Biomedical subjects

J Chen

Publications and source records attributed to J Chen.

At least 613 records · Page 34Linked to original sources

PubMed2001

[Enzymatic conversion of cephalosporin C to glutaryl-7-aminocephalosporanic acid using whole cells of the yeast Trigonopsis variabilis FA10].

A process for the production of glutaryl-7-aminocephalosporanic acid (GL-7ACA) from cephalosporin C(CPC) using permeabilized cells of yeast Trigonopsis variabilis FA10 containing D-amino acid oxidase (DAO) is described. It was found that the bioconversion of CPC to GL-7ACA was interfered by the catalase activity presented in the cells that hydrolyzed the hydrogen peroxide and resulted in the accumulation of alpha-keto-adipyl-7-ACA (AKA-7ACA) and decrease of GL-7ACA yield. the methods to overcome this problem including the addition of extra H2O2 and use of catalase inhibitor, NaN3, were developed and the rate of GL-7ACA from CPC were 73% and 70.1%, respectively. Another alternative method was to incubate the permeabilized FA10 cells at pH10.5-11.0 for 30 minutes at 20 degrees C which served to selectively inactivate the catalase. In the bioconversion of CPC to GL-7ACA using pH10.5-treated cells without catalase activity, the high reaction yield of GL-7ACA(84%) was achieved.

Cephalosporins↗

PubMed2001

[Effects of interferon-alpha on recurrence and metastasis of hepatocellular carcinoma after curative resection in nude mice].

OBJECTIVE: To study the effect of interferon-alpha (IFN-alpha) on the recurrence and metastasis of hepatocellular carcinoma (HCC) in nude mice, and to clarify if there is synergistic effect treated by combination of IFN-alpha and all-trans retinoic acid (ATRA). METHODS: The effect of IFN-alpha and/or ATRA on the proliferation of HCC cell lines was measured in vitro. The metastatic model of human HCC in nude mice LCI-D20 was used in present study. Curative resection was performed at 10th day after implantation in 44 nude mice. Drugs were given at the next day after resection. IFN-alpha was administered subcutaneously at doses of 3+/-10(5) U/day, 6+/-10(5) U/day, respectively. ATRA was administered p.o. at a dose of 20 mg/kg/day, and IFN-alpha 6+/-10(5)U/day combined with ATRA 20 mg/kg/day. The mice were sacrificed 35 days after treatment. The recurrent tumor size was measured and the presence of intrahepatic dissemination and lung metastases were recorded. RESULTS: The effect of IFN-alpha and/or ATRA on the proliferation of HCC cells SMMC7721, BEL-7402, BEL-7405, and MHCC97 was not obvious. The combination of IFN-alpha and ATRA had no synergistic effect in vitro. The lung metastatic rate, the liver recurrent rate, the size of main recurrent lesions, the number of intrahepatic disseminating nodules and the largest disseminating nodule of the controlled group was 100%(12/12), 100%(12/12), (1346.3+/-4.2 ) mm(3), 8.2+/-4.4, 864 mm(3), respectively; whereas it was 0, 87.5%(7/8), (8.7+/-2.9) mm(3), 2.3+/-0.6, and 7.8mm(3), respectively in the IFN-alpha 3+/-10(5) U/day treated group(P<0.05); 0, 12.5%(1/8), 0.5mm(3), 2, 0.5 mm(3) in the IFN-alpha 6+/-10(5)U/day treated group(P<0.05); 0, 12.5%(1/8), 1 mm(3), 2.5+/-0.7, 8 mm(3) in the IFN-alpha 3+/-10(5) U/day and ATRA treated group(P<0.05); 87.5%, 100%, (1472.6+/-5.6) mm(3), 7.3+/-3.8, 768.5 mm(3) in the ATRA treated group (P>0.05). CONCLUSIONS: IFN-alpha has an inhibitory effect on intrahepatic recurrence and lung metastasis of human HCC after curative resection in nude mice, and the effect is enhanced with increasing dose. IFN-alpha and ATRA have no synergistic effect according to in vivo and in vitro test. ATRA has no effect on recurrence and metastasis of HCC.

Animals↗

PubMed2001

[Protective effects of organic acids on human vascular endothelial cells].

