Resumen (Objetivo) Tryapanosoma cruzi, un agente causal de la enfermedad de Chagas, es un parásito que presenta una alternancia en su ciclo de vida entre un hospedador invertebrado (triatomino) y uno vertebrado (mamífero). Varios estudios han demostrado que en T. cruzi, HSP83 (homólogo de HSP90) es esencial para la división celular y el control de la respuesta al estrés térmico. Esta investigación se concentró en el estudio de la clonación, la caracterización bioinformática y la expresión del gen de la proteína de choque térmico HSP83 de T. cruzi para estudios posteriores sobre señalización. (Metodología) El ARN fue extraído de epimagostigotes T. cruci (clon EPm6/MOHM/VE/2007/ 6c), utilizando un kit comercial. El ADNc que codifica HSP83 se obtuvo utilizando RT-PCR, a partir del ARNm extraído, para lo cual se diseñaron los cebadores con base en la secuencia HSP83 de la cepa T. cruzi CL Brener. La clonación se realizó usando pGEM®T-Easy y se subclonó en el vector de expresión pQE30. Se efectuó la caracterización bioinformática y de secuencias. El gen se expresó y la proteína recombinante se purificó por cromatografía de afinidad, igual que se identificó por inmunotransferencia. (Resultados) El análisis de secuencia mostró similitud con el gen HSP83 de Trypanosoma cruzi y se observaron dominios HSP, así como epítopos B en la secuencia. Después de 3 horas de inducción con IPTG, se obtuvo una proteína recombinante con un peso aproximado de 83 kDa. La reacción de inmunotransferencia con suero hiperinmune anti-epimastigote de T. cruzi permitió la detección de una sola banda con un peso molecular de aproximadamente 83 kDa. (Conclusiones) Todos los resultados indican que se logró la clonación y caracterización de HSP83 de Trypanosoma cruzi.

Resumo (Objetivo) O Tryapanosoma cruzi, agente causador da doença de Chagas, é um parasita que apresenta uma alternância em seu ciclo de vida entre um hospedeiro invertebrado triatomíneo) e um vertebrado(mamífero). Vários estudos demonstraram que, no T. cruzi, a HSP83 (homóloga da HSP90) é essencial para a divisão celular e o controle da resposta ao estresse térmico. Esta pesquisa concentrou-se no estudo da clonagem, caracterização bioinformática e expressão do gene da proteína de choque térmico HSP83 do T. cruzi para estudos adicionais de sinalização. (Metodologia) O RNA foi extraído de epimastigotas de T. cruzi (clone EPm6/MOHM/VE/2007/ 6c) usando um kit comercial. O cDNA que codifica a HSP83 foi obtido por meio de RT-PCR a partir do mRNA extraído, para o qual os primers foram projetados com base na sequência da HSP83 da cepa T. cruzi CL Brener. A clonagem foi realizada com o pGEM®T-Easy e subclonada no vetor de expressão pQE30. Foi realizada a caracterização bioinformática e de sequência. O gene foi expresso e a proteína recombinante foi purificada por cromatografia de afinidade e identificada por imunotransferência. (Resultados) A análise da sequência mostrou similaridade com o gene HSP83 do Trypanosoma cruzi e os domínios HSP, bem como os epítopos B, foram observados na sequência. Após 3 horas de indução com IPTG, foi obtida uma proteína recombinante com peso aproximado de 83 kDa. A imunotransferência com soro hiperimune antiepimastigota de T. cruzi permitiu a detecção de uma única banda com peso molecular de aproximadamente 83 kDa. (Conclusões) Todos os resultados indicam que a clonagem e a caracterização da HSP83 do Trypanosoma cruzi foram alcançadas.

Abstract (Objective) Trypanosoma cruzi, a causal agent of Chagas’ disease, is a parasite whose life cycle alternates between an invertebrate (triatomine) and a vertebrate (mammal) host. Various studies have shown that in T. cruzi, HSP83 (a homolog of HSP90) is essential for cell division and control of the response to thermal stress. This investigation focused on studying the cloning, bioinformatic characterization, and expression of the heat shock protein HSP83 T. cruzi gene for further cell signaling studies. (Methodology) RNA was extracted from T. cruzi epimastigotes (EPm6 clone, MHOM/VE/2007/ 6c) using a commercial kit. The cDNA encoding HSP83 was determined using RT-PCR on extracted mRNA, for which the primers were designed based on the HSP83 sequence of T. cruzi strain CL Brener. Cloning was performed using pGEM®T-Easy and subcloned into the expression vector pQE30. Sequence and bioinformatic characterization were performed. The gene was expressed, and the recombinant protein was purified using affinity chromatography and identified through immunoblotting. (Results) Sequence analysis showed similarity to the gene encoding HSP83 from Trypanosoma cruzi, and HSP domains and B epitopes in the sequence were also observed. After 3 hours of induction with IPTG, a recombinant protein with an approximate weight of 83 kDa was obtained. The immunoblotting reaction with hyperimmune anti-T. cruzi epimastigote serum helped detect a single band with a molecular weight of nearly 83 kDa. (Conclusions) All results indicate that the cloning and characterization of HSP83 from Trypanosoma cruzi was achieved.

