Collagen integrity of the annulus fibrosus in degenerative disc disease individuals quantified with collagen hybridizing peptide.

Introduction: Degenerative disc disease (DDD) is accompanied by structural changes in the intervertebral discs (IVD). Extra-cellular matrix degradation of the annulus fibrosus (AF) has been linked with degeneration of the IVD. Collagen is a vital component of the IVD. Collagen hybridizing peptide (CHP) is an engineered protein that binds to degraded collagen, which we used to quantify collagen damage in AF. This method was used to compare AF samples obtained from donors with no DDD to AF samples from patients undergoing surgery for symptomatic DDD. Methods: Fresh AF tissue was embedded in an optimal cutting temperature compound and cryosectioned at a thickness of 8 µm. Hematoxylin and Eosin staining was performed on sections for general histomorphological assessment. Serial sections were stained with Cy3-conjugated CHP and the mean fluorescence intensity and areal fraction of Cy3-positive staining were averaged for three regions of interest (ROI) on each CHP-stained section. Results: Increases in mean fluorescence intensity (p = 0.0004) and percentage of positively stained area (p = 0.00008) with CHP were detected in DDD samples compared to the non-DDD samples. Significant correlations were observed between mean fluorescence intensity and percentage of positively stained area for both non-DDD (R = 0.98, p = 5E-8) and DDD (R = 0.79, p = 0.0012) samples. No significant differences were detected between sex and the lumbar disc level subgroups of the non-DDD and DDD groups. Only tissue pathology (non-DDD versus DDD) influenced the measured parameters. No three-way interactions between tissue pathology, sex, and lumbar disc level were observed. Discussion and Conclusions: These findings suggest that AF collagen degradation is greater in DDD samples compared to non-DDD samples, as evidenced by the increased CHP staining. Strong positive correlations between the two measured parameters suggest that when collagen degradation occurs, it is detected by this technique and is widespread throughout the tissue. This study provides new insights into the structural alterations associated with collagen degradation in the AF that occur during DDD.

Amyloid fibril structures link CHCHD10 and CHCHD2 to neurodegeneration.

CHCHD10 is mutated in rare cases of FTD and ALS and aggregates in mouse models of disease. Here we show that the disordered N-terminal domain of CHCHD10 forms amyloid fibrils and report their cryoEM structure. Disease-associated mutations cannot be accommodated by the WT fibril structure, while sequence differences between CHCHD10 and CHCHD2 are tolerated, explaining the co-aggregation of the two proteins and linking CHCHD10 and CHCHD2 amyloid fibrils to neurodegeneration.

Association of Anticoagulant Choice on mortality in the Primary Treatment of Non-Cancer Venous Thromboembolism: Medicare 2011-2018.

Direct oral anticoagulants (DOACs; rivaroxaban, apixaban) and warfarin are approved for venous thromboembolism (VTE) treatment. Few direct comparisons of DOACs on risk of mortality among VTE patients exist, and for patients with concomitant conditions (e.g., kidney and liver disease) clinical guidelines are unclear. We evaluated 6-month all-cause mortality by anticoagulant prescribed for primary treatment of VTE. Using Medicare 20% sample data, we created a propensity score matched analytic dataset of 47,860 beneficiaries with non-cancer incident VTE. We used Cox regression to estimate adjusted hazard ratios (HRs) of OACs with 6-month mortality, and tested interactions by liver/kidney disease. There were 3,422 deaths over 6 months of follow-up. In adjusted models, patients prescribed rivaroxaban [HR: 0.82 (95% CI: 0.76-0.90)] had lower rates of mortality versus warfarin. There was no association comparing apixaban to warfarin [HR: 0.96 (95% CI: 0.87-1.07)]. In head-to-head comparisons of apixaban versus rivaroxaban the HR was 1.14 (95% CI: 1.01-1.28)]. Findings were similar among patients with liver and kidney disease. Overall, risk of death was similar by OAC prescribed. Though it is possible residual confounding remained, there was some suggestion of lower risk with rivaroxaban than warfarin. DOACs appear safe among VTE patients with concomitant kidney or liver disease.

