This work reports the synthesis, structure and catalytic activity of a novel ruthenium(II) complex, [RuCl(dppb)(44bipy)(4-pic)]PF6 (where dppb = 1,4-bis(diphenylphosphine)butane; 44bipy = 4,4’-dimethyl-2,2’-dipyridyl; 4-pic = 4-picoline). The molecular structure and catalytic activity were studied by Fourier transform infrared (FTIR), UV-Vis and nuclear magnetic resonance (NMR) spectroscopies, cyclic voltammetry, and X-ray crystallography, while the electronic structure was investigated by density-functional theory (DFT) and time dependent DFT (TD-DFT) methods. Electrochemical studies showed the substitution of the chlorido ligand from the precursor by the 4-pic ligand, exhibiting the RuII/RuIII process at 1.21 V. The structure of the compound was optimized using DFT simulations and showed data similar to the X-ray structure. The UV-Vis absorption spectrum showed a good agreement with TD-DFT simulations. The highest occupied molecular orbital (HOMO) and the lowest unoccupied molecular orbital (LUMO) energies were determined at the Becke, 3-parameter, Lee-Yang-Parr (B3LYP) level. The study of the catalytic activity in the transfer hydrogenation of ketones by the 1H NMR showed efficient transfer hydrogenation reaction at 60 ºC, employing acetophenone as substrate and resulting in a high conversion. The formation of two ruthenium-hydride species was observed.

RESUMO A fase de maturação de ramos é importante no cultivo de mangueira porque precede à indução floral, quando as plantas estão sob estresse causado por elevadas temperaturas e baixa disponibilidade hídrica, que poderia ser amenizado pelo uso de bioestimulante. Assim, o presente estudo teve como objetivo utilizar um bioestimulante de plantas contendo extrato de levedura e aminoácidos na atenuação do estresse abiótico em plantas de manga, cv. Tommy Atkins, em ambiente semiárido. O delineamento experimental foi em blocos ao acaso, com cinco tratamentos, cinco repetições e cinco plantas por parcela. Os tratamentos consistiram de: T1) duas pulverizações foliares com [bioestimulante + KCl] + duas pulverizações foliares com K2SO4; T2) sem bioestimulante e quatro pulverizações foliares com K2SO4; T3) três pulverizações foliares individuais com bioestimulante e uma pulverização foliar com K2SO4; T4) duas pulverizações foliares com bioestimulante e duas pulverizações foliares com K2SO4; e T5) duas pulverizações foliares com [bioestimulante + K2SO4] + uma pulverização foliar com K2SO4. As variáveis avaliadas foram carboidratos solúveis, amido, concentração de aminoácidos e prolina, e atividade enzimática da ascobarto peroxidase e catalase. A pulverização foliar com bioestimulante durante a fase de maturação da parte aérea das mangueiras cultivadas no semiárido tropical aliviou o stress abiótico das plantas. Três pulverizações foliares de bioestimulante e uma pulverização foliar de K2SO4 são recomendadas para mitigar os efeitos do estresse abiótico em plantas de mangas no semiárido.

ABSTRACT The shoot maturation phase is important for growing mango tree because it precedes the floral induction, when plants are under stress caused by high temperatures and low water availability, that could be reduced by using plant biostimulant. Thus, the current study aimed to use a plant biostimulant containing yeast extract and amino acids to alleviate abiotic stress in mango plants, cv. Tommy Atkins, grown in semiarid environment. The experimental design consisted of randomized blocks with five treatments, five repetitions and five plants per plot. Treatments consisted of: T1) two foliar sprays with [biostimulant + KCl] + two foliar sprays with K2SO4; T2) No biostimulant and four foliar sprays with K2SO4; T3) three individual foliar sprays with biostimulant and one foliar spray with K2SO4; T4) two foliar sprays with biostimulant and two foliar sprays with K2SO4; and T5) two foliar sprays with [biostimulant + K2SO4] + one foliar spray with K2SO4. The variables evaluated were: i) leaf concentrations of soluble carbohydrates, starch, amino acids and proline; and ii) enzymatic activity of catalase and ascorbate peroxidase. The foliar spray with biostimulant during the branch maturation phase of mango trees grown in tropical semiarid environment alleviated plant abiotic stress. Three foliar biostimulant sprays and one K2SO4spray are recommended to alleviate mango plant abiotic stress in semiarid environment.

