Clinical applications and methemoglobinemia induced by dapsone

Dapsona é uma sulfona sintética que é utilizada como um antibiótico em seres humanos e animais para prevenir e tratar doenças, incluindo hanseníase, tuberculose, malária, e pneumonia por Pneumocystis carinii e encefalites por Toxoplasma gondii em pacientes com síndrome da imunodeficiência adquirida (AIDS), bem como em doenças anti-inflamatórias como dermatite herpetiforme. No entanto, este fármaco também está associado com vários efeitos adversos, incluindo a hemólise relacionada com a dose, metemoglobinemia, psicose, neuropatia periférica, agranulocitose, anemia aplástica, síndrome de hipersensibilidade, síndrome de sulfona, e outros. Destes efeitos, a metemoglobinemia é o mais comum efeito adverso da dapsona, que leva a anemia funcional e hipóxia celular com sintomas de cianose, dores de cabeça, fadiga, taquicardia, fraqueza e tonturas. Assim, esta revisão sumariza informações relevantes sobre a estrutura, mecanismo de ação, indicação clínica, e reações adversas de dapsona.

Formadores de filmes híbridos ureasil-poliéter para proteção da pele e liberação controlada de fármacos

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

Avaliação dos efeitos citotóxicos, genotóxicos e mutagênicos do fipronil, após fotodegradação, utilizando Allium cepa como organismo teste

Compounds released into the environment can induce genetic alterations in living organisms. A group of chemicals that shows proven toxicity is the pesticides, and the insecticides are the most harmful. The insecticides of the family phenylpyrazole have wide application both in agriculture and in homes. Fipronil, an insecticide of this chemical group, is widely used in various cultures and in homes, mainly for fighting fleas and ticks on dogs and cats. The use of fipronil may represent a risk to man and the environmental health, since this pesticide can potentially induce cell death, regardless of cell type. Fipronil, when in contact with the environment, can undergo various degradation processes, including photodegradation. The toxic effect of one of its metabolites derived from photodegradation, sulfone-fipronil, is approximately 20 fold as great as fipronil itself. The A. cepa test system was used to evaluate cytotoxic, genotoxicity and mutagenic effects of fipronil before and after phptodegradation. Seeds of Allium cepa were subjected to solutions of fipronil, pre-exposed or not exposed to degradation by sunlight. The germination tests were conducted both under the effect of light and in the dark. We evaluated the cumulative potential of this insecticide using 48 and 72-hours recovery tests. The results showed that when fipronil was previously exposed to the sun, it presented a greater genotoxic and mutagenic potential, showing that the metabolites formed by photodegradation can show more harmfull effects

Fipronil e produtos de degradação: adaptação de método analítico e caracterização de amostras de água, solo e sedimento da Bacia Hidrográfica do Turvo/Grande

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Efeitos bioquímicos de contaminação em girinos de Eupemphix nattereri expostos a solos contendo o agrotóxico fipronil e seus produtos de degradação

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Avaliação da biodessulfurização de 4-metildibenzotiofeno por Rhodococus rhodochrous (NRRL B-2149)

Crude oil has between 0.04 up to 5% of sulphur, the higher the oil the higher the sulphur levels. Sulphur usually gives problems such as corrosion in refinery, and once burnt produces SO2 that goes to atmosphere. This work aim to investigate the capacity of Rhodococcus rhodochrous (NRRL B-2149) to metabolize the model compound 4-methyldibenzotiophene (4-MDBT), to remove the sulphur and transform it in 2-hydroxybiphenyl (2-HBF) and sulphite using the 4S pathway. Kynetic runs were carried out in shaker at 120 rpm and 32°C. Samples were taken every 12h to assay substrate consume as well as cells production using HPLC. Results showed that R. rhodochrous NRRL B-2149 can use the 4S pathway in order to remove sulphur without change the carbon chain of the molecule as well as that cells and 4-MDBT affects the product formation. The production of 2-hydroxybiphenyl has interest for industry once it is a potent biocide. However, evaluation is necessary in order to obtain better results compatible with industry needs