Follow-up study of COVID-19 sequelae (FOSCO study).

INTRODUCTION: We undertook the first study from India to evaluate the long-term health effects of coronavirus disease 2019 (COVID-19). METHODS: The patients enrolled in our post-COVID-19 clinic were followed up for assessment at 1, 3, 6 and 12 months after recovery from acute disease prospectively. RESULTS: 200 patients with mean age of 50.72 years and 57.5% males were analysed. 42.5% had severe and 17% had moderate disease at the time of diagnosis. The persistence of symptoms beyond 1 month of diagnosis was seen in 72.5% (145/200) patients. 8% (16/200) of the patients had post-COVID-19 complications that required rehospitalisation after discharge or recovery from acute COVID-19. The complications included respiratory failure (2%), lung cavities (3.5%), fungal infection, pericardial effusion, pneumothorax and death. The symptoms were persistent beyond 3 months in 51% (102/200) and beyond 6 months in 17.5% (35/200) of cases. The patients with persistent symptoms beyond 3 months and 6 months had significantly higher intensive care unit (ICU) admission during acute COVID-19, severe disease during acute COVID-19, and higher prevalence of comorbidities compared to the recovered patients. The clinical recovery was attained in 95.5% (91/200) patients, and the radiological recovery was attained in 97.92% patients at 1 year. The mean duration to clinical recovery was 174.2 days. CONCLUSIONS: COVID-19 recovery takes longer time. However, clinico-radiological recovery is attained in >95% cases by one year.

Diagnostic accuracy of daytime polysomnography: a reappraisal during the COVID-19 era.

Level I conventional polysomnography (PSG), the gold standard for diagnosing obstructive sleep apnea (OSA), requires an overnight stay. This study evaluated the role of daytime PSG as an alternative diagnostic tool. A prospective cohort study was undertaken with consecutive patients with suspected OSA at a tertiary care sleep center. The primary objective was to evaluate the sensitivity and diagnostic accuracy of daytime PSG for diagnosing OSA. The secondary objective was to find out the factors associated with a falsely negative daytime PSG result. All individuals were subjected to level I daytime PSG, done in the sleep lab in the presence of an experienced sleep technician during the daytime from 12 PM to 4 PM. Out of 162 patients, 105 underwent daytime PSG. OSA was diagnosed on daytime PSG in 86.7 out of the 19 remaining patients refused a repeat PSG study. Out of the 12 individuals who underwent the nighttime PSG for confirmatory diagnosis, 10 were diagnosed as OSA (false negatives), and 2 were confirmed as not-OSA (true negatives). The sensitivity, diagnostic accuracy, and negative predictive value of daytime PSG were 89.58%, 89.80%, and 16.67%, respectively. The false negatives had a higher prevalence of mild OSA. Daytime PSG is sensitive in diagnosing OSA and can be considered in individuals with severe symptoms at centers with a high patient load or when the individual wishes to avoid a nighttime study. A negative result in daytime PSG must be followed by conventional overnight PSG for confirmatory diagnosis.

Determining the defining lengths between mature microRNAs/small interfering RNAs and tinyRNAs.

MicroRNAs (miRNAs) and small interfering RNAs (siRNAs) are loaded into Argonaute (AGO) proteins, forming RNA-induced silencing complexes (RISCs). The assembly process establishes the seed, central, 3' supplementary, and tail regions across the loaded guide, enabling the RISC to recognize target RNAs for silencing. This guide segmentation is caused by anchoring the 3' end at the AGO PAZ domain, but the minimum guide length required for the conformation remains to be studied because the current miRNA size defined by Dicer processing is ambiguous. Using a 3' → 5' exonuclease ISG20, we determined the lengths of AGO-associated miR-20a and let-7a with 3' ends that no longer reach the PAZ domain. Unexpectedly, miR-20a and let-7a needed different lengths, 19 and 20 nt, respectively, to maintain their RISC conformation. This difference can be explained by the low affinity of the PAZ domain for the adenosine at g19 of let-7a, suggesting that the tail-region sequence slightly alters the minimum guide length. We also present that 17-nt guides are sufficiently short enough to function as tinyRNAs (tyRNAs) whose 3' ends are not anchored at the PAZ domain. Since tyRNAs do not have the prerequisite anchoring for the standardized guide segmentation, they would recognize targets differently from miRNAs and siRNAs.

Determining the defining lengths between mature microRNAs/small interfering RNAs and tinyRNAs.