Resumo: A resposta germinativa de sementes submetidas à condição de estresses artificiais é uma ferramenta para melhor entendimento da capacidade de sobrevivência e adaptação das espécies em condições de estresses naturais. Objetivou-se avaliar o efeito protetor do óxido nítrico durante a germinação e vigor de sementes e desenvolvimento de plântulas de Eucalyptus urophylla sob condições de estresse salino. O delineamento foi inteiramente casualizado, com cinco repetições, em esquema fatorial 3 x 3 + 1, sendo três condicionantes (água, nitroprussiato de sódio - SNP e nitrato de potássio), três condições de germinação (água destilada, e os potenciais de -0,6 e -1,2 MPa), tendo como tratamento adicional, o controle (semente não condicionada). Determinou-se: contagem da germinação aos sete e quatorze dias, índice de velocidade de germinação, comprimento da raiz primária, de parte aérea e total. O SNP protege as sementes possibilitando maior porcentagem de germinação, assim como promove maior crescimento de raiz e tamanho total de plântula, já o KNO3 não é eficaz protegendo as sementes, as quais sofrem com estresse salino, o que afeta suas características fisiológicas e morfológicas. Sementes de E. urophylla são sensíveis ao estresse salino e o condicionamento fisiológico com SNP promove o aumento da porcentagem de germinação, vigor e desenvolvimento de plântulas sob condições de salinidade.

Abstract: The germination response of seeds under artificial stress conditions is a tool for better understanding of the survival and adaptation ability of species under natural stress conditions. The aims of this study were to evaluate the protective effect of nitric oxide during germination as well as seed vigor and seedling development of Eucalyptus urophylla under salt stress conditions. The experimental design was completely randomized, with five replications, in a 3 × 3 + 1 factorial arrangement, with three priming factors [water, sodium nitroprusside (SNP), and potassium nitrate (KNO3)], three germination conditions (distilled water, and the water potentials of -0.6 and -1.2 MPa), and an additional control treatment (unprimed seeds). The following determinations were made: germination count at seven and fourteen days, germination speed index, primary root length, shoot length, and total length. SNP protects seeds, leading to a higher percentage of germination, as well as greater root growth and total seedling size, whereas KNO3 is not effective in protecting seeds that suffer from salt stress, which affects their physiological and morphological characteristics. E. urophylla seeds are sensitive to salt stress, and physiological priming with SNP leads to an increase in the percentage of germination, vigor, and seedling development under salinity conditions.

RESUMO O presente estudo investigou as concepções e práticas de Promoção da Saúde dos profissionais das nove Unidades Básicas de Saúde (UBS) que constituem campo de estágio do curso de Medicina da Universidade do Estado do Rio Grande do Norte (UERN), na cidade de Mossoró (RN), discutindo-se os achados na perspectiva das novas tendências em educação médica, Saúde e Atenção. Trata-se de um estudo exploratório com abordagem qualitativa, aplicando-se a técnica de análise temática para análise de dados. Os sujeitos da pesquisa foram 25 profissionais que atuam na Estratégia Saúde da Família (ESF). Os resultados revelaram três tendências conceituais: Promoção da Saúde assimilada como prevenção de doenças; concepção difusa sobre Promoção da Saúde; e caracterização apropriada. Entre as práticas, prevaleceram as palestras, realizadas nas UBS com grupos de pacientes, no contexto de ações e programas, como Hiperdia, idosos e grávidas, e as orientações individuais, proporcionadas tanto nas UBS, quanto durante as visitas domiciliares. Entre os principais desafios postos à Promoção da Saúde foram constatados: persistência do modelo biomédico, déficit de recursos humanos, excesso de demanda e ausência de mecanismos de qualificação, que atuam como fatores de fragilização e fragmentação das equipes. Conclui-se que é necessário intensificar os esforços para uma construção dialogada entre Ensino, Serviço, Gestão em Saúde e a sociedade. No campo da educação médica, destaca-se a disponibilidade de instrumentos que amparam a articulação entre as instituições formadoras e os serviços de saúde e oferecem mecanismos para uma formação integrada e a Educação Permanente. Reafirma-se o papel das escolas médicas, empenhadas em dar concretude aos propósitos da Promoção da Saúde, harmonizados com o modelo dialógico da educação, para a formação de profissionais médicos com o perfil que a sociedade precisa, em favor de uma vida mais saudável e de uma sociedade melhor.

