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A encefalopatia hepática (EH) se refere a um espectro de alterações neuropsiquiátricas, usualmente reversíveis, apresentadas por pacientes portadores de disfunção hepática crônica ou aguda, com manifestações clínicas bastante variadas, desde acometimento sutil até o desenvolvimento de complicações graves com risco de morte. Os achados mais comuns na ressonância magnética encefálica são lesões de hipersinal nas ponderações em T1 e T2, bilaterais e simétricas nos globos pálidos, putâmens, regiões subtalâmicas, substância negra e adeno-hipófise. Certas entidades apresentam achados neurorradiológicos típicos, como na EH, que podem orientar o diagnóstico precoce e preciso, o que torna o papel do neurorradiologista fundamental nessa detecção.

La atención médica integral representa el instrumento metodológico más efectivo para mejorar de manera constante la calidad de vida e incremento de los cuidados de los pacientes afectados con enfermedades hepáticas. Esta política sanitaria, responde a un método sistematizado y organizado dirigido a brindar cuidados, a través de la valoración, diagnóstico, planificación, intervención y evaluación de acuerdo a las respuestas humanas de la persona, utilizando el método científico como sustento de las acciones, lo que permite abordar un plan de cuidados, según sea la patología y gravedad del enfermo, considerándose para ello que, los pacientes con enfermedad hepática (enfermedades del hígado), crónicas, encontrándose entre ellas, la hepatitis A, B y C, Hígado Graso, Enfermedades Autoinmunes y la Cirrosis; esta última caracterizada por tener mayor riesgo de readmisión hospitalaria, hallándose una mortalidad de 13% a los 90 días, y que las causas más comunes de esta afección médica en países desarrollados son la hepatitis viral crónica tanto B o C, hepatopatía alcohólica, hemocromatosis y hepatopatía no alcohólica, menos comunes son la hepatitis autoinmune, cirrosis biliar primaria y secundaria, colangitis esclerosante primaria, medicación como metotrexate e isoniazida, enfermedad de Wilson, deficiencia de alfa-1 antitripsina, padecimientos éstos que por su condición clínica, deben ser tratados bajo orientaciones médicas dirigidas por los diferentes programas y políticas en salud, los cuales tienen como propósito garantizar a las poblaciones (en este caso pacientes con enfermedades hepáticas) la continuidad de los cuidados garantizando sobre bases científicas, tanto la evaluación, como la aplicación del tratamiento adecuado; de ahí, la importancia que tienen estos servicios de atención sanitaria, los cuales buscan brindar a los pacientes con insuficiencia hepática crónica un diagnóstico oportuno y la identificación de factores precipitantes, lográndose de esa forma, mejorar el estado clínico de la persona.

Aim: analyze the motor precision of cirrhotic patients with or without hepatic encephalopathy (HE), in different severities, through the geospatial capture of the hands. Methodology: The target audience was patients at the Gastroenterology Service of a tertiary hospital in Northeastern Brazil. Data were collected from three groups of patients (A, unidentified EH; B, grade I EH and; C, grade II EH). Motricity data collection was performed with the Leap Motion Controller (LMC). The collected data were composed by the position of 16 points of the hands in three dimensions that, in sequence, were converted into distance between two points. Results: 60 patients with a mean age of 54.6 (± 14.7) years were included. The Kruskal-Wallis and Dunn tests indicated differences in the medians of the variables for the three groups (p < 0.05). The graphical representations show a difference in motor precision between the groups in an index of 100% of the variables, with variations with a tendency of C > B > A in 87.5% of the cases. The frequency of movement of the fingers, of both hands, had the potential to differentiate the groups. Direction is more discriminating than position and speed. Conclusion: The results suggest the possibility of differentiating the classes of patients and that the progression of motor deviation is one of the complications of the worsening of the disease. Objetivo: analizar la precisión motora de pacientes cirróticos con o sin encefalopatía hepática (EH), en diferentes severidades, a través de la captura geoespacial de las manos. Metodología: El público objetivo fueron los pacientes del Servicio de Gastroenterología de un hospital terciario del Nordeste de Brasil. Se recogieron datos de tres grupos de pacientes (A, EH no identificado; B, EH grado I y; C, EH grado II). La recolección de datos de motricidad se realizó con el Leap Motion Controller (LMC). Los datos recolectados fueron compuestos por la posición de 16 puntos de las manos en tres dimensiones que, en secuencia, se convirtieron en distancia entre dos puntos. Resultados: se incluyeron 60 pacientes con una edad media de 54,6 (± 14,7) años. Las pruebas de Kruskal-Wallis y Dunn indicaron diferencias en las medianas de las variables para los tres grupos (p B> A en el 87,5% de los casos. La frecuencia de movimiento de los dedos, de ambas manos, tenía el potencial de diferenciar los grupos. La dirección discrimina más que la posición y la velocidad. Conclusión: Los resultados sugieren la posibilidad de diferenciar las clases de pacientes y que la progresión de la desviación motora es una de las complicaciones del agravamiento de la enfermedad. Objetivo: analisar a precisão motora de pacientes cirróticos com ou sem encefalopatia hepática (EH), em diferentes gravidades, por meio da captura geoespacial das mãos. Metodologia: O público-alvo foram os pacientes do Serviço de Gastroenterologia de um hospital terciário do Nordeste do Brasil. Os dados foram coletados em três grupos de pacientes (A, EH não identificado; B, EH grau I e; C, EH grau II). A coleta dos dados de motricidade foi realizada com o Leap Motion Controller (LMC). Os dados coletados foram compostos pela posição de 16 pontos das mãos em três dimensões que, em sequência, foram convertidas em distância entre dois pontos. Resultados: Foram incluídos 60 pacientes com idade média de 54,6 (± 14,7) anos. Os testes de Kruskal-Wallis e Dunn indicaram diferenças nas medianas das variáveis ​​para os três grupos (p B > A em 87,5% dos casos. As frequências de movimento dos dedos, de ambas as mãos, tiveram o potencial de diferenciar os grupos. A direção é mais discriminativa do que a posição e a velocidade. Conclusão: Os resultados sugerem a possibilidade de diferenciar as classes de pacientes e que a progressão do desvio motor é uma das complicações do agravamento da doença.

