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[Perforation of the sigmoid colon secondary to acetabular fracture].

Traumatic lesions of the colon associated with fracture of the acetabulum occurs in less than 2% of the cases. Direct perforation of the colon by a bony spike, which occurred in our patient, is even more exceptional. We were unable to find any other case reported in the literature. This case illustrates the importance of looking for intestinal lesions in all patients with pelvic injury presenting an unexplained infectious syndrome. Imaging provides clear evidence for avoiding late diagnosis and life-threatening situations.

Acetabulum↗

Carcinoma in situ spread to mucosa of sigmoid colon neobladder.

This is the first case of carcinoma in situ (CIS) of a transitional cell carcinoma that had spread into a neobladder constructed using a bowel segment associated with local recurrence at the ureteral-neobladder anastomosis. Considering that the CIS lesion was found in macroscopically intact epithelium remote from the main tumor, this strongly suggests that CIS could arise from solid tumor by implantation. Although some studies have reported secondary malignancy occurring in the neobladder, most have been adenocarcinoma that arose from the replaced bowel segment. To our knowledge, the present case is the first of widespread CIS of transitional cell carcinoma in an orthotopic neobladder.

Aged↗

The renin-angiotensin system in swine during hypovolaemic shock combined with low-flow ischaemia of the sigmoid colon.

Colonic ischaemia is a serious complication after aortic surgery, and is most frequent after repair of ruptured aortic aneurysms. It was felt that the increased risk of colonic ischaemia during shock might be the result of a local effect of the renin-angiotensin system in the splanchnic circulation, which is exacerbated by poor perfusion. In order to evaluate the activity of the renin-angiotensin system in the colonic circulation, a subtotal occlusion of the distal aorta was induced in nine pigs. A colonic flow reduction of 70% was created for 4 hours. In the experimental group (n = 6), induce hypovolaemic shock, 20 cm3/kg blood was sampled at 45 min before resuscitation was performed with 20 cm3/kg haemaccel. The sham group (n = 3) did not have hypovolaemic shock induced. Blood samples were taken for determinations of angiotensin II, haemoglobin and lactate. Blood gas was obtained from the pulmonary artery and the caudal mesenteric vein for blood gas analysis and lactate determinations. ANOVA and the Wilcoxon sum rank test were used for statistical analysis. There was a significant increase in angiotensin II after induction of ischaemia in both groups. The increase in angiotensin II in the splanchnic circulation was more prominent than the increase in the systemic circulation (P < 0.01). In the experimental group, there was a sustained increase in angiotensin II levels in the splanchnic circulation following shock and reperfusion (P < 0/01). The increase in lactate concentrations, which was significantly higher in the experimental group (P < 0.05), was evidence of intestinal ischaemia. There was a significant decline in cardiac output and blood pressure during the period of shock (P < 0.05). The combination of colonic ischaemia and hypovolaemic shock followed by reperfusion leads to an increase in angiotensin II activity. The increase of the local activity of the renin-angiotensin system in the splanchnic circulation is more prominent after ischaemia and reperfusion. This is probably caused by a selective response of the splanchnic vasculature to shock, ischaemia and reperfusion.

Animals↗

Endoluminal pulse oximetry of the sigmoid colon and the monitoring of the colonic circulation.

Colonic ischaemia is a frequently observed serious complication following abdominal aortic reconstruction. For adequate treatment of this disorder, early diagnosis and resection of the diseased colon is essential. The purpose of this study was to evaluate a new method, based on pulse oximetry, to detect colonic ischaemia at an early preclinical stage. During a 7-year period (1989-1995) colonoscopy and pulse oximetry were performed in all patients at risk of colonic ischaemia: complicated acute or elective aortic reconstructions, colostomies with superficial necrosis and in patients who underwent uncomplicated aortic reconstruction and non-ischaemic colonic problems (n = 90). The sensitivity, specificity and positive predictive values, and negative predictive value, were calculated. All patients, except four for whom an acute relaparotomy was necessary, subsequently underwent colonoscopy combined with endoluminal pulse oximetry. Of the 90 patients, 30 had colonic ischaemia according to endoscopy (n = 26) or relaparotomy (n = 4), and in 33 patients the absence of pulsatile signal was detected by means of pulse oximetry. Thus, in three patients, pulse oximetry was falsely positive for colonic ischaemia. The calculated sensitivity and specificity of pulse oximetry were 100 and 95%, respectively. In comparison to other methods used for early detection of colonic ischaemia, pulse oximetry appears to be a promising method for the evaluation and monitoring of colonic ischaemia because it is non-invasive and easy to apply with a high sensitivity and specificity.

Adult↗

Circular muscle contraction, messenger signalling and localization of binding sites for neurokinin A in human sigmoid colon.

1. Neurokinin (NK)A is the endogenous ligand for the tachykinin NK2 receptor. In the present study, tachykinins and selective receptor agonists were tested as contractile agonists in human colon circular muscle and [125I]-NKA was used to localize binding sites in human colon. 2. In strips of circular muscle, removal of mucosa and submucosa significantly (P < 0.05) increased the potency and the maximum response achieved by NKA. 3. The rank order of potency of tachykinin and selective receptor agonists in contracting circular muscle strips was NKA > or = [Lys5,MeLeu9,Nle10]NKA(4-10) > or = neuropeptide (NP)gamma > or = [betaAla8]NKA(4-10) >> NKB > substance P (SP) >> senktide approximate to [Pro9]SP. 4. Specific binding sites for [125I]-NKA were densely localized over circular muscle and muscularis mucosae. Weak specific binding was seen on longitudinal muscle and taenia coli, whereas no binding sites were seen on mucosa, ganglia or blood vessels. 5. In circular muscle, the selective NK2 receptor agonist [LysS,MeLeu9,Nle10]NKA(4-10) produced weak increases (maximum 37%) in inositol monophosphate formation with a pD2 of 6.8+/-0.51 (n = 3). Carbachol (100 micromol/L) was also a weak stimulant (maximum 45%). These agonists were over 10-fold more efficacious in stimulation of inositol monophosphate in rat urinary bladder. 6. In conclusion, [125I]-NKA binding sites localized on human colon circular muscle were characterized as NK2 receptors. Functionally, the tachykinin NK2 receptor is mediating circular smooth muscle contraction. Although the human NK2 receptor is coupled to the phosphatidylinositol pathway, other second messenger mechanisms may also operate in this tissue.

Aged↗