Lisa M. Colletti

Role of tumor necrosis factor-alpha in the pathophysiologic alterations after hepatic ischemia/reperfusion injury in the rat.

Cytokines are recognized as critical early mediators of organ injury. We attempted to determine whether or not severe hepatic ischemia/reperfusion injury results in tumor necrosis factor-alpha (TNF-alpha) release with subsequent local and systemic tissue injury. After 90 min of lobar hepatic ischemia, TNF was measurable during the reperfusion period in the plasma of all 14 experimental animals, with levels peaking between 9 and 352 pg/ml. Endotoxin was undetectable in the plasma of these animals. Pulmonary injury, as evidenced by a neutrophilic infiltrate, edema and intra-alveolar hemorrhage developed after hepatic reperfusion. The neutrophilic infiltrate was quantitated using a myeloperoxidase (MPO) assay; this demonstrated a significant increase in MPO after only 1 h of reperfusion. Anti-TNF antiserum pretreatment significantly reduced the pulmonary MPO after hepatic reperfusion. After a 12-h reperfusion period, there was histologic evidence of intra-alveolar hemorrhage and pulmonary edema. Morphometric assessment showed that pretreatment with anti-TNF antiserum was able to completely inhibit the development of pulmonary edema. Liver injury was quantitated by measuring serum glutamic pyruvic transaminase which showed peaks at 3 and 24 h. Anti-TNF antiserum pretreatment was able to significantly reduce both of these peak elevations. These data show that hepatic ischemia/reperfusion results in TNF production, and that this TNF is intimately associated with pulmonary and hepatic injury.

Chemokine expression during hepatic ischemia/reperfusion-induced lung injury in the rat. The role of epithelial neutrophil activating protein.

The liver is highly susceptible to a number of pathological insults, including ischemia/reperfusion injury. One of the striking consequences of liver injury is the associated pulmonary dysfunction that may be related to the release of hepatic-derived cytokines. We have previously employed an animal model of hepatic ischemia/reperfusion injury, and demonstrated that this injury causes the production and release of hepatic-derived TNF, which mediates a neutrophil-dependent pulmonary microvascular injury. In this study, we have extended these previous observations to assess whether an interrelationship between TNF and the neutrophil chemoattractant/activating factor, epithelial neutrophil activating protein-78 (ENA-78), exists that may be accountable for the pathology of lung injury found in this model. In the context of hepatic ischemia/reperfusion injury, we demonstrated the following alterations in lung pathophysiology: (a) an increase in pulmonary microvascular permeability, lung neutrophil sequestration, and production of pulmonary-derived ENA-78; (b) passive immunization with neutralizing TNF antiserum resulted in a significant suppression of pulmonary-derived ENA-78; and (c) passive immunization with neutralizing ENA-78 antiserum resulted in a significant attenuation of pulmonary neutrophil sequestration and microvascular permeability similar to our previous studies with anti-TNF. These findings support the notion that pulmonary ENA-78 produced in response to hepatic-derived TNF is an important mediator of lung injury.

A multi-institutional phase II trial of preoperative full-dose gemcitabine and concurrent radiation for patients with potentially resectable pancreatic carcinoma

BackgroundWe report the results of a multi-institutional phase II trial that used preoperative full-dose gemcitabine and radiotherapy for patients with potentially resectable pancreatic carcinoma.MethodsPatients were treated before surgery with three cycles of full-dose gemcitabine (1000 mg/m2 intravenously), with radiation during the second cycle (36 Gy in daily 2.4-Gy fractions). Patients underwent surgery 4 to 6 weeks after the last gemcitabine infusion.ResultsThere were 10 men and 10 women, with a median age of 58 years (range, 50–80 years). Nineteen patients (95%) completed therapy without interruption, and one experienced grade 3 gastrointestinal toxicity. The mean weight loss after therapy was 4.0%. Of 20 patients taken to surgery, 17 (85%) underwent resections (16 pancreaticoduodenectomies and 1 distal pancreatectomy). The complication rate was 24%, with an average length of stay of 13.5 days. There were no operative deaths. Pathologic analysis revealed clear margins in 16 (94%) of 17 and uninvolved lymph nodes in 11 (65%) of 17 specimens. One specimen contained no residual tumor, and three specimens revealed only microscopic foci of residual disease. With a median follow-up of 18 months, 7 (41%) of the 17 patients with resected disease are alive with no recurrence, 3 (18%) are alive with distant metastases, and 7 (41%) have died.ConclusionsPreoperative gemcitabine/radiotherapy is well tolerated and safe when delivered in a multi-institutional setting. This protocol had a high rate of subsequent resection, with acceptable morbidity. The high rate of negative margins and uninvolved nodes suggests a significant tumor response. Preliminary survival data are encouraging. This regimen should be considered in future neoadjuvant trials for pancreatic cancer.

