J. Robert Kent

The lipid‐bilayer component of cell membranes is an aqueous bimolecular aggregate characterized by a heterogeneous lateral organization of its molecular constituents. The heterogeneity may be sustained statically as well as dynamically. On the basis of recent experimental and theoretical progress in the study of the physical properties of lipid‐bilayer membranes, it is proposed that the dynamically heterogeneous membrane states are important for membrane functions such as transport of matter across the membrane and enzymatic activity. The heterogeneous membrane states undergo significant structural changes in response to changes in compositional, thermodynamic, and environmental conditions. The diverse effects of a variety of molecular Compounds interacting with membranes, such as Cholesterol and drugs like anaesthetics, may be understood in terms of the ability of these compounds to affect and modulate the dynamic membrane heterogeneity.

This paper identifies the legal and policy framework relating to the use of aborted fetuses in stem cell research and therapies and contrasts this with the collection of embryos for research. It suggests that more attention should be given to questions about the kind of consent sought by researchers from women and that there should be more transparency about how aborted fetuses are used. It reports on variability in current practices of research ethics committees and researchers and uncertainty about the guidance available to them. It argues that there is a need for wide public discussion about the policy issues relating to fetal tissue use in stem cell research and the need for clarification of the law in this area