Cigarette smoking, CYP1A1 MspI and GSTM1 genotypes, and colorectal adenomas.
(41/2057)
Cigarette smoking has been related to increased risk of colorectal adenomas, but the underlying mechanisms are unknown. Genetic polymorphisms are known for enzymes involved in the activation of polycyclic aromatic hydrocarbons and other tobacco-related carcinogens. Polycyclic aromatic hydrocarbons are activated by cytochrome P4501A1 (CYP1A1) and detoxified by glutathione S-transferases. We investigated the relation of CYP1A1 MspI and GSTM1 genotypes to the risk of colorectal adenomas with special reference to interaction with cigarette smoking among 205 cases of colorectal adenomas and 220 controls with normal total colonoscopy in a male Japanese population. Cigarette smoking was strongly associated with increased risk of colorectal adenomas. Overall, neither the CYP1A1 MspI genotype nor the GSTM1 genotype was related to colorectal adenomas. A significant trend for increased risk of colorectal adenomas associated with smoking was observed for each of the CYP1A1 MspI genotypes, and the increasing trends did not differ by MspI genotype. The positive association between smoking and colorectal adenomas did not vary much with GSTM1 genotypes. Among former and current smokers, adenoma risk did not differ according to the combination of CYP1A1 MspI and GSTM1 genotypes. CYP1A1 MspI and GSTM1 genotypes do not seem to modify the risk of colorectal adenomas associated with cigarette smoking. (+info)
Accuracy of detection of colorectal neoplasia using an immunochemical occult blood test in symptomatic referred patients: comparison of retrospective and prospective studies.
(42/2057)
OBJECTIVE: In this study the sensitivity and specificity of immunochemical tests for colorectal neoplasia were evaluated in retrospective and prospective studies. METHODS: Four types of fecal blood tests--a chemical test (Hemoccult II) and three different immunochemical tests including a test which detects hemoglobin and transferrin- were performed in the retrospective study. In the prospective study the test for hemoglobin and transferrin was used for all patients that underwent total colonoscopy. PATIENTS: One hundred seven patients with colorectal neoplasia, 57 with gastroduodenal bleeding, and 62 with normal digestive tracts were examined retrospectively. One thousand two hundred and ninety-eight nonspecifically symptomatic patients whose endoscopic examination was negative for hemorrhagic lesions in the upper digestive tract were examined prospectively. RESULTS: In the retrospective study, sensitivities for the detection of colorectal cancers and adenomas with diameters > or =10 mm using the tests which detect hemoglobin and transferrin were 98% and 89%, respectively. These were the highest sensitivity among the four tests. The specificity of this test was 97%, which was higher than that of the Hemoccult II test. In the prospective study, the sensitivities of the tests for hemoglobin and transferrin for the detection of colorectal cancers and adenomas with diameters > or =10 mm were 79% and 33%, respectively. The specificity was 95%. CONCLUSIONS: The test for hemoglobin and transferrin showed the highest sensitivity and specificity for colorectal neoplasia in the retrospective study. The sensitivity and specificity of this test were not so high in the prospective study, but they may be clinically applicable in the evaluation of patients with various nonspecific symptoms. (+info)
Common anxieties of patients undergoing oesophago-gastro-duodenoscopy, colonoscopy and endoscopic retrograde cholangio-pancreatography.
(43/2057)
AIMS & METHODS: To investigate the anxieties of patients undergoing oesophago-gastro-duodenoscopy (OGD), colonoscopy and endoscopic retrograde cholangio-pancreatography (ERCP) in relation to their demographic features, their knowledge and understanding of the procedure, its indication, and their doctors' explanation. A standard questionnaire was filled in consecutively for 280 OGD patients, 64 colonoscopy patients and 50 ERCP patients. RESULTS & CONCLUSIONS: Majority of the anxious patients were afraid of pain. There was no difference between the "fearless" and "fearful" groups in terms of source of referral and inpatient/outpatient status. However for all 3 procedures, anxious patients were significantly younger by a mean of 10 years. Females, better educated and OGD patients undergoing the procedure for the first time were more anxious but this difference was not seen with the more complex colonoscopy and ERCP. The more sophisticated ERCP seemed to instill greater anxiety amongst Malay patients. Doctors were significantly more likely to explain the indication for OGD and colonoscopy than how it would be done. This discrepancy was not seen with ERCP where the endoscopists tend to adopt a more personal approach. Most patients prefer to be sedated. (+info)
Diminished gene expression of ileal apical sodium bile acid transporter explains impaired absorption of bile acid in patients with hypertriglyceridemia.
