Research Progress of FLT3 Mutation in Acute Myeloid Leukemia --Review / 中国实验血液学杂志

Acute myeloid leukemia (AML) is a heterogeneous hematopoietic tumor originated from hematopoietic stem cells. FLT3 is an important receptor tyrosine kinase in cell signal transduction pathway and one of the common mutated genes in AML. AML patients with FLT3-ITD mutation have a poor prognosis and tendency to relapse. Therefore, early identification of FLT3 gene mutation and selection of appropriate treatment are particularly important. Currently, the small moleculetargeted drugs have been new treatment methods for AML patients with FLT3-ITD mutation, but accompanied drug resistance need to be solved. This paper reviews the mechanism of FLT3 mutation, the clinical significance of FLT3 mutation in AML, FLT3 inhibitors and drug resistance mechanism.

Research Progress on Ph-like Acute Lymphoblastic Leukemia--Review / 中国实验血液学杂志

Ph-like acute lymphoblastic leukemia (ALL) is a high-risk subtype of precursor B-cell acute lymphoblastic leukemia (BCP-ALL) with a gene expression profile and a high frequency of IKZF1 gene alteration similar to that of Ph-positive ALL, which is a clinically and biologically heterogeneous subtype of BCP-ALL. The prognosis correlats negatively with age increasing. The incidence of this "Ph-like" subtype may be higher in young adults. Ph-like ALL is characterized by genetic alterations that activate cytokine receptor genes and kinase signaling pathways. Prospective studies are needed to determine if incorporation of tyrosine kinase inhibitor-targeting kinase alterations into intensive chemotherapy regimens will improve outcome of patients with Ph-like ALL. The research progress of Ph-like ALL is summarised in this review, including epidemiology, genetic alterations and treatment..

Clinical significance of detecting peripheral T cell subsets in children with leukemia / 中国实验血液学杂志

This study was purposed to investigate the changes of peripheral blood T cells in children with acute leukemia at different stages and understand the immune status of children with leukemia. The CD4⁺, CD8⁺, CD4⁺/ CD8⁺ ratio, CD3⁺ and NK cells in 42 children with acute leukemia and 50 cases of normal children (as control group) were determined by flow cytometry at different periods after complete remission. The results showed that the CD3⁺ CD4⁺, CD8⁺ rate and CD4⁺/CD8⁺ ratio in newly diagnosed ALL and AML children were significantly lower than those in control group (P < 0.05). The NK cell count in newly diagnosed children with acute leukemia was significantly lower than that in control group (P < 0.05). Although the NK cell count in ALL and AML children gradually rose at 3, 6, 12 months after complete remission, but it still was statistically different from normal control group (P < 0.05). It is concluded that children with acute leukima have cellular immune disfunction at onset and during treatment, but the cell immune function gradually recovered after complete remission achieved. However, its recovery rate is slow. The results of this study can provided a basis for subsequently use of immunomodulations in leukemia children.

Theoretical analysis of natural frequency of externally prestressed concrete beam based on rigidity correction / 西安交通大学学报·英文版

A dynamic test on externally prestressed simply supported concrete beams separately with three typical types of tendon distributions was conducted. The results show that the natural frequencies of the beams increase with the increase in the prestressing force at the tensioning stage, and the natural frequencies decrease after the cracks occur in the beams. Following the calculation formula of natural frequency of externally prestressed beam, which was reported in a literature, the natural frequencies of the experimental beams are calculated, and big errors are found between the test results and the calculated ones of natural frequency values. As a result, this paper has tried to adopt two methods to correct the rigidity parameter of the concrete beam in the formula for natural frequency calculation, and to use the corrected formula to calculate the frequencies of the experimental beams. The calculation results indicate a good consistency with the experimental ones, which verifies the feasibility of the corrected formula.

Analysis of hematopoietic chimerism after non-myeloablative allogeneic peripheral blood stem cell transplantation / 中国实验血液学杂志

The aim of this study was to analyze the hematopoietic chimerism after non-myeloablative allogeneic peripheral blood stem cell transplantation (NAPBSCT). 28 patients received NAPBSCT were evaluated. The conditioning regimen included FBC (fludarabine, busulphan, cyclophosphamide) +/- Ara-C. Peripheral blood was collected before and after transplantation in different periods. Semi-quantitative assessment of hematopoietic chimerism was performed by short tandem repeat-polymerase chain reaction (STR-PCR), polyacrylamide gel electrophoresis (PAGE) and silver staining, and analyzed by Image Analysis System. The results showed that on day 30 after transplantation, one patient failed to engraft, but 22 cases formed complete chimerism (CC) and 5 cases were of mixed chimerism. On day 7 after transplantation, the average percentage of donor cells was 74.71%. The time of dominance of the donor-specific allelic pattern preceded the recovery time of neutrophils and platelets. The incidence of aGVHD in group CC was significantly higher than that in group MC (P < 0.05). There was no significant difference in the incidence of cGVHD and disease relapse between group CC and group MC (P > 0.05). One patient relapsed in CC status without a transitional stage of MC. One patient with MC rejected grafts in early stage. 3 patients with MC transferred to CC and got complete remission after early implementation of therapy. It is concluded that sequential and quantitative detection of chimerism may be of great value to evaluate engraftment and to predict graft rejection, disease relapse and GVHD. Furthermore, it may provide a basis for early intervention treatment in the related complications.

Advance of research on survivin in hematological malignancies--review / 中国实验血液学杂志

Survivin a novel member of the inhibitor of apoptosis protein family, is overexpressed in most types of cancer but not in normal differentiated adult tissues. Its mRNA expression levels among hematogical malignancies are characteristic in each type, subtype and distinctive in different phases of disease, making it a reliable diagnostic marker for clinical stages. Recently, researches indicate that high levels of survivin expression are associated with a poor prognosis and may be involved in tumor resistance to multiple chemotherapeutic drugs. In addition, experiments demonstrate that leukemic vaccination with DC pulsed with survivin antigen in vitro inhibit the proliferation of leukemic cells. Furthermore, when transferred survivin antisense oligodeoxynucleotide or dominant-negative mutant survivin into, malignant cells can be induced apoptosis mediated by downregulation in survivin expression. These findings suggest that survivin may serve as a potential target for biological strategies against hematological neoplasms. This review focuses on expression of survivin in hematological malignancies, effects of survivin on drug-resistance and prognosis of hematological malignancies, and application of survivin in the treatment of hematological malignancies.