Dr. Edith Ho joined Stanford University in 2020, where she currently holds the position of Clinical Associate Professor of Medicine in the Division of Gastroenterology and Hepatology and Director of the Inflammatory Bowel Disease Program at Palo Alto VA Medical Center. She specializes in the diagnosis and treatment of inflammatory bowel disease and also practices general gastroenterology. Previously, she joined faculty at Case Western Reserve School of Medicine as Assistant Professor of Medicine. She served as a gastroenterologist at the Cleveland Veterans Affairs Medical Center, where she was Director of the Inflammatory Bowel Disease Program. She was also the Co-Director of the Fecal Microbiota Transplantation Program, where she was lauded as the pioneer of the first fecal transplant program in the U.S. veterans affairs healthcare system nationwide.

Dr. Ho is a Diplomate of the American Board of Internal Medicine (ABIM) and the American Board of Gastroenterology, a Fellow of the American College of Gastroenterology (FACG), and a Fellow of the American Gastroenterological Association (AGAF). She serves on the natonal American College of Gastroenterology Research Committee and Educational Affairs Committee where she has chaired several abstract committees, directed regional post-graduate courses, and developed CME content for the American Journal of Gastroenterology. She also served on the American Gastroenterological Association Institute Clinical Guidelines Committee as a guideline author for medical therapy for moderate to severe Crohn's Disease.

Clinical Focus

  • Gastroenterology
  • Inflammatory Bowel Disease
  • Ulcerative colitis
  • Crohn's Disease
  • Pouchitis

Academic Appointments

Administrative Appointments

  • Clinical Associate Professor of Medicine, Stanford University (2020 - Present)
  • Director, Inflammatory Bowel Disease Program, Palo Alto Veterans Affairs Medical Center (2024 - Present)

Honors & Awards

  • Franklin G. Ebaugh Jr. Resident Research Award, Stanford University Hospital and Clinics
  • Gordeon Cressy Award for Outstanding Leadership, University of Toronto, Canada
  • Honorary Clinical Associate, University of Hong Kong, Department of Gastroenterology and Hepatology
  • International Health Research Scholarship, University of Toronto, Canada
  • Ontario Medical Association Leadership Award, Medical Association in the Province of Ontario, Canada
  • Outstanding Poster Presentation Award, American College of Gastroenterology Annual Scientific Meeting
  • Research Initiative Program Grant, U.S. Veterans Integrated Service Network (VISN 10)
  • Research Travel Grant, Asian-Pacific Association for the Study of the Liver (APASL)
  • Travel Grant, American Association of Study of Liver Disease (AASLD)
  • Undergraduate Research Grant, Stanford University

Boards, Advisory Committees, Professional Organizations

  • Fellow, American Gastroenterological Association (AGAF) (2021 - Present)
  • Member, National Research Committee, American College of Gastroenterology (ACG) (2021 - Present)
  • Chair, Inflammatory Bowel Disease Section of Annual Meeting Planning Committee, American College of Gastroenterology (ACG) (2021 - 2022)
  • Faculty Member, Faculty Opinions (2020 - Present)
  • Chair, Inflammatory Bowel Disease Abstract Selection Committee, American College of Gastroenterology (ACG) (2020 - 2020)
  • Member, Guidelines Author Panel, American Gastroenterological Association (AGA) (2019 - 2021)
  • Fellow, American College of Gastroenterology (FACG) (2017 - Present)
  • Faculty Member, Faculty of 1000 Prime Peer Review (2017 - 2020)
  • Member, Educational Affairs Committee, American College of Gastroenterology (ACG) (2014 - Present)
  • Fellow and Physician Advisor, Doximity (2013 - 2018)
  • Member, American Gastroenterological Association (AGA) (2011 - 2021)
  • Member, American College of Gastroenterology (ACG) (2011 - 2017)
  • Resident Advisor, New England Journal of Medicine (NEJM) (2008 - 2008)

