Obesity is associated with muscle atrophy in rotator cuff tear.

Objective: The primary goal of this study is to evaluate the relationship between Body Mass Index (BMI) and muscle atrophy in individuals with rotator cuff tears. Methods: This study consists of patients with rotator cuff tears identified by MRI from two independent cohorts, the Rotator Cuff Outcomes Workgroup (ROW) and the Multicenter Orthopaedic Outcomes Network (MOON). Presence of atrophy (yes/no) and severity of atrophy (as an ordinal variable) were assessed on MRI by expert physicians. We used multivariable regression models to evaluate the relationship between BMI and muscle atrophy while adjusting for age and sex in each study, conducted sensitivity analyses for full-thickness tear and combined results using inverse variance-weighted meta-analysis. Results: A total of 539 patients (MOON=395, ROW=144) from the combined cohorts had MRI data available on muscle atrophy. Among these patients, 246 (46%) had atrophy of at least one of the muscles of the rotator cuff and 282 (52%) had full-thickness tears. In meta-analysis across both cohorts, each 5 kg/m2 increase in BMI was associated with a 21% (aOR=1.21, 95% CI=1.02, 1.43) increased odds of having muscle atrophy among individuals with any tear size, and 36% (aOR=1.36, 95% CI=1.01-1.81) increased odds among individuals with full-thickness tear. Conclusions: Higher BMI was associated with significantly higher odds of muscle atrophy in patiens with rotator cuff tears. More study is needed to unders1tand why and how this relationship exists, as well as whether interventions to reduce BMI may help improve outcomes for these patients. Level of Evidence: III.

Spatial mapping of mobile genetic elements and their bacterial hosts in complex microbiomes.

The exchange of mobile genetic elements (MGEs) facilitates the spread of functional traits including antimicrobial resistance within bacterial communities. Tools to spatially map MGEs and identify their bacterial hosts in complex microbial communities are currently lacking, limiting our understanding of this process. Here we combined single-molecule DNA fluorescence in situ hybridization (FISH) with multiplexed ribosomal RNA-FISH to enable simultaneous visualization of both MGEs and bacterial taxa. We spatially mapped bacteriophage and antimicrobial resistance (AMR) plasmids and identified their host taxa in human oral biofilms. This revealed distinct clusters of AMR plasmids and prophage, coinciding with densely packed regions of host bacteria. Our data suggest spatial heterogeneity in bacterial taxa results in heterogeneous MGE distribution within the community, with MGE clusters resulting from horizontal gene transfer hotspots or expansion of MGE-carrying strains. Our approach can help advance the study of AMR and phage ecology in biofilms.

Fluorescent protein tags affect the condensation properties of a phase-separating viral protein.

Fluorescent protein (FP) tags are extensively used to visualize and characterize the properties of biomolecular condensates despite a lack of investigation into the effects of these tags on phase separation. Here, we characterized the dynamic properties of µNS, a viral protein hypothesized to undergo phase separation and the main component of mammalian orthoreovirus viral factories. Our interest in the sequence determinants and nucleation process of µNS phase separation led us to compare the size and density of condensates formed by FP::µNS to the untagged protein. We found an FP-dependent increase in droplet size and density, which suggests that FP tags can promote µNS condensation. To further assess the effect of FP tags on µNS droplet formation, we fused FP tags to µNS mutants to show that the tags could variably induce phase separation of otherwise noncondensing proteins. By comparing fluorescent constructs with untagged µNS, we identified mNeonGreen as the least artifactual FP tag that minimally perturbed µNS condensation. These results show that FP tags can promote phase separation and that some tags are more suitable for visualizing and characterizing biomolecular condensates with minimal experimental artifacts.

Identifying key health system components associated with improved outcomes to inform the re-configuration of services for adults with rare autoimmune rheumatic diseases: a mixed-methods study.

