Is pyloric gland metaplasia in ileal pouch biopsies a marker for Crohn's disease?

BACKGROUND

Approximately 5-10 % of ulcerative colitis (UC) patients who undergo ileal pouch-anal anastomosis (IPAA) will develop postoperative complications such as refractory pouchitis or a change in diagnosis to Crohn's disease (CD). Serological markers and histologic aspects of the pouch such as pyloric gland metaplasia (PGM) have been associated with a risk for these complications.

METHODS

Twenty-eight IPAA patients with either CD of the pouch or chronic pouchitis (cases) and 36 IPAA controls who experienced a normal postoperative course were originally consented. Of these 64 subjects, 22 cases and 17 controls had histopathologic and serologic data available and were subsequently enrolled. Demographic and clinical data were entered into a database, blood analyzed for serological markers (Prometheus Labs, San Diego, CA) and biopsies of the pouch and the afferent limb reviewed by two GI pathologists.

RESULTS

Of the cases, 55 % (12/22) had evidence of PGM in their pouch and/or small bowel biopsies, as compared to 12 % (2/17) of the controls (p = 0.006). Of 13 subjects with CD, 77 % (10/13) were found to have PGM versus subjects with chronic pouchitis in which 22 % (2/9) were found to have PGM (p = 0.03). There was a trend of ASCA positivity (both IgG and IgA, p = 0.20) and of higher ASCA titer levels (p = 0.07) with postoperative complications.

CONCLUSION

This study suggests that the presence of ileal pouch PGM is associated with postoperative complications and favors a diagnosis of CD over UC with chronic pouchitis.

Early versus late adhesiolysis for adhesive-related intestinal obstruction: a nationwide analysis of inpatient outcomes

BACKGROUND

Classical teaching advocates watchful waiting for 2 days before operating on adhesive-related intestinal obstructions (AIOs). Our aim was to compare the clinical and cost outcomes of early versus late adhesiolysis for AIOs.

DESIGN

Patients undergoing adhesiolysis for AIOs from the 2007 Nationwide Inpatient Sample were stratified to early (≤2 days from admission) vs. late (>2 days) adhesiolysis. The primary outcome was in-hospital mortality and secondary outcomes were post-operative complications (POCs), post-operative length of stay (PLOS), and in-hospital cost.

RESULTS

From 5,443 patients who underwent adhesiolysis for AIOs, 53 and 47 % underwent early and late adhesiolysis, respectively. Late adhesiolysis patients were older (65.0 vs. 60.1 years) and more co-morbid compared to the early group (p < 0.05). After adjustment with propensity score methods, late adhesiolysis patients had no difference in mortality (odds ratio [OR] 0.95, 95%-confidence intervals [CI] 0.67-1.36, p = 0.79) or POCs (OR 1.01, 95%CI 0.89-1.14, p = 0.91) compared to the early group, but had 9.8 % increased PLOS and 41.9 % increased in-hospital cost (p < 0.001).

CONCLUSIONS

The 2-day limit of watchful waiting is not associated with increased mortality or POCs for those patients undergoing adhesiolysis for an AIO. Late adhesiolysis, however, was associated with significantly increased PLOS and in-hospital cost compared to early adhesiolysis.

ASCA IgG and CBir antibodies are associated with the development of Crohn's disease and fistulae following ileal pouch-anal anastomosis

BACKGROUND

For ulcerative colitis (UC) patients undergoing ileal pouch-anal anastomosis (IPAA), postoperative complications include chronic pouchitis and development of Crohn's disease (CD) of the pouch.

AIMS

The aim of this study was to determine if serologic markers obtained postoperatively are associated with the development of complications in UC patients after IPAA.

METHODS

A retrospective chart review was conducted of UC patients with IPAA were tested for expression of serologic markers. Complications abstracted from medical records included postoperative fistula, CD of the pouch, chronic pouchitis, and diversion or excision of the pouch.

RESULTS

142 patients were enrolled, 44 of whom developed complications. Positive serologic profiles for ASCA IgG and anti-CBir1 markers were found to be associated with the development of any complication, (P = 0.017 and P = 0.002, respectively). A positive anti-CBir1 test was also found to be associated with CD of the pouch and/or fistula formation (P < 0.001). Similarly, both ASCA IgG and anti-CBir1 titers were significantly associated with postoperative IPAA complications (P = 0.034 and P = 0.001, respectively), and anti-CBir1 titers were associated with CD of the pouch and/or fistula formation (P < 0.001). Complications developed after a median follow-up of 216 months (range 1-264).

CONCLUSIONS

ASCA IgG and anti-CBir1 markers were associated with the development of complications after IPAA, specifically fistulae and/or CD of the pouch. The ability to identify patients at high risk for adverse outcomes may allow for early aggressive therapy, which may decrease the rate of pouch failure. A prospective study of patients with preoperative serology is ongoing.

