Biomedical subjects

L S Chavers

Publications and source records attributed to L S Chavers.

3 recordsLinked to original sources

PubMed2003

Vancomycin-resistant enterococci: 15 years and counting.

We review the history of vancomycin-resistant enterococci (VRE) and propose a causal model illustrating the roles of exposure to VRE reservoirs, patient characteristics, antimicrobial exposure, and prevalence of VRE in the progression from potential VRE reservoirs to active disease in hospitalized patients. Differences in VRE colonization and VRE infection are discussed with respect to hospital surveillance methodology and implications for interventions. We further document clonal transmission of VRE in a large, urban, teaching hospital and demonstrate VRE susceptibility to a wide array of antimicrobial agents. This model can guide the identification of mutable factors that are focal points for intervention.

Carrier State↗

PubMed2003

Association between antecedent intravenous antimicrobial exposure and isolation of vancomycin-resistant enterococci.

Vancomycin-resistant enterococci (VRE) have become important causes of nosocomial infections. This study evaluated the association between a variety of intravenous antimicrobial exposures and the isolation of VRE using two control groups: (1) a vancomycin-susceptible enterococci (VSE) group, to assess factors associated with development of VRE, and (2) a nonenterococci control group, to assess factors associated with positive cultures for enterococci without regard to vancomycin resistance. After adjusting for the effect of other antimicrobials, time at risk, and patient morbidity, compared to vancomycin-susceptible enterococci controls, exposures to imipenem (OR = 4.9, 95% CI = 1.6-14.1) and ceftazidime (OR = 2.6, 95% CI = 1.1-6.1) were significant predictors of VRE. When compared to nonenterococci controls, exposures to ampicillin (OR = 20.1, 95% CI = 1.5-263.1) and imipenem (OR = 5.1, 95% CI = 1.5-17.1) were significantly associated with VRE. Neither piperacillin nor vancomycin was associated with VRE compared to either control group. This study offers further evidence that the replacement of broad-spectrum cephalosporins by extended-spectrum penicillins, specifically piperacillin, may be effective in reducing VRE.

Adult↗

PubMed2002

The effect of three commonly used endodontic materials on the strength and hardness of root dentin.

The purpose of this study was to determine if calcium hydroxide, mineral trioxide aggregate, or sodium hypochlorite caused a change in the force required to fracture root dentin. Ten bovine central and lateral incisors were machined using various saws and drills to produce a cylinder of dentin with a 6.0-mm outer diameter 3.5-mm inner diameter and a length of 10 mm. The cylinders were cut lengthwise into four symmetrical pieces. The canal sides of the sections were then placed into Petri dishes containing a 1-mm depth of calcium hydroxide, mineral trioxide aggregate, sodium hypochlorite, or physiologic saline (control). The samples remained in the dishes for 5 weeks and were then shear tested by using an Instron machine. Data were analyzed using an ANOVA test for comparison of the groups as a whole, and a t test was used to compare each quarter section with its control from the same tooth. A 32% mean decrease in strength was discovered for calcium hydroxide, a 33% decrease in strength for mineral trioxide aggregate, and a 59% decrease for sodium hypochlorite. All decreases in strength were statistically significant: p < 0.001 for calcium hydroxide, p = 0.027 for mineral trioxide aggregate, and p < 0.001 for sodium hypochlorite. Results indicated that root dentin was weakened after 5 weeks of exposure to calcium hydroxide, mineral trioxide aggregate, or sodium hypochlorite.

Aluminum Compounds↗