745 research outputs found

    Neuropsychological evaluation of blast-related concussion: Illustrating the challenges and complexities through OEF/OIF case studies

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    Background/objective: Soldiers of Operations Enduring Freedom (OEF) and Iraqi Freedom (OIF) sustain blast-related mild traumatic brain injury (concussion) with alarming regularity. This study discusses factors in addition to concussion, such as co-morbid psychological difficulty (e.g. post-traumatic stress) and symptom validity concerns that may complicate neuropsychological evaluation in the late stage of concussive injury. Case report: The study presents the complexities that accompany neuropsychological evaluation of blast concussion through discussion of three case reports of OEF/OIF personnel. Discussion: The authors emphasize uniform assessment of blast concussion, the importance of determining concussion severity according to acute-injury characteristics and elaborate upon non-concussion-related factors that may impact course of cognitive limitation. The authors conclude with a discussion of the need for future research examining the impact of blast concussion (particularly recurrent concussion) and neuropsychological performance

    Evaluation Context Impacts Neuropsychological Performance of OEF/OIF Veterans with Reported Combat-Related Concussion

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    Although soldiers of Operations Iraqi Freedom (OIF) and Enduring Freedom (OEF) encounter combat-related concussion at an unprecedented rate, relatively few studies have examined how evaluation context, insufficient effort, and concussion history impact neuropsychological performances in the years following injury. The current study explores these issues in a sample of 119 U.S. veterans (OEF/OIF forensic concussion, n = 24; non-OEF/OIF forensic concussion, n = 20; OEF/OIF research concussion, n = 38; OEF/OIF research without concussion, n = 37). The OEF/OIF forensic concussion group exhibited significantly higher rates of insufficient effort relative to the OEF/OIF research concussion group, but a comparable rate of insufficient effort relative to the non-OEF/OIF forensic concussion group. After controlling for effort, the research concussion and the research non-concussion groups demonstrated comparable neuropsychological performance. Results highlight the importance of effort assessment among OEF/OIF and other veterans with concussion history, particularly in forensic contexts

    General anesthesia does not have persistent effects on attention in rodents

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    Background: Studies in animals have shown that general anesthesia can cause persistent spatial memory impairment, but the influence of anesthetics on other cognitive functions is unclear. This study tested whether exposure to general anesthesia without surgery caused a persistent deficit in attention in rodents.Methods: To evaluate whether anesthesia has persistent effects on attention, rats were randomized to three groups. Group A was exposed for 2 h to isoflurane anesthesia, and tested the following seven days for attentional deficits. Group B was used as a control and received room air before attentional testing. Since there is some evidence that a subanesthetic dose of ketamine can improve cognition and reduce disorders of attention after surgery, rats in group C were exposed to isoflurane anesthesia in combination with a ketamine injection before cognitive assessment. Attention was measured in rats using the 5-Choice Serial Reaction Time Task, for which animals were trained to respond with a nose poke on a touchscreen to a brief, unpredictable visual stimulus in one of five possible grid locations to receive a food reward. Attention was analyzed as % accuracy, % omission, and premature responses.Results: Evaluating acute attention by comparing baseline values with data from the day after intervention did not reveal any differences in attentional measurements. No significant differences were seen in % accuracy, % omission, and premature responses for the three groups tested for 7 consecutive days.Conclusion: These data in healthy rodents suggest that general anesthesia without surgery has no persistent effect on attention and the addition of ketamine does not alter the outcome

    Neuropsychological Outcomes of U.S. Veterans with Report of Remote Blast-Related Concussion and Current Psychopathology

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    This study explored whether remote blast-related MTBI and/or current Axis I psychopathology contribute to neuropsychological outcomes among OEF/OIF veterans with varied combat histories. OEF/OIF veterans underwent structured interviews to evaluate history of blast-related MTBI and psychopathology and were assigned to MTBI (n = 18), Axis I (n = 24), Co-morbid MTBI/Axis I (n = 34), or post-deployment control (n = 28) groups. A main effect for Axis I diagnosis on overall neuropsychological performance was identified (F(3,100) = 4.81; p = .004), with large effect sizes noted for the Axis I only (d = .98) and Co-morbid MTBI/Axis I (d = .95) groups relative to the control group. The latter groups demonstrated primary limitations on measures of learning/memory and processing speed. The MTBI only group demonstrated performances that were not significantly different from the remaining three groups. These findings suggest that a remote history of blast-related MTBI does not contribute to objective cognitive impairment in the late stage of injury. Impairments, when present, are subtle and most likely attributable to PTSD and other psychological conditions. Implications for clinical neuropsychologists and future research are discussed. (JINS, 2012, 18, 1–11