LITAF mediation of increased TNF-α secretion from inflamed colonic lamina propria macrophages

Dysregulation of TNF-α in lamina propria macrophages (LPM) is a feature of inflammatory bowel diseases (IBD). LPS-Induced-TNF-Alpha-Factor (LITAF) is a transcription factor that mediates TNF-α expression. To determine whether LITAF participates in the mediation of TNF-α expression in acutely inflamed colonic tissues, we first established the TNBS-induced colonic inflammation model in C57BL/6 mice. LPM were harvested from non-inflamed and inflamed colonic tissue and inflammatory parameters TNF-α and LITAF mRNA and protein levels were measured ex-vivo. LPM from TNBS-treated mice secreted significantly more TNF-α at basal state and in response to LPS than LPM from untreated mice (p<0.05). LITAF mRNA and protein levels were elevated in LPM from TNBS compared with untreated animals and LPS further increased LITAF protein levels in LPM from inflamed tissue (P<0.05). To further confirm the role of LITAF in acutely inflamed colonic tissues, TNBS-induced colonic inflammation was produced in LITAF macrophage specific knockout mice (LITAF mac -/- mice) and compared to wild type (WT) C57BL/6. Twenty four hours following TNBS administration, colonic tissue from LITAF mac -/- mice had less MPO activity and reduced colonic TNF-α mRNA then WT C57BL/6 mice (p<0.05). LPM harvested from LITAF mac -/- secreted significantly less TNF-α in response to LPS than wild type (WT) C57BL/6 (p<0.05). This study provides evidence that LITAF contributes to the regulation of TNF-α in LPM harvested following acute inflammation or LPS treatment paving the way for future work focusing on LITAF inhibitors in the treatment of TNF-α-mediated inflammatory conditions.

Comparative NMR analysis of an 80-residue G protein-coupled receptor fragment in two membrane mimetic environments

Fragments of integral membrane proteins have been used to study the physical chemical properties of regions of transporters and receptors. Ste2p(G31-T110) is an 80-residue polypeptide which contains a portion of the N-terminal domain, transmembrane domain 1 (TM1), intracellular loop 1, TM2 and part of extracellular loop 1 of the α-factor receptor (Ste2p) from Saccharomyces cerevisiae. The structure of this peptide was previously determined to form a helical hairpin in lyso-palmitoylphosphatidyl-glycerol micelles (LPPG) [1]. Herein, we perform a systematic comparison of the structure of this protein fragment in micelles and trifluoroethanol (TFE):water in order to understand whether spectra recorded in organic:aqueous medium can facilitate the structure determination in a micellar environment. Using uniformly labeled peptide and peptide selectively protonated on Ile, Val and Leu methyl groups in a perdeuterated background and a broad set of 3D NMR experiments we assigned 89% of the observable atoms. NOEs and chemical shift analysis were used to define the helical regions of the fragment. Together with constraints from paramagnetic spin labeling, NOEs were used to calculate a transiently folded helical hairpin structure for this peptide in TFE:water. Correlation of chemical shifts was insufficient to transfer assignments from TFE:water to LPPG spectra in the absence of further information.

Preoperative infliximab is not associated with an increased risk of short-term postoperative complications after restorative proctocolectomy and ileal pouch-anal anastomosis

INTRODUCTION

Considerable controversy exists over whether the preoperative use of infliximab (IFX) for refractory ulcerative colitis (UC) increases the risk for surgical complications after restorative proctocolectomy and ileal pouch-anal anastomosis (IPAA). The aim of this study was to assess the association between preoperative IFX use and short-term surgical complications in a single-surgeon cohort at a tertiary care academic center.

METHODS

UC patients who underwent IPAA from September 2005 through May 2009 were retrospectively identified. Twenty-nine patients treated with IFX within 12 weeks of surgery and 52 non-IFX control subjects were identified. Short-term postoperative outcomes were compared between groups occurring within 30 days of loop ileostomy closure.

RESULTS

Patients were similar with respect to demographics, co-morbidities, rate of emergency surgery, hand-sewn anastomosis, and preoperative use of cyclosporine, azathioprine, and high-dose steroids. IFX patients were more likely to have received a laparoscopic hand-assisted IPAA, low-, medium-, and any-dose steroids, 6-mercaptopurine (6-MP), methotrexate, and to have failed medical therapy. There was no short-term mortality. Overall postoperative and infectious complications were similar between IFX and non-IFX groups. Multivariate regression models revealed no independent predictors for postoperative complications when including IFX [odds ratio (OR) 0.78, p = 0.67], laparoscopic hand-assisted IPAA, 6-MP, methotrexate, steroids, failure of medical therapy, and body mass index.

CONCLUSIONS

Preoperative IFX use was not associated with an increased risk of short-term postoperative complications after IPAA.

Open adhesiolysis is more effective in reducing adhesion reformation than laparoscopic adhesiolysis in an experimental model

BACKGROUND

This study compared adhesion reformation after open and laparoscopic adhesiolysis in a rat model.

METHODS

Adhesions were induced by surgically creating ischaemic buttons on the peritoneal side wall. After 7 days the animals underwent laparoscopy with carbon dioxide insufflation or laparotomy to score and lyse adhesions. Peritoneal tissue and fluid were collected after 24 h in a subset of animals, and adhesion reformation was scored 7 days after lysis in the remainder. Tissue plasminogen activator (tPA), plasminogen activator inhibitor (PAI) 1, transforming growth factor (TGF) beta1 and tumour necrosis factor (TNF) alpha mRNA, and total fibrinolytic activity were assessed. The abdomen of non-operated animals was insufflated for 7, 15 or 30 min with carbon dioxide, after which tPA and PAI-1 mRNA and total fibrinolytic activity were measured.

RESULTS

Animals that underwent open adhesiolysis had 60 per cent fewer reformed adhesions than the laparoscopic adhesiolysis group (P < 0.001). There were no differences in tPA activity or tPA, PAI-1 and TNF-alpha mRNA between groups, but TGF-beta1 mRNA levels were significantly increased in the open group. Carbon dioxide insufflation did not affect peritoneal tPA activity.

