Impact of different cover letter information and incentives on Veterans' emotional responses to an unsolicited mailed survey about military traumas: a randomized, 3x2x2 factorial trial.

BACKGROUND: Altering cover letter information to reduce non-response bias in trauma research could inadvertently leave survey participants unprepared for potentially upsetting questions. In an unsolicited, mailed survey, we assessed participants' change in affect post-survey after altering key cover letter information and promising different incentives. We tested direct and indirect effects of participants carefully reading the cover letter on changes in their affect post-survey. METHODS: In a 3X2X2 randomized, factorial trial, 480 male and 480 female, nationally representative Veterans who were applying for posttraumatic stress disorder disability benefits were randomized to receive one of 12 different cover letters. The cover letters provided general versus more explicit information about the survey's trauma content and how their names were selected for study; we also promised different incentives for returning the survey. The main outcome was change in affect post-survey. We examined five potential moderators: combat or military sexual trauma exposure, posttraumatic stress disorder or serious mental illness diagnosis, and recency of military service. Mediators between reading the cover letter carefully and post-survey affect included how participants rated the cover letters' information and whether they thought the cover letters prepared them for the survey's content. A Bonferroni corrected alpha of 0.003 was the threshold for statistical significance. RESULTS: One hundred ninety men and 193 women reported their pre-and post-survey affect. Across all study conditions, out of 16 possible points, the net change in affect post-survey was less than a quarter-point for men and women. Mean changes in post-survey affect did not differ statistically significantly across any of the study factors (ps > 0.06); nor were there statistically significant interactions between any of the study factors and the 5 moderators after accounting for multiple comparisons (ps > 0.02). After controlling for pre-survey affect, reading the cover letter carefully had small effects on changes in post-survey affect, with larger associations seen in the women compared to men. Mediators' effects were often in opposite directions for men and women. CONCLUSION: General descriptions of a survey's trauma content appear ethically defensible. Research on cover letters' impacts on survey participants' emotional reactions and how those impacts differ by gender is needed.

Heme Causes Pain in Sickle Mice via Toll-Like Receptor 4-Mediated Reactive Oxygen Species- and Endoplasmic Reticulum Stress-Induced Glial Activation.

Aims: Lifelong pain is a hallmark feature of sickle cell disease (SCD). How sickle pathobiology evokes pain remains unknown. We hypothesize that increased cell-free heme due to ongoing hemolysis activates toll-like receptor 4 (TLR4), leading to the formation of reactive oxygen species (ROS) and endoplasmic reticulum (ER) stress. Together, these processes lead to spinal microglial activation and neuroinflammation, culminating in acute and chronic pain. Results: Spinal heme levels, TLR4 transcripts, oxidative stress, and ER stress were significantly higher in sickle mice than controls. In vitro, TLR4 inhibition in spinal cord microglial cells attenuated heme-induced ROS and ER stress. Heme treatment led to a time-dependent increase in the characteristic features of sickle pain (mechanical and thermal hyperalgesia) in both sickle and control mice; this effect was absent in TLR4-knockout sickle and control mice. TLR4 deletion in sickle mice attenuated chronic and hypoxia/reoxygenation (H/R)-evoked acute hyperalgesia. Sickle mice treated with the TLR4 inhibitor resatorvid; selective small-molecule inhibitor of TLR4 (TAK242) had significantly reduced chronic hyperalgesia and had less severe H/R-evoked acute pain with quicker recovery. Notably, reducing ER stress with salubrinal ameliorated chronic hyperalgesia in sickle mice. Innovation: Our findings demonstrate the causal role of free heme in the genesis of acute and chronic sickle pain and suggest that TLR4 and/or ER stress are novel therapeutic targets for treating pain in SCD. Conclusion: Heme-induced microglial activation via TLR4 in the central nervous system contributes to the initiation and maintenance of sickle pain via ER stress in SCD. Antioxid. Redox Signal. 34, 279-293.

The Psychological Risk of Minimal Risk Activities: A Pre- and Posttest Study Using the Self-Assessment Manikin.

