Analysis of the pathway of developing a national mental health plan for Suriname

ABSTRACT: The aim of this analysis was to analyze and describe the steps that have been taken in the development of the mental health policy in Suriname after the WHO AIMS. The objectives are: 1.To review the steps to be taken in developing a mental health policy and plan for a country 2.To gather information and data concerning mental health policy and plan development in Suriname 3.To draw conclusion from the experience gained that can be applied to other countries. In general, the information that was gathered from the four countries Guyana, Barbados, Trinidad & Tobago and Suriname, was compared with the WHO steps for developing a mental health policy and plan. Were these steps taken into consideration, when developing their mental health policy and plan? If not, what were the reasons why it did not happen? The checklist for evaluating a mental health plan was used in Suriname. This checklist assisted to see if the results of the recommendations given by the WHO AIMS to develop a effective and balanced mental health plan were taken into consideration. The mayor findings of the analysis are that Suriname as well as Guyana used the steps in developing their mental health policy and plan. Barbados and Trinidad & Tobago did not develop a mental health policy and plan. Suriname and Guyana have a mental health coordinating body at the Ministry of Health. Trinidad & Tobago as well as Barbados have a mental health focal person at the Ministry of Health of the respective countries. It can be concluded that successfully improving of health systems and services for mental health is combining theoretical concepts, expert knowledge and cooperation of many stakeholders. The appointment of a mental health coordinating unit at the Ministry of Health is crucial for the development of mental health in a country. Furthermore, mental health is everyone’s business and responsibility. Implementing the steps to be taken when developing a mental health policy and plan as recommended by WHO may be a slow process requiring the mobilization of political will. That’s why it is crucial that persons responsible for this process work close with all stakeholders in relevant sectors, taking their needs into consideration and try to translate that in clear objectives. It is common knowledge that improving the quality of mental health must be accompanied by the availability of financial and human resources. Finally, a mental health policy and plan should be one document tackling all aspects of mental health of a community.

New spectroscopic and electrochemical insights on a class I superoxide reductase: evidence for an intramolecular electron-transfer pathway