ABSTRACT The present study investigated the concepts and practices related to health promotion among professionals from nine Basic Health Units - BHU, that constitute the internship field of the Medical course of Rio Grande do Norte State University - UERN, in the town of Mossoró/RN. The findings are discussed from the perspective of new trends in Medical Education, Health and Care. This is an exploratory study with a qualitative approach, applying the thematic analysis technique for data analysis. The research subjects were twenty-five professionals who work in the Family Health Strategy - FHS. The results revealed three conceptual tendencies: Health Promotion assimilated as a form of disease prevention, a diffused concept of Health Promotion and, finally, an appropriate characterization. The practices included lectures with groups of patients, in the context of actions and programs, such as Hiperdia (addressing hypertension), health of the elderly and pregnant, and individual guidelines, provided both at the BHU and during home visits. The main challenges identified for health promotion included: the persistence of the biomedical model, the human resources deficit, the excess demand and absence of qualification mechanisms, which contribute toward team fragility and fragmentation. In conclusion, it is necessary to intensify efforts toward achieving a dialogical construction between Teaching, Services, Health Management and the Society, highlighting in the field of Medical Education the availability of instruments that support coordination between training institutions and the Health Services and offer mechanisms for integrated training and permanent education. The role of medical schools is reasserted: committed to consolidating the purposes of Health Promotion, aligned to the dialogical model of education for training medical professionals with a profile that society needs, and in favor of a healthier life and a better society.

RESUMOOBJETIVOSEstudar a expressão das proteínas Bcl-2, Bcl-x, assim como a presença da caspase-3 clivada em neurofibromas e tumores malignos da bainha do nervo periférico. A expressão de Bcl-2 e Bcl-x e a presença da caspases-3 clivada foram comparadas com as características clinicopatológicas dos tumores malignos da bainha do nervo periférico e seu impacto nas curvas de sobrevida também foi investigado.MATERIAIS E MéTODOSA avaliação das proteínas Bcl-2, Bcl-x e caspases-3 clivada foi realizada em 28 tumores malignos da bainha do nervo periférico e 38 neurofibromas, por imuno-histoquímica, utilizando microarrays de tecidos. A imunoquantificação foi realizada por análise computadorizada de imagem digital.CONCLUSÕESA apoptose está alterada nos neurofibromas e principalmente em tumores malignos da bainha do nervo periférico. Altos níveis de caspase-3 clivada é mais comum em tumores com características histopatológicas mais agressivas e estão associados com baixa sobrevida livre de doença em indivíduos com tumor maligno da bainha do nervo periférico.

ABSTRACTAIMSTo study the expression of Bcl-2, Bcl-x, as well the presence of cleaved caspase-3 in neurofibromas and malignant peripheral nerve sheath tumors. The expression of Bcl-2 and Bcl-x and the presence of cleaved caspase 3 were compared to clinicopathological features of malignant peripheral nerve sheath tumors and their impact on survival rates were also investigated.MATERIALS AND METHODSThe evaluation of Bcl-2, Bcl-x and cleaved caspase-3 was performed by immunohistochemistry using tissue microarrays in 28 malignant peripheral nerve sheath tumors and 38 neurofibromas. Immunoquantification was performed by computerized digital image analysis.CONCLUSIONSApoptosis is altered in neurofibromas and mainly in malignant peripheral nerve sheath tumors. High levels of cleaved caspase-3 are more common in tumors with more aggressive histological features and it is associated with lower disease free survival of patients with malignant peripheral nerve sheath tumors.

OBJETIVO: Há pouca informação sobre alterações da função glomerular após o tratamento cirúrgico do hiperparatireoidismo primário. O efeito agudo sobre a função renal foi estudado após algumas operações em cirurgia de cabeça e pescoço. MATERIAIS E MÉTODOS: Análise retrospectiva dos níveis de creatinina e da taxa de filtração glomerular estimada (eGFR). Os valores pré-operatórios foram comparados aos valores disponíveis até 72 horas após a operação. RESULTADOS: No hiperparatireoidismo terciário, os valores médios pré e pós-operatórios da eGFR foram 57,7 mL/min e 40,8 mL/min (p < 0,0001), respectivamente. O decréscimo após paratireoidectomia por hiperparatireoidismo primário foi de 85,4 mL/min para 64,3 mL/min (p < 0,0001). Após operações maiores de cabeça e pescoço, houve leve elevação da eGFR (de 94,3 mL/min para 105,4 mL/min, p = 0,002). CONCLUSÕES: A paratireoidectomia pode ser seguida de uma redução transitória na eGFR que não é frequentemente observada após outras operações em cabeça e pescoço.

