title: Nanouric acid or nanocalcium phosphate as central nidus to induce calcium oxalate stone formation: a high-resolution transmission electron microscopy study on urinary nanocrystallites.
abstract: OBJECTIVE
  This study aimed to accurately analyze the relationship between calcium oxalate (CaOx) stone formation and the components of urinary nanocrystallites.
  
  
  METHODS
  High-resolution transmission electron microscopy (HRTEM), selected area electron diffraction, fast Fourier transformation of HRTEM, and energy dispersive X-ray spectroscopy were performed to analyze the components of these nanocrystallites.
  
  
  RESULTS
  The main components of CaOx stones are calcium oxalate monohydrate and a small amount of dehydrate, while those of urinary nanocrystallites are calcium oxalate monohydrate, uric acid, and calcium phosphate. The mechanism of formation of CaOx stones was discussed based on the components of urinary nanocrystallites.
  
  
  CONCLUSIONS
  The formation of CaOx stones is closely related both to the properties of urinary nanocrystallites and to the urinary components. The combination of HRTEM, fast Fourier transformation, selected area electron diffraction, and energy dispersive X-ray spectroscopy could be accurately performed to analyze the components of single urinary nanocrystallites. This result provides evidence for nanouric acid and/or nanocalcium phosphate crystallites as the central nidus to induce CaOx stone formation.
authors.affiliation: Department of Nephrology, the Second Hospital of Xi'an Jiaotong University, Xi'an, People's Republic of China.
authors.forename: Jie
authors.initials: J
authors.lastname: Gao
authors.affiliation: Institute of Biomineralization and Lithiasis Research, Jinan University, Guangzhou, People's Republic of China.
authors.forename: Jun-Fa
authors.initials: JF
authors.lastname: Xue
authors.affiliation: Institute of Biomineralization and Lithiasis Research, Jinan University, Guangzhou, People's Republic of China.
authors.forename: Meng
authors.initials: M
authors.lastname: Xu
authors.affiliation: Department of Nephrology, the Second Hospital of Xi'an Jiaotong University, Xi'an, People's Republic of China.
authors.forename: Bao-Song
authors.initials: BS
authors.lastname: Gui
authors.affiliation: Institute of Biomineralization and Lithiasis Research, Jinan University, Guangzhou, People's Republic of China.
authors.forename: Feng-Xin
authors.initials: FX
authors.lastname: Wang
authors.affiliation: Institute of Biomineralization and Lithiasis Research, Jinan University, Guangzhou, People's Republic of China.
authors.forename: Jian-Ming
authors.initials: JM
authors.lastname: Ouyang
mesh_terms: D002129:Calcium Oxalate / Q000737:chemistry / Q000652:urine; D002130:Calcium Phosphates / Q000737:chemistry* / Q000652:urine*; D006801:Humans; D046529:Microscopy, Electron, Transmission; D053758:Nanoparticles / Q000737:chemistry* / Q000648:ultrastructure*; D014527:Uric Acid / Q000737:chemistry / Q000652:urine*; D014545:Urinary Calculi / Q000737:chemistry* / Q000652:urine*
chemical_list: D002130:Calcium Phosphates; D002129:Calcium Oxalate; D014527:Uric Acid; C020243:calcium phosphate
keywords: EDS; HRTEM; calcium oxalate stones; heterogeneous nucleation; nanocrystallites