Reactive oxygen species. Medical search

Molecules or ions formed by the incomplete one-electron reduction of oxygen. These reactive oxygen intermediates include SINGLET OXYGEN; SUPEROXIDES; PEROXIDES; HYDROXYL RADICAL; and HYPOCHLOROUS ACID. They contribute to the microbicidal activity of PHAGOCYTES, regulation of signal transduction and gene expression, and the oxidative damage to NUCLEIC ACIDS; PROTEINS; and LIPIDS.

An element with atomic symbol O, atomic number 8, and atomic weight [15.99903; 15.99977]. It is the most abundant element on earth and essential for respiration.

A disturbance in the prooxidant-antioxidant balance in favor of the former, leading to potential damage. Indicators of oxidative stress include damaged DNA bases, protein oxidation products, and lipid peroxidation products (Sies, Oxidative Stress, 1991, pxv-xvi).

A strong oxidizing agent used in aqueous solution as a ripening agent, bleach, and topical anti-infective. It is relatively unstable and solutions deteriorate over time unless stabilized by the addition of acetanilide or similar organic materials.

Naturally occurring or synthetic substances that inhibit or retard the oxidation of a substance to which it is added. They counteract the harmful and damaging effects of oxidation in animal tissues.

A flavoprotein enzyme that catalyzes the univalent reduction of OXYGEN using NADPH as an electron donor to create SUPEROXIDE ANION. The enzyme is dependent on a variety of CYTOCHROMES. Defects in the production of superoxide ions by enzymes such as NADPH oxidase result in GRANULOMATOUS DISEASE, CHRONIC.

Substances that influence the course of a chemical reaction by ready combination with free radicals. Among other effects, this combining activity protects pancreatic islets against damage by cytokines and prevents myocardial and pulmonary perfusion injuries.

Semiautonomous, self-reproducing organelles that occur in the cytoplasm of all cells of most, but not all, eukaryotes. Each mitochondrion is surrounded by a double limiting membrane. The inner membrane is highly invaginated, and its projections are called cristae. Mitochondria are the sites of the reactions of oxidative phosphorylation, which result in the formation of ATP. They contain distinctive RIBOSOMES, transfer RNAs (RNA, TRANSFER); AMINO ACYL T RNA SYNTHETASES; and elongation and termination factors. Mitochondria depend upon genes within the nucleus of the cells in which they reside for many essential messenger RNAs (RNA, MESSENGER). Mitochondria are believed to have arisen from aerobic bacteria that established a symbiotic relationship with primitive protoeukaryotes. (King & Stansfield, A Dictionary of Genetics, 4th ed)

The rate at which oxygen is used by a tissue; microliters of oxygen STPD used per milligram of tissue per hour; the rate at which oxygen enters the blood from alveolar gas, equal in the steady state to the consumption of oxygen by tissue metabolism throughout the body. (Stedman, 25th ed, p346)

An oxidoreductase that catalyzes the reaction between superoxide anions and hydrogen to yield molecular oxygen and hydrogen peroxide. The enzyme protects the cell against dangerous levels of superoxide. EC 1.15.1.1.

A chemical reaction in which an electron is transferred from one molecule to another. The electron-donating molecule is the reducing agent or reductant; the electron-accepting molecule is the oxidizing agent or oxidant. Reducing and oxidizing agents function as conjugate reductant-oxidant pairs or redox pairs (Lehninger, Principles of Biochemistry, 1982, p471).

An oxidoreductase that catalyzes the conversion of HYDROGEN PEROXIDE to water and oxygen. It is present in many animal cells. A deficiency of this enzyme results in ACATALASIA.

The N-acetyl derivative of CYSTEINE. It is used as a mucolytic agent to reduce the viscosity of mucous secretions. It has also been shown to have antiviral effects in patients with HIV due to inhibition of viral stimulation by reactive oxygen intermediates.

Highly reactive compounds produced when oxygen is reduced by a single electron. In biological systems, they may be generated during the normal catalytic function of a number of enzymes and during the oxidation of hemoglobin to METHEMOGLOBIN. In living organisms, SUPEROXIDE DISMUTASE protects the cell from the deleterious effects of superoxides.

Electron-accepting molecules in chemical reactions in which electrons are transferred from one molecule to another (OXIDATION-REDUCTION).

One of the mechanisms by which CELL DEATH occurs (compare with NECROSIS and AUTOPHAGOCYTOSIS). Apoptosis is the mechanism responsible for the physiological deletion of cells and appears to be intrinsically programmed. It is characterized by distinctive morphologic changes in the nucleus and cytoplasm, chromatin cleavage at regularly spaced sites, and the endonucleolytic cleavage of genomic DNA; (DNA FRAGMENTATION); at internucleosomal sites. This mode of cell death serves as a balance to mitosis in regulating the size of animal tissues and in mediating pathologic processes associated with tumor growth.

The voltage difference, normally maintained at approximately -180mV, across the INNER MITOCHONDRIAL MEMBRANE, by a net movement of positive charge across the membrane. It is a major component of the PROTON MOTIVE FORCE in MITOCHONDRIA used to drive the synthesis of ATP.

A tripeptide with many roles in cells. It conjugates to drugs to make them more soluble for excretion, is a cofactor for some enzymes, is involved in protein disulfide bond rearrangement and reduces peroxides.

Cells propagated in vitro in special media conducive to their growth. Cultured cells are used to study developmental, morphologic, metabolic, physiologic, and genetic processes, among others.

The intracellular transfer of information (biological activation/inhibition) through a signal pathway. In each signal transduction system, an activation/inhibition signal from a biologically active molecule (hormone, neurotransmitter) is mediated via the coupling of a receptor/enzyme to a second messenger system or to an ion channel. Signal transduction plays an important role in activating cellular functions, cell differentiation, and cell proliferation. Examples of signal transduction systems are the GAMMA-AMINOBUTYRIC ACID-postsynaptic receptor-calcium ion channel system, the receptor-mediated T-cell activation pathway, and the receptor-mediated activation of phospholipases. Those coupled to membrane depolarization or intracellular release of calcium include the receptor-mediated activation of cytotoxic functions in granulocytes and the synaptic potentiation of protein kinase activation. Some signal transduction pathways may be part of larger signal transduction pathways; for example, protein kinase activation is part of the platelet activation signal pathway.

Peroxidase catalyzed oxidation of lipids using hydrogen peroxide as an electron acceptor.

Ions with the suffix -onium, indicating cations with coordination number 4 of the type RxA+ which are analogous to QUATERNARY AMMONIUM COMPOUNDS (H4N+). Ions include phosphonium R4P+, oxonium R3O+, sulfonium R3S+, chloronium R2Cl+

Nitrogenous products of NITRIC OXIDE synthases, ranging from NITRIC OXIDE to NITRATES. These reactive nitrogen intermediates also include the inorganic PEROXYNITROUS ACID and the organic S-NITROSOTHIOLS.

An excited state of molecular oxygen generated photochemically or chemically. Singlet oxygen reacts with a variety of biological molecules such as NUCLEIC ACIDS; PROTEINS; and LIPIDS; causing oxidative damages.

An iron-molybdenum flavoprotein containing FLAVIN-ADENINE DINUCLEOTIDE that oxidizes hypoxanthine, some other purines and pterins, and aldehydes. Deficiency of the enzyme, an autosomal recessive trait, causes xanthinuria.

Heterocyclic compounds in which an oxygen is attached to a cyclic nitrogen.

The span of viability of a cell characterized by the capacity to perform certain functions such as metabolism, growth, reproduction, some form of responsiveness, and adaptability.

The termination of the cell's ability to carry out vital functions such as metabolism, growth, reproduction, responsiveness, and adaptability.

Highly reactive molecules with an unsatisfied electron valence pair. Free radicals are produced in both normal and pathological processes. They are proven or suspected agents of tissue damage in a wide variety of circumstances including radiation, damage from environment chemicals, and aging. Natural and pharmacological prevention of free radical damage is being actively investigated.

The univalent radical OH. Hydroxyl radical is a potent oxidizing agent.

A free radical gas produced endogenously by a variety of mammalian cells, synthesized from ARGININE by NITRIC OXIDE SYNTHASE. Nitric oxide is one of the ENDOTHELIUM-DEPENDENT RELAXING FACTORS released by the vascular endothelium and mediates VASODILATION. It also inhibits platelet aggregation, induces disaggregation of aggregated platelets, and inhibits platelet adhesion to the vascular endothelium. Nitric oxide activates cytosolic GUANYLATE CYCLASE and thus elevates intracellular levels of CYCLIC GMP.

Conversion of an inactive form of an enzyme to one possessing metabolic activity. It includes 1, activation by ions (activators); 2, activation by cofactors (coenzymes); and 3, conversion of an enzyme precursor (proenzyme or zymogen) to an active enzyme.

A cell line derived from cultured tumor cells.

Injuries to DNA that introduce deviations from its normal, intact structure and which may, if left unrepaired, result in a MUTATION or a block of DNA REPLICATION. These deviations may be caused by physical or chemical agents and occur by natural or unnatural, introduced circumstances. They include the introduction of illegitimate bases during replication or by deamination or other modification of bases; the loss of a base from the DNA backbone leaving an abasic site; single-strand breaks; double strand breaks; and intrastrand (PYRIMIDINE DIMERS) or interstrand crosslinking. Damage can often be repaired (DNA REPAIR). If the damage is extensive, it can induce APOPTOSIS.

An enzyme catalyzing the oxidation of 2 moles of glutathione in the presence of hydrogen peroxide to yield oxidized glutathione and water. EC 1.11.1.9.

Compounds or agents that combine with an enzyme in such a manner as to prevent the normal substrate-enzyme combination and the catalytic reaction.

The relationship between the dose of an administered drug and the response of the organism to the drug.

A botanical insecticide that is an inhibitor of mitochondrial electron transport.

A strain of albino rat used widely for experimental purposes because of its calmness and ease of handling. It was developed by the Sprague-Dawley Animal Company.

Established cell cultures that have the potential to propagate indefinitely.

A six carbon compound related to glucose. It is found naturally in citrus fruits and many vegetables. Ascorbic acid is an essential nutrient in human diets, and necessary to maintain connective tissue and bone. Its biologically active form, vitamin C, functions as a reducing agent and coenzyme in several metabolic pathways. Vitamin C is considered an antioxidant.

Identification of proteins or peptides that have been electrophoretically separated by blot transferring from the electrophoresis gel to strips of nitrocellulose paper, followed by labeling with antibody probes.

A colorimetric reagent for iron, manganese, titanium, molybdenum, and complexes of zirconium. (From Merck Index, 11th ed)

Techniques used for determining the values of photometric parameters of light resulting from LUMINESCENCE.

A large increase in oxygen uptake by neutrophils and most types of tissue macrophages through activation of an NADPH-cytochrome b-dependent oxidase that reduces oxygen to a superoxide. Individuals with an inherited defect in which the oxidase that reduces oxygen to superoxide is decreased or absent (GRANULOMATOUS DISEASE, CHRONIC) often die as a result of recurrent bacterial infections.

Cytochromes of the c type that are found in eukaryotic MITOCHONDRIA. They serve as redox intermediates that accept electrons from MITOCHONDRIAL ELECTRON TRANSPORT COMPLEX III and transfer them to MITOCHONDRIAL ELECTRON TRANSPORT COMPLEX IV.

A purine base found in most body tissues and fluids, certain plants, and some urinary calculi. It is an intermediate in the degradation of adenosine monophosphate to uric acid, being formed by oxidation of hypoxanthine. The methylated xanthine compounds caffeine, theobromine, and theophylline and their derivatives are used in medicine for their bronchodilator effects. (Dorland, 28th ed)

Elements of limited time intervals, contributing to particular results or situations.

Proteins encoded by the mitochondrial genome or proteins encoded by the nuclear genome that are imported to and resident in the MITOCHONDRIA.

A synthetic naphthoquinone without the isoprenoid side chain and biological activity, but can be converted to active vitamin K2, menaquinone, after alkylation in vivo.

Inhalation of oxygen aimed at restoring toward normal any pathophysiologic alterations of gas exchange in the cardiopulmonary system, as by the use of a respirator, nasal catheter, tent, chamber, or mask. (From Dorland, 27th ed & Stedman, 25th ed)

The mitochondria of the myocardium.

Relatively complete absence of oxygen in one or more tissues.

A short pro-domain caspase that plays an effector role in APOPTOSIS. It is activated by INITIATOR CASPASES such as CASPASE 9. Isoforms of this protein exist due to multiple alternative splicing of its MESSENGER RNA.

Theoretical representations that simulate the behavior or activity of biological processes or diseases. For disease models in living animals, DISEASE MODELS, ANIMAL is available. Biological models include the use of mathematical equations, computers, and other electronic equipment.

A flavoprotein and iron sulfur-containing oxidoreductase complex that catalyzes the conversion of UBIQUINONE to ubiquinol. In MITOCHONDRIA the complex also couples its reaction to the transport of PROTONS across the internal mitochondrial membrane. The NADH DEHYDROGENASE component of the complex can be isolated and is listed as EC 1.6.99.3.

Strains of mice in which certain GENES of their GENOMES have been disrupted, or "knocked-out". To produce knockouts, using RECOMBINANT DNA technology, the normal DNA sequence of the gene being studied is altered to prevent synthesis of a normal gene product. Cloned cells in which this DNA alteration is successful are then injected into mouse EMBRYOS to produce chimeric mice. The chimeric mice are then bred to yield a strain in which all the cells of the mouse contain the disrupted gene. Knockout mice are used as EXPERIMENTAL ANIMAL MODELS for diseases (DISEASE MODELS, ANIMAL) and to clarify the functions of the genes.

A family of ubiquitously-expressed peroxidases that play a role in the reduction of a broad spectrum of PEROXIDES like HYDROGEN PEROXIDE; LIPID PEROXIDES and peroxinitrite. They are found in a wide range of organisms, such as BACTERIA; PLANTS; and MAMMALS. The enzyme requires the presence of a thiol-containing intermediate such as THIOREDOXIN as a reducing cofactor.

Porphyrins which are combined with a metal ion. The metal is bound equally to all four nitrogen atoms of the pyrrole rings. They possess characteristic absorption spectra which can be utilized for identification or quantitative estimation of porphyrins and porphyrin-bound compounds.

A condition of decreased oxygen content at the cellular level.

A family of intracellular CYSTEINE ENDOPEPTIDASES that play a role in regulating INFLAMMATION and APOPTOSIS. They specifically cleave peptides at a CYSTEINE amino acid that follows an ASPARTIC ACID residue. Caspases are activated by proteolytic cleavage of a precursor form to yield large and small subunits that form the enzyme. Since the cleavage site within precursors matches the specificity of caspases, sequential activation of precursors by activated caspases can occur.

Granular leukocytes having a nucleus with three to five lobes connected by slender threads of chromatin, and cytoplasm containing fine inconspicuous granules and stainable by neutral dyes.

Single pavement layer of cells which line the luminal surface of the entire vascular system and regulate the transport of macromolecules and blood components.

The appearance of carbonyl groups (such as aldehyde or ketone groups) in PROTEINS as the result of several oxidative modification reactions. It is a standard marker for OXIDATIVE STRESS. Carbonylated proteins tend to be more hydrophobic and resistant to proteolysis.

A nucleoside consisting of the base guanine and the sugar deoxyribose.

The metabolic process of all living cells (animal and plant) in which oxygen is used to provide a source of energy for the cell.

The process by which ELECTRONS are transported from a reduced substrate to molecular OXYGEN. (From Bennington, Saunders Dictionary and Encyclopedia of Laboratory Medicine and Technology, 1984, p270)

A basic-leucine zipper transcription factor that was originally described as a transcriptional regulator controlling expression of the BETA-GLOBIN gene. It may regulate the expression of a wide variety of genes that play a role in protecting cells from oxidative damage.

Molecules which contain an atom or a group of atoms exhibiting an unpaired electron spin that can be detected by electron spin resonance spectroscopy and can be bonded to another molecule. (McGraw-Hill Dictionary of Chemical and Technical Terms, 4th ed)

A poisonous dipyridilium compound used as contact herbicide. Contact with concentrated solutions causes irritation of the skin, cracking and shedding of the nails, and delayed healing of cuts and wounds.

A strain of albino rat developed at the Wistar Institute that has spread widely at other institutions. This has markedly diluted the original strain.

The dialdehyde of malonic acid.

Ubiquitous, inducible, nuclear transcriptional activator that binds to enhancer elements in many different cell types and is activated by pathogenic stimuli. The NF-kappa B complex is a heterodimer composed of two DNA-binding subunits: NF-kappa B1 and relA.

The introduction of a phosphoryl group into a compound through the formation of an ester bond between the compound and a phosphorus moiety.

