Measuring anxiety after spinal cord injury: Development and psychometric characteristics of the SCI-QOL Anxiety item bank and linkage with GAD-7

ObjectiveTo develop a calibrated item bank and computer adaptive test to assess anxiety symptoms in individuals with spinal cord injury (SCI), transform scores to the Patient Reported Outcomes Measurement Information System (PROMIS) metric, and create a statistical linkage with the Generalized Anxiety Disorder (GAD)-7, a widely used anxiety measure.DesignGrounded-theory based qualitative item development methods; large-scale item calibration field testing; confirmatory factor analysis; graded response model item response theory analyses; statistical linking techniques to transform scores to a PROMIS metric; and linkage with the GAD-7.SettingFive SCI Model System centers and one Department of Veterans Affairs medical center in the United States.ParticipantsAdults with traumatic SCI.ResultsSeven hundred sixteen individuals with traumatic SCI completed 38 items assessing anxiety, 17 of which were PROMIS items. After 13 items (including 2 PROMIS items) were removed, factor analyses confirmed unidimensionality. Item response theory analyses were used to estimate slopes and thresholds for the final 25 items (15 from PROMIS). The observed Pearson correlation between the SCI-QOL Anxiety and GAD-7 scores was 0.67.ConclusionsThe SCI-QOL Anxiety item bank demonstrates excellent psychometric properties and is available as a computer adaptive test or short form for research and clinical applications. SCI-QOL Anxiety scores have been transformed to the PROMIS metric and we provide a method to link SCI-QOL Anxiety scores with those of the GAD-7.     

Measuring grief and loss after spinal cord injury: Development,validation and psychometric characteristics of the SCI-QOL Grief and Loss item bank and short form

ObjectiveTo develop an item response theory (IRT) calibrated Grief and Loss item bank as part of the Spinal Cord Injury – Quality of Life (SCI-QOL) measurement system.DesignA literature review guided framework development of grief/loss. New items were created from focus groups. Items were revised based on expert review and patient feedback and were then field tested. Analyses included confirmatory factor analysis (CFA), graded response IRT modeling and evaluation of differential item functioning (DIF).SettingWe tested a 20-item pool at several rehabilitation centers across the United States, including the University of Michigan, Kessler Foundation, Rehabilitation Institute of Chicago, the University of Washington, Craig Hospital and the James J. Peters/Bronx Department of Veterans Affairs hospital.ParticipantsA total of 717 individuals with SCI answered the grief and loss questions.ResultsThe final calibrated item bank resulted in 17 retained items. A unidimensional model was observed (CFI = 0.976; RMSEA = 0.078) and measurement precision was good (theta range between −1.48 to 2.48). Ten items were flagged for DIF, however, after examination of effect sizes found this to be negligible with little practical impact on score estimates.ConclusionsThis study indicates that the SCI-QOL Grief and Loss item bank represents a psychometrically robust measurement tool. Short form items are also suggested and computer adaptive tests are available.     

Measuring positive affect and well-being after spinal cord injury: Development and psychometric characteristics of the SCI-QOL Positive Affect and Well-being bank and short form

ObjectiveTo develop an item response theory (IRT)-calibrated spinal cord injury (SCI)-specific Positive Affect and Well-being (PAWB) item bank with flexible options for administration.DesignQualitative feedback from patient and provider focus groups was used to expand on the Neurological Disorders and Quality of Life (Neuro-QOL) positive affect & well-being item bank for use in SCI. New items were created and revised based on expert review and patient feedback and were then field tested. Analyses included confirmatory factor analysis, graded response IRT modeling and evaluation of differential item functioning (DIF).SettingWe tested a 32-item pool at several rehabilitation centers across the United States, including the University of Michigan, Kessler Foundation, Rehabilitation Institute of Chicago, the University of Washington, Craig Hospital and the James J. Peters/Bronx Department of Veterans Affairs hospital.ParticipantsA total of 717 individuals with SCI answered the PAWB questions.ResultsA unidimensional model was observed (Confirmatory Fit Index = 0.947; Root Mean Square Error of Approximation = 0.094) and measurement precision was good (reliability in theta of –2.9 to 1.2 is roughly equivalent to classical reliability of 0.95 or above). Twelve items were flagged for DIF, however, after examination of effect sizes, the DIF was determined to be negligible and would have little practical impact on score estimates. The final calibrated item bank resulted in 28 retained itemsConclusionsThis study indicates that the Spinal Cord Injury – Quality of Life PAWB bank represents a psychometrically robust measurement tool. Short form items are also suggested and a computer adaptive test is available.     

