PRO JECT

Papers of the Month - SEP 00

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    1. Wilmink AB, Quick CR, Hubbard CS, Day NE.  The
    association between connective tissue laxity and the
    risk of AAA.  Eur J Vasc Endovasc Surg  2000; 20:
    290-5.
    
    Abstract (abridged from authors):  190 cases and 231
    controls.  A connective tissue laxity score was
    calculated with a combination of the Bieghton joint
    mobility score and the presence of pes planus,
    scoliosis, pectus deformities, flexible auricular
    cartilages, and Gorlin's sign.  Odds ratios were 3.1
    for the highest group ofconnective tissue scores, and
    2.4 for the middle group.  Serum TypeIII Procollagen by
    radio-immunoassay was the same in cases and controls. 
    "Aneurysms may be associated with abnormal connective
    tissue rather than an increased breakdown of normal
    collagen."
    
    comment by mdt:  That's what I thought too for many
    years, but I could never prove it.  We began to make
    more progress when we turned away from the notion that
    a mutation was affecting the structural collagen, to
    the idea of matrix instability. 
    
    2. Crowther M, et al.  Increased matrix MMP-2
    expression in vascular smooth muscle cells cultured
    from AAA.  J Vasc Surg  2000; 32: 575-83.  
    
    Abstract: Aortic SMCs and dermal fibroblasts were
    cultured from AAA patients and age-matched controls
    with atherosclerosis.  All cells constitutively
    produced MMP-2 (AAA significantly greater than
    control SMC's).  MMP-2 mRNA was also higher in AAA than
    control. Dermal fibroblasts were similar to control
    fibroblasts.  Levels for MMP's 1, 3, and 9 were the
    same in AAA and controls.  The authors conclude that
    regulation of MMP-2 gene expression is altered in
    aortic SMC's.
    
    comment by mdt:  Something seems unusual here.  
    Combining information from tables III and IV, the
    median concentrations of MMP-2 in ng/mL, from
    conditioned serum-free medium are:
    
    Control SMC  ----  262.3
    AAA SMC----------  758.2
    Control fibroblast 779.6
    AAA fibroblast---- 662.5
    
    I would not have predicted that dermal fibroblasts,
    from either AAA or control patients, would be producing
    almost three times as much enzyme as AAA SMC's.