To investigate the expression of human specific proteins in liver tissue obtained from goats engrafted with human hematopoietic stem cells (hHSC).

To establish a rat model for hepatic oval cell proliferation and to observe the relationship between 2-acetaminofluorene (AAF) dosage and oval cell proliferation in the rat liver.

Because of its special biological characteristics, myoblast might play a role in gene delivery and cell-to-biomaterial interactions. In this paper, the biological features of myoblast and its application on gene therapy and tissue engineering was discussed.

To study the bone formation and osteogenesis after transplantation of human periosteal mesenchymal stem cells(PMSC).

A series of experiments including cell culture and benzidine staining test were undertaken to investigate the effects of Ganoderma lucidum(Leyss ex Fr) Karst Compound(GLC) on the proliferation and differentiation of K562 leukemic cells. The results showed that different concentrations of GLC(from 4 mg.ml-1 to 12 mg.ml-1) could promote human bone marrow granulocyte-macrophage colony forming unit (CFU-GM) proliferation, but suppressed the growth of K562 leukemic cell colonies, and IC50 was 9.2 mg.ml-1. The data from liquid culture demonstrated that GLC could suppress K562 cells proliferation in a dose-dependent(from 4 mg.ml-1 to 20 mg.ml-1) and time-dependent(from 1-5 days) manner. K562 cells could be induced to differentiate into more mature erythrocytic cells by 4 mg.ml-1 and 8 mg.ml-1 GLC. It is concluded that GLC may be a good medicine for leukemia therapy.

Howiinol A(1), one of the active antitumor constituents from the root and stem bark of Goniothamus howii Meer. (Annonaceae) has been synthesized in nine steps from alpha-D-glucoheptonic gamma-lactone with an over all yield of 13.3%. It shows that all data of the synthetic product are identical to those of the natural howiinol A, thus the absolute configuration of natural howiinol A is further confirmed as 1. In the search for new antitumor compounds with high potency, 26 analogues have been synthesized. In pharmacological tests most of them showed antitumor activities in vitro, some of them are significant.

We studied the effects of different cytokine combinations and umbilical cord blood preserved at 4 degrees C for 4 days on the growth of CFU-GM and HPP-CFC. The results showed that the growth of umbilical cord blood CFU-GM was markedly different when various combinations of cytokines were used. After 2 weeks culturing with IL-3 alone or plus GM-CSF, the number of umbilical cord blood CFU-GM was increased when compared with GM-CSF group; upon stimulation with GM-CSF plus IL-3 plus IL-6 plus Epo, a significant increase of umbilical cord blood CFU-GM was seen. After umbilical cord blood being preserved 4 days at 4 degrees C, the number of umbilical cord blood CFU-GM and HPP-CFC was decreased.

To evaluate the composition and proportion of the hematopoietic stem cells in peripheral blood (PB) and bone marrow (BM) in paroxysmal nocturnal hemoglobinuria (PNH) patients.

We have constructed pSG5-RAR gamma-neo plasmid containing mouse retinoic acid receptor gamma (RAR gamma) gene and neo gene, and introduced it into embryonic stem ES-5 cells, by calcium phosphate mediated transfection. Some G418-resistant clones were isolated and from RNA dot blot analysis of these clones, a clone overexpressing RAR gamma gene was established, designated as ES-gamma cell line. Northern blot hydridization and Southern blot hydridization analysis of ES-gamma cells (Fig 3, 4) demonstrated that ES-gamma cells overexpressed exogenous RAR gamma mRNA and the exogenous RAR gamma cDNA integrated into the genome of ES cells. ES-gamma cells retained undifferentiated morphology and positive alkaline phosphatase activity (Plate I, Fig. 1, 2), so it resembled ES-5 cells in terms of stem cell characteristics. When ES-gamma cells were subcutaneously inoculated into nude mouse and differentiated in vivo, tumorous nodules containing various tissue structures were obtained, demonstrating their pluripotent properties just like parent ES-5 cells. Contrasting with ES-5 cells, the histological features of tumors showed no cartilage tissues, but abundant muscle tissues and keratinized cyst like structures constituted by stratified squamous epithelia (Plate I, Fig. 3). Differentiating in vitro by hanging drop culture methods, ES-gamma cells differentiated mostly into fibroblast-like cells, (Plate II, Fig. 1-5). The above results indicated that overexpression of RAR gamma gene changed the cell type of ES cells differentiating in vivo and in vitro. During the differentiation of ES-5 cells induced by RA, a large number of cells rounded up, detached from the dish and tended to die. We suspected that this phenomenon may be apoptosis. The ultrastructure appearance of the dying cells displayed typical apoptotic changes including chromatin condensation and nuclear fragmentation (Plate I, Fig. 4, 5). Detection of DNA fragments using agarose gel electrophoresis showed characteristic laddered patterns of apoptotic DNA fragments (Fig. 5). The above results indicated that RA induced apoptosis of ES-5 cells in the course of differentiation. The percentage of apoptosis of ES-5 cells increased accordingly, with the increase of RA concentration (Fig. 6). With the same concentration of RA 10(-7) mol/L, the percentage of apoptotic of ES-gamma death was roughly one times more than that of ES-5 cells (Fig. 7), a fact indicating that RAR gamma may mediate the apoptotic signal transduction of ES cells by RA.

