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.

In vitro effect of diazoxon on cell signaling and second messengers in Nile tilapia (Oreochromis niloticus) leukocytes.

The physiological and molecular responses of leukocytes are altered by organophosphate pesticides. Some reports have shown that diazinon causes immunotoxic effects; diazoxon, the oxon metabolite of diazinon, is attributed to influence the immune response by affecting the leukocyte cholinergic system. In this study, the in vitro effects of diazoxon on molecules involved in cell signaling (cAMP, IP3, DAG, JAK1, and STAT3), which play a crucial role in the activation, differentiation, and survival of leukocytes, were evaluated. Data indicate that diazoxon leads to a decrease in cAMP concentration and an increase in basal IP3 levels. However, diazoxon does not affect basal levels of JAK1 and STAT3 phosphorylation. Instead, diazoxon inhibits leukocyte responsiveness to phorbol myristate acetate and ionomycin, substances that, under normal conditions, enhance JAK/STAT signaling. These findings demonstrate that diazoxon significantly affects key molecular parameters related to cell signaling.

Genetic Markers as Predictors for Response to Treatment and Possible Therapeutic Targets in Medulloblastoma.

BACKGROUND: Medulloblastomas (MB) are the most common malignant brain tumors in the pediatric age. In 2021, WHO categorized medulloblastomas into two groups: molecularly defined and histologically defined medulloblastomas. Molecularly defined medulloblastomas are divided into WNTactivated medulloblastoma, SHH-activated and TP53-wildtype medulloblastoma, SHH-activated, and TP53-mutant and non-WNT/non-SHH medulloblastoma, which include Group 3 (MYC) and Group 4 (CDK6 and MYCN). In this paper, we will focus on molecularly defined medulloblastomas. OBJECTIVE: This paper aims to review the literature in order to describe the molecular structure of the medulloblastoma groups and to emphasize the importance of genetic predictors in medulloblastoma that can be used in clinical practice, either as a prognostic tool or as a therapeutic target in the future. RESULTS: Each molecular subtype of medulloblastoma presents a different prognosis, and the molecular subtype with the best prognosis is medulloblastoma-activated WNT. It has even been observed that a reduction in the intensity of the combined treatment does not modify the prognosis of the patients, resulting in even fewer adverse effects due to the treatment. On the other hand, it was observed that the subtypes with the worst prognosis are medulloblastomas with activated MYC and medulloblastomas with activated SHH and mutated TP53, due to their high capacity to metastasize or to their radio-resistance. However, a new target therapy has emerged that could help improve the prognosis in these patients. CONCLUSION: The deeper knowledge of the molecular pathways involved in the appearance and progression of medulloblastomas will allow us to offer a prognosis at the time of diagnosis and more specific treatments through the development of the targeted therapy.

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.

Cell proliferation and inhibition of apoptosis are related to c-Kit activation in leukaemic lymphoblasts.

Receptor tyrosine kinase (RTK) activity may contribute to carcinogenesis. The c-Kit receptor, a member of the RTK family, is expressed in immature haematopoietic system cells. Acute lymphoblastic leukaemia (ALL) presents incompletely differentiated lymphoblasts, and consequently, c-Kit expression can be detected in these cells. The BCR-ABL kinase, which is usually present in both ALL and chronic myeloid leukaemia, can trigger signalling pathways with neoplastic effects. However, a certain number of ALL patients and chronic myeloid leukaemia patients do not express this kinase, raising the question of which other proteins that intervene in signalling pathways may be involved in the development of these diseases. OBJECTIVES: To test whether c-Kit has proliferative effects and affects the inhibition of apoptosis of leukaemic lymphoblasts that do not express BCR-ABL. METHODS: We cultured RS4:11 lymphoblasts and analysed the expression and activation of c-Kit by immunofluorescence, and flow cytometry, evaluation of cell proliferation, apoptosis, cyclin D1 and Bak expression were carried out by flow cytometry; activation of AKT and survivin expression were tested by immunoblot. RESULTS: The c-Kit receptor was found to induce proliferation and to increase the expression of cyclin D1 via the PI3K/AKT/NF-kB signalling pathway. Additionally, the c-Kit/PI3K/AKT pathway increased the inhibition of apoptosis and survivin expression. Similarly, c-Kit was observed to reduce the expression of the pro-apoptotic Bak protein. CONCLUSION: These results suggest that, in leukaemic lymphoblasts, c-Kit triggers a signalling pathway with proliferative and anti-apoptotic effects; information to this effect has not yet been reported in the literature.

A Canola Oil-Supplemented Diet Prevents Type I Diabetes-Caused Lipotoxicity and Renal Dysfunction in a Rat Model.

