Overexpression of Cicer arietinum βIII-Gal but not βIV-Gal in arabidopsis causes a reduction of cell wall β-(1,4)-galactan compensated by an increase in homogalacturonan.

In Cicer arietinum, as in several plant species, the β-galactosidases are encoded by multigene families, although the role of the different proteins is not completely elucidated. Here, we focus in 2 members of this family, βIII-Gal and βIV-Gal, with high degree of amino acid sequence identity (81%), but involved in different developmental processes according to previous studies. Our objective is to deepen in the function of these proteins by establishing their substrate specificity and the possible alterations caused in the cell wall polysaccharides when they are overproduced in Arabidopsis thaliana by constructing the 35S::βIII-Gal and 35S::βIV-Gal transgenic plants.

Effect of simulated gastrointestinal digestion on sialic acid and gangliosides present in human milk and infant formulas.

The effects of simulated gastrointestinal digestion upon sialic acid and gangliosides in infant and follow-on formulas and human milk, as well as their bioaccessibility, have been evaluated. The gastric stage is the step that causes a greater decrease in sialic acid and ganglioside contents. The intestinal stage only decreases the total and individual contents of gangliosides.

Neutral glycosphingolipid content of ovine milk.

Milk glycosphingolipids (GSL) have been reported to participate in the newborn's defense against pathogens. Taking this into account, in this study we determined the neutral GSL content of ovine milk, including its fatty acid profile. Its role in bacterial adhesion was also addressed by immunodetection of separate GSL in a high-performance thin-layer chromatography overlay assay.

Glycosphingolipids from bovine milk and milk fat globule membranes: a comparative study. Adhesion to enterotoxigenic Escherichia coli strains.

Several components of milk fat globule membranes (MFGMs) have been reported to display beneficial health properties and some of them have been implicated in the defense of newborns against pathogens. These observations prompted us to determine the glycosphingolipid content of MFGMs and their interaction with pathogens. A comparative study with whole milk components was also carried out.

Distribution of sialic acids in the milk of spanish mothers of full term infants during lactation.

Objectives: The protective effect of human milk against infection is well known. Several non-immunologic components, including complex carbohydrates, have been described. The present study was undertaken to determine the sialic acid distribution in different milk fractions (complex carbohydrates).

Lactational changes in the fatty acid composition of human milk gangliosides.

The objectives of this work were to study the FA composition of milk gangliosides, as well as to gain further insight into the characterization of human milk gangliosides. The potential capacity of human milk gangliosides to adhere to human enterotoxigenic Escherichia coli (ETEC-strains) was also studied. Human milk gangliosides were isolated and identified by high-performance TLC or immunoassay.

Enterotoxigenic Escherichia coli strains bind bovine milk gangliosides in a ceramide-dependent process.

Diarrhea caused by enterotoxigenic Escherichia coli (ETEC) is the main infectious disease of newborn calves. The first step of infection involves bacterial attachment to the intestinal mucosa. This adhesion is mediated by fimbriae that recognize some glycoconjugates on the host cell surface, in particular, several gangliosides.

Binding of milk oligosaccharides by several enterotoxigenic Escherichia coli strains isolated from calves.

Milk oligosaccharides have been proposed to play an important role in newborn defense, blocking bacterial adhesion to the intestinal mucosa and preventing infections. Some studies have been performed on human milk oligosaccharides. Here we checked whether bovine milk oligosaccharides would achieve the same protective action against the most common calf enteric pathogens.

Sialyloligosaccharides in human and bovine milk and in infant formulas: variations with the progression of lactation.

Several lines of research support a role for human milk oligosaccharides in the defense of breast-fed infants against pathogens. Some ofthese oligosaccharides contain at least one moiety of sialic acid and are, thus, termed sialyloligosaccharides. These constitute a significant component (>1 g/L) of human milk.

The sialylated fraction of milk oligosaccharides is partially responsible for binding to enterotoxigenic and uropathogenic Escherichia coli human strains.

Milk oligosaccharides can act as soluble receptors that block bacterial adhesion to the different epithelia. Colonization factor antigens (CFA)/I- and CFA/II-expressing enterotoxigenic Escherichia coli (ETEC) strains constitute one of the main causes of diarrhea in infants. Here, the inhibition of hemagglutination mediated by these strains by milk oligosaccharides was tested.

Distribution of bovine milk sialoglycoconjugates during lactation.

The sialoglycoconjugate content of human milk has been extensively studied. However, little attention has been paid to the changes occurring in these compounds in bovine milk during lactation. Since sialoglycoconjugates are very abundant in milk from the early stages of lactation, they have been suggested to be important for the nutrition of the newborn during the first months of life.

Bovine milk gangliosides: changes in ceramide moiety with stage of lactation.

The stage of lactation is one of the most important factors that influence milk composition. Changes in fatty acids from triacylglycerols and phospholipids have already been reported. In this study, we looked for a lactational change in the ganglioside lipid moiety since ganglioside contents and patterns vary strongly with stage of lactation.

Single-step gas chromatography-mass spectrometry analysis of glycolipid constituents as heptafluorobutyrate derivatives with a special reference to the lipid portion.

