1,721,327 research outputs found
Redox regulation of inflammatory processes
Full text linkOxidative stress mediators such as Reactive Oxygen Species (ROS) and Reactive Nitrogen Species (RNS) can be considered double edge molecules, whenever their role in inflammatory pathways is considered. Indeed, if on one hand ROS/RNS are important inflammatory effectors involved in the invading pathogens clearance and resolving the damage and inducing tissue repair; on the other hand, ROS/RNS can also be inflammatory initiators as a consequence of oxidizing biomolecules such as lipids, proteins and DNA, leading to tissue damage and switching acute to chronic inflammation.Fil: Valacchi, Giuseppe. Università di Ferrara; Italia. University of North Carolina; Estados UnidosFil: Cervellati, Carlo. Università di Ferrara; ItaliaFil: Evelson, Pablo Andrés. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Bioquímica y Medicina Molecular. Universidad de Buenos Aires. Facultad Medicina. Instituto de Bioquímica y Medicina Molecular; ArgentinaFil: Rahman, Irfan. University of Rochester; Estados Unido
Ozone and Skin: An Overview
No full textThe skin,a sa n interfaceb etweent he body andt he environmenti,s chronicallye xposedto stressfr om
bothU V radiationa nde nvironmentaolx idativep ollutants ucha sd iesefl uele xhaustc, igarette
smokeh, alogenatehdy drocarbonhse, avym etalsa nd0 3 (oneo f them ostt oxico f thesec ompounds)
Editorial: First International Conference on Environmental Stressors in Biology and Medicine – Siena, 4th–6th June 2008
No full textEditorial: First International Conference on Environmental Stressors in Biology and Medicine--Siena, 4th-6th June 200
Does Second Hand Cigarette Smoke modulate Lung Vitamin E uptake?
No full textCOPD (Chronic Obstructive Pulmonary Disease) is a chronic lung disease closely associated with cigarette smoke (CS). CS induces inflammation which is thought to cause oxidative stress and play a major role in COPD pathogeneses. We lack information on the delivery mechanisms of antioxidants to the lung. Scavenger Receptor B1 (SR-B1) has been shown to play a prominent role in the uptake of vitamin E (tocopherol) via HDL. We hypothesize that SR-B1 plays an important role in regulating the vitamin E delivery status of the lung. Our preliminary results indicate that young animal’s lung has higher SR-B1 levels than older animals and CS exposure lowers these levels of SR-B1 even further with the CS exposed old animal group having the lowest SR-B1. These provocative and novel results led us to hypothesize that CS and its attendant oxidative stress initiate a positive feedback loop consuming vitamin E, decreasing expression of SR-B1 and thereby hampering delivery of vitamin E to the lung. These issues will be addressed in mice studies that will 1) Quantitate SR-B1 and elucidate mechanisms responsible for the changes in lung SR-B1 and specifically in lung type II cells, in response to CS 2) Quantitate SR-B1 and elucidate mechanisms responsible for the changes in lung SR-B1 and specifically in lung type II cells, in response to changes in dietary vitamin E and 3) Quantitate SR-B1 and elucidate mechanisms responsible for the changes in lung SR-B1 and specifically in lung type II cells, upon combined CS exposure and vitamin E supplementation
Valacchi G. Effect of Ozone on Cutaneous Tissues
No full textLiving organisms are continuously exposed to environmental
pollutants. Depending on their state, pollutants
can be taken up by ingestion, inhalation, or contact with
the skin. Because the skin is an interface between the body
and the environment, it is chronically exposed to several
forms of stress such as ultraviolet (UV) radiation and
other environmental oxidants such as cigarette smoke
and ozone (O3). UVB and, to a lesser degree, UVA induce
various skin pathological conditions, including erythema,
edema, hyperplasia, ‘‘sunburn cell’’ formation, photoaging,
and photocarcinogenesis. There is abundant information
that reactive oxygen species (ROS) such as
hydroxyl radicals are involved in UV-induced skin damage,
both by direct effects of UV and by subsequent
phagocyte infiltration and activation. Oxidative environmental
pollutants, such as cigarette smoke, O3, and oxides
of nitrogen that have been studied in the respiratory tract, also represent a potential oxidant stress to the skin.
In order of importance, the skin is the second most frequent
route by which chemicals can enter into the body.
The skin is the major target of liquid and gaseous pollutants
and the pollutant that reacts most specifically with
the cutaneous tissues beside UV radiation, hydrocarbon,
and organic compounds in O3. Ozone represents one of
the major oxidants in photochemical smog, levels being
highest in heavily polluted areas where exposure to UV is
also high. In the last decade, many studies have shown the
toxic effect of O3 on the skin
Epidermis as a Shield from Radiation and Oxidative Stress
No full textThe skin consists of two main layers, the epidermis and the dermis. The dermis is superficial to the subcutaneous fat tissue and is reachable by blood capillaries. Dermal fibroblasts synthesize a complex extracellular matrix containing collagenous and elastic fibers. The epidermis contains mostly keratinocytes that rise to the skin surface as they differentiate progressively to form the non-nucleated corneocytes that consists of the superficial part of the epidermis, the stratum corneum (SC). The SC comprises a unique two-compartment system of structural, nonnuclated cells (corneocytes) embedded in a lipid-enriched intercellular matrix, forming stacks of bilayers that are rich in ceramides, cholesterol and free fatty acids. SC functions as a physiochemical barrier to protect and prevent water loss from the epidermis, maintaining its integrity, and to provide protection from the environment by producing antioxidant molecules which interact with reactive oxygen species (ROS) or their by-products to either eliminate or to minimize their deleterious effects. The SC supports the absorption of liposoluble compounds and promotes the penetration of lipophilic molecules. There are several ways how molecules can penetrate in the SC such as: intercellular (penetration between the corneocytes), transcellular (penetration through the keratinized corneocytes), intrafollicular (penetration through hair follicles), and/or polar (penetration between polar pores) (Pouillot, et al., 2008). Physiochemical factors which regulate penetration include molecular mass, concentration, solubility, partition coefficient, pH variations, co-solvents, temperature, and enhancers.
