id stringlengths 15 19 | title stringlengths 4 400 | content stringlengths 65 5.3k | contents stringlengths 139 5.45k | PMID int64 42 1.3M |
|---|---|---|---|---|
pubmed23n0001_17 | A competitive labeling method for the determination of the chemical properties of solitary functional groups in proteins. | The properties of the functional groups in a protein can be used as built-in-probes of the structure of the protein. We have developed a general procedure whereby the ionization constant and chemical reactivity of solitary functional groups in proteins may be determined. The method may be applied to the side chain of h... | A competitive labeling method for the determination of the chemical properties of solitary functional groups in proteins. The properties of the functional groups in a protein can be used as built-in-probes of the structure of the protein. We have developed a general procedure whereby the ionization constant and chemica... | 42 |
pubmed23n0001_20 | Bovine liver dihydrofolate reductase: purification and properties of the enzyme. | A purification procedure is reported for obtaining bovine liver dihydrofolate reductase in high yield and amounts of 100-200 mg. A key step in the procedure is the use of an affinity gel prepared by coupling pteroyl-L-lysine to Sepharose. The purified reductase has a specific activity of about 100 units/mg and is homog... | Bovine liver dihydrofolate reductase: purification and properties of the enzyme. A purification procedure is reported for obtaining bovine liver dihydrofolate reductase in high yield and amounts of 100-200 mg. A key step in the procedure is the use of an affinity gel prepared by coupling pteroyl-L-lysine to Sepharose. ... | 45 |
pubmed23n0001_21 | Purification and properties of Escherichia coli dihydrofolate reductase. | Dihydrofolate reductase has been purified 40-fold to apparent homogeneity from a trimethoprim-resistant strain of Escherichia coli (RT 500) using a procedure that includes methotrexate affinity column chromatography. Determinations of the molecular weight of the enzyme based on its amino acid composition, sedimentation... | Purification and properties of Escherichia coli dihydrofolate reductase. Dihydrofolate reductase has been purified 40-fold to apparent homogeneity from a trimethoprim-resistant strain of Escherichia coli (RT 500) using a procedure that includes methotrexate affinity column chromatography. Determinations of the molecula... | 46 |
pubmed23n0001_22 | The influence of pH on the interaction of inhibitors with triosephosphate isomerase and determination of the pKa of the active-site carboxyl group. | Ionization effects on the binding of the potential transition state analogues 2-phosphoglycolate and 2-phosphoglycolohydroxamate appear to be attributable to the changing state of ionization of the ligands themselves, therefore it is unnecessary to postulate the additional involvement of an ionizing residue at the acti... | The influence of pH on the interaction of inhibitors with triosephosphate isomerase and determination of the pKa of the active-site carboxyl group. Ionization effects on the binding of the potential transition state analogues 2-phosphoglycolate and 2-phosphoglycolohydroxamate appear to be attributable to the changing s... | 47 |
pubmed23n0001_25 | Circular dichroism and fluorescence studies of homogeneous antibodies to type III pneumococcal polysaccharide. | The near-ultraviolet circular dichroism (CD) of three homogeneous anti-type III pneumococcal antibodies in the absence and the presence of the specific hexasaccharide ligand was studied. In addition recombinations and hybridizations of H and L chains derived from two of these antibodies were carried out and the CD spec... | Circular dichroism and fluorescence studies of homogeneous antibodies to type III pneumococcal polysaccharide. The near-ultraviolet circular dichroism (CD) of three homogeneous anti-type III pneumococcal antibodies in the absence and the presence of the specific hexasaccharide ligand was studied. In addition recombinat... | 50 |
pubmed23n0001_26 | Conformational changes induced in a homogeneous anti-type III pneumococcal antibody by oligosaccharides of increasing size. | The circular polarization of luminescence (CPL) emitted by tryptophan residues was used as a sensitive probe for measuring ligand-induced structural changes in a homogeneous type III pneumococcal antibody. A series of oligosaccharide ligands of increasing size derived from type III polysaccharide by partial acid hydrol... | Conformational changes induced in a homogeneous anti-type III pneumococcal antibody by oligosaccharides of increasing size. The circular polarization of luminescence (CPL) emitted by tryptophan residues was used as a sensitive probe for measuring ligand-induced structural changes in a homogeneous type III pneumococcal ... | 51 |
pubmed23n0001_28 | The interaction of phospholipase A2 with micellar interfaces. The role of the N-terminal region. | The localization of the previously postulated interface recognition site (IRS) in porcine pancreatic phospholipase A2, required for a specific interaction between the enzyme and organized lipid-water interfaces, was investigated by ultraviolet difference spectroscopy, by measurements of the intrinsic fluorescence of th... | The interaction of phospholipase A2 with micellar interfaces. The role of the N-terminal region. The localization of the previously postulated interface recognition site (IRS) in porcine pancreatic phospholipase A2, required for a specific interaction between the enzyme and organized lipid-water interfaces, was investi... | 53 |
pubmed23n0001_29 | Phospholipase A2 as a probe of phospholipid distribution in erythrocyte membranes. Factors influencing the apparent specificity of the reaction. | The action of snake venom phospholipases A2 in intact human erythrocytes was investigated in detail. The basis phospholipase from Agkistrodon halys blomhifii was found to induce both hydrolysis of membrane phospholipids and total cell hemolysis under certain experimental conditions. The hydrolytic action of the basic e... | Phospholipase A2 as a probe of phospholipid distribution in erythrocyte membranes. Factors influencing the apparent specificity of the reaction. The action of snake venom phospholipases A2 in intact human erythrocytes was investigated in detail. The basis phospholipase from Agkistrodon halys blomhifii was found to indu... | 54 |
pubmed23n0001_30 | Subunit interactions in yeast glyceraldehyde-3-phosphate dehydrogenase. | The spontaneous inactivation of yeast glyceraldehyde-3-phosphate dehydrogenase was found to fit a simple two-state model at pH 8.5 and 25 degrees. The first step is a relatively rapid dissociation of the tetramer to dimers with the equilibrium largely in favor of the tetramer. In the absence of NAD+ the dimer inactivat... | Subunit interactions in yeast glyceraldehyde-3-phosphate dehydrogenase. The spontaneous inactivation of yeast glyceraldehyde-3-phosphate dehydrogenase was found to fit a simple two-state model at pH 8.5 and 25 degrees. The first step is a relatively rapid dissociation of the tetramer to dimers with the equilibrium larg... | 55 |
pubmed23n0001_31 | Kinetic light scattering studies on the dissociation of hemoglobin from Lumbricus terrestris. | The kinetics of the pH-induced dissociation of the 3 X 10(6) mol wt hemoglobin from Lumbricus terrestris (the earthworm) have been studied in a light-scattering stopped-flow apparatus. The ligand dependent dissociation data were fit well by a simple sequential model. The data for CO and oxyhemoglobin are consistent wit... | Kinetic light scattering studies on the dissociation of hemoglobin from Lumbricus terrestris. The kinetics of the pH-induced dissociation of the 3 X 10(6) mol wt hemoglobin from Lumbricus terrestris (the earthworm) have been studied in a light-scattering stopped-flow apparatus. The ligand dependent dissociation data we... | 56 |
pubmed23n0001_38 | Enzymic reactions of fatty acid hydroperoxides in extracts of potato tuber. II. Conversion of 9- and 13-hydroperoxy-octadecadienoic acids to monohydroxydienoic acid, epoxyhydroxy- and trihydroxymonoenoic acid derivatives. | 1. Crude extracts and partially purified enzyme preparations from potato tubers catalyse, at pH 5-7, the conversion of linoleic acid hydroperoxides to a range of oxygenated fatty acid derivatives. 2. 9-D- and 13-L-hydroperoxide isomers are converted at similar rates to equivalent (isomeric) products. 3. The major produ... | Enzymic reactions of fatty acid hydroperoxides in extracts of potato tuber. II. Conversion of 9- and 13-hydroperoxy-octadecadienoic acids to monohydroxydienoic acid, epoxyhydroxy- and trihydroxymonoenoic acid derivatives. 1. Crude extracts and partially purified enzyme preparations from potato tubers catalyse, at pH 5-... | 63 |
pubmed23n0001_39 | Partial purification and properties of microsomal phosphatidate phosphohydrolase from rat liver. | Microsomal phosphatidate phosphohydrolase (phosphatidate phosphatase EC 3.1.3.4) was solubilized and fractionated to yield at least two distinct enzymatically active fractions. One, denoted FA, was non-specific, had a relatively high Km for phosphatidic acid and was insensitive to inhibition by diacylglycerol. The seco... | Partial purification and properties of microsomal phosphatidate phosphohydrolase from rat liver. Microsomal phosphatidate phosphohydrolase (phosphatidate phosphatase EC 3.1.3.4) was solubilized and fractionated to yield at least two distinct enzymatically active fractions. One, denoted FA, was non-specific, had a relat... | 64 |
