Pain
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Randomized Controlled Trial Multicenter Study
Acupuncture in patients with acute low back pain: a multicentre randomised controlled clinical trial.
Reviews of the efficacy of acupuncture as a treatment for acute low back pain have concluded that there is insufficient evidence for its efficacy and that more research is needed to evaluate it. A multicentre randomized controlled trial was conducted at 4 primary-care centres in Spain to evaluate the effects of acupuncture in patients with acute nonspecific low back pain in the context of primary care. A total of 275 patients with nonspecific acute low back pain (diagnosed by their general practitioner) were recruited and assigned randomly to 4 different groups: conventional treatment either alone or complemented by 5 sessions over a 2-week period of true acupuncture, sham acupuncture, or placebo acupuncture per patient. ⋯ The primary outcome was the reduction in Roland Morris Disability Questionnaire scores of 35% or more after 2weeks' treatment. The patients in the 3 types of acupuncture groups were blinded to the treatments, but those who received conventional treatment alone were not. In the analysis adjusted for the total sample (true acupuncture relative risk 5.04, 95% confidence interval 2.24-11.32; sham acupuncture relative risk 5.02, 95% confidence interval 2.26-11.16; placebo acupuncture relative risk 2.57 95% confidence interval 1.21-5.46), as well as for the subsample of occupationally active patients, all 3 modalities of acupuncture were better than conventional treatment alone, but there was no difference among the 3 acupuncture modalities, which implies that true acupuncture is not better than sham or placebo acupuncture.
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Many acute stressors reduce pain, a phenomenon called stress-induced antinociception (SIA). Stress also is associated with increased scratching in chronic itch conditions. We investigated effects of acute stressors on facial itch and pain using a recently introduced rat model. ⋯ W-SIA tended to equalize scratching and swiping elicited by 5-HT and AITC compared with no-swim controls, suggesting altered itch and pain processing. Exercise (wheel-running), novelty, cold exposure, and fear (shaker table), key components of swim stress, differentially affected tail-flick latencies and 5-HT-evoked swiping and scratching behavior. Thus, itch and pain can be simultaneously suppressed by a combination of acute stress-related factors via an opioid-independent mechanism.
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Sex differences in the spinal processing of somatic and visceral stimuli contribute to greater female sensitivity in many pain disorders. The present study examined spinal mechanisms that contribute to sex differences in visceral sensitivity. The visceromotor response to colorectal distention (CRD) was more robust in normal female rats and after intracolonic mustard oil compared with that in male rats. ⋯ After intracolonic mustard oil, there was no longer a sex difference in the effect of APV nor GluN1 expression in LS segments, but greater female expression in TL segments. These data document a sex difference in spinal processing of nociceptive visceral stimuli from the normal and inflamed colon. Differences in dorsal horn neuronal activity and NMDA receptor expression contribute to the sex differences in the visceral sensitivity observed in awake rats.