Unlabelled: The assessment of myocardial radiotracer kinetics, including cardiac extraction fraction and washout, requires the study of isolated perfused hearts to avoid analytic error due to tracer recirculation and systemic metabolites. Analysis of the isolated perfused rat heart by a high-resolution small-animal PET system may offer both reliable evaluation of cardiac tracer kinetics and tomographic images.
Methods: An isolated perfused heart system was modified to accommodate the small PET gantry bore size. Isolated rat hearts were perfused via the Langendorff method under a constant flow of Krebs-Henseleit buffer containing (18)F-FDG with a rate of 5 mL/min and placed in the field of view of the commercially available small-animal PET system. Dynamic PET imaging was then performed, with (18)F-FDG uptake in the isolated perfused heart verified by γ counter measurements. Additionally, a rat heart of myocardial infarction was also studied in this system with static PET imaging.
Results: Dynamic PET acquisition of the isolated heart under constant (18)F-FDG infusion demonstrated continuous increase of activity in the heart. Correlation between cardiac activity (MBq) measured with the PET system and measurements made with the γ counter were excellent (R(2) = 0.98, P < 0.001, n = 10). Tracer input rate (MBq/min) was also well correlated with cardiac tracer uptake rate (MBq/min) (R(2) = 0.87, P < 0.001, n = 12). PET imaging of the heart with myocardial infarction showed a clear tracer uptake defect corresponding to the location of scar tissue identified by autoradiography and histology.
Conclusion: Combining the Langendorff method of isolated rat heart perfusion with high-resolution small-animal PET allows for the reliable quantification of myocardial tracer kinetics. This novel assay is readily adapted to available small-animal PET systems and may be useful for understanding myocardial PET tracer kinetics.
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http://dx.doi.org/10.2967/jnumed.113.129429 | DOI Listing |
Vet Sci
January 2025
Faculty of Veterinary Medicine, Chiang Mai University, Chiang Mai 50100, Thailand.
Can black soldier fly (BSF) larvae be a protein substitute for managing adverse food reactions (AFRs) in dogs, specifically those with dermatitis? We evaluated BSF larvae's safety, tolerance, and effectiveness as a novel protein source in dogs with AFRs. Sixteen dogs, including eight healthy controls and eight diagnosed with AFRs, were fed a diet containing BSF larvae for four weeks. Skin conditions, including dermatological lesions and Pruritus Visual Analog Scale (PVAS) scores, and gastrointestinal signs, including relevant clinical signs, stool consistency, and hematological and biochemical parameters, were monitored.
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January 2025
Department of Nuclear Medicine, West China Hospital, Sichuan University, Chengdu, China
Fibroblast activation protein (FAP) has been considered a promising target for tumor imaging and therapy. This study designed a novel peptide, FAP-HXN, specifically targeting FAP and exhibiting significant potential as a radionuclide-labeled theranostic agent. Preclinical studies were conducted to evaluate the potency, selectivity, and efficacy of FAP-HXN.
View Article and Find Full Text PDFJ Nucl Med
January 2025
Department of Biomedical Imaging and Image-Guided Therapy, Medical University of Vienna, Vienna, Austria;
Tumor metabolism is a hallmark of cancer, yet cellular heterogeneity within the tumor microenvironment presents a significant challenge, as bulk analysis masks the diverse metabolic profiles of individual cell populations. This complexity complicates our understanding of [F]FDG uptake by distinct cell types in the tumor microenvironment. This study aims to investigate [F]FDG uptake at the single-cell level in the lung of Kirsten rat sarcoma virus-driven cancer mouse models using the novel technique radio-flow cytometry (radioFlow).
View Article and Find Full Text PDFPLoS One
January 2025
Arizona Humane Society, Phoenix, Arizona, United States of America.
SARS-CoV-2 is the cause of mild to severe acute respiratory disease that led to significant loss of human lives worldwide between 2019 and 2022. The virus has been detected in various animals including cats and dogs making it a major public health concern and a One Health issue. In this study, conjunctival and pharyngeal swabs (n = 350) and serum samples (n = 350) were collected between July and December 2020 from cats that were housed in an animal shelter and tested for the infection of SARS-CoV-2 using real time reverse-transcription polymerase chain reaction (rRT-PCR) that targeted the N1 and N2 genes, and a SARS-CoV-2 surrogate virus neutralization Test (sVNT), respectively.
View Article and Find Full Text PDFPhys Med Biol
January 2025
University of Aveiro, Physics Department Campus Universitário de Santiago, 3810-193 Aveiro, Portugal.
a new projector, orthogonal-distance ray-tracer varying-full width at half maximum (OD-RT-VF), was developed to model a shift-variant elliptical point-spread function (PSF) response to improve the image quality (IQ) of a preclinical dual-rotation PET system.the OD-RT-VF projector models different FWHM values of the PSF in multiple directions, using half-height and half-width tube-of-response (ToR) values. The OD-RT-VF method's performance was evaluated against the original OD-RT method and a ToR model with constant response.
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