Because of its critical location, the SC is a major interface between the body and the environment and provides a biological barrier against an array of chemical and physical environmental pollutants. Due to the constant exposure to oxidants including ultraviolet (UV) radiation and other environmental pollutants such as diesel fuel exhaust, cigarette smoke (CS), halogenated hydrocarbons, heavy metals and O3 (one of the most toxic of these compounds, the SC can be defined as our first defense against the outdoor environment
Studies on the biological effects of ozone: 10. Release of factors from ozonated human platelets
No full textIn a previous work we have shown that heparin, in the presence of ozone (O3), promotes a dose-dependent platelet aggregation, while after Ca2+ chelation with citrate, platelet aggregation is almost negligible. These results led us to think that aggregation may enhance the release of platelet components. We have here shown that indeed significantly higher amount of platelet-derived growth factor (PDGF), transforming growth factor beta1 (TGF-beta1) and interleukin-8 (IL-8) are released in a dose-dependent manner after ozonation of heparinised platelet-rich plasma samples. These findings may explain the enhanced healing of torpid ulcers in patients with chronic limb ischemia treated with O3 autohaemoteraphy (O3-AHT)
The air quality health index and emergency department visits for urticaria in Windsor, Canada
No full textAmbient air pollution exposure has been associated with several health conditions, limited not only to respiratory and cardiovascular systems but also to cutaneous tissues. However, few epidemiological studies examined pollution exposure on skin problems. Basically, the common mechanism by which pollution may affect skin physiology is by induction of oxidative stress and inflammation. Urticaria is among the skin pathologies that have been associated with pollution. Based on the combined effects of three ambient air pollutants, ozone (O3), nitrogen dioxide (NO2), and fine particulate matter (PM) with a median aerodynamic diameter of less than 2.5 μm (PM(2.5)), on mortality, the Air Quality Health Index (AQHI) in Canada was developed. The aim of this study was to examine the associations of short-term changes in AQHI with emergency department (ED) visits for urticaria in Windsor-area hospitals in Canada. Diagnosed ED visits were retrieved from the National Ambulatory Care Reporting System (NACRS). A time-stratified case-crossover design was applied to 2905 ED visits (males = 1215; females = 1690) for urticaria from April 2004 through December 2010. Odds ratios (OR) and their corresponding 95% confidence intervals (95%CI) for ED visits associated with increase by one unit of risk index were calculated employing conditional logistic regression. Positive and significant results were observed between AQHI levels and OR for ED visits for urticaria in Windsor for lags 2 and 3 days. A distributed lag nonlinear model technique was applied to daily counts of ED visits for lags 0 to 10 and significant results were obtained from lag 2 to lag 5 and for lag 9. These findings demonstrated associations between ambient air pollution and urticarial confirming that air pollution affects skin conditions
Synthesis and evaluation of indole based molecules for treatment of oxidative stress related diseases
No full textThe chemical versatility of the indole nucleus still inspires the pharmaceutical research to develop innovative suitable indole based drugs. The present work is an overview of the use and application of indole molecule based derivatives, as possible treatment in the main Oxidative Stress related diseases, such as cardiovascular, neurological, and cancer. The indole nucleus is a particular class of reducers, very efficient when bearing aliphatic substitutions in position 3, like that found in tryptophan (Trp). The principal chemical modifications carried out on the indole nucleus, were focused to obtain orally active drugs for a simpler delivery to the patients
Antioxidants and the response of skin to oxidative stress: Vitamin E as a key indicator
No full textAs the outermost barrier of the body, the skin is directly and frequently exposed to a prooxidative environment, including solar UVA and UVB radiation, and air pollution. The skin is equipped with an elaborate system of antioxidant substances and enzymes that includes a network of redox active antioxidants. Among these, vitamin E has been identified as the predominant antioxidant both in murine and human skin and shows a characteristic gradient with lower levels towards the outer stratum corneum layers. Skin exposure to UV and ozone alone and in combination resulted in a significant potentiation of the UV-induced vitamin E depletion. Oxidants and antioxidants play an important role in maintaining a balance between free radicals produced by metabolism or derived from environmental sources. Cellular antioxidants may change their redox state, be targeted for destruction, regulate oxidative process involved in signal transduction, affect gene expression and pathways of cell proliferation and death. Here we provide an overview of the antioxidant system with a special relevance to skin
- …
