Pain
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Randomized Controlled Trial Comparative Study
Role of TRPM8 and TRPA1 for cold allodynia in patients with cold injury.
Local cold injury often induces hypersensitivity to cold and cold allodynia. Sensitisation of TRPM8 or TRPA1 could be the underlying mechanisms. This was evaluated by psychophysics and axon-reflex-flare induction following topical menthol and cinnamaldehyde application in cold injury patients and healthy subjects. ⋯ No evidence for sensitisation of responses to TRPM8 or TRPA1-stimulation was found in patients with cold injury-induced cold allodynia. The lack of TRPM8 induced axon-reflex indicates that also de-novo expression of TRPM8 on mechano-insensitive C-nociceptors does not underlie cold allodynia in these patients. We conclude from these data that the mechanisms for the induction of cold allodynia in the patients with cold injury are independent of TRPM8 or TRPA1 and differ therefore from neuropathic pain patients.
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Randomized Controlled Trial Comparative Study
Cytokine profile in human skin in response to experimental inflammation, noxious stimulation, and administration of a COX-inhibitor: a microdialysis study.
Animal studies have documented a critical role for cytokines in cell signaling events underlying inflammation and pain associated with tissue injury. While clinical reports indicate an important role of cytokines in inflammatory pain, methodological limitations have made systematic human studies difficult. This study examined the utility of a human in vivo bioassay combining microdialysis with multiplex immunoassay techniques for measuring cytokine arrays in tissue. ⋯ These results support the utility of explored method for tracking cytokines in human tissue and suggest that anti-hyperalgesic and anti-inflammatory effects of ibuprofen are at least partially dissociated. The data further suggest that high clinical doses of ibuprofen exert anti-inflammatory effects by down-regulating tissue cytokine levels. Explored human bioassay is a promising tool for studying the pathology and pharmacology of inflammatory and chronic pain conditions.
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Randomized Controlled Trial Comparative Study
Evaluation of analgesic effect of skin-to-skin contact compared to oral glucose in preterm neonates.
Nonpharmacological interventions are important alternatives for pain relief during minor procedures in preterm neonates. Skin-to-skin contact or kangaroo mother care is a human and efficient way of caring for low-weight preterm neonates. The aim of the present study was to assess the analgesic effect of kangaroo care compared to oral glucose on the response of healthy preterm neonates to a low-intensity acute painful stimulus. ⋯ In group 3 (glucose, n=31), the neonate was in the prone position in the isolette and received oral glucose (1 ml, 25%) 2 min before heel lancing. A smaller variation in heart rate (p=0.0001) and oxygen saturation (p=0.0012), a shorter duration of facial activity (brow bulge, eye squeeze and nasolabial furrowing) (p=0.0001), and a lower PIPP (Premature Infant Pain Profile) score (p=0.0001) were observed in group 2. In conclusion, skin-to-skin contact produced an analgesic effect in preterm newborns during heel lancing.
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Randomized Controlled Trial Comparative Study
Genetic variability of the mu-opioid receptor influences intrathecal fentanyl analgesia requirements in laboring women.
Labor initiates one of the most intensely painful episodes in a woman's life. Opioids are used to provide analgesia with substantial interindividual variability in efficacy. mu-Opioid receptor (muOR, OPRM1) genetic variants may explain differences in response to opioid analgesia. We hypothesized that OPRM1 304A/G polymorphism influences the median effective dose (ED(50)) of intrathecal fentanyl via combined spinal-epidural for labor analgesia. ⋯ RA confirmed that 304A homozygosity significantly increases intrathecal fentanyl ED(50) (27.4 microg in Group A and 12.8 microg in Group G [p<0.002; 2.1-fold]). We demonstrate for the first time that the muOR 304G variant significantly reduces intrathecal fentanyl ED(50) for labor analgesia, suggesting women with the G variant may be more responsive to opioids and require less analgesic drugs. These findings for intrathecal fentanyl pharmacogenetics may have implications for patients receiving opioids in other settings.
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Randomized Controlled Trial Comparative Study
Spinal cord stimulation normalizes abnormal cortical pain processing in patients with cardiac syndrome X.
Cardiac syndrome X (CSX) is characterized by effort angina, ST-segment depression during stress tests and normal coronary arteries. Abnormal nociception was suggested in these patients by studies showing a reduced cardiac pain threshold; furthermore, we recently found a lack of habituation to pain stimuli using recording of laser evoked potentials (LEPs). In CSX patients with severe angina, spinal cord stimulation (SCS) was shown to improve symptoms. ⋯ Similar results were observed during right-hand stimulation. Our study shows that in CSX patients SCS is able to restore habituation to peripheral pain stimuli. This effect might contribute to restore the ability of CSX patients to better tolerate cardiac pain.