AIMS To report the first experience in China in the treatment of malignant biliary obstruction with expand- able metal stent which allows the insertion of an endo- prosthesis as large as one cm in diameter. METHODS Be...AIMS To report the first experience in China in the treatment of malignant biliary obstruction with expand- able metal stent which allows the insertion of an endo- prosthesis as large as one cm in diameter. METHODS Between April 1994 and May 1996,we implanted expandable metal stents in 57 patients with incurable malignant biliary obstruction,among whom 54 underwent endoscopic procedure and the other 3 re- ceived percutaneous transhepatic placement. RESULTS Insertion of the stent following guidewire positioning was successful in 95% of the patients. Two patients developed cholangitis after stent insertion and were successfully treated with conservative treatment. The jaundice was eliminated completely in 21 cases and markedly decreased in 23 cases within 2 weeks af- ter placement of the stent. Nine patients,however, had late cholangitis due to stent failure after a median interval of 14 days. Twenty-three cases underwent na- sobiliary transient drainage and 3 underwent plastic stent transient drainage prior to metal stent insertion. Transient drainage was believed to have the advan- tages of drainage pre-assessment and infection controlling. CONCLUSIONS Our results show that expandable metal stent is suitable for the irresectable malignant choledochal stenosis. It can eliminate the jaundice and improve the patient's life quality. To get the highest benefit,however,the indication should be strictly selected. And to get long-term patency,the proximal and distal end of the stent proceeding the tumor should be no shorter than 2cm. In the case of hilar cancer, Bismuth classification is greatly helpful for the choice of drainage site.展开更多
The intracellular free calcium concentration plays a key role as the second messenger in the regulation of cellular reaction.The changes of cytoplasmic free calcium concentration([Ca^(2+)]_i) in human platelets loaded...The intracellular free calcium concentration plays a key role as the second messenger in the regulation of cellular reaction.The changes of cytoplasmic free calcium concentration([Ca^(2+)]_i) in human platelets loaded with the fluorescent calcium indicator quin-2 were measured in this study. The result showed that thrombin(0.3 U/ml)raised the[Ca^(2+)]_i of platelets four to five times in the presence of 1 mmol/L external calcium.but there was a much smaller increase in[Ca^(2+)]_i in the absence of external calcium.It seems that thrombin increased[Ca^(2+)]_i partly by release of internal Ca^(2+),but mainly by stimulating influx.J-894 markedly inhibited the rise of[Ca^(2+)]_i in platelets induced by thrombin in a dose dependent manner through decreasing both calcium influx and calcium release.This suggests that J-894 may be a calcium channel blocker.展开更多
Objective: To compare metal versus plastic biliary stent implantation for treatment of malignant biliary obstruction in cost-effectiveness ratio (CER). Methods: Percutaneous transhepatic self-expandable metal stent (M...Objective: To compare metal versus plastic biliary stent implantation for treatment of malignant biliary obstruction in cost-effectiveness ratio (CER). Methods: Percutaneous transhepatic self-expandable metal stent (MS, n=61) or 10F plastic stent (PS, n=34) implantation was performed in 95 patients with malignant biliary obstruction in three hospitals of Guangdong province. All patients were followed up until death or at least one year after the procedure. Kaplan-Meier analysis was used to compare the survival and stent patency rates of the patients in the two groups. CERs of two groups were calculated. The main indexes were CERsurvival period (total cost/median survival period), CERpatency period (total cost/median patency period). Results: The total costs of treatment were 53177±3139 yuan (RMB) in MS group and 42564±4950 yuan (RMB) in PS group respectively (P>0.05). CER in MS group was superior to that in PS group (CERsurvival period was 237.4 yuan /d vs 452.6 yuan /d, respectively; CERpatency period was 231.2 yuan /d vs 472.9 yuan /d, respectively). Conclusion: The metal stent implantation is superior to the plastic stent in the CER for treatment of malignant biliary obstruction.展开更多
A solid-phase sintering process for the low-cost fabrication of composite micro-channels was developed. Three kinds of composite micro-channels with metallic porous structures were designed. The sintering process was ...A solid-phase sintering process for the low-cost fabrication of composite micro-channels was developed. Three kinds of composite micro-channels with metallic porous structures were designed. The sintering process was studied and optimized to obtain porous-structured micro-channels with high porosity. The flow resistance and heat transfer performance in the composite micro-channels were investigated. The composite micro-channels show acceptable flow resistance, significant enhancement of heat transfer and dramatic improvement of flow boiling stability, which indicates a promising prospect for the application in forced convective heat transfer.展开更多