OBJECTIVE: Little information is available on glomerular function changes after surgical treatment of primary hyperparathyroidism. The acute effects of some head and neck operations on renal function were studied. MATERIAL AND MATHODS: Retrospective analysis of changes in creatinine levels and estimated glomerular filtration rate (eGFR) after surgery. Preoperative values were compared with values available until 72 hours after the operation. RESULTS: In tertiary hyperparathyroidism, mean preoperative and postoperative eGFR values were 57.7 mL/min and 40.8 mL/min (p < 0.0001), respectively. A similar decrease was observed after parathyroidectomy for primary hyperparathyroidism, from 85.4 mL/min to 64.3 mL/min (p < 0.0001). After major head and neck procedures, there was a slight increase in eGFR (from 94.3 mL/min to 105.4 mL/min, p = 0.002). CONCLUSION: Parathyroidectomy may be followed by a transient decrease in eGFR that is not often observed in other head and neck operations.

Morphological components and chemical composition of Mimosa caesalpiniifolia Benth plants submitted to phosphorus fertilization and at different season were evaluated. The experiment was conducted at the Itambé Experimental Station of Pernambuco Agronomical Institute. Statistical analysis assumed a randomized block design, with split-plot treatment design composed by phosphorus levels (0, 100 and 200 kg of P2O5 per hectare) as main plots and evaluation season (dry and rainy) as split-plots. Experimental area was a sabiá woodlot, approximately 13 years old, measuring 0.3 ha with plant spacing of 3.0 x 3.0 m and 210 plants. Each experimental plot comprised one plant surrounded by eight competitive plants, not submitted to the treatments. Morphological evaluations were conducted at six periods, with 60 days interval, when leaves and branches up to 5 mm diameter were collected. Phosphorus effect was observed only for branch length, being 202.1, 193.6 and 173.5 cm for 0, 100 and 200 kg P2O5/ha, respectively. For the remaining variables, effects were only observed for evaluation period, with average values of 195.3 cm, 24.6, 8.8 mm and 3.8 for plant height, branch number and diameter, and thorn number, respectively. Interaction between evaluation period and phosphorus fertilization was observed only for NDF of branches, and both period and phosphorus fertilization on tannin content of branches.

Foram avaliados os componentes morfológicas e composição química de plantas de Mimosa caesalpiniifolia Benth submetidas a adubação fosfatada e em diferentes épocas do ano. O experimento foi conduzido na Estação Experimental de Itambé do Instituto Agronômico de Pernambuco. Foi utilizado delineamento em blocos ao acaso em parcelas subdivididas, sendo os níveis de fósforo (0, 100 e 200 kg de P2O5/ha) como parcelas e época de avaliação (seca e chuvosa) como subparcelas. A área experimental foi um bosque de sabiá com aproximadamente 13 anos e área de 0,3 ha com espaçamento 3,0 x 3,0 m, constituído de 210 plantas. Cada parcela experimental foi representada por uma planta circundada por oito plantas competitivas, que não receberam os tratamentos. As avaliações morfológicas foram realizadas em seis períodos com intervalos de 60 dias, quando foram realizadas coletas de folhas e ramos com diâmetro de até 5 mm. Observou-se efeito da adubação fosfatada apenas para comprimento dos ramos, sendo de 202,1; 193,6 e 173,5 cm para 0, 100 e 200 kg P2O5/ha, respectivamente. Para as demais variáveis, observou-se efeito somente do período de avaliação, tendo valores médios de 195,3 cm; 24,6; 8,8 mm e 3,8 para altura, número de brotações, espessura de ramos e número de acúleos, respectivamente. Observou-se interação entre período de avaliação e adubação fosfatada apenas para a FDN dos ramos e efeito tanto do período quanto da adubação fosfatada sobre o teor de tanino nos ramos. A adubação fosfatada não influenciou a maioria dos componentes morfológicas e a composição química das plantas de sabiá.

Avaliou-se o efeito do bissulfato de sódio, aplicado sobre a cama de frangos, criados em diferentes densidades, na sobrevivência de Escherichia coli e coliformes, utilizando-se as densidades de 12, 16 e 20 aves/m², com a inoculação de uma cepa de E. coli. Houve maior desenvolvimento microbiano no 21º dia de criação, com tendência de redução a partir daí. A eficácia do bissulfato de sódio foi maior nos primeiros dias do experimento.

