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In this household-based seroepidemiological survey, we analyzed the dynamics of SARS-CoV-2 seroprevalence during the first year of the COVID-19 pandemic in Sergipe State, Northeast Brazil, the poorest region of the country. A total of 16,547 individuals were tested using a rapid IgM−IgG antibody test and fluorescence immunoassay (FIA). Seroprevalence rates were presented according to age, sex, and geographic region. A comparative analysis was performed between the results obtained in July 2020 (peak of the first wave), August – November 2020 (end of the first wave), and February – March 2021 (beginning of the second wave). Seroprevalence rates in the three phases were estimated at 9.3% (95% CI 8.5–10.1), 12.0% (95% CI 11.2–12.9) and 15.4% (95% CI 14.5–16.4). At the end of the first wave, there was a rise in seroprevalence in the countryside (p < 0.001). At the beginning of the second wave, we found an increase in seroprevalence among women (p < 0.001), adults aged 20 to 59 years (p < 0.001), and the elderly (p < 0.001). In this phase, we found an increase in estimates both in metropolitan areas and in the countryside (p < 0.001). This study showed an increase in SARS-CoV-2 seroprevalence over the first year of the pandemic, with approximately one in six people having anti-SARS-CoV-2 antibodies at the beginning of the second wave of COVID-19. Furthermore, our results suggest a rapid spread of COVID-19 from metropolitan areas to the countryside during the first months of the pandemic. [ABSTRACT FROM AUTHOR]

Visceral leishmaniasis (VL) is a chronic and often fatal disease caused by protozoans of the genus Leishmania that affects millions of people worldwide. Patients with symptomatic VL have an impaired anti- Leishmania -specific CD4+ T-cell response, which is reversed after clinical cure. In contrast, the quality of the CD4+ and CD8+ T-cell responses involved in resistance and/or cure of VL relies on the capability of these cells to activate polyfunctional and memory responses, which are associated with the simultaneous production of three cytokines: IFN-γ, IL-2, and TNF-α. Models for the development of CD4 and CD8 T-cell quality in memory and protection to leishmaniasis have been described previously. We aimed to assess the functionality of the T cells involved in the recovery of the immune suppression throughout the VL treatment. Therefore, we cultured peripheral blood mononuclear cells (PBMCs) from VL patients and healthy controls in vitro with soluble Leishmania antigen (SLA). Cell surface markers and intracellular cytokine production were determined on days 7, 14, 21, 30, 60, 90, and 180 after the beginning of chemotherapy. We observed that the frequencies of CD4+TNF-α+IFN-γ+ and the multifunctional CD4+IL-2+TNF-α+IFN-γ+, together with CD4+TNF-α+ and CD4+IFN-γ+ T cells, increased throughout and at the end of the treatment, respectively. In addition, enhanced frequencies of CD8+IL-2+TNF-α+IFN-γ+ and CD8+TNF-α+IFN-γ T cells were also relevant in the healing process. Noteworthy, the frequencies of the CD4+ and CD8 central-memory T cells, which produce IL-2, TNF-α, and IFN-γ and ensure the memory response against parasite reinfection, are significantly enhanced in cured patients. In addition, the subset of the non-functional CD8Low population is predominant in VL untreated patients and decreases along the chemotherapy treatment. In contrast, a CD8High subset increased towards the cure. Furthermore, the cure due to treatment with meglumine antimoniate or with liposomal amphotericin B was associated with the recovery of the T-cell immune responses. We described the evolution and participation of functional T cells during the treatment of patients with VL. Our results disclosed that the clinical improvement of patients is significantly associated with the participation of the CD4+ and CD8+ cytokine-secreting T cells. [ABSTRACT FROM AUTHOR]

