63 resultados para Colonic polyps
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Hyperkalemia is a common life-threatening problem in hemodialysis patients. Because glycyrrhetinic acid (GA) inhibits the enzyme 11beta-hydroxy-steroid dehydrogenase II and thereby increases cortisol availability to the colonic mineralocorticoid receptor, it has the potential to lower serum potassium concentrations. To test this, 10 patients in a 6 month prospective, double-blind, placebo-controlled crossover study were given cookies or bread rolls supplemented with glycyrrhetinic acid or placebo. Twenty-four-hour blood pressure measurements were performed at baseline and week 6 and 12 of each treatment period. The ratio of plasma cortisol/cortisone was significantly increased in all patients on GA as compared to baseline or placebo, indicating appropriate enzyme inhibition. Nine of the 10 patients had a persistent decrease in predialysis serum potassium concentration. On GA, mean predialysis serum potassium was significantly lower than at baseline or on placebo. On placebo, serum potassium was significantly elevated above the upper limit of normal in 76% compared to 30% of measurements during GA treatment. Furthermore, on this treatment the frequency of severe hyperkalemia significantly decreased from 9% to 0.6%. No differences were found in parameters reflecting sodium retention. Although these studies show that prolonged GA supplementation persistently lowers serum potassium in dialysis patients, a long-term toxicity study will be mandatory before we recommend the routine use of this treatment.
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Screening for colorectal cancer (CRC) is associated with reduced CRC mortality, but low screening rates have been reported in several settings. The aim of the study was to assess predictors of low CRC screening in Switzerland. A retrospective cohort of a random sample of 940 patients aged 50-80 years followed for 2 years from four Swiss University primary care settings was used. Patients with illegal residency status and a history of CRC or colorectal polyps were excluded. We abstracted sociodemographic data of patients and physicians, patient health status, and indicators derived from RAND's Quality Assessment Tools from medical charts. We defined CRC screening as colonoscopy in the last 10 years, flexible sigmoidoscopy in the last 5 years, or fecal occult blood testing in the last 2 years. We used bivariate and multivariate logistic regression analyses. Of 940 patients (mean age 63.9 years, 42.7% women), 316 (33.6%) had undergone CRC screening. In multivariate analysis, birthplace in a country outside of Western Europe and North America [odds ratio (OR) 0.65, 95% confidence interval (CI) 0.45-0.97], male sex of the physician in charge (OR 0.67, 95% CI 0.50-0.91), BMI 25.0-29.9 kg/m2 (OR 0.66, CI 0.46-0.96) and at least 30.0 kg/m2 (OR 0.61, CI 0.40-0.90) were associated with lower CRC screening rates. Obesity, overweight, birthplace outside of Western Europe and North America, and male sex of the physician in charge were associated with lower CRC screening rates in Swiss University primary care settings. Physician perception of obesity and its impact on their recommendation for CRC screening might be a target for further research.
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PURPOSE Neural invasion (NI) is a histopathologic feature of colon cancer that receives little consideration. Therefore, we conducted a morphologic and functional characterization of NI in colon cancer. EXPERIMENTAL DESIGN NI was investigated in 673 patients with colon cancer. Localization and severity of NI was determined and related to patient's prognosis and survival. The neuro-affinity of colon cancer cells (HT29, HCT-116, SW620, and DLD-1) was compared with pancreatic cancer (T3M4 and SU86.86) and rectal cancer cells (CMT-93) in the in vitro three-dimensional (3D)-neural-migration assay and analyzed via live-cell imaging. Immunoreactivity of the neuroplasticity marker GAP-43, and the neurotrophic-chemoattractant factors Artemin and nerve growth factor (NGF), was quantified in colon cancer and pancreatic cancer nerves. Dorsal root ganglia of newborn rats were exposed to supernatants of colon cancer, rectal cancer, and pancreatic cancer cells and neurite density was determined. RESULTS NI was detected in 210 of 673 patients (31.2%). Although increasing NI severity scores were associated with a significantly poorer survival, presence of NI was not an independent prognostic factor in colon cancer. In the 3D migration assay, colon cancer and rectal cancer cells showed much less neurite-targeted migration when compared with pancreatic cancer cells. Supernatants of pancreatic cancer and rectal cancer cells induced a much higher neurite density than those of colon cancer cells. Accordingly, NGF, Artemin, and GAP-43 were much more pronounced in nerves in pancreatic cancer than in colon cancer. CONCLUSION NI is not an independent prognostic factor in colon cancer. The lack of a considerable biologic affinity between colon cancer cells and neurons, the low expression profile of colonic nerves for chemoattractant molecules, and the absence of a major neuroplasticity in colon cancer may explain the low prevalence and impact of NI in colon cancer.
