Search

The failures of anti-β-amyloid immunotherapies suggested that the very low fraction of injected antibodies reaching the brain parenchyma due to the filtering effect of the BBB may be a reason for the lack of therapeutic effect. However, there is no treatment, as yet, for the amyotrophic lateral sclerosis (ALS) despite substantial evidence existing of the involvement of TDP-43 protein in the evolution of ALS. To circumvent this filtering effect, we have developed a novel approach to facilitate the penetration of antibody fragments (Fabs) into the brain parenchyma. Leveraging the homing properties of endothelial progenitor cells (EPCs), we transfected, ex vivo, such cells with vectors encoding anti-β-amyloid and anti-TDP43 Fabs turning them into an "antibody fragment factory". When injected these cells integrate into the BBB, where they secrete anti-TDP43 Fabs. The results showed the formation of tight junctions between the injected engineered EPCs and the unlabeled resident endothelial cells. When the EPCs were further modified to express the anti-TDP43 Fab, we could observe integration of these cells into the vasculature and the secretion of Fabs. Results confirm that production and secretion of Fabs at the BBB level leads to their migration to the brain parenchyma where they might exert a therapeutic effect. [ABSTRACT FROM AUTHOR]

Graphene oxide (GO) is not only an intermediate in top-down graphene preparation, but it is also acknowledged for its convenient application when the hydrophobicity of graphene is a drawback. Its preparation through the wet exfoliation of graphite inevitably leads to a product lacking several of the outstanding features of graphene. The destroyed graphene structure can be at least partially reconstructed by thermal and/or wet chemical reduction. Thermally reduced graphene oxide (TRGO) was obtained by mild heat treatment (300 °C) in argon, while chemically reduced graphene oxide (CRGO) was prepared by using a green reagent, ascorbic acid (AA). The parent GO and the two GO derivatives were compared by thermogravimetric analysis coupled with mass spectroscopy and Raman spectroscopy. Both reductive treatments resulted in enhanced thermal stability and higher C/O ratio. Although the chemical reduction with AA was more efficient in the elimination of the O functionalities, it also resulted in significant fragmentation of the graphene-like platelets. [ABSTRACT FROM AUTHOR]

Abstract Recurrent spreading depolarizations occur in the cerebral cortex from minutes up to weeks following acute brain injury. Clinical evidence suggests that the immediate reduction of cerebral blood flow in response to spreading depolarization importantly contributes to lesion progression as the wave propagates over vulnerable tissue zones, characterized by potassium concentration already elevated prior to the passage of spreading depolarization. Here we demonstrate with two-photon microscopy in anesthetized mice that initial vasoconstriction in response to SD triggered experimentally with 1 M KCl is coincident in space and time with the large extracellular accumulation of potassium, as shown with a potassium indicator fluorescent dye. Moreover, pharmacological manipulations in combination with the use of potassium-sensitive microelectrodes suggest that large-conductance Ca2+-activated potassium (BK) channels and L-type voltage-gated calcium channels play significant roles in the marked initial vasoconstriction under elevated baseline potassium. We propose that potassium efflux through BK channels is a central component in the devastating neurovascular effects of spreading depolarizations in tissue at risk. Graphical abstract Unlabelled Image Highlights • Potassium wave of spreading depolarization (SD) initiates arteriolar constriction. • BK channels are significantly implicated in SD-related vasoconstriction. • L-type voltage-gated Ca2+ channels partially mediate SD-related vasoconstriction. • K+ efflux during SD manifests through BK channels to a significant degree. [ABSTRACT FROM AUTHOR]

Abstract By the advent of continuous pharmaceutical manufacturing, fast and accurate characterization of product quality has become of a major interest. Although it also promotes the real-time release testing approach, so far mainly content uniformity studies were performed by near-infrared (NIR) spectroscopy. This paper proposes the simultaneous application of NIR and Raman spectroscopy to nondestructively analyze the critical quality attributes of continuously produced tablets in a real-time release testing procedure. A face-centered composite design was applied to determine the impact of lubrication and compression force on the properties of a tablet formulation containing caffeine, glucose-monohydrate and magnesium stearate and to provide a systematic comparison of the applicability of spectroscopic methods. Quantitative methods were developed to evaluate different lubrication approaches in a continuous blending and tableting line. The simultaneous application of NIR and Raman spectroscopy revealed that NIR spectroscopy is more suitable to follow the changes of compression force, while Raman spectroscopy could be successfully applied for the detection of overlubrication. The presented approach can be a part of a comprehensive real-time release strategy, where NIR and Raman spectroscopy provide complementary information about multiple critical quality attributes, such as content uniformity, tablet hardness, friability and dissolution. Graphical abstract Unlabelled Image [ABSTRACT FROM AUTHOR]

Type II restriction endonucleases and modification DNA-methyltransferases are key instruments of genetic engineering. Recently the number of proteins assigned to this group exceeds 8500. Subtype IIC organizes bifunctional endonuclease-methyltransferase enzymes and currently consists of 16 described members. Here we present phylogenetic tree of 22 new potential bifunctional endonucleases. The majority of them are thought to be fusions of a restriction nuclease with a DNA-methyltransferase and a target recognition subunit of type I restriction-modification systems (R-M-S structure). A RM.AloI isoschizomer from Prevotella copri DSM-18205, PcoI, has been cloned, purified and its REase activity demonstrated. It cuts DNA in magnesium-dependent manner and demonstrates high affinity to DNA, which probably reflects its mechanism of action. This work provides additional proves that gene fusion might play an important role in evolution of restriction-modification systems and other DNA-modifying proteins. [ABSTRACT FROM AUTHOR]

It seems clear when investigating sign language and verbal languages from the perspective of embodied cognition hypotheses based cognitive linguistics that both kinds of languages are natural. In this approach, the semantics of sign and verbal languages are equally assigned by the brain-body-environment interaction. The cognitive consequences of the numerous interactions with the world, and the cognitive ability to simulate those interactions in off-line mode, de-coupled from the environment, are crucial for gaining an understanding of communication and meaning. This paper throws light on the connection between the body and language from the perspective of embodied cognitive science, and argues that situated conceptualization is the most suitable thesis to understand the semantics of both sign and verbal languages. An additional aim of the paper is to help to reduce prejudice against deaf people by demonstrating that deaf sign language is far from being primitive, and moreover, it will show that sign language can facilitate a better understanding of how verbal languages really work. [ABSTRACT FROM AUTHOR]

Hyperspectral imaging was applied to provide quantitative spatial information about pharmaceutical samples. The aim was to characterize the distribution of active pharmaceutical ingredient (API) in manufactured samples quantitatively. Two kind of API, imipramine and spironolactone were applied in three conventional and two continuous processing technologies. The homogeneity of distributions of 10% API was determined through Raman maps applying macropixel analysis method. Non-overlapping macropixel analysis (Poole-index) and calculation of distributional homogeneity indices (DHIs) were compared as a measure of homogeneity. Non-overlapping macropixel approach proved to be more sensible than DHI evaluation. For enhancing efficacy of DHI we suggest a correction by weighting scores and considering relative standard deviations. This way the capability of DHI can be improved significantly. The very slight differences between the continuous methods (the homogeneity of which are much higher than that of conventional technologies) could be quantified. [ABSTRACT FROM AUTHOR]

We summarize our recent results on the oxidation of platinum surfaces, stressing the close connection between theory and experiment. The present theoretical approach is based on ab-initio quantum mechanics methods, such as density functional theory (DFT), ab-initio atomistic thermodynamics, Monte-Carlo methods and reactive molecular dynamics (RMD). Experimentally, photoelectron spectroscopy (XPS) under UHV and in-situ conditions (NAP-XPS) provides most of the discussed results. The oxidation of an extended variety of platinum surfaces is reviewed, starting from atomically flat Pt(111) over stepped surfaces to regularly shaped nanoparticles, under conditions ranging from UHV through ambient pressures up to electrochemical interfaces. [ABSTRACT FROM AUTHOR]

