Seabirds boost coral reef resilience

Global climate change threatens tropical coral reefs, yet local management can influence resilience. While increasing anthropogenic nutrients reduce coral resistance and recovery, it is unknown how the loss, or restoration, of natural nutrient flows affects reef recovery. Here, we test how natural seabird-derived nutrient subsidies, which are threatened by invasive rats, influence the mechanisms and patterns of reef recovery following an extreme marine heatwave using multiyear field experiments, repeated surveys, and Bayesian modeling. Corals transplanted from rat to seabird islands quickly assimilated seabird-derived nutrients, fully acclimating to new nutrient conditions within 3 years. Increased seabird-derived nutrients, in turn, caused a doubling of coral growth rates both within individuals and across entire reefs. Seabirds were also associated with faster recovery time of Acropora coral cover (<4 years) and more dynamic recovery trajectories of entire benthic communities. We conclude that restoring seabird populations and associated nutrient pathways may foster greater coral reef resilience through enhanced growth and recovery rates of corals.

Artificial light at night (ALAN) disrupts behavioural patterns of reef corals

Increasing levels of Artificial Light At Night (ALAN) alter the natural diel cycles of organisms at global scale. ALAN constitutes a potential threat to the light-dependent functioning of symbiotic scleractinian corals, the habit-founders of warm, shallow water reefs. Here, we show that ALAN disrupts the natural diel tentacle expansion and contraction behaviour, a key mechanism for prey capture and nutrient acquisition in corals. We exposed four symbiotic scleractinian coral species to different ALAN treatments (0.4-2.5 μmol quanta m-2 s-1). Exposure to ALAN levels of 1.2 μmol quanta m-2 s-1 and above altered the normal tentacle expansion response in diurnal species (Stylophora pistillata and Duncanopsammia axifuga). The tentacle expansion pattern of nocturnal species (Montastraea cavernosa and Lobophyllia hemprichii) was less affected, which may indicate a greater capacity to tolerate ALAN exposure. The results of this work suggest that ALAN has the potential to affect nutrient acquisition mechanisms of symbiotic corals which may in turn result in changes in the coral community structure in shallow water reefs in ALAN-exposed areas.

CryoEM analysis of the essential native UDP-glucose pyrophosphorylase from Aspergillus nidulans reveals key conformations for activity regulation and function

Invasive aspergillosis is one of the most serious clinical invasive fungal infections, resulting in a high case fatality rate among immunocompromised patients. The disease is caused by saprophytic molds in the genus Aspergillus, including Aspergillus fumigatus, the most significant pathogenic species. The fungal cell wall, an essential structure mainly composed of glucan, chitin, galactomannan, and galactosaminogalactan, represents an important target for the development of antifungal drugs. UDP (uridine diphosphate)-glucose pyrophosphorylase (UGP) is a central enzyme in the metabolism of carbohydrates that catalyzes the biosynthesis of UDP-glucose, a key precursor of fungal cell wall polysaccharides. Here, we demonstrate that the function of UGP is vital for Aspergillus nidulans (AnUGP). To understand the molecular basis of AnUGP function, we describe a cryoEM structure (global resolution of 3.5 Å for the locally refined subunit and 4 Å for the octameric complex) of a native AnUGP. The structure reveals an octameric architecture with each subunit comprising an N-terminal α-helical domain, a central catalytic glycosyltransferase A-like (GT-A-like) domain, and a C-terminal (CT) left-handed β-helix oligomerization domain. AnUGP displays unprecedented conformational variability between the CT oligomerization domain and the central GT-A-like catalytic domain. In combination with activity measurements and bioinformatics analysis, we unveil the molecular mechanism of substrate recognition and specificity for AnUGP. Altogether, our study not only contributes to understanding the molecular mechanism of catalysis/regulation of an important class of enzymes but also provides the genetic, biochemical, and structural groundwork for the future exploitation of UGP as a potential antifungal target. IMPORTANCE Fungi cause diverse diseases in humans, ranging from allergic syndromes to life-threatening invasive diseases, together affecting more than a billion people worldwide. Increasing drug resistance in Aspergillus species represents an emerging global health threat, making the design of antifungals with novel mechanisms of action a worldwide priority. The cryoEM structure of UDP (uridine diphosphate)-glucose pyrophosphorylase (UGP) from the filamentous fungus Aspergillus nidulans reveals an octameric architecture displaying unprecedented conformational variability between the C-terminal oligomerization domain and the central glycosyltransferase A-like catalytic domain in the individual protomers. While the active site and oligomerization interfaces are more highly conserved, these dynamic interfaces include motifs restricted to specific clades of filamentous fungi. Functional study of these motifs could lead to the definition of new targets for antifungals inhibiting UGP activity and, thus, the architecture of the cell wall of filamentous fungal pathogens.

Reef-building corals farm and feed on their photosynthetic symbionts

Coral reefs are highly diverse ecosystems that thrive in nutrient-poor waters, a phenomenon frequently referred to as the Darwin paradox1. The energy demand of coral animal hosts can often be fully met by the excess production of carbon-rich photosynthates by their algal symbionts2,3. However, the understanding of mechanisms that enable corals to acquire the vital nutrients nitrogen and phosphorus from their symbionts is incomplete4-9. Here we show, through a series of long-term experiments, that the uptake of dissolved inorganic nitrogen and phosphorus by the symbionts alone is sufficient to sustain rapid coral growth. Next, considering the nitrogen and phosphorus budgets of host and symbionts, we identify that these nutrients are gathered through symbiont 'farming' and are translocated to the host by digestion of excess symbiont cells. Finally, we use a large-scale natural experiment in which seabirds fertilize some reefs but not others, to show that the efficient utilization of dissolved inorganic nutrients by symbiotic corals established in our laboratory experiments has the potential to enhance coral growth in the wild at the ecosystem level. Feeding on symbionts enables coral animals to tap into an important nutrient pool and helps to explain the evolutionary and ecological success of symbiotic corals in nutrient-limited waters.

