Effect of benznidazole on cerebral microcirculation during acute Trypanosoma cruzi infection in mice.

Central nervous system alterations was described in Chagas disease in both human and experimental models, leading to meningoencephalitis, stroke and cognitive impairment. Recently, our group demonstrated that acute infection by Trypanossoma cruzi leads to cerebral microvasculophaty in mice with endothelial dysfunction, capillary rarefaction, increased rolling and leukocyte adhesion. Only benznidazole and nifurtimox are available for clinical treatment, they have an efficiency of 80% in the acute phase and less than 20% in chronic phase. However, the effect of these drugs on brain microcirculation has not yet been evaluated. We hypothesized that early treatment with benznidazole could protect brain microcirculation during acute experimental Chagas disease. Swiss Webster mice were inoculated with 104 trypomastigotes forms of T. cruzi, and after 24 h they were treated with 50 or 100 mg/kg/day of benznidazole for 14 consecutive days. In untreated infected mice, we observed cerebral microvascular rarefaction, increase in leukocyte rolling and adhesion, reduced cerebral blood flow, and increased CD3+ and F4-80+ cells in brain tissue. Early treatment with benznidazole at 100 mg/kg/day and 50 mg/kg/day prevented the occurrence of the alterations mentioned. Here, we show that BZ is able to protect the microcirculation and reduced brain inflammation in acute experimental Chagas disease.

TGF-ß receptor type II costameric localization in cardiomyocytes and host cell TGF-ß response is disrupted by Trypanosoma cruzi infection.

Transforming growth factor beta (TGF-ß) cytokine is involved in Chagas disease establishment and progression. Since Trypanosoma cruzi can modulate host cell receptors, we analysed the TGF-ß receptor type II (TßRII) expression and distribution during T. cruzi - cardiomyocyte interaction. TßRII immunofluorescent staining revealed a striated organization in cardiomyocytes, which was co-localized with vinculin costameres and enhanced (38%) after TGF-ß treatment. Cytochalasin D induced a decrease of 45·3% in the ratio of cardiomyocytes presenting TßRII striations, demonstrating an association of TßRII with the cytoskeleton. Western blot analysis showed that cytochalasin D significantly inhibited Smad 2 phosphorylation and fibronectin stimulation after TGF-ß treatment in cardiomyocytes. Trypanosoma cruzi infection elicited a decrease of 79·8% in the frequency of cardiomyocytes presenting TßRII striations, but did not interfere significantly in its expression. In addition, T. cruzi-infected cardiomyocytes present a lower response to exogenous TGF-ß, showing no enhancement of TßRII striations and a reduction of phosphorylated Smad 2, with no significant difference in TßRII expression when compared to uninfected cells. Together, these results suggest that the co-localization of TßRII with costameres is important in activating the TGF-ß signalling cascade, and that T. cruzi-derived cytoskeleton disorganization could result in altered or low TGF-ß response in infected cardiomyocytes.

Proteins involved on TGF-ß pathway are up-regulated during the acute phase of experimental Chagas disease.

Studies developed by our group in the last years have shown the involvement of TGF-ß in acute and chronic Chagas heart disease, with elevated plasma levels and activated TGF-ß cell signaling pathway as remarkable features of patients in the advanced stages of this disease, when high levels of cardiac fibrosis is present. Imbalance in synthesis and degradation of extracellular matrix components is the basis of pathological fibrosis and TGF-ß is considered as one of the key regulators of this process. In the present study, we investigated the activity of the TGF-ß signaling pathway, including receptors and signaling proteins activation in the heart of animals experimentally infected with Trypanosoma cruzi during the period that mimics the acute phase of Chagas disease. We observed that T. cruzi-infected animals presented increased expression of TGF-ß receptors. Overexpression of receptors was followed by an increased phosphorylation of Smad2/3, p38 and ERK. Furthermore, we correlated these activities with cellular factors involved in the fibrotic process induced by TGF-ß. We observed that the expression of collagen I, fibronectin and CTGF were increased in the heart of infected animals on day 15 post-infection. Correlated with the increased TGF-ß activity in the heart, we found that serum levels of total TGF-ß were significantly higher during acute infection. Taken together, our data suggest that the commitment of the heart associates with increased activity of TGF-ß pathway and expression of its main components. Our results, confirm the importance of this cytokine in the development and maintenance of cardiac damage caused by T. cruzi infection.

Use of haloperidol and risperidone in highly aggressive Swiss Webster mice by applying the model of spontaneous aggression (MSA).

Aggression is defined as the act in which an individual intentionally harms or injures another of their own species. Antipsychotics are a form of treatment used in psychiatric routine. They have been used for decades in treatment of patients with aggressive behavior. Haloperidol and risperidone promote the control of psychiatric symptoms, through their respective mechanisms of action. Experimental models are obtained by behavioral, genetic, and pharmacological manipulations, and use a reduced number of animals. In this context, we applied the model of spontaneous aggression (MSA), originating the presence of highly aggressive mice (AgR) when reassembled in adulthood. We administered haloperidol and risperidone in escalating doses, for ten consecutive days. Using positive and negative control groups, we evaluated the effectiveness of these drugs and the reversal of the aggressive behavior, performing the tail suspension test (TST) and open field test (OFT) on 10th day of treatment and 10 days after its discontinuation. The results showed that both antipsychotic drugs were effective in AgR and reversed the aggressive phenotype, reducing the number of attacks by AgR and the extent of lesions in the subordinate mice (AgD) exposed to the pattern of aggressive behavior (PAB) of the aggressors. This conclusion is based on the reduction in the animals' motor and exploratory activity, and on the reversal of patterns of aggressive behavior. The association between the MSA and experiments with other therapeutic protocols and different antipsychotics can be an important methodology in the study of aggressive behavior in psychiatric patients.