OBJECTIVES: In order to examine if organic acids (OA), a kind of natural food components, will prevent from atherosclerosis formation, the effects of four OA, namely chlorogenic acid (CHA), ascorbic acid (AA), citric acid (CA), and malic acid (MA) on human vascular endothelial cells were studied. METHODS: Primary human umbilical vein endothelial cells (EC) were cultured, and the changes of cell morphology, cell growth, lactate dehydrogenase (LDH) released from cells were measured when EC was incubated with oxidized low density lipoprotein (oxLDL) in the presence or not of four OA added at three different conditions, i.e. before 4 hours oxLDL added, at the same time as oxLDL added, and after 3 hours oxLDL added, as well as at the indicated doses (10, 20 or 40 mg/L). RESULTS: The EC survival rate of the oxLDL control group was lower (P < 0.01) and LDH release rate was higher (P < 0.01) than those of normal control group. CHA, AA, CA and MA protected EC from damage caused by oxLDL when they were added before and/or at the same time of oxLDL, but the same beneficial effects of these four OA added after oxLDL were not observed. The EC survival rates of CHA + oxLDL and AA + oxLDL groups in three doses were higher (P < 0.05) and the LDH release rates were lower (P < 0.05) in a dose-effect manner when compared with those of oxLDL control group, respectively. Similar results were found in the CA + oxLDL and MA + oxLDL of the high dose groups. CONCLUSION: Four tested OA could effectively prevent EC from damage induced by oxLDL. CHA and AA had the strongest effects, the next was CA, followed by MA.

Arteriosclerosis↗

PubMed2001

Dual effects of ouabain on the regulation of proliferation and apoptosis in human prostatic smooth muscle cells.

PURPOSE: To elucidate the role of ouabain in the pathophysiology of benign prostatic hyperplasia we examined the effects of ouabain on the proliferation and apoptosis of human prostatic smooth muscle cells. MATERIALS AND METHODS: Primary cultures of human prostatic smooth muscle cells were obtained from 7 patients with bladder outlet obstruction caused by benign prostatic enlargement. A cell proliferation study was performed using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay method to examine the effects of different concentrations of ouabain and various inhibitors. Western blot analysis was done to determine mitogen activated protein kinase (MAPK) activation. The terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick end-labeling reaction method and caspase-3 activity assay were also performed to examine the apoptotic mechanism. RESULTS: Ouabain exhibited a modest but significant proliferative effect in nanomolar concentrations; whereas it induced cell apoptosis at higher concentrations. Ouabain caused rapid activation of p42/44 MAPKs. The proliferative effect of ouabain was completely flattened by W-7 and MAPK kinase (MEK) inhibitor, suggesting the requirement of Ca(2+) mobilization and the involvement of the MEK-p42/44 MAPK cascade. The cytotoxic effect by ouabain was defined as apoptosis and necrosis using the terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick end-labeling reaction technique and lactate dehydrogenase release assay, respectively. In addition, ouabain induced profound caspase-3 activity in the cytotoxic concentrations and DEVD-CHO reversed the cytotoxic action to ouabain, demonstrating the involvement of caspase-3 activation in the cytotoxic action. CONCLUSIONS: Ouabain at different concentrations caused dual effects on proliferation and apoptosis in human prostatic smooth muscle cells. At low concentrations ouabain promoted cell proliferation via a Ca(2+) dependent mechanism and activation of the MEK-p42/44 MAPK pathway; whereas it induced cell apoptosis via the activation of caspase-3 activity at higher concentrations.

Analysis of Variance↗

PubMed2001

[3D visualization and information interaction in biomedical applications].

3D visualization and virtual reality are important trend in the development of modern science and technology, and as well in the studies on biomedical engineering. This paper presents a computer procedure developed for 3D visualization in biomedical applications. The biomedical models are constructed in slice sequences based on polygon cells and information interaction is realized on the basis of OpenGL selection mode in particular consideration of the specialties in this field such as irregularity in geometry and complexity in material etc. The software developed has functions of 3D model construction and visualization, real-time modeling transformation, information interaction and so on. It could serve as useful platform for 3D visualization in biomedical engineering research.

Biomedical Engineering↗

PubMed2001

Tissue factor--a receptor involved in the control of cellular properties, including angiogenesis.