RESUMEN El trastorno por consumo de alcohol es una de las principales causas de morbimortalidad en el mundo. La enfermedad hepática alcohólica es una complicación común de este trastorno y la encefalopatía hepática es una seria comorbilidad de la cirrosis alcohólica. Los factores precipitantes pueden relacionarse con infección, sangrado gastrointestinal, deshidratación o efectos de psicofármacos (p. ej., benzodiacepinas e hipnóticos no benzodiacepínicos). Se expone un caso del manejo hospitalario de un paciente con un trastorno severo por consumo de alcohol, cirrosis y encefalopatía hepática, quien desarrolla síntomas de abstinencia alcohólica durante su hospitalización y la complejidad del manejo antagónico de un delirium gabaérgico propio de la encefalopatía hepática en el contexto de un delirium glutamatérgico-noradrenérgico por abstinencia alcohólica. ABSTRACT Alcohol use disorder is one of the main causes of morbidity and mortality in the world. Alcoholic liver disease is a common complication of this disorder, and hepatic encephalopathy is a serious complication of alcoholic cirrhosis. Precipitating factors may be related to infection, gastrointestinal bleeding, dehydration or the effects of psychotropic drugs (e.g. benzodiazepines and non-benzodiazepine hypnotics). We present a case of the hospital management of a patient with a severe alcohol use disorder, cirrhosis and hepatic encephalopathy who developed alcohol withdrawal symptoms while in hospital, and discuss the complexity of the antagonistic management of a GABAergic delirium characteristic of hepatic encephalopathy in the context of a glutamatergic-noradrenergic delirium due to alcohol withdrawal.

Highlights • First documented simultaneous bilateral dual mobility THA dislocation. • Myoclonus due to hepatic encephalopathy are a risk factor for dislocation. • Dual mobility cups provide lower rates of dislocation. • Meticulous history and examination are mandatory when faced with hip instability. • Prevention of dislocation is preferable to treating this challenging complication., Introduction and importance Dislocation is a severe complication after total hip arthroplasty (THA). It is one of the most common reasons for failure and revision surgery. This is the first case of a documented simultaneous bilateral dual mobility (DM) THA dislocation. Case presentation A forty-nine-year-old man presented with bilateral hip pain, immobility and deformity. X-ray images demonstrated simultaneous bilateral posterior THA dislocation. Previously, the patient had presented atraumatic dislocations recurrently. When he was thoroughly re-interrogated, he complained of uncontrolled and generalized muscle contractions, which were compatible with myoclonus due to hepatic encephalopathy (HE). Multidisciplinary treatment was performed satisfactorily to control myoclonus symptomatology and to prevent dislocation. Clinical discussion Patient’s most important risk factor was a neuromuscular disorder, which we initially gave little notice and undervalued. HE is a serious but reversible syndrome, observed in patients with liver dysfunction. It leads to a wide spectrum of neuropsychiatric abnormalities. Management is based on prevention of episodes, avoiding the underlying triggers. Due to the high risk for dislocation of our patient, we decided to use DM cups bilaterally. This system has demonstrated lower rates of dislocation. Conclusion This case report reminds us that a careful evaluation through meticulous history and physical examination are mandatory when faced with recurrent instability. Furthermore, prevention of dislocation is vastly preferable to treating this challenging complication. High-risk patients should be identified, and appropriate surgical approach, technique and implants have to be collectively used to reach a strategy that mitigates and ideally prevents dislocation.

No therapies have been proven to increase survival after a hepatic encephalopathy (HE) episode. We hypothesize that two doses of albumin could improve 90-day survival rates after a HE episode. Methods: (1) A randomized double-blind, placebo-controlled trial (BETA) was conducted in 12 hospitals. The effect of albumin (1.5 g/kg at baseline and 1 g/kg on day 3) on 90-day survival rates after a HE episode grade II or higher was evaluated. (2) A meta-analysis of individual patient’s data for survival including two clinical trials (BETA and ALFAE) was performed. Results: In total, 82 patients were included. Albumin failed to increase the 90-day transplant-free survival (91.9% vs. 80.5%, p = 0.3). A competing risk analysis was performed, observing a 90-day cumulative incidence of death of 9% in the albumin group vs. 20% in the placebo (p = 0.1). The meta-analysis showed a benefit in the albumin group, with a lower rate of clinical events (death or liver transplant) than patients in the placebo (HR, 0.44, 95% CI, 0.21–0.82), when analyzed by a competing risk analysis (90-days mortality rate of 11% in the albumin group vs. 30% in the placebo, p = 0.02). Conclusions: Repeated doses of albumin might be beneficial for patient’s survival as an add-on therapy after an HE episode, but an adequately powered trial is needed.

Treballs Finals de Grau d'Enginyeria Biomèdica. Facultat de Medicina i Ciències de la Salut. Universitat de Barcelona. Curs: 2020-2021. Directora: Anna Baiges. Tutor: Mario García., Hepatic encephalopathy (HE) is a pathology believed to be produced when the liver function is impaired and cannot adequately remove toxins from the blood, such as ammonia, which leads to a buildup of toxins in the bloodstream that can reach the brain and affect its function. Some patients that present cirrhosis may be eligible to have a TIPS (Transjugular Intrahepatic Portosystemic Shunt) implanted, which decreases the pressure in the portal vein and improves their liver condition. However, clinical evidences have shown that HE is more likely to appear in patients that have had a TIPS implanted. This work is a first stage of a project that aims to create a device able to predict the development of HE on patients that have an implanted TIPS and also study the causes of this pathology. Since ammonium is the only proven biomarker for HE, an initial study was performed to discuss which other ions or molecules could have a correlation with the development of HE. Additionally, since there is a correlation between the ammonium concentration in blood and sweat, a non-invasive sensor that measures the ammonium concentration in sweat was conceptualized and designed. Because this device is non-invasive, could be worn in daily life and it allows a simple maintenance that does not require a technician, it would present an advantage over the current diagnostic techniques since they are invasive or mainly based on psychological tests.

