New Insights Into Blue Light Phototherapy in Experimental Trypanosoma cruzi Infection.

The search for an effective etiologic treatment to eliminate Trypanosoma cruzi, the causative agent of Chagas disease, has continued for decades and yielded controversial results. In the 1970s, nifurtimox and benznidazole were introduced for clinical assessment, but factors such as parasite resistance, high cellular toxicity, and efficacy in acute and chronic phases of the infection have been debated even today. This study proposes an innovative strategy to support the controlling of the T. cruzi using blue light phototherapy or blue light-emitting diode (LED) intervention. In in vitro assays, axenic cultures of Y and CL strains of T. cruzi were exposed to 460 nm and 40 µW/cm2 of blue light for 5 days (6 h/day), and parasite replication was evaluated daily. For in vivo experiments, C57BL6 mice were infected with the Y strain of T. cruzi and exposed to 460 nm and 7 µW/cm2 of blue light for 9 days (12 h/day). Parasite count in the blood and cardiac tissue was determined, and plasma interleukin (IL-6), tumoral necrosis factor (TNF), chemokine ligand 2 (CCL2), and IL-10 levels and the morphometry of the cardiac tissue were evaluated. Blue light induced a 50% reduction in T. cruzi (epimastigote forms) replication in vitro after 5 days of exposure. This blue light-mediated parasite control was also observed by the T. cruzi reduction in the blood (trypomastigote forms) and in the cardiac tissue (parasite DNA and amastigote nests) of infected mice. Phototherapy reduced plasma IL-6, TNF and IL-10, but not CCL2, levels in infected animals. This non-chemical therapy reduced the volume density of the heart stroma in the cardiac connective tissue but did not ameliorate the mouse myocarditis, maintaining a predominance of pericellular and perivascular mononuclear inflammatory infiltration with an increase in polymorphonuclear cells. Together, these data highlight, for the first time, the use of blue light therapy to control circulating and tissue forms of T. cruzi. Further investigation would demonstrate the application of this promising and potential complementary strategy for the treatment of Chagas disease.

Role of nucleic acid amplification assays in monitoring treatment response in chagas disease: Usefulness in clinical trials.

Chagas disease has become a global health problem due to migration of infected people out of Latin America to non-endemic countries. For more than 40 years, only the nitroimidazole compounds Benznidazole and Nifurtimox, have been used for specific treatment of Trypanosoma cruzi infection with disappointing results, specially due to the long duration of treatment and adverse events in the chronic phase. In the last years, ergosterol inhibitors have been also proposed for specific treatment. Different randomized clinical trials were performed for evaluating their treatment efficacy and safety. One of the greatest concerns in clinical trials is to provide an early surrogate biomarker of response to trypanocidal chemotherapy. Serological response is slow and the classical parasitological tests have poor sensitivity and are time-consuming. Nowadays, PCR is the most helpful tool for assessing treatment response in a short period of time. Different protocols of PCR have been developed, being quantitative real time PCR based on amplification of repetitive satellite or minicircle DNA sequences plus an internal amplification standard, the mostly employed strategies in clinical trials. Standardized protocols and the use of an external quality assessment ensure adequate technical procedures and reliable data. Clinical trials have shown a significant reduction in parasite loads, reaching undetectable DNA levels in bloodstream after specific treatment, however events of treatment failure have also been reported. Treatment failure could be due to inadequate penetrance of the drugs into the affected tissues, to the presence of primary or secondary drug resistance of the infecting strains as well as to the existence of dormant parasite variants reluctant to drug action. The early diagnosis of drug resistance would improve clinical management of Chagas disease patients, allowing dictating alternative therapies with a combination of existing drugs or new anti-T. cruzi agents. The aim of this review was to describe the usefulness of detecting T.cruzi DNA by means of real time PCR assays, as surrogate biomarker in clinical trials for evaluating new drugs for CD or new regimens of available drugs and the possibility to detect treatment failure.

The treatment with selenium increases placental parasitismin pregnant Wistar rats infected with the Y strain of Trypanosoma cruzi.