CONCLUSION

Open adhesiolysis may be more beneficial in minimizing adhesion reformation in the management of adhesion-related complications.

Practical limitations of bioresorbable membranes in the prevention of intra-abdominal adhesions

INTRODUCTION

Intra-abdominal adhesions are a significant source of postoperative morbidity. Bioresorbable barriers composed of hyaluronic acid and carboxymethylcellulose (HA/CMC) reduce adhesion formation by physically separating injured or healing peritoneal surfaces. To assess whether the efficacy of a physical barrier can extend beyond the site of application, we evaluated the effectiveness of an HA/CMC barrier in preventing adhesions distal to the site of placement.

METHODS

Adhesions were induced in rats by creating peritoneal ischemic buttons on either side of a midline incision. An HA/CMC barrier (Seprafilm Genzyme) was intraoperatively placed either under the midline incision, unilaterally over half the ischemic buttons, or bilaterally over all ischemic buttons. Control buttons received no HA/CMC. On day 7 adhesions were scored. In similar experiments, peritoneal fluid was collected at 24 h to assess the effects of HA/CMC on tissue plasminogen activator activity.

RESULTS

Placement of HA/CMC under the midline incision did not reduce adhesion formation to distal ischemic buttons (72 +/- 7%) compared to controls (80 +/- 8%). Unilateral placement of HA/CMC significantly (p < 0.05) reduced adhesion formation to those ischemic buttons over which the barrier was applied (35 +/- 7%) compared to both contralateral (83 +/- 9%) and control (80 +/- 8%) ischemic buttons. The bilateral application of HA/CMC also significantly (p < 0.05) reduced adhesion formation to all ischemic buttons compared to controls (22 +/- 7% vs. 66 +/- 7%, respectively). HA/CMC did not affect peritoneal tPA activity.

CONCLUSIONS

Effective adhesion reduction by the physical barrier HA/CMC appears to be limited to the site of application in this rat model. Despite the presence of a bioresorbable membrane at predicted sites of adhesion formation in the peritoneal cavity, adhesions readily form to distal unprotected sites.

An FDA approved neurokinin-1 receptor antagonist is effective in reducing intraabdominal adhesions when administered intraperitoneally, but not orally

INTRODUCTION

Postoperative adhesions pose a continued healthcare problem. We previously demonstrated that intraperitoneal (i.p.) administration of a neurokinin-1 receptor antagonist (NK-1RA) at surgery reduces intraabdominal adhesions in rats. The NK-1RA aprepitant (Emend, Merck) is clinically approved for preventing postoperative nausea and vomiting; however, its effects on adhesion formation are unknown. Thus, we determined the effects of i.p. and oral administration of aprepitant on adhesion formation in a rat model.

METHODS

Adhesions were surgically induced in rats that were randomized to receive either one or five oral preoperative doses or a single intraoperative i.p. dose of aprepitant (50 mg/kg). Adhesions were scored at 7 days. In similar experiments using i.p. dosing, animals were sacrificed at 24 h and peritoneal fluid, and tissue were collected to assess fibrinolytic activity and tissue plasminogen activator (tPA) and plasminogen activator inhibitor-1 (PAI-1) mRNA levels, respectively.

RESULTS

I.p. aprepitant reduced adhesion formation by 33% (p < 0.05) compared with controls while oral aprepitant had no effect. Compared to controls i.p. aprepitant reduced tPA activity by 55% (p < 0.05), increased PAI-1 mRNA levels by 140% (p < 0.05), and had no affect on tPA mRNA levels.

CONCLUSION

These data suggest that aprepitant maybe a useful pharmacologic agent for reducing adhesion formation clinically.

Intraperitoneal Administration of Methylene Blue Attenuates Oxidative Stress, Increases Peritoneal Fibrinolysis, and Inhibits Intraabdominal Adhesion Formation

BACKGROUND

Mounting evidence indicates that postoperative oxidative stress may be linked to decreased fibrinolytic activity and, subsequently, the development of intraabdominal adhesions. The goal of this study was to determine if methylene blue, a highly redox active dye that has been shown to inhibit adhesion formation (1) acts as an antioxidant in the postoperative peritoneum, and (2) subsequently affects fibrinolytic activity.

MATERIALS AND METHODS

Intraabdominal adhesions were surgically induced in rats receiving methylene blue (30 mg/kg) or vehicle (sterile water) intraperitoneally at surgery. At 24 h and 7 d following surgery, adhesion formation, oxidative stress, and peritoneal fibrinolytic activity were assessed.

RESULTS

Methylene blue did not affect adhesion formation at 24 h, but did induce a >50% regression in adhesions after 7 d (P < 0.05). Nicotinamide adenine dinucleotide phosphate (NADPH) oxidase and myeloperoxidase (MPO) activities, and 8-isoprostane and thiobarbituric acid-reactive substances were all significantly increased in peritoneal tissue samples (P < 0.05) by 24 h following surgery. Methylene blue inhibited NADPH oxidase by 98% and MPO activity by 78% in the 24 h tissue samples, and blunted the corresponding surgery-induced increases in tissue lipid and protein oxidation. Furthermore, methylene blue significantly increased (P < 0.05) fibrinolytic activity in peritoneal fluid at 24 h.

CONCLUSIONS

Methylene blue acts as an antioxidant in this experimental system and may reduce intraabdominal adhesion formation by enhancing peritoneal fibrinolytic activity following surgery.

