Comparison of performances between risk scores for predicting mortality at 30 days in patients with community acquired pneumonia.

BACKGROUND: Risk scores facilitate the assessment of mortality risk in patients with community-acquired pneumonia (CAP). Despite their utilities, there is a scarcity of evidence comparing the various RS simultaneously. This study aims to evaluate and compare multiple risk scores reported in the literature for predicting 30-day mortality in adult patients with CAP. METHODS: A retrospective cohort study on patients diagnosed with CAP was conducted across two hospitals in Colombia. The areas under receiver operating characteristic curves (ROC-curves) were calculated for the outcome of survival or death at 30 days using the scores obtained for each of the analyzed questionnaires. RESULTS: A total of 7454 potentially eligible patients were included, with 4350 in the final analysis, of whom 15.2% (662/4350) died within 30 days. The average age was 65.4 years (SD: 21.31), and 59.5% (2563/4350) were male. Chronic kidney disease was 3.7% (9.2% vs. 5.5%; p < 0.001) (OR: 1.85) higher in subjects who died compared to those who survived. Among the patients who died, 33.2% (220/662) presented septic shock compared to 7.3% (271/3688) of the patients who survived (p < 0.001). The best performances at 30 days were shown by the following scores: PSI, SMART-COP and CURB 65 scores with the areas under ROC-curves of 0.83 (95% CI: 0.8-0.85), 0.75 (95% CI: 0.66-0.83), and 0.73 (95% CI: 0.71-0.76), respectively. The RS with the lowest performance was SIRS with the area under ROC-curve of 0.53 (95% CI: 0.51-0.56). CONCLUSION: The PSI, SMART-COP and CURB 65, demonstrated the best diagnostic performances for predicting 30-day mortality in patients diagnosed with CAP. The burden of comorbidities and complications associated with CAP was higher in patients who died.

Exploring the link between inflammatory myopathies and cancer: A comprehensive retrospective analysis in a Colombian cohort.

BACKGROUND: This study investigates the association between inflammatory myopathies (IM), and their correlation with cancer. There are several potential causes behind the association of cancer and inflammatory myopathies. The positivity of specific antibodies for myositis plays a significant role. Our objective is to describe cancer and inflammatory myopathies in Colombia, focusing on demographics, clinical characteristics, and laboratory data. METHODS: We retrospectively analyzed 112 IM patients diagnosed at Fundación Valle del Lili in Cali, Colombia, the cases met the EULAR/ACR criteria. Data included demographics, clinical signs, laboratory findings, and malignancy. Malignancy associations were explored using logistic regression. The survival analysis was assessed using Kaplan-Meier curves and the Log-Rank test. RESULTS: Dermatomyositis was the most common subtype (45.5%), with a female predominance (66.1%). Cancer diagnosis occurred in 11.6% of cases, predominantly thyroid cancer. The median time from myopathy onset to cancer diagnosis was 11 months, with 75% of cases within the first year. Bivariate analysis indicated associations between cancer and age, Gottron's papules, digital ulcers, and heliotrope rash. However, multivariate analysis identified age as the only significant malignancy risk factor. Survival analysis showed better rates in younger patients. CONCLUSION: This study provides into the link between IM and cancer in the Colombian population. Thyroid cancer predominated, with a slightly higher proportion of female cancer diagnoses. Age emerged as a significant risk factor for malignancy. Understanding this association is crucial for early detection and improving patient outcomes related to IM-associated malignancies.

Absence of Pathogenic Mutations and Strong Association With HLA-DRB1*11:01 in Statin-Naïve Early-Onset Anti-HMGCR Necrotizing Myopathy.