(44/2057)
Patients with type IV hyperlipoproteinemia, particularly those with familial hypertriglyceridemia (FHT), have impaired absorption of bile acid, a defect that may contribute to the hypertriglyceridemia ( J. Lipid Res. 1995. 36: 96;-107). To determine whether this absorption defect is a result of abnormal expression of the ileal apical sodium bile acid transporter (ASBT) gene, we biopsied the terminal ileum at colonoscopy in 28 subjects, 13 with hypertriglyceridemia and 15 control subjects. Of the 13 hypertriglyceridemic subjects, 10 had lipid profiles compatible with FHT (elevated very low density lipoprotein [VLDL] triglycerides with normal LDL cholesterol). ASBT mRNA levels were measured in these biopsies by RNase protection assay, using glyceraldehyde dehydrogenase mRNA as a reference. ASBT protein was quantitated by Western blotting with an antibody to the carboxy-terminal 20 amino acids of the protein. The mean +/- SEM ASBT mRNA level in the control group was 205.7 +/- 19.9 (arbitrary units) compared with 138. 7 +/- 19.1 for all 13 hypertriglyceridemics (P = 0.03) and 141.7 +/- 20.8 in the 10 FHT patients (P = 0.05). Commensurate with these mRNA levels, the mean ASBT protein level in the control group was 126.2 +/- 22.6 versus 58.8 +/- 13.8 in hypertriglyceridemics (P = 0.02) and 61.8 +/- 15.2 in the FHT patients (P = 0.05). We conclude that impaired absorption of bile acid in type IV hypertriglyceridemia results from diminished expression of the ASBT gene in terminal ileum. (+info)
Comparison of tests for fecal lactoferrin and fecal occult blood for colorectal diseases: a prospective pilot study.
(45/2057)
OBJECTIVE: This prospective pilot study was conducted to compare the usefulness of measuring fecal lactoferrin (Lf) to that of fecal occult blood (FOB) test for detection of colorectal diseases. PATIENTS AND METHODS: The subjects were 351 patients who underwent colonoscopy. A fecal sample was obtained on the day before colonoscopy. Fecal Lf was measured by enzyme-linked immunosorbent assay. The FOB test was performed by combined assay (latex agglutination) of hemoglobin and transferrin. RESULTS: The specificities of the fecal Lf and FOB tests were the same (88.7%). For patients with colorectal cancer (13), colorectal polyp (69), ulcerative colitis (18), Crohn's disease (13), non-specific colitis (8), internal hemorrhoids (60), colon diverticulum (27), and miscellaneous diseases of the colon (10), the rates of positivity for fecal Lf were 7/13, 14/69, 12/18, 7/13, 4/8, 22/60, 8/27, and 6/10, respectively. The corresponding rates for FOB were 8/13, 12/69, 11/18, 4/13, 4/8, 9/60, 2/27, and 1/10. For patients with internal hemorrhoids, the rate of positivity for fecal Lf was significantly higher than that for FOB. In other disease groups, there was no significant difference in the rate of positivity between fecal Lf and FOB. CONCLUSION: These findings suggest that measurement of fecal Lf is as useful as FOB in detecting colorectal diseases. (+info)
Biomarkers of human colonic cell growth are influenced differently by a history of colonic neoplasia and the consumption of acarbose.
