Search results for " Nitrogen"

Redox regulation of genome stability by effects on gene expression, epigenetic pathways and DNA damage/repair

2015

Reactive oxygen and nitrogen species (e.g. H2O2, nitric oxide) confer redox regulation of essential cellular signaling pathways such as cell differentiation, proliferation, migration and apoptosis. In addition, classical regulation of gene expression or activity, including gene transcription to RNA followed by translation to the protein level, by transcription factors (e.g. NF-κB, HIF-1α) and mRNA binding proteins (e.g. GAPDH, HuR) is subject to redox regulation. This review will give an update of recent discoveries in this field, and specifically highlight the impact of reactive oxygen and nitrogen species on DNA repair systems that contribute to genomic stability. Emphasis will be placed …

Effect of indoor nitrogen dioxide on lung function in urban environment

2015

BACKGROUND: High levels of indoor NO2 are associated with increased asthma symptoms and decreased expiratory peak flows in children. We investigated the association of exposure to domestic indoor NO2, objectively measured in winter and spring, with respiratory symptoms and lung function in a sample of adolescents from a southern Mediterranean area. METHODS: From a large school population sample (n=2150) participating in an epidemiological survey in the urban area of the City of Palermo (southern Italy), a sub-sample of 303 adolescents was selected which furnished an enriched sample for cases of current asthma. All subjects were evaluated by a health questionnaire, skin prick tests and spiro…

On the difficulty of assessing the specific surface area of magnesium stearate

2001

Abstract The water content of as-received commercial magnesium stearate batches from animal and vegetable sources have been modified by ageing in humid air at room temperature or by vacuum treatment. The complete adsorption–desorption isotherms of nitrogen and krypton vapours by samples of these as received and modified materials have been measured at liquid nitrogen temperature after standardised vacuum degassing. They are greatly affected by the initial water content of the material. In particular: (a) the BET surface area values computed from the adsorption branch vary widely and is increasing with increasing water content; (b) anomalous hysteresis of varying amplitude is observed in all…

Oxidative stress and antioxidants in the pathophysiology of malignant melanoma.

2018

Abstract The high number of somatic mutations in the melanoma genome associated with cumulative ultra violet (UV) exposure has rendered it one of the most difficult of cancers to treat. With new treatment approaches based on targeted and immune therapies, drug resistance has appeared as a consistent problem. Redox biology, including reactive oxygen and nitrogen species (ROS and RNS), plays a central role in all aspects of melanoma pathophysiology, from initiation to progression and to metastatic cells. The involvement of melanin production and UV radiation in ROS/RNS generation has rendered the melanocytic lineage a unique system for studying redox biology. Overall, an elevated oxidative st…

Even free radicals should follow some rules: a guide to free radical research terminology and methodology.

2014

Free radicals and oxidants are now implicated in physiological responses and in several diseases. Given the wide range of expertise of free radical researchers, application of the greater understanding of chemistry has not been uniformly applied to biological studies. We suggest that some widely used methodologies and terminologies hamper progress and need to be addressed. We make the case for abandonment and judicious use of several methods and terms and suggest practical and viable alternatives. These changes are suggested in four areas: use of fluorescent dyes to identify and quantify reactive species, methods for measurement of lipid peroxidation in complex biological systems, claims of…

Immune activation increases susceptibility to oxidative tissue damage in Zebra Finches.

2006

Summary 1The innate immune response involves the production of highly reactive molecules (reactive oxygen and nitrogen species, ROS and RNS). These toxic compounds can effectively destroy invading pathogens but can also, non-specifically, target host cells. Tissue damage caused by ROS and RNS can be substantial if the inflammatory response is overactive, potentially inducing a so-called immunopathology. 2In this study, we induced an inflammatory response in Zebra Finches by the way of a LPS injection (lipopolysaccharide of the cell wall of Escherichia coli), using as a control a group of birds injected with saline (phosphate-buffered saline). Body mass was measured both before and 24 h afte…

Reacción aza-Michael intramolecular organocatalítica sobre enonas y derivados de ácido: nuevas estrategias

2016

Una de les metodologies més importants, junt amb la reacció de Mannich, per la formació d’enllaços carboni-nitrogen i per accedir a compostos b-amino carbonílics, és la reacció aza-Michael, que consisteix en l’addició conjugada d’una font de nitrogen nucleòfila a un sistema a,b-insaturat. Aquesta reacció adquireix una especial rellevància a la seua versió intramolecular ja que condueix a la formació d’heterocicles nitrogenats de forma senzilla. A més, quan l’olefina activada conté centres proquirals, al procés d’addició es generen un o més centres estereogènics, pel que la versió asimètrica d’esta reacció permetria obtenir compostos nitrogenats funcionalitats de forma estereoselectiva. Ment…

Limiting immunopathology: Interaction between carotenoids and enzymatic antioxidant defences.

2015

The release of reactive oxygen and nitrogen species (ROS and RNS) during the inflammatory response generates damages to host tissues, referred to as immunopathology, and is an important factor in ecological immunology. The integrated antioxidant system, comprising endogenous antioxidant enzymes (e.g. superoxide dismutase SOD, and catalase CAT) and dietary antioxidants (e.g. carotenoids), helps to cope with immune-mediated oxidative stress. Crustaceans store large amounts of dietary carotenoids for yet unclear reasons. While being immunostimulants and antioxidants, the interaction of these pigments with antioxidant enzymes remains unclear. Here, we tested the interaction between dietary supp…

Dynamics of nitrogen uptake in young 'Nocellara del Belice' olive trees

2008

Nitric oxide synthase inhibition and oxidative stress in cardiovascular diseases: Possible therapeutic targets?

2013

International audience; Nitric oxide (• NO) is synthetized enzymatically from L-arginine (L-Arg) by three NO synthase isoforms, iNOS, eNOS and nNOS. The synthesis of NO is selectively inhibited by guanidino-substituted analogs of L-Arg or methylarginines such as asymmetric dimethylarginine (ADMA), which results from protein degradation in cells. Many disease states, including cardiovascular diseases and diabetes, are associated with increased plasma levels of ADMA. The N-terminal catalytic domain of these NOS isoforms binds the heme prosthetic group as well as the redox cofactor, tetrahydrobiopterin (BH 4) associated with a regulatory protein, calmodulin (CaM). The enzymatic activity of NOS…