Heterogeneity of sensitization profiles and clinical phenotypes among patients with seasonal allergic rhinitis in Southern European countries-The @IT.2020 multicenter study

BACKGROUND

Pollen allergy poses a significant health and economic burden in Europe. Disease patterns are relatively homogeneous within Central and Northern European countries. However, no study broadly assessed the features of seasonal allergic rhinitis (SAR) across different Southern European countries with a standardized approach.

OBJECTIVE

To describe sensitization profiles and clinical phenotypes of pollen allergic patients in nine Southern European cities with a uniform methodological approach.

METHODS

Within the @IT.2020 multicenter observational study, pediatric and adult patients suffering from SAR were recruited in nine urban study centers located in seven countries. Clinical questionnaires, skin prick tests (SPT) and specific IgE (sIgE) tests with a customized multiplex assay (Euroimmun Labordiagnostika, Lübeck, Germany) were performed.

RESULTS

Three hundred forty-eight children (mean age 13.1 years, SD: 2.4 years) and 467 adults (mean age 35.7 years SD: 10.0 years) with a predominantly moderate to severe, persistent phenotype of SAR were recruited. Grass pollen major allergenic molecules (Phl p 1 and/or Phl p 5) ranged among the top three sensitizers in all study centers. Sensitization profiles were very heterogeneous, considering that patients in Rome were highly poly-sensitized (sIgE to 3.8 major allergenic molecules per patient), while mono-sensitization was prominent and heterogeneous in other cities, such as Marseille (sIgE to Cup a 1: n = 55/80, 68.8%) and Messina (sIgE to Par j 2: n = 47/82, 57.3%). Co-sensitization to perennial allergens, as well as allergic comorbidities also broadly varied between study centers.

CONCLUSIONS

In Southern European countries, pollen allergy is heterogeneous in terms of sensitization profiles and clinical manifestations. Despite the complexity, a unique molecular, multiplex, and customized in-vitro IgE test detected relevant sensitization in all study centers. Nevertheless, this geographical diversity in pollen allergic patients imposes localized clinical guidelines and study protocols for clinical trials of SAR in this climatically complex region.

Structural basis for competitive binding of productive and degradative co-transcriptional effectors to the nuclear cap-binding complex

The nuclear cap-binding complex (CBC) coordinates co-transcriptional maturation, transport, or degradation of nascent RNA polymerase II (Pol II) transcripts. CBC with its partner ARS2 forms mutually exclusive complexes with diverse "effectors" that promote either productive or destructive outcomes. Combining AlphaFold predictions with structural and biochemical validation, we show how effectors NCBP3, NELF-E, ARS2, PHAX, and ZC3H18 form competing binary complexes with CBC and how PHAX, NCBP3, ZC3H18, and other effectors compete for binding to ARS2. In ternary CBC-ARS2 complexes with PHAX, NCBP3, or ZC3H18, ARS2 is responsible for the initial effector recruitment but inhibits their direct binding to the CBC. We show that in vivo ZC3H18 binding to both CBC and ARS2 is required for nuclear RNA degradation. We propose that recruitment of PHAX to CBC-ARS2 can lead, with appropriate cues, to competitive displacement of ARS2 and ZC3H18 from the CBC, thus promoting a productive rather than a degradative RNA fate.

Structure shows that the BIR2 domain of E3 ligase XIAP binds across the RIPK2 kinase dimer interface

RIPK2 is an essential adaptor for NOD signalling and its kinase domain is a drug target for NOD-related diseases, such as inflammatory bowel disease. However, recent work indicates that the phosphorylation activity of RIPK2 is dispensable for signalling and that inhibitors of both RIPK2 activity and RIPK2 ubiquitination prevent the essential interaction between RIPK2 and the BIR2 domain of XIAP, the key RIPK2 ubiquitin E3 ligase. Moreover, XIAP BIR2 antagonists also block this interaction. To reveal the molecular mechanisms involved, we combined native mass spectrometry, NMR, and cryo-electron microscopy to determine the structure of the RIPK2 kinase BIR2 domain complex and validated the interface with in cellulo assays. The structure shows that BIR2 binds across the RIPK2 kinase antiparallel dimer and provides an explanation for both inhibitory mechanisms. It also highlights why phosphorylation of the kinase activation loop is dispensable for signalling while revealing the structural role of RIPK2-K209 residue in the RIPK2-XIAP BIR2 interaction. Our results clarify the features of the RIPK2 conformation essential for its role as a scaffold protein for ubiquitination.

Architecture of the MKK6-p38α complex defines the basis of MAPK specificity and activation

The mitogen-activated protein kinase (MAPK) p38α is a central component of signaling in inflammation and the immune response and is, therefore, an important drug target. Little is known about the molecular mechanism of its activation by double phosphorylation from MAPK kinases (MAP2Ks), because of the challenge of trapping a transient and dynamic heterokinase complex. We applied a multidisciplinary approach to generate a structural model of p38α in complex with its MAP2K, MKK6, and to understand the activation mechanism. Integrating cryo-electron microscopy with molecular dynamics simulations, hydrogen-deuterium exchange mass spectrometry, and experiments in cells, we demonstrate a dynamic, multistep phosphorylation mechanism, identify catalytically relevant interactions, and show that MAP2K-disordered amino termini determine pathway specificity. Our work captures a fundamental step of cell signaling: a kinase phosphorylating its downstream target kinase.

