We apply Kauffman's automata on small-world networks to study the crossover be- tween the sho... more We apply Kauffman's automata on small-world networks to study the crossover be- tween the short-range and the infinite-range case. We perform accurate calculations on square lattices to obtain both critical exponents and fractal dimensions. Partic- ularly, we find an increase of the damage propagation and a decrease in the fractal dimensions when adding long-range connections.
Background The incidence of surgical site infection in bariatric patients is significant and the ... more Background The incidence of surgical site infection in bariatric patients is significant and the current recommendations for antibiotic prophylaxis are sometimes inadequate. Objective The aim of this study was to analyze the effect of three prophylactic antibiotic regimens on the incidence of surgical site infection. Methods A prospective, cross-sectional study was conducted between January 2009 and January 2013 in which 896 Roux-en-Y gastric bypasses were performed to treat obesity. The study compared three groups of patients according to the perioperative antibiotic prophylaxis administered intravenously and beginning at anesthesia induction: Group I consisting of 194 patients treated with two 3-g doses of ampicillin/sulbactam; Group II with 303 patients treated with a single 1-g dose of ertapenem; and Group III with 399 patients treated with a 2-g dose of cefazolin at anesthesia induction followed by a continuous infusion of cefazolin 1g throughout the surgical procedure. The rate of surgical site infection was analyzed, as well as its association with age, sex, preoperative weight, body mass index and comorbidities. Results The rates of surgical site infection were 4.16% in the group treated prophylactically with ampicillin/sulbactam, 1.98% in the ertapenem group and 1.55% in the continuous cefazolin group. Conclusion The prophylactic use of continuous cefazolin in surgeries for morbid obesity shows very promising results. These findings suggest that some prophylactic regimens need to be reconsidered and even substituted by more effective therapies for the prevention of surgical site infections in bariatric patients.
Background: The sympathetic nervous hyperactivity present in response to surgical stress has been... more Background: The sympathetic nervous hyperactivity present in response to surgical stress has been implicated as an important component of the postoperative paralytic ileus. A randomized and prospective study was conducted, evaluating the effects of the preoperative beta-adrenergic blockade with propranolol in schistosomotic patients during the period of postoperative ileus. Methods: The study compared schistosomotic patients submitted, or not, to beta-adrenergic
OBJETIVO: Analisar a experiência do Serviço de Cirurgia Geral HC/UFPE com os tumores do intesti... more OBJETIVO: Analisar a experiência do Serviço de Cirurgia Geral HC/UFPE com os tumores do intestino delgado, na tentativa de colaborar com a definição de metas para o manejo dessas lesões. MÉTODO: Constitui-se este estudo em uma análise retrospectiva de12 pacientes portadores de neoplasias intestinais atendidos no SCG-HC/UFPE, no período de cinco anos (19941999). Sete eram do sexo masculino (58%). A média de idade à admissão foi de 52 anos. A principal queixa referida foi dor abdominal (83%), seguida por sangramento digestivo e perda ponderal (42%). Massa abdominal palpável foi evidenciada em 50% dos casos. Sete (58%) apresentavam lesões malignas. Dentre as neoplasias benignas, quatro eram leiomiomas. Uma paciente, portadora de síndrome de Peutz-Jeghers, apresentou um hamartoma. Dez foram submetidos a tratamento operatório. Em seis, enterectomia com enteroanastomose foi empregada. Três foram operados em caráter de urgência (um por perfuração intestinal, um por enterorragia maciça e...
Schistosomiasis mansoni is a widespread parasitic disease in the Brazilian territory that affects... more Schistosomiasis mansoni is a widespread parasitic disease in the Brazilian territory that affects over 8 million individuals. Hepatosplenic schistosomiasis is a serious clinical presentation of this disease, associated with splenomegaly, liver fibrosis, and portal hypertension, and is responsible for approximately 7% of schistosomotic patients. The surgical treatment of portal hypertension in schistosomotic patients has distinct features when compared with cirrhotic patients, mostly because hepatic function is preserved in schistosomotic liver disease. Therefore, when attempting to reduce the portal pressure, the surgeon must be aware that the surgery might interfere with hepatic perfusion, and consequently with hepatic function. The aim of this study was to report the results achieved with splenectomy, division of the left gastric vein, devascularization of great gastric curvature, and postoperative endoscopic variceal sclerosis, as a surgical option to esophageal varices in hepato...
