Σκοπός της μελέτης ήταν να εξετάσουμε, σε ένα πειραματικό μοντέλο πειραματικής ηπατεκτομής (70%) αφ’ ενός και παροδικής απόφραξης του ηπατοδωδεκαδακτυλικού συνδέσμου (χειρισμός Pringle) αφ’ ετέρου, το φαινόμενο της βακτηριακής μετακίνησης, της ενδοτοξιναιμίας, καθώς και τις μεταβολές οι οποίες συμβαίνουν στην εντερική χλωρίδα και τον εντερικό βλεννογόνο. Σε αυτά τα δύο μοντέλα προσπαθήσαμε κατ’ αρχήν να πιστοποιήσουμε την αυξημένη μετακίνηση των εντερικών βακτηρίων στους μεσεντέριους λεμφαδένες και την διαπίδυση ενδοτοξινών από τον αυλό του εντέρου στην πυλαία και την αορτή. Στα ίδια μοντέλα προσπαθήσαμε να αναστείλουμε τα ανωτέρω φαινόμενα με φαρμακολογικούς χειρισμούς, μελετώντας πρώτον τη χορήγηση λακτουλόζης από το στόμα, η οποία έχει την ικανότητα να δεσμεύει την ενδοτοξίνη και να σχηματίζει σύμπλεγμα που δεν απορροφάται από το έντερο, με σκοπό τη μείωση της ενδοαυλικής απορροφήσιμης ενδοτοξίνης και δεύτερον τη χορήγηση δυσαπορρόφητων αντιβιοτικών από το στόμα, με σκοπό την ποσοτική ελάττωση του πληθυσμού της μικροβιακής χλωρίδας στον αυλό του εντέρου. Τα αποτελέσματα κάθε φάσης της μελέτης της ηπατεκτομής (70%) και του χειρισμού Pringle είχαν ως εξής: Η ηπατεκτομή (70%), προάγει την εντερική βακτηριακή μετακίνηση στους μεσεντέριους λεμφαδένες και στο ήπαρ, αυξάνει την ενδοτοξιναιμία και επιφέρει ιστολογικές αλλαγές στο ύψος των λάχνων. Η χορήγηση λακτουλόζης δημιουργεί τις κατάλληλες συνθήκες που επιφέρουν την μείωση των θετικών καλλιεργειών ιδιαίτερα αυτών του ήπατος και ελαττώνει την ενδοτοξίνη στην πυλαία. Η αποστείρωση του εντέρου με τη χορήγηση δυσαπορρόφητων αντιβιοτικών, μειώνει την εντερική βακτηριακή μετακίνηση στους μεσεντέριους λεμφαδένες και την ενδοτοξιναιμία. Ο χειρισμός Pringle, προάγει την εντερική βακτηριακή μετακίνηση και την ενδοτοξιναιμία, ενώ η απόπτωση ελαττώνεται με την αποστείρωση του εντέρου και τη χορήγηση λακτουλόζης μόνο άμεσα μετά τον χειρισμό. Η εξασφάλιση της ανατομικής και λειτουργικής ακεραιότητας του εντερικού βλεννογόνου έχει ιδιαίτερη σημασία στη διατήρηση του βλεννογόνιου εντερικού φραγμού και αποτρέπει την ενδοτοξιναιμία και τη βακτηριακή μετακίνηση. Η αποκατάσταση της δομικής και λειτουργικής ακεραιότητας του εντερικού βλεννογόνου, στην εκτεταμένη ηπατεκτομή, με τη χορήγηση μη απορροφήσιμων αντιβιοτικών και λακτουλόζης, αναστέλλει σημαντικά τα ανωτέρω φαινόμενα. / The purpose of this study is to investigate on an experimental model of extended hepatectomy(70%) and temporary occlusion of the hepatoduodenal ligament (Pringle maneuver), the phenomenon of bacterial translocation, endotoxaemia as well as the changes that are taking place, both in the intestinal flora and intestinal mucosa. In both models we attempt to demonstrate the increase translocation of intestinal bacteria to mesenteric lymph nodes (MLNs) and increase of endotoxin in the systemic and portal circulation. Using the same models, we attempted to inhibit the above phenomena with pharmacological manipulation. We examined the decrease of the endotoxins translocation, by administering per.os lactulose, which has the property to bind the endotoxin formatting a nonabsorbable comlex in the gut lumen. We also investigated the effect of nonabsorbable antibiotics per. os on reducing the intestinal flora. Our results indicated that, extended hepatectomy (70%) increased translocation of intestinal bacteria to mesenteric lymph nodes and liver and increased the endotoxaemia inducing the decrease of intestinal villus height. The administering of lactulose created the proper conditions which decreased positive liver cultures and reduced the endotoxin concentrations in portal blood. Gut decontamination by administration of nonabsorbable antibiotics reduced the intestinal flora, the intestinal bacteria translocation to MLNs and endotoxaemia. Pringle maneuver promoted the intestinal bacterial translocation and endotoxaemia. Apoptosis decreases, by gut decontamination and administration of lactulose only immediately after Pringle maneuver. The anatomic and functional integrity reassurance, of intestinal mucosa, has strong significance for the preservation of intestinal mucosal barrier to prevent endotoxaemia and bacterial translocation. The structural and functional establishment of enteric mucosa integrity, after extended hepatectomy, by administration of nonabsorbable antibiotics and lactulose, inhibit considerably the above phenomena.