(46/2057)
The nutritional effects of butyrate on the colonic mucosa and studies of transformed cells suggest that butyrate has anti-colon cancer effects. If butyrate has antineoplastic effects, mucosal growth contrasts between normal subjects and those with a history of colonic neoplasia would parallel changes in growth characteristics caused by butyrate in a colon neoplasia population. To test this hypothesis, rectal biopsies from a survey of colonoscopy patients (n = 50) with and without a history of colonic neoplasia (controls) were compared. Similarly, rectal biopsies were compared from subjects (n = 44) with a colon neoplasia history in an acarbose-placebo crossover trial. Control subjects in the colonoscopy survey had higher bromodeoxyuridine (BrdU) uptake than subjects with a history of neoplasia (P = 0.05). The control subjects also had a higher correlation of BrdU and Ki-67 labeling (P = 0.003). Both findings were paralleled by acarbose use. Acarbose augmented BrdU uptake (P = 0.0001) and improved the correlation of BrdU and Ki-67 labeling (P = 0.013). Acarbose also augmented fecal butyrate (P = 0.0001), which was positively correlated with Ki-67 labeling (P = 0.003). p52 antigen had an earlier pattern of crypt distribution in subjects with a history of colon neoplasia but was not affected by acarbose use. Lewis-Y antigen was expressed earlier in the crypt with acarbose but had similar expression in the colonoscopy survey groups. The use of acarbose to enhance fecal butyrate concentration produced mucosal changes paralleling the findings in control subjects as opposed to those with neoplasia, supporting the concept of an antineoplastic role for butyrate. (+info)
Screening intention and practice among first-degree relatives of colorectal cancer patients in southern Israel.
(47/2057)
BACKGROUND: First-degree relatives of colorectal cancer patients are the largest groups of individuals at increased risk for colorectal cancer. OBJECTIVE: To assess the knowledge, attitudes and behavior to disease prevention and colorectal cancer screening among first-degree relatives of colon cancer patients. METHODS: A descriptive, point-prevalence epidemiological study was conducted among 215 first-degree relatives of survivors of colorectal cancer in the southern (Negev) region of Israel. Variables included perceived health status, knowledge about cancer screening, compliance rates with colorectal cancer screening, and interest in participation in early detection programs in the future. RESULTS: The mean age of the respondents was 47.9 +/- 11.2 years, and 54% were males. Only 58 (27%) remembered having been encouraged to undergo an early detection test. In the previous year only 15% underwent fecal occult blood tests, while 9% had a barium enema and 14% an endoscopic examination of the colon by sigmoidoscopy or colonoscopy. A total of 49% of the asymptomatic respondents were unaware of recommendations for screening, and only 38.3% expressed any interest in participating in early detection programs in the future. Only 19% of respondents over the age of 50 and 8% of respondents over age 60 were interested in participating compared with 49% under the age of 50 (P < 0.0001). CONCLUSION: A minority of first-degree relatives of colorectal cancer patients reported having been counseled to undergo screening, although most had seen their family physician in the previous 3 years. Primary care physicians should be more active in informing at-risk patients and encouraging them to undergo periodic screening. (+info)
A prospective single centre study comparing computed tomography pneumocolon against colonoscopy in the detection of colorectal neoplasms.
(48/2057)
BACKGROUND AND AIMS: To determine the sensitivity and specificity of computed tomography (CT) pneumocolon in the detection of colorectal neoplasms. METHODS: A total of 201 consecutive patients with colorectal symptoms or requiring surveillance for colorectal neoplasms underwent both conventional colonoscopy and CT pneumocolon. RESULTS: On conventional colonoscopy 13 invasive colorectal carcinomas were detected in 13 patients, and 118 polyps in 63 patients (14 polyps were > or =1 cm in diameter, 25 were 6-9 mm, and 79 were < or =5 mm). CT pneumocolon detected all 13 cancers, two false positive cancers, but only 20 polyps (seven were > or =1 cm). This resulted in a sensitivity of 100% (95% confidence interval (CI) 87-100%) and specificity of 99% (95% CI 97-100%) for detection of invasive carcinoma, and a sensitivity of 73% (95% CI 56-90%) and specificity of 94% (95% CI 91-98%) for detection of invasive carcinoma and/or > or =1 cm polyps. CT pneumocolon also identified invasive carcinoma not seen at colonoscopy because of incomplete examination in three patients, and detected metastases in six colorectal carcinoma patients and extracolonic carcinoma in a further seven patients. CONCLUSIONS: CT pneumocolon had a high sensitivity and specificity for detection of invasive colorectal carcinoma but not colorectal polyps. CT pneumocolon may be suitable for initial investigation of patients with symptoms of colorectal malignancy. (+info)