Glycemic control and BMI changes after endoscopic implantation of a duodenojejunal bypass liner compared with laparoscopic Roux-en-Y gastric bypass surgery: a propensity score matching analysis.

INTRODUCTION: Both laparoscopic Roux-en-Y gastric bypass (RYGB) and duodenojejunal bypass liner (DJBL) have been shown to induce weight loss and dramatically ameliorate type 2 diabetes mellitus (T2DM). Since DJBL implantation causes nutrients to pass through the duodenum without contact with the digestive juices and the duodenal mucosa, its mechanisms have been suggested to mimic those of RYGB. This study aimed to compare the outcomes of these two bariatric procedures in terms of glycemic control and BMI in patients with obesity and T2DM. RESEARCH DESIGN AND METHODS: A retrospective observational cohort propensity score-weighted comparison of laparoscopic Roux-en-Y gastric bypass (RYGB) vs duodenojejunal bypass liner (DJBL) was conducted in patients with obesity and T2DM undergoing either procedure from 05/2014 to 12/2017. Propensity scores were weighted for body weight, body mass index (BMI), and glycated hemoglobin A1c (HbA1c). The primary outcome was comparative improvement of HbA1c. Secondary comparative effectiveness outcomes were decrease of body weight and BMI. RESULTS: Forty-six patients were included: 21 (10 male, 11 female; mean age 50.6 ± 11.7 years) underwent RYGB, while DJBL was implanted in 25 (10 male, 15 female; 52.5 ± 9.5 years). After twelve months, mean ΔBMI was 11.54 ± 4.47 kg/m2 for RYGB vs. 6.23 ± 2.36 kg/m2 for DJBL (p < 0.05). Mean total weight loss was 27.93 ± 8.57% for RYGB vs. 15.04 ± 5.73% for DJBL (p < 0.05). Glycemic control after one year improved significantly in both groups but did not differ significantly. CONCLUSION: RYGB and DJBL seem to be associated with similar remission rates of hyperglycemia after one year. However, RYGB induces more significant weight loss than DJBL.

Relevance of Biotin Deficiency in Patients with Inflammatory Bowel Disease and Utility of Serum 3 Hydroxyisovaleryl Carnitine as a Practical Everyday Marker.

BACKGROUND: Biotin, a water-soluble B vitamin, has demonstrable anti-inflammatory properties. A biotin-deficient diet induced a colitis-like phenotype in mice, alleviable by biotin substitution. Mice with dextran sulfate sodium (DSS)-induced colitis showed biotin deficiency and diminished levels of sodium-dependent multivitamin transporter, a protein involved in biotin absorption. Biotin substitution induced remission by reducing activation of NF-κB, a transcription factor involved in intestinal permeability and inflammatory bowel disease (IBD). We investigated for the first time a possible clinical role of biotin status in IBD. METHODS: In a comparative, retrospective, cross-sectional study, serum samples of 138 patients with IBD (67 female; 72 Crohn's disease (CD), 66 ulcerative colitis (UC)) aged 18-65 years and with a mean age (±SD) of 42.5 ± 14.3 years as well as 80 healthy blood donors (40 female; 40.0 ± 10.0 years; range 20-60 years) were analyzed. Inflammation was defined as hsCRP ≥5 mg/L, and to determine biotin status, serum 3-hydroxyisovaleryl carnitine (3HIVc) levels were measured by LC-MS/MS. RESULTS: A total of 138 patients with IBD (67f; 72CD/66 UC; 42.5 ± 14.3 years) were enrolled: 83/138 had inflammation. Mean serum 3HIVc levels were significantly higher in IBD patients but unaffected by inflammation. Biotin deficiency (95th percentile of controls: >30 nmol/L 3HIVc) was significantly more common in IBD patients versus controls. CONCLUSION: High serum 3HIVc levels and biotin deficiency were associated with IBD but not inflammatory activity or disease type. Our findings suggest biotin may play a role as cause or effect in IBD pathogenesis. Routine assessment and supplementation of biotin may ameliorate IBD and support intestinal integrity.

Chronic intestinal failure and short bowel syndrome in Crohn's disease.

