1,762 research outputs found

    Neural correlates of enhanced visual short-term memory for angry faces: An fMRI study

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    Copyright: Š 2008 Jackson et al.Background: Fluid and effective social communication requires that both face identity and emotional expression information are encoded and maintained in visual short-term memory (VSTM) to enable a coherent, ongoing picture of the world and its players. This appears to be of particular evolutionary importance when confronted with potentially threatening displays of emotion - previous research has shown better VSTM for angry versus happy or neutral face identities.Methodology/Principal Findings: Using functional magnetic resonance imaging, here we investigated the neural correlates of this angry face benefit in VSTM. Participants were shown between one and four to-be-remembered angry, happy, or neutral faces, and after a short retention delay they stated whether a single probe face had been present or not in the previous display. All faces in any one display expressed the same emotion, and the task required memory for face identity. We find enhanced VSTM for angry face identities and describe the right hemisphere brain network underpinning this effect, which involves the globus pallidus, superior temporal sulcus, and frontal lobe. Increased activity in the globus pallidus was significantly correlated with the angry benefit in VSTM. Areas modulated by emotion were distinct from those modulated by memory load.Conclusions/Significance: Our results provide evidence for a key role of the basal ganglia as an interface between emotion and cognition, supported by a frontal, temporal, and occipital network.The authors were supported by a Wellcome Trust grant (grant number 077185/Z/05/Z) and by BBSRC (UK) grant BBS/B/16178

    The Effects of Overexpression of Histamine Releasing Factor (HRF) in a Transgenic Mouse Model

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    Asthma is a disease that affects all ages, races and ethnic groups. Its incidence is increasing both in Westernized countries and underdeveloped countries. It involves inflammation, genetics and environment and therefore, proteins that exacerbate the asthmatic, allergic phenotype are important. Our laboratory purified and cloned a histamine releasing factor (HRF) that was a complete stimulus for histamine and IL-4 secretion from a subpopulation of allergic donors' basophils. Throughout the course of studying HRF, it was uncovered that HRF enhances or primes histamine release and IL-13 production from all anti-IgE antibody stimulated basophils. In order to further delineate the biology of HRF, we generated a mouse model.We constructed an inducible transgenic mouse model with HRF targeted to lung epithelial cells, via the Clara cells. In antigen naĂŻve mice, overproduction of HRF yielded increases in BAL macrophages and statistical increases in mRNA levels for MCP-1 in the HRF transgenic mice compared to littermate controls. In addition to demonstrating intracellular HRF in the lung epithelial cells, we have also been able to document HRF's presence extracellularly in the BAL fluid of these transgenic mice. Furthermore, in the OVA challenged model, we show that HRF exacerbates the allergic, asthmatic responses. We found statistically significant increases in serum and BAL IgE, IL-4 protein and eosinophils in transgenic mice compared to controls.This mouse model demonstrates that HRF expression enhances allergic, asthmatic inflammation and can now be used as a tool to further dissect the biology of HRF

    Analysis of proliferative activity in oral gingival epithelium in immunosuppressive medication induced gingival overgrowth

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    BACKGROUND: Drug-induced gingival overgrowth is a frequent adverse effect associated principally with administration of the immunosuppressive drug cyclosporin A and also certain antiepileptic and antihypertensive drugs. It is characterized by a marked increase in the thickness of the epithelial layer and accumulation of excessive amounts of connective tissue. The mechanism by which the drugs cause gingival overgrowth is not yet understood. The purpose of this study was to compare proliferative activity of normal human gingiva and in cyclosporine A-induced gingival overgrowth. METHODS: Gingival samples were collected from 12 generally healthy individuals and 22 Cyclosporin A-medicated renal transplant recipients. Expression of proliferating cell nuclear antigen was evaluated in formalin-fixed, paraffin-embedded gingival samples using an immunoperoxidase technique and a monoclonal antibody for this antigen. RESULTS: There were differences between the Cyclosporin A group and control group in regard to proliferating cell nuclear antigen and epithelial thickness. In addition, the degree of stromal inflammation was higher in the Cyclosporin A group when compared with the control group. CONCLUSION: The results suggest that the increased epithelial thickness observed in Cyclosporin A-induced gingival overgrowth is associated with increased proliferative activity in keratinocytes

    A prospective clinical trial on the influence of a triamcinolone/demeclocycline and a calcium hydroxide based temporary cement on pain perception

