[Analysis of T lymphocyte absolute number and function in the early phase after haploidentical hematopoietic stem cell transplantation].

This study was purposed to investigate the immune reconstitution of T-cells in patients who received haploidentical hematopoietic stem cell transplantation (hiHSCT). The peripheral blood was harvested from 22 patients before transplantation and at month 1, 3, 6 after hiHSCT. The proportions of T lymphocyte subtypes including CD3(+), CD4(+), CD8(+), CD45RO(+), and CD45RA(+)CD62L(+) were analyzed by flow cytometry, followed by the calculation of T cell numbers according to the amounts of peripheral blood leukocytes. Adenosine triphosphate (ATP) value in CD4(+) T cells was measured by ImmuKnow method to evaluate the function of lymphocytes. The results showed that the CD3(+) cell absolute value before transplantation was 833.75 ± 359.84/µl, but those values at month 1, 3, 6 after transplantation were 318.87 ± 266.71/µl, 1006.76 ± 512.32/µl and 1296.38 ± 958.77/µl respectively. The CD4(+) cell absolute value before transplantation was 336.99 ± 211.11/µl, but such values at month 1, 3, 6 after transplantation were 45.89 ± 44.21/µl, 142.97 ± 114.85/µl, and 181.78 ± 120.61/µl respectively. The CD8(+) cell absolute value before transplantation was 430.21 ± 159.48/µl, but those values at month 1, 3, 6 after transplantation were 230.44 ± 195.89/µl, 621.64 ± 318.83/µl, and 823.07 ± 633.55/µl respectively. The CD4(+)CD45RO(+) memory T cell absolute value before transplantation was 227.44 ± 73.34/µl, but such values at month 1, 3, 6 after transplantation were 43.47 ± 43.40/µl, 138.69 ± 110.17/µl, 147.73 ± 82.94/µl respectively. The CD8(+)CD45RO(+) memory T cell absolute value before transplantation was 212.70 ± 98.48/µl, but such values at month 1, 3, 6 after transplantation were 184.76 ± 168.65/µl, 445.90 ± 252.50/µl, 519.80 ± 475.53/µl respectively. CD4(+)CD45RA(+)CD62L(+) naive T cell number before transplantation was 68.94 ± 59.74/µl, but such cell numbers at month 1, 3, 6 after transplantation decreased to 2.44 ± 2.93/µl, 3.14 ± 3.48/µl, 23.22 ± 38.38/µl respectively. The CD8(+)CD45RA(+)CD62L(+) naive T cell absolute value before transplantation was 124.82 ± 60.95/µl, but those values at month 1, 3, 6 decreased to 19.37 ± 17.71/µl, 76.63 ± 50.85/µl, and 114.49 ± 174.29/µl respectively. The ATP value in CD4(+) T cells decreased to 210.19 ± 119.37 ng/ml at month 1 after transplantation and increased to 280.62 ± 110.03 ng/ml at month 3, and 357.28 ± 76.18 ng/ml at month 6 after transplantation. It is concluded that CD8(+) memory T cell reconstruction contributes critically to T cell recovery early after hiHSCT, while the thymic output function remains low. However, T cell function recovers to normal range at month 3 after transplantation.

[Therapeutic effects and the underlying mechanism of umbilical cord-derived mesenchymal stem cells for bleomycin induced lung injury in rats].

