Electrophilic substitution in the d-metal hexacyanoferrate(II) gelatin-immobilized matrix systems

Data of electrophilic substitution processes proceeding into the d-metal hexacyanoferrate(II) gelatin-immobilized matrix systems when they are in contact with aqueous solutions of chlorides of d-elements have been systematized and generalized. The bibliography includes 94 references.

Heparan sulfate proteoglycan syndecan-3 is a novel receptor for GDNF, neurturin, and artemin

Glial cell line–derived neurotrophic factor (GDNF) family ligands (GFLs) are potent survival factors for dopaminergic neurons and motoneurons with therapeutic potential for Parkinson’s disease. Soluble GFLs bind to a ligand-specific glycosylphosphatidylinositol-anchored coreceptor (GDNF family receptor α) and signal through the receptor tyrosine kinase RET. In this paper, we show that all immobilized matrix-bound GFLs, except persephin, use a fundamentally different receptor. They interact with syndecan-3, a transmembrane heparan sulfate (HS) proteoglycan, by binding to its HS chains with high affinity. GFL–syndecan-3 interaction mediates both cell spreading and neurite outgrowth with the involvement of Src kinase activation. GDNF promotes migration of cortical neurons in a syndecan-3–dependent manner, and in agreement, mice lacking syndecan-3 or GDNF have a reduced number of cortical γ-aminobutyric acid–releasing neurons, suggesting a central role for the two molecules in cortical development. Collectively, syndecan-3 may directly transduce GFL signals or serve as a coreceptor, presenting GFLs to the signaling receptor RET.

Novel modification of elemental silver formed in Ag4[Fe(CN)6]-gelatin-immobilized matrix Implants

Ag4[Fe(CN)6]→Ag reduction process occurring in Ag4[Fe(CN)6]- gelatin-immobilized matrices, has been studied. In the course of reduction, these matrices are in a contact with water-alkaline solu-tion containing tin(II) dichloride along with an organic or inorganic compound capable of forming a stable soluble complex with Ag(I). It has been found that the substance formed in the gelatin matrix, is almost pure elemental silver, which consists two various phases which are distinguished by their optical and X-ray diffraction parameters.