THE EVALUATION OF PRE AND POST PROCESSING SEMEN ANALYSIS PARAMETERS AT THE TIME OF INTRA-UTERINE INSEMINATION IN COUPLES DIAGNOSED WITH MALE FACTOR INFERTILITY Dahan, Michael Agbo, Chioma TROPONIN I: TIME-TO-POSITIVITY IN EMERGENCY DEPARTMENT PATIENTS WITH ACUTE MYOCARDIAL INFARCTION

s for these projects are located online at: http://med.stanford.edu/student_research/events.html#symposium Student Name Project Title Faculty Mentor Agbo, Chioma THE EVALUATION OF PRE AND POST PROCESSING SEMEN ANALYSIS PARAMETERS AT THE TIME OF INTRA-UTERINE INSEMINATION IN COUPLES DIAGNOSED WITH MALE FACTOR INFERTILITY Dahan, Michael Agbo, Chioma TROPONIN I: TIME-TO-POSITIVITY IN EMERGENCY DEPARTMENT PATIENTS WITH ACUTE MYOCARDIAL INFARCTION Schreiber, Donald Baras, Jacqueline THE RELATIONSHIP BETWEEN MRI AVAILABILITY AND LOW BACK PAIN CARE UTILIZATION Baker, Laurence Bauer Huang, Sarah IDENTIFICATION OF PERIPHERAL AND CNS SIGNALING PROTEINS ASSOCIATED WITH ALZHEIMER'S DISEASE Wyss-Coray, Tony Chan, Stephanie A BAYESIAN NETWORK TO ASSIST MAMMOGRAPHY INTERPRETATION Rubin, Daniel Chang, Pearl ROLE OF MHC CLASS I MOLECULES IN THE PATHOGENESIS OF AUTOIMMUNE DIABETES Fathman, C. Garrison Chiu, Richard POLYMETHYLMETHACRYLATE PARTICLES INHIBIT EXPRESSION OSTEOGENIC TRANSCRIPTION FACTORS RUNX2, OSTERIX, DLX5 Goodman, Stuart Chiu, Richard POLYMETHYLMETHACRYLATE PARTICLES IMPAIR OSTEOPROGENITOR VIABILITY BY CELL NECROSIS NOT APOPTOSIS Goodman, Stuart Chiu, Richard ONCOLOGIC AND FUNCTIONAL RESULTS OF GRADE 1 CHONDROSARCOMAS AND ENCHONDROMAS Mohler, David Chun, Carlene LONGITUDINAL INVESTIGATION OF CANCER BIOMARKER EXPRESSION LEVELS PREAND POST-CHEMORADIOTHERAPY TREATMENT USING MULTIPLEXED PROXIMITY LIGATION ASSAYS (PLA) Koong, Albert Craig, David IDENTIFICATION OF POTENTIAL VIRULENCE GENES IN FRANCISELLA TULARENSIS BY INFECTIVITY ASSAYS PERFORMED IN DROSOPHILA MELANOGASTER Schneider, David Crowell, Andrea SUBTHALAMIC NUCLEUS AND MOTOR CORTEX LOCAL FIELD POTENTIALS IN PATIENTS WITH SYSTONIA AND PARKINSON'S DISEASE Starr, Philip Downey, John NATIONAL TRENDS OF COMPLICATION RATES DURING HOSPITALIZATION IN THE US Morton, John Fredericks, Carolyn SEROTONIN TRANSPORTER SHORT ALLELE IS ASSOCIATED WITH PRO-INFLAMMATORY BIAS AT BASELINE AND AFTER PSYCHOSOCIAL STRESS Gross, James Galvez, Michael PULLULAN DELIVERY FILM FOR TARGETED ISCHEMIC PRECONDITIONING Gurtner, Geoffrey Garcia, Debra Elena TRAINING TRAINERS IN HEALTH AND HUMAN RIGHTS: IMPLEMENTING CURRICULA REFORM IN SOUTH AFRICAN HEALTH SCIENCES INSTITUTIONS Crawley, LaVera Gaster, Richard CHIPPING AWAY AT CANCER DETECTION WITH MAGNETIC NANOTECHNOLOGY Wang, Shan Gipp, Melanie OVERSEAS RESIDENCY TRAINING: TO WHAT EXTENT DO NONUNIVERSITY AFFILIATED INTERNATIONAL ROTATIONS PROVIDE TRAINING WITHIN ACGME CORE COMPETENCIES? Edler, Alice Green, Cheryl SLEEP AND THE CORTISOL AWAKENING RESPONSE IN WOMEN WITH METASTATIC OR RECURRENT BREAST CANCER Spiegel, David Green, Gary NOTCH SIGNALING MEDIATES COCHLEAR PROGENITOR CELL DIFFERENTIATION Cheng, Alan He, Lisa AMYLOID PRECURSOR PROTEIN C-TERMINAL FRAGMENTS FORM LARGER AGGREGATES AND ARE TRAFFICKED MORE SLOWLY THAN FULL-LENGTH COUNTERPARTS Mobley, William Huynh, Grace STRATEGIES FOR MANAGING THE CONSEQUENCES OF A MANUFACTURING DEFECT AND RECALL OF A DRUG PRODUCT PRODUCED IN A CONTRACT MANFUACTURING FACILITY Eaton, Margaret James, Jocelyn SECONDARY SCHOOL STUDENTS AS COMMUNITY EDUCATORS ABOUT MALARIA: ADULT AND STUDENT PERSPECTIVES FROM THE GAMBIA Blackburn, Brian Janka, David CHARACTERIZATION OF KAPOSI'S SARCOMA-ASSOCIATED IMMUNE RECONSTITUTION INFLAMMATORY SYNDROME IN SUB-SAHARAN AFRICA Martin, Jeffrey Johnson, Thomas IDENTIFICATION OF CANCER STEM CELLS AND CHARACTERIZATION OF THEIR ROLE IN CHEMOTHERAPY RESISTANCE IN OSTEOSARCOMA Sweet-Cordero, Alejandro Krampitz, Geoff ADVENTITIAL VEGF SIGNALING IS CRITICAL FOR RESTENOSIS AFTER VASCULAR INJURY Chang, Ching-Pin Lin, Patrick THE ROLE OF THE RETINOBLASTOMA/E2F1 TUMOR SUPPRESSOR PATHWAY IN THE DNA LESION RECOGNITION STEP OF NUCLEOTIDE EXCISION REPAIR Ford, James Lin, Steven STOPPING A SILENT KILLER IN THE UNDERSERVED ASIAN COMMUNITY: A NOVEL LIVER CANCER PREVENTION CLINIC Trinh, Frank Link, James IFOX PHARMACOGENOMICS: A PRACTICALITY TEST FOR A qRT-PCR FFPE TUMOR ANALYSIS METHOD Sikic, Branimir Macleod, Liam