Selenium (Se) is an essential micronutrient in the diet of mammals and has an important role in the immune function. Selenium is a key element in selenoproteins involved in the in the maintenance of the antioxidant defense. Diet with selenium is beneficial for the treatment of diseases correlated with high levels of oxidative stress, also observed in the Chagas disease. Chagas disease is a neglected disease caused by the protozoan Trypanosoma cruzi and several research groups are focused on the illness treatment. Immunomodulation of the infection using microelements is an important tool to avoid deleterious effects of the Chagas disease. Therefore, our objective was to evaluate the effects of selenium supplementation on pregnant Wistar rats infected with T. cruzi. Selenium treatment stimulated the weight and length of fetuses and placentas allied to the decrease of blood parasitemia. However, selenium demonstrated a low influence on T cells, diminishing the B cell population (CD45RA+). Moreover, the production of pro-inflammatory cytokines was downregulated under selenium administration. Low pro-inflammatory cytokines levels probably are related to the increase in the number of amastigote nests in infected and treated animals. Thus, selenium supplementation during pregnancy could impair the local placental immune response. Further studies are necessary to assess the interaction between selenium and the acute Chagas' disease during pregnancy, which will base future supplementation strategies.

Evaluation of antioxidant therapy in experimental Chagas disease

Abstract INTRODUCTION: Stimulation of inflammatory mediators such as cytokines and chemokines may cause oxidative stress in Chagas disease. In this study, we evaluated the merit of vitamins C and E as antioxidant therapy to minimize the oxidative stress-induced damage in an experimental model of Chagas disease. METHODS: Ninety-six Swiss mice were infected with Trypanosoma cruzi QM2 and treated with vitamins C, E, or both (C/E) for 60 and 120 days, and their effects compared to placebo administration were evaluated in the acute and chronic disease phases. RESULTS: There was no difference in parasitemia among treatment groups. However, histological analysis showed more severe inflammation in the skeletal muscle in the vitamin supplementation groups at both the acute and chronic phases. Biochemical analyses during the acute phase showed increased ferric-reducing ability of plasma (FRAP) and glutathione (GSH) levels in the vitamin C and C/E groups. In the chronic phase, a decrease in GSH levels was observed in the vitamin E group and a decrease in thiobarbituric acid reactive substances (TBARS) was observed in the vitamin C/E group. Moreover, there was a decrease in TBARS in the cardiac tissues of the vitamin C and C/E groups compared to that of the placebo group, although this level was greater in the vitamin E group than in the vitamin C group. CONCLUSIONS: The antioxidant action of vitamins C and E reduced oxidative stress in both the acute and chronic phases of Chagas disease, with a marked effect from joint administration, indicating their inherent synergism.

Avaliação da atividade anti-Leishmania e anti-Trypanosoma do extrato etanólico das folhas de Annona squamosa L / Evaluation of the anti-leishmania and anti-trypanosoma activity of ethanolic extract from the leaves of Annona squamosa L

As doenças parasitárias, também chamadas de “doenças negligenciadas”, continuam sendo uma grande dificuldade para o desenvolvimento social e econômico dos países mais pobres. Podemos citar como exemplo dessas doenças, a leishmaniose e a doença de Chagas. A leishmaniose é causada por parasitas do gênero Leishmania e afeta cerca de 12 milhões de pessoas. A doença de Chagas, causada pelo protozoário Trypanosoma cruzi, causa aproximadamente 50.000 mortes por ano. Os fármacos disponíveis para o tratamento dessas doenças são altamente tóxicos, sendo este um dos motivos que leva à busca por drogas eficazes e seguras para seus tratamentos. As folhas da Annona squamosa, espécie da família Annonaceae, já foram descritas na literatura por suas atividades hepatoprotetora, antiparasitária, pesticida e antimicrobiana. Nesse estudo avaliamos a atividade anti-leishmania e tripanocida do extrato etanólico das folhas de Annona squamosa L. (EEAS) em formas promastigota do parasita Leishmania braziliensis e Leishmania infantum e epimastigota de Trypanosoma cruzi, além de avaliar a atividade citotóxica em fibroblasto. Os resultados demonstram que o extrato apresentou uma melhor atividade contra Leishmania infantum e Leishmania brasiliensis quando comparados com Trypanosoma cruzi; e que apresentou uma maior toxicidade nas concentrações de 500 e 1000 μg/ml, com mortalidade dos fibroblastos de aproximadamente 85% e 100%, respectivamente. Esse estudo aponta para uma perspectiva terapêutica alternativa que se mostrou eficaz frente aos parasitas aqui estudados, exceto a forma epimastigota de Trypanosoma cruzi. Com relação aos testes de citotoxicidade fazem-se necessários novos testes, uma vez que apresentou um alto nível de toxicidade, viabilizando assim futuros ensaios in vivo.

