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PURPOSE: To assess the clinical performance of restorations with ground and unground enamel for diastema closure. METHODS AND MATERIALS: Twenty-four patients attended and received two to ten composite build-ups for diastema closure. The restorations were performed separately by grinding and not grinding the enamel on the proximal surfaces on symmetric teeth. A nanofill direct composite (Filtek Ultimate Universal Restorative System, 3M ESPE, St Paul, MN, USA) was used with a three-step etch-and-rinse adhesive (Scotchbond Multi-Purpose, 3M ESPE) for restorations. Restorations were evaluated according to the modified United States Public Health Service (USPHS) criteria at baseline and 1-, 2-, 3-, 4-, and 5-year recalls. RESULTS: The cumulative success rate of direct composite build-up with ground and unground enamel was 100% and 88.7%, respectively. Six restorations with unground enamel failed due to fracture. No significant difference was found between the restorations with ground enamel and unground enamel with regard to the evaluation criteria. CONCLUSION: The 5-year success rates of restorations with ground and unground enamel were excellent. The success rate of restorations with ground enamel was higher than that of restorations with unground enamel. Fracture was the reason for failure in the restorations with unground enamel.
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Cementos Dentales , Diastema , Humanos , Cementos Dentales/uso terapéutico , Cementos Dentales/química , Recubrimientos Dentinarios/química , Resinas Compuestas/uso terapéutico , Resinas Compuestas/química , Estudios de Seguimiento , Cementos de Resina/uso terapéutico , Cementos de Resina/química , Esmalte Dental , Restauración Dental Permanente/métodosRESUMEN
BACKGROUND AND AIM: Chronic pancreatitis (CP)-related pain is a considerable problem in gastroenterology practice that frequently requires several endoscopic interventions. We aimed to investigate the efficacy of pancreatic duct stenting performed on demand, instead of at defined intervals, for the management of the CP-related pain. METHODS: This study is a retrospective evaluation of thirteen years of data. Sixty-seven patients with CP who suffered from intractable pain were enrolled in the study. Pancreatic stenting was performed mainly with single stents according to the diameter of the pancreatic duct and width of the stricture or, less frequently, with multiple stents aiming to achieve stricture resolution. The subsequent endoscopic session was scheduled based on the patient's symptoms. RESULTS: Overall, 65 of 67 patients underwent successful pancreatic cannulation (technical success rate 97%). Fifty-seven patients with a pancreatic stenting history were still undergoing follow-up. Of these patients, 26 patients still had pancreatic ductal stents; however, the stents were removed from 31 patients. Only 8 patients (25%) required further endoscopic or surgical intervention because of the re-emergence of pain after a median stent-free period of 17 months (3-127 months). One patient with a biliary stricture and one patient with a pancreatic mass underwent surgery. Pancreatic stents remained for a median length of 14 months (3-84 months). During the follow-up period, 55 of 65 patients became pain-free or had partial pain relief (clinical success rate 84%). CONCLUSIONS: On demand replacement of pancreatic stent is feasible in patients with CP and it might provide a good palliation of CP-related pain.
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Conductos Pancreáticos/cirugía , Pancreatitis Crónica/cirugía , Stents , Enfermedad Crónica , Humanos , Dolor/etiología , Dolor/cirugía , Estudios RetrospectivosRESUMEN
Obesity is a chronic disease that is characterized by increased body fat owing to imbalance between consumed and expended energy. Inflammation generally is accompanied by accumulation of excess lipid in adipose tissue and liver. High mobility group box-1 (HMGB1) participates in the pathogenesis of inflammatory diseases. We investigated the relation of the number of HMGB1 positive cells to body mass index (BMI), liver inflammation and the number of Kupffer cells. We divided 18 female Wistar albino rats into two groups: group 1, untreated control fed normal commercial rat diet and group 2, obese rats fed a special diet containing 40% fat. The plasma concentrations of cholesterol, glucose, superoxide dismutase enzyme (SOD) and catalase activities were measured for all animals. The numbers of hepatocytes, Kupffer cells and HMGB1 positive cells were counted using stereological methods. The mean numbers of Kupffer cells and HMGB1 positive cells were higher for group 2 than for group 1. The concentrations of plasma cholesterol and glucose levels also were higher in group 2. Plasma levels of SOD and catalase were significantly lower in group 2 compared to group 1. The number of HMGB1 cells was related directly to BMI and inflammation. The role of HMGB1 was demonstrated for the liver of the obese group. We demonstrated the relations among HMGB1, BMI, obesity and inflammation.