The integration of Process Analytical Technology (PAT) initiative into the continuous production of pharmaceuticals is indispensable for reliable production. The present paper reports the implementation of in-line Raman spectroscopy in a continuous blending and tableting process of a three-component model pharmaceutical system, containing caffeine as model active pharmaceutical ingredient (API), glucose as model excipient and magnesium stearate as lubricant. The real-time analysis of API content, blend homogeneity, and tablet content uniformity was performed using a Partial Least Squares (PLS) quantitative method. The in-line Raman spectroscopic monitoring showed that the continuous blender was capable of producing blends with high homogeneity, and technological malfunctions can be detected by the proposed PAT method. The Raman spectroscopy-based feedback control of the API feeder was also established, creating a ‘Process Analytically Controlled Technology’ (PACT), which guarantees the required API content in the produced blend. This is, to the best of the authors’ knowledge, the first ever application of Raman-spectroscopy in continuous blending and the first Raman-based feedback control in the formulation technology of solid pharmaceuticals. [ABSTRACT FROM AUTHOR]

In legume nodules, rhizobia differentiate into nitrogen-fixing forms called bacteroids, which are enclosed by a plant membrane in an organelle-like structure called the symbiosome. In the Inverted Repeat-Lacking Clade (IRLC) of legumes, this differentiation is terminal due to irreversible loss of cell division ability and is associated with genome amplification and different morphologies of the bacteroids that can be swollen, elongated, spherical, and elongated–branched, depending on the host plant. In Medicago truncatula, this process is orchestrated by nodule-specific cysteine-rich peptides (NCRs) delivered into developing bacteroids. Here, we identified the predicted NCR proteins in 10 legumes representing different subclades of the IRLC with distinct bacteroid morphotypes. Analysis of their expression and predicted sequences establishes correlations between the composition of the NCR family and the morphotypes of bacteroids. Although NCRs have a single origin, their evolution has followed different routes in individual lineages, and enrichment and diversification of cationic peptides has resulted in the ability to impose major morphological changes on the endosymbionts. The wide range of effects provoked by NCRs such as cell enlargement, membrane alterations and permeabilization, and biofilm and vesicle formation is dependent on the amino acid composition and charge of the peptides. These effects are strongly influenced by the rhizobial surface polysaccharides that affect NCR-induced differentiation and survival of rhizobia in nodule cells. [ABSTRACT FROM AUTHOR]

Raman mapping and chemometrics are proposed to accurately characterize the composition of tablets. The most critical step of the state-of-art curve resolution methods (such as multivariate curve resolution-alternating least squares [MCR-ALS]) is the determination of the number of constituents, when chemical imaging is coupled with multivariate data analysis. However, it is usually performed in a considerably subjective way. We propose a variable clustering approach for the identification of the main dimensionality of vibrational spectral data. The method was tested on a Raman map of a complex pharmaceutical tablet that contained 4 major components with high spectral resemblance, and a low-dose lubricant was also added for tableting purposes. Using a variable clustering algorithm called VARCLUS we were able to construct clusters from the Raman mapping data corresponding to the real constitution of the sample. The modeled clusters were analyzed by the 'sum of ranking differences' method. All 4 major components could be identified. The potential of the clustering algorithm was further assessed by applying MCR-ALS and spectral angle mapper-orthogonal projection methods. We have shown that variable clustering corresponded with MCR-ALS results and that it can be used to characterize the qualitative composition of an unknown pharmaceutical sample by combining the clustering algorithm with a pure component resolution method. Therefore, this method is well applicable to analyze and interpret the curve resolution of complex samples. Testing of the previously studied spectral angle mapper-orthogonal projection method, which relies on spectral reference libraries and even the low-dose lubricant (approximately 1% w/w), was identified through the chemical imaging. [ABSTRACT FROM AUTHOR]

We introduce a novel procedure that uses dynamic 3-D computer graphics as a diagnostic tool for assessing disease severity in schizophrenia patients, based on their reduced influence of top-down cognitive processes in interpreting bottom-up sensory input. Our procedure uses the hollow-mask illusion, in which the concave side of the mask is misperceived as convex, because familiarity with convex faces dominates sensory cues signaling a concave mask. It is known that schizophrenia patients resist this illusion and their resistance increases with illness severity. Our method uses virtual masks rendered with two competing textures: (a) realistic features that enhance the illusion; (b) random-dot visual noise that reduces the illusion. We control the relative weights of the two textures to obtain psychometric functions for controls and patients and assess illness severity. The primary novelty is the use of a rotating mask that is easy to implement on a wide variety of portable devices and avoids the use of elaborate stereoscopic devices that have been used in the past. Thus our method, which can also be used to assess the efficacy of treatments, provides clinicians the advantage to bring the test to the patient's own environment, instead of having to bring patients to the clinic. [ABSTRACT FROM AUTHOR]

This work demonstrates how nonlinearity in Raman spectrometry of pharmaceuticals can be handled and accurate quantification can be achieved by applying certain chemometric methods including variable selection. Such approach proved to be successful even if the component spectra are very similar or spectral intensities of the constituents are strongly different. The relevant examples are: blends of two crystalline forms of carvedilol (“CRYST-PM” blend) and a three-component pharmaceutical model system (“PHARM-TM” blend). The widely used classical least squares regression (CLS) and partial least squares regression (PLS) quantification methods provided relatively poor root mean squared error of prediction (RMSEP) values: approximately 2–4% and 4–10% for CRYST-PM and PHARM-TM respectively. The residual plots of these models indicated the nonlinearity of the preprocessed data sets. More accurate quantitative results could be achieved with properly applied variable selection methods. It was observed that variable selection methods discarded the most intensive bands while less intensive ones were retained as the most informative spectral ranges. As a result not only the accuracy of concentration determination was enhanced, but the linearity of models was improved as well. This indicated that nonlinearity occurred especially at the intensive spectral bands. Other methods developed for handling nonlinearity were also capable of adapting to the spectral nature of both data sets. The RMSEP could be decreased this way to 1% in CRYST-PM and 3–6% in PHARM-TM. Raman maps with accurate real concentrations could be prepared this way. All quantitative models were compared by the non-parametric sum of ranking differences (SRD) method, which also proved that models based on variable selection or nonlinear methods provide better quantification. [ABSTRACT FROM AUTHOR]

Investigation of downstream processing of nanofibrous amorphous solid dispersions to generate tablet formulation is in a quite early phase. Development of high speed electrospinning opened up the possibility to study tableting of electrospun solid dispersions (containing polyvinylpyrrolidone-vinyl acetate and itraconazole [ITR] in this case). This work was conducted to investigate the influence of excipients on dissolution properties and the feasibility of scaled-up rotary press tableting. The dissolution rates from tablets proved to be mainly composition dependent. Magnesium stearate acted as a nucleation promoting agent (providing an active hydrophobic environment for crystallization of ITR) hindering the total dissolution of ITR. This crystallization process proved to be temperature dependent as well. However, the extent of dissolution of more than 95% was realizable when a less hydrophobic lubricant, sodium stearyl fumarate (soluble in the medium), was applied. Magnesium stearate induced crystallization even if it was put in the dissolution medium next to proper tablets. After optimization of the composition, scaled-up tableting on a rotary press was carried out. Appropriate dissolution of ITR from tablets was maintained for 3 months at 25°C/60% relative humidity. HPLC measurements confirmed that ITR was chemically stable both in the course of downstream processing and storage. [ABSTRACT FROM AUTHOR]

