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Bone marrow osteogenesis in senile osteoporotic bone is impaired and, as such, may have significant implications on the successful outcome of fracture repair. Here we utilize a well-established murine model of senile osteoporosis, the P6 strain of senescenceaccelerated mice (SAMP6), to investigate fracture healing in aged osteoporotic bone. A femoral osteotomy was created in SAMP6 and in nonosteoporotic age-matched control R1 senescence-resistant mice (SAMR1). The course of fracture healing was evaluated over a period of 42 days using quantitative mCT and histological analysis. The differentiation capabilities of bone mesenchymal progenitor cells derived from SAMP6 and SAMR1 mice was examined, and their osteogenic potential determined. Although preliminary in vitro analysis confirmed that bone marrow-derived stem cells (BMSC) isolated from SAMP6 mice had a reduced osteogenic capacity, no significant deficit in fracture repair as determined by quantitative mCT could be detected. This was supported by histology assessment, where complete bridging of the fracture gap was evident by day 28 and was fully healed day 42 in both SAMP6 and SAMR1 mice. Further in vitro studies revealed that periostealderived progenitor cells (PDPC) isolated from SAMP6 mice had an osteogenic potential comparable to that observed in SAMR1 mice. In conclusion, fracture healing in SAMP6 mice is not detrimentally affected by impairment of BMSC osteogenesis, suggesting that bone marrow-mediated repair processes are dispensable for normal bone healing in this senile osteoporotic fracture model. Furthermore, the influence of PDPC in the repair process may partly explain the absence of any detectable deficits in fracture repair in SAMP6 mice. ß

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Transillumination-guided intubation is a useful back-up method when laryngoscopic intubation proves to be difficult or impossible. The Trachlight™ (Laerdal, N-4001 Stavanger, Norway) is suited for both nasal and oral use. Intubation times (intubation time) and success rates (success rate) for nasal and oral intubation with the Trachlight were compared.Twenty-four medical students, inexperienced in intubation were instructed in the use of the Trachlight. A demonstration also was performed. Subsequently, they were asked to intubate a Laerdal Airway Management Trainer™ (Laerdal, Stavanger, Norway) using the Trachlight. Each student intubated 10 times orally and 10 times nasally (five times through the right and five times through the left nostril). The succession of the students was randomized The intubation times were measured and the position of the tube noted. Nasal and oral intubation times for the tenth trial (steady state conditions) were compared using the rank-order test for paired observations. Oral and nasal success rates were compared using the sign test for paired observations.The differences between nasal and oral intubation concerning intubation time and the success rates were not significant. Nasal intubation with the Trachlight seems to be more difficult than the oral intubation.