Biochem. J. (2011) 438,485–494 doi:10.1042/BJ20110836

O2/CO2-sensitive cyclic AMP-signalling pathway in peripheral chemoreceptors

RESUMO: O corpo carotídeo (CB) é um pequeno órgão sensível a variações na PaO2, PaCO2 e pH. As células tipo I (células glómicas) do corpo carotídeo, as unidades sensoriais deste órgão, libertam neurotransmissores em resposta às variações dos gases arteriais. Estes neurotransmissores atuam quer em recetores pré-sinápticos, localizados nas células tipo I, quer em recetores póssinápticos, localizados nas terminações do nervo do seio carotídeo, ou em ambos. A activação dos recetores pré-sinápticos modula a atividade do corpo carotídeo, enquanto que, a activação dos recetores pós-sinápticos, de carater excitatório, desencadeia um aumento da frequência de descarga das fibras do CSN, com subsequente despolarização dos neurónios do gânglio petroso, e posterior despolarização de um grupo específico de neurónios do centro respiratório central, desencadeando, como resposta final, hiperventilação. Estes recetores pré- e pós-sinápticos podem ser classificados em ionotrópicos ou metabotrópicos, estando os últimos acoplados a adenilatos ciclases transmembranares (tmAC). O mecanismo exato pelo qual as variações dos gases arteriais são detetadas pelo CB não se encontra ainda completamente elucidado, mas tem sido sugerido que alterações nos níveis de cAMP estejam associadas ao mecanismo de deteção de variações de O2 e CO2. Os níveis de cAMP podem ser regulados através da sua via de síntese, mediada por dois tipos de adenilatos ciclases: tmAC sensível aos eurotransmissores e adenilato ciclase solúvel (sAC)sensível a variações de HCO3/CO2, e pela sua via de degradação mediada por fosfodiesterases. A via de degradação do cAMP pode ser manipulada farmacologicamente, funcionando enquanto alvo terapêutico para o tratamento de patologias do foro respiratório (e.g. asma, hipertensão pulmonar, doença pulmonar obstructiva crónica e apneia do sono), que induzem um aumento da actividade do CB.O trabalho descrito nesta dissertação partiu da hipótese de que a actividade do CB é manipulada por fármacos, que interferem com a via de sinalização do cAMP, tendo sido nosso objectivo geral, investigar o papel do cAMP na quimiotransdução do CB de rato, e determinar se a actividade dos enzimas responsáveis pela via de sinalização do cAMP é ou não regulada por variações de O2/CO2. Assim, a relevância deste trabalho é a de estudar e identificar possíveis alvos moleculares (sAC, isoformas de tmAC e PDE) com potencial para serem usados no tratamento de patologias relacionadas com o controlo respiratório. A primeira parte do presente trabalho, centrou-se na caracterização farmacológica da PDE4 no CB e em tecidos não quimiorecetores (e.g. gânglio cervical superior e artérias carótidas), e na observação do efeito de hipóxia aguda na acumulação dos níveis de cAMP, induzidos pelos inibidores de PDE, nestes tecidos. A quantificação de cAMP foi efectuada por técnica imunoenzimática (EIA), tendo sido elaboradas curvas de dose-resposta para os efeitos de inibidores, não específicos (IBMX) e específicos para a PDE2 e PDE4 (EHNA, Rolipram e Ro 20-1724), nos níveis de cAMP acumulados, em situações de normóxia (20%O2/5%CO2) e hipóxia (5%O2/5%CO2). A caracterização das PDE no gânglio cervical superior foi aprofundada, utilizando-se a técnica de transferência de energia de ressonância por fluorescência (FRET) em culturas primárias de neurónios, na presença de inibidores não específicos (IBMX) e específicos para a PDE3 e PDE4 (milrinone e rolipram, respetivamente). Foram igualmente estudadas, através de RT-qPCR, as alterações na expressão de PDE3A-B e PDE4A-D, no gânglio cervical superior, em resposta a diferentes percentagens de oxigénio. Na segunda parte do trabalho investigou-se a via de síntese do cAMP no CB em resposta a variações na concentração de HCO3/CO2. Em concreto, o protocolo experimental centrou-se na caracterização da sAC, dado que a sua actividade é regulada por variações de HCO3/CO2. A caracterização da expressão e regulação da sAC, em resposta a variações de HCO3/CO2 ,foi efectuada no CB e em tecidos não quimioreceptores periféricos (e.g. gânglio cervical superior, petroso e nodoso) por qRT-PCR. A actividade deste enzima foi caracterizada indirectamente através da quantificação dos níveis de cAMP (quantificação por EIA), induzidos por diferentes concentrações de HCO3/CO2, na presença de MDL-12,33-A, um inibidore da tmAC. A expressão das isoformas da tmAC no CB e gânglio petroso foi determinada por RT-qPCR. Adicionalmente, estudámos a contribuição relativa da tmAC e sAC no mecanismo de sensibilidade ao CO2 no CB. Para o efeito foram estudadas as alterações: 1) nos níveis de cAMP (quantificado por EIA) na presença de diferentes concentrações de HCO3/CO2 e ao longo do tempo (5-30 min); 2) na ativação da proteína cinase A (PKA, FRET baseado em sensores) em células tipo I do CB; e 3) na frequência de descarga do CSN (registos) na presença e ausência de ativadores e inibidores da sAC,tmAC e PKA. Por último, foi caracterizada a expressão e actividade da sAC nos quimioreceptors centrais (locus ceruleus, rafe e medula ventro-lateral) através de técnicas de RT-qPCR e EIA. A expressão das isoformas da tmAC foi aprofundada no locus coeruleus através de RT-qPCR. Por fim, comparámos a contribuição da tmAC e sAC nos níveis de cAMP no locus coeruleus em condições de normocapnia