Objective To study the antineoplastic effect of the calcium channel blocker verapamil and 5-fluorouracil intraperitoneal chemotherapy onhepatocarcinoma-bearing rats, and examine the action between calcium channel bloc...Objective To study the antineoplastic effect of the calcium channel blocker verapamil and 5-fluorouracil intraperitoneal chemotherapy onhepatocarcinoma-bearing rats, and examine the action between calcium channel blockers and cytotoxic drugs.Methods We adopted the method of subcapsular implantation of carcinoma tissues of walker-256 in the left liver lobe as a model of livercarcinoma-bearing rats. All experimental animals were divided into four groups. On the sixth day post implantation, in group A (controlgroup) 6 ml of saline was injected intraperitoneally once a day for 3 days. In group B (single chemotherapy group) 6 ml of 5-Fu 75 mg/kg was injected intraperitoneally once a day for 3 days. In group C (combination of treatment group) both 5-Fu (75 mg/kg) and verapamil(25 mg/kg) were administered simultaneously as in A and B. In group D (simple verapamil group) only 6 ml of verapamil (25 mg/kg)was administered as above.Results Compared with groups A, B and D, The volume of cancer and the contents of liver cancer DNA and protein were significantlyreduced. The rates of inhibiting cancer (89.9% in group C and 35.4% in group B) were significantly increased in group C. Group C hadsignificantly long survival time compared to groups A, B and D ( P < 0.05) . By light microscopy, a number of focal necroses were foundin cancer tissue in group C.Conclusion Calcium channel blockers can enhance the antineoplastic effect of 5-Fu intraperitoneal chemotherapy to liver cancer ; Theuse of verapamil can not increase the toxicity of 5-Fu.展开更多
\ The effects of tetrandrine (Tet) on cytosolic free calcium ([Ca2+]i) in subcultured bovine aortic smooth muscle cells (SMC) were studied by Fura2 and ARCMMIC cation measurement system. Tet (1～100 μmol·L-1) ...\ The effects of tetrandrine (Tet) on cytosolic free calcium ([Ca2+]i) in subcultured bovine aortic smooth muscle cells (SMC) were studied by Fura2 and ARCMMIC cation measurement system. Tet (1～100 μmol·L-1) had no effect on the resting [Ca2+]i, but had inhibitory effects on [Ca2+]i elevation induced by high K+, 5HT, ATP, Ang II and NE in the presence of extracellular Ca2+. High concentration of Tet also inhibited Pheinduced [Ca2+]i elevation in absence of extracellular Ca2+. Tet (1～100 μmol·L-1) inhibited KCl (60 mmol·L-1) induced [Ca2+]i elevation in dosedependent manner, the IC50 value was 9.2 (95% confidence limits: 5.7～14.9) mmol·L-1. The results suggested that Tet had blocking effects on both VOC and ROC in bovine aortic SMC. It appears that the mechanisms of blocking effect of Tet on ROC might be primarily due to its Ca2+ entry blocking effects.展开更多
文摘AIMS To report the first experience in China in the treatment of malignant biliary obstruction with expand- able metal stent which allows the insertion of an endo- prosthesis as large as one cm in diameter. METHODS Between April 1994 and May 1996,we implanted expandable metal stents in 57 patients with incurable malignant biliary obstruction,among whom 54 underwent endoscopic procedure and the other 3 re- ceived percutaneous transhepatic placement. RESULTS Insertion of the stent following guidewire positioning was successful in 95% of the patients. Two patients developed cholangitis after stent insertion and were successfully treated with conservative treatment. The jaundice was eliminated completely in 21 cases and markedly decreased in 23 cases within 2 weeks af- ter placement of the stent. Nine patients,however, had late cholangitis due to stent failure after a median interval of 14 days. Twenty-three cases underwent na- sobiliary transient drainage and 3 underwent plastic stent transient drainage prior to metal stent insertion. Transient drainage was believed to have the advan- tages of drainage pre-assessment and infection controlling. CONCLUSIONS Our results show that expandable metal stent is suitable for the irresectable malignant choledochal stenosis. It can eliminate the jaundice and improve the patient's life quality. To get the highest benefit,however,the indication should be strictly selected. And to get long-term patency,the proximal and distal end of the stent proceeding the tumor should be no shorter than 2cm. In the case of hilar cancer, Bismuth classification is greatly helpful for the choice of drainage site.
文摘The intracellular free calcium concentration plays a key role as the second messenger in the regulation of cellular reaction.The changes of cytoplasmic free calcium concentration([Ca^(2+)]_i) in human platelets loaded with the fluorescent calcium indicator quin-2 were measured in this study. The result showed that thrombin(0.3 U/ml)raised the[Ca^(2+)]_i of platelets four to five times in the presence of 1 mmol/L external calcium.but there was a much smaller increase in[Ca^(2+)]_i in the absence of external calcium.It seems that thrombin increased[Ca^(2+)]_i partly by release of internal Ca^(2+),but mainly by stimulating influx.J-894 markedly inhibited the rise of[Ca^(2+)]_i in platelets induced by thrombin in a dose dependent manner through decreasing both calcium influx and calcium release.This suggests that J-894 may be a calcium channel blocker.
