Introdução: A lesão renal por isquemia-reperfusão (IR) pode ser reduzida através de estratégias protetoras, entre elas a hipotermia e o pré-condicionamento isquêmico remoto (PCIR). A combinação destas sustenta um potencial efeito protetor a ser esclarecido. Objetivos: Avaliar os efeitos da associação entre o pré-condicionamento isquêmico remoto e a hipotermia tópica em relação às lesões renais por IR, especialmente quanto ao estresse oxidativo e as alterações histológicas no tecido renal. Métodos: Cirurgias experimentais em trinta e dois ratos Wistar, os quais foram aleatoriamente selecionados para quatro protocolos cirúrgicos: 1 - isquemia do pedículo renal esquerdo por 40 minutos seguido de reperfusão sob eutermia (37 o C); 2 - isquemia do pedículo renal esquerdo por 40 minutos seguido de reperfusão sob hipotermia local (4 o C); 3 - PCIR através de clampeamento da artéria ilíaca esquerda por 15 minutos seguido reperfusão por 10 minutos, prosseguindo para isquemia do pedículo renal esquerdo por 40 minutos seguido de reperfusão sob eutermia; 4 - PCIR através de clampeamento da artéria ilíaca esquerda por 15 minutos seguido reperfusão por 10 minutos, prosseguindo para isquemia do pedículo renal esquerdo por 40 minutos seguido de reperfusão sob hipotermia local. Todos os ratos sofreram nefrectomia direita no início do procedimento, sendo estes rins considerados o grupo controle. Após 240 minutos de reperfusão da IR, os animais foram submetidos a um segundo procedimento cirúrgico para a nefrectomia esquerda. Todos os rins foram submetidos a avaliação tecidual, onde foram analisados o grau de necrose tubular aguda pela avaliação histopatológica, além do estresse oxidativo através da dosagem de isoprostanos e medida da atividade da superóxido dismutase e catalases. Avaliamos, ainda, as diferenças de creatinina plasmáticas antes e depois do experimento Resultados: A combinação de PCIR com hipotermia durante experimento de IR revelou ausência de diferenças comparado aos outros grupos de intervenção na análise do padrão histológico (p=0.722). O estresse oxidativo não apresentou variações significativas entre os grupos, exceto na medida do superóxido dismutase que foi mais elevada nos protocolos de isquemia fria (p<0.05). Animais submetidos a protocolos de IR sob hipotermia demonstraram menores valores de creatinina sérica ao término dos procedimentos (p<0.001). Conclusão: A associação de pré-condicionamento isquêmico remoto com hipotermia local não gera proteção renal na lesão por IR. A hipotermia isolada, entretanto, parece ser efetiva na preservação da função renal durante eventos isquêmicos. Em nosso estudo, o pré-condicionamento isquêmico remoto isolado seguido de IR quente (37ºC) não demonstrou benefícios nos parâmetros avaliados comparado à IR quente sem PCIR ou mesmo grupo controle, sugerindo que este modelo experimental de pré-condicionamento isquêmico remoto possui restrições na análise da janela precoce de proteção. / Introduction: Ischemia-reperfusion injury (IR) can be reduced using protective measures such as hypothermia and remote ischemic preconditioning (RIPC). The combination of these might result in potential protective effects to be clarified. Objectives: To assess the effects of the association between RIPC and topical hypothermia in relation to renal IR injuries, especially regarding oxidative stress and histological changes in renal tissue. Methods: Experimental surgeries in thirty two Wistar rats, which were randomly selected to four surgical protocols: 1 - IR by left renal pedicle ischemia for 40 minutes followed by single reperfusion (37 o C); 2 - IR by left renal pedicle ischemia for 40 minutes followed by reperfusion under local hypothermia (4 o C); 3 - RIPC by clamping the left iliac artery for 15 minutes followed by reperfusion for 10 minutes, proceeding to ischemia of the left renal pedicle for 40 minutes followed by reperfusion (37 o C); 4 - RIPC by clamping the left iliac artery for 15 minutes followed by reperfusion for 10 minutes, proceeding to ischemia of the left renal pedicle for 40 minutes followed by reperfusion under local hypothermia (4 o C). All rats underwent right nephrectomy at the beginning of the procedure, and these kidneys considered the control group. After 240 minutes of reperfusion, the animals were submitted to a second surgical procedure for left nephrectomy. All kidneys underwent tissue evaluation, describing the degree of acute tubular necrosis with histopathological analysis. Oxidative stress assessment occurred through isoprostane dosing and measurement of superoxide dismutase and catalase activity. Differences in plasmatic blood creatinine were evaluated before and after the experiment Results: RIPC combined with cold ischemia during IR experiment revealed no differences compared to any of the other interventional groups regarding the analysis of histological changes (p=0.722). Oxidative stress shows no significant variations among groups, except in superoxide dismutase measurements which were higher in cold protocols compared to warm protocols (p<0.05). Serum creatinine at end of procedure showed lower levels in the animals submitted to hypothermic IR protocols (p<0.001). Conclusion: Combining remote ischemic preconditioning and local hypothermia provides no renal protection in IR injury. Hypothermia, however, seems to be effective in preserving renal function during ischemic events. Furthermore, in our study remote preconditioning solely followed by warm IR did not show benefits in any of the evaluated parameters compared to warm IR alone or control groups, suggesting that this experimental model of preconditioning has limitations in the early window of protection analysis (< 24 hours).

