Objective To optimize the synthesis method of ¹⁸F-T807 and study preliminary biodistribution. Methods ¹⁸F-T807 was synthesized using an optimized method in TRACERlab FX_FN synthesizer with a t-BOC（t-Butyloxy carbonyl）-protected ¹⁸F-T807 precursor NPPI-9 as starting material, improving experimental conditions for synthesis, then QC and biodistribution study in Wistar rats conducted. Results The improved synthesis conditions increased the synthesis yield from 20.5%±6.1% to 25.7%±5.8%. QC met the standard. Wistar rats had higher intake in kidney, liver, blood and lowest intake in brain, heart, lung. Conclusion The optimized synthesis method to synthesize ¹⁸F-T807 is simple and easy, and high yield, which can meet the needs of scientific research and clinical practice.

Objective To identify the genotype of the APP/tau/PS1 triple transgenic Alzheimer's disease (AD) mice,and investigate the pathological changes of tau protein in the pathogenic process.Methods Using specific primers of PS1,APP,tau gene,the genotypes of the triple transgenic AD mice were identified.Expression of tau protein in hippocampal tissue of mouse model aged 2,4,8 month was detected by immunohistochemistry.The expression of tau and its hyperphosphorylation in different sites in the hippocampal tissue and different month old mice was detected by Western blotting.Results PCR amplification fragment of 960 bp,530 bp and 400 bp of transgenic mouse genome were the expected size of APP,PS1,tau,respectively.Expression of tau in hippocampal CA3 region was increased obviously in the 8 month old mice.Compared with the normal wild-type mice,the expressions of tau and phosphorylation of pS262,pS404 and pS202 were increased significantly in hippocampus tissue of the transgenic mice (P＜0.01).Expression of tau were significantly higher in 8-and 12-monthsold mice than in 2 months-old mice (P ＜ 0.01).Phosphorylation level of pS404 and Ps202 was significantly increased since 2-months-old in transgenic mouse compared to the wild type mouse (P＜0.01),and in 8-monthold mice,there was also a significant increase as compared to that in 2 month-old mice (P＜0.01).As to the phosphorylation level of pSs262,the significant increase did not appear until 12 months old in transgenic mouse as compared to the wild type mouse (P＜0.01).Conclusions The triple transgenic mice can stably express the APP/tau/PS1 gene.The transgenic animals can be a useful model with the pathological features of tau of AD.The phosphorylation level of tau in different site increases in different time,which will provide useful research reference in Alzheimer's disease pathology and medication research.

Objective To analyze the metabolic differences of ¹¹C-flumazenil (¹¹C-FMZ) with different specific radioactivity by detecting the percentage proportion of the main metabolites in vivo. Methods 5 male and 5 female volunteers with average age of (41.7±4.7) years and weight of (69.3±6.8) kg were selected from May to October 2019. ¹¹C-FMZ with high and low specific radioactivity (268.3±57.2)×10³ and (57.8±11.4)×10³ Ci/mol was injected successively. The percentage of injected dose/liter of ¹¹C-FMZ and its metabolites in the plasma at 1, 2, 3, 4, 5, 10, 15, 20, 30, 40 and 60 min after the injection was measured. Paired sample mean t test was used to calculate and compare the percentage of metabolites in the two groups. Results The percentage proportion of metabolites increased gradually with time, and reached the stable level after 15 min. The percentage proportion of low specific radioactivity group was higher than that of high specific radioactivity group with a significant statistical difference between 15 min and 60 min (P<0.05). Conclusion The metabolic rate of ¹¹C-FMZ with different specific radioactivity was significantly different after injection and the specific radioactivity difference should be avoided if possible in clinical application.