The parasitic diseases, also calls by “neglected diseases”, continue being a major difficulty for the social and economic development of the poorest countries. We can cite as an example of these diseases, the leishmaniasis and the Chagas disease. Leishmaniasis is caused by parasites of the genus Leishmania and affects about 12 million people. The Chagas disease, caused by the protozoan Trypanosoma cruzi, causes approximately 50,000 deaths per year. The drugs available for the treatment of these diseases are highly toxic, being this one of the reasons that leads to the search for effective and safe drugs for their treatments. The leaves of the Annona squamosa, species of the family Annonaceae, have already been described in the literature by their hepatoprotective activities, antiparasitic, pesticide and antimicrobial. In this study we assessed the activity tripanocidal and antileishmania of ethanolic extract from the leaves of Annona squamosa L. (EEAS) in promastigota forms of the parasite Leishmania braziliensis and Leishmania infantum and epimastigota of Trypanosoma cruzi, in addition to evaluating the cytotoxic activity in fibroblasts. The results demonstrate that the extract presented a better activity against Leishmania infantum and Leishmania brasiliensis when compared with Trypanosoma cruzi; and which presented a greater toxicity at concentrations of 500 and 1000 μg/ml, with mortality of fibroblasts of approximately 85% and 100%, respectively. This study points to an alternative therapeutic perspective that showed effective against the parasites here studied, except the epimastigota form of Trypanosoma cruzi. With relation to cytotoxicity tests are required new tests, once presented a high level of toxicity, thus enabling future in vivo assays.

Trypanosoma cruzi: biotherapy made from trypomastigote modulates the inflammatory response.

UNLABELLED: This study evaluates the effect of Trypanosoma cruzi biotherapy 17dH (BIOT) on mice of different ages, infected with the protozoa concerned. METHOD: Performing a blind, controlled, randomized by drawing experiment, 110 animals four or eight-week-old, Swiss, male mice were divided into infected control treated hydroalcoholic 7% (CI-4 = 34 or CI-8 = 21 animals) and infected control treated with biotherapy 17dH-0.2 mL/animal/20 consecutive days/oral regimen (BIOT-4 = 33 or BIOT-8 = 21 animals). Animals were inoculated intraperitoneally with 1400 trypomastigote, T. cruzi Y-strain. Parasitological, immunological and histopathologic parameters were evaluated statistically, using Statistica-8.0 and R 3.0.2 program to analysis of survival. The study was approved by the Ethics Committee for Animal Experimentation/UEM. RESULTS: Four-week-old mice showed no statistical difference in parasitemia (P = 0.5718) between the treated and control group. Eight-week-old mice from the treated group had a higher parasite peak (P = 0.0424) and higher parasitemia (P < 0.005) than the control. To both groups of 4 and 8 weeks of age, treated or untreated, survival of mice was higher in the treated group than in the control, although it was not statistically significant (p-value = 0.32, 0.55 respectively). Four-week-old mice displayed a spleen section with a number of amastigote nests significantly higher in BIOT-4 than CI-4 (P = 0.01). In eight-week-old mice the number of amastigote nests (P < 0.001) and inflammatory foci (P < 0.06-10% significance) in the liver section were smaller in BIOT-8 than CI-8. Spleen giant cells were significantly higher in CI-8 than in BIOT-8 (P < 0.01). Eight-week-old animals treated with biotherapy showed higher parasitemia and lower tissue parasitism. Opposite pattern was observed in four-week-old animals. CONCLUSION: There is a difference of high diluted medication effect in four and eight-week-old mice. In the group of animals 8 weeks the immunomodulatory effect seems to have been higher. Hence, treatment with the medicine produced from T. cruzi modulates the inflammatory response with increased apoptosis and decreased serum levels of TGF-ß.

Reposicionamento de fármacos e estudo de novas combinações terapêuticas no tratamento etiológico da doença de Chagas / Repositioning of drugs and study of new therapeutic combinations in the etiological treatment of Chagas disease

Dentre as doenças parasitárias tropicais, as causadas por protozoários se apresentam como um grande desafio para a saúde pública. Conhecida também como tripanossomíase americana, a doença de Chagas é encontrada principalmente em áreas endêmicas de 21 países da América Latina, com cerca de 8-10 milhões de pessoas infectadas. A quimioterapia utiliza medicamentos de elevada toxicidade, e no Brasil, restringe-se a um único fármaco, o benznidazol. Na busca por terapias alternativas, o reposicionamento de fármacos representa uma forma promissora para introdução de novos medicamentos. O presente trabalho teve como objetivo avaliar o potencial terapêutico contra T. cruzi de fármacos aprovados clinicamente, utilizando modelos in vitro e experimentais. Dentre os 54 fármacos testados, 17 apresentaram atividade contra formas tripomastigotas, com CE50 variando entre 1,8 a 81 µM, destacando-se a sertralina como o mais efetivo e o cloxazolam como o menos efetivo. Dentre 6 fármacos escolhidos, 5 demonstraram atividade contra os amastigotas intracelulares, com CE50 entre 1,4 a 32 µM, destacando-se a sertralina como o mais efetivo e o saquinavir como o menos efetivo. Realizou-se ainda um estudo de citotoxicidade, e o índice de seletividade dos fármacos variou entre 1,2 a 17. Por meio da construção de isobologramas, realizou-se um estudo in vitro de associação terapêutica contra formas tripomastigotas entre a nitazoxanida e a sertralina, resultando em uma combinação indiferente. A efetividade in vivo da sertralina e da nitazoxanida foi verificada em modelo de camundongos Swiss; apenas a nitazoxanida reduziu em 29% a parasitemia após 5 dias consecutivos de tratamento a 50 mg/kg. Finalmente, um estudo comparativo foi desenvolvido entre a técnica de qPCR e o método de Brener por contagem em microscopia óptica. Foi observada similaridade entre ambas as técnicas para avaliação da parasitemia no modelo murino...

