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Objective. To investigate the biodistribution and kinetic constants of 68Ga-DOTATATE in normal organs through dynamic total-body positron emission tomography/computed tomography (PET/CT). Methods. Seven patients who experienced endoscopic resection of gastric neuroendocrine tumor were enrolled. Dynamic total-body PET/CT scans over 60 min were performed. Time-activity curves were obtained by drawing regions of interest in normal organs. Rate constants, including K1, k2, k3, and vB, were computed using a two-tissue compartment model. Factor analysis was used to compare the rate constants among subjects and regions. Hierarchical cluster analysis was performed to identify organs with similar kinetic characteristics. Results. The highest uptake of 68Ga-DOTATATE was observed in the spleen followed by kidneys, adrenals, liver, pituitary gland, pancreas head, prostate, pancreas body, and thyroid, parotid, and submandibular glands. Low background level of 68Ga-DOTATATE uptake was observed in the nasal mucosa, bone, blood pool, and cerebrum. In addition, the uptake in the pancreas head was noted to be higher than the pancreas body ( P < 0.001 ) on the basis of each time point of dynamic PET. There were differences of rate constants among different organs. The mean K1 ranged from 0.0507 min−1 in the left nasal mucosa to 1.21 min−1 in the left kidney, and mean k2 ranged from 0.0174 min−1 in the spleen to 4.4487 min−1 in the left cerebrum. The mean k3 ranged from 0.0563 min−1 in the right cerebrum to 4.6309 min−1 in the left adrenal, and mean vB ranged from 0.0001 in the left cerebrum to 0.2489 in the right adrenal. However, none of the rate constants was significantly different among subjects or among different sites within a single organ. Three groups of organs with similar kinetic characteristics were identified: (1) cerebrum; (2) pituitary gland, liver, adrenal, and prostate; and (3) nasal mucosa, parotid and submandibular glands, thyroid, spleen, pancreas, kidney, and bone. Conclusion. Uptake and clearance of 68Ga-DOTATATE, in terms of kinetic constants, were different in different organs. The kinetic parameters of 68Ga-DOTATATE in different organs provide a reference for future dynamic PET imaging.

In this study, aqueous film-forming foam, fluoroprotein foam, and synthetic foam were applied to extinguish the transformer oil pool fires. The fire-extinguishing performance and burn-back resistance were investigated using a laboratory fire-extinguishing system. Moreover, the emission products were analyzed to evaluate the gas-phase pollution characteristics. Results show that aqueous film-forming foam presents the highest fire-extinguishing efficiency, while fluoroprotein foam has the best burn-back performance. Flue gas and gas chromatography–mass spectrometer analyses demonstrate that the use of fluoroprotein foam results in much higher CO emissions than other foams, and the pollutants are mainly from various hydrocarbons produced by incomplete combustion of transformer oil. Synthetic foam and aqueous film-forming foam lead to higher SO2 and NO emissions, and pollutants are mainly dominated by alcohols and ethers. Noteworthily, when using aqueous film-forming foam to extinguish oil pool fire, a persistent organic pollutant, perfluorooctanoic acid, is detected in the gas phase.

