scholarly journals Corrigendum: A Systematic Study of the Stability, Safety, and Efficacy of the de novo Designed Antimicrobial Peptide PepD2 and Its Modified Derivatives Against Acinetobacter baumannii

2022 ◽  
Vol 12 ◽  
Author(s):  
Sung-Pang Chen ◽  
Eric H-L Chen ◽  
Sheng-Yung Yang ◽  
Pin-Shin Kuo ◽  
Hau-Ming Jan ◽  
...  
2021 ◽  
Vol 12 ◽  
Author(s):  
Sung-Pang Chen ◽  
Eric H-L Chen ◽  
Sheng-Yung Yang ◽  
Pin-Shin Kuo ◽  
Hau-Ming Jan ◽  
...  

Searching for new antimicrobials is a pressing issue to conquer the emergence of multidrug-resistant (MDR) bacteria and fungi. Antimicrobial peptides (AMPs) usually have antimicrobial mechanisms different from those of traditional antibiotics and bring new hope in the discovery of new antimicrobials. In addition to antimicrobial activity, stability and target selectivity are important concerns to decide whether an antimicrobial peptide can be applied in vivo. Here, we used a simple de novo designed peptide, pepD2, which contains only three kinds of amino acid residues (W, K, L), as an example to evaluate how the residues and modifications affect the antimicrobial activity against Acinetobacter baumannii, stability in plasma, and toxicity to human HEK293 cells. We found that pepI2 with a Leu→Ile substitution can decrease the minimum bactericidal concentrations (MBC) against A. baumannii by one half (4 μg/mL). A D-form peptide, pepdD2, in which the D-enantiomers replaced the L-enantiomers of the Lys(K) and Leu(L) residues, extended the peptide half-life in plasma by more than 12-fold. PepD3 is 3-residue shorter than pepD2. Decreasing peptide length did not affect antimicrobial activity but increased the IC50 to HEK293 cells, thus increased the selectivity index (SI) between A. baumannii and HEK293 cells from 4.7 to 8.5. The chain length increase of the N-terminal acyl group and the Lys→Arg substitution greatly enhanced the hemolytic activity, hence those modifications are not good for clinical application. Unlike colistin, the action mechanism of our peptides relies on negatively charged lipids rather than lipopolysaccharides. Therefore, not only gram-negative bacteria but also gram-positive bacteria can be killed by our peptides.


2011 ◽  
Vol 6 (1) ◽  
pp. 39
Author(s):  

Background:Since the first reported use of percutaneous transluminal coronary angioplasty, advances in the interventional cardiology arena have been fast paced. Developers and clinicians are adapting from the learning curve awarded by the time-course of drug-eluting stent (DES) evolution. BioMime™ sirolimus-eluting stent (SES) is a step towards biomimicry. The stent is built on a strut of ultra-low thickness (65μm), a cobalt–chromium platform using an intelligent hybrid of closed and open cells allowing for morphology-mediated expansion. It employs a well-known antiproliferative – sirolimus – that elutes from a known biodegradable copolymer formulation within 30 days. The resultant stent demonstrates almost 100% endothelialisation at 30 days in preclinical models.Methods:The meriT-1 was a prospective, single-arm, single-centre trial to evaluate the safety and efficacy of BioMime SES in 30 patients with a single de novo lesion in native coronary arteries. The primary safety and efficacy end-points were major adverse cardiac events (MACE) at 30 days and in-stent late lumen loss at eight months, as measured using quantitative coronary angiographic (QCA) method. Secondary safety and efficacy end-points included MACE at one and two years and angiographic binary restenosis at eight-month angiographic follow-up. Other end-points included the occurrence of stent thrombosis at acute, subacute, late and very late periods and the percentage of diameter stenosis by QCA.Results:No MACE were observed and the median in-stent late luminal loss in 20 (67%) subjects studied by QCA was 0.15mm, with 0% binary restenosis at eight-month follow-up. No stent thrombosis was observed up to one-year follow-up.Conclusions:In comparison to currently available DES, BioMime SES appears to have a considerable scientific basis for prevention of neointimal proliferation, restenosis and associated clinical events.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Shin Irumagawa ◽  
Kaito Kobayashi ◽  
Yutaka Saito ◽  
Takeshi Miyata ◽  
Mitsuo Umetsu ◽  
...  

