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Adler BL, Chung T, Rowe PC, Aucott J. Dysautonomia following Lyme disease: a key component of post-treatment Lyme disease syndrome? Front Neurol 2024; 15:1344862. [PMID: 38390594 PMCID: PMC10883079 DOI: 10.3389/fneur.2024.1344862] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2023] [Accepted: 01/22/2024] [Indexed: 02/24/2024] Open
Abstract
Dysautonomia, or dysfunction of the autonomic nervous system (ANS), may occur following an infectious insult and can result in a variety of debilitating, widespread, and often poorly recognized symptoms. Dysautonomia is now widely accepted as a complication of COVID-19 and is an important component of Post-Acute Sequelae of COVID-19 (PASC or long COVID). PASC shares many overlapping clinical features with other infection-associated chronic illnesses including Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS) and Post-Treatment Lyme Disease Syndrome (PTLDS), suggesting that they may share common underlying mechanisms including autonomic dysfunction. Despite the recognition of this complication of Lyme disease in the care of patients with PTLD, there has been a scarcity of research in this field and dysautonomia has not yet been established as a complication of Lyme disease in the medical literature. In this review, we discuss the evidence implicating Borrelia burgdorferi as a cause of dysautonomia and the related symptoms, propose potential pathogenic mechanisms given our knowledge of Lyme disease and mechanisms of PASC and ME/CFS, and discuss the diagnostic evaluation and treatments of dysautonomia. We also outline gaps in the literature and priorities for future research.
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Affiliation(s)
- Brittany L Adler
- Division of Rheumatology, Johns Hopkins University, Baltimore, MD, United States
| | - Tae Chung
- Department of Physical Medicine and Rehabilitation, Johns Hopkins University, Baltimore, MD, United States
| | - Peter C Rowe
- Department of Pediatrics, Johns Hopkins University, Baltimore, MD, United States
| | - John Aucott
- Division of Rheumatology, Johns Hopkins University, Baltimore, MD, United States
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Vernino S, Bourne KM, Stiles LE, Grubb BP, Fedorowski A, Stewart JM, Arnold AC, Pace LA, Axelsson J, Boris JR, Moak JP, Goodman BP, Chémali KR, Chung TH, Goldstein DS, Diedrich A, Miglis MG, Cortez MM, Miller AJ, Freeman R, Biaggioni I, Rowe PC, Sheldon RS, Shibao CA, Systrom DM, Cook GA, Doherty TA, Abdallah HI, Darbari A, Raj SR. Postural orthostatic tachycardia syndrome (POTS): State of the science and clinical care from a 2019 National Institutes of Health Expert Consensus Meeting - Part 1. Auton Neurosci 2021; 235:102828. [PMID: 34144933 DOI: 10.1016/j.autneu.2021.102828] [Citation(s) in RCA: 114] [Impact Index Per Article: 38.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2021] [Revised: 05/10/2021] [Accepted: 05/30/2021] [Indexed: 12/13/2022]
Abstract
Postural orthostatic tachycardia syndrome (POTS) is a chronic and often disabling disorder characterized by orthostatic intolerance with excessive heart rate increase without hypotension during upright posture. Patients often experience a constellation of other typical symptoms including fatigue, exercise intolerance and gastrointestinal distress. A typical patient with POTS is a female of child-bearing age, who often first displays symptoms in adolescence. The onset of POTS may be precipitated by immunological stressors such as a viral infection. A variety of pathophysiologies are involved in the abnormal postural tachycardia response; however, the pathophysiology of the syndrome is incompletely understood and undoubtedly multifaceted. Clinicians and researchers focused on POTS convened at the National Institutes of Health in July 2019 to discuss the current state of understanding of the pathophysiology of POTS and to identify priorities for POTS research. This article, the first of two articles summarizing the information discussed at this meeting, summarizes the current understanding of this disorder and best practices for clinical care. The evaluation of a patient with suspected POTS should seek to establish the diagnosis, identify co-morbid conditions, and exclude conditions that could cause or mimic the syndrome. Once diagnosed, management typically begins with patient education and non-pharmacologic treatment options. Various medications are often used to address specific symptoms, but there are currently no FDA-approved medications for the treatment of POTS, and evidence for many of the medications used to treat POTS is not robust.
