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Previous reports showed the therapeutic effect of transplants of bone marrow stromal cells (BMSC) after incomplete traumatic spinal cord lesions. We studied the effect of this form of therapy in chronically paraplegic Wistar rats due to severe spinal cord injury (SCI). Rats were subjected to weight-drop impact causing paraplegia, and BMSC or phosphate buffered saline (PBS) was injected into spinal cord 3 months after injury. Functional outcome was measured using the Basso-Beattie-Bresnehan score until sacrifice of the animals, 4 weeks after transplantation. At this time, samples of spinal cord tissue were studied histologically. The results showed a clear and progressive functional recovery of the animals treated with BMSC transplantation, compared to controls. Grafted BMSC survived into spinal cord tissue, forming cell bridges within the traumatic centromedullary cavity. In this tissue, cells expressing neuronal and astroglial markers can be seen, together with a marked ependymal proliferation, showing nestin-positivity. These findings suggest the utility of BMSC transplantation in chronically established paraplegia.

Next to chromosome 22 anomalies, deletions of the short arm of chromosome 1 have previously been described as the most frequent alteration detected by cytogenetic analysis of meningiomas. To determine the incidence of these deletions, we have analyzed a series of 50 meningiomas for the loss of alleles at four chromosome 1 loci. Thirteen samples displayed LOH for the markers studied; in one instance, the results were compatible with loss of the entire chromosome 1, whereas in the other 12 samples deletions of the short arm were observed. Eleven of the meningiomas had previously been shown to have loss of alleles on chromosome 22, and 12 of them were characterized by increased tumor aggressiveness. These findings suggest that deletion of Ip (or the alteration of a locus located there) might represent a secondary, but nonrandom alteration in meningiomas, perhaps contributing to meningioma tumor progression.