369 research outputs found

    Psychometric Properties of the German Version of the Child Post-Traumatic Cognitions Inventory (CPTCI-GER)

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    Dysfunctional trauma-related cognitions are associated with posttraumatic stress disorder (PTSD). The psychometric properties of the German version of the Child Post-Traumatic Cognitions Inventory (CPTCI-GER) were assessed in a sample of 223 children and adolescents (7–16 years) with a history of different traumatic events. Confirmatory factor analyses supported the original two-factor structure—permanent and disturbing change (CPTCI-PC) and fragile person in a scary world (CPTCI-SW). The total scale and both subscales showed good internal consistency. Participants with PTSD had significantly more dysfunctional trauma-related cognitions than those without PTSD. Dysfunctional posttraumatic cognitions correlated significantly with posttraumatic stress symptoms (PTSS; r = .62), depression (r = .71), and anxiety (r = .67). The CPTCI-GER has good psychometric properties and may facilitate evaluation of treatments and further research on the function of trauma-related cognitions in children and adolescents. (Partial) correlations provide empirical support for the combined DSM-5 symptom cluster negative alterations in cognitions and mood

    A model for the compressible, viscoelastic behavior of human amnion addressing tissue variability through a single parameter

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    A viscoelastic, compressible model is proposed to rationalize the recently reported response of human amnion in multiaxial relaxation and creep experiments. The theory includes two viscoelastic contributions responsible for the short- and long-term time- dependent response of the material. These two contributions can be related to physical processes: water flow through the tissue and dissipative characteristics of the collagen fibers, respectively. An accurate agreement of the model with the mean tension and kinematic response of amnion in uniaxial relaxation tests was achieved. By variation of a single linear factor that accounts for the variability among tissue samples, the model provides very sound predictions not only of the uniaxial relaxation but also of the uniaxial creep and strip-biaxial relaxation behavior of individual samples. This suggests that a wide range of viscoelastic behaviors due to patient-specific variations in tissue composition

    Children struggle beyond preschool-age in a continuous version of the ambiguous figures task

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    Children until the age of five are only able to reverse an ambiguous figure when they are informed about the second interpretation. In two experiments, we examined whether children’s difficulties would extend to a continuous version of the ambiguous figures task. Children (Experiment 1: 66 3- to 5-year olds; Experiment 2: 54 4- to 9-year olds) and adult controls saw line drawings of animals gradually morph—through well-known ambiguous figures—into other animals. Results show a relatively late developing ability to recognize the target animal, with difficulties extending beyond preschool-age. This delay can neither be explained with improvements in theory of mind, inhibitory control, nor individual differences in eye movements. Even the best achieving children only started to approach adult level performance at the age of 9, suggesting a fundamentally different processing style in children and adults

    Comparative Phylogeography in a Specific and Obligate Pollination Antagonism

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    In specific and obligate interactions the nature and abundance of a given species can have important effects on the survival and population dynamics of associated organisms. In a phylogeographic framework, we therefore expect that the fates of organisms interacting specifically are also tightly interrelated. Here we investigate such a scenario by analyzing the genetic structures of species interacting in an obligate plant-insect pollination lure-and-trap antagonism, involving Arum maculatum (Araceae) and its specific psychodid (Diptera) visitors Psychoda phalaenoides and Psycha grisescens. Because the interaction is asymmetric (i.e., only the plant depends on the insect), we expect the genetic structure of the plant to be related with the historical pollinator availability, yielding incongruent phylogeographic patterns between the interacting organisms

    Synapse Geometry and Receptor Dynamics Modulate Synaptic Strength

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    Synaptic transmission relies on several processes, such as the location of a released vesicle, the number and type of receptors, trafficking between the postsynaptic density (PSD) and extrasynaptic compartment, as well as the synapse organization. To study the impact of these parameters on excitatory synaptic transmission, we present a computational model for the fast AMPA-receptor mediated synaptic current. We show that in addition to the vesicular release probability, due to variations in their release locations and the AMPAR distribution, the postsynaptic current amplitude has a large variance, making a synapse an intrinsic unreliable device. We use our model to examine our experimental data recorded from CA1 mice hippocampal slices to study the differences between mEPSC and evoked EPSC variance. The synaptic current but not the coefficient of variation is maximal when the active zone where vesicles are released is apposed to the PSD. Moreover, we find that for certain type of synapses, receptor trafficking can affect the magnitude of synaptic depression. Finally, we demonstrate that perisynaptic microdomains located outside the PSD impacts synaptic transmission by regulating the number of desensitized receptors and their trafficking to the PSD. We conclude that geometrical modifications, reorganization of the PSD or perisynaptic microdomains modulate synaptic strength, as the mechanisms underlying long-term plasticity

    Attenuation of Toll-Like Receptor Expression and Function in Latent Tuberculosis by Coexistent Filarial Infection with Restoration Following Antifilarial Chemotherapy

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    Mycobacterium tuberculosis (Mtb) and filarial coinfection is highly prevalent, and the presence of filarial infections may regulate the Toll-like receptor (TLR)-dependent immune response needed to control Mtb infection. By analyzing the baseline and mycobacterial antigen–stimulated expression of TLR1, 2, 4, and 9 (in individuals with latent tuberculosis [TB] with or without filarial infection), we were able to demonstrate that filarial infection, coincident with Mtb, significantly diminishes both baseline and Mtb antigen-specific TLR2 and TLR9 expression. In addition, pro-inflammatory cytokine responses to TLR2 and 9 ligands are significantly diminished in filaria/TB-coinfected individuals. Definitive treatment of lymphatic filariasis significantly restores the pro-inflammatory cytokine responses in individuals with latent TB. Coincident filarial infection exerted a profound inhibitory effect on protective mycobacteria-specific TLR-mediated immune responses in latent tuberculosis and suggests a novel mechanism by which concomitant filarial infections predispose to the development of active tuberculosis in humans

