The effects of a dual orexin receptor antagonist on fear extinction memory and sleep in mice: Implications for exposure therapy

Extinction of conditioned fear is considered a fundamental process in the recovery from posttraumatic stress disorder and anxiety disorders. Sleep, especially rapid-eye-movement (REM) sleep, has been implicated in promoting extinction memory. The orexin system contributes to the regulation of sleep and wakefulness and emotional behaviors. In rodents, administrations of an orexin receptor antagonist following fear extinction training enhanced consolidation of extinction memory. Although orexin antagonists increase sleep, including REM sleep, the possible contribution of sleep to the effects of orexin antagonists on extinction memory has not been examined. Therefore, this study examined the effects of suvorexant, a dual orexin receptor antagonist, on extinction memory and sleep and their associations in mice. C57BL/6 mice underwent sleep recording for 24 h before and after contextual fear conditioning with footshocks and extinction learning during the early light phase or early dark phase. Mice were systemically injected with either 25 mg/kg of suvorexant or vehicle immediately after the extinction session. We found that suvorexant neither altered sleep nor improved extinction memory recall compared with vehicle. The higher percentages of REM sleep during the post-extinction dark phase were associated with lower extinction memory recall and greater freezing responses to the fear context. Results also indicate that animals did not reach complete extinction of fear with the fear extinction training protocol used in this study. These findings suggest that promoting REM sleep may not enhance fear extinction memory when extinction of fear is incomplete.

Evaluation of suvorexant for trauma-related insomnia

STUDY OBJECTIVES

Effective pharmacological treatments for sleep disturbance related to trauma with and without co-occurring posttraumatic stress disorder (PTSD) are needed. There is debate regarding what effects on rapid eye movement sleep (REMS) would be beneficial. Suvorexant is the first dual orexin receptor antagonist (DORA) approved for the treatment of insomnia. In contrast to most psychotropic agents, DORAs can enhance REMS while reducing arousal. We evaluated 6 weeks of suvorexant treatment for trauma-related insomnia in a double-blind, placebo-controlled clinical trial with clinical and polysomnographic evaluation.

METHODS

Participants with insomnia that followed a traumatic event were recruited from the community. Representation of current, past-only, and never having met criteria for PTSD was similar and most participants had experienced trauma-related nightmares. Participants were randomly assigned to receive suvorexant or placebo, initially at 10 mg and increased to 20 mg after 1 week, if tolerated. Polysomnography was obtained for screening, at baseline, and at 2 weeks of treatment.

RESULTS

The thirty-seven evaluable participants had significant improvement of PTSD and insomnia symptoms, however, there were no significant interactions with treatment condition. Medication was well tolerated with only one dropout being related to side effects. Within the suvorexant group increased REM segment duration correlated with concurrent PTSD symptom reduction. Nightmares remitted in all of the participants who received suvorexant and all but one of those receiving placebo.

CONCLUSIONS

A robust placebo response undermined detecting a medication effect. Further evaluation of DORAs for trauma-related insomnia, as well as factors contributing to placebo-response, are warranted.

Blocking the orexin system following therapeutic exposure promoted between session habituation, but not PTSD symptom reduction

There is a need to identify strategies to increase the effectiveness of treatments for posttraumatic stress disorder (PTSD). Sleep is often disturbed in PTSD and has been implicated in learning processes that underlie recovery from PTSD, including extinction of conditioned fear. Our prior study suggested that diminished arousal during sleep may enhance benefits of therapeutic exposure for PTSD. The orexin system regulates arousal, and blocking the system diminishes arousal and promotes sleep. We, therefore, examined whether a dual orexin receptor antagonist, suvorexant, administered following evening exposure sessions, would enhance their therapeutic effectiveness for PTSD. In this randomized double-blind placebo-controlled trial, adults with PTSD completed four written narrative exposure (WNE) sessions, two of which took place in the evening, and two the next morning. Participants received either suvorexant or placebo after each evening WNE. We found that suvorexant increased N3 sleep and decreased N2 sleep and rapid-eye-movement latency measured by polysomnography. Between session habituation indexed by subjective distress ratings was greater with suvorexant, but there was no group difference in the reduction of PTSD severity from baseline to 1-week follow-up. No safety concerns emerged. The present findings provide preliminary support for enhancement of an effect of therapeutic exposure for PTSD by suvorexant. Further studies with larger samples are needed to translate the present findings into clinical applications, including studies to develop optimal suvorexant administration and exposure session schedules to achieve persistent benefits to sleep and possibly greater treatment augmentation.

736 Evaluation of suvorexant for trauma-related insomnia

Introduction

Finding medication treatment that improves sleep disturbances with posttraumatic stress disorder (PTSD) has challenged the field of psychopharmacology with debate regarding the desirable profile of effects on sleep physiology. Evidence for fragmentation of REM sleep during the earlier stages of PTSD drew our interest to the first marketed dual orexin antagonist, suvorexant, which has been suggested in some studies to enhance REM sleep. This property has also raised concerns regarding potential exacerbation of nightmares and REM sleep related parasomnias. Insomnia is a common sequela of trauma exposure and can occur with and without other PTSD symptoms. The objective of our study was to evaluate the tolerability and preliminary efficacy of suvorexant for trauma related insomnia in a double blind, placebo controlled trial.

Methods

64 met initial inclusion criteria and 42 participants had evaluable results. 65% were female, and 66% African-American, mean age was 35yrs.All participants were screened by the Duke Sleep Disorders Interview to met criteria for insomnia that began or was exacerbated following a DSM5 Criterion A trauma. Approximately a third of the study group met criteria for either current PTSD, past (remitted PTSD), or no PTSD, and 56% reported histories of traumatic nightmares hat generally had diminished from their initial severity.

