• Progress in Medical Physics
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• v.19 no.3
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• pp.157-163
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• 2008

Retinal prosthesis is regarded as the most feasible method for the blind caused by retinal diseases such as retinitis pigmentosa or age-related macular degeneration. One of the prerequisites for the success of retinal prosthesis is the optimization of the electrical stimuli applied through the prosthesis. Since electrical characteristics of degenerate retina are expected to differ from those of normal retina, we investigated differences of the retinal waveforms in normal and degenerate retina to provide a guideline for the optimization of electrical stimulation for the upcoming prosthesis. After isolation of retina, retinal patch was attached with the ganglion cell side facing the surface of microelectrode arrays (MEA). $8{\times}8$ grid layout MEA (electrode diameter: $30{\mu}m$, electrode spacing: $200{\mu}m$, and impedance: 50 $k{\Omega}$ at 1 kHz) was used to record in-vitro retinal ganglion cell activity. In normal mice (C57BL/6J strain) of postnatal day 28, only short duration (<2 ms) retinal spikes were recorded. In rd/rd mice (C3H/HeJ strain), besides normal spikes, waveform with longer duration (~100 ms), the slow wave component was recorded. We attempted to understand the mechanism of this slow wave component in degenerate retina using various synaptic blockers. We suggest that stronger glutamatergic input from bipolar cell to the ganglion cell in rd/rd mouse than normal mouse contributes the most to this slow wave component. Out of many degenerative changes, we favor elimination of the inhibitory horizontal input to bipolar cells as a main contributor for a relatively stronger input from bipolar cell to ganglion cell in rd/rd mouse.

• Progress in Medical Physics
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• v.18 no.1
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• pp.20-26
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• 2007

It is expected that synaptic construction and electrical characteristics In degenerate retina might be different from those In normal retina. Therefore, we analyzed the retinal waveform recorded with multielectrode array in normal and degenerate retina using principal component analysis (PCA) and Independent component analysis (ICA) and compared the results. PCA Is a well established method for retinal waveform while ICA has not tried for retinal waveform analysis. We programmed ICA toolbox for spatiotemporal analysis of retinal waveform. In normal mouse, the MEA spatial map shows a single hot spot perfectly matched with PCA-derived ON or OFF ganglion cell response. However In rd/rd mouse, the MEA spatial map shows numerous hot and cold spots whose underlying interactions and mechanisms need further Investigation for better understanding.

• Progress in Medical Physics
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• v.21 no.2
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• pp.209-217
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• 2010

Retinal prostheses are being developed to restore vision for the blind with retinal diseases such as retinitis pigmentosa (RP) or age-related macular degeneration (AMD). Since retinal prostheses depend upon electrical stimulation to control neural activity, optimal stimulation parameters for successful encoding of visual information are one of the most important requirements to enable visual perception. Therefore, in this paper, we focused on retinal ganglion cell (RGC) responses to different voltage stimulation parameters and compared threshold charge densities in normal and rd1 mice. For this purpose, we used in vitro preparation for the retina of normal and rd1 mice on micro-electrode arrays. When the neural network of rd1 mouse retinas is stimulated with voltage-controlled pulses, RGCs in degenerated retina also respond to voltage amplitude or voltage duration modulation as well in wild-type RGCs. But the temporal pattern of RGCs response is very different; in wild-type RGCs, single peak within 100 ms appears while in RGCs in degenerated retina multiple peaks (~4 peaks) with ~10 Hz rhythm within 400 ms appear. The thresholds for electrical activation of RGCs are overall more elevated in rd1 mouse retinas compared to wild-type mouse retinas: The thresholds for activation of RGCs in rd1 mouse retinas were on average two times higher ($70.50{\sim}99.87\;{\mu}C/cm^2$ vs. $37.23{\sim}61.65\;{\mu}C/cm^2$) in the experiment of voltage amplitude modulation and five times higher ($120.5{\sim}170.6\;{\mu}C/cm^2$ vs. $22.69{\sim}37.57\;{\mu}C/cm^2$) in the experiment of voltage duration modulation than those in wild-type mouse retinas. This is compatible with the findings from human studies that the currents required for evoking visual percepts in RP patients is much higher than those needed in healthy individuals. These results will be used as a guideline for optimal stimulation parameters for upcoming Korean-type retinal prosthesis.

