Clinical Focus


  • Diagnostic Radiology
  • Genitourinary Cancers
  • Liver Neoplasms
  • Gastrointestinal Hemorrhage

Academic Appointments


  • Assistant Professor - University Medical Line, Radiology

Honors & Awards


  • ESGAR Top 20, European Society of Gastrointestinal and Abdominal Radiology (2021)
  • Resident Research Grant, Radiological Society of North America (RSNA) (2019)
  • President's Award: Resident in Radiology Award, American Roentgen Ray Society (ARRS) (2019)
  • Roentgen Resident Research Award, Radiological Society of North America (RSNA) (2019)
  • Goldberg-Reeder Resident Travel Grant, American College of Radiology (ACR) (2019)
  • Dox Foundation Travel Grant: Dar es Salaam, Tanzania, Doximity (2018)
  • Case of the Day 2nd Place Winner, Society of Abdominal Radiology (SAR) (2018)
  • Abstract Travel Award, Radiological Society of North America (RSNA) (2017)
  • Alexander R. Margulis GI Paper Presenter Award, Society of Abdominal Radiology (SAR) (2015)
  • Leo G. Rigler Award for Excellence in Radiological Sciences, UCLA David Geffen School of Medicine (2015)
  • Alpha Omega Alpha Honor Medical Society, Alpha Omega Alpha (AOA) (2014)
  • Carolyn L. Kuckein Student Research Fellowship, Alpha Omega Alpha (AOA) (2014)
  • Research Medical Student Grant, Radiological Society of North America (RSNA) (2014)
  • Summa cum laude, University of California (2011)

Boards, Advisory Committees, Professional Organizations


  • Member, ACR-RADS Steering Committee (2020 - Present)
  • Member, Society of Abdominal Radiology (SAR) Renal Cell Carcinoma Disease Focused Panel (2020 - Present)

Professional Education


  • Board Certification: American Board of Radiology, Diagnostic Radiology (2021)
  • Fellowship, UCLA David Geffen School of Medicine, Abdominal Imaging / Cross Sectional Interventional Radiology (2021)
  • Residency, Stanford University, Diagnostic Radiology (2020)
  • MD, UCLA David Geffen School of Medicine, Medicine (2015)

All Publications


  • Regulatory Frameworks for Development and Evaluation of Artificial Intelligence-Based Diagnostic Imaging Algorithms: Summary and Recommendations JOURNAL OF THE AMERICAN COLLEGE OF RADIOLOGY Larson, D. B., Harvey, H., Rubin, D. L., Irani, N., Tse, J. R., Langlotz, C. P. 2021; 18 (3): 413–24
  • Extravasation Volume at Computed Tomography Angiography Correlates With Bleeding Rate and Prognosis in Patients With Overt Gastrointestinal Bleeding. Investigative radiology Tse, J. R., Shen, J. n., Shah, R. n., Fleischmann, D. n., Kamaya, A. n. 2021

    Abstract

    Despite the identification of active extravasation on computed tomography angiography (CTA) in patients with overt gastrointestinal bleeding (GIB), a large proportion do not have active bleeding or require hemostatic therapy at endoscopy, catheter angiography, or surgery. The objective of our proof-of-concept study was to improve triage of patients with GIB by correlating extravasation volume of first-pass CTA with bleeding rate and clinical outcomes.All patients who presented with overt GIB and active extravasation on CTA from January 2014 to July 2019 were reviewed in this retrospective, institutional review board-approved and Health Insurance Portability and Accountability Act-compliant study. Extravasation volume was assessed using 3-dimensional software and correlated with hemostatic therapy (primary endpoint) and with intraprocedural bleeding, blood transfusions, and mortality as secondary endpoints using logistic regression models (P < 0.0125 indicating statistical significance). Odds ratios were used to determine the effect size of a threshold extravasation volume. Quantitative data (extravasation volume, aorta attenuation, extravasation attenuation and time) were input into a mathematical model to calculate bleeding rate.Fifty consecutive patients including 6 (12%) upper, 18 (36%) small bowel, and 26 (52%) lower GIB met inclusion criteria. Forty-two underwent catheter angiography, endoscopy, or surgery; 16 had intraprocedural active bleeding, and 24 required hemostatic therapy. Higher extravasation volumes correlated with hemostatic therapy (P = 0.007), intraprocedural active bleeding (P = 0.003), and massive transfusion (P = 0.0001), but not mortality (P = 0.936). Using a threshold volume of 0.80 mL or greater, the odds ratio of hemostatic therapy was 8.1 (95% confidence interval, 2.1-26), active bleeding was 11.8 (2.6-45), and massive transfusion was 18 (2.3-65). With mathematical modeling, extravasation volume had a direct and linear relationship with bleeding rate, and the lowest calculated detectable bleeding rate with CTA was less than 0.1 mL/min.Larger extravasation volumes correlate with higher bleeding rates and may identify patients who require hemostatic therapy, have intraprocedural bleeding, and require blood transfusions. Current CTAs can detect bleeding rates less than 0.1 mL/min.

