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Significant radiation exposure of the gastrointestinal tract produces early and late consequences. Therapeutic interventions are largely anecdotal, but there appear to be multiple mechanisms. The mechanism of injury and predisposing factors have been partially worked out in animal and cellular models. Clinical manifestations of chronic radiation enteritis vary and can be vague and difficult to characterize. Surgical intervention is required in 30% of patients with chronic radiation injury. A structured approach to assessing patients with GI symptoms after radiotherapy is useful as the therapeutic modality aimed at alleviating a specific symptom will clearly depend on the underlying pathology. Important information to gather at the time of presentation includes the history of the primary neoplasm, surgery performed, as well as an understanding of the duration and location of radiotherapy treatment, dosing regimen, target fields, and complications during treatment. Surgery may alleviate symptoms but is of greater risk than procedures on normal tissues.

Blood flow through healthy human vessels releases NO to produce vasodilation, whereas in patients with coronary artery disease (CAD), the mediator of dilation transitions to mitochondria-derived hydrogen peroxide ( mt H 2 O 2 ). Excessive mt H 2 O 2 production contributes to a proatherosclerotic vascular milieu. Loss of PGC-1α (peroxisome proliferator–activated receptor γ coactivator 1α) is implicated in the pathogenesis of CAD. We hypothesized that PGC-1α suppresses mt H 2 O 2 production to reestablish NO-mediated dilation in isolated vessels from patients with CAD. Isolated human adipose arterioles were cannulated, and changes in lumen diameter in response to graded increases in flow were recorded in the presence of PEG (polyethylene glycol)–catalase (H 2 O 2 scavenger) or L-NAME ( N G -nitro- l -arginine methyl ester; NOS inhibitor). In contrast to the exclusively NO- or H 2 O 2 -mediated dilation seen in either non-CAD or CAD conditions, respectively, flow-mediated dilation in CAD vessels was sensitive to both L-NAME and PEG-catalase after PGC-1α upregulation using ZLN005 and α-lipoic acid. PGC-1α overexpression in CAD vessels protected against the vascular dysfunction induced by an acute increase in intraluminal pressure. In contrast, downregulation of PGC-1α in non-CAD vessels produces a CAD-like phenotype characterized by mt H 2 O 2 -mediated dilation (no contribution of NO). Loss of PGC-1α may contribute to the shift toward the mt H 2 O 2 -mediated dilation observed in vessels from subjects with CAD. Strategies to boost PGC-1α levels may provide a therapeutic option in patients with CAD by shifting away from mt H 2 O 2 -mediated dilation, increasing NO bioavailability, and reducing levels of mt H 2 O 2 . Furthermore, increased expression of PGC-1α allows for simultaneous contributions of both NO and H 2 O 2 to flow-mediated dilation.

Background Exogenous replacement of depleted enterocyte intestinal alkaline phosphatase (IAP) decreases intestinal injury in models of colitis. We determined whether radiation-induced intestinal injury could be mitigated by oral IAP supplementation and the impact on tissue-nonspecific AP. Methods WAG/RjjCmcr rats (n = 5 per group) received lower hemibody irradiation (13 Gy) followed by daily gavage with phosphate-buffered saline or IAP (40 U/kg/d) for 4 days. Real-time polymerase chain reaction, AP activity, and microbiota analysis were performed on intestine. Lipopolysaccharide and cytokine analysis was performed on serum. Data were expressed as a mean ± SEM with P greater than .05 considered significant. Results Intestine of irradiated animals demonstrates lower hemibody irradiation and is associated with upregulation of tissue-nonspecific AP, downregulation of IAP, decreased AP activity, and altered composition of the intestinal microbiome. Conclusions Supplemental IAP after radiation may be beneficial in mitigating intestinal radiation syndrome as evidenced by improved histologic injury, decreased acute intestinal inflammation, and normalization of intestinal microbiome.

Background and Aims Patients with Crohn’s disease (CD) may require small bowel resections. Unfortunately, some of these patients may develop post-operative small bowel obstructions (SBO). Many clinicians perceive ileal resections dramatically increase the risk of developing SBO in the future, but the incidence and risk factors to developing SBO are poorly described. The primary aim of this study is to document the incidence and factors associated with the development of SBO not related to recurrence of disease in CD patients that undergo ileal resection. We also sought to assess long-term outcomes of this complication. Methods We performed a retrospective cohort study including patients aged 18 years or older with CD, who have had ileocecal resection with ileocolonic anastomosis or segmental small bowel resection. Data abstracted included demographics, phenotype and therapies of CD, disease recurrence post-ileal resection and multiple surgical variables. The primary outcome was the development of SBO within 5 years post-surgery not including obstructions secondary to recurrence of CD. Results 92 total patients were included in the analysis. All had a colonoscopy within a year of the surgery. The mean Rutgeerts score was 0 (interquartile range [IQR] 0 to 2) and the mean short endoscopic score was 0 (IQR 0 to 4). The remainder of baseline characteristics are shown in Table 1. At 6 months, 1 year, and 5 years, the rate of SBO was 4/92 (4%), 6/92 (6.5%), and 15/92 (16%), respectively. Throughout follow-up, only 5 patients had an SBO attributed to intra-abdominal adhesions and only 2 patients required surgical lysis of adhesions. Patients that were found to have histologic inflammation in the margins of the resected bowel specimen had a significantly higher chance of developing an SBO within 5 years of the initial surgery (OR: 4.5 [95%CI: 1.3–15.3], p=0.02 - Table 2). Conversely, patients with either active endoscopic and/or radiologic inflammation on post surgical surveillance colonoscopy did not have a higher risk of developing an SBO within 5 years of the initial surgery (p=0.37). Finally the length of bowel resected at the index surgery was not associated with the development of an SBO (AUC: 0.62, p=0.18). Conclusions The incidence of SBO after ileal resection in CD is low and resolves with medical management on most cases. Inflammation in the margins of the resected bowel and previous bowel resections were associated with new SBO within 5 years. These results must take into account the study population were monitored and cannot be extrapolated to those patients that lost follow-up.

Aortic graft infections are a rare but devastating complication of aortic revascularization. Often infections occur due to contamination at the time of surgery. Iatrogenic misplacement of the limbs of an aortobifemoral graft is exceedingly rare, and principles of evaluation and treatment are not well defined. We report 2 cases of aortobifemoral bypass graft malposition through the colon. Case Report: Case 1 is a 54-year-old male who underwent aortobifemoral bypass grafting for acute limb ischemia. He had previously undergone a partial sigmoid colectomy for diverticulitis. Approximately 6 months after vascular surgery, he presented with an occult graft infection. Preoperative imaging and intraoperative findings were consistent with graft placement through the sigmoid colon. Case 2 is a 60-year-old male who underwent aortobifemoral bypass grafting due to a nonhealing wound after toe amputation. His postoperative course was complicated by pneumonia, bacteremia thought to be secondary to the pneumonia, general malaise, and persistent fevers. Approximately 10 weeks after the vascular surgery, he presented with imaging and intraoperative findings of graft malposition through the cecum. Conclusions: Aortic graft infection is usually caused by surgical contamination and presents as an indolent infection. Case 1 presented as such; Case 2 presented more acutely. Both grafts were iatrogenically misplaced through the colon at the index operation. The patients underwent extra-anatomic bypass and graft explantation and subsequently recovered.