Burden and resources in caregivers of people with multiple sclerosis: A qualitative study

BACKGROUND

Caregivers of people with Multiple Sclerosis are required to provide ongoing assistance especially during the advanced stages of the disease. They have to manage interventions and assume responsibilities which significantly impact both their personal quality of life and family's dynamics.

OBJECTIVE

A qualitative phenomenological study was carried out to understand the experience of burden in caregivers and their resources to manage it. The study also explores how healthcare services involved in the Multiple Sclerosis Clinical Pathway respond to the needs of well-being of patients and family members.

METHODS

17 caregivers were involved in focus groups and in semi-structured individual interviews.

RESULTS

Fatigue is experienced by all respondents and it starts when physical disabilities increase or when people become aware of them. Many caregivers declare that they refer to intrinsic (love towards their relatives, patience and dedication) or extrinsic (family members, hobbies) resources to cope with the burden of assistance. Patient associations and the Multiple Sclerosis Clinical Pathway play a significant role in supporting caregivers.

CONCLUSIONS

Fatigue, loneliness, and isolation are experienced by caregivers and strongly affect their quality of life and health status. The study highlights caregivers' need to reconcile working times with care times, to give more space to self-care and to have moments to share their experiences with someone else. These needs should be at the core of health policies in order to avoid physical and emotional breakdowns which could lead to the rupture of the relational balance on which home care is based.

Stand age, degree of encroachment and soil characteristics modulate changes of C and N cycles in dry grassland soils invaded by the N2-fixing shrub Amorpha fruticosa

The N₂-fixing shrub Amorpha fruticosa L. is rapidly spreading in the dry riparian natural grasslands of Europe, altering ecosystem functions and depleting plant diversity. Alteration of the N cycle represents the key factor involved in invasions by N₂-fixing plants with cascading effects on plant species richness. We hypothesized that A. fruticosa encroachment strongly impacts not only the N but also the C cycle and that the magnitude of such alterations may be modulated by soil characteristics. To test these hypotheses, we selected four river floodplains in North East of Italy and compared natural uninvaded grasslands with half invaded and completely invaded sites, based on A. fruticosa stand characteristic and relevant leaf traits and on soil properties related to soil texture and to C and N cycles. Soil organic matter mineralisation, ammonification and nitrification rates were determined. Soil nitrification increased remarkably with plant invasion while ammonification was significantly higher only in half invaded sites. Soil organic matter mineralisation, microbial biomass C sustained per soil organic C unit and nitrification positively correlated with stand age, regardless to the stage of the encroachment. Mineralisation and nitrification increased with soil organic C and total N in uninvaded and completely invaded sites, but decreased in half invaded sites. At the half invasion stage, trends in nitrification and CO₂ mineralisation were transitionally reverted and remediation may be facilitated by less pronounced changes in soil properties compared to completely invaded sites. Direct effects of plant invasion are modulated by the action of soil characteristics such as soil organic C and clay contents, with soils rich in organic C showing larger nitrification and mineralisation rates.

Agricultural land use curbs exotic invasion but sustains native plant diversity at intermediate levels

Unveiling the processes driving exotic plant invasion represent a central issue in taking decisions aimed at constraining the loss of biodiversity and related ecosystem services. The invasion success is often linked to anthropogenic land uses and warming due to climate change. We studied the responses of native versus casual and naturalised exotic species richness to land uses and climate at the landscape level, relying on a large floristic survey undertaken in North - Eastern Italy. Both climate and land use drove exotic species richness. Our results suggest that the success of plant invasion at this scale is mainly due to warm climatic conditions and the extent of urban and agricultural land, but with different effects on casual and naturalized exotic species. The occurrence of non-linear trends showed that a small percentage of extensive agricultural land in the landscape may concurrently reduce the number of exotic plant while sustaining native plant diversity. Plant invasion could be potentially limited by land management, mainly focusing on areas with extensive agricultural land use. A more consciousness land management is more and more commonly required by local administrations. According to our results, a shift of intensive to extensive agricultural land, by implementing green infrastructures, seems to be a win-win solution favouring native species while controlling the oversimplification of the flora due to plant invasion.

Personality disorder not otherwise specified heterogeneity and its implication in psychiatric residential treatment

Introduction

Villa Ratti is a therapeutic community dedicated to the treatment of Personality Disorder with a particular focus on Borderline Personality Disorder (BPD), but this diagnosis may manifest in very different clinical conditions (Bayer & Parker, 2017; Scott, 2017).

Objectives

Since the second most common diagnosis we encounter from referring psychiatrists is Personality Disorder Not Otherwise Specified (PDNOS) (26,4%) and this diagnosis serves sometimes as a skeleton key for complex or unclear diagnostic scenarios (Verheul & Widiger, 2004), our main goal is to investigate how the variability within this category is reflected in terms of diagnostic accuracy, different development of the therapeutic and rehabilitative course, and of different outcomes at the end of the treatment.

