Carbohydrate intolerance after acute gastroenteritis--a disappearing problem in Polish children.

The prevalence of carbohydrate intolerance in Polish children during an acute episode of gastroenteritis was determined. One hundred and seven consecutive children, less than 3 years old, with acute diarrhoea were enrolled into the study. Carbohydrate intolerance (diagnostic criteria: >0.5% reducing substances and stool pH less than 5.5) was diagnosed in 14/107 (13.08%) children: lactose intolerance was present in 12 (11.2%) patients; glucose polymer intolerance in 1 (0.93%) and monosaccharide intolerance in 1 (0.93%). The most important predisposing factor was rotavirus. In all cases the carbohydrate intolerance was transient, resolving within 5 days. Carbohydrate intolerance is also an infrequent problem in Polish children. Restriction of lactose-containing foods (use of lactose-free or low lactose formulas) for the majority of children with gastroenteritis does not seem to be justified.

Ganglioside binding proteins of calf brain with ubiquitin-like N-terminals.

Two ganglioside-associated protein components I and II have been isolated from crude ganglioside preparations of calf brain by DEAE-Sephadex ion-exchange chromatography. Both components exhibited binding capacity in aqueous media for gangliosides of the 'ganglio' series but not for neutral glycosphingolipids (polyglycosylceramides) and only a low capacity for sialosylparagloboside. Each protein bound individual gangliosides with different efficiency. Upon prolonged incubation of component I with gangliosides, complexes with high (30:1) and low (6:1) glycolipid/protein molar ratios were formed. The latter but not the former complex was able to penetrate Sephadex G-200 beads. Both components inhibited plating efficiency of cultured mouse N2a neuroblastoma cells. The molecular masses of components I and II were determined by SDS/PAGE to be 11-12 kDa and 28 kDa, respectively. Carbohydrates (fucose, mannose, galactose, N-acetylglucosamine, N-acetylgalactosamine, and some sialic acid) were found only in component II. When examined by reverse-phase HPLC each component separated into two major closely migrating peaks which were subsequently examined by Edman degradation. Amino acid sequences of the N-terminal portions of three of these peaks (one peak from component I and both peaks from component II) showed, as far as the sequences were established, identity with the sequence of ubiquitin. It is hypothesized that the proteins may be instrumental in intracellular trafficking of gangliosides.

Characterization and quantitation of fatty acids covalently bound to erythrocyte membrane proteins: anion transporter contains 1 mol of fatty acid thiol ester.

Human erythrocyte membranes which had been thoroughly extracted with organic solvents contained 20 nmol of fatty acids/mg dry wt. The major fatty acids were palmitic and stearic with their monoethenoic derivatives as minor constituents. No other fatty acids were detected. When solvent-extracted membranes were digested with Pronase about 90% of the original content of fatty acids was retained in the insoluble residue. Fatty acids were linked to membrane proteins through alkali-labile bonds of which 30% were of a thiol ester and the remainder of an O-ester type. This conclusion is based on differential liberation of fatty acids by hydroxylamine at pH 7.0 and pH 11.0. Two extracts of membranes enriched in peripheral proteins (bands 1, 2, 5 and 2.1, 4.1, 4.2, 6) were prepared and extracted with organic solvents but each contained about six times less fatty acids than the parent solvent-extracted membranes. Glycophorin A contains little if any covalently bound fatty acids. Anion transporter (band 3) contains about 1 mol of thiol ester of fatty acid. This accounts for about half of the thiol ester-linked fatty acids in the parent solvent-extracted membranes. Most of the O-ester-linked fatty acids are linked to an undisclosed membrane protein.

Human platelets release alpha-6-L-fucosyltransferase upon activation.

Previously we have shown that human platelets release alpha-6-L-fucosyltransferase (EC 2.4.1.68) during coagulation of blood [(1987) Glycoconjugate J. 4, 43-49]. Here we report that agonists which induce platelet aggregation bring about release of the enzyme. In quantitative terms the release of alpha-6-L-fucosyltransferase by washed, aggregated platelets was very similar to that occurring during blood coagulation.

A novel form of GD1c ganglioside IV3 (NeuAc alpha 2-8 NeuGc)Gg4Cer from murine X-ray induced thymoma.

Four disialoganglioside fractions were isolated from X-ray induced thymoma in C57Bl/6 mice. On the basis of compositional and methylation analyses as well as degradation with specific exoglycosidases a novel form of GD1c ganglioside NeuAc alpha 2-8 NeuGc alpha 2-3 Gal beta 1-3 GalNAc beta 1-4 Gal beta 1-4 GlcCer was identified.