Tissue factor (TF), the major initiator of blood coagulation, serves as a regulator of angiogenesis, tumor growth and metastasis. In several models, TF expression mediates upregulation of the proangiogenic vasular endothelial growth factor (VEGF) that can directly act on endothelial cells to promote vessel formation. This occurs through ligand binding, activation of signaling cascades, signal transduction and alteration of growth factor expression and is mediated by both, coagulation-dependent and -independent pathways. Depending on the cell type and the biological settings, TF seems to affect cellular properties through (i) factor VIIa (FVIIa)-dependent proteolysis of factor Xa (FXa) and thrombin and subsequent activation of proteinase activated receptor (PAR) -1 and PAR-2, (ii) through direct FVIIa signaling and mitogen activated protein (MAP) kinase activation, that is conferred by a not yet identified receptor, (iii) through interaction of FVII(a) proteolytic activity and signaling of the cytoplasmic domain and (iv) through cytoplasmic signaling independent of ligand binding. The role of phosphorylation of the cytoplasmic domain and the pathways controlling phosphorylation of TF remain poorly understood.

Animals↗

PubMed2001

[Characteristics of granular sludge during start-up of the internal circulation].

The quick start-up of the laboratory scale IC reactor and the characteristics of granular sludge during start-up were studied in this paper. The results showed that the first start-up of IC reactor could be finished in 20 days, while secondary start-up only needed 15 days with COD loading rate of 12-15 kg.(m3.d)-1 and COD removal larger than 85%. During start-up, the characteristics of granular sludge changed greatly: average granular diameter was increased from 0.88 mm to 1.25 mm; average settling velocity was enhanced from 35.4 m.h-1 to 105.17 m.h-1; methanogenic activities of the granular increased up to 4 times as large as the seeded sludge; the main methanobacteria was changed from Methanothrix to Methanococcus and Methanobacterium.

Sewage↗

PubMed2001

[Improvement of proliferation of intrasplenically transplanted fetal hepatocytes after immunoadsorption].

OBJECTIVE: To investigate whether removing the compartments of hemopoietic stem cells by immunoadsorption would improve the proliferation of fetal hepatocytes after transplantation. METHODS: The purification of fetal hepatocytes was performed by immunoadsorption, and the proliferative capability of fetal hepatocytes after intrasplenic transplantation was evaluated by image analysis and flowcytometry analysis. RESULTS: The yield of fetal hepatocytes after immnoadsorption was (2~3)+/-10(7) in total per fetal liver and the viability is over 85%. The square densities of fetal hepatocytes with image analysis at 3, 7, and 14 days after transplantation were (1603+/-337), (3788+/-605), (8129+/-1025) micrometer(2)/mm(2), and the adult hepatocytes were (1007+/-128), (2013+/-242), (3780+/- 772) mum(2)/mm(2) accordingly. The S phase rates of fetal hepatocytes by flowcytometry analysis were (14.25+/-4.11)%, (16.07+/-5.35)%, and (17.32+/-5.17)%, and the rates of adult hepatocytes were (5.66+/-1.02)%, (4.98+/- 0.74)%, and (6.83+/-1.37)% correspondingly. The S phase rates and the square densities of fetal hepatocytes were significantly higher than those of adult hepatocytes. CONCLUSIONS: Fetal hepatocytes are highly proliferative and potentially suitable as donor cells in hepatocytes transplantation after immunoadsorption.

Animals↗

PubMed2001

[Therapeutic potential of recombinant adenovirus expressing p53 in hepatocellular carcinoma cell lines].

OBJECTIVE: To investigate the effects of the recombinant adenoviral vector Ad-p53 on the biological behavior of hepatocellular carcinoma (HCC) cells in vitro and in vivo. METHODS: With recombinant adenoviral vector expressing WT-p53 (Ad-p53), p53 gene was transfected into the HCC cell line, PLC/PRF/5. The cytotoxicities of Ad-p53 to cells were measured by MTT assay. Cell growth properties and cell cycle patterns were assessed with flow cytometry. The animal model was developed by injecting HCC cells into the dorsum of nude mice. Ad-p53 was injected intratumorally. The animals were killed, and then excised tumors were weighed and analyzed for p53 and p21 protein expression using western blot assay. RESULTS: The introduction of exogenous wild-type p53 resulted in the inhibition of cell growth, high G2/M ratio and cell apoptosis, and low S ratio in PLC/PRF/5. The expression of both p53 and p21 proteins was upregulated in the cells. CONCLUSIONS: Replication-deficient adenoviral vector expressing WT-p53 may be useful for gene therapy of HCC.

Adenoviridae↗

PubMed2001

[Clinical and pathological study of autoimmune hepatopathy].