Η παρούσα διδακτορική διατριβή επιχειρεί να διερευνήσει την επίδραση της πειραματικής ηπατεκτομής στην δομή του εντερικού βλεννογόνου μελετώντας την απόπτωση και τον πολλαπλασιασμό των επιθηλιακών κυττάρων στις κρύπτες, τα επίπεδα ενδοτοξίνης στην πυλαία φλέβα και την αορτή, καθώς επίσης και τα επίπεδα του οξει-δωτικού stress. Μελετά επίσης τα επίπεδα του οξειδωτικού stress στο εναπομείναν ήπαρ. Επιπλέον, σε μια προσπάθεια θεραπευτικής παρέμ-βασης, διερευνήθηκε ο ρόλος των ρυθμιστικών εντερικών πεπτιδίων BBS και NT στις ανωτέρω παραμέτρους . Προηγούμενες μελέτες έχουν δείξει ότι τα πεπτίδια αυτά εξα-σκούν ένα ευρύ φάσμα δράσεων στον εντεροηπατικό άξονα και βελτι-ώνουν την ακεραιότητα του γαστρεντερικού βλεννογόνου έπειτα από την επίδραση διαφόρων βλαπτικών παραγόντων. Η απουσία χολής ενδοαυλικά, αποστερεί τον εντερικό βλεννο-γόνο, από τις βακτηριοστατικές, αντιενδοτοξινικές και τροφικές της ιδιότητες, οδηγώντας σε αύξηση των βακτηριδίων και της ενδοτοξίνης ενδοαυλικά και σε εντερική ατροφία. Οι μεταβολές αυτές προάγουν τη μετακίνηση βακτηρίων και ενδοτοξινών στην πυλαία φλέβα και ακο-λούθως, μέσω μιας κατασταλμένης εκκαθαριστικής ικανότητας των κυττάρων Kupffer εξαιτίας της μειωμένης μάζας τους, στη συστη-ματική κυκλοφορία. Η συστηματική ενδοτοξιναιμία ενεργοποιεί τη συστηματική φλεγμονώδη απάντηση, η οποία σχετίζεται με τη δυσλει-τουργία που αναπτύσσεται σε απομακρυσμένα όργανα, ενώ συνεισφέ-ρει και στην περαιτέρω επιδείνωση της λειτουργίας του εντερικού φραγμού και της ηπατικής βλάβης. Τα αποτελέσματα της παρούσας μελέτης επιβεβαίωσαν την παρουσία πυλαίας και συστηματικής ενδο-τοξιναιμίας σε πειραματική ηπατεκτομή. Η προκαλούμενη από την πειραματική ηπατεκτομή ατροφία του εντερικού βλεννογόνου τεκμη-ριώθηκε με μορφομετρική ανάλυση και με μετρήσεις του DNA και της πρωτεΐνης. ΄Ενας πιθανός μηχανισμός προαγωγής της ατροφίας του εντερικού βλεννογόνου είναι η διαταραχή της ισορροπίας μεταξύ κυτταρικού πολλαπλασιασμού και κυτταρικού θανάτου στις κρύπτες, με αύξηση της απόπτωσης και μείωση της μιτωτικής δραστηριότητας. Επιπλέον η πειραματική ηπατεκτομή οδήγησε τις εντερικές λειτουργί-ες σε μια κατάσταση χαμηλού οξειδωτικού stress όπως φαίνεται καθαρά από τη μείωση της υπεροξείδωσης των λιπιδίων και της οξει-δωμένης γλουταθειόνης (GSSG) καθώς και από την αύξηση της ανηγ-μένης γλουταθειόνης (GSG). Είναι άξιο παρατήρησης ότι το οξειδωτι-κό stress δεν φαίνεται να είναι το πρωταρχικό αίτιο της πρόκλησης κυτταρικής απόπτωσης και ατροφίας λαχνών που παρατηρείται μετά από μερική ηπατεκτομή, αν και αυτή η επέμβαση μειώνει το οξειδωτι-κό stress κάτω από το control. Από το άλλο μέρος αυτές οι επιδράσεις εξαλείφθηκαν υπό συνθήκες ακόμη πιο μειωμένου οξειδωτικού stress που προκλήθηκαν μετά την χορήγηση των ρυθμιστικών πεπτιδίων BBS και NT Τα ρυθμιστικά εντερικά πεπτίδια, BBS και NT, δρώντας είτε άμεσα, μέσω ειδικών υποδοχέων των επιθηλιακών κυττάρων του εντέ-ρου, είτε έμμεσα, βελτιώνοντας τη μικροκυκλοφορία του εντέρου, μείωσαν σημαντικά την απόπτωση και ανέστρεψαν την εντερική ατρο-φία. Η πρόληψη, από τα ρυθμιστικά πεπτίδια, των επαγόμενων από την ηπατεκτομή κυτταρικών και βιοχημικών μεταβολών του εντερικού βλεννογόνου, οδήγησε σε σημαντική μείωση της πυλαίας και συστη-ματικής ενδοτοξιναιμίας. Επιπλέον, η BBS και η NT, εξασκώντας αντιοξειδωτική δράση και στο ήπαρ, προστάτεψαν το εναπομείναν ήπαρ από δυο μείζονες παράγοντες ηπατικής βλάβης, που είναι το οξειδωτικό stress και η ενδοτοξιναιμία. Συμπερασματικά, τα αποτελέσματα της παρούσας μελέτης δείχ-νουν ότι η δυσλειτουργία του εντερικού φραγμού στην ηπατεκτομή σχετίζεται με την επαγωγή κυτταρικών και βιοχημικών μεταβολών στον εντερικό βλεννογόνο, οι οποίες χαρακτηρίζονται από πρόκληση οξειδωτικού stress και επαγωγή της απόπτωσης. Τα ρυθμιστικά εντε-ρικά πεπτίδια BBS και NT προλαμβάνοντας τις μεταβολές αυτές του εντερικού βλεννογόνου μειώνουν σημαντικά την πυλαία και συστημα-τική ενδοτοξιναιμία. Επίσης, εξασκούν προστατευτική δράση εναντίον του οξειδωτικού stress στο ήπαρ. Η συνδυασμένη ευεργετική επίδραση των ρυθμιστικών πεπτιδίων, τόσο στη δυσλειτουργία του εντερικού φραγμού και την