Responsiveness of G protein-coupled odorant receptors is partially attributed to the activation mechanism

Mammals detect and discriminate numerous odors via a large family of G protein-coupled odorant receptors (ORs). However, little is known about the molecular and structural basis underlying OR response properties. Using site-directed mutagenesis and computational modeling, we studied ORs sharing high sequence homology but with different response properties. When tested in heterologous cells by diverse odorants, MOR256-3 responded broadly to many odorants, whereas MOR256-8 responded weakly to a few odorants. Out of 36 mutant MOR256-3 ORs, the majority altered the responses to different odorants in a similar manner and the overall response of an OR was positively correlated with its basal activity, an indication of ligand-independent receptor activation. Strikingly, a single mutation in MOR256-8 was sufficient to confer both high basal activity and broad responsiveness to this receptor. These results suggest that broad responsiveness of an OR is at least partially attributed to its activation likelihood.G protein-coupled receptors (GPCRs) are seven transmembrane (TM) proteins which play essential roles in converting extracellular stimuli into intracellular signals in a variety of cell types. Odor detection by olfactory sensory neurons (OSNs) in the mammalian nose depends on a large family of G protein-coupled odorant receptors (ORs) (1), which endows the olfactory system with an extraordinary power of odor detection and discrimination. Although OR-ligand binding is the first step toward smell perception, little is known about the molecular and structural basis underlying odor response properties of individual ORs.Most mammalian ORs respond to a small fraction of all of the tested odorants (2). In contrast, recent studies have identified a small number of ORs that respond to a large set of diverse odorants with comparable potency and efficacy as the former. Curiously, several broadly responsive ORs including MOR256-3 (Olfr124 or SR1), MOR256-31 (Olfr263), and human OR2W1 (ortholog of MOR256-31) belong to the same subfamily, which also contains ORs such as MOR256-8 (Olfr1362) and MOR256-22 (Olfr1387) that respond to a few odorants (3–6). Identification of ORs within the same subfamily (i.e., sharing >50% amino acid identity) but with different response properties offers an opportunity for dissecting out the molecular features that define the tuning properties of these ORs.Mammalian ORs belong to class A (or rhodopsin family) GPCRs. The structure-function relationship of several class A members (e.g., rhodopsin and β2-adrenergic receptor) has been investigated in great details via various approaches including site-directed mutagenesis, X-ray crystallography (7, 8), and molecular modeling (9–11). Although no crystal structure is available for any OR, site-directed mutagenesis and/or computational modeling have shed light on structure-function relationship for a few ORs (12–18).Using a joint approach of site-directed mutagenesis and computational modeling, we investigated the response properties of mutant ORs based on MOR256-3 and MOR256-8, which responded to a large and small set of odorants, respectively. Three-dimensional atomic models of these ORs were built to map locations of the mutated residues. Most mutations in MOR256-3 altered the responses to different odorants in a similar manner. Remarkably, MOR256-8 was converted into a broadly responsive OR by swapping a single or a few residues. More generally, we found that an OR’s total response was positively correlated with its basal activity, an indication of ligand-independent receptor activation. These data suggest that broad responsiveness of an OR is not only determined by ligand binding, but also by activation mechanism.     

Impact on Oncological Outcomes and Intent-to-Treat Survival of Resection Margin for Transplantable Hepatocellular Carcinoma in All-Comers and in Patients with Cirrhosis: A Multicenter Study

World Journal of Surgery - The outcomes of liver resection (LR) with a narrow margin in patients with transplantable hepatocellular carcinoma (HCC) have not been studied. The aim was to assess...     

Extracellular Vesicles Released From Articular Chondrocytes Play a Major Role in Cell–Cell Communication

The purpose of this investigation was to determine the role of extracellular vesicles (EVs), released from articular chondrocytes in a physiological or pathological state, in cell–cell communication with other articular chondrocytes or chondrocyte precursor cells. The conditioned medium from interleukin-1β (IL-1β)-treated human articular chondrocytes stimulated catabolic events and inhibited type II collagen expression in articular chondrocytes to a much greater degree than medium from IL-1β-treated chondrocytes after complete removal of EVs. The vehicle-treated and IL-1β-treated human articular chondrocytes released EVs of similar size; however, the number of EVs released by IL-1β-treated chondrocytes was markedly higher than the number of EVs released from the vehicle-treated cells. Furthermore, our findings demonstrate that similar to medium from IL-1β-treated chondrocytes containing EVs, EVs isolated from medium of IL-1β-treated chondrocytes stimulated catabolic events in articular chondrocytes, whereas EVs isolated from the medium of vehicle-treated chondrocytes inhibited catabolic events and increased messenger RNA levels of aggrecan and type II collagen in IL-1β-treated chondrocytes. Furthermore, the medium containing EVs from vehicle-treated articular chondrocytes or EVs isolated from this medium stimulated chondrogenesis of C3H10T1/2 cells, whereas medium containing EVs from IL-1β-treated chondrocytes or EVs isolated from this medium inhibited chondrogenesis. Our findings suggest that EVs released by articular chondrocytes play a key role in the communication between joint cells and ultimately in joint homeostasis, maintenance, pathology, and repair. © 2019 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 38:731-739, 2020