Homogeneous Oligomers of Pro-apoptotic BAX Reveal Structural Determinants of Mitochondrial Membrane Permeabilization.

BAX is a pro-apoptotic protein that transforms from a cytosolic monomer into a toxic oligomer that permeabilizes the mitochondrial outer membrane. How BAX monomers assemble into a higher-order conformation, and the structural determinants essential to membrane permeabilization, remain a mechanistic mystery. A key hurdle has been the inability to generate a homogeneous BAX oligomer (BAXO) for analysis. Here, we report the production and characterization of a full-length BAXO that recapitulates physiologic BAX activation. Multidisciplinary studies revealed striking conformational consequences of oligomerization and insight into the macromolecular structure of oligomeric BAX. Importantly, BAXO enabled the assignment of specific roles to particular residues and α helices that mediate individual steps of the BAX activation pathway, including unexpected functionalities of BAX α6 and α9 in driving membrane disruption. Our results provide the first glimpse of a full-length and functional BAXO, revealing structural requirements for the elusive execution phase of mitochondrial apoptosis.

Antiviral activity of bacterial TIR domains via immune signalling molecules.

The Toll/interleukin-1 receptor (TIR) domain is a canonical component of animal and plant immune systems1,2. In plants, intracellular pathogen sensing by immune receptors triggers their TIR domains to generate a molecule that is a variant of cyclic ADP-ribose3,4. This molecule is hypothesized to mediate plant cell death through a pathway that has yet to be resolved5. TIR domains have also been shown to be involved in a bacterial anti-phage defence system called Thoeris6, but the mechanism of Thoeris defence remained unknown. Here we show that phage infection triggers Thoeris TIR-domain proteins to produce an isomer of cyclic ADP-ribose. This molecular signal activates a second protein, ThsA, which then depletes the cell of the essential molecule nicotinamide adenine dinucleotide (NAD) and leads to abortive infection and cell death. We also show that, similar to eukaryotic innate immune systems, bacterial TIR-domain proteins determine the immunological specificity to the invading pathogen. Our results describe an antiviral signalling pathway in bacteria, and suggest that the generation of intracellular signalling molecules is an ancient immunological function of TIR domains that is conserved in both plant and bacterial immunity.

Covalent inhibition of pro-apoptotic BAX.

BCL-2-associated X protein (BAX) is a promising therapeutic target for activating or restraining apoptosis in diseases of pathologic cell survival or cell death, respectively. In response to cellular stress, BAX transforms from a quiescent cytosolic monomer into a toxic oligomer that permeabilizes the mitochondria, releasing key apoptogenic factors. The mitochondrial lipid trans-2-hexadecenal (t-2-hex) sensitizes BAX activation by covalent derivatization of cysteine 126 (C126). In this study, we performed a disulfide tethering screen to discover C126-reactive molecules that modulate BAX activity. We identified covalent BAX inhibitor 1 (CBI1) as a compound that selectively derivatizes BAX at C126 and inhibits BAX activation by triggering ligands or point mutagenesis. Biochemical and structural analyses revealed that CBI1 can inhibit BAX by a dual mechanism of action: conformational constraint and competitive blockade of lipidation. These data inform a pharmacologic strategy for suppressing apoptosis in diseases of unwanted cell death by covalent targeting of BAX C126.

Cyclic GMP-AMP signalling protects bacteria against viral infection.

