Штанги для горизонтально направленного бурения

В статті наведено технічні дані про конструкцію та експлуатаційні вимоги до бурових штанг горизонтально спрямованого буріння свердловин

High Risk of Advanced Colorectal Neoplasia in Patients With Primary Sclerosing Cholangitis Associated With Inflammatory Bowel Disease

Cellular mechanisms in basic and clinical gastroenterology and hepatolog

Consecutive negative findings on colonoscopy during surveillance predict a low risk of advanced neoplasia in patients with inflammatory bowel disease with long-standing colitis: results of a 15-year multicentre, multinational cohort study

Cellular mechanisms in basic and clinical gastroenterology and hepatolog

Concise Synthesis of (+)- allo

3-Methyl vinyl aziridine undergoes a mild MgI2-promoted S(N)2' ring opening and concomitant cyclization with fumarate Michael acceptors to give trisubstituted pyrrolidines. The process is efficient and highly diastereoselective. This methodology has been applied to a concise asymmetric synthesis of (+)-allo-kainic acid.</p

Biomarkers for inflammation and surveillance strategies in inflammatory bowel disease

Chronic inflammation of the colonic mucosa, as observed in patients with inflammatory bowel disease (IBD), is associated with an increased risk of colorectal cancer (CRC). Endoscopic surveillance aimed at the detection of dysplasia and asymptomatic CRC is therefore recommended in order to mitigate this risk. In part 1 of this thesis we critically explored various aspects of endoscopic surveillance in patients with IBD. We showed that the longer surveillance intervals as recommended in the new British guidelines for surveillance are preferable, as they offer a significant reduction in colonoscopic workload of 22%. A potential drawback of a longer interval between two surveillance procedures is the increased risk of CRC developing between two surveillance colonoscopies, also known as interval CRC.We showed that the overall incidence of these interval CRCs was low among IBD patients undergoing regular endoscopic surveillance at the appropriate interval supporting the implementation of longer surveillance intervals. Traditionally, any visible lesion containing histologically confirmed dysplasia was known as a ”dysplasia associated lesion or mass” (DALM) which was associated with a high risk of CRC. Recent studies showed that the sub-group of lesions with an endoscopic appearance resembling that of sporadic adenomas (subcategorized as adenoma-like DALM) also found in patients without IBD have a lower risk of CRC.In contrast to these studies, we found that for IBD patients with an adenoma at baseline, the incidence of CRC during follow-up was higher compared to IBD patients without adenoma and non-IBD patients with an adenoma.In addition, we showed that there is a low agreement among endoscopists when classifying lesions as either adenoma-like DALM or non-adenoma-like DALM, suggesting that this classification is ineffective. Several studies have demonstrated that dye-based chromoendoscopy aimed at highlighting subtle changes in pit pattern can increase dysplasia detection rates compared to white-light endoscopy with random biopsies.Therefore, chromoendoscopy is now recommended as the preferred surveillance method in most international guidelines. In contrast to these previous studies,we showed that the dysplasia detection rate did not increase after the implementation of chromoendoscopy as the primary surveillance method. As IBD is characterized by relapsing episodes of inflammation, constant monitoring for the presence of inflammation is vital in evaluating response to treatment. In part 2 of this thesis we aimed to study the value of fecal calprotectin, a non-invasive marker for inflammation. We reported that fecal hemoglobin had a similar diagnostic accuracy for the detection of inflammation as calprotectin in patients with CD and UC. We also showed that low calprotectin levels could predict a sustained clinical remission during follow-up in IBD patients with complete mucosal healing. These results support the concept of trying to achieve “extreme deep remission” defined as clinical and endoscopic remission in combination with a low calprotectin level. Finally, we reported that low fecal calprotectin could accurately identify IBD patients without active inflammation in which CRC surveillance is most effective. Using a high cut-off level for calprotectin of 539 mg/kg, the number of ineffective procedures could be reduced from 14% to 3%

Low fecal calprotectin predicts sustained clinical remission in inflammatory bowel disease patients: a plea for deep remission

Item does not contain fulltextBACKGROUND AND AIMS: Mucosal healing has become the treatment goal in patients with ulcerative colitis (UC) and Crohn's disease (CD). Whether low fecal calprotectin levels and histological healing combined with mucosal healing is associated with a further reduced risk of relapses is unknown. METHODS: Patients with CD, UC or inflammatory bowel disease-unclassified (IBD-U) scheduled for surveillance colonoscopy collected a stool sample prior to bowel cleansing. Only patients with mucosal healing (MAYO endoscopic score of 0) were included. Fecal calprotectin was measured using a quantitative enzyme-linked immunosorbent assay (R-Biopharm, Germany). Biopsies were obtained from four colonic segments, and histological disease severity was assessed using the Geboes scoring system. Patients were followed until the last outpatient clinic visit or the development of a relapse, which was defined as IBD-related hospitalization, surgery or step-up in IBD medication. RESULTS: Of the 164 patients undergoing surveillance colonoscopy, 92 patients were excluded due to active inflammation or missing biopsies. Of the remaining 72 patients (20 CD, 52 UC or IBD-U), six patients (8%) relapsed after a median follow-up of 11 months (range 5-15 months). Median fecal calprotectin levels at baseline were significantly higher for patients who relapsed compared with patients who maintained remission (284 mg/kg vs. 37 mg/kg. p < 0.01). Fecal calprotectin below 56 mg/kg was found to optimally predict absence of relapse during follow-up with 64% sensitivity, 100% specificity, 100% negative predictive value and 20% positive predictive value. The presence or absence of active inflammation determined by Geboes cut-off score of 3.1 was less strongly associated with the risk of relapse (64% sensitivity, 33% specificity, 9% negative predictive value and 92% positive predictive value. CONCLUSION: Low calprotectin levels identify IBD patients who remain in stable remission during follow-up

