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Featured researches published by Brian L. Chang.


Combinatorial Chemistry & High Throughput Screening | 2010

High Throughput Binding Analysis Determines the Binding Specificity of ASF/SF2 on Alternatively Spliced Human Pre-mRNAs

Brian L. Chang; J. Levin; William A. Thompson; William G. Fairbrother

High-throughput immunoprecipitation studies of transcription factors and splicing factors have revolutionized the fields of transcription and splicing. Recent location studies on Nova1/2 and Fox2 have identified a set of cellular targets of these splicing factors. One problem with identifying binding sites for splicing factors arises from the transient role of RNA in gene expression. The primary role of most splicing factors is to bind pre-mRNA co-transcriptionally and participate in the extremely rapid process of splice site selection and catalysis. Pre-mRNA is a labile species with a steady state level that is three orders of magnitude less abundant than mRNA. As many splicing factors also bind mRNA to some degree, these substrates tend to dominate the output of location studies. Here we present an in-vitro method for screening RNA protein interactions that circumvents these problems. We screen approximately 4000 alternatively spliced exons and the entire Hepatitis C genome for binding of ASF/SF2, the only splicing factor demonstrated to function as an oncogene. From the pre-mRNA sequences returned in this screen we discovered physiologically relevant ASF recognition element motifs. ASF binds two motifs: a C-rich and a purine rich motif. Comparisons with similar data derived from the hnRNP protein PTB reveals little overlap between strong PTB and ASF/SF2 sites. We illustrate how this method could be employed to screen disease alleles with the set of small molecules that have been shown to alter splicing in search for therapies for splicing diseases.


Plastic and reconstructive surgery. Global open | 2016

Technical Considerations for Filler and Neuromodulator Refinements

José Raúl Montes; Anthony J. Wilson; Brian L. Chang; Ivona Percec

Background: The toolbox for cosmetic practitioners is growing at an unprecedented rate. There are novel products every year and expanding off-label indications for neurotoxin and soft-tissue filler applications. Consequently, aesthetic physicians are increasingly challenged by the task of selecting the most appropriate products and techniques to achieve optimal patient outcomes. Methods: We employed a PubMed literature search of facial injectables from the past 10 years (2005–2015), with emphasis on those articles embracing evidence-based medicine. We evaluated the scientific background of every product and the physicochemical properties that make each one ideal for specific indications. The 2 senior authors provide commentary regarding their clinical experience with specific technical refinements of neuromodulators and soft-tissue fillers. Results: Neurotoxins and fillers are characterized by unique physical characteristics that distinguish each product. This results in subtle but important differences in their clinical applications. Specific indications and recommendations for the use of the various neurotoxins and soft-tissue fillers are reviewed. The discussion highlights refinements in combination treatments and product physical modifications, according to specific treatment zones. Conclusions: The field of facial aesthetics has evolved dramatically, mostly secondary to our increased understanding of 3-dimensional structural volume restoration. Our work reviews Food and Drug Administration–approved injectables. In addition, we describe how to modify products to fulfill specific indications such as treatment of the mid face, décolletage, hands, and periorbital regions. Although we cannot directly evaluate the duration or exact physical properties of blended products, we argue that “product customization” is safe and provides natural results with excellent patient outcomes.


Plastic and Reconstructive Surgery | 2016

A Quantitative Analysis of Onabotulinumtoxina, Abobotulinumtoxina, and Incobotulinumtoxina: A Randomized, Double-blind, Prospective Clinical Trial of Comparative Dynamic Strain Reduction

Anthony J. Wilson; Brian L. Chang; Anthony J. Taglienti; Bianca C. Chin; Catherine S. Chang; Nancy Folsom; Ivona Percec