Among tropical parasitic diseases, those caused by protozoans represent as a major challenge to public health. Also known as American trypanosomiasis, Chagas´s disease is found mainly in endemic areas of 21 countries of Latin America, with approximately 8-10 million people infected. The chemotherapy is based in highly toxic drugs with high toxicity and, in Brazil, it is restricted to a single drug, the benznidazole. In the search for alternative therapies, the repositioning of drugs represents a promising approch for the introduction of new medicines. This study aimed the evaluation of the therapeutic potential against T. cruzi of clinically approved drugs using in vitro and experimental models. Among the 54 tested drugs, 17 showed activity against trypomastigotes, with EC50 ranging from 1.8 to 81 µM; sertraline was the most effective drug and cloxazolam the least effective. Among 6 chosen drugs, 5 demonstrated activity against intracellular amastigotes with EC50 between 1.4 to 32 µM; sertraline as the most effective and saquinavir the least one. The mammalian cytotoxicity was also evaluated and selectivity index of drugs ranged from 1.2 to 17 µM. Through the construction of isobolograms, an in vitro study of combined therapy against trypomastigotes was performed with nitazoxanide and sertraline, resulting in an indifferent combination. The in vivo efficacy of nitazoxanide and sertraline was observed in Swiss mice model; nitazoxanide reduced by 29% the parasitemia after 5 consecutive days of treatment at 50 mg/kg. Finally, a comparative study was conducted between the qPCR technique and the method of Brener by light microscopy counting. A similar result was found for both techniques when evaluating the animals parasitemia in the murine model. The repositioning of approved drugs and their therapeutic associations could contribute to more effective and less toxic treatments for neglected diseases as Chagas disease...

Plantas medicinales en el tratamiento de la enfermedad de Chagas / Medicinal plants in the treatment of Chagas disease

La enfermedad de Chagas, por su magnitud, gravedad, trascendencia y vulnerabilidad es considerada como un problema en Salud Pública. El área endémica en Bolivia abarca 6 de los 9 departamentos con una aproximación del 60% del territorio, zonas geográficas comprendidas entre los 300 a 3.500 m.s.n.m, ocupando casi toda la superficie de los departamentos de: Tarija, Chuquisaca, Cochabamba, Santa Cruz y parcialmente Potosí y La Paz; con una población en riesgo de 3.700.000 habitantes, de las que 1.800.000 de bolivianos estarían infectados según el estudio del Dr. Angel Valencia para el año 1992, resultando una seroprevalencia del 40% para la población total del país, en otras regiones alcanzando hasta el 70% de infectados. La enfermedad de Chagas se transmite a través de vectores o triatominos, que representa más del 80% de todos los casos, en menor porcentaje la transmisión congénita (10 %) y por transfusión no controlada (5 %). Se ha encontrado que el promedio de vinchucas infectadas con el parásito Trypanosoma cruzi y es de 30%, alcanzando en algunas áreas hasta el 90% de positividad. Pese a los esfuerzos del Programa Nacional de Control del Chagas en Bolivia tenemos pocos avances medidos por el número de tratamientos realizados, reducción de zonas endémicas e intervenciones en la misma comunidad. Déficit en la disponibilidad de medicamentos a nivel internacional con efectos importantes en el nivel local por la imposibilidad de acceder por sus costos elevados que la población de pocos recursos económicos no puede acceder. Uno de los factores identificados es el comportamiento de la población ligada a sus costumbres y tradiciones, persiste una actitud de rechazo o al menos resistencia a cambios sustantivos, por otra parte, el Programa Nacional de Control del Chagas no ha logrado introducir aspectos vinculados a la interculturalidad como ser los tratamientos que históricamente han estado realizando. Se observa también migración campo-ciudad, influye para la transmisión por los asentamientos peri ­ urbanos y viviendas precarias que hacen un hábitat favorable para la infestación de las vinchucas. Finalmente, no hay estudios en el ámbito local de estas ventajas conocidas y aceptadas en el entorno de las comunidades especialmente indígenas y campesinas. Sin embargo experiencias foráneas están demostrando su efectividad en el tratamiento. El objetivo de esta investigación es Identificar el uso de las plantas medicinales en la terapéutica de la enfermedad de Chagas logrando este objetivo mediante el conocimiento de las plantas medicinales en la terapéutica de la enfermedad de Chagas con base a experiencias previas, determinar plantas medicinales de mayor efectividad como terapéutica en la enfermedad de Chagas con base a experiencias conocidas, todo en base a una exhaustiva revisión bibliográfica. Con base a los resultados proponemos un plan de intervención aplicable a nivel de la comunidad local. El método propuesto es una revisión bibliográfica en el marco de un estudio de tipo monográfico, en consecuencia el estudio no amerita encuestas o entrevistas personales de ningún tipo. En resumen, es un estudio Monográfico con base en la revisión exhaustiva de las experiencias en el control de la enfermedad de Chagas, revisión bibliográfica de las publicaciones a la fecha a nivel nacional e internacional. Los resultados más importantes es un vademécum base para el tratamiento de la enfermedad de Chagas con base a la revisión bibliográfica, existe acuerdo a los estudios de plantas medicinales que actúan sobre el parásito Trypanosoma cruzi en todas sus formas. Son insuficientes los estudios que constate el principio activo de la planta y la debilidad más importante es la dispersión de los estudios sobre plantas medicinales. (AU)