The cyclic GMP-AMP synthase (cGAS)-STING pathway is a central component of the cell-autonomous innate immune system in animals1,2. The cGAS protein is a sensor of cytosolic viral DNA and, upon sensing DNA, it produces a cyclic GMP-AMP (cGAMP) signalling molecule that binds to the STING protein and activates the immune response3-5. The production of cGAMP has also been detected in bacteria6, and has been shown, in Vibrio cholerae, to activate a phospholipase that degrades the inner bacterial membrane7. However, the biological role of cGAMP signalling in bacteria remains unknown. Here we show that cGAMP signalling is part of an antiphage defence system that is common in bacteria. This system is composed of a four-gene operon that encodes the bacterial cGAS and the associated phospholipase, as well as two enzymes with the eukaryotic-like domains E1, E2 and JAB. We show that this operon confers resistance against a wide variety of phages. Phage infection triggers the production of cGAMP, which-in turn-activates the phospholipase, leading to a loss of membrane integrity and to cell death before completion of phage reproduction. Diverged versions of this system appear in more than 10% of prokaryotic genomes, and we show that variants with effectors other than phospholipase also protect against phage infection. Our results suggest that the eukaryotic cGAS-STING antiviral pathway has ancient evolutionary roots that stem from microbial defences against phages.

Nasal Mucosal Cytokines as Potential Biomarkers for Assessing Disease Severity and Class of Pathogen in Children with Community-Acquired Pneumonia.

BACKGROUND: Community-acquired pneumonia (CAP) is a leading cause of morbidity and mortality in children. Assessing disease severity and etiology remains challenging in the clinical setting. The objective of this study was to identify mucosal biomarkers that could potentially assist with patient classification. METHODS: We analyzed mucosal concentrations of cytokines in nasopharyngeal samples obtained from a convenience sample of 182 children with CAP and 26 matched healthy controls. Pathogens were identified by cultures and molecular assays. Severe disease was defined by hospital stay ≥ 3 days, and/or PICU admission. Data were analyzed according to identified pathogens and disease severity. RESULTS: Children with CAP and detected atypical bacteria had significantly higher concentrations of MCP-2, IFN-γ and CXCL10 among others compared with those with typical bacteria. Children with influenza virus had significantly higher concentrations of MCP-2, CXCL10, CXCL11, CX3CL1, and IFN-γ than those with typical bacteria. Additionally, children with severe CAP had significantly higher concentrations of CCL23 than children with mild/moderate disease, irrespective of the pathogen(s) identified. CONCLUSIONS: We identified differences in mucosal concentrations of inflammatory and antiviral cytokines in children with CAP according to disease severity and detected pathogens. Mucosal biomarkers represent a promising approach to help assessing disease severity and etiology.

Quantifying cell cycle regulation by tissue crowding.

The spatiotemporal coordination and regulation of cell proliferation is fundamental in many aspects of development and tissue maintenance. Cells have the ability to adapt their division rates in response to mechanical constraints, yet we do not fully understand how cell proliferation regulation impacts cell migration phenomena. Here, we present a minimal continuum model of cell migration with cell cycle dynamics, which includes density-dependent effects and hence can account for cell proliferation regulation. By combining minimal mathematical modeling, Bayesian inference, and recent experimental data, we quantify the impact of tissue crowding across different cell cycle stages in epithelial tissue expansion experiments. Our model suggests that cells sense local density and adapt cell cycle progression in response, during G1 and the combined S/G2/M phases, providing an explicit relationship between each cell-cycle-stage duration and local tissue density, which is consistent with several experimental observations. Finally, we compare our mathematical model's predictions to different experiments studying cell cycle regulation and present a quantitative analysis on the impact of density-dependent regulation on cell migration patterns. Our work presents a systematic approach for investigating and analyzing cell cycle data, providing mechanistic insights into how individual cells regulate proliferation, based on population-based experimental measurements.

Clinical Impact of Multiplex Molecular Diagnostic Testing in Children With Acute Gastroenteritis Presenting to an Emergency Department: A Multicenter Prospective Study.