Abstract Introduction: Chagas disease is caused by a hemoflagellate parasite called Trypanosoma cruzi, distributed mainly in Latin America. Countries like Mexico are affected by this parasite, and it is estimated that one million people carry the disease. Currently, the treatment focuses on benznidazole and nifurtimox, which, when applied in the acute phase, is effective but not in the chronic phase and is difficult to access. Therefore, alternatives that can provide new treatments are sought; one option is plants, since they produce secondary metabolites with various biological activities, including antiparasitic. Objective: To evaluate the trypanocidal potential of methanolic extracts collected in some Mexican states from various Latin American plants. Methods: The five plant species under study were obtained in Mexico from the states of Jalisco, Aguascalientes, and Nuevo León; the samples were dried, and the methanolic extracts were obtained. Two strains of T. cruzi were used to evaluate its trypanocidal activity; the Ninoa strain and a wild strain obtained in Calvillo, Aguascalientes. Concentrations of the extracts from 1 000 to 10 ppm were evaluated using a microdilution method. Results: The extracts showed an inhibitory concentration between 1 418.74 ± 6 ppm and 14.1 ± 5 ppm; the extract that presented the best activity was the Arctostaphylos pungens (pinguica) leaf. Conclusions: A. pungens is a plant used in traditional Mexican medicine, and this study has shown that it is a source of compounds against T. cruzi. Future studies could determine its toxicity and cytotoxicity to be applied as a possible treatment for Chagas disease.

Resumen Introducción: La enfermedad de Chagas es causada por un parásito hemoflagelado llamado Trypanosoma cruzi, distribuido principalmente en América Latina. Países como México se ven afectados por este parásito, y se estima que un millón de personas padecen la enfermedad. Actualmente, el tratamiento se centra en el benznidazol y el nifurtimox, que, cuando se aplican en la fase aguda, son efectivos, pero no en la fase crónica y son de difícil acceso. Por lo tanto, se buscan alternativas que puedan proporcionar nuevos tratamientos; una opción son las plantas, ya que producen metabolitos secundarios con diversas actividades biológicas, incluida la actividad antiparasitaria. Objetivo: Evaluar el potencial tripanocida de extractos metanólicos recolectados en algunos estados mexicanos de diversas plantas latinoamericanas. Métodos: Las cinco especies de plantas estudiadas fueron obtenidas en México de los estados de Jalisco, Aguascalientes y Nuevo León; las muestras fueron secadas y se obtuvieron los extractos metanólicos. Se utilizaron dos cepas de T. cruzi para evaluar su actividad tripanocida; la cepa Ninoa y una cepa silvestre obtenida en Calvillo, Aguascalientes. Se evaluaron las concentraciones de los extractos de 1 000 a 10 ppm utilizando un método de microdilución. Resultados: Los extractos mostraron una concentración inhibitoria entre 1 418.74 ± 6 ppm y 14.1 ± 5 ppm; el extracto que presentó la mejor actividad fue la hoja de Arctostaphylos pungens (pinguica). Conclusiones: A. pungens es una planta utilizada en la medicina tradicional mexicana, y este estudio ha demostrado que es una fuente de compuestos contra T. cruzi. Estudios futuros podrían determinar su toxicidad y citotoxicidad para ser aplicados como un posible tratamiento para la enfermedad de Chagas.

