Mary F. Otterson

Chlorhexidine–Alcohol versus Povidone–Iodine for Surgical-Site Antisepsis

BACKGROUND Since the patients skin is a major source of pathogens that cause surgical-site infection, optimization of preoperative skin antisepsis may decrease postoperative infections. We hypothesized that preoperative skin cleansing with chlorhexidine-alcohol is more protective against infection than is povidone-iodine. METHODS We randomly assigned adults undergoing clean-contaminated surgery in six hospitals to preoperative skin preparation with either chlorhexidine-alcohol scrub or povidone-iodine scrub and paint. The primary outcome was any surgical-site infection within 30 days after surgery. Secondary outcomes included individual types of surgical-site infections. RESULTS A total of 849 subjects (409 in the chlorhexidine-alcohol group and 440 in the povidone-iodine group) qualified for the intention-to-treat analysis. The overall rate of surgical-site infection was significantly lower in the chlorhexidine-alcohol group than in the povidone-iodine group (9.5% vs. 16.1%; P=0.004; relative risk, 0.59; 95% confidence interval, 0.41 to 0.85). Chlorhexidine-alcohol was significantly more protective than povidone-iodine against both superficial incisional infections (4.2% vs. 8.6%, P=0.008) and deep incisional infections (1% vs. 3%, P=0.05) but not against organ-space infections (4.4% vs. 4.5%). Similar results were observed in the per-protocol analysis of the 813 patients who remained in the study during the 30-day follow-up period. Adverse events were similar in the two study groups. CONCLUSIONS Preoperative cleansing of the patients skin with chlorhexidine-alcohol is superior to cleansing with povidone-iodine for preventing surgical-site infection after clean-contaminated surgery. (ClinicalTrials.gov number, NCT00290290.)

Animal Models for Medical Countermeasures to Radiation Exposure

Abstract Since September 11, 2001, there has been the recognition of a plausible threat from acts of terrorism, including radiological or nuclear attacks. A network of Centers for Medical Countermeasures against Radiation (CMCRs) has been established across the U.S.; one of the missions of this network is to identify and develop mitigating agents that can be used to treat the civilian population after a radiological event. The development of such agents requires comparison of data from many sources and accumulation of information consistent with the “Animal Rule” from the Food and Drug Administration (FDA). Given the necessity for a consensus on appropriate animal model use across the network to allow for comparative studies to be performed across institutions, and to identify pivotal studies and facilitate FDA approval, in early 2008, investigators from each of the CMCRs organized and met for an Animal Models Workshop. Working groups deliberated and discussed the wide range of animal models available for assessing agent efficacy in a number of relevant tissues and organs, including the immune and hematopoietic systems, gastrointestinal tract, lung, kidney and skin. Discussions covered the most appropriate species and strains available as well as other factors that may affect differential findings between groups and institutions. This report provides the workshop findings.

Acquired microvascular dysfunction in inflammatory bowel disease: loss of nitric oxide-mediated vasodilation

BACKGROUND & AIMS Inflammatory bowel disease (IBD; i.e., Crohns 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. METHODS 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. RESULTS 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% (P < 0.05, 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 (P < 0.01). CONCLUSIONS 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.

Curcumin inhibits VEGF-mediated angiogenesis in human intestinal microvascular endothelial cells through COX-2 and MAPK inhibition

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.

Budesonide induction and maintenance therapy for Crohn's disease during pregnancy

Background: There is no standard approach for the medical management of Crohns 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 Crohns 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.

Permanent Work Disability in Crohn's Disease

OBJECTIVE:Crohns 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 ≤50 (OR 12.44, 95% CI 4.45–34.79), undergoing two or more GI surgeries (OR 7.09, 95% CI 2.63–19.11), and two or more medical hospitalizations (OR 2.76, 95% CI 1.03–7.37) were significantly associated with work disability in CD. Disease location (small bowel vs colon), type (inflammatory, stricturing, or fistulizing), or specific treatment strategies were not associated with work disability in our analysis.CONCLUSION:Permanent work disability administered through social security was encountered in 5.3% of the Crohns patients followed in our cohort. Patients who consistently report low quality of life, or have frequent flares requiring surgical intervention or hospitalization for medical management, may be at risk for CD-related work disability.

Multivariate analysis suggests improved perioperative outcome in Crohn's disease patients receiving immunomodulator therapy after segmental resection and/or strictureplasty.

BACKGROUND Medical management of moderate to severe Crohns 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<.01). IASC were not influenced by steroid use, smoking status, preoperative abscess, or fistula or albumin levels. Immunomodulator use did not affect the length of resection or the rate and number of strictureplasties. CONCLUSION Medical management with immunomodulator therapy is safe and significantly decreases postoperative IASC in CD patients undergoing surgical procedures requiring bowel anastomosis or strictureplasty.

