A class of compounds that contain a -NH2 and a -NO radical. Many members of this group have carcinogenic and mutagenic properties.
A substituted carcinogenic nitrosamine.
A nitrosamine derivative with alkylating, carcinogenic, and mutagenic properties. It causes serious liver damage and is a hepatocarcinogen in rodents.
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.
Carcinogenic nitrosamine that may be formed from preservatives in meats during their preparation or in the liver during metabolism.
A sulfanilamide that is used as an anti-infective agent.
A high-molecular-weight polymeric elastomer derived from the milk juice (LATEX) of HEVEA brasiliensis and other trees and plants. It is a substance that can be stretched at room temperature to at least twice its original length and after releasing the stress, retract rapidly, and recover its original dimensions fully.
F344 rats are an inbred strain of albino laboratory rats (Rattus norvegicus) that have been widely used in biomedical research due to their consistent and reliable genetic background, which facilitates the study of disease mechanisms and therapeutic interventions.
A nitrosamine derivative with alkylating, carcinogenic, and mutagenic properties.
A plant genus of the family SOLANACEAE. Members contain NICOTINE and other biologically active chemicals; its dried leaves are used for SMOKING.
Plants or plant parts which are harmful to man or other animals.
Tumors or cancer of the URINARY BLADDER.
Powdered or cut pieces of leaves of NICOTIANA TABACUM which are inhaled through the nose, chewed, or stored in cheek pouches. It includes any product of tobacco that is not smoked.
Salts of nitrous acid or compounds containing the group NO2-. The inorganic nitrites of the type MNO2 (where M=metal) are all insoluble, except the alkali nitrites. The organic nitrites may be isomeric, but not identical with the corresponding nitro compounds. (Grant & Hackh's Chemical Dictionary, 5th ed)
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.
The combination of two or more different factors in the production of cancer.
Dimethylamines are organic compounds that contain two methyl groups (-CH3) bonded to a nitrogen atom (N), with the general formula (CH3)2NH. They can act as secondary amines and are commonly used in chemical synthesis, but they are not typically found as natural components in the human body.
Nitroso compounds are organic or inorganic substances containing the nitroso functional group, which consists of a nitrogen atom bonded to an oxygen atom through a single covalent bond, often abbreviated as -NO.
Viscous materials composed of complex, high-molecular-weight compounds derived from the distillation of petroleum or the destructive distillation of wood or coal. (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)
An ethanol-inducible cytochrome P450 enzyme that metabolizes several precarcinogens, drugs, and solvents to reactive metabolites. Substrates include ETHANOL; INHALATION ANESTHETICS; BENZENE; ACETAMINOPHEN and other low molecular weight compounds. CYP2E1 has been used as an enzyme marker in the study of alcohol abuse.
Infection with flukes of the genus Opisthorchis.
Experimentally induced new abnormal growth of TISSUES in animals to provide models for studying human neoplasms.
Inorganic or organic salts and esters of nitric acid. These compounds contain the NO3- radical.
'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.
Tumors or cancer of the NOSE.
An independent administrative agency concerned with maintaining competitive free enterprise by prohibiting unfair methods of competition and unfair deceptive acts or practices.
Procedures or techniques used to keep food from spoiling.
Articles of food which are derived by a process of manufacture from any portion of carcasses of any animal used for food (e.g., head cheese, sausage, scrapple).
Nicotine is highly toxic alkaloid. It is the prototypical agonist at nicotinic cholinergic receptors where it dramatically stimulates neurons and ultimately blocks synaptic transmission. Nicotine is also important medically because of its presence in tobacco smoke.
A species of the genus ERYTHROCEBUS, subfamily CERCOPITHECINAE, family CERCOPITHECIDAE. It inhabits the flat open arid country of Africa. It is also known as the patas monkey or the red monkey.
Butanones, also known as methyl ethyl ketone or MEK, are organic compounds consisting of a four-carbon chain with a ketone functional group located at the second carbon atom, classified as dimethyl ketones, and commonly used in industrial and laboratory settings as solvents and chemical intermediates.
Stones in the URINARY BLADDER; also known as vesical calculi, bladder stones, or cystoliths.
A musculomembranous sac along the URINARY TRACT. URINE flows from the KIDNEYS into the bladder via the ureters (URETER), and is held there until URINATION.
Organic compounds with the general formula R-NCS.
A non-crystalline form of silicon oxide that has absorptive properties. It is commonly used as a desiccating agent and as a stationary phase for CHROMATOGRAPHY. The fully hydrated form of silica gel has distinct properties and is referred to as SILICIC ACID.
A pyrazolone with analgesic, anti-inflammatory, and antipyretic properties but has risk of AGRANULOCYTOSIS. A breath test with 13C-labeled aminopyrine has been used as a non-invasive measure of CYTOCHROME P-450 metabolic activity in LIVER FUNCTION TESTS.
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.
The N-glucuronide conjugate of cotinine is a major urinary metabolite of NICOTINE. It thus serves as a biomarker of exposure to tobacco SMOKING. It has CNS stimulating properties.
Nitrous acid sodium salt. Used in many industrial processes, in meat curing, coloring, and preserving, and as a reagent in ANALYTICAL CHEMISTRY TECHNIQUES. It is used therapeutically as an antidote in cyanide poisoning. The compound is toxic and mutagenic and will react in vivo with secondary or tertiary amines thereby producing highly carcinogenic nitrosamines.
Laws and regulations concerned with industrial processing and marketing of foods.
Substances which are of little or no nutritive value, but are used in the processing or storage of foods or animal feed, especially in the developed countries; includes ANTIOXIDANTS; FOOD PRESERVATIVES; FOOD COLORING AGENTS; FLAVORING AGENTS; ANTI-INFECTIVE AGENTS (both plain and LOCAL); VEHICLES; EXCIPIENTS and other similarly used substances. Many of the same substances are PHARMACEUTIC AIDS when added to pharmaceuticals rather than to foods.
A phase transition from liquid state to gas state, which is affected by Raoult's law. It can be accomplished by fractional distillation.
Measurement and evaluation of the components of substances to be taken as FOOD.
Compounds with a six membered aromatic ring containing NITROGEN. The saturated version is PIPERIDINES.
Respiratory Tract Neoplasms are defined as abnormal growths or tumors that develop within the respiratory system, including the nose, sinuses, throat (pharynx), voice box (larynx), windpipe (trachea), bronchi, and lungs, which can be benign or malignant, with the potential to cause significant morbidity and mortality.
The products of chemical reactions that result in the addition of extraneous chemical groups to DNA.
Tumors or cancer of the LUNG.
Agents that reduce the frequency or rate of spontaneous or induced tumors independently of the mechanism involved.
A genus of the family Muridae having three species. The present domesticated strains were developed from individuals brought from Syria. They are widely used in biomedical research.
Guanine is a purine nucleobase, one of the four nucleobases in the nucleic acid of DNA and RNA, involved in forming hydrogen bonds between complementary base pairs in double-stranded DNA molecules.
A malignant neoplasm derived from TRANSITIONAL EPITHELIAL CELLS, occurring chiefly in the URINARY BLADDER; URETERS; or RENAL PELVIS.
The edible portions of any animal used for food including domestic mammals (the major ones being cattle, swine, and sheep) along with poultry, fish, shellfish, and game.
An alcoholic beverage usually made from malted cereal grain (as barley), flavored with hops, and brewed by slow fermentation.
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)
A reagent used mainly to induce experimental liver cancer. According to the Fourth Annual Report on Carcinogens (NTP 85-002, p. 89) published in 1985, this compound "may reasonably be anticipated to be a carcinogen." (Merck, 11th ed)
Tests of chemical substances and physical agents for mutagenic potential. They include microbial, insect, mammalian cell, and whole animal tests.
Inhaling and exhaling the smoke of burning TOBACCO.
Highly reactive chemicals that introduce alkyl radicals into biologically active molecules and thereby prevent their proper functioning. Many are used as antineoplastic agents, but most are very toxic, with carcinogenic, mutagenic, teratogenic, and immunosuppressant actions. They have also been used as components in poison gases.
Derivatives of GLUCURONIC ACID. Included under this heading are a broad variety of acid forms, salts, esters, and amides that include the 6-carboxy glucose structure.
Closed vesicles of fragmented endoplasmic reticulum created when liver cells or tissue are disrupted by homogenization. They may be smooth or rough.
Experimentally induced tumors of the LIVER.
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.
Placing of a hydroxyl group on a compound in a position where one did not exist before. (Stedman, 26th ed)
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.
A nitrosourea compound with alkylating, carcinogenic, and mutagenic properties.
Tumors or cancer of the ESOPHAGUS.
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)
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 number of cells in a tissue or organ without tumor formation. It differs from HYPERTROPHY, which is an increase in bulk without an increase in the number of cells.
Contamination of the air by tobacco smoke.
Pathological processes that tend eventually to become malignant. (From Dorland, 27th ed)
Conversion into nitroso compounds. An example is the reaction of nitrites with amino compounds to form carcinogenic N-nitrosamines.