RNA sequences that serve as templates for protein synthesis. Bacterial mRNAs are generally primary transcripts in that they do not require post-transcriptional processing. Eukaryotic mRNA is synthesized in the nucleus and must be exported to the cytoplasm for translation. Most eukaryotic mRNAs have a sequence of polyadenylic acid at the 3' end, referred to as the poly(A) tail. The function of this tail is not known for certain, but it may play a role in the export of mature mRNA from the nucleus as well as in helping stabilize some mRNA molecules by retarding their degradation in the cytoplasm.

A positive regulatory effect on physiological processes at the molecular, cellular, or systemic level. At the molecular level, the major regulatory sites include membrane receptors, genes (GENE EXPRESSION REGULATION), mRNAs (RNA, MESSENGER), and proteins.

Splitting the DNA into shorter pieces by endonucleolytic DNA CLEAVAGE at multiple sites. It includes the internucleosomal DNA fragmentation, which along with chromatin condensation, are considered to be the hallmarks of APOPTOSIS.

A group of oxidoreductases that act on NADH or NADPH. In general, enzymes using NADH or NADPH to reduce a substrate are classified according to the reverse reaction, in which NAD+ or NADP+ is formally regarded as an acceptor. This subclass includes only those enzymes in which some other redox carrier is the acceptor. (Enzyme Nomenclature, 1992, p100) EC 1.6.

A mitogen-activated protein kinase subfamily that regulates a variety of cellular processes including CELL GROWTH PROCESSES; CELL DIFFERENTIATION; APOPTOSIS; and cellular responses to INFLAMMATION. The P38 MAP kinases are regulated by CYTOKINE RECEPTORS and can be activated in response to bacterial pathogens.

Naturally occurring or experimentally induced animal diseases with pathological processes sufficiently similar to those of human diseases. They are used as study models for human diseases.

The process by which chemical compounds provide protection to cells against harmful agents.

Sulfhydryl acylated derivative of GLYCINE.

Hydrogen-donating proteins that participates in a variety of biochemical reactions including ribonucleotide reduction and reduction of PEROXIREDOXINS. Thioredoxin is oxidized from a dithiol to a disulfide when acting as a reducing cofactor. The disulfide form is then reduced by NADPH in a reaction catalyzed by THIOREDOXIN REDUCTASE.

A direct-acting oxidative stress-inducing agent used to examine the effects of oxidant stress on Ca(2+)-dependent signal transduction in vascular endothelial cells. It is also used as a catalyst in polymerization reactions and to introduce peroxy groups into organic molecules.

A rac GTP-binding protein involved in regulating actin filaments at the plasma membrane. It controls the development of filopodia and lamellipodia in cells and thereby influences cellular motility and adhesion. It is also involved in activation of NADPH OXIDASE. This enzyme was formerly listed as EC 3.6.1.47.

Any of the processes by which nuclear, cytoplasmic, or intercellular factors influence the differential control (induction or repression) of gene action at the level of transcription or translation.

A basic element found in nearly all organized tissues. It is a member of the alkaline earth family of metals with the atomic symbol Ca, atomic number 20, and atomic weight 40. Calcium is the most abundant mineral in the body and combines with phosphorus to form calcium phosphate in the bones and teeth. It is essential for the normal functioning of nerves and muscles and plays a role in blood coagulation (as factor IV) and in many enzymatic processes.

Chemical agents that uncouple oxidation from phosphorylation in the metabolic cycle so that ATP synthesis does not occur. Included here are those IONOPHORES that disrupt electron transfer by short-circuiting the proton gradient across mitochondrial membranes.

Chelating agent and inhibitor of cellular respiration.

Small double-stranded, non-protein coding RNAs (21-31 nucleotides) involved in GENE SILENCING functions, especially RNA INTERFERENCE (RNAi). Endogenously, siRNAs are generated from dsRNAs (RNA, DOUBLE-STRANDED) by the same ribonuclease, Dicer, that generates miRNAs (MICRORNAS). The perfect match of the siRNAs' antisense strand to their target RNAs mediates RNAi by siRNA-guided RNA cleavage. siRNAs fall into different classes including trans-acting siRNA (tasiRNA), repeat-associated RNA (rasiRNA), small-scan RNA (scnRNA), and Piwi protein-interacting RNA (piRNA) and have different specific gene silencing functions.

A ubiquitous stress-responsive enzyme that catalyzes the oxidative cleavage of HEME to yield IRON; CARBON MONOXIDE; and BILIVERDIN.

Highly specialized EPITHELIAL CELLS that line the HEART; BLOOD VESSELS; and lymph vessels, forming the ENDOTHELIUM. They are polygonal in shape and joined together by TIGHT JUNCTIONS. The tight junctions allow for variable permeability to specific macromolecules that are transported across the endothelial layer.

The two lipoprotein layers in the MITOCHONDRION. The outer membrane encloses the entire mitochondrion and contains channels with TRANSPORT PROTEINS to move molecules and ions in and out of the organelle. The inner membrane folds into cristae and contains many ENZYMES important to cell METABOLISM and energy production (MITOCHONDRIAL ATP SYNTHASE).

A GLUTATHIONE dimer formed by a disulfide bond between the cysteine sulfhydryl side chains during the course of being oxidized.

Concentrated pharmaceutical preparations of plants obtained by removing active constituents with a suitable solvent, which is evaporated away, and adjusting the residue to a prescribed standard.

Low-molecular-weight end products, probably malondialdehyde, that are formed during the decomposition of lipid peroxidation products. These compounds react with thiobarbituric acid to form a fluorescent red adduct.

Natural product isolated from Streptomyces pilosus. It forms iron complexes and is used as a chelating agent, particularly in the mesylate form.

All of the processes involved in increasing CELL NUMBER including CELL DIVISION.

A family of spiro(isobenzofuran-1(3H),9'-(9H)xanthen)-3-one derivatives. These are used as dyes, as indicators for various metals, and as fluorescent labels in immunoassays.

A variation of the PCR technique in which cDNA is made from RNA via reverse transcription. The resultant cDNA is then amplified using standard PCR protocols.

A synthetic amino acid that depletes glutathione by irreversibly inhibiting gamma-glutamylcysteine synthetase. Inhibition of this enzyme is a critical step in glutathione biosynthesis. It has been shown to inhibit the proliferative response in human T-lymphocytes and inhibit macrophage activation. (J Biol Chem 1995;270(33):1945-7)

Any of the processes by which nuclear, cytoplasmic, or intercellular factors influence the differential control of gene action in enzyme synthesis.

A primary source of energy for living organisms. It is naturally occurring and is found in fruits and other parts of plants in its free state. It is used therapeutically in fluid and nutrient replacement.

Striated muscle cells found in the heart. They are derived from cardiac myoblasts (MYOBLASTS, CARDIAC).

Any detectable and heritable change in the genetic material that causes a change in the GENOTYPE and which is transmitted to daughter cells and to succeeding generations.

Organic compounds containing a carbonyl group in the form -CHO.

An antibiotic substance produced by Streptomyces species. It inhibits mitochondrial respiration and may deplete cellular levels of ATP. Antimycin A1 has been used as a fungicide, insecticide, and miticide. (From Merck Index, 12th ed)

A potent oxidant synthesized by the cell during its normal metabolism. Peroxynitrite is formed from the reaction of two free radicals, NITRIC OXIDE and the superoxide anion (SUPEROXIDES).

The class of all enzymes catalyzing oxidoreduction reactions. The substrate that is oxidized is regarded as a hydrogen donor. The systematic name is based on donor:acceptor oxidoreductase. The recommended name will be dehydrogenase, wherever this is possible; as an alternative, reductase can be used. Oxidase is only used in cases where O2 is the acceptor. (Enzyme Nomenclature, 1992, p9)

Technique using an instrument system for making, processing, and displaying one or more measurements on individual cells obtained from a cell suspension. Cells are usually stained with one or more fluorescent dyes specific to cell components of interest, e.g., DNA, and fluorescence of each cell is measured as it rapidly transverses the excitation beam (laser or mercury arc lamp). Fluorescence provides a quantitative measure of various biochemical and biophysical properties of the cell, as well as a basis for cell sorting. Other measurable optical parameters include light absorption and light scattering, the latter being applicable to the measurement of cell size, shape, density, granularity, and stain uptake.

The segregation and degradation of damaged or unwanted cytoplasmic constituents by autophagic vacuoles (cytolysosomes) composed of LYSOSOMES containing cellular components in the process of digestion; it plays an important role in BIOLOGICAL METAMORPHOSIS of amphibians, in the removal of bone by osteoclasts, and in the degradation of normal cell components in nutritional deficiency states.

A non-selective post-emergence, translocated herbicide. According to the Seventh Annual Report on Carcinogens (PB95-109781, 1994) this substance may reasonably be anticipated to be a carcinogen. (From Merck Index, 12th ed) It is an irreversible inhibitor of CATALASE, and thus impairs activity of peroxisomes.

Adverse functional, metabolic, or structural changes in ischemic tissues resulting from the restoration of blood flow to the tissue (REPERFUSION), including swelling; HEMORRHAGE; NECROSIS; and damage from FREE RADICALS. The most common instance is MYOCARDIAL REPERFUSION INJURY.

Catalyzes the oxidation of GLUTATHIONE to GLUTATHIONE DISULFIDE in the presence of NADP+. Deficiency in the enzyme is associated with HEMOLYTIC ANEMIA. Formerly listed as EC 1.6.4.2.

A superfamily of PROTEIN-SERINE-THREONINE KINASES that are activated by diverse stimuli via protein kinase cascades. They are the final components of the cascades, activated by phosphorylation by MITOGEN-ACTIVATED PROTEIN KINASE KINASES, which in turn are activated by mitogen-activated protein kinase kinase kinases (MAP KINASE KINASE KINASES).

Hypoxia-inducible factor 1, alpha subunit is a basic helix-loop-helix transcription factor that is regulated by OXYGEN availability and is targeted for degradation by VHL TUMOR SUPPRESSOR PROTEIN.

A metallic element with atomic symbol Fe, atomic number 26, and atomic weight 55.85. It is an essential constituent of HEMOGLOBINS; CYTOCHROMES; and IRON-BINDING PROTEINS. It plays a role in cellular redox reactions and in the transport of OXYGEN.

A flavoprotein oxidase complex that contains iron-sulfur centers. It catalyzes the oxidation of SUCCINATE to fumarate and couples the reaction to the reduction of UBIQUINONE to ubiquinol.

A technique applicable to the wide variety of substances which exhibit paramagnetism because of the magnetic moments of unpaired electrons. The spectra are useful for detection and identification, for determination of electron structure, for study of interactions between molecules, and for measurement of nuclear spins and moments. (From McGraw-Hill Encyclopedia of Science and Technology, 7th edition) Electron nuclear double resonance (ENDOR) spectroscopy is a variant of the technique which can give enhanced resolution. Electron spin resonance analysis can now be used in vivo, including imaging applications such as MAGNETIC RESONANCE IMAGING.

An abnormal increase in the amount of oxygen in the tissues and organs.

A complex of enzymes and PROTON PUMPS located on the inner membrane of the MITOCHONDRIA and in bacterial membranes. The protein complex provides energy in the form of an electrochemical gradient, which may be used by either MITOCHONDRIAL PROTON-TRANSLOCATING ATPASES or BACTERIAL PROTON-TRANSLOCATING ATPASES.

Double-stranded DNA of MITOCHONDRIA. In eukaryotes, the mitochondrial GENOME is circular and codes for ribosomal RNAs, transfer RNAs, and about 10 proteins.

A negative regulatory effect on physiological processes at the molecular, cellular, or systemic level. At the molecular level, the major regulatory sites include membrane receptors, genes (GENE EXPRESSION REGULATION), mRNAs (RNA, MESSENGER), and proteins.

A group of compounds that contain a bivalent O-O group, i.e., the oxygen atoms are univalent. They can either be inorganic or organic in nature. Such compounds release atomic (nascent) oxygen readily. Thus they are strong oxidizing agents and fire hazards when in contact with combustible materials, especially under high-temperature conditions. The chief industrial uses of peroxides are as oxidizing agents, bleaching agents, and initiators of polymerization. (From Hawley's Condensed Chemical Dictionary, 11th ed)

5-Amino-2,3-dihydro-1,4-phthalazinedione. Substance that emits light on oxidation. It is used in chemical determinations.

Compounds containing the -SH radical.

The pathological process occurring in cells that are dying from irreparable injuries. It is caused by the progressive, uncontrolled action of degradative ENZYMES, leading to MITOCHONDRIAL SWELLING, nuclear flocculation, and cell lysis. It is distinct it from APOPTOSIS, which is a normal, regulated cellular process.

The relatively long-lived phagocytic cell of mammalian tissues that are derived from blood MONOCYTES. Main types are PERITONEAL MACROPHAGES; ALVEOLAR MACROPHAGES; HISTIOCYTES; KUPFFER CELLS of the liver; and OSTEOCLASTS. They may further differentiate within chronic inflammatory lesions to EPITHELIOID CELLS or may fuse to form FOREIGN BODY GIANT CELLS or LANGHANS GIANT CELLS. (from The Dictionary of Cell Biology, Lackie and Dow, 3rd ed.)

A subgroup of mitogen-activated protein kinases that activate TRANSCRIPTION FACTOR AP-1 via the phosphorylation of C-JUN PROTEINS. They are components of intracellular signaling pathways that regulate CELL PROLIFERATION; APOPTOSIS; and CELL DIFFERENTIATION.

Drugs that are pharmacologically inactive but when exposed to ultraviolet radiation or sunlight are converted to their active metabolite to produce a beneficial reaction affecting the diseased tissue. These compounds can be administered topically or systemically and have been used therapeutically to treat psoriasis and various types of neoplasms.

The unfavorable effect of environmental factors (stressors) on the physiological functions of an organism. Prolonged unresolved physiological stress can affect HOMEOSTASIS of the organism, and may lead to damaging or pathological conditions.

An adenine nucleotide containing three phosphate groups esterified to the sugar moiety. In addition to its crucial roles in metabolism adenosine triphosphate is a neurotransmitter.

Connective tissue cells which secrete an extracellular matrix rich in collagen and other macromolecules.

Serum glycoprotein produced by activated MACROPHAGES and other mammalian MONONUCLEAR LEUKOCYTES. It has necrotizing activity against tumor cell lines and increases ability to reject tumor transplants. Also known as TNF-alpha, it is only 30% homologous to TNF-beta (LYMPHOTOXIN), but they share TNF RECEPTORS.

A member of the Bcl-2 protein family and homologous partner of C-BCL-2 PROTO-ONCOGENE PROTEIN. It regulates the release of CYTOCHROME C and APOPTOSIS INDUCING FACTOR from the MITOCHONDRIA. Several isoforms of BCL2-associated X protein occur due to ALTERNATIVE SPLICING of the mRNA for this protein.

The gradual irreversible changes in structure and function of an organism that occur as a result of the passage of time.

Expanded structures, usually green, of vascular plants, characteristically consisting of a bladelike expansion attached to a stem, and functioning as the principal organ of photosynthesis and transpiration. (American Heritage Dictionary, 2d ed)

A multisubunit enzyme complex that contains CYTOCHROME B GROUP; CYTOCHROME C1; and iron-sulfur centers. It catalyzes the oxidation of ubiquinol to UBIQUINONE, and transfers the electrons to CYTOCHROME C. In MITOCHONDRIA the redox reaction is coupled to the transport of PROTONS across the inner mitochondrial membrane.

A plant genus of the family BRASSICACEAE that contains ARABIDOPSIS PROTEINS and MADS DOMAIN PROTEINS. The species A. thaliana is used for experiments in classical plant genetics as well as molecular genetic studies in plant physiology, biochemistry, and development.

The nonstriated involuntary muscle tissue of blood vessels.

The phenotypic manifestation of a gene or genes by the processes of GENETIC TRANSCRIPTION and GENETIC TRANSLATION.

A hemeprotein from leukocytes. Deficiency of this enzyme leads to a hereditary disorder coupled with disseminated moniliasis. It catalyzes the conversion of a donor and peroxide to an oxidized donor and water. EC 1.11.1.7.

The muscle tissue of the HEART. It is composed of striated, involuntary muscle cells (MYOCYTES, CARDIAC) connected to form the contractile pump to generate blood flow.

A gene silencing phenomenon whereby specific dsRNAs (RNA, DOUBLE-STRANDED) trigger the degradation of homologous mRNA (RNA, MESSENGER). The specific dsRNAs are processed into SMALL INTERFERING RNA (siRNA) which serves as a guide for cleavage of the homologous mRNA in the RNA-INDUCED SILENCING COMPLEX. DNA METHYLATION may also be triggered during this process.

Benzopyrans saturated in the 2 and 3 positions.

