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7 figures, 2 tables., Multidrug-resistant bacteria such as methicillin-resistant Staphylococcus aureus (MRSA) is one of the major causes of hospital-acquired and community infections and pose a challenge to the human health care system. Therefore, it is important to find new drugs that show activity against these bacteria, both in monotherapy and in combination with other antimicrobial drugs. Gliotoxin (GT) is a mycotoxin produced by Aspergillus fumigatus and other fungi of the Aspergillus genus. Some evidence suggests that GT shows antimicrobial activity against S. aureus in vitro, albeit its efficacy against multidrug-resistant strains such as MRSA or vancomycin-intermediate S. aureus (VISA) strainsis not known. This work aimed to evaluate the antibiotic efficacy of GT as monotherapy or in combination with other therapeutics against MRSA in vitro and in vivo using a Caenorhabditis elegans infection model., This research was funded by FEDER (Fondo Europeo de Desarrollo Regional, Gobierno de Aragón (Group B29_17R), Ministerio de Ciencia, Innovación e Universidades (MCNU), Agencia Estatal de Investigación (SAF2017-83120-C2-1-R), ASPANOA, GILEAD (GLD18/00100), Donación Javier Saura Carceller, and Carrera de la Mujer de Monzón. J.P. was supported by Fundacion Aragon I+D (ARAID). P.E. was supported by Fondo Garantıa Empleo Juvenil/INAEM. L.C. and S.R. were granted funding by a DGA predoctoral contract. M.A. was granted funding by a Juan de la Cierva contract of Spanish Ministry of Economy and Competitiveness (FJCI-2017-31629).

Objective Granzyme A (GzmA) levels are elevated in the plasma and synovium of patients with rheumatoid arthritis (RA), suggesting involvement of this protease in the pathogenesis of the disease. GzmA contributes to sepsis by regulating the production of proinflammatory cytokines. The purpose of this study was to evaluate the contribution of GzmA to the pathogenesis of RA in vivo and to examine the possibility that GzmA acting via tumor necrosis factor (TNF) stimulates osteoclastogenesis. Methods Inflammatory arthritis induced by type II collagen was evaluated in wild-type, GzmA-deficient, and perforin-deficient mice. The osteoclastogenic potential of GzmA was examined in vitro using bone marrow cells and colony-forming unit–granulocyte–macrophage (CFU-GM) cells and in vivo using GzmA-deficient mice. Results Gene deletion of GzmA attenuated collagen-induced arthritis, including serum levels of proinflammatory cytokines, joint damage, and bone erosion in affected mice, suggesting that osteoclast activity is reduced in the absence of GzmA. Accordingly, GzmA-treated bone marrow cells produced multinucleated cells that fulfilled the criteria for mature osteoclasts: tartrate-resistant acid phosphatase (TRAP) activity, β integrin expression, calcitonin receptor expression, and resorptive activity on dentin slices. GzmA appeared to act without accessory cells, and its activity was not affected by osteoprotegerin, suggesting a minor contribution of RANKL. It also induced the expression and secretion of TNF. Neutralization of TNF or stimulation of CFU-GM cells from TNF–/– mice prevented GzmA-induced osteoclastogenesis. GzmA-deficient mice had reduced osteoclastogenesis in vivo (fewer calcitonin receptor–positive multinucleated cells and fewer transcripts for cathepsin K, matrix metalloproteinase 9, and TRAP in joints) and reduced serum levels of C-terminal telopeptide of type I collagen. Conclusion GzmA contributes to the joint destruction of RA partly by promoting osteoclast differentiation.

8 figures, 1 table.-- Electronic supplementary information available, If not properly regulated, the inflammatory immune response can promote carcinogenesis, as evident in colorectal cancer (CRC). Aiming to gain mechanistic insight into the link between inflammation and CRC, we perform transcriptomics analysis of human CRC, identifying a strong correlation between expression of the serine protease granzyme A (GzmA) and inflammation. In a dextran sodium sulfate and azoxymethane (DSS/AOM) mouse model, deficiency and pharmacological inhibition of extracellular GzmA both attenuate gut inflammation and prevent CRC development, including the initial steps of cell transformation and epithelial-to-mesenchymal transition. Mechanistically, extracellular GzmA induces NF-κB-dependent IL-6 production in macrophages, which in turn promotes STAT3 activation in cultured CRC cells. Accordingly, colon tissues from DSS/AOM-treated, GzmA-deficient animals present reduced levels of pSTAT3. By identifying GzmA as a proinflammatory protease that promotes CRC development, these findings provide information on mechanisms that link immune cell infiltration to cancer progression and present GzmA as a therapeutic target for CRC., This work was supported in part by FEDER/Gobierno de Aragón (group B29), Ministerio de Economia y Competitividad (SAF2014-54763-C2-1 and SAF2017-83120-C2-1-R to J.P. and SAF2014-54763-C2-2-R to E.M.G.), and Instituto de Salud Carlos III (PI13/00864 to L.M.-L.). Predoctoral grants/contracts from Fundacion Santander/Universidad de Zaragoza (to L.S. and M.A.A.), Gobierno de Aragon (to I.U.-M., L.C., L.S., and P.J.-S.), and FPU/Ministerio de Educación, Cultura y Deportes (to P.M.L.). I.U.-M. was supported by Fondo Garantía Empleo Juvenil/INAEM. M.A.A. has a Juan de la Cierva contract (Ministerio de Ciencia, Innovación y Universidades). J.P. was supported by Fundación Aragon I+D (ARAID).

