Publications by authors named "Youn-Myoung Gimm"

Accumulating evidence does not yet confirm the effect of power line frequency magnetic field (MF) on human health and fertility. We recently reported that, at continuous 60 Hz MF exposure in mice, the dose given as magnetic flux density (tesla; T) and duration of exposure was related to induce testicular germ cell apoptosis. We aimed to characterize the effect of a 20-week continuous exposure to 60 Hz MF on the motility, morphology, and number of sperm as well as the apoptosis of testicular germ cell in rats.

View Article and Find Full Text PDF

Purpose: As a continuing study of 20 kHz triangular magnetic fields (MF) [Lee et al. 2006 ], we investigated the chronic toxicity and possible health effects of exposure to 20 kHz MF at the flux density of 30 microT, which is the limit standard for the occupational population in South Korea, with the use of Sprague-Dawley rats.

Materials And Methods: Rats were exposed to 20 kHz triangular MF at 30 microT Root Mean Square for 8 h/day for 18 months.

View Article and Find Full Text PDF

As a continuation of our previous study, we performed a teratological evaluation of the importance of gestational age with regards to the exposure of 20 kHz intermediate frequency magnetic field (IF) on pregnant ICR mice. The pregnant mice were exposed to a 20 kHz IF magnetic field for 8 h/day in a carousel irradiator at 30 microT which is the limit standard for occupational population in Korea. The animals were sacrificed on the 18th day of gestation and the fetuses were examined for mortality, growth retardation, changes in head size and other morphological abnormalities.

View Article and Find Full Text PDF

We recently reported that continuous exposure, for 8 weeks, of extremely low frequency (ELF) magnetic field (MF) of 0.1 or 0.5 mT might induce testicular germ cell apoptosis in BALB/c mice.

View Article and Find Full Text PDF

In order to evaluate possible tumorigenic effects of a 20 kHz intermediate frequency triangular magnetic field (IF), a frequency emitted from TV and PC monitors at 6.25 microT rms, which is the regulated exposure limit of magnetic field for the public in Korea, mammary tumors were produced in female Sprague-Dawley rats by oral intubation of dimethylbenz(a)anthracene (DMBA), lung tumors in ICR mice by scapular region injection of benzo(a)pyrene (BP), and skin tumors in female ICR mice by topical application of DMBA and tetradecanoylphorbol ester (TPA). IF was applied 8 h/day for 14 weeks beginning the day after DMBA treatment for mammary tumor experiment, for 6 weeks after weaning for lung tumor, and for 20 weeks beginning 1 week after DMBA application for skin tumor experiment.

View Article and Find Full Text PDF

Sprague-Dawley rats (10 each of male and female per group for sham and magnetic field exposed) were exposed in a carrousel irradiator to 20 kHz intermediate frequency (IF) magnetic field at 6.25 microT rms for 8 h/day, 5 days/week for 90 days. Urine analysis (pH, serum glucose, protein, ketone bodies, RBC, WBC, bilirubin, urobilinogen, and specific gravity), blood analysis [WBC, RBC, hemoglobin, hematocrit, mean corpuscular volume (MCV), mean corpuscular hemoglobin (MCH), mean corpuscular hemoglobin concentration (MCHC), thrombocyte count, and leucocyte count], blood biochemistry (total protein, blood urea nitrogen, creatinine, glucose, total bilirubin, total cholesterol, aspartate aminotransferase, alanine aminotransferase, alkaline phosphatase, and lactate dehydrogenase), and histopathological analysis for organs such as liver, kidney, testis, ovary, spleen, brain, heart, and lung were performed on day 90.

View Article and Find Full Text PDF

In order to evaluate the importance of gestational age in possible effects due to exposure to a 20 kHz sawtooth magnetic field, pregnant ICR mice at gestational 2.5-15.5 days post-coitus, which is the most sensitive stage for the induction of major congenital malformations, were exposed in a carrousel irradiator.

View Article and Find Full Text PDF