Results

Medication intolerance was infrequent with one participant in the med group reporting mild sedation that precluded a dose increase to 20mg, and another, moderate sedation with feelings of derealization that led to discontinuation. There was no evidence for emerging nightmare symptoms or REM-related parasomnias. Overall there was significant improvement in sleep and PTSD symptoms in both the placebo and med group and a modest rise in REM sleep in the med group that did not differentiate statistically from placebo.

Conclusion

Our findings suggest that distressing trauma related insomnia can occur with and without PTSD and that suvorexant is well tolerated in this population. A larger and more symptomatic group is required to more definitively evaluate efficacy.

Support (if any)

supported by a grant from Merck (MISP 53678)

Modular cis-regulatory logic of yellow gene expression in silkmoth larvae

Colour patterns in butterflies and moths are crucial traits for adaptation. Previous investigations have highlighted genes responsible for pigmentation (ie yellow and ebony). However, the mechanisms by which these genes are regulated in lepidopteran insects remain poorly understood. To elucidate this, molecular studies involving dipterans have largely analysed the cis-regulatory regions of pigmentation genes and have revealed cis-regulatory modularity. Here, we used well-developed transgenic techniques in Bombyx mori and demonstrated that cis-regulatory modularity controls tissue-specific expression of the yellow gene. We first identified which body parts are regulated by the yellow gene via black pigmentation. We then isolated three discrete regulatory elements driving tissue-specific gene expression in three regions of B. mori larvae. Finally, we found that there is no apparent sequence conservation of cis-regulatory regions between B. mori and Drosophila melanogaster, and no expression driven by the regulatory regions of one species when introduced into the other species. Therefore, the trans-regulatory landscapes of the yellow gene differ significantly between the two taxa. The results of this study confirm that lepidopteran species use cis-regulatory modules to control gene expression related to pigmentation, and represent a powerful cadre of transgenic tools for studying evolutionary developmental mechanisms.

Genetic diversity and relationships among native Japanese horse breeds, the Japanese Thoroughbred and horses outside of Japan using genome-wide SNP data

Eight horse breeds-Hokkaido, Kiso, Misaki, Noma, Taishu, Tokara, Miyako and Yonaguni-are native to Japan. Although Japanese native breeds are believed to have originated from ancient Mongolian horses imported from the Korean Peninsula, the phylogenetic relationships among these breeds are not well elucidated. In the present study, we compared genetic diversity among 32 international horse breeds previously evaluated by the Equine Genetic Diversity Consortium, the eight Japanese native breeds and Japanese Thoroughbreds using genome-wide SNP genotype data. The proportion of polymorphic loci and expected heterozygosity showed that the native Japanese breeds, with the exception of the Hokkaido, have relatively low diversity compared to the other breeds sampled. Phylogenetic and cluster analyses demonstrated relationships among the breeds that largely reflect their geographic distribution in Japan. Based on these data, we suggest that Japanese horses originated from Mongolian horses migrating through the Korean Peninsula. The Japanese Thoroughbreds were distinct from the native breeds, and although they maintain similar overall diversity as Thoroughbreds from outside Japan, they also show evidence of uniqueness relative to the other Thoroughbred samples. This is the first study to place the eight native Japanese breeds and Japanese Thoroughbred in context with an international sample of diverse breeds.

Emotional response to perceived racism and nocturnal heart rate variability in young adult African Americans

BACKGROUND

Heightened autonomic nervous system (ANS) arousal is a well-established contributor to the effect of stress on adverse cardiovascular health outcomes which disproportionately affect African Americans. ANS arousal is normally attenuated during sleep and compromise of this shift is associated with multiple adverse cardiovascular outcomes. Parasympathetic nervous system (PNS) dominance during sleep can be altered by stress. Racism has been recognized to have many negative health consequences in African Americans. Perceived racism has been linked to ANS activity, however, we are not aware of prior research on racism and nocturnal ANS balance.

OBJECTIVE

To examine relationships between perceived racism and nocturnal ANS activity indexed by heart rate variability (HRV) in healthy African American men and women age 18-35.

METHODS

Fifty-four participants completed the Perceived Racism Scale and had 24-hour ambulatory electrocardiogram recordings in their homes. Power spectral analysis was used to derive normalized high frequency (nHF) to index PNS activity which was computed by 5-minute epochs during wake and sleep.

RESULTS

Endorsement of racism and negative emotional reactions during the past year were inversely related to nHF during time in bed. Multiple regression analysis indicated that negative emotional reactions were a significant predictor of nHF during the sleep period F(2,54) = 4.213, p = .020, R² = 0.135 (adjusted R² = 0.103). Relationships during wake were not statistically significant.

CONCLUSION

Findings suggest that perseverative thoughts triggered by negative emotional reactions to racism influencing nocturnal ANS activity may be a pathway by which perceived racism affects health. Support: 3UL1TR001409-02S1 and R01HL087995 to Dr. Mellman.

Neighborhood stress and autonomic nervous system activity during sleep

Study Objectives

Stressful neighborhood environments are known to adversely affect health and contribute to health disparities but underlying mechanisms are not well understood. Healthy sleep can provide a respite from sustained sympathetic nervous system (SNS) activity. Our objective was to evaluate relationships between neighborhood stress and nocturnal and daytime SNS and parasympathetic nervous system (PNS) activity.