e hipercapnia.O nosso trabalho teve os seguintes resultados principais: 1) PDE4 está funcional no corpo carotídeo, artérias carótidas e gânglio cervical superior de rato, embora a PDE2 só se encontre funcional neste último; 2) Os efeitos dos inibidores de PDE nos níveis de acumulação de cAMP foram exacerbados em situações de hipóxia aguda no CB e artérias carótidas, mas foram atenuados no gânglio cervical superior; 3) No gânglio cervical superior, diferentes tipos de células apresentaram uma caracterização específica de PDEs, sugerindo uma subpopulação de células neste gânglio com funções fisiológicas distintas; 4) Embora todas as isoformas de PDE4 e PDE3 estivessem presentes no gânglio, a PDE3a, PDE4b e a PDE4d foram as isoformas mais expressas. Por outro lado, incubações de gânglio cervical superior, em diferentes percentagens de oxigénio, não alteraram (não regularam) significativamente a expressão das diferentes isoformas de PDE neste órgão; 5) a sAC encontra-se expressa e funcional no CB e nos quimiorecetores centrais estudados (locus coeruleus, rafe e medula ventrolateral). A sAC apresenta maior expressão no CB comparativamente aos restantes orgãos estudados, exceptuando os testículos, orgão controlo. Variações de HCO3/CO2 de 0/0 para 24/5 aumentaram os níveis de cAMP no CB e quimiorecetores centrais, tendo sido o aumento mais significativo observado no CB. Concentrações acima dos 24mM HCO3/5%CO2 não induziram alterações nos níveis de cAMP, sugerindo que a actividade da sAC se encontra saturada em condições fisiológicas (normocapnia) e que este enzima não desempenha qualquer papel na deteção de situações de hipercapnia; 6) No CB, a expressão das isoformas tmAC1, tmAC4, tmAC6 e tmAC9 é mais elevada comparativamente à expressão da sAC; 7) Utilizamos diferentes inibidores da tmAC (MDL 12-330A, 500μM, 2’5’-ddADO, 30-300μM, SQ 22536, 200μM) e da sAC (KH7, 10-100μM) para estudar a contribuição relativa destes enzimas na acumulação do cAMP no CB. Tanto a tmAC como a sAC contribuem para a acumulação dos níveis de cAMP em condições de hipercapnia. Contudo, existe um maior efeito destes inibidores nas condições de 12 mM HCO3/2.5%CO2 do que em condições de normocapnia e hipercapnia, sugerindo um papel relevante destes enzimas na atividade do CB em situações de hipocapnia; 8) Não se observaram variações nos níveis de cAMP em resposta a diferentes concentrações de HCO3/CO2 ao longo do tempo (5-30 min). O efeito inibitório induzido por ddADO e KH7 foi sobreponível após 5 ou 30 minutos de incubação em todas as concentrações de HCO3/CO2 estudadas; 9) Por último, verificou-se um aumento na frequência da descarga do nervo do seio carotídeo entre as condições de normocapnia e hipercapnia acídica. Ao contrário do KH7 (10μM), o 2’5’-ddADO reduziu significativamente a frequência de descarga do nervo, quer em condições de normocapnia quer de hipercapnia acídica. Contudo, não se verificou aumento na frequência de descarga do nervo entre normocapnia e hipercapnia isohídrica, sugerindo que a sensibilidade à hipercapnia no CB é mediada por variações de pH. Em conclusão, os resultados decorrentes deste trabalho permitiram demonstrar que, embora os enzimas que medeiam a via de sinalização do cAMP possam ser bons alvos terapêuticos em condições particulares, a sua actividade não é específica para o CB. Os resultados sugerem ainda que o cAMP não é um mediador específico da transdução à hipercapnia neste orgão. Contudo, os nossos resultados demonstraram que os níveis de cAMP são mais elevados em condições fisiológicas, o que sugere que o cAMP possa ter uma função homeostática neste orgão. Por último, o presente trabalho demonstrou que os aumentos de cAMP descritos por outros em condições de hipercapnia, não são observáveis quando o pH se encontra controlado. ------------------ ABSTRACT: The work presented in this dissertation was aimed to establish how specific is cAMP-signaling pathways in the CB mainly in different CO2 conditions and how O2 concentrations alter/drives the manipulation of cAMP signaling in the CB. The experimental studies included in this thesis sought to investigate the role of cAMP in the rat CB chemotransduction mechanisms and to determine whether the enzymes that participate in cAMP signal transduction in the CB are regulated by O2/CO2. We characterized the enzymes involved in the cAMP-signaling pathway in the CB (sAC, tmAC, PDE) under different O2/CO2 conditions. Our results demonstrated that many of these enzymes are involved in CO2/O2 sensing and while they may be useful in treating conditions with alterations in CO2/O2 sensing,they will not be specific to chemoreception within the CB: 1) PDE4 is ubiquitously expressed in CB and non-chemoreceptor related tissues and their affinity to inhibitors change with O2 tensions in both CB and carotid arteries, and 2) sAC and tmAC are expressed in peripheral and central chemo- and non-chemoreceptor tissues and their effect on cAMP levels do not change between normocapnic and isohydric hypercapnic conditions. Our results provide evidence against a specific role of cAMP as a mediator for O2 and CO2 chemotransduction in the rat CB and emphasized the role of pH in CO2 sensitivity of the CB. Furthermore, our results demonstrate that cAMP levels are maintained higher under physiological conditions, supporting recent finding from our lab, which all together suggests that cAMP has a homeostatic function in this organ.

