Melatonin and colon carcinogenesis: I. Inhibitory effect of melatonin on development of intestinal tumors induced by 1,2-dimethylhydrazine in rats

The effect of pineal indole hormone melatonin on colon carcinogenesis was firstly studied in rats. Two-month-old outbred female LIO rats were weekly exposed to 15 (experiment 1, groups 1 and 2) or to five (experiment 2, groups 1 and 2) s.c. injections of 1,2-dimethylhydrazine (DMH) at a single dose of 21 mg/kg of body weight. From the day of the first injection of the carcinogen DMH, the rats from groups 2 (experiments 1 and 2) were given melatonin five days a week during the night-time (from 18:00 h to 8:00 h), dissolved in tap water at 20 mg/l. The experiment was finalized in 6 months after the first injection of DMH. In both experiments the majority of tumors were localized in the descending colon. Tumors of the small intestines developed only in rats from experiment 1. Total incidence of colon tumors as well as tumors in different parts of the colon and the mean number of tumors per rat were much higher in rats from both groups in experiment 1 than that in rats from experiment 2. In experiment 1 melatonin failed to influence the total incidence of colon tumors. However, incidence of carcinomas in the ascending colon was significantly reduced (P < 0.01). The multiplicity of total colon tumors per rat, as well as the mean number of tumors, ascending and descending colon per rat, was also decreased under the influence of melatonin (group 2 vs group 1, P < 0.01). In the same experiment, melatonin slightly decreased the depth of tumor invasion and increased number of highly differentiated colon carcinomas induced by DMH. The percentage of small tumours in the descending colon among rats from group 2 was higher than that of group 1. Treatment with melatonin was also followed by a decrease in the multiplicity of DMH-induced tumors of the duodenum (group 2 vs group 1, P < 0.05) and by a decrease in the incidence of jejunum and ileum tumors (group 2 vs group 1, P < 0.05). In experiment 2, the inhibitory effect of melatonin on DMH-induced colon carcinogenesis was much more expressed than that in experiment 1. Thus, in group 1 the incidence of total colon tumors, ascending and descending colon tumors, was significantly decreased in comparison with group 2; also melatonin reduced the number of tumors per rat in the ascending and descending colon. The number of colon tumors that invaded only mucosa was significantly higher in group 2 than in group 1, P < 0.05. The ratio of highly differentiated tumors was increased (P < 0.05) and the ratio of low-differentiated tumors was decreased (P < 0.05) in rats exposed to melatonin (group 4) as compared with group 3. The number of large size tumors in the ascending and descending colon was decreased whereas the number of small size tumors (<10 mm2) was increased in those parts of the colon that were under the influence of melatonin in experiment 2. Thus, our results demonstrate the inhibitory effect of melatonin on intestinal carcinogenesis induced by DMH in rats.     

Calcium, vitamin D, and dairy foods and the occurrence of colon cancer in men

To examine the associations between intakes of calcium, Vitamin D, and dairy foods and the risk of colon cancer, the authors analyzed data from a prospective study of 47,935 US male professionals, 40-75 years of age and free of cancer in 1986. Within this cohort, 203 new cases of colon cancer were documented between 1986 and 1992. After adjusting for age and total energy intake, the authors found that the intake of calcium from foods and supplements was inversely associated with colon cancer risk (relative risk (RR) = 0.58, 95% confidence interval (CI) 0.39-087 between high and low intakes of calcium). However, after adjusting for confounding variables, they found that the trend was no longer statistically significant (p = 0.22), and the relative risk for the highest quintile group of intake was attenuated: 0.75 (95% CI 0.48-1.15). Similar results were observed for total vitamin D intake; the age- and energy-adjusted relative risk was 0.54% (95% CI 0/34-0/85) for the highest versus lowest quintile group, and this was attenuated in the multivariate model (RR = 0.66, 95% CI 0.42-1.05). The inverse association was weaker for dietary vitamin D (RR highest vs. lowest quintile = 0.88. 95% CI 0.54-1.42) and strongest for vitamin D arising from vitamin supplements (RR = 0.48, 95% CI 0.22-1.02). Thus, it is possible that other components of multivitamin use rather than vitamin D accounted for the reduction in risk. Consumption of milk and fermented dairy products was not significantly associated with the risk of colon cancer; individuals consuming two or more glasses of "whole" or skim milk per day had a relative risk of 1.09 (95% CI 0.69-1.72), compared with those who consumed "whole or skim milk less than once a month. These prospective data do not support the hypothesis that calcium intake is strongly protective against colon cancer risk, although a modest association cannot be excluded.     

