CONCLUSIONS: GalT K/O swine lungs are significantly pro-tected from HALR. However lung HAR is triggered by Gal-independent mechanisms, and preventing it will require identifica-tion and control of pathways initiating intravascular coagulationcascade activation.

Ad.interferon beta is effective in a murineorthotopic model of bronchioloalveolar lung cancervia NK cell and CD8� T-cell mediated effectsMichael J Wilderman MD, Jing Sun MD, Anil Vachani MD,Paul Kinniry MD, Michael Silverberg BA, Daniel Sterman MD,Steven Albelda MD, Larry Kaiser MDHospital of the University of Pennsylvania, Philadelphia, PA

INTRODUCTION: An orthotopic mouse model for Bronchioloal-veolar Carcinoma(BAC) involving a conditionally expressed mu-tated Kras protein has recently been developed (Jackson et al,2001).We have shown in mesothelioma models that an adenovirual vectorexpressing interferon-beta (Ad.IFN-B) eradicates tumors. We hy-pothesized that Ad.IFN-B could be similarly effective in this model.

METHODS: Kras mutant mice were given Ad.Cre intra-nasally toactivate the oncogene. 3 and 4 weeks after Ad.Cre instillation, micewere either untreated or treated intra-nasally with 10e9 plaque form-ing units of Ad.LacZ or Ad.IFN-B. The mice were followed forsurvival. Cells derived from Kras mutated lung tumors were grown inthe flanks of mice to study mechanisms behind these responses.

RESULTS: Untreated tumor-bearing mice (n�8) all died by day57 (median survival 49 days). Ad.LacZ treated mice (n�8) all diedby day 71 (median survival 65 days). All mice treated with Ad.IFN-B(n�8) were long term survivors (�120 days)(p�0.001). This ex-periment was repeated with virtually identical results. In vitro andflank tumor studies demonstrated that Ad.IFN-B induced directtumor cell killing and that depleting natural killer(NK) or CD�8 Tcells, but not CD�4 T cells, with antibodies attenuated the effect ofAd.IFN-B.

CONCLUSIONS: Ad.IFN-B delivered into mice with establishedtumors led to remarkable anti-tumor activity in this model. Effectswere dependent on a combination of direct cell killing and activationof both NK cells and CD8� T cells. These studies provide strongpreclinical support for a trial of Ad.IFN-B to treat human BAC.

A synthetic Bcl-XL antagonist induces apoptosisand chemosensitization in malignant pleuralmesotheliomaPhilip A Rascoe MD, Jonathan Daniel MD, Xiaobo Cao MD,Jack Roth MD, Lin Ji PhD, W Roy Smythe MDMD Anderson Cancer Center, Houston, TX

INTRODUCTION: Malignant pleural mesothelioma (MPM) is of-ten amenable to local control via surgical resection and adjuvantradiation therapy. Treatment failure ultimately results fromchemotherapy-resistant micrometastatic disease. MPM express theanti-apoptotic protein Bcl-XL, and heterodimerization between

Bcl-XL and pro-apoptotic Bcl-2 family members results in resistanceto apoptosis and chemotherapy. BH3I-1 is a synthetic Bcl-XL antag-onist which inhibits Bcl-XL heterodimerization with pro-apoptoticproteins. We propose that BH3I-1 may initiate apoptosis and che-mosensitization of MPM.

METHODS: Human MPM cell lines I45 and REN were exposed toBH3I-1 alone and in combination with cisplatin. Cell viability wasdetermined by XTT assay. Apoptosis was assessed by fluorescence-activated cell sorter (FACS) determination of subdiploid popula-tions, and western blot determination of cleavage of caspases 3 and 9.Isobologram analysis was performed to determine if combinationtherapy was synergistic.

RESULTS: BH3I-1 alone resulted in decreased viability in both celllines by XTT, and an increase in the SubG0 population compared tocontrols as determined by FACS [I45: 14.5% vs. 5.2%, REN: 29.2%vs. 5.4%, p�0.05]. Western blot demonstrated cleavage of caspases 3and 9. Moreover, a subtherapeutic concentration of BH3I-1 sensi-tized both cell lines to cisplatin-induced apoptosis. Isobologramanalysis demonstrated a synergistic effect.

