Stephen Barnhill

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DNA micro-arrays now permit scientists to screen thousands of genes simultaneously and determine whether those genes are active, hyperactive or silent in normal or cancerous tissue. Because these new micro-array devices generate bewildering amounts of raw data, new analytical methods must be developed to sort out whether cancer tissues have distinctive(More)
Over the last 15 years, substantial progress has been made in understanding the potential and the limitations of the CA 125 assay. More than 2000 papers have been published concerning laboratory and clinical studies of CA 125. The original CA 125 assay utilized the OC 125 antibody that recognizes the CA 125 epitope on a high molecular weight glycoprotein.(More)
Artificial neural networks (ANNs) are complex mathematical models that are distantly based on the human neuronal structure. They are capable of modeling elaborate biologic systems without making assumptions based on statistical distributions. Preliminary work has been reported on their application in urology. The initial results have been promising,(More)
A panel of four selected tumor markers, CA 125 II, CA 72-4, CA 15-3, and lipid-associated sialic acid, was analyzed collectively using an artificial neural network (ANN) approach to differentiate malignant from benign pelvic masses. A dataset of 429 patients, 192 of whom had malignant histology, was retrospectively used in the study. A prototype ANN(More)
OBJECTIVES Although prostate-specific antigen (PSA) has revolutionized the detection of prostate cancer, it has definite limitations with respect to its clinical sensitivity and specificity. Because a substantial number (20% to 40%) of men undergoing radical prostatectomy have a PSA level of 4.0 ng/mL or less, any new test offering diagnostic improvement(More) Volume 2 August 2009 A Four-Gene Expression Signature for Prostate Cancer Cells Consisting of UAP1, PDLIM5, IMPDH2, and HSPD1 UroToday International Journal ® UIJ INTRODUCTION: The objective of the study was to develop a gene expression test that is highly associated with the presence of prostate cancer for use as an(More)
The use of artificial neural networks (ANN) for the identification of a positive correlation between the QuiOs quotient, a single-valued indicator of bone mineral density, and multisite dual energy x-ray absorptiometry (DEXA) measurements is described. The measurements were obtained using the Hologic QDRR-2000 x-ray bone densitometer in a multicenter(More)
Multivariate classification methods were used to create an early detection technique for determining bone density. This biochemical index (QuiOs) is clinically useful as a potential adjunct in identifying the presence of biochemical deficiencies known to cause osteopenia and the devastating effects of osteoporosis. The test uses the following serum(More)