Effect of Bifidobacterium bifidum DSM 20082 cytoplasmic fraction on human immune cells.

The objective of the present study was to determine the effect of the soluble cytoplasmic fraction from Bifidobacterium bifidum DSM 20082 (Bb) lysate on peripheral blood T cells. In peripheral blood mononuclear cells of healthy subjects, cytotoxic activity, proliferation, apoptosis, and up-regulation of CD8 or CD4 molecules in T cells were examined. When peripheral blood mononuclear cells were stimulated with Bb lysate, the main effect was observed in CD8+ cells as a significant increase of CD8 molecules in a dose-dependent manner, and this behavior was observed at 24, 48, and 72 h after stimulation; in contrast, stimulation with Bb lysate showed no effect on the up-regulation of CD4 molecules in T helper cells.

Characterisation of glutamine fructose-6-phosphate amidotransferase (EC 2.6.1.16) and N-acetylglucosamine metabolism in Bifidobacterium.

Bifidobacterium bifidum, in contrast to other bifidobacterial species, is auxotrophic for N-acetylglucosamine. Growth experiments revealed assimilation of radiolabelled N-acetylglucosamine in bacterial cell walls and in acetate, an end-product of central metabolism via the bifidobacterial D: -fructose-6-phosphate shunt. While supplementation with fructose led to reduced N-acetylglucosamine assimilation via the D: -fructose-6-phosphate shunt, no significant difference was observed in levels of radiolabelled N-acetylglucosamine incorporated into cell walls.

Lectin from Phaseolus acutifolius var. escumite: chemical characterization, sugar specificity, and effect on human T-lymphocytes.

Purification of the lectin from Phaseolus acutifolius var. escumite was achieved by affinity chromatography on a column containing glutaraldehyzed membranes from blood group O erythrocytes. The lectin is a tetrameric glycoprotein of 121 kDa with 10% of sugar by weight composed by four subunits of 30 kDa as determined by SDS-PAGE.

Isolation and characterization of the potential receptor for wheat germ agglutinin from human neutrophils.

Neutrophils participate in host protection and central to this process is the regulation of oxidative mechanisms. We purified by affinity chromatography the receptor for the GlcNAc-specific WGA from CD14+ CD16+ cell lysates (WGAr). The receptor is a 141 kDa glycoprotein constituted by two subunits of 78 and 63 kDa.

The effect of sugars and free amino acids from the freshwater prawn Macrobrachium rosenbergii hemolymph on lectin activity and on oxidative burst.

We determined the effect of low molecular weight components (LMWC) from healthy juvenile and adult Macrobrachium rosenbergii hemolymph on lectin activity and oxidative burst (OB) in hemocytes. In an attempt to identify the LMWC that affect the lectin's hemagglutinating activity or oxidative burst, we determined the hemolymph carbohydrates and free amino acids (FAA) concentration. The LMWC (<2000 Da) were obtained after dialysis of the hemolymph.

Isolation of the receptor for the Amaranthus leucocarpus lectin from human T lymphocytes.

Amaranthus leucocarpus lectin (ALL) is specific for GalNAc, and recognizes human T cells. The receptor for ALL was purified from T cells using biotin-labeled lectin and avidin-agarose as affinity matrix. It is a 70-kDa glycoprotein, constituted mainly by serine, glycine, and glutamic acid; its glycosidic portion contains mainly GalNAc; galactose, sialic acid, mannose, and GlcNAc were identified at a lower proportion.

Bifidobacterium longum requires a fructokinase (Frk; ATP:D-fructose 6-phosphotransferase, EC 2.7.1.4) for fructose catabolism.

Although the ability of Bifidobacterium spp. to grow on fructose as a unique carbon source has been demonstrated, the enzyme(s) needed to incorporate fructose into a catabolic pathway has hitherto not been defined. This work demonstrates that intracellular fructose is metabolized via the fructose-6-P phosphoketolase pathway and suggests that a fructokinase (Frk; EC 2.

Amino acid decarboxylase activity and other chemical characteristics as related to freshness loss in iced cod (Gadus morhua).

Biogenic amine levels and other biochemical indicators were measured to study the safety of and the loss of freshness in iced Atlantic cod. Biogenic amine content exhibited high variability during iced storage of Atlantic cod. Ornithine and lysine decarboxylase activity apparently increased at the end of the storage period.