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Purpose: To evaluate the necessity of metallic stenting of the sphincter of Oddi in malignant obstructive jaundice when the tumor is more than 2 cm from the papilla of Vater.Methods: Sixty-seven self-expandable biliary stents were used in 60 patients with extrahepatic lesions of the common hepatic or common bile duct and with the distal margin of the tumor located more than 2 cm from the papilla of Vater. Stents were placed above the papilla in 30 cases (group A) and in another 30 with their distal part protruding into the duodenum (group B).Results: The 30-day mortality was 15%, due to the underlying disease. The stent occlusion rate was 17% after a mean period of 4.3 months. No major complications were noted. Average survival was 132 days for group A and 140 days for group B. In group A, 19 patients survived < or = 90 days and in eight of these, cholangitis occurred at least once. Of 11 patients in group A with survival > 90 days, only two developed cholangitis. In group B, 13 patients who survived < or = 90 days had no episodes of cholangitis and in 17 with survival > 90 days, cholangitis occurred in three. There is a statistically significant difference (p < 0.05) regarding the incidence of cholangitis in favor of group A.Conclusions: In patients with extrahepatic lesions more than 2 cm from the papilla and with a relative poor prognosis (< or = 3 months), due to more advanced disease or to a worse general condition, the sphincter of Oddi should also be stented in order to reduce the postprocedural morbidity. [ABSTRACT FROM AUTHOR]

The Excimer laser can be used to remove biological debris from underlying substrates. The ability of the krypton fluoride (KrF) Excimer laser to remove Aspergillus niger mold, which had been grown on filter paper, was evaluated in the present study. The air in the immediate vicinity of the laser cleaning apparatus was sampled to determine if viable mold fragments were released into the air during treatment. It was found that filter paper could be sterilized with the Excimer laser wavelength with the proper selection of parameters. During this process, viable spores and mold fragments are released into the atmosphere, and pose a relative risk unless proper measures to prevent contamination of the work area are taken. [ABSTRACT FROM AUTHOR]

Pulsed ultraviolet laser ablation of two polyurethane films has been studied in terms of ablation rate behaviour and time-of-flight mass spectroscopy of the positively charged photofragments. Three excimer laser wavelengths (193, 248 and 308 nm; 17-30 ns pulse duration) and short-pulse laser system (pulse duration 500 fs or 5 ps, at 248 nm) were employed. The results of the influence of energy fluence on the ablation rate are tested against other photoablation models and a table of fitted physical constants is presented. The upper limit of the mean activation energy for desorption is found to be considerably lower than the energy required to break single covalent bonds. The mass analysis of the positively charged species produced during the photoablation process provides valuable insight into the photofragmentation mechanism. [ABSTRACT FROM AUTHOR]