PubMed Health⌕ Search

Biomedical subjects

Thomas Fiedler

Publications and source records attributed to Thomas Fiedler.

5 recordsLinked to original sources

jPREdictor: a versatile tool for the prediction of cis-regulatory elements.

Gene regulation is the process through which an organism effects spatial and temporal differences in gene expression levels. Knowledge of cis-regulatory elements as key players in gene regulation is indispensable for the understanding of the latter and of the development of organisms. Here we present the tool jPREdictor for the fast and versatile prediction of cis-regulatory elements on a genome-wide scale. The prediction is based on clusters of individual motifs and any combination of these into multi-motifs with selectable minimal and maximal distances. Individual motifs can be of heterogenous classes, such as simple sequence motifs or position-specific scoring matrices. Cluster scores are weighted occurrences of multi-motifs, where the weights are derived from positive and negative training sets. We illustrate the flexibility of the jPREdictor with a new predic-tion of Polycomb/Trithorax Response Elements in Drosophila melanogaster. jPREdictor is available as a graphical user interface for online use and for download at http://bibiserv.techfak.uni-bielefeld.de/jpredictor.

Animals↗

DLG5 variants in inflammatory bowel disease.

OBJECTIVES: Genetic variants within DLG5 were recently reported to be associated with inflammatory bowel disease (IBD). The aim of our study was to test for allelic and haplotype associations of six DLG5 variants in 668 IBD patients from two European populations. Furthermore, we evaluated whether DLG5 variants alter gastrointestinal permeability in Crohn's disease (CD). METHODS: Six DLG5 variants (p.R30Q, p.P1371Q, p.G1066G, rs2289308, DLG_e26, p.D1507D) were genotyped in two study populations: (1) German IBD patients (CD n = 250; ulcerative colitis (UC) n = 150) and German healthy controls (n = 422); (2) Hungarian IBD patients (CD n = 144; UC n = 124) and Hungarian healthy controls (n = 205). Subtyping analysis was performed in respect of CARD15 mutations and clinical characteristics. We also tested for differences within DLG5 genotypes in German CD patients with respect to gastroduodenal and intestinal permeability measured by triple-sugar-test. RESULTS: Allele as well as genotype frequencies of DLG5 variants did not differ between IBD patients and controls in either study population. Indeed, the p.R30Q polymorphism was found more frequently in controls than in patients. The distribution of DLG5 genotypes in German and Hungarian CD patients with CARD15 mutations was not different from patients without mutated CARD15. We did also not observe any association between DLG5 variants and clinical parameters. Importantly, DLG5 variants were not associated with gastroduodenal or intestinal permeability. CONCLUSIONS: We could not replicate that DLG5 is a relevant disease susceptibility gene for IBD in German or Hungarian subjects. In addition, we have no evidence that DLG5 variants are involved in altered gastrointestinal permeability in CD.

Adult↗

Introducing genetic testing for adult-type hypolactasia.

BACKGROUND AND AIMS: To evaluate genotyping for two DNA variants (c.1993+327C>T and c.1438+117G>A), recently found to be associated with adult-type hypolactasia, in the diagnosis of lactose intolerance. METHODS: In total, 166 consecutive patients with gastrointestinal symptoms mimicking hypolactasia admitted to the clinic between March 2002 and December 2002 were included. Genotyping for the two DNA variants (c.1993+327C>T and c.1438+117G>A) and standard H2 breath test was performed. RESULTS: Among 116 patients with positive H2 breath test, the c.1993+327C variant was detectable in 106 (91.4%) patients. Among 50 patients with negative H2 breath test, the c.1993+327C variant was seen in 2 patients. Sensitivity, specificity, positive and negative predictive values for the c.1993+327C variant were 91.4, 96.0, 98.1 and 82.8%, respectively. Genotyping for the c.1438+117G variant did not bring any additional information. Among 4 of the 10 patients with positive H2 breath test but negative for the c.1993+327C and the c.1438+117G variant,further evaluation revealed other diseases known to cause secondary hypolactasia such as celiac disease and short bowel syndrome. CONCLUSION: In symptomatic patients, genotyping for the DNA variant c.1993+327C is a reliable test for adult-type hypolactasia with high sensitivity and specificity and thus provides a new tool in the diagnostic workup of hypolactasia.

Blood Glucose↗

Nonresorbable copolymer implantation for gastroesophageal reflux disease: a randomized sham-controlled multicenter trial.

BACKGROUND & AIMS: This aim was to determine whether endoscopic implantation of a biocompatible nonresorbable copolymer (Enteryx; Boston Scientific Corp, Natick, MA) is a more effective therapy for gastroesophageal reflux disease (GERD) than a sham procedure. METHODS: In a randomized, single-blind, prospective, multicenter clinical trial, 64 patients with GERD were enrolled whose symptoms were well controlled by proton pump inhibitor (PPI) therapy and rapidly recurred after cessation of PPI therapy. Thirty-two patients were assigned to Enteryx implantation and 32 to a sham procedure consisting of standard upper endoscopy. Patients in both groups with unsatisfactory symptom relief after 3 months were eligible for re-treatment by Enteryx implantation. The primary study end point was > or =50% reduction in PPI use. Secondary end points included > or =50% improvement in GERD score and the proportion of patients not undergoing re-treatment procedure. Follow-up evaluations were performed at 3 and 6 months. RESULTS: The percentage of Enteryx-treated patients achieving a > or =50% reduction in PPI use (81%) was greater than that of the sham group (53%), with a rate ratio of 1.52 (confidence interval [CI], 1.06-2.28; P=.023). A higher proportion of the Enteryx (68%) than sham group (41%) ceased PPI use completely (rate ratio, 1.67; CI, 1.03-2.80; P=.033). GERD health-related quality of life heartburn score improvement > or =50% was achieved by 67% of the Enteryx group versus 22% of the sham group (rate ratio, 3.05; CI, 1.55-6.33; P <.001). More Enteryx-treated (81%) than sham-treated (19%) patients did not undergo re-treatment (rate ratio, 4.33; CI, 2.23-9.29; P <.001). CONCLUSIONS: Enteryx implantation more effectively reduces PPI dependency and alleviates GERD symptoms than a sham procedure.

Adult↗