Gliotoxin (GT), a secondary metabolite produced by Aspergillus molds, has been proposed as a potential anti-tumor agent. Here we have developed a nanoparticle approach to enhance delivery of GT in tumor cells and establish a basis for its potential use as therapeutical drug. GT bound to magnetic nanoparticles (MNPs) retained a high anti-tumor activity, correlating with efficient intracellular delivery, which was increased in the presence of glucose. Our results show that the attachment of GT to MNPs by covalent bonding enhances intracellular GT delivery without affecting its biological activity. This finding represents the first step to use this potent anti-tumor agent in the treatment of cancer., This work was supported by Fondo Social Europeo (FSE; Gobierno de Aragón), ASPANOA and by grants SAF2017-83120-C2-1-R, SAF2014-54763-C2-1-R, SAF2014-54763-C2-2-R from Spanish Ministry of Economy and Competitivenes. LC was granted by a DGA predoctoral contract, EP by a Juan de la Cierva Incorporacion fellowship program (IJCI-2016-30706) and MA by a Juan de la Cierva Formación fellowship program (FJCI-2017-31629), We acknowledge support by the CSIC Open Access Publication Initiative through its Unit of Information Resources for Research (URICI)

Gliotoxin (GT) is a fungal secondary metabolite that has attracted great interest due to its high biological activity since it was discovered by the 1930s. An inactive derivative of this molecule, bis(methylthio)gliotoxin (bmGT), has been proposed as an invasive aspergillosis (IA) biomarker. Nevertheless, studies regarding bmGT production among common opportunistic fungi, including the Aspergillus genus, are scarce and sometimes discordant. As previously reported, bmGT is produced from GT by a methyl-transferase, named as GtmA, as a negative feedback regulatory system of GT production. In order to analyze the potential of bmGT detection to enable identification of infections caused by different members of the Aspergillus genus we have assessed bmGT production within the genus Aspergillus, including A, fumigatus, A. niger, A. nidulans, and A. flavus, and its correlation with gtmA presence. In order to validate the relevance of our in vitro findings, we compared bmGT during in vitro culture with the presence of bmGT in sera of patients from whom the Aspergillus spp. were isolated. Our results indicate that most A. fumigatus isolates produce GT and bmGT both in vitro and in vivo. In contrast, A. niger and A. nidulans were not able to produce GT or bmGT, although A. niger produced bmGT from a exogenous GT source. The frequency and amount of bmGT production in A. terreus and A. flavus isolates in vitro was lower than in A. fumigatus. Our results suggest that this defect could be related to the in vitro culture conditions, since isolates that did not produce bmGT in vitro were able to synthetize it in vivo. In summary, our study indicates that bmGT could be very useful to specifically detect the presence of A. fumigatus, the most prevalent agent causing IA. Concerning A. terreus and A. flavus a higher number of analyses from sera from infected patients will be required to reach a useful conclusion., This work was supported by Fondo Social Europeo (FSE; Gobierno de Aragón) and by grants MAT2011-26851-C02-02,SAF2014- 54763-C2-1-R, SAF2014-54763-C2-2-R from Spanish Ministry of Economy and Competitiveness. JP was supported by Aragón ICD (ARAID). MV-G was granted by a Río Hortega contract of National Institute of Health Carlos III (CM16/00236), We kindly acknowledge Dr. J. F. Meis from Canisius-Wilhelmina Hospital, Nijmegen (Netherlands) and Dr. E. Bouza from Gregorio Marañón University Hospital, Madrid (Spain) for providing clinical isolates from several Aspergillus species and from cryptic species, respectively. We would like to acknowledge ASPANOA (Asociacion de Padres de Niños con Cáncer de Aragón) for its support to develop this work.