Professional Education

  • Board Certification: American Board of Internal Medicine, Gastroenterology (2013)
  • Fellowship: UCSF Gastroenterology Fellowship (2013) CA
  • Board Certification: American Board of Internal Medicine, Internal Medicine (2010)
  • Residency: Stanford University Internal Medicine Residency (2010) CA
  • Internship: Stanford University Internal Medicine Residency (2008) CA
  • Medical Education: University of Toronto MD Program (2007) Canada

Current Research and Scholarly Interests

Dr. Ho plays an active role in the American College of Gastroenterology (ACG) Educational Affairs committee, where she chairs several abstract committees, directs regional post-graduate courses, regularly reviews physician course content, and develops CME content for the American Journal of Gastroenterology. She is also involed in the ACG Research Committee, which plays a criticol role in setting the direction of scientific advancement, education, and distribution of grant funding. Dr. Ho has also served as a guideline author for the American Gastroenterological Association on endoscopic therapies for weight loss and the medical management of luminal and perianal Crohn's disease. These guidelines shed new knowledge and set new standards of care for clinical practice here and abroad.

All Publications

  • Prevalence Rates of Pneumococcal Vaccination in IBD and 30-Day Clinical Outcomes in Patients With IBD and Pneumococcal Disease Stratified by Receipt of Pneumococcal Vaccination: A Multi-Network Study. Crohn's & colitis 360 Ford, A., Chittajallu, V., Abraham Perez, J., Martin, S., Alkhayyat, M., Dave, M., Ho, E. Y., Sinh, P., Nguyen, V., Cooper, G., Katz, J., Cominelli, F., Regueiro, M., Mansoor, E. 2023; 5 (4): otad048

    View details for DOI 10.1093/crocol/otad048

    View details for PubMedID 38077746

    View details for PubMedCentralID PMC10708920

  • Continuing Medical Education Questions: August 2021. The American journal of gastroenterology Ho, E. Y. 2021; 116 (8): 1585


    Article Title: A microsimulation model to determine the cost-effectiveness of treat to target strategies for Crohn's disease.

    View details for DOI 10.14309/ajg.0000000000001372

    View details for PubMedID 34587125

  • AGA Clinical Practice Guidelines on the Medical Management ofModerate to Severe Luminal and Perianal Fistulizing Crohn'sDisease. Gastroenterology Feuerstein, J. D., Ho, E. Y., Shmidt, E., Singh, H., Falck-Ytter, Y., Sultan, S., Terdiman, J. P., American Gastroenterological Association Institute Clinical Guidelines Committee, Sultan, S., Cohen, B. L., Chachu, K., Day, L., Davitkov, P., Lebwohl, B., Levin, T. R., Patel, A., Peery, A. F., Shah, R., Singh, H., Singh, S., Spechler, S. J., Staller, K., Thrift, A. P., Weiss, J. M. 2021; 160 (7): 2496-2508

    View details for DOI 10.1053/j.gastro.2021.04.022

    View details for PubMedID 34051983

  • Providing the Best Care for Patients With Crohn's Disease: An Examination of the New AGA Clinical Practice Guidelines on the Medical Management of Moderate to Severe Luminal and Perianal Fistulizing Crohn's Disease. Gastroenterology Ho, E. Y., Singh, S., Terdiman, J. P. 2021; 160 (7): 2557-2562

    View details for DOI 10.1053/j.gastro.2021.04.024

    View details for PubMedID 34051986

  • Spotlight: Medical Management of Moderate to Severe Luminal and Perianal Fistulizing Crohn's Disease. Gastroenterology Shmidt, E., Ho, E. Y., Feuerstein, J. D., Singh, S., Terdiman, J. P. 2021; 160 (7): 2511

    View details for DOI 10.1053/j.gastro.2021.04.028

    View details for PubMedID 34057068

  • AGA Clinical Practice Guidelines on Intragastric Balloons in the Management of Obesity. Gastroenterology Muniraj, T., Day, L. W., Teigen, L. M., Ho, E. Y., Sultan, S., Davitkov, P., Shah, R., Murad, M. H. 2021; 160 (5): 1799–1808

    View details for DOI 10.1053/j.gastro.2021.03.003

    View details for PubMedID 33832655

  • Continuing Medical Education Questions: June 2020. The American journal of gastroenterology Ho, E. Y. 2020; 115 (6): 812


    Article Title: Effect of Lifestyle Factors on Outcomes in Patients with Inflammatory Bowel Diseases.

