Pain
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Comparative Study
Engagement of descending inhibition from the rostral ventromedial medulla protects against chronic neuropathic pain.
A puzzling observation is why peripheral nerve injury results in chronic pain in some, but not all, patients. We explored potential mechanisms that may prevent the expression of chronic pain. Sprague Dawley (SD) or Holtzman (HZ) rats showed no differences in baseline sensory thresholds or responses to inflammatory stimuli. ⋯ Thus, expression of nerve injury-induced pain may ultimately depend on descending modulation. Engagement of descending inhibition protects in the transition from acute to chronic pain. These unexpected findings might provide a mechanistic explanation for medications that engage descending inhibition or mimic its consequences.
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Review Meta Analysis
The population prevalence of foot and ankle pain in middle and old age: a systematic review.
A systematic review and meta-analysis of population-based epidemiological studies was undertaken to determine the prevalence of foot and ankle pain in middle and old age. Searches were conducted in the following electronic databases from inception to October 2010: PubMed, EMBASE, AMED, CINAHL, Cochrane, PEDro, and SportDiscus. Full-text English language articles were included if they used population sample frames, cross-sectional design or analysis, and reported prevalence estimates for foot and/or ankle pain in adults aged 45 years and over. ⋯ Narrative synthesis of evidence from existing studies suggested preponderance in females, an age-related increase in prevalence in women but not men, that the toes/forefoot were the most common anatomical sites of pain, and that moderate disability in an aspect of daily life was reported by two-thirds of cases. This review provides estimates of the community burden of foot and ankle pain in middle and old age. By outlining the scale of this clinical problem, these findings can be used to inform health care planning and provision.
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Randomized Controlled Trial Comparative Study
Randomized trial of group cognitive behavioral therapy compared with a pain education control for low-literacy rural people with chronic pain.
Chronic pain is a common and costly experience. Cognitive behavioral therapies (CBT) are efficacious for an array of chronic pain conditions. However, the literature is based primarily on urban (white) samples. ⋯ Clinical significance of the findings and the number of treatment responders is reported. Overall, these findings indicate that CBT and EDU are viable treatment options in low-SES minority and nonminority groups. Further research should target disseminating and sustaining psychosocial treatment options within underserved populations.
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Multicenter Study
The mediating role of pain in substance use and depressive symptoms among Multicenter AIDS Cohort Study (MACS) participants.
Pain in human immunodeficiency virus (HIV) frequently co-occurs with substance use and depression. The complex associations among patient characteristics, pain, depression, and drug use in HIV suggests a role for testing models that can account for relationships simultaneously, control for HIV status, and also test for mediation. Using structural equation modeling, the current study examined associations among pain, sociodemographics, illicit drug use, and depressive symptoms in 921 HIV-seropositive and 1019 HIV-seronegative men from the Multicenter AIDS Cohort Study, an ongoing prospective study of the natural history of HIV infection among gay/bisexual men. ⋯ HIV-seropositive status predicted more use of inhaled nitrites. In this cohort, having lower CD4+ cell counts (predicted by HIV status), being African American, less educated, and older were all associated with more pain, which, in turn, was associated with more illicit drug use and more depressive symptoms. The results underscore the need for adequate pain management, particularly among vulnerable subgroups of HIV-seropositive and HIV-seronegative men to reduce the risk of drug use and depression.
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Randomized Controlled Trial Comparative Study
TRP-channel-specific cutaneous eicosanoid release patterns.
Analyzing mechanisms and key players in peripheral nociception nonneuronal skin cells are getting more and more into focus. Herein we investigated the functional expression of TRPV1 and TRPA1 in human keratinocytes and fibroblasts and assessed proinflammatory lipid mediator release upon their stimulation as well as sensory effects after topical application, combining in vitro and in vivo approaches. In vitro, the expression of functional TRPV1 and TRPA1 channels on fibroblasts and keratinocytes was confirmed via immunofluorescence, qualitative real time (RT) polymerase chain reaction, and cellular Ca(2+) influx measurements. ⋯ In parallel, heat pain thresholds were reduced by both agents after short-term topical application, but only AITC provoked a long-lasting local erythema. In conclusion, the agonist-induced activation of nociceptors by TRPA1 and TRPV1 elicits painful sensations, whereas nonneuronal tissue cells respond with differential release of inflammatory mediators, thus influencing local vasodilatation and neuronal sensitization. These results have implications for the application of transient receptor potential antagonists to improve inflammatory skin conditions and pain management.