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Objectives: Ketamine hydrochloride (KT) is a secondary amine that has been safely used as an injectable anesthetic and analgesic to avoid the production of nitroso compounds in the stomach. However, ketamine in the tablet form has recently become an abused, recreational drug. The aim of this study was to investigate the genotoxic effects of N-nitrosoketamine (NKT) and KT on the basis of an in vitro micronucleus (MN) test using a Chinese hamster lung fibroblast cell line (CHL/IU).Methods: NKT was synthesized from KT in our laboratory. In the MN tests, CHL/IU cells were continuously treated with either NKT or KT for 24, 48, or 72 hours without the S9 mix. The cells were also treated with NKT or KT with or without the S9 mix for 6 hours, followed by a recovery period of 18, 42, or 66 hours (short-term treatment). The results were considered to be statistically significant when the p-values of both Fisher's exact test and the trend test were less than 0.05.Results: After the short-term treatment with either NKT or KT with and without the S9 mix, the frequency of micronuclei significantly increased. However, the frequency of micronuclei did not significantly increase after the continuous treatment with either NKT or KT. Both NKT and KT were determined to be genotoxic in the short-term treatment with or without the S9 mix, but they were determined to be nongenotoxic in continuous treatment.Conclusion: Our findings suggest that NKT has a stronger genotoxic effect than KT.

Objectives: Epidemiological studies have suggested that exposure to environmental and occupational electromagnetic fields (EMFs) contribute to the induction of brain tumors, leukemia, and other neoplasms. The aim of this study was to investigate the genotoxic effects of exposure to 50-Hz EMFs, and of co-exposure to cisplatin, a mutagen and carcinogen, and 50-Hz EMFs, using an in vivo newborn rat astrocyte micronucleus assay.Methods: Three day-old male Sprague-Dawley rats were co-exposed to 50-Hz EMFs and 1.25 or 2.5 mg/kg of cisplatin. Brain cells were dissociated into single cells and cultured for 96 hours, then stained with acridine orange and an antibody against glial fibrillary acidic protein. The frequency of micronucleated astrocytes was counted with a fluorescent microscope.Results: The frequency of micronuclei was not increased in rat astrocytes exposed to EMFs alone. However, the frequencies of micronuclei in co-exposure to 2.5 mg/kg cisplatin and EMFs (7.5-and 10-mT) were significantly increased, compared with those in exposure to 2.5 mg/kg cisplatin alone (shamexposure, 0-mT EMFs) for 72 hours (p<0.01).Conclusion: Exposure to EMFs alone did not have a genotoxic effect but co-exposure to EMFs increased the genotoxic activity induced by cisplatin. Our findings suggest that EMFs enhance the genotoxic effects of cisplatin.

Background: Disseminated Varicella zoster virus infection (DVI) is a severe infection associated with severe abdominal pain of unknown cause. We report a case in which periarterial (the celiac artery and superior mesenteric artery) fat stranding (PFS) on computed tomography (CT) was the presumed cause of abdominal pain in a patient taking pomalidomide. Case Presentation: A 62-year-old woman was admitted to our hospital with abdominal pain. Her medical history was multiple myeloma treated with pomalidomide. Computed tomography showed no remarkable findings on admission, but 1 day later, a contrast-enhanced CT showed PFS. A skin eruption appeared on day 4 and we started acyclovir. On day 10, Varicella zoster virus antigen and antibody tests were positive, confirming the diagnosis of DVI. The abdominal pain subsequently improved, together with the PFS, and she was discharged. Conclusion: When patients present with severe abdominal pain and PFS, DVI and acyclovir must be considered.