Physical activity and risk of colorectal cancer in men and women

We examined the association between self-reported occupational and recreational physical activity and the subsequent risk of colorectal cancer in a population-based cohort in Norway. During a mean follow-up time of 16.3 years for males and 15.5 years for females, 236 and 99 colon cancers and 170 and 58 rectal cancers were observed in males and females, respectively, among 53,242 males and 28,274 females who attended the screening between 1972 and 1978. Physical activity at a level equivalent to walking or bicycling for at least four hours a week during leisure-time was associated with decreased risk of colon cancer among females when compared with the sedentary group (RR = 0.62, 95% CI 0.40-0.97). Reduced risk of colon cancer was particularly marked in the proximal colon (RR = 0.51, 95% CI 0.28-0.93). This effect was not observed for occupational physical activity alone, probably due to a narrow range of self-reported physical activity at work among females. However, by combining occupational and recreational physical activity we observed an inverse dose-response effect as increasing total activity significantly reduced colon cancer risk (P for trend = 0.04). Among males 45 years or older at entry to the study, an inverse dose-response effect was observed between total physical activity and colon cancer risk (P for trend = 0.04). We also found in males a stronger preventive effect for physical activity in the proximal as compared to distal colon. In addition, we found a borderline significant decrease in colon cancer risk for occupational physical activity in males 45 years or older when compared to the sedentary group (RR = 0.74, 95% CI 0.53-1.04). All results were adjusted for age, body mass index, serum cholesterol and geographic region. No association between physical activity and rectal cancer was observed in males or females. The protective effect of physical activity on colon cancer risk is discussed in regard to energy balance, dietary factors, age, social class, body mass index and gastrointestinal transit time.     

A multiparametric computer analysis of carcinoma of the colon

From 1957 to 1973, 656 patients with carcinoma of the entire colon, excluding those with carcinoma of the rectum, were reviewed with the aid of a computer. Of 457 patients, 69.7 per cent were observed for a minimum of five years. Sixty-five per cent of the lesions were located in the cecum or sigmoid colon. In patients with type A lesion, the five year plus survival rate was 71.15 per cent while, in patients with type D lesions, the five year plus survival rate was zero per cent. Patients who presented with intestinal obstruction had a significantly lower five year survival rate. Roentgenographic visualization of the cecum was significantly less accurate in demonstrating carcinoma when compared with that of the sigmoid colon. An emergency surgical procedure had a significantly higher operative mortality than did elective procedures. In both groups of patients undergoing emergency and elective operations, primary resection and anastomosis led to similar operative mortality rates, although staged procedures resulted in the lowest operative mortality in both groups. In the group of patients who had elective operations, resection an primary anastomosis led to a significantly lower wound infection and fistula rate when compared with the group of patients who had emergency procedures. In comparison with other series, no improvement in survival was illustrated in patients with carcinoma of the colon. The use of new modalities of adjuvant therapy, such as radiotherapy or chemotherapy, or both, actually should be evaluated.     

The growth law of primary breast cancer as inferred from mammography screening trials data

BACKGROUND: A potential source of bias in epidemiological studies comes from studying people at different stages of disease progression. This can result in biased selection of cases or in errors of measurement of exposures. METHODS: We use stage of disease at the time of diagnosis to evaluate how inclusion of people at different stages in the disease process can influence associations between environmental exposures and colon cancer. Data used were generated from a large case-control study of colon cancer. RESULTS: For most environmental exposures evaluated, including physical activity, body size, use of aspirin and of non-steroidal anti-inflammatory drugs, and dietary intake of folate and fibre, we did not observe differences in patterns of association by stage of disease at diagnosis. However, for total energy and red meat intake (men only), alcohol consumption, cigarette smoking, and family history of colorectal cancer among first degree relatives, patterns of associations were stronger when colon cancer was detected at an earlier stage of disease progression than when it was detected at a more advanced stage. CONCLUSIONS: Most exposures did not differ by stage of disease, thus selectively excluding cases at different disease stages should not influence associations between these exposures and colon cancer. Associations for other factors, such as alcohol consumption and cigarette smoking, may be biased from asking cases with advanced disease to recall a non-disease-free time period. Associations with family history may also be biased if those with a family history of colorectal cancer are detected at an earlier stage and therefore more likely to participate in epidemiological studies.     

