Lúcio Roberto Castellano

Immunological and genetic evidence for a crucial role of IL-10 in cutaneous lesions in humans infected with Leishmania braziliensis.

In populations exposed to Leishmania braziliensis, certain subjects develop skin ulcers, whereas others are naturally protected against cutaneous leishmaniasis. We have evaluated which cytokines are most crucial in the development of skin lesions. We found that active lesions occur in subjects with polarized Th2 or mixed Th1/Th2 responses, both associated with elevated IL-10 production. IL-10 was strongly associated (p = 0.004, odd ratio (OR) = 6.8, confidence interval = 1.9–25) with lesions, excluding IFN-γ, IL-12, TNF, IL-13, and IL-4 from the regression model. IL-10 was produced by blood monocytes and CD4+CD25+ T lymphocytes (mostly Foxp3+). However, we did not observe any difference between the number of these cells present in the blood of subjects with active lesions and those present in resistant subjects. Genetic analysis of the IL10−819C/T polymorphism, located in the IL10 promoter, showed that the C allele increased the risk of lesions (OR = 2.5 (1.12–5.7), p = 0.003). Functional analysis of these variants showed allele-specific binding of nuclear factors. The IL10-819C/C genotype was associated with higher levels of IL-10 than C/T and T/T genotypes. These observations demonstrate an important role for IL-10 in skin lesions in humans infected with L. braziliensis, and identify circulating monocytes and Tregs as principal sources of IL-10 in these patients.

Th1/Th2 immune responses are associated with active cutaneous leishmaniasis and clinical cure is associated with strong interferon-γ production

In leishmaniasis, Th1-related cytokines production seems to be crucial for host control of parasite burden and clinical cure. Visceral and diffuse cutaneous leishmaniasis are characterized by negative skin test for parasite antigens and failure to produce Th1 cytokines, whereas tegumentary leishmaniasis is characterized by positive skin test and the ability of peripheral blood mononuclear cells (PBMCs) to produce Th1 cytokines. In this study, specific antibody plasma levels and cytokine production in PBMC culture supernatants were evaluated by enzyme-linked immunoabsorbent assay in patients with active or cured cutaneous leishmanial lesions and in subjects without disease history living in the same endemic area. Higher tumor necrosis factor-alpha, interferon (IFN)-gamma, interleukin (IL)-12, IL-4, and IL-10 levels were observed in patients with active lesions, whereas cured subjects produced only IFN-gamma at elevated levels. Analysis of specific antibody isotypes correlate with cellular immune response observed in vitro, as the production of IgG1 and IgG3 was higher in patients with active lesions. Our results suggest the presence of a mixed Th1/Th2 response during active disease and that clinical cure is associated with a sustained Th1 response characterized by elevated IFN-gamma levels and down-modulation of IL-4 and IL-10 production.

Early-onset neonatal sepsis: cord blood cytokine levels at diagnosis and during treatment

OBJECTIVE To assess clinical and laboratory parameters and serum cytokine levels in 55 neonates who developed early-onset sepsis. METHODS Clinical parameters associated with early-onset neonatal sepsis were assessed. White blood cell differential and serum C-reactive protein and glucose levels were measured upon diagnosis of sepsis and 48 hours later. IL-beta, IL-10, IL-6, and TNF-α levels were measured in cord blood samples obtained on the day of diagnosis and from samples collected 48 and 96 hours after treatment onset. RESULTS Among newborns with early-onset sepsis, the length of hospital stay was inversely correlated with birth weight. Clinical parameters varied widely, especially body temperature. Blood glucose changes - particularly hypoglycemia - were common. Leukopenia, usually due to neutropenia, was the most prevalent change in blood cell count. C-reactive protein levels correlated with the immature-to-total neutrophil ratio. Serum TNF-α and IL-10 levels measured early in the course of sepsis were positively correlated with those detected in cord blood. CONCLUSIONS Clinical and laboratory parameters varied widely among neonates with sepsis in this sample. In neonates who presented with increased cytokine levels at birth, this abnormality persisted throughout the infectious process.