ενδοτοξιναιμία, που ευθύνονται για την ανάπτυξη σηπτικών επιπλοκών και βλάβης απομακρυσμένων οργάνων, όσο και στο οξειδωτικό stress, εισηγούνται μια νέα θεραπευτική προσέγγιση στην ηπατεκτομή. / This doctoral thesis explores the effect of experimental hepatectomy on the structure of the intestinal mucosa by studying apoptosis and proliferation of epithelial cells in crypts, endotoxin levels in portal vein and aorta, as well as levels of oxidative stress. It also investigates the level of oxidative stress on the remaining liver tissue. In addition, in an attempt of therapeutical approach, the role of the regulatory intestinal peptides BBS and NT in the above parameters has also been evaluated. Previous studies have demonstrate that the above peptides present a wide range of actions on the intestinal-liver axis, thus improving integrity of the gastrointestinal mucosa after it has been affected by various harmful factors. Intestinal mucosa in the absence of bile in the lumen lacks its bacteriostatic, anti-endotoxin and trophic effects, leading in a raise of bacteria and endotoxin in the lumen as well as intestinal atrophy. These changes are promoting bacteria and endotoxin translocation to the portal vein and from there, to the systematic circulation, a procedure augmented by the supression of the cleaning ability of Kuppfer cells due to their reduced mass in hepatectomy. Systemic endotoxinaemia activates the systematic inflammatory response (SIR) related to the dysfunction of distal organs, and contributing to further damage to the mucosal barrier and the liver. This study confirmed the presence of portal and systemic endotoxinaimia in experimental hepatectomy. The subsequent atrophy of the intestinal mucosa has been documented with morphologic analyses as well as DNA and protein measurements. A possible explanation of the observed atrophy might be disturbance in balance between cellular proliferation and cellular death in the crypts by increased apoptosis and decreased mitotic activity. In addition, experimental hepatectomy led the intestinal functions in a state of low oxidative stress, as it is clearly shown by the decrease of lipid peroxidation and oxidized glutathione (GSSG), and the increase of glutathione (GSH). Interestingly enough, oxidative stress does not seem to be the primary cause of cellular apoptosis and decreased cell proliferation in the crypts (leading to mucosa atrophy), which are observed after partial hepatectomy, although this operation decreased oxidative stress below the control levels. On the other hand, these effects are prevented at more decreased levels of oxidative sress induced by the regulatory intestinal peptides BBS and NT. BBS and NT may act either directly, through specific receptors of the intestinal epithelial cells, or indirectly, by improving the intestinal microcirculation, leading to reversal of intestinal atrophy. Prevention, by these peptides, of the hepatectomy induced cellular and biochemical changes in the intestinal mucosa led to significantly reduced portal and systematic endotoxinaemia. In addition, BBS and NT, through antioxidative action to the liver, protected the remaining liver tissue from two major factors of liver lesions: oxidative stress and endotoxinaimia. Concluding, the results of this study show that dysfunction of the intestinal mucosa barrier in the hepatectomy is associated with the induction of cellular and biochemical changes in the intestinal mucosa, which are characterized by the promotion of oxidative stress and apoptosis. The regulatory intestinal peptides BBS and NT preventing these changes in the intestinal mucosa are significantly reducing portal and systematic endotoxinaimia. They also act by protecting against oxidative stress in the liver. This combined beneficial effect of these peptides, both in the dysfunction of the intestinal mucosa barrier and endotoxinaimia, which are responsible for the development of septic complications and distal organ lesions as well as in oxidative stress, might suggests a new therapeutical approach in hepatectomy.

