George Pinedo
Pontifical Catholic University of Chile
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Featured researches published by George Pinedo.
Immunobiology | 2012
Enzo Candia; David Díaz-Jiménez; Patricia Langjahr; Lucía E. Núñez; Marjorie De la Fuente; Nancy Farfán; Francisco López-Köstner; Mario Abedrapo; Manuel Alvarez-Lobos; George Pinedo; Caroll J Beltrán; Carlos González; María Julieta González; Rodrigo Quera; Marcela A. Hermoso
Toll-like receptor 2 (TLR2) is a type I pattern recognition receptor that has been shown to participate in intestinal homeostasis. Its increased expression in the lamina propria has been associated with the pathogenesis in inflammatory bowel disease (IBD), such as ulcerative colitis (UC) and Crohns disease (CD). Recently, soluble TLR2 (sTLR2) variants have been shown to counteract inflammatory responses driven by the cognate receptor. Despite the evident roles of TLR2 in intestinal immunity, no study has elucidated the production and cellular source of sTLR2 in IBD. Furthermore, an increase in the population of activated macrophages expressing TLR2 that infiltrates the intestine in IBD has been reported. We aimed first to assess the production of the sTLR2 by UC and CD organ culture biopsies and lamina propria mononuclear cells (LPMCs) as well as the levels of sTLR2 in serum, and then characterize the cell population from lamina propria producing the soluble protein. Mucosa explants, LPMCs and serum were obtained from UC, CD patients and control subjects. The level of sTLR2 was higher in conditioned media from organ culture biopsies and LPMCs from UC patients in comparison to CD and controls. Moreover, an inverse correlation between the content of intestinal and serum sTLR2 levels was observed in UC patients. Additionally, when characterizing the cellular source of the increased sTLR2 by LPMCs from UC patients, an increase in TLR2(+)/CD33(+) cell population was found. Also, these cells expressed CX3CR1, which was related to the increased levels of intestinal FKN in UC patients, suggesting that a higher proportion of TLR2(+) mononuclear cells infiltrate the lamina propria. The increased production of sTLR2 suggests that a differential regulating factor of the innate immune system is present in the intestinal mucosa of UC patients.
Revista Medica De Chile | 2013
Gonzalo Urrejola; Claudia Bambs; Manuel Espinoza; José Gellona V; Álvaro Zúñiga; María Elena Molina; Felipe Bellolio; Rodrigo Miguieles; James M Campbell; George Pinedo
The neutrophil/lymphocyte ratio is an effective marker of inflammation and can have prognostic value in surgical patients. Aim: To evaluate the effect of an increased neutrophil/lymphocyte ratio (NLR) on perioperative complications ana overall ana disease-free survival in patients undergoing elective resection for stage II colon cancer. Material and Methods: Data was obtained from clinical charts, preoperative blood results and hospital records of all patients undergoing an elective curative resection for colon cancer, between 2000 and 2007. Preoperative NLR was calculated. Follow-up was obtained from a prospectively maintained colorectal cancer database, clinical records and questionnaires. Uni and multivariable analysis were performed to identify associations, and survival analysis was performed using Kaplan-Meier curves. Results: One hundred twenty two patients with a mean age of 69years (52% males), were evaluated. Median follow-up was 73 months, and overall survival for 1 and 5 years was 95% and 68%, respectively. On a multivariable analysis after adjusting for age, sex, tumor depth invasion, use of adjuvant therapies and American Society of Anesthesiology preoperative risk score, an NLR > 5 was associated with an increased perioperative complication rate (odds ratio: 3,06, p = 0,033). Kaplan-Meier survival analysis showed a worse overall and disease-free survival for patients with NLR greater than five. Conclusions: A preoperative NLR of five or more is associated with greater perioperative morbidity and worse oncological outcomes in patients undergoing resection for elective stage II colon cancerBACKGROUND The neutrophil/lymphocyte ratio is an effective marker of inflammation ana can have prognostic value in surgical patients. AIM To evaluate the effect of an increased neutrophil/lymphocyte ratio (NLR) on perioperative complications ana overall ana disease-free survival in patients undergoing elective resection for stage II colon cancer. MATERIAL AND METHODS Data was obtained from clinical charts, preoperative blood results and hospital records of all patients undergoing an elective curative resection for colon cancer, between 2000 and 2007. Preoperative NLR was calculated. Follow-up was obtained from a prospectively maintained colorectal cancer database, clinical records and questionnaires. Uni and multivariable analysis were performed to identify associations, and survival analysis was performed using Kaplan-Meier curves. RESULTS One hundred twenty two patients with a mean age of 69 years (52% males), were evaluated. Median follow-up was 73 months, and overall survival for 1 and 5 years was 95% and 68%, respectively. On a multivariable analysis after adjusting for age, sex, tumor depth invasion, use of adjuvant therapies and American Society of Anesthesiology preoperative risk score, an NLR > 5 was associated with an increased perioperative complication rate (odds ratio: 3.06, p = 0.033). Kaplan-Meier survival analysis showed a worse overall and disease-free survival for patients with NLR greater than five. CONCLUSIONS A preoperative NLR of five or more is associated with greater perioperative morbidity and worse oncological outcomes in patients undergoing resection for elective stage II colon cancer.