MicroRNAs (miRNAs) and small interfering RNAs (siRNAs) are loaded into Argonaute (AGO) proteins, forming RNA-induced silencing complexes (RISCs). The assembly process establishes the seed, central, 3' supplementary, and tail regions across the loaded guide, enabling the RISC to recognize and cleave target RNAs. This guide segmentation is caused by anchoring the 3' end at the AGO PAZ domain, but the minimum guide length required for the conformation remains to be studied because there was no method by which to do so. Using a 3'→5' exonuclease ISG20, we determined the lengths of AGO-associated miR-20a and let-7a with 3' ends that no longer reach the PAZ domain. Unexpectedly, miR-20a and let-7a needed different lengths, 19 and 20 nt, respectively, to maintain their RISC conformation. This difference can be explained by the low affinity of the PAZ domain for the adenosine at g19 of let-7a, suggesting that the tail-region sequence slightly alters the minimum guide length. We also present that 17-nt guides are sufficiently short enough to function as tinyRNAs (tyRNAs) whose 3' ends are not anchored at the PAZ domain. Since tyRNAs do not have the prerequisite anchoring for the standardized guide segmentation, they would recognize targets differently from miRNAs and siRNAs.

Relevance of KCNJ5 in Pathologies of Heart Disease.

Abnormalities in G-protein-gated inwardly rectifying potassium (GIRK) channels have been implicated in diseased states of the cardiovascular system; however, the role of GIRK4 (Kir3.4) in cardiac physiology and pathophysiology has yet to be completely understood. Within the heart, the KACh channel, consisting of two GIRK1 and two GIRK4 subunits, plays a major role in modulating the parasympathetic nervous system's influence on cardiac physiology. Being that GIRK4 is necessary for the functional KACh channel, KCNJ5, which encodes GIRK4, it presents as a therapeutic target for cardiovascular pathology. Human variants in KCNJ5 have been identified in familial hyperaldosteronism type III, long QT syndrome, atrial fibrillation, and sinus node dysfunction. Here, we explore the relevance of KCNJ5 in each of these diseases. Further, we address the limitations and complexities of discerning the role of KCNJ5 in cardiovascular pathophysiology, as identical human variants of KCNJ5 have been identified in several diseases with overlapping pathophysiology.

A study on the prevalence of RLS in OSA and the consequences of co-occurrence.

Background: Restless leg syndrome (RLS) is common among patients with obstructive sleep apnoea (OSA) but the prognostic importance of this is not studied. We have called OSA and RLS coexistence as ComOSAR. Materials and Methods: A prospective observational study was done on patients referred for polysomnography (PSG) with the aims to evaluate 1) the prevalence of RLS in OSA and comparing it with RLS in non-OSA, 2) the prevalence of insomnia, psychiatric, metabolic and cognitive disorders in ComOSAR versus OSA alone, 3) chronic obstructive airway disease (COAD) in ComOSAR versus OSA alone. OSA, RLS and insomnia were diagnosed as per respective guidelines. They were evaluated for psychiatric disorders, metabolic disorders, cognitive disorders and COAD. Results: Of 326 patients enrolled, 249 were OSA and 77 were non-OSA. 61/249 OSA patients, i.e. 24.4% had comorbid RLS, i.e. ComOSAR. RLS in non-OSA patients was similar (22/77, i.e. 28.5%); P = 0.41. ComOSAR had a significantly higher prevalence of insomnia (26% versus 10.1%; P = 0.016), psychiatric disorders (73.7% versus 48.4%; P = 0.00026) and cognitive deficits (72.1% versus 54.7%, P = 0.016) compared to OSA alone. Metabolic disorders like metabolic syndrome, diabetes mellitus, hypertension and coronary artery disease were also observed in a significantly higher number of patients with ComOSAR versus OSA alone (57% versus 34%; P = 0.0015). COAD was also seen in a significantly higher number of patients with ComOSAR compared to OSA alone (49% versus 19% respectively; P = 0.00001). Conclusion: It is essential to look for RLS in patients with OSA as it leads to a significantly higher prevalence of insomnia, and cognitive, metabolic and psychiatric disorders. COAD is also more common in ComOSAR compared to OSA alone.

Impact of stress on cardiac phenotypes in mice harboring an ankyrin-B disease variant.