A systems biology framework for pathway level culture media engineering: pplication to Pichia pastoris cultures

Dissertação para obtenção do Grau de Doutor em Engenharia Química e Bioquímica

Gene Expression Profiling and Association Studies Implicate the Neuregulin Signaling Pathway in Behçet's Disease Susceptibility

Behçet's disease (BD) is a complex disease with genetic and environmental risk factors implicated in its etiology; however, its pathophysiology is poorly understood. To decipher BD's genetic underpinnings, we combined gene expression profiling with pathway analysis and association studies. We compared the gene expression profiles in peripheral blood mononuclear cells (PBMCs) of 15 patients and 14 matched controls using Affymetrix microarrays and found that the neuregulin signaling pathway was over-represented among the differentially expressed genes. The Epiregulin (EREG), Amphiregulin (AREG), and Neuregulin-1 (NRG1) genes of this pathway stand out as they are also among the top differentially expressed genes. Twelve haplotype tagging SNPs at the EREG-AREG locus and 15 SNPs in NRG1 found associated in at least one published BD genome-wide association study were tested for association with BD in a dataset of 976 Iranian patients and 839 controls. We found a novel association with BD for the rs6845297 SNP located downstream of EREG, and replicated three associations at NRG1 (rs4489285, rs383632, and rs1462891). Multifactor dimensionality reduction analysis indicated the existence of epistatic interactions between EREG and NRG1 variants. EREG-AREG and NRG1, which are members of the epidermal growth factor (EGF) family, seem to modulate BD susceptibility through main effects and gene–gene interactions. These association findings support a role for the EGF/ErbB signaling pathway inBD pathogenesis that warrants further investigation and highlight the importance of combining genetic and genomic approaches to dissect the genetic architecture of complex diseases.

Transthyretin Amyloidosis: Chaperone Concentration Changes and Increased Proteolysis in the Pathway to Disease

Transthyretin amyloidosis is a conformational pathology characterized by the extracellular formation of amyloid deposits and the progressive impairment of the peripheral nervous system. Point mutations in this tetrameric plasma protein decrease its stability and are linked to disease onset and progression. Since non-mutated transthyretin also forms amyloid in systemic senile amyloidosis and some mutation bearers are asymptomatic throughout their lives, non-genetic factors must also be involved in transthyretin amyloidosis. We discovered, using a differential proteomics approach, that extracellular chaperones such as fibrinogen, clusterin, haptoglobin, alpha-1-anti-trypsin and 2-macroglobulin are overrepresented in transthyretin amyloidosis. Our data shows that a complex network of extracellular chaperones are over represented in human plasma and we speculate that they act synergistically to cope with amyloid prone proteins. Proteostasis may thus be as important as point mutations in transthyretin amyloidosis.

