Differential expression profiles of MicroRNA during the development of human cord blood CD34(+)CD38(-) cells to CD34(+)CD38(+) cells / 中国实验血液学杂志

To establish a basis for deep investigation of the role of microRNA (miRNA) in the regulation of hematopoiesis, differential expression profiles of miRNA between human cord blood CD34(+)CD38(-) and CD34(+)CD38(+) cells were analyzed. Mononuclear cells from cord blood (CB) of healthy donors were separated by Ficoll-Hypaque density gradients. CD34(+)CD38(-) and CD34(+)CD38(+) cells were sorted by using FACS Vantage SE. Their mRNA were then extracted and hybridized to miRNA microarray chip. The resulting data were analyzed with GeneSpring and informatics technique. The results showed that eleven miRNAs were found to be downregulated and 73 miRNAs to be upregulated by at least two-fold in the CD34(+)CD38(+) cells of CB, compared with the CD34(+)CD38(-) cells, which maintained CD34(+)CD38(-) cells' self-renewal and multiple lineage potential, that were defined as "stemness" miRNAs. 12 of the 84 genes (14.29%) were common to 33 hematopoietic-expressed miRNAs expressed by CD34(+) cells from both peripheral blood and bone marrow in Georgantas's study, which included 10 upregulated miRNAs (hsa-miR-23b, -26b, -92, -107, -130a, -181a, -197, -213, -222, -223) and 2 downregulated ones (hsa-miR-16a, -155). Some "stemness" miRNAs undergo CD34 antigen-like expression pattern during development and commmitted differeniation of hematopoietic stem cell/progenitors. Hematopoiesis-associated miRNA clusters and putative target genes could be found with informatics technique. It is concluded that the hematopoietic "stemness" miRNAs play important roles in normal hematopoiesis: miRNA expression profiles of hematopoietic stem cell/progenitors --> their gene expression profiles --> their self-renewal and lineage-commmitted differeniation.

Fine needle aspiration cytology diagnosis of extramedullary leukemic infiltration / 中华病理学杂志

<p><b>OBJECTIVES</b>To assess the diagnostic accuracy of fine needle aspiration cytology (FNAC) in extramedullary leukemic infiltration.</p><p><b>METHODS</b>The results of FNAC from 65 cases of extramedullary leukemic infiltration were reviewed and analyzed.</p><p><b>RESULTS</b>In the 65 cases studied, there were 24 cases of acute lymphoblastic leukemia (ALL), 25 cases of acute myelogenous leukemia (AML), 6 cases of chronic lymphocytic leukemia (CLL) and 10 cases of chronic granulocytic leukemia (CML). The commonest site of infiltration was lymph node, which accounted for 73.8% of all cases.</p><p><b>CONCLUSIONS</b>Accurate cytologic diagnosis of extramedullary leukemic infiltration relies on detailed morphologic assessment as well as correlation with clinical examination and other relevant laboratory findings, especially in patients whose initial symptom being a local mass. Leukemic infiltration, which represents proliferation of primitive cells, should be distinguished from non-Hodgkin's lymphoma. Morphologic assessment by oil immersion lens and examination of peripheral blood smears is useful in this respect.</p>

Fusion expression, purification and bioactivity assay of CpTI in Escherichia coli / 生物工程学报

CpTI (Cowpea Trypsin Inhibitor) is a widely used insect resistance gene in the plant genetic engineering for its high insecticidal activity and the minimal ability of the insects to evolve resistance to it. To facilitate the safety assessment of genetically modified foods (GMFs) with CpTI protein, we need to produce gram quantities of this protein in microbes. With the pGEX fusion expression system, we expressed the GST-CpTI protein in E. coli BL21, which accounted for approximately 40% of germ proteins. By Glutathione Sephrose 4B affinity chromatography, GST-CpTI was obtained with the purity up to 90%. Overnight incubate the fusion proteins with Thrombin protease, we got the CpTI proteins cleavage of GST tag. Both of the GST-CpTI and CpTI proteins showed notable trypsin inhibitor activity. Immunization of rabbits with purified fusion protein generated high titer antibodies (> 20000), measuring by ELISA. Western Blotting also showed specific Ag-Ab binding band between the antiserum and the CpTI proteins no matter in the whole supersonic germ proteins or purified from the column. All these made a good ground for the further safety assessment of CpTI protein.