Nicotinamide adenine dinucleotide phosphate. A coenzyme composed of ribosylnicotinamide 5'-phosphate (NMN) coupled by pyrophosphate linkage to the 5'-phosphate adenosine 2',5'-bisphosphate. It serves as an electron carrier in a number of reactions, being alternately oxidized (NADP+) and reduced (NADPH). (Dorland, 27th ed)

The decrease in the cell's ability to proliferate with the passing of time. Each cell is programmed for a certain number of cell divisions and at the end of that time proliferation halts. The cell enters a quiescent state after which it experiences CELL DEATH via the process of APOPTOSIS.

Cells that line the inner and outer surfaces of the body by forming cellular layers (EPITHELIUM) or masses. Epithelial cells lining the SKIN; the MOUTH; the NOSE; and the ANAL CANAL derive from ectoderm; those lining the RESPIRATORY SYSTEM and the DIGESTIVE SYSTEM derive from endoderm; others (CARDIOVASCULAR SYSTEM and LYMPHATIC SYSTEM) derive from mesoderm. Epithelial cells can be classified mainly by cell shape and function into squamous, glandular and transitional epithelial cells.

A mitogen-activated protein kinase subfamily that is widely expressed and plays a role in regulation of MEIOSIS; MITOSIS; and post mitotic functions in differentiated cells. The extracellular signal regulated MAP kinases are regulated by a broad variety of CELL SURFACE RECEPTORS and can be activated by certain CARCINOGENS.

Proteins involved in the transport of specific substances across the membranes of the MITOCHONDRIA.

Membrane proteins encoded by the BCL-2 GENES and serving as potent inhibitors of cell death by APOPTOSIS. The proteins are found on mitochondrial, microsomal, and NUCLEAR MEMBRANE sites within many cell types. Overexpression of bcl-2 proteins, due to a translocation of the gene, is associated with follicular lymphoma.

Any of the processes by which nuclear, cytoplasmic, or intercellular factors influence the differential control of gene action in plants.

Naphthalene rings which contain two ketone moieties in any position. They can be substituted in any position except at the ketone groups.

Either of the pair of organs occupying the cavity of the thorax that effect the aeration of the blood.

An NADPH-dependent enzyme that catalyzes the conversion of L-ARGININE and OXYGEN to produce CITRULLINE and NITRIC OXIDE.

The area within CELLS.

A promyelocytic cell line derived from a patient with ACUTE PROMYELOCYTIC LEUKEMIA. HL-60 cells lack specific markers for LYMPHOID CELLS but express surface receptors for FC FRAGMENTS and COMPLEMENT SYSTEM PROTEINS. They also exhibit phagocytic activity and responsiveness to chemotactic stimuli. (From Hay et al., American Type Culture Collection, 7th ed, pp127-8)

Peroxidases that utilize ASCORBIC ACID as an electron donor to reduce HYDROGEN PEROXIDE to WATER. The reaction results in the production of monodehydroascorbic acid and DEHYDROASCORBIC ACID.

Stable oxygen atoms that have the same atomic number as the element oxygen, but differ in atomic weight. O-17 and 18 are stable oxygen isotopes.

Substances that inhibit or prevent the proliferation of NEOPLASMS.

An octapeptide that is a potent but labile vasoconstrictor. It is produced from angiotensin I after the removal of two amino acids at the C-terminal by ANGIOTENSIN CONVERTING ENZYME. The amino acid in position 5 varies in different species. To block VASOCONSTRICTION and HYPERTENSION effect of angiotensin II, patients are often treated with ACE INHIBITORS or with ANGIOTENSIN II TYPE 1 RECEPTOR BLOCKERS.

A pathological process characterized by injury or destruction of tissues caused by a variety of cytologic and chemical reactions. It is usually manifested by typical signs of pain, heat, redness, swelling, and loss of function.

A CALCIUM-dependent, constitutively-expressed form of nitric oxide synthase found primarily in ENDOTHELIAL CELLS.

A lipid-soluble benzoquinone which is involved in ELECTRON TRANSPORT in mitochondrial preparations. The compound occurs in the majority of aerobic organisms, from bacteria to higher plants and animals.

A generic descriptor for all TOCOPHEROLS and TOCOTRIENOLS that exhibit ALPHA-TOCOPHEROL activity. By virtue of the phenolic hydrogen on the 2H-1-benzopyran-6-ol nucleus, these compounds exhibit varying degree of antioxidant activity, depending on the site and number of methyl groups and the type of ISOPRENOIDS.

A light microscopic technique in which only a small spot is illuminated and observed at a time. An image is constructed through point-by-point scanning of the field in this manner. Light sources may be conventional or laser, and fluorescence or transmitted observations are possible.

Peroxides produced in the presence of a free radical by the oxidation of unsaturated fatty acids in the cell in the presence of molecular oxygen. The formation of lipid peroxides results in the destruction of the original lipid leading to the loss of integrity of the membranes. They therefore cause a variety of toxic effects in vivo and their formation is considered a pathological process in biological systems. Their formation can be inhibited by antioxidants, such as vitamin E, structural separation or low oxygen tension.

The therapeutic intermittent administration of oxygen in a chamber at greater than sea-level atmospheric pressures (three atmospheres). It is considered effective treatment for air and gas embolisms, smoke inhalation, acute carbon monoxide poisoning, caisson disease, clostridial gangrene, etc. (From Segen, Dictionary of Modern Medicine, 1992). The list of treatment modalities includes stroke.

A photographic fixative used also in the manufacture of resins. According to the Fourth Annual Report on Carcinogens (NTP 85-002, 1985), this substance may reasonably be anticipated to be a carcinogen (Merck Index, 9th ed). Many of its derivatives are ANTITHYROID AGENTS and/or FREE RADICAL SCAVENGERS.

The process in which the neutrophil is stimulated by diverse substances, resulting in degranulation and/or generation of reactive oxygen products, and culminating in the destruction of invading pathogens. The stimulatory substances, including opsonized particles, immune complexes, and chemotactic factors, bind to specific cell-surface receptors on the neutrophil.

A protein-serine-threonine kinase that is activated by PHOSPHORYLATION in response to GROWTH FACTORS or INSULIN. It plays a major role in cell metabolism, growth, and survival as a core component of SIGNAL TRANSDUCTION. Three isoforms have been described in mammalian cells.

Organic compounds which contain selenium as an integral part of the molecule.

Electron transfer through the cytochrome system liberating free energy which is transformed into high-energy phosphate bonds.

That portion of the electromagnetic spectrum immediately below the visible range and extending into the x-ray frequencies. The longer wavelengths (near-UV or biotic or vital rays) are necessary for the endogenous synthesis of vitamin D and are also called antirachitic rays; the shorter, ionizing wavelengths (far-UV or abiotic or extravital rays) are viricidal, bactericidal, mutagenic, and carcinogenic and are used as disinfectants.

Intracellular fluid from the cytoplasm after removal of ORGANELLES and other insoluble cytoplasmic components.

The voltage differences across a membrane. For cellular membranes they are computed by subtracting the voltage measured outside the membrane from the voltage measured inside the membrane. They result from differences of inside versus outside concentration of potassium, sodium, chloride, and other ions across cells' or ORGANELLES membranes. For excitable cells, the resting membrane potentials range between -30 and -100 millivolts. Physical, chemical, or electrical stimuli can make a membrane potential more negative (hyperpolarization), or less negative (depolarization).

A tetrameric enzyme that, along with the coenzyme NAD+, catalyzes the interconversion of LACTATE and PYRUVATE. In vertebrates, genes for three different subunits (LDH-A, LDH-B and LDH-C) exist.

The basic cellular units of nervous tissue. Each neuron consists of a body, an axon, and dendrites. Their purpose is to receive, conduct, and transmit impulses in the NERVOUS SYSTEM.

Inorganic oxides that contain nitrogen.

Microscopy of specimens stained with fluorescent dye (usually fluorescein isothiocyanate) or of naturally fluorescent materials, which emit light when exposed to ultraviolet or blue light. Immunofluorescence microscopy utilizes antibodies that are labeled with fluorescent dye.

An intracellular signaling system involving the MAP kinase cascades (three-membered protein kinase cascades). Various upstream activators, which act in response to extracellular stimuli, trigger the cascades by activating the first member of a cascade, MAP KINASE KINASE KINASES; (MAPKKKs). Activated MAPKKKs phosphorylate MITOGEN-ACTIVATED PROTEIN KINASE KINASES which in turn phosphorylate the MITOGEN-ACTIVATED PROTEIN KINASES; (MAPKs). The MAPKs then act on various downstream targets to affect gene expression. In mammals, there are several distinct MAP kinase pathways including the ERK (extracellular signal-regulated kinase) pathway, the SAPK/JNK (stress-activated protein kinase/c-jun kinase) pathway, and the p38 kinase pathway. There is some sharing of components among the pathways depending on which stimulus originates activation of the cascade.

The processes whereby the internal environment of an organism tends to remain balanced and stable.

A genotoxicological technique for measuring DNA damage in an individual cell using single-cell gel electrophoresis. Cell DNA fragments assume a "comet with tail" formation on electrophoresis and are detected with an image analysis system. Alkaline assay conditions facilitate sensitive detection of single-strand damage.

An oxyacid of chlorine (HClO) containing monovalent chlorine that acts as an oxidizing or reducing agent.

Glycoproteins found on the membrane or surface of cells.

The rate dynamics in chemical or physical systems.

That portion of the electromagnetic spectrum in the visible, ultraviolet, and infrared range.

Enzymes that catalyze the transfer of multiple ADP-RIBOSE groups from nicotinamide-adenine dinucleotide (NAD) onto protein targets, thus building up a linear or branched homopolymer of repeating ADP-ribose units i.e., POLY ADENOSINE DIPHOSPHATE RIBOSE.

The main trunk of the systemic arteries.

Carbamates in which the -CO- group has been replaced by a -CS- group.

A trypanocidal agent and possible antiviral agent that is widely used in experimental cell biology and biochemistry. Ethidium has several experimentally useful properties including binding to nucleic acids, noncompetitive inhibition of nicotinic acetylcholine receptors, and fluorescence among others. It is most commonly used as the bromide.

The chemical reactions involved in the production and utilization of various forms of energy in cells.

A peroxiredoxin that is a cytosolic bifunctional enzyme. It functions as a peroxiredoxin via a single redox-active cysteine and also contains a Ca2+-independent acidic phospholipase A2 activity.

Descriptions of specific amino acid, carbohydrate, or nucleotide sequences which have appeared in the published literature and/or are deposited in and maintained by databanks such as GENBANK, European Molecular Biology Laboratory (EMBL), National Biomedical Research Foundation (NBRF), or other sequence repositories.

A technique for detecting short-lived reactive FREE RADICALS in biological systems by providing a nitrone or nitrose compound for an addition reaction to occur which produces an ELECTRON SPIN RESONANCE SPECTROSCOPY-detectable aminoxyl radical. In spin trapping, the compound trapping the radical is called the spin trap and the addition product of the radical is identified as the spin adduct. (Free Rad Res Comm 1990;9(3-6):163)

A mixed function oxidase enzyme which during hemoglobin catabolism catalyzes the degradation of heme to ferrous iron, carbon monoxide and biliverdin in the presence of molecular oxygen and reduced NADPH. The enzyme is induced by metals, particularly cobalt. EC 1.14.99.3.

Binary compounds of oxygen containing the anion O(2-). The anion combines with metals to form alkaline oxides and non-metals to form acidic oxides.

Therapy using oral or topical photosensitizing agents with subsequent exposure to light.

Laboratory mice that have been produced from a genetically manipulated EGG or EMBRYO, MAMMALIAN.

Reactive oxygen intermediate-dependent NF-kappaB activation by interleukin-1beta requires 5-lipoxygenase or NADPH oxidase activity. (1/16336)

We previously reported that the role of reactive oxygen intermediates (ROIs) in NF-kappaB activation by proinflammatory cytokines was cell specific. However, the sources for ROIs in various cell types are yet to be determined and might include 5-lipoxygenase (5-LOX) and NADPH oxidase. 5-LOX and 5-LOX activating protein (FLAP) are coexpressed in lymphoid cells but not in monocytic or epithelial cells. Stimulation of lymphoid cells with interleukin-1beta (IL-1beta) led to ROI production and NF-kappaB activation, which could both be blocked by antioxidants or FLAP inhibitors, confirming that 5-LOX was the source of ROIs and was required for NF-kappaB activation in these cells. IL-1beta stimulation of epithelial cells did not generate any ROIs and NF-kappaB induction was not influenced by 5-LOX inhibitors. However, reintroduction of a functional 5-LOX system in these cells allowed ROI production and 5-LOX-dependent NF-kappaB activation. In monocytic cells, IL-1beta treatment led to a production of ROIs which is independent of the 5-LOX enzyme but requires the NADPH oxidase activity. This pathway involves the Rac1 and Cdc42 GTPases, two enzymes which are not required for NF-kappaB activation by IL-1beta in epithelial cells. In conclusion, three different cell-specific pathways lead to NF-kappaB activation by IL-1beta: a pathway dependent on ROI production by 5-LOX in lymphoid cells, an ROI- and 5-LOX-independent pathway in epithelial cells, and a pathway requiring ROI production by NADPH oxidase in monocytic cells. (+info)

Hyperoxia induces the neuronal differentiated phenotype of PC12 cells via a sustained activity of mitogen-activated protein kinase induced by Bcl-2. (2/16336)

We previously reported that rat pheochromocytoma PC12 cells express the neuronal differentiated phenotype under hyperoxia through the production of reactive oxygen species (ROS). In the present study, we found that in this phenotype, Bcl-2, an apoptosis inhibitor, affects mitogen-activated protein (MAP)-kinase activity, which is known as a key enzyme of the signal-transduction cascade for differentiation. When PC12 cells were cultured under hyperoxia, a rapid increase in MAP-kinase activity, including that of both p42 and p44, was observed. Although the activity level then decreased quickly, activity higher than the control level was observed for 48 h. PD98059, an inhibitor of MAP kinase, suppressed the hyperoxia-induced neurite extensions, suggesting the involvement of MAP-kinase activity in the mechanism of differentiation induced by ROS. An elevation of Bcl-2 expression was observed after culturing PC12 cells for 24 h under hyperoxia. This Bcl-2 elevation was not affected by treatment with PD98059, suggesting that it did not directly induce neurite extension under hyperoxia. However, the blockade of the Bcl-2 elevation by an antisense oligonucleotide inhibited the sustained MAP-kinase activity and neurite extensions under hyperoxia. Further, in PC12 cells highly expressing Bcl-2, the sustained MAP-kinase activity and neurite extensions under hyperoxia were enhanced. These results suggested that MAP kinase is activated through the production of ROS, and the subsequent elevation of Bcl-2 expression sustains the MAP-kinase activity, resulting in the induction of the neuronal-differentiation phenotype of PC12 cells under hyperoxia. (+info)

The Pseudomonas aeruginosa secretory product pyocyanin inactivates alpha1 protease inhibitor: implications for the pathogenesis of cystic fibrosis lung disease. (3/16336)

Alpha1 Protease inhibitor (alpha1PI) modulates serine protease activity in the lung. Reactive oxygen species inactivate alpha1PI, and this process has been implicated in the pathogenesis of a variety of forms of lung injury. An imbalance of protease-antiprotease activity is also detected in the airways of patients with cystic fibrosis-associated lung disease who are infected with Pseudomonas aeruginosa. P. aeruginosa secretes pyocyanin, which, through its ability to redox cycle, induces cells to generate reactive oxygen species. We tested the hypothesis that redox cycling of pyocyanin could lead to inactivation of alpha1PI. When alpha1PI was exposed to NADH and pyocyanin, a combination that results in superoxide production, alpha1PI lost its ability to form an inhibitory complex with both porcine pancreatic elastase (PPE) and trypsin. Similarly, addition of pyocyanin to cultures of human airway epithelial cells to which alpha1PI was also added resulted in a loss of the ability of alpha1PI to form a complex with PPE or trypsin. Neither superoxide dismutase, catalase, nor dimethylthiourea nor depletion of the media of O2 to prevent formation of reactive oxygen species blocked pyocyanin-mediated inactivation of alpha1PI. These data raise the possibility that a direct interaction between reduced pyocyanin and alpha1PI is involved in the process. Consistent with this possibility, pretreatment of alpha1PI with the reducing agent beta-mercaptoethanol also inhibited binding of trypsin to alpha1PI. These data suggest that pyocyanin could contribute to lung injury in the P. aeruginosa-infected airway of cystic fibrosis patients by decreasing the ability of alpha1PI to control the local activity of serine proteases. (+info)

Inflammatory cell-mediated tumour progression and minisatellite mutation correlate with the decrease of antioxidative enzymes in murine fibrosarcoma cells. (4/16336)

