[Percutaneous transluminal coronary angioplasty in patients with prior surgical revascularization]. / Angioplastia coronária transluminal percutânea em pacientes com revascularização cirúrgica prévia.

PURPOSE: To show the author's experience with percutaneous transluminal coronary angioplasty (PTCA) in patients with prior coronary bypass surgery. METHODS: Between January 1989 and January 1991, 629 PTCA in 572 patients were performed. Forty-eight had previous revascularization surgery with interval range of 4 days to 10 years. The PTCA sites were divided in three groups: A) native arterial segments, not affected by surgery (26 patients); B) native arterial segments proximal (4 patients) and distal (2 patients) to graft anastomosis; C) in the coronary vein graft (16 patients). RESULTS: The overall primary success was 78%. In groups B and C, 16 procedures were successfully dilated (72%). All failures in group C were due to unstable problems in reaching (4 patients) or crossing (2 patients) the stenosis with the balloon. There was one death in group A and another in group C. CONCLUSION: Angioplasty is an effective alternative for treatment of recurrent ischemia in patients with prior myocardial revascularization surgery and in early results are comparable to the general angioplasty population.

[Coronary angioplasty in patients over 70. An analysis of 115 dilatations]. / Angioplastia coronária em pacientes acima de 70 anos. Análise de 115 dilatações.

PURPOSE: To verify the validity of transluminal coronary angioplasty (PTCA) in the population over 70 years old. METHODS: Retrospectively, were analysed 115 PTCA performed in 89 elderly patients (70 to 85 years old) from January 1988 to January 1991. Three groups were defined: A) single vessel-77 (86.5%) patients; B) double vessel-9 (10.1%) patients; C) three vessel-3 (3.4%) patients. RESULTS: Of the 89 treated patients, 81.8% in group A, 72.2% in group B and 75% in group C were successfully dilated. The learning curve had showed increase in success rate after the first 250 angioplasties (from 60.6% to 82.5%). Treatment of acute myocardial infarction by direct thrombolysis was made in 7 patients (6 S, 1 I). Major complications included: deaths (4.4%), ventricular fibrillation (1.08%), acute coronary occlusion (6.6%). Emergency coronary artery bypass grafting was required in 4.4% with one death. CONCLUSION: Coronary angioplasty is an effective treatment in elderly patients and may be performed with acceptable success and with low complications.

Properties of ATPase activity associated with peroxisomes of rat and bovine liver.

1. Peroxisomes were isolated from bovine and rat liver by use of differential and density gradient centrifugations. 2. In the final density gradient (Nycodenz) a distinct peak of ATPase activity codistributed with the peroxisome marker catalase and was well separated from the bulk of the ATPase activity and from markers for other subcellular organelles. 3. The peroxisome-associated ATPase had a pH optimum of 7.5 and was inhibited by N-ethylmaleimide, by N,N'-dicyclohexylcarbodiimide and by 7-chloro-4-nitrobenzo-2-oxa-1,3-diazole, but was unaffected by up to 30 microM n-tributyltin chloride. 4. Prolonged incubation with oligomycin at high concentrations indicated that 50% of peroxisomal ATPase was resistant to this inhibitor. The oligomycin-sensitive ATPase activity required at least a four-fold higher ratio of inhibitor to protein for inhibition than mitochondrial ATPase did. It was concluded that oligomycin-sensitive and oligomycin-resistant ATPase may be associated with liver peroxisomes.

[Percutaneous transluminal coronary angioplasty. Analysis of 305 dilatations]. / Angioplastia coronária transluminal percutânea. Análise de 305 dilatações.

PURPOSE: To show the initial experience of this service with the technique of percutaneous transluminal coronary angioplasty. PATIENTS AND METHODS: Between january 1988 and december 1989, 305 coronary angioplasties were performed in 280 patients with age range of 33 to 82 years (being 49% above 60 years old) and 71% male. Among those, 212 (75%) experienced clinical picture of stable angina and 68 (25%) of unstable angina or myocardial infarction. Patients were divided in three groups: group A--those with lesions of 70% or worse in more than one vessel or in the same vessel with or without any other vessel total occlusion (multiple lesions or multiple vessels: 36 patients; group B--those with lesions of 70% or worse in one vessel with at least one occluded vessel: 64 patients; group C--those with lesions of 70% or worse isolated in a single vessel: 180 patients. RESULTS: Of the 280 treated patients, 229 were considered successful (75%). There has been 22 complications (7%) and 9 deaths (3%). The late follow-up (from 1 to 24 months), displayed 28 new procedures based on clinical suspicion of restenosis. Obstruction or occlusion were present in 16 of the later, with 10 being selected to undergo new procedure, one of those twice. The remaining 12 patients received clinical or surgical treatment. CONCLUSION: Aside from the fact that early and midterm results indeed are promising, the procedure is not safe from immediate risks, and limiting late restenosis. Nevertheless, the lesions might be redilated by the same technique, with success rates comparable to the initial one.