Asociación del riesgo a desarrollar diabetes mellitus tipo 2 según la calculadora de la asociación americana de diabetes (ADA) y los hábitos tóxicos no ilícitos en pacientes que residen en una comunidad rural de Peravia, República Dominicana / Association of the risk of developing type 2 diabetes mellitus according to the American Diabetes Association (ADA) calculator and non-illicit toxic habits in patients residing in a rural community in Peravia, Dominican Republic

Introducción: la diabetes mellitus tipo 2 (DM2) se define como un trastorno metabólico caracterizado por niveles de glucosa en sangre crónicamente elevados. La DM2 representa el paradigma de las enfermedades crónicas en las que existe una estrecha asociación entre factores familiares y ambientales. Por este motivo, este estudio tiene como finalidad determinar la asociación del riesgo a desarrollar DM2 y los hábitos tóxicos no ilícitos en pacientes que residen en una comunidad rural de Peravia, República Dominicana. Tales incluyen: alcohol, café y té. Metodología: Estudio observacional, transversal, analítico y prospectivo. Se aplicó cuestionario, recolectaron datos antropométricos y se determinó glucosa capilar a la muestra (n=304). Resultados: la prevalencia a presentar un alto riesgo a desarrollar DM2 en la población es de 35.5%, mientras que la prevalencia a presentar riesgo bajo es de 64.5%. En cuanto a hábitos tóxicos, no existió correlación positiva entre consumo de té y desarrollo de DM2. Sin embargo, sí entre el consumo de café y alcohol. Conclusiones: los habitantes de salinas presentan un bajo riesgo a desarrollar DM2, pero utilizan factores de riesgos modificables que aumentan la prevalencia a DM2.

Introduction: Type 2 diabetes mellitus (DM2) is defined as a metabolic disorder characterized by chronically elevated blood glucose levels. DM2 represents the paradigm of chronic diseases in which there is a close association between family and environmental factors. Therefore, the purpose of this study is to determine the association of the risk of developing DM2 and non-illicit toxic habits in patients residing in a rural community in Peravia, Dominican Republic. Such habits include alcohol, coffee and tea. Methodology: Observational, cross-sectional, analytical and prospective study. A questionnaire was applied, anthropometric data was collected, and capillary glucose was determined in the study sample (n=304). Results: the prevalence of presenting a high risk of developing DM2 in the population is 35.5%, while the prevalence of presenting low risk is 64.5%. Regarding toxic habits, there was no positive correlation between tea consumption and the development of DM2. However, this result differed between consumption of coffee and alcohol. Conclusions: the inhabitants of Salinas have a low risk of developing DM2 but are subject to modifiable risk factors that increase said prevalence.

WNT pathway in focal cortical dysplasia compared to perilesional nonlesional tissue in refractory epilepsies.

BACKGROUND: Focal cortical dysplasia (FCD) is a malformation of cortical development that causes medical refractory seizures, and one of the main treatments may be surgical resection of the affected area of the brain. People affected by FCD may present with seizures of variable severity since childhood. Despite many medical treatments available, only surgery can offer cure. The pathophysiology of the disease is not yet understood; however, it is known that several gene alterations may play a role. The WNT/ß-catenin pathway is closely related to the control and balance of cell proliferation and differentiation in the central nervous system. The aim of this study was to explore genes related to the WNT/ß-catenin pathway in lesional and perilesional brain tissue in patients with FCD type II. METHODS: Dysplastic and perilesional tissue from the primary dysplastic lesion of patients with FCD type IIa were obtained from two patients who underwent surgical treatment. The analysis of the relative expression of genes was performed by a qRT-PCR array (super array) containing 84 genes related to the WNT pathway. RESULTS: Our results suggest the existence of molecular alteration in some genes of the WNT pathway in tissue with dysplastic lesions and of perilesional tissue. We call this tissue of normal-appearing adjacent cortex (NAAC). Of all genes analyzed, a large number of genes show similar behavior between injured, perilesional and control tissues. However, some genes have similar characteristics between the perilesional and lesional tissue and are different from the control brain tissue, presenting the perilesional tissue as a molecularly altered material. CONCLUSION: Our results suggest that the perilesional area after surgical resection of tissue with cortical dysplasia presents molecular changes that may play a role in the recurrence of seizures in these patients. The perilesional tissue should receive expanded attention beyond the somatic mutations described and associated with FCD, such as mTOR, for example, to new signaling pathways that may play a crucial role in seizure recurrence.

