Escherichia coli cellular responses to exposure to atmospheric-pressure dielectric barrier discharge plasma-treated N-acetylcysteine solution.

AIM: To understand the underlying cellular mechanisms during inactivation of Escherichia coli in response to antimicrobial solution of nonthermal plasma-activated N-acetylcysteine (NAC). METHODS AND RESULTS: The recommended techniques were used to demonstrate E. coli cellular and transcriptomic changes caused associated with peroxynitrite and compared with plasma-treated NAC solution. The findings demonstrate that E. coli cells respond to plasma-treated NAC and undergo severe oxidative and nitrosative stress, and leading to stress-induced damages to different components of bacterial cells, which includes loss of membrane potential, formation of oxidized glutathione (GSSG), formation of nitrotyrosine (a known marker of nitrosative stress), DNA damage, and generated a prominent pool of peroxynitrite. Reverse-transcriptase (RT)-polymerase chain reaction analysis of reactive nitrogen species (RNS) responsive genes indicated their differential expressions. CONCLUSION: For the first time, we report that the plasma-treated NAC solution activates predominantly nitrosative stress-responsive genes in E. coli and is responsible for cell death. SIGNIFICANCE AND IMPACT OF THE STUDY: The reactive species generated in solutions by nonthermal plasma treatment depends on the type of solution or solvent used. The plasma-treated NAC solution rapidly inactivates E. coli, mostly involving highly RNS generated in NAC solution, and has high potential as disinfectant.

Withanolide E sensitizes renal carcinoma cells to TRAIL-induced apoptosis by increasing cFLIP degradation.

Withanolide E, a steroidal lactone from Physalis peruviana, was found to be highly active for sensitizing renal carcinoma cells and a number of other human cancer cells to tumor necrosis factor-related apoptosis-inducing ligand (TRAIL)-mediated apoptosis. Withanolide E, the most potent and least toxic of five TRAIL-sensitizing withanolides identified, enhanced death receptor-mediated apoptotic signaling by a rapid decline in the levels of cFLIP proteins. Other mechanisms by which TRAIL sensitizers have been reported to work: generation of reactive oxygen species (ROS), changes in pro-and antiapoptotic protein expression, death receptor upregulation, activation of intrinsic (mitochondrial) apoptotic pathways, ER stress, and proteasomal inhibition proved to be irrelevant to withanolide E activity. Loss of cFLIP proteins was not due to changes in expression, but rather destabilization and/or aggregation, suggesting impairment of chaperone proteins leading to degradation. Indeed, withanolide E treatment altered the stability of a number of HSP90 client proteins, but with greater apparent specificity than the well-known HSP90 inhibitor geldanamycin. As cFLIP has been reported to be an HSP90 client, this provides a potentially novel mechanism for sensitizing cells to TRAIL. Sensitization of human renal carcinoma cells to TRAIL-induced apoptosis by withanolide E and its lack of toxicity were confirmed in animal studies. Owing to its novel activity, withanolide E is a promising reagent for the analysis of mechanisms of TRAIL resistance, for understanding HSP90 function, and for further therapeutic development. In marked contrast to bortezomib, among the best currently available TRAIL sensitizers, withanolide E's more specific mechanism of action suggests minimal toxic side effects.

Resection of the sciatic, peroneal, or tibial nerves: assessment of functional status.