[Background]: The special physicochemical properties of gold nanoprisms make them very useful for biomedical applications including biosensing and cancer therapy. However, it is not clear how gold nanoprisms may affect cellular physiology including viability and other critical functions. We report a multiparametric investigation on the impact of gold-nanoprisms on mice and human, transformed and primary cells as well as tissue distribution and toxicity in vivo after parental injection., [Methods]: Cellular uptake of the gold-nanoprisms (NPRs) and the most crucial parameters of cell fitness such as generation of reactive oxygen species (ROS), mitochondria membrane potential, cell morphology and apoptosis were systematically assayed in cells. Organ distribution and toxicity including inflammatory response were analysed in vivo in mice at 3 days or 4 months after parental administration., [Results]: Internalized gold-nanoprisms have a significant impact in cell morphology, mitochondrial function and ROS production, which however do not affect the potential of cells to proliferate and form colonies. In vivo NPRs were only detected in spleen and liver at 3 days and 4 months after administration, which correlated with some changes in tissue architecture. However, the main serum biochemical markers of organ damage and inflammation (TNFα and IFNγ) remained unaltered even after 4 months. In addition, animals did not show any macroscopic sign of toxicity and remained healthy during all the study period., [Conclusion]: Our data indicate that these gold-nanoprisms are neither cytotoxic nor cytostatic in transformed and primary cells, and suggest that extensive parameters should be analysed in different cell types to draw useful conclusions on nanomaterials safety. Moreover, although there is a tendency for the NPRs to accumulate in liver and spleen, there is no observable negative impact on animal health., This work was supported by the MAT2011–26851-CO2–01, MAT2011–26851-CO2–02, SAF2011–25390, SAF2014–54763-C2–1-R and SAF2014–54763-C2–2-R - projects of the Spanish Ministry of Science and Innovation, PIE201460I019 (CSIC), the grant ERC-Starting Grant 239931-NANOPUZZLE project, ERC-PoC 754609 HOTFLOW project, Fondo Social Europeo (FSE; Gobierno de Aragón) and the Consellería de Cultura, Educación e Ordenación Universitaria (Centro singular de investigación de Galicia accreditation 2016–2019, ED431G/09) and the European Regional Development Fund (ERDF). P.d.P., J.M.F., J.P. thank ARAID for financial support, B.P. thanks the Alexander von Humboldt Foundation for a fellowship and M.M. acknowledges financial support from European Union’s Horizon 2020 research and innovation programme under the Marie Skłodowska-Curie grant agreement No. 660228.

A repeatable separation of polystyrenes according to MW, from 1920 to 520000 u.m.a, has been obtained under adsorption conditions using a method that comprises the use of Lichrospher HPTLC plates, and a controlled, isocratic elution with a 78:22 (v/v) mixture of cyclohexane (Cy)-tetrahydrofuran (THF). Likewise, UV-densitometric quantification of polystyrenes in mixtures can be achieved, by an intra-plate or an inter-plate procedure, using the corresponding polystyrene calibration curve. In the case or overlapped, unresolved peaks, an average curve of the corresponding polystyrenes can be used. Migration of polystyrenes strongly varies with slight variations in the relative proportion of Cy and THF in the mobile phase. This allows different ranges of MW to be separated as a function of mobile phase composition. Other factors influencing repeatability have been identified. Some reasons have been advanced to explain the current lack of activity in the research on polymer characterization by HPTLC. Old literature results concerning polystyrene separation have also been discussed in the light of modern HPTLC instrumentation. Developed method provides similar information on Molecular Weight Distribution (MWD) to that obtained using Gel Permeation Chromatography (GPC). Advantages and limitations of HPTLC for obtaining polymer MWD have also been discussed., Authors thank the Spanish Ministerio de Ciencia e Innovación (MICINN) and FEDER (UE) for financial support (Plan Nacional de I+D+I, project CTQ2008-00959)

BACKGROUND Only little detailed information has been published by a small number of centers on experiences with the technical aspects of "in vitro" large-scale graft manipulation technologies. METHODS We report our experiences with the graft engineering procedures performed and the results obtained after T cell depletion. We have analyzed data from 212 procedures (108 CD34+ cell selection and 104 CD3+/CD19+ cell depletion). RESULTS We conclude that the final cell products after selection or depletion were completely different with regard to CD34+ cell purity (95.8% vs. 1.52%). The CD34+ cell recovery after CD34+ cell selection is negatively affected when the initial leukocyte and/or CD34+ cell counts exceed the threshold defined by the manufacturer (68.9% vs. 45.2%, p < 0.01). However, the cell count threshold defined for the depletion technique could be exceeded without seriously affecting final results (86.1% vs. 86.4% for those with more or less than 40 x 109 leukocyte before the procedure; p = 0.7). Another important conclusion from this study is that in both CD34+ cell selection and CD3+/CD19+ cell depletion better results were reached after having gained experience by performing the procedures several times. This means that a learning process can be expected when using these in vitro graft manipulation procedures. CONCLUSIONS It is extremely important to have experienced staff to perform these procedures. The expected results are different with each procedure so the decision on which of these T cell depletion approaches are used should be based on the characteristics of the final product wanted.

