ABSTRACT
Objective:To investigate the kinetic metrics of 68Ga-fibroblast activation protein inhibitor (FAPI)-04 in pancreatic cancers and normal organs by using total-body PET dynamic imaging. Methods:From December 2020 to December 2021, 68Ga-FAPI-04 total-body PET/CT dynamic imaging were performed on 6 pancreatic cancer patients (3 males, 3 females, median age 55.5 years) in Ren Ji Hospital, School of Medicine, Shanghai Jiao Tong University. Images were respectively analyzed. Manual delineations of volume of interests (VOIs) on multiple normal organs and pathological lesions were performed and time-to-activity curves (TACs) were generated. A reversible two-tissue compartment model (2TCM) was fitted for each tissue TAC. Rate constants including K1, k2, k3 and k4, and the total volume of distribution ( Vt) were obtained and compared by tissue types. Wilcoxon rank sum test and Spearman correlation analysis were used for data analysis. Results:Kinetic metrics varied significantly among normal organs and pancreatic cancer lesions ( z values: 2.00-1 240.00, all P<0.05). The highest K1 among lesions was observed in primary tumor (0.30 min -1), which was observed in the spleen (1.42 min -1) among normal organs. The highest k2 among lesions was observed in peritoneal metastases (0.24 min -1), which was observed in the spleen (2.59 min -1) among normal organs. Primary tumor showed the highest k3 of 0.17 min -1 among lesions, and the pancreas had the highest k3 of 0.16 min -1 among normal organs. Primary tumor had the highest k4 of 0.03 min -1 among lesions, and the heart, lungs, parotid glands had high k4(0.06 min -1) among normal organs. Vt were higher in pathological lesions compared to normal organs, with the highest in primary tumor (13.78 ml/cm 3). There were correlations between Vt in lesions and SUV mean( rs=0.86, P<0.001) or SUV max ( rs=0.77, P<0.001). Conclusion:The rate constants including K1, k2, k3 and k4, and Vt of 68Ga-FAPI-04 vary among normal organs and lesions.
ABSTRACT
Objective To introduce a practical high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS)method for the detection of seven growth hormone-releasing peptides (GHRPs)including GHRP-1,GHRP-2,GHRP-4,GHRP-5,GHRP-6,Hexarelin and Alexamorelin and two growth hormone secretagogues(GHS)including anamorelin and ipamorelin,and study the stability of these nine substances in the human urine.Method The urine samples were purified and extracted by a solid phase extraction procedure using Oasis(R) WCX column.The urine was first centrifuged and taken out 1 mL into a small column,cleaned by 5％ NH4OH and 20％ CH3CN respectively,eluated using the mixture of water and acetomitrile(1/3)with 2％ formic acid,blow-dried in the nitrogen at 35℃ and finally redissolved to be injected into the LC-MS/MS.Result The limits of detection were between 0.01～0.5 ng/mL accordingly.The spiked recoveries at the low concentration(1 ng/mL),medium concentration(2 ng/mL)and high concentration(10 ng/mL)ranged between 40％ and 76％.The intra-and interday precisions of the target substances at these three concentrations were all less than 15％.The indoor temperature,refrigeration condition and multigelation were observed to have significant impact on the anamorelin,GHRP-2,GHRP-4 and GHRP-5.Conclusion The method established in this study is simple,and its specificity and sensitivity meets the international standard and technical documents for laboratories set up by the Wworld Anti-Doping Agency.It has been applied in our routine work.Multigelation should be avoided in the transport,detection and long-term laboratory storage of urine samples.
ABSTRACT
Cytochrome P450 (CYP450) is a superfamily of heme-thiolate proteins, which is involved in the metabolism and activation of various endogenous and exogenous substances, including food, drugs and pollutants. Previous studies of the CYP450 genes mainly focused on their function in drug metabolism. However, in recent years, studies have found that CYP450 are also involved in the development and progression of various diseases, including Parkinson's disease (PD), cancer, cardiomyopathy and heart failure (HF). By far, the process and related mechanisms of CYP450 in the metabolism of endogenous substances in brain tissues has not been clarified yet. In this paper, we summarized the research progress of CYP450 genes involved in the metabolism of endogenous substances, in order to provide a new idea for the exploration of the functions of CYP450 genes expressed in the brain.