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Biomechanical effects of saddle height changes in leisure cycling with unilateral transtibial prostheses: A simulated study
Cycling is a beneficial physical activity for rehabilitating individuals with lower-limb amputations and serves as a feasible leisure sport. However, the optimal bicycle configuration for cycling with a unilateral transtibial prosthesis at leisure levels has not been investigated. For saddle height at professional cycling levels, existing literature suggests utilizing the same configuration as that used by intact cyclists, where the knee reaches 25–35° at maximum extension. However, leisure cyclists tend to select lower saddle heights, and cycling with a unilateral transtibial prosthesis infers altered biomechanics during cycling practice. This study aimed to investigate the effects of cycling at different saddle heights with a simulated unilateral prosthesis. Ten able-bodied participants wore orthoses to simulate prosthetic conditions. The experimental task was performed on an ergometer at 40 W resistance, 60 rpm to simulate leisure cycling. Standard saddle height was defined as maximum knee extension of 45°. This height was used as the control condition and its trials were performed without orthoses. The variable heights were set as height percentage variations (-7%, -3.5%, 0, +3.5%, and +7%). Muscle activity, joint movement, force application to the pedals, perceived exertion, and comfort were evaluated. The -3.5% and -7% saddle heights resulted in joint movement and muscle activity levels closer to those in the control conditions, which also showed improved power symmetry between the affected and non-affected legs. In addition, the -3.5% height increased comfort level in participants. In conclusion, selecting lower saddle heights may be beneficial for unilateral transtibial amputees during leisure cycling. The optimal saddle height for this population may maintain maximum knee extension within the 37–45° range, dynamically measured on the affected side.
Tamsulosin ameliorates bone loss by inhibiting the release of Cl <sup>−</sup> through wedging into an allosteric site of TMEM16A
TMEM16A, a key calcium-activated chloride channel, is crucial for many physiological and pathological processes such as cancer, hypertension, and osteoporosis, etc. However, the regulatory mechanism of TMEM16A is poorly understood, limiting the discovery of effective modulators. Here, we unveil an allosteric gating mechanism by presenting a high-resolution cryo-EM structure of TMEM16A in complex with a channel inhibitor that we identified, Tamsulosin, which is resolved at 2.93 Å. Tamsulosin wedges itself into a pocket within the extracellular domain of TMEM16A, surrounded by α1-α2, α5-α6, and α9-α10 loops. This binding stabilizes a transient preopen conformation of TMEM16A, which is activated by Ca 2+ ions while still preserving a closed pore to prevent Cl − permeation. Validation of this binding site through computational, electrophysiological, and functional experiments, along with site-directed mutagenesis, confirmed the pivotal roles of the pocket-lining residues R605 and E624 on α5-α6 loop in modulating Tamsulosin binding and pore activity. Tamsulosin induces significant positional shifts in extracellular loops, particularly the α5-α6 loop, which moves toward the extracellular exit of the pore, leading to noticeable structural rearrangements in pore-lining helices. The hinges induced by P595 in α5 and G711 in α7 introduce flexibility to the transmembrane helices, orienting Y593 to collaborate with I641 in effectively gating the preopening pore. Notably, Tamsulosin demonstrates significant antiosteoporotic effects by inhibiting TMEM16A, suggesting potential for its repurposing in new therapeutic indications. Our study not only enhances our understanding of the gating mechanism of TMEM16A inhibition but also facilitates structure-based drug design targeting TMEM16A.