The effect of cotinine or cigarette smoke co-administration on the formation of O6-methylguanine adducts in the lung and liver of A/J mice treated with 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) (1/1044)

4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK), a tobacco-specific nitrosamine, induces lung adenomas in A/J mice, following a single intraperitoneal (i.p.) injection. However, inhalation of tobacco smoke has not induced or promoted tumors in these mice. NNK-induced lung tumorigenesis is thought to involve O6-methylguanine (O6MeG) formation, leading to GC-->AT transitional mispairing and an activation of the K-ras proto-oncogene in the A/J mouse. NNK can be metabolized by several different cytochromes P450, resulting in a number of metabolites. Formation of the promutagenic DNA adduct O6MeG is believed to require metabolic activation of NNK by cytochrome P450-mediated alpha-hydroxylation of the methylene group adjacent to the N-nitroso nitrogen to yield the unstable intermediate, methanediazohydroxide. Nicotine, cotinine (the major metabolite of nicotine), and aqueous cigarette tar extract (ACTE) have all been shown to effectively inhibit metabolic activation of NNK to its mutagenic form, most likely due to competitive inhibition of the cytochrome P450 enzymes involved in alpha-hydroxylation of NNK. The objective of the current study was to monitor the effects of cotinine and cigarette smoke (CS) on the formation of O6MeG in target tissues of mice during the acute phase of NNK treatment. To test the effect of cotinine, mature female A/J mice received a single intraperitoneal injection of NNK (0, 2.5, 5, 7.5, or 10 mumole/mouse) with cotinine administered at a total dose of 50 mumole/mouse in 3 separate i.p. injections, administered 30 min before, immediately after, and 30 min after NNK treatment. To test the effect of whole smoke exposure on NNK-related O6MeG formation, mice were exposed to smoke generated from Kentucky 1R4F reference cigarettes at 0, 0.4, 0.6, or 0.8 mg wet total particulate matter/liter (WTPM/L) for 2 h, with a single i.p. injection of NNK (0, 3.75, or 7.5 mumole/mouse) midway through the exposure. Cigarette smoke alone failed to yield detectable levels of O6MeG. The number of O6MeG adducts following i.p. injection of NNK was significantly (p < 0.05) reduced in both lung and liver by cotinine and by cigarette smoke exposure. Our results demonstrate that NNK-induced O6MeG DNA adducts in A/J mice are significantly reduced when NNK is administered together with either cotinine, the major metabolite of nicotine, or the parental complex mixture, cigarette smoke.  (+info)

Reduced lung tumorigenesis in human methylguanine DNA--methyltransferase transgenic mice achieved by expression of transgene within the target cell. (2/1044)

Human methylguanine-DNA methyltransferase (MGMT) transgenic mice expressing high levels of O6-alkylguanine-DNA alkyltransferase (AGT) in lung were crossbred to A/J mice that are susceptible to pulmonary adenoma to study the impact of O6-methylguanine (O6mG)-DNA adduct repair on NNK-induced lung tumorigenesis. Expression of the chimeric human MGMT transgene in lung was identified by northern and western blot analysis, immunohistochemistry assay and enzymatic assay. AGT activity was 17.6 +/- 3.2 versus 1.2 +/- 0.4 fmol/microg DNA in lung of MGMT transgenic mice compared with non-transgenic mice. Immunohistochemical staining with anti-human AGT antibody showed that human AGT was expressed throughout the lung. However, some epithelial cells of bronchi and alveoli did not stain for human AGT, suggesting that the human MGMT transgene expression was heterogeneous. After 100 mg/kg NNK i.p. injection in MGMT transgenic mice, lung AGT activity remained much higher and levels of lung O6mG-DNA adducts in MGMT transgenic mice were lower than those of non-transgenic mice. In the tumorigenesis study, mice received 100 mg/kg NNK at 6 weeks of age and were killed 44 weeks later. Ten of 17 MGMT transgenic mice compared with 16 of 17 non-transgenic mice had lung tumors, P < 0.05. MGMT transgenic mice had lower multiplicity and smaller sized lung tumors than non-transgenic mice. Moreover, a reduction in the frequency of K-ras mutations in lung tumors was found in MGMT transgenic mice (6.7 versus 50% in non-transgenic mice). These results indicate that high levels of AGT expressed in mouse lung reduce lung tissue susceptibility to NNK-induced tumorigenesis due to increased repair capacity for O6mG, subsequently, decreased mutational activation of K-ras oncogene. Heterogeneity in the level of AGT expressed in different lung cell populations or other forms of carcinogenic DNA damage caused by NNK may explain the residual incidence of lung tumors in MGMT transgenic mice.  (+info)

Induction of adenocarcinoma from hamster pancreatic islet cells treated with N-nitrosobis(2-oxopropyl)amine in vitro. (3/1044)

Our previous studies in the hamster pancreatic cancer model have indicated that pancreatic ductal adenocarcinomas derive not only from ductal/ductular cells but also from islets. To verify the presence of carcinogen-responsive cells within islets, we tested the effect of the pancreatic carcinogen N-nitrosobis(2-oxopropyl)amine (BOP) on recently established continuous hamster pancreatic islet culture. Isolated pure pancreatic islets of hamsters were treated in vitro with BOP at a concentration of 0.25 mM three times a week for 19 weeks. Each treatment week was designed as a stage. The growth of these cells, designated KL5B, was compared with untreated cultured islets, designated KL5N. As in our previous study, between 14 and 21 days of culture, exocrine and intermediary cells developed within both KL5N and KL5B islets, which were then replaced by undifferentiated cells. No differences were found in the growth patterns of KL5N and KL5B until stage 4, when KL5B cells showed accelerated cell growth and cell pleomorphism, which increased gradually at later stages of treatment. Anchorage-independent and in vivo growth did not appear until stage 19. Mutation of c-Ki-ras at codon 12 (GGT-->GAT) was detected in KL5B cells but not in KL5N cells. In vivo KL5B cells formed anaplastic invasive cancer with areas of glandular formation, overexpressed TGF-alpha and EGFR, expressed cytokeratin, vimentin, laminin and alpha-1 antitrypsin and reacted strongly with L-phytohemagglutinin and tomato lectin. Some cells within islets are responsive to the carcinogenic effects of BOP. Whether these cells represent islet cell precursors (stem cells) or malignant transdifferentiated islet cells remains to be seen.  (+info)

5-Aza-2'-deoxycytidine is chemopreventive in a 4-(methyl-nitrosamino)-1-(3-pyridyl)-1-butanone-induced primary mouse lung tumor model. (4/1044)

Carcinogenesis is a multistep process in which many alterations in both genetic and epigenetic controls lead to a growth advantage for neoplastic cells. Hypermethylation has been established as the basis of genomic imprinting, but recent studies have also shown that alterations in genomic methylation patterns may contribute to tumorigenesis. The chemical 5-aza-2'-deoxycytidine (5-aza-dC) has been used both in vitro and in vivo to inhibit DNA methylation. In this study, we investigated the chemopreventive efficacy of 5-aza-dC in a well-established primary mouse lung tumor model. Five-week-old male (C3H/HeJ x A/J) F1 hybrid mice were treated for 24 consecutive weeks with 5-aza-dC, three times per week i.p. Lung tumors were induced with two consecutive weekly doses of 4-(methyl-nitrosamino)-1-(3-pyridyl)-1-butanone starting 1 week after initial treatment with 5-aza-dC. We demonstrated that 5-aza-dC exhibits a chemopreventive effect in this primary mouse lung tumor model which, like human lung adenocarcinomas, harbors an activating K-ras mutation. Treatment with 5-aza-dC resulted in a 23% reduction in tumor incidence, as well as a 42% reduction in tumor multiplicity. This work supports further investigation of methylation inhibitors likes 5-aza-dC for early intervention, prevention and treatment of lung cancer.  (+info)

Metabolites of a tobacco-specific carcinogen in urine from newborns. (5/1044)

BACKGROUND: Cigarette smoking during pregnancy can result in fetal exposure to carcinogens that are transferred from the mother via the placenta, but little information is available on fetal uptake of such compounds. We analyzed samples of the first urine from newborns whose mothers did or did not smoke cigarettes for the presence of metabolites of the potent tobacco-specific transplacental carcinogen 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK). METHODS: The urine was collected and analyzed for two metabolites of NNK, 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol (NNAL) and its glucuronide (NNAL-Gluc). Gas chromatography and nitrosamine-selective detection, with confirmation by mass spectrometry, were used in the analyses, which were performed without knowledge of the origin of the urine samples. RESULTS: NNAL-Gluc was detected in 22 (71%) of 31 urine samples from newborns of mothers who smoked; NNAL was detected in four of these 31 urine samples. Neither compound was detected in the 17 urine samples from newborns of mothers who did not smoke. The arithmetic mean level of NNAL plus NNAL-Gluc in the 27 newborns of smokers for which both analytes were quantified was 0.14 (95% confidence interval [CI] = 0.083-0.200) pmol/mL. The levels of NNAL plus NNAL-Gluc in the urine from these babies were statistically significantly higher than those in the urine from newborns of nonsmoking mothers (geometric means = 0.062 [95% CI = 0.035-0.110] and 0.010 [considered as not detected; no confidence interval], respectively; two-sided P<.001). NNAL plus NNAL-Gluc levels in the 18 positive urine samples in which both analytes were quantified ranged from 0.045 to 0.400 pmol/mL, with an arithmetic mean level of 0.20 (95% CI = 0.14-0.26) pmol/mL, about 5%-10% of the levels of these compounds detected in the urine from adult smokers. CONCLUSIONS: Two metabolites of the tobacco-specific transplacental carcinogen NNK can be detected in the urine from newborns of mothers who smoked cigarettes during pregnancy.  (+info)

Chemoprevention of cancer by isothiocyanates, modifiers of carcinogen metabolism. (6/1044)

