Pain
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Reactive oxygen species (ROS) are free radicals produced in biological systems that are involved in various degenerative brain diseases. The present study tests the hypothesis that ROS also play an important role in neuropathic pain. In the rat spinal nerve ligation (SNL) model of neuropathic pain, mechanical allodynia develops fully 3 days after nerve ligation and persists for many weeks. ⋯ These data suggest that PBN exerts its anti-allodynic action mainly by spinal mechanisms. Systemic treatment with other spin-trap reagents, 5,5-dimethylpyrroline-N-oxide and nitrosobenzene, showed similar analgesic effects, suggesting that ROS are critically involved in the development and maintenance of neuropathic pain. Thus this study suggests that systemic administration of non-toxic doses of free radical scavengers could be useful for treatment of neuropathic pain.
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Comparative Study
The functional expression of mu opioid receptors on sensory neurons is developmentally regulated; morphine analgesia is less selective in the neonate.
Opioid requirements in neonatal patients are reported to be lower than older infants and this may be a reflection of the developmental regulation of opioid receptors. In this study we have investigated the postnatal regulation of Mu opioid receptor (MOR) function in both rat lumbar dorsal root ganglion (DRG) cultures and behavioural mechanical and thermal reflex tests in rat pups. Immunostaining with MOR and selective neurofilament (NF200) antibodies was combined with calcium imaging of MOR function in cultured neonatal and adult rat dorsal root ganglion cells. ⋯ These experiments show that the MOR expressed on large DRG neurons in neonates are functional and are subject to postnatal developmental regulation. This changing functional receptor profile is consistent with greater morphine potency in mechanical, but not thermal, sensory tests in young animals. These results have important clinical implications for the use of morphine in neonates and provide a possible explanation for the differences in morphine requirements observed in the youngest patients.
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The main objective of this research was to determine the initial psychometric properties of the Faces Pain Scale - Revised (FPS-R) as a measure of pain intensity for use with Catalan children and adolescents. Results of the Catalan version of this scale (FPS-R-C) are similar to those obtained with the original instrument. In order to assess the validity and reliability of the FPS-R-C, two different samples were studied. ⋯ Overall, these results provide preliminary evidence of the reliability, and convergent and criterion-related validity of the FPS-R-C. Moreover, all participating subjects were asked to choose the pain scale they preferred the most. Our data suggest that, regardless of their age and/or gender, the subjects prefer the FPS-R-C to the CAS.
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A patient's readiness to adopt a self-management approach to pain has been hypothesized to increase during multidisciplinary pain treatment and to impact pain coping responses. The Pain Stages of Change Questionnaire (PSOCQ; [J Pain (1997) 227]) was designed to assess four components of readiness to self-manage pain: pre-contemplation, contemplation, action, and maintenance. ⋯ The findings supported all three hypotheses. We discuss the implications of the findings for understanding motivational issues in the self-management of pain.
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Research suggests that anxiety sensitivity may be an important component in the negative response to pain sensations, especially those with cardiopulmonary origin. Furthermore, there is experimental evidence to suggest that such effects may be stronger in women than men. The primary aim of the current investigation was to determine the relative roles that anxiety sensitivity and gender have on the pain reports of patients referred to a hospital clinic with chest pain. ⋯ Finally, evidence was found for the mediating effect of negative interpretative bias on the relationship between anxiety sensitivity and pain. However, this mediating effect was only found in women. These results not only confirm that anxiety sensitivity is related to greater negative pain responses in women, but that this may be due to an increased tendency to negatively interpret sensations.