OBJECTIVE: To study the clinical and histologic characteristics of autoimmune hepatopathy, and to explore the diagnostic criteria and therapy. METHODS: Sixty-two patients with autoimmune hepatopathy were studied between 1996 and 1998 to compare primary biliary cirrhosis (PBC) and autoimmune hepatitis (AIH) in the clinical symptoms, signs, laboratory findings and histologic features. RESULTS: PBC was 59.68% and AIH 40.32% in the autoimmune hepatopathy. The morbidity in middle and old aged female patients with autoimmune hepatopathy was 83.8%. The ratio of male and female was 1:10. Whereas, the ratio of male and female was 1:5 in AIH patients and average age was 35 years old. Seropositive autoimmune antibodies were detected in 53 serum sample (PBC 85.29%; AIH 78.95%). Positive rates of the mitochondrial antibody and subtype-M2 were 100% for PBC. IgM increasing was 80% in PBC (P<0.05) and 82.35% in AIH (P<0.025). Histologic features in PBC group consisted of cholangitis, destruction or proliferation of the bile duct and inflammation within the portal tract; while in AIH group inflammation, necrosis and fibrosis of periportal region, the aggregation of lymphocytes, mononuclear cells and plasma cells in the portal tract or periportal area were found. CONCLUSIONS: PBC and AIH are the most common two types in the patients with autoimmune hepatopathy. AIH-I is more often seen clinically. AMA-M2 is the special autoimmune antibody of PBC. The efficacy of prednisolone is better for AIH than PBC.

Adult↗

PubMed2001

Sildenafil versus the vacuum erection device: patient preference.

PURPOSE: We evaluated the preference of patients with erectile dysfunction who had been effectively treated with a vacuum erection device and then switched to sildenafil. MATERIALS AND METHODS: A total of 52 patients with erectile dysfunction who achieved satisfactory erectile function according to the International Index of Erectile Function (IIEF) while using a vacuum erection device were switched to an increasing dose of sildenafil (range 25 to 100 mg.) until satisfactory erection was maintained at least twice a week for at least 1 month. The 2 treatment methods were not used concomitantly. A total of 36 patients with a mean age of 59 years (range 35 to 77) who claimed to have achieved satisfactory erections with a vacuum erection device and sildenafil reported their preference to continue sildenafil or resume the use of a vacuum erection device, reasons for the choice and any adverse side effects. RESULTS: Of the 36 participants in whom the efficacy of sildenafil was similar to that of a vacuum erection device according to the IIEF scores (mean plus or minus standard deviation 61.6 +/- 10.4 and 62.5 +/- 6, respectively), 12 (33.3%) decided to resume use of a vacuum erection device (group 1) while 24 (66.6%) preferred to continue sildenafil (group 2). There were no statistically significant differences between the groups regarding patient age or the etiology and duration of erectile dysfunction. The increase in the IIEF score while using a vacuum erection device was higher in group 1 than 2, with a mean of 66.75 versus 60.4, respectively (p = 0.002). The adverse side effects of sildenafil were the main reasons for preferring a vacuum erection device. Fewer ejaculatory difficulties, efficacy, comfort and ease of use were the main reasons for choosing sildenafil. CONCLUSIONS: Even in an era of effective oral medication, the vacuum erection device remains a preferred treatment option for a substantial number of patients with erectile dysfunction.

Adult↗

PubMed2001

[Screening and characterization of human phage antibody to hepatitis C core antigen].

OBJECTIVE: To screen and characterize human phage antibody (ScFv) against hepatitis C core antigen. METHODS: The recombinant phages were panned by core antigen that was coated in a microtiter plate. After three rounds of biopanning, 48 clones were determined specific to core antigen. The specificity of each ScFv colone was determined by ELISA. The coding gene for HCV protein ScFv has been sequenced. RESULTS: Phage antibody for HCV core protein had a specific combination character with core antigen of hepatitis C virus. The DNA sequence data showed that the ScFv gene included 774 bp. CONCLUSIONS: Human single chain antibody to hepatitis C core antigen has been identified by means of the phage display technology.

Amino Acid Sequence↗

PubMed2001

[Ectopic expression of human brain derived neurotrophic factor gene in fibroblasts].

The full-length sequence encoding hBDNF was inserted down into the enhancer-promotor regulatory element of Colia1 to construct minigene Colia1-BDNF. The recombinant eukaryotic expression plasmid pSCEPBFCAT was transfected into human fetal tendon fibroblasts in culture to realize ectopic expression of hBDNF gene in fibroblasts. The results of immuno-dot blot, Elisa and Western hybridization confirm that the expression protein with apparent molecular weight 27 kDa in pSCEPBFCAT transfected fibroblasts possesses antigen activity specific for the antibodies to BDNF.

