About

Dr. Alan Chang is a Clinical Associate Professor in Medicine at Stony Brook University, specializing in Endocrinology. He is based in Lake Grove, NY, and accepts new patients for endocrine-related health issues. Dr. Chang completed his medical education at St George's University School of Medicine in 2009. He further specialized through a residency and internship at Hahnemann University Hospital, both in Internal Medicine, in 2010 and 2012 respectively. He also completed a fellowship in IM-Endo/Diab/Metab at Hahnemann University Hospital in 2014. His board certification in Endocrinology, Diabetes, and Metabolism was obtained from the American Board of Internal Medicine in 2014. Dr. Chang's professional focus includes the diagnosis and treatment of endocrine disorders, and he practices at locations including the Stony Brook Internists - Endocrinology in Lake Grove, NY.

Research topics

• Computer Science
• Chemistry
• Crystallography
• Stereochemistry
• Urology
• Pharmacology
• Medicine
• Internal medicine
• Biochemistry
• Biology
• Surgery
• Microbiology
• Materials science

Selected publications

• PO-04-013 NATIONWIDE SAFETY ASSESSMENT OF OVER 20,000 PULSED FIELD AND 10,000 THERMAL ABLATIONS FOR ATRIAL FIBRILLATION IN THE UNITED STATES

  Heart Rhythm · 2026-04-01

  article
  PublisherDOI

• EPH59 Application of Prevalent New-User Cohort Designs to a Claims Data Study of Incidence of Nutritional Deficiency in People With Diabetes Using GLP-1 Receptor Agonists

  Value in Health · 2025-07-01

  article
  PublisherDOI

• Oncological and functional outcomes of men undergoing primary whole gland cryoablation of the prostate: A 20‐year experience

  Cancer · 2022-09-15 · 23 citations

  article

  BACKGROUND: This study reports the oncological and functional outcomes in men with localized prostate cancer (Pca) who were treated with primary whole gland cryoablation (WGC) of the prostate. METHODS: The authors retrospectively reviewed their prospectively collected cryosurgery database between January 2002 and September 2019 for men who were treated with WGC of the prostate at a tertiary referral center. Primary outcome includes biochemical recurrence-free survival (BRFS). Secondary outcomes include failure-free survival (FFS), metastasis-free survival (MFS) and adverse events. RESULTS: A total of 260 men were included in the study. Men having had prior treatment for Pca were excluded. Median follow-up was 107 months (interquartile range [IQR], 68.3-132.5 months). BRFS, FFS, and MFS at 10 years were 84%, 66%, and 96%, respectively. High risk D'Amico classification was associated with a lower BRFS and FFS on multivariable analysis. No patient had any Pca-related death during follow-up. American Urological Association symptoms score and bother index were unchanged following cryoablation. Median International Index of Erectile Function score precryoablation and post-cryoablation was 7 (IQR, 3-11) and 1 (IQR, 1-5), respectively. Stress urinary incontinence, defined as requiring any protective pads only occurred in five patients (2%). No patient developed a fistula. Grade > 2 Clavien-Dindo adverse events occurred in six (2.3%) patients. CONCLUSION: WGC of the prostate can achieve excellent oncological and functional outcomes in men with localized Pca at the 10-year mark. Primary WGC may be a good option for men who desire to preserve urinary continence and have an excellent oncologic outcome. LAY SUMMARY: Primary whole gland cryoablation is an alternative treatment option to radical prostatectomy and radiotherapy for men with organ-confined prostate cancer. Patients had excellent cancer outcomes 1 years after whole gland cryoablation, and patients with PSA nadir 0.1 ng/ml or lower after treatment were less likely to have disease recurrence.

  PublisherDOI

• Automated versus manual analysis of body composition measures on computed tomography in patients with bladder cancer

  European Journal of Radiology · 2022-06-16 · 19 citations

  articleOpen access
  PublisherOA PDFDOI

• Oncological and Functional Outcomes of Patients Undergoing Individualized Partial Gland Cryoablation of the Prostate: A Single-Institution Experience

  Journal of Endourology · 2021 · 36 citations

  • Medicine
  • Surgery
  • Urology

  Individualized partial gland cryoablation of the prostate is able to achieve excellent oncological and functional outcomes in select men with localized prostate cancer.

  PublisherOA PDFDOI

• Tandem UU:GA mismatch within an RNA helix

  2020-02-28

  paratextSenior author
  PublisherDOI

• Safety and efficacy of intravesical chemotherapy and hyperthermia in the bladder: results of a porcine study

  International Journal of Hyperthermia · 2020 · 21 citations

  • Medicine
  • Urology
  • Pharmacology

  BACKGROUND: Hyperthermia (heating to 43 °C) activates the innate immune system and improves bladder cancer chemosensitivity. OBJECTIVE: To evaluate the tissue penetration and safety of convective hyperthermia combined with intravesical mitomycin C (MMC) pharmacokinetics in live porcine bladder models using the Combat bladder recirculation system (BRS). METHODS: Forty 60 kg-female swine were anesthetized and catheterized with a 3-way, 16 F catheter. The Combat device was used to heat the bladders to a target temperature of 43 °C with recirculating intravesical MMC at doses of 40, 80, and 120 mg. Dwell-heat time varied from 30-180 min. Rapid necropsy with immediate flash freezing of tissues, blood and urine occurred. MMC concentrations were measured by liquid chromatography tandem-mass spectrometry. RESULTS: The Combat BRS system was able to achieve target range temperature (42-44 °C) in 12 mins, and this temperature was maintained as long as the device was running. Two factors increased tissue penetration of MMC in the bladder: drug concentration, and the presence of heat. In the hyperthermia arm, MMC penetration saturated at 80 mg, suggesting that with heating, drug absorption may saturate and not require higher doses to achieve the maximal biological effect. Convective hyperthermia did not increase the MMC concentration in the liver, heart, kidney, spleen, lung, and lymph node tissue even at the 120 mg dose. CONCLUSIONS: Convective bladder hyperthermia using the Combat BRS device is safe and the temperature can be maintained at 43 °C. Hyperthermia therapy may increase MMC penetration into the bladder wall but does not result in an increase of MMC levels in other organs.

