The genetic architecture of the human cerebral cortex

The cerebral cortex underlies our complex cognitive capabilities, yet little is known about the specific genetic loci that influence human cortical structure. To identify genetic variants that affect cortical structure, we conducted a genome-wide association meta-analysis of brain magnetic resonance imaging data from 51,665 individuals. We analyzed the surface area and average thickness of the whole cortex and 34 regions with known functional specializations. We identified 199 significant loci and found significant enrichment for loci influencing total surface area within regulatory elements that are active during prenatal cortical development, supporting the radial unit hypothesis. Loci that affect regional surface area cluster near genes in Wnt signaling pathways, which influence progenitor expansion and areal identity. Variation in cortical structure is genetically correlated with cognitive function, Parkinson's disease, insomnia, depression, neuroticism, and attention deficit hyperactivity disorder.

International meta-analysis of PTSD genome-wide association studies identifies sex- and ancestry-specific genetic risk loci

The risk of posttraumatic stress disorder (PTSD) following trauma is heritable, but robust common variants have yet to be identified. In a multi-ethnic cohort including over 30,000 PTSD cases and 170,000 controls we conduct a genome-wide association study of PTSD. We demonstrate SNP-based heritability estimates of 5-20%, varying by sex. Three genome-wide significant loci are identified, 2 in European and 1 in African-ancestry analyses. Analyses stratified by sex implicate 3 additional loci in men. Along with other novel genes and non-coding RNAs, a Parkinson's disease gene involved in dopamine regulation, PARK2, is associated with PTSD. Finally, we demonstrate that polygenic risk for PTSD is significantly predictive of re-experiencing symptoms in the Million Veteran Program dataset, although specific loci did not replicate. These results demonstrate the role of genetic variation in the biology of risk for PTSD and highlight the necessity of conducting sex-stratified analyses and expanding GWAS beyond European ancestry populations.

Scavenging of nitrogen dioxide, thiyl, and sulfonyl free radicals by the nutritional antioxidant beta-carotene

Mechanisms of free radical scavenging by the nutritional antioxidant beta-carotene have been investigated by pulse radiolysis. Free radicals, which can initiate the chain of lipid peroxidation, including nitrogen dioxide (NO2.), thiyl (RS.), and sulfonyl (RSO2.) radicals, are rapidly scavenged by beta-carotene. Absolute rate constant k[NO2. + beta-carotene] = (1.1 +/- 0.1) x 10(8) m-1 s-1 and for the glutathione thiyl radical k[GS. + beta-carotene] = (2.2 +/- 0.1) x 10(8) m-1 s-1 have been determined. The mechanisms however are mutually exclusive, the former involving electron transfer to generate the radical-cation [ beta-carotene]+. and the latter by radical-addition to generate an adduct-radical [RS... beta-carotene].. Rate constants for thiyl radical-addition reactions vary from 10(6) to 10(9) m-1 s-1 and correlate with the lipophilicity of the thiyl radical under study. Sulfonyl radicals undergo both electron abstraction, [ beta-carotene]+. and radical-addition, [RSO2... beta-carotene]. in an approximate 3:1 ratio. The beta-carotene radical-cation and adduct-radicals are highly resonance stabilized and undergo slow bimolecular decay to non-radical products. These carotenoid-derived radicals react differently with oxygen, a factor which is expected to influence the antioxidant activity of beta-carotene within tissues of varying oxygen tension in vivo.

Autobiographical memory for stressful events: the role of autobiographical memory in posttraumatic stress disorder

To provide the three-way comparisons needed to test existing theories, we compared (1) most-stressful memories to other memories and (2) involuntary to voluntary memories (3) in 75 community dwelling adults with and 42 without a current diagnosis of posttraumatic stress disorder (PTSD). Each rated their three most-stressful, three most-positive, seven most-important and 15 word-cued autobiographical memories, and completed tests of personality and mood. Involuntary memories were then recorded and rated as they occurred for 2 weeks. Standard mechanisms of cognition and affect applied to extreme events accounted for the properties of stressful memories. Involuntary memories had greater emotional intensity than voluntary memories, but were not more frequently related to traumatic events. The emotional intensity, rehearsal, and centrality to the life story of both voluntary and involuntary memories, rather than incoherence of voluntary traumatic memories and enhanced availability of involuntary traumatic memories, were the properties of autobiographical memories associated with PTSD.