No description available.

The proprotein convertase subtilisin/kexin type 9, PCSK9, belongs to the proprotein convertase (PC) family. Human mutations in the gene encoding PCSK9 lead to either familial hyper- or hypocholesterolemia, resulting from a gain or loss of function, respectively. Mice lacking PCSK9 are viable and show a 42% decrease in plasma cholesterol levels. The enzyme triggers the degradation of the low density lipoprotein receptor (LDLR) through a partially unknown mechanism. / PCSK9 is very abundant in the liver and intestine during development and adulthood. Hepatocytes have a capacity to reproduce themselves and, upon injury, can repopulate the liver. For a better understanding of the role of PCSK9 in the liver, partial hepatectomy was performed on Pcsk9 +/+, Pcsk9+/- and Pcsk9-/- mice. The absence of PCSK9 resulted in defective liver regeneration, while wild type (WT) and heterozygous mice had no phenotype. Regeneration defects could be prevented by a high cholesterol diet. PCSK9 deficiency, by contributing to maintaining low circulating cholesterol levels may thus hamper liver regeneration. This knowledge is critical for the analysis of future PCSK9 inhibitors expected to be developed in the near future. / Key words. Proprotein convertase subtilisin/kexin 9 (PCSK9), a familial hyper- or hypocholesterolemia, low density lipoprotein receptor, knockout mouse model, partial hepatectomy.

Made available in DSpace on 2014-12-17T14:14:01Z (GMT). No. of bitstreams: 1 MariliaDFC_DISSERT.pdf: 4078841 bytes, checksum: c83e843adb7bb22ae42c72221a9ff0d5 (MD5) Previous issue date: 2012-10-30 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / This study investigated the influence of partial colectomy associated with hepatectomy on the biodistribution of the 99mTc-phytate, on metabolic parameters, as well as labeling and morphology of red blood cells. Wistar rats were distributed into three groups (each with 6), nominated as colectomy, colectomy+hepatectomy and sham. In the 30th postoperative day all rats were injected with 99mTc-phytate 0.1mL i.v. (radioactivity 0.66 MBq). After 15 minutes, liver sample was harvested and weighed. Percentage radioactivity per gram of tissue (%ATI/g) was determined using an automatic gamma-counter. Serum AST, ALT, alkaline phosphatase and red blood cells labeling were determined. The liver %ATI/g and red blood cells labeling were lower in colectomy and colectomy+hepatectomy rats than in sham rats (p <0.05), and no difference was detected comparing the colectomy and colectomy+hepatectomy groups. Red blood cells morphology did not differ among groups. Serum levels of AST, ALT and alkaline fosfatase were significantly higher in colectomy+hepatectomy than in colectomy rats (p<0.001). Hepatectomy associated with colectomy lowered the uptake of radiopharmaceutical in liver and in red blood cells in rats, coinciding with changes in liver enzymatic activity / Este trabalho trata de investiga??o sobre a influ?ncia da colectomia associada ? hepatectomia parcial, na biodistribui??o do fitato-99mTcO4, na marca??o e morfologia de hem?cias e par?metros metab?licos da fun??o hep?tica. Dezoito ratos Wistar foram distribu?dos em tr?s grupos (seis animais cada), denominados: colectomia, colectomia+hepatectomia e sham. No primeiro grupo os animais foram submetidos a uma colectomia direita, no segundo foram submetidos ao mesmo procedimento por?m associou-se uma hepatectomia esquerda e no terceiro houve apenas realiza??o de uma laparotomia e leve manipula??o de al?as intestinais. No trig?simo dia p?s-operat?rio, foi feita inje??o de 0,1 mililitro intravenoso de fitato- 99mTcO4 (radioatividade 0,66 MBq) em todos os animais. Ap?s quinze minutos, uma amostra de f?gado foi colhida e pesada. O percentual de radioatividade por grama de tecido (%AIT/g) foi determinado no f?gado e hem?cias usando-se um contador gama autom?tico. Dosagem s?rica de alanina aminotransferase (ALT), aspartato aminotransferase (AST), fosfatase alcalina (FA), morfologia e marca??o de hem?cias com pertecnetato foram determinadas. O %AIT/g no f?gado