Methods

To reach this goal, we collected data on all patients referred with a PDNOS diagnosis and compared their treatment program. scenarios.

Results

Our data showed how a PDNOS diagnosis hid in most cases complex personality disorders and comorbidities that reflected different specific difficulties and interventions during their treatment and, consequently, resulted in different outcomes.

Conclusions

Our experience led us to give additional attention to referred PDNOS diagnosis and to observe how much a clear diagnostic picture of a patient is crucial to correctly plan a treatment program and adapt local service interventions both for personality disorder and comorbidity

A GAP-GTPase-GDP-Pi Intermediate Crystal Structure Analyzed by DFT Shows GTP Hydrolysis Involves Serial Proton Transfers

Cell signaling by small G proteins uses an ON to OFF signal based on conformational changes following the hydrolysis of GTP to GDP and release of dihydrogen phosphate (Pi ). The catalytic mechanism of GTP hydrolysis by RhoA is strongly accelerated by a GAP protein and is now well defined, but timing of inorganic phosphate release and signal change remains unresolved. We have generated a quaternary complex for RhoA-GAP-GDP-Pi . Its 1.75 Å crystal structure shows geometry for ionic and hydrogen bond coordination of GDP and Pi in an intermediate state. It enables the selection of a QM core for DFT exploration of a 20 H-bonded network. This identifies serial locations of the two mobile protons from the original nucleophilic water molecule, showing how they move in three rational steps to form a stable quaternary complex. It also suggests how two additional proton transfer steps can facilitate Pi release.

Mercury uptake by halophytes in response to a long-term contamination in coastal wetland salt marshes (northern Adriatic Sea)

Mercury (Hg) distribution in saltmarsh sediments and in three selected halophytes (Limonium narbonense, Sarcocornia fruticosa and Atriplex portulacoides) of a wetland system (Marano and Grado Lagoon, Italy) following a contamination gradient in sediments was investigated. The Hg uptake was evaluated at the root system level by calculating the enrichment factor (EF) and in the aboveground tissues by means of the translocation factor (TF). The related methylmercury (MeHg) concentrations in the halophytes were also investigated with regard to the location of the sites and their degree of contamination. Hg concentration in halophytes seemed poorly correlated both with the total Hg in rhizo-sediments and with the specific plant considered, supporting the evidence that the chemico-physical parameters of sediments could significantly affect metal availability for plants. Hg concentrations in roots increased with depth and were 20-fold higher than content measured in related rhizo-sediments (high EF). A low content of Hg is translocated in aboveground tissues (very low TF values), thus highlighting a kind of avoidance strategy of these halophytes against Hg toxicity. MeHg values were comparable between the two sites and among species, but the translocation from below- to aboveground plant tissues was more active.

Assessing the Influence of Mutation on GTPase Transition States by Using X-ray Crystallography, 19 F NMR, and DFT Approaches

We report X-ray crystallographic and ¹⁹ F NMR studies of the G-protein RhoA complexed with MgF₃^- , GDP, and RhoGAP, which has the mutation Arg85'Ala. When combined with DFT calculations, these data permit the identification of changes in transition state (TS) properties. The X-ray data show how Tyr34 maintains solvent exclusion and the core H-bond network in the active site by relocating to replace the missing Arg85' sidechain. The ¹⁹ F NMR data show deshielding effects that indicate the main function of Arg85' is electronic polarization of the transferring phosphoryl group, primarily mediated by H-bonding to O^3G and thence to P^G . DFT calculations identify electron-density redistribution and pinpoint why the TS for guanosine 5'-triphosphate (GTP) hydrolysis is higher in energy when RhoA is complexed with RhoGAP_Arg85'Ala relative to wild-type (WT) RhoGAP. This study demonstrates that ¹⁹ F NMR measurements, in combination with X-ray crystallography and DFT calculations, can reliably dissect the response of small GTPases to site-specific modifications.

Structures of the inactive and active states of RIP2 kinase inform on the mechanism of activation

Innate immune receptors NOD1 and NOD2 are activated by bacterial peptidoglycans leading to recruitment of adaptor kinase RIP2, which, upon phosphorylation and ubiquitination, becomes a scaffold for downstream effectors. The kinase domain (RIP2K) is a pharmaceutical target for inflammatory diseases caused by aberrant NOD2-RIP2 signalling. Although structures of active RIP2K in complex with inhibitors have been reported, the mechanism of RIP2K activation remains to be elucidated. Here we analyse RIP2K activation by combining crystal structures of the active and inactive states with mass spectrometric characterization of their phosphorylation profiles. The active state has Helix αC inwardly displaced and the phosphorylated Activation Segment (AS) disordered, whilst in the inactive state Helix αC is outwardly displaced and packed against the helical, non-phosphorylated AS. Biophysical measurements show that the active state is a stable dimer whilst the inactive kinase is in a monomer-dimer equilibrium, consistent with the observed structural differences at the dimer interface. We conclude that RIP2 kinase auto-phosphorylation is intimately coupled to dimerization, similar to the case of BRAF. Our results will help drug design efforts targeting RIP2 as a potential treatment for NOD2-RIP2 related inflammatory diseases.