Resumo Fundamento: A Cardiomiopatia Chagásica Crônica (CCC) é causada por um processo inflamatório induzido pelo Trypanosoma cruzi, que leva à miocardite com fibrose reativa e reparativa. A CCC progride com alterações de perfusão miocárdica e eventos histopatológicos que afetam a Aptidão Cardiorrespiratória (ACR). Objetivos: Avaliamos os efeitos do Treinamento Físico Aeróbico (TFA) na perfusão miocárdica e nos comprometimentos morfológicos e funcionais relacionados à inflamação e fibrose em hamsters sírios com CCC. Como objetivo secundário, analisamos as áreas de secção transversa do músculo esquelético. Métodos: Hamsters com CCC e seus respectivos controles foram divididos em quatro grupos: CCC sedentário, CCC-TFA, controle sedentário e controle TFA. Sete meses após a infecção, os animais foram submetidos à ecocardiografia, à cintilografia de perfusão miocárdica e ao teste de esforço cardiopulmonar. TFA de intensidade moderada foi realizado durante cinquenta minutos, cinco vezes por semana, por oito semanas. Posteriormente, os animais foram reavaliados. A análise histopatológica foi realizada após os procedimentos acima mencionados. O nível de significância foi estabelecido em 5% em todas as análises (p<0,05). Resultados: Animais com CCC sedentários apresentaram piores Defeitos de Perfusão Miocárdica (DPM) ao longo do tempo, Fração de Ejeção do Ventrículo Esquerdo (FEVE) reduzida, e apresentaram mais inflamação e fibrose quando comparados aos demais grupos (análise ANOVA mista). Por outro lado, o TFA foi capaz de mitigar a progressão do DPM, atenuar a inflamação e a fibrose e melhorar a eficiência da ACR em animais CCC-TFA. Conclusão: Nosso estudo demonstrou que o TFA melhorou a disfunção cardíaca, DPM e reduziu a inflamação e a fibrose em modelos de hamster com CCC. Além disso, os animais CCC-SED apresentaram atrofia do músculo esquelético, enquanto os animais CCC-TFA apresentaram a AST do músculo esquelético preservada. Compreender os efeitos da TFA nas dimensões fisiopatológicas da CCC é crucial para futuras pesquisas e intervenções terapêuticas. Fundamento (CCC cruzi reparativa ACR. . (ACR) Objetivos (TFA secundário Métodos CCCTFA, CCCTFA TFA, infecção ecocardiografia cardiopulmonar minutos semana semanas Posteriormente reavaliados mencionados 5 p<0,05. p005 p p<0,05 0 05 (p<0,05) Resultados (DPM tempo FEVE (FEVE reduzida mista. mista mista) lado CCCTFA. Conclusão cardíaca disso CCCSED SED preservada terapêuticas (ACR p00 p<0,0 (p<0,05 p0 p<0, (p<0,0 p<0 (p<0, p< (p<0 (p< (p

Abstract Background: Chronic Chagas cardiomyopathy (CCC) is caused by an inflammatory process induced by Trypanosoma cruzi, which leads to myocarditis with reactive and reparative fibrosis. CCC progresses with myocardial perfusion abnormalities and histopathological events that affect cardiorespiratory fitness (CRF). Objectives: We evaluated the effects of aerobic physical training (APT) on myocardial perfusion and on morphological and functional impairments related with inflammation and fibrosis in Syrian hamsters with CCC. As a secondary objective, we analyzed the cross-sectional areas of the skeletal muscle. Methods: Hamsters with CCC and their respective controls were divided into four groups: CCC sedentary, CCC-APT, sedentary control and APT control. Seven months after infection, the animals underwent echocardiography, myocardial perfusion scintigraphy and cardiopulmonary exercise testing. Moderate-intensity APT was performed for fifty minutes, five times a week, for eight weeks. Subsequently, the animals were reassessed. Histopathological analysis was conducted after the above-mentioned procedures. The level of significance was set at 5% in all analyses (p<0.05). Results: CCC sedentary animals presented worse myocardial perfusion defects (MPD) over time, reduced left ventricle ejection fraction (LVEF) and showed more inflammation and fibrosis when compared to other groups (mixed ANOVA analysis). Conversely, APT was able to mitigate the progression of MPD, ameliorate inflammation and fibrosis and improve CRF efficiency in CCC-APT animals. Conclusions: Our study demonstrated that APT ameliorated cardiac dysfunction, MPD, and reduced inflammation and fibrosis in CCC hamster models. Additionally, CCC-SED animals presented skeletal muscle atrophy while CCC-APT animals showed preserved skeletal muscle CSA. Understanding APT's effects on CCC's pathophysiological dimensions is crucial for future research and therapeutic interventions. Background (CCC cruzi CRF. . (CRF) Objectives (APT objective crosssectional cross sectional Methods CCCAPT, CCCAPT APT, infection echocardiography testing Moderateintensity Moderate intensity minutes week weeks Subsequently reassessed abovementioned above mentioned procedures 5 p<0.05. p005 p p<0.05 0 05 (p<0.05) Results MPD (MPD time LVEF (LVEF mixed analysis. analysis) Conversely Conclusions dysfunction models Additionally CCCSED SED CSA APTs s CCCs interventions (CRF p00 p<0.0 (p<0.05 p0 p<0. (p<0.0 p<0 (p<0. p< (p<0 (p< (p