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Immune responses against intestinal microbiota contribute to the pathogenesis of inflammatory bowel diseases (IBD) and involve CD4(+) T cells, which are activated by major histocompatibility complex class II (MHCII) molecules on antigen-presenting cells (APCs). However, it is largely unexplored how inflammation-induced MHCII expression by intestinal epithelial cells (IEC) affects CD4(+) T cell-mediated immunity or tolerance induction in vivo. Here, we investigated how epithelial MHCII expression is induced and how a deficiency in inducible epithelial MHCII expression alters susceptibility to colitis and the outcome of colon-specific immune responses. Colitis was induced in mice that lacked inducible expression of MHCII molecules on all nonhematopoietic cells, or specifically on IECs, by continuous infection with Helicobacter hepaticus and administration of interleukin (IL)-10 receptor-blocking antibodies (anti-IL10R mAb). To assess the role of interferon (IFN)-γ in inducing epithelial MHCII expression, the T cell adoptive transfer model of colitis was used. Abrogation of MHCII expression by nonhematopoietic cells or IECs induces colitis associated with increased colonic frequencies of innate immune cells and expression of proinflammatory cytokines. CD4(+) T-helper type (Th)1 cells - but not group 3 innate lymphoid cells (ILCs) or Th17 cells - are elevated, resulting in an unfavourably altered ratio between CD4(+) T cells and forkhead box P3 (FoxP3)(+) regulatory T (Treg) cells. IFN-γ produced mainly by CD4(+) T cells is required to upregulate MHCII expression by IECs. These results suggest that, in addition to its proinflammatory roles, IFN-γ exerts a critical anti-inflammatory function in the intestine which protects against colitis by inducing MHCII expression on IECs. This may explain the failure of anti-IFN-γ treatment to induce remission in IBD patients, despite the association of elevated IFN-γ and IBD.
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Intestinal bacterial metabolites are an important communication tool between the host immune system and the commensal microbiota to establish mutualism. In a recent paper published in Science, Wendy Garrett and her colleagues report an exciting role of the three most abundant microbial-derived short-chain fatty acids (SCFA), acetic acid, propionic acid and butyric acid, in colonic regulatory T cell (cTreg) homeostasis.
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Thymic stromal lymphopoietin (TSLP) is constitutively expressed in the intestine and is known to regulate inflammation in models of colitis. We show that steady-state TSLP expression requires intestinal bacteria and has an important role in limiting the expansion of colonic T helper type 17 (Th17) cells. Inappropriate expansion of the colonic Th17 cells occurred in response to an entirely benign intestinal microbiota, as determined following the colonization of germ-free C57BL/6 or TSLPR(-/-) mice with the altered Schaedler flora (ASF). TSLP-TSLPR (TSLP receptor) interactions also promoted the expansion of colonic Helios(-)Foxp3(+) regulatory T cells, necessary for the control of inappropriate Th17 responses following ASF bacterial colonization. In summary, these data reveal an important role for TSLP-TSLPR signaling in promoting steady-state mutualistic T-cell responses following intestinal bacterial colonization.
