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PubMed1981

Recovery of helminths postmortem from equines. II. Helminths and larvae of gasterophilus in the gastro-intestinal tract and oestrids from the sinuses.

The tongue, pharynx, oesophagus and gums are examined for larvae of gasterophilus spp., and the nose and sinuses for oestrid larvae. The gastro-intestinal tract is divided into separate specimens-stomach, small intestine, caecum, ventral colon, dorsal colon, descending colon and rectum- and each is examined separately. Aliquots of ingesta of 1/4 by mass of the stomach and 1/10 by mass of the small intestine, caecum, ventral colon and dorsal colon are collected for microscopic examination. Each part of the wall of the caecum, ventral and dorsal colon is washed and specimens are collected for subsequent examination. The gut wall of the caecum and colon is examined macroscopically for larval stages. Ingesta in the descending colon are examined macroscopically for Gasterophilus larvae.

Animals↗
PubMed2003

Morphological properties of zero-stress state in rat large intestine during systemic EGF treatment.

Systemic treatment with epidermal growth factor (EGF) induce growth of the large intestine. The aim of this study was to investigate the morphological properties early in the course of EGF-induced large intestinal growth. The effects of systemic EGF treatment on the morphological properties at the zero-stress state along the large intestine were investigated. EGF-treated rats and control rats were allocated into group with EGF treatment for 2, 4, 7, and 14 days (N = 6 for each EGF treatment group except N = 4 for the 14-day group). The controls had saline injected (N = 3 for each group). The excised large intestine was subdivided into four segments: the ascending colon, transverse colon, descending colon, and rectum. The length and weight of each segment was measured. The zero-stress state was obtained by cutting rings of the large intestine radially, and the opening angle was measued on video images. The thickness and cross-sectional area of the mucosa and muscle layers, and the inner and outer circumference were measured. The total colon length did not increase, whereas the weight of the large intestine, muscosal thickness and mass, and inner and outer circumference increased significantly (P < 0.05). The increase was most prominent in the proximal colon after 7 days of EGF treatment. Later no further morphological changes were observed, except for a decrease in mucosal thickness in most segments and in mucosal cross-sectional area in the descending colon. In the controls and during the first week of EGF treatment, the opening angle was approximately 100 degrees. After 14 days the opening angle increased significantly in the ascending and transverse colon to approximately 172 and 135 degrees (P < 0.05). In conclusion, this study demonstrates that systemic EGF treatment caused remodeling of the morphology of the zero-stress state in the large intestine in a time-dependent manner. The growth was most pronounced in the ascending and transverse colon and involved mainly the mucosal layer.

Analysis of Variance↗
PubMed1991

Steady-state response characteristics of a pulse oximeter on equine intestine.

The steady-state response characteristics of a pulse oximeter were evaluated on intestinal segments of seven clinically normal halothane-anesthetized horses. Arterial oxygen tension greater than 200 mm of Hg, end tidal carbon dioxide from 30 to 35 mm of Hg, and systemic mean arterial pressure greater than 70 mm of Hg were maintained throughout the recording periods. Values for percentage of pulse oximeter oxygen saturation, pulsatile blood flow, and percentage of signal strength were recorded from jejunum, ileum, cecum, left ventral colon, left dorsal colon, and descending colon. Probe placement on intestinal segments was recorded as over or not over visible subserosal or transmural vessels. There was no significant difference between median values on the basis of vessel codes for pulse oximeter oxygen saturations, pulsatile flow, and signal strength. Median values recorded for pulse oximeter oxygen saturation were 93% from jejunum and ileum and 95% from cecum, left ventral colon, left dorsal colon, and descending colon; median values for pulsatile flow were 576 from jejunum, 560 from ileum, 560 from cecum, 574 from left ventral colon, 578 from left dorsal colon, and 560 from descending colon; median values for signal strength were 50% from jejunum, 67.5% from ileum, 60% from cecum, 75% from left ventral colon, 50% from left dorsal colon, and 52.5% from descending colon. Median values obtained from each anatomic location were not significantly different for pulsatile flow or signal strength. Median pulse oximetry oxygen values recorded from jejunum and ileum were significantly lower than values obtained from other intestinal segments.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1996

Distribution of myristoyl-CoA:protein N-myristoyl transferase activity in rabbit intestine.

