Epidemiological studies support the idea that most human cancers are related to chemicals present in the human environment. In turn, chemicals are believed to cause cancer via either genotoxic or non-genotoxic mechani...Epidemiological studies support the idea that most human cancers are related to chemicals present in the human environment. In turn, chemicals are believed to cause cancer via either genotoxic or non-genotoxic mechanisms. There were described in literature several simple, rapid and inexpensive short term tests to reasonably predict the genotoxic nature of chemicals but in contrast, there is no reliable test or battery of tests available to predict the carcinogenicity of non-genotoxic compounds and this poses a major problem to their risk assessment. In addition, there are conflictive opinions about risk assessment needs for both classes of carcinogens. Some workers believe that for non-genotoxic carcinogens, thresholds for exposure can be drawn while others do not. In this review, the reasons behind both of these opinions and the present hypotheses about the mechanism of action of non-genotoxic carcinogens are described and analyzed in relation to future needs.展开更多
BACKGROUND The standard management of autoimmune hepatitis(AIH)is based on corticosteroids,alone or in combination with azathioprine.Second-line treatments are needed for patients who have refractory disease.However,h...BACKGROUND The standard management of autoimmune hepatitis(AIH)is based on corticosteroids,alone or in combination with azathioprine.Second-line treatments are needed for patients who have refractory disease.However,high-quality data on the alternative management of AIH are scarce.AIM To evaluate the efficacy and safety of tacrolimus and mycophenolate mofetil(MMF)and the quality of evidence by using the Grading of Recommendations Assessment,Development and Evaluation approach(GRADE).METHODS A systematic review and meta-analysis of the available data were performed.We calculated pooled event rates for three outcome measures:Biochemical remission,adverse events,and mortality,with their corresponding 95%confidence intervals(CI).RESULTS The pooled biochemical remission rate was 68.9%(95%CI:60.4-76.2)for tacrolimus,and 59.6%(95%CI:54.8-64.2)for MMF,and rates of adverse events were 25.5%(95%CI:12.4-45.3)for tacrolimus and 24.1%(95%CI:15.4-35.7)for MMF.The pooled mortality rate was estimated at 11.5%(95%CI:7.1-18.1)for tacrolimus and 9.01%(95%CI:6.2-12.8)for MMF.Pooled biochemical remission rates for tacrolimus and MMF in patients with intolerance to standard therapy were 56.6%(CI:43.4-56.6)vs 73.5%(CI:58.1-84.7),and among non-responders were 59.1%(CI:48.7-68.8)vs 40.8%(CI:32.3-50.0),respectively.Moreover,the overall quality assessments using GRADE proved to be very low for all our outcomes in both treatment groups.CONCLUSION Tacrolimus and MMF are in practice considered effective for patients with AIH who are non-responders or intolerant to first-line treatment,but we found no high-quality evidence to support this statement.展开更多
文摘Epidemiological studies support the idea that most human cancers are related to chemicals present in the human environment. In turn, chemicals are believed to cause cancer via either genotoxic or non-genotoxic mechanisms. There were described in literature several simple, rapid and inexpensive short term tests to reasonably predict the genotoxic nature of chemicals but in contrast, there is no reliable test or battery of tests available to predict the carcinogenicity of non-genotoxic compounds and this poses a major problem to their risk assessment. In addition, there are conflictive opinions about risk assessment needs for both classes of carcinogens. Some workers believe that for non-genotoxic carcinogens, thresholds for exposure can be drawn while others do not. In this review, the reasons behind both of these opinions and the present hypotheses about the mechanism of action of non-genotoxic carcinogens are described and analyzed in relation to future needs.
文摘BACKGROUND The standard management of autoimmune hepatitis(AIH)is based on corticosteroids,alone or in combination with azathioprine.Second-line treatments are needed for patients who have refractory disease.However,high-quality data on the alternative management of AIH are scarce.AIM To evaluate the efficacy and safety of tacrolimus and mycophenolate mofetil(MMF)and the quality of evidence by using the Grading of Recommendations Assessment,Development and Evaluation approach(GRADE).METHODS A systematic review and meta-analysis of the available data were performed.We calculated pooled event rates for three outcome measures:Biochemical remission,adverse events,and mortality,with their corresponding 95%confidence intervals(CI).RESULTS The pooled biochemical remission rate was 68.9%(95%CI:60.4-76.2)for tacrolimus,and 59.6%(95%CI:54.8-64.2)for MMF,and rates of adverse events were 25.5%(95%CI:12.4-45.3)for tacrolimus and 24.1%(95%CI:15.4-35.7)for MMF.The pooled mortality rate was estimated at 11.5%(95%CI:7.1-18.1)for tacrolimus and 9.01%(95%CI:6.2-12.8)for MMF.Pooled biochemical remission rates for tacrolimus and MMF in patients with intolerance to standard therapy were 56.6%(CI:43.4-56.6)vs 73.5%(CI:58.1-84.7),and among non-responders were 59.1%(CI:48.7-68.8)vs 40.8%(CI:32.3-50.0),respectively.Moreover,the overall quality assessments using GRADE proved to be very low for all our outcomes in both treatment groups.CONCLUSION Tacrolimus and MMF are in practice considered effective for patients with AIH who are non-responders or intolerant to first-line treatment,but we found no high-quality evidence to support this statement.
