Macrophage Migration Inhibitory Factor contributes to drive phenotypic and functional macrophages activation in response to Toxoplasma gondii infection.

Cytokines are small molecules secreted by numerous cells. Macrophage Migration Inhibitory Factor (MIF) is a cytokine initially described due to its function of inhibiting random macrophage migration. Currently, new functions have been described for MIF, such as stimulating inflammatory functions in response to infections by microorganisms including, Toxoplasma gondii. However, the primordial MIF function related to macrophages has been little addressed. The main purpose of the study was to recapitulate MIF function on macrophages in response to T. gondii infection. To achieve this goal, peritoneal macrophages were collected from C57BL/6WT and Mif1-/- mice after recruitment with thioglycolate. Macrophages were cultured, treated with 4-Iodo-6-phenylpyrimidine (4-IPP), and infected or not by T. gondii for 24 h. Following this, the culture supernatant was collected for cytokine, urea and nitrite analysis. In addition, macrophages were evaluated for phagocytic activity and T. gondii proliferation rates. Results demonstrated that T. gondii infection triggered an increase in MIF production in the WT group as well as an increase in the secretion of IL-10, TNF, IFN-γ, IL-6 and IL-17 in the WT and Mif1-/- macrophages. Regarding the comparison between groups, it was detected that Mif1-/- macrophages secreted more IL-10 compared to WT. On the other hand, the WT macrophages produced greater amounts of TNF, IFN-γ, IL-6 and IL-17. Urea production was more pronounced in Mif1-/- macrophages while nitrite production was higher in WT macrophages. T. gondii showed a greater ability to proliferate in Mif1-/- macrophages and these cells also presented enhanced phagocytic activity. In conclusion, T. gondii infection induces macrophage activation inciting cytokine production. In presence of MIF, T. gondii infected macrophages produce pro-inflammatory cytokines compatible with the M1 activation profile. MIF absence caused a dramatic reduction in pro-inflammatory cytokines that are balanced by increased levels of urea and anti-inflammatory cytokines. These macrophages presented increased phagocytic capacity and shared features activation with the M2 profile.

Exploring the functionalization of Ti-6Al-4V alloy with the novel antimicrobial peptide JIChis-2 via plasma polymerization.

This study aimed to characterize the immobilization of the novel JIChis-2 peptide on the Ti-6Al-4V alloy, widely used in the biomedical sector. The antimicrobial activity of JIChis-2 was evaluated in the Gram-negative bacterium E. coli. Its immobilization occurred by inducing the formation of covalent bonds between the N-terminus of the peptides and the surface previously submitted to acrylic acid polymerization via the PECVD technique. Coated and uncoated surfaces were characterized by FTIR, AFM, SEM and EDX. Studies of global and localized corrosion were carried out, seeking to explore the effects triggered by surface treatment in an aggressive environment. Additionally, the ability of the functionalized material to prevent E. coli biofilm formation evidenced that the strategy to immobilize JIChis-2 in the Ti-6Al-4V alloy via PECVD of acrylic acid resulted in the development of a functional material with antibiofilm properties.

Development of Ag-ZnO/AgO Nanocomposites Effectives for Leishmania braziliensis Treatment.

Tegumentary leishmaniasis (TL) is caused by parasites of the genus Leishmania. Leishmania braziliensis (L.b) is one of the most clinically relevant pathogens that affects the skin and mucosa, causing single or multiple disfiguring and life-threatening injuries. Even so, the few treatment options for patients have significant toxicity, high dropout rates, high cost, and the emergence of resistant strains, which implies the need for studies to promote new and better treatments to combat the disease. Zinc oxide nanocrystals are microbicidal and immunomodulatory agents. Here, we develop new Ag-ZnO/xAgO nanocomposites (NCPs) with three different percentages of silver oxide (AgO) nanocrystals (x = 49%, 65%, and 68%) that could act as an option for tegumentary leishmaniasis treatment. Our findings showed that 65% and 68% of AgO inhibit the extra and intracellular replication of L.b. and present a high selectivity index. Ag-ZnO/65%AgO NCPs modulate activation, expression of surface receptors, and cytokine production by human peripheral blood mononuclear cells toward a proinflammatory phenotype. These results point to new Ag-ZnO/AgO nanocomposites as a promising option for L. braziliensis treatment.