Myristoyl-CoA:protein N-myristoyl transferase (NMT) attaches the fatty acid, myristate, to the amino-terminal glycine residue of various proteins involved in cellular regulation and/or signal transduction. We report differences in the activity and properties of NMT in New Zealand rabbit small intestine, ascending colon and descending colon. The mucosa of the small intestine, ascending colon and descending colon was assayed for NMT activity using peptides of known myristoylated proteins (pp60src and catalytic subunit of cAMP dependent protein kinase). Total NMT activity per gram tissue was 5-fold higher in the small intestine and 1.5-fold higher in the ascending colon than in the descending colon. Smooth muscle from the colon also contained low levels of NMT activity. NMT activity was 2- to 3-fold higher in the particulate fraction than in the cytosolic fraction of the mucosa in the descending colon. The apparent molecular mass of NMT in the intestine mucosa was 78 kDa.

Acyl Coenzyme A↗
PubMed1986

Neodymium-YAG laser. A new palliative tool in the treatment of colorectal cancer.

Twenty-four patients with colorectal carcinoma and one patient with a recurrent, transitional-cell, vesical tumor invading the rectum but not amenable to surgical resection underwent neodymium-YAG laser therapy. There were 16 men and nine women with an average age of 75.6 years (range, 35 to 93 years). There were 14, 6, 1, 1, and 3 tumors found in the rectum, rectosigmoid colon, transverse colon, descending colon, and ascending colon, respectively. Symptoms consisted of bleeding or partial obstruction. Twelve patients were high-risk surgical candidates, 11 patients had widespread disease, and two patients had another primary tumor not controlled by a previous surgical procedure. The tumor was eradicated in two patients. There were two complications, namely, a perforation and a rectovaginal fistula. Thirteen patients died from their disease. The remaining patients have been kept free from obstruction and bleeding.

Adenocarcinoma↗
PubMed1980

Relationship between cholecystectomy and ascending colon cancer.

A retrospective study involving 706 sample cases of large bowel cancer grouped by subsite (ascending colon, transverse colon, descending colon, sigmoid colon, ana rectum), sex, and age identified during the Third National Cancer Survey (Pittsburgh SMSA, 1969--1971) was recently completed. The basic strategy of this comparative study was to determine whether the frequency distribution patterns of both demorgraphic characteristics and environmental factors differed among persons with subsite-specific cancer of the large bowel. Based on the information provided in the hospital records there was a gradient of previous cholecystectomy history from ascending colon cancer (10.5%) to rectal cancer (2.1%) in those patient records whose only gastrointestinal surgery indicated was cholecystectomy. For patient records in which the only surgical operation was cholecystectomy, or cholecystectomy plus other gastrointestinal surgery, the gradient persisted as one moved from the right to the left subsites of the large bowel. No relationship with respect to other types of gastrointestinal surgery was observed. It is clear, however, that a bias associated with the review of hospital records can account for this relationship and, therefore, the finding may be spurious. On the other hand, there is increasing evidence of a relationship between bile acid metabolism and carcinoma of the colon. It might be considered that the right side of the colon would be most likely affected by the potential carcinogenic effect of certain bile acid metabolites.

Adult↗
PubMed1994

Age-period-cohort modelling of large-bowel-cancer incidence by anatomic sub-site and sex in Denmark.