• Journal of the East Asian Society of Dietary Life
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• v.23 no.1
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• pp.31-38
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• 2013

This study was designed to evaluate the effect of a rice-based diet on body weight and serum lipid levels. Thirty male C57BL/6 mice were randomly divided into three groups and fed a high-fat diet (HFD), rice-based diet (RD), or bread-based diet (BD) for five weeks. Our results showed that the RD group had a significantly lower final body weight, although there was no significant difference in daily food intake among the groups. There was a reduction in body weight gains, adipose tissues weight, and adipocyte size of epididymal adipose tissue in the RD group (p<0.05). Also, serum triglycerides and total cholesterol in the RD group were significantly decreased compared to the BD group. RD also reduced fasting glucose and insulin levels. These results indicate that the intake of RD attenuates increases in body weight and serum lipid concentrations in mice, suggesting its benefits for the dietary control of obesity and hyperlipidemia.

• Korean Journal of Pharmacognosy
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• v.51 no.4
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• pp.340-348
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• 2020

This study was conducted to evaluate the immunomodulatory effects of red doraji (Platycodon grandiflorum, RD) prepared by repeated steaming and drying process in the immune-suppressed mice induced by pre (RD-A) or post-treatment (RD-B) with cyclophosphamide. The immune-stimulating effects of ethanol RD extract in in vivo at 150 (RD-1) and 300 mg/kg body weight (RD-2) for RD-A and RD-B groups were measured and compared to the NC group supplied with distilled water only or positive control group. After 14 days of oral supplement, serum IgA, IgG, and cytokine levels, splenocytes proliferation rate, NK cell activity, and gene expression of cytokines were measured as immune related biomarkers. Serum IgA, IgG, IL-1β, and IL-12 levels increased in both RD-A and RD-B groups while serum TNF-α level decreased in RD-A group compared to the NC group. Splenocytes proliferation rate, NK cell activity, and cytokine (IL-1β, IL-6, IFN-γ) expression levels were also improved by RD supplement in the both groups. The RD showed more significant immunomodulatory effects at higher dose (RD-2) rather than the lower dose (RD-1). Thus, RD has an immune efficacy in a dose dependent manner and can be used as an immune stimulating source to improve immunity.

• Parasites, Hosts and Diseases
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• v.26 no.2
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• pp.117-120
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• 1988

The egg laying capacity of Fibritola seoulensis was observed in mice and rats. In mice, the mean number of eggs produced by an adult worm a day was 116 at the 1st week after infection, 123 at the 2nd week and 42 at the 3rd week. Thereafter, the capacity of about 20 eggs/worm/day was maintained up to one year period. In rats, it generally produced more eggs; 49 at 1 week, 250 at 2 weeks, 216 at 4 weeks, 327 at 6 months and 11 at one year after infection. It survived longer than a year in mice and rats.

• Korean Journal of Veterinary Research
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• v.44 no.2
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• pp.179-184
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• 2004

The purpose of the study was to investigate the effect of ginseng saponins (panaxadiol, ginsenoside $Rb_1$, $Rb_2$, Rc, Rd) on jejunal crypt survival, endogenous spleen colony formation and apoptosis in jejunal crypt cells of mice irradiated with gamma-ray. ICR mice were given each saponin (i.p. 50 mg/kg of body weight) at 24 hours before irradiation. The radioprotective effects of saponins were compared with the irradiation control respectively. The jejunal crypts were protected by pretreatment with ginsenoside Rc (p<0.05) and Rd (p<0.05). The spleen colony was increased by pretreatment with panaxadiol (p<0.05) and ginsenoside Rd (p<0.05). And the frequency of radiation induced apoptosis was significantly reduced by pretreatment with panaxadiol (p<0.05), ginsenoside Rb2 (p<0.05), Rc (p<0.05) and Rd (p<0.01). These results suggest that ginsenoside Rc, Rd might have a major radioprotective effect.