  PublisherOA PDFDOI

• 2-amino-1,3-benzothiazole-6-carboxamide Preferentially Binds the Tandem Mismatch Motif r(UY:GA)

  bioRxiv (Cold Spring Harbor Laboratory) · 2020

  1st authorCorresponding
  • Chemistry
  • Stereochemistry
  • Crystallography

  Abstract RNA helices are often punctuated with non-Watson-Crick features that can be the target of chemical compounds, but progress towards identifying small molecules specific for non-canonical elements has been slow. We have used a tandem UU:GA mismatch motif (5’-UG-3’:5’-AU-3’) embedded within the helix of an RNA hairpin as a model to identify compounds that bind the motif specifically. The three-dimensional structure of the RNA hairpin and its interaction with a small molecule compound identified through a virtual screen are presented. The G-A of the mismatch forms a sheared pair upon which the U-U base pair stacks. The hydrogen bond configuration of the U-U pair involves the O2 of the U adjacent to the G and the O4 of the U adjacent to the A. The G-A and U-U pairs are flanked by A-U and G-C base pairs, respectively, and the mismatch exhibits greater stability than when the motif is within the context of other flanking base pairs or when the 5’-3’ orientation of the G-A and U-U is swapped. Residual dipolar coupling constants were used to generate an ensemble of structures against which a virtual screen of 64,480 small molecules was performed to identify candidate compounds that the motif specifically binds. The tandem mismatch was found to be specific for one compound, 2-amino-1,3-benzothiazole-6-carboxamide, which binds with moderate affinity but extends the motif to include the flanking A-U and G-C base pairs. The finding that affinity for the UU:GA mismatch is flanking sequence dependent emphasizes the importance of motif context and potentially increases the number of small non-canonical features within RNA that can be specifically targeted by small molecules.

  PublisherOA PDFDOI

• Correlating Drug–Target Residence Time and Post-antibiotic Effect: Insight into Target Vulnerability

  ACS Infectious Diseases · 2020 · 37 citations

  • Computer Science
  • Pharmacology
  • Biology

  ribosome and the PAE, indicating that the ribosome is a highly vulnerable drug target. The analysis of the residence time-PAE data for erythromycin, azithromycin, spiramycin, and telithromycin using a mechanistic pharmacokinetic-pharmacodynamic model that integrates drug-target kinetics into predictions of drug activity lead to the successful prediction of the cellular PAE for tylosin, which has the longest residence time (7.1 h) and PAE (5.8 h). Although the macrolide data support a connection between residence time, PAE, and bactericidality, many bactericidal β-lactam antibiotics do not give a PAE, illustrating the role of factors such as protein resynthesis in the expression of target vulnerability.

  PublisherOA PDFDOI

• 2-Amino-1,3-benzothiazole-6-carboxamide Preferentially Binds the Tandem Mismatch Motif r(UY:GA)

  Biochemistry · 2020 · 4 citations

  1st authorCorresponding
  • Chemistry
  • Stereochemistry
  • Crystallography

  RNA helices are often punctuated with non-Watson-Crick features that may be targeted by chemical compounds, but progress toward identifying such compounds has been slow. We embedded a tandem UU:GA mismatch motif (5'-UG-3':5'-AU-3') within an RNA hairpin stem to identify compounds that bind the motif specifically. The three-dimensional structure of the RNA hairpin and its interaction with a small molecule identified through virtual screening are presented. The G-A mismatch forms a sheared pair upon which the U-U base pair stacks. The hydrogen bond configuration of the U-U pair involves O2 of the U adjacent to the G and O4 of the U adjacent to the A. The G-A and U-U pairs are flanked by A-U and G-C base pairs, respectively, and the stability of the mismatch is greater than when the motif is within the context of other flanking base pairs or when the 5'-3' orientation of the G-A and U-U pairs is swapped. Residual dipolar coupling constants were used to generate an ensemble of structures against which a virtual screen of 64480 small molecules was performed. The tandem mismatch was found to be specific for one compound, 2-amino-1,3-benzothiazole-6-carboxamide, which binds with moderate affinity but extends the motif to include the flanking A-U and G-C base pairs. The finding that the affinity for the UU:GA mismatch is dependent on flanking sequence emphasizes the importance of the motif context and potentially increases the number of small noncanonical features within RNA that can be specifically targeted by small molecules.

  PublisherDOI

Recent grants

• NIH Grant F31GM090678

  NIH · $57k · 2012

Frequent coauthors

• Brant A. Inman

  Western University

  14 shared

• Wei Phin Tan

  13 shared

• Peter J. Tonge

  Stony Brook University

  12 shared

• Stephen G. Walker

  The University of Texas at Austin

  9 shared

• J. Schiebel

  Philipps University of Marburg

  9 shared

• Caroline Kisker

  University of Würzburg

  9 shared

• Yang Lü

  8 shared

• Steven C. Brousell

  Duke Medical Center

  8 shared

Education

• M.D., Medicine

  Stony Brook University School of Medicine

  2000

• B.S., Biochemistry and Cell Biology

  University of California, San Diego

  1996