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Results for “Intestinal Polyposis”

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At least 361 records · Page 20Linked to original sources
PubMed2000

Chemopreventative activity of crude hydroxymatairesinol (HMR) extract in Apc(Min) mice [corrected].

We studied the effects of a lignan, hydroxymatairesinol (HMR), and rye bran on intestinal tumor development in adenomatous polyposis colimultiple intestinal neoplasia (Apc)(Min) mice. HMR showed a strong chemopreventive effect in this animal model. The mean number of adenomas in the small intestine was significantly lower (26.6+/-11.0, P<0.05) in mice fed the TNS tumor promoter insulin and HMR when compared with the insulin and insulin/rye bran fed mice (39.6+/-8.9 and 36.0+/-7.4, respectively). HMR resulted in normalization of beta-catenin levels in adenoma tissue, indicating that HMR mediates its chemopreventive effect through the Apc-beta-catenin pathway. In the cytosolic fraction, beta-catenin level in adenoma tissue was significantly elevated (P=0.008-0.013) in all the diet groups as compared with that of the surrounding mucosa. In the nuclear fraction, beta-catenin in the insulin (3.15+/-2.9 relative units) and insulin/rye (5.17+/-6.94 relative units) groups was also significantly higher (P=0.003-0.009) in the adenoma tissue when compared with the surrounding mucosa (0.5+/-0.5 and 0.35+/-0.39 relative units). However, HMR was able to restore nuclear beta-catenin level of the adenoma tissue (0.41+/-0.25 relative units) to the level found in the surrounding mucosa (0.36+/-0.28 relative units).

Adenomatous Polyposis Coli↗
PubMed2004

De novo crypt formation and juvenile polyposis on BMP inhibition in mouse intestine.

Little is known about the signaling mechanisms that determine the highly regular patterning of the intestinal epithelium into crypts and villi. With the use of mouse models, we show that bone morphogenetic protein (BMP)-4 expression occurs exclusively in the intravillus mesenchyme. Villus epithelial cells respond to the BMP signal. Inhibition of BMP signaling by transgenic expression of noggin results in the formation of numerous ectopic crypt units perpendicular to the crypt-villus axis. These changes phenocopy the intestinal histopathology of patients with the cancer predisposition syndrome juvenile polyposis (JP), including the frequent occurrence of intraepithelial neoplasia. Many JP cases are known to harbor mutations in BMP pathway genes. These data indicate that intestinal BMP signaling represses de novo crypt formation and polyp growth.

Adenoma↗
PubMedDate not supplied

[Peutz-Jeghers syndrome: an account of 3 cases in the same family and a review of the literature].

Peutz-Jeghers syndrome is a rare autosomal dominant polyposis characterized by mucocutaneous pigmentation, intestinal hamartomas and an increased risk mainly for gastrointestinal and gynaecological cancer. Our interest in this syndrome is due to the observation of three cases in the same family, two of whom presented the classic Peutz-Jeghers syndrome, while the other had perioral pigmentation only. Therefore, the main clinical elements emerge in the two first cases presenting with recurrent abdominal pain and sub-occlusion. The condition was managed by a combination of radiological, endoscopic and surgical procedures which enabled us to map and remove several gastrointestinal polyps. On histopathological examination the polyps were mainly hamartomas, though some presented both hamartomatous and adenomatous features, while others, removed endoscopically during the follow-up, were identified as true adenomas with initial carcinomatous changes. Furthermore, in one case follow-up examination allowed the early diagnosis and treatment of a cervical carcinoma. In agreement with the literature, our experience suggests that simple polypectomy, via an endoscopic and/or surgical approach, is the treatment of choice in Peutz-Jeghers syndrome. However, if gangrene due to invagination or neoplastic change occurs, an intestinal resection is mandatory. Cancer surveillance must be the first aim of follow-up.

Adult↗
PubMed1987

[Clinical evaluation of the condition of patients with ileostomy operated on for diffuse polyposis of the large intestine].

The work gives a clinical assessment of the state of 116 patients with ileostoma after radical surgery for diffuse polyposis of the colon. Metabolic disorders were noted in 40-50% of the patients with ileostoma for a long time after surgery. More than 60% of the patients do not participate in socially useful labor being the 1 and 2nd group invalids. Persons with ileostoma need dispensary observation, treatment at the hospital including therapeutic measures and reconstructive-restorative operations.

Adolescent↗
PubMed1976

[Diffuse polyposis of the large intestine as a precancerous condition].

