238 research outputs found

    Victimization and PTSD-like states in an Icelandic youth probability sample

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    <p>Abstract</p> <p>Background</p> <p>Although adolescence in many cases is a period of rebellion and experimentation with new behaviors and roles, the exposure of adolescents to life-threatening and violent events has rarely been investigated in national probability studies using a broad range of events.</p> <p>Methods</p> <p>In an Icelandic national representative sample of 206 9th-grade students (mean = 14.5 years), the prevalence of 20 potentially traumatic events and negative life events was reported, along with the psychological impact of these events.</p> <p>Results</p> <p>Seventy-four percent of the girls and 79 percent of the boys were exposed to at least one event. The most common events were the death of a family member, threat of violence, and traffic accidents. The estimated lifetime prevalence of posttraumatic stress disorder-like states (PTSD; DSM-IV, APA, 1994 <abbrgrp><abbr bid="B1">1</abbr></abbrgrp>) was 16 percent, whereas another 12 percent reached a sub-clinical level of PTSD-like states (missing the full diagnosis with one symptom). Following exposure, girls suffered from PTSD-like states almost twice as often as boys. Gender, mothers' education, and single-parenthood were associated with specific events. The odds ratios and 95% CI for PTSD-like states given a specific event are reported. Being exposed to multiple potentially traumatic events was associated with an increase in PTSD-like states.</p> <p>Conclusion</p> <p>The findings indicate substantial mental health problems in adolescents that are associated with various types of potentially traumatic exposure.</p

    An extracellular steric seeding mechanism for Eph-ephrin signaling platform assembly

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    Erythropoetin-producing hepatoma (Eph) receptors are cell-surface protein tyrosine kinases mediating cell-cell communication. Upon activation, they form signaling clusters. We report crystal structures of the full ectodomain of human EphA2 (eEphA2) both alone and in complex with the receptor-binding domain of the ligand ephrinA5 (ephrinA5 RBD). Unliganded eEphA2 forms linear arrays of staggered parallel receptors involving two patches of residues conserved across A-class Ephs. eEphA2-ephrinA5 RBD forms a more elaborate assembly, whose interfaces include the same conserved regions on eEphA2, but rearranged to accommodate ephrinA5 RBD. Cell-surface expression of mutant EphA2s showed that these interfaces are critical for localization at cell-cell contacts and activation-dependent degradation. Our results suggest a 'nucleation' mechanism whereby a limited number of ligand-receptor interactions 'seed' an arrangement of receptors which can propagate into extended signaling arrays

    Pathway to Hope: an indigenous approach to healing child sexual abuse

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    Background. The Alaska Native (AN) population has endured multiple historical traumatic events. This population has poorer health outcomes on nearly all factors compared with Alaska non-Natives with more than 75% reportedly being physically assaulted in their lifetime, and child sexual abuse nearly 6 times the national average. Objective. This article describes the Pathway to Hope (PTH) program, which is an indigenous approach to ending silence and denial related to child sexual abuse and encourages multigenerational healing. Design. PTH was developed by ANs who believe that each community is unique, thus strategies for ending denial and support for healing must be woven from the historical context, cultural strengths of individual communities. Strengths-based solutions built on truth, honesty, compassion and shared responsibility for healing and protecting today&#x2019;s children have been profound and successful. The PTH curriculum addresses child sexual abuse from a historical perspective; that the higher rates of sexual abuse among certain Tribes, regions and communities is linked in part to years of victimisation, but may also be perpetuated by internalised oppression and lateral violence among Tribal members. Results. Data suggest that community-based dialogue and wisdom of Native elders and spiritual leaders paired with readiness of community service providers are necessary for sustained change. At all levels, this Indigenous model for learning, sharing, helping and healing brings hope for an end to denial and silence about child sexual abuse for Native people. Conclusions. The PTH program utilises the wisdom and values that have sustained Native people for generations. Ending silence and denial about child sexual abuse and building upon strengths have assisted many Indigenous communities begin the journey toward wellness. Through the PTH, communities have taken steps to accept the challenges associated with establishing safety for children, supporting child victims in healing and to holding offenders accountable

    Socio-demographic and behavioural characteristics of illegal motorcycle street racers in Malaysia

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    <p>Abstract</p> <p>Background</p> <p>This study sought to understand the factors associated with street racing among the illegal motorcycle racers in Malaysia or known as the <it>"Mat Rempit"</it>.</p> <p>Methods</p> <p>Street outreach interviewer-administered surveys were conducted from June 2008 to January 2009 in this multi-state study.</p> <p>Results</p> <p>A total of 2022 participants were surveyed, the mean ± <it>SD </it>age of the participants was 20.5 ± 3.4 years (age range: 12 to 35 years). Mean duration of street racing was 2.65(<it>SD </it>± 1.77) years (range: 2 months to 12 years), with 50.1% and 35.8% reporting stunt riding and alcohol drinking while racing, respectively. With regard to risk behaviours, cigarette smoking was highly prevalent among the study participants (78.3%), followed by alcohol drinking (27.8%) and recreational drug use (18.8%). Participants scored high on the masculinity scale (15.7 ± 4.0 out of 21.0). The results of the logistic regression analysis showed that socio-demographic variables, risk behaviour and masculinity scores were associated with racing frequency.</p> <p>Conclusion</p> <p>Given these associations, tailoring family-centered interventions to the needs of the lower socio-economic groups and interventions recognizing the negative consequences of health risk behaviours related to street racing as an expression of traditional masculinity should be emphasized.</p

