Development and evaluation of RADA-PDGF2 self-assembling peptide hydrogel for enhanced skin wound healing.

Background: Wound healing complications affect numerous patients each year, creating significant economic and medical challenges. Currently, available methods are not fully effective in the treatment of chronic or complicated wounds; thus, new methods are constantly sought. Our previous studies showed that a peptide designated as PDGF2 derived from PDGF-BB could be a promising drug candidate for wound treatment and that RADA16-I can serve as a release system for bioactive peptides in wound healing. Based on that, in this work, we designed a new self-assembling hydrogel RADA-PDGF2, connecting both peptides by a sequence specific for neutrophil elastase, and evaluated its activity in wound healing. Methods: The physicochemical properties of the designed scaffold were analyzed using transmission electron microscopy, atomic force microscopy, cryoSEM microscopies, and circular dichroism spectroscopy. The enzymatic cleavage was performed using human neutrophil elastase and monitored using high-performance liquid chromatography and MS spectroscopic techniques. The aforementioned techniques (HPLC and MS) were also used to assess the stability of the peptide in water and human plasma. The biological activity was analyzed on human skin cells using a colorimetric XTT test, collagen synthesis evaluation, and a migration assay. The biocompatibility was analyzed with LDH cytotoxicity assay and flow cytometric analysis of activation of immune cells. Finally, RADA-PDGF2 activity in wound healing was checked in a mouse dorsal skin injury model. Results: The analysis showed that RADA-PDGF2 can self-assemble, form a hydrogel, and release a bioactive sequence when incubated with human elastase. It shows pro-proliferative and pro-migratory properties and accelerates wound closure in the mouse model compared to RADA16-I. In addition, it is not cytotoxic to human cells and does not show immunogenicity. RADA-PDGF2 seems to be a promising drug candidate for wound management.

The genus Gautieria (Gomphales) in Europe and the Mediterranean Basin: a morphological and phylogenetic taxonomic revision.

Type material and additional collections of 11 taxa of Gautieria described in Europe and North Africa have been studied, namely G. dubia, G. graveolens, G. morchelliformis var. globispora, G. morchelliformis var. magnicellaris, G. morchelliformis var. morchelliformis, G. morchelliformis var. stenospora, G. otthii, G. pseudovestita, G. retirugosa, G. trabutii and G. villosa. At the same time, morphological and genetic studies on recent and herbarium collections from several European countries have been carried out. This enabled clarification of sections within Gautieria and differentiation of 28 taxa, of which 21 are new to science. However, the deeper relationships and nomenclature changes related to the phylogenetic position of the genus Gautieria within Gomphaceae will not be addressed in this study because they would require a more complete molecular analysis together with that of related genera, e.g., Gomphus, Turbinellus, and the four subgenera of Ramaria. In addition, a lectotype for G. villosa var. villosa and reference specimens for G. graveolens and G. morchelliformis var. morchelliformis are selected, and the new combination G. morchelliformis var. dubia is proposed. Detailed descriptions, macro- and microphotographs and distribution maps of all taxa are provided, as well as extensive information on their ecology, chorology and phylogeny. A key is included to facilitate identification of taxa. Citation: Vidal JM, Cseh P, Merényi Z, et al. 2023. The genus Gautieria (Gomphales) in Europe and the Mediterranean Basin: a morphological and phylogenetic taxonomic revision. Persoonia 50: 48 -122. https://doi.org/10.3767/persoonia.2023.50.03.

All-Optical Scheme for Generation of Isolated Attosecond Electron Pulses.

We theoretically propose an all-optical scheme for generation of isolated electron pulses with subfemtosecond durations for ultrafast electron microscopy and diffraction. The scheme is based on simultaneous longitudinal and transverse momentum modulation of freely propagating electrons at two distinct frequencies via ponderomotive interaction with tailored light fields of three phase-controlled laser pulses in vacuum. After a drift distance, an attosecond electron pulse train is formed with the individual pulses displaced in the transverse direction. Spatial filtering of the electron beam by an aperture leads to isolation of an individual attosecond pulse with a duration of <100 as. Subfemtosecond isolated electron pulses will enable direct space-time imaging of attosecond electronic dynamics in atoms, molecules, and solids with atomic spatial resolution, allowing us to directly observe phenomena such as electron tunneling or electron-electron interaction in strong laser fields of few-cycle laser pulses.

Optimization of cardiac resynchronization therapy based on speckle tracking.

