Bio

Current Role at Stanford


In my role as Biomedical Data Management Solutions Lead I oversee a team of talented software engineers and application specialists who enable clinical research and discovery at Stanford. As a part of Technology and Digital Solutions, our larger Research IT team works both with the Stanford School of Medicine, Stanford Children's Hospital, and Stanford Hospital and Clinics to design, build, and support critical research applications and tools. I provide consultations with faculty to discuss research plans and provide insight for applying technology to data collection, monitoring, and participant reported measures.

Publications

All Publications


  • Large-Scale Assessment of a Smartwatch to Identify Atrial Fibrillation. The New England journal of medicine Perez, M. V., Mahaffey, K. W., Hedlin, H., Rumsfeld, J. S., Garcia, A., Ferris, T., Balasubramanian, V., Russo, A. M., Rajmane, A., Cheung, L., Hung, G., Lee, J., Kowey, P., Talati, N., Nag, D., Gummidipundi, S. E., Beatty, A., Hills, M. T., Desai, S., Granger, C. B., Desai, M., Turakhia, M. P., Apple Heart Study Investigators, Perez, M. V., Turakhia, M. P., Lhamo, K., Smith, S., Berdichesky, M., Sharma, B., Mahaffey, K., Parizo, J., Olivier, C., Nguyen, M., Tallapalli, S., Kaur, R., Gardner, R., Hung, G., Mitchell, D., Olson, G., Datta, S., Gerenrot, D., Wang, X., McCoy, P., Satpathy, B., Jacobsen, H., Makovey, D., Martin, A., Perino, A., O'Brien, C., Gupta, A., Toruno, C., Waydo, S., Brouse, C., Dorfman, D., Stein, J., Huang, J., Patel, M., Fleischer, S., Doll, E., O'Reilly, M., Dedoshka, K., Chou, M., Daniel, H., Crowley, M., Martin, C., Kirby, T., Brumand, M., McCrystale, K., Haggerty, M., Newberger, J., Keen, D., Antall, P., Holbrook, K., Braly, A., Noone, G., Leathers, B., Montrose, A., Kosowsky, J., Lewis, D., Finkelmeier, J. R., Bemis, K., Mahaffey, K. W., Desai, M., Talati, N., Nag, D., Rajmane, A., Desai, S., Caldbeck, D., Cheung, L., Granger, C., Rumsfeld, J., Kowey, P. R., Hills, M. T., Russo, A., Rockhold, F., Albert, C., Alonso, A., Wruck, L., Friday, K., Wheeler, M., Brodt, C., Park, S., Rogers, A., Jones, R., Ouyang, D., Chang, L., Yen, A., Dong, J., Mamic, P., Cheng, P., Shah, R., Lorvidhaya, P. 2019; 381 (20): 1909?17

    Abstract

    BACKGROUND: Optical sensors on wearable devices can detect irregular pulses. The ability of a smartwatch application (app) to identify atrial fibrillation during typical use is unknown.METHODS: Participants without atrial fibrillation (as reported by the participants themselves) used a smartphone (Apple iPhone) app to consent to monitoring. If a smartwatch-based irregular pulse notification algorithm identified possible atrial fibrillation, a telemedicine visit was initiated and an electrocardiography (ECG) patch was mailed to the participant, to be worn for up to 7 days. Surveys were administered 90 days after notification of the irregular pulse and at the end of the study. The main objectives were to estimate the proportion of notified participants with atrial fibrillation shown on an ECG patch and the positive predictive value of irregular pulse intervals with a targeted confidence interval width of 0.10.RESULTS: We recruited 419,297 participants over 8 months. Over a median of 117 days of monitoring, 2161 participants (0.52%) received notifications of irregular pulse. Among the 450 participants who returned ECG patches containing data that could be analyzed - which had been applied, on average, 13 days after notification - atrial fibrillation was present in 34% (97.5% confidence interval [CI], 29 to 39) overall and in 35% (97.5% CI, 27 to 43) of participants 65 years of age or older. Among participants who were notified of an irregular pulse, the positive predictive value was 0.84 (95% CI, 0.76 to 0.92) for observing atrial fibrillation on the ECG simultaneously with a subsequent irregular pulse notification and 0.71 (97.5% CI, 0.69 to 0.74) for observing atrial fibrillation on the ECG simultaneously with a subsequent irregular tachogram. Of 1376 notified participants who returned a 90-day survey, 57% contacted health care providers outside the study. There were no reports of serious app-related adverse events.CONCLUSIONS: The probability of receiving an irregular pulse notification was low. Among participants who received notification of an irregular pulse, 34% had atrial fibrillation on subsequent ECG patch readings and 84% of notifications were concordant with atrial fibrillation. This siteless (no on-site visits were required for the participants), pragmatic study design provides a foundation for large-scale pragmatic studies in which outcomes or adherence can be reliably assessed with user-owned devices. (Funded by Apple; Apple Heart Study ClinicalTrials.gov number, NCT03335800.).