Chronic intestinal failure (CIF) is a rare but feared complication of Crohn's disease. Depending on the remaining length of the small intestine, the affected intestinal segment, and the residual bowel function, CIF can result in a wide spectrum of symptoms, from single micronutrient malabsorption to complete intestinal failure. Management of CIF has improved significantly in recent years. Advances in home-based parenteral nutrition, in particular, have translated into increased survival and improved quality of life. Nevertheless, 60% of patients are permanently reliant on parenteral nutrition. Encouraging results with new drugs such as teduglutide have added a new dimension to CIF therapy. The outcomes of patients with CIF could be greatly improved by more effective prevention, understanding, and treatment. In complex cases, the care of patients with CIF requires a multidisciplinary approach involving not only physicians but also dietitians and nurses to provide optimal intestinal rehabilitation, nutritional support, and an improved quality of life. Here, we summarize current literature on CIF and short bowel syndrome, encompassing epidemiology, pathophysiology, and advances in surgical and medical management, and elucidate advances in the understanding and therapy of CIF-related complications such as catheter-related bloodstream infections and intestinal failure-associated liver disease.

A novel, stiff-shaft, flexible-tip guidewire for cannulation of biliary stricture during endoscopic retrograde cholangiopancreatography: a randomized trial.

BACKGROUND AND STUDY AIMS: During endoscopic retrograde cholangiopancreatography (ERCP), a guidewire is used to cannulate biliary strictures and allow for therapeutic interventions. The aim of this study was to assess the success of stricture cannulation using a combination of a flexible guidewire and a stable nitinol wire vs. a novel, single, stiff-shaft, flexible-tip guidewire. PATIENTS AND METHODS: Consecutive patients who were scheduled for ERCP for biliary obstruction were randomized to undergo the procedure with either a 260-cm long, angled-tip hydrophilic wire in combination with a nitinol wire as required (standard group), or a novel, 270-cm guidewire featuring a hyperflexible, hydrophilic tip with a stiff shaft (novel group). At unsuccessful negotiation of the stricture, patients in the standard group were switched to the novel guidewire and vice versa ("crossover"). Successful cannulation (primary success: as assigned; final success: after "crossover"), procedure time, and total number of wires needed per procedure were compared. RESULTS: A total of 222 patients were randomized and 197 were included in the study (97 in the standard group and 100 in the novel group). The primary success rate was significantly higher in the novel group (94/100, 94 %) compared with the standard group (77/97, 79 %; P = 0.00041), and final success was similar. Mean time (median, interquartile range) to stricture cannulation was 11.2 minutes (6.3, 3.7 - 14.6) in the standard group and 8.1 minutes (2.5, 0.9 - 7.7) in the novel group (P < 0.0001). The mean total procedure time was 31.2 minutes (24.6, 16.5 - 40.8) vs. 24.3 minutes (16.9, 10.0 - 31.5), respectively (P = 0.0011). There were no complications observed with either of the guidewires. CONCLUSIONS: A guidewire that features a flexible tip with a stable shaft could replace the use of a combination of flexible and stable guidewires and increase the success rate of stricture cannulation while decreasing the procedure time.ClinicalTrials.gov Identifier: NCT 01382680.

Prevalence of anemia in inflammatory bowel diseases in european countries: a systematic review and individual patient data meta-analysis.

