96 research outputs found

    De Novo Design and Synthesis of Ultra-Short Peptidomimetic Antibiotics Having Dual Antimicrobial and Anti-Inflammatory Activities

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    Ravichandran N. Murugan, Mija Ahn, Eunha Hwang, Ji-Hyung Seo, Chaejoon Cheong, Jeong Kyu Bang, Division of Magnetic Resonance, Korea Basic Science Institute, Ochang, Chung-Buk, Republic of KoreaBinu Jacob, Song Yub Shin, Department of Bio-Materials, Graduate School and Department of Cellular and Molecular Medicine, School of Medicine, Chosun University, Gwangju, Republic of KoreaHoik Sohn, Department of Chemistry and Biochemistry, University of Texas at Austin, Austin, Texas, United States of AmericaHyo-Nam Park, Jae-Kyung Hyun, Division of Electron Microscopic Research, Korea Basic Science Institute, Daejeon, Republic of KoreaEunjung Lee, Ki-Woong Jeong, Yangmee Kim, Department of Bioscience and Biotechnology, Institute of SMART Biotechnology, Konkuk University, Seoul, Republic of KoreaKy-Youb Nam, Bioinformatics and Molecular Design Research Center, Yonsei University Research Complex, Seoul, Republic of KoreaBackground: Much attention has been focused on the design and synthesis of potent, cationic antimicrobial peptides (AMPs) that possess both antimicrobial and anti-inflammatory activities. However, their development into therapeutic agents has been limited mainly due to their large size (12 to 50 residues in length) and poor protease stability.-- Methodology/Principal Findings: In an attempt to overcome the issues described above, a set of ultra-short, His-derived antimicrobial peptides (HDAMPs) has been developed for the first time. Through systematic tuning of pendant hydrophobic alkyl tails at the N(π)- and N(τ)-positions on His, and the positive charge of Arg, much higher prokaryotic selectivity was achieved, compared to human AMP LL-37. Additionally, the most potent HDAMPs showed promising dual antimicrobial and anti-inflammatory activities, as well as anti–methicillin-resistant Staphylococcus aureus (MRSA) activity and proteolytic resistance. Our results from transmission electron microscopy, membrane depolarization, confocal laser-scanning microscopy, and calcein-dye leakage experiments propose that HDAMP-1 kills microbial cells via dissipation of the membrane potential by forming pore/ion channels on bacterial cell membranes. -- Conclusion/Significance: The combination of the ultra-short size, high-prokaryotic selectivity, potent anti-MRSA activity, anti-inflammatory activity, and proteolytic resistance of the designed HDAMP-1, -3, -5, and -6 makes these molecules promising candidates for future antimicrobial therapeutics.This work was supported in part by the Korea Basic Science Institute's research program grants T33418 (J.K.B) and T33518 (J-k.H.), and the Korea Research Foundation, funded by the Korean Government (KRF-2011-0009039 to S.Y.S.). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.ChemistryBiochemistryEmail: [email protected] (JKB)Email: [email protected] (SYS

    Association Between Inappropriateness of Left Ventricular Mass and Left Ventricular Diastolic Dysfunction: A Study Using the Tissue Doppler Parameter, E/E'

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    Background and Objectives: The structural significance of the inappropriateness of left ventricular mass (iLVM) is known to be an important prognostic factor for cardiovascular events; however, the functional changes associated with iLVM have not been established. This study was performed to determine if diastolic dysfunction is associated with iLVM using a tissue Doppler technique. Subjects and Methods: Three hundred sixty consecutive subjects, including 221 hypertension patients from the echocardiography database, were analyzed. Regarding the appropriateness of left ventricular (LV) mass, an observed/predicted ratio of IV mass (OPR) > 130% was defined as inappropriate. Echocardiographic parameters, including early diastolic peak velocity (E)/late diastolic peak velocity (A), deceleration time (DT), isovolumetric relaxation time (IVRT), and E/early mitral annulus velocity (E'), were compared between the appropriate LV mass (aLVM) group and the iLVM group. Results: Among transmitral flow parameters, only the E velocity was negatively correlated with the OPR when adjusted for age (adjusted r=-0.107, p=0.04). Based on multiple regression analysis, the OPR (??=0.163, p=0.003), as well as age (??=0.286, p=0.0001), systolic blood pressure (??=0.120, p=0.019), fasting blood glucose (??=0.098, p=0.042), and male gender (??=0.157, p=0.002) were independent factors determining E/E'. The cholesterol level was not an independent factor (??=-0.059, p=0.355). In the iLVM group (n=105), the adjusted E/E' was higher than in the aLVM group (n=255; 11.7 ?? 3.4 vs. 10.8 ?? 3.1, p=0.02), while the peak E flow velocity was significantly lower than in the aLVM group (70.9 ?? 15.1 vs. 75.5 ?? 17.6, p=0.03). Conclusion: Inappropriateness of LV mass is independently associated with increased E/E'. Thus, E/E' may be a useful parameter for the evaluation of diastolic dysfunction. Copyright ?? 2009 The Korean Society of Cardiology