Productos naturales con actividad leishmanicida y tripanocida / Natural products with leishmanicidal and trypanocidal activity

Las enfermedades parasitarias constituyen un importante problema de salud, y muchas de ellas están emergiendo en países donde se consideraban erradicadas. La leishmaniasis, la enfermedad del sueño y la enfermedad de Chagas, causadas por los parásitos Leishmania spp, Trypanosoma brucei y Trypanosoma cruzi, respectivamente, se encuentran entre las enfermedades parasitarias más prevalentes. La principal alternativa para tratarlas es la quimioterapia. Sin embargo, los tratamientos actuales se encuentran lejos de ser satisfactorios. La toxicidad de los fármacos, la vía de administración, la duración de los tratamientos y la aparición de resistencias hacen necesario el desarrollo de nuevas moléculas activas, más seguras y eficaces. Estudios recientes ponen de manifiesto la actividad leishmanicida y tripanocida in vivo de una amplia variedad de compuestos fenólicos, alcaloides y terpenos. En este artículo se revisan los productos naturales activos frente a leishmaniasis, enfermedad del sueño y enfermedad de Chagas (AU)

Diseases caused by protozoan parasites are still an important human health problem, since many of them are becoming “emerging” infectious sickness in geographical areas where they were considered eradicated. Leishmaniasis, African sleeping sickness and Chagas disease, caused by the parasites Leishmania spp, Trypanosoma brucei and Trypanosoma cruzi, respectively, are among the most important parasitic diseases. The main alternative to control such parasitosis is chemotherapy. Nevertheless, the current drug treatments are far from being satisfactory. Toxic side effects, route of administration, long-term treatments and the apparition of resistance, highlight the urgent need of developing new active molecules, more safe and effective. Recent studies report the leishmanicidal and trypanocidal activities of a wide variety of phenolic compounds, alkaloids and terpenes that have shown activity in vivo. This review outlines the current understanding of natural products against leishmaniasis, African sleeping sickness and Chagas disease (AU)

Experimental chemotherapy and approaches to drug discovery for Trypanosoma cruzi infection.

In the 100 years since the discovery of Chagas disease, only two drugs have been developed and introduced into clinical practice, and these drugs were introduced over 40 years ago. The tools of drug discovery have improved dramatically in the interim; however, this has not translated into new drugs for Chagas disease. This has been largely because the main practitioners of drug discovery are pharmaceutical companies who are not financially motivated to invest in Chagas disease and other "orphan" diseases. As a result, it has largely been up to academic groups to bring drug candidates through the discovery pipeline and to clinical trials. The difficulty with drug discovery in academia has been the challenge of bringing together the diverse expertise in biology, chemistry, and pharmacology in concerted efforts towards a common goal of developing therapeutics. Funding is often inadequate, but lack of coordination amongst academic investigators with different expertise has also contributed to the slow progress. The purpose of this chapter is to provide an overview of approaches that can be accomplished in academic settings for preclinical drug discovery for Chagas disease. The chapter addresses methods of drug screening against Trypanosoma cruzi cultures and in animal models and includes general topics on compound selection, testing for drug-like properties (including oral bioavailability), investigating the pharmacokinetics and toxicity of compounds, and finally providing parameters to help with triaging compounds.

