title: A novel oxidative stress marker in patients with Alzheimer's disease: dynamic thiol-disulphide homeostasis.
abstract: OBJECTIVE
  The aim of this study was to evaluate the dynamic thiol-disulphide homeostasis as an oxidative stress parameter, using a newly proposed method, in patients with Alzheimer's disease.
  
  
  METHODS
  In total, 97 participants were included in the study. Among them, 51 had been diagnosed with Alzheimer's disease, and the remaining 46 were healthy individuals. Total thiol (-SH+-S-S-) levels and native thiol (-SH) levels in serum of each participant were measured. The amount of dynamic disulphide bonds (-S-S-) and (-S-S-) ×100/(-SH), (-S-S-) ×100/(-SH+-S-S-), and -SH×100/(-SH+-S-S-) ratios were calculated from these values. The obtained data were used to compare Alzheimer's disease patients with healthy individuals.
  
  
  RESULTS
  The average total thiol and native thiol levels of patient with Alzheimer's disease in the study were found to be significantly lower than those levels of healthy individuals. In addition, in the patient group, the -S-S-×100/-S-S+-SH ratio was found to be significantly higher, whereas the -SH×100/-S-S+-SH ratio was found to be significantly lower compared with healthy individuals. Total thiol and native thiol levels, dynamic disulphide bond amount, and -S-S-×100/-SH, -S-S-×100/-S-S+-SH, and -SH×100/-S-S+-SH ratios were not found to be correlated with mini mental state examination score or duration of disease.
  
  
  CONCLUSIONS
  Recent studies have shown that oxidative stress is the one of the molecular changes underlying the pathogenesis of Alzheimer's disease. In this study, we have investigated the dynamic thiol-disulphide homeostasis in patients with Alzheimer's disease, using a novel method.
authors.affiliation: 1Department of Neurology, Faculty of Medicine,Yıldırım Beyazıt University,Ankara,Turkey.
authors.forename: Sadiye
authors.initials: S
authors.lastname: Gumusyayla
authors.affiliation: 1Department of Neurology, Faculty of Medicine,Yıldırım Beyazıt University,Ankara,Turkey.
authors.forename: Gonul
authors.initials: G
authors.lastname: Vural
authors.affiliation: 2Department of Neurology,Ankara Atatürk Education and Research Hospital,Ankara,Turkey.
authors.forename: Hesna
authors.initials: H
authors.lastname: Bektas
authors.affiliation: 1Department of Neurology, Faculty of Medicine,Yıldırım Beyazıt University,Ankara,Turkey.
authors.forename: Orhan
authors.initials: O
authors.lastname: Deniz
authors.affiliation: 3Department of Biochemistry,Ankara Atatürk Education and Research Hospital,Ankara,Turkey.
authors.forename: Salim
authors.initials: S
authors.lastname: Neselioglu
authors.affiliation: 4Department of Biochemistry, Faculty of Medicine,Yıldırım Beyazıt University,Ankara,Turkey.
authors.forename: Ozcan
authors.initials: O
authors.lastname: Erel
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000544:Alzheimer Disease / Q000097:blood* / Q000175:diagnosis*; D015415:Biomarkers / Q000378:metabolism; D004220:Disulfides / Q000097:blood*; D005260:Female; D006706:Homeostasis; D006801:Humans; D008297:Male; D008875:Middle Aged; D018384:Oxidative Stress; D013438:Sulfhydryl Compounds / Q000097:blood*
chemical_list: D015415:Biomarkers; D004220:Disulfides; D013438:Sulfhydryl Compounds
keywords: Alzheimer’s disease; dynamic thiol–disulphide homeostasis; oxidative stress; thiol metabolism