• Radiation Oncology Journal
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• v.16 no.2
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• pp.107-114
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• 1998

Purpose : Ginkgo biloba extract(GBE) is known to increase the peripheral blood circulation. This study was designed to evaluate the effect of GBE on the acute normal tissue radiation reaction. Materials and Methods : mice were divided into two groups, radiation alone and two doses GBE plus radiation, for both acute skin reaction and jejunal crypt assay. GBE was given i.p. one hour before irradiation with priming dose given one day earlier. Thirty to Fifty Gy for acute skin reaction and 11 to 14 Gy for jejunal crypt were irradiated to right hind leg and whole body, respectively. Results : Radiation doses($RD_{50}$) for Peak skin score of 2.0 were 44.2Gy (40.6-48.2Gy) for radiation alone and 44.4Gy(41.6-47.4Gy) for two doses GBE plus radiation, showing no effect of GBE on acute radiation skin damage. The numbers of regenerating jejunal crypts per circumference were also almost the same for each radiation dose level(p=0.57-0.94), and the mean lethal doses($D_o$) were 1.800y(1.57-2.09Gy) for radiation alone and 1.88Gy(1.65-2.18Gy) for two doses GBE plus radiation, indicating no effect of GBE on jejunal crypt cell survival after radiation. Conclusion : GBE doesn't increase acute normal tissue radiation reaction in this model system. As GBE was verified to enhance radiation effect on tumor, high therapeutic gain is expected when GBE is combined with radiation therapy.

• Korean Journal of Plant Resources
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• v.34 no.5
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• pp.433-442
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• 2021

The fermented red ginseng by microorganism is known to increase pharmacological activity in vivo. To evaluate the bioavailablity of red ginseng fermented by probiotics, we conducted the pharmacokinetic study of ginsenoside Rb1, Rd and total ginsenosides (TG, ginsenosides Rb1 + Rd + Rg1 + F2 + Rg3 + compound K) in BALB/C mice. The AUC value of ginsenoside Rb1 in mice serum administered with 600mg/kg drugs showed 21.93 ± 14.68 ng·h/mL (RGw, water extract), 275.211 ± 110.04 ng·h/mL (RGe, 50% ethanol extract) and 404.91 ± 162.57 ng·h/mL (fRGe, fermented red ginseng extract). Analysis of ginsenoside Rd also showed a higher ACU value in fRGe than in RGw or RGe. And the AUC value of total ginsenosides in mice serum treated with 600 mg/kg were observed 42.12 ± 23.44 ng·h/mL (RGw), 321.44 ± 133.5 ng·h/mL (RGe) and 537.33 ± 229.01 ng·h/mL (fRGe), respectively. C_max value of ginsenoside Rb1 in mice administered with 600mg/kg were observed 3.67 ± 3.34 ng/mL (RGw), 23.27 ± 8.81 ng/mL (RGe) and 25.52 ± 7.29 ng/mL (fRGe). These results can be considered that the fermented red ginseng has more bioavailability than that of unfermented red ginseng. In quantitative analysis of the inflammation-related cytokines IL-1β and TNF, no significant difference was found between the fermented red ginseng (fRGe) and the red ginseng (RGe).

• Journal of Veterinary Clinics
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• v.18 no.1
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• pp.14-17
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• 2001

Recombinant interleukin-2 (IL-2) has demonstrated as an antineoplastic agent in mice and human, but the relatively low response rates observed in clinical trials. Therefore, the present study was undertaken in order to evaluate therapeutic activities of IL-2 for the establishment of therapeutic applications. At the onset of the experiment, normal C3H/HeN mice were injected with $3{\times}10^6$ RD-995 tumor cells, murine ultraviolet radiation-induced fibrosarcoma, subcutaneously. Beginning on day 25, experimental groups were treated with a 5-day course of IL-2 (subcutaneous injection of 30,000 IU every 12 hours for 5 days). The result of this experiment revealed that RD-995 tumor grew progressively in control mice. Subcutaneous IL-2 therapy decreased tumor growth until day 23, then the tumor grew progressively. No significant difference in the survival of IL-2 therapy decreased tumor growth until day 23, then the tumor grew progressively. No significant difference in the survival of IL-2 therapy decreased tumor growth until day 23, then the tumor grew progressively. No significant difference in the survival of IL-2 treated mice were observed compared with the control mice.