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Biomedical subjects

G Reuter

Publications and source records attributed to G Reuter.

At least 163 records · Page 9Linked to original sources
PubMed1984

Allergy to 2 new corticoid molecules.

6 cases of hypersensitivity to Tixocortol pivalate and 3 to Amcinonide are reported. The 9 female patients all presented with features of contact dermatitis.

Administration, Topical↗
PubMed1984

Identification of a disialoganglioside (GD1a) containing terminal N-acetyl-9-O-acetylneuraminic acid in rat erythrocytes.

Gangliosides containing 350 micrograms of sialic acids were isolated from 2.85 X 10(11) rat erythrocytes and found to be mainly composed of GD1a and an unknown alkali-labile species which was converted to GD1a after treatment with ammonia. Smaller amounts of GM1 and Fuc-GM1 were also present. Identification of the sialic acids of the novel species by thin-layer chromatography, high performance liquid chromatography and gas-liquid chromatography--mass spectrometry revealed the presence of both N-acetylneuraminic acid and N-acetyl-9-O-acetyl-neuraminic acid in about equimolar amounts. Incubation of the isolated ganglioside with Vibrio cholerae sialidase released N-acetyl-9-O-acetyl-neuraminic acid. Non O-acetylated GM1 was identified as the only remaining ganglioside by thin-layer chromatography. Thus this novel ganglioside has the following structure: Neu5,9Ac2 alpha 2-3Gal beta 1-3GalNAc beta 1-4(Neu5Ac alpha-2-3)Gal beta 1-4Glc beta 1-1'Cer.

Animals↗
PubMed1983

Identification of new sialic acids derived from glycoprotein of bovine submandibular gland.

Improvements in the isolation procedure and the analytical equipment enabled the detection of seven novel sialic acids in bovine submandibular gland glycoprotein: N-acetyl-8-O-acetylneuraminic acid, N-acetyl-8,9-di-O-acetylneuraminic acid, N-acetyl-7,8,9-tri-O-acetylneuraminic acid, N-glycoloyl-7-O-acetylneuraminic acid, N-glycoloyl-7,9-di-O-acetylneuraminic acid, N-glycoloyl-8,9-di-O-acetylneuraminic acid, and N-glycoloyl-7,8,9-tri-O-acetylneuraminic acid. There are also indications for the presence of N-glycoloyl-8-O-acetylneuraminic acid. In addition, the sialic acids already known to occur in this tissue, namely N-acetylneuraminic acid, N-acetyl-7-O-acetylneuraminic acid, N-acetyl-9-O-acetylneuraminic acid, N-acetyl-7,9-di-O-acetylneuraminic acid, N-glycoloylneuraminic acid, and N-glycoloyl-9-O-acetylneuraminic acid could be identified. Sialic acids were released from the mucin by mild acid hydrolysis and prefractionated on a Dowex 2X8 anion-exchange column (formate form) by elution with a 0-0.6 M gradient of formic acid. The four pools of sialic acids obtained in this way were each further fractionated by column chromatography on cellulose with n-butanol/n-propanol/water (1/2/1, v/v/v) as eluent. By this procedure, N-acetylneuraminic acid, N-acetyl-7-O-acetylneuraminic acid, N-acetyl-9-O-acetylneuraminic acid, N-glycoloylneuraminic acid, and N-glycoloyl-9-O-acetylneuraminic acid were obtained in pure form. The other sialic acids could be enriched sufficiently in different fractions for structural identification. Analyses of sialic acids were carried out by one-dimensional and two-dimensional thin-layer chromatography, gas-liquid chromatography, and gas-liquid chromatography-mass spectrometry.

Animals↗
PubMed1983

Cytogenetic analysis of variegation suppressors and a dominant temperature-sensitive lethal in region 23-26 of chromosome 2L in Drosophila melanogaster.

Three suppressor loci for position-effect variegation, one dominant temperature-sensitive (DTS), three Minute genes, and two recessive visible mutants (ed, tkv) have been cytogenetically localized by using duplications and deficiencies in regions 23-25 of chromosome arm 2L of Drosophila melanogaster. Two of the suppressor loci studied proved to represent haplo-abnormal genes localized in regions 23A6-23F6 and 24E2-25A1, respectively. The third one is a strong triplo-abnormal suppressor mapping in 25F4-26B9 which affects white variegation in wm4h when present in three doses. The l(2)2DTS mutation, which belongs to a group of noncomplementing dominant temperature-sensitive mutations, is localized in the 25A4-B1 region. Furthermore, two Minute genes have been localized in region 24 that are included in Df(2L)M11 and can be separated employing translocation (Y;2)P8 (24E2-4): M(2)LS2 in 24D3-4-24E2-4, and M(2)z in 24E4-5-24F5-7. A third Minute gene (M(2)S1) is localized in 25C3-8-25C9-D1. The usefulness of the isolated chromosomal rearrangements for further genetic studies of region 23-26 is discussed.

Animals↗
PubMed1983

Mannan structure analysis of the fragile Saccharomyces cerevisiae mutant VY1160.