Automated Cell Lineage Reconstruction using Label-Free 4D Microscopy.

Patterns of lineal descent play a critical role in the development of metazoan embryos. In eutelic organisms that generate a fixed number of somatic cells, invariance in the topology of their cell lineage provides a powerful opportunity to interrogate developmental events with empirical repeatability across individuals. Studies of embryonic development using the nematode Caenorhabditis elegans have been drivers of discovery. These studies have depended heavily on high throughput lineage tracing enabled by 4D fluorescence microscopy and robust computer vision pipelines. For a range of applications, computer-aided yet manual lineage tracing using 4D label-free microscopy remains an essential tool. Deep learning approaches to cell detection and tracking in fluorescence microscopy have advanced significantly in recent years, yet solutions for automating cell detection and tracking in 3D label-free imaging of dense tissues and embryos remain inaccessible. Here we describe embGAN, a deep learning pipeline that addresses the challenge of automated cell detection and tracking in label-free 3D time lapse imaging. embGAN requires no manual data annotation for training, learns robust detections that exhibits a high degree of scale invariance and generalizes well to images acquired in multiple labs on multiple instruments. We characterize embGAN's performance using lineage tracing in the C. elegans embryo as a benchmark. embGAN achieves near state-of-the-art performance in cell detection and tracking, enabling high-throughput studies of cell lineage without the need for fluorescent reporters or transgenics.

Hypertension Severity as Quantified by Hypertension Daily Dose and Blood Pressure With Risk of Stroke in REGARDS.

BACKGROUND: It is unknown how blood pressure (BP) relates to stroke risk across levels of hypertension daily dose (HDD)-quantified antihypertensive medication intensity. METHODS AND RESULTS: The REGARDS (Reasons for Geographic and Racial Differences in Stroke) study enrolled 30 239 participants from the 48 contiguous US states in 2003 to 2007 with in-person follow-up in 2013 to 2016 (Visit 2). We included those without prior stroke at Visit 2, treating this visit as T0. Biannual phone calls and medical record review ascertained incident stroke events. Cox proportional hazard models estimated the hazard ratio (HR) of incident stroke by treatment intensity defined by systolic BP stages and HDD groupings. There were 344 stroke events over a median 5.5 years. Relative to systolic BP <120 mm Hg and no antihypertensive medications, the stroke HR was 2.86 (95% CI, 1.68-4.85) for systolic BP 140 to 159 mm Hg and HDD tertile 2, 2.33 (1.37-3.97) for systolic BP 140 to 159 mm Hg and HDD tertile 3, 3.08 (1.20-7.88) for systolic BP ≥160 mm Hg and HDD tertile 2, and 3.66 (1.61-8.30) for systolic BP ≥160 mm Hg and HDD tertile 3. Stroke risk was similar across HDD levels for people with systolic BP <140 mm Hg. CONCLUSIONS: Among adults without prior stroke, systolic BP ≥140 mm Hg and HDD tertile ≥2 was associated with greater stroke risk. For adults with BP <140 mm Hg, stroke risk was similar despite cumulative dose of antihypertensive medications used. These findings support the practice of BP-lowering medications to mitigate stroke risk.

Mechanical Thromboprophylaxis and Hospital-Acquired Venous Thromboembolism Among Critically Ill Adolescents: A U.S. Pediatric Health Information Systems Registry Study, 2016-2023.

