Biomedical subjects

Gao-feng Zhao

Publications and source records attributed to Gao-feng Zhao.

4 recordsLinked to original sources

PubMed2006

[Cloning of A73 gene and its coding sequence analysis].

OBJECTIVE: To clone A73 gene of Epstein-Barr virus (EBV) and examine the variation of its coding sequence. METHODS: A73 coding sequence (CDS) amplified from 7 patients in nasophryngeal carcinoma (NPC) biopsies by RT-PCR was cloned into pGEM-T-Easy vector to construct the recombinant plasmid, which was subjected to sequence analysis in Gen Bank database using Blast software. RESULTS: A73 gene from nasophryngeal carcinoma was successfully cloned into pGEM-T Easy vector. A locus with conversion of A-->C in A73 was found at CDS 45 nt, located in the exonVB157154 nt, which did not result in an amino acid replacement, and the variation frequency was 7/7. CONCLUSION: There is a point mutation in A73 CDS of EBV isolated from NPC tissue, which might produce NPC-associated polymorphism with possible involvement in the composition of some subtype of EB virus.

Cloning, Molecular↗

PubMed2005

Effects of oxidized low density lipoprotein on the growth of human artery smooth muscle cells.

BACKGROUND: Studies have shown that oxidized low density lipoprotein (ox-LDL) promotes the pathogenesis and development of atherosclerosis (AS), and that the proliferation, migration and phenotype alteration of vascular smooth muscle cells (vSMCs) into foam cells are critical changes in AS. It is proposed that ox-LDL might play a novel role in the pathologic process of vSMCs. The present study was performed ex vivo to investigate the effects of ox-LDL on the growth of cultured human vSMCs. METHODS: Using NaBr density gradient centrifugation, LDL from human plasma was isolated and purified. ox-LDL was produced from LDL after being incubated with CuSO4. ox-LDL was then added to the culture medium at different concentrations (25 microg/ml, 50 microg/ml, 75 microg/ml, 100 microg/ml, 125 microg/ml, and 150 microg/ml) for 7 days. The influence of ox-LDL on vSMC growth was observed from several aspects as growth curve, mitosis index, lipid staining, and in situ determination of apoptosis. The digital results were analyzed with SPSS 10.0. RESULTS: The ox-LDL produced ex vivo had a good purity and optimal oxidative degree, which was similar to the intrinsic ox-LDL in atherosclerotic plaque. ox-LDL at a concentration of 25 microg/ml demonstrated the strongest proliferation. At the concentration of 125 microg/ml, ox-LDL suppressed the growth of vSMCs. At concentrations of 25 microg/ml and 50 microg/ml, ox-LDL presented powerful mitotic trigger. When the concentration of ox-LDL increased, the mitotic index of vSMCs decreased gradually. ox-LDL induced more foam cells from vSMCs with rich intracellular lipid accumulation at concentrations of 25 microg/ml and 50 microg/ml. ox-LDL at higher concentrations induced more apoptotic vSMCs. CONCLUSIONS: ox-LDL at lower concentrations may trigger proliferation and phenotype alteration into foam cells of vSMCs, and at higher concentrations it may induce apoptosis in vSMCs. ox-LDL plays an important role in the pathogenesis and development of atherosclerosis by its effect on vSMCs proliferation, phenotype alteration and apoptosis.

Apoptosis↗

PubMed2003

[Molecular basis of preventive effect of human apolipoprotein-1 on murine vascular smooth muscle cell proliferation and lipid deposition induced by oxidized low density lipoprotein].

OBJECTIVE: To study the molecular basis of preventive effect of human apolipoprotein-1 (h-apoA-1) on vascular smooth muscle cell (vSMC) proliferation and lipid deposition induced by oxidized low density lipoprotein (ox-LDL). METHODS: Smooth muscle cells originated from the aortae of h-apo-A-1 transgenic mice were cultured and divided into 2 groups, one group was stimulated by ox-LDL (tester) and the other group was used as control (driver). Subtractive hybridization was used to enrich the genes differentially expressed in the vSMCs induced by ox-LDL. A subtractive library was thus established and confirmed by colony hybridization in situ and dot blot analysis. 15 clones out of the 57 differentially expressed clones were randomly chosen foe sequencing and homology analysis. The whole-length cDNA library of vSMC induced by ox-LDL was established using SMART technique. RESULTS: Three expression sequence tags (EST), all correlated with immune system, were confirmed: C1-inhibitor (C1-INH), lectin, and T cell receptor beta. The whole-length cDNA library contained 1.5 x 10(6) pfu/ml primary recombinants with insertions 0.5 - 3 kb in length. CONCLUSION: The 3 EST may be involved in the mechanism of atherogenesis by ox-LDL and the mechanism of the function of h-ApoA-1 in retarding the progression of atherogenesis induced by ox-LDL.

Animals↗

PubMed2003

[Comparative study of right anterolateral minithoracotomy and median sternotomy in the repair of atrial septal defects].

OBJECTIVE: To compare the effect of right anterolateral minithoractomy and median sternotomy for atrial septal defect closure. METHODS: In this study, 82 patients, whose age ranged from 4 to 46 years with a mean of 15.7+/-8.6 years, underwent surgical repair of the atrial septal defects on the beating heart through right anterolateral minithoractomy. Ten of these cases were complicated by moderate to severe pulmonary hypertension, and 3 by partial anomalous pulmonary venous connection. Another 67 patients with an age range of 3 to 49 years (mean 17.0+/-12.5 years) underwent surgical repair of the atrial septal defects through full-length median sternotomy with the heart beat arrested, and complication of moderate to severe pulmonary hypertension was identified in 11 cases and partial anomalous venous connection in 5. Comparisons were performed between the 2 groups in terms of the length of skin incision, cardiopulmonary bypass (CPB) time, postoperative mechanical ventilation time, intensive care unit stay, postoperative hospital stay, and the volume of postoperative drainage. RESULTS: There was no operative mortality in either of the 2 groups. In the former group, the CPB time (35.2+/-14.1 min), postoperative mechanical ventilation time (6.5+/-2.5 h), postoperative drainage volume (237.6+/-172.5 ml), postoperative hospital stay (7.4+/-1.2 d) and skin incision length (6.5+/-0.9 cm) were all significantly less than those of the latter group of patients, whose CPB time was 42.7+/-11.8 min, postoperative mechanical ventilation time 7.9+/-3.8 h, postoperative drainage volume 304.3+/-192.4 ml, postoperative hospital stay 9.0+/-2.9 d and skin incision length 15.9+/-1.7 cm (P < 0.01). The intensive care unit stay did not differ significantly between the 2 groups (35.1+/-16.2 h vs 32.3+/-24.1 h, P > 0.05). CONCLUSION: A right anterolateral minithoracotomy for repairs of atrial septal defects is a safe, effective and simple technique to ensure minimal surgical invasion with shorter postoperative hospital stay. Minithoracotomy can be performed to replace median sternotomy in the correction of atrial septal defects, including those complicated by partial anomalous pulmonary venous connection.

Adolescent↗