Binding kinetics of highly mutated HIV-1 subtype C protease inhibition by Lopinavir and Darunavir in the face of altered conformational dynamics.

Highly mutated HIV-1 protease (PR) compromises the efficacy of lopinavir (LPV) and darunavir (DRV) used to formulate salvage regimens in HIV/AIDS management. Here, we report the kinetics of inhibition of lopinavir (LPV) and darunavir (DRV) on highly mutated South African HIV-1 subtype C PR obtained from clinical isolates. The wild-type and mutant South African HIV-1 subtype C PR were cloned and purified.

An Integrated Rapid Response Model for Pediatric Patients Requiring In-Patient Medical Stabilization: Lessons Learned to Enable Regional Capacity Building.

There was an unprecedented surge in admissions for medical stabilization of pediatric patients with eating disorders during the COVID-19 pandemic in Ontario. Eleven hospitals established an integrated rapid response model to ensure timely in-patient access for these patients. This population was cared for in re-allocated community hospital beds as a result of engaging hospital leadership, strengthening partnerships, consulting experts, leveraging existing resources and developing regional bed access strategies.

Early Results of an Initiative to Assess Exposure to Firearm Violence in Ambulatory Care: Descriptive Analysis of Electronic Health Record Data.

Background:  Current research on firearm violence is largely limited to patients who received care in emergency departments or inpatient acute care settings or who died. This is because standardized disease classification codes for firearm injury only represent bodily trauma. As a result, research on pathways and health impacts of firearm violence is largely limited to people who experienced acute bodily trauma and does not include the estimated millions of individuals who were exposed to firearm violence but did not sustain acute injury.

The (Re-)Emergence and Spread of Viral Zoonotic Disease: A Perfect Storm of Human Ingenuity and Stupidity.

Diseases that are transmitted from vertebrate animals to humans are referred to as zoonotic diseases. Although microbial agents such as bacteria and parasites are linked to zoonotic events, viruses account for a high percentage of zoonotic diseases that have emerged. Worryingly, the 21st century has seen a drastic increase in the emergence and re-emergence of viral zoonotic disease.

Skeletal Muscle Mitochondrial Respiration and Exercise Intolerance in Patients With Heart Failure With Preserved Ejection Fraction.

Importance: The pathophysiology of exercise intolerance in patients with heart failure with preserved ejection fraction (HFpEF) remains incompletely understood. Multiple lines of evidence suggest that abnormal skeletal muscle metabolism is a key contributor, but the mechanisms underlying metabolic dysfunction remain unresolved.

Objective: To evaluate the associations of skeletal muscle mitochondrial function using respirometric analysis of biopsied muscle fiber bundles from patients with HFpEF with exercise performance.

Identifying the research, advocacy, policy and implementation needs for the prevention and management of respiratory syncytial virus lower respiratory tract infection in low- and middle-income countries.

Introduction: The high burden of respiratory syncytial virus (RSV) infection in young children disproportionately occurs in low- and middle-income countries (LMICs). The PROUD (Preventing RespiratOry syncytial virUs in unDerdeveloped countries) Taskforce of 24 RSV worldwide experts assessed key needs for RSV prevention in LMICs, including vaccine and newer preventive measures.

Methods: A global, survey-based study was undertaken in 2021.

Characterization of a Near Full-Length Hepatitis E Virus Genome of Subtype 3c Generated from Naturally Infected South African Backyard Pigs.

Eight genotypes of the hepatitis E virus (Orthohepevirus A; HEV) designated HEV-1 to HEV-8 have been reported from various mammalian hosts. Notably, domestic pigs and wild boars are the natural reservoirs of HEV-3 and HEV-4 genotypes with zoonotic propensity. Since HEV infection in domestic pigs is usually subclinical, it may remain undetected, facilitating zoonotic spillover of HEV to the exposed human populations.

Metagenomic Analysis of RNA Fraction Reveals the Diversity of Swine Oral Virome on South African Backyard Swine Farms in the uMgungundlovu District of KwaZulu-Natal Province.

Numerous RNA viruses have been reported in backyard swine populations in various countries. In the absence of active disease surveillance, a persistent knowledge gap exists on the diversity of RNA viruses in South African backyard swine populations. This is the first study investigating the diversity of oral RNA virome of the backyard swine in South Africa.

The impact of the COVID-19 pandemic on children with medical complexity.

Background: Descriptions of the COVID-19 pandemic's indirect consequences on children are emerging. We aimed to describe the impacts of the pandemic on children with medical complexity (CMC) and their families.

Methods: A one-time survey of Canadian paediatricians using the Canadian Paediatric Surveillance Program (CPSP) was conducted in Spring 2021.