BACKGROUND: Covert hepatic encephalopathy (CHE) is difficult to detect due to the lack of easily applicable screening tools. The Stroop EncephalApp is a smartphone application already validated for CHE screening. However, its applicability to the Brazilian population is not known. OBJECTIVE: To estimate the prevalence of CHE and evaluate the use of Stroop EncephalApp in a cirrhotic population in Brazil. METHODS: In this cross-sectional study, we evaluated 99 patients previously diagnosed with liver cirrhosis in a Private Hospital in Curitiba/PR. Patients were initially submitted to the mini mental state examination (MMSE) to exclude individuals with dementia. After, the Psychometric Hepatic Encephalopathy Score (PHES) test was performed and lastly, the Stroop EncephalApp test. Results were adjusted for age, sex and education levels to evaluate the accuracy of the app on detecting the disease, comparing its results with the gold standard method (PHES). Patients with one or more of the following were excluded: dementia, inadequate MMSE score, illiteracy, color blindness, history of drugs/alcohol abuse within the past 3 months and previous or actual episodes of encephalopathy. The statistical analysis was performed by SPSS 2.0 and the significance adopted by 5%. RESULTS: We included 82 individuals in the final analysis. Among these patients, 29 were diagnosed with CHE by the PHES test (35.36% prevalence) and 28 of those obtained equal diagnosis by the Stroop EncephalApp (96.6% sensitivity). A total of 53 patients obtained negative results for CHE by PHES, while the Stroop test classified 27 of them as having the disease. In the multivariate analysis, high levels of education were associated with better performance during the tests. No significant relationship was observed between age and sex with the probability of diagnosing CHE through the PHES test. RESUMO CONTEXTO: A encefalopatia hepática mínima (EHM) é uma complicação neuro-psiquiátrica da cirrose cuja detecção é dificultada pela falta de ferramentas práticas. O Stroop EncephalApp é um aplicativo de smartphones capaz de detectar a doença, entretanto sua aplicabilidade na população brasileira ainda não é conhecida. OBJETIVO: Avaliar o uso do Stroop EncephalApp para diagnóstico e avaliação de EHM em uma população de pacientes cirróticos no Brasil. MÉTODOS: Através de um estudo observacional transversal, 99 indivíduos sabidamente cirróticos foram recrutados do ambulatório de hepatologia de um hospital privado em Curitiba/PR. Primeiramente, foram aplicados o mini exame do estado mental (MEEM) para excluir indivíduos com demência; após, foram aplicados o Escore Psicométrico da Encefalopatia Hepática (PHES), atual padrão-ouro para diagnóstico de EHM, e posteriormente o Stroop EncephalApp, ajustando para idade, sexo e anos de formação acadêmica, buscando avaliar a eficiência do aplicativo em detectar a doença e comparar seus resultados com o atual padrão-ouro. Foram excluídos do estudo indivíduos com demência, pontuação insuficiente no MEEM, analfabetos, daltônicos, e com histórico de abuso de álcool/drogas ilícitas nos últimos 3 meses e paciente com episódios prévios ou atuais de encefalopatia hepática. A análise estatística foi realizada pelo SPSS 2.0 e a significância adotada em 5%. RESULTADOS: Um total de 82 indivíduos foram incluídos na análise final. Destes, 29 foram diagnosticados com EHM (35,36% de prevalência) através do PHES e 28 obtiveram o mesmo resultado após a aplicação do Stroop (96,6% de sensibilidade). Cinquenta e três pacientes obtiveram um resultado negativo para EHM através do PHES, sendo que 27 desses obtiveram um resultado positivo para EHM através do Stroop. Na análise multivariada, níveis elevados de escolaridade estiveram associados com melhor desempenho durante a execução dos testes. Não houve associação significativa entre idade e sexo com a probabilidade de apresentar encefalopatia através do PHES. CONCLUSÃO: O Stroop EncephalApp é uma ferramenta viável e com boa sensibilidade para o screening de EHM, mas possui baixa especificidade na população estudada.

La encefalopatía hepática (EH) es un síndrome neuropsiquiátrico complejo consecuencia de un fallo hepático. Alrededor del 40% de los pacientes cirróticos sin síntomas clínicos evidentes de EH presenta encefalopatía hepática mínima (EHM), con déficits cognitivos y enlentecimiento psicomotor. La hiperamonemia y la inflamación periférica actúan sinérgicamente induciendo neuroinflamación, que altera la neurotransmisión conduciendo al deterioro de la función cognitiva y motora. Los pacientes con esteatohepatitis pueden presentar deterioro cognitivo leve si los niveles de hiperamonemia e inflamación son lo suficientemente elevados. Además, en cerebelo de estos pacientes se ha encontrado infiltración de linfocitos T y neuroinflamación. Estos datos sugieren que la aparición de la EHM puede ocurrir en etapas tempranas del daño hepático, antes de llegar a cirrosis. El objetivo de esta tesis fue analizar, en un modelo de rata con fallo hepático progresivo: a) las alteraciones cognitivas y motoras que se producen como consecuencia del daño hepático, cuándo aparecen y cómo evolucionan con el grado de fallo hepático, b) las alteraciones en la neurotransmisión en cerebelo e hipocampo asociadas a las diferentes alteraciones cognitivas y motoras, c) la neuroinflamación y los mecanismos por los que la inflamación periférica conduce a la neuroinflamación, d) los cambios en el sistema inmune asociados al daño hepático y e) los efectos del tratamiento con rifaximina y los mecanismos por los cuales puede mejorar las alteraciones cognitivas y motoras. Los resultados muestran que la incoordinación motora aparece ya en el estadio de esteatohepatitis, y está asociada a alteraciones de la neurotransmisión GABAérgica inducidas por la neuroinflamación en cerebelo. Las alteraciones cognitivas evolucionan con el grado de daño hepático: en esteatohepatitis se deterioran el aprendizaje y la memoria espaciales, mientras que la memoria de trabajo solo se deteriora en esteatohepatitis avanzada y la memoria de reconocimiento de un objeto nuevo en ratas con cirrosis. Estas alteraciones se asocian a