e nas hem?cias foi menor nos animais dos grupos colectomia e colectomia+hepatectomia do que no grupo sham (p<0,05; teste de Tukey). Nenhuma diferen?a foi detectada comparando os grupos colectomia e colectomia + hepatectomia. A morfologia das hem?cias n?o diferiu entre os 3 grupos. Os n?veis s?ricos de AST, ALT e FA foram significativamente maiores no grupo colectomia+hepatectomia do que no grupo colectomia (p<0,001). Em conclus?o, a colectomia associada a hepatectomia contribuiu para reduzir a capta??o de radiof?rmaco no f?gado e hem?cias de ratos, coincidindo com altera??es na atividade enzim?tica do f?gado

O fígado é um órgão importante para se analisar como o animal reage a agressões químicas. Um dos métodos utlizado para estudar a regeneração hepática é a hepatectomia parcial (HP). Assim, nosso objetivo foi verificar a influência da hepatectomia de 30% e de 70% sobre a taxa de proliferação das células hepática medida pela incorporação de BrdU na região da incisão e no resto do fígado e a proliferação de ductos biliares e de células epiteliais pré-ductulares biliares (CEPDBs) com o uso de uma combinação de 2 anticorpos específicos para citoqueratinas humanas, AE1/AE3. O pico de proliferação nos animais que sofreram HP de 30% do parênquima hepático deu-se após 1 dia da cirurgia enquanto que os animais que sofreram a HP de 70% o pico ocorreu no terceiro dia após a cirurgia.O índice de proliferação foi semelhante para a região próxima ou distante do corte. Para ambas as HP não houve diferença na regeneração do tecido retirado próximo ou distante da área de incisão. Nas regiões distantes da HP havia maior número de ductos havendo o pico do número de ductos coincidindo com o pico de proliferação celular de ambas as HP. Depois da HP o número de CEPDBs cresce consideravelmente. Os pico de proliferação também ocorreram no primeiro e terceiro dia para a HP de 30% e de 70% respectivamente, sendo mais altos na região distante do corte. Assim, durante a regeneração do fígado de C. gariepinus ocorre hiperplasia compensatória por proliferação de hepatócitos, de ductos biliares e de CEPDBs. A hepatectomia de 30% gerou uma resposta regenerativa intensa e é menos traumática para o animal, a região distante do corte reage mais intensamente que a região próxima do corte no que se refere aos ductos biliares e as CEPDBs. / The liver is an important organ in studies aimed to the verification of animals reactions to chemical injuries. The partial hepatectomy (PH) is one of the methods that are usually employed in hepatic regeneration experiments. Our objectives in this work were to verify the influence of 30% and 70% PH on the hepatic cells proliferation index as it is measured by BrdU nuclear uptake in two regions: close to the hepatic surgery region and in a farther region. The biliary ducts and bile preductular epithelial cells (BPDECs) proliferation was quantified with a combination of two antibodies against the human cytokeratins AE1/AE3. The proliferation index peak in 30% hepatectomy animals occurred one day after the surgery, but in 70% hepatectomy animals the peak was only observed after three days from the surgery. Differences between the proliferation index of the close and the far region were not observed and likewise histological differences were absent. In the regions far from the PH site more biliary ducts were counted than in closer regions, but the peaks were coincident in both regions with the hepatocytes proliferation index. It was also observed that the quantity of BPDECs increased. The peaks occurred in the first and third days for the 30% and 70% PH respectively, and both peaks were higher in the region far from the PH site. We may conclude that C. gariepinus liver regeneration after 30% and 70% PH occurs by means of compensatory hyperplasia by hepatocytes, biliary ducts and BPDECs proliferation. The 30% HP stimulated a strong regenerative response and is less traumatic to the animals. The regions far from the PH site reacts more intensely that the close region concerning the stimulation of biliary ducts and BPDECs proliferation.

