Influence of sexual hormones on Chagas disease / Influencia de las hormonas sexuales en la enfermedad de Chagas

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.

Influencia de la inoculación oral en la enfermedad de Chagas en modelo murino / Oral inoculation influence on Chagas disease in a murine model

Resumen: Objetivo: Determinar el comportamiento de la enfermedad de Chagas, comparando la vía de inoculación intraperitoneal (i.p.) y la vía oral (v.o.), mediante la ingestión alimentos infectados con Trypanosoma cruzi (T. cruzi). Materiales y métodos: En modelo murino, se comparó la parasitemia en la infección adquirida vía i.p. y vía oral Se formaron dos grupos que fueron inoculados con la cepa NINOA de T. cruzi (3x103); uno se administró v.o. y otro, se administró vía i.p. Además, se realizó un estudio histopatológico del tejido cardiaco de los individuos. Finalmente, se determinó y comparó la respuesta inmune montada como resultado de la inoculación por ambas vías, evaluando la concentración de IgG séricas contra T. cruzi mediante la realización de una ELISA casera. Resultados: El comportamiento de la infección fue diferente en ambas vías de inoculación. A través de los métodos parasitoscópicos e histopatológicos empleados, no fue detectable la infección en aquellos individuos infectados vía oral, interesantemente, la infección sí fue detectable mediante métodos inmunológicos. Aquellos individuos infectados vía oral empleando açaí, tuvieron un comportamiento inmune similar al presentado por aquellos inoculados vía i.p. Conclusiones: El presente estudio demuestra que la vía de infección del hospedero es determinante para la evolución de la enfermedad. Este trabajo proporciona evidencia para que en la práctica clínica, se realice a los individuos más de una prueba diagnóstica, hecho que, ayudará a un mejor manejo de la enfermedad de Chagas.

Abstract: Objective: Determine the behavior of Chagas's disease, comparing the intraperitoneal (i.p.), and the oral (v.o.) administration routes, by the ingestion of T. cruzi-contaminated food. Materials and methods: In mice, parasitemia oral and intraperitoneal acquiring routes were compared. Two groups were inoculated with T. cruzi (3x103) NINOA strain: one orally, and another intraperitoneally. Additionally, a hearth tissue histopathologic analysis was performed. Finally, the immune response triggered by both inoculation routes was determined by a homemade ELISA and compared. Results: The infection behavior was different in each inoculation route. In the orally infected group, infection was undetectable by parasitological, and histopathologic methods; interestingly, infection was detected by immune methods. Orally infected individuals using acai behaved similarly to intraperitoneally inoculated ones. Discussion: The vector and hosts close coexistence promote several infection routes. To improve the diagnosis, disease's course variants knowledge is needed. Conclusion: This study shows that the infection route strongly influences Chagas's disease course. Moreover, this work provides evidence that support the fact of doing more than one diagnostic test, improving the disease management.

Hypothyroid offspring replacement with euthyroid wet nurses during lactation improves thyroid programming without modifying metabolic programming

ABSTRACT Objective Determine the milk quality effect during lactation on the metabolic and thyroid programming of hypothyroid offspring. Materials and methods Ten-week-old female Wistar rats were divided into two groups: euthyroid and thyroidectomy-caused hypothyroidism. The rats were matted and, one day after birth, the pups were divided into three groups: euthyroid offspring (EO), hypothyroid offspring (HO) and hypothyroid with a euthyroid replacement wet nurse (HRO). During lactation, the milk quality and offspring body length were evaluated. The body weight and energy intake were determined on a weekly basis, as well as the metabolic profile at the prepubertal (P35-36) and postpubertal (P55-56) ages. At P56, the animals were sacrificed, the adipose tissues were weighed and the thyroid glands were dissected for histological processing. Results The milk of the hypothyroid wet nurse decreases proteins (16-26%), lipids (22-29%) and lactate (22-37%) with respect to euthyroid. The HO has a lower body weight gain (23-33%), length (11-13%) and energy intake (15-21%). In addition, HO presents impaired fasting glucose and dyslipidemia, as well as a reduction in seric thyroid hormone (18-34%), adipose reserves (26-68%) and thyroid gland weight (25-34%). The HO present thyroid gland cytoarchitecture alteration. The HRO develop the same metabolic alterations as the HO. However, the thyroid gland dysfunction was partially prevented because the HRO improved under about 10% of the serum thyroid hormone concentration, the thyroid gland weight although histological glandular changes presented. Conclusions The replacement of hypothyroid offspring with a euthyroid wet nurse during lactation can improve the thyroid programming without modifying metabolic programming.

An improved histochemical technique for differentiating adrenaline-and noradrenaline-containing cells

Background. Sevki's histochemical technique allows specific staining of catechomamine-containing cells, yet discrimiantion between adrenaline-(ADR-) cells and noradrenaline-(NOR-) cells is unrealiable, being based on hue differences. Methods. In this work, histochemical differentiation of ADR- and NOR-cells in rat adrenal medulla was carried out by introducing two modifications to Sevki's technique: 1) employment of aged Giemsa solution, and 2) addition of an alkaline differentiating step. Results. With these changes, ADR-cell stained brown, whereas NOR-cells were deep-green, resulting in a clear-cut differentiation. Conclusions. The modified technique permits to differentiate ADR- from NOR-cells in the adrenal medulla using only a bright field microscope without any sophisticated equipment. The present procedure is inexpensive and easy to carry out