Estrogen effects on Candida albicans: a potential virulence-regulating mechanism.

Three Candida albicans strains were tested in the presence of 17-beta-estradiol (10-6 M and 10-9 M) for increased growth and for enhanced survival during incubation at nonpermissive temperatures. All 3 test organisms showed increased growth in the presence of estradiol compared with estrogen-free controls. Likewise, all 3 strains, when treated with estradiol, survived incubation at 48 degrees C better than did controls. Cytoplasmic extracts were probed with an anti-hsp90 antibody, and results suggested that intracellular hsp90 was up-regulated in the presence of 10-9 M 17-beta-estradiol. The results were confirmed by reverse-transcriptase polymerase chain reaction with primers specific for C. albicans hsp90. A kinetic study revealed that peak hsp90 expression occurred within 2 h of exposure to 17-beta-estradiol. In addition, estrogen increased the amount of cdr1 (Candida multidrug resistance) mRNA compared with cells not treated with estrogen. Coumarin and phenol also up-regulated hsp90 and cdr1 mRNAs, indicating that the estrogen-sensing and -response systems in C. albicans may lack specificity.

The effect of peritoneal contamination on wound strength of small bowel and colonic anastomoses.

Primary bowel repair in the face of peritoneal soilage is still a controversial area. Previous studies using the rat model have demonstrated a difference in new collagen synthesis after 24 hours of peritoneal contamination. Currently, the effect of short-term fecal contamination of the peritoneal cavity on anastomotic healing and strength is not known. This study was designed to evaluate anastomotic wound strength in the face of fecal contamination during this time period. Twenty Sprague Dawley rats were randomized into two groups: twelve-hour control (n = 10) and 12-hour cecal ligation and puncture (CLP; n = 10). Both groups underwent laparotomy with either CLP (12-hour) or cecal manipulation (12-hour control). Animals were allowed to recover for 12 hours, according to their assigned groups. A second laparotomy was subsequently performed in which the CLP groups had partial cecectomy to remove the source of contamination, followed by mid-jejunal and colonic division with associated primary anastomosis. Control groups had a similar procedure without partial cecectomy. All abdomens were irrigated, and all animals received immediate postoperative antibiotics and an initial fluid bolus. Animals were recovered and received 3 days of postoperative antibiotics. On postoperative day 4, animals were sacrificed and anastomotic sites were resected. Specimens were then placed in a tensiometer and disrupted under dynamic stress. Peak load was recorded for each, and maximum standard load was calculated. Hydroxyproline content of each segment was also determined after disruption. CLP values were compared with control values using unpaired Student's t test. Statistical significance threshold was P < 0.5. There was no significant difference in maximum anastomotic wound strength or hydroxyproline content between 12-hour CLP and 12-hour control group for both small bowel and colon anastomoses. Short-term peritoneal soilage (12-hour) does not significantly effect the maximum tensile strength or hydroxyproline content of primary small bowel or colonic anastomoses in this model. This study suggests that short-term fecal contamination of the peritoneal cavity may not be a contraindication to primary bowel anastomosis.

Isolation and identification of a 92-kDa stress induced protein from Candida albicans.

It was previously shown that the presence of estrogen enhances survival of Candida albicans under heat and oxidative stresses. A 92-kDa protein is inducible by heat shock and estrogen in C. albicans. Previous studies have described this protein as hsp90 because of its molecular size and heat inducibility as seen on electrophoretic gels and Western blots. In this study, ion exchange, hydroxyapatite and size exclusion chromatography were used to isolate a 92-kDa-protein band. The N-terminal sequence of isolated protein blotted onto a PVDF membrane was determined to be V-Q-S-?-V-L-G-F-P-R. This sequence is homologous to the N-terminal sequence of the MET6 gene product, cobalamin-independent methionine synthase, from Saccharomyces cerevisiae. The results of this study suggest that a cobalamin-independent methionine synthase homolog is inducible by heat and estrogen in C. albicans. This study also suggests that Candida hsp90 is more likely to exist as an 82-kDa protein as predicted by a previously described cDNA and not as a 92-kDa protein as reported in the literature.