Displaying all 12 publications

Abstract:
Sort:
  1. A male with recurrent infections and mediastinal mass
    Hamid FA, Hasbullah AHH, Ban AY
    Breathe (Sheff), 2020 Dec;16(4):200065.
    PMID: 33447285 DOI: 10.1183/20734735.0065-2020
    Can you diagnose this patient with recurrent pneumonia and myasthenia gravis? https://bit.ly/2IBaxC1.
    Matched MeSH terms: Receptors, Cholinergic
  2. Outcome of children with acetylcholine receptor (AChR) antibody positive juvenile myasthenia gravis following thymectomy
    Heng HS, Lim M, Absoud M, Austin C, Clarke D, Wraige E, et al.
    Neuromuscul Disord, 2014 Jan;24(1):25-30.
    PMID: 24239058 DOI: 10.1016/j.nmd.2013.09.013
    Most evidence supporting the benefit of thymectomy in juvenile myasthenia gravis (JMG) is extrapolated from adult studies, with only little data concerning paediatric populations. Here we evaluate the outcome of children with generalized JMG who underwent thymectomy between 1996 and 2010 at 2 tertiary paediatric neurology referral centres in the United Kingdom. Twenty patients (15 female, 5 male), aged 13months to 15.5years (median 10.4years) at disease onset, were identified. Prior to thymectomy, disease severity was graded as IIb in 3, III in 11, and IV in 6 patients according to the Osserman classification. All demonstrated positive anti-acetylcholine receptor (AChR) antibody titres. All patients received pyridostigmine and 14 received additional steroid therapy. Transternal thymectomy was performed at the age of 2.7-16.6years (median 11.1years). At the last follow-up (10months to 10.9years, median 2.7years, after thymectomy), the majority of children demonstrated substantial improvement, although some had required additional immune-modulatory therapies. About one third achieved complete remission. The postoperative morbidity was low. No benefit was observed in one patient with thymoma. We conclude that thymectomy should be considered as a treatment option early in the course of generalised AChR antibody-positive JMG.
    Matched MeSH terms: Receptors, Cholinergic/immunology*
  3. Unraveling the Role of Receptor for Advanced Glycation End Products (RAGE) and Its Ligands in Myasthenia Gravis
    Angelopoulou E, Paudel YN, Piperi C
    ACS Chem Neurosci, 2020 03 04;11(5):663-673.
    PMID: 32017530 DOI: 10.1021/acschemneuro.9b00678
    Myasthenia gravis (MG) is an autoimmune T cell-dependent B cell-mediated disorder of the neuromuscular junction (NMJ) characterized by fluctuating skeletal muscle weakness, most commonly attributed to pathogenic autoantibodies against postsynaptic nicotinic acetylcholine receptors (AChRs). Although MG pathogenesis is well-documented, there are no objective biomarkers that could effectively correlate with disease severity or MG clinical subtypes, and current treatment approaches are often ineffective. The receptor for advanced glycation end products (RAGE) is a multiligand cell-bound receptor highly implicated in proinflammatory responses and autoimmunity. Preclinical evidence demonstrates that RAGE and its ligand S100B are upregulated in rat models of experimental autoimmune myasthenia gravis (EAMG). S100B-mediated RAGE activation has been shown to exacerbate EAMG, by enhancing T cell proinflammatory responses, aggravating T helper (Th) subset imbalance, increasing AChR-specific T cell proliferative capacity, and promoting the production of antibodies against AChRs from the spleen. Soluble sRAGE and esRAGE, acting as decoys of RAGE ligands, are found to be significantly reduced in MG patients. Moreover, MG has been associated with increased serum levels of S100A12, S100B and HMGB1. Several studies have shown that the presence of thymic abnormalities, the onset age of MG, and the duration of the disease may affect the levels of these proteins in MG patients. Herein, we discuss the emerging role of RAGE and its ligands in MG immunopathogenesis, their clinical significance as promising biomarkers, as well as the potential therapeutic implications of targeting RAGE signaling in MG treatment.
    Matched MeSH terms: Receptors, Cholinergic*
  4. Delay and misdiagnosis in adult myasthenia gravis: A case report
    Kwa, Siew Kim, Zainab Abdul Majeed, Tan, Kah Nian
    International e-Journal of Science, Medicine & Education, 2016;10(3):37-39.
    MyJurnal
    Myasthenia gravis (MG) is a rare autoimmune disorder
    characterised by fluctuating and variable combination
    of muscle weakness and fatigue. Most cases are due to
    T-cell mediated autoantibodies against post-synaptic
    acetylcholine receptors (AChR-Ab), thus preventing
    acetylcholine from binding and signalling skeletal