The production of tumor necrosis factor alpha and the development of a pulmonary capillary injury following hepatic ischemia/reperfusion.

The large mass of fixed macrophages resident in the liver make it a potentially rich source of cytokines. We have previously demonstrated that an isolated and severe ischemia/reperfusion injury to the liver results in cytokine release, specifically tumor necrosis factor alpha, and that TNF is then involved in the development of pulmonary pathology. This study was designed to determine the kinetics of TNF release following varying periods of hepatic ischemia and to further investigate the acute lung injury that follows. Suprahepatic blood samples were obtained at serial time points following a 45-, 60-, 75-, or 90-min ischemic insult to a segment of the rat liver with subsequent reperfusion. Using a bioassay based on the WEHI 164 cell line, plasma TNF levels were measured in all experimental animals; sham-operated control animals had undetectable levels. Changes in pulmonary capillary permeability were then measured using a standard 125I-labeled albumin washout technique following a 90-min ischemic insult with subsequent reperfusion. A significant increase in the mean permeability index was observed 9 to 12 hr following hepatic reperfusion (.601 +/- 102 as compared with .114 +/- .085 in sham-operated controls, P less than 0.005). Animals treated with anti-TNF antiserum prior to the induction of hepatic ischemia had a significantly reduced pulmonary capillary leak compared to animals pretreated with rabbit serum without TNF-blocking properties (.184 +/- .029 versus .694 +/- 052 for the control serum, P less than 0.005). TNF release follows both moderate and severe ischemic injury to the liver and the results reported here implicate TNF as an important mediator of increased pulmonary capillary permeability. These experiments confirm previous histologic studies that demonstrated pulmonary edema and intra-alveolar hemorrhage following hepatic ischemia/reperfusion, with subsequent blockade of the histologic injury by pretreatment with anti-TNF antiserum.

Cytokines and the liver

I N RECENT YEARS there has been an explosion of interest in the group of inflammatory mediators collectively known as cytokines. Research activity in this area is likely to expand at an even greater rate with the reported inhibition of human immunodeficiency virus (HIV) entry into cells by certain chemotactic cytokines. Even now, hardly a month passes without additions to the interleukin family (presently at number 18 or 19) or the characterisation of another monocyte chemotactic and activating factor (MCAF), monocyte chemoattractant protein (MCP), leukaemia inhibitory factor (LIF) or macrophage migration inhibitory factor (MIF). In addition, there is increasing recognition of the multiple functions of more widely known cytokines, such as tumour necrosis factor (Y (TNFa), and their effects on the liver. It would therefore seem timely to review recent data regarding the physiological and pathological role of cytokines in the liver and, even more interestingly, their potential therapeutic applications.

Tumor necrosis factor up-regulates intercellular adhesion molecule 1, which is important in the neutrophil-dependent lung and liver injury associated with hepatic ischemia and reperfusion in the rat

