Mixed-Methods Study of Disability Self-Management in Mexican Americans With Osteoarthritis.

BACKGROUND: Health disparities in osteoarthritis (OA) outcomes exist both in the occurrence and treatment of functional limitation and disability for Mexican Americans. Although the effect of self-management of chronic illness is well established, studies demonstrate little attention to self-management of function or disability, despite the strong potential effect on both and, consequently, on patients' lives. OBJECTIVE: The purpose of this study pilot was to develop and test key variable relationships for a measure of disability self-management among Mexican Americans. METHODS: In this sequential, two-phased, mixed-methods, biobehavioral pilot study of Mexican American women and men with OA, a culturally tailored measure of disability self-management was created, and initial relationships among key variables were explored. RESULTS: First, a qualitative study of 19 adults of Mexican American descent born in Texas (United States) or Mexico was conducted. The Mexican American Disability Self-Management Scale was created using a descriptive content analysis of interview data. The scale was tested and refined, resulting in 18 items and a descriptive frequency of therapeutic management efforts. Second, correlations between study variables were estimated: Disability and function were negatively correlated. Disability correlated positively with social support and activity effort. Disability correlated negatively with disability self-management, pain, and C-reactive protein. Function was positively correlated with age, pain, and depression. Liver enzymes (alanine transaminase) correlated positively with pain and anxiety. DISCUSSION: This mixed-methods study indicates directions for further testing and interventions for disability outcomes among Mexican Americans.

Multivalent, calcium-independent binding of surfactant protein A and D to sulfated glycosaminoglycans of the alveolar epithelial glycocalyx.

Lung surfactant collectins, surfactant protein A (SP-A) and D (SP-D), are oligomeric C-type lectins involved in lung immunity. Through their carbohydrate recognition domain, they recognize carbohydrates at pathogen surfaces and initiate lung innate immune response. Here, we propose that they may also be able to bind to other carbohydrates present in typical cell surfaces, such as the alveolar epithelial glycocalyx. To test this hypothesis, we analyzed and quantified the binding affinity of SP-A and SP-D to different sugars and glycosaminoglycans (GAGs) by microscale thermophoresis (MST). In addition, by changing the calcium concentration, we aimed to characterize any consequences on the binding behavior. Our results show that both oligomeric proteins bind with high affinity (in nanomolar range) to GAGs, such as hyaluronan (HA), heparan sulfate (HS) and chondroitin sulfate (CS). Binding to HS and CS was calcium-independent, as it was not affected by changing calcium concentration in the buffer. Quantification of GAGs in bronchoalveolar lavage (BAL) fluid from animals deficient in either SP-A or SP-D showed changes in GAG composition, and electron micrographs showed differences in alveolar glycocalyx ultrastructure in vivo. Taken together, SP-A and SP-D bind to model sulfated glycosaminoglycans of the alveolar epithelial glycocalyx in a multivalent and calcium-independent way. These findings provide a potential mechanism for SP-A and SP-D as an integral part of the alveolar epithelial glycocalyx binding and interconnecting free GAGs, proteoglycans, and other glycans in glycoproteins, which may influence glycocalyx composition and structure.NEW & NOTEWORTHY SP-A and SP-D function has been related to innate immunity of the lung based on their binding to sugar residues at pathogen surfaces. However, their function in the healthy alveolus was considered as limited to interaction with surfactant lipids. Here, we demonstrated that these proteins bind to glycosaminoglycans present at typical cell surfaces like the alveolar epithelial glycocalyx. We propose a model where these proteins play an important role in interconnecting alveolar epithelial glycocalyx components.

Quantitative sensory testing defines the trajectory of sensory neuropathy after severe COVID-19.

