1.
I N T R O D U C T I O N
7
this apparatus has since been adapted and adopted far and wide for
many sorts of investigation, and not only those within the narrow confines of actual tissue culture.
Again, for reasons of good visibility and accessibility, cells in tissue
culture could readily be subjected to various forms of radiation and
this approach was extensively developed at this time. The early results
of Roffo (1925), Canti (1926, 1928, 1930), Strangeways (1922, 1926),
Spear and others have since proved to have been of immense value not
only in providing a basis for the treatment of malignant growths by
radiation but also as a tool for research into nuclear structure and
function. Similar methods with ultraviolet radiation have now been so
far refined that it is possible to irradiate and damage defined areas of
particular chromosomes (Uretz, Bloom and Zirkle, 1954). The important practical aspect of this work of course depends upon the
peculiar susceptibility of growing cells to doses of radiation which
leave other cells relatively unaffected.
During the early 1930's, tissue culture and organ culture went on
in a rather undistinguished and largely descriptive manner. Steady
progress was nevertheless made in the studies of growth, the metabolism
of growing cells and of differentiation. Notable controversies arose over
the potentialities of lymphocytes and monocytes and whether or not
fibroblasts could become macrophages and vice versa. Fibre formation
by the various constituents of connective tissue was another controversial subject.
Some considerable excitement was created in 1938 when Carrel and
Lindbergh, the latter of solo-Atlantic-flight fame, devised an elaborate
pumping system for the intermittent or pulsating perfusion of whole
organs with oxygenated serum or other biological fluids. The complexities of the system were, however, such as to limit its use very
severely and the results achieved were not commensurate with the
efforts expended. Both before and after that time, many other perfusion
systems have been devised but they have mostly been attempted on a
much more modest scale. The first was probably that used by Burrows
as early as 1912. Their potential advantages are immediately obvious;
their disadvantages generally become evident only when the systems
are tested in practice. Indeed, they engender a healthy respect for the
circulatory system of the mammalian body! The use of antibiotics,
dating in tissue cultures from about 1940, does, however, simplify many
of the problems which result from using either large volumes of fluid or
fluid in contact with large surface-areas of apparatus. They do not,
however, contribute anything towards a remedy for the other main
defect inherent in any perfusion system, namely that of leaching out
important constituents from the tissues being perfused.
I N T R O D U C T I O N
7
this apparatus has since been adapted and adopted far and wide for
many sorts of investigation, and not only those within the narrow confines of actual tissue culture.
Again, for reasons of good visibility and accessibility, cells in tissue
culture could readily be subjected to various forms of radiation and
this approach was extensively developed at this time. The early results
of Roffo (1925), Canti (1926, 1928, 1930), Strangeways (1922, 1926),
Spear and others have since proved to have been of immense value not
only in providing a basis for the treatment of malignant growths by
radiation but also as a tool for research into nuclear structure and
function. Similar methods with ultraviolet radiation have now been so
far refined that it is possible to irradiate and damage defined areas of
particular chromosomes (Uretz, Bloom and Zirkle, 1954). The important practical aspect of this work of course depends upon the
peculiar susceptibility of growing cells to doses of radiation which
leave other cells relatively unaffected.
During the early 1930's, tissue culture and organ culture went on
in a rather undistinguished and largely descriptive manner. Steady
progress was nevertheless made in the studies of growth, the metabolism
of growing cells and of differentiation. Notable controversies arose over
the potentialities of lymphocytes and monocytes and whether or not
fibroblasts could become macrophages and vice versa. Fibre formation
by the various constituents of connective tissue was another controversial subject.
Some considerable excitement was created in 1938 when Carrel and
Lindbergh, the latter of solo-Atlantic-flight fame, devised an elaborate
pumping system for the intermittent or pulsating perfusion of whole
organs with oxygenated serum or other biological fluids. The complexities of the system were, however, such as to limit its use very
severely and the results achieved were not commensurate with the
efforts expended. Both before and after that time, many other perfusion
systems have been devised but they have mostly been attempted on a
much more modest scale. The first was probably that used by Burrows
as early as 1912. Their potential advantages are immediately obvious;
their disadvantages generally become evident only when the systems
are tested in practice. Indeed, they engender a healthy respect for the
circulatory system of the mammalian body! The use of antibiotics,
dating in tissue cultures from about 1940, does, however, simplify many
of the problems which result from using either large volumes of fluid or
fluid in contact with large surface-areas of apparatus. They do not,
however, contribute anything towards a remedy for the other main
defect inherent in any perfusion system, namely that of leaching out
important constituents from the tissues being perfused.