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Biomedical subjects

Jun Liu

Publications and source records attributed to Jun Liu.

At least 307 records · Page 17Linked to original sources
PubMed2003

Spectroscopic and electrochemical studies of DNA breakage induced by dopamine and copper ion.

Dopamine may show some biological activities in antitumor and cell apoptosis. Herein, we attempted to employ UV-Vis, CD, and electrochemical methods to investigate the interaction between DNA and dopamine. Both the spectroscopic and electrochemical evidence indicated that dopamine, which was a cation, could interact with polyanion DNA. However, this kind of interaction, mainly by a static electronic force, did not result in any damage of the DNA structure. This situation was quite different when Cu ion was added to the dopamine-DNA system; an obvious change in the color of the solution and in the spectra of UV-Vis and CD showed that some chemical changes occurred in this system, and that the DNA native structure was destroyed. The results of gel electrophores further revealed that DNA might be broken into small segments by dopamine in the presence of Cu ion. The possible reaction mechanisms are discussed.

Circular Dichroism↗
PubMed2003

Polymorphisms in the insulin-degrading enzyme gene are associated with type 2 diabetes in men from the NHLBI Framingham Heart Study.

Linkage studies have mapped a susceptibility gene for type 2 diabetes to the long arm of chromosome 10, where we have previously identified a quantitative trait locus that affects fasting blood glucose within the Framingham Heart Study cohort. One candidate gene in this region is the insulin-degrading enzyme (IDE), which, in the GK rat model, has been associated with nonobese type 2 diabetes. Single nucleotide polymorphisms (SNPs) were used to map a haplotype block in the 3' end of IDE, which revealed association with HbA(1c), fasting plasma glucose (FPG), and mean fasting plasma glucose (mFPG) measured over 20 years. The strongest associations were found in a sample of unrelated men. The lowest trait values were associated with a haplotype (TT, f approximately 0.32) containing the minor allele of rs2209772 and the major allele of the rs1887922 SNP (FPG P < 0.001, mFPG P < 0.003, HbA(1c) P < 0.025). Another haplotype (CC, f approximately 0.16) was associated with elevated HbA(1c) (P < 0.002) and type 2 diabetes (P < 0.001, odds ratio 1.96, 95% CI 1.28-3.00). The evidence presented supports the possibility that IDE is a susceptibility gene for diabetes in populations of European descent.

Blood Glucose↗
PubMed2003

Association between HLA class II gene and susceptibility or resistance to chronic hepatitis B.

AIM: To investigate the association between the polymorphism of HLA-DRB1, -DQA1 and -DQB1 alleles and viral hepatitis B. METHODS: HLA-DRB1, -DQA1 and -DQB1 alleles in 54 patients with chronic hepatitis B, 30 patients with acute hepatitis B and 106 normal control subjects were analyzed by using the polymerase chain reaction/sequence specific primer (PCR/SSP) technique. RESULTS: The allele frequency of HLA-DRB1*0301 in the chronic hepatitis B group was markedly higher than that in the normal control group (17.31% vs 5.67%), there was a significant correlation between them (chi2=12.3068, Pc=0.0074, RR=4.15). The allele frequency of HLA-DQA1*0501 in the chronic hepatitis B group was significantly higher than that in the normal control group (25.96% vs 13.68%), there was a significant correlation between them (chi2=9.2002, Pc=0.0157, RR=2.87). The allele frequency of HLA-DQB1*0301 in the chronic hepatitis B group was notably higher than that in the normal control group (35.58% vs 18.87%), there was a significant correlation between them (chi2=15.5938, Pc=0.0075, RR=4.07). The allele frequency of HLA-DRB1*1101/1104 in the chronic hepatitis B group was obviously lower than that in the normal control group (0.96% vs 13.33%), there was a significant correlation between them (chi2=11.9206, Pc=0.0145, RR=18.55). The allele frequency of HLA-DQA1*0301 in the chronic hepatitis B group was remarkably lower than that in the normal control group (14.42% vs 30%), there was a significant correlation between them (chi2=8.7396, Pc=0.0167, RR=0.35). CONCLUSION: HLA-DRB1*0301, HLA-DQA1*0501 and HLA-DQB1*0301 are closely related with susceptibility to chronic hepatitis B, and HLA-DRB1*1101/1104 and HLA-DQA1*0301 are closely related with resistance to chronic hepatitis B. These findings suggest that host HLA class II gene is an important factor determining the outcome of HBV infection.