    Sun protection education for adolescents:a feasibility study of a wait-list controlled trial of an intervention involving a presentation, action planning, and SMS messages and using objective measurement of sun exposure

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    Background: People increase their risk of melanoma unless they are protected from the harmful effects of sun exposure during childhood and adolescence. We aimed to assess the feasibility of a three-component sun protection intervention-presentation, action planning, and SMS messages- A nd trial parameters. Methods: This feasibility wait-list trial was conducted in the United Kingdom in 2018. Students aged 13-15 years were eligible. Feasibility outcomes were collected for recruitment rates; data availability rates for objective measurements of melanin and erythema using a Mexameter and self-reported sunburn occurrences, severity and body location, tanning, sun protection behaviours and Skin Self-Examination (SSE) collected before (baseline) and after the school summer holidays (follow-up); intervention reach, adherence, perceived impact and acceptability. Quantitative data were analysed using descriptive statistics; qualitative data were analysed thematically. Results: Five out of eight schools expressing an interest in participating with four allocated to act as intervention and one control. Four parents/carers opted their child out of the study. Four hundred and eighty-seven out of 724 students on the school register consented to the study at baseline (67%). Three hundred and eighty-five were in intervention group schools. Objective skin measurements were available for 255 (66%) of the intervention group at baseline and 237 (61%) of the group at follow up. Melanin increased; erythema decreased. Complete self-report data were available for 247 (64%) students in the intervention group. The number of students on the school register who attended the presentation and given the booklet was 379 (98%) and gave their mobile phone number was 155 (40%). No intervention component was perceived as more impactful on sun protection behaviours. Adolescents did not see the relevance of sun protection in the UK or for their age group. Conclusions: This is the first study to use a Mexameter to measure skin colour in adolescents. Erythema (visible redness) lasts no more than three days and its measurement before and after a six week summer holiday may not yield relevant or meaningful data. A major challenge is that adolescents do not see the relevance of sun protection and SSE. Trial registration: International Standard Randomised Controlled Trial Number ISRCTN11141528. Date registered 0/2/03/2018; last edited 31/05/2018. Retrospectively registered.</p

    Sun protection education for adolescents:A feasibility study of a wait-list controlled trial of an intervention using objective measurement of sun exposure

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    Background People increase their risk of melanoma unless they are protected from the harmful effects of sun exposure during childhood and adolescence. We aimed to assess the feasibility of a three-component sun protection intervention- presentation, booklet, and text messages - and trial parameters. Methods This feasibility wait-list controlled trial was conducted in the United Kingdom in 2018. Students aged 13-15 years were eligible. Feasibility outcomes were collected for recruitment rates; data availability rates for objective measurements of melanin and erythema using a Mexameter and self-reported sunburn occurrences, severity and body location, tanning, sun protection behaviours and SSE collected before (baseline) and after the school summer holidays (follow-up); intervention reach, adherence, perceived impact and acceptability. Quantitative data were analysed using descriptive statistics; qualitative data were analysed thematically. Results Five out of eight schools expressing an interest in participating with four allocated to act as intervention and one control. Four parents/carers opted their child out of the study. 487 out of 724 students on the school register consented to the study at baseline (67%). 385 were in intervention group schools. Objective skin measurements were available for 255 (66%) of the intervention group at baseline and 237 (61%) of the group at follow up. Melanin increased; erythema decreased. Complete self-report data were available for 247 (64%) students in the intervention group. The number of students on the school register who attended the presentation and given the booklet was 379 (98%) and gave their mobile phone number was 155 (40%). No intervention component was perceived as more impactful on sun protection behaviours. Adolescents did not see the relevance of sun protection in the UK or for their age group. Conclusions This is the first study to use a Mexameter to measure skin colour in adolescents. Erythema (visible redness) lasts no more than three days and its measurement before and after a six week summer holiday may not yield relevant or meaningful data. A major challenge is that adolescents do not see the relevance of sun protection and SSE

    Chlamydia muridarum Genital and Gastrointestinal Infection Tropism Is Mediated by Distinct Chromosomal Factors