Superobese patients who undergo gastric bypass have a greater incidence of complications. The gre... more Superobese patients who undergo gastric bypass have a greater incidence of complications. The greater incidence of comorbidity in this group leads to a higher surgical risk, and a need for special care. By analyzing the risk factors identified in the preoperative period, scoring them, constructing a score and assessing the occurrence of serious complications and death, we will have elements to identify which patients are at greater risk. To determine the accuracy of the Recife Score for predicting serious postoperative complications and death in superobese patients who undergo Roux-en-Y gastric bypass surgery by the conventional method. An ambidirectional study was conducted to validate the diagnostic test on 203 severely obese patients submitted to Roux-en-Y gastric bypass at the Hospital das Clínicas of the Federal University of Pernambuco, Recife, PE, Brazil, from September 1997 to May 2007. The dependent variables were major postoperative complications and death. The independent...
With the intention of evaluating the effectiveness and the maintenance of the postoperative endos... more With the intention of evaluating the effectiveness and the maintenance of the postoperative endoscopic sclerosis as routine, in association to splenectomy with left gastric vein ligature and devascularization of the great curvature of the stomach, the present study was accomplished. Between 1992 and 1998, 131 patient were operated in the General Division of the "Hospital das Clínicas" (Federal University of Pernambuco, Recife, PE, Brazil). The medium follow-up was 30 months. All patients were requested to come back to the clinic for accomplishment of clinical and laboratory control. Of the 111 patients that came back to the clinic, 80 patients had a digestive endoscopy done. Of these 80 patients, 36 followed the recommendation and underwent to a postoperative endoscopic sclerosis program (group 1), while 44 did not accomplish postoperative endoscopic sclerosis (group 2). Regarding the eradication of the esophagus varices, the authors found a statistical difference between ...
Obesity is an important cause of cardiovascular disease, especially coronary artery disease. Seve... more Obesity is an important cause of cardiovascular disease, especially coronary artery disease. Severely obese patients are particularly prone to this risk. The coronary artery calcium (CAC) score is a strong predictor of coronary heart disease and provides incremental information beyond traditional risk factors. We sought to determine the prevalence of abnormally high CAC scores in the preoperative setting among patients undergoing bariatric surgery and to establish risk predictors for higher scores. We performed an observational study of 202 patients free of known coronary artery disease who were referred for bariatric surgery. In each patient, the presence of CAC was detected with computed tomography, and coronary risk variables were either measured or determined via questionnaire. CAC was found in 14.4% of the overall population (26% of male and 10.5% of female patients). Participants with altered CAC scores were older (mean age, 46.8 years). The variables positively associated wit...
To evaluate the degree of influence that periportal fibrosis has on clinical development and the ... more To evaluate the degree of influence that periportal fibrosis has on clinical development and the long term results of surgical treatment on patients with hepatic-splenic schistosomiasis with previous gastrointestinal hemorrhages. During the period of 1992-1998, 111 patients underwent surgical treatment for the treatment of hepatic-splenic schistosomiasis with previous gastrointestinal hemorrhages. The degree of fibrosis was classified as: degree I - the portal spaces show a rich increase of young connective cells, a slight collagen production and a varying presence of inflammatory infiltrate. The periportal blade unchangeable (29/111); degree II - there is an expansion of the connective tissue with the emission of radial collagen septa, producing a star shaped aspect (38/111); degree III - the connective septa form bridges with other portal spaces or with the vein, with evident angiomatoid neo-formation (44/111). The patients with periportal fibrosis degree I present recurrent hemor...