Abstract Objective: Analyze sex hormone's influence during Chagas disease. Methods: Male and female BALB/c mice were divided into six groups, four experimental (sham, orchiectomized, orchiectomized and supplemented with estradiol, orchiectomized supplemented with testosterone, oophorectomized, oophorectomized and supplemented with estradiol, and oophorectomized and supplemented with testosterone), and two control (healthy and intraperitoneally with T. cruzi strain NINOA infected). Clinical data were recorded daily, parasitemia was evaluated using a Neubauer chamber during the infection, and heart histopathological analysis was performed using the paraffin embedding technique. To analyze parasitemia curves and the area under the parametric curves, two-way ANOVA test was performed to correlate groups' data. P-values < 0.05 were considered statistically significant. Results: Higher mortality rates, cardiomegaly, hepatomegaly, ascites, edema, higher parasitemia levels, more amastigote nests, and more severe inflammatory infiltrate were found in higher testosterone concentration mice, whereas in higher estradiol concentration groups, paresia, prostration, edema, and necrosis were found. Conclusions: Our results showed that testosterone increased infection severity, whereas estradiol had the opposite effect. This research improves the understanding of sex hormones´ infuence upon this infection to contribute with the handling of Chagas´ disease.

Resumen Objetivo: Analizar la influencia de las hormonas durante la enfermedad de Chagas. Métodos: Se separaron grupos de ratones macho y hembras BALB/c, todos infectados con T. cruzi (cepa NINOA), 4 grupos experimentales de machos (Sham, orquidectamizados, orquidectimezados y suplementados con estradiol, orquidectamizaos y suplementados con testosterona). 4 grupos experimentales de hembras (oforectomizadas, oforectomizadas y suplementadas con estradiol, oforectomizadas y suplementadas con testosterona y sham), and y dos grupos control para cada sexo (sin infección e infectados intraperitonealmente con T. cruzi (cepa NINOA). Los datos clínicos fueron registrados diariamente, la parasitemia fue evaluada durante toda la infección utilizando una cámara de Neubauer y el análisis histopatológico del corazón fue realizada con la técnica de inclusión en parafina. Para el análisis de las curvas de parasitemia y el área bajo la curva, se realizó una prueba de ANOVA de dos vías, p < 0.05 fueron considerados estadísticamente diferentes. Resultados: Las mayores tasas de mortalidad, cardiomegalia, hepatomegalia y mayor infiltrado inflamatorio, se encontró en los ratones con una mayor concentración de testosterona. En contraste los ratones con mayor concentración de estradiol presentaron paresia, postración edema y necrosis. Conclusiones: Nuestros resultados ponen en manifiesto que la testosterona incrementa la severidad del curso de la enfermedad de Chagas, mientras que el estradiol tuvo el efecto opuesto. Este trabajo mejora el entendimiento del rol que juegan las hormonas sexuales en esta infección para contribuir en un mejor manejo de la enfermedad de Chagas.

Resumen La Enfermedad de Chagas (EC) es endémica en el Ecuador, con una notable prevalencia en la provincia de Manabí. Específicamente, el cantón Olmedo destaca como uno de los más afectados por esta enfermedad. El objetivo del presente estudio es caracterizar clínica y epidemiológicamente los casos de EC, diagnosticados desde enero 2019 a diciembre 2022 en el Cantón Olmedo, Manabí, Ecuador. Se realizó un estudio observacional, descriptivo, de registro de 14 casos confirmados por infección de Trypanosoma cruzi. Las variables estudiadas fueron, el número de casos presentados por año, sexo, grupos de edades, diagnóstico de laboratorio, tipo de vigilancia. Se identificaron un total 14 casos reactivo; mayormente representada por el sexo masculino; con predominio de personas mayores de 65 años. La vigilancia activa contribuyó al mayor número de notificaciones. El total de casos correspondieron a Chagas crónicos. Las comunidades San Roque y el barrio Divino Niño, presentaron el mayor número de notificaciones de casos confirmados. En conclusión, se plantea que la Enfermedad de Chagas representa un problema de salud silente en el Cantón Olmedo. La vigilancia activa a través de búsqueda de casos, así como los test de anticuerpos son claves en el diagnóstico.

Abstract Chagas Disease (CD) is endemic in Ecuador, with a notable prevalence in the province of Manabí. Specifically, the Olmedo canton stands out as one of the most affected by this disease. The objective of the present study is to clinically and epidemiologically characterize the cases of CD, diagnosed from January 2019 to December 2022 in the Olmedo Canton, Manabí, Ecuador. An observational, descriptive study was carried out, registering 14 confirmed cases of Trypanosoma cruzi infection. The variables studied were the number of cases presented per year, sex, age groups, laboratory diagnosis, type of surveillance. A total of 14 reactive cases were identified; mostly represented by the male sex; with a predominance of people over 65 years of age. Active surveillance contributed to the highest number of notifications. The total number of cases corresponded to chronic Chagas disease. The communities of San Roque and the Divino Niño neighborhood presented the highest number of notifications of confirmed cases. In conclusion, it is proposed that Chagas Disease represents a silent health problem in the Olmedo Canton. Active surveillance through case search, as well as antibody tests, are key in diagnosis.