BACKGROUND: Lower-extremity tumors are often treated by amputation rather than limb-sparing excision that sacrifices the sciatic nerve or a branch. This study assessed the functional outcome of major nerve sacrifice during limb-sparing resections for lower-extremity soft tissue sarcoma. METHODS: Patients who underwent division of the sciatic, tibial, or peroneal nerve(s) during limb-sparing sarcoma surgery (January 1982 through June 2000) were identified. Eleven surviving patients evaluated their pre- and postoperative functional status by self-administered questionnaire (six sciatic, two tibial, and three peroneal nerve divisions). RESULTS: Eighteen patients (10 male, 8 female; 14-84 years old) had nine primary and nine locally recurrent tumors. Tumors were high (16) or low grade (two). Five patients died of disease and two died of other causes. Median overall survival was 50 months. One of 11 reported increased pain. Eight had new phantom sensations with a median intensity of 4.5 (1 = least; 10 = most). All patients used an ankle brace to walk after a sciatic (four) or peroneal (one) division. Walking ability and distance after surgery was unchanged (nine), improved (one), and worsened (one). Standing improved in 7 of 11 patients. Proprioception in the affected extremity was retained in six. The median postoperative leg functional score was 8 (1 = worst; 10 = best). No patient developed foot ulcers. One patient underwent amputation for recurrence. All patients preferred their status over having an amputation. CONCLUSIONS: Objectively and subjectively, division of the major lower-extremity nerves causes acceptable functional deficits in most patients. Resection of affected sciatic nerve (branches) during limb-sparing tumor surgery is an excellent alternative to amputation.

The search for level I evidence in solid-tumor oncology.

BACKGROUND: We have developed a method to identify, filter, review, and distribute the published level I evidence for solid tumor oncology. METHODS: A standardized MEDLINE search identified prospective randomized controlled trials (PRCTs) in solid tumor oncology. Only PRCTs with therapeutic end points were included. All references were reviewed by a surgical oncology fellow in consultation with experts in the field. The full citations were imported into a comprehensive database. Data on statistical methods according to the Consolidated Standard of Reporting Trials statement were tabulated along with reviewer's comments. A designation of Ia was given to articles that were well designed and significant contributions to their field. The database powers a dynamic, easily searchable Web site on our intranet and is available in personal digital assistant (PDA) format. RESULTS: By using standard search criteria, only .03% of the 11 million articles listed in MEDLINE are PRCTs concerning therapy for solid organ malignancies. Approximately 14% of reviewed articles were given a designation of Ia. Having comprehensive data readily available with intranet access or PDAs during conferences enhances their educational value and specificity. CONCLUSIONS: We have developed an exciting tool that uses a highly trained filter to screen and record the medical data available to the clinician. This information has been made available and portable by using the Internet and PDAs.

Soft tissue sarcomas of the groin: diagnosis, management, and prognosis.

BACKGROUND: Sott tissue sarcomas (STS) of the groin may present a difficult problem because or misdiagnosis as groin hernia and proximity to major neurovascular structures. We evaluated our management and survival in a large cohort of patients. STUDY DESIGN: Patients treated between July 1, 1982 and July 1, 1998 with primary or recurrent STS of the groin were included. Groin sarcomas were defined as those tumors within 5 cm of the inguinal crease. Patient, tumor, clinical, and survival data were analyzed using a log rank test and Cox regression. RESULTS: We treated and followed 88 patients with STS of the groin. The median age was 52 years (range 16 to 86 years) and 55 patients (63%) were male. Disease-specific survival was 72% at 5 years. Tumors tended to be larger than 5 cm (52%), deep (72%), and high-grade (60%). Unfavorable prognostic factors for disease-specific survival were high grade (p < 0.001), neurovascular invasion (p < 0.001), positive margin (p < 0.01), deep depth (p < 0.01), and selection for adjuvant therapy (p < 0.005). Multivariate analysis indicated age greater than 50 years (p < 0.05), high grade (p < 0.001), neurovascular invasion (p < 0.001), and positive microscopic margins (p < 0.001). Fourteen patients (16%) were diagnosed with STS at hernia operation then went on to a definitive operation with no impact on survival. Seventeen patients (19%) had involvement of a major vessel or nerve, and 5 of these ultimately required amputations, 3 for local recurrence. CONCLUSIONS: High grade, neurovascular invasion, and positive microscopic margins are associated with poor outcomes. The biology of these tumors is similar to other extremity STS, and similar principles of management apply. Even with neurovascular involvement, most patients with primary groin STS do not require amputation.

Role of fine-needle aspiration biopsy and frozen section analysis in the surgical management of thyroid tumors.

