title: Chronic rhinosinusitis osteoblasts differ in cellular properties from normal bone.
abstract: BACKGROUND
  Osteitis, characterized by bony thickening and remodeling, is often considered a hallmark of recalcitrant rhinosinusitis. However, there is limited literature examining the bone in chronic rhinosinusitis (CRS) pathology. In this study we cultured osteoblasts from bone harvested during sinus surgery as well as from nondiseased controls to compare their cellular properties.
  
  
  METHODS
  Sinus bone was collected during sinus and skull-base surgery and placed in proliferation media. Outgrowth of cells occurred at 2 weeks and the cells were confirmed to be osteoblasts by alkaline phosphatase staining. Cellular adhesion was determined by replating and counting adhered cells at 4 hours. Proliferation of cells plated for 24 hours was assayed by measuring [(3) H]-thymidine incorporation. Calcium content was measured by changing cells to differentiation media and measuring the calcium content on days 7, 14, and 21.
  
  
  RESULTS
  Alkaline phosphatase assay showed more than 90% of osteoblasts staining in all samples. Osteoblasts from patients with CRS had significant decreases in adhesion (p < 0.01) compared to osteoblasts from skull-base patients. There was a significant (p < 0.05) increase in calcium content in rhinosinusitis samples compared with the nondiseased sinus bone samples.
  
  
  CONCLUSIONS
  To date, this is the first known study that shows a direct comparison of osteoblast properties between patients with and without CRS. Our results indicate that there are fundamental phenotypic differences in adhesion and mineralization between osteoblasts in patients with CRS compared to controls.
authors.affiliation: Department of Otolaryngology, University of Connecticut Health Center, Farmington, CT.
authors.forename: Patrick R
authors.initials: PR
authors.lastname: Stevens
authors.forename: Belachew
authors.initials: B
authors.lastname: Tessema
authors.forename: Seth M
authors.initials: SM
authors.lastname: Brown
authors.forename: Kourosh
authors.initials: K
authors.lastname: Parham
authors.forename: Gloria
authors.initials: G
authors.lastname: Gronowicz
mesh_terms: D000328:Adult; D000368:Aged; D000469:Alkaline Phosphatase / Q000378:metabolism; D016723:Bone Remodeling / Q000502:physiology; D016022:Case-Control Studies; D002478:Cells, Cultured; D002908:Chronic Disease; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010006:Osteoblasts / Q000473:pathology*; D010641:Phenotype; D012220:Rhinitis / Q000473:pathology*; D012852:Sinusitis / Q000473:pathology*
chemical_list: D000469:Alkaline Phosphatase
keywords: bone remodeling; nasal polyps; osteitis; osteoblast culture; sinusitis