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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
11

Cerebral edema and acute liver failure : pathophysiological mechanisms and new therapeutic approaches

Jiang, Wenlei 03 1900 (has links)
L’encéphalopathie hépatique (EH) se développe chez les patients atteints d’une maladie du foie et se caractérise par de nombreuses anomalies neuropsychiatriques. L’insuffisance hépatique aiguë (IHA) se caractérise par une perte progressive de l’état de conscience, par une augmentation rapide de l’œdème cérébral et une augmentation de la pression intracrânienne entraînant une herniation cérébrale et la mort. Plusieurs facteurs sont responsables du développement de l’EH mais depuis une centaine d’années, l’hyperammonémie qui peut atteindre des concentrations de l’ordre de plusieurs millimolaires chez les patients atteints d’IHA aux stades de coma est considérée comme un facteur crucial dans la pathogenèse de l’EH. La présente thèse comprend 4 articles suggérant l’implication de nouveaux mécanismes pathogéniques dans le développement de l’EH et de l’œdème cérébral associés à l’IHA et tente d’expliquer l’effet thérapeutique de l’hypothermie et de la minocycline dans la prévention de l’EH et de l’œdème cérébral: 1. L’IHA induite par dévascularisation hépatique chez le rat se caractérise par une augmentation de la production de cytokines pro-inflammatoires cérébrales (IL-6, IL-1, TNF-). Cette observation constitue la première évidence directe que des mécanismes neuro-inflammatoires jouent une rôle dans la pathogenèse de l’EH et de l’œdème cérébral associés à l’IHA (Chapitre 2.1, articles 1 et 2). 2. L’activation de la microglie telle que mesurée par l’expression de marqueurs spécifiques (OX42, OX-6) coïncide avec le développement de l’encéphalopathie (stade coma) et de l’œdème cérébral et s’accompagne d’une production accrue de cytokines pro-inflammatoires cérébrales (Chapitre 2.1, article 1 et 2). 3. Un stress oxydatif/nitrosatif causé par une augmentation de l’expression de l’oxyde nitrique synthétase et une augmentation de la synthèse d’oxyde nitrique cérébral participe à la pathogénèse des complications neurologiques de l’IHA (Chapitre 2.3, articles 3 et 4). 4. Des traitements anti-inflammatoires tels que l’hypothermie et la minocycline peuvent constituer de nouvelles approches thérapeutiques chez les patients atteints d’IHA (Chapitre 2.1, article 1; Chapitre 2.2, article 2). 5. Les effets bénéfiques de l’hypothermie et de la minocycline sur les complications neurologiques de l’IHA expérimentale s’expliquent, en partie, par une diminution du stress oxydatif/nitrosatif (Chapitre 2.3, article 3; Chapitre 2.4, article 4). / Hepatic encephalopathy (HE) contains a spectrum of neuropsychiatric abnormalities observed in patients with liver disease. A quick worsening of consciousness and increasingly growing cerebral edema, high intracranial pressure, which leads to cerebral herniation and death, are characteristics of acute liver failure (ALF). Multiple factors are found responsible for the development of HE, whereas, over 100 years, hyperammonia is considered the most crucial factor in defining the pathogenesis of HE in ALF, which can increase to millimolar concentrations in the brain at the coma stages of HE. The present thesis comprises 4 articles, which demonstrates new pathogenic mechanisms involved in the development of HE and cerebral edema in ALF, and elucidates part of the therapeutic mechanism of hypothermia and minocycline in the prevention of HE and cerebral edema during ALF. The major findings are listed below: (1) Experimental ALF leads to the increase in brain production of proinflammatory cytokines (IL-6, IL-1, TNF-α), and provides the first direct evidence that central inflammatory mechanisms play a role in the pathogenesis of the encephalopathy and brain edema in ALF (chapter 2.1 - article 1; chapter 2.1 - article 2). (2) Activation of cerebral microglia, measured by OX-42, OX-6, predicts the presence of severe encephalopathy (coma) and brain edema in rats with ischemic ALF, which accompanies the increased production of brain proinflammatory cytokines (chapter 2.1 - article 1; chapter 2.2 - article 2). (3) Oxidative/nitrosative stress participates in the pathogenesis of brain edema and its complications in experimental ALF animals with ischemic liver failure. The increases in cerebral NOS isoform expression caused by ALF were sufficient to cause increased NO production in the brain (chapter 2.3 - article 3; chapter 2.4 - article 4). (4) Anti-inflammatory treatment, such as hypothermia or antibiotics, may be beneficial in patients with ALF (chapter 2.1 - article 1; chapter 2.2 - article 2). (5) The beneficial effect of both hypothermia and minocycline on the neurological complications of experimental ALF is mediated, at least in part, by reduction of brain-derived oxidative/nitrosative stress (chapter 2.3 - article 3; chapter 2.4 - article 4).
12

Die Serumkonzenztrationen von S-100B bei Leberzirrhose und transjugulärem intrahepatischen portosytemischen Stent-Shunt in Abhängigkeit von der minimalen hepatischen Enzephalopathie der Leber- und der Nierenfunktion / Serum concentrations of S100B in liver cirrhosis and transjugular intrahepatic portal-systemic stent-shunt in relation to minimal hepatic encephalopathy, liver and kidney function

