Age-Related Adaptation of Bone-PDL-Tooth Complex: Rattus-Norvegicus as a Model System

Functional loads on an organ induce tissue adaptations by converting mechanical energy into chemical energy at a cell-level. The transducing capacity of cells alters physico-chemical properties of tissues, developing a positive feedback commonly recognized as the form-function relationship. In this study, organ and tissue adaptations were mapped in the bone-tooth complex by identifying and correlating biomolecular expressions to physico-chemical properties in rats from 1.5 to 15 months. However, future research using hard and soft chow over relevant age groups would decouple the function related effects from aging affects. Progressive curvature in the distal root with increased root resorption was observed using micro X-ray computed tomography. Resorption was correlated to the increased activity of multinucleated osteoclasts on the distal side of the molars until 6 months using tartrate resistant acid phosphatase (TRAP). Interestingly, mononucleated TRAP positive cells within PDL vasculature were observed in older rats. Higher levels of glycosaminoglycans were identified at PDL-bone and PDL-cementum entheses using alcian blue stain. Decreasing biochemical gradients from coronal to apical zones, specifically biomolecules that can induce osteogenic (biglycan) and fibrogenic (fibromodulin, decorin) phenotypes, and PDL-specific negative regulator of mineralization (asporin) were observed using immunohistochemistry. Heterogeneous distribution of Ca and P in alveolar bone, and relatively lower contents at the entheses, were observed using energy dispersive X-ray analysis. No correlation between age and microhardness of alveolar bone (0.7±0.1 to 0.9±0.2 GPa) and cementum (0.6±0.1 to 0.8±0.3 GPa) was observed using a microindenter. However, hardness of cementum and alveolar bone at any given age were significantly different (P<0.05). These observations should be taken into account as baseline parameters, during development (1.5 to 4 months), growth (4 to 10 months), followed by a senescent phase (10 to 15 months), from which deviations due to experimentally induced perturbations can be effectively investigated

Reproductive organ sparing cystectomy in women significantly improves continence after orthotopic bladder substitution without affecting oncological outcome

OBJECTIVES: To compare functional and oncological outcomes of reproductive organ-sparing cystectomy (ROSC) compared with standard cystectomy (SC) in women undergoing orthotopic bladder substitution (OBS). PATIENTS AND METHODS: Between 1995 and 2016, 121 consecutive women undergoing OBS were prospectively included in this single-centre non-randomized clinical follow-up study comprising an ROSC and an SC group. Urinary continence, the need for intermittent self-catheterization (ISC), lateral standing micturition cystourethrogram (MCUG), urethral pressure profile findings, if available, and oncological outcomes were assessed and compared between ROSC and SC. RESULTS: After 12 months, patients who had undergone ROSC with OBS had significantly higher daytime and nighttime continence rates than patients who had undergone SC with OBS (87.5% vs 63.5%; P = 0.027 and 87.5% vs 57.7%; P = 0.008), whereas no significant differences were found between groups in ISC rates (12.5% vs 12.94%; P > 0.99). The degree of attempted nerve-sparing (none, unilateral, bilateral) positively affected continence rates in both groups. No significant differences were found in local recurrence rates (0% vs 9.4%; P = 0.126), 5- and 10-year overall survival rates (80.9% and 80.9% vs 64.9% and 55.7%; P = 0.443) or 5- and 10-year cancer-specific survival rates (84.3% and 84.3% vs 73% and 66.2%; P = 0.431). CONCLUSION: Superior continence rates were found for ROSC with an OBS compared with SC, without a negative impact on oncological outcome. ROSC should, therefore, be offered to women receiving an OBS whenever justifiable