Metal Ions Trigger the Gelation of Cysteine-Containing Peptide-Appended Coordination Cages

We report a series of coordination cages that incorporate peptide chains at their vertices, prepared through subcomponent self-assembly. Three distinct heterochiral tripeptide subcomponents were incorporated, each exhibiting an L-D-L stereoconfiguration. Through this approach, we prepared and characterized three tetrahedral metal-peptide cages that incorporate thiol and methylthio groups. The gelation of these cages wasprobed through the binding of additional metal ions, with the metal-peptide cages acting as junctions, owing to the presence of sulfur atoms on the peripheral peptides. Gels were obtained with cages bearing cysteine at the C-terminus. Our strategy for developing functional metal-coordinated supramolecular gels with a modular design may result in the development of materials useful for chemical separations or drug delivery.

Self-assembling tripeptide forming water-bound channels and hydrogels

D-Ser(tBu)-L-Phe-L-Trp is described as a self-assembling tripeptide that yields nanofibrillar hydrogels at physiological conditions (phosphate buffer at pH 7.4). The peptide is characterized by several spectroscopic methods, such as circular dichroism and fluorescence, oscillatory rheometry, and transmission electron microscopy. Single-crystal X-ray diffraction reveals supramolecular packing into water-bound channels and allows the visualization of the intermolecular interactions holding together peptide stacks.

Electron spin polarization in supramolecular polymers with complex pathways

Mastering the manipulation of the electron spin plays a crucial role in comprehending the behavior of organic materials in several applications, such as asymmetric catalysis, chiroptical switches, and electronic devices. A promising avenue for achieving such precise control lies in the Chiral Induced Spin Selectivity (CISS) effect, where electrons with a favored spin exhibit preferential transport through chiral assemblies of specific handedness. Chiral supramolecular polymers emerge as excellent candidates for exploring the CISS effect due to their ability to modulate their helical structure through noncovalent interactions. In this context, systems capable of responding to external stimuli are particularly intriguing, sometimes even displaying chirality inversion. This study unveils spin selectivity in chiral supramolecular polymers, derived from single enantiomers, through scanning tunneling microscopy conducted in scanning tunneling spectroscopy mode. Following two distinct sample preparation protocols for each enantiomer, we generate supramolecular polymers with opposite handedness and specific spin transport characteristics. Our primary focus centers on chiral π-conjugated building blocks, with the aim of advancing novel systems that can inspire the organic spintronics community from a supramolecular chemistry level.

Integrating principles and tools of decision science into value-driven watershed planning for compensatory mitigation

Several environmental policies strive to restore impaired ecosystems and could benefit from a consistent and transparent process-codeveloped with key stakeholders-to prioritize impaired ecosystems for restoration activities. The Clean Water Act, for example, establishes reallocation mechanisms to transfer ecosystem services from sites of disturbance to compensation sites to offset aquatic resource functions that are unavoidably lost through land development. However, planning for the prioritization of compensatory mitigation areas is often hampered by decision-making processes that fall into a myopic decision frame because they are not coproduced with stakeholders. In this study, we partnered with domain experts from the North Carolina Division of Mitigation Services to codevelop a real-world decision framework to prioritize catchments by potential for the development of mitigation projects following principles of a structured decision-making process and knowledge coproduction. Following an iterative decision analysis cycle, domain experts revised foundational components of the decision framework and progressively added complexity and realism as they gained additional insights or more information became available. Through the course of facilitated in-person and remote interactions, the codevelopment of a decision framework produced three main "breakthroughs" from the perspective of the stakeholder group: (a) recognition of the problem as a multiobjective decision driven by several values in addition to biogeophysical goals (e.g., functional uplift, restoring or enhancing lost functionality of ecosystems); (b) that the decision comprises a linked and sequential planning-to-implementation process; and (c) future risk associated with land-use and climate change must be considered. We also present an interactive tool for "on-the-fly" assessment of alternatives and tradeoff analysis, allowing domain experts to quickly test, react to, and revise prioritization strategies. The decision framework described in this study is not limited to the prioritization of compensatory mitigation activities across North Carolina but rather serves as a framework to prioritize a wide range of restoration, conservation, and resource allocation activities in similar environmental contexts across the nation.

Afternoon Tea Hemichorea

A 78 year old lady, with a past medical history of hypertension, presented to the Accident & Emergency department after a sudden onset of right sided involuntary movements while she was having afternoon tea with her friends. Examination showed isolated unilateral chorea, affecting the right arm and leg (video). Her blood glucose and sodium levels were normal. The MRI head scan showed a left globus pallidus infarct (figure 1). Tetrabenazine was prescribed with very good response, and weaned off after 4 weeks. Hyperkinetic movement disorders are uncommon in acute stroke (1%)1. Lesions in regions functionally connected to the posterolateral putamen are implicated in hyperkinetic movement disorders2. The differential diagnosis includes hyperglycaemia, hyponatraemia and drug-induced chorea. In cases of sudden onset, it is important to recognise stroke as a possible cause to avoid missing reperfusion therapy opportunities

Chirality inversion in hydrogen-bonded rhodanine-oligothiophene derivatives by solvent and temperature

The self-assembly process of hydrogen-bonded quinquethiophene-rhodanine derivatives has been explored as a function of solvent and temperature. We demonstrate the divergent supramolecular chirality emerging from a single enantiomer by subtle changes in solvent mixtures and sample preparation protocol. Spectroscopic techniques have proved the presence of aggregates where H-bonding interactions play a crucial role.