Schumann-Binarsch, Silke 16 February 2015 (has links)
No description available.
13

Leucina versus isoleucina no tratamento da encefalopatia hepática: ensaio clínico randomizado e duplo-cego / Leucine versus Isoleucine for hepatic encephalopathy treatment: a double-blinded randomized trial

Franzoni, Letícia de Campos [UNESP] 17 February 2017 (has links)
Submitted by LETICIA DE CAMPOS FRANZONI null (leticiafranzoni@hotmail.com) on 2017-04-05T01:59:34Z No. of bitstreams: 1 Tese Doutorado Versao Final 13 jan 2017 - Franzoni.pdf: 1564703 bytes, checksum: 96d71fb57b63c2b888283c1b53168fd1 (MD5) / Approved for entry into archive by Luiz Galeffi (luizgaleffi@gmail.com) on 2017-04-12T17:18:02Z (GMT) No. of bitstreams: 1 franzoni_lc_dr_bot.pdf: 1564703 bytes, checksum: 96d71fb57b63c2b888283c1b53168fd1 (MD5) / Made available in DSpace on 2017-04-12T17:18:02Z (GMT). No. of bitstreams: 1 franzoni_lc_dr_bot.pdf: 1564703 bytes, checksum: 96d71fb57b63c2b888283c1b53168fd1 (MD5) Previous issue date: 2017-02-17 / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / Introdução: Os aminoácidos de cadeia ramificada (BCAA) são parte do tratamento da encefalopatia hepática (HE) e aumentam a perfusão cerebral. Como são compostos por três aminoácidos diferentes, as proporções de cada um variam nos ensaios clínicos, tornando difícil esclarecer qual substância está mais envolvida na perfusão cerebral e em outros parâmetros significativos. O objetivo deste estudo foi comparar os efeitos clínicos e de perfusão cerebral obtidos pela suplementação de leucina versus isoleucina para tratamento da HE. Métodos: Cinqüenta pacientes ambulatoriais com cirrose e HE foram randomizados para receber suplementos orais contendo 30 g de leucina ou isoleucina diariamente, por um ano. As avaliações clínicas e a avaliação nutricional foram realizadas bimestralmente. A Tomografia Computadorizada cerebral por emissão de fóton único (SPECT) e a cintilografia cerebral dinâmica foram realizadas pré-tratamento e em 1, 8 e 12 meses de suplementação. Vinte e sete indivíduos concluíram o estudo (16 com isoleucina e 11 com leucina). Resultados: O aumento da perfusão cerebral foi observado apenas no grupo isoleucina. O aumento foi documentado aos 8 meses de tratamento tanto pelo SPECT como pela cintilografia cerebral (p <0,001 e p = 0,05, respectivamente) e pelo SPECT no 12º mês (p <0,05). Foi associado a uma melhora significativa de HE em 8 e 12 meses neste grupo (p = 0,008 e 0,004, respectivamente), o que foi menos claro no grupo leucina (p = 0,313 e 0,055, respectivamente). Conclusões: A suplementação de isoleucina permitiu alcançar um melhor impacto nas manifestações de HE e na perfusão cerebral de pacientes com cirrose. Os resultados sugerem que pacientes com HE devem receber mais isoleucina do que leucina. / Introduction: Branched chain amino acids (BCAA) are part of hepatic encephalopathy (HE) treatment and lead to brain perfusion increasing. As they are composed by three different amino acids, the proportions of each one vary in the clinical trials, making difficult to clarify which substance is more involved in brain perfusion and other significant endpoints. The aim of this study was to compare clinical and brain perfusion effects obtained by supplementation of leucine versus isoleucine for HE treatment. Methods: Fifty outpatients with cirrhosis and HE were randomized to receive oral supplements containing 30 g of leucine or isoleucine on a daily basis for one year. Clinical evaluations and nutritional assessment were performed bimonthly. Brain Single Photon Emission Computed Tomography (SPECT) and dynamic brain scintigraphy were performed pretreatment and at 1, 8 and 12 months of supplementation. Twenty-seven subjects concluded the study (16 taking isoleucine and 11 taking leucine). Results: Increasing in brain perfusion was observed only in the isoleucine group. The increase was documented at 8 months of treatment by both SPECT and brain scintigraphy (p<0.001 and p= 0.05, respectively) and by SPECT at the 12th month (p <0.05). It was associated with a significant HE improvement at 8 and 12 months in this group (p=0.008 and 0.004, respectively), which was less clear in the leucine group (p=0.313 and 0.055, respectively). Conclusions: Isoleucine supplementation allowed achieving a better impact on HE manifestations and brain perfusion of patients with cirrhosis. The results suggest that patients with HE should receive more isoleucine than leucine. / FAPESP: 2013/11761-2
14