In a previous investigation, statistical modelling was used to examine the relationship between large-bowel-cancer incidence and age, time period and birth cohort by anatomic sub-site and sex, using data from the Connecticut Tumor Registry (CTR) for the period 1950 to 1984. This analysis revealed differences in age-period-cohort patterns that suggested etiologic distinctions among sub-site groupings and between the sexes. To test the generalizability of the Connecticut findings, we have conducted a similar age-period-cohort analysis using data from the Danish Cancer Registry (DCR) for the period 1953 to 1987. Cancers of the large bowel were classified into 6 anatomic sub-sites: cecum, ascending colon, transverse colon, descending colon, sigmoid colon and rectum. Data were fitted to log-linear age-period-cohort models. If we interpret differences in age-period-cohort patterns as reflecting etiologic distinctions, the Denmark analysis, in conjunction with the Connecticut findings, was consistent with there being etiologic distinctions between cancers of the colon vs. the rectum in both males and females, between cancers of the cecum and the ascending colon vs. the remainder of the colon in females and between males vs. females for cancers of the sigmoid colon and rectum. Cancers of the cecum and the ascending colon were the most similar between males and females. Due to the ambiguities of age-period-cohort modelling, these should be considered only tentative conclusions that can be tested by analytical epidemiologic studies.

Adult↗
PubMed1995

Subsite-specific risk factors for colorectal cancer: a hospital-based case-control study in Japan.

To investigate the subsite-specific risk factors for colorectal cancer, we conducted a case-control study, using a common questionnaire which inquired about general lifestyles over the past five years (1988-92), at the Aichi Cancer Center Hospital, Nagoya, Japan. This study compared 432 patients with histopathologically diagnosed colorectal cancer (94 proximal colon [cecum, ascending colon, transverse colon]; 137 distal colon [descending colon, sigmoid colon]; 201 rectum [rectosigmoid, rectum]); and 31,782 first-visit outpatient controls who were free from cancer. In both genders, habitual smoking selectively increased the risk for rectum cancer. Soft or loose feces increased the risk for all subsites of colorectal cancer, particularly in female rectum cancer (odds ratio [OR] = 4.5). Among female dietary habits, Japanese-style foods decreased the risk for distal colon cancer, but increased the risk for proximal colon cancer. These results suggested that the risk factors for colorectal cancer differ by subsite among such a low-risk population as the Japanese. It is suggested also that 'irritable bowel' (soft or loose feces) might be associated with distal subsites of colorectal cancer, independently or combined with habitual smoking.

Adult↗
PubMed1979

Ontogeny and distribution of certain oendocrine cells in the human fetal large intestine. Histochemical and immunocytochemical studies.

In 9 fetuses, 9 to 24 weeks-old, the occurrence and relative distribution of argentaffin cells, as well as of cells immunoreactive to somatostatin (SRIF), glucagon-like polypeptide (GLI), pancreatic polypeptide (PP) and substance P (SP) were studied in five segments of the colon (appendix, cecum, ascending colon, descending colon, and rectosigmoid). For each colonic segment, data concerned with the occurrence of endocrine cells were expressed either as mean absolute numbers of specific cells per entire mucosal section, or as cell densities per mm3 of mucosa after calculation of the mucosal volume of the sections. Argentaffin, GLI, SRIF and PP immunoreactive cells are all present in relatively large numbers, scattered along the entire length of the colonic mucosa as early as the 9th-10th week of gestation, whereas substance P-containing cells occur sporadically and first appear during the 4th-17th week. Until the 20th week, with progressing embryonic development, an increase was determined in absolute numbers per section of all types of endocrine cells in all segments of the colon. This observation is clearly related to the general growth of the colonic mucosa, since cell densities per mm3 of mucosa do not greatly change or even decrease during gestation. However, it is possible that densities of argentaffin, GLI and BPP cells increase in the appendix around the 14th-17th week of gestation. Between 20th and 24th weeks, absolute numbers of cells per section remain stable or slightly increase, while cell densities tend rather to decrease in all segments. These data demonstrate that some endocrine cells are present very early in the human fetal colon, but their functional significance remains to be elucidated.

Colon↗
PubMed2001

Expression of Cdx1 and Cdx2 mRNAs and relevance of this expression to differentiation in human gastrointestinal mucosa--with special emphasis on participation in intestinal metaplasia of the human stomach.

