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Dive into the research topics where Pedro Pimentel-Nunes is active.

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Featured researches published by Pedro Pimentel-Nunes.


Endoscopy | 2012

Management of precancerous conditions and lesions in the stomach (MAPS): guideline from the European Society of Gastrointestinal Endoscopy (ESGE), European Helicobacter Study Group (EHSG), European Society of Pathology (ESP), and the Sociedade Portuguesa de Endoscopia Digestiva (SPED)

Mário Dinis-Ribeiro; Miguel Areia; A. C. de Vries; Ricardo Marcos-Pinto; M. Monteiro-Soares; A. O’Connor; Cidália Dionísio Pereira; Pedro Pimentel-Nunes; Rui Correia; Arzu Ensari; Jean-Marc Dumonceau; José Carlos Machado; Guilherme Macedo; Peter Malfertheiner; Tamara Matysiak-Budnik; Francis Mégraud; K. Miki; Colm O’Morain; Richard M. Peek; Thierry Ponchon; Ari Ristimäki; B. Rembacken; Fátima Carneiro; E. J. Kuipers

Atrophic gastritis, intestinal metaplasia, and epithelial dysplasia of the stomach are common and are associated with an increased risk for gastric cancer. In the absence of guidelines, there is wide disparity in the management of patients with these premalignant conditions. The European Society of Gastrointestinal Endoscopy (ESGE), the European Helicobacter Study Group (EHSG), the European Society of Pathology (ESP) and the Sociedade Portuguesa de Endoscopia Digestiva (SPED) have therefore combined efforts to develop evidence-based guidelines on the management of patients with precancerous conditions and lesions of the stomach (termed MAPS). A multidisciplinary group of 63 experts from 24 countries developed these recommendations by means of repeat online voting and a meeting in June 2011 in Porto, Portugal. The recommendations emphasize the increased cancer risk in patients with gastric atrophy and metaplasia, and the need for adequate staging in the case of high grade dysplasia, and they focus on treatment and surveillance indications and methods.


Endoscopy | 2015

Endoscopic submucosal dissection: European Society of Gastrointestinal Endoscopy (ESGE) Guideline

Pedro Pimentel-Nunes; Mário Dinis-Ribeiro; Thierry Ponchon; Alessandro Repici; Michael Vieth; De Ceglie; Arnaldo Amato; F Berr; Pradeep Bhandari; Andrzej Białek; Massimo Conio; Jelle Haringsma; Cord Langner; Søren Meisner; Helmut Messmann; Mario Morino; Horst Neuhaus; Hubert Piessevaux; Cesare Hassan; Pierre Henri Deprez

UNLABELLED This Guideline is an official statement of the European Society of Gastrointestinal Endoscopy (ESGE). The Grading of Recommendations Assessment, Development, and Evaluation (GRADE) system 1 2 was adopted to define the strength of recommendations and the quality of evidence. MAIN RECOMMENDATIONS 1 ESGE recommends endoscopic en bloc resection for superficial esophageal squamous cell cancers (SCCs), excluding those with obvious submucosal involvement (strong recommendation, moderate quality evidence). Endoscopic mucosal resection (EMR) may be considered in such lesions when they are smaller than 10 mm if en bloc resection can be assured. However, ESGE recommends endoscopic submucosal dissection (ESD) as the first option, mainly to provide an en bloc resection with accurate pathology staging and to avoid missing important histological features (strong recommendation, moderate quality evidence). 2 ESGE recommends endoscopic resection with a curative intent for visible lesions in Barretts esophagus (strong recommendation, moderate quality evidence). ESD has not been shown to be superior to EMR for excision of mucosal cancer, and for that reason EMR should be preferred. ESD may be considered in selected cases, such as lesions larger than 15 mm, poorly lifting tumors, and lesions at risk for submucosal invasion (strong recommendation, moderate quality evidence). 3 ESGE recommends endoscopic resection for the treatment of gastric superficial neoplastic lesions that possess a very low risk of lymph node metastasis (strong recommendation, high quality evidence). EMR is an acceptable option for lesions smaller than 10 - 15 mm with a very low probability of advanced histology (Paris 0-IIa). However, ESGE recommends ESD as treatment of choice for most gastric superficial neoplastic lesions (strong recommendation, moderate quality evidence). 4 ESGE states that the majority of colonic and rectal superficial lesions can be effectively removed in a curative way by standard polypectomy and/or by EMR (strong recommendation, moderate quality evidence). ESD can be considered for removal of colonic and rectal lesions with high suspicion of limited submucosal invasion that is based on two main criteria of depressed morphology and irregular or nongranular surface pattern, particularly if the lesions are larger than 20 mm; or ESD can be considered for colorectal lesions that otherwise cannot be optimally and radically removed by snare-based techniques (strong recommendation, moderate quality evidence).


