Shiro Urayama

Prof. Shiro Urayama

UC Davis Medical Center, Sacramento, CA 95817, USA

Research Focus & Metrics

Academic Career Length

17Years (2010-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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8 February 2010 in Rapid Communications in Mass Spectrometry
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Journal Article
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Shiro UrayamaShiro Urayama
Shiro Urayama
WZWei Zou
Wei Zou
KBKindra Brooks
Kindra Brooks
Vladimir TolstikovVladimir Tolstikov
Vladimir Tolstikov

1 November 2018 in Gastroenterology
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Journal Article
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SWSachin Wani
Sachin Wani
RKRajesh N. Keswani
Rajesh N. Keswani
SHSamuel Han
Samuel Han
EAEva M. Aagaard
Eva M. Aagaard
MHMatthew Hall
Matthew Hall
DEDayna Early
Dayna Early
It is unclear whether participation in competency-based fellowship programs for endoscopic ultrasound (EUS) and endoscopic retrograde cholangiopancreatography (ERCP) results in high-quality care in independent practice. We measured quality indicator (QI) adherence during the first year of independent practice among physicians who completed endoscopic training with a systematic assessment of competence. We performed a prospective multicenter cohort study of invited participants from 62 training programs. In phase 1, 24 advanced endoscopy trainees (AETs), from 20 programs, were assessed using a validated competence assessment tool. We used a comprehensive data collection and reporting system to create learning curves using cumulative sum analysis that were shared with AETs and trainers quarterly. In phase 2, participating AETs entered data into a database pertaining to every EUS and ERCP examination during their first year of independent practice, anchored by key QIs. By the end of training, most AETs had achieved overall technical competence (EUS 91.7%, ERCP 73.9%) and cognitive competence (EUS 91.7%, ERCP 94.1%). In phase 2 of the study, 22 AETs (91.6%) participated and completed a median of 136 EUS examinations per AET and 116 ERCP examinations per AET. Most AETs met the performance thresholds for QIs in EUS (including 94.4% diagnostic rate of adequate samples and 83.8% diagnostic yield of malignancy in pancreatic masses) and ERCP (94.9% overall cannulation rate). In this prospective multicenter study, we found that although competence cannot be confirmed for all AETs at the end of training, most meet QI thresholds for EUS and ERCP at the end of their first year of independent practice. This finding affirms the effectiveness of training programs. Clinicaltrials.gov ID NCT02509416.

15 September 2020 in Nature Communications
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MZMa Zhao
Ma Zhao
JLJin Li
Jin Li
KLKai Lin
Kai Lin
MRMythili Ramachandran
Mythili Ramachandran
DZDalin Zhang
Dalin Zhang
PLPeiyuan Li
Peiyuan Li
Integration of the unique advantages of the fields of drug discovery and drug delivery is invaluable for the advancement of drug development. Here we propose a self-delivering one-component new-chemical-entity nanomedicine (ONN) strategy to improve cancer therapy through incorporation of the self-assembly principle into drug design. A lysosomotropic detergent (MSDH) and an autophagy inhibitor (Lys05) are hybridised to develop bisaminoquinoline derivatives that can intrinsically form nanoassemblies. The selected BAQ12 and BAQ13 ONNs are highly effective in inducing lysosomal disruption, lysosomal dysfunction and autophagy blockade and exhibit 30-fold higher antiproliferative activity than hydroxychloroquine used in clinical trials. These single-drug nanoparticles demonstrate excellent pharmacokinetic and toxicological profiles and dramatic antitumour efficacy in vivo. In addition, they are able to encapsulate and deliver additional drugs to tumour sites and are thus promising agents for autophagy inhibition-based combination therapy. Given their transdisciplinary advantages, these BAQ ONNs have enormous potential to improve cancer therapy.

