Ocular complications of diabetes mellitus (DM) are the leading cause of vision loss. Ocular inflammation often occurs in the early stage of DM; however, there are no proven quantitative methods to evaluate the inflammatory status of eyes in DM. The 18 kDa translocator protein (TSPO) is an evolutionarily conserved cholesterol binding protein localized in the outer mitochondrial membrane. It is a biomarker of activated microglia/macrophages; however, its role in ocular inflammation is unclear. In this study, fluorine-18-DPA-714 ([18F]-DPA-714) was evaluated as a specific TSPO probe by cell uptake, cell binding assays and micro positron emission tomography (microPET) imaging in both in vitro and in vivo models. Primary microglia/macrophages (PMs) extracted from the cornea, retina, choroid or sclera of neonatal rats with or without high glucose (50 mM) treatment were used as the in vitro model. Sprague-Dawley (SD) rats that received an intraperitoneal administration of streptozotocin (STZ, 60 mg/kg once) were used as the in vivo model. Increased cell uptake and high binding affinity of [18F]-DPA-714 were observed in primary PMs under hyperglycemic stress. These findings were consistent with cellular morphological changes, cell activation, and TSPO up-regulation. [18F]-DPA-714 PET imaging and biodistribution in the eyes of DM rats revealed that inflammation initiates in microglia/macrophages in the early stages (3 weeks and 6 weeks), corresponding with up-regulated TSPO levels. Thus, [18F]-DPA-714 microPET imaging may be an effective approach for the early evaluation of ocular inflammation in DM.

A 59-year-old man, previously submitted to anterior resection due to rectal cancer, underwent a contrast-enhanced computed tomography (ce-CT) for restaging before eventual chemotherapy. Because ce-CT showed a moderate enlargement of the descending colonic lumen, in despite the lack of symptoms, positron emission tomography (PET)/CT 18F-fluorodeoxyglucose (FDG) was carried out. 18F-FDG PET/CT demonstrated highly increased tracer incorporation along the colon walls. Two days after the PET/CT examination, complaints of diarrhea and abdominal pain began. Clostridioides difficile stool test resulted positiv; thus, thus he started antibiotic therapy without benefit. Because follow-up ce-CT demonstrated a megacolon condition, he was submitted to hemicolectomy. Histology revealed a diffuse condition of pseudomembranous colitis (PMC). This case highlights the potential of 18F-FDG PET/CT for detecting PMC morphological and functional features also in pre-symptomatic patients.
Daha önce rektum kanseri nedeniyle anterior rezeksiyon uygulanan 59 yaşında bir erkek hastaya nihai kemoterapiden önce yeniden evreleme için kontrastlı bilgisayar tomografi (k-BT) uygulandı. K-BT’de, hastanın semptomu olmamasına rağmen inen kolonik lümende orta derecede genişleme görüldüğünden, 18F-florodeoksiglukoz (FDG) ile pozitron emisyon tomografi (PET)/BT çekildi. 18F-FDG PET/BT’de kolon duvarları boyunca artmış aktivite tutulumu görüldü. PET/BT incelemesinden iki gün sonra hastanın ishal ve karın ağrısı şikayetleri başladı. Clostridioides difficile’ye yönelik gaita testi pozitif sonuçlandı, antibiyotik tedavisine başlandı ancak hasta fayda görmedi. Takip k-BT bir megakolon durumunu gösterdiğinden, hasta hemikolektomiye gönderildi. Histoloji, yaygın bir psödomembranöz kolit (PMC) ile uyumlu idi. Bu olgu, 18F-FDG PET/BT’nin pre-semptomatik hastalarda da PMC’nin morfolojik ve fonksiyonel özelliklerini saptama potansiyelini vurgulamaktadır.

