Publications by authors named "Romulo Pessoa-e-Silva"

SARS-CoV-2 virus emerged as a new threat to humans and spread around the world, leaving a large death toll. As of January 2023, Brazil is among the countries with the highest number of registered deaths. Nonpharmacological and pharmacological interventions have been heterogeneously implemented in the country, which, associated with large socioeconomic differences between the country regions, has led to distinct virus spread dynamics.

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Chagas disease (CD), caused by the protozoan Trypanosoma cruzi (T. cruzi), affects millions of people worldwide. Polymerase Chain Reaction (PCR) and real-time quantitative PCR (qPCR) have been used as tools to monitor parasitic levels in the bloodstream of individuals exposed to infection, thus enabling the monitoring of relapses and the effectiveness of therapy, for example.

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Article Synopsis
  • The study evaluated the effectiveness of a rapid antigen test for diagnosing COVID-19 during an Omicron wave in Brazil, involving 347 individuals from a public testing center.
  • The rapid test showed an overall sensitivity of 80.5% and a high specificity of 99.2%, with performance varying based on viral load levels (higher sensitivity with lower Ct values).
  • The results suggest that the rapid antigen test is a reliable option for COVID-19 diagnosis in situations where PCR testing may be limited, especially in areas with high disease prevalence.
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  • Researchers assessed immune response profiles in SARS-CoV-2 infected patients by examining 71 biomarkers across different clinical groups: asymptomatic, mild, and severe cases.
  • They found that certain angiogenesis and cardiovascular disease biomarkers were significantly elevated in severe cases compared to the other groups, indicating distinct immune profiles.
  • The study highlights important differences in cytokines and chemokines among patients, providing insights into potential prognostic markers for understanding disease severity in COVID-19 infections.
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American cutaneous leishmaniasis (ACL) may present different clinical manifestations, immune and therapeutic responses, depending on the Leishmania species, as well as inoculum size and factors inherent to the affected individual. Thus, the aim of this study was to carry out clinical-therapeutic follow-up of Brazilian patients with ACL caused by different Leishmania species. Between 2015 and 2018, patients with ACL from Amazonas and Pernambuco states (Brazil) were submitted to blood collection before and after treatment.

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New therapeutic strategies for visceral leishmaniasis (VL) have been studied, and the development of an immunotherapeutic agent that modulates the host's immune response is necessary. The aim of this study was to evaluate the bioactive extracts of photosynthetic microorganisms (PMs) for their leishmanicidal/leishmanistatic and immunomodulatory potentials. Bioactive extracts from PMs ( and ) were obtained by sonication.

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The maintenance of SARS-Cov-2 RNA samples poses a new challenge for laboratories and researchers. In addition, it is a requirement in order to identify what strain of the new coronavirus is predominant in a region, for instance. Therefore, it is a must to keep the quality and viability of stored RNA to respond to this and other valid questions.

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Introduction: Herein, the authors describe a simple enhancement to a commercial rapid DNA extraction kit based on simple viral lysis for detecting COVID-19 via RT-qPCR.

Methods: After testing several different modifications, the adapted protocol with the best results in preliminary experiments was statistically evaluated in comparison with an automated robotic protocol.

Results: Processing and testing of 119 nasopharyngeal samples ultimately yielded near-perfect agreement with the automated protocol (κ = 0.

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Canine visceral leishmaniasis (CVL) is a zoonotic disease of high lethality caused by Leishmania infantum in the Americas. In the infected dog, the amastigotes are scarce in blood, especially in the late phase of the disease. This study aimed to report a rare case of L.

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The development and application of safe and effective immunoprophylactic/immunotherapeutic agents against canine visceral leishmaniasis (CanL) have been pointed out as the only means for the real control of the disease. Thus, this study aimed to evaluate the cellular immune response of dogs, elicited by the new recombinant proteins of , Lci10 and Lci13, in order to investigate their potential for vaccinology. Twenty-four dogs were submitted to clinical, parasitological, serological and molecular tests, and then separated into two study groups: 12 infected (InD) and 12 non-infected dogs (NInD), and six of each group were directed for Lci10 and Lci13 evaluation.

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Introduction: Brazil has a high number of cases of American cutaneous leishmaniasis (ACL) in the north and northeast regions. Therefore, continuous surveillance of environmental and socioeconomic factors in endemic areas is needed to develop strategic control measures. This study aimed to describe the clinical and epidemiological profiles of patients with ACL.

