Biomedical Engineering Reference
In-Depth Information
(Cooper, 2003). In 1781, the principle of regeneration as observed in
the freshwater
Hydra
was favourably compared to wound healing
and scar formation in humans, with the suggestion that this was a
structural property of the organism's self-organization (Cooper,
2003). It has also been suggested that this is the same principle of
self-organization found in Kantian philosophy and the distinction
between organic and machine causality (Cooper, 2003). The idea
that regeneration is an intrinsic capacity of the way that living
material is organized thus has a long scientific, philosophical and
conceptual lineage.
While some of the theoretical and conceptual ideas of adult stem
cell science can be traced back to the seventeenth and eighteenth
centuries, it was not until the late nineteenth century that a division
between generational material that might proliferate beyond an
individual organism and structural material that gave rise to
individuals was defined (Cooper, 2003). The distinction between
germ cells that divide continually and somatic cells that are finite
was introduced at this point, with germ cells being identified as
giving rise to all of the somatic cells of the body (Cooper, 2003).
Moreover, germ cells were also the cells responsible for the
transmission of inheritable traits, where any changes in characteristics
had to do with random mutations in the germ cells (Cooper, 2003).
Interestingly, the hypothesis was posed that each somatic cell
contained some fragments of the germ-plasm that served to direct
the growth and development of the somatic cells in which they were
found (Cooper, 2003). At the same time though, like the earlier
preformationists, the evidence of regeneration was still unaccounted
for and could not be reconciled through the distinction between
germ and somatic cells (Cooper, 2003). Nevertheless, these late
nineteenth-century experiments clearly show some of the developing
ideas that form the basis of contemporary stem cell biology.
4.1.1 Bonemarrowtransplants
While the theoretical development of embryology and contemporary
tissue culturing techniques set the stage for the later discovery and