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Affiliation(s)
- Steven Vernino
- Department of Neurology, UT Southwestern Medical Center, Dallas, TX, USA
| | - Kate M Bourne
- Department of Cardiac Sciences, Libin Cardiovascular Institute, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada
| | - Lauren E Stiles
- Department of Neurology, Stony Brook University Renaissance School of Medicine, Stony Brook, NY, USA; Dysautonomia International, East Moriches, NY, USA
| | - Blair P Grubb
- Division of Cardiology, Department of Medicine, The University of Toledo Medical Center, USA
| | - Artur Fedorowski
- Department of Clinical Sciences, Lund University, Malmö, Sweden; Department of Cardiology, Skåne University Hospital, Malmö, Sweden
| | - Julian M Stewart
- Center for Hypotension, Departments of Pediatrics and Physiology, New York Medical College, Valhalla, NY, USA
| | - Amy C Arnold
- Department of Neural and Behavioral Sciences, Pennsylvania State University College of Medicine, Hershey, PA, USA; Autonomic Dysfunction Center, Division of Clinical Pharmacology, Department of Medicine, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Laura A Pace
- Center for Genomic Medicine and Department of Pediatrics, Division of Medical Genetics and Genomics, University of Utah, Salt Lake City, UT, USA
| | - Jonas Axelsson
- Department of Clinical Immunology, Karolinska University Hospital, Stockholm, Sweden
| | | | - Jeffrey P Moak
- Department of Pediatrics, George Washington Univeristy School of Medicine and Health Sciences, Washington, DC, USA
| | - Brent P Goodman
- Neuromuscular Division, Department of Neurology, Mayo Clinic, Scottsdale, AZ, USA
| | - Kamal R Chémali
- Department of Neurology, Eastern Virginia Medical School, Division of Neurology, Neuromuscular and Autonomic Center, Sentara Healthcare, Norfolk, VA, USA
| | - Tae H Chung
- Department of Physical Medicine and Rehabilitation, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - David S Goldstein
- Autonomic Medicine Section, Clinical Neurosciences Program, Division of Intramural Research, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD, USA
| | - Andre Diedrich
- Autonomic Dysfunction Center, Division of Clinical Pharmacology, Department of Medicine and Biomedical Engineering, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Mitchell G Miglis
- Department of Neurology and Neurological Sciences, Stanford University School of Medicine, Palo Alto, CA, USA
| | - Melissa M Cortez
- Department of Neurology, University of Utah, Salt Lake City, UT, USA
| | - Amanda J Miller
- Department of Neural and Behavioral Sciences, Pennsylvania State University College of Medicine, Hershey, PA, USA
| | - Roy Freeman
- Department of Neurology, Harvard Medical School, Boston, MA, USA; Center for Autonomic and Peripheral Nerve Disorders, Beth Israel Deaconess Medical Center, Boston, MA, USA
| | - Italo Biaggioni
- Autonomic Dysfunction Center, Division of Clinical Pharmacology, Departments of Medicine and Pharmacology, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Peter C Rowe
- Department of Pediatrics, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Robert S Sheldon
- Department of Cardiac Sciences, Libin Cardiovascular Institute, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada
| | - Cyndya A Shibao
- Autonomic Dysfunction Center, Division of Clinical Pharmacology, Departments of Medicine, Vanderbilt University Medical Center, Nashville, TN, USA
| | - David M Systrom
- Pulmonary and Critical Care Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA
| | - Glen A Cook
- Department of Neurology, Uniformed Services University, Bethesda, MD, USA
| | - Taylor A Doherty
- Division of Rheumatology, Allergy, and Immunology, Department of Medicine, University of California at San Diego, La Jolla, CA, USA
| | | | - Anil Darbari
- Pediatric Gastroenterology, Children's National Hospital, Department of Pediatrics, George Washington University School of Medicine and Health Sciences, Washington, DC, USA
| | - Satish R Raj
- Department of Cardiac Sciences, Libin Cardiovascular Institute, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada; Autonomic Dysfunction Center, Division of Clinical Pharmacology, Department of Medicine, Vanderbilt University Medical Center, Nashville, TN, USA.