Supervised pulmonary tele-rehabilitation and individualized home-based pulmonary rehabilitation for patients with COPD, unable to participate in center-based programs. The protocol for a multicenter randomized controlled trial - the REPORT study
Introduction Chronic obstructive pulmonary disease (COPD) costs EURO 1.4 billion annually in healthcare costs. Pulmonary rehabilitation (PR) is a vital aspect of care for patients with COPD, but despite the compelling evidence, it is delivered to less than 30%. Frequent transport to the center-based program is regularly reported as reasons for non-attendance. The effectiveness and feasibility of pulmonary tele-rehabilitation (PTR) and home-based pulmonary rehabilitation (HPR) have never been investigated in patients with COPD who are unable to attend conventional outpatient PR. Materials and methods This study is a multicenter randomized controlled trial consisting of three parallel groups; PTR, HPR and a control group. 180 patients with moderate to very severe COPD, who are unable to attend in center-based PR programs will be included. The PTR group receives group-based resistance- and endurance training and patient education 60 min. twice a week for 10-weeks. HPR comprises an individual self-initiated home-based PR program with online motivational and professional counseling. The goal is to achieve at least 20 min. of muscle-endurance based exercises three days weekly for 10-weeks. The PTR and HPR group use a tablet with a conference system. The control group receives usual care (no PR). After completion of the intervention, the PTR and HPR groups are offered 65-weeks groupbased maintance program supervised once a week online via tablet. The primary outcome is change in respiratory symptoms measured with the COPD Assessment Test after 10-weeks (primary endpoint). Discussion The study aims to test a possible equivalence between PTR and HPR and their superiority to controls on respiratory symptoms. The study will provide valuable insights into the effectiveness of new rehabilitation models and maintenance programs for patients with COPD. If the two new delivery models can reduce respiratory symptoms, patients with moderate to very severe COPD can participate in both home- or centerbased PR. Trial registration The trial is registrered and approved by the Ethics Committee of The Capital Region of Denmark (H-22015777; 29.08.2022) and the Danish Data Protection Agency (P-2022-245-13101, 25.05.2022). The trial is registrered at ClinicalTrials.gov, identifier: NCT05664945 (23.12.2022).
Nucleation mechanism of multiple-order parameter ferroelectric domain wall motion in hafnia
Ferroelectric hafnia exhibits promising robust polarization and silicon compatibility for ferroelectric devices. Unfortunately, it suffers from difficult polarization switching. Methods to enable easier polarization switching are needed, and the underlying reason for this switching difficulty is not understood. Here, we investigated the 180 ° domain walls of hafnia and their motion through nucleation. We found that the domains of multiple-order parameter hafnia possess complicated three-dimensional dipole patterns and lead to domain walls of different symmetry. The most common domain wall type is a complex domain wall involving reversal of both polarization and tetragonality order parameters. This domain wall symmetry ensures a good matching of the dipoles perpendicular to the domain wall, which leads to low domain wall energy. However, this ensures a sharp, high-energy, charged domain wall on the edges of nuclei that results in difficult nucleation. Thus, this domain wall is too stable to move, which explains the switching difficulty of hafnia. By contrast, another simple domain wall, involving only polarization reversal, has a poor matching of dipoles perpendicular to the domain wall. This leads to higher domain wall energy and ensures a diffusive and low-energy charged domain wall that enables easier nucleation. This simple domain wall is thus not too stable and easier to move. Our theory advances domain wall nucleation theory from the field of conventional single-order parameter to multiple-order parameters. We propose controlling the populations of different domain wall types in hafnia as a way to enable fast polarization switching and lower coercive fields.
Practices and preferences in the use of magnification among endodontists and restorative dentists: A multicentre study
Background and objectives Aim of the current study was to assess the perception, preference, and practice of endodontists and restorative dentists at different locations around the world about dental magnification instruments. Materials and methods A multicenter, cross-sectional study was ethically approved from the local committee of bioethics. After thorough literature search, a questionnaire was designed and validated. Later, the questionnaire was distributed to 10% (53 participants) of the total planned participants to conduct a pilot study. Based on the feedback from these participants, any ambiguities or discrepancies observed in the items and content of the questionnaire was modified. The questionnaire was assessed for its internal consistency as part of validating the items with Cronbach’s alpha of 0.80. The completed questionnaire with an informed consent form for the participant was administered to the endodontists and restorative dentists in three different geographical regions namely MENA (Middle East and Northern Africa), British-Isles, and Indian Sub-continent using WhatsApp through the snowball convenience sampling technique. Results Majority of the participants were male (56.5%) and in the age group of 25–35 years (30.3%). About 68.9% were from Indian sub-continent, followed by the British-Isles (16.5%) and the least (14.6%) were from the MENA region. By large, the participants of the present study, strongly agreed that dental magnification devices improved ergonomics, quality of work, and should be considered as standard of care in modern endodontic. Flip-up magnifiers (51.1%) and medium (8x-16x) magnification were preferred by majority of the participants. About 46.3% of specialist reported that they always used devices for all operative and endodontic procedures, especially while locating hidden and canals and negotiating calcified canals. Participants practicing in British-Isles have 2.42 times (P<0.05) higher adequate perception with reference participants in Indian sub-continent. Additionally, participants with fellowship have 2.77 times more (P<0.01) adequate perception with reference to their counterparts with a master’s degree. Conclusions Most of the participants believe that dental magnification devices enhance the prognosis and quality of treatment of possibly all operative and endodontics procedures. Thus, emphasized on the inclusion of devices in the postgraduate curriculum and signifies the role of continuing dental education for specialist and dental assistant handling devices. However, multicenter studies with larger sample is required for generalizing the results.
