| Results 451 - 500 of 1070 | ||
| < 5 6 7 8 9 10 11 12 13 14 15 > | ||
|
Rodrigues C M - - 1996
We recently demonstrated that the formation of delta 22-bile acids is a quantitatively major pathway for normal bile acid synthesis in the adult male Sprague-Dawley rat. This pathway is specific for 7 beta-hydroxy bile acids and, when ursodeoxycholic acid is administered, delta 22-ursodeoxycholic acid appears as a major metabolite in ...
|
||
|
Singh V - - 1996
Glutamate or deoxyuridine in the presence of Cu2+ and delta-aminolevulinic acid (ALA) reaction resulted in the formation of thiobarbituric acid reactive compounds (TBAR), which was linear up to 2 hr. TBAR increased linearly with the increase of both ALA and copper ion concentration. Oxygen consumption was directly proportional to the ...
|
||
|
Lomascolo A - - 1996
The specific activity of the microsomal delta 12-desaturase system, which transforms oleic acid into linoleic acid, was about 16 pmol/min/mg protein. However, most of the total activity was nonsedimentable even after a 200000 x g centrifugation for 100 min. The study of various physicochemical parameters showed that this enzymatic complex, ...
|
||
|
Thorgeirsson T E - - 1996
Amino acids have distinct lipid bilayer affinities which influence the insertion and topology of membrane-bound polypeptides and proteins. To measure membrane affinities, 14 uncharged amino acids were introduced individually at a guest site in a 25-residue peptide derived from the membrane-binding presequence of yeast cytochrome c oxidase, and the peptides ...
|
||
|
Lüönd R M - - 1996
This enzyme porphobilinogen synthase (PBGS) catalyses the formation of porphobilinogen (PBG) from two molecules of 5-amino-levulinic acid (ALA). It has been claimed that the PBGS from Rhodobacter spheroides is able to form a mixed pyrrole, from one molecule of 5-aminolevulinic acid and one molecule of levulinic acid. The chemical synthesis ...
|
||
|
Chardigny J M - - 1996
Trans polyunsaturated n-3 fatty acids are formed as a result of the heat treatment of vegetable oils. It was demonstrated previously that the 18:3 delta 9cis, 12 cis, 15 trans containing a cis delta 9 ethylenic bond was converted to a geometrical isomer of 20:5n-3, the 20:5 delta 5 cis, ...
|
||
|
Cahoon E B - - 1996
Expression of a plant delta 6-palmitoyl (16:0)-acyl carrier protein desaturase in Escherichia coli resulted in the accumulation of the novel monounsaturated fatty acids delta 6-hexadecenoic acid (16:1 delta 6) and delta 8-octadecenoic acid. Amounts of 16:1 delta 6 accumulated by E. coli were increased more than twofold by the expression ...
|
||
|
Kawashima H - - 1996
Alkyl gallate, which is known as an antioxidant, intensively inhibited delta 5 and delta 6 desaturation in both rat liver microsomes and an arachidonic acid-producing fungus Mortierella alpina 1S-4. The rat liver microsomal delta 5 and delta 6 desaturases were inhibited by gallic acid esterified with alcohols with various numbers ...
|
||
|
Ivanetich K M - - 1996
A new method of assay for the delta 6-desaturation of linoleic acid was developed. This method, which uses HPLC for separation of the fatty acid substrate and product, exhibited a lower coefficient of variation (0.3%) than the reported TLC method (3.5%), and avoided the step of methylation of the saponified ...
|
||
|
Yang J Z - - 1996
OBJECTIVE: Our purpose was to evaluate and compare the conversion of 5-aminolevulinic acid into the endogenous photosensitizer protoporphyrin IX in experimentally induced endometriosis and in other normal tissues in a rat model. STUDY DESIGN: Fluorescence of experimental endometriotic lesions, uterus, peritoneum, bowel mesentery, bladder, eye, skin, and skeletal muscle was ...
|
||
|
Kriegmair M - - 1996
PURPOSE: We determined whether the sensitivity of detecting dysplasia or early bladder cancer can be improved by 5-aminolevulinic acid induced porphyrin fluorescence. MATERIALS AND METHODS: A 3% 5-aminolevulinic acid solution was instilled intravesically before cystoscopy in 104 patients. The 5-aminolevulinic acid induced porphyrin fluorescence was excited by violet light from ...
