SARS-CoV-2 Infection Depends on Cellular Heparan Sulfate and ACE2.

We show that SARS-CoV-2 spike protein interacts with both cellular heparan sulfate and angiotensin-converting enzyme 2 (ACE2) through its receptor-binding domain (RBD). Docking studies suggest a heparin/heparan sulfate-binding site adjacent to the ACE2-binding site. Both ACE2 and heparin can bind independently to spike protein in vitro, and a ternary complex can be generated using heparin as a scaffold. Electron micrographs of spike protein suggests that heparin enhances the open conformation of the RBD that binds ACE2. On cells, spike protein binding depends on both heparan sulfate and ACE2. Unfractionated heparin, non-anticoagulant heparin, heparin lyases, and lung heparan sulfate potently block spike protein binding and/or infection by pseudotyped virus and authentic SARS-CoV-2 virus. We suggest a model in which viral attachment and infection involves heparan sulfate-dependent enhancement of binding to ACE2. Manipulation of heparan sulfate or inhibition of viral adhesion by exogenous heparin presents new therapeutic opportunities.

Neuronal Ndst1 depletion accelerates prion protein clearance and slows neurodegeneration in prion infection.

Select prion diseases are characterized by widespread cerebral plaque-like deposits of amyloid fibrils enriched in heparan sulfate (HS), a abundant extracellular matrix component. HS facilitates fibril formation in vitro, yet how HS impacts fibrillar plaque growth within the brain is unclear. Here we found that prion-bound HS chains are highly sulfated, and that the sulfation is essential for accelerating prion conversion in vitro. Using conditional knockout mice to deplete the HS sulfation enzyme, Ndst1 (N-deacetylase / N-sulfotransferase) from neurons or astrocytes, we investigated how reducing HS sulfation impacts survival and prion aggregate distribution during a prion infection. Neuronal Ndst1-depleted mice survived longer and showed fewer and smaller parenchymal plaques, shorter fibrils, and increased vascular amyloid, consistent with enhanced aggregate transit toward perivascular drainage channels. The prolonged survival was strain-dependent, affecting mice infected with extracellular, plaque-forming, but not membrane bound, prions. Live PET imaging revealed rapid clearance of recombinant prion protein monomers into the CSF of neuronal Ndst1- deficient mice, neuronal, further suggesting that HS sulfate groups hinder transit of extracellular prion protein monomers. Our results directly show how a host cofactor slows the spread of prion protein through the extracellular space and identify an enzyme to target to facilitate aggregate clearance.

Short-term outcomes of dogs and cats undergoing lung lobectomy using either a self-ligating loop or a thoracoabdominal stapler.

OBJECTIVE: To assess clinical outcomes of lung lobectomies in dogs and cats using either self-ligating loops (SLLs) or thoracoabdominal (TA) staplers, aiming to inform sample size calculations for future superiority trials. STUDY DESIGN: Retrospective study. ANIMALS: A total of 72 dogs and 15 cats. METHODS: Records from January 2003 to October 2023 at a single institution were reviewed. Cases with lung lobectomy performed via TA stapler or SLL with a minimum 14-day postoperative follow-up were included. Pre-, intra-, and postoperative data were collected, with outcomes of interest including the frequency of intra- and postoperative complications. Outcome comparisons between techniques were performed to inform sample size calculations. RESULTS: A total of 101 lung lobectomies were performed. The TA stapler was used in 83 (82.2%) and the SLL in 18 (17.8%) lung lobectomies. Intraoperative complications were identified in 14/101 lung lobectomies (13.9%), including intraoperative hemorrhage in 12/101 lobectomies (11.8%) and air leakage in 2/101 lobectomies (1.9%). Postoperative complications were identified in 12/87 cases (13.8%), including 4 (4.6%) catastrophic complications and 5 (5.8%) major complications. All intra- and postoperative complications occurred in cases having undergone stapled lung lobectomy; however, no differences were identified between surgical technique and either intraoperative (p = .069) or postoperative complications (p = .112). A sample size of 103 lobectomies per technique group would be required for appropriate evaluation. CONCLUSION: Lung lobectomy using either surgical technique provided a good short-term outcome in this population. CLINICAL SIGNIFICANCE: Self-ligating loop lung lobectomy provided a comparable alternative to stapled lung lobectomy. Further studies are needed to assess technique superiority.