Substantial quantities of isothiocyanates are released upon consumption of normal amounts of a number of cruciferous vegetables. Some of these naturally occurring isothiocyanates such as phenethyl isothiocyanate (PEITC), benzyl isothiocyanate (BITC) and sulforaphane are effective inhibitors of cancer induction in rodents treated with carcinogens. A large amount of data demonstrate that isothiocyanates act as cancer chemopreventive agents by favorably modifying carcinogen metabolism via inhibition of Phase 1 enzymes and/or induction of Phase 2 enzymes. These effects are quite specific, depending on the structure of the isothiocyanate and carcinogen. One of the most thoroughly studied examples of isothiocyanate inhibition of rodent carcinogenesis is inhibition of 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK)-induced lung tumorigenesis by PEITC. This occurs because PEITC blocks the metabolic activation of NNK, resulting in increased urinary excretion of detoxified metabolites. Similar effects on NNK metabolism have been observed in smokers who consumed watercress, a source of PEITC. On the basis of these observations and knowledge of the carcinogenic constituents of cigarette smoke, a strategy for chemoprevention of lung cancer can be developed.  (+info)

Phospholipid requirement for dimethylnitrosamine demethylation by hamster hepatic microsomal cytochrome P-450 enzyme system. (7/1044)

Extraction with butan-1-ol of freeze-dried microsomal fractions from livers of 3-methyl-cholarthrene-pre-treated hamsters removed about 90% of the total lipid content, but the lipid remaining proved sufficient for the cytochrome P-450 enzyme system to retain about 15-40% of its original catalytic activity for dimethylnitrosamine demethylation. Addition of butan-1-ol-extracted total phospholipid or phosphatidylcholine could not restore any activity, whereas the addition of the synthetic phospholipid dilauroyl phosphatidylcholine was able to restore almost complete activity. Synthetic dipalmitoyl or distearoyl phosphatidylcholine was ineffective in restoring the activity in this reconstituted system.  (+info)

Metabolism and disposition of 4-(methylnitrosamino)-1-(3-pyridyl)-1- butanone (NNK) in rhesus monkeys. (8/1044)

Metabolism and disposition of the tobacco-specific N-nitrosamine, 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK), a potent rodent lung carcinogen, were studied in rhesus monkeys. In three males receiving a single i.v. dose of [5-3H]NNK (0.72 mCi; 4.6-9.8 microg/kg), urine was collected for 10 days. Within the first 24 h, 86.0 +/- 0.7% of the dose was excreted. NNK-derived radioactivity was still detectable in urine 10 days after dosing (total excretion, 92.7 +/- 0.7%). Decay of urinary radioactivity was biexponential with half-lives of 1.7 and 42 h. Metabolite patterns in urine from the first 6 h closely resembled those reported previously for patas monkeys; end products of metabolic NNK activation represented more than 50% of total radioactivity. At later time points, the pattern shifted in favor of NNK detoxification products (60-70% of total radioactivity in urine), mainly 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol (NNAL) and its O-glucuronide conjugates. One female rhesus monkey received a single i.v. dose of [5-3H]NNK (1.72 mCi; 28.4 microg/kg) under isoflurane anesthesia; biliary excretion over 6 h (0.6% of the dose) was 10 times less than predicted by our previously reported rat model. No preferential excretion of NNAL glucuronide was observed in monkey bile. Collectively, these results suggest that the rhesus monkey could be a useful model for NNK metabolism and disposition in humans.  (+info)

Nitrosamines are a type of chemical compound that are formed by the reaction between nitrous acid (or any nitrogen oxide) and secondary amines. They are often found in certain types of food, such as cured meats and cheeses, as well as in tobacco products and cosmetics.

Nitrosamines have been classified as probable human carcinogens by the International Agency for Research on Cancer (IARC). Exposure to high levels of nitrosamines has been linked to an increased risk of cancer, particularly in the digestive tract. They can also cause DNA damage and interfere with the normal functioning of cells.

In the medical field, nitrosamines have been a topic of concern due to their potential presence as contaminants in certain medications. For example, some drugs that contain nitrofurantoin, a medication used to treat urinary tract infections, have been found to contain low levels of nitrosamines. While the risk associated with these low levels is not well understood, efforts are underway to minimize the presence of nitrosamines in medications and other products.

Butylhydroxybutylnitrosamine (OH-BBN or BBN) is a chemical compound that is primarily used in laboratory research as a potent carcinogenic agent. It is known to induce tumors in various organs, particularly in the urinary bladder and liver, when administered to experimental animals.

The IUPAC name for Butylhydroxybutylnitrosamine is N-butyl-N-(4-hydroxybutyl)nitrosamine. Its molecular formula is C8H19NO3. It is a white to off-white crystalline powder, soluble in water and alcohol.

It is important to note that Butylhydroxybutylnitrosamine is not used in human medicine or therapy due to its carcinogenic properties. Its use is restricted to research purposes only, under controlled conditions and with appropriate safety measures in place.

Dimethylnitrosamine is a chemical compound with the formula (CH3)2NNO. It is a potent carcinogen, and is classified as a Class 1 carcinogen by the International Agency for Research on Cancer (IARC). It is known to cause cancer in various organs, including the liver, kidney, and lungs.

Dimethylnitrosamine is formed when nitrogen oxides react with secondary amines under conditions that are commonly encountered in industrial processes or in certain food preservation methods. It can also be found as a contaminant in some foods and cosmetics.

Exposure to dimethylnitrosamine can occur through inhalation, ingestion, or skin contact. The toxic effects of this compound are due to its ability to form DNA adducts, which can lead to mutations and cancer. It is important to minimize exposure to this compound and to take appropriate safety measures when working with it.

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.

N-Nitrosopyrrolidine (NPYR) is a chemical compound that falls under the category of nitrosamines. Nitrosamines are potent carcinogens, and NPYR is no exception. It is formed when nitrites, which can be found in certain foods or used as preservatives, come into contact with secondary amines in the digestive system. NPYR has been shown to cause cancer in various animal models, particularly in the liver and pancreas. However, its carcinogenic effects in humans are still a subject of ongoing research.

Sulfadimethoxine is an antimicrobial agent, specifically a sulfonamide. It is defined as a synthetic antibacterial drug that contains the sulfanilamide nucleus and is used to treat various bacterial infections in both humans and animals. In human medicine, it is used to treat urinary tract infections, bronchitis, and traveler's diarrhea. In veterinary medicine, it is commonly used to treat coccidiosis in animals such as poultry, cattle, and pets.

The drug works by inhibiting the bacterial synthesis of folic acid, which is essential for bacterial growth. It is usually administered orally and is available in various forms, including tablets, capsules, and powder for suspension. As with any medication, it should be used under the guidance of a healthcare professional to ensure its safe and effective use.

I believe there may be some confusion in your question. "Rubber" is not a medical term, but rather a common term used to describe a type of material that is elastic and can be stretched or deformed and then return to its original shape when the force is removed. It is often made from the sap of rubber trees or synthetically.

However, in a medical context, "rubber" might refer to certain medical devices or supplies made from rubber materials, such as rubber gloves used for medical examinations or procedures, or rubber stoppers used in laboratory equipment. But there is no medical definition specifically associated with the term 'Rubber' itself.

F344 is a strain code used to designate an outbred stock of rats that has been inbreeded for over 100 generations. The F344 rats, also known as Fischer 344 rats, were originally developed at the National Institutes of Health (NIH) and are now widely used in biomedical research due to their consistent and reliable genetic background.

Inbred strains, like the F344, are created by mating genetically identical individuals (siblings or parents and offspring) for many generations until a state of complete homozygosity is reached, meaning that all members of the strain have identical genomes. This genetic uniformity makes inbred strains ideal for use in studies where consistent and reproducible results are important.

F344 rats are known for their longevity, with a median lifespan of around 27-31 months, making them useful for aging research. They also have a relatively low incidence of spontaneous tumors compared to other rat strains. However, they may be more susceptible to certain types of cancer and other diseases due to their inbred status.

It's important to note that while F344 rats are often used as a standard laboratory rat strain, there can still be some genetic variation between individual animals within the same strain, particularly if they come from different suppliers or breeding colonies. Therefore, it's always important to consider the source and history of any animal model when designing experiments and interpreting results.

Diethylnitrosamine (DEN) is a potent chemical carcinogen that belongs to the class of nitrosamines. It is known to induce tumors in various organs, including the liver, kidney, and lungs, in different animal species. Diethylnitrosamine requires metabolic activation by enzymes such as cytochrome P450 to exert its carcinogenic effects.

Diethylnitrosamine is not typically used for medical purposes but may be employed in laboratory research to study the mechanisms of chemical carcinogenesis and cancer development. It is essential to handle this compound with care, following appropriate safety protocols, due to its potential hazards.

Tobacco is not a medical term, but it refers to the leaves of the plant Nicotiana tabacum that are dried and fermented before being used in a variety of ways. Medically speaking, tobacco is often referred to in the context of its health effects. According to the World Health Organization (WHO), "tobacco" can also refer to any product prepared from the leaf of the tobacco plant for smoking, sucking, chewing or snuffing.

Tobacco use is a major risk factor for a number of diseases, including cancer, heart disease, stroke, lung disease, and various other medical conditions. The smoke produced by burning tobacco contains thousands of chemicals, many of which are toxic and can cause serious health problems. Nicotine, one of the primary active constituents in tobacco, is highly addictive and can lead to dependence.

'Toxic plants' refer to those species of plants that contain toxic substances capable of causing harmful effects or adverse health reactions in humans and animals when ingested, touched, or inhaled. These toxins can cause a range of symptoms from mild irritation to serious conditions such as organ failure, paralysis, or even death depending on the plant, the amount consumed, and the individual's sensitivity to the toxin.

