European journal of pain : EJP
-
There is a predominance of chronic widespread musculoskeletal complaints (WMSC) among women. Previous studies suggest an association between hormonal factors and pain. However, it is not known whether earlier age at menarche is associated with higher prevalence of chronic WMSC. The aim of this study was to investigate the association between age at menarche and chronic WMSC. ⋯ In this cross-sectional study, there was an association between early age at menarche and chronic WMSC later in life, but the difference in absolute risk was low (3%).
-
Recent studies applied laser-evoked potentials (LEP) for the analysis of small nerve fibre function and focused on the detection of stable C-fibre-mediated potentials (C-LEPs); high technical requirements were needed. The diagnostic significance is still controversially discussed. So far, only few studies focused on the susceptibility of C-LEPs to distraction and other influences. We hypothesized that C-LEPs are altered by habituation processes and distraction. ⋯ In the approach of detecting C-fibre-mediated potentials with LEP, future studies should take the high susceptibility to distraction and habituation into account.
-
(-)-Epigallocatechin-3-gallate (EGCG) is the major polyphenolic constituent found in green tea. It has been reported that may be a natural agent for reducing thermal and mechanical pain after nervous system injuries. However, the molecular pathways implicated in these beneficial effects have not been completely elucidated. This study aimed to assess the EGCG treatment effects on thermal hyperalgesia, spinal cord gliosis and modulation of Ras homologue gene family member A (RhoA), fatty acid synthase (FASN) and tumour necrosis factor alpha (TNF-α) expression after spinal cord contusion in mice. ⋯ These findings suggest that at short time EGCG treatment reduces thermal hyperalgesia and gliosis via FASN and RhoA pathway, causing a decrease in cytokines in spinal cord.
-
The assessment of facial expressions associated with pain has been used to evaluate pain in humans and has recently found application in non-human mammals. These so called 'grimace scales' have the potential to be developed into a widely accepted non-invasive method of measuring pain in laboratory rodents. Currently, common methodologies to assess pain rely on nociceptive tests that assess stimulus evoked withdrawal responses. These tests, however, are limited to the assessment of a reflexive response without an affective component. This study aimed to use the recently developed Rat Grimace Scale (RGS) and assess its relationship with a conventional nociceptive test (the application of von Frey filaments). ⋯ This study confirms that the three pain models induce pain in rodents and showed that peak pain coincided with peak mechanical hypersensitivity. However, mechanical hypersensitivity remained once pain subsided, mimicking the human experience of CFA injection. These findings further our understanding of the roles of, and relationship between, these assays in the assessment of nociception and pain.
-
Combining drugs not only reduces specific adverse effects of each of the drug at a higher dose but also may lead to enhanced efficacy. Tapentadol is a recently discovered analgesic possessing μ-opioid receptor agonism and noradrenaline re-uptake inhibition in a single molecule. Taking into consideration, the pharmacological similarities between opioids and cannabinoids, we assumed that combination of cannabinoids with noradrenaline re-uptake inhibitors might also be effective. We therefore aimed to determine whether combining 1:1, 1:3 and 3:1 fixed ratios of the synthetic cannabinoid WIN 55,212-2 and the selective noradrenaline re-uptake inhibitor maprotiline exert anti-allodynic synergy on nerve-injured neuropathic mice. ⋯ Overall, our data suggest that combination of a cannabinoid with a selective noradrenaline re-uptake inhibitor may offer a beneficial treatment option for neuropathic pain.