Eukaryotic microalgae from the Chlorophyta division are used in various bio-industries due to their ability to produce high value compounds. Some of these compounds show plant biostimulant properties when applied to plants, soil or growth medium in hydroponic chambers. The first objective of this study was to evaluate if Chlamydomonas reinhardtii cc 124 and Chlorella sp. MACC-360 had biostimulant effect on Solanum lycopersicum L. The second objective was to investigate the importance of the application mode and time. The third goal was to reveal strain-specific actions of the two algae strains. Tomato plants were grown in pots layered with clay at the bottom and filled with the mixture of soil and vermiculate. In two sets of experiments the soil and plant leaves were treated with living algae and algal extract, respectively. In the first set, the culture suspension (CS) was centrifuged, the algae pellet was re-suspended in water (CCS), and this was applied weekly to soil, while algae extract (cell disrupted algae suspension – CDS) was sprayed on leaves bi-weekly. The flowering process, plant morphology, fruit features and pigment contents were analyzed. In the second set of experiments, the culture suspension per se (CS) was applied to the soil weekly and CDS was sprayed on leaves bi-weekly. Flowering kinetics, reproductive capacity and photosynthetic parameters were examined. Both algae strains increased pigment content, fruit weight and fruit diameter of tomato. Plants that received initial algae treatment at an advanced age performed better than those initially treated at a young age. Chlorella induced early flowering and fruit development while Chlamydomonas significantly delayed these milestone functions. Chlorella promoted conversion of light energy to chemical energy, while Chlamydomonas enhanced protection of photosynthetic parameters. Both strains increased leaf temperature differential as well as leaf thickness. Overall, both algae strains stimulated important agronomic-valuable functions in tomato. [Display omitted] • Unprocessed microalgae cultures have biostimulant effect on Solanum lycopersicum. • The effect is strain-specific and dependent on age of plants. • Chlorella sp. MACC-360 promotes early flowering and fruit development. • Ch. reinhardtii cc 124 enhances PSII protection. • Both strains increase leaf pigment and fruit weight. [ABSTRACT FROM AUTHOR]

[Display omitted] • Machine vision recently gained interest in the pharmaceutical industry. • Meloxicam was a model active pharmaceutical ingredient for particle size analysis. • Only an image of a tablet can be applied to extract critical quality attributes. • Image processing and analysis methods were developed for quality monitoring. • Quality-based classification was executed using pattern recognition neural network. The potential of machine vision systems has not currently been exploited for pharmaceutical applications, although expected to provide revolutionary solutions for in-process and final product testing. The presented paper aimed to analyze the particle size of meloxicam, a yellow model active pharmaceutical ingredient, in intact tablets by a digital UV/VIS imaging-based machine vision system. Two image processing algorithms were developed and coupled with pattern recognition neural networks for UV and VIS images for particle size-based classification of the prepared tablets. The developed method can identify tablets containing finer or larger particles than the target with more than 97% accuracy. Two algorithms were developed for UV and VIS images for particle size analysis of the prepared tablets. According to the applied statistical tests, the obtained particle size distributions were similar to the results of the laser diffraction-based reference method. Digital UV/VIS imaging combined with multivariate data analysis can provide a new non-destructive, rapid, in-line tool for particle size analysis in tablets. [ABSTRACT FROM AUTHOR]

Chemical imaging was used in this study as a powerful analytical tool to characterize pharmaceuticals in solid form. The majority of analyses are evaluated with bilinear modelling using only the pure component spectra or just the chemical images themselves to estimate the concentrations in each pixel, which are far from true quantitative determination. Our aim was to create more accurate concentration images using regression methods. For the first time in chemical imaging, variable selections with interval partial least squares (PLS) and with genetic algorithms (PLS-GA) were applied to increase the efficiency of the models. These were compared to numerous bilinear modelling and multivariate linear regression methods such as univariate regression, classical least squares (CLS), multivariate curve resolution-alternating least squares (MCR-ALS), principal component regression (PCR) and partial least squares (PLS). Two component spray-dried pharmaceuticals were used as a model. The paper is shown that, in contrast to the usual way of using either external validation or cross-validation, both should be performed simultaneously in order to get a clear picture of the prediction errors and to be able to select the appropriate models. Using PLS with variable selection, the root mean square errors were reduced to 3% per pixel by keeping only those peaks that are truly necessary for the estimation of concentrations. It is also shown that interval PLS can point out the best peak for univariate regression, and can thereby be of great help even when regulations allow only univariate models for product quality testing. Variable selection, besides yielding more accurate overall concentrations across a Raman map, also reduces the deviation among pixel concentrations within the images, thereby increasing the sensitivity of homogeneity studies. Copyright © 2015 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Long-standing evidence indicates that human immunodeficiency virus type 1 (HIV-1) preferentially integrates into a subset of transcriptionally active genes of the host cell genome. However, the reason why the virus selects only certain genes among all transcriptionally active regions in a target cell remains largely unknown. Here we show that HIV-1 integration occurs in the outer shell of the nucleus in close correspondence with the nuclear pore. This region contains a series of cellular genes, which are preferentially targeted by the virus, and characterized by the presence of active transcription chromatin marks before viral infection. In contrast, the virus strongly disfavours the heterochromatic regions in the nuclear lamin-associated domains and other transcriptionally active regions located centrally in the nucleus. Functional viral integrase and the presence of the cellular Nup153 and LEDGF/p75 integration cofactors are indispensable for the peripheral integration of the virus. Once integrated at the nuclear pore, the HIV-1 DNA makes contact with various nucleoporins; this association takes part in the transcriptional regulation of the viral genome. These results indicate that nuclear topography is an essential determinant of the HIV-1 life cycle. [ABSTRACT FROM AUTHOR]

This paper reports the application of surface enhanced Raman chemical imaging (SER-CI) as a potentially non-destructive quantitative analytical method for the investigation of model pharmaceutical formulations containing the active pharmaceutical ingredient (API) in low concentrations (0.5–2%). The application of chemometric techniques for processing the spectra enables the determination of API distribution in products of different concentrations. In addition, the applied multivariate curve resolution can be proper method to identify unexpected contaminants in illicit drugs. The drastic Raman signal enhancement in the presence of silver nanoparticles provides significantly improved calibration accuracy and, at the same time, radically decreased image acquisition time compared to conventional Raman chemical imaging. [ABSTRACT FROM AUTHOR]

Symbiosis between rhizobia soil bacteria and legume plants results in the formation of root nodules where plant cells are fully packed with nitrogen fixing bacteria. In the host cells, the bacteria adapt to the intracellular environment and gain the ability for nitrogen fixation. Depending on the host plants, the symbiotic fate of bacteria can be either reversible or irreversible. In Medicago and related legume species, the bacteria undergo a host-directed multistep differentiation process culminating in the formation of elongated and branched polyploid bacteria with definitive loss of cell division ability. The plant factors are nodule-specific symbiotic peptides. Approximately 600 of them are nodule-specific cysteine-rich (NCR) peptides produced in the rhizobium-infected plant cells. NCRs are targeted to the endosymbionts, and concerted action of different sets of peptides governs different stages of endosymbiont maturation, whereas the symbiotic function of individual NCRs is unknown. This study focused on NCR247, a cationic peptide exhibiting in vitro antimicrobial activities. We show that NCR247 acts in those nodule cells where bacterial cell division is arrested and cell elongation begins. NCR247 penetrates the bacteria and forms complexes with many bacterial proteins. Interaction with FtsZ required for septum formation is one of the host interventions for inhibiting bacterial cell division. Complex formation with the ribosomal proteins affects translation and contributes to altered proteome and physiology of the endosymbiont. Binding to the chaperone GroEL amplifies the NCR247-modulated biological processes. We show that GroEL1 of Sinorhizobium meliloti is required for efficient infection, terminal differentiation, and nitrogen fixation. [ABSTRACT FROM AUTHOR]