AbstractThe stability of proteins is an important factor for industrial and medical applications. Improving protein stability is one of the main subjects in protein engineering. In a previous study, we improved the stability of a four-helix bundle dimeric de novo protein (WA20) by five mutations. The stabilised mutant (H26L/G28S/N34L/V71L/E78L, SUWA) showed an extremely high denaturation midpoint temperature (Tm). Although SUWA is a remarkably hyperstable protein, in protein design and engineering, it is an attractive challenge to rationally explore more stable mutants. In this study, we predicted stabilising mutations of WA20 by in silico saturation mutagenesis and molecular dynamics simulation, and experimentally confirmed three stabilising mutations of WA20 (N22A, N22E, and H86K). The stability of a double mutant (N22A/H86K, rationally optimised WA20, ROWA) was greatly improved compared with WA20 (ΔTm = 10.6 °C). The model structures suggested that N22A enhances the stability of the α-helices and N22E and H86K contribute to salt-bridge formation for protein stabilisation. These mutations were also added to SUWA and improved its Tm. Remarkably, the most stable mutant of SUWA (N22E/H86K, rationally optimised SUWA, ROSA) showed the highest Tm (129.0 °C). These new thermostable mutants will be useful as a component of protein nanobuilding blocks to construct supramolecular protein complexes.


2020 ◽  
Vol 41 (Supplement_2) ◽  
Author(s):  
D.P Agip Fustamante ◽  
S Ortiz Cruces ◽  
S Camacho Freire ◽  
A Gutierrez Barrios ◽  
A Gomez Menchero ◽  
...  

Abstract Background The AngioSculpt X (Spectranetics) is a novel paclitaxel-coated scoring balloon with encouraging preliminary data for the treatment of in-stent restenosis or de novo complex lesions. Purpose To assess the safety and efficacy of real-world patients with in-stent restenosis (ISR) or de novo complex lesions (vessels <2.5 mm, calcified lesions, bifurcation lesions...) treated with the novel paclitaxel-coated scoring balloon. Methods A “real-world”, prospective registry from two centers was performed including consecutive patients presenting with ISR or de novo complex lesions and treated with AngioSculpt X. Their clinical data were prospectively registered. Major adverse cardiac events (MACE) were defined as a composite of cardiac death, stent thrombosis, nonfatal myocardial infarction, target lesion revascularization (TLR) and target vessel revascularization (TVR). Results Overall, 87 real-world patients and 93 lesions (73% male, 68±10 years, 46% smoker, 83% hypertensive, 62% diabetic, 71% hyperlipidemic, 35% LVEF <60% impairment) were enrolled in the study. Clinical presentation was stable angina in 19%, unstable angina in 33%, NSTEMI in 29% and STEMI in 5%. Radial access account 84%. The median fluoroscopy time was 17 (IQ range 10,0 - 37.5) min. De novo complex lesions were treated in 35% (n=32) while ISR in 63% (n=57), (Prior BMS 19%; Sirolimus DES 9%; Everolimus DES 26%; Biolimus/Anfilimus DES 20%; Zotarolimus DES 26%) with a median time to ISR of 3.6 (IQ range 1.1 - 10.7) years. Total stent length was 28±18 mm, with an overlap spot affected in 18%, and 27% had >1 treatment for ISR. The most frequent artery treated was left anterior descending (41%) followed by left circumflex (35%) and right coronary artery (17%). Quantitative coronary angiography reference diameter of lesions was 2.7±0.5 mm and length 9.0±4.8 mm, with a % stenosis of 75±20. Predilatation/postdilatation was performed in 60/24% respectively. Device diameter was 2.9±0.4 mm and length 13.6±3.9 mm, deployed at 16±3 atmospheres, with an inflation time of 33±16 seconds. The balloon/artery ratio was 0.99±0.03. Crossover was decided on 18 cases (19%) due to remaining intimal flap, but the success rate (residual stenosis <30%) was 100%. Intracoronary imaging technique was performed in 12% (OCT=7, IVUS=4). At 7±6 month follow-up, there were 10 MACE (cardiac death=1, nonfatal myocardial infarction =4, TLR=4 and TVR=1). Conclusions Paclitaxel-coated scoring balloon offers a safe and valuable treatment option for ISR and de novo complex lesions. Funding Acknowledgement Type of funding source: Public hospital(s). Main funding source(s): Juan Ramόn Jiménez University Hospital


2007 ◽  
Vol 20 (1) ◽  
pp. 27-36 ◽  
Author(s):  
Helio Tedesco-Silva ◽  
Stefan Vitko ◽  
Julio Pascual ◽  
Josette Eris ◽  
John C. Magee ◽  
...  

