Publications by authors named "Stephan Vavricka"

Serum protein electrophoresis is used in clinical practice to identify patients with multiple myeloma and other serum protein disorders. It is an inexpensive and easy-to-perform screening procedure. Electrophoresis separates serum proteins based on their physical properties and identifies morphologic patterns in response to acute and chronic inflammation, various malignancies, liver or renal failure, and hereditary protein disorders.

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Background: The epidemiology of Helicobacter pylori infection reflects the age-characteristics, developmental status and access to health care of the population in a given area.

Aim: To assess the influence of demographic variables on the prevalence of H. pylori status among patients evaluated in a Swiss university medical center.

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Background: Transnasal endoscopy with a small-caliber endoscope has been shown to be helpful for the placement of nasoenteral feeding tubes in patients who are critically ill. Success rates were limited by the short working length of the small-caliber endoscopes.

Objective: To compare the success rate of a 133-cm-long, small-caliber, prototype videoendoscope with a standard 92-cm-long, small-caliber, fiberoptic endoscope for the transnasal placement of feeding tubes.

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Background: Tegaserod is a novel drug for the treatment of constipation-predominant irritable bowel syndrome. Tegaserod is thought to exert its prokinetic effect as a selective partial agonist of serotonin receptor type 4 (5-HT4) receptors located in the enteric nervous system. It is unknown, however, whether tegaserod interacts with the human serotonin reuptake transporter (hSERT) and the uptake transporters for dopamine (hDAT) and norepinephrine (hNET).

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Muramyl peptides derived from bacterial peptidoglycan are detected intracellularly by Nod1 and Nod2, 2 members of the newly characterized nod-like receptor (NLR) family of pattern recognition molecules. In the absence of bacterial invasion into the host cytosolic compartment, it remains unclear whether muramyl peptides can cross the plasma membrane and localize into the cytosol. We have recently demonstrated that the plasma membrane transporter, hPepT1, was able to efficiently translocate muramyl dipeptide (MDP), a specific Nod2-activating molecule, into host cells.

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Background And Aims: There is growing evidence that gastroesophageal reflux disease (GERD) may cause typical laryngeal/pharyngeal lesions secondary to tissue irritation. The prevalence of those lesions in GERD patients is not well established. The aim of this study was to evaluate the prevalence of GERD signs in the laryngopharyngeal area during routine upper gastrointestinal endoscopy.

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Intestinal absorption of drugs, nutrients, and other compounds is mediated by uptake transporters expressed at the apical enterocyte membrane. These compounds are returned to the intestinal lumen or released into portal circulation by intestinal efflux transporters expressed at apical or basolateral membranes, respectively. One important transporter superfamily, multiple members of which are intestinally expressed, are the solute carriers (SLCs).

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Sustained expression of cytoprotective intestinal epithelial heat shock proteins (Hsps), particularly Hsp27, depends on stimuli derived from bacterial flora. In this study, we examined the role of the bacterial chemotactic peptide fMLP in stimulating colonic epithelial Hsp expression at concentrations encountered in a physiological milieu. Treatment of the polarized human intestinal epithelial cell line Caco2bbe with physiological concentrations of fMLP (10-100 nM) induced expression of Hsp27, but not Hsp72, in a time- and concentration-dependent manner.

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A major mechanism for apical peptide absorption by small intestine is via the proton-coupled transporter PepT1. PepT1 is expressed at a high level in proximal small intestine, but it is not expressed in the healthy colon. However, in chronic states of intestinal inflammation, such as in Crohn's disease and ulcerative colitis, PepT1 expression in colonic epithelia is increased, serving as a pathway for entry of bacteria-derived molecules such as muramyl dipeptide (MDP) and fMet-Leu-Phe (fMLP).

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Bile acids are synthesized from cholesterol in the liver and are excreted into bile via the hepatocyte canalicular bile salt export pump. After their passage into the intestine, bile acids are reabsorbed in the ileum by sodium-dependent uptake across the apical membrane of enterocytes. At the basolateral domain of ileal enterocytes, bile acids are extruded into portal blood by the heterodimeric organic solute transporter OSTalpha/OSTbeta.

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Background: The aminosalicylates remain foundation therapy for mild-to-moderate ulcerative colitis. Pro-drug 5-aminosalicylic acid (5-ASA; mesalamine) formulations have been developed to prevent 5-ASA from the proximal absorption and release of mesalamine, to decrease inflammation, and to improve colonic absorption. Clinically, pro-drugs such as olsalazine have been associated with dose-dependent diarrhea, which was likely secondary to ileal secretion induced by the azo linkages, in 17% of patients.

