[Availability evaluation of closed systems by using practical training kits for preparation of antitumor drugs].

The recent guidelines of the Japanese Society of Hospital Pharmacists on the antitumor drug preparation have recommended the use of closed systems such as the PhaSeal® system for preventing cytotoxicity in health care workers involved in the preparation of these drugs. The PhaSeal® system and Clave® Oncology system were evaluated using a practical training kit for the preparation of antitumor drugs. The two systems were compared in terms of handling time, satisfaction as to availability, leakage of drugs from the connections in the system and area of drug spillage because improvements in convenience or lower cost system were available. With the closed systems, the average handling time increased by 10∼20%. The area of drug spillage did not significantly decrease. Leakage of drugs from the system was detected for all samples prepared with the Clave® Oncology system, and for some samples prepared with the PhaSeal® system. In terms of availability, the PhaSeal® system was better than the Clave® Oncology system. In conclusion, to decrease the exposure of health care workers to antitumor drugs during their preparation in a closed system, it is important to evaluate the handling time, operability, robustness with regard to drug leakage and spillage, and proficiency in handling of the closed system.

Budding yeast mms4 is epistatic with rad52 and the function of Mms4 can be replaced by a bacterial Holliday junction resolvase.

MMS4 of Saccharomyces cerevisiae was originally identified as the gene responsible for one of the collection of methyl methanesulfonate (MMS)-sensitive mutants, mms4. Recently it was identified as a synthetic lethal gene with an SGS1 mutation. Epistatic analyses revealed that MMS4 is involved in a pathway leading to homologous recombination requiring Rad52 or in the recombination itself, in which SGS1 is also involved. MMS sensitivity of mms4 but not sgs1, was suppressed by introducing a bacterial Holliday junction (HJ) resolvase, RusA. The frequencies of spontaneously occurring unequal sister chromatid recombination (SCR) and loss of marker in the rDNA in haploid mms4 cells and interchromosomal recombination between heteroalleles in diploid mms4 cells were essentially the same as those of wild-type cells. Although UV- and MMS-induced interchromosomal recombination was defective in sgs1 diploid cells, hyper-induction of interchromosomal recombination was observed in diploid mms4 cells, indicating that the function of Mms4 is dispensable for this type of recombination.