A neurokinin-1 receptor antagonist that reduces intra-abdominal adhesion formation decreases oxidative stress in the peritoneum

Oxidative stress has been implicated in intra-abdominal adhesion formation. Substance P, a neurokinin-1 receptor (NK-1R) ligand, facilitates leukocyte recruitment and reactive oxygen species (ROS) generation. We have shown in a rat model of adhesion formation that intraperitoneal administration of a NK-1R antagonist at the time of abdominal operation reduces postoperative adhesion formation. Thus we determined the effects of NK-1R antagonist administration on peritoneal leukocyte recruitment and oxidative stress within 24 h of surgery. Adhesions were induced in Wistar rats randomly assigned to receive the antagonist or vehicle intraperitoneally. Peritoneal tissue was isolated at 2, 4, 6, and 24 h after surgery for analysis of the oxidative stress biomarkers 8-isoprostane (8-IP), protein carbonyl, NADPH oxidase, myeloperoxidase (MPO), and ICAM-1 and VCAM-1 mRNAs. Total antioxidant capacity of peritoneal fluid was also determined. MPO, NADPH oxidase, 8-IP, and protein carbonyl were elevated (P < 0.05) by 6 h. ICAM-1 mRNA was elevated (P < 0.05) by 2 h, whereas VCAM-1 levels decreased (P < 0.05) at 24 h. The NK-1R antagonist delayed the MPO rise and reduced (P < 0.05) 8-IP levels by 6 h and ICAM-1 mRNA, VCAM-1 mRNA, and protein carbonyl at 2 h. The antagonist also increased (P < 0.05) the antioxidant capacity of peritoneal fluid at all time points. These data further support a role for oxidative stress in adhesion formation and suggest that the NK-1R antagonist may limit adhesions, in part, by reducing postoperative oxidative stress through an inhibition of neutrophil recruitment and an increase in peritoneal fluid antioxidant capacity.

Carcinoembryonic antigen-stimulated THP-1 macrophages activate endothelial cells and increase cell–cell adhesion of colorectal cancer cells

The liver is the most common site for metastasis by colorectal cancer, and numerous studies have shown a relationship between serum carcinoembryonic antigen (CEA) levels and metastasis to this site. CEA activates hepatic macrophages or Kupffer cells via binding to the CEA receptor (CEA-R), which results in the production of cytokines and the up-regulation of endothelial adhesion molecules, both of which are implicated in hepatic metastasis. Since tissue macrophages implicated in the metastatic process can often be difficult to isolate, the aim of this study was to develop an in vitro model system to study the complex mechanisms of CEA-induced macrophage activation and metastasis. Undifferentiated, human monocytic THP-1 (U-THP) cells were differentiated (D-THP) to macrophages by exposure to 200 ng/ml phorbol myristate acetate (PMA) for 18 h. Immunohistochemistry showed two CEA-R isoforms present in both U- and D-THP cells. The receptors were localized primarily to the nucleus in U-THP cells, while a significant cell-surface presence was observed following PMA-differentiation. Incubation of D-THP-1 cells with CEA resulted in a significant increase in tumor necrosis factor-alpha (TNF-alpha) release over 24 h compared to untreated D-THP-1 or U-THP controls confirming the functionality of these cell surface receptors. U-THP cells were unresponsive to CEA. Attachment of HT-29 cells to human umbilical vein endothelial cells significantly increased at 1 h after incubation with both recombinant TNF-alpha and conditioned media from CEA stimulated D-THP cells by six and eightfold, respectively. This study establishes an in vitro system utilizing a human macrophage cell line expressing functional CEA-Rs to study activation and signaling mechanisms of CEA that facilitate tumor cell attachment to activated endothelial cells. Utilization of this in vitro system may lead to a more complete understanding of the expression and function of CEA-R and facilitate the design of anti-CEA-R therapeutic modalities that may significantly diminish the metastatic potential of CEA overexpressing colorectal tumors.

A neurokinin 1 receptor antagonist decreases adhesion reformation after laparoscopic lysis of adhesions in a rat model of adhesion formation

BACKGROUND

Up to 94% of patients experience fibrous adhesions after abdominal surgery, and a significant number of these patients require a second operation for open or laparoscopic lysis of adhesions (LOA). The authors have previously shown that inhibition of the binding of tachykinin ligands to the neurokinin 1 receptor (NK-1R) using the neurokinin 1 receptor antagonist (NK-1RA) CJ-12,255 decreases primary adhesion formation and upregulates the peritoneal fibrinolytic system in a rat model. Whereas most studies have focused on the prevention of primary adhesions, few have addressed adhesion reformation after LOA. This study aimed to determine the effects of NK-1RA administration on adhesion reformation and peritoneal fibrinolytic activity after laparoscopic LOA.

METHODS

Adhesions were induced in 31 rats using our previously described ischemic button model. The rats underwent laparoscopy 7 days later, during which adhesions were scored and lysed followed by administration of the NK-1RA or saline. Then 7 days after LOA, 23 rats were killed and adhesions were scored. Eight rats also were killed 24 h after the LOA to obtain peritoneal tissue and fluid, which were analyzed for tissue plasminogen activator (tPA) mRNA expression and peritoneal fibrinolytic activity by reverse transcriptase-polymerase chain reaction (RT-PCR) and bioassay, respectively.

RESULTS

At laparoscopy, 79% +/- 3% of the buttons formed adhesions. In the saline-administered control animals, 42% +/- 3.2% of the buttons reformed adhesions after LOA (p < 0.05), whereas in the animals that received the NK-1RA, 18.2% +/- 3.5% of the buttons reformed adhesions (p < 0.05). As compared with control animals, NK-1RA administration increased tPA mRNA levels by 38% and fibrinolytic activity sixfold (p < 0.05; 7.0 +/- 2.1 U/ml vs 1.2 +/- 0.54 U/ml).

