Mechanism of the cytotoxic effect of l-amino acid oxidase isolated from Bothrops alternatus snake venom.

BaltLAAO-I, an L-amino acid oxidase isolated from Bothrops alternatus, is a glycoprotein enzyme with a pI-5.3, 15% sugar and a related molecular mass of 66,000Da in its monomeric form, and 123,000Da in its dimeric form. The objective of this study is to describe the cytotoxicity activity induced by BaltLAAO-I isolated from Bothrops alternatus venom and its possible mechanism of action on tumor cells. Our results clearly depict that BaltLAAO-I has a strong selective cytotoxic activity on tumor cell lines (JURKAT, SK-BR-3 and B16F10). On the other hand, the results show low cytotoxicity on human peripheral blood mononuclear cells. Furthermore, our findings demonstrate that BaltLAAO-I induces the apoptosis of tumor cell lines through a cytotoxic activity exerted by a generation of reactive oxygen intermediates. All in all, the data indicate that LAAOs exert a selective cytotoxic role on tumor cells, demonstrating a great potential for future use in clinical therapy.

Validation of an instrument to assess factors associated with adherence to standard precautions among dentists in primary healthcare.

Accidents with biological material are a reality in dental practice. The use of preventive measures such as the adoption of Standard Precautions (SP) is essential, thus this study aims to validate an instrument to check factors associated with adherence to SP among dentists. The scales of psychosocial and organizational factors that influence adherence to SP were the starting point. These scales have already been nationally validated for doctors and nurses. The instrument consisted of 49 items divided into five dimensions. The process of instrument validation involved the following steps: its adaptation for situations that pose risks to dentists; content and semantic analysis by a committee of judges, and application to dentists. The adapted instrument was applied to 224 dentists who provided primary healthcare in the north region of Paraná State. After the application of scales, the psychometric properties were analyzed using the factor analysis technique and a reliability test. The factor analysis confirmed three domains: Obstacles to following standard precautions; Knowledge of occupational transmission of HIV and Safety climate. The reliability of the domains was considered adequate (Cronbach's alpha between 0.73 and 0.88.). The instrument demonstrated adequate psychometric properties to assess factors that influence adherence to SP among dentists.

Validation of an instrument to assess factors associated with adherence to standard precautions among dentists in primary healthcare

Accidents with biological material are a reality in dental practice.The use of preventive measures such as the adoption ofStandard Precautions (SP) is essential, thus this study aims tovalidate an instrument to check factors associated with adherenceto SP among dentists. The scales of psychosocial andorganizational factors that influence adherence to SP were thestarting point. These scales have already been nationally validatedfor doctors and nurses. The instrument consisted of 49items divided into five dimensions. The process of instrumentvalidation involved the following steps: its adaptation for situationsthat pose risks to dentists; content and semantic analysisby a committee of judges, and application to dentists. Theadapted instrument was applied to 224 dentists who providedprimary healthcare in the north region of Paraná State. Afterthe application of scales, the psychometric properties wereanalyzed using the factor analysis technique and a reliabilitytest. The factor analysis confirmed three domains: Obstaclesto following standard precautions; Knowledge of occupationaltransmission of HIV and Safety climate. The reliability of thedomains was considered adequate (Cronbach’s alpha between0.73 and 0.88.). The instrument demonstrated adequate psychometricproperties to assess factors that influence adherenceto SP among dentists...

Os acidentes com presença de material biológico são umarealidade na prática odontológica. A utilização de medidaspreventivas como a adoção das Precauções Padrão (PP) éessencial, desta maneira este estudo tem como objetivo validarum instrumento para verificação de fatores associadosà adesão às PP, entre dentistas. Partiram-se das Escalas deFatores Psicossociais e Organizacionais que Influenciam aAdesão às Precauções-Padrão, já validadas nacionalmentepara enfermeiros e médicos. O instrumento compôs-se de49 itens distribuídos em 5 dimensões. O processo de validaçãodo instrumento seguiu as seguintes etapas: adaptaçãodo instrumento para as situações que envolvem riscos aosdentistas por meio da análise semântica e análise de conteúdo,as quais foram realizadas por um comitê de juízes. Oinstrumento adaptado foi para 224 dentistas que atuavamna Rede Básica de Saúde na região Norte do Estado doParaná. Após aplicação das escalas foram analisadas aspropriedades psicométricas através das técnicas de análisefatorial e teste de confiabilidade. A análise fatorial confirmoutrês domínios: Obstáculo para seguir às PrecauçõesPadrão; Conhecimento da transmissão ocupacional do HIVe Clima de segurança. A confiabilidade dos domínios foiconsiderada adequada (alfa de Cronbach entre 0,73 e 0,88).O instrumento demonstrou propriedades psicométricas adequadaspara avaliar fatores de influência na adesão as PP,entre dentistas...