Toxic plants may contain various types of toxins, including alkaloids, glycosides, proteins, resinous substances, and essential oils. Some common examples of toxic plants include poison ivy, poison oak, nightshade, hemlock, oleander, castor bean, and foxglove. It is important to note that some parts of a plant may be toxic while others are not, and the toxicity can also vary depending on the stage of growth or environmental conditions.

If you suspect exposure to a toxic plant, it is essential to seek medical attention immediately and, if possible, bring a sample of the plant for identification.

Urinary Bladder Neoplasms are abnormal growths or tumors in the urinary bladder, which can be benign (non-cancerous) or malignant (cancerous). Malignant neoplasms can be further classified into various types of bladder cancer, such as urothelial carcinoma, squamous cell carcinoma, and adenocarcinoma. These malignant tumors often invade surrounding tissues and organs, potentially spreading to other parts of the body (metastasis), which can lead to serious health consequences if not detected and treated promptly and effectively.

Smokeless tobacco is a type of tobacco that is not burned or smoked. It's often called "spit" or "chewing" tobacco. The most common forms of smokeless tobacco in the United States are snuff and chewing tobacco. Snuff is a finely ground tobacco that can be dry or moist. Dry snuff is sniffed or taken through the nose, while moist snuff is placed between the lower lip or cheek and gum. Chewing tobacco is plugs, leaves, or twists of tobacco that are chewed or sucked on.

Smokeless tobacco contains nicotine, which is addictive. When you use smokeless tobacco, the nicotine is absorbed through the lining of your mouth and goes directly into your bloodstream. This can lead to a rapid increase in nicotine levels in your body, which can make it harder to quit using tobacco.

Smokeless tobacco also contains harmful chemicals that can cause cancer of the mouth, esophagus, and pancreas. It can also cause other health problems, such as gum disease, tooth decay, and precancerous lesions in the mouth. Using smokeless tobacco can also increase your risk of developing heart disease and having a stroke.

In a medical context, nitrites are typically referred to as organic compounds that contain a functional group with the formula R-N=O, where R represents an alkyl or aryl group. They are commonly used in medicine as vasodilators, which means they widen and relax blood vessels, improving blood flow and lowering blood pressure.

One example of a nitrite used medically is amyl nitrite, which was previously used to treat angina pectoris, a type of chest pain caused by reduced blood flow to the heart muscle. However, its use has largely been replaced by other medications due to safety concerns and the availability of more effective treatments.

It's worth noting that inorganic nitrites, such as sodium nitrite, are also used in medicine for various purposes, including as a preservative in food and as a medication to treat cyanide poisoning. However, these compounds have different chemical properties and uses than organic nitrites.

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.

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.

Dimethylamine is an organic compound with the formula (CH3)2NH. It is a colorless gas that is highly soluble in water and polar solvents. Dimethylamine is a derivative of ammonia (NH3) in which two hydrogen atoms are replaced by methyl groups (CH3).

Dimethylamines, in medical terminology, typically refer to compounds that contain the functional group -N(CH3)2. These compounds can have various biological activities and may be used as drugs or therapeutic agents. For example, dimethylamine is a metabolite of choline, a nutrient important for brain function.

However, it's worth noting that "dimethylamines" is not typically used as a medical term to describe a specific condition or diagnosis. If you have any concerns about exposure to dimethylamine or its potential health effects, it would be best to consult with a healthcare professional.

Nitroso compounds are a class of chemical compounds that contain a nitroso functional group, which is composed of a nitrogen atom bonded to an oxygen atom with a single covalent bond. The general formula for nitroso compounds is R-N=O, where R represents an organic group such as an alkyl or aryl group.

Nitroso compounds are known to be reactive and can form under various physiological conditions. They have been implicated in the formation of carcinogenic substances and have been linked to DNA damage and mutations. In the medical field, nitroso compounds have been studied for their potential use as therapeutic agents, particularly in the treatment of cancer and cardiovascular diseases. However, their use is limited due to their potential toxicity and carcinogenicity.

It's worth noting that exposure to high levels of nitroso compounds can be harmful to human health, and may cause respiratory, dermal, and ocular irritation, as well as potential genotoxic effects. Therefore, handling and storage of nitroso compounds should be done with caution, following appropriate safety guidelines.

"Tars" is not a recognized medical term. However, "tarso-" is a prefix in anatomy that refers to the ankle or hind part of an organ. For example, the tarsal bones are the bones that make up the ankle and the rear part of the foot. Additionally, tarsus can refer to the thickened portion of the eyelid which contains the eyelashes. It is important to ensure you have the correct term when seeking medical information.

Cytochrome P-450 CYP2E1 is a specific isoform of the cytochrome P-450 enzyme system, which is involved in the metabolism of various xenobiotics and endogenous compounds. This enzyme is primarily located in the liver and to some extent in other organs such as the lungs, brain, and kidneys.

CYP2E1 plays a significant role in the metabolic activation of several procarcinogens, including nitrosamines, polycyclic aromatic hydrocarbons, and certain solvents. It also contributes to the oxidation of various therapeutic drugs, such as acetaminophen, anesthetics, and anticonvulsants. Overexpression or induction of CYP2E1 has been linked to increased susceptibility to chemical-induced toxicity, carcinogenesis, and alcohol-related liver damage.

The activity of CYP2E1 can be influenced by various factors, including genetic polymorphisms, age, sex, smoking status, and exposure to certain chemicals or drugs. Understanding the regulation and function of this enzyme is crucial for predicting individual susceptibility to chemical-induced toxicities and diseases, as well as for optimizing drug therapy and minimizing adverse effects.

Opisthorchiasis is a parasitic infection caused by the trematode flatworms of the genus Opisthorchiidae, specifically Opisthorchis viverrini and Opisthorchis felineus. These flatworms are transmitted to humans through the consumption of raw or undercooked fish that contain the infective larval stage (metacercariae) of the parasite.

Once ingested, the metacercariae excyst in the small intestine and migrate to the bile ducts of the liver, where they mature into adult worms and reside. The adults can live for several years in the host's body, producing eggs that are released into the bile and then passed through the stool.

The infection can cause a range of symptoms, including abdominal pain, diarrhea, liver enlargement, and bile duct inflammation. Chronic opisthorchiasis can lead to more severe complications such as cholangitis, cholecystitis, gallstones, and liver cirrhosis. In some cases, it may also increase the risk of developing cholangiocarcinoma, a rare but aggressive form of bile duct cancer.

Preventive measures include avoiding the consumption of raw or undercooked fish, particularly in areas where the infection is endemic, and practicing good personal hygiene to prevent fecal-oral transmission. Treatment typically involves the use of anti-parasitic drugs such as praziquantel or albendazole to kill the adult worms and prevent further complications.

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.

Nitrates are chemical compounds that consist of a nitrogen atom bonded to three oxygen atoms (NO3-). In the context of medical science, nitrates are often discussed in relation to their use as medications or their presence in food and water.

As medications, nitrates are commonly used to treat angina (chest pain) caused by coronary artery disease. Nitrates work by relaxing and widening blood vessels, which improves blood flow and reduces the workload on the heart. Some examples of nitrate medications include nitroglycerin, isosorbide dinitrate, and isosorbide mononitrate.

In food and water, nitrates are naturally occurring compounds that can be found in a variety of vegetables, such as spinach, beets, and lettuce. They can also be present in fertilizers and industrial waste, which can contaminate groundwater and surface water sources. While nitrates themselves are not harmful, they can be converted into potentially harmful compounds called nitrites under certain conditions, particularly in the digestive system of young children or in the presence of bacteria such as those found in unpasteurized foods. Excessive levels of nitrites can react with hemoglobin in the blood to form methemoglobin, which cannot transport oxygen effectively and can lead to a condition called methemoglobinemia.

'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.

Nose neoplasms refer to abnormal growths or tumors in the nasal cavity or paranasal sinuses. These growths can be benign (non-cancerous) or malignant (cancerous). Benign neoplasms are typically slow-growing and do not spread to other parts of the body, while malignant neoplasms can invade surrounding tissues and have the potential to metastasize.

Nose neoplasms can cause various symptoms such as nasal congestion, nosebleeds, difficulty breathing through the nose, loss of smell, facial pain or numbness, and visual changes if they affect the eye. The diagnosis of nose neoplasms usually involves a combination of physical examination, imaging studies (such as CT or MRI scans), and biopsy to determine the type and extent of the growth. Treatment options depend on the type, size, location, and stage of the neoplasm and may include surgery, radiation therapy, chemotherapy, or a combination of these approaches.

The Federal Trade Commission (FTC) is not a medical organization or agency, but rather it is a consumer protection agency in the United States government. The FTC is responsible for protecting consumers and promoting competition by preventing anticompetitive, deceptive, and unfair business practices. While the FTC does not provide medical definitions, it may be involved in investigating and taking enforcement actions related to false or misleading health claims made by businesses.

Food preservation, in the context of medical and nutritional sciences, refers to the process of treating, handling, and storing food items to reduce the risk of foodborne illness and to extend their shelf life. The goal is to prevent the growth of pathogenic microorganisms such as bacteria, yeasts, and mold, as well as to slow down the oxidation process that can lead to spoilage.