A Pilot Trial of Mindfulness Meditation Training for ADHD in Adulthood: Impact on Core Symptoms, Executive Functioning, and Emotion Dysregulation

OBJECTIVE

Mindfulness meditation training is garnering increasing empirical interest as an intervention for ADHD in adulthood, although no studies of mindfulness as a standalone treatment have included a sample composed entirely of adults with ADHD or a comparison group. The aim of this study was to assess the feasibility, acceptability, and preliminary efficacy of mindfulness meditation for ADHD, executive functioning (EF), and emotion dysregulation symptoms in an adult ADHD sample.

METHOD

Adults with ADHD were stratified by ADHD medication status and otherwise randomized into an 8-week group-based mindfulness treatment ( n = 11) or waitlist group ( n = 9).

RESULTS

Treatment feasibility and acceptability were positive. In addition, self-reported ADHD and EF symptoms (assessed in the laboratory and ecological momentary assessment), clinician ratings of ADHD and EF symptoms, and self-reported emotion dysregulation improved for the treatment group relative to the waitlist group over time with large effect sizes. Improvement was not observed for EF tasks.

CONCLUSION

Findings support preliminary treatment efficacy, though require larger trials.

Mobile contingency management as an adjunctive smoking cessation treatment for smokers with posttraumatic stress disorder

INTRODUCTION

Smokers with posttraumatic stress disorder (PTSD) smoke at higher prevalence rates and are more likely to relapse early in a quit attempt. Innovative methods are needed to enhance quit rates, particularly in the early quit period. Web-based contingency-management (CM) approaches have been found helpful in reducing smoking among other difficult-to-treat smoker populations but are limited by the need for computers. This pilot study builds on the web-based CM approach by evaluating a smartphone-based application for CM named mobile CM (mCM).

METHODS

Following a 2-week training period, 22 smokers with PTSD were randomized to a 4-week mCM condition or a yoked (i.e., noncontingent 4-week mCM condition). All smokers received 2 smoking cessation counseling sessions, nicotine replacement, and bupropion. Participants could earn up to $690 ($530 for mCM, $25.00 for assessments and office visits [up to 5], and $35.00 for equipment return). The average earned was $314.00.

RESULTS

Compliance was high during the 2-week training period (i.e., transmission of videos) (93%) and the 4-week treatment period (92%). Compliance rates did not differ by group assignment. Four-week quit rates (verified with CO) were 82% for the mCM and 45% for the yoked controls. Three-month self-report quit rates were 50% in the mCM and 18% in the yoked controls.

CONCLUSIONS

mCM may be a useful adjunctive smoking cessation treatment component for reducing smoking among smokers with PTSD, particularly early in a smoking quit attempt.

Exploration of the resilience construct in posttraumatic stress disorder severity and functional correlates in military combat veterans who have served since September 11, 2001

OBJECTIVE

This study evaluated the relationship between resilience and psychological functioning in military veterans deployed to a region of military conflict in support of Operation Enduring Freedom or Operation Iraqi Freedom.

METHOD

497 military veterans completed a structured psychiatric interview and questionnaires measuring psychological symptoms, resiliency, and trauma exposure. The study had 2 primary aims: (1) to examine whether the association between trauma exposure and PTSD was moderated by resilience and (2) to examine whether resilience was uniquely associated with functional outcomes after accounting for PTSD. Measures included the Structured Clinical Interview for DSM-IV-TR Axis I Disorders (for PTSD diagnosis), the Connor-Davidson Resilience Scale, and the Traumatic Life Events Questionnaire. Data were collected between June 2005 and February 2009.

