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Summary: As part of the acute inflammatory response, neutrophils accumulate in the central nervous system af ter injury. Recently, a soluble human recombinant com plement receptor (sCR1; BRL 55730; T Cell Sciences, Inc., Cambridge, MA, U.S.A.) has been developed that inhibits the activation of both the classical and the alter native pathways of complement. sCR 1 attenuates the ef· fects of the aCUte inl1ammatory response in several mod els of injury outside the central nervous system. The role of complement in traumatic brain injury, however, re mains undefined. We hypothesized that treatment with sCRI would attenuate neutrophil accumUlation in the brain after cerebral trauma. Using a randomized, blinded protocol, 18 anesthetized Sprague-Dawley rats were pre treated with sCRl or saline (control) at both 2 hand 2 min before trauma (weight drop) to the exposed right parietal cortex. A third dose of sCRI (or saline) was given 6 h

The posterior maxilla has traditionally been one of the most difficult areas to successfully place dental implants due to poor bone quality and close approximation to the maxillary sinus. Sinus augmentation procedures have become a viable means of assuring adequate bone for the placement of dental implants in this area. However, with the techniques currently employed, a considerable variation in the quality of bone attained with the sinus augmentation procedure exists. The purpose of this in vivo study was to evaluate the healing response and bone formation stimulated by 3 doses of recombinant human osteogenic protein-1 (rhOP-1), 0.25, 0.6, and 2.5 mg OP-1 per gram of collagen matrix; natural bone mineral; or collagen matrix alone (control) placed in the maxillary sinus of adult chimpanzees. Results were assessed using clinical, histologic, and radiographic techniques. Radiographic analysis of the computed tomography scans taken at 1 week, and 2.5, 4.5, and 6.5 months revealed a more rapid mineralization with the 2.5 mg OP-1/g collagen matrix and natural bone mineral treatment groups. The incremental bone mineral density (BMD) increase for these 2 treatments from 1 week to 2.5 months was over 2.5 times the increase found with the collagen matrix alone; these 2 treatments also had a higher BMD at the most superior slices evaluated when compared to the other 3 groups. Biopsy specimens were taken at 3.5, 5.5, and 7.5 months and for all 5 treatment groups bone formation was observed at all time points in the majority of the specimens. At 7.5 months the 2.5 and 0.6 mg OP-1/g collagen matrix treatment groups had an increase in the percent bone area when compared to the matrix alone control. In conclusion, these results demonstrate that sinus augmentation with natural bone mineral or 2.5 mg OP-1/g collagen matrix induce comparable radiographic and histologic evidence of bone formation and that both of these treatments performed superior to the control group of collagen matrix alone based upon all methods of evaluation.

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