Autonomic nervous system modulation affects the inflammatory immune response in mice with acute Chagas disease

The aim of the present study was to evaluate the effects of changes to the autonomic nervous system in mice during the acute phase of Chagas disease, which is an infection caused by the parasite Trypanosoma cruzi. The following types of mice were inoculated with T. cruzi (CHG): wild‐type (WT) and vesicular acetylcholine transporter knockdown (KDVAChT) C57BL/6j mice; wild‐type non‐treated (NT) FVB mice; FVB mice treated with pyridostigmine bromide (PYR) or salbutamol (SALB); and β2‐adrenergic receptor knockout (KOβ2) FVB mice. During infection and at 18–21 days after infection (acute phase), the survival curves, parasitaemia, electrocardiograms, heart rate variability, autonomic tonus and histopathology of the animals were evaluated. Negative control groups were matched for age, genetic background and treatment. The KDVAChT‐CHG mice exhibited a significant shift in the electrocardiographic, autonomic and histopathological profiles towards a greater inflammatory immune response that was associated with a reduction in blood and tissue parasitism. In contrast, the CHG‐PYR mice manifested reduced myocardial inflammation and lower blood and tissue parasitism. Similar results were observed in CHG‐SALB animals. Unexpectedly, the KOβ2‐CHG mice exhibited less myocardial inflammation and higher blood and tissue parasitism, which were associated with reduced mortality. These findings could have been due to the increase in vagal tone observed in the KOβ2 mice, which rendered them more similar to the CHG‐PYR animals. In conclusion, our results indicate a marked immunomodulatory role for the parasympathetic and sympathetic autonomic nervous systems, which inhibit both the inflammatory immune response and parasite clearance during the acute phase of experimental Chagas heart disease in mice.

Antifungal activity, mode of action and anti-biofilm effects of Laurus nobilis Linnaeus essential oil against Candida spp.

OBJECTIVE The present study demonstrated the antifungal potential of the chemically characterized essential oil (EO) of Laurus nobilis L. (bay laurel) against Candida spp. biofilm adhesion and formation, and further established its mode of action on C. albicans. METHODS L. nobilis EO was obtained and tested for its minimum inhibitory and fungicidal concentrations (MIC/MFC) against Candida spp., as well as for interaction with cell wall biosynthesis and membrane ionic permeability. Then we evaluated its effects on the adhesion, formation, and reduction of 48hC. albicans biofilms. The EO phytochemical profile was determined by gas chromatography coupled to mass spectrometry (GC/MS). RESULTS The MIC and MFC values of the EO ranged from (250 to 500) μg/mL. The MIC values increased in the presence of sorbitol (osmotic protector) and ergosterol, which indicates that the EO may affect cell wall biosynthesis and membrane ionic permeability, respectively. At 2 MIC the EO disrupted initial adhesion of C. albicans biofilms (p<0.05) and affected biofilm formation with no difference compared to nystatin (p>0.05). When applied for 1min, every 8h, for 24h and 48h, the EO reduced the amount of C. albicans mature biofilm with no difference in relation to nystatin (p>0.05). The phytochemical analysis identified isoeugenol as the major compound (53.49%) in the sample. CONCLUSIONS L. nobilis EO has antifungal activity probably due to monoterpenes and sesquiterpenes in its composition. This EO may affect cell wall biosynthesis and membrane permeability, and showed deleterious effects against C. albicans biofilms.

An Overview of Molecular Mechanism of Nephrotic Syndrome

Podocytopathies (minimal change disease (MCD) and focal segmental glomerulosclerosis (FSGS)) together with membranous nephropathy are the main causes of nephrotic syndrome. Some changes on the expression of nephrin, podocin, TGF-β, and slit diaphragm components as well as transcription factors and transmembrane proteins have been demonstrated in podocytopathies. Considering the pathogenesis of proteinuria, some elucidations have been directed towards the involvement of epithelial-mesenchymal transition. Moreover, the usefulness of some markers such as TGF-β1, nephrin, synaptopodin, dystroglycans, and malondialdehyde have been determined in the differentiation between MCD and FSGS. Experimental models and human samples indicated an essential role of autoantibodies in membranous glomerulonephritis, kidney damage, and proteinuria events. Megalin and phospholipase-A2-receptor have been described as antigens responsible for the formation of the subepithelial immune complexes and renal disease occurrence. In addition, the complement system seems to play a key role in basal membrane damage and in the development of proteinuria in membranous nephropathy. This paper focuses on the common molecular changes involved in the development of nephrotic proteinuria.