CONCLUSIONS

When administered during laparoscopic LOA, an NK-1RA significantly upregulates peritoneal fibrinolytic activity and decreases adhesion reformation.

The effectiveness of a single intraperitoneal infusion of a neurokinin-1 receptor antagonist in reducing postoperative adhesion formation is time dependent

BACKGROUND

Current methods to prevent intraabdominal adhesions are not uniformly effective. We recently showed in rats that a neurokinin-1 receptor (NK-1R) antagonist is capable of reducing adhesion formation. To determine the clinical feasibility of using an NK-1R antagonist to reduce adhesions, this study examined the time dependence for the effectiveness of NK-1R antagonist administration and its effects on wound healing.

METHODS

Adhesions were surgically induced in rats receiving a single intraperitoneal infusion of the NK-1R antagonist, CJ-12,255, during or 1, 5, 12, or 24 hours after surgery. Adhesion formation was assessed 7 days later. In a subset of animals, tissue plasminogen activator (tPA) activity, which is a measure of peritoneal fibrinolytic activity, was determined in peritoneal fluid 24 hours after surgery (48 hours for animals infused at 24 hours). The tPA activity was also determined in nonoperated animals 24 hours after peritoneal injection of the NK-1R antagonist. Colonic burst pressures were measured 7 days after creation of anastomoses in rats that were administered the antagonist at surgery.

RESULTS

The NK-1R antagonist significantly reduced (P=.003) intraabdominal adhesions when administered during or 1 hour after surgery, only moderately reduced (P=.08) adhesions when administered at 5 hours, and had no effect at 12 or 24 hours. Peritoneal tPA activity was significantly increased (P<.05) in peritoneal fluid 24 hours after administration of the NK-1R antagonist regardless of the surgical procedure. The NK-1R antagonist did not alter colonic anastomotic healing.

CONCLUSIONS

These data show that some of the events critical to adhesion formation occur within the first 5 hours following an abdominal operation in this model. The fact that the NK-1R antagonist does not impair colonic anastomotic healing enhances its usefulness as a therapeutic agent to inhibit adhesion formation.

Statins (HMG-CoA reductase inhibitors) decrease postoperative adhesions by increasing peritoneal fibrinolytic activity

OBJECTIVES

The aims of this study were to determine if statins reduce adhesion formation in vivo and to identify the mechanism of action in vitro.

BACKGROUND

: Intraperitoneal adhesions develop in up to 95% of patients following laparotomy. Adhesions are reduced by mechanisms that up-regulate fibrinolysis within the peritoneum. Statins promote fibrinolysis in the cardiovascular system and may play a role in the prevention of adhesions.

METHODS

Adhesions were induced in rats (n = 102) using our previously described ischemic button model. Rats received vehicle (controls), lovastatin (30 mg/kg), or atorvastatin (30 mg/kg) as a single intraperitoneal dose at the time of laparotomy. Animals were killed and adhesions were quantified at day 7. Peritoneal fluid and tissue were collected at day 1 to measure tissue plasminogen activator (tPA) and plasminogen activator inhibitor-1 (PAI-1) by real-time PCR and ELISA. To assess the effects of statins on wound healing, burst pressures were measured in anastomoses of the colon. The effects of lovastatin on tPA and PAI-1 production were measured in vitro in human mesothelial cells (HMC) in the presence or absence of mevalonate (MVA), geranylgeranyl-pyrophosphate (GGPP) and farnesyl-pyrophosphate (FPP), all intermediates in the cholesterol pathway downstream of HMG-CoA. The effect of a Rho protein inhibitor, exoenzyme C3 transferase, on tPA production was also determined.

RESULTS

Lovastatin and atorvastatin reduced adhesion formation by 26% and 58%, respectively (P < 0.05), without affecting anastomotic burst pressure. At 24 hours, tPA mRNA levels in peritoneal tissue and tPA activity in peritoneal fluid from lovastatin-treated animals were increased by 57% and 379%, respectively (P < 0.05), while PAI-1 levels were unchanged. HMC incubated with either lovastatin or atorvastatin showed concentration-dependent increases in tPA production and decreases in PAI-1 production (P < 0.05). These lovastatin-induced changes in tPA and PAI-1 production were significantly reversed by the addition of MVA, GGPP, and FPP. The Rho protein inhibitor increased tPA production and rescued tPA production from the inhibitory effect of GGPP.

CONCLUSION

These data suggest that statins administered within the peritoneum can up-regulate local fibrinolysis, while the in vitro studies show that this effect may be mediated, in part, by intermediates of the cholesterol biosynthetic pathway that regulate Rho protein signaling.

Time series analysis of variables associated with daily mean emergency department length of stay

STUDY OBJECTIVE

We measure the effect of various input, throughput, and output factors on daily emergency department (ED) mean length of stay per patient (daily mean length of stay).

METHODS

The study was a retrospective review of 93,274 ED visits between April 15, 2002, and December 31, 2003. The association between the daily mean length of stay and the independent variables was assessed with autoregressive moving average time series analysis (ARIMA). The following independent variables were measured per 24-hour period: number of elective surgical admissions, ED volume, number of ED admissions, number of ED ICU admissions, number of ED clinical attending hours, hospital medical-surgical occupancy (hospital occupancy), and day of the week.