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Purpose: To identify and localize the expression of multispecific organic anion transporting polypeptides (Oatps/OATPs) in the ciliary body epithelium and to investigate their possible involvement in the transport of the antiglaucoma agent unoprostone.

Methods: Oatps/OATPs were detected by immunoblot analysis and by immunofluorescence microscopy in homogenized and fixed rat and human ciliary body samples using specific polyclonal antibodies. Transport of 3H-labelled unoprostone was measured in Oatp/OATP expressing Xenopus laevis oocytes.

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Heat shock proteins (HSP) 25 and 72 are expressed normally by surface colonocytes but not by small intestinal enterocytes. We hypothesized that luminal commensal microflora maintain the observed colonocyte HSP expression. The ability of the small intestine to respond to bacteria and their products and modulate HSPs has not been determined.

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Article Synopsis
  • The study investigates how the intestinal apical transporter hPepT1 facilitates the uptake of muramyl dipeptide (MDP) in intestinal epithelial cells, leading to the activation of the NOD2/CARD15 gene and downstream signaling pathways like NF-kappaB.
  • Experiments with Caco2/bbe cell monolayers showed that increases in hPepT1 expression enhanced MDP uptake and NF-kappaB activation, while silencing hPepT1 reduced these effects, suggesting a direct relationship between hPepT1 and MDP signaling.
  • Findings reveal that MDP uptake by hPepT1 promotes the production of inflammatory markers such as interleukin-8, indicating its
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Background/aims: The organic anion transporting polypeptides (OATPs) mediate the uptake of numerous amphipathic compounds into hepatocytes. Our aim was to study the expression and regulation of OATP8 (OATP1B3, SLC21A8/SLCO1B3) and OATP-C (OATP1B1, SLC21A6/SLCO1B1) in hepatocellular carcinomas (HCC).

Methods: RNA and protein levels in 13 paired HCC and adjacent non-tumor liver samples were quantified by real-time polymerase chain reaction or Western blot, respectively.

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No data exist on the trigger for platelet transfusions in adult thrombocytopenic patients with acute leukemia undergoing lumbar puncture (LP). We reviewed the records of 66 patients with acute leukemia (median age 38 years, range 18-68) who have been treated in our institution for 6 years. A total of 195 LPs were performed.

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Epithelioid hemangioendothelioma (EHE) is a rare low-grade malignant vascular neoplasm with unpredictable prognosis. We report on a patient suffering from a vascular neoplasm with primary manifestation in the skeleton and subsequent development of lesions of EHE in the spleen, liver and lung. Based on the assumption that involvement of visceral organs was due to metastatic spread, changes in clinical behavior, morphology, and proliferation index suggest malignant progression of the tumor.

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Background: Nephrotoxicity is an important side effect of amphothericin B deoxycholate (ampho B) and cyclosporine A (CsA). The combined administration of these drugs is frequent in patients with haematological diseases undergoing allogeneic stem cell transplantation.

Aim: To assess the additional renal toxicity of ampho B given as a continuous infusion in addition to CsA.

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The antibiotics rifamycin SV and rifampicin substantially reduce sulfobromophthalein (BSP) elimination in humans. In rats, rifamycin SV and rifampicin were shown to interfere with hepatic organic anion uptake by inhibition of the organic anion transporting polypeptides Oatp1 and Oatp2. Therefore, we investigated the effects of rifamycin SV and rifampicin on the OATPs of human liver and determined whether rifampicin is a substrate of 1 or several of these carriers.

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Background: Digital clubbing has been associated with a large number of disorders. To overcome the limitation of subjective clinical assessment, several objective measurements have been developed among which the hyponychial angle was considered most accurate for quantification of finger clubbing.

Methods And Results: Here we investigated hyponychial angles in 123 healthy subjects and 515 medical inpatients from a tertiary hospital.

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Purpose: The organic anion transporting protein (Oatp)-2 has been cloned from brain and retina. It mediates transport of many endogenous and exogenous amphiphilic compounds across the plasma membrane in a sodium-independent manner. In the brain it resides at the luminal and abluminal membrane of the capillary endothelium and at the basolateral membrane of the choroid plexus epithelium.

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