OBJECTIVES: The aim of this study was to evaluate the correlation between the change in heart strains and the success rate of Cardiac Resynchronization Therapy (CRT) optimization. We further explored the benefit of speckle tracking for CRT. METHODS: In this prospective cohort study, CRT-Ds were implanted to 60 patients. 3 months later, the response was evaluated. In the non-responders, optimization based on speckle tracking was performed. The AV interval was optimized with respect to the quality of left ventricle filling and the VV interval was optimized with respect to heart strains. After a further three months, the optimization success was evaluated. RESULTS: Thirty-nine patients responded well to the initial CRT. The response was independent of etiology; the subsequent optimization was however more successful in dilated cardiomyopathy (DCM) (8 out of 9) than in ischemic heart disease (IHD) patients (3 out of 10 responded). The ejection fraction increase and area strain were the best predictors of NYHA improvement. CONCLUSION: AV and VV optimization in patients who do not respond well to initial CRT seems to have better results in patients suffering from DCM. Speckle tracking (specifically A-strain) may be used to guide CRT optimization (Tab. 2, Fig. 3, Ref. 22).

Nos3 Gene Rs1799983 and Rs2070744 Polymorphisms in Patients with Periodontal Disease.

Periodontal disease is a common oral disease. Inflammatory and immune responses to oral microorganisms initiate the development of periodontitis. Cigarette smoking is an important environmental risk factor for periodontitis. Another important inflammatory mediator is nitric oxide (NO). NO modulates vascular tone, microvascular permeability, leukocyte migration and oxidative activity, contributing to the direct killing of microorganisms. Several polymorphisms of the NOS3 gene have been detected, which may alter gene expression and NO synthesis. The aim of this study was to examine the association between the NOS3 rs1799983 and rs2070744 polymorphisms and periodontal disease. This study enrolled 200 patients with periodontal diseases (130 were non-smokers and 70 were smokers) and 160 control subjects (126 were non-smokers and 34 were smokers). Among the patients with periodontal disease, we observed a statistically increased frequency of patients with the CT genotype (TC vs. TT; 95%CI 1.83, OR 1.16-2.88, P = 0.011). There was a statistically significant increased frequency of CT genotype carriers among non-smoking patients with periodontal disease as compared with non-smoking controls, whereas there were no statistically significant differences between smoking patients with periodontal disease and smoking control subjects. The results of our study suggest an association between the NOS3 rs2070744 polymorphism and periodontal disease.

Simple technique for the compression of nanojoule pulses from few-cycle laser oscillator to 1.7-cycle duration via nonlinear spectral broadening in diamond.

We report on a simple approach for the compression of few-cycle laser pulses generated in an ultrafast laser oscillator to a duration corresponding to 1.7 cycles of near-infrared light (compression factor of 1.44) by nonlinear spectral broadening in diamond and subsequent dispersion compensation using chirped mirrors. After the spectral broadening, the pulse spectrum spans over almost an octave (580-1000 nm at the -10 dB level). The pulses are compressed by broadband-chirped mirrors and a wedge pair to a duration of 4.5 fs measured by spectral phase interferometry for direct electric-field reconstruction (SPIDER). The properties of the broadened spectrum and their modelling by numerical solution of a 1D nonlinear Schrödinger equation show that the main source of spectral broadening is self-phase modulation, whereas stimulated Raman scattering does not play a significant role.

Ponderomotive Generation and Detection of Attosecond Free-Electron Pulse Trains.

Atomic motion dynamics during structural changes or chemical reactions have been visualized by pico- and femtosecond pulsed electron beams via ultrafast electron diffraction and microscopy. Imaging the even faster dynamics of electrons in atoms, molecules, and solids requires electron pulses with subfemtosecond durations. We demonstrate here the all-optical generation of trains of attosecond free-electron pulses. The concept is based on the periodic energy modulation of a pulsed electron beam via an inelastic interaction, with the ponderomotive potential of an optical traveling wave generated by two femtosecond laser pulses at different frequencies in vacuum. The subsequent dispersive propagation leads to a compression of the electrons and the formation of ultrashort pulses. The longitudinal phase space evolution of the electrons after compression is mapped by a second phase-locked interaction. The comparison of measured and calculated spectrograms reveals the attosecond temporal structure of the compressed electron pulse trains with individual pulse durations of less than 300 as. This technique can be utilized for tailoring and initial characterization of suboptical-cycle free-electron pulses at high repetition rates for stroboscopic time-resolved experiments with subfemtosecond time resolution.