pubmed23n0001_42 | Cholinesterases from plant tissues. VI. Preliminary characterization of enzymes from Solanum melongena L. and Zea mays L. | Enzymes capable of hydrolyzing esters of thiocholine have been assayed in extracts of Solanum melongena L. (eggplant) and Zea Mays L. (corn). The enzymes from both species are inhibited by the anti-cholinesterases neostigmine, physostigmine, and 284c51 and by AMO-1618, a plant growth retardant and they both have pH opt... | Cholinesterases from plant tissues. VI. Preliminary characterization of enzymes from Solanum melongena L. and Zea mays L. Enzymes capable of hydrolyzing esters of thiocholine have been assayed in extracts of Solanum melongena L. (eggplant) and Zea Mays L. (corn). The enzymes from both species are inhibited by the anti-... | 67 |
pubmed23n0001_45 | Specificity studies on alpha-mannosidases using oligosaccharides from mannosidosis urine as substrates. | Oligosaccharides containing terminal non-reducing alpha(1 leads to 2)-, alpha(1 leads to 3)-, and alpha(1 leads to 6)-linked mannose residues, isolated from human and bovine mannosidosis urines were used as substrates to test the specificities of acidic alpha-mannosidases isolated from human and bovine liver. The enzym... | Specificity studies on alpha-mannosidases using oligosaccharides from mannosidosis urine as substrates. Oligosaccharides containing terminal non-reducing alpha(1 leads to 2)-, alpha(1 leads to 3)-, and alpha(1 leads to 6)-linked mannose residues, isolated from human and bovine mannosidosis urines were used as substrate... | 70 |
pubmed23n0001_47 | Preparation and characterization of an enzymatically active immobilized derivative of myosin. | Purified skeletal muscle myosin (EC 3.6.1.3) has been covalently bound to Sepharose 4B by the cyanogen bromide procedure. The resulting complex, Sepharose-Myosin, possesses adenosine triphosphatase activity and is relatively stable for long periods of time. Under optimal binding conditions, approximately 33% of the spe... | Preparation and characterization of an enzymatically active immobilized derivative of myosin. Purified skeletal muscle myosin (EC 3.6.1.3) has been covalently bound to Sepharose 4B by the cyanogen bromide procedure. The resulting complex, Sepharose-Myosin, possesses adenosine triphosphatase activity and is relatively s... | 72 |
pubmed23n0001_48 | Radioactive labeling and location of specific thiol groups in myosin from fast, slow and cardiac muscles. | 1. Based on incorporation of radioactively labeled N-ethylmaleimide, the readily reactive thiol groups of isolated myosin (EC 3.6.1.3) from fast, slow and cardiac muscles could be classified into 3 types. All 3 myosins contain 2 thiol-1, 2 thiol-2 and a variable number of thiol-3 groups per molecule. Both thiol-1 and t... | Radioactive labeling and location of specific thiol groups in myosin from fast, slow and cardiac muscles. 1. Based on incorporation of radioactively labeled N-ethylmaleimide, the readily reactive thiol groups of isolated myosin (EC 3.6.1.3) from fast, slow and cardiac muscles could be classified into 3 types. All 3 myo... | 73 |
pubmed23n0001_56 | N-terminal spin label studies of hemoglobin, Ligand and pH dependence. | Human hemoglobin was spin labeled with 4-isothiocanato-2,2,6,6-tetramethyl-piperdinooxyl, which is known to bind specifically to the N-terminal alpha-amino groups of proteins and slightly to the reactive sulfhydryl groups. Electron spin resonance (ESR) analysis indicated a partially resolved five-line spectrum, suggest... | N-terminal spin label studies of hemoglobin, Ligand and pH dependence. Human hemoglobin was spin labeled with 4-isothiocanato-2,2,6,6-tetramethyl-piperdinooxyl, which is known to bind specifically to the N-terminal alpha-amino groups of proteins and slightly to the reactive sulfhydryl groups. Electron spin resonance (E... | 81 |
pubmed23n0001_65 | Alterations in phospholipid-dependent (Na+ +K+)-ATPase activity due to lipid fluidity. Effects of cholesterol and Mg2+. | The (Na+ +K+)-activated, Mg2+-dependent ATPase from rabbit kidney outer medulla was prepared in a partially inactivated, soluble form depleted of endogenous phospholipids, using deoxycholate. This preparation was reactivated 10 to 50-fold by sonicated liposomes of phosphatidylserine, but not by non-sonicated phosphatid... | Alterations in phospholipid-dependent (Na+ +K+)-ATPase activity due to lipid fluidity. Effects of cholesterol and Mg2+. The (Na+ +K+)-activated, Mg2+-dependent ATPase from rabbit kidney outer medulla was prepared in a partially inactivated, soluble form depleted of endogenous phospholipids, using deoxycholate. This pre... | 90 |
pubmed23n0001_80 | Inhibitory postsynaptic actions of taurine, GABA and other amino acids on motoneurons of the isolated frog spinal cord. | The actions of glycine, GABA, alpha-alanine, beta-alanine and taurine were studied by intracellular recordings from lumbar motoneurons of the isolated spinal cord of the frog. All amino acids tested produced a reduction in the amplitude of postsynaptic potentials, a blockade of the antidromic action potential and an in... | Inhibitory postsynaptic actions of taurine, GABA and other amino acids on motoneurons of the isolated frog spinal cord. The actions of glycine, GABA, alpha-alanine, beta-alanine and taurine were studied by intracellular recordings from lumbar motoneurons of the isolated spinal cord of the frog. All amino acids tested p... | 128 |
pubmed23n0001_81 | The involvement of lysophosphoglycerides in neurotransmitter release; the composition and turnover of phospholipids of synaptic vesicles of guinea-pig cerebral cortex and Torpedo electric organ and the effect of stimulation. | (1) Crude synaptosomal fractions (P2) derived from guinea-pig cerebral cortex were incubated in the presence of 50 mM KCl in a Krebs-glucose medium. Torpedo marmorata electric organs were stimulated electrically in vivo at 5 pulses/sec for 30 min by electrodes placed on the electric lobe. Synaptic vesicles were isolate... | The involvement of lysophosphoglycerides in neurotransmitter release; the composition and turnover of phospholipids of synaptic vesicles of guinea-pig cerebral cortex and Torpedo electric organ and the effect of stimulation. (1) Crude synaptosomal fractions (P2) derived from guinea-pig cerebral cortex were incubated in... | 129 |
pubmed23n0001_86 | Nitrofurazone-reducing enzymes in E. coli and their role in drug activation in vivo. | Earlier work showed that Escherichia coli contains at least two enzymes which reduce nitrofurazone and other nitrofuran derivatives. One of these enzymes is lacking in some nitrofurazone-resistant mutant strains. We now report that there are three separable nitrofuran reductases in this organism: reductase I (mol. wt. ... | Nitrofurazone-reducing enzymes in E. coli and their role in drug activation in vivo. Earlier work showed that Escherichia coli contains at least two enzymes which reduce nitrofurazone and other nitrofuran derivatives. One of these enzymes is lacking in some nitrofurazone-resistant mutant strains. We now report that the... | 136 |
pubmed23n0001_87 | Enzymatic hydrolysis of agar: purification and characterization of neoagarobiose hydrolase and p-nitrophenyl alpha-galactoside hydrolase. | The mixture of polysaccharides in the gelling component of agar (agarose) is hydrolyzed to D-galactose and 3,6-anhydro-L-galactose by a series of hydrolytic enzymes obtained from Pseudomonas atlantica. The final degradative step in the pathway of agarose decomposition is the hydrolysis of the alpha-linkage in the dissa... | Enzymatic hydrolysis of agar: purification and characterization of neoagarobiose hydrolase and p-nitrophenyl alpha-galactoside hydrolase. The mixture of polysaccharides in the gelling component of agar (agarose) is hydrolyzed to D-galactose and 3,6-anhydro-L-galactose by a series of hydrolytic enzymes obtained from Pse... | 137 |
pubmed23n0001_90 | Regulation and properties of an invertase from Clostridium pasteurianum. | An intracellular invertase was induced in cultures of Clostridium pasteurianum utilizing sucrose as its carbon source for growth. This enzyme synthesis could be repressed by the addition of fructose of a sucrose-growing culture. In contrast, invertase activity was not affected by the addition of glucose to sucrose-grow... | Regulation and properties of an invertase from Clostridium pasteurianum. An intracellular invertase was induced in cultures of Clostridium pasteurianum utilizing sucrose as its carbon source for growth. This enzyme synthesis could be repressed by the addition of fructose of a sucrose-growing culture. In contrast, inver... | 140 |
pubmed23n0001_91 | Characterization studies on the membrane-bound adenosine triphosphatase (ATPase) of Azotobacter vinelandii. | The adenosinetriphosphatase (ATPase) (EC 3.6.1.3) activity in Azotobacter vinelandii concentrates in the membranous R3 fraction that is directly associated with Azotobacter electron transport function. Sonically disrupted Azotobacter cells were examined for distribution of ATPase activity and the highest specific activ... | Characterization studies on the membrane-bound adenosine triphosphatase (ATPase) of Azotobacter vinelandii. The adenosinetriphosphatase (ATPase) (EC 3.6.1.3) activity in Azotobacter vinelandii concentrates in the membranous R3 fraction that is directly associated with Azotobacter electron transport function. Sonically ... | 141 |
