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The large intestine compensates for insufficient calcium absorption in the small intestine in rats.

We previously demonstrated that the large intestine compensated for decreased calcium (Ca) absorption caused by renal failure in rats fed a highly fermentable dietary fiber. In this study, we examined whether the large intestine compensated for insufficient Ca absorption in the rat small intestine without ingestion of a fermentable dietary fiber. Rats were fed one of four test diets containing either insoluble (carbonate) or soluble (gluconate, lactate, or citrate) Ca sources. The dietary Ca level was 2.0 g/kg, which is lower than the minimum requirement for rats (3.0 g/kg), to conduct the present study under a condition in which rats can maximally absorb Ca. To prevent Ca absorption in the small intestine, we replaced a primary phosphate (KH2PO4) with secondary phosphates (K2HPO4 and Na2HPO4) in diets. The apparent Ca absorption in the small intestine was estimated by adding chromic oxide (Cr2O3) as an insoluble and an unabsorbed marker to test diets and by measuring the ratio of Ca:Cr in the cecal content. The apparent Ca absorption in the whole intestine was estimated by the intake and fecal excretion of Ca. The apparent Ca absorption in the small intestine was significantly lower from the Ca carbonate diet than from the Ca gluconate, lactate, or citrate diets. The apparent Ca absorption in the whole intestine was not significantly different among the four groups, and the values were similar to the absorption rates in the small intestines of rats fed diets containing soluble Ca sources. These results show the following: (a) In rats fed 0.2% Ca diets containing soluble Ca salts, Ca is mostly absorbed in the small intestine, even in secondary phosphate intakes; (b) In contrast, in rats fed a 0.2% Ca diet containing an insoluble Ca salt (carbonate), Ca is not sufficiently absorbed in the small intestine. However, the large intestine compensates for the small intestinal Ca absorption decreased by dietary secondary phosphates.

Animals↗

Developmental changes in the inner surface structure of the bovine large intestine.

The developmental pattern of the bovine fetal large intestine was studied with particular reference to the appearance and decline of the intestinal villi during the fetal period. In the bovine large intestine, the first rudimentary villus and goblet cells were seen in the rectum in a fetus estimated to be 3 months old. By 5-6 months, the goblet cells, absorptive cells in the intestinal crypts, and vacuolated cells in the villi were present along all segments of the large intestine. By 8-9 months, the villi have disappeared from the colon and rectum, epithelial cells no longer contain vacuoles, and absorptive and goblet cell populations are emerging from the crypts. These histological results suggest that development in the bovine large intestine follows a recto-cecal gradient and the most distinct turning point during the fetal period is the first disappearance of fetal villi in the rectum of fetuses estimated to be 7 months old. After this stage, the mucous membrane of the colon and rectum matured rapidly before birth. In contrast, the cecum may seem to require further development in perinatal life.

Animals↗

INNERVATION OF THE LARGE INTESTINE OF THE TOAD (BUFO MARINUS).

The morphology, physiology and pharmacology of the innervation of the toad (Bufo marinus) large intestine have been studied. The large intestine can be divided into the regions colon, rectum and cloaca, on morphological grounds, but acts as a unit in response to nerve stimulation. Of the right and left nerves, each appears to supply the entire large intestine. Autonomic innervation of the large intestine of Bufo marinus is as follows: (1) The 9th and 10th spinal nerves (pelvic) contain predominantly excitatory preganglionic cholinergic fibres, but some inhibitory adrenergic fibres are also present in most preparations. (2) The splanchnic nerves contain inhibitory postganglionic adrenergic fibres from the 3rd to 5th sympathetic ganglia, and a small number of excitatory cholinergic fibres. The pathway of adrenergic inhibitory fibres to the large intestine alongside the posterior mesenteric artery as seen in mammals is rarely present in the toad. Several nonspecific actions of autonomic drugs on the large intestine are discussed. The functional organization of the autonomic innervation of the toad large intestine is similar to that in mammals, that is the large intestine is controlled by antagonistic cholinergic and adrenergic nerves. However, the separation of these two types of nerve fibres into anatomically distinct nerves does not appear to be as complete as in mammals. It is suggested that inhibitory autonomic control of the alimentary canal in vertebrates first appears in the hind-gut region.

Acetylcholine↗

Adrenergic receptor-mediated response of the rabbit small and large intestine.

