Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0016382 (flushing)
 6,387 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The industrial use of certain acetamides and formamides (particularly DMAC and DMF) for their solvent properties has resulted in rather extensive examination of their biological properties. Both DMAC and DMF are rapidly absorbed through biological membranes and are metabolized by demethylation first to monomethyl derivatives and then to the parent acetamide or formamide. Relatively high single doses to various species following oral, dermal, i.p., i.v., or inhalation exposures generally are required to produce mortality. The liver is the primary target following acute high level exposure, but massive doses can also produce damage to other organs and tissues. Repeated sublethal treatment by various routes also shows the liver to be the target organ with the degree of damage being proportional to the amount absorbed. With MMF, the potential usefulness as a cancer chemotherapeutic agent needs to be measured against the hepatotoxic effects produced in man. Acetamides and formamides are generally inactive in mutagenicity tests. Mammalian test systems do not appear to be genetically sensitive and DMF has been recommended for use as the vehicle in microbial assays designed to test for genetic activity of hard-to-dissolve chemicals. Embryotoxicity can be demonstrated at high doses; doses which generally show toxicity to the maternal animals. Structural abnormalities in sensitive species such as the rabbit are produced following exposure at near-lethal levels. The spectrum of abnormalities seen is broad and fails to show any time or site specificity in terms of developing organs/organ systems. Inhalation exposures to DMAC and DMF at levels producing some maternal toxicity in rats have produced no teratogenic response and only slight evidence of embryotoxicity. Long-term feeding of relatively high levels of acetamide produces liver cancer in rats. DMAC and DMF appear to be noncarcinogenic. The environmental toxicity of these chemicals is low. Liver damage can be produced by overexposure to these chemicals in man. Airborne concentrations need to be controlled and care should be taken to avoid excessive liquid contact as the chemicals are absorbed through the skin. A relationship exists between the amount of DMAC or DMF absorbed and the amount of MMAC or MMF excreted in the urine so that biomonitoring of the urinary metabolites can indicate situations in which total exposures, both dermal and inhalation, are excessive. An interaction between DMF and ethanol occurs such that signs, including severe facial flushing, appear when DMF-exposed individuals consume alcoholic beverages.
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PMID:Biological effects of acetamide, formamide, and their monomethyl and dimethyl derivatives. 353 Jun 39

A novel method is reported for quantifying protein adsorption to naked silica tubings and for assessing the efficacy of polymers added to the background electrolyte as dynamic wall modifiers. It consisted of flushing a fluorescently-labelled protein (myoglobin) into a capillary equilibrated in Tris-acetate buffer, pH 5.0, until full saturation of the potential adsorbing sites. Desorption was then affected by electrophoretically driving sodium dodecyl sulphate micelles into the capillary from the cathodic reservoir: the peak of eluted material is quantified by using a dual laser beam instrument able to read the fluorescein isothiocyanate-derivatized myoglobin at 520 nm and the internal standard (sulphorodamine) at 630 nm. Four polymers have been assessed as potential quenchers of interaction of proteins with the silica wall: hydroxypropylmethylcellulose (HPMC, Mr = 1000000), hydroxyethylcellulose (HEC, Mr = 27000), poly(vinyl alcohol) (PVA, Mr = 49000) and short-chain poly(dimethylacrylamide) [poly(DMA)] (average Mr ca. 150000). HPMC, poly(DMA) and PVA were effective in the 0.005 to 0.02% (w/v) range, whereas HEC was active in the 0.1 to 0.8% concentration range. All polymers, however, except for poly(DMA), exhibited a rather poor performance in suppressing protein interactions with the siliceous surface, and could inhibit adsorption only by, at most, 50% (contrary to oligoamines which can quench such interactions by >90%). It is hypothesized that dynamically adsorbed polymers leave ample regions of the capillary inner surface unmasked, thus allowing strong interactions of proteins with the silica wall. This is also confirmed by the modest reduction of electroendoosmotic flow upon polymer adsorption, as compared with an untreated silica surface. Although poly(DMA) can inhibit protein adsorption by as much as 85%, its hydrophobic nature could in turn provide more adsorption sites for less hydrophilic proteins than myoglobin.
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PMID:Quantitative studies on the adsorption of proteins to the bare silica wall in capillary electrophoresis. II. Effects of adsorbed, neutral polymers on quenching the interaction. 1081 68

In this work, a new physically adsorbed coating for capillary electrophoresis (CE) is presented. The coating is based on a N,N-dimethylacrylamide-ethylpyrrolidine methacrylate (DMA-EPyM) copolymer synthesized in our laboratory. The capillary coating is simple and easy to obtain as only requires flushing the capillary with a polymer aqueous solution for 2 min. It is shown that by using these coated capillaries the electrostatic adsorption of a group of basic proteins onto the capillary wall is significantly reduced allowing their analysis by CE. Moreover, the DMA-EPyM coating provides reproducible separations of the basic proteins with RSD values for migration times lower than 0.75% for the same day (n = 5) and lower than 3.90% for three different days (n = 15). Interestingly, the electrical charge of the coated capillary wall can be modulated by varying the pH of the running buffer which makes possible the analysis of basic and acidic proteins in the same capillary. The usefulness of this coating is further demonstrated via the reproducible separation of whey (i.e. acidic) proteins from raw milk. The coating protocol should be compatible with both CE in microchips and CE-MS of different types of proteins.
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PMID:New physically adsorbed polymer coating for reproducible separations of basic and acidic proteins by capillary electrophoresis. 1450 46

Two different families of compounds, i.e., phenolic and amino acids have been separated by capillary electrophoresis using a physically adsorbed polymer as capillary coating. The polymer used was N,N-dimethylacrylamide-ethylpyrrolidine methacrylate (DMA-EpyM) and it provided an stable coating by only flushing the capillary with a DMA-EpyM aqueous solution for 2min between runs. The usefulness of this procedure has been demonstrated through the fast analysis of different families of solutes. Two different detection systems, diode-array detector and laser-induced fluorescence, have been used to determine phenolic acids and derivatized amino acids with fluorescein isothiocyanate, respectively. The main factors affecting reversal of electroosmotic flow (EOF) such as pH, type and concentration of buffer, and concentration and influence of organic solvents, as well as all the instrumental conditions were studied and optimized for both families of compounds.
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PMID:Coelectroosmotic capillary electrophoresis of phenolic acids and derivatized amino acids using N,N-dimethylacrylamide-ethylpyrrolidine methacrylate physically coated capillaries. 1907 18

Gas sampling bags have been used for collecting air samples. Tedlar bags are most commonly used, but bleed background chemicals such as N,N-dimethylacetamide and phenol. It is often necessary to remove the contaminant by flushing the bags with pure nitrogen or air. In this study, we identified four chloroprene dimerization products as background contaminants emitted from ALTEF bags that are made of a proprietary polyvinylidene difluoride (PVDF). No monomer chloroprene was detected in the bags analyzed. All of the dimers gradually increased once bags were filled with nitrogen due to diffusion from the bag surface. Flushing the bags with nitrogen reduced their concentrations, but was not effective for removing the contaminants. When the bags that had been flushed with nitrogen 5 times were left for 24 h, they increased again, indicating that the dimers were constantly emitted from the ALTEF bag surface. To our knowledge, these compounds have never been demonstrated in ALTEF or other PVDF bags. Our finding indicates that ALTEF might be incorporated with Neoprene (chloroprene-based polymer) during its manufacturing process.
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PMID:Dimerization Products of Chloroprene are Background Contaminants Emitted from ALTEF (Polyvinylidene Difluoride) Gas Sampling Bags. 2819 Aug 32