Publications by authors named "Luciane A A Leon"

MicroRNAs (miRNAs) can act as biomarkers and descriptors of the association between infections and other diseases, such as hepatitis and COVID-19. This study aims to investigate the role of miRNA serum expression according to laboratory data concerning hepatitis and COVID-19. Seventy individuals recruited in Southern and Southeastern Brazil donated serum samples and were divided into four groups: (i) 20 negative subjects, (ii) 20 presenting hepatitis, (iii) 19 with COVID-19 and (iv) 11 with hepatitis and COVID-19.

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  • The study explores the link between high plasma levels of neurofilament light chain (pNfL) and neurocognitive symptoms in patients with Long COVID, indicating that SARS-CoV-2 can lead to long-term brain effects even after mild illness.
  • A group of 63 Long COVID patients underwent neurocognitive assessments, revealing that those with cognitive issues and fatigue had significantly higher pNfL levels compared to those without these symptoms.
  • The findings suggest that measuring pNfL could help identify individuals at risk for CNS involvement and guide their need for ongoing monitoring and treatment for neurocognitive dysfunction post-COVID.
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Hepatitis E virus (HEV) infection has been demonstrated in various animal species; those recognized as potential zoonotic reservoirs pose a considerable risk to public health. In Brazil, HEV-3 is the only genotype identified in humans and swine nationwide, in a colony-breeding cynomolgus monkey and, recently, in bovines and capybara. There is no information regarding HEV exposure in the equine population in Brazil.

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Herpesvirus is associated with various neurological disorders and a specific diagnosis is associated with a better prognosis. MicroRNAs (miRNAs) are potential diagnostic and prognostic biomarkers of neurological diseases triggered by herpetic infection. In this review, we discuss miRNAs that have been associated with neurological disorders related to the action of herpesviruses.

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Human herpesviruses (HHVs) can establish latency and be reactivated, also are neurotropic viruses that can trigger neurological disorders. HHV-6 is a herpesvirus that is associated with neurological disorders. Studies have reported the detection of HHV-6 in patients with COVID-19 and neurological manifestations.

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Multiple sclerosis (MS) is a chronic neuroinflammatory and neurodegenerative disease of the central nervous system (CNS). The etiology of MS is not well understood, but it's likely one of the genetic and environmental factors. Approximately 85% of patients have relapsing-remitting MS (RRMS), while 10-15% have primary progressive MS (PPMS).

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  • Cognitive dysfunction is commonly observed in patients recovering from COVID-19, with the exact mechanisms not fully understood.
  • Research indicates that the Spike protein of SARS-CoV-2 can affect brain function, as shown in mouse studies where infusion of this protein leads to cognitive impairment similar to post-COVID-19 syndrome.
  • Key findings highlight that TLR4 signaling plays a crucial role in memory dysfunction related to the Spike protein, suggesting it could be a target for addressing long-term cognitive issues in individuals after COVID-19.
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  • The study investigates the effectiveness of using oral fluid (OF) samples for diagnosing and characterizing parvovirus B19 genotypes during erythema infectiosum outbreaks, where previous research focused mainly on serological diagnosis.
  • Using paired serum and oral fluid samples from patients, researchers found that quantitative PCR (qPCR) was more effective than conventional PCR (cPCR) for detecting B19-DNA, although OF samples generally had a lower viral load compared to serum.
  • The research highlights that while PCR-based methods may miss about 50% of B19-DNA in OF samples compared to serum, analyzing the genome from these non-invasive samples can provide valuable insights into the genetic diversity of circulating B19 strains.
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  • A study investigated the prevalence of herpesvirus in 53 COVID-19 patients, revealing that 79.2% had at least one type of herpesvirus, with HHV-6, cytomegalovirus, and HHV-7 being the most common.
  • The research found a significant correlation between high SARS-CoV-2 viral loads and the presence of herpes simplex virus 1, and 26.4% of patients with coinfections exhibited neurological symptoms.
  • Although coinfection did not result in worse overall outcomes, there was a noteworthy association between HHV-6 detection and neurological changes in patients.
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The emergence of the COVID-19 pandemic resulted in an unprecedented need for RT-qPCR-based molecular diagnostic testing, placing a strain on the supply chain and the availability of commercially available PCR testing kits and reagents. The effect of limited molecular diagnostics-related supplies has been felt across the globe, disproportionally impacting molecular diagnostic testing in developing countries where acquisition of supplies is limited due to availability. The increasing global demand for commercial molecular diagnostic testing kits and reagents has made standard PCR assays cost prohibitive, resulting in the development of alternative approaches to detect SARS-CoV-2 in clinical specimens, circumventing the need for commercial diagnostic testing kits while mitigating the high-demand for molecular diagnostics testing.

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B19V has been proposed as an etiologic agent for hepatitis, mainly in children, but this is a rare clinical occurrence. In this article, we report a case of non-A-E acute liver failure in an immunocompetent child with B19 infection. The clinical findings of severe anemia and pancytopenia combined with the detection of anti-B19 Immunoglobulin G (IgG), B19 DNA and B19 mRNA in liver indicate a persistent infection and suggest a diagnosis of parvovirus B19-associated acute liver failure.

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Background: This paper describes the transmission of hepatitis A virus (HAV) to two blood recipients from a healthy donor that later presented to the blood bank with jaundice.

Methods: The RNA of HAV was detected by qualitative nested reverse transcription polymerase chain reaction (nested RT-PCR) and quantified by real-time RT-PCR. HAV RNA samples were genotyped by direct sequencing of PCR products.

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This study was conducted to analyse the course and the outcome of the liver disease in the co-infected animals in order to evaluate a possible synergic effect of human parvovirus B19 (B19V) and hepatitis A virus (HAV) co-infection. Nine adult cynomolgus monkeys were inoculated with serum obtained from a fatal case of B19V infection and/or a faecal suspension of acute HAV. The presence of specific antibodies to HAV and B19V, liver enzyme levels, viraemia, haematological changes, and necroinflammatory liver lesions were used for monitoring the infections.

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