    View details for DOI 10.1097/RLI.0000000000000753

    View details for PubMedID 33449577

  • Prevalence of Malignancy and Histopathologic Association of Bosniak Classification, Version 2019 Class III and IV Cystic Renal Masses. The Journal of urology Tse, J. R., Shen, L., Shen, J., Yoon, L., Kamaya, A. 2020: 101097JU0000000000001438

    Abstract

    PURPOSE: Bosniak Classification, version 2019 (v2019) describes two types of class III and IV masses each: 1) thick, wall/septa ≥4 mm (III-WS), 2) obtuse protrusion ≤3 mm (III-OP), 3) obtuse protrusion ≥4 mm (IV-OP), and 4) acute protrusion of any size (IV-AP). The purposes were to determine the prevalence of malignancy and histopathologic features of class III and IV masses and subclasses.MATERIALS AND METHODS: In this IRB-approved and HIPAA-compliant study, three fellowship-trained abdominal radiologists (R1-3) reviewed cystic renal masses that had tissue pathology and pre-operative renal mass protocol CT or MRI. Classes based on v2019 and prior classification systems were retrospectively re-assigned and associated with malignancy, aggressive histologic features (necrosis or high Fuhrman grade), and radiologic progression following resection.RESULTS: The final sample included 79 masses (59 malignant, 20 benign) from 74 patients. Based on v2019, prevalence of malignancy ranged from 56-61% (mean 60%) for class III and 83-83% (mean 83%) for class IV (p=0.036, 0.013, 0.036 for R1-3). Prevalence of malignancy within subclasses were: III-WS (47-53%); III-OP (71-85%); IV-OP (75-87%); IV-AP (87-95%; p=0.029, 0.001, 0.005). All readers were more likely to classify malignancies with aggressive histologic features as class IV (88-100%) rather than class III (0-12%; p=0.012, <0.001, 0.002), corresponding to a negative predictive value of 96-100%. Following treatment (mean follow-up length 1210 days), one patient developed metastases.CONCLUSIONS: Bosniak Classification, version 2019 can help risk stratification of class III-IV masses by identifying those likely to be malignant and have aggressive histologic features.

    View details for DOI 10.1097/JU.0000000000001438

    View details for PubMedID 33085925

  • Bosniak Classification Version 2019 of Cystic Renal Masses Assessed With MRI. AJR. American journal of roentgenology Tse, J. R., Shen, J. n., Yoon, L. n., Kamaya, A. n. 2020: 1–7

    Abstract

    OBJECTIVE. The purpose of this study was to determine how use of Bosniak classification version 2019 affects categorization and overall accuracy of MRI evaluation of cystic renal masses with tissue pathologic analysis as the reference standard. MATERIALS AND METHODS. MR images of 50 consecutively registered patients with tissue pathologic results from 2005 to 2019 were retrospectively reviewed by two abdominal radiologists. Each radiologist independently assigned a category based on the original and Bosniak classification version 2019 systems. Interreader agreements (kappa statistic) for both were calculated, and consensus reading was performed. Tissue pathologic analysis was used as the reference standard to determine whether a lesion was benign or renal cell carcinoma. RESULTS. Fifty-nine cystic renal masses were characterized as 38 renal cell carcinomas and 21 benign lesions on the basis of the results of tissue pathologic analysis. By consensus, according to the original Bosniak criteria, the renal masses were classified into three category I, five category II, four category IIF, 25 category III, and 22 category IV lesions. By consensus, according to the version 2019 criteria, the renal masses were classified into three category I, two category II, 12 category IIF, 18 category III, and 24 category IV lesions. Overall sensitivity and specificity for identifying renal cell carcinoma were 95% and 81%, respectively, with the original classification system and 100% and 86%, respectively, with version 2019. Weighted interreader agreement was moderate for both the original system (κ = 0.57) and version 2019 (κ = 0.55). CONCLUSION. Use of Bosniak classification version 2019 system improves sensitivity and specificity for malignancy among cystic renal masses characterized with MRI. Most lesions that changed categories were reclassified as Bosniak category IIF.

