Day 1 :
University College London, UK
Keynote: Bone graft substitute materials
Time : 10.00-10.30
Gordon Blunn is a Bio-Engineer at the Institute of Orthopedics and Musculoskeletal Science at University College London; he is based at the Royal National Orthopedic Hospital. He is currently the President of the British Orthopedic Research Society and holds the position of Chief Scientific Officer for Stanmore Implants Worldwide Ltd. and he is Co-Director of the London Implant Retrieval Centre (LIRC). He has extensive research experience in orthopedic medical devices, materials and musculoskeletal tissues and published over 150 papers in peer-reviewed journals; holds a number of patents on medical devices as well as being a Scientific Adviser to a number of SMEs.
With the growing number of surgical interventions for the treatment of bone defects Bone Graft Substitute Materials (BGSM) provide alternatives to Allograft and Auto-graft. In some circumstances BGSM may be mixed as an expander with Auto-graft materials. However, the use of Bone Graft Substitute’s means that donor site morbidity associated with obtaining Auto-graft does not occur. There are various types of BGSM; they can be divided into those which are based on calcium phosphates and those that associated with more organic materials such as De-mineralized Bone Matrix (DBM). There are many BGSM available for the surgeon to choose from. The compositions and structure of these bone graft materials are associated with the degree osteoconductivity and in some instances these bone graft materials have shown to be osseoinductive. The nature of this osseointegration will be explored.
Teikyo University School of Medicine, Japan
Keynote: Electron microscopic recording of ATP-induced myosin head power and recovery strokes in hydrated muscle myosin filaments using a film-sealed hydration chamber
Time : 10:30-11:00
Haruo Sugi was born in 1933 in Tokyo, and graduated from Postgraduate School of Life Sciences at the University of Tokyo with Ph.D. degree in 1962, and appointed to be Instructor in Physiology at the University of Tokyo. From 1965 to 1967, Sugi stayed in USA as a research associate at Columbia University and as a visiting scientist in NIH. In 1973, he became Professor and Chairman in the Department of Physiology, Teikyo University. From 1994 to 2006, Dr. Sugi was chairman of Muscle Commission in the International Union of Physiological Sciences. In 2004, he retired from his position in Teikyo University, and is now Emeritus Professor of Teikyo University.
Muscle is a machine converting chemical energy derived from ATP hydrolysis into mechanical work. Although it has been well established that muscle contraction is produced by relative sliding between actin and myosin filaments, which in turn is caused by repeated myosin head power and recovery strokes, Despite extensive studies over more than 20 years, the myosin head movement coupled with ATP hydrolysis still remains to be a matter for debate and speculation. As early as 1980s, we started to visualize ATP-induced myosin head movement in hydrated myosin filaments under a 200kV transmission electron microscope, using a film-sealed hydration chamber developed by Prof. Fukami in Nihon University. After a number of trials and errors, we have succeeded in recording ATP-induced myosin head movement, position-marked with antibodies to myosin heads, in both the absence and the presence of actin filaments with the following results: (1) Without ATP application, the time-averaged position of individual myosin heads do not change appreciably with time, suggesting that myosin heads undergo thermal fluctuation around a stable equilibrium position; (2) In the absence of actin filaments, individual myosin heads move freely (average amplitude, ~7nm) in response to iontophoretically applied ATP away from the bare region at the center of myosin filaments, indicating that the ATP-induced myosin head movement corresponds to myosin head recovery stroke; (3) In the presence of actin filaments, individual myosin heads move by ~3.3nm (average amplitude, ~3.3nm at the distal region and ~2.4nm at the proximal region) ; (4) The small amplitude of myosin head power stroke results from that only a small fraction of myosin heads are activated by ATP, so that individual myosin heads move for a limited distance by pulling adjacent elastic structures; (5) At low ionic strength, the amplitude of ATP-induced myosin head power stroke increased to >5nm in both distal and proximal regions, being consistent with our physiological finding that the force generated by individual myosin heads increases ~twofold. We emphasize that the film-sealed hydration chamber coupled with iontophoretic ATP application is a powerful tool in solving many mysteries in biological systems.