The present studies are based on the premise that pulmonary injury, during periods of hypoxia, ischemia, and reperfusion, may be due to increased production of reactive oxygen species, including the superoxide anion (O₂-), hydroxyl radical (-OH), and hydrogen peroxide (H₂O₂), and on the premise that this injury can be ameliorated by antioxidant pre-treatment. The sulfur-containing (λ²-amino acids, taurine and its precursor, hypotaurine, have been shown indirectly to possess antioxidant properties by several investigators. The mechanism(s) by which taurine and hypolaurine exert their antioxidant effects has(have) remained unclear despite many years of intensive study, as does the precise physiological role for these two β-amino acids. The goals of the present study were: 1) to evaluate the effects of taurine and hypolaurine in experiments that model biochemical events which are believed to be important components of oxidative pulmonary injury; 2) to assess the potential antioxiodant ability of the amino acids by determining their capacity to scavenge the free radicals, -OH and O₂-., directly; and 3) to investigate the effect of these amino acids on reperfusion injury of rat lungs in an ex vivo ischemia-reperfusion injury model. The results of this study indicate that taurine and hypotaurine are not effective in detoxifying H₂O₂ and, in fact, taurine was found to augment H₂O₂ production in phorbol myristate acetate-stimulated macrophages. At 26, 78, and 104 mM, taurine was found to elevate H₂O₂ production 13%, 28%, and 43%, respectively, above the positive control. Taurine (5-120 mM) and hypotaurine (2-10 mM) were also ineffective (p > 0.05) in protecting biomembranes against free radical-induced lipid peroxidation. However, taurine (10-300 mM) and hypotaurine (2-30 mM) were found to possess the ability to scavenge hydroxyl radicals. Taurine (148 and 193 mM) and hypotaurine (19 mM) were found to possess the ability to scavenge superoxide at the high end of the concentration range tested. This was demonstrated by the ability of these amino acids to compete with both ferricytochrome c for available O₂- and deoxyribose for available -OH, within the rdespective systems designed to produce these two reactive species. Additionally, in an EPR study using 5,5-dimethyl-l-pyrroline-Noxide (DMPO) as a spin trap, both taurine and hypotaurine caused dose-dependent inhibition of DMPO-OH and DMPO-OOH adduct formation. In the ex vivo rat lung model, the addition of 5 and 10 mM taurine to the perfusion medium 20 minutes prior to the induction of ischemia appeared not to provide significant protection (p > 0.05) against reperfusion injury to isolated rat lungs exposed to 60 minutes of ischemia followed by 30 minutes of reperfusion. However, the data obtained from the ex vivo lung experiments was variable and must be interpreted with caution. Furthermore, in preliminary studies it was found that 50 mM taurine may be toxic to the isolated, perfused, rat lung. In conclusion, the antioxidant properties of taurine and hypotaurine are due to their capability to scavenge some of the reactive species of oxygen. The apparent inability of low concentrations of taurine to ameliorate post-ischemic reperfusion injury of lungs is consistent with the fact that relatively high concentrations of taurine were needed for the amino acid to demonstrate significant scavenging of O₂- and -OH. / Master of Science

Os prematuros frequentemente necessitam de ajuda para iniciar a respiração, pois líquido amniótico residual e deficiência de surfactante podem impedir o estabelecimento da CRF. A necessidade de intubação e do uso de ventilação com pressão positiva está relacionada à chamada lesão pulmonar induzida pela ventilação. A intubação endotraqueal é uma ocorrência comum na unidade de terapia intensiva neonatal. A extubação acidental (EA) ou o deslocamento acidental do tubo endotraqueal é um evento inseguro e adverso. Um estudo norteamericano relatou que a EA é o quarto evento adverso mais comum na UTIN. Isso coloca o neonato em risco de morbidade significativa. As hipóteses iniciais para este estudo considerando as características locais do serviço, são que a taxa de extubação acidental deste serviço seria superior ou igual à encontrada na literatura e que as consequências da perda de volume pulmonar causada pela EA geraria uma necessidade de aumento de parâmetros ventilatórios, expondo esses pacientes a um maior risco de desenvolvimento de lesão pulmonar induzida pela ventilação mecânica. O presente estudo teve como objetivo estabelecer a densidade de extubação acidental para cada 100 pacientes-dia e os fatores de risco e as consequências associadas à extubação acidental em uma unidade de terapia intensiva neonatal. A coleta de dados ocorreu o período de fevereiro a