    View details for DOI 10.2214/AJR.19.22740

    View details for PubMedID 32515608

  • Bosniak Classification of Cystic Renal Masses Version 2019: Comparison of Categorization using CT and MRI. AJR. American journal of roentgenology Tse, J. R., Shen, J. n., Shen, L. n., Yoon, L. n., Kamaya, A. n. 2020

    Abstract

    Please see the Author Video associated with this article. Background: Bosniak Classification, version 2019 recently proposed refinements for cystic renal mass characterization and now formally incorporates MRI, which may improve concordance with CT. Purpose: To compare concordance of CT and MRI in evaluation of cystic renal masses using Bosniak Classification, version 2019. Materials and Methods: In this IRB-approved and HIPAA compliant study, three abdominal radiologists (R1-R3) retrospectively reviewed 68 consecutive cystic renal masses from 45 patients assessed with both CT and MR renal mass protocols within a year between 2005-2019. CT and MRI were reviewed independently and in separate sessions, using both the original and version 2019 Bosniak Classification systems. Results: Using Bosniak Classification, version 2019, cystic renal masses were classified into 12 category I, 19 category II, 13 category IIF, 4 category III, and 20 category IV by CT and 8 category I, 15 category II, 23 category IIF, 9 category III, and 13 category IV by MRI. Among individual features, MRI depicted more septa (p<0.001, p=0.046, p=0.005 for R1-R3; McNemar's test) for all radiologists, though both CT and MRI showed a similar number of protrusions (p=0.823, 1.0, 0.302) and maximal septa/wall thickness (p=1.0, 1.0, 0.145). Of discordant cases with version 2019, MRI led to the higher category in 12 masses. Reason for upgrade was most commonly due to protrusions identified only on MRI (n=4), increased number of septa (n=3), and a new category of heterogeneously T1-hyperintense (n=3). Neither modality was more likely to lead to a category change for both version 2019 (p=0.502; McNemar's test) and the original Bosniak classification system (p=0.823). Overall inter-rater agreement was substantial for both CT (κ=0.745) and MRI (κ=0.655) using version 2019 and was slightly higher than that of the original system (CT κ=0.707; MRI κ=0.623). Conclusion: CT and MRI were concordant in the majority of cases using Bosniak Classification, version 2019 and category changes by modality were not statistically significant. Inter-rater agreements were substantial for both CT and MRI. Clinical Impact: Bosniak Classification, version 2019 applied to cystic renal masses has substantial inter-rater agreement and does not lead to systematic category upgrades with either CT or MRI.

    View details for DOI 10.2214/AJR.20.23656

    View details for PubMedID 32755181

  • Qualitative and Quantitative Gadoxetic Acid-enhanced MR Imaging Helps Subtype Hepatocellular Adenomas RADIOLOGY Tse, J. R., Naini, B. V., Lu, D. S., Raman, S. S. 2016; 279 (1): 118-127