Methods

Eighty-five urban-residing African Americans (56.5% female; mean age of 23.0) participated. Evaluation included surveys of neighborhood stress and sleep-related vigilance, and continuous electrocardiogram (ECG) and actigraphic recording in participants' homes from which heart rate variability (HRV) analysis for low frequency/high frequency (LF/HF) ratio and normalized high frequency (nHF), as indicators of SNS and PNS activity, respectively, and total sleep time (TST), and wake after sleep onset were derived.

Results

All significant relationships with HRV measures were from the sleep period. Neighborhood disorder correlated negatively with nHF (r = -.24, p = .035). There were also significant correlations of HRV indices with sleep duration and sleep fears. Among females, LF/HF correlated with exposure to violence, r = .39, p = .008, and nHF with census tract rates for violent crime (r = -.35, p = .035). In a stepwise regression, TST accounted for the variance contributed by violent crime to nHF in the female participants.

Conclusions

Further investigation of relationships between neighborhood environments and SNS/PNS balance during sleep and their consequences, and strategies for mitigating such effects would have implications for health disparities.

Gender and age interact to predict the development of posttraumatic stress disorder symptoms following a motor vehicle accident

OBJECTIVE

Women have a greater overall risk of developing posttraumatic stress disorder (PTSD) than men after exposure to trauma. In addition to gender, other sociodemographic factors have been identified as risk factors for PTSD; however, research has typically examined these factors separately. Age has been found to contribute to the development of psychiatric disorders, and both linear and curvilinear relationships have been reported between age and risk of developing PTSD. Recent research has suggested that this relationship may vary depending on gender.

METHOD

We performed a secondary analysis of data from a prospective study of 287 (164 men, 123 women) motor vehicle accident (MVA) patients (aged 18-81) who completed clinical interviews 6 weeks, 6 months, and/or 1 year after an MVA.

RESULTS

Overall, women developed more severe PTSD symptoms than men; however, gender differences were small in the young (18-24 years) and the old (55 and older) groups. In women, age was not associated with PTSD symptoms at 6 weeks and 6 months; however, age was curvilinearly associated with PTSD severity at 1-year post-MVA such that middle-aged women reported greater symptom severity than younger and older women. Prior trauma exposure and social support mediated this relationship. In men, PTSD severity was not associated with age, but was related to income and social support.

CONCLUSIONS

These findings highlight age-based subgroups of women at elevated risk for PTSD following a traumatic injury and suggest that psychosocial intervention with middle-aged women following trauma exposure may help reduce the risk of persistent PTSD symptoms. (PsycINFO Database Record (c) 2019 APA, all rights reserved).

Simultaneous measurement of patient dose and distribution of indoor scattered radiation during digital breast tomosynthesis

INTRODUCTION

Breast cancer incidence increases from the age of 30 years. As this age range coincides with that in which women usually pursue pregnancy, undergoing medical examinations for conditions such as breast cancer is a concern, especially when pregnancy is uncertain during the first eight weeks. Moreover, in this age range, breast often exhibits a high density, thus compromising diagnosis. For such density, digital breast tomosynthesis (DBT) provides a more accurate diagnosis than 2D mammography given its higher sensitivity and specificity. However, radiation exposure increases during DBT, and it should be determined.

METHODS

We determined the entrance surface dose, scattered radiation dose, and average glandular dose (AGD), which can be mutually compared following an international protocol. Using our proposed method, the distribution of scattered radiation can be easily and quickly obtained with a minor load to the equipment. Then, we can determine the indoor scattered radiation and surface dose on patients during DBT.

RESULTS

We obtained a maximum AGD of 2.32 mGy. The scattered radiation was distributed over both sides with maximum of approximately 40 μGy, whereas the maximum dose around the eye was approximately 10 μGy.

CONCLUSION

By measuring doses using the proposed method, a correct dose information can be provided for patients to mitigate their concerns about radiation exposure. Although the obtained doses were low, their proper management is still required. Overall, the results from this study can help to enhance dose management for patients and safety management regarding indoor radiation.

Impact of strain, sex, and estrous cycle on gamma butyrolactone-evoked absence seizures in rats

Childhood absence epilepsy (CAE) is the most common pediatric epilepsy syndrome and is characterized by typical absence seizures (AS). AS are non-convulsive epileptic seizures characterized by a sudden loss of awareness and bilaterally generalized synchronous 2.5-4 Hz spike and slow-wave discharges (SWD). Gamma butyrolactone (GBL) is an acute pharmacological model of AS and induces bilaterally synchronous SWDs and behavioral arrest. Despite the long use of this model, little is known about its strain and sex-dependent features. We compared the dose-response profile of GBL-evoked SWDs in three rat strains (Long Evans, Sprague-Dawley, and Wistar), and examined the modulatory effects of estrous cycle on SWDs in female Wistar rats. We evaluated the number of seizures, the cumulative time seizing, and the average seizure duration as a function of dose, strain, and sex/estrous phase. Long Evans rats displayed the greatest sensitivity to GBL, followed by Wistar rats, and then by Sprague-Dawley rats. GBL-evoked SWDs were modulated by estrous cycle in female rats, with the lowest sensitivity to GBL occurring during metestrus. Wistar rats showed the greatest variability as a function of dose, and the least variability within dose; these features make this strain desirable for interventional studies. Moreover, our finding that the SWD response to GBL differs as a function of estrous cycle underscores the importance of cycle monitoring in studies examining female animals using this model. Together, these strain and sex-dependent findings provide guidance for future studies.

