Pain
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Repetitive ischemia with reperfusion (I/R) injury is a common cause of myalgia. Ischemia with reperfusion injuries occur in many conditions that differentially affect males and females including complex regional pain syndrome and fibromyalgia. Our preclinical studies have indicated that primary afferent sensitization and behavioral hypersensitivity caused by I/R injury may be due to sex-specific gene expression in the dorsal root ganglia (DRG) and distinct upregulation of growth factors and cytokines in the affected muscles. ⋯ AUF1 knockdown was able to specifically inhibit repeated I/R-induced gene expression in females potentially downstream of prolactin receptor signaling. Data suggest RNA-binding proteins such as pAUF1 may underlie the sex-specific effects on DRG gene expression that modulates behavioral hypersensitivity after repeated I/R injury through prolactin signaling. This study may aid in finding distinct receptor differences related to the evolution of acute to chronic ischemic muscle pain development between sexes.
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Supporting behavioural self-management is increasingly important in the care for chronic widespread pain (CWP), including fibromyalgia. Understanding peoples' experiences of these interventions may elucidate processes and mechanisms that lead to or hinder their intended impact. We conducted a systematic review and thematic synthesis of qualitative studies exploring peoples' experiences of self-management interventions for CWP, including fibromyalgia. ⋯ Lack of on-going support after interventions led to challenges in applying behavioural strategies, and some struggled without social support from the group. The experiences of self-management interventions for CWP reflect a complex, multifaceted process. Although many reported positive experiences, addressing issues with integration of physical activity, group dynamics and postintervention support may improve effectiveness for a broader range of people.
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Voltage-gated sodium (Na v ) channels present untapped therapeutic value for better and safer pain medications. The Na v 1.8 channel isoform is of particular interest because of its location on peripheral pain fibers and demonstrated role in rodent preclinical pain and neurophysiological assays. To-date, no inhibitors of this channel have been approved as drugs for treating painful conditions in human, possibly because of challenges in developing a sufficiently selective drug-like molecule with necessary potency not only in human but also across preclinical species critical to the preclinical development path of drug discovery. ⋯ In this report, we have leveraged numerous physiological end points in nonhuman primates to evaluate the analgesic and pharmacodynamic activity of a novel, potent, and selective Na v 1.8 inhibitor compound, MSD199. These pharmacodynamic biomarkers provide important confirmation of the in vivo impact of Na v 1.8 inhibition on peripheral pain fibers in primates and have high translational potential to the clinical setting. These findings may thus greatly improve success of translational drug discovery efforts toward better and safer pain medications, as well as the understanding of primate biology of Na v 1.8 inhibition broadly.
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Understanding how large language model (LLM) recommendations vary with patient race/ethnicity provides insight into how LLMs may counter or compound bias in opioid prescription. Forty real-world patient cases were sourced from the MIMIC-IV Note dataset with chief complaints of abdominal pain, back pain, headache, or musculoskeletal pain and amended to include all combinations of race/ethnicity and sex. Large language models were instructed to provide a subjective pain rating and comprehensive pain management recommendation. ⋯ Race/ethnicity and sex did not influence LLM recommendations. This study suggests that LLMs do not preferentially recommend opioid treatment for one group over another. Given that prior research shows race-based disparities in pain perception and treatment by healthcare providers, LLMs may offer physicians a helpful tool to guide their pain management and ensure equitable treatment across patient groups.
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Memory biases for pain-related information may contribute to the development and maintenance of chronic pain; however, evidence for when (and for whom) these biases occur is mixed. Therefore, we examined neural, stress, and psychological factors that could influence memory bias, focusing on memories that motivate disabling behaviors: pain perception, conditioned responses to threat-and-safety cues, and responses to aversive nonnoxious stimuli. Two studies were conducted with adolescents with and without chronic pain. ⋯ However, no memory bias was present for the emotional response to an aversive stimulus (US; loud scream) or for the recall of pain intensity. Functional connectivity of the amygdala and hippocampus with memory circuits related to the degree of memory bias, but the specific connections varied between the studies, and we observed no relationship between memory bias and brain morphology. Our findings highlight the value of considering the interaction between implicit and explicit memory systems, contributing to a more comprehensive understanding of emotional memory biases in the context of chronic pain.