Encoded by ANK2, ankyrin-B (AnkB) is a multifunctional adapter protein critical for the expression and targeting of key cardiac ion channels, transporters, cytoskeletal-associated proteins, and signaling molecules. Mice deficient for AnkB expression are neonatal lethal, and mice heterozygous for AnkB expression display cardiac structural and electrical phenotypes. Human ANK2 loss-of-function variants are associated with diverse cardiac manifestations; however, human clinical 'AnkB syndrome' displays incomplete penetrance. To date, animal models for human arrhythmias have generally been knock-out or transgenic overexpression models and thus the direct impact of ANK2 variants on cardiac structure and function in vivo is not clearly defined. Here, we directly tested the relationship of a single human ANK2 disease-associated variant with cardiac phenotypes utilizing a novel in vivo animal model. At baseline, young AnkBp.E1458G+/+ mice lacked significant structural or electrical abnormalities. However, aged AnkBp.E1458G+/+ mice displayed both electrical and structural phenotypes at baseline including bradycardia and aberrant heart rate variability, structural remodeling, and fibrosis. Young and old AnkBp.E1458G+/+ mice displayed ventricular arrhythmias following acute (adrenergic) stress. In addition, young AnkBp.E1458G+/+ mice displayed structural remodeling following chronic (transverse aortic constriction) stress. Finally, AnkBp.E1458G+/+ myocytes harbored alterations in expression and/or localization of key AnkB-associated partners, consistent with the underlying disease mechanism. In summary, our findings illustrate the critical role of AnkB in in vivo cardiac function as well as the impact of single AnkB loss-of-function variants in vivo. However, our findings illustrate the contribution and in fact necessity of secondary factors (aging, adrenergic challenge, pressure-overload) to phenotype penetrance and severity.

Targeting prolyl-tRNA synthetase via a series of ATP-mimetics to accelerate drug discovery against toxoplasmosis.

The prolyl-tRNA synthetase (PRS) is a validated drug target for febrifugine and its synthetic analog halofuginone (HFG) against multiple apicomplexan parasites including Plasmodium falciparum and Toxoplasma gondii. Here, a novel ATP-mimetic centered on 1-(pyridin-4-yl) pyrrolidin-2-one (PPL) scaffold has been validated to bind to Toxoplasma gondii PRS and kill toxoplasma parasites. PPL series exhibited potent inhibition at the cellular (T. gondii parasites) and enzymatic (TgPRS) levels compared to the human counterparts. Cell-based chemical mutagenesis was employed to determine the mechanism of action via a forward genetic screen. Tg-resistant parasites were analyzed with wild-type strain by RNA-seq to identify mutations in the coding sequence conferring drug resistance by computational analysis of variants. DNA sequencing established two mutations, T477A and T592S, proximal to terminals of the PPL scaffold and not directly in the ATP, tRNA, or L-pro sites, as supported by the structural data from high-resolution crystal structures of drug-bound enzyme complexes. These data provide an avenue for structure-based activity enhancement of this chemical series as anti-infectives.

Biochemical Structure and Function of TRAPP Complexes in the Cardiac System.

Trafficking protein particle (TRAPP) is well reported to play a role in the trafficking of protein products within the Golgi and endoplasmic reticulum. Dysfunction in TRAPP has been associated with disorders in the nervous and cardiovascular systems, but the majority of literature focuses on TRAPP function in the nervous system solely. Here, we highlight the known pathways of TRAPP and hypothesize potential impacts of TRAPP dysfunction on the cardiovascular system, particularly the role of TRAPP as a guanine-nucleotide exchange factor for Rab1 and Rab11. We also review the various cardiovascular phenotypes associated with changes in TRAPP complexes and their subunits.

Manganese-dependent microRNA trimming by 3'→5' exonucleases generates 14-nucleotide or shorter tiny RNAs.

MicroRNAs (miRNAs) are about 22-nucleotide (nt) noncoding RNAs forming the effector complexes with Argonaute (AGO) proteins to repress gene expression. Although tiny RNAs (tyRNAs) shorter than 19 nt have been found to bind to plant and vertebrate AGOs, their biogenesis remains a long-standing question. Here, our in vivo and in vitro studies show several 3'→5' exonucleases, such as interferon-stimulated gene 20 kDa (ISG20), three prime repair exonuclease 1 (TREX1), and ERI1 (enhanced RNAi, also known as 3'hExo), capable of trimming AGO-associated full-length miRNAs to 14-nt or shorter tyRNAs. Their guide trimming occurs in a manganese-dependent manner but independently of the guide sequence and the loaded four human AGO paralogs. We also show that ISG20-mediated guide trimming makes Argonaute3 (AGO3) a slicer. Given the high Mn2+ concentrations in stressed cells, virus-infected cells, and neurodegeneration, our study sheds light on the roles of the Mn2+-dependent exonucleases in remodeling gene silencing.

A Young Man With Dyspnea.

CASE PRESENTATION: A 27-year-old accountant came to the ED with difficulty walking and progressive weakness of both lower limbs for 4 days' duration. He did not report a history of trauma or fall. He demonstrated no vertigo, headache, neck or back pain, disturbed vision, loss of weight, or weakness in upper limbs. He also reported difficulty breathing, fever, severe abdominal pain, and loose stools of 1 day's duration. His recorded maximum temperature at home was 38.3 °C. The fever subsided with oral paracetamol 500 mg. He did not report having weakness in any limb before the current presentation. He did not have comorbid diabetes mellitus or hypertension. Thirty days before presentation, he experienced fever, cough, and rhinorrhea and received a diagnosis of COVID-19 after reverse-transcriptase polymerase chain reaction testing. At that time, symptoms had been minimal, vitals signs and chest radiography findings were normal, and he had undergone home isolation. He had maintained an oxygen saturation of 98% to 99% as measured on pulse oximetry. He had not received any treatment at that time. His symptoms had lasted for 7 days, and he remained asymptomatic up to the current presentation with paraparesis.

