Biomedical subjects

Xiao-Ling Gao

Publications and source records attributed to Xiao-Ling Gao.

5 recordsLinked to original sources

PubMed2006

Gene therapy that inhibits NF-kappaB results in apoptosis of human hepatocarcinoma by recombinant adenovirus.

AIM: To investigate whether the recombinant adenovirus induces the TNF-alpha-mediated apoptosis in vivo. METHODS: Human hepatocarcinoma cell line (HepG(2)) cells were transfected into BALB/c nude mice, and the tumor growth curve was drawn. We analyzed apoptosis in HepG(2) cells by TUNEL, HE staining and electron microscopy. RESULTS: AdIkappaBalphaM was expressed stably and efficiently in HepG(2) and could not be degraded by induction of TNF-alpha. Tumor growth in mice could be reduced remarkably if treated by AdIkappaBalphaM plus TNF-alpha. There was apoptosis of > 70% of cells treated with AdIkappaBalphaM plus TNF-alpha and about 50% of cells treated with AdIkappaBalphaM. In contrast, there was few cell apoptosis in HepG(2) cells treated with phosphate buffered saline and AdIkappaBalpha. HepG(2) cells in mice also exhibited a high level of apoptosis after in vivo injection with AdIkappaBalphaM. The tumor growth curve indicated the tumor transfected with AdIkappaBalphaM could be restrained. CONCLUSION: AdIkappaBalphaM gene therapy greatly enhances apoptosis due to inhibition of an NF-kappaB-mediated antiapoptosis signaling pathway.

Adenoviridae↗

PubMed2006

Pharmacological profile of PMS777, a new AChE inhibitor with PAF antagonistic activity.

The key pathophysiological mechanisms in Alzheimer's disease involve the selective loss of cholinergic neurons and pro-inflammatory mediator-related chronic inflammatory responses in the brain, therefore interventions of these processes are crucial to the treatment of this disease. In the present study, the pharmacological profile of PMS777, a new acetylcholinesterase (AChE) inhibitor with platelet-activating factor (PAF) antagonistic activity, has been evaluated in vitro and in vivo. PMS777 (1-100 microM) dose-dependently inhibited PAF-induced rabbit platelet aggregation by competing with [3H]PAF for its receptor on platelets, and protected a human neuroblastoma cell line SH-SY5Y against PAF-induced neurotoxicity. Moreover, it markedly inhibited brain AChE activity in mice and showed a modest selectivity for AChE (AChE: IC50=2.48+/-0.12 microM; butyrylcholinesterase: IC50=4.47+/-0.15 microM). Ex vivo, PMS777 (5, 10, 20 or 40 mg/kg i.p.) reduced brain AChE activity in a dose-dependent manner. In-vivo studies revealed that PMS777 (0.25, 0.5, 1, 2.5 or 5 mg/kg i.p.) could reverse scopolamine-induced memory retrieval deficits in mice, and displayed a typical bell-shaped dose-response relationship. Taken together, these results demonstrate that PMS777 possesses dual activities for PAF receptor antagonism and AChE inhibition, suggesting that this compound may be a promising lead compound for further investigation related to the treatment for Alzheimer's disease.

Acetylcholinesterase↗

PubMed2006

[Progress in the study on DREB transcription factor].

DREB transcription factor is a dehydration responsive element (DRE) binding protein. It can specifically interact with the dehydration-responsive element/C-repeat (DRE/CRT) cis-acting element contained in the promoter region of many stress-inducible genes, and can therefore control the expression of many stress-inducible genes in plant and increase strong tolerance to drought, low temperature and high salt. In this paper we described the relation between DREB transcription factor and DRE/CRT cis-acting element, the functional and structural character, and expression and regulation of DREB. We also briefly introduced the progress of research on DREB gene cloning and identification. DREB transcription factor plays an important role in the expression of many stress-inducible genes in plant, so it thus shows a very broad application future in aspect of increasing strong tolerance to stress. At the same time, we described the DREB complexity in signal transduction and the mechanism for action and expression of gene.

Gene Expression Regulation, Plant↗

PubMed2005

[Anti-HBV effect of fusion protein (TA1-IFN) in vitro].

OBJECTIVE: To investigate the anti-HBV effect of fusion protein thymosin alpha1-interferon alpha (TA1-IFN) in vitro and to compare its effect with a combination of interferon alpha and thymosin alpha1. METHODS: After 2.2.15 cells were seeded for 24 hours, drugs of five serial concentrations (8000, 4000, 2000, 1000, 500 U/ml) were added to the wells, then the medium was changed every three days. After 2.2.15 cells were treated with drugs for 6 days, the medium was collected. The inhibitory rates on HBsAg and HBeAg were determined using Abbot kit, and the cytotoxicity of different drugs by means of MTT colorimetric assays was also observed. RESULTS: The inhibitory rate of fusion protein on HBsAg, HBeAg was dose-dependent and reached the maximum at 8000 U/ml concentration. In the meantime, the inhibitory rates of fusion protein on HBsAg and HBeAg were 72.2% +/- 0.8% and 60.4% +/- 1.1% respectively, and the cell survival rate was 85.2% +/- 2.0%; In the corresponding concentration, the inhibitory rates of combination thymosin alpha 1 and interferon alpha on HBsAg and HBeAg were 40.0% +/- 0.7%, 34.5% +/- 3.2% respectively. The results showed significant statistical differences between them; cell survival rate 70.0% +/- 1.9%, and the difference of the results was also significant. Cytotoxicity of fusion protein was weaker than a combination of thymosin alpha 1 and interferon alpha. CONCLUSION: Fusion protein TA1-IFN exerted stronger anti-HBV effects in vitro. Its anti-HBV effects in vitro were stronger than the combination of thymosin alpha and interferon alpha, and its cytotoxicity was weaker than the combination of thymosin alpha and interferon alpha. Our studies provided important evidence for clinical research on TA1-IFN, and also brought new hope for hepatitis B therapy.

Antiviral Agents↗

PubMed2004

High-performance liquid chromatographic analysis of zolmitriptan in human plasma using fluorescence detection.

A simple, rapid and sensitive high-performance liquid chromatographic (HPLC) method has been developed to quantify zolmitriptan in plasma using an isocratic system with fluorescence detection. The method included a single-step liquid-liquid extraction with methyl tertiary butyl ether. HPLC separation was carried out by reversed phase chromatography with a mobile phase composed of 0.05% (v/v) triethylamine in water(adjusting to pH 2.75 with 85% phosphoric acid) and acetonitrile (92:8, v/v), pumped at flow rate of 1.5 ml/min. Fluorescence detection was performed at 225 nm (excitation) and 360 nm (emission). The calibration curve for zolmitriptan was linear from 0.2 to 40 ng/ml. The validation method yielded good results regarding linearity, precision, accuracy, specificity and recoveries. The values of the limit of detection (LOD) and limit of quantification (LOQ) were 20 and 40 pg, respectively. The method was sensitive, simple and repeatable enough to be used in pharmacokinetic studies.

Adolescent↗