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Objective The Epstein-Barr virus (EBV) is utilized as a tool in the study of cellular biology because of its capacity to transform B-lymphocytes. For this reason, EBV is used in conservation of human B-lymphocytes for long periods for subsequent evaluation of lysosomal hydrolase activity. Lymphoblastoid cell lines have several advantages for use over other cell types, such as prompt availability and possibility to develop, characterize and standardize cell banks, to test effects of promising pharmaceutical reagents. The study below presents biochemical data that demonstrate validity of lymphoblastoid cell lines for diagnosis of GM1-gangliosidosis, Gaucher, Fabry and Pompe diseases and mucopolysaccharidosis type I. Materials and methods Cultures were prepared from peripheral blood, collected from 25 normal subjects and 13 affected individuals. Enzyme activities and immunohistochemistry (IHC) were measured. Activities of enzymes beta-galactosidase, beta-glucosidase, alpha-iduronidase, alpha-galactosidase and alpha-glucosidase were measured before and after cryopreservation for 180 days. Enzymatic activity was measured when transformation was confirmed by IHC. Results We observed some significant alterations in enzymatic activity of non-cultured cells when compared to others that had been cultured for 12 days and kept frozen for 180 days. Conclusions However, these alterations did not invalidate use of the technology of transformation of lymphoblastoid cell lines with EBV, to diagnose the diseases mentioned above, in view of the fact that the cultured cells, before and after freezing, demonstrated similar enzymatic activities.

This paper reports the production and characterisation of BGO scintillators doped with Cr3+. Single phase Bi4Ge3O12 in pure state and containing up to 1% of the Cr3+ was produced via a solid state route and its luminescent properties were investigated (absorption and emission spectra and radioluminescence). When excited at 200-230 nm, pure BGO ceramics exhibit a wide photoluminescent band emission centred at 500 nm, assigned to Bi3+ internal transitions. For the doped samples under the same excitation, this wide band was superposed by the emission peaks of the dopant. Computer modelling was employed to help to understand the Cr3+ - doping process in the BGO matrix. The incorporation of the Cr3+ dopant was modelled considering substitution at either Bi3+ or Ge4+ sites. A range of possible charge compensation schemes were devised and the corresponding reactions were used to calculate the energetically optimal defect. The predicted symmetry of the Cr3+ dopant was used to understand the optical properties of the material. (© 2007 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)

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