    Low Frequency and Variability of FLT3 Mutations in Korean Patients with Acute Myeloid Leukemia

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    FLT3 mutations are common genetic changes, and are reported to have prognostic significance in acute myeloid leukemia (AML). The FLT3 internal tandem duplication (ITD) and the D835 activating mutation in the tyrosine kinase domain (TKD) were analyzed by polymerase chain reaction (PCR) in the genomic DNA of Korean patients with AML at diagnosis and during follow-up. There were 226 patients with AML enrolled between March 1996 and August 2005. The incidence of ITD and TKD at diagnosis was 13% (29/226) and 3% (6/226). When compared to Western and other Asian patients with AML, Korean patients had a lower frequency by about two-thirds of ITD and TKD. Among the non-M3 cases (N=203), the patients with an ITD had a significantly shorter event-free survival when compared with those without an ITD (p=0.0079). Among 54 relapsed patients, 9 patients had the FLT3 ITD at diagnosis. Six patients demonstrated a reappearance of the ITD and 3 patients remained negative at relapse. One patient, among 45 patients who relapsed, had a negative baseline ITD but acquired a de novo ITD at relapse. There were 101 samples from 93 patients in remission; they were all negative for an ITD. Among 34 patients who failed to achieve a remission, five patients had a persistent ITD and one patient had a de novo ITD. These results support the concept of resistance of FLT3 ITD leukemic clones to chemotherapy. Therefore, effective therapy with FLT3 targeting agents may improve the prognosis of non-M3 AML patients with the FLT3 mutation

    Systematic functional analysis of kinases in the fungal pathogen Cryptococcus neoformans

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    Cryptococcus neoformans is the leading cause of death by fungal meningoencephalitis; however, treatment options remain limited. Here we report the construction of 264 signature-tagged gene-deletion strains for 129 putative kinases, and examine their phenotypic traits under 30 distinct in vitro growth conditions and in two different hosts (insect larvae and mice). Clustering analysis of in vitro phenotypic traits indicates that several of these kinases have roles in known signalling pathways, and identifies hitherto uncharacterized signalling cascades. Virulence assays in the insect and mouse models provide evidence of pathogenicity-related roles for 63 kinases involved in the following biological categories: growth and cell cycle, nutrient metabolism, stress response and adaptation, cell signalling, cell polarity and morphology, vacuole trafficking, transfer RNA (tRNA) modification and other functions. Our study provides insights into the pathobiological signalling circuitry of C. neoformans and identifies potential anticryptococcal or antifungal drug targets.OAIID:RECH_ACHV_DSTSH_NO:T201615370RECH_ACHV_FG:RR00200001ADJUST_YN:EMP_ID:A003535CITE_RATE:11.329FILENAME:4. ncomms12766.pdfDEPT_NM:농생명공학부EMAIL:[email protected]_YN:YFILEURL:https://srnd.snu.ac.kr/eXrepEIR/fws/file/fce63c4a-7de7-4741-996f-d8d24af38905/linkCONFIRM:

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    The liquid jet breakup has been studied in the areas such as aerosols, spray and combustion. The breakup depends on several physical parameters such as the jet velocity, the nozzle inner diameter, and the density ratio of the water to the jet. This paper deals with characteristics of the jet breakup according to the jet velocity and the nozzle diameter. In order to consider only hydrodynamic factors, all the experiments were conducted in non-boiling conditions. The jet behavior in the water pool was observed by high-speed camera and PIV technique. For the condition of the inner diameter of 6.95 mm and the jet velocity of 2.8 m/s, the debris size of 22 mm gave the largest mass fraction, 39%. For higher jet velocity of 3.1 m/s, the debris size of 14 mm gave the largest mass fraction, 36%. For the nozzle with inner diameter of 9.30 mm, the debris size distribution was different. For jet velocity of 2.8 m/s and 3.1 m/s, the debris size with the largest mass fraction was found to be 14 mm. It was identified that the debris size decreased as the diameter or the jet velocity increased.clos

    Bioassay-Guided Isolated Compounds from Morinda officinalis Inhibit Alzheimer’s Disease Pathologies

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    Due to the side effects of synthetic drugs, the therapeutic potential of natural products for Alzheimer’s disease (AD) has gained interest. Morinda officinalis has demonstrated inhibitory effects on geriatric diseases, such as bone loss and osteoporosis. However, although AD is a geriatric disease, M. officinalis has not been evaluated in an AD bioassay. Therefore, M. officinalis extracts and fractions were tested for AD-related activity, including inhibition of acetylcholinesterase (AChE), butyrylcholinesterase (BChE), β-site amyloid precursor protein cleaving enzyme 1 (BACE1), and advanced glycation end-product (AGE) formation. A bioassay-guided approach led to isolation of 10 active compounds, eight anthraquinones (1–8), one coumarin (9), and one phytosterol (10), from n-hexane and ethyl acetate fractions of M. officinalis. The five anthraquinones (4–8) were stronger inhibitors of AChE than were other compounds. Compounds 3 and 9 were good inhibitors of BChE, and compounds 3 and 8 were good inhibitors of BACE1. Compounds 1–5 and 7–9 were more active than the positive control in inhibiting AGE formation. In addition, we first suggested a structure-activity relationship by which anthraquinones inhibit AChE and BACE1. Our findings demonstrate the preventive and therapeutic efficacy of M. officinalis for AD and its potential use as a natural alternative medicine

    An Improved Prediction Model for Ovarian Cancer Using Urinary Biomarkers and a Novel Validation Strategy

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    This study was designed to analyze urinary proteins associated with ovarian cancer (OC) and investigate the potential urinary biomarker panel to predict malignancy in women with pelvic masses. We analyzed 23 biomarkers in urine samples obtained from 295 patients with pelvic masses scheduled for surgery. The concentration of urinary biomarkers was quantitatively assessed by the xMAP bead-based multiplexed immunoassay. To identify the performance of each biomarker in predicting cancer over benign tumors, we used a repeated leave-group-out cross-validation strategy. The prediction models using multimarkers were evaluated to develop a urinary ovarian cancer panel. After the exclusion of 12 borderline tumors, the urinary concentration of 17 biomarkers exhibited significant differences between 158 OCs and 125 benign tumors. Human epididymis protein 4 (HE4), vascular cell adhesion molecule (VCAM), and transthyretin (TTR) were the top three biomarkers representing a higher concentration in OC. HE4 demonstrated the highest performance in all samples withOC(mean area under the receiver operating characteristic curve (AUC) 0.822, 95% CI: 0.772–0.869), whereas TTR showed the highest efficacy in early-stage OC (AUC 0.789, 95% CI: 0.714–0.856). Overall, HE4 was the most informative biomarker, followed by creatinine, carcinoembryonic antigen (CEA), neural cell adhesion molecule (NCAM), and TTR using the least absolute shrinkage and selection operator (LASSO) regression models. A multimarker panel consisting of HE4, creatinine, CEA, and TTR presented the best performance with 93.7% sensitivity (SN) at 70.6% specificity (SP) to predict OC over the benign tumor. This panel performed well regardless of disease status and demonstrated an improved performance by including menopausal status. In conclusion, the urinary biomarker panel with HE4, creatinine, CEA, and TTR provided promising efficacy in predicting OC over benign tumors in women with pelvic masses. It was also a non-invasive and easily available diagnostic tool
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