Multispecies bacterial communities such as the microbiota of the gastrointestinal tract can be remarkably stable and resilient even though they consist of cells and species that compete for resources and also produce a large number of antimicrobial agents. Computational modeling suggests that horizontal transfer of resistance genes may greatly contribute to the formation of stable and diverse communities capable of protecting themselves with a battery of antimicrobial agents while preserving a varied metabolic repertoire of the constituent species. In other words horizontal transfer of resistance genes makes a community compatible in terms of exoproducts and capable to maintain a varied and mature metagenome. The same property may allow microbiota to protect a host organism, or if used as a microbial therapy, to purge pathogens and restore a protective environment. [ABSTRACT FROM AUTHOR]

Motivation: Tandem mass spectrometry has become a standard tool for identifying post-translational modifications (PTMs) of proteins. Algorithmic searches for PTMs from tandem mass spectrum data (MS/MS) tend to be hampered by noisy data as well as by a combinatorial explosion of search space. This leads to high uncertainty and long search-execution times.Results: To address this issue, we present PTMTreeSearch, a new algorithm that uses a large database of known PTMs to identify PTMs from MS/MS data. For a given peptide sequence, PTMTreeSearch builds a computational tree wherein each path from the root to the leaves is labeled with the amino acids of a peptide sequence. Branches then represent PTMs. Various empirical tree pruning rules have been designed to decrease the search-execution time by eliminating biologically unlikely solutions. PTMTreeSearch first identifies a relatively small set of high confidence PTM types, and in a second stage, performs a more exhaustive search on this restricted set using relaxed search parameter settings. An analysis of experimental data shows that using the same criteria for false discovery, PTMTreeSearch annotates more peptides than the current state-of-the-art methods and PTM identification algorithms, and achieves this at roughly the same execution time. PTMTreeSearch is implemented as a plugable scoring function in the X!Tandem search engine.Availability: The source code of PTMTreeSearch and a demo server application can be found at http://net.icgeb.org/ptmtreesearch.Contacts: pongor@icgeb.orgSupplementary information: Supplementary materials are available at Bioinformatics online. [ABSTRACT FROM AUTHOR]

Motivation: Identification of proteins by mass spectrometry–based proteomics requires automated interpretation of peptide tandem mass spectrometry spectra. The effectiveness of peptide identification can be greatly improved by filtering out extraneous noise peaks before the subsequent database searching steps.Results: Here we present a novel chemical rule-based filtering algorithm, termed CRF, which makes use of the predictable patterns (rules) of collision-induced peptide fragmentation. The algorithm selects peak pairs that obey the common fragmentation rules within plausible limits of mass tolerance as well as peak intensity and produces spectra that can be subsequently submitted to any search engine. CRF increases the positive predictive value and decreases the number of random matches and thus improves performance by 15–20% in terms of peptide annotation using search engines, such as X!Tandem. Importantly, the algorithm also achieves data compression rates of ∼75%.Availability: The MATLAB source code and a web server are available at http://hydrax.icgeb.trieste.it/CRFilter/Contact: myers@icgeb.orgSupplementary information: Supplementary data are available at Bioinformatics online. [ABSTRACT FROM PUBLISHER]

Abstract: This paper reports the first application of surface enhanced Raman chemical imaging on pharmaceutical tablets containing the active ingredient (API) in very low concentrations. Taking advantage of the extremely intensive Raman signals in the presence of silver colloids, image aquisition time was radically decreased. Moreover, the investigation of drug distribution below the detection limit of regular micro-Raman spectrometry was made feasible. The characteristics of different manufacturing technologies could be revealed at very low API concentrations by using chemometric methods for processing and evaluating the large number of varying spectra provided with this imaging method. [Copyright &y& Elsevier]

Decomposition of lignocellulosic plant biomass by four filamentous fungi was carried out to facilitate subsequent anaerobic degradation and biogas formation. Agricultural side products, wheat straw and corn stover and forestry energy plant willow chips were selected as plant biomass sources. The substrates were confronted by pure cultures of Penicillium aurantiogriseum (new isolate from rumen), Trichoderma reesei (DSM768), Gilbertella persicaria (SZMC11086) and Rhizomucor miehei (SZMC11005). In addition to total cellulolytic filter paper degradation activity, the production of endoglucanase, cellobiohydrolase, β-glucosidase enzymes were followed during the pretreatment period, which lasted for 10 days at 37 °C. The products of pretreatments were subsequently tested for mesophilic biogas production in batch reactors. All 4 strains effectively pretreated the lignocellulosic substrates albeit in varying degrees, which was related to the level of the tested hydrolytic enzyme activities. Penicillium aurantiogriseum showed outstanding hydrolytic enzyme production and highest biogas yield from the partially degraded substrates. Corn stover was the best substrate for biomass decomposition and biogas production. Scanning electron microscopy confirmed the deep penetration of fungal hyphae into the lignocellulosic substrate in all cases. [Display omitted] • Lignocellulosic substrates were subjected to pretreatment by hydrolytic enzymes. • Wheat straw, corn stover and woody willow chips were the tested substrates. • Filamentous fungi produced the enzymes in situ during the10-day pretreatment at 37 °C. • Penicillium , Trichoderma , Gilbertella and Rhizomucor strains were assessed. • Substantially increased biogas production was obtained from the pretreated substrates. • Penicillium aurantiogriseum was the most efficient strain for pretreatment and biogas. [ABSTRACT FROM AUTHOR]

The epithelial tight junction (TJ) is the apical-most intercellular junction and serves as a gatekeeper for the paracellular pathway by permitting regulated passage of fluid and ions while restricting movement of large molecules. In addition to these vital barrier functions, TJ proteins are emerging as major signaling molecules that mediate crosstalk between the extracellular environment, the cell surface, and the nucleus. Biochemical studies have recently determined that epithelial TJs contain over a hundred proteins that encompass transmembrane proteins, scaffolding molecules, cytoskeletal components, regulatory elements, and signaling molecules. Indeed, many of these proteins have defined roles in regulating epithelial polarity, differentiation, and proliferation. This review will focus on recent findings that highlight a role for TJ proteins in controlling cell proliferation during epithelial homeostasis, wound healing, and carcinogenesis. [ABSTRACT FROM AUTHOR]

First principles-based kinetic Monte Carlo (kMC) simulations are performed for the CO oxidation on RuO2(110) under steady-state reaction conditions. The simulations include a set of elementary reaction steps with activation energies taken from three different ab initio density functional theory studies. Critical comparison of the simulation results reveals that already small variations in the activation energies lead to distinctly different reaction scenarios on the surface, even to the point where the dominating elementary reaction step is substituted by another one. For a critical assessment of the chosen energy parameters, it is not sufficient to compare kMC simulations only to experimental turnover frequency (TOF) as a function of the reactant feed ratio. More appropriate benchmarks for kMC simulations are the actual distribution of reactants on the catalyst's surface during steady-state reaction, as determined by in situ infrared spectroscopy and in situ scanning tunneling microscopy, and the temperature dependence of TOF in the from of Arrhenius plots. © 2012 Wiley Periodicals, Inc. [ABSTRACT FROM AUTHOR]

