To investigate whether mesenchymal stem cells (MSCs) transplantation after acute myocardial infarction (AMI) can improve heart function and decrease infarct size in rabbits and their correlation.

To investigate the effects of time varied stress on the proliferation of myoblast in rats and provide the basic experimental data for the remodeling of tissue in functional orthopaedics.

The role of oval cells in hepatocarcinogenesis is unclear yet. This study was to explore the correlation of oval cells to hepatocarcinoma through dynamic observation on evolutive characters of oval cells in experimental hepatocarcinogenesis.

To explore the effects of manganese poisoning on the proliferation of neural stem cells (NSCs) in mice's hippocampus.

To induce bone marrow stem cells(BMSC) of rats to differentiate directionally towards chondrocytes in vitro and identify the differentiated cells.

To investigate the biological characteristics of endothelial progenitor cells (EPCs) from the umbilical cord blood (UCB), and to evaluate their oncogenicity after long-term culture in vitro.

To investigate the existence and distribution characteristics of neural stem cells in the eyes of adult human ciliary body and retina.

Self-renewal and multilineage differentiation of hematopoietic stem cell (HSC) are their functional characteristics. The regulation of HSC self-renewal is governed by a balance between positive regulatory signals promoting growth and negative regulatory signals resulting in apoptosis. Among the positive regulatory signals, HOXB4 activates distinct pathways that enhance self-renewal divisions of HSC without overriding the regulatory mechanisms that maintain normal steady-state hemopoiesis. The upregulation of HOXB4 gene expression can greatly promote the HSC self-renewal, but does not affect the HSC differentiation, the morphology and function of linage-specific cells and terminally-differentiated blood cells. Furthermore, HOXB4 can enhance the hematopoietic potential of embryonic stem cell (ESC), promoting the differentiation of ESC into hematopoietic cells. As a consequence, upregulation of HOXB4 expression and/or corresponding HOXB4 target genes can have enormous therapeutical potential for human HSC in the stem cell transplantation and gene therapy. In this review the regulatory role of HOXB4 in HSC self-renewal, "zero" effect of HOXB4 on differentiation specificity of HSC lines and terminal differentiation cells, and molecular mechanisms of regulating HSC self-renewal by HOXB4 are summarised.

The purpose of study was to evaluate the effect of stopping use of cyclosporine A (CsA) in reversion of donor chimeras of chronic myeloid leukemia (CML) patients relapsed after transplantation. Two CML patients were transplanted with allogeneic peripheral blood stem cells, and relapsed after transplantation, their bcr/abl gene and/or ph1 chromosome showed positive, donor chimeras decreased. For these two CML patients relapsed after transplantation, the use of CsA was stopped immediately, and the patient's body temperature, skin rash, blood picture, liver function and chimeras were planed to observe carefully. The results indicated that acute graft versus host disease (aGVHD) appeared in both patients. A hundred percent (100%) of donor chimeras were then found with bcr/abl gene and/or ph1 chromosome turning to negative in both patients. In conclusion, to stop using of CsA might be effective in the treatment of some CML patients relapsed after transplantation by reversing of donor chimeras and inducing graft-versus-leukemia (GVL) effect accompanied by GVHD.

The aim of study was to analyze the clinical, biological features, treatment outcome and prognosis of mixed-lineage acute leukemia (MAL). 48 MAL patients diagnosed according to European Group of International Leukemia (EGIL) scoring system were retrospectively analyzed and the analysis results were compared with that from 68 cases of AML and 61 cases of ALL. The results showed that the incidence of MAL in acute leukemia was 9.6%. Morphologically, the subtypes of M(1) and M(2) were predominant in AML, while L(2) in ALL. The median of white blood cell count in MAL was significantly higher than that of non-mixed-lineage cases (AML and ALL) observed during the same period (P < 0.05). The incidences of enlargement of liver, spleen and lymphonodes in MAL were higher than those in AML. The difference was significant (P < 0.01) and was not significant compared with those in ALL (P > 0.05). Coexpression of myeloid and B lymphoid antigens in MAL patients was predominant, its rate was 70.9%. The coexpression rate of T lymphoid and myeloid antigens was 20.8%, coexpression of B, T lymphoid and myeloid antigens was 8.3%. CD34 was expressed in 79.2% of MAL cases, it was higher than those expressed in AML (54.4%) and ALL (52.5%) (P < 0.01), which suggests that MAL might originate from malignant transformation of hematopoietic stem cells. Cytogenetic analysis revealed normal and abnormal karyotypes in 32.1% and 67.9% of MAL cases respectively. In MAL Ph chromosome abnormality incidence was 25% and was significantly higher than that in AML group (0%) (P < 0.01), but was not statistical defference with that in ALL group (16.7%) (P > 0.05). The completed remission rate of MAL was 38.1%, lower than CR rate in AML (70.8%) and ALL (72.2%) respectively (P < 0.01). Treatment outcomes were negatively related to the expression of CD34 antigen and Ph chromosome. It is concluded that MAL is supposed to be originated from stem cells, coexpression of lymphoid/myeloid antigens is the major feature of MAL which accompanies many poor prognosis factors and lower CR rate. Appropriate chemotherapeutic strategy should be further searched.

