A potent mutagen and carcinogen. It is a public health concern because of its possible effects on industrial workers, as an environmental pollutant, an as a component of tobacco smoke.
A group of condensed ring hydrocarbons.
7,8,8a,9a-Tetrahydrobenzo(10,11)chryseno (3,4-b)oxirene-7,8-diol. A benzopyrene derivative with carcinogenic and mutagenic activity.
A class of chemicals that contain an anthracene ring with a naphthalene ring attached to it.
Benzopyrenes saturated in any two adjacent positions and substituted with two hydroxyl groups in any position. The majority of these compounds have carcinogenic or mutagenic activity.
A drug-metabolizing, cytochrome P-448 (P-450) enzyme which catalyzes the hydroxylation of benzopyrene to 3-hydroxybenzopyrene in the presence of reduced flavoprotein and molecular oxygen. Also acts on certain anthracene derivatives. An aspect of EC 1.14.14.1.
A major group of unsaturated cyclic hydrocarbons containing two or more rings. The vast number of compounds of this important group, derived chiefly from petroleum and coal tar, are rather highly reactive and chemically versatile. The name is due to the strong and not unpleasant odor characteristic of most substances of this nature. (From Hawley's Condensed Chemical Dictionary, 12th ed, p96)
The products of chemical reactions that result in the addition of extraneous chemical groups to DNA.
Compounds consisting of two or more fused ring structures.
Substances that increase the risk of NEOPLASMS in humans or animals. Both genotoxic chemicals, which affect DNA directly, and nongenotoxic chemicals, which induce neoplasms by other mechanism, are included.
The chemical alteration of an exogenous substance by or in a biological system. The alteration may inactivate the compound or it may result in the production of an active metabolite of an inactive parent compound. The alterations may be divided into METABOLIC DETOXICATION, PHASE I and METABOLIC DETOXICATION, PHASE II.
Chemical agents that increase the rate of genetic mutation by interfering with the function of nucleic acids. A clastogen is a specific mutagen that causes breaks in chromosomes.
Organic compounds that include a cyclic ether with three ring atoms in their structure. They are commonly used as precursors for POLYMERS such as EPOXY RESINS.
A carcinogen that is often used in experimental cancer studies.
Four fused benzyl rings with three linear and one angular, that can be viewed as a benzyl-phenanthrenes. Compare with NAPHTHACENES which are four linear rings.
Tests of chemical substances and physical agents for mutagenic potential. They include microbial, insect, mammalian cell, and whole animal tests.
A liver microsomal cytochrome P-450 monooxygenase capable of biotransforming xenobiotics such as polycyclic hydrocarbons and halogenated aromatic hydrocarbons into carcinogenic or mutagenic compounds. They have been found in mammals and fish. This enzyme, encoded by CYP1A1 gene, can be measured by using ethoxyresorufin as a substrate for the ethoxyresorufin O-deethylase activity.
A by-product of the destructive distillation of coal used as a topical antieczematic. It is an antipruritic and keratoplastic agent used also in the treatment of psoriasis and other skin conditions. Occupational exposure to soots, tars, and certain mineral oils is known to be carcinogenic according to the Fourth Annual Report on Carcinogens (NTP 85-002, 1985) (Merck Index, 11th ed).
A generic grouping for dihydric alcohols with the hydroxy groups (-OH) located on different carbon atoms. They are viscous liquids with high boiling points for their molecular weights.
Organic compounds containing a BENZENE ring attached to a flavone group. Some of these are potent arylhydrocarbon hydroxylase inhibitors. They may also inhibit the binding of NUCLEIC ACIDS to BENZOPYRENES and related compounds. The designation includes all isomers; the 7,8-isomer is most frequently encountered.
A large group of cytochrome P-450 (heme-thiolate) monooxygenases that complex with NAD(P)H-FLAVIN OXIDOREDUCTASE in numerous mixed-function oxidations of aromatic compounds. They catalyze hydroxylation of a broad spectrum of substrates and are important in the metabolism of steroids, drugs, and toxins such as PHENOBARBITAL, carcinogens, and insecticides.
Carcinogenic substances that are found in the environment.
1,2-Benzphenanthrenes. POLYCYCLIC COMPOUNDS obtained from coal tar.
Agents that reduce the frequency or rate of spontaneous or induced mutations independently of the mechanism involved.
A superfamily of hundreds of closely related HEMEPROTEINS found throughout the phylogenetic spectrum, from animals, plants, fungi, to bacteria. They include numerous complex monooxygenases (MIXED FUNCTION OXYGENASES). In animals, these P-450 enzymes serve two major functions: (1) biosynthesis of steroids, fatty acids, and bile acids; (2) metabolism of endogenous and a wide variety of exogenous substrates, such as toxins and drugs (BIOTRANSFORMATION). They are classified, according to their sequence similarities rather than functions, into CYP gene families (>40% homology) and subfamilies (>59% homology). For example, enzymes from the CYP1, CYP2, and CYP3 gene families are responsible for most drug metabolism.
Phenanthrenes are aromatic hydrocarbons consisting of three benzene rings fused together in a linear arrangement, commonly found in various plants and some animals, and can act as precursors for certain steroid hormones or exhibit pharmacological activities with potential therapeutic uses.
The phenomenon whereby compounds whose molecules have the same number and kind of atoms and the same atomic arrangement, but differ in their spatial relationships. (From McGraw-Hill Dictionary of Scientific and Technical Terms, 5th ed)
Measurement of the intensity and quality of fluorescence.
A deoxyribonucleotide polymer that is the primary genetic material of all cells. Eukaryotic and prokaryotic organisms normally contain DNA in a double-stranded state, yet several important biological processes transiently involve single-stranded regions. DNA, which consists of a polysugar-phosphate backbone possessing projections of purines (adenine and guanine) and pyrimidines (thymine and cytosine), forms a double helix that is held together by hydrogen bonds between these purines and pyrimidines (adenine to thymine and guanine to cytosine).
Elimination of ENVIRONMENTAL POLLUTANTS; PESTICIDES and other waste using living organisms, usually involving intervention of environmental or sanitation engineers.
A greasy substance with a smoky odor and burned taste created by high temperature treatment of BEECH and other WOOD; COAL TAR; or resin of the CREOSOTE BUSH. It contains CRESOLS and POLYCYCLIC AROMATIC HYDROCARBONS which are CARCINOGENS. It has been widely used as wood preservative and in PESTICIDES and had former use medicinally in DISINFECTANTS; LAXATIVES; and DERMATOLOGIC AGENTS.
A potent epoxide hydrase and aryl hydrocarbon hydroxylase inhibitor. It enhances the tumor-initiating ability of certain carcinogens.
A polyaromatic hydrocarbon inducer of P4501A1 and P4501A2 cytochromes. (Proc Soc Exp Biol Med 1994 Dec:207(3):302-308)
Industrial chemicals which have become widespread environmental pollutants. Each aroclor is a mixture of chlorinated biphenyls (1200 series) or chlorinated terphenyls (5400 series) or a combination of both (4400 series).
Enzymes that catalyze reversibly the formation of an epoxide or arene oxide from a glycol or aromatic diol, respectively.
Cytoplasmic proteins that bind certain aryl hydrocarbons, translocate to the nucleus, and activate transcription of particular DNA segments. AH receptors are identified by their high-affinity binding to several carcinogenic or teratogenic environmental chemicals including polycyclic aromatic hydrocarbons found in cigarette smoke and smog, heterocyclic amines found in cooked foods, and halogenated hydrocarbons including dioxins and polychlorinated biphenyls. No endogenous ligand has been identified, but an unknown natural messenger with a role in cell differentiation and development is suspected.
A circumscribed benign epithelial tumor projecting from the surrounding surface; more precisely, a benign epithelial neoplasm consisting of villous or arborescent outgrowths of fibrovascular stroma covered by neoplastic cells. (Stedman, 25th ed)
An increase in the rate of synthesis of an enzyme due to the presence of an inducer which acts to derepress the gene responsible for enzyme synthesis.
Experimentally induced new abnormal growth of TISSUES in animals to provide models for studying human neoplasms.
Compounds of the general formula R-O-R arranged in a ring or crown formation.
A group of compounds that are derivatives of methoxybenzene and contain the general formula R-C7H7O.
Reduction of pharmacologic activity or toxicity of a drug or other foreign substance by a living system, usually by enzymatic action. It includes those metabolic transformations that make the substance more soluble for faster renal excretion.
A residue of coal, left after dry (destructive) distillation, used as a fuel.
The combination of two or more different factors in the production of cancer.
A nucleoside consisting of the base guanine and the sugar deoxyribose.
Substances which pollute the soil. Use for soil pollutants in general or for which there is no specific heading.
Substances or energies, for example heat or light, which when introduced into the air, water, or land threaten life or health of individuals or ECOSYSTEMS.
Mixture of 2- and 3-tert-butyl-4-methoxyphenols that is used as an antioxidant in foods, cosmetics, and pharmaceuticals.
A chemical by-product that results from burning or incinerating chlorinated industrial chemicals and other hydrocarbons. This compound is considered an environmental toxin, and may pose reproductive, as well as, other health risks for animals and humans.
The rate dynamics in chemical or physical systems.
A family of diphenylenemethane derivatives.
Products of the hydrolysis of chlorophylls in which the phytic acid side chain has been removed and the carboxylic acids saponified.
A hepatic carcinogen whose mechanism of activation involves N-hydroxylation to the aryl hydroxamic acid followed by enzymatic sulfonation to sulfoxyfluorenylacetamide. It is used to study the carcinogenicity and mutagenicity of aromatic amines.
7,12-Dimethylbenzanthracene. Polycyclic aromatic hydrocarbon found in tobacco smoke that is a potent carcinogen.
Benzene derivatives that include one or more hydroxyl groups attached to the ring structure.
Agents that emit light after excitation by light. The wave length of the emitted light is usually longer than that of the incident light. Fluorochromes are substances that cause fluorescence in other substances, i.e., dyes used to mark or label other compounds with fluorescent tags.
Widely distributed enzymes that carry out oxidation-reduction reactions in which one atom of the oxygen molecule is incorporated into the organic substrate; the other oxygen atom is reduced and combined with hydrogen ions to form water. They are also known as monooxygenases or hydroxylases. These reactions require two substrates as reductants for each of the two oxygen atoms. There are different classes of monooxygenases depending on the type of hydrogen-providing cosubstrate (COENZYMES) required in the mixed-function oxidation.
Family of small, surface-dwelling fish that inhabit fresh and brackish waters, and coastal marine areas.
A large lobed glandular organ in the abdomen of vertebrates that is responsible for detoxification, metabolism, synthesis and storage of various substances.
Maleimides are a class of chemically reactive compounds containing a maleimide functional group, which can undergo addition reactions with nucleophiles such as thiols, making them useful for the formation of covalent bonds in various bioconjugation and material synthesis applications.
The relationship between the chemical structure of a compound and its biological or pharmacological activity. Compounds are often classed together because they have structural characteristics in common including shape, size, stereochemical arrangement, and distribution of functional groups.
A serotype of Salmonella enterica that is a frequent agent of Salmonella gastroenteritis in humans. It also causes PARATYPHOID FEVER.
Chemical compounds which pollute the water of rivers, streams, lakes, the sea, reservoirs, or other bodies of water.
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.
Artifactual vesicles formed from the endoplasmic reticulum when cells are disrupted. They are isolated by differential centrifugation and are composed of three structural features: rough vesicles, smooth vesicles, and ribosomes. Numerous enzyme activities are associated with the microsomal fraction. (Glick, Glossary of Biochemistry and Molecular Biology, 1990; from Rieger et al., Glossary of Genetics: Classical and Molecular, 5th ed)
Naturally occurring complex liquid hydrocarbons which, after distillation, yield combustible fuels, petrochemicals, and lubricants.
A subfamily in the family MURIDAE, comprising the hamsters. Four of the more common genera are Cricetus, CRICETULUS; MESOCRICETUS; and PHODOPUS.
'Smoke' is a complex mixture of gases, fine particles, and volatile compounds, generally produced by combustion of organic substances, which can contain harmful chemicals known to have adverse health effects.
A genus of gram-positive, aerobic bacteria. Most species are free-living in soil and water, but the major habitat for some is the diseased tissue of warm-blooded hosts.
A barbituric acid derivative that acts as a nonselective central nervous system depressant. It potentiates GAMMA-AMINOBUTYRIC ACID action on GABA-A RECEPTORS, and modulates chloride currents through receptor channels. It also inhibits glutamate induced depolarizations.
Either of the pair of organs occupying the cavity of the thorax that effect the aeration of the blood.
A group of guanine ribonucleotides in which the phosphate residues of each guanine ribonucleotide act as bridges in forming diester linkages between the ribose moieties.