文摘Objective: To compare metal versus plastic biliary stent implantation for treatment of malignant biliary obstruction in cost-effectiveness ratio (CER). Methods: Percutaneous transhepatic self-expandable metal stent (MS, n=61) or 10F plastic stent (PS, n=34) implantation was performed in 95 patients with malignant biliary obstruction in three hospitals of Guangdong province. All patients were followed up until death or at least one year after the procedure. Kaplan-Meier analysis was used to compare the survival and stent patency rates of the patients in the two groups. CERs of two groups were calculated. The main indexes were CERsurvival period (total cost/median survival period), CERpatency period (total cost/median patency period). Results: The total costs of treatment were 53177±3139 yuan (RMB) in MS group and 42564±4950 yuan (RMB) in PS group respectively (P>0.05). CER in MS group was superior to that in PS group (CERsurvival period was 237.4 yuan /d vs 452.6 yuan /d, respectively; CERpatency period was 231.2 yuan /d vs 472.9 yuan /d, respectively). Conclusion: The metal stent implantation is superior to the plastic stent in the CER for treatment of malignant biliary obstruction.
基金Project(51146010)supported by the National Natural Science Foundation of ChinaProject(S2011040003189)supported by the Doctoral Research Fund of Guangdong Natural Science Foundation,ChinaProject supported by the Fundation of Key Laboratory of Surface Functional Structure Manufacturing of Guangdong Higher Education Institutes,South China University of Technology
文摘A solid-phase sintering process for the low-cost fabrication of composite micro-channels was developed. Three kinds of composite micro-channels with metallic porous structures were designed. The sintering process was studied and optimized to obtain porous-structured micro-channels with high porosity. The flow resistance and heat transfer performance in the composite micro-channels were investigated. The composite micro-channels show acceptable flow resistance, significant enhancement of heat transfer and dramatic improvement of flow boiling stability, which indicates a promising prospect for the application in forced convective heat transfer.
文摘Objective To study the antineoplastic effect of the calcium channel blocker verapamil and 5-fluorouracil intraperitoneal chemotherapy onhepatocarcinoma-bearing rats, and examine the action between calcium channel blockers and cytotoxic drugs.Methods We adopted the method of subcapsular implantation of carcinoma tissues of walker-256 in the left liver lobe as a model of livercarcinoma-bearing rats. All experimental animals were divided into four groups. On the sixth day post implantation, in group A (controlgroup) 6 ml of saline was injected intraperitoneally once a day for 3 days. In group B (single chemotherapy group) 6 ml of 5-Fu 75 mg/kg was injected intraperitoneally once a day for 3 days. In group C (combination of treatment group) both 5-Fu (75 mg/kg) and verapamil(25 mg/kg) were administered simultaneously as in A and B. In group D (simple verapamil group) only 6 ml of verapamil (25 mg/kg)was administered as above.Results Compared with groups A, B and D, The volume of cancer and the contents of liver cancer DNA and protein were significantlyreduced. The rates of inhibiting cancer (89.9% in group C and 35.4% in group B) were significantly increased in group C. Group C hadsignificantly long survival time compared to groups A, B and D ( P < 0.05) . By light microscopy, a number of focal necroses were foundin cancer tissue in group C.Conclusion Calcium channel blockers can enhance the antineoplastic effect of 5-Fu intraperitoneal chemotherapy to liver cancer ; Theuse of verapamil can not increase the toxicity of 5-Fu.
文摘\ The effects of tetrandrine (Tet) on cytosolic free calcium ([Ca2+]i) in subcultured bovine aortic smooth muscle cells (SMC) were studied by Fura2 and ARCMMIC cation measurement system. Tet (1～100 μmol·L-1) had no effect on the resting [Ca2+]i, but had inhibitory effects on [Ca2+]i elevation induced by high K+, 5HT, ATP, Ang II and NE in the presence of extracellular Ca2+. High concentration of Tet also inhibited Pheinduced [Ca2+]i elevation in absence of extracellular Ca2+. Tet (1～100 μmol·L-1) inhibited KCl (60 mmol·L-1) induced [Ca2+]i elevation in dosedependent manner, the IC50 value was 9.2 (95% confidence limits: 5.7～14.9) mmol·L-1. The results suggested that Tet had blocking effects on both VOC and ROC in bovine aortic SMC. It appears that the mechanisms of blocking effect of Tet on ROC might be primarily due to its Ca2+ entry blocking effects.
