The emergence of new infectious diseases, the resurgence of several infections that appeared to have been controlled and the increase in bacterial resistance have created the necessity for studies directed towards the development of new antimicrobials. Considering the failure to acquire new molecules with antimicrobial properties from microorganisms, the optimization for screening methods used for the identification of antimicrobials from other natural sources is of great importance. The objective of this study was to evaluate technical variants used in screening methods to determine antibacterial activity of natural products. Thus, a varied range of natural products of plant, fungi and lichen origin were tested against two bacterial species, Staphylococcus aureus ATCC 25923 and Escherichia coli ATCC 25922, by two variants of the agar diffusion method (well and disc), two variants of the bioautographic method (direct and indirect) and by microdilution assay. We concluded that the well-variant of the diffusion method was more sensitive than the disc-variant, whilst the direct-variant of the bioautographic method exhibited a greater sensitivity if compared to indirectvariant. Bioautographic and diffusion techniques were found to have similar sensitivity; however the latter technique provided more suitable conditions for the microbial growth. In this study, we also discussed the best conditions for the determination of minimal inhibitory concentration.

OBJETIVO: Conhecer a automedicação em crianças moradoras de uma cidade da região Sul do Brasil. MÉTODOS: Estudo transversal com amostra selecionada por sorteio, inicialmente identificando as equipes de Estratégia Saúde da Família e, posteriormente, as residências que seriam visitadas. Foi adotado, para a entrevista com o responsável pelas crianças, um questionário para avaliar o perfil da criança, da família e da prática da automedicação. Para apresentação dos dados, adotou-se a estatística descritiva e o teste do qui-quadrado (p<0,05). RESULTADOS: Entrevistaram-se os responsáveis pelas crianças em 83 domicílios. Foram coletadas informações de 121 crianças (seis meses a 14 anos). Dos entrevistados, 75% afirmaram já ter praticado a automedicação, sendo as mães responsáveis por 95% desses casos. Quanto às situações que motivaram a automedicação, praticidade (88%), febre (58%) e dor (12%) foram as mais relatadas. O paracetamol (45%) e a dipirona (15%) foram os fármacos mais utilizados. A análise estatística evidenciou associação entre a reutilização de antigas prescrições e a idade da criança inferior a sete anos, bem como entre a utilização de medicamentos sem prescrição de profissional habilitado e morar em domicílios com mais de quatro pessoas. CONCLUSÕES: A automedicação é uma prática frequente na população investigada, sendo geralmente mais comum em crianças de até sete anos e realizada principalmente pelas mães; esse fato sugere a necessidade de promover educação em saúde que vise à promoção do uso racional de medicamentos.

No abstract

Biomass growth, micronucleus induction, and antioxidative stress enzymes (superoxide dismutase, peroxidase, glutathione reductase, and catalase) were investigated simultaneously in the Vicia faba plant exposed to cadmium in solution. The biomass lowest-observed-effect concentration (LOEC) value was 2,000 microM Cd2+. In the shoots, enzymic activities increased without concentration-response relationships. In the roots, after an initial increase, activities of all enzymes showed negative concentration-response relationships. A significant increase in micronucleus induction was observed at 20 microM Cd2+. Regarding sensitivity, our results showed that biomass endpoint was less sensitive than micronucleus induction, which was less sensitive than antioxidative enzyme activities. The increase of antioxidant stress enzyme activities in response to cadmium exposure may be taken as evidence for an enhanced detoxification capacity of V. faba plants toward reactive oxygen species (and derivatives) that might be generated in the stressed plants. Concomitant micronucleus induction may be also interpreted as a consequence of oxidative stress, upholding the view that cadmium-induced DNA damage is, to some extent, via generation of reactive (intermediate) oxygen species.

Biomass growth, micronucleus induction, and antioxidative stress enzymes (superoxide dismutase, peroxidase, glutathione reductase, and catalase) were investigated simultaneously in the Vicia faba plant exposed to cadmium in solution. The biomass lowest-observed-effect concentration (LOEC) value was 2,000 microM Cd2+. In the shoots, enzymic activities increased without concentration-response relationships. In the roots, after an initial increase, activities of all enzymes showed negative concentration-response relationships. A significant increase in micronucleus induction was observed at 20 microM Cd2+. Regarding sensitivity, our results showed that biomass endpoint was less sensitive than micronucleus induction, which was less sensitive than antioxidative enzyme activities. The increase of antioxidant stress enzyme activities in response to cadmium exposure may be taken as evidence for an enhanced detoxification capacity of V. faba plants toward reactive oxygen species (and derivatives) that might be generated in the stressed plants. Concomitant micronucleus induction may be also interpreted as a consequence of oxidative stress, upholding the view that cadmium-induced DNA damage is, to some extent, via generation of reactive (intermediate) oxygen species.