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Cutsforth-Gregory JK, Sandroni P. Clinical neurophysiology of postural tachycardia syndrome. HANDBOOK OF CLINICAL NEUROLOGY 2019; 161:429-445. [PMID: 31307619 DOI: 10.1016/b978-0-444-64142-7.00066-7] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Postural tachycardia syndrome (POTS) is one of several disorders of orthostatic intolerance (OI). It is defined by the development of symptoms of cerebral hypoperfusion or sympathetic activation and a sustained heart rate increment of 30 beats/min or more (40 beats/min for teenagers) within 10min of standing or head-up tilt in the absence of orthostatic hypotension; the standing heart rate is often 120 beats/min or higher. POTS is approximately five times more common in women than men. This heterogeneous syndrome is caused by several pathophysiologic mechanisms (limited autonomic neuropathy, hyperadrenergic state, hypovolemia, venous pooling, deconditioning), which are not mutually exclusive. Anxiety and somatic hypervigilance play significant roles in POTS. Common comorbidities include visceral pain and dysmotility, chronic fatigue and fibromyalgia, migraine, joint hypermobility, mitral valve prolapse, and inappropriate sinus tachycardia. Patients with suspected POTS should undergo comprehensive cardiac and neurologic examinations and autonomic and laboratory tests to determine the most likely pathophysiologic basis of OI. The objectives of POTS management are to (1) increase the time that patients can stand, perform daily activities, and exercise and (2) avoid syncope. Management involves nonpharmacologic (fluid and salt loading, physical countermaneuvers, compression garments, exercise training) and pharmacologic (β-blockers, pyridostigmine, fludrocortisone, midodrine) approaches.
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Affiliation(s)
| | - Paola Sandroni
- Department of Neurology, Mayo Clinic, Rochester, MN, United States.
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Benarroch EE. Postural tachycardia syndrome: a heterogeneous and multifactorial disorder. Mayo Clin Proc 2012; 87:1214-25. [PMID: 23122672 PMCID: PMC3547546 DOI: 10.1016/j.mayocp.2012.08.013] [Citation(s) in RCA: 243] [Impact Index Per Article: 20.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/02/2012] [Revised: 08/28/2012] [Accepted: 08/28/2012] [Indexed: 02/07/2023]
Abstract
Postural tachycardia syndrome (POTS) is defined by a heart rate increment of 30 beats/min or more within 10 minutes of standing or head-up tilt in the absence of orthostatic hypotension; the standing heart rate is often 120 beats/min or higher. POTS manifests with symptoms of cerebral hypoperfusion and excessive sympathoexcitation. The pathophysiology of POTS is heterogeneous and includes impaired sympathetically mediated vasoconstriction, excessive sympathetic drive, volume dysregulation, and deconditioning. POTS is frequently included in the differential diagnosis of chronic unexplained symptoms, such as inappropriate sinus tachycardia, chronic fatigue, chronic dizziness, or unexplained spells in otherwise healthy young individuals. Many patients with POTS also report symptoms not attributable to orthostatic intolerance, including those of functional gastrointestinal or bladder disorders, chronic headache, fibromyalgia, and sleep disturbances. In many of these cases, cognitive and behavioral factors, somatic hypervigilance associated with anxiety, depression, and behavioral amplification contribute to symptom chronicity. The aims of evaluation in patients with POTS are to exclude cardiac causes of inappropriate tachycardia; elucidate, if possible, the most likely pathophysiologic basis of postural intolerance; assess for the presence of treatable autonomic neuropathies; exclude endocrine causes of a hyperadrenergic state; evaluate for cardiovascular deconditioning; and determine the contribution of emotional and behavioral factors to the patient's symptoms. Management of POTS includes avoidance of precipitating factors, volume expansion, physical countermaneuvers, exercise training, pharmacotherapy (fludrocortisone, midodrine, β-blockers, and/or pyridostigmine), and behavioral-cognitive therapy. A literature search of PubMed for articles published from January 1, 1990, to June 15, 2012, was performed using the following terms (or combination of terms): POTS; postural tachycardia syndrome, orthostatic; orthostatic; syncope; sympathetic; baroreceptors; vestibulosympathetic; hypovolemia; visceral pain; chronic fatigue; deconditioning; headache; Chiari malformation; Ehlers-Danlos; emotion; amygdala; insula; anterior cingulate; periaqueductal gray; fludrocortisone; midodrine; propranolol; β-adrenergic; and pyridostigmine. Studies were limited to those published in English. Other articles were identified from bibliographies of the retrieved articles.
