In order to investigate the mechanisms of the anticarcinogenic effect of Chinese tea on the development of esophageal tumors in rats induced by N-nitrosomethylbenzylamine, the alkylation of DNA in various organs was s...In order to investigate the mechanisms of the anticarcinogenic effect of Chinese tea on the development of esophageal tumors in rats induced by N-nitrosomethylbenzylamine, the alkylation of DNA in various organs was studied in rats treated with 2 varieties of Chinese tea, i.e. Fujian Oolong tea and Jasmine tea. Male Wistar rats were given a single i.v. injection of N-nitroso-[methyl-14C]-benzylamine (2.5 mg/kg.body wt) after having been provided tea in drinking water and by gavage for 2-3 weeks. Control rats were provided with tap water. Three to four hours after administration of the Af-nitroso compound, the methylation of purine bases in the DNA isolated from various organs was measured by high performance liquid chromatography and liquid scintillation counting. In the tea-drinking rats, there was an appreciable reduction of O6-methylguanine formation in the esophageal DNA as well as the ratio of O6-metylguanine to N7-methylguanine, as compared to the control rats. No O6-methylguanine was detected in lung or liver DNA.展开更多
What is lacking in nutrition information, education and communication (IEC) work today is accurate knowledge about the processes which bring about beneficial nutritional behavior changes. In this paper, Nutri-action A...What is lacking in nutrition information, education and communication (IEC) work today is accurate knowledge about the processes which bring about beneficial nutritional behavior changes. In this paper, Nutri-action Analysis is proposed as a mechanism for nutrition planners to gain this knowledge and seek ways to improve the effectiveness of nutrition IEC interventions. It suggests that a more holistic and dynamic approach is necessary to conceptualize nutrition IEC and increase its effectiveness in bringing about changes in behaviors which lead to nutritional status improvement. Nutri-Action Analysis,as a research strategy, is illustrated by a three-stage procedure: (i) pre-action, (ii) action,and (iii) post-action. This process leads investigators to begin conducting a macro-analysis of nutrition IEC in general and within their specific contexts in order to understand the system and identify the best approach to be adopted for a nutrition IEC intervention in their particular context. What is discovered should then be tested in a community-based operational research study using both quantitative and qualitative data so that it is possible to subsequently conduct a synthesis focusing on process determinants展开更多
文摘In order to investigate the mechanisms of the anticarcinogenic effect of Chinese tea on the development of esophageal tumors in rats induced by N-nitrosomethylbenzylamine, the alkylation of DNA in various organs was studied in rats treated with 2 varieties of Chinese tea, i.e. Fujian Oolong tea and Jasmine tea. Male Wistar rats were given a single i.v. injection of N-nitroso-[methyl-14C]-benzylamine (2.5 mg/kg.body wt) after having been provided tea in drinking water and by gavage for 2-3 weeks. Control rats were provided with tap water. Three to four hours after administration of the Af-nitroso compound, the methylation of purine bases in the DNA isolated from various organs was measured by high performance liquid chromatography and liquid scintillation counting. In the tea-drinking rats, there was an appreciable reduction of O6-methylguanine formation in the esophageal DNA as well as the ratio of O6-metylguanine to N7-methylguanine, as compared to the control rats. No O6-methylguanine was detected in lung or liver DNA.
文摘What is lacking in nutrition information, education and communication (IEC) work today is accurate knowledge about the processes which bring about beneficial nutritional behavior changes. In this paper, Nutri-action Analysis is proposed as a mechanism for nutrition planners to gain this knowledge and seek ways to improve the effectiveness of nutrition IEC interventions. It suggests that a more holistic and dynamic approach is necessary to conceptualize nutrition IEC and increase its effectiveness in bringing about changes in behaviors which lead to nutritional status improvement. Nutri-Action Analysis,as a research strategy, is illustrated by a three-stage procedure: (i) pre-action, (ii) action,and (iii) post-action. This process leads investigators to begin conducting a macro-analysis of nutrition IEC in general and within their specific contexts in order to understand the system and identify the best approach to be adopted for a nutrition IEC intervention in their particular context. What is discovered should then be tested in a community-based operational research study using both quantitative and qualitative data so that it is possible to subsequently conduct a synthesis focusing on process determinants