BACKGROUND: The caudal-type homeobox genes, Cdx1 and Cdx2, are candidates for directing intestinal development, differentiation, and maintenance of the intestinal phenotype. The aims of this study were: (1) to assess the normal tissue expression patterns of Cdx1 and Cdx2 in the human gastrointestinal tract and (2) to ascertain levels in intestinal metaplasia (IM) of the stomach associated with gastritis. METHODS: Fresh human tissues were collected by surgical resection from 39 patients after informed consent had been received. RNAs were extracted from 11 distinct sites in the gastrointestinal mucosa (gastric body, gastric antrum, duodenum, jejunum, ileum, cecum, ascending colon, transverse colon, descending colon, sigmoid colon, and rectum), and Northern hybridization was performed for Cdr1 and Cdx2 mRNAs. In addition, RNAs were also extracted from normal gastric mucosa, and gastric mucosa with mild to severe IM, confirmed histopathologically. Reverse-transcriptase polymerase chain reaction (RT-PCR) was then carried out for Cdx1 and Cdx2. RESULTS: The expression of Cdx1 mRNA increased gradually from the duodenum to the distal colon, with no expression detected in the stomach. Compared with the distribution of Cdx1 mRNA in the mouse gastrointestinal tract, the expression of Cdr1 mRNA in the human gastrointestinal tract showed greater predominance in the jejunum and ileum. The expression of Cdx2 mRNA increased gradually from the duodenum to the proximal colon and decreased from the ascending colon to the rectum. Compared with the expression pattern of Cdx2 mRNA in the mouse gastrointestinal tract, the expression of Cdx2 mRNA in the human gastrointestinal tract showed greater predominance in the ileum. By RT-PCR, both Cdx1 and Cdx2 mRNAs were detected in the mild and severe types of IM. However, neither of these mRNAs was identified in normal gastric mucosa without IM. CONCLUSIONS: Cdr1 and Cdx2 mRNAs are widely present in the human intestinal and colonic mucosae, but not in the gastric mucosa, suggesting that their expression may contribute to the intestinal phenotype. The high levels of these mRNAs in IM mucosa associated with chronic atrophic gastritis point to an association with this phenotypic shift in the gastric mucosa.

Adult↗
PubMed2005

Disseminated mixed intestinal dysmotility (DMID): a new intestinal ganglion cell disorder?

We experienced two cases with disseminated HP and IND occurring with normal bowel in between (disseminated mixed intestinal dysmotility--DMID) and postulate whether it could be classified as a new intestinal motility disorder. Our cases, both boys, died at 3 and 7 months, respectively. Both had irregular stool passage, and abdominal distention with bilious vomiting since birth. On barium enema, both had rigid distal ileum and colon with narrow lumens, with dilated and atonic proximal ileum and jejunum. An ileostomy was created on days 3 and 2 of life, respectively, however, they did not function and jejunostomies were created, which also did not function well. Both boys died after repeated episodes of severe enterocolitis. In each case, three 10 cm specimens were obtained randomly from the jejunum and ileum, and two 5 cm specimens were obtained randomly from each of the ascending colon, transverse colon, descending colon, and rectum and treated with hematoxylin and eosin (H & E) staining, acetylcholine esterase (AchE) histochemistry, and protein gene product 9.5 (PGP9.5) and neural cell adhesion molecule (NCAM) immunohistochemistry for histopathologic assessment. All specimens showed a mixture of disseminated IND and HP, with normal intestine in between. There was abnormal expression of NCAM activity in the intestinal smooth muscle layers in small and large intestine. This is the first report about disseminated IND and HP occurring with normal bowel in between (DMID) and we suggest it should be classified as a new intestinal motility disorder. The present findings demonstrate that patients with DMID have a complicated abnormality of NMJ that may directly influence bowel motility and prognosis according to the severity of the abnormality.

Digestive System Abnormalities↗
PubMed2004

Magnetic resonance imaging based colonography for diagnosis and assessment of diverticulosis and diverticulitis.