BACKGROUND: Adults with rare autoimmune rheumatic diseases face unique challenges and struggles to navigate health-care systems designed to manage common conditions. Evidence to inform an optimal service framework for their care is scarce. Using systemic vasculitis as an exemplar, we aimed to identify and explain the key service components underpinning effective care for rare diseases. METHODS: In this mixed-methods study, data were collected as part of a survey of vasculitis service providers across the UK and Ireland, interviews with patients, and from organisational case studies to identify key service components that enable good care. The association between these components and patient outcomes (eg, serious infections, mortality) and provider outcomes (eg, emergency hospital admissions) were examined in a population-based data linkage study using routine health-care data obtained from patients with antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis from national health datasets in Scotland. We did univariable and multivariable analyses using Bayesian poisson and negative binomial regression to estimate incident rate ratios (IRRs), and Cox proportional hazards models to estimate hazard ratios (HRs). People with lived experiences were involved in the research and writing process. FINDINGS: Good care was characterised by service components that supported timely access to services, integrated care, and expertise. In 1420 patients with ANCA-associated vasculitis identified from national health datasets, service-reported average waiting times for new patients of less than 1 week were associated with fewer serious infections (IRR 0·70 [95% credibility interval 0·55-0·88]) and fewer emergency hospital admissions (0·78 [0·68-0·92]). Nurse-led advice lines were associated with fewer serious infections (0·76 [0·58-0·93]) and fewer emergency hospital admissions (0·85 [0·74-0·96]). Average waiting times for new patients of less than 1 week were also associated with reduced mortality (HR 0·59 [95% credibility interval 0·37-0·93]). Cohorted clinics, nurse-led clinics, and specialist vasculitis multi-disciplinary team meetings were associated with fewer serious infections (IRR 0·75 [0·59-0·96] for cohorted clinics; 0·65 [0·39-0·84] for nurse-led clinics; 0·72 [0·57-0·90] for specialist vasculitis multi-disciplinary team meetings) and emergency hospital admissions (0·81 [0·71-0·91]; 0·75 [0·65-0·94]; 0·86 [0·75-0·96]). Key components were characterised by their ability to overcome professional tensions between specialties. INTERPRETATION: Key service components associated with important health outcomes and underpinning factors were identified to inform initiatives to improve the design, delivery, and effectiveness of health-care models for rare autoimmune rheumatic diseases. FUNDING: Versus Arthritis.

Evaluation of the ARK Diagnostics immunoassay for qualitative detection of xylazine in urine.

Xylazine exposure is common in some US cities, but a commercial assay for routine laboratory testing for xylazine is not currently available. We evaluated a pre-release version of the ARK Diagnostics immunoassay for qualitative detection of xylazine/4-hydroxyxylazine in urine. Studies were conducted using either the semi-quantitative assay application (A. Roche Cobas 503 analyzer), or the qualitative assay application (B. Beckman Coulter AU480 analyzer). Study specimens consisted of deidentified patient urine samples submitted for routine drugs-of-abuse testing. Measurements of xylazine (X) were performed by LC-MS/MS, to obtain X-NEGATIVE (X<10 ng/mL) and X-POSITIVE (X≥10 ng/mL). The semi-quantitative ARK assay was calibrated with a 10 ng/mL cutoff for ARK-POSITVE. For (A): among 74 X-POSITIVE samples, there was 1 ARK-NEGATIVE result (false-negative rate=1.4%); among 78 X-NEGATIVE samples by LC-MS/MS, there were 0% ARK-POSITIVE results (false-positive rate = 0%). For (B), among 74 X-POSITIVE samples, there were 0 ARK-NEGATIVE results (false-negative rate=0%); among 78 X-NEGATIVE samples there was 1 ARK-POSITIVE sample (false-positive rate=1.3%). Common sources of interferences were investigated without evidence of interference. The ARK xylazine/4-OH-xylazine immunoassay was found to be suitable for routine use in screening patient urine samples for presence of xylazine >10 ng/mL.

Plant Membrane-On-A-Chip: A Platform for Studying Plant Membrane Proteins and Lipids.

The cell plasma membrane is a two-dimensional, fluid mosaic material composed of lipids and proteins that create a semipermeable barrier defining the cell from its environment. Compared with soluble proteins, the methodologies for the structural and functional characterization of membrane proteins are challenging. An emerging tool for studies of membrane proteins in mammalian systems is a "plasma membrane on a chip," also known as a supported lipid bilayer. Here, we create the "plant-membrane-on-a-chip,″ a supported bilayer made from the plant plasma membranes of Arabidopsis thaliana, Nicotiana benthamiana, or Zea mays. Membrane vesicles from protoplasts containing transgenic membrane proteins and their native lipids were incorporated into supported membranes in a defined orientation. Membrane vesicles fuse and orient systematically, where the cytoplasmic side of the membrane proteins faces the chip surface and constituents maintain mobility within the membrane plane. We use plant-membrane-on-a-chip to perform fluorescent imaging to examine protein-protein interactions and determine the protein subunit stoichiometry of FLOTILLINs. We report here that like the mammalian FLOTILLINs, FLOTILLINs expressed in Arabidopsis form a tetrameric complex in the plasma membrane. This plant-membrane-on-a-chip approach opens avenues to studies of membrane properties of plants, transport phenomena, biophysical processes, and protein-protein and protein-lipid interactions in a convenient, cell-free platform.

BDNF- and VEGF-Responsive Stimulus to an NGF Mimic Cyclic Peptide with Copper Ionophore Capability and Ctr1/CCS-Driven Signaling.