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Migration of naïve and activated lymphocytes is regulated by the expression of various molecules such as chemokine receptors and ligands. CD69, the early activation marker of C-type lectin domain family, is also shown to regulate the lymphocyte migration by affecting their egress from the thymus and secondary lymphoid organs. Here, we aimed to investigate the role of CD69 in accumulation of CD4 T cells in intestine using murine models of inflammatory bowel disease. We found that genetic deletion of CD69 in mice increases the expression of the chemokines CCL-1, CXCL-10 and CCL-19 in CD4(+) T cells and/or CD4(-) cells. Efficient in vitro migration of CD69-deficient CD4 T cells toward the chemokine stimuli was the result of increased expression and/or affinity of chemokine receptors. In vivo CD69(-/-) CD4 T cells accumulate in the intestine in higher numbers than B6 CD4 T cells as observed in competitive homing assay, dextran sodium sulphate (DSS)-induced colitis and antigen-specific transfer colitis. In DSS colitis CD69(-/-) CD4 T cell accumulation in colonic lamina propria (cLP) was associated with increased expression of CCL-1, CXCL-10 and CCL-19 genes. Furthermore, treatment of DSS-administrated CD69(-/-) mice with the mixture of CCL-1, CXCL-10 and CCL-19 neutralizing Abs significantly decreased the histopathological signs of colitis. Transfer of OT-II×CD69(-/-) CD45RB(high) CD4 T cells into RAG(-/-) hosts induced CD4 T cell accumulation in cLP. This study showed CD69 as negative regulator of inflammatory responses in intestine as it decreases the expression of chemotactic receptors and ligands and reduces the accumulation of CD4 T cells in cLP during colitis.
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PURPOSE To analyze available evidence on the incidence of anatomical variations or disease of the maxillary sinuses as identified by cone beam computed tomography (CBCT) in dentistry. MATERIALS AND METHODS A focused question was developed to search the electronic databases MEDLINE, EMBASE, the Cochrane Oral Health Group Trials Register, and CENTRAL and identify all relevant papers published between 1980 and January 19, 2013. Unpublished literature at ClinicalTrials.gov, in the National Research Register, and in the Pro-Quest Dissertation Abstracts and Thesis database was also included. Studies were included irrespective of language. These results were supplemented by hand and gray literature searches. RESULTS Twenty-two studies were identified. Twenty were retrospective cohort studies, one was a prospective cohort study, and one was a case control study. The main indication for CBCT was dental implant treatment planning, and the majority of studies used a small field of view for imaging. The most common anatomical variations included increased thickness of the sinus membrane, the presence of sinus septa, and pneumatization. Reported sinus disease frequency varied widely, ranging from 14.3% to 82%. There was a wide range in the reported prevalence of mucosal thickening related to apical pathology, the degree of lumenal opacification, features of sinusitis, and the presence of retention cysts and polyps. More pathologic findings in the maxillary sinus were reported in men than in women, and the medial wall and sinus floor were most frequently affected. CONCLUSION CBCT is used primarily to evaluate bony anatomy and to screen for overt pathology of the maxillary sinuses prior to dental implant treatment. Differences in the classification of mucosal findings are problematic in the consistent and valid assessment of health and disease of the maxillary sinus.
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Pai syndrome is a rare congenital disorder characterized by cutaneous polyps of the face, pericallosal lipoma and median cleft lip. We report on a newborn girl with a variant of Pai syndrome presenting with all typical findings except a median cleft. In addition, fetal sonography and MRI showed the unique intrauterine evolution of a cephalocele into an atretic cephalocele.
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BACKGROUND The optimal crystalloid solution to use perioperatively in patients undergoing open radical cystectomy remains unclear. Many of the fluids used for intravenous hydration contain supraphysiologic concentrations of chloride, which can induce hyperchloremia and metabolic acidosis, resulting in renal vasoconstriction and decreased renal function. In addition, patients receiving less fluid and less sodium show faster recovery of gastrointestinal (GI) function after colonic surgery. METHODS AND DESIGN This is an investigator-initiated, single-center, randomized, controlled, parallel group trial with assessor-blinded outcome assessment, in the Department of Urology, University Hospital Bern, Switzerland. The study will involve 44 patients with bladder cancer scheduled for radical cystectomy and urinary diversion. The primary outcome is the duration between the end of surgery and the return of the GI function (first defecation). Secondary outcomes are fluid balance (body weight difference postoperatively versus preoperatively) and the incidence of kidney function disorders according to the Risk-Injury-Failure-Loss-End Stage Renal Disease (RIFLE classification). An equal number of patients are allocated to receive Ringerfundin® solution or a glucose/potassium-based balanced crystalloid solution as baseline infusion during the entire time that intravenous administration of fluid is necessary during the perioperative period. The randomized crystalloid solution is infused at a rate of 1 ml/kg/h until the bladder has been removed, followed by 3 ml/kg/h until the end of surgery. Postoperative hydration is identical in both groups and consists of 1,500 ml of the randomized crystalloid solution per 24 hours. Postoperative patient care is identical in both groups; patients are allowed to drink clear fluids immediately after surgery, and liquid diet is started on postoperative day 1, as well as active mobilization and the use of chewing gum. Body weight is measured daily in the morning. Time of first flatus and first defecation are recorded. DISCUSSION This trial assesses the benefits and harms of two different balanced crystalloid solutions for perioperative fluid management in patients undergoing open radical cystectomy with urinary diversion, with regard to return of GI function and effects on postoperative renal function. TRIAL REGISTRATION Current Controlled Trials ISRCTN32976792 (registered on November 21 2013).
