2.Effect of antisense epidermal growth factor receptor cDNA transfection on telomerase activity of glioblastomas cells
Xinxia TIAN ; Yungang ZHANG ; Juan DU ; Jie ZHENG
Journal of Peking University(Health Sciences) 2004;0(03):-
Objective: To study the effects of antisense epidermal growth factor receptor (EGFR) cDNA transfection on telomerase activity and telomere length of glioblastomas U87MG cells and the mechanism. Methods: Glioblastoma U87MG cells, which over-expressed EGFR, were transfected with antisense-EGFR cDNA constructs. Several clones stably expressing lower or undetectable levels of EGFR protein were obtained. The effect of antisense-EGFR cDNA on telomerase activity was assessed by Telomeric Repeat Amplification Protocol (TRAP) assay. The effect of antisense- EGFR cDNA on telomere length was determined by Southern blot hybridization. The mRNA expressions of hTERT, hTEP1 and c-myc were analyzed by semi-quantitative PCR. Results: U87MG cells that were transfected with antisense-EGFR cDNA expressed lower level of EGFR and were less responsive to the growth stimulation of EGF compared with the control cells. Telomerase activity was significantly decreased in the antisense-EGFR clones. Telomere length was shortened. The mRNA expression of hTERT was slightly decreased in the antisense-EGFR clones, whereas the expressions of hTEP1 and c-myc were not altered. Conclusion: Antisense-EGFR cDNA transfection can sufficiently inhibit EGFR signal transduction pathway, decrease telomerase activity and shorten telomere length, which may be a new mechanism of antisense-EGFR approach in tumor suppression. The down-regulation of hTERT mRNA may contribute to the decreased telomerase activity in the antisense-EGFR clones.
3.Study of Key Electrochemical Problems in Transdermal Noninvasive Glucose Monitoring
Qingde YANG ; Hongmin LIU ; Chunxiu LIU ; Yinzeng HE ; Qing TIAN ; Xinxia CAI
Chinese Journal of Analytical Chemistry 2009;37(11):1566-1571
Several key problems were analysed for the transdermal noninvasive glucose monitoring. A modified calibration equation was proposed for the high-sensitivity glucose biosensor due to its narrow linear range. The new equation has increased the sensors' linear range by 20 times. A new diffuse model was constructed for the electrode system of glucose sensor,aiming at the unique "finite space" electrochemical problem in trans-dermal technique. In addition,electrode masks were utilized to solve the problem of electrode loss in longtime glucose monitoring. In animal in-vivo experiments,70.1 % of the noninvasive glucose data points were clinically accurate,while the remains were clinically acceptable. All solutions mentioned above were based on both theoretical analysis and experimental validation,promoting the realization and optimization of transdermal noninvasive glucose monitoring techniques.
4.The outcome of 256 cases of endoscopic sinus surgery.
Journal of Clinical Otorhinolaryngology Head and Neck Surgery 2010;24(20):934-936
OBJECTIVE:
To evaluate the curative effect of endoscopic sinus surgery (ESS).
METHOD:
Two hundred and fifty-six cases with chronic sinusitis and nasal polyps, undergone ESS from 2001 to 2007 were analysed. There were 106 cases in type 1, 134 cases in type 2 and 16 cases in type 3. Two hundred and forty-six cases undergone ESS with intranasal local anesthesia and potentialized anesthesia. Long-time follow-up was performed at 9 to 42 months (mean = 15 months).
RESULT:
The results showed that cure rate was 78.3% for type 1, 66.4% for type 2 and 43.8% for type 3. There was significant difference in cure rate between type 1, type 2 and type 3 (P < 0.01). Complication of ESS of 256 cases was 4.3%.
CONCLUSION
There was higher efficacy and safety for relief of nasal polyps and for relief of chronic sinusitis with ESS. The difference of clinical type in nasal polyps and chronic sinusitis affected directly surgical result.
Adolescent
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Adult
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Aged
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Chronic Disease
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Endoscopy
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methods
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Female
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Humans
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Male
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Middle Aged
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Nasal Polyps
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surgery
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Sinusitis
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surgery
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Treatment Outcome
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Young Adult
5.The effects of wild-type PTEN transfection on gene expressions of glioblastomas.
Xinxia TIAN ; Jinfen WANG ; Jinxia ZHANG ; Juan DU ; Chung Sean PANG ; N G HO-KEUNG
Chinese Journal of Pathology 2002;31(1):46-49
OBJECTIVETo study the effects of wild-type PTEN on gene expressions of glioblastomas.
METHODSGlioblastoma U87MG cells, which express inactivated PTEN, were transfected with wild-type PTEN constructs and stable transfected clones were selected. Then, cDNA microarray analyses were used to identify differentially expressed genes in wild-type PTEN transfected cells and control cells.
RESULTSTransfected wild-type PTEN inhibited the proliferation of U87MG. By cDNA microarray analyses, 89 cDNA clones were identified, which were differentially expressed in wild-type PTEN transfected cells and control cells. Among these genes, 13 genes were unknown and 76 genes were known genes, including glial fibrillary acidic protein, p21/WAF1, human TGF-beta inducible early protein, human DNA fragmentation factor 45 etc.
CONCLUSIONWild-type PTEN can affect the expressions of multiple genes, by which it regulates the proliferation, differentiation and apoptosis of glioblastomas.
Brain Neoplasms ; genetics ; Gene Expression ; Gene Expression Regulation, Neoplastic ; Glioblastoma ; genetics ; Humans ; Oligonucleotide Array Sequence Analysis ; PTEN Phosphohydrolase ; Phosphoric Monoester Hydrolases ; genetics ; physiology ; Transfection ; Tumor Cells, Cultured ; Tumor Suppressor Proteins ; genetics ; physiology