The role of Wnt signaling in Xenopus neural induction.

Development of the central nervous system in amphibians has called attention from scientists for over a century. Interested in the matter of embryonic inductions, Hans Spemann and Hilde Mangold found out that the dorsal blastopore lip of the salamander's embryo has organizer properties. Such an ectopic graft could induce structures in the host embryo, including a neural tube overlying the notochord of a perfect secondary body axis. A couple of decades later, the frog Xenopus laevis emerged as an excellent embryological experimental model and seminal concepts involving embryonic inductions began to be revealed. The so-called primary induction is, in fact, a composition of signaling and inductive events that are triggered as soon as fertilization takes place. In this regard, since early 1990s an intricate network of signaling pathways has been built. The Wnt pathway, which began to be uncovered in cancer biology studies, is crucial during the establishment of two signaling centers in Xenopus embryogenesis: Nieuwkoop center and the blastula chordin noggin expression center (BCNE). Here we will discuss the historical events that led to the discovery of those centers, as well as the molecular mechanisms by which they operate. This chapter highlights the cooperation of both signaling centers with potential to be further explored in the future. We aim to address the essential morphological transformation during gastrulation and neurulation as well as the role of Wnt signaling in patterning the organizer and the neural plate.

Strain Magnitude Assessed at Rest and During Stress Echocardiography in Patients with Normal Coronary Flow Reserve

Abstract Background Coronary flow and myocardial contractile performance assessed by strain magnitude increase during a dobutamine stress echocardiogram (DSE). Normal coronary flow reserve (CFR) can be attained upon completion of a DSE at age-predicted maximum heart rate (HR) (HRmax = 220 - age)] or submaximal HR [(0.85) HRmax] or before completion (early CFR). Objective To ascertain the association between delta strain and HR in patients with early normal CFR. Methods This prospective study included patients whose normal CFR was obtained before the DSE was completed. Percentage of resting HR (%HRrest) = [(HRrest ÷ HRmax) 100]% and %HR CFR = [(HR at the time of CFR attainment) ÷ (HRmax) 100]% were recorded. Strain was assessed in the left ventricular region of interest, and delta strain was calculated as the difference between the measures obtained at HRrest and after the DSE was completed. Strain agreement analysis for HRrest, %HRrest, and %HR CFR was performed using the kappa coefficient. The Shapiro-Wilk test was used to assess data normality, and the Mann-Whitney test was used to compare the groups. A p-value < 0.05 was considered statistically significant. Results Strain measured -23.3% ± 4.3% at baseline and -31.1% ± 4.9% during the DSE. In delta strain > 8 absolute points, the ROC curves showed an area under the curve of 0.874 ± 0.07 for %HRrest (p = 0.001) and an area under the curve of 0.862 ± 0.07 for %HR CFR (p = 0.001). In delta strain > 8 points, %HRrest ≤ 42.6% of HRmax and %HR CFR ≤ 62.5% of HRmax showed an accuracy of 82.9% and 79.8%, respectively. Conclusion In this study, lower HRrest and HR at the time of CFR attainment had a good association with better myocardial contractile performance, according to the change in strain magnitude.

The Wnt/Beta-Catenin Pathway and Cytoskeletal Filaments Are Involved in the Positioning, Size, and Function of Lysosomes during Chick Myogenesis.

Lysosomes are highly dynamic organelles involved in the breakdown and recycling of macromolecules, cell cycle, cell differentiation, and cell death, among many other functions in eukaryotic cells. Recently, lysosomes have been identified as cellular hubs for the modulation of intracellular signaling pathways, such as the Wnt/beta-catenin pathway. Here we analyzed morphological and functional characteristics of lysosomes in muscle and non-muscle cells during chick myogenesis, as well as their modulation by the Wnt/beta-catenin pathway. Our results show that (i) muscle and non-muscle cells show differences in lysosomal size and its distribution, (ii) lysosomes are found in spherical structures in myoblasts and fibroblasts and tubular structures in myotubes, (iii) lysosomes are found close to the plasma membrane in fibroblasts and close to the nucleus in myoblasts and myotubes, (iv) lysosomal distribution and size are dependent on the integrity of microtubules and microfilaments in myogenic cells, (v) alterations in lysosomal function, in the expression of LAMP2, and in Wnt/beta-catenin pathway affect the distribution and size of lysosomes in myogenic cells, (vi) the effects of the knockdown of LAMP2 on myogenesis can be rescued by the activation of the Wnt/beta-catenin pathway, and (vii) the chloroquine Lys05 is a potent inhibitor of both the Wnt/beta-catenin pathway and lysosomal function. Our data highlight the involvement of the Wnt/beta-catenin pathway in the regulation of the positioning, size, and function of lysosomes during chick myogenesis.