MDANSE: An Interactive Analysis Environment for Molecular Dynamics Simulations

The MDANSE software-Molecular Dynamics Analysis of Neutron Scattering Experiments-is presented. It is an interactive application for postprocessing molecular dynamics (MD) simulations. Given the widespread use of MD simulations in material and biomolecular sciences to get a better insight for experimental techniques such as thermal neutron scattering (TNS), the development of MDANSE has focused on providing a user-friendly, interactive, graphical user interface for analyzing many trajectories in the same session and running several analyses simultaneously independently of the interface. This first version of MDANSE already proposes a broad range of analyses, and the application has been designed to facilitate the introduction of new analyses in the framework. All this makes MDANSE a valuable tool for extracting useful information from trajectories resulting from a wide range of MD codes.

Structural Basis for the Subversion of MAP Kinase Signaling by an Intrinsically Disordered Parasite Secreted Agonist

The causative agent of toxoplasmosis, the intracellular parasite Toxoplasma gondii, delivers a protein, GRA24, into the cells it infects that interacts with the mitogen-activated protein (MAP) kinase p38α (MAPK14), leading to activation and nuclear translocation of the host kinase and a subsequent inflammatory response that controls the progress of the parasite. The purification of a recombinant complex of GRA24 and human p38α has allowed the molecular basis of this activation to be determined. GRA24 is shown to be intrinsically disordered, binding two kinases that act independently, and is the only factor required to bypass the canonical mitogen-activated protein kinase activation pathway. An adapted kinase interaction motif (KIM) forms a highly stable complex that competes with cytoplasmic regulatory partners. In addition, the recombinant complex forms a powerful in vitro tool to evaluate the specificity and effectiveness of p38α inhibitors that have advanced to clinical trials, as it provides a hitherto unavailable stable and highly active form of p38α.

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Toxoplasmosis controls its host immune response via a protein effector, GRA24

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A recombinant complex of GRA24 and MAPK p38α demonstrates how the protein works

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An adapted KIM domain ensures activation and a sustained inflammatory response

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The recombinant complex is useful in the evaluation of p38 inhibitors

Test-Retest Reliability of a Psychometric Instrument Designed to Measure Physical Therapy Students’ Burnout

The purpose of this study was to assess the reproducibility of scores on an instrument designed to measure physical therapy students’ burnout. Physical therapy students (28 juniors and 28 seniors) completed an adapted educators version of the Maslach Burnout Inventory on two occasions within a week interval. At each testing session, a separate score was obtained for each student for the three (emotional exhaustion, depersonalization, and personal accomplishment) subscales of the instrument. These scores, analyzed with a two-factor repeated-measures analysis of variance, indicated a significant difference in the personal accomplishment score between the junior and senior students during the two time frames. Scheffé post hoc tests showed that the junior students reported higher personal accomplishment affect at both testing sessions than the senior students. Both junior and senior students reported higher personal accomplishment at retest than at baseline testing. A test-retest reliability coefficient of .850 was obtained for the Depersonalization subscale; .907 and .715 were obtained for the Emotional Exhaustion and Personal Accomplishment subscales, respectively.

Structure and dynamics of ionic micelles: MD simulation and neutron scattering study

Fully atomistic molecular dynamics (MD) simulations have been carried out on sodium dodecyl sulfate (SDS), an anionic micelle, and three cationic (CnTAB; n = 12, 14, 16) micelles, investigating the effects of size, the form of the headgroup, and chain length. They have been used to analyze neutron scattering data. MD simulations confirm the dynamical model of global motion of the whole micelle, segmental motion (headgroup and alkyl chain), and fast torsional motion associated with the surfactants that is used to analyze the experimental data. It is found that the solvent surrounding the headgroups results in their significant mobility, which exceeds that of the tails on the nanosecond time scale. The middle of the chain is found to be least mobile, consolidating the micellar configuration. This dynamical feature is similar for all the ionic micelles investigated and therefore independent of headgroup form and charge and chain length. Diffusion constants for global and segmental motion of the different micelles are consistent with experimentally obtained values as well as known structural features. This work provides a more realistic model of micelle dynamics and offers new insight into the strongly fluctuating surface of micelles which is important in understanding micelle dispersion and related functionality, like drug delivery.

Inclusion of new 5-fluorouracil amphiphilic derivatives in liposome formulation for cancer treatment

Liposomes containing novel 5-fluorouracil derivatives differing in the length of their polyoxyethylenic spacer were shown active against colorectal tumor cells.

Painting biological low-frequency vibrational modes from small peptides to proteins

We use experiments and simulation to investigate the validity of different model systems used to study the low-frequency vibrations of proteins.