BACKGROUND AND OBJECTIVES: Immune-mediated necrotizing myopathy (IMNM) caused by antibodies against 3-hydroxy-3-methylglutaryl coenzyme A reductase (HMGCR) is an inflammatory myopathy that has been epidemiologically correlated with previous statin exposure. We characterized in detail a series of 11 young statin-naïve patients experiencing a chronic disease course mimicking a limb-girdle muscular dystrophy. With the hypothesis that HMGCR upregulation may increase immunogenicity and trigger the production of autoantibodies, our aim was to expand pathophysiologic knowledge of this distinct phenotype. METHODS: Clinical and epidemiologic data, autoantibody titers, creatine kinase (CK) levels, response to treatment, muscle imaging, and muscle biopsies were assessed. HMGCR expression in patients' muscle was assessed by incubating sections of affected patients with purified anti-HMGCR+ serum. Whole-exome sequencing (WES) with a special focus on cholesterol biosynthesis-related genes and high-resolution human leukocyte antigen (HLA) typing were performed. RESULTS: Patients, aged 3-25 years and mostly female (90.9%), presented with subacute proximal weakness progressing over many years and high CK levels (>1,000 U/L). Diagnostic delay ranged from 3 to 27 years. WES did not reveal any pathogenic variants. HLA-DRB1*11:01 carrier frequency was 60%, a significantly higher proportion than in the control population. No upregulation or mislocalization of the enzyme in statin-exposed or statin-naïve anti-HMGCR+ patients was observed, compared with controls. DISCUSSION: WES of a cohort of patients with dystrophy-like anti-HMGCR IMNM did not reveal any common rare variants of any gene, including cholesterol biosynthesis-related genes. HLA analysis showed a strong association with HLA-DRB1*11:01, previously mostly described in statin-exposed adult patients; consequently, a common immunogenic predisposition should be suspected, irrespective of statin exposure. Moreover, we were unable to conclusively demonstrate muscle upregulation/mislocalization of HMGCR in IMNM, whether or not driven by statins.

The Approved Live-Attenuated Chikungunya Virus Vaccine (IXCHIQ®) Elicits Cross-Neutralizing Antibody Breadth Extending to Multiple Arthritogenic Alphaviruses Similar to the Antibody Breadth Following Natural Infection.

The first vaccine against chikungunya virus (CHIKV) was recently licensed in the U.S., Europe, and Canada (brand IXCHIQ®, referred to as VLA1553). Other pathogenic alphaviruses co-circulate with CHIKV and major questions remain regarding the potential of IXCHIQ to confer cross-protection for populations that are exposed to them. Here, we characterized the cross-neutralizing antibody (nAb) responses against heterotypic CHIKV and additional arthritogenic alphaviruses in individuals at one month, six months, and one year post-IXCHIQ vaccination. We characterized nAbs against CHIKV strains LR2006, 181/25, and a 2021 isolate from Tocantins, Brazil, as well as O'nyong-nyong virus (ONNV), Mayaro virus (MAYV), and Ross River virus (RRV). IXCHIQ elicited 100% seroconversion to each virus, with the exception of RRV at 83.3% seroconversion of vaccinees, and cross-neutralizing antibody potency decreased with increasing genetic distance from CHIKV. We compared vaccinee responses to cross-nAbs elicited by natural CHIKV infection in individuals living in the endemic setting of Puerto Rico at 8-9 years post-infection. These data suggest that IXCHIQ efficiently and potently elicits cross-nAb breadth that extends to related alphaviruses in a manner similar to natural CHIKV infection, which may have important implications for individuals that are susceptible to alphavirus co-circulation in regions of potential vaccine rollout.

Sexual dimorphism of colorectal cancer in humans and colorectal tumors in a murine model.