Neurotrophins are a family of growth factors that play a key role in the development and regulation of the functioning of the central nervous system. Their use as drugs is made difficult by their poor stability, cellular permeability, and side effects. Continuing our effort to use peptides that mimic the neurotrophic growth factor (NGF), the family model protein, and specifically the N-terminus of the protein, here we report on the spectroscopic characterization and resistance to hydrolysis of the 14-membered cyclic peptide reproducing the N-terminus sequence (SSSHPIFHRGEFSV (c-NGF(1-14)). Far-UV CD spectra and a computational study show that this peptide has a rigid conformation and left-handed chirality typical of polyproline II that favors its interaction with the D5 domain of the NGF receptor TrkA. c-NGF(1-14) is able to bind Cu2+ with good affinity; the resulting complexes have been characterized by potentiometric and spectroscopic measurements. Experiments on PC12 cells show that c-NGF(1-14) acts as an ionophore, influencing the degree and the localization of both the membrane transporter (Ctr1) and the copper intracellular transporter (CCS). c-NGF(1-14) induces PC12 differentiation, mimics the protein in TrkA phosphorylation, and activates the kinase cascade, inducing Erk1/2 phosphorylation. c-NGF(1-14) biological activities are enhanced when the peptide interacts with Cu2+ even with the submicromolar quantities present in the culture media as demonstrated by ICP-OES measurements. Finally, c-NGF(1-14) and Cu2+ concur to activate the cAMP response element-binding protein CREB that, in turn, induces the brain-derived neurotrophic factor (BDNF) and the vascular endothelial growth factor (VEGF) release.

The association of resilience and positive mental health in systemic sclerosis: A Scleroderma Patient-centered Intervention Network (SPIN) cohort cross-sectional study.

OBJECTIVE: A previous study using Scleroderma Patient-centered Intervention Network (SPIN) Cohort data identified five classes of people with systemic sclerosis (also known as scleroderma) based on patient-reported somatic (fatigue, pain, sleep) and mental health (anxiety, depression) symptoms and compared indicators of disease severity between classes. Across four classes ("low", "normal", "high", "very high"), there were progressively worse somatic and mental health outcomes and greater disease severity. The fifth ("high/low") class, however, was characterized by high disease severity, fatigue, pain, and sleep but low mental health symptoms. We evaluated resilience across classes and compared resilience between classes. METHODS: Cross-sectional study. SPIN Cohort participants completed the 10-item Connor-Davidson-Resilience Scale (CD-RISC) and PROMIS v2.0 domains between August 2022 and January 2023. We used latent profile modeling to identify five classes as in the previous study and multiple linear regression to compare resilience levels across classes, controlling for sociodemographic and disease variables. RESULTS: Mean CD-RISC score (N = 1054 participants) was 27.7 (standard deviation = 7.3). Resilience decreased progressively across "low" to "normal" to "high" to "very high" classes (mean 4.7 points per step). Based on multiple regression, the "high/low" class exhibited higher resilience scores than the "high" class (6.0 points, 95% confidence interval [CI] 4.9 to 7.1 points; standardized mean difference = 0.83, 95% CI 0.67 to 0.98). CONCLUSIONS: People with worse disease severity and patient-reported outcomes reported substantially lower resilience, except a class of people with high disease severity, fatigue, pain, and sleep disturbance but positive mental health and high resilience.

Immunoengineering can overcome the glycocalyx armour of cancer cells.

Cancer cell glycocalyx is a major line of defence against immune surveillance. However, how specific physical properties of the glycocalyx are regulated on a molecular level, contribute to immune evasion and may be overcome through immunoengineering must be resolved. Here we report how cancer-associated mucins and their glycosylation contribute to the nanoscale material thickness of the glycocalyx and consequently modulate the functional interactions with cytotoxic immune cells. Natural-killer-cell-mediated cytotoxicity is inversely correlated with the glycocalyx thickness of the target cells. Changes in glycocalyx thickness of approximately 10 nm can alter the susceptibility to immune cell attack. Enhanced stimulation of natural killer and T cells through equipment with chimeric antigen receptors can improve the cytotoxicity against mucin-bearing target cells. Alternatively, cytotoxicity can be enhanced through engineering effector cells to display glycocalyx-editing enzymes, including mucinases and sialidases. Together, our results motivate the development of immunoengineering strategies that overcome the glycocalyx armour of cancer cells.

Contemporary report of surgical outcomes after single-stage total pancreatectomy: A 10-year experience.

