18 research outputs found
A veseátültetés első 50 éve Magyarországon
The first Hungarian kidney transplantation was performed by Andras Nemeth in Szeged in 1962, approximately 50 years ago. A preliminary agreement with Eurotransplant was signed in 2011, and special patient groups gained benefit from this cooperation in 2012, wnich lead to a full membership to Eurotransplant. This event inspired the authors to review the history of Hungarian kidney transplantation of the past 50 years, from the first operation to recent via the specific cornerstones of the transplant program. The donor of the first Hungarian kidney transplantation was the brother of the recipient. The operation itself was technically successful, but the lack of immunosuppression caused graft rejection, and the patient died after 79 days. His brother, the donor, is still healthy, after 50 years, and he encourages everybody to donate organs. Organized kidney transplant program started more than 10 years later, such as 1973, in Budapest. The program was supported by the Ministry of Health. New centers joined the program later, Szeged in 1979, Debrecen in 1991 and Pecs in 1993. These four transplant centers work currently in Hungary, and 6611 kidney transplantation has been performed up to the end of year 2012. Orv. Hetil., 2013, 154, 846-849
Gadolinium (III) loaded nanoparticulate zeolites as potential high-field MRI contrast agents: relationship between structure and relaxivity
The effects of dealumination, pore size, and calcination on the efficiency (as expressed in the relaxivity) of Gd3+-loaded zeolites for potential application as magnetic resonance imaging (MRI) contrast agents were studied. Partial dealumination of zeolites NaY or NaA by treatment with (NH4)(2)SiF6 or diluted HCl resulted in materials that, upon loading with Gd3+, had a much higher relaxivity than the corresponding non-dealuminated materials. Analysis of the H-1 NMR dispersion profiles of the various zeolites showed that this can be mainly ascribed to an increase of the amount of water inside the zeolite cavities as a result of the destruction of walls between cavities. However, the average residence time of water inside the Gd3+-loaded cavities did not change significantly, which suggests that the windows of the Gd3+-loaded cavities are not affected by the dealumination. Upon calcination, the Gd3+ ions moved to the small sodalite cavities and became less accessible for water, resulting in a decrease in relaxivity. The important role of diffusion for the relaxivity was demonstrated by a comparison of the relaxivity of Gd3+-loaded zeolite NaY and NaA samples. NaA had much lower relaxivities due to the smaller pore sizes. The transversal relaxivities of the Gd3+-doped zeolites are comparable in magnitude to the longitudinal ones at low magnetic fields (< 60 MHz). However at higher fields, the transversal relaxivities steeply increased, whereas the longitudinal relaxivities decreased as field strength increased. Therefore, these materials have potential as T-t MRI contrast agents at low field, and as T-t agents at higher fields.</p
DOTA-M8 : an extremely rigid, high-affinity lanthanide chelating tag for PCS NMR spectroscopy
A new lanthanide chelating tag (M8) for paramagnetic labeling of biomolecules is presented, which is based on an eight-fold, stereoselectively methyl-substituted DOTA that can be covalently linked to the host molecule by a single disulfide bond. The steric overcrowding of the DOTA scaffold leads to an extremely rigid, kinetically and chemically inert lanthanide chelator. Its steric bulk restricts the motion of the tag relative to the host molecule. These properties result in very large pseudocontact shifts (<5 ppm) and residual dipolar couplings (<20 Hz) for Dy-M8 linked to ubiquitin, which are unprecedented for a small, single-point-attachment tag. Such large pseudocontact shifts should be well detectable even for larger proteins and distances beyond approximately 50 A. Due to its exceptionally high stability and lanthanide affinity M8 can be used under extreme chemical or physical conditions, such as those applied for protein denaturation, or when it is undesirable that buffer or protein react with excess lanthanide ions