The Importance of Spin State in Chiral Supramolecular Electronics

The field of spintronics explores how magnetic fields can influence the properties of organic and inorganic materials by controlling their electron’s spins. In this sense, organic materials are very attractive since they have small spin-orbit coupling, allowing long-range spin-coherence over times and distances longer than in conventional metals or semiconductors. Usually, the small spin-orbit coupling means that organic materials cannot be used for spin injection, requiring ferromagnetic electrodes. However, chiral molecules have been demonstrated to behave as spin filters upon light illumination in the phenomenon described as chirality-induced spin selectivity (CISS) effect. This means that electrons of certain spin can go through chiral assemblies of molecules preferentially in one direction depending on their handedness. This is possible because the lack of inversion symmetry in chiral molecules couples with the electron’s spin and its linear momentum so the molecules transmit the one preferred spin. In this respect, chiral semiconductors have great potential in the field of organic electronics since when charge carriers are created, a preferred spin could be transmitted through a determined handedness structure. The exploration of the CISS effect in chiral supramolecular semiconductors could add greatly to the efforts made by the organic electronics community since charge recombination could be diminished and charge transport improved when the spins are preferentially guided in one specific direction. This review outlines the advances in supramolecular chiral semiconductors regarding their spin state and its influence on the final electronic properties.

Autofluorescence of Amyloids Determined by Enantiomeric Composition of Peptides

Amyloid fibrils are peptide or protein aggregates possessing a cross-β-sheet structure. They possess intrinsic fluorescence property, which is still not fully understood. Herein, we compare structural and optical properties of fibrils formed from L- and D-enantiomers of the (105–115) fragment of transthyretin (TTR) and from their racemic mixture. Our results show that autofluorescence of fibrils obtained from enantiomers differs from that of fibrils from the racemic mixture. In order to elucidate the origin of observed differences, we analyzed the structure and morphology of fibrils and showed how variations in β-sheet organization influence optical properties of fibrils. We clarified the contribution of aromatic rings and the amyloid backbone to the final blue-green emission of fibrils. This work demonstrates how enantiomeric composition of amino acids allows us to modulate the self-assembly and final morphology of well-defined fibrillar bionanostructures with optical properties controlled by supramolecular organization.

Bessel beam optical tweezers for manipulating superparamagnetic beads

We propose a Bessel beam optical tweezers setup that can stably trap superparamagnetic beads. The trap stiffness measured is practically independent of the radius of the Bessel beam and of the bead height (distance from the coverlip of the sample chamber), indicating that the beads can be trapped with high accuracy within a wide range of such parameters. On the other hand, the trap stiffness exhibits the expected linear increase with the laser power, despite the non-negligible absorption coefficient of the superparamagnetic beads. A geometrical optics model that considers spherical aberration and light absorption by the beads was used to predict the optical forces and trap stiffness, showing excellent agreement with the experimental data. We believe the results presented here advance the field of optical trapping manipulation of absorbing magnetic particles, and future applications will involve, for example, the design of new hybrid optomagnetic tweezers.

Impact of COVID-19 on social media as perceived by the oncology community: results from a survey in collaboration with the European Society for Medical Oncology (ESMO) and the OncoAlert Network

Background

The COVID-19 pandemic has impacted all aspects of modern-day oncology, including how stakeholders communicate through social media. We surveyed oncology stakeholders in order to assess their attitudes pertaining to social media and how it has been affected during the pandemic.

Materials and methods

A 40-item survey was distributed to stakeholders from 8 July to 22 July 2020 and was promoted through the European Society for Medical Oncology (ESMO) and the OncoAlert Network.

Results

One thousand and seventy-six physicians and stakeholders took part in the survey. In total, 57.3% of respondents were medical oncologists, 50.6% aged <40 years, 50.8% of female gender and mostly practicing in Europe (51.5%). More than 90% of respondents considered social media a useful tool for distributing scientific information and for education. Most used social media to stay up to date on cancer care in general (62.5%) and cancer care during COVID-19 (61%) given the constant flow of information. Respondents also used social media to interact with other oncologists (78.8%) and with patients (34.4%). Overall, 61.1% of respondents were satisfied with the role that social media was playing during the COVID-19 pandemic. On the other hand, 41.1% of respondents reported trouble in discriminating between credible and less credible information and 30% stated social networks were a source of stress. For this reason, one-third of respondents reduced its use during the COVID-19 pandemic. Regarding meeting attendance, a total of 59.1% of responding physicians preferred in-person meetings to virtual ones, and 51.8% agreed that virtual meetings and social distancing could hamper effective collaboration.

Conclusion

Social media has a useful role in supporting cancer care and professional engagement in oncology. Although one-third of respondents reported reduced use of social media due to stress during the COVID-19 pandemic, the majority found social media useful to keep up to date and were satisfied with the role social media was playing during the pandemic.

•

More than 90% of the 1076 respondents believed in the role of social media promoting scientific information and education.

•

41% of respondents had trouble discriminating between credible and less credible information on social media.

•

61% of respondents used social media to stay up to date with scientific information regarding cancer care and COVID-19.

•

The flow of information on COVID-19 via social media was deemed useful for 49% of respondents but caused stress in 30%.