INTRODUCTION: The role of fine-needle aspiration (FNA) and frozen section (FS) in the management of thyroid neoplasms continues to generate considerable controversy. We reviewed our recent experience to determine the clinical utility of FNA and FS in our surgical management and intraoperative decision-making. METHODS: All patients who had operations for thyroid disease between January 1996 and June 1999 were identified in our prospective database. Completion and incidental thyroidectomies were excluded. Data obtained from the pathology files included FNA, FS, and the final histologic diagnosis. RESULTS: Five hundred sixty-four patients, including 409 women (73%), with a median age of 50 years (range, 6-94) were identified, of whom 293 (52%) had cancer diagnosed on permanent sections. Three hundred twenty-nine patients (58%) had evaluable FNA, of which 91 (28%) were benign, 94 were malignant (28%), and 144 (44%) were suspicious (46% of these were malignant on final). Frozen section was performed in 397 (70%) patients; of these samples, 170 (43%) were found to be benign, 106 (27%) were malignant, and 121 (30%) were deferred (46% malignant on final). Fine-needle aspiration positively identified 51% of confirmed malignancies; 13% of patients with malignancy had a benign FNA result. Total thyroidectomy was performed in 64% of malignant tumors and 29% of benign thyroid disease (P < .001). Logistic regression revealed no association of extent of surgery with FNA results. A frozen section positive for malignancy was associated with total thyroidectomy (P < .001, RR 6 [CI 3-10]), and a negative frozen section report was associated with lobectomy (P < .05, RR 0.5 [CI 0.3-0.96]). Frozen sections results altered the preoperative plan in only 29 patients (5%). CONCLUSION: Results of preoperative FNA had no direct impact on the selection of the surgical procedure in this selected cohort. Intraoperative FS added very little to surgical management. The majority of thyroid operations at this institution are planned and performed based on known prognostic factors and intraoperative findings.

Specific organ gene transfer in vivo by regional organ perfusion with herpes viral amplicon vectors: implications for local gene therapy.

BACKGROUND: Many gene therapy strategies would benefit from efficient, regional organ delivery of therapeutic genes. METHODS: Regional perfusions of lung, liver, or bladder were performed to determine if rapid and efficient gene transfer can be accomplished in vivo, and to determine if in vivo gene transfer can be limited to the organ of interest. In addition, herpes simplex virus tumor necrosis factor (HSVtnf), carrying the human tumor necrosis factoralpha gene was used as a treatment for methylcholanthrene sarcoma in a syngeneic lung metastases model in Fisher rats. RESULTS: A 20-minute perfusion using HSV carrying beta-galactosidase (HSVlac) produced significant expression of this marker gene isolated to the target organs, without organ-specific tissue injury or inflammation. Regional perfusion of organs with HSV carrying the cytokine gene tumor necrosis factor alpha also resulted in high-level local organ production of this cytokine (2851 +/- 53 pg/g tissue in perfused lung versus 0 for the contralateral lung). For the current vector construct, expression of the gene of interest peaked between 2 and 4 days and was undetectable by 2 weeks after perfusion. In animals undergoing perfusion as treatment for pulmonary sarcoma, there was no difference between tumor counts in lungs perfused with HSVlac (17 +/- 6) or HSVtnf (22 +/- 8), but either treatment resulted in lower tumor counts than controls (111 +/- 24 nodules per lung, P <.02). CONCLUSIONS: Regional organ perfusion using herpes viral vectors is an effective and well-tolerated in vivo method of transiently delivering potentially toxic gene products to target organs in directing gene therapy. Regional lung perfusion with HSV amplicons reduces tumor burden in a rat model of pulmonary metastases, though HSVtnf cannot be demonstrated to augment the cytopathic effect of the HSV amplicon alone in the current model.

The restricted expression of granzyme M in human lymphocytes.

