Effect of Iron Chelators on Methemoglobin and Thrombin Preconditioning.

Cell loss immediately adjacent to an intracerebral hemorrhage may be mediated in part by the toxicities of extracellular hemoglobin (Hb) and thrombin. However, at low concentrations, these proteins induce tolerance to hemin and iron that may limit further peri-hematomal injury as erythrocyte lysis progresses. The mechanisms mediating these preconditioning effects have not been completely defined, but increased expression of both heme oxygenase (HO)-1 and iron binding proteins likely contributes. In the present study, we hypothesized that iron chelator therapy would attenuate this protective response. Pretreatment of cortical glial cultures (\u3e 90 % GFAP+) with 3 μM methemoglobin (metHb) or 5 units/ml thrombin for 24 h was nontoxic per se, and increased HO-1 and ferritin expression. When challenged with a toxic concentration of hemin, the increase in cellular redox-active iron was attenuated in preconditioned cultures and cell survival was increased. However, if cultures were pretreated with metHb or thrombin plus deferoxamine or 2,2\u27-bipyridyl, ferritin induction was prevented and cellular redox-active iron increased with hemin treatment. Preconditioning-mediated cytoprotection was consistently reduced by deferoxamine, while 2,2\u27-bipyridyl had a variable effect. Neither chelator altered HO-1 expression. A cytoprotective response was preserved when chelator therapy was limited to 11 hours of the 24 h preconditioning interval. These results suggest a potentially deleterious effect of continuous iron chelator therapy after ICH. Intermittent therapy may remove peri-hematomal iron without negating the benefits of exposure to low concentrations of Hb or thrombin

Multidisciplinary approach for developing a new minimally invasive surgical robot system

.Abstract – The synergy between fundamental science, engineering and medicine is constantly evolving while providing physicians with better tools and techniques for delivering patients effective health care. Minimally invasive surgery (MIS) revolutionized the way in which a number of surgical procedures are performed resulting in quicker postoperative recovery times. Surgical robotics provides a new paradigm to further improve MIS interventions. As part of an extensive experimental protocol, the kinematics and the dynamics of MIS tools were acquired from 30 surgeons who performed seven different minimally invasive surgical tasks. These tasks included tissue manipulation, tissue dissection and suturing in-vivo while using the Blue Dragon system and a porcine model. This database served as a design specification for a kinematic optimization of a spherical surgical robotic manipulator. Following the optimization that determined key geometrical dimensions of the robot, a 7-DOF cable-actuated surgical manipulator was designed and integrated, providing all the degrees of freedom of manual MIS as well as wrist joints located at the surgical end-effector. The surgical robotic system is teleoperated utilizing a single bi-directional UDP socket via a remote master device. This multidisciplinary approach of designing and optimizing the surgical robotic system will lead to a seamless integration into the operating room of the future. Index Terms – Surgical Robot, spherical, teleoperation, telesurger