Let R s [ R be a G-graded ring. We describe all types of gradings on R ifG is torsion free and R is Artinian semisimple. If R is a matrix algebra over an algebraically closed field F, then we give a description of all G-gradings on R provided that G is an abelian group. In the case of an abelian group G we also classify all finite-dimensional graded simple algebras and finite-dimensional graded division algebras over an algebraically closed field of characteristic zero. ᮊ 2001Academic Press

Recombinant human erythropoietin has been used to treat anemia associated with chronic renal disease. This paper provides a comprehensive comparative analysis of Dynepo and three other commercial erythropoiesis stimulating agents, Eprex, NeoRecormon and Aranesp. We found significant differences in the type, levels and amount of O-acetylation of sialic acids. Sialic acids and O-acetylation present provide protection from clearance from circulation. Aranesp had up to six O-acetyl groups attached to the sialic acids. Eprex and NeoRecormon had only minor amounts of O-acetylation while Dynepo had none. Dynepo had no Neu5Gc, which is potentially immunogenic for humans. Dynepo contained the least amount of disialylated and Aranesp the highest amount of tetrasialylated glycans. NeoRecormon and Eprex contained more trisialylated, but less tetrasialylated glycans than Dynepo and Aranesp. Dynepo had the highest amount of tetraantennary glycans and the lowest amounts of triantennary glycans with a β1-6-GlcNAc linkage. All the samples contained poly-N-acetyl-lactosamine repeats with Dynepo having the least. The major N-acetyl-lactosamine extensions in Dynepo and Aranesp were on biantennary glycans, whereas in NeoRecomon and Eprex they were on triantennary glycans. The sLe(x) epitope was only detected in Dynepo.

Let R be a finite-dimensional algebra over an algebraically closed field F graded by an arbitrary group G. We prove that R is a graded division algebra if and only if it is isomorphic to a twisted group algebra of some finite subgroup of G. If the characteristic of F is zero or char F does not divide the order of any finite subgroup of G then we prove that R is graded simple if and only if it is a matrix algebra over a finite-dimensional graded division algebra. (Y. A. Bahturin), S.Sehgal@math.ualberta.ca (S.K.Sehgal), zaicev@mech.math.msu.su (M. V. Zaicev).

Lichenoid tissue reaction or interface dermatitis embrace several clinical conditions, the prototype of which is lichen planus and its variants, drug induced lichenoid dermatitis, special forms of lichenoid dermatitis, lichenoid dermatitis in lupus erythematosus, and miscellaneous disorders showing lichenoid dermatitis, the salient clinical and histological features of which are described to facilitate their diagnosis. Background of lichenoid reaction pattern has been briefly outlined to enlighten those interested in this entity.

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