Effect of preoperative long-term opioid therapy on patient outcomes after total knee arthroplasty: an analysis of multicentre population-based administrative data.

Background: Up to 40% of patients are receiving opioids at the time of total knee arthroplasty (TKA) in the United States despite evidence suggesting opioids are ineffective for pain associated with arthritis and have substantial risks. Our primary objective was to determine whether preoperative opioid users had worse knee pain and physical function outcomes 12 months after TKA than patients who were opioid-naive preoperatively; our secondary objective was to determine the prevalence of opioid use before and after TKA in Alberta, Canada. Methods: In this retrospective analysis of population-based data, we identified adult patients who underwent TKA between 2013 and 2015 in Alberta. We used multivariable linear regression to examine the association between preoperative opioid use and Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) pain and physical function scores 12 months after TKA, adjusting for potentially confounding variables. Results: Of the 1907 patients, 592 (31.0%) had at least 1 opioid dispensed before TKA, and 124 (6.5%) were classified as long-term opioid users. Long-term opioid users had worse adjusted WOMAC pain and physical function scores 12 months after TKA than patients who were opioid-naive preoperatively (pain score ß = 7.7, 95% confidence interval [CI] 4.0 to 11.6; physical function score ß = 7.8, 95% CI 4.0 to 11.6; p < 0.001 for both). The majority (89 ([71.8%]) of patients who were long-term opioid users preoperatively were dispensed opioids 180-360 days after TKA, compared to 158 (12.0%) patients who were opioid-naive preoperatively. Conclusion: A substantial number of patients were dispensed opioids before and after TKA, and patients who received opioids preoperatively had worse adjusted pain and functional outcome scores 12 months after TKA than patients who were opioidnaive preoperatively. These results suggest that patients prescribed opioids preoperatively should be counselled judiciously regarding expected outcomes after TKA.

Contexte: Jusqu'à 40 % des patients se font prescrire des opioïdes lors d'une chirurgie pour prothèse totale du genou (PTG) aux États-Unis, et ce, malgré des données selon lesquelles les opioïdes sont inefficaces pour la douleur associée à l'arthrite et comportent des risques substantiels. Notre objectif principal était de déterminer si les patients qui utilisaient déjà des opioïdes en période préopératoire obtenaient des résultats plus négatifs aux plans de la douleur et du fonctionnement 12 mois après leur PTG, comparativement aux patients qui ne prenaient pas d'opioïdes avant leur intervention; notre objectif secondaire était de mesurer la prévalence du recours aux opioïdes avant et après la PTG en Alberta, au Canada. Méthodes: Dans cette analyse rétrospective menée sur des données de population, nous avons identifié les patients adultes soumis à une PTG entre 2013 et 2015 en Alberta. Nous avons utilisé un modèle de régression linéaire multivarié pour examiner le lien entre l'utilisation d'opioïdes en période préopératoire et les scores de douleur et de fonctionnement à l'échelle WOMAC (Western Ontario and McMaster Universities Osteoarthritis Index) 12 mois après la PTG, en tenant compte de potentielles variables de confusion. Résultats: Sur les 1907 patients, 592 (31,0 %) ont reçu au moins 1 opioïde avant leur PTG, et 124 (6,5 %) en étaient considérés des utilisateurs de longue date. Les utilisateurs d'opioïdes de longue date présentaient de moins bons scores WOMAC ajustés pour les domaines de douleur et de fonctionnement 12 mois après la PTG, comparativement aux patients qui n'en prenaient pas avant l'intervention (score de douleur ß = 7,7, intervalle de confiance [IC] de 95 % 4,0 à 11,6; score de fonctionnement ß = 7,8, IC de 95 % 4,0 à 11,6; p < 0,001 pour les 2 domaines). La majorité (89 [71,8 %]) des patients utilisateurs d'opioïdes de longue date avant l'intervention se sont fait servir des opioïdes 180­360 jours après la PTG, comparativement à 158 patients (12,0 %) qui n'en prenaient pas avant l'intervention. Conclusion: Un nombre substantiel de patients ont reçu des opioïdes avant et après la PTG, et ceux qui en prenaient avant l'intervention présentaient des scores de douleur et de fonctionnement ajustés plus défavorables 12 mois après la PTG, comparativement aux patients qui n'en prenaient pas avant l'intervention. Selon ces résultats, il faut adresser des conseils judicieux aux patients qui sont déjà sous opioïdes en période préopératoire et les informer des résultats possibles de la PTG.

Thigh Ultrasound Used to Identify Frail Elderly Patients with Sarcopenia Undergoing Surgery: A Pilot Study.

