AIM: To study the expression and serum level of HBxAg,Fas and FasL in tissues of HCC patients, and to assess the relationship between HBxAg and Fas/FasL system.METHODS: Tissues from 50 patients with HCC were tested fo...AIM: To study the expression and serum level of HBxAg,Fas and FasL in tissues of HCC patients, and to assess the relationship between HBxAg and Fas/FasL system.METHODS: Tissues from 50 patients with HCC were tested for the expression of HBxAg, Fas and FasL by S-P immunohistochemistry. Serum levels of sFas/sFasL and HBsAg/HBeAg were measured by ELISA assay. HBV X gene was detected by PCR in serum and confirmed by automatic sequencing. Fifty cases of liver cirrhosis and 30 normal controls were involved in serum analysis.RESULTS: The expression of HBxAg, Fas and FasL in carcinoma tissues was 96 %, 84 % and 98 %, respectively.Staining of HBxAg, Fas and FasL was observed predominately in cytoplasms, no significant difference was found in intensity between HBxAg, Fas and FasL (P＞0.05). HBxAg, Fas and FasL might express in the same area of carcinoma tissues and this co-expression could be found in most patients with HCC. The mean levels of sFas in serum from HCC, cirrhosis and normal controls were 762.29±391.56 μg@ L-1 835.36±407.33 μg@L-1 and 238.27±135.29 μg@L-1. The mean levels of sFasL in serum from HCC, cirrhosis and normal controls were 156.36±9.61iμg@ L-1, 173.63±18.74 μg@L-1 and 121.96±7.83 μg@ L-1.Statistical analysis showed that both sFas and sFasL in HCC and cirrhosis patients were significantly higher than those in normal controls (P＜0.01). Serum HBV X gene was found in 32 % of HCC patients and ,46 % of cirrhotic patients.There was no significant relationship between serum level of sFas/sFasL and serum X gene detection (P＞0.05). Eight percent of HCC patients with negative HBsAg and HBeAg in serum might have X gene in serum and HBxAg expression in carcinoma tissues.CONCLUSION: Our data suggest that HBxAg and Fas/FasL system plays an important role in the development of human HCC. Expression of HBxAg can leads to expression of Fas/FasL system which and reverse apoptosis of hepatocellular carcinoma induced by FasL.展开更多
The cDNA fragment of human TRAIL (TNF-related apoptosis inducing ligand) was cloned into RevTet-On, a Tetregulated and high-level gene expression system. The gene expression system was constructed in a human leukemic ...The cDNA fragment of human TRAIL (TNF-related apoptosis inducing ligand) was cloned into RevTet-On, a Tetregulated and high-level gene expression system. The gene expression system was constructed in a human leukemic cell line: Jurkat. By using RevTet-On TRAIL gene expression system in Jurkat as a cell model, we studied the influence of TRAIL gene on the changes of cellular apoptosis before and after the TRAIL gene expression, which was induced by adding tetracycline derivative doxycycline (Dox). The results indicated that the cellular apoptosis ratio was largely dependent on the TRAIL gene expression level. Moreover, it was found that the apoptosis-inducing TRAIL could cause significant changes in the biophysical properties of Jurkat cells. The cell surface charge density decreased, the membrane fluidity declined, the elastic coefficients K_I increased, and the proportion of α-helix in membrane protein secondary structure decreased. Thus, the apoptosis-inducing TRAIL gene caused significant changes on the biomechanic properties of Jurkat cells.展开更多
Synchrotron radiation small-angle X-ray scattering(SAXS) and the viscosity technique were used to investigate the effect of dissolved CO2 in toluene on the conformation of polystyrene(PS) in the solution.The viscosity...Synchrotron radiation small-angle X-ray scattering(SAXS) and the viscosity technique were used to investigate the effect of dissolved CO2 in toluene on the conformation of polystyrene(PS) in the solution.The viscosity of PS solution decreases faster with increasing antisolvent CO2 pressure than that of the solvent in the absence of the polymer.the intrinsic viscosity [η] calculated using the wellknown Huggins equation decreases with antisolvent pressure.It was found that the second virial coefficient A2 and the apparent mean-square radius of gyration<Rg^2>^1/2 decreases with pressure of antisolvent CO2.All these phenomena can be attributed to the shrink of PS chain in the course of adding the gas antisolvent because the intercation between the polymer and solvent becomes weaker.The values<Rg^2>^1/2 at different pressures obtained from SAXS data agree reasonably with those calculated from Flory theory using the viscosity data determined in this work.This implies that Flory theory,which has been used widely for the solutions of polymers in liquid solvents,is also applicable to the polymer solution with gas antisolvent.展开更多
