Luke O. Schoeniger

Induction of heat-shock gene expression in postischemic pig liver depends on superoxide generation

BACKGROUND/AIMS Both hemorrhagic and cardiogenic shock are associated with hepatic shock gene expression at resuscitation. This study investigated the potential role of intravascular superoxide anion as a proximal trigger of heat shock protein gene expression. METHODS Preanesthetized pigs were subjected to 120 m of total warm hepatic ischemia. The survival model consisted of warm, total hepatic ischemia and reperfusion (with active portal-systemic bypass) followed by reperfusion and survival for 3 days. Serial hepatic biopsy samples were evaluated for the expression of heat shock protein 72 (HSP-72) messenger RNA (mRNA) by Northern and Western analysis and by in situ RNA hybridization. The possible role of intravascular O2- as a mediator of heat shock response was evaluated by its specific inhibition by the intravenous infusion of recombinant human superoxide dismutase (SOD). RESULTS Ischemia for 120 minutes followed by 60 minutes of reperfusion caused accumulation of HSP-72 mRNA. Transcripts were localized to hepatocytes. HSP-72 mRNA was detected neither following ischemia alone nor when SOD was infused for 15 minutes at reperfusion. Three days later, transcripts were not detectable, but HSP-72 protein accumulated irrespective of SOD administration. CONCLUSIONS Warm hepatic ischemia induces the hepatocyte expression of HSP-72 at reperfusion by a mechanism that is dependent upon the superoxide anion, probably generated intravascularly. However, the transient dismutation of superoxide is insufficient to suppress subsequent accumulation of HSP-72.

A newly recognized entity : Intraductal 'oncocytic' papillary neoplasm of the pancreas

Intraductal papillary-mucinous tumors of the pancreas are increasingly recognized, and their characteristic endoscopic and radiological features are well reported in the literature in recent years. Oncocytic features in these tumors are uncommon and unrecognized. Intraductal oncocytic papillary neoplasm is a distinct pancreatic tumor and is a recently recognized entity. We report a case of a 69-yr-old patient who presented with symptoms mimicking pancreatitis, resulting in delay in the diagnosis of her pancreatic tumor. She underwent a successful Whipples procedure and subsequently has remained well. The resected specimen showed an intraductal oncocytic papillary-mucinous neoplasm. The entity is new and the literature information is inadequate at present to judge the biological behavior of this tumor. We discuss this recently recognized entity.

Laparoscopic spleen-preserving distal pancreatectomy

Distal pancreatectomy with spleen preservation may be the preferred procedure for certain benign tumors and cystic lesions of the pancreatic body or tail. Alternatively, laparoscopic removal including either distal pancreatectomy with splenectomy or splenic-preservation with ligation of the splenic vessels have also been described. We describe, herein, our method to perform spleen-preserving laparoscopic distal pancreatectomy that preserves the splenic vessels and hence splenic function. The described technique of spleen-preserving distal pancreatectomy has been used in two patients with favorable results. Both patients underwent laparoscopic distal pancreatectomy with splenic conservation for an oligocystic serous cystadenoma and serous cystadenoma. Operative time was 3–6 hours with total blood loss of less than 200 cc in both cases. The length of stay in the hospital was 4–8 days and both patients returned to work within 3 weeks. Laparoscopic spleen-preserving distal pancreatectomy should be considered for younger patientswith select body or tail lesions that are not candidates for less extensive procedures.

Solitary Fibrous Tumor of the Pancreas: A Case Report

Solitary fibrous tumor (SFT) is an unusual mesenchymal neoplasm that most often arises in the pleura; however, it has recently been described in a number of extrapleural sites. This report describes an extremely rare case of a benign SFT arising in the pancreas. A 41-year-old woman presented in the clinic with right upper abdominal pain. Subsequent ultrasonographic studies revealed a 1.5 × 1.5 × 1.4 cm hypoechoic mass within the pancreatic body, which was later confirmed on both helical computerized tomography and magnetic resonance imaging studies. An endocrine tumor was clinically suspected. Laparoscopic enucleation of the mass was performed. Microscopically, the tumor was composed of bland uniform spindle cells arranged between collagen bundles. On immunohistochemical studies, these spindle cells were positive for CD34 and bcl-2 but negative for cytokeratin (AE1+AE3 and Cam5.2), smooth muscle actin, desmin, S-100, and c-kit. Based on the light microscopic morphology and immunohistochemical staining profile, the diagnosis of SFT was rendered.