Polyphenolic compounds (anthocyanins, flavonoid glycosides) in berries prevent the initiation, promotion, and progression of carcinogenesis in rat's digestive tract and esophagus, in part, via anti-inflammatory pathways. Angiogenesis has been implicated in the pathogenesis of chronic inflammation and tumorigenesis. In this study, we investigated the anti-inflammatory and anti-angiogenic effects of black raspberry extract (BRE) on two organ specific primary human intestinal microvascular endothelial cells, (HIMEC) and human esophageal microvascular endothelial cells (HEMEC), isolated from surgically resected human intestinal and donor discarded esophagus, respectively. HEMEC and HIMEC were stimulated with TNF-α/IL-1β with or without BRE. The anti-inflammatory effects of BRE were assessed based upon COX-2, ICAM-1 and VCAM-1 gene and protein expression, PGE2 production, NFκB p65 subunit nuclear translocation as well as endothelial cell-leukocyte adhesion. The anti-angiogenic effects of BRE were assessed on cell migration, proliferation and tube formation following VEGF stimulation as well as on activation of Akt, MAPK and JNK signaling pathways. BRE inhibited TNF-α/IL-1β-induced NFκB p65 nuclear translocation, PGE2 production, up-regulation of COX-2, ICAM-1 and VCAM-1 gene and protein expression and leukocyte binding in HEMEC but not in HIMEC. BRE attenuated VEGF-induced cell migration, proliferation and tube formation in both HEMEC and HIMEC. The anti-angiogenic effect of BRE is mediated by inhibition of Akt, MAPK and JNK phosphorylations. BRE exerted differential anti-inflammatory effects between HEMEC and HIMEC following TNF-α/IL-1β activation whereas demonstrated similar anti-angiogenic effects following VEGF stimulation in both cell lines. These findings may provide more insight into the anti-tumorigenic capacities of BRE in human disease and cancer.

Inflammatory bowel disease (IBD) has a bimodal distribution with approximately 15 % of patients manifesting after age 65. Previous reports suggest an increased risk of surgical complications in the elderly.To compare surgical outcomes in elderly IBD patients (≥ 65 years at the time of surgery) to matched younger IBD cohorts.This was a retrospective cohort study at a single academic center of patients who underwent surgery for IBD. Forty-two elderly patients (≥ 65 years) were matched at least 1:1 (median 1:5) to patients in each of three control groups [18-35 years (n = 71); 36-49 years (n = 62); 50-64 years (n = 58)] according to gender, disease type/location, and type of surgery. Postoperative complications were compared. Patient characteristics were used in multivariate risk models. Analysis was performed using ordinary logistic regression.Twenty ileal or ileocolonic resections, 12 partial or total colectomies, four stricturoplasties, and six laparoscopic partial or total colectomies were performed in the elderly group. The post-operative complication rate was not statistically different between the elderly and younger cohorts (38 % vs. 39 % vs. 40 % vs. 48 % in the 18-35, 36-49, 50-64, and ≥ 65 years groups, respectively, p = 0.26). The only significant risk factors for complication were Charlson comorbidity index (p = 0.0002), preoperative hemoglobin (p = 0.0065), total parenteral nutrition use (p = 0.024), and failed medical therapy (as the indication for surgery) (p =0.0001).The surgical complication rate among elderly and younger IBD patients was similar. Advanced age by itself should not be considered a risk factor for adverse operative outcome.

To elucidate the signaling mechanisms involved in the protective effect of EUK-207 against irradiation-induced cellular damage and apoptosis in human intestinal microvasculature endothelial cells (HIMEC).HIMECs were irradiated and treated with EUK-207. Using hydroethidine and DCF-DA fluorescent probe the intracellular superoxide and reactive oxygen species (ROS) were determined. By real-time PCR and western blotting caspase-3, Bcl2 and Bax genes and proteins were analyzed. Proliferation was determined by [(3)H]-thymidine uptake. Immunofluorescence staining was used for translocation of p65 NFκB subunit.Irradiation increased ROS production, apoptosis, Bax, Caspase3 and NFkB activity in HIMEC and inhibited cell survival/growth/proliferation. EUK-207 restored the endothelial functions, markedly inhibited the ROS, up-regulated the Bcl2 and down-regulated Bax and prevented NFκB caspase 3 activity in HIMEC.HIMEC provide a novel model to define the effect of irradiation induced endothelial dysfunction. Our findings suggest that EUK-207 effectively inhibits the damaging effect of irradiation.

Background Radiation increases the frequency of small intestinal and colonic giant migrating contractions (GMCs). These contractions contribute to the diarrhea and cramping after radiation therapy and are coordinated with one another across the ileocolonic (IC) junction. Methods We investigated the coordination of contractile activity between the small intestine, cecum and colon in five canines following circumferential myotomy on the ileum at the IC junction and compared it to intact animals. Studies were performed before and during a radiation schedule. Key Results Myotomy increased the frequency of small intestinal GMCs prior to irradiation. In intact animals, the duration and amplitude of cecal GMCs decreased when multiple contractions occurred in rapid succession. This is in contrast to small intestinal and colonic GMCs and suggests a different mechanism of propagation for GMCs within the cecum. Ileal myotomy dramatically decreased the frequency of propagating radiation-induced colonic GMCs. The total number of colonic GMCs was not altered. Colonic contractile activity was disrupted in intact animals during irradiation. However, after ileal myotomy, irradiation did not affect the pattern of colonic contractile states. Diarrhea in irradiated animals with myotomy started earlier than intact animals. This may be related to the frequency of small intestinal GMCs. Conclusions & Inferences Our findings suggest importance of the enteric neural connections at the IC region to contractile disorders of both the small and large intestine. The anatomic relationship between the canine IC junction is similar to the human ileo-appendiceal-colonic region and surgical manipulations of this area may likewise affect human contractile activity.