OBJECTIVES: To estimate the rate of mechanical thromboprophylaxis (mTP) prescription among critically ill adolescents using a multicenter administrative database and determine whether mTP prescription is inversely associated with hospital-acquired venous thromboembolism. DESIGN: Multicenter, observational, retrospective study of the Pediatric Health Information Systems (PHIS) Registry cohort, January 2016 to December 2023. SETTING: Thirty PICUs located within quaternary pediatric referral centers in the United States. PATIENTS: Critically ill children 12-17 years old, excluding encounters with a principal diagnosis at admission of venous thromboembolism. INTERVENTIONS: mTP prescription within the first 24 hours of hospitalization. MEASUREMENTS AND MAIN RESULTS: A total of 107,804 children met the study criteria, of which 21,124 (19.6%) were prescribed mTP. Hospital center prescribing rates ranged from 1.4% to 65.4% and decreased by 1.6% per year from 28.2% in 2016 to 17.1% in 2023. As compared with those without mTP, those with mTP more frequently had a concurrent central venous catheter (17.2% vs. 9.4%, p < 0.001), underwent invasive mechanical ventilation (37.4% vs. 24.8%, p < 0.001), were admitted for a primary surgical indication (30.9% vs. 12.7%, p < 0.001), and experienced a longer median duration of hospitalization (7 [interquartile range (IQR): 4-15] vs. 4 [IQR: 2-9] d, p < 0.001). Hospital-acquired venous thromboembolism occurred in 2.7% of the study sample and was more common among those with, as compared with without, prescription of mTP (4% vs. 2.4%, p < 0.001). In multivariable logistic regression models for hospital-acquired venous thromboembolism adjusting for salient prothrombotic risk factors, we failed to identify an association between mTP and greater odds of hospital-acquired venous thromboembolism (HA-VTE) among low-, moderate-, and high-risk tiers. However, we cannot exclude the possibility of 17-50% greater odds of HA-VTE in this population. CONCLUSIONS: In the multicenter PHIS cohort, 2016-2023, the prescribing patterns for mTP among critically ill adolescents showed a low rate of mTP prescription (19.6%) that varied widely across institutions, decreased annually over the study period by 1.6%/year, and was not independently associated with HA-VTE risk reduction.

Residues 2 to 7 of α-synuclein regulate amyloid formation via lipid-dependent and lipid-independent pathways.

Amyloid formation by α-synuclein (αSyn) occurs in Parkinson's disease, multiple system atrophy, and dementia with Lewy bodies. Deciphering the residues that regulate αSyn amyloid fibril formation will not only provide mechanistic insight but may also reveal targets to prevent and treat disease. Previous investigations have identified several regions of αSyn to be important in the regulation of amyloid formation, including the non-amyloid-ß component (NAC), P1 region (residues 36 to 42), and residues in the C-terminal domain. Recent studies have also indicated the importance of the N-terminal region of αSyn for both its physiological and pathological roles. Here, the role of residues 2 to 7 in the N-terminal region of αSyn is investigated in terms of their ability to regulate amyloid fibril formation in vitro and in vivo. Deletion of these residues (αSynΔN7) slows the rate of fibril formation in vitro and reduces the capacity of the protein to be recruited by wild-type (αSynWT) fibril seeds, despite cryo-EM showing a fibril structure consistent with those of full-length αSyn. Strikingly, fibril formation of αSynΔN7 is not induced by liposomes, despite the protein binding to liposomes with similar affinity to αSynWT. A Caenorhabditis elegans model also showed that αSynΔN7::YFP forms few puncta and lacks motility and lifespan defects typified by expression of αSynWT::YFP. Together, the results demonstrate the involvement of residues 2 to 7 of αSyn in amyloid formation, revealing a target for the design of amyloid inhibitors that may leave the functional role of the protein in membrane binding unperturbed.

Stable and accurate atomistic simulations of flexible molecules using conformationally generalisable machine learned potentials.

Computational simulation methods based on machine learned potentials (MLPs) promise to revolutionise shape prediction of flexible molecules in solution, but their widespread adoption has been limited by the way in which training data is generated. Here, we present an approach which allows the key conformational degrees of freedom to be properly represented in reference molecular datasets. MLPs trained on these datasets using a global descriptor scheme are generalisable in conformational space, providing quantum chemical accuracy for all conformers. These MLPs are capable of propagating long, stable molecular dynamics trajectories, an attribute that has remained a challenge. We deploy the MLPs in obtaining converged conformational free energy surfaces for flexible molecules via well-tempered metadynamics simulations; this approach provides a hitherto inaccessible route to accurately computing the structural, dynamical and thermodynamical properties of a wide variety of flexible molecular systems. It is further demonstrated that MLPs must be trained on reference datasets with complete coverage of conformational space, including in barrier regions, to achieve stable molecular dynamics trajectories.