Structures of methane and ammonia monooxygenases in native membranes
Methane- and ammonia-oxidizing bacteria play key roles in the global carbon and nitrogen cycles, respectively. These bacteria use homologous copper membrane monooxygenases to accomplish the defining chemical transformations of their metabolisms: the oxidations of methane to methanol by particulate methane monooxygenase (pMMO) and ammonia to hydroxylamine by ammonia monooxygenase (AMO), enzymes of prime interest for applications in mitigating climate change. However, investigations of these enzymes have been hindered by the need for disruptive detergent solubilization prior to structure determination, confounding studies of pMMO and precluding studies of AMO. Here, we overcome these challenges by using cryoEM to visualize pMMO and AMO directly in their native membrane arrays at 2.4 to 2.8 Å resolution. These structures reveal details of the copper centers, numerous bound lipids, and previously unobserved components, including identifiable and distinct supernumerary helices interacting with pMMO and AMO, suggesting a widespread role for these helices in copper membrane monooxygenases. Comparisons between these structures, their metallocofactors, and their unexpected protein–protein interactions highlight features that may govern activity or the formation of higher-order arrays in native membranes. The ability to obtain molecular insights within the native membrane will enable further understanding of these environmentally important enzymes.
Research protocol for a systematic review and meta-analysis of the effects of music on anxiety and physiological outcomes in patients undergoing bronchoscopy
Introduction Bronchoscopy is a routine clinical examination that can cause discomfort and anxiety in patients. This paper presents a protocol for a systematic review and meta-analysis aiming to assess the effect of music on anxiety and physiological outcomes in patients undergoing bronchoscopy. Methods The protocol adhere to Preferred Reporting Items for Systematic Reviews and Meta-Analyses Protocols guidelines and has been registered in PROSPERO (CRD42024567398). Our documentary research strategy will involve four databases: PubMed, Google Scholar, Scopus, and the Cochrane Library. In addition, manual searches will be conducted through related articles and references. We will include randomized controlled trials that evaluate the effect of music on patients undergoing bronchoscopy. The primary outcome will be the anxiety level and the secondary outcome will include physiological outcomes. Study selection, data extraction, and quality assessment will be carried out independently by two reviewers. Any discrepancies will be resolved through consultation with a third reviewer. The quality and the risk of bias in the studies will be evaluated using The Joanna Briggs Institute critical appraisal tool. The results of this systematic review will be synthesized to provide an overview on the effectiveness of music on anxiety and physiological parameters in patients during bronchoscopy. If the results are considered acceptable and sufficiently homogeneous, a meta-analysis will be performed to synthesize the findings. Conclusion The systematic review produced from this protocol will provide evidence on the effectiveness of music for patients undergoing bronchoscopy and will contribute to strengthening the existing body of knowledge on non-pharmacological interventions for anxiety management during medical procedures.
The CYLD–PARP1 feedback loop regulates DNA damage repair and chemosensitivity in breast cancer cells
Poly(ADP-ribose) polymerase 1 (PARP1) plays a crucial role in DNA repair and genomic stability maintenance. However, the regulatory mechanisms governing PARP1 activity, particularly through deubiquitination, remain poorly elucidated. Using a deubiquitinase (DUB) library binding screen, we identified cylindromatosis (CYLD) as a bona fide DUB for PARP1 in breast cancer cells. Mechanistically, CYLD is recruited by PARP1 to DNA lesions upon genotoxic stress, where it cleaves K63-linked polyubiquitin chains on PARP1 at residues K748, K940, and K949, resulting in compromised PARP1 activation. In a reciprocal manner, PARP1 PARylates CYLD at sites E191, E231, E259, and E509, thereby enhancing its DUB activity. Consequently, depletion of CYLD leads to increased efficiency in base excision repair and confers breast cancer cells with resistance to alkylating agents. Conversely, overexpression of CYLD enhances sensitivity to PARP inhibitors (PARPi) even in homologous recombination-proficient breast cancer cells. These findings offer unique insights into the intricate interplay between CYLD and PARP1 in DNA repair, underscoring the pivotal role of targeting this regulatory axis for breast cancer chemotherapy.
