This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Engle, G. C. Articles by Dutcher, R. M. Search for Related Content PubMed PubMed Citation Articles by Engle, G. C. Articles by Dutcher, R. M.

Preliminary Report on Virus-like Particles in a Transplantable Rat Mammary Carcinoma^1,2,

Institute for Medical Research, Camden, New Jersey 08103, and the School of Veterinary Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19348

Tumor, thymus, spleen, and plasma from rats inoculated with an X-irradiation-induced transplantable rat mammary carcinoma were examined with the electron microscope at various intervals following transplantation. Virus-like particles were found in all tumors at 15 or more days after transplantation but were not observed in the thymus, spleen and plasma, or in tumors examined earlier than 15 days. The particles were morphologically of the C-type, having a diameter of from 95 to 110 mµ. The significance of these virus-like particles and their relationship to the transplantable rat carcinoma is unknown.

¹ This work was supported in part by USPHS Postdoctoral Training Program 5T1-CA-5097 [G.C.O.], a Fellowship from the Leukemia Society of America [S. S.], and Contract PH 43-65-65 within the Special Virus Leukemia Program of the National Cancer Institute, NIH, USPHS [R. M. D.].

² Present address (all authors): Section of Viral Oncology, Leukemia Research Center, School of Veterinary Medicine, University of Pennsylvania, New Bolton Center, Kennett Square, Pennsylvania.

Received 1/ 9/68. Accepted 10/25/68.