Adult B-Cell Acute Lymphoblastic Leukemia Cells Display Decreased PTEN Activity and Constitutive Hyperactivation of PI3K/Akt Pathway Despite High PTEN Protein Levels

Adult B-cell acute lymphoblastic leukemia remains a major therapeutic challenge, requiring a better characterization of the molecular determinants underlying disease progression and resistance to treatment. Here, using a phospho-flow cytometry approach we show that adult diagnostic B-cell acute lymphoblastic leukemia specimens display PI3K/Akt pathway hyperactivation, irrespective of their BCR-ABL status and despite paradoxically high basal expression of PTEN, the major negative regulator of the pathway. Protein kinase CK2 is known to phosphorylate PTEN thereby driving PTEN protein stabilization and concomitant PTEN functional inactivation. In agreement, we found that adult B-cell acute lymphoblastic leukemia samples show significantly higher CK2 kinase activity and lower PTEN lipid phosphatase activity than healthy controls. Moreover, the clinical-grade CK2 inhibitor CX-4945 (Silmitasertib) reversed PTEN levels in leukemia cells to those observed in healthy controls, and promoted leukemia cell death without significantly affecting normal bone marrow cells. Our studies indicate that CK2-mediated PTEN posttranslational inactivation, associated with PI3K/Akt pathway hyperactivation, are a common event in adult B-cell acute lymphoblastic leukemia and suggest that CK2 inhibition may constitute a valid, novel therapeutic tool in this malignancy.

Gold nanoprobes for assessing expression of critical genes in the infection pathway of MRSA

Staphylococcus aureus is an important opportunistic pathogen that can cause a wide variety of diseases from mild to life-threatening conditions. S. aureus can colonize many parts of the human body but the anterior nares are the primary ecological niche. Its clinical importance is due to its ability to resist almost all classes of antibiotics available together with its large number of virulence factores. MRSA (Methicillin-Resistant S. aureus) strains are particularly important in the hospital settings, being the major cause of nosocomial infections worldwide. MRSA resistance to β-lactam antibiotics involves the acquisition of the exogenous mecA gene, part of the SCCmec cassette. Fast and reliable diagnostic techniques are needed to reduce the mortality and morbidity associated with MRSA infections, through the early identification of MRSA strains. The current identification techniques are time-consuming as they usually involves culturing steps, taking up to five days to determine the antibiotic resistance profile. Several amplification-based techniques have been developed to accelerate the diagnosis. The aim of this project was to develop an even faster methodology that bypasses the DNA amplification step. Gold-nanoprobes were developed and used to detect the presence of mecA gene in S. aureus genome, associated with resistance traits, for colorimetric assays based on non-crosslinking method. Our results showed that the mecA and mecA_V2 gold-nanoprobes were sensitive enough to discriminate the presence of mecA gene in PCR products and genomic DNA (gDNA) samples for target concentrations of 10 ng/μL and 20 ng/μL, respectively. As our main objective was to avoid the amplification step, we concluded that the best strategy for the early identification of MRSA infection relies on colorimetric assays based on non-crosslinking method with gDNA samples that can be extracted directly from blood samples.

Family relationship and parenting practices: a pathway to adolesents’ collectivist and individualist values?

Adolescents’ perceptions of parenting and family relationships are important variables for identifying mechanisms involved in how children acquire values and how these values are transmitted through families. In a sample of 515 adolescents, we investigated whether perceptions of the quality of parental practices would predict adolescents’ collectivist and individualist values. We hypothesized that perceived quality of family relations would mediate the relationship between the quality of parental practices and collectivist values but not of individualist values. The results of structural equation modeling suggested that perception of the quality of parental practices predicted adolescents’ both collectivist and individualist values. The predicted mediation effect was found for collectivist values, but not for individualist values. The results point to different functions of parenting and family relations on value acquisition. Implications for practice, such as the development and implementation of interventions to improve the formation of adolescents’ values by enhancing the quality of parenting and family relationships are discussed.

NF-kB pathway controls mitochondrial dynamics

The Optic atrophy 1 protein (OPA1) is a key element in the dynamics and morphology of mitochondria. We demonstrated that the absence of I?B kinase-a, which is a key element of the nonclassical NF-?B pathway, has an impact on the mitochondrial network morphology and OPA1 expression. In contrast, the absence of NF-?B essential modulator (NEMO) or I?B kinase-ß, both of which are essential for the canonical NF-?B pathway, has no impact on mitochondrial dynamics. Whereas Parkin has been reported to positively regulate the expression of OPA1 through NEMO, herein we found that PARK2 overexpression did not modify the expression of OPA1. PARK2 expression reduced the levels of Bax, and it prevented stress-induced cell death only in Bak-deficient mouse embryonic fibroblast cells. Collectively, our results point out a role of the nonclassical NF-?B pathway in the regulation of mitochondrial dynamics and OPA1 expression.