    View details for DOI 10.14309/ajg.0000000000000708

    View details for PubMedID 32496318

  • Opportunistic Infections Are More Prevalent in Crohn's Disease and Ulcerative Colitis: A Large Population-Based Study INFLAMMATORY BOWEL DISEASES Sheriff, M., Mansoor, E., Luther, J., Ananthakrishnan, A. N., Abou Saleh, M., Ho, E., Briggs, F. S., Dave, M. 2020; 26 (2): 291–300


    Opportunistic infections (OIs) are more common in patients with inflammatory bowel disease (IBD); however, there have been limited large-scale studies of OIs in IBD. We investigated the epidemiological characteristics of OI in Crohn's disease (CD) and ulcerative colitis (UC) using a large population-based database.Data were collected from a commercial database (Explorys Inc., Cleveland, OH, USA) that provided electronic health records from 26 major integrated US health care systems from 1999 to March 2018. In this data set, we identified all CD and UC patients, based on Systemized Nomenclature of Medicine-Clinical Terms. Within these cohorts, we identified a variety of OIs and compared the prevalence rate of OI in individuals with IBD with that of controls (patients in the database between March 2013 and March 2018 without the diagnosis of IBD).Explorys included 153,290 patients with CD and 128,540 patients with UC between March 2013 and March 2018. The prevalence of OIs was 17.8% in CD, 19.2% in UC, and 7% in non-IBD controls. When compared with non-IBD controls, all OIs were more common in CD (prevalence ratio [PR], 2.54; 95% confidence interval [CI], 2.51-2.57) and UC (PR, 2.74; 95% CI, 2.71-2.77). Overall, viral infections were numerically more common, whereas bacterial infections had the highest PRs in CD and UC when compared with controls without IBD.We found significantly higher rates of OI in IBD. Our study suggests the need for close follow-up of IBD patients to diagnose and provide vaccinations where applicable for prevention of infections.

    View details for DOI 10.1093/ibd/izz147

    View details for Web of Science ID 000506807300024

    View details for PubMedID 31314891

  • Inflammatory Bowel Disease Patients Prior to Starting on Anti-TNF Are Over 5 Times More Likely to Be Screened for Hepatitis B Infection Compared to Those Starting High Dose Corticosteroids Ho, E. Y., Marshall, V., Alsamman, Y., Chung, G., Burant, C., Dave, M., Falck-Ytter, Y. LIPPINCOTT WILLIAMS & WILKINS. 2019: S447
  • Continuing Medical Education Questions: April 2019. The American journal of gastroenterology Ho, E. Y. 2019; 114 (4): 552


    To receive CME/MOC credit for this activity, please go to: Title: Diagnosis and Treatment of Rumination Syndrome: A Critical Review.

    View details for DOI 10.14309/ajg.0000000000000213

    View details for PubMedID 30950858

  • Continuing Medical Education Questions: September 2019. The American journal of gastroenterology Ho, E. Y. 2019; 114 (9): 1417


    Article Title: Inflammatory Bowel Disease: A Practical Path to Transitioning from Pediatric to Adult Care.

    View details for DOI 10.14309/ajg.0000000000000382

    View details for PubMedID 31490225

  • Continuing Medical Education Questions: June 2018. The American journal of gastroenterology Ho, E. Y. 2018; 113 (6): 802

    View details for DOI 10.1038/s41395-018-0130-8

    View details for PubMedID 29941935

  • Hepatitis B Virus Screening and Reactivation in a National VA Cohort of Patients with Inflammatory Bowel Disease Treated with Tumor Necrosis Factor Antagonists. Digestive diseases and sciences Shah, R. n., Ho, E. Y., Kramer, J. R., Richardson, P. n., Sansgiry, S. n., El-Serag, H. B., Hou, J. K. 2018; 63 (6): 1551–57


