Objective: To evaluate the performance of 5T magnetic resonance imaging (MRI) in visualizing dental pulp and periodontal ligament (PDL) tissues in vivo in the young adult population, thereby providing a basis for the application of high-field MRI technology in clinical oral examinations. Methods: The study was approved by the Ethics Committee of the hospital. A total of 15 healthy volunteers (413 permanent teeth altogether) were recruited and underwent full-mouth 5T MRI scans. Among them, six volunteers (168 permanent teeth) also received both 3T MRI and cone-beam computed tomography (CBCT) scans. Two dental specialists independently evaluated the imaging quality of the dental pulp and PDL on the images using a 5-point Likert scale and recorded the number of detectable root canals for each tooth. Inter-rater agreement was assessed using weighted kappa statistics and intraclass correlation coefficient (ICC). Non-parametric tests were employed to compare differences in imaging performance among different tissue structures, tooth positions, and imaging modalities. Results: 5T MRI can achieve in vivo imaging for most dental pulp tissues and partial periodontal membrane structures. There was a high level of agreement between the two raters in their imaging scores for the dental pulp and PDL (dental pulp κ = 0.934, PDL κ = 0.737). The imaging scores for dental pulp were significantly higher than those for PDL (P < 0.001), and the scores for molar dental pulp were lower than those for premolars and anterior teeth. In the multimodal comparison involving six volunteers, the raters showed good consistency in scoring dental pulp and PDL imaging across 5T MRI, 3T MRI, and CBCT, as well as in root canal counts (5T MRI for dental pulp κ = 0.971, 3T MRI for dental pulp κ = 0.933, CBCT for dental pulp κ = 0.964; 5T MRI for PDL κ = 0.625, 3T MRI for PDL κ = 0.667, CBCT for PDL κ = 0.571; ICC for root canal counts all ≥ 0.990). The imaging scores for dental pulp and PDL using 5T MRI were significantly higher than those using 3T MRI (dental pulp: P < 0.001; PDL: P = 0.022), but there was no statistically significant difference in the detection rate of the number of root canals between the two (P > 0.05). Although the imaging scores for dental pulp and PDL as well as the detection rate of the number of root canals with 5T MRI were inferior to those with CBCT (dental pulp: P < 0.001; PDL: P = 0.02; number of root canals: P < 0.05), 5T MRI can truly achieve "direct imaging" of these two soft tissues. Conclusion 5T MRI enables effective in vivo direct imaging of dental pulp and PDL tissues in the young adult population, indicating its potential clinical application value in the diagnosis and treatment of pulp and periodontal diseases.

Objective: To investigate the causal association between amino acids and the primary malignant bone tumor and its underlying mechanism. Methods: Genome-wide association study (GWAS) data of glycine, serine, arginine, glutamine, methionine, and leucine was sourced from the IEU OpenGWAS database and the GWAS Catalog. GWAS data of primary malignant bone tumor were obtained from the FinnGen database. Using each of the six amino acids as the exposure and primary malignant bone tumor as the outcome, two-sample Mendelian randomization (MR) analysis was performed with the inverse-variance weighted method as the primary approach. Multivariable MR analysis was employed to control for collinearity among amino acids. Sensitivity analyses were conducted using Cochran's Q test, MR-Egger regression and the MR Steiger test. The Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis and protein-protein interaction network analysis were explored to explore potential mechanisms and identify key genes. Results: MR analysis results indicated a statistically significant causal association between glycine and primary malignant bone tumor (OR=1.719, 95%CI: 1.083-2.728). No significant causal associations were found for the other five amino acids (all P>0.05). Multivariable MR analysis revealed that, after adjusting for the other five amino acids, confirmed a positive causal association between glycine and primary malignant bone tumor (OR=1.512, 95%CI: 1.125-2.031). Sensitivity analyses revealed no significant heterogeneity, horizontal pleiotropy, or reverse causality (all P>0.05). Genes associated with both glycine metabolism and primary malignant bone tumor were enriched in the JAK-STAT signaling pathway, with serine hydroxymethyltransferase 2 (SHMT2) identified as a key gene. Conclusion Higher glycine levels may increase the risk of primary malignant bone tumor via the SHMT2-JAK-STAT pathway.

We chose Gaussia luciferase (Gluc), a secreted luciferase gene as reporter to real-time detect and dynamically monitor hydrodynamic injection gene expression. First, we constructed an expression vector pAAV2neo-Gluc. Then Huh7 and HepG2 cells were transfected with pAAV2neo-Gluc and the activity of Gluc in the supernatant and cell lysates were assayed. Results showed that the Gluc activity in the supernatant was about 100 higher than that in cell lysates, indicating the expressed Gluc existing mainly as a secreted form as reported. Live bioluminescence imaging of mice hydrodynamic injected pAAV2neo-Gluc showed whole body distribution, while the pAAV2neo-Fluc primarily located in the liver. Then we injected different doses of pAAV2neo-Gluc into mice by tail-vein hydrodynamic injection, took minor amount of blood from mice tails at different time points and measured the luciferase activity to investigate dynamic changes of Gluc expression and secretion in vivo. The results suggested that the time courses of Gluc expression were highly consistent among each dose groups. The luciferase activity in blood could be detected as early as 2 h after injection, reached the peak at about 10 h and gradually decreased from then on. The expression level of Glue was positively correlated with the dose of injected plasmid DNA. To further detect the assay sensitivity of the ex vivo Gluc measurement method, we investigated three additional groups of mice injected with lower doses of 0.001 microg, 0.01 microg and 0.1 microg pAAV2neo-Gluc respectively. Results revealed that activity of Gluc in blood could be detected even at dose as low as 0.001 microg DNA, suggesting the assay sensitivity was extremely high. In conclusion, a real-time ex vivo detection method of dynamically monitoring of gene expression in vivo by hydrodynamic injection can be a valuable means for the study of gene expression regulation in vivo.
Animals ; Gene Expression Regulation ; Genes, Reporter ; genetics ; Genetic Therapy ; Hep G2 Cells ; Humans ; Hydrodynamics ; Injections, Intravenous ; Liver ; metabolism ; Luciferases ; administration & dosage ; biosynthesis ; genetics ; pharmacokinetics ; Male ; Mice ; Mice, Inbred BALB C ; Transfection

Objective To design and express a novel peptide based on ricin toxin antibody in E. coli, and to evaluate its biological activity. Methods Based on the crystal structure of ricin toxin A chain (RTA) and the RTA-rRNA interact in the complex model, the steric conformation of RTA was theoretical modeled and its functional domain was preliminarily determined. The humanized single-domain RTA antibody was designed rationally by computer-guidod molecular design method. Its coding sequence was ob- tained by overlapping extension PCR, and cloned into the pET-32a vector. The fusion protein was then ex-pressed in E. coli BL21 (DE3), identified by Western blot, and purified with Ni-NTA agarose. The binding and neutralizing activity of this novel peptide for riein was evaluated by competitive ELlSA assay and MTT assay. Results A recombinant human single-domain antibody expressing a polypeptide against RTA in the CDR3 loop was designed. The fusion protein was successfully expressed in E. coll. The purified protein can bind to ricin, and neutralize its activity in SP2/0 viability assay. Conclusion The success of the novel pep-tide based on riein toxin antibody provides a novel method to develop new generation of ricin antagonists.