Introduction: In colorectal cancer, men exhibit a higher incidence than women, and there is a disturbance in the levels of sex steroids in serum in patients with this disease. Consistently, in animals, males have greater tumor growth than females in diverse models. Nevertheless, the role of sex steroids is not well established. For that, we analyzed the effect of the principal gonadal sex steroids in both sexes. We determined sex as a statistically risk factor for colorectal cancer with data obtained from GLOBOCAN database. Methods: To induce colorectal tumors, we used the gold standard chemical method of azoxymethane and dextran sulphate of sodium. To evaluate the role of sex steroids, we gonadectomized independent males and female animals, reconstituting and substituting them with 17ß estradiol and dihydrotestosterone. Finally, we determined, in vitro, the proliferation of a human cell line exposed to 17ß estradiol, testosterone, or dihydrotestosterone. Sex, as a risk factor for colorectal cancer, showed a statistically significant susceptibility of men over 50 years old. Results: In vivo, males develop a greater number of tumors and with a larger size than females. In males, orchiectomy prevents tumor growth, whereas in females, ovariectomy promotes the development of neoplasms. DHT acts as a protumoral agent in both sexes. 17ß estradiol reduces tumor growth in females but enhances it in males, showing a dimorphic effect. In vitro studies reveal that estradiol decreases the proliferation of the HCT-116 colon cancer cell line, while testosterone boosts proliferation in these cells. Interestingly, dihydrotestosterone does not influence proliferation.

Identification of a pathogenic mutation in ARPP21 in patients with amyotrophic lateral sclerosis.

BACKGROUND AND OBJECTIVE: Between 5% and 10% of amyotrophic lateral sclerosis (ALS) cases have a family history of the disease, 30% of which do not have an identifiable underlying genetic cause after a comprehensive study of the known ALS-related genes. Based on a significantly increased incidence of ALS in a small geographical region from Spain, the aim of this work was to identify novel ALS-related genes in ALS cases with negative genetic testing. METHODS: We detected an increased incidence of both sporadic and, especially, familial ALS cases in a small region from Spain compared with available demographic and epidemiological data. We performed whole genome sequencing in a group of 12 patients with ALS (5 of them familial) from this unique area. We expanded the study to include affected family members and additional cases from a wider surrounding region. RESULTS: We identified a shared missense mutation (c.1586C>T; p.Pro529Leu) in the cyclic AMP regulated phosphoprotein 21 (ARPP21) gene that encodes an RNA-binding protein, in a total of 10 patients with ALS from 7 unrelated families. No mutations were found in other ALS-causing genes. CONCLUSIONS: While previous studies have dismissed a causal role of ARPP21 in ALS, our results strongly support ARPP21 as a novel ALS-causing gene.

Exploring the Esterase Catalytic Activity of Minimalist Heptapeptide Amyloid Fibers.

This paper investigates the esterase activity of minimalist amyloid fibers composed of short seven-residue peptides, IHIHIHI (IH7) and IHIHIQI (IH7Q), with a particular focus on the role of the sixth residue position within the peptide sequence. Through computational simulations and analyses, we explore the molecular mechanisms underlying catalysis in these amyloid-based enzymes. Contrary to initial hypotheses, our study reveals that the twist angle of the fiber, and thus the catalytic site's environment, is not notably affected by the sixth residue. Instead, the sixth residue interacts with the p-nitrophenylacetate (pNPA) substrate, particularly through its -NO2 group, potentially enhancing catalysis. Quantum mechanics/molecular mechanics (QM/MM) simulations of the reaction mechanism suggest that the polarizing effect of glutamine enhances catalytic activity by forming a stabilizing network of hydrogen bonds with pNPA, leading to lower energy barriers and a more exergonic reaction. Our findings provide valuable insights into the intricate interplay between peptide sequence, structural arrangement, and catalytic function in amyloid-based enzymes, offering potentially valuable information for the design and optimization of biomimetic catalysts.

Prognostic Relevance of Preoperative Immune, Inflammatory, and Nutritional Biomarkers in Patients Undergoing Gastrectomy for Resectable Gastric Adenocarcinoma: An Observational Multicentre Study.