Acute Disease↗
PubMed2003

Targeted ribonuclease can inhibit replication of hepatitis B virus.

AIM: To study the effect of a novel targeted ribonuclease (TN), the fusion protein of HBVc and human eosinophil-derived neurotoxin (hEDN), on the HBV replication in vitro. METHODS: The gene encoding the targeted ribonuclease was cloned into pcDNA3.1 (-) to form recombinant eukaryotic expression vector p/TN. Control plasmids, including p/hEDN, p/HBVc, and p/TNmut in which a Lys113-Arg mutation was introduced by sequential PCR to eliminate the ribonuclease activity of hEDN, were also constructed. Liposome-mediated transfection of 2.2.15 cells by p/TN, p/TNmut, p/hEDN, p/HBVc, and pcDNA3.1 (-), or mock transfection was performed. After that, RT-PCR was used to verify the transgene expression. Morphology of the transfected cells was observed and MTT assay was performed to detect the cytotoxicity of transgene expression. Concentration of HBsAg in the supernatant of the transfected cells was measured using solid-phase radioimmunoassay. RESULTS: Transgenes were successfully expressed in 2.2.15 cells. No obvious cytotoxic effect of transgene expression on 2.2.15 cells was found. The HBsAg concentration in the p/TN transfected cells was reduced by 58 % compared with that of mock transfected cells. No such an effect was found in all other controls. CONCLUSION: The targeted ribonuclease can inhibit HBV replication in vitro while it has no cytotoxicity on host cells. The targeted ribonuclease may be used as a novel antiviral agent for human HBV infection.

Eosinophil-Derived Neurotoxin↗
PubMed2003

Inhibition of HBV targeted ribonuclease enhanced by introduction of linker.

AIM: To construct human eosinophil-derived neurotoxin(hEDN) and HBV core protein (HBVc) eukaryotic fusion expression vector with a linker (Gly(4)Ser) (3) between them to optimize the molecule folding, which will be used to inhibit HBV replication in vitro. METHODS: Previously constructed pcDNA3.1(-)/TR was used as a template. Linker sequence was synthesized and annealed to form dslinker, and cloned into pcDNA3.1(-)/TR to produce plasmid pcDNA3.1(-)/HBc-linker. Then the hEDN fragment was PCR amplified and inserted into pcDNA3.1(-)/HBc-linker to form pcDNA3.1(-)/TNL in which the effector molecule and the target molecule were separated by a linker sequence. pcDNA3.1(-)/TNL expression was identified by indirect immunofluorescence staining. Radioimmunoassay was used to analyse anti-HBV activity of pcDNA3.1(-)/TNL. Meanwhile, metabolism of cells was evaluated by MTT colorimetry. RESULTS: hEDN and HBVc eukaryotic fusion expression vector with a linker (Gly(4)Ser)(3) between them was successfully constructed. pcDNA3.1(-)/TNL was expressed in HepG2.2.15 cells efficiently. A significant decrease of HBsAg concentration from pcDNA3.1(-)/TNL transfectant was observed compared to pcDNA3.1(-)/TR (P=0.036, P<0.05). MTT assay suggested that there were no significant differences between groups (P=0.08, P>0.05). CONCLUSION: Linker introduction enhances the inhibitory effect of HBV targeted ribonuclease significantly.

Carcinoma, Hepatocellular↗
PubMed2003

Anti-HBV effect of TAT- HBV targeted ribonuclease.

