acetylcellulose and Foreign-Bodies

Migration of particulate matter from plastic tubing and solid plastic implants has been documented in a number of studies, including some with the use of cardiac bypass, haemodialysis, and pump-assisted intravenous infusions. In order to ascertain whether silicone embolisation occurs when children have an Ivac 560 pump-assisted IV infusion, we passed 180 ml of pumped fluid through a microfilter and compared the scanning electron micrographs of those filters with unused filters and with others through which a similar volume had been passed without using the pump. The particles on the filters were analysed for their elemental content using energy-dispersive X-ray analysis. In addition, the appearance of the silicone tubing used in the pump over 3 and 72 h was assessed and compared to that of flow-only and unused tubing. More particles were found on the microfilter when fluid had been delivered via the pump than on those through which non-pumped fluid had passed or that were unused. Elemental silicon-containing particles were only found on the filter when a pump had been attached to the IV line. The flow-only and unused tubing were found to have adherent particles on the inner surface that were not seen once the tubing had been used for 3 h in the Ivac 560 pump. Also, after 72 h use, the silicone tubing had a deformed inner layer. The clinical significance of these findings is yet to be determined, but it does appear that silicone embolisation occurs during pump-assisted infusions in children.

Topics: Biocompatible Materials; Cellulose; Child; Electron Probe Microanalysis; Embolism; Filtration; Foreign Bodies; Humans; In Vitro Techniques; Infusion Pumps; Infusions, Intravenous; Membranes, Artificial; Microscopy, Electron, Scanning; Silicones; Time Factors

Tests of 12 popular brands of cigarettes manufactured by 6 companies from the United States have shown that fibers were released from the filters and that there exists probable cause to suggest that fibers are inhaled and/or ingested. Filter fibers, made of cellulose acetate, were implanted in mice for 6 months. The fibers withstood degradation and retained the tobacco-brown color and bright fluorescence of the tobacco tar that had been adsorbed from cigarette smoke. With a confocal laser scanning microscope, we have observed cigarette filter fibers in lung tissue from patients with lung cancer and who were known to be habitual smokers. These findings raise the question as to whether fibers released from cigarettes further jeopardize the health of smokers and document the need to test components of cigarette filters for toxicity and tumorigenicity.

Topics: Animals; Cellulose; Filtration; Foreign Bodies; Humans; Lung; Mice; Smoking