[Angioplasty of distal aorta and iliac, femoral, popliteal, renal and subclavian arteries. Early and late results]. / Angioplastia de aorta distal e artérias ilíaca, femoral, poplítea, renal e subclávia. Resultados imediatos e tardios.

PURPOSE: To study the late results of peripheral angioplasty. PATIENTS AND METHODS: In the period of 8 years from August, 1981 until August, 1989, 27 patients were submitted to 33 procedures of peripheral angioplasty. RESULTS: There was success in 29 procedures, an insufficient dilatation in 1 and and failure in 3 (2 new attempts were effective). Success rate was 88% of the procedures; clinical and angiographic success was reached in 25 (93%) of the 27 patients. Thirty four obstructions were successful dilated: 12 in renal artery, 12 in common iliac artery, 4 in external iliac artery, 3 in superficial femoral artery, 1 in distal aorta. In the evolution we had a restenosis of a renal artery that was redilated, a precocious occlusion of a common iliac artery (9% of common iliac artery dilatations and 6% of the total of the iliac dilatations) and a popliteal occlusion. Of the 34 dilatations we had a patency of 91% until 2 months. CONCLUSION: Angioplasty showed to be an effective method with good results in the long term follow-up.

Oxidation reactions by prostaglandin cyclooxygenase-hydroperoxidase.

oxidations of organic sulfides, amines, and even enzymes catalyzed by purified and microsomal forms of prostaglandin cyclooxygenase-hydroperoxidase have been studied using O2 incorporation into arachidonic acid to monitor oxygenase and [14C]15-hydroperoxyprostaglandin E2 reduction to prostaglandin E2 to measure hydroperoxidase. The oxygenase was protected by phenol against the irreversible deactivation induced by low levels of hydroperoxides. Furthermore, the EPR signal noted during reactions with the microsomal enzyme probably reflected the adventitious oxidation of endogenous materials. As described previously for phenol and other reducing cosubstrates, methyl phenyl sulfide (MPS) increased hydroperoxidase activity at all concentrations studied, while stimulating oxygenase at low levels and inhibiting it at 5-10 mM. In stoichiometric equivalence with 15-hydroperoxyprostaglandin E2 reduction, MPS was enzymatically oxidized to its analogous sulfoxide, methylphenyl sulfoxide, acquiring an oxygen atom exclusively from the hydroperoxide and demonstrating some chiral character. In contrast, other oxidizable compounds such as N,N-dimethylphenylenediamine and aminopyrine reacted via radical intermediates. Phenylbutazone, which is oxidized using dissolved molecular oxygen, did not compete with MPS oxidation. Hence, MPS was oxidized while bound to the enzyme, whereas the amine oxidation occurred in solution via an enzyme-formed oxidant. The Soret peak noted with cyclooxygenase-hydroperoxidase was examined as a possible measure of this binding, but was also noted in denatured and deactivated enzyme, suggesting that its relevance should be reconsidered. Despite the similarities in their drug-metabolizing profiles, cyclooxygenase-hydroperoxidase is clearly distinct from cytochrome P-450. The mechanism of this hydroperoxidase is considered in the context of other more extensively studied peroxidases.

Mechanism of oxygen transfer by prostaglandin hydroperoxidase.

The peroxidase associated with prostaglandin cyclooxygenase in ram seminal vesicle microsomes will utilize a wide variety of hydroperoxides and reducing substrates. One such reducing substrate, sulindac sulfide (cis-5-fluoro-2-methyl-1-[p-(methylthio)benzylidenyl]indene-3-acetic acid), inhibits the oxygenase, stimulates the peroxidase, and is oxidized to its analogous sulfoxide by the peroxidase. The peroxidase-catalyzed transfer of oxygen atoms from 15-hydroperoxyprostaglandin E2 (15-HPE2) to sulindac sulfide was examined using [18O]15-HPE2 which was prepared enzymatically and analyzed mass spectrometrically. The sulfoxide resulting from sulindac sulfide oxidation was also analyzed mass spectrometrically and found to possess an oxygen atom arising exclusively from the 15-HPE2. Since sulindac sulfide inhibits the oxygenase activity of this enzyme (ID50 approximately equal to 0.2 microM), it seemed possible that the oxygen atom was transferred while the sulfide was bound to this site. However, indomethacin, an inhibitor of the oxygenase with no effect on the peroxidase, did not alter the stoichiometry of sulindac sulfide oxidation, precluding this possibility. These findings are discussed in the context of identifying the nature of the actual oxidant and distinguishing between the oxidation mechanisms of various peroxidases and between sulindac sulfide and other reducing substrates for these enzymes.