•

52% of respondents agreed that virtual meetings and social distancing could hamper effective collaboration.

Nanoscale Assembly of Functional Peptides with Divergent Programming Elements

Self-assembling peptides are being applied both in the biomedical area and as building blocks in nanotechnology. Their applications are closely linked to their modes of self-assembly, which determine the functional nanostructures that they form. This work brings together two structural elements that direct nanoscale self-association in divergent directions: proline as a β-breaker and the β-structure-associated diphenylalanine motif, into a single tripeptide sequence. Amino acid chirality was found to resolve the tension inherent to these conflicting self-assembly instructions. Stereoconfiguration determined the ability of each of the eight possible Pro-Phe-Phe stereoisomers to self-associate into diverse nanostructures, including nanoparticles, nanotapes, or fibrils, which yielded hydrogels with gel-to-sol transition at a physiologically relevant temperature. Three single-crystal structures and all-atom molecular dynamics simulations elucidated the ability of each peptide to establish key interactions to form long-range assemblies (i,e., stacks leading to gelling fibrils), medium-range assemblies (i.e., stacks yielding nanotapes), or short-range assemblies (i.e., dimers or trimers that further associated into nanoparticles). Importantly, diphenylalanine is known to serve as a binding site for pathological amyloids, potentially allowing these heterochiral systems to influence the fibrillization of other biologically relevant peptides. To probe this hypothesis, all eight Pro-Phe-Phe stereoisomers were tested in vitro on the Alzheimer's disease-associated Aβ(1-42) peptide. Indeed, one nonfibril-forming stereoisomer effectively inhibited Aβ fibrillization through multivalent binding between diphenylalanine motifs. This work thus defined heterochirality as a useful feature to strategically develop future therapeutics to interfere with pathological processes, with the additional value of resistance to protease-mediated degradation and biocompatibility.

Heterochiral tetrapeptide self-assembly into hydrogel biomaterials for hydrolase mimicry

Self-assembling short peptides have attracted great interest as enzyme mimics, especially if the catalytic activity resides solely in the supramolecular structure so that it can be switched on/off as needed by controlling assembly/disassembly. Among the various enzyme classes, hydrolases find wide application in biomaterials, and their mimetics often contain His residues, in addition to either divalent cations or other amino acids to mimic the catalytic site. This work reports two self-assembling tetrapeptides based on the Ser-His motif for catalysis and the Phe-Phe motif to drive amyloid structure formation. Both peptides form thermoreversible hydrogels in phosphate buffer at neutral pH that display a mild esterase-like activity, as demonstrated on the hydrolysis of 4-nitrophenyl acetate as a model substrate, although presence of Ser did not enhance catalytic activity. The systems are characterised by circular dichroism, transmission electron microscopy, oscillatory rheology and Thioflavin T fluorescence as an amyloid stain, to provide further insights that may assist the future design of improved supramolecular catalysts.

Self-Assembling, Ultrashort Peptide Gels as Antimicrobial Biomaterials

Supramolecular antimicrobial hydrogels based on peptides are attractive soft materials for the treatment of infections, considering their ease of preparation and benign fate in biological settings and in the environment. In particular, stimuli-responsive systems that can be assembled/disassembled ad hoc could offer the opportunity to switch on/off their bioactivity as needed. Besides, the shorter is the peptide, the lower its cost of production. However, a structure-to-function relationship is yet to be defined and reported activities are generally not yet competitive relative to traditional antibiotics. Inspiration for their design can be found in host defense peptides (HDPs), which can self-assemble to exert their function. This article reviews research developments in this emerging area, and it examines features, differences and similarities between antimicrobial and amyloid peptides to open the avenue towards the next generation of supramolecular antimicrobial peptides as innovative therapeutic materials.

Tripeptide Self-Assembly into Bioactive Hydrogels: Effects of Terminus Modification on Biocatalysis

Bioactive hydrogels based on the self-assembly of tripeptides have attracted great interest in recent years. In particular, the search is active for sequences that are able to mimic enzymes when they are self-organized in a nanostructured hydrogel, so as to provide a smart catalytic (bio)material whose activity can be switched on/off with assembly/disassembly. Within the diverse enzymes that have been targeted for mimicry, hydrolases find wide application in biomaterials, ranging from their use to convert prodrugs into active compounds to their ability to work in reverse and catalyze a plethora of reactions. We recently reported the minimalistic l-His-d-Phe-d-Phe for its ability to self-organize into thermoreversible and biocatalytic hydrogels for esterase mimicry. In this work, we analyze the effects of terminus modifications that mimic the inclusion of the tripeptide in a longer sequence. Therefore, three analogues, i.e., N-acetylated, C-amidated, or both, were synthesized, purified, characterized by several techniques, and probed for self-assembly, hydrogelation, and esterase-like biocatalysis. This work provides useful insights into how chemical modifications at the termini affect self-assembly into biocatalytic hydrogels, and these data may become useful for the future design of supramolecular catalysts for enhanced performance.