THE ROLE OF WINGLESS PROTEIN (WNT) IN SCARLESS VS SCARRING WOUND REPAIR Lorenz, Hermann Mair, Robert INTERFERON-B THERAPY IN TH1 AND TH17 MODELS OF CENTRAL NERVOUS SYSTEM AUTOIMMUNITY Steinman, Lawrence McGuire, Angela DETECTION OF NOVEL CYTOGENETIC ABNORMALITIES IN LOWGRAD B-CELL LYMPHOMAS George, Tracy Meister, David ELITE GOLF SWING BIOMECHANICS DRIVE BENCHMARKS FOR AMATEURS Ladd, Amy Min, Elise PRE-HOSPITAL CARE FOR OBSTETRIC EMERGENCIES IN INDIA Mahadevan, Swaminatha Nakao, Jolene ACCEPTANCE AND ACCESS HOME-BASED HIV COUNSELING AND TESTING AND BARRIERS TO CARE IN RURAL WESTERN KENYA Miller, N. Grant Nguyen, Phuong SYNTHETICALLY LETHAL COMPOUND INHIBITS RENAL CELL CANCER THROUGH INHIBITING ANAEROBIC METABOLISM Giaccia, Amato Odegaard, Justin PPAR-DELTA SENSES AND ORCHESTRATES THE CLEARANCE OF APOPTOTIC CELLS TO PROMOTE TOLERANCE Chawla, Ajay Ortiz-Rubio, Paulina PREVALENCE AND NATURAL HISTORY OF PEDIATRIC DELIRIUM IN THE INTENSIVE CARE SETTING Shaw, Richard Ositelu, Olufisayo COMPARING UTILIZATION PATTERNS OF PRIVATE HEALTH INSURANCE ENROLLEES WITHIN A PRIVATE HEALTH INSTITUTION IN SOUTHWESTERN NIGERIA Haberland, Corinna Peraza, Joe THE EFFECT OF GASTRIC BYPASS SURGERY ON COGNITION Morton, John Pianko, Matthew THE STUDY OF NEUROBLASTOMA FROM A STEM CELL PERSPECTIVE Clarke, Michael Plant, Ashley A PROTEOMICS STUDY: LOW MOLECULAR WEIGHT BIOMARKERS FOR GLIOBLASTOMA Cohen, Harvey Pouliot, Michael TOTAL HIP ARTHROPLASTY USING AN ANTERIOR APPROACH AND A FRACTURE TABLE: A COMMUNITY HOSPITAL EXPERIENCE Woolson, Steven Pridgen, Brian OPTICAL TRACKING FOR DEVICE DESIGN AND SURGICAL EDUCATION IN SINGLE INCISION LAPAROSCOPIC SURGERY Dutta, Sanjeev Raj, Kristin AGE ADJUSTMENT: A POOR STRATEGY FOR PREDICTING OUTCOME IN CHILDREN BORN PREMATURELY Sutcliffe, Trenna Ramachandra, Tara CORRELATION BETWEEN SYMPTOM SCORES, NASAL ENDOSCOPY AND IN-OFFICE COMPUTED TOMOGRAPHY IN CHRONIC RHINOSINUSITIS PATIENTS AFTER FUNCTIONAL ENDOSCOPIC SINUS SURGERY Hwang, Peter Robinson, Chandler EFFECT OF THE MEDIA ON AN INDIVIDUAL’S LEVEL OF CONFIDENCE IN HIS OR HER HEALTHCARE SYSTEM Budorf, Kate Rolnick, Josh INTELLECTUAL PROPERTY PROTECTIONS FOR PHARMACEUTICALS AND ACCESS TO MEDICINES IN DEVELOPING COUNTRIES: A CASE STUDY ANALYSIS IN GUATEMALA Haberland, Corinna Saber, Sepideh FLEXOR TENDON TISSUE ENGINEERING: BIOREACTOR CYCLIC STRAIN INCREASES CONSTRUCT STRENGTH Chang, James Selig, Sarah Jane SYSTEMATIC REVIEW: THE BENEFITS AND HARMS OF GARDENING Bravata, Dena Sin, Jessica 3D-FSE-CUBE FOR DETECTION OF HIP PATHOLOGY WITH MR ARTHROGRAPHY Gold, Garry Slikker, William EXPLORING TRIGGERS OF ATRIAL FIBRILLATION Wang, Paul Slikker, William REGROWING THE BRAIN: THE EFFECT OF TRANSPLANTING HUMAN NEURAL PROGENITOR CELLS AFTER STROKE Steinberg, Gary Smith, Kierann PROTEIN AND GENE PROFILES OF OSTEOPROGENITOR CELLS ON ALLOGRAFT BONE Goodman, Stuart Tenforde, Adam IDENTIFYING MODIFIABLE RISK FACTORS FOR STRESS FRACTURES IN HIGH SCHOOL FEMALE DISTANCE RUNNERS Sainani, Kristin Cobb Troke, Josh THE USE OF METFORMIN AS A CARDIOPROTECTIVE AGENT IN HEART TRANSPLANTATION DECREASES ISCHEMIA-REPERFUSION INJURY AND INCREASES GRAFT FUNCTION AND SURVIVAL Fischbein, Mike Wang, Marie RACIAL/ETHNIC DISPARITIES IN CHILD MORTALITY RATES IN CALIFORNIA, 1989-2004 Wise, Paul Wilhelm-Leen, Emilee PREFERENCE FOR TRADITIONAL BIRTH ATTENDANTS AMONG MIGRANT WOMEN IN BAJA CALIFORNIA Wise, Paul Woodard, Gavitt RNYGB ULCER OR STRICTURE COMPLICATION ASSOCIATED WITH INCREASED WEIGHT LOSS Morton, John Woodard, Gavitt GASTRIC BYPASS IMPROVES MUSCULOSKELETAL FUNCTION Morton, John Woodard, Gavitt LONG-TERM IMPROVEMENT IN CARDIAC RISK FACTORS FOLLOWING RNYGB Morton, John Woodard, Gavitt PROBIOTICS IMPROVE OUTCOMES AFTER ROUX-EN-Y GASTRIC BYPASS SURGERY: A PROSPECTIVE RANDOMIZED TRIAL Morton, John Thank you to the 2009 Symposium Committee, who helped plan the event, read all abstracts, and judged poster presentations. Dr. Laurence Baker, Dr. Patricia Cross, Chris Cueva, Alana Frost, Matt Goldstein, Gene Ma, Elise Min, Sarah Nelson, Adeoti Oshinowo, Wendy Pang, Sarah Pickard, Mara Violanti, Judy Yeh Thank you to the additional 2009 Symposium Judges, who volunteered their time and effort! Marissa Aillaud, James Berbee, Tiffany Castillo, Patricia Foo, Dr. Neil Gesundheit, Joshua Goldner, Mariko