Distributional theory for the DIA method

The DIA method for the detection, identification and adaptation of model misspecifications combines estimation with testing. The aim of the present contribution is to introduce a unifying framework for the rigorous capture of this combination. By using a canonical model formulation and a partitioning of misclosure space, we show that the whole estimation–testing scheme can be captured in one single DIA estimator. We study the characteristics of this estimator and discuss some of its distributional properties. With the distribution of the DIA estimator provided, one can then study all the characteristics of the combined estimation and testing scheme, as well as analyse how they propagate into final outcomes. Examples are given, as well as a discussion on how the distributional properties compare with their usage in practice

Bacterial Inclusion Bodies Contain Amyloid-Like Structure

Protein aggregation is a process in which identical proteins self-associate into imperfectly ordered macroscopic entities. Such aggregates are generally classified as amorphous, lacking any long-range order, or highly ordered fibrils. Protein fibrils can be composed of native globular molecules, such as the hemoglobin molecules in sickle-cell fibrils, or can be reorganized β-sheet–rich aggregates, termed amyloid-like fibrils. Amyloid fibrils are associated with several pathological conditions in humans, including Alzheimer disease and diabetes type II. We studied the structure of bacterial inclusion bodies, which have been believed to belong to the amorphous class of aggregates. We demonstrate that all three in vivo-derived inclusion bodies studied are amyloid-like and comprised of amino-acid sequence-specific cross-β structure. These findings suggest that inclusion bodies are structured, that amyloid formation is an omnipresent process both in eukaryotes and prokaryotes, and that amino acid sequences evolve to avoid the amyloid conformation

Effects of high glucose concentration on the recycling of b1-containing integrins in fibroblasts.

Introdução: In vivo ou in vitro a exposição de fibroblastos a alta concentração de glicose promove um aumento do estresse oxidativo e consequentemente prejudica a migração celular, assim como a maturação da adesão. Além disso, a elevada concentração de glicose reduz a expressão de diferentes integrinas na superfície celular devido alterações na síntese do receptor e sua reciclagem. Objetivo: Avaliar os efeitos da elevada concentração de glicose no tráfego de vesículas contendo EEA1 (endossomos primários), Rab4 (via rápida da reciclagem), Rab11 (via lenta de reciclagem) e Rab7 (endossomos de degradação) em fibroblastos NIH3T3. Métodos: células foram cultivadas em meio contendo baixa concentração de glicose (LG, 5 mM) ou em alta concentração (HG 25 mM) durante 21 dias antes de realizar os experimentos. EEA1, Rab4, Rab11 e Rab7 expressão e distribuição foram avaliados por western blotting e imunofluorescência, respectivamente. Resultados: Células expostas à alta concentração não apresentaram diferenças na expressão e distribuição das proteínas EEA1 e Rab7, enquanto a expressão de Rab11 foi reduzida em 30%. Conclusão: a alta concentração de glicose altera a via lenta da reciclagem contendo Rab11, afetando potencialmente a reciclagem de integrinas e outros receptores e a sua expressão na superfície celular.Background: In vivo or in vitro exposure of fibroblasts to high glucose concentrations (HG) promotes oxidative stress and consequently impairs cell migration, also inhibiting adhesion maturation. Additionally, HG reduces the expression of different integrins on the cell surface, potentially due to altered receptor synthesis and recycling. Aim: to evaluate the effects of HG on the trafficking vesicles containing EEA1 (early endosomes), Rab4 (fast recycling pathway) and Rab7 (endocytic degradation pathway) on NIH3T3 fibroblasts. Methods: cells were cultured under low glucose (LG, 5 mM) or HG (25 mM) concentrations during 21 days before the assays. EEA1, Rab4 and Rab7 expression and distribution were evaluated by western blotting and immunofluorescence, respectively. Results: HG did not affect proteins EEA1 and Rab7 expression and distribution, whereas Rab11 expression was reduced by 30%. The number of vesicles containing Rab11 was also significantly reduced in HG cells. Conclusion: high glucose alters the slow recycling endocytic pathway via Rab11, potentially affecting integrins and other receptors synthesis and expression on the cell surface