Enhancement of ADP-Induced Platelet Aggregation by Exercise Test in Coronary Patients and Its Prevention by Pyridinolcarbamate

ADP-induced platelet aggregation in citrated platelet rich plasma (CPRP) was examined using a photoelectric system. To exclude a variation in intensities of platelet aggregation in repeated measurements and to compare intensities of different samples, the maximum deflection of the optical density of CPRP induced by adding ADP solution was divided by a deflection of the optical density of the platelet free plasma and its value, shown as a percentage, was defined as an intensity of ADP-induced platelet aggregation. In this method, the linearity was found in the dose response curve of the platelet aggregation induced by 10−6, 3 × 10−6 and 10−5 molar of ADP with statistical significance. These variation coefficients were less than 5% in the responses induced by the higher doses of ADP. Changes in the ADP-induced platelet aggregation after a Master’s two step test were examined in 13 patients with angina pectoris 3 h after oral administration of placebo or 1 g of pyridinolcarbamate. Under placebo pretreatment, an enhancement of platelet aggregation was observed 1 min after the exercise test with statistical significance (P < 0.01 ∼ 0.05). In the cases of the same subjects pretreated with pyridinolcarbamate, such change was not observed at any time. Using a parallel line assay, an inhibitory effect of pyridinolcarbamate against enhancement of ADP-induced platelet aggregation after the exercise was also recognized with statistical significance (P < 0.01). In the 10 healthy volunteers, there was no statistically significant enhancement of ADP-induced platelet aggregation using any concentration of ADP 1 to 10 min after the exercise test.

Public health and healthcare-associated risk of electric, warm-water bidet toilets

BACKGROUND

In recent years, installation of bidet toilets within hospitals in Japan has raised concerns regarding potential for cross-contamination by antimicrobial-resistant bacteria from patients who are hospitalized over an extended period.

AIM

To investigate the distribution of antimicrobial-resistant bacteria recovered from bidet toilets at a university-affiliated hospital in Japan.

METHODS

All 292 electric bidet toilets at a university hospital were sampled for contamination. Swabs for culture were used to sample water-jet nozzles and toilet seats.

FINDINGS

Of the 292 toilet seats sampled, warm-water nozzles of 254 (86.9%) were found to be contaminated by one or more of the following organisms: Staphylococcus aureus, Streptococcus spp., Enterococcus spp., Enterobacteriaceae and non-Enterobacteriaceae Gram-negative bacteria. S. aureus was recovered from one water-jet nozzle and nine toilet seats; of these, meticillin-resistant S. aureus was recovered from the water-jet nozzle and from one toilet seat. Both the water-jet nozzle and seat of the same toilet were contaminated with a CTX-M-9 group extended-spectrum β-lactamase-producing Escherichia coli. Of the Gram-negative isolates recovered from samples, the organism with the highest frequency of isolation was Stenotrophomonas maltophilia, which was recovered from 39 bidet toilets.

CONCLUSION

Warm-water nozzles of bidet toilets are contaminated with a wide range of bacteria, making them a potential vehicle for cross-infection. In the hospital setting, shared use of bidet toilets must consider the clinical background of patients. Based on these findings, these devices must be part of the risk management programme, and steps should be included for monitoring and disinfection.

Nocturnal autonomic nervous system activity and morning proinflammatory cytokines in young adult African Americans

Compromised sleep and increased sympathetic nervous system (SNS) activity are implicated in the pathogenesis of, and disparities in, cardiovascular disease. Parasympathetic dominance during sleep may be important for cardiovascular health. Sleep and autonomic balance influence immune activity, which impacts atherogenesis. We evaluated relationships between autonomic balance during sleep and morning levels of the immune activating cytokines, C-reactive protein (CRP) and interleukin (IL)-6. Ninety-four (59 female) young adult African Americans without medical conditions and substance use disorders spent 2 consecutive nights in a clinical research unit for sleep recordings and blood drawing on awakening. Cardiac tracings from the second sleep recording were analysed for heart rate variability (HRV). Body mass index was the only non-HRV measure correlated with cytokine levels. Indicators of SNS activity for the presleep, and first non-rapid eye movement (REM) and REM sleep periods were correlated independently with morning IL-6 levels. Altered autonomic balance during sleep may be a modifiable factor that influences immune activation.

Sleep and Processing of Trauma Memories

Sleep has been implicated in learning processes that appear to underlie recovery from posttraumatic stress disorder (PTSD). The importance of quality and timing of sleep following exposure-based therapies has been suggested. The present study evaluated relationships between sleep and adaptive emotional processing following written narrative exposure (WNE) to memories of traumatic events experienced by participants with clinically significant PTSD symptoms. Participants included 21 urban-residing nontreatment-seeking adults with full or subthreshold symptoms of PTSD who completed 4 sessions of 30-min WNE with the first session either in the evening or the morning. There was a significant reduction of PTSD symptom severity after WNE sessions (partial η = .65), but there was no interaction between group assignment based on the initial session's proximity to sleep and initial reduction of PTSD symptom severity (partial η = .01). Polysomnography following evening WNE revealed increased duration of total sleep and N2%, reduced N3%, and increased eye movement density during REM sleep compared with baseline recordings (dz = 0.65 to 1.15). Reduced N3% and increased REM density were associated with less improvement of PTSD symptoms (r = .58 & -.63). These findings suggest a relationship between preservation of diminished arousal during sleep and adaptive trauma memory processing.

Expression and methylation in posttraumatic stress disorder and resilience; evidence of a role for odorant receptors

Post-traumatic stress disorder (PTSD) is a common and potentially disabling disorder that develops in 1/5 to 1/3 of people exposed to severe trauma. Twin studies indicate that genetic factors account for at least one third of the variance in the risk for developing PTSD, however, the specific role for genetic factors in the pathogenesis of PTSD is not well understood. We studied genome-wide gene expression and DNA methylation profiles in 12 participants with PTSD and 12 participants who were resilient to similar severity trauma exposure. Close to 4000 genes were differentially expressed with adjusted p<0.05, fold-change >2, with all but 3 upregulated with PTSD. Eight odorant/olfactory receptor related genes were up-regulated with PTSD as well as genes related to immune activation, the Gamma-Aminobutyric Acid A (GABAA) receptor, and vitamin D synthesis. No differences with adjusted significance for DNA methylation were found. We conclude that increased gene expression may play an important role in PTSD and this expression may not be a consequence of DNA methylation. The role of odorant receptor expression warrants independent replication.