RESULTS

Evaluating the association of resilience and trauma exposure with PTSD revealed main effects for combat exposure, lifetime trauma exposure, and resilience. Additionally, there was a significant (P < .05) interaction between combat exposure and resilience such that higher levels of resilience were particularly protective among individuals with high combat exposure. After controlling for age, gender, minority status, trauma exposure, and PTSD diagnosis, resilience was uniquely associated with decreased suicidality, reduced alcohol problems, lower depressive symptom severity, and fewer current health complaints and lifetime and past-year medical problems.

CONCLUSIONS

These results suggest that resilience is a construct that may play a unique role in the occurrence of PTSD and severity of other functional correlates among deployed veterans. Future studies in this area would benefit from a prospective design, the evaluation of other possible protective processes (e.g., social support), and specific examination of particular aspects of resilience and how resilience may be increased.

Nitric oxide in biological fluids: analysis of nitrite and nitrate by high-performance ion chromatography

The analysis of nitric oxide-derived nitrite and nitrate ions in biological fluids represents a proven strategy for determining nitric oxide participation in a diverse range of physiological and pathophysiological processes in vivo. In this article we describe a versatile method for the simultaneous measurement of NO2- and NO3- anions in both plasma and isolated tumour models based on anion-exchange chromatography with spectrophotometric detection (214 nm). This method compares well with the capillary electrophoresis technique, exhibiting an equivalent sensitivity for NO2-/NO3- anions and short run-times, i.e. not greater than 4 min. Comparisons are also made with two alternative but less satisfactory methods which employ ion-exchange or reversed-phase ion-pair chromatography with conductimetric as well as spectrophotometric detection. Technical problems associated with each method, particularly those arising from nitrate contamination, have been addressed.

Cellular uptake of misonidazole and analogues with acidic or basic functions

Average intracellular concentrations of five radiosensitizers in hamster fibroblast-like V79-379A cells in vitro were measured by high performance liquid chromatography, varying the extracellular pH (pHe) and estimating the apparent intracellular pH from the distribution of 5,5-dimethyloxazolidine-2,4-dione. The intracellular: extracellular concentration ratio for the 2-nitroimidazole, misonidazole was constant at about 0.7 for pHe = 6.6-7.6, whereas the weak base, Ro 03-8799 (1-(2-nitro-1-imidazolyl)-3-N-piperidino-2-propanol) was concentrated intracellularly at pHe = 7.3-7.4 by a factor of 3.3, the factor increasing from about 0.8 at pHe = 6.0, to 7.5 at pHe = 7.85. The weak acid, azomycin (2-nitroimidazole) showed approximately constant uptake (factor 1.1) between pHe = 6.0-7.0, decreasing to 0.8 at pHe = 7.3 and 0.4 at pHe = 7.8. Measurements of intracellular uptake of Ro 31-0052 (the more hydrophilic and less basic 3'-hydroxypiperidino analogue of Ro 03-8799) and of Ro 31-0258 (3-(2-nitro-1-imidazolyl)propionic acid, a stronger acid than azomycin) were made for comparison. The results were compared with theoretical calculations of pH-induced concentration gradients; the time dependence of the uptake of the bases is not at present clearly understood. These measurements of uptake are broadly consistent with the distribution of misonidazole and Ro 03-8799 in human and animal tissues and provide a useful insight into the likely intracellular concentrations in the clinical use of Ro 03-8799 or other basic radiosensitizers. The measurements also resolve the apparent discrepancy in radiosensitizer efficiency for weak bases in vitro and in vivo which has been previously noted.

Genome-wide association study of posttraumatic stress disorder in a cohort of Iraq-Afghanistan era veterans

BACKGROUND

Posttraumatic stress disorder (PTSD) is a psychiatric disorder that can develop after experiencing traumatic events. A genome-wide association study (GWAS) design was used to identify genetic risk factors for PTSD within a multi-racial sample primarily composed of U.S. veterans.