Methoxamine, isoprenaline, salbutamol and dobutamine were used to inhibit the spontaneous contraction of various rabbit small and large intestinal sections. From the concentration of the drugs that produced a similar magnitude of inhibition of the spontaneous contraction, the following deductions were made: The small intestine compared to the large intestine responded more to methoxamine, indicating a predominant presence of alpha receptors in the small intestine. The reverse is true for isoprenaline, indicating a predominant presence of beta receptors in the large intestine. Salbutamol exerted a much greater effect on the large intestine than on the small intestine, indicating that the beta receptors of the large intestine are mainly of the beta2 type. The reverse is true for dobutamine, suggesting that the beta receptors of the small intestine may be mainly of the beta1 type. The second deduction agreed with the findings of Nakahata and co-workers who reported similar, though qualitative, findings in the rat and rabbit intestine. The third and fourth deductions are interesting in that the facts complement the century old acupuncture classification of paired meridian which grouped the lung and large intestine as a pair and the heart and small intestine as another pair. The lung has beta2 and the heart beta1 receptors.

Adrenergic alpha-Agonists↗

[Step-by-step mobilization with upwards transposition of the intestinal complex in total esophagoplasty using the right half of the large intestine].

An experience of performing total esophagoplasty with high esophagus strictures and 30 anatomo-experimental investigations on corpses enabled the authors to develop a new method of extraction of a transplant which was called a step-by-step mobilization with a displacement of the intestinal complex with fixation of the small intestine mesentery root to the posterior wall of the rectus abdominis sheath. The essence of the step-by-step mobilization with a displacement of the intestinal complex upwards is the following: if the first step of usual mobilization of the right half of the large intestine with a process of ileum proves to be not sufficient for making high anastomosis, the second step should be fulfilled consisting in mobilization of the small intestine mesenterium root which gives more opportunity to displace the large intestine transplant. If this measure still seems to be insufficient the third step is necessary such as a mobilization of the terminal portion of the duodenum. It allows the transplant to be made as high as the pharynx practically in all cases.

Adult↗

Rates of passage of digesta and water absorption along the larg intestines of sheep, cows and pigs.

In 5 cows, the mean length of the large intestine was only slightly greater than that of 21 sheep and 3 pigs. At about one-fifth of the way along the large intestine of the sheep and cows, corresponding to the end of the proximal colon and start of the spiral colon, there were marked reductions in the amount of digesta present and in the lumen diameter. In pigs these parameters decreased gradually along the large intestine. In all parts of the large intestine, the cows had more water in the digesta than did the sheep or the pigs. Nevertheless, the decrease in water content between the caecum and the rectum was similar for the cows and the sheep but less in the pigs. The rate of passage of digesta increased gradually along the large intestine of the pigs, but in the cows and sheep the rate was least in the caecum and proximal colon and greatest in the spiral colon. The total retention time for digesta in the large intestine was approximately 30, 20, and 9 h in the pigs, sheep, and cows respectively. The rate of water absorption from the large intestine was most rapid in the cows and slowest in the pigs. Differences in faecal water content between the species were not due to differences in retention times in the large intestine.

Animals↗

[Intestinal ultrasound in rare small and large intestinal diseases].

Intestinal ultrasonography is a meanwhile established and valid diagnostic method in inflammatory bowel disease, diverticulitis, and appendicitis. Little, however, is known about other more rare intestinal diseases. Serving as a tertiary referral center for a broad spectrum of intestinal diseases we therefore report some aspects of ultrasonography in patients with acute and chronic enteritis and colitis of different origin, e.g., bacterial and viral colitis, ileocecal tuberculosis, AIDS-related enteritis, neutropenic colitis, cystic fibrosis, celiac sprue, vasculitis, benign and malignant tumors of the intestine, amyloidosis, ischemic colitis, and radiogenic enteritis. Ultrasonography may display the transformation of the intestinal wall from normal to pathological states both in inflammatory and neoplastic disease. Besides demonstrating the transmural aspect of inflammation it also shows the mesenteric reaction as well as complications such as fistula, abscesses, stenosis, or ileus. Furthermore, in some diseases intestinal ultrasonography may serve as a diagnostic clue if typical patterns of the bowel wall and impaired peristalsis can be demonstrated. This may lead to an important reduction of invasive and expensive procedures. Ultrasonography is of definite help in the follow-up of inflammatory changes of the bowel wall and primarily diagnostic with respect of other entities (e.g., penicillin-induced segmental hemorrhagic colitis). A sonographic differential diagnosis of diseases of the bowel wall on a purely morphological basis, however, is difficult and rather the exception than the rule. The information gained by ultrasonography regarding intestinal disease, however, is as important and valid as e.g., in case of focal lesions of the liver.

Colitis↗

The distribution of polyps in the large intestine.

