Phosphatidylinositol 4,5-bisphosphate clusters act as molecular beacons for vesicle recruitment.

Synaptic-vesicle exocytosis is mediated by the vesicular Ca(2+) sensor synaptotagmin-1. Synaptotagmin-1 interacts with the SNARE protein syntaxin-1A and acidic phospholipids such as phosphatidylinositol 4,5-bisphosphate (PIP2). However, it is unclear how these interactions contribute to triggering membrane fusion. Using PC12 cells from Rattus norvegicus and artificial supported bilayers, we show that synaptotagmin-1 interacts with the polybasic linker region of syntaxin-1A independent of Ca(2+) through PIP2. This interaction allows both Ca(2+)-binding sites of synaptotagmin-1 to bind to phosphatidylserine in the vesicle membrane upon Ca(2+) triggering. We determined the crystal structure of the C2B domain of synaptotagmin-1 bound to phosphoserine, allowing development of a high-resolution model of synaptotagmin bridging two different membranes. Our results suggest that PIP2 clusters organized by syntaxin-1 act as molecular beacons for vesicle docking, with the subsequent Ca(2+) influx bringing the vesicle membrane close enough for membrane fusion.

Liquid line of descent of a basanitic liquid at 1.5 GPa: Constraints for metasomatic vein formation

The metasomatism observed in the oceanic and continental lithosphere is generally interpreted to represent a continuous differentiation process forming anhydrous and hydrous veins plus a cryptic enrichment in the surrounding peridotite. In order to constrain the mechanisms of vein formation and potentially clarify the nature and origin of the initial metasomatic agent, we performed a series of high-pressure experiments simulating the liquid line of descent of a basanitic magma differentiating within continental or mature oceanic lithosphere. This series of experiments has been conducted in an end-loaded piston cylinder apparatus starting from an initial hydrous ne-normative basanite at 1.5 GPa and temperature varying between 1,250 and 980°C. Near-pure fractional crystallization process was achieved in a stepwise manner in 30°C temperature steps and starting compositions corresponding to the liquid composition of the previous, higher-temperature glass composition. Liquids evolve progressively from basanite to peralkaline, aluminum-rich compositions without significant SiO2 variation. The resulting cumulates are characterized by an anhydrous clinopyroxene + olivine assemblage at high temperature (1,250-1,160°C), while at lower temperature (1,130-980°C), hydrous cumulates with dominantly amphibole + minor clinopyroxene, spinel, ilmenite, titanomagnetite and apatite (1,130-980°C) are formed. This new data set supports the interpretation that anhydrous and hydrous metasomatic veins could be produced during continuous differentiation processes of primary, hydrous alkaline magmas at high pressure. However, the comparison between the cumulates generated by the fractional crystallization from an initial ne-normative liquid or from hy-normative initial compositions (hawaiite or picrobasalt) indicates that for all hydrous liquids, the different phases formed upon differentiation are mostly similar even though the proportions of hydrous versus anhydrous minerals could vary significantly. This suggests that the formation of amphibole-bearing metasomatic veins observed in the lithospheric mantle could be linked to the differentiation of initial liquids ranging from ne-normative to hy-normative in composition. The present study does not resolve the question whether the metasomatism observed in lithospheric mantle is a precursor or a consequence of alkaline magmatism; however, it confirms that the percolation and differentiation of a liquid produced by a low degree of partial melting of a source similar or slightly more enriched than depleted MORB mantle could generate hydrous metasomatic veins interpreted as a potential source for alkaline magmatism by various authors.

5-HT2A and alpha1b-adrenergic receptors entirely mediate dopamine release, locomotor response and behavioural sensitization to opiates and psychostimulants.