AIM: To prepare and purify TAT-HBV targeted ribonuclease fusion protein, evaluate its transduction activity and investigate its effect on HBV replication in 2.2.15 cells. METHODS: The prokaryotic expression vector pTAT containing TR gene was used in transforming E.coli BL21 (DE3) LysS and TR was expressed with the induction of IPTG. The TAT-TR fusion protein was purified using Ni-NTA-agrose and PD-10 desalting columns, and analyzed by SDS-PAGE. Transduction efficiency of TAT-TR was detected with immunofluorescence assay and the concentration of HBeAg in the supernatant of the 2.2.15 cells was determined via solid-phase radioimmunoassay (spRIA). MTT assay was used to detect the cytotoxicity of TAT-TR. RESULTS: The SDS-PAGE showed that the TAT-TR fusion protein was purified successfully, and the purity of TAT-TR was 90 %. The visualization of TAT-TR by immunofluorescence assay indicated its high efficiency in transducing 2.2.15 cells. RIA result suggests that TAT-TR could inhibit the replication of HBV effectively, it didn't affect cell growth and had no cytotoxicity. CONCLUSION: TAT-TR possesses a significant anti-HBV activity and the preparation of TAT-TR fusion protein has laid the foundation for the use of TR in the therapeutic trial of HBV infection.

Cells, Cultured↗
PubMed2003

[The trends of body mass index and overweight in population aged 25 - 64 in Beijing during 1984 - 1999].

OBJECTIVE: To analyse the trends of body mass index (BMI) and overweight in a population aged 25 through 64 years in Beijing. METHOD: During 1984 to 1999, five cross-sectional surveys on cardiovascular disease (CVD) risk factors were carried out in the CVD monitoring population in Beijing. The mean levels and trends of BMI as well overweight in different sexs, age groups and areas were analysed. RESULTS: (1) In the period of 1984 to 1999, the mean BMI increased from 23.3 to 24.0 (kg/m(2)) in population aged 25 to 64 years, and overweight increased from 27.5% to 35.9%. (2) From 1984 to 1999, the prevalence of overweight increased from 23.5% to 43.3% in males. This increasing trend was seen in both urban and rural populations and in all age groups. Prevalence of overweight decreased from 36.0% to 23.3% in urban females, but increased from 28.4% to 46.0% in rural females. (3) From 1984 to 1999, prevalence of overweight increased from 29.1% to 31.8% in urban population, while 22.1% to 49.6% in rural population. BMI and prevalence of overweight were higher in urban than in rural (P < 0.05) in 1984 to 1985 but the levels in rural were approaching and exceeding the levels in urban (P < 0.05) in 1999. CONCLUSION: Trends of BMI and overweight increased in the urban males and both males and females in the rural, while the increase of both BMI and overweight was seen more rapid in rural than in urban.

Adult↗
PubMed2003

[Study on the distribution and association of cholesteryl ester transfer protein-TaqIB polymorphism and plasma concentration in general population].

OBJECTIVE: To study the distribution of cholesteryl ester transfer protein (CETP)-TaqIB polymorphism and plasma concentration in general population and the association between the two. METHODS: A cross-sectional study was carried out in a general population of Beijing in 1999, using stratified-random sampling method. CETP-TaqIB polymorphism and plasma CETP concentration were determined in 719 individual aged 45 - 64 years. RESULTS: (1) Frequencies of B1B1, B1B2 and B2B2 genotypes were 0.356, 0.478 and 0.166, respectively. The frequency of allele B2 was 0.405. Distributions of genotypes and alleles were homogeneous in both sexes. (2) Plasma CETP concentration manifested as a normal distribution, with the mean of 2.03 micro g/ml. The value of female was 20.3%, higher than that of male (P < 0.001). There were no differences among age groups. (3) Plasma CETP concentrations of B1B1 and B1B2 were 19.6% and 13.4% higher than that of B2B2 homozygotes. (4) Stratified by lipid levels, smoking and alcohol consumption, only when tryglyceride exceeded 150 mg/dl, with no significant difference among three genotypes. The effect of lipids, smoking and alcohol consumption status was more significant in B1B2 heterozygotes. CONCLUSION: CETP-TaqIB polymorphism was a determinant of plasma CETP concentration. However, the effect could be modified by other factors, such as lipids, smoking and alcohol consumption.