We have analyzed the expression of human granzyme M (Gzm M) in various human leukocyte subsets using the specific mAb 4H10. Using FACS and Western blotting analysis we compared the expression of Gzm M with that of other granzymes (Gzm A and Gzm B) and the lytic protein perforin. Human Gzm M was constitutively highly expressed in NK cells as was perforin and Gzm A. Surprisingly, freshly isolated NK cells had very low (sometimes undetectable) levels of Gzm B. In contrast to Gzm B and perforin, Gzm M was not detected in highly purified CD4(+) and CD8(+) T cells either constitutively or after short term activation in vitro. However, low levels of Gzm M were observed in some T cell clones on prolonged passage in vitro. Gzm M was not detected in highly purified neutrophils, monocytes, or tumor cells of the myelomonocytic lineage. Examination of minor T cell subsets from human peripheral blood showed detectable Gzm M in CD3(+), CD56(+) T cells and gammadelta T cells. A histological staining procedure was developed that demonstrated a granular staining pattern for Gzm M and a cellular distribution similar to that observed by Western blotting. These data indicate that the expression of Gzm M does not always correlate with the lytic activity of cytotoxic cells. However, expression of Gzm M in NK cells, CD3(+), CD56(+) T cells, and gammadelta T cells suggests that this enzyme may play some role in innate immune responses.

Surgical debulking and intraperitoneal chemotherapy for established peritoneal metastases from colon and appendix cancer.

BACKGROUND: Aggressive treatment of peritoneal metastases from colon cancer by surgical cytoreduction and infusional intraperitoneal (IP) chemotherapy may benefit selected patients. We reviewed our institutional experience to assess patient selection, complications, and outcome. METHODS: Patients having surgical debulking and IP 5-fluoro-2'-deoxyuridine (FUDR) plus leucovorin (LV) for peritoneal metastases from 1987 to 1999 were evaluated retrospectively. RESULTS: There were 64 patients with a mean age of 50 years. Primary tumor sites were 47 in the colon and 17 in the appendix. Peritoneal metastases were synchronous in 48 patients and metachronous in 16 patients. Patients received IP FUDR (1000 mg/m2 daily for 3 days) and IP leucovorin (240 mg/m2) with a median cycle number of 4 (range, 1-28). The median number of complications was 1 (range, 0-5), with no treatment related mortality. Only six patients (9%) required termination of IP chemotherapy because of complications. The median follow-up was 17 months (range, 0-132 months). The median survival was 34 months (range, 2-132); 5-year survival was 28%. Lymph node status, tumor grade, and interval to peritoneal metastasis were not statistically significant prognostic factors for survival. Complete tumor resection was significant on multivariate analysis (P = .04), with a 5-year survival of 54% for complete (n = 19) and 16% for incomplete (n = 45) resection. CONCLUSIONS: Surgical debulking and IP FUDR for peritoneal metastases from colon cancer can be accomplished safely and has yielded an overall 5-year survival of 28%. Complete resection is associated with improved survival (54% at 5 years) and is the most important prognostic indicator.

Inhaled aerosolization of all-trans-retinoic acid for targeted pulmonary delivery.

Retinoids have shown promising activity for both cancer chemoprevention and as a treatment for emphysema. However, chronic oral administration of these drugs is limited by systemic side effects, including hepatic dysfunction, skeletal malformations, hyperlipidemia. hypercalcemia, and other reactions. In order to improve the pulmonary targeting of this potentially useful therapy, we developed a system for aerosolization of retinoids that substantially increased their local bioavailability. We compared the biodistribution and pharmacokinetics of an inhaled formulation of all-trans-retinoic acid (all-trans-RA), which was packaged in a metered dose inhaler, following both intratracheal (IT) and intravenous (IV) administration in male Sprague-Dawley rats. After drug administration, anesthetized animals were killed at 5 min, and at 1, 2, 4, 6 and 24 h. Plasma and emulsified samples of liver and lung tissues were dissected, extracted, and frozen prior to measurement of all-trans-RA concentration by high-performance liquid chromatography (HPLC). Aerosolization and IT injection of all-trans-RA resulted in a significantly longer pulmonary half-life of the drug (both 5-17 h), lower peak serum concentrations (aerosol 71 +/- 31 ng/ml, IT 68 +/- 50 ng/ml), and lower liver levels (aerosol 111 +/- 28 ng/g, IT 753 +/- 350 ng/g) than the same dose administered IV (2 h, 838 +/- 56 ng/ml, 4,258 +/- 1,006 ng/g, respectively; P < 0.05 for each comparison). Histologic examination of lungs and trachea showed no focal irritation attributable to the drug after single-dose administration. These results suggest that aerosolization of retinoids may offer a practical alternative to systemic oral administration for chemoprevention trials or treatment of lung diseases. This method may substantially increase the therapeutic index of these compounds by reducing systemic complications associated with long-term dosing.