OBJECTIVE: To study the efficacy of umbilical cord-derived mesenchymal stem cells (UC-MSCs) for bleomycin-induced pulmonary fibrosis in mice. METHODS: UC-MSCs were isolated from the umbilical cord after parental consent. One hundred C57BL/6 mice were randomly divided into 4 groups (12 of these for preliminary experiment). Mice in the control group (n = 20) were instilled with PBS via trachea and NS was injected via the tail vein after 3 days. Mice in the stem cell group (n = 20) were instilled with PBS via trachea and were injected with MSC via the tail vein after 3 days. Mice in the bleomycin group (n = 24) were instilled with bleomycin via trachea and NS was injected via the tail vein after 3 days. Mice in the bleomycin plus stem cell group (n = 24) were instilled with bleomycin via trachea and were injected with MSCs via the tail vein after 3 days. All of the mice were sacrificed at the 21(th) day, and the lungs were immediately fixed with 4% paraformaldehyde for 48 h, embedded in paraffin and sectioned at 5 µmol/L thickness. The sections were stained with hematoxylin and eosin (H&E) and Masson-trichrome. Histopathological scoring of pulmonary fibrosis was performed according to Ashcroft's method. The concentrations of matrix metalloproteinases-2 and tissue inhibitor of metalloproteinase-1were determined using immunohistochemistry. RESULTS: Compared with the bleomycin group, MSC transplantation significantly reduced pulmonary inflammation, fibrosis and deposition of collagen in the bleomycin plus stem cell group [(1.55 ± 0.51) vs (2.16 ± 0.77), and (1.45 ± 0.60) vs (2.32 ± 0.82), respectively, P < 0.05]. There was no difference between the control group and the stem cell group [(0.35 ± 0.49) vs (0.37 ± 0.50), P > 0.05]. The expression of MMP-2 in the bleomycin plus stem cell group was lower than the bleomycin group [(1.59 ± 0.59) vs (2.37 ± 0.68), P < 0.05], but there was no difference between the control group and the stem cell group [(0.80 ± 0.69) vs (0.84 ± 0.77), P > 0.05]. The expression of TIMP-1 in the bleomycin plus stem cell group was higher than the bleomycin group [(1.95 ± 0.58) vs (0.79 ± 0.71), P < 0.05], but there was no difference between the control group and the stem cell group [(1.10 ± 0.72) vs (1.32 ± 0.58), P > 0.05]. CONCLUSION: UC-MSC transplantation could relieve bleomycin-induced fibrosing alveolitis in mice. The mechanism might be related to the expression of MMP-2 and TIMP-1. UC-MSC had no effect on normal lungs.

Keratinocyte growth factor gene therapy ameliorates ulcerative colitis in rats.

AIM: To investigate the effect of keratinocyte growth factor (KGF) gene therapy in acetic acid-induced ulcerative colitis in rat model. METHODS: The colitis of Sprague-Dawley rats was induced by intrarectal infusion of 1 mL 5% (v/v) acetic acid. Twenty-four hours after exposed to acetic acid, rats were divided into three experimental groups: control group, attenuated Salmonella typhimurium Ty21a strain (SP) group and SP strain carrying human KGF gene (SPK) group, and they were separately administered orally with 10% NaHCO(3), SP or SPK. Animals were sacrificed and colonic tissues were harvested respectively on day 3, 5, 7 and 10 after administration. Weights of rats, colonic weight/length ratio and stool score were evaluated. Histological changes of colonic tissues were examined by hematoxylin and eosin (HE) staining method. The expression of KGF, KGF receptor (KGFR) and TNF-α were measured either by enzyme-linked immunosorbent assay or Western blotting. Immunohistochemistry was used to detect the cellular localization of KGFR and Ki67. In addition, superoxide dismutase (SOD) activity and malondialdehyde (MDA) contents in the homogenate were measured. RESULTS: Body weight and colonic weight/length ratio were declined in SPK group compared with SP and control groups (body weight: 272.78 ± 17.92 g vs 243.72 ± 14.02 g and 240.68 ± 12.63 g, P < 0.01; colonic weight/length ratio: 115.76 ± 7.47 vs 150.32 ± 5.99 and 153.67 ± 5.50 mg/cm, P < 0.01). Moreover, pathological changes of damaged colon were improved in SPK group as well. After administration of SPK strain, KGF expression increased markedly from the 3rd d, and remained at a high level till the 10th d. Furthermore, KGFR expression and Ki67 expression elevated, whereas TNF-α expression was inhibited in SPK group. In the group administered with SPK, SOD activity increased significantly (d 5: 26.18 ± 5.84 vs 18.12 ± 3.30 and 18.79 ± 4.74 U/mg, P < 0.01; d 7: 35.48 ± 3.35 vs 22.57 ± 3.44 and 21.69 ± 3.94 U/mg, P < 0.01; d 10: 46.10 ± 6.23 vs 25.35 ± 4.76 and 27.82 ± 6.42 U/mg, P < 0.01) and MDA contents decreased accordingly (d 7: 7.40 ± 0.88 vs 9.81 ± 1.21 and 10.45 ± 1.40 nmol/mg, P < 0.01; d 10: 4.36 ± 0.62 vs 8.41 ± 0.92 and 8.71 ± 1.27 nmol/mg, P < 0.01), compared with SP and control groups. CONCLUSION: KGF gene therapy mediated by attenuated Salmonella ameliorates ulcerative colitis induced by acetic acids, and it may be a safe and effective treatment for ulcerative colitis.

