AIM:To investigate the molecular mechanism of alphafetoprotein (AFP) on regulating the proliferation of human hepatocellular carcinoma cells.METHODS: Alpha-fetoprotein purified from human umbilical blood was added to ...AIM:To investigate the molecular mechanism of alphafetoprotein (AFP) on regulating the proliferation of human hepatocellular carcinoma cells.METHODS: Alpha-fetoprotein purified from human umbilical blood was added to cultured human hepatocellular carcinoma Bel 7402 cells in vitro for various treatment periods. The expression of c-fos, c-jun,and N-ras mRNA involved in proliferation and differentiation of cells was analyzed by Northern blot,and the expression of mutative p53 and p21^ras proteins was determined by Western blot.RESULTS:The results showed that AFP (20mg/L) stimulated mRNA expression of these oncogenes in Bel 7402 cells.The expression of c-fos mRNA increased by 51.1%,60.9%,96.0%,and 25.5% at 2, 6, 12, and 24 h, respectively.The expression of c-jun and N-ras mRNA reached to the maximum which increased by 81.3% and 59.9% as compared with the control alter 6h and 24h incubation with AFP, respectively.Western blot assay also demonstrated that AFP promoted the expression of mutative p53 and p21^ras proteins, and the increased rate of those proteins was 13.0%,39.9%, and 70.9%, as well as 35.2%, 102.6%, and 46.8% at 6, 12, and 24h,respectively, as compared with the control.Both human serum albumin (the same dosage as AFP) and monoclonal anti-AFP antibody failed to stimulate the expression of these oncogenes,but anti-AFP antibody could block the functions of AFP.CONCLUSION:The data indicate that AFP can stimulate the expression of some oncogenes to enhance the proliferation of human hepatocellular carcinoma Bel 7402 cells.展开更多
AIM: To investigate the mechanism of α-fetoprotein (AFP)in escaping from the host immune surveillance of hepatocellular carcinoma.METHODS: AFP purified from human umbilical blood was administrated into the cultured h...AIM: To investigate the mechanism of α-fetoprotein (AFP)in escaping from the host immune surveillance of hepatocellular carcinoma.METHODS: AFP purified from human umbilical blood was administrated into the cultured human lymphoma Jurkat T cell line or hepatoma cell line, Bel7402 in vitro. The expression of tumor necrosis factor related apoptosisinducing ligand (TRAIL) and its receptor (TRAILR) mRNA were analyzed by Northern blot and Western blot wasused to detect the expression of Fas and Fas ligand (FasL)protein.RESULTS: AFP (20 mg/L) could promote the expression of FasL and TRAIL, and inhibit the expression of Fas and TRAILR of Bel7402 cells. For Jurkat cell line, AFP could suppress the expression of FasL and TRAIL, and stimulate the expression of Fas and TRAILR. AFP also could synergize with Bel7402 cells to inhibit the expression of FasL protein and TRAIL mRNA in Jurkat cells. The monoclonal antibody against AFP (anti-AFP) could abolish these functions of AFP.CONCLUSION: AFP is able to promote the expression of FasL and TRAIL in hepatoma cells and enhance the expression of Fas and TRAILR in lymphocytes. These could elicit the escape of hepatocellular carcinoma cells from the host's lymphocytes immune surveillance.展开更多
AIM: To investigate experimentally the effects of methionineenkephalin on signal transduction of mouse myeloma NS-1cells.METHODS: The antigen determinate of delta opioidreceptor was designed in this lab and the polype...AIM: To investigate experimentally the effects of methionineenkephalin on signal transduction of mouse myeloma NS-1cells.METHODS: The antigen determinate of delta opioidreceptor was designed in this lab and the polypeptidefragment of antigen determinate with 12 amino acidsresidues was synthesized. Monoclonal antibody against thispeptide fragment was prepared. Proliferation of Mouse NS-L cells treated with methionine enkephalin of 1x10-6 mol.L-1was observed. The activities of protein kinase A (PKA) andprotein kinase C (PKC) were measured and thereby themechanism of effect of methionine enkephalin was postulated.RESULTS: The