pubmed23n0001_95 | Some characteristics of two azoreductase systems in rat liver. Relevance to the activity of 2-[4'-di(2"-bromopropyl)-aminophenylazo]benzoic acid (CB10-252), a compound possessing latent cytotoxic activity. | The system involved in the reduction of 2-[4'-di(2''-bromopropyl) aminophenylazolbenzoic acid (CB10-252), an agent designed for treating primary liver cell cancer, has been demonstrated to be localised mainly in the 108 000 X g supernatant fraction of rat liver homogenate. It is also present in other organs particularl... | Some characteristics of two azoreductase systems in rat liver. Relevance to the activity of 2-[4'-di(2"-bromopropyl)-aminophenylazo]benzoic acid (CB10-252), a compound possessing latent cytotoxic activity. The system involved in the reduction of 2-[4'-di(2''-bromopropyl) aminophenylazolbenzoic acid (CB10-252), an agent... | 149 |
pubmed23n0001_108 | Improved high-resolution high-voltage paper electrophoresis system for use in screening for aminoacidopathies. | High-voltage paper electrophoresis of small samples of serum and urine at pH 6.0 resolves basic and acidic amino acids and separates them from the neutral amino acids. For separation and identification of the neutral amino acids, the appropriate area of the electrophoretogram is cut out, sewn onto a second sheet of pap... | Improved high-resolution high-voltage paper electrophoresis system for use in screening for aminoacidopathies. High-voltage paper electrophoresis of small samples of serum and urine at pH 6.0 resolves basic and acidic amino acids and separates them from the neutral amino acids. For separation and identification of the ... | 162 |
pubmed23n0001_109 | A clinical method for the determination of serum gamma-glutamyl transpeptidase. | A simple, highly sensitive and reproducible method for the assay of gamma-glutamyl transpeptidase (EC 2.3.2-) activity is introduced, using gamma-glutamyl-p-nitroanilide as a substrate and glycylglycine as an acceptor in 50 g/l of polyoxyethylene nonylphenol. Serum transpeptidase activity was assayed in 1080 healthy ad... | A clinical method for the determination of serum gamma-glutamyl transpeptidase. A simple, highly sensitive and reproducible method for the assay of gamma-glutamyl transpeptidase (EC 2.3.2-) activity is introduced, using gamma-glutamyl-p-nitroanilide as a substrate and glycylglycine as an acceptor in 50 g/l of polyoxyet... | 165 |
pubmed23n0001_110 | Treatment of renal hypertension. | There are different types of renal hypertension: hypertension due to parenchymal renal disease, renovascular hypertension, hypertension due to urological disease, hypertension of endstage renal disease. Treatment has to consider-above all-the possibility of specific, medical or surgical procedures that may cause the un... | Treatment of renal hypertension. There are different types of renal hypertension: hypertension due to parenchymal renal disease, renovascular hypertension, hypertension due to urological disease, hypertension of endstage renal disease. Treatment has to consider-above all-the possibility of specific, medical or surgical... | 167 |
pubmed23n0001_114 | Influence of pH and hypoxia on the success of defibrillation. | Clinical impressions about the problem of defibrillation during states of acid-base imbalance and hypoxia have been influenced by studies involving the effect of these derangements on the ventricular fibrillation threshold. Based on body weight, energy requirements for defibrillation in normal dogs were compared to req... | Influence of pH and hypoxia on the success of defibrillation. Clinical impressions about the problem of defibrillation during states of acid-base imbalance and hypoxia have been influenced by studies involving the effect of these derangements on the ventricular fibrillation threshold. Based on body weight, energy requi... | 210 |
pubmed23n0001_127 | The internal-alkaline pH gradient, sensitive to uncoupler and ATPase inhibitor, in growing Clostridium pasteurianum. | 1. The intracellular pH was measured in growing Clostridium pasteurianum with and acid-base equilibrium distribution method. [14C]Dimethyloxazolidinedione, [14]methylamine and [14C]acetic acid were used as "deltapH-indicators". During growth the extracellular pH decreased from 7.1 to 5.1; simultaneously the intracellul... | The internal-alkaline pH gradient, sensitive to uncoupler and ATPase inhibitor, in growing Clostridium pasteurianum. 1. The intracellular pH was measured in growing Clostridium pasteurianum with and acid-base equilibrium distribution method. [14C]Dimethyloxazolidinedione, [14]methylamine and [14C]acetic acid were used ... | 237 |
pubmed23n0001_128 | D-alanyl-D-alanine carboxypeptidase in the bacterial form and L-form of Proteus mirabilis. | Membranes of the bacterial form and the stable and unstable L-forms of Proteus mirabilis contain LD and DD-carboxypeptidase. The DD-carboxypeptidase is inhibited non-competitively by penicillin G. The enzyme of the bacterial form is highly penicillin-sensitive (Ki - 4 X 10(-9) M penicillin G). Inhibition is only partly... | D-alanyl-D-alanine carboxypeptidase in the bacterial form and L-form of Proteus mirabilis. Membranes of the bacterial form and the stable and unstable L-forms of Proteus mirabilis contain LD and DD-carboxypeptidase. The DD-carboxypeptidase is inhibited non-competitively by penicillin G. The enzyme of the bacterial form... | 238 |
pubmed23n0001_132 | An evaluation of factors affecting the in vitro bioassay for erythropoietin. | Two main aspects of the in vitro mouse foetal liver cell assay for Erythroid Stimulating Factor (ESF) in human sera have been investigated. The haem extraction process has been shown to give specific and quantitative recovery of 59Fe labelled haem from haemoglobin thus confirming that the material assayed in human sera... | An evaluation of factors affecting the in vitro bioassay for erythropoietin. Two main aspects of the in vitro mouse foetal liver cell assay for Erythroid Stimulating Factor (ESF) in human sera have been investigated. The haem extraction process has been shown to give specific and quantitative recovery of 59Fe labelled ... | 250 |
pubmed23n0001_136 | Recombination as a requirement for segregation of a partially diploid mutant of Pneumococcus. | Conditions are described in which the pneumococcal mutant strain sulr-c, resistant to the drug sulfanilamide, gives rise to sensitive segregants resistant to nitrobenzoic acid at a frequency constant with time. This segregant frequency is markedly enhanced upon exposure of the cells to doses of ultraviolet light or mit... | Recombination as a requirement for segregation of a partially diploid mutant of Pneumococcus. Conditions are described in which the pneumococcal mutant strain sulr-c, resistant to the drug sulfanilamide, gives rise to sensitive segregants resistant to nitrobenzoic acid at a frequency constant with time. This segregant ... | 271 |
pubmed23n0001_145 | Prevention of cell agglutination and competence in a genetically transformable strain of Pneumococcus by D-glucosamine and D-galactosamine. | In the presence of amino sugars D-glucosamine and D-galactosamine no spontaneous competence could be observed in the highly transformable R6bd strain of Pneumococcus or it was decreased by several orders of magnitude. The highest inhibition of competence was detected when the amino sugar at a concentration 5 mg/ml of t... | Prevention of cell agglutination and competence in a genetically transformable strain of Pneumococcus by D-glucosamine and D-galactosamine. In the presence of amino sugars D-glucosamine and D-galactosamine no spontaneous competence could be observed in the highly transformable R6bd strain of Pneumococcus or it was decr... | 284 |
pubmed23n0001_147 | Transport properties of membrane vesicles from Acholeplasma laidlawii. II. Kinetic characteristics and specificity of glucose transport system. | The glucose transport system of membrane vesicles isolated from Acholeplasma laidlawii is saturable, with a Km of 21.2 mum and V of 0.68 nmol min-1 (mg protein)-1. The process is pH-dependent and a break occurs in the Arrhenius plot at 15 degrees C. Exogenous substrates did not stimulate glucose transport probably due ... | Transport properties of membrane vesicles from Acholeplasma laidlawii. II. Kinetic characteristics and specificity of glucose transport system. The glucose transport system of membrane vesicles isolated from Acholeplasma laidlawii is saturable, with a Km of 21.2 mum and V of 0.68 nmol min-1 (mg protein)-1. The process ... | 286 |
pubmed23n0001_148 | Transport of 4-deoxy- and 6-deoxy-D-glucose in baker's yeast. | Tritium-labelled 4-deoxy-D-glucose (4-dglc) and 6-deoxy-D-glucose (6-dgcl) were prepared by catalytic hydrogenolysis of the corresponding deoxyiodo derivatives with gaseous tritium. The two sugars are transported into Saccharomyces cerevisiae by both the constitutive glucose and the inducible galactose carrier. Uranyl ... | Transport of 4-deoxy- and 6-deoxy-D-glucose in baker's yeast. Tritium-labelled 4-deoxy-D-glucose (4-dglc) and 6-deoxy-D-glucose (6-dgcl) were prepared by catalytic hydrogenolysis of the corresponding deoxyiodo derivatives with gaseous tritium. The two sugars are transported into Saccharomyces cerevisiae by both the con... | 287 |
pubmed23n0001_156 | Using a hospital for desensitization of an outpatient's illness-related fears. | An outpatient with phobias related to enclosed places, hospitals, doctors, and cancer was treated by systematic desensitization; the facilities of a general hospital were used for part of the process. Steps in treatment included securing a complete psychiatric and social history, teaching the patient relaxation therapy... | Using a hospital for desensitization of an outpatient's illness-related fears. An outpatient with phobias related to enclosed places, hospitals, doctors, and cancer was treated by systematic desensitization; the facilities of a general hospital were used for part of the process. Steps in treatment included securing a c... | 298 |