Ankle-brachial index in diabetic patients - which upper cut-off value is to be used?

OBJECTIVES: In diabetic patients, there is a discrepancy in guidelines for ankle-brachial index (ABI) screening for peripheral arterial disease (PAD). While diabetes organizations suggest the value of upper limit of normal ABI to be 1.3, cardiologists recommend 1.4. Also, guidelines recommend using the higher value of ankle pressure (HAP) but multiple recent studies propose the opposite (LAP). METHODS: In this prospective study, we performed ABI measurements in 62 diabetic patients. Results were calculated by comparing higher and lower values of ankle pressure to those of duplex ultrasound (stenosis ≥ 50 % was considered PAD). Special attention was paid to patients with high and non-measurable ABI. RESULTS: LAP ABI appears to be a preferable method for PAD screening in diabetics. The upper cut-off value of 1.4 yielded better results with sensitivity of 93 % and negative predictive value of 91 %. No limbs with ABI between 1.3 and 1.4 with significant stenosis were found. However, using HAP for the upper cut-off captured additional PAD patients. PAD was abundant among patients with high or non-measurable ABI. CONCLUSIONS: LAP should be used for assessing low ABI (cut-off 0.9) while HAP for detecting the abnormally high ABI. The preferable high ABI cut-off is 1.4. Condition with abnormally high or non-measurable ABI should be considered as PAD (Tab. 3, Ref. 22).

Acceleration of sub-relativistic electrons with an evanescent optical wave at a planar interface.

We report on a theoretical and experimental study of the energy transfer between an optical evanescent wave, propagating in vacuum along the planar boundary of a dielectric material, and a beam of sub-relativistic electrons. The evanescent wave is excited via total internal reflection in the dielectric by an infrared (λ = 2 µm) femtosecond laser pulse. By matching the electron propagation velocity to the phase velocity of the evanescent wave, energy modulation of the electron beam is achieved. A maximum energy gain of 800 eV is observed, corresponding to the absorption of more than 1000 photons by one electron. The maximum observed acceleration gradient is 19 ± 2 MeV/m. The striking advantage of this scheme is that a structuring of the acceleration element's surface is not required, enabling the use of materials with high laser damage thresholds that are difficult to nano-structure, such as SiC, Al2O3 or CaF2.

Novel approach to two-component speciation analysis. Spectrophotometric flow-based determinations of Fe(II)/Fe(III) and Cr(III)/Cr(VI).

The proposed approach to two-component speciation analysis relies on simultaneous application of two calibration methods to determination of two different forms of an analyte. One form is determined in extrapolative way, whereas the second form is determined in interpolative way, with the use of the same calibration graph, after appropriate chemical treatment, e.g. oxidation or reduction. The applicability of the approach has been verified on the examples of spectrophotometric determinations of Fe(II)/Fe(III) and Cr(VI)/Cr(III) using 1,10-phenanthroline and 1,5-diphenylcarbazide methods, respectively. In the above methods, ascorbic acid and Ce(IV) have been used to reduce Fe(III) to Fe(II) and to oxidize Cr(III) to Cr(VI), respectively. Lab-In-Syringe and SIA systems (for determination of iron and chromium species, respectively) have been applied to make the implementation of the proposed approach more convenient. The approach was verified on the example of determination of the analytes in synthetic and certified reference materials of ground and waste water samples. Using the developed methods, Fe(II)/Fe(III) and Cr(VI)/Cr(III) were determined within the concentration ranges of 0.06-4.0/0.06-3.0 and 0.03-0.5/0.05-7.0mgL-1, with precision (RSD, %) less than 3.8/2.0 and 2.2/6.0, and accuracy (RE, %) better than 2.9/4.3 and 6.8/5.2, respectively. The detection limits (mgL-1) are 0.02/0.02 and 0.01/0.02 for determination of both forms of iron and chromium, respectively. The applicability of the approach has been checked by analysis of artesian water (Fe(II)/Fe(III)) and post-production waste samples (Cr(III)/Cr(VI)).

Optical gating and streaking of free electrons with sub-optical cycle precision.

The temporal resolution of ultrafast electron diffraction and microscopy experiments is currently limited by the available experimental techniques for the generation and characterization of electron bunches with single femtosecond or attosecond durations. Here, we present proof of principle experiments of an optical gating concept for free electrons via direct time-domain visualization of the sub-optical cycle energy and transverse momentum structure imprinted on the electron beam. We demonstrate a temporal resolution of 1.2±0.3 fs. The scheme is based on the synchronous interaction between electrons and the near-field mode of a dielectric nano-grating excited by a femtosecond laser pulse with an optical period duration of 6.5 fs. The sub-optical cycle resolution demonstrated here is promising for use in laser-driven streak cameras for attosecond temporal characterization of bunched particle beams as well as time-resolved experiments with free-electron beams.