Common methods of food preservation include:

1. Refrigeration and freezing: These techniques slow down the growth of microorganisms and enzyme activity that cause food to spoil.
2. Canning: This involves sealing food in airtight containers, then heating them to destroy microorganisms and inactivate enzymes.
3. Dehydration: Removing water from food inhibits the growth of bacteria, yeasts, and molds.
4. Acidification: Adding acidic ingredients like lemon juice or vinegar can lower the pH of food, making it less hospitable to microorganisms.
5. Fermentation: This process involves converting sugars into alcohol or acids using bacteria or yeasts, which can preserve food and also enhance its flavor.
6. Irradiation: Exposing food to small doses of radiation can kill bacteria, parasites, and insects, extending the shelf life of certain foods.
7. Pasteurization: Heating food to a specific temperature for a set period of time can destroy harmful bacteria while preserving the nutritional value and taste.

Proper food preservation is crucial in preventing foodborne illnesses and ensuring the safety and quality of the food supply.

Medical definitions typically do not include terms like "meat products" as they are too broad and not specific to medical conditions or treatments. However, in a general food science or nutrition context, "meat products" could be defined as:

Processed or unprocessed foods that contain meat or meat derivatives as the primary ingredient. This can include various types of muscle tissue from mammals, birds, fish, and other animals, along with any accompanying fat, skin, blood vessels, and other tissues. Meat products may be fresh, cured, smoked, or cooked, and they may also contain additional ingredients like salt, sugar, preservatives, and flavorings. Examples of meat products include beef jerky, bacon, sausages, hot dogs, and canned meats.

Nicotine is defined as a highly addictive psychoactive alkaloid and stimulant found in the nightshade family of plants, primarily in tobacco leaves. It is the primary component responsible for the addiction to cigarettes and other forms of tobacco. Nicotine can also be produced synthetically.

When nicotine enters the body, it activates the release of several neurotransmitters such as dopamine, norepinephrine, and serotonin, leading to feelings of pleasure, stimulation, and relaxation. However, with regular use, tolerance develops, requiring higher doses to achieve the same effects, which can contribute to the development of nicotine dependence.

Nicotine has both short-term and long-term health effects. Short-term effects include increased heart rate and blood pressure, increased alertness and concentration, and arousal. Long-term use can lead to addiction, lung disease, cardiovascular disease, and reproductive problems. It is important to note that nicotine itself is not the primary cause of many tobacco-related diseases, but rather the result of other harmful chemicals found in tobacco smoke.

'Erythrocebus patas' is a scientific name for the Patas monkey, also known as the hussar monkey or red monkey. It belongs to the family Cercopithecidae and is native to the savannas and woodlands of central Africa. The Patas monkey is known for its long legs, slender body, and reddish-brown fur. It is the fastest primate, capable of reaching speeds up to 34 miles per hour (55 kilometers per hour).

The medical community may not have a specific definition related to 'Erythrocebus patas' as it is primarily studied by zoologists and biologists. However, understanding the characteristics and habits of this species can contribute to broader scientific knowledge and potentially inform research in fields such as comparative medicine or evolutionary biology.

Butanones are a group of chemical compounds that contain a ketone functional group and have the molecular formula C4H8O. They are also known as methyl ethyl ketones or MEKs. The simplest butanone is called methyl ethyl ketone (MEK) or 2-butanone, which has a chain of four carbon atoms with a ketone group in the second position. Other butanones include diethyl ketone (3-pentanone), which has a ketone group in the third position, and methyl isobutyl ketone (MIBK) or 4-methyl-2-pentanone, which has a branched chain with a ketone group in the second position.

Butanones are commonly used as solvents in various industrial applications, such as paint thinners, adhesives, and cleaning agents. They have a characteristic odor and can be harmful if ingested or inhaled in large quantities. Exposure to butanones can cause irritation of the eyes, skin, and respiratory tract, and prolonged exposure may lead to neurological symptoms such as dizziness, headache, and nausea.

Urinary bladder calculi, also known as bladder stones, refer to the formation of solid mineral deposits within the urinary bladder. These calculi develop when urine becomes concentrated, allowing minerals to crystallize and stick together, forming a stone. Bladder stones can vary in size, ranging from tiny sand-like particles to larger ones that can occupy a significant portion of the bladder's volume.

Bladder stones typically form as a result of underlying urinary tract issues, such as bladder infection, enlarged prostate, nerve damage, or urinary retention. Symptoms may include lower abdominal pain, difficulty urinating, frequent urination, blood in the urine, and sudden, strong urges to urinate. If left untreated, bladder stones can lead to complications like urinary tract infections and kidney damage. Treatment usually involves surgical removal of the stones or using other minimally invasive procedures to break them up and remove the fragments.

The urinary bladder is a muscular, hollow organ in the pelvis that stores urine before it is released from the body. It expands as it fills with urine and contracts when emptying. The typical adult bladder can hold between 400 to 600 milliliters of urine for about 2-5 hours before the urge to urinate occurs. The wall of the bladder contains several layers, including a mucous membrane, a layer of smooth muscle (detrusor muscle), and an outer fibrous adventitia. The muscles of the bladder neck and urethra remain contracted to prevent leakage of urine during filling, and they relax during voiding to allow the urine to flow out through the urethra.

Isothiocyanates are organic compounds that contain a functional group made up of a carbon atom, a nitrogen atom, and a sulfur atom, with the formula RN=C=S (where R can be an alkyl or aryl group). They are commonly found in cruciferous vegetables such as broccoli, brussels sprouts, and wasabi. Isothiocyanates have been studied for their potential health benefits, including their anticancer and anti-inflammatory properties. However, they can also be toxic in high concentrations.

Silica gel is not typically considered a medical term, but it is often used in medical contexts. Silica gel is a form of silicon dioxide (SiO2), which is a naturally occurring mineral. It is usually produced in a porous form, with a large surface area and high absorption capacity.

In the medical field, silica gel is sometimes used as a desiccant in packaging to protect sterile medical supplies from moisture during storage and transportation. This helps maintain the sterility of the products and ensures their effectiveness when they are used. Silica gel can also be found in some medical devices, such as wound dressings, where it can help absorb excess exudate and maintain a moist environment that promotes healing.

It is important to note that silica gel should not be ingested or inhaled, as it can cause irritation to the respiratory and gastrointestinal tracts.

Aminopyrine is a type of medication known as a non-opioid analgesic, which is used to relieve pain and reduce fever. It is an antipyretic and analgesic drug that was widely used in the past, but its use has been limited or discontinued in many countries due to the risk of rare but serious side effects such as agranulocytosis (a severe decrease in white blood cells), which can make individuals more susceptible to infections.

Chemically, aminopyrine is an aromatic heterocyclic compound containing a pyridine ring substituted with an amino group and a phenyl group. It works by inhibiting the enzyme cyclooxygenase (COX), which is involved in the production of prostaglandins, chemicals that mediate pain and inflammation. By reducing prostaglandin levels, aminopyrine helps to alleviate pain and reduce fever.

It's important to note that due to its potential side effects, aminopyrine is not commonly used in modern medical practice, and other safer and more effective medications are available for pain relief and fever reduction.

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.

Cotinine is the major metabolite of nicotine, which is formed in the body after exposure to tobacco smoke or other sources of nicotine. It is often used as a biomarker for nicotine exposure and can be measured in various biological samples such as blood, urine, saliva, and hair. Cotinine has a longer half-life than nicotine, making it a more reliable indicator of long-term exposure to tobacco smoke or nicotine products.

Sodium nitrite is an inorganic compound with the chemical formula NaNO2. Medically, it is used as a vasodilator and an antidote for cyanide poisoning. It is a white to slightly yellowish crystalline powder that is very soluble in water and moderately soluble in alcohol. In solution, it is easily oxidized to sodium nitrate (NaNO3), which is stable and less toxic.

In the food industry, sodium nitrite is used as a preservative and coloring agent in meat and fish products. It helps prevent the growth of harmful bacteria, such as Clostridium botulinum, which can cause botulism. However, under certain conditions, sodium nitrite can react with proteins in food to form potentially carcinogenic compounds, so its use is regulated.

"Food Legislation" refers to laws, regulations, and policies related to food production, distribution, labeling, safety, and marketing. These rules are designed to protect consumers from fraudulent or unsafe food practices, promote fair trade in the food industry, and ensure that food is produced and distributed in a sustainable and environmentally friendly manner. Food legislation can cover a wide range of issues, including foodborne illness outbreaks, pesticide residues, organic farming, genetically modified foods, and nutrition labeling. Compliance with food legislation is typically enforced by government agencies, such as the US Department of Agriculture (USDA), the Food and Drug Administration (FDA), and the Federal Trade Commission (FTC) in the United States.

Food additives are substances that are added to food or drink during manufacturing or processing to perform various functions such as preservation, coloring, flavoring, enhancing taste and texture, and increasing nutritional value. These additives can be natural or synthetic and must be approved by regulatory authorities before they can be used in food products. Examples of food additives include salt, sugar, vinegar, spices, artificial flavors, preservatives, emulsifiers, and food dyes. It is important to note that some people may have allergies or sensitivities to certain food additives, and excessive consumption of some additives may have negative health effects.

Volatilization, in the context of pharmacology and medicine, refers to the process by which a substance (usually a medication or drug) transforms into a vapor state at room temperature or upon heating. This change in physical state allows the substance to evaporate and be transferred into the air, potentially leading to inhalation exposure.

In some medical applications, volatilization is used intentionally, such as with essential oils for aromatherapy or topical treatments that utilize a vapor action. However, it can also pose concerns when volatile substances are unintentionally released into the air, potentially leading to indoor air quality issues or exposure risks.

It's important to note that in clinical settings, volatilization is not typically used as a route of administration for medications, as other methods such as oral, intravenous, or inhalation via nebulizers are more common and controlled.

