The acute toxicity of bitumen-influenced groundwaters from the oil sands region to aquatic organisms.

The extraction of surface mined bitumen from oil sands deposits in northern Alberta, Canada produces large quantities of liquid tailings waste, termed oil sands process-affected water (OSPW), which are stored in large tailings ponds. OSPW-derived chemicals from several tailings ponds migrating past containment structures and through groundwater systems pose a concern for surface water contamination. The present study investigated the toxicity of groundwater from near-field sites adjacent to a tailings pond with OPSW influence and far-field sites with only natural oil sands bitumen influence.

A preparative method for the isolation and fractionation of dissolved organic acids from bitumen-influenced waters.

The surface mining of oil sands north of Fort McMurray, Alberta produces considerable tailings waste that is stored in large tailings ponds on industrial lease sites. Viable strategies for the detoxification of oil sands process affected water (OSPW) are under investigation. In order to assess the toxic potential of the suite of dissolved organics in OSPW, a method for their extraction and fractionation was developed using solid phase extraction.

The toxicity of organic fractions from aged oil sands process-affected water to aquatic species.

The process of surface mining and extracting bitumen from oil sand produces large quantities of tailings and oil sands process-affected water (OSPW). The industry is currently storing OSPW on-site while investigating strategies for their detoxification. One such strategy relies on the biodegradation of organic compounds by indigenous microbes, resulting in aged tailings waters with reduced toxicity.

Ileocecal Anastomosis Type Significantly Influences Long-Term Functional Status, Quality of Life, and Healthcare Utilization in Postoperative Crohn's Disease Patients Independent of Inflammation Recurrence.

Objectives: Anastomotic reconstruction following intestinal resection in Crohn's disease (CD) may employ side-to-side anastomosis (STSA; anti-peristaltic orientation) or end-to-end anastomosis (ETEA). Our aim was to determine the impact of these two anastomotic techniques on long-term clinical status in postoperative CD patients.

Methods: We performed a comparative effectiveness study of prospectively collected observational data from consented CD patients undergoing their first or second ileocolonic bowel resection and re-anastomosis between 2008 and 2012, in order to assess the association between anastomosis type and 2-year postoperative quality of life (QoL), healthcare utilization, disease clinical or endoscopic recurrence, use of medications, and need for repeat resection.

Toxicity of oil sands acid-extractable organic fractions to freshwater fish: Pimephales promelas (fathead minnow) and Oryzias latipes (Japanese medaka).

The Alberta oil sands are one of the largest global petroleum deposits and, due to non-release practices for oil sands process-affected waters, produced tailings are stored in large ponds. The acid extractable organic (AEO) compounds in oil sands process-affected water are of greatest concern due to their persistence and toxicity to a variety of aquatic biota. The present study evaluated the toxicity of the five AEO fractions to two fish species: Oryzias latipes (Japanese medaka) and Pimephales promelas (fathead minnow).

Interleukin 10 Restores Gastric Emptying, Electrical Activity, and Interstitial Cells of Cajal Networks in Diabetic Mice.

Background & Aims: Gastroparesis is a complication of diabetes characterized by delayed emptying of stomach contents and accompanied by early satiety, nausea, vomiting, and pain. No safe and reliable treatments are available. Interleukin 10 (IL10) activates the M2 cytoprotective phenotype of macrophages and induces expression of heme oxygenase 1 (HO1) protein.

Assessing the bioremediation potential of algal species indigenous to oil sands process-affected waters on mixtures of oil sands acid extractable organics.

Surface mining extraction of bitumen from oil sand in Alberta, Canada results in the accumulation of oil sands process-affected water (OSPW). In attempts to maximize water recycling, and because its constituents are recognized as being toxic, OSPW is retained in settling basins. Consequently, research efforts are currently focused on developing remediation strategies capable of detoxifying OSPW to allow for eventual release.

Myocyte TLR4 enhances enteric and systemic inflammation driving late murine endotoxic ileus.

Myocytes are nonhemopoietic in origin and functionally essential in generating gastrointestinal motility. In endotoxemia, a rapid-onset nonhemopoietic mechanism potently triggers early ileus in a Toll-like receptor 4 (TLR4)/myeloid differentiation primary response gene 88 (MyD88)-dependent manner. Moreover, synergistically with hemopoietic cells, nonhemopoietic cells escalate late ileus via an IL-6 receptor-dependent inflammation-driven pathway.