EXCLI Journal 2021;20:276-280 - ISSN 1611-2156 Received: January 27, 2021, accepted: February 06, 2021, published: February 09, 2021 276 Letter to the editor: SEROPREVALENCE OF SARS-COV-2 ANTIBODIES IN LOW-INCOME UNIVERSITY STUDENTS Adriano Antunes de Souza Araújo, PhD 1,5,6, Lucindo José Quintans-Júnior, PhD 2,5,6*, Dulce Marta Schimieguel, PhD 1,6, Cristiane Bani Corrêa, PhD 3,5, Tatiana Rodrigues de Moura, PhD 3,5, Rafael Ciro Marques Cavalcante, PhD 4, Renata Grespan, PhD 2,7, Daniele de Vasconcelos Cerqueira-Meneses, MSc 5, José Antônio Barreto-Alves, PhD 8, Paulo Ricardo Martins-Filho, PhD 5,9 1 Department of Pharmacy, Federal University of Sergipe, São Cristóvão, Sergipe, Brazil 2 Department of Physiology, Federal University of Sergipe, São Cristóvão, Sergipe, Brazil 3 Department of Morphology, Federal University of Sergipe, São Cristóvão, Sergipe, Brazil 4 Department of Pharmacy, Federal University of Sergipe, Lagarto, Sergipe, Brazil 5 Health Sciences Graduate Program, Federal University of Sergipe, Aracaju, Sergipe, Brazil 6 Graduate Program in Pharmaceutical Sciences, Federal University of Sergipe, São Cristóvão, Sergipe, Brazil 7 Graduate Program in Physiological Sciences, Federal University of Sergipe, São Cristóvão, Sergipe, Brazil 8 Graduate Program in Nursing, Federal University of Sergipe, Aracaju, Sergipe, Brazil 9 Investigative Pathology Laboratory, Federal University of Sergipe, Aracaju, Sergipe, Brazil * Corresponding author: Prof. L.J. Quintans-Júnior, Universidade Federal de Sergipe, Departamento de Fisiologia. EXCLI Journal 2021;20:276-280 - ISSN 1611-2156 Received: January 27, 2021, accepted: February 06, 2021, published: February 09, 2021 277 This cross-sectional study included students registered with the Programa de Auxílio Moradia e Residência Universitária (PAMRU- the Housing and University Residency Assistance Program) at the Federal University of Sergipe (UFS), Sergipe State, Northeast Brazil. [Extracted from the article]

Polymer hydrogels have been suggested as dressing materials for the treatment of cutaneous wounds and tissue revitalization. In this work, we report the development of a hydrogel composed of natural polymers (sodium alginate and gelatin) and silver nanoparticles (AgNPs) with recognized antimicrobial activity for healing cutaneous lesions. For the development of the hydrogel, different ratios of sodium alginate and gelatin have been tested, while different concentrations of AgNO3 precursor (1.0, 2.0, and 4.0 mM) were assayed for the production of AgNPs. The obtained AgNPs exhibited a characteristic peak between 430–450 nm in the ultraviolet-visible (UV–Vis) spectrum suggesting a spheroidal form, which was confirmed by Transmission Electron Microscopy (TEM). Fourier Transform Infra-red (FT–IR) analysis suggested the formation of strong intermolecular interactions as hydrogen bonds and electrostatic attractions between polymers, showing bands at 2920, 2852, 1500, and 1640 cm−1. Significant bactericidal activity was observed for the hydrogel, with a Minimum Inhibitory Concentration (MIC) of 0.50 µg/mL against Pseudomonas aeruginosa and 53.0 µg/mL against Staphylococcus aureus. AgNPs were shown to be non-cytotoxic against fibroblast cells. The in vivo studies in female Wister rats confirmed the capacity of the AgNP-loaded hydrogels to reduce the wound size compared to uncoated injuries promoting histological changes in the healing tissue over the time course of wound healing, as in earlier development and maturation of granulation tissue. The developed hydrogel with AgNPs has healing potential for clinical applications. [ABSTRACT FROM AUTHOR]

