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A growing body of research has demonstrated a robust link between parental chronic pain and child pain and psychological function. Although the association between parent and child pain is strong, there are limited data to understand environmental and behavioral processes that account for the association and how this develops over time. This longitudinal cohort study was designed to understand potential mechanisms that confer risk or resilience for chronic pain among child offspring of mothers with chronic pain.
We investigated serum levels of 29 cytokines and immune-activated kynurenine and tetrahydrobiopterin pathway metabolites in 15 complex regional pain syndrome (CRPS) subjects and 14 healthy controls. Significant reductions in interleukin-37 and tryptophan were found in CRPS subjects, along with positive correlations between kynurenine/tryptophan ratio and TNF-α levels with kinesiophobia, tetrahydrobiopterin levels with McGill pain score, sRAGE, and xanthurenic acid and neopterin levels with depression, anxiety and stress scores. Using machine learning, we identified a set of binary variables, including IL-37 and GM-CSF, capable of distinguishing controls from established CRPS subjects. These results suggest possible involvement of various inflammatory markers in CRPS pathogenesis.
Background and aims In recent years, focus on assessing descending pain modulation or conditioning pain modulation (CPM) has emerged in patients with chronic pain. This requires reliable and simple to use bed-side tools to be applied in the clinic. The aim of the present pilot study was to develop and provide proof-of-concept of a simple clinically applicable bed-side tool for assessing CPM. Methods A group of 26 healthy volunteers participated in the experiment. Pressure pain thresholds (PPT) were assessed as test stimuli from the lower leg before, during and 5 min after delivering the conditioning tonic painful pressure stimulation. The tonic stimulus was delivered for 2 min by a custom-made spring-loaded finger pressure device applying a fixed pressure (2.2 kg) to the index finger nail. The pain intensity provoked by the tonic stimulus was continuously recorded on a 0-10 cm Visual Analog Scale (VAS). Results The median tonic pain stimulus intensity was 6.7 cm (interquartile range: 4.6-8.4 cm) on the 10 cm VAS. The mean PPT increased significantly (P = 0.034) by 55 ± 126 kPa from 518 ± 173 kPa before to 573 ± 228 kPa during conditioning stimulation. When analyzing the individual CPM responses (increases in PPT), a distribution of positive and negative CPM responders was observed with 69% of the individuals classified as positive CPM responders (increased PPTs = anti-nociceptive) and the rest as negative CPM responders (no or decreased PPTs = Pro-nociceptive). This particular responder distribution explains the large variation in the averaged CPM responses observed in many CPM studies. The strongest positive CPM response was an increase of 418 kPa and the strongest negative CPM response was a decrease of 140 kPa. Conclusions The present newly developed conditioning pain stimulator provides a simple, applicable tool for routine CPM assessment in clinical practice. Further, reporting averaged CPM effects should be replaced by categorizing volunteers/patients into anti-nociceptive and pro-nociceptive CPM groups. Implications The finger pressure device provided moderate-to-high pain intensities and was useful for inducing conditioning stimuli. Therefore, the finger pressure device could be a useful bed-side method for measuring CPM in clinical settings with limited time available. Future bed-side studies involving patient populations are warranted to determine the usefulness of the method.
Nerve injury-induced neuropathic pain is difficult to treat and mechanistically characterized by strong neuroimmune interactions, involving signaling lipids that act via specific G-protein coupled receptors. Here, we investigated the role of the signaling lipid receptor G2A (GPR132) in nerve injury-induced neuropathic pain using the robust spared nerve injury (SNI) mouse model. We found that the concentrations of the G2A agonist 9-HODE (9-Hydroxyoctadecadienoic acid) are strongly increased at the site of nerve injury during neuropathic pain. Moreover, G2A-deficient mice show a strong reduction of mechanical hypersensitivity after nerve injury. This phenotype is accompanied by a massive reduction of invading macrophages and neutrophils in G2A-deficient mice and a strongly reduced release of the proalgesic mediators TNFα, IL-6 and VEGF at the site of injury. Using a global proteome analysis to identify the underlying signaling pathways, we found that G2A activation in macrophages initiates MyD88-PI3K-AKT signaling and transient MMP9 release to trigger cytoskeleton remodeling and migration. We conclude that G2A-deficiency reduces inflammatory responses by decreasing the number of immune cells and the release of proinflammatory cytokines and growth factors at the site of nerve injury. Inhibiting the G2A receptor after nerve injury may reduce immune cell-mediated peripheral sensitization and may thus ameliorate neuropathic pain.