Functional symptoms are common in patients with inflammatory bowel disease (IBD). The autonomic nervous system has been proposed to be involved in the pathogenesis of IBD. Autonomic dysfunction (AD) is associated with systemic manifestations and altered gut motility that may contributed to functional symptoms. Aim: To examine the impact of clinically manifest AD on patients with IBD. Methods: This was a retrospective case-control study from a single tertiary referral IBD center. The cases comprised 43 IBD patients with AD diagnosed using a standardized battery of tests. Three disease-matched controls were selected for each case. We performed multivariate regression to compare health-related quality of life (SIBDQ), disease activity scores, and healthcare utilization. Results: Female sex (83.7% vs. 53.5%, P < 0.001) and psychiatric comorbidity (41.9% vs. 10.9%, P < 0.001) were more common among IBD patients with AD than IBD controls. Small bowel transit times were significantly longer in cases (92.7 min) compared with controls (62.9 min, P = 0.02). On multivariate analysis, AD was associated with a 7-point lower adjusted SIBDQ score compared with IBD controls [odds ratio (OR) - 7.50; 95% confidence interval (CI), - 12.0- - 3.03]. AD was also significantly associated with having more than 3 annual gastroenterology office visits (OR 2.84; 95% CI, 1.09-7.35), and 1 or more IBD-related medical hospitalizations (OR 2.49; 95% CI, 1.09-5.71). Conclusions: Clinically manifest AD is associated with lower quality of life and higher healthcare utilization in IBD patients. They may represent a cohort at risk for worse outcomes.

Endothelial activation and surface expression of cell adhesion molecules (CAMs) is critical for binding and recruitment of circulating leukocytes in tissues during the inflammatory response. Endothelial CAM expression plays a critical role in the intestinal microvasculature in inflammatory bowel disease (IBD), as blockade of leukocyte α4-integrin binding by gut endothelial CAM ligands has therapeutic benefit in IBD. Mechanisms underlying expression of vascular cell adhesion molecule (VCAM)-1, a ligand for α4-integrin in primary cultures of human intestinal microvascular endothelial cells (HIMEC) has not been defined. We investigated the effect of curcumin, phosphatidylinositol 3-kinase (PI 3-kinase)/protein kinase B (Akt), and mitogen-activated protein kinase (MAPK) inhibitors on VCAM-1 expression and function in HIMEC. CAM expression was assessed and HIMEC-leukocyte adhesion was visualized under static and flow conditions. Western blotting and in vitro kinase assays were used to assess Akt and MAPK activation. Nuclear factor-κB (NF-κB) activation and nuclear translocation of its p65 subunit were determined. Tumor necrosis factor (TNF)-α/lipopolysaccharide (LPS)-induced VCAM-1 expression in HIMEC was suppressed by Akt small-interfering RNA, curcumin, and inhibitors of NF-κB (SN-50), p38 MAPK (SB-203580) and PI 3-kinase/Akt (LY-294002). VCAM-1 induction was partially suppressed by p44/42 MAPK (PD-098059) but unaffected by c-Jun NH2-terminal kinase (SP-600125) inhibition. Curcumin inhibited Akt/MAPK/NF-κB activity and prevented nuclear translocation of the p65 NF-κB subunit following TNF-α/LPS. At physiological shear stress, curcumin attenuated leukocyte adhesion to TNF-α/LPS-activated HIMEC monolayers. In conclusion, curcumin inhibited the expression of VCAM-1 in HIMECs through blockade of Akt, p38 MAPK, and NF-κB. Curcumin may represent a novel therapeutic agent targeting endothelial activation in IBD.

Background: Patients who require hospitalization for the management of ulcerative colitis (UC) may represent a subset with severe disease. These patients may be more likely to require future colectomy. There are limited data examining whether medical hospitalization is predictive of subsequent colectomy. Methods: This was a retrospective case–control study utilizing the inflammatory bowel disease center database at our academic referral center. Cases comprised UC patients who underwent colectomy for disease refractory to medical management. The control population was comprised of all patients with UC who had not undergone colectomy. Multivariate logistic regression was used to identify independent predictors of requiring colectomy. Results: There were a total of 246 UC patients included in our study, with 103 being hospitalized sometime in their disease course (41.9%). A total of 27 patients underwent colectomy (11%). Colectomy patients were significantly more likely to have been on infliximab therapy (51.8% versus 22.4%, P = 0.001) but no more likely to have been on immunomodulator therapy (74.1% versus 59.4%, P = 0.14). Patients who required medical hospitalization for UC were more likely to require future colectomy (20.4% versus 4.2%, P < 0.001) than those who had not required hospitalization. On multivariate analysis, requiring medical hospitalization for management of UC (odds ratio [OR] 5.37, 95% confidence interval [CI] 2.00–14.46) and ever requiring infliximab therapy (OR 3.12, 95% CI 1.21–8.07) were independent predictors of colectomy. Conclusions: Requiring medical hospitalization for the management of disease activity in UC is an independent predictor of the need for colectomy. Future studies will determine whether aggressive medical management may modify the need for colectomy in this cohort. (Inflamm Bowel Dis 2008)

Background: There is no standard approach for the medical management of Crohn's disease (CD) during pregnancy and there is limited data regarding safety and efficacy of the treatments. Budesonide (Entocort® EC, AstraZeneca) is an enteric coated locally acting glucocorticoid preparation whose pH- and time-dependent coating enables its release into the ileum and ascending colon for the treatment of mild to moderate Crohn's disease. There is no available data on the safety of using oral budesonide in pregnant patients. Methods: We reviewed our Inflammatory Bowel Disease (IBD) center database to identify patients with CD who received treatment with budesonide for induction and/or maintenance of remission during pregnancy and describe the maternal and fetal outcomes in a series of eight mothers and their babies. Results: The mean age of the patients was 27.7 years. All patients had small bowel involvement with their CD. The disease pattern was stricturing in 6 patients, fistulizing in 1 and inflammatory in 1 patient. Budesonide was used at the 6 mg/day dose in 6 patients and 9 mg/day dose in 2 patients. The average treatment duration ranges from 1-8 months. There were no cases of maternal adrenal suppression, glucose intolerance, ocular side effects, hypertension or fetal congenital abnormalities. Conclusion: Budesonide may be a safe option for treatment of CD during pregnancy. (Inflamm Bowel Dis 2008)

Background: Angiogenesis, the growth of new blood vessels, is a critical homeostatic mechanism which regulates vascular populations in response to physiological requirements and pathophysiological demand, including chronic inflammation and cancer. The importance of angiogenesis in gastrointestinal chronic inflammation and cancer has been defined, as antiangiogenic therapy has demonstrated benefit in models of inflammatory bowel disease and colon cancer treatment. Curcumin is a natural product undergoing evaluation for the treatment of chronic inflammation, including inflammatory bowel disease (IBD). The effect of curcumin on human intestinal angiogenesis is not defined. Methods: The antiangiogenic effect of curcumin on in vitro angiogenesis was examined using primary cultures of human intestinal microvascular endothelial cells (HIMECs), stimulated with vascular endothelial growth factor (VEGF). Results: Curcumin inhibited proliferation, cell migration and tube formation in HIMECs induced by VEGF. Activation of HIMECs by VEGF resulted in enhanced expression of cyclo-oxygenase-2 (COX-2) mRNA, protein and prostaglandin E2 (PGE2) production. Pretreatment of HIMECs with 10 μM curcumin as well as 1 μM NS398, a selective inhibitor of COX-2, resulted in inhibition of COX-2 at the mRNA and protein level and PGE2 production. Similarly COX-2 expression in HIMECs was significantly inhibited by Jun N-terminal kinase (JNK; SP600125) and p38 mitogen-activated protein kinase (MAPK; SB203580) inhibitors and was reduced by p44/42 MAPK inhibitor (PD098059). Conclusions: Taken together, these data demonstrate an important role for COX-2 in the regulation of angiogenesis in HIMECs via MAPKs. Moreover, curcumin inhibits microvascular endothelial cell angiogenesis through inhibition of COX-2 expression and PGE2 production, suggesting that this natural product possesses antiangiogenic properties, which warrants further investigation as adjuvant treatment of IBD and cancer.