RESULTS

Three factors were independently associated with daily mean length of stay in time series analysis: number of elective surgical admissions, number of ED admissions, and hospital occupancy. The daily mean length of stay increased by 0.21 minutes for every additional elective surgical admission, 2.2 minutes for every additional admission, and 4.1 minutes for every 5% increase in hospital occupancy. Elective surgical admissions were associated with a maximum of 35 hours of additional ED dwell time. The model accounted for 31.5% of the variability in daily mean length of stay. The final model parameters for the ARIMA analysis were autoregressive term (1) moving average (1).

CONCLUSION

Hospital occupancy and the number of ED admissions are associated with daily mean length of stay. Every additional elective surgical admission prolonged the daily mean length of stay by 0.21 minutes per ED patient. Autocorrelation exists between the daily mean length of stay of the current day and the previous day.

MRI of complicated pouchitis

OBJECTIVE

The purpose of this study is to assess the ability of MRI to identify the presence of inflammation related to the pouch reservoir in symptomatic patients with an ileal pouch-anal anastomosis who present with clinically suspected complicated pouchitis.

CONCLUSION

Initial results suggest that MRI should be considered in patients who have undergone ileal pouch-anal anastomosis and present a clinical impression of complicated pouchitis. MRI showed abnormalities consistent with complicated pouchitis in seven of nine examinations, with findings including pouch wall thickening, abnormal wall enhancement, peripouch fluid collection, sinus and fistula tract formation, lymphadenopathy, and peripouch stranding and fatty proliferation. MRI findings of complicated pouchitis should raise the suspicion of Crohn's disease and should prompt further investigation.

Surgical approaches to cancer in patients who have inflammatory bowel disease

IBD clearly increases the risk for GI malignancies, especially CRC. The absolute number of patients that develops such malignancies is low compared with the overall cancer rate; however, younger age of onset, higher relative risk, unique clinical presentations, and problems with early diagnosis make this a serious complication of IBD. With the exception of patients with comorbid complications, such as primary sclerosing cholangitis, the prognosis is no worse for CRCs that arise as the result of IBD compared with those that arise sporadically. The prognosis remains poor for small bowel adenocarcinomas in patients who have CD, primarily because of their advanced stage at detection. Diligent surveillance is essential for early detection and treatment of IBD-related CRCs in patients with unresected colons, long-standing or extensive disease, and in those who have early-onset CD, although pundits still question whether it significantly affects prognosis and survival. Better surveillance techniques for small bowel dysplasia or malignancy in patients who have CD is needed, especially given the poor prognosis of these patients when advanced cancers are detected. Depending on the presentation and disease diagnosis, patients have several surgical treatment options and can expect good outcomes for all. When the appropriate surgical technique is used in patients who have colon or rectal cancer, along with adjuvant chemotherapy when appropriate, prognosis and function is good; however, the experience of the surgeon can affect the prognosis for IBD-related GI cancers. Surgical therapy is based not only on general oncologic principles, but also on the surgery that is appropriate for the IBD diagnosis. Resection of the mesentery and lymphadenectomy should be performed according to oncologic principles. Postoperative survival for IBD-related CRC is good, and diligent surveillance and follow-up are critical to the patient's overall prognosis.

Anti-Saccharomyces cerevisiae antibodies are associated with the development of postoperative fistulas following ileal pouch-anal anastomosis

Although serologic testing for perinuclear antineutrophil cytoplasmic antibodies (pANCA) and anti-Saccharomyces cerevisiae antibodies (ASCA) is reportedly useful in distinguishing ulcerative colitis (UC) from Crohn's disease (CD), there are few and conflicting reports assessing their utility in predicting postoperative complications after ileal pouch-anal anastomosis (IPAA). We examined the associations between postoperative complications such as pouchitis or fistulas and pANCA and ASCA antibodies in a group of patients who underwent IPAA for UC. We conducted a retrospective chart review of 34 patients initially diagnosed with UC (four of these patients had a diagnosis of indeterminate colitis) who underwent IPAA by a single surgeon, and who had pANCA and ASCA antibody levels measured during their clinical course. Study patients were assigned to four groups based on the pattern of antibody reactivity: pANCA+/ASCA- (16 patients), pANCA-/ASCA+ (nine patients), pANCA+/ASCA+ (five patients), and pANCA-/ASCA- (four patients). The median length of follow-up was 16 months (3-144 months). None of the patients (0 of 16) who were pANCA+/ASCA- had their preoperative diagnosis of UC changed after a median follow-up of 14 months (3-118 months). Of the nine patients with a preoperative diagnosis of UC who were pANCA-/ASCA+, four patients (44%) had their diagnosis changed postoperatively to CD based on clinical findings, with a median follow-up: 15 months (5-98 months). Of 16 patients who underwent IPAA and who were pANCA+/ASCA-, 15 of 16 (93.75%), were free of fistulas postoperatively, with a median follow-up of 14 months (3-118 months). Of nine patients with a preoperative diagnosis of UC who underwent IPAA and who were pANCA-/ASCA+, four of nine (44%; p = 0.04) developed fistulas postoperatively, with a median length of follow-up of 55 months (15-67 months). No relationship between serologic profiles or antibody titer levels and the development of pouchitis was identified. In a cohort of patients undergoing IPAA for UC, serologic profiles may be useful in identifying patients at risk of postoperative fistula formation. Patients who were pANCA-/ASCA+ were at increased risk for the development of fistulas postoperatively compared to patients who were pANCA+/ASCA-, and were also more likely to have their diagnosis changed postoperatively to CD. A larger study is needed to validate these observations.

