The onset of diarrhea after the administration of mycophenolate mofetil (MMF) is possibly associated with the biliary excretion of its metabolite, mycophenolic acid glucuronide (MPAG). This study was undertaken to clarify the mechanism underlying the biliary excretion of MPAG. Intravenously administered mycophenolic acid (MPA, 5 mg/kg) rapidly disappeared from plasma and was efficiently excreted as MPAG in the bile of Wistar (26% of dose) and Sprague-Dawley rats (21% of dose) over 1 h. On the other hand, in spite of the rapid disappearance of MPA from plasma, the biliary excretion of MPAG was very limited in Eisai hyperbilirubinemic rats (EHBRs), which display mutations in multidrug resistance-associated protein 2 (Mrp2)/canalicular multispecific organic anion transporter, and constituted only 0.5% of dose. Instead, high levels of MPA were noted in the plasma of EHBRs. Intravenous administration of CsA (5 mg/kg) to Wistar rats significantly lowered the biliary excretion of MPAG. However, intravenously administered tacrolimus (0.1 mg/kg) failed to produce such effect. In conclusion, it is suggested that there is an efficient MPAG transport mediated by Mrp2 on the bile canalicular membrane of rat hepatocytes and that the therapeutic range of CsA potentially interferes with Mrp2. However, the therapeutic range of tacrolimus does not inhibit the transporter. Thus, it should be noted that MMF coadministered with tacrolimus instead of CsA might increase the occurrence of diarrhea related to the biliary excretion of MPAG in transplant recipients.

Significant functional MR and TR are seen in a substantial proportion of patients with longstanding AF, despite preserved LVEF. This MR/TR combination predicts poor outcome for AF patients, who may have to be treated more intensively.

No abstract

Nonselective cyclooxygenase (COX) inhibitors are potent tocolytic agents; however, they also have adverse fetal effects such as constriction of the fetal ductus arteriosus. Recently, selective COX-2 inhibitors have been used in the management of preterm labor in the hope of avoiding fetal complications. However, both COX-1 and -2 are expressed by cells of the ductus arteriosus. We used fetal lambs (0.88 gestation) to assess the ability of selective COX-2 inhibitors celecoxib and NS398 to affect the ductus arteriosus. Both selective COX-2 inhibitors decreased PGE(2) and 6ketoPGF(1alpha) production in vitro; both inhibitors constricted the isolated ductus in vitro. The nonselective COX-1/COX-2 inhibitor indomethacin produced a further reduction in PG release and an additional increase in ductus tension in vitro. We used a prodrug of celecoxib to achieve 1.4 +/- 0.6 microg/ml, mean +/- standard deviation, of the active drug in vivo. This concentration of celecoxib produced both an increase in pressure gradient and resistance across the ductus; celecoxib also decreased fetal plasma concentrations of PGE(2) and 6ketoPGF(1alpha). Indomethacin (0.7 +/- 0.2 microg/ml) produced a significantly greater fall in ductus blood flow than celecoxib and tended to have a greater effect on ductus resistence in vivo. We conclude that caution should be used when recommending COX-2 inhibitors for use in pregnant women, because COX-2 appears to play a significant role in maintaining patency of the fetal ductus arteriosus.

In patients with AF and significant functional MR occurring despite their preserved LV systolic function, the left atrium and mitral annulus were dilated and the anterior leaflet was flattened along the mitral annular plane, whereas the posterior leaflet was bent toward the LV cavity.