Hepatology International | 2010

The role of lipopolysaccharide/toll-like receptor 4 signaling in chronic liver diseases.

João-Bruno Soares; Pedro Pimentel-Nunes; Roberto Roncon-Albuquerque; Adelino F. Leite-Moreira

Toll-like receptor 4 (TLR4) is a pattern recognition receptor that functions as lipopolysaccharide (LPS) sensor and whose activation results in the production of several pro-inflammatory, antiviral, and anti-bacterial cytokines. TLR4 is expressed in several cells of healthy liver. Despite the constant confrontation of hepatic TLR4 with gut-derived LPS, the normal liver does not show signs of inflammation due to its low expression of TLR4 and ability to modulate TLR4 signaling. Nevertheless, there is accumulating evidence that altered LPS/TLR4 signaling is a key player in the pathogenesis of many chronic liver diseases (CLD). In this review, we first describe TLR4 structure, ligands, and signaling. Later, we review liver expression of TLR4 and discuss the role of LPS/TLR4 signaling in the pathogenesis of CLD such as alcoholic liver disease, nonalcoholic fatty liver disease, chronic hepatitis C, chronic hepatitis B, primary sclerosing cholangitis, primary biliary cirrhosis, hepatic fibrosis, and hepatocarcinoma.


Gastrointestinal Endoscopy | 2009

A European case series of endoscopic submucosal dissection for gastric superficial lesions

Mário Dinis-Ribeiro; Pedro Pimentel-Nunes; Mariana Afonso; Natalia Costa; Carlos Lopes; Luís Moreira-Dias

BACKGROUND EMR is an accepted method for resection of superficial lesions in the GI tract. However, because it leads, not unusually, to piecemeal resection, histopathologic interpretation problems and an increased risk of recurrence are noticeable. Endoscopic submucosal dissection (ESD) allows a higher rate of en bloc resection, with low recurrence. Nevertheless, this technique, namely in the upper-GI tract, has rarely been described in Western countries, probably because of the rarity of gastric cancer in most countries. OBJECTIVE To describe the efficacy and safety of ESD for gastric superficial lesions in a European country. DESIGN Consecutive case-series report. SETTING A tertiary specialized center. PATIENTS Nineteen patients with gastric superficial lesions (15-30 mm), with high-grade (n = 15) or low-grade (n = 4) noninvasive epithelial neoplasias, in the antrum (n = 12), incisura angularis (n = 2), body (n = 3), and cardia (n = 2). INTERVENTION ESD with the patient under general anesthesia in the endoscopic room (40-300 minutes) by using an insulated-tip-knife. MAIN OUTCOME MEASUREMENTS Complete (R0) and en bloc resection, and complications. RESULTS ESD was achieved in all cases, with 89% R0 resection and 79% en bloc resection rates observed. Major bleeding was reported in 1 case (5%); there were no cases of perforation. With a median follow-up of 10 months, a single recurrence (5%) was observed. LIMITATIONS A small series at a single center, with a short median follow-up time. CONCLUSION We report the feasibility and effectiveness of gastric ESD in Europe. A further description of a Western series is expected, and guidelines for its dissemination are desirable to define the role of this technique in Western countries.