Heterochirality and Halogenation Control Phe-Phe Hierarchical Assembly

Diphenylalanine is an amyloidogenic building block that can form a versatile array of supramolecular materials. Its shortcomings, however, include the uncontrolled hierarchical assembly into microtubes of heterogeneous size distribution and well-known cytotoxicity. This study rationalized heterochirality as a successful strategy to address both of these pitfalls and it provided an unprotected heterochiral dipeptide that self-organized into a homogeneous and optically clear hydrogel with excellent ability to sustain fibroblast cell proliferation and viability. Substitution of one l-amino acid with its d-enantiomer preserved the ability of the dipeptide to self-organize into nanotubes, as shown by single-crystal XRD analysis, whereby the pattern of electrostatic and hydrogen bonding interactions of the backbone was unaltered. The effect of heterochirality was manifested in subtle changes in the positioning of the aromatic side chains, which resulted in weaker intermolecular interactions between nanotubes. As a result, d-Phe-l-Phe self-organized into homogeneous nanofibrils with a diameter of 4 nm, corresponding to two layers of peptides around a water channel, and yielded a transparent hydrogel. In contrast with homochiral Phe-Phe stereoisomer, it formed stable hydrogels thermoreversibly. d-Phe-l-Phe displayed no amyloid toxicity in cell cultures with fibroblast cells proliferating in high numbers and viability on this biomaterial, marking it as a preferred substrate over tissue-culture plastic. Halogenation also enabled the tailoring of d-Phe-l-Phe self-organization. Fluorination allowed analogous supramolecular packing as confirmed by XRD, thus nanotube formation, and gave intermediate levels of bundling. In contrast, iodination was the most effective strategy to augment the stability of the resulting hydrogel, although at the expense of optical transparency and biocompatibility. Interestingly, iodine presence hindered the supramolecular packing into nanotubes, resulting instead into amphipathic layers of stacked peptides without the occurrence of halogen bonding. By unravelling fine details to control these materials at the meso- and macro-scale, this study significantly advanced our understanding of these systems.

Self-Assembly of an Amino Acid Derivative into an Antimicrobial Hydrogel Biomaterial

N-(4-Nitrobenzoyl)-Phe self-assembled into a transparent supramolecular hydrogel, which displayed high fibroblast and keratinocyte cell viability. The compound showed a mild antimicrobial activity against E. coli both as a hydrogel and in solution. Single-crystal XRD data revealed packing details, including protonation of the C-terminus due to an apparent pK_a shift, as confirmed by pH titrations. MicroRaman analysis revealed almost identical features between the gel and crystal states, although more disorder in the former. The hydrogel is thermoreversible and disassembles within a range of temperatures that can be fine-tuned by experimental conditions, such as gelator concentration. At the minimum gelling concentration of 0.63 wt %, the hydrogel disassembles in a physiological temperature range of 39-42 °C, thus opening the way to its potential use as a biomaterial.

Microwave-Assisted Cyclization of Unprotected Dipeptides in Water to 2,5-Piperazinediones and Self-Assembly Study of Products­ and Reagents

Dipeptides and their cyclized 2,5-piperazinedione (or diketopiperazine, DKP) derivatives are attractive building blocks for supra­molecular hydrogels. The Phe-Phe, (p-nitro)-Phe-Phe, and Phe-Val dipeptides and their corresponding DKPs are studied for self-assembly in water. The DKPs were obtained in high yields by microwave-assisted cyclization­ of the dipeptides in water, demonstrating that use of their methyl ester derivatives as reported in the literature is not necessary for successful cyclization. Single-crystal XRD structures are reported for two DKPs as well as stable hydrogels at neutral pH.

Embedding and Positioning of Two FeII4 L4 Cages in Supramolecular Tripeptide Gels for Selective Chemical Segregation

An unreported d,l-tripeptide self-assembled into gels that embedded FeII4 L4 metal-organic cages to form materials that were characterized by TEM, EDX, Raman spectroscopy, rheometry, UV/Vis and NMR spectroscopy, and circular dichroism. The cage type and concentration modulated gel viscoelasticity, and thus the diffusion rate of molecular guests through the nanostructured matrix, as gauged by 19 F and 1 H NMR spectroscopy. When two different cages were added to spatially separated gel layers, the gel-cage composite material enabled the spatial segregation of a mixture of guests that diffused into the gel. Each cage selectively encapsulated its preferred guest during diffusion. We thus present a new strategy for using nested supramolecular interactions to enable the separation of small molecules.

Supramolecular Tripeptide Hydrogel Assembly with 5-Fluorouracil

In this work, we present Thioflavin T fluorescence, transmission electron microscopy (TEM), circular dichroism (CD), Fourier-transformed infrared (FT-IR), and oscillatory rheometry studies applied to an antineoplastic drug, 5-fluorouracil (5-FU), embedded in a heterochiral tripeptide hydrogel to obtain a drug delivery supramolecular system. The release of 5-fluorouracil was monitored over time by reverse-phase high-performance liquid chromatography (HPLC) and its interaction with the tripeptide assemblies was probed by all-atom molecular dynamics simulations.

A biocatalytic and thermoreversible hydrogel from a histidine-containing tripeptide

We report the first histidine-containing self-assembling tripeptide devoid of capping groups that forms a thermoreversible hydrogel under physiological conditions and catalyses hydrolysis of an ester, providing a minimalist building block for functional soft materials.

Elemental turnover rates and trophic discrimination in juvenile Lebranche mullet Mugil liza under experimental conditions

The aim of this study was to determine the isotopic-turnover rate (R_IT ) and trophic-discrimination factor (F_TD ) in muscle tissues of Lebranche mullet Mugil liza fed an experimental diet (δ¹³ C = -27·1‰; δ¹⁵ N = 1·0‰). Juvenile M. liza exhibited a relatively fast R_IT , with a half-life (t₅₀ ) of only 16 and 14 days for δ¹³ C and δ¹⁵ N respectively and a nearly complete isotopic turnover (t₉₅ ) of 68 and 60 days for δ¹³ C and δ¹⁵ N.

