BackgroundTemporomandibular disorders (TMDs) are characterized by persistent orofacial pain and have diverse etiologic factors that are not well understood. It is thought that central sensitization leads to neuronal hyperexcitability and contributes to hyperalgesia and spontaneous pain. Nonsteroidal anti-inflammatory drugs (NSAIDs) are currently the first choice of drug to relieve TMD pain. NSAIDS were shown to exhibit anticonvulsant properties and suppress cortical neuron activities by enhancing neuronal voltage-gated potassium KCNQ/Kv7 channels (M-current), suggesting that specific activation of M-current might be beneficial for TMD pain.ResultsIn this study, we selected a new anticonvulsant drug retigabine that specifically activates M-current, and investigated the effect of retigabine on inflammation of the temporomandibular joint (TMJ) induced by complete Freund's adjuvant (CFA) in rats. The results show that the head withdrawal threshold for escape from mechanical stimulation applied to facial skin over the TMJ in inflamed rats was significantly lower than that in control rats. Administration of centrally acting M-channel opener retigabine (2.5 and 7.5 mg/kg) can dose-dependently raise the head withdrawal threshold of mechanical allodynia, and this analgesic effect can be reversed by the specific KCNQ channel blocker XE991 (3 mg/kg). Food intake is known to be negatively associated with TMJ inflammation. Food intake was increased significantly by the administration of retigabine (2.5 and 7.5 mg/kg), and this effect was reversed by XE991 (3 mg/kg). Furthermore, intracerebralventricular injection of retigabine further confirmed the analgesic effect of central retigabine on inflammatory TMJ.ConclusionsOur findings indicate that central sensitization is involved in inflammatory TMJ pain and pharmacological intervention for controlling central hyperexcitability by activation of neuronal KCNQ/M-channels may have therapeutic potential for TMDs.

Introduction We sought out to evaluate the effects of oxycodone hydrochloride injection on laparoscopic cholecystectomy (LC), substance P, 5-hydroxytryptamine (5-HT), and patient-controlled intravenous analgesia (PCIA). Materials and Methods A total of 120 eligible patients were randomly divided into an observation group (n=60) and control group (n=60). Oxycodone (0.07 mg/kg) and fentanyl (0.7 μg/kg) were intravenously injected during LC. Substance P and 5-HT were detected by ELISA. Results Heart rate (HR), mean arterial pressure (MAP), and blood oxygen saturation (SpO2) were recorded. Visual analogue scale (VAS), Ramsay scores, and incidence rates of adverse reactions were recorded. The observation group was less prone to agitation, with less affected HR, MAP and SpO2 during recovery. Before and after extubation, and upon leaving the recovery room, substance P and 5-HT increased more slowly in the observation group. After extubation, the control group had higher VAS and Ramsay scores and a higher incidence rate of adverse reactions. Using oxycodone before the end of LC does not delay awakening or affect extubation, but reduces hemodynamic fluctuations, incidence of agitation and release of substance P and 5-HT. It has high safety and stable circulation during recovery. Conclusions Oxycodone used in PCIA after LC effectively mitigates postoperative pain, with milder adverse reactions, which is superior to fentanyl.

The realists and liberalists understand the world from different perspectives and tend to explain the whole world in a divergent way. Here comes the eternal question of the academic circle. Who can explain the world better, realists or liberalists? This question is significant because it helps us to comprehend how world politics function and the current political dilemmas better. We argue that realism can explain history better than liberalism. Constant competitions were always presented through the frequent conflicts between countries. It is an irreversible and most unpreventable nature of the world. Through studying the theories, we are able to examine the world more systematically and logically. The classifications of the subject rationale the complicated and distinct historical events. Moreover, following the steps and various ideas of former scholars allows us to develop our own understanding of the world and determine our perspective.