"Food analysis" is not a medical term per se, but it falls under the broader field of food science and nutrition. Food analysis refers to the laboratory methods and techniques used to determine the composition and quality of food products. This can include testing for nutrients (such as proteins, fats, carbohydrates, vitamins, and minerals), contaminants (like heavy metals, pesticides, or allergens), and other components that may affect the safety, quality, or authenticity of food.

The results of food analysis can be used to ensure compliance with regulatory standards, develop new food products, assess the nutritional value of diets, investigate food-borne illnesses, and monitor trends in food consumption. While not a medical definition, food analysis is an important tool for promoting public health and preventing diet-related diseases.

I'm sorry for any confusion, but "Pyridines" is not a medical term. It is a chemical term that refers to a class of organic compounds with the chemical structure of a six-membered ring containing one nitrogen atom and five carbon atoms (heterocyclic aromatic compound).

In a biological or medical context, pyridine derivatives can be found in various natural and synthetic substances. For example, some medications contain pyridine rings as part of their chemical structure. However, "Pyridines" itself is not a medical term or condition.

Respiratory tract neoplasms refer to abnormal growths or tumors that occur in the respiratory system, which includes the nose, throat (pharynx), voice box (larynx), windpipe (trachea), bronchi, and lungs. These growths can be benign or malignant (cancerous). Malignant neoplasms are cancerous tumors that can invade nearby tissues, spread to other parts of the body, and interfere with normal respiratory function, leading to serious health consequences.

Respiratory tract neoplasms can have various causes, including genetic factors, exposure to environmental carcinogens such as tobacco smoke, asbestos, and radon, and certain viral infections. Symptoms of respiratory tract neoplasms may include coughing, wheezing, shortness of breath, chest pain, hoarseness, or blood in the sputum. Diagnosis typically involves imaging tests such as X-rays, CT scans, or PET scans, as well as biopsies to determine the type and extent of the tumor. Treatment options may include surgery, radiation therapy, chemotherapy, targeted therapy, or a combination of these approaches.

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.

Lung neoplasms refer to abnormal growths or tumors in the lung tissue. These tumors can be benign (non-cancerous) or malignant (cancerous). Malignant lung neoplasms are further classified into two main types: small cell lung carcinoma and non-small cell lung carcinoma. Lung neoplasms can cause symptoms such as cough, chest pain, shortness of breath, and weight loss. They are often caused by smoking or exposure to secondhand smoke, but can also occur due to genetic factors, radiation exposure, and other environmental carcinogens. Early detection and treatment of lung neoplasms is crucial for improving outcomes and survival rates.

Anticarcinogenic agents are substances that prevent, inhibit or reduce the development of cancer. They can be natural or synthetic compounds that interfere with the process of carcinogenesis at various stages, such as initiation, promotion, and progression. Anticarcinogenic agents may work by preventing DNA damage, promoting DNA repair, reducing inflammation, inhibiting cell proliferation, inducing apoptosis (programmed cell death), or modulating immune responses.

Examples of anticarcinogenic agents include chemopreventive agents, such as nonsteroidal anti-inflammatory drugs (NSAIDs) and retinoids; phytochemicals found in fruits, vegetables, and other plant-based foods; and medications used to treat cancer, such as chemotherapy, radiation therapy, and targeted therapies.

It is important to note that while some anticarcinogenic agents have been shown to be effective in preventing or reducing the risk of certain types of cancer, they may also have potential side effects and risks. Therefore, it is essential to consult with a healthcare professional before using any anticarcinogenic agent for cancer prevention or treatment purposes.

"Mesocricetus" is a genus of rodents, more commonly known as hamsters. It includes several species of hamsters that are native to various parts of Europe and Asia. The best-known member of this genus is the Syrian hamster, also known as the golden hamster or Mesocricetus auratus, which is a popular pet due to its small size and relatively easy care. These hamsters are burrowing animals and are typically solitary in the wild.

Guanine is not a medical term per se, but it is a biological molecule that plays a crucial role in the body. Guanine is one of the four nucleobases found in the nucleic acids DNA and RNA, along with adenine, cytosine, and thymine (in DNA) or uracil (in RNA). Specifically, guanine pairs with cytosine via hydrogen bonds to form a base pair.

Guanine is a purine derivative, which means it has a double-ring structure. It is formed through the synthesis of simpler molecules in the body and is an essential component of genetic material. Guanine's chemical formula is C5H5N5O.

While guanine itself is not a medical term, abnormalities or mutations in genes that contain guanine nucleotides can lead to various medical conditions, including genetic disorders and cancer.

Transitional cell carcinoma (TCC) is a type of cancer that develops in the transitional epithelium, which is the tissue that lines the inner surface of the urinary tract. This includes the renal pelvis, ureters, bladder, and urethra. Transitional cell carcinoma is the most common type of bladder cancer and can also occur in other parts of the urinary system.

Transitional cells are specialized epithelial cells that can stretch and change shape as the organs they line expand or contract. These cells normally have a flat, squamous appearance when at rest but become more cuboidal and columnar when the organ is full. Transitional cell carcinomas typically start in the urothelium, which is the innermost lining of the urinary tract.

Transitional cell carcinoma can be classified as non-invasive (also called papillary or superficial), invasive, or both. Non-invasive TCCs are confined to the urothelium and have not grown into the underlying connective tissue. Invasive TCCs have grown through the urothelium and invaded the lamina propria (a layer of connective tissue beneath the urothelium) or the muscle wall of the bladder.

Transitional cell carcinoma can also be categorized as low-grade or high-grade, depending on how abnormal the cancer cells look under a microscope and how likely they are to grow and spread. Low-grade TCCs tend to have a better prognosis than high-grade TCCs.

Treatment for transitional cell carcinoma depends on the stage and grade of the cancer, as well as other factors such as the patient's overall health. Treatment options may include surgery, radiation therapy, chemotherapy, or immunotherapy.

In a medical context, "meat" generally refers to the flesh of animals that is consumed as food. This includes muscle tissue, as well as fat and other tissues that are often found in meat products. However, it's worth noting that some people may have dietary restrictions or medical conditions that prevent them from consuming meat, so it's always important to consider individual preferences and needs when discussing food options.

It's also worth noting that the consumption of meat can have both positive and negative health effects. On the one hand, meat is a good source of protein, iron, vitamin B12, and other essential nutrients. On the other hand, consuming large amounts of red and processed meats has been linked to an increased risk of heart disease, stroke, and certain types of cancer. Therefore, it's generally recommended to consume meat in moderation as part of a balanced diet.

Beer is a fermented alcoholic beverage typically made from malted barley, hops, water, and yeast. The brewing process involves steeping the malt in water to create a sugary solution called wort, which is then boiled with hops for flavor and preservation. After cooling, the wort is fermented with yeast, which converts the sugar into alcohol and carbon dioxide. There are many varieties of beer, including ales, lagers, stouts, and porters, that differ in their ingredients, brewing methods, and flavor profiles. The alcohol content of beer generally ranges from 3% to 12% ABV (alcohol by volume).

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.

"p-Dimethylaminoazobenzene" is not a term that has a specific medical definition. However, it is a chemical compound that can have potential medical relevance. Here is its general chemical definition:

"p-Dimethylaminoazobenzene" (also known as "para-dimethylaminoazobenzene" or "DMAB") is an aromatic organic compound, which is a derivative of azobenzene by the introduction of a dimethylamino group in the para position. It is a yellow to orange crystalline powder that is soluble in alcohol and ether but insoluble in water.

In the field of medical research, "p-Dimethylaminoazobenzene" has been used as a model compound for studying chemical carcinogenesis, or the process by which certain chemicals can cause cancer. This compound has been shown to induce liver tumors in experimental animals, and its use in research has contributed to our understanding of the mechanisms involved in chemical carcinogenesis. However, it is not used as a therapeutic agent or diagnostic tool in human medicine.

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.

Smoking is not a medical condition, but it's a significant health risk behavior. Here is the definition from a public health perspective:

Smoking is the act of inhaling and exhaling the smoke of burning tobacco that is commonly consumed through cigarettes, pipes, and cigars. The smoke contains over 7,000 chemicals, including nicotine, tar, carbon monoxide, and numerous toxic and carcinogenic substances. These toxins contribute to a wide range of diseases and health conditions, such as lung cancer, heart disease, stroke, chronic obstructive pulmonary disease (COPD), and various other cancers, as well as adverse reproductive outcomes and negative impacts on the developing fetus during pregnancy. Smoking is highly addictive due to the nicotine content, which makes quitting smoking a significant challenge for many individuals.

Alkylating agents are a class of chemotherapy drugs that work by alkylating, or adding an alkyl group to, DNA molecules. This process can damage the DNA and prevent cancer cells from dividing and growing. Alkylating agents are often used to treat various types of cancer, including Hodgkin's lymphoma, non-Hodgkin's lymphoma, multiple myeloma, and solid tumors. Examples of alkylating agents include cyclophosphamide, melphalan, and chlorambucil. These drugs can have significant side effects, including nausea, vomiting, hair loss, and an increased risk of infection. They can also cause long-term damage to the heart, lungs, and reproductive system.

Glucuronates are not a medical term per se, but they refer to salts or esters of glucuronic acid, a organic compound that is a derivative of glucose. In the context of medical and biological sciences, glucuronidation is a common detoxification process in which glucuronic acid is conjugated to a wide variety of molecules, including drugs, hormones, and environmental toxins, to make them more water-soluble and facilitate their excretion from the body through urine or bile.