α-Fluorophosphonates reveal how a phosphomutase conserves transition state conformation over hexose recognition in its two-step reaction

β-Phosphoglucomutase (βPGM) catalyzes isomerization of β-D-glucose 1-phosphate (βG1P) into D-glucose 6-phosphate (G6P) via sequential phosphoryl transfer steps using a β-D-glucose 1,6-bisphosphate (βG16BP) intermediate. Synthetic fluoromethylenephosphonate and methylenephosphonate analogs of βG1P deliver novel step 1 transition state analog (TSA) complexes for βPGM, incorporating trifluoromagnesate and tetrafluoroaluminate surrogates of the phosphoryl group. Within an invariant protein conformation, the β-D-glucopyranose ring in the βG1P TSA complexes (step 1) is flipped over and shifted relative to the G6P TSA complexes (step 2). Its equatorial hydroxyl groups are hydrogen-bonded directly to the enzyme rather than indirectly via water molecules as in step 2. The (C)O-P bond orientation for binding the phosphate in the inert phosphate site differs by ∼ 30° between steps 1 and 2. By contrast, the orientations for the axial O-Mg-O alignment for the TSA of the phosphoryl group in the catalytic site differ by only ∼ 5°, and the atoms representing the five phosphorus-bonded oxygens in the two transition states (TSs) are virtually superimposable. The conformation of βG16BP in step 1 does not fit into the same invariant active site for step 2 by simple positional interchange of the phosphates: the TS alignment is achieved by conformational change of the hexose rather than the protein.

Risk for cardiovascular events in an Italian population of patients with type 2 diabetes

BACKGROUND AND AIM

This study aims to analyse the risk of cardiovascular events in a local cohort of patients with type 2 diabetes, and to evaluate the prognostic accuracy of four algorithms used to estimate cardiovascular risk: the Framingham study, United Kingdom Prospective Diabetes Study (UKPDS), Riskard study and Progetto Cuore.

METHOD AND RESULTS

We analysed clinical charts of the Diabetes Clinics of Modena for the period 1991-95. Patients in the age range of 35-65 with type 2 diabetes and no previous cardiovascular disease were eligible. The incidence of new cardiovascular disease was compared with estimated rates deriving from the different functions. A stratification was obtained in subgroups at different cardiovascular risk, allowing comparison between the algorithms. A total of 1532 patients were eligible; women presented a worse cardiovascular risk profile. An absolute 10-year rate of cardiovascular events of 14.9% was observed. Comparing patients with events with event-free subjects, we found significant differences in systolic blood pressure, age at visit, smoking, high-density lipoprotein (HDL)-cholesterol, duration of diabetes, glycosylated haemoglobin (HbA1c) and co-morbidities. Comparing the estimated risk rate according to the different functions, Italian algorithms were more consistent with observed data; however, Progetto Cuore and Riskard show underestimation of events when applied to females.

CONCLUSIONS

Estimation of cardiovascular risk is dependent on the algorithm adopted and on the baseline risk of the reference cohort. Functions designed for a specific population, including risk variables peculiar for diabetes, should be adopted to increase the performance of such functions which is clearly unsatisfactory at present.

Direct cryocooling of naked crystals: are cryoprotection agents always necessary?

Over the last 20 years cryocrystallography has revolutionized the field of macromolecular crystallography, greatly reducing radiation damage and allowing the collection of complete data sets at synchrotron sources. However, in order to cool crystals to 100 K cryoprotective agents must usually be added to prevent the formation of crystalline ice, which disrupts the macromolecular crystal lattice and often results in a degradation of diffraction quality. This process can involve the extensive testing of solution compositions and soaking protocols to find suitable conditions that maintain diffraction quality. In this study, it is demonstrated that when some crystals of macromolecules are mounted in the complete absence of surrounding liquid no crystalline ice is formed and the diffraction resolution, merging R factors and mosaic spread values are comparable to those of crystals cryocooled in the presence of a cryoprotectant. This potentially removes one of the most onerous manual steps in the structure-solution pipeline and could alleviate some of the foreseen difficulties in the automation of crystal mounting.

Neutron scattering and ab initio molecular dynamics study of cross-linking in biomedical phosphate glasses

Details of the microscopic structure of phosphate glasses destined for biomedical applications, which include sodium, magnesium and calcium cations, have been obtained from the static structure factor measured by means of neutron scattering. A complementary, molecular dynamics study has been performed on a range of phosphate glasses using density functional theory methods, which allow structural fluctuations, including bond breaking, in the liquid phase before quenching to the glass phase. Good agreement between experiment and simulation allows the molecular dynamics trajectories to be analysed in detail. In particular, attention is focused on the cross-linking of divalent cations in contrast with the structural aspects associated with monovalent cations. Magnesium cations are found equidistant and bridging between the phosphorus atoms of different phosphate chains, leading to a shorter phosphorus-phosphorus second neighbour distance (that is, a more compact packing of neighbouring phosphate chains) compared to the effect of sodium cations. Calcium cations show behaviour intermediate between those of magnesium and sodium. Molecular dynamics simulations give access to the cation mobility, which is lowest for magnesium, reflecting its structural, cross-linking role.

