title: Prevention of pleural adhesions by bioactive polypeptides - a pilot study.
abstract: OBJECTIVE
  Postoperative pleural adhesions lead to major problems in repeated thoracic surgery. To date, no antiadhesive product has been proven clinically effective. Previous studies of differently charged polypeptides, poly-L-lysine (PL) and poly-L-glutamate (PG) have shown promising results reducing postoperative abdominal adhesions in experimental settings. This pilot study examined the possible pleural adhesion prevention by using the PL+PG concept after pleural surgery and its possible effect on key parameters; plasmin activator inhibitor-1 (PAI-1) and tissue growth factor beta 1 (TGFb) in the fibrinolytic process.
  
  
  METHODS
  A total of 22 male rats were used in the study, one control group (n=10) and one experimental group (n=12). All animals underwent primary pleural surgery, the controls receiving saline in the pleural cavity and the experimental group the PL+PG solution administered by spray. The animals were evaluated on day 7. Macroscopic appearance of adhesions was evaluated by a scoring system. Histology slides of the adhesions and pleural biopsies for evaluation of PAI-1 and TGFb1 were taken on day 7.
  
  
  RESULTS
  A significant reduction of adhesions in the PL+PG group (p<0.05) was noted at day 7 both regarding the length and severity of adhesions. There were no significant differences in the concentration of PAI-1 and TGFb1 when comparing the two groups.
  
  
  CONCLUSIONS
  PL+PG may be used to prevent pleural adhesions. The process of fibrinolysis, and fibrosis was though not affected after PLPG administration.
authors.affiliation: Department of Surgery, Clinical Sciences Lund University, Lund, Sweden.
authors.forename: D
authors.initials: D
authors.lastname: Åkerberg
authors.forename: M
authors.initials: M
authors.lastname: Posaric-Bauden
authors.forename: K
authors.initials: K
authors.lastname: Isaksson
authors.forename: R
authors.initials: R
authors.lastname: Andersson
authors.forename: B
authors.initials: B
authors.lastname: Tingstedt
mesh_terms: D000818:Animals; D001706:Biopsy; D002448:Cell Adhesion / Q000187:drug effects*; D006801:Humans; D008297:Male; D017395:Plasminogen Activator Inhibitor 1 / Q000378:metabolism; D010994:Pleura / Q000187:drug effects / Q000473:pathology; D011099:Polyglutamic Acid / Q000008:administration & dosage*; D011107:Polylysine / Q000008:administration & dosage*; D011183:Postoperative Complications / Q000188:drug therapy* / Q000473:pathology; D051381:Rats; D019616:Thoracic Surgical Procedures / Q000009:adverse effects; D053773:Transforming Growth Factor beta1 / Q000378:metabolism
chemical_list: D017395:Plasminogen Activator Inhibitor 1; C508962:Tgfb1 protein, rat; D053773:Transforming Growth Factor beta1; D011107:Polylysine; D011099:Polyglutamic Acid
keywords: PAI-1; TGFb1.; pleural adhesions; polyglutamate; polylysine; postoperative