title: Quantitative analysis of cyclooxygenase 2 in the posterior longitudinal ligament of cervical spondylotic myelopathy.
abstract: BACKGROUND
  Cervical spondylotic myelopathy (CSM), in part, results from degeneration of the posterior longitudinal ligament (PLL), which mechanically compresses the spinal cord. Much research was done on the ossification of PLL, but not concerning the non-ossifying degeneration of cervical PLL. The degeneration of cervical PLL may be related to inflammation. The aim of this study was to elucidate the pathological features of the PLL and the role of cyclooxygenase 2 (COX-2) in the degeneration of the PLL in CSM.
  
  
  METHODS
  A total of 23 PLL specimens were collected during surgery from patients with CSM for the histological and immunohistochemical (type II collagen and Ki-67) study. For the control group 14 cervical PLL autopsy specimens were investigated in the same manner. mRNA expression of COX-2 was quantitatively measured by real-time reverse transcription-polymerase chain reaction (RT-PCR) from 18 PLL specimens of patients with CSM and 18 PLL specimens of autopsy cases. Immunohistochemistry was used to evaluate the cellular location of COX-2 in PLL.
  
  
  RESULTS
  A distinct amount of fibrotic area, chondrometaplastic tissue and calcification were found in the PLL of the patient group, compared with the control group. Type II collagen was apparent around chondrometaplastic cells. Ki-67 positive reaction was less than 5%. A COX-2 positive reaction was found in 9 of the patient specimens (39.1%) in which the COX-2 was released from vascular endothelial cells in the PLL. However, such reactions were not found in the control group. Real-time PCR showed that the mRNA expression level of COX-2 in the patient group was significantly higher than that in the control group (P < 0.01).
  
  
  CONCLUSIONS
  Chondrometaplastic tissue producing type II collagen was identified as the most predominant pathological feature in the degenerative PLL. The higher expression of COX-2 might be related to degeneration of the PLL in CSM.
authors.affiliation: Department of Orthopaedics, Xuanwu Hospital, Capital Medical University, Beijing 100053, China.
authors.forename: Hong-Xing
authors.initials: HX
authors.lastname: Song
authors.forename: Michael
authors.initials: M
authors.lastname: Scarpatetti
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Kreil
authors.forename: Hui-Liang
authors.initials: HL
authors.lastname: Shen
authors.forename: Koppany
authors.initials: K
authors.lastname: Bodo
authors.forename: Birgit
authors.initials: B
authors.lastname: Ebner
authors.forename: Heribert
authors.initials: H
authors.lastname: Schröttner
authors.forename: Michael
authors.initials: M
authors.lastname: Mokry
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002574:Cervical Vertebrae / Q000201:enzymology* / Q000473:pathology; D024043:Collagen Type II / Q000378:metabolism; D051546:Cyclooxygenase 2 / Q000235:genetics / Q000378:metabolism*; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D019394:Ki-67 Antigen / Q000378:metabolism; D017846:Longitudinal Ligaments / Q000378:metabolism*; D008875:Middle Aged; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013117:Spinal Cord Compression / Q000201:enzymology*; D055009:Spondylosis / Q000201:enzymology*
chemical_list: D024043:Collagen Type II; D019394:Ki-67 Antigen; D051546:Cyclooxygenase 2; C496540:PTGS2 protein, human