Jovens cientistas: enfrentamento às arboviroses e participação juvenil no território / Young scientists: facing arboviruses and youth participation in the territory / Jóvenes investigadores: enfrentamiento a las arbovirosis y participación juvenil en el território

O estudo analisa uma formação em Iniciação Científica sobre arboviroses, a partir da percepção de jovens estudantes, em Ceilândia ­ Distrito Federal. Objetivo: compreender em que medida a Iniciação Científica mobiliza esses jovens a participarem de ações de vigilância e promoção da saúde no território, e entender sua motivação para participar do projeto. Metodologia: abrangeu-se a análise das redações escritas para a seleção ao Curso de Formação para Iniciação Científica na Educação Básica e as Arboviroses; a administração desse curso e; posteriormente, um grupo focal com estudantes para análise do processo educativo da Iniciação Científica que vivenciaram. Resultados: a análise de conteúdo evidenciou a percepção dos alunos sobre a Iniciação Científica, centrada em seis categorias analíticas: motivação dos alunos para Iniciação Científica; processo de formação do saber; formação de jovens cientistas; saúde e meio ambiente; participação e empoderamento juvenil e percepções acerca do Sistema Público de Saúde. Conclusão: o enfrentamento às arboviroses exige políticas e intervenções de amplo espectro, e a Iniciação Científica fortaleceu esses jovens estudantes enquanto sujeitos de direitos, ampliou sua percepção sobre ciência, saúde, relação com o ambiente, com o Sistema Único de Saúde e estimulou o interesse em ações preventivas no combate às arboviroses nesses territórios.

This study analyzes a Scientific Initiation (SI) program on arboviroses, from the perception of young high school students in Ceilândia ­ Distrito Federal. Objective: It aims to understand to what extent the SI mobilizes these young people to participate in surveillance and health promotion actions in the territory and understand their motivation to participate in this project. Methodology: The methodology included the analysis of the essays written for the selection to the Training Course for Scientific Initiation in Basic Education and the Arboviroses, the administration of this course, and later a focus group with students to analyze the SI educational process they experienced. Results: The result of the Content Analysis showed that the students' perception about the SI could be grouped into six categories: students' motivation for the scientific initiation; the learning process; the training of young scientists; health and environment; youth participation and empowerment, and perceptions of the Public health system in Brazil (SUS). Conclusion: Confronting arboviroses requires broad-spectrum policies and interventions, and the SI strengthened these young students as subjects of rights, broadened their perception of science, health, relationship with the environment, with the Sistema Único de Saúde and stimulated interest in preventive actions to combat arboviroses in these territories. Keywords: Health education; Arbovirus infections; Adolescents; Public health.

Analiza una formación en Iniciación Científica (IC) sobre arbovirus, desde la percepción de jóvenes estudiantes de secundaria en Ceilândia, Distrito Federal. Objetivo: el objetivo es comprender en qué medida la IC moviliza a estos jóvenes a participar en acciones de vigilancia y promoción de la salud en el territorio, así como entender su motivación para participar en proyectos de IC. Metodología: la metodología incluyó el análisis de las redacciones escritas para la selección al Curso de Formación para Iniciación Científica en Educación Básica y Arbovirus, la administración de este curso y, posteriormente, un grupo focal con los estudiantes para analizar el proceso educativo de IC que vivieron. Resultados: los resultados del Análisis de Contenido mostraron la percepción de los estudiantes sobre la IC enfocada en seis categorías analíticas: motivación de los estudiantes por la iniciación científica; proceso de formación de conocimientos; formación de jóvenes científicos; salud y medio ambiente; participación y empoderamiento de los jóvenes y percepciones sobre el Sistema Público de Salud (SUS). Conclusiones: Enfrentar los arbovirus requiere políticas e intervenciones de amplio espectro, y la IC fortaleció a estos jóvenes estudiantes como sujetos de derechos, ampliando su percepción sobre ciencia, salud, relación con el entorno, con el Sistema Único de Salud y estimuló el interés en acciones preventivas en la lucha contra los arbovirus en estos territorios.

Purification and characterization of peptides Ap2, Ap3 and Ap5 (ω-toxins) from the venom of the Brazilian tarantula Acanthoscurria paulensis.