Background: U.S. Food and Drug Administration–approved formulations of botulinum toxin include onabotulinumtoxinA (Botox; Allergan, Inc., Irvine, Calif.), abobotulinumtoxinA (Dysport; Galderma Pharma S.A., Lausanne, Switzerland), and incobotulinumtoxinA (Xeomin; Merz Pharmaceuticals GmbH, Frankfurt am Main, Germany). This study uses digital image correlation to compare dynamic strain reduction between available neurotoxins. Methods: Seventy-three treatment-naive female patients aged were randomized to injection with onabotulinumtoxinA (20 units), abobotulinumtoxinA (60 units), or incobotulinumtoxinA (20 units) in the glabella. Imaging was conducted at 4, 14, and 90 days after injection. Change in average dynamic strain of the glabella was compared using ANOVA. Results: At day 4, there was a 42.1 percent strain reduction in the onabotulinumtoxinA group, a 39.4 percent strain reduction in the abobotulinumtoxinA group, and a 19.8 percent strain reduction in the incobotulinumtoxinA group (onabotulinumtoxinA versus abobotulinumtoxinA, p = 0.77; onabotulinumtoxinA versus incobotulinumtoxinA, p = 0.02; and abobotulinumtoxinA versus incobotulinumtoxinA, p = 0.04). At day 14, there was a 66.1 percent strain reduction in the onabotulinumtoxinA group, a 51.4 percent strain reduction in the abobotulinumtoxinA group, and a 42.8 percent strain reduction in the incobotulinumtoxinA group (onabotulinumtoxinA versus abobotulinumtoxinA, p = 0.14; onabotulinumtoxinA versus incobotulinumtoxinA, p = 0.02; and abobotulinumtoxinA versus incobotulinumtoxinA, p = 0.36). At day 90, there was a 43.5 percent strain reduction in the onabotulinumtoxinA group, a 38.4 percent strain reduction in the abobotulinumtoxinA group, and a 25.3 percent strain reduction in the incobotulinumtoxinA group (onabotulinumtoxinA versus abobotulinumtoxinA, p = 0.66; onabotulinumtoxinA versus incobotulinumtoxinA, p = 0.12; and abobotulinumtoxinA versus incobotulinumtoxinA, p = 0.24). Conclusions: Using digital image correlation, the tested neuromodulators do not have equivalent strain reduction in the glabella at the doses used. These results confirm assertions of noninterchangeability. CLINICAL QUESTION/LEVEL OF EVIDENCE: Therapeutic, II.


Academic Emergency Medicine | 2016

Tweet Now, See You In the ED Later? Examining the Association Between Alcohol-related Tweets and Emergency Care Visits

Megan L. Ranney; Brian L. Chang; Joshua R. Freeman; Brian Norris; Mark Silverberg; Esther K. Choo; Mark B. Mycyk

BACKGROUND Alcohol use is a major and unpredictable driver of emergency department (ED) visits. Regional Twitter activity correlates ecologically with behavioral outcomes. No such correlation has been established in real time. OBJECTIVES The objective was to examine the correlation between real-time, alcohol-related tweets and alcohol-related ED visits. METHODS We developed and piloted a set of 11 keywords that identified tweets related to alcohol use. In-state tweets were identified using self-declared profile information or geographic coordinates. Using Datasift, a third-party vendor, a random sample of 1% of eligible tweets containing the keywords and originating in state were downloaded (including tweet date/time) over 3 discrete weeks in 3 different months. In the same time frame, we examined visits to an urban, high-volume, Level I trauma center that receives > 25% of the emergency care volume in the state. Alcohol-related ED visits were defined as visits with a chief complaint of alcohol use, positive blood alcohol, or alcohol-related ICD-9 code. Spearmans correlation coefficient was used to examine the hourly correlation between alcohol-related tweets, alcohol-related ED visits, and all ED visits. RESULTS A total of 7,820 tweets (representing 782,000 in-state alcohol-related tweets during the 3 weeks) were identified. Concurrently, 404 ED visits met criteria for being alcohol-related versus 2939 non-alcohol-related ED visits. There was a statistically significant relationship between hourly alcohol-related tweet volume and number of alcohol-related ED visits (rs = 0.31, p < 0.00001), but not between hourly alcohol-related tweet volume and number of non-alcohol-related ED visits (rs = -0.07, p = 0.11). CONCLUSION In a single state, a statistically significant relationship was observed between the hourly number of alcohol-related tweets and the hourly number of alcohol-related ED visits. Real-time Twitter monitoring may help predict alcohol-related surges in ED visits. Future studies should include larger numbers of EDs and natural language processing.