Validation of an instrument to assess factors associated with adherence to standard precautions among dentists in primary healthcare. / Validation of an instrument to assess factors associated with adherence to standard precautions among dentists in primary healthcare.

Accidents with biological material are a reality in dental practice. The use of preventive measures such as the adoption of Standard Precautions (SP) is essential, thus this study aims to validate an instrument to check factors associated with adherence to SP among dentists. The scales of psychosocial and organizational factors that influence adherence to SP were the starting point. These scales have already been nationally validated for doctors and nurses. The instrument consisted of 49 items divided into five dimensions. The process of instrument validation involved the following steps: its adaptation for situations that pose risks to dentists; content and semantic analysis by a committee of judges, and application to dentists. The adapted instrument was applied to 224 dentists who provided primary healthcare in the north region of Paraná State. After the application of scales, the psychometric properties were analyzed using the factor analysis technique and a reliability test. The factor analysis confirmed three domains: Obstacles to following standard precautions; Knowledge of occupational transmission of HIV and Safety climate. The reliability of the domains was considered adequate (Cronbachs alpha between 0.73 and 0.88.). The instrument demonstrated adequate psychometric properties to assess factors that influence adherence to SP among dentists.

Biological activities from extracts of endophytic fungi isolated from Viguiera arenaria and Tithonia diversifolia.

A total of 39 endophytic fungi have been isolated from Viguiera arenaria and Tithonia diversifolia, both collected in São Paulo State, Brazil. The isolates were identified based on their ribosomal DNA sequences. The ethyl acetate (EtOAc) extracts of all endophytic fungi were evaluated for their antimicrobial, antiparasitic and antitumoral activity. Antimicrobial screening was conducted using an agar diffusion assay against three pathogenic microorganisms: Staphylococcus aureus, Escherichia coli and Candida albicans. Antiparasitic activity was determined by enzymatic inhibition of gGAPDH of Trypanosoma cruzi and adenine phosphorybosiltransferase (APRT) of Leishmania tarentolae. Antitumoral activity was tested against human T leukemia cells by the Mosmann colorimetric method. All extracts showed activity in at least one assay: 79.5% of the extracts were cytotoxic against leukemia cells, 5.1% of the extracts were active against S. aureus, 25.6% against E. coli and 64.1% against Candida albicans. Only one extract showed promising results in the inhibition of parasitic enzymes gGAPDH (95.0%) and three were found to inhibit APRT activity. The cytotoxic extract produced by the strain VA1 (Glomerella cingulata) was fractionated and yielded nectriapyrone and tyrosol. Nectriapyrone showed relevant cytotoxic activity against both human T leukemia and melanoma tumor cell lines.

Cytotoxic L-amino acid oxidase from Bothrops moojeni: biochemical and functional characterization.

An L-amino acid oxidase isolated from Bothrops moojeni snake venom (BmooLAAO-I) was purified to a high degree using sequential CM-Sepharose ion-exchange and phenyl-Sepharose chromatography. When analyzed by mass spectrometry, the purified BmooLAAO-I presented a molecular weight of 64,889 and 130,779 under denaturing and nondenaturing conditions, respectively. BmooLAAO-I is a homodimeric acidic glycoprotein with a pI approximately 4.7, and the N-terminal sequence shows close structural similarity to other snake venom LAAOs. This enzyme was inactivated by freezing or low pH, and secondary structural analysis by circular dichroism revealed 48% alpha-helix, 20% beta-sheet, 12% beta-turn, and 20% random coil structures. BmooLAAO-I exhibited bactericidal, antitumoral, trypanocidal, edematogenic, and platelet-aggregating activities. All of these effects were inhibited by catalase, suggesting that these biological effects are mediated by the production of H(2)O(2). BmooLAAO-I induced typical apoptotic DNA fragmentation in HL-60 cells, which was also inhibited by catalase. These results point to the potential use of BmooLAAO-I as a therapeutic agent for treatment of diseases in which induction of H(2)O(2) production can be beneficial.