Tumor necrosis factor (TNF) is released during hepatic ischemia/reperfusion (I/R) and plays an important role in the ensuing neutrophil-mediated lung and liver injury. Since TNF is not a direct neutrophil chemotaxin, we hypothesized that TNF may up-regulate neutrophil adhesion molecules, specifically intercellular adhesion molecule-1 (ICAM-1), following hepatic I/R, and that this molecule then plays an important role in tissue neutrophil influx. Rats underwent 90 min of lobar hepatic ischemia with reperfusion. Pulmonary and hepatic ICAM-1 expression were assessed by reverse transcription-polymerase chain reaction, Western blot analysis, and immunohistochemical staining. Increases in hepatic ICAM-1 were demonstrated within 1 h of reperfusion, while increases in pulmonary ICAM-1 were not seen until 6 h of reperfusion. Next, rats were treated with anti-TNF antibody or control antibody without TNF neutralizing properties prior to hepatic I/R. Pretreatment with anti-TNF antibody significantly decreased pulmonary and hepatic ICAM-1 expression after hepatic I/R. We next investigated the effects of pretreatment with anti-ICAM-1 antibodies on the lung and liver injury that follows hepatic I/R. Lung injury was assessed by changes in pulmonary capillary permeability as estimated by extravasation of Evans Blue dye and pulmonary neutrophil influx as measured by lung myeloperoxidase levels. Liver injury was assessed by hepatic neutrophil morphometrics and plasma liver enzymes (alanine aminotransferase). Pretreatment with anti-ICAM-1 antibodies significantly decreased pulmonary capillary permeability, pulmonary myeloperoxidase, hepatic neutrophil influx, and plasma alanine aminotransferase, as compared to animals pretreated with control antibody. These data suggest that TNF is a proximal trigger for pulmonary and hepatic ICAM-1 up-regulation following hepatic ischemia with reperfusion, and that ICAM-1 is important for pulmonary and hepatic neutrophil influx, with the resultant tissue injury, following hepatic I/R.

Novel CXCR2-dependent liver regenerative qualities of ELR-containing CXC chemokines

Severe acute liver injury due to accidental or intentional acetaminophen overdose presents a major clinical dilemma often requiring liver transplantation. In the present study, liver regeneration after profound liver injury in mice challenged with acetaminophen was facilitated by the exogenous addition of ELR‐containing CXC chemokines such as macrophage inflammatory protein‐2 (MIP‐2), epithelial neutrophil‐activating protein‐78 (ENA‐78), or interleukin 8. Intravenous administration of ELR‐CXC chemokines or N‐acetyl‐cysteine (NAC) immediately after acetaminophen challenge in mice significantly reduced histological and biochemical markers of hepatic injury. However, when the intervention was delayed until 10 h after acetaminophen challenge, only ELR‐CXC chemokines significantly reduced liver injury and mouse mortality. The delayed addition of ELR‐CXC chemokines to cultured hepatocytes maintained the proliferation of these cells in a CXCR2‐dependent fashion after acetaminophen challenge whereas delayed NAC treatment did not. These observations demonstrate that ELR‐CXC chemokines represent novel hepatic regenerative factors that exhibit prolonged therapeutic effects after acetaminophen‐induced hepatotoxicity.—Hogaboam, C. M., Bone‐Larson, C. L., Steinhauser, M. L., Lukacs, N. W., Colletti, L. M., Simpson, K. J., Strieter, R. M., Kunkel, S. L. Novel CXCR2‐dependent liver regenerative qualities of ELR‐containing CXC chemokines. FASEB J. 13, 1565–1574 (1999)

Surgical resection following radiation therapy with concurrent gemcitabine in patients with previously unresectable adenocarcinoma of the pancreas

The combination of gemcitabine with concurrent radiation therapy (Gem/RT) is a promising new approach that is being investigated in patients with unresectable pancreatic cancer. However, substantial toxicity with this combination has also been observed. This review was conducted to determine whether Gem/RT could be safely delivered in the neoadjuvant setting, based on our experience with this combined therapy in a cohort of patients with previously unresectable pancreatic cancer, who subsequently underwent surgical resection. Between July 1996 and June 2001, a total of 67 patients with locally unresectable pancreatic cancer, without distant metastatic disease, received Gem/RT at our institution. Seventeen patients (25%) underwent exploratory surgery following Gem/RT, and nine underwent standard Whipple resection. Thus 9 (52%) of 17 patients who had exploratory operations or 9 (13%) of 67 patients, underwent surgical resection. Thirty-day mortality after resection was 0%, and there were no major surgical complications. Median length of hospital stay was 14 days (range 11 to 19 days). With a median follow-up of 32 months, median survival for the resected patients was 17.6 months (95% confidence interval 12.6 to 37.3 months). Median survival for the remaining 58 patients was 11.9 months (95% confidence interval 9.6 to 14.7 months, P = 0.013). We conclude that surgical resection may be safely performed after Gem/RT in a select group of patients initially considered to have unresectable pancreatic cancer. The use of Gem/RT in a neoadjuvant setting is currently being investigated in a multi-institutional phase II trial.

