Pain
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Adolescents with chronic pain (ACP) often experience impairments in their social functioning. Little is known about the consequences of these impairments on peer relationships of ACP. This study applied social network analysis to examine whether adolescents with more pain problems are less popular (RQ1), adolescents with similar pain problems name each other more often as being part of the same peer group (RQ2), dyads with an adolescent experiencing more pain problems report less positive (eg, support) and more negative (eg, conflict) friendship qualities (RQ3), and positive and negative friendship qualities moderate the relationship between pain and emotional distress (RQ4). ⋯ Finally, positive and negative friendship qualities moderated the relationship between pain and emotional distress. This study contributes to the literature on the importance of peer relationships of ACP. Clinical implications and directions for future research are discussed.
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The transient receptor potential ion channel TRPM3 is highly prevalent on nociceptive dorsal root ganglion (DRG) neurons, but its functions in neuronal plasticity of chronic pain remain obscure. In an animal model of nonspecific low back pain (LBP), latent spinal sensitization known as nociceptive priming is induced by nerve growth factor (NGF) injection. Here, we address the TRPM3-associated molecular basis of NGF-induced latent spinal sensitization at presynaptic level by studying TRPM3-mediated calcium transients in DRG neurons. ⋯ TRPM3 activation provokes an outbreak of pulsatile superoxide production (mitoflash) that comes in the form of a surge in frequency being tunable. We suggest that mitoflash pulsations downstream of TRPM3 activation might be an early signaling event initiating pain sensitization. Tuning of mitoflash activity would be a novel bottom-up therapeutic strategy for chronic pain conditions such as LBP and beyond.
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Chronic low back pain (CLBP) is the leading cause of years lived with disability. Recently, it has been reported that CLBP is associated with alterations in the central nervous system. The present study aimed to investigate the association between CLBP and regional brain atrophy in an older Japanese population. ⋯ In addition, the left superior frontal gyrus was identified as a significant cluster by the Query, Design, Estimate, Contrast interface. There were no significant differences in the brain volumes of pain-related regions between the NCP and the OCP groups. The present study suggests that CLBP is associated with lower brain volumes of pain-related regions in a general older population of Japanese.
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The transient receptor potential cation channel subfamily M member-3 (TRPM3) channel is a recently recognized noxious heat sensor that is involved in inflammatory thermal hyperalgesia. To examine its involvement in the development of hyperalgesia in interstitial cystitis/painful bladder syndrome (IC/PBS), rats with cyclophosphamide (CYP)-induced chronic cystitis were used as a model of IC/PBS. Mechanical and thermal hyperalgesia in lower abdominal region overlying the bladder in CYP rats were measured using von Frey filaments and radiant heat, respectively. ⋯ In CYP rats, pretreatment with the TRPM3 antagonist primidone (2 mg/kg, i.p.) significantly alleviated the mechanical and thermal hyperalgesia, bladder submucosal edema, mast cell infiltration, and bladder hyperactivity. Cyclophosphamide-induced cystitis was associated with TRPM3 upregulation at the mRNA, protein, and functional levels in bladder afferent neurons. Our results suggest that upregulation of TRPM3 channels is involved in the development of chronic pain in CYP-induced cystitis, and targeting TRPM3 may be a pharmacological strategy for treating bladder pain in IC/PBS.
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Pain and related consequences could contribute to comorbid illness and premature mortality in homeless and precariously housed persons. We analyzed longitudinal data from an ongoing naturalistic prospective study of a community-based sample (n = 370) to characterize risk factors and consequences of bodily pain. The aims were to describe bodily pain and associations with symptoms and psychosocial function, investigate factors that may increase or ameliorate pain, and examine the consequences of pain for symptoms, functioning, and all-cause mortality. ⋯ The frequency of prescribed and nonprescribed opioid use had nonlinear relationships with pain: intermittent use was associated with severe pain, without reverse association or change with the overdose epidemic. Greater longitudinal mean pain severity was associated with premature mortality, poorer functioning, and suicidal ideation. Considering the relationships between pain, intermittent opioid use, and depressive symptoms could improve health care for precariously housed patients.