    View details for DOI 10.1056/NEJMoa1901183

    View details for PubMedID 31722151

  • Text Message Intervention (TEACH) Improves Quality of Life and Patient Activation in Celiac Disease: A Randomized Clinical Trial. journal of pediatrics Haas, K., Martin, A., Park, K. T. 2017

    Abstract

    To determine the impact of the Text Message Educational Automated Compliance Help (TEACH) text message intervention as a pragmatic approach for patient engagement among adolescents with celiac disease (CD) as measured by gluten-free diet (GFD) adherence, patient activation, and quality of life (QOL).Randomized controlled trial with patient recruitment at a pediatric, university-based hospital and through social media; 61 participants ages 12-24 years with CD diagnosed at least 1 year were enrolled. The TEACH intervention cohort received 45 unique text messages over a 3-month study period while the control group received standard of care treatment. Primary outcome measures included objective markers of GFD adherence included serum tissue transglutaminase IgA and deamidated gliadin peptide IgA levels. Secondary patient-reported outcomes collected via online survey included the Celiac Dietary Adherence Test, National Institutes of Health (NIH) Patient-Reported Outcomes Measurement Information System (PROMIS) Global Short Form measure of QOL, Celiac Symptom Index, and Patient Activation Measure. All measures were assessed at enrollment and after the 3-month study period. Statistical analysis performed using the 2-tailed paired Student t test.Among the TEACH intervention group, there was significant improvement comparing enrollment scores with 3-month follow-up scores in patient activation (Patient Activation Measure score 63.1 vs 72.5, P?=?.01) and QOL (NIH PROMIS Global Mental Health 50.8 vs 53.3, P?=?.01 and NIH PROMIS Global Physical Health 50.8 vs 57.7, P?=?.03). There was no statistically significant difference in patient-reported or objectively measured GFD adherence.TEACH is an effective intervention among patients with CD to improve patient activation and QOL, even among a cohort with GFD adherence at baseline.ClinicalTrials.gov: NCT02458898.

    View details for DOI 10.1016/j.jpeds.2017.02.062

    View details for PubMedID 28343658

  • HCV Prevalence in Asian Americans in California JOURNAL OF IMMIGRANT AND MINORITY HEALTH Lin, O. N., Chang, C., Lee, J., Ailinh Do, A., Martin, M., Martin, A., Nguyen, M. H. 2017; 19 (1): 91-97

    Abstract

    The World Health Organization estimates that 170 million persons are infected with HCV worldwide, but only 22 million are from the Americas and Europe, compared to 94 million from Asia. HCV prevalence in the general US population is 1.6 %, but data for Asian Americans are limited. Our goal was to examine HCV prevalence in Asian Americans in a large ethnically diverse patient cohort seeking primary care at a free clinic in Northern California. A total of 1347 consecutive patients were seen from September 2009 to October 2012 and were studied via individual chart review using case report forms. HCV infection was defined as positive HCV antibody (anti-HCV) or HCV RNA by PCR. 699 out of 1347 patients were screened for HCV. Asian Americans comprised 57.2 % of these patients and 29 (4.1 %) patients tested positive for HCV. Of these 29 HCV-positive patients, 22 (75.9 %) were Asian, yielding a prevalence of 5.5 % for Asians and 2.3 % for non-Asians (P = 0.038). The highest HCV prevalence was seen in Vietnamese patients at 7.9 %, and 6.0 % in Chinese patients. Of the HCV-positive Asians, none had a history of intravenous drug use (IVDU), tattoos, or sexual exposure. On multivariate analysis, significant independent predictors for positive HCV infection were male gender (OR 2.53, P = 0.02) and presence of known risk factors (OR 21.1, P < 0.001). However, older age and Asian ethnicity were found to be significant predictors of HCV infection (OR 1.03, P = 0.05 and 2.31, P = 0.066, respectively). In our study, HCV prevalence in patients seeking routine primary care was 5.5 % in Asian Americans, which was over double the prevalence for non-Asians at 2.3 %. Known risk factors were also notably absent in Asian patients with HCV infection. The high prevalence of HCV in Asian-Americans is likely reflective of the higher prevalence of HCV in their countries of origin in Asia. Asian-Americans immigrants from endemic countries are at higher risk of HCV infection and should be screened for HCV, regardless of their exposure risk profile.

