Production of Human Antibody Fragments Binding to Melittin and Phospholipase A2 in Africanised Bee Venom: Minimising Venom Toxicity

The hybrid created from the crossbreeding of European and African bees, known as the Africanised bee, has provided numerous advantages for current beekeeping. However, this new species exhibits undesirable behaviours, such as colony defence instinct and a propensity to attack en masse, which can result in serious accidents. To date, there is no effective treatment for cases of Africanised bee envenomation. One promising technique for developing an efficient antivenom is the use of phage display technology, which enables the production of human antibodies, thus avoiding the complications of serum therapy, such as anaphylaxis and serum sickness. The aim of this study was to produce human monoclonal single-chain Fv (scFv) antibody fragments capable of inhibiting the toxic effects of Africanised bee venom. We conducted four rounds of selection of antibodies against the venom and three rounds of selection of antibodies against purified melittin. Three clones were selected and tested by enzyme-linked immunosorbent assay to verify their specificity for melittin and phospholipase A2. Two clones (C5 and C12) were specific for melittin, and one (A7) was specific for phospholipase A2. In a kinetic haemolytic assay, these clones were evaluated individually and in pairs. The A7-C12 combination had the best synergistic effect and was chosen to be used in the assays of myotoxicity inhibition and lethality. The A7-C12 combination inhibited the in vivo myotoxic effect of the venom and increased the survival of treated animals.

Antidepressants prevent hierarchy destabilization induced by lipopolysaccharide administration in mice: a neurobiological approach to depression

In spite of the high prevalence and negative impact of depression, little is known about its pathophysiology. Basic research on depression needs new animal models in order to increase knowledge of the disease and search for new therapies. The work presented here aims to provide a neurobiologically validated model for investigating the relationships among sickness behavior, antidepressants treatment, and social dominance behavior. For this purpose, dominant individuals from dyads of male Swiss mice were treated with the bacterial endotoxin lipopolysaccharide (LPS) to induce social hierarchy destabilization. Two groups were treated with the antidepressants imipramine and fluoxetine prior to LPS administration. In these groups, antidepressant treatment prevented the occurrence of social destabilization. These results indicate that this model could be useful in providing new insights into the understanding of the brain systems involved in depression.

Incapacidade para o trabalho: análise dos benefícios auxílio-doença concedidos no estado de Rondônia

Trata-se de um estudo epidemiológico descritivo com objetivo de estimar a prevalência e a duração dos benefícios auxílio-doença, concedidos pelo Instituto Nacional de Seguro Social, bem como dos fatores associados à incapacidade para o trabalho entre os trabalhadores empregados em Rondônia em 2008. As prevalências foram apresentadas por 10.000 trabalhadores e estratificadas por sexo, idade, diagnóstico, atividade econômica, espécie e duração dos benefícios. Os homens apresentaram maiores prevalência e duração dos benefícios. Os benefícios previdenciários mostraramse 2,5 mais prevalentes do que os acidentários e ambos aumentaram com a idade. Os acidentários foram mais prevalentes na faixa etária de 50-59 anos. Silvicultura, construção civil e locação de mão de obra apresentaram as maiores prevalências. Os principais grupos diagnósticos foram lesões; doenças do sistema osteomuscular e doenças do aparelho digestivo. A duração dos benefícios auxílio-doença foi maior entre homens, com > 40 anos e na espécie previdenciária. A atividade econômica é um importante fator de risco para a incapacidade para o trabalho, e precisa ser mais bem explorada como tal visando melhorar a prevenção de doenças e diminuir o impacto na saúde dos trabalhadores decorrentes das condições ambientais e dos processos de trabalho.