Selective radiofrequency heating of ferrosilicone occluded tissue: a preliminary report.
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Biomedical subjects
Publications and source records attributed to R W Rand.
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After administration of high systemic doses of heparin verified by assay, common carotid arteries in the rat were divided and sutured. Scanning electron microscope observations of endothelial surfaces showed a decrease in platelet adhesion, as well as a reduction in the adherence of other circulatory blood elements when compared to controls. This is the first report indicating the in vivo effect of high dose systemic heparin on platelets.
Sixty common carotid arteries in rats were divided and anastomosed with four needles that differed in suture to needle diameter ratios. Scanning electron microscopic observations of the suture revealed endothelial bridges with associated fibrin, platelets and leukocytes arising from needle holes to adhere to the sutures within two hours of anastomosis. These earliest reported observations of suture endothelialization merit further investigation regarding the possibility of an arterial thrombosis occurring after suture.
Candida osteomyelitis of the spine and intervertebral disc developed in three patients without evidence of back trauma of overlying cutaneous infection. Two patients were prone to the development of disseminated candidiasis by the use of multiple antibiotics and other predisposing modalities following abdominal surgery. One patient had no identifiable cause for development of the infection. The diagnosis was established in all three cases by x-ray evidence of osteomyelitis and culture from needle aspirate. Two patients had bone scans consistent with infection. Each patient received different therapy. One was treated with amphotericin B, one with spinal fusion and 5-fluorocytosine, and one with no antifungal therapy. All patients had complete healing of the involved vertebrae. Candida organisms have the potential to cause destructive bone infection following hematogenous dissemination. The presence of Candida osteomyelitis may be helpful in diagnosing disseminated candidiasis.
Arterial vascular occlusion of hypernephromas may be performed by obstructiing the tumor vascular tree with the injection of ferromagnetic silicone microspheres. The powerful superconducting electromagnet confines the embolized iron-silicone compound to the neoplastic target organ. Radioactive material may or may not be added to the iron-silicone compound to give local direct radioactive radiation therapy to the tumor area. In experimental dogs up to 70,000 rad of beta radiation from the P32 source had been delivered homogeneously within the kidney when mixed with the ferrosilicone. This technique may well be used in cases in which a major operation is contraindicated or when preoperative necrosis of the tumor is advisable. Since the entire procedure can be done with the patient under local anesthesia in a radiology department it may be a valuable new technique in the future management of urological tumors, unilateral renal hypertension, solitary kidney pathology and so forth. Ferrosilicone material has not been found to be toxic. The application of a powerful superconducting electromagnet to the technique provides a means of confining the embolized iron-silicone compound to the target organ.
An increasing number of parkinsonian patients in whom levodopa fails to relieve tremor are being referred for thalamotomy. The literature suggests that in as many as 50 percent of patients treated with levodopa, there is no relief of tremor because of refractoriness to the medication or intractable side effects which limit dosage. Thalamotomy abolishes contralateral tremor in 90 percent of patients, with an associated mortality rate of 1 to 2 percent and morbidity of 6 percent. The relative merits and complications of levodopa and thalamotomy were reviewed and a therapeutic regimen designed in which the two approaches to treatment are combined to most effectively deal with all the symptoms of parkinsonism.
Changes in the endothelial surface of the common carotid artery of the Sprague-Dawley rat were observed by scanning electron microscopy after vessels were removed prior to sacrifice or after gluteraldehyde cardiac perfusion. Rates were classified according to whether the vessels was 1) untouched prior to removal, 2) dissected and observed for a period of time, and 3) clamped and observed. Changes consisted of small 1-6 micron craters as well as smooth or cross-striated endothelial ridges or folds. Clamped arteries appeared to exhibit more frequent craters. In contrast, vessels removed prior to death and briefly washed with saline exhibited craters different morphologically from those vessels perfused with gluteraldehyde. Background endothelial folds also differed from the gluteraldehyde-perfused group, exhibiting a cobblestoned or breaded appearance with distorted endothelial bridges. This supports the suggestion of Nelson that premortem perfusion of heart and ascending aorta with gluteraldehyde is necessary to reduce artifact in arterial endothelial structures.
Scanning electron microscopic findings in 26 rats with sutured 1 to 1.2 mm segments of carotid artery indicate a difference in morphological changes beneath clamped areas and areas 2 to 3 mm adjacent to the suture line. Craters similar to those observed in control specimens were seen beneath clamped sites without significant platelet aggregation or platelet adherence to the endothelial wall. In contrast, areas adjacent to the suture line exhibited a pattern of fibrin and platelet adherence to the vessel endothelial wall. These changes appeared to be consistent after one to four hours of observation in most animals. Sutures, although attracting some platelets, did not exhibit platelet and fibrin adherence as marked as that of the adjacent endothelial wall.
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The `limited' pneumoencephalogram has been used with excellent success at UCLA for the continuing follow-up of pituitary tumours. It is most useful in following nonsecretory adenomas since tumour regrowth can occur in the absence of clinical signs and symptoms. Total serial pneumoencephalography has not been accepted previously for follow-up of pituitary tumours since there is a significant morbidity. The `limited' pneumoencephalogram of the diseased area drastically reduces the morbidity of the procedure so that the patients are willing to undergo serial studies on an outpatient basis.
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