Impaired mitophagy in Sanfilippo a mice causes hypertriglyceridemia and brown adipose tissue activation.

Lysosomal storage diseases result in various developmental and physiological complications, including cachexia. To study the causes for the negative energy balance associated with cachexia, we assessed the impact of sulfamidase deficiency and heparan sulfate storage on energy homeostasis and metabolism in a mouse model of type IIIa mucopolysaccharidosis (MPS IIIa, Sanfilippo A syndrome). At 12-weeks of age, MPS IIIa mice exhibited fasting and postprandial hypertriglyceridemia compared with wildtype mice, with a reduction of white and brown adipose tissues. Partitioning of dietary [3H]triolein showed a marked increase in intestinal uptake and secretion, whereas hepatic production and clearance of triglyceride-rich lipoproteins did not differ from wildtype controls. Uptake of dietary triolein was also elevated in brown adipose tissue (BAT), and notable increases in beige adipose tissue occurred, resulting in hyperthermia, hyperphagia, hyperdipsia, and increased energy expenditure. Furthermore, fasted MPS IIIa mice remained hyperthermic when subjected to low temperature but became cachexic and profoundly hypothermic when treated with a lipolytic inhibitor. We demonstrated that the reliance on increased lipid fueling of BAT was driven by a reduced ability to generate energy from stored lipids within the depot. These alterations arose from impaired autophagosome-lysosome fusion, resulting in increased mitochondria content in beige and BAT. Finally, we show that increased mitochondria content in BAT and postprandial dyslipidemia was partially reversed upon 5-week treatment with recombinant sulfamidase. We hypothesize that increased BAT activity and persistent increases in energy demand in MPS IIIa mice contribute to the negative energy balance observed in patients with MPS IIIa.

Dynamic Invasive Hemodynamic Congestion Profile Impacts Acute Myocardial Infarction Complicated by Cardiogenic Shock Outcomes: A Real-World Single-Center Study.

BACKGROUND: Cardiogenic shock (CS) commonly complicates the management of acute myocardial infarction (AMI), and it results in high mortality rates. Pulmonary artery catheter (PAC) monitoring can be valuable for personalizing critical-care interventions. We hypothesized that patients with AMI-CS experiencing persistent congestion measures during the first 24 hours of the PAC installment would exhibit worse in-hospital survival rates. METHODS AND RESULTS: We studied 295 patients with AMI-CS between January 2006 and December 2021. The first 24-hour PAC-derived hemodynamic measures were divided by the congestion profiling and the proposed 2022 Cardiovascular Angiography and Interventions (SCAI) classification. Biventricular congestion was the most common profile and was associated with the highest patient mortality rates at all time points (mean 56.6%). A persistent congestive profile was associated with increased mortality rates (hazard ratio [HR] = 1.85; P = 0.002) compared with patients who achieved decongestive profiles. Patients with SCAI stages D/E had higher levels of right atrial pressure (RAP): 14-15 mmHg) and pulmonary capillary wedge pressure (PCWP): 18-20 mmHg) compared with stage C (RAP, 10-11 mmHg, mean difference 3-5 mmHg; P < 0.001; PCWP 14-17 mmHg; mean difference 1.56-4 mmHg; P = 0.011). In SCAI stages D/E, the pulmonary artery pulsatility index (0.8-1.19) was lower than in those with grade C (1.29-1.63; mean difference 0.21-0.73; P < 0.001). CONCLUSIONS: Continuous congestion profiling using the SCAI classification matched the grade of hemodynamic severity and the increased risk of in-hospital death. Early decongestion appears to be an important prognostic and therapeutic goal in patients with AMI-CS and warrants further study.

Acute respiratory distress syndrome in patients with COVID-19 vs. Non-COVID-19: clinical characteristics and outcomes in a tertiary care setting in Mexico City.