It is difficult to apply U.S. Federal Code of Regulation's criterion for "minimal risk," because benchmarks of minimal risk have not been quantified. Our goal was to examine the psychological risks of several day-to-day activities. Using the Self-Assessment Manikin (SAM), we assessed the state valence and arousal of 432 patients and employees at a large Midwestern Department of Veterans Affairs medical facility before and after they had their blood drawn, saw their primary care physician or mental health provider, or took part in an exercise class. Exercise was associated with near-large to large salutary effects (Cohen's d = 0.76-1.17); other effects were small or moderate in positive directions (Cohen's d = 0.02-0.51). Our findings are a promising start toward establishing benchmarks and quantifying the psychological harms of minimal risk activities. Estimates such as these may help researchers determine whether their own research exceeds minimal risk.

Expanding the role of clinical pharmacists on interdisciplinary primary care teams for chronic pain and opioid management.

BACKGROUND: Facilitating appropriate and safe prescribing of opioid medications for chronic pain management in primary care is a pressing public health concern. Interdisciplinary team-based models of primary care are exploring the expansion of clinical pharmacist roles to support disease management for chronic conditions, e.g. pain. Our study aims to 1) identify roles clinical pharmacists can assume in primary care team based chronic pain care processes and 2) understand the barriers to assuming these expanded roles. METHODS: Setting: Veterans Health Administration (VA) has implemented an interdisciplinary team-based model for primary care which includes clinical pharmacists. DESIGN: We employed an inductive two part qualitative approach including focus groups and semi-structured interviews with key informants. PARTICIPANTS: 60 members of VA primary care teams in two states participated in nine preliminary interdisciplinary focus groups where a semi-structured interview guide elucidated provider experiences with screening for and managing chronic pain. To follow up on emergent themes relating to clinical pharmacist roles, an additional 14 primary care providers and clinical pharmacists were interviewed individually. We evaluated focus group and interview transcripts using the method of constant comparison and produced mutually agreed upon themes. RESULTS: Clinical pharmacists were identified by primary care providers as playing a central role with the ongoing management of opioid therapy including review of the state prescription drug monitoring program, managing laboratory screening, providing medication education, promoting naloxone use, and opioid tapering. Specific barriers to clinical pharmacists role expansion around pain care include: limitations of scopes of practice, insufficient institutional support (low staffing, dedicated time, insufficient training, lack of interdisciplinary leadership support), and challenges and opportunities for disseminating clinical pharmacists' expanded roles. CONCLUSIONS: Expanding the role of the clinical pharmacist to collaborate with providers around primary care based chronic pain management is a promising strategy for improving pain management on an interdisciplinary primary care team. However, expanded roles have to be balanced with competing responsibilities relating to other conditions. Interdisciplinary leadership is needed to facilitate training, resources, adequate staffing, as well as to prepare both clinical pharmacists and the providers they support, about expanded clinical pharmacists' scopes of practice and capabilities.

Cannabinoid receptor-specific mechanisms to alleviate pain in sickle cell anemia via inhibition of mast cell activation and neurogenic inflammation.

Sickle cell anemia is a manifestation of a single point mutation in hemoglobin, but inflammation and pain are the insignia of this disease which can start in infancy and continue throughout life. Earlier studies showed that mast cell activation contributes to neurogenic inflammation and pain in sickle mice. Morphine is the common analgesic treatment but also remains a major challenge due to its side effects and ability to activate mast cells. We, therefore, examined cannabinoid receptor-specific mechanisms to mitigate mast cell activation, neurogenic inflammation and hyperalgesia, using HbSS-BERK sickle and cannabinoid receptor-2-deleted sickle mice. We show that cannabinoids mitigate mast cell activation, inflammation and neurogenic inflammation in sickle mice via both cannabinoid receptors 1 and 2. Thus, cannabinoids influence systemic and neural mechanisms, ameliorating the disease pathobiology and hyperalgesia in sickle mice. This study provides 'proof of principle' for the potential of cannabinoid/cannabinoid receptor-based therapeutics to treat several manifestations of sickle cell anemia.

Small-molecule nociceptin receptor agonist ameliorates mast cell activation and pain in sickle mice.

