About

James (Jay) E. Sayre is an assistant professor of cooperative extension at UC Davis in the department of agricultural and resource economics (ARE). His main fields of interest are agricultural economics and international trade, with additional work touching upon development and remote sensing. A connecting theme in his research is studying the determinants of why regions choose to produce certain agricultural commodities and the aggregate consequences of those decisions. He completed his graduate studies at UC Berkeley in agricultural and resource economics. His research includes developing models to better understand the gains from trade, especially considering features like low price elasticities and natural resource dispersion across countries. He has also investigated the spatial distribution of agricultural production, emphasizing the role of supply chains in explaining clustering patterns, particularly in Mexico. His work on remote sensing aims to predict crop yields at large scales using satellite imagery and machine learning techniques. Additionally, Sayre is involved in extension and outreach activities focused on the economics of food supply chains, aiming to improve understanding of policies, inefficiencies, and responses to shocks affecting agricultural distribution networks. His efforts include developing educational programs for growers, supply chain intermediaries, policymakers, and academics, with recent publications addressing California's agricultural emissions, labor dynamics, and trade policies.

Research topics

• Environmental science
• Biology
• Agronomy
• Ecology
• Soil science
• Chemistry

Selected publications

• Hepatobiliary phase abbreviated MRI for secondary surveillance after microwave ablation of HCC

  CVIR Oncology · 2025-06-23

  articleOpen access

  Abstract Purpose To compare the diagnostic performance of an abbreviated MRI (AMRI) protocol consisting of hepatobiliary phase (HBP) and T2-weighted sequences versus complete-protocol MRI, for secondary surveillance in patients with hepatocellular carcinoma (HCC) after microwave ablation (MWA). Methods This retrospective cohort study included 43 HCC patients who underwent MWA between 2017 and 2019, comprising 27 consecutive patients with recurrence and 16 randomly selected patients without recurrence (to increase the proportion of negative MRI exams presented to readers), resulting in a total of 215 complete-protocol gadoxetic acid-enhanced surveillance MRI exams. Three blinded radiologists independently reviewed AMRI exams, which consisted of only HBP and T2-weighted sequences for each surveillance MRI, with access to pre- and post-complete-protocol MRIs for comparison. Diagnostic performance of AMRI was compared with the results from complete MRI protocol. Results Inter-reader agreement was excellent ( κ = 0.91). Overall diagnostic performance per-patient and per-AMRI was as follows: sensitivity (SEN), specificity (SPE), and negative predictive value (NPV) of 86.4% (95%CI: 77.3–92.2), 100% (95.5–100), and 88.1% (79.8–93.2) for per-patient, and 87.5% (81.1–91.9), 97.6% (95–98.9) and 93.3% (89.7–95.7) for per-AMRI. Per-patient evaluation in the nonlocal-R subcohort showed SEN, SPE, and NPV of 86.6% (75.8–93.1), 100% (84.5–100), and 72.4% (54.3–85.3), compared with 85.7% (65.3–95), 100% (93.9–100) and 95.2% (86.9–98.7) for local-R subcohort, respectively. Conclusion An AMRI protocol consisting of HBP and T2-weighted sequences has high SEN and NPV for detecting recurrent HCC and may be an acceptable secondary surveillance method for HCC patients following MWA, which may lead to decreased scan times and associated costs.

  PublisherOA PDFDOI

• Predictors of Hemorrhage and Re-Intervention in Renal Angiomyolipoma Following Transcatheter Arterial Embolization

