Mediating role of perceived social support in the relationship between unemployment and mental distress among healthcare graduates during the COVID-19 era

Objective: This study investigates the mediating role of perceived social support in the relationship be ween unemployment and mental distress among young healthcare graduates in Bolivia during the COVID-19 pandemic. Methods: A cross-sectional analysis within a cohort study was conducted using data from 109 healthcare graduates from Bolivia collected through an online survey in 2022. The survey measured employment status, mental distress with the 12-item General Health Questionnaire (GHQ-12), and perceived social support using the Multidimensional Scale of Perceived Social Support (MSPSS). Mediation analysis was performed in R to examine the mediating effect of perceived social support on the relationship between unemployment and mental distress. Results: More than two-thirds of participants reported mental distress. Consistent with the main effect model, employment was directly associated with lower levels of mental distress, and perceived social support was positively related to better mental health. However, perceived social support did not statistically significant mediate the impact of unemployment on mental distress, with only 2.1% of the effect being mediated through perceived social support. Conclusion: Despite the beneficial effect of perceived social support on mental health, it did not signifcantly mediate the relationship between unemployment and mental distress among Bolivian healthcare graduates during COVID-19. The findings highlight the need for targeted mental health support that go beyond social support for unemployed healthcare graduates during crises

Intraocular Lens Power Calculation—Comparing Big Data Approaches to Established Formulas

Purpose To evaluate the predictive performance of traditional intraocular lens (IOL) power calculation formulas (e.g., SRK/T, Haigis, Hoffer Q, and Holladay I) compared to advanced regression models, including classical linear models, regression splines, and random forest regression, in predicting postoperative refraction following cataract surgery. Design Retrospective, comparative analysis of IOL power calculations. Subjects The study included 886 eyes from 631 patients who underwent cataract surgery with monofocal aspherical IOL implantation. Methods Biometric measurements were obtained using optical biometry (IOLMaster 700), and postoperative refraction was assessed at least 4 weeks after surgery. Formula constants for 5 IOL formulas (SRK/T, Haigis, Hoffer Q, Holladay I and Castrop V1) were optimized using root mean squared error (RMSE). Regression models (classical linear model, regression splines, and random forest regression) were trained on 4 datasets categorized by axial length (AL); normal, short, long, and random. Model performance was assessed using mean absolute error (MAE), RMSE, and prediction error variance, for both in-sample and out-of-sample predictions. Main Outcome Measures The primary parameters measured were MAE, RMSE, and prediction error variance. Results Regression models outperformed traditional IOL formulas in in-sample prediction error. Overall, linear regression models performed similarly to traditional formulas with respect to out-of-sample prediction error. The lowest out-of-sample prediction error (MAE = 0.279, RMSE = 0.359) was achieved with a model where effects of some covariates (R2, AL, CCT) were modelled as nonlinear via regression splines. This model outperformed all traditional formulas, and the Castrop formula, which had the lowest errors among the formulas (MAE = 0.284, RMSE = 0.359). Random forest regression showed strong in-sample performance but poor out-of-sample generalizability due to overfitting. Conclusions Regression models which allow for nonlinear effects, e.g. based on regression splines, provide a promising alternative to traditional IOL formulas for predicting postoperative refraction. Linear regression and random forest regression models can reduce in-sample error, however, their clinical utility is currently limited by out-of-sample performance. Future work should focus on improving generalizability and integrating machine learning models into clinical practice to enhance refractive outcomes, especially for eyes with atypical anatomy

High Agreement Across Laboratories Between Different Alpha‐Synuclein Seed Amplification Protocols

Background: Seed amplification assays (SAA) detect alpha-synuclein (aSYN) pathology in patient biomatrices such as cerebrospinal fluid (CSF)—potentially even before clinical manifestations. As CSF-based SAA are approaching broader use in clinical trials and research, ensuring that different laboratories obtain the same results becomes increasingly important. Methods: In this cross-laboratory, cross-aSYN-recombinant substrate and cross-protocol round-robin test, we compared SAA results from a common set of 38 CSF samples measured independently in four research laboratories of the German Center for Neurodegenerative diseases. Three laboratories (A–C) used an assay protocol adapted from Parchi's group at ISNB (Bologna, Italy); laboratory D used an assay protocol adapted from Amprion Inc. Two different manufacturers of aSYN protein were used as substrates for the SAA reaction. Results: Qualitative results were identical in at least three of the four laboratories for 37 out of 38 samples (20 positive, 17 negative). Fleiss Kappa for all four laboratories was 0.751 (z = 12, p  92%. For the number of positive replicates, Fleiss Kappa was 0.45 for a score of zero positive replicates and 0.42 for a score of four positive replicates. Conclusions: The qualitative SAA results showed a high level of agreement across research laboratories, aSYN monomers, and assay protocols. Small differences between laboratories were systematic, consistent with the notion that SAA reports biologically relevant properties. These results also underline that round-robin tests can be helpful in assessing and ensuring SAA quality across laboratories

