Myelination is a concerted mechanism tightly regulated in the brain. Although several factors are known to participate during this process, the complete sequence of events is far from being fully elucidated. Separate effects of apotransferrin (aTf) and thyroid hormone (TH) are well documented on rat myelin formation. TH promotes the maturation of oligodendrocyte progenitors (OPCs) into myelinat...

The speciations of two drug candidate ligands, 2-hydroxypyridine-N-oxide (Hhpno) and 2-mercaptopyridine-N-oxide (Hmpno), with vanadate (V(V)) were determined at 25.0 degrees C and 0.20 mol dm(-3) KCl by pH-metric and (51)V-NMR methods. At pH 7.4, the two predominant compounds with both ligands are the VO(2)L(2) and VO(2)L(OH). NH(4)[VO(2)(hpno)(2)] x 3 H(2)O was prepared in solid form, and its ...

The endocytosis of diferric transferrin and accumulation of its iron by freshly isolated rabbit reticulocytes was studied using 6sFe-'261-tran~ferrin. Internalized transferrin was distinguished from surface-bound transferrin by its resistance to release during treatment with Pronase at 4 "C. Endocytosis of diferric transferrin occurs at the same rate as exocytosis of apotransferrin, the rate co...

Pseudomonas aeruginosa produces siderophores, pyoverdin and pyochelin, for high-affinity iron uptake. To investigate their contribution to P. aeruginosa infections, we constructed allelic exchange mutants from strain PAO1 which were deficient in producing one or both of the siderophores. When inoculated into the calf muscles of immunosuppressed mice, pyochelin-deficient and pyoverdin-deficient ...

This in vitro study evaluates the effect of aluminum (Al3+) on osteocalcin, a small protein that is produced by the osteoblast. After stimulation with various doses of 1,25-dihydroxyvitamin D3 [1,25(OH)2D3; 10(-11) to 10(-9) M], osteocalcin was consistently lower in the culture medium of ROS 17/2 osteoblastic cells conditioned with 5 microM Al(3+)-saturated transferrin (AlTR) than in apotransfe...

The transferrin-mediated pathway of iron uptake has been characterized in mouse teratocarcinoma stem cells in culture. These cells were chosen for the characterization because of their unique capacity to be converted to normalcy and to undergo complete and orderly differentiation into all tissues after microinjection into early mouse embryos. Therefore, the cells provide the possibility of expe...

This thesis is focused on several aspects of neural crest biology, largely related to two main issues: 1) understanding its mechanisms of migration and 2) analyzing the potential of neural crest stem cells or their derivatives for nervous system repair. If repair is the aim, knowledge of both timing and events leading to axonal degeneration is required in order to block it and/or increase regen...