BACKGROUND: Multiplex molecular diagnostic panels have greatly enhanced detection of gastrointestinal pathogens. However, data on the impact of these tests on clinical and patient-centered outcomes are limited. METHODS: We conducted a prospective, multicenter, stepped-wedge trial to determine the impact of multiplex molecular testing at 5 academic children's hospitals on children presenting to the emergency department with acute gastroenteritis. Caregivers were interviewed on enrollment and 7-10 days after enrollment to determine symptoms, risk factors, subsequent medical visits, and impact on family members. During the pre-intervention period, diagnostic testing was performed at the clinician's discretion . During the intervention period, multiplex molecular testing was performed on all children, with results available to clinicians. The primary outcome was return visits to a healthcare provider within 10 days of enrollment. RESULTS: Potential pathogens were identified by clinician-ordered tests in 19 of 571 (3.3%) in the pre-intervention period compared with 434 of 586 (74%) in the intervention period; clinically relevant pathogens were detected in 2.1% and 15%, respectively. In the multivariate model, the intervention was associated with a 21% reduction in the odds of any return visit (odds ratio, 0.79; 95% confidence interval, .70-.90) after adjusting for potential confounders. Appropriate treatment was prescribed in 11.3% compared with 19.6% during the intervention period (P = .22). CONCLUSIONS: Routine molecular multiplex testing for all children who presented to the ED with acute gastroenteritis detected more clinically relevant pathogens and led to a 21% decrease in return visits. Additional research is needed to define patients most likely to benefit from testing. Clinical Trials Registration. NCT02248285.

III-nitride m-plane violet narrow ridge edge-emitting laser diodes with sidewall passivation using atomic layer deposition.

A novel deep-ridge laser structure with atomic-layer deposition (ALD) sidewall passivation was proposed that enhances the optical characteristics of 8-µm ridge width III-nitride violet lasers on freestanding m-plane GaN substrates. The internal loss was determined using the variable stripe length method, where the laser structure with ALD sidewall passivation showed lower internal loss compared to the conventional shallow-ridge laser design. ALD sidewall passivation plays a critical role in device improvements; compared to the lasers without ALD sidewall passivation, the lasers with ALD sidewall passivation yield improved optoelectrical performance and longer lifetime under continuous-wave operation at high current density. This work demonstrates the importance of ALD sidewall passivation to laser performance, which enables high energy efficiency.

The discovery and evaluation of [18F]BMS-986229, a novel macrocyclic peptide PET radioligand for the measurement of PD-L1 expression and in-vivo PD-L1 target engagement.

PURPOSE: A same-day PET imaging agent capable of measuring PD-L1 status in tumors is an important tool for optimizing PD-1 and PD-L1 treatments. Herein we describe the discovery and evaluation of a novel, fluorine-18 labeled macrocyclic peptide-based PET ligand for imaging PD-L1. METHODS: [18F]BMS-986229 was synthesized via copper mediated click-chemistry to yield a PD-L1 PET ligand with picomolar affinity and was tested as an in-vivo tool for assessing PD-L1 expression. RESULTS: Autoradiography showed an 8:1 binding ratio in L2987 (PD-L1 (+)) vs. HT-29 (PD-L1 (-)) tumor tissues, with >90% specific binding. Specific radioligand binding (>90%) was observed in human non-small-cell lung cancer (NSCLC) and cynomolgus monkey spleen tissues. Images of PD-L1 (+) tissues in primates were characterized by high signal-to-noise, with low background signal in non-expressing tissues. PET imaging enabled clear visualization of PD-L1 expression in a murine model in vivo, with 5-fold higher uptake in L2987 (PD-L1 (+)) than in control HT-29 (PD-L1 (-)) tumors. Moreover, this imaging agent was used to measure target engagement of PD-L1 inhibitors (peptide or mAb), in PD-L1 (+) tumors as high as 97%. CONCLUSION: A novel 18F-labeled macrocyclic peptide radioligand was developed for PET imaging of PD-L1 expressing tissues that demonstrated several advantages within a nonhuman primate model when compared directly to adnectin- or mAb-based ligands. Clinical studies are currently evaluating [18F]BMS-986229 to measure PD-L1 expression in tumors.

Resting-state functional connectivity changes in older adults with sleep disturbance and the role of amyloid burden.