Relação dos níveis de magnésio sérico e encefalopatia hepática no período imediato ao transplante de fígado = Correlation between serum magnesium levels and hepatic encephalopathy in immediate post liver transplantation period / Correlation between serum magnesium levels and hepatic encephalopathy in immediate post liver transplantation period

Lopes, Paula Juliano, 1985- 21 August 2018 (has links)
Orientador: Ilka de Fátima Santana Ferreira Boin / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Ciências Médicas / Made available in DSpace on 2018-08-21T06:35:36Z (GMT). No. of bitstreams: 1 Lopes_PaulaJuliano_M.pdf: 1567108 bytes, checksum: dc73b9dfaf095d0ab3b2616cdc04dbd1 (MD5) Previous issue date: 2012 / Resumo: O transplante de fígado é um procedimento complexo que interfere em múltiplas funções do organismo podendo ocorrer complicações de diversas dimensões. Estudos revelam porcentagens variadas de complicações do sistema nervoso entre 8 - 47% dos casos e podem incluir encefalopatia, problemas cerebrovasculares, infecções e neurotoxicidade induzida por imunossupressores, sendo que a maioria destes casos ocorre na primeira semana de pós-operatório.. O objetivo do estudo foi verificar a relação entre o valor de magnésio sérico e o desenvolvimento de encefalopatia no período imediato ao transplante de fígado. Para realizar a pesquisa, foram coletados dados dos pacientes e doadores presentes em prontuários médicos de pacientes que tenham sido submetidos a transplante de fígado nos anos de 2007 a 2009. Os valores dos níveis de magnésio sérico dos sete primeiros dias de internação foram comparados com a referência laboratorial presente nos resultados revelados pelo laboratório do Hospital de Clínicas da Unicamp. O critério de West Haven foi usado para classificar se o paciente apresentava ou não encefalopatia hepática. Verificou-se que apenas o valor do magnésio no pós transplante foi o risco para que ocorresse a encefalopatia hepática (p = 0.0489). Quanto menor o valor do nível de magnésio sérico maior foi o risco de ocorrência de encefalopatia hepática (RR = 3.718; IC95% : 1.001-13.699). Como conclusão verificou-se a importância da hipomagnesemia como fator preditivo do aumento do risco de aparecimento da encefalopatia hepática no pós transplante imediato de fígado / Abstract: Liver transplantation is a complex procedure that interferes in multiple body functions and complications can occur in several dimensions. Studies have shown varying percentages of the nervous system complications from 8 to 47% of cases and may include encephalopathy, cerebrovascular problems, infections and neurotoxicity induced by immunosuppressive drugs, with the majority of these cases occurs in the first week after surgery. The objective was verify the correlation between the level of serum magnesium and the development of encephalopathy in the immediate post transplant period. To conduct the survey, the donor's and receptor's data from patients submitted to liver transplantation were collected in the medical transplant patients' records from 2007 to 2009. The levels of serum magnesium to in the first seven days of hospitalization were compared with the reference laboratory results by the Clinical Hospital of Unicamp. The West Haven criteria was used to classified if the patient have or not hepatic encephalopathy. It was found that only the levels of serum magnesium in post transplant was the risk for hepatic encephalopathy occurrence (p = 0.0489). The lower value of magnesium increased the risk of hepatic encephalopathy (RR=3.718; IC95% : 1.001- 13.699). In conclusion, we verified the importance of hypomagnesemia as predictive factor for hepatic encephalopathy increasing after liver transplantation / Mestrado / Fisiopatologia Cirúrgica / Mestra em Ciências
15

Encéphalopathie hépatique chez les patiens atteints de cirrhose : le TIPS comme facteur de risque, apport de l'IRM multitmodale / Hepatic encephalopathy in aptients with cirrhosis : pathophysiology, TIPS as a risk factor, multimodal MRI for the prediction of neurological prognosis after TIPS placement

