Publications by authors named "Claudia Chen"

Article Synopsis
  • Microbial growth rates are crucial for studying environmental geochemistry and ecology, but measuring activity at the single-cell level poses significant challenges in complex environments.
  • Stable isotope probing (SIP) is explored as a method to track microbial growth using isotopic labels, and this study specifically evaluates the use of Raman microspectroscopy for measuring deuterium (2H) in microbial biomass.
  • Findings suggest that Raman spectroscopy provides a more reliable measurement of microbial growth rates compared to nanoSIMS, paving the way for its application in analyzing microbial populations in complex samples effectively.
View Article and Find Full Text PDF

Introduction: Annual influenza vaccinations are recommended for adolescents and adults with moderate to severe asthma. This study investigated the effect of tezepelumab, a human monoclonal antibody that blocks the activity of thymic stromal lymphopoietin, on the humoral immune response to the quadrivalent seasonal influenza vaccine in patients with moderate to severe asthma.

Methods: VECTOR was a phase 3b, randomized, multicenter, double-blind, parallel-group, placebo-controlled study.

View Article and Find Full Text PDF

To survive during colony reproduction, bees create dense clusters of thousands of suspended individuals. How does this swarm, which is orders of magnitude larger than the size of an individual, maintain mechanical stability? We hypothesize that the internal structure in the bulk of the swarm, about which there is little prior information, plays a key role in mechanical stability. Here, we provide the first-ever 3D reconstructions of the positions of the bees in the bulk of the swarm using x-ray computed tomography.

View Article and Find Full Text PDF

Background: Tezepelumab is an anti-thymic stromal lymphopoietin monoclonal antibody in development for the treatment of severe asthma. This study assessed the functionality and performance of an accessorized pre-filled syringe (APFS) and an autoinjector (AI) for administration of tezepelumab in the clinic and at home.

Methods: This phase 3, multicenter, randomized, open-label, parallel-group study (PATH-HOME, ClinicalTrials.

View Article and Find Full Text PDF

The sequence-specific binding to DNA is crucial for the p53 tumor suppressor function. To investigate the constraints imposed on p53-DNA recognition by nucleosomal organization, we studied binding of the p53 DNA binding domain (p53DBD) and full-length wild-type p53 protein to a single p53 response element (p53RE) placed near the nucleosomal dyad in six rotational settings. We demonstrate that the strongest p53 binding occurs when the p53RE in the nucleosome is bent in the same direction as observed for the p53-DNA complexes in solution and in co-crystals.

View Article and Find Full Text PDF

This unit presents two methods of calcium phosphate-based eukaryotic cell transfection that can be used for both transient and stable transfections. In these protocols, plasmid DNA is introduced to monolayer cell cultures via a precipitate that adheres to the cell surface. A HEPES-buffered solution is used to form a calcium phosphate precipitate that is directly layered onto the cells.

View Article and Find Full Text PDF

This unit presents two methods of calcium phosphate-based eukaryotic cell transfection that can be used for both transient and stable transfections. In these protocols, plasmid DNA is introduced to monolayer cell cultures via a precipitate that adheres to the cell surface. A HEPES-buffered solution is used to form a calcium phosphate precipitate that is directly layered onto the cells.

View Article and Find Full Text PDF

Family 3 G-protein-coupled receptors (GPCRs), which includes metabotropic glutamate receptors (mGluRs), sweet and "umami" taste receptors (T1Rs), and the extracellular calcium-sensing receptor (CaR), represent a distinct group among the superfamily of GPCRs characterized by large amino-terminal extracellular ligand-binding domains (ECD) with homology to bacterial periplasmic amino acid-binding proteins that are responsible for signal detection and receptor activation through as yet unresolved mechanism(s) via the seven-transmembrane helical domain (7TMD) common to all GPCRs. To address the mechanism(s) by which ligand-induced conformational changes are conveyed from the ECD to the 7TMD for G-protein activation, we altered the length and composition of a 14-amino acid linker segment common to all family 3 GPCRs except GABA(B) receptor, in the CaR by insertion, deletion, and site-directed mutagenesis of specific highly conserved residues. Small alterations in the length and composition of the linker impaired cell surface expression and abrogated signaling of the chimeric receptors.

View Article and Find Full Text PDF

Mutations of the Sonic hedgehog (SHH) receptor, Patched1 (PTCH1), have been identified in a variety of tumors. PTCH1 is usually considered to be a tumor suppressor gene. However, one normal allele is retained in many tumors.

View Article and Find Full Text PDF