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Biomedical subjects

S Svensson

Publications and source records attributed to S Svensson.

At least 145 records · Page 8Linked to original sources
PubMed1978

Effect of age and diet on delta-aminolevulinic acid dehydratase in red blood cells.

ALA-D activity measured in the red blood cells of different species show considerable variations. Among the adult animals, rabbits have the highest activity and dogs, the lowest. It is a zinc-dependent enzyme and its activity is related to the age of the animals as well as the availability of zinc in the diet during the early growth period. Rats at partus have the highest ALA-D activity ever registered in any animal species and it decreases drastically during the early growth period. The red blood cells of newborn human babies have 50% higher ALA-D activity than that of adult man. When rats during their early growth period are fed on a diet containing 0.08 mmol zinc, there was a reduction in the enzyme activity whereas adult rats fed on diets containing higher and lower amounts of zinc did not show any change.

Adult↗
PubMed1976

Quantitation of a urinary tetrasaccharide by gas chromatography and mass spectrometry.

A gas chromatographic mass spectrometric method has been developed for the rapid determination of a urinary tetrasaccharide (alpha-D-Glc-(1 leads to 6)-alpha-D-Glc-(1 leads to 4)-alpha-D-Glc-(1 leads to 4)-D-Glc). The urine sample is first fractionated by gel chromatography. An appropriate internal standard is added to the pooled tri-pentasaccharide fraction, which is then reduced, methylated and fractionated by g.c. The identification of the tetrasaccharide derivative is based on the g.c. relative retention time and the mass spectrum of the reduced permethylated tetrasaccharide. The normal excretion rate was in the range of 0.1-2.5 mg per 24 hours. Greatly increased amounts (9.4-89.6 mg 24 h-1) were found in the urine of patients with glycogen storage disease type II and type III and in one patient with unclassified muscular disease. A moderate increase (3.6m6 mg 24 h-1) was observed in one patient with glycogen storage disease type VI, in two patients with Duchenne muscular dystrophy and in two other patients with unclassified muscular disease.

Adolescent↗
PubMed1976

An improved method for synthesising omega-stearoyldextran for the detection of plaque forming cells specific for the alpha-(1 replaces 6) determinant.

A method for synthesising omega-stearoyldextran for the detection of plaque forming cells specific for the alpha-(1 replaces 6) determinant is described. The omega-stearoyl derivative is obtained by reacting dextran with phenylboronic acid to give a 2,4-phenylboronate, which can be subsequently esterified in a pyridine solution with stearoyl chloride. Four different preparations of omega-stearoyldextran with increasing content of stearoyl were obtained. Chemical and immunochemical properties of these compounds are given.

Animals↗
PubMed1975

A urinary pentasaccharide in bovine mannosidosis.

Abnormally high amounts of low molecular weight mannose-rich carbohydrate material were found in the urine of an Angus calf with mannosidosis. At least five oligosaccharide fractions were detected by paper chromatography. The most abundant compound was purified by gel chromatography, zone electrophoresis, and two consecutive preparative paper chromatographic steps. The yield was 10 mg/liter of urine. From structural studies including nuclear magnetic resonance spectroscopy, optical rotation, sugar analysis, methylation analysis, and partial enzymatic degradation the following structure was deduced: alpha-D-Manp-(1 leads to 6)-beta-D-Manp-(1 leads to 4)-beta-D-GlcNAcp-(1 leads to 4)-beta-D-GlcNAcp-(1 leads to 4)-D-GlcNAc. This oligosaccharide is distinct from all the oligosaccharides previously described which are excreted by patients with mannosidosis.

Acetylglucosamine↗
PubMed1975

A new type of carbohydrate-protein linkage in a glycopeptide from normal human urine.

A glycopeptide, 3-O-beta-D-glucopyranosyl-alpha-L-fucopyranosyl-L-threonine, has been isolated from normal human urine. The glycopeptide was isolated by gel chromatography, preparative zone electrophoresis, paper chromatography, and high voltage electrophoresis. The average yield of the glycopeptide was in the range of 0.2 to 0.3 mg/liter of urine. Sugar analysis and amino acid analysis gave equimolar amounts of glucose, fucose, and threonine. Linkages and sequential order were established by methylation analysis of the glycopeptide after degradation of the amino acid residue with ninhydrin. The permethylated product was analyzed on gas liquid chromatography and mass spectrometry. Anomeric configuration was deduced from optical rotation.

