Browsing by Author "Feng, Yang"

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    Assessment of folate receptor-β expression in human neoplastic tissues
    (Impact Journals, LLC, 2015-06-10) Shen, Jiayin; Putt, Karson S.; Visscher, Daniel W.; Murphy, Linda; Cohen, Cynthia; Singhal, Sunil; Sandusky, George; Feng, Yang; Dimitrov, Dimiter S.; Low, Philip S.; Department of Pathology & Laboratory Medicine, IU School of Medicine
    Over-expression of folate receptor alpha on cancer cells has been frequently exploited for delivery of folate-targeted imaging and therapeutic agents to tumors. Because limited information exists on expression of the beta isoform of the folate receptor in human cancers (FR-β), we have evaluated the immunohistochemical staining pattern of FR-β in 992 tumor sections from 20 different human cancer types using a new anti-human FR-β monoclonal antibody. FR-β expression was shown to be more pronounced in cells within the stroma, primarily macrophages and macrophage-like cells than cancer cells in every cancer type studied. Moreover, FR-β expression in both cancer and stromal cells was found to be statistically more prominent in females than males. A significant positive correlation was also observed between FR-β expression on stromal cells and both the stage of the cancer and the presence of lymph node metastases. Based on these data we conclude FR-β may constitute a good target for specific delivery of therapeutic agents to activated macrophages and that accumulation of FR-β positive macrophages in the stroma could serve as a useful indicator of a tumor's metastatic potential.
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    Quantifying Ventricular CSF Clearance in the Human Brain Using Dynamic 18F-FDG PET: Insights into Age-Related Glymphatic Impairment
    (medRxiv, 2025-04-09) Zhou, Zeyu; Zhao, Tianyun; Gardus, John I.; Wen, Qiuting; Feng, Yang; DeLorenzo, Christine; Parsey, Ramin; Huang, Chuan; Radiology and Imaging Sciences, School of Medicine
    Purpose: The glymphatic system facilitates brain waste clearance via cerebrospinal fluid (CSF) flow, and its dysfunction has been linked to aging and neurodegeneration. However, clinically accessible methods to quantify glymphatic function in humans remain limited. This study aimed to examine the potential of dynamic 18F-FDG PET for measuring ventricular CSF clearance - as a surrogate marker of glymphatic function. Specifically, we evaluated its association with age, its test–retest reliability, and the feasibility of reduced scan durations for clinical applicability. Methods: We analyzed 72 baseline 18F-FDG PET scans from participants enrolled in a prior depression trial. Time–activity curves (TACs) were extracted from the lateral ventricles and fitted with a γ-variate model to estimate influx (𝜇𝑖𝑛) and clearance (𝜇𝑜𝑢𝑡) parameters. Associations with age and clinical factors were examined using correlation and multiple linear regression. Test–retest reliability was assessed in 11 placebo-treated participants who underwent repeat scans eight weeks apart. A feasibility analysis tested whether shorter scan windows could yield comparable clearance estimates. Results: 𝜇𝑜𝑢𝑡 showed a strong negative correlation with age (r = −0.680, p < 0.001), while 𝜇𝑖𝑛 was not significantly age-related. Age remained a significant predictor of 𝜇𝑜𝑢𝑡 after adjusting for sex, ventricle size, and depression severity. A positive association between 𝜇𝑜𝑢𝑡 and depression severity was observed after covariate adjustment. Test–retest analysis yielded an intraclass correlation coefficient of 0.702 for 𝜇𝑜𝑢𝑡, indicating moderate-to-good reproducibility. A shortened 30-minute scan window (starting 30 minutes post injection) preserved strong correlations with both 𝜇𝑜𝑢𝑡 and age, supporting the potential for abbreviated imaging protocols. Conclusion: Dynamic 18F-FDG PET provides a reliable and noninvasive method to quantify ventricular CSF clearance, revealing age-related decline indicative of glymphatic impairment. The method demonstrates reproducibility over time and retains key clearance metrics even with shortened scan durations. These findings establish a clinically feasible 18F-FDG PET-based approach for studying brain clearance and glymphatic function in aging and disease.