Sandwich ELISA Using a Mouse/Human Chimeric CSLEX-1 Antibody

BACKGROUND

An assay using a mouse antisialyl Lewis X (sLeX) antibody (CSLEX-1) is used clinically for screening and monitoring patients with breast cancer in Japan. However, the IgM isoform of CSLEX-1 is not preferred for the assay because the bulkiness of IgM generally causes poor accessibility to the antigen. To solve this problem, we developed an antisLeX mouse/human chimeric IgG antibody, CH-CSLEX-1, using transgenic silkworms. The performance of a homologous sandwich ELISA of CH-CSLEX1 was then evaluated.

METHODS

To generate CH-CSLEX-1, we used a GAL4/UAS binary gene expression system in transgenic silkworms. The reactivities of CSLEX-1 and CH-CSLEX-1 were determined in a Biacore analysis. To confirm antigen specificity, 3 antigens [sLeX, sLeA, and Lewis Y (LeY)] were used.

RESULTS

CH-CSLEX-1 formed correctly as an IgG class of immunoglobulin molecule with an isoelectric point close to the predicted value. The best combination for capturing and probing in a sandwich ELISA was determined as a homologous combination of CH-CSLEX-1. The CH-CSLEX-1 assay specifically detected sLeX, but not sLeA and LeY. A correlation analysis with 107 human samples showed good concordance between the conventional CSLEX-1 assay (homologous sandwich ELISA using CSLEX-1) and the CH-CSLEX-1 assay (r = 0.98). Moreover, the CH-CSLEX-1 assay was not affected by either human antimouse IgG antibodies (HAMA IgG) or HAMA IgM.

CONCLUSIONS

The mouse/human chimeric antibody CH-CSLEX-1 allowed the establishment of a highly specific sandwich ELISA for sLeX that was not affected by HAMA.

Changes in peripheral anti-Müllerian hormone concentration and their relationship with testicular structure in beef bull calves

The aim of this study was to clarify the time-course of changes in anti-Müllerian hormone (AMH) and testosterone (T) concentrations in peripheral blood and to determine the relationships between blood AMH concentration and testicular development during the early postnatal and prepubertal periods in beef bull calves. A total of 17 Japanese Black bull calves were enrolled in this study. The wk in which the calf was born (within 6 d after birth) was defined as M 0. Blood samples were taken once in every mo from M 0 to M 6 from each bull calf, and plasma AMH and T concentrations were determined. Of the 17 calves, 10 were castrated at 6 mo of age (prepuberty) and the right testis was histologically examined. Plasma AMH concentration (means ± SE) at M 0, 1, and 2 were 123.5 ± 9.8, 189.6 ± 18.7, and 254.6 ± 14.1 ng/mL, respectively. From M 0 through M 2, plasma AMH concentration was significantly greater each mo than in the previous mo (P < 0.05); however, plasma AMH concentration significantly decreased over the last 3 mo of the study (P < 0.05). The average age at which plasma AMH concentration was the highest was 2.3 ± 0.1 mo of age. Plasma T concentration significantly increased from M 0 (0.18 ± 0.02 ng/mL) until M 6 (6.52 ± 1.41 ng/mL). Plasma AMH and T concentrations at M 4, 5, and 6 were significantly negatively correlated (P < 0.05). Linear regression did not reveal a significant relationship between Sertoli or Leydig cell numbers and plasma AMH or T concentrations, respectively. In conclusion, blood AMH concentration peaks at 2 mo of age and is negatively correlated with blood T concentration from 4 to 6 mo of age. Although prepubertal blood AMH or T concentrations did not reflect Sertoli or Leydig cell numbers at the end of the prepubertal period, blood AMH concentration may be indicative of abnormal Sertoli cells function.

Perceived Racism and Ambulatory Blood Pressure in African American College Students

Experiences with racial discrimination may contribute to stress-induced blood pressure (BP) elevations among African Americans. It was reported that perceived racism was associated with ambulatory BP (ABP) during waking hours. This study examined perceived racism and ABP among 40 African American college students, who completed an ABP assessment from which daytime and nighttime averages were computed. Perceived frequency of experiences with racism and racial discrimination was measured using the Perceived Racism Scale. Controlling for gender and body mass index, perceived racism in academic settings was associated with higher diastolic BP (DBP) during waking hours and nighttime sleep. Systolic BP (SBP) was unrelated to perceived racism, and perceived racism in the public realm and in statements from Whites was unrelated to ABP. Perceived racism in academic settings predicted ambulatory DBP among college students. Previous laboratory research has found stronger effects of perceived racism for DBP than SBP. The hemodynamic regulation of BP may explain this phenomenon. Future laboratory and ambulatory studies should assess the contributions of vascular resistance and cardiac output to BP elevations associated with perceived racism.