Xiaonan Zhou,1,2,&ast; Kai Zhu,1,2,&ast; Yiqiu Zhang,3– 5,&ast; Yang Ming,1,2 Dai Shi,3– 5 Hui Tan,3– 5 Bitao Xiang,1,2 Shichao Zhu,1,2 Dengfeng Cheng,3– 5 Hao Lai,1,2 Chunsheng Wang,1,2 Guobing Liu3– 5 1Department of Cardiac Surgery, Zhongshan Hospital, Fudan University, Shanghai, 200032, People’s Republic of China; 2Shanghai Institute of Cardiovascular Diseases, Shanghai, 200032, People’s Republic of China; 3Department of Nuclear Medicine, Zhongshan Hospital, Fudan University, Shanghai, 200032, People’s Republic of China; 4Institute of Nuclear Medicine, Fudan University, Shanghai, 200032, People’s Republic of China; 5Shanghai Institute of Medical Imaging, Shanghai, 200032, People’s Republic of China&ast;These authors contributed equally to this workCorrespondence: Guobing Liu, Department of Nuclear Medicine, Zhongshan Hospital, Fudan University, No. 180 in Fenglin Road, Shanghai, 200032, People’s Republic of China, Tel +8618317086732, Fax +86-21-62489191, Email liu.guobing@zs-hospital.sh.cn Chunsheng Wang, Department of Cardiac Surgery, Zhongshan Hospital, Fudan University, No. 180 in Fenglin Road, Shanghai, 200032, People’s Republic of China, Email wangchunsheng@fudan.edu.cnPurpose: To investigate the feasibility of a pre-targeted imaging strategy based on the cycloaddition between 1,2,4,5-terazine (Tz) and trans-cyclooctene (TCO) for evaluating CD11b expression in inflammatory aortic aneurysm (AA) using single photon emission computed tomography/computed tomography (SPECT/CT).Methods: C57BL/6J mice were fed β-aminopropionitrile (1 g/kg/day) for 4 weeks to establish AA models. Anti-CD11b-TCO was synthesized and 99mTc-HYNIC-PEG11-Tz was designed for pre-targeted SPECT/CT. The affinity and specificity of the probe for the inflammatory cell line Raw-264.7 were investigated. Then, anti-CD11b-TCO pre-targeted and 99mTc-HYNIC-PEG11-Tz based SPECT/CT were performed to detect in vivo inflammation in AA. Finally, ex vivo aortic breast-specific gamma imaging (BSGI), Western blot assays, and immunohistochemical CD11b staining were performed to confirm the in vivo findings of SPECT/CT.Results: In the AA models, 65.22% (15/23) had aortic lesions, including 43.48% (10/23) AA lesions. The anti-CD11b-TCO presented with a high TCO coupling ratio (7.43), and the 99mTc-HYNIC-PEG11-Tz showed high radio-purity (> 95%), good in vitro stability and a rapid clearance rate. Additionally, anti-CD11b-TCO and 99mTc-HYNIC-PEG11-Tz presented high click rate (∼ 89%). The in vitro clicked compound, 99mTc-HYNIC-PEG11-Tz/TCO-anti-CD11b, showed high affinity and specificity for Raw-264.7 cells. 99mTc-HYNIC-PEG11-Tz/TCO-anti-CD11b pre-targeting SPECT/CT successfully demonstrated inflammatory AA with a high AA-to-background ratio in AA mice, compared to AA mice that were injected with 99mTc-HYNIC-Tz/TCO-IgG (8.13 versus 3.71, P < 0.001) and control mice injected with 99mTc-HYNIC-Tz/TCO-anti-CD11b (8.13 versus 3.66, P < 0.001). This result was confirmed by ex vivo BSGI performed immediately after SPECT/CT and immunohistochemical CD11b staining.Conclusion: SPECT/CT imaging using the anti-CD11b-TCO/Tz-PEG11-HYNIC-99mTc based pre-targeting imaging strategy allows for the detection of inflammation in progressive AA.Keywords: aortic aneurysm, inflammation, SPECT/CT, CD11b, macrophage

Mutations in isocitrate dehydrogenase 1 (IDH1) are commonly found in various human malignancies. Inhibitors of several mutant IDH1 enzymes have entered clinical trials as target therapeutic drugs for the treatment of patients with IDH1 mutations. Herein, we report the synthesis and evaluation of two 18F-labeled tracers, [18F]AG120 and [18F]AG135 for imaging expression of mutated IDH1 in positron emission tomography (PET). [18F]AG120 and [18F]AG135 were synthesized in decay-corrected radiochemical yield of 1 % and 3 %, respectively, high molar activity (52–66 MBq/nmol and 216–339 MBq/nmol, respectively) and high radiochemical purity (>99%). Both tracers showed good in vitro stability, selective uptake into mutated IDH1-expressing cells and good pharmacokinetic profiles with low uptake in most organs/tissues. Furthermore, [18F]AG120 micro-PET/CT imaging displayed significantly greater uptake in IDH1-mutant than in wild-type tumors, Relatively, uptake of [18F]AG135 was observed neither in IDH1-mutant tumor xenografts nor in wild-type tumors. This study suggests that [18F]AG120 is a promising radiotracer for PET imaging of IDH1 mutation, However, further optimization and investigation are necessary for [18F]AG135 due to the limited uptake in mutated IDH1-expressing tumors.