Digestive and Liver Disease | 2013

Functional polymorphisms of Toll-like receptors 2 and 4 alter the risk for colorectal carcinoma in Europeans

Pedro Pimentel-Nunes; Ana Teixeira; Carina Pereira; Mónica Gomes; Catarina Brandão; Catarina Rodrigues; Nádia Gonçalves; Inês Boal-Carvalho; Roberto Roncon-Albuquerque; Luís Moreira-Dias; Adelino F. Leite-Moreira; Rui Medeiros; Mário Dinis-Ribeiro

BACKGROUND Colon carcinogenesis is associated with increased expression levels of Toll-like receptor 2 and Toll-like receptor 4. AIM To determine in a Caucasian population the role of Toll-like receptor 2 and Toll-like receptor 4 polymorphisms in colorectal cancer development. METHODS Hospital based multicentre case control study involving 193 colorectal cancer patients and 278 healthy individuals. DNA samples were extracted from blood cells and genotyping of TLR2+597T>C, TLR2-4760T>C, TLR4-3745A>G, TLR2Arg753Gln, TLR4Asp299Gly was performed. Functionality of risk polymorphisms was evaluated through production of TNF-α in cell culture and Toll-like receptors levels quantified by real-time RT-PCR. RESULTS TLR2+597CC homozygous had 5-fold decreased risk (odds ratio (OR)=0.21, 95% CI: 0.09-0.50, p<0.001) and TLR4 299Gly homozygous 3-fold increased risk of colorectal cancer (OR=3.30, 95% CI: 1.18-9.28, p=0.015). In stratified analysis, TLR2+597CC genotype protective effect was even higher in overweight individuals (OR=0.17, 95% CI: 0.06-0.53, p<0.001) and in never smokers (OR=0.11, 95% CI: 0.02-0.51, p=0.001). Also, the increased risk effect for TLR4 299Gly homozygous genotype was higher in overweight individuals (OR=8.67, 95% CI: 1.11-87.85, p=0.011). TLR2+597T>C polymorphism conferred 41% less (p=0.03) and TLR4Asp299Gly 65% more TNF-α production (p=0.02) with no differences in Toll-like receptors levels. CONCLUSION Functional Toll-like receptor 2 and Toll-like receptor 4 polymorphisms significantly alter the risk to have colorectal cancer. Obesity and smoking may influence the risk for colorectal cancer in individuals presenting these genetic profiles.


Pathology & Oncology Research | 2011

Increased Expression of Toll-like Receptors (TLR) 2, 4 and 5 in Gastric Dysplasia

Pedro Pimentel-Nunes; Luís Pedro Afonso; Paula Lopes; Roberto Roncon-Albuquerque; Nádia Gonçalves; Rui Henrique; Luís Moreira-Dias; Adelino F. Leite-Moreira; Mário Dinis-Ribeiro

TLRs are important innate immunity receptors. Even though TLR2, 4 and 5 appear to be important for Helicobacter pylori (HP) recognition, their role in the evolution of gastritis to more advanced lesions is still unknown. To compare the expression of TLR2, 4 and 5 in normal gastric mucosa, HP+ gastritis, intestinal metaplasia, dysplasia and adenocarcinoma. Immunohistochemistry for TLR2, 4 and 5 was performed with anti-TLR2-TLR4-TLR5 antibodies in 117 histological samples of normal gastric mucosa (n = 22), HP+ gastritis (n = 20), intestinal metaplasia (n = 33), dysplasia (mucosectomy specimens, n = 20) and intestinal type adenocarcinoma (surgery specimens,n = 22); quantification of expression was performed independently by two pathologists taking into account the percentage of positive epithelial cells and the degree of expression (zero to three score). A statistically significant trend for progressive increase of TLRs expression from normal mucosa to gastric dysplasia was found (mean expression: normal mucosa 0.1; gastritis 1.0; metaplasia 2.2; dysplasia 2.8, p < 0.01). All dysplasia samples presented more than 90% positive epithelial cells with strong expression (2.8;95%CI2.7–3). There was less TLRs expression in carcinomas (TLR2:1.0; TLR4:2.0 and TLR5:1.2, p < 0.05) when compared with dysplasia, with TLR4 being more expressed than TLR2 and 5 in these lesions (p = 0.03). A score of all markers’ expression of eight leads to a low (4%) false positive rate in patients with precancerous conditions. Progression of gastric lesions associated with gastric carcinogenesis is associated with increased TLRs expression. Gastric dysplasia presents a high level of TLRs expression, suggesting that these receptors may play a role in adenocarcinoma development.


