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

The periodic acid-thionin Schiff/potassium hydroxide/periodic acid-Schiff (PAT/KOH/PAS) procedure has been used to investigate the histochemical staining characteristics of the mucins found in adenocarcinoma and villous lesions of the large intestine. The 46 blocks examined represented 58 lesions from 37 patients, all of whom had had resections for carcinoma of the colon. tin sharp contrast to normal colon, none of the adenocarcinomas stained red with the PAT/KOH/PAS. With two exceptions the poorly and moderately differentiated adenocarcinomas stained blue, whereas of the well differentiated lesions half were blue and half purple. The malignant villous lesions demonstrated the same trends, although a larger percentage were purple. None of the benign lesions stained blue. It is suggested that malignancy in the colon is accompanied by an increase in blue staining in the PAT/KOH/PAS technique and that such staining may be of value in the interpretation of highly atypical adenoma where it might identify the onset of malignancy. This change in staining indicates a distinct alteration in the chemistry of the mucins which we interpret as a reduction in the degree of side chain O-acylation of their constituent sialic acids.
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PMID:A new histochemical technique of use in the interpretation and diagnosis of adenocarcinoma and villous lesions in the large intestine. 7 51

The effect on colonic function of adding wheat fiber for 3 weeks to the metabolically-controlled diets of six healthy volunteers has been studied. Increasing dietary fiber intake from 17 to 45 g/day increased fecal weight from 79 +/- 6.6 g/day to 228 +/- 29.9 g/day and shortened mean transit time, measured by a continuous marker method, from 57.8 +/- 8.3 hr to 40.3 +/- 8.9 hr. The increase in fecal weight was largely due to water. Fiber caused a dilution of fecal marker and an increase in fecal fat, nitrogen, and calcium output. Fecal sodium, potassium, and chloride showed only small changes but volatile fatty acid output increased significantly without concentrations changing. Fecal bile acid output increased from 199 +/- 46 mg/day to 279 +/- 46 mg/day. These changes are discussed in light of current views of the role of dietary fiber in protecting against colon cancer.
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PMID:Changes in fecal composition and colonic function due to cereal fiber. 99 55

Estramustine (EM), a complex between estradiol-17 beta and nornitrogen mustard, is commonly used in the treatment of prostatic cancer. The exact mechanism of action is unknown but has previously been considered to be mediated through non-DNA targets, specifically with the mitotic spindle, and to be related to the intact EM complex. In the present study, using different cell-systems (monocyte phagocytosis transformed fibroblasts, colon cancer cells), the EM cytotoxicity was also found to involve direct interaxtion with DNA and cell membranes. The interaction with DNA was shown by a DNA precipitation assay using 3H- and 14C- thymidine, and the cell membrane damage by using 86Rb- accumulation as a sensitive marker for active potassium uptake. EM effects in the fibroblasts were inhibited by various metal chelators and radical scavengers. Involvement of free oxygen radicals was further indicated in a cell-free system with an oxygen electrode. The EM inhibition of monocyte phagocytosis was related to the engulfment, and was not at all influenced by radical scavengers. In contrast to EM, neither of its components alone, or together, affected monocyte engulfment. Finally, it was shown that the colon cancer cell-line HT-29 was resistant to both of the two suggested and separate mechanisms for EM toxicity: an interaction with the microtubuli system by the intact EM complex and a more unspecific action mediated by free-oxygen radicals.
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PMID:The effect of estramustine on microtubuli is different from the direct action via oxygen radicals on DNA and cell membrane. 234 5

In a large, comprehensive, population-based case-control study of colorectal cancer (The Melbourne Colorectal Cancer Study), a high intake of sodium was shown to be a statistically significant risk factor for rectal cancer in males (RR = 1.72, p = 0.01) and was close to statistical significance in females (RR = 1.58, p = 0.06). This was independent of previously described dietary risk factors and also independent of the previously described beer risk. A high intake of potassium was protective for both males and females, but this effect disappeared after adjustment was made for the previously described dietary risk factors. A high ratio of dietary potassium to sodium was a statistically significant protective factor in females for both colon and rectal cancer, and the significance of this effect was reduced after adjustment was made for the previously described dietary risk factor (RR for colon cancer = 0.70, p = 0.08; RR for rectal cancer = 0.67, p = 0.08). So far, no biological explanations are available for these associations, and while they are of obvious etiologic interest, they should be interpreted with caution.
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PMID:Dietary sodium and potassium intake and colorectal cancer risk. 260 40