Experimental investigation of HGF inhibiting glial scar in vitro.

To study the inhibitory effect of Hepatocyte growth factor (HGF) on the responsive hyperplasia of damaged astrocytes in vitro. We prepared damaged model of astrocytes to simulate the responsive hyperplasia of damaged astrocytes in vivo by culturing astrocytes in vitro; After the first day of Ad-HGF transfection, astrocytes were scratched, then after the first, the third, and the fifth day of scratch, we detect the expression amount of astrocytes specific glial fibrillary acidic protein (GFAP) and the ratio of S-phase cells with flow cytometry, both of which can reflect the proliferation status of damaged astrocytes; After HGF was added in scratched astrocytes, the activity of SPK and MAPK (P42/44) were detected by autoradiography and immunoblotting test; After adding different concentrations of HGF protein in astrocytes cultured in different serum concentrations and adding diverse concentrations of HGF protein, SPK and SPK inhibitor DMS in scratched astrocytes, we detect cell proliferation with 3H-TDR incorporation. The first day after Ad-HGF transfected astrocytes were scratched, the amount of GFAP secreted by astrocytes were decreased significantly (P < 0.05), and the cells in S phase were declined obviously. HGF has bidirectional regulation on SPK of scratched astrocytes: increases the SPK activity when HGF in low dose, while inhibits when in high dose. In addition, DMS can block the signal passage; HGF had no effects on MAPK (P42/44) of damaged astrocytes cells. In conclusion, after the transfection of Ad-HGF, it can inhibit the responsive hyperplasia of damaged astrocytes by the means of blocking SPK passage.

[Advances of research on autophagy regulation in leukemia cells].

Autophagy is a conservative self-degradation system in eukaryotic cells, which involves in multiple physiologic and pathologic processes. Autophagosome is a typical characteristics of autophagic process, and its formation and degradation are the key points to control autophagy. Due to its dual characteristics to promote survival and death, to some extent, autophagy determines cell fate for survival or die. Autophagy plays important roles in cancer development, metastasis and drug-resistance. Thus targeting autophagy may provide novel strategies for treating cancer and overcoming drug resistance. With the advances of study on autophagy regulation in leukemia cells, the novel therapeutic targets and strategies to cure leukemia will be developed. This review focuses autophagy characteristics and regulation, autophagy and tumor, autophagy and leukemias as well as autophagy regulation in leukemia cells.

Hepatocyte growth factor plays a critical role in the regulation of cytokine production and induction of endothelial progenitor cell mobilization: a pilot gene therapy study in patients with coronary heart disease.

1. There is growing evidence of the beneficial effects of hepatocyte growth factor (HGF) in myocardial infarction, heart failure and occlusive peripheral arterial disease. The aim of the present study was to evaluate the effects of intracoronary administration of an adenovirus vector encoding the human HGF gene (Ad-HGF) on serum levels of cytokines and mobilization of CD34(+) and CD117(+) cells in patients with coronary heart disease. 2. Twenty-one patients with severe coronary artery disease were recruited to the study: 11 patients received both a stent and administration of Ad-HGF; the remaining 10 patients received a stent alone and served as the control group. Blood samples were obtained from the femoral vein before and then 6 and 24 h, 3 and 6 days and 2 weeks after treatment for the isolation of serum and peripheral blood mononuclear cells. Intracoronary administration of Ad-HGF in patients with coronary heart disease resulted in high levels of HGF gene expression, as well as its receptor c-met, compared with the control group, as demonstrated by real-time reverse transcription-polymerase chain reaction. In addition, serum levels of HGF, vascular endothelial growth factor, monocyte chemoattractant protein-1 and interleukin (IL)-10 were increased and serum levels of IL-8 were decreased in patients administered Ad-HGF compared with the control group. The percentage of CD34(+) and CD117(+) cells in the peripheral blood increased in patients administered Ad-HGF. 3. In conclusion, HGF gene therapy may play an important role in the regulation of cytokines and the induction of endothelial progenitor cell mobilization in patients with coronary heart disease.

