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T J McDermott

Publications and source records attributed to T J McDermott.

6 recordsLinked to original sources
PubMed1996

Defining the smallest analyte concentration an immunoassay can measure.

An immunoassay's minimal detectable concentration (MDC), the smallest analyte concentration the assay can reliably measure, is one of its most important properties. Bayes' theorem is used to unify the five current mathematical MDC definitions. The unified definition has significant implications for defining positive results for screening and diagnostic tests, setting criteria for immunoassay quality control and optimal design, reliably measuring biological substances at low concentrations, and, in general, measuring small analyte concentrations with calibrated analytic methods. As an illustration, we apply the unified definition to the microparticle capture enzyme immunoassay for prostate-specific antigen (PSA) developed for the Abbott IMx automated immunoassay system. The MDC of this assay as estimated by our unifying approach is shown to be 4.1-7.1 times greater than currently reported. As a consequence, the ability of the assay to measure reliably small concentrations of PSA to detect early recurrences of prostate cancer is probably overstated.

Humans↗
PubMed1993

The urinary light-chain ladder pattern. A product of improved methodology that may complicate the recognition of Bence Jones proteinuria.

OBJECTIVE: --To describe the recently reported urinary light-chain "ladder" pattern and to indicate that this phenomenon, which may give rise to confusion with Bence Jones protein (BJP), may be observed during routine examination of 50-fold concentrated urine samples tested by high-resolution agarose gel electrophoresis and immunofixation. METHODS: --Urine samples that were usually submitted for examination for the presence of BJP were concentrated 50-fold. Concentrated urine samples were subjected to immunoelectrophoresis and agarose gel electrophoresis. Samples that failed to show a BJP on immunoelectrophoresis but which did show a faint banding pattern in the stained agarose gel were subjected to immunofixation. RESULTS--Samples of urine from 23 patients failed to show a distinct BJP. Nevertheless, these samples did show a kappa, with or without a lambda, light-chain banding pattern. The urine samples came from patients with serum M components associated with neoplasms of either plasma cells (n = 2) or lymphocytes (n = 2) or with M components of undetermined significance (n = 6). The remainder came from patients with infectious (n = 8), inflammatory (n = 4), or neoplastic (n = 1) processes. Some of these patients had no apparent renal disease, while others had variably altered renal function. CONCLUSIONS--The urinary light-chain ladder pattern was found by routine examination of 50-fold concentrated urine samples subjected to agarose gel electrophoresis and immunofixation. The pattern probably reflects the limited heterogeneity of normal human light chains. Detection in the urine samples of some patients may reflect increased synthesis, failure of resorption/degradation in the kidney, or the interference in proximal tubular function by substances producing transient tubular proteinuria. The presence of the light-chain ladder pattern in urine may prevent the detection of small amounts of BJP sharing the electrophoretic mobility of one of the normal light-chain bands.

Adult↗
PubMed1989

Cartooning: a humorous approach to medical and health education.

This article explores the use of cartoons as valuable visual aids in medical and health education. Examples and descriptions are given of cartoons used in an instructional context for medical and allied health professions students, pediatric and adult patients, and hospital personnel. The article suggests content for effective cartoons, as well as basic guidelines for illustration style.

Allied Health Personnel↗