Decreasing length of stay after pancreatoduodenectomy.

HYPOTHESIS: Decreased length of stay (LOS) after pancreatoduodenectomy is due to multiple factors, including a lower complication rate and more efficient perioperative care for all patients, with and without complications. DESIGN: A retrospective review, validation cohort. SETTING: A single university hospital referral center. PATIENTS: A consecutive sample of patients undergoing pancreatoduodenectomy from January 9, 1986, to December 21, 1992 (group 1 [n = 104]) and from February 16, 1993, to November 9, 1998 (group 2 [n = 111]). INTERVENTION: Mann-Whitney test and linear [correction of logistic] regression analysis applied to clinical variables and LOS. MAIN OUTCOME MEASURES: Difference in median LOS between early and late groups and identification of factors predictive of decreased LOS. RESULTS: Total LOS decreased between the 2 groups (26 days [range, 13-117 days] vs 15 days [range, 5-61 days]; P<.001), with a decrease in preoperative (4 days [range, 0-28 days] vs 2 days [range, 0-36 days]; P<.001) and postoperative (19 days [range, 11-95 days] vs 12 days [range, 4-58 days]; P<.001) LOS (data given for group 1 vs group 2). Major complications decreased from 49% in group 1 to 25% in group 2 (P<.001). Postoperative LOS decreased for patients with (25 days [range, 15-95 days] vs 20 days [range, 8-58 days]; P = .05) and without (15 days [range, 11-47 days] vs 11 days [range, 4-55 days]; P<.001) major complications (data given for group 1 vs group 2). Multivariate analysis identified age (P = .01), pancreatic fistula (P<.001), delayed gastric emptying (P<.001), biliary complications (P<.001), operative time (P<.005), extra-abdominal infection (P<.005), use of a percutaneous stent (P = .04), and year of operation (P<.001) as independent predictors of total LOS. CONCLUSION: A reduction in complications in combination with factors leading to a streamlining of perioperative care has contributed to the decreased LOS after pancreatoduodenectomy.

T cell lysis of murine renal cancer: multiple signaling pathways for cell death via Fas.

Activated T cells lyse the murine renal cancer Renca. We have examined the mechanism of tumor cell lysis with the use of T cells derived from C57BL/6, BALB/c, B6.gld, and B6.Pfp-/- mice. C57BL/6 and BALB/c T cells can lyse Renca cells through the use of both granule- and Fas ligand (FasL)-mediated pathways. However, B6.gld T cells predominantly use granule-mediated killing, whereas B6.Pfp-/- T cells use FasL. The lysis of Renca by Pfp-/- T cells is only partially inhibited by the caspase inhibitor ZVAD-FMK, suggesting that caspase-independent signaling is also important for Renca cell lysis. When the reactive oxygen scavenger butylated hydroxyanisole was used alone or in combination with ZVAD-FMK a substantial reduction of Renca lysis was observed. Therefore, the caspase-independent generation of reactive oxygen intermediates in Renca after Fas triggering contributes to the lysis of these cells.

IFN-gamma-dependent delay of in vivo tumor progression by Fas overexpression on murine renal cancer cells.