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Proteína HMGB1/metabolismo , Hepatitis/metabolismo , Inflamación/metabolismo , Hígado/metabolismo , Obesidad/patología , Tejido Adiposo/metabolismo , Tejido Adiposo/patología , Animales , Modelos Animales de Enfermedad , Femenino , Inflamación/patología , Hígado/patología , Obesidad/metabolismo , Ratas WistarRESUMEN
AIM: The aim of this study was to investigate the serum oxidative stress markers, antioxidant enzyme and tumor necrosis factor-α (TNF-α) levels at 24-28 weeks of gestation and to evaluate the predictive value of them on the subsequent treatment protocol in gestational diabetes mellitus (GDM). METHODS: A total of 58 GDM patients (30 treated with only conventional healthy dietary recommendation (CHDR), 28 treated with insulin) and 30 healthy pregnant women at 24-28 weeks of gestation, were enrolled in this prospective case-control study. The oxidative status, antioxidant enzyme and TNF-α levels were evaluated to determine if there is an association with the need of insulin therapy for glycemic control by using multivariable logistic regression analysis. RESULTS: TNF-α (OR=11.976, 95%CI: 2.441-58.754, P=0.002) and total antioxidant status (TAS) (OR=12.769, 95%CI: 2.464-66.182, P=0.002) were found to be predictive for GDM at 24-28 weeks of gestation. Besides, further evaluation considering the treatment modality showed that increased TNF-α (OR=18.615, 95%CI: 2.338-148.240, P=0.006) and lower TAS levels (OR=99.471, 95%CI: 2.865-3 453.061, P=0.011) were independent predictors of the need for insulin treatment in GDM patients. CONCLUSIONS: Increased TNF-α levels and low TAS are significantly associated with the increased risk of insulin requirement for achieving good glycemic control in GDM.
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Antioxidantes/metabolismo , Diabetes Gestacional/sangre , Diabetes Gestacional/tratamiento farmacológico , Insulina/administración & dosificación , Factor de Necrosis Tumoral alfa/sangre , Adulto , Biomarcadores/sangre , Estudios de Casos y Controles , Femenino , Humanos , Embarazo , Estudios ProspectivosRESUMEN
CONTEXT: We aimed to examine the factors affecting adverse gestational outcome in gestational diabetes (GDM) patients, who were grouped as obese and normal- weight, having only-diet, or insulin treatments. SUBJECTS AND METHODS: The study included 373 patients, treated with diet or insulin. These patients were sub-grouped as obese and non-obese, and examined retrospectively. The variables affecting adverse gestational outcome in obese GDM patients having dietary and/ or insulin treatments were detected with multiple regression analysis. RESULTS: The weight gained during pregnancy in the GDM group having insulin treatment was more than the one in only-diet treated GDM group (p=0.004). Pre-pregnancy body mass index, the weight gained during pregnancy, hemoglobin A1C levels in the second and third trimesters, caesarian rates were higher in the insulin-treated obese patients than in the other groups (p<0.001). The odds ratio for fasting blood glucose level in insulin-treated obese GDM group was 1.081 (95% CI =1.004 - 1.163) (p=0.039); and it was 0.982 (95% CI =0.924 - 1.002) (p=0.048) for the weight gained during pregnancy, in only-diet treated obese GDM patients. CONCLUSION: The control of weight gained during pregnancy, and of fasting blood glucose levels in obese patients having GDM, is important to decrease adverse gestational outcome.
