ABSTRACT
Drug-induced liver injury is an important clinical entity resulting in a considerable number of hospitalizations. While drug-induced cholestasis due to the inhibition of the bile salt export pump (BSEP) is well investigated, only limited information on the interaction of drugs with multidrug resistance protein 3 (MDR3) exists and its role in the pathogenesis of drug-induced cholestasis is poorly understood. Therefore, we aimed to study the interaction of drugs with MDR3 and the effect of drugs on canalicular lipid secretion in a newly established polarized cell line system that serves as a model of canalicular lipid secretion. LLC-PK1 cells were stably transfected with human Na(+)-taurocholate cotransporting polypeptide, BSEP, MDR3, and ABCG5/G8 and grown in the Transwell system. Apical phospholipid secretion and taurocholate transport were assayed to investigate the effect of selected drugs on MDR3-mediated phospholipid secretion as well as inhibition of BSEP. The established cell line displayed vectorial bile salt transport and specific phosphatidylcholine secretion into the apical compartment. The antifungal azoles, posaconazole, itraconazole, and ketoconazole, significantly inhibited MDR3-mediated phosphatidylcholine secretion. In contrast, amoxicillin clavulanate and troglitazone did not interfere with MDR3 activity. Drugs interfering with MDR3 activity did not display a parallel inhibition of BSEP. Our in vitro model for MDR3-mediated phospholipid secretion facilitates parallel screening for MDR3 and BSEP inhibitors. Our data demonstrate that the cholestatic potential of certain drugs may be aggravated by simultaneous inhibition of BSEP and MDR3.
Subject(s)
ATP Binding Cassette Transporter, Subfamily B/metabolism , Antifungal Agents/adverse effects , Chemical and Drug Induced Liver Injury/metabolism , Cholestasis/chemically induced , Cholestasis/metabolism , ATP Binding Cassette Transporter, Subfamily B, Member 1/metabolism , Animals , Azoles/pharmacology , Bile Acids and Salts/metabolism , Biological Transport/drug effects , Blotting, Western , Cholagogues and Choleretics/metabolism , Humans , LLC-PK1 Cells , Phospholipids/metabolism , Reproducibility of Results , Swine , Taurocholic Acid/metabolismABSTRACT
BACKGROUND: Migraine is very common in school-aged children, but despite a number of pharmacological and non-pharmacological options for prophylaxis, randomized controlled evidence in children is small. Evidence-based prophylactic drugs may have considerable side effects. OBJECTIVE: This study was to assess efficacy of a butterbur root extract (Petadolex) and music therapy in primary school children with migraine. DESIGN: Prospective, randomized, partly double-blind, placebo-controlled, parallel-group trial. METHODS: Following a 8-week baseline patients were randomized and received either butterbur root extract (n=19), music therapy (n=20) or placebo (n=19) over 12 weeks. All participants received additionally headache education ("treatment as usual") from the baseline onwards. Reduction of headache frequency after treatment (8-week post-treatment) as well as 6 months later (8-week follow-up) was the efficacy variable. RESULTS: Data analysis of subjects completing the respective study phase showed that during post-treatment, only music therapy was superior to placebo (p=0.005), whereas in the follow-up period both music therapy and butterbur root extract were superior to placebo (p=0.018 and p=0.044, respectively). All groups showed a substantial reduction of attack frequency already during baseline. CONCLUSION: Butterbur root extract and music therapy might be superior to placebo and may represent promising treatment approaches in the prophylaxis of paediatric migraine.
Subject(s)
Anti-Inflammatory Agents, Non-Steroidal/therapeutic use , Migraine Disorders/prevention & control , Music Therapy , Petasites , Phytotherapy , Plant Extracts/therapeutic use , Anti-Inflammatory Agents, Non-Steroidal/administration & dosage , Child , Combined Modality Therapy , Double-Blind Method , Family , Female , Follow-Up Studies , Humans , Imagery, Psychotherapy , Male , Mental Disorders/epidemiology , Migraine Disorders/psychology , Patient Compliance , Patient Education as Topic , Plant Extracts/administration & dosage , Plant Roots/chemistry , Prospective Studies , Relaxation TherapyABSTRACT
An integrated approach combining information gained by Fourier transformation, linear Markham superposition (real space) and mass-per-length measurement by scanning transmission electron microscopy was used to analyze the helical structure of the rod-like type 1 pili expressed by uropathogenic Escherichia coli strain W3110. The 3D reconstruction calculated from the experimental data showed the pili to be 6.9nm wide, right-handed helical tubes with a 19.31(+/-0.34)nm long helical repeat comprising 27 FimA monomers associated head-to-tail in eight turns of the genetic one-start helix. Adjacent turns of the genetic helix are connected via three binding sites making the pilus rod rather stiff. In situ immuno-electron microscopy experiments showed the minor subunit (FimH) mediating pilus adhesion to bladder epithelial cells to be the distal protein of the pilus tip, which had a spring-like appearance at higher magnification. The subunits FimG and FimF connect FimH to the FimA rod, the sequential orientation being FimA-FimF-FimG-FimH. The electron density map calculated at 18A resolution from an atomic model of the pilus rod (built using the pilin domain FimH together with the G1 strand of FimC as a template for FimA and applying the optimal helical parameters determined to the head-to-tail interaction model for pilus assembly) was practically identical with that of the actual 3D reconstruction.