results demonstrated that methionineenkephalin could enhance the proliferation of NS-1 cells andthe effect of methionine enkephalin could be particularlyblocked by monoclonal antibody. The activity of PKA wasincreased in both cytosol and cell membrane. With referenceto PKC, the intracellular activity of PKC in NS-1 cells waselevated at 1x10-7 mol.L-1 and then declined gradually asthe concentration of methionine enkephalin was raised. Theeffects of methionine enkephalin might be reversed by bothnaloxone and monoclonal antibody.CONCLUSION: Coupled with the findings, it in-dicates thatthe signal transduction systems via PKA and PKC are involvedin the effects of methionine enkephalin by binding with thetraditional opioid receptors, and therefore resulting in differentbiological effects.展开更多
Ixeris chinesis (Thunb.) Ankai has been used as a Chinese folk medicine, but only scanty information is available on the physiological and biochemical functions of the compounds extracted from I. chinesis. In the pre...Ixeris chinesis (Thunb.) Ankai has been used as a Chinese folk medicine, but only scanty information is available on the physiological and biochemical functions of the compounds extracted from I. chinesis. In the present study the effects of apigenin -7-glucoside (APIG) isolated from I. chinesis against liver injury caused by carbon tetrachloride (CCl4) were investigated. Methods The contents of malondialdehyde (MDA), glutamic pyruvic transaminase (GPT), glutamic oxaloacetic transaminase (GOT), and reduced glutathione (GSH) were evaluated by spectrophotography. The content of 8-Hydroxydeoxyguanosine (8-OHdG) was measured with high-performance liquid chromatography (HPLC) equipped with electrochemical and UV detection methods. The antioxidant activity of APIG was evaluated using chemiluminescence single photon counting technology. Results CCl4 significantly increased the enzyme activities of GPT and GOT in blood serum, as well as the level of MDA and 8-OHdG in liver tissue, and decreased the levels of GSH. Pretreatment with APIG was able not only to suppress the elevation of GPT, GOT, MDA and 8-OHdG, and inhibit the reduction of GSH in a dose-dependent manner in vivo, but also to reduce the damage of hepatocytes in vitro. On the other hand, we also found that APIG had strong antioxidant activity against reactive oxygen species (ROS) in vitro in a concentration-dependent manner. Conclusion The hepatoprotective activity of APIG is possibly due to its antioxidant properties, acting as scavengers of ROS. These results obtained in vivo and in vitro suggest that APIG has protective effects against hepatic oxidative injury induced by chemicals. Further studies on the pharmaceutical functions and immunological responses of APIG may help its clinical application.展开更多
It is reported for the first time that the Pt/C catalyst can be prepared with a new and simple organic sol method using SnCl2 as the reductant. It was found that the average size of the Pt particles in the Pt/C cataly...It is reported for the first time that the Pt/C catalyst can be prepared with a new and simple organic sol method using SnCl2 as the reductant. It was found that the average size of the Pt particles in the Pt/C catalysts could be controlled with controlling the preparation conditions. The effect of the average sizes of the Pt particles in the Pt/C catalysts obtained with this method on the electrocatalytical activity of the oxidation of methanol was investigated.展开更多