Treatment of pain with morphine and its congeners in sickle cell anemia is suboptimal, warranting the need for analgesics devoid of side effects, addiction and tolerance liability. Small-molecule nociceptin opioid receptor ligands show analgesic efficacy in acute and chronic pain models. We show that AT-200, a high affinity nociceptin opioid receptor agonist with low efficacy at the mu opioid receptor, ameliorated chronic and hypoxia/reoxygenation-induced mechanical, thermal and deep tissue/musculoskeletal hyperalgesia in HbSS-BERK sickle mice. The antinociceptive effect of AT-200 was antagonized by SB-612111, a nociceptin opioid receptor antagonist, but not naloxone, a non-selective mu opioid receptor antagonist. Daily 7-day treatment with AT-200 did not develop tolerance and showed a sustained anti-nociceptive effect, which improved over time and led to reduced plasma serum amyloid protein, neuropeptides, inflammatory cytokines and mast cell activation in the periphery. These data suggest that AT-200 ameliorates pain in sickle mice via the nociceptin opioid receptor by reducing inflammation and mast cell activation without causing tolerance. Thus, nociceptin opioid receptor agonists are promising drugs for treating pain in sickle cell anemia.

Dominant lethal pathologies in male mice engineered to contain an X-linked DUX4 transgene.

Facioscapulohumeral muscular dystrophy (FSHD) is an enigmatic disease associated with epigenetic alterations in the subtelomeric heterochromatin of the D4Z4 macrosatellite repeat. Each repeat unit encodes DUX4, a gene that is normally silent in most tissues. Besides muscular loss, most patients suffer retinal vascular telangiectasias. To generate an animal model, we introduced a doxycycline-inducible transgene encoding DUX4 and 3' genomic DNA into a euchromatic region of the mouse X chromosome. Without induction, DUX4 RNA was expressed at low levels in many tissues and animals displayed a variety of unexpected dominant leaky phenotypes, including male-specific lethality. Remarkably, rare live-born males expressed DUX4 RNA in the retina and presented a retinal vascular telangiectasia. By using doxycycline to induce DUX4 expression in satellite cells, we observed impaired myogenesis in vitro and in vivo. This mouse model, which shows pathologies due to FSHD-related D4Z4 sequences, is likely to be useful for testing anti-DUX4 therapies in FSHD.

Opioid requirement, opioid receptor expression, and clinical outcomes in patients with advanced prostate cancer.

BACKGROUND: Preclinical studies show that opioids stimulate angiogenesis and tumor progression through the mu opioid receptor (MOR). Although MOR is overexpressed in several human malignancies, the effect of chronic opioid requirement on cancer progression or survival has not been examined in humans. METHODS: We performed a retrospective analysis on 113 patients identified in the Minneapolis VA Tumor Registry (test cohort) and 480 patients from the national VA Central Cancer Registry (validation cohort) who had been diagnosed with stage IV prostate cancer between 1995 and 2010 to examine whether MOR expression or opioid requirement is associated with disease progression and survival. All opioids were converted to oral morphine equivalents for comparison. Laser scanning confocal microscopy was used to analyze MOR immunoreactivity in prostate cancer biopsies. The effects of variables on outcomes were analyzed in univariable and multivariable models. RESULTS: In patients with metastatic prostate cancer, MOR expression and opioid requirement were independently associated with inferior progression-free survival (hazard ratio [HR] 1.65, 95% confidence interval [CI] 1.33-2.07, P<.001 and HR 1.08, 95% CI 1.03-1.13, P<.001, respectively) and overall survival (HR 1.55, 95% CI 1.20-1.99, P<.001 and HR 1.05, 95% CI 1.00-1.10, P = .031, respectively). The validation cohort confirmed that increasing opioid requirement was associated with worse overall survival (HR 1.005, 95% CI 1.002-1.008, P = .001). CONCLUSION: Higher MOR expression and greater opioid requirement are associated with shorter progression-free survival and overall survival in patients with metastatic prostate cancer. Nevertheless, clinical practice should not be changed until prospective randomized trials show that opioid use is associated with inferior clinical outcomes, and that abrogation of the peripheral activities of opioids ameliorates this effect.

Mast cell activation contributes to sickle cell pathobiology and pain in mice.

