Effects of Nitrurized Titanium on Microhardness and Human Dental Pulp Stem Cell Adhesion and Differentiation.

To compare the Vickers microhardness, surface roughness, initial adhesion, and osteogenic differentiation on titanium (Ti) and nitrurized titanium (NTi) plates were treated by UV irradiation and chitosan. Each plate was subjected to Vickers hardness with a pressure of 2.9 N for 10 seconds and roughness evaluation by atomic force microscope (AFM) analysis. Three groups of each type of plates were tested: control (C), ultraviolet irradiation (UV), and chitosan (Q). The UV group was exposed to UV-irradiation for 20 min at 253.7 nm (52 µW/cm2). The Q group was coated with 1% chitosan, and the C group had no treatment. The osteoblasts (2 × 106 cells/mL) were inoculated in each group for 60 min and their viability was determined by the MTT bioassay. Osteogenic differentiation was performed over 4 weeks and determined by alizarin red staining. The mean was analyzed with the Shapiro-Wilks, Kruskall-Wallis, and Mann-Whitney U tests of normality (n = 9/gp). The NTi plates hardness (125.1 ± 4.01 HV) was higher (P = 0.026) than the Ti plates (121.3 ± 2.23 HV). The surface topography was: NTi (Ra = 0.098 µm) and Ti (Ra = 0.212 µm). The quantification of cell adhesion was: Ti + Q = 123 ± 4.9% (P < 0.05) < NTi + Q = 107 ± 3.3% < Ti = 100 ± 10.7% < NTi = 72 ± 6.8% < NTi + UV = 71 ± 4.4% < Ti + UV = 69 ± 3.5%, regardless the plates, the presence of chitosan induce a faster osteogenic differentiation. The Ti + Q plates tested the highest cell attachment and osteogenic adhesion suggesting their potential use of chitosan for cell-implant interaction.

Effect of Neoadjuvant Hormonal Therapy of Surgical Margin Status in Patients with Prostate Cancer Treated by Radical Prostatectomy / Journal of Rural Medicine

(Objective) Neoadjuvant hormonal therapy (NHT) before radical prostatectomy promotes the downstaging of primary lesions. A retrospective analysis was conducted of the relationship between NHT durations and positive surgical margin rates, as well as between positive surgical margin rates and three types of prostatectomy (antegrade radical prostatectomy, retrograde radical prostatectomy, and laparoscopic radical prostatectomy (LRP)).;(Materials and Methods) This study was a retrospective analysis of 257 patients treated with radical prostatectomy during the three years between April 2002 and March 2005. Of the 257 patients, 190 were treated by NHT. NHT durations were classified into “not conducted,” “<1 month,” “1-3 month,” “3-6 month” and “>6 month,” and the relationship between positive surgical margin rates and NHT durations was investigated. Seventy-four patients underwent antegrade radical prostatectomy, 131 were treated with retrograde radical prostatectomy, and 52 underwent LRP. Positive surgical margin rates were investigated according to the types of prostatectomy, as well as according to prostate-specific antigen (PSA) levels upon diagnosis.;(Results) Positive surgical margin rates were 53.8% in the “not conducted” and “<1 month” groups, 38.8% in the “1-3 month” group, 32.4% in the “3-6 month” group, and 10.7% in the >6 month” group. Positive surgical margin rates after open surgery (antegrade and retrograde) tended to decrease when NHT durations were longer, while those after LRP tended to increase inversely. No correlation was observed between PSA levels upon diagnosis and positive surgical margin rates or between presurgical PSA levels and NHT durations.;(Conclusion) Positive surgical margin rates were not significantly different when patients were treated with NHT for 1-3 months, but they tended to decrease when NHT was for >6 months. However, positive surgical margin rates after LRP increased when NHT continued for longer periods of time. This may the result of fibrous adhesion in the vicinity of the prostate due to long-term NHT which made the surgical margins unclear.