Changes in fluorescence emission due to non-covalent analyte-fluorophore interactions in silica gel plates are studied and used as a general detection procedure for thin-layer chromatography (TLC). The presence of the analyte modifies the microenvironment of the fluorophore and thus changes the balance between radiative (k(r)) and non-radiative (k(nr)) emission constants. A model is proposed for analyte-fluorophore induced electrostatic interactions, which depend on analyte polarizability and are responsible for fluorescence enhancements. As consequence of these induced interactions, the analyte creates an apolar environment that prevents non-fluorescent decay mechanisms, decreasing k(nr). On the other hand, the effect of an increase in refractive index on k(r) is investigated, as it contributes to some extent to fluorescence enhancements in silica gel medium. Changes in fluorescence emission should be regarded as a general property of fluorophores in the presence of analytes, and criteria that fluorophores should meet to be used as sensitive TLC probes are discussed here.

Changes in emission of berberine cation, induced by non-covalent interactions with lipids on silica gel plates, can be used for detecting and quantifying lipids using fluorescence scanning densitometry in HPTLC analysis. This procedure, referred to as fluorescence detection by intensity changes (FDIC) has been used here in combination with automated multiple development (HPTLC/AMD), a gradient-based separation HPTLC technique, for separating, detecting and quantifying lipids from different families. Three different HPTLC/AMD gradient schemes have been developed for separating: neutral lipid families and steryl glycosides; different sphingolipids; and sphingosine-sphinganine mixtures. Fluorescent molar responses of studied lipids, and differences in response among different lipid families have been rationalized in the light of a previously proposed model of FDIC response, which is based on ion-induced dipole interactions between the fluorophore and the analyte. Likewise, computational calculations using molecular mechanics have also been a complementary useful tool to explain high FDIC responses of cholesteryl and steryl-derivatives, and moderate responses of sphingolipids. An explanation for the high FDIC response of cholesterol, whose limit of detection (LOD) is 5 ng, has been proposed. Advantages and limitations of FDIC application have also been discussed.

Berberine and coralyne experience either fluorescence enhancement or quenching when long hydrocarbon chain compounds (e.g., n-alkanes or alcohols) are added to their solutions, depending on solvent polarity. In polar solvents, as methanol or acetonitrile, the added compounds provide an apolar microenvironment that hinders alternative relaxation mechanisms, favouring fluorescence emission. However, alkane additions produce quenching in dichloromethane, which has been explained taking into account ion pairing between cationic fluorophore and counterion. The strong quenching measured after alcohol additions in dichloromethane suggests reversed micelle formation. Procedures and results described here may find practical applications in the development of analytical methods.

spFRET (single-pair fluorescence resonance energy transfer) with organic fluorophores has been used to demonstrate rotation of the subunits γ and ε in membrane-integrated FoF1 during proton transport-coupled ATP synthesis. Owing to the high light intensities used in single-molecule spectroscopy, organic fluorophores show a high probability for photobleaching. Luminescent CdSe/ZnS nanocrystals with a hydrophilic shell have been covalently bound to FoF1 either to the stator subunit b or to the rotor subunit c. TIRFM (total internal reflection microscopy) shows that covalent binding of the QD (quantum dot) via cysteine to FoF1 leads to a significant decrease in the blinking probability in the microsecond-to-second time range. This effect allows the observation of subunit movements in an extended time range. If the QD is bound to the rotor subunit c, the fluorescence anisotropy shows fluctuations in the presence of ATP, in contrast with the constant anisotropy observed in the absence of ATP.

