Effects of precocene and azadirachtin in Rhodnius prolixus: some data on development and reproduction

The results presented in this paper clearly indicate that precocene and azadirachtin are effective inhibitors of moulting and reproduction in the hemipteran Rhodnius prolixus. The time of application is important and only applications of these substances early in the intermoulting period cause their effects in nymphs. The inhibition of moulting is fully reversed by ecdysone therapy. Precocene and azadirachtin also affected drastically the oogenesis and egg deposition in this insect. Precocene-induced sterilization is reversed by application of juvenile hormone III. However, this hormone is unable to reverse the effect of azadirachtin on reproduction. Ecdysteroid titers in nymphs and adult females are decreased by these treatments. In vitro analysis suggest that precocene and azadirachtin may act directly on the prothoracic glands and ovaries producing ecdysteroids. Based on these and other findings the possible mode of action of these compounds on the development and reproduction of Rhodnius prolixus is discussed

In vitro Trypanocidal Activity, Genomic Analysis of Isolates, and in vivo Transcription of Type VI Secretion System of Serratia marcescens Belonging to the Microbiota of Rhodnius prolixus Digestive Tract

Serratia marcescens is a bacterium with the ability to colonize several niches, including some eukaryotic hosts. S. marcescens have been recently found in the gut of hematophagous insects that act as parasite vectors, such as Anopheles, Rhodnius, and Triatoma. While some S. marcescens strains have been reported as symbiotic or pathogenic to other insects, the role of S. marcescens populations from the gut microbiota of Rhodnius prolixus, a vector of Chagas’ disease, remains unknown. Bacterial colonies from R. prolixus gut were isolated on BHI agar. After BOX-PCR fingerprinting, the genomic sequences of two isolates RPA1 and RPH1 were compared to others S. marcescens from the NCBI database in other to estimate their evolutionary divergence. The in vitro trypanolytic activity of these two bacterial isolates against Trypanosoma cruzi (DM28c clone and Y strain) was assessed by microscopy. In addition, the gene expression of type VI secretion system (T6SS) was detected in vivo by RT-PCR. Comparative genomics of RPA1 and RPH1 revealed, besides plasmid presence and genomic islands, genes related to motility, attachment, and quorum sensing in both genomes while genes for urea hydrolysis and type II secretion system (T2SS) were found only in the RPA1 genome. The in vitro trypanolytic activity of both S. marcescens strains was stronger in their stationary phases of growth than in their exponential ones, with 65–70 and 85–90% of epimastigotes (Dm28c clone and Y strain, respectively) being lysed after incubation with RPA1 or RPH1 in stationary phase. Although T6SS transcripts were detected in guts up to 40 days after feeding (DAF), R. prolixus morbidity or mortality did not appear to be affected. In this report, we made available two trypanolytic S. marcescens strains from R. prolixus gut to the scientific community together with their genomic sequences. Here, we describe their genomic features with the purpose of bringing new insights into the S. marcescens adaptations for colonization of the specific niche of triatomine guts. This study provides the basis for a better understanding of the role of S. marcescens in the microbiota of R. prolixus gut as a potential antagonist of T. cruzi in this complex system

Desenvolvimento de cartilha educativa sobre alongamento muscular na promoção da saúde do escolar/ Development of educational booklet on muscle stretching in school health promotion

Introdução: A promoção e educação em saúde são essenciais na prevenção de agravos a saúde, as cartilhas educativas surgem como mediadoras deste processo no intuito de informar e conscientizar os indivíduos. Objetivo: Apresentar o processo de desenvolvimento de uma cartilha educativa sobre alongamento muscular na promoção de saúde dos escolares. Métodos: Tratou-se de uma pesquisa descritiva do tipo documental, apresentando material de caráter ilustrativo e informativo. A elaboração da cartilha foi baseada em quatro fases, a saber: 1) Sistematização do Conteúdo, 2) Redação do Conteúdo Teórico, 3) Ilustração do Material, e 4) Avaliação da Cartilha com base no Letramento Funcional em Saúde (LFS). Resultados: Foram escolhidos três livros para o embasamento teórico da cartilha, esta foi estruturada com elementos pré- e pós-textuais (capa, apresentação, índice, bibliografia), e seções compostas por: definição de alongamento, benefícios, indicações, contra-indicações, alongamentos individuais conforme cada segmento corporal e coletivos em dupla com e sem recursos. A ilustração foi feita por uma designer a partir de imagens inspiradas em ações promovidas no Programa Fisioterapia na Escola. A avaliação baseada no LFS obteve classificação da adequação como superior e da legibilidade do material um nível de 6 anos de escolaridade, com adequação para crianças com 11 a 13 anos de idade. Conclusão: A cartilha ‘Esticados’ apresenta-se como um material educativo capaz de ser utilizado por escolares no contexto da abordagem da educação e promoção em saúde, prevenindo alterações posturais, suscitando a consciência da educação em saúde, melhorando a flexibilidade muscula e a qualidade de vida

Phosphatidylinositol 3-kinase/AKT pathway inhibition by doxazosin promotes glioblastoma cells death, upregulation of p53 and triggers low neurotoxicity

