• Title/Summary/Keyword: Dose-rate effects

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Short-term protein intake increases fractional synthesis rate of muscle protein in the elderly: meta-analysis

  • Gweon, Hyun-Soo;Sung, Hee-Ja;Lee, Dae-Hee
    • Nutrition Research and Practice
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    • v.4 no.5
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    • pp.375-382
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    • 2010
  • The precise effects of protein intake on fractional synthesis rate (FSR) of muscle protein are still under debate. The sample size of these studies was small and the conclusions in young and elderly subjects were inconsistent. To assess the effect of dietary protein intake on the FSR level, we conducted a meta-analysis of controlled protein intake trials. Random-effects models were used to calculate the weighted mean differences (WMDs). Ten studies were included and effects of short-term protein intake were evaluated. In an overall pooled estimate, protein intake significantly increased the FSR (20 trials, 368 participants; WMD: 0.025%/h; 95%CI: 0.019-0.031; P < 0.0001). Meta-regression analysis suggested that the protein dose was positively related to the effect size (regression coefficient = 0.108%/h; 95%CI: 0.035, 0.182; P = 0.009). A subgroup analysis indicated that protein intake significantly increased FSR when the protein dose was ${\leq}$ 0.80 g/kg BW (16 trials, 308 participants; WMD: 0.027%/h; 95%CI: 0.019-0.031; P < 0.0001), but did not affect FSR when the protein dose was > 0.80 g/kg BW (4 trials, 60 participants; WMD: 0.016%/h; 95%CI: 0.004-0.029; P = 0.98). In conclusion, this study is the first integrated results showing that a short-term protein intake is effective at improving the FSR of muscle protein in the healthy elderly as well as young subjects. This beneficial effect seems to be dose-dependent when the dose levels of protein range from 0.08 to 0.80 g/kg BW.

DIFFERENTIAL EXPRESSION OF RADIATION RESPONSE GENES IN SPLEEN, LUNG, AND LIVER OF RATS FOLLOWING ACUTE OR CHRONIC RADIATION EXPOSURE

  • Jin, Hee;Jin, Yeung Bae;Lee, Ju-Woon;Kim, Jae-Kyung;Lee, Yun-Sil
    • Journal of Radiation Protection and Research
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    • v.40 no.1
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    • pp.25-35
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    • 2015
  • We analyzed the differential effects of histopathology, apoptosis and expression of radiation response genes after chronic low dose rate (LDR) and acute high dose rate (HDR) radiation exposure in spleen, lung and liver of rats. Female 6-week-old Sprague-Dawley rats were used. For chronic low-dose whole body irradiation, rats were maintained for 14 days in a $^{60}Co$ gamma ray irradiated room and received a cumulative dose of 2 Gy or 5 Gy. Rats in the acute whole body exposure group were exposed to an equal dose of radiation delivered as a single pulse ($^{137}Cs$-gamma). At 24 hours after exposure, spleen, lung and liver tissues were extracted for histopathologic examination, western blotting and RT-PCR analysis. 1. The spleen showed the most dramatic differential response to acute and chronic exposure, with the induction of substantial tissue damage by HDR but not by LDR radiation. Effects of LDR radiation on the lung were only apparent at the higher dose (5 Gy), but not at lower dose (2 Gy). In the liver, HDR and LDR exposure induced a similar damage response at both doses. RT-PCR analysis identified cyclin G1 as a LDR-responsive gene in the spleen of rats exposed to 2 Gy and 5 Gy gamma radiation and in the lung of animals irradiated with 5 Gy. 2. The effects of LDR radiation differed among lung, liver, and spleen tissues. The spleen showed the greatest differential effect between HDR and LDR. The response to LDR radiation may involve expression of cyclin G1.

A Cellular Physiological Study on the Effects of Korean Ginseng -Part II Effects of Saponin and Histamine on the Division of Saccharomyces- (인삼의 효과에 관한 세포생리학적 연구 -제 II 편 Saccharomyces의 분열에 미치는 Saponin과 Histamine의 영향-)

  • Jung, Noh-Pal
    • The Korean Journal of Physiology
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    • v.3 no.1
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    • pp.51-54
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    • 1969
  • The effects of saponin and histamine solution on the division of Saccharomyces cerevisiae were compared with the effects of ginseng on the division. 1. $10^{-2},\;10^{-3}%$ saponines were inhibitory on the division but $10^{-5}%$ saponin increased slightly the division, however its increasing rate was much less than that of ginseng. 2. 0.5% histamine was inhibitory on the division but $10^{-2}%$ histamine increased the division, however its increasing rate was higher than that of saponin and lower than that of ginseng. 3. Although some doses of saponin and histamine were inhibitory on the division, the increasing dose of saponin or histamine on the division could be recognized as shown in the case of the optimal dose of ginseng.

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Measurement of the Spatial Dose Rates from Radioactive Patients during Nuclear Medicine Studies (핵의학 검사에서 환자로부터의 공간선량률 측정)

  • Park, Myeong-Hwan;Lee, Jon-Il
    • Journal of radiological science and technology
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    • v.25 no.1
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    • pp.73-76
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    • 2002
  • In order to evaluate the exposure to the radiologic technologists from patients who had been administrated with radiopharmaceuticals, we measured the spatial dose rates at 5 cm, 50 cm, and 100 cm from skin surface of patients using an proportional digital surveymeter, both 5 min after injection and right before the studies. In results, the exposure to the technologists in each procedure was small, compared nth the dose limits of the medical workers. However, the dose-response relationships in cancer and hereditary effects, referred to as the stochastic effects, have been assumed linear and no threshold models ; therefore, the exposure should be minimized. For this purpose, the measurements of spatial dose rate distributions were thought to be useful.