Proximity matrix indicates heterogeneity in the ability to face child malnutrition and pandemics in Brazil: An ecological study.

Background: Among the social inequalities that continue to still surpasses the basic rights of several citizens, political and environmental organizations decisively "drag" the "ghost" of hunger between different countries of the world, including Brazil. The COVID-19 pandemic has increased the difficulties encountered in fighting poverty, which has led Brazil to a worrying situation regarding its fragility in the fight against new pandemics. Objectives: The present study aims to estimate, compare, and report the prevalence of mortality due to child malnutrition among the macro-regions of Brazil and verify possible associations with the outcome of death by COVID-19. This would identify the most fragile macro-regions in the country with the greatest need for care and investments. Methods: The prevalence of mortality was determined using data from the federal government database (DataSus). Child malnutrition was evaluated for the period from 1996 to 2017 and COVID-19 was evaluated from February to December 2020. The (dis)similarity between deaths from malnutrition and COVID-19 was evaluated by proximity matrix. Results: The North and Northeast regions have above average number of deaths than expected for Brazil (p < 0.05). A prospective analysis reveals that the distribution of the North and Northeast macro-regions exceeds the upper limit of the CI in Brazil for up to the year 2024 (p < 0.05). The proximity matrix demonstrated the close relationship between deaths from COVID-19 and malnutrition for the Northern region followed by the Northeast region. Conclusions: There are discrepancies in frequencies between macro-regions. Prospective data indicate serious problems for the North and Northeast regions for the coming years. Therefore, strategies to contain the outcome of health hazards must be intensified in the macro-regions North and Northeast of the country.

Insights into the Vibrio Genus: A One Health Perspective from Host Adaptability and Antibiotic Resistance to In Silico Identification of Drug Targets.

The genus Vibrio comprises an important group of ubiquitous bacteria of marine systems with a high infectious capacity for humans and fish, which can lead to death or cause economic losses in aquaculture. However, little is known about the evolutionary process that led to the adaptation and colonization of humans and also about the consequences of the uncontrollable use of antibiotics in aquaculture. Here, comparative genomics analysis and functional gene annotation showed that the species more related to humans presented a significantly higher amount of proteins associated with colonization processes, such as transcriptional factors, signal transduction mechanisms, and iron uptake. In comparison, those aquaculture-associated species possess a much higher amount of resistance-associated genes, as with those of the tetracycline class. Finally, through subtractive genomics, we propose seven new drug targets such as: UMP Kinase, required to catalyze the phosphorylation of UMP into UDP, essential for the survival of bacteria of this genus; and, new natural molecules, which have demonstrated high affinity for the active sites of these targets. These data also suggest that the species most adaptable to fish and humans have a distinct natural evolution and probably undergo changes due to anthropogenic action in aquaculture or indiscriminate/irregular use of antibiotics.

Immunophenotypic Analysis of T Lymphocytes and Cytokine Production in Elderly Practicing Physical Activities and Its Relationship with Quality of Life and Depression.