Carrier Proteins↗
PubMed2003

[Preparation of hollow fiber bioreactor for culturing pig hepatocytes].

OBJECTIVE: To study the method of preparing the hollow fiber bioreactor for culturing pig hepatocytes. METHODS: Hepatocytes were isolated from experimental suckling minipigs by two-step perfusion with collagenase, and seeded onto hollow fiber bioreactor, then cultured with an artificial capillary cell culture system. The albumin-excretion, lidocaine-transforming rate, lactate dehydrogenase (LDH) release and the cell viability in bioreactors were examined. RESULTS: The porcine albumin could be detected by SDS/PAGE on the 2nd, 4th, 6th day. The rates of lidocaine-transforming ranged from 89.6% to 96.1%. The release of LDH into the culture medium increased from (23.7+/-4.6) U/L to (127.8+/-17.4) U/L (F=39.582, P<0.01) during the experiments, and the viability of pig hepatocytes in hollow fiber bioreactor reduced from 95.8%+/-0.3% to 83.8%+/-4.7% (t=5.135, P<0.01). CONCLUSION: The hollow fiber bioreactor for culturing pig hepatocytes can be prepared by artificial capillary cell culture system, which provides a certain liver-specific function in 1 week.

Animals↗
PubMed2003

[Clinical application and animal experiment of thoracic tracheal reconstruction by using pulmonary tissue flap].

OBJECTIVE: To study the usability of pulmonary tissue flap in the reconstruction of the thoracic trachea. METHODS: Over half perimeter anterior and posterior wall and 6 to 8 tracheal cartilagious rings of dog trachea were resected. The nickel-titanium alloy mesh stent was placed inside the lumen for repair of the defect of the tracheal wall by nearby pulmonary tissue flap with the vascularized segment. The dogs were killed from 2 months to 12 months after operation. Specimens were taken and observed under light and electron microscope. Clinically, 4 patients were treated by this way operation [right common tracheal scarred stenosis and atresia (1), mixed cancerization in the lower part of the common trachea (1) and left common tracheal carcinoid (2)]. RESULTS: No stenosis and granulation tissue were observed in the prosthetic lumen, in which there was comparative continuous stratified ciliated columnar epithelium. All patients recovered respiratory function. CONCLUSION: Pulmonary tissue flap is a promising prosthesis of thoracic tracheal reconstruction.

Animals↗
PubMed2003

[Lung squamous cell carcinoma-related genes cloned by using suppression subtractive hybridization].

OBJECTIVE: To identify genes differentially expressed in human lung squamous cell carcinoma (LSCC). METHODS: A subtracted cDNA library of human LSCC constructed by using suppression subtracted hybridization (SSH) method was screened. Clones representing mRNAs that were truly differentially expressed in LSCC but not in its adjacent non-cancerous tissues were identified by semi-quantitative RT-PCR in 12 patients with LSCC. Partial novel genes were detected by Northern blot. RESULTS: Ten differentially expressed gene cDNA fragments of LSSC were obtained by SSH. Among them six were known genes; two sequences were identified but their functions were unknown (hypothetical protein); two were novel (GenBank accession numbers AF363068 and AY032661, respectively). The results from semiquantitative RT-PCR showed that the transcription expression level of PPP1CB, calumenin, S100A2, HSNOV1, OCIA and AY032661 was down-regulated in some LSCC cases, while the transcription of HSP90, ferritin, gp96 and AF363068 was up-regulated in others. CONCLUSIONS: Six known genes identified by SSH technique have been implicated in the pathogenesis of lung carcinogenesis, or they are involved in immunological defense mechanism in human body. Two hypothetical proteins probably also play an important role in the pathogenesis of lung cancer. The function of the two novel genes in lung carcinogenesis are under investigation.