Glioblastoma is the most frequent and malignant brain tumor. Treatment includes chemotherapy with temozolomide concomitant with surgical resection and/or irradiation. However, a number of cases are resistant to temozolomide, as well as the human glioblastoma cell line U138-MG. We investigated doxazosin’s (an antihypertensive drug) activity against glioblastoma cells (C6 and U138-MG) and its neurotoxicity on primary astrocytes and organoptypic hippocampal cultures. For this study, the following methods were used: citotoxicity assays, flow cytometry, western-blotting and confocal microscopy. We showed that doxazosin induces cell death on C6 and U138-MG cells. We observed that doxazosin’s effects on the PI3K/Akt pathway were similar as LY294002 (PI3K specific inhibitor). In glioblastoma cells treated with doxasozin, Akt levels were greatly reduced. Upon examination of activities of proteins downstream of Akt we observed upregulation of GSK-3β and p53. This led to cell proliferation inhibition, cell death induction via caspase-3 activation and cell cycle arrest at G0/G1 phase in glioblastoma cells. We used in this study Lapatinib, a tyrosine kinase inhibitor, as a comparison with doxazosin because they present similar chemical structure. We also tested the neurocitotoxicity of doxazosin in primary astrocytes and organotypic cultures and observed that doxazosin induced cell death on a small percentage of non-tumor cells. Aggressiveness of glioblastoma tumors and dismal prognosis require development of new treatment agents. This includes less toxic drugs, more selective towards tumor cells, causing less damage to the patient. Therefore, our results confirm the potential of doxazosin as an attractive therapeutic antiglioma agent

High throughput screening of hydrolytic enzymes from termites using a natural substrate derived from sugarcane bagasse

<p>Abstract</p> <p>Background</p> <p>The description of new hydrolytic enzymes is an important step in the development of techniques which use lignocellulosic materials as a starting point for fuel production. Sugarcane bagasse, which is subjected to pre-treatment, hydrolysis and fermentation for the production of ethanol in several test refineries, is the most promising source of raw material for the production of second generation renewable fuels in Brazil. One problem when screening hydrolytic activities is that the activity against commercial substrates, such as carboxymethylcellulose, does not always correspond to the activity against the natural lignocellulosic material. Besides that, the macroscopic characteristics of the raw material, such as insolubility and heterogeneity, hinder its use for high throughput screenings.</p> <p>Results</p> <p>In this paper, we present the preparation of a colloidal suspension of particles obtained from sugarcane bagasse, with minimal chemical change in the lignocellulosic material, and demonstrate its use for high throughput assays of hydrolases using Brazilian termites as the screened organisms.</p> <p>Conclusions</p> <p>Important differences between the use of the natural substrate and commercial cellulase substrates, such as carboxymethylcellulose or crystalline cellulose, were observed. This suggests that wood feeding termites, in contrast to litter feeding termites, might not be the best source for enzymes that degrade sugarcane biomass.</p

Cultivation-Independent Methods Reveal Differences among Bacterial Gut Microbiota in Triatomine Vectors of Chagas Disease

Chagas disease is one of the most important endemic diseases of South and Central America. Its causative agent is the protozoan Trypanosoma cruzi, which is transmitted to humans by blood-feeding insects known as triatomine bugs. These vectors mainly belong to Rhodnius, Triatoma and Panstrongylus genera of Reduviidae. The bacterial communities in the guts of these vectors may have important effects on the biology of T. cruzi. For this reason, we analyzed the bacterial diversity hosted in the gut of different species of triatomines using cultivation-independent methods. Among Rhodnius sp., we observed similar bacterial communities from specimens obtained from insectaries or sylvatic conditions. Endosymbionts of the Arsenophonus genus were preferentially associated with insects of the Panstrongylus and Triatoma genera, whereas the bacterial genus Serratia and Candidatus Rohrkolberia were typical of Rhodnius and Dipetalogaster, respectively. The diversity of the microbiota tended to be the largest in the Triatoma genus, with species of both Arsenophonus and Serratia being detected in T. infestans

Reflexões sobre a pessoa e a profissão do professor na área da saúde

Este artigo deriva de um conjunto de ideias experimentadas por discentes do Programa de Pós-graduação em Medicina e Ciências da Saúde da Pontifícia Universidade Católica do Rio Grande do Sul (PUCRS), em uma disciplina que procurou conhecer melhor o docente típico e suas atipias. O texto pretende auxiliar no entendimento de quem é o professor na área da saúde. Discute o sujeito e sua obra, para além do já conhecido modelo centrado na profissão da saúde que exerce e que procura ensinar. Antes de docente, o professor é uma pessoa. Como pessoa, precisa sentir-se estimada e estimar ao outro (aluno). Ao prosperar em seu trabalho, o docente tem compromissos para com o desenvolvimento intelectual e moral de seus alunos e o planejamento de ações para que exerça a percepção crítica da realidade. A relação ensino-aprendizagem com o educando deve favorecer a análise de valores necessários ao convívio social. Na área da saúde, é requisitado ao aluno aprender a fazer, sendo pouca importância referida ao aprender a conhecer, ao aprender a ser ou a viver em comunhão com os pares. É essencial ter a percepção de que o professor necessita, inicialmente, acolher a si próprio: entender quem é ele, como é e porque chegou ali. A construção da identidade profissional docente é um processo contínuo estabelecido pelo domínio de sua área de ensino, pelos conhecimentos pedagógicos voltados à aprendizagem dos alunos e experiência docente, além das relações sociais do cotidiano