Les cardiofibroblastes (CF) possèdent des rôles clés dans la régulation de la structure et du fonctionnement myocardique. Leurs implications physiopathologiques, notamment dans le remodelage et la fibrose, ont été largement décrites dans les maladies cardiovasculaires chroniques. Cependant, leurs rôles au cours de la phase aigüe d'ischémie-reperfusion (l/R) restent encore à élucider. Nous avons donc émis l'hypothèse que les CF pouvaient participer à la protection des cardiomyocytes (CM) face aux lésions d'l/R. Le but de ce travail a donc consisté en l'exploration et l'identification des mécanismes de cette protection. Un modèle cellulaire de CM et CF de rats nouveau-nés in vitro et un modèle d'l/R in vivo chez la souris ont été utilisés. Nos résultats montrent que la présence des CF, en co-culture avec les CM, augmente de façon paracrine leur viabilité, face aux lésions d'l/R. Cette action paracrine a été confirmée par l'utilisation du sécrétome de CF hypoxiques capable, à lui seul, d'augmenter la viabilité des CM. Ces résultats ont été corroborés par des expériences d'l/R in vivo, dans lesquelles les souris traitées avec le sécrétome de CF présentent une diminution de la taille d'infarctus. De plus, nous avons montré que TlMP-1, un facteur fortement détecté dans le sécrétome de CF, est capable de diminuer à la fois la mortalité cellulaire in vitro des CM et la taille de l'infarctus in vivo. L'utilisation d'inhibiteurs pharmacologiques nous a permis de mettre en évidence que cette protection paracrine était médiée en partie par l'activation des voies de signalisation Pl3K/Akt et ERK1/2. En conclusion cette étude démontre pour la première fois que les CF participent, de façon paracrine, à la protection des CM au cours la phase aigüe d'ischémie reperfusion. TlMP-1 semble être un des facteurs clé de cette cardioprotection par les CF. En parallèle de ce travail, plusieurs études collaboratives ont été réalisées, sur une cible majeure d'investigation dans la cardioprotection : le pore de transition de perméabilité mitochondriale et notamment sa régulation par le complexe l de la chaîne respiratoire et les échanges calciques, ainsi que son implication dans la défaillance multi-organe face à l'arrêt cardiaque / Roles of cardiac fibroblasts (CF) in the regulation of myocardial structure and function have been emphasized in the last decade. Their implications in pathophysiological aspects of chronic heart diseases such as myocardial remodelling and fibrosis is now well established. However their contribution to the acute phase of ischemia reperfusion injury still remains elusive. We hypothesized that CF may contribute to cardiomyocytes (CM) protection against ischemia reperfusion (l/R) injuries. This study was designed to investigate this protection and identify some of its mechanisms. Experiments were performed both on isolated neonatal rat CF and CM in vitro and in vivo mice model of myocardial infarction. We demonstrated that the presence of CF increases CM viability in co-cultures and that CF protect CM against l/R injuries in a paracrine manner. lt was confirmed by a similar effect of hypoxic CF secretome alone on CM viability. These findings were corroborated by in vivo experiments in which an infarct size reduction was observed in CF secretome treated mice. Furthermore, experiments with Tissue lnhibitor of Metalloproteinases-1 (TlMP-1), abundantly detected in CF secretome, was able to both decrease CM cell death and infarct size. Experiments with pharmacological inhibitors provided more evidence that this paracrine protection is partly mediated by Pl3K/Akt and ERK signalling pathways. Our data demonstrated for the first time that CF participate in cardioprotection during the acute phase of ischemia reperfusion, via a paracrine pathway, involving TlMP-1. Besides this first work, other collaborative studies have been performed, to investigate a major target in cardioprotection research : the mitochondrial permeability transition pore and its regulation by chain respiratory complex l and Ca2+ transfers and finally its implication in multiple organ failure in cardiac arrest

Neutrophils are significant players in both acute and chronic inflammatory conditions, and function in infectious and autoimmune ailments. MicroRNAs regulate homeostasis in health and disease by fine tuning the expression of a network of genes through post transcriptional regulation. Many microRNAs are expressed in restricted tissues, regulated by physiological conditions such as stress and disease, and are emerging as mediators for intercellular communication that shape the tissue environments. MicroRNA profiles have been recently utilized as biomarkers for diagnosis and prognostic purposes for their stability in plasma and significant correlation with the disease progress. In addition, several microRNAs are in clinical trials for infectious diseases, cardiovascular disorders and cancer. As for neutrophil biology, microRNAs that regulate hematopoiesis and neutrophil development are well known. However, only a few microRNAs are characterized in the context of neutrophil migration and activation by loss of function studies either in mice or in cell culture. In this work we characterize the role of total microRNA regulation on neutrophil function through whole body and neutrophil specific Dicer1 knockout, and identify a microRNA regulator of neutrophil motility. MiR-722 downregulates the transcript level of rac2 through binding to a seed match in the rac2 3'UTR. Furthermore, miR-722 over-expressing larvae display improved outcomes in both sterile and bacterial systemic models. Finally, the miR-722 mimics protect zebrafish from lethal LPS challenge, providing evidence and mechanism of an anti-inflammatory microRNA that restrains detrimental systemic inflammation. We further investigated the role of the inflammatory response in an ischemia-reperfusion model. Extensive future work is required, especially in animal models, to illustrate the pivotal and complex microRNA mediated regulatory network in neutrophils, which is expected to provide the foundation for highly selective microRNA based therapy to control neutrophil behavior in infection and inflammatory disorders.