Brain-Derived Neurotrophic Factor↗

PubMed2001

Comparison of ofloxacin and norfloxacin concentration in prostatic tissues in patients undergoing transurethral resection of the prostate.

BACKGROUND AND PURPOSE: To compare the concentrations of two fluoroquinolones, ofloxacin (OFLX) and norfloxacin (NFLX), in the prostate glands of patients who underwent transurethral resection of the prostate (TUR-P) after oral ingestion of both drugs for surgical prophylaxis. METHODS: Ten patients with clinical symptoms of benign prostatic hyperplasia undergoing TUR-P received 200 mg of both drugs per os simultaneously 2 hours before surgery. The concentrations of the drugs in the serum and prostate at the time of surgery were measured by high performance liquid chromatography. Patients' clinical characteristics were evaluated, including findings from transrectal ultrasonography of the prostate, prostate specific antigen concentration, renal function tests, and post-operative status. RESULTS: Two hours after administration, the mean serum concentration of OFLX was 4.14 +/- 0.64 mg/L (range 0.27-6.37) and of NFLX was 1.10 +/- 0.22 mg/L (range 0.02-2.1). The concentration of ORLX in prostatic tissue was 4.10 +/- 0.79 micrograms/g (range 1.70-6.37) and of NFLX was 2.22 +/- 0.57 micrograms/g (range 0.63-4.35). The ratio of the prostatic tissue concentration (P) to the serum concentration (S) was 2.11 for OFLX and 5.71 for NFLX. The concentrations of both drugs exceeded the minimum inhibitory concentration (MIC) for most gram-negative organisms, but NFLX may be unable to exceed the MIC90 of Enterobacter cloacae in some individuals. Leukocytosis and spiking fever developed after TUR-P in two of the 10 patients. CONCLUSIONS: Concentrations of OFLX were higher in both serum and prostatic adenoma tissues than those of NFLX (p < 0.001), while NFLX had better penetration into the prostate (P/S ratio) (p < 0.001). The results of this study indicated that the concentrations of both of these drugs exceeded the MIC for most gram-negative organisms.

Aged↗

PubMed2001

Differential inhibition and inactivation of human CYP1 enzymes by trans-resveratrol: evidence for mechanism-based inactivation of CYP1A2.

trans-Resveratrol (3,5,4'-trihydroxy-trans-stilbene) has been reported to confer chemoprotection against 7,12-dimethylbenz[a]anthracene (DMBA)-induced carcinogenicity in a murine model. A potential mechanism for this effect by trans-resveratrol is inhibition of DMBA-bioactivating cytochrome P450 (CYP) enzymes such as CYP1B1, CYP1A1, and CYP1A2. In the present study, we examined in detail the in vitro inhibitory effects of trans-resveratrol on these three human CYP enzymes. trans-Resveratrol decreased 7-ethoxyresorufin O-dealkylation activity catalyzed by human recombinant CYP1B1, CYP1A1, and CYP1A2 in a concentration-dependent manner and by a mixed type of inhibition. This direct inhibition was enzyme-selective, as judged by the differences in the apparent K(i) values (0.8 +/- 0.1 microM, 1.2 +/- 0.1 microM, and 15.5 +/- 1.1 microM for CYP1B1, CYP1A1, and CYP1A2, respectively). Preincubating recombinant CYP1A2 or human liver microsomes with trans-resveratrol and NADPH prior to the initiation of substrate oxidation resulted in a time- and concentration-dependent decrease in catalytic activity. The inactivation of liver microsomal CYP1A2 by trans-resveratrol required NADPH, was not reversible by dialysis, and was not affected by the trapping agents glutathione, N-acetylcysteine, catalase, or superoxide dismutase, but was attenuated by a CYP1A2 substrate, imipramine. Analysis of a panel of individual human liver microsomes showed intersample differences in the response to the in vitro inactivation by trans-resveratrol. In contrast to CYP1A2, CYP1B1 was not subject to inactivation by this compound and the reduction in CYP1A1 activity was time- but not concentration-dependent. In summary, trans-resveratrol differentially inhibited human CYP1 enzymes and this occurred by two distinct mechanisms: direct inhibition (mainly CYP1B1 and CYP1A1) and mechanism-based inactivation (CYP1A2).

