strontium-radioisotopes and Primary-Myelofibrosis

Biochemical and morphological evidence indicates that a type-C retrovirus is present in the blood of swine (both leukemic and nonleukemic) exposed to strontium-90 radiation. Nonexposed swine that were leukemic also had virus present. The virus was shown to contain an RNase-sensitive DNA polymerase activity with cation, detergent and template requirements similar to those of known viral reverse transcriptases. The buoyant density of the virus was 1.14 to 1.16 g/ml, which can be converted, by treatment with ether, to a virion core having a density of 1.20 to 1.23 g/ml. Linear regression analysis indicated a correlation between virus-associated DNA polymerase activity and the number of blast cells in the peripheral blood.

Topics: Animals; Female; Leukemia, Radiation-Induced; Neoplasms, Radiation-Induced; Primary Myelofibrosis; Retroviridae; RNA-Directed DNA Polymerase; Strontium Radioisotopes; Swine; Swine, Miniature; Viral Proteins; Virus Activation

Cloned cell lines were established from two swine with radiation-induced myeloproliferative disorders, including one cell culture from an animal with myelogenous leukemia and one from an animal with myeloid metaplasia. A third cloned cell line with similar morphology was established from pooled normal fetal swine cornea to compare the growth characteristics of cells from normal and irradiated swine. All three cell lines grew as foci of aggregated cells and were able to form macroscopic colonies in semisolid agar medium. The lack of normal mechanisms of contact inhibition and the observed aneuploidy indicated that these cells were morphologically transformed. Further, the cloned cells caused tumors in nude mice, clearly indicating that these cells were also malignantly transformed. A major difference between these cell lines was that type C viruses were observed only in the cells derived from swine with myeloproliferative disorders.

Topics: Animals; Cell Division; Cell Line; Cell Transformation, Neoplastic; Clone Cells; Cornea; Karyotyping; Leukemia, Myeloid; Leukemia, Radiation-Induced; Mice; Neoplasms, Experimental; Primary Myelofibrosis; Radiation Injuries, Experimental; Strontium Radioisotopes; Swine

Topics: Animals; Antibody Formation; Basophils; Bone Marrow; Hematopoietic Stem Cells; Leukemia, Myeloid; Leukemia, Myeloid, Acute; Leukemia, Radiation-Induced; Lymphoma; Primary Myelofibrosis; Radiation Effects; Strontium Radioisotopes; Swine; Swine Diseases