Structural studies of the formation of lipoplexes between siRNA and selected bis-imidazolium gemini surfactants.

Dicationic (gemini) surfactants are agents that can be used for the preparation of stable complexes of nucleic acids, particularly siRNA for therapeutic purposes. In this study, we demonstrated that bis-imidazolium gemini surfactants with variable lengths of dioxyalkyl linker groups (from dioxyethyl to dioxydodecyl) and dodecyl side chains are excellent for the complexation of siRNA. All of these compounds effectively complexed siRNA in a charge ratio range (p/n) of 1.5-10. The low resolution structure of siRNA oligomers was characterised by small angle scattering of synchrotron radiation (SR-SAXS) and ab initio modelling. The structures of the formed complexes were also analysed using SR-SAXS, circular dichroism studies and electrophoretic mobility tests. The most promising agents for complexation with siRNA were the surfactants that contained dioxyethyl and dioxyhexyl spacer groups.

Evaluation of a flow cytometric assay for the confirmation of heparin-induced thrombocytopenia.

INTRODUCTION: Heparin-induced thrombocytopenia (HIT) is an immune-mediated thrombocytopenia associated with heparin therapy. The diagnosis consists of a combination of pretest probability and laboratory testing. The routinely available laboratory antigen binding assays for the detection of specific antibodies have a low HIT-positive predictive value; therefore, to exclude false-positive results, one of the functional assays should be performed. Functional assays evaluate the ability of heparin/PF4 antibodies to activate the platelets. The aim of our study was to validate the flow cytometric functional assay, based on the use of anti-CD61 and anti-CD62 antibodies, as a suitable diagnostic test for HIT. METHODS: Sera from patients with a clinical suspicion of HIT were previously analyzed with screening IgG-specific ELISA, and 41 of those which were positive were selected for the functional assay. RESULTS: Our results were compared to another functional assay - the HIPA (heparin-induced platelet aggregation assay). The diagnostic specificity of the flow cytometric assay was calculated based on HIPA results and was 83%. CONCLUSION: Performing this functional test after the screening assay could significantly improve the specificity of HIT testing as heparin/PF4 antibodies are often not clinically significant.

Single peak parameters technique for simultaneous measurements: Spectrophotometric sequential injection determination of Fe(II) and Fe(III).

Spectrophotometric sequential injection system (SI) is proposed to automate the method of simultaneous determination of Fe(II) and Fe(III) on the basis of parameters of a single peak. In the developed SI system, sample and mixture of reagents (1,10-phenanthroline and sulfosalicylic acid) are introduced into a vessel, where in an acid environment (pH≅3) appropriate compounds of Fe(II) and Fe(III) with 1,10-phenanthroline and sulfosalicylic acid are formed, respectively. Then, in turn, air, sample, EDTA and sample again, are introduced into a holding coil. After the flow reversal, a segment of air is removed from the system by an additional valve and as EDTA replaces sulfosalicylic acid forming a more stable colorless compound with Fe(III), a complex signal is registered. Measurements are performed at wavelength 530 nm. The absorbance measured at minimum of the negative peak and the area or the absorbance measured at maximum of the signal can be used as measures corresponding to Fe(II) and Fe(III) concentrations, respectively. The time of the peak registration is about 2 min. Two-component calibration has been applied to analysis. Fe(II) and Fe(III) can be determined within the concentration ranges of 0.04-4.00 and 0.1-5.00 mg L(-1), with precision less than 2.8% and 1.7% (RSD), respectively and accuracy better than 7% (RE). The detection limit is 0.04 and 0.09 mg L(-1) for Fe(II) and Fe(III), respectively. The method was applied to analysis of artesian water samples.

Interaction of two imidazolium gemini surfactants with two model proteins BSA and HEWL.