Howe, Dr. Susan Knox, Andrew Lee, Aabed Meer, Laura Prolo, Jeremiah Ray, Dr. Oscar Salvatierra, Jessica Tsai, Angela Venegas, Jane Whitney And a HUGE thank you to the Stanford University Medical Center Alumni Association for their continued, generous support of this year’s Medical Student Research Symposium. For more information about the Medical Scholars Program, please visit our website: http://medscholars.stanford.edu/ For more information about the Scholarly Concentration Program, please visit our website: http://med.stanford.edu/md/curriculum/scholarly_concentrations/ THE EVALUATION OF PRE AND POST PROCESSING SEMEN ANALYSIS PARAMETERS AT THE TIME OF INTRA-UTERINE INSEMINATION IN COUPLES DIAGNOSED WITH MALE FACTOR INFERTILITY Chioma Agbo and Michael H Dahan M.D., Department of Obstetrics & Gynecology, Stanford Reproductive Endocrinology and Infertility (REI) Center Male infertility is generally defined as an inability to conceive by the male partner that is attributable to several causes such as low sperm production, abnormal sperm morphology or poor sperm motility. Intrauterine insemination (IUI) remains a popular initial treatment option for infertile couples due to its lower costs and greater religious acceptability, especially for couples with male factor infertility. IUI involves placing processed donor sperm directly into the uterine cavity. Semen analysis is the most common method of evaluating male reproductive potential and is often performed prior to an IUI. Unfortunately, there is very limited literature available evaluating the potential semen analysis parameters in predicting pregnancy outcome, particularly in severe male infertility. In this study we performed a retrospective case-control of three hundred and eighty six couples undergoing one thousand IUI cycles in which the male partner had a semen analysis done at Stanford Reproductive Endocrinology and Infertility (REI) Center to determine whether the couple conceived with the intrauterine insemination. Statistical analysis revealed that couples with extreme male infertility, defined as 0.5 cc or less volume of semen specimen postprocessing is strongly correlated with failure to achieve pregnancy. Funding provided by the Stanford Medical Scholars Fellowship Program. TROPONIN I: TIME-TO-POSITIVITY IN EMERGENCY DEPARTMENT PATIENTS WITH ACUTE MYOCARDIAL INFARCTION Chioma Agbo and Donald Schreiber M.D., Department of Surgery – Emergency Medicine, Stanford University School of Medicine Background: The American College of Cardiology (ACC)/European Society of Cardiology (ESC) criteria for the diagnosis of acute myocardial infarction are based on a rise and fall of cardiac markers such as troponin I (TnI) and CKMB associated with clinical symptoms compatible with myocardial ischemia or infarction and specific ECG changes. Several studies have shown that serial measurements of serum cardiac troponins and/or CKMB over an 8 to 12 hour period of observation can reliably identify or exclude an AMI. Unfortunately, there is no established serial serum testing regimen recommended for exclusion of AMI using the current ACC/ESC criteria for AMI to guide physician medical decision process. Objectives: Our objective is to determine optimum serial serum testing time points for TnI after ED arrival time that can be used to rule in or rule out AMI with a high sensitivity. The aim of this study is to improve the clinical decision algorithm for patients with possible AMI in the ED. Methods: A retrospective observational study was conducted on patients presenting to a university center ED with an AMI. Patients with AMI during hospitalization or STEMI were excluded. We retrospectively determined the blood sample collection times for cardiac markers compared to time of initial ED presentation. Time to positivity of TnI was calculated using a statistical analysis software program, SAS version 9.1.3. Results: A chart review was conducted on 638 patients. 120 patients had a final diagnosis of NSTEMI. 50% were positive within 1 hour from baseline. 