sub:provenance {
  beldoc: dce:description "Approximately 61,000 statements." ;
    dce:rights "Copyright (c) 2011-2012, Selventa. All rights reserved." ;
    dce:title "BEL Framework Large Corpus Document" ;
    pav:authoredBy sub:_6 ;
    pav:version "1.4" .
  sub:_5 prov:value "A previous study by our laboratory (9) showed that emphysematous lungs express MMP-1 whereas normal adult lungs do not. To determine whether this MMP-1 expression correlated with elevated mitogen-activated protein kinase, we analyzed these same human samples for p-ERK activity. Initial experiments were performed in the absence of the specific p42/p44 (ERK) substrate to determine endogenous protein phosphorylation in normal and emphysematous lungs. No difference was detected (Fig. 5A, left). However, when specific p-ERK activity was examined, significantly higher levels were detected in lung homogenates from patients with emphysema, compared with healthy control subjects (Fig. 5A, right: 1.9 ± 0.2-fold increase above normal lung, p = 0.02). We next assessed levels of ERK in eight human lung samples. Western blot analysis revealed that emphysematous lungs expressed higher p-ERK levels than normal lungs (Fig. 5B)." ;
    prov:wasQuotedFrom pubmed:14764579 .
  sub:_6 rdfs:label "Selventa" .
  sub:assertion prov:hadPrimarySource pubmed:14764579 ;
    prov:wasDerivedFrom beldoc: , sub:_5 .
}