Perfil clínico-epidemiológico de chagásicos atendidos em ambulatório de referência e proposiçäo de modelo de atençäo ao chagásico na perspectiva do sus / Clinical and epidemiological profile of Chagas' disease patients attended in out-patient ward reference center and proposal of a case model to the Chaga's disease patient in the State Health Plan

A case-control study to analyse clinical and epidemiological data of 842 patientes seen in an outpatient ward reference center for chagas disease in Belo Horizonte, Brazil, from 1985 to 1992. It was verified that these patients were in a average age of 37.78 years; lower literacy regardless of race, and, performed activities that demanded greater muscle effort (p < 0.05). The main mechanism for disease transmission proved to be the vectorial route. Disease-especific complaints prevailed in the above mentioned patients (p < 0.05). The most important abnormalities found in clinical examination were with cardiac sounds (OR: 2.96 95 per cent CI: 1.29-4.09) and the presence of extrasystole (OR: 7.16 95 per cent CI: 1.59-45.07). Imunofluorescence Test was more sensitive (94 per cent) and specific (96 per cent). It also had a PPV of 99 per cent and e NPV of 83 per cent. ELISA test carried out in 43 patientes did not yield false results. Indeterminate chronic phase (56 per cent) or early stages of the disease prevailed. The findings of normal EKGs and abnormalities in 30 per cent of the Holter tests, 41 per cent of the exercise tests, 33 per cent of the ECO tests and, 48 per cent of normal chest x-ray with abnormal ECO, high lights the importance of caring out more detailed exams in specific situations. We hereby propose a care model for the Chagas disease patient, integrated to our State Health Plan stressing serologic tests, and training capable human resources committed to the development of integrated health care and the optimization of our referral and counter-referral system, thus issuing total care to the Chagas disease patient.

[Clinico-epidemiologic profile of Chagas disease patients attending an ambulatory referral center and proposal of a model of care for the Chagas patient under the perspective of a comprehensive health care]. / Perfil clínico-epidemiológico de chagásicos atendidos em ambulatório de referência e proposição de modelo de atenção ao chagásico na perspectiva do sus.

A case-control study to analyse clinical and epidemiological data of 842 patientes seen in an outpatient ward reference center for chagas disease in Belo Horizonte, Brazil, from 1985 to 1992. It was verified that these patients were in a average age of 37.78 years; lower literacy regardless of race, and, performed activities that demanded greater muscle effort (p < 0.05). The main mechanism for disease transmission proved to be the vectorial route. Disease-especific complaints prevailed in the above mentioned patients (p < 0.05). The most important abnormalities found in clinical examination were with cardiac sounds (OR: 2.96 95% CI: 1.29-4.09) and the presence of extrasystole (OR: 7.16 95% CI: 1.59-45.07). Imunofluorescence Test was more sensitive (94%) and specific (96%). It also had a PPV of 99% and e NPV of 83%. ELISA test carried out in 43 patientes did not yield false results. Indeterminate chronic phase (56%) or early stages of the disease prevailed. The findings of normal EKGs and abnormalities in 30% of the Holter tests, 41% of the exercise tests, 33% of the ECO tests and, 48% of normal chest x-ray with abnormal ECO, high lights the importance of caring out more detailed exams in specific situations. We hereby propose a care model for the Chagas disease patient, integrated to our State Health Plan stressing serologic tests, and training capable human resources committed to the development of integrated health care and the optimization of our referral and counter-referral system, thus issuing total care to the Chagas disease patient.

Treatment of T. cruzi infected human platelet concentrates with aminomethyltrimethyl psoralen (AMT) and ultraviolet A (UV-A) light: preliminary results

The present measures adopted to prevent transfusion-associated Chagas' disease include screening of blood donors, and/or the inactivation of T. cruzi in collected blood using gentian violet (GV), as a trypanocidal agent. In this study, we investigated the efficacy of the combined use of AMT and UV-A in inactivating T. cruzi in infected human platelet concentrates. Human platelet concentrates were infected with T. cruzi (2 x 10(8)/ml) of the Y strain, transfered to PL 269 (Fenwal Laboratories) containers, and treated with GV (250 micrograms/ml), and ascorbic acid (1 mg/ml); GV, ascorbic acid and UV-A; GV and UV-A; AMT (40 microG/ml) and ascorbic acid; AMT, ascorbic acid and UV-A; AMT and UV-A; UV-A alone; and untreated (control). All UV-A treated platelet concentrates were exposed to UV-A doses of 24, 92, 184, 276, 368 and 644 kJ/m2, and the microscopical research of active T. cruzi was performed, using the microhematocrit technique, 1, 6 and 24 hours after each treatment. A high number of active forms of T. cruzi was observed in all condictions, except when GV was used as the trypanocidal agent, providing evidence of the failure of AMT and UV-A in inactivating T. cruzi in infected human platelet concentrates.

