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Biomedical subjects

P R Daoust

Publications and source records attributed to P R Daoust.

7 recordsLinked to original sources
PubMed1994

Bone marrow necrosis in two patients with acute promyelocytic leukemia during treatment with all-trans retinoic acid.

All-trans retinoic acid has been used for the treatment of acute promyelocytic leukemia (APL) with encouraging results. However, it has recently been associated with a number of potentially serious complications including the retinoic acid syndrome. We describe two patients with APL who were begun on all-trans retinoic acid therapy (45 mg/m2), but who developed leukocytosis which was treated with hydroxyurea. Both patients demonstrated clinical and laboratory findings of disseminated intravascular coagulation, massive cell lysis manifested by marked increases in serum lactic dehydrogenase, and rapid clinical deterioration. Both patients developed bone marrow necrosis within viable, noninfarcted bone trabeculae. We postulate that the development of bone marrow necrosis in these two patients was not a chance occurrence. Rather, the specific combination of cytotoxic and differentiating agents used in these patients (hydroxyurea with all-trans retinoic acid) caused massive cell lysis and death. The absence of bone marrow necrosis in the setting of induction therapy for APL both with and without all-trans retinoic acid therapy suggests that the addition of hydroxyurea was critical to the development of marrow necrosis. We, therefore, recommend caution in the use of hydroxyurea and all-trans retinoic acid in the treatment of APL.

Adult↗
PubMed1983

Detecting infection-related changes in peripheral blood smears with image analysis techniques.

High-resolution image analysis has the potential to flag subtle changes in white blood cell morphology that may indicate the presence of certain diseases. A study was made of the feasibility of identifying patients with hematologic bacterial infections (sepsis) using measurements on Wright-Giemsa-stained peripheral blood smears. Neutrophils and lymphocytes from a group of patients with sepsis and from a control group were digitized, and parameters quantifying geometry, color, texture and shape were extracted. While color parameters differed the most between the infected and control samples, substantial differences in geometric, texture and shape parameters also were observed. Analysis of the data showed that individual neutrophils and lymphocytes from patients with sepsis were distinguishable from those of the control group with better than 84% accuracy. When average parameters were calculated from all cells of one type for each specimen, 100% accurate classification was obtained. These studies demonstrate that the image-analysis techniques used are sensitive enough to detect disease-related changes in cell morphology that are generally too subtle for reliable detection by the human eye. Future experiments will determine the specificity of this test for bacterial infections and will explore the possibility of using image analysis techniques on peripheral blood to detect and monitor a wide variety of diseases.

Cytodiagnosis↗
PubMed1983

Expression of multiple isozymes of granulocyte, monocyte, and macrophage esterases in polycythemic Friend erythroleukemia cells.

We examined the expression of cytochemical markers of myeloid and monocyte-macrophage differentiation in conjunction with ultrastructural studies of different malignant erythroleukemic cells isolated from mice infected with the Friend polycythemic virus complex (FLV-P). The amounts of fluoride-sensitive and resistant nonspecific esterase activity increased with the progression of malignancy. Isoelectric focusing resolved this enzyme activity into 13 isozymes in the most malignant Friend cell type tested. These same isozymes were found in the adherent cell population of normal spleens. Two of these isozymes were shown to have chloroacetate esterase activity characteristic of granulocytes. Despite these myeloid and monocyte characteristics, light and electron microscopy showed no morphological evidence of differentiation in either of these lineages. This study demonstrates that the Friend erythroleukemic cell contains markers of three different hemopoietic cell types. The expression of myeloid, monocytic, and erythroid traits in these erythroleukemic cells can be used to monitor their malignant progression.

Animals↗