Immunonutrition: the role of carbohydrates

The major role for carbohydrates in the diet is for the provision of energy. Most non-energy-related effects of carbohydrates can be related to short-chain fatty acid production or other effects of bacterial fermentation in the colon. More complex or slowly absorbed carbohydrates may also reduce glycemic index and insulin production and therefore may have a less profound effect on modification of lipid metabolism. Certain carbohydrates may promote fermentation in the colon, increasing short-chain fatty acid production and may alter bacterial flora in the small bowel and colon. Increased insoluble fiber will increase fecal bulk. Further immunomodulary effects of carbohydrates have had little attention in the literature. This would be a potential opportunity for further investigation.     

Identification of proteins that interact with a protein of interest: applications of the yeast two-hybrid system

Colorectal cancer remains a major health problem. Few therapies are effective apart from surgery, and survival has increased little in recent years. This is despite the fact that screening by colonoscopy can potentially remove nearly all colorectal tumours before they become malignant. Molecular genetics has identified some inherited mutations (such as at APC and the mismatch repair loci) that predispose to colon cancer and some somatic mutations (such as at APC and p53) that cause sporadic colon tumours. We review the likely role of these and other genes in colorectal tumorigenesis. We also highlight areas of relative ignorance in colon cancer and emphasise that many important genes, especially those that cause invasion and metastasis, remain to be identified. Colorectal cancer is, however, a well characterised tumour, as regards both its natural history and its histopathology; there are consequently good prospects for advances in colon cancer genetics, with probable benefits for its treatment. We anticipate: (a) that new genes predisposing to colon tumours, including those conferring relatively minor risks, will be characterised; (b) genes and proteins important in invasion and metastasis will be identified; (c) the network of protein interactions in which molecules such as APC are involved will be elucidated; (d) large-scale studies of somatic mutations in tumours will provide accurate predictions of prognosis and suggest optimal therapeutic regimens; and (e) new potential targets for therapy will be identified. Whilst molecular genetics is by no means sufficient for progress in preventing and treating colon cancer, it is a necessary and central part of such advances.     

Portal hypertensive colopathy: histologic appearance of the colonic mucosa

BACKGROUND/AIMS: The aim of this study was to evaluate macroscopic and histologic disorders of the colon in rats with portal hypertension. METHODOLOGY: The animals were divided into two groups: 10 rats in the experimental group and 10 controls. Portal hypertension was induced by a partial ligation of the portal vein. We assessed the histologic appearance and macroscopic alterations of the colonic mucosa 12 weeks after the induction of portal hypertension. RESULTS: The macroscopic results showed the presence of the typical signs of portal hypertension, with dilatation and tortuosity of the mesenteric veins and hyperemia of the rectum and colon. Histologic study revealed a marked dilatation in the microcirculation at the level of the ascending colon (20 +/- 2 micra in diameter) and rectum (30 +/- 4), with a tendency to group the lesions. Submucosal edema without inflammatory signs was observed. CONCLUSION: The existence of these lesions in the colon and rectum can be the cause of hemorrhage, as in the gastropathy of portal hypertension and should be considered in cases of undiagnosed hemorrhage in patients with portal hypertension.     

Food intakes of adult Melbourne Chinese

Food intake patterns of 545 adult Melbourne Chinese were studied in 1988 and 1989 using a 220-item food-frequency questionnaire appropriate for Chinese eating practices. Men and women were compared, adjusting for age, time in Australia and education. Men consumed more rice and alcoholic beverages as energy. In women, the energy intake was derived from foods of traditional Chinese types. There were two types of consumption patterns: in the first group were those who acculturated towards an Australian way of eating by replacing some traditional Chinese foods, such as rice, pork, leafy green and cruciferous vegetables, soups and tea, with 'new foods', such as wheat products, red meats and coffee; in the second were those who limited their intake to a handful of traditional Chinese foods as the major source of energy. The educated, the professional and those with an administrative profession, the Australian-born and those with a longer length of stay fitted into the first group, and were more acculturated towards Australia than those born in the People's Republic of China or Vietnam and who migrated at an older age. The first group may benefit from the best of both worlds, but may risk the diseases of an industrialised society. The second group may be trapped at a cultural crossroads and may be unable to make appropriate food choices. Public health efforts in Australia, where one in every five is overseas-born, should provide for nutrition and health education for new and aged migrants of non-European cultural backgrounds.     

