Metallic nanoparticles and treatment of cutaneous leishmaniasis: A systematic review.

BACKGROUND: Cutaneous leishmaniasis (LC) is an infectious vector-borne disease caused by parasites belonging to the genus Leishmania. Metallic nanoparticles (MNPs) have been investigated as alternatives for the treatment of LC owing to their small size and high surface area. Here, we aimed to evaluate the effect of MNPs in the treatment of LC through experimental, in vitro and in vivo investigations. METHODS: The databases used were MEDLINE/ PubMed, Scopus, Web of Science, Embase, and Science Direct. Manual searches of the reference lists of the included studies and grey literature were also performed. English language and experimental in vitro and in vivo studies using different Leishmania species, both related to MNP treatment, were included. This study was registered in PROSPERO (CRD42021248245). RESULTS: A total of 93 articles were included. Silver nanoparticles are the most studied MNPs, and L. tropica is the most studied species. Among the mechanisms of action of MNPs in vitro, we highlight the production of reactive oxygen species, direct contact of MNPs with the biomolecules of the parasite, and release of metal ions. CONCLUSION: MNPs may be considered a promising alternative for the treatment of LC, but further studies are needed to define their efficacy and safety.

Inflammatory Response and Activation of Coagulation after COVID-19 Infection.

SARS-CoV-2 (COVID-19) infection is responsible for causing a disease with a wide spectrum of clinical presentations. Predisposition to thromboembolic disease due to excessive inflammation is also attributed to the disease. The objective of this study was to characterize the clinical and laboratory aspects of hospitalized patients, in addition to studying the pattern of serum cytokines, and associate them with the occurrence of thromboembolic events. METHODOLOGY: A retrospective cohort study with 97 COVID-19 patients hospitalized from April to August 2020 in the Triângulo Mineiro macro-region was carried out. A review of medical records was conducted to evaluate the clinical and laboratory aspects and the frequency of thrombosis, as well as the measurement of cytokines, in the groups that presented or did not present a thrombotic event. RESULTS: There were seven confirmed cases of thrombotic occurrence in the cohort. A reduction in the time of prothrombin activity was observed in the group with thrombosis. Further, 27.8% of all patients had thrombocytopenia. In the group that had thrombotic events, the levels of IL1b, IL-10, and IL2 were higher (p < 0.05). CONCLUSIONS: In the studied sample, there was an increase in the inflammatory response in patients with thrombotic events, confirmed by the increase in cytokines. Furthermore, in this cohort, a link was observed between the IL-10 percentage and an increased chance of a thrombotic event.

Clinical-Epidemiology Aspect of Inpatients With Moderate or Severe COVID-19 in a Brazilian Macroregion: Disease and Countermeasures.

COVID-19, also known as coronavirus disease 2019, is an infectious viral disease caused by SARS-CoV-2, a novel coronavirus. Since its emergence, its epidemiology has been explored; however, for some regions of the world, COVID-19's behavior, incidence, and impact remain unclear. In continental nations like Brazil, this lack of knowledge results in nonuniform control, prevention, and treatment measures, which can be controversial in some locations. This study aimed to describe the epidemiological profile of patients with COVID-19 in the macroregion of Triângulo Sul in the state of Minas Gerais (MG), Brazil. Between March 25 and October 21, 2020, data were collected and statistically analyzed from 395 hospitalized patients in the city of Uberaba, MG, suspected to have moderate or severe forms of the disease. Of the 395 suspected cases, 82% were confirmed to be positive for COVID-19. The mean age of positive patients was 58.4 years, and 60.76% were male. Following these patients throughout their hospitalization, a mortality rate of 31.3% was observed. In the population positive for COVID-19, the risk of death increased by 4% for each year of the patient's age. Likewise, the older the patient, the longer their hospitalization and the higher the risk of developing acute respiratory failure. Among the treatments tested in patients, heparin was associated with protection against mortality, and the absence of anticoagulant use was linked to a more than six times greater risk of death. Finally, comorbidities in patients with COVID-19 were positively correlated with increased hospitalization time. In summary, this study revealed that age, presence of comorbidities, length of hospitalization, and drug treatment considerably altered COVID-19's lethality. To understand infection rates and the factors involved in COVID-19's lethality, knowledge of the local epidemiology is necessary.

