Publications by authors named "George A V Silva"

BCR::ABL1-negative myeloproliferative neoplasms are hematopoietic disorders characterized by panmyelosis. JAK2 V617F is a frequent variant in these diseases and often occurs in the 46/1 haplotype. The G allele of rs10974944 has been shown to be associated with this variant, specifically its acquisition, correlations with familial cases, and laboratory alterations.

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(dbSNP: ) is the most frequent and most-studied variant in negative myeloproliferative neoplasms and in the gene. The present study aimed to molecularly characterize variants in the complete coding region of the gene in patients with negative chronic myeloproliferative neoplasms. The study included 97 patients with negative myeloproliferative neoplasms, including polycythemia vera (n=38), essential thrombocythemia (n=55), and myelofibrosis (n=04).

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Objective: To describe clinical, epidemiological and management information on cases of acute Chagas disease (ACD) by oral transmission in the state of Amazonas in western Amazon.

Methods: Manual and electronic medical records of patients diagnosed with ACD at the Fundação de Medicina Tropical Doutor Heitor Vieira Dourado (FMT-HVD) were included.

Results: There were 147 cases of acute CD registered from 10 outbreaks that occurred in the state of Amazonas between 2004 and 2022.

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Haplotype 46/1 (GGCC) consists of a set of genetic variations distributed along chromosome 9p.24.1, which extend from the Janus Kinase 2 gene to Insulin like .

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The immunopathology associated with Leishmaniasis is a consequence of inflammation. Upon infection with , the type of host-immune response is determinant for the clinical manifestations that can lead to either self-healing or chronic disease. Multiple pathways may determine disease severity.

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Article Synopsis
  • Chagas disease is caused by the protozoan Trypanosoma cruzi, with seven identified lineages (TcI to TcVI and TcBat).
  • Domestic dogs serve as important reservoirs for T. cruzi, helping in understanding the epidemiology of the disease.
  • This study documents the first case of Chagas disease in a dog from Manaus, Brazil, infected with T. cruzi lineage TcIV, aiming to raise awareness among veterinarians and public health officials.
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Background: Interferon-γ (IFN-γ) plays an important role in the control of Leishmania infection. Blockade of IFN-γ signaling in mice increases lesion size and parasite load. In endemic areas of Leishmaniasis, only a fraction of the population develop the disease.

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Nod-like Receptor Protein3 (NLRP3) inflammasome in macrophages infected with Leishmania sp. enhances the secretion of IL-1β. Excess IL-1β production is linked to disease severity in patients with cutaneous leishmaniasis (CL) caused by L.

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In the Brazilian Amazon, the suspected source of infection in an outbreak of acute Chagas disease involving 10 patients was Euterpe oleracea (açaí berry) juice. Patient blood and juice samples contained Trypanosoma cruzi TcIV, indicating oral transmission of the Chagas disease agent.

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Background: The resistance of Plasmodium vivax to chloroquine has become an obstacle to control strategies based on the use of anti-malarials. The current study investigated the association between P. vivax CQ-resistance in vivo with copy number variation and mutations in the promoter region in pvcrt-o and pvmdr1 genes.

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Tuberculosis (TB), caused by mycobacterial species of the complex, is a serious global health issue. Brazil is among the 22 countries with the highest number of TB cases, and the state of Amazonas has the highest incidence of TB cases in the country. Toll-like receptors (TLRs) are important pattern recognition receptors of the innate immunity and play a key role in orchestrating an effective immune response.

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Background: Infection with Zika virus (ZIKV) manifests in a broad spectrum of disease ranging from mild illness to severe neurological complications and little is known about Zika immunopathogenesis.

Objectives: To define the immunologic biomarkers that correlate with acute ZIKV infection.

Methods: We characterized the levels of circulating cytokines, chemokines, and growth factors in 54 infected patients of both genders at five different time points after symptom onset using microbeads multiplex immunoassay; comparison to 100 age-matched controls was performed for statistical analysis and data mining.

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Background: Zika virus is an emerging arbovirus of the family Flaviviridae and genus Flavivirus that until 2007 was restricted to a few cases of mild illness in Africa and Asia.

Case Presentation: We report a case of atrial fibrillation disclosed during an acute Zika virus infection in a 49-year-old man. Different biological samples were analyzed for the molecular diagnosis of Zika by real-time PCR, however only the saliva specimen was positive.

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Group A rotaviruses are the main causative agent of infantile gastroenteritis. The segmented nature of the viral genome allows reassortment of genome segments, which can generate genetic variants. In this study, we characterized the diversity of the VP7, VP4 (VP8*), VP6, NSP4, and NSP5 genes of the rotaviruses that circulated from 2005 to 2011 in the Triângulo Mineiro (TM) region of Brazil.

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Article Synopsis
  • Chagas disease in the Amazon primarily involves the discrete typing units (DTUs) TcI and TcIV, linked to both acute oral transmission and chronic cases.
  • Blood cultures and xenodiagnosis in 36 seropositive patients revealed no immediate infection, yet molecular analysis identified T. cruzi in 36% of triatomine fecal samples, mainly as DTU TcI with various haplotypes.
  • The study concludes that DTU TcI, commonly associated with acute cases, is also implicated in chronic Chagas disease in certain areas of Amazonas, Brazil.
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Dengue is the most important arboviral disease worldwide. We report the complete genome sequence of a dengue virus serotype 4, genotype II strain isolated in 2010 from a patient with classical dengue fever in Boa Vista, Roraima, Brazil.

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