Pain
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Although previous research has examined the relationships between caregiver proximal soothing and infant pain, there is a paucity of work taking infant age into account, despite the steep developmental trajectory that occurs across the infancy period. Moreover, no studies have differentially examined the relationships between caregiver proximal soothing and initial infant pain reactivity and pain regulation. This study examined how much variance in pain reactivity and pain regulation was accounted for by caregiver proximal soothing at 4 routine immunizations (2, 4, 6, and 12 months) across the first year of life, controlling for preneedle distress. ⋯ Preneedle distress and pain reactivity accounted for the largest amount of variance in pain regulation, with this increasing after 2 months. It was concluded that within each immunization appointment across the first year of life, earlier infant pain behaviour is a stronger predictor of subsequent infant pain behaviour than caregiver proximal soothing. Given the longer-term benefits that have been demonstrated for proximal soothing during distressing contexts, caregivers are still encouraged to use proximal soothing during infant immunizations.
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Review Meta Analysis
Animal models of bone cancer pain: systematic review and meta-analyses.
Pain can significantly decrease the quality of life of patients with advanced cancer. Current treatment strategies often provide inadequate analgesia and unacceptable side effects. Animal models of bone cancer pain are used in the development of novel pharmacological approaches. ⋯ Mechanical-evoked pain behaviours were most commonly reported; however, the largest difference was observed in spontaneous pain behaviours. In the spinal cord astrocyte activation and increased levels of Substance P receptor internalisation, c-Fos, dynorphin, tumor necrosis factor-α and interleukin-1β have been reported in bone cancer pain models, suggesting several potential therapeutic targets. However, the translational impact of animal models on clinical pain research could be enhanced by improving methodological quality.
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Bradykinin (BK) is an inflammatory mediator that can evoke oedema and vasodilatation, and is a potent algogen signalling via the B1 and B2 G-protein coupled receptors. In naïve skin, BK is effective via constitutively expressed B2 receptors (B2R), while B1 receptors (B1R) are purported to be upregulated by inflammation. The aim of this investigation was to optimise BK delivery to investigate the algesic effects of BK and how these are modulated by inflammation. ⋯ We have optimised a versatile experimental model by which BK and its analogues can be administered to human skin. We have found that there is an early phase of BK-induced pain which partly depends on the release of inflammatory mediators by MCs; however, subsequent hyperalgesia is not dependent on MC degranulation. In naïve skin, B2R signaling predominates, however, cutaneous inflammation results in enhanced B1R responses.
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The aim of the current study was to determine the course of back pain in older patients and identify prognostic factors for non-recovery at 3 months' follow-up. We conducted a prospective cohort study (the BACE study) of patients aged >55 years visiting a general practitioner (GP) with a new episode of back pain in the Netherlands. The course of back pain was described in terms of self-perceived recovery, pain severity, disability, pain medication, and GP visits at 6 weeks' and 3 months' follow-up. ⋯ At 3 months' follow-up 61% still reported non-recovery, but only 26% of these patients had revisited the GP. Longer duration of the back pain, severity of back pain, history of back pain, absence of radiating pain in the leg below the knee, number of comorbidities, patients' expectation of non-recovery, and a longer duration of the timed 'Up and Go' test were significantly associated with non-recovery in a multiple regression model (AUC 0.79). This information can help GPs identify older back pain patients at risk for non-recovery.
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When a newly developed experimental method to vibrate vellus hairs on human skin was applied to the face and arm in healthy subjects, intense itch was reproducibly induced on the face, but not on the arm, without any flare reactions. In contrast to histamine-induced itch, mechanically evoked itch was not characterized as burning or stinging by any subjects, and was resistant to histamine H1-receptor antagonists. When the stimulation was continued for 10 min, mechanically evoked itch reached the maximum intensity within 10 s, but gradually attenuated after 60 to 90 s and was rarely perceivable at the end of stimulation. ⋯ Touch-alloknesis was present in the adjacent skin area until mechanically evoked itch completely diminished, supporting the hypothesis that itch sensitization can be caused by a continuous activation of peripheral itch neurons whether or not they are histamine-sensitive C nerves. In conclusion, this study provides direct evidence of mechanosensitive nerves involved in itch in human skin. The purity of mechanically evoked itch without any pain-related sensory components is a major advantage for investigating the differentiation of itch from pain.