(n.) A nitrogenous base, C5H11NO2, produced artificially, and also occurring naturally in beet-root molasses and its residues, from which it is extracted as a white crystalline substance; -- called also lycine and oxyneurine. It has a sweetish taste.
Example Sentences:
(1) Two functions of these have been proposed: 1) that they are compatible osmolytes which regulate cell volume (against high external NaCl) without inhibiting proteins and 2) that methylamines (GPC and betaine) are counteracting osmolytes which stabilize proteins against perturbation from high renal urea.
(2) In superfused precontracted strips of rabbit aorta, methylene blue (MeB) or pyocyanin (Pyo, 1-hydroxy-5-methyl phenazinum betaine) at concentrations of 1-10 microM inhibited relaxations induced by endothelium-derived relaxing factor (EDRF), glyceryl trinitrate (GTN), S-nitroso-N-acetyl-penicillamine (SNAP) or 3-morpholino-sydnonimine (SIN-1).
(3) Despite significant increases in the hepatic levels of betaine-homocysteine methyltransferase and methyltetrahydrofolate-homocysteine methyltransferase, flow through these reactions remains relatively constant.
(4) In the chemically defined medium, acetylcholine, N,N-dimethylethanolamine, and lecithin could replace choline to get normal cell division and cell morphology of C. botulinum type E. Choline could not be replaced by ethanolamine, N-methylethanolamine, or betaine.
(5) Chronic elevation of plasma homocysteine is associated with increased atherogenesis and thrombosis, and can be lowered by betaine (N,N,N-trimethylglycine) treatment which is thought to stimulate activity of the enzyme betaine:homocysteine methyltransferase.
(6) Renal medullary cells contain high concentrations of "compatible" organic osmolytes, such as myo-inositol, betaine, sorbitol, and glycero-phosphorylcholine.
(7) Betaine uptake increased when the osmolality was raised with NaCl or mannitol, but not with urea.
(8) The surface activity of a new potent antimicrobial mixture (C31G) of alkyl betaines and alkyl amine oxides were evaluated in order to determine the relationship between its antimicrobial effectiveness and physical properties.
(9) The results of a study on the interaction between cobalt(II) bovine carbonic anhydrase and the alpha-amino acids L(+) and D(-)alanine, glycine and betaine are reported.
(10) The effect of equimolar doses of glycine (G) and some related amino acids: beta-alanine (A), taurine (T) and betaine (B) on the strychnine syndrome was tested by administering them (intrathecal route) along with strychnine.
(11) The accumulation of either betaine or proline reduces the cytoplasmic amounts of K+, glutamate, trehalose, and MOPS (the major cytoplasmic osmolytes accumulated in the absence of osmoprotectants), so that at this external osmolarity the total amount of cytoplasmic solutes is essentially the same in the presence or absence of either osmoprotectant.
(12) Choline, the hydrolytic product of succinyl choline, is oxidized to betaine aldehyde by choline oxidase (EC 1.1.99.1), a rat liver mitochondrial preparation; this is coupled to the reduction of cytochrome c which is measured at 550 nm.
(13) Following transfer from 920 to 460 mosmol kg-1, Na+, Cl- and proline betaine leave the cells while intracellular K+ is conserved.
(14) 13C labeling studies with Methanogenium cariaci suggested that the betaine which accumulated inside the cells was not synthesized de novo but was transported in from the medium.
(15) Betaine showed a threshold for maximum effect at a concentration of 2 to 5 mM.
(16) The accumulation of glycine betaine to a high internal concentration by Escherichia coli cells in high osmolarity medium restores, within 1 h, a subnormal growth rate.
(17) Foetal heart, lung and kidney tissues also incorporated radiolabelled betaine.
(18) Substitution of the hydroxyl group in choline greatly diminished the inhibitory effect; fluorocholine, thiocholine, betaine, and betaine aldehyde showed little or no inhibition.
(19) In those receiving betaine, methionine concentrations were proportional to the dose administered and S-adenosylmethionine concentrations were near normal.
(20) Considering both the protective effect of glycine betaine (GB) on enteric bacteria grown at high osmolarity and the possible presence of GB in marine sediments, we have analyzed the survival, in nutrient-free seawater, of Escherichia coli cells incubated in sediments supplemented with GB or not supplemented and measured the efficiency of GB uptake systems and the expression of proP and proU genes in both seawater and sediments.