Peptides isolated from spider venoms are of pharmacological interest due to their neurotoxic activity, acting on voltage-dependent ion channels present in different types of human body tissues. Three peptide toxins titled as Ap2, Ap3 and Ap5 were purified by RP-HPLC from Acanthoscurria paulensis venom. They were partially sequenced by MALDI In-source Decay method and their sequences were completed and confirmed by transcriptome analysis of the venom gland. The Ap2, Ap3 and Ap5 peptides have, respectively, 42, 41 and 46 amino acid residues, and experimental molecular masses of 4886.3, 4883.7 and 5454.7 Da, with the Ap2 peptide presenting an amidated C-terminus. Amongst the assayed channels - NaV1.1, NaV1.5, NaV1.7, CaV1.2, CaV2.1 and CaV2.2 - Ap2, Ap3 and Ap5 inhibited 20-30 % of CaV2.1 current at 1 µM concentration. Ap3 also inhibited sodium current in NaV1.1, Nav1.5 and Nav1.7 channels by 6.6 ± 1.91 % (p = 0.0276), 4.2 ± 1.09 % (p = 0.0185) and 16.05 ± 2.75 % (p = 0.0282), respectively. Considering that Ap2, Ap3 and Ap5 belong to the 'U'-unknown family of spider toxins, which has few descriptions of biological activity, the present work contributes to the knowledge of these peptides and demonstrates this potential as channel modulators.

Crystallographic structure of a complex between trypsin and a nonapeptide derived from a Bowman-Birk inhibitor found in Vigna unguiculata seeds.

Natural inhibitors of proteases have been classified into different families, among them is the Bowman-Birk Inhibitor (BBI) family. Members of BBI have two structurally reactive loops that simultaneously inhibit trypsin and chymotrypsin. Here, we have investigated the binding of bovine trypsin by a cyclic nonapeptide, named PTRY9 (CTKSIPPQC), derived of the black-eyed pea trypsin/chymotrypsin inhibitor (BTCI) from Vigna unguiculata seeds. This peptide was synthetically produced with the disulfide bond restraining its conformation to mimic the reactive loop that inhibits trypsin. PTRY9 complexed to pancreatic bovine trypsin was crystallized in orthorhombic and trigonal space groups, P212121 and P3221, with maximum resolutions of 1.15 and 1.61 Å, respectively. The structures presented refinement parameters of Rwork = 14.52 % and Rfree = 15.59 %; Rwork = 15.60 % and Rfree = 18.78 %, and different surface area between the peptide and the enzyme of 1024 Å2 and 1070 Å2, respectively. The binding site of the PTRY9 is similar to that found for BTCI as shown by a r.m.s.d. of 0.358 Šbetween the superimposed structures and the electrostatic complementary pattern at the enzyme-peptide interface. Additionally, enzyme inhibition assays show that the affinity of trypsin for PTRY9 is smaller than that for BTCI. In vitro assays revealed that, like BTCI, this synthetic peptide is not cytotoxic for normal mammary epithelial MCF-10A cells, but exerts cytotoxic effects on MDA.MB.231 invasive human breast cancer cells.

Electrophysiological characterization of Tityus obscurus ß toxin 1 (To1) on Na+-channel isoforms.

To1, previously named Tc49b, is a peptide neurotoxin isolated from venom of the scorpion Tityus obscurus that is responsible for lethal human poisoning cases in the Brazilian Amazonian region. Previously, To1 was shown to be lethal to mice and to change Na+ permeation in cerebellum granular neurons from rat brain. In addition, To1 did not affect Shaker B K+ channels. Based on sequence similarities, To1 was described as a ß-toxin. In the present work, To1 was purified from T. obscurus venom and submitted to an electrophysiological characterization in human and invertebrate NaV channels. The analysis of the electrophysiological experiments reveal that To1 enhances the open probability at more negative potentials of human NaV 1.3 and 1.6, of the insect channel BgNaV1 and of arachnid VdNaV1 channel. In addition, To1 reduces the peak of Na+ currents in some of the NaVs tested. These results support the classification of the To1 as a ß-toxin. A structure and functional comparison to other ß-toxins that share sequence similarity to To1 is also presented.

To4, the first Tityus obscurus ß-toxin fully electrophysiologically characterized on human sodium channel isoforms.

Many scorpion toxins that act on sodium channels (NaScTxs) have been characterized till date. These toxins may act modulating the inactivation or the activation of sodium channels and are named α- or ß-types, respectively. Some venom toxins from Tityus obscurus (Buthidae), a scorpion widely distributed in the Brazilian Amazon, have been partially characterized in previous studies; however, little information about their electrophysiological role on sodium ion channels has been published. In the present study, we describe the purification, identification and electrophysiological characterization of a NaScTx, which was first described as Tc54 and further fully sequenced and renamed To4. This toxin shows a marked ß-type effect on different sodium channel subtypes (hNav1.1-hNav1.7) at low concentrations, and has more pronounced activity on hNav1.1, hNav1.2 and hNav1.4. By comparing To4 primary structure with other Tityus ß-toxins which have already been electrophysiologically tested, it is possible to establish some key amino acid residues for the sodium channel activity. Thus, To4 is the first toxin from T. obscurus fully electrophysiologically characterized on different human sodium channel isoforms.

Antiviral activity of animal venom peptides and related compounds.