INTRODUÇÃO: A isquemia-reperfusão pulmonar e o uso do oxigenador de membranas são considerados fatores importantes na resposta inflamatória após a cirurgia cardíaca (CC) com utilização da circulação extracorpórea (CEC). Estudos anteriores que utilizaram os próprios pulmões dos pacientes como oxigenador em uma circulação extracorpórea biventricular (CECBV) em comparação à CEC convencional (CECC) mostraram efeitos benéficos na mecânica pulmonar e na reação inflamatória sistêmica. No entanto, a inflamação pulmonar ainda não foi totalmente esclarecida neste cenário. Os objetivos deste estudo foram observar o impacto da exclusão do oxigenador de membranas e da manutenção da ventilação e perfusão pulmonar na inflamação regional em porcos submetidos à CEC. MÉTODOS: Vinte e sete porcos ventilados mecanicamente foram submetidos à toracotomia e alocados randomicamente nos grupos: Controle (n=8), CECC (n=9) e CECBV (n=10). Os animais dos grupos CECC e CECBV foram submetidos respectivamente a uma CEC convencional ou a uma CEC biventricular com ventilação e perfusão pulmonar sem oxigenador de membranas por 90 minutos. As interleucinas (ILs) séricas foram avaliadas nos momentos: basal, após a CEC e 90 minutos após a CEC, e em momentos equivalentes no grupo Controle. As ILs do lavado broncoalveolar (LBA) foram medidas nos momentos basal e 90 minutos após a CEC. Amostras de tecido pulmonar foram coletadas da região ventral e dorsal do lobo pulmonar esquerdo para avaliação do número de polimorfonucleares (PMN) e quantificação do edema pela área de parênquima. Os dados foram avaliados através de ANOVA, considerando-se estatisticamente significante p<0,05. RESULTADOS: O grupo CECC apresentou uma maior inflamação, com um aumento no número de PMN, comparado ao grupo Controle (p < 0,001) nas regiões: ventral (2,8 x10-6± 0,7 x10-6 vs. 1,6 x10-6 ± 0,5 x10-6 , respectivamente) e dorsal (3,3 x10-6 ± 1,0 x10-6 vs. 1,9 x10- 6 ± 0,5 x10-6, respectivamente) e ao grupo CECBV (p = 0,006) nas regiões: ventral (2,3 x10-6 ± 0,7 x10-7) e dorsal (2,1 x10-6 ± 0,7 x10-6). Edema foi maior no grupo CECC comparado ao Controle nas regiões ventral e dorsal (2,4 x10-2 ± 3,5 x10-2 vs. 8,2 x10-4 ± 0,2 x10-4 e 5,7 x10 -2 ± 4,3 x10-2 vs. 0,3 x10-2 ± 1,0 x10-2, respectivamente, p = 0,016) e mais intenso na região dorsal em todos os grupos (p = 0,004). As IL 10 e IL6 do LBA foram maiores nos grupos submetidos à CECC (41,9 ± 12,2, p = 0,010 e 239,4 ± 45,2, p < 0,001, respectivamente) e à CECBV (40,7 ± 12,0, p = 0,016 e 174,8 ± 61,2, p = 0,004, respectivamente) comparadas ao Controle (21,0 ± 6,9 e 71,8 ± 29,8, respectivamente). As ILs séricas não diferiram entre os grupos (p > 0,05). O Grupo CECC, comparado ao grupo CECBV, mostrou um aumento maior com o tempo na IL6 do LBA (239,4 ± 45,2 vs. 174,8 ± 61,2, p = 0,027, respectivamente) e na IL8 sérica (193,1 ± 108,8 vs. 147,0 ± 59,4, p = 0,040, respectivamente). CONCLUSÕES: Em modelo experimental de circulação extracorpórea em porcos, a manutenção da perfusão e ventilação dos pulmões na CEC biventricular atenua a inflamação pulmonar em comparação à CEC convencional / BACKGROUND: Lung ischemia-reperfusion injury and the membrane oxygenator are considered important factors in the inflammatory response after cardiac surgery and cardiopulmonary bypass (CPB). Previous studies using the own lung as the oxygenator with a biventricular bypass demonstrated the beneficial effects of this technique. However, lung inflammation was not fully evaluated in this scenario. The aim of this study was to observe the impact of the exclusion of the membrane oxygenator and maintenance of lung perfusion on regional lung inflammation in pigs undergoing cardiopulmonary bypass. METHODS: Twenty-seven mechanically ventilated pigs were subjected to a thoracotomy and randomly allocated into Control (n=8), CPB (n=9) or Lung Perfusion (n=10) groups. Animals from the CPB group and Lung Perfusion group were subjected respectively to a conventional CPB or to a biventricular bypass with pulmonary ventilation and perfusion without a membrane oxygenator for 90 minutes. The systemic interleukins (ILs) were determined at baseline, after bypass and 90 min after bypass or at equivalent times in the Control group. ILs from bronchoalveolar lavage fluid (BAL) were evaluated at baseline and 90 min