Rudler, Marika 11 December 2017 (has links)
Le TIPS (Transjugular Intrahepatic Portosystemic Shunts) est le traitement de référence au cours de l'hémorragie digestive par rupture de varices, ou dans le traitement de l'ascite réfractaire chez les patients atteitns de cirrhose. Il peut entraîner une encéphalopathie hépatique (EH), dans 35% des cas environ. L'imagerie par résonnance magnétique (IRM) cérébrale est l'examen de référence pour le diagnostic et le pronostic des maladies neurologiques. L'IRM multimodale combine la spectroscopie, l'imagerie par tenseur de diffusion, et l'IRM fonctionnelle de repos. La combinaison de ces différentes techniques a un intérêt pour le pronostic neurologique après traumatisme crânien ou arrêt cardio-respiratoire. Dans la première partie de ce travail, nous ferons une revue de la littérature sur l'EH en 2017. Nous décrirons les bénéfices du TIPS dans la prise en charge des complications de la cirrhose telles que l'hémorragie digestive et l'ascite, et aussi la probabilité de développer une EH après TIPS. La deuxième partie de ce travail sera consacrée à l'IRM cérébrale mutimodale. Nous en expliquerons les principes généraux, puis nous décrirons les données publiées dans la cirrhose. Enfin, nous présenterons les résultats obtenus en IRM cérébrale multimodale chez des patients candidats à la pose d'un TIPS. Nous décrirons en particulier qu'il existe des facteurs prédictifs de développement d'une EH après TIPS. En effet, la fraction d'anisotropie est plus basse dans notre série avant TIPS chez les aptients qui vont développer une EH après TIPS. Ainsi, le tenseur de diffusion pourrait aider à discrimier les patients qui sont les plus à risque de développer une EH. / TIPS placement is required for the management of variceal bleeding or ascites in cirrhosis. However, hepatic encephalopathy (HE) may occur in 35% of patients after TIPS placement. Magnetic resonance imaging (MRI) is the best exam for the diagnosis and the prognosis of several neurological diseases. Multimodal MRI combines spectroscopy, diffusion tensor imaging and resting state. It has been proven to help for neurological prognostic in comatose patients after traumatic brain injury or cardiac arrest. In this manuscript, we will explain HE pathophysiology and management of HE in 2017. We will also describe results obtained with TIPS placement in patients with variceal bleeding. The second part of the manuscript will be dedicated to multimodal MRI: we will clarify each technique and what has been published in the setting of cirrhosis. Last, we will explain our results obtained in patients who are candidate for non urgent TIPS placement and will suggest that a low fractional anisotropy before TIPS may help to identify patients that are at risk of developing HE after TIPS.
16

Autorregulação encefálica na insuficiência hepática fulminante antes e após transplante hepático / Cerebral autoregulation in fulminant hepatic failure before and after liver transplantation

Paschoal Júnior, Fernando Mendes 16 May 2016 (has links)
O presente estudo avaliou a autorregulação encefálica (ARE) em doentes com insuficiência hepática fulminante (IHF) antes e após transplante hepático. Foram avaliados 25 pacientes com diagnóstico de IHF, 17 foram avaliados antes e após o transplante hepático, sendo seis (24,0%) do sexo masculino e 19 (76,0%) feminino. A média de idade foi de 33,8 anos, que variou de 14 a 56 anos, com desvio padrão de 13,1 anos. A hemodinâmica encefálica foi avaliada pela velocidade de fluxo sanguíneo encefálico (VFSE) nas artérias cerebrais médias e artéria basilar (AB), que usou o ultrassom Doppler transcraniano (DTC), dispositivo de dois canais, com transdutores de 2 mega Hertz (MHz). A autorregulação encefálica foi mensurada pelo índice de autorregulação (IARE) estática que leva em conta os efeitos do aumento da pressão arterial média (PAM) sobre a VFSE. Para isso, promoveu-se o aumento da PAM (20 mmHg a 30 mmHg) com infusão de noradrenalina.. Ao se avaliar o IARE considerando a velocidade de fluxo sanguíneo em quatro momentos (pré-transplante, 1°, 2° e 3° dia após o transplante), observou-se que houve diferença estatística em artéria cerebral média (ACM) à direita (p=0,008), esquerda (p=0,007), máxima (p=0,005), e AB (p=0,006); assim como na análise em cada tempo do IARE, observou-se diferença estatística em ACM à direita (p=0,012), esquerda (p=0,009), máxima (p=0,006), e AB (p=0,011). A análise categórica do IARE na artéria cerebral média e basilar descreveu que a maioria dos doentes reestabeleceu a AR no 2° dia em ACM e 3° na AB (índice > 0,6), enquanto com o índice > 0,8 em ambas as artérias a ARE reestabeleceu no 2° dia. As variáveis sistêmicas como pressão parcial de CO2 e hemoglobina nos tempos da avaliação não apresentaram diferença estatística p=0,100 e p=0,093 respectivamente. Os resultados obtidos apontam para o comprometimento da ARE antes e após transplante hepático, tanto em circulação anterior como posterior, e que tende a ser reestabelecido entre 48 a 72 horas. Os achados deste estudo favorecem o manejo adequado de doentes nestas fases (antes e após transplante) e podem evitar a evolução para complicações neurológicas, como tumefação encefálica e hipertensão intracraniana, que indicam prognóstico ruim para a evolução clínica destes doentes. Estudos futuros necessitam ser realizados para que se consolide o uso da monitoração contínua com métodos não invasivos como o DTC para direcionar o manejo hemodinâmico encefálico na IHF / This study evaluated cerebral autoregulation in patients with fulminant hepatic failure (FHF) before and after liver transplantation. A total of 25 patients comprising six (24.0%) males and 19 (76.0%) females with FHF were evaluated. Seventeen patients were evaluated both before and after liver transplantation. Mean age of the patients was 33.8 years, with a range of 14-56 years and standard deviation of 13.1 years. Brain hemodynamics was assessed by cerebral blood flow velocity in the middle cerebral arteries (MCA) and basilar artery (BA) using transcranial Doppler ultrasound on a two-channel device with 2 MHz transducers. Cerebral autoregulation was measured by static cerebral autoregulation index (SCAI), which accounts for the effects of increase in mean arterial blood pressure (ABP) on cerebral blood flow velocity. An increase in ABP (20 mmHg to 30 mmHg) was induced with norepinephrine infusion. Evaluation of SCAI based on blood flow velocity (BVF) at four timepoints (pre-transplant and on 1st, 2nd and 3rd days post-transplant) revealed a statistical difference in the MCA right (p = 0.008) left (p = 0.007), maximum (p = 0.005) and the BA (p = 0.006). In addition, analysis by timepoint showed a statistical difference in MCA (p = 0.012), left (p = 0.009), maximum (p = 0.006) and in the BA (p = 0.011). Categorical analysis of autoregulation in the MCA and BA showed that most patients reestablished autoregulation in the MCA on the 2nd day post-transplant and in the BA (index > 0.6) on the 3rd day, while autoregulation was reestablished in both arteries (index > 0.8) on the 2nd day. On the assessment by timepoint, the systemic variables CO2 partial pressure and hemoglobin showed no statistically significant differences (p = 0.100 and p = 0.093, respectively). The results reveal impaired SCAI before and after liver transplantation, both in anterior and posterior circulation, with a tendency to reestablish at 48 to72 hours. The findings of this study can help improve management of patients at these stages (pre and post transplantation), preventing neurological complications such as brain swelling and intracranial hypertension, associated with poor prognosis for the clinical course. Future studies should be conducted to consolidate the use of continuous monitoring with noninvasive method (TCD), to provide more accurate information to guide brain hemodynamic management in FHF
17

