Linea Arcuate Hernia Following Transversus Abdominis Release Incisional Hernia Repair.

Open abdominal surgery continues to be most commonly complicated by postoperative herniation at the incision line. In 2012, Novitsky et al described a novel hernia repair technique that utilized a transversus abdominis release coupled with a posterior (retrorectus) component separation (TAR-PCS) of the ventral abdominal wall. Early reports attest to the versatility and low recurrence rate of this technique, particularly when repairing large and complex defects. We present a rare case of herniation below the linea arcuate (LAH) following repair via TAR-PCS. Given its novelty compared with more widely utilized techniques, literature review revealed less discussion regarding potential pitfalls associated with this type of reconstruction, in particular the potential for LAH. To date, only 9 cases of symptomatic LAH have been described, although 2 previously described "suprapubic" herniations following TAR-PCS may represent previously mischaracterized cases of this type of complication. Nonetheless, none of these reports were in the setting of ventral hernia repair.

Delayed radiation-induced inflammation accompanying a marked carbohydrate antigen 19-9 elevation in a patient with resected pancreatic cancer.

Although carbohydrate antigen (CA) 19-9 is a useful tumor marker for pancreatic cancer, it can also become elevated from a variety of benign and malignant conditions. Herein we describe an unusual presentation of elevated CA 19-9 in an asymptomatic patient who had previously undergone adjuvant chemotherapy and radiation therapy for resected early stage pancreatic cancer. The rise in CA 19-9 might be due to delayed radiation-induced inflammation related to previous intra-abdominal radiation therapy with or without radiation recall induced by gemcitabine. After treatment with corticosteroids the CA 19-9 level decreased to normal, and the patient has not developed any evidence of recurrent cancer to date.

Pancreatectomy in Patients with Impaired Renal Function: How Risky Is It?

Chronic renal impairment causes profound physiologic and metabolic changes. Its impact on surgical outcome after pancreatectomy is not well established. We sought to quantify complication rates of pancreatectomy in patients with chronic renal impairment. Database from the American College of Surgeons National Surgical Quality Improvement Project (2005-2011) was queried to identify patients with chronic renal impairment who underwent pancreatectomy. The study population consisted of 16,708 patients of whom 16,649 patients were not on dialysis and 59 patients were on dialysis. Overall mortality for those on dialysis was 5.1 per cent, whereas it was 2.3 per cent for those not on dialysis (P = 0.114). Patients on dialysis were more likely to have failure to wean ventilation (P < 0.001), reintubation (P = 0.004), myocardial infarction (P = 0.007), and sepsis (P = 0.046). Patients not on dialysis were then divided into three groups: serum creatinine levels <1.2 mg/dL, between 1.2 mg/dL and 2.0 mg/dL, and >2.0 mg/dL. We found the mortality rates for these three groups were 2.0 per cent, 4.6 per cent, and 7.5 per cent, respectively (P < 0.001). In conclusion, need for dialysis is associated with increased postoperative complications. Increased serum creatinine levels were associated with increased mortality rates. These findings should facilitate informative risk/benefit calculation for patients with renal impairment who are considering pancreatectomy.

Littoral cell angioma: A case report.

Primary splenic lesions are rare entities among which littoral cell angioma (LCA) is a recently described, uncommon vascular lesion that is unique to the spleen. It has heretofore been described primarily in pathologic series and has been found mostly to behave as a benign entity. A few reports of malignant variants have been reported. We present a case report of a solitary LCA discovered after splenectomy for an incidentally discovered splenic lesion, along with a literature review.

Perirenal extra-adrenal myelolipoma.