after bypass. Tissue samples were collected from the dorsal and ventral regions of the left lung for assessment of the number of polymorphonuclear leukocytes (PMN) per parenchyma area and edema. Data were evaluated using ANOVA and p< 0.05 was considered significant. RESULTS: The CPB group showed increased lung inflammation, with an increased PMN count compared to the Control (p<0,001) at ventral (2.8 x10-6± 0.7 x10-6 vs. 1.6 x10-6± 0.5 x10-6 , respectively) and dorsal regions (3.3 x10-6 ± 1.0 x10-6 vs. 1.9 x10-6 ± 0.5 x10-6, respectively) and to Lung Perfusion Group (p = 0.006) at ventral (2.3 x10-6 ± 0.7 x10-7) e dorsal regions (2.1 x10-6 ± 0.7 x10-6). Edema was higher in the CPB group compared to the Control at ventral and dorsal regions (2.4 x10-2± 3.5 x10-2 vs. 8.2 x10 -4± 0.2 x10-4 and 5.7 x10 -2 ± 4.3 x10-2 vs. 0.3 x10-2 ± 1.0 x10-2, respectively, p = 0.016) and increased in the dorsal region in all groups (p = 0.004). BAL IL10 and IL6 were higher in groups subjected to CPB group (41.9 ± 12.2, p = 0.010 e 239.4 ± 45.2, p<0.001, respectively) and to Lung Perfusion group (40.7 ± 12.0, p = 0.016 e 174.8 ± 61.2, p = 0.004, respectively) compared to Control group (21.0 ± 6.9 e 71.8 ± 29.8). Systemic interleukins did not differ between groups (p > 0.05). The CPB group compared to Lung Perfusion group showed a higher increase in BAL IL6 (239,4 ± 45,2 vs. 174,8 ± 61,2, p = 0,027, respectively) and in serum IL8 over time (193,1 ± 108,8 vs. 147,0 ± 59,4, p = 0,040, respectively). CONCLUSIONS: In a pig model of extracorporeal circulation, maintenance of lung perfusion and ventilation with biventricular bypass attenuates the pulmonary inflammation as compared to conventional CPB

Objetivo: Estabelecer relação entre a sobrevivência de retalhos cutâneos em ilha submetidos à isquemia prolongada e o uso da estreptoquinase e do alopurinol administrados após o período de isquemia prolongado. Método: Foram utilizados 48 ratos machos da raça Wistar, com pesos entre 300 e 350g, divididos em quatro grupos com 12 cada um, sendo; grupo controle, alopurinol, estreptoquinase e associação de alopurinol com estreptoquinase, submetidos à dissecção de retalho epigástrico em ilha, seguido de clampeamento do feixe vascular, por 8 horas em isquemia mista normotérmica. Após este período, as pinças foram retiradas e cada animal recebeu o esquema terapêutico proposto através de injeção intravenosa. A análise da sobrevivência dos retalhos foi realizada no sétimo dia de pós-operatório. Foram realizadas análises descritivas (% de área necrótica) e de variâncias, bem como, comparações múltiplas de Dunnett T3 entre os quatro grupos e o teste da mediana. Resultados: O grupo controle apresentou em média 79,88% de necrose da área total, aqueles que receberam alopurinol apresentaram em média 64,05% de necrose e o grupo que recebeu estreptoquinase apresentou em média 55,52% de necrose. Com a associação das duas drogas os ratos apresentaram em média 54,30% de área necrótica. Aplicando o teste Dunnett e o teste da mediana verificouse de que o grupo estreptoquinase é o que possui o menor percentual de necrose neste estudo, e o que apresentou diferença estatística significativa em relação ao grupo controle. Conclusão: A administração sistêmica da estreptoquinase após 8 horas de isquemia mista normotérmica resultou em aumento da sobrevivência de retalhos epigástricos em ilha em ratos, quando comparado à administração de alopurinol, associação do alopurinol e estreptoquinase e do grupo controle / Background: To establish a relation between the survival rate of island skin flaps submitted to a prolonged ischemia and the effect of streptokinase and allopurinol administered after the ischemic period. Methods: A total of 48 male Winstar rats, each weighing between 300 and 350 grams, separated in four groups of twelve each, as follows: control, alopurinol, streptokinase and association of allopurinol and streptokinase, were submitted to an epigastric island flap dissection followed by the epigastric vessel bundle clamping. Flaps remained this way for 8 hours in normothermic mixed ischemia. After the ischemic period, the clamps were removed and each rat received the therapeutical scheme proposed for the group through intravenous injections. Flap survival analysis was performed on the seventh post