Environmental Carcinogenesis Studies in Fishes of the Great Lakes of North America*

Effect of polychlorinated biphenyls (Delor 103) on haematological and enzyme parameters of the rainbow trout Oncorhynchus mykiss

“…This is indicated by the results from our fish health monitoring surveys continued for several years in water-source reservoirs (Ř ehulka 2001, 2002a) with descriptions of cholangiofibrosis, cholangiocellular carcinoma and Sertoli cell adenoma. According to Sonstegard (1977), PCBs and/ or DDT may be involved in the aetiology of the gonadal tumour. In addition, symptoms of genotoxic damage (micronucleus) and the erythrocyte nuclear lesions observed in the fish in the reservoirs also encouraged us to carry out trials aimed at evaluating the effect of intraperitoneal administration of Delor 103 on the state of rainbow trout health.…”

Ultrastructure of malpighian and inflammatory cells in epidermal papillomas of white suckers Catostomus commersoni

“…Epidermal papillomas affect brown bullheads Ictalurus nebulosus and white suckers Catostomus commersoni in unpolluted but particularly in polluted areas of the Great Lakes of North America; these papillomas are similar in structure to the papillomas contain- ing virus particles in other species (Smith & Ferguson 1985, Smith & Zajdlik 1987. Papillomas affecting white suckers are reported to contain C-type virus particles and reverse-transcriptase (Sonstegard 1977), but this observation is not well supported. White suckers kept in laboratory tanks for 3 mo after spawning developed new papillomas in the apparent absence of pollution (Smith & Zajdlik 1987) suggesting viruses or other unknown factors are capable of causing these neoplasms.…”

“…Epidermal papillomas in many species often contain intra-or extra-cellular viral particles (Pilcher & Fryer 1980, McAllister et al 1985, Bloch et al 1986). Papillomas of white suckers have been reported to contain C-type virus particles and reserve-transcriptase (Sonstegard 1977), and that papillomas develop on white suckers kept in the laboratory (Smith & Zajdlik 1987) further suggests that viruses are possible etiologic agents for these tumors. While not directly correlated with reported regression tendencies inflammation, cellmediated immunity and abnormal cell-cell communication identified in these papillomas likely play a role in their persistence and morphology.…”

Carcinogens and Cancers in Freshwater Fishes

“…No viruses were detcted in subsequent ultrastructures studies conducted by Smith et al (30). The development ofthese neoplasms may also be influenced by pollution, since the frequency of occurrence increases dramatically from a low ofaround 6% in the eastern basin, to a high of 39% in the western part of the basin near the Oakville-Burlington, Ontario, Canada, area (27).…”

“…On the basis ofa report by Sonstegard (27) of C-type virus particles observed by electron microscopy and tissue fractions contining reverse transcriptase activity, this neoplasm was suspected to have a viral etiology. No viruses were detcted in subsequent ultrastructures studies conducted by Smith et al (30).…”