[Producing recombinant adenovirus encoding green fluorescent protein (Ad-GFP) by suspension cultured HEK-293 N3S cells].

Adenovirus vectors are one of the most promising gene transfer systems. They are of great value for gene therapy because these vectors achieve temporal high-level transgene expression and high gene transfer efficiency. To meet increasing needs of adenovirus vectors for gene therapy programs, parallel development of efficient, scalable and reproducible production processes is required. Perfusion cultivation of 293 cells is one of the most commonly used methods to produce adenovirus vectors and it is suitable for industrialized production specially. Experimental studies had been carried out to produce recombinant adenovirus containing the green fluorescent protein gene (Ad-GFP) by perfusion cultivation of HEK-293 N3S cells in a 5L stirring bioreactors. Perfusion rate was 1-2 volume/day. To infect the 293 N3S cells with Ad-GFP at the density of (2-4) x 10(6) cells/ ml. The time of collecting cells was 48 hours post infection. After three rounds of freeze/thaw and centrifugation, the crude viral lysates were stored at--80 degrees C until use. Then to get the Ad-GFP products by 2 x CsCl-gradient purification. The purity of the products was determined by the A260/A280 ratio and a high performance liquid chromatography (HPLC) assay. The infective titer was determined by a TCID50 assay. The culture term was 10-12 days. The infectious titer, the number of virus particle and the ratio of infectious titer to virus particle for the product were 1.0 x 10(11) IU/mL, 1.68 x 10(12) VP/mL and 6.0% IU/VP respectively. The A260/A280 ratio was 1.33, and the purity determined by HPLC was 99.2%. The cell specific productivity was around 1000 IU/cell. By perfusion cultivation of 293 N3S cells in a 5L stirring bioreactors, we established the production process for Ad-GFP, which paves a way to produce other recombinant adenovirus for gene therapy.

[Effect of intracoronary adenovirus vector encoding hepatocyte growth factor gene on hematopoietic stem cells mobilization in patients with extensive coronary heart disease].

OBJECTIVE: To investigate the effect of intracoronary adenovirus vector encoding hepatocyte growth factor gene (Ad(5)-HGF) on hematopoietic stem cells mobilization in patients with extensive coronary heart disease. METHODS: Patients with extensive coronary heart disease were treated with intracoronary infusion of adenovirus vector encoding hepatocyte growth factor (Ad(5)-HGF 5 x 10(9) pfu) gene plus stent implantation (n = 9) or equal physiological saline plus stent implantation (n = 9). Angioplasty and stent implantation was performed according to standard clinical practice by the femoral approach and blood samples were drawn from each patient at baseline before PCI, 6 to 24 hours and 6 days post procedure. The number of CD34(+), CD38(+) and CD117(+) cells in peripheral blood was analyzed by flow cytometer. RESULTS: The number of circulating CD34(+) cells in Ad(5)-HGF gene treatment group 6 hours after procedure and the number of circulating CD117(+) cells 6 days post procedure were significantly higher in Ad(5)-HGF gene treatment group than those in the control group (0.104 +/- 0.082 vs. 0.022 +/- 0.012, P = 0.021) and (0.058 +/- 0.058 vs. 0.012 +/- 0.009, P = 0.034), respectively. CONCLUSION: Intracoronary administration of Ad(5)-HGF could mobilize hematopoietic stem cells into peripheral blood and the consequent role of this observation on myocardial regeneration warrants further detailed studies.

[Construction and expression of a fusion protein made of tissue-type plasminogen activator and hirudin in Pichia pastoris].

