Use of Food to Cope With Culturally Relevant Stressful Life Events Is Associated With Body Mass Index in African American Women.

BACKGROUND: Although stress is an established contributor to obesity (in general population studies), mechanisms to explain this association in African American women that incorporate culturally relevant frameworks have received little attention. OBJECTIVE: To investigate how stress is associated with body mass index (BMI) in this population, we examined multivariate models of BMI predicted by race-related, gender-related, and generic stressful life events and by use of food to cope with stress. We hypothesized that the three types of stressful life events would be indirectly associated with BMI through using food to cope with stress. METHODS: Psychometrically robust measures were included in surveys administered to a socioeconomically diverse sample of 189 African American women aged 21-78 years. Hypotheses were tested using structural equation modeling. We examined race-related, gender-related, and generic stressful life events as latent constructs indicated by exposure to and appraisal of potential stressors predicting a mediator, using food to cope, which predicted BMI; this model also included direct paths from the three latent stressful life event constructs to BMI. RESULTS: Almost every participant reported using food in some way to cope with stress; 33% and 42% met established criteria for overweight and obesity, respectively. The race-related stressful life event construct was the only latent construct predicting using food to cope with stress, and using food to cope with stress predicted BMI. A significance test of indirect effects demonstrated that the race-related stressful life event construct was indirectly associated with BMI through the mediator, using food to cope. DISCUSSION: Culturally relevant stress exposures and stress-related eating are important areas of foci for tackling overweight, obesity, and related health inequities in African American women. Findings highlight the importance of developing more complex models to understand the stress-related factors that elevate risk for overweight and obesity in this population.

Gallium-68 prostate-specific membrane antigen ([68Ga]Ga-PSMA-11) PET for imaging of thyroid cancer: a feasibility study.

BACKGROUND: Prostate-specific membrane antigen (PSMA) is expressed in the microvasculature of thyroid cancer. This suggests the potential use of PSMA as a diagnostic agent in patients with aggressive forms of thyroid cancer. The purpose of the current study was to determine the feasibility and utility of [68Ga]Ga-PSMA-11 PET/MRI in thyroid cancer patients. METHODS: Eligible patients for this prospective pilot study were adults with a history of pathology-proven thyroid cancer who had abnormal radiotracer uptake on an 2-[18F]FDG PET and/or 131I scintigraphy performed in the 12 months prior to study enrollment. Patients underwent a [68Ga]Ga-PSMA-11 PET/MRI, and comparison was made to the prior qualifying 2-[18F]FDG PET CT/MRI for lesion location and relative intensity. RESULTS: Twelve patients underwent [68Ga]Ga-PSMA-11 PET/MRI, one of which was excluded from analysis due to debulking surgery prior to the PSMA PET. Of the remaining patients, 7/11 had differentiated disease (3 papillary, 2 follicular, 2 Hurthle cell) and 4/11 had dedifferentiated disease (2 poorly differentiated papillary, 2 anaplastic). Out of 43 lesions, 41 were visually 2-[18F]FDG positive (uptake greater than background, detection rate 95.3%) and 28 were PSMA positive (uptake greater than background, detection rate 65.1%). Uptake was heterogeneous between patients, and in some cases within patients. 3/11 patients (1 poorly differentiated papillary, 2 follicular) had PSMA uptake which was greater than FDG uptake. For the remaining 8 patients, 2-[18F]FDG uptake was greater than PSMA. Using one eligibility guideline in the prostate cancer literature for PSMA radioligand therapy (RLT), 8/11 could be considered eligible for possible future PSMA RLT. This was not predictable based on thyroid cancer subtype. CONCLUSIONS: [68Ga]Ga-PSMA-11 PET demonstrated lower detection rate when compared to 2-[18F]FDG PET for thyroid cancer lesion visualization. Thyroid cancer subtype alone may not be sufficient to predict PSMA uptake, and radiotracer uptake may vary between patients and even within patients.

68Ga-PSMA-11 PET/MRI: determining ideal acquisition times to reduce noise and increase image quality.