Platelet high affinity low density lipoprotein binding and import of lipoprotein derived phospholipids. (1/624)

The binding of low density lipoprotein (LDL) to the platelet cell membrane could facilitate the transfer of phospholipids from LDL to the platelets. A polyclonal antibody against the platelet glycoproteins IIb/IIIa inhibited the high affinity binding of 125I-LDL by up to 80%. The transfer of pyrene (py)-labeled sphingomyelin (SM), phosphatidylcholine and phosphatidylethanolamine from LDL to the platelets was unaffected by the antibody. The lectin wheat germ agglutinin (WGA) reduced the binding of 125I-LDL to the platelets by approximately 80%. In contrast, the lectin stimulated the transfer of SM from LDL into the platelets by about three-fold. WGA also specifically augmented the transfer of py-SM between lipid vesicles and the platelets, the stimulation being abolished in the presence of N-acetylglucosamine. Dextran sulfate (DS) increased the specific binding of 125I-LDL to the platelets by up to 2.8-fold. On the other hand, the import of LDL-derived py-phospholipids was unaffected by DS. Together, the results indicate that the phospholipid transfer from LDL to the platelets is independent of the high affinity LDL binding to the platelets and is specifically stimulated by WGA. Thus, the interactions of platelets with LDL phospholipids differ markedly from those with the apoprotein components of the lipoproteins.  (+info)

Characterization of mannooligosaccharide caps in mycobacterial lipoarabinomannan by capillary electrophoresis/electrospray mass spectrometry. (2/624)

A new analytical approach based on capillary electrophoresis-electrospray mass spectrometry (CE/ESI-MS) has provided new insight into the characterization of mannooligosaccharide caps from lipoarabinomannans (LAMs), which are key molecules in the immunopathogenesis of tuberculosis. This analytical approach requires oligosaccharide labeling with the fluorophore 1-aminopyrene-3,6,8-trisulfonate (APTS) by reductive amination at the reducing termini. Optimization of the separation and ionization conditions, such as the choice of capillary electrophoresis (CE) electrolyte buffers, is presented and discussed. Anionic separation of the mono and oligosaccharide APTS derivatives was finally achieved with aqueous triethylammonium formate buffer. It was found that in contrast to the triethylammonium phosphate buffer, the triethylammonium formate buffer was appropriate for CE/ESI-MS coupling analysis of APTS-carbohydrate derivatives. In this case, negative ESI-mass spectra of APTS-carbohydrate adducts showed mainly (M-2H)2-pseudomolecular ions and some sequence fragment ions allowing their non-ambiguous structural characterization at the picomolar level. This analytical approach was successfully applied to more complex mixtures of carbohydrates released by mild acid hydrolysis of the lipoarabinomannans from Mycobacterium bovis BCG. The APTS-mannooligosaccharide cap adducts were separated by CE and their structural characterization achieved by CE/ESI-MS analyses. Mannooligosaccharide caps were routinely analyzed by capillary electrophoresis-laser induced fluorescence (CE-LIF) from 50 fmol of lipoarabinomannans with mannosyl capping (ManLAMs) but sensitivity was about 50 times lower using ESI-MS detection.  (+info)

HPLC/fluorescence determination of anti-BPDE-DNA adducts in mononuclear white blood cells from PAH-exposed humans. (3/624)

The aim of this study was to compare (+/-)-r-7,t-8-dihydroxy-t-9,10-oxy-7,8,9,10-tetrahydrobenzo[a]pyrene (anti-BPDE)-DNA adduct levels in groups of humans subjected to various levels of polycyclic aromatic hydrocarbon (PAH) (benzo[a]pyrene) exposure. An HPLC/fluorescence method was applied to detect specifically anti-BPDE-DNA adducts in mononuclear white blood cells [lymphocyte plus monocyte fraction (LMF)] from humans exposed to PAHs. A total of 130 subjects comprised the sample population: 26 psoriatic patients (3 days after clinical coal tar treatment of the skin), 15 coke oven workers, 19 chimney sweeps, 36 aluminium anode plant workers and 34 non-occupationally PAH-exposed subjects (controls). PAH exposure was assessed in each group by means of the urinary excretion of 1-pyrenol (mean group levels: 1.2, 0.7, 0.3, 65.0 and 0.1 micromol/mol creatinine in coke oven workers, chimney sweeps, aluminium plant anode workers, psoriatic patients and non-occupationally PAH-exposed subjects, respectively). HPLC/fluorescence analysis of BPDE-DNA adducts showed that the percentage of subjects with adduct levels exceeding the 95 percentile control subject value (8.9 adducts/10(8) nucleotides) was significantly high in coke oven workers (46.7%) and chimney sweeps (21.0%) (chi2 test, P < 0.01 and P < 0.05, respectively) but not in aluminium plant workers (11.1%) and psoriatic patients (0%). The increase in BPDE-DNA adduct levels in LMF (Ln values) was significantly related to chronic inhalatory and high PAH exposure (linear multiple regression analysis, F = 6.37, P < 0.01; t = 4.2, P < 0.001). Skin acute (or short-term) and high PAH exposure, charcoal-grilled meat consumption and smoking habit did not seem to influence BPDE-DNA adduct formation in LMF.  (+info)

Comparative metabolism of 1-, 2-, and 4-nitropyrene by human hepatic and pulmonary microsomes. (4/624)

Determining the capability of humans to metabolize the mononitropyrene (mono-NP) isomers 1-, 2-, and 4-NP and understanding which human cytochrome P450 (P450) enzymes are involved in their activation and/or detoxification is important in the assessment of individual susceptibility to these environmental carcinogens. We compared the ability of 15 human hepatic and 8 pulmonary microsomal samples to metabolize each of the three isomers. Human hepatic microsomes were competent in metabolizing all three isomers. Qualitatively similar metabolic patterns were observed, although at much lower levels, upon incubating mono-NP with pulmonary microsomes. Ring-oxidized metabolites (phenols and trans-dihydrodiols) were produced from all three isomers. However, the nitroreductive metabolism leading to the formation of aminopyrene was evident only with 4-NP. The role of specific P450 enzymes in the human hepatic microsomal metabolism of mono-NP was investigated by correlating the P450-dependent catalytic activities in each microsomal sample with the levels of individual metabolites formed by the same microsomes and by examining the effects of agents that can either inhibit or stimulate specific P450 enzymes in mono-NP metabolism. On the basis of these studies, we attribute most of the hepatic microsomal metabolism of 1- and 4-NP to P450 3A4, although a minor role for P450 1A2 cannot be ruled out. Specifically, P450 3A4 was responsible for the formation of 3-hydroxy-1nitropyrene from 1-NP and the formation of trans-9,10-dihydro-9,10dihydroxy-4-nitropyrene, 9(10)-hydroxy-4-nitropyrene, and 4-aminopyrene from 4-NP. None of the P450 enzymes examined (P450s 3A4, 1A2, 2E1, 2A6, 2D6, and 2C9) appeared to be involved in catalyzing the formation of trans-4,5-dihydro-4,5-dihydroxy-2-nitropyrene and 6-hydroxy-2-nitropyrene from 2-NP in human hepatic microsomes. These results, the first report on the comparative metabolism of mono-NP in humans, clearly demonstrate that the role of specific human P450 enzymes in catalyzing oxidative and reductive pathways of mono-NP is dependent upon the position of the nitro group.  (+info)

Genotoxic exposures of potroom workers. (5/624)

OBJECTIVES: Potroom workers in aluminum reduction plants have increased risks for bladder and lung cancer due to exposure from polycyclic aromatic hydrocarbons (PAH). In this study correlations between measures of the external, internal, and biological effective dose have been studied for PAH. METHODS: Venous blood samples were obtained from 98 male potroom workers and 55 unexposed male blue-collar workers, for the analysis of aromatic adducts to DNA (deoxyribonucleic acid) in lymphocytes, using the 32P-postlabeling technique. 1-Hydroxypyrene in urine was analyzed with high-pressure liquid chromatography. Personal sampling of both particulate and gas phase PAH was performed during a full workday for the potroom workers and for 5 referents. Individual PAH congeners were determined with liquid chromatographic-mass spectrometric and gas chromatographic-mass spectrometric techniques. RESULTS: The respiratory-zone airborne level of the sum of 22 particulate (median 13.2 micro/m3) and the 7 gas phase PAH-congeners (median 16.3 microg/m3) among the potroom workers was a hundred times higher than among the referents. The urinary concentration of 1-hydroxypyrene before work was 30 times higher for the potroom workers (median 3.43 micromol/mol creatinine) than for the referents. Most airborne PAH congeners correlated with the excretion of 1-hydroxypyrene in urine. The frequency of aromatic DNA adducts did not, however, differ between the potroom workers and the referents, and no correlation was found for 1-hydroxypyrene in urine. CONCLUSIONS: Despite an obvious occupational exposure to PAH, no increase in aromatic DNA adducts in lymphocytes was found among the potroom workers.  (+info)

Molecular mechanisms of peptide loading by the tumor rejection antigen/heat shock chaperone gp96 (GRP94). (6/624)

Complexes of gp96/GRP94 and peptides have been shown to elicit immunogenicity. We used fluorescence to understand peptide association with gp96. A pyrene-peptide conjugate was complexed with gp96 under a variety of conditions. At room temperature in low salt (20 mM NaCl), the peptide binds gp96 with a strong affinity (approximately 100-150 nM) and forms pyrene excimers, suggesting that the peptides were assembled as dimers. In high salt (2.2 M NaCl), although peptide binding was stronger (Ka approximately 55 nM) than in low salt, pyrene excimers were absent, implying that peptides were farther apart in the complex. Heat shock-activated peptide binding exhibited characteristics of both low salt and high salt modes of binding. Anisotropy and average lifetime of the bound pyrene suggested that peptides were probably located in a solvent-accessible hydrophobic binding pocket in low salt, whereas in high salt, the peptide may be buried in a less hydrophobic (more hydrophilic) environment. These results suggested that peptide-gp96 complexes were assembled in several different ways, depending on the assembly conditions. Resonance energy transfer between the intrinsic tryptophan(s) in gp96 and pyrene suggested that one or more tryptophan residues were within the critical Forster distance of 27-30 A from the pyrene in the bound peptide. It is proposed that peptides are assembled within higher order gp96 complexes (dimers, etc.) in a hydrophobic pocket and that there may be a conformational change in gp96 leading to an open configuration for peptide loading.  (+info)

Pathologic changes induced in respiratory tract mucosa by polycyclic hydrocarbons of differing carcinogenic activity. (7/624)

Seven aromatic polycyclic hydrocarbons (PCHs) were investigated for their toxic effects on respiratory mucosa: benzo(e)pyrene (BeP), pyrene, anthracene, benz(a)anthracene(BaA), dibenz(a,c)anthracene(DBacA), benzo (a)pyrene (BaP), and dimethylbenz(a)anthracene (DMBA). The compounds were chosen because they comprise a spectrum of PCHs ranging from noncarcinogens, to initiators, to weak and strong carcinogens. All of them except DMBA are environmentally relevant chemicals. The chemicals were tested over an 8-week period. Heterotopic tracheal transplants were continously exposed and the histopathologic effects induced by the various PCHs were periodically assessed semiquantitatively. All PCHs exhibited varying degrees of toxicity for respiratory epithelium and submucosa. BeP clearly showed the least toxicity followed by pyrene and anthracene. BaA and DBacA caused marked epithelial and submucosal changes. In addition to epithelial hyperplasia, undifferentiated epithelium and squamous metaplasia developed. Marked mononuclear infiltration occurred in the subepithelial connective tissue. With BaP the epithelial and submucosal changes were similar but were much stronger. DMBA was the most toxic substance, causing epithelial necrosis followed by generalized keratinizing squamous metaplasia; the subepithelial changes consisted of an early acellular exudate and, later (at 8 weeks), marked condensation and hyalinization of the lamina propria. The toxic response pattern of the tracheal mucosa to carcinogenic agents was characterized by the chronicity of epithelial and connective tissue damage, as opposed to the short-lived hyperplastic and inflammatory response elicited by the noncarcinogens and weak initiators.  (+info)

2'-Pyrene modified oligonucleotide provides a highly sensitive fluorescent probe of RNA. (8/624)

Oligonucleotide 9mers containing 2'-O-(1-pyrenylmethyl)uridine [U(pyr)] at the center position were synthesized by using a protected U(pyr) phosphoramidite. The UV melting behaviors indicate that the pyrene-modified oligonucleotides can bind to both their complementary DNA and RNA in aqueous solution. When compared with the unmodified oligonucleotides, the pyrene-modified oligonucleotides showed higher affinity for DNA while exhibiting lower affinity for RNA. The pyrene-modified oligonucleotides in diluted solution exhibited fluorescence typical of pyrene monomer emission [lambdamax 378 (band I) and 391 nm (band III)]. When these oligomers bound to DNA, the fluorescence intensity ratio of band III/band I was increased. With this fluorescence change, a new broad emission (lambdamax 450 nm) due to exciplex between the pyrene and an adjacent nucleobase appeared. In contrast, addition of RNA to the pyrene oligonucleotides resulted in enhancement of the pyrene monomer emission with decrease in the fluorescence band ratio. The extent of the emission enhancement was found to be highly dependent on the nucleobase adjacent to the U(pyr) in the pyrene oligomers. The pyrene oligonucleotide containing dC at the 3'-site of the modification showed remarkable increase (approximately 250 times) in fluorescence (375 nm) upon binding to complementary RNA. The present findings would open the way to the design of a highly sensitive fluorescent probe of RNA.  (+info)

I'm sorry for any confusion, but "Pyrenes" is not a medical term. It is a term used in chemistry and materials science, referring to a type of aromatic hydrocarbon molecule that consists of two benzene rings fused together. If you have a different term or concept in mind, please provide it so I can give you an accurate definition or information.

