Project description:<p>The Genomic Predictors of Combat Stress Vulnerability and Resilience Study was designed to probe the likely hereditary basis for risk or resilience to develop PTSD and other trauma spectrum disorders. The overall guiding hypothesis was that genomic variation gives rise to risk/susceptibility traits that, when actuated by traumatic environmental stimuli, such as combat, give rise to PTSD and other stress-related phenotypes.</p> <p>Two studies designed to identify risk and resilience factors for combat-induced, stress-related symptoms are being conducted by our group: The Marine Resiliency Study (MRS) is a prospective PTSD study with longitudinal follow-up (pre- and post-exposure to combat stress) of US Marines bound for deployment to Iraq or Afghanistan. Extensive phenotyping includes 3 domains: Psychosocial, Psychophysiologic, and Biophysiologic. The biological and physiological measures collected were chosen in part due to their potential to serve as intermediate phenotypes for stress-related disorders. A second, cross-sectional study involves a cohort of combat-exposed active duty or previously deployed service members (CAVC), including PTSD cases and controls with comparable psychosocial and clinical phenotypes.</p> <p>Little information is available about the factors that explain why some trauma survivors develop stress disorders and some do not. It is hoped that the insights gained from this approach will improve understanding of the genetic contributors to PTSD, and potentially provide novel diagnostic tests and therapeutic approaches to this currently enigmatic and difficult-to-manage condition.</p>
Project description:Identification of blood biomarkers that prospectively predict progression of Mycobacterium tuberculosis infection to tuberculosis disease might lead to interventions that combat the tuberculosis epidemic. We aimed to assess whether global gene expression measured in whole blood of healthy people allowed identification of prospective signatures of risk of active tuberculosis disease. RESULTS:Between July 6, 2005, and April 23, 2007, we enrolled 6363 from the ACS study and 4466 from independent South African and Gambian cohorts. 46 progressors and 107 matched controls were identified in the ACS cohort. A 16 gene signature of risk was identified. The signature predicted tuberculosis progression with a sensitivity of 66·1% (95% CI 63·2â68·9) and a specificity of 80·6% (79·2â82·0) in the 12 months preceding tuberculosis diagnosis. The risk signature was validated in an untouched group of adolescents (p=0·018 for RNA sequencing and p=0·0095 for qRT-PCR) and in the independent South African and Gambian cohorts (p values <0·0001 by qRT-PCR) with a sensitivity of 53·7% (42·6â64·3) and a specificity of 82·8% (76·7â86) in 12 months preceding tuberculosis. Interpretation: The whole blood tuberculosis risk signature prospectively identified people at risk of developing active tuberculosis, opening the possibility for targeted intervention to prevent the disease. In this prospective cohort study, we followed up healthy, South African adolescents aged 12â18 years from the adolescent cohort study (ACS) who were infected with M tuberculosis for 2 years. We collected blood samples from study participants every 6 months and monitored the adolescents for progression to tuberculosis disease. A prospective signature of risk was derived from whole blood RNA sequencing data by comparing participants who developed active tuberculosis disease (progressors) with those who remained healthy (matched controls). After adaptation to multiplex qRT-PCR, the signature was used to predict tuberculosis disease in untouched adolescent samples and in samples from independent cohorts of South African and Gambian adult progressors and controls. Participants of the independent cohorts were household contacts of adults with active pulmonary tuberculosis disease.
Project description:BACKGROUND: Patients encountering severe trauma are at risk of developing sepsis syndrome and subsequent multiple organ failure. This is often associated with fatal outcome despite survival of the initial injury. We undertook a prospective cohort study of trauma patients to examine the role of tumor necrosis factor alpha (TNF-alpha) in the pathogenesis of sepsis syndrome and mortality. METHODS: 159 severely traumatized patients from a single centre were included. Serial blood samples were analyzed for serum concentrations of TNF-alpha and lymphotoxin alpha (LT-alpha). We genotyped nine polymorphisms in the TNF gene and tested for an association with sepsis syndrome and outcome. Genetic associations were validated in an external replication sample (n=76). We examined the peripheral blood transcriptome in n=28 patients by whole genome-based profiling and validated the results. RESULTS: Carriage of the TNF rs1800629 A allele was associated with higher TNF-alpha serum concentrations on the first day after trauma and during follow up (two-sided p=5.0x10-5), with development of sepsis syndrome (OR 7.14, two-sided p=1.2x10-6; external validation sample (n=76): OR 3.3, one-sided p=0.03), and with fatal outcome (OR 7.65, two-sided p=1.9x10-6). Carriage of the TNF rs1800629 A allele was associated with differential expression of genes representing stronger pro-inflammatory and apoptotic responses as compared to carriage of the wild type allele. CONCLUSIONS: Common TNF gene variants are associated with sepsis syndrome and death after severe injury. These findings are strongly supported by functional data and may be important for developing preemptive anti-inflammatory interventions in carriers of the risk-associated allele. Keywords: Disease state analysis
Project description:Objective: Posttraumatic stress disorder (PTSD) affects a high proportion of returning combat veterans, but the biological mechanisms of PTSD remain unclear. Circulating micro RNAs (miRNAs) have been associated with depression, and anxiety disorders, but there is little understanding of how miRNAs may relate to PTSD. In this study we compare profiles of circulating miRNA in combat veterans with and without PTSD in order to better understand biological mechanisms of PTSD. Methods: Blood from 24 male military service members was collected following deployment to Operation Iraqi Freedom (OIF) or Operation Enduring Freedom (OEF), and subjects were assessed for PTSD symptoms using the PTSD checklist-military version. miRNA was isolated from whole blood and sequenced on the Ion Torrent PGM™ using the Ion 316 Chip v2. Differences in miRNA expression was compared between subjects with PTSD (N=15) and combat matched controls without PTSD (N=9). Significantly different miRNA, according to a FDR≤0.05, were assessed for predictive putative targets, and pathway analysis of related targets was completed. Results: PTSD was associated with 4 upregulated and 4 downregulated miRNA, including a 2.94 fold increase in miR-19a-3p and a 1.56 fold decrease in miR-15b. Pathway analysis show that PTSD is related to the axon guidance and Wnt signaling pathways, which work together along with the adherens junction and MAPK signaling pathways to support neuronal development through regulation of growth cones. The PTSD associated miRNAs related to transcription factors, including Transcription factor 7 (T-cell specific, HMG-box), Transcription factor 7 like 1, and Transcription factor 7 like 2. Conclusions: PTSD is associated with miRNAs that regulate biological functions that include neuronal activities, suggesting that they play a role in PTSD symptomatology.
Project description:USA300 Staphylococcus aureus is responsible for the current outbreak of skin abscesses in the United States. Unlike other USA types, USA300 colonizes the rectum at rates higher than the nose. The reason for the difference in colonization site preference may be related to specific adherence or attachment factors contained in the genome of these strains. Additional knowledge in this field may help design novel prophylactic and therapeutic strategies to combat staphylococcal infections. Strains of USA300 MSSA and MRSA colonizing the nose and/or rectum from children with staphylococcal skin abscesses were compared by whole genome array technology to identify bacterial genetic determinants associated with site-specific colonization. Strains isolated from different colonization sites were indistinguishable by genomic content. Site-specific colonization traits were not detected in the colonizing bacteria by this array. Either host characteristics associated with staphylococcal carriage or under represented bacterial genomic constructions need to be examined to determine the etiology of this site-specific colonization. Data is also available from <ahref=http://bugs.sgul.ac.uk/E-BUGS-102 target=_blank>BuG@Sbase</a>