CONCLUSIONS: Exposure of MPM cells to a synthetic Bcl-XLantagonist leads to apoptotic cell death and sensitization to the che-motherapeutic agent cisplatin. Such agents may circumvent resis-tance to conventional chemotherapy currently experienced in theadjuvant treatment of mesothelioma.

Quantifying neointimal hyperplasia in aortocoronarysaphenous vein grafts using multichannel CTangiographyRobert Poston MD, Charles White MD, Katrina Read MD,Junyan Gu MD, Bartley Griffith MDUniversity of Maryland School of Medicine, Baltimore, MD

INTRODUCTION: The poor applicability of animal models of neo-intimal hyperplasia (NH) to coronary artery disease patients limitsour understanding of this process in the aortocoronary vein graft. Wedescribe a protocol that incorporates multidetector CT angiography(CTA) to help elucidate the underlying causes of NH after OPCAB.

METHODS: Vein graft patency was assessed in a prospective cohort of125 OPCAB patients on aspirin monotherapy using CTA prior to hos-pital discharge; midterm (1 to 1.5 years postoperatively) follow-up wasobtained in 19 patients. NH was defined by �25% graft diameter re-duction on mid-term vs. early CTA. Demographic and operative dataincluding graft flows were recorded. Endothelial disruption each graftwas determined by analyzing surplus vein segments for %luminal CD31staining. Aspirin resistance was determined by 4 assays perioperativelyand on postoperative days 1, 3, and 30.

RESULTS: Early failure occurred in 10 (4.5%) of 227 vein graftsand correlated with %endothelial disruption, aspirin resistance, andthe vein/target diameter ratio (p�0.05 for each). NH was detected in24 of 41 (59%) vein grafts on follow-up examination; none of thevariables analyzed correlated with the incidence or severity of NH.Arterial grafts, used in each patient, were all patent at both timepoints and showed no evidence of NH on follow-up examination.

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CONCLUSIONS: CTA provides a noninvasive and accurate meansof quantifying neointimal hyperplasia within saphenous vein grafts.Further analysis of patients enrolled in this ongoing trial will likelyhelp clarify the causes of NH after OPCAB.

Impaired cardiac stem cell function leads toattenuated myocyte turnover and prematuremyocardial aging in the W/WV mouseLindita Coku MD, Marcello Rota PhD, Brian Whang MD,Elena Padin-Iruegas MD, Claudia Bearzi PhD,Angelo Nascimbene MD, Stefano Cascapera PhD,Claudia Casarsa PhD, Elias Zias MD, Piero Anversa MDNew York Medical College, Valhalla, NY

INTRODUCTION: The objective of this study was to determinewhether attenuation of cardiac stem cell (CSC) growth interfereswith the physiologic cell turnover leading to precocious myocardialaging.

METHODS: For this purpose, W/WV mice displaying mutation ofthe c-kit receptor were analyzed at different ages and compared withwild-type mice (WT).

RESULTS: Cardiac anatomy was similar at 2.5 months. However,at 4 months, LV mass and volume were larger in W/WV. Similarly,number and size of LV myocytes were comparable at 2.5 months but,at 4 months W/WV myocytes displayed a 34% increase in volume.Echocardiography at 2.5 and 5.5 months, revealed no changes inWT, while in W/WV an increase in diastolic (29%) and systolic(30%) LV diameter with reduced EF was present. Similar differencesbetween W/WV and WT at 5.5 months were found. Since the vol-ume composition of the myocardium was not changed in W/WV, thehypothesis was advanced that myocyte homeostasis was affected,possibly mediated by growth defects in the CSC compartment. Inspite of the similar CSC density, in W/WV compared to WT, 2.3-fold more CSCs were p16INK4a positive and, thereby, withdrawnfrom the cell cycle. Additionally, p16INK4a was detected in 2.4-foldmore myocytes of W/WV. Importantly, BrdU, Ki67 and MCM5labeling of replicating myocytes was, respectively, 60%, 80% and56% lower in W/WV.