Sleep and related disorders could lead to changes in various brain networks, but little is known about the role of amyloid ß (Aß) burden-a key Alzheimer's disease (AD) biomarker-in the relationship between sleep disturbance and altered resting state functional connectivity (rsFC) in older adults. This cross-sectional study examined the association between sleep disturbance, Aß burden, and rsFC using a large-scale dataset from the Alzheimer's Disease Neuroimaging Initiative (ADNI). Sample included 489 individuals (53.6% cognitively normal, 32.5% mild cognitive impairment, and 13.9% AD) who had completed sleep measures (Neuropsychiatric Inventory), PET Aß data, and resting-state fMRI scans at baseline. Within and between rsFC of the Salience (SN), the Default Mode (DMN) and the Frontal Parietal network (FPN) were compared between participants with sleep disturbance versus without sleep disturbance. The interaction between Aß positivity and sleep disturbance was evaluated using the linear regressions, controlling for age, diagnosis status, gender, sedatives and hypnotics use, and hypertension. Although no significant main effect of sleep disturbance was found on rsFC, a significant interaction term emerged between sleep disturbance and Aß burden on rsFC of SN (ß = 0.11, P = 0.006). Specifically, sleep disturbance was associated with SN hyperconnectivity, only with the presence of Aß burden. Sleep disturbance may lead to altered connectivity in the SN when Aß is accumulated in the brain. Individuals with AD pathology may be at increased risk for sleep-related aberrant rsFC; therefore, identifying and treating sleep problems in these individuals may help prevent further disease progression.

Glucagon-like peptide-1 receptor agonists significantly affect the quality of bowel preparation for colonoscopy.

BACKGROUND: Glucagon-like peptide-1 receptor agonists (GLP-1RAs) affect gastrointestinal motility, slowing gastric emptying and colonic transit. GLP-1RAs have an impact on gastric residue before endoscopy, but only limited data are available regarding its effect on the adequacy of colonic preparation. We investigated the association between GLP-1RA use and inadequate bowel preparation (IBP) for colonoscopy. METHODS: We performed a multicenter retrospective study with GLP-1RA cases matched with controls (using propensity scores for age, sex, diabetes mellitus [DM], obesity, and co-morbidities). Data on demographics, medication use, procedural indications, and colonoscopy findings were collected. IBP ("poor preparation" on Aronchik scale or Boston Bowel preparation scale <5) was the primary outcome. RESULTS: 4876 patients treated with GLP-1RAs were included in the analysis and compared with 4876 controls selected from 333 648 patients without GLP-1RA use. Among the GLP-1RA patients, 10% (n = 487) had IBP compared with 197 (4%) of the control group (P<0.001). Subgroup analysis showed a higher rate of IBP among diabetic patients treated with GLP-1RA (284/2364 [12%]) than among diabetic patients without GLP-1RA treatment (118/2364 [5%]; P<0.001). Additionally, 203/2512 nondiabetic patients treated with GLP-1RAs had IBP (8%) compared with 79 of the nondiabetic non-GLP-1RA group (3%; P<0.001). On multivariate analysis, diabetes and GLP-1RA use were both found to be independent risk factors for IBP (odds ratio [OR] 1.4 and OR 2.7, respectively; both P<0.001). CONCLUSION: Our findings highlight the necessity for special attention and tailored recommendations for both diabetic and nondiabetic patients treated with GLP-1RAs in terms of colonic preparation prior to colonoscopy.

Optimal Control of Collective Electrotaxis in Epithelial Monolayers.

Epithelial monolayers are some of the best-studied models for collective cell migration due to their abundance in multicellular systems and their tractability. Experimentally, the collective migration of epithelial monolayers can be robustly steered e.g. using electric fields, via a process termed electrotaxis. Theoretically, however, the question of how to design an electric field to achieve a desired spatiotemporal movement pattern is underexplored. In this work, we construct and calibrate an ordinary differential equation model to predict the average velocity of the centre of mass of a cellular monolayer in response to stimulation with an electric field. We use this model, in conjunction with optimal control theory, to derive physically realistic optimal electric field designs to achieve a variety of aims, including maximising the total distance travelled by the monolayer, maximising the monolayer velocity, and keeping the monolayer velocity constant during stimulation. Together, this work is the first to present a unified framework for optimal control of collective monolayer electrotaxis and provides a blueprint to optimally steer collective migration using other external cues.

