Mechanical dispersion is a superior echocardiographic feature to predict exercise capacity in preclinical and overt heart failure with preserved ejection fraction.

Background: Heart Failure with Preserved Ejection Fraction (HFpEF) is a syndrome characterized by different degrees of exercise intolerance, which leads to poor quality of life and prognosis. Recently, the European score (HFA-PEFF) was proposed to standardize the diagnosis of HFpEF. Even though Global Longitudinal Strain (GLS) is a component of HFA-PEFF, the role of other strain parameters, such as Mechanical Dispersion (MD), has yet to be studied.

Afterload increase challenge unmasks systolic abnormalities in heart failure with preserved ejection fraction.

Background: Provocative maneuvers have the potential to overcome the low sensitivity of resting echocardiography and biomarkers in the detection of heart failure with preserved ejection fraction (HFpEF). We investigate the mechanical response of the left ventricle to an afterload challenge in patients with preclinical and early-stage HFpEF (es-HFpEF).

Methods: Three groups of patients (non-HFpEF - n = 42, pre-HFpEF - n = 43, and es-HFpEF - n = 39) underwent echocardiography at rest and during an afterload challenge induced by handgrip maneuver combined with pneumatic constriction of limbs.

Metformin acts in the gut and induces gut-liver crosstalk.

Metformin is the most prescribed drug for DM2, but its site and mechanism of action are still not well established. Here, we investigated the effects of metformin on basolateral intestinal glucose uptake (BIGU), and its consequences on hepatic glucose production (HGP). In diabetic patients and mice, the primary site of metformin action was the gut, increasing BIGU, evaluated through PET-CT.

Personalized medicine using omics approaches in acute respiratory distress syndrome to identify biological phenotypes.

In the last decade, research on acute respiratory distress syndrome (ARDS) has made considerable progress. However, ARDS remains a leading cause of mortality in the intensive care unit. ARDS presents distinct subphenotypes with different clinical and biological features.

Discovery and structural characterization of chicoric acid as a SARS-CoV-2 nucleocapsid protein ligand and RNA binding disruptor.

The nucleocapsid (N) protein plays critical roles in coronavirus genome transcription and packaging, representing a key target for the development of novel antivirals, and for which structural information on ligand binding is scarce. We used a novel fluorescence polarization assay to identify small molecules that disrupt the binding of the N protein to a target RNA derived from the SARS-CoV-2 genome packaging signal. Several phenolic compounds, including L-chicoric acid (CA), were identified as high-affinity N-protein ligands.

Identification and characterization of the anti-SARS-CoV-2 activity of cationic amphiphilic steroidal compounds.

The ongoing COVID-19 pandemic caused a significant loss of human lives and a worldwide decline in quality of life. Treatment of COVID-19 patients is challenging, and specific treatments to reduce COVID-19 aggravation and mortality are still necessary. Here, we describe the discovery of a novel class of epiandrosterone steroidal compounds with cationic amphiphilic properties that present antiviral activity against SARS-CoV-2 in the low micromolar range.

Randomized clinical trial of BCG vaccine in patients with convalescent COVID-19: Clinical evolution, adverse events, and humoral immune response.

Background: The Bacillus Calmette-Guérin (BCG) vaccine may confer cross-protection against viral diseases in adults. This study evaluated BCG vaccine cross-protection in adults with convalescent coronavirus disease 2019 (COVID-19).

Method: This was a multicenter, prospective, randomized, placebo-controlled, double-blind phase III study (ClinicalTrials.

Structural dynamics of SARS-CoV-2 nucleocapsid protein induced by RNA binding.

The nucleocapsid (N) protein of the SARS-CoV-2 virus, the causal agent of COVID-19, is a multifunction phosphoprotein that plays critical roles in the virus life cycle, including transcription and packaging of the viral RNA. To play such diverse roles, the N protein has two globular RNA-binding modules, the N- (NTD) and C-terminal (CTD) domains, which are connected by an intrinsically disordered region. Despite the wealth of structural data available for the isolated NTD and CTD, how these domains are arranged in the full-length protein and how the oligomerization of N influences its RNA-binding activity remains largely unclear.