An organ culture method for adult colon from germfree and conventional mice: effects of donor age and carcinogen treatment on epithelial mitotic activity

An organ culture system by which adult mouse colon epithelium could be maintained in a modified form for several weeks was described. The effects of donor age and carcinogen pretreatment were studied as a preliminary to proposed experiments on the effect of carcinogen treatment in vitro on colon epithelium from mice of different ages. Mitotic activity was compared in explants of colon from germfree C57BL mice 5 weeks, 5 months, and 9 months old; no differences were detected. The effect of old age on mitotic activity was not studied, since colon epithelium from old (30 mo) conventional mice could not be maintained in culture. Colon explants from conventional mice that had been pretreated for 32 weeks with weekly doses of a carcinogen, 1,2-dimethylhydrazine, appeared to have a higher potential for mitotic activity in vitro than did those from age-matched, untreated controls, but the difference was only significant at the 10% level. The epithelial cells were normal in ultrastructure, and the method may be valuable for studies of the direct effects of substances on adult colon epithelium.     

Increased socioeconomic differences in mortality in eight Spanish provinces

In Spain, the study of socioeconomic differences in mortality has been limited by the fact that death certificates often do not include complete information on occupation. In this study, we chose those geographic areas with the highest quality information on occupation of the deceased in order to study socioeconomic differences in mortality from various causes of death. We used information from the death certificates of males who died between 30 and 64 years of age in eight Spanish provinces to compare mortality from the leading causes of death in professionals and managers (group I) and in manual laborers (group II) in 1980-82 and 1988-90. In each period the standardized mortality ratios (SMRs) were higher in group II, except for ischaemic heart disease during the first period, and cancer of the colon and rectum in both, although in the latter case the differences were not statistically significant. The ratio between the SMR from all causes in group II and group I was 1.27 in 1980-82, and 1.72 in 1988-90; for cancer of the colon and rectum the ratio went from 0.98 to 0.84, and for ischaemic heart disease, from 0.80 to 1.31. Except for cancer of the colon and rectum, which resulted in higher mortality in occupational group I, the excess mortality in occupational group II increased between the first and second period. The relation between socioeconomic level and mortality for ischaemic heart disease was reversed, a phenomenon similar to that which took place in the 1960s and 1970s in the developed countries.(ABSTRACT TRUNCATED AT 250 WORDS)     

Electrophysiological characteristics of submucosal neurones in the proximal colon of guinea-pigs: comparisons with caecum and descending colon

A systematic examination has been made of the active and passive electrophysiological properties and synaptic inputs of forty-four randomly impaled submucosal neurones in the proximal colon of the guinea-pig to compare these characteristics directly with those of submucosal neurones in the caecum (n = 70) and descending colon (n = 45). Within each of the three electrophysiological classes of submucosal neurones identified (S, S/AH and AH), no statistically significant regional differences were found with respect to the resting membrane potential, membrane time constant or input resistance between neurones of the proximal colon, descending colon and caecum. Of submucosal neurones from the proximal colon, forty-three of forty-four (98%) received fast excitatory synaptic potentials (fast EPSPs); thirty-nine (91%) were S neurones and the others were S/AH neurones; only one of the forty-four cells (2%) was an AH neurone. An idazoxan-sensitive slow inhibitory postsynaptic potential (slow IPSP) was induced in thirty of forty-three S and S/AH neurones (70%) of the proximal colon, compared with sixty-one of sixty-six caecal neurones (92%) and twelve of forty-one neurones (29%) in the descending colon. The mean (+/- S.E.M.) amplitude of the slow IPSP in proximal colonic neurones was 17 +/- 1 mV (range, 6-30 mV; n = 30), compared with the significantly larger synaptic response (25 +/- 1 mV; range, 7-38 mV; n = 66; P < 0.05) recorded in the caecum; the mean slow IPSP amplitude in the descending colon was significantly smaller (12 +/- 2 mV; range, 5-27 mV; n = 12; P < 0.05) than that in the caecum. In the proximal colon and caecum, only those neurones with a slow IPSP had a hyperpolarizing response to noradrenaline, whereas about 50% of those neurons of the descending colon that lacked a slow IPSP were hyperpolarized by noradrenaline, acting via alpha 2-adrenoceptors. Thus, the electrophysiological characteristics of the submucosal neurones of the proximal colon more closely resemble those of the caecum than those of the descending colon, of which many do not have a functional noradrenergic synaptic input. Furthermore, the results confirm that there are fundamental regional differences in the guinea-pig large intestine with respect to the synaptic organization of submucosal neurones of particular electrophysiological classes.     

The short bowel syndrome: what's new and old?