Novel deep neural network architecture fusion to simultaneously predict short-term and long-term energy consumption
Energy is integral to the socio-economic development of every country. This development leads to a rapid increase in the demand for energy consumption. However, due to the constraints and costs associated with energy generation resources, it has become crucial for both energy generation companies and consumers to predict energy consumption well in advance. Forecasting energy needs through accurate predictions enables companies and customers to make informed decisions, enhancing the efficiency of both energy generation and consumption. In this context, energy generation companies and consumers seek a model capable of forecasting energy consumption both in the short term and the long term. Traditional models for energy prediction focus on either short-term or long-term accuracy, often failing to optimize both simultaneously. Therefore, this research proposes a novel hybrid model employing Convolutional Neural Network (CNN), Long Short-Term Memory (LSTM), and Bi-directional LSTM (Bi-LSTM) to simultaneously predict both short-term and long-term residential energy consumption with enhanced accuracy measures. The proposed model is capable of capturing complex temporal and spatial features to predict short-term and long-term energy consumption. CNNs discover patterns in data, LSTM identifies long-term dependencies and sequential patterns and Bi-LSTM identifies complex temporal relations within the data. Experimental evaluations expressed that the proposed model outperformed with a minimum Mean Square Error (MSE) of 0.00035 and Mean Absolute Error (MAE) of 0.0057. Additionally, the proposed hybrid model is compared with existing state-of-the-art models, demonstrating its superior performance in both short-term and long-term energy consumption predictions.
RAP-2 and CNH-MAP4 Kinase MIG-15 confer resistance in bystander epithelium to cell-fate transformation by excess Ras or Notch activity
Induction of cell fates by growth factors impacts many facets of developmental biology and disease. LIN-3/EGF induces the equipotent vulval precursor cells (VPCs) in Caenorhabditis elegans to assume the 3˚−3˚−2˚−1˚−2˚−3˚ pattern of cell fates. 1˚ and 2˚ cells become specialized epithelia and undergo stereotyped series of cell divisions to form the vulva. Conversely, 3˚ cells are relatively quiescent and nonspecialized; they divide once and fuse with the surrounding epithelium. 3˚ cells have thus been characterized as passive, uninduced, or ground state. Based on our previous studies, we hypothesized that a 3˚-promoting program would confer resistance to cell fate-transformation by inappropriately activated 1˚ and 2˚ fate-promoting LET-60/Ras and LIN-12/Notch, respectively. Deficient MIG-15/CNH-MAP4 Kinase meets the expectations of genetic interactions for a 3˚-promoting protein. Moreover, endogenous MIG-15 is required for expression of a fluorescent biomarker of 3˚ cell fate, is expressed in VPCs, and functions cell autonomously in VPCs. The Ras family small GTPase RAP-2, orthologs of which activate orthologs of MIG-15 in other systems, emulates these functions of MIG-15. However, gain of RAP-2 function has no effect on patterning, suggesting its activity is constitutive in VPCs. The 3˚ biomarker is expressed independently of the AC, raising questions about the cellular origin of 3˚-promoting activity. Activated LET-60/Ras and LIN-12/Notch repress expression of the 3˚ biomarker, suggesting that the 3˚-promoting program is both antagonized by as well as antagonizes 1˚- and 2˚- promoting programs. This study provides insight into developmental properties of cells historically considered to be nonresponding to growth factor signals.