Resumo A reativação da doença de Chagas crônica é condição rara e ocorre apenas em pacientes imunossuprimidos. O envolvimento da pele foi reportado em pacientes com doença de Chagas crônica e transplante hepático e cardíaco com reativação da tripanossomíase. Em todos os casos cutâneos foi detectada a forma amastigota do Trypanosoma cruzi. Nosso caso traz paciente feminina de 51 anos com história de transplante cardíaco devido à doença de Chagas e imunodepressão. A equipe dermatológica foi chamada devido ao aparecimento de nódulos eritematosos dolorosos, após 30 dias de hospitalização. Primeiramente, a biópsia de pele foi compatível com hipótese de leishmaniose cutânea. Depois da imuno-histoquímica, confirmou-se a presença de T. cruzi, sendo decidido tratar reativação da doença de Chagas. O desenvolvimento de paniculite não é usualmente associado à doença de Chagas. Assim, ressalta-se a importância de não excluir tal diagnóstico e refere a necessidade da análise anatomopatológica e imuno-histoquímica para complementação diagnóstica.

Abstract Reactivation of chronic Chagas disease is a rare condition, occurring solely in immunosuppressed patients. Skin involvement has been reported in patients with chronic Chagas disease and heart or kidney transplantation who reactivated the trypanosomiasis. In all cases involving the skin, amastigote forms of Trypanosoma cruzi are detected. Our case focuses on a 51-year-old female with a history of cardiac transplantation due to Chagas disease and immunodepression. The dermatology team was consulted due to the presence of painful erythematous nodules, after 30 days of hospitalization. Initially, a skin biopsy suggested cutaneous leishmaniasis as a hypothesis. However, subsequent immunohistochemistry confirmed the presence of T. cruzi, leading to the decision to treat for Chagas disease reactivation. The development of panniculitis is not commonly associated with Chagas disease. This case underscores the importance of not disregarding such possibilities and highlights the necessity for histopathological and immunohistochemical analyses to complement the diagnostic process.

Abstract Introduction. In 2021, the Secretaría de Salud de México and the Pan American Health Organization launched an initiative to interrupt intra-domiciliary vector transmission of Trypanosoma cruzi based on the prevalence of Chagas disease in children. The Mexican State of Veracruz was leading this initiative. Objective. To estimate the seroprevalence of T. cruzi infection among children under 15 years of age from rural areas of Veracruz, México. Materials and methods. We identified eight localities of high priority from the Municipality of Tempoal, Veracruz, for baseline serology. Blood samples were collected on filter paper from 817 individuals between June and August 2017, for screening with a third-generation enzyme immunoassay. Reactive cases were confirmed by indirect hemagglutination, enzyme-linked immunosorbent assay, and indirect immunofluorescence tests on peripheral blood serum samples. We calculated seroprevalence and 95% confidence intervals (CI). Results. We confirmed Chagas disease cases in children under 15 years of age with a seroprevalence of 1,9% (95 % CI = 1,12-3,16) in the localities of Citlaltepetl, Cornizuelo, Cruz de Palma and Rancho Nuevo. Conclusions. These results indicate recent transmission of T. cruzi in these communities and allow to establish an epidemiological baseline for the design and implementation of a model focused on geographical areas with active transmission to advance toward the elimination of intra-domiciliary vector transmission of this parasite in Mexico.

Resumen Introducción. En el 2021, la Secretaría de Salud de México y la Organización Panamericana de la Salud lanzaron una iniciativa para interrumpir la transmisión vectorial intradomiciliaria de Trypanosoma cruzi, fundamentada en la prevalencia de la enfermedad de Chagas en la población infantil. El estado mexicano de Veracruz fue el pionero de esta iniciativa. Objetivo. Estimar la seroprevalencia de infección por T. cruzi en menores de 15 años de localidades rurales de Veracruz, México. Materiales y métodos. Se identificaron ocho localidades prioritarias para la serología basal del municipio de Tempoal, Veracruz. Entre junio y agosto de 2017, se recolectaron muestras de sangre en papel filtro de 817 individuos para su tamizaje mediante un inmunoensayo enzimático de tercera generación. Los casos reactivos del tamizaje se confirmaron mediante pruebas de hemaglutinación indirecta, ensayo de inmunoabsorción ligado a enzimas e inmunofluorescencia indirecta en muestras de suero. Se calculó la seroprevalencia y su intervalo de confianza (IC) del 95 %. Resultados. En las localidades de Citlaltépetl, Cornizuelo, Cruz de Palma y Rancho Nuevo se confirmaron casos de la enfermedad de Chagas en menores de 15 años con una seroprevalencia de 1,9 % (IC 95 % = 1,12-3,16). Conclusiones. Los resultados indican que estas comunidades presentan transmisión reciente de T. cruzi y permiten establecer una línea epidemiológica de base para el diseño e implementación de un modelo dirigido a aquellas áreas geográficas con transmisión activa. Se espera que dicho modelo contribuya a la eliminación de la transmisión vectorial intradomiciliaria del tripanosomátido en México.

