Inter-ictal assay of peripheral circulating inflammatory mediators in migraine patients under adjunctive cervical non-invasive vagus nerve stimulation (nVNS): A proof-of-concept study

Objective

To assay peripheral inter-ictal cytokine serum levels and possible relations with non-invasive vagus nerve stimulation (nVNS) responsiveness in migraineurs.

“龙虎交战”针法针刺八脉交会穴对偏头痛患者头痛天数及血清CGRP表达的影响＊

目的 观察“龙虎交战”针法针刺八脉交会穴对无先兆偏头痛（Migraine without aura，MO）患者头痛天数及外周血降钙素基因相关肽（Calcitonin gene related peptide，CGRP）表达水平的影响。方法 按照头痛程度将90例MO受试者区层随机分为治疗Ⅰ组、治疗Ⅱ组和对照组各30例。治疗Ⅰ组施以“龙虎交战”针法针刺八脉交会穴（外关和足临泣），治疗Ⅱ组施以平补平泻针法针刺八脉交会穴（外关和足临泣），对照组施以平补平泻针法针刺非经非穴点，每次留针30分钟，5次/周，共治疗20次。于治疗前、治疗结束4周后的随访分别记录三组患者头痛天数的变化情况以判定疗效，并采集患者治疗前、治疗结束4周后随访的肘部静脉血用ELISA法检测血清中的CGRP含量的变化。结果 ①各组治疗前患者的头痛天数无显著差异（Ｐ > 0.05），治疗Ⅰ组、治疗Ⅱ组和对照组治疗结束4周后随访的头痛天数较治疗前均显著降低（Ｐ < 0.05）；治疗Ⅰ组头痛天数的降低显著优于治疗Ⅱ组和对照组（Ｐ < 0.001），治疗Ⅱ组头痛天数的降低显著优于对照组（Ｐ < 0.05）；②3组治疗前CGRP的表达无显著差异，治疗Ⅰ组、治疗Ⅱ组治疗结束4周后随访CGRP的表达较治疗前均显著下降（Ｐ < 0.001），对照组治疗结束4周后随访CGRP的表达较治疗前差异无显著性（Ｐ > 0.05）；治疗Ⅰ组CGRP治疗结束4周随访的表达较治疗Ⅱ组和对照组均显著下降（Ｐ < 0.01），治疗Ⅱ组CGRP的表达较对照组显著下降（P < 0.01）。结论 ①八脉交会穴施以“龙虎交战”针法针刺能明显改善MO患者的头痛天数，同时降低MO患者血清CGRP的表达水平，这可能是针刺八脉交会穴治疗MO的机制之一；②非经非穴点的针刺效应无持续性，而八脉交会穴的针刺效应具有持续性；③八脉交会穴可以充分发挥复式针刺手法的治疗效应，提示我们在临床上治疗疾病时不仅要注意腧穴配伍，恰当的针刺手法更是提高临床疗效、事半功倍的关键。     

CGRP相关新型偏头痛药物研究进展

<正>1概述偏头痛是一种慢性致残性疾病,表现为持续4～72 h的中至重度头痛且反复发作,影响着全球高达15%的人口~([1])。在20世纪90年代,偏头痛治疗的重大突破是曲坦类药物的发现。曲坦类药物是特异性5-羟色胺(5-Ht 1b和5-Ht 1 d)受体选择性激动剂,被认为是现有最好的急性偏头痛的特异性治疗药物,它们通过使血管收缩来发挥治疗偏头痛的作     

Effect of nitric oxide synthase inhibitor (L-NAME) on substance P-induced vasodilatation in the dental pulp

