[A teaching medical simulator: phacoemulsification in virtual reality]. / Simulateur pédagogique médical: la phacoémulsification en réalité virtuelle.

INTRODUCTION: Improvements in computer technology have made it possible to design a cataract surgery teaching simulator in real time. MATERIAL AND METHODS: A computed representation of the lens was made with a mechanical model simulating the behavior of the lens, to which we added texture. The different models use mesh to make a section, which allowed us to make a section in real time using element removal or separation. Different models were used: a mass-spring mesh, a rigid model and a deformable model created using the finite element method. The contact with the lens is simulated by a collision sphere, which provides the interaction between the surgical instruments and the virtual environment. The surgical instruments viewed on the screen are controlled by a stylus with 6 degrees of freedom. DISCUSSION: We obtained the first step of phacoemulsification in real time with a good visual aspect. The surgeon views the procedure and can modify his movements instantaneously. This simulator provides the opportunity for students to safely learn phacoemulsification and improve their technique with an infinite number of procedures. CONCLUSION: The realism offered by this tool provides a rigorous teaching tool that might reduce the learning curve for phacoemulsification.

Epidermal and transforming growth factors modulate secretion of a 69 kDa phosphoprotein in normal rat kidney fibroblasts.

Our study shows that the secretion of a major non-glycosylated, phosphoprotein of 69 kDa (pp69) is a specific marker for non-transformed NRK-49F cells. Treatment of NRK-49F cells with EGF alone or with different combinations of EGF plus TGF-beta modulates the secretion of pp69, suggesting its relationship with cellular proliferation. Antibody raised against pp69 recognizes, in addition to pp69, another major phospho-protein of 62 kDa (pp62) secreted by RR1022 and spontaneously transformed NRK-49F cells. Immunoprecipitation of total cell lysates from both NRK-49F and RR1022 cells with anti-pp69 antibody detected only pp69. These observations suggest a precursor-product relationship between pp69 secreted by non-transformed NRK-49F cells and pp62 secreted by transformed cells.