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    <p>Abstract</p> <p>Introduction</p> <p>The aim of this clinical trial was to compare the degree of short term post-operative irritation after application of a triamcinolone/demeclocycyline based or a calcium hydroxide based provisional cement.</p> <p>Methods</p> <p>A total of 109 patients (55 female and 54 male; mean age: 51 Âą 14 years) with primary or secondary dentinal caries were randomly assigned to the two treatment groups of this biomedical clinical trial (phase III). Selection criteria were good systemic health and treated teeth, which were vital and showed no symptoms of pulpitis. Up to three teeth were prepared for indirect metallic restorations, and the provisional restorations were cemented with a triamcinolone/demeclocycyline (Ledermix) or a calcium hydroxide (Provicol) based material. The intensity of post-operative pain experienced was documented according to the VAS (4, 12, 20, 24, and 82 h) and compared to VAS baseline.</p> <p>Results</p> <p>A total of 159 teeth were treated (Ledermix: 83 teeth, Provicol: 76 teeth). The minor irritation of the teeth, experienced prior to treatment, was similar in both groups; however, 4 h after treatment this value was significantly higher in the Provicol group than in the Ledermix group (p < 0.005, t-test). After 12 h, the difference was no longer significant. The number of patients taking analgesics for post-treatment pain was higher in the Provicol group (n = 11/53) than in the Ledermix group (n = 3/56).</p> <p>Conclusions</p> <p>The patients had no long term post-operative pain experience in both groups. However, within the first hours after cementation the sensation of pain was considerably higher in the Provicol group than in the Ledermix group.</p

    A critical base pair in k-turns that confers folding characteristics and correlates with biological function

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    Kink turns (k-turns) are widespread elements in RNA that mediate tertiary contacts by kinking the helical axis. We have found that the ability of k-turns to undergo ion-induced folding is conferred by a single base pair that follows the conserved A·G pairs, that is, the 3b·3n position. A Watson–Crick pair leads to an inability to fold in metal ions alone, while 3n=G or 3b=C (but not both) permits folding. Crystallographic study reveals two hydrated metal ions coordinated to O6 of G3n and G2n of Kt-7. Removal of either atom impairs Mg(2+)-induced folding in solution. While SAM-I riboswitches have 3b·3n sequences that would predispose them to ion-induced folding, U4 snRNA are strongly biased to an inability to such folding. Thus riboswitch sequences allow folding to occur independently of protein binding, while U4 should remain unfolded until bound by protein. The empirical rules deduced for k-turn folding have strong predictive value

    Phase Shift from a Coral to a Corallimorph-Dominated Reef Associated with a Shipwreck on Palmyra Atoll

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    Coral reefs can undergo relatively rapid changes in the dominant biota, a phenomenon referred to as phase shift. Various reasons have been proposed to explain this phenomenon including increased human disturbance, pollution, or changes in coral reef biota that serve a major ecological function such as depletion of grazers. However, pinpointing the actual factors potentially responsible can be problematic. Here we show a phase shift from coral to the corallimorpharian Rhodactis howesii associated with a long line vessel that wrecked in 1991 on an isolated atoll (Palmyra) in the central Pacific Ocean. We documented high densities of R. howesii near the ship that progressively decreased with distance from the ship whereas R. howesii were rare to absent in other parts of the atoll. We also confirmed high densities of R. howesii around several buoys recently installed on the atoll in 2001. This is the first time that a phase shift on a coral reef has been unambiguously associated with man-made structures. This association was made, in part, because of the remoteness of Palmyra and its recent history of minimal human habitation or impact. Phase shifts can have long-term negative ramification for coral reefs, and eradication of organisms responsible for phase shifts in marine ecosystems can be difficult, particularly if such organisms cover a large area. The extensive R. howesii invasion and subsequent loss of coral reef habitat at Palmyra also highlights the importance of rapid removal of shipwrecks on corals reefs to mitigate the potential of reef overgrowth by invasives

    Performance of CMS muon reconstruction in pp collision events at sqrt(s) = 7 TeV

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    The performance of muon reconstruction, identification, and triggering in CMS has been studied using 40 inverse picobarns of data collected in pp collisions at sqrt(s) = 7 TeV at the LHC in 2010. A few benchmark sets of selection criteria covering a wide range of physics analysis needs have been examined. For all considered selections, the efficiency to reconstruct and identify a muon with a transverse momentum pT larger than a few GeV is above 95% over the whole region of pseudorapidity covered by the CMS muon system, abs(eta) < 2.4, while the probability to misidentify a hadron as a muon is well below 1%. The efficiency to trigger on single muons with pT above a few GeV is higher than 90% over the full eta range, and typically substantially better. The overall momentum scale is measured to a precision of 0.2% with muons from Z decays. The transverse momentum resolution varies from 1% to 6% depending on pseudorapidity for muons with pT below 100 GeV and, using cosmic rays, it is shown to be better than 10% in the central region up to pT = 1 TeV. Observed distributions of all quantities are well reproduced by the Monte Carlo simulation.Comment: Replaced with published version. Added journal reference and DO
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