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PURPOSE: We aimed to determine the relation of a disintegrin and metalloproteinase with thrombospondin motifs-4 (ADAMTS4), and a disintegrin and metalloproteinase with thrombospondin motifs-9 (ADAMTS9) with cardiovascular disease (CVD) risk, in ovarian dysfunction patients with premature ovarian insufficiency (POI), and idiopathic hypogonadotropic hypogonadism (IHH). METHODS: 43 IHH and 44 POI patients were enrolled to this case-control study. Serum hormonal parameters, lipid profiles, ADAMTS4 and ADAMTS9 levels were measured. Lipid accumulation product (LAP) index, visceral adiposity index (VAI), and homeostasis model assessment of insulin resistance (HOMA-IR) were calculated. The patients with at least two out of the four following criteria were accepted to have increased CVD risk; waist-to-hip ratio (WHR) ≥ 0.8, waist circumference (WC) ≥ 79 cm, triglycerides (TG) ≥ 150 mg/dL, high-density lipoprotein cholesterol (HDL-C) < 50 mg/dL. Serum ADAMTS4 and ADAMTS9 levels were measured by enzyme-linked immunosorbent assay (ELISA). RESULTS: ADAMTS4 and ADAMTS9 levels were significantly higher in the IHH group than the POI group (p = 0.002, and p = 0.013, respectively). IHH group had significantly higher levels of insulin, HOMA-IR index, and LAP index (p = 0.006, p = 0.005, and p = 0.013, respectively). The mean age of patients in the IHH group (23.60 ± 5.64 years) was significantly lower than the POI group (31.05 ± 6.03 years), (p < 0.001). Odds ratios (OR) were 1.236 (95% CI 1.055-1.447) and 1.002 (95% CI 1.000-1.004) for LAP index and ADAMTS4, respectively, in the IHH group. These two parameters found to have high predictivity for CVD risk in the IHH group (p = 0.009 and p = 0.028, respectively). CONCLUSION: The lower levels of ADAMTS4 in the POI group, when compared with the IHH patients pointed out that even limited hormone secretion and ovulation in the POI group, may have protective effect on cardiovascular system. The higher levels of ADAMTS4 and LAP index in the IHH group demonstrated the increased risk of these patients for CVD.
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Proteína ADAMTS4/sangre , Proteína ADAMTS9/sangre , Enfermedades Cardiovasculares/sangre , Hipogonadismo/sangre , Insuficiencia Ovárica Primaria/sangre , Adolescente , Adulto , Factores de Edad , Índice de Masa Corporal , Enfermedades Cardiovasculares/etiología , Estudios de Casos y Controles , Femenino , Humanos , Hipogonadismo/complicaciones , Insulina/sangre , Lípidos/sangre , Insuficiencia Ovárica Primaria/complicaciones , Factores de Riesgo , Circunferencia de la Cintura , Relación Cintura-Cadera , Adulto JovenRESUMEN
Duodenal nodularity is an uncommon endoscopic finding charac-trized by numerous visible mucosal nodules in the duodenum. It is important to consider giardiasis in patients with symptoms include abdominal pain, nausea, anorexia, diarrhea, vomiting, weight loss and abdominal distension. It is also important to remind giardiasis in patients with duodenal nodularity.
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Duodenitis/diagnóstico por imagen , Duodenitis/parasitología , Giardiasis/complicaciones , Adulto , Duodenitis/patología , Dispepsia/parasitología , Endoscopía Gastrointestinal , Femenino , Giardiasis/diagnóstico por imagen , Giardiasis/patología , Humanos , Pérdida de PesoRESUMEN
aullimary Investigation: The cause of discordance in dichorionic diamniotic (DD) twins is still unknown. The authors aimed to compare decorin (DCN) and oxidative/antioxidative state levels between the placentas of discordant and concordant twins. MATERIALS AND METHODS: Prospective study of 43 spontaneous DD twin pregnancies included and placentas samples taken from each twin and prepared for homogenization. Total oxidant/antioxidant status levels in placental tissue were determined by automated colorimetric method. Decorin levels were detected by using ELISA method; 23 of these were discordant and 20 of them were concordant. RESULTS: DCN levels in the placentas of the low birth-weight twins were significantly lower than the levels of the placentas of appropriate gestational age twins (p = 0.006). There were no statistically significant differences in total antioxidant status (TAS), total oxidant status (TOS), or arylesterase (ARES) levels in discordant (p = 0.631, p = 0.370, and p = 0.079, respectively) and in the placental DCN, TAS, TOS, or ARES levels of the concordant twins (p = 0.407, p = 0.035, p = 0.194, and p = 0.979, respectively). When the authors compared the twins of similar birth weight, the DCN, TAS, and TOS levels were significantly lower in the discordant twins (p < 0.001, p < 0.001, and p = 0.002, respectively). CONCLUSIONS: Decreased levels of DCN in discordant twin fetuses compared to the same birth weight-concordant twins shows that it contributes to disease pathogenesis.