AIMS: To assess sensory neuropathy development after severe COVID-19. METHODS: Patients with severe COVID-19 underwent assessment of neuropathic symptoms, tendon reflexes, and quantitative sensory testing to evaluate vibration (VPT), cold (CPT), warm (WPT) and heat perception thresholds (HPT) within 1-3 weeks of admission and after 1-year. RESULTS: 32 participants with severe COVID-19 aged 68.6 ± 12.4 (18.8 % diabetes) were assessed. At baseline, numbness and neuropathic pain were present in 56.3 % and 43.8 % of participants, respectively. On the feet, VPT, WPT, and HPT were abnormal in 81.3 %, CPT was abnormal in 50.0 % and HPT on the face was abnormal in 12.5 % of patients. At 1-year follow-up, the prevalence of abnormal VPT (81.3 % vs 50.0 %, P < 0.01), WPT (81.3 % vs 43.8 %, P < 0.01), and HPT (81.3 % vs 50.0 %, P < 0.01) decreased, with no change in CPT (P = 0.21) on the feet or HPT on the face (P = 1.0). Only participants without diabetes recovered from an abnormal VPT, CPT, and WPT. Patients with long-COVID (37.5 %) had comparable baseline VPT, WPT and CPT with those without long-COVID (P = 0.07-0.69). CONCLUSIONS: Severe COVID-19 is associated with abnormal vibration and thermal thresholds which are sustained for up to 1 year in patients with diabetes. Abnormal sensory thresholds have no association with long-COVID development.

Grey Matter Reshaping of Language-Related Regions Depends on Tumor Lateralization.

A brain tumor in the left hemisphere can decrease language laterality as assessed through fMRI. However, it remains unclear whether or not this decreased language laterality is associated with a structural reshaping of the grey matter, particularly within the language network. Here, we examine if the disruption of the language hubs exclusively affects the macrostructural properties of the contralateral homologues or whether it affects both hemispheres. This study uses voxel-based morphometry applied to high-resolution MR T1-weighted MPRAGE images from 31 adult patients' left hemisphere, which is dominant for language. Eighteen patients had brain tumors in the left hemisphere, and thirteen had tumors in the right hemisphere. A cohort of 71 healthy individuals matched with respect to age and sex was used as a baseline. We defined 10 ROIs per hemisphere involved in language function. Two separate repeated-measure ANOVAs were conducted with the volume per region as the dependent variable. For the patients, tumor lateralization (right versus left) served as a between-subject factor. The current study demonstrated that the presence of a brain tumor generates global volumetric changes affecting the left language regions and their contralateral homologues. These changes are mediated by the lateralization of the lesion. Our findings suggest that functional mechanisms are supported by the rearrangement of the grey matter.

The Life-Course Perspectives of Mexican American Men With Mobility Limitation.

The life-history narratives of 10 Mexican American men with mobility limitations, age 55-77 years (mean = 63.8, SD = 5.8), were explored using a qualitatively driven, life-history mixed-methods study to understand perceptions of mobility limitations over the life course. Within that methodological and paradigmatic framework, conceptualizations of alterity and masculinity guided interpretation of data. Through an iterative, thematic analysis, we detail the way the men's lives were influenced by growing familial responsibility with age. Quantitative data were integrated into themes of narrative inheritance, family, and masculinity. It was posited that masculinity with mobility limitations shaped and was shaped by ethnic identity and responsibility. This has implications for understanding the experience of Mexican American men over the life course.

Cell consequences of loss of function of the epigenetic factor EHMT1.

EHMT1 is an epigenetic factor with histone methyltransferase activity that appears mutated in Kleefstra syndrome, a neurodevelopmental genetic disorder characterized by developmental delay, intellectual disability, and autistic-like features. Despite recent progress in the study of the function of this gene and the molecular etiology of the disease, our knowledge of how EHMT1 haploinsufficiency causes Kleefstra syndrome is still very limited. Here, we show that EHMT1 depletion in RPE1 cells leads to alterations in the morphology and distribution of different subcellular structures, such as the Golgi apparatus, the lysosomes and different cell adhesion components. EHMT1 downregulation also increases centriolar satellites detection, which may indicate a role for EHMT1 in centrosome functioning. Furthermore, the migration process is also altered in EHMT1 depleted cells, which show reduced migration capacity. We consider that the described phenotypes could open new possibilities for understanding the functional impact of EHMT1 haploinsufficiency in Kleefstra syndrome, helping to elucidate the link between epigenetic regulation and the underlying cellular mechanisms that result in this neurodevelopmental disorder. This knowledge could be relevant not only for the treatment of this syndrome, but also for other neurodevelopmental conditions that could share similar deregulated cellular pathways.

Whole-Blood Gene Expression Profiles Associated with Mortality in Community-Acquired Pneumonia.

