title: Heterogeneous distribution of macrophages, tumour necrosis factor alpha, tissue factor and fibrinolytic regulators in atherosclerotic vessels.
abstract: OBJECTIVE
  To assess the representativity of small vascular samples with regard to the expression of six important factors in atherosclerotic vessels.
  
  
  METHODS
  Circumferential frozen sections of iliac and femoral arteries (n = 9) from patients undergoing reconstructive bypass surgery.
  
  
  METHODS
  Immunohistochemistry with antibodies against macrophages (CD68), tumour necrosis factor alpha, tissue factor, tissue plasminogen activator, urokinase plasminogen activator and plasminogen activator inhibitor type 1. The distribution of these antigens was characterised by computer assisted image analysis. Antigen positive area in randomly chosen samples of varying size was compared with antigen positive area in the whole vessel transections.
  
  
  RESULTS
  Marked heterogeneity was found with respect to the expression of these factors in atherosclerotic vessels. The representativity of samples was highly dependent on the size of the samples. PAI-1 was more evenly expressed compared to the other antigens.
  
  
  CONCLUSIONS
  Estimates of the expression of these factors based on small samples from atherosclerotic arteries are unreliable.
authors.affiliation: Department of Vascular Surgery, Sahlgrenska University Hospital, Gothenburg, Sweden.
authors.forename: M
authors.initials: M
authors.lastname: Falkenberg
authors.forename: T
authors.initials: T
authors.lastname: Björnheden
authors.forename: A
authors.initials: A
authors.lastname: Odén
authors.forename: B
authors.initials: B
authors.lastname: Risberg
mesh_terms: D015703:Antigens, CD / Q000032:analysis; D015214:Antigens, Differentiation, Myelomonocytic / Q000032:analysis; D001161:Arteriosclerosis / Q000378:metabolism* / Q000473:pathology; D005263:Femoral Artery / Q000378:metabolism* / Q000473:pathology; D005343:Fibrinolytic Agents / Q000378:metabolism*; D006801:Humans; D007083:Iliac Artery / Q000378:metabolism* / Q000473:pathology; D007150:Immunohistochemistry; D008264:Macrophages / Q000473:pathology; D017395:Plasminogen Activator Inhibitor 1 / Q000378:metabolism*; D010960:Plasminogen Activators / Q000378:metabolism*; D013925:Thromboplastin / Q000378:metabolism*; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism*; D000097382:CD68 Molecule
chemical_list: D015703:Antigens, CD; D015214:Antigens, Differentiation, Myelomonocytic; D005343:Fibrinolytic Agents; D017395:Plasminogen Activator Inhibitor 1; D010960:Plasminogen Activators; D013925:Thromboplastin; D014409:Tumor Necrosis Factor-alpha; C067980:CD68 antigen, human; D000097382:CD68 Molecule