Search results for "CELLULAR"
showing 10 items of 6449 documents
Dehydration of yeast: Changes in the intracellular content of Hsp70 family proteins
2008
Abstract Yeast is known to experience in natural and industrial conditions cycles of dehydration–rehydration. Several molecular mechanisms can be triggered in response to this and other environmental stressors and to rescue yeast cells of the cytotoxic effect. Since heat shock proteins constitute one of the most important systems of the response to stress we studied whether the pre-induced major stress protein, Hsp70, can cope with yeast cell drying. To induce Hsp70 expression the cells of two yeast species, Saccharomyces cerevisiae and Debaryomyces hansenii , were subjected to non-lethal heat shock. It was found that during yeast culture growth Hsp70 accumulation occurred at the exponentia…
Toxicity of the extracellular products ofVibrio damsela isolated from diseased fish
1993
In this work we analyzed the pathogenic in vivo and in vitro activities for both fish and mammals of extracellular products (ECP) of several isolates of Vibrio damsela implicated in disease problems in marine culture. The ECP from all the strains were strongly lethal for fish (LD50 ranging from 0.06 to 3.7 μg protein/g fish) and mice (LD50 ranging from 0.02 to 0.43 μg protein/g mouse), causing death between 4 and 72 h after inoculation. These ECP samples possessed low proteolytic activity without production of caseinase, gelatinase, or elastase. However, most of them showed remarkable phospholipase and hemolytic activity for sheep, human, and turbot red blood cells. In addition, all the ECP…
Pathogenesis of Atherosclerosis: The Alternative Hypothesis
1998
The concept that oxidation is the major single event underlying the transformation of LDL to a proinflammatory molecule dominates the world literature. An alternative hypothesis on the pathogenesis of atherosclerosis will be presented here. We have found that nonoxidative, enzymatic modification of LDL with ubiquitous enzymes also transforms the molecule to an atherogenic moiety. Enzymatically altered LDL (E-LDL) shares major properties in common with lipoproteins that have been isolated from atherosclerotic lesions. It activates complement and is recognized by a scavenger receptor on human macrophages, thus inducing foam cell formation. Uptake of E-LDL is accompanied by induction of MCP−1 …
GTPases of the Rho Subfamily Are Required for Brucella abortus Internalization in Nonprofessional Phagocytes
2001
Members of the genus Brucella are intracellular -Proteobacteria responsible for brucellosis, a chronic disease of humans and animals. Little is known about Brucella virulence mechanisms, but the abilities of these bacteria to invade and to survive within cells are decisive factors for causing disease. Transmission electron and fluorescence microscopy of infected nonprofessional phagocytic HeLa cells revealed minor membrane changes accompanied by discrete recruitment of F-actin at the site of Brucella abortus entry. Cell uptake of B. abortus was negatively affected to various degrees by actin, actin-myosin, and microtubule chemical inhibitors. Modulators of MAPKs and protein-tyrosine kinases…
An insect brain computational model inspired by Drosophila melanogaster: architecture description
2010
The fruit fly Drosophila melanogaster is an extremely interesting insect because it shows a wealth of complex behaviors, despite its small brain. Nowadays genetic techniques allow to knock out the function of defined parts or genes in the Drosophila brain. Together with specific mutants which show similar defects in those parts or genes, hypothesis about the functions of every single brain part can be drawn. Following these experiments, a computational model of the fly Drosophila has been designed with a view to its robotic implementation.
The Impact of Moyamoya Disease and
2019
Moyamoya disease (MMD) is a rare cerebrovascular disorder characterized by occlusion of bilateral internal carotid and intracerebral arteries with the compensatory growth of fragile small vessels. MMD patients develop recurrent infarctions in the basal ganglia and subcortical regions. Symptoms include transient ischemic attack or stroke, seizures, and headaches, which may occur suddenly or in a stepwise progression. Mutations in Ring Finger Protein 213 (RNF213), a Zinc ring finger protein, have been identified in some MMD patients but the etiology of MMD is still largely unknown. To gain insight into the pathophysiology of MMD, we characterized the impact of the RNF213 mutations on plasma p…
Synthetic/ECM-inspired hybrid platform for hollow microcarriers with ROS-triggered nanoporation hallmarks
2017
Reactive oxygen species (ROS) are key pathological signals expressed in inflammatory diseases such as cancer, ischemic conditions and atherosclerosis. An ideal drug delivery system should not only be responsive to these signals but also should not elicit an unfavourable host response. This study presents an innovative platform for drug delivery where a natural/synthetic composite system composed of collagen type I and a synthesized polythioether, ensures a dual stimuli-responsive behaviour. Collagen type I is an extracellular matrix constituent protein, responsive to matrix metalloproteinases (MMP) cleavage per se. Polythioethers are stable synthetic polymers characterized by the presence o…
Machine learning for land use change analysis and modelling.
2019
Urban development can take different forms or features, depending on its geographical location and its socioeconomic, political and cultural context. Nevertheless, the overall action relies on one fundamental principle: building construction in order to give people housing. Therefore, the main objective of this research is to determine whether an underlying universal aspect of the urban development process can be distinguished from a specific one, being the reflect of local specificities. Specifically, this research analyzes the land use change on the French-German cross-border area. Indeed, the border context enhances the difference within this territory. Nonetheless, the internal European…
Synergistic effects of neurons and astrocytes on the differentiation of brain capillary endothelial cells in culture
2003
Brain capillary endothelial cells form a functional barrier between blood and brain, based on the existence of tight junctions that limit paracellular permeability. Occludin is one of the major transmembrane proteins of tight junctions and its peripheral localization gives indication of tight junction formation. We previously reported that RBE4.B cells (brain capillary endothelial cells), cultured on collagen IV, synthesize occludin and correctly localize it at the cell periphery only when cocultured with neurons. In the present study, we describe a three-cell type-culture system that allowed us to analyze the combined effects of neurons and astrocytes on differentiation of brain capillary …