Pain
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Catecholamine-O-methyltransferase (COMT) is a polymorphic gene whose variants affect enzymatic activity and pain sensitivity via adrenergic pathways. Although COMT represents one of the most studied genes in human pain genetics, findings regarding its association with pain phenotypes are not always replicated. Here, we investigated if interactions among functional COMT haplotypes, stress, and sex can modify the effect of COMT genetic variants on pain sensitivity. ⋯ In both cohorts, the COMT high-pain sensitivity (HPS) haplotype showed robust interaction with stress and number of copies of the HPS haplotype was positively associated with pain sensitivity in nonstressed individuals, but not in stressed individuals. In the post-motor vehicle collision cohort, there was additional modification by sex: the HPS-stress interaction was apparent in males, but not in females. In summary, our findings indicate that stress and sex should be evaluated in association studies aiming to investigate the effect of COMT genetic variants on pain sensitivity.
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Chronic pain is common in HIV, but incompletely characterized, including its underlying etiologies, its effect on healthcare utilization, and the characteristics of affected patients in the HIV primary care setting. These data are needed to design and justify appropriate clinic-based pain management services. Using a clinical data warehouse, we analyzed one year of data from 638 patients receiving standard-of-care antiretroviral therapy in a large primary care HIV clinic, located in the Harlem neighborhood of New York City. ⋯ In summary, our study demonstrates the high prevalence of chronic pain disorders in the primary care HIV clinic. Colocated interventions for chronic pain in this setting should not only focus on musculoskeletal pain but also account for complex multifaceted pain syndromes, and address the unique biopsychosocial features of this population. Furthermore, because chronic pain is prevalent in HIV and associated with increased healthcare utilization, developing clinic-based pain management programs could be cost-effective.
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Neuropathic pain induced by spinal cord injury (SCI) is clinically challenging with inadequate long-term treatment options. Partial pain relief offered by pharmacologic treatment is often counterbalanced by adverse effects after prolonged use in chronic pain patients. Cell-based therapy for neuropathic pain using GABAergic neuronal progenitor cells (NPCs) has the potential to overcome untoward effects of systemic pharmacotherapy while enhancing analgesic potency due to local activation of GABAergic signaling in the spinal cord. ⋯ Intrathecal injection of SHG antibody attenuated analgesic effects of the recombinant grafts suggesting active participation of SHG in these antinociceptive effects. Immunoblots and immunocytochemical assays indicated ongoing recombinant peptide production and secretion in the grafted host spinal cords. These results support the potential for engineered NPCs grafted into the spinal dorsal horn to alleviate chronic neuropathic pain.