A multi-enzyme machine polymerizes the Haemophilus influenzae type b capsule

Bacterial capsules have critical roles in host-pathogen interactions. They provide a protective envelope against host recognition, leading to immune evasion and bacterial survival. Here we define the capsule biosynthesis pathway of Haemophilus influenzae serotype b (Hib), a Gram-negative bacterium that causes severe infections in infants and children. Reconstitution of this pathway enabled the fermentation-free production of Hib vaccine antigens starting from widely available precursors and detailed characterization of the enzymatic machinery. The X-ray crystal structure of the capsule polymerase Bcs3 reveals a multi-enzyme machine adopting a basket-like shape that creates a protected environment for the synthesis of the complex Hib polymer. This architecture is commonly exploited for surface glycan synthesis by both Gram-negative and Gram-positive pathogens. Supported by biochemical studies and comprehensive 2D nuclear magnetic resonance, our data explain how the ribofuranosyltransferase CriT, the phosphatase CrpP, the ribitol-phosphate transferase CroT and a polymer-binding domain function as a unique multi-enzyme assembly.

Global disruption of coral broadcast spawning associated with artificial light at night

Coral broadcast spawning events - in which gametes are released on certain nights predictably in relation to lunar cycles - are critical to the maintenance and recovery of coral reefs following mass mortality. Artificial light at night (ALAN) from coastal and offshore developments threatens coral reef health by masking natural light:dark cycles that synchronize broadcast spawning. Using a recently published atlas of underwater light pollution, we analyze a global dataset of 2135 spawning observations from the 21^st century. For the majority of genera, corals exposed to light pollution are spawning between one and three days closer to the full moon compared to those on unlit reefs. ALAN possibly advances the trigger for spawning by creating a perceived period of minimum illuminance between sunset and moonrise on nights following the full moon. Advancing the timing of mass spawning could decrease the probability of gamete fertilization and survival, with clear implications for ecological processes involved in the resilience of reef systems.

PARP1 allows proper telomere replication through TRF1 poly (ADP-ribosyl)ation and helicase recruitment

Telomeres are nucleoprotein structures at eukaryotic chromosome termini. Their stability is preserved by a six-protein complex named shelterin. Among these, TRF1 binds telomere duplex and assists DNA replication with mechanisms only partly clarified. Here we found that poly (ADP-ribose) polymerase 1 (PARP1) interacts and covalently PARylates TRF1 in S-phase modifying its DNA affinity. Therefore, genetic and pharmacological inhibition of PARP1 impairs the dynamic association of TRF1 and the bromodeoxyuridine incorporation at replicating telomeres. Inhibition of PARP1 also affects the recruitment of WRN and BLM helicases in TRF1 containing complexes during S-phase, triggering replication-dependent DNA-damage and telomere fragility. This work unveils an unprecedented role for PARP1 as a "surveillant" of telomere replication, which orchestrates protein dynamics at proceeding replication fork.

Green fluorescent protein-like pigments optimize the internal light environment in symbiotic reef building corals

Pigments homologous to the green fluorescent protein (GFP) have been proposed to fine-tune the internal light microclimate of corals, facilitating photoacclimation of photosynthetic coral symbionts (Symbiodiniaceae) to life in different reef habitats and environmental conditions. However, direct measurements of the in vivo light conditions inside the coral tissue supporting this conclusion are lacking. Here, we quantified the intra-tissue spectral light environment of corals expressing GFP-like proteins from widely different light regimes. We focus on: (1) photoconvertible red fluorescent proteins (pcRFPs), thought to enhance photosynthesis in mesophotic habitats via wavelength conversion, and (2) chromoproteins (CPs), which provide photoprotection to the symbionts in shallow water via light absorption. Optical microsensor measurements indicated that both pigment groups strongly alter the coral intra-tissue light environment. Estimates derived from light spectra measured in pcRFP-containing corals showed that fluorescence emission can contribute to >50% of orange-red light available to the photosynthetic symbionts at mesophotic depths. We further show that upregulation of pink CPs in shallow-water corals during bleaching leads to a reduction of orange light by 10–20% compared to low-CP tissue. Thus, screening by CPs has an important role in mitigating the light-enhancing effect of coral tissue scattering and skeletal reflection during bleaching. Our results provide the first experimental quantification of the importance of GFP-like proteins in fine-tuning the light microclimate of corals during photoacclimation.

Timing of ejection fraction reassessment after sacubitril-valsartan initiation for indication to defibrillator implantation. A single center experience

Background

Sacubitril/Valsartan (SV) has recently been validated in the therapy of heart failure (HF) with reduced ejection fraction (EF). SV is effective on symptoms and heart remodeling. At the moment the best timing to EF assessment after SV initiation in order to proceed with defibrillator (ICD) implantation, it's unknown.

Purpose

Evaluate the timing of improvement of EF after SV initiation in patients (pts) with systolic HF, candidates to primary prevention ICD implantation.

Methods

We enrolled all consecutive pts candidates to primary prevention ICD implantation that underwent SV initiation from February 2018. We evaluated clinical and echo follow up (Fup). Results have been analyzed with paired T-test).

Results

The study involved 61 pts (mean age 67±10 years, 71% male, ischemic cardiopathy 44%, mean time from diagnosis 31 months) with mean EF at enrollment 30±5% (ED vol 94 ml/m2, ES vol 64 ml/m2, severe MR 21%) and mean NYHA 3±0.6. After a mean Fup of 6 months mean EF increased to 37±7% (ED vol 80 ml/m2, ES vol 51 ml/m2, severe MR 8%, p&lt;0.004), NYHA decreased to 2±0.6 (p&lt;0.04). In 69% pts SV dosage reached 97/103 mg bid. 28 pts (45%) had first Fup at 3 months and showed already mean EF 34±6% and mean NYHA 1.6±0.6 (p&lt;0.04). 26 pts (43%) had last Fup echo after 1 year (mean 17±10 months) and showed further EF little improvement (38.3±8%, p 0.05).

Conclusions

After SV initiation in systolic HF, heart remodeling is already evident at 3 months Fup and better appreciable at 6 months Fup. Little non significant further EF improvement could be seen later. In our study best timing to decide for primary prevention ICD is likely between 3 and 6 months after SV initiation.