Background: The aim of this study was to evaluate different preoperative immune, inflammatory, and nutritional scores and their best cut-off values as predictors of poorer overall survival (OS) and disease-free survival (DFS) in patients who underwent curative gastric cancer resection. Methods: This was a retrospective observational multicentre study based on data of the Spanish EURECCA Esophagogastric Cancer Registry. Time-dependent Youden index and log-rank test were used to obtain the best cut-offs of 18 preoperative biomarkers for OS and DFS. An adjusted Cox model with variables selected by bootstrapping was used to identify the best preoperative biomarkers, which were also analysed for every TNM stage. Results: High neutrophil-to-lymphocyte ratio (NLR), high monocyte systemic inflammation index (moSII), and low prognostic nutritional index (PNI) were identified as independent predictors of poor outcome: NLR > 5.91 (HR:1.73; 95%CI [1.23-2.43]), moSII >2027.12 (HR:2.26; 95%CI [1.36-3.78]), and PNI >40.31 (HR:0.75; 95%CI [0.58-0.96]) for 5-year OS and NLR > 6.81 (HR:1.75; 95%CI [1.24-2.45]), moSII > 2027.12 (HR:2.46; 95%CI [1.49-4.04]), and PNI > 40.31 (HR:0.77; 95%CI [0.60,0.97]) for 5-year DFS. These outcomes were maintained in the whole cohort for NLR and moSII (p < 0.05) but not in stage II and for PNI in all tumoral stages. The associations of NLR-PNI and moSII-PNI were also a relevant prognostic factor for OS. Conclusions: High NLR, high moSII (for stages I and III), and low PNI (regardless of tumour stage) were the most promising preoperative biomarkers to predict poor OS and DFS in gastric cancer patients treated with curative intent.

Sexual dimorphism in colorectal cancer: molecular mechanisms and treatment strategies.

INTRODUCTION: Sexual dimorphism significantly influences cancer incidence and prognosis. Notably, females exhibit a lower risk and favorable prognosis for non-reproductive cancers compared to males, a pattern observable beyond the scope of risk behaviors such as alcohol consumption and smoking. Colorectal cancer, ranking third in global prevalence and second in mortality, disproportionately affects men. Sex steroid hormones, particularly estrogens and androgens, play crucial roles in cancer progression, considering epidemiological in vivo and in vitro, in general estrogens imparting a protective effect in females and androgens correlating with an increasing risk of colorectal cancer development. MAIN BODY: The hormonal impact on immune response is mediated by receptor interactions, resulting in heightened inflammation, modulation of NF-kB, and fostering an environment conducive to cancer progression and metastasis. These molecules also influence the enteric nervous system, that is a pivotal in neuromodulator release and intestinal neuron stimulation, also contributes to cancer development, as evidenced by nerve infiltration into tumors. Microbiota diversity further intersects with immune, hormonal, and neural mechanisms, influencing colorectal cancer dynamics. A comprehensive understanding of hormonal influences on colorectal cancer progression, coupled with the complex interplay between immune responses, microbiota diversity and neurotransmitter imbalances, underpins the development of more targeted and effective therapies. CONCLUSIONS: Estrogens mitigate colorectal cancer risk by modulating anti-tumor immune responses, enhancing microbial diversity, and curbing the pro-tumor actions of the sympathetic and enteric nervous systems. Conversely, androgens escalate tumor growth by dampening anti-tumor immune activity, reducing microbial diversity, and facilitating the release of tumor-promoting factors by the nervous system. These findings hold significant potential for the strategic purposing of drugs to fine-tune the extensive impacts of sex hormones within the tumor microenvironment, promising advancements in colorectal cancer therapies.

Isolation and Visualization of Plant Stress Granule-Associated Components via On-Beads Digestion and Co-localization Analysis.

Stress granules (SGs) are conserved cytoplasmic biomolecular condensates mainly formed by proteins and RNA molecules assembled by liquid-liquid phase separation. Isolation of SGs components has been a major challenge in the field due to the dynamic and transient nature of stress granule shells. Here, we describe the methodology for the isolation and visualization of SGs proteins from Arabidopsis thaliana plants using a scaffold component as the target. The protocol consists of the first immunoprecipitation of GFP-tagged scaffold protein, followed by an on-beads enzymatic digestion and previous mass spectrometry identification. Finally, the localization of selected SGs candidates is visualized in Nicotiana benthamiana mesophyll protoplasts.

Emerging variants, unique phenotypes, and transcriptomic signatures: an integrated study of COASY-associated diseases.

