16 
Monitoring Stem Cell Research 
stem cells have their apparently beneficial effects on heart dis- 
ease when the cells are extracted from a cardiac patient’s 
bone marrow or muscle, expanded in culture, and injected into 
the patient’s heart? Or what is responsible for the positive ef- 
fects on a Parkinson Disease patient when cells from his own 
brain are similarly extracted, treated, and re-injected? We do 
not yet really know precisely what stem cell-based prepara- 
tions do when put into the body. 
At the same time, all discussion in this area suffers from a 
persistent background tension. The stakes are high, or seem 
so, to many of the discussants, and there is much politicking 
involved. As noted earlier, opponents of embryo research try to 
tout the virtues of adult stem cells, because they regard their 
use as a morally permissible alternative. Proponents, for their 
part, often find it tempting to disparage or downplay all adult 
stem cell studies and to emphasize instead what they believe 
to be the superior potential of embryonic stem cells for suc- 
cessful future therapeutic use. Navigating between these ten- 
dencies in search of the full truth can be daunting, and few 
people are altogether immune to the partial but seductive calls 
from the scientific or moral side they prefer. 
Yet without denying our individual differences on the ethi- 
cal and policy questions at issue, the Council has sought in 
this monitoring report to present a fair-minded and thorough 
overview, both of the ethical and policy debates and of the sci- 
entific and medical results to date. To aid us in our task of 
monitoring, we have commissioned six review articles and 
heard several oral presentations on the state of research, cov- 
ering studies using embryonic and studies using adult stem 
cells. We have commissioned a review article and heard a 
presentation on the problem of immime rejection, a potential 
major stumbling block to effective cell transplantation thera- 
pies. 
We have read papers, commissioned writings, heard pres- 
entations, and debated among ourselves about the various 
ethical and philosophical issues involved, from "the moral 
status of the embryo,’’ to the existence of a moral imperative to 
do research, to the meaning of federal fimding of morally con- 
troversial activities. We have read and heard public testimony 
PRE -PUBLICATION VERSION 