BACKGROUND: Surgeons rarely perform elective total pancreatectomy (TP). Our study seeks to report surgical outcomes in a contemporary series of single-stage (SS) TP patients. METHODS: Between the years 2013 to 2023 we conducted a retrospective review of 60 consecutive patients who underwent SSTP. Demographics, pathology, treatment-related variables, and survival were recorded and analyzed. RESULTS: SSTP consisted of 3% (60/1859) of elective pancreas resections conducted. Patient median age was 68 years. Ninety percent of these patients (n = 54) underwent SSTP for pancreatic ductal adenocarcinoma (PDAC). Conversion from a planned partial pancreatectomy to TP occurred intraoperatively in 31 (52%) patients. Fifty-nine patients (98%) underwent an R0 resection. Median length of hospital stay was 6 days. The majority of morbidities were minor, with 27% patients (n = 16) developing severe complications (Clavien-Dindo ≥3). Thirty and ninety-day mortality rates were 1.67% (one patient) and 5% (three patients), respectively. Median survival for the entire cohort was 24.4 months; 22.7 months for PDAC patients, with 1-, 3-, and 5-year survival of 68%, 43%, and 16%, respectively. No mortality occurred in non-PDAC patients (n = 6). CONCLUSION: Elective single-stage total pancreatectomy can be a safe and appropriate treatment option. SSTP should be in the armamentarium of surgeons performing pancreatic resection.

The Activity Management Inventory for Pain (AMI-P): Initial Development and Validation of a Questionnaire Based on Operant Learning and Energy Conservation Models of Activity Management.

OBJECTIVES: Activity management is an important treatment component in chronic pain programs. However, there are shortcomings in measures of this construct, leading to inconsistencies in research findings. Here, we describe the development of the Activity Management Inventory for Pain (AMI-P). MATERIALS AND METHODS: The AMI-P was developed by a group of international researchers with extensive expertise in both chronic pain and activity management. The initial evaluation of the AMI-P items included 2 studies that were both conducted in Canadian tertiary pain care centers. RESULTS: The resulting 20-item measure has 3 behavior scales (Rest, Alternating Activity, and Planned Activity), and 4 goal scales (Feel Less Pain, Get More Done, Complete the Task, and Save Energy). The behavior scales evidenced marginal to good internal consistency and test-retest reliability, and a moderate positive association with an existing pacing measure. The Rest and Alternating Activity scales were associated with greater pain interference, the Alternating Activity and Planned Activity scales were associated with less satisfaction with social roles, and the Planned Activity scale was associated with fewer depressive symptoms. The Alternating Activity scale increased significantly from pretreatment to posttreatment. All goal scales were positively associated with all behavior scales. The Feel Less Pain goal scale was positively associated with measures of avoidance and pain interference, while the Get More Done goal scale was negatively associated with measures of depressive symptoms and overdoing. DISCUSSION: The findings support the reliability and validity of the AMI-P scales, while also highlighting the complexity and multidimensional aspects of activity management.

The impact of study type and sleep measurement on oxygen desaturation index calculation.

STUDY OBJECTIVES: The oxygen desaturation index (ODI) is an important measure of sleep-disordered breathing during polysomnography (PSG); however, the AASM Manual (V3) does not specify whether to include oxygen desaturations occurring during wake epochs. Additionally, an ODI obtained from PSG can differ from an ODI using home sleep apnea tests (HSATs) that do not measure sleep, hampering diagnostic and treatment decision reliability. This study aimed to (1) compare an ODI that included all desaturations with an ODI that excluded desaturations occurring during wake epochs in PSG and (2) compare ODIs obtained from PSG with HSAT. METHODS: 100 consecutive PSGs for investigation of obstructive sleep apnea were compared. ODIs were calculated including all desaturations (ODIall) and by excluding desaturations entirely during wake epochs (ODIsleep). Additionally, we compared ODIall with an ODI calculated using monitoring time as the denominator (ODIHSAT). RESULTS: The median (interquartile range) 3% ODI for ODIall was 22.8 (13.1, 44.1) events/h and ODIsleep was 17.6 (11.5, 35.2) events/h (median difference: -3.9 events/h [-8.2, -0.9]; 21.0% [8.7%, 33.2%]). This discrepancy was larger with increasing ODI and decreasing sleep efficiency. The ODIHSAT was 17.4 (11.3, 35.2) events/h and the median reduction in ODIHSAT vs ODIall was -4.5 (-10.9, -2.0) events/h (21.6%; 11.1%, 33.8). CONCLUSIONS: ODI was significantly reduced when desaturations in wake epochs were excluded, and when ODI was based on monitoring time rather than sleep time, with the potential for underestimation of disease severity. Results suggest that ODI can differ substantially depending on the calculation and study type used, and that there is a need for standardization to ensure consistent diagnosis and treatment outcomes. CITATION: Whenn CB, Wilson DL, Ruehland WR, Churchward TJ, Worsnop C, Tolson J. The impact of study type and sleep measurement on oxygen desaturation index calculation. J Clin Sleep Med. 2024;20(5):709-717.