BACKGROUND: Abnormal activation of immune system is an important pathogenesis of Parkinson\'s disease, but the relationship between peripheral inflammation, central microglia activation and dopaminergic degeneration remains unclear.
OBJECTIVE: To evaluate the brain regional microglia activation and its relationship with clinical severity, dopaminergic presynaptic function, and peripheral inflammatory biomarkers related to adaptive immunity.
METHODS: In this case-control study, we recruited 23 healthy participants and 24 participants with early-stage Parkinson\'s disease. 18F-PBR06 PET/MR for microglia activation, 18F-FP-DTBZ for dopaminergic denervation, total account of T cells and subpopulations of T helper (Th1/Th2/Th17) cells, and the levels of serum inflammatory cytokines were assessed. Sanger sequencing was used to exclude the mix-affinity binders of 18F-PBR06-PET.
RESULTS: Compared to healthy controls, patients with Parkinson\'s disease had an increased 18F-PBR06-PET standardized uptake value ratio (SUVR) in the putamen, particularly in the ipsilateral side of the motor onset. 18F-PBR06-PET SUVR was positively associated with 18F-FP-DTBZ-PET SUVR in the brainstem and not associated with disease severity measured by Hoehn and Yahr stage, MDS-UPDRS III scores. Patients with Parkinson\'s disease had elevated frequencies of Th1 cells and serum levels of IL10 and IL17A as compared to healthy controls. No significant association between peripheral inflammation markers and microglia activation in the brain of PD was observed.
CONCLUSIONS: Parkinson\'s disease is associated with early putaminal microglial activation and peripheral phenotypic Th1 bias. Peripheral adaptive immunity might be involved in microglia activation in the process of neurodegeneration in PD indirectly, which may be a potential biomarker for the early detection and the target for immunomodulating therapy.

BACKGROUND: Granulocyte colony-stimulating factor (G-CSF) is a cytokine produced in inflammatory environments that induces differentiation and proliferation of neutrophils in bone marrow. We report a rare case of aggressive G-CSF-producing squamous cell carcinoma of the tongue exhibiting fluorine-18 deoxyglucose (FDG) accumulation in primary lesion, metastatic lymph nodes, spleen, and bone marrow on positron emission tomography-computed tomography (PET/CT).
METHODS: We report a 58-year-old female with a rapid enlarged lingual mass with partial necrosis. Blood test results from the initial examination revealed a leukocyte count of 21380/µL. On PET/CT, extensive FDG accumulation was observed in the tongue and bilateral cervical lymph nodes, with elevated FDG accumulation in the spleen and bone marrow although no distant metastases were observed. We performed partial glossectomy and bilateral neck dissection. Immunohistochemical staining with G-CSF antibodies on biopsy specimen and resected samples revealed that both specimens were G-CSF positive. This is a rare case of G-CSF producing tongue carcinoma with elevated FDG accumulation in the spleen and bone marrow.
CONCLUSIONS: In patients with the tongue cancer and hyperleukocytosis, where FDG accumulations in the spleen and bone marrow are observed using PET/CT and when these accumulations are not caused by metastasis, G-CSF-producing tumors, with associated poor prognosis, should be considered.

OBJECTIVE: The present study investigated the dynamics and prognostic role of messenger RNA (mRNA) expression responsible for ¹⁸F-fluorodeoxyglucose (FDG) uptake in FDG positron emission tomography (PET) and radioactive iodine (¹³¹I) uptake in whole-body radioactive iodine scans (WBS) in papillary thyroid cancer (PTC) patients.
METHODS: The primary and processed data were downloaded from the Genomic Data Commons Data Portal. Expression data for sodium/iodide symporter (solute carrier family 5 member 5, SLC5A5), hexokinase (HK1-3), glucose-6-phosphate dehydrogenase (G6PD), and glucose transporter (solute carrier family 2, SLC2A1-4) mRNA were collected.
RESULTS: Expression of SLC5A5 mRNA were negatively correlated with SLC2A1 mRNA and positively correlated with SLC2A4 mRNA. In PTC with BRAF mutations, expressions of SLC2A1, SLC2A3, HK2, and HK3 mRNA were higher than those in PTC without BRAF mutations. Expression of SLC5A5, SLC2A4, HK1, and G6PD mRNA was lower in PTC without BRAF mutation. PTCs with higher expression of SLC5A5 mRNA had more favorable disease-free survival, but no association with overall survival.
CONCLUSIONS: Expression of SLC5A5 mRNA was negatively correlated with SLC2A1 mRNA. This finding provides a molecular basis for the management of PTC with negative WBS using ¹⁸F-FDG PET scans. In addition, higher expression of SLC5A5 mRNA was associated with less PTC recurrence, but not with deaths.