Stomach carcinoma is still the leading cause of cancer death in China and the second one in the world. Its possible causes include: A) chemical factors such as intragastric formation of N-nitroso compounds (NOC) and h...Stomach carcinoma is still the leading cause of cancer death in China and the second one in the world. Its possible causes include: A) chemical factors such as intragastric formation of N-nitroso compounds (NOC) and high salt intake; B ) biological factors such as infection of Helicobacter pylori and biotoxins intake; and C ) nutritional factors such as deficiency of vitamin C, selenium, and other antioxidants. Nitrogenous precursors of NOC, e.g., alkylamines, alkylureas, alkylguanidines, and alkylamides, occur widely in nature and potential nitrosating agents, e.g., nitrite (NO2-) and NOx (the gaseous oxides of nitrogen ) are similarly widespread. Relationship between exposure to NOC and causes of human cancer was investigated extensively ten years ago. Results indicated that the exposures of NOC might contribute to the occurrences of malignancy in the upper digestive tracts including stomachs. It was also observed that both high salt intake and deficiency of some micronutrients enhanced NOC-induced carcinogenicity. Recent studies show that infection of H. pylori can lead to atrophic gastritis and achlorhydria, and promote endogenous formation of NOC indirectly[1] . Much attention has been paid to stomach cancer and NOC regarding the characterization of natural N-nitrosamides in human environment in the 1990s.展开更多
AIM To explore the relationship between consumption of fish sauce, other dietary factors, living habits and the risk of gastric cancer. METHODS From May 1994 to July 1995, a population based 1∶2 case control stu...AIM To explore the relationship between consumption of fish sauce, other dietary factors, living habits and the risk of gastric cancer. METHODS From May 1994 to July 1995, a population based 1∶2 case control study was carried out in high risk areas of gastric cancer, Changle and Fuqing cities, Fujian Province. Totally 272 cases and 544 age, gender matched controls were included. Risk state analyses were made by ASRS package. RESULTS Risk state single factor analysis indicated that gastric cancer risk rose with high intake of fish sauce (OR=2 57), salted vegetables (OR=1 41), salted or fried fish and small shrimps (OR=1 57), low consumption of fresh vegetables (OR=1 95), fresh citrus fruits (OR=1 41), other fresh fruits (OR=1 31), green tea (OR=1 72), exposure to moldy foods (OR=2 32), irregular dinners (OR=5 47) and familial history of malignancy (OR=3 27). No significant relationship was observed between smoking, drinking, salt intake, use of refrigerator and gastric cancer risk. The results of risk state conditional Logistic regression showed that fish sauce, salted or dried fish and small shrimps, irregular dinners, familial history of malignancy were included in the best risk set. The summary ARs for the four factors was 75 49%. CONCLUSION High intake of fish sauce, salted foods, moldy foods, irregular dinners and familial history of malignancy were possible risk factors for gastric cancer, whereas fresh vegetables and fruits and green tea might have protective effects for gastric cancer.展开更多
AIM To study the pathogenetic effect of salted pork (SP) (special food in Zhuanghe City, a high risk area of stomach cancer in northern China) on stomach cancer, and provide scientific basis for primary prevention of...AIM To study the pathogenetic effect of salted pork (SP) (special food in Zhuanghe City, a high risk area of stomach cancer in northern China) on stomach cancer, and provide scientific basis for primary prevention of stomach cancer in this high risk area. METHODS The study consisted of three parts. The first part was to study the mutagenicity of SP. The Ames test and micro nuclei assay of V 79 cell were employed in this part. The second part was to study the effect of SP on the gastric mucosa of residents in Zhuanghe area who had consumed SP for more than 10 years and the dose effect relations between SP and pathological changes of gastric mucosa. A total of 300 cases were analysed. The third part was to study the mucosal lesions of experimental dogs by gastroscopy and mucosal biopsy. Six healthy male dogs were chosen, three were fed with SP, and the others served as control. RESULTS In this study, the results showed that the extract of SP could lead to mutation of Salmonella typhimurium TA 98 and induce the increase of micro nuclei rate (MNR) and micro nuclei cell rate (MNCR) of V 79 at a dose range of 20～80μl/ml. There were dose effect relations between SP, MNR, MNCR. Pathological changes of gastric mucosa of local residents who had consumed SP showed significant difference from those of the control group. In people who had consumed SP for 10 years, mucosal lesions including necrosis and erosion were found; in those who consumed SP for 10～20 years, hyperplasia and dysplasia were also seen besides the above lesions and those for 20～30 years, severe dysplasia and even malignant changes could be observed. SP had damaging effect on the gastric mucosa of dogs fed with SP. The mucosal lesions became more severe with increasing feeding time. CONCLUSION SP is a strong mutagen and long term exposure to SP may result in repeated gastric mucosal damage and repair, and finally leading to severe dysplasia and malignancy.展开更多