METHODS

Participants were recruited at multiple medical centers, and structured interviews were used to establish diagnoses. Genotypes were generated using three Illumina platforms and imputed with global reference data to create a common set of SNPs. SNPs that increased risk for PTSD were identified with logistic regression, while controlling for gender, trauma severity, and population substructure. Analyses were run separately in non-Hispanic black (NHB; n = 949) and non-Hispanic white (NHW; n = 759) participants. Meta-analysis was used to combine results from the two subsets.

RESULTS

SNPs within several interesting candidate genes were nominally significant. Within the NHB subset, the most significant genes were UNC13C and DSCAM. Within the NHW subset, the most significant genes were TBC1D2, SDC2 and PCDH7. In addition, PRKG1 and DDX60L were identified through meta-analysis. The top genes for the three analyses have been previously implicated in neurologic processes consistent with a role in PTSD. Pathway analysis of the top genes identified alternative splicing as the top GO term in all three analyses (FDR q < 3.5 × 10(-5)).

LIMITATIONS

No individual SNPs met genome-wide significance in the analyses.

CONCLUSIONS

This multi-racial PTSD GWAS identified biologically plausible candidate genes and suggests that post-transcriptional regulation may be important to the pathology of PTSD; however, replication of these findings is needed.

Objective evidence of sleep disturbance in women with posttraumatic stress disorder

Although sleep disturbance is considered a hallmark of posttraumatic stress disorder (PTSD), objective evidence for sleep disturbance in patients with PTSD has been equivocal. The goal of the current investigation was to objectively examine sleep disturbance among women with PTSD in their home environment. Women with PTSD (n = 30) and a control group (n = 22) completed three nights of actigraphy monitoring. Results from actigraphy indicated that women with PTSD had poorer sleep efficiency, increased sleep latency, and more restless sleep. Actigraphy measures were moderately correlated with self-report sleep-log data, but were unrelated to scores on the Pittsburgh Sleep Quality Index. The current study provides evidence that women with PTSD have objectively measured sleep disturbance in their normal environment at home. Disturbed sleep may have important implications for the health and well-being of individuals with PTSD.

Pharmacokinetics of nicotinamide and its effect on blood pressure, pulse and body temperature in normal human volunteers

The pharmacokinetics of nicotinamide were studied in four human volunteers after oral doses of 1-6 g. Plasma concentrations and clearance rates of the vitamin were found to be dose-dependent, with a half-life of approximately 7-9 h for the two highest doses administered (4 and 6 g), approximately 4 h with 2 g and approximately 1.5 h with a 1-g dose. Peak concentrations ranged from 0.7 to 1.1 mumol.ml-1 after a 6-g dose. The time to reach peak plasma concentration was dose independent with a broad range from 0.73 to 3 h. In this study, nicotinamide had no detectable effect on blood pressure, pulse or body temperature.

Indolequinone antitumor agents: reductive activation and elimination from (5-methoxy-1-methyl-4,7-dioxoindol-3-yl)methyl derivatives and hypoxia-selective cytotoxicity in vitro

A series of indolequinones bearing a variety of leaving groups at the (indol-3-yl)methyl position was synthesized by functionalization of the corresponding 3-(hydroxymethyl)indolequinone, and the resulting compounds were evaluated in vitro as bioreductively activated cytotoxins. The elimination of a range of functional groups-carboxylate, phenol, and thiol-was demonstrated upon reductive activation under both chemical and quantitative radiolytic conditions. Only those compounds which eliminated such groups under both sets of conditions exhibited significant hypoxia selectivity, with anoxic:oxic toxicity ratios in the range 10-200. With the exception of the 3-hydroxymethyl derivative, radiolytic generation of semiquinone radicals and HPLC analysis indicated that efficient elimination of the leaving group occurred following one-electron reduction of the parent compound. The active species in leaving group elimination was predominantly the hydroquinone rather than the semiquinone radical. The resulting iminium derivative acted as an alkylating agent and was efficiently trapped by added thiol following chemical reduction and by either water or 2-propanol following radiolytic reduction. A chain reaction in the radical-initiated reduction of these indolequinones (not seen in a simpler benzoquinone) in the presence of a hydrogen donor (2-propanol) was observed. Compounds that were unsubstituted at C-2 were found to be up to 300 times more potent as cytotoxins than their 2-alkyl-substituted analogues in V79-379A cells, but with lower hypoxic cytotoxicity ratios.