Hydrogen
Definition:
(n.) A gaseous element, colorless, tasteless, and odorless, the lightest known substance, being fourteen and a half times lighter than air (hence its use in filling balloons), and over eleven thousand times lighter than water. It is very abundant, being an ingredient of water and of many other substances, especially those of animal or vegetable origin. It may by produced in many ways, but is chiefly obtained by the action of acids (as sulphuric) on metals, as zinc, iron, etc. It is very inflammable, and is an ingredient of coal gas and water gas. It is standard of chemical equivalents or combining weights, and also of valence, being the typical monad. Symbol H. Atomic weight 1.
Example Sentences:
(1) The hypothesis that proteins are critical targets in free radical mediated cytolysis was tested using U937 mononuclear phagocytes as targets and iron together with hydrogen peroxide to generate radicals.
(2) It has been conformed that catalase from bovine liver eliminates only the pro R hydrogen atom from ethanol.
(3) We investigated the possible contribution made by oropharyngeal microfloral fermentation of ingested carbohydrate to the generation of the early, transient exhaled breath hydrogen rise seen after carbohydrate ingestion.
(4) Hydrogen isotope effects on these mutants indicate that MotA catalyzes proton transfer.
(5) Excessive accumulation of hydrogen ions in the brain may play a pivotal role in initiating the necrosis seen in infarction and following hyperglycemic augmentation of ischemic brain damage.
(6) Studies were conducted in isolated, buffer-perfused rat lungs to determine if prostaglandin (PG) E1 attenuated pulmonary edema provoked by hydrogen peroxide (H2O2).
(7) All N and O atoms except N(3) and O(4') participate in a three-dimensional hydrogen-bonding system.
(8) Both adiphenine.HCl and proadifen.HCl form more stable complexes, suggesting that hydrogen bonding to the carbonyl oxygen by the hydroxyl-group on the rim of the CD ring could be an important contributor to the complexation.
(9) Control mutant S38N has stability essentially the same as that of wild-type lysozyme but hydrogen bonding similar to that of the stabilizing mutant S38D.
(10) High intensity ultrasound also enhances the heterogeneous catalysis of alkene hydrogenation by Ni powders.
(11) An atmosphere of hydrogen eliminates this inhibition in the hydrogenase-containing T. foetus but not in E. invadens which lacks the enzyme.
(12) Vanadate-dependent oxidation of either pyridine nucleotide was inhibited by the addition of either superoxide dismutase or catalase, indicating that both superoxide and hydrogen peroxide may be intermediates in the process.
(13) Our findings suggest that (a) the inclusion of a liquid meal provides a reproducible method of measuring orocaecal transit using the lactulose hydrogen breath test, (b) rapid small bowel transit in thyrotoxicosis may be one factor in the diarrhoea which is a feature of the disease and (c) if altered gut transit is the cause of sluggish bowel habit in hypothyroidism, delay in the colon, and not small bowel, is likely to be responsible.
(14) Stepwise hydrogenation of metal tetradehydrocorrin salts (10 double bonds) yields a series of macrocycles containing 9, 8, 7, 6 and 5 double bonds and conditions necessary to obtain corrins have been established.
(15) For dipeptides containing the amino terminal residues glycine, alanine and phenylalanine, abstraction of the hydrogen from the carbon adjacent to the peptide nitrogen was the major process leading to the spin-adducts.
(16) (7) The first-order radical transformation rates are independent of the (initial) concentration of N3 or peptide and unaffected by urea (as a modifier of hydrogen bond structures).
(17) Intermolecular contacts occur in both oligomers in the minor groove: in the B form through twisted guanine-guanine hydrogen bonding, and in the Z form through base-base stacking and the water network.
(18) Equilibrium-partitioning measurements indicate that the relative affinities of different probes for PC-rich vesicles, in competition with HODMA or DOTAP vesicles, increase with increasing hydrogen-bonding capacity of the probe headgroup in the order PC less than N,N-dimethyl PE less than N-methyl PE less than PE approximately phosphatidyl-2-amino-1-propanol.
(19) When tissue metabolism was irreversibly inhibited by exposure to formaldehyde, hydrogen ion concentration and pCO2 were significantly decreased in the mucosal side of the chamber compared with the viable gall bladder.
(20) Based on the refined atomic coordinates of the tRNAphe in the orthorhombic crystal, on the recent advances in the distance dependence of the ring-current magnetic field effects and on the adopted values for the isolated hydrogen-bonded NH resonances, a computed spectrum consisting of 23 protons was constructed.