107 research outputs found
Comparatives in melanesia:Concentric circles of convergence
Using a sample of 116 languages, this article investigates the typology of comparative constructions and their distribution in Melanesia, one of the world's least-understood linguistic areas. We present a rigorous definition of a comparative construction as a “comparative concept”, thereby excluding many constructions which have been considered functionally comparatives in Melanesia. Conjoined comparatives are shown to dominate at the core of the area on the island of New Guinea, while (monoclausal) exceed comparatives are found in the maritime regions around New Guinea. Outside of Melanesia adpositional and other comparative constructions including particle comparatives are most frequent in Austronesian languages. The unity of the conjoined comparative type in the core Melanesian area illustrates that, while morpho-syntactic profiles of Melanesian languages are heterogenous, significant convergence in the “ways of saying things” can be found across the region. Additionally, we find no cases of clause chaining constructions being used for encoding comparatives, even in canonical clause chaining languages of central New Guinea. Our findings thus offer no support for Stassen's claim of a correlation between temporal chaining type and comparative construction type. Instead we suggest that an areal preference for mini-clauses may explain the dominance of the conjoined comparative in Melanesia
Blocking the CGRP Receptor:Differences across Human Vascular Beds
Multiple drugs targeting the calcitonin gene-related peptide (CGRP) receptor have been developed for the treatment of migraine. Here, the effect of the small-molecule CGRP receptor antagonist zavegepant (0.1 nM–1 µM) on CGRP-induced relaxation in isolated human coronary arteries (HCAs) was investigated. A Schild plot was constructed and a pA2 value was calculated to determine the potency of zavegepant. The potency and Schild plot slopes of atogepant, olcegepant, rimegepant, telcagepant, ubrogepant and zavegepant in HCAs and human middle meningeal arteries (HMMAs), obtained from our earlier studies, were compared. Zavegepant shifted the concentration–response curve to CGRP in HCAs. The corresponding Schild plot slope was not different from unity, resulting in a pA2 value of 9.92 ± 0.24. No potency difference between HCAs and HMMAs was observed. Interestingly, olcegepant, atogepant and rimegepant, with a Schild plot slope < 1 in HCAs, were all >1 log unit more potent in HMMAs than in HCAs, while telcagepant, ubrogepant and zavegepant, with a Schild plot slope not different from unity, showed similar (<1 log difference) potency across both tissues. As a Schild plot slope < 1 may point to the involvement of multiple receptors, it is important to further identify the receptors involved in the relaxation to CGRP in HCAs, which may be used to improve the cardiovascular safety of future antimigraine drugs.</p
Visual hypersensitivity in patients treated with anti-calcitonin gene–related peptide (receptor) monoclonal antibodies
Objective: To evaluate the effect of treatment with anti-calcitonin gene–related peptide (CGRP; receptor) antibodies on visual hypersensitivity in patients with migraine. Background: Increased visual sensitivity can be present both during and outside migraine attacks. CGRP has been demonstrated to play a key role in light-aversive behavior. Methods: In this prospective follow-up study, patients treated for migraine with erenumab (n = 105) or fremanezumab (n = 100) in the Leiden Headache Center were invited to complete a questionnaire on visual sensitivity (the Leiden Visual Sensitivity Scale [L-VISS]), pertaining to both their ictal and interictal state, before starting treatment (T0) and 3 months after treatment initiation (T1). Using a daily e-diary, treatment effectiveness was assessed in weeks 9–12 compared to a 4-week pre-treatment baseline period. L-VISS scores were compared between T0 and T1. Subsequently, the association between the reduction in L-VISS scores and the reduction in monthly migraine days (MMD) was investigated. Results: At 3 months, the visual hypersensitivity decreased, with a decrease in mean ± standard deviation (SD) ictal L-VISS (from 20.1 ± 7.7 to 19.2 ± 8.1, p = 0.042) and a decrease in mean ± SD interictal L-VISS (from 11.8 ± 6.6 to 11.1 ± 7.0, p = 0.050). We found a positive association between the reduction in MMD and the decrease in interictal L-VISS (β = 0.2, p = 0.010) and the reduction in ictal L-VISS (β = 0.3, p = 0.001). Conclusion: A decrease in visual hypersensitivity in patients with migraine after treatment with anti-CGRP (receptor) antibodies is positively associated with clinical response on migraine.</p
Depression and treatment with anti-calcitonin gene related peptide (CGRP) (ligand or receptor) antibodies for migraine