dezembro de 2016. Foram elegíveis todos os recém-nascidos intubados com necessidade de ventilação mecânica invasiva e selecionados, para o estudo, os recém-nascidos em assistência ventilatória há pelo menos 12 horas. Nos 10 meses e meio de estudo (318 dias), observou-se uma média de 9,04 pacientes intubados por dia, sendo analisados 2875 pacientes-dia com via aérea artificial. Nos 318 dias de observação ocorreram 45 extubações acidentais, com taxa de EA de 1,57 para cada 100 dias intubação. Os recém-nascidos tinham em média 26,55±35,35 dias de vida na EA, mínimo de 3 dias e máximo de 182 dias. Na amostra estudada, todos os recém-nascidos necessitaram de reintubação após o evento de EA. As características clínicas foram semelhantes nos dois grupos. Assim, os dados apresentados evidenciam que os grupos estudados se apresentaram bastante homogêneos. Foram associados como fatores de risco para EA a utilização de material inadequado para a fixação da cânula orotraqueal (esparadrapo), a carência de pessoal para os cuidados diários (mais de 2 pacientes por funcionário), e mostrou-se ainda a grande importância dos alarmes de saturação sanguínea já que foram responsáveis por 60% diagnóstico da ocorrência do evento. A EA acarretou piora das condições respiratórias com necessidade de aumento do suporte ventilatório ( maior necessidade de oxigênio, pressão inspiratória e PEEP) e recuperação lenta às condições pré- acidente em média 5,7 dias. Concomitante com o aumento da necessidade de suporte respiratório houve maior ocorrência de hiperóxia após o acidente, levantando o temor de efeitos deletérios sinérgicos sobre o pulmão já anteriormente debilitado dos prematuros. É necessária a conscientização da administração e das equipes de profissionais da saúde das UTINs unidades, da enorme importância de se prevenir e diagnosticar precocemente a extubação acidental. / Premature infants often require help in initiating breathing, since residual amniotic fluid and surfactant deficiency may prevent the establishment of functional residual capacity. The need for intubation and the use of positive pressure ventilation is related with ventilator-induced lung injury. Endotracheal intubation is a common occurrence in the neonatal intensive care unit. Accidental extubation (AE) or accidental displacement of the endotracheal tube is an unsafe and adverse event. An American study has reported that EA is the fourth most common adverse event in the NICU. This puts the neonate at risk of significant morbidity. The initial hypotheses for this study considering the local characteristics of the service are that the rate of accidental extubation of this service would be higher than or equal to that found in the literature and that the consequences of loss of lung volume caused by the AE would generate a need for increased ventilatory parameters , exposing these patients to a higher risk of lung injury induced by mechanical ventilation. The present study aimed to establish the accidental extubation density for each 100 patients per day and the risk factors and consequences associated with accidental extubation in a neonatal intensive care unit. Data were collected from February to December 2016. All intubated newborns requiring invasive mechanical ventilation were eligible and the newborns in ventilatory assistance were selected for at least 12 hours for the study. In the 10 and a half months of study (318 days), an average of 9.04 intubated patients per day was observed, with 2875 day-patients with artificial airway being analyzed. In the 318 days of observation, there were 45 accidental extubations, with an AE rate of 1.57 for every 100 days of intubation. The newborns had a mean of 26.55±35.35 days of life in AE, a minimum of 3 days and a maximum of 182 days. In the studied sample, all newborns required reintubation after the AE event. As constitutional aspects were seem in the two groups. Thus, the presented data evidences that the studied groups are quite homogeneous. Risk factors for the use of materials for the fixation of the orotracheal waist (tape), a shortage of personnel for the longest care, and the greater importance of the alarms were included. of blood saturation that was responsible for 60% of the occurrence of the event. AE is one of the largest public health service companies in the world, inspiratory pressure and PEEP, and average recurring expenses an average of 5.7 days. Concomitant with the increased risk of respiratory accident for most cases following the occurrence of an accident, raising the risk of fire and synergy over the previous exercise already weakened of the premature. Immigration is an awareness of NICU management and staff of health professionals, which is important in preventing and early diagnosis of accidental extubation.