Conditions which resulted in colonic preservation such as strangulated hernia, intestinal volvulus, and mesenteric infarction were once the main reasons for a major intestinal resection leading to the short bowel syndrome. Now Crohn's disease is the most common underlying diagnosis; such patients often have a jejunostomy. A measurement of the residual jejunal length from the duodenojejunal flexure makes possible predictions of patient outcome. Patients with a jejunostomy and less than 100 cm jejunum usually need long-term parenteral support, whereas 50 cm or more of jejunum usually suffices for adequate oral nutrition if the colon is preserved. While patients with and without a colon have problems with nutrient absorption, those with a jejunostomy also have problems of water, sodium and magnesium losses. Stomal losses may exceed oral intake and all such patients ('secretors') need parenteral supplements. Fluid and sodium losses can be reduced by octreotide, omeprazole or H2 blockers but not sufficiently to avoid the need for intravenous supplements. Colonic preservation increases the incidence of calcium oxalate renal stones (20%). Patients with and without a colon have a high prevalence of gallstones (40%). Clinically important intestinal adaptation occurs in those with a colon but not in those with a jejunostomy. Many surgical techniques, including small bowel transplantation, have been suggested to improve absorption, but as the quality of life of most patients with a short bowel is good with current treatments, they are not at present recommended.     

Iron intake and the risk of colorectal cancer

Prospectively gathered data from the National Health and Nutrition Examination Survey I and the National Health Evaluation Follow-Up Study were analyzed to evaluate the risk of colorectal cancer due to consumption of iron. Morbidity and mortality data due to colorectal cancer were available on 14,407 persons first interviewed in 1971 and followed through 1986. A total of 194 possible colorectal cancers occurred in this group over the 15-year period. Subsite analysis showed that the risk of colon cancer due to iron intake was elevated throughout the colon for both men and women, with the highest adjusted risks for the interquartile range seen in the proximal colon for females (relative risk, 1.51; 95% confidence interval, 1.41-1.60). The risk of rectal cancer was not significantly elevated for men or women. Elevated serum iron was also associated with increased risk; however, this effect was strongest in the distal (rather than proximal) colon and was significant only among females (adjusted relative risk, 1.73; 95% confidence interval, 1.03-2.92). The mean transferrin saturation was higher among cases than controls (30.7 versus 28.7%), but total iron-binding capacity did not seem to predict the occurrence of colorectal cancer. Proportional hazards models confirmed that the effects of iron and serum iron were not confounded by age, gender, energy consumption, fat intake, or other known risk factors for colorectal cancer. These data suggest that iron may confer an increased risk for colorectal cancer, and that the localization of risk may be attributable to the mode of epithelial exposure. It seems that luminal exposure to iron increases risk proximally, whereas humoral exposure increases risk distally. These differences may be due to such factors as oxidation state, binding proteins and the presence of other cofactors such as bile acids, products of bacterial metabolism.     

Does CTAP prior to hepatic resection improve patient survival rates?

The purpose of our study was to compare survival rates of colon carcinoma patients who had undergone attempted curative hepatic resection based on liver staging by computed tomographic angiography (CTA) or portography (CTAP) with previously reported survival rates of patients who underwent similar surgery without preoperative CTAP evaluations. A total of 404 CTAP studies performed at three institutions were reviewed. Of this group, 197 had colon carcinoma. Sixty-nine of the colon patients went to surgery. Actuarial adjusted yearly survival rates were calculated for the prior CTAP colon group and compared to historical controls. The control survival data were taken from reports published prior to the CTAP era. Our study demonstrated no difference in the 1-year survival data between the groups. However, the CTAP patients had greater survival in years 2-4. This greater survival may be multifactorial but in part due to better surgical selection caused by CTAP.     

Antitumor activity of 2-chloro-9-(2-deoxy-2-fluoro-beta-D-arabinofuranosyl) adenine, a novel deoxyadenosine analog, against human colon tumor xenografts by oral administration

