BACKGROUND The use of methyl-tertiary butyl ether(MTBE)to dissolve gallstones has been limited due to concerns over its toxicity and the widespread recognition of the safety of laparoscopic cholecystectomy.The adverse...BACKGROUND The use of methyl-tertiary butyl ether(MTBE)to dissolve gallstones has been limited due to concerns over its toxicity and the widespread recognition of the safety of laparoscopic cholecystectomy.The adverse effects of MTBE are largely attributed to its low boiling point,resulting in a tendency to evaporate.Therefore,if there is a material with a higher boiling point and similar or higher dissolubility than MTBE,it is expected to be an attractive alternative to MTBE.AIM To determine whether tert-amyl ethyl ether(TAEE),an MTBE analogue with a relatively higher boiling point(102°C),could be used as an alternative to MTBE in terms of gallstone dissolubility and toxicity.METHODS The in vitro dissolubility of MTBE and TAEE was determined by measuring the dry weights of human gallstones at predetermined time intervals after placing them in glass containers with either of the two solvents.The in vivo dissolubility was determined by comparing the weights of solvent-treated gallstones and control(dimethyl sulfoxide)-treated gallstones,after the direct infusion of each solvent into the gallbladder in both hamster models with cholesterol and pigmented gallstones.RESULTS The in vitro results demonstrated a 24 h TAEE-dissolubility of 76.7%,56.5%and 38.75%for cholesterol,mixed,and pigmented gallstones,respectively,which represented a 1.2-,1.4-,and 1.3-fold increase in dissolubility compared to that of MTBE.In the in vitro experiment,the 24 h-dissolubility of TAEE was 71.7%and 63.0%for cholesterol and pigmented gallstones,respectively,which represented a 1.4-and 1.9-fold increase in dissolubility compared to that of MTBE.In addition,the results of the cell viability assay and western blot analysis indicated that TAEE had a lower toxicity towards gallbladder epithelial cells than MTBE.CONCLUSION We demonstrated that TAEE has higher gallstone dissolubility properties and safety than those of MTBE.As such,TAEE could present an attractive alternative to MTBE if our findings regarding its efficacy and safety can be consistently reproduced in further subclinical and clinical studies.展开更多
TEM,FTIR and XRD techniques are used to investigate the structure of HPWA-SBA-15.The results show that pores of HPWA-SBA-15 have regular two-dimensional hexagonal structure,and HPWA disperses well in the pore or pore ...TEM,FTIR and XRD techniques are used to investigate the structure of HPWA-SBA-15.The results show that pores of HPWA-SBA-15 have regular two-dimensional hexagonal structure,and HPWA disperses well in the pore or pore wall of HPWA-SBA-15.NH3-TPD shows the HPWA-SBA-15 catalyst has acidic properties.ETBE is synthesized by the etherification reaction of alcohol and tert-butyl alcohol over several catalysts.Solid acid catalyst HPWA-SBA-15 is the appropriate catalyst which has the highest yield of ETBE than PW12/C and cation resin.The influences of reaction temperature,ratio of alcohol to tert-butyl alcohol are studied.At optimal operation condition, 30% HPWA on HPWA-SBA-15,reaction temperature 100℃,alcohol/tert-butyl alcohol molar ratio 2,the quality catalyst 0.9g and raw material 10g,the yield of ETBE is 59.55% and the selectivity is 90.2%.展开更多
文摘BACKGROUND The use of methyl-tertiary butyl ether(MTBE)to dissolve gallstones has been limited due to concerns over its toxicity and the widespread recognition of the safety of laparoscopic cholecystectomy.The adverse effects of MTBE are largely attributed to its low boiling point,resulting in a tendency to evaporate.Therefore,if there is a material with a higher boiling point and similar or higher dissolubility than MTBE,it is expected to be an attractive alternative to MTBE.AIM To determine whether tert-amyl ethyl ether(TAEE),an MTBE analogue with a relatively higher boiling point(102°C),could be used as an alternative to MTBE in terms of gallstone dissolubility and toxicity.METHODS The in vitro dissolubility of MTBE and TAEE was determined by measuring the dry weights of human gallstones at predetermined time intervals after placing them in glass containers with either of the two solvents.The in vivo dissolubility was determined by comparing the weights of solvent-treated gallstones and control(dimethyl sulfoxide)-treated gallstones,after the direct infusion of each solvent into the gallbladder in both hamster models with cholesterol and pigmented gallstones.RESULTS The in vitro results demonstrated a 24 h TAEE-dissolubility of 76.7%,56.5%and 38.75%for cholesterol,mixed,and pigmented gallstones,respectively,which represented a 1.2-,1.4-,and 1.3-fold increase in dissolubility compared to that of MTBE.In the in vitro experiment,the 24 h-dissolubility of TAEE was 71.7%and 63.0%for cholesterol and pigmented gallstones,respectively,which represented a 1.4-and 1.9-fold increase in dissolubility compared to that of MTBE.In addition,the results of the cell viability assay and western blot analysis indicated that TAEE had a lower toxicity towards gallbladder epithelial cells than MTBE.CONCLUSION We demonstrated that TAEE has higher gallstone dissolubility properties and safety than those of MTBE.As such,TAEE could present an attractive alternative to MTBE if our findings regarding its efficacy and safety can be consistently reproduced in further subclinical and clinical studies.
文摘TEM,FTIR and XRD techniques are used to investigate the structure of HPWA-SBA-15.The results show that pores of HPWA-SBA-15 have regular two-dimensional hexagonal structure,and HPWA disperses well in the pore or pore wall of HPWA-SBA-15.NH3-TPD shows the HPWA-SBA-15 catalyst has acidic properties.ETBE is synthesized by the etherification reaction of alcohol and tert-butyl alcohol over several catalysts.Solid acid catalyst HPWA-SBA-15 is the appropriate catalyst which has the highest yield of ETBE than PW12/C and cation resin.The influences of reaction temperature,ratio of alcohol to tert-butyl alcohol are studied.At optimal operation condition, 30% HPWA on HPWA-SBA-15,reaction temperature 100℃,alcohol/tert-butyl alcohol molar ratio 2,the quality catalyst 0.9g and raw material 10g,the yield of ETBE is 59.55% and the selectivity is 90.2%.