Le foie et le poumon sont deux organes intimement liés et les atteintes pulmonaires sont fréquentes dans les pathologies hépatiques. En transplantation hépatique, les atteintes pulmonaires, les complications et la morbi-mortalité qu’elles engendrent, peuvent être en lien avec la pathologie hépatique du receveur mais aussi avec le donneur via le greffon, sa qualité et sa préservation. L’objectif de cette thèse était d’étudier deux aspects de cette interaction : 1- l’impact de l’insuffisance respiratoire aigüe (définie par le recours à la ventilation mécanique) sur le devenir post-transplantation ii) les conséquences des phénomènes d’ischémie-reperfusion du greffon hépatique sur les paramètres cardio-pulmonaires du receveur.Dans le premier travail, nous avons étudié, sur une cohorte de patients transplantés hépatiques à l’Hopital Henri Mondor (n=350 patients), le devenir post-opératoire en fonction de la présence ou non d’une ou plusieurs défaillances d’organe (neurologique, respiratoire, rénale, hémodynamique, hépatique et de la coagulation). Les patients avec au moins une défaillance d’organe ont une diminution significative de la survie post-LT à 90 jours (79% contre 96%) et 1 an (70% contre 91%) comparés aux patients cirrhotiques sans défaillance. Dans un deuxième travail issu de la même cohorte, nous développons un modèle permettant de prédire la mortalité à court terme et composé de 6 facteurs dont l’existence d’une défaillance d’organe. Le 3e travail, avec un effectif plus important (cohorte de l’Agence de la Biomédecine, PHRC « Optimatch »), a cherché à confirmer nos premiers résultats et à étudier le poids de chacune des défaillances d’organe et en particulier de la défaillance pulmonaire. Non seulement la présence d’une défaillance mais le nombre de défaillances au moment de la TH influence négativement le devenir à 3 mois des transplantés hépatiques. De plus, les défaillances pulmonaire et rénale sont des facteurs de risque indépendant de mortalité à 3 mois post-transplantation. Ces travaux montrent aussi que l’influence de ces défaillances d’organe peut être modulée en fonction du type de greffon, i.e. des critères du donneur.En plus de la qualité du greffon hépatique, la conservation de celui-ci a un impact sur la fonction du greffon et sur les paramètres cardio-pulmonaires chez le receveur. En effet dans un modèle de transplantation hépatique chez le gros animal (cochon), nous avons montré que les lésions d’ischémie/reperfusion du greffon engendrées entre le prélèvement et l’implantation ont des conséquences sur la fonction du greffon, le myocarde et le poumon. Ces lésions sont modulables selon la technique de préservation, notamment via l’utilisation de machine de perfusion.Ces travaux démontrent qu’au cours de la transplantation hépatique l’atteinte du parenchyme pulmonaire a un rôle clinique majeur chez le receveur et est médiée en partie par des phénomènes d’ischémie-reperfusion du greffon potentiellement modifiables par des améliorations des pratiques médicales. / Liver and lung are two closely related organs. In liver transplantation, lung damage, complications, morbidity and mortality can be related to the liver disease of the recipient but also to the donor via the graft, its quality and its preservation. The aim of this manuscript was to study two aspects of these interactions: 1- the impact of acute respiratory failure (defined by the use of mechanical ventilation) on the post-transplantation outcome ii) the consequences of the ischemia-reperfusion injury of the graft on cardiopulmonary parameters in the recipient.In the first study, we investigated the impact of one or more organ failure (cerebral, lungs, kidney, circulation, hepatic and coagulation) on the 90-day mortality post LT. Patients with at least one organ failure had a significant decrease in post LT survival at 90-day (79% versus 96%) and 1 year (70% versus 91%) compared with cirrhotic patients without failure. In a second study, from the same cohort, we developed a model to predict short-term mortality. This model is composed of 6 factors including the existence of organ failure. In the third study, with a largest cohort (Agence de Biomedicine, PHRC “Optimatch”), we have confirmed these first results and we observe that the number at the LT influences the outcome. Decision tree-modeling identified 6 subgroups further classified in 4 increasing risk classes, highlighting the prognostic importance of respiratory failure and renal failure at the LT as well as complex interactions between donor and recipient features.In addition to the quality of the graft, its preservation has an impact on the graft function and on the cardiopulmonary parameters in the recipient. Indeed, in a model of LT in the large animal (pig) we show that the ischemia / reperfusion injuries, generated between the sampling and the implantation, have consequences on graft function, myocardium and lung. These lesions could be subdued according to the preservation technique.These studies demonstrate that during LT the recipient's pulmonary complications and its morbidity are related to the recipient’s pre-existing hepatic disease and to the donor via the graft through ischemia-reperfusion phenomena of the graft.