A placebo-controlled trial of bupropion SR in the treatment of chronic posttraumatic stress disorder

OBJECTIVE

Although selective serotonin reuptake inhibitors have been the most empirically studied pharmacotherapy for posttraumatic stress disorder (PTSD), a need remains for the investigation of additional pharmacological agents in the treatment of PTSD. The present study examined the use of bupropion sustained release (SR) as compared with placebo for symptom reduction in patients with PTSD: approximately half who were already prescribed an selective serotonin reuptake inhibitor and half who were not.

METHOD

Thirty patients (mean age, 50 years) with civilian- or military-related PTSD enrolled in an 8-week evaluation of bupropion SR versus placebo assigned in a 2:1 ratio in addition to their usual pharmacological care. Statistical tests included analyzing both study completers and using an intent-to-treat analysis, as well as post hoc examination of responders versus nonresponders.

RESULTS

Although no between-group differences were detected, both groups reported a reduction in PTSD symptoms. In a hypothesis-generating post hoc analysis of responders versus nonresponders in the bupropion SR condition (defined as a Clinician Global Improvement score of at least minimally improved), it seemed that younger patients not currently on another antidepressant were more likely to benefit from bupropion.

CONCLUSIONS

Bupropion SR in the treatment of PTSD had no significant effect in the current sample. Factors contributing to the absence of an effect need further study. Our analysis points to the inclusion of age and concomitant antidepressant treatment as important variables in any future larger-scale study.

Predictors of lapse in first week of smoking abstinence in PTSD and non-PTSD smokers

INTRODUCTION

Retrospective research suggests smokers with posttraumatic stress disorder (PTSD) lapse more quickly after their quit date. Ecological momentary assessment (EMA) research is needed to confirm the presence of early smoking lapse in PTSD and form conceptualizations that inform intervention.

METHODS

Smokers with (n = 55) and without (n = 52) PTSD completed alarm-prompted EMA of situational and psychiatric variables the week before and after a quit date, and self-initiated EMA following smoking lapses. Blood samples at baseline and on the quit date allowed assessment of dehydroepiandrosterone (DHEA) and dehydroepiandrosterone sulfate (DHEA(S)).

RESULTS

PTSD was related to shorter time to lapse (hazard ratio [HR] = 1.677, 95% CI: 1.106-2.544). Increased smoking abstinence self-efficacy was related to longer time to lapse (HR = 0.608, 95% CI: 0.430-0.860). Analyses of participants' real-time reports revealed that smokers with PTSD were more likely to attribute first-time lapses to negative affect ( = 5.412, p = .020), and trauma reminders (Fisher's exact p = .003**). Finally, the quit date decrease in DHEA(S) was related to shorter time to lapse (HR = 1.009, 95% CI: 1.000-1.018, p < .05).

CONCLUSIONS

Results provide evidence of shorter time to first smoking lapse in PTSD, and add to evidence that early lapse occasions are more strongly related to trauma reminders, negative affect, and cravings in smokers with PTSD.

The effects of cigarette smoking on script-driven imagery in smokers with and without posttraumatic stress disorder

The study investigated the effects of smoking a nicotinized or denicotinized cigarette on craving, affect and posttraumatic stress disorder (PTSD) symptoms while recalling neutral, stressful and traumatic events in smokers with and without PTSD. Smokers completed laboratory sessions during which they were presented with audiotapes of personalized scripts followed by smoking a cigarette. The effect of the script and cigarette conditions on dependent variables was evaluated. There was a main effect of script type across groups for smoking craving, negative affect and PTSD symptoms, with increased symptoms in trauma and stressful conditions. Responses were significantly higher in PTSD smokers. Smoking either cigarette type resulted in decreased craving, negative affect and PTSD symptoms in both groups. A second script presentation following smoking elicited similar responses, suggesting the ameliorative effect of having smoked a cigarette was short-lived. These results support that context and non-pharmacologic effects of smoking are important variables in smoking craving and mood, particularly in smokers with PTSD.

