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To investigate the combined impact of somatic and psychosocial factors on symptom severity and physical and mental quality of life (QoL) in male and female patients with chronic pelvic pain syndrome (CPPS).
Learn More >Neurological disorders are increasingly recognised as major causes of death and disability worldwide. The aim of this analysis from the Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2016 is to provide the most comprehensive and up-to-date estimates of the global, regional, and national burden from neurological disorders.
Learn More >Clinical evidence indicates that positive allosteric modulators (PAMs) of GABA receptors have analgesic benefit in addition to efficacy in anxiety disorders. However, the utility of GABA receptor PAMs as analgesics is compromised by the central nervous system side effects of non-selective potentiators. A selective potentiator of GABA receptors associated with α2/3 subunits, KRM-II-81(5-(8-ethynyl-6-(pyridin-2-yl)-4H-benzo[f]imidazo[1,5-a][1,4]diazepin-3-yl)oxazole), has demonstrated anxiolytic, anticonvulsant, and antinociceptive effects in rodents with reduced motoric side effects. The present study evaluated the potential of KRM-II-81 as a novel analgesic. Oral administration of KRM-II-81 attenuated formalin-induced flinching; in contrast, diazepam was not active. KRM-II-81 attenuated nociceptive-associated behaviors engendered by chronic spinal nerve ligation (L5/L6). Diazepam decreased locomotion of rats at the dose tested in the formalin assay (10 mg/kg) whereas KRM-II-81 produced small decreases that were not dose-dependent (10-100 mg/kg). Plasma and brain levels of KRM-II-81 were used to demonstrate selectivity for α2/3- over α1-associated GABA receptors and to define the degree of engagement of these receptors. Plasma and brain concentrations of KRM-II-81 were positively-associated with analgesic efficacy. GABA currents from isolated rat dorsal-root ganglion cultures were potentiated by KRM-II-81 with an ED of 32 nM. Measures of respiratory depression were reduced by alprazolam whereas KRM-II-81 was either inactive or produced effects with lower potency and efficacy. These findings add to the growing body of data supporting the idea that α2/3-selective GABA receptor PAMs will have efficacy and tolerability as pain medications including those for neuropathic pain. Given their predicted anxiolytic effects, α2/3-selective GABA receptor PAMs offer an additional inroad into the management of pain.
Learn More >Recent discovery of mechanosensitive Piezo receptors in trigeminal ganglia suggested the novel molecular candidate for generation of migraine pain. However, the contribution of Piezo channels in migraine pathology was not tested yet. Therefore, in this study, we explored a potential involvement of Piezo channels in peripheral trigeminal nociception implicated in generation of migraine pain.
Learn More >Pain is one of the cardinal signs of inflammation and is present in many inflammatory conditions. Therefore, anti-inflammatory drugs such as NSAIDs also have analgesic properties. We previously showed that prostaglandin D-glycerol ester (PGD-G), endogenously produced by cyclooxygenase-2 from the endocannabinoid 2-arachidonoylglycerol, has anti-inflammatory effects in vitro and in vivo that are partly mediated by DP1 receptor activation. In this work, we investigated its effect in a model of carrageenan-induced inflammatory pain. PGD-G decreased hyperalgesia and edema, leading to a faster recovery. Moreover, PGD-G decreased carrageenan-induced inflammatory markers in the paw as well as inflammatory cell recruitment. The effects of PGD-G were independent from metabolite formation (PGD and 15d-PGJ-G) or DP1 receptor activation in this model. Indeed PGD delayed recovery from hyperalgesia while 15d-PGJ-G worsened the edema. However, while PGD-G decreased hyperalgesia in this model of inflammatory pain, it had no effect when tested in the capsaicin-induced pain model. While the targets mediating the effects of this bioactive lipid in inflammatory pain remain to be elucidated, our findings further support the interest of anti-inflammatory lipid mediators in the management of inflammatory pain.