Selenium Treatment and Chagasic Cardiopathy (STCC): study protocol for a double-blind randomized controlled trial.

BACKGROUND: Heart disease progression occurs in 30% of patients with chronic Trypanosoma cruzi infection. Supplementation with selenium (Se) in animal model of T. cruzi infection produced promising results. There is evidence that patients with Chagas heart disease have lower Se levels than healthy individuals and patients with T. cruzi infection without of cardiac disease. The aim of this investigation is to estimate the effect of Se treatment on prevention of heart disease progression in patients with chagasic cardiopathy. METHODS: The Selenium Treatment and Chagasic Cardiopathy trial is a superiority, double-blind, placebo-controlled, randomized clinical trial. The eligibility criteria are as follows: (1) a Chagas disease diagnosis confirmed by serology; (2) segmental, mild or moderate global left ventricular systolic dysfunction; and (3) age between 18 and 65 years. The exclusion criteria are as follows: (1) pregnancy, (2) diabetes mellitus, (3) tobacco use, (4) alcohol abuse, (5) evidence of nonchagasic heart disease, (6) depression, (7) dysphagia with evidence of food residues in the esophagus, (8) dysphagia with weight loss higher than 15% of usual weight in the last four months and/or (9) conditions that may result in low protocol adherence. The intervention will be 100 µg of sodium selenite once daily for 365 consecutive days compared to placebo. The following are the primary outcomes to be measured: (1) the trajectories of the left ventricular ejection fraction in the follow-up period; (2) reduction of heart disease progression rates, with progression defined as a 10% decrease in left ventricular ejection fraction; and (3) rate of hospital admissions attributable to dysrhythmia, heart failure or stroke due to Chagas disease. One hundred thirty patients will be randomly allocated into either the intervention or placebo group at a ratio of 1:1. The sequence allocation concealment and blinding were planned to be conducted with the strategy of numbered boxes. Both patients and health-care providers will remain blinded to the intervention groups during the 5 years of follow-up. DISCUSSION: If Se treatment reduces the progression of Chagas cardiopathy, the inclusion of this micronutrient in the daily diet can improve the therapeutic regimen for this neglected tropical disease at low cost. TRIAL REGISTRATION: Clinical Trials.gov ID: NCT00875173 (registered 20 October 20 2008).

[The knowledge of chagasic patients about their disease: collective construction of a research instrument and test of its applicability]. / O saber do paciente chagásico sobre a sua doença: construção compartilhada de um instrumento para a pesquisa e teste de sua aplicabilidade.

This article describes the collective construction of a research instrument (interview guideline) for investigating the knowledge of chagasic patients attended at the Chagas Disease Reference Center of the Oswaldo Cruz Foundation. A multi-professional team worked sequentially on six versions of the guideline for semi-structured interviews. The instrument aims collecting data for a qualitative approach to concepts and perceptions of the patients from the perspective of the human relationships in the context of life and health. It detects the individual experiences regarding the diseasing process, the knowledge about the disease (and the infection), the emotions, reactions, and affections. Some theoretical aspects were discussed based on sociological and anthropological practices used in public health actions. We performed a complete interview with a patient for testing and adjusting the instrument. The interview guideline was tested and showed to be a suitable instrument for investigating the knowledge of chagasic patients, covering many subjective and cognitive aspects. This knowledge can be a useful contribution to the development of strategies, actions and information material aimed at improving and humanizing the care delivered to Chagas disease patients.

[Reflections about health and educational objects and physical environments]. / Reflexões sobre os objetos e os ambientes físicos de ensino e pesquisa em saúde.

This article looks to the objects and physical environments destined to teaching and research in health from a different perspective. It addresses the communication between the designers and the people that use their projects and investigates in which ways the designer can contribute to a positive transformation of the state of mind of the users of teaching and health environments, taking into account the reaction of people to the products and environments, especially manifestations of pleasure and well-being. The article presents a pilot edition of an instrument for sensitization and data collection in form of a workshop called "Environment, Creation and Pleasure".

Fas ligand-dependent inflammatory regulation in acute myocarditis induced by Trypanosoma cruzi infection.

Fas/Fas ligand (Fas-L) engagement, a potent inducer of apoptosis, is also important for cellular activation, regulation of effector and chemotactic activity, and secretion of chemokines and cytokines. We evaluated the relevance of Fas/Fas-L in the regulation of myocarditis induced by Trypanosoma cruzi infection and observed that in Fas-L(-/-) mice (gld/gld), cardiac infiltration was significantly reduced, accordingly showing less cardiomyocyte destruction. Fluorescence-activated cell sorting analysis of cardiac inflammatory cells showed higher numbers of CD8(+) T cells in BALB/c compared with gld/gld mice but similar levels of lymphocyte function-associated antigen-1, intercellular adhesion molecule, CD2, and CD69 expression; MAC-1(+) myeloid cells and mast cells were increased in BALB/c mice, whereas gld/gld mice exhibited an enrichment of CD4(+/low) T cells. Intracellular labeling of cytokines revealed no clear cardiac skewing of Th1 or Th2 responses, but we found a higher number of interleukin-10(+) cells in gld/gld mice and a deficient expression of vascular cell adhesion molecule-1 on cardiac endothelial cells in gld/gld mice. Finally, we found a population of CD3(+) but CD4/CD8 double negative cardiac T cells in both groups of infected mice, but down-regulation of some adhesion molecules and surface receptors was only observed in gld/gld mice, indicating a targeted T-cell population mostly affected by the lack of Fas-L engagement. These results point to a role for myocarditis regulation by Fas/Fas-L beyond its possible direct relevance in cellular death.