Multicomponent smoking cessation treatment including mobile contingency management in homeless veterans

INTRODUCTION

Smoking rates are 80% among persons who are homeless, and these smokers have decreased odds of quitting smoking. Little is known about relapse rates among homeless smokers. More information is needed regarding both quit rates and innovative methods to treat smoking cessation among homeless smokers. Web-based contingency management (CM) approaches have been found helpful in reducing smoking among other difficult-to-treat smoker populations but have been generally limited by the need for computers or frequent clinic-based carbon monoxide (CO) monitoring. This open pilot study builds on a web-based CM approach by evaluating a smartphone-based application for CM named mobile CM (mCM). The study was conducted from January 1, 2013-April 15, 2014.

METHOD

Following a 1-week training period, 20 homeless veteran smokers (≥ 10 cigarettes daily for 1 year or more and a CO baseline level ≥ 10 ppm) participated in a multicomponent smoking cessation intervention including 4 weeks of mCM. All smokers received 4 smoking cessation counseling sessions, nicotine replacement, and bupropion (if medically eligible). Participants could earn up to $815 ($480 for mCM, $100 for CO readings showing abstinence [ie, 6 ppm or less] at posttreatment and follow-up, and $35 for equipment return).

RESULTS

Mean compensation for the mCM component was $286 of a possible $480. Video transmission compliance was high during the 1-week training (97%) and the 4-week treatment period (87%). Bioverified 7-day point prevalence abstinence was 50% at 4 weeks. Follow-up bioverified single assessment point prevalence abstinence was 55% at 3 months and 45% at 6 months.

CONCLUSIONS

Results of this open pilot study suggest that mCM may be a useful adjunctive smoking cessation treatment component for reducing smoking among homeless veterans.

TRIAL REGISTRATION

ClinicalTrials.gov identifier: NCT01789710.

Self-mutilative behaviors in male veterans with posttraumatic stress disorder

Self-mutilative behaviors (SMB) were examined in a sample of male veterans with posttraumatic stress disorder (PTSD). The primary objective was to determine the prevalence of SMB and any physical, cognitive, or affective antecedents and correlates for these behaviors. Participants included 509 male veterans with PTSD and levels of PTSD, depression, alcohol use, hostility, and impulsivity were evaluated to determine if these variables were related to SMB. Antecedents and sequelae of SMB were also examined to generate hypotheses regarding the functions of these behaviors. A second type of habit behavior, body-focused repetitive behaviors (BFRB), was also examined as part of the study. Findings indicated that veterans who engaged in either type of habit behavior were younger than those who did not engage in SMB or BFRB. Veterans reporting SMB also reported higher levels of PTSD, depression, hostility, and impulsivity compared to the BFRB and no-habit groups. Examination of habit antecedents and sequelae showed support for the automatic-positive reinforcement function of SMB. These findings are discussed in the context of research and treatment involving male veterans with PTSD who engage in SMB.

High-performance liquid chromatographic determination of nicotinamide and its metabolites in human and murine plasma and urine

A high-performance liquid chromatographic method is described which enables the determination of nicotinamide and eight of its possible metabolites in human and murine plasma and urine, using ion-pairing on a base-deactivated reversed-phase column. Calibration curves were linear up to 2 mumol/ml for nicotinamide and 200 nmol/ml for the metabolites; both the intra- and inter-assay relative standard deviations ranged between 1 and 8%. In murine plasma, the N-oxide was the major nicotinamide metabolite, but in man, formation of 1-methylnicotinamide and the 2- and 4-pyridones was also significant. In urine, nicotinuric acid was seen in the mouse, but no nicotinic acid metabolites were seen in man.