The HIV-1 Gag Protein Displays Extensive Functional and Structural Roles in Virus Replication and Infectivity.

Once merely thought of as the protein responsible for the overall physical nature of the human immunodeficiency virus type 1 (HIV-1), the Gag polyprotein has since been elucidated to have several roles in viral replication and functionality. Over the years, extensive research into the polyproteins' structure has revealed that Gag can mediate its own trafficking to the plasma membrane, it can interact with several host factors and can even aid in viral genome packaging. Not surprisingly, Gag has also been associated with HIV-1 drug resistance and even treatment failure.

An overview of influenza A virus genes, protein functions, and replication cycle highlighting important updates.

The recent research findings on influenza A virus (IAV) genome biology prompted us to present a comprehensive overview of IAV genes, protein functions, and replication cycle. The eight gene segments of the IAV genome encode 17 proteins, each having unique functions contributing to virus fitness in the host. The polymerase genes are essential determinants of IAV pathogenicity and virulence; however, other viral components also play crucial roles in the IAV replication, transmission, and adaptation.

A systematic review of influenza A virus prevalence and transmission dynamics in backyard swine populations globally.

Background: Backyard swine farming is critical to generating subsistence and food security in rural and peri-urban households in several developing countries. The objective of this systematic review was to analyze the molecular and serological prevalence of influenza A virus (IAV) in backyard swine populations globally.

Results: We identified 34 full-text research articles in NCBI-PubMed and Google Scholar databases that have reported IAV sero- and/or virological prevalence in backyard swine up to 11 July 2021.

Review of genome sequencing technologies in molecular characterization of influenza A viruses in swine.

The rapidly evolving antigenic diversity of influenza A virus (IAV) genomes in swine makes it imperative to detect emerging novel strains and track their circulation. We analyzed in our review the sequencing technologies used for subtyping and characterizing swine IAV genomes. Google Scholar, PubMed, and International Nucleotide Sequence Database Collaboration (INSDC) database searches identified 216 studies that have utilized Sanger, second-, and third-generation sequencing techniques to subtype and characterize swine IAV genomes up to 31 March 2021.

Deciphering transmission dynamics and spillover of avian influenza viruses from avian species to swine populations globally.

Genome sequences of eleven avian influenza virus (AIV) subtypes have been reported in swine populations from seven countries until August 2020. To unravel the transmission dynamics and spillover events of AIVs from avian reservoirs to swine, full-length hemagglutinin (HA) sequences of AIV subtypes (n = 11) reported from various avian species and swine were retrieved from the 'Influenza Research Database'. Phylogenetic analysis identified closely related avian and swine AIV sequences suggesting potential spillover events from multiple domestic and wild avian species, including chicken, duck, pigeon, goose, quail, and aquatic birds to swine.

Structural effects of HIV-1 subtype C integrase mutations on the activity of integrase strand transfer inhibitors in South African patients.

HIV-1 integrase enzyme is responsible for the integration of viral DNA into the host genomic DNA. Integrase strand transfer inhibitors (INSTIs) are highly potent antiretroviral agents that inhibit this process, and are internationally approved for the treatment of both naïve and treated HIV-1 patients. However, their long-term efficacy is threatened by development of drug resistance strains resulting in resistance mutations.

Understanding the co-evolutionary molecular mechanisms of resistance in the HIV-1 Gag and protease.

Due to high human immunodeficiency virus type 1 (HIV-1) subtype C infections coupled with increasing antiretroviral treatment failure, the elucidation of complex drug resistance mutational patterns arising through protein co-evolution is required. Despite the inclusion of potent protease inhibitors Lopinavir (LPV) and Darunavir (DRV) in second- and third-line therapies, many patients still fail treatment due to the accumulation of mutations in protease (PR) and recently, Gag. To understand the co-evolutionary molecular mechanisms of resistance in the HIV-1 PR and Gag, we performed 100 ns molecular dynamic simulations on multidrug resistant PR's when bound to LPV, DRV or a mutated A431V NC|p1 Gag cleavage site (CS).

HIV-1 integrase strand transfer inhibitors: a review of current drugs, recent advances and drug resistance.

Antiretroviral therapy has been imperative in controlling the human immunodeficiency virus (HIV) epidemic. Most low- and middle-income countries have used nucleoside reverse transcriptase inhibitors (NRTIs), non-nucleoside reverse transcriptase inhibitors (NNRTIs) and protease inhibitors extensively in the treatment of HIV. However, integrase strand transfer inhibitors (INSTIs) are becoming more common.