We investigated the effect of a canola oil-supplemented diet on the metabolic state and diabetic renal function of a type I diabetes experimental model. Male Sprague-Dawley rats were randomly divided into four groups: (1) normoglycemic+chow diet, (2) normoglycemic+a canola oil-supplemented chow diet, (3) diabetic+chow diet, and (4) diabetic+a canola oil-supplemented chow diet. For 15 weeks, animals were fed a diet of Purina rat chow alone or supplemented with 30% canola oil. Energetic intake, water intake, body weight, and adipose tissue fat pad were measured; renal function, electrolyte balance, glomerular filtration rate, and the plasmatic concentration of free fatty acids, cholesterol, triglycerides, and glucose were evaluated. The mesenteric, retroperitoneal, and epididymal fat pads were dissected and weighed. The kidneys were used for lipid peroxidation (LP) and reactive oxygen species (ROS) quantifications. Diabetic rats fed with a canola oil-supplemented diet had higher body weights, were less hyperphagic, and their mesenteric, retroperitoneal, and epididymal fat pads weighed more than diabetic rats on an unsupplemented diet. The canola oil-supplemented diet decreased plasmatic concentrations of free fatty acids, triglycerides, and cholesterol; showed improved osmolarity, water clearances, and creatinine depuration; and had decreased LP and ROS. A canola oil-supplemented diet decreases hyperphagia and prevents lipotoxicity and renal dysfunction in a type I diabetes mellitus model.

Hypothyroidism minimizes the effects of acute hepatic failure caused by endoplasmic reticulum stress and redox environment alterations in rats.

The aim of this study was to investigate if a protective effect from hypothyroidism in acute liver failure resulted from reduced endoplasmic reticulum stress and changes to the redox environment. Twenty male Sprague-Dawley rats were divided in four groups: (1) euthyroid (sham surgery), (2) hypothyroid, (3) euthyroid (sham surgery)+thioacetamide and (4) hypothyroid+thioacetamide. Hypothyroidism was confirmed two weeks after thyroidectomy, and thioacetamide (TAA) (400mg/kg, ip) was administrated to the appropriate groups for three days with supportive therapy. Grades of encephalopathy in all animals were determined using behavioral tests. Animals were decapitated and their blood was obtained to assess liver function. The liver was dissected: the left lobe was used for histology and the right lobe was frozen for biochemical assays. Body weight, rectal temperature and T4 concentration were lower in hypothyroid groups. When measurements of oxidative stress markers, redox environment, γ-glutamylcysteine synthetase and glutathione-S-transferase were determined, we observed that hypothyroid animals with TAA compensated better with oxidative damage than euthyroid animals treated with TAA. Furthermore, we measured reduced expressions of GADD34, caspase-12 and GRP78 and subsequently less hypothyroidism-induced cellular damage in hypothyroid animals. We conclude that hypothyroidism protects against hepatic damage caused by TAA because it reduces endoplasmic reticulum stress and changes to the redox environment.

Hypothyroidism maintained reactive oxygen species-steady state in the kidney of rats intoxicated with ethylene glycol: effect related to an increase in the glutathione that maintains the redox environment.

Our objective was to determine whether hypothyroidism protects against ethylene glycol (EG)-induced renal damage and whether the redox environment participates in the protection process. We used 36 male Wistar rats divided into four groups: (1) euthyroid, (2) euthyroid + 0.75% EG, (3) hypothyroid, and (4) hypothyroid + 0.75% EG. Hypothyroidism occurred 2 weeks after thyroidectomy. The parathyroid gland was reimplanted. EG was administrated for 21 days in drinking water. On day 21, the renal function was assessed and then the rats were decapitated. The left kidney was processed for histology, and the right kidney was used to determine the redox environment, oxidative stress, and the testing of the antioxidant enzymatic system. EG in euthyroid rats reduced the hydric and electrolytic balance and it also caused oxidative stress and renal damage. Hypothyroidism per se modifies the renal function causing a low osmolal and potassium clearance and the filtered load of potassium and sodium. In addition, there was an enhanced redox state because hypothyroidism increases the reduced glutathione concentration caused by a high activity of γ-glutamylcysteine synthase. Hypothyroidism is a protective state against EG because the changes in the renal function were smaller than in the euthyroid state. The oxidative stress and cellular damage were ameliorated by the hypothyroid condition. Also, the hypothyroidism-enhanced redox environment protects against EG-induced oxidative stress, renal damage, and renal dysfunction.

An increase of oxidative stress markers and the alteration of the antioxidant enzymatic system are associated with spleen damage caused by methimazole-induced hypothyroidism.