Carcinoma, Squamous Cell↗
PubMed2003

[Ectopic osteogenesis of tissue engineered bone with slow-released bioactive factors].

OBJECTIVE: To study the ectopic osteogenesis of tissue engineered bone with recombinant human bone morphogenetic protein/transforming growth factor-beta (rhBMP/TGF-beta) or WO-1 slow-released factors. METHODS: Partial demineralized freeze-dried bone (PDFDB) of pig was used as scaffold material. rhBMP/TGF-beta or WO-1 were pre-coated on the surface of material by means of vacuum negative pressure absorption, and then coated with polylactic acid (PLA) to make slow-released material. There were six group: PDFDB material (group A); PDFDB combined with osteoblasts (group B); PDFDB material with rhBMP/TGF-beta slow-released system (group C); PDFDB material combined with rhBMP/TGF-beta slow-released system osteoblasts (group D); PDFDB with WO-1 slow-released system (group E); PDFDB material combined with WO-1 slow-released system and osteoblasts (group F) were implanted in bilateral lower limbs of 36 Newzealand rabbits respectively (6 rabbits in each groups). Histological, histochemical and biochemical analysis were detected 2, 4, 6, 8 weeks after operation. RESULTS: Within the observation periods, no osteogenesis was observed in group A. The osteogenesis in group B, D, F were superior to that of group C and E (P < 0.05). The osteogenetic activity in group C and E was delayed. The quantity and quality of osteogenesis in group D and F were 2 weeks ahead of time compared with group B, and 4 weeks to that of group C and E. The newborn calcification content was superior to that of group A, C, and E (P < 0.05). CONCLUSIONS: The osteogenesis of PDFDB materials with BMP/TGF-beta or WO-1 is slower than that of which combined with osteoblasts. Simple material PDFDB has no ectopic osteogenesis.

Animals↗
PubMed2003

[Inflammatory status in patients with end-stage renal disease: role of monocyte activation].

OBJECTIVE: To study the association of monocyte activation and the inflammatory status in patients with end-stage renal disease (ESRD). METHODS: A total of 166 ESRD patients were recruited in the study, including 63 patients with pre-dialysis chronic renal failure (CRF), 16 undergoing continuous ambulatory peritoneal dialysis (CAPD) and 87 stable hemodialysis (HD) patients. Monocyte activation markers including plasma neopterin, tumor necrosis factor (TNF)-alpha, interleukin (IL)-1beta, and plasma levels of acute phase proteins (APP) such as C-reactive protein (CRP) and serum amyloid A (SAA) were monitored using enzyme-linked immunosorbent assay (ELISA) kits. RESULTS: The levels of neopterin, TNF-alpha, IL-1beta, CRP and SAA significantly increased in ESRD patients as compared with the normal controls (P<0.05 ). CRP and SAA in HD patients were higher than those in non-dialysis patients (P<0.05). The levels of CRP was closely correlated with neopterin, TNF-alpha and IL-1beta(r=0.287, 0.314, 0.262, P<0.05, respectively), and SAA with neopterin (r=0.306, P<0.05). These correlations remained significant after the values were adjusted for creatinine clearance in non-dialysis patients. Plasma contents of TNF-alpha, IL-1beta, CRP and SAA were significantly elevated after a single hemodialysis session (P<0.05). CONCLUSION: Chronic inflammation occurs in patients with ESRD, which might be aggravated by hemodialysis. Activation of the monocytes might be involved in the pathogenesis of inflammation in uremia.

Acute-Phase Proteins↗
PubMed2003

[Preliminary evaluation on the effects of a hybrid bioartificial liver support system in the treatment of hepatic failure].