BACKGROUND: The main objective is to determine the overall prevalence of anemia in inflammatory bowel diseases (IBD) in Europe. METHODS: A systematic literature search in PubMed and Embase was performed for studies published between January 2007 and May 2012. Eligible studies were included if they were original full-paper publications originated from Europe and if the authors agreed to provide their data. An overall prevalence of anemia in IBD, disease specific, and age-gender stratified basis prevalences were estimated. The influence of disease entity (Crohn's disease/ulcerative colitis), gender, age, disease activity (remission/active disease), and IBD-specific treatment strategies on the prevalence of anemia was analyzed by a mixed logistic regression model. Thereby, the factor country of origin was included as a random effect. RESULTS: Data were available for 2192 patients, mainly treated in tertiary referral centers. The overall prevalence of anemia in IBD patients was 24% (95% confidence interval, 18-31). Age-gender stratified prevalences were estimated for the age strata 18 to 29, 30 to 39, 40 to 49, 50 to 64, 65 to 74, >74 years and ranged from 18% to 35%. Patients receiving IBD-specific medication (P = 0.0002, odds ratio 1.54), and patients with active disease status (P < 0.0001, odds ratio 2.72) were significantly more likely to have anemia compared with patients not receiving IBD-specific medication or being in remission. Patients with ulcerative colitis tended to have anemia less likely than patients with Crohn's disease (P = 0.01, odds ratio 0.77). CONCLUSIONS: The overall prevalence of anemia in patients with Crohn's disease was 27% (95% confidence interval, 19-35) and 21% (95% confidence interval, 15-27) in patients with ulcerative colitis. Thereby, 57% of the anemic patients were iron deficient.

Sources of information and factual knowledge in Europeans with inflammatory bowel diseases: a cross-cultural comparison between German and Irish patients.

BACKGROUND: Disease related knowledge may be associated with quality of life, coping skills and medication adherence. However, little is known of cross-cultural variations regarding inflammatory bowel disease knowledge or sources of information and no study has assessed knowledge in diverse European IBD populations. AIM: To assess sources of information and patient knowledge in Irish and German inflammatory bowel disease patients. METHODS: Three hundred and three disease, gender, age and education matched German and Irish patients completed a previously validated knowledge questionnaire. Additional data were collected on age, gender, education, disease type and duration, family history, smoking habits, medication use, previous surgery and quality of life. RESULTS: German patients obtained knowledge from a wider range of sources than Irish patients (p<0.001), most notably from the internet (p<0.001), newspapers and magazines (p=0.002). Both cohorts answered a similar number of questions correctly (Irish, mean 4.4 questions (Standard deviation (S.D.) 2.4); German, mean 4.3 (S.D. 2.2); p=0.67). In addition, both nationalities answered "don't know" to a similar number of questions (Irish, mean 3.3 (S.D. 3.1); German, mean 2.7 (S.D. 2.8); p=0.12) while Irish patients answered slightly fewer questions wrongly (Irish, mean 2.4 (S.D. 1.8); German, mean 3.1 (S.D. 1.9); p=0.002). A multivariate analysis included only Crohn's disease, female gender, young age and higher educational status as being significantly and independently associated with knowledge. CONCLUSIONS: Our data suggest few differences between German and Irish IBD patients, despite cultural and linguistic differences, with regard to disease related knowledge of IBD.

Prevalence of colorectal cancer and its precursor lesions in symptomatic and asymptomatic patients undergoing total colonoscopy: results of a large prospective, multicenter, controlled endoscopy study.

BACKGROUND: Colorectal cancer (CRC) is the second most common cancer in Germany. Screening colonoscopies have been offered in Germany since 2002. However, validation of screening programs for CRC relies on estimates up to date. OBJECTIVE: The aim of this study was to analyze the influence of the risk factor tumor-suspicious symptoms on the prevalence of CRC and its precursor lesions in patients at least 55 years of age undergoing colonoscopy in comparison with an age-matched and sex-matched control population undergoing screening colonoscopy. DESIGN: Multicenter, prospective, controlled colonoscopy study. SETTING: Integrated care program of 49 gastroenterological practices in collaboration with a health insurance company and the screening colonoscopy program in Hesse, Germany. PATIENTS: In total, 1075 symptomatic and 5375 asymptomatic participants were matched for age and sex (1 : 5) from 1 October 2008 to 30 September 2010. MAIN OUTCOME MEASUREMENTS: Detection of CRC and its precursor lesions. RESULTS: Overall, the prevalence of CRC was significantly equivalent in both the symptomatic (n=13/1075, 1.21%) and the control group [n=55/5375, 1.02%, 95% confidence interval (CI) for the difference: [-0.46%, 0.83%], P=0.0002, equivalence test with δ=1.5%], respectively. Advanced adenomas were observed in significantly fewer symptomatic patients (61/1075, 5.67%) compared with 432/5375 matched asymptomatic screening participants (8.03%, 95% CI for the difference: [-3.98%, -0.74%], P=0.0094, difference test). Finally, polyps were found significantly less often in symptomatic patients (n=269/1075, 25.0%) than in matched screening participants (n=1807/5375, 33.6%, 95% CI for the difference: [-11.53%, -5.66%], P<0.0001, difference test). CONCLUSION: The results underline the importance of screening the symptom-free population at least 55 years of age to prevent CRC.