operative day. Variance and descriptive analyses (as a percentage of the necrotic area) as well as Dunnett-T3 multiple comparisons among the 4 groups and median tests were carried out. Results: Rats in the control group presented an average of 79.88% of necrosis in the flap total area; those which received allopurinol presented an average of 64.05% of necrosis whereas the group which received streptokinase showed an average of 55.52% of necrosis. With the association of both drugs, rats presented an average of 54.30% of necrosis in the flap total area. . By applying Dunnet test and the median test, we could verify that the streptokinase group had the lowest necrosis rate in this study. Conclusion: The systemic administration of streptokinase after 8 hours of normothermic global ischemia resulted in an increase in survival rate of epigastric island skin flaps in rats, when compared to the administration of alopurinol, association of the two drugs and the control group

Η µεταµόσχευση πνεύµονα είναι µια αποδεκτή θεραπευτική λύση για τους ασθενείς µε πνευµονική νόσο τελικού σταδίου. Η πρώιµη δυσλειτουργία του µοσχεύµατος παραµένει µία από της κύριες αιτίες πρώιµης θνητότητας και νοσηρότητας. Το σύνδροµο ισχαιµίας – επαναιµάτωσης είναι ο υπεύθυνος κύριος παθογενετικός µηχανισµός. Η ακριβής αιτιοπαθολογία του συνδρόµου ισχαιµίας – επαναιµάτωσης δεν έχει πλήρως ερευνηθεί. Η πειραµατικές µεταµοσχεύσεις ως τώρα δεν µπόρεσαν να αποµονώσουν την κλινική εικόνα της βλάβης ισχαιµίας – επαναιµάτωσης, όπως είναι η υποξία, η σοβαρή βλάβη της ενδοθηλιακής διαπερατότητας και το γενικευµένο κυψελιδικό οίδηµα. Η ερευνητική µας οµάδα όπως και πολλές άλλες διεθνώς, χρησιµοποίησε ως τώρα το µοντέλο µεταµόσχευσης ενός πνεύµονα από το ένα ζώο σε άλλο. Ο πρώτος στόχος µας ήταν να δηµιουργήσουµε ένα σταθερό και επαναλήψιµο πειραµατικό πρωτόκολλο που θα µπορούσε να αναπαράγει τις τοπικές και συστηµατικές εκδηλώσεις του συνδρόµου ισχαιµίας- επαναιµάτωσης χωρίς όµως τη συµµετοχή της παθολογίας της απόρριψης, διατηρώντας παράλληλα τους λιγότερους χειρουργικούς χειρισµούς στο µόσχευµα. Είναι γνωστό ότι κατά τις πνευµονικές µεταµοσχεύσεις σε πειραµατικά µοντέλα εµφανίζονται αλλαγές στη σύνθεση και λειτουργικότητα του επιφανειοδραστικού παράγοντα και επιπλέον εξαγγείωση πρωτεϊνών του πλάσµατος στην κυψελίδα µε αποτέλεσµα την επιπρόσθετη επιβάρυνση της λειτουργίας του επιφανειοδραστικού παράγοντα. Οι αλλαγές στον επιφανειοδραστικό παράγοντα κατά τις πνευµονικές µεταµοσχεύσεις έχει προταθεί ότι συµµετέχουν σηµαντικά στην παθοφυσιολογία των βλαβών που σχετίζονται µε τη µεταµόσχευση. Έτσι µπορούµε να υποθέσουµε ότι διαδικασίες που θα µπορούσαν να σταθεροποιήσουν το σύστηµα του επιφανειοδραστικού παράγοντα θα οδηγούσαν πιθανότερα σε βελτίωση της λειτουργίας του µοσχεύµατος. Έχει αποδειχτεί ότι ο εξωγενώς χορηγούµενος επιφανειοδραστικός παράγοντας µιµείται τις επιφανειοδραστικές ιδιότητες του ενδογενούς. Ο δεύτερος στόχος της µελέτης µας ήταν να εξετάσουµε αν η εξωγενής χορήγηση επιφανειοδραστικού παράγοντα θα βελτίωνε τις ιδιότητες 103 του µοσχεύµατος αλλά και ποια επίδραση θα είχε η µη χορήγηση ενός ανοσοδιεγερτικού παράγοντα του επιφανειοδραστικού παράγοντα όπως είναι το SP-A επί του συνδρόµου ισχαιµίας επαναιµάτωσης. Χρησιµοποιήσαµε 14 νεαρούς χοίρους µέσου βάρους 27(±3,5) Kg εφαρµόζοντας ένα µοντέλο αυτοµεταµόσχευσης πνεύµονα in situ. Ο πνεύµονας παρασκευάστηκε και εκπλύθηκε µέσω της πνευµονικής αρτηρίας ορθόδροµα χρησιµοποιώντας διάλυµα U Wisconsin. Οι πνευµονικές φλέβες αποκλείστηκαν µετά τη συµβολή τους επί του αριστερού κόλπου και το υγρό συντήρησης παροχετεύτηκε από αντιστόµειο στον αριστερό κόλπο. Το µόσχευµα παρέµεινε σε θερµοκρασία 4-8 0C για διάστηµα 3 ωρών, διατηρώντας την κεντρική θερµοκρασία ανάµεσα 37 και 38.50 C. Ακολούθησε επαναιµάτωση του µοσχεύµατος. Στην οµάδα ελέγχου (Β) χορηγήθηκε ελεύθερος SP-A επιφανειοδραστικός παράγοντας 1.5 ml/Kg µέσω βρογχοσκοπίου, πριν τη θωρακοτοµή. Τα πειραµατόζωα θυσιάστηκαν 3 ώρες µετά την επαναιµάτωση. Μετά από 3 ώρες από την επαναιµάτωση, (οµάδα Α vs. Β) η PVRI ήταν 447.80 dyne.sec-1cm-5m-2 (±66.8) vs. 249.51(p<.001) ενώ το NO(*p<0.05,**p<0.001), η EPO και η πνευµονική ευενδοτότητα (**p<0.002) διατηρήθηκαν στατιστικά σηµαντικά. Η µέση κυψελιδική επιφάνεια ήταν 5280.84 (4991.1) µm2 vs. 3997,89 (3284.70) µm2(p<0.005). Η ιστολογική µελέτη