95% of patients were positive within 8 hrs. Conclusions: Our findings indicate that 95% of patients diagnosed with NSTEMI have a positive result within 8 hours from ED arrival to blood draw. Results from this study suggest a prospective study needs to be done to evaluate if time intervals of 0, 4 and 8 hours is suitable for serial measurements of TnI. Funding provided by the Stanford Medical Scholars Fellowship Program. THE RELATIONSHIP BETWEEN MRI AVAILABILITY AND LOW BACK PAIN CARE UTILIZATION Jacqueline Baras and Laurence Baker, Department of Health Research and Policy, Stanford University. The rapid expansion in the number of magnetic resonance imaging (MRI) scanners in the United States has enabled more patients to receive cutting-edge imaging that can produce valuable diagnostic information. However, for patients with low back pain, the use of MRI is controversial. Spinal abnormalities detected by MRI often do not correlate with symptoms and can lead to additional, unnecessary interventions, including surgery, which in many patients is of uncertain efficacy. This paper investigates the relationship between the expanding MRI supply and the diagnosis and treatment of low back pain in approximately 800,000 Medicare beneficiaries from 1998-2005, providing new information about the broader effects of increased imaging availability in a relatively large group of patients. We use logistic regression models in which the key independent variable is a measure of MRI availability (distribution of MRI units per million population); the dependent variables are indicators of receipt of low back MRI or surgery within 30, 90, 180, or 365 days of an “index visit” for low back pain; and controls include patient demographic and health characteristics as well as fixed effects for areas and years. We find that patients in areas in the highest quartile of MRI availability, compared to patients in the lowest quartile, were 15.2% more likely to receive MRI within 30 days of their index visit, and 9.6% more likely within 365 days (both p<.001). Increases in MRI availability are also associated with higher probabilities of low back surgery receipt. Diffusion of MRI equipment is associated with increased early use of low back MRI and subsequent surgery, both of which are discouraged for the majority of patients with new onset low back pain. These results raise concerns that the widespread expansion of MRI may adversely impact quality of care for low back pain patients. Policy efforts that assess the value of technology diffusion should consider both the monetary and non-monetary costs that increased MRI availability may have for particular patient groups. Funding provided by the Stanford Medical Scholars Fellowship Program. IDENTIFICATION OF PERIPHERAL AND CNS SIGNALING PROTEINS ASSOCIATED WITH ALZHEIMER’S DISEASE Sarah L. Bauer Huang, Markus Britschgi, Tony Wyss-Coray. Department of Neurology & Neurological Sciences, Stanford School of Medicine Alzheimer’s disease (AD) is a neurodegenerative disease that is clinically characterized by development of initial mild loss of episodic memory that progresses into a severe dementia with additional psychomotor symptoms at later stages of the disease. Pathophysiological hallmarks of AD include: β-amyloid (Aβ) plaques, tau-hyperphosphorylation, neurodegeneratioin, and neuroinflammation. A number of cytokines and growth factors have also been shown to be transported across the blood brain barrier in both directions (reviewed in [1]), and changes of levels of several of these factors in the brain and in the blood have been associated with AD. Signaling proteins characterized in this research, as well as in previous research in our lab [2], could be used as pre-dementia biomarkers of AD, which would have implications both in diagnosis as well as in treatment. Indeed, a set of 18 out of 120 simultaneously detected plasma signaling proteins has been recently identified to classify blinded plasma samples from patients with early AD and non-demented controls with high accuracy [2]. For this current study, we hypothesize that peripheral and CSF levels of signaling proteins are associated with AD-related psychopathological changes and molecular biomarkers. Using Luminex technology, we measured concentrations of 74 soluble intercellular signaling proteins in plasma samples of 51 AD patients and 87 healthy normal controls, as well as 45 CSF samples. Using the statistical tool SAM (Significance Analysis of Microarrays) we