Helicobacter | 2013

Helicobacter pylori Induces Increased Expression of Toll‐Like Receptors and Decreased Toll‐Interacting Protein in Gastric Mucosa that Persists Throughout Gastric Carcinogenesis

Pedro Pimentel-Nunes; Nádia Gonçalves; Inês Boal-Carvalho; Luís Pedro Afonso; Paula Lopes; Roberto Roncon-Albuquerque; Rui Henrique; Luís Moreira-Dias; Adelino F. Leite-Moreira; Mário Dinis-Ribeiro

Toll‐like receptors (TLR) are essential for Helicobacter pylori (HP) recognition. Their role in the progression of gastric lesions leading to cancer is not established.


Endoscopy | 2014

Long-term follow-up after endoscopic resection of gastric superficial neoplastic lesions in Portugal

Pedro Pimentel-Nunes; Francisco Mourão; Nuno Veloso; Luís Pedro Afonso; Manuel Jácome; Luís Moreira-Dias; Mário Dinis-Ribeiro

BACKGROUND AND STUDY AIMS Although endoscopic resection for the treatment of gastric superficial neoplastic lesions is an established first-line treatment in Eastern countries, its role has yet to be considered in Western guidelines, mostly due to a lack of long-term studies. The aim of this study was to describe long-term outcomes for endoscopic mucosal resection (EMR) and endoscopic submucosal dissection (ESD) in the treatment of gastric neoplasias in Portugal. PATIENTS AND METHODS This was a single-center, retrospective, cohort study between March 2003 and April 2013. A total of 162 consecutive patients with 195 gastric superficial neoplasias underwent EMR (n = 54) or ESD (n = 141) and were followed up for a median of 3.2 years. RESULTS Resection was feasible in 97 %, with en bloc and R0 resection rates of 85 % (94 % ESD vs. 61 % EMR; P = 0.001) and 81 % (91 % ESD vs. 54 % EMR; P < 0.001), respectively. The recurrence rate was 7 %, and recurrence was associated with Rx/R1 resection irrespective of resection technique (OR 5.8; 95 % confidence interval 3.9 - 8.8). The long-term curative resection rate was 86 % after one procedure and 91 % after two procedures. Adverse events were observed in 13 % of cases: 8 % bleeding and 2 % of perforations (EMR = ESD). Surgery was performed in 7 %: 6 % after noncurative endoscopic resection and 1 % due to complications. Metachronous lesion detection rate was 1 % - 1.5 % per patient year. Cancer-specific survival rate was 100 % at follow-up. CONCLUSIONS For the first time in a Western country, results are reported to be similar to those in Eastern countries. Endoscopic resection, particularly ESD, is a highly effective treatment for gastric superficial lesions, without compromising cancer survival. Endoscopic resection should also be considered as first-line treatment for gastric neoplasias in Western countries.


Endoscopy | 2010

Endoscopic submucosal dissection for gastric lesions: results of an European inquiry.