Assembly of a Tripeptide and Anti-Inflammatory Drugs into Supramolecular Hydrogels for Sustained Release

Supramolecular hydrogels offer interesting opportunities for co-assembly with drugs towards sustained release over time, which could be achieved given that the drug participates in the hydrogel nanostructure, and it is not simply physically entrapped within the gel matrix. dLeu-Phe-Phe is an attractive building block of biomaterials in light of the peptide's inherent biocompatibility and biodegradability. This study evaluates the assembly of the tripeptide in the presence of either of the anti-inflammatory drugs ketoprofen or naproxen at levels analogous to commercial gel formulations. Fourier-transformed infrared (FT-IR), circular dichroism, Thioflavin T fluorescence, transmission electron microscopy (TEM), and oscillatory rheometry are used. Drug release over time is monitored by means of reverse-phase high performance liquid chromatography, and shows different kinetics for the two drugs.

Enhancing cAMP Levels as Strategy for the Treatment of Neuropsychiatric Disorders

Phosphodiesterases (PDEs) have gained attention as potential pharmacological targets for neuropsychiatric diseases due to their ability to hydrolyze the second messengers, cGMP and/or cAMP. It is well-known the relationship between cAMP signaling and inflammation. Since neuroinflammation is considered to play an important role in the pathology of brain disorders, inhibition of PDEs highly expressed in brain has emerged as an innovative strategy for the treatment of these pathologies. PDE4, 7, 8 and 10 inhibitors are presented here as promising drug candidates to overcome the partial efficacy and adverse effects of the current therapy for neuropsychiatric illness such as depression, cognitive impairments or schizophrenia. Enhancing the intracellular concentration of cAMP underlies the effects of PDE inhibitors in the above mentioned disorders.

Impact of clinical training on supra-aortic duplex and transcranial doppler examination concordance

Sonographic tests are observer-dependent. With 1,527 consecutive patients, 22 trainees were assessed at baseline and after a hands-on 1:1 program, with a pre-examination median of 76 studies/trainee. We evaluated the required number of supervised examinations to reach a 0.80 kappa index (ki). Statistics included linear and exponential generalized estimating equation models. In the exponential model, 76 studies for carotid-duplex and >102 for vertebral-duplex and transcranial Doppler were needed for a 0.80 ki. "Relevant-categories" after-training ki was 0.80 in carotid-duplex and transcranial Doppler but 0.60 in vertebral-duplex. A fixed training does not guarantee a high ki. Measuring the acquired skills of every trainee would improve quality. © 2016 Wiley Periodicals, Inc. J Clin Ultrasound 44:571-579, 2016.

Occupational Exposure to Endocrine-Disrupting Chemicals and Birth Weight and Length of Gestation: A European Meta-Analysis

BACKGROUND

Women of reproductive age can be exposed to endocrine-disrupting chemicals (EDCs) at work, and exposure to EDCs in pregnancy may affect fetal growth.

OBJECTIVES

We assessed whether maternal occupational exposure to EDCs during pregnancy as classified by application of a job exposure matrix was associated with birth weight, term low birth weight (LBW), length of gestation, and preterm delivery.

METHODS

Using individual participant data from 133,957 mother-child pairs in 13 European cohorts spanning births from 1994 through 2011, we linked maternal job titles with exposure to 10 EDC groups as assessed through a job exposure matrix. For each group, we combined the two levels of exposure categories (possible and probable) and compared birth outcomes with the unexposed group (exposure unlikely). We performed meta-analyses of cohort-specific estimates.

RESULTS

Eleven percent of pregnant women were classified as exposed to EDCs at work during pregnancy, based on job title. Classification of exposure to one or more EDC group was associated with an increased risk of term LBW [odds ratio (OR) = 1.25; 95% CI: 1.04, 1.49], as were most specific EDC groups; this association was consistent across cohorts. Further, the risk increased with increasing number of EDC groups (OR = 2.11; 95% CI: 1.10, 4.06 for exposure to four or more EDC groups). There were few associations (p < 0.05) with the other outcomes; women holding job titles classified as exposed to bisphenol A or brominated flame retardants were at higher risk for longer length of gestation.

CONCLUSION

Results from our large population-based birth cohort design indicate that employment during pregnancy in occupations classified as possibly or probably exposed to EDCs was associated with an increased risk of term LBW. Citation: Birks L, Casas M, Garcia AM, Alexander J, Barros H, Bergström A, Bonde JP, Burdorf A, Costet N, Danileviciute A, Eggesbø M, Fernández MF, González-Galarzo MC, Gražulevičienė R, Hanke W, Jaddoe V, Kogevinas M, Kull I, Lertxundi A, Melaki V, Andersen AM, Olea N, Polanska K, Rusconi F, Santa-Marina L, Santos AC, Vrijkotte T, Zugna D, Nieuwenhuijsen M, Cordier S, Vrijheid M. 2016. Occupational exposure to endocrine-disrupting chemicals and birth weight and length of gestation: a European meta-analysis. Environ Health Perspect 124:1785-1793; http://dx.doi.org/10.1289/EHP208.