The Flavonol Quercitrin Hinders GSK3 Activity and Potentiates the Wnt/ß-Catenin Signaling Pathway.

The Wnt/ß-catenin signaling pathway dictates cell proliferation and differentiation during embryonic development and tissue homeostasis. Its deregulation is associated with many pathological conditions, including neurodegenerative disease, frequently downregulated. The lack of efficient treatment for these diseases, including Alzheimer's disease (AD), makes Wnt signaling an attractive target for therapies. Interestingly, novel Wnt signaling activating compounds are less frequently described than inhibitors, turning the quest for novel positive modulators even more appealing. In that sense, natural compounds are an outstanding source of potential drug leads. Here, we combine different experimental models, cell-based approaches, neuronal culture assays, and rodent behavior tests with Xenopus laevis phenotypic analysis to characterize quercitrin, a natural compound, as a novel Wnt signaling potentiator. We find that quercitrin potentiates the signaling in a concentration-dependent manner and increases the occurrence of the Xenopus secondary axis phenotype mediated by Xwnt8 injection. Using a GSK3 biosensor, we describe that quercitrin impairs GSK3 activity and increases phosphorylated GSK3ß S9 levels. Treatment with XAV939, an inhibitor downstream of GSK3, impairs the quercitrin-mediated effect. Next, we show that quercitrin potentiates the Wnt3a-synaptogenic effect in hippocampal neurons in culture, which is blocked by XAV939. Quercitrin treatment also rescues the hippocampal synapse loss induced by intracerebroventricular injection of amyloid-ß oligomers (AßO) in mice. Finally, quercitrin rescues AßO-mediated memory impairment, which is prevented by XAV939. Thus, our study uncovers a novel function for quercitrin as a Wnt/ß-catenin signaling potentiator, describes its mechanism of action, and opens new avenues for AD treatments.

Therapeutic Potential of Naturally Occurring Small Molecules to Target the Wnt/ß-Catenin Signaling Pathway in Colorectal Cancer.

Colorectal cancer (CRC) ranks second in the number of cancer deaths worldwide, mainly due to late diagnoses, which restrict treatment in the potentially curable stages and decrease patient survival. The treatment of CRC involves surgery to remove the tumor tissue, in addition to radiotherapy and systemic chemotherapy sessions. However, almost half of patients are resistant to these treatments, especially in metastatic cases, where the 5-year survival rate is only 12%. This factor may be related to the intratumoral heterogeneity, tumor microenvironment (TME), and the presence of cancer stem cells (CSCs), which is impossible to resolve with the standard approaches currently available in clinical practice. CSCs are APC-deficient, and the search for alternative therapeutic agents such as small molecules from natural sources is a promising strategy, as these substances have several antitumor properties. Many of those interfere with the regulation of signaling pathways at the central core of CRC development, such as the Wnt/ß-catenin, which plays a crucial role in the cell proliferation and stemness in the tumor. This review will discuss the use of naturally occurring small molecules inhibiting the Wnt/ß-catenin pathway in experimental CRC models over the past decade, highlighting the molecular targets in the Wnt/ß-catenin pathway and the mechanisms through which these molecules perform their antitumor activities.