F. Ribeiro-Mourão; Pedro Pimentel-Nunes; Mário Dinis-Ribeiro

BACKGROUND AND STUDY AIMS In Japanese centers, endoscopic submucosal dissection (ESD) is commonly used for the resection of early gastric lesions. However, in Europe, only a few reports have been published. The aim of the current study was to survey the current use of ESD by European endoscopists. METHODS Between April and May 2009, European endoscopists (n = 490) who had articles published in the journals Endoscopy and/or Gastrointestinal Endoscopy during 2007 and 2008 were asked to complete an online questionnaire. RESULTS A total of 58 endoscopists completed the questionnaire (12 %). Only 20 centers performed ESD, which was mostly performed by a single endoscopist in each center. Each endoscopist had treated a mean of four cases during the previous year (mean total experience 11 ESDs) bringing a total of 510 ESDs across all European centers that responded (197 during the past year). Lesions were located in the antrum in 35 % of cases; 39 % were Paris classification IIa, 22 % IIa + b, and 18 % IIa + c. Overall, the average of mean lesion diameter was 15.7 mm (range 1 - 70.0 mm). Most cases were non-invasive high-grade intraepithelial neoplasia (44 %) or adenocarcinoma (36 %). An insulated-tipped knife (1 or 2) was used in 70 % of procedures and an average of the mean duration of procedures was 108 minutes. In all, 78 % of lesions were removed en bloc with an R0 rate of 77 %. Endoscopists experienced major complications (perforation or major bleeding) in 13 % of cases. CONCLUSION ESD in Europe seems to be performed at a few centers, with most endoscopists performing a low number of procedures, achieving a high rate of efficacy and a moderate rate of major complications. However, as a potential selection bias may have occurred, multicenter registries should be conducted to help address the problem of dissemination of this technique.


Innate Immunity | 2012

Increased hepatic expression of TLR2 and TLR4 in the hepatic inflammation-fibrosis-carcinoma sequence:

João-Bruno Soares; Pedro Pimentel-Nunes; Luís Pedro Afonso; Carla Rolanda; Paula Lopes; Roberto Roncon-Albuquerque; Nádia Gonçalves; Inês Boal-Carvalho; Fernando Pardal; Susana Lopes; Guilherme Macedo; Lúcio Lara-Santos; Rui Henrique; Luís Moreira-Dias; Raquel Gonçalves; Mário Dinis-Ribeiro; Adelino F. Leite-Moreira

We evaluated expression of TLR2, TLR4 and proinflammatory genes [NF-κB, TNF-α, cyclooxygenase-2 (COX-2)] in liver samples of patients in different stages of liver disease. Fifteen patients with unexplained transaminases elevation (reference group), 22 with viral chronic hepatitis (hepatitis group), 14 with virus-induced severe fibrosis/cirrhosis (cirrhosis group) and 10 with hepatocarcinoma (hepatocarcinoma group) were consecutively included in the study. Quantification of TLR2, TLR4, NF-κB, TNF-α and COX-2 mRNA was done by real-time RT-PCR and TLR2 and TLR4 protein expression was evaluated by immunohistochemistry. Compared with reference, TLR2 and TLR4 mRNA was increased in hepatitis (TLR2: 2.66 ± 0.69; TLR4: 3.11 ± 0.79; P < 0.05) and cirrhosis (TLR2: 2.14 ± 0.5; TLR4: 1.74 ± 0.27; P < 0.05) and decreased in hepatocarcinoma (TLR2: 0.48 ± 0.15; TLR4: 0.54 ± 0.10; P < 0.05). This associated with increased TNF-α and COX-2 mRNA in hepatitis (TNF-α: 3.24 ± 0.79; COX-2: 2.47 ± 0.36; P < 0.05) and cirrhosis (TNF-α: 1.73 ± 0.28; COX-2: 1.8 ± 0.35, P < 0.05), whereas NF-κB mRNA was increased in hepatitis (2.42 ± 0.31; P < 0.05) and unchanged in cirrhosis (1.34 ± 0.17; P = 0.3). Hepatocarcinoma presented increased COX-2 mRNA (1.63 ± 0.15; P < 0.05) and maintained (at decreased levels) mRNA of NF-κB (0.52 ± 0.12) and TNF-α (0.52 ± 0.12; P < 0.05, all genes). Immunohistochemistry confirmed increased expression of TLR2 and TLR4 in hepatitis and cirrhosis and maintained expression in hepatocarcinoma. Upregulation of TLR2, TLR4 and their proinflammatory mediators is associated with virus-induced hepatic IFC sequence.

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Mário Dinis-Ribeiro

Instituto Português de Oncologia Francisco Gentil

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Diogo Libânio

Instituto Português de Oncologia Francisco Gentil

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Luís Moreira-Dias

Instituto Português de Oncologia Francisco Gentil

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Luís Pedro Afonso

Instituto Português de Oncologia Francisco Gentil

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Jorge Lage

Instituto Português de Oncologia Francisco Gentil

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Rui Medeiros

Fernando Pessoa University

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