έδειξε µικρότερη διήθηση µικροφάγων και λεµφοκυττάρων στην οµάδα χορήγησης επιφανειοδραστικού παράγοντα στο τέλος της επαναιµάτωσης. Συµπεράσµατα Το νέο αυτό µοντέλο ετερόπλευρης µεταµόσχευσης πνεύµονα αποδείχθηκε αξιόπιστο και αναπαρήγαγε όλη την παθολογία του συνδρόµου ισχαιµίας επαναιµάτωσης, χωρίς την επίδραση των µηχανισµών απόρριψης. Επιπλέον αποδείχτηκε ότι η προθεραπεία του µοσχεύµατος µε εξωγενή επιφανειοδραστικό παράγοντα µειώνει τη βλάβη ισχαιµίας-επαναιµάτωσης διατηρώντας όχι µόνο την πνευµονική ευενδοτότητα αλλά και το δείκτη πνευµονικών αντιστάσεων. Επιπλέον οι συγκεντρώσεις του NO και η 104 105 δραστηριότητα του EPO διατηρήθηκαν καλύτερα, ενώ και η µορφολογία της κυψελίδας φαίνεται να διατηρείται σηµαντικά καλύτερα. / Lung transplantation is a well accepted treatment for patients with end stage pulmonary disease. Early graft dysfunction remains one of the major causes of early morbidity and mortality, with reperfusion injury (RI) being the most responsible mechanism. The exact pathophysiology of RI in lung transplantation has not been fully evaluated and understood. Experimental transplantation after cold storage has been so far unable to duplicate the complete clinical picture of RI, such as, hypoxia, severe impairment of endothelial permeability, and frank alveolar oedema. We, among others, in our previous experimental work with pigs, had being using a single lung transplantation model. Our first aim has been to create a steady and reproducible experimental protocol that could demonstrate several parameters associated with the mechanisms of reperfusion injury, including impaired gas exchange, elevated pulmonary vascular resistant, local and systemic aspects of the reperfusion syndrome, but without the interference of the pathology concerning acute graft rejection, and with the minimal possible surgical manipulation of the graft. Animal studies have shown that lung transplantation is followed by changes to both synthesis and activity of surfactant. Surfactant alterations have been suggested to contribute significantly to the pathophysiology of transplantation-associated lung injuries. Therefore, procedures that stabilize the pulmonary surfactant system may prove to be crucial for optimal lung preservation. It has been demonstrated that exogenous surfactant mimics the surface-tension-lowering properties of natural lung surfactant. The second purpose of our study was to evaluate whether differences exist in lung preservation after pre-treatment (prior to graft retrieval) of donor lung with surfactant. We postulated that surfactant would lead to an enhanced preservation of the organ. Therefore, we used Surfactant, Beractant which is a natural bovine lung extract containing phospholipids, neutral lipids, fatty acids, and surfactantassociated proteins SP-B and SP-C to which colfosceril palmitate, palmitic acid, and tripalmiting are added in order to standardise the suspension. It should be noted that it does not contain SP-A. Furthermore, we assessed the effect of surfactant pretreatment to lung haemodynamics, respiratory parameters, serum and BALF nitric oxide and EPO levels and the microscopic morphology of the alveolar. Methods: Fourteen young female white pigs, mean weight 27(±3.5) Kg were used in a newly developed autotransplantation model with in-situ cold ischemia. The hilum was dissected free and the pericardium opened. University of Wisconsin solution was used for lung preservation flushed in an antegrade fashion through the left pulmonary artery. Pulmonary veins were clamped proximal to their origin at the left atrium and vent was created just distally to the clamp. The left main bronchus was clamped with the lung left semi-inflated. Interlobar fissure tissue temperature was monitored and maintained at 4-8 0C, while core temperature was kept between 37 and 38.50 C. After 3 hours of cold ischaemia clamps were removed and the lung was reperfused. In the study group (B, n=6) free-SP-A surfactant 1.5 ml/Kg, was administrated into the left main bronchus via flexible bronchoscopy, prior to thoracotomy. Animals were sacrificed after 3 hours of graft reperfusion. Results: At the end of reperfusion, (Control vs. study group) PVRI was 447.80 dyn.sec-1cm-5m-2 (±66.8) vs. 249.51(p<.001) and lung compliance was 14.83 ml/cm H2O (SD 1.78) vs. 18.91 (SD 0.73) (**p<0.002) were adequately preserved. Serum eosinophil peroxidase (EPO) activity persentence change was 18.6 +/- 5.6 vs. 116+/-52 p=0.001. In contrast, EPO activity in BALF was 180 +/- 21 vs 73+/-8, p=0.01. Finally, NO concentration in BALF was 0.75 μM =+/- 0. 