    muscle to contract.1
    The annual incidence is 7-23 new cases per million.1
    It can occur at any age but with two peaks; an earlyonset
    (20-40 years) female-predominant and a late-onset
    (60-80 years) male-predominant peak. MG is classified
    into ocular and generalised (80%). More than half the
    patients initially present with ptosis and diplopia but half
    will progress to generalised disease with involvement of
    bulbar, limb and respiratory weakness. Those presenting
    as generalised MG can also develop eye signs later.1
    It is important to recognise MG early because it is
    highly treatable. Untreated disease leads to permanent
    weakness.2 Treatment reduces mortality from lifethreatening
    myasthenic crisis.1,3 Misdiagnosis leads to
    potentially harmful interventions and inappropriate
    management.4,5 Diagnosis in late-onset MG is easily
    missed2,3,4,5 because of overlapping symptoms with
    other diseases common in the elderly. We report a case
    of delay and misdiagnosis in an elderly patient with
    co-morbidities. (Copied from article).
    Matched MeSH terms: Receptors, Cholinergic
  5. Total isoflavones from soybean and tempeh reversed scopolamine-induced amnesia, improved cholinergic activities and reduced neuroinflammation in brain
    Ahmad A, Ramasamy K, Jaafar SM, Majeed AB, Mani V
    Food Chem Toxicol, 2014 Mar;65:120-8.
    PMID: 24373829 DOI: 10.1016/j.fct.2013.12.025
    The present study was undertaken to compare the neuroprotective effects between total isoflavones from soybean and tempeh against scopolamine-induced cognitive dysfunction. Total isoflavones (10, 20 and 40mg/kg) from soybean (SI) and tempeh (TI) were administered orally to different groups of rats (n=6) for 15days. Piracetam (400mg/kg, p.o.) was used as a standard drug while scopolamine (1mg/kg, i.p.) was used to induce amnesia in the animals. Radial arm and elevated plus mazes served as exteroceptive behavioural models to measure memory. Brain cholinergic activities (acetylcholine and acetylcholinesterase) and neuroinflammatory activities (COX-1, COX-2, IL-1β and IL10) were also assessed. Treatment with SI and TI significantly reversed the scopolamine effect and improved memory with TI group at 40mg/kg, p.o. exhibiting the best improvement (p<0.001) in rats. The TI (10, 20 and 40mg/kg, p.o.) significantly increased (p<0.001) acetylcholine and reduced acetylcholinesterase levels. Meanwhile, only a high dose (40mg/kg, p.o.) of SI showed significant improvement (p<0.05) in the cholinergic activities. Neuroinflammation study also showed that TI (40mg/kg, p.o.) was able to reduce inflammation better than SI. The TI ameliorates scopolamine-induced memory in rats through the cholinergic neuronal pathway and by prevention of neuroinflammation.
    Matched MeSH terms: Receptors, Cholinergic/metabolism*
  6. Congenital myasthenic syndrome with novel pathogenic variants in the COLQ gene associated with the presence of antibodies to acetylcholine receptors
    Tay CG, Fong CY, Li L, Ganesan V, Teh CM, Gan CS, et al.
    J Clin Neurosci, 2020 Feb;72:468-471.
    PMID: 31831253 DOI: 10.1016/j.jocn.2019.12.007
    Congenital myasthenic syndrome (CMS) is a heterogeneous group of inherited disorder which does not associate with anti-acetylcholine receptor (AChR) antibody. The presence of AChR autoantibody is pathogenic and highly sensitive and specific for autoimmune myasthenia gravis (MG). We describe 2 children from unrelated families who presented with hypotonia, ptosis and fatigability in early infancy with anti-AChR antibodies detected via ELISA on 2 separate occasions in the sera. Both were treated as refractory autoimmune MG due to poor clinical response to acetylcholinesterase inhibitor and immunotherapy. In view of the atypical clinical features, genetic studies of CMS were performed and both were confirmed to have novel pathogenic mutations in the COLQ gene. To the best of our knowledge, the presence of anti-AChR antibody in COLQ-related CMS has never been reported in the literature. The clinical presentation of early onset phenotype, and refractoriness to acetylcholinesterase inhibitor and immunotherapy should prompt CMS as a differential diagnosis.
    Matched MeSH terms: Receptors, Cholinergic*
  7. "Mummy, my eyelids are heavy": A case series of juvenile myasthenia gravis
    Krishna L, Abdul Jalil NF, Lott PW, Singh S, Choo MM
    Eur J Ophthalmol, 2021 Mar;31(2):NP119-NP122.
    PMID: 31390886 DOI: 10.1177/1120672119867605
    PURPOSE: To report three cases of juvenile myasthenia gravis aged between 18 and 24 months with ocular symptoms as their first presentation.