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Adlam D, Herring N, Douglas G, De Bono JP, Li D, Danson EJ, Tatham A, Lu CJ, Jennings KA, Cragg SJ, Casadei B, Paterson DJ, Channon KM. Regulation of β-adrenergic control of heart rate by GTP-cyclohydrolase 1 (GCH1) and tetrahydrobiopterin. Cardiovasc Res 2012; 93:694-701. [PMID: 22241166 PMCID: PMC3291091 DOI: 10.1093/cvr/cvs005] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/09/2011] [Revised: 12/23/2011] [Accepted: 01/06/2012] [Indexed: 02/05/2023] Open
Abstract
AIMS Clinical markers of cardiac autonomic function, such as heart rate and response to exercise, are important predictors of cardiovascular risk. Tetrahydrobiopterin (BH4) is a required cofactor for enzymes with roles in cardiac autonomic function, including tyrosine hydroxylase and nitric oxide synthase. Synthesis of BH4 is regulated by GTP cyclohydrolase I (GTPCH), encoded by GCH1. Recent clinical studies report associations between GCH1 variants and increased heart rate, but the mechanistic importance of GCH1 and BH4 in autonomic function remains unclear. We investigate the effect of BH4 deficiency on the autonomic regulation of heart rate in the hph-1 mouse model of BH4 deficiency. METHODS AND RESULTS In the hph-1 mouse, reduced cardiac GCH1 expression, GTPCH enzymatic activity, and BH4 were associated with increased resting heart rate; blood pressure was not different. Exercise training decreased resting heart rate, but hph-1 mice retained a relative tachycardia. Vagal nerve stimulation in vitro induced bradycardia equally in hph-1 and wild-type mice both before and after exercise training. Direct atrial responses to carbamylcholine were equal. In contrast, propranolol treatment normalized the resting tachycardia in vivo. Stellate ganglion stimulation and isoproterenol but not forskolin application in vitro induced a greater tachycardic response in hph-1 mice. β1-adrenoceptor protein was increased as was the cAMP response to isoproterenol stimulation. CONCLUSION Reduced GCH1 expression and BH4 deficiency cause tachycardia through enhanced β-adrenergic sensitivity, with no effect on vagal function. GCH1 expression and BH4 are novel determinants of cardiac autonomic regulation that may have important roles in cardiovascular pathophysiology.
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Affiliation(s)
- David Adlam
- Department of Cardiovascular Medicine, University of Oxford, John Radcliffe Hospital, Oxford OX3 9DU, UK
| | - Neil Herring
- Department of Physiology, Anatomy & Genetics Sherrington Building University of Oxford, Parks Road, Oxford OX1 3PT, UK
| | - Gillian Douglas
- Department of Cardiovascular Medicine, University of Oxford, John Radcliffe Hospital, Oxford OX3 9DU, UK
| | - Joseph P. De Bono
- Department of Cardiovascular Medicine, University of Oxford, John Radcliffe Hospital, Oxford OX3 9DU, UK
| | - Dan Li
- Department of Physiology, Anatomy & Genetics Sherrington Building University of Oxford, Parks Road, Oxford OX1 3PT, UK
| | - Edward J. Danson
- Department of Physiology, Anatomy & Genetics Sherrington Building University of Oxford, Parks Road, Oxford OX1 3PT, UK
| | - Amy Tatham
- Department of Cardiovascular Medicine, University of Oxford, John Radcliffe Hospital, Oxford OX3 9DU, UK
| | - Cheih-Ju Lu
- Department of Physiology, Anatomy & Genetics Sherrington Building University of Oxford, Parks Road, Oxford OX1 3PT, UK
| | - Katie A. Jennings
- Department of Physiology, Anatomy & Genetics Sherrington Building University of Oxford, Parks Road, Oxford OX1 3PT, UK
| | - Stephanie J. Cragg
- Department of Cardiovascular Medicine, University of Oxford, John Radcliffe Hospital, Oxford OX3 9DU, UK
| | - Barbara Casadei
- Department of Cardiovascular Medicine, University of Oxford, John Radcliffe Hospital, Oxford OX3 9DU, UK
| | - David J. Paterson
- Department of Physiology, Anatomy & Genetics Sherrington Building University of Oxford, Parks Road, Oxford OX1 3PT, UK
| | - Keith M. Channon
- Department of Cardiovascular Medicine, University of Oxford, John Radcliffe Hospital, Oxford OX3 9DU, UK
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Wittwer ED, Liu Z, Warner ND, Schroeder DR, Nadeau AM, Allen AR, Murillo CJ, Elvebak RL, Aakre BM, Eisenach JH. β-1 and β-2 adrenergic receptor polymorphism and association with cardiovascular response to orthostatic screening. Auton Neurosci 2011; 164:89-95. [PMID: 21807569 DOI: 10.1016/j.autneu.2011.07.004] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2010] [Revised: 06/08/2011] [Accepted: 07/10/2011] [Indexed: 10/17/2022]
