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PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1
pubmed:dateCreated
1992-5-7
pubmed:abstractText
Eleven 6-month-old calves were tsetse fly challenged with a stock of Trypanosoma vivax (IL 2337) that causes hemorrhagic infection. The calves were randomly euthanatized every 4 to 6 days; two other calves served as controls. Peripheral blood changes included anemia, thrombocytopenia, and an initial leukopenia. Later in the course of infection, leukocytosis associated with lymphocytosis and neutropenia developed. Moderate reticulocytosis (highest mean count 3.6 +/- 3.7%, maximum count 9.4%) accompanied the first wave of parasitemia, but poor response (highest mean 0.4 +/- 0.0%) occurred during the second wave, despite the persistence of severe anemia. Light microscopic examination of bone marrow samples showed a drop in the myeloid: erythroid ratio with a decrease in granulocytes, particularly metamyelocytes, bands, and segmenters. Increase in lymphocyte counts corresponded with the appearance of lymphoid nodules within the marrow. Megakaryocytic volume increased significantly in infected animals, and some megakaryocytes showed emperipolesis of red cells, neutrophils, and lymphocytes. Transmission electron microscopic examination of the bone marrow revealed that trypanosomes had crossed the sinusoidal endothelium into the hematopoietic compartment as early as the second day of parasitemia. Macrophages proliferated in the bone marrow; and from the second day of parasitemia until the end of the experimental infection, on day 46, the macrophages had phagocytosed normoblasts, eosinophil and neutrophil myelocytes, metamyelocytes, bands, and segmenters, as well as reticulocytes, erythrocytes, and thrombocytes. Therefore, dyserythropoiesis and dysgranulocytopoiesis were responsible, in part, for the observed anemia and granulocytopenia, respectively.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:status
MEDLINE
pubmed:month
Jan
pubmed:issn
0300-9858
pubmed:author
pubmed:issnType
Print
pubmed:volume
29
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
33-45
pubmed:dateRevised
2003-11-14
pubmed:meshHeading
pubmed:year
1992
pubmed:articleTitle
A light and electron microscopic study of changes in blood and bone marrow in acute hemorrhagic Trypanosoma vivax infection in calves.
pubmed:affiliation
International Laboratory for Research on Animal Diseases, Nairobi, Kenya.
pubmed:publicationType
Journal Article