|
||
|
Gannon M J - - 1995
Photosensitization of the endometrium was attempted in vitro and in vivo by intrauterine administration of 5-aminolevulinic acid, which is converted to the photosensitizer protoporphyrin IX. Protoporphyrin IX was found in both functional and basal layers of the endometrial glands at concentrations nine and 10 times higher than myometrium in in ...
|
||
|
Peng Q - - 1995
Microscopic fluorescence photometry incorporating a light-sensitive thermo-electrically cooled charge-coupled device (CCD) camera was employed to investigate the fluorescence distribution of 5-aminolevulinic acid (ALA)-induced porphyrins in 22 patients with a total number of 52 noduloulcerative basal cell carcinomas (BCC) after topical ALA application with or without dimethylsulfoxide (DMSO)/ethylenediaminetetraacetic acid (EDTA) or ...
|
||
|
Szeimies R M - - 1995
A promising new therapeutic modality for skin cancer, administration of the heme precursor 5-aminolevulinic acid followed by light irradiation, is known as photodynamic therapy. Photofrin, the only clinically approved sensitizer, has an absorption maximum at 630 nm, the wavelength used in most experimental and clinical trials with 5-aminolevulinic acid. We ...
|
||
|
Identification of a new 6-bromo-5,9-eicosadienoic acid from the anemone Condylactis gigantea and ...
Carballeira N M - - 1995
A new brominated fatty acid, 6-bromo-5,9-eicosadienoic acid [1] was identified in the phospholipids (mainly phosphatidylethanolamine) of the anemone Condylactis gigantea and the zoanthid Palythoa caribaeorum. The delta 5,9 fatty acids, 5,9-octadecadienoic acid, 5,9-eicosadienoic acid, 5,9-docosadienoic acid, and 5,9-tetracosadienoic acid, were also identified in both organisms. Structural elucidation was accomplished by ...
|
||
|
Lee C Z - - 1995
Hepatitis delta virus (HDV) encodes two proteins, the small delta antigen (SHDAg) and large delta antigen (LHDAg). The latter is identical to the former except for the presence of additional 19 amino acids at the C terminus. While SHDAg is required for HDV replication, LHDAg inhibits replication and, together with ...
|
||
|
Takahashi Y - - 1995
The alteration of main disaccharide units in the skin of hairless mice (HOS:Hr 1) after chronic and repeated ultraviolet light (UV) radiation was investigated using high performance liquid chromatography after labeling with 1-phenyl-3-methyl-5-pyrazolone. The total amount of main disaccharide units increased by UVA irradiation at the 24th and 36th weeks ...
|
||
|
Basiuk V A - - 1995
To describe quantitatively the adsorption of prebiotically important compounds of low molecular weight (amino acids, short linear peptides, cyclic dipeptides, the Krebs's cycle and other carboxylic acids, nucleosides and related phosphates) on silica surface from diluted neutral aqueous solutions, equilibrium constants (K) and free energies (-delta G) of adsorption were ...
|
||
|
Ikegawa S - - 1995
From a stereochemical point of view, the dehydrogenation mechanism of the biotransformation of 3 alpha,7 alpha,12 alpha-trihydroxy-5 beta-cholestanoic acid (THCA) into (24E)-3 alpha,7 alpha,12 alpha-trihydroxy-5 beta-cholest-24-enoic acid (delta 24-THCA) has been studied with capillary gas chromatography (GC)/negative ion chemical ionization (NICI)-mass spectrometry. After incubation of (24R,25R)- or (24S,25S)-[24,25-2H2]THCA, synthesized from ...
|
||
|
Zelenaya-Troitskaya O - - 1995
The yeast mitochondrial high mobility group protein Abf2p is required, under certain growth conditions, for the maintenance of wild-type (rho+) mitochondrial DNA (mtDNA). We have identified a multicopy suppressor of the mtDNA instability phenotype of cells with a null allele of the ABF2 gene (delta abf2). The suppressor is a ...