neuroinflamación en hipocampo que induce alteraciones en la neurotransmisión glutamatérgica y GABAérgica. El daño hepático induce inflamación periférica y cambios en el inmunofenotipo, que evolucionan con el grado de daño hepático y promueven la infiltración de linfocitos T y macrófagos en cerebelo e hipocampo, lo que contribuye al mantenimiento de la neuroinflamación. El tratamiento con rifaximina de ratas con daño hepático crónico previene muchas de las alteraciones en el sistema inmune periférico y la infiltración de células del sistema inmune en el cerebro, lo cual disminuye la neuroinflamación y previene o revierte las alteraciones en la neurotransmisión. Esto conduce a la mejora de la función cognitiva y motora. Estos resultados indican que el tratamiento temprano con rifaximina podría prevenir el deterioro neurológico en pacientes con esteatohepatitis. Hepatic encephalopathy (HE) is a complex neuropsychiatric syndrome resulting from liver failure. About 40% of cirrhotic patients without evident clinical symptoms of HE show minimal hepatic encephalopathy (MHE), with cognitive deficits and psychomotor slowing. Hyperammonemia and peripheral inflammation act synergistically to induce neuroinflammation, which alters neurotransmission, impairing cognitive and motor function. Patients with steatohepatitis may show mild cognitive impairment if hyperammonemia and inflammation are high enough. Moreover, infiltration of T lymphocytes and neuroinflammation have been reported in cerebellum of these patients. These data suggest that the appearance of MHE may occur at early stages of liver damage, before reaching cirrhosis. The objective of this thesis was to analyze in a rat model of progressive liver failure: a) cognitive and motor alterations that occur as a consequence of liver damage, when they appear and how they progress with the progression of liver failure, b) alterations in neurotransmission in cerebellum and hippocampus associated with the different cognitive and motor alterations, c) neuroinflammation and the mechanisms by which peripheral inflammation leads to neuroinflammation, d) changes in the immune system associated with progression of liver damage and e) the effects of treatment with rifaximin and the mechanisms by which it can improve cognitive and motor function. The results show that motor incoordination appears already at steatohepatitis, and it is associated with impaired GABAergic neurotransmission induced by neuroinflammation in cerebellum. Cognitive impairments evolve with the grade of liver damage: spatial learning and memory are impaired in steatohepatitis, while working memory only deteriorates in advanced steatohepatitis and object recognition memory in rats with cirrhosis. These alterations are associated with neuroinflammation in hippocampus, which induces alterations in glutamatergic and GABAergic neurotransmission. Liver damage induces peripheral inflammation and changes in the immunophenotype, which evolve with the progression of liver damage and promote the infiltration of T lymphocytes and macrophages in cerebellum and hippocampus, which contributes to promotion and maintenance of neuroinflammation. Treatment with rifaximin of rats with chronic liver damage prevents many of the alterations in the peripheral immune system and the infiltration of immune system cells into the brain. This decreases neuroinflammation and prevents or restores changes in neurotransmission. This leads to improvement of cognitive and motor function. These results suggest that early treatment with rifaximin could prevent neurological impairment in patients with steatohepatitis.

[EN] Hepatic encephalopathy (HE) is a neuropsychiatric disorder derived from liver failure, which exhibits symptoms such as motor impairment, personality or mood changes, and even coma in advanced stages. HE cases are classified in 3 types depending on the severity of the symptoms, and are usually preceded by a less acute stage, known as minimal hepatic encephalopathy (MHE). Although many of the patients presenting MHE are not diagnosed due to its relatively mild symptoms (attention deficit, psychomotor slowing¿), it has been proved by numerous studies that this disease severely impacts their quality of life, and their ability to perform in everyday tasks. Liver failure induces HE through two synergistic ways: firstly, liver¿s inability to eliminate toxic substances such as ammonia, derives in the accumulation of these substances in the body (i.e. hyperammonemia). This accumulation can be observed in peripheral tissues as well as in the central nervous system (CNS), and has the potential to affect the activity of this last one. Secondly, liver failure gives rise to peripheral inflammation, which in turn leads to neuroinflammation. This neuroinflammation derives in altered neurotransmission, which causes cognitive and motor impairment. This laboratory has intensely studied this disorder for years, and is currently using a chronic liver disease model based on administration of carbon tetrachloride (CCl4) in rats. The periodic administration of this hepatic toxin to the rodents derives in a chronic progressive liver failure, which goes through all the stages described in humans: steatosis, steatohepatitis and cirrhosis. Furthermore, it shows similar symptoms to HE, including MHE. Exosomes have been known for years to have the potential to develop into a useful drug delivery mechanism: they are shed and reabsorbed by many cell types, delivering functional molecules to the recipient cell, such as proteins, mRNAs and miRNAs. They are especially promising when it comes to treating brain diseases, as they have no problem crossing the brain-blood barrier. This project focuses on the study of the use of MSCs-derived exosomes as a treatment for neuroinflammation and related cognitive and motor alterations in CCl4-induced MHE. Therefore, this work consisted on the evaluation of glial activation (in the cerebellum and hippocampus), the study of membrane expression of neurotransmitter receptor subunits (in the hippocampus), and measuring learning ability and motor impairment. All these studies were performed on 4 groups of rats