Lymphoid Tumors in Amphibia: A Review1

Some Pathological Aspects of the Spontaneous Lymphoid Tumour in <i>Xenopus laevis</i>

“…The lymphoid tumour of Xenopus has been shown to be highly trans missible by tissue transplantation and cell-free extracts [Balls, 1964: Balls andR uben, 1968;H adji-A zimi andF ischberg, 1968, 1971;H adji-A z im i, 1970]. Balls and R uben [1968] have suggested a viral aetiology and the transmission of the infectious agent through the water in which the animals are kept.…”

“…Balls and R uben [1968] have suggested a viral aetiology and the transmission of the infectious agent through the water in which the animals are kept. Nevertheless, we have not observed an increase of spontaneous tumour incidence from 1964 to 1967.…”

“…Several characteristics of the tumour, such as its successful transmission by tissue transplantation and cell-free extracts and the occurrence of a serum disproteinemia in tumour-bearing animals have since been studied [Balls, 1964;Balls and R uben, 1968;H adji-A z im i, 1969, 1970H adji-A zimi and Fischberg, 1968]. It is the purpose of the present paper to report on the spontaneous incidence of this tumour in a laboratory colony of Xenopus laevis, as well as on some investigations on the development of the tumours and the fine structure of tumour cells in the liver and spleen.…”

Mycobacteria and Lymphoreticular Tumours in <i>Xenopus laevis, </i>the South African Clawed Toad

“…On the basis of experiments involving transmission by cell-free filtrates. Balls and Ruben [7] considered that the lymphoreticular lesions induced in the visceral organs of Xenopus laevis were malignant tumours, possibly induced by a virus. Inoue and Singer [19] re ported that spontaneously originating tumours in Trituruspvrrhogaster could be induced by mycobacteria isolated from them, by other species of myco bacteria.…”

“…D aw e [1113] considered that both the Xenopus and Triturus diseases were infectious granulomata induced by acid-fast bac teria. However, Balls and Ruben [7] argued that the mycobacteria some times found in advanced Xenopus tumour lesions were secondary residents rather than prime causes of the disease. Ruben and Stevens [23] suggested that mycobacterial granulomata were histologically distinguishable from the In the preceding paper [10] we described how Mycobacterium mar ¡mint was isolated from lymphoid tumour cells cultured from the liver of a Xenopus toadlet bearing advanced tumour lesions induced by the injection of cell-free tumour homogenate.…”