(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.
Sulfur
Definition:
Example Sentences:
(1) Manometric studies with resting cells obtained by growth on each of these sulfur sources yielded net oxygen uptake for all substrates except sulfite and dithionate.
(2) Typically the iron-iron axis (gz) of the binuclear iron-sulfur clusters is in the membrane plane.
(3) Our study suggests that a major part of the renal antimineralocorticoid activity of spironolactone may be attributable to minor sulfur-containing metabolites or their precursors having a high renal clearance that affords access to their site of activity via the renal tubular fluid.
(4) Ferredoxin reductase (Fd-reductase) supplies reducing equivalents obtained from NADPH to mitochondrial cytochrome P450 enzymes via the small iron-sulfur protein ferredoxin.
(5) The loss of enzyme activity in sulfur-rhodanese does not involve cysteinyl residues but can be correlated with the modification of guanidino groups, notably that of Arg-186, the side chain of which may play a role in substrate binding.
(6) In two patients with extensive marrow necrosis, the diagnosis of marrow necrosis was established by morphologic and radioisotopic studies, and the extent of involvement was accurately assessed by marrow scanning with technetium Tc 99m sulfur colloid while the patients were still alive.
(7) It was presumed that thymohydroquinone is excreted as ethereal sulfuric acid conjugate in man.
(8) Also purple sulfur bacteria lowered BOD levels as demonstrated by the growth of T. floridana in sterilized sewage.
(9) An equivalent maximum growth response of rats fed L-methionine or N-acetyl-L-methionine was obtained when the total dietary sulfur amino acids compromised 0.36-0.41% of the diet.
(10) Histopathological evaluations showed that sulfuric acid particles alone did not cause inflammatory responses in centriacinar units of rat lung parenchyma (expressed in terms of percent lesion area) but did cause significant damage (cell killing followed by a wave of cell replication) in nasal respiratory epithelium, as measured by uptake of tritiated thymidine in the DNA of replicating cells.
(11) Ac-MPS of the hyaluronic acid type prevail in the ground substance of the myxoid and fibroblastic mesenchyma, while the substances containing sulfuric groups predominate in the tissue matrix exhibiting fibrogenic tendencies.
(12) Previous work demonstrated a differential decrease in iron-sulfur centers A, B and X which indicated that center X serves as a branch point for parallel electron flow through centers A and B (Golbeck, J.H.
(13) Our observation leads to the suggestion that, in vivo, either rhodanese is maintained in its more stable sulfur-substituted form or cellular compartmentalization prevents inactivation by nitrite.
(14) In contrast, the (Rp)-isomers, which have an equatorial exocyclic sulfur atom, bound to the enzyme without stimulation of its activity.
(15) A strong shoulder was observed at 2481.7 eV on the low-energy side of the sulfate absorption edge, deriving from a novel type of sulfur having a slightly lower oxidation state than sulfate sulfur.
(16) Long-term treatment with furosemide (up to 13 months) caused transient changes in the elemental content of the pancreatic acinar cells: a decrease in chloride and sulfur, and an increase in phosphorus, potassium and magnesium.
(17) The iron-sulfur proteins of the green photosynthetic bacterium Chlorobium have been characterized by oxidation-reduction potentiometry in conjunction with low-temperature electron paramagnetic resonance spectroscopy.
(18) The reaction is based on the reduction of sulfur dioxide at a dropping mercury electrode.
(19) Proton induced X-ray emission (PIXE) analyses were performed on single hair fibers in triplicate from 103 individuals in order to determine sulfur, zinc, calcium, and chlorine content.
(20) In a survey of the proteins from human hair, a genetic electrophoretic variant has been observed in the high-sulfur protein region.