This study explored the association between experimentally-induced pain sensitivity and µ-opioid receptor (μOR) availability in patients with temporomandibular disorder (TMD) and further investigated any changes in the pain and μOR availability following high-definition transcranial direct current stimulation (HD-tDCS) over the primary motor cortex (M1) with pilot randomized clinical trials. Seven patients with TMD completed either active (n = 3) or sham treatment (n = 4) for 10 daily sessions and underwent positron emission tomography (PET) scans with [C]carfentanil, a selective μOR agonist, a week before and after treatment. PET imaging consisted of an early resting and late phase with the sustained masseteric pain challenge by computer-controlled injection of 5% hypertonic saline.
View Article and Find Full Text PDFPeptide chemists seek rapid methods combined with facile purification when producing disulphide bonds post solid-phase synthesis. Current methods typically require long reaction times of up to two days, can result in side-products from over-oxidation and/or degradation, require organic solvents, and/or require challenging purification. Herein, we describe a rapid, green, and facile oxidation of a series of peptides with up to three disulphide bonds.
View Article and Find Full Text PDFObjective: The current understanding of utilizing HD-tDCS as a targeted approach to improve headache attacks and modulate endogenous opioid systems in episodic migraine is relatively limited. This study aimed to determine whether high-definition transcranial direct current stimulation (HD-tDCS) over the primary motor cortex (M1) can improve clinical outcomes and endogenous µ-opioid receptor (µOR) availability for episodic migraineurs.
Methods: In a randomized, double-blind, and sham-controlled trial, 25 patients completed 10-daily 20-min M1 HD-tDCS, repeated Positron Emission Tomography (PET) scans with a selective agonist for µOR.
Optimized photocatalytic conversion of CO requires new potent catalysts that can absorb visible light. The photocatalytic reduction of CO using rhenium(i) has been demonstrated but suffers from low turnover. Herein, we describe a [Re(CO)(1-(1,10)phenanthroline-5-(4-nitro-naphthalimide))Cl] photocatalyst, which when combined with the sacrificial donor 1,3-dimethyl-2-phenyl-2,3-dihydro-1-benzo[]imidazole, results in selective production of formic acid and a high turnover number of 533 and turnover frequency of 356 h.
View Article and Find Full Text PDFµ-Opioid receptors (MOR) are a major target of endogenous and exogenous opioids, including opioid pain medications. The µ-opioid neurotransmitter system is heavily implicated in the pathophysiology of chronic pain and opioid use disorder and, as such, central measures of µ-opioid system functioning are increasingly being considered as putative biomarkers for risk to misuse opioids. To explore the relationship between MOR system function and risk for opioid misuse, 28 subjects with chronic nonspecific back pain completed a clinically validated measure of opioid misuse risk, the Pain Medication Questionnaire (PMQ), and were subsequently separated into high (PMQ > 21) and low (PMQ ≤ 21) opioid misuse risk groups.
View Article and Find Full Text PDFHuman chronic latent magnesium deficiency is estimated to impact a substantive portion of the world's population. A number of magnesium compounds have been developed to combat this deficiency; however, none are ideal due to issues of solubility, absorption, side effects (e.g.
View Article and Find Full Text PDFMagnesium deficiency and/or deficit (hypomagnesemia, <0.75 mmol/L in the blood) has become a recognized problem in healthcare and clinical settings. Concomitantly, supplementation has become recognized as the primary means of mitigating such deficiencies.
View Article and Find Full Text PDFBehavioral conditioning and expectation can have profound impact on animal and human physiology. Placebo, administered under positive expectation in clinical trials, can have potent effects on disease pathology, obscuring active medications. Emerging evidence suggests placebo-responsive neurotransmitter systems (e.
View Article and Find Full Text PDFMagnesium (Mg) plays a crucial role in over 80% of all metabolic functions. It is becoming increasingly apparent that magnesium deficiency (hypomagnesemia) may play an important role in chronic disease. To counteract magnesium deficiency, there is an unmet clinical need to develop new fully characterized, highly bioavailable, and substantially water-soluble magnesium supplements.
View Article and Find Full Text PDFObjective: To investigate all-cause and cause-specific mortality in SLE patients between two time periods, 1997-2005 and 2006-14.
Methods: We used an administrative health database from the province of British Columbia, Canada to match all incident SLE patients to 10 non-SLE individuals on sex, age and index date. Cohorts were divided into two subgroups, according to diagnosis year: early cohort 1997-2005 and late cohort 2006-14.
A rhenium(i) naphthalimide complex [Re(CO)3(5-PAN)Cl] (Re(5-PAN); 5-PAN = 1-(1,10-phenanthroline)-4-nitro-naphthalimide) was synthesized, characterized, and evaluated as a photocatalyst for CO2 reduction. Characterization included use of MALDI-ToF mass spectrometry, FT-IR, RAMAN, 1H and 13C NMR, elemental analysis, electronic absorption and emission spectroscopy, single crystal X-ray diffraction, DFT and cyclic voltammetry. Photocatalytic (406 nm) reduction of 13CO2 to formate (H13COO) in the presence of this catalyst was tracked via13C NMR.