Increased levels of anti-glycan antibodies in patients with cystic fibrosis.

BACKGROUND: The prevalence of Crohn's disease (CD) is increased in patients with cystic fibrosis (CF). Anti-Saccharomyces cerevisiae antibodies (ASCA) have been suggested as a screening tool to detect CD in CF. Recently, several new anti-glycan antibodies have been reported in CD. - MATERIALS AND METHODS: The sera of 119 CF patients of various age groups were prospectively screened for ASCA type IgG (gASCA), anti-laminaribioside carbohydrate IgG antibodies (ALCA), anti-chitobioside carbohydrate IgA antibodies (ACCA), and anti-mannobioside carbohydrate IgG antibodies (AMCA). The frequency of these anti-glycan antibodies was then compared in patients with CD, ulcerative colitis, rheumatoid arthritis and healthy volunteers. - RESULTS: A significant number of CF patients were positive for gASCA (51.3% (41.6-60.6)) and up to three other anti-glycan antibodies concurrently. Serum levels of anti-glycan antibodies in CF and CD were not related to parameters of inflammation. Despite the well-documented difference in clinical course between male and female CF patients no gender difference of anti-glycan antibodies was found. In contrast, there was a significant positive correlation between anti-glycan markers and age in CF patients. - CONCLUSIONS: Our findings demonstrate for the first time the increased frequency of a panel of anti-glycan antibodies in CF and provide a link between the presence of these serological biomarkers and patient's age. Anti-glycan antibody profiling may therefore become a valuable tool in the care of patients with CF.

Methotrexate for maintenance of remission in chronic active Crohn's disease: long-term single-center experience and meta-analysis of observational studies.

BACKGROUND: According to current guidelines methotrexate (MTX) should be considered as a second-line immunomodulator in patients with chronic active Crohn's disease (CD) if purine analogs are not tolerated or there is a lack of efficacy. However, its therapeutic role remains controversial to the present day. METHODS: Medical records of all eligible patients treated in the outpatient clinic of the Johann Wolfgang Goethe-University Hospital between December 2000 and January 2009 were reviewed. RESULTS: Sixty-three patients were identified. The mean duration of treatment was 100 weeks (range, 2-364 weeks) with a mean cumulative dose of MTX of 2130 mg (range, 40-9005 mg). In 50 (79%) patients started on MTX clinical remission could be achieved within 3 months of treatment. The cumulative probability of these patients to maintain remission was 95.3%, 89.5%, 70.6%, and 62.8% at 6 months, 1, 2, and 3 years of treatment, respectively. The respective figures of the meta-analysis were 94%, 86%, 75%, 53%, and 43. Drug-related side effects were reported in 50 patients (79%), leading to withdrawal of MTX in 21 cases (33%). CONCLUSIONS: Along with previous observations our data demonstrate the efficacy of MTX as a second-line immunomodulator in chronic active CD. However, its use is limited due to intolerable side effects in a large proportion of patients. The results should encourage further research in order to establish the definite significance of MTX in chronic active CD.

PPARgamma 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 mesalazine's 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.

The dietary histone deacetylase inhibitor sulforaphane induces human beta-defensin-2 in intestinal epithelial cells.