Inactivation of PNKP by mutant ATXN3 triggers apoptosis by activating the DNA damage-response pathway in SCA3.

Spinocerebellar ataxia type 3 (SCA3), also known as Machado-Joseph disease (MJD), is an untreatable autosomal dominant neurodegenerative disease, and the most common such inherited ataxia worldwide. The mutation in SCA3 is the expansion of a polymorphic CAG tri-nucleotide repeat sequence in the C-terminal coding region of the ATXN3 gene at chromosomal locus 14q32.1. The mutant ATXN3 protein encoding expanded glutamine (polyQ) sequences interacts with multiple proteins in vivo, and is deposited as aggregates in the SCA3 brain. A large body of literature suggests that the loss of function of the native ATNX3-interacting proteins that are deposited in the polyQ aggregates contributes to cellular toxicity, systemic neurodegeneration and the pathogenic mechanism in SCA3. Nonetheless, a significant understanding of the disease etiology of SCA3, the molecular mechanism by which the polyQ expansions in the mutant ATXN3 induce neurodegeneration in SCA3 has remained elusive. In the present study, we show that the essential DNA strand break repair enzyme PNKP (polynucleotide kinase 3'-phosphatase) interacts with, and is inactivated by, the mutant ATXN3, resulting in inefficient DNA repair, persistent accumulation of DNA damage/strand breaks, and subsequent chronic activation of the DNA damage-response ataxia telangiectasia-mutated (ATM) signaling pathway in SCA3. We report that persistent accumulation of DNA damage/strand breaks and chronic activation of the serine/threonine kinase ATM and the downstream p53 and protein kinase C-d pro-apoptotic pathways trigger neuronal dysfunction and eventually neuronal death in SCA3. Either PNKP overexpression or pharmacological inhibition of ATM dramatically blocked mutant ATXN3-mediated cell death. Discovery of the mechanism by which mutant ATXN3 induces DNA damage and amplifies the pro-death signaling pathways provides a molecular basis for neurodegeneration due to PNKP inactivation in SCA3, and for the first time offers a possible approach to treatment.

Block of the Mitral-pulmonary Isthmus During Ablation of a Single Left-sided Accessory Pathway Causing Different Patterns of Retrograde Atrial Activation

The case of a 16-year-old patient with atrioventricular tachycardia caused by a single left anterolateral accessory pathway is reported. When the patient underwent radiofrequency ablation, a lesion on the mitral annulus lateral wall produced changes in the retrograde atrial activation pattern determined by that pathway; changes ranged from a delay in depolarization of the annulus posterior portions to full left atrium counterclockwise activation. Such phenomena were probably caused by a block in the isthmus between the annulus and the lower left pulmonary vein ostium. This case illustrates the importance of the mitral-pulmonary isthmus in the process of left atrium activation, an alert to changes induced by its unintentional block during accessory pathway ablation.

Estudio de los mecanismos moleculares involucrados en la inmunosupresión observada durante la infección con Trypanosoma cruzi: Rol de la vía PD-1/PD1-L y E3 ubiquitina ligasas. Molecular mechanismns involved in the immunosupression during Tryapanosoma cruzi infection. Role of PD1-PD1-L pathway and E3 ubiquitin ligases.