Aging is a complex process often associated with a chronic inflammatory profile that alters several biological functions, including the immune system and cognitive and physical capacity. The practice of physical activity is increasingly gaining popularity as a method of preventing infections, depression, and other disorders that affect the quality of life of the elderly. Thus, this work analyzes the profile of cytokines and molecular markers expressed in immune cells of elderly people who practice physical activities or not, evaluating their impacts on the immune system and quality of life. For this, 48 individuals were recruited, and peripheral blood samples were collected for hemogram analysis, cytokine determination, and immunophenotyping. Elderly people were separated into two groups: practitioners with low-intensity physical activity and non-practitioners. Quality of life was assessed using the Whoqol-Old instrument, and depression was assessed using the Beck II Depression Inventory. When comparing the scores of the Whoqol-Old and Beck questionnaires, we observed a significant negative correlation between these two factors. The perception of a higher quality of life was present in the elderly who exercised and was related to greater autonomy and sensory abilities, whereas the presence of depression was lower. In the hemogram, we observed higher basophil and segmented counts in the sedentary elderly, whereas lymphocytes and monocytes had lower counts. Elderly practitioners of physical activities had higher levels of IFN-γ, IL-4, and IL-10; increased expression of CD69, PD1, and TIM-3 in CD4+ T lymphocytes and increased CD14+CD80+ and CD14+CD86+ monocytes. Elderly people with an increased perception of quality of life had higher levels of IFN-γ, higher expression of CD14+CD80+CD86+, and decreased levels of TRAIL. An increase in TRAIL was observed in individuals with depression, in addition to an increased expression of CD14+CD86+. These results show a clear correlation between the quality of life, level of depression, physical activity, and immune system function. Although some cytokines with a typical proinflammatory profile (IFN-γ) were observed, the results point to a protective state with benefits reflected in the general well-being of the elderly who exercise.

Role of Cytokines, Chemokines and IFN-γ+ IL-17+ Double-Positive CD4+ T Cells in Patients with Multiple Sclerosis.

Multiple sclerosis is mediated by self-reactive myelin T and B cells that lead to axonal and myelin damage. The immune response in multiple sclerosis involves the participation of CD4+ T cells that produce cytokines and chemokines. This participation is important to find markers for the diagnosis and progression of the disease. In our work, we evaluated the profile of cytokines and chemokines, as well as the production of double positive CD4+ T cells for the production of IFNγ IL-17 in patients with multiple sclerosis, at different stages of the disease and undergoing different treatments. We found that relapsing-remitting patients had a significant increase in IL-12 production. About IL-5, its production showed significantly higher levels in secondarily progressive patients when compared to relapsing-remitting patients. IFN-γ production by PBMCs from secondarily progressive patients showed significantly higher levels. This group also had a higher percentage of CD4+ IFNγ+ IL-17+ T cells. The combination of changes in certain cytokines and chemokines together with the presence of IFNγ+ IL-17+ double positive lymphocytes can be used to better understand the clinical forms of the disease and its progression.

Staphylococcus aureus and Enterococcus faecium isolated from pigeon droppings (Columba livia) in the external environment close to hospitals

ABSTRACT Background: Domestic pigeons carry pathogens in their droppings, posing a potential public health problem. Methods: The phenotypic and genotypic antimicrobial resistances of Staphylococcus aureus and Enterococcus faecium in the feces of urban pigeons near hospitals with intensive care units were measured. Results: Twenty-nine samples showed Enterococcus growth, whereas one was positive for S. aureus. The S. aureus isolate was sensitive to the antibiotics tested via antibiogram, however resistance genes were identified. E. faecium isolates showed phenotypic resistance to gentamicin, erythromycin, and ciprofloxacin. Conclusions: Antimicrobial profiles harmful to health were demonstrated in bacterial pathogens isolated from the external environment of hospitals.

In silico designing of a recombinant multi-epitope antigen for leprosy diagnosis.