Chromoendoscopy for Surveillance in Inflammatory Bowel Disease Does Not Increase Neoplasia Detection Compared With Conventional Colonoscopy With Random Biopsies: Results From a Large Retrospective Study

Item does not contain fulltextOBJECTIVES: Randomized trials demonstrated that chromoendoscopy is superior to white light endoscopy with random biopsy sampling (WLE) for the detection of dysplasia in patients with inflammatory bowel disease (IBD). Whether implementing chromoendoscopy can increase the detection of dysplasia in clinical practice is unknown. METHODS: Patients with ulcerative colitis (UC) and Crohn's disease (CD) undergoing colonoscopic surveillance between January 2000 and November 2013 in three referral centers were identified using the patients' medical records. In recent years, the use of high-definition chromoendoscopy was adopted in all three centers using segmental pancolonic spraying of 0.1% methylene blue or 0.3% indigo carmine (chromoendoscopy group). Previously, surveillance was performed employing WLE with random biopsies every 10 cm (WLE group). The percentage of colonoscopies with dysplasia was compared between both groups. RESULTS: A total of 440 colonoscopies in 401 patients were performed using chromoendoscopy and 1,802 colonoscopies in 772 patients using WLE. Except for a higher number of CD patients with extensive disease and more patients with a first-degree relative with colorectal cancer (CRC) in the chromoendoscopy group, the known risk factors for IBD-associated CRC were comparable between both groups. Dysplasia was detected during 48 surveillance procedures (11%) in the chromoendoscopy group as compared with 189 procedures (10%) in the WLE group (P=0.80). Targeted biopsies yielded 59 dysplastic lesions in the chromoendoscopy group, comparable to the 211 dysplastic lesions detected in the WLE group (P=0.30). CONCLUSIONS: Despite compelling evidence from randomized trials, implementation of chromoendoscopy for IBD surveillance did not increase dysplasia detection compared with WLE with targeted and random biopsies

Clinical implications of low grade dysplasia found during inflammatory bowel disease surveillance: a retrospective study comparing chromoendoscopy and white-light endoscopy

Cellular mechanisms in basic and clinical gastroenterology and hepatolog

Low interobserver agreement among endoscopists in differentiating dysplastic from non-dysplastic lesions during inflammatory bowel disease colitis surveillance

Item does not contain fulltextOBJECTIVES: During endoscopic surveillance in patients with longstanding colitis, a variety of lesions can be encountered. Differentiation between dysplastic and non-dysplastic lesions can be challenging. The accuracy of visual endoscopic differentiation and interobserver agreement (IOA) has never been objectified. MATERIAL AND METHODS: We assessed the accuracy of expert and nonexpert endoscopists in differentiating (low-grade) dysplastic from non-dysplastic lesions and the IOA among and between them. An online questionnaire was constructed containing 30 cases including a short medical history and an endoscopic image of a lesion found during surveillance employing chromoendoscopy. RESULTS: A total of 17 endoscopists, 8 experts, and 9 nonexperts assessed all 30 cases. The overall sensitivity and specificity for correctly identifying dysplasia were 73.8% (95% confidence interval (CI) 62.1-85.4) and 53.8% (95% CI 42.6-64.7), respectively. Experts showed a sensitivity of 76.0% (95% CI 63.3-88.6) versus 71.8% (95% CI 58.5-85.1, p = 0.434) for nonexperts, the specificity 61.0% (95% CI 49.3-72.7) versus 47.1% (95% CI 34.6-59.5, p = 0.008). The overall IOA in differentiating between dysplastic and non-dysplastic lesions was fair 0.24 (95% CI 0.21-0.27); for experts 0.28 (95% CI 0.21-0.35) and for nonexperts 0.22 (95% CI 0.17-0.28). The overall IOA for differentiating between subtypes was fair 0.21 (95% CI 0.20-0.22); for experts 0.19 (95% CI 0.16-0.22) and nonexpert 0.23 (95% CI 0.20-0.26). CONCLUSION: In this image-based study, both expert and nonexpert endoscopists cannot reliably differentiate between dysplastic and non-dysplastic lesions. This emphasizes that all lesions encountered during colitis surveillance with a slight suspicion of containing dysplasia should be removed and sent for pathological assessment

Low Rate of Dysplasia Detection in Mucosa Surrounding Dysplastic Lesions in Patients Undergoing Surveillance for Inflammatory Bowel Diseases

Cellular mechanisms in basic and clinical gastroenterology and hepatolog