Background and purpose: The aim was to evaluate the effect of anti-calcitonin gene related peptide (CGRP) (ligand or receptor) antibodies on depressive symptoms in subjects with migraine and to determine whether depressive symptoms predict treatment response. Methods: Patients with migraine treated with erenumab and fremanezumab at the Leiden Headache Centre completed daily E-headache diaries. A control group was included. Depressive symptoms were assessed using the Hospital Anxiety and Depression Scale (HADS) and the Center for Epidemiological Studies Depression Scale (CES-D) questionnaires at baseline (T0) and after 3 months (T1). First, the effect of treatment on the reduction in HADS-D and CES-D scores was assessed, with reduction in depression scores as the dependent variable and reduction in monthly migraine days (MMD) and treatment with anti-CGRP medication as independent variables. Second, depression as a predictor of treatment response was investigated, using the absolute reduction in MMD as a dependent variable and age, gender, MMD, active depression, impact, stress and locus of control scores as independent variables. Results: In total, n = 108 patients were treated with erenumab, n = 90 with fremanezumab and n = 68 were without active treatment. Treatment with anti-CGRP medication was positively associated with a reduction in the HADS-D (β = 1.65, p = 0.01) compared to control, independent of MMD reduction. However, the same effect was not found for the CES-D (β = 2.15, p = 0.21). Active depression predicted poorer response to erenumab (p = 0.02) but not to fremanezumab (p = 0.09). Conclusion: Anti-CGRP (ligand or receptor) monoclonals lead to improvement of depressive symptoms in individuals with migraine, independent of migraine reduction. Depression may predict treatment response to erenumab but not to fremanezumab.</p
Both perimenstrual and nonperimenstrual migraine days respond to anti-calcitonin gene-related peptide (receptor) antibodies
Background and purpose: Anti-calcitonin gene-related peptide (CGRP) (receptor) antibodies effectively reduce overall migraine attack frequency, but whether there are differences in effect between perimenstrual and nonperimenstrual migraine days has not been investigated. Methods: We performed a single-arm study among women with migraine. Participants were followed with electronic E-diaries during one (pretreatment) baseline month and 6 months of treatment with either erenumab or fremanezumab. Differences in treatment effect on perimenstrual and nonperimenstrual migraine days were assessed using a mixed effects logistic regression model, with migraine day as dependent variable; treatment, menstrual window, and an interaction term (treatment × menstrual window) as fixed effects; and patient as a random effect. Results: There was no interaction between the menstrual window and treatment effect, indicating that the reduction in migraine days under treatment was similar during the menstrual window and the remainder of the menstrual cycle (odds ratio for treatment = 0.44, 95% confidence interval = 0.38–0.51). Conclusions: Our findings support prophylactic use of anti-CGRP (receptor) antibodies for women with menstrual migraine, as this leads to consistent reductions in number of migraine days during the entire menstrual cycle.</p
Pharmacology of erenumab in human isolated coronary and meningeal arteries:Additional effect of gepants on top of a maximum effect of erenumab
Background and Purpose: Multiple drugs targeting the calcitonin gene-related peptide (CGRP) receptor have been developed for migraine treatment. Here, the effect of the monoclonal antibody erenumab on CGRP-induced vasorelaxation was investigated in human isolated blood vessels, as well as the effect of combining erenumab with the small molecule drugs, namely rimegepant, olcegepant, or sumatriptan.Experimental Approach: Concentration–response curves to CGRP, adrenomedullin or pramlintide were constructed in human coronary artery (HCA) and human middle meningeal artery (HMMA) segments, incubated with or without erenumab and/or olcegepant. pA2 or pKb values were calculated to determine the potency of erenumab in both tissues. To study whether acutely acting antimigraine drugs exerted additional CGRP-blocking effects on top of erenumab, HCA segments were incubated with a maximally effective concentration of erenumab (3 μM), precontracted with KCl and exposed to CGRP, followed by rimegepant, olcegepant, or sumatriptan in increasing concentrations. Key Results: Erenumab shifted the concentration-response curve to CGRP in both vascular tissues. However, in HCA, the Schild plot slope was significantly smaller than unity, whereas this was not the case in HMMA, indicating different CGRP receptor mechanisms in these tissues. In HCA, rimegepant, olcegepant and sumatriptan exerted additional effects on CGRP on top of a maximal effect of erenumab. Conclusions and Implications: Gepants have additional effects on top of erenumab for CGRP-induced relaxation and could be effective in treating migraine attacks in patients already using erenumab as prophylaxis.</p
CGRP, adrenomedullin and adrenomedullin 2 display endogenous GPCR agonist bias in primary human cardiovascular cells.