Chromatography, Gas↗
PubMed1975

The structure of capsular polysaccharide of the Pneumococcus type II.

The pneumococcus type II capsular polysaccharide (SII) is composed of singly-branched hexasaccharide repeating units, for which three alternative structures have been proposed. The correct structure has now been determined by consecutive eliminations of the sugar residues in the side chain. The terminal D-glucuronic acid group was eliminated by treating the fully methylated and esterified SIIpolysaccharide first with base, and then with weak acid. The hydroxyl group at C-6 in the penultimate D-glucose residue released by this elimination was transformed into the 6-deoxy-6-tosyl derivative, and the residue thereafter eliminated by treatment with base. As the side-chains were eliminated by these reactions, it is considered that they contain only two sugar residues, which thus excludes two of the three alternative structures. Structure 1 was further confirmed by subjecting SII to a Smith degradation, which yielded the tetrasaccharide L-Rhap-(1 yields 3)-L-Rhap-(1 yields 3)-L-Rhap-(1 yields 2-erythritol, characterised by methylation analysis.

Chromatography, Gas↗
PubMed1975

Nature of the tumor-associated determinant(s) of carcinoembryonic antigen.

The carbohydrate moiety of carcinoembryonic antigen could be sequentially degraded by repeated cycles of periodate oxidation, reduction, and mild acid hydrolysis (Smith degradation). After three complete degradations, all fucose and sialic acid, 80% of the galactose, 65% of the mannose, and about 40% of the N-acetylglucosamine were eliminated without impairing the ability of degraded carcinoembryonic antigen to react with specific antisera against the antigen. Inhibition studies in a carcinoembryonic antigen/rabbit anti-carcinoembryonic antigen precipitating system with oligosaccharides covering previously known internal structures of glycoproteins and presumably corresponding to the internal carbohydrate region of the antigen, demonstrated that none of the compounds tested was inhibitory. Nor could any inhibitory effect on the binding of carcinoembryonic antigen to antibody against the antigen in a radioimmunoassay system be domonstrated for the carbohydrate moiety prepared by hydrazinolysis or the glyco peptide fraction isolated after papain degradation of the antigen. However, if carcinoembryonic antigen is completely reduced and alkylated, with three intrachain disulfide bonds cleaved per 10-5 g, the immunological activity is reduced to 3-5% of untreated antigen. Furthermore, treatment of the antigen with 0.5 NaOH at 20 degrees for 2 hr completely abolished its ability to react with antiserum, whereas its ability to precipitate with a series of lectins was unchanged. No release of low-molecular-weight carbohydrate orchange in sugar composition of alkali-treated antigen was observed. Our tentative conclusion is that the carbohydrate moiety of carcinoembryonic antigen does not contain the tumor-associated determinant(s).

Acetylgalactosamine↗
PubMed1975

Salmonella typhimurium mutations conferring resistance to Felix O phage without loss of smooth character: phage attachment and immunochemical and structural analyses of lipopolysaccharides.

Salmonella typhimurium mutants, called Felix O-resistant (FOR), selected for resistance to phage Felix O (FO) which has its receptor in the core lipopolysaccharide (LPS), retain most of the properties of the smooth parent strain (MacPhee, Krishnapillai, Roantree & Stocker, 1975). LPS extracted from one parent and two FOR strains by the phenol-water and the phenol-chloroform-light petroleum methods have been subjected to passive haemagglutination inhibition and methylation analysis. The amount of LPS, the amount of O-specific sugars in the LPS, and the average length of the O chains were almost the same in parent and mutant strains. Neither passive haemagglutination nor methylation analysis revealed the presence of incomplete cores in the mutant strains. Determination of the rates of attachment of P22 (receptor in O chain) and FO phages to whole bacteria of the same strains also suggested there is as much O-chain material in the FOR strains as in the parent strain. The data suggest that the FOR strains are the result of a mutation in the synthesis of the core, leaving few, if any, completed cores accessible to the FO phage.

Adsorption↗