[Evaluation of selective plating media for the detection of heat- or freeze-injured Staphylococcus aureus].

The efficacy of Baird-Parker (BP) agar, mannitol-salt-egg yolk (MSEY) agar and mannitol salt (MS) agar in detecting Staphylococcus aureus FRI-100 heated at 52 degrees C for 20 min in 100 mmol/L potassium phosphate buffer was determined. Brain heart infusion agar with 1% pyruvate (BHIP agar) supported the highest recovery of injured cells and was used as the control medium. Of the three selective media, significantly higher recovery of heat-injured cells was observed on BP agar than MSEY agar, and the poorest recovery was observed on MS agar (p < 0.05). Low recovery of unheated cells was obtained for MS compared with other media (p < 0.05). A reduction in populations occurred gradually in reagent-grade water stored for 14 days at -20 degrees C. There was no significant difference between BHIP agar and MS agar in the number of freeze-injured cells recovered from 1 to 14 days.

Cholesteryl glucoside-induced protection against gastric ulcer.

The cytoprotective effect of heat shock proteins (HSPs) promises new therapeutic modalities for medical treatment. We examined the anti-ulcer effect of cholesteryl glucoside (1-O-cholesteryl-beta-D-glucopyranoside, CG) on cold-restraint stress-induced gastric ulcer in rats, in terms of its correlative ability to activate heat shock factor (HSF) and to induce HSP70. Rapid induction of CG occurred in animal tissues, especially in stomach, after exposure to stress, indicating that this glycolipid might act as an anti-stress, lipid mediator involved in the very early stages of stress-induced signal transduction. Orally administered CG apparently showed anti-ulcer activity in rats via HSF activation and HSP70 induction. When compared with geranylgeranylacetone (GGA), the well known as an effective, synthetic anti-ulcer agent, CG proved to have the same level of strength on ulcer inhibition. GGA caused CG and HSP70 induction in gastric mucosa, indicating that GGA induced HSP70 via CG production. CG thus might be useful for medical treatment of stress-induced diseases, and as an anti-stress supplement for daily diet.