Mechanisms of regenerative preconditioning in pigs with subtotal hepatectomies.

BACKGROUND: Portal vein occlusion shortly before extended hepatic resections has hepatoprotective properties, but its molecular effects have not been elucidated. We characterized the impact of regenerative preconditioning by portal vein embolization (PVE) on hepatic energy metabolism and cytokine expression. MATERIALS AND METHODS: About 90% hepatectomies were performed in normal pigs (Control) and in pigs that underwent a PVE 24 h before the surgery (n = 10/group). Blood biochemistry and coagulation, liver damage, liver function (ICG), hepatic content of adenine nucleotides, and hepatic expression of inflammatory mediators (RT-PCR and WB) were determined before the hepatectomy, 15 min, and 24 h later. RESULTS: All PVE and hepatectomies were successfully accomplished. The 90% hepatectomy resulted in: Immediate reduction of ATP, leading to persistent decreases of energy load and ATP/ADP ratio up to the 24-h time-point; and pro-inflammatory expression profile of cytokines in the remnant liver. Prior performance of PVE attenuated the bioenergetic alterations and prevented many of the changes in hepatic cytokine expression. CONCLUSIONS: Regenerative preconditioning by PVE improved hepatic energy metabolism and modulated inflammatory mediators in the remnant liver in pigs undergoing major hepatectomies, potentially contributing to its hepatoprotective effects.

INTRODUCCIÓN: la oclusión de la vena porta precoz antes de hepatectomías extendidas tiene propiedades hepatoprotectoras, pero sus efectos moleculares no se han aclarado. Caracterizamos el impacto del preacondicionamiento regenerativo por embolización de la vena porta (PVE) sobre el metabolismo energético hepático y la expresión de citocinas. MATERIALES Y MÉTODOS: Realizamos hepatectomías del 90% en cerdos (Control) y en cerdos sometidos a PVE 24 horas antes de la cirugía (n = 10/grupo). La bioquímica y la coagulación, el daño hepático, la función hepática (ICG), los nucleótidos de adenina y la expresión de mediadores inflamatorios (RT-PCR y WB) fueron determinado antes de la hepatectomía, quince minutos y 24 horas después. RESULTADOS: Las PVE y las hepatectomías se realizaron con éxito. La hepatectomía del 90% resultó en: una reducción del ATP, lo que disminuye la carga energética y la relación ATP/ADP a las 24 horas; y en la expresión de citocinas proinflamatorias. La realización previa de PVE atenuó las alteraciones bioenergéticas y evitó muchos de los cambios en la expresión de citocinas. CONCLUSIONES: El preacondicionamiento regenerativo con PVE mejoró el metabolismo energético y moduló los mediadores inflamatorios en el hígado remanente en cerdos sometidos a hepatectomías subtotales, contribuyendo potencialmente a sus efectos hepatoprotectores.

Akkermansia deficiency and mucin depletion are implicated in intestinal barrier dysfunction as earlier event in the development of inflammation in interleukin-10-deficient mice.

Background: Dysbiosis and mucin depletion are related with intestinal barrier dysfunction and seems to be an early pathophysiological event in inflammatory bowel disease (IBD). The objective of this work is to study these parameters in the natural history of colitis in IL-10 deficient mice (IL-10-/-). Methods: Wild type (WT) and IL-10-/-. mice were followed until sacrifice at 3, 5, 10, 20, 57, and 70 weeks. Body weight, colonic weight/length ratio and in vivo intestinal permeability were registered. Expression of inflammatory and adhesion molecules in the colon was explored by qPCR as Mucin-2 (MUC-2) and molecules involved in goblet cell maturation Interleukin-18 (IL-18) and WAP Four-Disulfide Core Domain 2 (WFDC2), the endoplasmic reticulum stress markers X-box-binding protein (Xbp-1) and Reticulon-4B (RTN-4B). Bacterial composition in feces and colonic mucosa was determined by massive sequencing of the V3-V4 regions of 16S rDNA gene. Results: IL-10-/- mice showed histological inflammation at weeks 20 and 57, but most notably the intestinal permeability was significantly higher from week 10. Concordantly, the number of goblet cells and expression of MUC-2, IL-18, WFDC2 and Xbp-1 were significantly lower in KO from week 10. Nevertheless, no significant differences were found in the mRNA expression of MUC-2 or Xbp-1 between both groups-derived colon organoids. Significant bacterial differences began at week 5, being the Akkermansia deficiency in KO the most relevant result. Conclusion: Gut microbiota alterations and mucin depletion are associated with early intestinal barrier dysfunction and precede overt gut inflammation in this animal model of IBD.

