From November 1981 to early March 1982, an outbreak of scleritis and/or iritis occurred among patients treated with a Nipro brand NAC series cellulose acetate capillary dialyzer. The rate of incidence with dialyzers produced in 1982 was significantly higher than that with dialyzers produced in 1981. An extract obtained from the dialyzers caused iritis in rabbits after its infusion into an auricula vein. Glycerol, acetylated carbohydrate (AC) derivatives, urethane derivatives, and polypropyleneglycol were found in the extract. AC derivatives caused iritis in rabbits, whereas they caused hyperemia of the bulbar conjunctiva in dogs. The AC derivatives contained xylose and glucose units in a ratio of 1.6-2.3:1. The amounts of AC derivatives were significantly larger in the extracts from 1982 than from 1981 devices. Moreover, another brand, but the same type, of dialyzer, the Cordis Dow 4000, contained a slight amount of them. These facts show that AC derivatives derived from hemicellulose played a primary role in the outbreak.
Recently , anxieties about toxicity of residual ethylene oxide ( EO ) in medical devices have been increasing . In respQnse to this , FDA submitted a proposal to regulate EO residual limit in 1978 . Investigations on the various conditions for gas liquid chromatographical determination of EO ill plastics or fibers were performed a 正 ong with the regulation . As a result , we recommend to use the following method , 25 % { 1exol 8 N 8 coated on chrQ 皿 osorb WAW is used for column packing for the sake of better resolution . Residual EO is tQ be extracted by ethanol at 50°to 70°C fer 3 hours , us ま ng propylene oxide for internal standard , and 100 − 1000 μ l of th6 gasous phase is to be inlected to the column . In this head space method , detection limit of EO was O. 05 ygJml , The arnount of residual EO varied according to the sampling site . An obvious difference between polyvinyl chloride tube and silicone tube in absorption and dissipation was obtained . In case of polyvinyl chloride tube , it took more than 7 days to decrease residua !EO to 25 ppm , whereas
Methods by gas chromatographic determination for ethylene oxide ( EO ) , ethylene ch1Qrohydrin ( ECH ) and ethylene glycol ( EG ) in aquous solution were investigated , and the convertions from EO to ECH a エ 1d EG in various conditions were examined . The results are as follows ; EO was not easily converted to ECH or EG in aquous state at 4GDCfor 5 hours , resulting in only a few percent of EO convertion to ECH or EG . When saline solution was circulated into b1ood tubing of an artificial kidney adsorbed l50 μglg of EO , which was made by polyvinyl chloride resin , maximum concentration of extr4cted EO ( 40 μg ! ml ) in saline solution was obtained after 6 hours . The ratio of . extracted amount of EO against the total amount of in the tubing was about 60% in this case . . In case that the amount of residual EO was relatively small such as 40 μg ! g, extracted EO was 3. 4 μ g ! m ' and extraction ratio was remarkably reduced to 20 % , When horse serum was circulated into the tubing in the san } e . . 珥 anner as the above , the investigatien resuit suggests that a part of extracted EO is combined with protein in the serum . da 国 立 衛 生 試 験 所
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