    Abstract

    To determine which clinical variables and gadoxetic acid disodium (Gd-EOB-DTPA)-enhanced magnetic resonance (MR) imaging features are associated with histologically proved hepatocellular adenoma (HCA) genotypic subtypes.In this institutional review board-approved and Health Insurance Portability and Accountability Act-compliant study, clinical information and MR images of 49 histologically proved HCAs from January 2002 to December 2013 (21 patients; mean age, 39 years; age range, 15-59 years) were retrospectively reviewed by two radiologists. Qualitative and quantitative imaging features, including the signal intensity ratio relative to liver in each phase, were studied. HCA tissues were stained with subtype-specific markers and subclassified by a pathologist. Clinical and imaging data were correlated with pathologic findings and compared by using Fisher exact or t test, with a Bonferroni correction for multiple comparisons.Forty-nine HCAs were subclassified into 14 inflammatory, 20 hepatocyte nuclear factor (HNF)-1α-mutated, one β-catenin-activated, and 14 unclassified lesions. Intralesional steatosis was exclusively seen in HNF-1α-mutated lesions. Marked hyperintensity on T2-weighted images was seen in 12 of 14 (86%) inflammatory lesions compared with four of 21 (19%) HNF-1α-mutated, seven of 14 (50%) unclassified, and zero of one (0%) β-catenin-activated lesion. Two large lesions (one β-catenin-activated and one unclassified) transformed into hepatocellular carcinomas and were the only lesions to enhance with marked heterogeneity. In the hepatobiliary phase, all HCA subtypes were hypoenhancing compared with surrounding liver parenchyma, and they reached their nadir signal intensity by 10 minutes after the administration of contrast material before plateauing. HNF-1α-mutated lesions had the lowest lesion signal intensity ratio of 0.47 ± 0.09, compared with 0.73 ± 0.18 for inflammatory lesions (P = .0004), 0.82 for the β-catenin-activated lesion, and 0.73 ± 0.06 for the unclassified lesion (P = .00002).In this study, all HCA subtypes were hypoenhancing at Gd-EOB-DTPA-enhanced MR imaging in the hepatobiliary phase and reached their nadir signal intensity at 10 minutes. HNF-1α-mutated lesions could be distinguished from other subtypes by having the lowest lesion signal intensity ratio.

    View details for DOI 10.1148/radiol.2015142449

    View details for Web of Science ID 000378709700011

    View details for PubMedID 26505921

  • Preparation of hydrogel substrates with tunable mechanical properties. Current protocols in cell biology Tse, J. R., Engler, A. J. 2010; Chapter 10: Unit 10 16-?

    Abstract

    The modulus of elasticity of the extracellular matrix (ECM), often referred to in a biological context as "stiffness," naturally varies within the body, e.g., hard bones and soft tissue. Moreover, it has been found to have a profound effect on the behavior of anchorage-dependent cells. The fabrication of matrix substrates with a defined modulus of elasticity can be a useful technique to study the interactions of cells with their biophysical microenvironment. Matrix substrates composed of polyacrylamide hydrogels have an easily quantifiable elasticity that can be changed by adjusting the relative concentrations of its monomer, acrylamide, and cross-linker, bis-acrylamide. In this unit, we detail a protocol for the fabrication of statically compliant and radial-gradient polyacrylamide hydrogels, as well as the functionalization of these hydrogels with ECM proteins for cell culture. Included as well are suggestions to optimize this protocol to the choice of cell type or stiffness with a table of relative bis-acrylamide and acrylamide concentrations and expected elasticity after polymerization.

    View details for DOI 10.1002/0471143030.cb1016s47

    View details for PubMedID 20521229

  • Cystic artery velocity as a predictor of acute cholecystitis. Abdominal radiology (New York) Perez, M. G., Tse, J. R., Bird, K. N., Liang, T., Brooke Jeffrey, R., Kamaya, A. 2021