To combine the fibrinolytic with anticoagulant activities for therapy of thrombotic deseases, a fusion protein made of tissue-type plasminogen activator (t-PA) and hirudin was constructed and expressed in chia pastoris. To improve thrombolytic properties of t-PA and reduce bleeding side effect of hirudin, FXa-recognition sequence was introduced between t-PA and hirudin molecules.The anticoagulant activity of hirudin can be target-released through cleavage of FXa at thrombus site. t-PA gene and hirudin gene with FXa-recognition sequence at its 5'-terminal were obtained by RT-PCR and PCR respectively. The fusion protein gene was cloned into plasmid pIC9K and electroporated into the genome of Pichia pastoris GS115. The expression of fusion protein was induced by methanol in shaking flask and secreted into the culture medium. Two forms of the fusion protein, single-chain and double-chain linked by a disulfide bond (due to the cleveage of t-PA at Arg275-Ile276), were obtained. The intact fusion protein retained the fibrinolytic activity but lacked any anticoagulant activity. After cleavage by FXa, the fusion protein liberated intact free hirudin to exert its anticoagulant activity. So, the fusion protein is a bifunctional molecule having good prospect to develop into a new targeted therapeutic agent with reduced bleeding side effect for thrombotic diseases.

[The induction apoptosis of HL-60 cells by low molecular weight compounds of taurine, ornithine and carnosine from new born calf liver].

AIM: Clinical studies stated that low molecular weight compounds (< 1.0 kd) extracted from the new born calf liver could effectively inhibit the proliferation of tumor cells. In this report, we observed inhibition effects and their regulative mechanisms of taurine, ornithine, carnosine on the proliferation of HL-60 cells. METHODS: Three active ingredients, i.e., taurine, ornithine and carnosine were separated by ion-exchange chromatographic column and identified from the low molecular weight filtrate of new born calf liver. MTT assay was used to test the survival rate of HL-60 cells and normal lymphocytes treated by the three ingredients. The various effects of the three compounds on HL-60 cells were respectively evaluated by agarose gel electrophoresis, ESR and immunohistochemical methods. RESULTS: These compounds effectively inhibited the proliferation of HL-60 cells and induced apoptosis which was determined by apoptotic changes in morphology and nuclear DNA degradation. Whereas no inhibition effects on normal lymphocytes were observed. In addition, the results of ESR showed that the activity of oxygen radical within HL-60 cells treated with there compounds decreased to trace level. Furthermore, in the immunohistochemical experiments, we found that the level of p45/skp2 in HL-60 cells decreased while the level of p27/kip increased. CONCLUSION: The taurine, ornithine and carnosine compounds can selectively suppress tumor cells proliferation by regulating the level of cell cycle proteins.

[Establishment of a method for determining the sphingosine kinase activity and its initial application].

AIM: To establish the methods for determining the activity of sphingosine kinase(SPK) and the content of sphingosine 1-phosphate (S1P) in biological samples. METHODS: The ECV304 cells were transfected with pcDNA3 vector encoding Flag-labeled SPK gene. The expression of SPK was measured by Western blot assay and the activity of SPK was determined by enzymatic reaction, isotope incorporation and thin-layer chromatography methods. The S1P in biological samples was extracted, digested by alkaline phosphatase and then catalyzed by SPK. The S1P contents were determined according to the amounts of products. RESULTS: SPK gene transfection could enhance the expression and activity of SPK in cells markedly, and the cellular S1P was also increased obviously. HGF stimulation could increase the activity of SPK and cellular S1P in ECV304 cells. CONCLUSION: Methods for determining the activity of SPK and the content of SPK in biological samples were established.

[Influence of hepatocyte growth factor on biological characteristics of bone marrow-derived mesenchymal stem cells].

Hepatocyte growth factor (HGF) is one of major growth factors in the bone marrow microenvironments with which the proliferation, differentiation and migration of bone marrow-derived mesenchymal stem cells were closely contacted. However, its roles in the regulation of proliferation, differentiation and migration of bone marrow-derived mesenchymal stem cells remain unclear. This study was aimed to investigate the effect of HGF on biological characteristics of bone marrow-derived mesenchymal stem cells. Expression of c-Met, the receptor for HGF was detected by immunohistochemistry assay, cell proliferation was determined by MTT, activity of ALP was quantitatively assayed, cell migration and anoikis-induced MSC apoptosis were analyzed. The results showed that HGF not influenced the proliferation and osteogenic differentiation of bone marrow-derived mesenchymal stem cells. Treatment of bone marrow-derived mesenchymal stem cells with recombinant human hepatocyte growth factor resulted in inhibition of anoikis-induced apoptosis. HGF significantly stimulated the migration of bone marrow-derived mesenchymal stem cells. Both PI-3 kinase and MAPK kinase were proved to be involved in HGF-induced migration. It is concluded that HGF/c-Met signal regulates the apoptosis and migration of bone marrow-derived mesenchymal stem cells.

