title: Videodensitometric analysis of advanced carotid plaque: correlation with MMP-9 and TIMP-1 expression.
abstract: BACKGROUND
  Matrix metalloproteinase-9 (MMP-9) and tissue inhibitor of MMP (TIMP) promote derangement of the extracellular matrix, which is ultimately reflected in plaque images seen on ultrasound. Videodensitometry can identify structural disturbances in plaques.
  
  
  OBJECTIVE
  To establish the correlations between values determined using videodensitometry in B-mode ultrasound images of advanced carotid plaques and the total expression of MMP-9 and TIMP-1 in these removed plaques.
  
  
  METHODS
  Thirty patients underwent ultrasonic tissue characterization of carotid plaques before surgery, using mean gray level (MGL), energy, entropy and homogeneity. Each patient was assigned preoperatively to one of 2 groups: group I, symptomatic patients (n = 16; 12 males; mean age 66.7 ± 6.8 years), and group II, asymptomatic patients (n = 14; 8 males; mean age 67.6 ± 6.81 years). Tissue specimens were analyzed for MMP-9 and TIMP-1 expression. Nine carotid arteries were used as normal tissue controls.
  
  
  RESULTS
  MMP-9 expression levels were elevated in group II and in normal tissues compared to group I (p < 0.001). TIMP-1 levels were higher in group II than in group I, and significantly higher in normal tissues than in group I (p = 0.039). The MGL was higher in group II compared to group I (p = 0.038). Energy had greater values in group II compared to group I (p = 0.02). There were no differences between patient groups in homogeneity and entropy. Energy positively correlated with MMP-9 and TIMP-1 expression (p = 0.012 and p = 0.031 respectively). Homogeneity positively correlated with MMP-9 and TIMP-1 expression (p = 0.034 and p = 0.047 respectively). There were no correlations between protein expression and MGL or entropy.
  
  
  CONCLUSIONS
  Videodensitometric computer analysis of ultrasound scanning images can be used to identify stable carotid plaques, which have higher total expression levels of MMP-9 and TIMP-1 than unstable plaques.
authors.affiliation: Department of Health and Scienses - Pontificia Universidade Católica do Paraná, Rua Imaculada Conceição 1155, Curitiba, Paraná, CEP: 80215901, Brazil. lizandreabaroncini@hotmail.com
authors.forename: Liz Andréa V
authors.initials: LA
authors.lastname: Baroncini
authors.forename: Antonio
authors.initials: A
authors.lastname: Filho Pazin
authors.forename: Luiz Otávio
authors.initials: LO
authors.lastname: Murta
authors.forename: Lia S
authors.initials: LS
authors.lastname: Nakao
authors.forename: Simone G
authors.initials: SG
authors.lastname: Ramos
authors.forename: Dalton B
authors.initials: DB
authors.lastname: Précoma
mesh_terms: D000368:Aged; D015153:Blotting, Western; D002339:Carotid Arteries / Q000000981:diagnostic imaging / Q000378:metabolism / Q000601:surgery; D016893:Carotid Stenosis / Q000000981:diagnostic imaging* / Q000378:metabolism* / Q000601:surgery; D003720:Densitometry / Q000379:methods*; D016894:Endarterectomy, Carotid; D005260:Female; D006801:Humans; D008297:Male; D020780:Matrix Metalloproteinase 9 / Q000378:metabolism*; D008875:Middle Aged; D012720:Severity of Illness Index; D019715:Tissue Inhibitor of Metalloproteinase-1 / Q000378:metabolism*; D014463:Ultrasonography / Q000379:methods*; D014743:Videotape Recording / Q000379:methods
chemical_list: C560822:TIMP1 protein, human; D019715:Tissue Inhibitor of Metalloproteinase-1; D020780:Matrix Metalloproteinase 9