Practice variation in the management of pediatric intussusception: a narrative review.

Ileocolic intussusception, a major cause of acute intestinal obstruction in young children, necessitates rapid diagnosis and a multidisciplinary treatment approach. A recent large study identified variations in pain management, sedation, and non-operative reduction methods in these patients. We aimed to explore variability within the diagnostic and treatment pathways of ileocolic intussusception. A narrative review of the literature was conducted for peer-reviewed articles published in English between 2004 and 2024. We searched the electronic databases Ovid, Embase, Scopus, PubMed, and the Cochrane Database. Google Scholar was searched using the search terms "intussusception," "triage," "diagnosis," emergency department," "radiology," "ultrasound," "POCUS," "reduction," "air-enema," "fluid-enema," "pneumatic," "hydrostatic," "pain," "sedation," "operating-room," "laparoscopy," and "surgery" to identify articles published in electronic journals, books, and scientific websites. Data were analyzed by a multidisciplinary team of specialists in pediatric emergency medicine, pediatric radiology, and pediatric surgery. Fifty-six papers were included in this review. Six areas of practice variation were found: pain management in triage, the use of point-of-care ultrasound in the emergency department, the use of pneumatic versus hydrostatic technique for the reduction procedure, performing the reduction procedure under sedation, patient observation after an uncomplicated reduction, and the use of open surgery or laparoscopy for patients who underwent unsuccessful reduction. CONCLUSION: This review has identified practice variations in several key areas of ileocolic intussusception management. The findings underscore the need for further research in these areas and the establishment of uniform standards aimed at improving the care of children with ileocolic intussusception. WHAT IS KNOWN: • Ileocolic intussusception necessitates rapid diagnosis and a collaborative treatment approach involving emergency medicine, radiology, surgery, and often anesthesia. • A previous study reported variations in the practice of pain management and sedation among these patients. WHAT IS NEW: • This narrative review identified practice variations in several key areas within the diagnostic and treatment pathways of ileocolic intussusception.

Overriding native cell coordination enhances external programming of collective cell migration.

As collective cell migration is essential in biological processes spanning development, healing, and cancer progression, methods to externally program cell migration are of great value. However, problems can arise if the external commands compete with strong, preexisting collective behaviors in the tissue or system. We investigate this problem by applying a potent external migratory cue-electrical stimulation and electrotaxis-to primary mouse skin monolayers where we can tune cell-cell adhesion strength to modulate endogenous collectivity. Monolayers with high cell-cell adhesion showed strong natural coordination and resisted electrotactic control, with this conflict actively damaging the leading edge of the tissue. However, reducing preexisting coordination in the tissue by specifically inhibiting E-cadherin-dependent cell-cell adhesion, either by disrupting the formation of cell-cell junctions with E-cadherin-specific antibodies or rapidly dismantling E-cadherin junctions with calcium chelators, significantly improved controllability. Finally, we applied this paradigm of weakening existing coordination to improve control and demonstrate accelerated wound closure in vitro. These results are in keeping with those from diverse, noncellular systems and confirm that endogenous collectivity should be considered as a key quantitative design variable when optimizing external control of collective migration.

Tardigrades exhibit robust interlimb coordination across walking speeds and terrains.

Tardigrades must negotiate heterogeneous, fluctuating environments and accordingly utilize locomotive strategies capable of dealing with variable terrain. We analyze the kinematics and interleg coordination of freely walking tardigrades (species: Hypsibius exemplaris). We find that tardigrade walking replicates several key features of walking in insects despite disparities in size, skeleton, and habitat. To test the effect of environmental changes on tardigrade locomotor control circuits we measure kinematics and interleg coordination during walking on two substrates of different stiffnesses. We find that the phase offset between contralateral leg pairs is flexible, while ipsilateral coordination is preserved across environmental conditions. This mirrors similar results in insects and crustaceans. We propose that these functional similarities in walking coordination between tardigrades and arthropods is either due to a generalized locomotor control circuit common to panarthropods or to independent convergence onto an optimal strategy for robust multilegged control in small animals with simple circuitry. Our results highlight the value of tardigrades as a comparative system toward understanding the mechanisms-neural and/or mechanical-underlying coordination in panarthropod locomotion.

