title: EPR spectroscopic investigation of psoriatic finger nails.
abstract: BACKGROUND
  Nail lesions are common features of psoriasis and found in almost half of the patients. However, there is no feasible spectroscopic method evaluating changes and severity of nail psoriasis. EPR (electron paramagnetic resonance) might be feasible for evaluating nail conditions in the patients of psoriasis.
  
  
  METHODS
  Finger nails of five cases with nail psoriasis, (three females and two males) were examined. Nail samples were subjected to the EPR assay. The small piece of the finger nail (1.5 × 5 mm(2)) was incubated in ~50 μM 5-DSA (5-doxylstearic acid) aqueous solutions for about 60 min at 37°C. After rinsing and wiping off the excess 5-DSA solution, the nail samples were measured by EPR.
  
  
  RESULTS
  EPR spectra were analyzed using the intensity ratio (Fast/Slow) of the two motions at the peaks of the lower magnetic field. We observed two distinguishable sites on the basis of the EPR results. In addition, the modern EPR calculation was performed to analyze the spectra obtained. The nail psoriasis-related region is 2~3 times higher than that of the control.
  
  
  CONCLUSIONS
  The present EPR results show that there are two distinguishable sites in the nail. In the case of nail psoriasis, the fragile components are 2~3 times more than those of the control. Thus, the EPR method is thought to be a novel and reliable method of evaluating the nail psoriasis.
authors.affiliation: Department of Radiological Life Sciences, Graduate School of Health Sciences, Hirosaki University, 66-1 Hon-cyo, Hirosaki, 036-8564, Japan.
authors.forename: Kouichi
authors.initials: K
authors.lastname: Nakagawa
authors.forename: Satoko
authors.initials: S
authors.lastname: Minakawa
authors.forename: Daisuke
authors.initials: D
authors.lastname: Sawamura
mesh_terms: D000368:Aged; D003497:Cyclic N-Oxides; D004578:Electron Spin Resonance Spectroscopy / Q000295:instrumentation / Q000379:methods* / Q000592:standards; D005240:Feasibility Studies; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D008954:Models, Biological; D009260:Nail Diseases / Q000175:diagnosis* / Q000473:pathology; D009262:Nails / Q000473:pathology*; D011565:Psoriasis / Q000175:diagnosis* / Q000473:pathology; D015203:Reproducibility of Results; D012720:Severity of Illness Index
chemical_list: D003497:Cyclic N-Oxides; C005072:5-doxylstearic acid
keywords: EPR; ESR; finger nail; nail psoriasis; severity index; simulation; structure