Enhanced characterization of oil sands acid-extractable organics fractions using electrospray ionization-high-resolution mass spectrometry and synchronous fluorescence spectroscopy.

The open pit oil sands mining operations north of Fort McMurray, Alberta, Canada, are accumulating tailings waste at a rate approximately equal to 4.9 million m(3) /d. Naphthenic acids are among the most toxic components within tailings to aquatic life, but structural components have largely remained unidentified.

Iatrogenic extracellular matrix disruption as a local trigger for postoperative ileus.

Background: Active matrix metallopeptidase 9 (MMP-9) disruption of the extracellular matrix (ECM) plays an important role in inflammatory disorders. In this study, we investigated the inflammatory role of MMP-9 and the ECM breakdown product hyaluronan as a trigger for the postoperative intestinal inflammatory response of postoperative ileus.

Methods: We performed a standardized intestinal surgical manipulation on rats to produce ileus assessed by the oral non-digestible fluorescein isothiocyanate-dextran transit assay.

Differential molecular and cellular immune mechanisms of postoperative and LPS-induced ileus in mice and rats.

Ileus is caused by the initiation of a complex cascade of molecular and cellular inflammatory responses within the intestinal muscularis, which might be species specific. Our objective was to investigate a possible immunological divergence in the mechanisms of postoperative- and endotoxin-induced ileus in C57BL/6 mice and Sprague-Dawley rats. Gastrointestinal transit (GIT) was measured at 24 h after the injurious stimulus.

Hydrogen-enriched preservation protects the isogeneic intestinal graft and amends recipient gastric function during transplantation.

Background: Inhaled hydrogen gas exerts antioxidant and anti-inflammatory effects in rat intestinal transplantation. Here, we investigated whether ex vivo donor organ treatment with dissolved hydrogen would prevent intestinal graft injury.

Methods: Isogeneic intestinal transplantation was performed in Lewis rats with vascular flush, luminal preservation, and cold graft storage in nitrogen-bubbled (SITxN2) or hydrogen-bubbled (SITxH2) preservation solution.

Matrix metalloproteinase-9 inhibition reduces inflammation and improves motility in murine models of postoperative ileus.

Background & Aims: Matrix metalloproteinase (MMP)-9, a member of the gelatinase family of MMPs, mediates leukocyte migration during inflammation. Inflammation contributes to development of postoperative ileus (POI), which is caused by physical disturbances to the bowel during abdominal surgery. We evaluated the role of MMP-9 in POI and investigated whether disruption of MMP-9 or administration of an inhibitor of MMP-9 activity reduced cellular inflammation and bowel dysmotility in rat and mouse models of POI.

Intraesophageal manganese superoxide dismutase-plasmid liposomes ameliorates novel total-body and thoracic radiation sensitivity of NOS1-/- mice.

The effect of deletion of the nitric oxide synthase 1 gene (NOS1(-/-)) on radiosensitivity was determined. In vitro, long-term cultures of bone marrow stromal cells derived from NOS1(-/-) were more radioresistant than cells from C57BL/6NHsd (wild-type), NOS2(-/-) or NOS3(-/-) mice. Mice from each strain received 20 Gy thoracic irradiation or 9.

Dominant role of the MyD88-dependent signaling pathway in mediating early endotoxin-induced murine ileus.

TLR4 ligation by pathogen-associated molecular patterns, such as Gram-negative bacteria-derived LPS, triggers a nonhematopoietic cell-mediated ileus during early endotoxemia. Our objective was to investigate the quantitative contributions of the two downstream signaling pathways of TLR4, namely the adapter proteins myeloid differentiation primary response gene 88 (MyD88) and Toll-IL-1-resistance (TIR) domain-containing adaptor-inducing IFN-beta (TRIF). Six hours after intraperitoneal injection of highly purified LPS (UP-LPS, 5 mg/kg), in vivo gastrointestinal transit and intestinal muscularis gene transcripts of inflammatory mediators chemokine (C-X-C motif) ligand 10, synonymous IP-10 (CXCL10), granulomonocyte colony stimulating factor (GM-CSF, synonymous CSF-2), IL-1beta, IL-6, IL-10, and inducible NO synthase (iNOS) were assessed in mice with transgenic loss-of-function for MyD88 or TRIF.