Funding Acknowledgement

Type of funding sources: None. Figure 1

Pentadecanoic acid against Candida albicans-Klebsiella pneumoniae biofilm: towards the development of an anti-biofilm coating to prevent polymicrobial infections

The ability to form biofilms is a common feature of microorganisms, which can colonize a variety of surfaces, such as host tissues and medical devices, resulting in infections highly resistant to conventional drugs. This aspect is particularly critical in polymicrobial biofilms involving both fungi and bacteria, therefore, to eradicate such severe infections, new and effective anti-biofilm strategies are needed. The efficacy of pentadecanal and pentadecanoic acid as anti-biofilm agents has been recently reported against different bacterial strains. Their chemical similarity with diffusible signal factors (DSFs), plus the already known ability of fatty acids to act as anti-biofilm agents, suggested to explore their use against Candida albicans and Klebsiella pneumoniae mixed biofilm. In this work, we demonstrated the ability of both molecules to prevent the formation and destabilize the structure of the dual-species biofilm. Moreover, the pentadecanoic acid anti-biofilm coating, previously developed through the adsorption of the fatty acid on polydimethylsiloxane (PDMS), was proved to prevent the polymicrobial biofilm formation in dynamic conditions by confocal laser scanning microscopy analysis. Finally, the evaluation of the expression levels of some biofilm-related genes of C. albicans and K. pneumoniae treated with pentadecanoic acid provided some insights into the molecular mechanisms underpinning its anti-biofilm effect.

Dissecting the Structural and Chemical Determinants of the "Open-to-Closed" Motion in the Mannosyltransferase PimA from Mycobacteria

The phosphatidyl-myo-inositol mannosyltransferase A (PimA) is an essential peripheral membrane glycosyltransferase that initiates the biosynthetic pathway of phosphatidyl-myo-inositol mannosides (PIMs), key structural elements and virulence factors of Mycobacterium tuberculosis. PimA undergoes functionally important conformational changes, including (i) α-helix-to-β-strand and β-strand-to-α-helix transitions and (ii) an "open-to-closed" motion between the two Rossmann-fold domains, a conformational change that is necessary to generate a catalytically competent active site. In previous work, we established that GDP-Man and GDP stabilize the enzyme and facilitate the switch to a more compact active state. To determine the structural contribution of the mannose ring in such an activation mechanism, we analyzed a series of chemical derivatives, including mannose phosphate (Man-P) and mannose pyrophosphate-ribose (Man-PP-RIB), and additional GDP derivatives, such as pyrophosphate ribose (PP-RIB) and GMP, by the combined use of X-ray crystallography, limited proteolysis, circular dichroism, isothermal titration calorimetry, and small angle X-ray scattering methods. Although the β-phosphate is present, we found that the mannose ring, covalently attached to neither phosphate (Man-P) nor PP-RIB (Man-PP-RIB), does promote the switch to the active compact form of the enzyme. Therefore, the nucleotide moiety of GDP-Man, and not the sugar ring, facilitates the "open-to-closed" motion, with the β-phosphate group providing the high-affinity binding to PimA. Altogether, the experimental data contribute to a better understanding of the structural determinants involved in the "open-to-closed" motion not only observed in PimA but also visualized and/or predicted in other glycosyltransfeases. In addition, the experimental data might prove to be useful for the discovery and/or development of PimA and/or glycosyltransferase inhibitors.

Exploratory study on immune phenotypes in Alzheimer's disease and vascular dementia

BACKGROUND AND PURPOSE

The differentiation of Alzheimer's disease (AD) dementia from vascular dementia (VaD) and mixed-type dementia (mixed dementia) requires stepwise analysis and usually occurs late in the disease process. Early diagnosis and therapy monitoring would benefit greatly from the identification of biomarkers of neurodegeneration, especially blood biomarkers. To this end, the aim of the present pilot study was to investigate differences in the distribution of peripheral T-cell populations in patients with AD compared to VaD and mixed dementia.

METHODS

Flow cytometry was performed on blood samples from 11 patients with AD, six with VaD and six with mixed dementia, as well as 17 healthy control subjects (HCs). CD4+ and CD8+ T cells were typed for expression of CD45, CD27, CD28, CD25, FoxP3, CCR4 and CCR6; the other leukocytes were also assessed. Functionally, immune cell uptake of the β-amyloid (Aβ) toxic fragment (Aβ_1-42 ) was also evaluated.

RESULTS

A higher proportion of CD4+CD28- memory T cells and a reciprocal reduction of CD4+CD28+CD27+ naïve T lymphocytes was detected in all patient groups relative to controls. Significantly fewer CD4+CD25+FoxP3 regulatory T cells were present in patients with VaD, and significantly more CCR6+ and CCR4+ CD4+ T cells in those with AD. Higher CCR6+ T-cell frequencies were also present in patients with mixed dementia, potentially due to the inflammation and immune cell chemoattraction triggered by Aβ.

CONCLUSIONS

The present study was a comprehensive investigation comparing different kinds of dementia, revealing differentially expressed peripheral markers that are potentially useful for early AD, VaD and mixed dementia diagnoses, and that would assist in proper treatments for these disparate diseases. Validation is now required.

Optical Feedback Loop Involving Dinoflagellate Symbiont and Scleractinian Host Drives Colorful Coral Bleaching

Coral bleaching, caused by the loss of brownish-colored dinoflagellate photosymbionts from the host tissue of reef-building corals, is a major threat to reef survival. Occasionally, bleached corals become exceptionally colorful rather than white. These colors derive from photoprotective green fluorescent protein (GFP)-like pigments produced by the coral host. There is currently no consensus regarding what causes colorful bleaching events and what the consequences for the corals are. Here, we document that colorful bleaching events are a recurring phenomenon in reef regions around the globe. Our analysis of temperature conditions associated with colorful bleaching events suggests that corals develop extreme coloration within 2 to 3 weeks after exposure to mild or temporary heat stress. We demonstrate that the increase of light fluxes in symbiont-depleted tissue promoted by reflection of the incident light from the coral skeleton induces strong expression of the photoprotective coral host pigments. We describe an optical feedback loop involving both partners of the association, discussing that the mitigation of light stress offered by host pigments could facilitate recolonization of bleached tissue by symbionts. Our data indicate that colorful bleaching has the potential to identify local environmental factors, such as nutrient stress, that can exacerbate the impact of elevated temperatures on corals, to indicate the severity of heat stress experienced by corals and to gauge their post-stress recovery potential. VIDEO ABSTRACT.