The fragile Saccharomyces cerevisiae mutant VY1160 has a cell-wall mannan with a lower molecular weight and a higher nitrogen content than the parental S288C strain. More mannobiose but less mannotriose and mannotetraose were found in O-glycosidically-bound oligosaccharides in the mutant. Acetolysis analysis of the alkali-stable mannan also showed a reduction of mannotetraose and an increase of the mannobiose fractions. Methylation analysis of total mannan, or side chains recovered after acetolysis, showed that in the mutant the amount of alpha(1-3)-linked mannose units prevailed over alpha(1-2)-linked residues.

Carbohydrate Conformation↗
PubMed1983

The occurrence of N-acetyl- and N-glycoloylneuraminic acid in Trypanosoma cruzi.

Different strain of Trypanosoma cruzi were analysed to have 65--105 micrograms of sialic acids per 10(10) cells. By thin-layer chromatography, and in part by gas liquid chromatography and gas-liquid chromatography-mass spectrometry, all strains were found to contain N-acetyl- and N-glycoloylneuraminic acid in various ratios. After incubation of the parasites with either [3H]acetate or N-acetyl-[3H]mannosamine, no radioactivity was found in the sialic acids, thus leading to the suggestion that the parasites are unable to synthesize sialic acids from their precursors.

Animals↗
PubMed1982

[Mannan localization with concanavalin A in conjunction with electron microscopy and chemical analysis of differently prepared cell walls of the food protein yeast Candida spec. H].

Regions of different electron densities after concanavalin A-peroxidase-reaction have been observed in cell walls of intact cells as well as in isolated cell walls: In the peripheral region of intact cell walls two mannan layers appear. Treating isolated cell wall with pronase, NaOH, ethylendiamine or citrate buffer, respectively, we find on A binding spots in the inner cell wall regions which appear electron transparent in the untreated cell walls. Apparently the mannan component of the inner cell wall regions is masked by proteins. In correspondence with chemical analysis our results cannot confirm the existence of inner cell wall regions which are free of mannan.

Candida↗
PubMed1982

[Polysaccharide structure of cell wall preparations from the food protein yeast Candida spec. H].

More than 27% of the cell wall are unstably bound components: Proteophosphomannan as a main polysaccharide of the cell wall, mannose and manno-oligosides which are bound to peptides or phosphate. 19% are glycosidically linked with a phosphate bridge or O-glycosidically (Ser/Thr) linked with the protein which is covalently bound to the cell wall. Besides mannose and glucose, manno-oligosides and gluco-oligosides are involved in this linkage. A preparation consisting of glucan and chitin remains after careful degradation. It contains (1,2)-, (1,3)- and (1,6)- linked glucose, (1, 2, 3)-, (1, 2, 6)- or (1, 3, 6)-glucose-branchpoints and (1,4)-linked N-acetylglucosamine.

Candida↗
PubMed1982

[In vitro incorporation of 14C-hexose-6-phosphate in mannan, beta-glucan and glycogen in Candida spec. H and its mutants].

Mannose-6-p is an activator of the 14C-mannose incorporation from GDP-14C-mannose in the mono- and oligosaccharides and in the mannopolymers of the cell wall proteophosphomannan produced by the food protein yeast Candida spec. H. Moreover, mannose-6-p is a precursor of proteophosphomannan: 14C-Mannose-6-p has been incorporated in absence of GTP. Corresponding behaviour shows glucose-6-p by synthesis of beta-glucan and glycogen. Mutants of Candida spec. H with different efficiency in the biosynthesis of mannan, beta-glucan and glycogen incorporate hexose-6-p in a different extent.

Candida↗
PubMed1982

Mutants affecting position-effect heterochromatinization in Drosophila melanogaster.

The dominant suppressor Su(var)b101 and the dominant enhancer En(var)c101 were found to affect significantly white variegation in a strongly variegating line of the Wm4 chromosome (Wm4h) which has been used as standard rearrangement for a genetic dissection of position-effect variegation (Reuter and Wolff, 1981). Both mutations were also shown to affect position-effect heterochromatisation in T (1 ; 4)Wm258-21 and variegation in all the rearrangements tested (white, brown, scute and bobbed variegation). These results suggest that the genes identified encode functions essential for the manifestation of gene inactivation in position-effect rearrangements. It seems also reasonable to assume that in all the rearrangements tested identical heterochromatisation processes lead to inactivation of the genes whose phenotype is variegated.

Animals↗
PubMed1982

Butyrate sensitive suppressor of position-effect variegation mutations in Drosophila melanogaster.

Mutations at a locus on chromosome II of D. melanogaster suppressing position-effect variegation mutations have been identified which display recessive butyrate sensitivity. Survival of homozygous mutant flies is significantly reduced on medium containing sodium n-butyrate. The butyrate sensitive suppressor mutations are further characterized by recessive female sterility and reduced survival of homozygotes. Complementation analysis showed their allelism. The locus of these mutations, Su-var (2) 1, has been localized to 40.5 +/- 0.2 and, by using interstitial duplications, to region 31CD on the cytogenetic map. Moreover, the mutant alleles of the Su-var (2) 1 locus display a lethal interaction with the heterochromatic Y chromosome. The presence or absence of a Y chromosome in males or females has a strong influence on the viability of homozygous or transheterozygous suppressor flies. All the genetic properties of Su-var (2) 1 mutants suggest strongly that this locus affects chromosome condensation.

Animals↗