Anesthesia & Analgesia | 2009
Mario Concha; Verónica F. Mertz; Luis I. Cortínez; Katya A. González; Jean M. Butte; Francisco López; George Pinedo; Álvaro Zúñiga
BACKGROUND: Recent studies have emphasized the importance of perioperative fluid restriction. However, fluid restriction regimens may increase the likelihood of insufficient perioperative fluid administration or may result in excess intravascular crystalloid replacement. We postulate that the use of transesophageal echocardiography may reduce the amount of crystalloid administered during open and laparoscopic colorectal surgery. METHODS: Fifteen ASA I and II patients scheduled for open colorectal surgery, and 15 patients scheduled for laparoscopic surgery were studied. Lactated Ringers solution was infused during the procedures. Left ventricular end diastolic volume index (LVEDVI) and cardiac index were assessed throughout surgery and used to guide the rate of lactated Ringers solution administration. Statistical analysis was performed with Students t-test for unpaired samples. RESULTS: The rate of crystalloid administration required to maintain baseline LVEDVI and cardiac index was 5.9 ± 2 mL · kg−1 · h−1 for open surgery and 3.4 ± 0.8 mL · kg−1 · h−1 for laparoscopic surgery (P < 0.01). This slower rate for laparoscopic surgery was offset by the longer surgical duration. CONCLUSION: The rate of crystalloid solution to maintain baseline LVEDVI and cardiac index was greater in open surgery than laparoscopic surgery, and lower than commonly recommended for colorectal surgery.
Colorectal Disease | 2009
George Pinedo; E. García; Alejandro Zárate; F. León; Felipe Bellolio; María Elena Molina; P. Viviani; Álvaro Zúñiga
Background Histopathological studies have shown the presence of oestrogenic receptors in the anal sphincter, which presumes a role in muscular trophism for circulating oestrogens. This could explain the increase in faecal incontinence (FI) in postmenopausal women.
Colorectal Disease | 2012
George Pinedo; Alejandro Zárate; G. Inostroza; X. Meneses; E. Falloux; O. Molina; María Elena Molina; Felipe Bellolio; Álvaro Zúñiga
Aim In a randomized double‐blind study the therapeutic effect of a novel zinc–aluminium ointment was compared with placebo in patients with faecal incontinence.
Revista Chilena De Cirugia | 2006
Francisco López Kostner; Alejandro Zárate; Francisca León; Felipe Bellolio; George Pinedo; María Elena Molina; Gonzalo Soto
Resumen es: Han pasado 15 anos desde la primera publicacion de una cirugia laparoscopica por cancer colorrectal (CLCC) y finalmente parece ser que la evidencia la ap...
Cirugia Espanola | 2010
Gino Caselli; Claudia Bambs; George Pinedo; María Elena Molina; Álvaro Zúñiga; Felipe Bellolio
INTRODUCTION Intestinal passage reconstruction after Hartmanns (PRH) operation is associated with a high morbidity and mortality of about 1%. Despite the increasing use of laparoscopy as an alternative in PRH, there is a lack of patient series at international level. PATIENTS AND METHODS The prospective series of patients subjected to (PRH) by laparoscopy was analysed using the demographic parameters, ASA classification, reason for primary surgery, time between initial surgery and reconstruction, operation time, conversion to open surgery, bowel rest recovery time, complications, hospital stay and follow up. RESULTS A total of 30 patients with a mean age of 61.5 ± 13 years were operated on using laparoscopy. The ASA classification was 1.8 ± 0.3 the BMI was 26.1 ± 2 Kg/m(2). A total of 63% were admitted due to complicated Hinchley III or IV acute diverticulitis. The interval between initial surgery and the passage reconstruction was 7.1 ± 2 months. Conversion to open surgery was necessary in three cases. The mean intestinal passage recovery was 2.1 ± 1 days and the hospital stay was 5.6 ± 1 days. The long-term complications were one mechanic ileum due to bridles and one case of anastomotic stenosis. CONCLUSIONS The post-Hartmann laparoscopic passage reconstruction is associated with a short intestinal motility recovery time, as well as a less prolonged hospital stay compared to an open surgery series. Randomised studies are needed to determine whether laparoscopic reconstruction is superior to the conventional technique.