OBJECTIVE: COASY, the gene encoding the bifunctional enzyme CoA synthase, which catalyzes the last two reactions of cellular de novo coenzyme A (CoA) biosynthesis, has been linked to two exceedingly rare autosomal recessive disorders, such as COASY protein-associated neurodegeneration (CoPAN), a form of neurodegeneration with brain iron accumulation (NBIA), and pontocerebellar hypoplasia type 12 (PCH12). We aimed to expand the phenotypic spectrum and gain insights into the pathogenesis of COASY-related disorders. METHODS: Patients were identified through targeted or exome sequencing. To unravel the molecular mechanisms of disease, RNA sequencing, bioenergetic analysis, and quantification of critical proteins were performed on fibroblasts. RESULTS: We identified five new individuals harboring novel COASY variants. While one case exhibited classical CoPAN features, the others displayed atypical symptoms such as deafness, language and autism spectrum disorders, brain atrophy, and microcephaly. All patients experienced epilepsy, highlighting its potential frequency in COASY-related disorders. Fibroblast transcriptomic profiling unveiled dysregulated expression in genes associated with mitochondrial respiration, responses to oxidative stress, transmembrane transport, various cellular signaling pathways, and protein translation, modification, and trafficking. Bioenergetic analysis revealed impaired mitochondrial oxygen consumption in COASY fibroblasts. Despite comparable total CoA levels to control cells, the amounts of mitochondrial 4'-phosphopantetheinylated proteins were significantly reduced in COASY patients. INTERPRETATION: These results not only extend the clinical phenotype associated with COASY variants but also suggest a continuum between CoPAN and PCH12. The intricate interplay of altered cellular processes and signaling pathways provides valuable insights for further research into the pathogenesis of COASY-associated diseases.

Unraveling the Properties of Phage Display Fab Libraries and Their Use in the Selection of Gliadin-Specific Probes by Applying High-Throughput Nanopore Sequencing.

Directed evolution is a pivotal strategy for new antibody discovery, which allowed the generation of high-affinity Fabs against gliadin from two antibody libraries in our previous studies. One of the libraries was exclusively derived from celiac patients' mRNA (immune library) while the other was obtained through a protein engineering approach (semi-immune library). Recent advances in high-throughput DNA sequencing techniques are revolutionizing research across genomics, epigenomics, and transcriptomics. In the present work, an Oxford Nanopore in-lab sequencing device was used to comprehensively characterize the composition of the constructed libraries, both at the beginning and throughout the phage-mediated selection processes against gliadin. A customized analysis pipeline was used to select high-quality reads, annotate chain distribution, perform sequence analysis, and conduct statistical comparisons between the different selection rounds. Some immunological attributes of the most representative phage variants after the selection process were also determined. Sequencing results revealed the successful transfer of the celiac immune response features to the immune library and the antibodies derived from it, suggesting the crucial role of these features in guiding the selection of high-affinity recombinant Fabs against gliadin. In summary, high-throughput DNA sequencing has improved our understanding of the selection processes aimed at generating molecular binders against gliadin.

Application of Machine Learning Techniques for the Diagnosis of Obstructive Sleep Apnea/Hypopnea Syndrome.

Obstructive sleep apnea/hypopnea syndrome (OSAHS) is a condition linked to severe cardiovascular and neuropsychological consequences, characterized by recurrent episodes of partial or complete upper airway obstruction during sleep, leading to compromised ventilation, hypoxemia, and micro-arousals. Polysomnography (PSG) serves as the gold standard for confirming OSAHS, yet its extended duration, high cost, and limited availability pose significant challenges. In this paper, we employ a range of machine learning techniques, including Neural Networks, Decision Trees, Random Forests, and Extra Trees, for OSAHS diagnosis. This approach aims to achieve a diagnostic process that is not only more accessible but also more efficient. The dataset utilized in this study consists of records from 601 adults assessed between 2014 and 2016 at a specialized sleep medical center in Colombia. This research underscores the efficacy of ensemble methods, specifically Random Forests and Extra Trees, achieving an area under the Receiver Operating Characteristic (ROC) curve of 89.2% and 89.6%, respectively. Additionally, a web application has been devised, integrating the optimal model, empowering qualified medical practitioners to make informed decisions through patient registration, an input of 18 variables, and the utilization of the Random Forests model for OSAHS screening.