|
||
|
Serve M P - - 1995
The urinary metabolites of n-nonane in male Fischer 344 rats, after administering the hydrocarbon by gavage, included gamma-valerolactone, delta-hexanolactone, 2,5-hexanedione, delta-heptanolactone, 1-heptanol, 2-nonanol, 3-nonanol, 4-nonanol, 4-nonanone and 5-methyl-2-(3-oxobutyl)furan. Metabolism strongly favored the formation of monoalcohols and lactones, which are the products of appropriately substituted hydroxy carboxylic acids. The metabolites were ...
|
||
|
Szirmai M - - 1995
The first synthesis of unlabelled and [2H5]-labelled 4",5"-bisnor-delta 1-THC-7,3"-dioic acid, the major dicarboxylated urinary metabolite of delta 1-THC in man, is presented (preliminary results of this work have been presented in part at the Melbourne Symposium on Cannabis, Australia, September 1987, Ref. 1). The synthesis of methyl 3-(3,5-dihydroxyphenyl)-[3,3-2H2]-propanoate (8) is ...
|
||
|
Tamura A - - 1995
Amino acid replacements of Met73, which is hyper-exposed in the native structure, with Asp, Glu, Lys, Gly, Ala, Val, Leu or Ile changed the stability of Streptomyces subtilism inhibitor by +1.60 to -0.94 kcal/mol-1 in free energy at 82.21 degrees C at pH 7.0, with higher hydrophobicity of the replacing ...
|
||
|
Zou J. - - 1995
Microspore-derived (MD) embryos of Brassica napus L. cv Reston were used to test the effects of (+)-abscisic acid ([(+)-ABA]) and its metabolites, 8[prime]-hydroxyabscisic acid (8[prime]-OH ABA) and (-)-phaseic acid (PA), on the accumulation of very long-chain monounsaturated fatty acids (VLCMFAs) and induction of genes encoding a 19-kD oleosin protein and ...
|
||
|
Malik Z - - 1995
Topical 5-aminolevulinic acid (ALA) application in three different creams was carried out on mice bearing subcutaneously transplanted C26 colon carcinoma. The creams contained (a) 20% ALA alone, (b) ALA with 2% dimethylsulphoxide (DMSO) and (c) ALA, DMSO and 2% edetic acid disodium salt (EDTA). Protoporphyrin IX (PP) production in the ...
|
||
|
Antifreeze glycopeptides of the high-Antarctic silverfish Pleuragramma antarcticum (Notothenioidei).
Wöhrmann A P - - 1995
Antifreeze glycopeptides (AFGP) have been isolated from the fully pelagic high-Antarctic silverfish Pleuragramma antarcticum of the suborder Notothenioidei (Perciformes). The fishes were caught during the PRV Polarstern expedition EPOS III (Jan-Mar, 1989) in the eastern and southeastern Weddell Sea. Glycoconjugate and amino acid analysis of antifreeze glycopeptides (AFGP) indicate that ...
|
||
|
Yu S - - 1995
In the present study we used regression analyses to evaluate the effects of stearic acid (18:0) on total cholesterol (TC), low-density-lipoprotein-cholesterol (LDL-C), and high-density-lipoprotein-cholesterol (HDL-C) concentrations (mmol/L). Using data from 18 articles, we developed the following predictive equations (monounsaturated fatty acids, MUFAs; polyunsaturated fatty acids, PUFAs): delta TC = 0.0522 ...
|
||
|
Limberg G - - 1995
Aldonic acids containing four to six carbon atoms were tested as potential substrates of dihydroxy acid dehydratase (DHAD), an enzyme from the biosynthetic pathway of branched chain amino acids. Novel assay systems for observing the course of DHAD catalysed reactions were developed in order to adapt the enzyme to extended ...
|
||
|
Leikin A - - 1995
The delta 6-desaturase system was isolated from rat liver microsomes by high hydrostatic pressure (1500 bars) and the enzyme components were then separated by size chromatography. The lipids extracted by organic solvents from the pressure shed fractions were phosphatidylcholine (PC) and cholesterol at a mole ratio of 4:1. The acyl ...
|
||
|
delta 22-Ursodeoxycholic acid, a unique metabolite of administered ursodeoxycholic acid in rats, ...