A 72-year-old man with Wolff-Parkinson-White syndrome and sick sinus syndrome had colon cancer, suggesting that the conduction of the Kent bundle depends on the serum potassium level. Because of severe diarrhea or furosemide administration, the serum potassium level in this patient was sometimes low. When it was less than 3.0 mEq/l delta wave or re-entrant tachycardia via the Kent bundle occurred. These were suppressed by the administration of potassium. On the other hand, when the serum potassium level was normal or high, neither effect was noted, and electrophysiological studies, done when the level was 3.2 mEq/l, showed no evidence of conduction by the accessory pathway. This suggests that conduction through the Kent bundle depends on the serum potassium level.
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PMID:A case of Wolff-Parkinson-White syndrome: conduction through the Kent bundle seems to depend on the serum potassium level. 404 52

A population-based case-control study including 726 patients with colon cancer, 575 with rectum cancer, and 1400 population controls matched on age (+/- 5 yrs.) and sex was carried out to evaluate the association of ten inorganic elements, including potassium, sodium, calcium, magnesium, iron, manganese, zinc, copper, phosphorus and selenium, and other dietary factors with colorectal cancer. Single variable analysis adjusted for age and sex showed most of the ten elements, except sodium and selenium, may reduce the risk of the development of colorectal cancer. Correlation analysis indicated these eight elements correlated closely to the "vegetable factors", e.g., dietary fibre, and so on, since the major sources (about 80%) of these elements were from vegetables. Multi-variable logistic regression analysis showed nine elements (except sodium) may confound the effects of some dietary factors (such as dietary fibre and vitamin C) on the occurrence of colorectal cancer and only contribute to it. The results showed a close association between saturated fatty acid, mono-unsaturated fatty acid, dietary fibre, vitamins C and E, and colorectal cancer.
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PMID:[Relationship between colorectal cancer and ten inorganic elements]. 813 59

D-Glucaric acid (GA) is a nontoxic, natural compound. One of its derivatives is the potent beta-glucuronidase inhibitor D-glucaro-1,4-lactone (1,4-GL). The goal of this study was to demonstrate the in vivo formation of 1,4-GL from a D-glucarate salt and determine its metabolism, uptake by selected organs, and excretion following oral administration of potassium hydrogen D-[14C]glucarate to male and female Sprague-Dawley rats. 1,4-GL increases detoxification of carcinogens and tumor promoters/progressors by inhibiting beta-glucuronidase and preventing hydrolysis of their glucuronides. 1,4-GL and its precursors, such as potassium hydrogen D-glucarate and calcium D-glucarate, may exert their anticancer action, in part, through alterations in steroidogenesis accompanied by changes in the hormonal environment and the proliferative status of the target organ. Thus, GA derivatives may be useful as new or adjuvant cancer preventive and therapeutic agents. In our study, 1,4-GL was found to be formed from the D-glucarate salt in the stomach of rats. It was apparently absorbed from the gastrointestinal tract, transported with the blood to different internal organs, and excreted in the urine and to a lesser extent in bile. There were no significant differences in the metabolism of PHG between male and female rats. Thus, formation of 1,4-GL from D-glucaric acid derivatives may be prerequisite for their inhibition of chemical carcinogenesis in rodents and prevention of breast, prostate, and colon cancer in humans.
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PMID:Metabolism, uptake, and excretion of a D-glucaric acid salt and its potential use in cancer prevention. 910 Oct 79

