[Relationship between macrophages and erythropoiesis].

Macrophages have two major roles in regulating the dynamic equilibrium in erythropoiesis, promoting the differentiation and maturation of nucleated red blood cells into reticulocytes and removing old red blood cells. A recent mouse study has demonstrated that the phenotype of macrophages in erythroblastic islands is CD169+ VCAM-1+ ER-HR3+ CD11b+ F4/80+ Ly-6G+. Molecular connections between erythroid progenitor cells and central macrophages help to maintain the function and integrity of erythroblastic islands.

[Detection of copy number variations in pediatric ETV6/RUNX1-positive acute lymphoblastic leukemia with multiplex ligation-dependent probe amplification].

Objective: To investigate the application of multiplex ligation-dependent probe amplification (MLPA) in the detection of copy number variations (CNVs) in pediatric ETV6/RUNX1-positive acute lymphoblastic leukemia (ALL), to compare this method with conventional karyotype analysis and fluorescence in situ hybridization (FISH), and to evaluate the value of MLPA.

Methods: The clinical data of 95 children with ETV6/RUNX1-positive ALL who were treated from January 2006 to November 2012 were analyzed retrospectively, including clinical features, results of karyotype analysis, and results of FISH. CNVs were detected with MLPA.

[Significance of IKZF1 gene copy number abnormalities in BCR/ABL-negative B-lineage acute lymphoblastic leukemia in children].

Objective: To identify IKZF1 gene copy number abnormalities in BCR/ABL-negative B-lineage acute lymphoblastic leukemia (B-ALL) in children, and to investigate the association between such abnormalities and prognosis.

Methods: Multiplex ligation-dependent probe amplification (MLPA) was applied to detect IKZF1 gene copy number abnormalities in 180 children diagnosed with BCR/ABL-negative B-ALL. These children were classified into IKZF1 deletion group and IKZF1 normal group according to the presence or absence of IKZF1 gene deletion.

Transcriptome analysis of Rpl11-deficient zebrafish model of Diamond-Blackfan Anemia.

To comprehensively reflect the roles of Rpl11 on the transcriptome of zebrafish model of Diamond-Blackfan Anemia (DBA), we performed whole-genome transcriptome sequencing on the Illumina Hi-Seq 2000 sequencing platform. Two different transcriptomes of zebrafish Rpl11-deficient and control Morpholino (Mo) embryos were collected and analyzed. The experimental design and methods, including sample preparation, RNA-Seq data evaluation and treatment, were described in details so that representative high-throughput sequencing data were acquired for assessing the actual impacts of Rpl11 on zebrafish embryos.

[Efficacy and safety of imatinib for the treatment of Philadelphia chromosome-positive acute lymphoblastic leukemia in children].

Objective: To study the efficacy and safety of Chinese Childhood Leukemia Group ALL 2008 (CCLG-ALL2008) protocol combined with tyrosine kinase inhibitor (TKI, imatinib) for the treatment of Philadelphia chromosome-positive (Ph+) acute lymphoblastic leukemia (ALL) in children.

Methods: The clinical data of 53 patients aged less than 15 years when first diagnosed with Ph+ ALL between October 2008 and December 2013 were retrospectively analyzed. The patients were assigned to two groups: HR (n=26) and HR+TKI (n=27).

Prediction of outcomes by early treatment responses in childhood T-cell acute lymphoblastic leukemia: a retrospective study in China.

Background: Early treatment responses are important prognostic factors in childhood T-cell acute lymphoblastic leukemia (T-ALL) patients. The predictive values of early treatment responses in Chinese childhood T-ALL patients were still unknown.

Methods: From January 2003 to December 2012, 74 consecutive patients aged ≤ 15 years with newly diagnosed T-ALL were treated with BCH-2003 protocol or CCLG-2008 protocol in the Department of Pediatric, Institute of Hematology and Blood Diseases Hospital in China.

[Effect of Below-cloud Secondary Evaporation in Precipitations over the Loess Plateau Based on the Stable Isotopes of Hydrogen and Oxygen].

Based on stable isotopes in 409 precipitation samples provided by GNIP and meteorological records at the eight stations in Loess Plateau from January 1985 to December 2004, as well as the trajectory model of HYSPLIT 4.9, the spatial and temporal variations of d-excess and Δ18O were analyzed. The spatial distribution of secondary evaporation rate and the impact of meteorological factors on below-cloud secondary evaporation were also discussed.

Mutation analysis of Chinese sporadic congenital sideroblastic anemia by targeted capture sequencing.

Background: Congenital sideroblastic anemias (CSAs) comprise a group of heterogenous genetic diseases that are caused by the mutation of various genes involved in heme biosynthesis, iron-sulfur cluster biogenesis, or mitochondrial solute transport or metabolism. However, approximately 40% of patients with CSA have not been found to have pathogenic gene mutations. In this study, we systematically analyzed the mutation profile in 10 Chinese patients with sporadic CSA.

[Copy number variations in pediatric acute myeloid leukemia].

Objective: To evaluate the copy number variations (CNV) of gene in pediatric acute myeloid leukemia (AML) and its correlation with clinical features and prognosis.

Methods: The clinical data of 130 children aged <14 years with newly diagnosed AML from May 2006 to March 2013 were analyzed restrospectively. The CNV were analyzed by multiplex ligation-dependent probe amplification (MLPA).

[Clinical features of children with relapsed acute lymphoblastic leukemia treated with the CCLG-ALL2008 protocol].