The objective of this study was to determine the effect of daily administration of loperamide on gastrointestinal myoelectric activity. Six dogs were randomly administered three regimens–placebo, low dose loperamide (0.10–0.15 mg/kg/day, p.o.), and high dose loperamide (0.30–0.36 mg/kg/day, p.o.)–for one week each. Using surgically implanted bipolar electrodes, gastrointestinal myoelectric activity was recorded on at least 2 fed and 2 fasted experimental days for each regimen. In the fasted state, low dose loperamide decreased MMC cycle length, initiated intestinal amyogenesia in 40% of experiments, but did not induce vomiting. High-dose loperamide in the fasted state did not change MMC cycle length, but induced vomiting in 50% of experiments and initiated intestinal amyogenesia in 43% of experiments. The rate of occurrence of the myoelectric carrelates of giant migrating contractions (GMCs) and retrograde giant contractions (RGCs) increased with loperamide administration at both doses, as did the rate of occurrence of fed state MMCs. We conclude that daily oral administration of loperamide results in: (1) a dose-dependent effect on MMC cycle length; (2) intestinal amyogenesia; (3) an increase in frequency of vomiting at higher doses; and (4) an increase in incidence of GMCs and RGCs.

OBJECTIVE: Crohn's disease (CD) frequently presents during early adulthood, a peak time of work productivity. There are limited data from the United States on work disability from CD. We performed this study to identify clinical factors associated with permanent work disability in a CD tertiary referral cohort. METHODS: Cases were identified as patients who received permanent work disability compensation from the social security administration (SSA) related to CD. Four control patients who were not receiving work disability were selected for each case. Multivariate logistic regression was performed to identify characteristics that were independently associated with work disability. RESULTS: A total of 737 patients with CD were seen in our center, and 185 CD patients were included in our study (37 disability cases, 148 controls). On multivariate analysis, an SIBDQ score

Azathioprine and 6-mercaptopurine (6-MP) are effective in inflammatory bowel disease (IBD). However, between 10% and 29% of patients treated with these drugs are forced to stop therapy due to side effects. Pulmonary toxicity due to azathioprine/6-MP has been reported infrequently. We describe 3 patients who developed severe, noninfectious pulmonary toxicity within 1 month after the initiation of azathioprine or 6-MP for the treatment of IBD colitis (2 Crohn's disease and 1 ulcerative colitis). All patients presented with dyspnea, cough, and fever after initiation of azathioprine/6-MP. Evaluation for infectious etiologies, including bronchoscopy (3/3 patients) and open-lung biopsy (2/3 patients) was negative. Histopathologic examination of the lung biopsies revealed bronchiolitis obliterans organizing pneumonia in one, and usual interstitial pneumonitis in another patient. Cessation of purine analog therapy resulted in clinical improvement in all 3 cases. Azathioprine/6-MP-related pulmonary toxicity is a rare but serious side effect, and it is important for clinicians to have a high index of suspicion for this adverse reaction which occurs within 1 month after initiation of treatment for IBD.

The mechanism underlying the progression of normal esophageal mucosa to esophageal adenocarcinoma remains elusive. WNT5A is a noncanonical WNT, which mainly functions via the receptor tyrosine kinase-like orphan receptor 2 (ROR2), and has an unclear role in carcinogenesis. In this study, we aimed to determine the role of WNT5A/ROR2 signaling in esophageal adenocarcinoma. Analysis of WNT5A and ROR2 expression patterns in healthy controls, Barrett and esophageal adenocarcinoma patients' esophageal clinical specimens as well as in various esophageal cell lines demonstrated a ROR2 overexpression in esophageal adenocarcinoma tissues compared with Barrett and healthy mucosa, whereas WNT5A expression was found significantly downregulated toward esophageal adenocarcinoma formation. Treatment of esophageal adenocarcinoma OE33 cells with human recombinant WNT5A (rhWNT5A) significantly suppressed proliferation, survival, and migration in a dose-dependent fashion. rhWNT5A was found to inhibit TOPflash activity in ROR2 wild-type cells, whereas increased TOPflash activity in ROR2-knockdown OE33 cells. In addition, ROR2 knockdown alone abolished cell proliferation and weakened the migration properties of OE33 cells. These findings support an early dysregulation of the noncanonical WNT5A/ROR2 pathway in the pathogenesis of esophageal adenocarcinoma, with the loss of WNT5A expression together with the ROR2 overexpression to be consistent with tumor promotion. Implications: The dysregulation of WNT5A/ROR2 noncanonical WNT signaling in Barrett-associated esophageal adenocarcinoma introduces possible prognostic markers and novel targets for tailored therapy of this malignancy. Mol Cancer Res; 14(7); 647–59. ©2016 AACR.

Objective— Endothelium-dependent dilation to acetylcholine (Ach) is reduced in mucosal arterioles from patients with inflammatory bowel disease (IBD). The contributions of both nitric oxide (NO) and endothelial-derived hyperpolarizing factor (EDHF) are decreased. We hypothesized that the remaining dilation results from products of cyclooxygenase. Methods and Results— High-performance liquid chromatography (HPLC) was used to isolate eicosanoid vasodilator products and videomicroscopy was used to examine vasomotor responses in human mucosal arterioles from subjects with or without IBD undergoing bowel resection surgeries. In subjects without IBD, Ach constricted (−52%±10%) arterioles devoid of endothelium. Indomethacin (INDO) (cyclooxygenase inhibitor) had no effect. In contrast, Ach dose-dependently dilated both intact and endothelial denuded arterioles from patients with IBD. The dilation was converted to constriction by INDO (−54%±9%; P 2 receptor antagonist). Only in arterioles from subjects with IBD did Ach produce an arachidonic acid metabolite that comigrated on HPLC with PG D 2 (PGD 2 ). Exogenous PGD 2 dilated (max=66%±4%) IBD arterioles. Conclusion— In arterioles from IBD patients, Ach-mediated dilation shifts from endothelial production of NO and EDHF to nonendothelial generation of a PG, likely PGD 2 . This is a novel dilator mechanism arising from nonendothelial vascular tissue that compensates for loss of endothelium-dependent dilation. PGD 2 appears to be important in regulating mucosal blood flow in patients with IBD, implicating potentially detrimental effects from nonsteroidal antiinflammatory drugs.