    METHOD: A case series.

    RESULTS: We present a case series of juvenile myasthenia gravis in a tertiary centre in Malaysia. Two of the three cases consist of a pair of twins who presented with ptosis of bilateral eyes; the first twin presented 4 months later than the second twin. These two cases were positive for anti-acetylcholine receptor antibodies and had generalized myasthenia gravis, whereas the other case was negative for receptor antibodies and was purely ocular myasthenia gravis.

    CONCLUSION: Juvenile myasthenia gravis is relatively rare in toddlers. Early diagnosis and commencement of treatment is important to slow the progression of the disease and avoiding life-threatening events.

    Matched MeSH terms: Receptors, Cholinergic/immunology
  8. Fulltext Intracellular stored calcium plays a minor role in Gq-coupled receptor-mediated contraction in rat airway smooth muscle
    Govindaraju, Kayatri, Lee, Mei Kee, Mbaki, Yvonne, Ting, Kang Nee
    Life Sciences, Medicine and Biomedicine, 2018;2(2):1-6.
    MyJurnal
    The general notion of activation of Gq-protein coupled receptors (GPCR) involves the mobilisation of stored and extracellular calcium and leads to smooth muscle tissue contraction. The aim of this study was to investigate the involvement of calcium mediated contractions in vascular and airway smooth muscles. Using standard organ bath procedures, aortic and tracheal rings were obtained from 6 to 8 week-old male Sprague Dawley rats. To activate the Gq protein receptors, phenylephrine (PE), an α1-adrenoceptor agonist, and carbachol, a M3 cholinoceptor agonist was added to baths containing the aortic and tracheal rings, respectively. The maximum response (Emax) to PE was reduced from 158.8 ± 11.8% (n=6) to 62.5 ± 12.4 % (n=8) upon removal of extracellular calcium in Krebs-Ringer solution. Maximal response to PE was also suppressed in the presence of nifedipine, a L-type Ca2+ channel inhibitor, (70.3 ± 11 %, n=8) and SKF96365, a canonical transient receptor potential cation channel inhibitor, (26.7 ± 13.2 %, n=5) when the influx of extracellular calcium was blocked. Removal of stored calcium also attenuated the PE contraction (p0.05). From these observations, we conclude that the role of stored and extracellular calcium in Gq protein activation is not the same across different types of smooth muscle tissues.
    Matched MeSH terms: Receptors, Cholinergic
  9. Fulltext Cold allodynia as the presenting symptom in a case of acquired neuromyotonia (Isaacs syndrome) with multiple autoantibodies
    Goh KJ, Abdullah S, Wong WF, Yeap SS, Shahrizaila N, Tan CT
    Neurology Asia, 2014;19(4):409-412.
    MyJurnal
    We report a patient who presented with severe cold-induced allodynia and hyperhidrosis, and found to have acquired neuromyotonia (Isaacs syndrome) with high voltage-gated potassium channel (VGKC) antibody titre,positive contactin-associated protein 2 (CASPR2) and leucine-rich glioma-inactivated 1 (LGI1) antibodies. The patient also had positive anti-dsDNA and acetylcholine receptor (AChR) antibodies without clinical features of SLE or myasthenia gravis, suggesting a strong underlying autoimmune tendency. CT thorax showed no thymoma. Her symptoms improved with intravenous immunoglobulin infusion but recurred despite maintenance oral corticosteroids and carbamazepine. She has since been on regular IVIG infusions. Cold allodynia is an unusual presentation in acquired neuromyotonia.
    Matched MeSH terms: Receptors, Cholinergic
  10. Fulltext Erectogenic Effects of Clerodendron capitatum: Involvement of Phosphodiesterase Type-5 Inhibition
    Abdelwahab SI, Mohamed AH, Mohamed OY, Oall M, Taha MM, Mohan S, et al.
    Evid Based Complement Alternat Med, 2012;2012:137386.
    PMID: 21747892 DOI: 10.1155/2012/137386