The allosteric control mechanism of bacterial glycogen biosynthesis disclosed by cryoEM

Glycogen and starch are the major carbon and energy reserve polysaccharides in nature, providing living organisms with a survival advantage. The evolution of the enzymatic machinery responsible for the biosynthesis and degradation of such polysaccharides, led the development of mechanisms to control the assembly and disassembly rate, to store and recover glucose according to cell energy demands. The tetrameric enzyme ADP-glucose pyrophosphorylase (AGPase) catalyzes and regulates the initial step in the biosynthesis of both α-polyglucans. AGPase displays cooperativity and allosteric regulation by sensing metabolites from the cell energy flux. The understanding of the allosteric signal transduction mechanisms in AGPase arises as a long-standing challenge. In this work, we disclose the cryoEM structures of the paradigmatic homotetrameric AGPase from Escherichia coli (EcAGPase), in complex with either positive or negative physiological allosteric regulators, fructose-1,6-bisphosphate (FBP) and AMP respectively, both at 3.0 Å resolution. Strikingly, the structures reveal that FBP binds deeply into the allosteric cleft and overlaps the AMP site. As a consequence, FBP promotes a concerted conformational switch of a regulatory loop, RL2, from a "locked" to a "free" state, modulating ATP binding and activating the enzyme. This notion is strongly supported by our complementary biophysical and bioinformatics evidence, and a careful analysis of vast enzyme kinetics data on single-point mutants of EcAGPase. The cryoEM structures uncover the residue interaction networks (RIN) between the allosteric and the catalytic components of the enzyme, providing unique details on how the signaling information is transmitted across the tetramer, from which cooperativity emerges. Altogether, the conformational states visualized by cryoEM reveal the regulatory mechanism of EcAGPase, laying the foundations to understand the allosteric control of bacterial glycogen biosynthesis at the molecular level of detail.

Circulating CD40 ligand, Dickkopf-1 and P-selectin in HIV-infected patients

OBJECTIVES

The aim of this study was to evaluate the circulating levels of CD40 ligand (CD40 L), Dickkopf-1 (DKK-1) and P-selectin, their relationships and their contributions to cardiovascular risk in subjects with HIV infection.

METHODS

The study population included 80 HIV-infected patients, 14 (17.5%) of whom had diabetes mellitus (DM) and 32 (40.0%) of whom had arterial hypertension (AH). The HIV-infected patients were compared with a control group with similar demographic and clinical features. CD40L, DKK-1 and P-selectin levels were measured using an enzyme-linked immunosorbent assay.

RESULTS

The HIV-infected patients showed higher levels of all the cardiovascular disease (CVD) markers. Both serum CD40L and DKK-1 were significantly higher in HIV-infected patients than in the HIV-negative controls (P < 0.001), while soluble P-selectin showed no significant between-group difference (P = 0.133), reflecting the role of HIV infection in CVD. In the HIV-infected group, patients with DM showed lower levels of CD40L and DKK-1 in comparison with the nondiabetic patients and patients with AH (P < 0.05, with Bonferroni correction). In contrast, patients with AH showed higher levels of CD40L and DKK-1 in comparison to patients without DM or AH (P < 0.05, with Bonferroni correction). Patients with AH showed higher levels of CD40L and DKK-1 than patients with DM (P < 0.05, with Bonferroni correction).

CONCLUSIONS

In this study, we found that HIV-infected patients displayed significantly higher circulating levels of both CD40L and DKK-1, which were linearly and directly correlated, when compared to HIV-negative patients. The presence of diabetes was associated with lower levels of both CD40L and DKK-1, whereas the presence of hypertension was associated with higher levels of CD40L.

Validation of the binary designation Symbiodinium thermophilum (Dinophyceae)

The binary designation Symbiodinium thermophilum was invalid due to the absence of an illustration as required by Article 44.2 of the ICN. Herein, it is validated. This species is the most common symbiont in reef corals in the southern Persian/Arabian Gulf, the world's hottest body of water sustaining reef coral growth.

Insights into the GTP-dependent allosteric control of c-di-GMP hydrolysis from the crystal structure of PA0575 protein from Pseudomonas aeruginosa

Bis-(3'-5')-cyclic diguanylic acid (c-di-GMP) belongs to the class of cyclic dinucleotides, key carriers of cellular information in prokaryotic and eukaryotic signal transduction pathways. In bacteria, the intracellular levels of c-di-GMP and their complex physiological outputs are dynamically regulated by environmental and internal stimuli, which control the antagonistic activities of diguanylate cyclases (DGCs) and c-di-GMP specific phosphodiesterases (PDEs). Allostery is one of the major modulators of the c-di-GMP-dependent response. Both the c-di-GMP molecule and the proteins interacting with this second messenger are characterized by an extraordinary structural plasticity, which has to be taken into account when defining and possibly predicting c-di-GMP-related processes. Here, we report a structure-function relationship study on the catalytic portion of the PA0575 protein from Pseudomonas aeruginosa, bearing both putative DGC and PDE domains. The kinetic and structural studies indicate that the GGDEF-EAL portion is a GTP-dependent PDE. Moreover, the crystal structure confirms the high degree of conformational flexibility of this module. We combined structural analysis and protein engineering studies to propose the possible molecular mechanism guiding the nucleotide-dependent allosteric control of catalysis; we propose that the role exerted by GTP via the GGDEF domain is to allow the two EAL domains to form a dimer, the species competent to enter PDE catalysis.

Extremely low-frequency electromagnetic fields accelerates wound healing modulating MMP-9 and inflammatory cytokines

OBJECTIVES

In our previous reports, we have demonstrated that extremely low-frequency electromagnetic fields (ELF-EMF) exposure enhances the proliferation of keratinocyte. The present study aimed to clarify effects of ELF-EMF on wound healing and molecular mechanisms involved, using a scratch in vitro model.