Benzopyrene is a chemical compound that belongs to the class of polycyclic aromatic hydrocarbons (PAHs). It is formed from the incomplete combustion of organic materials, such as tobacco, coal, and gasoline. Benzopyrene is a potent carcinogen, meaning it has the ability to cause cancer in living tissue.

Benzopyrene is able to induce genetic mutations by interacting with DNA and forming bulky adducts that interfere with normal DNA replication. This can lead to the development of various types of cancer, including lung, skin, and bladder cancer. Benzopyrene has also been linked to an increased risk of developing cardiovascular disease.

In the medical field, benzopyrene is often used as a model compound for studying the mechanisms of chemical carcinogenesis. It is also used in research to investigate the effects of PAHs on human health and to develop strategies for reducing exposure to these harmful substances.

Dihydroxydihydrobenzopyrenes are chemical compounds that are produced when benzo[a]pyrene, a polycyclic aromatic hydrocarbon (PAH), is metabolically activated in the body. Benzo[a]pyrene is found in tobacco smoke and is formed during the incomplete combustion of organic materials such as coal, oil, gasoline, wood, and garbage.

When benzo[a]pyrene is metabolized by enzymes in the liver, it is converted into several different forms, including dihydrodiols and dihydroxydihydrobenzopyrenes. These compounds are more reactive than benzo[a]pyrene itself and can bind to DNA, forming DNA adducts that may contribute to the development of cancer.

Dihydroxydihydrobenzopyrenes have been studied for their potential role in tobacco-related cancers such as lung cancer, and they are considered to be biomarkers of exposure to benzo[a]pyrene and other PAHs. However, more research is needed to fully understand the health effects of these compounds and their role in the development of disease.

Benzopyrene hydroxylase is an enzyme that is involved in the metabolism and detoxification of polycyclic aromatic hydrocarbons (PAHs), which are a group of environmental pollutants found in cigarette smoke, air pollution, and charred or overcooked foods. Benzopyrene hydroxylase is primarily found in the liver and is responsible for adding a hydroxyl group to benzopyrene, a type of PAH, making it more water-soluble and easier to excrete from the body. This enzyme plays an important role in the body's defense against the harmful effects of PAHs.

Polycyclic aromatic hydrocarbons (PAHs) are a group of organic compounds characterized by the presence of two or more fused benzene rings. They are called "polycyclic" because they contain multiple cyclic structures, and "aromatic" because these structures contain alternating double bonds that give them distinctive chemical properties and a characteristic smell.

PAHs can be produced from both natural and anthropogenic sources. Natural sources include wildfires, volcanic eruptions, and the decomposition of organic matter. Anthropogenic sources include the incomplete combustion of fossil fuels, such as coal, oil, and gasoline, as well as tobacco smoke, grilled foods, and certain industrial processes.

PAHs are known to be environmental pollutants and can have harmful effects on human health. They have been linked to an increased risk of cancer, particularly lung, skin, and bladder cancers, as well as reproductive and developmental toxicity. PAHs can also cause skin irritation, respiratory problems, and damage to the immune system.

PAHs are found in a variety of environmental media, including air, water, soil, and food. They can accumulate in the food chain, particularly in fatty tissues, and have been detected in a wide range of foods, including meat, fish, dairy products, and vegetables. Exposure to PAHs can occur through inhalation, ingestion, or skin contact.

It is important to limit exposure to PAHs by avoiding tobacco smoke, reducing consumption of grilled and smoked foods, using ventilation when cooking, and following safety guidelines when working with industrial processes that produce PAHs.

DNA adducts are chemical modifications or alterations that occur when DNA molecules become attached to or bound with certain harmful substances, such as toxic chemicals or carcinogens. These attachments can disrupt the normal structure and function of the DNA, potentially leading to mutations, genetic damage, and an increased risk of cancer and other diseases.

DNA adducts are formed when a reactive molecule from a chemical agent binds covalently to a base in the DNA molecule. This process can occur either spontaneously or as a result of exposure to environmental toxins, such as those found in tobacco smoke, certain industrial chemicals, and some medications.

The formation of DNA adducts is often used as a biomarker for exposure to harmful substances, as well as an indicator of potential health risks associated with that exposure. Researchers can measure the levels of specific DNA adducts in biological samples, such as blood or urine, to assess the extent and duration of exposure to certain chemicals or toxins.

It's important to note that not all DNA adducts are necessarily harmful, and some may even play a role in normal cellular processes. However, high levels of certain DNA adducts have been linked to an increased risk of cancer and other diseases, making them a focus of ongoing research and investigation.

Medical definitions typically focus on the relevance of a term to medicine or healthcare, so here's a medical perspective on polycyclic compounds:

Polycyclic compounds are organic substances that contain two or more chemical rings in their structure. While not all polycyclic compounds are relevant to medicine, some can have significant medical implications. For instance, polycyclic aromatic hydrocarbons (PAHs) are a type of polycyclic compound that can be found in tobacco smoke and certain types of air pollution. PAHs have been linked to an increased risk of cancer, particularly lung cancer, due to their ability to damage DNA.

Another example is the class of drugs called steroids, which include hormones like cortisol and sex hormones like testosterone and estrogen. These compounds are polycyclic because they contain several interconnected rings in their structure. Steroid medications are used to treat a variety of medical conditions, including inflammation, asthma, and Addison's disease.

In summary, while not all polycyclic compounds are relevant to medicine, some can have important medical implications, either as harmful environmental pollutants or as useful therapeutic agents.

Carcinogens are agents (substances or mixtures of substances) that can cause cancer. They may be naturally occurring or man-made. Carcinogens can increase the risk of cancer by altering cellular DNA, disrupting cellular function, or promoting cell growth. Examples of carcinogens include certain chemicals found in tobacco smoke, asbestos, UV radiation from the sun, and some viruses.

It's important to note that not all exposures to carcinogens will result in cancer, and the risk typically depends on factors such as the level and duration of exposure, individual genetic susceptibility, and lifestyle choices. The International Agency for Research on Cancer (IARC) classifies carcinogens into different groups based on the strength of evidence linking them to cancer:

Group 1: Carcinogenic to humans
Group 2A: Probably carcinogenic to humans
Group 2B: Possibly carcinogenic to humans
Group 3: Not classifiable as to its carcinogenicity to humans
Group 4: Probably not carcinogenic to humans

This information is based on medical research and may be subject to change as new studies become available. Always consult a healthcare professional for medical advice.

Biotransformation is the metabolic modification of a chemical compound, typically a xenobiotic (a foreign chemical substance found within an living organism), by a biological system. This process often involves enzymatic conversion of the parent compound to one or more metabolites, which may be more or less active, toxic, or mutagenic than the original substance.

In the context of pharmacology and toxicology, biotransformation is an important aspect of drug metabolism and elimination from the body. The liver is the primary site of biotransformation, but other organs such as the kidneys, lungs, and gastrointestinal tract can also play a role.

Biotransformation can occur in two phases: phase I reactions involve functionalization of the parent compound through oxidation, reduction, or hydrolysis, while phase II reactions involve conjugation of the metabolite with endogenous molecules such as glucuronic acid, sulfate, or acetate to increase its water solubility and facilitate excretion.

Mutagens are physical or chemical agents that can cause permanent changes in the structure of genetic material, including DNA and chromosomes, leading to mutations. These mutations can be passed down to future generations and may increase the risk of cancer and other diseases. Examples of mutagens include ultraviolet (UV) radiation, tobacco smoke, and certain chemicals found in industrial settings. It is important to note that not all mutations are harmful, but some can have negative effects on health and development.

Epoxy compounds, also known as epoxy resins, are a type of thermosetting polymer characterized by the presence of epoxide groups in their molecular structure. An epoxide group is a chemical functional group consisting of an oxygen atom double-bonded to a carbon atom, which is itself bonded to another carbon atom.

Epoxy compounds are typically produced by reacting a mixture of epichlorohydrin and bisphenol-A or other similar chemicals under specific conditions. The resulting product is a two-part system consisting of a resin and a hardener, which must be mixed together before use.

Once the two parts are combined, a chemical reaction takes place that causes the mixture to cure or harden into a solid material. This curing process can be accelerated by heat, and once fully cured, epoxy compounds form a strong, durable, and chemically resistant material that is widely used in various industrial and commercial applications.

In the medical field, epoxy compounds are sometimes used as dental restorative materials or as adhesives for bonding medical devices or prosthetics. However, it's important to note that some people may have allergic reactions to certain components of epoxy compounds, so their use must be carefully evaluated and monitored in a medical context.

Methylcholanthrene is a polycyclic aromatic hydrocarbon that is used in research to induce skin tumors in mice. It is a potent carcinogen and mutagen, and exposure to it can increase the risk of cancer in humans. It is not typically found in medical treatments or therapies.

Mutagenicity tests are a type of laboratory assays used to identify agents that can cause genetic mutations. These tests detect changes in the DNA of organisms, such as bacteria, yeast, or mammalian cells, after exposure to potential mutagens. The most commonly used mutagenicity test is the Ames test, which uses a strain of Salmonella bacteria that is sensitive to mutagens. If a chemical causes an increase in the number of revertants (reversion to the wild type) in the bacterial population, it is considered to be a mutagen. Other tests include the mouse lymphoma assay and the chromosomal aberration test. These tests are used to evaluate the potential genotoxicity of chemicals and are an important part of the safety evaluation process for new drugs, chemicals, and other substances.

Cytochrome P-450 CYP1A1 is an enzyme that is part of the cytochrome P450 family, which are a group of enzymes involved in the metabolism of drugs and other xenobiotics (foreign substances) in the body. Specifically, CYP1A1 is found primarily in the liver and lungs and plays a role in the metabolism of polycyclic aromatic hydrocarbons (PAHs), which are chemicals found in tobacco smoke and are produced by the burning of fossil fuels and other organic materials.

CYP1A1 also has the ability to activate certain procarcinogens, which are substances that can be converted into cancer-causing agents (carcinogens) within the body. Therefore, variations in the CYP1A1 gene may influence an individual's susceptibility to cancer and other diseases.

The term "P-450" refers to the fact that these enzymes absorb light at a wavelength of 450 nanometers when they are combined with carbon monoxide, giving them a characteristic pink color. The "CYP" stands for "cytochrome P," and the number and letter designations (e.g., 1A1) indicate the specific enzyme within the family.

Coal tar is a thick, dark liquid that is a byproduct of coal manufacturing processes, specifically the distillation of coal at high temperatures. It is a complex mixture of hundreds of different compounds, including polycyclic aromatic hydrocarbons (PAHs), which are known to be carcinogenic.

In medical terms, coal tar has been used topically for various skin conditions such as psoriasis, eczema, and seborrheic dermatitis due to its anti-inflammatory and keratolytic properties. Coal tar can help reduce scaling, itching, and inflammation of the skin. However, its use is limited due to potential side effects such as skin irritation, increased sun sensitivity, and potential risk of cancer with long-term use. Coal tar products should be used under the guidance of a healthcare provider and according to the instructions on the label.

Glycols are a type of organic compound that contain two hydroxyl (OH) groups attached to adjacent carbon atoms. They are colorless, odorless, and have a sweet taste. The most common glycols are ethylene glycol and propylene glycol. Ethylene glycol is widely used as an automotive antifreeze and in the manufacture of polyester fibers and resins, while propylene glycol is used as a food additive, in pharmaceuticals, and as a solvent in various industries. Glycols are also used as a coolant, humectant, and in the production of unsaturated polyester resins. Exposure to high levels of glycols can cause irritation to the eyes, skin, and respiratory tract, and ingestion can be harmful or fatal.

Benzoflavones are a type of chemical compound that consist of a benzene ring (a basic unit of organic chemistry made up of six carbon atoms arranged in a flat, hexagonal shape) fused to a flavone structure. Flavones are a type of flavonoid, which is a class of plant pigments widely present in fruits and vegetables. Benzoflavones have been studied for their potential medicinal properties, including anti-inflammatory, antioxidant, and anticancer activities. However, more research is needed to fully understand their effects and safety profile in humans.

Aryl hydrocarbon hydroxylases (AHH) are a group of enzymes that play a crucial role in the metabolism of various aromatic and heterocyclic compounds, including potentially harmful substances such as polycyclic aromatic hydrocarbons (PAHs) and dioxins. These enzymes are primarily located in the endoplasmic reticulum of cells, particularly in the liver, but can also be found in other tissues.

The AHH enzymes catalyze the addition of a hydroxyl group (-OH) to the aromatic ring structure of these compounds, which is the first step in their biotransformation and eventual elimination from the body. This process can sometimes lead to the formation of metabolites that are more reactive and potentially toxic than the original compound. Therefore, the overall impact of AHH enzymes on human health is complex and depends on various factors, including the specific compounds being metabolized and individual genetic differences in enzyme activity.