(1) Background: Information regarding gene expression profiles and the prognosis of community-acquired pneumonia (CAP) is scarce. We aimed to examine the differences in the gene expression profiles in peripheral blood at hospital admission between patients with CAP who died during hospitalization and those who survived. (2) Methods: This is a multicenter study of nonimmunosuppressed adult patients who required hospitalization for CAP. Whole blood samples were obtained within 24 h of admission for genome-expression-profile analysis. Gene expression profiling identified both differentially expressed genes and enriched gene sets. (3) Results: A total of 198 samples from adult patients who required hospitalization for CAP were processed, of which 13 were from patients who died. Comparison of gene expression between patients who died and those who survived yielded 49 differentially expressed genes, 36 of which were upregulated and 13 downregulated. Gene set enrichment analysis (GSEA) identified four positively enriched gene sets in survivors, mainly associated with the interferon-alpha response, apoptosis, and sex hormone pathways. Similarly, GSEA identified seven positively enriched gene sets, associated with the oxidative stress, endoplasmic reticulum stress, oxidative phosphorylation, and angiogenesis pathways, in the patients who died. Protein-protein-interaction-network analysis identified FOS, CDC42, SLC26A10, EIF4G2, CCND3, ASXL1, UBE2S, and AURKA as the main gene hubs. (4) Conclusions: We found differences in gene expression profiles at hospital admission between CAP patients who died and those who survived. Our findings may help to identify novel candidate pathways and targets for potential intervention and biomarkers for risk stratification.

Grey matter reshaping of language-related regions depends on tumor lateralization.

A brain tumor in the left hemisphere can decrease language laterality as assessed with fMRI. However, it remains unclear whether or not this decreased language laterality is associated with a structural reshaping of the grey matter, particularly within the language network. Here, we examine if the disruption of language hubs exclusively affects macrostructural properties of contralateral homologues (as suggested by previous research), or whether it affects both hemispheres. This study uses voxel-based morphometry applied to high-resolution MR T1-weighted MPRAGE images from 31 adult patients left-dominant for language. Eighteen patients had brain tumors in the left hemisphere, and 13 had tumors in the right hemisphere. A cohort of 71 healthy individuals matched on age and sex was used as a baseline. We defined 10 ROIs per hemisphere known to subserve language function. Two separate repeated-measures ANOVAs were conducted with the volume per region as the dependent variables. For the patients, tumor lateralization (right versus left) served as a between-subject factor. The current study demonstrated that the presence of a brain tumor generates a global volumetric change affecting left language regions and their contralateral homologues. These changes are mediated by the lateralization of the lesion. Our findings suggest that compensatory functional mechanisms are supported by the rearrangement of the grey matter, although future longitudinal research should determine the temporal course of such changes.

[Mesenteric venous thrombosis]. / Trombosis venosa mesentérica.

Mesenteric vein thrombosis (MVT) is a rare condition that can present acutely, subacutely, or chronically. MVT can be isolated or within a splanchnic thrombosis (spleno-porto-mesenteric). Symptomatic cases usually present as nonspecific abdominal pain, with or without signs of intestinal ischemia, and the diagnosis is usually made by imaging test (abdominal CT or MRI) in patients with high clinical suspicion. An early clinical-surgical approach is recommended to screen those patients with warning signs and who benefit from an exploratory laparotomy in addition to anticoagulant treatment, which is the cornerstone of medical treatment. MVT is usually associated with prothrombotic states, with hematological disorders (myeloproliferative syndromes and/or JAK2 gene mutations) being of special clinical relevance. On the other hand, the 5-year survival rate is 70-82% and early overall 30-day mortality from MVT can reach 20-32%.

The RNA-binding protein QKI governs a muscle-specific alternative splicing program that shapes the contractile function of cardiomyocytes.