receiving different treatments: CV (control vehicle), CEX (control + exosome treatment), CC (receiving CCl4) and CCEX (receiving both CCl4 injections and exosome treatment) in order to ascertain the possible activity of exosomes in preventing neuroinflammation. Results, although not always significant due to the low amount of animals studied, did show an interesting tendency of CCEX group values to differ from those of CC groups, in some cases tending towards normalization. This tendency was present in a more obvious way in glial activation and behavior tests, which revealed the most favorable results for rat groups receiving exosomes. However, as mentioned, symptomatology of HE depends on the interplay of several factors, so further studies should be performed in order to clarify how these effects take place and how they should be employed in order to achieve satisfactory results in the treatment of MHE., [ES] La encefalopatía hepática (EH) es un trastorno neuropsiquiátrico derivado del fallo hepático, el cual exhibe síntomas tales como problemas de movilidad, cambios de humor y personalidad, e incluso coma en etapas avanzadas. La EH está precedida normalmente por una etapa menos severa, conocida como encefalopatía hepática mínima (EHM). A pesar de que muchos pacientes con EHM no son diagnosticados debido a sus síntomas relativamente suaves (déficit de atención, lentitud psico-motora¿), ha sido probado por numerosos estudios que esta enfermedad afecta a su calidad de vida, así como a su habilidad para llevar a cabo tareas del día a día. El fallo hepático induce esta enfermedad por dos vías que actúan de forma sinérgica: en primer lugar, la incapacidad del hígado para eliminar sustancias tóxicas (siendo ésta una de sus principales funciones) como el amonio, causa la acumulación de dichas toxinas en el cuerpo (hiperamonemia en este caso). Ésta es observable tanto en los tejidos periféricos como en el sistema nervioso central (SNC), y es capaz de afectar a las funciones de éste último por sí sola. En segundo lugar, el fallo hepático acarrea inflamación periférica, la cual produce neuroinflamación, que altera la neurotransmisión y es así la principal causante de los trastornos cognitivos y motores. Este laboratorio ha estudiado extensamente esta enfermedad durante años. Actualmente está utilizando para ello un modelo de daño hepático crónico por administración de tetracloruro de carbono (CCl4) en ratas. La administración crónica de esta hepatotoxina en roedores causa un fallo hepático crónico progresivo, pasando por las diferentes etapas (esteatosis, esteatohepatitis y cirrosis) y presenta importantes similitudes con algunos síntomas de la EH, incluyendo la EHM. Los exosomas son conocidos desde hace años como una opción prometedora en el campo de la administración dirigida de medicamentos. Esto es debido a que su producción y reabsorción es llevada a cabo por numerosos tipos celulares en el cuerpo, donde liberan moléculas funcionales tales como proteínas, mRNAs y miRNAs. Son especialmente prometedores en lo que respecta al tratamiento de trastornos cerebrales, ya que puede cruzar la barrera hematoencefálica fácilmente, uno de los mayores obstáculos para la administración de medicamentos a este órgano. Este proyecto consiste en el estudio del uso de exosomas derivados de células madre mesenquimales humanas como tratamiento para reducir la neuroinflamación y las alteraciones cognitivas y motoras en este modelo animal. Así pues, este trabajo ha consistido en la medida de activación glial (en el cerebelo y el hipocampo), el estudio de la expresión en membrana de subunidades de receptores de neurotransmisores (en el hipocampo), y la evaluación de la memoria espacial y habilidad motora. Todos los experimentos se llevaron a cabo sobre 4 grupos de ratas: CV (control), CEX (control recibiendo tratamiento con exosomas), CC (grupo que recibe CCl4), CCEX (grupo que recibe CCl4 y exosomas), con el objetivo de aclarar la posible capacidad de los exosomas para prevenir la neuroinflamación. Los resultados, aunque no siempre significativos debido al bajo número de animales utilizados, si mostraron una tendencia del grupo CCEX a modificar sus valores con respecto a CC, en algunos casos para acercarlos más a los de CV. Esta tendencia estuvo presente de forma más obvia en la activación glial y los tests de comportamiento, que reflejaron resultados más favorables a los grupos tratados con exosomas. Sin embargo, otros estudios en profundidad serán necesarios para comprender cómo llevan a cabo su acción los exosomas exactamente, y por tanto cómo deberían ser empleados para obtener los mejores resultados en el tratamiento de la EHM.

Introdução: Insuficiência Hepática Aguda (IHA) é uma síndrome rara, porém potencialmente fatal e que ocorre em pacientes vítimas de uma perda rápida e extensa da função hepática. Além diminuição da capacidade de síntese (clinicamente expressa como INR > 1.5), a IHA leva ao surgimento de Encefalopatia Hepática (EH). A EH consiste no surgimento de distúrbios neurológicos secundários ao acúmulo de toxinas no sangue e cérebro de pacientes com doença hepática. A fisiopatologia da EH é multifatorial, envolvendo o acúmulo de amônia, a excitotoxicidade glutamatérgica, as alterações de bioenergética cerebral, dano à barreira hematoencefálica (BHE), entre outros. A modulação do sistema glutamatérgico vem sendo testada com sucesso para o controle dos sintomas da EH, em especial com o uso da Guanosina (GUO). Objetivos: i) estudar os efeitos da EH no metabolismo energético cerebral e na BHE, com foco no metabolismo de aminoácidos e ii) testar os efeitos neuroprotetores da GUO em um modelo animal de IHA. Métodos: utilizou-se modelo animal de IHA induzida por hepatectomia subtotal (remoção de 92% da massa hepática). Em uma coorte de animais, amostras de líquido cefalorraquidiano (LCR) e córtex cerebral foram colhidos 24 horas após a cirurgia para ensaios bioquímicos. Em um segundo grupo, a administração de guanosina foi testada por via intraperitoneal (i.p.) por 60 horas após a cirurgia para avaliar o desempenho neurológico e, sobretudo, a mortalidade dos animais hepatectomizados. Resultados: animais