Submitted by Rosangela Silva (rosangela.silva3@unioeste.br) on 2018-05-22T20:11:58Z No. of bitstreams: 2 Luis César Bredt.pdf: 2819596 bytes, checksum: e18996972cd3e27519b13782d1d376bc (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Made available in DSpace on 2018-05-22T20:11:58Z (GMT). No. of bitstreams: 2 Luis César Bredt.pdf: 2819596 bytes, checksum: e18996972cd3e27519b13782d1d376bc (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Previous issue date: 2017-03-03 / This research aims to identify risk factors for the occurrence of acute kidney injury (AKI) in the postoperative period of partial hepatectomies. Methods: Retrospective analysis of 446 consecutive resections in 405 patients, analyzing clinical characteristics, preoperative laboratory data, intraoperative data, and postoperative laboratory data and clinical evolution. Adopting the International Club of Ascites (ICA) criteria for the definition of AKI, potential predictors of AKI by logistic regression were identified. Results: Of the total 446 partial liver resections, postoperative AKI occurred in 80 cases (17.9%). Identified predictors of AKI were: non-dialytic chronic kidney injury (CKI), biliary obstruction, the Model for End-Stage Liver Disease (MELD) score, the extent of hepatic resection, the occurrence of intraoperative hemodynamic instability, post-hepatectomy haemorrhage (PHH), and postoperative sepsis. Conclusion: The MELD score, the presence of non-dialytic CKI and biliary obstruction in the preoperative period, and perioperative hemodynamics instability, bleeding, and sepsis are risk factors for the occurrence of AKI in patients that underwent partial hepatectomy. / Atualmente, a hepatectomia parcial é o tratamento de escolha para uma grande variedade de patologias hepatobiliares. Dentre as possíveis complicações das hepatectomias parciais, a injúria renal aguda (IRA) deve ser considerada como uma importante causa de aumento da morbidade e mortalidade pós-operatória. Contudo, existem dados limitados na literatura médica quanto à sua real incidência e relevância clínica. Além disto, não existe uma padronização da definição de IRA no pós-operatório de hepatectomias parcias, com vários critérios diagnósticos propostos nas publicações sobre o assunto. Objetivo: Esta pesquisa tem o objetivo de identificar fatores de risco para a ocorrência de IRA no pós-operatório de hepatectomias parciais. Métodos: Por análise retrospectiva de 446 ressecções consecutivas em 405 pacientes, foram analisadas características clínicas, dados laboratoriais pré-operatórios, dados intra- operatórios e evolução clínico-laboratorial pós-operatória, e adotando os critérios do “International Club of Ascites” (ICA) para definição de IRA, foram analisados os potenciais preditores de IRA por regressão logística. Resultados: Do total de 446 ressecções hepáticas, a IRA pós-operatória ocorreu em 80 casos (17,9%). Foram fatores preditores de IRA: a IRC não-dialítica, obstrução biliar, o índice do “Model for End-Stage Liver Disease” (MELD), a ocorrência de instabilidade hemodinâmica intra- operatória, o porte da ressecção hepática, a hemorragia pós-hepatectomia, e a sepsis pós-operatória. Conclusão: O índice de MELD, a presença de IRC não-dialítica, obstrução biliar pré-operatória, o sangramento excessivo peri-operatório e a instalação de sepsis no período pós- operatório foram fatores de risco para a ocorrência de IRA em pacientes submetidos à hepatectomia parcial.

Ressecções hepáticas regradas baseiam-se em alguns princípios técnicos básicos, como controle vascular, delineamento isquêmico das áreas a serem ressecadas e preservação máxima de parênquima. Eles são alcançados através do acesso intrahepático aos pedículos glissonianos, que se baseia na abordagem dos segmentos hepáticos através do acesso aos pedículos dentro do fígado. Com pequenas incisões sobre pontos de reparo anatômicos bem definidos são acessados pedículos correspondentes aos segmentos a serem ressecados, tornando desnecessárias dissecções extensas do parênquima hepático.Neste estudo, parâmetros anatômicos relacionados à técnica de acesso intra-hepático aos pedículos glissonianos foram estudados em cadáveres com o fígado in loco. Ele propiciou a determinação precisa de pontos de reparo confiáveis e simples a serem utilizados durante estes procedimentos.Foram estudados 37 fígados provenientes de cadáveres adultos. Vinte e cinco cadáveres eram do sexo masculino e doze do sexo feminino. Foram excluídos cadáveres que tivessem qualquer fator que alterasse a anatomia original do andar superior do abdome e fígados com aspecto cirrótico. As aferições realizadas foram realizadas com instrumentos de precisão. Os dados obtidos foram expressos em média ± desvio padrão. Os indivíduos foram então divididos em grupos de acordo com gênero e peso do fígado e os grupos foram comparados estatisticamente através do teste t de Student. Setenta por cento dos cadáveres apresentavam veia hepática direita acessória, sendo este achado muito superior ao encontrado na literatura. O diâmetro médio deste vaso, quando presente, foi de 6,8 mm. As veias hepáticas média e esquerda apresentavam tronco comum em direção à veia cava em 51% dos casos, valor menor do que o habitualmente encontrado na literatura.Em 70% dos fígados a