pubmed23n0001_158 | Pneumococcal type-associated variability in alternate complement pathway activation. | Opsonization of Streptococcus pneumoniae may be mediated by the alternate complement pathway. To study the importance of this interaction to human disease, complement consumption by pneumococci of various serotypes was measured in humwn serum chelated with ethyleneglycoltraacetic acid, a substance that blocks the class... | Pneumococcal type-associated variability in alternate complement pathway activation. Opsonization of Streptococcus pneumoniae may be mediated by the alternate complement pathway. To study the importance of this interaction to human disease, complement consumption by pneumococci of various serotypes was measured in humw... | 329 |
pubmed23n0001_163 | Phenomenon of hot-cold hemolysis: chelator-induced lysis of sphingomyelinase-treated erythrocytes. | Staphylococcus aureus produces a phospholipase C specific for sphingomyelin (beta-hemolysin). Erythrocytes with approximately 50% sphingomyelin in their membranes, e.g., from sheep, have been shown to have up to 60% of this phospholipid hydrolyzed by this enzyme at 37 C in isotonic buffered saline without hemolysis. Co... | Phenomenon of hot-cold hemolysis: chelator-induced lysis of sphingomyelinase-treated erythrocytes. Staphylococcus aureus produces a phospholipase C specific for sphingomyelin (beta-hemolysin). Erythrocytes with approximately 50% sphingomyelin in their membranes, e.g., from sheep, have been shown to have up to 60% of th... | 333 |
pubmed23n0001_170 | Characteristics of the non-occluded form of a nuclear polyhedrosis virus. | Non-occluded virions of a nuclear polyhedrosis virus of the alfalfa looper, Autographa californica, found in the medium of cell cultures of infected fall armyworm, Spodopter frugiperda, and in the hemolymph of infected S. frugiperda larvae were partially characterized by biological, chemical and physical methods. Also,... | Characteristics of the non-occluded form of a nuclear polyhedrosis virus. Non-occluded virions of a nuclear polyhedrosis virus of the alfalfa looper, Autographa californica, found in the medium of cell cultures of infected fall armyworm, Spodopter frugiperda, and in the hemolymph of infected S. frugiperda larvae were p... | 343 |
pubmed23n0001_173 | Treatment of severe hypertension with minoxidil. | Minoxidil in daily doses of 6 to 40 mg was administered to 11 patients with severe hypertension. Two patients died of causes unrelated to the drug and one patient withdrew from the study. Blood pressure was controlled in the remaining eight subjects, who received the drug for periods ranging from 5 to 40 months. In thr... | Treatment of severe hypertension with minoxidil. Minoxidil in daily doses of 6 to 40 mg was administered to 11 patients with severe hypertension. Two patients died of causes unrelated to the drug and one patient withdrew from the study. Blood pressure was controlled in the remaining eight subjects, who received the dru... | 346 |
pubmed23n0001_178 | Inactivation of citrate lyase from Rhodopseudomonas gelatinosa by a specific deacetylase and inhibition of this inactivation by L-(+1-glutamate. | A previously unrecognized enzyme, citrate lyase deacetylase, has been purified about 140-fold from cell extracts of Rhodopseudomonas gelatinosa. It catalyzed the conversion of enzymatically active acetyl-S-citrate lyase into the inactive HS-form and acetate. The enzyme exhibited an optimal rate of inactivation at pH 8.... | Inactivation of citrate lyase from Rhodopseudomonas gelatinosa by a specific deacetylase and inhibition of this inactivation by L-(+1-glutamate. A previously unrecognized enzyme, citrate lyase deacetylase, has been purified about 140-fold from cell extracts of Rhodopseudomonas gelatinosa. It catalyzed the conversion of... | 356 |
pubmed23n0001_180 | Formation and cleavage of 2-keto-3-deoxygluconate by 2-keto-3-deoxygluconate aldolase of Aspergillus niger. | 2-Keto-3-deoxygluconate aldolase of Aspergillus niger, an enzyme that has not been reported previously, was purified 468-fold. Maximal activity was obtained at pH 8.0 and 50 C. The enzyme exhibited relative stereochemical specificity with respect to glyceraldehyde. The Km values for 2-keto-3-deoxygluconate, glyceraldeh... | Formation and cleavage of 2-keto-3-deoxygluconate by 2-keto-3-deoxygluconate aldolase of Aspergillus niger. 2-Keto-3-deoxygluconate aldolase of Aspergillus niger, an enzyme that has not been reported previously, was purified 468-fold. Maximal activity was obtained at pH 8.0 and 50 C. The enzyme exhibited relative stere... | 358 |
pubmed23n0001_182 | Phospholipase D activity of gram-negative bacteria. | A phospholipase hydrolyzing cardiolipin to phosphatidic acid and phosphatidyl glycerol was characterized in gram-negative bacteria but was absent in preparations of gram-positive bacteria, Saccharomyces cerevisiae, and rat liver mitochondria. In cell-free extracts of Escherichia coli, Salmonella typhimurium, Proteus vu... | Phospholipase D activity of gram-negative bacteria. A phospholipase hydrolyzing cardiolipin to phosphatidic acid and phosphatidyl glycerol was characterized in gram-negative bacteria but was absent in preparations of gram-positive bacteria, Saccharomyces cerevisiae, and rat liver mitochondria. In cell-free extracts of ... | 360 |
pubmed23n0001_183 | Pyridine nucleotide-linked oxidation of methanol in methanol-assimilating yeasts. | An alcohol dehydrogenase linked to nicotinamide adenine dinucleotide and requiring glutathione has been isolated and partially purified from two methanol-assimilating yeasts. It differs from previously described methanol-oxidizing enzymes in pH optima, electron acceptor specificity, substrate specificity, inhibition pa... | Pyridine nucleotide-linked oxidation of methanol in methanol-assimilating yeasts. An alcohol dehydrogenase linked to nicotinamide adenine dinucleotide and requiring glutathione has been isolated and partially purified from two methanol-assimilating yeasts. It differs from previously described methanol-oxidizing enzymes... | 361 |
pubmed23n0001_187 | 3-Deoxy-D-arabino-heptulosonic acid 7-phosphate synthase mutants of Salmonella typhimurium. | The first committed step of aromatic amino acid biosynthesis in Salmonella typhimurium was shown to be catalyzed by three isoenzymes of 3-deoxy-D-arabino-heptulosonic acid 7-phosphate (DAHP) synthase. Mutations in each of the genes specifying the isoenzymes were isolated and mapped. aroG, the structural gene for the ph... | 3-Deoxy-D-arabino-heptulosonic acid 7-phosphate synthase mutants of Salmonella typhimurium. The first committed step of aromatic amino acid biosynthesis in Salmonella typhimurium was shown to be catalyzed by three isoenzymes of 3-deoxy-D-arabino-heptulosonic acid 7-phosphate (DAHP) synthase. Mutations in each of the ge... | 365 |
pubmed23n0001_188 | Regulation of dihydrodipicolinate synthase during growth and sporulation of Bacillus cereus. | A four- to sixfold increase in specific activity of dihydrodipicolinic acid synthase was observed during sporulation of Bacillus cereus. The enzyme from cells harvested before and after the increase in specific activity appeared to be very similar as judged by pH optima, heat denaturation kinetics, apparent Michaelis c... | Regulation of dihydrodipicolinate synthase during growth and sporulation of Bacillus cereus. A four- to sixfold increase in specific activity of dihydrodipicolinic acid synthase was observed during sporulation of Bacillus cereus. The enzyme from cells harvested before and after the increase in specific activity appeare... | 367 |
pubmed23n0001_189 | Membrane location of a deoxyribonuclease implicated in the genetic transformation of Diplococcus pneumoniae. | The cellular localization of enzymes in Diplococcus pneumoniae was examined by fractionation of spheroplasts. A deoxyribonuclease implicated in the entry of deoxyribonucleic acid (DNA) into the cell during genetic transformation was located in the cell membrane. This enzyme, the major endonuclease of the cell (endonucl... | Membrane location of a deoxyribonuclease implicated in the genetic transformation of Diplococcus pneumoniae. The cellular localization of enzymes in Diplococcus pneumoniae was examined by fractionation of spheroplasts. A deoxyribonuclease implicated in the entry of deoxyribonucleic acid (DNA) into the cell during genet... | 366 |
pubmed23n0001_191 | Purification, new assay, and properties of coenzyme A transferase from Peptostreptococcus elsdenii. | Coenzyme A (CoA) transferase from Peptostreptococcus elsdenii has been purified and crystallized, and some of its properties have been established. The work was facilitated by a newly developed coupled and continuous spectrophotometric assay in which the disappearance of added acrylate could be followed at 245 nm. The ... | Purification, new assay, and properties of coenzyme A transferase from Peptostreptococcus elsdenii. Coenzyme A (CoA) transferase from Peptostreptococcus elsdenii has been purified and crystallized, and some of its properties have been established. The work was facilitated by a newly developed coupled and continuous spe... | 369 |
pubmed23n0001_194 | Simple and sensitive procedure for screening yeast mutants that lyse at nonpermissive temperatures. | After mutagenesis, surviving yeast cells are grown on plates at 25 C and later exposed to 37 C. The plates are then overlaid with a soft agar containing p-nitrophenylphosphate at pH 9.7. Lysed cells liberate alkaline phosphatase which gives rise to a yellow color on and around colonies. | Simple and sensitive procedure for screening yeast mutants that lyse at nonpermissive temperatures. After mutagenesis, surviving yeast cells are grown on plates at 25 C and later exposed to 37 C. The plates are then overlaid with a soft agar containing p-nitrophenylphosphate at pH 9.7. Lysed cells liberate alkaline pho... | 372 |