did multivariate and linear regression analyses to find relationships between signaling proteins and molecular biomarkers of AD (CSF levels of Tau, pTau, or Aβ42) or clinical scores. For the plasma analysis, IgE and ENA-78 were negatively correlated with clinical diagnosis. EN-RAGE was positively associated with Tau, pTau and negatively associated with the Aβ42/pTau ratio. No factors were associated with Aβ42 alone. For the CSF analysis, Fatty Acid Binding Protein (FABP) was positively associated with pTau and negatively associated with Aβ42/pTau. FABP, MMP-3, Stem Cell factor, Complement 3, TNF-RII, β-2 microglobulin, α-2 macroglobulin, IL-16, Tissue factor, VCAM and PAI-1 were all positively associated with Tau. No factors in the CSF were associated with the clinical diagnosis or pTau. In our study, a number of factors were associated with clinical diagnosis or molecular AD biomarkers. Surprisingly, those factors found to correlate to disease in plasma did not overlap with those found in the CSF, suggesting the signaling proteins associated with AD may compartmentalize to the CNS or periphery. Future studies will examine the biological role of these proteins in AD. 1. Britschgi and Wyss-Coray (2007) 2. Ray et al (2007) Funding provided by the Stanford Medical Scholars Fellowship Program A BAYESIAN NETWORK TO ASSIST MAMMOGRAPHY INTERPETATION Stephanie W. Chan, Ryan W. Woods, Ross D. Shachter, Elizabeth S. Burnside, Daniel L. Rubin. Department of Diagnostic Radiology, Department of Medical Informatics. Breast cancer is the most frequently diagnosed malignancy among American women and the second leading cause of cancer death among women of all ages. Improving mammography interpretation is critical to promote early diagnosis, the most effective means of decreasing the death rate from this disease. At the same time, there is variation in practice among mammography practitioners, and methods to improve their accuracy are needed to ensure high quality practice. One challenge that radiologists face is to evaluate whether negative biopsies in suspicious cases result from sampling error. Our goal is to develop a computer application to aid radiologists with this challenging diagnostic process. We are working with a Bayesian network previously developed to represent the probabilistic relationships among key predictor variables, which appears useful in assessing the likelihood of malignancy given the abnormalities seen on mammography. By applying a probabilistic framework to relate a negative result of pathology to the degree of suspicion of malignancy on mammography of the lesion biopsied, we calculate a probability that malignancy is present in the patient. Preliminary studies show that this probability of malignancy is increased in cases that were found by clinical follow-up to be malignant, after initial biopsies were benign. These preliminary results suggest that the Bayesian Network can be used to assist radiologists with evaluating how suspicious a lesion seen on mammography is for malignancy. This information can assist a radiologist in deciding which lesions seen on mammography should undergo biopsy. In addition, this information can assist a radiologist with deciding whether a negative biopsy is discordant with the lesion seen on mammography and may require repeat biopsies to overcome initial sampling error. Our ultimate goal is an application that can help radiologists identify those cases that are most suspicious of being discordant and that would benefit most from additional sampling to ensure cancer is not missed. Funding provided by the Stanford Medical Scholars Fellowship Program. ROLE OF MHC CLASS I MOLECULES IN THE PATHOGENESIS OF AUTOIMMUNE DIABETES Pearl Chang, Remi J. Creusot, and C. Garrison Fathman. Stanford University, Department of Medicine, Division of Immunology and Rheumatology Major histocompatibility complex (MHC) proteins have been implicated in autoimmune diseases such as type 1 diabetes (T1D) but their exact role in disease pathogenesis and progression remains unclear. Recent microarray data from Kodama et al. (Clin. Immunol. 