In a previous work (Zanetta et al. Glycobiology 9, 255-266 (1999)), it was reported that all constituents of gangliosides could be obtained as heptafluorobutyrate derivatives after methanolysis in a single gas chromatography analysis. This report demonstrates that gas chromatography coupled with mass spectrometry in the electron impact mode allows identification and quantification of long-chain bases and fatty acids without interference from monosaccharides.

Changes of acetylcholinesterase activity in brain areas and liver of sucrose- and ethanol-fed rats.

The effects of chronic ethanol or sucrose administration to rats on acetylcholinesterase from brain and liver were investigated. Membrane-bound and soluble acetylcholinesterase activities were determined in fractions prepared by centrifugation. The thermal stability and the effects of temperature and different types of alcohols on acetylcholinesterase activity were also studied.

Developmental changes in UDP-N-acetylglucosamine 2-epimerase activity of rat and guinea-pig liver.

The activity of UDP-N-acetylglucosamine 2-epimerase was determined in the liver of rats and guinea-pigs of different ages. The activity of this enzyme in rats was low at birth, increased to a maximum value on day 15, and fell gradually until day 30. Thereafter, it increased up to the 60th day.

A critical analysis of total sialic acid and sialoglycoconjugate contents of bovine milk-based infant formulas.

Background: Several infant formulas were bovine milk-based products. Mature bovine milk has a very low sialoglycoconjugate content compared with human milk from the first phases of lactation.

Methods: The present study was undertaken to determine total sialic acid and oligosaccharide, glycoprotein, and ganglioside sialic acid contents of bovine milk-based formulas.

New data on content and distribution of gangliosides in human milk.

The content and distribution of gangliosides, and total lipid content, were studied in human milk samples from different periods of lactation. We found a significant correlation (r = 0.5564; p = 0.

Cocaine exposure induces changes in the ganglioside content of rat liver.

During cocaine exposure, the liver undergoes significant morphological and biochemical changes. We report here changes in the ganglioside pattern of rat liver after repeated administration (over 5 hours, one injection per hour) of a moderate dose of cocaine (10 mg/kg body weight). Cocaine exposure results in an accumulation of more complex gangliosides (GM1, GD1a, GD1b, GT1b and GQ1b) and a reduction of precursors (GM3, GM2, GD3 and GD2).

Changes in ganglioside and sialic acid contents of goat milk during lactation.

The ganglioside content of goat milk has been determined from d 1 after parturition to d 60 of lactation. Marked changes occurred in milk over the course of lactation; the highest ganglioside content occurred in d-1 colostrum and then decreased to the end of the period studied. At least seven different ganglioside species were detected; three gangliosides containing sialyllactosylceramide accounted for 66 to 92% of the total lipid-bound sialic acid; this result reflected a very simple core structure of goat milk gangliosides.

Ganglioside content of rat liver after administration of ethanol and pentazocine or sucrose supplemented diets.

In a previous paper, we determined the effect of either ethanol or pentazocine administered separately on the ganglioside content of rat liver. In the present paper we have investigated the effect of pentazocine injection on the liver ganglioside contents of chronic alcoholic rats. The effect of high carbohydrate ingestion was also studied.

Lactational changes in the N-glycoloylneuraminic acid content of bovine milk gangliosides.

The N-glycoloylneuraminic acid (Neu5Gc) contents of milk and milk gangliosides from bovines were investigated during the different stages of lactation. The Neu5Gc content of milk is high in the colostrum (32% of the total sialic acid content of milk) and decreases thereafter until the end of the period considered (6% on day 30). When the Neu5Gc content of gangliosides was evaluated a similar profile to that of Neu5Gc in total sialic acids was found.

Gangliosides in bovine milk. Changes in content and distribution of individual ganglioside levels during lactation.

Bovine milk undergoes changes in its ganglioside contents during the different stages of lactation. These contents are higher in colostrum (7.5 mg of lipid-bound NeuAc/kg) than in transitional (2.

Ganglioside and phospholipid composition of forebrain, cerebellum, and brain stem from adult and newborn rats.

The aim of this study was to elucidate whether sex or pregnancy state might affect the content and/or pattern of gangliosides from the forebrain, cerebellum and brain stem of rats. Adult male, mother (1-day after offspring) and nonpregnant rats of similar age were analyzed. Non-significant differences in ganglioside concentrations and patterns were found for the respective neural area of adult male and female rats except for a decrease in cerebellum and brain stem content from mothers and 12.

Lectin-resistant variants of mouse Lewis lung carcinoma cells. II. Altered glycosylation of membrane glycoproteins.

Lectin-resistant variants of mouse Lewis lung carcinoma LL2 cell line, selected with wheat germ agglutinin (WGAR), Ricinus communis agglutinin II (RCA IIR) and Aleuria aurantia agglutinin (AAAR) were studied. Total cellular glycopeptides of the parent LL2 line and of the five lectin-resistant variants were analyzed by gel filtration and affinity chromatography on immobilized concanavalin A and Lens culinaris agglutinin. The results revealed that low-metastatic WGAR and RCA IIR variants possessed less highly branched tri- and tetra-antennary N-acetyllactosaminic type glycans with a simultaneous increase in biantennary N-acetyllactosaminic type, oligomannosidic type or hybrid type glycans, as compared to the parent metastasizing LL2 cell line.