Current research on opioid receptor function

Alcohol and drugs in epilepsy: pathophysiology, presentation, possibilities, and prevention

The potentially serious outcomes from ingestion of and dependence on toxins make this an important topic for epileptologists. We must be aware of the potential for harm from compounds that may be freely available, yet patients may try to conceal their use. Problematic compounds may cause seizures either acutely or on withdrawal: Their use may reduce effectiveness of antiepileptic drugs, or may simply promote and enhance chaotic lifestyles. Any or all of these factors may worsen seizure control or even directly cause seizures. This article highlights the pathophysiology behind provoked seizures, provides clues to diagnosis, and then outlines the steps that clinicians should take to reduce the deleterious effects of toxic compounds.

Grand opening of structure-guided design for novel opioids

Twelve years after the publication of the first crystal structure of a G-protein-coupled receptor (GPCR), experimental crystal structures of the four opioid receptor subtypes have made their entrance into the literature in the most extraordinary way, that is, all at once. Not only do these crystal structures contribute unprecedented molecular details of opioid ligand binding and specificity, but they also represent important tools for structure-based approaches to guide the discovery of safer and more efficient opioid therapeutics. We provide here an overview of these latest breakthroughs in the structural biology of GPCRs with a focus on differences and similarities between the four opioid receptor structures, as well as their limitations, in the context of challenges for translation of this new knowledge from bench to bedside.

A comprehensive statistical analysis of predicting in vivo hazard using high-throughput in vitro screening

Over the past 5 years, increased attention has been focused on using high-throughput in vitro screening for identifying chemical hazards and prioritizing chemicals for additional in vivo testing. The U.S. Environmental Protection Agency's ToxCast program has generated a significant amount of high-throughput screening data allowing a broad-based assessment of the utility of these assays for predicting in vivo responses. In this study, a comprehensive cross-validation model comparison was performed to evaluate the predictive performance of the more than 600 in vitro assays from the ToxCast phase I screening effort across 60 in vivo endpoints using 84 different statistical classification methods. The predictive performance of the in vitro assays was compared and combined with that from chemical structure descriptors. With the exception of chronic in vivo cholinesterase inhibition, the overall predictive power of both the in vitro assays and the chemical descriptors was relatively low. The predictive power of the in vitro assays was not significantly different from that of the chemical descriptors and aggregating the assays based on genes reduced predictive performance. Prefiltering the in vitro assay data outside the cross-validation loop, as done in some previous studies, significantly biased estimates of model performance. The results suggest that the current ToxCast phase I assays and chemicals have limited applicability for predicting in vivo chemical hazards using standard statistical classification methods. However, if viewed as a survey of potential molecular initiating events and interpreted as risk factors for toxicity, the assays may still be useful for chemical prioritization.