Intoxicação por Trema micrantha (Cannabaceae) em equinos

Bandarra, Paulo Mota January 2010 (has links)
Este estudo caracteriza a intoxicação por Trema micrantha em equinos, até então desconhecida nesta espécie. No primeiro artigo (artigo 1), é descrito um surto espontâneo de intoxicação por T. micrantha em equinos que ocorreu em junho de 2007, no Município de São José do Herval, na região da encosta da serra do Rio Grande do Sul. Dois equinos morreram na propriedade, após uma árvore de T. micrantha ter sido derrubada por um temporal e suas folhas terem sido consumidas pelos animais. O quadro clínico patológico apresentado foi característico de insuficiência hepática aguda, com desenvolvimento de encefalopatia hepática. Subsequentemente, para melhor caracterizar a intoxicação por Trema micrantha em equinos, desenvolveu-se um experimento (artigo 2). Quatro pôneis receberam e consumiram espontaneamente folhas de T. micrantha, em doses únicas de 30, 25 e 20g/kg. Um equino recebeu uma dose de 15 e outra de 25g/kg, 30 dias após. Três animais adoeceram e evoluíram para morte. Os principais sinais clínicos apresentados foram apatia, desequilíbrios, dificuldade de deglutição, decúbito esternal, decúbito lateral, movimentos de pedalagem coma e morte. Os três equinos afetados apresentaram elevação na atividade sérica de gama glutamil transferase (GGT), nos níveis séricos de amônia, além de diminuição da glicemia. Os principais achados patológicos foram encontrados no fígado e no encéfalo dos três animais. O fígado apresentava macroscopicamente acentuação do padrão lobular, enquanto que no encéfalo havia áreas amareladas na superfície de corte, mais evidentes na substância branca do cerebelo. Microscopicamente, o fígado apresentava necrose, predominantemente centrolobular e hemorragia. No encéfalo, havia edema perivascular generalizado e astrócitos Alzheimer tipo II na substância cinzenta. Esses astrócitos apresentaram marcação fraca ou negativa na imuno-histoquímica anti-GFAP e marcação positiva do antígeno S-100. A dose letal mínima de folhas de T. micrantha estabelecida nesse experimento foi de 20g/kg. A maior sensibilidade da espécie equina constatada nesse estudo, a ampla distribuição de T. micrantha, bem como sua palatabilidade reforçam a importância da planta em casos acidentais de intoxicação nessa espécie. / This study characterizes Trema micrantha poisoning in horses, previously unknown in this species. The first article (Article 1) describes an outbreak of T. micrantha poisoning in horses. The disease occurred in June 2007, in the Municipality of São José do Herval, Rio Grande do Sul State. Two horses died after consuming the leaves of the branches from a T. micrantha tree, which had been felled by a storm. Clinical pathology presented by the animals was characteristic of an acute liver failure with development of hepatic encephalopathy. To further characterize the Trema micrantha poisoning in horses, an experiment was carried out (Article 2). Four ponies received and spontaneously consumed green leaves of T. micrantha, at the doses of 30, 25, and 20 g/kg. One horse received two doses, 15 and 25 g/kg, 30 days apart. Three animals were affected and died. The main clinical signs were apathy, equilibrium deficit, deglutition difficulty, sternal or lateral recumbency, paddling, coma and death. These tree diseased ponies had also enhanced seric activity of gamma-glutamyl transferase (GGT), seric ammonia apart of diminished glycemia. The main pathological findings were observed in the liver and encephalon. There were enhanced lobular pattern of the livers and yellowish areas in the cut surface of the encephalon, especially visualized in the cerebral white matter. Microscopically, there was hepatic necrosis predominantly centrilobular apart of hemorrhages. Generalized perivascular edema and Alzheimer type II astrocytes were observed in the encephalon. The Alzheimer type II astrocytes showed weak or absent anti-glial fibrillar acid protein immunostaining associated with positive immunostaining for S-100 protein. The minimal lethal dose of Trema micrantha leaves was established at 20 g/kg. The high sensibility of this species to this plant, its wide distribution, and the high palatability of the plant reinforce the importance of Trema micrantha in accidental episodes of intoxication in horses.
18