Benefits of combined interventions for cognitive enhancement in older adults / Benefícios de intervenções combinadas para aprimoramento cognitivo em idosos

Objective: To investigate the effects of different combined interventions (Stimullus, MEMO, physical activity, and psychoeducation) on the cognitive performance of older adults. Methods: This is a quasi-experimental study with pre- and post-intervention. Thirty-four older adults underwent different combined interventions for a period of 48 weeks and were evaluated at three different points (pre-intervention; post-cognitive intervention; post-physical activity or psychoeducation intervention). Cognitive domains (verbal episodic memory, executive function, general cognitive performance) and depressive symptoms were evaluated. Results: Postintervention gains in global, attentional, and mnemonic cognition were observed, as well as a reduction in depressive symptoms. The MEMO intervention + physical activity or psychoeducation resulted in greater cognitive gains, while Stimullus + psychoeducation showed benefits only in evocation and the free learning index, while Stimullus + physical activity resulted in improvement in the investigated variables. Conclusion: The results of these combined interventions appear promising for healthy older adults and the impact of these interventions should be discussed with individual older patients and evaluated more broadly in the context of public health.

Objetivo: Investigar os efeitos de diferentes intervenções combinadas (Stimullus, MEMO, física e psicoeducacional) no desempenho cognitivo de idosos. Metodologia: Trata-se de um estudo quase experimental com pré e pós-intervenção. Trinta e quatro idosos foram submetidos a diferentes intervenções combinadas pelo período de 48 semanas e avaliados em três tempos diferentes (pré-intervenção; pós-intervenção cognitiva; pós-intervenção física ou psicoeducacional), nos quais foram analisados domínios cognitivos (memória episódica verbal, funções executivas, desempenho cognitivo geral) e sintomas depressivos. Resultados: Após as intervenções, observaram-se ganhos na cognição global, atencional e mnemônica, bem como redução dos sintomas depressivos. A intervenção MEMO (física ou psicoeducacional) resultou em maiores ganhos cognitivos, enquanto Stimullus + psicoeducacional demonstrou benefícios apenas no índice de evocação e aprendizagem livre, e Stimullus + atividades físicas não apresentou melhora em nenhuma das variáveis investigadas. Conclusão: Os achados positivos dessas intervenções combinadas parecem promissores no contexto de idosos saudáveis, e o impacto dessas intervenções deve ser discutido em relação às especificidades de cada indivíduo idoso e avaliado mais amplamente no contexto de saúde pública.

Parents' mental health and children's emotional regulation during the COVID-19 pandemic / Saúde mental parental e regulação emocional infantil durante a pandemia de COVID-19 / Salud mental parental y regulación emocional infantil durante la pandemia de COVID-19

ABSTRACT The objectives of the study were to investigate parents' mental health before and during the COVID-19 pandemic; to find correlations between parents' mental health and their perceptions of risk, virus exposure, use of preventive measures, COVID-19 knowledge, and social distancing practices; and to analyze correlations between parents' mental health and their perception about children's emotional regulation (ER). Participants were 69 parents of children aged between 5 and 12. The instruments used were ERC, HADS, ABEP, and a questionnaire about COVID-19. Descriptive analyses, the Wilcoxon test, and Spearman's correlation were conducted. The results indicated increased parental anxiety and depression during the pandemic, and a weak negative correlation between parental anxiety and their children's ER. The pandemic acts as a stressor, which impacts the mental health of both parents and children.

RESUMO Os objetivos do estudo foram investigar a saúde mental parental antes e durante a pandemia da COVID-19; verificar as associações entre saúde mental parental e suas percepções de risco, exposição ao vírus, uso de medidas preventivas, conhecimento sobre a COVID-19 e práticas de distanciamento social; e analisar as relações entre saúde mental parental e suas percepções sobre a Regulação Emocional (RE) infantil. Os participantes desta pesquisa foram 69 pais de crianças entre 5 e 12 anos. Os instrumentos utilizados foram: ERC, HADS, ABEP e questionário sobre a COVID-19. Foram realizadas análises descritivas, Teste de Wilcoxon e correlação de Spearman. Foram encontrados aumento dos níveis de ansiedade e depressão parental durante a pandemia, bem como uma correlação negativa fraca entre ansiedade parental e RE infantil. A pandemia, enquanto agente estressor, tende a impactar a saúde mental de pais e crianças.

