Effect of region-of-interest placement in bolus tracking cerebral computed tomography angiography.

Introduction: Premature or delayed triggering of semiautomatic contrast tracking during intracranial computed tomographic angiography can occur due to artifact from dense contrast in the superior vena cava or brachiocephalic veins near the anterior aortic arch. We determine if placement of bolus tracking region-of-interest in the posterior thoracic aorta can prevent suboptimal intracranial arterial opacification.

Methods: Intracranial computed tomography angiographies from 80 patients performed on the same scanner were retrospectively evaluated.

Distinct roles for the RSC and Swi/Snf ATP-dependent chromatin remodelers in DNA double-strand break repair.

The failure of cells to repair damaged DNA can result in genomic instability and cancer. To efficiently repair chromosomal DNA lesions, the repair machinery must gain access to the damaged DNA in the context of chromatin. Here we report that both the RSC and Swi/Snf ATP-dependent chromatin-remodeling complexes play key roles in double-strand break (DSB) repair, specifically by homologous recombination (HR).

Yeast RSC function is required for organization of the cellular cytoskeleton via an alternative PKC1 pathway.

RSC is a 15-protein ATP-dependent chromatin-remodeling complex related to Snf-Swi, the prototypical ATP-dependent nucleosome remodeler in budding yeast. Despite insight into the mechanism by which purified RSC remodels nucleosomes, little is known about the chromosomal targets or cellular pathways in which RSC acts. To better understand the cellular function of RSC, a screen was undertaken for gene dosage suppressors of sth1-3ts, a temperature-sensitive mutation in STH1, which encodes the essential ATPase subunit.