This systematic review evaluates the efficacy, safety and economic impact of dupilumab compared to standard of care for uncontrolled moderate-to-severe atopic dermatitis (AD). Pubmed, EMBASE and Cochrane Library were searched for RCTs and health economic evaluations. Critical and important AD-related outcomes were considered. The risk of bias and the certainty of the evidence were assessed using GRADE. Seven RCTs including 1845 subjects > 12 years treated with dupilumab 16 to 52 weeks were evaluated. For adults there is high certainty that dupilumab decreases SCORAD (MD -30,72; 95%CI -34,65% to -26,79%) and EASI-75 (RR 3.09; 95%CI 2.45 to 3.89), pruritus (RR 2.96; 95%CI 2.37 to 3.70), rescue medication (RR 3.46; 95%CI 2.79 to 4.30), sleep disturbance (MD -7.29; 95%CI -8.23 to -6.35), anxiety/depression (MD -3.08; 95% CI -4.41 to -1.75) and improves quality of life (MD -4.80; 95% CI -5.55 to -4.06). The efficacy for adolescents is similar. Dupilumab-related adverse events (AEs) slightly increase (low certainty). The evidence for dupilumab-related serious AE is uncertain. The incremental cost-effectiveness ratio ranged from 28,500 £ (low certainty) to 124,541 US$ (moderate certainty). More data on long term safety are needed both for children and adults, together with more efficacy data in the paediatric population.
Herpes zoster and postherpetic neuralgia (PHN) are often refractory to current standard treatments and can reduce patients' quality of life (QoL). Pulsed radiofrequency (PRF) effectively controls intractable neurological pain. The aim of the study is to conduct a systematic review and meta-analysis to evaluate the efficacy of PRF in PHN management.
The age of studied animals has a profound impact on experimental outcomes in animal-based research. In mice, age influences molecular, morphological, physiological, and behavioral parameters, particularly during rapid postnatal growth and maturation until adulthood (at 12 weeks of age). Despite this knowledge, most biomedical studies use a wide-spanning age range from 4 to 12 weeks, raising concerns about reproducibility and potential masking of relevant age differences. Here, using mouse behavior and electrophysiology in cultured dorsal root ganglia (DRG), we reveal a decline in behavioral cutaneous touch sensitivity and Piezo2-mediated mechanotransduction in vitro during mouse maturation but not thereafter. In addition, we identify distinct transcript changes in individual Piezo2-expressing mechanosensitive DRG neurons by combining electrophysiology with single-cell RNA sequencing (patch-seq). Taken together, our study emphasizes the need for accurate age matching and uncovers hitherto unknown maturational plasticity in cutaneous touch at the level of behavior, mechanotransduction, and transcripts.
To assess the effectiveness of radiofrequency denervation (RD) of lumbosacral anatomical targets for the management of chronic back pain.
By studying healthy women who do not request analgesia during their first delivery, we investigate genetic effects on labor pain. Such women have normal sensory and psychometric test results, except for significantly higher cuff pressure pain. We find an excess of heterozygotes carrying the rare allele of SNP rs140124801 in KCNG4. The rare variant K6.4-Met419 has a dominant-negative effect and cannot modulate the voltage dependence of K2.1 inactivation because it fails to traffic to the plasma membrane. In vivo, Kcng4 (K6.4) expression occurs in 40% of retrograde-labeled mouse uterine sensory neurons, all of which express K2.1, and over 90% express the nociceptor genes Trpv1 and Scn10a. In neurons overexpressing K6.4-Met419, the voltage dependence of inactivation for K2.1 is more depolarized compared with neurons overexpressing K6.4. Finally, K6.4-Met419-overexpressing neurons have a higher action potential threshold. We conclude that K6.4 can influence human labor pain by modulating the excitability of uterine nociceptors.
On March 11, 2020, the infection caused by the COVID-19 virus was declared a pandemic. Throughout this pandemic, healthcare professionals have experienced difficulties stemming from poor communications, resource scarcity, lack of transparency, disbelief, and threats to the safety of their loved ones, their patients, and themselves. As part of these hardships, negative statements have been heard repeatedly. This paper describes 11 scenarios of unhelpful and dysfunctional messages heard by the authors and their colleagues during the COVID-19 pandemic, reported to us by a combination of peers, administrative leadership, and the public. We explain why not to use such messaging, and we suggest more helpful and compassionate expressions based upon recommendations published by scientific organizations and well-established psychological principles. The first 10 scenarios discussed include 1) lack of understanding regarding the extent of the pandemic, 2) shaming over not seeing patients in person, 3) lack of clear and consistent communication from leadership on pandemic-related practice changes, 4) opinions that personal protective equipment use by healthcare professionals causes fear or is unnecessary, 5) forcing in-person care without appropriate personal protective equipment, 6) the risk of exposure to asymptomatic individuals as it relates to opening clinics, 7) media gag orders, 8) pay and benefit reductions, 9) spreading of misinformation about the COVID-19 pandemic, and 10) workload expectations. The 11th scenario addresses healthcare professionals' psychological and physical reactions to this challenging and prolonged stressful situation. We close by discussing the need for support and compassion at this difficult and unpredictable time and by offering suggestions to foster resilience and feelings of self-efficacy among healthcare professionals.