Abstract: Chemical imaging is a rapidly emerging analytical method in pharmaceutical technology. Due to the numerous chemometric solutions available, characterization of pharmaceutical samples with unknown components present has also become possible. This study compares the performance of current state-of-the-art curve resolution methods (multivariate curve resolution-alternating least squares, positive matrix factorization, simplex identification via split augmented Lagrangian and self-modelling mixture analysis) in the estimation of pure component spectra from Raman maps of differently manufactured pharmaceutical tablets. The batches of different technologies differ in the homogeneity level of the active ingredient, thus, the curve resolution methods are tested under different conditions. An empirical approach is shown to determine the number of components present in a sample. The chemometric algorithms are compared regarding the number of detected components, the quality of the resolved spectra and the accuracy of scores (spectral concentrations) compared to those calculated with classical least squares, using the true pure component (reference) spectra. It is demonstrated that using appropriate multivariate methods, Raman chemical imaging can be a useful tool in the non-invasive characterization of unknown (e.g. illegal or counterfeit) pharmaceutical products. [Copyright &y& Elsevier]

The dose responses of the most commonly used high potency sweeteners (HPSs) have been measured by a more precise sensory procedure. The data were analyzed by Black's pharmacological model that takes into account not only agonist binding affinity but transduction efficiency as well. HPSs are clearly segregated into 2 groups depending on whether they bind to T1R2 or T1R3 of the receptor heterodimer. Surprisingly, the more potent sweeteners have lower transduction efficiencies. The implications of these on consumer product development and HPS design are discussed. [ABSTRACT FROM AUTHOR]

Motivation: A major goal of biomedical research in personalized medicine is to find relationships between mutations and their corresponding disease phenotypes. However, most of the disease-related mutational data are currently buried in the biomedical literature in textual form and lack the necessary structure to allow easy retrieval and visualization. We introduce a high-throughput computational method for the identification of relevant disease mutations in PubMed abstracts applied to prostate (PCa) and breast cancer (BCa) mutations.Results: We developed the extractor of mutations (EMU) tool to identify mutations and their associated genes. We benchmarked EMU against MutationFinder—a tool to extract point mutations from text. Our results show that both methods achieve comparable performance on two manually curated datasets. We also benchmarked EMU's performance for extracting the complete mutational information and phenotype. Remarkably, we show that one of the steps in our approach, a filter based on sequence analysis, increases the precision for that task from 0.34 to 0.59 (PCa) and from 0.39 to 0.61 (BCa). We also show that this high-throughput approach can be extended to other diseases.Discussion: Our method improves the current status of disease-mutation databases by significantly increasing the number of annotated mutations. We found 51 and 128 mutations manually verified to be related to PCa and Bca, respectively, that are not currently annotated for these cancer types in the OMIM or Swiss-Prot databases. EMU's retrieval performance represents a 2-fold improvement in the number of annotated mutations for PCa and BCa. We further show that our method can benefit from full-text analysis once there is an increase in Open Access availability of full-text articles.Availability: Freely available at: http://bioinf.umbc.edu/EMU/ftp.Contact: mkann@umbc.eduSupplementary information: Supplementary data are available at Bioinformatics online. [ABSTRACT FROM AUTHOR]

Background and Purpose: Torsades de pointes (TdP) liability is a stochastic event, which indicates that unidentified factors have an important role in facilitating the initiation of TdP by increasing the probability of TdP occurrence. We sought to identify factors that facilitate drug-induced TdP.Experimental Approach: We studied dofetilide-induced TdP in pentobarbital-anaesthetized, phenylephrine-sensitized rabbits, seeking biomarkers that discriminated between the animals that experienced TdP ('TdP+' animals) and those that did not ('TdP-' animals). As novel variables, the beat-to-beat variability and instability of ECG intervals were measured at preset times, irrespective of whether or not hearts were in stable sinus rhythm ('absolute' variability and instability). Autonomic activity was also determined.Key Results: Dofetilide delayed repolarization and induced arrhythmias prior to TdP. The variability of the coupling interval and shape of arrhythmic beats before TdP were significantly greater in the 'TdP+' group than in the 'TdP-' group. Accordingly, the 'absolute' variability and instability of the ECG intervals were significantly elevated in the 'TdP+' group. Phenylephrine increased significantly the up-baroreflex sensitivity in the 'TdP+' group before dofetilide administration.Conclusions and Implications: 'Preceding' arrhythmias have characteristics that permit prediction of TdP occurrence: the more chaotic the ventricular rhythm, the greater the probability of TdP initiation. This suggests that complexity of the arrhythmic beats may play an important mechanistic role in TdP genesis. The electrical instability quantified by the novel 'absolute' variability and instability parameters correlates with the probability of TdP occurrence. Baroreflex may contribute to TdP genesis in vivo. [ABSTRACT FROM AUTHOR]

Three functional NiFe hydrogenases were previously characterized in Thiocapsa roseopersicina BBS: two of them are attached to the periplasmic membrane (HynSL and HupSL), and one is localized in the cytoplasm (HoxEFUYH). The ongoing genome sequencing project revealed the presence of genes coding for another soluble Hox-type hydrogenase enzyme (hox2FUYH). Hox2 is a heterotetrameric enzyme; no indication for an additional subunit was found. Detailed comparative in vivo and in vitro activity and expression analyses of HoxEFUYH (Hoxi) and the newly discovered Hox2 enzyme were performed. Functional differences between the two soluble NiFe hydrogenases were disclosed. Hoxi seems to be connected to both sulfur metabolism and dark/photofermentative processes. The bidirectional Hox2 hydrogenase was shown to be metabolically active under specific conditions: it can evolve hydrogen in the presence of glucose at low sodium thiosulfate concentration. However, under nitrogen-fixing conditions, it can oxidize H2 but less than the other hydrogenases in the cell. [ABSTRACT FROM AUTHOR]

Proarrhythmia, the development of new or worse arrhythmias in response to drug therapy, is a major limitation to the development and use of new drugs. There are different types of drug-induced proarrhythmia, including long-QT syndrome (LQTS), short-QT syndrome and proarrhythmia related to Na+-channel blockade/conduction impairment. By far the most important form of proarrhythmia at present is drug-induced LQTS and its associated characteristic tachyarrhythmia, torsades de pointes (TdP). TdP arises when cellular action potentials (APs) are excessively prolonged, leading to arrhythmogenic afterdepolarizations, especially early afterdepolarizations (EADs), which trigger complex re-entry in a substrate involving increased transmural dispersion of repolarization. In vitro screening, increasingly involving high-throughput assays, is used to assess potential candidate molecules and eliminate potentially problematic structures at an early stage of development. The most commonly used screening assays assess drug block of the K+ current carried by human ether-à-go-go (hERG) subunits, corresponding to the rapid delayed-rectifier K+ channel, the overwhelmingly most common target of TdP-inducing drugs. In addition, the effects of drugs on AP duration or the in vivo equivalent, QT interval, are often assessed in animal models. Methods available for repolarization-related proarrhythmic risk assessment include in vitro (Langendorff-perfused rabbit or guinea pig hearts) and in vivo models (such as a-adrenoceptor-stimulated rabbits, rabbits with reduced repolarization reserve due to block of slow delayed-rectifier current, animals with chronic atrioventricular block or animals with cardiac remodelling caused by congestive heart failure). In silico modelling may be helpful for molecular design of non-hERG blocking candidates and for optimization of compound selection (at the molecular and pharmacological profile levels). Finally, clinical evaluation of effects on electrocardiographic intervals (particularly QT) and cardiac rhythm are often needed, both prior to drug approval and after successful introduction on the market (postmarketing surveillance). The successful avoidance of proarrhythmic complications is a shared responsibility of the innovative pharmaceutical industry, regulatory authorities, partners in the clinical drug development phase and practicing physicians. This paper reviews the principal forms of proarrhythmia and the methods that can be used to minimize the risk of proarrhythmia in drug development and clinical practice, with particular emphasis on the most common and problematic form, acquired LQTS. [ABSTRACT FROM AUTHOR]

