Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0699790 (colon cancer)
 28,837 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The bacterial enzymes beta-glucuronidase, azoreductase, and nitroreductase, all implicated in the etiology of colon cancer, were measured in the fecal microflora of rats and humans. The effect of a high-beef diet and advanced age on the activities of these microbial enzymes were determined in the rat. Rats shifted from a grain to a meat diet showed a 1.5- to 2.5-fold increase in activity of all three fecal enzymes. Animals over 20 months of age, consuming a meat diet, showed a further increase in fecal beta-glucuronidase activity, while the levels of all three microbial enzymes increased in old rats fed a grain diet. Fecal microbial enzyme activities were also measured in humans eating a diet supplemented with bran or wheat germ. Humans receiving fiber supplements consisting of 30 g of bran or wheat germ added to their customary diets did not show significant changes in fecal enzyme activity.
 ...
PMID:Influence of diet and age on fecal bacterial enzymes. 10 Oct 73

Feces collected in Kuopio, Finland, a low-risk population for colon cancer, and in the New York metropolitan area, a high-risk population for colon cancer, were compared. The dietary intake of fat and protein were the same in the two populations, but the sources of fat were different, a greater portion coming from meat in New York, and from dairy products in Kuopio. The daily stool output was higher in Kuopio due to the high intake of cereal products rich in fiber. The concentration of fecal secondary bile acids and the bacterial beta-glucuronidase activity were lower in Kuopio, but the daily output of these constituents was the same in the two groups. The daily fecal excretion of neutral sterols was higher in Kuopio than in New York. Our data suggest that the greater fecal bulk in Kuopio may dilute tumorigenic compounds which come in direct contact with the colon mucosa.
 ...
PMID:Fecal constituents of a high-risk North American and a low-risk Finnish population for the development of large bowel cancer. 64 62

The dietary pattern and fecal constituents of two populations with distinct risk for the development of colon cancer, a high-risk population in New York Metropolitan area and a low-risk population in rural Kuopio, were studied. The average daily intake of dietary fat and protein was the same in the two groups, but the sources of fat were different, a greater portion coming from dairy products in rural Kuopio and from meat in the New York Metropolitan area. Not only the frequency of bowel movements was higher, but also the daily total stool output as well as the fecal fiber excretion were greater in Kuopio compared with New York due to high dietary intake in rural Kuopio of cereal products rich in fiber. The concentration of fecal secondary bile acids and bacterial beta-glucuronidase activity was lower in rural Kuopio, but the total daily excretion of these constituents was the same in two populations. The daily fecal excretion of bacterial nuclear dehydrogenase activity and of neutral sterols was higher in rural Kuopio, and the concentration of these constituents was the same in the two groups. The high daily excretion of cholesterol metabolites in Kuopio might be due to high dietary intake of dairy products. The data suggest that one of the factors contributing to the low-risk of large bowel cancer in Finland, in spite of high dietary intake of fat, appears to be the fact that a high dietary fiber leads to an increase in stool bulk, thus diluting bile acids, which have promoting activity.
 ...
PMID:Metabolic epidemiology of large bowel cancer: fecal bulk and constituents of high-risk North American and low-risk Finnish population. 72 77

Serum enzymes have not proved useful in evaluation of patients with early colon cancer, but certain enzymes such as transpeptidase, phosphohexone isosomerase, or 5'-nucleotidase have been of assistance in following the course of the disease, particularly in patients with metastatic spread to the liver. Attempts have been made to improve the utility of enzyme analysis in colon cancer by examination of enzyme patterns in colon biopsy specimens, feces, and colon washings. These studies, which will be summarized, are of importance in the possible development of diagnostic tools and as probes in the understanding of the etiology of colon cancer. The technical problems in carrying out these assays in humans, as well as the significance of the activity of aryl sulfatase, beta-glucuronidase, beta-glucosidase, lactic dehydrogenase, glucose-6-p-osphate dehydrogenase, and other enzymes will be considered.
 ...
PMID:Enzymes in colon cancer. General information. 76 57

Because of the potential significance of secondary bile acids and cholesterol metabolites formed by the intestinal microflora in the pathogenesis of colon cancer, fecal microbial 7alpha-dehydroxylase and cholesterol dehydrogenase activities were assayed in colorectal cancer patients, patients with adenomatous polyps, asymptomatic controls, and normal controls. The mean 7alpha-dehydroxylase activity per 100 mg of dry feces per 2 hr incubation for colorectal cancer patients was significantly greater than either asymptomatic controls or normal controls. Patients with polyps had greater activity than controls, but did not differ significantly from the cancer patients or asymptomatic controls. The mean cholesterol dehydrogenase activity for colorectal cancer patients was significantly greater than controls. Patients with polyps also had greater activity than controls. No differences in the level of fecal beta-glucuronidase activity were found among the four risk groups. These data support the concept that patients with colorectal cancer are more able to convert primary bile acids and cholesterol to microbial products in colon contents than are controls. Such differences in the activity of intestinal microflora may serve as biochemical indicators that will reflect the enzymic activity of the fecal flora as well as the key intraluminal compounds in identifying populations at different risk for developing colorectal cancer.
 ...
PMID:Metabolic epidemiology of colon cancer: enzymic activity of fecal flora. 79 71