MATERIALS AND METHODS

The wounded monolayer cultures of human immortalized keratinocytes (HaCaT), at different ELF-EMF and Sham exposure times were monitored under an inverted microscope. The production and expression of IL-1β, TNF-α, IL-18 and IL-18BP were measured by enzyme-linked immunosorbent assay and quantitative real-time PCR. The activity and the expression of matrix metalloproteinases (MMP)-2/9 was evaluated by zymography and Western blot analysis, respectively. Signal transduction proteins expression (Akt and ERK) was measured by Western blot.

RESULTS

The results of wound healing in vitro assay revealed a significant reduction of cell-free area time-dependent in ELF-EMF-exposed cells compared to Sham condition. Gene expression and release of cytokines analysed were significantly increased in ELF-EMF-exposed cells. Our results further showed that ELF-EMF exposure induced the activity and expressions of MMP-9. Molecular data showed that effects of ELF-EMF might be mediated via Akt and ERK signal pathway, as demonstrated using their specific inhibitors.

CONCLUSIONS

Our results highlight ability of ELF-EMF to modulate inflammation mediators and keratinocyte proliferation/migration, playing an important role in wound repair. The ELF-EMF accelerates wound healing modulating expression of the MMP-9 via Akt/ERK pathway.

Acclimatization of symbiotic corals to mesophotic light environments through wavelength transformation by fluorescent protein pigments

The depth distribution of reef-building corals exposes their photosynthetic symbionts of the genus Symbiodinium to extreme gradients in the intensity and spectral quality of the ambient light environment. Characterizing the mechanisms used by the coral holobiont to respond to the low intensity and reduced spectral composition of the light environment in deeper reefs (greater than 20 m) is fundamental to our understanding of the functioning and structure of reefs across depth gradients. Here, we demonstrate that host pigments, specifically photoconvertible red fluorescent proteins (pcRFPs), can promote coral adaptation/acclimatization to deeper-water light environments by transforming the prevalent blue light into orange-red light, which can penetrate deeper within zooxanthellae-containing tissues; this facilitates a more homogeneous distribution of photons across symbiont communities. The ecological importance of pcRFPs in deeper reefs is supported by the increasing proportion of red fluorescent corals with depth (measured down to 45 m) and increased survival of colour morphs with strong expression of pcRFPs in long-term light manipulation experiments. In addition to screening by host pigments from high light intensities in shallow water, the spectral transformation observed in deeper-water corals highlights the importance of GFP-like protein expression as an ecological mechanism to support the functioning of the coral-Symbiodinium association across steep environmental gradients.

Improvement in vaccination knowledge among health students following an integrated extra curricular intervention, an explorative study in the University of Palermo

INTRODUCTION

Vaccination coverages threaten to decrease because of false beliefs in their unsafety and inefficacy. Therefore formation of future health-care workers on this topic is fundamental to deal with any doubt and to promote active immunization among general population.

METHODS

In order to assess health-care students' knowledge about vaccination before an integrated seminar on this topic, and to evaluate their improvement after the educational intervention, an integrated educational intervention was held by a multidisciplinary team. Before and after the seminar, 118 students of medicine and biology schools at Palermo University were asked to answer 10 multiple-choice questions regarding vaccine history, mechanism of action, side effects, composition, use and nowadays issues (hesitancy). Two more questions investigating possible changes on students' attitudes towards vaccination and the usefulness of the formative intervention, were added at the post-test phase of the survey.

RESULTS

Eighty-one out of 118 students (68.6%) answered to both pre- and post-test questions. 97.6% and 81.5% of the participating group also completed the two additional questions about their improvement in knowledge (question 11) and attitudes (question 12) towards vaccinations. The post-test results showed a significant improvement for all questions administered, except for number 3 (about a specific immunological content), with an overall percentage of correct answers increasing from 38.8% to 77.6% (p©< 0.001).

CONCLUSIONS

The present explorative study put the basis for future studies, stronger in the methodology, and highlights the importance of educating health-care professions students by integrated extra-curricular intervention to be held early in their degree curricula and in order to improve knowledge and attitudes towards vaccinations and to prepare them to promote vaccines among the general population.

Phosphate deficiency promotes coral bleaching and is reflected by the ultrastructure of symbiotic dinoflagellates

Enrichment of reef environments with dissolved inorganic nutrients is considered a major threat to the survival of corals living in symbiosis with dinoflagellates (Symbiodinium sp.). We argue, however, that the direct negative effects on the symbiosis are not necessarily caused by the nutrient enrichment itself but by the phosphorus starvation of the algal symbionts that can be caused by skewed nitrogen (N) to phosphorus (P) ratios. We exposed corals to imbalanced N:P ratios in long-term experiments and found that the undersupply of phosphate severely disturbed the symbiosis, indicated by the loss of coral biomass, malfunctioning of algal photosynthesis and bleaching of the corals. In contrast, the corals tolerated an undersupply with nitrogen at high phosphate concentrations without negative effects on symbiont photosynthesis, suggesting a better adaptation to nitrogen limitation. Transmission electron microscopy analysis revealed that the signatures of ultrastructural biomarkers represent versatile tools for the classification of nutrient stress in symbiotic algae. Notably, high N:P ratios in the water were clearly identified by the accumulation of uric acid crystals.

Local bleaching thresholds established by remote sensing techniques vary among reefs with deviating bleaching patterns during the 2012 event in the Arabian/Persian Gulf

A severe bleaching event affected coral communities off the coast of Abu Dhabi, UAE in August/September, 2012. In Saadiyat and Ras Ghanada reefs ~40% of the corals showed signs of bleaching. In contrast, only 15% of the corals were affected on Delma reef. Bleaching threshold temperatures for these sites were established using remotely sensed sea surface temperature (SST) data recorded by MODIS-Aqua. The calculated threshold temperatures varied between locations (34.48 °C, 34.55 °C, 35.05 °C), resulting in site-specific deviations in the numbers of days during which these thresholds were exceeded. Hence, the less severe bleaching of Delma reef might be explained by the lower relative heat stress experienced by this coral community. However, the dominance of Porites spp. that is associated with the long-term exposure of Delma reef to elevated temperatures, as well as the more pristine setting may have additionally contributed to the higher coral bleaching threshold for this site.