Clostridium difficile Enteritis: An Early Postoperative Complication in Inflammatory Bowel Disease Patients After Colectomy

Clostridium difficile, the leading cause of hospital-acquired diarrhea, is known to cause severe colitis. C. difficile small bowel enteritis is rare (14 case reports) with mortality rates ranging from 60 to 83%. C. difficile has increased in incidence particularly among patients with inflammatory bowel disease. This case series of six patients from 2004 to 2006 is the largest in the literature. All patients received antibiotics before colectomies for ulcerative colitis and developed severe enteritis that was C. difficile toxin positive. Three patients underwent ileal pouch anal anastomosis and loop ileostomy. Four of the six patients had C. difficile colitis before colectomy. Presenting symptoms were high volume watery ileostomy output followed by ileus in five of six patients. Four of the six patients presented with fever and elevated WBC. Five of the six developed complications requiring further surgery or prolonged hospitalization. Patients were treated with intravenous hydration and metronidazole then converted to oral metronidazole and/or vancomycin. None of the patients died. A high suspicion of C. difficile enteritis in patients with inflammatory bowel disease and history of C. difficile colitis may lead to more rapid diagnosis, aggressive treatment, and improved outcomes for patients with C. difficile enteritis.

Mechanisms of Endotoxin Tolerance in Human Intestinal Microvascular Endothelial Cells

Lipopolysaccharide (endotoxin) tolerance is well described in monocytes and macrophages, but is less well characterized in endothelial cells. Because intestinal microvascular endothelial cells exhibit a strong immune response to LPS challenge and play a critical regulatory role in gut inflammation, we sought to characterize the activation response of these cells to repeated LPS exposure. Primary cultures of human intestinal microvascular endothelial cells (HIMEC) were stimulated with LPS over 6–60 h and activation was assessed using U937 leukocyte adhesion, expression of E-selectin, ICAM-1, VCAM-1, IL-6, IL-8, manganese superoxide dismutase, HLA-DR, and CD86. Effect of repeat LPS stimulation on HIMEC NF-κB and mitogen-activated protein kinase (MAPK) activation, generation of superoxide anion, and Toll-like receptor 4 expression was characterized. LPS pretreatment of HIMEC for 24–48 h significantly decreased leukocyte adhesion after subsequent LPS stimulation. LPS pretreatment inhibited expression of E-selectin, VCAM-1, IL-6, and CD86, while ICAM-1, IL-8, and HLA-DR were not altered. Manganese superoxide dismutase expression increased with repeated LPS stimulation, with a reduction in intracellular superoxide. NF-κB activation was transiently inhibited by LPS pretreatment for 6 h, but not at later time points. In contrast, p44/42 MAPK, p38 MAPK, and c-Jun N-terminal kinase activation demonstrated inhibition by LPS pretreatment 24 or 48 h prior. Toll-like receptor 4 expression on HIMEC was not altered by LPS. HIMEC exhibit endotoxin tolerance after repeat LPS exposure in vitro, characterized by diminished activation and intracellular superoxide anion concentration, and reduced leukocyte adhesion. HIMEC possess specific mechanisms of immunoregulatory hyporesponsiveness to repeated LPS exposure.

Cyclosporin A differentially inhibits multiple steps in VEGF induced angiogenesis in human microvascular endothelial cells through altered intracellular signaling

The immunosuppressive agent cyclosporin A (CsA), a calcineurin inhibitor which blocks T cell activation has provided the pharmacologic foundation for organ transplantation. CsA exerts additional effects on non-immune cell populations and may adversely effect microvascular endothelial cells, contributing to chronic rejection, a long-term clinical complication and significant cause of mortality in solid-organ transplants, including patients with small bowel allografts. Growth of new blood vessels, or angiogenesis, is a critical homeostatic mechanism in organs and tissues, and regulates vascular populations in response to physiologic requirements. We hypothesized that CsA would inhibit the angiogenic capacity of human gut microvessels. Primary cultures of human intestinal microvascular endothelial cells (HIMEC) were used to evaluate CsAs effect on four in vitro measures of angiogenesis, including endothelial stress fiber assembly, migration, proliferation and tube formation, in response to the endothelial growth factor VEGF. We characterized the effect of CsA on intracellular signaling mechanisms following VEGF stimulation. CsA affected all VEGF induced angiogenic events assessed in HIMEC. CsA differentially inhibited signaling pathways which mediated distinct steps of the angiogenic process. CsA blocked VEGF induced nuclear translocation of the transcription factor NFAT, activation of p44/42 MAPK, and partially inhibited JNK and p38 MAPK. CsA differentially affected signaling cascades in a dose dependent fashion and completely blocked expression of COX-2, which was integrally linked to HIMEC angiogenesis. These data suggest that CsA inhibits the ability of microvascular endothelial cells to undergo angiogenesis, impairing vascular homeostatic mechanisms and contributing to the vasculopathy associated with chronic rejection.