BACKGROUND AND AIMS: MRI-based colonography is a new minimally invasive imaging modality to assess the colon and abdomen. This new method which is applied mainly for polyp screening could be an integrative approach for colonic diverticulitis assessment. This study evaluated the feasibility of MRI-based colonography to assess diverticulosis or diverticulitis. PATIENTS AND METHODS: Fourteen consecutive patients with clinically suspected diverticulitis were examined by MRI colonography on a 1.5-T scanner. All patients underwent abdominal CT as gold standard. N-Butyl-scopalamin was given intravenously to reduce bowel peristalsis. After rectal administration of a T1-positive enema T1- and T2-weighted acquisitions with additional intravenous contrast were obtained. A 3D FLASH sequence was acquired for virtual colonography. The results were compared with CT and biological parameters such as white blood cell count and C-reactive protein. RESULTS: Of 56 bowel segments (sigmoid colon, descending colon, transverse colon, ascending colon) in all 14 patients 54 were assessed to have good to fair image quality. Having CT as standard of reference, all sigmoid diverticula were diagnosed based on MRI. Inflammation as judged by CT was identically assessed on MRI. 3D models of the colon revealed further diverticula in the remaining colon; additionally, the 3D models gave a comprehensive image for surgical planning. CONCLUSION: In our preliminary study MRI colonography revealed the same diagnosis as CT in all patients without ionizing radiation. Additionally, 3D-rendered models and virtual colonoscopy can be performed. This comprehensive 3D models could replace presurgical planning barium enema with concurrent assessment of the residual colon.

Adult↗
PubMed2004

Prospective comparison of air-contrast barium enema and colonoscopy in patients with fecal occult blood: a pilot study.

BACKGROUND: The utility of air-contrast barium enema and colonoscopy for evaluation of the colon has been debated. Air-contrast barium enema is less expensive and invasive than colonoscopy, but it also is less sensitive and specific. Further, although air-contrast barium enema may be less painful than colonoscopy, it often is poorly tolerated by patients. Thus, this study compared the sensitivity and the specificity of air-contrast barium enema and colonoscopy for detection of colonic lesions in patients with fecal occult blood. METHODS: Over a 30-month period, patients with fecal occult blood were recruited. Patients underwent standard air-contrast barium enema, followed by colonoscopy 7 to 14 days later. Colonoscopists were blinded to the results of air-contrast barium enema until the colonoscopy was completed, after which the results were disclosed. If the findings were discrepant, colonoscopy was repeated. RESULTS: A total of 100 patients were evaluated. Nine air-contrast barium enemas were reported to be inadequate, and the cecum was not intubated at colonoscopy in two patients. In the remaining patients, 5 cancers were identified (1 each cecum, transverse colon, descending colon, sigmoid colon, and rectum) by both studies. Sixty-six polypoid lesions were identified in 30 patients. Diverticula were identified in 42 patients by air-contrast barium enema and in 18 patients by colonoscopy. Air-contrast barium enema detected 3 of 36 polypoid lesions 5 mm or less in diameter, 5 of 15 adenomas 6 to 9 mm in size, and 4 of 15 adenomas 10 mm or greater in diameter (sensitivity 8%, 33%, and 27%, respectively). After excluding patients with diverticula, air-contrast barium enema detected 3 of 7 adenomas 10 mm or greater in size. Overall, 12 polypoid lesions or filling defects were identified by air-contrast barium enema that could not be verified by colonoscopy. The specificity of air-contrast barium enema for lesions 1.0 cm or greater in size was 100%; for those 6 mm or greater, it was 97%. CONCLUSIONS: Air-contrast barium enema accurately detects colon cancer and diverticula. Its sensitivity for detection of polypoid lesions or adenomas is poor and was confounded by the presence of diverticula.

Adenomatous Polyps↗
PubMed2000

Increased mast cells in the irritable bowel syndrome.

