Yogesh Shastri

Prospective evaluation of faecal neutrophil‐derived proteins in identifying intestinal inflammation: combination of parameters does not improve diagnostic accuracy of calprotectin

Background  Differentiating symptoms of irritable bowel syndrome from those of organic intestinal disease is a common clinical problem. Several neutrophil‐derived proteins have been proposed as a marker of inflammatory bowel disease.

Gastroenteric tube feeding: techniques, problems and solutions.

Gastroenteric tube feeding plays a major role in the management of patients with poor voluntary intake, chronic neurological or mechanical dysphagia or gut dysfunction, and patients who are critically ill. However, despite the benefits and widespread use of enteral tube feeding, some patients experience complications. This review aims to discuss and compare current knowledge regarding the clinical application of enteral tube feeding, together with associated complications and special aspects. We conducted an extensive literature search on PubMed, Embase and Medline using index terms relating to enteral access, enteral feeding/nutrition, tube feeding, percutaneous endoscopic gastrostomy/jejunostomy, endoscopic nasoenteric tube, nasogastric tube, and refeeding syndrome. The literature showed common routes of enteral access to include nasoenteral tube, gastrostomy and jejunostomy, while complications fall into four major categories: mechanical, e.g., tube blockage or removal; gastrointestinal, e.g., diarrhea; infectious e.g., aspiration pneumonia, tube site infection; and metabolic, e.g., refeeding syndrome, hyperglycemia. Although the type and frequency of complications arising from tube feeding vary considerably according to the chosen access route, gastrointestinal complications are without doubt the most common. Complications associated with enteral tube feeding can be reduced by careful observance of guidelines, including those related to food composition, administration rate, portion size, food temperature and patient supervision.

Prospective Multicenter Study Evaluating Fecal Calprotectin in Adult Acute Bacterial Diarrhea

BACKGROUND Every year, about 2.2 million deaths occur worldwide due to diarrhea. Reliable diagnosis of patients with acute infectious diarrhea remains a formidable challenge to the clinicians. This is the first study reporting use of fecal calprotectin in diagnosing acute diarrhea. The aim was to compare the diagnostic accuracy of fecal calprotectin, fecal lactoferrin, and guaiac-based fecal occult blood test in a diverse group of consecutive patients with acute diarrhea in which routine bacterial stool cultures and cytotoxins for Clostridium difficile were performed. METHODS This was a prospective case-control multicenter study from January 2004 until October 2007 in 2383 consecutive patients with acute diarrhea. They provided stool samples for performing cultures. Patients with positive cultures and an equal number of matched controls with negative cultures underwent fecal occult blood test and calprotectin and lactoferrin assays. RESULTS Calprotectin, lactoferrin, and fecal occult blood tests demonstrated sensitivity and specificity of 83% and 87%, 78% and 54%, and 38% and 85%, respectively, for diagnosing acute bacterial diarrhea. CONCLUSIONS Calprotectin showed high correlation with bacteriologically positive infectious diarrhea compared with lactoferrin and fecal occult blood test. It may potentially revolutionize management algorithm for patients with acute diarrhea. As a screening test, calprotectin can generate results within hours to support presumptive diagnosis of infectious diarrhea, which can decide suitability of stool samples for culture.

Prospective multicenter evaluation of fecal tumor pyruvate kinase type M2 (M2-PK) as a screening biomarker for colorectal neoplasia†‡

Proliferating cells, particularly the tumor cells, express a dimeric isoenzyme of pyruvate kinase, termed M2‐PK. Its a direct target of several oncoproteins; the determination of fecal tumor pyruvate kinase type M2 (M2‐PK) might be another promising tool for colorectal cancer (CRC) screening. In this study, we have evaluated fecal M2‐PK as a screening biomarker for colorectal neoplasia. It was compared against fecal occult blood (FOB) and colonoscopy. Three hundred and seventeen consecutive subjects from 4 different centers were included. Stool specimens were collected before purgation, processed appropriately and were tested for FOB and quantitatively analyzed for M2‐PK. Colonoscopies were performed by experienced endoscopists who were unaware of fecal assay results. At cutoff value of 4 U/ml, fecal M2‐PK assay had a sensitivity, specificity, PPV and NPV of 81.1, 86.7, 71.1 and 61.9% respectively for diagnosing CRC whereas FOBT showed a sensitivity of 36.5%, specificity of 92.2%, PPV of 72.9% and NPV of 71.5% for CRC. Such low specificity of fecal M2‐PK will lead to unacceptably high number of false positives if it is used for mass CRC screening, leading to unindicated colonoscopies with its associated inconveniences, risks and costs. CRC screening test must have high specificity; a high sensitivity is not as vital. To conclude, M2‐PK was found to be a poor screening biomarker for CR neoplasia in a subject population at above average risk based on its prospective comparison with colonoscopy. These marginal performance characteristics do not permit its use as a screening tool for CR neoplasia in present clinical settings.