The alb1 ( pksP ) gene has been reported as a virulence factor controlling the pigmentation and morphology of conidia in Aspergillus fumigatus . A recent report suggested that laeA regulates alb1 expression and conidial morphology but not pigmentation in the A. fumigatus strain AF293. laeA has also been reported to regulate the synthesis of secondary metabolites, such as gliotoxin. We compared the role of laeA in the regulation of conidial morphology and the expression of alb1 and gliP in strains B-5233 and AF293, which differ in colony morphology and nutritional requirements. Deletion of laeA did not affect conidial morphology or pigmentation in these strains, suggesting that laeA is not involved in alb1 regulation during conidial morphogenesis. Deletion of laeA , however, caused down-regulation of alb1 during mycelial growth in a liquid medium. Transcription of gliP , involved in the synthesis of gliotoxin, was drastically reduced in B-5233 laeAΔ , and the gliotoxin level found in the culture filtrates was 20% of wild-type concentrations. While up-regulation of gliP in AF293 was comparable to that in B-5233, the relative mRNA level in AF293 laeAΔ was about fourfold lower than that in B-5233 laeAΔ . Strain B-5233 laeAΔ caused slower onset of fatal infection in mice relative to that with B-5233. Histopathology of sections from lungs of infected mice corroborated the survival data. Culture filtrates from B-5233 laeAΔ caused reduced death in thymoma cells and were less inhibitory to a respiratory burst of neutrophils than culture filtrates from B-5233. Our results suggest that while laeA is not involved in the regulation of alb1 function in conidial morphology, it regulates the synthesis of gliotoxin and the virulence of A. fumigatus.

Early and accurate diagnosis of invasive aspergillosis (IA) is one of themost critical steps needed to efficiently treat the infection and reduce the high mortality rates that can occur. We have previously found that the Aspergillus spp. secondary metabolite, bis(methylthio)gliotoxin (bmGT), can be detected in the serum from patients with possible/probable IA. Thus, it could be used as a diagnosis marker of the infection. However, there is no data available concerning the sensitivity, specificity and performance of bmGT to detect the infection. Here,we have performed a prospective study comparing bmGT detection with galactomannan (GM), the most frequently used and adopted approach for IA diagnosis, in 357 sera from 90 episodes of patients at risk of IA. Our results, involving 79 patients that finally met inclusion criteria, suggest that bmGT presents higher sensitivity and positive predictive value (PPV) than GM and similar specificity and negative predictive value (NPV). Importantly, the combination of GM and bmGT increased the PPV (100 %) and NPV (97.5 %) of the individual biomarkers, demonstrating its potential utility in empirical antifungal treatment guidance and withdrawal. These results indicate that bmGT could be a good biomarker candidate for IA diagnosis and, in combination with GM, could result in highly specific diagnosis of IA and management of patients at risk of infection., This work has been supported by Fondo Social Europeo (FSE/Gobierno de Aragón) and ARAID Foundation (J.P.)

Improved methods for separation and quantitative determination of hydrocarbon types from gas oil have been developed, which were based on high-performance thin-layer chromatography with ultraviolet and fluorescence scanning densitometry using horizontal elution. One of the methods allows the separation, detection, and determination of alkanes and naphthenes to be carried out, using berberine-impregnated silica gel HPTLC plates, elution with n-hexane, and berberine-induced fluorescence detection at 365 nm. Another developed method allows total aromatics to be determined using silica gel HPTLC plates by elution with n-hexane and acetone, and UV detection. In turn, PACs over three aromatic rings can be determined on either silica gel or caffeine-impregnated silica gel HPTLC plates, elution with n-hexane, and selective detection using native fluorescence at 365 nm. Concentrations lower than 5 wt% can be determined using this technique. In addition, a technique for an efficient, baseline-resolved separation of a gas oil according to the number of aromatics rings (mono + di-, tri-, and polyaromatic compounds with more than three rings) is presented here. This technique involves a multistep elution on a mixed (silica gel and caffeine-impregnated silica gel HPTLC plate) using a counter-elution device, and UV detection.

Different methodologies, based on planar chromatography/detection with densitometry, have been used to analyse compound classes (also known as hydrocarbon group type (HGT)) in samples coming from petroleum and coal conversion. The main problem encountered to analyse these samples is the choice of standard: because of the high variability of the signal that is dependent of molecular structure, one pure hydrocarbon does not reflect the response of a mixture. However, a step based on thin layer chromatography at preparative scale has allowed the fractionation of sample to obtain its derived standards. After this, alkanes have been quantified by fluorescence in presence of berberine sulfate and aromatic compounds have been detected by UV after separation by high performance thin layer chromatography (HPTLC) at analytical scale. The feasibility of the planar chromatography has been tested. The quantitative results obtained for different samples are in agreement with those provided using well-established techniques in the petrochemical industry and the coal-derived product (CDP) analysis.

Two alternative methods, based on Thin-Layer Chromatography (TLC) with Fluorescence Scanning Densitometry have been developed for characterization of heavy liquids from copyrolysis of different kinds of biomass and plastics in autoclaves under inert atmosphere.