Fluorescent protein-mediated colour polymorphism in reef corals: multicopy genes extend the adaptation/acclimatization potential to variable light environments

The genomic framework that enables corals to adjust to unfavourable conditions is crucial for coral reef survival in a rapidly changing climate. We have explored the striking intraspecific variability in the expression of coral pigments from the green fluorescent protein (GFP) family to elucidate the genomic basis for the plasticity of stress responses among reef corals. We show that multicopy genes can greatly increase the dynamic range over which corals can modulate transcript levels in response to the light environment. Using the red fluorescent protein amilFP597 in the coral Acropora millepora as a model, we demonstrate that its expression increases with light intensity, but both the minimal and maximal gene transcript levels vary markedly among colour morphs. The pigment concentration in the tissue of different morphs is strongly correlated with the number of gene copies with a particular promoter type. These findings indicate that colour polymorphism in reef corals can be caused by the environmentally regulated expression of multicopy genes. High-level expression of amilFP597 is correlated with reduced photodamage of zooxanthellae under acute light stress, supporting a photoprotective function of this pigment. The cluster of light-regulated pigment genes can enable corals to invest either in expensive high-level pigmentation, offering benefits under light stress, or to rely on low tissue pigment concentrations and use the conserved resources for other purposes, which is preferable in less light-exposed environments. The genomic framework described here allows corals to pursue different strategies to succeed in habitats with highly variable light stress levels. In summary, our results suggest that the intraspecific plasticity of reef corals' stress responses is larger than previously thought.

Experimental model for ELF-EMF exposure: Concern for human health

Low frequency (LF) electromagnetic fields (EMFs) are abundantly present in modern society and in the last 20 years the interest about the possible effect of extremely low frequency (ELF) EMFs on human health has increased progressively. Epidemiological studies, designed to verify whether EMF exposure may be a potential risk factor for health, have led to controversial results. The possible association between EMFs and an increased incidence of childhood leukemia, brain tumors or neurodegenerative diseases was not fully elucidated. On the other hand, EMFs are widely used, in neurology, psychiatry, rheumatology, orthopedics and dermatology, both in diagnosis and in therapy. In vitro studies may help to evaluate the mechanism by which LF-EMFs affect biological systems. In vitro model of wound healing used keratinocytes (HaCaT), neuroblastoma cell line (SH-SY5Y) as a model for analysis of differentiation, metabolism and functions related to neurodegenerative processes, and monocytic cell line (THP-1) was used as a model for inflammation and cytokines production, while leukemic cell line (K562) was used as a model for hematopoietic differentiation. MCP-1, a chemokine that regulates the migration and infiltration of memory T cells, natural killer (NK), monocytes and epithelial cells, has been demonstrated to be induced and involved in various diseases. Since, varying the parameters of EMFs different effects may be observed, we have studied MCP-1 expression in HaCaT, SH-SY5Y, THP-1 and K562 exposed to a sinusoidal EMF at 50 Hz frequency with a flux density of 1 mT (rms). Our preliminary results showed that EMF-exposure differently modifies the expression of MCP-1 in different cell types. Thus, the MCP-1 expression needs to be better determined, with additional studies, with different parameters and times of exposure to ELF-EMF.

Corals from the Persian/Arabian Gulf as models for thermotolerant reef-builders: prevalence of clade C3 Symbiodinium, host fluorescence and ex situ temperature tolerance

Corals in the Arabian/Persian Gulf endure summer temperatures of up to 36°C, making them ideal subjects to study the mechanisms underlying thermal tolerance. Unexpectedly, we found the "generalist" Symbiodinium clade C3 to be the prevalent symbiont among seven coral species from Abu Dhabi (UAE) waters. Moreover, C3 represented the only dominant symbiont type in Porites spp. from this region. The "thermotolerant" symbionts D1a and C15 were not encountered, indicating that the association with these symbionts cannot be the sole reason for the heat tolerance of Gulf corals. The association of Porites lobata with specific symbiont types (C3 vs. C15) in samples from habitats with very different temperature regimes (Abu Dhabi vs. Fiji) remained unaffected by laboratory culture. During temperature stress experiments specimens from both locations strongly downregulated green fluorescent protein (GFP)-like pigments. However, the Abu Dhabi samples were less prone to bleaching and showed lower mortality.

IL-22 defines a novel immune pathway of antifungal resistance

The role of IL-17 and Th17 cells in immunity vs. pathology associated with the human commensal Candida albicans remains controversial. Both positive and negative effects on immune resistance have been attributed to IL-17/Th17 in experimental candidiasis. In this study, we provide evidence that IL-22, which is also produced by Th17 cells, has a critical, first-line defense in candidiasis by controlling the growth of infecting yeasts as well as by contributing to the host's epithelial integrity in the absence of acquired Th1-type immunity. The two pathways are reciprocally regulated, and IL-22 is upregulated under Th1 deficiency conditions and vice versa. Whereas both IL-17A and F are dispensable for antifungal resistance, IL-22 mediates protection in IL-17RA-deficient mice, in which IL-17A contributes to disease susceptibility. Thus, our findings suggest that protective immunity to candidiasis is made up of a staged response involving an early, IL-22-dominated response followed by Th1/Treg reactivity that will prevent fungal dissemination and supply memory.

[Pelvic masses in young women: a case of giant uterine fibroleiomyomatosis]

The authors reported a particular case of giant uterine fibroleiomyomatosis in young women and describe some clinical feature and differential diagnoses.

A green fluorescent protein with photoswitchable emission from the deep sea

A colorful variety of fluorescent proteins (FPs) from marine invertebrates are utilized as genetically encoded markers for live cell imaging. The increased demand for advanced imaging techniques drives a continuous search for FPs with new and improved properties. Many useful FPs have been isolated from species adapted to sun-flooded habitats such as tropical coral reefs. It has yet remained unknown if species expressing green fluorescent protein (GFP)-like proteins also exist in the darkness of the deep sea. Using a submarine-based and -operated fluorescence detection system in the Gulf of Mexico, we discovered ceriantharians emitting bright green fluorescence in depths between 500 and 600 m and identified a GFP, named cerFP505, with bright fluorescence emission peaking at 505 nm. Spectroscopic studies showed that ∼15% of the protein bulk feature reversible ON/OFF photoswitching that can be induced by alternating irradiation with blue und near-UV light. Despite being derived from an animal adapted to essentially complete darkness and low temperatures, cerFP505 maturation in living mammalian cells at 37°C, its brightness and photostability are comparable to those of EGFP and cmFP512 from shallow water species. Therefore, our findings disclose the deep sea as a potential source of GFP-like molecular marker proteins.

