The impact of chronic exposure to air pollution over oxidative stress parameters and brain histology.

Air pollution (AP) triggers neuroinflammation and lipoperoxidation involved in physiopathology of several neurodegenerative diseases. Our study aims to investigate the effect of chronic exposure to ambient AP in oxidative stress (OS) parameters and number of neurons and microglial cells of the cortex and striatum. Seventy-two male Wistar rats were distributed in four groups of exposure: control group (FA), exposed throughout life to filtered air; group PA-FA, pre-natal exposed to polluted air until weaning and then to filtered air; group FA-PA, pre-natal exposed to filtered air until weaning and then to polluted air; and group PA, exposed throughout life to polluted air. After 150 days of exposure, the rats were euthanized for biochemical and histological determinations. The malondialdehyde concentration in the cortex and striatum was significantly higher in the PA group. The activity of superoxide dismutase was significantly decreased in the cortex of all groups exposed to AP while activity of catalase was not modified in the cortex or striatum. The total glutathione concentration was lower in the cortex and higher in the striatum of the FA-PA group. The number of neurons or microglia in the striatum did not differ between FA and PA. On the other hand, neurons and microglia cell numbers were significantly higher in the cortex of the FA-PA group. Our findings suggest that the striatum and cortex have dissimilar thresholds to react to AP exposure and different adaptable responses to chronically AP-induced OS. At least for the cortex, changing to a non-polluted ambient early in life was able to avoid and/or reverse the OS, although some alterations in enzymatic antioxidant system may be permanent. As a result, it is important to clarify the effects of AP in the cortical organization and function because of limited capacity of brain tissue to deal with threatening environments.

Pre and post-natal exposure to ambient level of air pollution impairs memory of rats: the role of oxidative stress.

The aims of this study were to evaluate whether air pollution during pre-natal and post-natal phases change habituation and short-term discriminative memories and if oxidants are involved in this process. As secondary objectives, it was to evaluate if the change of filtered to nonfiltered environment could protect the cortex of rats against oxidative stress as well as to modify the behavior of these animals. Wistar, male rats were divided into four groups (n = 12/group): pre and post-natal exposure until adulthood to filtered air (FA); pre-natal period to nonfiltered air (NFA-FA); until (21st post-natal day) and post-natal to filtered air until adulthood (PND21); pre-natal to filtered air until PND21 and post-natal to nonfiltered air until adulthood (FA-NFA); pre and post-natal to nonfiltered air (NFA). After 150 days of air pollution exposure, animals were tested in the spontaneous object recognition test to evaluate short-term discriminative and habituation memories. Rats were euthanized; blood was collected for metal determination; cortex dissected for oxidative stress evaluation. There was a significant increase in malondialdehyde (MDA) levels in the NFA group when compared to other groups (FA: 1.730 +/- 0.217; NFA-FA: 1.101 +/- 0.217; FA-NFA: 1.014 +/- 0.300; NFA: 5.978 +/- 1.920 nmol MDA/mg total proteins; p = 0.007). NFA group presented a significant decrease in short-term discriminative (FA: 0.603 +/- 0.106; NFA-FA: 0.669 +/- 0.0666; FA-NFA: 0.374 +/- 0.178; NFA: -0.00631 +/- 0.106 sec; p = 0.006) and an improvement in habituation memories when compared to other groups. Therefore, exposure to air pollution during both those periods impairs short-term discriminative memory and cortical oxidative stress may mediate this process.

Carbamazepine enhances discriminative memory in a rat model of epilepsy.

PURPOSE: Seizures and antiepileptic drugs (AEDs) are the main causes for cognitive impairment in persons with epilepsy. It is still a matter of debate whether carbamazepine (CBZ) improves cognition because of its own psychotropic effects or because it is more effective to treat temporal epilepsy. Our objective was to analyze the performance of CBZ-treated or nontreated pilocarpine epileptic rats in an object-recognition test. METHODS: Twelve chronic pilocarpine-induced epileptic rats were treated with CBZ, 40 mg/kg, or saline, t.i.d. for 8 days. Twenty-one nonepileptic controls were treated with CBZ or saline. On day 8 of treatment, all rats were tested with an object-recognition paradigm. RESULTS: No locomotor impairment was detected in chronic epilepsy or CBZ treatment, as exploration during training was not affected. Exploratory behaviors during the choice session were not decreased in rats treated with CBZ; therefore CBZ does not compromise procedural memory. Epileptic rats showed a nonsignificant change in the discrimination performance, and prolonged treatment with CBZ in epileptic rats induced a significant increase in object discrimination during the choice session. CONCLUSIONS: Even though pilocarpine-induced epileptic animals do not show compromised performance in the spontaneous object-recognition test, prolonged CBZ treatment has a positive effect on a simple object-discrimination task. These results may be associated with the psychotropic effects of CBZ.

Aspectos clínicos e farmacológicos do uso dos solventes / Clinical and pharmacological aspects about the use of solvents

O uso abusivo de solventes é universal. No Brasil é um problema de saúde pública, tanto entre estudantes, quanto em jovens e adolescentes em situaçäo de rua. O número de usuários tem permanecido elevado ao longo dos últimos anos, mesmo após mudanças na legislaçäo para coibir a venda para crianças e adolescentes. Isto sugere que apenas as medidas restritivas näo apresentaram efetividade, sem que haja, também, programas de prevençäo primários e secundários mais abrangentes. Nesse estudo fez-se uma revisäo bibliográfica sobre os solventes ou inalantes, enfocando-se aspectos básicos para melhorar o diagnóstico e tratamento do uso abusivo de tais substâncias. Säo descritas as substâncias mais utilizadas e o seu mecanismo de açäo, no sentido de justificar as manifestaçöes clínicas e alteraçöes patológicas geradas pelo seu uso a curto ou a médio prazo. Também säo abordados os principais aspectos em relaçäo ao abuso, incluindo os métodos de inalaçäo e a epidemiologia do uso no Brasil. Finalmente, propöe-se um protocolo de exame clínico sumário que visa facilitar o diagnóstico clínico de intoxicaçäo aguda e crônica de solventes entre crianças

Aspectos clinicos e farmacologicos do uso de solventes

O uso abusivo de solventes e universal. No Brasil e um problema de saude publica, tanto entre estudantes, quanto em jovens e adolescentes em situacao de rua. O numero de usuarios tem permanecido elevado ao longo dos ultimos anos, mesmo apos mudancas na legislacao para coibir a venda para criancas e adolescentes. Isto sugere que apenas as medidas restritivas nao apresentam efetividade, sem que haja, tambem, programas de prevencao primarios e secundarios mais abrangentes. Nesse estudo fez-se uma revisao bibliografica sobre os solventes e inalantes, enfocando-se aspectos basicos para melhorar o diagnostico e tratamento do uso abusivo de tais substancias. Sao descritas as substancias mais utilizadas e seu mecanismo de acao, no sentido de justificar as manifestacoes clinicas e alteracoes patologicas geradas pelo seu uso a curto ou a medio prazo. Tambem sao abordados os principais aspectos em relacao ao abuso, incluindo os metodos de inalacao e a epidemiologia do uso no Brasil. Finalmente propoe-se um protocolo de exame clinico sumario que visa facilitar o diagnostico clinico de intoxicacao aguda e cronica de solventes entre criancas.