RESUMEN Los objetivos del estudio fueron investigar la salud mental de los padres antes y durante la COVID-19; comprobar relaciones entre la salud mental de los padres y sus percepciones de riesgo, exposición a virus, uso de medidas preventivas, conocimiento de COVID-19 y prácticas de distanciamiento social y analizar las correlaciones entre la salud mental de los padres y su percepción sobre la Regulación Emocional (RE) de los niños. Los participantes fueron 69 padres de niños de entre 5 y 12 años. Los instrumentos utilizados fueron ERC, HADS, ABEP y un cuestionario sobre COVID-19. Se realizaron análisis descriptivos, la prueba de Wilcoxon y la correlación de Spearman. Los resultados indicaron aumento en la ansiedad y depresión de los padres; correlación negativa débil entre la ansiedad de los padres y la ER de sus hijos. La pandemia actúa como un factor de estrés, que tiene un impacto en la salud mental de padres e hijos.

5-Fluorouracil disrupts ovarian preantral follicles in young C57BL6J mice.

PURPOSE: 5-Fluorouracil (5-FU), an anti-cancer drug, has been used for hepatoblastoma (HB) chemotherapy in children, who may have impaired  ovarian follicle pool reserve with lasting effects to reproduction. Therefore, this study aimed to investigate 5-FU effects on survival, growth, and morphology of ovarian preantral follicles from C57BL6J young mice. METHODS: Experiments were carried-out both in vivo and in vitro. Mice were treated with 5-FU injection (450 mg/kg i.p) or saline and sacrificed 3 days after to obtain ovaries for histology and molecular biology. Ovaries for in vitro studies were obtained from unchallenged mice and cultured under basic culture medium (BCM) or BCM plus 5-FU (9.2, 46.1, 92.2 mM). Preantral follicles were classified according to developmental stages, and as normal or degenerated. To assess cell viability, caspase-3 immunostaining was performed. Transcriptional levels for apoptosis (Bax, Bcl2, p53, Bax/Bcl2) and Wnt pathway genes (Wnt2 and Wnt4) were also analyzed. Ultrastructural analyses were carried-out on non-cultured ovaries. In addition, ß-catenin immunofluorescence was assessed in mouse ovaries. RESULTS: The percentage of all-types normal follicles was significantly lower after 5-FU challenge. A total loss of secondary normal follicles was found in the 5-FU group. The highest 5-FU concentrations reduced the percentage of cultured normal primordial follicles. Large vacuoles were seen in granulosa cells and ooplasm of preantral follicles by electron microscopy. A significantly higher gene expression for Bax and Bax/Bcl2 ratio was seen after 5-FU treatment. A marked reduction in ß-catenin immunolabeling was seen in 5-FU-challenged preantral follicles. In the in vitro experiments, apoptotic and Wnt gene transcriptions were significantly altered. CONCLUSION: Altogether, our findings suggest that 5-FU can deleteriously affect the ovarian follicle reserve by reducing preantral follicles survival.

UNESCO Chair of Developmental Biology: how an initiative that fostered careers in Developmental Biology impacted Brazilian Science.

The UNESCO Chair in Developmental Biology started in 1998, at the Institute of Biomedical Sciences of the Federal University of Rio de Janeiro, in Brazil. This Chair was a Brazilian-French initiative led by Professor Vivaldo Moura Neto and Professor Nicole Le Douarin, one of the most inspiring Developmental Biologists of the 20th and 21st centuries. The UNESCO Chair wanted to stimulate interest in Developmental Biology among Brazilian students and scientists by organizing annual international courses on Evolution and Developmental Biology at an advanced level. At the Federal University of Rio de Janeiro, the UNESCO Chair established an international laboratory for the permanent training of researchers and the development of research programs in Developmental Biology and related areas. Moreover, the program aimed at establishing an international network connecting Brazilian Universities and research centers in Latin America and Europe. The advanced hands-on courses, symposiums, and workshops promoted by this Chair inspired the careers of many young scientists. They generated new lines of research in Developmental Biology using a variety of animal models. This review does not intend to bring up all the historical events that marked the beginning of Developmental Biology in Brazil. Instead, it will be dedicated to highlighting one specific initiative that inspired a new generation of Developmental Biologists who established important research lines and contributed to the advance of this scientific field in Brazil.

Establishing embryonic territories in the context of Wnt signaling.