The role of Fas in the regulation of solid tumor growth was investigated. Murine renal carcinoma (Renca) cells were constitutively resistant to Fas-mediated killing in vitro, but exhibited increased expression of Fas and sensitivity to Fas-mediated killing after exposure to IFN-gamma and TNF. Transfected Renca cells overexpressing Fas were efficiently killed in vitro upon exposure to anti-Fas Ab (Jo2). When Fas-overexpressing Renca cells were injected into syngenic BALB/c mice, there was a consistent and significant delay in tumor progression, reduced metastasis, and prolonged survival that was not observed for Renca cells that overexpressed a truncated nonfunctional Fas receptor. The delay of in vivo tumor growth induced by Fas overexpression was not observed in IFN-gamma-/- mice, indicating that IFN-gamma is required for the delay of in vivo tumor growth. However, there was a significant increase of infiltrated T cells and in vivo apoptosis in Fas-overexpressing Renca tumors, and Fas-overexpressing Renca cells were also efficiently killed in vitro by T cells. In addition, a strong therapeutic effect was observed on Fas-overexpressing tumor cells by in vivo administration of anti-Fas Ab, confirming that overexpressed Fas provides a functional target in vivo for Fas-specific ligands. Therefore, our findings demonstrate that Fas overexpression on solid tumor cells can delay tumor growth and provides a rationale for therapeutic manipulation of Fas expression as a means of inducing tumor regression in vivo.

Complications of level I and II axillary dissection in the treatment of carcinoma of the breast.

OBJECTIVE: To assess the complications of level I and II axillary lymph node dissection in the treatment of stage I and II breast cancer, with breast-conservation surgery and mastectomy. SUMMARY BACKGROUND DATA: The role of axillary dissection for staging, and as an effective means of controlling regional nodal disease, has long been recognized. As small and low-grade lesions have been detected more frequently, and as its therapeutic impact has been questioned, axillary dissection has increasingly been perceived as associated with significant complications. METHODS: Two hundred patients, 112 of whom had breast-conservation surgery with axillary dissection and 88 of whom had total mastectomy with axillary dissection, were evaluated 1 year or more after surgery for arm swelling as well as nonedema complications. All patients had arm circumference measurements at the same four sites on both the operated and nonoperated sides. RESULTS: No patient had an axillary recurrence. The mean difference in circumference on the nonoperated versus operated side was 0.425 cm +/- 1.39 at the midbiceps (p < 0.001), 0.315 cm +/- 1.27 at the antecubital fossa (p < 0.001), 0.355 cm +/- 1.53 at the midforearm (p < 0.005), and 0.055 cm +/- 0.75 at the wrist (n.s.). Seven patients (3.5%) had mild swelling of the hand. Heavy and obese body habitus were the only significant predictors of edema on multivariate analysis. One hundred fifty-three (76.5%) patients had numbness or paresthesias of the medial arm and/or axilla after surgery; in 125 (82%) of these, the problem had lessened or had resolved on follow-up assessment. CONCLUSIONS: The characterization of a level I and II axillary dissection as a procedure with significant complications does not appear justified based on this experience.

The management of unicentric and multicentric Castleman's disease: a report of 16 cases and a review of the literature.

BACKGROUND: Castleman's disease (CD), or angiofollicular lymph node hyperplasia, creates both diagnostic and therapeutic dilemmas for most physicians. For patients with this rare and poorly understood disease, the optimal therapy is unknown. The authors report their experience during the years 1986-1997 with this uncommon clinicopathologic entity. METHODS: Sixteen patients with a histologic diagnosis of CD were identified in the pathology database. Unicentric disease was defined as a solitary mass. Multicentric disease compromised patients with widespread lymphadenectomy. Clinical, radiologic, and laboratory data were analyzed to evaluate treatment response. RESULTS: The study group consisted of 16 patients classified into 3 clinicopathologic groups: hyaline-vascular, plasma cell, and "mixed." Of those patients who underwent complete surgical excision of a unicentric hyaline-vascular CD mass (n = 8), all remain symptom free without clinical or radiographic recurrence. Two patients remain asymptomatic following partial resection or radiation therapy for an unresectable unicentric hyaline-vascular CD mass. Two patients with multicentric hyaline-vascular CD are currently in complete remission following adjuvant therapy. Multicentric plasma cell CD was present in a single patient. This patient (who underwent surgical and systemic therapy) died of disease within 4 months of presentation. Three patients with unicentric hyaline-vascular/plasma cell-CD remain symptom free following either complete resection or observation. CONCLUSIONS: The authors recommend surgical resection for patients with the unicentric variant of CD. Surgical removal of a unicentric mass of hyaline-vascular or hyaline-vascular/plasma cell type is curative. Partial resection, radiotherapy, or observation alone may avoid the need for excessively aggressive therapy. Patients with multicentric disease, either hyaline-vascular or plasma cell type, do not benefit from surgical management and should be candidates for multimodality therapy, the nature of which has yet to be defined.