Agonist bias occurs when different ligands produce distinct signalling outputs when acting at the same receptor. However, its physiological relevance is not always clear. Using primary human cells and gene editing techniques, we demonstrate endogenous agonist bias with physiological consequences for the calcitonin receptor-like receptor, CLR. By switching the receptor-activity modifying protein (RAMP) associated with CLR we can "re-route" the physiological pathways activated by endogenous agonists calcitonin gene-related peptide (CGRP), adrenomedullin (AM) and adrenomedullin 2 (AM2). AM2 promotes calcium-mediated nitric oxide signalling whereas CGRP and AM show pro-proliferative effects in cardiovascular cells, thus providing a rationale for the expression of the three peptides. CLR-based agonist bias occurs naturally in human cells and has a fundamental purpose for its existence. We anticipate this will be a starting point for more studies into RAMP function in native environments and their importance in endogenous GPCR signalling
Investigations with GMC2021 in experimental models predictive of antimigraine activity and coronary side-effect potential
Abstract
Several acutely acting antimigraine drugs, including sumatriptan and other second generation 5-HT1D receptor agonists, have the ability to constrict porcine carotid arteriovenous anastomoses as well as the human isolated coronary artery. These two experimental models seem to serve as indicators, respectively, for the therapeutic and coronary side-effect potential of the compounds. Using these two models, we have now investigated the effects of GMC2021 (3-[2-(dimethylanimo)ethyl]-5-[(trifluoromethyl)sulfonyl]oxy][1 H]indole oxalate, a close analogue of sumatriptan. GMC2021 (30, 100, 300 and 1000 μg · kg−1, i.v.) decreased the total carotid blood flow by exclusively decreasing arteriovenous anastomotic blood flow; capillary blood flow to the skin and ears was moderately increased. The mean ± S.E.M. dose of GMC2021 eliciting a 50% decrease (ED50) in the porcine carotid arteriovenous anastomotic blood flow was found to be 1.1 ± 0.3 μmol · kg−1 and the highest dose (1000 μg · kg−1) produced a 67 ± 4% reduction. The carotid haemodynamic effects of GMC2021 were reduced by the selective 5-HT1D receptor antagonist, GR127935 (N-[methoxy-3-(4-methyl-1-piperazinyl)phenyl]-2′-methyl-4′-(5-methyl-1,2,4-oxadiazol-3-yl)[1,1-biphenyl]-4-carbboxamide hydrochloride), which completely antagonizes porcine carotid haemodynamic responses to sumatriptan (ED50: 0.16 μmol · kg−1, i.v.). Compared to sumatriptan (pD2: 6.12 ± 0.15; Emax: 31.3 ± 12.3% of contractions to 100 mM K+), GMC2021 was less potent in constricting the human isolated coronary artery (pD2: 5.45 ± 0.2; Emax: 21.0 ± 4.8% of contractions to 100 mM K+). The above results suggest that GMC2021 constricts carotid arteriovenous anastomoses partly by a 5-HT1D receptor and partly by another, probably novel, receptor and that GMC2021 should be able to abort migraine headaches in patients, with perhaps a less propensity for coronary side effects
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