pubmed23n0001_195 | A nucleoside triphosphate-dependent deoxyribonuclease from Bacillus laterosporus. Purification and characterization of the enzyme. | A deoxyribonuclease, which requires nucleoside triphosphate for reaction, has been purified about 150-fold from extracts of Bacillus laterosporus. Potassium phosphate and ethylene glycol stabilize the purified enzyme. The enzyme degrades double-stranded DNA about 100 times faster than heat-denatured DNA in the presence... | A nucleoside triphosphate-dependent deoxyribonuclease from Bacillus laterosporus. Purification and characterization of the enzyme. A deoxyribonuclease, which requires nucleoside triphosphate for reaction, has been purified about 150-fold from extracts of Bacillus laterosporus. Potassium phosphate and ethylene glycol st... | 373 |
pubmed23n0001_196 | Rapid radioimmunoassay for guanosine 3',5'-cyclic monophosphate using tritiated ligand. | A radioimmunoassay procedure for guanosine 3',5'-cyclic monophosphate (CGMP) is described. The procedure is based on competitive binding between [3H]CGMP and non-radioactive CGMP, with separation of bound and unbound CGMP by Millipore filtration. The binding reaction showed very high specificity to CGMP, had a broad pH... | Rapid radioimmunoassay for guanosine 3',5'-cyclic monophosphate using tritiated ligand. A radioimmunoassay procedure for guanosine 3',5'-cyclic monophosphate (CGMP) is described. The procedure is based on competitive binding between [3H]CGMP and non-radioactive CGMP, with separation of bound and unbound CGMP by Millipo... | 374 |
pubmed23n0001_206 | Effects of strong electrolyte upon the activity of Clostridium perfringens sialidase toward sialyllactose and sialoglycolipids. | Clostridium perfringens sialidase was purified by affinity chromatography. Kinetic properties of the enzyme were examined with sialyllactose and with mixed sialoglycolipids (gangliosides) as substrates. With the latter substrate in 0.01 M Tris-acete in the absence of strong electrolyte, the pH optimum for enzymatic act... | Effects of strong electrolyte upon the activity of Clostridium perfringens sialidase toward sialyllactose and sialoglycolipids. Clostridium perfringens sialidase was purified by affinity chromatography. Kinetic properties of the enzyme were examined with sialyllactose and with mixed sialoglycolipids (gangliosides) as s... | 384 |
pubmed23n0001_208 | sn-Glycerol-3-phosphate acyltransferase activity in particulate preparations from anaerobic, light-grown cells of Rhodopseudomonas spheroides. Involvement of acyl thiolester derivatives of acyl carrier protein in the synthesis of complex lipids. | Crude particulate preparations obtained from anaerobic, light-grown cells of Rhodopseudomonas spheroides have been shown to possess a significant level of sn-glycerol-3-phosphate acyltransferase (EC 2.3.1.15) activity. In contrast to the enzyme from Escherichia coli, the R. spheroides glycerophosphate acyltransferase h... | sn-Glycerol-3-phosphate acyltransferase activity in particulate preparations from anaerobic, light-grown cells of Rhodopseudomonas spheroides. Involvement of acyl thiolester derivatives of acyl carrier protein in the synthesis of complex lipids. Crude particulate preparations obtained from anaerobic, light-grown cells ... | 387 |
pubmed23n0001_211 | Structural studies of two ovalbumin glycopeptides in relation to the endo-beta-N-acetylglucosaminidase specificity. | Heterogeneities of the two ovalbumin glycopeptides, (Man)5(GlcNAc)2Asn and (Man)6(GlcNAc)2Asn, were revealed by borate paper electrophoresis of oligosaccharide alcohols obtained from the glycopeptides by endo-beta-N-acetylglucosaminidase H digestion and NaB3H4 reduction. The structures of the major components of the ol... | Structural studies of two ovalbumin glycopeptides in relation to the endo-beta-N-acetylglucosaminidase specificity. Heterogeneities of the two ovalbumin glycopeptides, (Man)5(GlcNAc)2Asn and (Man)6(GlcNAc)2Asn, were revealed by borate paper electrophoresis of oligosaccharide alcohols obtained from the glycopeptides by ... | 389 |
pubmed23n0001_212 | Use of 5-deazaFAD to study hydrogen transfer in the D-amino acid oxidase reaction. | The apoprotein of hog kidney D-amino acid oxidase was reconstituted with 5-deazaflavin adenine dinucleotide (5-deazaFAD) to yield a protein which contains 1.5 mol of 5-deazaFAD/mol of enzyme. The deazaFAD-containing enzyme forms complexes with benzoate, 2-amino benzoate, and 4-aminobenzoate which are both qualitatively... | Use of 5-deazaFAD to study hydrogen transfer in the D-amino acid oxidase reaction. The apoprotein of hog kidney D-amino acid oxidase was reconstituted with 5-deazaflavin adenine dinucleotide (5-deazaFAD) to yield a protein which contains 1.5 mol of 5-deazaFAD/mol of enzyme. The deazaFAD-containing enzyme forms complexe... | 390 |
pubmed23n0001_213 | The NSILA-s receptor in liver plasma membranes. Characterization and comparison with the insulin receptor. | NSILA-s (nonsuppressible insulin-like activity, soluble in acid ethanol) is a serum peptide that has insulin-like and growth-promoting activities. We have demonstrated previously that liver plasma membranes possess separate receptors for NSILA-s and insulin and have characterized the insulin receptor in detail. In the ... | The NSILA-s receptor in liver plasma membranes. Characterization and comparison with the insulin receptor. NSILA-s (nonsuppressible insulin-like activity, soluble in acid ethanol) is a serum peptide that has insulin-like and growth-promoting activities. We have demonstrated previously that liver plasma membranes posses... | 391 |
pubmed23n0001_214 | Decarboxylation of oxalacetate to pyruvate by purified avian liver phosphoenolpyruvate carboxykinase. | Phosphoenolpyruvate carboxykinase, which has been isolated from chicken liver mitochondria in essentially homogenous form, carries out the irreversible decarboxylation of oxalacetate to pyruvate in the presence of catalytic amounts of GDP or IDP, as well as the reversible decarboxylation of oxalacetate to phosphoenolpy... | Decarboxylation of oxalacetate to pyruvate by purified avian liver phosphoenolpyruvate carboxykinase. Phosphoenolpyruvate carboxykinase, which has been isolated from chicken liver mitochondria in essentially homogenous form, carries out the irreversible decarboxylation of oxalacetate to pyruvate in the presence of cata... | 392 |
pubmed23n0001_215 | Patterns of fatty acid release from endogenous substrates by human platelet homogenates and membranes. | We describe a method for measuring the release of fatty acids from endogenous substrates of human platelet homogenates and membranes. The method depends on the availability of lipids whose fatty acids are odd-chained and therefore suitable as internal reference compounds that, at the time of lipid extraction, can be ad... | Patterns of fatty acid release from endogenous substrates by human platelet homogenates and membranes. We describe a method for measuring the release of fatty acids from endogenous substrates of human platelet homogenates and membranes. The method depends on the availability of lipids whose fatty acids are odd-chained ... | 394 |
pubmed23n0001_216 | Hemoglobin Deer Lodge (beta 2 His replaced by Arg). Consequences of altering the 2,3-diphosphoglycerate binding site. | Hemoglobin Deer Lodge is an abnormal human hemoglobin with arginine substituted for histidine at the beta 2 position. X-ray crystallography of normal human hemoglobin has shown that the beta 2 residue is normally part of the binding site for 2,3-diphosphoglycerate. The substitution of arginine for histidine at beta 2 a... | Hemoglobin Deer Lodge (beta 2 His replaced by Arg). Consequences of altering the 2,3-diphosphoglycerate binding site. Hemoglobin Deer Lodge is an abnormal human hemoglobin with arginine substituted for histidine at the beta 2 position. X-ray crystallography of normal human hemoglobin has shown that the beta 2 residue i... | 393 |
pubmed23n0001_217 | Oxidation of NADPH by submitochondrial particles from beef heart in complete absence of transhydrogenase activity from NADPH to NAD. | Treatment of submitochondrial particles (ETP) with trypsin at 0 degrees destroyed NADPH leads to NAD (or 3-acetylpyridine adenine dinucleotide, AcPyAD) transhydrogenase activity. NADH oxidase activity was unaffected; NADPH oxidase and NADH leads to AcPyAD transhydrogenase activities were diminished by less than 10%. Wh... | Oxidation of NADPH by submitochondrial particles from beef heart in complete absence of transhydrogenase activity from NADPH to NAD. Treatment of submitochondrial particles (ETP) with trypsin at 0 degrees destroyed NADPH leads to NAD (or 3-acetylpyridine adenine dinucleotide, AcPyAD) transhydrogenase activity. NADH oxi... | 395 |
pubmed23n0001_218 | Protein inhibitor of acid deoxyribonucleases. Improved purification procedure and properties. | A method is described for the extensive purification of acid deoxyribonuclease (acid DNase) and its specific inhibitor from beef liver, the existence of which had been only supported by indirect evidence. By the use of insolubilized acid deoxyribonuclease, eight other proteins interacting with the enzyme have been dete... | Protein inhibitor of acid deoxyribonucleases. Improved purification procedure and properties. A method is described for the extensive purification of acid deoxyribonuclease (acid DNase) and its specific inhibitor from beef liver, the existence of which had been only supported by indirect evidence. By the use of insolub... | 396 |