Abstract
Variation in the beta-1 and beta-2 adrenergic receptor genes (ADRB1 and ADRB2, respectively) may influence cardiovascular reactivity including orthostatic stress. We tested this hypothesis in a head-up tilt (HUT) screening protocol in healthy young adults without history of syncope. Following brachial arterial catheter insertion, 120 subjects (age 18-40, 72 females, Caucasian) underwent 5min 60° HUT. Polymorphisms tested were: Ser49/Gly and Arg389/Gly in ADRB1; and Arg16/Gly, Gln27/Glu, and Thr164/Ile in ADRB2. Three statistical models (recessive, dominant, additive) were evaluated using general linear models with analysis for each physiologic variable. A recessive model demonstrated a significant association between Arg16/Gly and: absolute supine and upright HR; HUT-induced change in cardiac index (CI), stroke index (SI) and systemic vascular resistance (SVR); and supine and upright norepinephrine values. Blood pressure was not influenced by genotype. Fewer associations were present for other polymorphisms: Ser49/Gly and the change in SI (dominant model), and Arg389/Gly and supine and HUT norepinephrine (additive model). We conclude that in this population, there is a robust association between Arg16/Gly and HUT responses, such that 2 copies of Arg16 increase supine and upright HR, and greater HUT-induced decreases in CI and SI, with greater increases in SVR and norepinephrine. ADRB1 gene variation appears to impact SI and plasma NE levels but not HR. Whether ADRB2 gene variation is ultimately disease-causing or disease-modifying, this study suggests an association between Arg16/Gly and postural hemodynamics, with sympathetic noradrenergic activity affected in a similar direction. This may have implications in the development of orthostatic disorders.
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Affiliation(s)
- E D Wittwer
- Department of Anesthesiology, Mayo Clinic, Rochester, MN, USA.
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7
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Fontenele JB, Félix FHC. Fibromyalgia and Related Medically Unexplained Symptoms: A Lost Link Between Cardiovascular and Nociception Modulation. ACTA ACUST UNITED AC 2009. [DOI: 10.1080/10582450802679904] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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8
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Tanaka H, Fujita Y, Takenaka Y, Kajiwara S, Masutani S, Ishizaki Y, Matsushima R, Shiokawa H, Shiota M, Ishitani N, Kajiura M, Honda K. Japanese clinical guidelines for juvenile orthostatic dysregulation version 1. Pediatr Int 2009; 51:169-79. [PMID: 19371306 DOI: 10.1111/j.1442-200x.2008.02783.x] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
This clinical practice guideline provides recommendations for the assessment, diagnosis and treatment of school-aged children and juveniles with orthostatic dysregulation (OD), usually named orthostatic intolerance in USA and Europe. This guideline is intended for use by primary care clinicians working in primary care settings. The guideline contains the following recommendations for diagnosis of OD: (i) initial evaluation composed of including and excluding criteria, the assessment of no evidence of other disease including cardiac disease and so on; (ii) a new orthostatic test to determine four different subsets: instantaneous orthostatic hypotension, postural tachycardia syndrome, neurally mediated syncope and delayed orthostatic hypotension; (iii) evaluation of severity; and (iv) judgment of psychosocial background with the use of rating scales. The guideline also contains the following recommendations for treatment of OD on the basis of the result of an orthostatic test in addition to psychosocial assessment: (i) guidance and education for parents and children; (ii) non-pharmacological treatments; (iii) contact with school personnel; (iv) use of adrenoceptor stimulants and other medications; (v) strategies of psychosocial intervention; and (vi) psychotherapy. This clinical practice guideline is not intended as a sole source of guidance in the evaluation of children with OD. Rather, it is designed to assist primary care clinicians by providing a framework for decision making of diagnosis and treatments.