ABSTRACT The teaching of human parasitology is essential for students of health sciences, especially medicine, because it is a major global public health problem―occurring with high frequency in low-income countries―and because of its presence in countries considered developed. In this sense, it is estimated that worldwide there are 2,800 million individuals infected with soil-transmitted helminths, 20 to 30% people infected with Toxoplasma gondii, 300 to 500 million new cases of malaria per year, and nearly 15 million Latin Americans with Chagas disease, an infection caused by Trypanosoma cruzi. This narrative review article analyzes information available in digital repositories on aspects of the traditional educational program of human or medical parasitology using descriptors or keywords closely related to the topic. The reviewed articles were mainly those published in peer-reviewed, indexed and prestigious scientific journals. Moreover, the traditional program of parasitology and the prevailing pedagogy are described with the purpose of encouraging discussion on the methods that lead to its learning. Also, given the dynamic nature of this process and the constant challenges that must be faced in this field, said information can help to explore new ways of teaching parasitology in answer to the demands of the context. In conclusion, parasitic diseases have affected humankind throughout history, causing illness, disability and death in millions of people. Therefore, among the measures to fight such a terrible scourge, the training of more and better professionals in the area is promoted due to their leading role in the design and execution of control programs. As a result, the need to describe in detail the characteristics of the traditional teaching of this branch of knowledge arises―as shown in this paper―in view of the new human teaching methods: participatory learning, problem-based learning and Internetassisted learning.

RESUMEN Es fundamental la enseñanza de la parasitología humana para los estudiantes de las carreras de ciencias de la salud, especialmente la médica, por ser un importante problema de salud pública con distribución mundial, con alta frecuencia en países de bajos recursos económicos y por su presencia en aquellos países considerados desarrollados. En este sentido, se estima que existen en el mundo 2800 millones de individuos infectados con geohelmintos, 20 % a 30 % de infectados con Toxoplasma gondii, 300 a 500 millones de casos nuevos de malaria al año y aproximadamente 15 millones de latinoamericanos con enfermedad de Chagas, una enfermedad causada por el Trypanosoma cruzi. En este artículo de revisión narrativa se analiza información disponible en repositorios digitales sobre aspectos del programa pedagógico tradicional de la parasitología humana o médica, para lo cual se emplearon descriptores o palabras clave en estrecha relación con el tema. Los artículos que se revisaron principalmente fueron aquellos publicados en revistas científicas arbitradas, indexadas y de reconocido prestigio. Asimismo, se describen el programa tradicional de parasitología y la pedagogía prevalente empleada, con el propósito de fomentar el debate sobre los métodos que conducen a su aprendizaje. Por otro lado, si se consideran el carácter dinámico que posee este proceso y los constantes desafíos que deben afrontarse en este campo, esta información puede ayudar a explorar nuevas formas de enseñar la parasitología en respuesta a las exigencias del contexto. En conclusión, las enfermedades parasitarias han afectado a la humanidad a lo largo de la historia, y han causado enfermedades, discapacidad y la muerte de millones de personas. Por tanto, entre las medidas para combatir tan terrible flagelo se señala la capacitación de más y mejores profesionales en el área, por su papel preponderante en el diseño y ejecución de los programas de control, de lo que se desprende la necesidad de describir en detalle las características de la enseñanza tradicional de esta rama del conocimiento ―como se muestra en el contenido de este escrito― en virtud de la existencia de nuevos métodos de enseñanza humana: la enseñanza participativa, aprendizaje basado en problemas y aprendizaje asistido por internet.

