To investigate the probabilities of embryonic stem (ES) cells differentiating into neuronal cells in vitro.

CD34+ is an immunophenotype of hematopoietic stem cells/progenitors. CD34+ cells selection in vitro may deplete T-cells 4-5 logs and tumor cells 3-4 logs. It will benefit to mismatched related donor allo-transplantation and autologous transplantation of tumor diseases.

To evaluate engraftment status of patients after allogeneic peripheral blood stem cell transplantation (allo-PBSCT) based on red blood cell type, karyotype and variable number of tandem repeats (VNTR).

The population growth and metabolism of hematopoietic cells from cord blood were investigated without and with hematopoietic growth factors and the long-term growth kinetics of cells was studied. In static cultivation of hematopoietic cells, the population specific growth rate was 0.34 d-1, and the average double time 2 days. The greater part of glucose was consumed and 40 mmol/L lactate was formed during cell culture. For the long-term culture, the maximum output of CFU-GM appeared between the 2nd and 3rd weeks and that of BFU-E in the first week. With 50% medium exchange, the expansions of total cells, CFU-GM, and BFU-E came up to 14, 13, and 5 times, respectively.

To observe the effect of cyclophosphamide (CTX) and recombinant human granulocyte colony-stimulating factor(rhG-CSF, Filgrastim) on autologous peripheral blood stem cells (APBSC) mobilization.

In order to find out a predictor more accurate, reliable and convenient for platelet recovery capacity after peripheral blood stem cell transplantation (PBSCT).

To study the effect of T-lymphocytes on hematopoietic progenitors in patients with paroxysmal nocturnal hemoglobinuria (PNH).

To explore the contributive role of CD34+ cell amount in pathogenesis of clonal dominance in paroxysmal nocturnal hemoglobinuria (PNH).

To explore the relationship between the hematopoietic inhibitor and apoptosis of CD34+ cells in patients with severe aplastic anemia (SAA).

To explore the mechanism of the impairment of hematopoietic stem/progenitor cells in aplastic anemia(AA) mice.

To investigate the in vivo effect of hemin on erythroid progenitor of the normal and aplastic anemia mice.

In order to supply full objective basis about tympanoplasty with titanium, 30 middle ear caves of guinea-pigs were implanted titanium ring in accordance with different time groups. Both before and after titanium ring were implanted, the guinea-pigs were detected in biochemical criterion of blood, titanium content of the hair, the changing of auditory threshold, tissue structural of middle ear and inner ear by energy spectrometry, electro-physiology, microscopy and scanning electron microscopy. The results showed that function of hepatorenal and titanium content of hair haven't significant change between pre- and postimplantation of titanium ring. Only 10 days group, it appeared the rising of auditory threshold and inverting of cilia by ABR and scanning electron microscopy. In 10 days and 1 month groups, there were blood stain and inflammatory cells under mucosa. The results suggested that titanium is good biocompatibility and no toxic for organism and mucosa.

To explore human umbilical cord blood hematopoietic progenitor cells transduced with human O(6)-methylguanine-DNA-methyltransferase (MGMT) gene increase resistance to 1,3-Bis(2-Chloroethyl)-1-Nitrosourea(BCNU).

To screen efficient and specific new drugs against hepatitis C virus (HCV) and find the best target sequence of antisense oligodeoxynucleotides (ASODNs) targeting at HCV gene.

To duplicating the regulatory subunit p35Nck5a gene of mouse neuronal cdc2-like kinase in embryonic stem (ES) cells, about 12.2 kb of pGDTV vector for p35Nck5a gene duplication was constructed. The linearized pGDTV vectors were transfected into ES cells by electroporation. 245 drug-resistant cell clones were obtained in both G418 and GANC medium and the frequency of surviving cells was 6.22 x 10(-5). The ES cell clones were identified to have duplicated the p35Nck5a gene by use of both PCR and genomic Southern blotting, and the frequency of homologous recombination is 5.08 x 10(-7). The use of negative selection gene (HSV-tk) results in 7-fold increase at selection efficiency. This study lays the foundations of preparing mouse models of Alzheimer's disease.

Human CD 34+ hematopoietic cells, a distinctive cell population containing hematopoietic stem/progenitor cells, have the capability to highly self-renewal, differentiation into all lineages of committed progenitor cells and reconstitution of both long-term hematopoiesis and immune functions after transplantation. In our previous study, the morphological, ultrastructural and cytochemical features concerning CD 34+ hematopoietic cells obtained by a two-step isolated systems of CIMS-100/FACS 440 with 100% purity were depicted. Based on these observations on CD 34+ hematopoietic cells under light microscope, SEM and TEM, we recently analyze the sterological features of CD 34+ hematopoietic cells with the aid of Quantimet 970 automatic image analyser so that the three-dimension structures regarding CD 34+ hematopoietic cells could be further made clear. By a series of measures including image scan-->modulus transform-->shadow correction-->image store-->statistical analysis, some morphometric parameters of CD 34+ hematopoietic cells were obtained as the followings: diametrs 3.490-6.741 microns, perimeters 11.776-26.240 microns, surface area 9.565-35.686 microns2, form factors 1.048-1.840, nucleus-plasma ratio 0.55-0.72, mean light density 0.17675-0.65100, integral light density 2717.217-46661.000. These morphometric data combined with our previous results from morphology, ultrastructure and functional subsets of CD 34+ hematopoietic cells strongly demonstrate that CD 34+ hematopoietic cells are really a heterogenous population. The possible reasons causing heterogeneous are close associated with either different functional subsets or differentiation lineages. To our knowledge, this is the first identification of sterological features of CD 34+ hematopoietic cells.

About 30%-40% of hematopoietic stem cells in human fetal liver of 3-5 months are in S phase of cell cycle, much higher than the ratio of 10% of that in adult bone marrow. The existance of highly active hematopoietic stem cell proliferation stimulators is probably its molecular basis. CFU-S "suicide rate" in rats was adopted to detect the effective substance. Through several steps of separation, we obtained a relatively purified substance of 35 kDa, termed it as FLS-4. CD 34 positive cord blood cells were sorted and assayed for their response to FLS-4 in 3H-TdR incorporation assay. The response to FLS-4 alone was approximately 1 times the background response seen with no factor added. In combination with IL-6 and IL-3 produced response that was 2.9 and 6.5 fold respectively greater than that observed with no factor added, but was weakly in comparison with the effects of SCF. In combination with GM-CSF or IL-3, FLS-4 can stimulate the formation of blast-colonies. The results indicate that the FLS-4 is very likely to be a novel hematopoietic stem cell proliferation stimulator. In physical or biological characteristics, it exhibited a unique character different from IL-3, IL-6, GM-CSF, SCF or FLT3 ligand those are known to have hematopoietic stem cell proliferation stimulating activity. During the period of active hematopoiesis in fetal liver, FLS-4 might be the candidate in triggering hematopoietic stem cells from resting G0 to S phase.

While producing transgenic mice by ES cell route, it is important to know whether ES cells used have a strong ability to produce chimeras or not. In this report, two methods were used for studying the chimeric ability of two ES cell lines (HDC and MESPU-13). One method was the blastocyst microinjection, that is, chimeras were produced by injecting 15 ES cells into the cavity of C57BL/6J blastocysts. Another was GPI electrophoresis for examinizing the chimerism of ES cells in internal tisssues and organs of chimeras. The results showed that the ability of producing chimeras of MESPU-13 cells was stronger than that of HDC cells. The reason was discussed in detail.