BACKGROUND: Leprosy is caused by Mycobacterium leprae and Mycobacterium lepromatosis. Most of the affected population lives in low-income countries and may take up to 10 years to show any clinical signs, which is how physicians diagnose it. However, due to progressive cell damage, early diagnosis is very important. The best way to confirm leprosy is through bacilloscopic, which only confirms the diagnosis and has low accuracy or PCR, that requires specialized operators and is expensive. Since the bacteria are fastidious and do not grow in any culture media, therefore, diagnosing leprosy in the lab is still a challenge. In this concern, a recombinant multi-epitope protein can be a beneficial strategy in the management of the diagnosis, as diverse immunogenic epitopes are precisely selected to detect specific antibodies. Therefore, the purposes of the present study were to select immunogenic epitopes from different relevant proteins, with immunogenic properties, and then to construct a recombinant multi-epitope protein that accuses the presence of the antibodies in the early stages of the disease, making it more than appropriate to be applied as a diagnostic tool. RESULTS: We selected 22 common proteins from both species and, using bioinformatics tools, predicted B and T cell epitopes. After multiple filtering and analyzing, we ended up with 29 epitopes {MHC-I (total 18) and MHC-II (total 11)} from 10 proteins, which were then merged into one construct. Its secondary and tertiary structures were also predicted and refined to comprise the amino acid residues in the best conformation possible. The multi-epitope protein construct was stable, non-host homologous, non-allergic, non-toxic, and elicit humoral and cellular responses. It has conformational B cell epitopes and potential to elicit IFN-γ, IL-4, and IL-10 secretion. CONCLUSIONS: This novel recombinant multi-epitope protein constructed using the common epitopes from M. leprae and M. lepromatosis has a huge immunological potential, is stable, and can be lyophilized to be used in ELISA plates or even in biosensors, which are user-friendly diagnosis tools, facilitating translation into human sample tests.

Staphylococcus aureus and Enterococcus faecium isolated from pigeon droppings (Columba livia) in the external environment close to hospitals.

BACKGROUND: Domestic pigeons carry pathogens in their droppings, posing a potential public health problem. METHODS: The phenotypic and genotypic antimicrobial resistances of Staphylococcus aureus and Enterococcus faecium in the feces of urban pigeons near hospitals with intensive care units were measured. RESULTS: Twenty-nine samples showed Enterococcus growth, whereas one was positive for S. aureus. The S. aureus isolate was sensitive to the antibiotics tested via antibiogram, however resistance genes were identified. E. faecium isolates showed phenotypic resistance to gentamicin, erythromycin, and ciprofloxacin. CONCLUSIONS: Antimicrobial profiles harmful to health were demonstrated in bacterial pathogens isolated from the external environment of hospitals.

Hemolymph of triatomines presents fungistatic activity against Cryptococcus neoformans and improves macrophage function through MCP-I/TNF-α increase

Triatomines are blood-feeding arthropods belonging to the subfamily Triatominae (Hemiptera; Reduviidae), capable of producing immunomodulatory and water-soluble molecules in their hemolymph, such as antimicrobial peptides (AMPs). In this work, we evaluated the antifungal and immunomodulatory activity of the hemolymph of Meccus pallidipennis (MPH) and Rhodnius prolixus (RPH) against Cryptococcus neoformans. Methods: We assessed the activity of the hemolymph of both insects on fungal growth by a minimum inhibitory concentration (MIC) assay. Further, RAW 264.7 macrophages were cultivated with hemolymph and challenged with C. neoformans. Then, their phagocytic and killing activities were assessed. The cytokines MCP-1, IFN-γ, TNF-α, IL-10, IL-12, and IL-6 were measured in culture supernatants 4- and 48-hours post-infection. Results: Both hemolymph samples directly affected the growth rate of the fungus in a dose-dependent manner. Either MPH or RPH was capable of inhibiting fungal growth by at least 70%, using the lowest dilution (1:20). Treatment of RAW 264.7 macrophages with hemolymph of both insects was capable of increasing the production of MCP-I and TNF-α. In addition, when these cells were stimulated with hemolymph in the presence of C. neoformans, a 2- and a 4-fold increase in phagocytic rate was observed with MPH and RPH, respectively, when compared to untreated cells. For the macrophage killing activity, MPH decreased in approximately 30% the number of viable yeasts inside the cells compared to untreated control; however, treatment with RPH could not reduce the total number of viable yeasts. MPH was also capable of increasing MHC-II expression on macrophages. Regarding the cytokine production, MCP-I and TNF-α, were increased in the supernatant of macrophages treated with both hemolymphs, 4 and 48 hours after stimulation. Conclusion: These results suggested that hemolymph of triatomines may represent a source of molecules capable of presenting antifungal and immunomodulatory activity in macrophages during fungal infection.(AU)