Addictive properties of drugs of misuse are generally considered to be mediated by an increased release of dopamine (DA) in the ventral striatum. However, recent experiments indicated an implication of alpha1b-adrenergic receptors in behavioural responses to psychostimulants and opiates. We show now that DA release induced in the ventral striatum by morphine (20 mg/kg) is completely blocked by prazosin (1 mg/kg), an alpha1-adrenergic antagonist. However, morphine-induced increases in DA release in the ventral striatum were found to be similar in mice deleted for the alpha1b-adrenergic receptor (alpha1b-AR KO) and in wild-type (WT) mice, suggesting the presence of a compensatory mechanism. This acute morphine-evoked DA release was completely blocked in alpha1b-AR KO mice by SR46349B (1 mg/kg), a 5-HT2A antagonist. SR46349B also completely blocked, in alpha1b-AR KO mice, the locomotor response and the development of behavioural sensitization to morphine (20 mg/kg) and D-amphetamine (2 mg/kg). Accordingly, the concomitant blockade of 5-HT2A and alpha1b-adrenergic receptors in WT mice entirely blocked acute locomotor responses but also the development of behavioural sensitization to morphine, D-amphetamine or cocaine (10 mg/kg). We observed, nevertheless, that inhibitory effects of each antagonist on locomotor responses to morphine or D-amphetamine were more than additive (160%) in naïve WT mice but not in those sensitized to either drug. Because of these latter data and the possible compensation by 5-HT2A receptors for the genetic deletion of alpha1b-adrenergic receptors, we postulate the existence of a functional link between these receptors, which vanishes during the development of behavioural sensitization.

Plasma levels of the enantiomers of thioridazine, thioridazine 2-sulfoxide, thioridazine 2-sulfone, and thioridazine 5-sulfoxide in poor and extensive metabolizers of dextromethorphan and mephenytoin.

Concentrations of total (R) + (S) and of the enantiomers (R) and (S) of thioridazine and metabolites were measured in 21 patients who were receiving 100 mg thioridazine for 14 days and who were comedicated with moclobemide (450 mg/day). Two patients were poor metabolizers of dextromethorphan and one was a poor metabolizer of mephenytoin. Cytochrome P450IID6 (CYP2D6) is involved in the formation of thioridazine 2-sulfoxide (2-SO) from thioridazine and also probably partially in the formation of thioridazine 5-sulfoxide (5-SO), but not in the formation of thioridazine 2-sulfone (2-SO2) from thioridazine 2-SO. Significant correlations between the mephenytoin enantiomeric ratio and concentrations of thioridazine and metabolites suggest that cytochrome P450IIC19 could contribute to the biotransformation of thioridazine into yet-unknown metabolites, other than thioridazine 2-SO, thioridazine 2-SO2, or thioridazine 5-SO. An enantioselectivity and a large interindividual variability in the metabolism of thioridazine have been shown: measured (R)/(S) ratios of thioridazine, thioridazine 2-SO fast eluting (FE), thioridazine 2-SO slow eluting (SE), thioridazine 2-SO (FE+SE), thioridazine 2-SO2, thioridazine 5-SO(FE), and thioridazine 5-SO(SE) were (mean +/- SD) 3.48 +/- 0 .93 (range, 2.30 to 5.80), 0.45 +/- 0.22 (range, 0.21 to 1.20), 2.27 +/- 8.1 (range, 6.1 to 40.1), 4.64 +/- 0.68 (range, 2.85 to 5.70), 3.26 +/- 0.58 (range, 2.30 to 4.30), 0.049 +/- 0.019 (range, (0.021 to 0.087), and 67.2 +/- 66.2 (range, 16.8 to 248), respectively. CYP2D6 is apparently involved in the formation of (S)-thioridazine 2-SO(FE), (R)-thioridazine 2-SO(SE), and also probably (S)-thioridazine 5-SO(FE) and (R)-thioridazine 5-SO(SE).

Higher memory responses in HIV-infected and kidney transplanted patients than in healthy subjects following priming with the pandemic vaccine.

BACKGROUND: Memory responses require immune competence. We assessed the influence of priming with AS03-adjuvanted pandemic vaccine (Pandemrix®) on memory responses of HIV patients, kidney recipients (SOT) and healthy controls (HC). METHOD: Participants (HIV: 197, SOT: 53; HC: 156) were enrolled in a prospective study and 390/406 (96%) completed it. All had been primed in 2009/2010 with 1 (HC) or 2 (patients) doses of Pandemrix®, and were boosted with the 2010/2011 seasonal influenza vaccine. Geometric mean titres and seroprotection rates were measured 12 months after priming and 4 weeks after boosting. Primary and memory responses were directly compared in 191 participants (HCW: 69, HIV: 71, SOT: 51) followed during 2 consecutive seasons. RESULTS: Most participants (HC: 77.8%, HIV: 77.6%, SOT: 66%) remained seroprotected at 12 months post-priming. Persisting A/09/H1N1 titers were high in HIV (100.2) and HC (120.1), but lower in SOT (61.4) patients. Memory responses reached higher titers in HIV (507.8) than in HC (253.5) and SOT (136.9) patients. Increasing age and lack of HAART reduced persisting and memory responses, mainly influenced by residual antibody titers. Comparing 2009/2010 and 2010/2011 titers in 191 participants followed for 2 seasons indicated lower post-2010/2011 titers in HC (240.2 vs 313.9), but higher titers in HIV (435.7 vs 338.0) and SOT (136 vs 90.3) patients. CONCLUSIONS: Priming with 2 doses of Pandemrix® elicited persistent antibody responses and even stronger memory responses to non-adjuvanted seasonal vaccine in HIV patients than 1 dose in healthy subjects. Adjuvanted influenza vaccines may improve memory responses of immunocompromised patients. TRIAL REGISTRATION: ClinicalTrials.gov NCT01022905.