Intestinal-mucosale Ammoniogenese bei Patienten mit Leberzirrhose

Kasim, Esmatollah 28 October 2004 (has links)
In der Pathogenese der hepatischen Enzephalopathie nimmt die systemische Hyperam-moniämie eine zentrale Stellung ein. Es konnte kürzlich gezeigt werden, dass der Dünndarm in der postprandialen Hyperammoniämie bei Patienten mit Leberzirrhose eine wichtige Rolle spielt. Somit wird das über die Pfortader der Leber zugeführte Ammonium nicht ausschließlich von Bakterien im Kolon produziert, sondern entstammt in relevanter Menge, beim Versuchstier zu etwa 50%, dem Glutaminstoffwechsel der Dünndarmmukosa . Unter pathologischen Verhältnissen wie bei einer Leberzirrhose und dem Vorliegen portosystemischer Umgehungskreisläufe führt die intestinale Ammoniogenese zur systemischen Hyperammoniämie und hepatischen Enzephalopathie. Hauptziele dieser Studie waren zu untersuchen, welche Stickstoffgruppe des Glutaminmoleküls der intestinalen Ammoniogenese dient, welche Rolle die zweite Stickstoffgruppe des Glutamins spielt, welche anderen Metabolite als Produkte des intestinalen Glutaminmetabolismus entstehen. Wir untersuchten 2 Gruppen à 4 Patienten mit Leberzirrhose, bei denen zuvor ein transju-gulärer intrahepatischer portosystemischer Stent-Shunt (TIPS) angelegt worden war. Die Patienten erhielten während 240 min über eine nasoduodenale Sonde eine Nährlösung bestehend aus markiertem Glutamin, Kohlenhydraten und Fetten. Entweder die Amino- oder Amid-Gruppe des Glutamins war durch das stabile Stickstoff-Isotope (15 N) markiert. Je drei Blutentnahmen wurden aus einem arteriellen, einem Mesenterialvenen- und einem Hepatalvenenkatheter vor (-10, -5 und 0 min) und während der Nährlösungsapplikation (150, 195 und 240 min) entnommen. Die Messung der quantitativen Ammoniumkonzentration erfolgte enzymatisch. Die Aminosäurenkonzentrationen wurde mittels HPLC bestimmt. Die Anreicherung des markierten Stickstoffs im Ammonium und in den Aminosäuren erfolgte mittels GC-MS. Der Transfer des markierten Stickstoffs aus der Amid-Gruppe des Glutamins auf das Ammonium war signifikant höher als aus der Amino-Gruppe (1.66 +/- 0.15 MPE vs 0.05 +/- 0.15 MPE). Dagegen war der Transfer auf die Amino-Gruppen anderer Aminosäuren wie Ala-nin, Serin, Glycin und Prolin nach der Applikation von Amino-markiertem Glutamin signifikant höher als der nach der Applikation von Amid-markiertem Glutamin. Aus diesen Daten kann geschlossen werden, dass das durch den Dünndarm produzierte Ammonium überwiegend aus der Deamidierung des Glutamins über die Gluaminase-Reaktion entstammt. / Systemic hyperammonemia plays a central role in the pathogenesis of the hepatic encephalopathy. Recently it could be demonstrated, that the small intestine is an important source of postfeeding hyperammonemia in patients with cirrhosis. The portal venous ammonia load forms partly, in animals up to 50 %, from glutamine metabolism in small intestine. Under pathologic conditions as in liver cirrhosis with portal-systemic shunting, however, this ammonia load causes systemic hyperammonemia. The Main goals of our study were to investigate, which nitrogen group of glutamine molecule serves the intestinal am-moniogenesis, what role the secound nitrogen group of glutamine plays, and which metabolites are produced within the intestinal glutamine metabolism. We investigate 2 Groups of 4 patients each with liver cirrhosis who had received a transjugular intrahepatic porto-systemic stent-shunt (TIPS) before. The patients got a nutrient solution containing labelled glutamine, carbohydrate and fat over 240 min via a nasoduodenal tube. The glutamine molecule was labelled on its amid or amino group respectively with the stable 15 N-isotope. Blood was taken from an arterial, a mesenterial venous and a hepatic venous catheter before (-10, -5 and 0 min) and during (150, 195 and 240 min) application of the nutrient solution. Ammonia concentrations were measured enzymatically, the concentration of the amino acids by HPLC. The enrichment of the labelled nitrogen in ammonia and amino acids was measured by GC-MS. The amount of labelled nitrogen of the amid group which was transferred to ammonia was significantly higher than the labelled nitrogen transferred from amino group (1.66 +/- 0.15 MPE vs 0.05 +/- 0.15 MPE). In contrast the amino nitrogen was significantly transferred to the amino acids such as alanine, serine, glycine and proline. We conclude that the ammonia produced by small intestine predominantly originates from The amid nitrogen of glutamine by deamidation via glutaminase pathway.
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Μελέτη της επίδρασης του προκαλούμενου από αποφρακτικό ίκτερο οξειδωτικού στρες στις αποφρακτικές συνδέσεις του αιματοεγκεφαλικού φραγμού