BACKGROUND: Acute Respiratory Distress Syndrome (ARDS) due tocoronavirus disease (COVID-19) infection has a unique phenotype generating a growing need to determine the existing differences that can alter existing evidence-based management strategies for ARDS. RESEARCH QUESTION: What differences does the clinical profile of patients with ARDS due to COVID 19 and Non-COVID 19 have? STUDY DESIGN AND METHODS: We conducted a comparative, observational, retrospective study in the Intensive Care Unit (ICU)of a third-level hospital in Mexico City, from March 2020 through March 2022. Clinical, echocardiographic, and laboratory variables were compared between patients with ARDS due to Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) infection and those due to other etiologies. RESULTS: We enrolled 140 patients with a diagnosis of ARDS. The study group of COVID-19 etiology were younger males, higher body mass index, progressed to organ dysfunction, required more frequently renal replacement therapy, and higher SOFA score. There was no difference in rates of right ventricular dysfunction. INTERPRETATION: COVID-19 ARDS exhibit much greater severity that led to higher admission and mortality rates, whilst being younger and less comorbid.

Assessing the venous system: Correlation of mean systemic filling pressure with the venous excess ultrasound grading system in cardiac surgery.

BACKGROUND: Evaluation of the venous system has long been underestimated as an important component of the circulatory system. As systemic venous pressure increases, the perfusion pressure to the tissues is compromised. During initial resuscitation in cardiac surgery, excessive fluid administration is associated with increased morbidity and mortality. METHODS: We conducted a cross-sectional study of 60 consecutive adult patients who underwent cardiac surgery and in whom it was possible to obtain the venous excess ultrasound (VExUS) grading system and mean systemic filling pressure (Pmsf) in the postoperative period upon admission, at 24 and 48 h. We then determined the correlation between VExUS grading and Pmsf. RESULTS: On admission, patients with VExUS grading 0 predominated, with a progressive increase in venous congestion and an increase in Pmsf over the course of the first 48 h. There was a strong positive correlation between VExUS grading and the invasive measurement of Pmsf at 24 and 48 h after arrival. The presence of grade 2 or grade 3 venous congestion in the postoperative period poses an increased risk of developing acute kidney injury. CONCLUSION: The VExUS grading system indicates a high degree of systemic venous congestion in the first 48 h of the postoperative period after cardiac surgery and correlates with the Pmsf, which is the best surrogate of stressed circulatory volume.

A contrast echocardiography-based protocol to rule out thrombus in Venous-Arterial ECMO: A proof of concept.

Using an ultrasound-enhancing agent (UEA) has several indications, especially in diagnosing left ventricular thrombus. Herein, we present three cases of patients who were candidates for venous-arterial extracorporeal membrane oxygenation, among whom thrombus was ruled out via contrast echocardiography. The use of a UEA in these patients was a novel approach.

Hypertrophic cardiomyopathy in the systemic right ventricle in a patient with congenitally corrected transposition of the great arteries: A case report.

Congenitally corrected transposition of the great arteries is a rare clinical entity, which usually presents during adulthood with associated defects; atrioventricular block, heart failure, systemic valve failure, and arrhythmias usually complicate the clinical course. Even rarer is associated hypertrophic cardiomyopathy, which complicates the disease course and clinical decision-making. Herein, we present a patient with this condition who underwent heart transplantation, with adequate clinical resolution.

Pyridostigmine reduces mortality of patients with severe SARS-CoV-2 infection: A phase 2/3 randomized controlled trial.

BACKGROUND: Respiratory failure in severe coronavirus disease 2019 (COVID-19) is associated with a severe inflammatory response. Acetylcholine (ACh) reduces systemic inflammation in experimental bacterial and viral infections. Pyridostigmine increases the half-life of endogenous ACh, potentially reducing systemic inflammation. We aimed to determine if pyridostigmine decreases a composite outcome of invasive mechanical ventilation (IMV) and death in adult patients with severe COVID-19. METHODS: We performed a double-blinded, placebo-controlled, phase 2/3 randomized controlled trial of oral pyridostigmine (60 mg/day) or placebo as add-on therapy in adult patients admitted due to confirmed severe COVID-19 not requiring IMV at enrollment. The primary outcome was a composite of IMV or death by day 28. Secondary outcomes included reduction of inflammatory markers and circulating cytokines, and 90-day mortality. Adverse events (AEs) related to study treatment were documented and described. RESULTS: We recruited 188 participants (94 per group); 112 (59.6%) were men; the median (IQR) age was 52 (44-64) years. The study was terminated early due to a significant reduction in the primary outcome in the treatment arm and increased difficulty with recruitment. The primary outcome occurred in 22 (23.4%) participants in the placebo group vs. 11 (11.7%) in the pyridostigmine group (hazard ratio, 0.47, 95% confidence interval 0.24-0.9; P = 0.03). This effect was driven by a reduction in mortality (19 vs. 8 deaths, respectively). CONCLUSION: Our data indicate that adding pyridostigmine to standard care reduces mortality among patients hospitalized for severe COVID-19.