Early regulation of brain aromatase (cyp19a1b) by estrogen receptors during zebrafish development

Early expression of estrogen receptors (esr) and their role in regulating early expression of cyp19a1b encoding brain aromatase were examined in the brain of zebrafish. Using in toto hybridization and quantitative reverse transcriptase-polymerase chain reaction (RT-PCR), a significant increase in the expression of esr1, esr2a, and esr2b was observed between 24 and 48 hours postfertilization (hpf). In toto hybridization demonstrated that esr2a and esr2b, but not esr1, are found in the hypothalamus. Using real-time RT-PCR, an increase in cyp19a1b mRNAs occurs between 24 and 48 hpf, indicating that expression of cyp19a1b is temporally correlated with that of esr. This increase is blocked by the pure anti-estrogen ICI182,780. Furthermore, E2 treatment of cyp19a1b-GFP (green fluorescent protein) transgenic embryos results in appearance of GFP expression in the brain as early as 25 hpf. These results indicate that basal expression of cyp19a1b expression in the brain of developing zebrafish most likely relies upon expression of esr that are fully functional before 25 hpf.

Characterization and isolation of some genes of the shikimate pathway in sensitive and resistant Centaurea jacea plants after ozone exposure

Centaurea jacea has been suggested as a potential bioindicator for ozone, but little is known about its intraspecific variation in sensitivity, especially at molecular level. The effects of ozone (200 ppb, 5 h) on sensitive and resistant lines of Centaurea have been investigated at the end of fumigation. Sensitive plants showed characteristic symptoms of injury in the form of diffuse discoloration stipples on leaves. A PCR-based approach was used to identify and isolate a partial-length cDNA coding for PAL and CHS genes. The northern analysis of PAL showed accumulation of transcript in both lines correlated with a typical increase of PAL activity (+41 and +91% in resistant and sensitive material, respectively, compared to controls). On the contrary, the transcripts of CHS, in resistant and sensitive plants, did not change after treatment. Total phenols were not affected by ozone, while anthocyanins were quickly utilised by resistant clone as antioxidant compounds.

Half-life of the doubly magic r-process nucleus 78Ni

Nuclei with magic numbers serve as important benchmarks in nuclear theory. In addition, neutron-rich nuclei play an important role in the astrophysical rapid neutron-capture process (r process). 78Ni is the only doubly magic nucleus that is also an important waiting point in the r process, and serves as a major bottleneck in the synthesis of heavier elements. The half-life of 78Ni has been experimentally deduced for the first time at the Coupled Cyclotron Facility of the National Superconducting Cyclotron Laboratory at Michigan State University, and was found to be 110(+100)(-60) ms. In the same experiment, a first half-life was deduced for 77Ni of 128(+27)(-33) ms, and more precise half-lives were deduced for 75Ni and 76Ni of 344(+20)(-24) ms and 238(+15)(-18) ms, respectively.

Clawed toes deformity due to spasticity of the extensor digitorum muscle. A case report

Spasticity is a characteristic and early component of the lesions of the pyramidal tract of demyelinising diseases such as multiple sclerosis, and is included in the chief neurological scales to evaluate this disease. We report the case of a woman with a clawed toes deformity caused by spasticity of the extensor digitorum (longus and brevis) muscles.

SvpA, a novel surface virulence-associated protein required for intracellular survival of Listeria monocytogenes

A previously unknown protein, designated SvpA (surface virulence-associated protein) and implicated in the virulence of the intracellular pathogen Listeria monocytogenes, was identified. This 64 kDa protein, encoded by svpA, is both secreted in culture supernatants and surface-exposed, as shown by immunogold labelling of whole bacteria with an anti-SvpA antibody. Analysis of the peptide sequence revealed that SvpA contains a leader peptide, a predicted C-terminal transmembrane region and a positively charged tail resembling that of the surface protein ActA, suggesting that SvpA might partially reassociate with the bacterial surface by its C-terminal membrane anchor. An allelic mutant was constructed by disrupting svpA in the wild-type strain LO28. The virulence of this mutant was strongly attenuated in the mouse, with a 2 log decrease in the LD50 and restricted bacterial growth in organs as compared to the wild-type strain. This reduced virulence was not related either to a loss of adherence or to a lower expression of known virulence factors, which remained unaffected in the svpA mutant. It was caused by a restriction of intracellular growth of mutant bacteria. By following the intracellular behaviour of bacteria within bone-marrow-derived macrophages by confocal and electron microscopy studies, it was found that most svpA mutant bacteria remained confined within phagosomes, in contrast to wild-type bacteria which rapidly escaped to the cytoplasm. The regulation of svpA was independent of PrfA, the transcriptional activator of virulence genes in L. monocytogenes. In fact, SvpA was down-regulated by MecA, ClpC and ClpP, which are highly homologous to proteins of Bacillus subtilis forming a regulatory complex controlling the competence state of this saprophyte. The results indicate that: (i) SvpA is a novel factor involved in the virulence of L. monocytogenes, promoting bacterial escape from phagosomes of macrophages; (ii) SvpA is, at least partially, associated with the surface of bacteria; and (iii) SvpA is PrfA-independent and controlled by a MecA-dependent regulatory network.