Revista Medica De Chile | 2009
Enrique Norero; Nicolás Jarufe; Jean Michel Butte; Blanca Norero; Ignacio Duarte; Javiera Torres; George Pinedo; Francisco López; Juan Francisco Guerra; Luis Ibáñez; Álvaro Zúñiga; Sergio Guzmán; Jorge Martínez
Background: Surgical resection is the only treatment associated with long-term cure in patients with liver metastasis from colorectal cancer, achieving a 30% to 40% five years survival. Aim: To evaluate the results of liver resection for metastatic colorectal cancer in our centre. Patients and methods: Retrospective study. Epidemiological, perioperative and follow up data of patients undergoing liver resection for metastatic colorectal cancer between January 1990 and July 2007 were assessed. We compared the results between two periods; period 1 (1990-1997) and period 2 (1998-2007). Results: Sixty six patients aged 61±12 years (46 males) underwent 75 resections. An anatomical excision was performed in 54 (72%) cases, a right hepatectomy in 18, an extended right hepatectomy in 11, a left hepatectomy in 1, and a segmentectomy in 24. In 24 (32%) patients the liver resection was simultaneous with the colorectal cancer resection. Operative time was 221±86 min. Hospital stay was 11±5 days. Postoperative morbidity was 35% and surgical mortality was 0%. Resection margin was free of tumor in 53 (80%) patients. Five years overall and hepatic disease-free survival was 38% and 23%, respectively. In period 2, more anatomical resections than in period 1 were performed (77% and 55%, respectively, p =0.04), without an increase in complications (35% and 34%, respectively; p =ns), but with a better five years survival (45% and 21%, respectively, p =0.04). Conclusions: Five years survival for excision of liver metastatic colorectal cancer in our center is similar to that reported abroad. During the second period there has been a trend toward more extensive resections which was associated with a better survival, without an increase in complications or mortality (Rev Med Chile 2009; 137: 487-96). (Key words: Colorectal neoplasms; Neoplasm metastasis; Survival)
Revista Medica De Chile | 2008
Francisco López-Köstner; Alejandro Zárate; George Pinedo; María Elena Molina; Udo Kronberg; Javiera Pardo
BACKGROUND The laparoscopic approach is an alternative for the elective treatment of diverticular colon disease (DCD). AIM To analyze the results of patients electively operated for DCD using a laparoscopic technique. MATERIAL AND METHODS Data of patients with DCD operated using laparoscopy at the Catholic University of Chile Clinical Hospital were prospectively recorded from January 1999 to August 2006. Indications for surgery were repetitive crises of acute diverticulitis, the persistence of the symptoms or anatomic deformity after the first crisis and complicated diverticulitis (Hinchey 1-2) that responded to the medical treatment. The laparoscopic technique used five ports and the surgical specimen was extracted through a suprapubic approach. RESULTS One hundred and six patients aged 32 to 82 years (49% females) were operated in the study period. Fifty five percent had a previous abdominal surgery. The mean operative time was 213 minutes (range: 135-360). Four patients were converted to open surgery (3.7%). One or more early post-operative complications were observed in five patients (4.7%). The mean time for passing gases and reinitiate liquid diet was 1.7 and 2.4 days respectively. The median post operative stay after surgery was 4 days. There was no operative mortality. Mean follow-up time was 27 months and only one patient (0.9%) had a new episode of acute diverticular disease, with a satisfactory response to medical treatment. No patient has developed bowel obstruction. CONCLUSIONS The laparoscopic approach is a safe alternative in the elective surgical treatment of DCD.
Surgical Endoscopy and Other Interventional Techniques | 2009
George Pinedo; Alejandro Zárate; Eduardo Miñambres García; María Elena Molina; Francisco López; Álvaro Zúñiga