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BACKGROUND It is unknown why patients with extensive ulcerative colitis (UC) have a higher risk of colorectal cancer compared with patients with left-sided UC. This study characterizes the inflammatory processes in left-sided UC, pancolitis, and UC-associated dysplasia at the transcriptional level to identify potential biomarkers and transcripts of importance for the carcinogenic behavior of chronic inflammation. METHODS The Affymetrix GeneChip Human Genome U133 Plus 2.0 was applied on colonic biopsies from UC patients with left-sided UC, pancolitis, dysplasia, and controls. Reverse transcription polymerase chain reaction and immunohistochemistry were performed for validating selected transcripts in the initial cohort and in 2 independent cohorts of patients with UC. Microarray data were analyzed by principal component analysis, and reverse transcription polymerase chain reaction and immunohistochemistry data by the Wilcoxon's rank-sum test. RESULTS The principal component analysis results revealed separate clusters for left-sided UC, pancolitis, dysplasia, and controls. Close clustering of dysplastic and pancolitic samples indicated similarities in gene expression. Indeed, 101 and 656 parallel upregulated and downregulated transcripts, respectively, were identified in specimens from dysplasia and pancolitis. Validation of selected transcripts hereof identified insulin receptor alpha (INSRA) and MAP kinase interacting serine/threonine kinase 2 (MKNK2) with an enhanced expression in dysplasia compared with left-sided UC and controls, whereas laminin γ2 (LAMC2) was found with a lower expression in dysplasia compared with the remaining 3 groups. CONCLUSIONS This study demonstrates pancolitis and left-sided UC as distinct inflammatory processes at the transcriptional level, and identifies INSRA, MKNK2, and LAMC2 as potential critical transcripts in the inflammation-driven preneoplastic process of UC.
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BACKGROUND Cyclooxygenase-2 (COX-2) is a key enzyme in the synthesis of pro-inflammatory prostaglandins and 5-lipoxygenase (5-LO) is the major source of leukotrienes. Their role in IBD has been demonstrated in humans and animal models, but not in dogs with chronic enteropathies (CCE). HYPOTHESIS COX-2 and 5-LO are upregulated in dogs with CCE. ANIMALS Fifteen healthy control dogs (HCD), 10 dogs with inflammatory bowel disease (IBD), and 15 dogs with food-responsive diarrhea (FRD). METHODS Prospective study. mRNA expression of COX-2, 5-LO, IL-1b, IL-4, IL-6, TNF, IL-10 and TFG-β was evaluated by quantitative real-time RT-PCR in duodenal and colonic biopsies before and after treatment. RESULTS COX-2 expression in the colon was significantly higher in IBD and FRD before and after treatment (all P < .01). IL-1b was higher in FRD in the duodenum after treatment (P = .021). TGF-β expression was significantly higher in the duodenum of HCD compared to FRD/IBD before treatment (both P < .001) and IBD after treatment (P = .012). There were no significant differences among groups and within groups before and after treatment for IL-4, IL-6, TNF, and IL-10. There was a significant correlation between COX-2 and IL-1b in duodenum and colon before treatment in FRD and IBD, whereas 5-LO correlated better with IL-6 and TNF. IL-10 and TGF-β usually were correlated. CONCLUSIONS AND CLINICAL IMPORTANCE COX-2 is upregulated in IBD and FRD, whereas IL-1b and TGF-β seem to be important pro- and anti-inflammatory cytokines, respectively. The use of dual COX/5-LO inhibitors could be an interesting alternative in the treatment of CCE.