The impact of posttraumatic stress disorder versus resilience on nocturnal autonomic nervous system activity as functions of sleep stage and time of sleep

Posttraumatic stress disorder (PTSD) has been associated with sleep disturbances including alterations in sleep stages and recently, elevated nocturnal autonomic nervous system (ANS) arousal (i.e., dominance of the sympathetic nervous system over the parasympathetic nervous system). Data suggest that sleep contributes to the regulation of ANS activity. In our previous ambulatory heart rate variability (HRV) monitoring study, strong relationships between sleep and nocturnal ANS activity in resilient participants (i.e., individuals who had never had PTSD despite exposure to high-impact trauma) were not seen with PTSD. In this study, we examined the impact of PTSD vs. resilience on ANS activity as a function of sleep stage and time of sleep. Participants (age 18-35) with current PTSD (n=38) and resilience (n=33) completed two overnight polysomnography recordings in a lab setting. The second night electrocardiogram was analyzed for frequency domain HRV parameters and heart rate within rapid-eye-movement (REM) and non-REM (NREM) sleep periods. Results indicated that ANS arousal indexed by HRV was greater during REM compared with NREM sleep and that the REM-NREM difference was greater in the PTSD than in the resilient participants. This effect of PTSD was reduced to non-significance when analyses controlled for REM sleep percentage, which was lower with PTSD. Exploratory analyses revealed that the REM-NREM difference in HRV was correlated with REM sleep percentage in resilient participants, but not with PTSD. In contrast with our data from home settings, the present study did not find increased overall nocturnal ANS arousal with PTSD. Analyses did reveal higher heart rate during initial NREM sleep with more rapid decline over the course of NREM sleep with PTSD compared with resilience. Findings suggest that elevated ANS arousal indexed by heart rate with PTSD is specific to the early part of sleep and possible impairment in regulating ANS activity with PTSD related to REM sleep.

Blood Pressure Dipping and Urban Stressors in Young Adult African Americans

BACKGROUND

Blunted nocturnal blood pressure (BP) dipping is an early marker of cardiovascular risk that is prevalent among African Americans.

PURPOSE

We evaluated relationships of BP dipping to neighborhood and posttraumatic stress and sleep in urban residing young adult African Americans.

METHODS

One hundred thirty-six black, predominately African American, men and women with a mean age of 22.9 years (SD = 4.6) filled out surveys and were interviewed and had two, 24-h ambulatory BP recordings.

RESULTS

Thirty-eight percent had BP dipping ratios < .10. Wake after sleep onset (WASO), neighborhood disorder and neighborhood poverty rates but not posttraumatic stress symptoms, and other sleep measures correlated significantly with dipping ratios. Models with the neighborhood measures that also included WASO increased the explained variance.

CONCLUSIONS

Studies elucidating mechanisms underlying effects of neighborhoods on BP dipping and the role of disrupted sleep, and how they can be mitigated are important directions for future research.

Autonomic and inflammatory consequences of posttraumatic stress disorder and the link to cardiovascular disease

Stress- and anxiety-related disorders are on the rise in both military and general populations. Over the next decade, it is predicted that treatment of these conditions, in particular, posttraumatic stress disorder (PTSD), along with its associated long-term comorbidities, will challenge the health care system. Multiple organ systems are adversely affected by PTSD, and PTSD is linked to cancer, arthritis, digestive disease, and cardiovascular disease. Evidence for a strong link between PTSD and cardiovascular disease is compelling, and this review describes current clinical data linking PTSD to cardiovascular disease, via inflammation, autonomic dysfunction, and the renin-angiotensin system. Recent clinical and preclinical evidence regarding the role of the renin-angiotensin system in the extinction of fear memory and relevance in PTSD-related immune and autonomic dysfunction is also addressed.

Nocturnal autonomic balance and sleep in PTSD and resilience

Posttraumatic stress disorder (PTSD) has been associated with heightened nocturnal autonomic nervous system (ANS) arousal and sleep disturbances. It has been suggested that relationships between sleep and nocturnal ANS activity are influenced by insomnia; however, investigation of this relationship has been limited in PTSD. This study examined nocturnal ANS activity and its relationship to sleep in PTSD and resilience. Physically healthy young adult African Americans with current PTSD (n = 20) or who had never had PTSD despite exposure to a high-impact traumatic event (resilient, n = 18) were monitored with ambulatory electrocardiograms and actigraphy for 24-hr periods. Frequency-domain heart-rate variability measures, that is, low-frequency to high-frequency ratios (LF/HF), which index sympathetic nervous system activity, and normalized HF (nHF), which indexes parasympathetic nervous system activity were examined. Normalized HF during the time-in-bed period was lower for those with PTSD than those with resilience (p = .041). Total sleep time was strongly correlated with time-in-bed LF/HF (r = -.72) and nHF (r = .75) in the resilient group, but these were not correlated in the PTSD group. The results suggest elevated nocturnal ANS arousal and dissociation between ANS activity and total sleep time in PTSD.

Comprehensive data on ionising radiation from Fukushima Daiichi nuclear power plant in the town of Miharu, Fukushima Prefecture: The Misho Project

Data related to radioactivity released from the Fukushima Daiichi Nuclear Power Plant (FDNPP) accident on 15 March 2011 gathered by residents of Miharu, Fukushima Prefecture, and by Tohoku University are presented. These data sets consist of (1) the earliest radiation monitoring by a Geiger counter in the town, (2) ratios of radioactivity between (132)Te and (137)Cs for a wide area between Fukushima and Tokyo, (3) radiation measurement of soil samples collected from 18 school grounds, and (4) external radiation exposure of 1400 students using OSL badges. By combining and analysing these various data sets, a curve for the cumulative total external exposure as a function of time, with 16 : 00 h on 15 March 2011 being time zero, is obtained. The average cumulative external dosage is estimated to be 10 mSv (σ = 4.2 mSv) over 10 years. In addition, the initiative that the residents of Miharu took in response to the FDNPP accident, which became known as The Misho Project (MP), is documented; in particular, the time at which the municipality instructed the immediate ingestion of iodine tablets by those under the age of 40, 13 : 00 h on 15 March 2011, is assessed.

