Plenary Speakers

Date: Wednesday, 3 December 2008
Time: 09:30 - 10:00 hrs
Venue: Level 2, Theatre

Prof George RADDA
Chairman
Singapore Bioimaging Consortium, A*STAR
Title: Imaging Molecules in vivo in Medical Research

Molecular imaging is a set of emerging technologies at the life science/physical science interface which is set to revolutionize our understanding and treatment of disease. The term molecular imaging is used in a variety of ways and includes imaging or observing specific molecules which are present in living systems, the use of externally added reporter molecules or signals that can be activated by a particular process such as gene expression. Molecular imaging techniques span the electromagnetic spectrum from ultrasonic to gamma ray and X-ray frequencies. Within this spectrum Magnetic Resonance (Imaging and Spectroscopy), optical imaging and nuclear imaging are the key ways of observing molecular event and interactions in living systems, including man.

To answer a significant biological or clinical question we need to select the most appropriate technique, often requiring the combination of more than one method, use chemical and biological approaches to design and evaluate specific imaging probes and develop advanced computational techniques for analyzing the images and interpreting the information.

In this presentation I shall illustrate the use of Magnetic Resonance Spectroscopy (MRS) and Imaging (MRI) to study heart disease, of optical and MR imaging to study, observe and quantify the release of insulin from pancreatic beta-cells in models for diabetes and describe how a new approach for the design of fluorescent and other probes can be used for detecting a variety of targets in vivo.

The Laboratories of the Singapore Bioimaging Consortium developed an integrated research programme on molecular regulation of hormone secretion and signalling, on the role of glucose and lipid metabolism in the metabolic syndrome and the translation of pre-clinical probe development and imaging technologies for clinical investigations at the newly established A*-STAR/NUS Clinical Imaging Research Centre. Molecular imaging is a key tool in the translation of basic and pre-clinical research findings to clinical situations aimed at leading to the improvement of human health.


Date: Thursday, 4 December 2008
Time: 09:00 - 09:30 hrs
Venue: Level 2, Theatre

Prof Shu CHIEN
Professor
University of California, San Diego
Title: Molecular and Mechanical Bases of Endothelial Adaptation to Flow

Mechanical forces, including the shear stress resulting from blood flow and the circumferential stretch due to transmural pressure, can modulate the functions of vascular endothelial cells (ECs) by activating sequentially the mechano-sensors, signaling pathways, and gene and protein expressions. Laminar or pulsatile shear stress with a significant forward direction causes a transient activation of expression of pro-inflammatory and pro-proliferative genes such as MCP-1 followed by their down-regulation; shear flows with a significant forward direction also activate growth arrest genes. Thus, flow patterns with a significant forward component are anti-atherogenic. In contrast, the disturbed flow seen at curved regions and branch points of the arterial tree in vivo or reciprocating flow in vitro without a significant net forward direction causes the continued activation of chemoattractants (e.g., MCP-1) and a higher rate of cell proliferation, in comparison to the values seen under sustained laminar or pulsatile flow. Thus, flow patterns without a significant forward component are atherogenic. ECs respond differentially to uniaxial and biaxial stretches. Uniaxial stretch with a clear direction causes a Rho-dependent orientation of actin stress fibers perpendicular to the direction of stretch. In contrast, biaxial stretch without a defined direction does not cause any orientation of stress fibers. Uniaxial stretch causes transient JNK activation to inhibit EC proliferation and protect ECs against apoptosis. In contrast, biaxial stretch causes sustained JNK activation that leads to EC apoptosis. These findings indicate that the temporal and spatial variations in shear stress and stretch, especially the presence or absence of directionality, result in differential modulations of signal transduction, gene expression, and protein expressions, as well as EC functions and vascular biology. Interdisciplinary studies at the interface of biology, medicine and engineering serve to elucidate the mechanisms of mechanotransduction in various physiological and pathophysiological conditions in health and disease.


Date: Friday, 5 December 2008
Time: 09:00 - 09:30 hrs
Venue: Level 2, Theatre

Prof Toshiyo TAMURA
Professor & Director
National Institute for Longevity Science
Title: Gerontechnology to Improve the Quality Of Life

In the elderly society, the prediction and prevention of diseases are very important. Long term health care is one of the candidates to predict and find deceases. We have developed home health care system with new sensor system included interface for home health appliance. Each home has a server to collect the data from home health appliance. The data are transmitted to the central server to create the database and give any suggestions and recommendation to improve the quality of life (QOL). We have collected two years data and tried to create the algorithms to improve the quality of life. A typical example of changes in body weight gives the index of daily activity in the elderly..Furthermore, once elderly take a disease or decreased their physical and psychological activities, the assistive devices such s fall prevention system and memory aids are helpful. We propose few assistive devices which have been developed in our laboratory.


Date: Saturday, 6 December 2008
Time: 09:00 - 09:30 hrs
Venue: Level 2, Theatre

Prof Takuji ISHIKAWA
Professor
Tohoku University
Title: Biomechanics of a Suspension of Micro-Organisms

Micro-organisms play a vital role in many biological and medical phenomena; such as plankton blooms in the oceans that affect the oceanic ecosystem, bioreactors for medicine or food, human digestion assisted by enterobacteria. It is known that systems of swimming micro-organisms exhibit an interesting variety of collective behaviour such as clustering and migration; examples include coherent structures of swimming bacteria. The mechanism of these collective behaviours is still not well understood, and currently one of the most active research areas in biophysics. In this lecture, I will explain how swimming micro-organisms, such as Paramecia, Volvox and bacteria, interact in a suspension, and how the interaction can be modelled computationally. I will also explain how the suspension properties, such as the rheology and the diffusion, are affected by the interactions of micro-organisms. Interestingly, the simulation results illustrate that various coherent structures, such as aggregation, meso-scale spatiotemporal motion and band formation, can be generated by purely hydrodynamic interactions between micro-organisms.