AIMS: In the heart, splicing factors orchestrate the functional properties of cardiomyocytes by regulating the alternative splicing of multiple genes. Work in embryonic stem cells has shown that the splicing factor Quaking (QKI) regulates alternative splicing during cardiomyocyte differentiation. However, the relevance and function of QKI in adult cardiomyocytes remains unknown. In this study, we aim to identify the in vivo function of QKI in the adult mouse heart. METHODS AND RESULTS: We generated mice with conditional deletion of QKI in cardiomyocytes by the Cre-Lox system. Mice with cardiomyocyte-specific deletion of QKI died during the foetal period (E14.5), without obvious anatomical abnormalities of the heart. Adult mice with tamoxifen-inducible QKI deletion rapidly developed heart failure associated with severe disruption of sarcomeres, already 7 days after knocking out QKI. RNA sequencing revealed that QKI regulates the alternative splicing of more than 1000 genes, including sarcomere and cytoskeletal components, calcium-handling genes, and (post-)transcriptional regulators. Many of these splicing changes corresponded to the loss of muscle-specific isoforms in the heart. Forced overexpression of QKI in cultured neonatal rat ventricular myocytes directed these splicing events in the opposite direction and enhanced contractility of cardiomyocytes. CONCLUSION: Altogether, our findings show that QKI is an important regulator of the muscle-specific alternative splicing program that builds the contractile apparatus of cardiomyocytes.

MicroRNAs in extracellular vesicles released from epicardial adipose tissue promote arrhythmogenic conduction slowing.

Background: Patients with excess epicardial adipose tissue (EAT) are at increased risk of developing cardiac arrhythmias. EAT promotes arrhythmias by depolarizing the resting membrane of cardiomyocytes, which slows down conduction and facilitates re-entrant arrhythmias. We hypothesized that EAT slows conduction by secreting extracellular vesicles (EVs) and their microRNA (miRNA) cargo. Objective: We aimed to determine the role of EAT-derived EVs and their miRNA cargo in conduction slowing. Methods: EAT and subcutaneous adipose tissue (SAT) were collected from patients with atrial fibrillation. Adipose tissue explants were incubated in culture medium and secretome was collected. The numbers of EVs in the EAT and SAT secretome were measured by calibrated flow cytometry. EVs in the EAT secretome were isolated by size exclusion chromatography and miRNAs were sequenced. Pathway analysis was performed to predict candidates involved in cardiac electrophysiology. The candidates were validated in the EAT and SAT by quantitative real-time polymerase chain reaction. Finally, miRNA candidates were overexpressed in neonatal rat ventricular myocytes. Results: The EV concentration was higher in the EAT secretome than in the SAT and control secretomes. miRNA sequencing of EAT-derived EVs detected a total of 824 miRNAs. Pathway analysis led to the identification of 7 miRNAs potentially involved in regulation of cardiac resting membrane potential. Validation of those miRNA candidates showed that they were all expressed in EAT, and that miR-1-3p and miR-133a-3p were upregulated in EAT in comparison with SAT. Overexpression of miR-1-3p and miR-133a-3p in neonatal rat ventricular myocytes led to conduction slowing and reduced Kcnj2 and Kcnj12 expression. Conclusion: miR-1-3p and miR-133a-3p are potential mediators of EAT arrhythmogenicity.

shRNAs Targeting a Common KCNQ1 Variant Could Alleviate Long-QT1 Disease Severity by Inhibiting a Mutant Allele.

Long-QT syndrome type 1 (LQT1) is caused by mutations in KCNQ1. Patients heterozygous for such a mutation co-assemble both mutant and wild-type KCNQ1-encoded subunits into tetrameric Kv7.1 potassium channels. Here, we investigated whether allele-specific inhibition of mutant KCNQ1 by targeting a common variant can shift the balance towards increased incorporation of the wild-type allele to alleviate the disease in human-induced pluripotent stem-cell-derived cardiomyocytes (hiPSC-CMs). We identified the single nucleotide polymorphisms (SNP) rs1057128 (G/A) in KCNQ1, with a heterozygosity of 27% in the European population. Next, we determined allele-specificity of short-hairpin RNAs (shRNAs) targeting either allele of this SNP in hiPSC-CMs that carry an LQT1 mutation. Our shRNAs downregulated 60% of the A allele and 40% of the G allele without affecting the non-targeted allele. Suppression of the mutant KCNQ1 allele by 60% decreased the occurrence of arrhythmic events in hiPSC-CMs measured by a voltage-sensitive reporter, while suppression of the wild-type allele increased the occurrence of arrhythmic events. Furthermore, computer simulations based on another LQT1 mutation revealed that 60% suppression of the mutant KCNQ1 allele shortens the prolonged action potential in an adult cardiomyocyte model. We conclude that allele-specific inhibition of a mutant KCNQ1 allele by targeting a common variant may alleviate the disease. This novel approach avoids the need to design shRNAs to target every single mutation and opens up the exciting possibility of treating multiple LQT1-causing mutations with only two shRNAs.

