ABSTRACT
OBJECTIVE To study the content changes of ch emical constituents of processed products of Terminalia chebula at different temperatures ，and to compare its anti-ulcerative colitis effect. METHODS Processed products of T. chebula at different temperatures（160，180，200，220，240，260，280，300 ℃）were prepared by sand scalding technology. HPLC method was adopted to determine the contents of gallic acid ，chebulagic acid ，chebulinic acid and ellagic acid in crude drug and processed products of T. chebula at different temperatures. The mice were divided into blank group ，model group ，Mesalazin enteric-coated tablets group （positive control ，0.4 g/kg），crude drug and processed products groups of T. chebula at different temperatures （1.3 g/kg），with 10 mice in each group. Except for blank group ，other groups were given 6％ acetic acid 0.1 mL via anus to induce ulcerative colitis model. After modeling ，blank group and model group were given water intragastrically ，and other groups were given relevant drug intragastrically ，20 mL/kg，once a day ，for consecutive 7 days. The general physical signs of mice in each group were observed and the body weight was recorded. The colorectal length and index ，serum levels of related inflammation indexes [superoxide dismutase （SOD），malondialdehyde （MDA），interleukin-10 （IL-10），IL-1 β ，tumor necrosis factor α （TNF-α）] were detected. The pathomorphological changes of colon and rectum were observed ，and the comprehensive score of pharmacodynamics was performed. RESULTS With the increase of processing temperature ，the contents of chebulagic acid and chebulinic acid decreased gradually ，the content of gallic acid increased first and then decreased ，and the content of ellagic acid increased. Compared with model group ，the general physical signs ，body weight ，colorectal length ，colorectal index and related inflammation indexes were all improved significantly in crude drug and processed products groups of T. chebula at different temperatures（P＜0.05 or P＜0.01）. The glandular recess structure of colorectal tissue was repaired ，the infiltration of inflammatory cells was reduced ，and the comprehensive score of efficacy of processed products prepared at 260 ℃ was the highest. CONCLUSIONS The contents of chemical components in T. chebula processed at different temperatures change significantly and their anti-ulcerative colitis effects are different. The processed products of T. chebula prepared at 260 ℃ show the best anti-ulcerative colitis effect.
ABSTRACT
Context: Most of the maxillary complete dentures do not adapt accurately to the cast because of the changes in the resin during polymerization. The amount of heat associated with processing of polymethyl methacrylate has been correlated with the adaptation of the processed denture base to its supporting tissues. Aims: This study conducted to determine the effect of different curing temperatures on the accuracy of fit of a complete maxillary denture and to compare with that of fiber-reinforced acrylic resins. Materials and Methods : An ideal maxillary rubber mould used to make an edentulous cast. Forty-eight stone casts made from the ideal rubber mould. Out of 48 identical stone casts, 44 stone casts with wax adapted processed using simple acrylic resin. The remaining four stone casts were processed using fiber-reinforced acrylic resin. However, processing time for 12 hrs was maintained constant for all the samples. The variable to investigate was the temperature. Therefore, four denture bases processed at each temperature from 60°C to 80°C with two-degree increments for a total of 44 samples using simple acrylic resin. Remaining four samples processed at 70°C using fiber-reinforced acrylic resin. A traveling microscope used to measure the discrepancy between each cast and its denture base. Statistical analysis used: Analyzed with Student's unpaired t test. Results : Minimum distortion was observed at 70°C. Maximum distortion was observed for the denture bases processed at 80°C. Amount of distortion increases as the processing temperature increases which was highly significant. Distortion was significantly high from 60 to 68°C in the decreasing order. Conclusion: This study verified the observation that maxillary complete denture base show the greatest discrepancy at the central portion of the posterior palatal seal region as the processing temperature increases.