Interferon regulatory factor-1 down-regulates cytokine-induced IP-10 expression in pancreatic islets.

BACKGROUND: Interferon (IFN)-gamma acts synergistically with interleukin (IL)-1beta and tumor necrosis factor (TNF)-alpha to activate isoform of nitric oxide synthetase (iNOS) gene expression, induce apoptosis, and impair glucose-stimulated insulin release (GSIR) in pancreatic islets. This effect is an important mechanism of islet dysfunction in models of pancreatitis, type I diabetes, and islet allograft rejection. We tested the hypothesis that transcription factor interferon regulatory factor (IRF)-1 plays a regulatory role in both this cytokine-induced islet injury and cytokine-induced gene expression for chemotactic chemokines. METHODS: Isolated islets from wild-type (WT) or IRF-1(-/-) C57BL/6 mice were cultured in a mixture of IL-1beta, TNF-alpha, and IFN-gamma +/- the iNOS inhibitor L-NMMA. The following end points were assessed: i) GSIR; ii) rates of apoptosis; and iii) gene expression for iNOS, IRF-1 and inducible protein (IP)-10, monocyte chemoattractive protein (MCP)-1, macrophage inflammatory protein-1alpha, and macrophage inflammatory protein-1beta. RESULTS: Cytokine-treated WT islets demonstrated an increase in IRF-1 and iNOS gene expression, inhibition of GSIR, increased rates of apoptosis, and increased gene transcription and protein release for IP-10 and MCP-1. Cytokine-treated IRF-1(-/-) islets demonstrated relatively less iNOS gene expression, preserved GSIR, reduced rates of apoptosis, and a more marked increase in transcription for IP-10 and MCP-1 and in IP-10 protein release. L-NMMA-cotreated WT islets were completely resistant to cytokine-induced dysfunction and apoptosis but demonstrated the same degree of cytokine-induced chemokine gene expression as cytokine-treated WT without L-NMMA. CONCLUSIONS: IFN-gamma, IL-1beta, and TNF-alpha in combination induce chemokine gene expression in pancreatic islets. Transcription factor IRF-1 mediates cytokine-induced islet dysfunction, apoptosis, and iNOS gene expression but down-regulates IP-10 gene expression.

Genetic deletion of chemokine receptor CXCR3 or antibody blockade of its ligand IP-10 modulates posttransplantation graft-site lymphocytic infiltrates and prolongs functional graft survival in pancreatic islet allograft recipients.

BACKGROUND: Interaction of chemokine receptor CXCR3 with its ligand IP-10 mediates effector cell trafficking to sites of allograft rejection in murine models of whole organ allotransplantation. We hypothesized that blocking the CXCR3/IP-10 interaction would impair posttransplantation leukocyte trafficking to and delay rejection of pancreatic islet allografts. METHODS: A/J strain murine islets were implanted to the kidney capsule of H-2 disparate, streptozotocin-induced diabetic wild type (WT), CXCR3 deficient (CXCR3(-/-)) or IP-10 antibody-treated WT (alphaIP-10) C57BL/6 recipients. Representative grafts from each group were harvested at day 7. Ribonuclease protection assay was used to determine gene expression for cell markers F4/80 (macrophages), CD8 (type I T cells), CD4 (type II T cells), and CD 19 (natural killer cells), and for chemokines IP-10, MIP-1alpha, MIP-1beta, MCP-1, and RANTES. Immunohistochemistry was used to confirm ribonuclease protection assay infiltrate data. Graft-site chemokine gene expression and cellular infiltrate were correlated with time to functional graft rejection. RESULTS: Untreated WT recipients demonstrated heavy graft-site cell infiltrates and increased graft-site gene expression for cell markers F4/80, CD8, CD4, and CD19, and for chemokines RANTES, IP-10, and MIP-1beta at day 7. In comparison with untreated WT, alphaIP-10-treated WT and CXCR3(-/-) recipients demonstrated the same degree of chemokine gene expression but less lymphocytic infiltrate. The mean length of allograft survival was 12.7 +/- 3.1 days in untreated WT versus 20.2 +/- 2.7 days (P <.05) for CXCR3(-/-)- and 19.7 +/- 2.3 days (P <.05) for alphaIP-10-treated WT recipients. CONCLUSIONS: CXCR3 gene deletion or alphaIP-10 antibody therapy modulates posttransplantation lymphocytic graft infiltration and statistically prolongs graft survival in murine islet allograft recipients.

Prospective study of colorectal enhanced recovery after surgery in a community hospital.