Setchell K D - - 1995
We describe for the first time the identification of 3 alpha, 7 beta-dihydroxy-5 beta-chol-22-en-24-oic acid (delta 22-UDCA) in the plasma, bile, intestinal contents, and liver tissue of Sprague-Dawley rats after intravenous and oral administration of ursodeoxycholic acid (UDCA). Infusion of [2,2,4,4-2H4]UDCA confirmed delta 22-UDCA to be a specific metabolite of ...
|
||
|
Chai W - - 1995
The characterisation of oligosaccharide fragments isolated from enzymatically depolymerised porcine intestinal heparin is required in order to probe structure/function relationships of heparin in anticoagulation, antiangiogenesis and antiviral activity. We have used both LSI-MS and 600-MHz 1H NMR with chemical shift assignment by comprehensive 1H-1H TOCSY experiments to fully characterise the ...
|
||
|
Dias V C - - 1995
We report the influence of media lipids, growth in lipid-poor medium, and cell differentiation on delta 9, delta 6, and delta 5 desaturase activity in the human CaCo-2 enterocyte cell line. We also describe the level of incorporation of palmitic (16:0), linoleic (18:2n-6), and eicosapentaenoic (EPA) acids (20:5n-3) and their ...
|
||
|
Engel M H - - 1995
A combined gas chromatography/isotope ratio mass spectrometry (GC/IRMS) method has been developed that permits the direct stable carbon isotope analysis of N(O)-trifluoroacetyl-isopropyl esters of individual amino acids and their respective enantiomers at nanomole abundances. Calculation of the original delta 13C values of the amino acids is accomplished via a correction ...
|
||
|
Plewka A - - 1995
delta-Aminolevulinic acid synthase is a key enzyme leading to the synthesis of cytochrome P-450, a compound of the mixed function oxidase system. Because of this, we have studied the effects of both age and three typical mixed function oxidase system induces on this enzyme activity in male Wistar rats. Our ...
|
||
|
Jahnke L L - - 1995
A lipid analysis of the tissues of a cold-seep mytilid mussel collected from the Louisiana slope of the Gulf of Mexico was used in conjunction with a compound-specific isotope analysis to demonstrate the presence of methanotrophic symbionts in the mussel gill tissue and to demonstrate the host's dependence on bacterially ...
|
||
|
Goto M - - 1995
Several surfactant-coated enzymes have been prepared by coating lipases of various origins with a nonionic surfactant, glutamic acid dioleylester ribitol (2C(18)Delta(9)GE). Enzymatic interesterification of tripalmitin with oleic acid using the surfactant-coated lipase was carried out in organic media. The surfactant-coated lipases could effectively catalyze the interesterification of glycerides better than ...
|
||
|
Masaki H - - 1995
Previously we demonstrated that hamamelitannin (2',5-di-O-galloyl hamamelose) in Hamamelis virginiana L. exhibits potent superoxide-anion scavenging activity. We then examined the physiological and pharmacological activities of hamamelitannin as well as its functional homologues, gallic acid and syringic acid. The following results were obtained: (1) Hamamelitannin has a higher protective activity against ...
|
||
|
Vázquez-Prado J - - 1995
A spectrophotometric method for porphobilinogen deaminase assay in erythrocytes is described. This test is determinant for the definite diagnosis of acute intermittent porphyria. In the method described, delta-aminolevulinic acid is used as substrate. Mercaptoethanol and zinc ions are introduced to maintain delta-aminolevulinic acid dehydratase in optimal conditions and to guarantee ...
|
||
|
Lajis N H - - 1995
The hydroxide ion-catalyzed hydrolysis of securinine involves the ring opening of the lactone moiety. The rate of hydrolysis is insensitive to the ionic strength. The observed pseudo-first-order rate constants reveal a decrease of approximately 4-fold due to the increase in the MeCN content from 4 to 50% (v/v) in mixed ...
|
||
|
Chalevelakis G - - 1995
delta-Aminolaevulinic acid dehydratase activity is traditionally accepted as the most sensitive measurable biological index of lead toxicity. We have measured delta-aminolaevulinic acid dehydratase activity and blood lead concentration in 47 healthy controls (A), 42 iron deficient patients (B) and 38 occupationally exposed to lead subjects (C). Blood lead levels [mean ...
