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  • Clinical Instructor, Radiology

Publications

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  • Nearing the Summit: Associating Liver Partitioning and Portal Ligation for Staged Hepatectomy (ALPPS) in Progressive Carcinoid Disease. Digestive diseases and sciences Bergquist, J. R., Li, A. Y., Chang, E. M., Scott, G. D., Dua, M. M., Visser, B. C. 2020

    View details for DOI 10.1007/s10620-020-06257-8

    View details for PubMedID 32307614

  • Brain Diffusion Imaging Findings May Predict Clinical Outcome after Cardiac Arrest. Journal of neuroimaging : official journal of the American Society of Neuroimaging Oren, N. C., Chang, E., Yang, C. W., Lee, S. K. 2019; 29 (4): 540?47

    Abstract

    We aim to correlate the patterns of brain diffusion-weighted imaging (DWI) and apparent diffusion coefficient (ADC) map in post cardiac arrest (PCA) patients with clinical outcomes.Thirty-eight adult patients with PCA (mean age, 52.8 years; range 18-87 years) whose DWI obtained within 5 days of PCA were retrospectively reviewed. The visual DWI/ADC map categories include: Group 1: Normal; Group 2a: Mild [restricted diffusion (RD) < 1/3 cortical involvement (CI)]); Group 2b: Moderate (RD 1/3 > and < 2/3 CI); Group 2c: Severe (RD > 2/3 CI); and Group 3: Embolic (scattered, discrete foci of RD). Clinical outcomes were categorized according to cerebral performance categories (CPC) and modified Rankin scale (mRS).The most common DWI/ADC map pattern was Group 1 (28.9%, n = 11). The incidence of other DWI patterns such as Group 2a, 2b, 2c, and 3 were 21% (n = 8), 10.5% (n = 4), 21% (n = 8), and 18.4% (n = 7), respectively. Twenty-seven patients (71%) were CPC-5/mRS-6 and died or were category CPC-4/mRS-5, and 4 patients were CPC-1/mRS 0-1 (10.5%). Interobserver agreement for visual classification of DWI/ADC map patterns was excellent (kappa = .8795). There was moderate positive correlation between clinical outcomes and visual DWI classification (r = .461, P = .00358). The positive predictive value of this qualitative classification on DWI/ADC in predicting a poor clinical outcome (CPC-4/mRS-5 and CPC-5/mRS-6) was 81.4 % in the presence of restricted diffusion.Simple visual categorization system using DWI/ADC map may be helpful and practical in estimating the clinical outcome of PCA patients.

    View details for DOI 10.1111/jon.12626

    View details for PubMedID 31107566

  • AMPK activation regulates neuronal structure in developing hippocampal neurons. Neuroscience Ramamurthy, S., Chang, E., Cao, Y., Zhu, J., Ronnett, G. V. 2014; 259: 13?24

    Abstract

    AMP-activated protein kinase (AMPK) is a serine/threonine kinase that functions as a cellular and whole organism energy sensor to regulate ATP-consuming (anabolic) and ATP-generating (catabolic) pathways. The heterotrimeric AMPK complex consists of a catalytic ?-subunit, regulatory ?-subunit, and an AMP/ATP-binding ?-subunit. Several alternate isoforms exist for each subunit (?1, ?2, ?1, ?2, ?1, ?2 and ?3). However, little is known of the expression pattern or function of the individual catalytic complexes in regulating neuronal structure. In this study, we examined the role of AMPK subunits in differentiating hippocampal neurons. We found that during development, the expression of AMPK subunits increase and that activation of AMPK by energetic stress inhibits neuronal development at multiple stages, not only during axon outgrowth, but also during dendrite growth and arborization. The presence of a single functional AMPK catalytic complex was sufficient to mediate these inhibitory effects of energetic stress. Activation of AMPK mediates these effects by suppressing both the mTOR and Akt signaling pathways. These findings demonstrate that the energy-sensing AMPK pathway regulates neuronal structure in distinct regions of developing neurons at multiple stages of development.

    View details for DOI 10.1016/j.neuroscience.2013.11.048

    View details for PubMedID 24295634

  • A cohort evaluation of the laryngeal mask airway-Supreme? in children. Paediatric anaesthesia Jagannathan, N., Sohn, L. E., Chang, E., Sawardekar, A. 2012; 22 (8): 759?64

    Abstract

    To assess the clinical performance of the laryngeal mask airway-Supreme in children.The purpose of this prospective audit was to evaluate the feasibility of the laryngeal mask airway-Supreme in clinical practice and generate data for future comparison trials.The laryngeal mask airway-Supreme is a new second-generation supraglottic airway that was recently released in limited pediatric sizes (sizes 1, 2).One hundred children, ASA I-III, newborn to 16 years of age, and undergoing various procedures requiring a size 1, 2, or 3 laryngeal mask airway-Supreme were studied. Assessments included insertion success rates, airway leak pressures, success of gastric tube insertion, quality of airway, and perioperative complications.The first-time insertion success rate was 97%, with an overall insertion success rate of 100%. The mean initial airway leak pressure for all patients was 22.3 6.6 cm H(2) O. Gastric tube placement was possible in 98% of patients. Complications were noted in six patients: coughing or laryngospasm (n = 3), sore throat (n = 1), and dysphonia (n = 2).The laryngeal mask airway-Supreme was inserted with a high degree of success on the first attempt by clinicians with limited prior experience with the device. It was effectively used for a variety of procedures in children undergoing spontaneous and mechanical ventilation with minimal complications. The leak pressures demonstrated in this study, along with access for gastric decompression, suggest that the laryngeal mask airway-Supreme may be an effective device for positive pressure ventilation in children.

    View details for DOI 10.1111/j.1460-9592.2012.03832.x

    View details for PubMedID 22416790

  • A randomised trial comparing the laryngeal mask airway Supreme? with the laryngeal mask airway Unique? in children. Anaesthesia Jagannathan, N., Sohn, L. E., Sawardekar, A., Chang, E., Langen, K. E., Anderson, K. 2012; 67 (2): 139?44

    Abstract

    We conducted a randomised controlled trial comparing the laryngeal mask airway Supreme(?) with the laryngeal mask airway Unique(?) in children. Fifty children presenting for elective surgery were randomly assigned to receive either the laryngeal mask airway Supreme or laryngeal mask airway Unique. The outcomes measured were airway leak pressure, ease and time for insertion, insertion success rate, fibreoptic examination, incidence of gastric insufflation, ease of gastric tube placement through the laryngeal mask airway Supreme, quality of airway during anaesthetic maintenance and complications. Median (IQR [range]) time to successful device placement was shorter with the laryngeal mask airway Unique, 14.5 [13.5-16.3 (10.0-23.6)] s than with the laryngeal mask airway Supreme, 17.4 [14.8-19.8 (11.5-29.2)] s; p = 0.007. Median (IQR [range]) airway leak pressures for the laryngeal mask airway Supreme and laryngeal mask airway Unique were 20 [16-21 (12-22)] cmH(2)O and 15 [14-18 (10-24)] cmH(2)O, respectively (p = 0.001). The incidence of gastric insufflation was lower with the laryngeal mask airway Supreme (zero vs six patients), p = 0.01. In conclusion, the laryngeal mask airway Supreme performed as well as the laryngeal mask airway Unique and is a useful alternative for airway maintenance, particularly in children who require evacuation of gastric contents during anaesthesia.

    View details for DOI 10.1111/j.1365-2044.2011.06960.x

    View details for PubMedID 22070630

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