Acquired HIV-1 Protease Conformational Flexibility Associated with Lopinavir Failure May Shape the Outcome of Darunavir Therapy after Antiretroviral Therapy Switch.

Understanding the underlying molecular interaction during a therapy switch from lopinavir (LPV) to darunavir (DRV) is essential to achieve long-term virological suppression. We investigated the kinetic and structural characteristics of multidrug-resistant South African HIV-1 subtype C protease (HIV-1 PR) during therapy switch from LPV to DRV using enzyme activity and inhibition assay, fluorescence spectroscopy, and molecular dynamic simulation. The HIV-1 protease variants were from clinical isolates with a combination of drug resistance mutations; MUT-1 (M46I, I54V, V82A, and L10F), MUT-2 (M46I, I54V, L76V, V82A, L10F, and L33F), and MUT-3 (M46I, I54V, L76V, V82A, L90M, and F53L).

Design and synthesis of quinoline-pyrimidine inspired hybrids as potential plasmodial inhibitors.

Presently, artemisinin-based combination therapy (ACT) is the first-line therapy of Plasmodium falciparum malaria. With the emergence of malaria parasites that are resistant to ACT, alternative antimalarial therapies are urgently needed. In line with this, we designed and synthesised a series of novel N-(7-chloroquinolin-4-yl)-N'-(4,6-diphenylpyrimidin-2-yl)alkanediamine hybrids (6a-7c) and evaluated their inhibitory activity against the NF54 chloroquine-susceptible strain as a promising class of antimalarial compounds.

Recombinant expression of HIV-1 protease using soluble fusion tags in Escherichia coli: A vital tool for functional characterization of HIV-1 protease.

HIV-1 protease expression in the laboratory is demanding because of its high cytotoxicity, making it difficult to express in bacterial expression systems such as Escherichia coli. To overcome these challenges, HIV-1 protease fusion with solubility enhancing tags helps to mitigate its cytotoxic effect and drive its expression as a soluble protein. Therefore, this review focuses on the expression of bioactive HIV-1 protease using solubility-enhancing fusion tags in Escherichia coli and summarises the characteristic features of the different common fusion tags that have been used in the expression of HIV-1 protease.

Modulatory influences of antiviral bioactive compounds on cell viability, mRNA and protein expression of cytochrome P450 3A4 and P-glycoprotein in HepG2 and HEK293 cells.

The induction of cytochrome P450 3A4 (CYP3A4) and P-glycoprotein (ABCB1) influence drug plasma, and eventually decreases the drugs' therapeutic effects. The effects of Plant-derived compounds (PCs) on drug-metabolising proteins are largely unknown. This study investigated the cytotoxicity, cell viability profiles and regulatory influences of four PCs (epigallocatechin gallate (EGCG), kaempferol-7-glucoside (K7G), luteolin (LUT) and ellagic acid (EGA)) on the mRNA and protein expressions of CYP3A4 and ABCB1 in HepG2 and HEK293 cells.

Vulnerable targets in HIV-1 Pol for attenuation-based vaccine design.

Identification of viral immune escape mutations that compromise HIV's ability to replicate may aid rational attenuation-based vaccine design. Previously we reported amino acids associated with altered viral replication capacity (RC) from a sequence-function analysis of 487 patient-derived RT-integrase sequences. In this study, site-directed mutagenesis experiments were performed to validate the effect of these mutations on RC.

Molecular dynamic mechanism(s) of inhibition of bioactive antiviral phytochemical compounds targeting cytochrome P450 3A4 and P-glycoprotein.

P-glycoprotein (ABCB1) and cytochrome P450 3A4 (CYP3A4) metabolize almost all known human immunodeficiency virus' protease inhibitor drugs (PIs). Over induction of these proteins' activities has been linked to rapid metabolism of PIs which are then pumped out of the circulatory system, eventually leading to drug-resistance in HIV-positive patients. This study aims to determine, with the use of computational tools, the inhibitory potential of four phytochemical compounds (PCs) (epigallocatechin gallate (EGCG), kaempferol-7-glucoside (K7G), luteolin (LUT) and ellagic acid (EGA)) in inhibiting the activities of these drug-metabolizing proteins.

A Systematic Review Analyzing the Prevalence and Circulation of Influenza Viruses in Swine Population Worldwide.

The global anxiety and a significant threat to public health due to the current COVID-19 pandemic reiterate the need for active surveillance for the zoonotic virus diseases of pandemic potential. Influenza virus due to its wide host range and zoonotic potential poses such a significant threat to public health. Swine serve as a "mixing vessel" for influenza virus reassortment and evolution which as a result may facilitate the emergence of new strains or subtypes of zoonotic potential.