P53 and bcl-2 in colorectal cancer arising in patients under 40 years of age: distribution and prognostic relevance

Young people (40 years of age) with colorectal cancer (CRC) represent a distinct subgroup with more aggressive disease behaviour compared to older patients. We evaluate whether p53 and bcl-2 could be useful in identifying young patients at higher risk of tumour progression. We reviewed 1340 CRC patients with 58 patients 40 years (4.2%). They had more frequent moderately or poorly differentiated mucinous adenocarcinomas (26% versus 12.3%, p=0.03); higher advanced stage at diagnosis; shorter 5-year overall survival (49.8% versus 71%; p=0.02); more frequent p53 positive (89.8% versus 72.6%, p<0.05) and bcl-2 negative (88.0% versus 66.2%, p<0.05) tumours; no difference in DNA content or proliferation indexes. Moreover, p53+ and bcl-2- resulted in being independent predictors of survival with shorter survival for the p53+/bcl-2- patients. Combining p53 and bcl-2, we could identify young CRC patients at higher risk of progression, who probably require development of a more sophisticated therapeutic approach based on identification of predictive factors.

State and trait anxiety and depression in patients affected by gastrointestinal diseases: psychometric evaluation of 1641 patients referred to an internal medicine outpatient setting

OBJECTIVES

To evaluate state and trait form of anxiety and current depression in patients affected by gastrointestinal diseases.

METHODS

We studied 1641 outpatients with gastrointestinal disorders, consecutively referred to our Internal Medicine outpatients from 1997 to 2005. State and trait anxiety were assessed by the State and Trait Anxiety Inventory. Current depression was assessed by the Zung self-rating depression scale.

RESULTS

Among patients, 1379 (84.1%) showed state anxiety, 1098 (67%) showed trait anxiety and 442 (27%) showed current depression. The number of gastrointestinal diseases was directly correlated to state anxiety (p < 0.001) and trait anxiety (p = 0.04). Females showed higher levels of anxiety and depression than males (p < 0.001). State anxiety was related to food allergies (p < 0.001), small intestinal bacterial overgrowth (SIBO) (p = 0.001), Hp infection (p = 0.01) and ulcerative colitis in active phase (p = 0.03). Trait anxiety was related to irritable bowel syndrome (IBS) (p < 0.001), Helicobacter pylori (Hp) infection (p = 0.001), food allergies (p = 0.001) and SIBO (p = 0.001). Current depression was related to IBS (p < 0.001) and coeliac disease (p = 0.01), SIBO (p = 0.02). A predicted probability of 0.77 +/- 0.16 to have state anxiety, of 0.66 +/- 0.12 to have trait anxiety and of 0.39 +/- 0.14 to have depression was found in these patients.

CONCLUSIONS

Most of the patients who seek medical consultation for gastrointestinal problems show an associated affective disorder. These patients should be managed by a team including gastroenterologists, psychologists and/or psychiatrists, or by a gastroenterologist having expertise in the treatment of psychological disorders.

It's cheap to be colorful. Anthozoans show a slow turnover of GFP-like proteins

Pigments homologous to the green fluorescent protein (GFP) contribute up to approximately 14% of the soluble protein content of many anthozoans. Maintenance of such high tissue levels poses a severe energetic penalty to the animals if protein turnover is fast. To address this as yet unexplored issue, we established that the irreversible green-to-red conversion of the GFP-like pigments from the reef corals Montastrea cavernosa (mcavRFP) and Lobophyllia hemprichii (EosFP) is driven by violet-blue radiation in vivo and in situ. In the absence of photoconverting light, we subsequently tracked degradation of the red-converted forms of the two proteins in coral tissue using in vivo spectroscopy and immunochemical detection of the post-translational peptide backbone modification. The pigments displayed surprisingly slow decay rates, characterized by half-lives of approximately 20 days. The slow turnover of GFP-like proteins implies that the associated energetic costs for being colorful are comparatively low. Moreover, high in vivo stability makes GFP-like proteins suitable for functions requiring high pigment concentrations, such as photoprotection.

The AtGenExpress global stress expression data set: protocols, evaluation and model data analysis of UV-B light, drought and cold stress responses

The tolerance responses of plants to many abiotic stresses are conjectured to be controlled by complex gene networks. In the frame of the AtGenExpress project a comprehensive Arabidopsis thaliana genome transcript expression study was performed using the Affymetrix ATH1 microarray in order to understand these regulatory networks in detail. In contrast to earlier studies, we subjected, side-by-side and in a high-resolution kinetic series, Arabidopsis plants, of identical genotype grown under identical conditions, to different environmental stresses comprising heat, cold, drought, salt, high osmolarity, UV-B light and wounding. Furthermore, the harvesting of tissue and RNA isolation were performed in parallel at the same location using identical experimental protocols. Here we describe the technical performance of the experiments. We also present a general overview of environmental abiotic stress-induced gene expression patterns and the results of a model bioinformatics analysis of gene expression in response to UV-B light, drought and cold stress. Our results suggest that the initial transcriptional stress reaction of Arabidopsis might comprise a set of core environmental stress response genes which, by adjustment of the energy balance, could have a crucial function in various stress responses. In addition, there are indications that systemic signals generated by the tissue exposed to stress play a major role in the coordination and execution of stress responses. In summary, the information reported provides a prime reference point and source for the subsequent exploitation of this important resource for research into plant abiotic stress.

