Tuning the endothelial response: differential release of exocytic cargos from Weibel-Palade bodies.

Essentials Endothelial activation initiates multiple processes, including hemostasis and inflammation. The molecules that contribute to these processes are co-stored in secretory granules. How can the cells control release of granule content to allow differentiated responses? Selected agonists recruit an exocytosis-linked actin ring to boost release of a subset of cargo. SUMMARY: Background Endothelial cells harbor specialized storage organelles, Weibel-Palade bodies (WPBs). Exocytosis of WPB content into the vascular lumen initiates primary hemostasis, mediated by von Willebrand factor (VWF), and inflammation, mediated by several proteins including P-selectin. During full fusion, secretion of this large hemostatic protein and smaller pro-inflammatory proteins are thought to be inextricably linked. Objective To determine if secretagogue-dependent differential release of WPB cargo occurs, and whether this is mediated by the formation of an actomyosin ring during exocytosis. Methods We used VWF string analysis, leukocyte rolling assays, ELISA, spinning disk confocal microscopy, high-throughput confocal microscopy and inhibitor and siRNA treatments to demonstrate the existence of cellular machinery that allows differential release of WPB cargo proteins. Results Inhibition of the actomyosin ring differentially effects two processes regulated by WPB exocytosis; it perturbs VWF string formation but has no effect on leukocyte rolling. The efficiency of ring recruitment correlates with VWF release; the ratio of release of VWF to small cargoes decreases when ring recruitment is inhibited. The recruitment of the actin ring is time dependent (fusion events occurring directly after stimulation are less likely to initiate hemostasis than later events) and is activated by protein kinase C (PKC) isoforms. Conclusions Secretagogues differentially recruit the actomyosin ring, thus demonstrating one mechanism by which the prothrombotic effect of endothelial activation can be modulated. This potentially limits thrombosis whilst permitting a normal inflammatory response. These results have implications for the assessment of WPB fusion, cargo-content release and the treatment of patients with von Willebrand disease.

Honey Bees of Santa Catarina, Brazil, have only African mitochondrial DNA / Abelhas de Santa Catarina, Brasil, possuem apenas DNA mitocondrial africano

As diferenças entre a subspécie de abelha africana (Apis mellifera scutellata) e as subspécies europeias (Apis mellifera mellifera e Apis mellifera ligustica) nos quesitos comportamento higiênico e agressividade são marcantes. Diferenças acentuadas no comportamento higiênico entre colônias de abelhas foram relatadas em Santa Catarina, Brasil. Suspeitou-se que essas diferenças fossem devidas a um possível fluxo gênico entre as abelhas africanizadas brasileiras e as abelhas europeias da Argentina. Amostras de abelhas de 30 localidades de Santa Catarina foram analisadas por meio do uso de um marcador PCR-RFLP do DNA mitocondrial específico para identificação da origem da linhagem maternal. Os resultados indicaram ausência de linhagem materna de origem europeia em Santa Catarina. Baseando-se em hipóteses e resultados de trabalhos anteriores, conclui-se que não há fluxo gênico entre as populações das diferentes subespécies. O resultado também reforça que a eliminação do DNA maternal europeu é um indicativo de ineficácia de introduções de abelhas de subespécies europeias, no Brasil, com propósitos de melhoramento do atributo agressividade.

Effect of the glycemic index on lipid oxidation and body composition.

Several studies have been conducted to evaluate the effects of the consumption of the slowly absorbed carbohydrates in a low glycemic index (GI) diet on fat oxidation, in order to obtain dietetic treatment that can favor the achievement of an adequate body composition. Therefore, the purpose of this study was to analyze studies in which the role of low GI diets on body composition, with emphasis on fat oxidation. An internet search for articles, in English or Portuguese, published since 1995, was conducted using the following key words: glycemic index, glycemic load, glycaemic index, glycaemic load, body fat, body composition, fat oxidation. Papers that described animals or humans clinical trials were selected. Data were collected from Web of Science, Science Direct, Pubmed. It was verified that the results of the majority of the analyzed studies indicated that low GI diets lead to a lower insulin response, increasing body fat oxidation. These results indicate that the consumption of low GI diet can be an important strategy to be used for the prevention and control of obesity and chronic diseases associated to it.

African swine fever in Mozambique: review, risk factors and considerations for control.

African swine fever (ASF) is the most important disease that constrains pig production in Mozambique. Until 1994 it was apparently restricted to the central and northern provinces, but since 1994 outbreaks have been experienced throughout the country. ASF causes severe economic losses both in the small commercial sector and among the large numbers of small-scale producers in the family sector in rural and peri-urban areas. The history of ASF in Mozambique since its first confirmation in 1960 is briefly reviewed, recent outbreaks are reported, and the available information on the virus genotypes that have been responsible for some of the outbreaks is presented. Epidemiological factors that contribute to ASF outbreaks and strategies for limiting the negative effects of the disease in the different pig farming sectors in Mozambique, including raising farmer and community awareness, are discussed.