title: Elevated brain harmane (1-methyl-9H-pyrido[3,4-b]indole) in essential tremor cases vs. controls.
abstract: BACKGROUND
  Harmane (1-methyl-9H-pyrido[3,4-β]indole), a potent neurotoxin that has tremor-producing properties in animal models, is present in many foods; although we have demonstrated a difference in tissue harmane concentrations in ET cases vs. controls, all work to date has involved blood samples.
  
  
  OBJECTIVE
  We quantified harmane concentrations in human cerebellum, a brain region of particular pathogenic interest in essential tremor (ET), comparing ET to control brains.
  
  
  METHODS
  Cerebellar cortex was snap frozen and stored at -80°C in aliquots for biochemical analyses. Harmane concentration was assessed using high performance liquid chromatography.
  
  
  RESULTS
  Geometric mean brain harmane concentrations (adjusted for postmortem interval [PMI] and freezer time) were higher in ET cases than controls: 1.0824 (95% confidence interval=0.9405-1.2457) vs. 0.8037 (0.6967-0.9272), p=0.004. Geometric mean of brain harmane concentrations (adjusting for PMI and freezer time) was highest in ET cases who reported other relatives with tremor (1.2005 [0.8712-1.6541]), intermediate in ET cases without family history (1.0312 ([0.8879-1.1976]), and both were significantly higher than controls (p=0.02).
  
  
  CONCLUSIONS
  This study provides additional evidence of a possible etiological importance of this toxin in some cases of the human disease ET.
authors.affiliation: GH Sergievsky Center, College of Physicians and Surgeons, Columbia University, New York, NY, USA; Department of Neurology, College of Physicians and Surgeons, Columbia University, New York, NY, USA; Department of Epidemiology, Mailman School of Public Health, Columbia University, New York, NY, USA; Taub Institute for Research on Alzheimer's Disease and the Aging Brain, College of Physicians and Surgeons, Columbia University, New York, NY, USA. Electronic address: EDL2@columbia.edu.
authors.forename: Elan D
authors.initials: ED
authors.lastname: Louis
authors.forename: Pam
authors.initials: P
authors.lastname: Factor-Litvak
authors.forename: Xinhua
authors.initials: X
authors.lastname: Liu
authors.forename: Jean-Paul G
authors.initials: JP
authors.lastname: Vonsattel
authors.forename: Monika
authors.initials: M
authors.lastname: Galecki
authors.forename: Wendy
authors.initials: W
authors.lastname: Jiang
authors.forename: Wei
authors.initials: W
authors.lastname: Zheng
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D016022:Case-Control Studies; D002525:Cerebellar Cortex / Q000737:chemistry*; D020329:Essential Tremor / Q000139:chemically induced*; D005192:Family Health; D005260:Female; D006247:Harmine / Q000031:analogs & derivatives* / Q000032:analysis; D006801:Humans; D008297:Male; D009498:Neurotoxins / Q000032:analysis*
chemical_list: D009498:Neurotoxins; D006247:Harmine; C005010:harman
keywords: Brain; Epidemiology; Essential tremor; Harmane; Pathology; Toxicant
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