To study the proliferative effect of low energy laser on human cord blood hematopoietic cells in vitro and the relationship between the effect of low energy laser and colony stimulating factor (CSF).

To investigate the cellular biological mechanism of leukocytosis produced by all-trans retinoic acid (ATRA).

To study the clonogenic potential of circulating malignant precursors in the peripheral blood of patients with multiple myeloma (MM).

To determine the effects of recombinant human FLT3 ligand (rhFL) on in vitro expansion of human cord blood CD34+ cells.

To determine the differences of the effect of ultraviolet-B(UVB) on lymphocyte and hematopoietic progenitor cell in cord blood.

To investigate the effects of hematopoietic growth factors (HGFs) on apoptosis of hematopoietic cells in myelodysplastic syndromes (MDS) patients.

To explore an efficient approach to enhance antitumor effect of suicide gene therapy by improving in vivo antigen presenting function and their immunological mechanisms.

To evaluate the hematopoietic potential of long-term cryopreserved human umbilical cord blood as well as the migration of the stem cells in nude mice.

To examine the feasibility of bone marrow hematopoietic stem cell transplantation for thalassemia major.

This paper reports 3 cases of allogeneic peripheral blood stem cell transplantation (Allo-PBSCT) for the patients with chronic myeloid leukemia (CML). The patients received MMC preparative regimen with high dose chemotherapy (Melphalan 170 mg/m2, p.o. on Day-5, MeCCNU 400 mg/m2, p.o. on Day-4, and Cyclophosphomide 60 mg/kg/day, i.v. on Days-3 and -2). The HLA-identical sibling donors received filgrastim (rhG-CSF) for mobilization at a dose of 300 micrograms/day for 6 days. Leukaphereses were done at the 6th day of mobilization. A median of 8000 ml (2 times total blood volume) of blood was processed the collecting: 2.5-4.5 x 10(8)/kg MNC, 12.8-20.0 x 10(6)/kg CD34+ cells (including 4.8-7.5 x 10(6)/kg CD34+CD33-, 8.0-13.0 x 10(6)/kg CD34+CD33+), and 3.5-4.3 x 10(5)/kg CFU-GM. Cyclosporin A and methotrexate were used for GVHD prophylaxis. Hematopoitic function recovered as for 14-20 days to > 0.5 x 10(9)/L of neutrophil count, and for 16-34 days to > 20 x 10(9)/L of platelet count. At day + 100, chromosome analysis of bone marrow cells showed that complete chimera without ph1 positive chromosome in Cases 1 and 3, and a partial chimera with 73% donor karyotype in Case 2. All patients now are in disease free survival. No episode of acute graft versus host disease (GVHD) developed. It was concluded that HLA matched sibling allogeneic PBSCT result in rapid hematopoitic reconstitution and the MMC conditioning regimen is effective both in leukemic cells eradication and in immunosuppression for stem cells engraftment, and the drug related toxicity could be tolerated by patients.

To study the clonal growth on single layer, agar of high proliferative potential colony-forming cells (HPP-CFC) of bone marrow obtained from both normal mice (NBM) and mice treated 2 days earlier with 5-fluorouracil (FU,BM) using conditioned media.

Eleven ES cell lines from C57BL/6J mice were established, with the primary culture of mice embryos as feeder cells and 1 x 10(3) units Leukemia Inhibitory Factor (LIF) in the DMEM (high glucose) medium. The frequency of establishment was 9.6%. Five of these ES cell lines were demonstrated karyotypically normal with diploid composition of over 70%. They shared the characteristics of early embryonic cells: positive for alkaline phosphatase activity and oct4 gene expression. They also showed high potency to differentiate into wide types of cells in vivo. Following injection of the blastocysts, three of them showed abilities to give rise to chimeras and MESPU35 cell line was identified to have high efficiency of colonization into the germline. The clones of MESPU35 cells maintained the germline competence and the mutant clone also retained the high potency to participate into the development of embryos. MESPU35 cells can serve as a valuable vehicle for the production of mutant mice.

