Bariatric Patient Engagement in a Pre-surgery Virtual Patient Navigation Platform (VPNP).

BACKGROUND: This study analyzed patient engagement with a virtual patient navigation platform (VPNP) designed to help guide bariatric surgery candidates through the complex pre-operative workup for surgery. METHODS: Data on baseline sociodemographic and medical history was collected on patients enrolled in the bariatric program at a single academic institution between March and May 2021. The System Usability Scale (SUS) survey was administered to assess VPNP usability. Two groups emerged: "engaged" (ENG; n = 30) who activated their accounts and completed the SUS, and "not-engaged" (NEG; n = 35) who did not activate their accounts (n = 13) or did not use the app (n = 22) and were therefore ineligible for the SUS survey. RESULTS: Analyses demonstrated that only insurance status differed between groups (private insurance: 60% versus 34.3% for ENG versus NEG, respectively; p = 0.038). SUS survey analysis demonstrated high perceived usability (median score = 86.3), corresponding to the 97th percentile of usability. The top three reasons for disengagement included being too busy (22.9%), not being interested (20%), and being unsure about the purpose of the app (20%). CONCLUSIONS: The VPNP scored in the 97th percentile of usability. However, given a majority of patients did not engage with the app, and engagement was associated with completing pre-surgery requirements faster (unpublished), future work will focus on mitigating identified reasons for patients not engaging.

Site-selective labeling and electron paramagnetic resonance studies of human cannabinoid receptor CB2.

Integral membrane G protein-coupled receptors (GPCR) regulate multiple physiological processes by transmitting signals from extracellular milieu to intracellular proteins and are major targets of pharmaceutical drug development. Since GPCR are inherently flexible proteins, their conformational dynamics can be studied by spectroscopic techniques such as electron paramagnetic resonance (EPR) which requires selective chemical labeling of the protein. Here, we developed protocols for selective chemical labeling of the recombinant human cannabinoid receptor CB2 by judiciously replacing naturally occurring reactive cysteine residues and introducing a new single cysteine residue in selected positions. The majority of the 47 newly generated single cysteine constructs expressed well in E. coli cells, and more than half of them retained high functional activity. The reactivity of newly introduced cysteine residues was assessed by incorporating nitroxide spin label and EPR measurement. The conformational transition of the receptor between the inactive and activated form were studied by EPR of selectively labeled constructs in the presence of either a full agonist CP-55,940 or an inverse agonist SR-144,528. We observed evidence for higher mobility of labels in the center of internal loop 3 and a structural change between agonist vs. inverse agonist-bound CB2 in the extracellular tip of transmembrane helix 6. Our results demonstrate the utility of EPR for studies of conformational dynamics of CB2.