Glycoprofile of the different cell types present in the mucosa of the horse guttural pouches.

Histochemical characterization of the equine guttural pouches was performed using lectins combined with sialidase digestion and deglycosylation pre-treatments. The goblet cells contained O- and N-linked oligosaccharides with alpha-Fuc, GlcNAc moieties whereas beta-GalNAc, beta-Gal-(1-3)-GalNAc, beta-Gal-(1-4)-GlcNAc and alpha-Gal residues belonged only to O-linked glycoproteins. The acinar and ductal cells expressed alpha-Man/alpha-Glc in N-linked oligosaccharides, GlcNAc in both O- and N-glycoproteins and beta-GalNAc, beta-Gal-(1-3)-GalNAc, beta-Gal-(1-4)-GlcNAc and alpha-Gal residues included in O-linked glycoproteins. The Golgi area of the epithelial lining expressed alpha-Fuc in O-linked glycoproteins, internal GlcNAc in N-linked glycoproteins and large amounts of sialic acid residues linked to subterminal beta-GalNAc, Galbeta1,4GlcNAc and Galbeta1,3GalNAc. High amounts of sulpho-carbohydrates and of sialic acids (alpha2,3-6), linked to-alpha/beta-Gal and sialic acids (alpha2-6) linked to beta-GalNAc, were also demonstrated. Such diversity of the mucin saccharide residues may be implicated in the binding of macromolecules such as those of bacterial or viral etiology, thus playing a role in the organism's host-defense mechanism in the guttural pouches.

Clinical, serological and molecular investigations of EHV-1 and EHV-4 in 15 unweaned thoroughbred foals.

Fifteen unweaned thoroughbred foals, born on a stud farm to vaccinated mares, were clinically monitored during their first six months of life and repeatedly tested for equine herpesvirus type 1 (EHV-1) and equine herpesvirus type 4 (EHV-4). Nasopharyngeal swabs and blood samples were collected and screened respectively by PCR and seroneutralisation to detect the presence of the virus, explore its role as a possible cause of respiratory disease, and to assess the efficiency of the pcr for the diagnosis of this disease. The foals were divided into three groups on the basis of their clinical signs and whether they had seroconverted to EHV-1 and/or EHV-4: first, foals with no clinical signs of disease that had not seroconverted; secondly, foals with clinical signs that had seroconverted, and thirdly, foals with clinical signs that had not seroconverted. The results indicated that the viruses circulated on the stud farm despite stringent vaccination regimens against them, and confirmed their association with respiratory disease. The absence of significantly different pcr results among the three groups of foals showed that the pcr was effective in confirming the circulation of the viruses on the premises without being particularly helpful as a diagnostic tool.