We studied the effect of diet on the activities of four enzymes found in the intestinal flora of the male F344 rat. Animals initially fed a diet with high vegetable and grain content were shifted to a diet consisting predominantly of beef. While eating the meat diet, the rats had significantly higher levels of nitroreductase, azoreductase, and beta-glucuronidase in their fecal flora when compared to levels measured during grain feeding. However, beta-glucosidase activity was significantly lower during meat feeding, which probably reflected the lack of beta-glucosidic linkages in this diet. These findings suggested that a high-beef diet, similar in composition to that consumed by humans with a relatively high risk of colon cancer, is associated with elevated levels of specific enzymes in the colon microflora. These enzymes have been implicated in the conversion of procarcinogens into carcinogens.
 ...
PMID:The relationship between diet and rat fecal bacterial enzymes implicated in colon cancer. 100 18

Because of the potential significance of colonic bacteria and secondary bile acids in the pathogenesis of colon cancer, the present study investigated the effect of different types of dietary fiber on fecal bacterial enzymes, namely, beta-glucuronidase, 7 alpha-dehydroxylase, nitroreductase, and azoreductase, and on bile acids and neutral sterols in premenopausal women. The subjects consumed 13-15 g of wheat, oat, or corn bran daily for 8 weeks in addition to their normal diet. Stools collected during the normal and fiber diet periods were analyzed for the above constituents. Dietary wheat bran decreased the concentrations of fecal deoxycholic acid, lithocholic acid, 12-ketolithocholic acid, and neutral sterols and the activities of all bacterial enzymes. Oat bran had no effect on secondary bile acids and 7 alpha-dehydroxylase but decreased beta-glucuronidase, nitroreductase, and azoreductase levels. Dietary corn bran increased 7 alpha-dehydroxylase, lithocholic acid, and cholesterol levels and decreased deoxycholic acid coprostanol, cholestenone, nitroreductase, and azoreductase levels. These results show that the modifying effect of dietary fiber on secondary bile acids and bacterial enzymes that may play a role in carcinogenesis depends on the type of fiber consumed.
 ...
PMID:Effect of dietary fiber on colonic bacterial enzymes and bile acids in relation to colon cancer. 131 47

We studied the effect on fecal hydrolytic activities of adopting an uncooked extreme vegan diet and readopting a conventional diet. Eighteen subjects were randomly divided into test and control groups. In the test group subjects adopted the uncooked extreme vegan diet for 1 mo and then resumed a conventional diet for a second month. Controls consumed a conventional diet throughout the study. Phenol and p-cresol concentrations in serum and daily output in urine and fecal enzyme activities were measured. The activity of fecal urease significantly decreased (by 66%) as did cholylglycine hydrolase (55%), beta-glucuronidase (33%) and beta-glucosidase (40%) within 1 wk of beginning the vegan diet. The new level remained throughout the period of consuming this diet. Phenol and p-cresol concentrations in serum and daily outputs in urine significantly declined. The fecal enzyme activities returned to normal values within 2 wk of resuming the conventional diet. Concentrations of phenol and p-cresol in serum and daily output in urine had returned to normal after 1 mo of consuming the conventional diet. No changes were observed in the control group during the study. Results suggest that this uncooked extreme vegan diet causes a decrease in bacterial enzymes and certain toxic products that have been implicated in colon cancer risk.
 ...
PMID:Shifting from a conventional diet to an uncooked vegan diet reversibly alters fecal hydrolytic activities in humans. 155 66

This investigation studied the effects of a shift from a mixed diet to a lactovegetarian diet on some cancer-associated bacterial enzymes in human feces (beta-glucuronidase, beta-glucosidase, and sulphatase). Three months after the shift to the lactovegetarian diet, there was a significant decrease in beta-glucuronidase, beta-glucosidase, and sulphatase activities per gram feces wet weight (p less than 0.05, less than 0.05, and less than 0.001, respectively). In contrast, glucuronide and glucoside hydrolysis remained unchanged per gram dry weight, although sulphatase activity was still significantly lowered when expressed this way (p less than 0.01). However, the fecal excretion increased significantly (p less than 0.05). Part of the explanation for the decreased enzyme activities is obviously a dilution effect, because much of the increased fecal weight after the shift in diet was associated with a higher water content. The higher water content was probably due to a higher fiber intake (p less than 0.001). Thus, the results in this paper indicate that a change from a mixed diet to a lactovegetarian diet leads to a decrease in certain enzyme activities proposed to be risk factors for colon cancer.
 ...
PMID:Shift from a mixed diet to a lactovegetarian diet: influence on some cancer-associated intestinal bacterial enzyme activities. 212 19

The effects of dietary calcium, magnesium, and butterfat on intestinal function and flora in rats initiated with 1,2-dimethylhydrazine (DMH) were studied. Male weanling rats were assigned to six isocaloric diets that varied in their levels of calcium and magnesium (0.25% Ca with 0.05% Mg, 1.0% Ca with 0.05% Mg, or 0.625% Ca with 0.50% Mg) and butterfat (5% or 20%). One-half of the rats in each treatment were injected subcutaneously with DMH weekly for four weeks. This short-term exposure to DMH increased colonic ornithine decarboxylase (ODC) activity and the mass of cecal contents. Ingestion of the high levels of either calcium or magnesium depressed colonic ODC activity and depressed apparent absorption of organic matter, calcium, magnesium, and phosphorus. Ingestion of excess magnesium increased the mass of the cecal contents by twofold, caused hypertrophy of cecal walls, and increased the total amount of protein and total nitroreductase and beta-glucuronidase activity in the ceca of rats. Ingestion of supplemental calcium had less dramatic effects and increased the mass of cecal contents by only 28% and decreased the total amount of protein in the ceca. On the basis of their different effects on cecal microflora, magnesium appears to have less potential than does calcium as a protective agent against colon cancer.
 ...
PMID:Changes in intestinal function of rats initiated with DMH and fed varying levels of butterfat, calcium, and magnesium. 230 74


1 2 3 4 5 Next >>