We isolated six clones of weakly tumorigenic fibrosarcoma (QR) from the tumorigenic clone BMT-11 cl-9. The QR clones were unable to grow in normal C57BL/6 mice when injected s.c. (1x10(5) cells). However, they formed aggressive tumours upon co-implantation with a 'foreign body', i.e. a gelatin sponge, and the rate of tumour take ranged from 8% to 58% among QR clones. The enhanced tumorigenicity was due to host cell-mediated reaction to the gelatin sponge (inflammation). Immunoblot analysis and enzyme activity assay revealed a significant inverse correlation between the frequencies of tumour formation by QR clones and the levels of manganese superoxide dismutase (Mn-SOD, P<0.005) and glutathione peroxidase (GPchi, P<0.01) in the respective tumour clones. Electron spin resonance (ESR) revealed that superoxide-scavenging ability of cell lysates of the QR clone with high level of Mn-SOD was significantly higher than that with low level of the antioxidative enzyme in the presence of potassium cyanide, an inhibitor for copper-zinc superoxide dismutase (CuZn-SOD) (P<0.001). Minisatellite mutation (MSM) induced by the inflammatory cells in tumour cells were investigated by DNA fingerprint analysis after QR clones had been co-cultured with gelatin-sponge-reactive cells. The MSM rate was significantly higher in the subclones with low levels of Mn-SOD and GPchi (P<0.05) than in the subclones with high levels of both enzymes. The MSM of the subclones with low levels of both enzymes was inhibited in the presence of mannitol, a hydroxyl radical scavenger. The content of 8-hydroxydeoxyguanosine (8-OHdG) by which the cellular DNA damage caused by active oxygen species can be assessed was significantly low in the tumours arising from the QR clone with high levels of Mn-SOD and GPchi even if the clone had been co-implanted with gelatin sponge, compared with the arising tumour from the QR clone with low levels of those antioxidative enzymes (P<0.001). In contrast, CuZn-SOD and catalase levels in the six QR clones did not have any correlation with tumour progression parameters. These results suggest that tumour progression is accelerated by inflammation-induced active oxygen species particularly accompanied with declined levels of intracellular antioxidative enzymes in tumour cells. (+info)

Reactive oxygen species play an important role in the activation of heat shock factor 1 in ischemic-reperfused heart. (5/16336)

BACKGROUND: The myocardial protective role of heat shock protein (HSP) has been demonstrated. Recently, we reported that ischemia/reperfusion induced a significant activation of heat shock factor (HSF) 1 and an accumulation of mRNA for HSP70 and HSP90. We examined the role of reactive oxygen species (ROSs) in the induction of stress response in the ischemic-reperfused heart. METHODS AND RESULTS: Rat hearts were isolated and perfused with Krebs-Henseleit buffer by the Langendorff method. Whole-cell extracts were prepared for gel mobility shift assay using oligonucleotides containing the heat shock element. Induction of mRNA for HSP70 and HSP90 was examined by Northern blot analysis. Repetitive ischemia/reperfusion, which causes recurrent bursts of free radical generation, resulted in burst activation of HSF1, and this burst activation was significantly reduced with either allopurinol 1 mmol/L (an inhibitor of xanthine oxidase) or catalase 2x10(5) U/L (a scavenger of H2O2). Significant activation of HSF1 was observed on perfusion with buffer containing H2O2 150 micromol/L or xanthine 1 mmol/L plus xanthine oxidase 5 U/L. The accumulation of mRNA for HSP70 or HSP90 after repetitive ischemia/reperfusion was reduced with either allopurinol or catalase. CONCLUSIONS: Our findings demonstrate that ROSs play an important role in the activation of HSF1 and the accumulation of mRNA for HSP70 and HSP90 in the ischemic-reperfused heart. (+info)

Methemoglobin formation by hydroxylamine metabolites of sulfamethoxazole and dapsone: implications for differences in adverse drug reactions. (6/16336)

Differences in the incidence of adverse drug reactions to trimethoprim-sulfamethoxazole and dapsone may result from differences in the formation, disposition, toxicity, and/or detoxification of their hydroxylamine metabolites. In this study, we examine whether differences in the biochemical processing of sulfamethoxazole hydroxylamine (SMX-NOH) and dapsone hydroxylamine (DDS-NOH) by erythrocytes [red blood cells (RBCs)] contribute to this differential incidence. The methemoglobin (MetHgb)-forming capacity of both metabolites was compared after a 60-min incubation with washed RBCs from four healthy human volunteers. DDS-NOH was significantly more potent (P =.004) but equally efficacious with SMX-NOH in its ability to form MetHgb. The elimination of potential differences in disposition by lysing RBCs did not change the MetHgb-forming potency of either hydroxylamine. At pharmacologically relevant concentrations, greater reduction to the parent amine occurred with DDS-NOH. Maintenance of MetHgb-forming potency was dependent on recycling with glutathione, but no difference in cycling efficiency was observed between DDS-NOH and SMX-NOH. In contrast, the pharmacodynamics of hydroxylamine-induced MetHgb formation were not changed by pretreatment with the glucose 6-phosphate dehydrogenase inhibitor epiandrosterone or by compounds that alter normal antioxidant enzyme activity. Methylene blue, which stimulates NADPH-dependent MetHgb reductase activity, decreased MetHgb levels but did not alter the differential potency of these hydroxylamines. DDS-NOH was also significantly more potent when incubated with purified human hemoglobin A0. Collectively, these data suggest that the inherently greater reactivity of DDS-NOH with hemoglobin, the greater conversion of DDS-NOH to its parent amine, and potential differences in disposition of hydroxylamine metabolites may contribute to the preferential development of dapsone-induced hemotoxicity and sulfamethoxazole-induced hypersensitivity reactions. (+info)

Mechanisms and mediators in coal dust induced toxicity: a review. (7/16336)

Chronic inhalation of coal dust can cause several lung disorders, including simple coal workers pneumoconiosis (CWP), progressive massive fibrosis (PMF), chronic bronchitis, lung function loss, and emphysema. This review focuses on the cellular actions and interactions of key inflammatory cells and target cells in coal dust toxicity and related lung disorders, i.e. macrophages and neutrophils, epithelial cells, and fibroblasts. Factors released from or affecting these cells are outlined in separate sections, i.e. (1) reactive oxygen species (ROS) and related antioxidant protection mechanisms, and (2) cytokines, growth factors and related proteins. Furthermore, (3) components of the extracellular matrix (ECM), including the modifying role of ROS, cytokines, proteases and antiproteases are discussed in relation to tissue damage and remodelling in the respiratory tract. It is recognised that inhaled coal dust particles are important non-cellular and cellular sources of ROS in the lung, and may be significantly involved in the damage of lung target cells as well as important macromolecules including alpha-1-antitrypsin and DNA. In vitro and in vivo studies with coal dusts showed the up-regulation of important leukocyte recruiting factors, e.g. Leukotriene-B4 (LTB4), Platelet Derived Growth Factor (PDGF), Monocyte Chemotactic Protein-1 (MCP-1), and Tumor Necrosis Factor-alpha (TNF alpha), as well as the neutrophil adhesion factor Intercellular Adhesion Molecule-1 (ICAM-1). Coal dust particles are also known to stimulate the (macrophage) production of various factors with potential capacity to modulate lung cells and/or extracellular matrix, including O2-., H2O2, and NO, fibroblast chemoattractants (e.g. Transforming Growth Factor-beta (TGF beta), PDGF, and fibronectin) and a number of factors that have been shown to stimulate and/or inhibit fibroblast growth or collagen production such as (TNF alpha, TGF beta, PDGF, Insulin Like Growth Factor, and Prostaglandin-E2). Further studies are needed to clarify the in vivo kinetics and relative impact of these factors. (+info)

1,25-Dihydroxyvitamin D3 enhances the susceptibility of breast cancer cells to doxorubicin-induced oxidative damage. (8/16336)

1,25-Dihydroxyvitamin D3 (1,25(OH)2D3), the hormonal form of vitamin D, has anticancer activity in vivo and in vitro. Doxorubicin exerts its cytotoxic effect on tumor cells mainly by two mechanisms: (a) generation of reactive oxygen species (ROS); and (b) inhibition of topoisomerase II. We studied the combined cytotoxic action of 1,25(OH)2D3 and doxorubicin on MCF-7 breast cancer cells. Pretreatement with 1,25(OH)2D3 resulted in enhanced cytotoxicity of doxorubicin. The average enhancing effect after a 72-h pretreatment with 1,25(OH)2D3 (10 nM) followed by a 24-h treatment with 1 microg/ml doxorubicin was 74+/-9% (mean +/- SE). Under these experimental conditions, 1,25(OH)2D3 on its own did not affect cell number or viability. 1,25(OH)2D3 also enhanced the cytotoxic activity of another ROS generating quinone, menadione, but did not affect cytotoxicity induced by the topoisomerase inhibitor etoposide. The antioxidant N-acetylcysteine slightly reduced the cytotoxic activity of doxorubicin but had a marked protective effect against the combined action of 1,25(OH)2D3 and doxorubicin. These results indicate that ROS are involved in the interaction between 1,25(OH)2D3 and doxorubicin. 1,25(OH)2D3 also increased doxorubicin cytotoxicity in primary cultures of rat cardiomyocytes. Treatment of MCF-7 cells with 1,25(OH)2D3 alone markedly reduced the activity, protein, and mRNA levels of the cytoplasmic antioxidant enzyme Cu/Zn superoxide dismutase, which indicated that the hormone inhibits its biosynthesis. This reduction in the antioxidant capacity of the cells could account for the synergistic interaction between 1,25(OH)2D3 and doxorubicin and may also suggest increased efficacy of 1,25(OH)2D3 or its analogues in combination with other ROS-generating anticancer therapeutic modalities. (+info)

There are different types of anoxia, including:

1. Cerebral anoxia: This occurs when the brain does not receive enough oxygen, leading to cognitive impairment, confusion, and loss of consciousness.
2. Pulmonary anoxia: This occurs when the lungs do not receive enough oxygen, leading to shortness of breath, coughing, and chest pain.
3. Cardiac anoxia: This occurs when the heart does not receive enough oxygen, leading to cardiac arrest and potentially death.
4. Global anoxia: This is a complete lack of oxygen to the entire body, leading to widespread tissue damage and death.

Treatment for anoxia depends on the underlying cause and the severity of the condition. In some cases, hospitalization may be necessary to provide oxygen therapy, pain management, and other supportive care. In severe cases, anoxia can lead to long-term disability or death.

Prevention of anoxia is important, and this includes managing underlying medical conditions such as heart disease, diabetes, and respiratory problems. It also involves avoiding activities that can lead to oxygen deprivation, such as scuba diving or high-altitude climbing, without proper training and equipment.

In summary, anoxia is a serious medical condition that occurs when there is a lack of oxygen in the body or specific tissues or organs. It can cause cell death and tissue damage, leading to serious health complications and even death if left untreated. Early diagnosis and treatment are crucial to prevent long-term disability or death.

1) They share similarities with humans: Many animal species share similar biological and physiological characteristics with humans, making them useful for studying human diseases. For example, mice and rats are often used to study diseases such as diabetes, heart disease, and cancer because they have similar metabolic and cardiovascular systems to humans.

2) They can be genetically manipulated: Animal disease models can be genetically engineered to develop specific diseases or to model human genetic disorders. This allows researchers to study the progression of the disease and test potential treatments in a controlled environment.

3) They can be used to test drugs and therapies: Before new drugs or therapies are tested in humans, they are often first tested in animal models of disease. This allows researchers to assess the safety and efficacy of the treatment before moving on to human clinical trials.

4) They can provide insights into disease mechanisms: Studying disease models in animals can provide valuable insights into the underlying mechanisms of a particular disease. This information can then be used to develop new treatments or improve existing ones.

5) Reduces the need for human testing: Using animal disease models reduces the need for human testing, which can be time-consuming, expensive, and ethically challenging. However, it is important to note that animal models are not perfect substitutes for human subjects, and results obtained from animal studies may not always translate to humans.

6) They can be used to study infectious diseases: Animal disease models can be used to study infectious diseases such as HIV, TB, and malaria. These models allow researchers to understand how the disease is transmitted, how it progresses, and how it responds to treatment.

7) They can be used to study complex diseases: Animal disease models can be used to study complex diseases such as cancer, diabetes, and heart disease. These models allow researchers to understand the underlying mechanisms of the disease and test potential treatments.

8) They are cost-effective: Animal disease models are often less expensive than human clinical trials, making them a cost-effective way to conduct research.

9) They can be used to study drug delivery: Animal disease models can be used to study drug delivery and pharmacokinetics, which is important for developing new drugs and drug delivery systems.

10) They can be used to study aging: Animal disease models can be used to study the aging process and age-related diseases such as Alzheimer's and Parkinson's. This allows researchers to understand how aging contributes to disease and develop potential treatments.

Reperfusion injury can cause inflammation, cell death, and impaired function in the affected tissue or organ. The severity of reperfusion injury can vary depending on the duration and severity of the initial ischemic event, as well as the promptness and effectiveness of treatment to restore blood flow.

Reperfusion injury can be a complicating factor in various medical conditions, including:

1. Myocardial infarction (heart attack): Reperfusion injury can occur when blood flow is restored to the heart muscle after a heart attack, leading to inflammation and cell death.
2. Stroke: Reperfusion injury can occur when blood flow is restored to the brain after an ischemic stroke, leading to inflammation and damage to brain tissue.
3. Organ transplantation: Reperfusion injury can occur when a transplanted organ is subjected to ischemia during harvesting or preservation, and then reperfused with blood.
4. Peripheral arterial disease: Reperfusion injury can occur when blood flow is restored to a previously occluded peripheral artery, leading to inflammation and damage to the affected tissue.

Treatment of reperfusion injury often involves medications to reduce inflammation and oxidative stress, as well as supportive care to manage symptoms and prevent further complications. In some cases, experimental therapies such as stem cell transplantation or gene therapy may be used to promote tissue repair and regeneration.

Hyperoxia can cause damage to the body's tissues and organs, particularly the lungs and brain. In severe cases, hyperoxia can lead to respiratory failure, seizures, and even death.

There are several ways to diagnose hyperoxia, including:

1. Blood tests: These can measure the levels of oxygen in the blood.
2. Arterial blood gas (ABG) analysis: This is a test that measures the amounts of oxygen and carbon dioxide in the blood.
3. Pulse oximetry: This is a non-invasive test that measures the amount of oxygen in the blood by shining a light through the skin.

Treatment for hyperoxia depends on the underlying cause, but may include:

1. Oxygen therapy: This involves administering oxygen to the patient through a mask or nasal tubes.
2. Medications: These may be used to treat any underlying conditions that are causing hyperoxia.
3. Mechanical ventilation: In severe cases, this may be necessary to support the patient's breathing.

In summary, hyperoxia is a condition where there is too much oxygen in the body, and it can cause damage to the body's tissues and organs. Diagnosis is typically made through blood tests or other tests, and treatment may involve oxygen therapy, medications, or mechanical ventilation.

Necrosis is a type of cell death that occurs when cells are exposed to excessive stress, injury, or inflammation, leading to damage to the cell membrane and the release of cellular contents into the surrounding tissue. This can lead to the formation of gangrene, which is the death of body tissue due to lack of blood supply.

There are several types of necrosis, including:

1. Coagulative necrosis: This type of necrosis occurs when there is a lack of blood supply to the tissues, leading to the formation of a firm, white plaque on the surface of the affected area.
2. Liquefactive necrosis: This type of necrosis occurs when there is an infection or inflammation that causes the death of cells and the formation of pus.
3. Caseous necrosis: This type of necrosis occurs when there is a chronic infection, such as tuberculosis, and the affected tissue becomes soft and cheese-like.
4. Fat necrosis: This type of necrosis occurs when there is trauma to fatty tissue, leading to the formation of firm, yellowish nodules.
5. Necrotizing fasciitis: This is a severe and life-threatening form of necrosis that affects the skin and underlying tissues, often as a result of bacterial infection.

The diagnosis of necrosis is typically made through a combination of physical examination, imaging studies such as X-rays or CT scans, and laboratory tests such as biopsy. Treatment depends on the underlying cause of the necrosis and may include antibiotics, surgical debridement, or amputation in severe cases.

There are several key features of inflammation:

1. Increased blood flow: Blood vessels in the affected area dilate, allowing more blood to flow into the tissue and bringing with it immune cells, nutrients, and other signaling molecules.
2. Leukocyte migration: White blood cells, such as neutrophils and monocytes, migrate towards the site of inflammation in response to chemical signals.
3. Release of mediators: Inflammatory mediators, such as cytokines and chemokines, are released by immune cells and other cells in the affected tissue. These molecules help to coordinate the immune response and attract more immune cells to the site of inflammation.
4. Activation of immune cells: Immune cells, such as macrophages and T cells, become activated and start to phagocytose (engulf) pathogens or damaged tissue.
5. Increased heat production: Inflammation can cause an increase in metabolic activity in the affected tissue, leading to increased heat production.
6. Redness and swelling: Increased blood flow and leakiness of blood vessels can cause redness and swelling in the affected area.
7. Pain: Inflammation can cause pain through the activation of nociceptors (pain-sensing neurons) and the release of pro-inflammatory mediators.

