Search results for " Biochimica"

Plexin-B1 and Semaphorin 4D Cooperate to Promote Perineural Invasion in a RhoA/ROK-Dependent Manner

2012

Perineural invasion (PNI) is a tropism of tumor cells for nerve bundles located in the surrounding stroma. It is a pathological feature observed in certain tumors, referred to as neurotropic malignancies, that severely limits the ability to establish local control of disease and results in pain, recurrent growth, and distant metastases. Despite the importance of PNI as a prognostic indicator, its biological mechanisms are poorly understood. The semaphorins and their receptors, the plexins, compose a family of proteins originally shown to be important in nerve cell adhesion, axon migration, and proper central nervous system development. Emerging evidence has demonstrated that these factors a…

Extracellular Membrane Vesicles as Vehicles for Brain Cell-to-Cell Interactions in Physiological as well as Pathological Conditions.

2015

Extracellular vesicles are involved in a great variety of physiological events occurring in the nervous system, such as cross talk among neurons and glial cells in synapse development and function, integrated neuronal plasticity, neuronal-glial metabolic exchanges, and synthesis and dynamic renewal of myelin. Many of these EV-mediated processes depend on the exchange of proteins, mRNAs, and noncoding RNAs, including miRNAs, which occurs among glial and neuronal cells. In addition, production and exchange of EVs can be modified under pathological conditions, such as brain cancer and neurodegeneration. Like other cancer cells, brain tumours can use EVs to secrete factors, which allow escaping…

Defining the role of common variation in the genomic and biological architecture of adult human height

2014

Item does not contain fulltext Using genome-wide data from 253,288 individuals, we identified 697 variants at genome-wide significance that together explained one-fifth of the heritability for adult height. By testing different numbers of variants in independent studies, we show that the most strongly associated approximately 2,000, approximately 3,700 and approximately 9,500 SNPs explained approximately 21%, approximately 24% and approximately 29% of phenotypic variance. Furthermore, all common variants together captured 60% of heritability. The 697 variants clustered in 423 loci were enriched for genes, pathways and tissue types known to be involved in growth and together implicated genes…

Triiodothyronine-Induced Shortening of Chromatin Repeat Length in Neurons Cultured in a Chemically Denned Medium

1987

Abstract: At the time of terminal differentiation, mammalian cortical neurons undergo a dramatic change in the structural organization of their chromatin: the nucleosomal repeat length shortens from ∼200 base pairs in fetuses to a value of 165 base pairs after birth. These events occur several days after the end of neuronal proliferation. Previously, we reported that rat cortical neurons cultured in a very selective synthetic medium were not yet programmed to these events at the end of mitotic cycles. Herein, we report that addition of triiodothyronine to neuronal cultures induces a shortening of the chromatin repeat length comparable to the natural one. Copyright © 1987, Wiley Blackwell. A…

Comparative study on enzymatic activity and molecules stability of some commercial proteolytic enzymes used in pancreatic islet isolation.

2009

In pancreatic islets purification, for cell therapy applications, the major enzymes used are obtained from Clostridium hystoliticum; class I and class II collagenases (COLL G and COLL H). They are used in a defined tissue dissociation enzyme (TDE) mixtures together neutral protease (Dispase) or thermolysin (Thermostable Neutral Protease). The TDE mixtures were in part responsible for the success of the Edmonton protocol; however, just to now, people working in islets purification found discrepancy in an application to another one. This variability in application see in the enzymatic blend composition the higher accused, such as the contamination from endotoxines due to extractive production…

Impact of heteroptera pentatomidae feeding and oviposition on photosynthesis of herbaceous plants and egg parasitoids host location

2009

The present study was designed to examine the effect of heteroptera pentatomidae feeding and/or oviposition on photosynthesis. Murgantia histrionica and Nezara viridula were fed on Brassica and Phaseolus plants, respectively. The changes in photosynthetic gas exchange and chlorophyll fluorescence parameters were followed immediately after the feeding as well as during the post-feeding period (24, 48 and 72 h). Murgantia feeding caused visible damage on leaf lamina, whereas this was not the case with Nezara feeding. In both cases a substantial decrease (50%) in photosynthesis was observed, which was partially restored only in Phaseolus plants by the end of the experiment. By using high resol…

COMPOSITION AND EFFECTS OF EXTRACELLULAR VESICLES SHED BY OLIGODENDROGLIOMA CELLS

2011

Regeneration of total RNA purification silica-based columns

2010

Silica-based columns are largely used in RNA purification, allowing fast extractions and good yields of high quality nucleic acid, but their major limitation is the high cost. The reuse of such columns, although desirable, is not recommended because of residual amounts of material from the previous sample trapped in the column matrix, which might be released during further purification. Thus, recycling does need previous complete removal of any detectable RNA trace, but to date no protocol which allows decontamination and reuse is available.We report a very rapid decontamination procedure, based on treatment with warm alkaline solution containing Triton X-100, which ensures no RNA carry-ove…

Protective Effect of Sildenafil against Estradiol-induced ROS production

2010

Several reports suggest that xanthine dehydrogenase (XDH) and its oxidase form (XO) play an important role in various forms of ischemic and vascular injuries. Recently we have demonstrated that 17β-estradiol (E2) induces a significant decrease of the expression and activity of XDH and its conversion to XO in human mammary epithelial cells. E2 is known to induce upregulation of eNOS gene expression in aortic endothelial cells. In light of the ability of XO-derived O2•¯ to combine with •NO to yield ONOO¯, and considering that ONOO¯ converts XDH to XO, it is important to protect tissues against the XO increased activity and ROS increased production, that would in turn react with •NO to augment…

Microvesicles shed by oligodendroglioma cells and rheumatoid synovial fibroblasts contain aggrecanase activity

2012

Membrane microvesicle shedding is an active process and occurs in viable cells with no signs of apoptosis or necrosis. We report here that microvesicles shed by oligodendroglioma cells contain an ‘aggrecanase’ activity, cleaving aggrecan at sites previously identified as targets for adamalysin metalloproteinases with disintegrin and thrombospondin domains (ADAMTSs). Degradation was inhibited by EDTA, the metalloproteinase inhibitor GM6001 and by tissue inhibitor of metalloproteinases (TIMP)-3, but not by TIMP-1 or TIMP-2. This inhibitor profile indicates that the shed microvesicles contain aggrecanolytic ADAMTS(s) or related TIMP-3-sensitive metalloproteinase(s). The oligodendroglioma cells…