Histological inflammatory activity can predict endoscopic relapse in patients with ulcerative colitis who have achieved mucosal healing.

BACKGROUND AIMS: Current therapeutic goals in ulcerative colitis (UC) include clinical and endoscopic remission, named mucosal healing (MH). Despite MH, a proportion of patients suffer a clinical relapse, which has been related to histological inflammation. We aimed to identify which histopathological features or histopathological index cut-off was associated with endoscopic relapse (ER) in UC patients with MH. METHODS: Retrospective analysis of UC patients who underwent surveillance colonoscopy showing complete MH (endoscopic Mayo subscore=0) with random biopsies, and at least one more endoscopy along the follow-up. After a consensus meeting, expert pathologist performed histological assessment according to Simplified Geboes Score (SGS), Nancy Index (NI) and Robarts Histopathological Index (RHI). Other histopathological features were also evaluated. Patients were followed until ER or last endoscopy performed showing persistence of MH. RESULTS: A total of 95 patients (150 colonoscopies) were included. After mean follow-up of 31.2 months (SD 21.7), 33 patients (34.7%) suffered ER. Neutrophils in lamina propria (OR 2.6; P = 0.037), within the epithelium (OR 2.6; P = 0.03), SGS ≥3.1 (OR 2.6; P = 0.037), NI ≥2 (OR 2.6; P = 0.03) and RHI ≥5 (OR 2.6; P = 0.037) were associated with ER in univariate analysis. In multivariate analysis, eosinophils in the lamina propria (HR 2.5; P = 0.01) and clinical remission<12 months (HR 3.2; P = 0.002) were associated with ER. CONCLUSIONS: Histopathological findings in UC patients who have achieved endoscopic MH may predict ER. Standardized histopathology reports according to the presence of neutrophils, eosinophils or to defined cut-off of validated histopathologic indexes may represent a useful tool to predict ER and should be considered at therapeutic and surveillance decision process.

Association of visual and quantitative heterogeneity of 18F-FDG PET images with treatment response in locally advanced rectal cancer: A feasibility study.

BACKGROUND AND PURPOSE: Few tools are available to predict tumor response to treatment. This retrospective study assesses visual and automatic heterogeneity from 18F-FDG PET images as predictors of response in locally advanced rectal cancer. METHODS: This study included 37 LARC patients who underwent an 18F-FDG PET before their neoadjuvant therapy. One expert segmented the tumor from the PET images. Blinded to the patient´s outcome, two experts established by consensus a visual score for tumor heterogeneity. Metabolic and texture parameters were extracted from the tumor area. Multivariate binary logistic regression with cross-validation was used to estimate the clinical relevance of these features. Area under the ROC Curve (AUC) of each model was evaluated. Histopathological tumor regression grade was the ground-truth. RESULTS: Standard metabolic parameters could discriminate 50.1% of responders (AUC = 0.685). Visual heterogeneity classification showed correct assessment of the response in 75.4% of the sample (AUC = 0.759). Automatic quantitative evaluation of heterogeneity achieved a similar predictive capacity (73.1%, AUC = 0.815). CONCLUSION: A response prediction model in LARC based on tumor heterogeneity (assessed either visually or with automatic texture measurement) shows that texture features may complement the information provided by the metabolic parameters and increase prediction accuracy.

Comprehensive Characterization of a Porcine Model of The "Small-for-Flow" Syndrome.

INTRODUCTION: The term "Small-for-Flow" reflects the pathogenetic relevance of hepatic hemodynamics for the "Small-For-Size" syndrome and posthepatectomy liver failure. We aimed to characterize a large-animal model for studying the "Small-for-Flow" syndrome. METHODS: We performed subtotal (90%) hepatectomies in 10 female MiniPigs using a simplified transection technique with a tourniquet. Blood tests, hepatic and systemic hemodynamics, and hepatic function and histology were assessed before (Bas), 15 min (t-15 min) and 24 h (t-24 h) after the operation. Some pigs underwent computed tomography (CT) scans for hepatic volumetry (n = 4) and intracranial pressure (ICP) monitoring (n = 3). Postoperative care was performed in an intensive care unit environment. RESULTS: All hepatectomies were successfully performed, and hepatic volumetry confirmed liver remnant volumes of 9.2% [6.2-11.2]. The hepatectomy resulted in characteristic hepatic hemodynamic alterations, including portal hyperperfusion, relative decrease of hepatic arterial blood flow, and increased portal pressure (PP) and portal-systemic pressure gradient. The model reproduced major diagnostic features including the development of cholestasis, coagulopathy, encephalopathy with increased ICP, ascites, and renal failure, hyperdynamic circulation, and hyperlactatemia. Two animals (20%) died before t-24 h. Histological liver damage was observed at t-15 min and at t-24 h. The degree of histological damage at t-24 h correlated with intraoperative PP (r = 0.689, p = 0.028), hepatic arterial blood flow (r = 0.655, p = 0.040), and hepatic arterial pulsatility index (r = 0.724, p = 0.066). All animals with intraoperative PP > 20 mmHg presented liver damage at t-24 h. CONCLUSION: The present 90% hepatectomy porcine experimental model is a feasible and reproducible model for investigating the "Small-for-Flow" syndrome.