Inflammation can be acute or chronic. Acute inflammation is a short-term response to injury or infection, which helps to resolve the issue quickly. Chronic inflammation is a long-term response that can cause ongoing damage and diseases such as arthritis, asthma, and cancer.

There are several types of inflammation, including:

1. Acute inflammation: A short-term response to injury or infection.
2. Chronic inflammation: A long-term response that can cause ongoing damage and diseases.
3. Autoimmune inflammation: An inappropriate immune response against the body's own tissues.
4. Allergic inflammation: An immune response to a harmless substance, such as pollen or dust mites.
5. Parasitic inflammation: An immune response to parasites, such as worms or fungi.
6. Bacterial inflammation: An immune response to bacteria.
7. Viral inflammation: An immune response to viruses.
8. Fungal inflammation: An immune response to fungi.

There are several ways to reduce inflammation, including:

1. Medications such as nonsteroidal anti-inflammatory drugs (NSAIDs), corticosteroids, and disease-modifying anti-rheumatic drugs (DMARDs).
2. Lifestyle changes, such as a healthy diet, regular exercise, stress management, and getting enough sleep.
3. Alternative therapies, such as acupuncture, herbal supplements, and mind-body practices.
4. Addressing underlying conditions, such as hormonal imbalances, gut health issues, and chronic infections.
5. Using anti-inflammatory compounds found in certain foods, such as omega-3 fatty acids, turmeric, and ginger.

It's important to note that chronic inflammation can lead to a range of health problems, including:

1. Arthritis
2. Diabetes
3. Heart disease
4. Cancer
5. Alzheimer's disease
6. Parkinson's disease
7. Autoimmune disorders, such as lupus and rheumatoid arthritis.

Therefore, it's important to manage inflammation effectively to prevent these complications and improve overall health and well-being.

MRI can occur in various cardiovascular conditions, such as myocardial infarction (heart attack), cardiac arrest, and cardiac surgery. The severity of MRI can range from mild to severe, depending on the extent and duration of the ischemic event.

The pathophysiology of MRI involves a complex interplay of various cellular and molecular mechanisms. During ischemia, the heart muscle cells undergo changes in energy metabolism, electrolyte balance, and cell membrane function. When blood flow is restored, these changes can lead to an influx of calcium ions into the cells, activation of enzymes, and production of reactive oxygen species (ROS), which can damage the cells and their membranes.

The clinical presentation of MRI can vary depending on the severity of the injury. Some patients may experience chest pain, shortness of breath, and fatigue. Others may have more severe symptoms, such as cardiogenic shock or ventricular arrhythmias. The diagnosis of MRI is based on a combination of clinical findings, electrocardiography (ECG), echocardiography, and cardiac biomarkers.

The treatment of MRI is focused on addressing the underlying cause of the injury and managing its symptoms. For example, in patients with myocardial infarction, thrombolysis or percutaneous coronary intervention may be used to restore blood flow to the affected area. In patients with cardiac arrest, cardiopulmonary resuscitation (CPR) and other life-saving interventions may be necessary.

Prevention of MRI is crucial in reducing its incidence and severity. This involves aggressive risk factor management, such as controlling hypertension, diabetes, and dyslipidemia, as well as smoking cessation and stress reduction. Additionally, patients with a history of MI should adhere to their medication regimen, which may include beta blockers, ACE inhibitors or ARBs, statins, and aspirin.

In conclusion, myocardial injury with ST-segment elevation (MRI) is a life-threatening condition that requires prompt recognition and treatment. While the clinical presentation can vary depending on the severity of the injury, early diagnosis and management are crucial in reducing morbidity and mortality. Prevention through aggressive risk factor management and adherence to medication regimens is also essential in preventing MRI.

Mitochondrial diseases can affect anyone, regardless of age or gender, and they can be caused by mutations in either the mitochondrial DNA (mtDNA) or the nuclear DNA (nDNA). These mutations can be inherited from one's parents or acquired during embryonic development.

Some of the most common symptoms of mitochondrial diseases include:

1. Muscle weakness and wasting
2. Seizures
3. Cognitive impairment
4. Vision loss
5. Hearing loss
6. Heart problems
7. Neurological disorders
8. Gastrointestinal issues
9. Liver and kidney dysfunction

Some examples of mitochondrial diseases include:

1. MELAS syndrome (Mitochondrial Myopathy, Encephalopathy, Lactic Acidosis, and Stroke-like episodes)
2. Kearns-Sayre syndrome (a rare progressive disorder that affects the nervous system and other organs)
3. Chronic progressive external ophthalmoplegia (CPEO), which is characterized by weakness of the extraocular muscles and vision loss
4. Mitochondrial DNA depletion syndrome, which can cause a wide range of symptoms including seizures, developmental delays, and muscle weakness.
5. Mitochondrial myopathy, encephalomyopathy, lactic acidosis, and stroke-like episodes (MELAS)
6. Leigh syndrome, which is a rare genetic disorder that affects the brain and spinal cord.
7. LHON (Leber's Hereditary Optic Neuropathy), which is a rare form of vision loss that can lead to blindness in one or both eyes.
8. Mitochondrial DNA mutation, which can cause a wide range of symptoms including seizures, developmental delays, and muscle weakness.
9. Mitochondrial myopathy, encephalomyopathy, lactic acidosis, and stroke-like episodes (MELAS)
10. Kearns-Sayre syndrome, which is a rare progressive disorder that affects the nervous system and other organs.

It's important to note that this is not an exhaustive list and there are many more mitochondrial diseases and disorders that can affect individuals. Additionally, while these diseases are rare, they can have a significant impact on the quality of life of those affected and their families.

Types of Experimental Diabetes Mellitus include:

1. Streptozotocin-induced diabetes: This type of EDM is caused by administration of streptozotocin, a chemical that damages the insulin-producing beta cells in the pancreas, leading to high blood sugar levels.
2. Alloxan-induced diabetes: This type of EDM is caused by administration of alloxan, a chemical that also damages the insulin-producing beta cells in the pancreas.
3. Pancreatectomy-induced diabetes: In this type of EDM, the pancreas is surgically removed or damaged, leading to loss of insulin production and high blood sugar levels.

Experimental Diabetes Mellitus has several applications in research, including:

1. Testing new drugs and therapies for diabetes treatment: EDM allows researchers to evaluate the effectiveness of new treatments on blood sugar control and other physiological processes.
2. Studying the pathophysiology of diabetes: By inducing EDM in animals, researchers can study the progression of diabetes and its effects on various organs and tissues.
3. Investigating the role of genetics in diabetes: Researchers can use EDM to study the effects of genetic mutations on diabetes development and progression.
4. Evaluating the efficacy of new diagnostic techniques: EDM allows researchers to test new methods for diagnosing diabetes and monitoring blood sugar levels.
5. Investigating the complications of diabetes: By inducing EDM in animals, researchers can study the development of complications such as retinopathy, nephropathy, and cardiovascular disease.

In conclusion, Experimental Diabetes Mellitus is a valuable tool for researchers studying diabetes and its complications. The technique allows for precise control over blood sugar levels and has numerous applications in testing new treatments, studying the pathophysiology of diabetes, investigating the role of genetics, evaluating new diagnostic techniques, and investigating complications.

Neoplasm refers to an abnormal growth of cells that can be benign (non-cancerous) or malignant (cancerous). Neoplasms can occur in any part of the body and can affect various organs and tissues. The term "neoplasm" is often used interchangeably with "tumor," but while all tumors are neoplasms, not all neoplasms are tumors.

Types of Neoplasms

There are many different types of neoplasms, including:

1. Carcinomas: These are malignant tumors that arise in the epithelial cells lining organs and glands. Examples include breast cancer, lung cancer, and colon cancer.
2. Sarcomas: These are malignant tumors that arise in connective tissue, such as bone, cartilage, and fat. Examples include osteosarcoma (bone cancer) and soft tissue sarcoma.
3. Lymphomas: These are cancers of the immune system, specifically affecting the lymph nodes and other lymphoid tissues. Examples include Hodgkin lymphoma and non-Hodgkin lymphoma.
4. Leukemias: These are cancers of the blood and bone marrow that affect the white blood cells. Examples include acute myeloid leukemia (AML) and chronic lymphocytic leukemia (CLL).
5. Melanomas: These are malignant tumors that arise in the pigment-producing cells called melanocytes. Examples include skin melanoma and eye melanoma.

Causes and Risk Factors of Neoplasms

The exact causes of neoplasms are not fully understood, but there are several known risk factors that can increase the likelihood of developing a neoplasm. These include:

1. Genetic predisposition: Some people may be born with genetic mutations that increase their risk of developing certain types of neoplasms.
2. Environmental factors: Exposure to certain environmental toxins, such as radiation and certain chemicals, can increase the risk of developing a neoplasm.
3. Infection: Some neoplasms are caused by viruses or bacteria. For example, human papillomavirus (HPV) is a common cause of cervical cancer.
4. Lifestyle factors: Factors such as smoking, excessive alcohol consumption, and a poor diet can increase the risk of developing certain types of neoplasms.
5. Family history: A person's risk of developing a neoplasm may be higher if they have a family history of the condition.

Signs and Symptoms of Neoplasms

The signs and symptoms of neoplasms can vary depending on the type of cancer and where it is located in the body. Some common signs and symptoms include:

1. Unusual lumps or swelling
2. Pain
3. Fatigue
4. Weight loss
5. Change in bowel or bladder habits
6. Unexplained bleeding
7. Coughing up blood
8. Hoarseness or a persistent cough
9. Changes in appetite or digestion
10. Skin changes, such as a new mole or a change in the size or color of an existing mole.

Diagnosis and Treatment of Neoplasms

The diagnosis of a neoplasm usually involves a combination of physical examination, imaging tests (such as X-rays, CT scans, or MRI scans), and biopsy. A biopsy involves removing a small sample of tissue from the suspected tumor and examining it under a microscope for cancer cells.

The treatment of neoplasms depends on the type, size, location, and stage of the cancer, as well as the patient's overall health. Some common treatments include:

1. Surgery: Removing the tumor and surrounding tissue can be an effective way to treat many types of cancer.
2. Chemotherapy: Using drugs to kill cancer cells can be effective for some types of cancer, especially if the cancer has spread to other parts of the body.
3. Radiation therapy: Using high-energy radiation to kill cancer cells can be effective for some types of cancer, especially if the cancer is located in a specific area of the body.
4. Immunotherapy: Boosting the body's immune system to fight cancer can be an effective treatment for some types of cancer.
5. Targeted therapy: Using drugs or other substances to target specific molecules on cancer cells can be an effective treatment for some types of cancer.

Prevention of Neoplasms

While it is not always possible to prevent neoplasms, there are several steps that can reduce the risk of developing cancer. These include:

1. Avoiding exposure to known carcinogens (such as tobacco smoke and radiation)
2. Maintaining a healthy diet and lifestyle
3. Getting regular exercise
4. Not smoking or using tobacco products
5. Limiting alcohol consumption
6. Getting vaccinated against certain viruses that are associated with cancer (such as human papillomavirus, or HPV)
7. Participating in screening programs for early detection of cancer (such as mammograms for breast cancer and colonoscopies for colon cancer)
8. Avoiding excessive exposure to sunlight and using protective measures such as sunscreen and hats to prevent skin cancer.

It's important to note that not all cancers can be prevented, and some may be caused by factors that are not yet understood or cannot be controlled. However, by taking these steps, individuals can reduce their risk of developing cancer and improve their overall health and well-being.

There are several types of ischemia, including:

1. Myocardial ischemia: Reduced blood flow to the heart muscle, which can lead to chest pain or a heart attack.
2. Cerebral ischemia: Reduced blood flow to the brain, which can lead to stroke or cognitive impairment.
3. Peripheral arterial ischemia: Reduced blood flow to the legs and arms.
4. Renal ischemia: Reduced blood flow to the kidneys.
5. Hepatic ischemia: Reduced blood flow to the liver.

Ischemia can be diagnosed through a variety of tests, including electrocardiograms (ECGs), stress tests, and imaging studies such as CT or MRI scans. Treatment for ischemia depends on the underlying cause and may include medications, lifestyle changes, or surgical interventions.

Oxygen toxicity Pro-oxidant Reactive nitrogen species Reactive sulfur species Reactive carbonyl species Reactive oxygen species ... "Upsides and downsides of reactive oxygen species for cancer: the roles of reactive oxygen species in tumorigenesis, prevention ... In chemistry, reactive oxygen species (ROS) are highly reactive chemicals formed from diatomic oxygen (O2). Examples of ROS ... The reduction of molecular oxygen (O2) produces superoxide (•O−2), which is the precursor to most other reactive oxygen species ...

https://en.wikipedia.org/wiki/Reactive_oxygen_species

Many algal species have been shown to not only produce reactive oxygen species under normal conditions but to increase ... The products of this subsequent reduction of molecular oxygen are what are referred to as reactive oxygen species. Thus, the ... All living cells produce reactive oxygen species (ROS) as a byproduct of metabolism. ROS are reduced oxygen intermediates that ... Reactive oxygen species in natural waters". In Christopher S. Foote (ed.). Active oxygen in chemistry. London: Blackie Acad. & ...

https://en.wikipedia.org/wiki/Reactive_oxygen_species_production_in_marine_microalgae

Therefore, NADPH prevents reactive oxygen species from accumulating and damaging cells. Excessive activation of the polyol ... Bonnefont-Rousselot D (September 2002). "Glucose and reactive oxygen species". Current Opinion in Clinical Nutrition and ... increased concentrations of reactive oxygen species, and decreased concentrations of nitric oxide and glutathione. Each of ...

https://en.wikipedia.org/wiki/Polyol_pathway

Inside mitochondria, reactive oxygen species (ROS), or free radicals, byproducts of the constant production of adenosine ... DNA damage can be subdivided into two main types: endogenous damage such as attack by reactive oxygen species produced from ... increase in reactive oxygen species (ROS). Replication stress, along with the selection for inactivating mutations in DNA ... and generation of DNA strand interruptions from reactive oxygen species, alkylation of bases (usually methylation), such as ...

https://en.wikipedia.org/wiki/DNA_repair

Indirect evidence via monitoring biomarkers such as reactive oxygen species, and reactive nitrogen species production indicates ... Production of reactive oxygen species is a particularly destructive aspect of oxidative stress. Such species include free ... This action catalyzes production of reactive radicals and reactive oxygen species. The presence of such metals in biological ... The reaction of transition metals with proteins oxidated by reactive oxygen or nitrogen species can yield reactive products ...

https://en.wikipedia.org/wiki/Oxidative_stress

... triggers reactive oxygen species (ROS). ROS production disrupts protein folding and induces the unfolded protein ...

https://en.wikipedia.org/wiki/Pardaxin

Agarwal, Ashok; Saleh, Ramadan A.; Bedaiwy, Mohamed A. (2003). "Role of reactive oxygen species in the pathophysiology of human ... de Lamirande, E (1997-01-01). "Reactive oxygen species and sperm physiology". Reviews of Reproduction. 2 (1): 48-54. doi: ... Oxidative stress: Oxidative stress denotes the imbalance of activity between reactive oxygen species (ROS) and endogenous ...

https://en.wikipedia.org/wiki/Sperm_Chromatin_Structure_Assay

This can take place during tissue ischaemia, when oxygen delivery is blocked. Superoxide is a reactive oxygen species that ... perhaps because of reactive oxygen species (complex I can, like complex III, leak electrons to oxygen, forming highly toxic ... "The dependence of brain mitochondria reactive oxygen species production on oxygen level is linear, except when inhibited by ... Esterházy D, King MS, Yakovlev G, Hirst J (March 2008). "Production of reactive oxygen species by complex I (NADH:ubiquinone ...

https://en.wikipedia.org/wiki/Respiratory_complex_I

... semialdehyde threonyl to amino ketobutyric acid Carbonylation is typically assumed to be the result of reactive oxygen species ... ROS species include hydroperoxide or lipic hydroperoxides. Protein carbonylation is of interest because of its association with ... Reactive oxygen species, Post-translational modification). ...

https://en.wikipedia.org/wiki/Protein_carbonylation

Oxidative stress Reactive oxygen species "Ergothioneine". PubChem, National Center for Biotechnology Information, US National ... Although many species contain ergothioneine, only a few make it; the others absorb it from their diet or, in the case of plants ... Other species of bacteria, such as Bacillus subtilis, Escherichia coli, Proteus vulgaris, and Streptococcus, as well as fungi ... Levels can be variable, even within species and some tissues can contain much more than others. In the human body, the largest ...

