Biomedical subjects
Publications and source records attributed to J R Oyarzun.
An 80-year-old man presented with a descending thoracic aortic aneurysm. Computed tomography and aortography revealed a large aneurysm and tight aortic coarctation. This was successfully repaired with an interposition prosthesis.
The technique of using 3.5-mm acetabular reconstruction plates for multiple rib fractures with cerclage wires has been successful. We modified it by securing the reconstruction plates to the fractured ribs with cortical screws using the standard AO-ASIF (Arbeitsgemeindschaft fur Osteosynthesefragen [Association for the Study of Internal Fixation]) group technique. Our method for the internal fixation of the unstable chest wall is described. It is relatively simple and provides uniform results.
There is a need for a rapid and efficacious method of diagnosis of pulmonary infiltrates in perinatal HIV infection. However, controversy still exists about which method--open lung biopsy (OLB) versus bronchoscopic techniques--is the best for this population. We present our results with OLB in 24 children with HIV-related lung disease. Over a 6-year period, 27 OLBs were performed on 24 children with diagnosis of HIV infection. The procedures were performed under general anesthesia using a limited anterolateral thoracotomy. Suspicious areas were removed with the autostapler. The specimens were studied for the presence of non-infectious as well as bacterial, viral, fungal, and mycobacterial diseases. There were no operative deaths related to the procedure. Morbidity was limited to prolonged but self-resolving air leaks in two patients (8.3%). Five hospital deaths occurred between 3 and 12 weeks postoperatively and 11 late deaths between 3 months and 6.5 years. All deaths were related to AIDS. Eight patients (33.3%) are still alive 2 to 8 years postoperatively. A total of 43 pathologies were found in 27 specimens. A positive pathologic finding was obtained in all patients, with two patients having nonspecific minimal changes. This resulted in a change of therapy in all but one case. The technique of OLB in children with AIDS is safe and simple. It should be performed early in the course of the disease and, a careful selection of candidates can minimize the incidence of complications.
During a routine coronary revascularization procedure in a 51-year-old man, venous return was suddenly interrupted. The venous cannula was rapidly removed, revealing the pulmonary artery catheter wrapped around it. The catheter also had entered the lumen of the cannula, and the inflated balloon completely obstructed the venous return. The prompt removal and reinsertion of the venous cannula resulted in uneventful recovery of the patient.
BACKGROUND: Calcific degeneration is the most frequent cause of clinical dysfunction of glutaraldehyde (GA)-pretreated bioprosthetic heart valves. The No-React (NR) process has been shown to be a promising anticalcification treatment. In this comparative study, our objective was to delineate the advantages of the NR treatment over GA. METHODS: Bovine pericardial strips pretreated with GA and NR were individually incubated in calcium phosphate solution for 21 days at 37 degrees C. The pretreated bovine pericardium then was implanted subcutaneously in rats and retrieved at 14, 21, and 35 days after-implantation. Mineral and morphologic analyses were performed on each specimen. RESULTS: The NR-treated pericardium revealed significantly reduced in vitro calcification compared with the GA-treated tissue (mean tissue calcium content 1.3 +/- 0.2 versus 5.9 +/- 0.7 micrograms/mg; p < 0.001). Mineral analysis showed progressive calcification of the GA-pretreated pericardium over the period of implantation (calcium content increasing from 49.6 +/- 9.6 micrograms/mg after 2 weeks to 134.3 +/- 9.1 micrograms/mg at 5 weeks after-implantation). The NR-treated implants had calcified significantly less (p < 0.05) at each corresponding interval. Moreover, morphologic examinations demonstrated a protracted inflammatory response in the form of giant cell and mononuclear cell infiltration associated with intrinsic collagen disruption in the GA-treated tissue; the NR-treated pericardium maintained morphologic integrity with a mild inflammatory response. CONCLUSIONS: The NR biochemical process appears not only to attenuate pericardial calcification, but also to abort the host's destructive inflammatory response to the xenograft.
BACKGROUND: Glutaraldehyde pretreatment of bioprosthetic heart valves is the major pathogenic factor in their calcific degeneration. This comparative study investigates the merit of the No-React aldehyde detoxification process as an alternative modifier of xenograft tissues. METHODS: Glutaraldehyde- and No-React-pretreated porcine aortic valve cusps were implanted subcutaneously in 6-week-old rats (n = 20). At 3, 6, and 14 weeks, randomly selected animals were sacrificed and the explants underwent mineral and morphologic analyses. Glutaraldehyde- and No-React-treated bovine pericardium and porcine aortic valve cusp were incubated in fibroblast cell culture plates. Cell viability was observed under reversed microscope at 6, 24, 48, and 96 hours. Erythrosin B dye exclusion test was used to validate percent cell death. RESULTS: Pretreatment with No-React significantly inhibited calcification of aortic cusp subcutaneous implants throughout the 14-week period (mean tissue Ca2+ content = 1.3 +/- 0.7 micrograms/mg at 14 weeks.) Glutaraldehyde-treated cusps underwent protracted calcification (Ca2+ content = 190.6 +/- 89.5 micrograms/mg; p < 0.01). Morphologic findings correlated with mineral analyses. One-hundred percent of fibroblast cells survived in the presence of No-React-treated tissue, with a growth pattern indistinguishable from control cell culture (ie, in the presence of no tissue). The cells incubated with glutaraldehyde-treated tissue showed signs of nonviability by 6 hours, with 100% cell death by 48 hours. Dye exclusion tests validated these findings. CONCLUSIONS: The No-React detoxification process completely abolishes the cytotoxicity of the xenograft tissue and inhibits calcific degeneration.