Caracterização funcional da BaltMTx, uma miotoxina isolada da peçonha de Bothrops alternatus

CHAPTER II: Snake venoms are a complex mixture of organic and inorganic compounds, proteins and peptides such as aminotransferases, acetylcholinesterase, hyaluronidases, L-amino acid oxidase, phospholipase A2, metalloproteases, serine proteases, lectins, disintegrins, and others. Phospholipase A2 directly or indirectly influence the pathophysiological effect on envenomation, as well as their participation in the digestion of the prey. They have several other activities such as hemolytic indirect action, cardiotoxicity, aggregating of platelets, anticoagulant, edema, myotoxic and inflammatory activities. In this work, we describe the functional characterization of BaltMTx, a PLA2 from Bothrops alternatus that inhibits platelet aggregation and present bactericidal effect. The purification of BaltMTx was carried out through three chromatographic steps (ion-exchange on a DEAE-Sephacel column, followed by hydrophobic chromatography on Phenyl–Sepharose and affinity chromatography on HiTrap™ Heparin HP). The protein was purified to homogeneity as judged by its migration profile in SDS–PAGE stained with coomassie blue, and showed a molecular mass of about 15 kDa under reducing conditions and approximately 25 kDa in non-reducing conditions. BaltMTx showed a rather specific inhibitory effect on platelet aggregation induced by epinephrine in human platelet-rich plasma in a dose-dependent manner, whereas it had little or no effect on platelet aggregation induced by collagen or adenosine diphosphate. BaltMTx also showed antibacterial activity against Staphylococcus aureus and Escherichia coli. High concentrations of BatlMTx stimulated the proliferation of Leishmania (Leishmania) infantum and Leishmania (Viania) braziliensis. BaltMTx induced production of inflammatory mediators such as IL-10, IL-12, TNF-α and NO. BaltMTx could be of medical interest as a new tool for the development of novel therapeutic agents for the prevention and treatment of thrombotic disorders as well as bactericidal agent.

Das saudades que se tem: a representação paterna na escrita autobiográfica de Bartolomeu Campos de Queirós

In our work, we analyze some works of Bartolomeu Campos de Queirós that compose the “autobiographical cycle”, especially those ones that bring the image of father’s absence/presence, the relationship between life and writing, as well as the father’s figurations and his intermediates and substitutes. We especially investigated the aspect of repetition about how the family relations are articulated, highlighting those ones that happen between father and son and that appear in these texts. This problematic interested us as a research object, a priori, because the works of Bartholomeu Campos de Queirós are an exponent of literature for children field, as far as they show that the childhood is not always “colorful”, happy and perfect as several productions supposedly made “for children” seek to have us believe. In addition, the selected texts that have an autobiographical characteristic and put the issue of child suffering because of the father’s absence are configured as a very rich corpus for studies related to the relation between life/work and investigations in the dialogue between Literature and Psychoanalysis. These aspects will permit us to understand why the pain of missing father be repetitive and insistent in these books. Thus, we problematize, by the selected works for this study, the concept of literature for children and young people and the notion of literary reading. We also analyzed in the “statements” given by the author the relationship between life and writing and we investigated, based on psychoanalytic studies, the literary writing as a possibility of both unconscious development of memory marked by the father’s absence – remedy – as of a perpetuation of this same conflict – poison. Furthermore, we analyzed how the relationship between son and father are processed considering the mother’s absence, since the works that have this person’s presence, she seems to mediate such relationships in a certain way.