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Affiliation(s)
- Hidetaka Tanaka
- Department of Pediatrics, Osaka Medical College, Takatsuki, Osaka, Japan.
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All that shine is not gold: modelling the true relation between orthostatic intolerance, fibromyalgia and chronic fatigue syndromes. Clin Auton Res 2008; 18:298; author reply 299. [PMID: 18932009 DOI: 10.1007/s10286-008-0498-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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10
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Shih PA, O’Connor D, Mahata S. Human Genomics in Hypertension. Genomics 2008. [DOI: 10.3109/9781420067064-11] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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11
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Shih PAB, O'Connor DT. Hereditary determinants of human hypertension: strategies in the setting of genetic complexity. Hypertension 2008; 51:1456-64. [PMID: 18413494 DOI: 10.1161/hypertensionaha.107.090480] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Affiliation(s)
- Pei-an Betty Shih
- Department of Medicine, Center for Human Genetics and Genomics, University of California at San Diego, and VA San Diego Healthcare System, La Jolla, CA 92093-0838, USA
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Garland EM, Black BK, Harris PA, Robertson D. Dopamine-β-hydroxylase in postural tachycardia syndrome. Am J Physiol Heart Circ Physiol 2007; 293:H684-90. [PMID: 17625104 DOI: 10.1152/ajpheart.01389.2006] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Norepinephrine is frequently elevated in postural tachycardia syndrome (POTS), a syndrome of heterogeneous etiology characterized by a >30 beats/min increase in heart rate with standing. Norepinephrine is synthesized from dopamine by dopamine-β-hydroxylase (DBH). The results of a preliminary study suggested that the T allele frequency of the DBH −1021C→T polymorphism is elevated in POTS. This allele correlates with low DBH activity and might predict reduced serum DBH activity in patients with POTS. To test the hypothesis that low DBH activity and the underlying −1021C→T polymorphism are associated with increased susceptibility to POTS, we measured serum DBH activity in POTS and determined its relationship to the DBH genotype and plasma norepinephrine. Serum DBH was similar for 83 normal volunteers and 42 patients with POTS: median (range) = 22.5 (0.5–94.2) and 19.6 (0.1–68.8) nmol·min−1·ml−1, respectively ( P = 0.282). The genotype frequencies for 254 control and 157 POTS patients were not different between groups (∼63% CC genotype and ∼5% TT genotype, P = 0.319). The T allele associated with lower serum DBH in both groups [control serum DBH = 15.7 (SD 12.3) and 35.1 nmol·min−1·ml−1(SD 18.6) for T carriers and noncarriers, respectively; POTS serum DBH = 8.2 (SD 5.6) and 28.5 nmol·min−1·ml−1(SD 14.7) for T carriers and noncarriers, respectively]. High DBH in POTS was linked to elevated plasma levels of norepinephrine. Although DBH activity and genotype are unlikely to be primary determinants of susceptibility to POTS, differences in DBH activity in POTS may reflect differences in the level of sympathetic activation.
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Affiliation(s)
- Emily M Garland
- Autonomic Dysfunction Center, AA3228 Medical Center North, Vanderbilt University, Nashville, TN 37232-2195, USA.