    Practice guidelines recommend screening for hepatitis B virus (HBV) infection prior to initiating treatment of inflammatory bowel disease (IBD) with anti-tumor necrosis factor (anti-TNF) therapy. However, the adherence to these screening guidelines and the clinical outcomes of HBV reactivation following anti-TNF use are not well known.This is a retrospective cohort study using the Veterans Health Administration datasets for IBD patients with filled prescriptions for anti-TNFs from 2003 to 2011. Laboratory testing was used to define HBV screening status in the 12 months preceding anti-TNF initiation. Logistic regression models were used to identify predictors of HBV screening. Cases of potential HBV reactivation were identified using ICD-9 codes for HBV infection or acute liver failure or by medications used for HBV infection treatment, and manually reviewed for verification.We identified 3357 IBD patients with filled prescriptions for anti-TNF medications. The HBV testing prior to anti-TNF initiation was 8.1% in 2003 and increased to 43.2% by 2011, with an overall rate of 23.7%. In multivariate analysis, African-American race, facilities with a higher volume of IBD patients, and facilities with an academic affiliation were associated with a higher probability of HBV screening. We did not identify a single case of confirmed clinically relevant HBV reactivation after anti-TNF initiation during 7210 patient-years of medication use.HBV screening rates prior to anti-TNF initiation are low among IBD patients, but have increased over time. Despite low rates of screening, clinically significant HBV reactivation after anti-TNF initiation in this US cohort was nonexistent.

    View details for DOI 10.1007/s10620-018-5042-3

    View details for PubMedID 29663266

  • Continuing Medical Education Questions: October 2018. The American journal of gastroenterology Ho, E. Y. 2018; 113 (10): 1430

    View details for DOI 10.1038/s41395-018-0280-8

    View details for PubMedID 30356159

  • Continuing Medical Education Questions: January 2018: Prophylactic Therapy of Cyclic Vomiting Syndrome in Children: Comparison of Amitriptyline and Cyproheptadine: A Randomized Clinical Trial. The American journal of gastroenterology Ho, E. Y. 2018; 113 (1): 141

    View details for DOI 10.1038/ajg.2017.490

    View details for PubMedID 29311736

  • Differences in Drug Treatment Practices Among Younger and Older Veterans With Inflammatory Bowel Disease Ho, E. Y., Marshall, V. J., Alsamman, Y., Chung, G., Burant, C. J., Dave, M., Falck-Ytter, Y. T. NATURE PUBLISHING GROUP. 2017: S407
  • IgM Nephropathy After Treatment with Oral 5-Aminosalicylic Acid Derivatives in a Young Patient with Ulcerative Colitis Ho, E. LIPPINCOTT WILLIAMS & WILKINS. 2017: S57
  • Fear of Failure: Engaging Patients in Antimicrobial Stewardship after Fecal Transplantation for Recurrent Clostridium difficile Infection. Infection control and hospital epidemiology Hecker, M. T., Ho, E. n., Donskey, C. J. 2017; 38 (1): 127–29

    View details for DOI 10.1017/ice.2016.236

    View details for PubMedID 27766987

  • Continuing Medical Education Questions: September 2017: Fecal Incontinence Is Associated With Mortality Among Older Adults With Complex Needs: An Observational Cohort Study. The American journal of gastroenterology Ho, E. Y. 2017; 112 (9): 1438

    View details for DOI 10.1038/ajg.2017.274

    View details for PubMedID 28874872

  • Continuing Medical Education Questions: April 2017. The American journal of gastroenterology Ho, E. Y. 2017; 112 (5): 703

    View details for DOI 10.1038/ajg.2017.113

    View details for PubMedID 28469234

  • Nivolumab-associated nausea and vomiting as an immune adverse event. European journal of cancer (Oxford, England : 1990) Shi, Y. n., Lin, P. n., Ho, E. Y., Nock, C. J. 2017; 84: 367–69