[Use of Tachosil in splenectomy in patients with clotting and blood composition disorders]

Splenectomy in patients suffering from onco-haematological conditions presents clotting-related problems which make correct haemostasis more difficult. Using operative haemostasis during splenectomy for onco-haematological conditions as a starting point, the authors report their personal clinical experience of the use of Tachosil, comparing it with other similar products and drawing some personal

CONCLUSIONS

To complete their reflexions on clotting problems during splenectomy in the course of onco-haematological diseases, the comparison with its use in oncological pathologies in other parenchymas, such as the kidney and liver, which also present operative haemostatic difficulties of a technical nature, is pointed out and the soundness of the results indicated. The cases of 3 patients suffering from severe clotting disturbances and treated with splenectomy and 1 patient suffering from clear cell renal carcinoma and subjected to nephrectomy in which Tachosil was used as an aid to haemostasis are reported. In the light of these cases, it can be stated that, albeit with the persistence of difficulties related to the changed clotting capacities resulting from the basic disease, the use of Tachosil has proved effective as an aid in haemostasis and suggests the validity of its use in elective and emergency splenectomy, in these types of patient.

Contributions of host and symbiont pigments to the coloration of reef corals

For a variety of coral species, we have studied the molecular origin of their coloration to assess the contributions of host and symbiont pigments. For the corals Catalaphyllia jardinei and an orange-emitting color morph of Lobophyllia hemprichii, the pigments belong to a particular class of green fluorescent protein-like proteins that change their color from green to red upon irradiation with approximately 400 nm light. The optical absorption and emission properties of these proteins were characterized in detail. Their spectra were found to be similar to those of phycoerythrin from cyanobacterial symbionts. To unambiguously determine the molecular origin of the coloration, we performed immunochemical studies using double diffusion in gel analysis on tissue extracts, including also a third coral species, Montastrea cavernosa, which allowed us to attribute the red fluorescent coloration to green-to-red photoconvertible fluorescent proteins. The red fluorescent proteins are localized mainly in the ectodermal tissue and contribute up to 7.0% of the total soluble cellular proteins in these species. Distinct spatial distributions of green and cyan fluorescent proteins were observed for the tissues of M. cavernosa. This observation may suggest that differently colored green fluorescent protein-like proteins have different, specific functions. In addition to green fluorescent protein-like proteins, the pigments of zooxanthellae have a strong effect on the visual appearance of the latter species.

Alternative complex formation of the Ca-regulated protein kinase CIPK1 controls abscisic acid-dependent and independent stress responses in Arabidopsis

Intracellular release of calcium ions belongs to the earliest events in cellular stress perception. The molecular mechanisms integrating signals from different environmental cues and translating them into an optimized response are largely unknown. We report here the functional characterization of CIPK1, a protein kinase interacting strongly with the calcium sensors CBL1 and CBL9. Comparison of the expression patterns indicates that the three proteins execute their functions in the same tissues. Physical interaction of CIPK1 with CBL1 and CBL9 targets the kinase to the plasma membrane. We show that, similarly to loss of CBL9 function, mutation of either CBL1 or CIPK1 renders plants hypersensitive to osmotic stress. Remarkably, in contrast to the cbl1 mutant and similarly to the cbl9 mutant, loss of CIPK1 function impairs abscisic acid (ABA) responsiveness. We therefore suggest that, by alternative complex formation with either CBL1 or CBL9, the kinase CIPK1 represents a convergence point for ABA-dependent and ABA-independent stress responses. Based on our genetic, physiological and protein-protein interaction data, we propose a general model for information processing in calcium-regulated signalling networks.

Alternative complex formation of the Ca-regulated protein kinase CIPK1 controls abscisic acid-dependent and independent stress responses in Arabidopsis

Intracellular release of calcium ions belongs to the earliest events in cellular stress perception. The molecular mechanisms integrating signals from different environmental cues and translating them into an optimized response are largely unknown. We report here the functional characterization of CIPK1, a protein kinase interacting strongly with the calcium sensors CBL1 and CBL9. Comparison of the expression patterns indicates that the three proteins execute their functions in the same tissues. Physical interaction of CIPK1 with CBL1 and CBL9 targets the kinase to the plasma membrane. We show that, similarly to loss of CBL9 function, mutation of either CBL1 or CIPK1 renders plants hypersensitive to osmotic stress. Remarkably, in contrast to the cbl1 mutant and similarly to the cbl9 mutant, loss of CIPK1 function impairs abscisic acid (ABA) responsiveness. We therefore suggest that, by alternative complex formation with either CBL1 or CBL9, the kinase CIPK1 represents a convergence point for ABA-dependent and ABA-independent stress responses. Based on our genetic, physiological and protein-protein interaction data, we propose a general model for information processing in calcium-regulated signalling networks.

[A surgical emergency: iatrogenic lesion of the spleen. Case report and review of the literature]

The spleen is an organ often injured during surgical procedures. Iatrogenic lesions belong frequently to a low grade and can be treated with a conservative therapy. The surgeon may avoid the splenectomy by using new haemostatic agents as the patch of fibrinogen and thrombin in fixed combination.

The calcium sensor calcineurin B-like 9 modulates abscisic acid sensitivity and biosynthesis in Arabidopsis

Calcium plays a pivotal role in plant responses to several stimuli, including pathogens, abiotic stresses, and hormones. However, the molecular mechanisms underlying calcium functions are poorly understood. It is hypothesized that calcium serves as second messenger and, in many cases, requires intracellular protein sensors to transduce the signal further downstream in the pathways. The calcineurin B-like proteins (CBLs) represent a unique family of calcium sensors in plant cells. Here, we report our analysis of the CBL9 member of this gene family. Expression of CBL9 was inducible by multiple stress signals and abscisic acid (ABA) in young seedlings. When CBL9 gene function was disrupted in Arabidopsis thaliana plants, the responses to ABA were drastically altered. The mutant plants became hypersensitive to ABA in the early developmental stages, including seed germination and post-germination seedling growth. In addition, seed germination in the mutant also showed increased sensitivity to inhibition by osmotic stress conditions produced by high concentrations of salt and mannitol. Further analyses indicated that increased stress sensitivity in the mutant may be a result of both ABA hypersensitivity and increased accumulation of ABA under the stress conditions. The cbl9 mutant plants showed enhanced expression of genes involved in ABA signaling, such as ABA-INSENSITIVE 4 and 5. This study has identified a calcium sensor as a common element in the ABA signaling and stress-induced ABA biosynthesis pathways.