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Antioxidantes/metabolismo , Peso al Nacer/fisiología , Decorina/análisis , Placenta , Embarazo Gemelar/fisiología , Gemelos Dicigóticos , Gemelos Monocigóticos , Adulto , Femenino , Edad Gestacional , Humanos , Placenta/metabolismo , Placenta/patología , Embarazo , Estudios Prospectivos , Estadística como AsuntoAsunto(s)
Coledocolitiasis/diagnóstico , Conducto Colédoco/anomalías , Conducto Cístico/anomalías , Conducto Hepático Común/anomalías , Adulto , Variación Anatómica , Colangiografía , Colangiopancreatografia Retrógrada Endoscópica , Colecistectomía , Coledocolitiasis/cirugía , Conducto Colédoco/diagnóstico por imagen , Conducto Cístico/diagnóstico por imagen , Conducto Hepático Común/diagnóstico por imagen , Humanos , MasculinoRESUMEN
Cryopreservation is the process of freezing and preserving cells and tissues at low temperatures. Controlled slow freezing and vitrification have successfully been used for cryopreservation of mammalian embryos. We investigated the effect of these two cryopreservation methods on in vitro produced four-cell stage bovine embryos which were classified according to their quality and separated into three groups. The first group was maintained as untreated controls (n = 350). Embryos of the second (n = 385) and the third (n = 385) groups were cryopreserved either by controlled slow freezing or by vitrification. Embryos in groups 2 and 3 were thawed after 1 day. Hundred embryos were randomly selected from the control group, and 100 morphologically intact embryos from the second and third group were thawed after 1 day and cultured to observe the development up to the blastocyst stage. The blastocyst development rate was 22% in the control group, 1% in the slow-freezing group and 3% in the vitrification group. Remaining embryos of all three groups were examined by light microscopy, transmission electron microscopy and immunofluorescence confocal microscopy with subsequent histological staining procedures. Cryopreservation caused degenerative changes at the ultra-structural level. Compared with vitrification, slow freezing caused an increased mitochondrial degeneration, cytoplasmic vacuolization, disruption of the nuclear and plasma membrane integrity, organelle disintegration, cytoskeletal damage, a reduced thickness of the zona pellucida and a formation of fractures in the zona pellucida. Further studies are required to understand and decrease the harmful effects of cryopreservation.
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Blastocisto/ultraestructura , Bovinos/embriología , Criopreservación/veterinaria , Técnicas de Cultivo de Embriones/veterinaria , Vitrificación , Animales , Bovinos/anatomía & histología , Crioprotectores/farmacología , Desarrollo Embrionario , Glicol de Etileno/farmacología , Microscopía Confocal/veterinaria , Microscopía Electrónica de Transmisión/veterinaria , Microscopía Fluorescente/veterinaria , Zona Pelúcida/fisiologíaRESUMEN
Splenic abscess are rare conditions. Since morbidity and mortality rates are high, immediate diagnosis should be required. Here we presented an ulcerative colitis patients who develops splenic abscess under anti tumor necrosis factor treatment.
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Absceso/diagnóstico , Colitis Ulcerosa/tratamiento farmacológico , Enfermedades del Bazo/diagnóstico , Factor de Necrosis Tumoral alfa/antagonistas & inhibidores , Factor de Necrosis Tumoral alfa/uso terapéutico , Absceso/etiología , Anciano , Colitis Ulcerosa/complicaciones , Humanos , Masculino , Enfermedades del Bazo/etiologíaRESUMEN
Mitochondrial neurogastrointestinal encephalomyopathy (MNGIE) is an autosomal recessive multisystem disorder caused by thymidine phosphorylase deficiency. Severe denutrition is almost constant during the course of the disease which leads to severe malnutrition and requires long-term parenteral nutrition in most cases. Patients with MNGIE syndrome and chronic intestinal pseudo-obstruction have a particularly poor prognosis and they usually die around 40 years of age. Gastrointestinal perforation associated with MNGIE is extremely rare. Herein we present our unique case with MNGIE associated abdominal esophageal perforation.