T Lymphocyte Exhaustion During Human and Experimental Visceral Leishmaniasis.

A key point of immunity against protozoan Leishmania parasites is the development of an optimal T cell response, which includes a low apoptotic rate, high proliferative activity and polyfunctionality. During acute infection, antigen-specific T cells recognize the pathogen resulting in pathogen control but not elimination, promoting the development and the maintenance of a population of circulating effector cells that mount rapid response quickly after re-exposure to the parasite. However, in the case of visceral disease, the functionality of specific T cells is lost during chronic infection, resulting in inferior effector functions, poor response to specific restimulation, and suboptimal homeostatic proliferation, a term referred to as T cell exhaustion. Multiple factors, including parasite load, infection duration and host immunity, affect T lymphocyte exhaustion. These factors contribute to antigen persistence by promoting inhibitory receptor expression and sustained production of soluble mediators, influencing suppressive cell function and the release of endogenous molecules into chronically inflamed tissue. Together, these signals encourage several changes, reprogramming cells into a quiescent state, which reflects disease progression to more severe forms, and development of acquired resistance to conventional drugs to treat the disease. These points are discussed in this review.

Public perception of COVID-19 in the Triângulo Mineiro region, Minas Gerais state, Brazil: a cross-sectional survey

This was a cross-sectional, anonymous, online survey aimed at assessing the perceptions and basic knowledge of COVID-19, a highly transmissible disease caused by SARS-CoV-2, in a sample population in the Triângulo Mineiro region, Minas Gerais, Brazil. A questionnaire devised by the researchers and distributed through social media was applied between June 16, 2020 and August 21, 2020. The survey consisted of questions about the basic aspects of COVID-19, which included symptoms, risk groups, suspicion of infection, prevention, transmission, and perception regarding social isolation. The average distribution, frequencies, similarities and differences between the responses for the different variables were evaluated. Five hundred twenty valid responses were obtained from participants aged ≥18 years. Most of the respondents showed satisfactory basic knowledge of COVID-19. Moreover, the data showed that the participants scored an average of 87.6%. Sex, age, and socioeconomic vulnerability presented a statistically significant link with knowledge of the disease; women, young participants, and the least socioeconomically vulnerable had the highest scores. This study indicated that the population in the Triângulo Mineiro region able to access social networking platforms were basically well informed regarding COVID-19, although differences were observed depending on the group analyzed.

In Silico Identification of New Targets for Diagnosis, Vaccine, and Drug Candidates against Trypanosoma cruzi.

Chagas disease is a neglected tropical disease caused by the parasite Trypanosoma cruzi. Despite the efforts and distinct methodologies, the search of antigens for diagnosis, vaccine, and drug targets for the disease is still needed. The present study is aimed at identifying possible antigens that could be used for diagnosis, vaccine, and drugs targets against T. cruzi using reverse vaccinology and molecular docking. The genomes of 28 T. cruzi strains available in GenBank (NCBI) were used to obtain the genomic core. Then, subtractive genomics was carried out to identify nonhomologous genes to the host in the core. A total of 2630 conserved proteins in 28 strains of T. cruzi were predicted using OrthoFinder and Diamond software, in which 515 showed no homology to the human host. These proteins were evaluated for their subcellular localization, from which 214 are cytoplasmic and 117 are secreted or present in the plasma membrane. To identify the antigens for diagnosis and vaccine targets, we used the VaxiJen software, and 14 nonhomologous proteins were selected showing high binding efficiency with MHC I and MHC II with potential for in vitro and in vivo tests. When these 14 nonhomologous molecules were compared against other trypanosomatids, it was found that the retrotransposon hot spot (RHS) protein is specific only for T. cruzi parasite suggesting that it could be used for Chagas diagnosis. Such 14 proteins were analyzed using the IEDB software to predict their epitopes in both B and T lymphocytes. Furthermore, molecular docking analysis was performed using the software MHOLline. As a result, we identified 6 possible T. cruzi drug targets that could interact with 4 compounds already known as antiparasitic activities. These 14 protein targets, along with 6 potential drug candidates, can be further validated in future studies, in vivo, regarding Chagas disease.