[Plasmid pUDKH gene therapy of rat acute hindlimb ischemia: an experimental study].

OBJECTIVE: To investigate the effect of plasmid pUDKH carrying human hepatocyte growth factor (HGF) gene on rat acute limb ischemia and to find the lowest effective dosage. METHODS: Ligation of femoral artery of one hindlimb in Wistar rats was performed. The rats were randomly divided into 5 groups of 10 rats: pUDKH 50 microg, 100 microg, 200 microg, and 400 microg groups and a vacant vector pUDK group (control group). The plasmids were injected once directly into the ischemic limb muscle (5 sites around ligation position) immediately after ligation. At day 10, the muscles were removed and stained with H.E. to assess histologically the blood vessel formation. HGF expression was detected in the muscle tissue of another 12 rats on days 3, 5, 10, 14, 21, 30 after injection of pUDKH or pUDK, 200 microg each per animal. RESULTS: HGF expression was detected clearly in muscle tissue on days 3, 5, 10, 14 in pUDKH groups. In HGF-transfected animals (except for 50 microg group) neoformation of blood vessels in muscles and soft tissues was found, while it was not seen in controls. By semi-quantitation of the degree of vessel formation, significant differences between pUDKH groups (0.96 +/- 0.07, 1.97 +/- 0.91, 2.26 +/- 1.00 for 100 microg, 200 microg, 400 microg, respectively) and the control group (0.27 +/- 0.04) (P < 0.05) were noted. In addition, injection of pUDKH could alleviate the severity of degeneration of muscular tissue due to ischemia. CONCLUSION: Human HGF gene therapy is effective in treating rat acute limb ischemia with the lowest effective dose of 100 microg.

Synergetic anticancer effect of combined quercetin and recombinant adenoviral vector expressing human wild-type p53, GM-CSF and B7-1 genes on hepatocellular carcinoma cells in vitro.

AIM: This study investigated the anti-cancer effect of combined quercetin and a recombinant adenovirus vector expressing the human p53, GM-CSF and B7-1 genes (designated BB-102) on human hepatocellular carcinoma (HCC) cell lines in vitro. METHODS: The sensitivity of HCC cells to anticancer agents was evaluated by 3-(4,5- dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay. The viability of cells infected with BB-102 was determined by trypan blue exclusion. The expression levels of human wild-type p53, GM-CSF and B7-1 genes were determined by Western blot, enzyme-linked immunosorbent assay (ELISA) and flow cytometric analysis, respectively. The apoptosis of BB-102-infected or quercetin-treated HCC cells was detected by terminal deoxynucleotidyl transferase (TdT) assay or DNA ladder electrophoresis. RESULTS: Quercetin was found to suppress proliferation of human HCC cell lines BEL-7402, HuH-7 and HLE, with peak suppression at 50 micromol/L quercetin. BB-102 infection was also found to significantly suppress proliferation of HCC cell lines. The apoptosis of BB-102-infected HCC cells was greater in HLE and HuH-7 cells than in BEL-7402 cells. Quercetin did not affect the expression of the three exogenous genes in BB-102-infected HCC cells (P>0.05), but it was found to further decrease proliferation and promote apoptosis of BB-102-infected HCC cells. CONCLUSION: BB-102 and quercetin synergetically suppress HCC cell proliferation and induce HCC cell apoptosis, suggesting a possible use as a combined anti-cancer agent.

[Studies of protective effect of SOD on damage of human RBCs stored at 4 degrees C].

AIM: To investigate the mechanism of protective effect of SOD (superoxide dismutase) on damage of RBCs stored at 4 degrees C, the studies of erythrocyte glucose and energy metabolism were performed. METHODS: whole blood collected from healthy donors and stored at 4 degrees C in ACD, GMA and SOD solutions. Before and post storage, some parameters were assayed. Standard methods were used for the in vitro tests. The 24-hour in vivo recoveries were measured by FTTC (Fluorescein 5-isothiocyanate) from SIGMA Company. RESULTS: All parameters of red blood cell glucolysis rate without oxygen condition, ATP, PK (pyruvic kinase) and 24 h recoveries level were 86.2%, 56.4%, 64.3% and 86.2% of normal respectively stored in SOD solution at 4 degrees C for 75 days, distinctly more than in ACD and GMA groups at 75 days stored. The 24 h recovery at 75d in group SOD was near the recovery at 42d in group GMA. CONCLUSION: Whole blood in SOD solution can be stored satisfactorily for 75 days at 4 degrees C, and furnished theoretical evidence for RBCs survival.