Recent updates in diagnosis and management of drug-resistant tuberculosis in India: A paradigm shift and the way ahead during the COVID-19 crisis.

The recent guidelines on the Programmatic Management of Drug-Resistant Tuberculosis (DR-TB) in India (PMDT) have been released in March 2021 on World TB Day. The new guidelines have considered emerging diagnostic trends including TrueNat, Xpert Mtb/XDR, Next generation sequencing and evaluation for resistance to newer drugs including Bedaquiline (Bdq) and Delamanid. The emerging therapeutic trends include focus on oral shorter Bdq based regimen with phasing out injectables use. The replacement sequence of drugs for DR-TB have also been updated. Updated definitions for pre-XDR, XDR, culture conversion and default have also been added. These guidelines are a paradigm shift which will make treating DR-TB easier and more efficient especially during the ongoing COVID-19 pandemic crisis.

Double drugging of prolyl-tRNA synthetase provides a new paradigm for anti-infective drug development.

Toxoplasmosis is caused by Toxoplasma gondii and in immunocompromised patients it may lead to seizures, encephalitis or death. The conserved enzyme prolyl-tRNA synthetase (PRS) is a validated druggable target in Toxoplasma gondii but the traditional 'single target-single drug' approach has its caveats. Here, we describe two potent inhibitors namely halofuginone (HFG) and a novel ATP mimetic (L95) that bind to Toxoplasma gondii PRS simultaneously at different neighbouring sites to cover all three of the enzyme substrate subsites. HFG and L95 act as one triple-site inhibitor in tandem and form an unusual ternary complex wherein HFG occupies the 3'-end of tRNA and the L-proline (L-pro) binding sites while L95 occupies the ATP pocket. These inhibitors exhibit nanomolar IC50 and EC50 values independently, and when given together reveal an additive mode of action in parasite inhibition assays. This work validates a novel approach and lays a structural framework for further drug development based on simultaneous targeting of multiple pockets to inhibit druggable proteins.

The emerging threat of multisystem inflammatory syndrome in adults (MIS-A) in COVID-19: A systematic review.

BACKGROUND: The exact prevalence of Multisystem Inflammatory Syndrome in Adults (MIS-A) is largely unknown. Vague and multiple definitions and treatment options often add to the confusion on how to label the diagnosis with certainty. OBJECTIVES: The objective of the study was to determine the demographic profile, clinical presentation, laboratory findings and outcomes of MIS-A in COVID-19. METHODS: A systematic review was conducted after registering with PROSPERO. Multiple databases were systematically searched to encompass studies characterizing MIS-A from 1st January 2020 up to 31st August 2021. The inclusion criteria were- to incorporate all published or in press peer-reviewed articles reporting cases of MIS-A. We accepted the following types of studies: case reports, case-control, case series, cross-sectional studies and letters to the editors that incorporated clinical, laboratory, imaging, as well as the hospital course of MIS-A patients. The exclusion criteria for the review were- articles not in English, only abstracts published, no data on MIS-A and articles which have focus on COVID-19, and not MIS-A. Two independent authors screened the articles, extracted the data, and assessed the risk of bias. RESULTS: A total of 53 articles were included in this review with a sample size of 79 cases. Majority of the patients were males (73.4%) with mean age of 31.67±10.02 years. Fever (100%) and skin rash (57.8%) were the two most common presenting symptoms. Echocardiographic data was available for 73 patients of whom 41 (73.2%) had reduced left ventricular ejection fraction. Cardiovascular system was most frequently involved (81%) followed by gastrointestinal (73.4%) and mucocutaneous (51.9%) involvement. Anti-inflammatory therapies used in treatment included steroids (60.2%), intravenous immunoglobulin (37.2%) and biologics (10.2%). Mean duration of the hospital stay was 11.67±8.08 days. Data regarding the outcomes was available for all 79 subjects of whom 4 (5.1%) died during course of hospital stay. CONCLUSIONS: Emergence of MIS-A calls for further large-scale studies to establish standard case definitions and definite treatment guidelines.

Management of bronchial asthma in 2021.

To The Editor, The Global Initiative for Asthma (GINA) 2021 update was published on the 28th of April, 2021. There are significant changes, including treatment of mild asthma, the role of azithromycin, treatment of asthma in COVID-19 times, and role of biologics...