2-Chloro-9-(2-deoxy-2-fluoro-beta-D-arabinofuranosyl) adenine (Cl-F-araA) is a novel deoxyadenosine analog, which inhibits DNA synthesis by inhibiting DNA polymerase alpha and ribonucleotide reductase. Cl-F-araA shows potent antiproliferative activity against several leukemic cell lines including those of human origin and is also effective against murine solid tumors, in particular being curative against colon tumors. PURPOSE: We therefore decided to investigate whether Cl-F-araA is effective against human colon tumors, in particular by oral administration, since it has improved stability compared with other deoxyadenosine analogs. METHODS: Antiproliferative activity in vitro was determined from cell counts. Subcutaneously inoculated xenograft models and a liver micrometastases model were used for assessment of antitumor activity in vivo. RESULTS: Cl-F-araA showed potent antiproliferative activity against four human colon tumor cell lines (HCT116, HT-29, DLD-1, WiDr), with a 50% growth-inhibitory concentration (IC50) of 0.26 microM with a 72-h exposure. This activity was greater than those of fludarabine desphosphate and cladribine, other deoxyadenosine analogs, which showed IC50 values of 19 microM and 0.35 microM, respectively. Cl-F-araA showed potent antitumor activity against four human colon tumor xenograft models (HT-29, WiDr, Co-3, COLO-320DM) in a 5-day daily administration schedule, which was shown to be the most effective of three administration regimens tested (single, twice-weekly, 5-day daily). In particular, oral administration showed significantly superior activity, with a regressive or cytostatic growth curve, compared with intravenous administration. In addition, Cl-F-araA was effective at only one-sixteenth of the maximum dose tested in a 10-day daily administration schedule. Therapeutic efficiency seemed to increase in proportion to the frequency of administration. Cl-F-araA also decreased liver micrometastases created by intrasplenic injection of human colon tumor cells, leading to complete suppression at the maximum dose tested. CONCLUSIONS: These results suggest that Cl-F-araA might be clinically effective against human colon cancers using a daily oral administration schedule.     

Video-imaging and treatment presentation: medico-legal implications and patient perception

Peripheral blood leukocyte alkaline phosphatase (LAP) scores and CA15-3, CA125, and CEA levels in plasma were measured in 57 patients with metastatic breast, ovarian, and colorectal cancer, respectively, and in 79 patients with the same types of nonmetastatic cancer. The mean LAP scores of the metastatic cancer patients (261, 272 and 275 for breast, ovary and colon, respectively) were significantly higher than those of the nonmetastatic cancer group (70, 68 and 57, respectively). There was no overlap between the 95% confidence intervals of the two groups (i.e., metastatic versus nonmetastatic), and no patient known to be metastatic had a LAP score within the normal range. The mean levels of other markers in the metastatic patients (CA15-3, 63.4 mu/ml; CA125, 104.8 mu/ml; and CEA, 51.8 ng/ml for metastatic breast, ovarian, and colon cancer, respectively) were also higher than in the nonmetastatic patients (CA15-3, 24 mu/ml; CA125, 25.3 mu/ml; and CEA, 5.8 ng/ml for nonmetastatic breast, ovarian, and colon cancer, respectively). However, the 95% confidence intervals of the nonmetastatic and the metastatic patients overlapped so that there were false-negatives and/or false-positives when the other markers were used. We therefore conclude that the addition of the LAP score to conventional cancer markers could be helpful for the diagnosis of recurrence and follow-up of cancer patients and suggest that our results be confirmed by further studies on a larger series of patients.     

The role of coloscopy in the differential diagnosis between idiopathic ulcerative colitis and Crohn's disease of the colon

The authors point out the striking significance of coloscopy in establishing a correct diagnosis of inflammatory diseases of the colon. In particular, the most valuable endoscopic features are indicated which may permit distinguishing between idiopathic ulcerative colitis and Crohn's disease of the colon. Differentiation between these two diseases cannot always be achieved by means of available diagnostic procedures other than coloscopy. Moreover, the endoscopic findings enable an assessment to be made of the extent, stage, severity and course of either disease. The authors' experience encompass 2,478 coloscopy examinations: the observed cases of idiopathic ulcerative colitis are 182, those of Crohn's disease of the colon are 104.     

Change in colonic motility after extrinsic autonomic denervation in dogs

Changes in colonic motility were compared in dogs undergoing autonomic denervation of the paraaortic and presacral (group A), paraaortic (group B), or mesocolonic region (group C), and sham operation (group D). Five bipolar recording electrodes were placed into the seromuscular layer of the colon and rectum. The numbers of continuous electrical response activity and contractile electrical complex after an intragastric olive oil injection were smaller in group A than in the other groups (P < 0.05) from three weeks through six months after denervation. This difference was significant even in the proximal colon. These data suggest that the pelvic plexus may play an important role in colonic motility including the proximal colon. The damage to the plexus did not recover for at least six months after denevation. Pelvic plexus injury may thus be one of possible explanations for the prolonged change in bowel habit after anterior resection of the rectum.