DNA, RNA and PRO comprise the bulk of macromolecules in cells, which have been proven to play an important role in regulating cell cycle transverse capacity, cell division, growth, and size. Simultaneous analysis of these moieties could provide more comprehensive and accurate information on cell cycle kinetics. In this study, DNA, RNA and PRO contents related to cell cycle kinetics in CD34+ hematopoietic cells of human bone marrow were measured to understanding the cell cycle kinetic features in CD34+ hematopoietic cells. For this reason, CIMS-100 immunomagnetic isolator, a novel isolation system, was used to enrich efficiently CD34+ hematopoietic cells from human bone marrow. The purity of enriched CD34+ hematopoietic cells determined by both FACS and APAAP staining is ranging from 90%-95%. Cellular DNA, RNA and PRO were stained with fluorochromes propidium iodide, pyronin Y and fluorescein isothiocyante respectively The fluorescence intensities reflecting the DNA, RNA and PRO content of individual cell were analyzed in FACS can by different excitation wavelengthes. DNA, RNA and PRO contents in CD34+ hematopoietic cells were far lower than these of bone marrow mononuclear cells, only being 34 +/- 3% (DNA), 48 +/- 21% (RNA) and 62 +/- 14% (PRO) of BMMNCs respectively. Collectively, these data combined with previous results from both ours and others indicated that CD34+ hematopoietic cells are indeed an unique cell population, not only in reconstitute of hematopoietic and immunological functions, but also in cell cycle kinetics. This is, to our knowledge, the first detailed report on the analysis of DNA, RNA and PRO contents related to cell cycle kinetics in CD34+ hematopoietic cells. And the results provide more direct evidence that the majority of CD34+ hematopoietic cells are in resting state.

Leukemia inhibitory factor (LIF) has the ability to maintain the development potential of pluripotent embryonic stem cells, suggesting that this factor might play an important role during mouse embryogenesis. By whole mount in situ hybridization on early mouse embryos, we have examined the expression pattern of the LIF gene from the two cell stage to the preimplantation blastocyst with the following results. (1) LIF transcripts were detected at all stages before implantation, but the highest level of LIF mRNA expression occurred in the blastocyst stage. (2) For the cleavage stages of mouse embryo, there was no significant distinction of the LIF gene expression level between blastomeres, but a strong signal was detectable in the cells which surrounded the blastocoel cavity of the blastocyst and most of them belonged to future extraembryonic tissues. These results suggest that a principal function of LIF in vivo may be to regulate stem cell population and to play an important role in the implantation of the blastocyst.

To increase myeloid progenitors resistance to chemotherapy and prevent myelosuppression caused by alkylating agents.

To study the effects of cryopreservation length on the proliferative potential of hematopoietic cells derived from cord blood.

To investigate the feasibility of chondrogenic phenotype differentiation of adult swine bone marrow stem cells(MSCs) in a defined medium as seeding cells in cartilage tissue engineering.

The effect of trypsin on the separation an subculture of the keratinocytes was investigated in this work. It was found that when 0.25% trypsin was employed for 5 minutes to separate keratinocytes, the number of active keratinocytes and the cells capable of forming colony were higher than those of other experimental conditions. The maximum attached ratio of primary keratinocytes was obtained when skin tissues were treated at 0.05% concentration of trypsin. With the increase of the trypsin concentrations, the attached ratio, attachment rate constant, and colony forming efficiency were all increased. Thus, 0.25% concentration of trypsin was recommended for separating and subculturing the keratinocytes.

To elucidate the effects of hypoxia on the proliferation and differentiation of CD34(+) hematopoietic stem/progenitor cells and their response to cytokines, the cells were isolated from umbilical cord blood by using a high-gradient magnetic cell sorting system (MACS). Mononuclear cells (MNC) and CD34(+) cells were incubated in severe hypoxia (1% oxygen) culture system, and the colony forming cells and antigen expression were studied by colony forming assays and FACS analysis. The results showed that incubation in severe hypoxia increased the number of erythroid bursts (BFU-E) (324.8+/-41.4/10(4) cells) generated from CD34(+) cells (191.2+/-34.5/10(4) cells in the control group, P<0.01). Severe hypoxia also enhanced the maintenance and cloning efficiency of BFU-E in a liquid culture system without growth factors, the number of BFU-E (152.4+/-22.6/10(4)cells) was much bigger than that in the control group (74.2+/-9.3/10(4) cells, P<0.01). In cultures incubated in hypoxia, the percentage of CD34(+) cells was significantly higher (2.5+/-1.2-fold, P<0.05) than in those incubated in air. BFU-E cloning efficiency of MNC was not significantly affected by hypoxia. The above results show that hypoxia enhances the maintenance of erythroid progenitor cells generated from CD34(+) hematopoietic stem/progenitor cells, no matter growth factors are present or not. These positive effects of hypoxia did not occur for the other progenitors.

To investigate the growth properties of hematopoietic progenitor/stem cells in umbilical cord blood (CB) of second trimester, third trimester, and term fetuses.

To evaluate the effect of immunomagnetic technique in purging of peripheral blood progenitor cell (PBPC) of breast cancer patients.