Background and Purpose: The Na+/Ca2+ exchanger (NCX) may contribute to triggered activity and transmural dispersion of repolarization, which are substrates of torsades de pointes (TdP) type arrhythmias. This study examined the effects of selective inhibition of the NCX by SEA0400 on the occurrence of dofetilide-induced TdP.Experimental Approach: Effects of SEA0400 (1 micromol x L(-1)) on dofetilide-induced TdP was studied in isolated, Langendorff-perfused, atrioventricular (AV)-blocked rabbit hearts. To verify the relevance of the model, lidocaine (30 micromol x L(-1)) and verapamil (750 nmol x L(-1)) were also tested against dofetilide-induced TdP.Key Results: Acute AV block caused a chaotic idioventricular rhythm and strikingly increased beat-to-beat variability of the RR and QT intervals. SEA0400 exaggerated the dofetilide-induced increase in the heart rate-corrected QT interval (QTc) and did not reduce the incidence of dofetilide-induced TdP [100% in the SEA0400 + dofetilide group vs. 75% in the dofetilide (100 nmol x L(-1)) control]. In the second set of experiments, verapamil further increased the dofetilide-induced QTc prolongation and neither verapamil nor lidocaine reduced the dofetilide-induced increase in the beat-to-beat variability of the QT interval. However, lidocaine decreased and verapamil prevented the development of dofetilide-induced TdP as compared with the dofetilide control (TdP incidence: 13%, 0% and 88% respectively).Conclusions and Implications: Na+/Ca2+ exchanger does not contribute to dofetilide-induced TdP, whereas Na+ and Ca2+ channel activity is involved in TdP genesis in isolated, AV-blocked rabbit hearts. Neither QTc prolongation nor an increase in the beat-to-beat variability of the QT interval is a sufficient prerequisite of TdP genesis in rabbit hearts. [ABSTRACT FROM AUTHOR]

Abstract: Development and testing of protein classification algorithms are hampered by the fact that the protein universe is characterized by groups vastly different in the number of members, in average protein size, similarity within group, etc. Datasets based on traditional cross-validation (k-fold, leave-one-out, etc.) may not give reliable estimates on how an algorithm will generalize to novel, distantly related subtypes of the known protein classes. Supervised cross-validation, i.e., selection of test and train sets according to the known subtypes within a database has been successfully used earlier in conjunction with the SCOP database. Our goal was to extend this principle to other databases and to design standardized benchmark datasets for protein classification. Hierarchical classification trees of protein categories provide a simple and general framework for designing supervised cross-validation strategies for protein classification. Benchmark datasets can be designed at various levels of the concept hierarchy using a simple graph-theoretic distance. A combination of supervised and random sampling was selected to construct reduced size model datasets, suitable for algorithm comparison. Over 3000 new classification tasks were added to our recently established protein classification benchmark collection that currently includes protein sequence (including protein domains and entire proteins), protein structure and reading frame DNA sequence data. We carried out an extensive evaluation based on various machine-learning algorithms such as nearest neighbor, support vector machines, artificial neural networks, random forests and logistic regression, used in conjunction with comparison algorithms, BLAST, Smith-Waterman, Needleman-Wunsch, as well as 3D comparison methods DALI and PRIDE. The resulting datasets provide lower, and in our opinion more realistic estimates of the classifier performance than do random cross-validation schemes. A combination of supervised and random sampling was used to construct model datasets, suitable for algorithm comparison. The datasets are available at http://hydra.icgeb.trieste.it/benchmark. [Copyright &y& Elsevier]

Abstract: Identification of problematic protein classes (domain types, protein families) that are difficult to predict from sequence is a key issue in genome annotation. ROC (Receiver Operating Characteristic) analysis is routinely used for the evaluation of protein similarities, however its results – the area under curve (AUC) values – are differentially biased for the various protein classes that are highly different in size. We show the bias can be compensated for by adjusting the length of the top list in a class-dependent fashion, so that the number of negatives within the top list will be equal to (or proportional with) the size of the positive class. Using this balanced protocol the problematic classes can be identified by their AUC values, or by a scatter diagram in which the AUC values are plotted against positive/negative ratio of the top list. The use of likelihood-ratio scoring (Kaján et al, Bioinformatics, 22, 2865–2869, 2007) the bias caused by class imbalance can be further decreased. [Copyright &y& Elsevier]

Abstract: The present study was designed to investigate the effect of nicotine and polyaromatic hydrocarbon compounds on cerebral endothelial cells (CECs). Nicotine treatments from 15min to 5h did not cause any changes in the expression and localization of principal junctional proteins. One day of treatment with a relatively high concentration of nicotine induced a decrease in the expression of the tight junction protein ZO-1, occludin, and the adherens junction protein, cadherin. Treatment with 3×10−5 M phenanthrene for 24h caused a redistribution of occludin from the Triton X-100 insoluble to the Triton X-100 soluble fraction. Transendothelial electrical resistance was not significantly affected by 24h treatments with nicotine, methylanthracene or phenanthrene. However, 24h nicotine treatment increased transendothelial permeability in CECs exposed to oxidative stress. Both nicotine and phenanthrene were able to regulate the expression of a large number of proteins as revealed by 2D electrophoresis. Our experiments suggest that tobacco smoking may affect the junctional complex of CECs, and that this effect is enhanced by oxidative stress. [Copyright &y& Elsevier]

Abstract: In anaesthetized rabbits, α1-adrenoceptor stimulation increases the propensity of repolarization-prolonging drugs to induce torsade de pointes ventricular tachycardia. However, it is not known whether the stimulation of intracardiac α1-adrenoceptors, or the increased ventricular stretch caused by extracardiac α1-adrenoceptor-mediated peripheral vasoconstriction and increased resistance, are the sensitizing factors. Accordingly, this study investigated whether a sustained load-induced left ventricular stretch or stimulation of the intracardiac α1-adrenoceptors with 100 nM methoxamine, or the co-application of these two, can assist dofetilide (100 nM) to elicit torsade de pointes in isolated Langendorff-perfused, rabbit hearts. In the stretched hearts, a constant high level of stretch was produced by a water-filled left ventricular balloon inflated to a volume of 1.4 ml, whereby the systolic and end-diastolic pressures virtually did not exceed the physiological range (≤157±11 mm Hg and ≤9±2 mm Hg, respectively; mean±S.E.M.). Perfusion with dofetilide prolonged the QT interval significantly and indifferently in all hearts. Neither this stretch nor methoxamine nor the in combination affected the QT interval, the heart rate or the coronary flow. Interestingly, neither the stretch (‘dofetilide+stretch’ group, n =8 hearts), nor methoxamine (‘dofetilide+methoxamine’ group, n =8 hearts), nor the in combination (‘dofetilide+stretch+methoxamine’ group, n =8 hearts) elevated the incidence of torsade de pointes as compared with the ‘dofetilide alone’ group (n =9 hearts) (0%, 25%, 0%, versus 44%, respectively). In conclusion, neither a sustained load-induced stretch nor α1-adrenoceptor stimulation nor the in combination assisted dofetilide to induce torsade de pointes in isolated rabbit hearts, suggesting the importance of extracardiac α1-adrenoceptor stimulation in this phenomenon. [Copyright &y& Elsevier]