BACKGROUND: In this study, we investigate the impact of increased PET acquisition time per bed position on lesion detectability, standard uptake value, and image noise in 68Ga-PSMA-11 PET/MRI scans. METHODS: Scans of twenty patients were analyzed in this study. Patients were injected with 68Ga-PSMA-11 (mean, 5.50 ± 1.49 mCi) and imaged on a 3.0 T time-of-flight PET/MRI. PET images were retrospectively reconstructed using 0.5, 1, 2, 4, 7, and 10 min of PET data. Lesion detectability was evaluated on a 5-point Likert Scale for each lesion in each reconstruction. Quantitative analysis was performed measuring image noise and lesion uptake. RESULTS: A total of 55 lesions were identified, and lesion detectability increased from 2.07 ± 1.14 for 0.5 min to 4.93 ± 0.26 for 10 min (p < 0.001), with no significant difference detected between 7 and 10 min of scan time. Average SUVmax decreased from 9.89 ± 6.62 for 0.5 min to 8.64 ± 6.81 for 10 min. Noise decreased from 0.72 ± 0.22 for 0.5 min to 0.31 ± 0.12 for 10 min (p < 0.001) and were nearly equivalent between 7 and 10 min. Pairwise interaction terms between size, SUVmax, and scan time were all found to be significant, although the interaction term between SUVmax and scan time was found to be the most significant. CONCLUSIONS: Increased acquisition duration improves image quality by increasing detectability and reducing noise. In patients with biochemical recurrence, increased acquisition time up to 7 min improves lesion detection.

Single-Step Self-Assembly and Physical Crosslinking of PEGylated Chitosan Nanoparticles by Tannic Acid.

Chitosan-based nanoparticles are promising materials for potential biomedical applications. We used Flash NanoPrecipitation as a rapid, scalable, single-step method to achieve self-assembly of crosslinked chitosan nanoparticles. Self-assembly was driven by electrostatic interactions, hydrogen bonding, and hydrophobic interactions; tannic acid served to precipitate chitosan to seed nanoparticle formation and crosslink the chitosan to stabilize the resulting particles. The size of the nanoparticles can be tuned by varying formulation parameters including the total solids concentration and block copolymer to core mass ratio. We demonstrated that hydrophobic moieties can be incorporated into the nanoparticle using a lipophilic fluorescent dye as a model system.

Assessment of 68Ga-PSMA-11 PET Accuracy in Localizing Recurrent Prostate Cancer: A Prospective Single-Arm Clinical Trial.

IMPORTANCE: In retrospective studies, 68Ga-PSMA-11 positron emission tomographic (PET) imaging improves detection of biochemically recurrent prostate cancer compared with conventional imaging. OBJECTIVE: To assess 68Ga-PSMA-11 PET accuracy in a prospective multicenter trial. DESIGN, SETTING, AND PARTICIPANTS: In this single-arm prospective trial conducted at University of California, San Francisco and University of California, Los Angeles, 635 patients with biochemically recurrent prostate cancer after prostatectomy (n = 262, 41%), radiation therapy (n = 169, 27%), or both (n = 204, 32%) underwent 68Ga-PSMA-11 PET. Presence of prostate cancer was recorded by 3 blinded readers on a per-patient and per-region base. Lesions were validated by histopathologic analysis and a composite reference standard. MAIN OUTCOMES AND MEASURES: Endpoints were positive predictive value (PPV), detection rate, interreader reproducibility, and safety. RESULTS: A total of 635 men were enrolled with a median age of 69 years (range, 44-95 years). On a per-patient basis, PPV was 0.84 (95% CI, 0.75-0.90) by histopathologic validation (primary endpoint, n = 87) and 0.92 (95% CI, 0.88-0.95) by the composite reference standard (n = 217). 68Ga-PSMA-11 PET localized recurrent prostate cancer in 475 of 635 (75%) patients; detection rates significantly increased with prostate-specific antigen (PSA): 38% for <0.5 ng/mL (n = 136), 57% for 0.5 to <1.0 ng/mL (n = 79), 84% for 1.0 to <2.0 ng/mL (n = 89), 86% for 2.0 to <5.0 ng/mL (n = 158), and 97% for ≥5.0 ng/mL (n = 173, P < .001). Interreader reproducibility was substantial (Fleiss κ, 0.65-0.78). There were no serious adverse events associated with 68Ga-PSMA-11 administration. PET-directed focal therapy alone led to a PSA drop of 50% or more in 31 of 39 (80%) patients. CONCLUSIONS AND RELEVANCE: Using blinded reads and independent lesion validation, we establish high PPV for 68Ga-PSMA-11 PET, detection rate and interreader agreement for localization of recurrent prostate cancer. TRIAL REGISTRATION: ClinicalTrials.gov identifiers: NCT02940262 and NCT03353740.