An interpretable machine learning model for predicting in-hospital mortality in ICU patients with ventilator-associated pneumonia
Background Ventilator-associated pneumonia (VAP) is a common nosocomial infection in ICU, significantly associated with poor outcomes. However, there is currently a lack of reliable and interpretable tools for assessing the risk of in-hospital mortality in VAP patients. This study aims to develop an interpretable machine learning (ML) prediction model to enhance the assessment of in-hospital mortality risk in VAP patients. Methods This study extracted VAP patient data from versions 2.2 and 3.1 of the MIMIC-IV database, using version 2.2 for model training and validation, and version 3.1 for external testing. Feature selection was conducted using the Boruta algorithm, and 14 ML models were constructed. The optimal model was identified based on the area under the receiver operating characteristic curve (AUROC), accuracy, sensitivity, and specificity across both validation and test cohorts. SHapley Additive exPlanations (SHAP) analysis was applied for global and local interpretability. Results A total of 1,894 VAP patients were included, with 12 features ultimately selected for model construction: 24-hour urine output, blood urea nitrogen, age, diastolic blood pressure, platelet count, anion gap, body temperature, bicarbonate level, sodium level, body mass index, and whether combined with congestive heart failure and cerebrovascular disease. The random forest (RF) model showed the best performance, achieving an AUC of 0.780 in internal validation and 0.724 in external testing, outperforming other ML models and common clinical scoring systems. Conclusion The RF model demonstrated robust and reliable performance in predicting in-hospital mortality risk for VAP patients. The developed online tool can assist clinicians in efficiently assessing VAP in-hospital mortality risk, supporting clinical decision-making.
Elucidation of a distinct photoreduction pathway in class II <i>Arabidopsis thaliana</i> photolyase
Class II photolyases (PLs) are a distant subclade in the photolyase/cryptochrome superfamily, displaying a unique Trp–Tyr tetrad for photoreduction and exhibiting a lower quantum yield (QY) of DNA repair (49%) than class I photolyases (82%) [M. Zhang, L. Wang, S. Shu, A. Sancar, D. Zhong, Science 354 , 209–213 (2016)]. Using layer-by-layer mutant design and femtosecond spectroscopy, we have successfully determined the rates of electron transfer and proton transfer, driving force, and reorganization energy for nine elementary steps involved in the initial photoreduction of class II Arabidopsis thaliana photolyase (AtPL), thereby constructing the photoreduction network specific to class II PLs. Several dynamic features have been revealed including a slow-rise (172 ps) and fast-decay (26 ps) kinetics between the excited lumiflavin and adenine groups within the flavin adenine dinucleotide cofactor, a slower electron transfer (ET) (22 ps) between the excited lumiflavin and the nearest Trp in the Trp triad (W a ) as compared to reported class I PL (0.8 ps), and a rapid deprotonation of the distal Trp in the Trp triad (W c ). Most strikingly, we captured a slightly energetically unfavorable ET step between W a and the center Trp (W b ), as opposed to the decreasing reduction potential observed in class I PL that drives the electron flow unidirectionally. Such an energetically uphill ET step leads to a lower photoreduction quantum yield (~34%) in class II AtPL compared to that of class I PL (~45%), raising an important question on the evolutionary implications of various photoreduction networks in photolyases and cryptochromes.
Perceptions of access to harm reduction services during the COVID-19 pandemic among people who inject drugs in metropolitan Chicago
Background The COVID-19 pandemic amplified the risk environment for people who inject drugs (PWID), making continued access to harm reduction services imperative. Research has shown that some harm reduction service providers were able to continue to provide services throughout the pandemic. Most of these studies, however, focused on staff perspectives, not those of PWID. Our study examines changes in perceptions of access to harm reduction services (e.g., participant reported difficulty in accessing syringes and naloxone) among PWID participating in a longitudinal study conducted through the University of Illinois-Chicago’s Community Outreach Intervention Projects field sites during the COVID-19 pandemic. Methods A COIVD-19 survey module was administered from March 2020-February 2022 to participants of an ongoing longitudinal study of PWID ages 18–30, who were English-speaking, and were residing in the Chicago Metropolitan Area. Responses to the COVID-19 survey module were analyzed to understand how study participants’ self-reported access to harm reduction services changed throughout the pandemic. Baseline responses to the survey were analyzed to compare participant-reported drug use behaviors and perceived access to harm reduction services across COIVD-19 time periods. Mixed effects logistic regression was used to examine difficulty in syringe access as an outcome of COVID-19 time period. Results Participants had significantly lower odds (AOR = 0.28; 95% CI 0.12–0.65) of reporting difficulty in accessing syringes later in the pandemic. However, the majority of participants reported access to syringes and naloxone remained the same as before the pandemic. Conclusions The lack of perceived changes in harm reduction access by PWID and the decrease in those reporting difficulty accessing syringes as the pandemic progressed suggests the efficacy of adaptations to harm reduction service provision (e.g., window and mobile service) during the pandemic. Further research is needed to understand how the COVID-19 pandemic may have impacted PWIDs’ engagement with harm reduction services.