基金the Science Foundation of Fujian Province,No.99-Z-162
文摘AIM: To study the expression and serum level of HBxAg,Fas and FasL in tissues of HCC patients, and to assess the relationship between HBxAg and Fas/FasL system.METHODS: Tissues from 50 patients with HCC were tested for the expression of HBxAg, Fas and FasL by S-P immunohistochemistry. Serum levels of sFas/sFasL and HBsAg/HBeAg were measured by ELISA assay. HBV X gene was detected by PCR in serum and confirmed by automatic sequencing. Fifty cases of liver cirrhosis and 30 normal controls were involved in serum analysis.RESULTS: The expression of HBxAg, Fas and FasL in carcinoma tissues was 96 %, 84 % and 98 %, respectively.Staining of HBxAg, Fas and FasL was observed predominately in cytoplasms, no significant difference was found in intensity between HBxAg, Fas and FasL (P＞0.05). HBxAg, Fas and FasL might express in the same area of carcinoma tissues and this co-expression could be found in most patients with HCC. The mean levels of sFas in serum from HCC, cirrhosis and normal controls were 762.29±391.56 μg@ L-1 835.36±407.33 μg@L-1 and 238.27±135.29 μg@L-1. The mean levels of sFasL in serum from HCC, cirrhosis and normal controls were 156.36±9.61iμg@ L-1, 173.63±18.74 μg@L-1 and 121.96±7.83 μg@ L-1.Statistical analysis showed that both sFas and sFasL in HCC and cirrhosis patients were significantly higher than those in normal controls (P＜0.01). Serum HBV X gene was found in 32 % of HCC patients and ,46 % of cirrhotic patients.There was no significant relationship between serum level of sFas/sFasL and serum X gene detection (P＞0.05). Eight percent of HCC patients with negative HBsAg and HBeAg in serum might have X gene in serum and HBxAg expression in carcinoma tissues.CONCLUSION: Our data suggest that HBxAg and Fas/FasL system plays an important role in the development of human HCC. Expression of HBxAg can leads to expression of Fas/FasL system which and reverse apoptosis of hepatocellular carcinoma induced by FasL.
基金This work was supported by The National Natural Science Foundation of China(No.30270355,No.39930110)a Doctoral Funding(No.20010001082).
文摘The cDNA fragment of human TRAIL (TNF-related apoptosis inducing ligand) was cloned into RevTet-On, a Tetregulated and high-level gene expression system. The gene expression system was constructed in a human leukemic cell line: Jurkat. By using RevTet-On TRAIL gene expression system in Jurkat as a cell model, we studied the influence of TRAIL gene on the changes of cellular apoptosis before and after the TRAIL gene expression, which was induced by adding tetracycline derivative doxycycline (Dox). The results indicated that the cellular apoptosis ratio was largely dependent on the TRAIL gene expression level. Moreover, it was found that the apoptosis-inducing TRAIL could cause significant changes in the biophysical properties of Jurkat cells. The cell surface charge density decreased, the membrane fluidity declined, the elastic coefficients K_I increased, and the proportion of α-helix in membrane protein secondary structure decreased. Thus, the apoptosis-inducing TRAIL gene caused significant changes on the biomechanic properties of Jurkat cells.
文摘Synchrotron radiation small-angle X-ray scattering(SAXS) and the viscosity technique were used to investigate the effect of dissolved CO2 in toluene on the conformation of polystyrene(PS) in the solution.The viscosity of PS solution decreases faster with increasing antisolvent CO2 pressure than that of the solvent in the absence of the polymer.the intrinsic viscosity [η] calculated using the wellknown Huggins equation decreases with antisolvent pressure.It was found that the second virial coefficient A2 and the apparent mean-square radius of gyration<Rg^2>^1/2 decreases with pressure of antisolvent CO2.All these phenomena can be attributed to the shrink of PS chain in the course of adding the gas antisolvent because the intercation between the polymer and solvent becomes weaker.The values<Rg^2>^1/2 at different pressures obtained from SAXS data agree reasonably with those calculated from Flory theory using the viscosity data determined in this work.This implies that Flory theory,which has been used widely for the solutions of polymers in liquid solvents,is also applicable to the polymer solution with gas antisolvent.