Diamond-like carbon coatings have been used as solid lubricating coatings in vacuum technology for their good physical and chemical properties. In this paper, the hybrid technique of unbalanced magnetron sputtering an...Diamond-like carbon coatings have been used as solid lubricating coatings in vacuum technology for their good physical and chemical properties. In this paper, the hybrid technique of unbalanced magnetron sputtering and plasma immersion ion implantation (Plll) was adopted to fabricate diamond-like carbon-based functionally gradient film, N/TiN/Ti(N,C)/DLC, on the 304 stainless steel substrate. The film was characterized by using Raman spectroscopy and glancing X-ray diffraction (GXRD), and the topography and surface roughness of the film was observed using AFM. The mechanical properties of the film were evaluated by nano-indentation. The results showed that the surface roughness of the film was approximately 0.732 nm. The hardness and elastic modulus, fracture toughness and interfacial fracture toughness of N/TiN/Ti(N,C)/DLC functionally gradient film were about 19.84 GPa, 190.03 GPa, 3.75 MRa.m1/2 and 5.68 MPa.m1/2, respectively. Compared with that of DLC monolayer and C/TiC/DLC multilayer, this DLC gradient film has better qualities as a solid lubricating coating.展开更多
The stability of three forms of nateglinide, especially S-form and H-form, was determined. S-form was a new crystal structure1 of nateglinide. Three forms of nateglinide were treated in different conditions, such as...The stability of three forms of nateglinide, especially S-form and H-form, was determined. S-form was a new crystal structure1 of nateglinide. Three forms of nateglinide were treated in different conditions, such as in various temperatures, humidity, light and so on. Analysis of their crystal structures was performed by X-ray powder diffraction ( XRD ) and their particle shapes were observed with scanning electron microscope ( SEM ). The results indicated that the stability of S-form of nateglinide is the best among the three forms and their particle shapes are quite difference. S-form is the sheet structure of layer upon layer, H-form looks like a hank of silk lines and B-form is the clubbed shape.展开更多
New Ge/SiO_2 glasses have been synthesized by heating the GeO_2/SiO_2 dry gels under H_2gas at 700℃. The resulting fluorescence spectra show that this kind of Ge/SiO_2 glasses emit strongphotoluminescence at 392 nm (...New Ge/SiO_2 glasses have been synthesized by heating the GeO_2/SiO_2 dry gels under H_2gas at 700℃. The resulting fluorescence spectra show that this kind of Ge/SiO_2 glasses emit strongphotoluminescence at 392 nm (3.12 eV), medium strong photoluminescence at 600 nm (2.05 eV)and weak photoluminescence at 770 nm (1.60 eV) respectively. Possible photoluminescencemechanisms are also discussed based on the results of X-ray diffraction (XRD) and X-rayphotoelectron spectra(XPS).展开更多
基金Supported by the National Natural Science Foundation of China,No.30260117Natural Science Foundation of Hainan Province,No.30315 the Nursery Foundation of Hainan Medical College,No.200202
文摘AIM:To investigate the molecular mechanism of alphafetoprotein (AFP) on regulating the proliferation of human hepatocellular carcinoma cells.METHODS: Alpha-fetoprotein purified from human umbilical blood was added to cultured human hepatocellular carcinoma Bel 7402 cells in vitro for various treatment periods. The expression of c-fos, c-jun,and N-ras mRNA involved in proliferation and differentiation of cells was analyzed by Northern blot,and the expression of mutative p53 and p21^ras proteins was determined by Western blot.RESULTS:The results showed that AFP (20mg/L) stimulated mRNA expression of these oncogenes in Bel 7402 cells.The expression of c-fos mRNA increased by 51.1%,60.9%,96.0%,and 25.5% at 2, 6, 12, and 24 h, respectively.The expression of c-jun and N-ras mRNA reached to the maximum which increased by 81.3% and 59.9% as compared with the control alter 6h and 24h incubation with AFP, respectively.Western blot assay also demonstrated that AFP promoted the expression of mutative p53 and p21^ras proteins, and the increased rate of those proteins was 13.0%,39.9%, and 70.9%, as well as 35.2%, 102.6%, and 46.8% at 6, 12, and 24h,respectively, as compared with the control.Both human serum albumin (the same dosage as AFP) and monoclonal anti-AFP antibody failed to stimulate the expression of these oncogenes,but anti-AFP antibody could block the functions of AFP.CONCLUSION:The data indicate that AFP can stimulate the expression of some oncogenes to enhance the proliferation of human hepatocellular carcinoma Bel 7402 cells.
