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Results for “Intestinal Polyposis”

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At least 325 records · Page 18Linked to original sources
PubMed2005

The threshold level of adenomatous polyposis coli protein for mouse intestinal tumorigenesis.

The adenomatous polyposis coli (APC) gene, whose mutations are responsible for familial adenomatous polyposis, is a major negative controller of the Wnt/beta-catenin pathway. To investigate the dose-dependent effects of APC protein in suppressing intestinal tumorigenesis, we constructed mutant mice carrying hypomorphic Apc alleles Apc(neoR) and Apc(neoF) whose expression levels were reduced to 20% and 10% of the wild type, respectively. Although both hypomorphic heterozygotes developed intestinal polyps, tumor multiplicities were much lower than that in Apc(Delta716) mice, heterozygotes of an Apc null allele. Like in Apc(Delta716) mice, loss of the wild-type Apc allele was confirmed for all polyps examined in the Apc(neoR) and Apc(neoF) mice. In the embryonic stem cells homozygous for these hypomorphic Apc alleles, the level of the APC protein was inversely correlated with both the beta-catenin accumulation and beta-catenin/T-cell factor transcriptional activity. These results suggest that the reduced APC protein level increases intestinal polyp multiplicity through quantitative stimulation of the beta-catenin/T-cell factor transcription. We further estimated the threshold of APC protein level that forms one polyp per mouse as approximately 15% of the wild type. These results also suggest therapeutic implications concerning Wnt signaling inhibitors.

Adenomatous Polyposis Coli Protein↗
PubMed1978

[Pathogenesis of polyposis of the large intestine].

As a result of the complex investigation of the functional-morphological status of the small intestine, it was shown that polyposis of the colon is associated with a natural involvement of the small intestine in the pathological process. It is felt that the pathology of the small intestine per se is one of the major pathogenetic trains of colonic polyposis, while its clinical manifestation is the result of the functional-morphological imcompetency of compensatory-adaptive reactions in the digestion system.

Adult↗
PubMed1993

Cytogenetic analysis of intestinal polyps in polyposis syndromes: comparison with sporadic colorectal adenomas.

Few cytogenetic studies of polyps from patients with polyposis syndromes have been reported. We studied 27 colonic adenomatous polyps from familial adenomatous polyposis (FAP), two polyps of the small bowel from Peutz-Jeghers syndrome (PJS), and four colorectal juvenile polyps from juvenile polyposis syndrome (JPS). The karyotypic results were compared with 32 sporadic colorectal adenomatous polyps. Nineteen colorectal adenomas had abnormal karyotypes; of these, five were from patients with FAP and 14 were sporadic adenomas. Numerical changes were the most frequent change (14 adenomas); additional copies of chromosome 7 (eight adenomas) and 13 (seven adenomas) occurred most often and were present in both FAP and sporadic adenomas. Only five adenomas, all sporadic, had structural chromosome abnormalities. Normal karyotypes were obtained from 32 adenomas, and chromosome counts but not karyotypes were obtained from eight polyps owing to poor chromosome morphology. The JPS and PJS polyps had normal karyotypes. These data indicate that adenomas from patients with FAP tend to have fewer structural abnormalities than sporadic adenomas and that numerical abnormalities are the most common chromosome abnormality in both FAP and sporadic polyps and suggest that the mechanism which causes loss of heterozygosity (LOH) in the adenoma to carcinoma sequence operates on a level below that of the whole chromosome.

Adenomatous Polyposis Coli↗
PubMed1997

Localization of the Bannayan-Riley-Ruvalcaba syndrome gene to chromosome 10q23.

BACKGROUND & AIMS: Bannayan-Riley-Ruvalcaba syndrome is a congenital syndrome with characteristic features of macrocephaly, cognitive and motor dysfunction, subcutaneous and visceral lipomas and hemangiomas, and intestinal juvenile polyposis. It has been suggested that Bannayan-Riley-Ruvalcaba syndrome may be a variant of juvenile polyposis coli because of the shared features of intestinal juvenile polyps. The aim of this study was to precisely map loss of DNA from 2 patients with intestinal juvenile polyposis and karyotypic abnormalities involving chromosome 10q. METHODS: DNA was extracted from peripheral leukocytes drawn from each patient and each patient's biological parents. The DNA was amplified by polymerase chain reaction using primers specific for microsatellites located on chromosome 10q. RESULTS: Precise mapping localized a maximal distance of 1.0 cM that was commonly deleted from each patient's genome, between D10S541 and D10S1735. This area overlaps the region for Cowden disease, a distinct hamartomatous intestinal polyposis syndrome with increased risk of breast and thyroid carcinoma. CONCLUSIONS: The three hamartomatous polyposis syndromes, Bannayan-Riley-Ruvalcaba syndrome, juvenile polyposis coli, and Cowden disease, may share the same genetic defect because of their common map localization to chromosome 10q23.

Adenomatous Polyposis Coli↗
PubMed1994

Expression of the mucosal homing receptor alpha 4 beta 7 in malignant lymphomatous polyposis of the intestine.