This review highlights the work that my research group has been developing, together with international collaborators, during the last decade. Since we were able to establish the Xenopus laevis experimental model in Brazil, we have been focused on understanding early embryonic patterns regarding neural induction and axes establishment. In this context, the Wnt pathway appears as a major player and has been much explored by us and other research groups. Here, we chose to review three published works which we consider to be landmarks within the course of our research and also within the history of modern findings regarding neural induction and patterning. We intend to show how our series of discoveries, when painted together, tells a story that covers crucial developmental windows of early differentiation paths of anterior neural tissue: 1. establishing the head organizer in contrast to the trunk organizer in the early gastrula; 2. deciding between neural ectoderm and epidermis ectoderm at the blastula/gastrula stages, and 3. the gathering of prechordal unique properties in the late gastrula/early neurula.

Discovery of unique African Helicobacter pylori CagA-multimerization motif in the Dominican Republic.

BACKGROUND: Helicobacter pylori (H. pylori) colonizes the human stomach and is a major cause of peptic ulcer disease and gastric cancer. However, although the prevalence of H. pylori is high in Africa, the incidence of gastric cancer is low, and this phenomenon is called to be African enigma. The CagA protein produced by H. pylori is the most studied virulence factor. The carcinogenic potential of CagA is associated with the Glu-Pro-Ile-Tyr-Ala (EPIYA) patterns and CagA-multimerization (CM) motifs. AIM: To better understand the EPIYA patterns and CM motifs of the cagA gene. METHODS: Gastric mucosal biopsy specimens were obtained from 258 patients with dyspepsia living in the Dominican Republic, from which 120 H. pylori strains were cultured. After the bacterial DNA extraction, the EPIYA pattern and CM motif genotypes were determined using a polymerase chain reaction-based sequencing. The population structure of the Dominican Republic strains was analyzed using multilocus sequence typing (MLST). Peptic ulcer disease and gastric cancer were identified via endoscopy, and gastric cancer was confirmed by histopathology. Histological scores of the gastric mucosa were evaluated using the updated Sydney system. RESULTS: All CagA-positive strains carried the Western-type CagA according to the identified EPIYA patterns. Twenty-seven kinds of CM motifs were observed. Although the typical Western CM motif (FPLKRHDKVDDLSKVG) was observed most frequently, the typical East Asian CM motif (FPLRRSAAVNDLSKVG) was not observed. However, "FPLRRSAKVEDLSKVG", similar to the typical East Asian CM motif, was found in 21 strains. Since this type was significantly more frequent in strains classified as hpAfrica1 using MLST analysis (P = 0.034), we termed it Africa1-CM (Af1-CM). A few hpEurope strains carried the Af1-CM motif, but they had a significantly higher ancestral Africa1 component than that of those without the Af1-CM motif (P = 0.030). In 30 cagA-positive strains, the "GKDKGPE" motif was observed immediately upstream of the EPIYA motif in the EPIYA-A segment, and there was a significant association between strains with the hpAfrica1 population and those containing the "GKDKGPE" motif (P = 0.018). In contrast, there was no significant association between the CM motif patterns and histological scores and clinical outcomes. CONCLUSION: We found the unique African CM motif in Western-type CagA and termed it Africa1-CM. The less toxicity of this motif could be one reason to explain the African enigma.

Análise da Segurança e Exequibilidade do Ecocardiograma sob Estresse com Dobutamina em Dez Mil e Seis Exames de uma População Geral / Analysis of the Safety and Feasibility of Dobutamine Stress Echocardiography in Ten Thousand and Six Tests of a General Population