1 January 2015 in World Journal of Gastroenterology
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Journal Article
Open access
Shiro UrayamaShiro Urayama
Shiro Urayama
Pancreatic ductal adenocarcinoma (PDAC) is the fourth and fifth leading cause of cancer death for each gender in developed countries. With lack of effective treatment and screening scheme available for the general population, the mortality rate is expected to increase over the next several decades in contrast to the other major malignancies such as lung, breast, prostate and colorectal cancers. Endoscopic ultrasound, with its highest level of detection capacity of smaller pancreatic lesions, is the commonly employed and preferred clinical imaging-based PDAC detection method. Various molecular biomarkers have been investigated for characterization of the disease, but none are shown to be useful or validated for clinical utilization for early detection. As seen from studies of a small subset of familial or genetically high-risk PDAC groups, the higher yield and utility of imaging-based screening methods are demonstrated for these groups. Multiple recent studies on the unique cancer metabolism including PDAC, demonstrate the potential for utility of the metabolites as the discriminant markers for this disease. In order to generate an early PDAC detection screening strategy available for a wider population, we propose to expand the population of higher risk PDAC group with combination clinical and metabolomics parameters.

31 July 2019 in Clinical Endoscopy
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AEArmen Eskandari
Armen Eskandari
PKPatrick Koo
Patrick Koo
HBHeejung Bang
Heejung Bang
DGDorina Gui
Dorina Gui
Shiro UrayamaShiro Urayama
Shiro Urayama
To compare the performance of latest commercially available endoscopic ultrasound biopsy needles. Six latest commercially available needles were tested on a freshly harvested bovine liver; the tested needles included three 19 G, one 20 G, and two 22 G needles. Five biopsies were performed per needle with 10 mL of wet suction. The primary outcome was the number of complete portal tracts (CPTs) per needle aspirate. The secondary outcomes were the mean specimen length and mean fragment length. Analysis of variance and Tukey's test were applied. All 19 G needles and the 20 G needle yielded similar mean CPTs and were superior to the SharkCore 22 G needle (p<0.001 adjusted for multiplicity). There was no statistically significant difference in total specimen length among the three 19 G needles and the 20 G needle tested. The two 22 G needles performed similarly with respect to the number of CPTs, mean fragment length, and mean specimen length (adjusted p=0.07, p=0.59, and p=0.10, respectively). The specimen adequacy was similar among the 3 latest commercially available 19 G needles. The endoscopist may choose a larger-bore needle based on availability without concerns of specimen adequacy. Further studies are needed to assess the ease of needle use in various anatomical locations and to confirm the optimal needle design.

28 November 2022 in Cancer Research Communications
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TTTed W. Toal
Ted W. Toal
AEAna P. Estrada-Florez
Ana P. Estrada-Florez
GPGuadalupe M. Polanco-Echeverry
Guadalupe M. Polanco-Echeverry
RSRuta M. Sahasrabudhe
Ruta M. Sahasrabudhe
PLPaul C. Lott
Paul C. Lott
LCLuis Carvajal-Carmona
Luis Carvajal-Carmona
Gastric cancer is a leading cause of cancer mortality and health disparities in Latinos. We evaluated gastric intratumoral heterogeneity using multiregional sequencing of >700 cancer genes in 115 tumor biopsies from 32 patients, 29 who were Latinos. Analyses focused on comparisons with The Cancer Genome Atlas (TCGA) and on mutation clonality, druggability, and signatures. We found that only approximately 30% of all mutations were clonal and that only 61% of the known TCGA gastric cancer drivers harbored clonal mutations. Multiple clonal mutations were found in new candidate gastric cancer drivers such as EYS, FAT4, PCDHA1, RAD50, EXO1, RECQL4, and FSIP2. The genomically stable (GS) molecular subtype, which has the worse prognosis, was identified in 48% of our Latino patients, a fraction that was >2.3-fold higher than in TCGA Asian and White patients. Only a third of all tumors harbored clonal pathogenic mutations in druggable genes, with most (93%) GS tumors lacking actionable clonal mutations. Mutation signature analyses revealed that, in microsatellite-stable (MSS) tumors, DNA repair mutations were common for both tumor initiation and progression, while tobacco, POLE, and inflammation signatures likely initiate carcinogenesis. MSS tumor progression was likely driven by aging- and aflatoxin-associated mutations, as these latter changes were usually nonclonal. In microsatellite-unstable tumors, nonclonal tobacco-associated mutations were common. Our study, therefore, contributed to advancing gastric cancer molecular diagnostics and suggests clonal status is important to understanding gastric tumorigenesis. Our findings of a higher frequency of a poor prognosis associated molecular subtype in Latinos and a possible new aflatoxin gastric cancer etiology also advance cancer disparities research.Significance: Our study contributes to advancing our knowledge of gastric carcinogenesis, diagnostics, and cancer health disparities.