  Journal of Clinical Medicine · 2025-10-02 · 1 citations

  articleOpen access

  Purpose: Renal angiomyolipomas (AMLs) are benign renal neoplasms that may lead to spontaneous hemorrhage. Transcatheter arterial embolization (TAE) is a nephron-sparing treatment option, yet data on predictors of hemorrhage and re-intervention remain limited. This study evaluates clinical and radiologic outcomes of TAE and identifies predictors of hemorrhage and repeat embolization. Materials and Methods: A retrospective review of 66 patients (69 AMLs) undergoing TAE between 2010 and 2024 was conducted. Clinical, radiological, and procedural variables were analyzed. Tumor size, vascularity, and aneurysmal features were assessed pre- and post-embolization. Logistic regression models identified predictors of hemorrhage and repeat TAE. Results: Pre-treatment tumor diameter was the only significant predictor of hemorrhage (p = 0.011), with a threshold of 6.8 cm yielding 84.6% sensitivity and 71.3% specificity. All hemorrhagic tumors measured ≥4 cm. Post-embolization tumor volume predicted repeat TAE (p = 0.001), with a 248 mL cutoff. TAE significantly reduced tumor diameter (−33.5%) and volume (−60%) (p < 0.001). Radiologic success was achieved in 97% of cases, with a durable success rate of 84%. Clinical success was 94%, and complications occurred in 7.2% of patients, including two major events. Conclusions: TAE is a safe and effective treatment for renal AMLs. Tumor diameter >6.8 cm is a strong predictor of hemorrhage, while larger post-embolization volumes predict the need for re-intervention. These findings challenge the conventional 4 cm treatment threshold and support more individualized management strategies incorporating tumor morphology and response to embolization.

  PublisherOA PDFDOI

• 224eP Systemic mitochondrial alterations in patients with advanced non-small lung cancer revealed by [18F]F-AraG PET imaging

  Annals of Oncology · 2025-09-01

  article
  PublisherDOI

• Safety and efficacy of different transplant kidney biopsy techniques: comparison of two different coaxial techniques and needle types

  Abdominal Radiology · 2024-12-06 · 2 citations

  articleOpen access

  PURPOSE: Percutaneous ultrasound-guided renal biopsy is essential for diagnosing medical renal disorders in transplant kidneys. A variety of techniques have been advocated. The purpose of this study is to evaluate the safety and efficacy of two different coaxial techniques and biopsy devices. METHODS: This single-center dual-arm, observation study cohort included 1831 consecutive transplant kidney biopsies performed over a 68-month period. Two coaxial techniques were used, distinguished by whether the 17 gauge (G) coaxial needle was advanced into the renal cortex (intracapsular technique; IC) or to the edge of the cortex (extracapsular technique; EC). One of two needle types could be used with either technique: an 18G side-cutting (Bard Max-Core or Mission) or an 18G end-cutting (Biopince Ultra) needle. In all cases, the cortical tangential technique was used to reduce the risk of central artery transgression and unnecessary medullary sampling. Patients were monitored for 30 days post-procedurally and complications were evaluated using the SIR adverse event classification. RESULTS: Of the 1831 patients included in the study cohort, 13 suffered severe bleeding complications requiring operative intervention. Of these patients, 8 underwent biopsy with side-cutting needle and IC, 2 with side-cutting needle and approach not specified, 2 with end-cutting needle and IC, and 1 with end-cutting needle and EC. There was no statistically significant difference in the risk of bleeding complications between different coaxial techniques and needle types. However, there was a significantly increased chance of inadequate sampling when comparing the side-cutting needle (1.0%) to the end-cutting needle (0.1%). CONCLUSIONS: Transplant kidney biopsy performed with two different coaxial techniques and needle types did not show differences in bleeding complications. There is an increased risk of inadequate sampling when using side-cutting relative to end-cutting biopsy devices.

  PublisherOA PDFDOI

• [¹⁸F]F-AraG Uptake in Vertebral Bone Marrow May Predict Survival in Patients with Non–Small Cell Lung Cancer Treated with Anti-PD-(L)1 Immunotherapy

