Permanent implants

The two commonly used methods for radiation therapy are external-beam radiotherapy and brachytherapy.26 In external-beam radiotherapy, doses of 70 to 75 Gy are delivered in 35 to 41 fractions in patient with low-grade prostate cancer and 75 to 80 Gy for those with intermediate- or high-grade prostate cancer. Brachytherapy involves the permanent implantation of radioactive beads of 145 Gy of 125I or 124 Gy of 103Pd and generally is reserved for individuals with low-risk cancers. 

By using tiny probes as neural prostheses, scientists may be able to restore nerve function in quadriplegics and make the blind see or the deaf hear. Thanks to advanced techniques, a single, small, implanted probe can stimulate individual neurons electrically or chemically and then record responses. Preliminary results suggest that the microprobe telemetry systems can be permanently implanted and replace damaged or missing nerves. 

The Safe Medical Devices Act requires reporting of medical devices that probably caused the death, serious filness, or injury of a patient. Postmarket surveillance on permanently implanted devices required with methods for tracing and locating patients depending on such devices. FDA is authorized to recall device product. 

Yang s paper implies that the ideal artificial organ should be permanently implanted in the body. It is our feeling that this restriction makes the program needlessly complicated. Our philosophy is that a program to design an intermediate... 

Hurst BS. Permanent implantation of expanded polytetrafluoroethylene is safe for pelvic surgery. United States Expanded Polytetrafluoroethylene Reproductive Surgery Study Group. Human Reproduction 1999, 14, 925-927. 

Ellozy SH, Carroccio A, Lookstein FRA, et al, First experience in human beings with a permanently implantable intrasac pressure transducer for monitoring endovascular repair of abdominal aortic aneurysms, J Vase Surg 2004 40(3) 405-412. 

Degradation-resistance. Unexpected material degradation is usually caused by hydrolysis, oxidization, enzymolysis, lipid invasion or calcification. The talent of degradation-resistance is essential for materials used in permanent implants. 

Pd103 17d Permanent implant brachytherapy for early-stage prostate cancer... 

Waga J, Ohta A, Ehinger B (1991) Intraocular microdialysis with permanently implanted probes in rabbit. Acta Ophthalmol (Copenhagen) 69 618-624. 

Permanent implants, prostheses, vascular grafts, catheters, and drug delivery devices... 

Both short- and long-term studies of the effectiveness of permanently implanted probes have been undertaken in the rabbit eye, and in one study probes remained in place for up to six months (48,49,54-58). An early rabbit study of microdialysis probes determined the optimum surgical technique to insert the probes and examined... 

Iodine-125 sources. Iodine-125 is widely used for permanent implants in radiotherapy. The encapsulation consists of a 0.05 mm thick titanium tube welded at both ends to form a cylindrical capsule of dimensions 4.5 x 0.8 mm. Iodine-125 decays exclusively by electron capture to an excited state of Technetium-125, which then emits a 35.5 keV photon. Characteristic x-rays in the range of 27 to 35 keV also are produced due to the electron capture and internal conversion processes. 

EM s chemical structure consists of a 14-membered macrocyclic lactone ring (erythronolide) connected to a deoxyamino sugar (desosamine) and a deoxy sugar (cladinose) as shown in Fig. 5. We synthesized about 250 EM derivatives and examined their GMS and antibacterial activities [19, 20]. GMS activity was tested by intravenous injection of the test compounds to fasted conscious dogs with permanently implanted force transducers in the stomach, and antibacterial activity was estimated as minimum inhibitory concentration (MIC) by agar dilution method. The EM derivatives shown in Fig. 5 exhibited higher GMS activities with less antibacterial activities compared with those of EM (Table I). 

Nursing homes, hospitals, and other facilities that utilize medical devices were required to report to the FDA information arising out of medical devices that contributed to the death or serious injury of a patient. The FDA acquired the authority to order device recalls. Manufacturers of devices were required to conduct post-market surveillance on all permanently implanted devices whose failure might cause serious harm or death. 

Total joint replacements are permanent implants, unhke those used to treat fractures, and the extensive bone and cartilage removed during implantation makes this procedure irreversible. Therefore, when faced with prosthesis failure and the impossibility to reimplant, the patient will face severe shortening of the extremity, instability or total rigidity of the joint, dif culty in ambulation, and often will be confined to a wheel chair. 

Precaution Do not use in medical applies, involving permanent implantation in human body Nucrel 0902HC [DuPont]... 

Uses For extrusion coating applies, incl. foil-containing shampoo, toothpaste, towelette, condiment, and misc. non-food pouches and sachets, snack structures other foil, metalized film, or paper coatings as heat seal or tie layer food-contact polymers Regulatory FDA 21 CFR 177.1330 compliant Properties Pellets sp.gr. 0.93 melt flow 8.0 dg/min f.p. 84 C m.p. 103 C Vicat soften, pt. 86 C 8.7% methacrylic acid Precaution Do not use in medical applies, involving permanent implantation in human body Nucrel 0910HS [DuPont]... 

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