ThPTR2, a di/tri-peptide transporter gene from Trichoderma harzianum

The generation of a wide ESTs library and database from Trichoderma harzianum CECT 2413 was the base for identifying the gene ThPTR2, coding for a PTR family di/tri-peptide transporter. The deduced protein sequence of the ThPTR2 gene showed the conserved motifs and also the 12 transmembrane domains typical of the PTR transporters. The highest level of ThPTR2 expression was found when the fungus was grown in chitin as sole carbon source. We also found that ThPTR2 expression was increased when Trichoderma interacted directly in solid medium with the plant-pathogenic fungus Botrytis cinerea, showing that ThPTR2 is involved in the mycoparasitic process. Additionally, its expression was triggered by nitrogen starvation and a higher level of expression was also found when Trichoderma was grown in secondary nitrogen sources like allantoin, yeast extract, and urea. However, no difference was found when Trichoderma was grown in presence or absence of glucose as carbon source. Strain T34-15, a transformant that overexpressed the ThPTR2 gene, showed about a 2-fold increase in the uptake of the dipeptide Leu-Leu. Additionally, two transformants from the strain Trichoderma longibrachiatum T52 that overexpressed ThPTR2 were also studied, confirming the role of this gene in peptide transport. Other homologous genes to ThPTR2 were identified in other Trichoderma strains. ThPTR2 is the first experimentally confirmed PTR family transporter gene from filamentous fungi.

Prognostic Significance of Superficial Fissuring Ulceration in Patients With Severe “Indeterminate” Colitis

Some colectomy specimens from patients with severe colitis contain superficial fissuring-type ulcers but do not have any other features of Crohn's disease (CD). This finding may cause difficulty with regard to distinguishing ulcerative colitis (UC) from CD and, thus, lead to a diagnosis of "indeterminate" colitis. The aim of this study was to evaluate the clinical and pathologic features, and outcome, of a cohort of patients with colitis and superficial fissuring ulcers, but without any other features that may suggest a diagnosis of CD. We retrospectively identified 21 patients (male-to-female ratio, 10/11; mean age, 38 years) with severe chronic active colitis, all of whom had at least one (range, 1-3) superficial fissuring ulcer in their colectomy specimens (but without any other features of CD), as well as a control group of 18 patients (male-to-female ratio, 10/8; mean age, 41 years) with equally severe disease, but without fissuring ulcers. Both groups were evaluated for a variety of clinical and pathologic features, such as clinical presentation, degree, extent, and duration of colitis, and follow-up information, such as the development of pouchitis, pouch fistulae, and any other features of CD. Overall, 81% of the study patients presented clinically with fulminant colitis and underwent an emergent or urgent colectomy, compared with only 41% of the control patients (P = 0.02). Nine (43%) study patients had active serositis in their colectomy specimens, whereas only 1 (6%) control patient had this finding (P = 0.002). However, no significant differences were noted in either the extent or severity of disease or the presence of active ("backwash") ileitis, between the study and control groups. Upon follow-up (mean, 42 months; range, 4-121 months), the study patients with superficial fissuring ulcers developed pouchitis significantly more often (68% vs. 20%, P = 0.007) than the control group following an ileal pouch-anal anastomosis (IPAA) procedure. One patient from each group developed an anal fissure and another from each group developed an anastomotic stricture. In addition, 1 study patient developed a pouch-cutaneous fistula, and 1 control patient developed an enterocutaneous fistula to a loop ileostomy. Finally, 1 control patient ultimately had her pouch excised because of recurrent intractable pouchitis. However, none of the other study or control patients developed any clinical or pathologic manifestations of CD. We conclude that superficial fissuring ulcers may occur in patients with severe chronic active UC, particularly those who present with fulminant disease. Affected individuals should not be considered to have CD or "indeterminate" colitis and should not be denied an IPAA procedure. Nevertheless, the presence of superficial fissuring-type ulcers in patients with severe chronic active UC denotes a subgroup with a higher risk of pouchitis following surgical resection.

Pathologic features and clinical significance of "backwash" ileitis in ulcerative colitis

Patients with ulcerative colitis (UC) may develop inflammation in the distal ileum thought to be due to "backwash" of cecal contents ("backwash ileitis"). However, a systematic analysis of ileal changes in UC has never been performed, and the prevalence and criteria for "backwash" ileitis have not been defined. The aim of this study was to evaluate the prevalence and spectrum of inflammatory changes in the ileum in patients with UC and to correlate ileal changes with outcome after total proctocolectomy and ileal pouch-anal anastomosis. Routinely processed ileocolonic resection specimens from 200 consecutive patients with clinically and pathologically confirmed UC were evaluated for a wide variety of pathologic features in the ileum and colon. The ileal data were correlated with both the clinical features and the pathologic findings in the colon. Follow-up data were obtained to confirm absence of Crohn's disease and to evaluate outcome of ileo-anal pouches. Overall, 34 of 200 (17%) UC patients had inflammatory changes in the ileum (male/female ratio, 16/18; mean age, 42 years); 32 of 34 (94%) had pancolitis, which was significantly higher than the rate of pancolitis (39%) in patients without ileal disease (N = 166) (P < 0.001), but there were no other differences between patients with or without ileal pathology. In the colon, 22 of 34 (65%) patients had severe activity. Ileal changes included villous atrophy and crypt regeneration without increased inflammation (N = 3), increased neutrophilic and mononuclear inflammation in the lamina propria (N = 6), patchy cryptitis and crypt abscesses (N = 21) and focal superficial surface erosions (N = 4), some with pyloric metaplasia (N = 2 of 4). In general, the severity of ileal changes paralleled the severity of colonic activity. However, 2 of 4 (50%) patients with superficial erosions in the ileum had subtotal or left-sided colitis only, and had only mild colonic activity. Other cases showed only mild to moderate colonic activity and patchy or discontinuous involvement of the distal ileum. Upon follow-up of patients with erosions (mean, 48.5 months; range, 26-102 months), none developed manifestations of Crohn's disease anywhere in the gastrointestinal tract. The presence of inflammatory changes in the ileum had no effect on the prevalence of pouch complications or on the occurrence of dysplasia or cancer. Ileal changes in UC are not uncommon (prevalence, 17%), are generally mild in nature (villous atrophy, increased inflammation, scattered crypt abscesses), and are not associated with an increased rate of ileo-anal pouch complications, dysplasia, or carcinoma. In some cases, our findings are consistent with a backwash etiology. However, rarely, ileal erosions may occur in patients without cecal involvement, which may indicate that other pathogenetic mechanisms should be considered in the etiology of ileitis in UC patients.