Contribution of Mn-cofactored superoxide dismutase (SodA) to the virulence of Streptococcus agalactiae

Superoxide dismutases convert superoxide anions to molecular oxygen and hydrogen peroxide, which, in turn, is metabolized by catalases and/or peroxidases. These enzymes constitute one of the major defense mechanisms of cells against oxidative stress and hence play a role in the pathogenesis of certain bacteria. We previously demonstrated that group B streptococci (GBS) possess a single Mn-cofactored superoxide dismutase (SodA). To analyze the role of this enzyme in the pathogenicity of GBS, we constructed a sodA-disrupted mutant of Streptococcus agalactiae NEM316 by allelic exchange. This mutant was subsequently cis complemented by integration into the chromosome of pAT113/Sp harboring the wild-type sodA gene. The SOD specific activity detected by gel analysis in cell extracts confirmed that active SODs were present in the parental and complemented strains but absent in the sodA mutant. The growth rates of these strains in standing cultures were comparable, but the sodA mutant was extremely susceptible to the oxidative stress generated by addition of paraquat or hydrogen peroxide to the culture medium and exhibited a higher mutation frequency in the presence of rifampin. In mouse bone marrow-derived macrophages, the sodA mutant showed an increased susceptibility to bacterial killing by macrophages. In a mouse infection model, after intravenous injection the survival of the sodA mutant in the blood and the brain was markedly reduced in comparison to that of the parental and complemented strains whereas only minor effects on survival in the liver and the spleen were observed. These results suggest that SodA plays a role in GBS pathogenesis.

OppA of Listeria monocytogenes, an oligopeptide-binding protein required for bacterial growth at low temperature and involved in intracellular survival

We identified a new oligopeptide permease operon in the pathogen Listeria monocytogenes. This opp operon consists of five genes (oppA, oppB, oppC, oppD, and oppF) and displays the same genetic organization as those of several bacterial species. The first gene of this operon, oppA, encodes a 62-kDa protein sharing 33% identity with OppA of Bacillus subtilis and is expressed predominantly during exponential growth. The function of oppA was studied by constructing an oppA deletion mutant. The phenotype analysis of this mutant revealed that OppA mediates the transport of oligopeptides and is required for bacterial growth at low temperature. The wild-type phenotype was restored by complementing the mutant with oppA. We also found that OppA is involved in intracellular survival in macrophages and in bacterial growth in organs of mice infected with L. monocytogenes, although the level of virulence was not altered in the mutant. These results show the major role of OppA in the uptake of oligopeptides and the pleiotropic effects of this oligopeptide-binding protein on the behavior of this pathogen in the environment and in its host.

Optimization of green fluorescent protein expression vectors for in vitro and in vivo detection of Listeria monocytogenes

The green fluorescent protein (GFP) of the jellyfish Aequorea victoria is a useful reporter molecule for monitoring in vivo gene expression in eukaryotic and prokaryotic cells. We constructed a series of GFP vectors for in situ detection of the intracellular pathogen Listeria monocytogenes. The gfp-mutl gene, which encodes a red-shifted GFP, was transcriptionally fused to a strong L. monocytogenes promoter and inserted into various Escherichia coli-Listeria shuttle vectors: i) the integrative monocopy plasmid pAT113; ii) the low copy number plasmid pTCV-Exl; iii) the high copy number plasmid pAT18. Listeria cells harboring pNF6 and pNF7, constructed from pAT113 and pTCV-Exl, respectively, gave low fluorescence intensities, and were optically detected in cultured macrophages, but not in tissue sections. The fluorescence of Listeria with the pAT18 derivative pNF8 was about 40 times greater than that with pNF6 and 15 times greater than that with pNF7. Listeria cells harboring pNF8 were readily detected in both cultured macrophages and tissue sections. Constructed GFP vectors did not affect the virulence of L. monocytogenes in a murine model of infection.

Involvement of the Sst1 somatostatin receptor subtype in the intrahypothalamic neuronal network regulating growth hormone secretion: an in vitro and in vivo antisense study

Five somatostatin (SRIH) receptors (sst1-5) have been cloned. Recent anatomical evidence suggests that sst1 and sst2 may be involved in the central regulation of GH secretion. Given the lack of specific receptor antagonists, we used selective antisense oligodeoxynucleotides (ODNs) to test the hypothesis that one or both of these subtypes are involved in the intrahypothalamic network regulating pulsatile GH secretion. In mouse neuronal hypothalamic cultures the proportion of GHRH neurons coexpressing sst1 or sst2 messenger RNAs (mRNAs) was identical. In contrast, sst1 mRNAs were more often present than sst2 in SRIH-expressing neurons. Firstly, sst1 antisense ODN in vitro treatment abolished sst1, but not sst2, receptor modulation of glutamate sensitivity and decreased sst1, but not sst2, mRNAs. The reverse was true after treatment with sst2 antisense. Sense ODNs did not alter the effects of SRIH agonists. In a second series of experiments, nonanaesthetized adult male rats were infused for 120 h intracerebroventricularly with ODNs. Only the sst1 antisense ODN diminished the amplitude of ultradian GH pulses without modifying their frequency. In parallel, sst1 antisense ODN strongly diminished sst1 immunoreactivity in the anterior periventricular nucleus and median eminence, as well as sstl periventricular nucleus mRNA levels. The effectiveness of the sst2 antisense ODN was attested by the inhibition of hypothalamic binding of [125I]Tyr0-D-Trp8-SRIH. Scrambled ODNs had no effect on GH secretion or on sst mRNAs or SRIH binding levels. These results favor a preferential involvement of sst1 receptors in the intrahypothalamic regulation of GH secretion by SRIH.