Chagas disease is a relevant public health threat that affects over 6 million people worldwide, resulting in devastating social and economic consequences. Moreover, the therapeutic options are limited, highlighting the urgency in searching for novel active antitrypanosomal molecules. Compounds with either thiazole or biaryl units have been described as possessing anti Trypanosoma cruzi activities. Therefore, here, we describe the synthesis of nine arylated and diarylated thiazole derivatives and the evaluation of their in vitro toxicity on mammalian cells as well as their anti T. cruzi activity. The compounds were prepared in straightforward synthetic routes, using Hantzsch thiazole synthesis and cross-coupling reactions as key steps. A pyridyl-phenyl-thiazole (PPT) derivative (4c) presented 76% of T. cruzi growth inhibition in preliminary tests using a fixed concentration of 20 µM. This compound was used as a scaffold for the synthesis of two novel PPT analogs (4g and 4h). Dose-response assays on intracellular forms of T. cruzi demonstrated that these three compounds presented high antiparasitic potency (half maximal effective concentration (EC50) values ranging from 1.15 to 2.38 μM) and low toxic profile against L929 cell lines. Hence, these findings highlight the pyridyl-phenyl-thiazole backbone as a novel privileged scaffold in the search for active molecules against T. cruzi. worldwide consequences Moreover limited activities Therefore here T activity routes crosscoupling cross coupling steps pyridylphenylthiazole pyridyl phenyl (PPT 4c c (4c 76 2 µM 4g g 4h. 4h h . 4h) Doseresponse Dose response half EC50 EC (EC50 115 1 15 1.1 238 38 2.3 μM L L92 lines Hence 7 EC5 (EC5 11 1. 23 3 2. L9 (EC

ABSTRACT Background: Chagas disease, a zoonosis transmitted mainly by hematophagous insects of the subfamily Triatominae, is caused by Trypanosoma cruzi, classified into six discrete typing units (DTUs: TcI-TcVI and Tcbat). Methods: Insect vectors were collected from 84 human dwellings in the municipality of Santo Domingo Tehuantepec, Oaxaca, Mexico; 4.76% were infested. DTUs were determined using conventional and nested PCR. Results: The infection rate was 43.6%. All insects were infected with TcI while one specimen showed mixed infection with TcII. Conclusions: This is the first report of T. cruzi mixed infection in Triatoma phyllosoma, its main vector in the study region. Background disease Triatominae (DTUs TcITcVI TcVI Tcbat. Tcbat . Tcbat) Methods 8 Tehuantepec Oaxaca Mexico 476 4 76 4.76 infested PCR Results 436 43 6 43.6% TcII Conclusions T phyllosoma region 47 7 4.7 43.6 4. 43.

ABSTRACT Trypanosomatids are an important group of parasites that predominate in tropical and subtropical areas of the planet, which cause diseases that are classified as forgotten and neglected by the world health organization. In this group of parasites, we find Trypanosoma cruzi, Trypanosoma brucei, Trypanosoma brucei rhodesiense and Leishmania spp, for which there is no vaccine available, and its control has focused mainly on pharmacological treatment. Due to the poverty situation where these diseases are found and the biological complexity of these parasites, there are multiple variables to control, including the diversity of species, the complexity of their life cycles, drug resistance, cytotoxicity, the limited use in pregnant women, the high costs of treatment and the little-known pharmacological mechanisms of action, among others. It is therefore necessary to find new strategies and approaches for the treatment of these parasitic diseases. Among these new approaches is the rational search for new targets based on the allosteric inhibition of protein kinases, which have been little studied in trypanosomatids. Among these kinases, we find Glycogen Synthase Kinase-3 (GSK-3), a kinase of great pharmacological interest, which is under intense basic and clinical research by pharmaceutical companies for the treatment of cancer. This kinase, highly studied in the PI3K/AKT/mTOR pathway signaling in humans, has an orthologous gene in these parasites (GSK-3 s), which has proven to be essential for them in response to different challenges; Therefore, it is notable to increase research in this kinase in order to achieve a broad structural and functional characterization in the different species of trypanosomatids. planet organization cruzi spp available cycles resistance cytotoxicity women littleknown known action others kinases trypanosomatids Kinase3 Kinase 3 Kinase- GSK3, GSK3 GSK , (GSK-3) interest cancer PI3KAKTmTOR PIKAKTmTOR PI3K AKT mTOR PI K humans (GSK- s, s s) challenges Therefore KAKTmTOR PIK (GSK

