OBJECTIVEThis study aimed to evaluate the biological characteristics of a human specifically targeted antimi- crobial peptide C16LL-37 against Streptococcus mutans (S. mutans).

METHODSIn this study, an antimicrobial peptide LL-37, a peptide derived from CSP(C16) (S. mutans competence stimulating peptide), and recombinant peptide C16LL-37 were synthesized by Fmoc-chemistry-based strategy. The selectivity and antibacterial activity of C16LL-37 were identified by the colony counting method on microbial culture plates. After treatment of C16LL-37 at 32 µmol · L⁻¹, the morphological changes in S. mutans were observed by using scanning electron microscopy (SEM). In addition, enzyme-linked immunosorbent assay was used to evaluate the hemolytic activity and antibacterial activity of C16LL-37 under different conditions.

RESULTS1) The minimum inhibitory concentration of C16LL-37 was 16 µmol · L⁻¹, and the minimum bactericidal concentration was 64 μmol ·L⁻¹. 2) The survival rate of S. mutans was 3.46% after C16LL-37 treatment at 64 µmo-L⁻¹ for 30 min, whereas it was 0% at 64 µmol · L⁻¹ for 60 min. The survival rates of four other kinds of bacteria were more than 60% at any time (P < 0.05). 3) The morphological change in S. mutans was observed after C16LL-37 treatment at 32 µmol · L⁻¹ by using SEM. S. mutans presented an irregular shape, rough surface, and evident splitting. 4) The hemolysis rate of C16LL-37 (≤ 64 µmol · L⁻¹) was less than 0.33%. 5) This study showed no significant in- fluence on the antibacterial activity of C16LL-37 under different conditions, such as temperature, pH, salinity, and trypsin at low concentration (P > 0.05).

CONCLUSIONC16LL-37 exhibited obvious specificity for S. mutans, strong antibacterial activity, low toxicity, and high stability. Thus, C16LL-37 has good potential in caries research and clinical application.

Anti-Infective Agents ; pharmacology ; Antimicrobial Cationic Peptides ; pharmacology ; Bacterial Proteins ; Dental Caries ; Enzyme-Linked Immunosorbent Assay ; Humans ; Microbial Sensitivity Tests ; Microscopy, Electron, Scanning ; Peptides ; Streptococcus mutans ; drug effects

To improve the phenomenon of low participation and lack of innovation in education mode in general medical education elective courses, we have applied "creating significant learning experiences" to the design and implementation of medical general education curriculum, starting from six dimensions of learning including basic knowledge, application, synthesis, humanistic dimension, humanistic care, and learning to learn, setting learning goals, developing assessment tools and finally choosing teaching methods, thus forming a closed-loop teaching. And through the curriculum reform, collection of feedback and collation of data, the teaching activities designed according to this method fully meet and serve the teaching purposes, and assessment methods become more diverse and the content is more comprehensive, which reflects the multi-dimensional evaluation of the needs of general education.

Objective To evaluate the efficacy of bare mental stent (BMS) and covered stent (CS) in the treatment of complete central venous occlusive disease (CVOD) in hemodialysis patients.Methods A total of 66 cases of CVOD who have been treated by endovascular methods successfully in the First Affiliated Hospital of Sun Yat-sen University from Jan 2015 to Jan 2017 were enrolled in this study.According to the type of stent,the patients were divided into two groups,BMS group (n=46)and CS group (n=20).The demographic data,clinical signs and symptoms,and pre-procedure and post-procedure imaging data were followed up and recorded.The primary patency rates were calculated at 1,3,6,9,and 12 months.Results The related symptoms were improved within 2 day post-procedure.The primary patency rates of BMS group in 1,3,6,9 and 12 months were 97.83％,95.65％,69.56％,41.3％,and 34.78％ respectively.The rates of CS group were 100％,100％,95％,65％,and 60％respectively.They did not reached statistical significance for primary patency rates between two groups in 1,3,and 6 months (P ＞ 0.05 respectively).However,from 9 months after procedure,it began to show the significant difference between two groups (P ＜ 0.05).The median patency time of the CS group was (10.30±5.32) months,while BMS group was (8.52±0.49) months.The difference between the two groups was statistically significant (P=0.046).Conclusions Stent implantation for complete occlusion of central venous in hemodialysis patients can get credible effect.The use of CS for CVOD provides superior patency as well as patency time in long period after procedure as compared with BMS.