Association of recurrent upper respiratory tract infections with low production of oxygen intermediates in children

Abstract Objectives: Upper respiratory tract infections in children generally have significant morbidity and mortality. There is little data available about functional immaturity of the immune system and the child's susceptibility to infections at the beginning of their lives, thus, justifying a more specific immunological analysis. Method: Analysis of hemograms and innate and adaptive immune responses in 95 children between age 1 to 6 years with episodes of recurrent respiratory infections (test group n = 39) and without these episodes (control group n = 56) was carried out. The production of reactive oxygen intermediates by peripheral blood cells stimulated by phorbol myristate acetate was analyzed. Additionally, the number of B lymphocytes, auxiliary T lymphocytes, and cytotoxic cells was determined using flow cytometry. Results: Results from both groups did not show statistically significant differences in red blood cells, total leukocytes count, and the differential neutrophils, eosinophils, basophils, lymphocytes, and monocytes count. The analysis of the number of B lymphocytes, auxiliary T lymphocytes (LTCD4), and cytotoxic cells (LTCD8) also did not show any difference between both groups. However, the production of radical oxygen intermediates was significantly reduced in the test group as compared to the control group (p < 0.05). Conclusions: There was no difference in the analysis of hemograms, leukograms, or the number of lymphocytes, LTCD4, LTCD8, or LTCD19. The reduced production of oxygen intermediates in the affected group suggests that these children's microbicide capacity is compromised, which may be related to their recurrent respiratory infections.

Hemolymph of triatomines presents fungistatic activity against Cryptococcus neoformans and improves macrophage function through MCP-I/TNF-α increase.

Background: Triatomines are blood-feeding arthropods belonging to the subfamily Triatominae (Hemiptera; Reduviidae), capable of producing immunomodulatory and water-soluble molecules in their hemolymph, such as antimicrobial peptides (AMPs). In this work, we evaluated the antifungal and immunomodulatory activity of the hemolymph of Meccus pallidipennis (MPH) and Rhodnius prolixus (RPH) against Cryptococcus neoformans. Methods: We assessed the activity of the hemolymph of both insects on fungal growth by a minimum inhibitory concentration (MIC) assay. Further, RAW 264.7 macrophages were cultivated with hemolymph and challenged with C. neoformans. Then, their phagocytic and killing activities were assessed. The cytokines MCP-1, IFN-γ, TNF-α, IL-10, IL-12, and IL-6 were measured in culture supernatants 4- and 48-hours post-infection. Results: Both hemolymph samples directly affected the growth rate of the fungus in a dose-dependent manner. Either MPH or RPH was capable of inhibiting fungal growth by at least 70%, using the lowest dilution (1:20). Treatment of RAW 264.7 macrophages with hemolymph of both insects was capable of increasing the production of MCP-I and TNF-α. In addition, when these cells were stimulated with hemolymph in the presence of C. neoformans, a 2- and a 4-fold increase in phagocytic rate was observed with MPH and RPH, respectively, when compared to untreated cells. For the macrophage killing activity, MPH decreased in approximately 30% the number of viable yeasts inside the cells compared to untreated control; however, treatment with RPH could not reduce the total number of viable yeasts. MPH was also capable of increasing MHC-II expression on macrophages. Regarding the cytokine production, MCP-I and TNF-α, were increased in the supernatant of macrophages treated with both hemolymphs, 4 and 48 hours after stimulation. Conclusion: These results suggested that hemolymph of triatomines may represent a source of molecules capable of presenting antifungal and immunomodulatory activity in macrophages during fungal infection.

In vitro antifungal activity of Morinda citrifolia (noni) extract against Candida albicans.