Physical Review E - Statistical, Nonlinear, and Soft Matter Physics, 2006
This study reports deuterium nuclear-magnetic-resonance (NMR) spectra collected at 61.4MHz in the... more This study reports deuterium nuclear-magnetic-resonance (NMR) spectra collected at 61.4MHz in the chiral smectic- C phase of liquid crystal 4{'}(octyloxy)-d{17} biphenyl-4- yl2 -chloro-3-methylpentanoate (BP8Cl). By using a goniometer probe, the oriented sample was rotated to collect spectra at different rotation (theta) angles. These spectra were simulated to gain information on solitonlike distortions in the helical superstructure. The Landau theory was adopted to study the distortion of the helix by the NMR magnetic field. Deuterium two-dimensional exchange experiments were also used on the aligned sample at theta=15 degrees to obtain dynamic parameters through the spectral simulation. The interlayer diffusion constants in the SmC{*} phase were estimated from a proton T(1) dispersion study. The pitch length of BP8Cl is estimated to be circa 2-3 microns at one temperature.
Arquivos brasileiros de cirurgia digestiva : ABCD = Brazilian archives of digestive surgery, 2014
Despite of benefits of bariatric surgery for obesity treatment, the procedure may be related to s... more Despite of benefits of bariatric surgery for obesity treatment, the procedure may be related to some complications. Analyze studies to address the relation between nephrolithiasis and bariatric surgery. Ten papers about this theme were selected from 2005-2013 in Pubmed, describing the relation of nephrolithiasis or their risk factors with several types of bariatric surgery. Retrospective studies with minimal follow-up of three years demonstrated 7,65% in surgery patients and 4,63% non-surgery with nephrolithiasis (p<0,05). Prospective studies (8 of 10) revealed large percentage of calculi appearing and significant increase in oxaluria. There is correlation between obesity surgery and nephrolithiasis.
We apply Kauffman's automata on small-world networks to study the crossover be- tween the sho... more We apply Kauffman's automata on small-world networks to study the crossover be- tween the short-range and the infinite-range case. We perform accurate calculations on square lattices to obtain both critical exponents and fractal dimensions. Partic- ularly, we find an increase of the damage propagation and a decrease in the fractal dimensions when adding long-range connections.
Background The incidence of surgical site infection in bariatric patients is significant and the ... more Background The incidence of surgical site infection in bariatric patients is significant and the current recommendations for antibiotic prophylaxis are sometimes inadequate. Objective The aim of this study was to analyze the effect of three prophylactic antibiotic regimens on the incidence of surgical site infection. Methods A prospective, cross-sectional study was conducted between January 2009 and January 2013 in which 896 Roux-en-Y gastric bypasses were performed to treat obesity. The study compared three groups of patients according to the perioperative antibiotic prophylaxis administered intravenously and beginning at anesthesia induction: Group I consisting of 194 patients treated with two 3-g doses of ampicillin/sulbactam; Group II with 303 patients treated with a single 1-g dose of ertapenem; and Group III with 399 patients treated with a 2-g dose of cefazolin at anesthesia induction followed by a continuous infusion of cefazolin 1g throughout the surgical procedure. The rate of surgical site infection was analyzed, as well as its association with age, sex, preoperative weight, body mass index and comorbidities. Results The rates of surgical site infection were 4.16% in the group treated prophylactically with ampicillin/sulbactam, 1.98% in the ertapenem group and 1.55% in the continuous cefazolin group. Conclusion The prophylactic use of continuous cefazolin in surgeries for morbid obesity shows very promising results. These findings suggest that some prophylactic regimens need to be reconsidered and even substituted by more effective therapies for the prevention of surgical site infections in bariatric patients.