基金Supported by the National Natural Science Foundation of China,No. 30260117 and 30271174 the Natural Science Foundation of Hainan Province, No. 30315 the Educational Key Foundation of Hainan Province, No. 200322 the Nursery Foundation of Hainan Medical College, No. 200202
文摘AIM: To investigate the mechanism of α-fetoprotein (AFP)in escaping from the host immune surveillance of hepatocellular carcinoma.METHODS: AFP purified from human umbilical blood was administrated into the cultured human lymphoma Jurkat T cell line or hepatoma cell line, Bel7402 in vitro. The expression of tumor necrosis factor related apoptosisinducing ligand (TRAIL) and its receptor (TRAILR) mRNA were analyzed by Northern blot and Western blot wasused to detect the expression of Fas and Fas ligand (FasL)protein.RESULTS: AFP (20 mg/L) could promote the expression of FasL and TRAIL, and inhibit the expression of Fas and TRAILR of Bel7402 cells. For Jurkat cell line, AFP could suppress the expression of FasL and TRAIL, and stimulate the expression of Fas and TRAILR. AFP also could synergize with Bel7402 cells to inhibit the expression of FasL protein and TRAIL mRNA in Jurkat cells. The monoclonal antibody against AFP (anti-AFP) could abolish these functions of AFP.CONCLUSION: AFP is able to promote the expression of FasL and TRAIL in hepatoma cells and enhance the expression of Fas and TRAILR in lymphocytes. These could elicit the escape of hepatocellular carcinoma cells from the host's lymphocytes immune surveillance.
基金National Science Foundation of China,No.30060091
文摘AIM: To investigate experimentally the effects of methionineenkephalin on signal transduction of mouse myeloma NS-1cells.METHODS: The antigen determinate of delta opioidreceptor was designed in this lab and the polypeptidefragment of antigen determinate with 12 amino acidsresidues was synthesized. Monoclonal antibody against thispeptide fragment was prepared. Proliferation of Mouse NS-L cells treated with methionine enkephalin of 1x10-6 mol.L-1was observed. The activities of protein kinase A (PKA) andprotein kinase C (PKC) were measured and thereby themechanism of effect of methionine enkephalin was postulated.RESULTS: The results demonstrated that methionineenkephalin could enhance the proliferation of NS-1 cells andthe effect of methionine enkephalin could be particularlyblocked by monoclonal antibody. The activity of PKA wasincreased in both cytosol and cell membrane. With referenceto PKC, the intracellular activity of PKC in NS-1 cells waselevated at 1x10-7 mol.L-1 and then declined gradually asthe concentration of methionine enkephalin was raised. Theeffects of methionine enkephalin might be reversed by bothnaloxone and monoclonal antibody.CONCLUSION: Coupled with the findings, it in-dicates thatthe signal transduction systems via PKA and PKC are involvedin the effects of methionine enkephalin by binding with thetraditional opioid receptors, and therefore resulting in differentbiological effects.
基金This work was supported by the Key Grant Project of the Ministry of Education of China (No.03076).