The effect of sodium bisulfate has been evaluated on survival of Escherichia coli and coliforms, when applied on the broiler beds, adopting different densities. It has been adopted densities of 12, 16 and 20 birds/m², using inoculations of E. coli strains. The results have shown the highest microbial development on the 21st day of inoculation, with a trend of a microbial reduction afterwards. The sodium bisulfate was efficient during the first days of analyses, reducing its efficacy during the experiment.

Chronic Chagas' disease cardiomyopathy (CCC) is an often fatal outcome of Trypanosoma cruzi infection, with a poorer prognosis than other cardiomyopathies. CCC is refractory to heart failure treatments, and is the major indication of heart transplantation in Latin America. A diffuse myocarditis, plus intense myocardial hypertrophy, damage and fibrosis, in the presence of very few T. cruzi forms, are the histopathological hallmarks of CCC. To gain a better understanding of the pathophysiology of CCC, we analyzed the protein profile in the affected CCC myocardium. Homogenates from left ventricular myocardial samples of end-stage CCC hearts explanted during heart transplantation were subjected to two-dimensional electrophoresis with Coomassie blue staining; protein identification was performed by MALDI-ToF mass spectrometry and peptide mass fingerprinting. The identification of selected proteins was confirmed by immunoblotting. We demonstrated that 246 proteins matched in gels from two CCC patients. They corresponded to 112 distinct proteins. Along with structural/contractile and metabolism proteins, we also identified proteins involved in apoptosis (caspase 8, caspase 2), immune system (T cell receptor ß chain, granzyme A, HLA class I) and stress processes (heat shock proteins, superoxide dismutases, and other oxidative stress proteins). Proteins involved in cell signaling and transcriptional factors were also identified. The identification of caspases and oxidative stress proteins suggests the occurrence of active apoptosis and significant oxidative stress in CCC myocardium. These results generated an inventory of myocardial proteins in CCC that should contribute to the generation of hypothesis-driven experiments designed on the basis of the classes of proteins identified here.

OBJETIVO: analisar o efeito da cisaprida e da fisioterapia respiratória em lactentes chiadores (LC), com doença do refluxo gastroesofágico (DRGE). MÉTODOS: avaliamos, prospectivamente, em 13 LC com DRGE e 12 sem DRGE, a densidade nuclear de tecnécio (99Tc) em 3 topografias esofágicas. Os 2 grupos foram submetidos à investigação clínica, exames laboratoriais, radiológicos e cintilográficos para investigação etiológica da síndrome do LC e DRGE. A técnica fisioterápica denominada aceleração de fluxo expiratório (AFE) foi realizada antes e após tratamento com cisaprida. O tempos totais de RGE(TTRGE), primeiramente durante a cintilografia basal, e em seguida, durante a AFE, foram analisados e somados, para cada topografia esofágica. RESULTADOS: a cisaprida diminuiu o TTRGE, com significância estatística somente no terço superior do esôfago (p < 0,05) e não influenciou o TTRGE durante a AFE. Após tratamento com cisaprida, a AFE causou aumento do TTRGE nas topografias esofágicas média e superior, porém sem significância estatística. Lactentes com DRGE, antes do tratamento com cisaprida, tiveram menor TTRGE em esôfago distal durante a AFE (P < 0,05). Após tratamento com cisaprida, essa significância estatística deixou de existir. Os LC sem DRGE também apresentaram menor TTRGE em esôfago distal durante a AFE (P < 0,05). Os LC com DRGE apresentaram maior TTRGE em esôfago distal (P < 0,05), antes e após tratamento com cisaprida, tanto durante a cintilografia basal como durante a AFE. CONCLUSÃO: a cisaprida foi eficaz na diminuição do TTRGE em LC com doença do RGE, principalmente no terço superior do esôfago. A fisioterapia respiratória, segundo a técnica de AFE, foi potencialmente refluxogênica. Outros estudos são necessários para investigar os efeitos da fisioterapia respiratória segundo posições corporais.