AIM: To investigate the vasodilator mechanisms of pulpal vessels, especially the involvement of nitric oxide (NO), during pulpal inflammation. METHODOLOGY: Eleven cats were prepared for intra-arterial administration of test agents through a lingual artery. The pulpal blood flow was measured by laser Doppler flowmetry from ipsilateral mandibular canine teeth. By using the NO synthase (NOS) inhibitor N(G)-nitro L-arginine methyl ester (L-NAME), the effects of L-NAME on various vasodilators, such as Substance P (SP)-, calcitonin-gene related peptide (CGRP)-, and papaverine-induced vasodilatation, were compared in vivo in 11 feline dental pulps. RESULTS: L-NAME pretreatment potentiates SP-induced vasodilatation for a duration of approximately 5 h. The increase of pulpal blood flow ranged from 91.47 to 109.91%, which was significantly different from SP injection alone (48.79%, P < 0.05). Other vasodilators such as CGRP and papaverine did not respond to L-NAME pretreatment. CONCLUSIONS: This study demonstrates that NOS inhibitor L-NAME administration alone has insignificant effects on pulpal blood flow, although L-NAME pretreatment can potentiate SP-induced vasodilatation, probably via increased activity in the enzyme guanylate cyclase. CGRP and papaverine did not respond to L-NAME pretreatment, indicating that they are not mediated via an endothelium-dependent mechanism.     

Unilateral ligature-induced periodontitis influences the expression of neuropeptides in the ipsilateral and contralateral trigeminal ganglion in rats

OBJECTIVES: Expression of neuronal neuropeptides in inflammatory conditions is altered. The changes in expression of substance P (SP) and calcitonin gene-related peptide (CGRP) in ipsilateral and contralateral trigeminal ganglion (TG) neurons were investigated by immunohistochemistry one week after unilateral ligature-induced periodontitis in rats. DESIGN: A retrograde nerve tracer Fluorogold (FG) was applied into the gingival sulcus of the second maxillary molar to identify the neurons in TG that specifically innervate the inflamed gingivomucosa. In addition, neurons from the corresponding maxillary and the adjacent mandibular-ophthalmic regions in TG were analysed. RESULTS: Statistically significantly higher frequencies of CGRP-positive neurons, regardless of their size, were found in TG ipsilateral to the periodontitis (83% and 73% in FG-labelled and maxillary regions, respectively) than in the control group without periodontitis (52% and 42% in FG-labelled and maxillary regions, respectively). The frequency of small FG-labelled SP-positive neurons in the ipsilateral TG (60%) was significantly higher than in the control TG (25%). In the contralateral TG the frequency of CGRP-positive neurons in maxillary region (66%) was significantly higher than in the control group. Surprisingly, the number of SP-positive neurons in all regions of contralateral TG decreased when compared to control and ipsilateral TGs. CONCLUSIONS: Taken together, these results implicate a role of neurogenic component in the pathogenesis of periodontitis. The contralateral response in the TG could be mediated through the transmedian neurological pathways crossing in the trigeminal nuclear complex or through the systemic inflammatory reaction and the activation of the so called "neuro-immune axis".     

Distribution of nerve fibers during the development of palatine glands in rats

Background

Salivary gland maturation and function are modulated by the nervous system. Nevertheless, little is known about salivary gland innervation during development, particularly minor salivary glands. This study investigated the development of the innervation of the palatine glands of rat.

Analysis of nociception, sex and peripheral nerve innervation in the TMEV animal model of multiple sclerosis

Although pain was previously not considered an important element of multiple sclerosis (MS), recent evidence indicates that over 50% of MS patients suffer from chronic pain. In the present study, we utilized the Theiler's murine encephalomyelitis virus (TMEV) model of MS to examine whether changes in nociception occur during disease progression and to investigate whether sex influences the development of nociception or disease-associated neurological symptoms. Using the rotarod assay, TMEV infected male mice displayed increased neurological deficits when compared to TMEV infected female mice, which mimics what is observed in human MS. While both male and female TMEV infected mice exhibited thermal hyperalgesia and mechanical allodynia, female mice developed mechanical allodynia at a faster rate and displayed significantly more mechanical allodynia than male mice. Since neuropathic symptoms have been described in MS patients, we quantified sensory nerve fibers in the epidermis of TMEV-infected and non-infected mice to determine if there were alterations in epidermal nerve density. There was a significantly higher density of PGP9.5 and CGRP-immunoreactive axons in the epidermis of TMEV-infected mice versus controls. Collectively these results indicate that the TMEV model is well suited to study the mechanisms of MS-induced nociception and suggest that alterations in peripheral nerve innervation may contribute to MS pain.     

