U.S.-Korea economic relations

노트 : A publication of the Korea Economic Institute and the Korea Institute for International Economic Polic

Rapid casting of patterned vascular networks for perfusable engineered three-dimensional tissues

In the absence of perfusable vascular networks, three-dimensional (3D) engineered tissues densely populated with cells quickly develop a necrotic core. Yet the lack of a general approach to rapidly construct such networks remains a major challenge for 3D tissue culture. Here, we printed rigid 3D filament networks of carbohydrate glass, and used them as a cytocompatible sacrificial template in engineered tissues containing living cells to generate cylindrical networks that could be lined with endothelial cells and perfused with blood under high-pressure pulsatile flow. Because this simple vascular casting approach allows independent control of network geometry, endothelialization and extravascular tissue, it is compatible with a wide variety of cell types, synthetic and natural extracellular matrices, and crosslinking strategies. We also demonstrated that the perfused vascular channels sustained the metabolic function of primary rat hepatocytes in engineered tissue constructs that otherwise exhibited suppressed function in their core.National Institutes of Health (U.S.) (Grant EB00262)National Institutes of Health (U.S.) (Grant EB08396)National Institutes of Health (U.S.) (Grant GM74048)University of Pennsylvania (Center for Engineering Cells and Regeneration)American Heart Association (Jon Holden DeHaan Foundation)National Institutes of Health (U.S.). Ruth L. Kirschstein National Research Service Award (DK091007

Impact of Political Structures and Informal Political Processes on Health Policy: Comparison of the United States and Canadab

A number of factors, including cultural, social, economic, political, and historical, influence policy. United States and Canada's health care systems are the conscious and subconscious outcomes of formal political structures and informal political processes. The Canadian parliamentary political system encourages centralized, organized, planned policy in health care. However, this is accomplished at the risk of leaving some individuals-physicians in this case-quite frustrated. American constitutional features, the presidential system, weak political parties, and the tireless participation of interest groups in the political process all function to discourage the formation of highly rational and efficient policy. While few special interests are ever completely satisfied with the legislation produced, seldom is any organized group completely thwarted. Therefore, it is no surprise that a tightly integrated national program of universal health insurance was not adopted by Congress in 1993-1994. Political structures and processes discourage effective, comprehensive health care reform in the United States. Copyright 1994 by The Policy Studies Organization.