Higher-order transient membrane protein structures
This study shows that five membrane proteins—three GPCRs, an ion channel, and an enzyme—form self-clusters under natural expression levels in a cardiac-derived cell line. The cluster size distributions imply that these proteins self-oligomerize reversibly through weak interactions. When the concentration of the proteins is increased through heterologous expression, the cluster size distributions approach a critical distribution at which point a phase transition occurs, yielding larger bulk phase clusters. A thermodynamic model like that explaining micellization of amphiphiles and lipid membrane formation accounts for this behavior. We propose that many membrane proteins exist as oligomers that form through weak interactions, which we call higher-order transient structures (HOTS). The key characteristics of HOTS are transience, molecular specificity, and a monotonically decreasing size distribution that may become critical at high concentrations. Because molecular specificity invokes self-recognition through protein sequence and structure, we propose that HOTS are genetically encoded supramolecular units.
Barriers and enablers to opioid deprescription: A qualitative study
Background Canada has the fourth highest per capita rate of opioid prescriptions in the world, contributing to the country’s opioid crisis. Due to both their pain-relieving and euphoric properties, opioids can be highly addictive, leading to potential overdose and death. Deprescription is an endorsed and organized method of discontinuing a drug but very little is known about the barriers that Canadian physicians face when attempting to deprescribe opioids, particularly those who practice in rural areas (which have some of the highest rates of opioid users). Methods This was an explorative, qualitative study describing rural family doctors’ experiences and practices regarding opioid deprescription in primary care. A convenience sample of family doctors who had experience working with patients taking opioid medications was recruited from the professional networks of study team members. After consenting to participate, data was collected using semi-structured telephone interviews and analyzed by researchers experienced in applying the Theoretical Domains Framework to assess barriers and enablers of behavior change. Principal findings 10 physicians participated in this study. Our analysis revealed four barriers and five enablers related to opioid deprescription in rural primary care. Barriers include a lack of knowledge and skills related to deprescribing, discomfort initiating deprescription, patient pressure to continue prescribing opioids, and a lack of foundational support required to deprescribe. Enablers include working with colleagues who share common views on overuse of opioids and deprescription; access to other healthcare providers, community-based resources, and clinical tools; using a systematic approach to deprescription; previous experience successfully deprescribing opioids; and practicing in a rural setting. Conclusions Opioid dependence and over-prescription continue to be a problem for our health system. Deprescription is necessary but challenging for family physicians. Rural physicians are keenly aware of the importance of preserving the physician-patient therapeutic relationship and open and clear communication about opioid medications and deprescription but feel unprepared to manage this in the face of difficult issues surrounding deprescription. They also feel unprepared to deal with deprescription effectively without access to other resources, healthcare professionals, patient education materials and time. Rural physicians would benefit most from added foundational supports for deprescription.
Predicting gene sequences with AI to study codon usage patterns
Selective pressure acts on the codon use, optimizing multiple, overlapping signals that are only partially understood. We trained AI models to predict codons given their amino acid sequence in the eukaryotes Saccharomyces cerevisiae and Schizosaccharomyces pombe and the bacteria Escherichia coli and Bacillus subtilis to study the extent to which we can learn patterns in naturally occurring codons to improve predictions. We trained our models on a subset of the proteins and evaluated their predictions on large, separate sets of proteins of varying lengths and expression levels. Our models significantly outperformed naïve frequency-based approaches, demonstrating that there are learnable dependencies in evolutionary-selected codon usage. The prediction accuracy advantage of our models is greater for highly expressed genes and is greater in bacteria than eukaryotes, supporting the hypothesis that there is a monotonic relationship between selective pressure for complex codon patterns and effective population size. In S . cerevisiae and bacteria, our models were more accurate for longer proteins, suggesting that the learned patterns may be related to cotranslational folding. Gene functionality and conservation were also important determinants that affect the performance of our models. Finally, we showed that using information encoded in homologous proteins has only a minor effect on prediction accuracy, perhaps due to complex codon-usage codes in genes undergoing rapid evolution. Our study employing contemporary AI methods offers a unique perspective and a deep-learning-based prediction tool for evolutionary-selected codons. We hope that these can be useful to optimize codon usage in endogenous and heterologous proteins.