    View details for DOI 10.1007/s10903-016-0342-1

    View details for Web of Science ID 000394213200012

  • HCV Prevalence in Asian Americans in California. Journal of immigrant and minority health Lin, O. N., Chang, C., Lee, J., Do, A., Martin, M., Martin, A., Nguyen, M. H. 2016: -?

    Abstract

    The World Health Organization estimates that 170 million persons are infected with HCV worldwide, but only 22 million are from the Americas and Europe, compared to 94 million from Asia. HCV prevalence in the general US population is 1.6 %, but data for Asian Americans are limited. Our goal was to examine HCV prevalence in Asian Americans in a large ethnically diverse patient cohort seeking primary care at a free clinic in Northern California. A total of 1347 consecutive patients were seen from September 2009 to October 2012 and were studied via individual chart review using case report forms. HCV infection was defined as positive HCV antibody (anti-HCV) or HCV RNA by PCR. 699 out of 1347 patients were screened for HCV. Asian Americans comprised 57.2 % of these patients and 29 (4.1 %) patients tested positive for HCV. Of these 29 HCV-positive patients, 22 (75.9 %) were Asian, yielding a prevalence of 5.5 % for Asians and 2.3 % for non-Asians (P = 0.038). The highest HCV prevalence was seen in Vietnamese patients at 7.9 %, and 6.0 % in Chinese patients. Of the HCV-positive Asians, none had a history of intravenous drug use (IVDU), tattoos, or sexual exposure. On multivariate analysis, significant independent predictors for positive HCV infection were male gender (OR 2.53, P = 0.02) and presence of known risk factors (OR 21.1, P < 0.001). However, older age and Asian ethnicity were found to be significant predictors of HCV infection (OR 1.03, P = 0.05 and 2.31, P = 0.066, respectively). In our study, HCV prevalence in patients seeking routine primary care was 5.5 % in Asian Americans, which was over double the prevalence for non-Asians at 2.3 %. Known risk factors were also notably absent in Asian patients with HCV infection. The high prevalence of HCV in Asian-Americans is likely reflective of the higher prevalence of HCV in their countries of origin in Asia. Asian-Americans immigrants from endemic countries are at higher risk of HCV infection and should be screened for HCV, regardless of their exposure risk profile.

    View details for PubMedID 26798070

  • High Prevalence of Hepatitis C Virus in Asian-Americans: Results of Office-Based Primary Care Screening Lin, O., Chang, C. Y., Lee, J. Y., Do, A., Martin, M. H., Martin, A. B., Nguyen, M. H. WILEY-BLACKWELL. 2013: 1308A
  • Generation of a bacterium with a 21 amino acid genetic code. Journal of the American Chemical Society Mehl, R. A., Anderson, J. C., Santoro, S. W., Wang, L., Martin, A. B., King, D. S., Horn, D. M., Schultz, P. G. 2003; 125 (4): 935?39

    Abstract

    We have generated a completely autonomous bacterium with a 21 amino acid genetic code. This bacterium can biosynthesize a nonstandard amino acid from basic carbon sources and incorporate this amino acid into proteins in response to the amber nonsense codon. The biosynthetic pathway for the amino acid p-aminophenylalanine (pAF) as well as a unique pAF synthetase and cognate tRNA were added to Escherichia coli. Denaturing gel electrophoresis and mass spectrometric analysis show that pAF is incorporated into myoglobin with fidelity and efficiency rivaling those of the common 20 amino acids. This and other such organisms may provide an opportunity to examine the evolutionary consequences of adding new amino acids to the genetic repertoire, as well as generate proteins with new or enhanced biological functions.

