Noninfiltrating angiolipoma of the mediastinum.

A case of mediastinal angiolipoma in a 63-year-old man is described. A computed tomographic scan of the thorax demonstrated a large encapsulated mass with fatty and soft-tissue components near the esophagus. This appearance was considered suggestive of a liposarcoma. However, at surgery a benign noninfiltrating angiolipoma was found and removed. To the authors' knowledge, angiolipomas have not previously been reported to occur within the mediastinum.

Degradation of gonococcal peptidoglycan by granule extract from human neutrophils: demonstration of N-acetylglucosaminidase activity that utilizes peptidoglycan substrates.

The degradation of purified Neisseria gonorrhoeae peptidoglycan (PG) by granule extract derived from normal human polymorphonuclear leukocytes was examined. Hen egg lysozyme-resistant, extensively O-acetylated [3H]PG (O-PG) from strain FA19 and lysozyme-sensitive, non-O-acetylated [14C]PG (non-O-PG) from strain RD5 (each containing label in both glucosamine and muramic acid) were mixed and incubated with granule extract at pHs 4.5, 5.5, and 6.5. The rate of degradation of O-PG was uniformly slower than that of non-O-PG in the same tube, but ultimately, even the O-PG was rendered completely soluble. Molecular-sieve high-performance liquid chromatography revealed that both PGs were degraded by granule extract at the pH values tested to disaccharide peptide monomers and peptide-cross-linked oligomers, reflecting the action of human lysozyme. Of particular interest was the appearance of a peak containing free N-acetylglucosamine which was quite prominent in reaction mixtures at pH 4.5, less prominent at pH 5.5, and not detectable at pH 6.5. Free N-acetylglucosamine was not released from control PG samples at any pH in the absence of granule extract. Treatment of purified gonococcal PG monomers with granule extract at pH 4.5 yielded exclusively free N-acetylglucosamine and muramyl peptides with no N-acetylglucosamine. These data suggest that granule extract contains a previously undescribed pH-dependent N-acetylglucosaminidase with specificity for PG as well as an N-acetylmuramidase activity that degrades O-PG less efficiently than it does non-O-PG.

Treatment of anastomotic bypass graft stenosis with directional atherectomy: short-term and intermediate-term results.

PURPOSE: Areas of anastomotic stenosis in lower-extremity bypass grafts (BPGs) were treated by means of directional atherectomy (DA) in hopes of achieving better patency rates than have been reported with percutaneous transluminal angioplasty (PTA). MATERIALS AND METHODS: During a 4-year period, 17 patients (11 men and six women) with 23 areas of anastomotic stenosis in 18 lower-extremity BPGs were selected for treatment with DA. Urokinase thrombolysis was initially performed in eight BPGs that were thrombosed at the time of presentation. Adjunctive preatherectomy PTA was performed in six lesions, and postatherectomy PTA was performed in three lesions. RESULTS: The technical success rate for DA was 92% (23 of 25 sites). There was less than 50% restenosis at 74% of the areas of stenosis (14 of 19 sites), with a mean follow-up time for the sites of 13 months. The graft patency rate was 88% (14 of 16 grafts), with a mean follow-up time for the grafts of 14 months. Areas of stenosis treated with DA alone had the same patency rates as those treated with DA and PTA. CONCLUSIONS: DA is an effective treatment method for anastomotic peripheral arterial BPG stenosis. The intermediate-term patency rates following DA are superior to those reported for PTA and similar to those reported for surgical revision.