Infected pelvic fluid collections are relatively common particularly after abdominal or pelvic surgery or in patients suffering from benign intestinal disease such as diverticulitis, appendicitis, or Crohn's disease. Historically the treatment of pelvic abscess has been either laparotomy with lavage or blind surgical incision and drainage through the rectal or vaginal wall. More recently, computed tomography and ultrasound-guided percutaneous drainage has become the procedure of choice, when feasible, for the treatment of pelvic abscess. However, many deep pelvic collections are not amenable to percutaneous technique. Transrectal or transvaginal ultrasound-guided abscess drainage is a safe and effective method used in the treatment of deep pelvic abscesses. The purpose of this article is to review the techniques, patient selection, pre- and post-procedural care, and monitoring aspects of transrectal or transvaginal ultrasound-guided drainage.

Radiation therapy of abdominal and pelvic solid tumours results in late intestinal toxicity of a severe nature in approximately 5% of cases. These manifestations may include ischaemia and stricture formation, which may present as "webs". These webs are likely to play a role in the pathogenesis of recurrent bowel obstruction. The mechanisms of microvascular injury to the bowel in the setting of radiation have not been defined. We hypothesised that microvascular dysfunction with impaired vasodilation to acetylcholine (Ach) would be an acquired pathophysiological abnormality in radiation and "web" formation.A 40 year old patient treated with radiation, two years previously, for an anal squamous cell cancer presented with recurrent small bowel obstruction. "Webs" in the distal ileum were detected using wireless capsule endoscopy, after small bowel barium radiographs failed to demonstrate a lesion. Following resection, freshly isolated 50-150 mum diameter arterioles from the "web" and adjacent normal calibre bowel were analysed with histology and microvessel physiological studies.After constriction (30-50%) with endothelin, dilation to graded doses of Ach (10(-9)-10(-4) M) was observed in vessels dissected from the stricture and the adjacent normal calibre area. Ach dilation was reduced in vessels from "web" (mean diameter 7 (2)%; n = 3, p0.01) compared with the adjacent unaffected bowel (mean diameter 85 (5)%). Dihydroethidine and dichlorofluorescein diacetate intravital staining demonstrated increased reactive oxygen species production in microvessels from "web" compared with adjacent normal calibre bowel. Histology from the strictured bowel demonstrated narrowing of the arterial lumen due to intimal and muscularis propria fibrosis, with endothelial preservation.External radiation is associated with acquired microvascular endothelial dysfunction and "web" formation in the small bowel.

Background Carbon dioxide is the preferred insufflating gas for laparoscopy because of greater safety in the event of intravenous embolism, but it causes abdominal and referred pain. Acidification of the peritoneum by carbonic acid may be the major cause of pain from carbon dioxide insufflation. Carbonic anhydrase is an enzyme that increases the rate of carbonic acid formation from carbon dioxide. Because acetazolamide inhibits carbonic anhydrase, the authors hypothesized that the pain caused by carbon dioxide insufflation may be decreased by the administration of acetazolamide. Methods A prospective, randomized, double-blind study of 38 patients undergoing laparoscopic surgery during general anesthesia was performed. Acetazolamide (5 mg/kg) or a saline placebo was administered intravenously during surgery. Pain was rated on a visual analog scale (0-10) at four times: when first awake, at discharge from the recovery room, when discharged from the hospital, and on the day after surgery. The site and quality of pain were recorded, as were medications and side effects. Results Initial referred pain scores were lower after acetazolamide (1.00 +/- 1.98; n = 18) than after placebo (3.40 +/- 3.48; n = 20; P = 0.014), and 78% of patients in the acetazolamide group had no referred pain; however, only 45% patients in the placebo group had no referred pain. Incisional pain scores were not statistically different, and referred pain scores were similar at later times. Conclusions Acetazolamide reduces referred but not incisional pain after laparoscopic surgical procedures. The duration of pain reduction is limited to the immediate postsurgical period.

Background Medical management of moderate to severe Crohn's disease (CD) using immunomodulator agents has not eliminated surgical treatment of disease complications. The effect of improved medical treatment on perioperative CD surgical outcome is not known. We analyzed the impact of immunomodulator therapy on the rate of intraabdominal septic complications (IASC) in CD patients undergoing bowel reanastomosis or strictureplasty. Methods Surgical outcome was reviewed in 100 consecutive CD patients who underwent segmental resection with primary anastomosis or strictureplasty between 1998 and 2002. Multivariate analysis was performed to determine the effect of immunomodulator therapy on rate of IASC (intraabdominal abscess, anastomotic leak, or enterocutaneous fistulae). Immunomodulator agents included azathioprine, 6-MP, methotrexate, and infliximab. Results IASC developed in 11 of 100 (11%) operations. Immunomodulator use was associated with fewer IASC (4/72 procedures; 5.6%), compared with 7/28 (25%) cases with patients not on therapy (P

Inflammatory bowel disease (IBD; i.e., Crohn's disease, ulcerative colitis) is characterized by refractory inflammatory ulceration and damage to the intestine. Mechanisms underlying impaired healing are not defined. Because microvascular dysfunction resulting in diminished vasodilatory capacity and tissue hypoperfusion is associated with impaired wound healing, we hypothesized that microvascular dysfunction may also occur in chronic IBD.Intact submucosal arterioles from control, involved, and uninvolved IBD specimens were assessed using in vitro videomicroscopy to assess endothelium-dependent vasodilation in response to acetylcholine (Ach) and fluorescence microscopy to detect oxyradicals.Normal microvessels dilated in a dose-dependent and endothelium-dependent manner to Ach (maximum, 82% +/- 2%; n = 34). Inhibition of nitric oxide synthase with N(G)-nitro-L-arginine methyl ester (L-NAME) reduced maximal dilation to 54% +/- 6% (P0.05, n = 7), and further reduction was observed after inhibiting cyclooxygenase (indomethacin; 23% +/- 10%, n = 6). Chronically inflamed IBD microvessels showed significantly reduced Ach-induced vasodilation (maximum, 15% +/- 2%; n = 33), with no effect of L-NAME. Indomethacin eliminated the remaining Ach-induced vasodilation, resulting in frank vasoconstriction (-54% +/- 9%, n = 6). Uninvolved IBD gut vessels and non-IBD inflammatory controls responded in a fashion similar to normal vessels. IBD-involved microvessels generated significantly higher levels of reactive oxygen species compared with control and uninvolved IBD vessels (P0.01).Human intestinal microvessels from chronically inflamed IBD show microvascular endothelial dysfunction, characterized by loss of NO-dependent dilation that may contribute to reduced perfusion, poor wound healing, and maintenance of chronic inflammation.