Fibrillar amyloidosis and synaptic vesicle protein expression progress jointly in the cortex of a mouse model with β-amyloid pathology

Neurodegeneration, accumulation of β-amyloid (Aβ) plaques, and neuroinflammation are the major hallmarks of Alzheimer's disease. Here, we aimed to investigate the temporal and spatial association between synaptic activity, Aβ plaque load, and neuroinflammation in an Aβ mouse model with limited neurodegeneration. 26 APPSL70 and 15 C57Bl/6 mice underwent longitudinal PET-scans with [18F]UCB-H from plaque onset to levels of strong plaque load (5.3 - 11.0 months of age) to assess the synaptic vesicle protein 2A (SV2A) expression, [18F]FBB to determine the fibrillar Aβ plaque load, and [18F]GE-180 and [18F]F-DED to assess microglial and astroglial (re)activity. Statistical parametric mapping was performed to uncover similarities between the binding patterns of all four tracers. We found a continuous increase in Aβ-PET in APPSL70 mice from 5.3 to 11.0 months of age, resulting in a significantly higher [18F]FBB PET signal in the cortex, hippocampus, and thalamus of APPSL70 mice compared to C57Bl/6 mice at 11.0 months of age. Parallel increases in SV2A-PET signals were observed in the cortex and thalamus of APPSL70 mice compared to C57Bl/6 mice. Statistical parametric mapping revealed a similar pattern of Aβ- and SV2A-PET differences (dice coefficient 53 %). Patterns of microglia activation showed stronger congruency with SV2A expression (dice coefficient 58 %) than patterns of reactive astrogliosis (dice coefficient 26 %). APPSL70 mice with limited neurodegeneration comprise a close temporal and spatial association between SV2A expression, Aβ plaque load, and microglial activation. SV2A PET imaging in APPSL70 mice may facilitate longitudinal monitoring of increased synaptic activity in the earliest phase of AD

Ezh2 Shapes T Cell Plasticity to Drive Atherosclerosis

Background:The activation and polarization of T cells play a crucial role in atherosclerosis and dictate athero-inflammation. The epigenetic enzyme EZH2 (enhancer of zeste homolog 2) mediates the H3K27me3 (trimethylation of histone H3 lysine 27) and is pivotal in controlling T cell responses. Methods:To detail the role of T cell EZH2 in atherosclerosis, we used human carotid endarterectomy specimens to reveal plaque expression and geography of EZH2. Atherosclerosis-prone Apoe (apolipoprotein E)–deficient mice with CD (cluster of differentiation) 4+ or CD8+ T cell–specific Ezh2 deletion (Ezh2cd4-knockout [KO], Ezh2cd8-KO) were analyzed to unravel the role of T cell Ezh2 in atherosclerosis and T cell–associated immune status. Results:EZH2 expression is elevated in advanced human atherosclerotic plaques and primarily expressed in the T cell nucleus, suggesting the importance of canonical EZH2 function in atherosclerosis. Ezh2cd4-KO, but not Ezh2cd8-KO, mice showed reduced atherosclerosis with fewer advanced plaques, which contained less collagen and macrophages, indicating that Ezh2 in CD4+ T cells drives atherosclerosis. In-depth analysis of CD4+ T cells of Ezh2cd4-KO mice revealed that absence of Ezh2 results in a type 2 immune response with increased Il-4 (interleukin 4) gene and protein expression in the aorta and lymphoid organs. In vitro, Ezh2-deficient T cells polarized macrophages toward an anti-inflammatory phenotype. Single-cell RNA-sequencing of splenic T cells revealed that Ezh2 deficiency reduced naive, Ccl5+ (C-C motif chemokine ligand 5) and regulatory T cell populations and increased the frequencies of memory T cells and invariant natural killer T (iNKT) cells. Flow cytometric analysis identified a shift toward Th2 (type 2 T helper) effector CD4+ T cells in Ezh2cd4-KO mice and confirmed a profound increase in splenic iNKT cells with increased expression of Plzf (promyelocytic leukemia zinc finger), which is the characteristic marker of the iNKT2 subset. Likewise, Zbtb16 ([zinc finger and BTB domain containing 16], a Plzf-encoding gene) transcripts were elevated in the aorta of Ezh2cd4-KO mice, suggesting an accumulation of iNKT2 cells in the plaque. H3K27me3–chromatin immunoprecipitation followed by quantitative polymerase chain reaction showed that T cell–Ezh2 regulates the transcription of the Il-4 and Zbtb16 genes. Conclusions:Our study uncovers the importance of T cell EZH2 in human and mouse atherosclerosis. Inhibition of Ezh2 in CD4+ T cells drives type 2 immune responses, resulting in an accumulation of iNKT2 and Th2 cells, memory T cells and anti-inflammatory macrophages that limit the progression of atherosclerosis