Carcinogens are agents that can cause cancer. According to the National Institute of Environmental Health Sciences (NIEHS), environmental carcinogens refer to "cancer-causing agents that people encounter in their daily lives, including substances or exposures in air, water, food, and in the workplace." These carcinogens can increase the risk of cancer by damaging DNA or interfering with cellular processes that control growth.

Examples of environmental carcinogens include:

* Air pollution: Certain pollutants in the air, such as diesel exhaust particles and secondhand smoke, have been linked to an increased risk of lung cancer.
* Radon: A naturally occurring radioactive gas that can accumulate in homes and other buildings, radon is the second leading cause of lung cancer in the United States.
* UV radiation: Exposure to ultraviolet (UV) radiation from the sun or tanning beds can lead to skin cancer.
* Certain chemicals: Some chemicals found in the workplace or in consumer products, such as asbestos, benzene, and vinyl chloride, have been linked to an increased risk of cancer.
* Infectious agents: Certain viruses, bacteria, and parasites can increase the risk of cancer. For example, human papillomavirus (HPV) is a major cause of cervical cancer, and hepatitis B and C viruses are leading causes of liver cancer.

It's important to note that exposure to environmental carcinogens does not guarantee that a person will develop cancer. The risk depends on many factors, including the level and duration of exposure, as well as individual susceptibility. However, reducing exposure to these agents can help reduce the overall risk of cancer.

Chrysenes are a group of polycyclic aromatic hydrocarbons (PAHs) that are found in the environment as a result of both natural processes and human activities such as combustion of fossil fuels, waste incineration, and cigarette smoke. They consist of four fused benzene rings and are highly stable, making them persistent in the environment. Chrysenes have been shown to have potential toxic, mutagenic, and carcinogenic effects on living organisms, including humans. They can accumulate in the food chain and pose a risk to human health through exposure via contaminated air, water, and food.

Antimutagenic agents are substances that prevent or reduce the frequency of mutations in DNA, which can be caused by various factors such as radiation, chemicals, and free radicals. These agents work by preventing the formation of mutations or by repairing the damage already done to the DNA. They can be found naturally in foods, such as antioxidants, or they can be synthesized in a laboratory. Antimutagenic agents have potential use in cancer prevention and treatment, as well as in reducing the negative effects of environmental mutagens.

The Cytochrome P-450 (CYP450) enzyme system is a group of enzymes found primarily in the liver, but also in other organs such as the intestines, lungs, and skin. These enzymes play a crucial role in the metabolism and biotransformation of various substances, including drugs, environmental toxins, and endogenous compounds like hormones and fatty acids.

The name "Cytochrome P-450" refers to the unique property of these enzymes to bind to carbon monoxide (CO) and form a complex that absorbs light at a wavelength of 450 nm, which can be detected spectrophotometrically.

The CYP450 enzyme system is involved in Phase I metabolism of xenobiotics, where it catalyzes oxidation reactions such as hydroxylation, dealkylation, and epoxidation. These reactions introduce functional groups into the substrate molecule, which can then undergo further modifications by other enzymes during Phase II metabolism.

There are several families and subfamilies of CYP450 enzymes, each with distinct substrate specificities and functions. Some of the most important CYP450 enzymes include:

1. CYP3A4: This is the most abundant CYP450 enzyme in the human liver and is involved in the metabolism of approximately 50% of all drugs. It also metabolizes various endogenous compounds like steroids, bile acids, and vitamin D.
2. CYP2D6: This enzyme is responsible for the metabolism of many psychotropic drugs, including antidepressants, antipsychotics, and beta-blockers. It also metabolizes some endogenous compounds like dopamine and serotonin.
3. CYP2C9: This enzyme plays a significant role in the metabolism of warfarin, phenytoin, and nonsteroidal anti-inflammatory drugs (NSAIDs).
4. CYP2C19: This enzyme is involved in the metabolism of proton pump inhibitors, antidepressants, and clopidogrel.
5. CYP2E1: This enzyme metabolizes various xenobiotics like alcohol, acetaminophen, and carbon tetrachloride, as well as some endogenous compounds like fatty acids and prostaglandins.

Genetic polymorphisms in CYP450 enzymes can significantly affect drug metabolism and response, leading to interindividual variability in drug efficacy and toxicity. Understanding the role of CYP450 enzymes in drug metabolism is crucial for optimizing pharmacotherapy and minimizing adverse effects.

Phenanthrenes are not typically defined in a medical context, but they are a class of organic compounds that have a polycyclic aromatic hydrocarbon structure consisting of three benzene rings fused together. They can be found in some natural products and have been studied for their potential pharmacological properties. Some phenanthrenes have shown anti-inflammatory, antioxidant, and cytotoxic activities, among others. However, more research is needed to fully understand their therapeutic potential and safety profile.

Stereoisomerism is a type of isomerism (structural arrangement of atoms) in which molecules have the same molecular formula and sequence of bonded atoms, but differ in the three-dimensional orientation of their atoms in space. This occurs when the molecule contains asymmetric carbon atoms or other rigid structures that prevent free rotation, leading to distinct spatial arrangements of groups of atoms around a central point. Stereoisomers can have different chemical and physical properties, such as optical activity, boiling points, and reactivities, due to differences in their shape and the way they interact with other molecules.

There are two main types of stereoisomerism: enantiomers (mirror-image isomers) and diastereomers (non-mirror-image isomers). Enantiomers are pairs of stereoisomers that are mirror images of each other, but cannot be superimposed on one another. Diastereomers, on the other hand, are non-mirror-image stereoisomers that have different physical and chemical properties.

Stereoisomerism is an important concept in chemistry and biology, as it can affect the biological activity of molecules, such as drugs and natural products. For example, some enantiomers of a drug may be active, while others are inactive or even toxic. Therefore, understanding stereoisomerism is crucial for designing and synthesizing effective and safe drugs.

Fluorescence spectrometry is a type of analytical technique used to investigate the fluorescent properties of a sample. It involves the measurement of the intensity of light emitted by a substance when it absorbs light at a specific wavelength and then re-emits it at a longer wavelength. This process, known as fluorescence, occurs because the absorbed energy excites electrons in the molecules of the substance to higher energy states, and when these electrons return to their ground state, they release the excess energy as light.

Fluorescence spectrometry typically measures the emission spectrum of a sample, which is a plot of the intensity of emitted light versus the wavelength of emission. This technique can be used to identify and quantify the presence of specific fluorescent molecules in a sample, as well as to study their photophysical properties.

Fluorescence spectrometry has many applications in fields such as biochemistry, environmental science, and materials science. For example, it can be used to detect and measure the concentration of pollutants in water samples, to analyze the composition of complex biological mixtures, or to study the properties of fluorescent nanomaterials.

Deoxyribonucleic acid (DNA) is the genetic material present in the cells of organisms where it is responsible for the storage and transmission of hereditary information. DNA is a long molecule that consists of two strands coiled together to form a double helix. Each strand is made up of a series of four nucleotide bases - adenine (A), guanine (G), cytosine (C), and thymine (T) - that are linked together by phosphate and sugar groups. The sequence of these bases along the length of the molecule encodes genetic information, with A always pairing with T and C always pairing with G. This base-pairing allows for the replication and transcription of DNA, which are essential processes in the functioning and reproduction of all living organisms.

Environmental biodegradation is the breakdown of materials, especially man-made substances such as plastics and industrial chemicals, by microorganisms such as bacteria and fungi in order to use them as a source of energy or nutrients. This process occurs naturally in the environment and helps to break down organic matter into simpler compounds that can be more easily absorbed and assimilated by living organisms.

Biodegradation in the environment is influenced by various factors, including the chemical composition of the substance being degraded, the environmental conditions (such as temperature, moisture, and pH), and the type and abundance of microorganisms present. Some substances are more easily biodegraded than others, and some may even be resistant to biodegradation altogether.

Biodegradation is an important process for maintaining the health and balance of ecosystems, as it helps to prevent the accumulation of harmful substances in the environment. However, some man-made substances, such as certain types of plastics and industrial chemicals, may persist in the environment for long periods of time due to their resistance to biodegradation, leading to negative impacts on wildlife and ecosystems.

In recent years, there has been increasing interest in developing biodegradable materials that can break down more easily in the environment as a way to reduce waste and minimize environmental harm. These efforts have led to the development of various biodegradable plastics, coatings, and other materials that are designed to degrade under specific environmental conditions.

Creosote is a thick, dark brown or black liquid that has a strong, tarry odor and is produced when wood, coal, or other organic materials are burned or distilled. It is a complex mixture of chemicals, including polycyclic aromatic hydrocarbons (PAHs), which have been linked to an increased risk of cancer.

In the medical context, creosote is not typically used as a treatment for any condition. However, it has been used historically as a topical antiseptic and wound dressing, due to its antibacterial properties. However, its use in this way has largely been replaced by more modern and effective treatments.

It's important to note that creosote is considered a hazardous substance and can be harmful if swallowed, inhaled, or comes into contact with the skin. It can cause irritation to the eyes, skin, and respiratory tract, and prolonged exposure has been linked to an increased risk of cancer. Therefore, it should be handled with care and used only under the supervision of a medical professional.

Trichloroepoxypropane (TCP) is not typically considered a medical term, but it is a chemical compound that can have potential health impacts. Therefore, I will provide you with a general definition and some information related to its potential health effects.

Trichloroepoxypropane is an organochlorine compound with the formula Cl3C-C-CO-. It is a colorless liquid with a chloroform-like odor. TCP is primarily used as an intermediate in the production of other chemicals, such as flame retardants and plastic additives.

In terms of potential health effects, exposure to Trichloroepoxypropane can occur through inhalation, skin contact, or ingestion. It can cause irritation to the eyes, skin, and respiratory tract. Chronic exposure may lead to more severe health issues, including damage to the liver and kidneys, as well as potential neurological effects. However, it is important to note that Trichloroepoxypropane is not typically encountered in a medical setting, and its health impacts are generally studied within the context of occupational or environmental exposure.

If you have concerns about exposure to this chemical or any other potentially harmful substances, consult with a healthcare professional or poison control center for advice tailored to your specific situation.

Beta-Naphthoflavone is a type of compound known as an aromatic hydrocarbon receptor (AHR) agonist. It is often used in research to study the effects of AHR activation on various biological processes, including the regulation of gene expression and the development of certain diseases such as cancer.

In the medical field, beta-Naphthoflavone may be used in experimental settings to investigate its potential as a therapeutic agent or as a tool for understanding the mechanisms underlying AHR-mediated diseases. However, it is not currently approved for use as a medication in humans.

Aroclors are a series of polychlorinated biphenyl (PCB) mixtures that were manufactured by the Monsanto Company. They were widely used as cooling and insulating fluids in electrical equipment, such as transformers and capacitors, due to their non-flammability, chemical stability, and electrical insulating properties.

The term "Aroclor" is followed by a four-digit number that indicates the specific mixture and its average degree of chlorination. For example, Aroclor 1242 contains approximately 42% chlorine by weight, while Aroclor 1260 contains approximately 60% chlorine by weight.

Because of their persistence in the environment and potential toxicity to humans and wildlife, the production and use of PCBs, including Aroclors, were banned in the United States in 1979 under the Toxic Substances Control Act. However, due to their widespread historical use, PCBs continue to be a significant environmental pollutant and can still be found in many older electrical equipment, building materials, and soil and water samples.

Epoxide hydrolases are a group of enzymes that catalyze the hydrolysis of epoxides, which are molecules containing a three-membered ring consisting of two carbon atoms and one oxygen atom. This reaction results in the formation of diols, which are molecules containing two hydroxyl groups (-OH).

Epoxide hydrolases play an important role in the detoxification of xenobiotics (foreign substances) and the metabolism of endogenous compounds. They help to convert toxic epoxides into less harmful products, which can then be excreted from the body.

There are two main types of epoxide hydrolases: microsomal epoxide hydrolase (mEH) and soluble epoxide hydrolase (sEH). mEH is primarily responsible for metabolizing xenobiotics, while sEH plays a role in the metabolism of endogenous compounds such as arachidonic acid.

Impaired function or inhibition of epoxide hydrolases has been linked to various diseases, including cancer, cardiovascular disease, and neurological disorders. Therefore, these enzymes are considered important targets for the development of drugs and therapies aimed at treating these conditions.

Aryl hydrocarbon receptors (AhRs) are a type of intracellular receptor that play a crucial role in the response to environmental contaminants and other xenobiotic compounds. They are primarily found in the cytoplasm of cells, where they bind to aromatic hydrocarbons, including polycyclic aromatic hydrocarbons (PAHs) and polychlorinated biphenyls (PCBs), which are common environmental pollutants.

Once activated by ligand binding, AhRs translocate to the nucleus, where they dimerize with the AhR nuclear translocator (ARNT) protein and bind to specific DNA sequences called xenobiotic response elements (XREs). This complex then regulates the expression of a variety of genes involved in xenobiotic metabolism, including those encoding cytochrome P450 enzymes.

In addition to their role in xenobiotic metabolism, AhRs have been implicated in various physiological processes, such as immune response, cell differentiation, and development. Dysregulation of AhR signaling has been associated with the pathogenesis of several diseases, including cancer, autoimmune disorders, and neurodevelopmental disorders.