Hospital volume and surgical outcomes for elderly patients with colorectal cancer in the United States.

BACKGROUND Recent emphasis has been placed on the quality of surgical care in the United States. As such, patients, providers, and payers are increasingly aware of the outcomes of surgical care as a marker of quality. The objective of this study was to determine the impact of hospital volume on mortality for patients of different age groups to determine whether elderly patients would derive more benefit from selective referral policies. METHODS Data from the Nationwide Inpatient Sample for all patients undergoing surgery for colorectal cancer during 1997 were obtained (N = 20,862). Differences in mortality associated with increasing age and hospital volume quartiles were determined. Risk-adjusted analyses of mortality were performed using multiple logistic regression. RESULTS The overall mortality rate was 3.1% for the 842 hospitals included. Patient age breakdown was the following: age <50, 7%; age 50 to 64, 19%; age 65 to 80, 51%; and age >80, 22%. Increasing age was associated with higher mortality rates: age <50, 0.8%; age 51 to 65, 1.3%; age 66 to 80, 2.9%; and >80, 6.9%. Overall, the highest volume hospitals (HVH) (>150/year) had lower mortality than the lowest volume hospitals (LVH) (<55/year) (2.5% vs. 3.7%; P = 0.006). However, the effect of volume on mortality was primarily due to differences in older patients. For patients greater than 65 years old, the mortality rate was 3.1% at HVH and 4.5% at LVH (P = 0.03). For patients greater than 80 years old, the mortality rate was 4.6% at HVH and 7.3% at LVH (P = 0.04). The results were unchanged after adjustment for patient demographics, comorbid disease, site of cancer, and type of resection. CONCLUSIONS The majority of deaths after surgery for colorectal cancer occur in older patients. Hospitals that perform higher volumes of colorectal resection have lower mortality rates, especially for older patients. In the absence of other information about the quality of surgical care, provider volumes are a useful marker of postoperative outcomes for older patients in need of surgery for colorectal cancer.

Proliferative effects of CXC chemokines in rat hepatocytes in vitro and in vivo.

ABSTRACT The CXC chemokines have well-documented neutrophil chemotactic, angiogenic, and mitogenic properties. The current investigations evaluate the effects of interleukin-8 (IL-8), epithelial neutrophil activating protein (ENA-78), and macrophage inflammatory peptide-2 (MIP-2) on hepatocyte proliferation in vitro and liver regeneration in vivo. Primary rat hepatocytes were isolated by collagenase digestion and exposed to incremental doses of IL-8, ENA-78, or MIP-2, and cellular proliferation was measured via tritiated thymidine incorporation. These experiments demonstrated significant increases in hepatocyte proliferation in response to IL-8, ENA-78, and MIP-2. Next, rats were sacrificed in a time-dependent manner following 70% hepatectomy or sham laparotomy, and hepatic tissue levels of MIP-2 and ENA-78 were measured using an ELISA. ENA-78 and MIP-2 were significantly elevated following 70% hepatectomy as compared with sham-operated control animals. Rats undergoing 70% hepatectomy were then treated with neutralizing anti-ENA-78 serum, anti-MIP-2 serum, or preimmune control serum, and liver regeneration was evaluated. These experiments demonstrated that neutralization of ENA-78 or MIP-2 slowed the rate of liver regeneration. These data suggest that the CXC chemokines may be important agents for the induction of hepatocyte proliferation and may be important molecules in vivo in the setting of liver injury, repair, and regeneration.