The ClpP serine protease is essential for the intracellular parasitism and virulence of Listeria monocytogenes

We identified the stress-induced ClpP of Listeria monocytogenes and demonstrated its crucial role in intracellular survival of this pathogen. ClpP is a 21.6 kDa protein belonging to a family of proteases highly conserved in prokaryotes and eukaryotes. A clpP-deleted mutant enabled us to demonstrate that ClpP is involved in proteolysis and is required for growth under stress conditions. Intramacrophage survival of this mutant was strongly restricted, thus resulting in loss of virulence for the mouse. The activity of listeriolysin O, a major virulence factor implicated in bacterial escape from phagosomes of macrophages, was much reduced in the clpP mutant under stress conditions. Direct evidence for the role of ClpP in the intracellular parasitism was obtained by showing that virulence and haemolytic activity were fully restored by complementation of the mutant. These results suggest that ClpP is involved in the rapid adaptive response of intracellular pathogens during the infectious process.

Intrahypothalamic growth hormone feedback: from dwarfism to acromegaly in the rat

Two different dwarf rat models with primary (dw/dw, DW) or secondary (transgenic growth retarded, WF/Tgr) GH deficiency and contrasting hypothalamic GH-releasing hormone (GHRH) and somatostatin (SRIH) expression were implanted sc with GC cells. These form encapsulated rat GH-secreting tumors that maintain high plasma rat GH levels for several weeks. In both strains, GC cell tumors stimulated growth and raised GHBP levels, without affecting pituitary GH content. In DW rats, GC cell implants increased SRIH expression in the periventricular nucleus (PeV), but not in the arcuate nucleus (ARC), whereas their high GHRH expression in ARC was decreased by GC cells. In contrast, GC cell implants in WF/Tgr rats had little effect on the already high SRIH expression in PeV or low GHRH expression in ARC, although they reduced SRIH expression in ARC. GC cell implants also reduced GH receptor expression in both ARC and PeV in the WF/Tgr dwarves. Thus, chronic GH overexposure stimulates rapid growth in both dwarf strains, but has differential hypothalamic effects in these models. This experimental approach now makes it possible to study the effects of pathophysiological concentrations of GH ranging from dwarfism to acromegaly in the same animal model.

Continuous intracerebroventricular administration of a corticotropin releasing hormone antagonist amplifies spontaneous growth hormone pulses in the rat

Involvement of endogenous corticotropin releasing hormone (CRH) in the regulation of spontaneous growth hormone (GH) secretion was investigated. A CRH antagonist, alpha helical CRH 9-41, was intracerebroventricularly infused for 36 h at a rate of 1 microgram/0.5 microliter/h to freely moving, cannulated adult male rats. Serial blood samples were drawn every 20 min for the last 8 hours of alpha helical CRH 9-41 infusion. The treatment induced a marked increase in GH peak amplitude without affecting either trough levels or numbers of peaks. In parallel, levels of growth hormone releasing hormone (GHRH) mRNA in the arcuate nucleus, but not of somatotropin release inhibiting hormone (SRIH) mRNA in the periventricular and arcuate nuclei, were increased. These data suggest that, in addition to its action in the stress-induced inhibition of GH secretion through regulation of periventricular SRIH neurons, CRH can also act as a modulator of endogenous GH secretion through regulation of arcuate GHRH neurons. Whether the modulatory effects of CRH on GHRH neurons are direct or indirect remains to be established.

Central administration of a growth hormone (GH) receptor mRNA antisense increases GH pulsatility and decreases hypothalamic somatostatin expression in rats

To test the hypothesis of the involvement of centrally expressed rat growth hormone receptors (rGH-R) in the ultradian rhythmicity of pituitary GH secretion, adult male rats were submitted to a 60 hr intracerebroventricular infusion of an antisense (AS) oligodeoxynucleotide (ODN) complementary to the sequence of rGH-R mRNA. Eight hour (10 A.M.-6 P.M.) GH secretory profiles, obtained from freely moving male rats infused with 2.0 nmol/hr of rGH-R AS, revealed a marked increase in GH peak amplitude (150 +/- 12 vs 101 +/- 10 ng/ml), trough levels (16.2 +/- 3.0 vs 5.4 +/- 1.4 ng/ml), and number of peaks (2.9 +/- 0.3 vs 1.8 +/- 0.2). No change was observed in rats treated with an ODN complementary to the prolactin receptor mRNA sequence (2.0 nmol/hr). Infusion of increasing ODN concentrations resulted in a dose-dependent stimulation of GH release. In parallel, somatogenic binding sites in the choroid plexus were decreased by 40%, and levels of rGH-R mRNA were increased in the periventricular nucleus (PeV) but unchanged in the arcuate nucleus (ARC). Levels of somatostatin mRNA, in the PeV but not in the ARC, were lowered by the treatment. Levels of GH-releasing hormone mRNA in the ARC were not affected. These data suggest that GH negative feedback results from a direct effect on central GH receptors and a subsequent activation of hypophysiotropic somatostatin neurons located in the anterior periventricular hypothalamus.