Mast cells (MC) release potent mediators which alter enteric nerve and smooth muscle function and may play a role in the pathogenesis of the irritable bowel syndrome (IBS). The aim of this study was to determine if MC were increased in the colon of IBS patients compared to controls. Biopsy specimens were obtained from the caecum, ascending colon, descending colon and rectum of 28 patients: 14 IBS (Rome criteria); seven normal; and seven inflammatory controls. Tissue was stained immunohistochemically using a monoclonal mouse antibody for human mast cell tryptase (AA1). Tissue area occupied by tryptase-positive MC (volume density of mast cells) was quantified by image analysis. The number of plasma cells, lymphocytes, eosinophils, neutrophils and macrophages were each graded semiquantitatively (0-4) in haematoxylin and eosin stained sections. Mast cell volume density was significantly (P < 0.05) higher in IBS (0.91 +/- 0.18; CI 0.79; 1.0) than normal controls (0.55 +/- 0.14; CI 0.40; 0.69) in the caecum but not at other sites. Apart from MC, there was no evidence of increased cellular infiltrate in the IBS group. MC were significantly increased in the caecum of IBS patients compared to controls. The multiple effects of the intestinal mast cell alone, or as a participant of a persistent inflammatory response, may be fundamental to the pathogenesis of IBS.

Adult↗
PubMed2003

Colonic mucosa in patients with portal hypertension.

BACKGROUND AND AIMS: To do a histomorphometric study of vascular changes in colonic mucosa of patients with portal hypertension (PHT) and to find their association with clinical and upper and lower gastrointestinal endoscopic observations. METHODS: Full length colonoscopy was carried out in 55 patients with portal hypertension and 25 controls. Hemorrhoids, anorectal varices and colopathy were carefully looked for and recorded. Two biopsies each were taken from the caecum, ascending colon, transverse colon, descending colon and rectum. Sections from all the five sites were examined for histopathological changes with special reference to changes in mucosal capillaries. Morphometric assessment of the diameter of the capillary and thickness of the capillary wall was performed. These histomorphometric changes were correlated with clinical parameters and findings of upper and lower gastrointestinal endoscopic findings. RESULTS: Dilated and congested capillaries as well as capillaries with irregular thickening of the wall were seen in a significantly higher number of sections from patients than controls in biopsies from all the five sites from caecum to rectum. On morphometry, the diameter of the capillaries and the thickness of the capillary wall in biopsies from all the five sites in patients was significantly higher than that in the control group. Apart from vascular changes, edema and inflammatory infiltrate in lamina propria were the other significant histological features noted. No significant association between clinical and endoscopic features and histomorphometric assessment was found. CONCLUSION: Dilated tortuous mucosal capillaries with irregular thickening of wall, edema of lamina propria and mild chronic inflammatory infiltrate are the major histopathological changes seen in colonic biopsies of patients with PHT, showing that PHT produces changes in the colonic mucosa similar to those seen in the mucosa of upper GI tract. However, the histological changes had no correlation with the clinical or endoscopic findings except that the thickness of the capillary wall was higher in patients who had undergone endoscopic sclerotherapy as opposed to those who had not received sclerotherapy.

Adolescent↗
PubMed2005

Incomplete conventional colonoscopy: magnetic resonance colonography in the evaluation of the proximal colon.