BACKGROUND: Computed tomography (CT) scan quantifying skeletal muscle mass is the gold standard tool to identify sarcopenia. Unfortunately, high cost, limited availability, and radiation exposure limit its use. We suggest that ultrasound of the thigh muscle could be an objective, reproducible, portable, and risk-free tool, used as a surrogate to a CT scan, to help identify frail patients with sarcopenia. MATERIALS AND METHODS: We included 49 patients over 64 y old, referred to the acute care surgery service. An ultrasound of thigh muscle thickness was standardized to patient thigh length (U/Swhole/L). CT skeletal muscle index (SMI) was calculated using skeletal muscle surface area of the L3 region divided by height2. Frailty status was assessed using the Canadian Study of Healthy Aging Clinical Frailty Scale. RESULTS: The mean (SD) age was 76 (8) y, and 34% (n = 17) were men. CT-defined sarcopenia was identified in 65% (n = 11) of men and 75% (n = 24) of women. In general, women had longer stay in hospital than men (mean + SD 14 ± 9 versus 7 ± 3 d, P = 0.003). There was a significant positive correlation between thigh U/Swhole/L and CT SMI. There was an inverse correlation between thigh U/Swhole/L and frailty score; a similar relationship was observed between CT SMI and frailty. There was an association between U/Swhole/L and postoperative major complications. CONCLUSIONS: This prospective observational study illustrates that the U/Swhole/L index can be used as a surrogate to CT scan, whereby it can identify elderly frail patients with sarcopenia. Thigh ultrasound should be further tested as an objective tool to assess for stratifying frailty.

Preoperative opioid use is associated with worse patient outcomes after Total joint arthroplasty: a systematic review and meta-analysis.

BACKGROUND: A significant number of patients use opioids prior to total joint arthroplasty (TJA) in North America and there is growing concern that preoperative opioid use negatively impacts postoperative patient outcomes after surgery. This systematic review and meta-analysis evaluated the current evidence investigating the influence of preoperative opioid use on postoperative patient-reported outcomes (PRO) after total joint arthroplasty. METHODS: A systematic search was performed using Ovid, Embase, Cochrane Library, Scopus, Web of Science Core Collection, CINAHL on February 15th, 2018. Studies reporting baseline and postoperative PRO among those prescribed preoperative opioids and those who were not prior to total knee and hip arthroplasty were included. Standardized mean differences (SMD) in absolute difference and relative change in PRO measures between the two groups was calculated using random effect models. RESULTS: Six studies were included (n = 7356 patients); overall 24% of patients were prescribed preoperative opioids. Patients with preoperative opioid use had worse absolute postoperative PRO scores when compared to those with no preoperative opioid use (standardized mean difference (SMD) -0.53, 95% Confidence interval (CI) -0.75, - 0.32, p < 0.0001). When relative change in PRO score was analyzed, as measured by difference between postoperative and preoperative PRO scores, there was no group differences (SMD -0.26, 95% CI -0.56, 0.05, p = 0.10). CONCLUSION: Patients prescribed preoperative opioids may attain worse overall pain and function benefits after TJA when compared to opioid-naïve patients, but do still benefit from undergoing TJA. These results suggest preoperative opioid users should be judiciously counselled regarding potential postoperative pain and function improvements after TJA.

Incidence and predictors of postoperative delirium in the older acute care surgery population: a prospective study

Background: Among older inpatients, the highest incidence of delirium is within the surgical population. Limited data are available regarding postoperative delirium risk in the acute care surgical population. The purpose of our study was to establish the incidence of and risk factors for delirium in an older acute care surgery population. Methods: Patients aged 65 years or more who had undergone acute care surgery between April 2014 and September 2015 at 2 university-affiliated hospitals in Alberta were followed prospectively and screened for delirium by means of a validated chart review method. Delirium duration was recorded. We used separate multivariable logistic regression models to identify independent predictors for overall delirium and longer episodes of delirium (duration ≥ 48 h). Results: Of the 322 patients included, 73 (22.7%) were identified as having experienced delirium, with 49 (15.2%) experiencing longer episodes of delirium. Postoperative delirium risk factors included Foley catheter use, intestinal surgery, gallbladder surgery, appendix surgery, intensive care unit (ICU) admission and mild to moderate frailty. Risk factors for prolonged postoperative delirium included Foley catheter use and mild to moderate frailty. Surgical approach (open v. laparoscopic) and overall operative time were not found to be significant. Conclusion: In keeping with the literature, our study identified Foley catheter use, frailty and ICU admission as risk factors for delirium in older acute care surgical patients. We also identified an association between delirium risk and the specific surgical procedure performed. Understanding these risk factors can assist in prevention and directed interventions for this high-risk population.

Contexte: Parmi les patients âgés, l'incidence la plus élevée d'épisodes de délire s'observe chez les patients opérés. On dispose de données limitées au sujet du risque de délire postopératoire chez les patients soumis à une chirurgie d'urgence. Le but de notre étude était de connaître l'incidence des épisodes de délire et les facteurs de risque chez la population âgée soumise à une chirurgie d'urgence. Méthodes: Nous avons suivi de façon prospective les patients de 65 ans ou plus soumis à une chirurgie d'urgence entre avril 2014 et septembre 2015 dans 2 centres hospitaliers universitaires de l'Alberta et nous avons recensé les épisodes de délire au moyen d'une méthode validée d'analyse des dossiers. La durée des épisodes de délire a été notée. Nous avons utilisé des modèles séparés d'analyse de régression logistique multivariée pour dégager les prédicteurs indépendants des épisodes globaux de délire et des épisodes plus longs (durée ≥ 48 h). Résultats: Parmi les 322 patients inclus, 73 (22,7 %) ont manifesté un épisode de délire, dont 49 (15,2 %) un épisode plus long. Les facteurs de risque à l'égard des épisodes de délire postopératoire ont inclus : l'emploi d'une sonde Foley, la chirurgie intestinale, la chirurgie de la vésicule biliaire, l'appendicectomie, un séjour à l'unité de soins intensifs (USI) et un état de fragilité léger ou modéré. Les facteurs de risque à l'égard d'un épisode de délire postopératoire prolongé ont inclus : l'emploi d'une sonde Foley et un état de fragilité léger ou modéré. L'approche chirurgicale (ouverte c. laparoscopique) et la durée globale de l'intervention n'ont pas joué un rôle significatif. Conclusion: Faisant écho à la littérature publiée, notre étude a identifié l'emploi de la sonde Foley, l'état de fragilité et le séjour à l'USI comme des facteurs de risque de délire chez les patients âgés soumis à une chirurgie d'urgence. Nous avons aussi observé un lien entre le risque de délire et certains types d'interventions chirurgicales. En comprenant mieux ces facteurs, il sera possible de prévenir ces épisodes et d'orienter les interventions chez cette population à risque élevé.