    View details for DOI 10.1016/j.ejca.2017.07.029

    View details for PubMedID 28827043

  • Continuing Medical Education Questions: April 2016. The American journal of gastroenterology Ho, E. Y. 2016; 111 (4): 492

    View details for DOI 10.1038/ajg.2016.91

    View details for PubMedID 27125712

  • Fecal Microbiota Transplantation by Freeze-Dried Oral Capsules for Recurrent Clostridium difficile Infection. Open forum infectious diseases Hecker, M. T., Obrenovich, M. E., Cadnum, J. L., Jencson, A. L., Jain, A. K., Ho, E. n., Donskey, C. J. 2016; 3 (2): ofw091

    View details for DOI 10.1093/ofid/ofw091

    View details for PubMedID 27822485

    View details for PubMedCentralID PMC5095935

  • Ulcerative Colitis: What is the Optimal Treatment Goal and How Do We Achieve It? Current treatment options in gastroenterology Ho, E. Y., Cominelli, F. n., Katz, J. n. 2015; 13 (1): 130–42


    The treatment paradigms and therapeutic options for ulcerative colitis (UC) have rapidly evolved during the past decade. Traditionally, the treatment target has focused on achieving successful induction and maintenance of steroid-free clinical remission. This has been shown to provide a better quality of life and a reduction in complications, hospitalizations, and surgery. Recent studies, however, suggest that achieving "mucosal healing" or endoscopic remission may be the optimal treatment endpoint. In this review, we will examine the treatment goals for UC and the efficacy of each therapy to reach these targets. We will also review the therapeutic options available for UC: mesalamines, steroids, immunomodulators, and biologics, including the first anti-integrin inhibitor, approved in May 2014, for the treatment of UC. Therapeutic drug monitoring, which measures serum drug level and anti-drug antibody concentrations, is emerging as an important clinical decision tool in patients on tumor necrosis factor (TNF)-antagonists. These evolving treatment strategies allow gastroenterologists to optimize control of the disease and offer patients a better quality of life.

    View details for DOI 10.1007/s11938-014-0044-5

    View details for PubMedID 25619458

  • Preemptive adefovir versus lamivudine for prevention of hepatitis B reactivation in chronic hepatitis B patients undergoing chemotherapy. Hepatology international Ho, E. Y., Yau, T. n., Rousseau, F. n., Heathcote, E. J., Lau, G. K. 2015; 9 (2): 224–30


    This proof-of-concept study compared lamivudine (LAM) with a newer antiviral agent, adefovir dipivoxil (ADF), in preventing hepatitis B virus (HBV) reactivation in chronic HBV patients undergoing chemotherapy.Hepatitis B surface antigen (HBsAg) positive patients intended to undergo chemotherapy were randomized to receive either LAM 100 mg daily or ADF 10 mg daily. Anti-viral therapy was started 1 week prior to chemotherapy and until 6 months after completing chemotherapy. The primary outcome was HBV reactivation rate. All patients with viral breakthrough were screened for resistance mutations by direct sequencing.Seventy treatment-naïve patients were consecutively randomized 1:1 to LAM or ADF. The median baseline HBV DNA levels were similar (LAM 3.36 vs. ADF 3.17 log10 copies/mL, p = 0.860). The median duration was 8.3 months on LAM and 10.6 months on ADF (p = 0.220). HBV reactivation was observed in 13/35 (37.1%) on LAM compared with 10/35 (28.6%) on ADF (p = 0.611). The median time to HBV reactivation was 4.6 and 8.1 months, on LAM and ADF respectively. Among these 13 patients, 8/13 (61.5%) on LAM had developed drug resistance mutations but none on ADF had developed drug resistance mutations to ADF (p = 0.003). Both drugs were well tolerated and no severe drug-related toxicities were reported.In this randomized clinical study, adefovir and lamivudine demonstrated similar efficacy in preventing hepatitis B reactivation in HBsAg-positive patients undergoing chemotherapy. In patients whose hepatitis B reactivated, adefovir was associated with a lower resistance profile.