Therefore, understanding the mechanisms of AhR activation and regulation is essential for developing strategies to prevent or treat environmental toxicant-induced diseases and other conditions linked to AhR dysfunction.

A papilloma is a benign (noncancerous) tumor that grows on a stalk, often appearing as a small cauliflower-like growth. It can develop in various parts of the body, but when it occurs in the mucous membranes lining the respiratory, digestive, or genitourinary tracts, they are called squamous papillomas. The most common type is the skin papilloma, which includes warts. They are usually caused by human papillomavirus (HPV) infection and can be removed through various medical procedures if they become problematic or unsightly.

Enzyme induction is a process by which the activity or expression of an enzyme is increased in response to some stimulus, such as a drug, hormone, or other environmental factor. This can occur through several mechanisms, including increasing the transcription of the enzyme's gene, stabilizing the mRNA that encodes the enzyme, or increasing the translation of the mRNA into protein.

In some cases, enzyme induction can be a beneficial process, such as when it helps the body to metabolize and clear drugs more quickly. However, in other cases, enzyme induction can have negative consequences, such as when it leads to the increased metabolism of important endogenous compounds or the activation of harmful procarcinogens.

Enzyme induction is an important concept in pharmacology and toxicology, as it can affect the efficacy and safety of drugs and other xenobiotics. It is also relevant to the study of drug interactions, as the induction of one enzyme by a drug can lead to altered metabolism and effects of another drug that is metabolized by the same enzyme.

Experimental neoplasms refer to abnormal growths or tumors that are induced and studied in a controlled laboratory setting, typically in animals or cell cultures. These studies are conducted to understand the fundamental mechanisms of cancer development, progression, and potential treatment strategies. By manipulating various factors such as genetic mutations, environmental exposures, and pharmacological interventions, researchers can gain valuable insights into the complex processes underlying neoplasm formation and identify novel targets for cancer therapy. It is important to note that experimental neoplasms may not always accurately represent human cancers, and further research is needed to translate these findings into clinically relevant applications.

Cyclic ethers are a type of organic compound that contain an ether functional group (-O-) within a cyclic (ring-shaped) structure. In a cyclic ether, one or more oxygen atoms are part of the ring, which can consist of various numbers of carbon atoms. The simplest example of a cyclic ether is oxirane, also known as ethylene oxide, which contains a three-membered ring with two carbon atoms and one oxygen atom.

Cyclic ethers have diverse applications in the chemical industry, including their use as building blocks for the synthesis of other chemicals, pharmaceuticals, and materials. Some cyclic ethers, like tetrahydrofuran (THF), are common solvents due to their ability to dissolve a wide range of organic compounds. However, some cyclic ethers can be hazardous or toxic, so they must be handled with care during laboratory work and industrial processes.

Anisoles are organic compounds that consist of a phenyl ring (a benzene ring with a hydroxyl group replaced by a hydrogen atom) attached to a methoxy group (-O-CH3). The molecular formula for anisole is C6H5OCH3. Anisoles are aromatic ethers and can be found in various natural sources, including anise plants and some essential oils. They have a wide range of applications, including as solvents, flavoring agents, and intermediates in the synthesis of other chemicals.

Metabolic detoxification, in the context of drugs, refers to the series of biochemical processes that the body undergoes to transform drugs or other xenobiotics into water-soluble compounds so they can be excreted. This process typically involves two phases:

1. Phase I Detoxification: In this phase, enzymes such as cytochrome P450 oxidases introduce functional groups into the drug molecule, making it more polar and reactive. This can result in the formation of metabolites that are less active than the parent compound or, in some cases, more toxic.

2. Phase II Detoxification: In this phase, enzymes such as glutathione S-transferases, UDP-glucuronosyltransferases, and sulfotransferases conjugate these polar and reactive metabolites with endogenous molecules like glutathione, glucuronic acid, or sulfate. This further increases the water solubility of the compound, allowing it to be excreted by the kidneys or bile.

It's important to note that while these processes are essential for eliminating drugs and other harmful substances from the body, they can also produce reactive metabolites that may cause damage to cells and tissues if not properly regulated. Therefore, maintaining a balance in the activity of these detoxification enzymes is crucial for overall health and well-being.

'Coke' is a term that can have different meanings depending on the context. In the medical field, coke most commonly refers to a solid form of carbon or a type of char produced by heating coal or other organic materials in the absence of air. This form of carbon is relatively pure and low in impurities, making it useful for various industrial applications, including the production of steel and aluminum.

However, 'coke' can also refer to a street name for cocaine, which is a highly addictive stimulant drug derived from the leaves of the coca plant. It is important to note that this usage of the term 'coke' is more commonly associated with illicit drug use and addiction rather than medical terminology.

Therefore, when using the term 'coke' in a medical context, it is essential to clarify its meaning to avoid any confusion or misunderstandings.

Cocarcinogenesis is a term used in the field of oncology to describe a process where exposure to certain chemicals or physical agents enhances the tumor-forming ability of a cancer-causing agent (carcinogen). A cocarcinogen does not have the ability to initiate cancer on its own, but it can promote the development and progression of cancer when combined with a carcinogen.

In other words, a cocarcinogen is a substance or factor that acts synergistically with a known carcinogen to increase the likelihood or speed up the development of cancer. This process can occur through various mechanisms, such as suppressing the immune system, promoting inflammation, increasing cell proliferation, or inhibiting apoptosis (programmed cell death).

Examples of cocarcinogens include tobacco smoke, alcohol, certain viruses, and radiation. These agents can interact with carcinogens to increase the risk of cancer in individuals who are exposed to them. It is important to note that while cocarcinogens themselves may not directly cause cancer, they can significantly contribute to its development and progression when combined with other harmful substances or factors.

Deoxyguanosine is a chemical compound that is a component of DNA (deoxyribonucleic acid), one of the nucleic acids. It is a nucleoside, which is a molecule consisting of a sugar (in this case, deoxyribose) and a nitrogenous base (in this case, guanine). Deoxyguanosine plays a crucial role in the structure and function of DNA, as it pairs with deoxycytidine through hydrogen bonding to form a rung in the DNA double helix. It is involved in the storage and transmission of genetic information.

I'm sorry for any confusion, but "soil pollutants" is not a term typically used in medical definitions. Soil pollution refers to the presence or accumulation of hazardous substances, chemicals, or other pollutants in soil that can have negative effects on plant life, human health, and the environment.

However, if you're asking about potential health effects of exposure to soil pollutants, it could include a variety of symptoms or diseases, depending on the specific pollutant. For example, exposure to lead-contaminated soil can lead to developmental delays in children, while exposure to certain pesticides or industrial chemicals can cause neurological problems, respiratory issues, and even cancer.

If you have more specific information about a particular substance or context, I may be able to provide a more precise answer.

Environmental pollutants are defined as any substances or energy (such as noise, heat, or light) that are present in the environment and can cause harm or discomfort to humans or other living organisms, or damage the natural ecosystems. These pollutants can come from a variety of sources, including industrial processes, transportation, agriculture, and household activities. They can be in the form of gases, liquids, solids, or radioactive materials, and can contaminate air, water, and soil. Examples include heavy metals, pesticides, volatile organic compounds (VOCs), particulate matter, and greenhouse gases.

It is important to note that the impact of environmental pollutants on human health and the environment can be acute (short-term) or chronic (long-term) and it depends on the type, concentration, duration and frequency of exposure. Some common effects of environmental pollutants include respiratory problems, cancer, neurological disorders, reproductive issues, and developmental delays in children.

It is important to monitor, control and reduce the emissions of these pollutants through regulations, technology advancements, and sustainable practices to protect human health and the environment.

Butylated hydroxyanisole (BHA) is a synthetic antioxidant that is commonly used as a food additive to prevent or slow down the oxidation of fats, oils, and other lipids. This helps to maintain the quality, stability, and safety of food products by preventing rancidity and off-flavors. BHA is also used in cosmetics, pharmaceuticals, and animal feeds for similar purposes.

In medical terms, BHA is classified as a chemical preservative and antioxidant. It is a white or creamy white crystalline powder that is soluble in alcohol and ether but insoluble in water. BHA is often used in combination with other antioxidants, such as butylated hydroxytoluene (BHT), to provide a synergistic effect and enhance the overall stability of food products.

While BHA is generally recognized as safe by regulatory agencies such as the U.S. Food and Drug Administration (FDA) and the European Food Safety Authority (EFSA), some studies have suggested that high doses of BHA may have potential health risks, including possible carcinogenic effects. However, these findings are not conclusive, and further research is needed to fully understand the potential health impacts of BHA exposure.

Tetrachlorodibenzodioxin (TCDD) is not a common medical term, but it is known in toxicology and environmental health. TCDD is the most toxic and studied compound among a group of chemicals known as dioxins.

Medical-related definition:

Tetrachlorodibenzodioxin (TCDD) is an unintended byproduct of various industrial processes, including waste incineration, chemical manufacturing, and pulp and paper bleaching. It is a highly persistent environmental pollutant that accumulates in the food chain, primarily in animal fat. Human exposure to TCDD mainly occurs through consumption of contaminated food, such as meat, dairy products, and fish. TCDD is a potent toxicant with various health effects, including immunotoxicity, reproductive and developmental toxicity, and carcinogenicity. The severity of these effects depends on the level and duration of exposure.

In the context of medicine and pharmacology, "kinetics" refers to the study of how a drug moves throughout the body, including its absorption, distribution, metabolism, and excretion (often abbreviated as ADME). This field is called "pharmacokinetics."

1. Absorption: This is the process of a drug moving from its site of administration into the bloodstream. Factors such as the route of administration (e.g., oral, intravenous, etc.), formulation, and individual physiological differences can affect absorption.

2. Distribution: Once a drug is in the bloodstream, it gets distributed throughout the body to various tissues and organs. This process is influenced by factors like blood flow, protein binding, and lipid solubility of the drug.

3. Metabolism: Drugs are often chemically modified in the body, typically in the liver, through processes known as metabolism. These changes can lead to the formation of active or inactive metabolites, which may then be further distributed, excreted, or undergo additional metabolic transformations.

4. Excretion: This is the process by which drugs and their metabolites are eliminated from the body, primarily through the kidneys (urine) and the liver (bile).

Understanding the kinetics of a drug is crucial for determining its optimal dosing regimen, potential interactions with other medications or foods, and any necessary adjustments for special populations like pediatric or geriatric patients, or those with impaired renal or hepatic function.

I believe there may be some confusion in your question. "Fluorenes" is not a medical term, but rather a chemical term referring to organic compounds that contain a fluorene moiety, which is a bicyclic compound made up of two benzene rings fused to a five-membered ring containing two carbon atoms and one double bond.

Fluorenes have various applications in the field of materials science, including organic light-emitting diodes (OLEDs), organic photovoltaics (OPVs), and organic field-effect transistors (OFETs). They are not typically used in a medical context, although some fluorene derivatives have been explored for potential therapeutic applications.

Therefore, I cannot provide a medical definition of "Fluorenes." However, if you have any questions about the chemical properties or applications of fluorenes, I would be happy to try and answer them.

Chlorophyllides are the breakdown products of chlorophyll, which is the green pigment found in plants and algae that is essential for photosynthesis. Chlorophyllides are formed when chlorophyll is broken down by enzymes or through other chemical processes. They differ from chlorophyll in that they lack a phytol tail, which is a long hydrocarbon chain that is attached to the chlorophyll molecule.

Chlorophyllides have been studied for their potential health benefits, as they are thought to have antioxidant and anti-inflammatory properties. Some research has suggested that chlorophyllides may help protect against certain types of cancer, improve immune function, and reduce the risk of heart disease. However, more research is needed to confirm these potential benefits and to determine the optimal dosages and methods for consuming chlorophyllides.

It's worth noting that chlorophyllides are not typically found in significant quantities in the diet, as they are primarily produced during the breakdown of chlorophyll in plants. However, some supplements and green superfood powders may contain chlorophyllides or chlorophyllin, which is a semi-synthetic form of chlorophyll that is more stable and easier to absorb than natural chlorophyll.

2-Acetylaminofluorene (2-AAF) is a chemical compound that has been used in research to study the mechanisms of carcinogenesis. It is an aromatic amine and a derivative of fluorene, with the chemical formula C14H11NO.

2-AAF is not naturally occurring and is synthesized in the laboratory. It has been found to be carcinogenic in animal studies, causing tumors in various organs including the liver, lung, and bladder. The compound is metabolically activated in the body to form reactive intermediates that can bind to DNA and other cellular components, leading to mutations and cancer.

2-AAF has been used as a tool in research to investigate the mechanisms of chemical carcinogenesis and the role of metabolic activation in the process. It is not used in medical treatments or therapies.

9,10-Dimethyl-1,2-benzanthracene (DMBA) is a synthetic, aromatic hydrocarbon that is commonly used in research as a carcinogenic compound. It is a potent tumor initiator and has been widely used to study chemical carcinogenesis in laboratory animals.

DMBA is a polycyclic aromatic hydrocarbon (PAH) with two benzene rings fused together, and two methyl groups attached at the 9 and 10 positions. This structure allows DMBA to intercalate into DNA, causing mutations that can lead to cancer.

