Objective
To further understand the mechanisms of perturbations in bone remodeling following severe burn injury, the biomechanical properties, genetic expression, and serological markers were evaluated in rodents at six time intervals within six weeks following injury. Moreover, these effects were observed in rodent tibia and lumbar vertebrae to explore possible skeletal-site localization of this pathologic bone loss.
Methods
Rodents underwent either thermal injury (100°C water, 30 seconds, 30% BSA) or sham burn. Bone mineral density was evaluated though peripheral quantitative computer tomography, while specialized apparatus measured the weight bearing capacity of tibia and lumbar vertebrae. Markers of bone resorption (RANK-ligand, osteocalcin) and bone formation (osteoprotegrin, procollagenase type 1 alpha 2) were measured at 7, 14, and 21 days following injury, while serum RANK-ligand levels were observed at these time intervals.
Results
Rodent body mass, bone mineral density, and weight bearing capacity were negatively influenced both acutely and several weeks following burn injury. Moreover, a genetic expression profile favoring increased bone resorption and lower bone formation was demonstrated. Our serum analysis findings of significantly increased RANKL 1 and 2 weeks following injury support the increased expression of bone resorption markers. Furthermore, these effects occurred sooner and were more pronounced in the rodent lumbar vertebrae than tibia.
Conclusions
These results suggest that severe burn injury results in perturbations in bone remodeling secondary to increased bone resorption and diminished bone formation, impacting both bone mineral density and weight bearing capacity. Furthermore, these processes had a skeletal-site effect more pronounced in the lumbar vertebrae. With a better understanding of the mechanisms of burn-injury bone loss, targeted therapies can be implemented to improve long term clinical outcomes.
Combined large cell neuroendocrine carcinoma (LCNEC) and squamous cell carcinoma (SCC) of the H&N are exceptionally rare. We present the case of combined p16 negative SCC and LCNEC of the oropharynx treated with combination chemotherapy. This is the third reported case of combined neuroendocrine carcinoma and SCC of the oropharynx.
Combined large cell neuroendocrine carcinoma (LCNEC) and squamous cell
carcinoma (SCC) of the H&N is exceptionally rare. We present the case
of combined p16 negative SCC and LCNEC of the oropharynx treated with
combination chemotherapy. This is the third reported case of combined
neuroendocrine carcinoma and SCC of the oropharynx.
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