https://en.wikipedia.org/wiki/Ergothioneine

It is a very important enzyme in protecting the cell from oxidative damage by reactive oxygen species (ROS). Catalase has one ... Winterbourn CC, Kettle AJ, Hampton MB (June 2016). "Reactive Oxygen Species and Neutrophil Function". Annual Review of ... to transfer between the oxygen atoms. The free oxygen atom coordinates, freeing the newly formed water molecule and Fe(IV)=O. ... The oxygen oxidizes the hydroquinones and also acts as the propellant. The oxidation reaction is very exothermic (ΔH = −202.8 ...

https://en.wikipedia.org/wiki/Catalase

There are 3 main pathways for the generation of reactive oxygen species or reactive nitrogen species (RNS) in effector cells: ... Respiratory burst (or oxidative burst) is the rapid release of the reactive oxygen species (ROS), superoxide anion (O− 2) and ... Fang FC (6 September 2011). "Antimicrobial actions of reactive oxygen species". mBio. 2 (5). doi:10.1128/mBio.00141-11. PMC ... Forman HJ, Torres M (December 2002). "Reactive oxygen species and cell signaling: respiratory burst in macrophage signaling". ...

https://en.wikipedia.org/wiki/Respiratory_burst

... the unreduced oxygen molecules in the mitochondrial cortex may accumulate and begin to produce reactive oxygen species. It is ... Adam-Vizi V (2005). "Production of reactive oxygen species in brain mitochondria: contribution by electron transport chain and ... Apel K, Hirt H (2004). "Reactive oxygen species: metabolism, oxidative stress, and signal transduction". Annual Review of Plant ... Murphy MP (January 2009). "How mitochondria produce reactive oxygen species". The Biochemical Journal. 417 (1): 1-13. doi: ...

https://en.wikipedia.org/wiki/MTORC1

Belikov AV, Schraven B, Simeoni L (October 2015). "T cells and reactive oxygen species". Journal of Biomedical Science. 22: 85 ... T cell activation is modulated by reactive oxygen species. A unique feature of T cells is their ability to discriminate between ... This process is an important component of central tolerance and serves to prevent the formation of self-reactive T cells that ...

https://en.wikipedia.org/wiki/T_cell

Reverse electron transfer supports the highest rate of mitochondrial Reactive Oxygen Species (ROS) production, and complex I ... E.; Starkov, A. A. (2005). "Mitochondrial metabolism of reactive oxygen species". Biochemistry (Moscow). 70 (2): 200-214. doi: ... "Sites of reactive oxygen species generation by mitochondria oxidizing different substrates". Redox Biology. 1 (1): 304-312. doi ... "The Oxygen Free Radicals Originating from Mitochondrial Complex I Contribute to Oxidative Brain Injury Following Hypoxia- ...

https://en.wikipedia.org/wiki/Reverse_electron_flow

Alom-Ruiz SP, Anilkumar N, Shah AM (June 2008). "Reactive oxygen species and endothelial activation". Antioxidants & Redox ... reactive oxygen species formation, and coagulatory pathways. High, uniform laminar shear stress is known to promote a quiescent ... the interplay between reactive oxygen species (ROS) and nitric oxide (NO) and the pathophysiological implications". Journal of ... "Mitochondrial Reactive Oxygen Species Mediate Lysophosphatidylcholine-Induced Endothelial Cell Activation". Arteriosclerosis, ...

https://en.wikipedia.org/wiki/Endothelial_activation

Reactive Oxygen Species (ROS): ROS are produced through numerous processes in our cells, including the induction of oxidative ... Dan Dunn J, Alvarez LA, Zhang X, Soldati T (December 2015). "Reactive oxygen species and mitochondria: A nexus of cellular ... Taverne YJ, Bogers AJ, Duncker DJ, Merkus D (2013-04-22). "Reactive oxygen species and the cardiovascular system". Oxidative ... Montezano AC, Touyz RM (May 2012). "Molecular mechanisms of hypertension--reactive oxygen species and antioxidants: a basic ...

https://en.wikipedia.org/wiki/Cardiovascular_disease_in_women

... has been shown to interact with multiple signaling pathways including; ITGB1BP1., reactive oxygen species, cell death, ... "KRIT1 regulates the homeostasis of intracellular reactive oxygen species". PLOS ONE. 5 (7): e11786. Bibcode:2010PLoSO...511786G ...

https://en.wikipedia.org/wiki/KRIT1

Role of hypoxia and reactive oxygen species". Reproductive Toxicology (Elmsford, N.Y.). 13 (2): 93-101. doi:10.1016/s0890-6238( ...

https://en.wikipedia.org/wiki/Almokalant

Mitochondrial SNO-proteins inhibit Complex I of the electron transport chain; modulate mitochondrial reactive oxygen species ( ... Moreover, the biliary secretion of NO species was significantly diminished in UDCA-infused transport mutant [ATP-binding ... it has been proposed that exogenous GSNO could be used to regulate circulating levels of NO and NO-derived species, and GSNO ...

https://en.wikipedia.org/wiki/S-Nitrosoglutathione

Tomato plants protect against cold stress with anthocyanins countering reactive oxygen species, leading to a lower rate of cell ... Breusegem, Frank Van; Dat, James F. (1 June 2006). "Reactive Oxygen Species in Plant Cell Death". Plant Physiology. 141 (2): ... October 2008). "Singlet oxygen quenching by anthocyanin's flavylium cations". Free Radical Research. 42 (10): 885-91. doi: ... Anthocyanins occur in the flowers of many plants, such as the blue poppies of some Meconopsis species and cultivars. ...

https://en.wikipedia.org/wiki/Anthocyanin

Production of reactive oxygen species could occur. This increases oxidative stress and induce lipid peroxidation and could ... Although fumonisin could damage DNA directly by production of reactive oxygen species. Mouse embryos were exposed to FB1 and ... production of reactive oxygen species) and lipid peroxidation. Hepatic and renal tumors could also be due to apoptosis by FB1. ... Fumonisin B1 is the most prevalent member of a family of toxins, known as fumonisins, produced by several species of Fusarium ...

https://en.wikipedia.org/wiki/Fumonisin_B1

Bergamini, Carlo M.; Gambetti, Stefani; Dondi, Alessia; Cervellati, Carlo (2004). "Oxygen, Reactive Oxygen Species and Tissue ... seemingly as a result of increased generation of reactive oxidative species (ROS). This is a plausible mechanism, as there is a ... "Extrapolating Brain Development from Experimental Species to Humans". NeuroToxicology. 28 (5): 931-37. doi:10.1016/j.neuro. ...

https://en.wikipedia.org/wiki/Neurotoxin

A variety of reactive oxygen species (ROS) are generated by plants during times of stress (biotic and abiotic) including UV ... Sakamoto, M., I. Munemura, R. Tomita, & K. Kobayashi (2008). Reactive oxygen species in leaf abscission signaling. Plant Signal ... This step can occur in a variety of ways depending on the species but always occurs at the abscission zone. Detachment can ... Steps 2 and 3 may occur in either order depending on the species. Resorption involves degrading chlorophyll to extract the ...

https://en.wikipedia.org/wiki/Abscission

Reactive oxygen species degrade polyunsaturated lipids, forming malondialdehyde. This compound is a reactive aldehyde and is ... Farmer EE, Davoine C (2007). "Reactive electrophile species". Curr. Opin. Plant Biol. 10 (4): 380-6. doi:10.1016/j.pbi.2007.04. ... Malondialdehyde is reactive and potentially mutagenic. It has been found in heated edible oils such as sunflower and palm oils ... one of the many reactive electrophile species that cause toxic stress in cells and form covalent protein adducts referred to as ...

https://en.wikipedia.org/wiki/Malondialdehyde

Corpas FJ, Barroso JB, del Río LA (April 2001). "Peroxisomes as a source of reactive oxygen species and nitric oxide signal ... They perform key roles in lipid metabolism and the conversion of reactive oxygen species. Peroxisomes are involved in the ... There is evidence now that those reactive oxygen species including peroxisomal H2O2 are also important signalling molecules in ... Bonekamp NA, Völkl A, Fahimi HD, Schrader M (2009). "Reactive oxygen species and peroxisomes: struggling for balance". ...

https://en.wikipedia.org/wiki/Peroxisome

Furthermore, cells release reactive oxygen species and cytokines, which cause secondary damage to surrounding tissue. These ... "Reactive Oxygen Species in Inflammation and Tissue Injury". Antioxidants & Redox Signaling. 20 (7): 1126-1167. doi:10.1089/ars. ... Xenograft, from a donor of a different species from the recipient, heart valves can be from either pigs, cows, or sheep. If ...

https://en.wikipedia.org/wiki/Tissue_engineering_of_heart_valves

... also confers resistance to reactive oxygen species. The amount of isoprene released from isoprene-emitting vegetation ... Many species of soil and marine bacteria, such as Actinomycetota, are capable of degrading isoprene and using it as a fuel ... These new species can dissolve into water droplets and contribute to aerosol and haze formation. Secondary organic aerosols ... Isoprene is produced and emitted by many species of trees (major producers are oaks, poplars, eucalyptus, and some legumes). ...

https://en.wikipedia.org/wiki/Isoprene

Biochemical markers like creatine kinase, Reactive oxygen species. When performing cryopreservation of semen, it is the sperm ... report demonstrated evidence of the effects of feminizing chemicals on male development in each class of vertebrate species as ...

https://en.wikipedia.org/wiki/Semen_quality

In the early years, Ashok and his team at ACRM studied the physiological levels of reactive oxygen species (ROS) and its ... Sharma, RK; Agarwal, A (1996). "Role of reactive oxygen species in male infertility". Urology. 48 (6): 835-50. doi:10.1016/ ... Sharma, RK; Pasqualotto, FF; Nelson, DR; Thomas, AJ Jr.; Agarwal, A (1999). "The reactive oxygen species-total antioxidant ... Agarwal, A; Saleh, RA; Bedaiwy, MA (2003). "Role of reactive oxygen species in the pathophysiology of human reproduction". ...

https://en.wikipedia.org/wiki/Ashok_Agarwal

The main differences between the surface water and groundwater concern the oxygen concentration, the temperature and the pH. As ... Researchers use tools such as wells and piezometers, conservative and reactive tracers, and transport models that account for ... Examples include: Habitat and shelter for different species of fish, aquatic plants and interstitial organisms; Reduction of ... Conversely, stream water from the main channel contains higher dissolved oxygen and lower nutrients. This creates a ...

https://en.wikipedia.org/wiki/Hyporheic_zone

The breakdown of glucose produces reactive oxygen species (ROS). These induce extracellular Daxx to translocalize into the ...

https://en.wikipedia.org/wiki/Death-associated_protein_6

It is able to protect the cell from reactive oxygen species produced from exposure to UV by acting as a target. The ... To obtain more oxygen, H. salinarum produce gas vesicles, which allow them to float to the surface where oxygen levels are ... The researchers found 10 species of halophilic bacteria and archaea as well as several species of Dunaliella algae, nearly all ... H. salinarum can grow to such densities in salt ponds that oxygen is quickly depleted. Though it is an obligate aerobe, it is ...

https://en.wikipedia.org/wiki/Halobacterium_salinarum

... including oxidative phosphorylation and the formation of disulfide bonds during protein folding produce reactive oxygen species ... ISBN 0-226-73936-8. Lane N (2004). Oxygen: The Molecule that Made the World. USA: Oxford University Press. ISBN 0-19-860783-0. ... Organic compounds (proteins, lipids and carbohydrates) contain the majority of the carbon and nitrogen; most of the oxygen and ... In plants, algae, and cyanobacteria, photosystem II uses light energy to remove electrons from water, releasing oxygen as a ...

https://en.wikipedia.org/wiki/Metabolism

2004). "Reactive oxygen species produced by NAD(P)H oxidase inhibit apoptosis in pancreatic cancer cells". J. Biol. Chem. 279 ( ... Nox-dependent reactive oxygen species modulation by amino endoperoxides can induce apoptosis in high Nox4-expressing cancer ... A phagocyte-type oxidase, similar to that responsible for the production of large amounts of reactive oxygen species (ROS) in ... H oxidase 4 isozyme is essential for lipopolysaccharide-induced production of reactive oxygen species and activation of NF- ...

https://en.wikipedia.org/wiki/NOX4

Cu2+ and Cu+ species co-exist in solution due to the generation of reducing Fe2+ species at the cathode. The best selective ... Chemically, the precious metals tend to be less reactive than most elements. They include gold and silver, but also the so- ... capability of the protons to act as oxygen acceptors, and on the temperature. It has been reported that eutectic ionic fluids ... formation of polysulfide species,). The presence of Cl− ions has been suggested to alter the morphology of any sulfide surface ...

https://en.wikipedia.org/wiki/Extractive_metallurgy

... hydroxyl radical and eventually other reactive species including other peroxides and singlet oxygen, which can, in turn, ... These adducts can further rearrange to form reactive species, which can then cross-link the structural proteins or DNA to ... A species that uses resources more efficiently will live longer, and therefore be able to pass on genetic information to the ... Some species exhibit "negative senescence", in which reproduction capability increases or is stable, and mortality falls with ...

https://en.wikipedia.org/wiki/Senescence

It also functions as a signal transducer/integrator to regulate the MAPK pathway, reactive oxygen species (ROS), as well as ... mitochondrial reactive oxygen species (ROS) production, as well as activation of phospholipase C (PLC) and inositol ... A cell's osmolarity is the sum of the concentrations of the various ion species and many proteins and other organic compounds ... At position 312, insects feeding on Apocynum species differed from mammalian Na⁺/K⁺-ATPase through the change of glutamic acid ...

https://en.wikipedia.org/wiki/Sodium–potassium_pump

His studies involve Reactive oxygen species, Inflammation, Small GTP-Binding Proteins, hypertrophy, hypertension and ...

https://en.wikipedia.org/wiki/Pascal_J._Goldschmidt

Heme acts as a toxic molecule that can generate oxygen-reactive species and bypass membranes due to its high permeability. ... This species has an overall sex ratio of 2:1 for males to females, so males outnumber females. Males of the species complex are ... The sandfly species are attracted to the specific carbohydrate composition of this plant species over others. Spiegel, Carolina ... L. longipalpis has only recently (2017) been accepted as a complex of sibling species as opposed to a heterogeneous species. ...

https://en.wikipedia.org/wiki/Lutzomyia_longipalpis

The concept that mtDNA is particularly susceptible to reactive oxygen species generated by the respiratory chain due to its ... In essence, mutations in mtDNA upset a careful balance of reactive oxygen species (ROS) production and enzymatic ROS scavenging ... Alexeyev MF (October 2009). "Is there more to aging than mitochondrial DNA and reactive oxygen species?". The FEBS Journal. 276 ... higher levels of reactive oxygen species and increased oxidative stress. Mutant huntingtin protein promotes oxidative damage to ...

https://en.wikipedia.org/wiki/Mitochondrial_DNA

"Genome-wide analysis of the regulation of pimaricin production in Streptomyces natalensis by reactive oxygen species". Applied ... Streptomyces natalensis is a bacterial species in the genus Streptomyces. Natamycin is an antifungal agent produced during ... v t e (Articles with short description, Short description matches Wikidata, Articles with 'species' microformats, Streptomyces ...

https://en.wikipedia.org/wiki/Streptomyces_natalensis

... it gives rise to very reactive oxygen specie, which is the active agent of the bleach. Around sixty percent of the world's ... Bleaching with oxygen removes the chromophoric sites and makes the cloths whiter. Oxygen is a degrading bleaching agent. Its ... The atmospheric oxygen and the oxygen left by the grass provide the whitening action. The cloth becomes whiter day by day until ... The linen fabrics are laid on the grass or ground for weeks . The oxygen of the air and that given off by green plants Sansone ...

https://en.wikipedia.org/wiki/Grassing_(textiles)

Unlike many mold species, Aspergillus flavus prefers hot and dry conditions. Its optimal growth at 37 °C (99 °F) contributes to ... These enzymes use both molecular oxygen and two NADPH's to dehydrate one of the hydroxyl groups on the anthraquinone and open ... Aflatoxin B1 must first be metabolized into its reactive electrophilic form, aflatoxin B1-8,9-exo-epoxide by cytochrome p450. ... Acute toxicity The oral LD50 range of aflatoxin B1 is estimated to be 0.3-17.9 mg/kg body weight for most animal species. For ...

https://en.wikipedia.org/wiki/Aflatoxin_B1

Lin et al., conducted an experiment in Taiwan that tested the effect of generation of reactive oxygen species on temporary ... With the resultant oxygen tension and diminished blood supply reaching the outer hair cells, their response to sound levels is ... The transduction of sounds requires an oxygen supply that will be readily depleted due to the prolonged threshold shifts. When ... Studies[clarification needed] have been done on a variety of animal species, including guinea pigs and dolphins., rats, fish, ...