In 86 (49.4%) of 173 patients cancer of the colon of various localizations against the background of diffuse polyposis was diagnosed, rectal involvement being noted in 50%, cancer involvement of the cecum involvement of the cecum and ascending colon--in 5.4% and 7.2% accordingly. These data made it possible to revise an existing concept of preservation of the rectum in radicalsurgery for diffuse polyposis in favour of remaining right portions of the colon.

Adolescent↗
PubMed2000

Non familial juvenile polyposis presenting as chronic intestinal obstruction.

Juvenile polyps are the commonest colonic polyps seen in children and present most often with rectal bleed. Intussusception is an extremely rare presentation in juvenile polyposis (JP) syndrome. This case highlights the rare association of ileo-colic intussusception with non-familial Juvenile Polyposis.

Biopsy, Needle↗
PubMed2005

The utility of capsule endoscopy small bowel surveillance in patients with polyposis.

BACKGROUND: Small intestinal (SI) surveillance is recommended for polyposis patients. The utility and safety of capsule endoscopy (CE) for surveillance of SI neoplasia in patients with familial adenomatous polyposis (FAP) and Peutz-Jeghers syndrome (PJS) is unknown. METHODS: CE was offered to consecutive FAP and PJS patients due for routine upper endoscopic surveillance. The prevalence, location (jejunum, ileum), size (1-5 mm, 6-10 mm, >10 mm) and number (1-5, 6-12, >20) of polyps detected by CE was assessed. RESULTS: 19 subjects (15 FAP/4 PJS) with a mean age of 43 were included. All subjects had previous intestinal surgery. No complications occurred with CE. CE in FAP: 9/15 (60%) of subjects with FAP had SI polyps. The prevalence of SI polyps was related to the duodenal polyposis stage and subject age. The location, size and number of polyps progressed as duodenal polyposis stage advanced. CE in PJS: 3/4 (75%) of subjects with PJS had SI polyps. The polyps were diffuse in 2/4 and only in the ileum in one subject. CE findings led to laparotomy with intra-operative endoscopic polypectomy in two PJS patients. CONCLUSION: SI polyps are common in FAP but their importance is unknown. CE should be performed in FAP patients with stage III and IV duodenal disease. Clinically significant polyps are commonly detected by CE in PJS and lead to change in management in 50% of PJS subjects. CE should replace radiographic SI surveillance for PJS patients. CE is safe in polyposis patients who have undergone major intestinal surgery.

Adenomatous Polyposis Coli↗
PubMed2004

Combined effects of cyclooxygenase-1 and cyclooxygenase-2 selective inhibitors on intestinal tumorigenesis in adenomatous polyposis coli gene knockout mice.

As with cyclooxygenase (COX)-2, genetic disruption of COX-1 gene or pharmacologic inhibition of its activity has been shown to decrease the number of intestinal polyps in Apc gene-deficient mice. The present study was designed to investigate the combined effects of COX-1 and COX-2 selective inhibitors on spontaneous polyp formation in APC1309 female mice. The animals were treated with 300 or 600 ppm mofezolac (a COX-1 selective inhibitor) alone, 200 or 400 ppm nimesulide (a COX-2 selective inhibitor) alone, 300 ppm mofezolac plus 200 ppm nimesulide, 600 ppm mofezolac plus 400 ppm nimesulide, or 10 ppm indomethacin (a dual-COX inhibitor) in the diet from 7 weeks of age for 4 weeks. Percentage inhibition of polyp area in the intestine was 17% with 600 ppm mofezolac alone and 25% with 400 ppm nimesulide alone, their sum of 42% being almost equal to the 37% observed for the combination treatment. Administration of 300 ppm mofezolac plus 200 ppm nimesulide also significantly decreased polyp area in the intestine by 30%. Moreover, the numbers of polyps more than 2.5 mm in diameter were markedly decreased by combined treatment of both COX inhibitors. With 10 ppm indomethacin, the dual inhibitor, polyp area was also clearly reduced by 46%. Our results indicate that COX-1 and COX-2 may to some extent contribute to polyp formation independently and inhibitor combination treatment thus has particular potential for chemoprevention of colon carcinogenesis.

Animals↗
PubMedDate not supplied

Reduction of intestinal neoplasia with adenomatous polyposis coli gene replacement and COX-2 inhibition is additive.

