摘要:

SummaryEpidemiologic considerations, geographic pathology, and migrant studies definitely indicate that cancer in the gastrointestinal tract, in particular in the stomach and in the colon is mediated by environmental factors, especially dietary components. In recent years specific chemicals which induce cancer of the colon in animal systems have been discovered. Thus, model experiments are currently being performed to study the actions of environmental factors on the effectiveness of such chemicals in leading to colorectal cancer. Thus, hopefully, these experiments will pinpoint those agents in the environment which exert a controlling influence in this disease. Information on the metabolism of the chemical carcinogens affecting the lower gut indicates that certain of the metabolic steps may be performed in the liver, after which active metabolites are secreted in the bile in a protected conjugated form. The key ultimate carcinogen is then released in the colon by enzymes produced by bacterial microflora. A number of alternative pathways can also develop active carcinogens by microbial action in the gut, or by metabolic activation mediated by enzyme systems in colonic epithelium. Thus, studies of the effects of environmental agents in modifying flora in the lumens of specific enzyme systems in the intestinal wall are important in understanding the complex problems related to the etiology of colonic cancer.

ISSN:0012-3706    

出版商:OVID    

年代:1973

数据来源: OVID

摘要:

SummaryDimethylhydrazine, azoxymethane, and methylazoxymethanol are highly efficient intestinal carcinogens in the rat. Azoxymethane is the best, producing tumors in all rats. The lesions occurred in significant numbers in the small intestine when given at high dosage levels over a period of six months or more. The tumors tend to occur more in the proximal halves of both segments of the intestine.When the animals are fed a 2 per cent cholestyramine diet, there is a marked increase in the tumor yield and the increase is, for the most part, in the large intestine, especially its distal half. Investigations of the mechanisms whereby cholestyramine enhances tumor formation in the large intestine of the rat are continuing.We conclude that the rat given azoxymethane subcutaneously at weekly intervals while on a 2 per cent cholestyramine diet is an excellent experimental model for studies of colonic cancer.

ISSN:0012-3706    

出版商:OVID    

年代:1973

数据来源: OVID

摘要:

SummaryDetailed anatomy of the perineal body is described, with particular emphasis on the male because of the proximity of the urethra, which is important in perineal surgery. The perineal body, a fibromuscular mass, lies between the upper end of the anterior anal canal and the posterior portion of the urethral membrane and bulbocavernosus in the male, and between the upper half of the anterior anal wall and entire posterior portion of the vagina in the female. The female perineal body is much thicker and wider than that in the male, and compensates for the relatively weak and small single external sphincter anteriorty.

ISSN:0012-3706    

出版商:OVID    

年代:1973

数据来源: OVID

摘要:

SummaryChanges produced in the colon by prolonged ingestion of anthraquinones are loss of myenteric neurons, atrophy of the smooth muscle, and melanosis coli. After many years this may result in a functionless colon.

ISSN:0012-3706    

出版商:OVID    

年代:1973

数据来源: OVID

摘要:

SummaryThe dissecting‐microscopic appearance of the human rectal mucosa was studied in 147 biopsy specimens. The normal mucosa is divided into mucosal units by a “honeycomb” pattern of the rectal microvasculature, the center of each unit containing a refractile “pit” which may represent the mouth of the rectal crypt. The changes occurring in ulcerative colitis were graded according to severity of disturbance of the vascular channels, ranging from dilatation, neoformation and tortuosity of the individual vessels to complete disorganization of the “honeycomb” pattern. The vascular and “pit” changes in ulcerative colitis and other diseases of the rectum are described. The pathogenesis of the dissecting‐microscopic changes is discussed in relation to the normal vascular pattern of the human colonic mucosa.

ISSN:0012-3706    

出版商:OVID    

年代:1973

数据来源: OVID

摘要:

Summary and ConclusionClinical findings in this study showed that topical administration of 10 per cent hydrocortisone foam was usually advantageous in the treatment of ulcerative colitis. However, patients who also received Azulfidine by mouth did better than patients treated by topical steroids exclusively. Sometimes symptoms recurred, but in most cases the results were considered good. Of the 50 patients treated, the clinical responses in 38 were considered successful.On the basis of sigmoidoscopy, 18 of 50 patients in this study were “cured,” whereas only six were “cured” on the basis of mucosal biopsy.It might be expected that patients having rectal involvement only would respond better clinically than those having involvement of the entire colon. This was not the case, however, as the clinical responses were identical in the two groups.

ISSN:0012-3706    

出版商:OVID    

年代:1973

数据来源: OVID

ISSN:0012-3706    

出版商:OVID    

年代:1973

数据来源: OVID

ISSN:0012-3706    

出版商:OVID    

年代:1973

数据来源: OVID

摘要:

Summary and ConclusionAn analysis of the literature and our own experience with 180 patients strongly support the preoperative employment of intravenous pyelography in colorectal surgery.

ISSN:0012-3706    

出版商:OVID    

年代:1973

数据来源: OVID

摘要:

SummaryBarium‐enema studies of the colon undertaken in 1,007 patients with carcinoma of the rectum failed to demonstrate the rectal tumor in 16 per cent of cases, and failed to demonstrate coincidental tumors of the colon in 63 per cent of cases, and failed to demonstrate coincidental tumors of the colon in 63 per cent of patients with such tumors. Additionally there was a 25 per cent incidence of false‐positive findings in the colon.The consequence of this analysis is that we no longer undertake barium‐enema studies of the colon in patients with carcinoma of the rectum confirmed by palpation or proctoscopy. The effect of this is that the surgeon is very aware of the importance of hisperoperative palpation, and palpation has proved to be very much more reliable for detecting coincidental tumors of the colon than preoperative barium‐enema studies.

ISSN:0012-3706    

出版商:OVID    

年代:1973

数据来源: OVID