    View details for DOI 10.1007/s12072-015-9612-6

    View details for PubMedID 25788197

  • Expanded use of aggressive therapies improves survival in early and intermediate hepatocellular carcinoma HPB Ho, E. Y., Cozen, M. L., Shen, H., Lerrigo, R., Trimble, E., Ryan, J. C., Corvera, C. U., Monto, A. 2014; 16 (8): 758-767


    Despite the increasing annual incidence of hepatocellular carcinoma (HCC) in the USA, now estimated at 2.7 cases per 100 000 population, only a small proportion of patients receive treatment and 5-year survival rates range from 9% to 17%.The present study examines the effects of multimodal treatment on survival in a mixed-stage HCC cohort, focusing on the impact of radical therapy in patients with Barcelona Clinic Liver Cancer (BCLC) stage B disease.A retrospective review of the medical records of 254 patients considered for HCC treatment between 2003 and 2011 at a large tertiary referral centre was conducted.A total of 195 (76.8%) patients were treated with a median of two liver-directed interventions. Median survival time was 16 months. In proportional hazards analysis, radiofrequency ablation (RFA) and resection were associated with significantly improved 1- and 5-year survival among patients with BCLC stage 0-A disease. In patients with BCLC stage B disease, RFA conferred a survival benefit at 1 year and resection was associated with significantly improved survival at 5 years.As one of few studies to track the complete course of sequential HCC therapies, the findings of the present study suggest that HCC patients with intermediate-stage (BCLC stage B) disease may benefit from aggressive interventions not currently included in societal guidelines.

    View details for DOI 10.1111/hpb.12214

    View details for Web of Science ID 000339665600010

    View details for PubMedID 24467780

    View details for PubMedCentralID PMC4113259

  • Functional abdominal pain causing Scurvy, Pellagra, and Hypovitaminosis A. F1000Research Ho, E. Y., Mathy, C. n. 2014; 3: 35


    Severe vitamin deficiency disease is rarely seen in developed countries. We present an atypical case of a young man with scurvy, pellagra, and hypovitaminosis A, caused by longstanding functional abdominal pain that severely limited his ability to eat.

    View details for DOI 10.12688/f1000research.3-35.v1

    View details for PubMedID 24715978

    View details for PubMedCentralID PMC3976101

  • A 13 year-old boy with post-transplantation lymphoproliferative disorder presenting with obscure gastrointestinal bleeding: a case report. F1000Research Ho, E. Y., George, V. n., McCracken, M. n., Ostroff, J. W. 2014; 3: 88


    One well recognized and potentially serious complication of chronic immunosuppression in organ transplant recipients is post-transplantation lymphoproliferative disorders (PTLD). This accounts for 20% of all malignancies in transplant recipients, which is four times higher than the general population (1,2). The diagnosis of PTLD is often difficult, due to various manifestations resulting in late diagnosis. We report an unusual presentation of PTLD in a pediatric patient where the diagnosis was achieved only after extensive investigation.

    View details for DOI 10.12688/f1000research.3252.1

    View details for PubMedID 25254098

    View details for PubMedCentralID PMC4168743

  • Prospective study of risk factors for hepatitis C virus acquisition by Caucasian, Hispanic, and Asian American patients JOURNAL OF VIRAL HEPATITIS Ho, E. Y., Ha, N. B., Ahmed, A., Ayoub, W., Daugherty, T., Garcia, G., Cooper, A., Keeffe, E. B., Nguyen, M. H. 2012; 19 (2): E105-E111