Chemotherapy Plus Bevacizumab as Neoadjuvant or Conversion Treatment in Patients with Colorectal Liver Metastases.

AIM: To evaluate the efficacy of chemotherapy plus bevacizumab as neoadjuvant or conversion treatment for colorectal liver metastases (CLM). PATIENTS AND METHODS: A retrospective chart review was carried out of 74 patients with CLM treated with neoadjuvant or conversion chemotherapy plus bevacizumab. RESULTS: The overall response rate was 63.4%. An optimal morphological response by computed tomography was reported in 35% of patients. The rate of complete resection was 71.6%. Complete or major pathological response (pR) was attained in 58.2%. The median overall survival (OS) was not reached. Median progression-free (PFS) and relapse-free (RFS) survival were 14.6 and 8.7 months. Among patients reaching an optimal pR, median OS was not reached (p=0.08), and a trend towards longer RFS and PFS was seen. CONCLUSION: Neoadjuvant or conversion chemotherapy with bevacizumab is an active and tolerable option for CLM with minimal post-surgery complications. Optimal pR is associated with a longer OS and a trend for prolonged PFS and RFS.

Preconditioning by portal vein embolization modulates hepatic hemodynamics and improves liver function in pigs with extended hepatectomy.

BACKGROUND: Portal vein embolization is performed weeks before extended hepatic resections to increase the future liver remnant and prevent posthepatectomy liver failure. Portal vein embolization performed closer to the operation also could be protective, but worsening of portal hyper-perfusion is a major concern. We determined the hepatic hemodynamic effects of a portal vein embolization performed 24 hours prior to hepatic operation. METHODS: An extended (90%) hepatectomy was performed in swine undergoing (portal vein embolization) or not undergoing (control) a portal vein embolization 24 hours earlier (n = 10/group). Blood tests, hepatic and systemic hemodynamics, hepatic function (plasma disappearance rate of indocyanine green), liver histology, and volumetry (computed tomographic scanning) were assessed before and after the hepatectomy. Hepatocyte proliferating cell nuclear antigen expression and hepatic gene expression also were evaluated. RESULTS: Swine in the control and portal vein embolization groups maintained stable systemic hemodynamics and developed similar increases of portal blood flow (302 ± 72% vs 486 ± 92%, P = .13). Portal pressure drastically increased in Controls (from 9.4 ± 1.3 mm Hg to 20.9 ± 1.4 mm Hg, P < .001), while being markedly attenuated in the portal vein embolization group (from 11.4 ± 1.5 mm Hg to 16.1 ± 1.3 mm Hg, P = .061). The procedure also improved the preservation of the hepatic artery blood flow, liver function, and periportal edema. These effects occurred in the absence of hepatocyte proliferation or hepatic growth and were associated with the induction of the vasoprotective gene Klf2. CONCLUSION: Portal vein embolization preconditioning represents a potential hepato-protective strategy for extended hepatic resections. Further preclinical studies should assess its medium-term effects, including survival. Our study also supports the relevance of hepatic hemodynamics as the main pathogenetic factor of post-hepatectomy liver failure.

Post-chemoradiation intraoperative electron-beam radiation therapy boost in resected locally advanced rectal cancer: long-term results focused on topographic pattern of locoregional relapse.

