Preparation of 89Zr-labeled mesenchymal stem cells and PET monitoring in mice with systemic lupus erythematosus / 中华核医学与分子影像杂志

Objective:To label mesenchymal stem cells (MSCs) with 89Zr-oxine complex, and assess its characteristics of PET imaging in systemic lupus erythematosus (SLE) model (MRL/lpr mice). Methods:SLE mice were screened by 18F-FDG PET imaging. 89Zr-oxine was prepared and used for labeling MSCs (10 6 MSCs and 1 MBq 89Zr-oxine). 89Zr-oxine-labeled MSCs (0.2 MBq) were injected into MRL/lpr mice and BALB/c mice (each n=5) via tail vein at a dose of 1.2×10 6 cells per mouse, and followed with microPET imaging in vivo at 2 h, 6 h, 1 d, 3 d, 7 d, 10 d and 14 d after injection. The percentage activity of injection dose per gram of tissue (%ID/g) was calculated. Independent-sample t test was used to analyze the data. Results:MSCs was successfully labeled with 89Zr-oxine, with the labeling efficiency of 20% and cell viability >90%. MicroPET imaging showed that MSCs were mainly distributed in lungs and the liver sites at 2 h after injection. The number of MSCs homing to kidneys of MRL/lpr mice ( n=5) increased significantly 24 h after the injection, and the renal uptake of MSCs in MRL/lpr mice was much higher than that in BALB/c mice ((8.28±1.27) vs (4.33±0.94) %ID/g; t=3.54, P=0.024). The renal uptake increased firstly and then decreased and then leveled off, indicating MSCs homing to kidneys. Conclusions:A method for 89Zr-oxine labeling of MSCs is successfully established. 89Zr-labeled MSCs can home to kidneys of SLE mice. PET imaging of 89Zr-labeled MSCs can be effectively used to explore the in vivo distribution and migration behavior of transplanted MSCs during the treatment of diseases such as SLE.

Preparation of N- 18F-fluoroethyl-tofacitinib and its application in the imaging of rheumatoid arthritis / 中华核医学与分子影像杂志

Objective:To synthesize N- 18F-fluoroethyl-tofacitinib, and explore its feasibility in the diagnosis of rheumatoid arthritis (RA). Methods:The " two-step method" was used to modify tofacitinib with 18F-fluoroethyl, and the labeling rate and radiochemical purity of the probe were measured by high performance liquid chromatography (HPLC), and the stabilities of the probe in vivo and in vitro were investigated. BALB/c mice (normal group; n=3) and collagen-induced arthritis (CIA) model mice (CIA group; n=3) were injected with N- 18F-fluoroethyl-tofacitinib and CIA model mice injected with tofacitirrib and N- 18F-fluoroethyl-tofacitinib were as blocking group ( n=3). All mice underwent microPET imaging and the percentage injection dose per gram of tissue (%ID/g) and the uptake ratio of inflamed joints to muscle (T/M) were calculated. One-way analysis of variance and the least significant difference (LSD) t test were used to analyze the data. Results:The synthesis time of N- 18F-fluoroethyl-tofacitinib was about 120 min, with the yield approximately 1%, the specific activity >13.6 GBq/μmol, and the radiochemical purity >99%. After the probe incubated with PBS, plasma or in vivo for 2 h, the radiochemical purity was still more than 95%. MicroPET imaging showed that 30 min after injection, the uptake of N- 18F-fluoroethyl-tofacitinib in the inflamed joints of CIA group was higher than that of normal group and blocking group ((10.22±1.64), (2.71±0.26) and (2.81±0.33) %ID/g; F=58.26, t values: 7.83, 7.67, P values: 0.001, 0.002). The T/M of CIA group was also higher than that of normal group and blocking group (24.73±5.77, 2.75±1.36 and 2.89±0.54; F=40.64, t values: 6.42, 6.53, P values: 0.003, 0.003). Conclusions:N- 18F-fluoroethyl-tofacitinib is successfully prepared and it is stable in vitro with good imaging performance in vivo. It may be used in clinic for the diagnosis of RA.

MicroPET and biodistribution of 68Ga-labeled human epidermal growth factor receptor 2 binding affibody imaging probe / 中华核医学与分子影像杂志

