A mouse model of myelofibrosis induced by high dose of recombinant human erythropoietin / 中国实验血液学杂志

Tn order to set up a mouse model of myelofibrosis (MF) induced with high dose recombinant human erythropoietin (rhEPO). 60 mice were collected and divided into EPO and control groups, the former was injected with rhEPO and the latter with normal saline intraperitoneally. 5 mice from each group were executed on day 6, 30, 60, 90, 120 and 150 respectively. Their WBC count, Hb level, MCV, RDW and platelet amount were measured by automatic blood cell analyzer; CD34(+) cell ratio in bone marrow were analyzed by flow cytometry; liver and spleen coefficients were measured; pathological changes of liver, spleen, femur were observed by HE staining and reticular fibers staining; cortex thickness, femoral canal diameter and lumbar spine density were determined by computerized tomography (CT). The results indicated that as compared with normal control group in EPO induced group, WBC count was increased slightly in whole period, but without statistic significance (p > 0.05), Hb level and RDW increased at day 6 and 30 significantly (p < 0.05), MCV increased at day 6 significantly (p < 0.05), but platelet amount decreased significantly at all time points (p < 0.05). Most mice in EPO-induced group had hepatomegalia and their liver and spleen coefficient increased significantly at day 60 (p < 0.05), while most mice had splenomegaly and its coefficient was increased significantly at all time-points (p < 0.05). CD43(+) cell ratio of EPO group increased significantly in whole period (p < 0.05). CT scanning displayed femoral cortical thickening, medulla canal narrowing and lumbar spine density increasing at day 150, meanwhile, HE staining and reticular fiber staining showed the fatty degeneration or vacuolization in liver, splenomegaly with megakaryocytic proliferation, femur bone marrow fibrosis and osteosclerosis. It is concluded that the mouse induced by high dose of rhEPO displays the myelofibrosis associated with splenic extramedullary hemopoiesis, and this study is useful to establish a practical MF model, and to explore its pathological mechanism.

Characteristics and clinical significance of CD73 expression in subtypes of leukemia / 中国实验血液学杂志

The study was purposed to investigate the expression of CD73 on bone marrow nucleated cells (BMMNC) in various leukemia subtypes and its relationship with cell differentiation of leukemia. Immunocytochemistry staining and Wright-Giemsa staining of BMMNC from 75 cases of leukemia, 11 cases of myelodysplastic syndrome (MDS), 13 cases of non-leukemic patients and 9 healthy adults were performed, and the CD73(+) ratio in BMMNC and its relationship with differentiation of leukemia cells were analyzed. The results showed that the ratios of CD73(+) in BMMNC of com-B ALL, pre-B ALL and PLL were significantly higher than those in B-CLL (p < 0.05). CD73(+) ratios in AML subtypes of M(1), M(2a), t (8; 21), t (15; 17), M(4) and M(5) were markedly higher than those in MDS respectively, but in M(6) and MDS were lower and had no statistical difference between them. CD73(+) ratios in T-ALL, B-CLL, M(6), MDS, non-leukemia patients and healthy adults were close to each other and all of them were lower than those in B-ALL and other AML subtypes. It is concluded that the expression of CD73 is associated with leukemia subtype, differentiation and development. The higher differentiation of leukemia cells, the lower of CD73 expression in myeloid and B lymphoid leukemia, but T-ALL does not meet this pattern.

Correlation between ultrastructural abnormality of bone marrow cells and anemia and neutropenia in myelodysplastic syndrome / 中国实验血液学杂志

The aim of study was to investigate the relationship of anemia and neutropenia with ultrastructural abnormalities of erythroblasts and young neutrophils in bone marrow of patients with myelodysplastic syndrome (MDS). Anemia parameters and peripheral neutrophil amount of 74 patients with MDS were measured by automatic hemocyte analyzer. According to Hb value and neutropenia degree, MDS patients were divided into 4 groups: normal, mild, middle and severe anemia or neutropenia. The morbid rate and apoptosis rate of erythroblasts and young neutrophils in bone marrow were measured by transmission electron microscopy (TEM). The results indicated that 68 out of 74 patients were consistent with anemia diagnostic criteria, and 51 out of 68 patients were with neutrocytopenia. TEM showed different abnormal features of erythroblasts and young neutrophils in all patients. The morbid rates of erythroblasts in normal, mild, middle and severe anemia groups were 37 ± 14.7%, 24 ± 9%, 32 ± 16% and 34 ± 21% respectively, while apoptotic rates of erythroblasts in normal, mild, middle and severe anemia groups were 2.25 ± 1.03%, 4.43 ± 2.60%, 8.78 ± 4.04% and 11.67 ± 4.57% respectively. The morbid rate and apoptotic rate of erythroblasts were correlated negatively with Hb and HCT value (p < 0.05). The apoptotic rates of bone marrow young neutrophils in 4 groups with different degree of neutropenia were 6.00 ± 2.67%, 9.50 ± 4.42%, 13.00 ± 3.54% and 17.00 ± 2.39%, which correlated negatively with peripheral neutrophil quantity (p < 0.01). Morbid rates of neutrophils in normal, mild, middle and severe anemia groups were 12.25 ± 16.31%, 13.5 ± 10.01%, 23 ± 8.59% and 51.67 ± 19.67% respectively, which positively correlated with its apoptotic rates (p < 0.01). It is concluded that anemia and neutropenia in patient with MDS are correlated with apoptosis and morbid rate of erythroblasts and young neutrophils in bone marrow, which may result in ineffective hematopoiesis.

Comparison of effect between homologous recombinant gene knockout and siRNA gene silence in cell lines / 中国实验血液学杂志

The objective of this study was to compare the effects between knocking-out Sam68 gene by homologous recombination method and silencing the gene by siRNA silencing technique in DT40 cell line. Gene targeting technique was used to isolate Sam68 gene-deleted chicken DT40 cells. Meanwhile, Sam68 gene silencing cells was obtained by using stable expression of siRNA plasmid pSilencer-Sam68. Then, the function of these two cell lines were analyzed by comparing with wild-type DT40 cell line. The results showed that the growth retardation in Sam68 gene knocked-out cell line was observed due to elongation of the G2/M phase, but which could not be found in Sam68 gene silencing cell line. It is concluded that in accordance with study of protein function in living cells, use of gene knockout technique for cell line can provide the experimental results more real than those resulting from gene silence technique.