ABSTRACT
Objective:To synthesize Gd labeled probe targeting transporter protein(TSPO) 2-(8-amino-2-(4-chlorophenyl)imidazo[1, 2-a]pyridine-3-yl)- N, N-dipropylacetamide (CB86)-diethylene triamine pentaacetic acid (DTPA), and investigate its MRI effect in rheumatoid arthritis (RA) model. Methods:CB86-DTPA was prepared by coupling a bifunctional chelating agent, and then chelated with Gd to obtain MRI targeted contrast agent CB86-DTPA-Gd. The cytotoxicity, MR relaxation rate and in vitro stability of CB86-DTPA-Gd were determined. RA model was established with Freund′s adjuvant and the biodistribution study and MRI was performed. The RA lesion and its surrounding normal tissue were used as regions of interest (ROI) to calculate the signal to noise ratio (SNR). Independent-sample t test was used to analyze the data. Results:CB86-DTPA-Gd had excellent biosafety and a good MR relaxation rate ( r1=11.05 mmol·L -1·s -1). The survival rate of RAW264.7 cells and 4T1 cells was still more than 90% at the maximum concentration (20 μmol/L) of Gd 3+. CB86-DTPA-Gd also exhibited good stability in human serum and phosphate buffer saline solution (PBS; pH=7.4). The in vivo biodistribution showed that CB86-DTPA-Gd had better inflammatory targeting efficiency, and the uptake of Gd in the inflamed site of the ankle joint was still (2.33±0.29) percent dose rate per gram of tissue (%ID/g) at 120 min after injection. MicroMRI showed that the inflammation of the right ankle joint displayed significant enhancement after the injection of CB86-DTPA-Gd and Gd-DTPA. The SNR of CB86-DTPA-Gd group was up to 23.21±1.44, and the maximum intensification time was 90 min after injection, and can be significantly inhibited by CB86-DTPA at all time points ( t values: 6.083-12.451, all P<0.05), while the Gd-DTPA group had a strengthening time of 30 min after injection with the SNR of 16.12±1.24. Conclusion:CB86-DTPA-Gd shows good macrophage targeting and good uptake in arthritic reaction sites, and is expected to be a novel MRI molecular probe for peripheral inflammation imaging.
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Objective To synthesize a novel 18 F labeled probe targeting translocator protein ( TSPO) ligand 2-( 5, 7-diethyl-2-( 4-( 2-fluoroethoxy ) phenyl ) pyrazolo [ 1, 5-a ] pyrimidin-3-yl )-N, N-diethylacet-amide (VUIIS1008), and evaluate its biodistribution and imaging in rheumatoid arthritis (RA) model. Methods The tosylate substrate was labeled with 18 F using a tosyloxy for fluorine nucleophilic aliphatic substitution to obtain 18 F-VUIIS1008. The labeling efficiency, radiochemical purity, and stability in vitro were determined. In vitro cellular uptake and competitive binding assay were performed on RAW264.7 mac-rophage cells. Biodistribution and microPET/CT imaging were investigated on RA mice established by Com-plete Freund's Adjuvant. Two-sample t test was used to analyze the data. Results 18 F-VUIIS1008 was syn-thesized with the labeling yield up to (41.00±5.00)％, the radiochemical purity>98.00％, and the specific radioactivity >1. 52 × 108 MBq/mmol. 18 F-VUIIS1008 was highly stable with the radiochemical purity >98. 00％ at 4 h after incubation in mouse serum. In vitro, it also exhibited high specific TSPO binding in RAW264.7 macrophage cells. The uptake ratio was (14.00±0.30)％ at 1 h after incubation, and decreased significantly ((4.00±0.70)％;t=12.894, P<0.05) after adding excessive unlabeled VUIIS1008. The half maximal inhibitory concentration (IC50) of 18F-VUIIS1008 binding to TSPO was 0.05 nmol/L in RAW264.7 macrophage cells. In vivo distribution results showed that the uptake of 18 F-VUIIS1008 in the left arthritic ankles reached the peak value of (1.33±0.02) percentage activity of injection dose per gram of tissue (％ID/g) at 1 h after injection. The radioactivity ratio of left ankle arthritic tissue to blood ( A/B) and to normal muscle ( A/M) was 4.40±0.22 and 1.65±0.07 respectively. MicroPET/CT imaging demonstrated that 18F-VUIIS1008 could specifically target and retained in the inflammation site. Conclusion 18 F-VUIIS1008 can be easily synthe-sized with high radiochemical purity and can clearly visualized in RA imaging with low background, suggesting its potential as a novel promising molecular probe targeting TSPO for RA PET imaging.
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Objective To investigate the significance of XAGE-1bmRNA expression in the blood specimens of patients with primary liver cancer, cirrhosis and benign liver diseases and in healthy individuals. Methods Venous blood specimens of patients with primary liver cancer (n= 125), cirrhosis (n= 23), benign liver diseases (n= 34) and healthy individuals (n = 41 ) were collected. XAGE-1b mRNA was detected by real-time fluorescence quantitative PCR. Results The expression levels of XAGE-1b mRNA in patients with primary liver cancer, cirrhosis, benign liver diseases and healthy in dividuals were 3.72 (0.93, 10.2) ×10-5, 0 (0, 0. 56) ×10-5, 0 (0, 0)×10-5, 0 (0, 0) ×10-5, respectively. The XAGE-1b mRNA expression in patients with primary liver cancer was obviously higher than the patients with cirrhosis, benign liver diseases and in healthy individuals. The expression levels for patients with cirrhosis was higher than patients with benign liver diseases and in healthy individuals. The expression levels for patients with benign liver diseases and healthy individuals were similar. With a optimal cut-off value of 8. 385 × 10-7 , the sensitivity, specificity, positive predictive value, and negative predictive value of XAGE-lb mRNA for diagnosing primary liver cancer were 80. 0%, 89.8%, 90.9% and 77.9% respectively. The positive rates for patients with primary liver cancer and cirrhosis were 80.0% and 30.4% respectively. Conclusion XAGE-lb mRNA can be used as a tumor marker for primary liver cancer. It contributes to the differentiation between primary liver cancer, cirrhosis and benign liver diseases.
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Forensic science is a cross discipline,involving both the subjects of natural sciences and the humanities & social sciences.It needs not only the application of forensic techniques and other theoretical results of natural sciences,but also be bounded by moral and ethical guidance.This paper discusses ethical issues involved in the teaching of forensic medicine in medical colleges,exploring the relationship between the teaching of forensic medicine and ethics,so as to promote the development of forensic science education.