Articles: hyperalgesia.
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Randomized Controlled Trial
The interaction between NGF-induced hyperalgesia and acid-provoked pain in the infrapatellar fat pad and tibialis anterior muscle of healthy volunteers.
Tissue pH is lowered in inflamed tissues, and the increased proton concentration activates acid-sensing ion channels (ASICs), contributing to pain and hyperalgesia. ASICs can be upregulated by nerve growth factor (NGF). The aim of this study was to investigate two new human experimental pain models combining NGF- and acid-induced pain in a randomized, controlled, double-blind study. ⋯ Quantification of two novel pain models combining NGF and acid. Hyperalgesia developed after NGF injection in the infrapatellar fat pad, but it was not facilitated by acid provocation. Contrary, NGF-induced hyperalgesia in muscle tissue was enhanced by acid.
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Randomized Controlled Trial
Cuff Algometry for Estimation of Hyperalgesia and Pain Summation.
Cuff algometry is useful to assess pain sensitivity mechanisms, but effects of cuff position and stimulation pattern are not clear. ⋯ The mid-portion of the lower leg is recommended for cuff placement, and the staircase paradigm provides relevant stimulus intensity for assessment of temporal pain summation.
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Opioids are the most frequently administered analgesics in the perioperative period. The analgesic potency of opioids is without question. While the opioid- free or opioid-less perioperative care concept is not a reality in most surgical centers of the United States and other developed countries, there is a significant number of healthcare problems (i.e. adverse events, opioid-induced hyperalgesia and opioid diversion) related to the indiscriminate use of opioids that warrants the implementation of multimodal analgesia strategies. Although it has been suggested an association between the use of opioids and cancer progression, there is a need of well-designed studies to confirm that association.
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Approximately 60% to 90% of patients with borderline personality disorder (BPD) show nonsuicidal self-injurious behavior (NSSI) with cutting being the most frequently applied method. One of NSSI's functions is to reduce aversive tension. Previous studies have found a tension-reducing effect of painful tissue injury by an incision. ⋯ Our findings confirm that among BPD patients, the nociceptive input leads to stress reduction. In contrast, the impact of tissue damage on stress reduction was relatively small. In addition, the results suggest that painful stimuli lead to a greater stress reduction in BPD patients compared with HCs.
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Here, it is shown that paclitaxel-induced neuropathy is associated with the development of spontaneous activity (SA) and hyperexcitability in dorsal root ganglion (DRG) neurons that is paralleled by increased expression of low-voltage-activated calcium channels (T-type; Cav3.2). The percentage of DRG neurons showing SA and the overall mean rate of SA were significantly higher at day 7 in rats receiving paclitaxel treatment than in rats receiving vehicle. Cav3.2 expression was increased in L4-L6 DRG and spinal cord segments in paclitaxel-treated rats, localized to small calcitonin gene-related peptide and isolectin B4 expressing DRG neurons and to glial fibrillary acidic protein-positive spinal cord cells. ⋯ Paclitaxel induced inward current and action potential discharges in cultured human DRG neurons, and this was blocked by ML218 hydrochloride pretreatment. Furthermore, ML218 hydrochloride decreased firing frequency in human DRG, where spontaneous action potentials were present. In summary, Cav3.2 in concert with TLR4 in DRG neurons appears to contribute to paclitaxel-induced neuropathy.