Myelolipomas are rare tumors consisting of both adipose and hematopoietic tissue and are typically found within the adrenal gland. Extra-adrenal involvement is rare, especially those tumors involving the perirenal space and collecting system. We report a case of a patient with an incidentally discovered perirenal mass that was initially concerning for a retroperitoneal liposarcoma. Following surgical resection and pathological analysis, the lesion was found to be an extra-adrenal myelolipoma. This case report and review of the literature demonstrates the importance of the proper work-up and management of perirenal lipoma variants while addressing the issues of tissue biopsy, surgical intervention, and pre- and post-operative surveillance.

Interferon regulatory factor-1 mediates the release of high mobility group box-1 in endotoxemia in mice.

BACKGROUND: The extracellular release of the danger signal high mobility group box-1 (HMGB1) has been implicated in the pathogenesis and outcomes of sepsis. Understanding the mechanisms responsible for HMGB1 release can lead to the identification of targets that may inhibit this process. The transcription factor interferon regulatory factor-1 (IRF-1) is an important mediator of innate immune responses and has been shown to participate in mortality associated with endotoxemia; however, its role in mediating the release of HMGB1 in these settings is unknown. METHODS: Male IRF-1 knockout (KO) and age matched C57BL/6 wild type (WT) mice were given intraperitoneal (IP) injections of lipopolysaccharide (LPS). In some experiments, 96 hours survival rates were observed. In other experiments, mice were sacrificed 12 hours after LPS administration and sera were harvested for future analysis. In in vitro study, RAW 264.7 murine monocyte/macrophage-like cells or primary peritoneal macrophage obtained from IRF-1 KO and WT mice were cultured for LPS mediated HMGB1 release analysis. And the mechanism for HMGB1 release was analyzed by immune-precipitation. RESULTS: IRF-1 KO mice experienced less mortality, and released less systemic HMGB1 compared to their WT counterparts. Exogenous administration of recombinant HMGB1 to IRF-1 KO mice returned the mortality rate to that seen originally in IRF-1 WT mice. Using cultures of peritoneal macrophages or RAW264.7 cells, in vitro LPS stimulation induced the release of HMGB1 in an IRF-1 dependent manner. And the janus associated kinase (JAK)-IRF-1 signal pathway appeared to participate in the signaling mechanisms of LPS-induced HMGB1 release by mediating acetylation of HMGB1. CONCLUSION: IRF-1 plays a role in LPS induced release of HMGB1 and therefore may serve as a novel target in sepsis.

Radiofrequency ablation compared to resection in early-stage hepatocellular carcinoma.

OBJECTIVES: This study aimed to compare survival outcomes after hepatic resection (HR) and radiofrequency ablation (RFA) in early-stage hepatocellular carcinoma (HCC) at a Western hepatobiliary centre. METHODS: Demographic details, clinicopathologic tumour characteristics and survival outcomes were compared among non-transplant candidate patients undergoing HR (n= 50) and RFA (n= 60) for early-stage HCC during 2001-2011. RESULTS: Patients who underwent HR had larger tumours, a longer length of stay and a higher rate of postoperative complications. After a median follow-up of 29 months, there were no significant differences between the treatment groups in 1-, 3- and 5-year overall survival (OS) [RFA group: 86%, 50%, 35%, respectively; HR group: 88%, 68%, 47%, respectively (P= 0.222)] or disease-free survival (DFS) [RFA group: 68%, 42%, 28%, respectively; HR group: 66%, 42%, 34%, respectively (P= 0.823)]. The 58 patients who underwent RFA demonstrated ablation success on follow-up computed tomography at 3 months. Of these, 96.5% of patients showed sustained ablation success over the entire follow-up period. In a subgroup analysis of patients with tumours measuring 2-5 cm, no differences in OS or DFS emerged between the HR and RFA groups. Similarly, no significant differences in outcomes in patients with Child-Pugh class A cirrhosis were seen between the RFA and HR groups. CONCLUSIONS: Radiofrequency ablation is comparable with HR in terms of OS and DFS. It is a reasonable alternative as a first-line treatment for HCC in well-selected patients who are not candidates for transplant.