Insights from Three Pan-European Multicentre Studies on Invasive Candida Infections and Outlook to ECMM Candida IV.

Invasive candidiasis and candidemia remain a significant public health concern. The European Confederation of Medical Mycology (ECMM) conducted three pan-European multicentre studies from 1997 to 2022 to investigate various aspects of invasive Candida infections. These studies revealed shifting trends in Candida species distribution, with an increase of non-albicans Candida species as causative pathogens, increasing rates of antifungal resistance, and persistently high mortality rates. Despite advancements in antifungal treatment, the persistently high mortality rate and increasing drug resistance, as well as limited drug access in low-income countries, underscore the need for continued research and development in the treatment of Candida infections. This review aims to summarize the findings of the three completed ECMM Candida studies and emphasize the importance of continued research efforts. Additionally, it introduces the upcoming ECMM Candida IV study, which will focus on assessing candidemia caused by non-albicans Candida species, including Candida auris, investigating antifungal resistance and tolerance, and evaluating novel treatment modalities on a global scale.

Versatile Method for Preparing Two-Dimensional Metal Dihalides.

Ever since the ground-breaking isolation of graphene, numerous two-dimensional (2D) materials have emerged with 2D metal dihalides gaining significant attention due to their intriguing electrical and magnetic properties. In this study, we introduce an innovative approach via anhydrous solvent-induced recrystallization of bulk powders to obtain crystals of metal dihalides (MX2, with M = Cu, Ni, Co and X = Br, Cl, I), which can be exfoliated to 2D flakes. We demonstrate the effectiveness of our method using CuBr2 as an example, which forms large layered crystals. We investigate the structural properties of both the bulk and 2D CuBr2 using X-ray diffraction, along with Raman scattering and optical spectroscopy, revealing its quasi-1D chain structure, which translates to distinct emission and scattering characteristics. Furthermore, microultraviolet photoemission spectroscopy and electronic transport reveal the electronic properties of CuBr2 flakes, including their valence band structure. We extend our methodology to other metal halides and assess the stability of the metal halide flakes in controlled environments. We show that optical contrast can be used to characterize the flake thicknesses for these materials. Our findings demonstrate the versatility and potential applications of the proposed methodology for preparing and studying 2D metal halide flakes.

Volatile Organic Compound Analysis of Malignant Pleural Mesothelioma Chorioallantoic Membrane Xenografts.

Malignant pleural mesothelioma (MPM) is an aggressive cancer associated with asbestos exposure. MPM is often diagnosed late, at a point where limited treatment options are available, but early intervention could the chances of successful treatment for MPM patients. Biomarkers to detect MPM in at-risk individuals are needed to implement early diagnosis technologies. Volatile organic compounds (VOCs) have previously shown diagnostic potential as biomarkers when analysed in MPM patient breath. In this study, chorioallantoic membrane (CAM) xenografts of MPM cell lines were used as models of MPM tumour development for VOC biomarker discovery with the aim of generating targets for investigation in breath, biopsies or other complex matrices. VOC headspace analysis of biphasic MESO-7T, epithelioid MESO-8T and MESO-12T MPM CAM xenografts was performed using solid-phase microextraction and gas chromatography-mass spectrometry. We successfully demonstrated the capture, analysis and separation of VOC signatures from CAM xenografts and controls. A panel of VOCs was identified that showed discrimination between MPM xenografts generated from biphasic and epithelioid cells and CAM controls. This is the first application of the CAM xenograft model for the discovery of VOC biomarkers associated with MPM histological subtypes. These findings support the potential utility of non-invasive VOC profiling from breath or headspace analysis of tissues for detection and monitoring of MPM.

Inhibitors of the small membrane (M) protein viroporin prevent Zika virus infection.

