Ian D. Duncan

Learn More
The remarkable developmental potential and replicative capacity of human embryonic stem (ES) cells promise an almost unlimited supply of specific cell types for transplantation therapies. Here we describe the in vitro differentiation, enrichment, and transplantation of neural precursor cells from human ES cells. Upon aggregation to embryoid bodies,(More)
Self-renewing, totipotent embryonic stem (ES) cells may provide a virtually unlimited donor source for transplantation. A protocol that permits the in vitro generation of precursors for oligodendrocytes and astrocytes from ES cells was devised. Transplantation in a rat model of a human myelin disease shows that these ES cell-derived precursors interact with(More)
Magnetic resonance (MR) tracking of magnetically labeled stem and progenitor cells is an emerging technology, leading to an urgent need for magnetic probes that can make cells highly magnetic during their normal expansion in culture. We have developed magnetodendrimers as a versatile class of magnetic tags that can efficiently label mammalian cells,(More)
Oligodendrocytes are critical for the development of the plasma membrane and cytoskeleton of the axon. In this paper, we show that fast axonal transport is also dependent on the oligodendrocyte. Using a mouse model of hereditary spastic paraplegia type 2 due to a null mutation of the myelin Plp gene, we find a progressive impairment in fast retrograde and(More)
As oligodendrocytes wrap axons of the central nervous system (CNS) with insulating myelin sheaths, sodium channels that are initially continuously distributed along axons become segregated into regularly spaced gaps in the myelin called nodes of Ranvier. It is not known whether the regular spacing of nodes results from regularly spaced glial contacts or is(More)
Demyelination is a common pathological finding in human neurological diseases and frequently persists as a result of failure of endogenous repair. Transplanted oligodendrocytes and their precursor cells can (re)myelinate axons, raising the possibility of therapeutic intervention. The migratory capacity of transplanted cells is of key importance in(More)
The apparent diffusion tensor (ADT) was measured in excised and fixed spinal cords from myelin-deficient (md) rats and age-matched controls. These data were used to obtain the principal diffusivities of the ADT, and also the scalar invariant parameters _D (averaged principal diffusivity) and A(sigma) (anisotropy index) for four white matter and two gray(More)
During oligodendrocyte development, signals relevant to process formation must be transduced into appropriate changes in cytoskeletal organization. We have explored how microtubules and microfilaments interact during the outgrowth and branching of oligodendrocyte processes in culture. We observed that microfilaments are enriched in the peripheral region(More)
We have explored the use of minocycline, a tetracycline with antiinflammatory properties, to treat chronic relapsing-remitting experimental allergic encephalomyelitis, an animal model of multiple sclerosis. Therapeutic treatment with minocycline dramatically suppresses ongoing disease activity and limits disease progression. Disease suppression is(More)
During the last few years, the therapeutic use of stem and progenitor cells as a substitute for malfunctioning endogenous cell populations has received considerable attention. Unlike their current use in animal models, the introduction of therapeutic cells in patients will require techniques that can monitor their tissue biodistribution noninvasively. Among(More)