Introduction: In VL, a proinflammatory phenotype is typically associated with enhanced phagocytosis and a Th1 mediated immune response resulting in infection control. In contrast, an anti-inflammatory phenotype, associated with a predominant regulatory response, typically enables intracellular multiplication of Leishmania parasites and disease progression., Methods: To investigate the impact of chemotherapy on Th2 and Th17 immune responses in patients with visceral leishmaniasis (VL), we assessed all combinations of intracellular expression of IFN-γ, IL-10, IL-4 and IL-17 in the CD4 + and CD8 + T cell populations of peripheral blood mononuclear cell (PBMC) samples from patients, after antigenic stimulation with Leishmania lysate, throughout treatment and follow-up. As increases in spleen and liver sizes and decreases in hematocrit, hemogloblin, erythrocytes, monocytes, leukocytes and platelets levels are strongly related to the disease, we studied the correlations between the frequencies of T cells producing the afore mentioned cytokines, individually and in combination, and these variables, as markers of disease or cure., Results: We found that the frequency of IFN-γ-producingCD4 + T cells increased until the end of chemotherapy with Glucantime® or AmBisome ®, while IL-10, IL-4 and IL-17-producing CD4 + T cells peaked on day 7 following the start of treatment. Although the frequency of CD4 + IL-17 + cells decreased during treatment an increase was observed after clinical cure. The frequency of CD4 + T cells producing only IFN-γ or IL-17 correlated with blood monocytes levels. Frequencies of double-producers of IFN-γ and IL-10 or IL-4 correlated positively with eosinophils and platelets levels. Together, this suggest that IFN-γ drives the immune response towards Th1 at cure. In contrast, and associated with disease or Th2 response, the frequency of CD4 + IL-10 + cells correlated positively with spleen sizes and negatively with circulating monocyte levels, while the frequency of CD4 + producing both IL-4 and IL-10 correlated negatively with platelets levels. The frequency of CD8 + single-producers of IFN-γ increased from day 21 to 90 while that of single-producers of IL-10 peaked on day 7, of IL-4 on day 30 and of IL-17, on day 180. IFN-γ expression in CD8 + single- and double-producers of cytokines was indicative of an immune response associated with cure. In contrast, frequencies of CD8 + double-producers of IL-4 and IL-10, IL-4 and IL-17 and IL-10 and IL-17 and producers of three and four cytokines, were associated with disease and were low after the cure. Frequencies of CD8 + T cells producing IFN-γ alone or with IL-17 were positively correlated with platelets levels. In contrast, as markers of disease: 1) frequencies of single producers of IL-10 correlated negatively with leukocytes levels, 2) frequencies of double producers of IL-4 and IL-10 correlated negatively with platelet, leukocyte, lymphocyte and circulating monocyte levels, 3) frequencies of triple-producers of IFN-γ, IL-4 and IL-10 correlated negatively with platelet, leukocyte and neutrophil levels and 4) frequencies of producers of IFN-γ, IL-4, IL-10 and IL-17 simultaneously correlated positively with spleen size, and negatively with leukocyte and neutrophil levels., Discussion: Our results confirmed that the clinical improvement of VL patients correlates with the decrease of an IL-4 and IL-10 CD4 + Th2 response, the recovery of CD4+ Th1 and Th17 responses and the frequency of CD8 + single-producers of IFN-γ and double producers of IFN-γ and IL-17., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest. The author(s) declared that they were an editorial board member of Frontiers, at the time of submission. This had no impact on the peer review process and the final decision., (Copyright © 2024 de Franca, Rodrigues, Barreto, da Cruz, Aragão-Santos, da Silva, de Jesus, Palatnik-de-Sousa, de Almeida and Corrêa.)