Flaviviruses, including Zika virus (ZIKV), are a significant global health concern, yet no licensed antivirals exist to treat disease. The small Membrane (M) protein plays well-defined roles during viral egress and remains within virion membranes following release and maturation. However, it is unclear whether M plays a functional role in this setting. Here, we show that M forms oligomeric membrane-permeabilising channels in vitro, with increased activity at acidic pH and sensitivity to the prototypic channel-blocker, rimantadine. Accordingly, rimantadine blocked an early stage of ZIKV cell culture infection. Structure-based channel models, comprising hexameric arrangements of two trans-membrane domain protomers were shown to comprise more stable assemblages than other oligomers using molecular dynamics (MD) simulations. Models contained a predicted lumenal rimantadine binding site, as well as a second druggable target region on the membrane-exposed periphery. In silico screening enriched for repurposed drugs/compounds predicted to bind to either one site or the other. Hits displayed superior potency in vitro and in cell culture compared with rimantadine, with efficacy demonstrably linked to virion-resident channels. Finally, rimantadine effectively blocked ZIKV viraemia in preclinical models, supporting that M constitutes a physiologically relevant target. This could be explored by repurposing rimantadine, or development of new M-targeted-therapies.

Optimizing Surgical Outcomes for Intracranial Epidermoid Tumors: A Retrospective Analysis of Clinical Predictors, Surgical Decisions, and Patient Clustering.

INTRODUCTION: Intracranial epidermoid tumors (ETs) are rare, benign lesions that present significant challenges in neurosurgical management due to their propensity to encase vital neurovascular structures. OBJECTIVE: To evaluate the impact of clinical, demographic, and tumor-specific factors on surgical decisions (gross total resection [GTR] vs. subtotal resection [STR]) and outcomes and identify patient clusters with distinct profiles and outcomes post-resection. METHODS: We retrospectively analyzed 72 epidermoid brain tumor patients treated from 1998 to 2022, employing multivariable logistic regression for GTR vs. STR predictors and Kaplan-Meier curves for progression-free survival (PFS). K-prototype clustering classified patients based on clinical data. RESULTS: The mean age of our cohort was 39.8±20.1 years. 13.9% of patients had a recurrence, with a median PFS of 108 months (IQR 57-206). Seizures significantly predicted GTR (p<0.05), whereas adherence to critical structures reduced GTR likelihood (p<0.05). Initial surgeries more often achieved GTR, correlating with longer PFS (p<0.0001) and reduced recurrence (p<0.01). History of previous ET surgery was predictive of increased recurrent tumor size (p<0.05) and reduced overall PFS (p<0.05). Clustering analysis revealed three clusters with significant differences in recurrence rates (p<0.0001), long term neurological deficits (p<0.05), PFS greater than 10 years (p<0.0001), and significant differences in median PFS between clusters 1 and 3 (p<0.0001) as well as 2 and three (p<0.01). CONCLUSION: This study emphasizes the importance of tailored surgical strategies in managing intracranial ETs, advocating for GTR to optimize long-term outcomes where possible. Future prospective studies are essential to further refine treatment approaches, enhancing survival for ET patients.

Validation of the International Medical Prevention Registry on Venous Thromboembolism (IMPROVE) risk scores for venous thromboembolism and bleeding in an independent population.

Background: Multiple guidelines recommend assessment of bleeding and venous thromboembolism (VTE) risk in adult medical inpatients to inform prevention strategies. There is no agreed-upon method for VTE and bleeding risk assessment. Objectives: To validate the International Medical Prevention Registry on Venous Thromboembolism (IMPROVE) VTE and bleeding risk scores in an independent population. Methods: In this retrospective study, we calculated the IMPROVE VTE and bleeding risk scores in medical inpatients admitted between 2010 and 2019 at the University of Vermont Medical Center (UVMMC). Patients were followed for in-hospital bleeding events while hospitalized and VTE events while hospitalized and for 3 months after discharge. We assessed calibration of the risk models by comparing the observed incidence of events in the UVMMC and IMPROVE populations across the published risk categories. We also assessed performance of the IMPROVE risk factors after refitting the models in the UVMMC population. Discrimination was assessed using the area under the receiver operating characteristic curve (AUC). Results: VTE occurred in 270 (1.1%) of 23,873 admissions, with 92 (34%) occurring during admission, and bleeding occurred in 712 (4.7%) of 15,240 admissions. When the IMPROVE-VTE risk factors were refitted to the UVMMC data, the AUC was 0.64. When the IMPROVE bleeding risk factors were refitted to the UVMMC data, the AUC was 0.67. The IMPROVE-VTE score tended to overestimate risk at higher scores, and the IMPROVE bleeding score underestimated risk at lower scores and overestimated risk at higher scores. Conclusion: While the refitted IMPROVE VTE and bleeding risk scores had reasonable model fit, the scores were poorly calibrated and did not reliably identify or differentiate patients at risk for VTE and bleeding. Different methods are needed for risk assessment of medical inpatients for VTE and bleeding risk.