    Design of Group IIA Secreted/Synovial Phospholipase A2 Inhibitors: An Oxadiazolone Derivative Suppresses Chondrocyte Prostaglandin E2 Secretion

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    Group IIA secreted/synovial phospholipase A2 (GIIAPLA2) is an enzyme involved in the synthesis of eicosanoids such as prostaglandin E2 (PGE2), the main eicosanoid contributing to pain and inflammation in rheumatic diseases. We designed, by molecular modeling, 7 novel analogs of 3-{4-[5(indol-1-yl)pentoxy]benzyl}-4H-1,2,4-oxadiazol-5-one, denoted C1, an inhibitor of the GIIAPLA2 enzyme. We report the results of molecular dynamics studies of the complexes between these derivatives and GIIAPLA2, along with their chemical synthesis and results from PLA2 inhibition tests. Modeling predicted some derivatives to display greater GIIAPLA2 affinities than did C1, and such predictions were confirmed by in vitro PLA2 enzymatic tests. Compound C8, endowed with the most favorable energy balance, was shown experimentally to be the strongest GIIAPLA2 inhibitor. Moreover, it displayed an anti-inflammatory activity on rabbit articular chondrocytes, as shown by its capacity to inhibit IL-1β-stimulated PGE2 secretion in these cells. Interestingly, it did not modify the COX-1 to COX-2 ratio. C8 is therefore a potential candidate for anti-inflammatory therapy in joints

    Adverse childhood experiences and mental health in young adults: a longitudinal survey

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    BACKGROUND: Adverse childhood experiences (ACEs) have been consistently linked to psychiatric difficulties in children and adults. However, the long-term effects of ACEs on mental health during the early adult years have been understudied. In addition, many studies are methodologically limited by use of non-representative samples, and few studies have investigated gender and racial differences. The current study relates self-reported lifetime exposure to a range of ACEs in a community sample of high school seniors to three mental health outcomes–depressive symptoms, drug abuse, and antisocial behavior–two years later during the transition to adulthood. METHODS: The study has a two-wave, prospective design. A systematic probability sample of high school seniors (N = 1093) was taken from communities of diverse socioeconomic status. They were interviewed in person in 1998 and over the telephone two years later. Gender and racial differences in ACE prevalence were tested with chi-square tests. Each mental health outcome was regressed on one ACE, controlling for gender, race/ethnicity, and SES to obtain partially standardized regression coefficients. RESULTS: Most ACEs were strongly associated with all three outcomes. The cumulative effect of ACEs was significant and of similar magnitude for all three outcomes. Except for sex abuse/assault, significant gender differences in the effects of single ACEs on depression and drug use were not observed. However, boys who experienced ACEs were more likely to engage in antisocial behavior early in young adulthood than girls who experienced similar ACEs. Where racial/ethnic differences existed, the adverse mental health impact of ACEs on Whites was consistently greater than on Blacks and Hispanics. CONCLUSION: Our sample of young adults from urban, socio-economically disadvantaged communities reported high rates of adverse childhood experiences. The public health impact of childhood adversity is evident in the very strong association between childhood adversity and depressive symptoms, antisocial behavior, and drug use during the early transition to adulthood. These findings, coupled with evidence that the impact of major childhood adversities persists well into adulthood, indicate the critical need for prevention and intervention strategies targeting early adverse experiences and their mental health consequences

    The Hexamer Structure of the Rift Valley Fever Virus Nucleoprotein Suggests a Mechanism for its Assembly into Ribonucleoprotein Complexes

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    Rift Valley fever virus (RVFV), a Phlebovirus with a genome consisting of three single-stranded RNA segments, is spread by infected mosquitoes and causes large viral outbreaks in Africa. RVFV encodes a nucleoprotein (N) that encapsidates the viral RNA. The N protein is the major component of the ribonucleoprotein complex and is also required for genomic RNA replication and transcription by the viral polymerase. Here we present the 1.6 Å crystal structure of the RVFV N protein in hexameric form. The ring-shaped hexamers form a functional RNA binding site, as assessed by mutagenesis experiments. Electron microscopy (EM) demonstrates that N in complex with RNA also forms rings in solution, and a single-particle EM reconstruction of a hexameric N-RNA complex is consistent with the crystallographic N hexamers. The ring-like organization of the hexamers in the crystal is stabilized by circular interactions of the N terminus of RVFV N, which forms an extended arm that binds to a hydrophobic pocket in the core domain of an adjacent subunit. The conformation of the N-terminal arm differs from that seen in a previous crystal structure of RVFV, in which it was bound to the hydrophobic pocket in its own core domain. The switch from an intra- to an inter-molecular interaction mode of the N-terminal arm may be a general principle that underlies multimerization and RNA encapsidation by N proteins from Bunyaviridae. Furthermore, slight structural adjustments of the N-terminal arm would allow RVFV N to form smaller or larger ring-shaped oligomers and potentially even a multimer with a super-helical subunit arrangement. Thus, the interaction mode between subunits seen in the crystal structure would allow the formation of filamentous ribonucleocapsids in vivo. Both the RNA binding cleft and the multimerization site of the N protein are promising targets for the development of antiviral drugs