BACKGROUND: Patients with locally advanced rectal cancer (LARC) have a dismal prognosis. We investigated outcomes and risk factors for locoregional recurrence (LRR) in patients treated with preoperative chemoradiotherapy (CRT), surgery and IOERT. METHODS: A total of 335 patients with LARC [⩾cT3 93% and/or cN+ 69%) were studied. In multivariate analyses, risk factors for LRR, IFLR and OFLR were assessed. RESULTS: Median follow-up was 72.6 months (range, 4-205). In multivariate analysis distal margin distance ⩽10 mm [HR 2.46, p = 0.03], R1 resection [HR 5.06, p = 0.02], tumor regression grade 1-2 [HR 2.63, p = 0.05] and tumor grade 3 [HR 7.79, p < 0.001] were associated with an increased risk of LRR. A risk model was generated to determine a prognostic index for individual patients with LARC. CONCLUSIONS: Overall results after multimodality treatment of LARC are promising. Classification of risk factors for LRR has contributed to propose a prognostic index that could allow us to guide risk-adapted tailored treatment.

Clinical significance of VEGFR-2 and ¹8F-FDG PET/CT SUVmax pretreatment score in predicting the long-term outcome of patients with locally advanced rectal cancer treated with neoadjuvant therapy.

PURPOSE: Vascular endothelial growth factor receptor-2 (VEGFR-2), epidermal growth factor receptor-1 (EGFR), and cyclooxygenase-2 (COX-2) stimulate key processes involved in tumor progression and are important targets for cancer drugs. (18)F-FDG maximum standardized uptake value (SUVmax) is a marker of tumor metabolic activity. The purpose of this study was to measure SUVmax combined with VEGFR-2, EGFR and COX-2 proteins in pretreatment tumor biopsies from patients with locally advanced rectal cancer receiving intensive neoadjuvant treatment and to correlate the findings with clinical outcome. METHODS: VEGFR-2, EGFR and COX-2 were measured using the immunoreactive score (IRS). SUVmax (median 8.4) was quantified in tumors with molecular overexpression (IRS ≥3 + SUVmax ≥ 8.4 indicating active tumors; SUVmax <8.4 indicating inactive tumors). The Cox proportional hazards model was used to explore associations between tumor markers, disease-free survival (DFS) and overall survival (OS). RESULTS: The study group comprised 38 patients with a median follow-up of 69.3 months (range 4.5 - 92 months). Multivariate analysis showed that active tumors (overexpressing VEGFR-2, high SUVmax) were associated with worse DFS (HR 4.73, 95 % CI 1.18 - 22.17; p = 0.04) and OS (HR 4.28, 95 % CI 1.04 - 20.12; p = 0.05). CONCLUSION: Active tumors overexpressing VEGFR-2 are associated with a worse overall outcome in patients with rectal cancer treated with induction chemotherapy followed by pelvic chemoradiation and surgery. The optimal diagnostic cut-off level for this novel biomarker association should be investigated. Evaluation in a clinical trial is required to determine whether selected patients could benefit from a VEGFR-targeting drug.

[Influence of treatment of hepatocellular carcinoma before liver transplantation on post transplant tumor recurrence and survival]. / Influencia del tratamiento del hepatocarcinoma antes del trasplante hepático en la recurrencia tumoral y supervivencia postrasplante.

OBJECTIVES: To evaluate the effectiveness of treatment of hepatocellular carcinoma (HCC) before liver transplantation (LT) and its influence on survival and tumor recurrence in patients transplanted for HCC. PATIENTS AND METHODS: We included 67 liver transplant patients with a preoperative diagnosis of HCC and pathological confirmation in the native liver between January 2000 and October 2007. Treatment before LT was performed in 46 (68.7%) patients [radiofrequency ablation in 18, transarterial chemoembolization in 31 and percutaneous ethanol injection in two]. RESULTS: The median time between inclusion on the waiting list and LT was 4 months and was similar in treated and untreated patients. The median time between pre-transplantation locoregional therapy and LT was less than 6 months in 65.2% of the patients. Treated patients had better liver function (Child A 52.2 vs 19%; Child B 39.1 vs 33.3%; Child C 8.7 vs. 47.6%; p=0.001) and a higher proportion of total tumor size > 3 cm (59.1% vs 30%; p=0.031). Total tumor necrosis was observed in 26.1% of the patients, with no differences according to treatment modality or tumor size. Tumor recurrence occurred in six patients (9%). The median time between LT and tumor recurrence was 26.5 months with a subsequent median survival of 6.6 months. Overall survival was 83.5%, 69.9% and 59.5%, and tumor recurrence-free survival was 83.5%, 68.3% and 58% at 1, 3 and 5 years, respectively. Previous HCC treatment showed no influence on survival or tumor recurrence. Likewise, the grade of tumor necrosis was unrelated to overall survival or the probability of recurrence. CONCLUSION: Treatment of HCC before LT in patients with a waiting list time of less than 6 months does not appear to influence survival or tumor recurrence.