Trophic segregation of a fish assemblage along lateral depth gradients in a subtropical coastal lagoon revealed by stable isotope analyses

Stable isotopes were used to evaluate the hypothesis that fish assemblages occurring in shallow and deep areas of a large coastal lagoon are structured in partially segregated trophic modules with consumers showing contrasting reliance on benthic or pelagic food sources. The results revealed that fishes in deep areas were mainly dependent on particulate organic matter in the sediment (SOM), whereas emergent macrophytes were as important as SOM to fish consumers in shallow areas. Conceptual trophic diagrams depicting relationships among basal food sources and consumers in different regions of the lagoon highlighted the greater use of multiple basal food sources by more feeding mode functional guilds in shallow water compared with the use of predominantly benthic resources (SOM) in deep areas. The findings appear to corroborate the initial hypothesis and offer complementary perspectives in understanding the role of spatial ecology in structuring coastal ecosystem function and productivity.

Aspects of fish conservation in the upper Patos Lagoon basin

The Patos Lagoon basin is a large (201 626 km(2) ) and complex drainage system in southern Brazil. The lagoon is 250 km long and 60 km wide, covering an area of 10 360 km(2) . The exchange of water with the Atlantic Ocean occurs through a 0·8 km wide and 15 m deep inlet, fixed by 4 km long jetties, at the southernmost part of the Patos Lagoon. The estuarine area is restricted to its southern portion (10%), although the upper limit of saline waters migrates seasonally and year to year, influenced by the wind regime and river discharge. The known number of recorded limnetic fish species is 200, but this number is expected to increase. A higher endemism is observed in fish species occurring in upper tributaries. The basin suffers from the direct impact of almost 7 million inhabitants, concentrated in small to large cities, most with untreated domestic effluents. There are at least 16 non-native species recorded in natural habitats of the Patos Lagoon basin, about half of these being from other South American river basins. Concerning the fishery, although sport and commercial fisheries are widespread throughout the Patos Lagoon basin, the lagoon itself and the estuarine area are the main fishing areas. Landing statistics are not available on a regular basis or for the whole basin. The fishery in the northern Patos Lagoon captures 31 different species, nine of which are responsible for most of the commercial catches, but only three species are actually sustaining the artisanal fishery: the viola Loricariichthys anus: 455 kg per 10 000 m(2) gillnet per day, the mullet Mugil liza: 123 kg per 10 000 m(2) gillnet per day and the marine catfish Genidens barbus: 50 kg per 10 000 m(2) gillnet per day. A decline of the fish stocks can be attributed to inadequate fishery surveillance, which leads to overfishing and mortality of juveniles, or to decreasing water quality because of urban and industrial activities and power production. Global climatic changes also represent a major threat to the Patos system by changing the frequency of El Niño-La Niña-Southern Oscillation (ENSO).

Fish composition and species richness in eastern South American coastal lagoons: additional support for the freshwater ecoregions of the world

The relationships between fish composition, connectivity and morphometry of 103 lagoons in nine freshwater ecoregions (FEOW) between 2·83° S and 37·64° S were evaluated in order to detect possible congruence between the gradient of species richness and similarities of assemblage composition. Most lagoons included in the study were <2 km(2) , with a maximum of 3975 km(2) in surface area. Combined surface area of all lagoons included in the study was 5411 km(2) . Number of species varied locally from one to 76. A multiple regression revealed that latitude, attributes of morphometry and connectivity, and sampling effort explained a large amount of variability in species richness. Lagoon area was a good predictor of species richness except in low latitude ecoregions, where lagoons are typically small-sized and not affected by marine immigrants, and where non-native fish species accounted for a significant portion of species richness. Relationships between species and area in small-sized lagoons (<2 km(2) ) is highly similar to the expected number in each ecoregion, with systems located between 18·27° S and 30·15° S attaining higher levels of species richness. Similarities in species composition within the primary, secondary and peripheral or marine divisions revealed strong continental biogeographic patterns only for species less tolerant or intolerant to salinity. Further support for the FEOW scheme in the eastern border of South America is therefore provided, and now includes ecotonal systems inhabited simultaneously by freshwater and marine species of fishes.

Gene expression during activation of Paracoccidioides brasiliensis conidia

This study focuses on gene expression during crucial biological phenomena of the dimorphic fungal human pathogen Paracoccidioides brasiliensis, the conidia-to-yeast (C-Y) transition and the conidia-to-mycelia (C-M) germination. We studied 10 genes involved in different cellular functions: oxidative stress response (alternative oxidase (AOX), superoxide dismutase (SOD), flavodoxin, conserved hypothetical protein (Y20)); cell metabolism (glyceraldehyde-3-phosphate dehydrogenase (GADPH), cholestenol Delta-isomerase (ChDI), glycine dehydrogenase (GDh)) and heat shock response (Heat shock protein 90 (HSP90)), and cell synthesis and wall structure (glucan synthase-1 (GS-1), α-1,3-glucan synthase (αGS), and mannosyltransferase (MT)). Gene expression was measured during the first 72 h and 96 h of C-Y and C-M, respectively, previously shown to be a fundamental time frame for the consolidation of these cellular processes. The gene expression of AOX, GAPDH, HSP90, MT, αGS, and GDh was significantly increased during the C-Y transition, while SOD, ChDI, GAPDH, MT, GDh, and GS-1 were increased during C-M germination. Additionally, some were highly expressed in each process: AOX, HSP90, and αGS during C-Y; SOD, ChDI, and GS-1 during C-M. Altogether, these data add new information regarding gene expression during the C-Y and C-M processes. Future research will be targeted to further characterize the true relevance of the studied genes during the morphological transition, either during adaptation to the environment or to the infected host.

