Quantification of Three-Dimensional Cell-Mediated Collagen Remodeling Using Graph Theory

Background: Cell cooperation is a critical event during tissue development. We present the first precise metrics to quantify the interaction between mesenchymal stem cells (MSCs) and extra cellular matrix (ECM). In particular, we describe cooperative collagen alignment process with respect to the spatio-temporal organization and function of mesenchymal stem cells in three dimensions. Methodology/Principal Findings: We defined two precise metrics: Collagen Alignment Index and Cell Dissatisfaction Level, for quantitatively tracking type I collagen and fibrillogenesis remodeling by mesenchymal stem cells over time. Computation of these metrics was based on graph theory and vector calculus. The cells and their three dimensional type I collagen microenvironment were modeled by three dimensional cell-graphs and collagen fiber organization was calculated from gradient vectors. With the enhancement of mesenchymal stem cell differentiation, acceleration through different phases was quantitatively demonstrated. The phases were clustered in a statistically significant manner based on collagen organization, with late phases of remodeling by untreated cells clustering strongly with early phases of remodeling by differentiating cells. The experiments were repeated three times to conclude that the metrics could successfully identify critical phases of collagen remodeling that were dependent upon cooperativity within the cell population. Conclusions/Significance: Definition of early metrics that are able to predict long-term functionality by linking engineere

Polyorchidism: A Case Report and Review of the Literature

Polyorchidism is defined by the presence of more than two testicles. It is a very rare anomaly. In this paper, we report a case of polyorchidism that presented as a painless scrotal mass. Undrained types require histological evaluation. Increased risk of malignancy should be taken into consideration in patients with nonscrotal supernumerary testes. We did not recommend any treatment to our patients who had scrotal supernumerary testicle and two children and decided to follow-up with scrotal ultrasound