The Relationship of Rumination, Worry and OCD Symptoms During Technology Supported Mindfulness Therapy for OCD.

BACKGROUND: In this study, we re-examined data from a previous randomized controlled trial investigating 'technology supported mindfulness' (TSM)-an 8-week treatment intervention for individuals experiencing OCD. The current analysis involves an examination of the longitudinal relationships between rumination, worry and OCD symptom changes during mindfulness treatment, in comparison to a waitlist control. METHODS: Participants experiencing OCD (n = 71) were randomly assigned to 8 weeks of (1) TSM or (2) waitlist control. We tested the extent to which rumination (using the Ruminative Response Scale) and worry (using the Penn State Worry Questionnaire) are associated with OCD symptom changes during the acute phase of treatment, concurrently (i.e., within the same longitudinal model). RESULTS: Generalized linear model (GLM) results indicated a significant time (week 1 vs. week 8) by condition interaction involving decreased rumination in the TSM condition: F(1, 61) = 13.37, p = 0.001, partial η2 = 0.18 and observed power = 0.94. A second GLM demonstrated decreased worry in the TSM condition: F(1, 69) = 37.34, p = 0.001, partial η2 = 0.35 and observed power = 0.83. Longitudinal 'latent difference' structural equation analyses demonstrated a cross-lagged association between worry (but not rumination) and OCD symptom changes. CONCLUSIONS: Individuals in the TSM condition experienced greater reductions in rumination and worry during 8 weeks of TSM treatment compared to the waitlist control, and reduced worry predicted subsequent OCD symptom reduction.

Methods, precision, and analytical sensitivity of a novel low-plasma-volume assay of fibrinolytic capacity utilizing the euglobulin fraction.

INTRODUCTION: Fibrinolysis is a critical aspect of the hemostatic system, with assessment of fibrinolytic potential being critical to predict bleeding and clotting risk. We describe the method for a novel low-plasma-volume assay of fibrinolytic capacity utilizing the euglobulin fraction (the "modified mini-euglobulin clot lysis assay [ECLA]"), its analytic sensitivity to alterations in key fibrinolytic substrates/regulators, and its initial applications in acute and convalescent disease cohorts. METHODS: The modified mini-ECLA requires 50 µL of plasma, a maximal read time of 3 h (with most results available within 60 min), and is entirely performed in a 96-well microplate. Assay measurements were obtained in a variety of commercial control and deficient plasmas representing clinically relevant hypo- and hyperfibrinolytic states, and in three distinct adolescent cohorts with acute or convalescent illness: critically ill, following endotracheal intubation; acute COVID-19-related illness; and ambulatory, 3 months following a venous thromboembolic event. RESULTS: In 100% and 75% deficient plasmas, hypofibrinolysis for plasminogen-deficient, fibrinolysis for alpha-2-antiplasmin-deficient, and hyperfibrinolysis for plasminogen activator inhibitor-1-deficient plasmas were observed. CONCLUSION: The modified mini-ECLA Clot Lysis Time Ratio ("CLTR") demonstrated moderate-strength correlations with the Clot Formation and Lysis (CloFAL) assay, is analytically sensitive to altered fibrinolytic states in vitro, and correlates with clinical outcomes in preliminarily-studied patient populations.