The PH domain in the ArfGAP ASAP1 drives catalytic activation through an unprecedented allosteric mechanism.

ASAP1 is a multidomain Arf GTPase-activating protein (ArfGAP) that catalyzes GTP hydrolysis on the small GTPase Arf1 and is implicated in cancer progression. The PH domain of ASAP1 enhances its activity greater than 7 orders of magnitude but the underlying mechanisms remain poorly understood. Here, we combined Nuclear Magnetic Resonance (NMR), Molecular Dynamic (MD) simulations and mathematical modeling of functional data to build a comprehensive structural-mechanistic model of the complex of Arf1 and the ASAP1 PH domain on a membrane surface.

Submandibular Gland Flap Reconstruction for Oropharyngeal Defects After Transoral Robotic Surgery (TORS).

Background: To describe utilization and outcomes of submandibular gland flap (SGF) reconstruction after transoral robotic surgery (TORS) for oropharyngeal squamous cell carcinoma (OPSCC).

Methods: A multi-institutional retrospective case series of patients who underwent TORS for OPSCC followed by SGF reconstruction with harvest via transcervical approach from 1/1/2016 to 4/1/2023.

Results: In total, 14 patients underwent SGF reconstruction after TORS for OPSCC.

Metabolic profiling and antibacterial activity of tree wood extracts obtained under variable extraction conditions.

Introduction: Tree bacterial diseases are a threat in forestry due to their increasing incidence and severity. Understanding tree defence mechanisms requires evaluating metabolic changes arising during infection. Metabolite extraction affects the chemical diversity of the samples and, therefore, the biological relevance of the data.

Rare Prekallikrein Deficiency Identified During Workup of Isolated Prolonged Activated Partial Thromboplastin Time.

Prolongation of the activated partial thromboplastin time (aPTT) may signify an intrinsic factor deficiency or the presence of an inhibitor of coagulation, potentially placing a patient at increased risk for bleeding. However, a contact factor (ie, factor XII, prekallikrein, and high molecular weight kininogen) deficiency, which may also cause a prolonged aPTT, is not associated with clinical bleeding. A 71-year-old female had an isolated prolonged aPTT discovered during preoperative laboratory testing.

Understanding resource use and dietary niche partitioning in a high-altitude predator guild using seasonal sampling and DNA metabarcoding.

Understanding of predator feeding ecology, interactions among co-occurring predator species, and seasonal changes is critical for conservation management given the important role that predators play in shaping their ecosystems, but is lacking for most regions of the world. Dietary studies have demonstrated varying conclusions in the role that resource partitioning plays in the maintenance of predator communities due to complex inter-related factors that may shape prey use. We used DNA metabarcoding on 581 scat samples to determine the dietary composition, similarity, diversity, and niche overlap of eight predator species (Tibetan wolf (Canis lupus), snow leopard (Panthera uncia), Tibetan brown bear (Ursus arctos pruinosus), Eurasian lynx (Lynx lynx), Tibetan fox (Vulpes ferrilata), red fox (V.