Background: The sympathetic nervous hyperactivity present in response to surgical stress has been... more Background: The sympathetic nervous hyperactivity present in response to surgical stress has been implicated as an important component of the postoperative paralytic ileus. A randomized and prospective study was conducted, evaluating the effects of the preoperative beta-adrenergic blockade with propranolol in schistosomotic patients during the period of postoperative ileus. Methods: The study compared schistosomotic patients submitted, or not, to beta-adrenergic
OBJETIVO: Analisar a experiência do Serviço de Cirurgia Geral HC/UFPE com os tumores do intesti... more OBJETIVO: Analisar a experiência do Serviço de Cirurgia Geral HC/UFPE com os tumores do intestino delgado, na tentativa de colaborar com a definição de metas para o manejo dessas lesões. MÉTODO: Constitui-se este estudo em uma análise retrospectiva de12 pacientes portadores de neoplasias intestinais atendidos no SCG-HC/UFPE, no período de cinco anos (19941999). Sete eram do sexo masculino (58%). A média de idade à admissão foi de 52 anos. A principal queixa referida foi dor abdominal (83%), seguida por sangramento digestivo e perda ponderal (42%). Massa abdominal palpável foi evidenciada em 50% dos casos. Sete (58%) apresentavam lesões malignas. Dentre as neoplasias benignas, quatro eram leiomiomas. Uma paciente, portadora de síndrome de Peutz-Jeghers, apresentou um hamartoma. Dez foram submetidos a tratamento operatório. Em seis, enterectomia com enteroanastomose foi empregada. Três foram operados em caráter de urgência (um por perfuração intestinal, um por enterorragia maciça e...
Schistosomiasis mansoni is a widespread parasitic disease in the Brazilian territory that affects... more Schistosomiasis mansoni is a widespread parasitic disease in the Brazilian territory that affects over 8 million individuals. Hepatosplenic schistosomiasis is a serious clinical presentation of this disease, associated with splenomegaly, liver fibrosis, and portal hypertension, and is responsible for approximately 7% of schistosomotic patients. The surgical treatment of portal hypertension in schistosomotic patients has distinct features when compared with cirrhotic patients, mostly because hepatic function is preserved in schistosomotic liver disease. Therefore, when attempting to reduce the portal pressure, the surgeon must be aware that the surgery might interfere with hepatic perfusion, and consequently with hepatic function. The aim of this study was to report the results achieved with splenectomy, division of the left gastric vein, devascularization of great gastric curvature, and postoperative endoscopic variceal sclerosis, as a surgical option to esophageal varices in hepato...
Superobese patients who undergo gastric bypass have a greater incidence of complications. The gre... more Superobese patients who undergo gastric bypass have a greater incidence of complications. The greater incidence of comorbidity in this group leads to a higher surgical risk, and a need for special care. By analyzing the risk factors identified in the preoperative period, scoring them, constructing a score and assessing the occurrence of serious complications and death, we will have elements to identify which patients are at greater risk. To determine the accuracy of the Recife Score for predicting serious postoperative complications and death in superobese patients who undergo Roux-en-Y gastric bypass surgery by the conventional method. An ambidirectional study was conducted to validate the diagnostic test on 203 severely obese patients submitted to Roux-en-Y gastric bypass at the Hospital das Clínicas of the Federal University of Pernambuco, Recife, PE, Brazil, from September 1997 to May 2007. The dependent variables were major postoperative complications and death. The independent...
With the intention of evaluating the effectiveness and the maintenance of the postoperative endos... more With the intention of evaluating the effectiveness and the maintenance of the postoperative endoscopic sclerosis as routine, in association to splenectomy with left gastric vein ligature and devascularization of the great curvature of the stomach, the present study was accomplished. Between 1992 and 1998, 131 patient were operated in the General Division of the "Hospital das Clínicas" (Federal University of Pernambuco, Recife, PE, Brazil). The medium follow-up was 30 months. All patients were requested to come back to the clinic for accomplishment of clinical and laboratory control. Of the 111 patients that came back to the clinic, 80 patients had a digestive endoscopy done. Of these 80 patients, 36 followed the recommendation and underwent to a postoperative endoscopic sclerosis program (group 1), while 44 did not accomplish postoperative endoscopic sclerosis (group 2). Regarding the eradication of the esophagus varices, the authors found a statistical difference between ...