[Study on construction of a plasmid vector carrying human hepatocyte growth factor gene and activity of its expression product].

AIM: To construct a plasmid carrying hepatocyte growth factor gene and investigate its effects in vitro. METHODS: A complementary DNA (cDNA) clone for human HGF was isolated from human placental cDNA, then subcloned into pUDK vector, which was constructed by ourselves, to form the pUDKH plasmid. The transfection efficiency and the expression level of HGF and VEGF were evaluated by transfecting pUDK or pUDKH into primary rat skeletal muscle cells. The biological effects of HGF-expressing product at different doses on endothelial cells were investigated in vitro, and assessed by MTT. RESULTS: The primary rat skeletal muscle cells could be transfected efficiently with pUDKH (0.057%), and secreted HGF(16 -18 ng/4 x 10(5) cells) and VEGF proteins. The expressing product could significantly stimulate proliferation of human umbilical vein endothelial cells, in a dose-dependent manner (P < 0.05). CONCLUSION: pUDKH has the potential application in vivo to treat ischemic diseases.

[New tactics of human red blood cells stored at 4 degrees C-protective effect of antioxidant solution on red blood cells damage].

Aliquots of venous blood from healthy donor were collected in plastic blood storage bags with ACD, GMA or antioxidant solution (superoxide dismutase, SOD), respectively, and stored at 4 degrees C. After storage for varying periods, the parameters of the blood were detected in the blood samples. Results showed that the parameters of the blood stored at 4 degrees C for 75 days in SOD group were following: the recovery of RBC-Hb was 87.2%, plasma-Hb (mg/L) was 193.2, P50 (mmHg) was 34.0 (normal value was 33.1); deformability (DImax) was 0.2413 (74.3% of normal value). There was no evident hemolysis, color change, air bubble and clots. It was concluded that human RBC stored at 4 degrees C for 75 days with SOD solution, recovery of levels of RBC-Hb and plasma-Hb were accorded with the requirements of "Basic Demands of Blood Station" in China.

Partial isolation and identification of hepatic stimulator substance mRNA extracted from human fetal liver.

AIM:To partially isolate and identify hepatic stimulator substance mRNA from human fetal liver tissues.METHODS:The poly (A)mRNA was extracted from human fetal liver tissues of 4-5 month gestation, fractionated by size on sucrose gradient centrifugation, translated into protein from each fraction in vitro and then its products were tested for HSS activity.RESULTS:Twenty-two 500 total RNA was obtained from human fetal liver tissues and pooled.mRNA of 420 was yielded,processed by oligo(dT)-cellulose column chromatography, then was size-fractionated by ultracentrifution on a continuous sucrose density gradient (5%-25%), and separated into 18 fractions.Translated products of mRNA in fraction 8 and 9 could produce a two-fold increase in the incorporation of( 3)H-TdR into DNA of SMMC-7721 hepatoma cells and in a heat resistant and organ-specific way.CONCLUSION:The partially purified HSS mRNA was obtained and this would facilitate the cloning of HSS using expression vectors.

Expression and Activity of Recombinant Human Augmenter of Liver Regeneration.

The cDNA of human augmenter of liver regeneration was subcloned onto the downstream of the P(R)P(L) promoter of the expression plasmid pBV220. The recombinant plasmid could stably express ALR with high efficiency (up to 20% of the total bacterial proteins) in E. coli through thermal induction. The expressed recombinant ALRs could produce a significant increase in the incorporation of (3)H-TdR into liver DNA of a 1/3 hepatectomized test animal and also had a potent antihepatitis effect. These results suggest that ALR appears to be an important regulator of liver regeneration and may be used in clinical trial for enhancing liver regeneration in the treatment of hepatic diseases.