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Biomedical subjects

R G Martin

Publications and source records attributed to R G Martin.

185 records · Page 11Linked to original sources
PubMedDate not supplied

An animal model of occlusion-hyperthermia of the liver.

An animal model of partial hepatic artery occlusion and radiofrequency (RF)-induced hepatic hyperthermia was developed in the New Zealand white rabbit. Seventy-seven percent (10/13) of animals survived partial hepatic artery occlusion, 82% (41/50) survived RF-induced hepatic hyperthermia, and 66% (24/36) survived combined occlusion-hyperthermia. Mesenteric infarction secondary to inadvertent embolization of intestinal arteries was the principal cause of death in animals undergoing partial hepatic artery occlusion. Extrahepatic thermal toxicity appeared to be the major cause of death in animals subjected to hepatic hyperthermia or occlusion hyperthermia although some animals showed evidence of hepatic necrosis as well. Recent developments in our laboratory hold the promise that extrahepatic thermal toxicity can be eliminated by selectively focusing heat into the liver allowing exploration of the efficacy of occlusion-hyperthermia in controlling VX-2 tumors implanted in the rabbit liver.

Animals↗
PubMedDate not supplied

Posterior chamber phakic intraocular lens for hyperopia.

PURPOSE: A Phase I U.S. FDA clinical study of a plate haptic posterior chamber phakic intraocular lens (STAAR Surgical Implantable Contact Lens) for treatment of hyperopia was conducted at 4 sites in the United States. The purpose of this report is to assess the short-term safety and efficacy. METHODS: Ten patients with hyperopia between +2.50 and +10.875 D were implanted in one eye each with the posterior chamber plate phakic intraocular lens and were examined at baseline and 1 day, 1 week, 1, 3, and 6 months after surgery. Mean baseline hyperopia was +6.63 D. RESULTS: At 6 months postoperatively, 7 of 10 eyes (70%) had an uncorrected visual acuity of 20/20 or better and 10 of 10 (100%) had 20/40 or better. Eight of ten eyes (80%) had a spectacle-corrected visual acuity within 1 line of baseline; the other two eyes (20%) had an improvement of 3 lines. Mean 6-month postoperative spherical equivalent refraction was +0.20 +/- 0.61D (range, -0.50 to +1.50 D), a reduction of 6.025 D from baseline. Eight of 10 eyes (80%) were within +/-0.50 D of emmetropia, 9 eyes (90%) were within +/-1.00 D, and all eyes (100%) were within +/-1.50 D. No operative or postoperative complications or adverse reactions were observed. CONCLUSIONS: Results support the short-term safety, efficacy, and predictability of the STAAR Surgical Implantable Contact Lens (plate haptic posterior chamber phakic intraocular lens) in the treatment of hyperopia.

Adult↗
PubMedDate not supplied

Further observations on tissue heating patterns using an invasive ground probe with radiofrequency hyperthermia system.

Critical modifications have been made in the grounded elements of a previously reported hybrid radiofrequency heating system with inductive, capacitive, and grounded elements designed for deep focal heating. These modifications facilitate introduction of the ground probe, the single invasive element of the system, into animals and humans. The modified grounded elements also enable monitoring and optimization of ground point current, thereby improving control of heating rate, and greatly increase the volume of tissue that can be heated using a single invasive grounding element, embedded in a lossy dielectric field in the near field of the radiofrequency hyperthermia system.

Hyperthermia, Induced↗