fissura de Gans encontrava-se aberta. Nestes, 80% continha o pedículo do segmento 6. A ponte entre os segmentos 3 e 4 encontrava-se aberta em 41% dos casos.O diâmetro médio do pedículo esquerdo foi de 28,2 mm, enquanto o do direito foi de 26,8 mm.A distância média entre a bifurcação do tronco portal e a inserção caudal do ligamento de Arantius foi de 32,9 mm. Esta distância é importante na realização do acesso intra-hepático a pedículos esquerdos. A distância média entre a bifurcação do tronco portal principal e a do pedículo direito foi de 26,2 mm. Este valor deve ser levado em consideração no acesso aos pedículos do fígado direito.A distância máxima observada entre a placa hilar e a bifurcação do tronco portal representa quanto se deve aprofundar na placa hilar para acesso dos pedículos direito e esquerdo e foi de 7 mm.Não foi observada diferença estatisticamente significativa em praticamente todos os parâmetros avaliados quando comparados os grupos divididos de acordo com gênero e peso do fígado. Isso demonstra a consistência dos parâmetros relacionados à realização do acesso intra-hepático aos pedículos glissonianos, garantindo reprodutibilidade ao método.Os resultados obtidos tornaram possíveis grandes avanços técnicos na realização de hepatectomias abertas ou laparoscópicas com acesso intra-hepático aos pedículos glissonianos, e resultaram em uma série de dados anatômicos que podem guiar cirurgiões de modo a evitar acidentes e tornar mais fácil sua execução / Anatomical liver resections are based on some basic technical principles such as vascular control, ischemic delineation of areas to be resected and maximum parenchymal preservation. Those are achieved by the intrahepatic glissonian approach, which consists in accessing the pedicles of hepatic segments to be resected within the hepatic parenchyma. Small incisions on well-defined anatomical landmarks are performed to approach the desired pedicles, making extensive dissection of the liver parenchyma unnecessary.In this study, anatomical parameters related to the intrahepatic glissonian approach to hepatic pedicles were studied in cadavers with the liver in loco. It allowed the accurate determination of anatomical landmarks that are reliable and easy to be used.Thirty-seven livers from adult cadavers were studied. Twenty-five cadavers were male and twelve female. Corpses that had any factor that altered the original anatomy of the upper abdomen and cirrhotic livers were excluded. The measurementswere performed with precision instruments. Data were expressed as mean ± standard deviation. The subjects were divided into groups according to gender and liver weight and the groups were compared statistically by the Student t test.Seventy percent of the cadavers presented an accessory right hepatic vein, much more frequent than previously reported in the literature. The average diameter of the vesselwas 6.8 mm. The middle and left hepatic veins presented a common trunk in 51% of cases, lower than typically found in the literature.In 70% of livers there was a patent incisura dextra of Gans. When present, 80% contained the pedicle of segment 6. There was an open hepatic bridge between segments 3 and 4 in 41% of cases.The mean diameter of the left pedicle was 28.2 mm, while the mean diameter of the right pedicle was 26.8 mm.The mean distance between the bifurcation of the main portal trunk and the caudal insertion of Arantius ligament was 32.9 mm. This distance is important in achieving the intrahepatic access to left pedicles. The mean distance between the bifurcation of the main portal trunk and the right pedicle was 26.2 mm. This value should be taken into consideration when approaching pedicles of the right liver.The maximum distance between the hilar plate and the bifurcation of the main portal trunk was 7 mm. It represents how deep one should enter the hepatic parenchyma through the hilar plate in order to approach the right and left pedicles.No statistically significant difference was observed in virtually all parameters when groups divided according to gender and liver weight were compared. This demonstrates the consistency of the anatomical parameters related to the intrahepatic glissonian approach, ensuring reproducibility to the method. Theresults obtained in this study made possible major technical advances in the realization of open and laparoscopic hepatectomies with intrahepatic glissonian approach to hepatic pedicles, and resulted in a series of anatomical data that can guide surgeons to prevent accidents and make it easier to accomplish safe and effective procedures