The Wilms' tumor gene (WT1) is a transcription factor involved in tumorigenesis, especially in leukemogenesis. However, the role of WT1 expression in nonmalignant hematopoietic cells remains unclear. Furthermore, due to alternative splicing at two sites: 17 amino acid residues of exon 5 (+17AA) and 3 amino acid residues (+KTS) between exons 9 and 10, WT1 gene has four main isoforms (17AA+/KTS+, 17AA+/KTS-, 17AA-/KTS+, 17AA-/KTS-, abbreviation: +/+, +/-, -/+, -/-). The isoforms probably existed in hematopoietic cells, which make the research more complex. The aim of study was to elucidate the expression and its isoforms of WT1 gene in different cell subsets of healthy bone marrow donors. The fluorescence RT-PCR detection system was established to measure the expressions of full-length WT1, WT1 (+17AA) and WT1 (+KTS) in CD34(+)CD38(-) (stem cell), CD34(+)CD38(+) (progenitor cell), CD15(+)CD11b(+) (granulocyte), CD33(+)CD14(+) (monocyte), CD20(+)CD5(-) (B-lymphocyte) and CD20(-)CD5(+) (T-lymphocyte) subsets from 18 normal human bone marrow samples. The results showed that WT1 expressed in CD34(+)CD38(-), CD34(+)CD38(+), CD15(+)CD11b(+) and CD33(+)CD14(+), but not in CD20(+)CD5(-) and CD20(-)CD5(+) subsets. The highest expression was in CD34(+)CD38(-), but decreased gradually in CD15(+)CD11b(+) and CD33(+)CD14(+) subsets. WT1 (+17AA), WT1 (+KTS) and WT1 (+/+) isoforms were predominant in CD34(+)CD38(-) and CD34(+)CD38(+) primitive subsets, while in CD15(+)CD11b(+) and CD33(+)CD14(+) the dominant isoforms were WT1 (-17AA), WT1 (-KTS) and WT1 (-/-). It is concluded that the expression of WT1 in normal bone marrow decreases gradually with cell differentiation. Hematopoietic cells may adjust the ratios of WT1 isoforms to inhibit or promote cell differentiation.

In order to explore the influence of purified donor regulatory T cells (T(Reg) cells) infused after allogeneic bone marrow transplantation (allo-BMT) on GVHD and hematopoietic reconstitution of mice, an allo-BMT model of C(57)BL/6-->BALB/c mice was established. CD4(+)CD25(+)T(Reg) cells were purified through bead-magnetic activated cells separated from donor mice peripheral blood. The recipient mice were randomly divided into three groups: CD4(+)CD25(+) T cells, CD4(+)CD25(-) T cells and RPMI 1640 culture medium. These cells and RPMI 1640 were infused into recipient mice by caudal veins at about 6 to 8 hours after allo-BMT respectively. Incidence of GVHD, pathological lesion of liver, spleen, small intestine, survival time and hematopoietic reconstitution in the recipients were observed after allo-BMT. The results showed that the time for WBC > 1.0 x 10(9)/L was (8.14 +/- 3.26) days, (17.62 +/- 5.71) days, (19.81 +/- 6.77) days and the time for Plt > 20.0 x 10(9)/L was (5.29 +/- 1.34) days, (8.97 +/- 3.44) days, (9.52 +/- 3.92) days in T(Reg) positive cell group, T(Reg) negative cell group and the blank control group respectively, and the recovery times of WBC and Plt in T(Reg) positive cell group were faster than that in T(Reg) negative cell group and the blank control group (P < 0.05). The scores of GVHD were (1.33 +/- 0.58), (1.80 +/- 0.27), (1.93 +/- 0.45) in three groups of mice at about 15 days after allo-BMT, respectively, the GVHD in T(Reg) positive cell group was slighter than that in T(Reg) negative cell group and the blank control group (P < 0.05). It was found that GVHD pathologic manifestations of the liver, spleen and small intestine in T(Reg) positive cell group were slighter in a certain extent than those in other two groups at about (25 - 30) days after allo-BMT. The mean survival time in three groups was (41.45 +/- 17.88) days, (18.75 +/- 14.39) days and (25.67 +/- 16.84) days after allo-BMT, respectively, which in the T(Reg) positive cell group was significantly longer than that in other two groups (P < 0.05). It is concluded that donor-T(Reg) cell infusion can mitigate the GVHD so as to reach hematopoietic reconstitution and prolong survival time after allo-BMT in mice.