pubmed23n0001_219 | Nucleotide-metabolizing enzymes in Chlamydomonas flagella. | Nucleotides have at least two functions in eukaryotic cilia and flagella. ATP, originating in the cells, is utilized for motility by energy-transducing protein(s) called dynein, and the binding of guanine nucleotides to tubulin, and probably certain transformations of the bound nucleotides, are prerequisites for the as... | Nucleotide-metabolizing enzymes in Chlamydomonas flagella. Nucleotides have at least two functions in eukaryotic cilia and flagella. ATP, originating in the cells, is utilized for motility by energy-transducing protein(s) called dynein, and the binding of guanine nucleotides to tubulin, and probably certain transformat... | 397 |
pubmed23n0001_222 | Trypsin-sensitive photosynthetic activities in chloroplast membranes from Chlamydomonas reinhardi, y-1. | Location of electron transport chain components in chloroplast membranes of chlamydomonas reinhardi, y-1 was investigated by use of proteolytic digestion with soluble or insolubilized trypsin. Digestion of intact membrane vesicles with soluble trypsin inactivates the water-splitting system, the 3-(3,4-dichlorophenyl)-1... | Trypsin-sensitive photosynthetic activities in chloroplast membranes from Chlamydomonas reinhardi, y-1. Location of electron transport chain components in chloroplast membranes of chlamydomonas reinhardi, y-1 was investigated by use of proteolytic digestion with soluble or insolubilized trypsin. Digestion of intact mem... | 400 |
pubmed23n0001_225 | Biochemical studies of tast sensation. Binding of L-[3H]alanine to a sedimentable fraction from catfish barbel epithelium. | Large numbers of taste buds are distributed over the body surface of the channel catfish ictalurus punctatus, with the barbels having an especially high density. L-Alanine, as well as certain other amino acids, are taste stimuli in this animal. Epithelial tissue obtained by gentle scraping of the barbel surface was fra... | Biochemical studies of tast sensation. Binding of L-[3H]alanine to a sedimentable fraction from catfish barbel epithelium. Large numbers of taste buds are distributed over the body surface of the channel catfish ictalurus punctatus, with the barbels having an especially high density. L-Alanine, as well as certain other... | 403 |
pubmed23n0001_228 | Localization of NADH oxidase on the surface of human polymorphonuclear leukocytes by a new cytochemical method. | The ultrastructural localization of NADH oxidase, a possible enzyme in the increased oxidative activity of polymorphonuclear leukocytes (PMN) during phagocytosis, was studied. A new cytochemical technique for the localization of H2O2, a product of NADH oxidase activity, was developed. Cerous ions, in the presence of pe... | Localization of NADH oxidase on the surface of human polymorphonuclear leukocytes by a new cytochemical method. The ultrastructural localization of NADH oxidase, a possible enzyme in the increased oxidative activity of polymorphonuclear leukocytes (PMN) during phagocytosis, was studied. A new cytochemical technique for... | 407 |
pubmed23n0001_235 | Purification of human red cell glucose 6-phosphate dehydrogenase by affinity chromatography. | Human glucose 6-phosphate dehydrogenase associated with NADPH was efficiently bound with agarose-bound NADP, whereas the enzyme associated with NADP was poorly bound with agarose-bound NADP. After the elimination of haemoglobin from haemolyzate by treatment with DEAE-cellulose, the enzyme was converted into the NADPH-b... | Purification of human red cell glucose 6-phosphate dehydrogenase by affinity chromatography. Human glucose 6-phosphate dehydrogenase associated with NADPH was efficiently bound with agarose-bound NADP, whereas the enzyme associated with NADP was poorly bound with agarose-bound NADP. After the elimination of haemoglobin... | 416 |
pubmed23n0001_239 | Determination of 3-(5-tetrazolyl) thioxanthone 10,10-dioxide in human plasma, urine and faeces. | A gas chromatographic method is described for assay of 3-(5-tetrazolyl) thioxanthone 10,10-dioxide (BW 59C) in human plasma, urine and faeces. After extraction into 1,2-dichloroethane from alkaline medium the compound is converted to the heptafluorobutyrate derivative which is injected into a gas chromatograph and meas... | Determination of 3-(5-tetrazolyl) thioxanthone 10,10-dioxide in human plasma, urine and faeces. A gas chromatographic method is described for assay of 3-(5-tetrazolyl) thioxanthone 10,10-dioxide (BW 59C) in human plasma, urine and faeces. After extraction into 1,2-dichloroethane from alkaline medium the compound is con... | 420 |
pubmed23n0001_240 | Methods to improve detection of pneumococci in respiratory secretions. | Simple methods to enhance the detection of pneumococci in respiratory secretions are needed. Sheep blood agar containing 5 mug of gentamicin per ml was more often positive (89%) than either standard sheep blood agar (54%) or mouse inoculation (65%) in recovering pneumococci from 62 adult and pediatric patients. In adul... | Methods to improve detection of pneumococci in respiratory secretions. Simple methods to enhance the detection of pneumococci in respiratory secretions are needed. Sheep blood agar containing 5 mug of gentamicin per ml was more often positive (89%) than either standard sheep blood agar (54%) or mouse inoculation (65%) ... | 421 |
pubmed23n0001_248 | Peroxisome development in the metanephric kidney of mouse. | The relationship of enzymatic activity to organelle development and organelle number during differentiation of the metanephric kidney in the mouse was approached from several experimental directions. Biochemical analyses of marker enzymes for peroxisomes (catalase and D-amino acid oxidase), mitochondria (cytochrome oxi... | Peroxisome development in the metanephric kidney of mouse. The relationship of enzymatic activity to organelle development and organelle number during differentiation of the metanephric kidney in the mouse was approached from several experimental directions. Biochemical analyses of marker enzymes for peroxisomes (catal... | 440 |
pubmed23n0001_252 | The innervation of the salivary gland of the moth, Manduca sexta: evidence that dopamine is the transmitter. | 1. Using the Falck-Hillarp histochemical technique for monoamines, evidence was found for the presence of a catecholamine in the salivary gland nerves of the moth, Manduca sexta. 2. The innervation was studied with the electron microscope. Only the fluid-secreting region of the gland is innervated and the nerve endings... | The innervation of the salivary gland of the moth, Manduca sexta: evidence that dopamine is the transmitter. 1. Using the Falck-Hillarp histochemical technique for monoamines, evidence was found for the presence of a catecholamine in the salivary gland nerves of the moth, Manduca sexta. 2. The innervation was studied w... | 448 |
pubmed23n0001_254 | The selective eosinophil chemotactic activity of histamine. | Histamine diphosphate was shown to selectively attract human eosinophils from mixed granulocyte populations when over 20% eosinophils were used in a modified Boyden chamber chemotactic assay system. This effect of histamine is abolished by incubation with diamine oxidase (histaminase) and was generated by decarboxylati... | The selective eosinophil chemotactic activity of histamine. Histamine diphosphate was shown to selectively attract human eosinophils from mixed granulocyte populations when over 20% eosinophils were used in a modified Boyden chamber chemotactic assay system. This effect of histamine is abolished by incubation with diam... | 450 |
pubmed23n0001_257 | Photoreceptor processes: some problems and perspectives. | Visual photoreceptors from both vertebrates and invertebrates are characterized by extensive elaboration of membrane which contains visual pigment (rhodopsin). Visual pigments in all phyla examined are chemically similar: the chromophore is 11-cis retinaldehyde attached by an aldimine linkage (Schiff base) to a membran... | Photoreceptor processes: some problems and perspectives. Visual photoreceptors from both vertebrates and invertebrates are characterized by extensive elaboration of membrane which contains visual pigment (rhodopsin). Visual pigments in all phyla examined are chemically similar: the chromophore is 11-cis retinaldehyde a... | 453 |
pubmed23n0001_259 | Some effects of low pH on chloride exchange in human red blood cells. | In order to test the range of pH values over which the titratable carried model for inorganic anion exchange is valid, chloride self-exchange across human red blood cells was examined between pH 4.75 and 5.7 at 0 decrees c. It was found that chloride self-exchange flux had a minimum near pH 5 and increased again with f... | Some effects of low pH on chloride exchange in human red blood cells. In order to test the range of pH values over which the titratable carried model for inorganic anion exchange is valid, chloride self-exchange across human red blood cells was examined between pH 4.75 and 5.7 at 0 decrees c. It was found that chloride... | 459 |
pubmed23n0001_260 | Ionic properties of the acetylcholine receptor in cultured rat myotubes. | The acetylcholine reversal potential (Er) of cultured rat myotubes is -3mV. When activated, the receptor is permeable to K+ and Na+, but not to Cl- ions. Measurement of Er in Tris+-substituted, Na-free medium also indicated a permeability to Tris+ ions. Unlike adult frog muscle the magnitude of Er was insensitive to ch... | Ionic properties of the acetylcholine receptor in cultured rat myotubes. The acetylcholine reversal potential (Er) of cultured rat myotubes is -3mV. When activated, the receptor is permeable to K+ and Na+, but not to Cl- ions. Measurement of Er in Tris+-substituted, Na-free medium also indicated a permeability to Tris+... | 460 |