Gemini surfactants and their interactions with proteins have gained considerable scientific interest, especially when amyloidogenic proteins are taken into account. In this work, the influence of two selected dicationic (gemini) surfactants (3,3'-[1,8-(2,7-dioxaoctane)]bis(1-dodecylimidazolium) chloride and 3,3'-[1,12-(2,11-dioxadodecane)]bis(1-dodecylimidazolium) chloride) on two model proteins, bovine serum albumin (BSA) and hen egg white lysozyme (HEWL), have been investigated. A pronounced and sophisticated influence on BSA structure has been revealed, including a considerable change of protein radius of gyration as well as substantial alteration of its secondary structure. Radius of gyration has been found to rise significantly with addition of surfactants and to fall down for high surfactants concentration. Similarly, a remarkable fall of secondary structure (α-helix content) has been observed, followed by its partial retrieval for high surfactants concentration. A strong aggregation of BSA has been observed for a confined range of surfactants concentrations as well. In case of HEWL-gemini system, on the other hand, the protein-surfactant interaction was found to be weak. Molecular mechanisms explaining such behaviour of protein-surfactant systems have been proposed. The differences of properties of both studied surfactants have also been discussed.

Evaluation of blood culture media for the detection of fungi.

The aim of this study was to compare the utility of BACTEC™ Mycosis-IC/F (Mycosis), BACTEC™ Plus Aerobic/F (Aerobic), and BACTEC™ Plus Anaerobic/F (Anaerobic) media in the detection of fungi from simulated (obtained by the inoculation of tested media first with sterile sheep's blood and subsequently with one of 60 clinical yeast isolates) and clinical blood samples, taken during routine diagnostic examination in two hospitals. All tested strains grew on Mycosis as well as Aerobic bottles, and the time to detection obtained for Mycosis was significantly shorter (p < 0.05). The largest differences in the time to positivity was found for Candida glabrata and Cryptococcus neoformans, when Mycosis preceded Aerobic in 20-48 h (mean 35.5 h) and 0.7-64 h (mean 24 h), respectively. On the contrary, C. krusei were detected earlier in Aerobic media. In clinical samples, the detection of C. glabrata was also significantly faster in Mycosis than in Aerobic (29.22 ± 11.48 h compared to 86 ± 40 h). The media complement each other and, in 45% of clinical examination sets, a single positive medium was noted (25% in Mycosis and 19% in Aerobic). The study proved that both Aerobic and Mycosis media serve as the correct condition for the culture of fungi and that they varied significantly in the detection time of clinically important species. This result could suggest that the simultaneous use of Aerobic as well as Mycosis media may improve the time of diagnosis in many patients, especially those infected with C. glabrata or C. neoformans.

Consensus Document on Intermittent Claudication from the Central European Vascular Forum (C.E.V.F.)-3rd revision (2013) with the sharing of the Mediterranean League of Angiology and Vascular Surgery, and the North Africa and Middle East Chapter of International Union of Angiology.

This paper is the review of the Consensus Document on Intermittent Claudication of the Central European Vascular Forum (CEVF), published in 2008, and and shared with the North Africa and Middle East Chapter of International Union of Angiology and the Mediterranean League of Angiology and Vascular Surgery. The Document presents suggestions for general practitioners and vascular specialists for more precise and appropriate management of PAD, particularly of intermittent claudication, and underlines the investigations that should be required by GPs and what the GP should expect from the vascular specialist (angiologist, vascular surgeon). The idea of the Faculty is to produce a short document, which is an easy reference in daily clinical practice, both for the GPs and vascular specialists.

Interaction of bovine serum albumin (BSA) with novel gemini surfactants studied by synchrotron radiation scattering (SR-SAXS), circular dichroism (CD), and nuclear magnetic resonance (NMR).

The interaction of three dicationic (gemini) surfactants-3,3'-[1,6-(2,5-dioxahexane)]bis(1-dodecylimidazolium) chloride (oxyC2), 3,3'-[1,16-(2,15-dioxahexadecane)]bis(1-dodecylimidazolium) chloride (oxyC12), and 1,4-bis(butane)imidazole-1-yl-3-dodecylimidazolium chloride (C4)--with bovine serum albumin (BSA) has been studied by the use of small-angle X-ray scattering (SAXS), circular dichroism (CD), and (1)H nuclear magnetic resonance diffusometry. The results of CD studies show that the conformation of BSA was changed dramatically in the presence of all studied surfactants. The greater decrease (from 56 to 24%) in the α-helical structure of BSA was observed for oxyC2 surfactant. The radii of gyration estimated from SAXS data varied between 3 and 26 nm for the BSA/oxyC2 and BSA/oxyC12 systems. The hydrodynamic radius of the BSA/surfactant system estimated from NMR diffusometry varies between 5 and 11 nm for BSA/oxyC2 and 5 and 8 nm for BSA/oxyC12.