  Journal of Nuclear Medicine · 2024-10-24 · 6 citations

  articleOpen access

  Despite the systemic impact of both cancer and the associated immune response, immuno-PET is predominantly centered on assessment of the immune milieu within the tumor microenvironment. The aim of this study was to assess the value of [¹⁸F]F-AraG PET imaging as a noninvasive method for evaluation of system-wide immune status of patients with non–small cell lung cancer before starting immunotherapy. <b>Methods:</b> Eleven patients with advanced non–small cell lung cancer were imaged with [¹⁸F]F-AraG before starting immunotherapy. Diagnostic [¹⁸F]FDG PET/CT scans were analyzed to assess differences in the extent of disease among patients. SUV_max, SUV_mean, and total SUV (SUV_total) from all tumor lesions, active lymph nodes, spleen, vertebral bone marrow, liver, thyroid, heart, and bowel were extracted from the baseline [¹⁸F]F-AraG scans, and discriminant and Kaplan–Meier analyses were performed to test their ability to predict patient response and overall survival. <b>Results:</b> The extent of the disease was variable in the patient cohort, but none of the [¹⁸F]FDG biomarkers associated with tumor burden (SUV_max, total metabolic tumor volume, and total lesion glycolysis) was predictive of patient survival. The differences in the [¹⁸F]F-AraG and [¹⁸F]FDG distribution were observed both within and between lesions, confirming that they capture distinct aspects of the tumor microenvironment. Of the 3 SUV parameters studied, [¹⁸F]F-AraG SUV_total provided a dynamic range suitable for stratifying tumors or patients according to their immune activity. [¹⁸F]F-AraG SUV_total measured in the lumbar and sacral vertebrae differentiated between patients who progressed on therapy and those who did not with 90.9% and 81.8% accuracy, respectively. The Kaplan–Meier analysis revealed that patients with high [¹⁸F]F-AraG SUV_total in the lumbar bone marrow had significantly lower probability of survival than those with a low signal (<i>P</i> = 0.0003). <b>Conclusion:</b> This study highlights the significance of assessing systemic immunity and indicates the potential of the [¹⁸F]F-AraG bone marrow signal as a predictive imaging biomarker for patient stratification and treatment guidance.

  PublisherOA PDFDOI

• Comparison of Abbreviated MRI with Hepatobiliary Phase Sequences versus Full Protocol MRI in Post-Microwave Ablation Surveillance of HCC

  Proceedings on CD-ROM - International Society for Magnetic Resonance in Medicine. Scientific Meeting and Exhibition/Proceedings of the International Society for Magnetic Resonance in Medicine, Scientific Meeting and Exhibition · 2024-11-26

  article

  Motivation: The study seeks to validate an abbreviated MRI protocol for HCC post-treatment surveillance. Goal(s): To determine whether an abbreviated MRI protocol is as effective as full protocol MRI for HCC surveillance post-MWA. Approach: A retrospective cohort study comparing abbreviated MRI to full protocol MRI in detecting HCC recurrence after microwave ablation. Results: The abbreviated MRI achieved an acceptable sensitivity, specificity, and negative predictive value, specificity in detecting local HCC recurrences post-MWA, indicating effective secondary surveillance potential. Impact: The study demonstrates that abbreviated MRI can effectively monitor HCC post-treatment, offering a less burdensome and cost-effective surveillance method with high accuracy, paving the way for streamlined clinical monitoring protocols.

  PublisherDOI

• Neurocognitive Functioning is Impaired in Perinatally HIV-Infected Youth

  medRxiv · 2024-08-29

  preprintOpen access

  Background: The present study examined neurocognitive differences between Perinatally HIV (PHIV)-infected-youth and age and gender matched healthy controls. Despite early, long-term anti-viral treatment (ART), significant neurocognitive deficiencies remain for PHIV-infected-youth reaching adulthood compared to controls. Methods: Participants were assessed with a comprehensive neuropsychological battery. An Overall Neurocognitive Composite Score and a Global Deficit Score (GDS) were created. Sleep, depression, and developmental level of intellectual functioning were also examined. Results: PHIV-youth performed more poorly than controls in all neurocognitive domains. Very large effect sizes were observed for the Overall Neurocognitive Composite Score and GDS. PHIV-infected-youth appear to be significantly more depressed compared to controls, but there were no differences in amount or type of sleep observed. Conclusion: Despite early, long-term anti-viral treatment (ART), neurocognitive deficiencies remain for PHIV-infected-young-adults. The verbal learning domain was significantly impaired with implications for functioning. The PHIV-infected-youth were also depressed and not receiving treatment for depression.