Laparoscopic Cyst Decortication Using the Harmonic Scalpel for Symptomatic Autosomal Dominant Polycystic Kidney Disease

BACKGROUND Management of acute and chronic pain in patients with autosomal dominant polycystic kidney disease (ADPKD) has, until recently, been limited to oral narcotic regimens, percutaneous drainage, open decortication, or nephrectomy. PATIENTS AND METHODS Five women and two men with a mean age of 44 (range 20-55) years underwent laparoscopic cyst decortication with the Harmonic Scalpel. All patients had end-stage renal disease secondary to ADPKD and pain attributed to their cyst disease. Two patients had simultaneous bilateral, one had staged bilateral, and remaining four patients had unilateral decortication. The mean follow-up was 14 months (range 2-29 months). Preoperative and postoperative pain was assessed using a standardized scale. RESULTS There were no intraoperative complication, and visible cysts were decorticated in a total of 10 renal units. There was a significant reduction in the pain scale, from a mean of 7.4/10 preoperatively to 2.3/10 on follow-up for the entire group (P < 0.0001). One patient reported recurrence of pain at 4 months, and bilateral nephrectomy was performed. Major complications included postoperative bleeding in two patients and readmission for ileus in one. CONCLUSION Laparoscopic decortication of painful renal cysts in ADPKD patients is a feasible procedure for symptomatic relief. The Harmonic Scalpel is a useful tool; however, it may not be adequate in preventing delayed bleeding.

Myocardial heat shock gene expression in pigs is dependent on superoxide anion generated at reperfusion.

The heat shock response is a conserved response to cell injury. We sought to determine if ischemia alone versus events at reperfusion stimulated expression of the major heat shock protein (hsp-72) in a clinically relevant model of global myocardial ischemia in pigs. Pigs were placed on nonpulsatile cardiopulmonary bypass. Serial transmural cardiac biopsies were taken at baseline following 20 min of normothermic global ischemia (induced by crossclamping the aorta) and at 20, 40, and 60 min of reperfusion. Test animals received a bolus and subsequent aortic root infusion of superoxide dismutase (total 7,500 U/kg) beginning just prior to reperfusion. Hsp-72 mRNA abundance was estimated from Northern blots. We found that hsp-72 mRNA was not induced following 20 min of ischemia but accumulated to high levels within 20 min of reperfusion. Intravascular administration of superoxide dismutase at reperfusion eliminated hsp-72 mRNA induction. We conclude that in the postischemic myocardium, hsp-72 gene expression is dependent on superoxide anion generation at reperfusion. In this setting, hsp-72 gene expression may reflect a specific response to oxidative injury rather than a more general response to metabolic stress associated with ischemia.

Pancreaticoduodenectomy in the presence of superior mesenteric venous obstruction

The study goal was to determine the technical feasibility and outcomes associated with pancreaticoduodenectomy for periampullary malignancies with near (>80%) or complete (100%) superior mesenteric venous (SMV) obstruction. A retrospective examination of 11 patients with high-grade or complete SMV obstruction who underwent pancreaticoduodenectomy at five academic medical centers is reviewed. Pancreaticoduodenectomy for locally advanced periampullary malignancies causing highgrade or complete SMV obstruction is technically feasible. Operative approaches and outcomes are presented. One 30-day death was observed. Median survival of the cohort is 18 months. Survivals exceeding 2 years post-resection have been observed. In a number of cases, significant palliation of pain and of biliary and duodenal obstruction were achieved. Based on this initial series, pancreaticoduodenectomy in the presence of near or total SMV obstruction is feasible, may result in an R0 resection, and may be beneficial in select patients with a periampullary malignancy. We suggest such an approach be considered particularly following completion of neoadjuvant therapy without systemic progression. Further studies and more long-term follow-up at high-volume centers are required, however, to better determine the indications and potential benefit of such an undertaking.

G207, modified herpes simplex virus type 1, kills human pancreatic cancer cells in vitro.