Indeterminate pulmonary nodules represent lung metastases in a significant portion of patients undergoing liver resection for malignancy.

INTRODUCTION: Despite detection on imaging before resection of hepatic malignancies, the natural history of indeterminate pulmonary nodules (IPN) is unknown. The objective of this study is to determine how often IPN detected on imaging before surgery for hepatic malignancies represent lung metastases. METHODS: Demographics, comorbidities, tumor characteristics, and surgical treatments of patients with pre-operative IPN who underwent liver resection and/or radiofrequency ablation for malignant diagnoses were reviewed. RESULTS: From 2000 to 2010, 90 patients with at least one IPN underwent liver resection or radiofrequency ablation for malignancy. Of these, 44 (48.9 %), 32 (35.6 %), and 14 (15.6 %) patients had colorectal cancer liver metastases (CRCLM), primary hepatobiliary malignancies (HB), and other cancers, respectively. The median number of IPN was 1. The median size was 4 mm. Twenty (22 %) patients had isolated lung recurrence after hepatic surgical therapy. Eighty percent occurred in the exact location of the pre-operative IPN. Isolated lung recurrence was more common among patients with CRCLM compared to those with HB and other cancers (42.9 vs. 9.4 vs. 14.3 %, p = 0.004). CONCLUSION: Pre-operatively detected IPN represent lung metastases in a substantial portion of patients undergoing surgery for hepatic malignancy. IPN are more likely to represent lung metastases in patients with CRCLM compared to those with primary HB and other cancers.

Interferon regulatory factor-2 is protective against hepatic ischemia-reperfusion injury.

Interferon regulatory factor (IRF)-1 is a nuclear transcription factor that induces inflammatory cytokine mediators and contributes to hepatic ischemia-reperfusion (I/R) injury. No strategies to mitigate IRF1-mediated liver damage exist. IRF2 is a structurally similar endogenous protein that competes with IRF1 for DNA binding sites in IRF-responsive target genes and acts as a competitive inhibitor. However, the role of IRF2 in hepatic injury during hypoxic or inflammatory conditions is unknown. We hypothesize that IRF2 overexpression may mitigate IRF1-mediated I/R damage. Endogenous IRF2 is basally expressed in normal livers and is mildly increased by ischemia alone. Overexpression of IRF2 protects against hepatic warm I/R injury. Furthermore, we demonstrate that IRF2 overexpression limits production of IRF1-dependent proinflammatory genes, such as IL-12, IFNß, and inducible nitric oxide synthase, even in the presence of IRF1 induction. Additionally, isograft liver transplantation with IRF2 heterozygote knockout (IRF2(+/-)) donor grafts that have reduced endogenous IRF2 levels results in worse injury following cold I/R during murine orthotopic liver transplantation. These findings indicate that endogenous intrahepatic IRF2 protein is protective, because the IRF2-deficient liver donor grafts exhibited increased liver damage compared with the wild-type donor grafts. In summary, IRF2 overexpression protects against I/R injury by decreasing IRF1-dependent injury and may represent a novel therapeutic strategy.

Calcium/calmodulin-dependent protein kinase IV limits organ damage in hepatic ischemia-reperfusion injury through induction of autophagy.

Sterile inflammatory insults, such as ischemia-reperfusion (I/R) injury, result from pathogenic factors, including damage-associated molecular pattern signaling, activation of innate immunity, and upregulation of proinflammatory cytokines. At the same time, a number of protective, or prosurvival, pathways are also activated, and the extent of end-organ damage is ultimately determined by the balance between these two systems. In liver I/R, members of the calcium/calmodulin-dependent protein kinase (CaMK) family are known to be activated, but their individual roles are largely unknown. In this study, we show that one CaMK member, CaMKIV, is protective in hepatic I/R by activating the prosurvival pathway of autophagy in hepatocytes. CaMKIV knockout mice experience significantly worse organ damage after I/R and are deficient in hepatocyte autophagic signaling. Restoration of autophagic signaling with rapamycin reduces organ damage in CaMKIV knockout mice to wild-type levels. In vitro, we show that CaMKIV activation induces autophagy in mouse hepatocytes, and that CaMKIV activation protects hepatocytes from oxidative stress-induced cell death. In conclusion, the protective autophagic signaling pathway serves to reduce organ damage following I/R and is regulated by activation of CaMKIV signaling in hepatocytes.

