivo and in vitro studies have shown that organisms exposed to Cr VI present greater induction to a variety of damages to the DNA molecule. Among the damages induced by Cr, changes in the structure of the DNA molecule have been reported, with breaks of the major chain and base oxidation. In the organisms, these alterations generate chromosomal aberrations, micronucleus formation, sister chromatid exchanges, and errors in DNA synthesis.