    Abstract

    To evaluate angle-corrected peak systolic cystic artery velocity (CAv) as a predictor of acute cholecystitis among patients presenting to the emergency department (ED) with right upper quadrant (RUQ) pain.In this IRB-approved and retrospective study, CAv was evaluated in 73 patients, 43 who underwent definitive treatment with cholecystectomy or percutaneous cholecystostomy and 30 control patients without clinical suspicion for cholecystitis. In addition to CAv, the following were reviewed by 3 radiologists: CBD diameter, cholelithiasis, impacted stone in the neck, sludge, gallbladder wall thickness > 3 mm, gallbladder transverse dimension ≥ 4 cm, longitudinal dimension ≥ 8 cm, tensile gallbladder fundus sign, pericholecystic fluid, pericholecystic echogenic fat, and sonographic Murphy sign.Of the 43 patients who underwent definitive treatment, 25 had acute cholecystitis (34%) and 18 (25%) had chronic cholecystitis. Average CAv measurements were 50 ± 16 cm/s (acute), 28 ± 8 cm/s (chronic), and 22 ± 8 cm/s (control; p < 0.0001). In univariate analysis, among patients who underwent definitive therapy, CAv ≥ 40 cm/s, gallbladder wall thickness, stone impaction, GB long dimension ≥ 8 cm, and elevated WBC were associated with acute cholecystitis (p < 0.05). In multivariate analysis, CAv ≥ 40 cm/s was the only statistically significant variable (p = 0.016). CAv ≥ 40 cm/s alone had a PPV of 94.7% and overall accuracy of 81.4% in diagnosing acute cholecystitis.CAv ≥ 40 cm/s is highly associated with acute cholecystitis in patients presenting to the ED with RUQ pain.

    View details for DOI 10.1007/s00261-021-03020-z

    View details for PubMedID 34216245

  • Does measurement of the hepatic artery velocity improve the sonographic diagnosis of cholangitis? Abdominal radiology (New York) Tse, J. R., Liang, T. n., Jeffrey, R. B., Kamaya, A. n. 2019

    Abstract

    To determine the frequency of elevated peak systolic proper hepatic artery velocity (HAV) in patients with acute cholangitis and to determine the diagnostic performance of this metric relative to existing criteria.Between 9/2016 and 11/2017, 107 patients clinically suspected to have cholangitis were referred for an abdominal ultrasound. Of these, 56 patients had HAV measurements and were included in the final analysis. Clinical and imaging features, including HAV, HAV resistive index (RI), portal vein velocity (PVV), biliary dilation, and presence of an obstructive etiology were extracted. The diagnostic performance of HAV was compared to the existing available clinical criteria (Charcot's triad and 2018 Tokyo Guidelines). Elevated HAV was defined as HAV > 100 cm/s. Presence of cholangitis was determined by the discharge summary following medical workup and admission or observation.32% had cholangitis while 68% did not. Average HAV for patients with cholangitis was 152 ± 54 cm/s versus 91 ± 44 cm/s for those without (p < 0.0001; t test). The HAV was elevated in 83% of patients with cholangitis. When considered in isolation, an elevated HAV had a high negative predictive value (90%), was more accurate (77%; 95% confidence interval 64-87%) than Charcot's triad (73%; 60-83%), and had similar accuracy compared to 2018 Tokyo Guidelines (79%; 66-88%). Substitution of conventional imaging criteria with elevated HAV in the 2018 Tokyo Guidelines yielded the highest overall accuracy of 84% (72-92%).HAV is elevated in the majority of patients with cholangitis. Substitution of an elevated HAV for conventional sonographic criteria is more accurate than existing clinical criteria in identifying patients with cholangitis.

    View details for DOI 10.1007/s00261-019-02284-w

    View details for PubMedID 31673717

  • Performance of Hepatic Artery Velocity in Evaluation of Causes of Markedly Elevated Liver Tests. Ultrasound in medicine & biology Tse, J. R., Jeffrey, R. B., Kamaya, A. 2018

    Abstract

    The purpose of this study was to assess the utility of peak systolic proper hepatic artery velocity (HAV) in differentiating causes of severely elevated liver function tests. HAV, hepatic artery resistive index and portal vein velocity of 41 patients with severely elevated liver function tests were evaluated. In 19 patients (46%), the causes were structural (e.g., cholecystitis, cholangitis), whereas in 22 patients (54%) the causes were non-structural (e.g., rhabdomyolysis, drug-induced liver injury). The average HAV for structural causes was 138 ± 68 cm/s, and for non-structural causes, 65 ± 29 cm/s (p < 0.0001). An HAV >100 cm/s was correlated with structural causes (p = 0.0001). With respect to diagnostic performance, this threshold was 79% sensitive and 86% specific, with a high positive likelihood ratio (5.8) and low negative likelihood ratio (0.24). The resistive index and portal vein velocity were not statistically different. In patients with severely elevated liver function tests, an HAV >100 cm/s can help distinguish structural from non-structural causes, which may guide management while awaiting definitive laboratory tests.