Splenocyte apoptosis and autophagy is mediated by interferon regulatory factor 1 during murine endotoxemia.

Sepsis-induced lymphocyte and dendritic cell apoptosis contributes to immunosuppression, which results in an inability to eradicate the primary infection as well as a propensity to acquire new, secondary infections. Another cellular process, autophagy, is also activated in immune cells and plays a protective role. In the present study, we demonstrate that interferon regulatory factor 1 (IRF-1) regulates both immune cell apoptosis and autophagy in a murine endotoxemia model. Interferon regulatory factor 1 is activated at an early phase through a Toll-like receptor 4-dependent, myeloid differentiation primary response gene 88-independent manner in splenocytes. Furthermore, IRF-1 knockout (KO) mice are protected from a lethal endotoxemia model. This protection is associated with decreased apoptosis and increased autophagy in splenocytes. Interferon regulatory factor 1 KO mice experience decreased apoptotic cell loss, especially in CD4⁺ T lymphocytes and myeloid antigen-presenting cells. Meanwhile, IRF-1 KO mice demonstrate increased autophagy and improved mitochondrial integrity. This increased autophagy in KO mice is attributable, at least in part, to deactivation of mammalian target of rapamycin/P70S6 signaling--a main negative regulator of autophagy. Therefore, we propose a novel role for IRF-1 in regulating both apoptosis and autophagy in splenocytes in the setting of endotoxemia with IRF-1 promoting apoptosis and inhibiting autophagy.

High-mobility group box 1 activates caspase-1 and promotes hepatocellular carcinoma invasiveness and metastases.

UNLABELLED: Hypoxia is often found in solid tumors and is associated with tumor progression and poor clinical outcomes. The exact mechanisms related to hypoxia-induced invasion and metastasis remain unclear. We elucidated the mechanism by which the nuclear-damage-associated molecular pattern molecule, high-mobility group box 1 (HMGB1), released under hypoxic stress, can induce an inflammatory response to promote invasion and metastasis in hepatocellular carcinoma (HCC) cells. Caspase-1 activation was found to occur in hypoxic HCC cells in a process that was dependent on the extracellular release of HMGB1 and subsequent activation of both Toll-like receptor 4 (TLR4)- and receptor for advanced glycation endproducts (RAGE)-signaling pathways. Downstream from hypoxia-induced caspase-1 activation, cleavage and release of proinflammatory cytokines interleukin (IL)-1ß and -18 occurred. We further demonstrate that overexpression of HMGB1 or treatment with recombinant HMGB1 enhanced the invasiveness of HCC cells, whereas stable knockdown of HMGB1 remarkably reduced HCC invasion. Moreover, in a murine model of HCC pulmonary metastasis, stable knockdown of HMGB1 suppressed HCC invasion and metastasis. CONCLUSION: These results suggest that in hypoxic HCC cells, HMGB1 activates TLR4- and RAGE-signaling pathways to induce caspase-1 activation with the subsequent production of multiple inflammatory mediators, which, in turn, promote cancer invasion and metastasis.

Interferon regulatory factor-1 regulates the autophagic response in LPS-stimulated macrophages through nitric oxide.

