IMA Postdoc Seminar (March 17, 2009)

Speaker: Wei Xiong (IMA)

Title: A Model for Liver Homeostasis Using a Modified Mean-reverting Ornstein-Uhlenbeck Process

Abstract: Short of a liver biopsy, hepatic disease and drug-induced liver injury are diagnosed and classified from clinical findings, especially laboratory results. It was hypothesized that a healthy hepatic dynamic equilibrium might be modeled by an Ornstein-Uhlenbeck (OU) stochastic process, which might lead to more sensitive and specific diagnostic criteria. Using pooled data from healthy volunteers in pharmaceutical clinical trials, this model was applied using maximum likelihood methods. It was found that the exponent of the autocorrelation function was proportional to the square root of time rather time itself, as predicted by the OU model. This finding suggests a stronger autocorrelation than expected and may have important implications regarding the use of laboratory testing in clinical diagnosis, in clinical trial design, and in monitoring drug safety.