https://en.wikipedia.org/wiki/Listener_fatigue

YopE GAP activity inhibits two common methods of host immunity - phagocytosis and reactive oxygen species generation. ...

https://en.wikipedia.org/wiki/YopE_protein_domain

It involves the generation of reactive oxygen species (ROS), which have crucial roles in signal transduction or as toxic agents ... Chemi-excitation via oxidative stress by reactive oxygen species and/or catalysis by enzymes (i.e., peroxidase, lipoxygenase) ... Further support is provided by studies indicating that emission can be increased by addition of reactive oxygen species. ... Such reactions can lead to the formation of triplet excited species, which release photons upon returning to a lower energy ...

https://en.wikipedia.org/wiki/Biophoton

Hydroxyl radicals and other reactive oxygen species when generated near DNA can cause point mutations, cross-linkage and breaks ... The oxygen binds to the iron in the heme via affinity-based binding or liganding and dissociates from the protein once it has ... Processes including oxygen transport and DNA replication are carried out using enzymes such as DNA polymerase, which in humans ... In animals, iron plays a very important role in transporting oxygen from the lungs to tissues and CO2 from tissues to the lungs ...

https://en.wikipedia.org/wiki/Biometal_(biology)

... reactive oxygen species and microbial attack to survive, providing defensive phytochemicals of use in herbalism. Indigenous ... Native Americans used about 2,500 of the approximately 20,000 plant species that are native to North America. In Andean healing ... Field biologists have provided corroborating evidence based on observation of diverse species, such as chickens, sheep, ... Society, National Geographic (20 August 2020). "Dividing Species: Wallace Line Map". National Geographic Society. Retrieved 4 ...

https://en.wikipedia.org/wiki/Herbal_medicine

... is an oxidized form of cytosine that is produced by the oxidative deamination of cytosines by reactive oxygen species. It does ...

https://en.wikipedia.org/wiki/5-Hydroxyuracil

... and oxygen. This interaction produces the formation of a highly reactive oxygen species (ROS), usually singlet oxygen, as well ... These high reactive oxygen species react with susceptible cellular organic biomolecules such as; lipids, aromatic amino acids, ... Oxygen Reduction and Hydrogen and Oxygen Evolution Reactions Catalyzed by Porphyrin- and Corrole-Based Systems". Chemical ... Monatomic oxygen. Cellular aging Several heterocycles related to porphyrins are found in nature, almost always bound to metal ...

https://en.wikipedia.org/wiki/Porphyrin

The oxygen pathway predominates at pH 10. This decomposition is affected by light and metal ion catalysts such as copper, ... Urben P (2006). Bretherick's Handbook of Reactive Chemical Hazards. Vol. 1 (7th ed.). p. 1433. ISBN 978-0-08-052340-8. Hamano A ... The following species and equilibria are present in solutions of NaOCl: HOCl (aq) ⇌ H+ + OCl− HOCl (aq) + Cl− + H+ ⇌ Cl 2 (aq ... Catalysts like sodium dichromate Na 2Cr 2O 7 and sodium molybdate Na 2MoO 4 may be added industrially to reduce the oxygen ...

https://en.wikipedia.org/wiki/Sodium_hypochlorite

Also, the oxide, nitride, and carbide films can be readily prepared by introducing reactive gases such as O2, N2, and C2H2. ... Middleburgh, S.C.; King, D.M.; Lumpkin, G.R.; Cortie, M.; Edwards, L. (June 2014). "Segregation and migration of species in the ... In 2018, new types of HEAs based on the careful placement of ordered oxygen complexes, a type of ordered interstitial complexes ... "Enhanced strength and ductility in a high-entropy alloy via ordered oxygen complexes". Phys.org. Bała, Piotr; Górecki, Kamil; ...

https://en.wikipedia.org/wiki/High-entropy_alloy

When mixed with oxygen, it burns with a pale yellowish-green flame. Ignition occurs when chlorine is passed into ammonia, ... Acyl chlorides are the most reactive, but the ammonia must be present in at least a twofold excess to neutralise the hydrogen ... Diamminesilver(I) ([Ag(NH3)2]+) is the active species in Tollens' reagent. Formation of this complex can also help to ...

https://en.wikipedia.org/wiki/Ammonia

The N-terminus of Histatin 5 allows it to bind with metals, and this can result in the production of reactive oxygen species. ... by binding to the potassium transporter and facilitating in the loss of azole-resistant species. The antifungal properties of ...

https://en.wikipedia.org/wiki/Histatin

... on luciferins may have arisen from pressures to protect oceanic organisms from potentially deleterious reactive oxygen species ... Bioluminescence is used by a variety of animals to mimic other species. Many species of deep sea fish such as the anglerfish ... A similar reason may account for the many species of fungi that emit light. Species in the genera Armillaria, Mycena, ... Bioluminescence in bathyal benthic species still remains poorly studied due to difficulties of the collection of species at ...

https://en.wikipedia.org/wiki/Bioluminescence

Some species of bacteria secrete it to form biofilms. Cellulose is the most abundant organic polymer on Earth. The cellulose ... The multiple hydroxyl groups on the glucose from one chain form hydrogen bonds with oxygen atoms on the same or on a neighbor ... Dauenhauer, Paul J.; Colby, Joshua L.; Balonek, Christine M.; Suszynski, Wieslaw J.; Schmidt, Lanny D. (2009). "Reactive ... Typical non-food energy crops include industrial hemp, switchgrass, Miscanthus, Salix (willow), and Populus (poplar) species. A ...

https://en.wikipedia.org/wiki/Cellulose

Conversely, activation of p16 through reactive oxygen species, DNA damage, or senescence leads to the buildup of p16 in tissues ...

https://en.wikipedia.org/wiki/P16

Palladium precatalyst species are activated under reaction conditions to form a reactive Pd0 compound, A. The exact identity of ... and the necessity of strict oxygen exclusion in the reaction mixture. Thus, with the aim of excluding copper from the reaction ... Both activated species, namely complexes B and F, are involved in the transmetallation step, forming complex C and regenerating ... Aliphatic alkynes are generally less reactive. Due to the crucial role of base, specific amines must be added in excess or as ...

https://en.wikipedia.org/wiki/Sonogashira_coupling

... reactive oxygen species), such as singlet-oxygen and free radicals. Therefore, they have the ability to prevent chronic ... Species of Choanephora have highly adherent sporangiole wall in contrast to Blakeslea species where the sporangiole wall is ... This species has been well studied for its ability to produce carotenoids, particularly, β-carotene and lycopene. β-carotene is ... Ho HM, Chang LL (2003). "Notes on Zygomycetes of Taiwan (III): Two Blakeslea Species (Choanephoracease) New to Taiwan". ...

https://en.wikipedia.org/wiki/Blakeslea_trispora

Here we show that the induction of cross-presentation by pDCs is regulated by mitochondria through a reactive oxygen species ( ... inducible cross-presentation by plasmacytoid dendritic cells is modulated by mitochondria-originated reactive oxygen species. ... Reactive oxygen species are essential mediators in antigen presentation by Kupffer cells. Immunol. Cell Biol. 83, 336-343 (2005 ... Mitochondrial reactive oxygen species regulate the induction of CD8+ T cells by plasmacytoid dendritic cells. *Marine Oberkampf ...

https://www.nature.com/articles/s41467-018-04686-8?error=cookies_not_supported&code=0e4ec41d-0a6d-43b8-91eb-ee09a698256a

... Br J Pharmacol. 2017 Jun;174 ... Reactive oxygen species (ROS) can act as damaging molecules but also represent central hubs in cellular signalling networks. ...

https://pubmed.ncbi.nlm.nih.gov/28332701/

... increased reactive oxygen species levels and stimulated HIF-1α protein stabilization in endometrial stromal cells, and that CS- ... Figure 6. Critical involvement of reactive oxygen species (ROS) in HIF-1α activation. (A) KC02-44D cells exposed to 1% or 2% ... Figure 6. Critical involvement of reactive oxygen species (ROS) in HIF-1α activation. (A) KC02-44D cells exposed to 1% or 2% ... cigarette smoking; hypoxia-inducible factor; HIF; CS extract; endometrial stromal cell; reactive oxygen species; immortalized ...

https://www.mdpi.com/2076-3921/10/1/48

... differing structural conformations in freshwater through a mechanism that requires the formation of reactive oxygen species ( ... Reactive Oxygen Species (ROS) mediated degradation of organophosphate T pesticides by the green microalgae Coccomyxa ... differing structural conformations in freshwater through a mechanism that requires the formation of reactive oxygen species ( ...

https://digitalcommons.unl.edu/biochemfacpub/490/

... directly scavenge reactive oxygen species (ROS) and reactive nitrogen species (RNS) species and protect cells against a host of ... Reactive Nitrogen Species, Reactive Oxygen Species, Signal Transduction, Thioctic Acid, Transcription, Genetic. ... Is alpha-lipoic acid a scavenger of reactive oxygen species in vivo? Evidence for its initiation of stress signaling pathways ... Is alpha-lipoic acid a scavenger of reactive oxygen species in vivo? Evidence for its initiation of stress signaling pathways ...

https://lpi.oregonstate.edu/biblio/alpha-lipoic-acid-scavenger-reactive-oxygen-species-vivo-evidence-its-initiation-stress

Aminoguanidine inhibits reactive oxygen species formation, lipid peroxidation, and oxidant-induced apoptosis. ... Aminoguanidine inhibits reactive oxygen species formation, lipid peroxidation, and oxidant-induced apoptosis. Journal Article ( ... oxidant-induced intracellular reactive oxygen species (ROS) production, and lipid peroxidation were determined in rat retinal ...

https://scholars.duke.edu/display/pub1362576

https://www.rosj.org/index.php/ros/login?source=%2Findex.php%2Fros%2Farticle%2Fview%2F315%2F487

Mitochondrial Reactive Oxygen Species Generation Initiates the Hypoxic Pulmonary Vasoconstriction Response. *Waypa, Gregory B ( ...

https://www.scholars.northwestern.edu/en/projects/mitochondrial-reactive-oxygen-species-generation-initiates-the-hy-6

Indexed and Abstracted in : SCOPUS, Scimago Journal Ranking, Chemical Abstracts, Excerpta Medica / EMBASE, Google Scholar, CABI Full Text, Index Copernicus, Ulrichs International Periodical Directory, ProQuest, Journalseek & Genamics, PhcogBase, EBSCOHost, Academic Search Complete, Open J-Gate, SciACCESS ...

https://www.phcogj.com/tags/reactive-oxygen-species-1

Ensulizole can damage the DNA through the generation of reactive oxygen species (ROS) upon UV or sunlight irradiation. ... D-α-Hydroxyglutaric acid increases reactive oxygen species (ROS) production. D-α-Hydroxyglutaric acid binds and inhibits ATP ... 5-Galloylquinic acid, an main scavenger of the reactive oxygen species (ROS) in green tea. ... Buprofezin also dose-dependently increases the production of reactive oxygen species (ROS) in vitro. ...

https://www.dcchemicals.com/products/reactive_oxygen_species.html

Hybrid vesicles as intracellular reactive oxygen species and nitric oxide generators. Publikation: Bidrag til tidsskrift/ ...

https://pure.au.dk/portal/da/persons/edit-brodszkij

... Retta SF;Chiarugi P;TRABALZINI, LORENZA;Pinton P;Belkin AM ... Retta, S.f., Chiarugi, P., Trabalzini, L., Pinton, P., Belkin, A.m. (2012). Reactive oxygen species: friends and foes of signal ... Retta, S.f., Chiarugi, P., Trabalzini, L., Pinton, P., Belkin, A.m. (2012). Reactive oxygen species: friends and foes of signal ... The maintenance of highly regulated mechanisms to control intracellular levels of reactive oxygen species (ROS) is essential ...

https://usiena-air.unisi.it/handle/11365/42974

Tag: Reactive Oxygen Species. To look for the loading and maintenance dose of glutathione (GSH). To look for the loading and ... Reactive Oxygen Species, several methods for modifying the toxicity of paraquat have been examined: a) prevention of absorption ... for individuals suffering from reactive oxygen varieties (ROS) injury such as acute paraquat intoxication, a kinetic study of ... ingestion of paraquat is frequently fatal within a few days due to multiple-organ failure mediated by reactive oxygen varieties ...

http://www.researchtoactionforum.org/tag/reactive-oxygen-species/

Sies H, Jones DP: Reactive oxygen species (ROS) as pleiotropic physiological signalling agents. Nat Rev Mol Cell Biol 21(7): ... Sies H, Jones DP: Reactive oxygen species (ROS) as pleiotropic physiological signalling agents. Nat Rev Mol Cell Biol 21(7): ...

https://iuf-duesseldorf.de/portfolio/sies-h-jones-dp-reactive-oxygen-species-ros-as-pleiotropic-physiological-signalling-agents-nat-rev-mol-cell-biol-217-363-383-2020-doi-10-1038-s41580-020-0230-3/

... ...

https://uvaauas.figshare.com/articles/dataset/RDM-Photo-activated_thin_films_of_porphyrins_for_reactive_oxygen_species_generation/18865448

Reactive oxygen species (ROS) and their products are components of cell signaling pathways and play important roles in cellular ... 1. Pathophysiology of Reactive Oxygen Species and Antioxidant Defenses. Reactive oxygen species (ROS) are highly reactive ... M. J. Morgan and Z.-G. Liu, "Crosstalk of reactive oxygen species and NF-κB signaling," Cell Research, vol. 21, no. 1, pp. 103- ... X. Shi, Y. Zhang, J. Zheng, and J. Pan, "Reactive oxygen species in cancer stem cells," Antioxidants and Redox Signaling, vol. ...

https://www.hindawi.com/journals/omcl/2016/6235641/

Reactive oxygen species (ROS)-related therapy has attracted increasing attention in the last decade. It has advantages in high ... Special Issue "Recent Progress in Reactive Oxygen Species-Related Therapy for Disease Treatment". * Special Issue Editors ... This article belongs to the Special Issue Recent Progress in Reactive Oxygen Species-Related Therapy for Disease Treatment). ... This article belongs to the Special Issue Recent Progress in Reactive Oxygen Species-Related Therapy for Disease Treatment). ...

https://www2.mdpi.com/journal/pharmaceutics/special_issues/D00R8YA626

Nitric oxide reactive oxygen species their interplay and detoxification in Neisseria meningitidis. *Moir, James (Principal ... Thomson, M. J., Stevanin, T. M. & Moir, J. W. B., 2008, GLOBINS AND OTHER NITRIC OXIDE-REACTIVE PROTEINS, PART B. SAN DIEGO: ...

https://pure.york.ac.uk/portal/en/projects/nitric-oxide-reactive-oxygen-species-their-interplay-and-detoxifi

A common feature of many of these external stresses is the production of reactive oxygen species (ROS). Taking into account ... SUMO E3 ligase SIZ1 connects sumoylation and reactive oxygen species homeostasis processes in Arabidopsis.. Castro, Pedro ...

https://pesquisa.bvsalud.org/bvsecuador/resource/es/mdl-35238389

... skin and cellular reactive oxygen species (ROS) levels were detected by DHE and DCF fluorescent probes, mitochondrial membrane ... skin and cellular reactive oxygen species (ROS) levels were detected by DHE and DCF fluorescent probes, mitochondrial membrane ... The Detection of Reactive Oxygen Species for Skin Tissue and Cell. A red fluorescent reactive oxygen probe, DHE, can be used to ... Drigotas, M., Affolter, A., Mann, W. J., and Brieger, J. (2013). Reactive Oxygen Species Activation of MAPK Pathway Results in ...

https://www.frontiersin.org/articles/10.3389/fphar.2021.728261/full

ORCID: 0000-0002-8572-9065 (2012) Do reactive oxygen species regulate skeletal muscle glucose uptake during contraction? ...

https://vuir.vu.edu.au/22101/

Key words: pepper, methyl jasmonate, bacterial wilt, induced resistance, enzymes related to reactive oxygen species metabolism ... The indexes of bacterial wilt，the activities of enzymes related to reactive oxygen species（ROS）metabolism including superoxide ... Involvement of Induced Resistance by Methyl Jasmonate to Bacterial Wilt and Reactive Oxygen Species Metabolism in Pepper ... induced resistance to bacterial wilt and enzymes related to reactive oxygen species metabolism in pepper，the susceptible ...

https://www.ahs.ac.cn/EN/Y2017/V44/I10/1985

... ... Effects of Alkaline Stress on the Metabolism of Reactive Oxygen Species and Osmotica Accumulation in Ryegrass Seedling Roots[J ... metabolism of reactive oxygen species (ROS) and osmotica accumulation in roots were studied by a sandy culture in greenhouse. ... Effects of KCl on Active Oxygen Metabolism and Osmotica Accumulation in Avena nude L. Seedlings under NaCl Stress [J]. Bulletin ...

