Fixation of periprosthetic supracondylar femur fractures with a locking plate provided satisfactory results in nondiabetic patients. Diabetic patients seem to be at high risk for healing complications and infection.

Combined analysis of placental growth factor and vascular endothelial growth factor is potentially useful as a tool for early identification of patients at risk for developing severe, early-onset preeclampsia.

After a brief discussion of the threshold concept in toxicology, we consider models for the estimation of thresholds in the case where the observed response is binary or quantal. A generalization of the four-parameter Tukey-lambda family of distributions is proposed as a useful class of models for threshold estimation. Properties of these models are discussed and the process of model fitting and evaluation is illustrated using a number of data sets. The discussion includes consideration of background or spontaneous response, and comparison with other models. One of these is the linear-plateau or hockey-stick model, which has been used in a number of toxicological studies.

No abstract

The Delta Method, also known as the Method of Propagation of Errors, refers to applications of the result that a smooth function of an asymptotically normal estimator also has an asymptotic normal distribution. The delta method has two principal groups of applications, first to the computation of a variance stabilizing transformation, and second to the computation of the asymptotic variance and confidence intervals for a nonlinear function of a set of previously estimated parameters, typically by the method of maximum likelihood. This article discusses the proof of both the univariate and multivariate versions of the theorem and gives numerous examples.