Made available in DSpace on 2014-12-17T14:03:33Z (GMT). No. of bitstreams: 1 JannisonKCR_DISSERT.pdf: 3798069 bytes, checksum: 8a7cf649e9d79113b8221c30286c11d0 (MD5) Previous issue date: 2010-05-07 / Conselho Nacional de Desenvolvimento Cient?fico e Tecnol?gico / Seeds from legumes including the Glycine max are known to be a rich source of protease inhibitors. The soybean Kunitz trypsin inhibitor (SKTI) has been well characterised and has been found to exhibit many biological activities. However its effects on inflammatory diseases have not been studied to date. In this study, SKTI was purified from a commercial soy fraction, enriched with this inhibitor, using anion exchange chromatography Resource Q column. The purified protein was able to inhibit human neutrophil elastase (HNE) and bovine trypsin. . Purified SKTI inhibited HNE with an IC50 value of 8 ?g (0.3 nM). At this concentration SKTI showed neither cytotoxic nor haemolytic effects on human blood cell populations. SKTI showed no deleterious effects on organs, blood cells or the hepatic enzymes alanine amine transferase (ALT) and aspartate amino transferase (AST) in mice model of acute systemic toxicity. Human neutrophils incubated with SKTI released less HNE than control neutrophils when stimulated with PAF or fMLP (83.1% and 70% respectively). These results showed that SKTI affected both pathways of elastase release by PAF and fMLP stimuli, suggesting that SKTI is an antagonist of PAF/fMLP receptors. In an in vivo mouse model of acute lung injury, induced by LPS from E. coli, SKTI significantly suppressed the inflammatory effects caused by elastase in a dose dependent manner. Histological sections stained by hematoxylin/eosin confirmed this reduction in inflammation process. These results showed that SKTI could be used as a potential pharmacological agent for the therapy of many inflammatory diseases / Sementes de leguminosas s?o conhecidas como uma rica fonte de inibidores de proteinases, destacando-se dentre estes o inibidor de tripsina da soja (SKTI) que ? uma prote?na amplamente estudada e caracterizada para muitas propriedades biol?gicas. Entretanto seus efeitos aplicados a desordens inflamat?rias ainda s?o pouco conhecidos. SKTI foi purificado ? partir de uma fra??o comercial de soja atrav?s de cromatografia de troca ani?nica em Resource Q. A prote?na purificada foi capaz de inibir a elastase de neutr?filos humanos (ENH) e a tripsina bovina. O valor da sua IC50 foi de 8 μg.mL-1 (0.3 nM) e nessa concentra??o o SKTI n?o foi capaz de provocar efeitos hemol?ticos ou citot?xicos sobre as popula??es celulares sangu?neas humanas. Por meio do modelo de toxicidade sist?mica aguda, utilizando camundongos, tamb?m n?o foram observados efeitos delet?rios sobre ?rg?os, c?lulas sangu?neas e altera??es nos n?veis das enzimas hep?ticas aspartato amino transferase (AST) e alanina amino transferase (ALT). Neutr?filos humanos incubados com SKTI na concentra??o de 0.3 nM apresentaram uma diminui??o da libera??o de ENH quando estimulados pelos ativadores PAF e fMLP (83,1% e 70 %, respectivamente). Estes resultados mostram que o SKTI foi capaz de afetar ambas as vias PAF/fMLP de libera??o de ENH, sugerindo esta prote?na como um poss?vel antagonista dos receptores PAF/fMLP. Modelos in vivo de inj?ria pulmonar aguda mediante estimula??o por LPS de Escherichia. coli demonstraram uma supress?o significativa dos eventos inflamat?rios atribu?dos ? atividade elast?sica de forma dose dependente. Cortes histol?gicos corados por hematoxilina e eosina confirmaram a diminui??o da inflama??o tecidual. Estes resultados sugerem que o SKTI pode ser indicado como um potencial agente farmacol?gico na terapia de muitas doen?as inflamat?rias