    AMPA Receptor Activation Causes Silencing of AMPA Receptor-Mediated Synaptic Transmission in the Developing Hippocampus

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    Agonist-induced internalization of transmembrane receptors is a widespread biological phenomenon that also may serve as a mechanism for synaptic plasticity. Here we show that the agonist AMPA causes a depression of AMPA receptor (AMPAR) signaling at glutamate synapses in the CA1 region of the hippocampus in slices from developing, but not from mature, rats. This developmentally restricted agonist-induced synaptic depression is expressed as a total loss of AMPAR signaling, without affecting NMDA receptor (NMDAR) signaling, in a large proportion of the developing synapses, thus creating AMPAR silent synapses. The AMPA-induced AMPAR silencing is induced independently of activation of mGluRs and NMDARs, and it mimics and occludes stimulus-induced depression, suggesting that this latter form of synaptic plasticity is expressed as agonist-induced removal of AMPARs. Induction of long-term potentiation (LTP) rendered the developing synapses resistant to the AMPA-induced depression, indicating that LTP contributes to the maturation-related increased stability of these synapses. Our study shows that agonist binding to AMPARs is a sufficient triggering stimulus for the creation of AMPAR silent synapses at developing glutamate synapses

    Role of protein kinase C and epidermal growth factor receptor signalling in growth stimulation by neurotensin in colon carcinoma cells

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    <p>Abstract</p> <p>Background</p> <p>Neurotensin has been found to promote colon carcinogenesis in rats and mice, and proliferation of human colon carcinoma cell lines, but the mechanisms involved are not clear. We have examined signalling pathways activated by neurotensin in colorectal and pancreatic carcinoma cells.</p> <p>Methods</p> <p>Colon carcinoma cell lines HCT116 and HT29 and pancreatic adenocarcinoma cell line Panc-1 were cultured and stimulated with neurotensin or epidermal growth factor (EGF). DNA synthesis was determined by incorporation of radiolabelled thymidine into DNA. Levels and phosphorylation of proteins in signalling pathways were assessed by Western blotting.</p> <p>Results</p> <p>Neurotensin stimulated the phosphorylation of both extracellular signal-regulated kinase (ERK) and Akt in all three cell lines, but apparently did so through different pathways. In Panc-1 cells, neurotensin-induced phosphorylation of ERK, but not Akt, was dependent on protein kinase C (PKC), whereas an inhibitor of the β-isoform of phosphoinositide 3-kinase (PI3K), TGX221, abolished neurotensin-induced Akt phosphorylation in these cells, and there was no evidence of EGF receptor (EGFR) transactivation. In HT29 cells, in contrast, the EGFR tyrosine kinase inhibitor gefitinib blocked neurotensin-stimulated phosphorylation of both ERK and Akt, indicating transactivation of EGFR, independently of PKC. In HCT116 cells, neurotensin induced both a PKC-dependent phosphorylation of ERK and a metalloproteinase-mediated transactivation of EGFR that was associated with a gefitinib-sensitive phosphorylation of the downstream adaptor protein Shc. The activation of Akt was also inhibited by gefitinib, but only partly, suggesting a mechanism in addition to EGFR transactivation. Inhibition of PKC blocked neurotensin-induced DNA synthesis in HCT116 cells.</p> <p>Conclusions</p> <p>While acting predominantly through PKC in Panc-1 cells and via EGFR transactivation in HT29 cells, neurotensin used both these pathways in HCT116 cells. In these cells, neurotensin-induced activation of ERK and stimulation of DNA synthesis was PKC-dependent, whereas activation of the PI3K/Akt pathway was mediated by stimulation of metalloproteinases and subsequent transactivation of the EGFR. Thus, the data show that the signalling mechanisms mediating the effects of neurotensin involve multiple pathways and are cell-dependent.</p

    Rapid and bi-directional regulation of AMPA receptor phosphorylation and trafficking by JNK

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    Jun N-terminal kinases (JNKs) are implicated in various neuropathological conditions. However, physiological roles for JNKs in neurons remain largely unknown, despite the high expression level of JNKs in brain. Here, using bioinformatic and biochemical approaches, we identify the AMPA receptor GluR2L and GluR4 subunits as novel physiological JNK substrates in vitro, in heterologous cells and in neurons. Consistent with this finding, GluR2L and GluR4 associate with specific JNK signaling components in the brain. Moreover, the modulation of the novel JNK sites in GluR2L and GluR4 is dynamic and bi-directional, such that phosphorylation and de-phosphorylation are triggered within minutes following decreases and increases in neuronal activity, respectively. Using live-imaging techniques to address the functional consequence of these activity-dependent changes we demonstrate that the novel JNK site in GluR2L controls reinsertion of internalized GluR2L back to the cell surface following NMDA treatment, without affecting basal GluR2L trafficking. Taken together, our results demonstrate that JNK directly regulates AMPA-R trafficking following changes in neuronal activity in a rapid and bi-directional manner
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