Trypanosoma cruzi es el agente causal de la enfermedad de Chagas, un problema de salud importante en América Latina, así como también en América Central, ya que causa infección crónica afectando a millones de personas [1]. Durante esta enfermedad se han descripto varias alteraciones de la respuesta inmune, entre ellas una severa inmunosupresión durante la etapa aguda de la infección, tanto en humanos como en ratones. Células T provenientes de ratones infectados activadas in vitro, muestran reducción en la respuesta proliferativa a mitógenos, característica de un estado de inmunosupresión [2-4]. La falla del sistema inmune durante estadios tempranos de la infección probablemente colabore con la diseminación y el establecimiento del parásito. Un gran número de estudios se han focalizado en la identificación de mecanismos moleculares responsables del fenómeno de inmunosupresión, entre los mecanismos citados se ha demostrado presencia de células supresoras [5-9], factores inmunosupresores presentes en el parásito [2, 3, 10-13], producción excesiva de óxido nítrico [14], disminuida producción de IL-2 y reducida expresión del receptor de IL2 en células de bazo de animales infectados [9, 15-17]. Muchos de estos mecanismos han sido exhaustivamente investigados, sin embargo no está del todo claro si existen mecanismos adicionales involucrados en la inmunosupresión de la célula T. Adicionalmente, en los últimos años nuevas moléculas que median la regulación negativa de la célula T, entre las cuales están PD-1/PD1-L [18], arginasa [19] y E3 ubiquitina ligasas [20-22], han sido reportadas durante inmunosupresión en diversas infecciones. Trypanosoma cruzi, the etiological agent of Chagas’ disease, is parasite causing chronic infections in human and other mammalian species. There is an important immunosupresion during the acute phase of the infection that contribute to the dissemination and installation of the parasite. Several studies have been focused on identifying the mechanisms involved in the immunosupresion; however it is not clear if there are additional mechanisms implicated. In addition, during the last years new molecules involved in the negative T cell regulation such as PD-1/PD1-L pathway and E3 ubiquitin ligases (E3-Ub-Lig) have been reported. It has been demonstrated, that E3-Ub-Lig control the amount and localization of intracellular signal mediators, limiting T cell activation. Moreover, these mechanisms mediate the immunosupresion observed during several infections leading to the persistence of the pathogen in the host. In this project the role of E3-Ub-Lig on the T cell immunosupresion and hipo-response mechanisms observed during T. cruzi infection will be studied. On the other hand, it has been reported that some pathogens release proteins with E3-Ub-Lig activity modifying the ubiquitination process to promote their survival and replication in the host. Recently, a protein with E3-Ub-Lig activity was identified in T. cruzi, however its target molecule has not been discovered yet. Therefore, one of the aims of this project consists on studying different potential target molecules for this novel E3-Ub-Lig. In addition, during the last years, important progress has been done about the biological rol of PD-1/PD1-L pathway on the regulation of the immune response in several infections. However, it is not well known how PD-1/PD1-L pathway transduces signals at intracelular level to block T cell response. Because of this, it is interesting to study if there is any relation between the PD-1/PD1-L pathway and E3-Ub-Lig on the mechanism of T cell immunosupression during T. cruzi infection.

Obesity Preserves Myocardial Function During Blockade of the Glycolytic Pathway

Background: Obesity is defined by excessive accumulation of body fat relative to lean tissue. Studies during the last few years indicate that cardiac function in obese animals may be preserved, increased or diminished. Objective: Study the energy balance of the myocardium with the hypothesis that the increase in fatty acid oxidation and reduced glucose leads to cardiac dysfunction in obesity. Methods: 30-day-old male Wistar rats were fed standard and hypercaloric diet for 30 weeks. Cardiac function and morphology were assessed. In this paper was viewed the general characteristics and comorbities associated to obesity. The structure cardiac was determined by weights of the heart and left ventricle (LV). Myocardial function was evaluated by studying isolated papillary muscles from the LV, under the baseline condition and after inotropic and lusitropic maneuvers: myocardial stiffness; postrest contraction; increase in extracellular Ca2+ concentration; change in heart rate and inhibitor of glycolytic pathway. Results: Compared with control group, the obese rats had increased body fat and co-morbities associated with obesity. Functional assessment after blocking iodoacetate shows no difference in the linear regression of DT, however, the RT showed a statistically significant difference in behavior between the control and the obese group, most notable being the slope in group C. Conclusion: The energy imbalance on obesity did not cause cardiac dysfunction. On the contrary, the prioritization of fatty acids utilization provides protection to cardiac muscle during the inhibition of glycolysis, suggesting that this pathway is fewer used by obese cardiac muscle.