    View details for DOI 10.1021/ja0284153

    View details for PubMedID 12537491

  • Addition of p-azido-L-phenylalanine to the genetic code of Escherichia coli. Journal of the American Chemical Society Chin, J. W., Santoro, S. W., Martin, A. B., King, D. S., Wang, L., Schultz, P. G. 2002; 124 (31): 9026?27

    Abstract

    We report the selection of a new orthogonal aminoacyl tRNA synthetase/tRNA pair for the in vivo incorporation of a photocrosslinker, p-azido-l-phenylalanine, into proteins in response to the amber codon, TAG. The amino acid is incorporated in good yield with high fidelity and can be used to crosslink interacting proteins.

    View details for DOI 10.1021/ja027007w

    View details for PubMedID 12148987

  • Addition of a photocrosslinking amino acid to the genetic code of Escherichiacoli. Proceedings of the National Academy of Sciences of the United States of America Chin, J. W., Martin, A. B., King, D. S., Wang, L., Schultz, P. G. 2002; 99 (17): 11020?24

    Abstract

    Benzophenones are among the most useful photocrosslinking agents in biology. We have evolved an orthogonal aminoacyl-tRNA synthetase/tRNA pair that makes possible the in vivo incorporation of p-benzoyl-l-phenylalanine into proteins in Escherichia coli in response to the amber codon, TAG. This unnatural amino acid was incorporated with high translational efficiency and fidelity into the dimeric protein glutathione S-transferase. Irradiation resulted in efficient crosslinking (>50%) of the protein subunits. This methodology may prove useful for discovering and defining protein interactions in vitro and in vivo.

    View details for DOI 10.1073/pnas.172226299

    View details for PubMedID 12154230

    View details for PubMedCentralID PMC123203

  • Single-molecule protein folding: Diffusion fluorescence resonance energy transfer studies of the denaturation of chymotrypsin inhibitor 2 PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA Deniz, A. A., Laurence, T. A., Beligere, G. S., Dahan, M., Martin, A. B., Chemla, D. S., Dawson, P. E., Schultz, P. G., Weiss, S. 2000; 97 (10): 5179?84

    Abstract

    We report single-molecule folding studies of a small, single-domain protein, chymotrypsin inhibitor 2 (CI2). CI2 is an excellent model system for protein folding studies and has been extensively studied, both experimentally (at the ensemble level) and theoretically. Conformationally assisted ligation methodology was used to synthesize the proteins and site-specifically label them with donor and acceptor dyes. Folded and denatured subpopulations were observed by fluorescence resonance energy transfer (FRET) measurements on freely diffusing single protein molecules. Properties of these subpopulations were directly monitored as a function of guanidinium chloride concentration. It is shown that new information about different aspects of the protein folding reaction can be extracted from such subpopulation properties. Shifts in the mean transfer efficiencies are discussed, FRET efficiency distributions are translated into potentials, and denaturation curves are directly plotted from the areas of the FRET peaks. Changes in stability caused by mutation also are measured by comparing pseudo wild-type CI2 with a destabilized mutant (K17G). Current limitations and future possibilities and prospects for single-pair FRET protein folding investigations are discussed.

    View details for DOI 10.1073/pnas.090104997

    View details for Web of Science ID 000086998500034

    View details for PubMedID 10792044

    View details for PubMedCentralID PMC25802

  • Opportunities at the interface of chemistry and biology TRENDS IN BIOCHEMICAL SCIENCES Martin, A. B., Schultz, P. G. 1999; 24 (12): M24?M28

    Abstract

    The combination of the tools and principles of chemistry, together with the tools of modern molecular biology, allow us to create complex synthetic and natural molecules, and processes with novel biological, chemical and physical properties. This article illustrates the tremendous opportunity that lies at this interface of chemistry and biology by describing a number of examples, ranging from efforts to expand the genetic code of living organisms to the use of combinatorial methods to generate biologically active synthetic molecules.

    View details for DOI 10.1016/S0968-0004(99)01498-X

    View details for Web of Science ID 000084258700008

    View details for PubMedID 10611676

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