06 vs. 0.91 +/- 0.15 p< 0,05 and serum NO were adequately preserved (*p<0.05,**p<0.001). The mean alveoli surface area estimated by computerized morphometry were 5280.84 (4991.1) μm2 vs. 3997,89 (3284.70) μm2(p<0.005). Histology revealed less macrophage and lymphocyte accumulation in the study group at the end of reperfusion. Conclusions: This new model of unilateral lung auto transplantation with a cold storage of the graft, proved to be very reliable in reproducing all aspects of ischemia/reperfusion injury, and we, therefore, propose its use in experimental studies dealing with this yet to be fully clarified clinical entity. Moreover it has demonstrated that pre-treatment of the donor lung with a surfactant agent reduced the ischemia and reperfusion injury by means of maintaining lung compliance and resulting in less respiratory and haemodynamic disturbances. Also, alveoli surface area, alveoli morphology, EPO and NO concentration were better preserved. These data supports the hypothesis that donor lung pretreatment with surfuctant has a beneficial effect on graft properties. Further studies are required before discussing potential benefits in clinical practice.

Study evaluates adenosine, which is used as an adjunct to conventional reperfusion therapy (percutaneous coronary intervention, i.e. PCI), role in reducing the infarct size and preserving the left ventricular function in patients with acute myocardial infarction. During the study we examined patients with the left ventricular anterior wall acute myocardial infarction (AMI), when PCI and stenting were used for infarct-related artery (IRA) re-opening. Study evaluates influence of complementary use of adenosine in reducing the myocardial ischemic-reperfusion injury, the manifestation of slow-reflow or no-reflow phenomenon. The results of reperfusion therapy with adjunctive adenosine and without adenosine were analyzed in two homogeneous patient groups. By using new non-invasive imaging methods (single photon emission computer tomography, transthoracic Doppler echocardiography, dobutamine stress echocardiography) it was estimated, that adenosine preserves myocardial contractility and coronary flow reserve during the acute phase of myocardial infarction, reduces the final infarct size, improves the recovery of left ventricular global and segmental contractile function at five months follow-up. Those results are achieved due to adenosine impact on improving blood flow restoration not only in major coronary arteries, but also at microcirculatory level and ensuring of adequate and effective myocardial reperfusion. / Tyrime analizuojama adenozino, kuriuo papildoma įprastinė reperfuzinė terapija (perkutaninė koronarinė intervencija), įtaka mažinant infarkto dydį ir išsaugant kairiojo skilvelio funkciją pacientams, sergantiems ūminiu miokardo infarktu. Tyrimo metu siekta įvertinti PKI ir stentavimo būdu atveriant priekinės nusileidžiančios šakos spindį, kurio okliuzija sąlygojo kairiojo skilvelio priekinės sienelės ūminį miokardo infarktą, papildomai naudojamo adenozino įtaką mažinant miokardo išeminį-reperfuzinį pažeidimą, lėtos ar nutrūkusios tėkmės fenomeno pasireiškimą ir išplitimą. Reperfuzinės terapijos (PKI naudojant adenoziną ir PKI be adenozino) rezultatų ypatumai ir skirtumai palyginti dviejose homogeniškose pagal kontrolinius kintamuosius pacientų grupėse. Pasitelkus naujausius neinvazinius vaizdinimo metodus (miokardo perfuzijos radionuklidinę kompiuterinę tomografiją, transtorakalinę doplerinę echokardiografiją, dobutamino krūvio echokardiografiją) nustatyta, kad adenozinas, gerindamas kraujo tėkmės atstatymą ne tik stambiosiose vainikinėse arterijose, bet ir mikrocirkuliacijos grandyje, užtikrindamas adekvačią bei efektyvią miokardo reperfuziją, išsaugo miokardo kontraktilinį bei koronarinės tėkmės rezervus ūminio miokardo infarkto metu, mažina galutinį infarkto dydį, gerina bendrosios ir segmentinės kairiojo skilvelio kontraktilinės funkcijos atsistatymą praėjus 5 mėn. po reperfuzinio miokardo infarkto gydymo.