Understanding the processes in a historically relevant thermal and mineral spring water by using mixing and inverse geochemical models.

The thermal mineral water of Peñón de los Baños spa (Mexico City) has been used for over 500 years starting in pre-Hispanic times and is famous for the treatment of various pathologies. It has a temperature of 45 °C, which is rich in HCO3-, and its main trace elements are B, Li and Fe, which confers healing effects. Concerns about the sustainability of this important spa have motivated this study to understand the thermal system, possible hydraulic and hydrochemical changes over time and its implications. Stable water isotope data indicate that the thermal water sources originate from local precipitation at Sierra de las Cruces with a recharge elevation of approximately 2770 m above sea level. The recharged water percolates through volcanic and carbonate rock formations and ascends via fault structure conduits, where it eventually is extracted 25 km downstream in Peñon de los Baños. During the gravity-driven deep circulation of up to 4.9 km, the groundwater is heated up to 136-160 °C. A comparison of past and current water levels and water chemical analyses indicates a water table drop and few variations in the chemical composition, confirming the presence of anthropic impact on water quality. Due to the heavy groundwater extractions in Mexico City, the spring water flow has ceased, and water must be pumped now from a 203-m deep well. In addition, the concentration of bicarbonate, sodium and chloride has been reduced by half since the onset of groundwater development. The therapeutic effects of this thermal mineral water are at risk due to the alteration of the chemical signature. However, new and different therapeutical uses may prevent a future deterioration or closure of this historically important thermal spa. It is crucial to establish a monitoring program of the thermal mineral water and reducing or minimizing nearby urban extractions which tap the regional flow component to preserve the properties of the thermal water.

Validation of a Prognostic Score to Identify Hospitalized Patients with COVID-19 at Increased Risk for Bleeding.

INTRODUCTION: Hospitalized patients with COVID-19 are at increased risk for venous thromboembolism (VTE), but also for bleeding. We previously derived a prognostic score including four variables (elevated D-dimer, elevated ferritin, critical illness, and therapeutic-dose anticoagulation) that identified those at increased risk for major bleeding. METHODS: We aimed to validate the score in a subsequent cohort of hospitalized patients with COVID-19 receiving standard-, intermediate- or therapeutic doses of VTE prophylaxis. We evaluated its capacity to predict major bleeding, non-major bleeding, and bleeding-related death. RESULTS: The cohort included 972 patients from 29 hospitals, of whom 280 (29%) received standard-; 412 (42%) intermediate-, 157 (16%) therapeutic doses of VTE prophylaxis and 123 (13%) other drugs. Median duration of prophylaxis was 14.7 ± 10.3 days. Major bleeding occurred in 65 patients (6.7%) and non-major bleeding in 67 (6.9%). Thirty patients with major bleeding (46%) died within the first 30 days after bleeding. The prognostic score identified 203 patients (21%) at very low risk, 285 (29%) at low risk, 263 (27%) intermediate-risk and 221 (23%) at high risk for bleeding. Major bleeding occurred in 1.0%, 2.1%, 8.7% and 15.4% of the patients, respectively. Non-major bleeding occurred in 0.5%, 3.5%, 9.5% and 14.2%, respectively. The c-statistics was: 0.74 (95% confidence intervals [CI]: 0.68-0.79) for major bleeding, 0.73 (95% CI: 0.67-0.78) for non-major bleeding and 0.82 (95% CI: 0.76-0.87) for bleeding-related death. CONCLUSIONS: In hospitalized patients with COVID-19, we validated that a prognostic score including 4 easily available items may identify those at increased risk for bleeding.

Isotopic composition and major ion concentrations of national and international bottled waters in Costa Rica.

