AIM: To prepare a soluble hemangiopoietin(HAPO) protein and to construct pET22b(+) expression vector, to obtain pure recombinant HAPO protein and to measure its bioactivity. METHODS: HAPO cDNA was amplified using RT-PCR method from a commercial human fetal liver cDNA library. The resulting product was cloned into pET22b(+) vector and transformed into E.coli BL21(DE3). The recombinant protein was isolated and purified by Ni~(2+)-NTA chelating resin and the chromatographies of SP Sepharose FF. The adhesion of human umbilical vein endothelial cells (HUVEC) were measured by adhesion assay. RESULTS: HAPO gene with a reading frame of 897 bp was successfully cloned from human fetal liver cDNA library, the expressed pET22b(+)-HAPO fused protein existed in a soluble form, with the yield above 10% total bacterial protein and its purity achieved above 80%. The activity assay showed that the treatment of HAPO enhanced total adherence of HUVEC in a concentration-dependent manner. CONCLUSION: HAPO protein can be expressed in a soluble form. HAPO may facilitate the homing of hematopoietic stem/progenitor cells in vitro.

Objective: To investigate the expression of midkine (MK) gene in childhood acute lymphoblastic leukemia (ALL) and the clinical significance of MK thereof. Methods: The real-time PCR was used to assay MK gene expression in bone marrow of 15 normal children and 124 childhood ALL patients, including 73 patients in progression and 51 patients in complete remission. Three stratifications of progressing patients were established by prognostic factors such as white blood cell count, age, immunopherotype and response to the 7-day prednisolone prephase. Results: The significant statistic difference in MK gene expression was found between the progression group, the complete remission group and the normal group (P< 0.01). The MK gene expression was over-expressed in B-ALL than that in normal group. Furthermore, there was statistic difference between B-ALL and T-ALL (P< 0.01). But there was no difference in MK mRNA expression between the normal control and T-ALL. The assay in risk stratifications showed that the levels of MK gene were higher in standard risk group and mid-risk group than that in high risk group (P< 0.01 and P< 0.05, respectively). There was no significant difference between standard risk group and mid -risk group (P = 0.32). No correlations were found between MK level and age, gender or lactate dehydrogenase level in serum. The expression of MK was significantly lower in the group with higher white blood cells(WBC≥ 25×10~9/L) than that with lower WBC (WBC<25×l0~9/L) in peripheral blood (P< 0.05). Conclusion: The high level of MK was a favorable prognostic factor in childhood acute lymphoblastic leukemia patients.

OBJECTIVETo investigate the distribution characteristics of blood cells autophagy in hematologic diseases, as well as their possible pathomechanism.

METHODSRetrospective analysis of electron microscopy specimens of 3 277 patients with hematological diseases were performed. The blood cells autophagy was observed by transmission electron microscopy, and its distribution characteristics were analyzed. The pathomechanism of blood cell autophagy was explored in combination with clinical examination and diagnosis.

RESULTSThere were 15 samples were found to have mature granulocytes or nucleated erythrocytes autophagy. Of them, 6 cases were myelodysplastic syndrome (MDS), 2 acute leukemia, 1 in each of aplastic anemia, pure red cell aplastic anemia, thalassemia, iron deficiency anemia, lymphoma, multiple myeloma and polycythemia vera. Among 15 cases, 11 cases were found to have mature granulocytes autophagy, 4 cases nucleated erythrocytes autophagy. Besides autophagy, apoptosis occurred in 9 cases, cytolysis in 6 cases, megaloblastic change in 5 cases.

CONCLUSIONMature granulocytes or nucleated erythrocytes autophagy occurred more frequently in MDS among hematologic diseases, dyshaematopoiesis including apoptosis, cytolysis and megaloblastic change could induce autophagy function enhancement.

Apoptosis ; Autophagy ; Erythroblasts ; Granulocytes ; Hematologic Diseases ; Humans ; Microscopy, Electron, Transmission ; Retrospective Studies