    Clerodendron capitatum (Willd) (family: verbenaceae) is locally named as Gung and used traditionally to treat erectile dysfunction. Therefore, the current study was designed to investigate the erectogenic properties of C. capitatum. The relaxation effect of this plant was tested on phenylephrine precontracted rabbit corpus cavernosum smooth muscle (CCSM). The effects of C. capitatum were also examined on isolated Guinea pig atria alone, in the presence of calcium chloride (Ca(2+) channel blocker), atropine (cholinergic blocker), and glibenclamide (ATP-sensitive K(+) channel blocker). These effects were confirmed on isolated rabbit aortic strips. The extract, when tested colorimetrically for its inhibitory activities on phosphordiesterase-5 (PDE-5) in vitro towards p-nitrophenyl phenyl phosphate (PNPPP), was observed to induce significant dose-dependent inhibition of PDE-5, with an ID(50) of 0.161 mg/ml (P < .05). In conclusion, our results suggest that C. capitatum possesses a relaxant effect on CCSM, which is attributable to the inhibition of PDE-5, but not mediated by the release calcium, activation of adrenergic or cholinergic receptors, or the activation of potassium channels.
    Matched MeSH terms: Receptors, Cholinergic
  11. Fulltext Autonomic Nervous System Mediates the Hypotensive Effects of Aqueous and Residual Methanolic Extracts of Syzygium polyanthum (Wight) Walp. var. polyanthum Leaves in Anaesthetized Rats
    Ismail A, Mohamed M, Sulaiman SA, Wan Ahmad WA
    Evid Based Complement Alternat Med, 2013;2013:716532.
    PMID: 24454508 DOI: 10.1155/2013/716532
    Syzygium polyanthum (Wight) Walp. var. polyanthum leaves are consumed as a traditional Malay treatment of hypertension. This study investigates hypotensive potential of aqueous (AESP) and residual methanolic (met-AESP) extracts of S. polyanthum leaves and possible involvement of autonomic receptors. AESP and met-AESP (20 to 100 mg/kg) were intravenously administered into anaesthetized Wistar-Kyoto (WKY) and spontaneously hypertensive (SHR) rats. Blood pressure and heart were monitored for 20 min. AESP and met-AESP induced significant dose-dependent hypotension, but only 100 mg/kg AESP caused mild bradycardia (n = 5). AESP-induced hypotension was more potent than that of met-AESP in WKY. AESP has a faster onset time than that of met-AESP in both WKY and SHR. However, met-AESP-induced hypotension was more sustained than that of AESP in SHR. Blockages of autonomic ganglion and α -adrenergic receptors using hexamethonium and phentolamine (n = 5 for each group) partially attenuated AESP-induced hypotension, suggesting involvement of α -adrenergic receptors. Blockages of autonomic ganglion, β -adrenergic, cholinergic receptors, and nitric oxide production using hexamethonium, propranolol, atropine, and N- ω -nitro-l arginine methyl ester (L-NAME) (n = 5 for each group) partially attenuated met-AESP-induced hypotension, suggesting involvement of β -adrenergic and cholinergic receptors via nitric oxide production.
    Matched MeSH terms: Receptors, Cholinergic
  12. Mechanisms of antidiarrhoeal activity of methanol leaf extract of Combretum hypopilinum diels (combretaceae): Involvement of opioidergic and (α1 and β)-adrenergic pathways
    Ahmad MH, Zezi AU, Anafi SB, Alhassan Z, Mohammed M, Danraka RN
    J Ethnopharmacol, 2021 Apr 06;269:113750.
    PMID: 33359856 DOI: 10.1016/j.jep.2020.113750
    ETHNOPHARMACOLOGICAL RELEVANCE: The plant Combretum hypopilinum Diels (Combretaceae) is used in traditional medicine for the treatment of diarrhoea and other diseases in Africa. Previously, the antidiarrhoeal activity of its methanol leaf extract was reported. However, the mechanism(s) responsible for this activity is yet to be evaluated.

    AIM OF THE STUDY: This study aimed to elucidate the possible mechanism(s) of antidiarrhoeal activity of methanol leaf extract of Combretum hypopilinum (MECH) in mice.

    MATERIALS AND METHODS: Phytochemical screening and acute toxicity study were conducted according to standard methods. Adult mice were orally (p.o) administered distilled water (10 ml/kg), MECH (1000 mg/kg) and loperamide (5 mg/kg). The probable mechanisms of antidiarrhoeal activity of MECH were investigated following pretreatment with naloxone (2 mg/kg, subcutaneously), prazosin (1 mg/kg, s.c), yohimbine (2 mg/kg, intraperitoneally), propranolol (1 mg/kg, i.p), pilocarpine (1 mg/kg, s.c) and isosorbide dinitrate (150 mg/kg, p.o) 30 min before administration of MECH (1000 mg/kg). The mice were then subjected to castor oil-induced intestinal motility test.

    RESULTS: The oral median lethal dose (LD50) of MECH was found to be higher than 5000 mg/kg. There were significant (p 

    Matched MeSH terms: Receptors, Cholinergic/drug effects
Related Terms
Filters
Contact Us

Please provide feedback to Administrator ([email protected])

External Links