Renal Resistive Index as a Predictor of Acute Kidney Injury and Mortality in COVID-19 Critically Ill Patients.

BACKGROUND: Acute kidney injury (AKI) in patients with COVID-19 can be caused by multiple mechanisms. Renal resistive index (RRI) is a noninvasive instrument to evaluate kidney hemodynamics, and it is obtained by analysis of intrarenal arterial waves using Doppler ultrasound. This study aimed to determine the role of RRI in predicting AKI and adverse outcomes in critically ill patients with COVID-19. METHODS: This cross-sectional study included 65 patients with confirmed SARS-CoV-2 pneumonia admitted to the critical care unit from April 1, 2020, to June 20, 2020. Informed consent was obtained from all individual participants included in the study. Cardiac, pulmonary, and kidney ultrasonographic evaluations were performed in a protocolized way. RESULTS: In this cohort, 65 patients were included, mean age was 53.4 years, 79% were male, and 35% were diabetic. Thirty-four percent of patients developed AKI, 12% required RRT, and 35% died. Of the patients who developed AKI, 68% had RRI ≥ 0.7. Also, 75% of the patients who required RRT had RRI ≥ 0.7. In the adjusted Cox model, the RRI ≥ 0.7 was associated with higher mortality (HR 2.86, 95% CI: 1.19-6.82, p = 0.01). CONCLUSIONS: Critical care ultrasonography is a noninvasive, reproducible, and accurate bedside method that has proven its usefulness. An elevated RRI may have a role in predicting AKI, RRT initiation, and mortality in patients with severe SARS-CoV-2 pneumonia.

Correlation between transhepatic and subcostal inferior vena cava ultrasonographic images for evaluating fluid responsiveness after cardiac surgery.

BACKGROUND: Echocardiographic monitoring during the postoperative period following cardiac surgery is essential because patients often develop hemodynamic instability from hypovolemia and other causes. Therefore, predicting fluid responsiveness by measuring respirophasic variation in the inferior vena cava (IVC) is essential in this population. Yet it is not always possible to evaluate using the traditional subcostal view. METHODS: This cross-sectional study of 36 consecutive adult patients who underwent cardiac surgery included those in whom it was possible to adequately visualize the IVC in both the subcostal and transhepatic views. The maximum and minimum diameters and respirophasic variation were measured in each view. These views were then correlated and the capacity of the transhepatic view to predict fluid responsiveness was evaluated. RESULTS: There was a strong positive correlation between IVC maximum and minimum diameters and respirophasic variation according to subcostal and transhepatic views. Evaluation of IVC respirophasic variation indices using the transhepatic view also showed high sensitivity for predicting fluid responsiveness. CONCLUSION: There is a correlation between the transhepatic and subcostal views for determining maximum and minimum IVC diameters, and distensibility and variability indices for predicting fluid responsiveness in postoperative cardiac surgery patients.

Loxin Reduced the Inflammatory Response in the Liver and the Aortic Fatty Streak Formation in Mice Fed with a High-Fat Diet.