Viruses exhibit rapid mutational capacity to trick and infect host cells, sometimes assisted through virus-coded peptides that counteract host cellular immune defense. Although a large number of compounds have been identified as inhibiting various viral infections and disease progression, it is urgent to achieve the discovery of more effective agents. Furthermore, proportionally to the great variety of diseases caused by viruses, very few viral vaccines are available, and not all are efficient. Thus, new antiviral substances obtained from natural products have been prospected, including those derived from venomous animals. Venoms are complex mixtures of hundreds of molecules, mostly peptides, that present a large array of biological activities and evolved to putatively target the biochemical machinery of different pathogens or host cellular structures. In addition, non-venomous compounds, such as some body fluids of invertebrate organisms, exhibit antiviral activity. This review provides a panorama of peptides described from animal venoms that present antiviral activity, thereby reinforcing them as important tools for the development of new therapeutic drugs.

Antiviral activity of animal venom peptides and related compounds

Abstract Viruses exhibit rapid mutational capacity to trick and infect host cells, sometimes assisted through virus-coded peptides that counteract host cellular immune defense. Although a large number of compounds have been identified as inhibiting various viral infections and disease progression, it is urgent to achieve the discovery of more effective agents. Furthermore, proportionally to the great variety of diseases caused by viruses, very few viral vaccines are available, and not all are efficient. Thus, new antiviral substances obtained from natural products have been prospected, including those derived from venomous animals. Venoms are complex mixtures of hundreds of molecules, mostly peptides, that present a large array of biological activities and evolved to putatively target the biochemical machinery of different pathogens or host cellular structures. In addition, non-venomous compounds, such as some body fluids of invertebrate organisms, exhibit antiviral activity. This review provides a panorama of peptides described from animal venoms that present antiviral activity, thereby reinforcing them as important tools for the development of new therapeutic drugs.

Antiviral activity of animal venom peptides and related compounds

Viruses exhibit rapid mutational capacity to trick and infect host cells, sometimes assisted through virus-coded peptides that counteract host cellular immune defense. Although a large number of compounds have been identified as inhibiting various viral infections and disease progression, it is urgent to achieve the discovery of more effective agents. Furthermore, proportionally to the great variety of diseases caused by viruses, very few viral vaccines are available, and not all are efficient. Thus, new antiviral substances obtained from natural products have been prospected, including those derived from venomous animals. Venoms are complex mixtures of hundreds of molecules, mostly peptides, that present a large array of biological activities and evolved to putatively target the biochemical machinery of different pathogens or host cellular structures. In addition, non-venomous compounds, such as some body fluids of invertebrate organisms, exhibit antiviral activity. This review provides a panorama of peptides described from animal venoms that present antiviral activity, thereby reinforcing them as important tools for the development of new therapeutic drugs.(AU)

Antiviral activity of animal venom peptides and related compounds

Viruses exhibit rapid mutational capacity to trick and infect host cells, sometimes assisted through virus-coded peptides that counteract host cellular immune defense. Although a large number of compounds have been identified as inhibiting various viral infections and disease progression, it is urgent to achieve the discovery of more effective agents. Furthermore, proportionally to the great variety of diseases caused by viruses, very few viral vaccines are available, and not all are efficient. Thus, new antiviral substances obtained from natural products have been prospected, including those derived from venomous animals. Venoms are complex mixtures of hundreds of molecules, mostly peptides, that present a large array of biological activities and evolved to putatively target the biochemical machinery of different pathogens or host cellular structures. In addition, non-venomous compounds, such as some body fluids of invertebrate organisms, exhibit antiviral activity. This review provides a panorama of peptides described from animal venoms that present antiviral activity, thereby reinforcing them as important tools for the development of new therapeutic drugs.

Pharmacological characterization of Synoeca cyanea venom: an aggressive social wasp widely distributed in the Neotropical region.

The venom of social wasps has been poorly studied so far, despite the high number of accidents in humans and assessment of the use of these wasps as a biological control of pests. The study of the pharmacological effects of the venom is of great importance since the poisoning is dangerous causing serious systemic effects, including death in the case of multiple attacks. In this study, the pharmacological activities of venom from the social wasp Synoeca cyanea were evaluated by the following assays: LD50 in mice, the behavioural effects and the hemorrhagic activity induced by the venom in mice, the oedematogenic activity in rat, the haemolysis in human blood, the stimulating effect on guinea-pig smooth muscle, and the antimicrobial activity. The aim was to determine the toxic effects of venom and to perform a comparative study with earlier work conducted with venom from other wasp species. Results showed that S. cyanea venom produced a potent dose-dependent oedema, as well as antibacterial and haemolytic activities, suggesting the presence of histamine, serotonin, kinins and other molecules related to increased vascular permeability and cytolytic activity in this venom. Despite previous studies with wasp venoms, S. cyanea venom presented a slight hemorrhagic effect. Data obtained in the smooth muscle assay also suggest the presence of BK or analogues in S. cyanea whole venom. The knowledge of symptoms and effects produced by S. cyanea venom is critical for health organizations, in order to improve clinical treatment in accidents caused by wasp stings.