Global bottled water consumption has largely increased (14.35 billion gallons in 2020) [1], [2], [3], [4], [5] during the last decade since consumers are demanding healthier and safer forms of rehydration. Bottled water sources are normally labeled as mountainous and pristine mineral springs (fed by rainfall and snow/glacier melting processes), deep groundwater wells or industrial purified water. The advent of numerous international and national-based bottled water brands has simultaneously raised a worldwide awareness related to the water source and chemical content traceability [6]. Here, we present the first database of stable isotope compositions and reported chemical concentrations from imported and national-based bottled waters in Costa Rica. In total, 45 bottled waters produced in Costa Rica and 31 imported from USA, Europe, Oceania, and other countries of Central America were analyzed for δ18O, δ2H, and d-excess. Chemical compositions were obtained from available bottle labels. National-based bottle waters ranged from -2.47‰ to -10.65‰ in δ18O and from -10.4‰ to -78.0‰ in δ2H, while d-excess varied from +4.2‰ up to +17.0‰. International bottle waters ranged between -2.21‰ and -11.03‰ in δ18O and from -11.3‰ up to -76.0‰ in δ2H, while d-excess varied from +5.0‰ up to +19.1‰. In Costa Rica, only 19% of the brands reported chemical parameters such as Na+, K+, Ca+2, Mg+2, F-, Cl-, NO3 -, SO4 -2, CO3 -2, SiO2, dry residue, and pH; whereas 27% of the international products reported similar parameters. The absence of specific geographic coordinates or water source origin limited a spatial analysis to validate bottled water isotope compositions versus available isoscapes in Costa Rica [7]. This database highlights the potential and relevance of the use of water stable isotope compositions to improve the traceability of bottled water sources and the urgent need of more robust legislation in order to provide detailed information (i.e., water source, chemical composition, purification processes) to the final consumers.

Inflammatory Biomarkers in the Short-Term Prognosis of Venous Thromboembolism: A Narrative Review.

The relationship between inflammation and venous thrombosis is not well understood. An inflammatory response may be both the cause and consequence of venous thromboembolism (VTE). In fact, several risk factors of VTE modulate thrombosis through inflammatory markers. Acute pulmonary embolism (PE) is burdened by a remarkable mortality rate, up to 34% in severely ill patients presenting with hemodynamic instability. Initial mortality risk stratification is based on hemodynamic instability. Patients with a situation of hemodynamic stability require immediate further risk assessment based on clinical, imaging, and circulating biomarkers, as well as the presence of comorbidities. Some inflammatory biomarkers have shown potential usefulness in the risk stratification of patients with VTE, especially acute PE. C-reactive protein on admission is associated with 30-day mortality and bleeding in VTE patients. P-selectin is associated with right ventricle dysfunction in PE patients and might be associated with VTE recurrences and the extension of thrombosis. Tissue factor microparticles are associated with VTE recurrence in cancer-associated thrombosis. Other inflammatory biomarkers present scarce evidence (inflammatory cytokines, erythrocyte sedimentation rate, fibrinogen, leukocyte count). In this manuscript, we will review the prognostic role of different inflammatory biomarkers available both for clinical practice and research in VTE patients.

Long-term outcomes of patients following hospitalization for coronavirus disease 2019: a prospective observational study.

OBJECTIVES: Few data are available regarding follow up of patients with coronavirus disease 2019 (COVID-19) after their discharge. We aim to describe the long-term outcomes of survivors of hospitalization for COVID-19 followed up first at an outpatient facility and subsequently by telephone. METHODS: Observational prospective study conducted at a tertiary general hospital. Clinical and radiological progression was assessed and data were recorded on a standardized reporting form. Patients were divided into three groups according to Pao2/Fio2 at hospitalization: Pao2/Fio2 >300, Pao2/Fio2 300-200 and Pao2/Fio2 <200. A logistic multivariate regression model was performed to identify factors associated with persistence of symptoms. RESULTS: For facility follow up, 302 individuals were enrolled. Median follow up was 45 days after discharge; 78% (228/294) of patients had COVID-19-related symptoms (53% asthenia, 56% respiratory symptoms) and 40% (122/302) had residual pulmonary radiographic lesions. Pao2/Fio2 <200 was an independent predictor of persistent dyspnoea (OR 1.87, 95% CI 1.38-2.52, p < 0.0001). Pao2/Fio2 >300 was associated with resolution of chest radiographic lesions (OR 0.56, 95% CI 0.42-0.74, p < 0.0001). Fifty per cent of patients required specific medical follow up after the first consultation and were transferred to another physician. A total of 294 patients were contacted for telephone follow up after a median follow-up time of 7 months. Fifty per cent of patients (147/294) still presented symptoms and 49% (145/294) had psychological disorders. Asthenia was identified in 27% (78/294) and dyspnoea in 10% (28/294) of patients independently of Pao2/Fio2. CONCLUSIONS: Patients with COVID-19 require long-term follow up because of the persistence of symptoms; patients with low Pao2/Fio2 during the acute illness require special attention.