Impact of frailty on outcomes after discharge in older surgical patients: a prospective cohort study.

BACKGROUND: Frailty is a state of vulnerability to diverse stressors. We assessed the impact of frailty on outcomes after discharge in older surgical patients. METHODS: We prospectively followed patients 65 years of age or older who underwent emergency abdominal surgery at either of 2 tertiary care centres and who needed assistance with fewer than 3 activities of daily living. Preadmission frailty was defined according to the Canadian Study of Health and Aging Clinical Frailty Scale as "well" (score 1 or 2), "vulnerable" (score 3 or 4) or "frail" (score 5 or 6). We assessed composite end points of 30-day and 6-month all-cause readmission or death by multivariable logistic regression. RESULTS: Of 308 patients (median age 75 [range 65-94] yr, median Clinical Frailty Score 3 [range 1-6]), 168 (54.5%) were classified as vulnerable and 68 (22.1%) as frail. Ten (4.2%) of those classified as vulnerable or frail received a geriatric consultation. At 30 days after discharge, the proportions of patients who were readmitted or had died were greater among vulnerable patients (n = 27 [16.1%]; adjusted odds ratio [OR] 4.60, 95% confidence interval [CI] 1.29-16.45) and frail patients (n = 12 [17.6%]; adjusted OR 4.51, 95% CI 1.13-17.94) than among patients who were well (n = 3 [4.2%]). By 6 months, the degree of frailty independently and dose-dependently predicted readmission or death: 56 (33.3%) of the vulnerable patients (adjusted OR 2.15, 95% CI 1.01-4.55) and 37 (54.4%) of the frail patients (adjusted OR 3.27, 95% CI 1.32-8.12) were readmitted or had died, compared with 11 (15.3%) of the patients who were well. INTERPRETATION: Vulnerability and frailty were prevalent in older patients undergoing surgery and unlikely to trigger specialized geriatric assessment, yet remained independently associated with greater risk of readmission for as long as 6 months after discharge. Therefore, the degree of frailty has important prognostic value for readmission. TRIAL REGISTRATION FOR PRIMARY STUDY: ClinicalTrials.gov, no. NCT02233153.

Creatine-loading preserves intestinal barrier function during organ preservation.

We have developed a novel, intraluminal preservation solution that is tailored to the metabolic requirements of the intestine. This organ-specific solution addresses many of the problems associated with low temperature organ storage including energy, oxidative and osmotic stresses. However, conservation of energy levels remains one of the most difficult obstacles to overcome due to the inherent sensitivity of the mucosa to ischemia. Creatine-loading has become a popular and scientifically proven method of augmenting energy reserves in athletes performing anaerobic burst work activities. We hypothesized that if we could develop a method that was able to augment cellular energy levels, the structure and function of the mucosa would be more effectively preserved. The purpose of this study was to determine if creatine-loading is a feasible and effective strategy for preserving the intestine. Our data indicate that creatine loading has significant impact on energy levels during storage with corresponding improvements in mucosal structure and function. Both of our rodent models, a) continuous perfusion for 4 h and b) a single flush with our intraluminal preservation solution supplemented with 50 mM creatine, demonstrated significant improvements in creatine phosphate, ATP, Energy Charge and ATP/AMP following cold storage (P < 0.05). Notably, after 10 h creatine phosphate was 324% greater in Creatine-treated tissues compared to Controls (P < 0.05). Preferential utilization of glutathione in the Creatine group was effective at controlling oxidative injury after 10 h storage (P < 0.05). Improvements in barrier function and electrophysiology with creatine-treatment reflected superior mucosal integrity after 10 h storage; Permeability and Transepithelial resistance measurements remained at fresh tissue values. This was in stark contrast to Control tissues in which permeability rose to >300% of fresh tissue values (P < 0.005) and transepithelial resistance dropped by 95% (P < 0.005). After 10 h storage, Park's grading of histologic injury reflected extensive villus denudation (grade 4) in control tissues compared to healthy tissue (grade 0) in the Creatine group. This study demonstrates that a strategy of creatine supplementation of our intraluminal preservation solution facilitates the preservation of the intestinal mucosa during storage.

Analysis of postdischarge costs following emergent general surgery in elderly patients.