Exposure to DMBA has been shown to cause a variety of tumors in different organs, depending on the route of administration and dose. In animal models, DMBA is often applied to the skin or administered orally to induce tumors in the mammary glands, lungs, or digestive tract.

It's important to note that DMBA is not a natural compound found in the environment and is used primarily for research purposes only. It should be handled with care and appropriate safety precautions due to its carcinogenic properties.

Phenols, also known as phenolic acids or phenol derivatives, are a class of chemical compounds consisting of a hydroxyl group (-OH) attached to an aromatic hydrocarbon ring. In the context of medicine and biology, phenols are often referred to as a type of antioxidant that can be found in various foods and plants.

Phenols have the ability to neutralize free radicals, which are unstable molecules that can cause damage to cells and contribute to the development of chronic diseases such as cancer, heart disease, and neurodegenerative disorders. Some common examples of phenolic compounds include gallic acid, caffeic acid, ferulic acid, and ellagic acid, among many others.

Phenols can also have various pharmacological activities, including anti-inflammatory, antimicrobial, and analgesic effects. However, some phenolic compounds can also be toxic or irritating to the body in high concentrations, so their use as therapeutic agents must be carefully monitored and controlled.

Fluorescent dyes are substances that emit light upon excitation by absorbing light of a shorter wavelength. In a medical context, these dyes are often used in various diagnostic tests and procedures to highlight or mark certain structures or substances within the body. For example, fluorescent dyes may be used in imaging techniques such as fluorescence microscopy or fluorescence angiography to help visualize cells, tissues, or blood vessels. These dyes can also be used in flow cytometry to identify and sort specific types of cells. The choice of fluorescent dye depends on the specific application and the desired properties, such as excitation and emission spectra, quantum yield, and photostability.

Mixed Function Oxygenases (MFOs) are a type of enzyme that catalyze the addition of one atom each from molecular oxygen (O2) to a substrate, while reducing the other oxygen atom to water. These enzymes play a crucial role in the metabolism of various endogenous and exogenous compounds, including drugs, carcinogens, and environmental pollutants.

MFOs are primarily located in the endoplasmic reticulum of cells and consist of two subunits: a flavoprotein component that contains FAD or FMN as a cofactor, and an iron-containing heme protein. The most well-known example of MFO is cytochrome P450, which is involved in the oxidation of xenobiotics and endogenous compounds such as steroids, fatty acids, and vitamins.

MFOs can catalyze a variety of reactions, including hydroxylation, epoxidation, dealkylation, and deamination, among others. These reactions often lead to the activation or detoxification of xenobiotics, making MFOs an important component of the body's defense system against foreign substances. However, in some cases, these reactions can also produce reactive intermediates that may cause toxicity or contribute to the development of diseases such as cancer.

I apologize for any confusion, but "Fundulidae" is not a medical term. It is actually a family of fish that belongs to the order Cyprinodontiformes. Fundulidae includes killifishes, which are small, often colorful fish found in fresh and brackish waters of North and Central America.

The liver is a large, solid organ located in the upper right portion of the abdomen, beneath the diaphragm and above the stomach. It plays a vital role in several bodily functions, including:

1. Metabolism: The liver helps to metabolize carbohydrates, fats, and proteins from the food we eat into energy and nutrients that our bodies can use.
2. Detoxification: The liver detoxifies harmful substances in the body by breaking them down into less toxic forms or excreting them through bile.
3. Synthesis: The liver synthesizes important proteins, such as albumin and clotting factors, that are necessary for proper bodily function.
4. Storage: The liver stores glucose, vitamins, and minerals that can be released when the body needs them.
5. Bile production: The liver produces bile, a digestive juice that helps to break down fats in the small intestine.
6. Immune function: The liver plays a role in the immune system by filtering out bacteria and other harmful substances from the blood.

Overall, the liver is an essential organ that plays a critical role in maintaining overall health and well-being.

Maleimides are a class of chemical compounds that contain a maleimide functional group, which is characterized by a five-membered ring containing two carbon atoms and three nitrogen atoms. The double bond in the maleimide ring makes it highly reactive towards nucleophiles, particularly thiol groups found in cysteine residues of proteins.

In medical and biological contexts, maleimides are often used as cross-linking agents to modify or label proteins, peptides, and other biomolecules. For example, maleimide-functionalized probes such as fluorescent dyes, biotin, or radioisotopes can be covalently attached to thiol groups in proteins for various applications, including protein detection, purification, and imaging.

However, it is important to note that maleimides can also react with other nucleophiles such as amines, although at a slower rate. Therefore, careful control of reaction conditions is necessary to ensure specificity towards thiol groups.

A Structure-Activity Relationship (SAR) in the context of medicinal chemistry and pharmacology refers to the relationship between the chemical structure of a drug or molecule and its biological activity or effect on a target protein, cell, or organism. SAR studies aim to identify patterns and correlations between structural features of a compound and its ability to interact with a specific biological target, leading to a desired therapeutic response or undesired side effects.

By analyzing the SAR, researchers can optimize the chemical structure of lead compounds to enhance their potency, selectivity, safety, and pharmacokinetic properties, ultimately guiding the design and development of novel drugs with improved efficacy and reduced toxicity.

"Salmonella enterica" serovar "Typhimurium" is a subspecies of the bacterial species Salmonella enterica, which is a gram-negative, facultatively anaerobic, rod-shaped bacterium. It is a common cause of foodborne illness in humans and animals worldwide. The bacteria can be found in a variety of sources, including contaminated food and water, raw meat, poultry, eggs, and dairy products.

The infection caused by Salmonella Typhimurium is typically self-limiting and results in gastroenteritis, which is characterized by symptoms such as diarrhea, abdominal cramps, fever, and vomiting. However, in some cases, the infection can spread to other parts of the body and cause more severe illness, particularly in young children, older adults, and people with weakened immune systems.

Salmonella Typhimurium is a major public health concern due to its ability to cause outbreaks of foodborne illness, as well as its potential to develop antibiotic resistance. Proper food handling, preparation, and storage practices can help prevent the spread of Salmonella Typhimurium and other foodborne pathogens.

Chemical water pollutants refer to harmful chemicals or substances that contaminate bodies of water, making them unsafe for human use and harmful to aquatic life. These pollutants can come from various sources, including industrial and agricultural runoff, sewage and wastewater, oil spills, and improper disposal of hazardous materials.

Examples of chemical water pollutants include heavy metals (such as lead, mercury, and cadmium), pesticides and herbicides, volatile organic compounds (VOCs), polychlorinated biphenyls (PCBs), and petroleum products. These chemicals can have toxic effects on aquatic organisms, disrupt ecosystems, and pose risks to human health through exposure or consumption.

Regulations and standards are in place to monitor and limit the levels of chemical pollutants in water sources, with the aim of protecting public health and the environment.

DNA damage refers to any alteration in the structure or composition of deoxyribonucleic acid (DNA), which is the genetic material present in cells. DNA damage can result from various internal and external factors, including environmental exposures such as ultraviolet radiation, tobacco smoke, and certain chemicals, as well as normal cellular processes such as replication and oxidative metabolism.

Examples of DNA damage include base modifications, base deletions or insertions, single-strand breaks, double-strand breaks, and crosslinks between the two strands of the DNA helix. These types of damage can lead to mutations, genomic instability, and chromosomal aberrations, which can contribute to the development of diseases such as cancer, neurodegenerative disorders, and aging-related conditions.

The body has several mechanisms for repairing DNA damage, including base excision repair, nucleotide excision repair, mismatch repair, and double-strand break repair. However, if the damage is too extensive or the repair mechanisms are impaired, the cell may undergo apoptosis (programmed cell death) to prevent the propagation of potentially harmful mutations.

Microsomes are subcellular membranous vesicles that are obtained as a byproduct during the preparation of cellular homogenates. They are not naturally occurring structures within the cell, but rather formed due to fragmentation of the endoplasmic reticulum (ER) during laboratory procedures. Microsomes are widely used in various research and scientific studies, particularly in the fields of biochemistry and pharmacology.

Microsomes are rich in enzymes, including the cytochrome P450 system, which is involved in the metabolism of drugs, toxins, and other xenobiotics. These enzymes play a crucial role in detoxifying foreign substances and eliminating them from the body. As such, microsomes serve as an essential tool for studying drug metabolism, toxicity, and interactions, allowing researchers to better understand and predict the effects of various compounds on living organisms.

Petroleum is not a medical term, but it is a term used in the field of geology and petrochemicals. It refers to a naturally occurring liquid found in rock formations, which is composed of a complex mixture of hydrocarbons, organic compounds consisting primarily of carbon and hydrogen.

Petroleum is not typically associated with medical definitions; however, it's worth noting that petroleum and its derivatives are widely used in the production of various medical supplies, equipment, and pharmaceuticals. Some examples include plastic syringes, disposable gloves, catheters, lubricants for medical devices, and many active ingredients in medications.

In a broader sense, environmental or occupational exposure to petroleum and its byproducts could lead to health issues, but these are not typically covered under medical definitions of petroleum itself.

Cricetinae is a subfamily of rodents that includes hamsters, gerbils, and relatives. These small mammals are characterized by having short limbs, compact bodies, and cheek pouches for storing food. They are native to various parts of the world, particularly in Europe, Asia, and Africa. Some species are popular pets due to their small size, easy care, and friendly nature. In a medical context, understanding the biology and behavior of Cricetinae species can be important for individuals who keep them as pets or for researchers studying their physiology.

'Smoke' is not typically defined in a medical context, but it can be described as a mixture of small particles and gases that are released when something burns. Smoke can be composed of various components including carbon monoxide, particulate matter, volatile organic compounds (VOCs), benzene, toluene, styrene, and polycyclic aromatic hydrocarbons (PAHs). Exposure to smoke can cause a range of health problems, including respiratory symptoms, cardiovascular disease, and cancer.

In the medical field, exposure to smoke is often referred to as "secondhand smoke" or "passive smoking" when someone breathes in smoke from another person's cigarette, cigar, or pipe. This type of exposure can be just as harmful as smoking itself and has been linked to a range of health problems, including respiratory infections, asthma, lung cancer, and heart disease.

"Mycobacterium" is a genus of gram-positive, aerobic, rod-shaped bacteria that are characterized by their complex cell walls containing large amounts of lipids. This genus includes several species that are significant in human and animal health, most notably Mycobacterium tuberculosis, which causes tuberculosis, and Mycobacterium leprae, which causes leprosy. Other species of Mycobacterium can cause various diseases in humans, including skin and soft tissue infections, lung infections, and disseminated disease in immunocompromised individuals. These bacteria are often resistant to common disinfectants and antibiotics, making them difficult to treat.

Phenobarbital is a barbiturate medication that is primarily used for the treatment of seizures and convulsions. It works by suppressing the abnormal electrical activity in the brain that leads to seizures. In addition to its anticonvulsant properties, phenobarbital also has sedative and hypnotic effects, which can be useful for treating anxiety, insomnia, and agitation.

Phenobarbital is available in various forms, including tablets, capsules, and elixirs, and it is typically taken orally. The medication works by binding to specific receptors in the brain called gamma-aminobutyric acid (GABA) receptors, which help to regulate nerve impulses in the brain. By increasing the activity of GABA, phenobarbital can help to reduce excessive neural activity and prevent seizures.

While phenobarbital is an effective medication for treating seizures and other conditions, it can also be habit-forming and carries a risk of dependence and addiction. Long-term use of the medication can lead to tolerance, meaning that higher doses may be needed to achieve the same effects. Abruptly stopping the medication can also lead to withdrawal symptoms, such as anxiety, restlessness, and seizures.

Like all medications, phenobarbital can have side effects, including dizziness, drowsiness, and impaired coordination. It can also interact with other medications, such as certain antidepressants and sedatives, so it is important to inform your healthcare provider of all medications you are taking before starting phenobarbital.

In summary, phenobarbital is a barbiturate medication used primarily for the treatment of seizures and convulsions. It works by binding to GABA receptors in the brain and increasing their activity, which helps to reduce excessive neural activity and prevent seizures. While phenobarbital can be effective, it carries a risk of dependence and addiction and can have side effects and drug interactions.

A lung is a pair of spongy, elastic organs in the chest that work together to enable breathing. They are responsible for taking in oxygen and expelling carbon dioxide through the process of respiration. The left lung has two lobes, while the right lung has three lobes. The lungs are protected by the ribcage and are covered by a double-layered membrane called the pleura. The trachea divides into two bronchi, which further divide into smaller bronchioles, leading to millions of tiny air sacs called alveoli, where the exchange of gases occurs.

I'm sorry for any confusion, but "Poly G" does not have a specific medical definition. The term "poly" is a prefix in medicine that means many or multiple, and "G" could potentially refer to a variety of things (such as a genetic locus or a grade), but without more context it's impossible to provide an accurate medical definition for this term.

If you have a specific medical question or concern, I would be happy to try to help you with that. Please provide some additional context or clarify what you mean by "Poly G."