CONCLUSIONS: Mutation of the c-kit receptor impairs CSCgrowth and commitment to the myogenic lineage resulting in re-duced myocyte formation, accumulation of senescent parenchymalcells and development of an aging myopathy.

Biologically variable cardiopulmonary bypassenhances systemic perfusion and reduces renalinjury after deep hypothermic circulatory arrestRohit K Singal MD, Leanne Docking MD, Linda Girling BSc,Peter Nickerson MD, M Ruth Graham MD, Bruce McManus MD,Alex Magil MD, R Keith Warrian MD, W Alan Mutch MDUniversity of Manitoba, Winnipeg, MB Canada

INTRODUCTION: Biologically variable perfusion uses a computercontroller to restore healthy physiologic variation to roller pump flow

during cardiopulmonary bypass (CPB). We hypothesized that bio-logically variable CPB (BVC) would result in better systemic perfu-sion and renal function compared to continuous CPB (CC) in aporcine model following deep hypothermic circulatory arrest(DHCA).

METHODS: Eighteen pigs were randomized to receive either BVCor CC during cooling (1hr), DHCA at 18 degrees Celsius (1hr) andresumed CPB with rewarming using the randomized approach (3hr).Hemodynamics, acid-base status, body temperature, urine volumesand the following urinary markers of tubular injury: gamma glu-tamyl transpeptidase (GGT), alkaline phosphatase (AP) and gluta-thione s-transferase-alpha (GST), were measured. Mass spectrometryurine proteomics measured abnormal protein spectra over time be-tween groups.

RESULTS: BVC decreased cooling time to 21 � 9.0 min com-pared to 31.7 � 7.5 min in the CC group and decreased rewarmingto 22.1 � 3.9 min compared to 31.2 � 5.1 min in the CC group(p�0.002). Urine output post DHCA was 530 � 216 mL in theBVC group compared to 242 � 75 mL in the CC group (p�0.002).Urinary GGT and AP were markedly higher in the CC group at allpoints after DHCA (p�0.0007). Urine proteomics verified the pres-ence of abnormal proteins which persisted longer in the CC group.

CONCLUSIONS: Systemic and renal perfusion is superior withBVC as suggested by more rapid cooling and rewarming, improvedurinary output, decreased urinary markers of tubular injury and at-tenuated mass spectrometry urine proteomics.

Atorvastatin alters myocardial expression of VEGFand endostatin in hypercholesterolemic swine:implications for angiogenesisMunir Boodhwani MD, Yasunari Nakai MD, Pierre Voisine MD,Jian Li MD, PhD, Shu-Hua Xu PhD, Jun Feng MD, PhD,Cesario Bianchi MD, PhD, Senthil Nathan MD, Marc Ruel MD,Frank Sellke MD, FACSBeth Israel Deaconess Medical Center, Boston, MA

INTRODUCTION: HMG-CoA reductase inhibitors (statins) havebeen shown to restore endothelial function in coronary artery diseasepatients, but their effects on myocardial angiogenesis have not beenwell characterized. We investigated the influence of atorvastatin onthe endogenous angiogenic response in a hypercholesterolemic swinemodel of chronic myocardial ischemia.

METHODS: Yucatan pigs were fed either a normal (NORM, n�7)or high cholesterol diet, with (CHOL-ATR, n�7) or without(CHOL, n�6) atorvastatin (3mg/kg/day) for 13 weeks. Chronicischemia was induced by ameroid constrictor placement around thecircumflex (LCx) artery. Seven weeks later, endothelial-dependentmicrovessel relaxation responses, myocardial perfusion, and myocar-dial protein expression was assessed.

RESULTS: Hypercholesterolemic swine (CHOL) demonstratedimpaired microvessel relaxation to endothelium-dependent vasodila-tor adenosine diphosphate (29�3% vs. 61�6%, CHOL vs.NORM, p�0.05), which was normalized in the CHOL-ATR group

S26 Cardiothoracic Surgery II J Am Coll Surg