Tyrime analizuojama adenozino, kuriuo papildoma įprastinė reperfuzinė terapija (perkutaninė koronarinė intervencija), įtaka mažinant infarkto dydį ir išsaugant kairiojo skilvelio funkciją pacientams, sergantiems ūminiu miokardo infarktu. Tyrimo metu siekta įvertinti PKI ir stentavimo būdu atveriant priekinės nusileidžiančios šakos spindį, kurio okliuzija sąlygojo kairiojo skilvelio priekinės sienelės ūminį miokardo infarktą, papildomai naudojamo adenozino įtaką mažinant miokardo išeminį-reperfuzinį pažeidimą, lėtos ar nutrūkusios tėkmės fenomeno pasireiškimą ir išplitimą. Reperfuzinės terapijos (PKI naudojant adenoziną ir PKI be adenozino) rezultatų ypatumai ir skirtumai palyginti dviejose homogeniškose pagal kontrolinius kintamuosius pacientų grupėse. Pasitelkus naujausius neinvazinius vaizdinimo metodus (miokardo perfuzijos radionuklidinę kompiuterinę tomografiją, transtorakalinę doplerinę echokardiografiją, dobutamino krūvio echokardiografiją) nustatyta, kad adenozinas, gerindamas kraujo tėkmės atstatymą ne tik stambiosiose vainikinėse arterijose, bet ir mikrocirkuliacijos grandyje, užtikrindamas adekvačią bei efektyvią miokardo reperfuziją, išsaugo miokardo kontraktilinį bei koronarinės tėkmės rezervus ūminio miokardo infarkto metu, mažina galutinį infarkto dydį, gerina bendrosios ir segmentinės kairiojo skilvelio kontraktilinės funkcijos atsistatymą praėjus 5 mėn. po reperfuzinio miokardo infarkto gydymo. / Study evaluates adenosine, which is used as an adjunct to conventional reperfusion therapy (percutaneous coronary intervention, i.e. PCI), role in reducing the infarct size and preserving the left ventricular function in patients with acute myocardial infarction. During the study we examined patients with the left ventricular anterior wall acute myocardial infarction (AMI), when PCI and stenting were used for infarct-related artery (IRA) re-opening. Study evaluates influence of complementary use of adenosine in reducing the myocardial ischemic-reperfusion injury, the manifestation of slow-reflow or no-reflow phenomenon. The results of reperfusion therapy with adjunctive adenosine and without adenosine were analyzed in two homogeneous patient groups. By using new non-invasive imaging methods (single photon emission computer tomography, transthoracic Doppler echocardiography, dobutamine stress echocardiography) it was estimated, that adenosine preserves myocardial contractility and coronary flow reserve during the acute phase of myocardial infarction, reduces the final infarct size, improves the recovery of left ventricular global and segmental contractile function at five months follow-up. Those results are achieved due to adenosine impact on improving blood flow restoration not only in major coronary arteries, but also at microcirculatory level and ensuring of adequate and effective myocardial reperfusion.

No description available.

Ischemia caused by the disruption of blood flow results in kidney damage and dysfunction. This study investigated the effects of 30, 60 or 120 minutes of renal ischemia on the levels of glutathione (GSH), the major antioxidant inside cells. Kidneys from anesthetized female Lewis rats (9 months old) were clamped to induce ischemia and then homogenized and separated into cytosolic and mitochondria fractions by differential centrifugation. The levels of GSH and oxidized glutathione (GSSG) in the fractions were measured spectrophotometrically or by capillary electrophoresis. A significant reduction in GSH levels in the cytosol and mitochondria was seen only after the kidney underwent 60 minutes of ischemia. The significant decrease in GSH was accompanied by an increase in the GSSG/GSH ratio and an alteration in the glutathione redox ratio (i.e., GSH/total glutathione). This study demonstrates that an ischemic time of 60 minutes or longer is necessary to cause depletion of GSH levels in the rat kidney. / Department of Physiology and Health Science