Pregnancy in WD patients on anticopper therapy is safe. The spontaneous abortion rate in treated patients was lower than that in therapy-naïve patients. Although the teratogenic potential of copper chelators is a concern, the rate of birth defects in our cohort was low. Treatment for WD should be maintained during pregnancy, and patients should be monitored closely for hepatic and neurological symptoms. (Hepatology 2018;67:1261-1269).
Background and AimsA key pathogenetic feature of ulcerative colitis [UC] is an intrinsic low mucus phosphatidylcholine[PC] content. Recently, a paracellular transport for PC across tight junctions[TJs] was described, suggesting TJ disturbance as a cause of diminished luminal PC transport. Therefore, we aimed to generate mutant mice with TJ deletion to evaluate whether a UC phenotype developed.MethodsCL57BL/6 control wild-type mice were compared to mutant mice with tamoxifen-induced villin-Cre-dependent intestinal deletion of kindlin 1 and 2.ResultsElectron microscopy of mucosal biopsies obtained from both mutants before overt inflammation following only 2 days of tamoxifen exposure revealed a defective TJ morphology with extended paracellular space and, by light microscopy, expanded mucosal crypt lumina. PC secretion into mucus was reduced by >65% and the mucus PC content dropped by >50%, causing a >50 % decrease of mucus hydrophobicity in both mutants. Consequently, the microbiota was able to penetrate the submucosa. After 3 days of tamoxifen exposure, intestinal inflammation was present in both mutants, with loose bloody stools as well as macroscopic and histological features of colitis. Oral PC supplementation was able to suppress inflammation. By analogy, colonic biopsies obtained from patients with UC in remission also showed a defective epithelium with widened intercellular clefts, and enlarged crypt luminal diameters with functionally impaired luminal PC secretion.ConclusionsGenetic mouse models with intestinal deletion of kindlin 1 and 2 resulted in TJ deletion and revealed pathophysiological features of impaired PC secretion to the mucus leading to mucosal inflammation compatible with human UC.
Phosphatidylcholine (PC) is the most abundant phospholipid in intestinal mucus, indicative of a specific transport system across the mucosal epithelium to the intestinal lumen. To elucidate this transport mechanism, we employed a transwell tissue culture system with polarized CaCo2 cells. It was shown that PC could not substantially be internalized by the cells. However, after basal application of increasing PC concentrations, an apical transport of 47.1±6.3nmolh(-1)mMPC(-1) was observed. Equilibrium distribution studies with PC applied in equal concentrations to the basal and apical compartments showed a 1.5-fold accumulation on the expense of basal PC. Disruption of tight junctions (TJ) by acetaldehyde or PPARγ inhibitors or by treatment with siRNA to TJ proteins suppressed paracellular transport by at least 50%. Transport was specific for the choline containing the phospholipids PC, lysoPC and sphingomyelin. We showed that translocation is driven by an electrochemical gradient generated by apical accumulation of Cl(-) and HCO3(-) through CFTR. Pretreatment with siRNA to mucin 3 which anchors in the apical plasma membrane of mucosal cells inhibited the final step of luminal PC secretion. PC accumulates in intestinal mucus using a paracellular, apically directed transport route across TJs.
Aims Impaired liver function often necessitates drug dose adjustment to avoid excessive drug accumulation and adverse events, but a marker for the extent of the required adjustment is lacking. The aim of this study was to investigate whether Child–Pugh (CP) and model for end‐stage liver disease (MELD) scores correlate with drug clearance. Methods Midazolam was used as a CYP3A probe and its pharmacokinetics were analyzed in 24 patients with mild to severe liver cirrhosis (n = 4, 10 and 10 with CP class A, B and C, respectively) and six patients without liver disease. Results Both scores correlated well with unbound midazolam clearance (CLu), unbound midazolam fraction and half‐life (all P < 0.01), whereas the unbound steady‐state volume of distribution was not significantly changed. In patients with severe liver cirrhosis unbound midazolam clearance was only 14% of controls (CP C: CLu = 843 ± 346 l h−1, MELD ≥ 15: CLu = 805 ± 474 l h−1, controls: CLu = 5815 ± 2649 l h−1, P < 0.01). Conclusion The correlation with unbound midazolam clearance suggests that either score predicts the metabolic capacity of CYP3A, the most relevant drug metabolizing enzyme subfamily in humans.
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