What's the difference between lecithin and membrane?

Lecithin


Definition:

  • (n.) A complex, nitrogenous phosphorized substance widely distributed through the animal body, and especially conspicuous in the brain and nerve tissue, in yolk of eggs, and in the white blood corpuscles.

Example Sentences:

  • (1) We similarly evaluated the ability of other phospholipids to form stable foam at various concentrations and ethanol volume fractions and found: bovine brain sphingomyelin greater than dipalmitoyl 3-sn-phosphatidylcholine greater than egg sphingomyelin greater than egg lecithin greater than phosphatidylglycerol.
  • (2) These observations suggest that the liver secretes disk-shaped lipid bilayer particles which represent both the nascent form of high density lipoproteins and preferred substrate for lecithin-cholesterol acyltransferase.
  • (3) Saturated acyl residues predominated in lysolecithin and unsaturated ones in acids released by hydrolysis of egg lecithin.
  • (4) The permeability properties of planar lipid bilayers made from egg lecithin, n-decane and a long-chain secondary amine (n-lauryl [trialkylmethyl]amine) are described.
  • (5) In the absence of lipid transfer protein activity in incubations containing purified lecithin: cholesterol acyltransferase, 73% of the esterified [3H]cholesterol was in HDL, 25% in LDL and only 1% in VLDL.
  • (6) perfringens was studied by gel-diffusion in agarose-lecithin gels.
  • (7) Several short-chain asymmetric lecithins with a total of 14 carbons in the acyl chains (ranging from 1-lauroyl-2-acetylphosphatidylcholine to 1-hexanoyl-2-octanoylphosphatidylcholine) have been synthesized and characterized.
  • (8) It was shown that indocyanin green (ICG) test, prothrombin time (PT), lecithin cholesterol acyltransferase (LCAT), gamma-globulin, age of patients and total bilirubin appeared to be important factors to discriminate the subjected patients into two groups.
  • (9) We synthesized lecithinized superoxide dismutase (PC-SOD), in which a lecithin derivative was covalently bound to recombinant human SOD.
  • (10) The high level of serum free cholesterol in the female obese rat is not due to a deficiency in lecithin-cholesterol acyltransferase activity.
  • (11) Mixed micelles (MM) formed from glycocholic acid and lecithin are suited to solubilize lipophilic drugs for intravenous use.
  • (12) Basal lecithin release from placental tissue was unaffected by any steroid concentration.
  • (13) Later, animals exposed to lifelong 5 or 2% soy lecithin preparations were hypoactive, had poor postural reflexes, and showed attenuated morphine analgesia.
  • (14) It has been concluded that purified lecithin: cholesterol acyltransferase is capable of increasing the size of HDL3 towards that of HDL2 but that other factors must operate in vivo to modulate the chemical composition of the enlarged particles.
  • (15) Compared to the group of controls, the group treated with Bromhexine metabolit VIII, as well as to the group treated with Betamethason, significantly higher values with regard to the content of total phospholipids, lecithine and palmitic acid could be found in the fetal rat lungs.
  • (16) In egg lecithin with a variety of polyunsaturated side chains, the side chains with the greater number of double bonds are preferentially displaced by high concentrations of cholesterol, which accounts for the increase in the ratio of outer to inner -N(+)(CH(3))(3) groups.
  • (17) The lecithins of the primary hepatoma induced by 3'-methyl-4-dimethylaminoazobenzene (DAB) and host liver of rat were isolated, and the individual molecular species were estimated quantitatively by combined thin-layer and gaschromatographic analysis and specific enzymic hydrolysis.
  • (18) On lecithin agar, interpretation was easier, phospholipase A was detectable, and opaque zones were visible 1 or 2 days earlier than on egg yolk agar.
  • (19) On the contrary, cell incubation with lecithin liposomes resulted in cholesterol depletion.
  • (20) Both the relative decrease in the mass of disaturated lecithins in the BA washes and the increase in the percentage of esterified unsaturated fatty acids in the lecithins may be directly related to the reduced lung function reported to occur during the course of murine M. pulmonis pneumonia.