7 Figuras, 5 Tablas, The interaction between leukocyte function-associated antigen-1(LFA-1) and intercellular adhesion molecule-1 (ICAM-1) plays a pivotal role in cellular adhesion including the extravasation and inflammatory response of leukocytes, and also in theformation of immunological synapse. However, irregular expressions of LFA-1 or ICAM-1 or both may lead to autoimmune diseases, metastasis cancer, etc. Thus, the LFA-1/ICAM-1 interaction may serve as a potential therapeutic target for thetreatment of these diseases. Here, we developed one simple ‘in solution’ steady state fluorescence resonance energytransfer (FRET) technique to obtain the dissociation constant (Kd) of the interaction between LFA-1 and ICAM-1. Moreover, we developed the assay into a screening platform to identify peptides and small molecules that inhibit the LFA-1/ICAM-1interaction. For the FRET pair, we used Alexa Fluor 488-LFA-1 conjugate as donor and Alexa Fluor 555-human recombinant ICAM-1 (D1-D2-Fc) as acceptor. From our quantitative FRET analysis, the Kd between LFA-1 and D1-D2-Fc was determined to be 17.9361.34 nM. Both the Kd determination and screening assay were performed in a 96-well plate platform, providing the opportunity to develop it into a high-throughput assay. This is the first reported work which applies FRET based technique to determine Kdas well as classifying inhibitors of the LFA-1/ICAM-1 interaction, SC SH AK AC were jointly supported by the National Science Council, Taiwan, ROC (Spain-Taiwan Collaborative Research Project, Project No. NSC99-2923- E-010-001-MY3), the Top University Project from Taiwan Ministry of Education while DN MPD JP EG were supported by the Spanish National Science Council (CSIC) (2009tw0034), SAF2011-25390 from Spanish Ministry of Economy and Competitiveness. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.

Synthetic peptides have been developed for therapeutic applications for decades. The therapeutic efficacy often depends not only on the stabilization of the peptides but also on their binding specificity and affinity to the target molecules to interfere with designated molecular interaction. In this study, the binding affinity of human intercellular adhesion molecule 1 (ICAM-1) chimera and leukocyte function-associated antigen-1 (LFA-1) derived peptides was measured by surface plasmon resonance (SPR) detection, and the results were compared with that of the interaction (of ICAM-1) with the LFA-1 whole protein. To mimic diverse pathological situations in vivo where a low pH has been reported, we studied pH regulated binding affinity of ICAM-1/LFA-1 at pH 7.4, 6.5, and 4.0 without and with magnesium ion. We have found that the binding affinity of LFA-1 whole protein and ICAM-1 increases significantly as the environmental pH decreases, regardless of the absence or the presence of magnesium ion. The affinity of different (LFA-1) derived peptides also depends on the pH, although in all cases the peptides retain its ability to inhibit ICAM-1/LFA-1 interaction. The biomedical relevance of these data has been confirmed using a cell aggregation assay, suggesting that LFA-1 derived peptides show great potential for peptide drug development with a wide functional window of pH range for potential applications in LFA-1 related tumor therapy and autoimmune disease treatment.

The virulence factor gliotoxin (GT) and its inactive derivative, bis(methylthio)gliotoxin (bmGT), are produced by pathogens of the genus Aspergillus. Here we report the detection of GT and bmGT in serum of humans at risk of invasive aspergillosis (IA) as well as in cultures of fungal isolates derived from patients with proven infection with A. fumigatus. Although both compounds are readily recoverable from spiked human serum or plasma, only bmGT is retained in whole blood, indicating that bmGT may be the better marker for in vivo detection. Accordingly, bmGT was found more frequently than GT in samples from patients at risk of IA and in cultures of clinical isolates of A. fumigatus. In some cases, bmGT was detected before mycologic evidence of infection was gained. Importantly, neither GT nor bmGT was found in serum from healthy donors or from neutropenic patients without any sign of infection. Thus, bmGT presence might provide a more reliable indicator of A. fumigatus infections than GT. Due to its simplicity and sensitivity, a diagnostic technology based on this test could be easily adopted in clinical laboratories to help in the diagnosis of this often fatal fungal infection.

Luminescent semiconductor nanocrystals (quantum dots, QD) have unique photo-physical properties: high photostability, brightness and narrow size-tunable fluorescence spectra. Due to their unique properties, QD-based single molecule studies have become increasingly more popular during the last years. However QDs show a strong blinking effect (random and intermittent light emission), which may limit their use in single molecule fluorescence studies. QD blinking has been widely studied and some hypotheses have been done to explain this effect. Here we summarise what is known about the blinking effect in QDs, how this phenomenon may affect single molecule studies and, on the other hand, how the “on”/“off” states can be exploited in diverse experimental settings. In addition, we present results showing that site-directed binding of QD to cysteine residues of proteins reduces the blinking effect. This option opens a new possibility of using QDs to study protein–protein interactions and dynamics by single molecule fluorescence without modifying the chemical composition of the solution or the QD surface., Authors thank Gobierno de Aragón-Fondo Social Europeo for financial support. EMG thanks Deutsche Forschungsgemeinschaft for a grant.