Acute suppression of mitochondrial ATP production prevents apoptosis and provides an essential signal for NLRP3 inflammasome activation

How mitochondria reconcile roles in functionally divergent cell death pathways of apoptosis and NLRP3 inflammasome-mediated pyroptosis remains elusive, as is their precise role in NLRP3 activation and the evolutionarily conserved physiological function of NLRP3. Here, we have shown that when cells were challenged simultaneously, apoptosis was inhibited and NLRP3 activation prevailed. Apoptosis inhibition by structurally diverse NLRP3 activators, including nigericin, imiquimod, extracellular ATP, particles, and viruses, was not a consequence of inflammasome activation but rather of their effects on mitochondria. NLRP3 activators turned out as oxidative phosphorylation (OXPHOS) inhibitors, which we found to disrupt mitochondrial cristae architecture, leading to trapping of cytochrome c. Although this effect was alone not sufficient for NLRP3 activation, OXPHOS inhibitors became triggers of NLRP3 when combined with resiquimod or Yoda-1, suggesting that NLRP3 activation requires two simultaneous cellular signals, one of mitochondrial origin. Therefore, OXPHOS and apoptosis inhibition by NLRP3 activators provide stringency in cell death decisions

Serum anti-NMDA receptor antibodies are linked to memory impairment 12 months after stroke

Patients suffering from strokes are at increased risk of developing post-stroke dementia. Serum anti-NMDA receptor autoantibodies (NMDAR1-abs) have been associated with unfavorable post-stroke outcomes. However, their effect on specific cognitive domains remains unclear. We used data from the prospective multicenter DZNE—mechanisms after stroke (DEMDAS) cohort, and measured NMDAR1-abs in serum at baseline. Cognitive function was assessed with a comprehensive neuropsychological test battery at 6- and 12-months follow-up. We employed crude and stepwise confounder adjusted linear and logistic regression models as well as generalized estimating equation models (GEE) to determine the relevance of NMDAR1-abs seropositivity on cognitive function after stroke. 10.2% (58/569) DEMDAS patients were NMDAR1-abs seropositive (IgM:n = 44/IgA:n = 21/IgG:n = 2). Seropositivity was not associated with global cognitive impairment after stroke. However, NMDAR1-abs seropositive patients performed lower in the memory domain (βadjusted = −0.11; 95%CI = −0.57 to −0.03) and were at increased risk for memory impairment (ORadjusted = 3.8; 95%CI = 1.33–10.82) compared to seronegative patients, 12 months after stroke. Further, NMDAR1-abs were linked to memory impairment over time in GEE from 6- to 12-months follow-up (ORadjusted = 2.41; 95%CI = 1.05–5.49). Our data suggests that NMDAR1-abs contribute to memory dysfunction 1 year after stroke while not affecting other cognitive subdomains. Hence, antineuronal autoimmunity may be involved in distinct mechanisms of post-stroke memory impairment. Clinical trial name and registration number: The Determinants of Dementia After Stroke (DEMDAS; study identifier on clinical trials.gov: NCT01334749

Developing and characterising bovine decellularized extracellular matrix hydrogels to biofabricate female reproductive tissues

This study investigated the development and characterization of decellularized extracellular matrix (dECM) hydrogels tailored for the biofabrication of female reproductive tissues, specifically targeting ovarian cortex, endometrium, ovarian medulla, and oviduct tissues. We aimed to evaluate the cytocompatibility, biomechanical properties, and overall efficacy of these dECMs in promoting cell viability, proliferation, and morphology using the bovine model. Bovine species provide a valuable model due to their accessibility from slaughterhouse tissues, offering a practical alternative to human samples, which are often limited in availability. Additionally, bovine tissue closely mirrors certain physiological and biological characteristics of humans, making it a relevant model for translational research. Our findings revealed that these dECMs exhibited high biocompatibility with embryo development and cell viability, supporting micro vascularization and cellular morphology without the need for external growth factors. It is important to note that the addition of alginate was crucial for maintaining the structural integrity of the hydrogel during long-term cultures. These hydrogels displayed biomechanical properties that closely mimicked native tissues, which was vital for maintaining their functional integrity and supporting cellular activities. The printability assessments showed that dECMs, particularly those from cortex tissues, achieved high precision in replicating the intended structures, though challenges such as low porosity remained. The bioprinted constructs demonstrated robust cell growth, with over 97% viability observed by day 7, indicating their suitability for cell culture. This work represented a significant advancement in reproductive tissue biofabrication, demonstrating the potential of dECM-based hydrogels in creating structurally and viable tissue constructs. By tailoring each dECM to match the unique biomechanical properties of different tissues, we paved the way for more effective and reliable applications in reproductive medicine and tissue engineering