BACKGROUND: As populations age, more elderly patients will undergo surgery. Frailty and complications are considered to increase in-hospital cost in older adults, but little is known on costs following discharge, particularly those borne by the patient. We examined risk factors for increased cost and the type of costs accrued following discharge in elderly surgical patients. METHODS: Acute abdominal surgery patients aged 65 years and older were prospectively enrolled. We assessed baseline clinical characteristics, including Clinical Frailty Scale (CFS) scores. We calculated 6-month cost (in Canadian dollars) from patient-reported use following discharge according to the validated Health Resource Utilization Inventory. Primary outcomes were 6-month overall cost and cost for health care services, medical products and lost productive hours. Outcomes were log-transformed and assessed in multivariable generalized linear and zero-inflated negative binomial regressions and can be interpreted as adjusted ratios (AR). Complications were assessed according to Clavien-Dindo classification. RESULTS: We included 150 patients (mean age 75.5 ± 7.6 yr; 54.1% men) in our analysis; 10.8% had major and 43.2% had minor complications postoperatively. The median 6-month overall cost was $496 (interquartile range $140-$1948). Disaggregated by cost type, frailty independently predicted increasing costs of health care services (AR 1.76, 95% confidence interval [CI] 1.43-2.18, p < 0.001) and medical products (AR 1.61, 95% CI 1.15-2.25, p = 0.005), but decreasing costs in lost productive hours (AR 0.39, p = 0.002). Complications did not predict increased cost. CONCLUSION: Frail patients accrued higher health care services and product costs, but lower costs from lost productive hours. Interventions in elderly surgical patients should consider patient-borne cost in older adults and lost productivity in less frail patients. TRIAL REGISTRATION: NCT02233153 (clinicaltrials.gov).

CONTEXTE: Avec le vieillissement de la population, les personnes âgées seront plus nombreuses à subir des chirurgies. Il est déjà reconnu que la fragilité et les complications font augmenter les coûts d'hospitalisation chez les adultes âgés, mais on en sait relativement peu sur les coûts posthospitaliers, particulièrement ceux assumés par le patient lui-même. Nous avons analysé les facteurs de risque d'augmentation de ces coûts et les types de dépenses assumées après le congé par les patients âgés opérés. MÉTHODES: Pour l'étude, nous avons recruté des patients de 65 ans et plus qui allaient subir une chirurgie abdominale d'urgence. Nous avons déterminé leurs caractéristiques cliniques initiales, y compris leur score à l'échelle de fragilité clinique (EFC). Nous avons calculé les coûts échelonnés sur 6 mois (en dollars canadiens) rapportés par les patients après leur congé, selon un inventaire validé de l'utilisation des ressources de santé. Les paramètres principaux étaient le montant total des dépenses et le coût des services de santé, des produits médicaux et des heures de travail perdues pour une période de 6 mois. Une transformation logarithmique a été appliquée aux données, qui ont été évaluées par une analyse de régression linéaire multivariée généralisée et par une analyse binomiale négative avec surreprésentation des zéros. Les résultats peuvent être interprétés comme des rapports ajustés (RA). Les complications ont été évaluées selon la classification de Clavien-Dindo. RÉSULTATS: Nous avons inclus 150 patients dans notre analyse (âge moyen : 75,5 ± 7,6 ans; proportion d'hommes : 54,1 %). Après l'opération, 10,8 % ont présenté des complications majeures, et 43,2 %, des complications mineures. Le montant total médian des dépenses sur 6 mois était de 496 $ (éventail interquartile : 140-1948 $). Dans des analyses effectuées selon le type de dépenses, la fragilité était une variable explicative permettant de prédire indépendamment l'accroissement des coûts des services de santé (RA : 1,76; intervalle de confiance [IC] à 95 % : 1,43-2,18; p < 0,001) et des produits médicaux (RA : 1,61; IC à 95 % : 1,15-2,25; p = 0,005) ainsi que la réduction des coûts associés aux heures de travail perdues (RA : 0,39; p = 0,002). Les complications n'avaient pas de valeur prédictive en ce qui a trait à l'accroissement des coûts. CONCLUSION: Les patients fragiles ont assumé des coûts plus élevés en services de santé et en produits médicaux, mais des coûts moindres en lien avec la perte d'heures de travail. Les interventions chez les patients en chirurgie âgés devraient tenir compte des coûts assumés par cette population et de la perte de productivité chez les patients moins fragiles. ENREGISTREMENTDEL'ESSAI: ClinicalTrials.gov, no NCT02233153.

Urine intestinal fatty acid-binding protein predicts acute mesenteric ischemia in patients.

