The incidence of regression of wing-web tumors induced by Rous sarcoma virus was shown to be dependent on the quantity of thymus tissue remaining after neonatal thymectomy in chickens of inbred line 6. Frequency of metastasis was associated negatively with the amount of thymus tissue present. Tumor regression and metastasis restriction both appeared dependent on the quantity of thymic tissue present.

Animals↗

PubMedDate not supplied

The cyto-histopathology of a pseudomesotheliomatous carcinoma of the lung.

A cyto-histopathologic study of a pseudomesotheliomatous carcinoma of the lung has been presented. The cytologic preparations of the early morning and post-bronchoscopy sputum specimens, bronchial washings and pleural fluid contained tumor cells similar to those exfoliated from a terminal bronchiolar carcinoma, of which this neoplasm is considered a variant.

Adenocarcinoma↗

PubMedDate not supplied

A non-MHC genetic influence on response to Rous sarcoma virus-induced tumors in chickens.

Avian-leukosis-free females from Regional Poultry Research Laboratory (RPRL) inbred lines 6(1) and 7(2) were inseminated with pooled semen from RPRL line 15I5 males. The progeny resulting from the two crosses 15I5 X 6(1) and 15I5 X 7(2) were of the B2/B15 major histocompatibility complex (MHC) genotype, the B2 haplotypes from lines 6(1) and 7(2) being indistinguishable. When challenged with Rous sarcoma virus (RSV) at 6 weeks of age, 30 out of 31 progeny of cross 15I5 X 6(1) developed tumors that rapidly regressed, whereas 26 of 29 progeny of cross 15I5 X 7(2) died with progressive tumor growth. On the other hand, 15 of 18 B2/B15 segregants from the three-way cross (15I5 X 6(3]F1 X 7(2), identical in source to the MHC of the (15I5 X 7(2]F1 progressors, were characterized by tumor regression. Thus influences associated with non-MHC background genes from lines 6(1), 6(3), and 7(2) appeared to be critical to host response to RSV-induced sarcomas. Similar findings suggesting a strong non-MHC influence on anti-sarcoma response were obtained using 107 F2 and 77 backcross progeny of RPRL line 100 and noninbred University of New Hampshire (UNH) line 105. The B2 haplotype of line 100 was associated with tumor regression when combined with the line 105 background and with tumor progression when expressed on the line 100 background. Suppression of the anti-tumor response associated with line 100 appeared to be fairly generalized, since a poor response to tumor was observed regardless of which of three subgroups of RSV was used to induce tumor.

Animals↗