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13
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Lavi S, Nevo O, Thaler I, Rosenfeld R, Dayan L, Hirshoren N, Gepstein L, Jacob G. Effect of aging on the cardiovascular regulatory systems in healthy women. Am J Physiol Regul Integr Comp Physiol 2007; 292:R788-93. [PMID: 16946083 DOI: 10.1152/ajpregu.00352.2006] [Citation(s) in RCA: 79] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Aging, independently from the hormonal status, is a major risk factor for cardiovascular morbidity in healthy women. Therefore, we studied the effect of healthy aging on the cardiovascular homeostatic mechanisms in premenopausal and postmenopausal women with similar estrogen levels. Twelve healthy postmenopausal women, confirmed by follicular-stimulating hormone (FSH) and luteal hormone (LH) levels, were compared with 14 normally menstruating women during the early follicular phase (young-EF), to avoid as much as possible the effects of estrogen. Systolic BP was 108 ± 1.5 vs. 123 ± 2.5 ( P < 0.001), supine norepinephrine was 260 ± 30 vs. 216 ± 45 and upright 640 ± 100 vs. 395 ± 50 pg/ml ( P = 0.05) in young-EF vs. postmenopausal, respectively. Plasma renin activity and aldosterone remained unchanged. Vagal cardiac tone indices decreased significantly with aging (young-EF vs. postmenopausal): high-frequency (HF) band, root mean square successive differences (rMSSD) and proportion of R-R intervals >50 ms (PNN50%) were 620 ± 140 vs. 270 ± 70 ( P = 0.04), 53 ± 7 vs. 30 ± 3 ( P = 0.02), and 23 ± 5 vs. 10 ± 3 ( P = 0.04), respectively. LF to HF ratio was 0.85 ± 0.17 in young-EF and became 1.5 ± 0.22 in postmenopausal ( P = 0.03). Both arms of the baroreflex, +BRS (29 ± 5 vs. 13.5 ± 2.5, P = 0.01) and −BRS (26 ± 4 vs. 15 ± 1.5, P = 0.02) decreased with aging. Cardiovascular α1-adrenoreceptor responsiveness significantly increased and β-decreased in postmenopausal compared with young EF ( P < 0.001, both). The corrected QT intervals (QTc) were similar, whereas corrected JT intervals (JTc) and JTc to QTc ratio were prolonged in the postmenopausal group. We conclude that in young women, parasympathetic control is the main regulator of the cardiovascular system and in postmenopausal women, sympathetic tone dominates. The transition from parasympathetic to sympathetic control may contribute to the increased cardiovascular morbidity with aging.
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Affiliation(s)
- Shahar Lavi
- J. Recanati Autonomic Dysfunction Center, Medicine A, Rambam Medical Center, Haifa 31096 Israel
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Kimura N. One-step immobilization of poly(dT)-modified DNA onto non-modified plastic substrates by UV irradiation for microarrays. Biochem Biophys Res Commun 2006; 347:477-84. [PMID: 16828708 DOI: 10.1016/j.bbrc.2006.06.130] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2006] [Accepted: 06/22/2006] [Indexed: 01/27/2023]
Abstract
Previously, 'DNattach', an alternative DNA immobilization system for attaching modified oligonucleotide probes onto a gold surface by UV irradiation that can be used in various DNA microarray applications including gene expression analysis, was developed. Attached to the gold surface, the modified probes have been shown to successfully detect synaptogenesis in the developing mouse cerebellum. In this study, this technology to immobilize modified oligonucleotide probes onto three different non-modified plastic surfaces in a microarray format has been further expanded. Using this system, single nucleotide polymorphism (SNP) genotyping of both oligonucleotide and PCR product targets has been successfully performed and it has also been shown that the probes immobilized on the slides can be used efficiently in hybridization experiments. Furthermore, it has been shown that probe concentrations of only 1-5 microM are sufficient for hybridization and that this immobilization method provides hybridization signals greater than those of conventional immobilization techniques.
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Affiliation(s)
- Naoki Kimura
- Research and Development Center, Nisshinbo Industries Inc., 1-2-3 Onodai, Chiba-shi, Chiba 267-0056, Japan.
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