Abstract 627: Etp-47187 a novel potent and efficacious dual inhibitor of phosphoinositide-3-kinases and mTOR

The phosphoinositide-3-kinase (PI3K) signaling pathway is activated in a variety of solid and non-solid tumors. In many instances this is due to either activating mutations in the catalytic subunit of PI3Kα, p110α, or inactivating mutations or deletions of the tumor suppressor PTEN. In addition, the PI3K pathway is activated by mutations in certain receptor tyrosine kinases as well as by mutation of the oncogene KRAS. All of these lesions lead to enhanced activity of both PI3K and mTOR. Hence there is great interest to discover inhibitors of PI3K and mTOR for the treatment for cancer. Following a rational design strategy, we identified the fused thiadiazole derivative ETP-47187 as a potent dual inhibitor of PI3Kα and mTOR Kis = 0.18 nM and 1.2 nM, respectively. ETP-47187 also inhibits three oncogenc mutants of p110α: p110α E542K Ki = 0.38 nM, p110α E545K Ki = 0.2 nM and p110α H1047R Ki = 0.29 nM as well as PI3Kβ, PI3KΔ and PI3Kγ Kis 2.7, 0.26 and 1.5 nM, respectively. The compound inhibits PI3K signaling in treated tumor cell lines; the EC50 for inhibition of the phosphorylation of Akt was 5 nM. ETP-47187 has a pharmacokinetic profile suitable for oral dosing in mice (%F = 73%, Cl = 0.11 L/hr/kg; Vds = 0.38 L/h/kg). Treatment of tumor bearing mice with the compound causes a dose dependent reduction in P-Akt levels in the tumor. Once a day treatment of mice bearing human tumor xenografts with ETP-47187 results in significant tumor growth delay and is well tolerated. In a mouse model of lung cancer induced by expression of an oncogenic mutant KRAS, treatment with ETP-47187 blocked tumor growth and lead to a significant PET response. These and combination data will be discussed. We believe ETP-47187 and compounds like it are suitable to propose for clinical development in cancer patients with activated PI3K signaling.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 627. doi:10.1158/1538-7445.AM2011-627

Radiopacity of zirconia-based all-ceramic crown systems

The aim of this study was to evaluate the radiopacity of the core and veneer ceramics in four zirconia-based crown systems: In-Ceram Zirconia, In-Ceram YZ, Procera Zirconia, and Cercon. Two-millimeter-thick restoration slices were prepared and digitally radiographed alongside an aluminum stepwedge. The grayscale data were converted into millimeters of aluminum by an image analysis program. The two-way analysis of variance test detected significant differences with respect to all-ceramic system, layer ceramic, and the interaction of the two factors (P = .0001). All materials presented radiopacity values above the minimum recommended by the International Organization for Standardization.

Individual and occupational factors related to fatal occupational injuries: a case-control study

This study has been designed in order to identify factors increasing the risk of a fatal outcome when occupational accidents occur. The aim is to provide further evidence for the design and implementation of preventive measures in occupational settings. The Spanish Ministry of Labour registry of occupational injuries causing absence from work includes information on individual and occupational characteristics of injured workers and events. Registered fatal occupational injuries in 2001 (n=539) were compared to a sample of non-fatal injuries in the same year (n=3493). Risks for a fatal result of occupational injuries, adjusted by individual and occupational factors significantly associated, were obtained through logistic regression models. Compared to non-fatal injuries, fatal occupational injuries were mostly produced by trapping or by natural causes, mostly related to elevation and transport devices and power generators, and injured parts of body more frequently affected were head, multiple parts or internal organs. Adjusted analyses showed increased risk of fatality after an occupational injury for males (adjusted odds ratio aOR=10.92; 95%CI 4.80-24.84) and temporary workers (aOR=5.18; 95%CI 2.63-10.18), and the risk increased with age and with advancing hour of the work shift (p for trends <0.01). Injuries taking place out of the usual occupational setting (aOR=2.85, 95%CI 2.27-3.59), or carrying out atypical tasks (aOR=2.08; 95%CI 1.27-3.39) showed increased risks of a fatal result too, as occupational accidents in agricultural or construction companies. These data can help to select and define priorities for programmes aimed to prevent fatal consequences of occupational injuries.

Production of citreoviridin by Penicillium citreonigrum strains associated with rice consumption and beriberi cases in the Maranhão State, Brazil

The aim of this study was to determine the levels of Penicillium citreonigrum and citreoviridin present in rice samples from Maranhão State, Brazil, where an outbreak of beriberi was reported and 32 deaths occurred (7% of the notified cases died in 2006). The ability of P. citreonigrum to produce citreoviridin was assessed, and a total of 420 samples of 21 different kinds of rice were collected. Mycobiota isolation and identification, the ability of citreoviridin strains to produce toxin, and the natural occurrence of citreoviridin were established. Rice samples were found to have high fungal counts and showed increasing levels from 2004 to 2007 harvest years. The most frequent genus was Aspergillus followed by Penicillium and Cladosporium. Ten out of eleven strains of P. citreonigrum were able to produce citreoviridin. Three rice samples had levels of citreoviridin ranging from 12 to 96.7 ng g(-1), and two bran samples had levels of 128 and 254 ng g(-1). These samples contaminated with P. citreonigrum and citreoviridin were involved in the beriberi cases from Maranhão State. Monitoring rice for mycotoxins in areas where this substrate is the basic food is crucial to prevent outbreaks like the one reported in this study, to improve management practice, and to diminish exposure risk of humans to these harmful toxins.