Obesity is an important cause of cardiovascular disease, especially coronary artery disease. Seve... more Obesity is an important cause of cardiovascular disease, especially coronary artery disease. Severely obese patients are particularly prone to this risk. The coronary artery calcium (CAC) score is a strong predictor of coronary heart disease and provides incremental information beyond traditional risk factors. We sought to determine the prevalence of abnormally high CAC scores in the preoperative setting among patients undergoing bariatric surgery and to establish risk predictors for higher scores. We performed an observational study of 202 patients free of known coronary artery disease who were referred for bariatric surgery. In each patient, the presence of CAC was detected with computed tomography, and coronary risk variables were either measured or determined via questionnaire. CAC was found in 14.4% of the overall population (26% of male and 10.5% of female patients). Participants with altered CAC scores were older (mean age, 46.8 years). The variables positively associated wit...
To evaluate the degree of influence that periportal fibrosis has on clinical development and the ... more To evaluate the degree of influence that periportal fibrosis has on clinical development and the long term results of surgical treatment on patients with hepatic-splenic schistosomiasis with previous gastrointestinal hemorrhages. During the period of 1992-1998, 111 patients underwent surgical treatment for the treatment of hepatic-splenic schistosomiasis with previous gastrointestinal hemorrhages. The degree of fibrosis was classified as: degree I - the portal spaces show a rich increase of young connective cells, a slight collagen production and a varying presence of inflammatory infiltrate. The periportal blade unchangeable (29/111); degree II - there is an expansion of the connective tissue with the emission of radial collagen septa, producing a star shaped aspect (38/111); degree III - the connective septa form bridges with other portal spaces or with the vein, with evident angiomatoid neo-formation (44/111). The patients with periportal fibrosis degree I present recurrent hemor...
Physical Review E - Statistical, Nonlinear, and Soft Matter Physics, 2006
This study reports deuterium nuclear-magnetic-resonance (NMR) spectra collected at 61.4MHz in the... more This study reports deuterium nuclear-magnetic-resonance (NMR) spectra collected at 61.4MHz in the chiral smectic- C phase of liquid crystal 4{&amp;amp;amp;amp;amp;amp;amp;amp;#39;}(octyloxy)-d{17} biphenyl-4- yl2 -chloro-3-methylpentanoate (BP8Cl). By using a goniometer probe, the oriented sample was rotated to collect spectra at different rotation (theta) angles. These spectra were simulated to gain information on solitonlike distortions in the helical superstructure. The Landau theory was adopted to study the distortion of the helix by the NMR magnetic field. Deuterium two-dimensional exchange experiments were also used on the aligned sample at theta=15 degrees to obtain dynamic parameters through the spectral simulation. The interlayer diffusion constants in the SmC{*} phase were estimated from a proton T(1) dispersion study. The pitch length of BP8Cl is estimated to be circa 2-3 microns at one temperature.
Arquivos brasileiros de cirurgia digestiva : ABCD = Brazilian archives of digestive surgery, 2014
Despite of benefits of bariatric surgery for obesity treatment, the procedure may be related to s... more Despite of benefits of bariatric surgery for obesity treatment, the procedure may be related to some complications. Analyze studies to address the relation between nephrolithiasis and bariatric surgery. Ten papers about this theme were selected from 2005-2013 in Pubmed, describing the relation of nephrolithiasis or their risk factors with several types of bariatric surgery. Retrospective studies with minimal follow-up of three years demonstrated 7,65% in surgery patients and 4,63% non-surgery with nephrolithiasis (p<0,05). Prospective studies (8 of 10) revealed large percentage of calculi appearing and significant increase in oxaluria. There is correlation between obesity surgery and nephrolithiasis.
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