Publications by authors named "Guido Van Marle"

Modern sequencing instruments bring unprecedented opportunity to study within-host viral evolution in conjunction with viral transmissions between hosts. However, no computational simulators are available to assist the characterization of within-host dynamics. This limits our ability to interpret epidemiological predictions incorporating within-host evolution and to validate computational inference tools.

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Co-existing chronic hepatitis B virus (CHB) infection and metabolic dysfunction associated steatotic liver disease (MASLD) can exert complex effects on hepatic metabolism, requiring mechanistic study. CHB participants were assessed for MASLD and the impact of hepatic steatosis/metabolic syndrome (MetS) on novel viral and immunological markers. In this prospective, cohort study, untreated CHB subjects were assessed for liver disease by non-invasive tests (i.

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To achieve a virological cure for hepatitis B virus (HBV), innovative strategies are required to target the covalently closed circular DNA (cccDNA) genome. Guanine-quadruplexes (G4s) are a secondary structure that can be adopted by DNA and play a significant role in regulating viral replication, transcription, and translation. Antibody-based probes and small molecules have been developed to study the role of G4s in the context of the human genome, but none have been specifically made to target G4s in viral infection.

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Understanding plant microbes' intimate relationship and search for beneficial microbes is a sustainable alternative to improve plant growth and yield under a wide range of biotic and abiotic stress conditions. More than 20% of the total global agricultural land is affected by salinity. High salinity challenges crop plants by affecting several metabolic pathways and decreasing plant growth and yield.

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The COVID-19 pandemic has illustrated the importance of infection tracking. The role of asymptomatic, undiagnosed individuals in driving infections within this pandemic has become increasingly evident. Modern phylogenetic tools that take into account asymptomatic or undiagnosed individuals can help guide public health responses.

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The infectious bronchitis virus (IBV) 4/91 was one of the common IBV variants isolated in Eastern Canada between 2013 and 2017 from chicken flocks showing severe respiratory and production problems. We designed an in vivo experiment, using specific pathogen free (SPF) chickens, to study the pathogenesis of, and host response to, Canadian (CAN) 4/91 IBV infection. At one week of age, the chickens were infected with 4/91 IBV/Ck/Can/17-038913 isolate.

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Approximately 250 million people worldwide are chronically infected with the hepatitis B virus (HBV) and are at increased risk of developing cirrhosis and hepatocellular carcinoma. The HBV genome persists as covalently closed circular DNA (cccDNA), which serves as the template for all HBV mRNA transcripts. Current nucleos(t)ide analogs used to treat HBV do not directly target the HBV cccDNA genome and thus cannot eradicate HBV infection.

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Background: Occult hepatitis B (OHB) is a major concern in HIV infected patients as it associates with a high risk of HBV reactivation and disease progression. However, data on the prevalence of OHB among HIV positive patients in Ethiopia is lacking. This study aims to determine the prevalence of OHB in HBV/HIV co-infected patients from Gondar, Ethiopia.

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Background: The greatest risk of chronic hepatitis B (CHB) is from mother-to-child transmission. Approximately 20% of individuals in sub-Saharan Africa are hepatitis B virus (HBV) surface antigen-positive (HBsAg+), but the prevalence of occult hepatitis B (OHB) is unknown. Aim: This study investigated CHB and OHB prevalence and viral variants in a cohort of pregnant women in Gondor, Ethiopia.

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A novel reverse-transcriptase loop mediated amplification (RT-LAMP) method targeting genes encoding the Spike (S) protein and RNA-dependent RNA polymerase (RdRP) of SARS-CoV-2 has been developed. The LAMP assay achieves a comparable limit of detection (25-50 copies per reaction) to commonly used RT-PCR protocols using clinical samples quantified by digital droplet PCR. Precision, cross-reactivity, inclusivity, and limit of detection studies were performed according to regulatory standards.

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Background: Chronic hepatitis B virus (HBV) infection is the leading cause of hepatocellular carcinoma (HCC) world-wide. HBV variants, particularly the G1896A pre-core (PC) and A1762T/G1764A basal core promoter (BCP) mutations, are established risk factors for cirrhosis and HCC, but the molecular biological basis is unclear. We hypothesized that these variants result in differential HBV replication, APOBEC3 family expression, and cytokine/chemokine expression.