Antimicrobial peptides like human beta-defensin-2 (HBD-2) play an important role in the innate immune system protecting the intestinal mucosa against bacterial invasion. The dietary histone deacetylase (HDAC) inhibitors sulforaphane (SFN) and butyrate have received a great deal of attention because of their ability to simultaneously modulate multiple cellular targets involved in cellular protection. In this study the influence of SFN and butyrate on HBD-2 expression as well as the molecular pathways involved in SFN-mediated induction of HBD-2 were scrutinized. Treatment of Caco-2, HT-29 and SW480 cells with SFN led to a time- and dose-dependent upregulation of HBD-2 mRNA expression as determined by semi-quantitative reverse transcription-polymerase chain reaction. Moreover, HBD-2 protein production increased in response to SFN, measured by enzyme-linked immunosorbent assay. Induction of HBD-2 was also observed in response to butyrate. Immunofluorescence analysis revealed that the protein was localized in the cytosol. Coincubation of SFN with a vitamin D receptor (VDR), or an extracellular-regulated kinase 1/2 or a nuclear factor-kappaB inhibitor all reduced HBD-2 mRNA upregulation. In contrast, transfection of cells with a dominant-negative peroxisome proliferator-activated receptor gamma (PPARgamma) mutant vector to inhibit PPARgamma wild-type action and inhibition of p38 mitogen-activated protein kinase (MAPK) signalling did not affect SFN-mediated upregulation of HBD-2 mRNA. Moreover, SFN induced the expression of VDR, PPARgamma and phosphorylated ERK1/2 but did not affect p38 MAPK activation. The data clearly demonstrate for the first time that the dietary HDAC inhibitor SFN is able to induce antimicrobial peptides in colonocytes. In this process HBD-2 expression is regulated via VDR, mitogen-activated protein kinase kinase/extracellular-regulated kinase and nuclear factor-kappaB signalling.

Involvement of different nuclear hormone receptors in butyrate-mediated inhibition of inducible NF kappa B signalling.

BACKGROUND: NF kappa B plays a major role in the control of immune responses and inflammation. Recently, butyrate has not only been demonstrated to suppress NF kappa B activation in colorectal cancer cells, but also to modulate the activity and expression of the Peroxisome-Proliferator-Activated-Receptor gamma (PPAR gamma) and the vitamin D receptor (VDR). Therefore, we investigated a putative involvement of both receptors in butyrate-mediated inhibition of inducible NF kappa B signalling. RESULTS: Treatment of HT-29 cells with butyrate attenuated basal p50 as well as TNFalpha- and LPS-induced p50 and p65 NF kappa B dimer activity in the nucleus as measured by transcription factor assay. Cytosolic expression of I kappa B alpha protein was reduced by butyrate, and TNFalpha but not by LPS. Challenge of cells with the VDR antagonist ZK191732 up-regulated basal NF kappa B activity by decreasing I kappa B alpha simultaneously, while basal signalling was not influenced by the PPAR gamma inhibitor GW9662. Pre-treatment with ZK191732 reduced the inhibitory effect of butyrate on NF kappa B activation caused by TNFalpha whereas no activation was noted in transfected dominant-negative PPAR gamma mutant vector cells. Adversely, the inhibitory effect of butyrate on NF kappa B activity induced by LPS was almost reversed in dominant-negative PPAR gamma mutant cells while pre-incubation of ZK191732 did not affect butyrate-mediated attenuation of LPS-induced NF kappa B signalling. CONCLUSION: These findings provide evidence for the involvement of the nuclear hormone receptors PPAR gamma and VDR in butyrate-mediated inhibition of inducible NF kappa B activation dependent on the stimulated signalling pathway. Moreover, VDR appears to play an inhibitory role in the regulation of basal NF kappa B signalling.

The TGFbeta/Smad 3-signaling pathway is involved in butyrate-mediated vitamin D receptor (VDR)-expression.

Previously, we demonstrated the pivotal role of the vitamin D receptor (VDR) in mediating the butyrate-induced differentiation in colon cancer cells. Smad 3, a downstream component of transforming growth factor-beta (TGFbeta) signaling, has been shown to act as a coactivator of VDR and to possibly regulate the vitamin D signaling pathway. In this study, we demonstrate a distinct impact of the TGFbeta/Smad 3-signaling pathway in the butyrate-mediated VDR expression and induction of differentiation. Butyrate treatment resulted in a significant induction of the phosphorylation level of Smad 3, while the combination of butyrate and a specific TGFbeta1-antibody or a TGFbeta-receptor inhibitor considerably diminished the butyrate-induced upregulation of VDR expression. Using a specific inhibitor, we were also able to demonstrate an involvement of the p38 MAPK in the increase of Smad 3 phosphorylation following butyrate treatment, thus opening the view to further elucidate possible mechanisms mediating the upregulation of VDR expression following butyrate treatment in colon cancer cells.