Intestinal permeability after early postoperative enteral nutrition in patients with upper gastrointestinal malignancy.

BACKGROUND: Increased intestinal permeability may lead to sepsis in resected upper gastrointestinal (GI) cancer patients. This study sought to determine whether these patients demonstrated increased intestinal permeability and if early postoperative enteral nutrition would alter this result. METHODS: Nineteen patients undergoing complete resection of upper GI malignancy were randomized into two groups: the nonfed group received IV crystalloid, and the fed group started enteral nutrition by jejunostomy on postoperative day (POD) 1. Six nonoperative volunteers were controls. The lactulose/mannitol test was performed on PODs 1 and 5. Ten grams of lactulose and 5 g of mannitol were given, and urine was collected for 6 hours. RESULTS: All patients (nonfed, 1.895+/-0.34; fed, 0.893+/-0.24) had elevated lactulose/mannitol ratios on POD 1 vs controls (0.262+/-0.1; p < .008 and p = .05). These elevated levels returned toward control levels in both groups by day 5 (nonfed, 0.533+/-0.1, p = .06; fed, 0.606+/-0.12, p = .08). CONCLUSIONS: Major upper GI surgery for malignancy resulted in a significant increase in intestinal permeability on POD 1. With or without enteral nutrition, this measure of intestinal permeability returned to normal on POD 5 in well-nourished patients.

Is intra-abdominal drainage necessary after pancreaticoduodenectomy?

Closed suction drains after pancreaticoduodenectomy are theoretically used to drain potential collections and anastomotic leaks. It is unknown whether such drains are effective, harmful, or affect the outcome after this operation. Eighty-nine consecutive patients underwent pancreaticoduodenectomy for presumed periampullary malignancy and were retrospectively reviewed. Thirty-eight had no intra-abdominal drains and 51 had drains placed at the conclusion of the operation. We analyzed patient, nutritional, laboratory, and operating room factors with end points being complications and length of hospital stay. Intra-abdominal complications were defined as intra-abdominal abscess and pancreatic or biliary fistula. Postoperative interventions were defined as CT-guided drainage and reoperation. Analysis was by Student's t test and chi-square test. Two of eight surgeons contributed 92% of the patients without drains. The groups were equivalent with respect to demographic, nutritional, and operative factors. Time under anesthesia was significantly shorter in the group without drains (P = 0.0001). There was no statistical difference in the rate of fistula, abscess, CT drainage, or length of hospital stay. Intra-abdominal drainage did not significantly alter the risk of fistula, abscess, or reoperation or the necessity for CT-guided intervention after pancreaticoduodenectomy. Routine use of drains after pancreaticoduodenectomy may not be necessary and should be subjected to a randomized trial.

Molecular mechanisms of immune-mediated lysis of murine renal cancer: differential contributions of perforin-dependent versus Fas-mediated pathways in lysis by NK and T cells.

Mice bearing the experimental murine renal cancer Renca can be successfully treated with some forms of immunotherapy. In the present study, we have investigated the molecular pathways used by NK and T cells to lyse Renca cells. Renca cells normally express low levels of Fas that can be substantially enhanced by either IFN-gamma or TNF-alpha, and the combination of IFN-gamma + TNF-alpha synergistically enhances cell-surface Fas expression. In addition, cells pretreated with IFN-gamma and TNF-alpha are sensitive to lysis mediated by Fas ligand (FasL)-expressing hybridomas (dllS), cross-linking of anti-Fas Abs or soluble Fas (FasL). Lysis via Fas occurs by apoptosis, since Renca shows all the typical characteristics of apoptosis. No changes in levels of bcl-2 were observed after cytokine treatments. We also examined cell-mediated cytotoxic effects using activated NK cells and T cells from gld FasL-deficient mice, and perforin-deficient mice, as well as wild-type C57BL/6 and BALB/c mice. Interestingly, the granule-mediated pathway predominated in killing of Renca by activated NK cells, while the Fas/FasL pathway contributed significantly to cell-mediated killing of Renca by activated T cells. These results suggest that killing of Renca tumor cells by immune effector cells can occur by both granule and Fas-mediated cytotoxicity. However, for the Fas-mediated pathway to function, cell surface levels of Fas need to be increased beyond a critical threshold level by proinflammatory cytokines such as IFN-gamma and TNF-alpha.