http://bbr.nefu.edu.cn/EN/abstract/abstract666.shtml

Reactive oxygen species (ROS; e.g., superoxide [O2•-] and hydrogen peroxide [H2O2]) and reactive nitrogen species (RNS; e.g., ... N2 - Reactive oxygen species (ROS; e.g., superoxide [O2•-] and hydrogen peroxide [H2O2]) and reactive nitrogen species (RNS; e. ... AB - Reactive oxygen species (ROS; e.g., superoxide [O2•-] and hydrogen peroxide [H2O2]) and reactive nitrogen species (RNS; e. ... abstract = "Reactive oxygen species (ROS; e.g., superoxide [O2•-] and hydrogen peroxide [H2O2]) and reactive nitrogen species ( ...

https://augusta.elsevierpure.com/en/publications/interplay-between-reactive-oxygenreactive-nitrogen-species-and-me

Reactive Oxygen Species Stimulate Insulin Secretion in Rat Pancreatic Islets: Studies Using Mono-Oleoyl-Glycerol. ...

https://www.mattek.com/reference_library/reactive-oxygen-species-stimulate-insulin-secretion-in-rat-pancreatic-islets-studies-using-mono-oleoyl-glycerol/

... "Intracellular Reactive Oxygen Species Mediate the Therapeutic Effect of Induced Pluripotent Stem Cells for Acute Kidney Injury ...

https://www.medibeacon.com/preclinical_pub/intracellular-reactive-oxygen-species-mediate-the-therapeutic-effect-of-induced-pluripotent-stem-cells-for-acute-kidney-injury/

It scavenges reactive oxygen and nitrogen species and increases antioxidant defenses, thus it prevents tissue damage and blocks ... serving as a scavenger for reactive oxygen species (ROS) and reactive nitrogen species (RNS) [27]. Melatonin and its ... Effects of melatonin and its metabolites on reactive nitrogen species. Reactive nitrogen species represent another category of ... are defined as reactive oxygen species (ROS). ROS are produced during the oxygen metabolism. Nitrogen-derived radicals and ...

https://www.intechopen.com/chapters/62672

... or reactive oxygen species scavenger (para-aminobenzoic acid), we suppose that ethanol promotes the formation of reactive ... reactive oxygen species and protects DNA against UV and free radical damage. ... We have hypothesized that PABA may be an effective scavenger of reactive oxygen species. In this report, we showed that PABA ... In addition, overexpression of Pabs leads to an elevated reactive oxygen species production at root tips and enhanced catalase ...

https://www.researchgate.net/publication/311631607_Vitamin_Para-Aminobenzoic_Acid_PABA_Controls_Generation_of_Nitric_Oxide_NO_In_Vitro_and_its_Biological_Functions_in_the_Bacterial_Cells

As oxidative DNA damage is caused by reactive oxygen species (ROS), systematic review and meta-analysis were also conducted to ... Meta-analysis of reactive oxygen species in (A) schizophrenia and (B) depression.[49-57] ... Flow diagram of study selection for systematic review and meta-analysis of reactive oxygen species (ROS). ... "reactive oxygen species" OR "ROS" OR "hydrogen peroxide" OR "superoxide radical" OR "hydroxyl radical") AND ("major mental ...

https://www.psychiatryinvestigation.org/journal/view.php?number=1349

In this study, the effects of preincubation with AG on oxidant-induced apoptosis, oxidant-induced intracellular reactive oxygen species (ROS) production, and lipid peroxidation were determined in rat retinal Müller cells and compared with the effects of NGF, a protein that protects neuronal cells from oxidative stress. (duke.edu)
The maintenance of highly regulated mechanisms to control intracellular levels of reactive oxygen species (ROS) is essential for normal cellular homeostasis. (unisi.it)

Aminoguanidine inhibits reactive oxygen species formation, lipid peroxidation, and oxidant-induced apoptosis. (duke.edu)
Diallyl Trisulfide suppresses the growth of Penicillium expansum (MFC99 value: ≤ 90 μg/mL) and promotes apoptosis via production of reactive oxygen species (ROS) and disintegration of cellular ultrastructure. (dcchemicals.com)

H 2 O 2 is the more stable and diffusible form of ROS, it is selectively reactive towards cysteine residues on proteins, and, in the low nanomolar range, it can control cellular signaling (Figure 1 ). (hindawi.com)
This lack of reactive oxygen species causes the body to overcompensate by activating more immune cells and producing more immune proteins. (medlineplus.gov)

A significant number of studies now show that LA and its reduced form, dihydrolipoic acid (DHLA), directly scavenge reactive oxygen species (ROS) and reactive nitrogen species (RNS) species and protect cells against a host of insults where oxidative stress is part of the underlying etiology. (oregonstate.edu)
Electron spin resonance and flow cytometry studies showed that superoxide is the primary oxidative species induced by DOX and responsible for the death inducing effect. (cdc.gov)
Recent source of free radicals8 which can also deplete study carried out by a local research body, scavengers of reactive oxygen species (ROS), indicated an increase in the rate of teenage accentuating oxidative damage9. (who.int)

Effects of Exogenous Nitric Oxide on Active Oxygen Metabolism, Polyamine Content and Photosynthesis of Ryegrass( Lolium perenne L.) Seedlings Under Salt Stress [J]. Bulletin of Botanical Research, 2009, 29(3): 313-319. (nefu.edu.cn)

To explore the relationship between methyl jasmonate（MeJA）-induced resistance to bacterial wilt and enzymes related to reactive oxygen species metabolism in pepper，the susceptible variety'Yuehong 1'and resistant variety'Xinxiang 8'were used as the experimental materials in the study. (ahs.ac.cn)
The indexes of bacterial wilt，the activities of enzymes related to reactive oxygen species（ROS）metabolism including superoxide dismutase（SOD），catalase（CAT），peroxidase（POD）and ascorbate peroxidase（APX），and the contents of malondialdehyde（MDA）were determined. (ahs.ac.cn)
These results suggested that MeJA induced resistance to bacterial wilt in pepper seedlings，and the increased activities of enzymes related to reactive oxygen species metabolism and the decreased lipid peroxidation might be involved in this resistance induction. (ahs.ac.cn)
To explore the tolerant extent of ryegrass seedlings to alkaline stress, ryegrass seedlings were exposed to Hoagland's nutrient solution with NaHCO 3 added (0, 50, 100, 150, 200 mmol·L -1 ), and the effects of NaHCO 3 stress on the growth of roots, metabolism of reactive oxygen species (ROS) and osmotica accumulation in roots were studied by a sandy culture in greenhouse. (nefu.edu.cn)
Effects of KCl on Active Oxygen Metabolism and Osmotica Accumulation in Avena nude L. Seedlings under NaCl Stress [J]. Bulletin of Botanical Research, 2015, 35(2): 233-239. (nefu.edu.cn)

This enzyme participates in a chemical reaction that converts oxygen to a toxic molecule called superoxide. (medlineplus.gov)

Is alpha-lipoic acid a scavenger of reactive oxygen species in vivo? (oregonstate.edu)
5-Galloylquinic acid, an main scavenger of the reactive oxygen species (ROS) in green tea. (dcchemicals.com)

Do reactive oxygen species regulate skeletal muscle glucose uptake during contraction? (edu.au)

SUMO E3 ligase SIZ1 connects sumoylation and reactive oxygen species homeostasis processes in Arabidopsis. (bvsalud.org)

This study found that metabolically active cultures of the microalga C. subellipsoidea breakdown organophosphates (paraoxon, malathion and diazinon) with differing structural conformations in freshwater through a mechanism that requires the formation of reactive oxygen species (ROS) with little to no toxic effects on the algae. (unl.edu)
These highly reactive, toxic substances are known as reactive oxygen species. (medlineplus.gov)

Reactive oxygen species (ROS) can act as damaging molecules but also represent central hubs in cellular signalling networks. (nih.gov)
Reactive oxygen species (ROS) are highly reactive molecules that are principally derived from the oxygen that is consumed in various metabolic reactions occurring mainly in the mitochondria, peroxisomes, and the endoplasmic reticulum. (hindawi.com)

Here we show that the induction of cross-presentation by pDCs is regulated by mitochondria through a reactive oxygen species (ROS)-dependent mechanism, involving pH alkalization and antigen protection. (nature.com)

RAW264.7 cells exposed to MMA-SS had elevated generation of reactive oxygen species (ROS), protein-HNE (P-HNE) adduct formation, activation of ERK1/2, and expression of cyclooxygenase-2 (COX-2) compared to GMA-MS and control. (cdc.gov)
Treatment of the cells with DOX induced reactive oxygen species (ROS) generation and a concomitant increase in apoptotic cell death through the mitochondrial death pathway independent of p53. (cdc.gov)
The in vitro effects of metronidazole on the production of reactive oxygen species by polymorphonuclear [‎PMN]‎ cells were studied by means of nitroblue tetrazolium and luminol-dependent chemiluminescence. (who.int)

Signaling by carcinogenic metals and metal-induced reactive oxygen species. (cdc.gov)

As a result, fewer reactive oxygen species are produced when foreign invaders trigger an immune reaction. (medlineplus.gov)

Sies H, Jones DP: Reactive oxygen species (ROS) as pleiotropic physiological signalling agents. (iuf-duesseldorf.de)
Reactive oxygen species (ROS) as pleiotropic physiological signalling agents. (iuf-duesseldorf.de)

Ensulizole can damage the DNA through the generation of reactive oxygen species (ROS) upon UV or sunlight irradiation. (dcchemicals.com)
Generation of reactive oxygen species by silicon nanowires. (cdc.gov)

As a result, phagocytes are unable to produce reactive oxygen species to kill foreign invaders and neutrophil activity is not regulated. (medlineplus.gov)

Tetrahydroxyquinone hydrate can take part in a redox cycle with semiquinone radicals, leading to the formation of reactive oxygen species (ROS). (dcchemicals.com)

Camalexin can induce reactive oxygen species (ROS) production. (dcchemicals.com)
D-α-Hydroxyglutaric acid increases reactive oxygen species (ROS) production. (dcchemicals.com)
Buprofezin also dose-dependently increases the production of reactive oxygen species (ROS) in vitro. (dcchemicals.com)
A common feature of many of these external stresses is the production of reactive oxygen species (ROS). (bvsalud.org)
At therapeutic doses of metronidazole [‎4.98-24.86 microg/mL]‎ significant inhibition of the production of reactive oxygen species was noted in both methods. (who.int)

Skin damage was observed using hematoxylin-eosin (HE) and Masson staining, skin and cellular reactive oxygen species (ROS) levels were detected by DHE and DCF fluorescent probes, mitochondrial membrane potential was detected by JC-1 staining, and protein expressions were detected by immunofluorescence and Western Blot. (frontiersin.org)

The next largest category (6 articles) included papers describing evolutionary selection pressures on infectious organisms, either in the natural environment or in host species. (cdc.gov)

These highly reactive, toxic substances are known as reactive oxygen species. (medlineplus.gov)
Stressors trigger the cell to make what are known as reactive oxygen species. (nih.gov)

Reactive Oxygen Species Activatable Heterodimeric Prodrug as Tumor-Selective Nanotheranostics. (nih.gov)

Cadmium inhibits the electron transfer chain and induces reactive oxygen species. (cdc.gov)
Indeed, in follow-up experiments, the misacylation was blocked by a compound that inhibits cells from generating reactive oxygen species, implicating the molecules as the trigger for misacylation. (nih.gov)

The formation of reactive oxygen species (ROS) by the myeloid cell NADPH oxidase NOX2 is critical for the destruction of engulfed microorganisms. (nih.gov)

This enzyme participates in a chemical reaction that converts oxygen to a toxic molecule called superoxide. (medlineplus.gov)
The semiubiquinones, being unstable, are prone to transfer one electron to molecular oxygen to form superoxide, providing a possible mechanism for Cd-induced generation of ROS in mitochondria. (cdc.gov)

Reactive oxygen species (ROS) have been implicated in the pathogenesis of cancer. (cdc.gov)

As a result, fewer reactive oxygen species are produced when foreign invaders trigger an immune reaction. (medlineplus.gov)

This lack of reactive oxygen species causes the body to overcompensate by activating more immune cells and producing more immune proteins. (medlineplus.gov)

The precise mechanism of action of sulfasalazine and/or its metabolites has not been completely elucidated, though its antioxidant effects are well established and are probably due to its scavenging effects against reactive oxygen and nitrogen species (ROS and RNS), as well as metal chelating properties, in association to its inhibitory effects over neutrophil oxidative burst. (nih.gov)
Reactive oxygen species (ROS) have been shown to have tissue-damaging effects that underlie many disease complications, including those associated with diabetes, Parkinson's, Alzheimer's, and atherosclerosis (Brownlee, 2005). (nih.gov)
What are the molecular mechanisms that moderate the differential effects of different biochemical species of dietary lipids, such as palmitate and linoleic acid, on tumor progression? (nih.gov)
We investigated the effects of Cd on the individual complexes of the electron transfer chain (ETC) and on the stimulation of reactive oxygen species (ROS) production in mitochondria. (cdc.gov)

Methionine-misacylation, then, may benefit the cell by protecting proteins from reactive oxygen species. (nih.gov)

As a result, phagocytes are unable to produce reactive oxygen species to kill foreign invaders and neutrophil activity is not regulated. (medlineplus.gov)

Anatomy32

Organisms8

Diseases8

Chemicals and Drugs137

Analytical, Diagnostic and Therapeutic Techniques and Equipment17

Phenomena and Processes51

Information Science1

Health Care1

Reactive oxygen intermediate-dependent NF-kappaB activation by interleukin-1beta requires 5-lipoxygenase or NADPH oxidase activity. (1/16336)

Hyperoxia induces the neuronal differentiated phenotype of PC12 cells via a sustained activity of mitogen-activated protein kinase induced by Bcl-2. (2/16336)

The Pseudomonas aeruginosa secretory product pyocyanin inactivates alpha1 protease inhibitor: implications for the pathogenesis of cystic fibrosis lung disease. (3/16336)

Inflammatory cell-mediated tumour progression and minisatellite mutation correlate with the decrease of antioxidative enzymes in murine fibrosarcoma cells. (4/16336)

Reactive oxygen species play an important role in the activation of heat shock factor 1 in ischemic-reperfused heart. (5/16336)

Methemoglobin formation by hydroxylamine metabolites of sulfamethoxazole and dapsone: implications for differences in adverse drug reactions. (6/16336)

Mechanisms and mediators in coal dust induced toxicity: a review. (7/16336)

1,25-Dihydroxyvitamin D3 enhances the susceptibility of breast cancer cells to doxorubicin-induced oxidative damage. (8/16336)

No images available that match "reactive oxygen species"

Reactive Oxygen Species

Oxygen

Oxidative Stress

Hydrogen Peroxide

Antioxidants

NADPH Oxidase

Free Radical Scavengers

Mitochondria

Oxygen Consumption

Superoxide Dismutase

Oxidation-Reduction

Catalase

Acetylcysteine

Superoxides

Oxidants

Apoptosis

Membrane Potential, Mitochondrial

Glutathione

Cells, Cultured

Signal Transduction

Lipid Peroxidation

Onium Compounds

Reactive Nitrogen Species

Singlet Oxygen

Xanthine Oxidase

Cyclic N-Oxides

Cell Survival

Cell Death

Free Radicals

Hydroxyl Radical

Nitric Oxide

Enzyme Activation

Cell Line, Tumor

DNA Damage

Glutathione Peroxidase

Enzyme Inhibitors

Dose-Response Relationship, Drug

Rotenone

Rats, Sprague-Dawley

Cell Line

Mice, Inbred C57BL

Ascorbic Acid

Blotting, Western

1,2-Dihydroxybenzene-3,5-Disulfonic Acid Disodium Salt

Luminescent Measurements

Acetophenones

Respiratory Burst

Cytochromes c

Xanthine

Time Factors

Mitochondrial Proteins

Vitamin K 3

Oxygen Inhalation Therapy

Mitochondria, Heart

Anoxia

Caspase 3

Models, Biological

Electron Transport Complex I

Mice, Knockout

Peroxiredoxins

Metalloporphyrins

Cell Hypoxia

Caspases

Neutrophils

Endothelium, Vascular

Protein Carbonylation

Deoxyguanosine

Cell Respiration

Electron Transport

NF-E2-Related Factor 2

Spin Labels

Paraquat

Rats, Wistar

Malondialdehyde

NF-kappa B

Phosphorylation

RNA, Messenger

Up-Regulation

DNA Fragmentation

NADH, NADPH Oxidoreductases