com EH apresentaram diversas alterações bioenergéticas como i) aumento do consumo de oxigênio mitocondrial; ii) aumento da atividade enzimática do ciclo de Krebs e produção de ATP; iii) aumento da oxidação de glutamato; e iv) diminuição da oxidação de glicose e lactato. Paralelamente, aumento de parâmetros de estresse oxidativo e reação astrocitária difusa em imagens de imuno-histoquímica foram encontrados no córtex parietal de animais com IHA. Em relação à BHE, animais com EH apresentaram níveis elevados de albumina e de amino ácidos no LCR. O aumento de amino ácidos no LCR foi relacionado ao grau de declínio neurológico e se apresentou como um biomarcador para identificar animais com prognóstico desfavorável. A administração de GUO foi capaz reduzir a mortalidade e melhorar parâmetros neurológicos e comportamentais. A GUO também reduziu os níveis de albumina no LCR, aumentou a captação de glutamato pelos astrócitos e reverteu as alterações histológicas provocadas pela reatividade astrocitária. Discussão: animais com IHA apresentaram intensa resposta celular astrocitária com aumento de volume celular, alterações no metabolismo energético cerebral, aumento de estresse oxidativo e aumento de albumina e amino ácidos no LCR, sugestivos de danos à BHE. O uso de GUO foi capaz de reverter muitos dos parâmetros avaliados, além de trazer claro benefício na mortalidade dos animais tratados. Os resultados apresentados nesta tese esclarecem aspectos da fisiopatologia da EH e reforçam os potenciais efeitos neuroprotetores do uso da GUO no contexto da IHA. Introduction: Acute Liver Failure (ALF) is a rare medical condition that occurs in patients with rapid and extensive loss of hepatic function, presenting high mortality rates. It is characterized by the reduction of the liver’s synthetic capacity and the development of Hepatic Encephalopathy (HE). HE consists of a spectrum of neurological symptoms caused by the accumulation of toxins in blood and brain of patients with liver disease. HE’s physiopathology is complex, multifactorial and involves ammonia accumulation, glutamatergic excitotoxicity, brain bioenergetic alterations and increased blood brain barrier (BBB) permeability. Modulation of the glutamatergic system is being tested with success to treat this condition, especially using the nucleoside Guanosine (GUO). Objectives: i) to study the effects of HE on brain bioenergetics and BBB permeability, with emphasis in amino acid metabolism; ii) to test the neuroprotective effects of GUO. Methods: the studies were performed using an animal model of ALF induced by subtotal hepatectomy (removal of 92% of the hepatic mass). Samples of cerebrospinal fluid (CSF) and cerebral cortex were harvested 24 hours after surgery for biochemical essays. A second cohort of animal had GUO administered via intraperitoneal (i.p.) injection for 60 hours after surgery to study the neurological performance and mortality of the animals. Results: animals with HE presented several bioenergetic alterations such as i) increased mitochondrial oxygen consumption; ii) increased TCA enzyme activity and ATP production; iii) increased glutamate oxidation; iv) decreased glucose and lactate oxidation. HE also increased free reactive oxygen species, which were associated with a diffuse astrocytic reactivity evidenced by immunohistochemical images of parietal cortex. Regarding BBB permeability, animals with HE presented increased levels of albumin and amino acids in the CSF, which were associated to the severity of encephalopathy. Elevated CSF amino acids also accurately predicted the mortality prognosis. The administration of GUO was able to reduce ALF’s mortality and to improve neurological and behavioral function. GUO also improved biochemical parameters, as it normalized albumin levels in the CSF, increased glutamate uptake and prevented glial reactivity. Discussion: ALF induced a significant astrocytic reactivity with cellular expansion, which was associated with alterations in brain energy metabolism, increased oxidative stress and increased levels of albumin and amino acids in the CSF (suggesting increased BBB permeability). The administration of GUO prevented most of the evaluated biochemical parameters and presented a clear benefit by reducing mortality and improving neurological function of treated animals. The results of these studies bring new evidence for the understanding of HE’s physiopathology and strengthen the potential neuroprotective effects of GUO under ALF.

Acute liver failure (ALF) implies a severe and rapid liver dysfunction that leads to impaired liver metabolism and hepatic encephalopathy (HE). Recent studies have suggested that several brain alterations such as astrocytic dysfunction and energy metabolism impairment may synergistically interact, playing a role in the development of HE. The purpose of the present study is to investigate early alterations in redox status, energy metabolism and astrocytic reactivity of rats submitted to ALF. Adult male Wistar rats were submitted either to subtotal hepatectomy (92% of liver mass) or sham operation to induce ALF. Twenty-four hours after the surgery, animals with ALF presented higher plasmatic levels of ammonia, lactate, ALT and AST and lower levels of glucose than the animals in the sham group. Animals with ALF presented several astrocytic morphological alterations indicating astrocytic reactivity. The ALF group also presented higher mitochondrial oxygen consumption, higher enzymatic activity and higher ATP levels in the brain (frontoparietal cortex). Moreover, ALF induced an increase in glutamate oxidation concomitant with a decrease in glucose and lactate oxidation. The increase in brain energy metabolism caused by astrocytic reactivity resulted in augmented levels of reactive oxygen species (ROS) and Poly [ADP-ribose] polymerase 1 (PARP1) and a decreased activity of the enzymes superoxide dismutase and glutathione peroxidase (GSH-Px). These findings suggest that in the early stages of ALF the brain presents a hypermetabolic state, oxidative stress and astrocytic reactivity, which could be in part sustained by an increase in mitochondrial oxidation of glutamate.