Oxidized low-density lipoprotein (ox-LDL) is the most harmful form of cholesterol associated with vascular atherosclerosis and hepatic injury, mainly due to inflammatory cell infiltration and subsequent severe tissue injury. Lox-1 is the central ox-LDL receptor expressed in endothelial and immune cells, its activation regulating inflammatory cytokines and chemotactic factor secretion. Recently, a Lox-1 truncated protein isoform lacking the ox-LDL binding domain named LOXIN has been described. We have previously shown that LOXIN overexpression blocked Lox-1-mediated ox-LDL internalization in human endothelial progenitor cells in vitro. However, the functional role of LOXIN in targeting inflammation or tissue injury in vivo remains unknown. In this study, we investigate whether LOXIN modulated the expression of Lox-1 and reduced the inflammatory response in a high-fat-diet mice model. Results indicate that human LOXIN blocks Lox-1 mediated uptake of ox-LDL in H4-II-E-C3 cells. Furthermore, in vivo experiments showed that overexpression of LOXIN reduced both fatty streak lesions in the aorta and inflammation and fibrosis in the liver. These findings were associated with the down-regulation of Lox-1 in endothelial cells. Then, LOXIN prevents hepatic and aortic tissue damage in vivo associated with reduced Lox-1 expression in endothelial cells. We encourage future research to understand better the underlying molecular mechanisms and potential therapeutic use of LOXIN.

Approach to cardiology residents clinical aptitude evaluation. Multicenter design.

INTRODUCTION: To the best of our knowledge, the research herein presented is the first multicenter study in Mexico to analyze the development of clinical aptitude in medical units that train cardiologists. OBJECTIVE: To determine the degree of development of clinical aptitude in cardiology residents at three High Specialty Medical Units. METHODS: Multicenter, cross-sectional design. All students of the 2019-2020 academic year were included in the study. An instrument was constructed that evaluated clinical aptitude based on eight indicators and 170 items; conceptual/content validity and reliability were assessed by five cardiologists with teaching and educational research experience. RESULTS: By indicator and year of residence, significant statistical differences were observed in the CMN20Nov academic site. At HCSXXI and INCICh, statistically significant differences were observed in one of eight indicators. Differences between R1 residents (n = 41) of all three academic sites were estimated by indicator, with statistical significance being recorded in three of eight indicators. Between R2 (n = 35) and between R3 residents (n = 43), the result was similar. CONCLUSIONS: The degree of clinical aptitude development can be considered intermediate in all three academic sites, probably because the instrument explored problematized clinical situations that required for the residents to critically reflect on their clinical experience.

INTRODUCCIÓN: Hasta donde se tiene conocimiento, la investigación que se presenta constituye el primer trabajo multicéntrico en México que estudia el desarrollo de la aptitud clínica en unidades formadoras de cardiólogos. OBJETIVO: Determinar el grado de desarrollo de la aptitud clínica en residentes de cardiología en tres unidades médicas de alta especialidad. MÉTODOS: Diseño transversal multicéntrico. Se analizaron todos los estudiantes del ciclo académico 2019-2020. Se construyó un instrumento que evaluó la aptitud clínica a partir de ocho indicadores y 170 ítems; la validez conceptual/de contenido y la confiabilidad fueron valoradas por cinco cardiólogos con experiencia docente y en investigación educativa. RESULTADOS: Por indicador y año de residencia se observaron diferencias estadísticas significativas en la sede CMN20Nov; en HCSXXI e INCICh se observaron diferencias estadísticamente significativas en uno de ocho indicadores. Se estimaron diferencias entre residentes R1 (n = 41) de las tres sedes por indicador, con significación estadística en tres de ocho indicadores. El resultado fue semejante al comparar R2 (n = 35) y R3 (n = 43). CONCLUSIONES: El grado de desarrollo de la aptitud clínica se puede considerar medio en las tres sedes académicas, probablemente debido a que el instrumento exploró situaciones clínicas problematizadas que exigieron del residente la reflexión crítica de su experiencia clínica.

Proteomics-based screening of the endothelial heparan sulfate interactome reveals that C-type lectin 14a (CLEC14A) is a heparin-binding protein.