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Background: American cutaneous leishmaniasis (ACL) is caused by different Leishmania parasites, which stimulate and direct the immune response against the infection.

Objective: To evaluate the TaqMan probe technology applicability to diagnose and identifying of Leishmania spp. related to the ACL etiology.

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In Brazil, the main strategy adopted to contain Visceral Leishmaniasis (VL) is the controversial culling of dogs with reagent serology for Canine VL (CVL). Despite there are studies showing that significant reduction of human cases has not been observed, as well as there are works demonstrating the occurrence of false-positive results in the confirmatory test, the protocol has been maintained. Researches that can reinforce the existence and persistence of this problem, as well as bring concrete alternatives are pivotal.

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Introduction: Herein, we assessed the seroprevalence and spatial distribution of Leishmania infantum in dogs in Garanhuns, Northeastern Brazil.

Methods: Sera samples (n = 242) were analyzed using an enzyme-linked immunosorbent assay (ELISA). The spatial distribution of dogs seropositive for anti-Leishmania infantum antibodies was evaluated using kernel density estimation.

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Advances in the understanding of leishmaniasis progression indicate that cellular interactions more complex than the Th1/Th2 paradigm define the course of infection. Th17 cells are a crucial modulator of adaptive immunity against parasites acting mainly on neutrophil recruitment and playing a dual role at the site of infection. This review describes the roles of both these cell types in linking innate defense responses to the establishment of specific immunity.

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Introduction:: Molecular techniques have been shown to be alternative methods for the accurate detection of infectious and parasitic diseases, such as the leishmaniases. The present study describes the optimization and evaluation of a duplex real-time quantitative PCR (qPCR) protocol developed for the simultaneous detection of Leishmania infantum DNA and sample quality control.

Methods:: After preliminary tests with the newly designed TaqMan® probes for the two targets ( L.

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Article Synopsis
  • Recent advancements in noninvasive biological sample collection have sparked greater interest in using molecular biology for diagnosing visceral leishmaniasis (VL), with urine samples proving to be safer and more comfortable for both patients and healthcare providers.
  • A study assessed the effectiveness of detecting Leishmania infantum DNA in urine using real-time quantitative PCR (qPCR), achieving a high concordance rate of 96.08% when compared to existing diagnostic methods.
  • The findings suggest that urine is a viable specimen for diagnosing VL, especially since it can detect Leishmania DNA in untreated individuals, and can help monitor treatment efficacy based on the quick reduction of DNA post-therapy.
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Background: Cutaneous leishmaniasis (CL) is a parasitic disease caused by various Leishmania species. Several studies have shown that real time quantitative PCR (qPCR) can be used for Leishmania spp. identification by analyzing the melting temperature (Tm).

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Leishmaniases are caused by obligate intracellular protozoan parasites of the genus Leishmania. They cause a spectrum of diseases, most notably visceral (VL), cutaneous (CL), and mucosal (ML) leishmaniasis, which affect millions of people around the world, each year. Despite scientific advances, leishmaniases cases are expanding, constituting an important public health problem.

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Early detection of leishmaniases and prompt institution of treatment are paramount for individuals and communities affected by these diseases. To overcome the remaining limitations inherent to molecular methods currently used and to ensure the accuracy of results in leishmaniases diagnosis, two triplex polymerase chain reaction (PCR) assays with quality controls for the reactions were developed. Validity indicators were assessed in 186 dog blood samples from endemic areas in Brazil.

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Background: Molecular biological methods have become increasingly relevant to the diagnosis and control of infectious diseases, such as leishmaniasis. Since various factors may affect the sensitivity of PCR assays, including DNA yield and purity, an optimal extraction method is pivotal. Losses of a parasite's DNA during extraction may significantly impair its detection by PCR and lead to false-negative results.

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Article Synopsis
  • - American cutaneous leishmaniasis (ACL) is primarily caused by the Leishmania braziliensis species, especially in Pernambuco, Brazil, where the disease is common.
  • - In this research, 117 ectoparasites (ticks, fleas, and lice) were tested, revealing that 42.74% were positive for L. braziliensis, with a notable percentage collected from infected dogs.
  • - While the study detected L. braziliensis DNA in these ectoparasites, it does not confirm if they can transmit the parasite, indicating the need for further experiments to explore their potential role as vectors.
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Visceral leishmaniosis (VL) is a parasitic disease caused by Leishmania infantum, which is primarily transmitted by phlebotomine sandflies. However, there has been much speculation on the role of other arthropods in the transmission of VL. Thus, the aim of this study was to assess the presence of L.

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