The Cleft Palate-Craniofacial Journal | 2017

Influence of Standardized Orientation on Patient Perception of Perioperative Care Following Alveolar Cleft Repair: A Survey Based Study of Patients Treated in a Large Academic Medical Center

Brian L. Chang; Anthony J. Wilson; Bianca C. Chin; Christopher Friedman; Oksana Jackson

Objective This study aims to better understand patient-reported outcomes for iliac bone grafting surgery for alveolar cleft repair and to determine how standardizing perioperative patient instruction affects patient-reported outcomes. Design Retrospective survey-based assessment of patients undergoing iliac bone grafting with and without hospital-based systems standardization. Setting Academic tertiary care hospital. Patients Of the 195 identified patients, 127 participated. Interventions Survey on pain and satisfaction regarding iliac bone grafting surgery. Main Outcome Measures Survey answers measured patient opinions about the surgery. Answers of the pre- and poststandardization patients were compared to determine the effect of standardizing patient instructions. Results Patients rated their satisfaction with the surgery and recovery a 4.5 and 4.4 out of 5, respectively. They rated their overall pain in the hospital a 5.5 out of 10 (4.9 in the mouth, 5.7 in the hip). Patients were discharged an average of 1.2 days after surgery and could return to normal daily activity in 6.1 days. Poststandardization patients were more likely to adhere to instructions regarding use of an antibacterial mouthrinse and a protective oral splint. Conclusions Patients were highly satisfied with the iliac bone grafting procedure and the recovery and reported only moderate levels of postoperative pain. Implementing standardized patient instructions may not affect patient satisfaction or pain severity, but it significantly increased patient adherence to physician instructions.


Western Journal of Emergency Medicine | 2018

Variations in Cardiac Arrest Regionalization in California

Brian L. Chang; Mary P. Mercer; Nichole Bosson; Karl A. Sporer

Introduction The development of cardiac arrest centers and regionalization of systems of care may improve survival of patients with out-of-hospital cardiac arrest (OHCA). This survey of the local EMS agencies (LEMSA) in California was intended to determine current practices regarding the treatment and routing of OHCA patients and the extent to which EMS systems have regionalized OHCA care across California. Methods We surveyed all of the 33 LEMSA in California regarding the treatment and routing of OHCA patients according to the current recommendations for OHCA management. Results Two counties, representing 29% of the California population, have formally regionalized cardiac arrest care. Twenty of the remaining LEMSA have specific regionalization protocols to direct all OHCA patients with return of spontaneous circulation to designated percutaneous coronary intervention (PCI)-capable hospitals, representing another 36% of the population. There is large variation in LEMSA ability to influence inhospital care. Only 14 agencies (36%), representing 44% of the population, have access to hospital outcome data, including survival to hospital discharge and cerebral performance category scores. Conclusion Regionalized care of OHCA is established in two of 33 California LEMSA, providing access to approximately one-third of California residents. Many other LEMSA direct OHCA patients to PCI-capable hospitals for primary PCI and targeted temperature management, but there is limited regional coordination and system quality improvement. Only one-third of LEMSA have access to hospital data for patient outcomes.


