Magnetic Particle Imaging: From Tracer Design to Biomedical Applications in Vasculature Abnormality.

Magnetic particle imaging (MPI) is an emerging non-invasive tomographic technique based on the response of magnetic nanoparticles (MNPs) to oscillating drive fields at the center of a static magnetic gradient. In contrast to magnetic resonance imaging (MRI), which is driven by uniform magnetic fields and projects the anatomic information of the subjects, MPI directly tracks and quantifies MNPs in vivo without background signals. Moreover, it does not require radioactive tracers and has no limitations on imaging depth. This article first introduces the basic principles of MPI and important features of MNPs for imaging sensitivity, spatial resolution, and targeted biodistribution. The latest research aiming to optimize the performance of MPI tracers is reviewed based on their material composition, physical properties, and surface modifications. While the unique advantages of MPI have led to a series of promising biomedical applications, recent development of MPI in investigating vascular abnormalities in cardiovascular and cerebrovascular systems, and cancer are also discussed. Finally, recent progress and challenges in the clinical translation of MPI are discussed to provide possible directions for future research and development.

Molecular Prognostic Value of Circulating Epstein-Barr Viral DNA in Nasopharyngeal Carcinoma: A Meta-Analysis of 27,235 Cases in the Endemic Area of Southeast Asia.

Aims: This meta-analysis evaluated the value of using Epstein-Barr virus (EBV) DNA titers as a predictive factor in assessing the clinical course of nasopharyngeal carcinoma (NPC) patients in Southeast Asia. Methods: A systematic search was performed using PubMed, the Cochrane Library, and Embase online databases. Eligible studies with complete baseline information and extractable hazard ratios (HRs), 95% confidence intervals (CIs), and other details were included in this analysis. All pooled statistics were calculated using RevMan 5.3 software with inverse variance methods, forest plots, or funnel plots directly; the results were analyzed both in toto and by subgroups using meta-regression and sensitivity analyses. Results: Forty studies involving 27,235 subjects were included in this meta-analysis. When the recommended EBV DNA viral cutoff values of 2,000, 0, and 0 copies/mL were used for the pretreatment, mid treatment, and post treatment groups, respectively, all values above these cutoffs were associated with at least a 2.5-fold increased risk of death compared with patients with lower levels of EBV DNA (HRs and 95% CIs were 2.47 [2.10-2.89], 2.67 [1.50-4.75], and 5.25 [3.58-7.71], respectively, p < 0.05). This finding could also explain heterogeneities among the studies. Conclusion: Higher pretreatment, mid-treatment, and post-treatment EBV DNA levels were all significantly correlated with poor outcomes for patients afflicted with NPCs. Further investigations of EBV DNA levels, combined with addressing tumor size, lymph nodes, metastases stages, are needed to determine whether they can be used as clinical guidelines for diagnosis and treatment.

iTRAQ-based quantitative proteomic analysis of differentially expressed proteins in chemoresistant nasopharyngeal carcinoma.

Nasopharyngeal carcinoma (NPC) is a highly prevalent disease in Southeast Asia. The disease is typically diagnosed in the later stages, and chemotherapy resistance often causes treatment failure. To investigate the underlying mechanisms of drug resistance, we searched for chemoresistant-associated proteins in NPC and drug-resistant NPC cell lines using isobaric tags for relative and absolute quantitation combined with nano liquid chromatography-tandem mass spectrometry. The chemoresistant NPC cell lines CNE1DDP and CNE2DDP were resistant to 1 mg/L cisplatin, had resistant indexes of 4.58 and 2.63, respectively, and clearly grew more slowly than the NPC cell lines CNE1 and CNE2. Using three technical replicates, we identified 690 nonredundant proteins, 56 of which were differentially expressed in both groups of cell lines (CNE1 vs. CNE1DDP and CNE2 vs. CNE2DDP). Gene Ontology, KEGG pathway, and miRNA analyses and protein-protein interactions of differentially expressed proteins showed that proteins TRIM29, HSPB1, CLIC1, ANXA1, and STMN1, among others, may play a role in the mechanisms of chemoresistance in clinical therapy. The chemotherapy-resistant proteomic profiles obtained may allow the identification of novel biomarkers for early detection of chemoresistance in NPC and other cancers.

Hemolytic Escherichia coli Inhibits Swarming and Differentiation of Proteus mirabilis.

Swarming is a hallmark of Proteus mirabilis, whether common gram-negative bacilli affect the swarming of P. mirabilis is still unclear. In this study, we found that P. mirabilis swarming was inhibited by Escherichia coli ATCC25922, but was not affected by Klebsiella pneumoniae, Acinetobacter baumannii, or Pseudomonas aeruginosa strains. The migration distance of P. mirabilis when mixed with E. coli ATCC25922 was strongly reduced, and the inhibition of the swarming of P. mirabilis by E. coli ATCC25922 was dependent on cell density. In addition, initiation of P. mirabilis swarming was delayed by E. coli ATCC25922. Among clinical isolates, including gram-negative bacilli and gram-positive cocci, only hemolytic E. coli inhibited the swarming of P. mirabilis. In summary, hemolytic E. coli inhibited the swarming and differentiation of P. mirabilis.