pubmed23n0001_262 | Chitin synthase in Mortierella vinacea: properties, cellular location and synthesis in growing cultures. | Chitin synthase of Mortierella vinacea was present in the "microsomal' fraction (100 000 g precipitate), the 'cell-wall' fraction (2000 g precipitate) and the 'mitochondrial' fraction (10 000 g precipitate). The properties of the 'microsomal' enzyme were investigated. The pH optimum was between 5-8 and 6-2, and the tem... | Chitin synthase in Mortierella vinacea: properties, cellular location and synthesis in growing cultures. Chitin synthase of Mortierella vinacea was present in the "microsomal' fraction (100 000 g precipitate), the 'cell-wall' fraction (2000 g precipitate) and the 'mitochondrial' fraction (10 000 g precipitate). The pro... | 462 |
pubmed23n0001_263 | Protoplasts of Schizosaccharomyces pombe: an improved method for their preparation and the study of their guanine uptake. | A new method is described for the efficient conversion of Schizosaccharomyces pombe cells into protoplasts. The following parameters of guanine uptake determined in whole cells were unchanged in protoplasts: Km value, requirement for an energy source, sensitivity to competitive inhibitors, pH optimum, as well as the ty... | Protoplasts of Schizosaccharomyces pombe: an improved method for their preparation and the study of their guanine uptake. A new method is described for the efficient conversion of Schizosaccharomyces pombe cells into protoplasts. The following parameters of guanine uptake determined in whole cells were unchanged in pro... | 463 |
pubmed23n0001_264 | Manganese mutagenesis in yeast. A practical application of manganese for the induction of mitochondrial antibiotic-resistant mutations. | When yeast cells were incubated for 4 to 8 h in yeast extract-peptone-glucose medium, pH 6, containing 8 mM-manganese, and then plated on selective media, there was a strong induction of antibiotic-resistant mutations. Indirect evidence suggests that practically all resistant mutants selected were of independent origin... | Manganese mutagenesis in yeast. A practical application of manganese for the induction of mitochondrial antibiotic-resistant mutations. When yeast cells were incubated for 4 to 8 h in yeast extract-peptone-glucose medium, pH 6, containing 8 mM-manganese, and then plated on selective media, there was a strong induction ... | 464 |
pubmed23n0001_265 | The properties and large-scale production of L-asparaginase from citrobacter. | An intracellular L-asparaginase with antitumour activity was purified from a strain of Citrobacter. The optimum conditions for enzyme production by fermentation on scales up to 2700 l were investigated. Highest enzyme yield was obtained in corn-steep liquor medium (9-2%, W/V) at 37 degrees C. Oxygen limitation was not ... | The properties and large-scale production of L-asparaginase from citrobacter. An intracellular L-asparaginase with antitumour activity was purified from a strain of Citrobacter. The optimum conditions for enzyme production by fermentation on scales up to 2700 l were investigated. Highest enzyme yield was obtained in co... | 465 |
pubmed23n0001_266 | Effect of inorganic phosphate on acridine inhibition and plasmid curing in Escherichia coli. | Some mutants and stock strains of Escherichia coli K12 were sensitive to acriflavine in the presence of inorganic phosphate but were resistant to acriflavine in its absence. They mutated spontaneously to resistance to acriflavine plus phosphate. The synergistic effect of phosphate on acriflavine sensitivity was increas... | Effect of inorganic phosphate on acridine inhibition and plasmid curing in Escherichia coli. Some mutants and stock strains of Escherichia coli K12 were sensitive to acriflavine in the presence of inorganic phosphate but were resistant to acriflavine in its absence. They mutated spontaneously to resistance to acriflavi... | 466 |
pubmed23n0001_269 | Experimental evaluation of the spasmogenicity of dopamine on the basilar artery. | Arteriograms of the basilar artery reveal that dopamine given intracisternally to dogs can generate cerebral vasospasm. This finding supports a recent hypothesis of others that dopamine may play a role in the pathogenesis of vasospasm, especially since many substances are known which fail to produce such spasm. Compare... | Experimental evaluation of the spasmogenicity of dopamine on the basilar artery. Arteriograms of the basilar artery reveal that dopamine given intracisternally to dogs can generate cerebral vasospasm. This finding supports a recent hypothesis of others that dopamine may play a role in the pathogenesis of vasospasm, esp... | 472 |
pubmed23n0001_271 | Some mechanisms of reduction of carotenoid levels in chickens infected with Eimeria acervulina or E. tenella. | The levels of plasma carotenoids were markedly reduced in broiler cockerels infected with Eimeria acervulina or E. tenella. The mechanisms of this depigmentation differed between the two species, being primarily associated with interference of absorption of xanthophyll (carotenoids) from the intestinal lumen with E. ac... | Some mechanisms of reduction of carotenoid levels in chickens infected with Eimeria acervulina or E. tenella. The levels of plasma carotenoids were markedly reduced in broiler cockerels infected with Eimeria acervulina or E. tenella. The mechanisms of this depigmentation differed between the two species, being primaril... | 476 |
pubmed23n0001_274 | Recognition and significance of maternogenic fetal acidosis during intensive monitoring of labor. | FHR monitoring and microanalysis of fetal blood are mutually complementary procedures, and optimal knowledge of the fetal state is achieved by making use of both, the former for the preliminary screening of all cases at risk and the latter for the purpose of deciding on obstetric management where pathological changes a... | Recognition and significance of maternogenic fetal acidosis during intensive monitoring of labor. FHR monitoring and microanalysis of fetal blood are mutually complementary procedures, and optimal knowledge of the fetal state is achieved by making use of both, the former for the preliminary screening of all cases at ri... | 480 |
pubmed23n0001_283 | Studies on the mechanism of depletion of striatal dopamine by alpha-methyl-m-tyrosine. | These experiments were designed to study the mechanism of depletion of dopamine (DA) in the striatum produced by alpha-methyl-m-tyrosine (alpha-MMT). alpha-Methyl-m-tyramine (alpha-MMTA), the metabolite of alpha-MMT, appears to be the active DA-depleting agent, since the administration of a decarboxylase inhibitor befo... | Studies on the mechanism of depletion of striatal dopamine by alpha-methyl-m-tyrosine. These experiments were designed to study the mechanism of depletion of dopamine (DA) in the striatum produced by alpha-methyl-m-tyrosine (alpha-MMT). alpha-Methyl-m-tyramine (alpha-MMTA), the metabolite of alpha-MMT, appears to be th... | 490 |
pubmed23n0001_288 | Comparative studies of Trypanosoma vespertilionis Battaglia and Trypanosoma dionisii Bettencourt & França. | In diphasic blood agar media Trypanosoma vespertilionis developed spheroid clusters as compared to rather long, sausage-shaped (sometimes branched) clusters formed by Trypanosoma dionisii. The former species attained a greater population density (approximately 6 X 10(7) organisms/ml) than the latter (approximately 2 X ... | Comparative studies of Trypanosoma vespertilionis Battaglia and Trypanosoma dionisii Bettencourt & França. In diphasic blood agar media Trypanosoma vespertilionis developed spheroid clusters as compared to rather long, sausage-shaped (sometimes branched) clusters formed by Trypanosoma dionisii. The former species a... | 495 |
pubmed23n0001_296 | Bacteriophage T4 baseplate components. II. Binding and location of bacteriophage-induced dihydrofolate reductase. | The location of T4D phage-induced dihydrofolate reductase (dfr) has been determined in intact and incomplete phage particles. It has been found that phage mutants inducing a temperature-sensitive dfr (dfrts) procude heat-labile phage particles. The structural dfr produced by these ts mutants was shown to assume differe... | Bacteriophage T4 baseplate components. II. Binding and location of bacteriophage-induced dihydrofolate reductase. The location of T4D phage-induced dihydrofolate reductase (dfr) has been determined in intact and incomplete phage particles. It has been found that phage mutants inducing a temperature-sensitive dfr (dfrts... | 516 |
pubmed23n0001_302 | Multiple cyclic nucleotide phosphodiesterases in rat kidney. | Using DEAE-cellulose chromatography and Agarose gel filtration we have partially purified a low Km cyclic adenosine monophosphate (AMP) phosphodiesterase from the 100,000 X g supernatant of rat kidneys. The characteristics of this enzyme included a Km of approximately 4 muM a pH optimum of around 8.0 and a requirement ... | Multiple cyclic nucleotide phosphodiesterases in rat kidney. Using DEAE-cellulose chromatography and Agarose gel filtration we have partially purified a low Km cyclic adenosine monophosphate (AMP) phosphodiesterase from the 100,000 X g supernatant of rat kidneys. The characteristics of this enzyme included a Km of appr... | 537 |
pubmed23n0001_304 | [Immune mechanisms in uremia]. | There is both clinical and experimental evidence that cellular and humoral immunity are suppressed in patients with renal insufficiency: observations in organ transplantation and in vitro stimulation of lymphocytes from uraemic patients, investigations of acute and late hypersensitivity reactions, the immune response a... | [Immune mechanisms in uremia]. There is both clinical and experimental evidence that cellular and humoral immunity are suppressed in patients with renal insufficiency: observations in organ transplantation and in vitro stimulation of lymphocytes from uraemic patients, investigations of acute and late hypersensitivity r... | 540 |