BACKGROUND AND STUDY AIMS: The purpose of this study was to evaluate dark-lumen magnetic resonance (MR) colonography prospectively in patients with incomplete conventional colonoscopy. PATIENTS AND METHODS: Thirty-two patients with incomplete conventional colonoscopy underwent same-day dark-lumen MR colonography on the basis of a standard protocol. The depiction of colorectal diseases was assessed in the following colon segments: cecum, ascending colon, transverse colon, descending colon, sigmoid colon, and rectum. The reasons for incomplete colonoscopy included high-grade stenosis in 26 patients (four with occlusive cancer, 12 with fibrotic stenosis based on recurrent sigmoid diverticulitis, eight with Crohn's-induced stenosis, and two with nonsteroidal anti-inflammatory drug colonopathy), extreme patient intolerance in one patient, and technical challenges associated with an elongated colon in five patients. The results of MR colonography were compared with the findings of the initial conventional colonoscopy, the histopathological outcome, and follow-up colonoscopy when possible. RESULTS: All high-grade stenoses were confirmed on MR colonographic data sets. Of the 26 patients with high-grade stenosis, 19 underwent surgery with histopathological confirmation of the initial diagnosis. Follow-up colonoscopy was carried out in 14 patients with surgically treated high-grade stenosis. In six of these 14 patients, nine polyps identified at the initial MR colonography were confirmed and removed during a postoperative conventional colonoscopy. Two polyps (5 mm and 8 mm in diameter) identified on postoperative conventional colonoscopy had not been seen preoperatively at MR colonography. One polyp seen on MR colonography was not identified in the follow-up colonoscopy. CONCLUSION: Dark-lumen MR colonography is a feasible and useful method of evaluating the entire colon in patients with incomplete conventional colonoscopy.

Adult↗
PubMed1984

[Colorectal angiodysplasias (vascular ectasias). Endoscopic morphology, localization and incidence].

In a prospective study, angiodysplasias were looked for in 824 patients during total coloscopy. Such angiodysplasias were discovered in 30 patients (3.6%). The endoscopic morphology varied, most of the angiodysplasias being smaller than 5 mm (23 patients), with a homogeneous structure in 19, spider-like extensions in only 11 patients. In 13 patients there were multiple angiodysplasias. Two or more segments of the colon were affected in 7 patients. Site of lesions was as follows: in 19 patients in the caecum and/or ascending colon; descending colon, sigmoid and/or rectum in 16; transverse colon in 3 patients. Histological confirmation was obtained in 9 of 20 patients who had a biopsy. Right-sided colectomy for bleeding angiodysplasias (resulting in anaemia) is indicated only if endoscopic coagulation has failed and other colorectal sources of bleeding (neoplasm, diverticulum or polyp) and especially angiodysplasias in the left colon or rectum have been excluded by endoscopy or angiography.

Adolescent↗
PubMed2005

CYP1A1 Val462 and NQO1 Ser187 polymorphisms, cigarette use, and risk for colorectal adenoma.

Cigarette use is a risk factor for colorectal adenoma, a known precursor of colorectal cancer. Polymorphic variants in NQO1 and CYP1A1 influence the activation of carcinogenic substances in tobacco smoke, possibly impacting on tobacco-associated risks for colorectal tumors. We investigated the association of cigarette smoking with risk for advanced colorectal adenoma in relation to the CYP1A1 Val(462) and NQO1 Ser(187) polymorphic variants. Subjects were 725 non-Hispanic Caucasian cases with advanced colorectal adenoma of the distal colon (descending colon, sigmoid and rectum) and 729 gender- and ethnicity-matched controls, randomly selected from participants in the prostate, lung, colorectal and ovarian cancer screening trial. Subjects carrying either CYP1A1 Val(462) or NQO1 Ser(187) alleles were weakly associated with risk of colorectal adenoma; however, subjects carrying both CYP1A1 Val(462) and NQO1 Ser(187) alleles showed increased risks (OR = 2.2, 95% CI = 1.1-4.5), particularly among recent (including current) (OR = 17.4, 95% CI = 3.8-79.8, P for interaction = 0.02) and heavy cigarette smokers (>20 cigarettes/day) (OR = 21.1, 95% CI = 3.9-114.4, P for interaction = 0.03) compared with non-smokers who did not carry either of these variants. These genotypes were unassociated with risk in non-smokers. In analysis of adenoma subtypes, the combined gene variants were most strongly associated with the presence of multiple adenoma (P = 0.002). In summary, joint carriage of CYP1A1 Val(462) and NQO1 Ser(187) alleles, particularly in smokers, was related to colorectal adenoma risk, with a propensity for formation of multiple lesions.

Adenoma↗