Trust in scientists in times of pandemic: Panel evidence from 12 countries.

This article analyzes the specific and critical role of trust in scientists on both the support for and compliance with nonpharmaceutical interventions (NPIs) during the COVID-19 pandemic. We exploit large-scale, longitudinal, and representative surveys for 12 countries over the period from March to December 2020, and we complement the analysis with experimental data. We find that trust in scientists is the key driving force behind individual support for and compliance with NPIs and for favorable attitudes toward vaccination. The effect of trust in government is more ambiguous and tends to diminish support for and compliance with NPIs in countries where the recommendations from scientists and the government were not aligned. Trust in others also has seemingly paradoxical effects: in countries where social trust is high, the support for NPIs is low due to higher expectations that others will voluntary social distance. Our individual-level longitudinal data also allows us to evaluate the effects of within-person changes in trust over the pandemic: we show that trust levels and, in particular, trust in scientists have changed dramatically for individuals and within countries, with important subsequent effects on compliant behavior and support for NPIs. Such findings point out the challenging but critical need to maintain trust in scientists during a lasting pandemic that strains citizens and governments.

Exploring the association between cognitive activity and symptom resolution following concussion in adolescents aged 11-17 years.

OBJECTIVE: As opposed to postconcussion physical activity, the potential influence of cognitive activity on concussion recovery is not well characterised. This study evaluated the intensity and duration of daily cognitive activity reported by adolescents following concussion and examined the associations between these daily cognitive activities and postconcussion symptom duration. METHODS: This study prospectively enrolled adolescents aged 11-17 years with a physician-confirmed concussion diagnosis within 72 hours of injury from the emergency department and affiliated concussion clinics. Participants were followed daily until symptom resolution or a maximum of 45 days postinjury to record their daily cognitive activity (intensity and duration) and postconcussion symptom scores. RESULTS: Participants (n=83) sustained their concussion mostly during sports (84%), had a mean age of 14.2 years, and were primarily male (65%) and white (72%). Participants reported an average of 191 (SD=148), 166 (SD=151) and 38 (SD=61) minutes of low-intensity, moderate-intensity and high-intensity daily cognitive activity postconcussion while still being symptomatic. Every 10 standardised minutes per hour increase in moderate-intensity or high-intensity cognitive activities postconcussion was associated with a 22% greater rate of symptom resolution (adjusted hazard ratio (aHR) 1.22, 95% CI 1.01 to 1.47). Additionally, each extra day's delay in returning to school postconcussion was associated with an 8% lower rate of symptom resolution (aHR 0.92, 95% CI 0.85 to 0.99). CONCLUSION: In adolescents with concussion, more moderate-high intensity cognitive activity is associated with faster symptom resolution, and a delayed return to school is associated with slower symptom resolution. However, these relationships may be bidirectional and do not necessarily imply causality. Randomised controlled trials are needed to determine if exposure to early cognitive activity can promote concussion recovery in adolescents.

Technical Success in Performing Esophageal High-Resolution Manometry in Patients with an Epiphrenic Diverticulum.