BACKGROUND: Acute mesenteric ischemia (AMI) has a high morbidity and mortality and often presents as a diagnostic challenge. Currently, there is no blood, urine, or radiologic tests that provide a definitive diagnosis of AMI. The aim of this study was to evaluate the clinical accuracy of urine intestinal fatty acid-binding protein (I-FABP) to diagnosis AMI. MATERIALS AND METHODS: Twenty patients referred to the Acute Care Surgery service at University of Alberta Hospital with suspected AMI taken to the operating room for definitive diagnosis were recruited. Pathologic findings from surgical specimens confirmed a gold standard diagnosis for intestinal ischemia. The patients found to be nonischemic became the internal controls. Conventional clinical markers were examined in blood including white blood cell count, lactate, and creatinine. Blood was also examined by enzyme-linked immunosorbent assays (ELISAs) for I-FABP and interleukin-6. Urine was examined preoperatively and 6 and 24 h postoperatively for I-FABP. RESULTS: Thirteen patients were pathologically diagnosed with AMI while five patients were nonischemic; two were excluded due to missing biologic specimens. There was no difference in age or gender between ischemic and nonischemic patients (56 ± 5 versus 66 ± 11 years old, respectively; six females with ischemic and three females in the nonischemic group). There was no difference in serum lactate and creatinine between the two groups. Serum interleukin-6 levels in patients with AMI were significantly higher than nonischemic controls (0.4 ± 0.2 ng/mL versus 0.2 ± 0.07 ng/mL, respectively, P = 0.03). There was a nonstatistically significant increase in serum I-FABP in AMI patients compared to internal controls (9 ± 3 ng/mL versus 2.4 ± 0.9 ng/mL, respectively, P = 0.2). Urine I-FABP was significantly higher in patients diagnosed with AMI than in controls (7 ± 1 ng/mL versus 2 ± 1 ng/mL, respectively, P = 0.007). The receiver operating characteristic curve illustrated that urine I-FABP discriminates significantly between patients with AMI and controls (area under receiver operating characteristic = 0.88, P = 0.03). CONCLUSIONS: The traditional clinical markers lactate and white blood cell count were not able to differentiate AMI from nonischemic bowel. However, we found that urine I-FABP was a noninvasive biomarker with high specificity and sensitivity for accurately diagnosing AMI in patients. A noninvasive accurate tool for AMI would facilitate for a rapid treatment, while preventing unnecessary surgical interventions in high-risk patient populations.

Additive effect of sirolimus and anti-death receptor 5 agonistic antibody against hepatocellular carcinoma.

BACKGROUND & AIMS: Despite careful patient selection, hepatocellular carcinoma (HCC) recurs in 10-20% of cases after liver transplantation, and the use of potent adjuvant anticancer drugs would be welcome. The aim of this study was to evaluate the efficiency of a combined therapy of rapamycin (sirolimus) and anti-death receptor (DR)5 monoclonal antibody (mAb) on HCC. METHODS: We first assessed the side effects of anti-DR5 mAb administration in vivo by giving various doses of anti-DR5 mAb. Cell proliferation assays were then performed using mouse Hepa1-6 cells or human Huh7 cells to quantify the relative cell viability under various concentrations of sirolimus, anti-DR5 mAb or a combination. Next, one million Hepa1-6 cells were transplanted into C.B17-SCID-beige mice subcutaneously, and four groups were created: (1) untreated, (2) anti-DR5 mAb alone, (3) sirolimus alone and (4) anti-DR5 mAb + sirolimus. RESULTS: Anti-DR5 mAb (200 and 300 µg/day) induced liver dysfunction with partial necrosis of the liver, but 100 µg/day was well tolerated with transaminitis, but normal bilirubin and only minor histological liver damage. In vitro, anti-DR5 mAb lysed Hepa1-6 and Huh7 cells in a dose-dependent manner, and combinations of sirolimus and anti-DR5 mAb demonstrated an additive effect. In vivo studies demonstrated that tumour sizes were significantly smaller in the combined therapy group than in the monotherapy groups. CONCLUSIONS: Combining sirolimus and low-dose anti-DR5 mAb has a significant effect against HCC. This strategy represents a potential novel approach for the management of HCC.

Human cytomegalovirus infection in humanized liver chimeric mice.

AIM: Cytomegalovirus is a common viral pathogen that influences the outcome of organ transplantation. To date, there is no established method to evaluate the effects of human CMV (HCMV) treatments in vivo except for human clinical trials. In the current study, we describe the development of a mouse model that supports the in vivo propagation of HCMV. METHODS: One million viable human hepatocytes, purified from human livers, were injected into the spleens of severe combined immunodeficient/albumin linked-urokinase type plasminogen activator transgenic mice. A clinical strain of HCMV was inoculated in mice with confirmed human hepatocyte engraftment or in non-chimeric controls. Infection was monitored through HCMV titers in the plasma. Mice were administrated ganciclovir (50 mg/kg per day, i.p.) beginning at 2 days post-HCMV inoculation, or human liver natural killer (NK) cells (20 × 10(6) cells/mouse, i.v.) 1 day prior to HCMV inoculation. RESULTS: Chimeric mice that received HCMV showed high plasma titers of HCMV DNA on days 1 and 6 that became undetectable by day 11 post-inoculation. In contrast, non-transplanted mice had only residual plasma inoculum detection at day 1 and no detectable viremia thereafter. The levels of HCMV DNA were reduced by ganciclovir treatment or by human liver NK cell adoptive transfer, while HCMV-infected chimeric mice that were not treated sustained viremia during the follow up. CONCLUSION: Human liver chimeric mice provide an in vivo model for the study of acute HCMV infection of hepatocytes.

Oncostatin M Receptor Type II Knockout Mitigates Inflammation and Improves Survival from Sepsis in Mice.