INTRODUCTION: Candida albicans is the main agent of the most common fungal infection, Candidiasis. It is an opportunistic and dangerous pathogen, especially in immunosuppressed patients. The biological properties of Morinda citrifolia (noni) make it a potent antifungal. In this study, antifungal effect of M. citrifolia was evaluated to verify its effect on human cells. METHODOLOGY: Extract of M. citrifolia was used against strains of C. albicans (cEC 1291). Glucose consumption in C. albicans biofilm was determined at different concentrations of M. citrifolia, and germ tube formation was evaluated in the presence and absence of M. citrifolia. Fungicidal activity was determined by the kinetics of fungal cell death. THP-1 and HeLa cells were used for cell viability and apoptosis, and cell proliferation assays, respectively. RESULTS: Cells treated with M. citrifolia maintained higher concentration of glucose than the control group (p < 0.05). Germ tube formation was inhibited in cells treated with M. citrifolia (p < 0.05). M. citrifolia exerted a cytotoxic effect on C. albicans cells with 99.99% lethality after 6.82 h (1:1 and 1:2), and reduced the viability of THP-1 cells by 25% and 67% after 12 and 36 h, respectively. Annexin V expression in THP-1 increased in groups that received higher concentrations of M. citrifolia (p < 0.05), reducing the proliferation of THP-1 and HeLa cells (2.8-fold). A greater cytotoxic effect was observed in fungal cells. CONCLUSIONS: These results indicate that M. citrifolia exerts biological activity against C. albicans and reduces the viability and proliferation of human cells.

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.

Predicting Blood Parasite Load and Influence of Expression of iNOS on the Effect Size of Clinical Laboratory Parameters in Acute Trypanosoma cruzi Infection With Different Inoculum Concentrations in C57BL/6 Mice.

In Chagas disease, the initial responses of phagocyte-mediated innate immunity are strongly associated with the control of Trypanosoma cruzi and are mediated by various signaling pathways, including the inducible nitric oxide synthetase (iNOS) pathway. The clinical and laboratory manifestations of Chagas disease depend on the parasite-host relationship, i.e., the responsive capacity of the host immune system and the immunogenicity of the parasite. Here, we evaluated effect sizes in clinical and laboratory parameters mediated by acute infection with different concentrations of T. cruzi inoculum in mice immunosuppressed via iNOS pathway inactivation. Infection was induced in C57BL/6 wild-type and iNOS-/- mice with the "Y" strain of T. cruzi at three inoculum concentrations (3 × 102, 3 × 103, and 3 × 104). Parasitemia and mortality in both mouse strains were monitored. Immunohistochemistry was performed to quantify amastigotes in cardiac tissues and cardiac musculature cells. Biochemical parameters, such as blood urea nitrogen, sodium, albumin, and globulin concentrations, among others, were measured, and cytokine concentrations were also measured. Effect sizes were determined by the eta squared formula. Compared with that in wild-type animals, mice with an absence of iNOS expression demonstrated a greater parasite load, with earlier infection and a delayed parasitemia peak. Inoculum concentration was positively related to death in the immunosuppressed subgroup. Nineteen parameters (hematological, biochemical, cytokine-related, and histopathological) in the immunocompetent subgroup and four in the immunosuppressed subgroup were associated with parasitemia. Parasitemia, biochemical parameters, and hematological parameters were found to be predictors in the knockout group. The impact of effect sizes on the markers evaluated based on T. cruzi inoculum concentration was notably high in the immunocompetent group (Cohen's d = 88.50%; p <.001). These findings contribute to the understanding of physiopathogenic mechanisms underlying T. cruzi infection and also indicate the influence of the concentration of T. cruzi during infection and the immunosuppression through the iNOS pathway in clinical laboratory heterogeneity reported in acute Chagas disease.

Metallic Nanoparticles: A New Frontier in the Fight Against Leishmaniasis.