High-resolution manometry (HRM) is the gold standard for diagnosing esophageal motility disorders, yet it can be poorly tolerated and technically challenging. Epiphrenic diverticula (ED) are located in the distal esophagus and are associated with underlying motility disorders. ED patients (2008-2022) were retrospectively compared to achalasia patients (2008-2022) and all other patients (2021-2022) who underwent HRM at a single center. Complete success was defined as at least 7 interpretable swallows including measurements throughout the esophagus into the stomach. HRM studies involving children, previously treated achalasia, and sedation or endoscopic-assistance were excluded. 20 ED patients (mean age 66; 60% female) were compared to 76 achalasia patients and 199 controls. HRM was completely successful in 70.0% of ED patients, 85.5% of achalasia (p = 0.106 vs ED), and 91.0% of controls (p = 0.004 vs ED). Most failures in the ED and achalasia groups were due to inability to traverse the esophagogastric junction (EGJ), while patient intolerance was the main reason in controls. Half of the ED group had motility disorders (25% achalasia, 15% hypercontractile esophagus, 10% absent contractility). Large diverticulum size was inversely associated with technical success compared to small diverticulum size (40% vs 100%, p = 0.013), while the presence of a motility disorder did not significantly affect success (60% vs 88.9%, p = 0.303). In conclusion, ED is a predictor of unsuccessful HRM. This appears to be mainly related to an inability to traverse the EGJ due to the size of the diverticulum. Consideration should be given to alternative means of evaluating motility, such as endoscopy-assisted HRM, given the high likelihood of failure with traditional HRM.

Good Short-Term Survivorship of Constrained Condylar Revision Knee Implants With Medial Pivot Kinematics: A Level IV Retrospective Study.

BACKGROUND: The need for revision total knee arthroplasty surgery is increasing worldwide, and, in many cases, a constrained implant is required to provide joint stability. The purpose of this study was to examine the early loosening and functional outcome of a novel constrained condylar (CCK) revision total knee system designed to have medial pivot (MP) kinematics. METHODS: A retrospective cohort study was performed, collecting clinical data from all patients who underwent revision total knee arthroplasty using a novel MP CCK system with a minimum four-year clinical follow-up. Patient demographics, survivorship, complications, and Forgotten Joint Score were analyzed based upon chart review. RESULTS: There were 49 patients available for follow-up, who had a 100% survivorship free of aseptic loosening. All-cause revision survivorship was 92%. There were 4 patients who subsequently underwent rerevision. The causes for rerevision included periprosthetic joint infection in 2 patients, coronal plane instability in one patient, and a traumatic knee dislocation in one patient. There were 45 patients who completed the Forgotten Joint Score, who had an average of 49.8 (± 32.8, range 6.25 to 100). CONCLUSIONS: At 4 years, mid-term follow-up, this novel CCK revision total knee system designed to have MP kinematics had good patient-reported outcomes with no revision for aseptic loosening. Future studies should evaluate the mid- and long-term survivorship of this innovative implant.

Sleep-wake behavior, perceived fatigability, and cognitive reserve in older adults.

INTRODUCTION: The effects of sleep-wake behavior on perceived fatigability and cognitive abilities when performing daily activities have not been investigated across levels of cognitive reserve (CR). METHODS: CR Index Questionnaire (CRIq) data were collected and subjected to moderated mediation analysis. RESULTS: In amnestic mild cognitive impairment (aMCI; n = 41), CR moderated sleep-related impairments (SRIs), and fatigability at low CR (CRIq < 105.8, p = 0.004) and mean CR (CRIq = 126.9, p = 0.03) but not high CR (CRIq > 145.9, p = 0.65) levels. SRI affected cognitive abilities mediated by fatigability at low CR (p < 0.001) and mean CR (p = 0.003) levels. In healthy controls (n = 13), SRI in fatigability did not alter cognitive abilities across CR levels; controls had higher leisure scores than patients with aMCI (p = 0.003, effect size = 0.93). DISCUSSION: SRI can amplify impaired cognitive abilities through exacerbation of fatigability in patients with aMCI with below-mean CR. Therefore, improving sleep-wake regulation and leisure activities may protect against fatigability and cognitive decline. HIGHLIGHTS: Clinical fatigue and fatigability cannot be alleviated by rest. Clinical fatigability disrupts daily activities during preclinical Alzheimer's. High cognitive reserve mitigates sleep-wake disturbance effects. High cognitive reserve attenuates clinical fatigability effects on daily functioning. Untreated obstructive sleep apnea potentiates Alzheimer's pathology in the brain.