PPARγ is involved in mesalazine-mediated induction of apoptosis and inhibition of cell growth in colon cancer cells

PURPOSE Mesalazine has been identified as a candidate chemopreventive agent in colon cancer prophylaxis because of its pro-apoptotic and anti-proliferative effects. However, the precise mechanisms of action are not entirely understood. The aim of our study was to investigate the involvement of peroxisome proliferator-activated receptor gamma (PPARgamma) in mesalazines anticarcinogenic actions in colorectal cancer cells. EXPERIMENTAL DESIGN The effects of mesalazine on cell cycle distribution, cell count, proliferation and caspase-mediated apoptosis were examined in Caco-2, HT-29 and HCT-116 cells used as wild-type, dominant-negative PPARgamma mutant and empty vector cultures. We focused on caspase-3 activity, cleavage of poly(ADP-ribose) polymerase (PARP), caspase-8 and caspase-9, as well as on expression of survivin, X-linked inhibitor of apoptosis (Xiap), phosphatase and tensin homolog deleted from chromosome ten (PTEN) and c-Myc. Techniques employed included transfection assays, immunoblotting, flow cytometry analysis, colorimetric and fluorometric assays. RESULTS Mesalazine caused a time- and dose-dependent decrease in both cell growth and proliferation. Growth inhibition was accompanied by a G1/G0 arrest, a significant increase in PTEN, caspase-3 activity, cleavage of PARP and caspase-8, whereas the expressions of Xiap, survivin and c-Myc were decreased simultaneously. Cleavage of caspase-9 was not observed. Moreover, PPARgamma expression and activity were elevated. The growth-inhibitory effect of mesalazine was partially reduced in dominant-negative PPARgamma mutant cells, whereas the expression of c-Myc was not affected. Mesalazine-mediated increased caspase-3 activity, the expression of PTEN, cleavage of PARP and caspase-8 as well as reduced levels of survivin and Xiap were completely abolished in the PPARgamma mutant cell lines. CONCLUSION This study clearly demonstrates that mesalazine-mediated pro-apoptotic and anti-proliferative actions are regulated via PPARgamma-dependent and -independent pathways in colonocytes.

Comparison of an established simple office-based immunological FOBT with fecal tumor pyruvate kinase type M2 (M2-PK) for colorectal cancer screening: prospective multicenter study.

OBJECTIVES:The immunological fecal occult blood test (IFOBT) has established itself as a more precise marker for colorectal cancer (CRC) screening than traditional guaiac-based FOBT. The simpler, cheaper, and more convenient newer office-based IFOBTs have been validated for diagnosing CRC. Dimeric isoenzyme of pyruvate kinase, M2-PK, expressed by tumor cells, has as well been proposed as a screening tool for CRC. This is the first study comparing fecal M2-PK as a screening biomarker for CRC against previously evaluated office-based IFOBT and colonoscopy.METHODS:Six hundred forty consecutive subjects (symptomatic, as well as for CRC screening) referred for colonoscopy for various indications across five centers in Germany provided the stool samples for performing M2-PK and an immunochemical FOB strip test. The IFOBT used was a rapid immunochromatographic assay for detection of fecal hemoglobin. For M2-PK, a commercially available sandwich enzyme-linked immunosorbent assay (ELISA) was used. The M2-PK test needs 6 h, while the office-based test can be read in just 10 min and is five times cheaper.RESULTS:Office-based IFOBT had sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and positive and negative likelihood ratios (LR) of 64.5, 96.3, 72.0, 94.9, 17.5, and 0.4 for diagnosing colorectal neoplasia (CRN), while the above performance characteristics for M2-PK at a cutoff value of 4U/mL were 72.4, 73.8, 29.0, 94.8, 2.8, and 0.8 respectively.CONCLUSIONS:This office-based IFOBT was found to have significantly higher specificity, PPV, and positive LR as compared with M2-PK. IFOBT proved to be a convenient, noncumbersome, quick, and cheap tool in patients with above-average risk for detection of CRN.

Comparative evaluation of a new bedside faecal occult blood test in a prospective multicentre study

Faecal occult blood testing is an established method of colorectal neoplasia screening. Guaiac‐based tests are limited by poor patient compliance, low sensitivity, specificity and positive predictive value. Newer immunochemical‐based tests, accurate but tedious, require a well‐established laboratory set up. There is need for simpler immunochemical tests that can be performed at the out‐patient clinic.

Autologous blood as a submucosal fluid cushion for endoscopic mucosal therapies: Results of an ex vivo study

Objective. Submucosal injection of fluid is used to elevate lesions in order to prevent perforation, which is the most calamitous complication during endoscopic resection therapies. There are several injection options when performing mucosal elevation (normal saline (NS), sodium hyaluronate (SH), etc.). Submucosal injection of fresh, autologous blood offers some advantages because of its specific properties: corpuscular components ensure prolonged elevation and procoagulatory constituents prevent post-interventional bleeding. The purpose of this study was to compare the ex vivo performance of autologous blood as a submucosal fluid cushion (SFC) with that of NS, SH and DW (dextrose water). Material and methods. The proximal third of a resected porcine stomach was cut into squares. One millilitre NS, DW, SH and fresh porcine blood was injected into the submucosa. The height and duration of the submucosal injections were objectively measured during 1 h. Mucosal elevations were resected using an electro snare. Results. The initial height and width of the mucosal elevations were comparable for SH and blood, and significantly higher compared with NS and DW. Mucosal elevation after injecting autologous blood persisted significantly longer compared with NS (p<0.05), but did not differ from hyaluronate. Histopathological examination of the resected specimen confirmed the appropriate submucosal injection of these substances. Conclusions. Submucosal injection of autologous blood with a standard endoscopic injection needle is possible and generates adequate mucosal elevation for the resection of high-quality specimens. This procedure could offer a “gratis” option for SFC as opposed to the expensive SH. Further clinical studies are needed to substantiate its use.

Endoscopic feeding tube placement in patients with cancer: a prospective clinical audit of 2055 procedures in 1866 patients.

Background  Feeding tube placement in patients with aero‐digestive cancer is challenging because of the distortion and/or obstruction of the upper digestive passage. As a result, many patients may receive intravenous fluids and parenteral nutrition instead of enteral feeds.