Mutations of the adenomatous polyposis coli (APC) gene are implicated early in colorectal tumorigenesis. Restoration of normal APC expression through gene therapy may prevent or reduce intestinal neoplasia. Furthermore, the relationship between colorectal tumors and increased cyclooxygenase-2 (COX-2) activity provides a rationale for the use of selective COX-2 inhibitors such as rofecoxib (Vioxx) to prevent the formation of polyps. This study was performed to determine the effects of liposome-mediated APC gene therapy and a selective COX-2 inhibitor on intestinal neoplasia in vivo. Five-week-old Min mice weaned on a 30% high-fat diet were randomized to receive no treatment (control), APC only, Vioxx only, and APC/Vioxx. APC-treated mice received a plasmid containing the human APC cDNA (pCMV-APC) mixed with a liposome preparation that was administered biweekly. Vioxx was administered at 200 ppm in the high-fat rodent chow. The control mice were treated similarly with a plasmid construct lacking the APC gene. Confirmation of exogenous APC gene expression was determined by Western blot analysis. After 2 months, there was a 54% and 70% reduction in the total number of intestinal polyps after APC and Vioxx treatment, respectively. Combined APC/Vioxx therapy reduced polyp formation by 87%. The reduction of intestinal neoplasia by APC gene replacement and COX-2 inhibition suggests their separate roles in intestinal tumorigenesis. Each modality, both individually and together, may prove therapeutic and therefore contribute to new strategies in the prevention and treatment of colorectal cancer.

Animals↗
PubMed1998

Absence of PTEN/MMAC1 germ-line mutations in sporadic Bannayan-Riley-Ruvalcaba syndrome.

Bannayan-Riley-Ruvalcaba syndrome (BRRS) is a rare hamartomatous polyposis condition with features of macrocephaly, intestinal juvenile polyposis, developmental delay, lipomas, and pigmentation spots of the male genitalia. An autosomal dominant pattern of inheritance exists in some families, but others appear as sporadic cases. Germ-line mutations in PTEN, a tyrosine phosphatase and putative tumor suppressor gene, have been demonstrated in two families with BRRS, and chromatin loss at the PTEN gene locus on chromosome 10q23 has been demonstrated in two BRRS patients. Germ-line mutations in PTEN have also been described in Cowden disease and in a small number of patients with juvenile polyposis syndrome. In an attempt to assess the nature of PTEN mutations in BRRS, we analyzed three sporadic BRRS patients for chromosome 10q23 deletion or PTEN germ-line mutations. All 3 patients demonstrated no loss of parental alleles at 15 chromosome 10q23 markers that encompassed the region of PTEN. In addition, analysis of mRNA and genomic DNA revealed no nonsense, missense, or insertion/deletion mutations of PTEN. Thus, other mechanisms besides mutation of PTEN must have occurred to cause BRRS in these patients. We speculate that BRRS and juvenile polyposis syndrome may have a heterogeneous etiology to cause their syndromes.

DNA↗
PubMed2006

Double-balloon endoscopy and Peutz-Jeghers syndrome: a new look at an old disease.

Peutz-Jeghers syndrome is a rare disease characterized by mucocutaneous hyperpigmentation and intestinal hamartomatous polyposis. Life-threatening complications include intestinal obstruction and increased risk of gastrointestinal malignancies. While colonoscopy continues to serve as the gold standard for examination of the colon, newer techniques such as capsule endoscopy and double-balloon endoscopy (DBE) are now being applied to both treatment and surveillance of this disease. Capsule endoscopy serves as a minimally invasive means of locating and characterizing polyps in symptomatic patients but is limited to detection only. DBE allows physicians to visit areas of the small bowel that were previously unreachable by older techniques and to treat lesions that are found. By using DBE to treat polyposis, hemorrhagic ulcers, angiodysplasia, strictures, and cancers, the number of small bowel resections can be decreased in these patients.

Journal Article↗
PubMedDate not supplied

Diagnosis and management of gastrointestinal polyps: pediatric considerations.

Painless, bright red, rectal bleeding with normal stool frequency and consistency is the hallmark presentation of colorectal polyps at any age. Most polyps in children are sporadic, usually isolated, colorectal juvenile polyps that do not require any further surveillance after they are removed. There is, however, increasing recognition of syndromes, including familial adenomatous polyposis, juvenile polyposis coli, Peutz-Jeghers syndrome, and infrequent conditions, such as PTEN hamartoma and hereditary mixed polyposis syndromes. The aim of this review is to allow the reader to correctly identify the patients who do not require follow-up and the smaller group of patients who do require follow-up because of syndromic polyp conditions.

Adenomatous Polyposis Coli↗