BACKGROUND Conventional microscopic counting is a widely utilised method for evaluating the trypanocidal effects of drugs on intracellular amastigotes. This is a low-cost approach, but it is time-consuming and reliant on the expertise of the microscopist. So, there is a pressing need for developing technologies to enhance the efficiency of low-cost anti-Trypanosoma cruzi drug screening. OBJECTIVES In our laboratory, we aimed to expedite the screening of anti-T. cruzi drugs by implementing a fluorescent method that correlates emitted fluorescence from green fluorescent protein (GFP)-expressing T. cruzi (Tc-GFP) with cellular viability. METHODS Epimastigotes (Y strain) were transfected with the pROCKGFPNeo plasmid, resulting in robust and sustained GFP expression across epimastigotes, trypomastigotes, and intracellular amastigotes. Tc-GFP epimastigotes and intracellular amastigotes were exposed to a serial dilution of benznidazole (Bz). Cell viability was assessed through a combination of microscopic counting, MTT, and fluorimetry. FINDINGS The fluorescence data indicated an underestimation of the activity of Bz against epimastigotes (IC50 75 µM x 14 µM). Conversely, for intracellular GFP-amastigotes, both fluorimetry and microscopy yielded identical IC50 values. Factors influencing the fluorimetry approach are discussed. MAIN CONCLUSIONS Our proposed fluorometric assessment is effective and can serve as a viable substitute for the time-consuming microscopic counting of intracellular amastigotes. lowcost low cost timeconsuming time consuming microscopist So antiTrypanosoma anti Trypanosoma laboratory antiT. antiT T anti-T GFPexpressing expressing TcGFP Tc (Tc-GFP Y strain plasmid trypomastigotes Bz. . (Bz) MTT IC (IC5 7 1 µM. µM) Conversely GFPamastigotes, GFPamastigotes amastigotes, GFP-amastigotes IC5 values discussed (Bz (IC

ABSTRACT Background: We assessed the distribution of triatomines in an endemic area for Chagas disease. Methods: This retrospective study used secondary data extracted from the Official System of the National Chagas Disease Control Program (Sistema Oficial do Programa Nacional de Controle da Doença de Chagas - SisPCDCh). Results: A total of 7,257 (725.7 ± 221.7 per year) specimens were collected from 2013 to 2022. Most of them (6,792; 93.6%) were collected in the intradomicile and 465 (6.4%) in the peridomicile. A total of 513 (7.1%) triatomines tested positive for the presence of trypomastigote forms, similar to Trypanosoma cruzi. Conclusions: The spatial analysis revealed a heterogeneous distribution of triatomines across different municipalities. Background disease Methods Sistema SisPCDCh. SisPCDCh . SisPCDCh) Results 7257 7 257 7,25 725.7 725 (725. 2217 221 221. year 201 2022 6,792 6792 6 792 (6,792 93.6% 936 93 46 6.4% 64 4 (6.4% peridomicile 51 7.1% 71 1 (7.1% forms cruzi Conclusions municipalities 25 7,2 725. 72 (725 22 20 202 6,79 679 79 (6,79 93.6 9 6.4 (6.4 5 7.1 (7.1 2 7, (72 6,7 67 (6,7 93. 6. (6. 7. (7. (7 6, (6, (6 (

Chagas disease is a public health problem, particularly in Latin America. The available treatment consists of two poorly effective drugs in the chronic phase of this parasitic disease. Considering the lack of effective treatment, alternatives are sought, such as the search focused on the biological targets of the etiologic agent. Based on this strategy, the role of Trypanosoma cruzi sterol 14α-demethylase (TcCYP51) in ergosterol seems promising. In this work, we apply the virtual screening approach to a proposal to repurpose U.S. Food and Drug Administration (FDA) approved drugs. We combined computational techniques and used rigorous validation to identify putative inhibitors from the FDA-approved drug library. The results indicated one of these drugs as a putative inhibitor of the TcCYP51 enzyme. problem America sought agent strategy 14αdemethylase αdemethylase 14α demethylase α TcCYP (TcCYP51 promising work US U S U.S FDA (FDA FDAapproved library TcCYP5 enzyme (TcCYP5 (TcCYP

Abstract Disorders of gastrointestinal motility are the major physiologic problem in chagasic megacolon. The contraction mechanism is complex and controlled by different cell types such as enteric neurons, smooth muscle, telocytes, and an important pacemaker of the intestine, the interstitial cells of Cajal (ICCs). The role of ICCs in the progression of acute and chronic Chagas disease remains unclear. In the present work, we investigate the aspects of ICCs in a long-term model of Chagas disease that mimics the pathological aspects of human megacolon. Different subsets of ICCs isolated from Auerbach’s myenteric plexuses and muscle layers of control and Trypanosoma cruzi infected animals were determined by analysis of CD117, CD44, and CD34 expression by flow cytometer. Compared with the respective controls, the results showed a reduced frequency of mature ICCs in the acute phase and three months after infection. These results demonstrate for the first time the phenotypic distribution of ICCs associated with functional dysfunction in a murine model of chagasic megacolon. This murine model proved valuable for studying the profile of ICCs as an integrative system in the gut and as a platform for understanding the mechanism of chagasic megacolon development. neurons telocytes intestine ICCs. . (ICCs) unclear work longterm long term Auerbachs Auerbach s CD117 CD CD44 CD3 cytometer controls infection development (ICCs CD11 CD4 CD1