The pathogenesis of sepsis is complex and, unfortunately, poorly understood. The cellular process of autophagy is believed to play a protective role in sepsis; however, the mechanisms responsible for its regulation in this setting are ill defined. In the present study, interferon regulatory factor 1 (IRF-1) was found to regulate the autophagic response in lipopolysaccharide (LPS)-stimulated macrophages. In vivo, tissue macrophages obtained from LPS-stimulated IRF-1 knockout (KO) mice demonstrated increased autophagy and decreased apoptosis compared to those isolated from IRF-1 wild-type (WT) mice. In vitro, LPS-stimulated peritoneal macrophages obtained from IRF-1 KO mice experienced increased autophagy and decreased apoptosis. IRF-1 mediates the inhibition of autophagy by modulating the activation of the mammalian target of rapamycin (mTOR). LPS induced the activation of mTOR in WT peritoneal macrophages, but not in IRF-1 KO macrophages. In contrast, overexpression of IRF-1 alone increased the activation of mTOR and consequently decreased autophagic flux. Furthermore, the inhibitory effects of IRF-1 mTOR activity were mediated by nitric oxide (NO). Therefore, we propose a novel role for IRF-1 and NO in the regulation of macrophage autophagy during LPS stimulation in which IRF-1/NO inhibits autophagy through mTOR activation.

Outcomes of curative treatment for hepatocellular cancer in nonalcoholic steatohepatitis versus hepatitis C and alcoholic liver disease.

UNLABELLED: Concomitant increasing incidences of hepatocellular carcinoma (HCC) and nonalcoholic steatohepatitis (NASH) suggest that a substantial proportion of HCC arises as a result of hepatocellular injury from NASH. The aim of this study was to determine differences in severity of liver dysfunction at HCC diagnosis and long-term survival outcomes between patients undergoing curative therapy for HCC in the background of NASH compared to hepatitis C virus (HCV) and/or alcoholic liver disease (ALD). Patient demographics and comorbidities, clinicopathologic data, and long-term outcomes among patients who underwent liver transplantation, hepatic resection, or radiofrequency ablation for HCC were reviewed. From 2000 to 2010, 303 patients underwent curative treatment of HCC; 52 (17.2%) and 162 (53.5%) patients had NASH and HCV and/or alcoholic liver disease. At HCC diagnosis, NASH patients were older (median age 65 versus 58 years), were more often female (48.1% versus 16.7%), more often had the metabolic syndrome (45.1% versus 14.8%), and had lower model for end-stage liver disease scores (median 9 versus 10) (all P < 0.05). NASH patients were less likely to have hepatic bridging fibrosis or cirrhosis (73.1% versus 93.8%; P < 0.001). After a median follow-up of 50 months after curative treatment, the most frequent cause of death was liver failure. Though there were no differences in recurrence-free survival after curative therapy (median, 60 versus 56 months; P = 0.303), NASH patients had longer overall survival (OS) (median not reached versus 52 months; P = 0.009) independent of other clinicopathologic factors and type of curative treatment. CONCLUSION: Patients with HCC in the setting of NASH have less severe liver dysfunction at HCC diagnosis and better OS after curative treatment compared to counterparts with HCV and/or alcoholic liver disease.

Interferon regulatory factor 1 mediates acetylation and release of high mobility group box 1 from hepatocytes during murine liver ischemia-reperfusion injury.

Damage-associated molecular patterns (DAMPs) initiate inflammatory pathways that are common to both sterile and infectious processes. The DAMP, high-mobility group box 1 (HMGB1), and the transcription factor, interferon regulatory factor 1 (IRF-1), have been independently associated as key players in ischemia-reperfusion (I/R) injury. Our study demonstrates that IRF-1 contributes to hepatocellular release of HMGB1 and further that IRF-1 is a necessary component of HMGB1 release in response to hypoxia or after liver I/R. We also link the nuclear upregulation of IRF-1 to the presence of functional Toll-like receptor 4 (TLR4), a pattern recognition receptor also important in sterile and infectious processes. Using IRF-1 chimeric mice, we show that IRF-1 upregulation in hepatic parenchymal cells, and not in the bone marrow-derived immune cells, is responsible for HMGB1 release during ischemic liver injury. Finally, our study also demonstrates a role for IRF-1 in modulating the acetylation status and subsequent release of HMGB1 through histone acetyltransferases. We found that serum HMGB1 is acetylated after liver I/R and that this process was dependent on IRF-1. Additionally, liver I/R induced a direct association of IRF-1 and the nuclear histone acetyltransferase enzyme p300. Together, these findings suggest that I/R-induced release of acetylated HMGB1 is a process that is dependent on TLR4-mediated upregulation of IRF-1.

