Glucose toxicity effect and accumulation of methylglyoxal by the periodontal anaerobe Bacteroides forsythus.

Growth of the periodontal pathogen Bacteroides forsythus in broth cultures showed inhibition in the presence of 10mM glucose added to the medium. Glucose inhibition in a number of rumen bacteria has been attributed to the accumulation of methylglyoxal (MG), a highly reactive electrophile known to exhibit cytotoxic effects. HPLC analysis revealed elevated concentrations of MG in cultures of seven strains of B.

Maintenance of DeltapH by a butanol-tolerant mutant of Clostridium beijerinckii.

The isolation of Clostridium beijerinckii mutants that are more tolerant of butanol than the wild-type offered the opportunity to investigate whether the membrane activities which are required for maintaining the transmembrane DeltapH (the difference in pH between the cellular interior and exterior) are sensitive targets of butanol toxicity. The DeltapH was measured by the accumulation of [14C]benzoate using late-exponential-phase cells which were suspended in citrate/phosphate buffer at pH 5 (to maximize the DeltapH component of the protonmotive force) and supplemented with glucose and Mg2+. The DeltapH of the butanol-tolerant tolerant mutant, strain BR54, of C.

Accumulation of methylglyoxal in the gingival crevicular fluid of chronic periodontitis patients.

Background, Aims: Methylglyoxal (MG), a toxic product of cellular metabolism, is elevated in tissues and fluids in a number of human diseases. A cross-sectional study was undertaken to determine whether MG accumulates in the gingival crevicular fluid (GCF) of chronic periodontitis patients.

Methods: GCF samples were collected for 30 s each from three teeth with pocket depths greater than 3 mm (DD sites), from 14 chronic periodontitis patients.

Evidence for the early onset of gingival inflammation following short-term plaque accumulation.

Aim: A study was undertaken to examine cytokine markers in gingival crevicular fluid (GCF) during the early stages of plaque accumulation.

Methods: A panel of five subjects with good oral hygiene went without brushing for 1 or 3 days, after which GCF samples were taken by placing paper strips into the gingival margins of the maxillary premolars and first molar for 30 s. GCF flow rates were determined with a Periotron instrument (Oraflow, Inc.

Cheese consumption and the development and progression of dental caries.

Whereas research into the causes of dental decay has focused on the harmful relationship between dental plaque bacteria and foods, studies into the protective effects of foods have been infrequent and limited in number. Recent investigations showed that milk and cheese could reduce the effects of metabolic acids, and could help restore the enamel that is lost during eating. Postulated mechanisms involve buffering, salivary stimulation, reduction of bacterial adhesion, reduction of enamel demineralization, and/or promotion of remineralization by casein and ionizable Ca and P.