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    Some members of the genus Chlamydia, including the human pathogen Chlamydia trachomatis, infect multiple tissues, including the genital and gastrointestinal (GI) tracts. However, it is unknown if bacterial targeting to these sites is mediated by multifunctional or distinct chlamydial factors. We previously showed that disruption of individual large clostridial toxin homologs encoded within the Chlamydia muridarum plasticity zone were not critical for murine genital tract infection. Here, we assessed whether cytotoxin genes contribute to C. muridarum GI tropism. Infectivity and shedding of wild-type (WT) C. muridarum and three mutants containing nonsense mutations in different cytotoxin genes, tc0437, tc0438, and tc0439, were compared in mouse genital and GI infection models. One mutant, which had a nonsense mutation in tc0439, was highly attenuated for GI infection and had a GI 50% infectious dose (ID50) that was 1,000 times greater than that of the WT. GI inoculation with this mutant failed to elicit anti-chlamydial antibodies or to protect against subsequent genital tract infection. Genome sequencing of the tc0439 mutant revealed additional chromosomal mutations, and phenotyping of additional mutants suggested that the GI attenuation might be linked to a nonsense mutation in tc0600 The molecular mechanism underlying this dramatic difference in tissue-tropic virulence is not fully understood. However, isolation of these mutants demonstrates that distinct chlamydial chromosomal factors mediate chlamydial tissue tropism and provides a basis for vaccine initiatives to isolate chlamydia strains that are attenuated for genital infection but retain the ability to colonize the GI tract and elicit protective immune responses

    Pengembangan Instrumen Pendeteksi Kesulitan Belajar Kimia Kelas X Menggunakan Model Testlet

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    Penelitian ini bertujuan untuk: (1) menghasilkan instrumen model testlet sebagai instrumen pendeteksi kesulitan belajar kimia peserta didik kelas X SMA sesuai tahapan penelitian pengembangan; (2) menentukan karakteristik butir soal instrumen pendeteksi kesulitan belajar kimia kelas X menggunakan model testlet; (3) mendapatkan profil belajar individu peserta didik. Penelitian ini merupakan penelitian pengembangan model Akker dengan tahapan: preliminary investigation; theoretical embedding; empirical testing; dan documentation, analysis, and reflection on process and outcome. Subjek uji coba yaitu guru kimia SMA di Surakarta; dosen Pendidikan Kimia FKIP UNS Surakarta; peserta didik SMA Negeri 2, SMA Negeri 5, dan SMA Batik 2 Surakarta. Berdasarkan hasil penelitian dapat disimpulkan bahwa: (1) penelitian ini menghasilkan instrumen pendeteksi kesulitan belajar kimia kelas X menggunakan model testlet pada bab Struktur Atom dan Sistem Periodik Unsur yang terdiri dari butir soal dan program analisis datanya; (2) karakteristik butir soal memiliki validitas isi Aiken dengan rentang 0,76-1 yang berarti validitas isi baik; reliabilitas sebesar 0,83 yang berarti reliabilitas tinggi; persentase daya beda soal baik sekali 47,91%, baik 12,5%, cukup 18,75%, jelek 20,83%; persentase tingkat kesukaran soal sukar 4,17%, sedang 50%, mudah 45,83%; dan kunci jawaban 70,83% efektif; (3) profil belajar individu peserta didik dapat memberi laporan yang informatif mengenai kemampuan dan kesulitan belajar kimia peserta didik

    Quantification of the whole-body burden of radiographic osteoarthritis using factor analysis

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    INTRODUCTION: Although osteoarthritis (OA) commonly involves multiple joints, no widely accepted method for quantifying whole-body OA burden exists. Therefore, our aim was to apply factor analytic methods to radiographic OA (rOA) grades across multiple joint sites, representing both presence and severity, to quantify the burden of rOA. METHODS: We used cross-sectional data from the Johnston County Osteoarthritis Project. The sample (n = 2092) had a mean age of 65 ± 11 years, body mass index (BMI) 31 ± 7 kg/m2, with 33% men and 34% African Americans. A single expert reader (intra-rater κ = 0.89) provided radiographic grades based on standard atlases for the hands (30 joints, including bilateral distal and proximal interphalangeal [IP], thumb IP, metacarpophalangeal [MCP] and carpometacarpal [CMC] joints), knees (patellofemoral and tibiofemoral, 4 joints), hips (2 joints), and spine (5 levels [L1/2 to L5/S1]). All grades were entered into an exploratory common factor analysis as continuous variables. Stratified factor analyses were used to look for differences by gender, race, age, and cohort subgroups. RESULTS: Four factors were identified as follows: IP/CMC factor (20 joints), MCP factor (8 joints), Knee factor (4 joints), Spine factor (5 levels). These factors had high internal consistency reliability (Cronbach's α range 0.80 to 0.95), were not collapsible into a single factor, and had moderate between-factor correlations (Pearson correlation coefficient r = 0.24 to 0.44). There were no major differences in factor structure when stratified by subgroup. CONCLUSIONS: The 4 factors obtained in this analysis indicate that the variables contained within each factor share an underlying cause, but the 4 factors are distinct, suggesting that combining these joint sites into one overall measure is not appropriate. Using such factors to reflect multi-joint rOA in statistical models can reduce the number of variables needed and increase precision
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