Aplastic anemia is an acquired bone marrow failure syndrome,characterized by an empty bone marrow,pancytopenia,as well as anemia,bleeding,infection syndrome.The pathogenesis of aplastic anemia has not yet been completely clear.Some of the proposed causes include hematopoietic stem/ progenitor cell deficiency,immune disorders,and abnormalities in the hematopoietic microenvironment.In recent years,further clinical and experimental studies have accumulated to recognize the pathogenesis of aplastic anemia.

Pneumocystis carinii pneumonia (PCP) is a life-threatening opportunistic infection in immunocompromised patients.In recent years,the incidence of PCP has increased significantly since the application of combined chemotherapy,immunosuppressant and hematopoietic stem cell transplantation,with improved long-term efficacy in pediatric blood disease.This review summarizes the clinical manifestations,laboratory and radiological examination,diagnosis,treatment and prophylaxis.Compound Sulfamethoxazole is the most commonly used agent for prophylaxis.It is recommended for the high-risk patients to take PCP prophylaxis,which could decrease the incidence of PCP.

Objective To explore the diagnosis and therapy of pulmonary fungal infection in childhood hematological diseases. Methods A retrospectively clinical analysis was carried out in 22 cases of childhood hematological diseases treated with amphotercin B and itraconazole. Results 10 out of 22 cases had the respiratory manifestations. X rays in chests showed shadows with features of stigma and sheet in 17 cases. Candida albicans and aspergillus infection were observed in 10 and 1 cases respectively. The numbers of neutrophil were below 0.5×109/L in 6 cases and below 0.1×109/L in 9 cases respectively. 18 cases were treated with glucocorticoid except for those occasionally application in blood transfusion. Intravenous dripping broad spectrum antibiotics and inhaling amphotericin B were used for more than 5 days in all cases. Itraconazole was used for more than 2 weeks after clinical symptoms were not improved 5 days later. The results showed that clinical symptoms of 13 cases were improved within two weeks and only 1 case died. Conclusion The occurrence of pulmonary fungal infection in childhood hematological diseases is associated with intensive chemotherapy, neutropenia and usage of broad spectrum antibiotics. Experimental therapy with amphotercin B and intraconzole is effective and worth of being widely spread.

Objective To investigate the expression of Toll-like receptor 4 (TLR4) and myeloid derived suppressor cells(MDSC) in bone marrow cells in children with acute myeloid leukemia (AML),and to detect its relationship with the clinical features,the effect of chemotherapy and prognosis.Methods Twenty-nine cases of children with AML were collected from June 2013 to March 2014 in People's Hospital of Wuhan University,in which 11 cases of low-risk group,10 cases of middle-risk group,8 cases of high-risk group;and 17 cases of non blood disease was as the control group.The expressions of TLR4 and MDSC were detected by using reverse transcription-polymerase chain reaction (RT-PCR),Western blot methods,immunohistochemical staining,and flow cytometry,respectively,in the bone marrow cells of 29 children with AML.Results The mRNA and protein expression of TLR4 in the initial treatment group was higher than those in the complete remission group(t =3.092,3.393,all P ＜ 0.05).The mRNA and protein expression of TLR4 in the relapse group was higher than those in the complete remission group(t =4.013,4.279,all P ＜ 0.05).The positive expression rates of MDSC in the above 3 groups were (29.77 ± 1.39) ％,(5.19 ± 0.65) ％,(38.62 ± 3.54) ％,respectively,compared with the control group [(1.32 ± 0.27) ％] and there was significant difference(all P ＜0.05).The positive expression rates of TLR4 and MDSC in the initial treatment group,relapse group and complete remission group were significantly higher than those in the control group,with significant differences (initial treatment group TLR4:t =3.559,P ＜ 0.05;MDSC:t =3.727,P ＜ 0.05;relapse group TLR4:t =4.043,P ＜ 0.05;MDSC:t =4.125,P ＜ 0.05;complete remission group TLR4:t =2.798,P ＜ 0.05;MDSC:t =3.469,P ＜ 0.05).Pearson rank correlation analysis showed that there was a positive correlation between the expression of TLR4 and MDSC (r =0.673,P ＜0.01).Conclusions The expressions of both TLR4 and MDSC play an important role in onset,progression,curative effect and prognosis in children with AML,and the two may play an importment role in synergistic effect.