OBJECTIVE: to evaluate the effect of cisapride and chest physical therapy on the gastroesophageal reflux of wheezing babies. METHODS: we prospectively assessed the presence of technetium (99Tc) in the upper, middle, and lower esophagus of 25 wheezing babies (13 with GERD and 12 without GERD) using scintigraphy. Both groups underwent clinical investigation, including laboratory, X-ray and scintigraphy tests, for the etiology of the wheezing baby syndrome (WBS) and GERD. Expiratory Flow Acceleration (EFA) was performed before and after treatment with cisapride. The total time of GER episodes was accounted for each portion of the esophagus during scintigraphy and during EFA. RESULTS: cisapride significantly reduced the total reflux time in the upper esophagus (P < 0.05), but showed no influence during EFA. After cisapride therapy, EFA increased the total reflux time in the upper and medium esophagus; however, no statistical significance was found. Infants with GERD presented a shorter total reflux time in the distal esophagus (P<0.05) during EFA. After cisapride treatment, no statistical significance was found. Infants without GERD also presented reduced total reflux time in the distal esophagus during EFA (P < 0.05). Those with GERD had increased total reflux time in the distal esophagus (P < 0.05) before and after cisapride treatment during EFA and scintigraphy. CONCLUSIONS: cisapride was effective in reducing the total reflux time, mainly in the upper esophagus. EFA apparently increased the number of episodes of GER, without achieving statistical significance. Further studies are necessary to investigate the effects of chest physical therapy according to body positions.

The target of any immunization is to activate and expand lymphocyte clones with the desired recognition specificity and the necessary effector functions. In gene, recombinant and peptide vaccines, the immunogen is a single protein or a small assembly of epitopes from antigenic proteins. Since most immune responses against protein and peptide antigens are T-cell dependent, the molecular target of such vaccines is to generate at least 50-100 complexes between MHC molecule and the antigenic peptide per antigen-presenting cell, sensitizing a T cell population of appropriate clonal size and effector characteristics. Thus, the immunobiology of antigen recognition by T cells must be taken into account when designing new generation peptide- or gene-based vaccines. Since T cell recognition is MHC-restricted, and given the wide polymorphism of the different MHC molecules, distinct epitopes may be recognized by different individuals in the population. Therefore, the issue of whether immunization will be effective in inducing a protective immune response, covering the entire target population, becomes an important question. Many pathogens have evolved molecular mechanisms to escape recognition by the immune system by variation of antigenic protein sequences. In this short review, we will discuss the several concepts related to selection of amino acid sequences to be included in DNA and peptide vaccines.

The hallmark of chronic Chagas' disease cardiomyopathy (CCC) is the finding of a T cell-rich inflammatory mononuclear cell infiltrate in the presence of extremely few parasites in the heart lesions. The scarcity of parasites in affected heart tissue casts doubt on the direct participation of Trypanosoma cruzi in CCC heart tissue lesions, and suggests the possible involvement of autoimmunity. The cells in the infiltrate are presumably the ultimate effectors of tissue damage, and there is evidence that such cells recognize cardiac myosin in molecular mimicry with T. cruzi proteins rather than primary reactivity to T. cruzi antigens (Cunha-Neto et al. (1996) Journal of Clinical Investigation, 98: 1709-1712). Recently, we have studied heart-infiltrating T cells at the functional level. In this short review we summarize the studies about the role of cytokines in human and experimental T. cruzi infection, along with our data on heart-infiltrating T cells in human Chagas' cardiomyopathy. The bulk of evidence points to a significant production of IFN-<FONT FACE="Symbol">g</font> and TNF-<FONT FACE="Symbol">a</font> which may be linked to T. cruzi-induced IL-12 production

Previous reports from our group have demonstrated the association of molecular mimicry between cardiac myosin and the immunodominant Trypanosoma cruzi protein B13 with chronic Chagas' disease cardiomyopathy at both the antibody and heart-infiltrating T cell level. At the peripheral blood level, we observed no difference in primary proliferative responses to T. cruzi B13 protein between chronic Chagas' cardiopathy patients, asymptomatic chagasics and normal individuals. In the present study, we investigated whether T cells sensitized by T. cruzi B13 protein respond to cardiac myosin. T cell clones generated from a B13-stimulated T cell line obtained from peripheral blood of a B13-responsive normal donor were tested for proliferation against B13 protein and human cardiac myosin. The results showed that one clone responded to B13 protein alone and the clone FA46, displaying the highest stimulation index to B13 protein (SI = 25.7), also recognized cardiac myosin. These data show that B13 and cardiac myosin share epitopes at the T cell level and that sensitization of a T cell with B13 protein results in response to cardiac myosin. It can be hypothesized that this also occurs in vivo during T. cruzi infection which results in heart tissue damage in chronic Chagas' disease cardiomyopathy