Angiogenesis plays a critical role in metastasis and tumor growth. Human tumors, including colorectal adenocarcinoma, secrete angiogenic factors, inducing proliferation and chemotaxis of microvascular endothelial cells, eventually leading to tumor neovascularization. The chemokine interleukin 8 (IL-8; CXCL8) exerts potent angiogenic properties on endothelial cells through interaction with its cognate receptors CXCR1 and CXCR2. As CXCR1 and CXCR2 expression is differentially regulated in tissue-specific endothelial cells and effects of IL-8 on intestinal endothelial cells are not defined, we characterized the potential IL-8-induced angiogenic mechanisms in primary cultures of human intestinal microvascular endothelial cells (HIMEC) and IL-8 receptor expression in human intestinal microvessels. CXCR1 and CXCR2 expression on HIMEC were defined using reverse transcriptase-PCR, immunohistochemistry, flow cytometry, and Western blot analysis. IL-8-induced downstream signaling events were assessed using immunoblot analysis and immunofluorescence. The angiogenic effects of IL-8 on HIMEC were determined using proliferation and chemotaxis assays. HIMEC responded to IL-8 with rapid stress fiber assembly, chemotaxis, enhanced proliferation, and phosphorylation of extracellular signal-regulated protein kinase 1/2 (ERK 1/2). HIMEC express CXCR2, but not CXCR1. Neutralizing antibodies to CXCR2 diminished IL-8-induced chemotaxis and stress fiber assembly. Specific inhibitors of ERK 1/2 and phosphoinositide 3-kinase abrogated endothelial tube formation and IL-8-induced chemotaxis in HIMEC. IL-8 elicits angiogenic responses in microvascular endothelial cells isolated from human intestine by engaging CXCR2. We confirmed tissue expression of CXCR2 in human intestinal microvessels. Supported by the notion that malignant colonic epithelial cells overexpress IL-8, CXCR2 blockade may be a novel target for anti-angiogenic therapy in colorectal adenocarcinoma.

About 75 % of the patients with Crohn’s disease will require surgery at one time or another during the course of their disease. Surgery does not cure Crohn’s disease but rather treats the complications of the disease. Medical management is required to treat the actual disease process and is necessary for most patients to remain healthy after their surgery. The complications of Crohn’s disease that can be addressed by surgery include: bleeding, obstruction (blockage of the bowel), perforation (hole in the bowel wall), abscess (pus pocket), fistualization (abnormal connection between bowels), incontinence (loss of stool), inability to manage the disease medically, and malignancy (cancer).

The management of fistulas largely depends on the extent of the fistula and the degree of inflammation and infection present. If a large infected fluid collection is present, this is usually drained in the operating room prior to any other intervention. Treatment with antibiotics is also common. At times, a drain called a seton is placed to keep the fluid collection from reforming. It is also important to assess both the internal and external opening of the fistula and the path of the tract between them in order to determine the best treatment option. This may be accomplished by an exam under anesthesia or other radiologic studies such as an MRI or an ultrasound study. The degree of inflammation from Crohn’s disease present in the rectum and anus must also be assessed. If inflammation is present, medical therapy is utilized first with the hopes of improving the degree of inflammation and promoting spontaneous closure of the fistula.

The calcineurin inhibitor cyclosporine A (CsA) modulates leukocyte cytokine production but may also effect nonimmune cells, including microvascular endothelial cells, which regulate the inflammatory process through leukocyte recruitment. We hypothesized that CsA would promote a proinflammatory phenotype in human intestinal microvascular endothelial cells (HIMEC), by inhibiting inducible nitric-oxide synthase (iNOS, NOS2)-derived NO, normally an important mechanism in limiting endothelial activation and leukocyte adhesion. Primary cultures of HIMEC were used to assess CsA effects on endothelial activation, leukocyte interaction, and the expression of iNOS as well as cell adhesion molecules. CsA significantly increased leukocyte binding to activated HIMEC, but paradoxically decreased endothelial expression of cell adhesion molecules (E-selectin, intercellular adhesion molecule 1, and vascular cell adhesion molecule-1). In contrast, CsA completely inhibited the expression of iNOS in tumor necrosis factor-α/lipopolysaccharide-activated HIMEC. CsA blocked p38 MAPK phosphorylation in activated HIMEC, a key pathway in iNOS expression, but failed to inhibit NFκB activation. These studies demonstrate that CsA exerts a proinflammatory effect on HIMEC by blocking iNOS expression. CsA exerts a proinflammatory effect on the microvascular endothelium, and this drug-induced endothelial dysfunction may help explain its lack of efficacy in the long-term treatment of chronically active inflammatory bowel disease.

We examined the influence of gender and climacteric status, two coronary risk factors, on bradykinin (BK)-induced dilation in adipose arterioles from men and women of different ages [premenopausal women (Pre-W), postmenopausal women (Post-W), and similar aged men (Y-M and O-M), respectively]. We examined the responses from both omental (more closely associated with coronary disease) and subcutaneous fat. Tissues were obtained at surgery and cannulated (60 mmHg) for measurement of internal diameter. In vessels from omental tissue, dilation to BK was more sensitive in Pre-W than other groups, whereas in vessels from subcutaneous tissue, sensitivity to BK was greater in both Pre-W and Post-W compared with Y-M and O-M. Maximal dilation was similar among groups. Indomethacin (Indo; 10−5 M) alone had no effect on dilation to BK in any groups, but Indo and N ω-nitro-l-arginine methyl ester (l-NAME; 10−4 M) reduced dilation to BK in Pre-W more than in Y-M. l-NAME increased dilation to BK in subcutaneous fat from Y-M but had no effect in Post-W and O-M. Indo- and l-NAME-resistant dilation in all vessels was markedly reduced by 30 mM KCl. There was no difference in sodium nitroprusside-induced dilation among groups. We conclude that gender and climacteric state contribute to mechanisms of microvascular regulation in humans. Functional vascular differences in visceral and subcutaneous fat may underlie the proposed differential influence of these tissues on cardiovascular risk.