Objective To investigate the molecular mechanism underlying lymphocyte functionassociated antigen-1 (LFA-1) / intercellular adhesion molecule-1 (ICAM-1) mediated anti-neoplastic effects of cytokine induced killer (CIK) cells. Methods Lymphocytes isolated from peripheral blood of children leukemia were induced with interferon-gamma (IFN-y), anti-CD3 monoclonal antibody (CD3McAb) and interleukin-2 (IL-2) and co-cultured with dendrite cells (DC) to generate DC-CIK cells. When treated with LFA-1 monoclonal antibody, cytotoxicity of DC-CIK cells against leukemia cell lines was measured by the MTT assay, while RT-PCR and Western blotting were used to determine mRNA and protein expressions of GATA-3 and T-bet in DC-CIK cells, respectively. IL-12, IFN-γ and tumor necrosis factor-α (TNF-α) levels released by DC-CIK cells were quantified by ELISA. Results Induced DC-CIK cells were regular, round and transparent with variable cell volume and cellular aggregation. When treated with mouse anti-human LFA-1 monoclonal antibody, the cytotoxicity decreased mostly towards B95 cells under administration of 20 μg/ml LFA-1 monoclonal antibody in comparison with the control group(t =10.138, P ＜0.05). It led to a highest elevation of GATA-3 mRNA and protein levels (t =16.386, P ＜ 0.05; t =22.652, P ＜ 0.05) and a most decrease of T-bet mRNA and protein levels (t =17.728, P ＜0.05; t =17.452, P ＜0.05) under 20 μg/ml LFA-1 monoclonal antibody in B95 cells group in comparison with the control group. The expression levels of IL-12,IFN-γ, and TNF-o in supernatant were the lowest under 20 μg/ml LFA-1 monoclonal antibody in B95 cells group in comparison with the control group (t =21.621, P ＜0.05; t =13.739, P ＜0.05; t =15.278, P ＜0.05).Conclusion GATA-3 and T-bet were implicated in the LFA-1/ICAM-1 mediated anti-neoplastic effects of DC-CIK cells via activation of the Th1 pathway, with high secretion of Th1 cytokines, such as IL-12, IFN-γ and TNF-α.

Objective To explore the related factors of nosocomial infection in children with leukemia and its character.Methods Retrospective analyzed 96 leukemia children with nosocomial infection who were come from 220 patients with acute leukemia.The information of the infection rate at different chemotherapy stages,different hospitalization time,site of infection and strain condition were recorded.Results (1) The infection rate of leukemia children at induction and consohdation stage were 85.7％ (24/28) and 76.7％ (23/30) respectively.(2) The infection rate increased with the duration of hospitalization periods.The infection rate was 8.6％ (3/35) at 0-7 d hospitalization periods and 62.7％ (42/67) at 15-30 d hospitalization periods.(3) The infection was prone to occurring at respiratory tract (58.3％,56/96),followed by gastrointestinal tract (17.7％ (17/96)),blood (13.5％ (13/96)),skin (8.3％ (8/96)) and other parts (2.1％ (2/96)).(4) The most frequency stain listed as Escherichia coli(21.8％ (26/96)),and Citrobacter (16.8％ (20/96)).The lower detection rates of the bacteria listed as Candida albicans (2.5％ (3/96)),Aspergillus(1.7％ (2/96)) and yeast (0.8％ (1/96)).Condusion Even though the survival rates of leukemia children is increasing due to technology development,nosocomial infection frequently occur.The high infection rates occur at chemotherapy induction and consolidation phase.Therefore intervention should be taken based on nosocomial infection in children leukemia such improving the environment of ward,enhancing the immune ability of children in order to decrease the incidence of hospital infection.

Objective To explore the expression of antiapoptotic gene Aven in childhood acute lymphoblastic leukemia (ALL) and its relationship with clinical features of ALL. Methods Reverse transcriptase polymerase chain reaction (RT-PCR) was used to detect the expression of Aven mRNA in 55 cases of childhood ALL The control group included 11 childhood patients with no malignant hematological diseases. Results Aven mRNA expression was found to be higher in patients ≥10 years old and was also significantly higher in relapsed patients. Univariate and multivariate analysis indicated that Aven overexpression was an independent poor prognostic factor. Conclusion Aven mRNA expression is abnormal in childhood ALL and is an independent poor prognostic factor.