Φαρόπουλος, Κωνσταντίνος 27 May 2014 (has links)
Η ηπατική εγκεφαλοπάθεια είναι ένα σύνθετο νευροψυχιατρικό σύνδρομο το οποίο εκδηλώνεται κυρίως σε συνθήκες ηπατικής κίρρωσης. Διάφορες παθολογικές και τοξικές καταστάσεις μπορεί να επηρεάσουν την ηπατική λειτουργία σε τέτοια βαθμό ώστε να προκληθεί ηπατική εγκεφαλοπάθεια. Το οξειδωτικό στρές έχει ενεπλακεί σε διάφορες μελέτες στην παθογένεση της ηπατικής εγκεφαλοπάθειας. Επιπλέον, η ανάπτυξη αυξημένου οξειδωτικού στρές υπό την επίδραση αποφρακτικού ικτέρου έχει μετρηθεί σε διάφορα όργανα πειραματοζώων, συμπεριλαμβανομένου και του εγκεφάλου. Ο σκοπός της παρούσας μελέτης ήταν να ανιχνεύσει της αλλαγές στις αποφρακτικές συνδέσεις των τριχοειδικών αγγείων του εγκεφάλου που συσχετίζονται με την οκκλουδίνη. Για να το επιτύχουμε αυτό χρησιμοποιήσαμε ένα μοντέλο απολίνωσης του κοινού χοληδόχου πόρου (BDL) σε πειραματόζωα (αρουραίους). Στο πείραμα 1 η έκφραση της οκκλουδίνης εκτιμήθηκε μέσω της μεθόδου ποσοτικοποίησης κατά Westernblot. Σε αυτό το πείραμα χρησιμοποιήθηκαν πέντε (BDL) και πέντε ψευδώς χειρουργηθέντα πειραματόζωα (sham). Τα πειραματόζωα θανατώθηκαν δέκα ημέρες μετα το χειρουργείο. Στην κατά Westernblot ποσοτικοποίηση παρατηρήθηκε μεγάλη μείωση της ποσότητας της οκκλουδίνης στα BDL πειραματόζωα σε σχέση με τα sham. Στο πείραμα 2 χρησιμοποιήθηκαν εννέα BDL και εννέα sham πειραματόζωα. Τρία πειραματόζωα από τις δύο παραπάνω ομάδες θανατώθηκαν την πρώτη, την πέμπτη και τη δέκατη μετεγχειρητική ημέρα. Τα επίπεδα οκκουδίνης σε αυτά τα πειραματόζωα συσχετιστήκαν με τις τιμές τηςinvivo μέτρησης των ελευθέρων ριζών οξυγόνο. Τα αποτελέσματα ανέδειξαν ότι η τιμή της οκκλουδίνης στα BDL ζώα ήταν σημαντικά μειωμένη σε σχέση με τα sham όλες τις χρονικές στιγμές που έγιναν οι μετρήσεις, ενώ οι χαμηλότερες τιμές καταγράφηκαν στα πειραματόζωα που παρέμειναν υπό αποφρακτικό ίκτερο για δέκα ημέρες. Επιπλέον καταδείχθη ότι η χρονικά συσχετιζόμενη μείωση των επιπέδων της οκκλουδίνης στα ενδοθηλιακά κύτταρα του εγκεφάλου συσχετίζεται με τα αυξανόμενα επίπεδα ελευθέρων ριζών οξυγόνου της ημέρες μετά το χειρουργείο, φανερώνοντας τη σχέση μεταξύ αυτών των δύο φαινομένων. Συμπερασματικά, η παρούσα μελέτη πρώτη παραθέτει στοιχεία που προτείνουν την εμπλοκή της οκκλουδίνης στην παθοφυσιολογία της ηπατικής εγκεφαλοπάθειας σε συνθήκες εξωηπατικής χολόστασης. Αυτό γίνεται μέσω της μείωσης των επιπέδων τις οκκλουδίνης στις αποφρακτικές συνδέσεις των ενδοθηλιακών κυττάρων του εγκεφάλου υπο την επίδραση του χολοστατικού ικτέρου, η οποία οδηγεί σε άρση του αιματο-εγκεφαλικού φραγμού. / Hepatic encephalopathy in a complicate neuro-psychiatric syndrome which is common under hepatic cirrhosis. Various pathological and toxic lesions can deteriorate liver function in such way, so hepatic encephalopathy can be inflicted. Oxidative stress is involved in pathogenesis of hepatic encephalopathy in several protocols. Moreover the development of increased oxidative stress in the context of obstructive cholestasis has been proven in various rats' organs including the brain. The present study aimed to detect alterations of tight junction-associated occludin in rat brain capillaries. To accomplish that we have used a rats bile duct ligation experimental model (BDL). In experiment 1, occludin expression was evaluated by Western blot analysis. In this experiment were used five BDL and five sham rats. The experimental animals were sacrificed ten days after the operation. Western blot analysis revealed significant decrease of occlidins amount in BDL rats compared to the sham rats. In experiment 2, nine BDL and nine sham animals were used. Three animals from each group were sacrificed during the first, fifth and tenth post-operate day. The results of occludin level to these animals were associated with the in vivo superoxide radical production. The results indicated that occludin level in BDL animals, as opposed to sham-operated, was significantly reduced at every time point studied, being lowest in the rats remaining on BDL condition for 10 days. Moreover, it was demonstrated that the time-dependent reduction of occludin level in the brain endothelial was significantly correlated with the time dependent increase of brain superoxide radical level, implying a relationship between these two abnormalities. In conclusion, the evidence presented herein suggests for first time the implication of occludin in pathophysiology of hepatic encephalopathy under extra-hepatic cholestasis. This phenomenon occur due to the reduce of occludin level to cerebral endothelial cells’ tight junctions under cholestatic jaundice, which drives to lift of brain-blood barrier.
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Kompiuterizuoto inhibicinio kontrolės ir laboratorinių testų vertė nustatant minimalią hepatinę encefalopatiją / Value of computerized inhibitory control test and blood tests in minimal hepatic encephalopathy diagnosis