Smoking in help-seeking veterans with PTSD returning from Afghanistan and Iraq

Past research has shown that veterans and individuals with posttraumatic stress disorder (PTSD) have increased rates of smoking. However, the rates of smoking in younger help-seeking veterans returning from Afghanistan and Iraq, and possible correlates of smoking among this population are unknown. In this study, we evaluated the rate of lifetime and current smoking among a sample of 90 returning male veterans diagnosed with PTSD. Fifty-nine percent reported a lifetime history of smoking including 32% that were current smokers. Current smokers were significantly younger than non-smokers. Current smokers (mean age=31) reported a mean age of smoking onset as 15.86 with a pack year history of 8.89. These smokers reported on average five previous quit attempts. According to a stages of change model, one-half of the smokers were in the contemplation phase of stopping smoking (50%), 29% were in the pre-contemplation phase and 21% were in the preparation phase. The results are placed in the context of non-psychiatric and psychiatric smokers.

Radicals from one-electron reduction of nitro compounds, aromatic N-oxides and quinones: the kinetic basis for hypoxia-selective, bioreductive drugs

Drugs based on nitroarene, aromatic N-oxide or quinone structures are frequently reduced by cellular reductases to toxic products. Reduction often involves free radicals as intermediates which react rapidly with oxygen to form superoxide radicals, inhibiting drug reduction. The elevation of cellular oxidative stress accompanying oxygen inhibition of reduction is generally less damaging than drug reduction to toxic products, so the drugs offer selective toxicity to hypoxic cells. Since such cells are resistant to radiotherapy, these bioreductive drugs offer potential in tumour therapy. The basis for the selectivity of action entails kinetic competition involving the contesting reaction pathways. The reduction potential of the drug, radical pKa and nature of radical/radical decay kinetics all influence drug activity and selectivity, including the range of oxygen tensions over which the drug offers selective toxicity. These properties may be quantified using generation of radicals by pulse radiolysis, presenting a physicochemical basis for rational drug design.

Exploration of the influence of childhood trauma, combat exposure, and the resilience construct on depression and suicidal ideation among U.S. Iraq/Afghanistan era military personnel and veterans

This study evaluated the effect of childhood trauma exposure and the role of resilience on both depressive symptoms and suicidal ideation. The study evaluated 1,488 military personnel and veterans, who served after September 2001, for depressive, suicidal, and PTSD symptoms, combat exposure, childhood trauma exposure, and resiliency. Participants were enrolled as part of an ongoing multicenter study. Outcome measures were depressive symptoms and suicidal ideation. After controlling for the effects of combat exposure and PTSD, results revealed that childhood trauma exposures were significantly associated with depressive symptoms and suicidal ideation. In addition, resilience was negatively associated with depressive symptoms and suicidal ideation, suggesting a potential protective effect. These findings suggest that evaluation of childhood trauma is important in the clinical assessment and treatment of depressive symptoms and suicidal ideation among military personnel and veterans.

The effect of draft DSM-V criteria on posttraumatic stress disorder prevalence

BACKGROUND

This study was designed to examine the concordance of proposed DSM-V posttraumatic stress disorder (PTSD) criteria with DSM-IV classification rules and examine the impact of the proposed DSM-V PTSD criteria on prevalence.

METHOD

The sample (N = 185) included participants who were recruited for studies focused on trauma and health conducted at an academic medical center and VA medical center in the southeastern United States. The prevalence and concordance between DSM-IV and the proposed DSM-V classifications were calculated based on results from structured clinical interviews. Prevalence rates and diagnostic efficiency indices including sensitivity, specificity, area under the curve (AUC), and Kappa were calculated for each of the possible ways to define DSM-V PTSD.

RESULTS

Ninety-five percent of the sample reported an event that met both DSM-IV PTSD Criterion A1 and A2, but only 89% reported a trauma that met Criterion A on DSM-V. Results examining concordance between DSM-IV and DSM-V algorithms indicated that several of the algorithms had AUCs above 0.90. The requirement of two symptoms from both Clusters D and E provided strong concordance to DSM-IV (AUC = 0.93; Kappa = 0.86) and a greater balance between sensitivity and specificity than requiring three symptoms in both Clusters D and E.

