PubMed HealthSearch

PubMed · 7254052

Colonoscopic polypectomy.

Abstract

Seven hundred and forty-one colonic polyps have been removed by colonoscopic polypectomy during 300 examinations. Up to 36 polyps were removed at a single examination. Colonoscopic treatment of villous adenomas to 7 cm has been successfully performed in elderly and infirm patients. There were no deaths or incidents of perforation and the only significant complications were two secondary haemorrhages requiring transfusion. The presence of a polyp was not definitely reported in 40% of barium enema X-ray examinations carried out within three months of polypectomy. Double contrast X-ray examinations were significantly more sensitive in the detection of polyps. Colonoscopic polypectomy is a safe and effective technique. All colonic polyps should be removed by this technique after diagnosis.

Explore related subjects

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

A E Cowen, R W Stitz, M Ward. 1981-06-13. Colonoscopic polypectomy.. https://doi.org/10.5694/j.1326-5377.1981.tb135889.x

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related citations

HMGA proteins up-regulate CCNB2 gene in mouse and human pituitary adenomas.

The high mobility group As (HMGAs) belong to a family of nonhistone nuclear proteins that orchestrate the assembly of nucleoprotein complexes. Through a complex network of protein-DNA and protein-protein interaction, they play important roles in gene transcription, recombination, and chromatin structure. This protein family is involved, through different mechanisms, in both benign and malignant neoplasias. We have recently reported that transgenic mice carrying the Hmga1 or Hmga2 genes under transcriptional control of the cytomegalovirus promoter develop pituitary adenomas secreting prolactin and growth hormone. We have shown that the mechanism of the HMGA2-induced pituitary adenoma is based on the increased E2F1 activity. The expression profile of mouse normal pituitary glands and adenomas induced in HMGA transgenic mice revealed an increased expression of the ccnb2 gene, coding for the cyclin B2 protein, in the neoplastic tissues compared with the normal pituitary gland. Here, we show, by electrophoretic mobility shift assay and chromatin immunoprecipitation, a direct binding of HMGA proteins to the promoter of ccnb2 gene, whereas luciferase assays showed that HMGAs are able to up-regulate ccnb2 promoter activity. Finally, we report an increased CCNB2 expression in human pituitary adenomas of different histotypes that is directly correlated with HMGA1 and HMGA2 expression. Because cyclin B2 is involved in the regulation of the cell cycle, these results taken together indicate that HMGA-induced cyclin B2 overexpression gives an important contribution to experimental and human pituitary tumorigenesis.

Adenoma

Intestinal tumorigenesis is suppressed in mice lacking the metalloproteinase matrilysin.

Matrix metalloproteinases (MMPs) classically have been implicated in basement membrane destruction associated with late-stage tumor cell invasion and metastasis. However, recent studies have demonstrated that one MMP family member, matrilysin, is expressed in a high percentage of early-stage human colorectal tumors. We analyzed matrilysin expression in benign intestinal tumors from mice heterozygous for the ApcMin allele (Min/+) and found that the mRNA was induced in the majority (88%) of these adenomas. Protein was detected in the tumor cells, where, surprisingly, it was predominantly immunolocalized to the lumenal surface of dysplastic glands rather than the basement membrane or extracellular matrix. To address the role of matrilysin in Min intestinal tumorigenesis, we generated Min/+ mice deficient in this MMP by gene targeting and homologous recombination. The absence of matrilysin resulted in a reduction in mean tumor multiplicity in Min/+ animals of approximately 60% and a significant decrease in the average tumor diameter. Based on these findings, we conclude that matrilysin is a suppressor of the Min phenotype, possibly by functioning in a capacity independent of matrix degradation. These results argue for the use of MMP inhibitors in the treatment and prevention of early-stage colon cancer.

Adenoma

Clonality of dysplastic epithelium in colorectal adenomas from familial adenomatous polyposis patients.

Loss of function of both alleles of the APC gene results in colorectal adenoma formation in familial adenomatous polyposis, an autosomal dominant genetic disorder leading to multiple colorectal tumors at an early age. Previous molecular studies indicate that the mutant cells forming dysplastic epithelium within adenomas are clonally derived. We show, using immunostaining and molecular techniques, that the dysplastic epithelium of adenomas actually contains a mixture of cells derived from both mutant and normal stem cells. Well-differentiated mucous cells in the dysplastic epithelium, one of the indicators of severity of dysplasia, were derived from normal stem cells. Carcinomas in these patients, in contrast, contained only mutant cells, indicating that the subsequent mutations incurred by these cells have led to their isolation from the normal population.

Adenoma