AIM： To explore the interaction models of the cytochrome P-450 （CYP） 1A1 Valvariant and glutathione S-transferase （GST） M1 null polymorphisms with tobacco smoking in the occurrence of intestinal gastric cancer. M...AIM： To explore the interaction models of the cytochrome P-450 （CYP） 1A1 Valvariant and glutathione S-transferase （GST） M1 null polymorphisms with tobacco smoking in the occurrence of intestinal gastric cancer. METHODS： A community-based case-control study was conducted in Yangzhong. Subjects included 114 intestinal types of gastric cancer with endoscopic and pathological diagnosis during January 1997 and December 1998, and 693 controls selected from their spouse, siblings or siblingsin-law who had no history of digestive system cancer. Logistic regression was used to estimate the interaction models. RESULTS： The frequency of the CYPIA1 Valvariant allele in cases did not differ from that in controls. The OR of GSTM1 null genotype was 2.0 （95% confidence interval [95%CI]： 1.2-3.1, P〈0.01）. It showed a significant type 2 form of interaction model when both CYPIA1 Valvariant allele and former tobacco smoking existed （i.e., among the multiplicative effects, the disease risk is increased by the tobacco exposure alone but not by the CYPIA1 variant alone）. The interaction index y was 2.8, and OReg （95%CI） was 5.0 （1.9-13.4）. GSTM1 null genctype and former tobacco smoking were significant in a type 4 interaction model （i.e., the disease risk is increased by GSTM1 null genotype or tobacco exposure alone among the multiplicative effects）. The interaction index y and OReg （95%CI） were 3.4 and 8.4 （3.4-20.9）, respectively.CONCLUSION： Different interaction models of CYPIA1 Valvariant allele and GSTM1 null genotype with tobacco smoking will contribute to understanding carcinogenic mechanism, but there is a need to further investigate in larger scale studies.展开更多
Background： Smokeless tobacco is widely used by athletes to enhance performance. Nicotine is a central nervous system stimulant and acts on cardiocirculatory and metabolic systems, involving tissue blood flow and cir...Background： Smokeless tobacco is widely used by athletes to enhance performance. Nicotine is a central nervous system stimulant and acts on cardiocirculatory and metabolic systems, involving tissue blood flow and circulatory vasoreactivity. The aim of this study was to investigate the effects of the oral smokeless tobacco （Swedish snus （SS）） on the perception of fatigue and time to exhaustion （TTE） during moderate-intensity aerobic exercise. Methods： Fourteen healthy non-tobacco male users were recruited for a double-blind, controlled crossover design （SS vs. snus placebo （SP））. Subjects were tested for 3 sessions： experimental session 1 （Exp 1） consisted of an incremental test to determine the maximal aerobic power out-put （Wmax）, whereas Exp2 and Exp3 consisted of exercising at 65%Wmax until exhaustion in SS or SP conditions. During Exp2 and Exp3, muscle and cerebral oxygenation was assessed by means of near-infrared spectroscopy, and the rating of perceived exertion （RPE） was recorded. Results： Comparing SS with SP tests, significant differences （p 〈 0.05） were found in the values of cerebral （-3%） and muscular tissues oxygenation （-4%） in the first 30 min of exercise. The RPE values were not significantly different between the 2 conditions （SS vs. SP）. No significant difference was found in TTE （SS： 54.25 ± 21.84 min; SP： 50.01 ± 17.03 min）. Conclusion： This study showed that muscular and cerebral oxygenation increased significantly with snus administration during an endurance exercise until exhaustion, but this did not affect fatigue perception and TTE. The results showed that snus could not be considered an ergogenic substance in non-tobacco users.2018 Published by Elsevier B.V. on behalf of Shanghai University of Sport. This is an open access article under the CC BY-NC-ND license. （http：//creativecommons.org/licenses/by-nc-nd/4.0/）.展开更多
基金Supported by the National Natural Science Foundation of China, No. 30170827 and 30070671
文摘AIM： To explore the interaction models of the cytochrome P-450 （CYP） 1A1 Valvariant and glutathione S-transferase （GST） M1 null polymorphisms with tobacco smoking in the occurrence of intestinal gastric cancer. METHODS： A community-based case-control study was conducted in Yangzhong. Subjects included 114 intestinal types of gastric cancer with endoscopic and pathological diagnosis during January 1997 and December 1998, and 693 controls selected from their spouse, siblings or siblingsin-law who had no history of digestive system cancer. Logistic regression was used to estimate the interaction models. RESULTS： The frequency of the CYPIA1 Valvariant allele in cases did not differ from that in controls. The OR of GSTM1 null genotype was 2.0 （95% confidence interval [95%CI]： 1.2-3.1, P〈0.01）. It showed a significant type 2 form of interaction model when both CYPIA1 Valvariant allele and former tobacco smoking existed （i.e., among the multiplicative effects, the disease risk is increased by the tobacco exposure alone but not by the CYPIA1 variant alone）. The interaction index y was 2.8, and OReg （95%CI） was 5.0 （1.9-13.4）. GSTM1 null genctype and former tobacco smoking were significant in a type 4 interaction model （i.e., the disease risk is increased by GSTM1 null genotype or tobacco exposure alone among the multiplicative effects）. The interaction index y and OReg （95%CI） were 3.4 and 8.4 （3.4-20.9）, respectively.CONCLUSION： Different interaction models of CYPIA1 Valvariant allele and GSTM1 null genotype with tobacco smoking will contribute to understanding carcinogenic mechanism, but there is a need to further investigate in larger scale studies.
基金supported by research funds allocated to the following departments at the University of Verona:Neurosciences,Biomedicine and Movement Sciences,and Diagnostic and Public Health
文摘Background： Smokeless tobacco is widely used by athletes to enhance performance. Nicotine is a central nervous system stimulant and acts on cardiocirculatory and metabolic systems, involving tissue blood flow and circulatory vasoreactivity. The aim of this study was to investigate the effects of the oral smokeless tobacco （Swedish snus （SS）） on the perception of fatigue and time to exhaustion （TTE） during moderate-intensity aerobic exercise. Methods： Fourteen healthy non-tobacco male users were recruited for a double-blind, controlled crossover design （SS vs. snus placebo （SP））. Subjects were tested for 3 sessions： experimental session 1 （Exp 1） consisted of an incremental test to determine the maximal aerobic power out-put （Wmax）, whereas Exp2 and Exp3 consisted of exercising at 65%Wmax until exhaustion in SS or SP conditions. During Exp2 and Exp3, muscle and cerebral oxygenation was assessed by means of near-infrared spectroscopy, and the rating of perceived exertion （RPE） was recorded. Results： Comparing SS with SP tests, significant differences （p 〈 0.05） were found in the values of cerebral （-3%） and muscular tissues oxygenation （-4%） in the first 30 min of exercise. The RPE values were not significantly different between the 2 conditions （SS vs. SP）. No significant difference was found in TTE （SS： 54.25 ± 21.84 min; SP： 50.01 ± 17.03 min）. Conclusion： This study showed that muscular and cerebral oxygenation increased significantly with snus administration during an endurance exercise until exhaustion, but this did not affect fatigue perception and TTE. The results showed that snus could not be considered an ergogenic substance in non-tobacco users.2018 Published by Elsevier B.V. on behalf of Shanghai University of Sport. This is an open access article under the CC BY-NC-ND license. （http：//creativecommons.org/licenses/by-nc-nd/4.0/）.
