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Background and Purpose: Fibromyalgia is a chronic syndrome marked by intense musculoskeletal pain often refractory to pharmacological treatment. Although studies have shown that hypnosis improves fibromyalgia pain, gaps in experimental design limit their reliability. This work aimed to evaluate the effects of hypnosis on pain, mental health, sleep, and quality of life in participants with fibromyalgia chronic pain., Methods: In this prospective, parallel, randomized, controlled, blindly-evaluated trial, participants of both sexes (n = 49) diagnosed with fibromyalgia and with moderate to severe chronic pain attended 8 weekly 1-h sessions with a hypnotherapist. For the hypnosis group (n = 24), sessions consisted in induction of hypnotic trance followed by suggestions to promote analgesia. For the control group (n = 25), sessions consisted in casual unscripted conversation. Participants were assessed at baseline (7 days before), post-intervention (7 days after), and follow-up (3 months after). The primary outcome was pain intensity. The secondary outcomes were the sensory and affective dimensions of pain; pain unpleasantness; pain catastrophizing; anxiety and depression; sleep quality; fibromyalgia impact; and quality of life., Results: Hypnosis significantly reduced pain scores both at post-intervention and follow-up in comparison with baseline. The analgesic effect of hypnosis combined with pharmacological treatment lasted for at least 3 months and was superior to analgesia promoted by first- and second-line pharmacological treatment alone. Hypnosis significantly improved all parameters evaluated as secondary outcomes both at post-intervention and follow-up without inducing adverse events., Conclusion: Our results corroborate that clinical hypnosis is an effective and feasible tool for managing chronic pain and other symptoms of fibromyalgia., (Copyright © 2024. Published by Elsevier Inc.)

Bothrops leucurus is the major causative agent of venomous snakebites in Northeastern Brazil. Severe pain is the most frequent symptom in these envenomings, with an important inflammatory component. This work characterized the pronociceptive effects evoked by B. leucurus venom (BLV) in mice and the role of inflammatory mediators in these responses. The nociceptive behaviors were quantified by the modified formalin test. The mechanical hyperalgesia was assessed by the digital von Frey test. Pharmacological assays were performed with different antagonists and synthesis inhibitors to investigate the involvement of inflammatory mediators in both nociceptive events. BLV (1-15 μg/paw) injection in mice evoked intense and dose-dependent nociceptive behaviors that lasted for up to 1 h. BLV (10 μg/paw) also caused sustained mechanical hyperalgesia. Histamine and serotonin played a role in the nociception, but not in the BLV-induced mechanical hyperalgesia. Nitric oxide contributed to both responses, but only to the late stages of mechanical hyperalgesia. Eicosanoids were also present in both nociceptive responses. Prostanoid synthesis by COX-1 seemed to be more relevant for the nociception, whereas COX-2 had a more prominent role in the mechanical hyperalgesia. Leukotrienes were the most relevant mediators of BLV-induced mechanical hyperalgesia, hence inhibiting lipoxygenase pathway could be an efficient therapeutic strategy for pain management during envenoming. Our behavioral data demonstrates that BLV promotes nociceptive transmission mediated by biogenic amines, nitric oxide and eicosanoids, and nociceptor sensitization through nitric oxide and eicosanoids. Moreover, phospholipases A 2 (PLA 2 ), an important class of toxins present in bothropic venoms, appear to play an important role in the nociceptive and hypernociceptive response induced by BLV., (Copyright © 2020 Elsevier B.V. All rights reserved.)

The present study was undertaken to characterize the behavioral manifestations of nociception and the local mechanisms involved with the nociceptive response elicited by Latrodectus curacaviensis venom (LCV) in mice. After the intraplantar LCV inoculation, spontaneous nociception, mechanical and thermal nociceptive thresholds, motor performance, edema and cytokine levels were evaluated using von Frey filaments, hot/cold plate, rota-rod, plethismometer and ELISA, respectively. Analysis of LCV was performed by SDS-PAGE and chromatography. Intraplantar injection of LCV (1-100 ng/paw) induced intense and heat-sensitive spontaneous nociception, mediated by serotonin and bradykinin receptors, TRPV1 channels, as well as by transient local inflammation. LCV (0.1-10 ng/paw) induced mechanical allodynia, which was reduced by the local pretreatment with H1 receptor or TRPV1 antagonists. Corroborating the TRPV1 involvement, in thermal nociception assays, LCV induced a similar response to that of capsaicin, a TRPV1 agonist, facilitating the response to noxious hot stimuli and inhibiting the response to cold noxious stimulation. LCV promoted mast cell degranulation, increased IL-1β paw levels, but did not produce a relevant edematogenic effect. Analysis of LCV components showed a predominance of high molecular weight proteins. This work provides the first mechanistic hypothesis to explain the local pain induced by LCV, the most frequent clinical symptom of human envenomation., (Copyright © 2018 Elsevier B.V. All rights reserved.)