The Cleft Palate-Craniofacial Journal | 2018

Quantifying Pediatric Facial Palsy:: Using Digital Image Correlation to Objectively Characterize Pediatric Facial Symmetry

Brian L. Chang; Anthony J. Wilson; Fares Samra; Tami Konieczny; Ivona Percec; Melissa Lanning; Christopher Friedman; Oksana Jackson

Objective: This study introduces digital image correlation (DIC) as a novel technology to objectively quantify pediatric facial symmetry. Design: Descriptive cohort study of patients’ facial symmetry as measured by DIC. Setting: Academic tertiary care hospital. Patients: 9 of 12 identified facial palsy and 13 of 26 identified control subjects participated. Interventions: DIC was used to quantify facial strain and symmetry as patients made the 5 standard Sunnybrook facial expressions. Each subject was evaluated according to the Sunnybrook scale by 4 evaluators, 3 plastic surgeons, and 1 occupational therapist. Main Outcome Measure: The percentage asymmetry values were calculated and compared between the facial palsy and control groups using both DIC and Sunnybrook. Results: Using DIC, facial palsy subjects had 32.99% asymmetry compared with 14.84% in controls (P < .01). Using Sunnybrook, facial palsy subjects had 24.11% asymmetry compared to 3.87% in controls (P < .01). The 2 metrics were positively correlated (P < .01). There was significant variability among the Sunnybrook evaluators (P = .02). Conclusions: DIC is a novel technique of objectively quantifying facial motion of the animated face. As surgical and medical approaches toward facial palsy expand, it is essential to have a means to compare results and improve patient outcomes.


Aesthetic Surgery Journal | 2018

Perioral Rejuvenation: A Prospective, Quantitative Dynamic Three-Dimensional Analysis of a Dual Modality Treatment

Catherine S. Chang; Brian L. Chang; Michael Lanni; Anthony J. Wilson; Jacob Beer; Ivona Percec

Background The perioral region is the most dynamic anatomic area of the face and subject to complex and dramatic changes during aging. Successful treatment for perioral rejuvenation has yet to be identified, and prior studies have reported only subjective outcomes. Objectives The purpose of this study was to utilize our validated dynamic 3-dimensional imaging technology to determine whether conservative neuromodulation combined with hyaluronic acid filler volumization can decrease perioral strain and increase volume with significant patient satisfaction. Methods An IRB-approved prospective study of a dual modality treatment for perioral rhytids was performed on females with perioral aging who had not had prior facial treatment within the past year. Eighteen (18) units of Dysport were injected into the upper and lower orbicularis oris and 1 cc of Restylane Silk was injected in volume-depleted perioral regions in each patient. Each patient underwent imaging with digital image correlation (DIC) and completed the FACE-Q survey prior to injection and at 14 days and 90 days postinjection. Results Thirty-two female patients were recruited. A significant reduction in perioral strain was observed at both day 14 and day 90. This was concomitant with a significant increase in perioral volume at day 14 that at 90 days was significantly retained in the marionette lines. Further, there was a significant improvement in patient satisfaction with overall facial appearance at day 14 that was maintained at 90 days. Conclusions Conservative neuromodulation and hyaluronic acid filler volumization of the perioral region produces a significant reduction in strain correlating with high patient satisfaction, even at 90 days. This dual modality treatment is effective in rejuvenating the perioral region, and its future optimization will provide greater therapeutic options for this anatomically complex area. Level of Evidence 4


RNA | 2009

Next-generation SELEX identifies sequence and structural determinants of splicing factor binding in human pre-mRNA sequence

Daniel Brian Carlin Reid; Brian L. Chang; Samuel I. Gunderson; Lauren Alpert; William A. Thompson; William G. Fairbrother


Biochemical and Biophysical Research Communications | 2003

Prediction of tyrosine sulfation sites in animal viruses.

Henry C. Lin; Kevin Tsai; Brian L. Chang; Justin Liu; Melinda Young; Willy Hsu; Samuel Louie; Hugh B. Nicholas; Grace L. Rosenquist

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Ivona Percec

University of Pennsylvania

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Anthony J. Wilson

University of Pennsylvania

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Catherine S. Chang

Hospital of the University of Pennsylvania

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Nancy Folsom

University of Pennsylvania

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Bianca C. Chin

University of Pennsylvania

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Christopher Friedman

Children's Hospital of Philadelphia

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Jacob Beer

Hospital of the University of Pennsylvania

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Karl A. Sporer

University of California

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Mary P. Mercer

University of California

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