Nitazoxanide in Patients Hospitalized With COVID-19 Pneumonia: A Multicentre, Randomized, Double-Blind, Placebo-Controlled Trial.

Background: Nitazoxanide exerts antiviral activity and and anti-inflammatory effects, but its impact on patients hospitalized with COVID-19 pneumonia is uncertain.

Methods: A multicentre, randomized, double-blind, placebo-controlled trial was conducted in 19 hospitals in Brazil. Hospitalized adult patients requiring supplemental oxygen, with COVID-19 symptoms and a chest computed tomography scan suggestive of viral pneumonia or positive RT-PCR test for COVID-19 were enrolled.

Developmental differences in myocardial transmembrane Na transport: implications for excitability and Na handling.

Little is currently known about possible developmental changes in myocardial Na handling, which may have impact on cell excitability and Ca content. Resting intracellular Na concentration ([Na ] ), measured in freshly isolated rat ventricular myocytes with CoroNa green, was not significantly different in neonates (3-5 days old) and adults, but electrical stimulation caused marked [Na ] rise only in neonates. Inhibition of L-type Ca current by CdCl abolished not only systolic Ca transients, but also activity-dependent intracellular Na accumulation in immature cells.

Sequential IgG antibody monitoring for virus-inactivated and adenovirus-vectored COVID-19 vaccine in Brazilian healthcare workers.

Vaccination certainly is the best way to fight against the COVID-19 pandemic. In this study, the seroconversion effectiveness of two vaccines against severe acute respiratory syndrome coronavirus 2 was assessed in healthcare workers: virus-inactivated CoronaVac (CV, n = 303), and adenovirus-vectored Oxford-AstraZeneca (AZ, n = 447). The immunoglobulin G (IgG) antibodies anti-spike glycoprotein and anti-nucleocapsid protein were assessed by enzyme-linked immunosorbent assay at the time before vaccination (T1), before the second dose (T2), and 30 days after the second dose (T3).

Isolation, culture, and immunostaining of neonatal rat ventricular myocytes.

Isolation and culture of ventricular cardiomyocytes from neonatal rats (NRVMs) is a powerful model to study neonatal cardiac development, cell cycle regulation, and cardiac physiology and pathology . Here, we present our modified enzymatic digestion protocol followed by two-step discontinuous Percoll gradient centrifugation to isolate a high yield of viable ventricular cardiomyocytes from neonatal rats. Finally, here we describe an immunostaining protocol for cytosolic and nuclear staining of NRVMs.

Serological Testing for COVID-19, Immunological Surveillance, and Exploration of Protective Antibodies.

Serological testing is a powerful tool in epidemiological studies for understanding viral circulation and assessing the effectiveness of virus control measures, as is the case of SARS-CoV-2, the pathogenic agent of COVID-19. Immunoassays can quantitatively reveal the concentration of antiviral antibodies. The assessment of antiviral antibody titers may provide information on virus exposure, and changes in IgG levels are also indicative of a reduction in viral circulation.

Molecular and cellular basis of hyperassembly and protein aggregation driven by a rare pathogenic mutation in DDX3X.

Current studies estimate that 1-3% of females with unexplained intellectual disability (ID) present splice site, nonsense, frameshift, or missense mutations in the DDX3X protein (DEAD-Box Helicase 3 X-Linked). However, the cellular and molecular mechanisms by which DDX3X mutations impair brain development are not fully comprehended. Here, we show that the ID-linked missense mutation L556S renders DDX3X prone to aggregation.

Lentiviral transduction of neonatal rat ventricular myocytes preserves ultrastructural features of genetically modified cells.