Exploring Gluten Assessment in Marketed Products through a Sandwich ELISA Methodology Based on Novel Recombinant Antibodies.

This study presents the development of a sandwich ELISA method for gluten detection in foods, using recombinant Fab antibody fragments against gliadin. The Fabs were chemically biotinylated and immobilized on streptavidin-coated plates as capture antibodies, while alkaline phosphatase-conjugated Fabs were used as detection antibodies. Four different gliadin-binding Fabs were tested and the Fab pair Fab8E-4 and Fab-C showed the best compatibility. An indirect sandwich immunoassay, using unmodified Fab8E-4 for capture and Fab-C as the detection antibody, achieved a detection limit of 26 ng/mL of gliadin, corresponding to 10 mg/kg of gluten in foods. No cross-reactivity was observed against 60 gluten-free species commonly used in the food industry. Analysis of 50 commercial products demonstrated consistent results compared to the standard method for gluten detection. The complete lack of cross-reactivity of the developed immunoassay with oat products potentially provides an advantage over other gluten detection systems.

Application of ecotoxicological tools to evaluate the quality status of mangroves under restoration in the Yucatán Peninsula, Mexico.

Ecotoxicological tools, namely biomarkers and bioassays, may provide insights on the ecological quality status of mangroves under restoration. We investigated how 1) physicochemical parameters and water bioassays using Artemia franciscana; and 2) quantification of sublethal (osmoregulatory capacity, biochemical, and oxidative stress) and individual biomarkers (density, length-weight relationship [LWR], parasitic prevalence) in the sentinel fiddler crab Minuca rapax, can improve restoration indicators in mangroves from the Yucatán Peninsula, Southern Gulf of Mexico. We showed that water quality was improved with restoration, but still presented toxicity. Regarding sublethal biomarkers, M rapax from restored areas lower osmotic regulatory capacity, higher oxidative stress, and showed lipid peroxidation. As to the individual biomarkers, the density, LWR, and the prevalence of parasites in M. rapax was higher in restored areas. The use of bioassays/biomarkers were useful as early warning indicators to better assess the health of mangroves under restoration.

Mitochondrial DNA: Inherent Complexities Relevant to Genetic Analyses.

Mitochondrial DNA (mtDNA) exhibits distinct characteristics distinguishing it from the nuclear genome, necessitating specific analytical methods in genetic studies. This comprehensive review explores the complex role of mtDNA in a variety of genetic studies, including genome-wide, epigenome-wide, and phenome-wide association studies, with a focus on its implications for human traits and diseases. Here, we discuss the structure and gene-encoding properties of mtDNA, along with the influence of environmental factors and epigenetic modifications on its function and variability. Particularly significant are the challenges posed by mtDNA's high mutation rate, heteroplasmy, and copy number variations, and their impact on disease susceptibility and population genetic analyses. The review also highlights recent advances in methodological approaches that enhance our understanding of mtDNA associations, advocating for refined genetic research techniques that accommodate its complexities. By providing a comprehensive overview of the intricacies of mtDNA, this paper underscores the need for an integrated approach to genetic studies that considers the unique properties of mitochondrial genetics. Our findings aim to inform future research and encourage the development of innovative methodologies to better interpret the broad implications of mtDNA in human health and disease.

Diagnosing Alzheimer's disease: Which dementia screening test to use in elderly Puerto Ricans with mild cognitive impairment and early Alzheimer's disease?