Background: SARS-CoV-2 infection can lead to the abnormal induction of cytokines and a dysregulated hyperinflammatory state that is implicated in disease severity and risk of death. There are several molecules present in blood associated with immune cellular response, inflammation, and oxidative stress that could be used as severity markers in respiratory viral infections such as COVID-19. However, there is a lack of clinical studies evaluating the role of oxidative stress-related molecules including glial fibrillary acidic protein (GFAP), the receptor for advanced glycation end products (RAGE), high mobility group box-1 protein (HMGB1) and cyclo-oxygenase-2 (COX-2) in COVID-19 pathogenesis., Aim: To evaluate the role of oxidative stress-related molecules in COVID-19., Method: An observational study with 93 Brazilian participants from September 2020 to April 2021, comprising 23 patients with COVID-19 admitted to intensive care unit (ICU), 19 outpatients with COVID-19 with mild to moderate symptoms, 17 individuals reporting a COVID-19 history, and 34 healthy controls. Blood samples were taken from all participants and western blot assay was used to determine the RAGE, HMGB1, GFAP, and COX-2 immunocontent., Results: We found that GFAP levels were higher in patients with severe or critical COVID-19 compared to outpatients (p = 0.030) and controls (p < 0.001). A significant increase in immunocontents of RAGE (p < 0.001) and HMGB1 (p < 0.001) were also found among patients admitted to the ICU compared to healthy controls, as well as an overexpression of the inducible COX-2 (p < 0.001). In addition, we found a moderate to strong correlation between RAGE, GFAP and HMGB1 proteins., Conclusion: SARS-CoV-2 infection induces the upregulation of GFAP, RAGE, HMGB1, and COX-2 in patients with the most severe forms of COVID-19., (Copyright © 2021. Published by Elsevier B.V.)

Visceral leishmaniasis (VL) is a chronic and often fatal disease caused by protozoans of the genus Leishmania that affects millions of people worldwide. Patients with symptomatic VL have an impaired anti- Leishmania -specific CD4 + T-cell response, which is reversed after clinical cure. In contrast, the quality of the CD4 + and CD8 + T-cell responses involved in resistance and/or cure of VL relies on the capability of these cells to activate polyfunctional and memory responses, which are associated with the simultaneous production of three cytokines: IFN-γ, IL-2, and TNF-α. Models for the development of CD4 and CD8 T-cell quality in memory and protection to leishmaniasis have been described previously. We aimed to assess the functionality of the T cells involved in the recovery of the immune suppression throughout the VL treatment. Therefore, we cultured peripheral blood mononuclear cells (PBMCs) from VL patients and healthy controls in vitro with soluble Leishmania antigen (SLA). Cell surface markers and intracellular cytokine production were determined on days 7, 14, 21, 30, 60, 90, and 180 after the beginning of chemotherapy. We observed that the frequencies of CD4 + TNF-α + IFN-γ + and the multifunctional CD4 + IL-2 + TNF-α + IFN-γ + , together with CD4 + TNF-α + and CD4 + IFN-γ + T cells, increased throughout and at the end of the treatment, respectively. In addition, enhanced frequencies of CD8 + IL-2 + TNF-α + IFN-γ + and CD8 + TNF-α + IFN-γ T cells were also relevant in the healing process. Noteworthy, the frequencies of the CD4 + and CD8 central-memory T cells, which produce IL-2, TNF-α, and IFN-γ and ensure the memory response against parasite reinfection, are significantly enhanced in cured patients. In addition, the subset of the non-functional CD8 Low population is predominant in VL untreated patients and decreases along the chemotherapy treatment. In contrast, a CD8 High subset increased towards the cure. Furthermore, the cure due to treatment with meglumine antimoniate or with liposomal amphotericin B was associated with the recovery of the T-cell immune responses. We described the evolution and participation of functional T cells during the treatment of patients with VL. Our results disclosed that the clinical improvement of patients is significantly associated with the participation of the CD4 + and CD8 + cytokine-secreting T cells., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2021 Rodrigues, Barreto, Bomfim, Gomes, Ferreira, da Cruz, Magalhães, de Jesus, Palatnik-de-Sousa, Corrêa and de Almeida.)