The study was aimed to isolate and establish mesenchymal stem cell line from adult murine bone marrow as well as to identify its biological characteristics and differentiation potential. Bone marrow cells (BMCs) were collected by flushing the femurs and tibias of 4 - 5-week-old male C57BL/6 mice, and were inoculated at a concentration of 1 x 10(6)/cm(2). mMSCs were isolated, enriched and expanded by using bone marrow adherant culture and monoclonal culture. The characteristics of the cells, such as morphology, growth pattern, cell cycle, phenotype, karyotype and multipotent differentiation potential, cytogenetic stability and tumorigenesis were determined. The results indicated that the cell population consisted of spindle- and star-shaped cells, they were highly positive for CD29, CD44, Sca-1, MHC-I, moderate positive for CD13, CD90.2 and negative for CD117, CD45, Flk-1 and MHC-II. mMSCs could be induced to differentiate into adipocytes, osteoblast cells and chondrocytes. It is concluded that mMSC can be isolted, expanded and enriched by using bone marrow adhcrent culture and monoclonal culture. No tumor formations are observed for 3 months in nude mice after subcutaneous injection. mMSCs retain their properties after at least 30 passages in culture as well as from frozen stocks.

The purpose of this study was to synthesize the complex of magnetic nanoparticles and antibody, and to apply them to isolate the CD34(+) cells from umbilical cord blood, then to evaluate its separation efficiency. The complex of magnetic nanoparticles and antibody was used to separate CD34(+) cells from umbilical cord blood in the outer magnetic field because of its superparamagnetism, specific identification and function of combination with CD34(+) cells. Scanning electron microscopy was used to observe the morphology of the separated CD34(+) cells. Flow Cytometer was applied to evaluate the sorting efficiency of magnetic nanoparticles, liquid culture and colony culture were taken to assay proliferation and differentiation capacity of the separated CD34(+) cells. The results showed that the CD34(+) cells from umbilical cord blood were isolated fast and effectively by the complex of magnetic nanoparticles and monoclonal antibody. Moreover, the isolated CD34(+) cells still maintained its normal morphology, highly proliferative and differentiative capacity. It is concluded that the complex of magnetic nanoparticles and monoclonal antibody has been successfully synthesized and developed as a technique which efficiently and quickly isolates CD34(+) cells from umbilical cord blood.