APOE4 and infectious diseases jointly contribute to brain glucose hypometabolism, a biomarker of Alzheimer’s pathology: New findings from the ADNI
Background Impaired brain glucose metabolism is a preclinical feature of neurodegenerative diseases such as Alzheimer’s disease (AD). Infections may promote AD-related pathology. Therefore, we investigated the interplay between infections and APOE4, a strong genetic risk factor for AD. Methods We analyzed data on 1,509 participants in the Alzheimer’s Disease Neuroimaging Initiative (ADNI) database using multivariate linear regression models. The outcomes were rank-normalized hypometabolic convergence index (HCI), statistical regions of interest (SROI) for AD, and mild cognitive impairment (MCI). Marginal mean estimates for infections, stratified by APOE4 carrier status, were then computed. Results Prior infections were associated with greater HCI [β = 0.15, 95% CI: 0.03, 0.27, p = 0.01]. The combined effects of infections and APOE4 carriers on HCI levels were significantly greater than either variable alone. Among APOE4 carriers, the estimated marginal mean was 0.62, rising to 0.77, with infections (p<0.001), indicating an interaction effect. Carriers with multiple infections showed greater hypometabolism (higher HCI), with an estimate of 0.44 (p = 0.01) compared to 0.11 (p = 0.08) for those with a single infection, revealing a dose-response relationship. The estimates for the association of infections with SROI AD and SROI MCI were β = -0.01 (p = 0.02) and β = -0.01 (p = 0.04), respectively. Conclusion Our findings suggest that infections and APOE4 jointly contribute to brain glucose hypometabolism and AD pathology, supporting a “multi-hit” mechanism in AD development.
Topological confinement by a membrane anchor suppresses phase separation into protein aggregates: Implications for prion diseases
Protein misfolding and aggregation are a hallmark of various neurodegenerative disorders. However, the underlying mechanisms driving protein misfolding in the cellular context are incompletely understood. Here, we show that the two-dimensional confinement imposed by a membrane anchor stabilizes the native protein conformation and suppresses liquid–liquid phase separation (LLPS) and protein aggregation. Inherited prion diseases in humans and neurodegeneration in transgenic mice are linked to the expression of anchorless prion protein (PrP), suggesting that the C-terminal glycosylphosphatidylinositol (GPI) anchor of native PrP impedes spontaneous formation of neurotoxic and infectious PrP species. Combining unique in vitro and in vivo approaches, we demonstrate that anchoring to membranes prevents LLPS and spontaneous aggregation of PrP. Upon release from the membrane, PrP undergoes a conformational transition to detergent-insoluble aggregates. Our study demonstrates an essential role of the GPI anchor in preventing spontaneous misfolding of PrP C and provides a mechanistic basis for inherited prion diseases associated with anchorless PrP.
Deep learning-based differential gut flora for prediction of Parkinson’s
Background There had been extensive research on the role of the gut microbiota in human health and disease. Increasing evidence suggested that the gut-brain axis played a crucial role in Parkinson’s disease, with changes in the gut microbiota speculated to be involved in the pathogenesis of Parkinson’s disease or interfere with its treatment. However, studies utilizing deep learning methods to predict Parkinson’s disease through the gut microbiota were still limited. Therefore, the goal of this study was to develop an efficient and accurate prediction method based on deep learning by thoroughly analyzing gut microbiota data to achieve the diagnosis of Parkinson’s disease. Methods This study proposed a method for predicting Parkinson’s disease using differential gut microbiota, named the Parkinson Gut Prediction Method (PGPM). Initially, differential gut microbiota data were extracted from 39 Parkinson’s disease (PD) patients and their corresponding 39 healthy spouses. Subsequently, a preprocessing method called CRFS (combined ranking using random forest scores and principal component analysis contributions) was introduced for feature selection. Following this, the proposed LSIM (LSTM-penultimate to SVM Input Method) approach was utilized for classifying Parkinson’s patients. Finally, a soft voting mechanism was employed to predict Parkinson’s disease patients. Results The research results demonstrated that the Parkinson gut prediction method (PGPM), which utilized differential gut microbiota, performed excellently. The method achieved a mean accuracy (ACC) of 0.85, an area under the curve (AUC) of 0.92, and a receiver operating characteristic (ROC) score of 0.92. Conclusion In summary, this method demonstrated excellent performance in predicting Parkinson’s disease, allowing for more accurate predictions of Parkinson’s disease.