Preserving morphological features that are important for cell function and structure is a critical parameter for in vitro experiments with rat cardiomyocytes. Lentiviral vectors are commonly used as gene transfer tool because of its high flexibility, efficiency to deliver expression cassettes and versatility of transducing quiescent cells. The tropism of the recombinant viral particle can be determined depending on the virus envelope, which shows a specific binding to cell surface receptors on the target cell.

Early use of nitazoxanide in mild COVID-19 disease: randomised, placebo-controlled trial.

Background: Nitazoxanide is widely available and exerts broad-spectrum antiviral activity . However, there is no evidence of its impact on severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection.

Methods: In a multicentre, randomised, double-blind, placebo-controlled trial, adult patients presenting up to 3 days after onset of coronavirus disease 2019 (COVID-19) symptoms (dry cough, fever and/or fatigue) were enrolled.

MEF2C repressor variant deregulation leads to cell cycle re-entry and development of heart failure.

Background: A pathophysiological link exists between dysregulation of MEF2C transcription factors and heart failure (HF), but the underlying mechanisms remain elusive. Alternative splicing of MEF2C exons α, β and γ provides transcript diversity with gene activation or repression functionalities.

Methods: Neonatal and adult rat ventricular myocytes were used to overexpress MEF2C splicing variants γ+ (repressor) or γ-, or the inactive MEF2Cγ+23/24 (K23T/R24L).

Planning, Implementing, and Running a Multicentre Preterm Birth Study with Biobank Resources in Brazil: The Preterm SAMBA Study.

Background: Our aim was to describe the steps in planning, implementing, and running a multicentre cohort study of maternal and perinatal health using a high-quality biobank comprised of maternal serum, plasma, and hair samples collected from five sites in Brazil. The Preterm SAMBA study, conducted by the Brazilian Network for Studies on Reproductive and Perinatal Health, was an innovative approach used to identify women at higher risk for preterm birth. It is also of great importance in the study of other maternal and perinatal complications in the context of Brazil, which is a middle-income country.

Mechanistic insights revealed by a UBE2A mutation linked to intellectual disability.

Ubiquitin-conjugating enzymes (E2) enable protein ubiquitination by conjugating ubiquitin to their catalytic cysteine for subsequent transfer to a target lysine side chain. Deprotonation of the incoming lysine enables its nucleophilicity, but determinants of lysine activation remain poorly understood. We report a novel pathogenic mutation in the E2 UBE2A, identified in two brothers with mild intellectual disability.

High-resolution synchrotron-based X-ray microtomography as a tool to unveil the three-dimensional neuronal architecture of the brain.

The assessment of neuronal number, spatial organization and connectivity is fundamental for a complete understanding of brain function. However, the evaluation of the three-dimensional (3D) brain cytoarchitecture at cellular resolution persists as a great challenge in the field of neuroscience. In this context, X-ray microtomography has shown to be a valuable non-destructive tool for imaging a broad range of samples, from dense materials to soft biological specimens, arisen as a new method for deciphering the cytoarchitecture and connectivity of the brain.

Adenosine Kinase couples sensing of cellular potassium depletion to purine metabolism.

Adenosine Kinase (ADK) regulates the cellular levels of adenosine (ADO) by fine-tuning its metabolic clearance. The transfer of γ-phosphate from ATP to ADO by ADK involves regulation by the substrates and products, as well as by Mg and inorganic phosphate. Here we present new crystal structures of mouse ADK (mADK) binary (mADK:ADO; 1.

Development of a flow cytometry assay which allows to evaluate the efficiency of immunomodulatory vaccines to enhance T cell-mediated antitumor response.

Immunotherapy has revolutionized the treatment of cancer. Since tumor cells exhibit low immunogenicity and can induce several mechanisms of tolerance, the use of monoclonal antibodies or other immunomodulators, targeting costimulation of T cells may mediate the inhibition of immunosuppressive mechanisms, favouring immune surveillance and enhancing the detection and elimination of tumor cells. We developed a new in vitro assay, based on flow cytometry, which allows exploring the therapeutic potential of tumor-derived immunomodulatory lineages, enhancing anti-tumor response.