title: Acidic and basic solutions dissolve protein plugs made of lithostathine complicating choledochal cyst/pancreaticobiliary maljunction.
abstract: BACKGROUND
  Symptoms of choledochal cysts are caused by protein plugs made of lithostathine, which block the long common channel and increase pancreaticobiliary ductal pressure. Agents that dissolve protein plugs can provide relief from or prevent symptoms. In the present study, drugs reportedly effective for pancreatic and biliary stones were used in dissolution tests.
  
  
  METHODS
  Protein plugs were obtained from choledochal cysts during surgery in two children (5- and 6-year-old girls). Plugs approximately 2 mm in diameter were immersed in citric acid, tartaric acid, dimethadione, bromhexine, dehydrocholic acid, sodium citrate, hydrochloric acid, and sodium hydroxide solutions under observation with a digital microscope. The pH of each solution was measured using a pH meter.
  
  
  RESULTS
  Plugs dissolved in citric acid (5.2 mM; pH 2.64), tartaric acid (6.7 mM; pH 2.51), dimethadione (75 mM; pH 3.70), hydrochloric acid (0.5 mM; pH 3.13), and sodium hydroxide (75 mM; pH 12.75) solutions. Plugs did not dissolve in dimethadione (7.5 mM; pH 4.31), bromhexine (0.1%; pH 4.68), dehydrocholic acid (5%; pH 7.45), and sodium citrate (75 mM; pH 7.23) solutions.
  
  
  CONCLUSIONS
  Protein plugs in choledochal cysts are dissolved in acidic and basic solutions, which may eliminate longitudinal electrostatic interactions of the lithostathine protofibrils.
authors.affiliation: Department of Pediatric Surgery, Nagoya University Graduate School of Medicine, 65 Tsurumai-cho, Showa-ku, Nagoya, 466-8560, Japan. kkaneko@med.nagoya-u.ac.jp
authors.forename: Kenitiro
authors.initials: K
authors.lastname: Kaneko
authors.forename: Yasuyuki
authors.initials: Y
authors.lastname: Ono
authors.forename: Takahisa
authors.initials: T
authors.lastname: Tainaka
authors.forename: Wataru
authors.initials: W
authors.lastname: Sumida
authors.forename: Hisami
authors.initials: H
authors.lastname: Ando
mesh_terms: D000143:Acids; D002648:Child; D002675:Child, Preschool; D049448:Cholangiopancreatography, Magnetic Resonance; D015529:Choledochal Cyst / Q000378:metabolism*; D003135:Common Bile Duct / Q000002:abnormalities* / Q000473:pathology; D004108:Dilatation, Pathologic; D005260:Female; D006801:Humans; D006863:Hydrogen-Ion Concentration; D051847:Lithostathine / Q000032:analysis / Q000187:drug effects*; D010183:Pancreatic Ducts / Q000002:abnormalities*; D011506:Proteins / Q000737:chemistry*; D012997:Solvents / Q000494:pharmacology*; D017550:Spectroscopy, Fourier Transform Infrared
chemical_list: D000143:Acids; D051847:Lithostathine; D011506:Proteins; D012997:Solvents