Objective To explore the expression of circ_0006692 in NSCLC and its relation with clinicopathological characteristics and related mechanism. Methods We collected 50 pairs of NSCLC tissues and adjacent tissues. The expression of circ_0006692 was detected by qRT-PCR and its relation with clinicopathological features was analyzed. We constructed lung cancer A549 cell line with circ_0006692 overexpression and knockdown. Cell proliferation, migration and invasion were detected by MTS, colony forming, wound healing and Transwell invasion assays. qRT-PCR and Western blot were used to detect the effect of circ_0006692 expression change on EMT-related gene expression. Results The expression of circ_0006692 in NSCLC was significantly higher than that in adjacent tissues (P < 0.05). The expression level of circ_0006692 was closely related to tumor size, TNM stage and pulmonary membrane invasion (P < 0.05). circ_0006692 knockdown inhibited cell proliferation, invasion and metastasis, while its overexpression promoted cell proliferation, invasion and metastasis. circ_0006692 knockdown inhibited the expression of EMT-related genes CDH2 and MMP7 in A549 cells and promoted the expression of CDH1. Conclusion The upregulated expression of circ_0006692 in NSCLC is closely related to tumor size, TNM stage and pulmonary membrane invasion. circ_0006692 expression could regulate the proliferation, invasion, metastasis and EMT progression of lung cancer A549 cells.

BACKGROUND: Patients with mass-forming pancreatitis (MFP) or pancreatic ductal adenocarcinoma (PDAC) presented similar clinical symptoms, but required different treatment approaches and had different survival outcomes. This meta-analysis aimed to compare the diagnostic performance of contrast-enhanced ultrasound (CEUS) and contrast-enhanced computed tomography (CECT) in differentiating MFP from PDAC. METHODS: A literature search was performed in the PubMed, EMBASE (Ovid), Cochrane Library (CENTRAL), China National Knowledge Infrastructure (CNKI), Weipu (VIP), and WanFang databases to identify original studies published from inception to August 20, 2021. Studies reporting the diagnostic performances of CEUS and CECT for differentiating MFP from PDAC were included. The meta-analysis was performed with Stata 15.0 software. The outcomes included the pooled sensitivity, specificity, positive likelihood ratio (+LR), negative likelihood ratio (-LR), diagnostic odds ratio (DOR), and summary receiver operating characteristic (SROC) curves of CEUS and CECT. Meta-regression was conducted to investigate heterogeneity. Bayesian network meta-analysis was conducted to indirectly compare the overall diagnostic performance. RESULTS: Twenty-six studies with 2115 pancreatic masses were included. The pooled sensitivity and specificity of CEUS for MFP were 82% (95% confidence interval [CI], 73%-88%; I2  = 0.00%) and 95% (95% CI, 90%-97%; I2  = 63.44%), respectively; the overall +LR, -LR, and DOR values were 15.12 (95% CI, 7.61-30.01), 0.19 (95% CI, 0.13-0.29), and 78.91 (95% CI, 30.94-201.27), respectively; and the area under the SROC curve (AUC) was 0.90 (95% CI, 0.87-92). However, the overall sensitivity and specificity of CECT were 81% (95% CI, 75-85%; I2  = 66.37%) and 94% (95% CI, 90-96%; I2  = 74.87%); the overall +LR, -LR, and DOR values were 12.91 (95% CI, 7.86-21.20), 0.21 (95% CI, 0.16-0.27), and 62.53 (95% CI, 34.45-113.51), respectively; and, the SROC AUC was 0.92 (95% CI, 0.90-0.94). The overall diagnostic accuracy of CEUS was comparable to that of CECT for the differential diagnosis of MFP and PDAC (relative DOR 1.26, 95% CI [0.42-3.83], P  > 0.05). CONCLUSIONS CEUS and CECT have comparable diagnostic performance for differentiating MFP from PDAC, and should be considered as mutually complementary diagnostic tools for suspected focal pancreatic lesions.
Humans ; Contrast Media ; Bayes Theorem ; Tomography, X-Ray Computed/methods* ; Pancreatic Neoplasms/diagnostic imaging* ; Carcinoma, Pancreatic Ductal/diagnostic imaging* ; Sensitivity and Specificity ; Pancreatitis/diagnostic imaging* ; Ultrasonography/methods*