E. Petersen

Does Lipoprotein(a) Inhibit Elastolysis in Abdominal Aortic Aneurysms

PURPOSE to test the hypothesis that there is a negative association between serum levels of lipoprotein(a) (Lp(a)) and elastin-derived peptides (EDP) as well as matrix metalloproteinase (MMP)-9 activation in the aneurysm wall in patients with asymptomatic abdominal aortic aneurysms (AAA). MATERIAL AND METHODS from 30 patients operated for asymptomatic AAAs, preoperative serum samples and AAA biopsies were collected. Lp(a) (mg/L) and EDP (ng/ml) in serum were measured by enzyme linked immunosorbent assays. MMP-9 activity (arbitrary units) in the AAA wall was measured by gelatin zymography and the ratio: active MMP-9/total MMP-9 were calculated. RESULTS there was a significant negative correlation (Spearmans rho) between serum levels of Lp(a) and EDP (r= -0.707, p<0.001), as well as the share of activated MMP-9 (r= -0.461, p=0.01) in the AAA wall. CONCLUSION this preliminary study indicate that Lp(a) inhibit elastolysis in asymptomatic AAA.

Dynamic Sonography with Provocation of Pain for Diagnosis of Symptomatic Mobile Kidneys

OBJECTIVE To evaluate the results of nephropexy in patients with a diagnosis of symptomatic mobile kidney that had been established by dynamic sonography with provocation of pain. DESIGN Prospective study. SETTING University hospital, Sweden. SUBJECTS 19 consecutive patients with symptomatic right-sided mobile kidney and 6 controls who had urographically mobile kidneys but no pain. INTERVENTIONS Dynamic sonography and dislocation of the kidney by manipulation. All 19 patients experienced pain on manipulation and the 6 controls did not. The 19 patients were treated by nephropexy and followed for at least four years postoperatively. MAIN OUTCOME MEASURE Relief of pain after nephropexy. RESULTS In 16/19 patients the pain was relieved by nephropexy. CONCLUSION Dynamic ultrasound is useful in correlating the abnormal position of the kidney with pain, and successfully indicates those patients whose symptoms will be relieved by nephropexy.

Two-dimensional high-resolution electrophoresis of elastin-derived peptides.

Degradation of human aortic elastin in vivo yields a restricted number of differentially sized and charged peptides. Elastin-derived peptides (EDP) can be analyzed by two-dimensional electrophoresis after their extraction from human abdominal aortic tissue by 0.2 M sodium chloride. The peptides were separated according to charge by acetic acid-urea-PAGE and then according to molecular mass by SDS-PAGE. The identity of these peptides as EDP was continued by immunoprecipitation and Western blots. The two-dimensional electrophoretic system can resolve desmosine-like cross-linked EDP of the similar molecular configuration but differing in the number of positively charged amino acid residues. The new separation technique of EDP has the capacity to identify defects in desmosine-like cross-links and may be useful in characterizing abberations in elastin structures.