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PubMed1994

Computer-assisted surgical techniques using the Vanderbilt Free Electron Laser.

The Vanderbilt Free Electron Laser (FEL) is capable of lasing between 2.0 and 8.0 microns with a high peak intensity pulsed structure. The FEL is used to investigate potential applications in otolaryngology. Charring of temporal bones and thermal stress patterns in Plexiglas indicate thermal buildup at 20 and 10 Hz repetition rates of the laser. Also, transient temperature changes measured with thermocouples in a gelatin model reveal that significant heat production occurs at these laser repetition rates. To utilize the fastest laser repetition rates and maintain minimal lateral thermal damage, a computer-controlled scanning system was devised. The authors have also used the computer control with the carbon dioxide laser and experienced improved ablation.

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Development of atherosclerosis in genetically hyperlipidemic rabbits during chronic fish-oil ingestion.

The evidence for a reduction in cardiovascular mortality from fish oil is based on epidemiologic observations. To test whether fish-oil supplementation influences the development of atherosclerosis, we treated Watanabe heritable hyperlipidemic rabbits (WHHL), an inbred strain that spontaneously develops atherosclerosis, with 2.5 ml of MaxEPA fish-oil concentrate daily and compared them to a control group fed unsupplemented rabbit chow. Serial cholesterol and triglyceride levels were monitored as were plasma lipid hydroperoxides. The animals were given fish oil from the time of weaning until 1 year of age, when they were sacrificed and their aortas were compared for the extent of atherosclerosis. No significant differences in the cholesterol or triglyceride levels were noted between the two groups. Fatty acid hydroperoxide levels were also similar and were noted to increase from weaning (1.0 +/- 0.7 microM) to the time of sacrifice (1.8 +/- 1.5 microM, p less than 0.01). Fish oil had no influence on the extent of aortic atherosclerosis (25% +/- 14% surface area for controls vs. 28% +/- 19% for treated, p = NS), plaque thickness, or plaque volume after 1 year. We conclude that fish oil does not reduce the levels of serum cholesterol, lipid hydroperoxides, or aortic atherosclerosis in WHHL rabbits. The hypothesis that fish oil protects against atherosclerosis was not supported by this study.

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