Methimazole is the most widely used antithyroid drug in Europe and North America, but it causes several undesirable side effects, such as hematological dysfunctions and immunosuppression. Our aim in this work was to compare, over a time course, markers of oxidative stress, the redox environment, the antioxidant enzymatic system, and the glutathione cycle in the spleen of rats with methimazole- or thyroidectomy-caused hypothyroidism. We used 70-male Wistar rats divided into four groups: 1) euthyroid; 2) sham thyroidectomy; 3) thyroidectomy-caused hypothyroidism, with parathyroid reimplant; and 4) methimazole-caused hypothyroidism. Five rats of the euthyroid- and methimazole-caused hypothyroidism groups were killed at the end of weeks 1, 2, 3, and 4 after treatment, and 5 rats of the sham thyroidectomy and thyroidectomy-caused hypothyroidism groups were killed at the end of weeks 2, 4, and 8 after the surgical procedure. Each spleen was excised and stored at -70°C until oxidative stress, REDOX environment, and the antioxidant enzymatic-system markers were tested. The histological study showed that only methimazole-induced hypothyroidism caused cell damage. This damage was associated with an increase of oxidative-stress markers that were not compensated for by the antioxidant system. The increase of the glutathione-cycle enzymes was insufficient to prevent oxidative-stress markers. Methimazole causes oxidative stress and cell damage in the spleen, whereas hypothyroidism per se does not cause cell damage in this organ. Therefore, it is necessary to develop new antithyroid drugs without causing oxidative stress and cellular damage.

Methimazole-induced hypothyroidism causes alteration of the REDOX environment, oxidative stress, and hepatic damage; events not caused by hypothyroidism itself.

UNLABELLED: Our objective was to compare, over a time-course, markers of oxidative stress, the REDOX environment, and the antioxidant enzymatic system in the liver of rats with methimazole- or thyroidectomy-caused hypothyroidism. METHODS: We used 60 male Wistar rats divided into four groups: 1) the euthyroid, which received only tap water, 2) false thyroidectomy, which received the surgery and postoperative treatment, 3) thyroidectomy-caused hypothyroidism, which had the thyroid gland removed and a parathyroid reimplant, and 4) methimazole-caused hypothyroidism in rats that received 60 mg/kg/d of the antithyroid drug in drinking water. Five rats of the euthyroid and methimazole-caused hypothyroidism groups were killed at the end of the first, second, third, and fourth week after treatment, and five rats of false thyroidectomy and thyroidectomy-caused hypothyroidism groups were killed at the end of the second and eighth week after the surgical procedure. Each liver was removed and stored at -70 degrees C until oxidative stress, REDOX environment, and antioxidant enzymatic system markers were tested. We also made a histological study at the end of the treatment. RESULTS: The histological study revealed that only the methimazole-caused hypothyroidism caused cell damage. This damage is associated with an increase of oxidative stress markers that were not compensated for by the antioxidant system. The catalase activity is reduced and this allows H2O2-caused damage. In conclusion methimazole causes cell damage in the liver, whereas hypothyroidism per se does not cause hepatic-cell damage.

Lidocaine affects the redox environment and the antioxidant enzymatic system causing oxidative stress in the hippocampus and amygdala of adult rats.

AIMS: Our objective was to investigate if oxidative stress is involved in the neural damage caused by lidocaine. MAIN METHODS: Male Wistar rats were used. The control group received 0.9% saline ip and the treated group received a single 60 mg/kg lidocaine dose ip. On days 1, 2, 5, and 10 after dosing, ten rats were sacrificed and their brains were quickly removed. The amygdala and hippocampus were dissected. Five samples were used to determine lipid peroxidation, reactive oxygen species (ROS), reduced glutathione (GSH), and oxidized glutathione (GSSG). Another five were used to measure antioxidant activities of glutathione peroxidase (GPX), catalase, Cu-Zn SOD (superoxide dismutase), Mn SOD, and total SOD. KEY FINDINGS: Ten days after injection of lidocaine, lipid peroxidation increases in the hippocampus because the ROS are enhanced from day 5, whereas in the amygdala lipid peroxidation and the ROS were enhanced only on the first day postinjection. Lidocaine causes an increased concentration of GSH and GSSG in the hippocampus from the first day. In the amygdala the GSH and GSSG content were increased at day 10. In the hippocampus the catalase activity was enhanced, whereas the total SOD and Cu-Zn SOD activities were decreased. In the amygdala the lidocaine enhances the activities of catalase and GPX, but no SOD isoenzymes were modified. SIGNIFICANCE: In this research we demonstrated that lidocaine affects the redox environment and promotes increases of the oxidative markers both in the hippocampus and amygdala but in a different pattern.

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