Objective:To prepare a 68Ga labeled human epidermal growth factor receptor 2 (HER2) affibody 68Ga-1, 4, 7-triazacylononane-1, 4, 7-triacetic acid (NOTA)-maleimide (MAL)-Cysteine (Cys)-Glycine-Glycine-Glycine-Arginine-Aspartic acid-asparagine-HER 2: 342 affibody (GGGRDN-ZHER 2: 342)( 68Ga-MZHER), and evaluate its biodistribution and microPET characteristics. Methods:NOTA-MAL-Cys-GGGRDN-ZHER 2: 342 conjugate was labeled with 68Ga in one step. Radiochemical purity, radiolabeling yield and stability in vitro were analyzed. Normal mice ( n=24) were scarified at 15, 30, 60 and 120 min postinjection (1.85 MBq 68Ga-MZHER) to measure radioactive counts (percentage activity of injection dose per gram of tissue (%ID/g)) in main organs. Biodistribution and kinetics were evaluated by dynamic microPET in mice. Ovarian cancer (SKOV-3) models were established and microPET was performed at 30, 60 and 120 min postinjection of radiotracer. After administration of unlabeled Cys-ZHER 2: 342 peptide (10 mg/kg body weight) for 30 min, 68Ga-MZHER was injected into mice and PET images were acquired at 60 min postinjection. Region of interest (ROI) was drawn to access time-activity curve (TAC) in main organs and tumor. Six normal mice were used for the safety study. Results:68Ga-MZHER was synthesized in about 15 min with the yields more than 90%, and radiochemical purity more than 95%. The radiochemical purity was also determined to be more than 95% after being stored for 120 min at room temperature. Predominant uptake of 68Ga-MZHER was in the kidneys, and was cleared rapidly in normal tissues except the kidney. At 15 min postinjection, the renal uptake value was (106.36±15.74) %ID/g, then gradually increased with time, up to (145.15±28.04) %ID/g (60 min), and decreased to (86.12±22.75) %ID/g after 120 min postinjection. The blood pharmacokinetic of the probe in mice was fit with the two-compartment model. MicroPET imaging in mice bearing HER2 positive SKOV-3 tumors showed that the xenografts were clearly visualized with good contrast to normal tissue. The uptakes in tumors was determined to be (11.26±0.50), (12.27±1.13) and (12.65±0.89) %ID/g at 30, 60 and 120 min postinjection. Block experiment showed that the corresponding values decreased to (1.25±0.28) %ID/g at 60 min postinjection. Safety studies showed that after injection of 68Ga-MZHER for 30 d, the mice survived and no obvious abnormalities were observed in the main organs as shown in pathological results. Conclusions:68Ga-MZHER can be successfully labeled by one-step method. The 68Ga-MZHER probe owns the advantages of favorable imaging properties, convenient preparation, excellent stability, safety, rapid clearance in the blood, which support its application for further research.

Identification and Characterization of Two New S-Adenosylmethionine-Dependent Methyltransferase Encoding Genes Suggested Their Involvement in Stipe Elongation of Flammulina velutipes

Two new SAM-dependent methyltransferase encoding genes (fvsmt1 and fvsmt2) were identified from the genome of Flammulina velutipes. In order to make a comprehensive characterization of both genes, we performed in silico analysis of both genes and used qRT-PCR to reveal their expression patterns during the development of F. velutipes. There are 4 and 6 exons with total length of 693 and 978 bp in fvsmt2 and fvsmt1, respectively. The deduced proteins, i.e., FVSMT1 and FVSMT2 contained 325 and 230 amino acids with molecular weight 36297 and 24894 Da, respectively. Both proteins contained a SAM-dependent catalytic domain with signature motifs (I, p-I, II, and III) defining the SAM fold. SAM-dependent catalytic domain is located either in the middle or at the N-terminal of FVSMT2 and FVSMT1, respectively. Alignment and phylogenic analysis showed that FVSMT1 is a homolog to a protein–arginine omega-N-methyltransferase, while FVSMT2 is of cinnamoyl CoA O-methyltransferase type and predicted subcellular locations of these proteins are mitochondria and cytoplasm, respectively. qRT-PCR showed that fvsmt1 and fvsmt2 expression was regulated in different developmental stages. The maximum expression levels of fvsmt1 and fvsmt2 were observed in stipe elongation, while no difference was found in mycelium and pileus. These results positively demonstrate that both the methyltransferase encoding genes are involved in the stipe elongation of F. velutipes.

Observation of effect of red lip defect repair using orbicularis oris muscles pedicle island flap disc / 中国基层医药

Objective To explore the effect of red lip defect repair using orbicularis oris muscles pedicle island flap disc.Methods 100 cases of unilateral pure red lip defect 1/3-2/3,lip lines full of patients were selected as the research subjects.They were randomly divided into two groups,50 cases in each group.Group A treated with debridement surgery to repair.Group B received red lip flap to promote repair treatment.The treatment effect of the two groups, satisfaction, lip survival rate and the degree of obvious scars were compared.Results he operation effect of the two groups was good.The satisfaction rates of group A and group B were 94.00% and 96.00%,respectively.For the lip shape treatment satisfaction, the difference was no statistically significant (P>0.05).The patients of the two groups with lip all alive, and 1 patient in group A with obvious scar, the scar was not obvious in group B.Conclusion For patients with red lip defect, take orbicularis oris muscles pedicle island flap of the oral mucosa or red lip flap to promote repair treatment has relatively significant clinical efficacy, with easy operation, less influence on the patients with facial form, it is worthy of popularizing.