BACKGROUND: Controversy exists regarding the influence of sentinel lymph node (SLN) mapping technique or patient variables on the success rate of SLN mapping. We undertook a prospective study in a single institution series to evaluate multiple variables that could adversely affect SLN identification rates. STUDY DESIGN: Data were collected on 174 patients who underwent 177 SLN mapping procedures followed by axillary dissection from October 1996 through January 2000. Patient demographics, body mass index (BMI), biopsy method, tumor size, palpability, and location were recorded. SLNs were identified by blue dye only (n = 31), Tc-99m sulfur colloid only (n = 34), or combined techniques (n = 112). Data were analyzed by logistic regression analysis and expressed as the probability of failure to map the SLN. RESULTS: SLNs were identified successfully in 150 of 177 procedures (85%) with a false negative rate of 3.7%. Mapping success reached 93% using combination blue dye and isotope. Variables found to adversely affect SLN mapping success and the odds ratio of failure (OR) included lower inner quadrant (LIQ) location (OR 35.6), blue dye only (OR 42.4), BMI > 30 and upper outer quadrant (UOQ) location (OR 14.6), and nonpalpable UIQ location (OR 25). LIQ location adversely affects mapping success independent of technique, tumor size, or obesity. Obesity and nonpalpability were adverse factors when tumors were located in the UOQ and UIQ, respectively. Age, biopsy technique, and tumor diameter did not affect SLN mapping success. CONCLUSIONS: SLN mapping success is influenced by technique and tumor location, with best results achieved using combined techniques and for lesions located in quadrants other than the LIQ. Obesity and tumor palpability influence success in the context of tumor location.

Endothelial-mesenchymal transition (EndoMT) has been recognized as a key determinant of tumor microenvironment in cancer progression and metastasis. Endothelial cells undergoing EndoMT lose their endothelial markers, acquire the mesenchymal phenotype, and become more invasive with increased migratory abilities. Early stages of esophageal adenocarcinoma (EAC) are characterized by strong microvasculature whose impact in tumor progression remains undefined. Our aim was to determine the role of EndoMT in EAC by investigating the impact of tumor cells on normal primary human esophageal microvascular endothelial cells (HEMEC). HEMEC were either cocultured with OE33 adenocarcinoma cells or treated with IL-1β and transforming growth factor-β2 (TGF-β2) for indicated periods and analyzed for EndoMT-associated changes by real-time PCR, Western blotting, immunofluorescence staining, and functional assays. Additionally, human EAC tissues were investigated for detection of EndoMT-like cells. Our results demonstrate an increased expression of mesenchymal markers [fibroblast-specific protein 1 (FSP1), collagen1α2, vimentin, α-smooth muscle actin (α-SMA), and Snail], decreased expression of endothelial markers [CD31, von Willebrand factor VIII (vWF), and VE-cadherin], and elevated migration ability in HEMEC following coculture with OE33 cells. The EndoMT-related changes were inhibited by IL-1β and TGF-β2 gene silencing in OE33 cells. Recombinant IL-1β and TGF-β2 induced EndoMT in HEMEC. Although the level of VEGF expression was elevated in EndoMT cells, the angiogenic property of these cells was diminished. In vivo, by immunostaining EndoMT-like cells were detected at the invasive front of EAC. Our findings underscore a significant role for EndoMT in EAC and provide new insights into the mechanisms and significance of EndoMT in the context of tumor progression.

Increased intraluminal pressure can reduce endothelial function in resistance arterioles; however, the mechanism of this impairment is unknown. The purpose of this study was to determine the effect of local renin-angiotensin system inhibition on the pressure-induced blunting of endothelium-dependent vasodilation in human adipose arterioles. Arterioles (100–200 μm) were dissected from fresh adipose surgical specimens, cannulated onto glass micropipettes, pressurized to an intraluminal pressure of 60 mmHg, and constricted with endothelin-1. Vasodilation to ACh was assessed at 60 mmHg and again after a 30-min exposure to an intraluminal pressure of 150 mmHg. The vasodilator response to ACh was significantly reduced in vessels exposed to 150 mmHg. Exposure of the vessels to the superoxide scavenger polyethylene glycol-SOD (100 U/ml), the ANG II type 1 receptor antagonist losartan (10−6 mol/l), or the angiotensin-converting enzyme inhibitor captopril (10−5 mol/l) prevented the pressure-induced reduction in ACh-dependent vasodilation observed in untreated vessels. High intraluminal pressure had no effect on papaverine-induced vasodilation or ANG II sensitivity. Increased intraluminal pressure increased dihydroethidium fluorescence in cannulated vessels, which could be prevented by polyethylene glycol-SOD or losartan treatment and endothelial denudation. These data indicate that high intraluminal pressure can increase vascular superoxide and reduce nitric oxide-mediated vasodilation via activation of the vascular renin-angiotensin system. This study provides evidence showing that the local renin-angiotensin system in the human microvasculature may be pressure sensitive and contribute to endothelial dysfunction after acute bouts of hypertension.

Microvascular endothelial cells play a key role in inflammation by undergoing activation and recruiting circulating immune cells into tissues and foci of inflammation, an early and rate-limiting step in the inflammatory process. We have previously [Binion et al., Gastroenterology112:1898–1907, 1997] shown that human intestinal microvascular endothelial cells (HIMEC) isolated from surgically resected inflammatory bowel disease (IBD) patient tissue demonstrate significantly increased leukocyte binding in vitro compared to normal HIMEC. Our studies [Binion et al., Am. J. Physiol.275 (Gastrointest. Liver Physiol. 38):G592–G603, 1998] have also demonstrated that nitric oxide (NO) production by inducible nitric oxide synthase (iNOS) normally plays a key role in downregulating HIMEC activation and leukocyte adhesion. Using primary cultures of HIMEC derived from normal and IBD patient tissues, we sought to determine whether alterations in iNOS-derived NO production underlies leukocyte hyperadhesion in IBD. Both nonselective (NG-monomethyl- l -arginine) and specific (N-Iminoethyl- l -lysine) inhibitors of iNOS significantly increased leukocyte binding by normal HIMEC activated with cytokines and lipopolysaccharide (LPS), but had no effect on leukocyte adhesion by similarly activated IBD HIMEC. When compared to normal HIMEC, IBD endothelial cells had significantly decreased levels of iNOS mRNA, protein, and NO production following activation. Addition of exogenous NO by co-culture with normal HIMEC or by pharmacologic delivery with the long-acting NO donor detaNONOate restored a normal leukocyte binding pattern in the IBD HIMEC. These data suggest that loss of iNOS expression is a feature of chronically inflamed microvascular endothelial cells, which leads to enhanced leukocyte binding, potentially contributing to chronic, destructive inflammation in IBD.

Glutathione depletion has been described in tissues obtained from several chronic diseases. Increased free radical production by inflammatory cells occurs in inflammatory bowel disease. We hypothesized that this could induce depletion of gut antioxidants. In this study, we examined the potential relationship between chronic inflammation and colonic glutathione levels. Using a validated assay, glutathione levels were determined in the mucosal-submucosal layer and the muscularis externa layer in surgical colonic specimens from 26 patients with ulcerative colitis, 14 patients with Crohn's colitis, and 10 patients who underwent partial colectomy for non-obstructive neoplasia. Inflammation was graded histologically. Glutathione levels were decreased in the muscularis externa and in the mucosal-submucosal layers from both ulcerative colitis and Crohn's colitis (both p 0.05). This study provides evidence that chronic inflammatory disorders of the colon are associated with glutathione depletion. In ulcerative colitis, there was a relationship between the severity of inflammation and glutathione depletion. By contrast, this relationship was not significant in Crohn's colitis. The results suggest that there could be a primary defect in glutathione production in Crohn's colitis, or a difference in the relative levels of free radical production by inflammatory cells present in these two disorders of colonic inflammation.

