The roles of mucus-forming mucins, peritrophins and peritrophins with mucin domains in the insect midgut.

Most insects have a gut lined with a peritrophic membrane (PM) consisting of chitin and proteins, mainly peritrophins that have chitin-binding domains. The PM is proposed to originate from mucus-forming mucins (Mf-mucins), which acquired a chitin-binding domain that interlocked with chitin, replacing mucus in function. We evaluated the expression of Mf-mucins and peritrophins by RNA-sequencing (RNA-seq) throughout the midgut of four distantly related insects. Mf-mucins were identified as proteins with high o-glycosylation and a series of uninterrupted Pro/Thr/Ser residues. The results demonstrate that the mucus layer is widespread in insects, and suggest that insect Mf-mucins are derived from those found in other animals by the loss of the cysteine knot and von Willebrand domains. The data also support a role of Mf-mucins in protecting the middle midgut of Musca domestica against acidic buffers. Mf-mucins may also produce a jelly-like material associated with the PM that immobilizes digestive enzymes in Spodoptera frugiperda. Peritrophins with a domain similar to Mf-mucins may be close to the ancestor of peritrophins. Expression data of peritrophins and chitin synthase genes throughout the midgut of M. domestica, S. frugiperda and Tenebrio molitor indicated that peritrophins were incorporated along the PM, according to their preferential sites of formation. Finally, the data support the view that mucus has functions distinct from the PM.

Phytophthora parasitica Effector PpRxLR2 Suppresses Nicotiana benthamiana Immunity.

Phytophthora species secrete several classes of effector proteins during interaction with their hosts. These proteins can have multiple functions including modulation of host physiology and immunity. The RxLR effectors have the ability to enter plant cells using the plant machinery. Some of these effectors have been characterized as immunity suppressors; however, very little is known about their functions in the interaction between Phytophthora parasitica and its hosts. Using a bioinformatics pipeline, we have identified 172 candidate RxLR effectors (CREs) in the isolate IAC 01_95 of P. parasitica. Of these 172 CREs, 93 were found to be also present in eight other genomes of P. parasitica, isolated from different hosts and continents. After transcriptomics and gene expression analysis, we have found five CREs to be up-regulated in in-vitro and in-planta samples. Subsequently, we selected three CREs for functional characterization in the model plant Nicotiana benthamiana. We show that PpRxLR2 is able to completely suppress INF-1-induced cell death, whereas PpRxLR3 and PpRxLR5 moderately suppressed N. benthamiana immunity in a less-extensive manner. Moreover, we confirmed the effector-triggered susceptibility activity of these proteins after transient transformation and infection of N. benthamiana plants. All three CREs enhanced virulence of P. parasitica during the interaction with N. benthamiana. These effectors, in particular PpRxLR2, can be targeted for the development of biotechnology-based control strategies of P. parasitica diseases.

Oxidative stress in mice treated with antileishmanial meglumine antimoniate.

In order to improve the understanding of the toxicity of pentavalent antimony (Sb(V)), we investigated the acute effects of meglumine antimoniate (MA) on the oxidative stress in heart, liver, kidney, spleen and brain tissue of mice. Levels of lipoperoxidation and protein carbonylation were measured to evaluate the oxidative status, whereas superoxide dismutase/catalase activity and glutathione levels were recorded to examine the antioxidative status. We observed that MA caused significant protein carbonylation in the heart, spleen and brain tissue. Increased lipoperoxidation was found in the liver and brain tissue. An imbalance between superoxide dismutase and catalase activities could be observed in heart, liver, spleen and brain tissue. Our results suggest that MA causes oxidative stress in several vital organs of mice. This indicates that the production of highly reactive oxygen and nitrogen species induced by MA might be involved in some of its toxic adverse effects.

Estimulação elétrica nervosa transcutânea (TENS) no pós-operatório de cesariana / Transcutaneous electrical nerve stimulation (TENS) following cesarean surgery

OBJETIVO: Verificar o efeito da aplicação da TENS no quadro álgico de pacientes submetidas à cirurgia de cesariana. MÉTODO: Foi utilizada uma amostragem de 30 mulheres, voluntárias, com faixa etária entre 16 e 35 anos, em período imediato de pós-operatório de cesariana, com a presença de dor abdominal e no baixo ventre, subdivididas em dois grupos A e B, contendo em cada um deles 15 mulheres, submetidas, respectivamente, à eletroestimulação e ao tratamento placebo por eletroestimulação. A rotina hospitalar de administração de fármacos não foi alterada e manteve-se similar em ambos os grupos. A corrente utilizada foi a TENS convencional (F= 100Hz e T= 50mis), com pulso bipolar assimétrico, que foi aplicada através de quatro eletrodos de borracha siliconada e carbonada, gel e fita adesiva para a fixação dos mesmos de forma peri-incisional em técnica bipolar com dois pares de eletrodos cruzados, após cessar o efeito da anestesia, por 50 minutos, com intensidade em um nível sensorial forte. A Escala Visual Analógica (EVA) foi utilizada para a quantificação da intensidade da dor antes e após a eletroestimulação. Para a análise dos dados foi aplicado o teste t de Student, para amostras pareadas, com um nível de significância de 5 por cento. RESULTADOS: Foi demonstrada uma diferença estatisticamente significante entre as intensidades da dor, antes e após a aplicação da TENS, apenas nos indivíduos participantes do grupo A. CONCLUSÃO: Levando em consideração as condições experimentais deste estudo, podemos concluir que a aplicação da TENS pode constituir mais um recurso usado em mulheres submetidas à cesariana.