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Perforación del Esófago/etiología , Seudoobstrucción Intestinal/complicaciones , Encefalomiopatías Mitocondriales/complicaciones , Abdomen , Adulto , Humanos , Masculino , Distrofia Muscular Oculofaríngea , Oftalmoplejía/congénitoRESUMEN
INTRODUCTION: Although physiopathology of acute pancreatitis (AP) is not fully understood, the roles of reactive oxygen species (ROS) and changes of cytokines have been determined. AIM: To investigate anti-inflammatory and anti-oxidant effects of glycyrrhizin (GL) on taurocholate-induced AP in rats. MATERIALS AND METHODS: Thirty six rats were randomly divided into three groups as sham, AP and AP+GL (n=12 per group). AP was induced by 1 ml/kg body weight using 5% taurocholate injection into the biliopancreatic duct in groups II and III after clamping the hepatic duct. In groups III, GL (20 mg/kg) was given by oral gavage twice daily for 4 days. Group I and II did not receive any treatment. After the rats were killed; blood samples were taken to measure amylase, lipase, calcium, albumin, urea, glucose, AST and LDH assays before killing. Pancreatic tissue samples were also taken for biochemical analyses and histopathology. RESULTS: Amylase, lipase, AST and urea levels were significantly lower in the AP+GL group than in the AP group. Cytokines including IL-6, TNF-α and MPO levels were significantly lower in the AP+GL group than in the AP group. Even so there is no statistically difference between in the AP+GL group and the AP group in terms of pancreatic tissue IL-1ß, IL-6 and TNF-α levels. DISCUSSION: GL treatment significantly decreased pancreatic tissue MPO activities and MDA levels in the AP+GL group compared with the other groups (p = 0.001 and p = 0.05, respectively). Acinar cell necrosis, hemorrhage, and edema determined that were significantly lower in the AP+GL group than in the AP group (p < 0.001). CONCLUSIONS: GL treatment for acute necrotizing pancreatitis in rats suppressed the levels of pro-inflammatory cytokines, and caused a clear recovery of histological changes.
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Antiinflamatorios/uso terapéutico , Ácido Glicirrínico/uso terapéutico , Pancreatitis Aguda Necrotizante/tratamiento farmacológico , Animales , Citocinas/sangre , Masculino , Pancreatitis Aguda Necrotizante/inmunología , Pancreatitis Aguda Necrotizante/patología , Ratas , Ratas Sprague-DawleyRESUMEN
The aim of this study was to investigate the protective effects of taurine (Tau) on experimental acute pancreatitis (AP) in a rat model by measuring cytokines and oxidant stress markers. Forty rats were randomly divided into four groups: sham, AP, Tau and AP + Tau. AP was induced with sodium taurocholate. No treatment was given to the AP. All rats were killed 5 days later. Pancreatic tissues of rats and blood samples were obtained. Tau treatment significantly decreased serum amylase activity (p < 0.001), total injury score (p < 0.001), malondialdehyde levels (p < 0.001) and myeloperoxidase (MPO) activity (p < 0.001). There was no significant difference between the Tau and AP + Tau groups in serum and pancreatic tumor necrosis factor-α, interleukin (IL)-1ß and IL-6 levels (p = 1.000). Histopathologic scores in the AP + Tau and Tau groups were significantly lower compared with the AP group (both p < 0.001). These results showed that Tau reduces lipid peroxidation, amylase and MPO activities and the concentrations of proinflammatory cytokines secondary to AP and also increases superoxide dismutase and glutathione peroxidase activities in rats with sodium taurocholate-induced AP. It also has a marked ameliorative effect at histopathologic lesions. With these effects, Tau protects the cells from oxidative damage, reduces inflammation and promotes regression of pancreatic damage.
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Pancreatitis/prevención & control , Taurina/uso terapéutico , Enfermedad Aguda , Animales , Modelos Animales de Enfermedad , Interleucina-1beta/sangre , Interleucina-6/sangre , Masculino , Pancreatitis/sangre , Peroxidasa/metabolismo , Ratas , Ratas Sprague-Dawley , Especies Reactivas de Oxígeno/metabolismo , Superóxido Dismutasa/metabolismo , Factor de Necrosis Tumoral alfa/sangreRESUMEN
This study was aimed to determine staining intensity, cellular localization and distribution of the nitric oxide synthase (NOS) enzymes during the sexual cycle in the cow oviduct. Oviduct samples belonging to 20 cows, 10 of which were in the estrual phase and 10 in the luteal phase of the sexual cycle, were examined by an immunohistochemical procedure to determine the presence of the NOS enzymes. In the epithelial cells of the isthmus, endothelial NOS (eNOS) expression showed a strong positive reaction during the estrual phase and a weak positive reaction during the luteal phase in the endothelium and smooth muscle of the blood vessels found in the serosa and lamina propria. eNOS expression was not observed in the epithelium of either the ampulla or the fimbria in the two particular phases of the sexual cycle. The eNOS reactions observed in the blood vessel wall in these regions were stronger during the estrual phase. eNOS activity was not observed in the tunica muscularis in any of the regions of the oviduct. During the estrual phase, it was observed that inducible NOS expression showed a stronger positive reaction in the epithelium and muscle layer of the isthmus and ampulla and in the epithelium of the fimbria, compared to the luteal phase. Neuronal NOS immunoreactivity was observed in the epithelial cells of all oviduct regions and in the muscle layer of the isthmus and ampulla and did not display any significant difference between the estrual and luteal phases.