Typically, Alzheimer's disease (AD) diagnosis is not made at its earliest period, for instance, at mild cognitive impairment (MCI) and early AD (E-AD). Our study aims to demonstrate a correlation between the screening tools, including the Mini-Mental State Examination (MMSE), Montreal Cognitive Assessment (MoCA), and Clinical Dementia Rating (CDR), and the biological biomarkers in the cerebrospinal fluid (CSF) amyloid beta 1-42 (Aß42), phosphorylated tau (p-tau) proteins and total tau (t-tau)/Aß42 ratio in Puerto Ricans > 55 years old with MCI and E-AD. We evaluated 30 participants, including demographics, memory scales, and CSF biomarkers. Twenty-eight CSF biomarkers (Aß42, p-tau protein, and t-tau/Aß42 ratio) were analyzed using the Meso Scale Discovery Platform (MSD). Associations between memory scales (MoCA, MMSE, CDR) and CSF markers were performed using Spearman rho correlation. Our study revealed a statistical association favoring a direct relationship between MMSE and MoCA with t-tau/Aß42 ratio in CSF (P = 0.022, P = 0.035, respectively). We found a trend toward significance with an inverse relationship with MMSE and Aß42 (P = 0.069) and a direct relationship with MMSE and p-tau (P = 0.098). MMSE and MoCA screening tests were identified with a statistically significant association with the CSF biomarkers, specifically t-tau/Aß42 ratio, in elderly Puerto Ricans with MCI and E-AD. Puerto Ricans > 55 years old with MCI and E-AD could be screened confidently with MMSE and MoCA for a higher likelihood of earlier detection and, thus, initiation of disease-modifying treatment and prompt non-pharmacological interventions.

Comprehensive study reveals phenotypic heterogeneity in Klebsiella pneumoniae species complex isolates.

Here, we conducted a comprehensive analysis of 356 Klebsiella pneumoniae species complex (KpSC) isolates that were classified as classical (cl), presumptive hypervirulent (p-hv) and hypermucoviscous-like (hmv-like). Overall, K. pneumoniae (82.3%), K. variicola (2.5%) and K. quasipneumoniae (2.5%) were identified. These isolates comprised 321 cl-KpSC, 7 p-hv-KpSC and 18 hmv-like-KpSC. A large proportion of cl-KpSC isolates were extended-spectrum-ß-lactamases (ESBLs)-producers (64.4%) and 3.4% of isolates were colistin-resistant carrying carbapenemase and ESBL genes. All p-hv-KpSC showed an antibiotic susceptible phenotype and hmv-like isolates were found to be ESBL-producers (8/18). Assays for capsule production and capsule-dependent virulence phenotypes and whole-genome sequencing (WGS) were performed in a subset of isolates. Capsule amount differed in all p-hv strains and hmv-like produced higher capsule amounts than cl strains; these variations had important implications in phagocytosis and virulence. Murine sepsis model showed that most cl strains were nonlethal and the hmv-like caused 100% mortality with 3 × 108 CFUs. Unexpectedly, 3/7 (42.9%) of p-hv strains required 108 CFUs to cause 100% mortality (atypical hypervirulent), and 4/7 (57.1%) strains were considered truly hypervirulent (hv). Genomic analyses confirmed the diverse population, including isolates belonging to hv clonal groups (CG) CG23, CG86, CG380 and CG25 (this corresponded to the ST3999 a novel hv clone) and MDR clones such as CG258 and CG147 (ST392) among others. We noted that the hmv-like and hv-ST3999 isolates showed a close phylogenetic relationship with cl-MDR K. pneumoniae. The information collected here is important to understand the evolution of clinically important phenotypes such as hypervirulent and ESBL-producing-hypermucoviscous-like amongst the KpSC in Mexican healthcare settings. Likewise, this study shows that mgrB inactivation is the main mechanism of colistin resistance in K. pneumoniae isolates from Mexico.

Predicting major adverse cardiovascular events after orthotopic liver transplantation using a supervised machine learning model: A cohort study.