Fundamento: Durante o ecocardiograma sob estresse com dobutamina, podem ocorrer efeitos adversos e exames inconclusivos. Objetivo: Avaliar em uma grande população geral a segurança e a exequibilidade do ecocardiograma sob estresse com dobutamina. Métodos: Estudo de 10.006 ecocardiogramas sob estresse com dobutamina realizados no período de julho de 1996 a setembro de 2007. A dobutamina foi administrada em quatro estágios (10, 20, 30 e 40 µcg.kg-1.min-1) para pesquisa de isquemia miocárdica e iniciada com 5 µcg.kg- ¹.min-1 apenas na análise de viabilidade miocárdica. A atropina foi iniciada conforme os protocolos vigentes. Foram verificados dados clínicos, hemodinâmicos e efeitos adversos associados ao ecocardiograma sob estresse com dobutamina. Resultados: Durante os ecocardiogramas sob estresse com dobutamina, ocorreu angina típica (8,9%), pico hipertensivo (1,7%), ectopias ventriculares isoladas (31%), taquiarritmia supraventricular (1,89%), fibrilação atrial (0,76%) e taquicardia ventricular não sustentada (0,6%). Os efeitos adversos citados foram mais frequentes nos pacientes com ecocardiogramas sob estresse com dobutamina positivos para isquemia. A desaceleração sinusal paradoxal (0,16%) não ocorreu em ecocardiogramas sob estresse com dobutamina positivo. As três complicações graves ocorreram em ecocardiogramas sob estresse com dobutamina positivos para isquemia. Foram dois casos (0,02%) com fibrilação ventricular e um caso de síndrome coronariana aguda (0,01%). Não houve caso de taquicardia ventricular sustentada, ruptura cardíaca, assistolia ou óbito. Comparados aos exames concluídos, nos inconclusivos, os pacientes usaram menos atropina (81,5% versus 49,9%; p< 0,001) e mais betabloqueador (4,7% versus 19%; p< 0,001), apresentando mais pico hipertensivo (1,1% versus 14,2%; p = 0,0001) e taquicardia ventricular não sustentada (0,5% versus 2,2%; p< 0,001). Conclusão: O ecocardiograma sob estresse com dobutamina realizado de forma apropriada é seguro e apresenta elevada exequibilidade.

Background: Adverse effects and inconclusive results may occur on dobutamine stress echocardiography. Objective: To assess the safety and feasibility of dobutamine stress echocardiography in a large general population. Methods: A total of 10,006 dobutamine stress echocardiographies were performed between July 1996 and September 2007. Dobutamine was administered in four stages (10, 20, 30, and 40 µcg·kg-1·min-1) to research myocardial ischemia starting with 5 µcg·kg- ¹·min-1 to analyze myocardial viability. Atropine administration was initiated according to current protocols. Clinical, hemodynamic, and adverse effect data associated with dobutamine stress echocardiography findings were verified. Results: Typical angina (8.9%), hypertensive peak (1.7%), isolated ventricular ectopias (31%), supraventricular tachyarrhythmia (1.89%), atrial

Clostridioides difficile Toxin A-Induced Wnt/ß-Catenin Pathway Inhibition Is Mediated by Rac1 Glucosylation.

Clostridioides difficile toxin A (TcdA) has been shown to inhibit cellular Wnt signaling, the major driving force behind the proliferation of epithelial cells in colonic crypts, likely through the inhibition of ß-catenin nuclear translocation. Herein, we aimed to advance the understanding of this mechanism by replicating the findings in vivo and by investigating the specific role of Rac1, a member of the Rho GTPase family, on the inhibition of the Wnt-induced ß-catenin nuclear translocation triggered by TcdA. To investigate the effects of TcdA on the Wnt/ß-catenin pathway in vivo, we injected the ileal loops of C57BL/6 mice with TcdA [phosphate-buffered saline (PBS) as the control] to induce C. difficile disease-like ileitis. After 4 h post-injection, we obtained ileum tissue samples to assess Wnt signaling activation and cell proliferation through Western blotting, immunohistochemistry, and qPCR. To assess the role of Rac1 on Wnt signaling inhibition by TcdA, we transfected rat intestinal epithelial cells (IEC-6) with either a constitutively active Rac1 plasmid (pcDNA3-EGFP-Rac1-Q61L) or an empty vector, which served as the control. We incubated these cells with Wnt3a-conditioned medium (Wnt3a-CM) to induce Wnt/ß-catenin pathway activation, and then challenged the cells with TcdA. We assessed Wnt signaling activation in vitro with TOP/FOPflash luciferase assays, determined nuclear ß-catenin translocation by immunofluorescence, measured cyclin D1 protein expression by Western blotting, and quantified cell proliferation by Ki67 immunostaining. In vivo, TcdA decreased ß-catenin, cyclin D1, and cMYC expression and inhibited the translocation of ß-catenin into the nucleus in the ileum epithelial cells. In addition, TcdA suppressed cell proliferation and increased Wnt3a expression, but did not alter Rac1 gene expression in the ileum tissue. In vitro, constitutively active Rac1 prevented Wnt signaling inhibition by enabling the ß-catenin nuclear translocation that had been blocked by TcdA. Our results show that TcdA inhibits Wnt/ß-catenin pathway in vivo and demonstrate that this inhibition is likely caused by a Rac1-mediated mechanism.