The process of glucuronidation is catalyzed by enzymes called UDP-glucuronosyltransferases (UGTs), which are found in various tissues, including the liver, intestines, and kidneys. The resulting glucuronides can be excreted directly or further metabolized before excretion.

Therefore, "glucuronates" can refer to the chemical compounds that result from this process of conjugation with glucuronic acid, as well as the therapeutic potential of enhancing or inhibiting glucuronidation for various clinical applications.

Microsomes, liver refers to a subcellular fraction of liver cells (hepatocytes) that are obtained during tissue homogenization and subsequent centrifugation. These microsomal fractions are rich in membranous structures known as the endoplasmic reticulum (ER), particularly the rough ER. They are involved in various important cellular processes, most notably the metabolism of xenobiotics (foreign substances) including drugs, toxins, and carcinogens.

The liver microsomes contain a variety of enzymes, such as cytochrome P450 monooxygenases, that are crucial for phase I drug metabolism. These enzymes help in the oxidation, reduction, or hydrolysis of xenobiotics, making them more water-soluble and facilitating their excretion from the body. Additionally, liver microsomes also host other enzymes involved in phase II conjugation reactions, where the metabolites from phase I are further modified by adding polar molecules like glucuronic acid, sulfate, or acetyl groups.

In summary, liver microsomes are a subcellular fraction of liver cells that play a significant role in the metabolism and detoxification of xenobiotics, contributing to the overall protection and maintenance of cellular homeostasis within the body.

Experimental liver neoplasms refer to abnormal growths or tumors in the liver that are intentionally created or manipulated in a laboratory setting for the purpose of studying their development, progression, and potential treatment options. These experimental models can be established using various methods such as chemical induction, genetic modification, or transplantation of cancerous cells or tissues. The goal of this research is to advance our understanding of liver cancer biology and develop novel therapies for liver neoplasms in humans. It's important to note that these experiments are conducted under strict ethical guidelines and regulations to minimize harm and ensure the humane treatment of animals involved in such studies.

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.

Hydroxylation is a biochemical process that involves the addition of a hydroxyl group (-OH) to a molecule, typically a steroid or xenobiotic compound. This process is primarily catalyzed by enzymes called hydroxylases, which are found in various tissues throughout the body.

In the context of medicine and biochemistry, hydroxylation can have several important functions:

1. Drug metabolism: Hydroxylation is a common way that the liver metabolizes drugs and other xenobiotic compounds. By adding a hydroxyl group to a drug molecule, it becomes more polar and water-soluble, which facilitates its excretion from the body.
2. Steroid hormone biosynthesis: Hydroxylation is an essential step in the biosynthesis of many steroid hormones, including cortisol, aldosterone, and the sex hormones estrogen and testosterone. These hormones are synthesized from cholesterol through a series of enzymatic reactions that involve hydroxylation at various steps.
3. Vitamin D activation: Hydroxylation is also necessary for the activation of vitamin D in the body. In order to become biologically active, vitamin D must undergo two successive hydroxylations, first in the liver and then in the kidneys.
4. Toxin degradation: Some toxic compounds can be rendered less harmful through hydroxylation. For example, phenol, a toxic compound found in cigarette smoke and some industrial chemicals, can be converted to a less toxic form through hydroxylation by enzymes in the liver.

Overall, hydroxylation is an important biochemical process that plays a critical role in various physiological functions, including drug metabolism, hormone biosynthesis, and toxin degradation.

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.

Methylnitrosourea (MNU) is not a medical term per se, but it is a chemical compound that has been widely used in biomedical research, particularly in cancer studies. Therefore, I will provide you with a scientific definition of this compound.

Methylnitrosourea (MNU) is an alkylating agent and a nitrosourea compound. It is known to be highly mutagenic and carcinogenic. MNU acts by transferring its methyl group (-CH3) to DNA, RNA, and proteins, causing damage to these macromolecules. This methylation can lead to point mutations, chromosomal aberrations, and DNA strand breaks, which contribute to genomic instability and cancer initiation and progression.

In research settings, MNU has been used as a model carcinogen to induce tumors in various animal models, primarily rodents, to study the mechanisms of carcinogenesis and evaluate potential chemopreventive or therapeutic agents. However, due to its high toxicity and mutagenicity, handling and use of MNU require strict safety measures and precautions.

Esophageal neoplasms refer to abnormal growths in the tissue of the esophagus, which is the muscular tube that connects the throat to the stomach. These growths can be benign (non-cancerous) or malignant (cancerous). Malignant esophageal neoplasms are typically classified as either squamous cell carcinomas or adenocarcinomas, depending on the type of cell from which they originate.

Esophageal cancer is a serious and often life-threatening condition that can cause symptoms such as difficulty swallowing, chest pain, weight loss, and coughing. Risk factors for esophageal neoplasms include smoking, heavy alcohol consumption, gastroesophageal reflux disease (GERD), and Barrett's esophagus. Treatment options may include surgery, radiation therapy, chemotherapy, or a combination of these approaches.

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.

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.

Hyperplasia is a medical term that refers to an abnormal increase in the number of cells in an organ or tissue, leading to an enlargement of the affected area. It's a response to various stimuli such as hormones, chronic irritation, or inflammation. Hyperplasia can be physiological, like the growth of breast tissue during pregnancy, or pathological, like in the case of benign or malignant tumors. The process is generally reversible if the stimulus is removed. It's important to note that hyperplasia itself is not cancerous, but some forms of hyperplasia can increase the risk of developing cancer over time.

Tobacco smoke pollution is not typically defined in medical terms, but it refers to the presence of tobacco smoke in indoor or outdoor environments, which can have negative effects on air quality and human health. It is also known as secondhand smoke or environmental tobacco smoke (ETS). This type of smoke is a mixture of sidestream smoke (the smoke given off by a burning cigarette) and mainstream smoke (the smoke exhaled by a smoker).

The medical community recognizes tobacco smoke pollution as a serious health hazard. It contains more than 7,000 chemicals, hundreds of which are toxic and about 70 that can cause cancer. Exposure to tobacco smoke pollution can cause a range of adverse health effects, including respiratory symptoms, lung cancer, heart disease, and stroke. In children, it can also lead to ear infections, asthma attacks, and sudden infant death syndrome (SIDS).

Therefore, many laws and regulations have been implemented worldwide to protect people from tobacco smoke pollution, such as smoking bans in public places and workplaces.

A precancerous condition, also known as a premalignant condition, is a state of abnormal cellular growth and development that has a higher-than-normal potential to progress into cancer. These conditions are characterized by the presence of certain anomalies in the cells, such as dysplasia (abnormal changes in cell shape or size), which can indicate an increased risk for malignant transformation.

It is important to note that not all precancerous conditions will eventually develop into cancer, and some may even regress on their own. However, individuals with precancerous conditions are often at a higher risk of developing cancer compared to the general population. Regular monitoring and appropriate medical interventions, if necessary, can help manage this risk and potentially prevent or detect cancer at an early stage when it is more treatable.

Examples of precancerous conditions include:

1. Dysplasia in the cervix (cervical intraepithelial neoplasia or CIN)
2. Atypical ductal hyperplasia or lobular hyperplasia in the breast
3. Actinic keratosis on the skin
4. Leukoplakia in the mouth
5. Barrett's esophagus in the digestive tract

Regular medical check-ups, screenings, and lifestyle modifications are crucial for individuals with precancerous conditions to monitor their health and reduce the risk of cancer development.

Nitrosation is a chemical reaction that involves the addition of a nitrosonium ion (NO+) to another molecule. In the context of medicine, particularly in relation to gastroenterology and oncology, nitrosation is often discussed in terms of its potential role in the formation of carcinogenic N-nitroso compounds (NOCs).

These NOCs can be formed when nitrites (compounds containing a nitrite ion, NO2-) or nitrous acid (HNO2) react with secondary amines or other amino compounds under acidic conditions. This reaction can occur in the stomach after the ingestion of foods or beverages that contain both nitrites and amines, such as processed meats and certain alcoholic beverages.

The formation of NOCs has been associated with an increased risk of various types of cancer, including gastric and esophageal cancer. However, it's important to note that the relationship between nitrosation and cancer is complex and not fully understood, as other factors such as the presence of antioxidants in the diet can also influence the formation of NOCs.

