ABSTRACT
Natural antimicrobial peptides have strong bactericidal activities. An obstacle of the development of antimicrobial peptides resides in the difficulty of developing peptides with high biocompatibility. In this study, molecular dynamics analysis was employed to assess the structural characteristics and biological activities of peptides. A (RXKY)2(YRY)2 structure was used as a template to design an antimicrobial peptide RIKL of high-efficiency and low-toxicity, where X represents Ile and Y represents Leu. The secondary structure of the antimicrobial peptide was detected by circular dichroism (CD), and the structures of RIKL in water and in POPC/POPG membrane environment were measured using molecular dynamics. The biological activity of RIKL was further studied by assessing its antimicrobial activity, hemolytic activity, eukaryotic cytotoxicity, and salt ion stability. CD results showed that RIKL presented an α-helical structure in a simulated bacterial membrane environment. Molecular dynamics simulation predicted that the secondary structure of RIKL could be partly retained in water and POPG environment, while this secondary structure was weakened in the POPC environment. Antimicrobial test suggested that RIKL had high antimicrobial activities, and the geometric mean of the Minimum Inhibitory Concentration (MIC) was 3.1 μmol/L. The hemolysis indicated that RIKL had no hemolytic activity within the detection range, and cytotoxicity test suggested the cytotoxicity of RIKL was low. Stability test showed that RIKL maintained antimicrobial activities under different pH, serum concentrations and salt environments. Based on the above results, RIKL has high cell selectivity and has the potential as a highly effective antibacterial drug.
Subject(s)
Amino Acid Sequence , Antimicrobial Peptides/pharmacology , Microbial Sensitivity Tests , Protein Structure, SecondaryABSTRACT
Objective To explore the effect of low concentration 5-fluorouracil combined with triamcinolone acetonide on rabbit ear hypertrophic scar model.Methods White rabbits post-traumatic scars were randomly divided into A,B,C and D groups,each group contained 18 cases.Group A was given triamcinolone acetonide and low concentration 5-fluorouracil,Group B was given low concentration 5-fluorouracil,Group C was given triamcinolone acetonide and Group D was used as the control group.The dynamic changes of the scar were observed by naked eyes,hematoxylin-eosin (HE) staining and van Gieson (VG) staining through microscope.Vascular endothelial growth factor (VEGF) and CD34 were detected and compared within 4 groups by immunohistochemical staining.Results We successfully established a rabbit ear scar model.It was observed that the scars of Groups A,B and C had been shorter and flatter than Group D,close to the normal tissue.In HE and VG staining,the number of fibroblasts,inflammatory cells,blood vessels in groups A,B and C had been decreased,compared with Group D.Immunohistochemical results showed that the positive rates of VEGF and CD34 from the most to the lest were Groups D,B,C and A.The scar proliferation index from the most to the lest were Groups D,B,C and A.Conclusions The effect of low concentration 5-fluorouracil in treatment of the rabbit ear hypertrophic scar is better than that of triamcinolone acetonide.Low concentration 5-fluorouracil combined with triamcinolone acetonide has a synergistic effect in treatment of hypertrophic scar,which has better effect than that of low concentration 5-fluorouracil or triamcinolone acetonide alone.
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Precision medicine is a new developing area of medical research and clinical practice, which is stemmed from the urgent need for high-profile medical health care and fast emergence of exquisite biological and medical technologies.Precision medicine, mainly based on the individualized molecular medicine and sophisticated medical techniques, offers multiple dimensional imaging examinations and biological molecular assays to make subsequent therapeutic strategies much more optimized to the personal disease characteristics than the traditional regimes, hence pursuing maximized efficacy and minimized side effects.The precision medicine in China is stepping into a vigorously developing stage after its first official initiation.This review summarized the development and program design of precision medicine in China to shed light on this growingly progressing area.
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Human genetic resource is a special kind of resource,which is an important media through which people understand about their life. Its protection and utilization is particularly significant.To understand the current situation,the author analyzed the international cooperative research projects that involved human genetic resource and approved during 1999 and 2010 at Chinese Academy of Medicine. Problems were identified and suggestions were proposed so as to provide reference for proper management.
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This article described that the biology and medicine research is an important field in the international cooperation of science and technology.Meantime,by analysis on the achievements of the international cooperation from 2005 in Chinese Academy of Medical Sciences.it was shown that the intemational cooperation plays very important rule in promoting the research development in the biological and medical field.Also some principles of the international cooperation of science and technology were put forward in this article.