A relationship between REM sleep measures and the duration of posttraumatic stress disorder in a young adult urban minority population

STUDY OBJECTIVE

To determine relationships of polysomnographic (PSG) measures with posttraumatic stress disorder (PTSD) in a young adult, urban African American population.

DESIGN

Cross-sectional, clinical and laboratory evaluation.

SETTING

Community recruitment, evaluation in the clinical research unit of an urban University hospital.

PARTICIPANTS

Participants (n = 145) were Black, 59.3% female, with a mean age of 23.1 y (SD = 4.8). One hundred twenty-one participants (83.4%) met criteria for trauma exposure, the most common being nonsexual violence. Thirty-nine participants (26.9%) met full (n = 19) or subthreshold criteria (n = 20) for current PTSD, 41 (28.3%) had met lifetime PTSD criteria and were recovered, and 65 (45%) were negative for PTSD.

MEASUREMENTS AND RESULTS

Evaluations included the Clinician Administered PTSD Scale (CAPS) and 2 consecutive nights of overnight PSG. Analysis of variance did not reveal differences in measures of sleep duration and maintenance, percentage of sleep stages, and the latency to and duration of uninterrupted segments of rapid eye movement (REM) sleep by study group. There were significant relationships between the duration of PTSD and REM sleep percentage (r = 0.53, P = 0.001), REM segment length (r = 0.43, P = 0.006), and REM sleep latency (r = -0.34, P < 0.03) among those with current PTSD that persisted when removing cases with, or controlling for, depression.

CONCLUSIONS

The findings are consistent with observations in the literature of fragmented and reduced REM sleep with posttraumatic stress disorder (PTSD) relatively proximate to trauma exposure and nondisrupted or increased REM sleep with chronic PTSD.

CITATION

Mellman TA, Kobayashi I, Lavela J, Wilson B, Hall Brown TS. A relationship between REM sleep measures and the duration of posttraumatic stress disorder in a young adult urban minority population.

Theta frequency activity during rapid eye movement (REM) sleep is greater in people with resilience versus PTSD

Emotional memory consolidation has been associated with rapid eye movement (REM) sleep, and recent evidence suggests that increased electroencephalogram spectral power in the theta (4-8 Hz) frequency range indexes this activity. REM sleep has been implicated in posttraumatic stress disorder (PTSD) as well as in emotional adaption. In this cross-sectional study, thirty young healthy African American adults with trauma exposure were assessed for PTSD status using the Clinician Administered PTSD Scale. Two consecutive night polysomnographic (PSG) recordings were performed and data scored for sleep stages. Quantitative electroencephalographic spectral analysis was used to measure theta frequency components sampled from REM sleep periods of the second-night PSG recordings. Our objective was to compare relative theta power between trauma-exposed participants who were either resilient or had developed PTSD. Results indicated higher right prefrontal theta power during the first and last REM periods in resilient participants compared with participants with PTSD. Right hemisphere prefrontal theta power during REM sleep may serve as a biomarker of the capacity for adaptive emotional memory processing among trauma-exposed individuals.

Validation of the Fear of Sleep Inventory (FOSI) in an urban young adult African American sample

The Fear of Sleep Inventory (FOSI) was developed to identify factors that contribute to sleep disturbances in individuals exposed to trauma. This investigation examined the psychometric properties of the FOSI in a sample of African American young adults residing in urban areas. A 5-factor structure was derived from an exploratory factor analysis and then verified by confirmatory factor analysis. FOSI factors were positively correlated with the severity of PTSD (rs = .30 to .58, all ps < .001) and insomnia symptoms (rs = .36 to .64, all ps < .001). Individuals with probable PTSD or insomnia had higher scores on the total FOSI and each of the factors compared to those without probable PTSD (all ps < .001; effect sizes: r = .32 to .62) or insomnia (all ps < .001; effect sizes: r = .42 to .70). These data expand the evidence that the FOSI identifies factors contributing to sleep disturbances in trauma-exposed individuals.

Awake/sleep cortisol levels and the development of posttraumatic stress disorder in injury patients with peritraumatic dissociation

Differences in the time of day that cortisol is sampled and failure to consider the impact of peritraumatic dissociation have been hypothesized as factors possibly contributing to the inconsistent findings in research examining associations between cortisol levels soon after trauma exposure and the subsequent development of posttraumatic stress disorder (PTSD). The present study examined associations between urinary cortisol levels during wake and sleep times soon after a serious injury and the subsequent development of PTSD in adult patients reporting low or high peritraumatic dissociative (PD) symptoms. Thirty-nine injury patients (20 with high and 19 with low PD symptoms) provided a 15-hour (6 PM to 9 AM) urine sample at 3-weeks post-injury and completed the Clinician Administered PTSD Scale at a 7-week follow-up. Participants collected their urine during wake and sleep times separately. Results showed that in the total sample and in the high PD group, wake, but not sleep, cortisol levels were lower in patients who developed PTSD compared to those who did not. A multiple linear regression analysis revealed a significant main effect of PD and a non-significant interaction between wake cortisol and PD in predicting PTSD symptom severity. In addition, results showed that PD was a better predictor of PTSD symptom severity than wake cortisol levels. These results were consistent with prior research indicating lower afternoon/evening cortisol levels in PTSD and strong associations between PD and PTSD, but did not support the existence of subgroups of PTSD patients (dissociators versus non-dissociators) who may differ in basal cortisol levels.