Sickle cell anemia (SCA) is an inherited disorder associated with severe lifelong pain and significant morbidity. The mechanisms of pain in SCA remain poorly understood. We show that mast cell activation/degranulation contributes to sickle pain pathophysiology by promoting neurogenic inflammation and nociceptor activation via the release of substance P in the skin and dorsal root ganglion. Mast cell inhibition with imatinib ameliorated cytokine release from skin biopsies and led to a correlative decrease in granulocyte-macrophage colony-stimulating factor and white blood cells in transgenic sickle mice. Targeting mast cells by genetic mutation or pharmacologic inhibition with imatinib ameliorates tonic hyperalgesia and prevents hypoxia/reoxygenation-induced hyperalgesia in sickle mice. Pretreatment with the mast cell stabilizer cromolyn sodium improved analgesia following low doses of morphine that were otherwise ineffective. Mast cell activation therefore underlies sickle pathophysiology leading to inflammation, vascular dysfunction, pain, and requirement for high doses of morphine. Pharmacological targeting of mast cells with imatinib may be a suitable approach to address pain and perhaps treat SCA.

Morphine promotes renal pathology in sickle mice.

Patients with sickle cell disease (SCD) are often treated with opioids for severe pain. Although opioids are known to have renal-specific effects, their role in nephropathy in SCD remains unknown. Because a subset of patients receives opioids for long periods of time, we examined the influence of chronic morphine treatment on mice with pre-existing renal disease expressing varying amounts of sickle hemoglobin. Morphine treatment for 3-6 weeks resulted in a variety of defects in renal morphology observed using light and electron microscopy. Notably, morphine induced glomerular pathology, resulting in increased glomerular volume, mesangial expansion, mesangial cell proliferation, parietal cell metaplasia, podocyte effacement, and microvillus transformation. Cystic tubulopathy and hemeoxygenase-1 expression and activity were also increased in morphine-treated mice. Naloxone, a non-selective opioid receptor (OR) antagonist, ameliorated these effects. Functionally, the urine albumin to creatinine ratio was increased following acute as well as chronic morphine treatment. These results suggest that clinically relevant doses of morphine induce renal pathology and that OR antagonists may be effective for ameliorating morphine-induced renal disease.

Influence of morphine on pericyte-endothelial interaction: implications for antiangiogenic therapy.

Morphine stimulates tumor angiogenesis and cancer progression in mice. We examined if morphine influences endothelial-pericyte interaction via platelet-derived growth factor-BB (PDGF-BB) and PDGF receptor-ß (PDGFR-ß). Clinically relevant doses of morphine stimulated PDGF-BB secretion from human umbilical vein endothelial cells and activated PDGFR-ß and mitogen-activated protein kinase/extracellular signal-regulated kinase (MAPK/ERK) phosphorylation in human pericytes. These in vitro effects of morphine were translated into promotion of tumor angiogenesis in a transgenic mice model of breast cancer when treated with clinically used dose of morphine. Increased vessel-associated immunoreactivity of desmin and PDGFR-ß was observed on pericytes in tumors of morphine-treated mice. These data suggest that morphine potentiates endothelial-pericyte interaction via PDGF-BB/PDGFR-ß signaling and promotes tumor angiogenesis, pericyte recruitment, and coverage of tumor vessels. We speculate that morphine may impair the effectiveness of antiangiogenic therapy by influencing vascular pericyte coverage.

Mouse models for studying pain in sickle disease: effects of strain, age, and acuteness.

The clinical management of severe pain associated with sickle cell disease (SCD) remains challenging. Development of an optimal therapy would be facilitated by use of murine model(s) with varying degrees of sickling and pain tests that are most sensitive to vaso-occlusion. We found that young (≤3 months old) NY1DD and S+S(Antilles) mice (having modest and moderate sickle phenotype, respectively) exhibited evidence of deep tissue/musculoskeletal pain. Deep tissue pain and cold sensitivity in S+S(Antilles) mice increased significantly with both age and incitement of hypoxia/reoxygenation (H/R). C57/BL6 mice (genetic background strain of NY1DD and S+S(Antilles) ) were hypersensitive to mechanical and heat stimuli, even without the sickle transgene. H/R treatment of HbSS-BERK mice with severe sickle phenotype resulted in significantly decreased withdrawal thresholds and enhanced mechanical, thermal and deep tissue hyperalgesia. Deep hyperalgesia incited by H/R in HbSS-BERK was ameliorated by CP 55940, a cannabinoid receptor agonist. Thus, assessment of deep tissue pain appears to be the most sensitive measure for studying pain mechanisms across mouse models of SCD, and HbSS-BERK mice may be the best model for vaso-occlusive and chronic pain of SCD.