Dose-response analysis can be carried out using multi-purpose commercial statistical software, but except for a few special cases the analysis easily becomes cumbersome as relevant, non-standard output requires manual programming. The extension package drc for the statistical environment R provides a flexible and versatile infrastructure for dose-response analyses in general. The present versio...

Hormesis, a dose-response relationship phenomenon characterized by low-dose stimulation and high-dose inhibition, has been frequently observed in properly designed studies and is broadly generalizable as being independent of chemical/physical agent, biological model, and endpoint measured. This under-recognized and -appreciated concept has the potential to profoundly change toxicology and its r...

The main dose-response models for chronic toxicity are considered. For dichotomous response, the log probit, multi-hit, and multistage models are presented. For time-to-occurrence response, the log-normal and three variations of multistage models are presented. Finally, the Cornfield hockey-stick model is considered, and, for low-dose extrapolation, it is suggested that response be taken to be ...

This study was designed to investigate the role of GABAB receptor agents on imipramine-induced antinociception in ligated and non-ligated mice using hot-plate test. The data showed that different doses of morphine (3, 6, and 9 mg/kg) induced a dose-dependent antinociception in ligated and non-ligated mice. However, the opioid response was decreased in ligated animals. Intracerebroventricular (i...