Human cytomegalovirus (HCMV) late mRNA expression in megakaryoblast and in turn the pathogenesis of idiopathic thrombocytopenic purpura (ITP) patients with HCMV infection, and effectiveness of ganciclovir were investigated. Colony forming unit-megakaryocytes (CFU-MK) of 46 ITP patients with HCMV infection were incubated from patients' bone marrow mononuclear cells (MNC). Reverse transcriptase-polymerase chain reaction (RT-PCR) was subsequently used for CFU-MK for HCMV-late mRNA detection. Ganciclovir therapy was given to both HCMV-late mRNA positive and negative groups for comparison of therapeutic effectiveness. The results in 19 of 46 CFU-MK culture cells specimens with positive HCMV-DNA by PCR or positive CMV-IgM by enzyme linked immunosorbent assay (ELISA) in the correspondent serum of peripheral blood were positive for HCMV-late mRNA. Sixteen out of 19, patients with positive HCMV-late mRNA CFU-MK had a positive response to ganciclovir. Amongst 27 patients with negative HCMV-late mRNA CFU-MK, only 4 positive responders to ganciclovir therapy were observed. Curative effectiveness of ganciclovir in HCMV-late mRNA positive group was significantly higher than that in HCMV-late mRNA negative group (P<0.01). It was suggested that HCMV could directly infect CFU-MK, which might be one of the mechanisms responsible for HCMV related ITP. The ganciclovir is an effective therapy in resulting in the increases in thrombocyte in the ITP patients whose HCMV- late mRNA was positive in their CFU-MK.

To investigate the role of AQP9 in brain edema, the expression of AQP9 in an infectious rat brain edema model induced by the injection of lipopolysaccharide (LPS) was examined. Immunohistochemistry and reverse transcription-polymerase chain reaction (RT-PCR) analysis demonstrated that the expressions of AQP9 mRNA and protein at all observed intervals were significantly increased in LPS-treated animals in comparison with the control animals. Time-course analysis showed that the first signs of blood-brain barrier disruption and the increase of brain water content in LPS-treated animals were evident 6 h after LPS injection, with maximum value appearing at 12 h, which coincided with the expression profiles of AQP9 mRNA and protein in LPS-treated animals. The further correlation analysis revealed strong positive correlations among the brain water content, the disruption of the blood-brain barrier and the enhanced expressions of AQP9 mRNA and protein in LPS-treated animals. These results suggested that the regulation of AQP9 expression may play important roles in water movement and in brain metabolic homeostasis associated with the pathophysiology of brain edema induced by LPS injection.
Aquaporins/genetics ; Aquaporins/*metabolism ; Blood-Brain Barrier/metabolism ; Brain/drug effects ; Brain/physiology ; Brain Edema/chemically induced ; Brain Edema/*metabolism ; Lipopolysaccharides ; Rats, Sprague-Dawley ; Water/physiology

DNA repair processes play a role in the development of drug resistance which represents a huge obstacle to leukemia chemotherapy. Histone H2AX phosphorylation (ser139) (γH2AX) occurs rapidly at the onset of DNA double strand break (DSB) and is critical to the regulation of DSB repair. If DNA repair is successful, cells exposed to anti-neoplastic drugs will keep entering the cycle and develop resistance to the drugs. In this study, we investigated whether γH2AX can be used as an indicator of tumor chemosensitivity and a potential target for enhancing chemotherapy. K562 and multi-drug resistant cell line K562/A02 were exposed to adriamycin (ADR) and γH2AX formed. Flow cytometry revealed that percentage of cells expressing γH2AX was increased in a dose-dependent manner and the percentage of K562/A02 cells was lower than that of K562 cells when treated with the same concentration of ADR. In order to test the potential of γH2AX to reverse drug resistance, K562/A02 cells were treated with PI3K inhibitor LY294002. It was found that LY249002 decreased ADR-induced γH2AX expression and increased the sensitivity of K562/A02 cells to ADR. Additionally, the single-cell gel electrophoresis assay and the Western blotting showed that LY249002 enhanced DSBs and decreased the expression of repair factor BRCA1. These results illustrate chemosensitivity can partly be measured by detecting γH2AX and drug resistance can be reversed by inhibiting γH2AX.