Learn More >Pain models are commonly used in drug development to demonstrate analgesic activity in healthy subjects and should therefore not cause long-term adverse effects. The ultraviolet B (UVB) model is a model for inflammatory pain in which three times the minimal erythema dose (3MED) is typically applied to induce sensitisation. Based on reports of long-lasting postinflammatory hyperpigmentation (PIH) associated with 3MED, it was decided to investigate the prevalence of PIH among subjects who were previously exposed to 3MED at our research centre. In addition, re-evaluation of the UVB inflammation model using a reduced exposure paradigm (2MED) was performed in healthy subjects.
Learn More >To examine the rates and predictors of long-term opioid therapy in older cancer survivors.
Learn More >Chemotherapy-induced peripheral neuropathy (CIPN) is a major challenge, with increasing impact as oncological treatments, using potentially neurotoxic chemotherapy, improve cancer cure and survival. Acute CIPN occurs during chemotherapy, sometimes requiring dose reduction or cessation, impacting on survival. Around 30% of patients will still have CIPN a year, or more, after finishing chemotherapy. Accurate assessment is essential to improve knowledge around prevalence and incidence of CIPN. Consensus is needed to standardize assessment and diagnosis, with use of well-validated tools, such as the EORTC-CIPN 20. Detailed phenotyping of the clinical syndrome moves toward a precision medicine approach, to individualize treatment. Understanding significant risk factors and pre-existing vulnerability may be used to improve strategies for CIPN prevention, or to use targeted treatment for established CIPN. No preventive therapies have shown significant clinical efficacy, although there are promising novel agents such as histone deacetylase 6 (HDAC6) inhibitors, currently in early phase clinical trials for cancer treatment. Drug repurposing, eg, metformin, may offer an alternative therapeutic avenue. Established treatment for painful CIPN is limited. Following recommendations for general neuropathic pain is logical, but evidence for agents such as gabapentinoids and amitriptyline is weak. The only agent currently recommended by the American Society of Clinical Oncology is duloxetine. Mechanisms are complex with changes in ion channels (sodium, potassium, and calcium), transient receptor potential channels, mitochondrial dysfunction, and immune cell interactions. Improved understanding is essential to advance CIPN management. On a positive note, there are many potential sites for modulation, with novel analgesic approaches.
Learn More >The use of advanced imaging in routine diagnostic practice appears to provide only limited value in patients with migraine who have not experienced recent changes in headache characteristics or symptoms. However, advanced imaging may have potential for studying the biological manifestations and pathophysiology of migraine headaches. Migraine with aura appears to have characteristic spatiotemporal changes in structural anatomy, function, hemodynamics, metabolism, and biochemistry, whereas migraine without aura produces more subtle and complex changes. Large, controlled, multicenter imaging-based observational trials are needed to confirm the anecdotal evidence in the literature and test the scientific hypotheses thought to underscore migraine pathophysiology.
Learn More >Dexmedetomidine (DEX) is a high-selectivity α2 adrenergic receptor agonist. The present study aimed to characterize the analgesic effects of DEX on TNBS-induced chronic inflammatory visceral pain (CIVP) in rats and to evaluate whether its antinociceptive effect is regulated by microRNAs (miRNAs) and the ERK pathway. TNBS with or without DEX was administered to 60 male Sprague-Dawley rats. These rats were randomly classified into four groups: control, TNBS, vehicle, and DEX groups. Pain behaviors were assessed by the abdominal withdrawal reflex (AWR), thermal withdrawal latency (TWL), and mechanical withdrawal threshold (MWT). qPCR, ELISA, and western blotting results showed increased serum IL-1β, TNF-α, and IL-6 levels. RNA microarray and qPCR results indicated that miR-211 was downregulated by CIVP induction but upregulated by DEX administration. ERK signaling was decreased in the TNBS+miR-211 group and increased in the DEX + miR-211 group, indicating that miR-211 targeted the 3'-UTR of the ERK gene. Moreover, ectopic expression of miR-211 in these two groups ameliorated pain behaviors and reduced proinflammatory cytokine production. Therefore, DEX exhibited an analgesic effect on CIVP in rats through a miR-211-mediated MEK/ERK/CREB pathway, suppressing visceral hypersensitivity.
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