|
||
|
Carballeira N M - - 1994
The diunsaturated fatty acids 5,9-heneicosadienoic acid, 5,9-docosadienoic acid and 5,9-tricosadienoic acid, the brominated fatty acids 6-bromo- 5,9-heneicosadienoic acid and 6-bromo-5,9-docosadienoic acid, and the polyunsaturated fatty acids 5,9,13-eicosatrienoic acid and 5,9,13-docosatrienoic acid, were identified for the first time in nature in the phospholipids (mainly phosphatidylethanolamine and phosphatidylserine) of the anemone Stoichactis ...
|
||
|
Pizzarello S - - 1994
The combined volatile bases (ammonia, aliphatic amines, and possibly other bases), ammonia, amino acids, and polar hydrocarbons were prepared from the Murchison meteorite for isotopic analyses. The volatile bases were obtained by cryogenic transfer after acid-hydrolysis of a hot-water extract and analyzed by combined gas chromatography-mass spectrometry of pentafluoropropionyl derivatives. ...
|
||
|
Cahoon E B - - 1994
delta 6 Hexadecenoic acid (16:1 delta 6) composes more than 80% of the seed oil of Thunbergia alata. Studies were conducted to determine the biosynthetic origin of the double bond of this unusual fatty acid. Assays of fractions of developing T. alata seed endosperm with [1-14C]palmitoyl (16:0)-acyl carrier protein (ACP) ...
|
||
|
Wyss P - - 1994
OBJECTIVE: The goal of this study was to determine the optimal parameters for photodynamic endometrial destruction with topically applied 5-aminolevulinic acid, a precursor for the endogenous synthesis of the fluorescent photosensitizer protoporphyrin IX. STUDY DESIGN: 5-Aminolevulinic acid pharmacokinetics were measured in rat and rabbit models by analyzing tissue frozen sections ...
|
||
|
Steinbach P - - 1994
OBJECTIVES: For photodynamic therapy 5-aminolevulinic acid is an attractive compound, since it is a physiologic endogenous substance, and its application in excess results in the accumulation of the metabolite protoporphyrin IX, a very effective photosensitizer. The topical application of 5-aminolevulinic acid in the urinary bladder led to pronounced fluorescence in ...
|
||
|
Rotoli B M - - 1994
Trans-membrane fluxes of leucine were measured in mouse C127i cells transfected with the wild type (C127 CFTRw/t) or the delta F508 CF gene (C127 CFTR delta F508). Leucine efflux was significantly faster in C127 CFTRw/t cells. On the contrary, leucine influx was comparable in the two cell lines and referable ...
|
||
|
Engel M H - - 1994
Comparison of the delta 13C values of D and L enantiomers of individual amino acids was used to evaluate the presence of amino acid contaminants in Quaternary land snails. Measurements of delta 13C values of amino acid D and L enantiomers determined by combined gas chromatography, combustion, isotope-ratio mass spectrometry ...
|
||
|
LaLonde J M - - 1994
The association of the adipocyte lipid-binding protein (ALBP) with arachidonic acid (all cis, 20:4 delta 5,8,11,14) and oleic acid (cis, 18:1 delta 9) has been examined by titration calorimentry. In addition, the crystal structure of ALBP with bound arachidonic acid has also been obtained. Crystallographic analysis of the arachidonic acid.ALBP ...
|
||
|
Sakamoto T - - 1994
In cyanobacteria, the biosynthesis of unsaturated fatty acids is initiated by delta 9 acyl-lipid desaturase which introduces the first double bond at the delta 9 position of a saturated fatty acid that has been esterified to a glycerolipid. We have cloned genes, designated desC, for delta 9 acyl-lipid desaturases from ...
|
||
|
Borland A. M. - - 1994
Carbon-isotope ratios ([delta]13Cs) were measured for various bio-chemical fractions quantitatively extracted from naturally exposed and shaded leaves of the C3-Crassulacean acid metabolism (CAM) intermediate Clusia minor, sampled at dawn and dusk on days during the wet and dry seasons in Trinidad. As the activity of CAM increased in response to ...
|
||
| < 5 6 7 8 9 10 11 12 13 14 15 > | ||