Role of nuclear hormone receptors in butyrate-mediated up-regulation of the antimicrobial peptide cathelicidin in epithelial colorectal cells.

BACKGROUND AND AIMS: The human cathelicidin (LL-37) is one of the major antimicrobial peptides of the non-specific innate immune system in the intestinal tract. Altered expression has been associated with gastrointestinal disease. Recent studies demonstrated that butyrate induces LL-37 mRNA in colonic epithelial cells, however the underlying molecular mechanisms have not been elucidated. The objective of this study was to investigate the regulatory pathways involved in butyrate-induced up-regulation of LL-37. METHODS AND RESULTS: Treatment of Caco-2 and HT-29 cells with butyrate led to a time-dependent up-regulation of LL-37 mRNA expression as determined by semi-quantitative RT-PCR. Up-regulation of LL-37 mRNA by butyrate was subsequently followed by an increase in LL-37 protein expression as observed by immunofluorescence. Co-incubation of butyrate with a VDR, p38 MAPK, ERK 1/2 and TGF-beta1 receptor kinase inhibitor all reduced butyrate-mediated LL-37 mRNA up-regulation. In contrast, transfection of Caco-2 cells with a dominant-negative PPARgamma mutant vector did not affect butyrate-mediated up-regulation of LL-37 mRNA. CONCLUSION: Our results clearly demonstrate that butyrate-mediated up-regulation of LL-37 is influenced by several signalling pathways and receptors including MAPKs as well as VDR and TGF-beta1, but not by PPARgamma. These data may provide new opportunities in the treatment of gastrointestinal diseases.

PPARgamma is a key target of butyrate-induced caspase-3 activation in the colorectal cancer cell line Caco-2.

BACKGROUND: Butyrate, a potent histone deacetylase inhibitor, belongs to a promising new class of antineoplastic agents with the capacity to induce apoptosis of cancer cells. However, the underlying mechanisms of action have yet not been elucidated. AIM: To further investigate the molecular events involved in butyrate-induced caspase-3 activation in Caco-2 wild-type, empty-vector and dominant-negative PPARgamma mutant cells along the signalling pathway. In this context, the involvement and up-regulation of PPARgamma was examined. RESULTS: Stimulation of cells with butyrate resulted in increased expression of PPARgamma mRNA, protein, and activity as well as phospho-p38 MAPK protein expression and caspase-3 activity. Arsenite, a direct stimulator of p38 MAPK, also led to an increased PPARgamma expression, thereby mimicking the effects of butyrate. In contrast, butyrate-mediated up-regulation of PPARgamma was counteracted by co-incubation with the p38 MAPK inhibitor SB203580. Treatment of cells with butyrate resulted in both increased caspase-8 and -9 activity and reduced expression of XIAP and survivin. However, butyrate-mediated effects on these apoptosis-regulatory proteins leading to caspase-3 activation were almost completely abolished in Caco-2 dominant-negative PPARgamma mutant cells. CONCLUSIONS: Our data clearly unveil PPARgamma as a key target in the butyrate-induced signalling cascade leading to apoptosis via caspase-3 in Caco-2 cells.

Differential induction of BLT receptor expression on human endothelial cells by lipopolysaccharide, cytokines, and leukotriene B4.