Mother tongue lost while second language intact: insights into aphasia

Cortical representations of the native language and a second language may have different anatomical distribution. The relationships between the phonologic and orthographic forms of words continue to be debated. We present a bilingual patient whose competence in his mother tongue was disrupted following brain ischaemia. Semantic units were accessible only as isolated letters in written as well as oral language presentation. His second language appeared completely unaffected. Whole word system disturbance of both orthography and phonology pathways of the native language could explain this presentation. It is a great opportunity to learn about the language neural network when a bilingual subject presents with brain ischaemia.

Thrombolysis for ischaemic stroke and glioblastoma multiforme: a case report

OBJECTIVE

To report the uncomplicated use of systemic thrombolysis for stroke in a patient with a misdiagnosed glioblastoma multiforme mimicking brain ischaemia and to suggest that new clinical situations question the stated exclusion criteria for intravenous thrombolysis.

PATIENT

A 57-year-old male presented at the emergency room with a sudden aphasia.

MEASUREMENT AND MAIN RESULTS

After Safe Implementation of Thrombolysis in Stroke-Monitoring Study (SITS-MOST) exclusion criteria were ruled out, intravenous alteplase was administered. The patient presented with tonic-clonic seizures 17 min after perfusion completion, requiring phenytoine administration. Additional computed tomography scan did not show haemorrhagic transformation or brain oedema. A left temporal lobe glioblastoma multiforme was diagnosed after magnetic resonance imaging and neurosurgery. The patient became asymptomatic on the seventh day.

CONCLUSION

Any history of central nervous system neoplasm is considered a contraindication to thrombolysis, but the true risk of systemic thrombolysis-precipitated intracranial bleeding is unknown. Further data are needed to establish real haemorrhage risk in this clinical condition.

Organ-injury-induced reactivation of hemangioblastic precursor cells

Early in mammalian development, the stem cell leukemia (SCL/TAL1) gene and its distinct 3' enhancer (SCL 3'En) specify bipotential progenitor cells that give rise to blood and endothelium, thus termed hemangioblasts. We have previously detected a minor population of SCL (+) cells in the postnatal kidney. Here, we demonstrate that cells expressing the SCL 3'En in the adult kidney are comprised of CD45+CD31- hematopoietic cells, CD45-CD31+ endothelial cells and CD45-CD31- interstitial cells. Creation of bone marrow chimeras of SCL 3'En transgenic mice into wild-type hosts shows that all three types of SCL 3'En-expressing cells in the adult kidney can originate from the bone marrow. Ischemia/reperfusion injury to the adult kidney of SCL 3'En transgenic mice results in the intrarenal elevation of SCL and FLK1 mRNA levels and of cells expressing hem-endothelial progenitor markers (CD45, CD34, c-Kit and FLK1). Furthermore, analysis of SCL 3'En in the ischemic kidneys reveals an increase in the abundance of SCL 3'En-expressing cells, predominantly within the CD45 (+) hematopoietic fraction and to a lesser extent in the CD45 (-) fraction. Our results suggest organ-injury-induced reactivation of bone marrow-derived hemangioblasts and possible local angioblastic progenitors expressing SCL and SCL 3'En.

Antimicrobial and general toxicity activities of Gymnosperma glutinosum: a comparative study

Gymnosperma glutinosum (Spreng.) Less (Asteraceae) is an important, and an effective herbal medicine which is wide used for the treatment of diarrhoea in Mexico. We examined and compared the antibacterial and antifungal activities through the dilution method and for general toxicity activity by the brine shrimp lethality assay of two samples of Gymnosperma glutinosum from two localities of Mexico: San Rafael-Coxcatlan (Puebla State) and Tepeji del Rio (Hidalgo State). In addition, two bioactive compounds (-)-17-hydroxy-neo-clerod-3-en-15-oic acid (1) and 5,7-dihydroxy-3,6,8,2',4',5'-hexamethoxyflavone (2) were isolated. From the hexane extract from both places was obtained a MeOH partition M(2). M(2) of Tepeji del Rio showed the least MICs (<125 microg/ml) in the majority of the bacterial strains. Sarcina lutea was the most sensitive bacteria (MIC< 125 microg/ml). The hexane extract of both localities showed antifungal activity against all tested fungi. San Rafael's hexane extract was significant more activity than Tepeji del Rio. Aspergillus niger (IC(50)=23.79 microg/ml) and Trichophyton mentagrophytes (IC(50)=90.25 microg/ml) were the more sensitive fungus strains. The strongest general toxicity activity was observed with the M(2) partition from Tepeji del Rio (LC(50)=503.7 microg/ml). The results obtained in this investigation, showed differences between the antimicrobial activities of the samples of plants collected in San Rafael (Puebla) and Tepeji del Rio (Hidalgo).