Animal cells express heparan sulfate proteoglycans that perform many important cellular functions by way of heparan sulfate-protein interactions. The identification of membrane heparan sulfate-binding proteins is challenging because of their low abundance and the need for extensive enrichment. Here, we report a proteomics workflow for the identification and characterization of membrane-anchored and extracellular proteins that bind heparan sulfate. The technique is based on limited proteolysis of live cells in the absence of denaturation and fixation, heparin-affinity chromatography, and high-resolution LC-MS/MS, and we designate it LPHAMS. Application of LPHAMS to U937 monocytic and primary murine and human endothelial cells identified 55 plasma membrane, extracellular matrix, and soluble secreted proteins, including many previously unidentified heparin-binding proteins. The method also facilitated the mapping of the heparin-binding domains, making it possible to predict the location of the heparin-binding site. To validate the discovery feature of LPHAMS, we characterized one of the newly-discovered heparin-binding proteins, C-type lectin 14a (CLEC14A), a member of the C-type lectin family that modulates angiogenesis. We found that the C-type lectin domain of CLEC14A binds one-to-one to heparin with nanomolar affinity, and using molecular modeling and mutagenesis, we mapped its heparin-binding site. CLEC14A physically interacted with other glycosaminoglycans, including endothelial heparan sulfate and chondroitin sulfate E, but not with neutral or sialylated oligosaccharides. The LPHAMS technique should be applicable to other cells and glycans and provides a way to expand the repertoire of glycan-binding proteins for further study.

Bilateral spontaneous pneumothorax in SARS-CoV-2 infection: A very rare, life-threatening complication.

In the coronavirus disease 2019 (COVID-19) era, the presence of acute respiratory failure is generally associated with acute respiratory distress syndrome; however, it is essential to consider other differential diagnoses that require different, and urgent, therapeutic approaches. Herein we describe a COVID-19 case complicated with bilateral spontaneous pneumothorax. A previously healthy 45-year-old man was admitted to our emergency department with sudden-onset chest pain and progressive shortness of breath 17 days after diagnosis with uncomplicated COVID-19 infection. He was tachypneic and presented severe hypoxemia (75% percutaneous oxygen saturation). Breath sounds were diminished bilaterally on auscultation. A chest X-ray revealed the presence of a large bilateral pneumothorax. A thoracic computed tomography (CT) scan confirmed the large bilateral pneumothorax, with findings consistent with severe COVID-19 infection. Chest tubes were inserted, with immediate clinical improvement. Follow-up chest CT scan revealed resolution of bilateral pneumothorax, reduction of parenchymal consolidation, and formation of large bilateral pneumatoceles. The patient remained under observation and was then discharged home. Bilateral spontaneous pneumothorax is a very rare, potentially life-threatening complication in patients with COVID-19. This case highlights the importance of recognizing this complication early to prevent potentially fatal consequences.

Right ventricular dysfunction and right ventricular-arterial uncoupling at admission increase the in-hospital mortality in patients with COVID-19 disease.

BACKGROUND: Coronavirus disease 2019 (COVID-19) frequently involves cardiovascular manifestations such as right ventricular (RV) dysfunction and alterations in pulmonary hemodynamics. We evaluated the application of the critical care ultrasonography ORACLE protocol to identify the most frequent alterations and their influence on adverse outcomes, especially those involving the RV (dilatation and dysfunction). METHODS: This cross-sectional study included 204 adult patients with confirmed COVID-19 admitted at three centers. Echocardiography and lung ultrasound images were acquired on admission using the ORACLE ultrasonography algorithm. RESULTS: Two-hundred and four consecutive patients were evaluated: 22 (11.9%) demonstrated a fractional shortening of < 35%; 33 (17.1%) a tricuspid annular plane systolic excursion (TAPSE) of < 17 mm; 26 (13.5%) a tricuspid peak systolic S wave tissue Doppler velocity of < 9.5 cm/sec; 69 (37.5%) a RV basal diameter of > 41 mm; 119 (58.3%) a pulmonary artery systolic pressure (PASP) of > 35 mm Hg; and 14 (11%) a TAPSE/PASP ratio of < .31. The in-hospital mortality rate was 37.6% (n = 71). Multiple logistic regression modeling showed that PASP > 35 mm Hg, RV FS of < 35%, TAPSE < 17 mm, RV S wave < 9.5, and TAPSE/PASP ratio < .31 mm/mm Hg were associated with this outcome. PASP and the TAPSE/PASP ratio had the lowest feasibility of being obtained among the investigators (62.2%). CONCLUSION: The presence of RV dysfunction, pulmonary hypertension, and alteration of the RV-arterial coupling conveys an increased risk of in-hospital mortality in patients presenting with COVID-19 upon admission; therefore, searching for these alterations should be routine. These parameters can be obtained quickly and safely with the ORACLE protocol.