As the lymphocytes of immuno-mediated aplastic anemia (IMAA) are in active state, and the hematopoietic stem cells are in silence, this study was aimed to design a new strategy to treat IMAA. To utilize the difference of radiosensitivity between active lymphocytes and silent hematopoietic stem cells, the animals suffered from IMAA were treated with a single low dose of irradiation, killing the active lymphocytes to release its suppression to hematopoietic stem cells without injuring the hematopoietic stem cells. Therefore, the hematopoiesis can be restored. Experiments were completed in IMAA mouse model. At day 4 after making IMAA, the model mice were giren total body irradiation of 150 cGy, the non-treated model mice and normal mice irradiated with 150 cGy were used as control. The survive time and survive rate of mice, blood picture, the account of nucleated cell of bone marrow, and pathological changes of bone marrow and lymphoid tissues of each group mice were observed. The results were as follows: (1) Survive rate of IMAA mice in non-treated group was 12.5%, the average survive time was 27.4 +/- 13.4 days. 100% of IMAA mice in irradiation-treated group survived over 60 days. The mice of irradiation control group all survived. (2) The account of WBC of IMAA mice in non-treated group dramatically decreased until to die, and in the irradiation-treated group it was gradually increased since the 10th day after treatment and close to normal level at the 28th day. (3) The RBC hematocrit of IMAA mice in non-treated group progressively decreased at day 14, and IMAA mice of irradiation-treated group gradually recovered closely to normal level after slightly fall at day 14, similar to the mice of irradiation control group. (4) The account of nucleated cells of bone marrow in non-treated IMAA mice dramatically decreased, and in the IMAA mice of the irradiation-treated group it was rapidly increased following transient fall, and restored to normal. (5) Pathological observations showed that the bone marrow and spleen of non-treated IMAA mice demonstrated typical aplastic anemia pattern, including bone marrow failure, marked splenatrophy, but the bone marrow and lymphoid tissues in the IMAA mice of irradiation-treated group were recovered to normal at day 28 after treatment. It is concluded that the low dose of irradiation displayed a significant therapeutic effect to IMAA mice, their hematopoisis could be completely restored to normal. The mechanism of therapeutic effect may contribute to low dose of irradiation killing the immunocompetent lymphocytes, therefore, suppressing hematopoiesis. The experiment results not only set up a new strategy for IMAA treatment, but also provided a clue to study the mechanism of IMAA.

CCL23 is a human CC chemokine with potential suppression effects on both human and murine myeloid progenitor cells both in vitro and in vivo, and only expressed and released by dendritic cells differentiated from monocytes in blood cells. However, recent study has shown that CCL23 was over-expressed in bone marrow and peripheral blood cells from pediatric patients with acute myeloid leukemia (AML). In order to investigate the effects of CCL23 on the development, therapy and prognosis of leukemia, the U937 cells, a leukemic cell strain, were adopted and cultured with rhCCL23 for 72 hours. The cell proliferation and apoptosis rate were detected by Cell Counting Kit-8 and FITC-AnnexinV/PI respectively; the morphologic changes and the expression of CCR1 (the only receptor of CCL23 known by now) were observed during the differentiation process. The results showed that no obvious effect on the proliferation, apoptosis and differentiation of U937 was found by using CCL23 alone (P > 0.05), but cultured in combination with CCL23 and PMA, the differentiation of U937 cells were promoted remarkably, during which the CCR1 expression increased (P < 0.05). It is concluded that CCL23 alone did not inhibit the proliferation and differentiation of U937, while its use in combination with PMA may possess synergistic effect on inducting differentiation of U937 through the increase of receptor CCR1 expression.

The aim of study was to explore the potential application of targeting at Toll-like receptors (TLRs) in the immunotherapy of acute myelocytic leukemia, and to investigate the expression of TLR and the effects of TLR 8 agonist ssRNA40/LyoVec on proliferation, apoptosis and cell cycle of U937 cells. The expression of TLR 1 - 9 in U937 cells was detected by using reverse transcription polymerase chain reaction (RT-PCR) and the expression of TLR 8 was assayed by flow cytometry (FCM). The effect of TLR 8 agonist, ssRNA40/LyoVec, at different concentrations on U937 cells proliferation was evaluated by CCK-8, apoptosis and cell cycle were detected by FCM. The results showed that U937 cells expressed TLR 1 - 9. TLR 8 agonist ssRNA40/LyoVec could inhibit the growth of U937 cells both in time-and dose-dependent manner and the inhibitory rate could reach 70%. It also increased the percentage of cells in G(0)/G(1) phase. There was no significant difference in percentage of apoptotic cells between control and treated groups. It is concluded that TLRs including TLR 1 - 9 express on U937 cells and TLR 8 agonist ssRNA40/LyoVec may be able to inhibit the growth of U937 cells, arrest the cells in G(0)/G(1) phase, but have no effect of promoting apoptosis.

To investigate the possibility of differentiation of human mesenchymal stem cells (hMSC) into epidemic cells in vitro.

To study isolation, identification and differentiation characteristics of dermal multipotent stem cells from human of different age in vitro culture.

To isolate and culture mesenchymal stem cells ( MSC) from different sources and to investigate the chemotactic effects of burn rat serum on MSC derived from different sources.