Reduction in adhesive small-bowel obstruction by Seprafilm adhesion barrier after intestinal resection

INTRODUCTION

Although Seprafilm has been demonstrated to reduce adhesion formation, it is not known whether its usage would translate into a reduction in adhesive small-bowel obstruction.

METHODS

This was a prospective, randomized, multicenter, multinational, single-blind, controlled study. This report focuses on those patients who underwent intestinal resection (n = 1,701). Before closure of the abdomen, patients were randomized to receive Seprafilm or no treatment. Seprafilm was applied to adhesiogenic tissues throughout the abdomen. The incidence and type of bowel obstruction was compared between the two groups. Time to first adhesive small-bowel obstruction was compared during the course of the study by using survival analysis methods. The mean follow-up time for the occurrence of adhesive small-bowel obstruction was 3.5 years.

RESULTS

There was no difference between the treatment and control group in overall rate of bowel obstruction. The incidence of adhesive small-bowel obstruction requiring reoperation was significantly lower for Seprafilm patients compared with no-treatment patients: 1.8 vs. 3.4 percent (P < 0.05). This finding represents an absolute reduction in adhesive small-bowel obstruction requiring reoperation of 1.6 percent and a relative reduction of 47 percent. In addition, a stepwise multivariate analysis indicated that the use of Seprafilm was the only predictive factor for reducing adhesive small-bowel obstruction requiring reoperation. In both groups, 50 percent of first adhesive small-bowel obstruction episodes occurred within 6 months after the initial surgery with nearly 30 percent occurring within the first 30 days. Additionally no first adhesive small-bowel obstruction events were reported in Years 4 and 5 of follow-up.

CONCLUSIONS

The overall bowel obstruction rate was unchanged; however, adhesive small-bowel obstruction requiring reoperation was significantly reduced by the use of Seprafilm, which was the only factor that predicted this outcome.

NF-kappaB activation precedes increases in mRNA encoding neurokinin-1 receptor, proinflammatory cytokines, and adhesion molecules in dextran sulfate sodium-induced colitis in rats

Nuclear factor kappa B (NF-kappa B) plays a key role in initiating inflammation associated with colitis. A systematic study was conducted in the rat DSS colitis model to determine the temporal relationship between NF-kappa B activation and expression of substance P (SP), neurokinin-1 receptor (NK-1R), proinflammatory cytokines, and adhesion molecules. Rats were given 5% DSS in their water and sacrificed daily for 6 days. Colon tissue was collected for assessment of histological changes, NF-kappa B activation, myeloperoxidase (MPO) activity, and expression of NK-1R, SP, TNFalpha, IL-1beta, VCAM-1, ICAM-1, E-selectin, CINC-1, MIP-1alpha, and iNOS. NF-kappa B activation increased, biphasically, on Day 1 and again on Days 4-6. The mRNA levels for ICAM-1, CINC-1, IL-1beta, TNFalpha, VCAM-1, and NK-1R rose significantly (P < 0.05) by 2-4 days. Increased iNOS mRNA levels, MPO activity, and mucosal damage occurred on Day 6. These data demonstrate that NF-kappa B activation substantially precedes the onset of physical disease signs and active inflammation.

Analysis of ligand-receptor cross-linked fragments by mass spectrometry*

G-protein coupled receptors (GPCRs) are a class of integral membrane receptor proteins that are characterized by a signature seven-transmembrane (7-TM) configuration. The alpha-factor receptor (Ste2p) from Saccharomyces cerevisiae is a GPCR that, upon binding of a peptide ligand, transduces a signal to initiate a cascade of events leading to the mating of haploid yeast cells. This study summarizes the application of affinity purification and of matrix-assisted laser-desorption ionization time-of-flight (MALDI-TOF) experiments using biotinylated photoactivatable alpha-factor analogs. Affinity purification and enrichment of biotinylated peptides by monomeric avidin beads resulted in mass spectrometric detection of specific signals corresponding to cross-linked fragments of Ste2p. Data obtained from cyanogen bromide (CNBr) fragments of receptor cross-linked to an alpha-factor analog with the photoaffinity group p-benzoyl-l-phenylalanine on position 1 were in agreement with the previous results reported by our laboratory suggesting the cross-linking between position 1 of alpha-factor and a region of Ste2p covering residues 251-294.