Niveles de procalcitonina y ferritina predicen la gravedad de Covid-19 en pacientes ingresados a la unidad de cuidados intensivos.

No disponible.

Use of pulmonary ultrasound to predict in-hospital mortality in patients with COVID-19 infection.

INTRODUCTION: Lung ultrasound (LUS) implementation in patients with COVID-19 can help to establish the degree of pulmonary involvement, evaluate treatment response and estimate in-hospital outcome. OBJECTIVE: To evaluate the application of a LUS protocol in patients with COVID-19 infection to predict in-hospital mortality. METHODS: The study was carried out from April 1 to August 1, 2020 in patients with COVID-19 infection admitted to the Intensive Care Unit. Lung evaluation was carried out by physicians trained in critical care ultrasonography. RESULTS: Most patients were males, median age was 56 years, and 59 % required mechanical ventilation. In-hospital mortality was 39.4 %, and in those with a LUS score ≥ 19, mortality was higher (50 %). The multiple logistic regression model showed that a LUS score ≥ 19 was significantly associated with mortality (hazard ratio = 2.55, p = 0.01). CONCLUSIONS: LUS is a safe and fast clinical tool that can be applied at bedside in patients with COVID-19 infection to establish the degree of parenchymal involvement and predict mortality.

INTRODUCCIÓN: La implementación del ultrasonido pulmonar (LUS) en los pacientes con COVID-19 puede ayudar a establecer el grado de afectación pulmonar, evaluar la respuesta al tratamiento y estimar el desenlace intrahospitalario. OBJETIVO: Evaluar la aplicación de un protocolo LUS en pacientes con infección por COVID-19 para predecir mortalidad intrahospitalaria. MÉTODOS: El estudio se realizó del 1 de abril al 1 de agosto de 2020 en pacientes con infección por COVID-19, ingresados en la Unidad de Terapia Intensiva. Se realizó evaluación pulmonar por médicos entrenados en ultrasonografía crítica. RESULTADOS: La mayoría de los pacientes fue del sexo masculino, la edad mediana fue de 56 años y 59 % requirió ventilación mecánica. La mortalidad intrahospitalaria fue de 39.4 % y en aquellos con puntuación de LUS ≥ 19, de 50 %. El modelo de regresión logística múltiple mostró que la puntuación de LUS ≥ 19 se asoció significativamente a mortalidad (cociente de riesgo = 2.55, p = 0.01). CONCLUSIONES: El LUS es una herramienta clínica segura y rápida que puede realizarse al lado de la cama de los pacientes con infección por COVID-19, para establecer el grado de afectación parenquimatosa y predecir la mortalidad.

Shortening heparan sulfate chains prolongs survival and reduces parenchymal plaques in prion disease caused by mobile, ADAM10-cleaved prions.

Cofactors are essential for driving recombinant prion protein into pathogenic conformers. Polyanions promote prion aggregation in vitro, yet the cofactors that modulate prion assembly in vivo remain largely unknown. Here we report that the endogenous glycosaminoglycan, heparan sulfate (HS), impacts prion propagation kinetics and deposition sites in the brain. Exostosin-1 haploinsufficient (Ext1+/-) mice, which produce short HS chains, show a prolonged survival and a redistribution of plaques from the parenchyma to vessels when infected with fibrillar prions, and a modest delay when infected with subfibrillar prions. Notably, the fibrillar, plaque-forming prions are composed of ADAM10-cleaved prion protein lacking a glycosylphosphatidylinositol anchor, indicating that these prions are mobile and assemble extracellularly. By analyzing the prion-bound HS using liquid chromatography-mass spectrometry (LC-MS), we identified the disaccharide signature of HS differentially bound to fibrillar compared to subfibrillar prions, and found approximately 20-fold more HS bound to the fibrils. Finally, LC-MS of prion-bound HS from human patients with familial and sporadic prion disease also showed distinct HS signatures and higher HS levels associated with fibrillar prions. This study provides the first in vivo evidence of an endogenous cofactor that accelerates prion disease progression and enhances parenchymal deposition of ADAM10-cleaved, mobile prions.