Pancreatic cancer is often fetal, and farther effective therapeutic options are needed. This study was designed to assess whether the replication-restricted herpes simplex virus, G207, was effective in killing human pancreatic cancer cells in vitro. G207, a multimutated strain of herpes simplex virus type 1 carrying lacZ reporter gene, is capable of efficient cytolytic growth in many dividing cells, including certain tumor cells, but not in nondividing cells. Three human pancreatic cell lines, AsPC-1, MIA PaCa-2, and BxPC-3, were infected with G207 at different multiplicities of infection. After 24 hours, expression of the lacZ reporter gene was tested using a histochemical X-gal assay. In addition, cell lines were infected with G207 for 24 to 48 hours; then the virus obtained from cell pellets and media supernatant was used to infect Vero cells to obtain G207 titers by plaque assay. To assess whether increasing viral immediate early gene expression would improve cytolysis and virus production, similar experiments were performed with the addition of 0.5 mmol/L of hexamethylene bisacetamide (HMBA) 1 hour after viral infection. Finally, MTS cell viability assays were performed to measure viable cells at 24 to 96 hours post infection. The X-gal assay data revealed a viral dose-dependent β-galactosidase expression, indicating G207 infectivity and expression of the lacZ reporter gene. Plaque assays demonstrated a viral dose-dependent increase in plaque formation, indicating viral production from all three cell lines. In addition, HMBA data indicated a modest increase in viral production. The MTS assay data indicated a dose-dependent cytotoxicity for G207 in the cell lines tested. G207 infects, replicates in, and is cytotoxic to the above-listed human pancreatic cell lines in vitro and warrants therapeutic evaluation in models of pancreatic cancer.

Regulation of Acute Phase Gene Expression Following Surgery and Endotoxin Administration in the Anesthetized Pig

BackgroundThe hepatic acute phase response (APR) reflects an organisms integrated response to stress. This APR results in augmented synthesis and secretion of specific procoagulants and antiproteases and a complementary decrease in the synthesis and secretion of several constitutive proteins, such as albumin. The cytokines tumor necrosis factor (TNF) or inter-leukin-6 (IL-6) have been identified as proximal mediators of the APR in response to endotoxin stress. The authors hypothesized that TNF, IL-6, or both would be the proximal mediators of the APR in response to anesthesia and surgical stress. MethodsThe effects of a standardized surgical stress on the APR in pigs under general anesthesia with sodium pentobarbital and ketamine hydrochloride was investigated. Acute phase gene transcription was assayed in nuclei from serial liver biopsies obtained before and after 2.5 h of surgical stress, and after endotoxin administration. Tumor necrosis factor and IL-6 mRNA levels in this liver tissue were examined by Northern blot hybridization, and simultaneous plasma levels of these cytokines were measured using bioassays. ResultsThe transcription rates of three positive acute phase genes—chymotrypsin inhibitor, inter-α-trypsin inhibitor and β-fibrinogen—increased seven-, six-, and twofold, respectively (P < 0.05), and the transcription rate of albumin, a negative acute phase gene, decreased to 34% of baseline (P < 0.01) during the 2.5 h of anesthesia and surgical stress. During this initial 2.5 h, plasma concentrations of TNF and IL-6 did not change. Hepatic IL-6 mRNA expression was never observed, and TNF mRNA expression was undetectable in six of seven pigs. Subsequent 10-μg/kg endotoxin administration caused 20-and 100-fold increases in plasma concentrations of TNF and IL-6, respectively (P < 0.01), and were associated with substantial hepatic expression of the TNF and IL-6 mRNAs. These increments in cytokines were not associated with any further increase in the acute phase gene transcription rates. Thus, the APR was initially regulated at the transcriptional level during surgical stress Independent of, and not augmentable by, an endotoxin-provoked increase in either plasma levels or hepatic mRNA expression of TNF or IL-6. ConclusionsSurgical stress induced hepatic acute phase gene transcription within 2.5 h in the absence of either systemic or local (hepatic) increases in TNF or IL-6. Subsequent endotoxin-induced Increases in TNF or IL-6 did not alter this surgical stress-induced acute phase gene transcription.

The quick, No-Twist, No-Kink portal confluence reconstruction

An aggressive surgical approach remains the best palliation and chance for 5-year survival in the treatment of locally advanced pancreatic cancer. Increasingly, this approach has involved partial or total resection of the portal vein (PV) or superior mesenteric vein (SMV) in combination with pancreaticoduodenectomy. Many studies have suggested that such resections done successfully are associated with an increased survival relative to nonresected patients, comparable with that of patients undergoing uncomplicated pancreaticoduodenectomy alone. Successful performance of portal resection remains extremely challenging because of the risk of uncontrolled bleeding and the difficulty encountered in preventing twisting or kinking of the reconstructed vessel. Prolonged partial or complete portal and mesenteric venous occlusion generally result in the development of bowel edema that makes the subsequent reconstruction more difficult. Recently, we and others have examined results of an aggressive surgical approach in the treatment of locally advanced pancreatic carcinoma. In our series, 43% of patients underwent partial portal vein resection with minimal additional blood loss, operative time, and postoperative complications, including pancreatic fistulae (unpublished observation). Our technique of portal vein resection, which preserves the anatomic relationship of the vessels in that region, allowing an easier reconstruction without kink or rotation of the portal-mesenteric confluence, is presented.