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Aldosterone promotes electrogenic sodium reabsorption through the amiloride-sensitive epithelial sodium channel (ENaC). Here, we investigated the importance of ENaC and its positive regulator channel-activating protease 1 (CAP1/Prss8) in colon. Mice lacking the αENaC subunit in colonic superficial cells (Scnn1a(KO)) were viable, without fetal or perinatal lethality. Control mice fed a regular or low-salt diet had a significantly higher amiloride-sensitive rectal potential difference (∆PDamil) than control mice fed a high-salt diet. In Scnn1a(KO) mice, however, this salt restriction-induced increase in ∆PDamil did not occur, and the circadian rhythm of ∆PDamil was blunted. Plasma and urinary sodium and potassium did not change with regular or high-salt diets or potassium loading in control or Scnn1a(KO) mice. However, Scnn1a(KO) mice fed a low-salt diet lost significant amounts of sodium in their feces and exhibited high plasma aldosterone and increased urinary sodium retention. Mice lacking the CAP1/Prss8 in colonic superficial cells (Prss8(KO)) were viable, without fetal or perinatal lethality. Compared with controls, Prss8(KO) mice fed regular or low-salt diets exhibited significantly reduced ∆PDamil in the afternoon, but the circadian rhythm was maintained. Prss8(KO) mice fed a low-salt diet also exhibited sodium loss through feces and higher plasma aldosterone levels. Thus, we identified CAP1/Prss8 as an in vivo regulator of ENaC in colon. We conclude that, under salt restriction, activation of the renin-angiotensin-aldosterone system in the kidney compensated for the absence of ENaC in colonic surface epithelium, leading to colon-specific pseudohypoaldosteronism type 1 with mineralocorticoid resistance without evidence of impaired potassium balance.
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Diverticulitis is a common disease in western countries and its incidence is increasing especially among young patients. Colonic diverticulosis, incidentally diagnosed by endoscopy or CT-scanning, has no immediate clinical consequences. Progression to diverticulitis develops in only 4 % of cases. In the last decades management of diverticular disease evolved and expectative treatment and less invasive techniques have gained importance. Elective resection has traditionally been advised after a second episode of diverticulitis or after a first episode if the patient was less than 50 years of age or complicated disease occurred. Recent changes in understanding the natural history of diverticular disease have substantially modified treatment paradigms. Elective resection in case of recurrent diverticular disease should be performed on a individual basis and in cases with complications like intestinal obstruction or fistulas. Primary anastomosis is an option even in emergency surgery due to colonic perforation, while diverting operations are indicated for selected patient groups with a high risk profile. Several prospective studies showed good results for laparoscopic drainage and lavage in the setting of perforated diverticulitis with generalized peritonitis, though this concept needs to be controlled with randomized clinical trials before application into the daily practice. This article should provide a short overview of trends in the surgical treatment of diverticulitis, help to understand the natural history of the disease and thereby explain the currently lower frequency of surgical interventions for diverticulitis.
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The aim of this study was to review our experience with laparoscopic end colostomy closure. A retrospective review of a prospectively entered database was performed. Proportions and continuous variables were compared using the Fisher's exact and the Mann-Whitney U tests, respectively. Within the study period, 53 patients underwent closure of end colostomies. The main reasons for the colonic resections were perforated diverticulitis (52.7%) and neoplasms (20.8%). In 28 patients (53%), laparoscopic closure (LC) was attempted. Demographics did not differ between the attempted LC and the primary open closure (OC) group. The conversion rate from an LC to an OC was 50 per cent (14 of 28), mostly as a result of adhesions (71.4%). Hospital length of stay (HLOS) was significantly longer for the OC than with the attempted LC group (15.4 ± 11.9 days vs 11.3 ± 8.5 days, P = 0.046). The overall complication rate was not different between the completed LC and the OC groups (43 vs 56%, P = 0.634). The majority of complications detected (91.1%) were minor and could be treated conservatively. The role of laparoscopy to close end colostomies is questionable, because the conversion rate is high. However, a shorter HLOS can be expected when laparoscopy is successful. To reduce morbidity resulting from prolonged operation times, it is crucial to convert early and pre-emptively if hostile adhesions are found.