IMPORTANCE: Enhanced recovery after surgery (ERAS) colorectal programs have shown to be successful at reducing length of stay in many international and academic centers; however, their efficacy in a community hospital setting remains unclear. OBJECTIVE: To determine if favorable results could be reproduced in a community hospital setting using our ERAS program, which was developed using core ERAS guidelines with the goal of accelerated recovery while also addressing other important outcomes affecting patient experience and safety. DESIGN, SETTING, AND PARTICIPANTS: Prospective study of ERAS program, a multidisciplinary effort involving anesthesia, preadmission staff, nursing, and surgery staff at a community hospital. The program was initiated in 2010 and was in full practice by 2011. We assessed practice patterns and patient outcomes for all elective colon and rectal resection cases performed in 2009 (prior to ERAS implementation), 2011, and 2012. MAIN OUTCOMES AND MEASURES: Laparoscopic approach, narcotic use, length of stay, 30-day readmission, ileus (defined as reinsertion of nasogastric tube), and intra-abdominal infection and association between colorectal cancer (CRC) diagnosis and these outcomes. RESULTS: From 2009 to 2012, the use of laparoscopy increased from 57.4% to 88.8% (P < .001). Length of stay decreased significantly (6.7 days vs 3.7 days, P < .001), without an increase in 30-day readmission rate (17.6% vs 12.5%, P = .49). Use of patient-controlled narcotic analgesia and duration of use decreased (63.2% of patients vs 15%, P < .001; 67.8 hours vs 47.1 hours, P = .02). Ileus rate decreased from 13.2% to 2.5% (P = .02). Intra-abdominal infection decreased from 7.4% to 2.5% (P = .24). When comparing laparoscopic cases alone, similar results were observed. Following regression analysis, there were no statistically significant differences between CRC diagnosis and LOS, 30-day readmission rates, ileus, and intra-abdominal infection (all P's > .05). Length of stay reductions resulted in an estimated cost savings of $3202 per patient (2011) and $4803 per patient (2012). CONCLUSIONS AND RELEVANCE: Implementation of this patient care-directed enhanced recovery program is feasible in a community hospital setting, and it is associated with decreased LOS without increased readmission or morbidity, as well as significant decreases in narcotic use and cost. Improved outcomes are independent of the laparoscopic approach and CRC diagnosis.

PPI therapy and albumin are better predictors of recurrent Clostridium difficile colitis than choice of antibiotics.

BACKGROUND: Recurrent Clostridium difficile colitis (RCDC) is common, but data regarding recurrence rates and predisposing factors are sparse. METHODS: A retrospective case-control study was performed, identifying all inpatients and outpatients ≥18 years of age with C. difficile colitis (CDC) confirmed by a positive stool sample collected at our institution from January 2008 to August 2011. Factors associated with RCDC, the number of RCDC episodes, and the need for admission for RCDC were sought. RESULTS: A total of 739 patients (male, 47 %) were studied, of whom 527 (71 %) received inpatient treatment for their index episode of CDC. There was no difference (p = 0.53) between RCDC rates for inpatients (17.6 %) and outpatients (19.8 %). While severity score and albumin were associated with RCDC in our population, use of proton pump inhibitors (PPIs) correlated with decreased RCDC (p = 0.006) and decreased need for admission (p = 0.005). The addition of vancomycin to metronidazole therapy did not lower RCDC rates (p = 0.52) or decrease the need for admission (p = 0.78). CONCLUSIONS: Hypoalbuminemia strongly correlated with higher recurrence rates, while PPI therapy actually reduced RCDC, representing previously underappreciated potential therapeutic targets for lowering CDC recurrence. The addition of vancomycin to metronidazole did not improve RCDC rates.

Proinflammatory cytokines induce NF-kappaB-dependent/NO-independent chemokine gene expression in MIN6 beta cells.

BACKGROUND: Interactions between chemokines IP-10, MCP-1, and RANTES and their receptors may mediate graft rejection following islet transplantation. The mechanisms regulating chemokine gene expression in pancreatic islet cells have not been well characterized. We examined the cytokine-induced gene expression profiles for several chemokines in a transformed pancreatic beta-cell line (MIN6) cotreated with an inhibitor of nitric oxide synthase and in a mutated clone of MIN6 made to overexpress a dominant negative inhibitor of NF-kappaB (IkappaBalphaM). METHODS: MIN6 and MIN6-IkappaBalphaM (Bm) cells were cultured in mixtures of IL-1beta and TNF-alpha or IL-1beta, TNF-alpha, and IFN-gamma plus/minus the iNOS inhibitor L-NMMA. RT-PCR and RNase Protection Assay were used to measure mRNA expression for the following chemokines: IP-10, MIP-1alpha, MIP-1beta, MCP-1, and RANTES. Enzyme linked immunosorbant assay was used to measure IP-10 and MCP-1 protein release. RESULTS: Cytokine-treated MIN6 and Bm demonstrated increased expression of genes for IP-10 and MCP-1. Expression in MIN6 was first detected at 2 h of incubation and peaked at 6 h. MIN6 demonstrated a more marked increase in chemokine gene expression for both IP-10 and MCP-1 and a more marked increase in IP-10 protein release than did Bm. There was no detectable gene expression for MIP-1alpha, MIP-1beta, or RANTES from MIN6 or Bm. L-NMMA completely blocked NO production from MIN6 and Bm but had no effect on chemokine gene expression in either MIN6 or Bm. CONCLUSIONS: These results suggest that beta cells produce a complement of rejection-relevant chemokines in response to a proinflammatory stimulus and that pathways governing cytokine-induced chemokine gene expression in MIN6 are dependent on NF-kappaB but independent of NO.