CD206-positive M2 macrophages that express heme oxygenase-1 protect against diabetic gastroparesis in mice.

Background & Aims: Gastroparesis is a well-recognized complication of diabetes. In diabetics, up-regulation of heme oxygenase-1 (HO1) in gastric macrophages protects against oxidative stress-induced damage. Loss of up-regulation of HO1, the subsequent increase in oxidative stress, and loss of Kit delays gastric emptying; this effect is reversed by induction of HO1.

Nonhemopoietic cell TLR4 signaling is critical in causing early lipopolysaccharide-induced ileus.

Endotoxin-mediated ileus is poorly understood. Our objective was to mechanistically investigate the role of cell-specific TLR4 expression/signaling in causing gastrointestinal dysmotility. TLR4 chimeras and CSF-1-dependent macrophage-deficient mice were subjected to i.

IL-10 deficiency augments acute lung but not liver injury in hemorrhagic shock.

In hemorrhagic shock and trauma, patients are prone to develop systemic inflammation with remote organ dysfunction, which is thought to be caused by pro-inflammatory mediators. This study investigates the role of the immuno-modulatory cytokine IL-10 in the development of organ dysfunction following hemorrhagic shock. Male C57/BL6 and IL-10 KO mice were subjected to volume controlled hemorrhagic shock for 3h followed by resuscitation.

Interaction of hemorrhagic shock and subsequent polymicrobial sepsis on gastrointestinal motility.

Understanding "two-hit" experimental models is crucial for the rational development of therapies for hemorrhagic shock (HS). We modeled the clinical scenario of HS followed by polymicrobial sepsis (cecal ligation and puncture [CLP]) to investigate the molecular and functional alterations that occur within the gastrointestinal tract. Control, HS, CLP, simultaneous HS + CLP, and HS + delayed CLP by 24 h groups of Sprague-Dawley rats were studied for gastrointestinal transit and in vitro colonic circular muscle contractility to bethanechol.

Proinflammatory role of leukocyte-derived Egr-1 in the development of murine postoperative ileus.

Background & Aims: Early growth response gene-1 (Egr-1) is an important inflammatory transcription factor. We hypothesize that leukocyte-derived Egr-1 plays a key inflammatory role in causing postoperative ileus.

Methods: Wild-type, Egr-1 knockout, and chimera mice (constructed by irradiation followed by injection with Egr-1(+/+) or Egr-1(-/-) bone marrow) were subjected to surgical manipulation of the gastrointestinal tract to induce ileus.

Endogenous endotoxin participates in causing a panenteric inflammatory ileus after colonic surgery.

Objective: To investigate muscularis inflammation and endogenous endotoxin as causes of postoperative ileus.

Background: Postoperative inflammatory ileus of the colon is associated with a significant delay in gastrointestinal transit. We investigated whether these changes are caused by the downstream obstructive barrier of the surgically altered colon or by small intestinal muscularis inflammation itself.

Altered inflammatory gene expression underlies increased susceptibility to murine postoperative ileus with advancing age.

Susceptibility to postoperative ileus following abdominal surgery increases with advancing age. The mechanisms underlying this phenomenon are unknown. This study compares functional and molecular endpoints between young-adult (2 mo old), middle-aged (15 mo old), and elderly mice (26-30 mo old) to identify potential mechanisms.

A single intraperitoneal dose of carbon monoxide-saturated ringer's lactate solution ameliorates postoperative ileus in mice.

Treatment with inhaled carbon monoxide (CO) has been shown to ameliorate bowel dysmotility caused by surgical manipulation of the gut in experimental animals. We hypothesized that administration of CO dissolved in lactated Ringer's solution (CO-LR) might provide similar protection to that observed with the inhaled gas while obviating some of its inherent problems. Postoperative gut dysmotility (ileus) was induced in mice by surgical manipulation of the small intestine.

Leukocyte-derived inducible nitric oxide synthase mediates murine postoperative ileus.

Objective: To provide evidence that iNOS expression solely in leukocytes plays a role in postoperative ileus.

Summary Background Data: Intestinal handling initiates a molecular and cellular muscularis inflammation that has been associated with iNOS expression and ileus. The specific cellular source of iNOS is a matter of speculation.