    View details for PubMedID 30143340

  • Bayonet sign in dysphagia lusoria. Abdominal radiology (New York) Tse, J. R., Desser, T. S. 2018

    View details for PubMedID 29796846

  • The utility of hepatic artery velocity in diagnosing patients with acute cholecystitis. Abdominal radiology (New York) Loehfelm, T. W., Tse, J. R., Jeffrey, R. B., Kamaya, A. n. 2017

    Abstract

    To test the diagnostic performance of elevated peak systolic hepatic arterial velocity (HAv) in the diagnosis of acute cholecystitis.229 patients with an ultrasound (US) performed for right upper quadrant (RUQ) pain were retrospectively reviewed. 35 had cholecystectomy within 10 days of ultrasound and were included as test subjects. 47 had normal US and serology and were included as controls. Each test patient US was reviewed for the presence of gallstones, gallbladder distention, sludge, echogenic pericholecystic fat, pericholecystic fluid, gallbladder wall thickening, gallbladder wall hyperemia, and reported sonographic Murphy sign. Demographic, clinical, and hepatic artery parameters at time of original imaging were recorded. Acute cholecystitis at pathology was the primary outcome variable.21 patients had acute cholecystitis and 14 had chronic cholecystitis by pathology. For patients who went to cholecystectomy, HAv ≥100 cm/s to diagnose acute cholecystitis was more accurate (69%) than the original radiology report (63%), the presence of gallstones (51%), and sonographic Murphy sign (50%). Statistically significant predictors of acute cholecystitis included HAv ≥100 cm/s (p = 0.008), older age (p = 0.012), and elevated WBC (p = 0.002), while gallstones (p = 0.077), hepatic artery resistive index (HARI) (p = 0.199), gallbladder distension (p = 0.252), sludge (p = 0.147), echogenic fat (p = 0.184), pericholecystic fluid (p = 0.357), wall thickening (p = 0.434), hyperemia (p = 0.999), and sonographic Murphy sign (p = 0.765) were not significantly correlated with acute cholecystitis compared to chronic cholecystitis.HAv ≥100 cm/s is a useful objective parameter that may improve the performance of US in the diagnosis of acute cholecystitis.

    View details for PubMedID 28840272

  • Effects of vocal fold epithelium removal on vibration in an excised human larynx model JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA Tse, J. R., Zhang, Z., Long, J. L. 2015; 138 (1): EL60-EL64

    Abstract

    This study investigated the impact of selective epithelial injury on phonation in an excised human larynx apparatus. With intact epithelium, the vocal folds exhibited a symmetrical vibration pattern with complete glottal closure during vibration. The epithelium was then enzymatically removed from one, then both vocal folds, which led to left-right asymmetric vibration and a decreased closed quotient. Although the mechanisms underlying these vibratory changes are unclear, these results demonstrate that some component of an intact surface layer may play an important role in achieving normal symmetric vibration and glottal closure.

    View details for DOI 10.1121/1.4922765

    View details for Web of Science ID 000358929000011

    View details for PubMedID 26233062

  • Rituximab: an emerging treatment for recurrent diffuse alveolar hemorrhage in systemic lupus erythematosus LUPUS Tse, J. R., Schwab, K. E., McMahon, M., Simon, W. 2015; 24 (7): 756-759

    Abstract

    Diffuse alveolar hemorrhage (DAH) is a rare manifestation of systemic lupus erythematosus (SLE) and is associated with high mortality rates. Treatment typically consists of aggressive immunosuppression with pulse-dose steroids, cyclophosphamide, and plasma exchange therapy. Mortality rates remain high despite use of multiple medical therapies. We present a case of recurrent DAH in a 52-year-old female with SLE after a deceased donor renal transplant who was successfully treated with rituximab. Our report highlights the pathophysiologic importance of B-cell-mediated immunosuppression in SLE-associated DAH and suggests that rituximab may represent a viable alternative to cyclophosphamide in the treatment of this disease. We also review eight other reported cases of rituximab use in SLE-associated DAH.