    Commonly known risk factors for infection with hepatitis C virus (HCV) include blood transfusion, injection drug use, intranasal cocaine use, and body tattoos. We hypothesized that Asian Americans infected with HCV may not identify with these established risk factors present in Caucasians and Hispanics, and our aim was to conduct a survey of risk factors in HCV-infected patients in these ethnic groups. In this prospective study, 494 patients infected with HCV completed a detailed risk assessment questionnaire at a liver centre in Northern California from 2001 to 2008. Among subjects participating in this study, 55% identified themselves as Caucasian, 20% as Hispanic, and 25% as Asian. Asian Americans were older, less likely to smoke or consume alcohol, and have a family history of cancer compared with Caucasians and Hispanics. The laboratory profiles were similar, and genotype 1 was the most common infection in all groups (74-75%). The great majority of Caucasians (94%) and Hispanics (86%) identified with commonly known risk factors, which was in contrast to 67% of Asians (P < 0.0001). The most common risk factors in Asians were blood transfusions (50%) and acupuncture (50%). Furthermore, 74% of Caucasians and 66% of Hispanics identified more than one major risk factor, while only 20% of Asians reported having more than one risk factor (P < 0.0001). Survey for established risk factors for acquisition of HCV may be more appropriate for risk assessment of Caucasians and Hispanics, but not for Asian Americans. These findings may guide the development of HCV screening in our increasingly diverse population.

    View details for DOI 10.1111/j.1365-2893.2011.01513.x

    View details for Web of Science ID 000299097400014

    View details for PubMedID 22239506

  • Epidemiology of Hepatitis A Virus and Hepatitis B Virus Infection in the United States. Year in Hepatitis Vaccinations. Ho, E. Y., Cheung, R. 2009; 3
  • Community and Population Health. The Toronto Notes 2007: Comprehensive Medical Reference. Ho, E. Y., Lee, S. Toronto Notes for Medical Students, Inc.. 2007; 23rd ed.
  • Cultural Barriers to Initiating Insulin Therapy in Chinese Individuals with Type 2 Diabetes Living in Canada. Canadian Journal of Diabetes Ho, E. Y., James, J. 2006; 30 (3): 390-396
  • Lymphatic System and Lymph Nodes Exam. Essentials of Clinical Examination Handbook. Ho, E. Y., Young, K. The Medical Society, University of Toronto, Canada. 2006; 5th ed.: 115–122
  • HIV/AIDS-Related Knowledge, Attitudes, and Practices of a Rural Community in Kep, Kingdom of Cambodia. University of Toronto Medical Journal Ho, E. Y., Grewal, S. 2005; 82 (2): 82-87
  • Estimating DNA repair by sequential evaluation of head and neck tumor radiation sensitivity using the comet assay 5th International Conference on Head and Neck Cancer of the International-Society-of-Head-Neck-Cancer Terris, D. J., Ho, E. Y., Ibrahim, H. Z., Dorie, M. J., Kovacs, M. S., Le, Q. T., Koong, A. C., Pinto, H. A., Brown, J. M. AMER MEDICAL ASSOC. 2002: 698–702


    The alkaline comet assay is a microelectrophoretic technique for detecting single-strand DNA breaks, and may be used as an indirect measure of hypoxia by determining the radiation sensitivity of individual cells.To assess the ability of the comet assay to estimate the rate of DNA repair after irradiation in patients with head and neck cancer.The comet assay was used to evaluate DNA damage in fine-needle aspirates of lymph nodes containing metastatic squamous cell carcinoma in patients with head and neck cancer 1, 2, and 3 minutes after treatment with 500 rad (5 Gy) of irradiation. The amount of DNA damage (measured as the "tail moment" of the comet) is proportional to the number of DNA single-strand breaks after irradiation, which in turn depends on the oxygen concentration in each cell.The mean +/- SD of the median tail moment of the 1-minute postirradiation comets was 29.4 +/- 14.2 (n = 27). After 2 minutes, the mean median tail moment decreased to 25.4 +/- 13.6 (n = 25), representing a mean decrease of 11.9% in those patients with both 1- and 2-minute comet assays. Assuming a linear rate of repair, this decrease in DNA damage corresponds to a repair half-life of 4.2 minutes. A 3-minute assay was also performed on samples from a smaller number of patients (n = 9), with a mean value not significantly different from that of the 2-minute assay of the samples from this group.The comet assay is a promising tool for evaluating radiation sensitivity in individual cells. The rate of DNA repair early after irradiation is consistent with data in the literature.

    View details for Web of Science ID 000176264300013

    View details for PubMedID 12049567