6 research outputs found
Cyclosporine I.V. Dose Adjustment in Patients with Hematopoietic Stem Cell Transplantation
Corrigendum: Insights into the effects of hyperlipoproteinemia on cyclosporine a biodistribution and relationship to renal function
The purpose of this study was to assess the effect of hyperlipoproteinemia on the biodistribution of cyclosporine A (CyA), an extensively lipoprotein bound immunosuppressant, in a rat model and to determine the potential toxicological significance of this effect. Normolipidemic and hyperlipoproteinemic rats were given a single 5 mg/kg dose of CyA as intravenous bolus and at selected times postdose, tissues, blood, and plasma were harvested and assayed for CyA content. Hyperlipoproteinemia was induced by intraperitoneal injection of 1 g/kg poloxamer 407. Compared with normolipidemic animals, hyperlipoproteinemic rats had higher plasma, blood, kidney, and liver CyA concentrations. In contrast, in heart and spleen the concentrations were decreased in hyperlipoproteinemia. The nephrotoxic effect of CyA was also evaluated in normolipidemic and hyperlipoproteinemic rats after 7 days of dosing with 20 mg/kg/day. In both groups of animals, repeated doses of CyA were associated with equivalent decreases in creatinine and urea clearances compared with matching control and predose baseline measures. The concentrations of drug in kidney were equivalent at the conclusion of the study. However, despite these similarities there was microscopic evidence of more severe changes in the kidneys in the hyperlipoproteinemic rats, which also experienced a significant decrease in body weight compared with the normolipedemic animals. In conclusion, the distribution of CyA to kidneys was enhanced in poloxamer 407 – induced hyperlipoproteinemic rats after single doses, and with repeated doses there was an apparent greater adverse effect on these animals compared with normolipidemic animals
Thermal expansion and high temperature structure evolution of zoisite by single-crystal X-ray and neutron diffraction
High-pressure properties of diaspore, AlO(OH)
The structural compression mechanism and compressibility of diaspore, AlO(OH), were investigated by in situ single-crystal synchrotron X-ray diffraction at pressures up to 7 GPa using the diamond-anvil cell technique. Complementary density functional theory based model calculations at pressures up to 40 GPa revealed additional information on the pressure-dependence of the hydrogen-bond geometry and the vibrational properties of diaspore. A fit of a second-order Birch-Murnaghan equation of state to the p-V data resulted in the bulk modulus B (0) = 150(3) GPa and B (0) = 150.9(4) GPa for the experimental and theoretical data, respectively, while a fit of a third-order Birch-Murnaghan equation of state resulted in B (0) = 143.7(9) GPa with its pressure derivative B'= 4.4(6) for the theoretical data. The compression is anisotropic, with the a-axis being most compressible. The compression of the crystal structure proceeds mainly by bond shortening, and particularly by compression of the hydrogen bond, which crosses the channels of the crystal structure in the (001) plane, in a direction nearly parallel to the a-axis, and hence is responsible for the pronounced compression of this axis. While the hydrogen bond strength increases with pressure, a symmetrisation is not reached in the investigated pressure range up to 40 GPa and does not seem likely to occur in diaspore even at higher pressures. The stretching frequencies of the O-H bond decrease approximately linearly with increasing pressure, and therefore also with increasing O-H bond length and decreasing hydrogen bond length