[ES] El hígado es el principal órgano encargado de la detoxificación de sustancias tóxicas. La encefalopatía hepática (EH) es un síndrome neuropsiquiátrico complejo causado por una alteración en esta capacidad detoxificadora del hígado y puede presentarse en pacientes con enfermedades hepáticas crónicas o agudas. Una de las principales sustancias que se acumula en sangre y en cerebro es el amonio. La elevada concentración de amonio o hiperamonemia y la neuroinflamación actúan de forma sinérgica en la inducción de las alteraciones cognitivas y motoras presentes en EH. Los modelos animales de EH reproducen las alteraciones encontradas en pacientes. Recientemente, se ha descrito que la administración intracerebral de GMP cíclico (GMPc) extracelular en cerebelo in vivo restaura la coordinación motora reduciendo la neuroinflamación y la activación de microglía en ratas con hiperamonemia crónica. No obstante, el mecanismo por el que el GMPc extracelular modula la neuroinflamación no se conoce en detalle. En el presente trabajo se ha utilizado un modelo experimental de cortes de cerebelo ex vivo para profundizar en el estudio de los mecanismos moleculares implicados en la modulación de la neuroinflamación por el GMPc extracelular. Se ha utilizado el modelo animal de hiperamonemia crónica, obtenido mediante una dieta rica en amonio. Los objetivos concretos de este trabajo han sido: (1) Analizar la activación de la microglía en condiciones basales, (2) Relacionar esta activación con uno de los fenotipos de la microglía, (3) Estudiar la vía de señalización de activación microglial CCL2, P2X4, pp38 MAPK y BDNF, (4) Analizar el efecto del GMPc extracelular sobre la activación de microglía y si está mediado por la inhibición del receptor de glicina, (5) Analizar la localización de CCL2 y BDNF en neuronas de Purkinje y microglía en condiciones basales y tras el tratamiento con GMPc extracelular, (6) Estudiar si el efecto del GMPc extracelular sobre la vía de señalización de activación microglial podría estar mediado a través del receptor de TNF alfa. Los resultados obtenidos muestran que: (1) La hiperamonemia crónica induce activación de la microglía y se revierte con el tratamiento de GMPc extracelular, reproduciendo las condiciones del modelo in vivo, y del inhibidor del receptor de glicina; (2) En cortes de cerebelos ex vivo de ratas hiperamonémicas la microglía presenta un fenotipo antiinflamatorio M2b. El GMPc extracelular y el inhibidor del receptor de glicina revierten el fenotipo de microglía a un estadío M0 (no activación); (3) La hiperamonemia crónica induce activación de microglía a través de la vía de señalización mediada por CCL2, P2X4, pp38 MAPK, BDNF. El GMPc extracelular y el inhibidor del receptor de glicina reducen la activación de la microglía modulando a CCL2 y BDNF; (4) CCL2 y BDNF se localizan en neuronas de Purkinje y el GMPc extracelular disminuye la expresión de CCL2 y normaliza BDNF en hiperamonemia crónica, ambas co-localizan en microglía; (5) CCL2 aumenta su expresión en células gliales y el GMPc extracelular lo normaliza; (6) La modulación de la expresión de CCL2 y BDNF por el GMPc extracelular está mediada a través del receptor de TNF alfa (TNFR1)., [EN] El hígado es el principal órgano encargado de la detoxificación de sustancias tóxicas. La encefalopatía hepática (EH) es un síndrome neuropsiquiátrico complejo causado por una alteración en esta capacidad detoxificadora del hígado y puede presentarse en pacientes con enfermedades hepáticas crónicas o agudas. Una de las principales sustancias que se acumula en sangre y en cerebro es el amonio. La elevada concentración de amonio o hiperamonemia y la neuroinflamación actúan de forma sinérgica en la inducción de las alteraciones cognitivas y motoras presentes en EH. Los modelos animales de EH reproducen las alteraciones encontradas en pacientes. Recientemente, se ha descrito que la administración intracerebral de GMP cíclico (GMPc) extracelular en cerebelo in vivo restaura la coordinación motora reduciendo la neuroinflamación y la activación de microglía en ratas con hiperamonemia crónica. No obstante, el mecanismo por el que el GMPc extracelular modula la neuroinflamación no se conoce en detalle. En el presente trabajo se ha utilizado un modelo experimental de cortes de cerebelo ex vivo para profundizar en el estudio de los mecanismos moleculares implicados en la modulación de la neuroinflamación por el GMPc extracelular. Se ha utilizado el modelo animal de hiperamonemia crónica, obtenido mediante una dieta rica en amonio. Los objetivos concretos de este trabajo han sido: (1) Analizar la activación de la microglía en condiciones basales, (2) Relacionar esta activación con uno de los fenotipos de la microglía, (3) Estudiar la vía de señalización de activación microglial CCL2, P2X4, pp38 MAPK y BDNF, (4) Analizar el efecto del GMPc extracelular sobre la activación de microglía y si está mediado por la inhibición del receptor de glicina, (5) Analizar la localización de CCL2 y BDNF en neuronas de Purkinje y microglía en condiciones basales y tras el tratamiento con GMPc extracelular, (6) Estudiar si el efecto del GMPc extracelular sobre la vía de señalización de activación microglial podría estar mediado a través del receptor de TNF alfa. Los resultados obtenidos muestran que: (1) La hiperamonemia crónica induce activación de la microglía y se revierte con el tratamiento de GMPc extracelular, reproduciendo las condiciones del modelo in vivo, y del inhibidor del receptor de glicina; (2) En cortes de cerebelos ex vivo de ratas hiperamonémicas la microglía presenta un fenotipo antiinflamatorio M2b. El GMPc extracelular y el inhibidor del receptor de glicina revierten el fenotipo de microglía a un estadío M0 (no activación); (3) La hiperamonemia crónica induce activación de microglía a través de la vía de señalización mediada por CCL2, P2X4, pp38 MAPK, BDNF. El GMPc extracelular y el inhibidor del receptor de glicina reducen la activación de la microglía modulando a CCL2 y BDNF; (4) CCL2 y BDNF se localizan en neuronas de Purkinje y el GMPc extracelular disminuye la expresión de CCL2 y normaliza BDNF en hiperamonemia crónica, ambas co-localizan en microglía; (5) CCL2 aumenta su expresión en células gliales y el GMPc extracelular lo normaliza; (6) La modulación de la expresión de CCL2 y BDNF por el GMPc extracelular está mediada a través del receptor de TNF alfa (TNFR1).

