Baker's yeast (Saccharomyces cerevisiae) antigen in obese and normal weight subjects.

Baker's yeast (Saccharomyces cerevisiae) and its cell wall components have been used as one of the alternatives to antibiotic growth promoters in the feed industry. Antibodies to cell wall mannan of this yeast (ASCA) have been traditionally used in the study of Crohn's disease (CD). We applied ASCA in relation to obesity. This study aims (i) to determine the concentration of ASCA (immunoglobulin A [IgA] and immunoglobulin G [IgG]) in obese compared with normal weight individuals and (ii) to determine if there is a correlation between ASCA concentrations, obesity indices and C-reactive protein. Forty obese individuals (body mass index [BMI] > 35 kg m(-2) ) and 18 healthy (BMI < 25 kg m(-2) ) volunteers participated in this case-control study. Binding activity of serum IgA and IgG to the cell wall mannan of S. cerevisiae was measured by enzyme-linked immunosorbent assay. More than one-third of the obese individual (35%) showed elevated titres of ASCA compared with the control group (5%). This antibody was positively associated with weight (P = 0.01), BMI (P = 0.02) and waist circumference (P = 0.02), but not with C-reactive protein. It seems that ASCA are not only specific for CD but are also associated with obesity. S. cerevisiae or a related antigen may play a role in the matrix of this complex condition.

The Genetic Structure of Field Populations of Rhynchosporium secalis from Three Continents Suggests Moderate Gene Flow and Regular Recombination.

ABSTRACT Restriction fragment length polymorphism (RFLP) markers were used to compare the genetic structure of field populations of Rhynchosporium secalis from barley. A total of 543 isolates representing 8 field populations were sampled from Australia, California, Finland, and Norway. Gene and genotype diversity were high in all populations. Nei's average gene diversity across seven RFLP loci was 0.513. Hierarchical gene diversity analysis showed that 9% of the total genetic variability was distributed among continents, 4% was distributed among fields within continents, and 13% was distributed among collection stations within a field. The majority (74%) of genetic variability was distributed within collection areas of approximately 1 m(2) within fields. Gene flow appears to be significant on a regional scale but more restricted among continents. Allele frequencies were significantly different at several RFLP loci. Genetic distances were small among populations within regions and large between regions. Pairwise comparisons of genotype diversity in the populations revealed significant differences among populations that were related mainly to differences in sampling strategies. Isolates from Norway and Finland showed a lower copy hybridization pattern with probe pRS26. This probe functioned as a fingerprint probe for the California and Australian isolates. Seven out of the eight populations studied were at gametic equilibrium for RFLP loci, suggesting that R. secalis populations in Norway, Finland, and Australia undergo regular recombination, although a teleomorph has not yet been recognized.