Nine embryonic stem cell lines have been established from mouse strain 129/ter. Three of the nine ES cell lines were karyotypically normal. The nine cell lines showed some difference in the growth rate and the differential competence. Chimeras were made by injecting the ES cells into C57BL/6J blastocysts, and the germline compositions of the chimeras were detected by mating them with albino ICR mice. The results indicated that ES cell line MESPU21 and MESPU22 were both highly germline-competent. Comparing with other ones, these two cell lines both were karyotypically normal and propagated fast. The tissue composition of the teratocarcinomas derived from these cell lines appeared paralle to the results of chimera production. Careful manipulation during the process of ES cell establishment was helpful to obtain good cell lines.

To construct the recombinant vectors for embryonic stem(ES) cell gene targeting which contain the mouse coagulation factor IX (F IX) gene modified by PCR site-directed mutagenesis.

A MT-II gene targeting vector--pMT-II6.7 with 6.7kb sequences homolog to mMT-II and its flanking region has been transfected into Mespu22 with electroporation. We have got 26 positive clones from 104 G418 and Ganc clones with PCR method. From the karyotype analysis, we found two clones with 84% and 88% normal karyotype. They are clone 5-2 and 8-4. Using Southern analysis, we confirm that the two clones are homologous recombinants. These cell lines still have the pluropotential ability to differentiate both in vitro and in vivo. Now we have got a chimera mouse with cells from clone 8-4.

In order to observe the role of genetically modified Schwann cell (SC) with pSVP0Mcat in the regeneration of injured spinal cord, the cells were implanted into the spinal cord. Ninety SD rats were used to establish a model of hemi-transection of spinal cord at the level of T8, and were divided into three groups, randomly, that is, pSVP0Mcat modified SC implantation (Group A), SC implantation (Group B) and without cell implantation as control (Group C). After three months the presence of axonal regeneration of the injured spinal cord was examined by means of horseradish peroxidase (HRP) retrograde labelling technique and stereography. The results indicated that HRP labelled cells in Group A and B could be found in the superior region of injured spinal cord and the brain stem such as the red nuclei and oculomotor nuclei. The density of ventral hom neurons of the spinal cord and the number of myelinated axons in 100 microns of the white matter was A > B > C group. In brief, the pSVP0Mcat modified SC intraspinal implantation could promote regeneration of the injured spinal cord.

To establish a series of techniques of sex determination of human preimplantation embryo in order that preimplantation genetic diagnosis(PGD) can be used clinically.

Generation of germline chimeras is the crucial step in ES cell-mediated transgenesis. The prerequisite for germline chimerism is the maintenance of germline differentiating potency of ES cells, whereas production of germline chimeras is the only method to prove whether such potency is maintained. In order to investigate the germline differentiating potency of three newly established ES cell lines (MESPU21, MESPU22 and MESPU29), ES cells were introduced into host embryos from inbred C57BL/6J and outbred KMW or ICR through blastocyst injection or 8-cell stage morula injection. Totally 81 chimeras were obtained; among 42 test-bred ones, 19 were germline transmitters assessed by coat analysis, as is the first report of ES cell-embryo germline chimeras in China. MESPU21 and MESPU22 formed germline chimeras in high frequency and most of those chimeras produced ES cell-derived progeny in high proportion, which proved that both ES cell lines retained good germline differentiating potency and could be used as valuable cellular vehicles to introduce genetic modifications into mouse genome.

The protective effect of Cu, Zn, SOD on bone marrow hematopoietic progenitor cells of mice, under 4 degrees C storage was studied. The results showed, if 1.65 U or 0.165 U/ml SOD was added to the cell suspension for 3 days at 4 degrees C, the production rate of CFU-GM, CFU-E, BFU-E, CFU-Meg and CFU-Mix were 6.2, 2.6, 2.9, 4.0 and 5.1 times that of control group (without SOD) respectively. The survival rate of hematopoietic progenitor cells increased obviously. The mechanism of SOD effect is supposed to prevent hematopoietic progenitor cells from death, instead of the regulating proliferation. It may be closely related to the antioxidation of SOD which scavenges the superoxide free radicals.

Analysis of pathogenic gene linkage and hemopoietic characteristics in a kindred with sideroblastic anemia.