Search results for "STRESS"
showing 10 items of 6278 documents
Regulation of the effects of CYP2E1-induced oxidative stress by JNK signaling
2014
The generation of excessive amounts of reactive oxygen species (ROS) leads to cellular oxidative stress that underlies a variety of forms of hepatocyte injury and death including that from alcohol. Although ROS can induce cell damage through direct effects on cellular macromolecules, the injurious effects of ROS are mediated largely through changes in signal transduction pathways such as the mitogen-activated protein kinase c-Jun N-terminal kinase (JNK). In response to alcohol, hepatocytes have increased levels of the enzyme cytochrome P450 2E1 (CYP2E1) which generates an oxidant stress that promotes the development of alcoholic steatosis and liver injury. These effects are mediated in larg…
Mitochondrial function in liver disease.
2006
Oxidative stress is involved in the pathogenesis and progression of different liver diseases, such as alcoholic liver disease and biliary cirrhosis. The increased mitochondrial production of O2(-) at complexes I and III, and consequently of H2O2 and other reactive oxygen species (ROS), triggered by NADH overproduction seems the major cause of mitochondrial and cellular oxidative stress and damage in chronic alcoholism. The mitochondrial oxidative stress renders hepatocytes susceptible to ethanol- or acetaldehyde-induced mitochondrial membrane permeability transition (MMPT) and apoptosis. Nitrosative stress contributes to cell death by peroxynitrite formation. The expression of the death rec…
Glutathione-dependent formaldehyde dehydrogenase (ADH3) and low km mitochondrial aldehyde dehydrogenase (ALDH2). New evidence for differential expres…
2011
Epidemiological and experimental studies support the involvement of lipid peroxidation (LPO) in retinal diseases. In addition to other pathogenic mechanisms not fully understood, the possibility remains that peroxidic aldehydes, acting as cytotoxic chemicals, mediate in the progression of chronic ocular disorders.To test proper mechanisms involved in removing peroxidic aldehydes from the retina, in an attempt to understand long-lasting changes induced by LPO, the oxidative and antioxidant enzymatic activities, as well as the retinal distribution and activity of glutathione-dependent formaldehyde dehydrogenase (ADH3) and low km mitochondrial aldehyde dehydrogenase (ALDH2), were studied and c…
Mitochondrial aldehyde dehydrogenase (ALDH-2)--maker of and marker for nitrate tolerance in response to nitroglycerin treatment.
2008
The hemodynamic and anti-ischemic effects of nitroglycerin (GTN) are rapidly blunted as a result of the development of nitrate tolerance. Long-term nitrate treatment also is associated with decreased vascular responsiveness caused by changes in intrinsic mechanisms of the tolerant vasculature itself. According to the oxidative stress concept, increased vascular superoxide and peroxynitrite production as well as an increased sensitivity to vasoconstrictors secondary to activation of protein kinase C as well as vascular NADPH oxidases contribute to the development of tolerance. Recent experimental work has defined new tolerance mechanisms, including inhibition of the enzyme that bioactivates …
Darba stresa saistība ar apreibinošo vielu lietošanu pavāriem
2021
Bakalaura darba mērķis ir noskaidrot, vai pastāv darba stresa saistība ar apreibinošo vielu lietošanu pavāriem. Darba ietvaros tika pētīti un apkopoti tādi zinātniskie raksti un pētījumi, kas pēc savas būtības apskata stresu, darba stresu, stresa pārvarēšanas stratēģijas un alohola lietošanas paradumus, kā arī pavāra profesijas specifiskās īpatnības. Šī bakalaura darba ietvaros tika aptaujāti 60 respondenti, vecumā no 18 līdz 56 gadiem. 30 respondenti bija vīrieši un 26 bija sievietes. Vīriešu grupā vidējais vecums bija 38,8 gadi, bet sievietēm 30,7 gadi. Aptaujai tika izmantoti divi mērinstrumenti: Darba stresoru skalas (JSS - Job Stressor Scales, Paul E. Spector & Jex, 1997) un Alkohola l…
Telomere attrition in peripheral blood mononuclear cells of children with alpha-1 antitrypsin deficiency
2015
Background: Our research group have demonstrated that oxidative stress (OS) is involved in the pathophysiology of alpha-1 antitrypsin deficiency (AATD) (Escribano A. et al. Thorax 2015;70:82-3). In addition, many evidences have shown that OS accelerates telomere shortening in several lung pathologies. Short telomeres have been associated to higher emphysema risk in COPD patients. Rationale: Since AATD is characterised by chronic OS, we hypothesise that telomere shortening would be accelerated in AATD patients and would be associated with higher risk of developing lung disease. Aims: To assess telomere length (TL) in AATD patients and to study its association with AAT phenotypes. Methods: TL…
Usefulness of salivary alpha amylase as a biomarker of chronic stress and stress related oral mucosal changes ' a pilot study
2013
Introduction: Salivary biomarkers are suggested to provide a reliable, noninvasive and objective measurement of chronic psychosocial stress and helps in assessment of pivotal role of stress in causation or precipitation of multitude of health problems. Objectives: To evaluate the usefulness of salivary alpha amylase activity as an objective indicator of chronic stress and to find out any correlation between stress- related mucosal complaints and its levels. Study Design: Study was conducted among 50 subjects suffering from chronic stress related problems and 50 non-stressed individuals who were screened with a psychometric questionnaire. Brief case history and oral examination was carried o…
Cellular stress induces cap-independent alpha-enolase/MBP-1 translation.
2015
AbstractMyc promoter-binding protein-1 (MBP-1) is a shorter protein variant of the glycolytic enzyme alpha-enolase. Although several lines of evidence indicate that MBP-1 acts as a tumor suppressor, the cellular mechanisms and signaling pathways underlying MBP-1 expression still remain largely elusive. To dissect these pathways, we used the SkBr3 breast cancer cell line and non-tumorigenic HEK293T cells ectopically overexpressing alpha-enolase/MBP-1. Here, we demonstrate that induced cell stresses promote MBP-1 expression through the AKT/PERK/eIF2α signaling axis. Our results contribute to shedding light on the molecular mechanisms underlying MBP-1 expression in non-tumorigenic and cancer c…
Shear coefficient determination in linear friction welding of aluminum alloys
2015
In the present study, a combined experimental and numerical investigation on Linear Friction Welding (LFW) of AA2011-T3 aluminum alloy was carried out in order to find the temperature dependent shear coefficient to be used in a 3D numerical model of the process. Torque, oscillation frequency and pressure were acquired in order to calculate the shear stress at the interface. A numerical thermal model was used to calculate the temperature at the interface between the specimens starting from experimental temperatures acquired through a thermocouple embedded in the LFW specimens. Finally, the calculated shear coefficient was used to model the contact between the two specimens in a dedicated 3D,…
Hypertonic Stress and Amino Acid Deprivation Both Increase Expression of mRNA for Amino Acid Transport System A
2004
The activity of amino acid transport system A ([Oxender and Christensen, 1963][1]) is regulated in a variety of different ways, the best studied being the increases of its activity caused by starving cells of amino acids or by exposing them to hypertonicity (for review see [McGivan and Pastor-