Inhibition of Fas (CD95) expression and Fas-mediated apoptosis by oncogenic Ras.

The ras oncogene plays an important role in the multistep progression to cancer by activation of signal transduction pathways that contribute to aberrant growth regulation. Although many of these effects are cell autonomous, the ras oncogene also regulates the expression of genes that alter host/tumor interactions. We now extend the mechanisms through which ras promotes tumor survival by demonstrating that oncogenic Ras inhibits expression of the fas gene and renders Ras-transformed cells resistant to Fas-induced apoptosis. A panel of Ras-transformed clones exhibited a marked inhibition in fas mRNA and Fas cell surface expression as compared with untransformed parental cell lines. Fas expression was induced by culture in the presence of IFN-gamma + tumor necrosis factor alpha; however, the maximal level attained in Ras transformants was approximately 10-fold below the level of untransformed cells. Whereas untransformed cells were sensitive to apoptotic death induced by cross-linking surface Fas (especially after cytokine treatment), Ras-transformed cells were very resistant to Fas-induced death even under the most stringent assay conditions. To demonstrate that this resistance was mediated by oncogenic Ras and not secondary genetic events, pools of Ras-transformed cells were generated using a highly efficient retroviral transduction technique. Transformed pools were assayed 6 days after infection and demonstrated a marked decrease in fas gene expression and Fas-mediated apoptosis. Oncogenic Ras did not promote general resistance to apoptosis, because ectopic expression of a fas cDNA in Ras-transformed cells restored sensitivity to Fas-induced apoptosis. These data indicate that oncogenic Ras inhibits basal levels of expression of the fas gene, and although cytokine signal transduction pathways are functional in these cells, the level of surface Fas expression remains below the threshold required for induction of apoptosis. These data identify a mechanism by which Ras-transformed cells may escape from host-mediated immune destruction.

Superficial extremity soft tissue sarcoma: an analysis of prognostic factors.

BACKGROUND: Experience with soft tissue sarcoma has suggested that superficial tumors have a favorable prognosis. We evaluated the prognostic features of this subset of sarcoma. METHODS: Prospective data on 215 patients presenting to Memorial Sloan-Kettering Cancer Center with primary extremity superficial soft tissue sarcomas between July 1, 1982 and July 1, 1996 were analyzed. Superficial sarcomas were defined as subcutaneous tumors not invading the investing fascia of the muscle. Analysis was by univariate and multivariate tests for local recurrence, metastasis, and tumor mortality. RESULTS: Ninety (42%) patients were over 50 years of age, 115 (53%) had high-grade tumors, 53 (25%) had tumors > or = 5 cm, and 18 (8%) had positive margins following definitive resection. Median follow-up was 45 months (range 2 days to 151 months), 31 (14%) patients had local recurrences, 20 (9%) had distant metastases, and 15 (7%) died of disease. Five- and 10-year actuarial disease-specific survivals were 91% and 85%, respectively. On multivariate analysis, age > 50 years predicted local recurrence (RR 5.7; 95% CI, 2.4-13.3; p < 0.0001). High grade (RR 4.2; 95% CI, 1.4-12.7; p < 0.006), and size > or = 5 cm (RR 4.4; 95% CI, 1.8-11; p < 0.002) predicted distant metastases. High grade (RR 7; 95% CI, 1.5-31.4; p < 0.003), size > or = 5 cm (RR 6.9; 95% CI, 2.3-20.8; p < 0.0006), and positive margins (RR 3.8; 95% CI, 1.2-12.4; p < 0.006) predicted tumor mortality. CONCLUSION: Primary superficial extremity soft tissue sarcomas have a favorable prognosis. Size and grade of superficial tumors are the strongest factors in predicting survival.