Skin sympathetic nerve activity as a biomarker for syncopal episodes during a tilt table test.

Background: Autonomic imbalance is the proposed mechanism of syncope during a tilt table test (TTT). We have recently demonstrated that skin sympathetic nerve activity (SKNA) can be noninvasively recorded using electrocardiographic electrodes.

Objective: The purpose of this study was to test the hypothesis that increased SKNA activation precedes tilt-induced syncope.

Effects of anesthetic and sedative agents on sympathetic nerve activity.

Background: The effects of sedative and anesthetic agents on sympathetic nerve activity (SNA) are poorly understood.

Objective: The purpose of this study was to determine the effects of commonly used sedative and anesthetic agents on SNA in ambulatory dogs and humans.

Methods: We implanted radiotransmitters in 6 dogs to record stellate ganglion nerve activity (SGNA), subcutaneous nerve activity (ScNA), and blood pressure (BP).

A dynamic loop provides dual control over the catalytic and membrane binding activity of a bacterial serine hydrolase.

The bacterial acyl protein thioesterase (APT) homologue FTT258 from the gram-negative pathogen Francisella tularensis exists in equilibrium between a closed and open state. Interconversion between these two states is dependent on structural rearrangement of a dynamic loop overlapping its active site. The dynamics and structural properties of this loop provide a simple model for how the catalytic activity of FTT258 could be spatiotemporally regulated within the cell.