Sepsis remains one of the leading causes of death worldwide. Oncostatin M (OSM), an interleukin (IL)-6 family cytokine, can be found at high levels in septic patients. However, little is known about its role in sepsis. This study aimed to determine if the genetic knockout of OSM receptor (OSMR) type II signaling would improve survival in a murine model of sepsis. Aged (>50 weeks) OSMR type II knockout (KO) mice and wild-type (WT) littermates received an intraperitoneal injection of fecal slurry (FS) or vehicle. The KO mice had better survival 48 h after the injection of FS than the WT mice (p = 0.005). Eighteen hours post-FS injection, the KO mice had reduced peritoneal, serum, and tissue cytokine levels (including IL-1ß, IL-6, TNFα, KG/GRO, and IL-10) compared to the WT mice (p < 0.001 for all). Flow cytometry revealed decreased recruitment of CD11b+ F4/80+ Ly6chigh+ macrophages in the peritoneum of KO mice compared to WT mice (34 ± 6 vs. 4 ± 3%, PInt = 0.005). Isolated peritoneal macrophages from aged KO mice had better live E. coli killing capacity than those from WT mice (p < 0.001). Peritoneal lavage revealed greater bacterial counts in KO mice than in WT mice (KO: 305 ± 22 vs. 116 ± 6 CFU (×109)/mL; p < 0.001). In summary, deficiency in OSMR type II receptor signaling provided a survival benefit in the progression of sepsis. This coincided with reduced serum levels of pro-inflammatory (IL-1ß, TNFα, and KC/GRO) and anti-inflammatory markers (IL-10), increased bacterial killing ability of macrophages, and reduced macrophage infiltration into to site of infection.

Small bowel fibrosis and systemic inflammatory response after ileocolonic anastomosis in IL-10 null mice.

BACKGROUND: Crohn's disease recurrence after an ileocecal resection is common; yet, its pathophysiology is poorly understood and available treatment is suboptimal. The purpose of this study was to examine the bacterial, local, and systemic immune changes that follow ileocolonic anastomosis in a rodent model of Crohn's disease, the interleukin-10 gene-deficient (IL-10 null) mice. MATERIALS AND METHODS: We divided wild-type and IL-10 null mice into three treatment groups: ileocolonic anastomosis, sham operation (ileo-ileal anastomosis), and control group without an operation. We sacrificed mice at 6 and 15 wks after the operation. At 6 wks, we assessed bacterial changes using the denaturing gel electrophoresis and similarity coefficient calculation. At both time points, we examined the small bowel for inflammation and fibrosis with histology. We measured the interferon gamma secretion by splenocytes stimulated with gastrointestinal bacterial antigens and splenocyte composition as a marker of systemic response. RESULTS: At 6 wks, ileocolonic anastomosis resulted in increased similarity in bacterial species between the ileum and colon. The ileocolonic anastomosis did not lead to significant inflammation in the small intestine, but it resulted in an increased collagen deposition in all animals undergoing surgery, the most pronounced fibrosis of which was present in IL-10 null mice 15 wks after ileocolonic anastomosis. Furthermore, this was associated with significantly increased interferon gamma secretion by bacterial antigen-stimulated splenocytes and a decreased number of CD11+ cells in the same experimental group. CONCLUSIONS: Ileocolonic anastomosis leads to bacterial changes in the terminal ileum. In the genetically susceptible host, it is associated with small bowel fibrosis and systemic immune alterations. The composition of immune cells in the spleen is altered and splenocytes hypersecrete proinflammatory cytokine (interferon gamma) when challenged with gastrointestinal bacterial antigens.

Intravenous injection of endogenous microbial components abrogates DSS-induced colitis.

BACKGROUND: The etiology of inflammatory bowel diseases (IBD) is largely unknown, but appears to be perpetuated by uncontrolled responses to antigenic components of the endogenous flora. Tolerance to antigenic stimulation can be achieved by exposure to a given antigen in high amounts (high dose tolerance). Colitis induced by feeding of Dextran Sodium Sulfate (DSS) is an often-used animal model mimicking clinical and histological features of human IBD. AIMS: We investigated whether treatment with high doses of endogenous bacterial components can affect the response to these antigenic components and thus impact the course of the inflammatory response induced by DSS. METHODS: 129/SvEv mice were injected intravenously in the tail vein with lysates prepared from fecal material of conventionally-raised mice. Control mice received a solution of bacterial antigen-free lysates prepared from fecal material of germ-free mice. Seven days later, colitis was induced in these mice by introducing DSS (3.5%) in the drinking water for 5 days. Onset and course of the inflammatory response was monitored by assessment of weight loss. Mice were sacrificed at day 7 post colitis induction and tested for histopathologic injury, intestinal cytokine release, and systemic response to bacterial antigens. RESULTS: Intravenous injection with fecal lysates reduced intestinal and antigen-stimulated systemic pro-inflammatory cytokine release and prevented DSS-induced weight loss and intestinal injury. CONCLUSION: Pretreatment with high amount of endogenous bacterial components has a profound tolerogenic effect on the systemic and mucosal immune responses resulting in reduced intestinal inflammation and abrogates colitis-induced weight loss.

Factors affecting hepatocyte isolation, engraftment, and replication in an in vivo model.