CGRP release and c-fos expression within trigeminal nucleus caudalis of the rat following glyceryltrinitrate infusion

Neuropeptide release and the expression of c-fos like immunoreactivity (c-fos LI) within trigeminal nucleus caudalis neurons (TNC) are activation markers of the trigeminal nerve system. Glyceryltrinitrate (GTN) is believed to stimulate the trigeminal nerve system, thereby causing headache. We examined the effects of a 30 min NO-donor infusion on CGRP release in jugular vein blood and c-fos LI within TNC of the rat. GTN (2 and 50 microg/kg/min) or NONOate infusion (25 nmol/kg/min) did not cause any CGRP release during and shortly after infusion, whereas administration of capsaicin resulted in strongly increased CGRP levels. GTN infusion (2 microg/kg/min for 30 min) did not lead to enhanced c-fos LI after 2 h and 4 h, whereas capsaicin infusion caused a time- and dose-dependent expression of c-fos LI within laminae I and II of the TNC. Surprisingly, GTN attenuated capsaicin-induced c-fos expression by 64%. The nitric oxide synthase (NOS) inhibitor L-NAME (5 and 50 mg/kg) reduced capsaicin-induced c-fos LI dose dependently (reduction by 13% and 59%). We conclude that GTN may lead to headaches by mechanisms independent of CGRP release from trigeminal nerve fibres. GTN doses comparable to those used in humans did not activate or sensitize the trigeminal nerve system. Both GTN and L-NAME reduced capsaicin-induced c-fos LI. This is most likely due to a feedback inhibition of nitric oxide synthases, which indicates that the c-fos response to capsaicin within TNC is mediated by NO dependent mechanisms.     

Treatment benefit among migraine patients taking fremanezumab: results from a post hoc responder analysis of two placebo-controlled trials

BackgroundMonoclonal antibodies targeting the calcitonin gene-related peptide (CGRP) pathway, including the fully humanized monoclonal antibody (IgG2Δa) fremanezumab, have demonstrated safety and efficacy for migraine prevention. Clinical trials include responders and nonresponders; efficacy outcomes describe mean values across both groups and thus provide little insight into the clinical benefit in responders. Clinicians and their patients want to understand the extent of clinical improvement in patients who respond. This post hoc analysis of fremanezumab treatment attempts to answer this question: what is the benefit in subjects who responded to treatment during the two, phase 3 HALO clinical trials?MethodsWe included subjects with episodic migraine (EM) or chronic migraine (CM) who received fremanezumab quarterly (675 mg/placebo/placebo) or monthly (EM: 225 mg/225 mg/225 mg; CM: 675 mg/225 mg/225 mg) during the 12-week randomized, double-blind, placebo-controlled HALO EM and HALO CM clinical trials. EM and CM responders were defined as participants with a reduction of ≥ 2 or ≥ 4 monthly migraine days, respectively. Treatment benefits evaluated included reductions in monthly migraine days, acute headache medication use, and headache-related disability, and changes in health-related quality of life (HRQoL).ResultsOverall, 857 participants from the HALO trials were identified as responders (EM: 429 [73.8%]; CM: 428 [56.7%]). Reductions in the monthly average number of migraine days were greater among EM (quarterly: 5.4 days; monthly: 5.5 days) and CM (quarterly: 8.7 days; monthly: 9.1 days) responders compared with the overall population. The proportion of participants achieving ≥ 50% reduction in the average monthly number of migraine days was also greater in responders (EM: quarterly, 59.8%; monthly, 63.7%; CM: quarterly, 52.8%; monthly, 59.0%) than in the overall population. Greater reductions in the average number of days of acute headache medication use, greater reductions in headache-related disability scores, and larger improvements in HRQoL were observed among EM and CM responders compared with the overall populations.ConclusionsFremanezumab responders achieved clinically meaningful improvements in all outcomes. The magnitude of improvements with fremanezumab across efficacy outcomes was far greater in responders than in the overall trial population, providing insight into expected treatment benefits in participants who respond to fremanezumab in clinical practice.Trial registrationClinicalTrials.gov identifiers: {"type":"clinical-trial","attrs":{"text":"NCT02629861","term_id":"NCT02629861"}}NCT02629861 (HALO EM) and {"type":"clinical-trial","attrs":{"text":"NCT02621931","term_id":"NCT02621931"}}NCT02621931 (HALO CM).