... was first isolated from coal tar, where it occurs up to 2% by weight. As a peri-fused PAH, pyrene is much more resonance ... Pyrene's fluorescence emission spectrum is very sensitive to solvent polarity, so pyrene has been used as a probe to determine ... Pyrene and its derivatives are used commercially to make dyes and dye precursors, for example pyranine and naphthalene-1,4,5,8- ... Pyrenes are strong electron donor materials and can be combined with several materials in order to make electron donor-acceptor ...
... Willan, 2001. Retrieved through: World Register of Marine Species on 29 January 2011. "Pyrene punctata". ... Pyrene punctata, common name : the telescoped dove shell, is a species of sea snail, a marine gastropod mollusk in the family ...
Pyrene may refer to: Pyrene, a chemical compound. Carbon tetrachloride, pyrene is the brand name used by the Pyrene ... Pyrene (mythology), consort of Ares and the mother of Cycnus in Greek mythology Pyrene, a Celtic city near the sources of the ... a noted former Pyrene Company factory in London, England in the Art Deco style Pyrene (gastropod), a genus of sea snails from ... Danube mentioned by Herodotus: see Heuneburg The Pyrene Company Limited, a manufacturer of firefighting equipment The Pyrene ...
Pyrene flava (Bruguière, 1789) Pyrene morrisoni Willan, 2001 Pyrene obscura (G.B. Sowerby I, 1844) Pyrene obtusa (G.B. Sowerby ... Species within the genus Pyrene include: Pyrene albinodulosa ogasawarana (Pilsbry, 1904-b) Pyrene aspersa (G.B. Sowerby I, 1844 ... Pyrene decussata (G.B. Sowerby I, 1844) Pyrene exima (Reeve, 1859 in 1843-65)[citation needed] Pyrene fasciata G.B. Sowerby I, ... Pyrene filmerae (G. B. Sowerby III, 1900): synonym of Pyrene flava filmerae (G. B. Sowerby III, 1900) Pyrene flavida (Lamarck, ...
... , the yellow orange tip, is a small butterfly of the family Pieridae, that is, the yellows and whites, which is ... "Ixias pyrene (Linnaeus, 1764)". Lepidoptera and Some Other Life Forms. Retrieved July 2, 2018. One or more of the preceding ... Wikispecies has information related to Ixias pyrene. Varshney, R.K.; Smetacek, Peter (2015). A Synoptic Catalogue of the ... List of butterflies of India (Pieridae) Wikimedia Commons has media related to Ixias pyrene. ...
"Pyrene obtusa obtusa". Gastropods.com. Retrieved 29 January 2011. Wikimedia Commons has media related to Pyrene obtusa. ( ... Pyrene obtusa is a species of sea snail, a marine gastropod mollusk in the family Columbellidae, the dove snails. The shell ... Pyrene obtusa. Retrieved through: World Register of Marine Species on 29 January 2011. Kiener (1840). General species and ...
In Greek mythology, Pyrene (Ancient Greek: Πυρήνη) may refer to: Pyrene, daughter of King Bebrycius and a lover (or victim, ... Pyrene, also called Pelopia, mother of Cycnus with Ares. Silius Italicus, Punica 3.415-446 Bell's New Pantheon Or Historical ...
Subspecies Pyrene flava filmerae (G. B. Sowerby III, 1900) Pyrene flava flava (Bruguière, 1789) The shell size varies between ... Pyrene flava, common name : the yellow dove shell, is a species of sea snail, a marine gastropod mollusk in the family ... "Pyrene flava". Gastropods.com. Retrieved 4 November 2010. Duclos, P.L. (1840). Histoire naturelle générale et particulière de ... Pyrene flava Bruguiere. Retrieved through: World Register of Marine Species on 4 November 2010. Dautzenberg, Ph. (1929). ...
Benzopyrene Benzo[a]pyrene Benzene Pyrene, a four-ring analogue "Benzo[e]pyrene (IARC Summary & Evaluation, Volume 32, 1983)". ... Benzo[e]pyrene is a polycyclic aromatic hydrocarbon with the chemical formula C20H12. It is listed as a Group 3 carcinogen by ...
Benzo[a]pyrene-7,8-dihydrodiol-9,10-epoxide is the carcinogenic product of three enzymatic reactions: Benzo[a]pyrene is first ... Benzopyrene Benzo[e]pyrene Pyrene, a four-ring analogue Toxification Henri A. Favre, Warren H. Powell (2013). Nomenclature of ... ISBN 978-1-4987-5429-3. "benzo[a]pyrene". pubchem.ncbi.nlm.nih.gov. "Assessment of Benzo-alpha-pyrene Emissions in the Great ... Benzo[a]pyrene (BaP or B[a]P) is a polycyclic aromatic hydrocarbon and the result of incomplete combustion of organic matter at ...
Pyrene was taken over by Chubb and Sons in 1967 and continued to operate under the name Pyrene Panorama. In 1971 Chubb Fire ... The Pyrene Manufacturing Company of Canada, the CO2 Equipment Company of Canada and the American Pyrene Company were all ... Pyrene Panorama Ltd was established in 1959 when Pyrene purchased the business of Panorama Equipment Ltd, which itself dated ... He established what became known as the Pyrene Company of Delaware in 1909. A British offshoot, The Pyrene Company Limited was ...
... pyrene and 2-fluoroindeno[1,2,3-cd]pyrene respectively. The reaction with indeno[1,2,3-cd]pyrene can be performed using NHO3 in ... One of these 16 is Indeno[1,2,3-cd]pyrene (IP). IP is the combination of an indeno molecule and a pyrene molecule with a ... "Indeno[1,2,3-cd]pyrene". PubChem. Minabe M, Shibuya N. Nitration of indeno[1,2,3-cd]pyrene and mutagenic activities of related ... 1983). Indeno(1,2,3-cd)pyrene. 32, 373 K Schirmer, A.G.J Chan, B.M Greenberg, D.G Dixon, N.C Bols. (1998). Ability of 16 ...
Benzo[a]pyrene is a derivative in which a fifth benzene ring has been fused to the pyrene system, and is a component of tobacco ... Benzo[a]pyrene-7,8-dihydrodiol-9,10-epoxide is a metabolite of benzo[a]pyrene formed by the introduction of vicinal hydroxyl ... Benzo[a]pyrene-7,8-dihydrodiol-9,10-epoxide has been shown to bind to an N2 atom of a guanine nucleobase in DNA, distorting the ... Benzo[a]pyrene-7,8-dihydrodiol-9,10-epoxide binds to the N2 atom of a guanine nucleobase in DNA, distorting the double helix ...
Pyrenes with thick walls. The generic name Lasianthus is derived from the Greek lasios, "shaggy, velvety, hairy", and anthos, " ...
Mineralizes phenanthrene, fluoranthene, and pyrene, but not anthracene or benzo[a]pyrene. Differential characteristics The ... Etymology: pyrenivorans; digesting pyrene. Microscopy Gram-positive, acid-fast rods. Colony characteristics The rough colonies ...
"Pyrene crash tenders". Flight. 2 September 1960. p. 84. (Use dmy dates from February 2018, Use British English from February ... From the late 1970s on they were replaced by vehicles like the Thornycroft Nubian Pyrene Mark 7. "Alvis FV-651 / FV-652 ... Fire fighting equipment was provided by The Pyrene Company Limited. It could produce 7,500 gallons of foam per minute and ... carried a crew of 6. 125 Salamanders were built and used by the Royal Air Force (as the Alvis Salamander/Pyrene Mark 6) and the ...
"Heuneburg - Celtic city of Pyrene". heuneburg-pyrene.de. "Heuneburg: Celtic town in Upper Swabia" (PDF). Krause, Dirk; ... "Heuneburg - Celtic city of Pyrene". heuneburg-pyrene.de. "Heuneburg". www.fuerstensitze.de. 6 May 2004. Retrieved 2021-11-23. " ... "Pyrene": "For the Ister flows from the land of the Celts and the city of Pyrene through the very middle of Europe..." Since the ... The settlement has been called "oldest city north of the alps", and has been identified with the Celtic city of Pyrene ...
"Pyrene Fire Extinguishers". Vintage Fire Extinguishers. Archived from the original on 25 March 2010. Retrieved 23 December 2009 ... the Pyrene Manufacturing Company of Delaware filed a patent to use carbon tetrachloride to extinguish fires. The liquid was ... Pyrene patented a small, portable extinguisher that used the chemical. The extinguisher consisted of a brass bottle with an ...
"Piquentum Wines". Les Caves de Pyrene. 2018-01-23. "The influence of yeasts type and malolactic fermentation on the quality of ...
Mistry, A. (31 May 2012). "Dehydration of 3,4-dihydro-5H-Benzo[cd]pyren-5-ol; 6H-Benzo[cd]pyrene". ChemSpider. Royal Society of ... The synthesis starts using a Wittig reaction of pyrene carboxaldehyde. To obtain the ylide needed, firstly triphenyl phosphine ... pyrenes". Chemistry: A European Journal. 21 (5): 2011-2018. doi:10.1002/chem.201404877. PMID 25469908. Palmer, J. (28 May 2012 ...
... degrades pyrene. Parte, A.C. "Bowmanella". LPSN. "Bowmanella pacifica Taxon Passport - StrainInfo". www. ... nov., isolated from a pyrene-degrading consortium". International Journal of Systematic and Evolutionary Microbiology. 59 (7): ...
Fruit is a globose drupe with 5 pyrenes. Source: Hindi - Nalbila Marathi - Ranabili, Gudmai Tamil - Puilipan cheddi, ...
Four higher annellated pyrenes with acene character". Journal of the Chemical Society (Resumed): 2681. doi:10.1039/JR9570002681 ...
pyrene as its sodium salt. Perylene in the form of its alkali metal (M = Li, Na, Cs) etherates. Cyclooctatetraene is reduced by ... Ease of formation is in the order benzene < naphthalene < anthracene < pyrene, etc. Salts of the radical anions are often not ... Kucera, Benjamin E.; Jilek, Robert E.; Brennessel, William W.; Ellis, John E. (2014). "Bis(pyrene)metal complexes of vanadium, ... niobium and titanium: Isolable homoleptic pyrene complexes of transition metals". Acta Crystallographica Section C: Structural ...
Hand propelled Pyrene fire extinguisher. Shand Mason horse-drawn fire engine. Shand Mason horse-drawn steam pump BOR 316 Dennis ...
In the 5th century BC the Greek historian Herodotus mentioned a Celtic city at the Danube - Pyrene, that historians attribute ... "Heuneburg - Celtic city of Pyrene". "Heuneburg (Herbertingen-Hundersingen)". Landeskunde Online. Retrieved 17 April 2020. ...
Klankeo, Piriya; Nopcharoenkul, Wannarak; Pinyakong, Onruthai (2009). "Two novel pyrene-degrading Diaphorobacter sp. and ...
Klankeo, Piriya; Nopcharoenkul, Wannarak; Pinyakong, Onruthai (2009). "Two novel pyrene-degrading Diaphorobacter sp. and ...
Theoretical and experimental studies on pyrene derivatives". Afterwards, she worked as a scientist at the European Synchrotron ...
nov., isolated from a pyrene-degrading consortium". International Journal of Systematic and Evolutionary Microbiology. 59 (7): ...
Pyrene was first isolated from coal tar, where it occurs up to 2% by weight. As a peri-fused PAH, pyrene is much more resonance ... Pyrenes fluorescence emission spectrum is very sensitive to solvent polarity, so pyrene has been used as a probe to determine ... Pyrene and its derivatives are used commercially to make dyes and dye precursors, for example pyranine and naphthalene-1,4,5,8- ... Pyrenes are strong electron donor materials and can be combined with several materials in order to make electron donor-acceptor ...
This kind of polythiophene/pyrene thin films showed to be a good matrix for the elaboration of fluorescent polymer composites. ... These compounds are highly emissive and easily form excimers as other high pyrene content polymers. The polymer emission can be ... The presence of aggregated graphene onto pyrene rich content areas by non-covalent interactions has been confirmed by AFM ... polymers demonstrated that the resulting films are made of homogeneous electroactive polythiophene with pendant pyrene units ...
... pyrene or its metabolite benzo [a] pyrene-7, 8-diol-9, 10-epoxide, using the comet assay. Mutagenesis, 25 (4). pp. 417-425. ... In vitro evaluation of baseline and induced DNA damage in human sperm exposed to benzo [a] pyrene or its metabolite benzo [a] ...
benzo(a)pyrene. Remarks:. with metabolic activation : 0.02 mg/ml Details on test system and experimental conditions:. METHOD OF ...
Microbial metabolism of pyrene. Chemical ± biological interactions 57, 203-216. *33. Sutherland JB. Detoxification of ... alkanes (C10, C14 to C18, C22, and C24), also pristane, hexadecane, phenanthrene, anthracene, fluoranthene, and pyrene. After ... Evaluation of dissipation mechanisms for benzo[a]pyrene in the rhizosphere of tall fescue. Journal of Environmental Quality. ...
URXP10 - 1-pyrene (ng/L). Variable Name: URXP10. SAS Label: 1-pyrene (ng/L). English Text: 1-pyrene (ng/L). Target: Both males ... URDP10LC - 1-pyrene comment code. Variable Name: URDP10LC. SAS Label: 1-pyrene comment code. English Text: 1-pyrene comment ...
pyrene.. Not classifiable as to their carcinogenicity to humans. U.S. Environmental Protection Agency (EPA). *benz(a)anthracene ...