Leishmaniasis, a cutaneous, mucocutaneous, or visceral parasitic disease caused by the protozoa of the genus Leishmania, is responsible for approximately 20-40 thousand deaths annually, with Brazil, India, and certain countries in Africa being the most affected. In addition to the parasite's ability to evade the host's immune system, the incidence of vectors, genetics of different hosts, and several deaths are attributed to the limited conventional treatments that have high toxicity, low effectiveness, and prolonged therapeutic regimens. Thus, the development of new alternative therapeutic strategies remains warranted. Metallic nanoparticles, such as gold, silver, zinc oxide, and titanium dioxide, have shown promising therapeutic tools since they are easily prepared and chemically modified, have a broad spectrum of action and low toxicity, and can generate reactive oxygen species and other immune responses. This review explores the progress of the use of metallic nanoparticles as new tools in the treatment of leishmaniasis and discusses the gaps in knowledge hindering the development of a safe and effective therapeutic intervention against these infections.

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.

Salivary and Intestinal Transcriptomes Reveal Differential Gene Expression in Starving, Fed and Trypanosoma cruzi-Infected Rhodnius neglectus.

Rhodnius neglectus is a potential vector of Trypanosoma cruzi (Tc), the causative agent of Chagas disease. The salivary glands (SGs) and intestine (INT) are actively required during blood feeding. The saliva from SGs is injected into the vertebrate host, modulating immune responses and favoring feeding for INT digestion. Tc infection significantly alters the physiology of these tissues; however, studies that assess this are still scarce. This study aimed to gain a better understanding of the global transcriptional expression of genes in SGs and INT during fasting (FA), fed (FE), and fed in the presence of Tc (FE + Tc) conditions. In FA, the expression of transcripts related to homeostasis maintenance proteins during periods of stress was predominant. Therefore, the transcript levels of Tret1-like and Hsp70Ba proteins were increased. Blood appeared to be responsible for alterations found in the FE group, as most of the expressed transcripts, such as proteases and cathepsin D, were related to digestion. In FE + Tc group, there was a decreased expression of blood processing genes for insect metabolism (e.g., Antigen-5 precursor, Pr13a, and Obp), detoxification (Sult1) in INT and acid phosphatases in SG. We also found decreased transcriptional expression of lipocalins and nitrophorins in SG and two new proteins, pacifastin and diptericin, in INT. Several transcripts of unknown proteins with investigative potential were found in both tissues. Our results also show that the presence of Tc can change the expression in both tissues for a long or short period of time. While SG homeostasis seems to be re-established on day 9, changes in INT are still evident. The findings of this study may be used for future research on parasite-vector interactions and contribute to the understanding of food physiology and post-meal/infection in triatomines.

Association of recurrent upper respiratory tract infections with low production of oxygen intermediates in children.

OBJECTIVES: Upper respiratory tract infections in children generally have significant morbidity and mortality. There is little data available about functional immaturity of the immune system and the child's susceptibility to infections at the beginning of their lives, thus, justifying a more specific immunological analysis. METHOD: Analysis of hemograms and innate and adaptive immune responses in 95 children between age 1 to 6 years with episodes of recurrent respiratory infections (test group n = 39) and without these episodes (control group n = 56) was carried out. The production of reactive oxygen intermediates by peripheral blood cells stimulated by phorbol myristate acetate was analyzed. Additionally, the number of B lymphocytes, auxiliary T lymphocytes, and cytotoxic cells was determined using flow cytometry. RESULTS: Results from both groups did not show statistically significant differences in red blood cells, total leukocytes count, and the differential neutrophils, eosinophils, basophils, lymphocytes, and monocytes count. The analysis of the number of B lymphocytes, auxiliary T lymphocytes (LTCD4), and cytotoxic cells (LTCD8) also did not show any difference between both groups. However, the production of radical oxygen intermediates was significantly reduced in the test group as compared to the control group (p < 0.05). CONCLUSIONS: There was no difference in the analysis of hemograms, leukograms, or the number of lymphocytes, LTCD4, LTCD8, or LTCD19. The reduced production of oxygen intermediates in the affected group suggests that these children's microbicide capacity is compromised, which may be related to their recurrent respiratory infections.