Aryl Hydrocarbon Hydroxylases↗

PubMed2001

[A study of relationship between oral contraceptives and gene polymorphism and types of stroke].

OBJECTIVE: To evaluate the relationship between combined oral contraceptives (COC) taking and differential types of stroke, together with the role of the susceptive genetic factors associated with the onset of stroke in women using pills. METHODS: Case-case study was used. A total of 111 female patients with stroke were selected and with questionnaires filled in and blood samples collected. The distributions of coagulative factor V Leiden mutation (G1691-->A), prothrombin gene mutation (G20210-->A) and angiotensin converting enzyme (ACE) gene insertion/deletion(I/D) polymorphism were observed. Differences of genetic and nongenetic risk factors between hemorrhagic and ischaemic stroke were compared. RESULTS: Women using pills had a higher risk developing hemorrhagic than ischaemic stroke (OR = 3.03, P < 0.05), comparing with those never used pills. The strength of association between body mass index (BMI) > or = 24 kg/m2 and ischaemic stroke was much greater than it between BMI and hemorrhagic stroke (OR = 2.99, P < 0.05). No mutation of G1691-->A or G20210-->A was found. The deletion allele frequency of ACE gene was slightly higher in ischaemic stroke group, but with no statistic significance. CONCLUSION: The results suggested that possible association existed between the use of COC and the onset of hemorrhagic stroke, however the mutations of G1691-->A in factor V gene, G20210-->A in prothrombin gene and I/D polymorphism of ACE gene did not seem to contribute to this association.

China↗

PubMed2001

Pharmacokinetics of anastrozole in Chinese male volunteers.

AIM: To compare pharmacokinetics of domestic and imported tablets of anastrozole. METHODS: Twenty male Chinese volunteers were enrolled in a randomized crossover study with a single oral dose of 1 mg of the two formulations respectively. The anastrozole in plasma was measured by gas chromatography with electron-captured detector. Area under the drug concentration-time curve was evaluated by variance analysis and two one-side t-test. RESULTS: A two-compartment model was adopted in anastrozole plasma concentration-time data analysis. The paramaters such as Cmax, Tmax, T1/2beta, and AUC(0-infinity) were (10 +/- 3) and (10.2 +/- 2.5) microg/L, (1.2 +/- 0.5) and (1.3 +/- 0.4) h, (42 +/- 14) and (41 +/- 26) h, (443 +/- 141) and (429 +/- 121) microg . h . L-1, respectively, and there were no significant differences between the two formulations. CONCLUSION: Domestic and imported anastrozole were of bioequivalence. The relative bioavailability of the domestic tablet was 100 % +/- 9 %.

Adult↗

PubMed2001

Genetic modification of hematopoietic progenitor cells for combined resistance to 4-hydroperoxycyclophosphamide, vincristine, and daunorubicin.

AIM: To investigate whether human peripheral blood hematopoietic progenitor cells (PBPC) modified with human aldehyde dehydrogenase class-3 gene (ALDH-3) and multidrug resistance gene 1 (MDR1) would increase chemotherapy resistance to 4-hydroperoxycyclophosphamide (4-HC) and -glycoprotein effluxed drugs. METHODS: A bicistronic retroviral vector G1Na-ALDH3-IRES-MDR1 cDNA was constructed and used to transfect the packaging cell lines PA317 by electroporation. CD34+ PBPC were isolated with a high-gradient magnetic cell sorting system (MACS), and then were transfected with supernatant of retrovirus containing human ALDH-3 and MDR1 cDNA. PCR, RT-PCR, Southern blot, Northern blot, FACS, and MTT assay were used to evaluate the transfection and expression of the transgene in target cells. RESULTS: The bicistronic retroviral vector construction was verified by PCR and restriction endonuclease analysis. Dual drug resistance genes were integrated into the genomic DNA of CD34+ PBPC and expressed efficiently. The efficiency of gene transfection in CD34+ PBPC was tested to be 18 % on colonies. Nested PCR and Neor rescue assay indicated that no helper virus was present in this system. Compared with the untransduced cells, transgene recipient cells conferred 4.5-fold resistance to 4-HC, 6.6-fold and 7.8-fold resistance to P-glycoprotein effluxed drug, vincristine and daunorubicin, respectively. CONCLUSION: Efficient transduction of two different types of drug resistance genes into human peripheral blood hematopoietic progenitor cells and the co-expression may decrease cumulative myelosuppression of combination chemotherapy.

ATP Binding Cassette Transporter, Subfamily B, Mem↗