    View details for DOI 10.1177/0961203314564235

    View details for Web of Science ID 000354558900014

    View details for PubMedID 25527066

  • Microstructure Characterization of a Decellularized Vocal Fold Scaffold for Laryngeal Tissue Engineering LARYNGOSCOPE Tse, J. R., Long, J. L. 2014; 124 (8): E326-E331

    Abstract

    One potential treatment for vocal fold injury or neoplasia is to replace the entire vocal fold with a tissue-engineered scaffold. This scaffold should ideally have similar mechanical properties and extracellular matrix composition as the native vocal fold. As one approach toward this goal, we decellularized human vocal folds and characterized their mechanical properties and extracellular matrix microstructure.Basic science investigation.Human vocal folds were dissected from the laryngeal framework and treated with sodium dodecyl sulfate (SDS) to remove all cells. Mechanical properties were measured by indentation before and after SDS treatment. The extracellular matrix components of collagen, laminin, elastin, and hyaluronic acid were also characterized before and after decellularization using histology and immunofluorescence.After 4 days of SDS treatment, we obtained a scaffold that retained the original geometry of the vocal fold but was devoid of cells. The elastic modulus of the vocal folds did not change significantly before and after decellularization. Upon qualitative inspection, the decellularized vocal folds retained the original collagen, elastin, and laminin content and orientation but lost the original hyaluronic acid.Vocal folds can be decellularized using SDS without adversely affecting its mechanical stiffness and fibrous extracellular matrix. This preliminary study demonstrates the potential of a decellularized scaffold to serve as a tissue-engineered construct for vocal fold replacement.

    View details for DOI 10.1002/lary.24605

    View details for Web of Science ID 000339482100005

    View details for PubMedID 24448829

  • Pancytopenia secondary to cytomegalovirus reactivation. BMJ case reports Tse, J. R., Ng, G. X. 2014; 2014

    Abstract

    A 64-year-old woman with a 1-year history of microscopic polyangiitis developed isolated pancytopenia secondary to cytomegalovirus (CMV) reactivation. The patient was originally admitted to the medical service for the management of a rapidly progressing 10 cm ulcer on her left lower extremity. Prior to admission, the patient had been on several immunosuppressive agents for the treatment of microscopic polyangiitis, including prednisone, azathioprine, cyclophosphamide and rituximab. Her hospital course was notable for pancytopenia and after a very thorough diagnostic work-up, the aetiology was found to be secondary to CMV reactivation. This was confirmed by blood analysis that revealed a highly elevated CMV level at 899 100 copies/mL by quantitative PCR. The patient was promptly treated with intravenous ganciclovir for a total course of 14 days before transitioning to an oral regimen. She had a pronounced response to the anti-CMV therapy with complete recovery of her white cell count, haemoglobin and platelet count to baseline.

    View details for DOI 10.1136/bcr-2013-201857

    View details for PubMedID 24419641

  • Stiffness Gradients Mimicking In Vivo Tissue Variation Regulate Mesenchymal Stem Cell Fate PLOS ONE Tse, J. R., Engler, A. J. 2011; 6 (1)

    Abstract

    Mesenchymal stem cell (MSC) differentiation is regulated in part by tissue stiffness, yet MSCs can often encounter stiffness gradients within tissues caused by pathological, e.g., myocardial infarction ∼8.7±1.5 kPa/mm, or normal tissue variation, e.g., myocardium ∼0.6±0.9 kPa/mm; since migration predominantly occurs through physiological rather than pathological gradients, it is not clear whether MSC differentiate or migrate first. MSCs cultured up to 21 days on a hydrogel containing a physiological gradient of 1.0±0.1 kPa/mm undergo directed migration, or durotaxis, up stiffness gradients rather than remain stationary. Temporal assessment of morphology and differentiation markers indicates that MSCs migrate to stiffer matrix and then differentiate into a more contractile myogenic phenotype. In those cells migrating from soft to stiff regions however, phenotype is not completely determined by the stiff hydrogel as some cells retain expression of a neural marker. These data may indicate that stiffness variation, not just stiffness alone, can be an important regulator of MSC behavior.

    View details for DOI 10.1371/journal.pone.0015978

    View details for Web of Science ID 000286511200030

    View details for PubMedID 21246050