Recent studies have identified the integrin alpha 4 beta 7 as a mucosal homing receptor that mediates lymphocyte migration to the intestinal mucosa by binding to MAd-CAM-1, which is a vascular recognition molecule (adressin) selectively expressed on mucosal endothelium. The expression of the alpha 4 beta 7 mucosal homing receptor was studied in eight cases of malignant lymphomatous polyposis (MLP). This unusual presentation of non-Hodgkin's lymphoma of mantle cell type is characterized by multifocal lymphomatous involvement of the gastrointestinal tract. Unlike nodal mantle cell lymphomas, cases of MLP showed expression of alpha 4 beta 7, suggesting that this homing receptor plays an important role in determining the characteristic mucosal dissemination pattern of MLP.

Aged↗
PubMed1980

Studies on the difference of background mucosa among single advanced carcinoma and benign diseases of the large intestine, and familial polyposis coli.

The entire lengths of fixed specimens from 17 single advanced carcinomas of the colon (Cancer Group), four benign lesions (Benign Group), and four familial polyposis coli (Polyposis Group) were step-sectioned. It was found that the tubules of the basal cells were densely packed with rather a small number of goblet cells in the cancer and benign lesion specimens, but clear and loose with completely differentiated goblet cells in the polyposis coli specimens. Microscopic adenomas that were macroscopically unrecognizable and only microscopically detectable were found in 16 lesions in the Cancer Group, one lesion in the Benign Group, and in numerous lesions in the Polyposis Group. All of them developed from the basal cells. These findings indicate that the colonic mucosa of patients in the Cancer and Benign Groups is similar, but differs from that of the Polyposisis Group, and that microscopic adenomas are not uncommon in the Non-Polyposis Groups (Cancer and Benign Groups), findings which were not previously known.

Adenoma↗
PubMed1987

[Multiple lymphomatous polyposis of the intestinal tract].

The authors report on a patient suffering from centrocytic non-Hodgkin's lymphoma. Double contrast examination of the colon showed multiple, partially pedunculated polyps in the terminal ileum and colon. As cause of these lesions involvement of the bowel by lymphoma could be proved by biopsy. The differential diagnosis against other types of polyposis is discussed and the variable radiographical manifestations of the disease known as "multiple lymphomatous polyposis" are pointed out.

Adult↗
PubMed1984

Spontaneous polyposis in the small intestine of germ-free and conventionalized BALB/c mice.

The spontaneous polyposis in the small intestine of germfree (Gf) and conventionalized (Cv) BALB/c mice was studied. Gf mice were bred in our laboratory and maintained Gf in vinyl isolators. The first generation offspring of the Cv mice derived from the Gf mice was used as Cv animals. When they were 12 months old, the animals were killed under CO2 inhalation and autopsied carefully for the number and size of polyps with the aid of a dissecting microscope. The incidence of polyposis was higher in the Gf mice (68% in female and 89% in male) than in the Cv mice (37% in female and 51% in male). The number of polyps/mouse was also higher in the Gf mice (2.3 in female and 5.7 in male) than in the Cv mice (0.8 in female and 1.3 in male). All of the polyps were histopathologically adenomatous and developed only in the upper part (mainly duodenum) of the small intestine. The present study demonstrated that development of polyposis in the small intestine of BALB/c mice was suppressed by the presence of intestinal microflora.

Animals↗
PubMed1996

[Simultaneous occurrence and treatment of right atrial myxoma and extensive colonic polyposis causing recurrent intestinal hemorrhages].

The authors describe the case history of 68 year old man. Right atrial myxoma had been diagnosed two years prior to this present observation, however surgical intervention has been contraindicated due to high operative risk. Later the patient was referred to a cardiological evaluation because of chronic atrial fibrillation before a cataract surgery in a symptom free condition. The right atrial myxoma caused inflow obstruction and tricuspid regurgitation was removed before the eye surgery. In addition, tricuspid valve replacement and revascularization of three coronary arteries has been performed. The patient receiving chronic anticoagulant therapy experienced severe gastrointestinal bleeding the source of which turned out to be a partially malignant colon polyposis. The polyps were successfully removed by coloscopy and intra operative coloscopy. No gastrointestinal bleeding has been observed afterwards in spite of the continued anticoagulation. After review of the literature the authors observed that according to their knowledge the common occurrence of the right atrial myxoma and the colon polyposis had not been described before.

Aged↗
PubMed1997

A case of systemic malignant lymphoma with intestinal involvement of lymphomatous polyposis type.

Multiple lymphomatous polyposis is a rare type of intestinal lymphoma characterized by non-Hodgkin's lymphoma of follicular mantle cell origin and extremely poor prognosis. We report a case of systemic lymphoma with the intestinal involvement of multiple lymphomatous polyposis. Although radiographic and endoscopic features of the case were compatible with multiple lymphomatous polyposis, histologic evidence suggested the diagnosis of diffuse large cell lymphoma rather than mantle cell lymphoma. Our case seems to be unique in its histologic findings and also in its prognosis, because the patient has been alive for more than 50 months after diagnosis.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1986

[Endoscopic removal of small intestinal polyps in total polyposis of the digestive tract].

In patients with proliferative and mixed forms of total polyposis of the digestive tract the intestinal polyps are mainly localized in the duodenum, with hamartomal polyposis--in the jejunum and ileus. The endoscopic polypectomy from the small intestine may be performed intraoperatively and during endoscopy under narcosis. 174 polyps with the diameter of 0.5-5 cm were removed in 27 patients. There were 3 complications (bleedings) after polypectomy.

Adolescent↗