The abundance of mRNAs transcribed from human genes of the calpain superfamily was studied in 72 human tissues and cell types by the Human Multiple Tissue Expression (MTE™) Array technique. The analysis included the large subunits of µ- and m-calpains, the small subunits, calpastatin and calpain 3 (p94). Besides specific data on transcriptional activity, two major conclusions emerged: (i) 'ubiquitous' calpains are not expressed in all cell types, and (ii) a 'tissue-specific' calpain may be expressed in many cell types apart from the one in which it is particularly abundant. Therefore, the categoric classification of 'ubiquitous' vs. 'tissue-specific' calpains is a simplification. [ABSTRACT FROM AUTHOR]

The calpains are Ca2+-activated cysteine proteases whose biochemical properties have been extensively characterized in vitro. Less is known, however, about the physiological role of calpains. In this respect, Drosophila melanogaster is a useful experimental organism to study calpain activity and regulation in vivo. The sequencing of the fly genome has been recently completed and a novel calpain homologue has been identified in the CG3692 gene product. We embarked on the cloning and characterization of this putative novel calpain. We demonstrate that the actual calpain is different from the predicted protein and we provide experimental evidence for the correction of the genomic annotation. This novel protein, Calpain C, must be catalytically inactive, having mutated active site residues but is otherwise structurally similar to the other known fly calpains. Moreover, we analysed Calpain C RNA expression during Drosophila development by RT-PCR and RNA in situ hybridization, which revealed strong expression in the salivary glands. [Copyright &y& Elsevier]

In the present research, thermal investigation of amorphous solid dispersions (ASDs) was performed in order to compare their relaxation transitions. Two different active pharmaceutical ingredients (APIs), namely naproxen (NAP) and spironolactone (SPIR), were used as model drugs and combined with polyvinylpyrrolidone vinyl acetate (PVPVA64) copolymer to form stable ASDs. The reason for the API selection was their different interacting potentials based on the presence (in the case of NAP) and the lack of H-bond donor group (in the case of SPIR). Determination of both Tg and sub-Tg transitions suggested that ASDs containing NAP and PVPVA64 are ‘interacting’ systems with respect to the H-bonding. Besides, temperature-dependent Raman spectroscopic experiments confirmed that the naphthalene ring of the NAP has a significant role in the sub-Tg relaxations. In contrast, SPIR-PVPVA64 systems proved to be ‘non-interacting’ ASDs according to the MDSC, TSDC, and Raman measurements. This study highlights that the combination of the results of different thermoanalytical investigations with spectroscopic methods helps to understand the molecular background of the relaxations in ASDs and thus contributes to the conscious design of stable amorphous pharmaceuticals in the early stage of development. [ABSTRACT FROM AUTHOR]

• Fungal biodeteriogens of a cultural heritage church are isolated and identified. • P. chartarum and B. pseudobassiana are described first as fungal biodeteriogens. • Antifungal proteins (NFAP and NFAP2) inhibit the growth of biodeterioration fungi. • Application of NFAP and NFAP2 on wall model reduces the fungus-infected area. • The protective effect of NFAP and NFAP2 is maintained in long-term. Fungi are able to permanently damage cultural heritage buildings and stone monuments. Protection against these biodeteriogen fungi is challenging because it may require the use of drastic techniques to remove fungal colonies and chemicals, which can cause further damage, especially on mural paintings. Natural biocides are less damaging, greener, and safer and mainly include essential oils and plant-derived substances. Studies on the applicability of purified antifungal proteins in the conservation of cultural heritage buildings are lacking. In this study, we isolated mold mycoflora from the biodeteriorated inner walls of the Calvinist church of Kézdialbis (Kézdialbis, Romania) and investigated the in vitro antifungal efficacy of Neosartorya (Aspergillus) fischeri antifungal proteins, NFAP and NFAP2 against them. Antifungal susceptibility testing revealed that these proteins inhibited the growth of the most commonly isolated indoor biodeteriogen fungi from the site (Aspergillus creber, Aureobasidium pullulans, Cladosporium sp. , Penicillium chrysogenum, and Parengyodontium album) and not common ones (Mucor hiemalis, Sarocladium kiliense) with different spectra and efficacies. A phytopathogen and an entomopathogen species (Pseudopithomyces chartarum and Beauveria pseudobassiana , respectively) were also isolated and described first as fungal biodeteriogens of the inner walls. Among them, P. chartarum was susceptible to NFAP2. Next, we tested the applicability of NFAP and NFAP2 in protecting cultural heritage buildings in a wall model experiment against A. creber. Topical application of both antifungal proteins significantly decreased the area infected by fungi. Scanning electron microscopy of the wall models showed that A. creber had reduced growth and conidiation in the presence of NFAP and NFAP2. This inhibitory activity was maintained for a long time. Strong UV irradiation decreased the protective effect of both proteins in the wall model. Taking into account these results, the high stability of NFAP and NFAP2 in harsh environments, and their bulk recombinant producibility, we suggest that both can be used in the protection and posttreatment of painted walls of cultural heritage buildings to clean up mural painting or to inhibit mold recolonization after mechanical, physical, or chemical decontamination. [Display omitted] [ABSTRACT FROM AUTHOR]

Spreading depolarization (SD) is a wave of mass depolarization that causes profound perfusion changes in acute cerebrovascular diseases. Although the astrocyte response is secondary to the neuronal depolarization with SD, it remains to be explored how glial activity is altered after the passage of SD. Here, we describe post-SD high frequency astrocyte Ca2+ oscillations in the mouse somatosensory cortex. The intracellular Ca2+ changes of SR101 labeled astrocytes and the SD-related arteriole diameter variations were simultaneously visualized by multiphoton microscopy in anesthetized mice. Post-SD astrocyte Ca2+ oscillations were identified as Ca2+ events non-synchronized among astrocytes in the field of view. Ca2+ oscillations occurred minutes after the Ca2+ wave of SD. Furthermore, fewer astrocytes were involved in Ca2+ oscillations at a given time, compared to Ca2+ waves, engaging all astrocytes in the field of view simultaneously. Finally, our data confirm that astrocyte Ca2+ waves coincide with arteriolar constriction, while post-SD Ca2+ oscillations occur with the peak of the SD-related vasodilation. This is the first in vivo study to present the post-SD astrocyte Ca2+ oscillations. Our results provide novel insight into the spatio-temporal correlation between glial reactivity and cerebral arteriole diameter changes behind the SD wavefront. [ABSTRACT FROM AUTHOR]

In recent years, core-shell nanofibrous drug delivery systems have received increasing attention due to their ability to incorporate two or more active pharmaceutical ingredients (APIs) individually into the desired layer (either core or sheath) and thereby finely tune the release profiles of even incompatible drugs in one system. This study aims to perform formulation and solid-state characterisation of levofloxacin-loaded polylactic acid (PLA) - naproxen-sodium-loaded polyvinyl pyrrolidone (PVP) bicomponent core-shell fibrous sheets and examine the electro spinnability of the precursor combinations. The selected drugs have potential therapeutic relevance in similar systems intended for wound healing; however, in this study, they are used as model drugs to understand the physicochemical properties of a drug loaded system. In order to determine the best core- and shell-solution combination, a full factorial experimental design is used. A combination of various morphological (scanning electron microscopy and transmission electron microscopy) and microstructural characterisation techniques (X-ray photoelectron spectroscopy and Raman spectroscopy) was applied to non-invasively obtain information about the structure of the fibres and the embedded drugs. The results indicate that core-shell fibres of different compositions could be successfully prepared with various structural homogeneities. The best core-shell structure was obtained using a combination of 15% (w/w) shell concentration and 8% (w/w) PLA solution concentration. In addition to the conventional core-shell structural verification methods, the Raman spectroscopy method was implemented to reveal not only the core-shell structure of the PLA/PVP nanofibers but also the form of the embedded drugs. The Raman mapping of the fibres confirm the above results, and it is shown that an amorphous solid dispersion is formed as a result of the coaxial electrospinning process. [ABSTRACT FROM AUTHOR]

