Effect of environmental factors on risk of bowel cancer. ; agricultrual chemicals and colon cancer
Grant-in-Aid for General Scientific Research (C)
|Allocation Type||Single-year Grants|
|Research Institution||University of Occupational and Environmental Health|
ITOH Hedeaki UOEH,Professer, 医学部, 教授 (90038852)
HIRATA K UOEH,Assistant, 医学部, 助手 (70269059)
KURODA Y UOEH,Associate professor, 医学部, 助教授 (30131915)
|Project Period (FY)
1993 – 1994
Completed(Fiscal Year 1994)
|Budget Amount *help
¥2,100,000 (Direct Cost : ¥2,100,000)
Fiscal Year 1994 : ¥1,000,000 (Direct Cost : ¥1,000,000)
Fiscal Year 1993 : ¥1,100,000 (Direct Cost : ¥1,100,000)
|Keywords||Colon cancer / Experimental colon cancer / 1,2-Dimethyl hydrazine / Indomethacin / Epithelial cell proliferation / Herbicide / Trinitrobenzene sulfonic acid / Fibronectin / 1,2-dimethy1 hydrazine / 発癌プロモーター作用 / 2,4-Phenoxy acetic acid / Captan|
1) Experimental carcinogenesis in the rat intestine
Carcinogenesis in the rat intestine induced with 1,2-dimethylhydrazine (DMH), N-methyl-N-nitrosourea (MNU) was studied. The tumor frequently occurred in the intestinal tract extending from the duodenum to the colon in the DMH treated group. In the MNU treated group, the tumor occurred in the colon.
2) The effect of carcinogens on ornithine decarboxylase activity (ODC)
Tumor tissues in rat colon showed a high level of ODC activity compared wity the normal-appearing mucosa, and there was a correlation between tne level of ODC activity and histological grade of malignancy. ODC activity in the normal-appearing mucosa of the carcinogens-treated rat was significantly higher than that of control, and the number of tumors per rat was correlated with the level of ODC activity.
3) The effect of herbicides on the promoting activity in the intestinal carcinogenesis model of rats
3.1) 2,4-Phenoxy acetic acid (2,4-PA)
2,4-PA did not increase the incidenc
e of tumors, nor cause a increase in BrdU labeling index of normal intestinal mucosa.
Captan increased the incidence of duodenal and colon tumors (no significance). It had no influence on the histological features, but increased the incidence of cancer metastasis to the lymph nodes and liver tumors. Captan treatment did not cause a increase in BrdU labeling index of normal intestinal mucosa.
4) Regression of rectal polyps by indomethacinn in familial adenomatous polyposis
The effect of indomethacin (IND) on rectal polyps was evaluated in patients with FAP.In addition, the effect of IND on rectal mucosal proliferation was assessed by immunostain using a monoclonal antibody to Ki-67 antigen. IND treatment was effective for the control of rectal polyps in FAP patients. However, IND treatment was not associated with a reduction in rectal cell proliferation.
5) The healing process of rat chronic colitis model.
The healing process of rat chronic colitis was investigated to evaluate the role of fibronectin produced by fibroblasts in the healing tissue. Observations elucidated the role of young fibroblasts, as multipotent cells, and the fibronectin in acceleration of the healing process of this model of chronic colitis. Less
Research Output (8results)