Human hepatocyte transplantation is an alternative treatment for acute liver failure and liver diseases involving enzyme deficiencies. Although it has been successfully applied in selected recipients, both isolation and transplantation outcomes have the potential to be improved by better donor selection. This study assessed the impact of various donor variables on isolation outcomes (yield and viability) and posttransplant engraftment, using the SCID/Alb-uPA (severe combined immunodeficient/urokinase type plasminogen activator under the control of an albumin promoter) human liver chimeric mouse model. Human hepatocytes were obtained from 90 human liver donor specimens and were transplanted into 3942 mice. Multivariate analysis revealed improved viability with younger donors (P = 0.038) as well as with shorter warm ischemic time (P = 0.012). Hepatocyte engraftment, assessed by the posttransplant level of serum human alpha1-antitrypsin, was improved with shorter warm ischemia time. Hepatocytes isolated from older donors (>or=60 years) had lower viability and posttransplant engraftment (P

Critical role of natural killer cells in the rejection of human hepatocytes after xenotransplantation into immunodeficient mice.

The severe combined immunodeficiency/albumin linked-urokinase type plasminogen activator (SCID/Alb-uPA) human liver chimeric mouse model has added a new dimension to studies of liver based human diseases and has important potential for study of human hepatic drug metabolism. However, it remains unclear if natural killer (NK) cell in SCID/Alb-uPA mice has an important negative impact on engraftment and expansion of human hepatocytes after transplantation. Here, we explore the role of mouse NK cells in the rejection of transplanted human hepatocytes in SCID/Alb-uPA mice. We assessed NK cell activity in vivo, using (125)I-iodo-2'-deoxyuridine incorporation assay. Low serum human alpha-1 antitrypsin (hAAT, <10 microg/ml) recipients, representing graft failure, showed resistance to engraftment of MHC class I knockout marrow (indicating high NK cell activity), while NK cell-depleted low hAAT recipients and high hAAT (>100 microg/ml) recipients accepted MHC class I knockout marrow, indicating a correlation between low NK cell activity, in vivo, and high level human hepatocyte engraftment. We also showed that higher level engraftment of human hepatocytes was achieved in both NK cell-depleted SCID/Alb-uPA mice and Rag2(-/-)gammac(-/-)/Alb-uPA (T,B and NK cell deficient) mice compared with untreated SCID/Alb-uPA mice. These results support a critical role for mouse NK cells in the rejection of human hepatocytes xenotransplanted to immunodeficient mice.

Oral administration of curcumin emulsified in carboxymethyl cellulose has a potent anti-inflammatory effect in the IL-10 gene-deficient mouse model of IBD.

Curcumin is a tumeric-derived, water-insoluble polyphenol with potential beneficial health effects for humans. It has been shown to have preventive as well as therapeutic effects in chemically induced murine models of colitis. To investigate whether curcumin exerts a similar effect on the spontaneous colitis in interleukin (IL)-10 gene-deficient mice, we gavaged these mice daily for 2 weeks with 200 mg/kg per day curcumin emulsified in carboxymethyl cellulose, a food additive generally used as a viscosity modifier. Mice fed the curcumin/carboxymethyl cellulose mixture and those receiving carboxymethyl cellulose alone demonstrated similar reductions in histological injury score and colon weight/length ratio compared to water-fed controls. However, significant reductions in pro-inflammatory cytokine release in intestinal explant cultures were only seen in mice treated with the curcumin mixture. Our data demonstrate that in IL-10 gene-deficient mice, both oral curcumin and carboxymethyl cellulose, appear to have modifying effects on colitis. However, curcumin has additional anti-inflammatory effects mediated through a reduced production of potent pro-inflammatory mucosal cytokines.

Optimizing the concentration of hydroxyethylstarch in a novel intestinal-specific preservation solution.

INTRODUCTION: Our lab has developed an effective nutrient-rich solution that facilitates energy production and control of oxidative stress during static cold storage of the intestine; however, the requirement for oncotic agents, such as hydroxyethylstarch (HES), has not been evaluated. This study investigated the effectiveness and requirement for HES in an intraluminal preservation solution during a clinically relevant period of cold storage. METHODS: Rat intestines were procured, including an intravascular flush with University of Wisconsin solution followed by a 'back table' intraluminal flush with a nutrient-rich preservation solution containing varying amounts of HES (n=6 per group): Group 1, 0%; Group 2, 2.5%; Group 3, 5%; Group 4, 10%. Energetics, oxidative stress, and morphology were assessed over a 24h time-course of cold storage. RESULTS: Overall, the 5% HES solution, Group 3, demonstrated superior energetic status (ATP and total adenylates) compared to all groups, P<0.05. Malondialdehyde levels indicated a reduction in oxidative stress in Groups 3 and 4 (P<0.05). After 12h, median modified Parks' grades for Groups 2 and 3 were significantly lower than Groups 1 and 4, P<0.05. CONCLUSION: Our data suggests that when employing an intraluminal preservation solution for static organ storage, oncotic support is a fundamental requirement; 5% HES is optimal.

Comparing the effects of Dextran 70 and Hydroxyethyl starch in an intestinal storage solution.

