ABSTRACT
OBJECTIVES: The dental pulp stem cells (DPSCs) of six donors (three young donors aged < 19 years and three adult donors aged > 25 and < 30 years) were characterized for their stem cell marker expression and differentiation potential to study the effect of donor age on DPSCs in vitro. METHODS: DPSCs were cultured in αMEM supplemented with 20% fetal calf serum (conventional conditions) or on fibronectin-coated flasks with neurobasal medium supplemented with B27, bFGF and EGF (alternative conditions). DPSCs were characterized by immunofluorescence staining to detect the neural crest/mesenchymal stem cells markers P75 and CD146, respectively. The differentiation potential was tested by the induction of DPSCs into osteogenic, adipogenic and glial lineages and then by detecting the corresponding markers osteocalcin, lipidtox and S100ß, respectively. RESULTS: The DPSCs of the young donors expressed CD146 only under the conventional conditions and expressed P75 regardless of the culture conditions. However, the DPSCs of adult donors expressed CD146 only under the alternative conditions and expressed P75 only under conventional conditions. Only the DPSCs of the young donors differentiated into the glial linage. The DPSCs of the adult donors differentiated more efficiently into the adipogenic linage. Osteogenic differentiation was comparable. CONCLUSION: Donor age affects the expression of stem cell markers and differentiation potential of DPSCs. Moreover, the effect of culture conditions on DPSCs is age dependent.
ABSTRACT
OBJECTIVES: The aim of the study was to evaluate the diagnostic accuracy of various single photon emission computed tomography (SPECT) quantitative methods in patients with condylar hyperplasia (CH) and to investigate whether normal condylar activity changes with age. PATIENTS AND METHODS: We analyzed the SPECT images of 33 patients with CH and those of 16 control individuals. Regions of interest (ROIs) were drawn on whole condyle, or fixed-size ROIs were drawn on both condyles and the clivus on the slice with higher activity [a two-dimensional (2D) approach] and on the summation of five adjacent transaxial slices [a three-dimensional (3D) approach]. A percentage difference between both condyles of above 10% or a cutoff value of 1.44 or 1.88 for abnormal condyle/clivus ratio was considered abnormal. RESULTS: Seventeen patients with active CH, 16 with inactive CH, and 16 control individuals were evaluated. The highest sensitivity and highest specificity were observed for the whole-condyle approach (88 and 87%, respectively), followed by the percentage 2D maximum condyle/total (82.4 and 81.3%, respectively). The condyle/clivus ratio yielded low sensitivity for both 2D and 3D approaches. No effect of age on condylar activity was demonstrated. No statistically significant difference in condyle/clivus ratio was evident between patients with active and those with inactive CH. CONCLUSION: Use of 2D maximum fixed-size ROI and percentual difference in condylar activity offers optimal diagnostic accuracy in patients with CH and should be encouraged in future studies. The condyle/clivus ratio offers suboptimal results and cannot, therefore, be recommended. No effect of age on normal condylar activity was demonstrated.