Savlan, Ilona 03 March 2014 (has links)
Darbo tikslas – nustatyti kompiuterizuoto inhibicinio kontrolės testo (IKT), IL-6, amoniako bei įprastinių kraujo rodiklių vertę diagnozuojant kognityvinius sutrikimus sergantiems lėtinėmis kepenų ligomis. Darbo uždaviniai: nustatyti kognityvinių sutrikimų dažnį, galimus rizikos veiksnius, palyginti IKT ir kraujo testų rezultatus lėtinio hepatito ir kepenų cirozės grupėse; nustatyti IKT bei IL-6, įprastinių kraujo testų vertę minimaliai hepatinei encefalopatijai (MHE). Iki šiol netirta ar pacientai, sergantys lėtiniu hepatitu ir kognityviniais sutrikimais, neturi analogiškų IKT rodiklių pakitimų, IL-6 koncentracijos padidėjimo kaip sergantieji kepenų ciroze ir MHE. Netirta kokie kraujo ar IKT rodikliai kognityvinius sutrikimus prognozuoja geriausia. Į tyrimą įtraukti 62 sergantieji kepenų ciroze be hepatinės encefalopatijos, 73 lėtiniu hepatitu bei 53 sveiki asmenys. Tą pačią dieną buvo atliekami kraujo tyrimai, psichometriniai testai ir IKT. Lėtinio hepatito grupėje kognityviniai sutrikimai nustatyti 54,8 %, о kepenų cirozės grupėje MHE ¬ 71,0 % tiriamųjų asmenų. Kognityvinius sutrikimus predisponuoja trumpesnė mokymosi trukmė, fibrozės laipsnis, dvigubas etiologinis veiksnys, amžius ir lytis įtakos neturi. Lėtinio hepatito grupėje kognityviniai sutrikimai koreliuoja su IKT rodikliais ir kepenų fermentų koncentracijos padidėjimu, o kepenų cirozių grupėje su IKT rodikliais ir IL-6 koncentracija kraujyje. Išvados: Kognityvinius sutrikimus sergant lėtiniu hepatitu ar... [toliau žr. visą tekstą] / The aim of the study was to ascertain a value of computerized inhibitory control test (ICT), routine blood tests, peripheral blood ammonia and IL-6 concentration for diagnosis of cognitive disorders in patients with chronic liver diseases. Tasks: to assess a frequency of cognitive impairments and associated risk factors and to compare ICT and blood tests results in chronic hepatitis and cirrhotic patients; to ascertain ICT, IL-6 and routine blood tests values for diagnosis of minimal hepatic encephalopathy (MHE). Until now there were no studies performed whether chronic hepatitis patients with cognitive disorders have analogous ICT, IL-6 and other tests abnormalities as cirrhotic patients with MHE. It has not been studied which ICT and other tests results predict best the cognitive disorders in such patients. 62 cirrhotic patients without overt hepatic encephalopathy, 73 chronic hepatitis and 53 healthy individuals were enrolled. On the same day blood tests, psychometric and ICT tests were performed by every participant. Cognitive disorders were detected in 54,8% of chronic hepatitis patients. In cirrhotic patients MHE was found in 71,0%. Cognitive disorders predispose shorter study time, the fibrosis score, double etiologic factor, while age and gender has no influence. In chronic hepatitis patients the cognitive impairments correlate with ICT and elevated liver enzymes. In cirrhotic patients cognitive disorders correlate with ICT and IL-6 concentration. Conclusion: the... [to full text]

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