166
LIOB EL E. MAWDESLEY-THOMAS
significant contribution to medical science. As already mentioned, the
term “neoplasm” is really a synonym for an unknown or as yet
unappreciated aetiology, while various aetiologies have been associated
with neoplastic transformation. In the fullness of time all aetiologies
may be appreciated and the term “ neoplastic ” will pass out of our
language. The study of fish tumours can often shed much information
by using relatively unsophisticated epidemiological methods to point to
a common aetiology, and there are already examples of this which will be
considered lator. Factors of human ttppliciition and significance may bc
established by the study of fish tumours in relation to their geographical
distribution, their various phylogenetic, including immunological and
enzymatic, entities, together with the part played by pollution, trauma
and oncogenic viruses. The liver cell of some members of the Ralmonidae
is the most sensitive histological indication that exists for the bioassay
of aflatoxin B;. Stanton (1965) stated that “ The high sensitivity of
small fish to a known carcinogen, their poikilothermic physiology and
the ease with which their aquatic environment can be controlled are
particular advantages in studies on carcinogenesis.” The sooner the
cancer research worker realizes that there are animals other than rats
and mice, the better!
Harshbarger (1972) was the first to record an olfactory neuroepithelioma in Coregonus hoyi (Gill, 1862), a freshwat er fish, while the documentation of a neural tumour in ih marine fish is still awaited. This remains
the only mention of a CNS tumoiir in Pisces, excluding the neurilemmomata. The central nervous system of the poikilothermic vertebrate
has still retained its fundarnen tal ability to undergo reparative processw,
which in relation to man represents a peculiar. phylogenic phenomenon.
The process in fish is at prcverit being studied (Mawdedey-Thomm el a!.,
in preparation 1974).
Epidemiological studies in animals and man have shown that there
is often a geographical distribution of certain diseases, and appreciation
of this fact may help to establish the aetiological agent. Examples in
man include the high incidence of liver cell tumours in the Bantu, and
Burkett’s lymphoma in certain parts of Central Africa. One cannot help
but wonder if the lympho-sarcomata in fish, E.s+ox lucius (Linnaeus 1758)
reported by Mulcahy (1970), Marek’s disease of poultry and Burkett’s
lymphoma in man might not have a common aetiology, but present with
different signs according to the species in which they are found. Other
examples of pathological geography in Pisces are well documented. The
papillomata of the Pleuronectidne off the American West Coast (Dawe
and Harshbarger, 1969) and the stomato-papillomatosis men in the
Anguillidae in the North and Baltic: Soils (I)cys, 1969) baing but two.
LIOB EL E. MAWDESLEY-THOMAS
significant contribution to medical science. As already mentioned, the
term “neoplasm” is really a synonym for an unknown or as yet
unappreciated aetiology, while various aetiologies have been associated
with neoplastic transformation. In the fullness of time all aetiologies
may be appreciated and the term “ neoplastic ” will pass out of our
language. The study of fish tumours can often shed much information
by using relatively unsophisticated epidemiological methods to point to
a common aetiology, and there are already examples of this which will be
considered lator. Factors of human ttppliciition and significance may bc
established by the study of fish tumours in relation to their geographical
distribution, their various phylogenetic, including immunological and
enzymatic, entities, together with the part played by pollution, trauma
and oncogenic viruses. The liver cell of some members of the Ralmonidae
is the most sensitive histological indication that exists for the bioassay
of aflatoxin B;. Stanton (1965) stated that “ The high sensitivity of
small fish to a known carcinogen, their poikilothermic physiology and
the ease with which their aquatic environment can be controlled are
particular advantages in studies on carcinogenesis.” The sooner the
cancer research worker realizes that there are animals other than rats
and mice, the better!
Harshbarger (1972) was the first to record an olfactory neuroepithelioma in Coregonus hoyi (Gill, 1862), a freshwat er fish, while the documentation of a neural tumour in ih marine fish is still awaited. This remains
the only mention of a CNS tumoiir in Pisces, excluding the neurilemmomata. The central nervous system of the poikilothermic vertebrate
has still retained its fundarnen tal ability to undergo reparative processw,
which in relation to man represents a peculiar. phylogenic phenomenon.
The process in fish is at prcverit being studied (Mawdedey-Thomm el a!.,
in preparation 1974).
Epidemiological studies in animals and man have shown that there
is often a geographical distribution of certain diseases, and appreciation
of this fact may help to establish the aetiological agent. Examples in
man include the high incidence of liver cell tumours in the Bantu, and
Burkett’s lymphoma in certain parts of Central Africa. One cannot help
but wonder if the lympho-sarcomata in fish, E.s+ox lucius (Linnaeus 1758)
reported by Mulcahy (1970), Marek’s disease of poultry and Burkett’s
lymphoma in man might not have a common aetiology, but present with
different signs according to the species in which they are found. Other
examples of pathological geography in Pisces are well documented. The
papillomata of the Pleuronectidne off the American West Coast (Dawe
and Harshbarger, 1969) and the stomato-papillomatosis men in the
Anguillidae in the North and Baltic: Soils (I)cys, 1969) baing but two.