2008) suggests tissue-specific age-dependent differences in expression of certain classical MHC class I (MHC Ia) and nonclassical nonpolymorphic MHC class Ib genes in the non-obese diabetic (NOD) mice, a T1D mouse model, compared to the disease-free congenic NOD.B10 mice that differs in one segment of the MHC gene cluster. At 4 weeks of age, around the initial onset of insulitis, there was lower expression of the MHC Ia gene H2-D1 and seven of the MHC 1b genes in the pancreatic lymph nodes (PLN) of NOD mice, but not in the peripheral blood cells (PBC) or spleen. In contrast, at 12 weeks of age, when islet destruction begins, MHC expression was lower in the PBC but not PLN or spleen. Based on these observations, we examined gene and/or protein expression by quantitative PCR or FACS, respectively, of H2-D1 and the class Ib molecules Qa1 and Qa2 in PLN and PBC of 4and 12-week-old NOD and NOD.B10 female mice. We chose to focus on Qa1 and Qa2 because of their potential roles in immune suppression (Lu et al., Immunol. Rev. 2006; Hogarth et al., J. Immunol. 1985). We found significant differences in total Qa2 gene and protein expression in NOD mice relative to age-matched NOD.B10 mice, as well as differences in Qa1 gene expression and H2-D1 protein expression. These preliminary results indicate that differences in both MHC Ia and Ib expression may play a role in T1D disease pathogenesis and suggests the possibility of certain MHC genes serving as potential biomarkers of disease susceptibility or progression. Further studies are needed to determine the exact role of these MHC molecules in the immune-mediated destruction of pancreatic islets and autoimmunity. Funding provided by the Stanford Medical Scholars Fellowship Program ONCOLOGIC AND FUNCTIONAL RESULTS OF GRADE 1 CHONDROSARCOMAS AND ENCHONDROMAS AFTER CURETTAGE AND CRYOSURGICAL TREATMENT Richard Chiu, David McCall, David G. Mohler Departments of Orthopaedic Surgery and Epidemiology, Stanford Medical School Chondrosarcomas are malignant cartilage tumors that are traditionally treated by radical resection. This procedure involves amputation or removal of the entire bone segment on which the tumor resides, which results in lifelong disability and reduced quality of life. Grade 1 chondrosarcomas are often histologically and clinically indistinguishable from benign enchondromas, and are less aggressive than chondrosarcomas of higher grades (grades 2 and 3). Given their lower metastatic potential, grade 1 chondrosarcomas can potentially be treated by curettage with cryosurgery, an intralesional procedure that has been used to treat benign tumors. Curettage with cryosurgery avoids the post-operative morbidities resulting from radical resections, but may be associated with a higher risk of recurrence due to the incomplete removal of tumor cells. This study was performed to assess the efficacy of curettage and cryosurgery in treating grade 1 chondrosarcomas and in preserving the functional performance of patients. We retrospectively reviewed the medical records of 51 patients treated by curettage and cryosurgery for grade 1 chondrosarcomas and enchondromas between 1995 and 2009 with a minimum follow-up of 12 months in clinic or by phone. Primary outcomes were tumor recurrence and functional score measured by the MSTS (Musculoskeletal Tumor Society) scoring scale. Patients were also noted for secondary outcomes of tumor site, preoperative pain, bone scan results, and radiographic signs of endosteal scalloping. A summary of results is provided in the Table below. There were 16 cases of grade 1 chondrosarcomas, 16 cases of enchondromas, and 19 cases of indistinguishable tumors (grade 1 chondrosarcoma or enchondroma), most of which were tumors of the long bones. Only 1 case of recurrence occurred out of the 51 patients. Median and mean ± SD of MSTS functional score (maximum 30) were 29 and 26.9 ± 4.7 respectively. No significant differences between categories of gender, contact mode, or diagnosis (grade 1 chondrosarcoma, enchondroma, indistinguishable) were observed for recurrence or functional score. Curettage/cryosurgery yielded a negligible recurrence rate (2%), and the functional outcomes were superior to those of radical resection (data from literature). With appropriate follow-up, curettage and cryosurgery may serve as a good alternative to radical resection as the mainstay therapy of grade 1 chondrosarcomas, as this intralesional