文摘Stomach carcinoma is still the leading cause of cancer death in China and the second one in the world. Its possible causes include: A) chemical factors such as intragastric formation of N-nitroso compounds (NOC) and high salt intake; B ) biological factors such as infection of Helicobacter pylori and biotoxins intake; and C ) nutritional factors such as deficiency of vitamin C, selenium, and other antioxidants. Nitrogenous precursors of NOC, e.g., alkylamines, alkylureas, alkylguanidines, and alkylamides, occur widely in nature and potential nitrosating agents, e.g., nitrite (NO2-) and NOx (the gaseous oxides of nitrogen ) are similarly widespread. Relationship between exposure to NOC and causes of human cancer was investigated extensively ten years ago. Results indicated that the exposures of NOC might contribute to the occurrences of malignancy in the upper digestive tracts including stomachs. It was also observed that both high salt intake and deficiency of some micronutrients enhanced NOC-induced carcinogenicity. Recent studies show that infection of H. pylori can lead to atrophic gastritis and achlorhydria, and promote endogenous formation of NOC indirectly[1] . Much attention has been paid to stomach cancer and NOC regarding the characterization of natural N-nitrosamides in human environment in the 1990s.
文摘AIM To explore the relationship between consumption of fish sauce, other dietary factors, living habits and the risk of gastric cancer. METHODS From May 1994 to July 1995, a population based 1∶2 case control study was carried out in high risk areas of gastric cancer, Changle and Fuqing cities, Fujian Province. Totally 272 cases and 544 age, gender matched controls were included. Risk state analyses were made by ASRS package. RESULTS Risk state single factor analysis indicated that gastric cancer risk rose with high intake of fish sauce (OR=2 57), salted vegetables (OR=1 41), salted or fried fish and small shrimps (OR=1 57), low consumption of fresh vegetables (OR=1 95), fresh citrus fruits (OR=1 41), other fresh fruits (OR=1 31), green tea (OR=1 72), exposure to moldy foods (OR=2 32), irregular dinners (OR=5 47) and familial history of malignancy (OR=3 27). No significant relationship was observed between smoking, drinking, salt intake, use of refrigerator and gastric cancer risk. The results of risk state conditional Logistic regression showed that fish sauce, salted or dried fish and small shrimps, irregular dinners, familial history of malignancy were included in the best risk set. The summary ARs for the four factors was 75 49%. CONCLUSION High intake of fish sauce, salted foods, moldy foods, irregular dinners and familial history of malignancy were possible risk factors for gastric cancer, whereas fresh vegetables and fruits and green tea might have protective effects for gastric cancer.
文摘AIM To study the pathogenetic effect of salted pork (SP) (special food in Zhuanghe City, a high risk area of stomach cancer in northern China) on stomach cancer, and provide scientific basis for primary prevention of stomach cancer in this high risk area. METHODS The study consisted of three parts. The first part was to study the mutagenicity of SP. The Ames test and micro nuclei assay of V 79 cell were employed in this part. The second part was to study the effect of SP on the gastric mucosa of residents in Zhuanghe area who had consumed SP for more than 10 years and the dose effect relations between SP and pathological changes of gastric mucosa. A total of 300 cases were analysed. The third part was to study the mucosal lesions of experimental dogs by gastroscopy and mucosal biopsy. Six healthy male dogs were chosen, three were fed with SP, and the others served as control. RESULTS In this study, the results showed that the extract of SP could lead to mutation of Salmonella typhimurium TA 98 and induce the increase of micro nuclei rate (MNR) and micro nuclei cell rate (MNCR) of V 79 at a dose range of 20～80μl/ml. There were dose effect relations between SP, MNR, MNCR. Pathological changes of gastric mucosa of local residents who had consumed SP showed significant difference from those of the control group. In people who had consumed SP for 10 years, mucosal lesions including necrosis and erosion were found; in those who consumed SP for 10～20 years, hyperplasia and dysplasia were also seen besides the above lesions and those for 20～30 years, severe dysplasia and even malignant changes could be observed. SP had damaging effect on the gastric mucosa of dogs fed with SP. The mucosal lesions became more severe with increasing feeding time. CONCLUSION SP is a strong mutagen and long term exposure to SP may result in repeated gastric mucosal damage and repair, and finally leading to severe dysplasia and malignancy.