Among the tobacco-specific nitrosamines, nicotine-derived nitrosamine ketone (NNK) and N-nitrosonornicotine (NNN) are the most ... The tobacco-specific nitrosamines are present in cigarette smoke and to a lesser degree in "smokeless" tobacco products such as ... These nitrosamine carcinogens are formed from nicotine and related compounds by a nitrosation reaction that occurs during the ... Tobacco-specific nitrosamines (TSNAs) comprise one of the most important groups of carcinogens in tobacco products, ...
Nitrosamines/ethers/alcohols. Nitrosamines are a group of organic chemicals formed by the interaction of nitrites with amines ...
Weve got the unique capabilities to help mitigate the risk of nitrosamine formation in your drug product. Partner with DSM to ... Nitrosamines are potential mutagens and need to be controlled in human drug products. Recently, nitrosamine contamination of ... Explore viable strategies to confidently address nitrosamine risk mitigation. Nitrosamine risk mitigation is a huge challenge ... We have the scientific know-how and cutting-edge technology you need to mitigate the risk of nitrosamines in your oral solid, ...
Nitrosamines in nipples at levels greater than an established action level are considered avoidable contamination under section ... A German study on the occurrence of volatile N-nitrosamines (nitrosamines) in rubber baby bottle nipples was presented at the ... Nitrosamines in nipples at levels greater than an established action level are considered avoidable contamination under section ... The level of any individual volatile N-nitrosamine in each of 3 aliquots from a composite of 12 rubber baby bottle nipples ...
Determination of tobacco specific nitrosamines - Method using alkaline dichloromethane extraction ... ISO/TS 22304:2008 specifies the procedure for the determination of the tobacco specific nitrosamines (TSNAs): N- ...
Most Nitrosamines are Carcinogenic. MacLellan European Manufactured EU1935 Grades of Rubber Sheeting are certified Nitrosamine ... Nitrosamines are used in the manufacture of some cosmetics, pesticides, and in some rubber products. ... Nitrosamines. Nitrosamines are used in the manufacture of some cosmetics, pesticides, and in some rubber products. Most ... MacLellan European Manufactured EU1935 Grades of Rubber Sheeting are certified Nitrosamine Free.. Related Products. 0128 ...
by APFLI , Jun 22, 2004 , Birth Control Archive. The Chemical and Veterinary Investigation Institute in Stuttgart [scientific research] has warned that most condoms on the market contain a cancer-causing chemical and has urged that their production have stringent quality control. The institute found the carcinogen ...
Do e-cigarettes contain nitrosamines, and if so is it enough to cause cancer? ... Nitrosamines in vapour. But thats not all. The FDA only tested the contents of e-cigarettes for nitrosamines, not the vapor ... Nitrosamines in tobacco cigarettes v. nitrosamines in vape devices. According to studies conducted, most e-cigarettes dont ... the nitrosamines found were below recommended guidelines. *nitrosamines were also at levels 14,000 times lower than those found ...
When referring to this article, please cite it as T. Curran and J.P. Bercu, Managing the Risk of Nitrosamine Impurities, ... industry efforts have shed light on ways industry standards can help pharma companies better understand the risks nitrosamines ...
The consortium also aims to use the data to improve structure-activity relationships (SARs) for complex nitrosamines. ... The Vitic Complex Nitrosamines data sharing initiative consists of a consortium and a database. ... Complex Nitrosamines, Data sharing, In silico mutagenicity assessment, Nitrites, Nitrosamine impurity risk assessment ... In response to the nitrosamine impurity crisis within the pharmaceutical industry, the Complex Nitrosamines data sharing ...
... nitrosamine (BBN) were evaluated. Male F344 rats were given 0.01% BBN in their drinking water for 4 weeks and then the test ... Effects of three sweeteners on rat urinary bladder carcinogenesis initiated by N-butyl-N-(4-hydroxybutyl)-nitrosamine Gan. 1984 ... nitrosamine (BBN) were evaluated. Male F344 rats were given 0.01% BBN in their drinking water for 4 weeks and then the test ...
Identification of Tobacco-Specific Nitrosamines as Disinfection Byproducts in Chloraminated Water (link ... Emerging Contaminants: Nitrosamine Formation & Monitoring. By AnalyteGuru Staff, 07.13.2015 A recent journal article that I ... A group of DBPs are nitrosamines (link to downloadable PDF), many of which have been identified and measured in the effluent of ... The second part of the webinar presents data from the Orange County Water District where eight nitrosamines, 1, 4-dioxane and ...
Nitrosamines refer to any molecule containing the nitroso functional group. These molecules are of concern because nitrosamine ... Nitrosamines impurities can be derived from several potential sources which include but is not limited to:. *During API ... Nitrosamines refer to any molecule containing the nitroso functional group. The MAH together with API and finished product ... Nitrosamine impurities have been in the regulatory spotlight since they were discovered in several blood pressure medicines ...
The control of nitrosamine formation is essential to ensure the safety and efficacy of pharmaceutical products. Nitrosamines ... However, the presence of these compounds can lead to the formation of potentially carcinogenic nitrosamines. Nitrosamines are ... Nitrite and nitrate analysis is important in controlling nitrosamine formation as it helps to monitor the levels of these ... including nitrosamines. Our cross-laboratory, multi-disciplinary approach make us an ideal analytical support partner. ...
Regulatory and analytical aspects of determining mutagenic impurities, including nitrosamines, will also be consider. ... Trace impurities in Pharmaceutical Products: Nitrosamines and beyond. .social-ris-container { display: flex; justify-content: ... challenges of detection and quantification of trace level impurities in pharmaceutical products including mutagenic nitrosamine ...
This on-demand webinar details a qualified automated approach to nitrosamine testing in products, which simultaneously prepares ... New technology can be assessed to automate the sample preparation process for nitrosamine testing. This provides a higher ... This on-demand webinar details a qualified automated approach to nitrosamine testing in products, which simultaneously prepares ...
The reason is that risk assessments for the presence of nitrosamines in active substances should be available early enough to ... on how to avoid the presence of nitrosamines in human medicinal products. As part of the outcome of this review, the European ... as well as in any revision where a risk of nitrosamine formation may be introduced (i.e. changes to the manufacturing process, ... applicants and CEP holders should systematically include a risk assessment regarding the potential formation of nitrosamines in ...
Nitrosamines are known as possible carcinogens for humans: only very low amounts are acceptable according to current regulatory ... certain types of nitrosamines (N‑nitrosodiethylamine (NDEA) and N-nitrosodimethylamine (NDMA)) were detected in a number of ... Remember nitrosamines…a few dates:. July 2018: Investigation of nitrosamine impurities in valsartan ... N-nitrosamine impurities in Ph. Eur. monographs: update on approach EDQM Strasbourg, France 24/07/2023 ...
... highly sensitive quantitation of nine nitrosamines with LC-MS measuring impurities in commercially available ranitidine drug ... To demonstrate fast, highly sensitive quantitation of nine nitrosamines with LC-MS measuring impurities in commercially ... HRAM LC-MS Method for Determination of Drug Nitrosamine impurities .social-ris-container { display: flex; justify-content: ...
Read the full LAC DPH Health Advisory: Rifapentine Shortage and Detection of Nitrosamine Impurity. ... has increased and because the sole manufacturer has voluntarily paused release of the drug due to the detection of nitrosamine ...
ILT-U-1991 - N-nitrosamines and N-nitrosatables in latex baby pacifier. ...
Previous studies showed that streptozotocin, a nitrosamine-related compound, cause ...
Free 1-hr online "Live" CE Webinar on FDA Drug Topics: Nitrosamine Impurities in Drugs: What Health Care Professionals Need to ... This educational activity will provide an overview of nitrosamine impurities identified in several prescription and over-the- ... The presentation will include background information on nitrosamines, a discussion of pharmaceutical quality, FDAs role in ...
The FDA does not expect nitrosamines to cause harm when ingested at or below the acceptable intake limit levels (such low ... The FDA has previously investigated the presence of nitrosamines in the U.S. drug supply. The investigation began with the ... The FDA is taking a systematic approach to identify medicines with nitrosamines above the acceptable intake limit and remove ... FDA Alerts Patients and Health Care Professionals to Nitrosamine Impurity Findings in Certain Metformin Extended-Release ...
Tobacco-specific n-nitrosamines and Areca-derived n-nitrosamines: chemistry, biochemistry, carcinogenicity, and relevance to ... Effect of Ordering Method on Tobacco-Specific Nitrosamines (TSNAs) Content in Dark Air-Cured and Burley Tobacco Mitchell D. ... Tobacco-specific nitrosamines (TSNAs) are known carcinogens in cured tobacco. They are produced primarily during the curing ... Effect of Potassium Source and Rate on Yield, Quality, and Tobacco-Specific Nitrosamines in Dark and Burley Tobacco Andrea B. ...
McCutcheon, J W "Nitrosamines In Bacon: A Case Study Of Balancing Risks" 99, no. 4 (1984). McCutcheon, J W "Nitrosamines In ... Title : Nitrosamines In Bacon: A Case Study Of Balancing Risks Personal Author(s) : McCutcheon, J W Published Date : 07/01/1984 ... To deal with the nitrosamine problem, the U.S. Department of Agriculture (USDA) lowered the permissible amount of nitrite in ... Regulators, however, found it necessary to take additional steps with bacon because nitrosamines were found consistently in ...
API index of Reference standards of Nitrosamine compounds. ...
... we have practical experience with twenty-four Nitrosamines, including nitrosamine analogues, which confirms the versatility of ... Get in touch with one of our Nitrosamine experts today, or use the contact information for our commercial team below, and see ... There is a dedicated cross-functional team dedicated to the Nitrosamines project which assures tailoring the project scope to ... We provide unparalleled risk evaluations which can identify active substances and finished products at risk of N-nitrosamine ...
Over time, the focus on nitrosamine determination has expanded to include not only the seven basic nitrosamines but also those ... there is a wide range of possibilities for the formation of this type of nitrosamine. These nitrosamines are classified as ... there has been increased scrutiny of drug products for nitrosamines impurities. Nitrosamines are a type of impurity that belong ... API derived nitrosamine. 0.45 ng/mL. LCMS-QQQ. Glatimer acetate. API. NDMA; NMBA; NDEA; NDBA; NMPA; NEIPA; NDIPA. 0.7 ng/mL; 10 ...
Better models to shed light on the mutagenicity of N-nitrosamines. * COVID-19 Research Network Lower Saxony: Pooling expertise ... Press Release from 28/01/2022: Better models to shed light on the mutagenicity of N-nitrosamines ... due to detection of low levels of impurities consisting of N-nitrosamines (NAs). NAs are considered potent carcinogens with a ... Research aimed at predicting the carcinogenic potency of different nitrosamines ...

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