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Bovinos/fisiología , Ciclo Estral/fisiología , Trompas Uterinas/enzimología , Óxido Nítrico Sintasa de Tipo III/metabolismo , Óxido Nítrico Sintasa de Tipo II/metabolismo , Óxido Nítrico Sintasa de Tipo I/metabolismo , Animales , Femenino , Regulación Enzimológica de la Expresión Génica/fisiología , Óxido Nítrico Sintasa de Tipo I/genética , Óxido Nítrico Sintasa de Tipo II/genética , Óxido Nítrico Sintasa de Tipo III/genéticaRESUMEN
INTRODUCTION: In this retrospective study, we aimed to evaluate preoperative predictive risk factors for development of pouchitis in the ulcerative colitis (UC) patients with ileal pouch-anal anastomosis (IPAA). METHODS: The records of UC patients who underwent IPAA surgery and were under follow-up in the inflammatory bowel disease (IBD) clinic of our hospital between January 1994 and September 2009 were retrieved. Preoperative clinical, biochemical, and endoscopic findings, as well as preoperative endoscopic activity index (EAI), preoperative disease activity index (DAI) and operative characteristics were recorded. Patients with endoscopic, histological and clinical findings consistent with pouchitis were identified. RESULTS: Out of a total of 49 patients who underwent IPAA for UC, pouchitis was identified in 20 (40.8%) of them. Overall, 37 (75.5%) patients had chronic active disease, eight (16.3%) patients had chronic intermittent disease with frequent relapses, and four (8.2%) patients had fulminant colitis prior to surgery. There was a statistically significant difference (P=0.02) among these patients for the development of pouchitis in postoperative period. The mean EAI (10.1 vs. 8.7, P=0.02) and DAI (10.0 vs. 8.6, P<0.01) in patients with pouchitis were significantly higher than that of patients who did not develop pouchitis. Multivariate analysis revealed steroid dependency (P=0.02), and a higher DAI (P=0.02) to be independent risk factors for the development of pouchitis. CONCLUSION: A more severe preoperative clinical course and steroid dependency, as well as higher endoscopic and disease activity scores may be useful as preoperative predictors of subsequent pouchitis in UC patients undergoing IPAA surgery.
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Colitis Ulcerosa/cirugía , Reservorios Cólicos/efectos adversos , Íleon/cirugía , Reservoritis/epidemiología , Reservoritis/etiología , Adulto , Anastomosis Quirúrgica/efectos adversos , Femenino , Humanos , Masculino , Periodo Preoperatorio , Estudios Retrospectivos , Medición de RiesgoRESUMEN
The aim of this study was to evaluate the effects of bleaching and delayed bonding on the shear bond strengths of metal and ceramic brackets bonded with light and chemically cure composite resin to human enamel. One hundred and twenty extracted human premolar teeth were randomly divided into three groups of 40 each. The first two groups were bleached with 20 per cent carbamide peroxide (CP) at-home bleaching agent. No bleaching procedures were applied to the third group and served as control. The first two and control groups were divided into equal subgroups according to different adhesive-bracket combinations. Specimens in group 1 (n = 40) were bonded 24 hours after bleaching process was completed while the specimens in group 2 (n = 40) were bonded 14 days after. The specimens in all groups were debonded with a Universal testing machine while the modified adhesive remnant index was used to evaluate fracture properties. No statistically significant differences were found between the shear bond strengths of metal and ceramic brackets bonded to bleached enamel after 24 hours, 14 days, and unbleached enamel with light or chemical cure adhesives (P > 0.05). The mode of failure was mostly at the bracket/adhesive interface and cohesive failures within the resin were also observed. Our findings indicated that at-home bleaching agents that contain 20 per cent CP did not significantly affect the shear bond strength of metal and ceramic orthodontic brackets to enamel when bonding is performed 24 hours or 14 days after bleaching.