Journal of neurotrauma
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Journal of neurotrauma · May 2005
ReviewDesign and analysis of phase III trials with ordered outcome scales: the concept of the sliding dichotomy.
The conventional approach to the analysis of a Phase III trial in head injury or stroke takes an ordered scale measuring functional outcome and collapses the scale to a binary outcome of favorable versus unfavorable. This discards potentially relevant information which limits statistical power and moreover is not in accord with clinical practice. ⋯ The approach is also compared with the proportional odds model, which is another statistical approach that can exploit an ordered outcome scale. The approach raises issues of clinical, statistical, and regulatory importance, and we initiate what we believe needs to become a widespread debate amongst the community involved in clinical research in head injury and stroke.
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Journal of neurotrauma · May 2005
Increased mRNA expression of VEGF within the hematoma and imbalance of angiopoietin-1 and -2 mRNA within the neomembranes of chronic subdural hematoma.
The aim of the study was to determine the source of vascular endothelial growth factor (VEGF) in hematoma fluid of patients suffering from chronic subdural hematoma (CSH) and to identify the level of gene expression of the pro-angiogenic factors angiopoietin 1 (ANG-1) and ANG-2 in hematoma membranes. Samples of venous blood, hematoma fluid, and outer membrane were obtained during surgery for CSH. The numbers of mononuclear cells were determined in hematoma fluid and in venous blood samples taken from 11 patients. ⋯ A marked increase in the expression of ANG-2 mRNA over ANG-1 mRNA demonstrates a pro-angiogenic pattern in the hematoma membranes. Persistent activation of the ANG/Tie-2 system in addition to high levels of VEGF may keep the vasculature in a destabilized condition and may account for the continuous formation of new and immature blood vessels resulting in massive plasma extravasation and repeated bleeding episodes. Thus, the present study provides new evidence in favor of pro-angiogenic mechanisms playing an important role in the pathophysiology of CSH.
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Journal of neurotrauma · May 2005
Effects of glial transplantation on functional recovery following acute spinal cord injury.
Numerous efforts have been made to maximize the efficacy of treatment for spinal cord injury (SCI). Recently, oligodendrocyte-type 2 astrocyte (O-2A) progenitor cells have been reported to remyelinate focal areas of demyelinated spinal cord in adult rats. We conducted a study to investigate the therapeutic potential of transplantation of O-2A cells in a rat model of acute SCI. ⋯ Furthermore, a tract-tracing study showed that numbers of retrogradely labeled neurons increased in areas of the brain stem after O-2A-cell transplantation. The study data showed that after being transplanted into an animal with SCI, O-2A cells migrated to the area adjacent to the site of injury and differentiated into oligodendrocytes. The behavioral test and the electrophysiological and morphological studies showed that transplantation of O-2A cells may play an important role in functional recovery and the regeneration of axons after SCI.