procedure yields negligible recurrence rates but superior functional results. This study was funded by the Stanford Medical Scholars Research Fellowship. POLYMETHYLMETHACRYLATE PARTICLES INHIBIT THE EXPRESSION OF OSTEOGENIC TRANSCRIPTION FACTORS RUNX2, OSTERIX, AND DLX5 IN OSTEOPROGENITOR CELLS Richard Chiu, Kierann Smith, Gene Ma, R. Lane Smith, Stuart B. Goodman Departments of Orthopaedic Surgery and Bioengineering, Stanford Medical School Wear debris particles generated from total joint replacements have been implicated as a significant inhibitory factor of osteoprogenitor differentiation. Previously, our study has shown that particles of polymethylmethacrylate (PMMA) cement inhibit the osteogenesis of osteoprogenitors with respect to mineralization and alkaline phosphatase expression. However, whether this inhibition results from direct effects of particles on transcription factors or signaling pathways that regulate osteogenesis is unknown. Runx2, osterix, and Dlx5 are the primary transcription factors that regulate osteoblast differentiation and bone formation. β-catenin is a transcriptional activator of the canonical Wnt signaling pathway, which activates Runx2 gene transcription. Msx2 is a reciprocal antagonist of Dlx5-mediated osteogenesis. In this study, we examined the effects of PMMA particles on the expression of Runx2, osterix, Dlx5, Msx2, and βcatenin in osteoprogenitor cells. Confluent cultures of MC3T3-E1 osteoprogenitor cells (ATCC) were treated with PMMA particles (1-10 μm, Polysciences) at concentrations of 0.00, 0.15, 0.30, and 0.60% v/v on their first day of differentiation in osteogenic medium containing 50 μg/mL ascorbic acid and 100 mM β-glycerophosphate. Cells were treated with PMMA particles during the first six days of differentiation. RNA was extracted from cell samples by the TRIzol method each day throughout this six-day period, reverse transcribed into cDNA, and quantified by real time-PCR using primers for mouse Runx2, osterix, Dlx5, Msx2, and β-catenin, with normalization to 18S expression. MC3T3-E1 cells challenged with PMMA particles showed a significant dose-dependent decrease in the expression of Runx2, osterix, and Dlx5 throughout the 6-day period, and through days 1-4 for β-catenin. The expression of Msx2, a reciprocal antagonist of Dlx5mediated osteogenesis, was not significantly reduced except at the highest particle concentration (0.60% v/v) and only during days 1-4. This study has shown that PMMA particles inhibit the differentiation of osteoprogenitor cells by suppressing the expression of Runx2, osterix, Dlx5, and β -catenin. The inhibition of osteoprogenitor differentiation by implant wear debris is therefore mediated by direct inhibitory effects of particles on the expression of osteogenic transcription factors. This study was funded by the Stanford Medical Scholars Research Fellowship. POLYMETHYLMETHACRYLATE PARTICLES IMPAIR OSTEOPROGENITOR VIABILITY BY CELL NECROSIS NOT APOPTOSIS Richard Chiu, Gene Ma, Kierann Smith, R. Lane Smith, Stuart B. Goodman Departments of Orthopaedic Surgery and Bioengineering, Stanford Medical School Osteolysis in total joint replacement is mediated in part by the biologic reactions of bone cells and progenitors to implant wear debris. Recent studies have shown that particles of titanium implants induce cell death by apoptosis in rat calvarial osteoblasts, murine osteoclasts, and human mesenchymal stem cells. Previously, our study has shown that particles of polymethylmethacrylate (PMMA) cement inhibit the osteogenesis of murine osteoprogenitor cells, but the effects of these particles on the viability of these cells has not been studied. The purpose of this study was to determine whether PMMA particles impair the viability of murine osteoprogenitor cells, and whether this cell death occurs by apoptosis or necrosis. Confluent cultures of murine MC3T3-E1 osteoprogenitor cells (ATCC) were treated with PMMA particles (1-10 μm, Polysciences) at doses of 0.000, 0.038, 0.075, 0.150, 0.300, and 0.600% v/v for 72 hrs. Culture supernatant levels of lactate dehydrogenase (LDH), an intracellular enzyme released from dead cells, were measured at 24-hr intervals. Cell number was determined at similar time intervals by hemocytometer cell count with