pubmed23n0001_312 | The late effects of selected immunosuppressants on immunocompetence, disease incidence, and mean life-span. II. Cell-mediated immune activity. | The late effects of various immunosuppressive insults on cell-mediated immunity in mice were studied in an attempt to assess the role of immune surveillance in the aging process. Results were obtained using susceptibility to allogeneic tumor cell challenge, graft-versus-host reaction (GVHR), blastogenic response to PHA... | The late effects of selected immunosuppressants on immunocompetence, disease incidence, and mean life-span. II. Cell-mediated immune activity. The late effects of various immunosuppressive insults on cell-mediated immunity in mice were studied in an attempt to assess the role of immune surveillance in the aging process... | 562 |
pubmed23n0001_316 | Phosphate transport in rat liver mitochondria. Kinetics, inhibitor sensitivity, energy requirements, and labeled components. | Experiments were carried out to define the kinetic parameters of the major phosphate transport processes of rat liver mitochondria, and to obtain information about the molecular properties of these systems. | Phosphate transport in rat liver mitochondria. Kinetics, inhibitor sensitivity, energy requirements, and labeled components. Experiments were carried out to define the kinetic parameters of the major phosphate transport processes of rat liver mitochondria, and to obtain information about the molecular properties of the... | 609 |
pubmed23n0001_317 | L-tyrosine: 2-oxoglutarate aminotransferase induction by hydrocortisone in the thymus of the white rat. | Hydrocortisone hemisuccinate within 4 hours after in vivo administration produced an increase in precursor incoporation into rat thymus RNA and proteins in the whole animal. From these results, together with information obtained from measurements of the tyrosine aminotransferase activity and the action of mitomycin C a... | L-tyrosine: 2-oxoglutarate aminotransferase induction by hydrocortisone in the thymus of the white rat. Hydrocortisone hemisuccinate within 4 hours after in vivo administration produced an increase in precursor incoporation into rat thymus RNA and proteins in the whole animal. From these results, together with informat... | 610 |
pubmed23n0001_318 | Identification of the 30 S protein adjacent to peptidyl transferase catalytic center of Escherichia coli ribosomes. | Iodoacetylphenylalanyl-tRNAPhe was used as an affinity label to localize the ribosomal components involved in the peptidyl transferase catalytic center of Escherichia coli ribosomes. When labeling was carried out at pH 5.0, the affinity label could specifically label the ribosomal components which comprise the catalyti... | Identification of the 30 S protein adjacent to peptidyl transferase catalytic center of Escherichia coli ribosomes. Iodoacetylphenylalanyl-tRNAPhe was used as an affinity label to localize the ribosomal components involved in the peptidyl transferase catalytic center of Escherichia coli ribosomes. When labeling was car... | 611 |
pubmed23n0001_323 | The regulation of striatal tyrosine hydroxylase. Effects of gamma hydroxybutric acid and healperidol. | Gamma-hydroxybutyric acid (GHBA) in doses that increased the striatal dopamine (DA) content of rat brain failed to increase the affinity of striatal tyrosine hydroxylase (TH) for its pterdine cofactor or to change the sensitivity of the enzyme to the inhibition by DA. Haloperidol (1 mg/kg) decreased the apparent Km of ... | The regulation of striatal tyrosine hydroxylase. Effects of gamma hydroxybutric acid and healperidol. Gamma-hydroxybutyric acid (GHBA) in doses that increased the striatal dopamine (DA) content of rat brain failed to increase the affinity of striatal tyrosine hydroxylase (TH) for its pterdine cofactor or to change the ... | 629 |
pubmed23n0001_331 | Identification, purification and properties of clone-specific glycoprotein antigens constituting the surface coat of Trypanosoma brucei. | Soluble glycoproteins have been purified from a series of clones of Trypanosoma brucei 427. Each clone yielded a characteristic predominant glycoprotein which induced clone-specific immunity to trypanosome infection in mice. These glycoproteins were shown by specific labelling and enzyme digestion of cells to be the ma... | Identification, purification and properties of clone-specific glycoprotein antigens constituting the surface coat of Trypanosoma brucei. Soluble glycoproteins have been purified from a series of clones of Trypanosoma brucei 427. Each clone yielded a characteristic predominant glycoprotein which induced clone-specific i... | 645 |
pubmed23n0001_343 | Light-dependent absorption and selective scattering changes at 518 nm in chloroplast thylakoid membranes. | The light-induced absorbance change at 518 nm of isolated chloroplasts consists of a rapid phase, and a slow phase which is complete in about 20 sec. The slow component of the 518 nm absorbance change correlates with the light-induced change in 90 degrees light scattering at 518 nm. Both show a similar time course, sim... | Light-dependent absorption and selective scattering changes at 518 nm in chloroplast thylakoid membranes. The light-induced absorbance change at 518 nm of isolated chloroplasts consists of a rapid phase, and a slow phase which is complete in about 20 sec. The slow component of the 518 nm absorbance change correlates wi... | 669 |
pubmed23n0001_346 | Ubiquinone-mediated coupling of NADH dehydrogenase to active transport in membrane vesicles from Escherichia coli. | Addition of ubiquinone-1 to E. coli ML 308-225 membrane vesicles dramatically increases coupling between NADH oxidation and active transport such that initial rates and steady-state levels of lactose and amino-acid accumulation are comparable to those observed during D-lactate oxidation. Similar but less dramatic effec... | Ubiquinone-mediated coupling of NADH dehydrogenase to active transport in membrane vesicles from Escherichia coli. Addition of ubiquinone-1 to E. coli ML 308-225 membrane vesicles dramatically increases coupling between NADH oxidation and active transport such that initial rates and steady-state levels of lactose and a... | 672 |
pubmed23n0001_350 | Purification of folate binding factor in normal umbilical cord serum. | Human umbilical cord serum was found to contain both free folate and folate complexed to a high-molecular weight factor. The complexed folate was bound to a very high affinity binder and was present in concentrations equivalent to as much as 60 ng of 5-methyltetrahydrofolic acid per ml of serum. Acidification of the se... | Purification of folate binding factor in normal umbilical cord serum. Human umbilical cord serum was found to contain both free folate and folate complexed to a high-molecular weight factor. The complexed folate was bound to a very high affinity binder and was present in concentrations equivalent to as much as 60 ng of... | 676 |
pubmed23n0001_358 | The effect of L-dopa on young patients with simple schizophrenia, treated with neuroleptic drugs: a double-blind cross-over trial with Madopar and placebo. | Thirteen out of 18 young out-patients with simple schizophrenia under neuroleptic treatment completed a double-blind cross-over trial with Madopar [L-Dopa + benserazid (a peripheral decarboxylase inhibitor)] and placebo. Nine patients were given 900 mg L-Dopa + 225 mg benserazid daily, 1 patient received 600 mg L-Dopa ... | The effect of L-dopa on young patients with simple schizophrenia, treated with neuroleptic drugs: a double-blind cross-over trial with Madopar and placebo. Thirteen out of 18 young out-patients with simple schizophrenia under neuroleptic treatment completed a double-blind cross-over trial with Madopar [L-Dopa + bensera... | 706 |
pubmed23n0001_359 | The specificity of binding of the narcotic agonist etorphine in synaptic membranes of rat brain in vivo. | When 3H-etorphine was administered to rats in a pharmacologically effective dose (0.75 mug/kg intracisternally), the labeled drug was concentrated in synaptic membrane fractions isolated from the brains of rats killed 10 min after etorphine injection. Pretreatment of the animals with the narcotic antagonists naloxone, ... | The specificity of binding of the narcotic agonist etorphine in synaptic membranes of rat brain in vivo. When 3H-etorphine was administered to rats in a pharmacologically effective dose (0.75 mug/kg intracisternally), the labeled drug was concentrated in synaptic membrane fractions isolated from the brains of rats kill... | 707 |
pubmed23n0001_360 | The cholinergic system and nociception in the primate: interactions with morphine. | In Experiment 1 the shock titration task was used to evaluate the antinoceptive properties of 5 different classes of cholinergic compounds in the rhesus monkey. Only scopolamine and high doses of physostigmine were effective in elevating the shock threshold. The apparent antinociceptive effect of physostigmine, however... | The cholinergic system and nociception in the primate: interactions with morphine. In Experiment 1 the shock titration task was used to evaluate the antinoceptive properties of 5 different classes of cholinergic compounds in the rhesus monkey. Only scopolamine and high doses of physostigmine were effective in elevating... | 708 |
Subsets and Splits
No community queries yet
The top public SQL queries from the community will appear here once available.