Leukotriene (LT) B4 is a powerful chemotactic and immune modulating agent that signals via two receptors denoted BLT1 and BLT2. Here we report that BLT1 and BLT2 are expressed at low levels in an apparently silent state in human umbilical vein endothelial cells (HUVEC). However, treatment with LPS leads to a >10 fold increase in the levels of BLT1 mRNA without any significant effects on BLT2 mRNA. In parallel, LPS also increases the amounts of BLT1 protein. Tumor necrosis factor-alpha (TNF-alpha) increases the expression of BLT2 mRNA approximately 6 times above basal levels with only a modest increase in BLT1 mRNA. Interleukin-1beta causes variable and parallel increases of both BLT1 and BLT2 mRNA. The natural ligand LTB4 also increases BLT1, but not BLT2, mRNA and protein expression. Along with the induction of BLT1 and/or BLT2, HUVEC acquire the capacity to respond to LTB4 with increased levels of intracellular calcium and these signals can be blocked by isotype selective BLT antagonists, CP-105696 and LY-255283. In addition, treatment of HUVEC with LTB4 causes increased release of both nitrite, presumably reflecting nitric oxide (NO), and monocyte chemoattractant protein-1. Our data indicate that expression of functional BLT receptors may occur at the surface of endothelial cells in response to LPS, cytokines, and ligand, which in turn may have functional consequences during the early vascular responses to inflammation. Moreover, the results point to BLT receptors as potential targets for pharmacological intervention in LT-dependent inflammatory diseases such as asthma, rheumatoid arthritis, and arteriosclerosis.

15-deoxy-Delta12,14-prostaglandin J2 inhibits the expression of microsomal prostaglandin E synthase type 2 in colon cancer cells.

Prostaglandin (PG) E(2) (PGE(2)) plays a predominant role in promoting colorectal carcinogenesis. The biosynthesis of PGE(2) is accomplished by conversion of the cyclooxygenase (COX) product PGH(2) by several terminal prostaglandin E synthases (PGES). Among the known PGES isoforms, microsomal PGES type 1 (mPGES-1) and type 2 (mPGES-2) were found to be overexpressed in colorectal cancer (CRC); however, the role and regulation of these enzymes in this malignancy are not yet fully understood. Here, we report that the cyclopentenone prostaglandins (CyPGs) 15-deoxy-Delta(12,14)-PGJ(2) and PGA(2) downregulate mPGES-2 expression in the colorectal carcinoma cell lines Caco-2 and HCT 116 without affecting the expression of any other PGES or COX. Inhibition of mPGES-2 was subsequently followed by decreased microsomal PGES activity. These effects were mediated via modulation of the cellular thiol-disulfide redox status but did not involve activation of the peroxisome proliferator-activated receptor gamma or PGD(2) receptors. CyPGs had antiproliferative properties in vitro; however, this biological activity could not be directly attributed to decreased PGES activity because it could not be reversed by adding PGE(2). Our data suggest that there is a feedback mechanism between PGE(2) and CyPGs that implicates mPGES-2 as a new potential target for pharmacological intervention in CRC.

Combining infliximab with methotrexate for the induction and maintenance of remission in refractory Crohn's disease: a controlled pilot study.

OBJECTIVES: Immunosuppression of chronic active Crohn's disease resistant or intolerant to purine antimetabolites still remains a clinical challenge. To obtain long-lasting effects with the anti-TNF-alpha antibody infliximab repeated infusions are often required. Methotrexate has been shown to be a moderately effective drug in maintaining remission in Crohn's disease. The aim of the present pilot study was to evaluate the combination of infliximab and methotrexate as therapy for refractory Crohn's disease. METHODS: Nineteen patients with chronic active Crohn's disease resistant or intolerant to azathioprine were enrolled. Patients received either two infusions of infliximab (5 mg/kg) alone (n=8) or in combination with long-term methotrexate at a dosage of 20 mg/week (n=11) over 48 weeks. RESULTS: Two out of eight patients receiving infliximab monotherapy and four out of 11 patients treated with infliximab and concomitant methotrexate had discontinued study treatment by week 48, solely because of lack of efficacy. Clinical remission at week 48 was observed in five out of seven patients treated with infliximab and methotrexate, but only in two out of six patients receiving infliximab monotherapy. In addition, patients treated with concomitant methotrexate achieved remission earlier (median time 2 versus 18 weeks) and needed fewer steroids (median prednisolone dose 0 versus 11.8 mg). Despite an increased mean number of adverse events per patient in the methotrexate group, the proportions of patients experiencing any adverse events and serious adverse events were similar across treatment groups. CONCLUSIONS: The combination of infliximab with long-term methotrexate may be a promising concept in refractory Crohn's disease. Our data prompt larger trials.