Treatment of T. cruzi infected human platelet concentrates with aminomethyltrimethyl psoralen (AMT) and ultraviolet A (UV-A) light: preliminary results.

The present measures adopted to prevent transfusion-associated Chagas' disease include screening of blood donors, and/or the inactivation of T. cruzi in collected blood using gentian violet (GV), as a trypanocidal agent. In this study, we investigated the efficacy of the combined use of AMT and UV-A in inactivating T. cruzi in infected human platelet concentrates. Human platelet concentrates were infected with T. cruzi (2 x 10(8)/ml) of the Y strain, transfered to PL 269 (Fenwal Laboratories) containers, and treated with GV (250 micrograms/ml), and ascorbic acid (1 mg/ml); GV, ascorbic acid and UV-A; GV and UV-A; AMT (40 microG/ml) and ascorbic acid; AMT, ascorbic acid and UV-A; AMT and UV-A; UV-A alone; and untreated (control). All UV-A treated platelet concentrates were exposed to UV-A doses of 24, 92, 184, 276, 368 and 644 kJ/m2, and the microscopical research of active T. cruzi was performed, using the microhematocrit technique, 1, 6 and 24 hours after each treatment. A high number of active forms of T. cruzi was observed in all condictions, except when GV was used as the trypanocidal agent, providing evidence of the failure of AMT and UV-A in inactivating T. cruzi in infected human platelet concentrates.

Quimioprofilaxia da doença de Chagas experimental: avaliaçäo da atividade de Zanthoxylum minutiflorum Tul / Experimental Chagas' disease chemoprofilaxy. Activities of crude extracts and fractions of Zanthoxylum minutiflorum Tul

A doença de Chagas é endêmica no continente americano e afeta milhöes de habitantes. O seu agente causal, Trypanosoma cruzi, encontrado no sangue de mais de uma centena de espécies de mamíferos, é transmitido ao homem por aproximadamente cem espécies de triatomíneos. Atualmente, em regiöes de grande incidência, nas quais näo säo realizadas seleçöes de doadores de sangue é cada vez maior a imprtância da transmissäo transfuncional desta doença. Este problema poderia ser solucionado pelo uso de uma droga tripanossomicida, atóxica para homem q que, adicionada ao sangue vai ser transfundido, eliminasse os parasitas presentes. Levando-se em conta a importância da transmissäo transfunsional, as dificuldades na seleçäo de doadores e a inexistência de um produto eficaz e seguro contra o tripanossoma, empreendemos um estudo visando encontrar em Zanthoxylum minutiflorum Tul. (Rutaceae), uma droga que, adicionada ao sangue a ser transfundido, fosse atóxica para animais de laboratório e prevenisse a transmissäo da doença de Chagas experimental. Para tanto, primeiramente,realizamos o estudo farmacognóstico que nos deu condiçöes de caracterizar e analisar esta nova droga vegetal. A seguir, os extratos, fraçöes e substâncias obtidas de Z. minutiflorum foram espectrofotometriacamente analisadas para determinaçäo de seus perfis químicos e estruturais. Estas análises comprovaram os resultados dos ensaios prévios do estudo farmacognóstico e nos permitiram sugerir que os compostos isolados do Extrato Hexânico eram: um triterpenóide pentacíclico livre - Lupeol, uma mistura de substâncias com núcleo esteroidal-Beta-Sitostero/Estigmasterol e um alcalóide ou amida. Continuando o estudo, produtos obtidos de Zanthoxylum minutiflorum foram submetidos a ensaio biológicos e demonstramos que vários deles desenvolveram potente açäo contra cepas Bolívia de T. cruzi, in vitro. Finalmente, determinamos que o Extrato Alcoólico de caules de Z. minutiflorum, nas concentraçöes de 25 e 50 mg/ml de sangue, possui potente açäo tripanossomicida, baixa toxicidade ppara hemácias e alta DL50 e pode ser útil no controle da transmissöo transfusional da doença de Chagas experimental