Objective: To study the clinical features of children with relapsed acute lymphoblastic leukemia (ALL) treated with the CCLG-ALL2008 protocol.

Methods: The data of 591 children who were newly diagnosed with ALL and were treated with the CCLG-ALL 2008 protocol between April 2008 and June 2013 were collected, and the clinical features of 80 children with relapsed ALL were retrospectively analyzed.

Results: After treatment with the CCLG-ALL2008 protocol, the recurrence rate in the standard-risk, intermediate-risk and the high-risk groups were 7.

[Defectiveness of bone marrow mesenchymal stem cells in acquired aplastic anemia].

The defectiveness of bone marrow mesenchymal stem cells (BM-MSCs) in acquired aplastic anemia (AA) has been a frequent research topic in recent years. This review summarizes the defectiveness of BM-MSCs which is responsible for the mechanism of acquired AA and the prospective application of BM-MSCs in the treatment of acquired AA. An increasingly number of laboratory statistics has demonstrated that the defectiveness of BM-MSCs is more likely to play an important role in the pathogenesis of AA, namely, the apparently different biological characteristics and gene expression profiles, the decreased ability of supporting hematopoiesis as well as self-renewal and differentiation, and the exhaustion of regulating immune response of hematopoietic environment.

[Clinical features of childhood refractory cytopenia].

Objective: To study the clinical features of patients with refractory cytopenia of childhood (RCC).

Methods: The clinical data of 1 420 children (0-14 years old) with an initial diagnosis of non-severe aplastic anemia between January 1990 and June 2013 were retrospectively analyzed. Bone marrow cell morphology and histopathology were re-evaluated, and the patients were re-classified using the criteria proposed in the 2008 edition of the World Health Organization classification of RCC in hematopoietic and lymphoid tumor tissues.

[Methylation of the genes in the 9P21 region in children with acute myeloid leukemia].

Objective: To investigate the methylation rate of cyclin-dependent kinase inhibitor 2A (CDKN2A) and cyclin-dependent kinase inhibitor 2B (CDKN2B) in the 9P21 region in children with acute myeloid leukemia (AML) and the association of gene methylation with clinical features and outcomes.

Methods: The clinical data of 58 children who were newly diagnosed with AML between January 2010 and December 2012 were retrospectively analyzed. Thirty-eight healthy children were recruited as the control group.

[Gene mutations and clinical characteristics in children with juvenile myelomonocytic leukemia].

Objective: To study gene mutations and clinical features in children with juvenile myelomonocytic leukemia (JMML).

Methods: The clinical data of 14 children who were diagnosed with JMML and were examined for the detection of common gene mutations were retrospectively analyzed.

Results: Eleven (79%) out of 14 cases were male, and 3 (21%) were female.

Current insights into the diagnosis and treatment of inherited bone marrow failure syndromes in China.

Inherited bone marrow failure syndromes (IBMFs) account for 20% of pediatric BMFs. Although recommendations for the diagnosis and treatment of IBMFs in China have been published recently, improvements are still needed in making precise diagnoses and properly treating pediatric patients with IBMFs. This review provides current insights into IBMFs in China.

La-related protein 4B maintains murine MLL-AF9 leukemia stem cell self-renewal by regulating cell cycle progression.

Our recent study identified a nonsense mutation of La-related protein 4B (LARP4B) from whole genome sequencing of a 3-year-old female monozygotic twin pair discordant for MLL-associated acute myeloid leukemia (AML). To study the role of LARP4B in AML, we established a LARP4B-knockdown MLL-AF9 AML mouse model. Using this mouse model, we found that LARP4B knockdown significantly decreased leukemia cells in the peripheral blood, spleen, and bone marrow and prolonged the survival of AML recipient mice.

Bmi1 promotes erythroid development through regulating ribosome biogenesis.

While Polycomb group protein Bmi1 is important for stem cell maintenance, its role in lineage commitment is largely unknown. We have identified Bmi1 as a novel regulator of erythroid development. Bmi1 is highly expressed in mouse erythroid progenitor cells and its deficiency impairs erythroid differentiation.

Notch1-induced T cell leukemia can be potentiated by microenvironmental cues in the spleen.

Background: Leukemia is a systemic malignancy originated from hematopoietic cells. The extracellular environment has great impacts on the survival, proliferation and dissemination of leukemia cells. The spleen is an important organ for extramedullary hematopoiesis and a common infiltration site in lymphoid malignancies.

[Research progress in molecular biology of pediatric myelodysplastic syndrome].

Marked differences have been found in molecular characteristics between pediatric and adult myelodysplastic syndrome (MDS) patients. The incidence of gene mutations associated with myeloid malignances in pediatric patients is lower than in adults, while the incidence of aberrant methylation is similar between them. It is also worth noting that novel molecular factors such as mitochondrial DNA mutations may play a role in the pathogenesis of childhood MDS.

[Treatment outcome of childhood standard-risk and median-risk acute lymphoblastic leukemia with CCLG-2008 protocol].

Objective: To estimate the significance of the adjustment of acute lymphoblastic leukemia (ALL) risk group by monitoring minimal residual disease(MRD).

Method: Totally 285 children ALL patients who were diagnosed and systematically treated according to CCLG-2008 in Institute of Hematology and Blood Diseases Hospital, CAMS and PUMC, from April 2008 to August 2011 were prospectively selected. Among these cases, 62.