INTRODUCTION: Our lab has developed a novel strategy for intestinal preservation involving the intraluminal delivery of a nutrient-rich preservation solution. The aim of this study was to compare the effectiveness of two impermeant agents for use in our solution: Dextran 70 (D70; Mw=70 kDa) and Hydroxyethyl starch (HES; Mw=2200 kDa). METHODS: Rat intestines were procured, including an intravascular flush with University of Wisconsin solution followed by a 'backtable' intraluminal flush with: UW solution (group 1, UW), or an amino acid-based nutrient-rich preservation solution (AA solution) containing either 5% D70 (group 2, AA-D70) or HES (group 3, AA-HES). Tissue samples (n=6) were taken at 2, 4, 8, and 12 h cold storage; histology, energetic, end-product, and oxidative parameters were assessed. In separate groups (n=4), D70 and HES were fluorescently labeled with fluorescein isothiocyanate (FITC) in order to directly observe mucosal penetration of the starch and dextran. RESULTS: Over the 12 h storage time-course, direct visualization of the fluorescently labeled D70 showed penetration of the mucosal layer as early as 2 h and progressively continued to do so throughout the 12 h period. In contrast, HES did not cross the mucosal barrier and remained captive within the lumen. As time of storage progressed, grade of injury increased in all groups, however, at 4 and 12 h the AA-HES treated tissues exhibited significantly less injury compared to UW and AA-D70, P < 0.05. AA-HES group showed on moderate villus clefting (median grade 2; P < 0.05) while the AA-D70 group exhibited complete villus denudation (grade 4) and the UW group had extensive injury into the regenerative cryptal regions (grade 6). Metabolic parameters revealed a preferential maintenance of ATP and Energy Charge; increases in lactate, alanine and ammonium supported the involvement of aerobic and anaerobic pathways for energy production. CONCLUSION: The results of this study challenge the idea that oncotic support is not a fundamental requirement of static organ storage. Furthermore, our data suggests that HES is an effective oncotic agent for use in our intraluminal nutrient-rich preservation solution, while Dextran 70 is not.

Oncostatin M Plays a Critical Role in Survival after Acute Intestinal Ischemia: Reperfusion Injury.

Background: Acute intestinal ischemia-reperfusion injury (AIIRI) is a devastating clinical condition relevant to multiple diseases processes, including sepsis, trauma, transplantation, and burns. An AIIRI is a contributor to the development of multiple organ dysfunction syndrome (MODS). Oncostatin M (OSM)/oncostatin M receptor (OSMR) signaling is an unrecognized and novel candidate pathway for the mediation of MODS. In this study, we hypothesized that OSM mediates the injury mechanism of AIIRI leading to MODS. Methods: Wild-type (WT) and OSMR-knockout (OSMR-/-) C57BL/6 mice underwent AIIRI using a well-established model of selective occlusion of the superior mesenteric artery (SMA). Serum cytokine concentrations were measured using a multiplex detection system. Further tissue analysis was conducted with polymerase chain reaction, enzyme-linked immunosorbent assay, Western blots, and histologic review. Results: Survival was significantly higher in WT than in OSMR-/- groups at 30 minutes of ischemia with 2 hours of reperfusion (100% versus 42.9%; P = 0.015). No significant differences in the degree of local intestinal injury was seen in the two groups. In contrast, the degree of lung injury, as evidenced by myeloperixodase activity, was lower in OSMR-/- animals in the early AIIRI groups. There was a greater degree of renal dysfunction in OSMR-/- mice. Oncostatin M mediated interleukin (IL)-10 upregulation, with WT animals having significantly lower IL-10 concentrations (52.04 ± 23.06 pg/mL versus 324.37 ± 140.35 pg/mL; P = 0.046). Conclusion: Oncostatin M signalling is essential during acute intestinal ischemia-reperfusion injury. An OSMR deficiency results in decreased early lung injury but increased renal dysfunction. There was a significantly increased mortality rate after AIIRI in mice with OSMR deficiency. Augmentation of OSM may be a novel immunomodulatory strategy for AIIRI.

Alleviating intestinal ischemia-reperfusion injury in an in vivo large animal model: developing an organ-specific preservation solution.

INTRODUCTION: This study investigated the role of a novel nutrient-rich preservation solution in alleviating intestinal ischemia-reperfusion (IR) injury in a large animal model. MATERIALS AND METHODS: Porcine intestines were treated in vivo with the following intraluminal flush solutions: group 1, none; group 2, University of Wisconsin solution; group 3, an amino acid-based solution, previously shown to be effective in reducing IR injury in rodent models. Intestinal ischemia was induced in vivo for 60 min, followed by 180 min reperfusion. Key metabolic aspects were assessed in relation to two fundamental kinase mechanisms that govern cell fate, AMP kinase, and Jun kinase. RESULTS: After 180 min reperfusion, groups 1 and 2 exhibited clefting, denudation, and mucosal hemorrhage, whereas injury was markedly reduced in group 3 (median grades 4.5 and 5 vs. 0; P<0.05). In contrast to groups 1 and 2, group 3 tissues exhibited a full recovery of adenylates (ATP, total adenylates) and an effective control of oxidative stress throughout reperfusion. Neutrophil-mediated inflammation was abrogated in group 3. An up-regulation of two key enzymes (glutaminase and alanine aminotransferase) provided a mechanism for the superior recovery of energetics and the preservation of mucosal integrity in group 3. A strong activation of AMP-activated protein kinase resulting in the up-regulation of a primary proapoptotic kinase mechanism, Jun kinase, was evident in groups 1 and 2. DISCUSSION: A strategy of intraluminal administration of a nutrient-rich solution represents a potential therapy for alleviating intestinal IR injury; these findings suggest a more effective method for the ischemic storage of intestine.