3 Figuras, H+-ATPsynthases couple a transmembrane proton transport with ATP synthesis and ATP hydrolysis. Previously, the relative subunit movement during this process has been measured by fluorescence resonance energy transfer (FRET) between two organic fluorophores covalently bound to different subunits. To improve the photophysical stability, a luminescent CdSe/ZnS nanocrystal (quantum dot) was bound to the enzyme and an organic fluorophore, Alexa568, was used as fluorescence acceptor. Single-molecule spectroscopy with the membrane integrated labeled H+-ATPsynthase was carried out. Single-pair FRET indicates three different conformations of the enzyme. During ATP hydrolysis relative intramolecular subunit movements are observed in real time., Eva M. Galvez was supported by the DeutscheForschungsgemeinschaft (DFG).

Gliotoxin is an immunosuppressive mycotoxin long suspected to be a potential virulence factor of Aspergillus fumigatus . Recent studies using mutants lacking gliotoxin production, however, suggested that the mycotoxin is not important for pathogenesis of A. fumigatus in neutropenic mice resulting from treatment with cyclophosphomide and hydrocortisone. In this study, we report on the pathobiological role of gliotoxin in two different mouse strains, 129/Sv and BALB/c, that were immunosuppressed by hydrocortisone alone to avoid neutropenia. These strains of mice were infected using the isogenic set of a wild type strain (B-5233) and its mutant strain ( gliP Δ) and the the glip reconstituted strain ( gliP R ). The gliP gene encodes a nonribosomal peptide synthase that catalyzes the first step in gliotoxin biosynthesis. The gliP Δ strain was significantly less virulent than strain B-5233 or gliP R in both mouse models. In vitro assays with culture filtrates (CFs) of B-5233, gliP Δ, and gliP R strains showed the following: (i) deletion of gliP abrogated gliotoxin production, as determined by high-performance liquid chromatography analysis; (ii) unlike the CFs from strains B-5233 and gliP R , gliP Δ CFs failed to induce proapoptotic processes in EL4 thymoma cells, as tested by Bak conformational change, mitochondrial-membrane potential disruption, superoxide production, caspase 3 activation, and phosphatidylserine translocation. Furthermore, superoxide production in human neutrophils was strongly inhibited by CFs from strain B-5233 and the gliP R strain, but not the gliP Δ strain. Our study confirms that gliotoxin is an important virulence determinant of A. fumigatus and that the type of immunosuppression regimen used is important to reveal the pathogenic potential of gliotoxin.

6 Figures, 2 Tables, A large number of analytes, including non-fluorescent ones, can be sensitively detected by fluorescence scanning densitometry using silica gel HPTLC plates impregnated with a solution of coralyne cation. This is carried out by the variation, increase or decrease, that the corresponding analyte induces on native coralyne emission at a given excitation wavelength. A similar phenomenon was previously described for berberine cation, and Reichardt's dye probes. However, the sensitivity of coralyne in HPTLC detection of non-fluorescent, structurally different analytes (e.g., long-chain alkanes, alcohols, alkylbromides, neutral lipids) is superior to that of the above-mentioned probes. In this work, the analytical viability of this phenomenon for HPTLC detection using coralyne as a probe is explored, and fluorescent responses of a number of analytes on the coralyne system are rationalized in the light of a previously proposed model. This establishes that the resulting intensity for a probe in the presence of a given compound can be explained as a balance between radiative (contribution of non-specific interactions) and non-radiative processes (specific interactions), the latter producing fluorescence quenching. Experimental results and proposed model suggest that this phenomenon may be general for practically all kinds of analytes., The authors thank the Spanish Ministerio de Educación y Ciencia (MEC) and the Diputación General de Aragón (DGA) for financial support (projects CTQ2005-00227/PPQ and PM010, respectively).