Piperine suppresses the Wnt/ß-catenin pathway and has anti-cancer effects on colorectal cancer cells.

More than 94% of colorectal cancer cases have mutations in one or more Wnt/ß-catenin signaling pathway components. Inactivating mutations in APC or activating mutations in ß-catenin (CTNNB1) lead to signaling overactivation and subsequent intestinal hyperplasia. Numerous classes of medicines derived from synthetic or natural small molecules, including alkaloids, have benefited the treatment of different diseases, including cancer, Piperine is a true alkaloid, derived from lysine, responsible for the spicy taste of black pepper (Piper nigrum) and long pepper (Piper longum). Studies have shown that piperine has a wide range of pharmacological properties; however, piperine molecular mechanisms of action are still not fully understood. By using Wnt/ß-catenin pathway epistasis experiment we show that piperine inhibits the canonical Wnt pathway induced by overexpression of ß-catenin, ß-catenin S33A or dnTCF4 VP16, while also suppressing ß-catenin nuclear localization in HCT116 cell line. Additionally, piperine impairs cell proliferation and migration in HCT116, SW480 and DLD-1 colorectal tumor cell lines, while not affecting the non-tumoral cell line IEC-6. In summary, piperine inhibits the canonical Wnt signaling pathway and displays anti-cancer effects on colorectal cancer cell lines.

Depletion of Ric-8B leads to reduced mTORC2 activity.

mTOR, a serine/threonine protein kinase that is involved in a series of critical cellular processes, can be found in two functionally distinct complexes, mTORC1 and mTORC2. In contrast to mTORC1, little is known about the mechanisms that regulate mTORC2. Here we show that mTORC2 activity is reduced in mice with a hypomorphic mutation of the Ric-8B gene. Ric-8B is a highly conserved protein that acts as a non-canonical guanine nucleotide exchange factor (GEF) for heterotrimeric Gαs/olf type subunits. We found that Ric-8B hypomorph embryos are smaller than their wild type littermates, fail to close the neural tube in the cephalic region and die during mid-embryogenesis. Comparative transcriptome analysis revealed that signaling pathways involving GPCRs and G proteins are dysregulated in the Ric-8B mutant embryos. Interestingly, this analysis also revealed an unexpected impairment of the mTOR signaling pathway. Phosphorylation of Akt at Ser473 is downregulated in the Ric-8B mutant embryos, indicating a decreased activity of mTORC2. Knockdown of the endogenous Ric-8B gene in cultured cell lines leads to reduced phosphorylation levels of Akt (Ser473), further supporting the involvement of Ric-8B in mTORC2 activity. Our results reveal a crucial role for Ric-8B in development and provide novel insights into the signals that regulate mTORC2.

[Ingredients for an exotic dish: health and diet on the agenda of the first Amazonian Medical Congress (Belém, 1939)]. / Ingredientes de um prato exótico: saúde e alimentação em pauta no primeiro Congresso Médico Amazônico (Belém, 1939).

The context in which the first Amazonian Medical Congress was organized and held in Belém, Brazil, in August 1939, is presented. Within the tradition of scientific communication of its time, the event brought together some of the region's medical elites and also had nationally and internationally renowned guest participants, including Josué de Castro and Dante Costa. Taking the printed matter produced by the congress and news stories printed in the local press as its main sources, this study examines the accompanying debates on dietary deficiencies in the Amazon, observing academic and political understandings of the different aspects of the phenomenon for the region.

O artigo apresenta o contexto de organização e realização do primeiro Congresso Médico Amazônico, ocorrido na cidade de Belém, em agosto de 1939. Inserido na tradição da divulgação científica de seu tempo, o evento reuniu parte das elites médicas da região e contou com a participação de convidados reconhecidos nacional e internacionalmente, entre eles Josué de Castro e Dante Costa. Tendo como principais fontes os materiais impressos produzidos pelo congresso e as notícias veiculadas nos jornais paraenses, este texto examina a concentração de debates sobre as carências alimentares da Amazônia observando a compreensão acadêmica e política das faces do fenômeno para a região.