High mobility group box 1 release from hepatocytes during ischemia and reperfusion injury is mediated by decreased histone deacetylase activity.

The mobilization and extracellular release of nuclear high mobility group box-1 (HMGB1) by ischemic cells activates inflammatory pathways following liver ischemia/reperfusion (I/R) injury. In immune cells such as macrophages, post-translational modification by acetylation appears to be critical for active HMGB1 release. Hyperacetylation shifts its equilibrium from a predominant nuclear location toward cytosolic accumulation and subsequent release. However, mechanisms governing its release by parenchymal cells such as hepatocytes are unknown. In this study, we found that serum HMGB1 released following liver I/R in vivo is acetylated, and that hepatocytes exposed to oxidative stress in vitro also released acetylated HMGB1. Histone deacetylases (HDACs) are a family of enzymes that remove acetyl groups and control the acetylation status of histones and various intracellular proteins. Levels of acetylated HMGB1 increased with a concomitant decrease in total nuclear HDAC activity, suggesting that suppression in HDAC activity contributes to the increase in acetylated HMGB1 release after oxidative stress in hepatocytes. We identified the isoforms HDAC1 and HDAC4 as critical in regulating acetylated HMGB1 release. Activation of HDAC1 was decreased in the nucleus of hepatocytes undergoing oxidative stress. In addition, HDAC1 knockdown with siRNA promoted HMGB1 translocation and release. Furthermore, we demonstrate that HDAC4 is shuttled from the nucleus to cytoplasm in response to oxidative stress, resulting in decreased HDAC activity in the nucleus. Together, these findings suggest that decreased nuclear HDAC1 and HDAC4 activities in hepatocytes following liver I/R is a mechanism that promotes the hyperacetylation and subsequent release of HMGB1.

mTOR and GSK-3 shape the CD4+ T-cell stimulatory and differentiation capacity of myeloid DCs after exposure to LPS.

Prolonged inhibition of the kinase, mammalian target of rapamycin (mTOR), during myeloid dendritic cell (DC) generation confers resistance to maturation. Recently, however, mTOR inhibition immediately before Toll-like receptor ligation has been found to exert proinflammatory effects on myeloid cells, notably enhanced IL-12p40/p70 production. We show, for the first time, that mouse or human DCs generated under mTOR inhibition exhibit markedly enhanced IL-12p70 production after lipopolysaccharide (LPS) stimulation, despite impaired costimulatory molecule expression and poor T-cell stimulatory ability. Consistent with this finding, we reveal that increased IL-12p40 production occurs predominantly in CD86(lo) immature DCs. High IL-12p40/p70 production by CD86(lo) DC resulted from failed down-regulation of glycogen synthase kinase-3 (GSK-3) activity and could not be ascribed to enhanced Akt function. Despite high IL-12p70 secretion, rapamycin-conditioned, LPS-stimulated DCs remained poor T-cell stimulators, failing to enhance allogeneic Th1 cell responses. We also report that inhibition of GSK-3 impedes the ability of LPS-stimulated DCs to induce forkhead box p3 in CD4(+)CD25(-) T cells, as does the absence of IL-12p40/p70. Thus, GSK-3 activity in DC is regulated via signaling linked to mTOR and modulates their capacity both to produce IL-12p40/p70 and induce forkhead box p3 in CD4(+) T cells under inflammatory conditions.