Gender differences in subjective sleep after trauma and the development of posttraumatic stress disorder symptoms: a pilot study

Women are at higher risk than men for developing posttraumatic stress disorder (PTSD) following certain types of trauma such as accidents and assaults. Sleep disturbances have been implicated in the development of PTSD. Although gender differences in objective sleep soon after trauma have been found in a prior polysomnographic study, gender differences in subjective sleep soon after trauma and their associations to the development of PTSD have not been examined. This pilot study prospectively examined whether gender moderated the relationship between subjective sleep soon after trauma and PTSD symptom development. Injury patients (17 women, 28 men) completed a sleep questionnaire and a 1-week sleep diary 2 weeks after their injuries, and the Clinician Administered PTSD Scale at 7-weeks postinjury. Results showed that women reported greater frequency of nightmares and disruptive nocturnal behaviors (e.g., hot flashes, memories/nightmares about trauma) following the trauma and more severe PTSD symptoms at 7 weeks. Further, gender moderated the relationship between sleep-onset latency and PTSD symptom severity, such that longer sleep-onset latency predicted more severe PTSD symptoms in men, but less severe PTSD symptoms in women. These findings suggest that gender-specific mechanisms may underlie the relationship between sleep impairment and the development of PTSD.

A preliminary study to determine the diagnostic reference level using dose-area product for limited-area cone beam CT

OBJECTIVES

The aim of this study was to measure the dose-area product (DAP) of limited-area cone beam CT (CBCT) units used by dental offices, and to evaluate the rationale of the DAP with an aid of optically stimulated luminescence (OSL) dosemeter in measuring radiation dose.

METHOD

The DAPs of 21 CBCT units used in the dental offices of Tokyo and the surrounding areas from five different manufacturers were measured using OSL nanoDot dosemeter. An assembly of OSL dosemeters with an X-ray film was exposed by CBCT units at exposure parameters commonly used in each dental office. DAP values were then calculated as expressed in mGy cm(2).

RESULTS

DAP values ranged from 126.7 mGy cm(2) to 1476.9 mGy cm(2), depending on the units used.

CONCLUSION

OSL dosemeter coupled with film can be utilized for a large-scale study to measure DAP. The DAP values for individual CBCT units depend not only on the field of view, but also on the exposure parameters adapted by the dental offices.

One's sex, sleep, and posttraumatic stress disorder

Women are approximately twice as likely as men to develop posttraumatic stress disorder (PTSD) after trauma exposure. Mechanisms underlying this difference are not well understood. Although sleep is recognized to have a critical role in PTSD and physical and psychological health more generally, research into the role of sleep in PTSD sex differences has been only recent. In this article, we review both animal and human studies relevant to sex differences in sleep and PTSD with an emphasis on the roles of sex hormones. Sleep impairment including insomnia, trauma-related nightmares, and rapid-eye-movement (REM) sleep fragmentation has been observed in individuals with chronic and developing PTSD, suggesting that sleep impairment is a characteristic of PTSD and a risk factor for its development. Preliminary findings suggested sex specific patterns of sleep alterations in developing and established PTSD. Sleep maintenance impairment in the aftermath of trauma was observed in women who subsequently developed PTSD, and greater REM sleep fragmentation soon after trauma was associated with developing PTSD in both sexes. In chronic PTSD, reduced deep sleep has been found only in men, and impaired sleep initiation and maintenance with PTSD have been found in both sexes. A limited number of studies with small samples have shown that sex hormones and their fluctuations over the menstrual cycle influenced sleep as well as fear extinction, a process hypothesized to be critical to the pathogenesis of PTSD. To further elucidate the possible relationship between the sex specific patterns of PTSD-related sleep alterations and the sexually dimorphic risk for PTSD, future studies with larger samples should comprehensively examine effects of sex hormones and the menstrual cycle on sleep responses to trauma and the risk/resilience for PTSD utilizing various methodologies including fear conditioning and extinction paradigms and animal models.

Subjectively and objectively measured sleep with and without posttraumatic stress disorder and trauma exposure

STUDY OBJECTIVES

Although reports of sleep disturbances are common among individuals with posttraumatic stress disorder (PTSD), results of polysomnographic (PSG) studies have inconsistently documented abnormalities and have therefore suggested "sleep state misperception." The authors' study objectives were to compare sleep parameters measured objectively and subjectively in the laboratory and at home in civilians with and without trauma exposure and PTSD.

DESIGN

Cross-sectional study.

SETTING

PSG recordings in a sleep laboratory and actigraphic recordings in participants' homes.

PARTICIPANTS

One hundred three urban-residing African Americans with and without trauma exposure and PTSD who participated in a larger study.

INTERVENTIONS

N/A.

MEASUREMENTS

Sleep parameters (total sleep time [TST], sleep onset latency [SOL], and wake after sleep onset [WASO]) were assessed using laboratory PSG and home actigraphy. A sleep diary was completed in the morning after PSG and actigraphy recordings. Habitual TST, SOL, and WASO were assessed using a sleep questionnaire. The Clinician Administered PTSD Scale was administered to assess participants' trauma exposure and PTSD diagnostic status.

RESULTS

Participants, regardless of their trauma exposure/PTSD status, underestimated WASO in the diary and questionnaire relative to actigraphy and overestimated SOL in the diary relative to PSG. Among participants with current PTSD, TST diary estimates did not differ from the actigraphy measure in contrast with those without current PTSD who overestimated TST. No other significant group differences in discrepancies between subjective and objective sleep measures were found.

CONCLUSIONS

Discrepancies between subjectively and objectively measured sleep parameters were not associated with trauma exposure or PTSD. This challenges prior assertions that individuals with PTSD overreport their sleep disturbances.