OBJECTIVES: To construct a novel hybrid artificial liver support system and evaluate its clinical efficacy in the treatment of hepatic failure. METHODS: A hybrid bioartificial liver support system consisting of plasma exchange device, charcoal perfusion column, and bioreactor cultured human or porcine hepatocytes was developed. 30 patients with hepatic failure were treated using this hybrid system. RESULTS: Both the excellent rate and effectual rate of the artificial liver support system were 43.3% (13/30). The total effectual rate was 86.7%. Finally, eleven out of 30 patients recovered completely. Six patients were bridged to liver transplantation. Six patients (20%) died of hepatic failure and seven patients (23.3%) discharged due to worsening of disease. CONCLUSIONS: The hybrid artificial liver support system has prominent liver support effects for hepatic failure, which can be regarded as an efficient measure for the treatment of severe hepatitis.

Adult↗
PubMed2003

[The role of releasing the fibrous bundles across levator muscle in correcting congenital blepharoptosis].

OBJECTIVE: To investigate the role of releasing the fibrous bundles across the levator muscle between the medial canthus and lateral canthsus near the top of tarsus in the correction of the congenital blepharoptosis. METHODS: Twenty-seven patients with 40 eyes of blepharoptosis were undergoing the treatment. It was performed by releasing the fibrous bundles across the levator muscle between the medial canthus and lateral canthsus near the top of tarsus to correct the mild and moderate blepharoptosis. A further procedure can also be added to by folding the levator aponeurosis if necessary. In the severe blepharoptosis, the frontalis aponeurose flap may be applied for the suspension as well during the operation. RESULTS: Of the 40 eyes in 27 cases with mild, moderate and severe blepharoptosis were treated by using this method, with 38 eyes corrected satisfactorily and 2 eyes corrected mostly in the following-ups from 3 months to 1 year. CONCLUSION: The above mentioned technique may be a good, simple and effect method to corret congenital blepharoptosis.

Adolescent↗
PubMed2003

[A study on the incidence of cardiovascular disease on the metabolic syndrome in 11 provinces in China].

OBJECTIVE: To explore the association of metabolic syndrome with CVD in a cohort study involving 11 provinces. METHODS: A cohort study was carried out in a population of 27 739 subjects (age 35 - 64 years). A baseline survey on the risk factor of cardiovascular disease was done in 1992. Incidence rate and relative risk were calculated for metabolic syndromes. RESULTS: (1) The age-standardized incidence rate of cardiovascular disease for metabolic syndromes (MS) was higher than those without (MS) in this cohort (MS 652.3/100,000, not MS 206.7/100,000, RR = 3.12, P < 0.001). (2) The incidence rate of cardiovascular disease for patients with hypertension but low HDL cholesterol and high waist was the highest (910.2/100,000 in man, 930.7/100,000 in woman) among all metabolic syndromes patients. (3) The predictive risk factors for cardiovascular disease were age, cigarette smoking, BMI, total cholesterol and metabolic syndrome in men, with age, BMI and metabolic syndrome in women. CONCLUSION: The incidence rate of cardiovascular disease on the metabolic syndrome was high in 11 provinces in China. Age, BMI and metabolic syndrome were the predictive risk factors of cardiovascular disease (especially of cerebrovascular disease). It is essential to prevent risk factors of cardiovascular disease in primary and secondary prevention programs in general population.

Adult↗
PubMed2003

[Removal of phthalate esters from drinking water using ozone-GAC process].

This study investigated the feasibility of using ozone-GAC process to remove phthalate esters from drinking water through a batch-scale study and adsorption isotherms. Dimethyl phthalate (DMP), diethyl phthalate (DEP) and dibutyl phthalate (DBP) were selected as the representative of phthalate esters. Results indicated that ozonation remove more than 40% DMP, DEP and DBP, GAC absorbed all the DMP, DEP and DBP that had not been oxidized by ozone at the condition of the Empty Bed Contact Time (EBCT) from 4 minutes to 12 minutes. The isotherms for GAC were successful correlated by Freundlich equation, and the date was used to estimate GAC service time. The results indicated that ozone-GAC process is a feasible way to remove DMP, DEP and DBP from drinking water.

Charcoal↗