Aberrant megakaryocytopoiesis preceding radiation-induced leukemia in the dog. [Gamma radiation]
Six of nine decedent beagles exposed continuously to 2.5 R/22 hour day of whole-body /sup 60/Co ..gamma..-radiation died with myeloproliferative diseases: three cases of myelogenous leukemia and one each of monocytic leukemia, erythroleukemia, and erythremic myelosis. The three dogs that died with myelogenous leukemia had micromegakaryocytes and megakaryoblasts in the peripheral blood during the preleukemic phase when myeloblasts were not observed in the peripheral blood or in increased numbers in the bone marrow. In this study we have examined the megakaryocytes during the preleukemic period by a combination of light, transmission, and scanning electron microscopy. Morphologic abnormalities seen by light microscopy included mononucleated and binucleated forms, many with cytoplasmic blebs. The small mononuclear forms in the bone marrow tended to form clusters. Ultrastructural features included a paucity of both specific ..cap alpha.. granules and dense granules. The micromegakaryocytes showed dysgenesis of the demarcation membrane system. This membrane system appeared disorganized with a few dilated round, oval, or rarely, elongated vesicles and showed no evidence of platelet formation. The cells also had a paucity of endoplasmic reticulum, few mitochrondria, and sparse glycogen accumulations. The scarcity of cytoplasmic organelles gave a pale immature appearance to the cytoplasm. By scanning electron microscopy, the sponge-like surface of large mature megakaryocytes from unirradiated marrow contrasted with the characteristically smooth, topographically featureless surfaces of the micromegakaryocytes from preleukemic dogs.
- Research Organization:
- Argonne National Lab., IL
- DOE Contract Number:
- W-31-109-ENG-38
- OSTI ID:
- 5681928
- Journal Information:
- Scanning Electron Microsc.; (United States), Vol. 1
- Country of Publication:
- United States
- Language:
- English
Similar Records
Probable essential thrombocythemia in a dog
Therapy-related leukemia. A panmyelosis
Related Subjects
BEAGLES
WHOLE-BODY IRRADIATION
BONE MARROW
BIOLOGICAL RADIATION EFFECTS
LEUKEMIA
RADIOINDUCTION
BLOOD
BLOOD CELLS
COBALT 60
GAMMA RADIATION
OPTICAL MICROSCOPY
SCANNING ELECTRON MICROSCOPY
ULTRASTRUCTURAL CHANGES
ANIMAL TISSUES
ANIMALS
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
BIOLOGICAL EFFECTS
BIOLOGICAL MATERIALS
BODY
BODY FLUIDS
COBALT ISOTOPES
DISEASES
DOGS
ELECTROMAGNETIC RADIATION
ELECTRON MICROSCOPY
EXTERNAL IRRADIATION
HEMATOPOIETIC SYSTEM
HEMIC DISEASES
INTERMEDIATE MASS NUCLEI
INTERNAL CONVERSION RADIOISOTOPES
IONIZING RADIATIONS
IRRADIATION
ISOMERIC TRANSITION ISOTOPES
ISOTOPES
MAMMALS
MATERIALS
MICROSCOPY
MINUTES LIVING RADIOISOTOPES
MORPHOLOGICAL CHANGES
NEOPLASMS
NUCLEI
ODD-ODD NUCLEI
ORGANS
RADIATION EFFECTS
RADIATIONS
RADIOISOTOPES
TISSUES
VERTEBRATES
YEARS LIVING RADIOISOTOPES
560152* - Radiation Effects on Animals- Animals