Determination of 13C/12C ratios of endogenous urinary 5-amino-imidazole-4-carboxamide 1-D-ribofuranoside (AICAR)

RATIONALE: AICAR (5-aminoimidazole-4-carboxamide 1β-D-ribofuranoside) is prohibited in sport according to rules established by the World Anti-Doping Agency. Doping control laboratories identify samples where AICAR abuse is suspected by measuring its urinary concentration and comparing the observed level with naturally occurring concentrations. As the inter-individual variance of urinary AICAR concentrations is large, this approach requires a complementary method to unambiguously prove the exogenous origin of AICAR. Therefore, a method for the determination of carbon isotope ratios (CIRs) of urinary AICAR has been developed and validated. METHODS: Concentrated urine samples were fractionated by means of liquid chromatography for analyte cleanup. Derivatization of AICAR yielding the trimethylsilylated analog was necessary to enable CIR determinations by gas chromatography/combustion/isotope ratio mass spectrometry. The method was tested for its repeatability and stability over time and a linear mixing model was applied to test for possible isotopic discrimination. A reference population of n = 63 males and females was investigated to calculate appropriate reference limits to differentiate endogenous from exogenous urinary AICAR. These limits were tested by an AICAR elimination study. RESULTS: The developed method fulfills all the requirements for adequate sports drug testing and was found to be fit for purpose. The investigated reference population showed a larger variability in the CIR of AICAR than of the endogenous steroids. Nevertheless, the calculated thresholds for differences between AICAR and endogenous steroids can be applied straightforwardly to evaluate suspicious doping control samples with the same statistical confidence as established e.g. for testosterone misuse. These thresholds enabled the detection of a single oral AICAR administration for more than 40 h. CONCLUSIONS: Determination of thee CIRs is the method of choice to distinguish between an endogenous and an exogenous source of urinary AICAR. The developed method will enable investigations into doping control samples with elevated urinary concentrations of AICAR and clearly differentiate between naturally produced/elevated and illicitly administered AICAR.

Subclinical hypothyroidism and the risk of heart failure, other cardiovascular events, and death.

BACKGROUND: Subclinical hypothyroidism has been associated with systolic and diastolic cardiac dysfunction and an elevated cholesterol level, but data on cardiovascular outcomes and death are limited. METHODS: We studied 2730 men and women, aged 70 to 79 years, with baseline thyrotropin (TSH) measurements and 4-year follow-up data to determine whether subclinical hypothyroidism was associated with congestive heart failure (CHF), coronary heart disease, stroke, peripheral arterial disease, and cardiovascular-related and total mortality. After the exclusion of participants with abnormal thyroxine levels, subclinical hypothyroidism was defined as a TSH level of 4.5 mIU/L or greater, and was further classified according to TSH levels (4.5-6.9, 7.0-9.9, and > or = 10.0 mIU/L). RESULTS: Subclinical hypothyroidism was present in 338 (12.4%) of the participants. Compared with euthyroid participants, CHF events occurred more frequently among those with a TSH level of 7.0 mIU/L or greater (35.0 vs 16.5 per 1000 person-years; P = .006), but not among those with TSH levels between 4.5 and 6.9 mIU/L. In multivariate analyses, the risk of CHF was higher among those with high TSH levels (TSH of 7.0-9.9 mIU/L: hazard ratio, 2.58 [95% confidence interval, 1.19-5.60]; and TSH of > or = 10.0 mIU/L: hazard ratio, 3.26 [95% confidence interval, 1.37-7.77]). Among the 2555 participants without CHF at baseline, the hazard ratio for incident CHF events was 2.33 (95% confidence interval, 1.10-4.96; P = .03) in those with a TSH of 7.0 mIU/L or greater. Subclinical hypothyroidism was not associated with increased risk for coronary heart disease, stroke, peripheral arterial disease, or cardiovascular-related or total mortality. CONCLUSIONS: Subclinical hypothyroidism is associated with an increased risk of CHF among older adults with a TSH level of 7.0 mIU/L or greater, but not with other cardiovascular events and mortality. Further investigation is warranted to assess whether subclinical hypothyroidism causes or worsens preexisting heart failure.