Aspergillus fumigatus infections cause high levels of morbidity and mortality in immunocompromised patients. Gliotoxin (GT), a secondary metabolite, is cytotoxic for mammalian cells, but the molecular basis and biological relevance of this toxicity remain speculative. We show that GT induces apoptotic cell death by activating the proapoptotic Bcl-2 family member Bak, but not Bax, to elicit the generation of reactive oxygen species, the mitochondrial release of apoptogenic factors, and caspase-3 activation. Activation of Bak by GT is direct, as GT triggers in vitro a dose-dependent release of cytochrome c from purified mitochondria isolated from wild-type and Bax- but not Bak-deficient cells. Resistance to A. fumigatus of mice lacking Bak compared to wild-type mice demonstrates the in vivo relevance of this GT-induced apoptotic pathway involving Bak and suggests a correlation between GT production and virulence. The elucidation of the molecular basis opens new strategies for the development of therapeutic regimens to combat A. fumigatus and related fungal infections.

6 Figuras., Many chemical compounds, including nonfluorescent ones, induce changes in the fluorescence spectra of certain probes, such as berberine cation and Reichardt's betaine, both in the absence and the presence of solvent, that affect almost exclusively emission intensity. In this work, the application of fluorescence detection by intensity changes (FDIC) to HPLC and TLC chromatographic systems with fluorescence detectors has been studied. FDIC detection is of special interest in detecting nonfluorescent analytes, either in HPLC or in TLC mode. It does not involve covalent interactions, and the dielectric permittivity (ε) of the medium plays an important role. The balance between nonspecific and specific interactions produces either an increase or a decrease in fluorescence intensity. Therefore, the influence of chromatographic conditions and chemical structure of analytes on the sign and magnitude of fluorescence peaks for sample detection in HPLC and TLC systems has been discussed. In general, probe nature and concentration determine response and detection sensitivity for a given sample in TLC and HPLC. As solubility and fluorescence properties in solvents determine the operating conditions for a FDIC probe in HPLC mode, nature and flows of mobile phase and solvent are important for chromatographic response and detection sensitivity., Authors thank the Spanish Ministerio de Ciencia y Tecnología (MCyT) and Ministerio de Educación y Ciencia for financial support (projects PPQ2001-2388 and CTQ2005-00227/PPQ). E.M.G. acknowledges MCyT for a grant.

Petroleum is fractionated according to its boiling point by distillation methods. Depending on the boiling point range of the sample, fractionated products fall into three main categories: light, middle and heavy distillates. Middle distillates (from approximately 150°C to 400°C, which approximately corresponds to C9-C24) are mostly used for heating and transportation fuels (e.g., diesel, jet fuel, gas oil, aviation turbine oils, kerosene).

A straight run gas oil has been hydrotreated with a commercial CoMo/Al2O3 catalyst, under variable conditions of severity, in order to yield processed products containing a variable amount of residual sulfur. These products have been characterized by simulated distillation, gas chromatography with sulfur-selective detection (GC−SCD), and thin-layer chromatography. The sulfur compounds have been grouped into distinct representative families. The rate constants for the reaction of desulfurization of the considered groups and the apparent rate order with respect to some individual sulfur compounds have been determined. The following hydrocarbon groups have been determined in the hydrotreated products by analytical thin-layer chromatography−densitometry: alkanes, cycloalkanes, total aromatics, and polyaromatic compounds (PACs). The straight run gas oil has been submitted to fractionation by preparative thin-layer chromatography, and the resulting fractions of alkanes, cycloalkanes, and aromatics have been ch...

Methods based on fluorescence technology have been widely employed to analyse protein function, dynamics, interactions and folding in cell free systems as well as in intact cells. Fluorescence resonance energy transfer (FRET) is a unique technique to precisely calculate inter- and intra-molecular distances in proteins and thus to study protein-protein/peptide interaction, folding and conformational changes. However detailed studies of these processes at the single molecule level and/or in intact cells, requires fluorescence dyes with high stability and quantum yield. During the last six years fluorescent nanocrystals (quantum dots) have been developed as potent and promising fluorescence dyes that fulfil the prerequisites to study protein function in FRET based assays. It is the aim of this short review to summarise the benefits and drawbacks of QDs in the study of protein function and dynamics in biological systems.

Hydrocarbon group-type analysis (HGTA) is a common technique for characterization of complex mixtures derived from raw materials such as coal, petroleum, or biomass. In these and other, related, samples, trying to achieve extensive separation of all the components would be very difficult at least, and most of the relevant properties of the samples can be related to the amounts of the different types of hydrocarbon. Groups of interest depend mainly on the nature of the sample, and some kind of liquid chromatography is usually involved in the most common HGTA methods. Thin-layer chromatography (TLC) can nowadays usually be used instead of HPLC, resulting in several advantages in terms of speed, cost, and general convenience. Detection and quantification of the different peaks might involve the use of special equipment, e.g. in TLC-flame ionization detection (FID) methods, although it can also be accomplished by means of UV and fluorescence scanning densitometry. In this paper, we describe a series of TLC-ba...