O fígado é um órgão importante para se analisar como o animal reage a agressões químicas. Um dos métodos utlizado para estudar a regeneração hepática é a hepatectomia parcial (HP). Assim, nosso objetivo foi verificar a influência da hepatectomia de 30% e de 70% sobre a taxa de proliferação das células hepática medida pela incorporação de BrdU na região da incisão e no resto do fígado e a proliferação de ductos biliares e de células epiteliais pré-ductulares biliares (CEPDBs) com o uso de uma combinação de 2 anticorpos específicos para citoqueratinas humanas, AE1/AE3. O pico de proliferação nos animais que sofreram HP de 30% do parênquima hepático deu-se após 1 dia da cirurgia enquanto que os animais que sofreram a HP de 70% o pico ocorreu no terceiro dia após a cirurgia.O índice de proliferação foi semelhante para a região próxima ou distante do corte. Para ambas as HP não houve diferença na regeneração do tecido retirado próximo ou distante da área de incisão. Nas regiões distantes da HP havia maior número de ductos havendo o pico do número de ductos coincidindo com o pico de proliferação celular de ambas as HP. Depois da HP o número de CEPDBs cresce consideravelmente. Os pico de proliferação também ocorreram no primeiro e terceiro dia para a HP de 30% e de 70% respectivamente, sendo mais altos na região distante do corte. Assim, durante a regeneração do fígado de C. gariepinus ocorre hiperplasia compensatória por proliferação de hepatócitos, de ductos biliares e de CEPDBs. A hepatectomia de 30% gerou uma resposta regenerativa intensa e é menos traumática para o animal, a região distante do corte reage mais intensamente que a região próxima do corte no que se refere aos ductos biliares e as CEPDBs. / The liver is an important organ in studies aimed to the verification of animals reactions to chemical injuries. The partial hepatectomy (PH) is one of the methods that are usually employed in hepatic regeneration experiments. Our objectives in this work were to verify the influence of 30% and 70% PH on the hepatic cells proliferation index as it is measured by BrdU nuclear uptake in two regions: close to the hepatic surgery region and in a farther region. The biliary ducts and bile preductular epithelial cells (BPDECs) proliferation was quantified with a combination of two antibodies against the human cytokeratins AE1/AE3. The proliferation index peak in 30% hepatectomy animals occurred one day after the surgery, but in 70% hepatectomy animals the peak was only observed after three days from the surgery. Differences between the proliferation index of the close and the far region were not observed and likewise histological differences were absent. In the regions far from the PH site more biliary ducts were counted than in closer regions, but the peaks were coincident in both regions with the hepatocytes proliferation index. It was also observed that the quantity of BPDECs increased. The peaks occurred in the first and third days for the 30% and 70% PH respectively, and both peaks were higher in the region far from the PH site. We may conclude that C. gariepinus liver regeneration after 30% and 70% PH occurs by means of compensatory hyperplasia by hepatocytes, biliary ducts and BPDECs proliferation. The 30% HP stimulated a strong regenerative response and is less traumatic to the animals. The regions far from the PH site reacts more intensely that the close region concerning the stimulation of biliary ducts and BPDECs proliferation.

Partial hepatectomy (PH) is a treatment of choice for patients suffering from early stage hepatocellular carcinoma (HCC). Ablation of large proportion of the liver is rendered possible because of the ability of the liver to regenerate. Yet, a significant number of patients will experience recursion of the disease. Such relapses are unfortunately rather frequent and constitute a bad prognosis. The development of new strategies aiming at reducing the risk of recursion of HCC is thus a paramount element of the surgery-based treatment. Some previous studies have proposed that the regenerative process as well as the fate of the immune cells during the liver regeneration process is linked to this recurrence phenomenon.In this study, we investigated the impact of PH on HCC development in a pre-clinical murine model. We implanted Hepa1-6 hepatocarcinoma cells (a murine hepatocarcinoma cell line) directly in the liver of mice and compared a non-resected group with a group undergoing 40% PH one week following tumor implantation. Analysis were relying on bioluminescence imaging and flow cytometry. We demonstrated that liver regeneration increases tumoral proliferation. This proliferation was associated with a reduction in the number of liver resident macrophages, i.e. Kupffer cells (KC). KC anti-tumoral activity was also proved using conditional ablation model. We further studied the mechanisms leading to this disappearance and demonstrated that, under normal regeneration conditions, PH-induced KC number reduction was dependent on tumor necrosis factor-α (TNF-α), receptor interacting protein kinase (RIPK) 3 and caspase-8 activation whereas interleukin (IL)-6 acted as a KC pro- survival signal. In mice with previous Hepa 1-6 encounter, the KC reduction changed toward a TNF-α-RIPK3-caspase-1 activation. This data suggest a switch from apoptosis to pyroptosis induction in KC following PH. Moreover, KC disappearance associated with caspase-1 activity induced the recruitment of monocyte derived cells that are beneficial for tumor growth while caspase-8 dependent reduction did not, underlying the importance of macrophages activated death-pathway in regulating the anti-tumoral immune response. Our results show the necessity for comprehensive multidisciplinary treatment approach following PH and propose new targets in order to reduce the relapse of the disease occurring after surgery. / Doctorat en Sciences biomédicales et pharmaceutiques (Médecine) / info:eu-repo/semantics/nonPublished