La parola raccontata dai cavalieri-narratori nella "Continuation du Roman de Meliadus" (ms. Ferrell 5)

Copiato nell'Italia del Nord verso il 1350, il manoscritto Ferrell 5 è oggi il solo testimone della "Continuation du Roman de Meliadus" che racconta le avventure di Artù, di Meliadus il padre di Tristano, e del Buon Cavaliere senza Paura padre di Dinadan, partiti alla ricerca di Morholt, prigioniero su di un'isola lontana. Ora, questa inchiesta è solo un pretesto: al centro dell'interesse dei tre re non sta tanto l'avventura promessa quanto i racconti che essi collezionano in occasione dei diversi scali di questo viaggio per mare, durante il quale non succede quasi niente. La ricerca di Morholt agisce quale racconto-cornice che non solo mette in scena le condizioni della presa di parola da parte dei cavalieri-narratori e organizza i racconti, anzi li drammatizza, ma funziona anche da matrice che informa, feconda e rigenera questi stessi racconti. Quanto all'isolamento, imposto dalla navigazione, esso permette lo sbocciare di una piccola ma prestigiosa società di narratori che non ha nulla da invidiare a quella delle raccolte di novelle. Così, un racconto dopo l'altro, si definisce un'arte di narrare che espone ed esplora i legami tra valore del racconto e bontà della cavalleria: la perfezione poetica, fonte del piacere estetico, è solo l'altra faccia della perfezione cavalleresca.

5

Musculoskeletal disorders (MSD) are the most prevalent pain disorders in industrialized countries, and their costs can represent up to 2% of gross national product. MSD are often work associated and recurrent and may lead to disability. In occupational health we are interested in the opposite process : in the return to work (RTW). Different models of disability and RTW exist with different conceptions of psychosocial factors. We therefore propose to analyze the influence of factors from work, patient, health care providers, and broader societal domains along the different phases of the MSD process, adopting a biopsychosocial approach. The analysis of risk factors for the different phases of MSD indicate that work stress factors have an impact on the occurrence of MSD and RTW with MSD, but their effect is low to moderate and nonspecific. Physical work demands, work place adaptation, and pain experience are much stronger predictors of RTW. Lack of modified or adapted work is one of the major factors that hinder RTW. The longer the pain lasts, the longer the patient is out of work, the more personal factors and broader context factors become dominant. There is a clear lack of RTW studies concerning neck and upper limb pain. MSD and especially chronic MSD should be viewed as public health concerns, implying a wider socio-economic and insurance and disability problem. Adequate medical support tailored to the different dimensions and phases of MSD must be on offer, and work accommodations must be promoted and supported.

The gap between scientific evidence and clinical practice : 5-aminosalicylates are frequently used for the treatment of Crohn's disease

BACKGROUND: There is uncertain evidence of effectiveness of 5-aminosalicylates (5-ASA) to induce and maintain response and remission of active Crohn's disease (CD), and weak evidence to support their use in post-operative CD. AIM: To assess the frequency and determinants of 5-ASA use in CD patients and to evaluate the physicians' perception of clinical response and side effects to 5-ASA. METHODS: Data from the Swiss Inflammatory Bowel Disease Cohort, which collects data since 2006 on a large sample of IBD patients, were analysed. Information from questionnaires regarding utilisation of treatments and perception of response to 5-ASA were evaluated. Logistic regression modelling was performed to identify factors associated with 5-ASA use. RESULTS: Of 1420 CD patients, 835 (59%) were ever treated with 5-ASA from diagnosis to latest follow-up. Disease duration >10 years and colonic location were both significantly associated with 5-ASA use. 5-ASA treatment was judged to be successful in 46% (378/825) of treatment episodes (physician global assessment). Side effects prompting stop of therapy were found in 12% (98/825) episodes in which 5-ASA had been stopped. CONCLUSIONS: 5-Aminosalicylates were frequently prescribed in patients with Crohn's disease in the Swiss IBD cohort. This observation stands in contrast to the scientific evidence demonstrating a very limited role of 5-ASA compounds in the treatment of Crohn's disease.