    Subterranean, herbivore-induced plant volatile increases biological control activity of multiple beneficial nematode species in distinct habitats

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    While the role of herbivore-induced volatiles in plant-herbivore-natural enemy interactions is well documented aboveground, new evidence suggests that belowground volatile emissions can protect plants by attracting entomopathogenic nematodes (EPNs). However, due to methodological limitations, no study has previously detected belowground herbivore-induced volatiles in the field or quantified their impact on attraction of diverse EPN species. Here we show how a belowground herbivore-induced volatile can enhance mortality of agriculturally significant root pests. First, in real time, we identified pregeijerene (1,5-dimethylcyclodeca-1,5,7-triene) from citrus roots 9-12 hours after initiation of larval Diaprepes abbreviatus feeding. This compound was also detected in the root zone of mature citrus trees in the field. Application of collected volatiles from weevil-damaged citrus roots attracted native EPNs and increased mortality of beetle larvae (D. abbreviatus) compared to controls in a citrus orchard. In addition, field applications of isolated pregeijerene caused similar results. Quantitative real-time PCR revealed that pregeijerene increased pest mortality by attracting four species of naturally occurring EPNs in the field. Finally, we tested the generality of this root-zone signal by application of pregeijerene in blueberry fields; mortality of larvae (Galleria mellonella and Anomala orientalis) again increased by attracting naturally occurring populations of an EPN. Thus, this specific belowground signal attracts natural enemies of widespread root pests in distinct agricultural systems and may have broad potential in biological control of root pests.info:eu-repo/semantics/publishedVersio

    SAD phasing using iodide ions in a high-throughput structural genomics environment

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    The Seattle Structural Genomics Center for Infectious Disease (SSGCID) focuses on the structure elucidation of potential drug targets from class A, B, and C infectious disease organisms. Many SSGCID targets are selected because they have homologs in other organisms that are validated drug targets with known structures. Thus, many SSGCID targets are expected to be solved by molecular replacement (MR), and reflective of this, all proteins are expressed in native form. However, many community request targets do not have homologs with known structures and not all internally selected targets readily solve by MR, necessitating experimental phase determination. We have adopted the use of iodide ion soaks and single wavelength anomalous dispersion (SAD) experiments as our primary method for de novo phasing. This method uses existing native crystals and in house data collection, resulting in rapid, low cost structure determination. Iodide ions are non-toxic and soluble at molar concentrations, facilitating binding at numerous hydrophobic or positively charged sites. We have used this technique across a wide range of crystallization conditions with successful structure determination in 16 of 17 cases within the first year of use (94% success rate). Here we present a general overview of this method as well as several examples including SAD phasing of proteins with novel folds and the combined use of SAD and MR for targets with weak MR solutions. These cases highlight the straightforward and powerful method of iodide ion SAD phasing in a high-throughput structural genomics environment

    Inflammation-Associated Nitrotyrosination Affects TCR Recognition through Reduced Stability and Alteration of the Molecular Surface of the MHC Complex

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    Nitrotyrosination of proteins, a hallmark of inflammation, may result in the production of MHC-restricted neoantigens that can be recognized by T cells and bypass the constraints of immunological self-tolerance. Here we biochemically and structurally assessed how nitrotyrosination of the lymphocytic choriomeningitis virus (LCMV)-associated immunodominant MHC class I-restricted epitopes gp33 and gp34 alters T cell recognition in the context of both H-2Db and H-2Kb. Comparative analysis of the crystal structures of H-2Kb/gp34 and H-2Kb/NY-gp34 demonstrated that nitrotyrosination of p3Y in gp34 abrogates a hydrogen bond interaction formed with the H-2Kb residue E152. As a consequence the conformation of the TCR-interacting E152 was profoundly altered in H-2Kb/NY-gp34 when compared to H-2Kb/gp34, thereby modifying the surface of the nitrotyrosinated MHC complex. Furthermore, nitrotyrosination of gp34 resulted in structural over-packing, straining the overall conformation and considerably reducing the stability of the H-2Kb/NY-gp34 MHC complex when compared to H-2Kb/gp34. Our structural analysis also indicates that nitrotyrosination of the main TCR-interacting residue p4Y in gp33 abrogates recognition of H-2Db/gp33-NY complexes by H-2Db/gp33-specific T cells through sterical hindrance. In conclusion, this study provides the first structural and biochemical evidence for how MHC class I-restricted nitrotyrosinated neoantigens may enable viral escape and break immune tolerance
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