Gastrointestinal (GI) surgery associated with resection or bypass can affect the absorption and kinetics of certain drugs. The goal of this article is 3-fold: (1) highlight the physiologic changes associated with selected GI surgeries (specifically gastric, small intestine, and colon), (2) review the implications for drug and nutrient absorption, and (3) suggest modifications of the pharmacologic agents, dosing regimens, and routes of delivery. Few large trials are available to use as references, but there is a wealth of individual reports and small series. Understanding the predictable challenges of drug administration in these patients will improve care.

Epidural abscess is a rare complication of fistulizing Crohn's disease (CD), potentially appearing as neurologic symptoms or back and leg pain. We report a case of a large epidural abscess resulting from uncontrolled fistulizing CD, which was rapidly defined using gadolinium-enhanced magnetic resonance imaging (MRI). Whenever caudal neurologic symptoms, back pain, and fever arise in CD patients, diagnostic MRI of the pelvis in addition to conventional computerized tomography should be considered to identify perirectal fistulization to the spine.

We investigated the neural mechanisms of control of giant migrating contractions (GMCs) in five conscious dogs. After control recordings, a Thiry-Vella loop was prepared from the middle segment, and the remaining two segments were reanastomosed. GMCs were stimulated by intravenous administration of fentanyl and erythromycin lactobionate, oral administration of loperamide and erythromycin stearate, and gastric or intraluminal administration of cider vinegar in the loop. In the intact state, the agents stimulated GMCs in all three segments, and they propagated uninterruptedly from the point of their origin to the terminal ileum. The propagation velocity of GMCs increased, whereas that of migrating motor complexes (MMCs) decreased distally. After Thiry-Vella loop formation, the agents stimulated GMCs independently in the three segments, and they propagated only to the end of the segment in which they started. In the intact small intestine, the GMCs produced ascending and descending inhibition of spontaneous phase II contractions but did not interrupt the caudad propagation of the ongoing MMC. After Thiry-Vella loop formation, the ascending inhibition was unaltered, but the descending inhibition occurred only in the segment containing the GMC. We conclude that the propagation of GMCs in the small intestine is controlled by the enteric nerves. The extrinsic nerves control the ascending inhibition produced by GMCs, whereas the enteric nerves control the descending inhibition.

The small intestine produces a number of different contractions in various spatial and temporal patterns that promote efficient digestion, absorption, and propulsion of ingested material. The small bowel also serves a protective role through the use of special situation contractions that rapidly propel enteric contents into the stomach or colon, from which they may be expelled. Contractile activity of the small intestine is coordinated by an interplay of myogenic, neural, and chemical controls.

The transcript size of VIP/PHM-27 mRNA (vasoactive intestinal peptide/peptide histidine methionine) and the relative distribution of VIP/PHM-27 gene expression in 10 normal human tissues was examined. After mRNA extraction from tissue, VIP/PHM-27 transcript size and relative abundance of mRNA was determined by Northern blot analysis and densitometry of the autoradiograms. VIP/PHM-27 mRNA was detectable in brain, pancreas, colon, ileum and striated muscle while no hybridization signal was observed in liver, kidney, lung, heart, prostate and placental tissue. VIP/PHM-27 transcript in human brain and gut was a single band of 1.7 kb; by contrast, a 7.0-kb transcript was detected in striated skeletal muscle. The highest relative levels of mRNA were observed in brain and pancreas.

Based upon previous morphologic studies, we hypothesized that the development of acquired megacolon was associated with abnormalities of enteric neurotransmitter concentrations and enzymatic activities. Specimens were obtained at surgery from patients with normal descending-sigmoid colon (n = 13) and patients with sigmoid megacolon (n = 6; defined by radiologic measurement). Radioimmunoassays were used to measure the non-adrenergic, non-cholinergic inhibitory neuropeptide, vasoactive intestinal peptide, and the non-adrenergic, non-cholinergic excitatory neuropeptide, substance P, while spectrophotometric assays were used to quantitate acetylcholinesterase activity and choline acetyltransferase activity. There were significantly decreased concentrations of vasoactive intestinal peptide and decreased acetylcholinesterase activity in muscularis externa from patients with acquired megacolon. In megacolon, vasoactive intestinal peptide-containing nerve fibers appeared to be diminished in circular and longitudinal smooth muscle, and immunostaining of nerve cell bodies in the plexus submucosus externus appeared diminished. These results suggest the hypothesis that production of vasoactive intestinal peptide is altered allowing secondary colonic hypertrophy to develop from prolonged cholinergic nerve-mediated contractions of circular smooth muscle. As a corollary to this hypothesis, colonic dilatation might result from prolonged contraction of longitudinal smooth muscle.

We investigated the role of nitric oxide (NO) in the regulation of migrating motor complex (MMC) cycling during the fasting state and its postprandial disruption. Intravenous infusion of Nohgr-nitro-l-arginine methyl ester (l-NAME) first produced a premature MMC and then disrupted MMC cycling for the rest of the day. The cycle length of the MMCs was significantly shorter than the control on the 2nd, 3rd, and 4th day after l-NAME infusion. The gastric cyclic motor activity (CMA) did not usually exhibit a premature cycle on the day of l-NAME infusion but was disrupted by l-NAME infusion; the duration of CMA disruption in the stomach was significantly longer than that of MMC disruption in the small intestine. Infusion of Nohgr-nitro-l-arginine (l-NNA) exhibited similar effects. The intravenous infusion of l-NAME also significantly shortened the duration of MMC disruption by a meal. l-Arginine alone had no significant effect on gastrointestinal motor activity during the fasting or the fed state, but when infused with l-NAME, it blocked the effects of NO synthase inhibition. Angiotensin II increased the mean arterial pressure to a level similar to that produced by l-NAME but had no significant effect on the fasting or the fed pattern of gastrointestinal motor activity. We conclude that NO containing nonadrenergic noncholinergic (NANC) neurons play a significant role in regulating MMC and CMA cycling during the fasting state and their disruption by a meal. However, NO may not be the only NANC neurotransmitter to inhibit contractions in the gut; phase I activity in the small intestine persisted during NO synthase inhibition by l-NAME or l-NNA. nonadrenergic noncholinergic neurons; cyclic motor activity: Nohgr-nitro-l-arginine methyl ester; Nohgr-nitro-l-arginine; vasoactive intestinal peptide; cholecystokinin Submitted on November 30, 1992 Accepted on June 3, 1993