FAPEMIG - Fundação de Amparo à Pesquisa do Estado de Minas Gerais A encefalopatia hepática (EH) é uma complicação neurológica que ocorre em consequência à doença hepática. Pacientes que sofrem com EH podem apresentar sintomas neuropsiquiátricos, neuromusculares e comportamentais, o que causa grande impacto na qualidade de vida e capacidade laborativa. Atualmente, o único tratamento definitivo para a falência hepática é o transplante, evidenciando assim a necessidade de desvendar a fisiopatologia e os mecanismos envolvidos na doença, a fim de encontrar novos focos terapêuticos e medidas suportivas até que o transplante esteja disponível. Modelos experimentais de EH em roedores têm sido amplamente utilizados. Acredita-se que estes modelos forneçam informzações relevantes para a compreensão dos mecanismos envolvidos na patogênese da doença, bem como possibilitem o desenvolvimento de novos alvos terapêuticos. Estudos que avaliam as sequelas neurológicas após o desenvolvimento da EH assim como sua associação com dados teciduais, perfis inflamatório e neuroquímico em fases mais tardias da doença são escassos. Por meio da utilização de camundongos C57BL/6, fêmeas, entre oite e doze semanas de idade, foram investigadas as alterações comportamentais e patológicas associadas às respostas inflamatória e neuroprotetora na EH induzida por falência hepática por injeção intraperitoneal de tioacetamida (TAA). Os camundongos foram divididos em grupos TAA e grupo controle, sendo esses últimos, submetidos à injeção intraperitoneal de salina. Os animais do grupo TAA apresentaram dano hepático associado a maior atividade dos neutrófilos e macrófagos. Além disso, os animais induzidos demonstraram através da aplicação de testes, comportamento semelhante à ansiedade e à depressão e alterações morfológicas dos astrócitos e da micróglia. Este mesmo grupo apresentou redução significativa da expressão das citocinas pró-inflamatórias interferon- (IFN-) e interleucina-6 (IL-6) no hipocampo e do fator neurotrófico derivado do cérebro (BNDF) no córtex cerebral, quando comparado com os animais do grupo controle. Nossos resultados sugerem que disfunções das respostas inflamatória e neuroprotetora estejam associadas à formação dos déficits comportamentais na EH murina. Hepatic encephalopathy (HE) is a neurological complication observed in hepatic failure. HE patients may present neuropsychiatric, neuromuscular, and behavioral disorders, which may impair quality of life and work capability. Currently, the only definitive treatment for hepatic failure is transplantation, which highlights the need for complete understanding of the pathophysiology and mechanisms involved in the disease, in order to establish new therapeutic targets and supportive measures until transplantation is available. Experimental models of HE in rodents have been widely used. It is believed that these models provide relevant information for understanding the mechanisms involved in the pathogenesis of the disease, as well as the development of new therapeutic targets. Studies evaluating neurological sequelae after the development of hepatic encephalopathy as well as its association with tissue data, inflammatory and neurochemical profiles in later stages of the disease are scarce. Using C57BL/6 female mice, between eight and twelve weeks age, we investigated behavioral and pathological changes association with inflammatory and neuroprotective responses during HE that follows hepatic failure induced by intraperitoneal injection of thioacetamide (TAA). Mice were divided into TAA and control groups, the latter being submitted to intraperitoneal injection of saline. TAA animals presented liver damage associated with increased activity of neutrophils and macrophages. In addition, induced animals demonstrated in the applied tests, anxiety-like and depression-like behavior and morphological changes of astrocytes and microglia. This same group showed a significant reduction in expression of proinflammatory cytokines interferon- (IFN-) and interleukin-6 (IL-6) in the hippocampus and the brain-derived neurotrophic factor (BNDF) in the cerebral cortex when compared to the control animals. Our results suggest that inflammatory and neuroprotective responses disorders are associated with behavioral deficits in murine hepatic encephalopathy.

Introducción: El diagnóstico de la encefalopatía hepática encubierta en pacientes con cirrosis hepática se encuentra en estado de cambio, fundamentalmente en lo que a las pruebas diagnósticas refiere. Objetivo: El objetivo de este estudio fue comparar los resultados diagnósticos de dos test, el Score Psicométrico para Encefalopatía Hepática y el Stroop EncephalApp en el diagnóstico de encefalopatía hepática encubierta. Materiales y métodos: Se aplicaron ambos test en pacientes cirróticos ambulatorios de la consulta de cirrosis hepática en el Hospital “Arnaldo Milián”, provincia de Villa Clara, comparando los resultados del EncephalApp tomando como prueba de referencia el Score Psicométrico para Encefalopatía Hepática. Las variables edad, sexo y escolaridad fueron ajustadas según normas poblacionales. Resultados: Un total de 80 cirróticos, así como 520 controles sanos fueron incluidos. Utilizando el Stroop EncephalApp el 35% de los cirróticos presentaban encefalopatía hepática encubierta, al utilizar el Score Psicométrico para Encefalopatía Hepática la presencia de encefalopatía hepática encubierta fue del 40%, mostrando el Stroop EncephalApp un 80% de sensibilidad y 82% de especificidad. Conclusiones: La encefalopatía hepática encubierta no diagnosticada muestra una elevada incidencia en cirróticos. El Score Psicométrico para Encefalopatía H adecuada sensibilidad en el diagnóstico de Encefalopatía hepática encubierta. Introduction: The early diagnosis of occult hepatic encephalopathy in patients with liver cirrhosis is currently a challenge, mainly with regard to diagnostic tests. Objetive: The aim of this study was to compare the results of two tests, the psychometric score for hepatic encephalopathy and the Stroop EncephalApp in the diagnosis of covert hepatic encephalopathy. Materials and methods: The two tests were applied in patients in the cirrhosis consultation of the "Arnaldo Milián" Hospital in Villa Clara, comparing the results of Stroop EncephalApp taking as reference the psychometric score for hepatic encephalopathy. The variables age, sex and schooling were adjusted according to population norms. Results: A total of 80 cirrhotic patients were included, as well as 520 healthy controls. Using the Stroop EncephalApp, 35% presented covert hepatic encephalopathy, when the Psychometric score for hepatic encephalopathy was used. The prevalence was 40%, showing the sensitivity of Stroop EncephalApp of 80% and 82% of specificity. Conclusions: undiagnosed occult hepatic encephalopathy shows a high prevalence in cirrhosis. The psychometric score for hepatic encephalopathy and Stroop EncephalApp show adequate sensitivity in the diagnosis of occult hepatic encephalopathy.