BACKGROUND: Liver transplant (LT) patients have become older and sicker. The rate of post-LT major adverse cardiovascular events (MACE) has increased, and this in turn raises 30-d post-LT mortality. Noninvasive cardiac stress testing loses accuracy when applied to pre-LT cirrhotic patients. AIM: To assess the feasibility and accuracy of a machine learning model used to predict post-LT MACE in a regional cohort. METHODS: This retrospective cohort study involved 575 LT patients from a Southern Brazilian academic center. We developed a predictive model for post-LT MACE (defined as a composite outcome of stroke, new-onset heart failure, severe arrhythmia, and myocardial infarction) using the extreme gradient boosting (XGBoost) machine learning model. We addressed missing data (below 20%) for relevant variables using the k-nearest neighbor imputation method, calculating the mean from the ten nearest neighbors for each case. The modeling dataset included 83 features, encompassing patient and laboratory data, cirrhosis complications, and pre-LT cardiac assessments. Model performance was assessed using the area under the receiver operating characteristic curve (AUROC). We also employed Shapley additive explanations (SHAP) to interpret feature impacts. The dataset was split into training (75%) and testing (25%) sets. Calibration was evaluated using the Brier score. We followed Transparent Reporting of a Multivariable Prediction Model for Individual Prognosis or Diagnosis guidelines for reporting. Scikit-learn and SHAP in Python 3 were used for all analyses. The supplementary material includes code for model development and a user-friendly online MACE prediction calculator. RESULTS: Of the 537 included patients, 23 (4.46%) developed in-hospital MACE, with a mean age at transplantation of 52.9 years. The majority, 66.1%, were male. The XGBoost model achieved an impressive AUROC of 0.89 during the training stage. This model exhibited accuracy, precision, recall, and F1-score values of 0.84, 0.85, 0.80, and 0.79, respectively. Calibration, as assessed by the Brier score, indicated excellent model calibration with a score of 0.07. Furthermore, SHAP values highlighted the significance of certain variables in predicting postoperative MACE, with negative noninvasive cardiac stress testing, use of nonselective beta-blockers, direct bilirubin levels, blood type O, and dynamic alterations on myocardial perfusion scintigraphy being the most influential factors at the cohort-wide level. These results highlight the predictive capability of our XGBoost model in assessing the risk of post-LT MACE, making it a valuable tool for clinical practice. CONCLUSION: Our study successfully assessed the feasibility and accuracy of the XGBoost machine learning model in predicting post-LT MACE, using both cardiovascular and hepatic variables. The model demonstrated impressive performance, aligning with literature findings, and exhibited excellent calibration. Notably, our cautious approach to prevent overfitting and data leakage suggests the stability of results when applied to prospective data, reinforcing the model's value as a reliable tool for predicting post-LT MACE in clinical practice.

Clinical practice guidelines for the diagnosis and management of Charcot-Marie-Tooth disease.

INTRODUCTION: Charcot-Marie-Tooth disease (CMT) is classified according to neurophysiological and histological findings, the inheritance pattern, and the underlying genetic defect. The objective of these guidelines is to offer recommendations for the diagnosis, prognosis, follow-up, and treatment of this disease in Spain. MATERIAL AND METHODS: These consensus guidelines were developed through collaboration by a multidisciplinary panel encompassing a broad group of experts on the subject, including neurologists, paediatric neurologists, geneticists, physiatrists, and orthopaedic surgeons. RECOMMENDATIONS: The diagnosis of CMT is clinical, with patients usually presenting a common or classical phenotype. Clinical assessment should be followed by an appropriate neurophysiological study; specific recommendations are established for the parameters that should be included. Genetic diagnosis should be approached sequentially; once PMP22 duplication has been ruled out, if appropriate, a next-generation sequencing study should be considered, taking into account the limitations of the available techniques. To date, no pharmacological disease-modifying treatment is available, but symptomatic management, guided by a multidiciplinary team, is important, as is proper rehabilitation and orthopaedic management. The latter should be initiated early to identify and improve the patient's functional deficits, and should include individualised exercise guidelines, orthotic adaptation, and assessment of conservative surgeries such as tendon transfer. The follow-up of patients with CMT is exclusively clinical, and ancillary testing is not necessary in routine clinical practice.