Spreading depolarizations (SDs) indicate injury progression and predict worse clinical outcome in acute brain injury. We demonstrate in rodents that acute brain swelling upon cerebral ischemia impairs astroglial glutamate clearance and increases the tissue area invaded by SD. The cytotoxic extracellular glutamate accumulation (>15 µM) predisposes an extensive bulk of tissue (4–5 mm2) for a yet undescribed simultaneous depolarization (SiD). We confirm in rat brain slices exposed to osmotic stress that SiD is the pathological expansion of prior punctual SD foci (0.5–1 mm2), is associated with astrocyte swelling, and triggers oncotic neuron death. The blockade of astrocytic aquaporin-4 channels and Na+/K+/Cl− co-transporters, or volume-regulated anion channels mitigated slice edema, extracellular glutamate accumulation (<10 µM) and SiD occurrence. Reversal of slice swelling by hyperosmotic mannitol counteracted glutamate accumulation and prevented SiD. In contrast, inhibition of glial metabolism or inhibition of astrocyte glutamate transporters reproduced the SiD phenotype. Finally, we show in the rodent water intoxication model of cytotoxic edema that astrocyte swelling and altered astrocyte calcium waves are central in the evolution of SiD. We discuss our results in the light of evidence for SiD in the human cortex. Our results emphasize the need of preventive osmotherapy in acute brain injury. [ABSTRACT FROM AUTHOR]

Today, graphene oxide (GO) has gained well-deserved recognition, with its applications continuing to increase. Much of the processing of GO-based devices occurs in a dispersed form, which explains the commercialization of GO suspensions. Aging of these suspensions can, however, affect the shelf life and thus their application potential. Aging of GO preparations is often acknowledged, but no longer-term systematic study has been reported on the alteration of GO suspensions. This paper investigates high-concentration (10 mg/mL) aqueous GO suspensions over a 2-year time scale. In addition to steady shear tests, the dynamic behavior of the suspensions was studied in more detail by transient shear and frequency sweep measurements. Both the viscosity and the dynamic moduli increased with age, particularly within the first year. The results of the complementary Raman spectroscopic studies indicate that the change in the rheological behavior with aging results from a slow oxidation process occurring in the highly acidic aqueous medium during the relatively long-term storage. The (over)oxidized layers peel off spontaneously or are removed by high shear stress, resulting in increased viscosity, as it was corroborated by XRD and XPS. [ABSTRACT FROM AUTHOR]

The aim of this work was to develop a PAT platform consisting of four complementary instruments for the characterization of electrospun amorphous solid dispersions with meloxicam. The investigated methods, namely NIR spectroscopy, Raman spectroscopy, Colorimetry and Image analysis were tested and compared considering the ability to quantify the active pharmaceutical ingredient and to detect production errors reflected in inhomogeneous deposition of fibers. Based on individual performance the calculated RMSEP values ranged between 0.654% and 2.292%. Mid-level data fusion consisting of data compression through latent variables and application of ANN for regression purposes proved efficient, yielding an RMSEP value of 0.153%. Under these conditions the model could be validated accordingly on the full calibration range. The complementarity of the PAT tools, demonstrated from the perspective of captured variability and outlier detection ability, contributed to model performance enhancement through data fusion. To the best of the author's knowledge, this is the first application of data fusion in the field of PAT for efficient handling of big-analytical-data provided by high-throughput instruments. [ABSTRACT FROM AUTHOR]

The pharmaceutical industry has never seen such a vast development in process analytical methods as in the last decade. The application of near-infrared (NIR) and Raman spectroscopy in monitoring production lines has also become widespread. This work aims to utilize the large amount of information collected by these methods by building an artificial neural network (ANN) model that can predict the dissolution profile of the scanned tablets. An extended release formulation containing drotaverine (DR) as a model drug was developed and tablets were produced with 37 different settings, with the variables being the DR content, the hydroxypropyl methylcellulose (HPMC) content and compression force. NIR and Raman spectra of the tablets were recorded in both the transmission and reflection method. The spectra were used to build a partial least squares prediction model for the DR and HPMC content. The ANN model used these predicted values, along with the measured compression force, as input data. It was found that models based on both NIR and Raman spectra were capable of predicting the dissolution profile of the test tablets within the acceptance limit of the f2 difference factor. The performance of these ANN models was compared to PLS models using the same data as input, and the prediction of the ANN models was found to be more accurate. The proposed method accomplishes the prediction of the dissolution profile of extended release tablets using either NIR or Raman spectra. [ABSTRACT FROM AUTHOR]

Major histocompatibility complex (MHC) genes are commonly used markers for monitoring adaptive genetic and evolutionary potential of species. In this study, we investigated genetic variation of the MHC class II DRB locus in the chamois genus Rupicapra by using next-generation sequencing. Sequencing of 102 samples led to the identification of 25 alleles, 11 of which are novel. The high ratio of the relative rates of nonsynonymous to synonymous mutations (dN/dS) suggests a signal of positive selection on this locus. We analyzed patterns of genetic variation within and among 2 subspecies of Northern Chamois and compared them to previously published studies using neutral markers to provide a basis for assessing the effects of demographic processes. Our analyses have shown that alleles are likely to be maintained by balancing selection in different populations with similar frequencies and that this mechanism also works in small, isolated populations that are strongly affected by genetic drift. [ABSTRACT FROM AUTHOR]

[Carbonatotetraamminecobalt(III)] permanganate monohydrate was synthesized first in the metathesis reaction of [Co(NH3)4CO3]NO3 and NaMnO4 in aqueous solution. Its thermal dehydration at 100 °C resulted in phase-pure [Co(NH3)4CO3]MnO4 (compound 1). Compounds 1 and 2 (i.e., the hydrated form) were studied with IR, far-IR, and low-temperature Raman spectroscopies, and their vibrational modes were assigned. The lattice parameters were determined by powder X-ray diffraction (PXRD) and single crystal X-ray diffraction (SXRD) methods for the triclinic and orthorhombic compounds 1 and 2, respectively. The detailed structure of compound 2 was determined, and the role of hydrogen bonds in the structural motifs was clarified. UV studies on compounds 1 and 2 showed the distortion of the octahedral geometry of the complex cation during dehydration because of the partial loss of the hydrogen bonds between the crystal water and the ligands of the complex cation. The thermal decomposition consists of a solid phase quasi-intramolecular redox reaction between the ammonia ligands and permanganate anions with the formation of ammonia oxidation products (H2O, NO, N2O, and CO2). The solid phase reaction product is amorphous cobalt manganese oxide containing ammonium, carbonate (and nitrate) anions. The temperature-controlled thermal decomposition of compound 2 in toluene at 110 °C showed that one of the decomposition intermediates is ammonium nitrate. The decomposition intermediates are transformed into Co1.5Mn1.5O4 spinel with MnCo2O4 structure upon further heating. Solid compound 2 gave the spinel at 500 °C both in an inert and air atmosphere, whereas the sample pre-treated in toluene at 110 °C without and with the removal of ammonium nitrate by aqueous washing, gave the spinel already at 300 and 400 °C, respectively. The molten NH4NO3 is a medium to start spinel crystallization, but its decomposition stops further crystal growth of the spinel phase. By this procedure, the particle size of the spinel product as low as ~4.0 nm could be achieved for the treatments at 300 and 400 °C, and it increased only to 5.7 nm at 500 °C. The nano-sized mixed cobalt manganese oxides are potential candidates as Fischer-Tropsch catalysts. [ABSTRACT FROM AUTHOR]