CONCLUSIONS

Despite several significant changes to the diagnostic criteria for PTSD for DSM-V, several possible classification rules provided good concordance with DSM-IV. The magnitude of the impact of DSM-V decision rules on prevalence will be largely affected by the DSM-IV PTSD base rate in the population of interest.

Peroxidase-catalyzed effects of indole-3-acetic acid and analogues on lipid membranes, DNA, and mammalian cells in vitro

This study aimed to explore the mechanisms and molecular parameters which control the cytotoxicity of derivatives of indole-3-acetic acid (IAA) when oxidatively activated by horseradish peroxidase (HRP). Lipid peroxidation was measured in liposomes, damage to supercoiled plasmid DNA assessed by gel electrophoresis, free radical intermediates detected by EPR following spin trapping, binding of IAA-derived products demonstrated by 3H labelling, stable products measured by HPLC, and cytotoxicity in hamster fibroblasts measured by clonogenic survival. IAA, and nine analogues more easily oxidized by HRP, caused lipid peroxidation in liposomes, but not detectably in membranes of hamster fibroblasts, and were cytotoxic after HRP activation to varying degrees. Cytotoxicity was not correlated with activation rate. The hydrophilic vitamin E analogue, Trolox, inhibited cytotoxicity, whereas loading fibroblasts with vitamin E was ineffective, consistent with an oxidative mechanism in which radical precursors to damage are intercepted by Trolox in the aqueous phase. However, two known oxidation products were nontoxic (the 3-carbinol and 3-aldehyde, both probably produced from 3-CH2OO* peroxyl radicals via the 3-CH*2 [skatolyl] radical following decarboxylation of the radical cation). The skatolyl radical from IAA was shown by EPR with spin trapping to react with DNA; electrophoresis showed binding to occur. Treatment of hamster fibroblasts with 5-3H-IAA/HRP resulted in intracellular bound 3H. Together with earlier results, the new data point to unknown electrophilic oxidation products, reactive towards intracellular targets, being involved in cytotoxicity of the IAA/HRP combination, rather than direct attack of free radicals, excited states, or membrane lipid peroxidation.

A genome-wide association study of suicide attempts in the million veterans program identifies evidence of pan-ancestry and ancestry-specific risk loci

To identify pan-ancestry and ancestry-specific loci associated with attempting suicide among veterans, we conducted a genome-wide association study (GWAS) of suicide attempts within a large, multi-ancestry cohort of U.S. veterans enrolled in the Million Veterans Program (MVP). Cases were defined as veterans with a documented history of suicide attempts in the electronic health record (EHR; N = 14,089) and controls were defined as veterans with no documented history of suicidal thoughts or behaviors in the EHR (N = 395,064). GWAS was performed separately in each ancestry group, controlling for sex, age and genetic substructure. Pan-ancestry risk loci were identified through meta-analysis and included two genome-wide significant loci on chromosomes 20 (p = 3.64 × 10-9) and 1 (p = 3.69 × 10-8). A strong pan-ancestry signal at the Dopamine Receptor D2 locus (p = 1.77 × 10-7) was also identified and subsequently replicated in a large, independent international civilian cohort (p = 7.97 × 10-4). Additionally, ancestry-specific genome-wide significant loci were also detected in African-Americans, European-Americans, Asian-Americans, and Hispanic-Americans. Pathway analyses suggested over-representation of many biological pathways with high clinical significance, including oxytocin signaling, glutamatergic synapse, cortisol synthesis and secretion, dopaminergic synapse, and circadian rhythm. These findings confirm that the genetic architecture underlying suicide attempt risk is complex and includes both pan-ancestry and ancestry-specific risk loci. Moreover, pathway analyses suggested many commonly impacted biological pathways that could inform development of improved therapeutics for suicide prevention.