The distribution of polyps of the large intestine was investigated. Comparisons were made between results of autopsy studies and a clinical study consisting of 114 consecutively resected polyps. The shift from distal to proximal predominance of adenomas with increasing age from the 50 to the 80 year age group in autopsy studies, was in accordance with the high frequency of adenomas in the distal part of the large intestine in the prospective clinical study, mean 60 years of age. The present clinical study showed a high frequency of adenomas among men, whereas a tendency towards larger polyps and more polyps larger than 10 mm was seen for women. The present examination confirms the reported discrepancy between a high prevalence of adenomas compared to a much lower prevalence of cancer. Thus, the present results emphasize the need for further studies to gain information on risk factors in polyps or individuals predisposed for malignancy of the large intestine.

Aged↗

[Surgical treatment of large intestines obstruction caused by colorectal cancer].

Large intestinal obstruction like a life-threatening steatement is a subject of investigation in the present study. In such prospection are included 65 patients undergone surgery for large intestinal obstruction of cancer in period of seven years. Analyzed are after undertaken surgical procedures. It is clear that tendency of more security after surgery is concerned with the principles of radicalization after lower morbidity and mortality.

Colorectal Neoplasms↗

Human large intestinal epithelium: light microscopy, histochemistry, and ultrastructure.

Despite numerous reports of morphologic characteristics of premalignant and malignant large intestinal epithelium, the literature lacks comprehensive reports of the morphologic features of the epithelium of the normal large intestine, except of the rectum. Large intestinal epithelium from 41 persons was obtained, and samples from the ascending, transverse, descending, and rectosigmoid areas were studied by light microscopy, histochemical techniques, and transmission and scanning electron microscopy. The morphologic features and histochemical reactions of the various segments of the large intestine are different. Neutral mucopolysaccharide is predominant in the ascending colon, whereas the rectum has predominantly or exclusively acidic mucin. Only three basic epithelial cell phenotypes have been identified: undifferentiated cells, mucous cells, and endocrine cells. The columnar cells at the surface between the crypts appear to be a variant of mucous cells. Compared with other segments, the rectum shows an unusually high concentration of endocrine cells, positively correlating with the high incidence of carcinoid tumors in that segment of the large intestine. The mucous cells in all segments contain large mucous vacuoles and small apical vesicles. The apical vesicles show variable electron density, being most dense in the ascending colon and becoming progressively less dense at the transverse and descending colon and most electron-lucent in the sigmoid colon and rectum. Ultrastructurally, the mucin shows a variable degree of heterogeneity in the proximal segments. This study suggests that some of the previously described ultrastructural features of abnormal large-intestinal epithelium may be only the result of failure to compare the so-called abnormal cells with normal cells from the same region. Well-controlled studies of the abnormal epithelium of a particular segment of large intestine must include the normal epithelium from the identical segment as control in order to make interpretations accurate.

Adult↗

Serrated polyps of the large intestine.

Serrated polyps of the large intestine comprise a family of lesions bearing some histological similarities, including an overall serrated configuration caused at least in part by inhibition of apoptosis by mutations in one of two genes. Over the past decade, it has become apparent that these lesions can be subdivided by histological criteria into lesions with differing degrees of relationship to the development of carcinoma, including sporadic microsatellite instable (MSI) carcinomas and probably carcinomas demonstrating the CpG island methylator phenotype (CIMP), which includes both MSI and microsatellite stable tumors. These differing histological subtypes can in part predict some of the molecular features of these lesions, and the combination of histological and molecular features is beginning to give us better insight into the potential natural history and therefore management of these lesions. This review will present the histological classification of these lesions, relate that histological classification to molecular aspects of the lesions, and present recommendations for management.

Colorectal Neoplasms↗

[Preparation of the large intestine for the surgical treatment of intestinal obstruction].

Obstruction of the large intestine of tumorous origin was treated by the traditional methods in 191 patients: an emergency operation in peritonitis or nonoperative management of the obstruction by cleansing enema, purgatives, and infusion-transfusion therapy. In another group of 341 patients emergency colonoscopy and ultrasonic diagnosis were resorted to and the "obstruction index" (Deltz et al. 1989) was used for objectification of the indications for an emergency operation. The method of fractional oral treatment with 30% solution of polyethelyne oxide-400 and 1% chloramphenicol was applied in this group. Traditional treatment caused resolution of the obstruction in 22.8% of patients in the control and in 28.3% of patients in the experimental group. Postoperative mortality was 24.1% and 16.4%, respectively. The obstruction index allowed correct evaluation of the indications for operation in 97% of cases, the number of forced operation reduced from 52.2% to 14.1%.

Combined Modality Therapy↗