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Background: Meningioma, a most common brain tumor, has a high rate of recurrence. Tumor-associated macrophages (TAMs) are the most abundant immune cell type in meningioma. TAMs display functional phenotypic diversity and may establish either an inflammatory and anti-tumoral or an immunosuppressive and pro-tumoral microenvironment.

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Toll-like receptor (TLR) 7 ligand, resiquimod, has been studied as an adjuvant and antiviral agent against several pathogens in chicken. Yet, the effectiveness of resiquimod against infectious bronchitis virus (IBV) infection has not been evaluated. In this study, we investigated the effectiveness of resiquimod delivered pre-hatch (in ovo) against IBV infection post-hatch identifying key mechanisms involved in resiquimod driven immune activation.

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The hepatitis B virus (HBV) is a major cause of hepatocellular carcinoma (HCC), partly driven by viral integration and specific oncogenic HBV variants. However, the biological significance of HBV genomes within lymphoid cells (i.e.

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HIV; Canada; molecular phylogenetics; viral evolution; person-to-person transmission inference; transmission network; summary statistics.

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In March 2018, the Canadian Association for HIV Research (CAHR) and Canadian Foundation for Infectious Diseases (CFID) collaborated to conduct a workshop targeted to mid-career virology researchers. Key objectives of the workshop included 1) sharing knowledge and expertise cutting across various viral diseases, 2) developing collaborations as we anticipate the next wave of suppressive and curative treatment for HIV, HBV, CMV, and other viral diseases, and 3) providing insights, advice, and "food for thought" as participants advance to mid- and later phases of their research careers. This article reports on the key topics contemplated including scientific misinformation within the public realm, network building, interdisciplinary collaboration, mentorship, and communicating with decision makers.

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Background: Sickle cell anaemia (SCA) is a hereditary blood disorder caused by a single mutation in the haemoglobin gene. The disease burden of SCA is highest in Nigeria. The allele specific polymerase chain reaction (ASPCR) method is applicable for the direct detection of known single nucleotide polymorphisms (SNPs).

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Meningioma is the most common brain tumor in adults. Surgical resection remains the primary treatment. No chemotherapy exists.

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The in ovo delivery of cytosine-guanosine (CpG) oligodeoxynucleotides (ODNs) protects chickens against many bacterial and viral infections, by activating the toll-like receptor (TLR)21 signaling pathway. Although the delivery of CpG ODNs in ovo at embryo day (ED) 18 has been shown to reduce infectious bronchitis virus (IBV) loads in embryonic chicken lungs pre-hatch, whether in ovo delivered CpG ODNs are capable of protecting chickens against a post-hatch challenge is unknown. Thus, our objectives were to determine the protective effect of the in ovo delivery of CpG ODNs at ED 18 against IBV infection encountered post-hatch and, then, to investigate the mechanisms of protection.

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Over 250 million people are infected chronically with hepatitis B virus (HBV), the leading cause of liver cancer worldwide. HBV persists, due, in part, to its compact, stable minichromosome, the covalently-closed, circular DNA (cccDNA), which resides in the hepatocytes' nuclei. Current therapies target downstream replication products, however, a true virological cure will require targeting the cccDNA.

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Impressive advances have been made in the treatment and management of HIV-1 infected individuals. Combination antiretroviral therapy (cART) has turned HIV-1 infection from an almost invariable deadly infectious disease, to a lifelong manageable infectious disease. However, a cure or vaccine has not been forthcoming.

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Background: Oropharyngeal Squamous Cell Carcinoma (OPSCC) is increasing in incidence despite a decline in traditional risk factors. Human Papilloma Virus (HPV), specifically subtypes 16, 18, 31 and 35, has been implicated as the high-risk etiologic agent. HPV positive cancers have a significantly better prognosis than HPV negative cancers of comparable stage, and may benefit from different treatment regimens.

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Background: In sub-Saharan Africa, the hepatitis B virus (HBV) and human immunodeficiency virus (HIV) infections are endemic. Although there has been great progress in HIV care, universal HBV vaccination and care is lacking. In this study, we aimed to determine the prevalence of HBV, HBV genotypes, and drug resistance mutations in dual infected cases in a cohort of HIV patients in Northwest Ethiopia.

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