Sepse neonatal precoce: níveis de citocinas no sangue de cordão umbilical no diagnóstico e durante o tratamento

OBJECTIVE: To assess clinical and laboratory parameters and serum cytokine levels in 55 neonates who developed early-onset sepsis. METHODS: Clinical parameters associated with early-onset neonatal sepsis were assessed. White blood cell differential and serum C-reactive protein and glucose levels were measured upon diagnosis of sepsis and 48 hours later. IL-1β, IL-10, IL-6, and TNF-α levels were measured in cord blood samples obtained on the day of diagnosis and from samples collected 48 and 96 hours after treatment onset. RESULTS: Among newborns with early-onset sepsis, the length of hospital stay was inversely correlated with birth weight. Clinical parameters varied widely, especially body temperature. Blood glucose changes - particularly hypoglycemia - were common. Leukopenia, usually due to neutropenia, was the most prevalent change in blood cell count. C-reactive protein levels correlated with the immature-to-total neutrophil ratio. Serum TNF-α and IL-10 levels measured early in the course of sepsis were positively correlated with those detected in cord blood. CONCLUSIONS: Clinical and laboratory parameters varied widely among neonates with sepsis in this sample. In neonates who presented with increased cytokine levels at birth, this abnormality persisted throughout the infectious process.

Role of nitric oxide in the development of cardiac lesions during the acute phase of experimental infection by Trypanosoma cruzi

Chagas disease is caused by Trypanosoma cruzi and the heart is the organ most affected. Nitric oxide has notable anti-Trypanosoma action, but with little evidence regarding its role in the mechanism for tissue injury. The objective of this study was to analyze the contribution of nitric oxide towards the development of inflammation and cardiac fibrosis during the acute phase of experimental infection by Y and Colombian strains of Trypanosoma cruzi. The inflammation was significantly more intense in animals infected with the Colombian strain, compared with those infected with the Y strain, both in C57BL/6 animals (3.98 vs 1.87%; p = 0.004) and in C57BL/6 animals deficient in inducible nitric oxide synthase (3.99 vs 2.4%; p = 0.013). The cardiac parasite load in inducible nitric oxide synthase-deficient C57BL/6 animals infected with the Colombian strain was significantly greater than in those infected with the Y strain (2.78 vs. 0.17 nests/mm(2); p = 0.004), and also significantly greater than in the C57BL/6 infected with both the Colombian strain (2.78 vs 1.33 nests/mm(2); p = 0.006) and Y strains (2.78 vs 0.53 nests/mm(2); p = 0.005). The data confirm that nitric oxide has a role in parasite load control and suggest that it has a role in tissue protection, through controlling inflammation and potentially reducing cardiac lesions during the acute phase of Chagas disease.

Evaluation of Hemagglutination Activity of Chitosan Nanoparticles Using Human Erythrocytes

Chitosan is a polysaccharide composed of randomly distributed chains of β-(1-4) D-glucosamine and N-acetyl-D-glucosamine. This compound is obtained by partial or total deacetylation of chitin in acidic solution. The chitosan-based hemostatic agents have been gaining much attention in the management of bleeding. The aim of this study was to evaluate in vitro hemagglutination activity of chitosan nanoparticles using human erythrocytes. The preparation of nanoparticles was achieved by ionotropic gelification technique followed by neutralization with NaOH 1 mol/L−1. The hemagglutination activity was performed on a solution of 2% erythrocytes (pH 7.4 on PBS) collected from five healthy volunteers. The hemolysis determination was made by spectrophotometric analysis. Chitosan nanoparticle solutions without NaOH addition changed the reddish colour of the wells into brown, suggesting an oxidative reaction of hemoglobin and possible cell lysis. All neutralized solutions of chitosan nanoparticles presented positive haemagglutination, without any change in reaction color. Chitosan nanoparticles presented hemolytic activity ranging from 186.20 to 223.12%, while neutralized solutions ranged from 2.56 to 72.54%, comparing to distilled water. Results highlight the need for development of new routes of synthesis of chitosan nanoparticles within human physiologic pH.

Does Scientific Evidence for the Use of Natural Products in the Treatment of Oral Candidiasis Exist? A Systematic Review

In view of the limitations of antifungal agents used in the treatment of oral candidiasis and the wide variety of natural products that have been studied as treatment of this disease, this systematic literature review proposed to evaluate whether scientific evidence attesting to the efficacy of natural products in the treatment of this disease exists. A systematic search in PubMed, MEDLINE, SciELO, Lilacs, and Cochrane Library databases was accomplished using the associations among the keywords Candida albicans, phytotherapy, biological products, denture stomatitis, and oral candidiasis in both English and Portuguese. Four independent observers evaluated the methodological quality of the resulting articles. Three studies were included for detailed analysis and evaluated according to the analysis protocol based on the CONSORT (Consolidated Standards of Reporting Trials) 2010 statement. The tested products were different in all studies. Two studies mentioned random samples, but no study described the sample allocation. No study mentioned sample calculations, a prior pilot study, or examiner calibration, and only one trial reported sample losses. Differences between the tested products and the methodological designs among these studies did not allow the existence of scientific evidence related to the effectiveness of these products for the proposed subjects to be confirmed.