  PublisherOA PDFDOI

• Abstract No. 194 Assessing Changes in Quality of Life in Comparison to Prostate Volume Reduction on Multiparametric MRI in Patients with Prostate Cancer Treated by Transurethral Ultrasound Ablation (TULSA): A Five-Year Follow-Up Study

  Journal of Vascular and Interventional Radiology · 2024-02-21

  articleOpen access
  PublisherOA PDFDOI

• Demographic and Socioeconomic Risk Factors for Granulomatous Mastitis in the United States: A Case-Control Study

  Journal of Breast Imaging · 2023-02-18 · 5 citations

  articleOpen access

  OBJECTIVE: Granulomatous mastitis (GM) is a benign breast disease that can have an extended clinical course impacting quality of life and causing breast disfigurement. Granulomatous mastitis has been studied throughout the world; however, less is known about GM patients in the United States. We aim to identify demographic and socioeconomic factors associated with GM in the United States. METHODS: An IRB-approved retrospective case-control study was performed of 92 patients with biopsy-proven GM at two institutions in Los Angeles, California: a safety-net hospital and an academic institution. Age-matched controls were selected from patients presenting for diagnostic breast imaging. Demographic and socioeconomic characteristics were collected. Data were analyzed using univariable test for odds ratios (ORs) with 95% confidence intervals (CIs) and multivariable conditional logistic regression. RESULTS: Patients with GM were more likely to prefer Spanish language (OR 6.20, 95% CI: 2.71%-14.18%), identify as Hispanic/Latina (OR 5.18, 95% CI: 2.38%-11.30%), and be born in Mexico (OR 3.85, 95% CI: 1.23%-12.02%). Cases were more likely to have no primary care provider (OR 3.76, 95% CI: 1.97%-7.14%) and use California Medicaid for undocumented adults (OR 3.65, 95% CI: 1.89%-7.08%). In the multivariable analysis, participants who preferred Spanish language had four times higher odds of GM versus those who preferred English language (OR 4.32, 95% CI: 1.38%-13.54%). CONCLUSION: Patients with GM may have barriers to health care access, such as preferring Spanish language, being an undocumented immigrant, and not having a primary care provider. Given these health care disparities, further research is needed to identify risk factors, etiologies, and treatments for this subset of GM patients.

  PublisherOA PDFDOI

• Combination transarterial chemoembolization and microwave ablation vs. microwave ablation monotherapy for hepatocellular carcinomas greater than 3 cm: a comparative study

  Diagnostic and Interventional Radiology · 2023-09-04 · 3 citations

  articleOpen access

  PURPOSE: To evaluate the efficacy of combination therapy using transarterial chemoembolization with microwave ablation (MWA) therapy vs. MWA monotherapy for hepatocellular carcinomas (HCCs) >3 cm in size. METHODS: This two-arm retrospective observational study included patients with HCCs >3 cm who underwent either combination therapy (29 patients) or MWA monotherapy (35 patients) between 2014 and 2020. The treatment outcomes related to primary treatment efficacy, local tumor progression (LTP), tumor control rate, and overall survival were compared between each cohort. RESULTS: = 0.235). CONCLUSION: The combination therapy provided significantly longer upfront LTP-free survival in HCCs >3 cm when compared with the MWA treatment alone, albeit with similar local tumor control and overall survival rates when accounting for additional locoregional therapies.

  PublisherDOI

Frequent coauthors

• Jorge L. M. Rodrigues

  University of California, Davis

  6 shared

• Michelle Heck

  Robert W. Holley Center for Agriculture & Health

  3 shared

• Daoyuan Wang

  Shanghai University

  3 shared

• Jonathan Y. Lin

  Stanford University

  2 shared

• Kate M. Scow

  University of California, Davis

  2 shared

• Aurélie Bak

  University of California, Davis

  1 shared

• Cody Ender

  Bear Valley

  1 shared

• Radomir Schmidt

  University of California, Davis

  1 shared