Design and characterization of new antimicrobial peptides derived from aurein 1.2 with enhanced antibacterial activity.

Antimicrobial peptides (AMPs) are promising alternative agents for treating multidrug-resistant bacterial infections. Aurein 1.2 is a natural 13-amino acid AMP with antibacterial activity against Gram-positive bacteria. In this study, we designed three novel AMPs: aurein M1 (A10W), aurein M2 (D4K, E11K), and aurein M3 (A10W, D4K, E11K) to analyze the effect of Trp substitution and enhancement of positive charge on the activity of aurein 1.2. The AMP probability, physicochemical properties, secondary and tertiary structures, and amphipathic structure were predicted by various bioinformatics tools. After the synthesis of the peptides, their antibacterial activity, hemolysis, cytotoxicity, and structural analysis were assayed. Compared to the selectivity of aurein 1.2, the selectivity of aurein M2 and M3 with a net positive charge of +5 was improved 11.30- and 8.00-fold against Gram-positive and -negative bacteria, respectively. The hemolytic activity of aurein M2 was lower than that of aurein 1.2 and M3, while the higher percentage of human fibroblast cells were alive in the presence of aurein M3. Also, the MICs of aurein M3 toward Staphylococcus aureus and Escherichia coli at the physiologic salt were ≤16, which is recommended as a promising candidate for clinical investigation. Circular dichroism analysis indicated an alpha-helical structure in the peptide analogs that is similar to aurein 1.2 in the presence of 10 mM SDS. Therefore, increasing positive charge can be used successfully as an approach for improving the potency and selectivity of AMPs. Moreover, the beneficial effect of Trp substitution depends on its position and the sequence of peptides.

Psychological Consequences of Breast Cancer in Iran: A Meta-Analysis.

BACKGROUND: Breast cancer is known as one of the most common cancers among women and has severe psychological effects. This study aimed to identify the psychological consequences of breast cancer in previous studies based on meta-analysis. METHODS: Meta-analytic procedures were conducted by Prisma guidelines. A literature search was conducted by using following electronic databases including scientific information databases (SID), Magiran, Medlib, ScienceDirect, PubMed, Google Scholar, Web of Science, Scopus, CINAHL and Medline from 1991 through 2017 regarding the psychological consequences associated with breast cancer in Iran. The content of all articles was evaluated by the Prisma checklist and analyzed meta-analysis in CMA software. RESULTS: The final synthesis was carried out on 56 quantitative studies. Considering the findings of meta-analysis of the psychological consequences of patients with breast cancer in seven classes, anxiety (ES=-0.76), body image (ES=0.199), coping strategies (ES= 0.214), depression (ES=-0.700), fatigue (ES=0.322), quality of life (ES= 0.428), and sexual function (ES=0.355) were achieved. CONCLUSION: Based on the results of the high level of psychological consequences of breast cancer in women with breast cancer, it is necessary to formulate appropriate therapeutic protocols in order to adjust the psychological consequences.