1972 ◽  
Vol 1 (13) ◽  
pp. 81 ◽  
Author(s):  
J.H. Van Oarschat ◽  
A. Wevers

Stability tests on the Europoort breakwaters, situated on a shallow foreshore, clearly demonstrated the effect of the foreshore configuration on the overall stability. The present article gives a descriptionof the stability experiments and the interpretation leading to general conclusions regarding foreshore effects in combination with hydraulic conditions such as wave period, water depth and wave height. Both regular and irregular waves have been used. The experiments, carried out in commission of the Netherlands Government Department of Public Works (Rijkswaterstaat) were of an applied nature and were not directed primarily to the systematic study of foreshore effects.


2021 ◽  
Vol 15 ◽  
Author(s):  
Jingru Ren ◽  
Chenxi Pan ◽  
Yuqian Li ◽  
Lanting Li ◽  
Ping Hua ◽  
...  

ObjectivePatients with Parkinson’s disease (PD) are commonly classified into subtypes based on motor symptoms. The aims of the present study were to determine the consistency between PD motor subtypes, to assess the stability of PD motor subtypes over time, and to explore the variables influencing PD motor subtype stability.MethodsThis study was part of a longitudinal study of de novo PD patients at a single center. Based on three different motor subtype classification systems proposed by Jankovic, Schiess, and Kang, patients were respectively categorized as tremor-dominant/indeterminate/postural instability and gait difficulty (TD/indeterminate/PIGD), TDS/mixedS/akinetic-rigidS (ARS), or TDK/mixedK/ARK at baseline evaluation and then re-assessed 1 month later. Demographic and clinical characteristics were recorded at each evaluation. The consistency between subtypes at baseline evaluation was assessed using Cohen’s kappa coefficient (κ). Additional variables were compared between PD subtype groups using the two-sample t-test, Mann–Whitney U-test or Chi-squared test.ResultsOf 283 newly diagnosed, untreated PD patients, 79 were followed up at 1 month. There was fair agreement between the Jankovic, Schiess, and Kang classification systems (κS = 0.383 ± 0.044, κK = 0.360 ± 0.042, κSK = 0.368 ± 0.038). Among the three classification systems, the Schiess classification was the most stable and the Jankovic classification was the most unstable. The non-motor symptoms questionnaire (NMSQuest) scores differed significantly between PD patients with stable and unstable subtypes based on the Jankovic classification (p = 0.008), and patients with a consistent subtype had more severe NMSQuest scores than patients with an inconsistent subtype.ConclusionFair consistency was observed between the Jankovic, Schiess, and Kang classification systems. For the first time, non-motor symptoms (NMSs) scores were found to influence the stability of the TD/indeterminate/PIGD classification. Our findings support combining NMSs with motor symptoms to increase the effectiveness of PD subtypes.


2014 ◽  
Vol 58 (10) ◽  
pp. 5809-5817 ◽  
Author(s):  
Sarah Forbes ◽  
Curtis B. Dobson ◽  
Gavin J. Humphreys ◽  
Andrew J. McBain

ABSTRACTMicrobicides (biocides) play an important role in the prevention and treatment of infections. While there is currently little evidence for in-use treatment failures attributable to acquired reductions in microbicide susceptibility, the susceptibility of some bacteria can be reduced by sublethal laboratory exposure to certain agents. In this investigation, a range of environmental bacterial isolates (11 genera, 18 species) were repeatedly exposed to four microbicides (cetrimide, chlorhexidine, polyhexamethylene biguanide [PHMB], and triclosan) and a cationic apolipoprotein E-derived antimicrobial peptide (apoEdpL-W) using a previously validated exposure system. Susceptibilities (MICs and minimum bactericidal concentrations [MBCs]) were determined before and after 10 passages (P10) in the presence of an antimicrobial and then after a further 10 passages without an antimicrobial to determine the stability of any adaptations. Bacteria exhibiting >4-fold increases in MBCs were further examined for alterations in biofilm-forming ability. Following microbicide exposure, ≥4-fold decreases in susceptibility (MIC or MBC) occurred for cetrimide (5/18 bacteria), apoEdpL-W (7/18), chlorhexidine (8/18), PHMB (8/18), and triclosan (11/18). Of the 34 ≥4-fold increases in the MICs, 15 were fully reversible, 13 were partially reversible, and 6 were nonreversible. Of the 26 ≥4-fold increases in the MBCs, 7 were fully reversible, 14 were partially reversible, and 5 were nonreversible. Significant decreases in biofilm formation in P10 strains occurred for apoEdpL-W (1/18 bacteria), chlorhexidine (1/18), and triclosan (2/18), while significant increases occurred for apoEdpL-W (1/18), triclosan (1/18), and chlorhexidine (2/18). These data indicate that the stability of induced changes in microbicide susceptibility varies but may be sustained for some combinations of a bacterium and a microbicide.


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