trypan blue staining. Particle effects on proliferation were assessed by incubating cells in BrdU nucleoside for 24 hrs following particle challenge for 24, 48, and 72 hrs, with subsequent spectrophotometric measurement of BrdU uptake. A flow cytometry-based TUNEL assay was performed to detect cells with fragmented DNA, a hallmark of apoptosis, in cultures challenged with particles at doses of 0.075 and 0.300% v/v for 48 and 72 hrs. Cells were observed for morphology and evidence of particle phagocytosis. MC3T3-E1 cells challenged with PMMA particles showed a significant doseand timedependent increase in LDH release, a dose-dependent decrease in cell number, and a dosedependent decrease in BrdU uptake for cells challenged with particles for ≥ 48 hrs. MC3T3-E1 cells showed evidence of particle phagocytosis, swelling, and lysis as observed under the microscope. TUNEL assay revealed no apoptotic cells in particle-treated cultures at all days and particle doses tested. This study has shown that PMMA particles induce osteoprogenitor cell death, as evidenced by the increase in LDH release and the decreases in cell number and BrdU uptake. Evidence of cell swelling and lysis, a characteristic of necrosis, and the absence of apoptotic cells as determined by the TUNEL assay, indicate that cell death occurs by necrosis rather than apoptosis. The mechanism of cell death may depend on the chemical composition of the particle involved (e.g., metal vs. polymeric, metal ion effect). Bone loss induced by wear debris particles therefore involves reduction of osteoblast numbers due to cytotoxic effects on osteoprogenitor cells. This study was funded by the Stanford Medical Scholars Research Fellowship. Longitudinal investigation of cancer biomarker expression levels preand postchemoradiotherapy treatment using multiplexed proximity ligation assays (PLA). Carlene Chun, Jacob Zahn, Devin Schellenberg, Jeff Kim, Dan Chang, Albert Koong 1 Stanford University School of Medicine, Stanford, California; 2 Department of Radiation Oncology; Stanford University, Stanford, California Background: Pancreatic cancer is the 4 leading cause of death in the United States with an overall 5-year survival of less than 5%. Although there have been significant improvements in the overall survival rates for many cancers in the past 25 years, there has been little progress for pancreatic cancer. In a prospective Phase II study, we investigated the efficacy of integrating stereotactic body radiotherapy (SBRT) with gemcitabine chemotherapy. Our primary endpoint was overall survival and local progression-free survival. In addition, we analyzed a panel of 21 biomarkers from the plasma of these patients before and after SBRT to determine if there were any biomarkers that were predictive of response to therapy or overall survival. Methods: We analyzed the expression levels of 21 cancer biomarkers via multiplexed proximity ligation assays (PLA) in 32 pancreatic cancer patients and 19 age-matched controls. These patient samples were assessed for these biomarkers prior to initiating therapy. In a subset of patients, we also compared changes in this biomarker profile with the goal of identifying a plasma biomarker profile predictive of outcome or response to treatment. Results: In the clinical trial were treated with SBRT and a median of 5 cycles of gemcitabine chemotherapy resulted in a median survival of 11.8 months, a 1 year survival of 50% and a local control rate of 94%. Results of biomarker studies corroborate prior studies showing significant differences in biomarker expression levels between controls and patients prior to treatment. Three biomarkers, EpCAM, MESO, and CA125 were significantly predictive of pancreatic patient survival. In addition, decreasing levels of EpCAM after therapy was an excellent predictor of patient survival. Future work will use a larger patient pool to verify these changes in biomarker profile before and after chemoradiotherapy treatment. Conclusions: This study demonstrated that SBRT and gemcitabine chemotherapy was a promising treatment strategy. Furthermore, PLA was able to identify several prognostic markers for this disease and may be used in the future to select the patients that would be most appropriate for this therapy.