文摘Ixeris chinesis (Thunb.) Ankai has been used as a Chinese folk medicine, but only scanty information is available on the physiological and biochemical functions of the compounds extracted from I. chinesis. In the present study the effects of apigenin -7-glucoside (APIG) isolated from I. chinesis against liver injury caused by carbon tetrachloride (CCl4) were investigated. Methods The contents of malondialdehyde (MDA), glutamic pyruvic transaminase (GPT), glutamic oxaloacetic transaminase (GOT), and reduced glutathione (GSH) were evaluated by spectrophotography. The content of 8-Hydroxydeoxyguanosine (8-OHdG) was measured with high-performance liquid chromatography (HPLC) equipped with electrochemical and UV detection methods. The antioxidant activity of APIG was evaluated using chemiluminescence single photon counting technology. Results CCl4 significantly increased the enzyme activities of GPT and GOT in blood serum, as well as the level of MDA and 8-OHdG in liver tissue, and decreased the levels of GSH. Pretreatment with APIG was able not only to suppress the elevation of GPT, GOT, MDA and 8-OHdG, and inhibit the reduction of GSH in a dose-dependent manner in vivo, but also to reduce the damage of hepatocytes in vitro. On the other hand, we also found that APIG had strong antioxidant activity against reactive oxygen species (ROS) in vitro in a concentration-dependent manner. Conclusion The hepatoprotective activity of APIG is possibly due to its antioxidant properties, acting as scavengers of ROS. These results obtained in vivo and in vitro suggest that APIG has protective effects against hepatic oxidative injury induced by chemicals. Further studies on the pharmaceutical functions and immunological responses of APIG may help its clinical application.
文摘It is reported for the first time that the Pt/C catalyst can be prepared with a new and simple organic sol method using SnCl2 as the reductant. It was found that the average size of the Pt particles in the Pt/C catalysts could be controlled with controlling the preparation conditions. The effect of the average sizes of the Pt particles in the Pt/C catalysts obtained with this method on the electrocatalytical activity of the oxidation of methanol was investigated.
基金The authors are thankful for the financial support of the key lab of precisiok precision processing of harbin institute of technology china ,the help of the school material science and engineering,harbin institute of technology,for the ion implantation e
文摘Diamond-like carbon coatings have been used as solid lubricating coatings in vacuum technology for their good physical and chemical properties. In this paper, the hybrid technique of unbalanced magnetron sputtering and plasma immersion ion implantation (Plll) was adopted to fabricate diamond-like carbon-based functionally gradient film, N/TiN/Ti(N,C)/DLC, on the 304 stainless steel substrate. The film was characterized by using Raman spectroscopy and glancing X-ray diffraction (GXRD), and the topography and surface roughness of the film was observed using AFM. The mechanical properties of the film were evaluated by nano-indentation. The results showed that the surface roughness of the film was approximately 0.732 nm. The hardness and elastic modulus, fracture toughness and interfacial fracture toughness of N/TiN/Ti(N,C)/DLC functionally gradient film were about 19.84 GPa, 190.03 GPa, 3.75 MRa.m1/2 and 5.68 MPa.m1/2, respectively. Compared with that of DLC monolayer and C/TiC/DLC multilayer, this DLC gradient film has better qualities as a solid lubricating coating.
基金The authors gratefully acknowledge the support of the Natural Science Foundation of Jiangsu Province(BK2001111)Jiangsu Province Key Lab of Drug Delivery System(DDS200101)the Key Material Lab of Nanjing Normal University.
文摘The stability of three forms of nateglinide, especially S-form and H-form, was determined. S-form was a new crystal structure1 of nateglinide. Three forms of nateglinide were treated in different conditions, such as in various temperatures, humidity, light and so on. Analysis of their crystal structures was performed by X-ray powder diffraction ( XRD ) and their particle shapes were observed with scanning electron microscope ( SEM ). The results indicated that the stability of S-form of nateglinide is the best among the three forms and their particle shapes are quite difference. S-form is the sheet structure of layer upon layer, H-form looks like a hank of silk lines and B-form is the clubbed shape.
文摘New Ge/SiO_2 glasses have been synthesized by heating the GeO_2/SiO_2 dry gels under H_2gas at 700℃. The resulting fluorescence spectra show that this kind of Ge/SiO_2 glasses emit strongphotoluminescence at 392 nm (3.12 eV), medium strong photoluminescence at 600 nm (2.05 eV)and weak photoluminescence at 770 nm (1.60 eV) respectively. Possible photoluminescencemechanisms are also discussed based on the results of X-ray diffraction (XRD) and X-rayphotoelectron spectra(XPS).
