Search

We devised a new microfluorometric method for determining the ploidy of megakaryocytes identified immunologically in bone marrow smears. The smears were immunostained by incubation with mouse monoclonal anti-glycoproteins (GP) IIb antibodies, followed by fluorescein isothiocyanate-conjugated goat antimouse IgG antibodies. They were then stained with 4',6-diamidino-2-phenylindole (DAPI). Megakaryocytes were identified by their GPIIb immunofluorescence using a microfluorometer and, after the filters were changed, their DNA content was assayed by measuring the intensity of DAPI fluorescence. This intensity was shown to be proportional to the DNA content when the aperture of the objective lens was reduced. We compared these results with those obtained when megakaryocytes were identified morphologically, using DAPI staining after Wright-Giemsa destaining. In all 12 normal controls, the ploidy peaks were shown to be 16N by both methods, and the mean ploidy detected by the immunological method was only reduced 0.961 times relative to the estimate from the morphological method. In contrast, in eight myelodysplastic syndrome (MDS) patients, the ploidy peaks were either 8N or 4N and the mean was reduced by 0.906 times (P = 0.018). Thus we could immunologically identify small megakaryocytes which we could not identify morphologically. Therefore, this method is useful for measuring megakaryocytic ploidy, especially in the pathological megakaryocytes of MDS patients.

To evaluate the effect of granulocyte/colony-stimulating factor (G-CSF) on the onset of the adult respiratory distress syndrome (ARDS), we investigated whether the incidence of ARDS due to pulmonary infection differed between the G-CSF group which received chemotherapy with G-CSF and historical controls without G-CSF. We evaluated 132 patients with hematological malignancy in complete remission without any main organ dysfunction who had been treated between April 1983 and December 1997. We compared the incidence of ARDS due to pulmonary infection between those who received G-CSF and those who did not. There was no remarkable difference in the number of patients, gender, age, or distribution of primary diseases between the two groups. The intensity of chemotherapy was not considered to significantly differ between the two groups, though the chemotherapy regimens administered differed slightly. In the G-CSF group, the duration of neutropenia was significantly shorter and the frequency of documented infection was significantly decreased. We could not find any relationship between ARDS due to pulmonary infection and any anticancer agent or antibiotics. There was no relationship between the kind of G-CSF and the incidence of ARDS due to pulmonary infection (per chemotherapy session; p > 0.10, per case; p > 0.30, χ2 test). The incidence of ARDS due to pulmonary infection per chemotherapy session was 4.21%, and showed a higher tendency in the G-CSF group (p < 0.100, χ2 test). The incidence of ARDS due to pulmonary infection per case was 25.4% and was significantly higher in the G-CSF group (p < 0.025, χ2 test). The incidence of ARDS due to pulmonary infection was higher in the G-CSF group than in the controls, suggesting that G-CSF promotes the development of ARDS due to pulmonary infection.