Titin Circular RNAs Create a Back-Splice Motif Essential for SRSF10 Splicing.

BACKGROUND: TTN (Titin), the largest protein in humans, forms the molecular spring that spans half of the sarcomere to provide passive elasticity to the cardiomyocyte. Mutations that disrupt the TTN transcript are the most frequent cause of hereditary heart failure. We showed before that TTN produces a class of circular RNAs (circRNAs) that depend on RBM20 to be formed. In this study, we show that the back-splice junction formed by this class of circRNAs creates a unique motif that binds SRSF10 to enable it to regulate splicing. Furthermore, we show that one of these circRNAs (cTTN1) distorts both localization of and splicing by RBM20. METHODS: We calculated genetic constraint of the identified motif in 125 748 exomes collected from the gnomAD database. Furthermore, we focused on the highest expressed RBM20-dependent circRNA in the human heart, which we named cTTN1. We used shRNAs directed to the back-splice junction to induce selective loss of cTTN1 in human induced pluripotent stem cell-derived cardiomyocytes. RESULTS: Human genetics suggests reduced genetic tolerance of the generated motif, indicating that mutations in this motif might lead to disease. RNA immunoprecipitation confirmed binding of circRNAs with this motif to SRSF10. Selective loss of cTTN1 in human induced pluripotent stem cell-derived cardiomyocytes induced structural abnormalities, apoptosis, and reduced contractile force in engineered heart tissue. In line with its SRSF10 binding, loss of cTTN1 caused abnormal splicing of important cardiomyocyte SRSF10 targets such as MEF2A and CASQ2. Strikingly, loss of cTTN1 also caused abnormal splicing of TTN itself. Mechanistically, we show that loss of cTTN1 distorts both localization of and splicing by RBM20. CONCLUSIONS: We demonstrate that circRNAs formed from the TTN transcript are essential for normal splicing of key muscle genes by enabling splice regulators RBM20 and SRSF10. This shows that the TTN transcript also has regulatory roles, besides its well-known signaling and structural function. In addition, we demonstrate that the specific sequence created by the back-splice junction of these circRNAs has important functions. This highlights the existence of functionally important sequences that cannot be recognized as such in the human genome but provides an as-yet unrecognized source for functional sequence variation.

Long-term follow-up of patients with venous thromboembolism and COVID-19: Analysis of risk factors for death and major bleeding.

INTRODUCTION: COVID-19 predisposes patients to a higher risk of venous thromboembolism (VTE), although the extent of these implications is unclear and the risk of bleeding has been poorly evaluated. To date, no studies have reported long-term outcomes of patients with COVID-19 and VTE. METHOD: Prospective observational study to evaluate long-term (90 days or more) outcomes of patients diagnosed with VTE (PE, DVT of the extremities, or both) in the setting of COVID-19. The main outcome of the study was a compound of major bleeding and death. RESULTS: The study comprised 100 patients (mean age 65 ± 13.9 years). At the time of VTE diagnosis, 66% patients were hospitalized, 34.8% of them in the ICU. Mean follow-up was 97.9 ± 23.3 days. During the study period, 24% patients died and median time to death was 12 (IQR: 2.25-20.75) days, 11% patients had major bleeding and median time to event was 12 (IQR: 5-16) days. The cause of death was PE in 5% and bleeding in 2% of patients. There were no VTE recurrences. The main study outcome occurred in 29% patients. Risk of death or major bleeding was independently associated with ICU admission (HR 12.2; 95% CI 3.0-48.3), thrombocytopenia (HR 4.5; 95% CI 1.2-16.5), and cancer (HR 21.6; 95% CI 1.8-259). CONCLUSION: In patients with COVID-19 and VTE, mortality and major bleeding were high and almost a third of deaths were VTE-related. The majority of complications occurred in the first 30 days. ICU admission, thrombocytopenia, and cancer are risk factors for poor prognosis.