Membrane


Definition:

  • (n.) A thin layer or fold of tissue, usually supported by a fibrous network, serving to cover or line some part or organ, and often secreting or absorbing certain fluids.

Example Sentences:

  • (1) Tryptic digestion of the membranes caused complete disappearance of the binding activity, but heat-treatment for 5 min at 70 degrees C caused only 40% loss of activity.
  • (2) The extents of phospholipid hydrolysis were relatively low in brain homogenates, synaptic plasma membranes and heart ventricular muscle.
  • (3) The patterns observed were: clusters of granules related to the cell membrane; positive staining localized to portions of the cell membrane, and, less commonly, the whole cell circumference.
  • (4) Activity of Na,K-ATPase activity was measured as a functional marker for synaptosomal membranes.
  • (5) The influence of the various concepts for the induction of lateral structure formation in lipid membranes on integral functional units like ionophores is demonstrated by analysing the single channel current fluctuations of gramicidin in bimolecular lipid membranes.
  • (6) Phospholipid methylation in human EGMs is distinctly different from that in rat EGMs (Hirata and Axelrod 1980) in that the human activity is not Mg++-dependent, and apparent methyltransferase I activity is located in the external membrane surface.
  • (7) The predicted non-Lorentzian line shapes and widths were found to be in good agreement with experimental results, indicating that the local orientational order (called "packing" by many workers) in the bilayers of small vesicles and in multilamellar membranes is substantially the same.
  • (8) Apparently, the irradiation with visible light of a low intensity creates an additional proton gradient and thus stimulates a new replication and division cycle in the population of cells whose membranes do not have delta pH necessary for the initiation of these processes.
  • (9) Using monoclonal antibodies directed against the plasma membrane of Madin-Darby canine kidney (MDCK) cells, we demonstrated previously that a glycoprotein with an Mr = 23,000 (gp23) had a non-polarized cell surface distribution and was observed on both the apical and basolateral membranes (Ojakian, G. K., Romain, R. E., and Herz, R. E. (1987) Am.
  • (10) The fraction of the viral dose which became cell associated was independent of the incubation temperature and increased with increasing target membrane concentration.
  • (11) Together these results suggest that IVC may operate as a selective activator of calpain both in the cytosol and at the membrane level; in the latter case in synergism with the activation induced by association of the proteinase to the cell membrane.
  • (12) The Cole-Moore effect, which was found here only under a specific set of conditions, thus may be a special case rather than the general property of the membrane.
  • (13) We have examined the insertion of bovine 17 alpha-hydroxylase (P45017 alpha) into the endoplasmic reticulum of COS 1 cells to evaluate the functional role of its hydrophobic amino-terminal sequence and membrane insertion.
  • (14) The transport of potassium ions through membranes of red blood cells was examined in in bitro experiments using a CMF of 4500 oersted.
  • (15) These membrane perturbation effects not observed with bleomycin-iron in the presence of a hydroxyl radical scavenger, dimethyl thiourea, or a chelating agent, desferrioxamine, were correlated with the ability of the complex to generate highly reactive oxygen species.
  • (16) Extensive studies during recent years have shown that the interaction between hormone and membrane-bound receptor can affect the receptor characteristics in at least two ways.
  • (17) Membranes of this material were filled with islets of Langerhans and implanted in the peritoneal cavity of rats.
  • (18) The penicillin-resistant Enterococcus hirae R40 has a typical profile of membrane-bound penicillin-binding proteins (PBPs) except that the 71 kDa PBP5 of low penicillin affinity represents about 50% of all the PBPs present.
  • (19) To investigate the mechanism of enhanced responsiveness of cholesterol-enriched human platelets, we compared stimulation by surface-membrane-receptor (thrombin) and post-receptor (AlF4-) G-protein-directed pathways.
  • (20) Moreover, in DCVC-treated cells the mitochondria could not be stained with rhodamine-123, indicating severe mitochondrial damage and loss of membrane potential.