LR: 20151119; JID: 8800805; 0 (Biomarkers); 0 (Nitrosamines); 0 (Pyrenes); 3417WMA06D (Benzo(a)pyrene); 5315-79-7 (1- ... Adult, Benzo(a)pyrene/metabolism, Biomarkers/metabolism, Chromatography, High Pressure Liquid, Cotinine/urine, Creatinine/urine ... Nitrosamine and benzo[a]pyrene DNA adducts were measured in lymphocytes. CYP1A2 activity was greater (p,0.0001) in cigarette ... Cytochrome P-450 CYP1A2/metabolism, Humans, Male, Middle Aged, Nitrosamines/blood, Plants, Toxic, Pyrenes/metabolism, Smoking/ ...
Inhibition of benzo(a)pyrene-induced forestomach carcinogenesis in mice by thymoquinone. Eur J Cancer Prev 1999;8:435-40. View ...
Tentative detection of anthracene and pyrene in the Red Rectangle Aug 2003 Amino acid detected in space Apr 2002 Discovery of ...
... or any other sulfonated pyrene based fluorescent dyes. ...
Roberto A, Larsson BS, Tjälve H. Uptake of 7,12-dimethylbenz(a)anthracene and benzo(a)pyrene in melanin-containing tissues. ...
The alarming discovery involved excessive levels of Benzo[a]pyrene (BaP), a potent carcinogen classified as Group 1 ( ... Understanding Benzo[a]pyrene (BaP) and its Health Risks. BaP is a ubiquitous environmental contaminant formed during the ... "Benzo[a]pyrene in the environment: A review." Journal of Hazardous Materials 166.1 (2009): 1002-1027. ... "Oral intake of a bolus of 32P-postlabeled benzo(a)pyrene by germ-free and conventional rats: Tissue distribution and excretion ...
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These products often contain additional substances (e.g., benzo(a)pyrene, vinyl chloride, polonium 210) that cause cancer in ...
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BENZO(A)PYRENE BHC-GAMMA. CARBOFURAN CHLORDANE DALAPON DI(2-ETHYLHEXYL) ADIPATE DI(2-ETHYLHEXYL) PHTHALATE DINOSEB DIQUAT ...
... pyrene; Beryllium; Bromacil; Bromate; Bromochloromethane; Bromomethane; Cadmium; Carbofuran; Carbon tetrachloride; Chlordane; ...
benzo(a)pyrene. Remarks:. +S9. Untreated negative controls:. no. Negative solvent / vehicle controls:. yes. True negative ... pyrene/mL in presence of metabolic activation] ... pyrene/mL in presence of metabolic activation] ...
Benzo[a]pyrene (BaP); Benzo[e]pyrene (BeP); Benzo[a]anthracene (BaA); Chrysen (CHR); Benzo[b]fluoroanthene (BbFA); Benzo[j] ... Benzo[a]pyrene (BaP); Benzo[e]pyrene (BeP); Benzo[a]anthracene (BaA); Chrysen (CHR); Benzo[b]fluoroanthene (BbFA); Benzo[j] ... pyrene (BaP), or More than 10mg/kg of the sum of all restricted PAHs This Regulation is applied from 2010 by Petlas Tire. ... pyrene (BaP), or More than 10mg/kg of the sum of all restricted PAHs This Regulation is applied from 2010 by Petlas Tire. ...
Les Caves de Pyrene. Mielie Green, Testalonga 2022. Mielie Green, Testalonga 2022 ...
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Acenaphthene, Acenaphthylene, Anthracene, Benzo(a)anthracene, Benzo(a)pyrene, Benzo(b)fluoranthene, Benzo(g,h,i)perylene, Benzo ... k)fluoranthene, Chrysene, Dibenzo(a,h)anthracene, Fluoranthene, Fluorene, Indeno(1,2,3-cd)pyrene, Phenanthrene, Pyrene ...
  • Benzo[a]pyrene is a polycyclic aromatic hydrocarbon, or PAH, released from combustion of fossil fuels and waste incinerators. (ewg.org)
  • The EWG Health Guideline of 0.007 ppb for benzo[a]pyrene was defined by the California Office of Environmental Health Hazard Assessment as a public health goal, the level of a drinking water contaminant that does not pose a significant health risk. (ewg.org)
  • The legal limit for benzo[a]pyrene, established in 1992, was based on analytical detection limits at the time that the standard was set. (ewg.org)
  • Project Summary This R01 is about our discovery of a surprising and unexpected way in which adipose tissue increases the vulnerability of mammary epithelial cells to benzo(a)pyrene (BaP), a Group I-classified carcinogen, by inducing the aryl hydrocarbon receptor (AhR) protein. (nih.gov)
  • All living organisms could be exposed to Benzo[a]pyrene (BaP) that resulted mainly from burning of industrial carbon compounds, volcanic eruptions and forest fires causing genotoxic and carcinogenic effects. (scialert.net)
  • Benzo(a)pyrene (BaP) is a widespread polycyclic aromatic hydrocarbon compound in the environment. (scialert.net)
  • Quercetin Attenuates Benzo (α) pyrene-induced CYP1A Expression[J]. Biomedical and Environmental Sciences, 2017, 30(4): 308-313. (besjournal.com)
  • Possible mechanisms of quercetin-driven inhibition of the benzo (α) pyrene (BaP)-induced AhR-dependent signaling pathway. (besjournal.com)
  • Seven PNA's (naphthalene, fluorene, phenanthrene, pyrene, chrysene, benzo[b]fluoranthrene, benzo[a]pyrene) were detected at trace concentrations (1 to 34 ppm) in bulk samples of the WCO. (cdc.gov)
  • Polycyclic aromatic hydrocarbons (PAHs) such as naphthalene (Nap) and benzo[a]pyrene (B[a]P) are common in the water column and sediments of estuarine and coastal areas. (odu.edu)
  • White, Gregory V.. "The Effects of Two Polycyclic Aromatic Hydrocarbons Benzo[a]pyrene and Naphthalene on Reproductive Success Embryological Development Larval Physiology and Mortality of the Mud Crab Rhithropanopeus harisii (Gould)" (1990). (odu.edu)
  • Roberto A, Larsson BS, Tjälve H. Uptake of 7,12-dimethylbenz(a)anthracene and benzo(a)pyrene in melanin-containing tissues. (medscape.com)
  • This paper displays the possible pathways for the degradation of phenanthrene and pyrene (as two abundant PAHs in the environment) in maize plant. (researchsquare.com)
  • Maize plants were treated by phenanthrene and pyrene and after 7, 14, and 21 days, a number of intermediate compounds were identified using gas chromatography-mass spectroscopy (GC-MS) analysis. (researchsquare.com)
  • The obtained results showed that although maize plant can metabolize both compounds, but the degradation rate of phenanthrene was faster and higher than that of pyrene. (researchsquare.com)
  • The degradation of phenanthrene occurred mainly in the second week, whereas the degradation of pyrene was slower and mostly happened after the third week. (researchsquare.com)
  • The most outstanding identified intermediates were quinones, dihydrodiols, phthalate and phenolic compounds which were formed through the cleavage of phenanthrene and pyrene. (researchsquare.com)
  • Accordingly, the probable degradation pathways of phenanthrene and pyrene in maize plants were proposed. (researchsquare.com)
  • 2014 ). For example, cis-4,5-pyrene dihydrodiol, 4-5-phenanthrene dicarboxylic acid, 1-hydroxy-2-naphthoic acid, 2-carboxybenzaldehyde, phthalic acid, and protocatechuic acid were detected as intermediate compounds through the catabolism of pyrene (Rehmann et al. (researchsquare.com)
  • Hence, the main objectives of the present research were: 1) to assess the ability of maize plants to degrade phenanthrene and pyrene as two prevalent PAHs in the environment, 2) to identify the intermediate compounds resulting from their biodegradation by gas chromatography-mass spectroscopy (GC-MS) analysis, and 3) to propose the possible phytodegradation pathways. (researchsquare.com)
  • phenanthrene, and pyrene. (cdc.gov)
  • Pyrene is one of the most attractive polycyclic aromatic hydrocarbons (PAHs) in photochemistry. (thieme-connect.com)
  • As a peri-fused PAH, pyrene is much more resonance-stabilized than its five-member-ring containing isomer fluoranthene. (wikipedia.org)
  • Its derivatives are also valuable molecular probes via fluorescence spectroscopy, having a high quantum yield and lifetime (0.65 and 410 nanoseconds, respectively, in ethanol at 293 K). Pyrene was the first molecule for which excimer behavior was discovered. (wikipedia.org)
  • The adsorption of the two-dimensionally chiral naphtho[2,3-a]pyrene molecule has been studied on Au(111). (semanticscholar.org)
  • Our theoretical calculations and electrochemical results show that the formation of a pyrene-nitrilotriacetic acid SAM enforces a direct electron transfer from graphene to the SAM, while the addition of the Ni 2+ cation and imidazole reverses the charge transfer direction, allowing an atomic control of the electron flow, which is essential for a true working device. (rsc.org)
  • In this review, we summarize recent developments in pyrene-catalyzed photoinduced organic reactions occurring via energy transfer or single-electron transfer based on the excited state of the pyrene. (thieme-connect.com)
  • Pyrene and its derivatives are used commercially to make dyes and dye precursors, for example pyranine and naphthalene-1,4,5,8-tetracarboxylic acid. (wikipedia.org)
  • Pyrene forms during incomplete combustion of organic compounds. (wikipedia.org)
  • Pyrene undergoes a series of hydrogenation reactions and is susceptible to halogenation, Diels-Alder additions, and nitration, all with varying degrees of selectivity. (wikipedia.org)
  • Although it is not as problematic as benzopyrene, animal studies have shown pyrene is toxic to the kidneys and liver. (wikipedia.org)
  • The addition of a pyrene-nitrilotriacetic acid layer to a graphene metal electrode enhances the charge transfer within the device. (rsc.org)
  • pyrene from the view of nanoclusters: size- and nanoplastic adsorption-dependent bioavailability. (bvsalud.org)
  • Experiments in pigs show that urinary 1-hydroxypyrene is a metabolite of pyrene, when given orally. (wikipedia.org)
  • Les Caves de Pyrene is an importer, agent, distributor, and retailer of many wines from around the world. (lescaves.co.uk)
  • The behaviour of pyrene and its decomposition by-products in chlorination and their aryl hydrocarbon receptor (AhR) ligand activities were investigated. (iwaponline.com)
  • The normal and delayed molecular ( M ∗ ) and excimer ( D ∗ ) fluorescence and the phosphorescence of pyrene ( M) inpropylene glycol have been studied from 295°K to 200°K. A general kinetic scheme is used for analysis of the data, and the behaviour is interpreted in terms of the temperature dependence of the competing rate processes. (harvard.edu)
  • 2) Effect of hydrophobic interaction in the poly(methacrylic acid)/pyrene end-labeled poly(ethylene glycol) complex, Macromolecules, 1987 , 20 (8), pp 1839-1847, Text . (creativepegworks.com)
  • 3) Biotin-pyrene conjugates with poly(ethylene glycol) spacers are convenient fluorescent probes for avidin and streptavidin, Bioconjug Chem. (creativepegworks.com)
  • The strong (close to irreversible) pi-pi stacking between pyrene and the aromatic rings on single wall and multi-walled carbon nanotubes. (creativepegworks.com)
  • Pyrene-PEG-MAL one of the many PEGylated pyrene derivatives for surface functionalization of carbon nanotubes and graphene. (creativepegworks.com)
  • 1-Hydroxypyrene as an indicator of pyrene exposure. (nih.gov)
  • The yeast assay revealed that pyrene-4,5-dione was an AhR agonist. (iwaponline.com)
  • It is a very simple process to prepare pyrene coated carbon nanoparticles (such as CNT). (creativepegworks.com)
  • The same PEGylated pyrene reagent also works for graphene or any carbon nanoparticle surfaces with curvatures that fit well with the pyrene structure. (creativepegworks.com)
  • When the effects of the initial pyrene concentration were investigated, a lower pyrene concentration was decomposed faster. (iwaponline.com)
  • The metabolic pathways and enzyme-inducing effects of specific PAHs, such as benz[a]pyrene, have been actively studied to elucidate cancer potential and causal mechanisms (Ramesh et al. (cdc.gov)
  • In the study on pyrene behaviour in chlorination, the pyrene and chlorine concentrations and the pH range were 0.82-21 μg l −1 , 2.0-2.1 mg l −1 and 3.2-10, respectively. (iwaponline.com)
  • An overview of Genetic Toxicology Rodent Cytogenetics study conclusions related to Pyrene (129-00-0). (nih.gov)
  • It requires just well dispersing CNTs with the PEG-pyrene reagents in either organic solvents or aqueous solutions. (creativepegworks.com)
  • Genetic Toxicity Evaluation of Pyrene in Salmonella/E.coli Mutagenicity Test or Ames Test. (nih.gov)
  • Pyrene decomposition in chlorination was inhibited by the presence of 30 mM ethanol, but was enhanced by the presence of 3.0 and 6.0 mgC l −1 humic acid. (iwaponline.com)