View Article and Find Full Text PDFThe coordination chemistry of magnesium (Mg) was extensively explored. More recently; magnesium; which plays a role in over 80% of metabolic functions and governs over 350 enzymatic processes; is becoming increasingly linked to chronic disease-predominantly due to magnesium deficiency (hypomagnesemia). Supplemental dietary magnesium utilizing biorelevant chelate ligands is a proven method for counteracting hypomagnesemia.
View Article and Find Full Text PDFActa Otorrinolaringol Esp (Engl Ed)
July 2021
Introduction: Cochlear implants have been able to treat some types of hearing loss, but those related to cochlear nerve impairment made it necessary to find new ways to manage these deficits; leading to auditory brainstem implants (ABI).
Aim: Our objective is to present the clinical profile of patients treated through an ABI and the results obtained from 1997 to 2017.
Material And Methods: On the one hand, patients with statoacoustic nerve tumours (VIIIcranial nerve) were selected, and on the other hand, patients withoutVIII tumours with congenital malformations of the inner ear.
Addiction neuroscience models posit that recurrent drug use increases reactivity to drug-related cues and blunts responsiveness to natural rewards, propelling a cycle of hedonic dysregulation that drives addictive behavior. Here, we assessed whether a cognitive intervention for addiction, Mindfulness-Oriented Recovery Enhancement (MORE), could restructure reward responsiveness from valuation of drug-related reward back to valuation of natural reward. Before and after 8 weeks of MORE or a support group control, prescription opioid users ( = 135) viewed opioid and natural reward cues while an electroencephalogram biomarker of target engagement was assessed.
View Article and Find Full Text PDFThe enormous advancements in the medical imaging methods witnessed in the past decades have allowed clinical researchers to study the function of the human brain in vivo, both in health and disease. In addition, a better understanding of brain responses to different modalities of stimuli such as pain, reward, or the administration of active or placebo interventions has been achieved through neuroimaging methods. Although magnetic resonance imaging has provided important information regarding structural, hemodynamic, and metabolic changes in the central nervous system related to pain, magnetic resonance imaging does not address modulatory pain systems at the molecular level (eg, endogenous opioid).
View Article and Find Full Text PDFClinicians have the dilemma of prescribing opioid or nonopioid analgesics to chronic pain patients; however, the impact of pain on our endogenous µ-opioid system and how our genetic profile (specifically catechol-O-methyltransferase [] polymorphisms) impacts its activation are currently unknown. Twelve chronic temporomandibular disorder (TMD) patients and 12 healthy controls (HCs) were scanned using positron emission tomography (PET) with [C]carfentanil, a selective radioligand for µ-opioid receptors (µORs). The first 45 min of each PET measured the µOR nondisplaceable binding potential (BP) at resting state, and the last 45 min consisted of a 20-min masseteric pain challenge with an injection of 5% hypertonic saline.
View Article and Find Full Text PDFObjective: To evaluate, in vivo, the impact of ongoing chronic migraine (CM) attacks on the endogenous μ-opioid neurotransmission.
Background: CM is associated with cognitive-emotional dysfunction. CM is commonly associated with frequent acute medication use, including opioids.
Aging leads to cerebral perfusion and functional connectivity changes that have been assessed using various neuroimaging techniques. In addition, a link between these two parameters has been demonstrated in healthy young adults. In this work, we employed arterial spin labeling (ASL) fMRI to measure global and voxel-wise differences in cerebral blood flow (CBF) and intrinsic connectivity contrast (ICC) in the resting state in a group of cognitively normal elderly subjects and a group of cognitively normal young subjects, in order to assess the effects of aging on CBF-ICC coupling, which had not been previously evaluated.
View Article and Find Full Text PDFIntroduction: Smoking rates are up to 2-4 times higher among individuals with mental illness. Hospital readmissions for patients with psychiatric illness within a year of discharge are also high, and there is limited evidence of associations between smoking and these readmissions.
Methods: This study was a secondary data analysis using clinical data of psychiatric inpatients with initial admissions between the years 2000 and 2015.
Reward anticipation dysfunction is associated with major depressive disorder (MDD), but is not universally observed in individuals with MDD. Reward anticipation deficits have also been linked to childhood adversity (CA) and approach/avoidance traits. The present study evaluated whether severity of CA (as measured by the Childhood Trauma Questionnaire) and approach/avoidance traits predict individual differences in blood oxygen level dependent (BOLD) response to reward anticipation beyond MDD diagnosis alone.
View Article and Find Full Text PDFPreclinical studies have shown effects of chronic exposure to addictive drugs on glutamatergic-mediated neuroplasticity in frontostriatal circuitry. These initial findings have been paralleled by human functional magnetic resonance imaging (fMRI) research demonstrating weaker frontostriatal resting-state functional connectivity (rsFC) among individuals with psychostimulant use disorders. However, there is a dearth of human imaging literature describing associations between long-term prescription opioid use, frontostriatal rsFC, and brain morphology among chronic pain patients.
View Article and Find Full Text PDFAppl Neuropsychol Adult
October 2020
Memory difficulties are consistently reported in Major Depressive Disorder (MDD). Nonetheless, it has not been thoroughly investigated as to whether these deficits persist during remission from MDD. A group of 32 healthy young adults with no history of a mood disorder ( = 20.
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