We assessed the effects of 41 potential chemopreventive agents in the F344 rat using the inhibition of carcinogen-induced aberrant crypt foci (ACF) in the colon as the measure of efficacy. ACF were induced by the carcinogen azoxymethane in F344 rats by two sequential weekly injections at a dose of 15 mg/kg. Two weeks after the last azoxymethane injection, animals were evaluated for the number of aberrant crypts detected in methylene blue-stained whole mounts of rat colon. The 41 agents were derived from a priority listing that was based on reports of chemopreventive activity in the literature and/or efficacy data from in vitro models of carcinogenesis. The list of agents included representative examples of phytochemicals, vitamins, minerals, inhibitors of proliferation, inducers of Phase 1 and Phase 2 metabolism systems, nonsteroidal anti-inflammatory agents, and differentiation agents. Eighteen agents were positive in the assay, significantly reducing the incidence of ACF at least in one of two doses tested. As a chemical class, the nonsteroidal anti-inflammatory drugs, which included ibuprofen, ketoprofen, piroxicam, and indomethacin, were most active; other less potent agents were arginine, butylated hydroxyanisole, curcumin, diallyl sulfide, difluoromethylornithine, 18 beta-glycyrrhetinic acid, indole-3-carbinol, oltipraz, purpurin, rutin, and the sodium salts of butyrate, selenite, and thiosulfate. Twenty-three agents did not inhibit ACF; included among these were several agents that promoted the development of ACF at one or both doses tested: benzyl isothiocyanate,calcium glucarate, catechin, dihydroepiandosterone, fluocinolone acetonide,folic acid, levamisole, 2-mercaptoethanesulfonic acid, nordihydroguiaretic acid, potassium glucarate, propyl gallate, beta-sitosterol, sodium cromolyn, sodium molybdate, and sulfasalazine. The aberrant crypt assay demonstrates reasonable specificity and sensitivity in predicting which agents are likely to prevent colon cancer.
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PMID:Aberrant crypts as a biomarker for colon cancer: evaluation of potential chemopreventive agents in the rat. 916 1

The purpose of this study was to elucidate the mechanism of 201Thallium-chloride (201Tl) uptake in tumor cells and its possible relationship to potassium channels. The subcellular biodistribution of 201Tl in tumor cells was examined in colon cancer (LS180) bearing nude mice using sequential centrifugation. The involvement of potassium channels in 201Tl uptake in tumor cells was examined by uptake inhibition with potassium channel blockers (ouabain, bumetanide, and glibenclamide) in cultured leukemia cells (K562). Greater than 90% of 201Tl was found in the soluble cytoplasmic fraction. 201Tl uptake was inhibited by ouabain and bumetanide but not by glibenclamide. These data demonstrate that 201Tl uptake in tumor cells is mediated by the Na(+)-K+ ATPase and the Na(+)-K(+)-2Cl- cotransporter with 201Tl acting as a potassium analogue.
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PMID:Mechanism of 201thallium-chloride uptake in tumor cells and its relationship to potassium channels. 947 Oct 98

The aim of this study was to establish an autochthonous colon cancer model in the rat as an in vivo secondary screen for the general evaluation of new anticancer agents against colorectal cancer, and also to evaluate practically the antitumor activity of 1M tegafur-0.4M 5- chloro-2,4-dihydroxypyridine-1M potassium oxonate(S-1), a new p.o. fluoropyrimidine. Thirty-two Sprague-Dawley rats received dimethlhydrazine(40 mg/kg) s.c. once weekly for 10 weeks to induce colon cancer.20 weeks after beginning the carcinogen treatment, a barium enema was performed to visualize tumors. The animals were divided into a control group and S-1 treatment group. After 5 weeks of treatment, the barium enema was repeated. The mean doubling time of 24 tumors in the control group was 19.0 + 8.4 (SD) days. Response to S-1 was judged as effective when the doubling time exceeded 35.8 days, calculated from the mean + 2SDs in the control group. The response rate of S-1 was 55%, 34% of the tumors were decreased in size after treatment. This figure was higher than that of clinically-used 5-fluorouracil(5-FU) derivatives; 5-FU;6%, Tegafur(FT):6%, 1M tegafur-4M uracil(UFT):14%, reported in our previous study. An autochthonous colon cancer model is useful to evaluate the clinical therapeutic efficacy of drugs for colorectal cancer, and S-1 is expected to have a high therapeutic effect on human colorectal cancer.
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PMID:Antitumor effect of S-1 on DMH induced colon cancer in rats. 961 78


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