OBJECTIVE: To assess quality control (QC) practices and their impact on hospital laboratories using the College of American Pathologists (CAP) Q-Probes process. DESIGN: Self-directed data gathering, using a questionnaire to determine QC practices, data input forms for 6 months retrospective quality control use and run failure rates, and input forms for 3 months prospective data concerning QC failure rates and corrective steps taken. Participants submitted data for four analytes: calcium, cholesterol, digoxin, and hemoglobin. PARTICIPANTS: Laboratories enrolled in the 1994 CAP Q-Probes program. MAIN OUTCOME MEASURES: Retrospective and prospective QC failure rates compared with QC protocols and the corrective steps. RESULTS: Five hundred five hospital laboratories returned various components of the study. Median retrospective run rejection rates per 1000 runs: calcium, 4.3; cholesterol, 3.6; digoxin, 4.3; and hemoglobin, 2.4. Corresponding median prospective run rejection rates per 1000 runs: calcium, 5.8; cholesterol, 5.6; digoxin, 6.5; and hemoglobin, 3.6. Participants resolved most out-of-control events in less than 20 minutes, with no patient samples repeated. More than 95% of the time, participants resolved out-of-control events simply by repeating controls. Most participants used a single control rule based on a target mean plus or minus a multiple of the standard deviation. A few laboratories used multirule systems. CONCLUSIONS: Current testing methods yield few out-of-control events, which usually are resolved rapidly, with little impact on laboratory operation. We recommend modification and simplification of laboratory QC practices to decrease false rejection rates and to use modern instrumentation more efficiently.

Calcium↗

PubMed1995

Evaluation of retinoid lactones as topical therapeutic agents in dermatology.

PURPOSE: Optimization of the therapeutic ratio of analogs of the topically active 11-cis, 13-cis-12-hydroxymethylretinoic acid, delta-lactone (1) relative to antihyperproliferation and antihyperkeratinization vs. toxicity. METHODS: Nine analogs of 1, in which variations were made in the lipophilic cyclohexenyl moiety or in the lactone ring, were evaluated for topical activity against hyperkeratinization, inhibition of TPA-induced DNA synthesis and for skin irritation. RESULTS: Although more potent lactones than the parent lactone 1 were identified, none possessed the favorable therapeutic ratio associated with 1. CONCLUSIONS: The delta-lactone 1 possesses unique molecular features responsible for its desirable therapeutic ratio as an antihyperproliferative and antihyperkeratotic agent. In view of its very low systemic retinoid toxicity and the absence of any systemic toxicity, this lactone may be a good candidate for use in the topical treatment of acne.

Administration, Topical↗

PubMed1994

Evaluation of retinoids as therapeutic agents in dermatology.

Evaluation of 13-cis-12-substituted analogues of retinoic acid in a series of dermatologic screens has revealed that structural modifications can lead to selectivity and specificity. An analogue, 11-cis,13-cis-12-hydroxymethylretinoic acid, delta-lactone, has been found to have good activity and to be devoid of topical and systemic toxicity.

Administration, Topical↗

PubMed1994