Sinergismo en la acción antiproliferativa de inhibidores de la sintesis de esteroles sobre el trypanosoma cruzi in vitro e in vivo implicaciones terapéuticas / Sinergistic in the antiproliferative action of sterol synthesis inhibitors on in vitro and in vivo thypanosoma cruzi: therapeutic aspects

Los estudios realizados desde el punto de vista molecular, celular y organismico revelan que el Trypanosoma cruzi en su proliferación depende de la producción de esteroles endógenos. Cualquier intervención farmacológica que modifique esta ruta biosintética previene la proliferación del parásito, in vivo e in vitro. Además cuando se combinan estos agentes, ellos pueden tener acción sinergética sobre la proliferación del parásito, lo que permite pensar, que podría ser útil en el tratamiento de la Enfermedad de Chagas, sin efectos secundarios. Las combinaciones hasta ahora conocidas son el ketoconazol (Janssen) Lamisil (Sandoz) y el ketoconazol-Mevacor (Merk Sharp & Dohme). Otras combinaciones han sido evaluadas por nuestro grupo y la OMS, como el itraconazol (Janssen) que posee mayor actividad y menor toxicidad que el anterior, usándolo en combinación con la sinvastatina (Merk Sharp & Dohne) y la fluvastatina (Sandoz). Finalmente, las terapéuticas propuestas pueden ser útiles en el tratamiento de otras enfermedades parasitarias y algunas micosis sistémicas

Avaliacao da atividade terapeutica do fluconazol na infeccao aguda, experimental pelo Trypanosoma cruzi / Evaluation of therapeutic activity of fluconazole in acute experimental infection by Trypanosoma cruzi

En virtude de informacoes de que o fluconazol pode coibir a infeccao devida ao Trypanosoma cruzi, efetuamos investigacao experimental a respeito, utilizando camundongos agudamente infectados e esquema terapeutico baseado na administracao de 200 mg/kg/dia da referida droga, durante um mes. Parasitemia, hemocultura, subinoculacao e exame histologico serviram como parametros para avaliar a eventual atividade curativa do medicamento em questao. Os resultados obtidos nao confirmaram a propriedade aventada, mas e conveniente estimular novos estudos sobre o assunto, envolvendo o imidazoico que usamos, alem de outros.

Estudo comparativo dos indices de cura de camundongos tratados com quimioterapicos e trypanosominum (TC D 30) / Comparative analysis of the cure rate in mices treated with chemoterapics and trypanosominum (TC D 30)

Trypanosoma cruzi strain isolated from wild mamals or from man and studied in the laboratory show different characteristics that permit their individualization. Blood trypamastigotes exhibit different morphological patterns according to the strain studied. Tropism for different tissues has also been reported. Morphologically, there are wide, thin and intermediate forms wose proportions vary. The results obtained by different investigations in the treatment of Chagas disease are discrepant in different geographic areas, probably because of a relationship with different populations of T.cruzi. In the presentestudy, we investigated experimentally the susceptibility of two polar species, i.e. two species with predominance of thin and wide forms, respectively (Y e Bolivia strains) to the action of Nifurtimax, Benzonidazol and Trypanosaminum (TC D30). Groups of 30 mice aged 60 days were inoculated with 10.4 bloodstream forms of the Y and Bolivia strains of T.cruzi. On the third day of infection, the animals were treated with 100 mg/Kg of both chemotherapeutic agents and with 5 dropsof Trypanosaminum (TC D 30) orally for 20 days. Each animal was evaluated for parasitemia and behavior. Xenodiagnosis and blood cultures were carried out after 40 days. The results showed: a) a sharp resistance of the Bolivia strain to the chemotherapeutic agents, while the Y strain was more susceptible; b) identical susceptibility of the Y and Bolivia strains to treatment with Trypanosominum. We infer from these data that the chemotherapeutic agents act on the parasitic formsby destroying them or not, with sharp differences when different populations areinvolved. In contrast, Trypanosaminum (TC D 30) may act on the stimulating the imunologic response, wich may destroy the etiologic agents through a specific response mechanism, regardless of the characteristics of the strain studied

Ensaios clinicos com o bioterapico "Tripanossoma-cruzi" D30 nas formas cronicas e sintomaticas da "Doenca de Chagas" / Biotherapic trypanosoma cruzi D30 clinical essays in chronical forms of the Disease of Chagas

The auctor presents clinical essays putting out in evidence the action of the biotherapic T.cruzi D30 by chronical forms of the diseaseof Chagas. The initial forms present answers more satisfactoires. Future studieswill must include the utilization of named Similimum