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Effects of Low Dose Gamma Irradiation on the Inflammatory Response in Spleen Cells (저선량 감마선 노출에 의한 비장세포의 염증 유발 작용에 대한 연구)

  • Sohn, Eun-Hwa
    • KSBB Journal
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    • v.28 no.6
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    • pp.415-422
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    • 2013
  • Gamma irradiation (${\gamma}IR$) is widely used for radiotherapy as a treatment of cancer cells although it has a risk to damage normal cells. Inflammation is regarded as one of side effects of ${\gamma}IR$ while the effect of low dose of ${\gamma}IR$ on inflammation has not been researched well. Here, we investigated the inflammatory responses of low dose of ${\gamma}IR$ on murine spleen cells. It was evaluated if ${\gamma}IR$ affected the mitogen-induced lymphocyte proliferation, the regulation of various inflammatory cytokines (IFN-${\gamma}$, IL-2, IL-17, IL-4, IL-10), and the involvement of Ikaros and MAPK/NF-${\kappa}B$ medicated mechanism. Exposure of $^{137}Cs-{\gamma}IR$ below 2 Gy decreased the lymphocytes proliferative response to mitogens (LPS, ConA) except at the lowest dose, 0.05 Gy. IL-17, IL-2 and IL-4 mRNA increased at 0.5 and 2 Gy, but not altered at 0.05 Gy. IL-10, anti-inflammatory cytokine, increased only at 0.05 Gy. In regard to intracellular signaling, p-JNK, p-p38 and p-$I{\kappa}B{\alpha}$ were not changed, whereas the activation of ERK and Ikaros increased at the lowest dose. These results suggest that exposure of ${\gamma}IR$ less than 0.5 Gy (or below 0.05 Gy) has beneficial effects as a radiation hormesis on immune function.

Comparison of the anesthetic effects of 2,2,2-tribromoethanol on ICR mice derived from three different sources

  • Lee, Mi Ree;Suh, Hye Rin;Kim, Myeong Whan;Cho, Joon Young;Song, Hyun Keun;Jung, Young Suk;Hwang, Dae Youn;Kim, Kil Soo
    • Laboraroty Animal Research
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    • v.34 no.4
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    • pp.270-278
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    • 2018
  • This study was conducted to compare the anesthetic effects of 2,2,2-tribromoethanol (TBE, $Avertin^{(R)}$) in ICR mice obtained from three different sources. TBE (2.5%) was intraperitoneally injected at three doses: high-dose group (500 mg/kg), intermediate-dose group (250 mg/kg), and low-dose group (125 mg/kg). Anesthesia time, recovery time, end-tidal peak $CO_2$ ($ETCO_2$), mean arterial blood pressure, heart rate, oxygen saturation ($SpO_2$), body temperature, pH, $PCO_2$, and $PO_2$ of the arterial blood were measured. Stable anesthesia was induced by all doses of TBE and the anesthesia time was maintained exhibited dose dependency. No significant differences in anesthetic duration were found among the three different strains. However, the anesthesia time was longer in female than in male mice, and the duration of anesthesia was significantly longer in female than in male mice in the high-dose group. The recovery time was significantly longer for female than male mice in the intermediate- and high-dose groups. In the ICR strains tested, there were no significant differences in the mean arterial blood pressure, $SPO_2$, arterial blood $PCO_2$, and $PO_2$, which decreased after TBE anesthesia, or in heart rate and $ETCO_2$, which increased after TBE anesthesia. In addition, body temperature, blood biochemical markers, and histopathological changes of the liver, kidney, and lung were not significantly changed by TBE anesthesia. These results suggested that ICR mice from different sources exhibited similar overall responses to a single exposure to TBE anesthesia. In conclusion, TBE is a useful drug that can induce similar anesthetic effects in three different strains of ICR mice.

Stimulation Effect of Early Growth in Crops by Low Dose Radiation (저선량 방사선에 의한 작물 초기생육 촉진효과)

  • Kim, Jae-Sung;Song, Hi-Sup;Kim, Jin-Kyu;Lee, Young-Keun;Lee, Young-Bok
    • Korean Journal of Environmental Agriculture
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    • v.17 no.2
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    • pp.156-159
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    • 1998
  • Germination rate and early growth in crop such as rice,soybean,and perilla were observed after irradiation of $^{\gamma}$-ray (Co-60) in order to determine the effects of low does radiation. The low dose radiation was able to improve the early growth in crops and their agricultural charaters. Germination rate of 2Gy-irradiatied rice seeds was high and also were seeding height and fresh weight of the 0.5 Gy-irradiated. Germination rate and early growth of soybean were high in 4Gy-irradiated group. Perilla gew ot so promisingly after after low dose irradiation,however there slightly increasing effects on germination rate, seeding height and fresh weightat 2Gt-, 1Gy-, and 1Gy irradiated group, respectively.

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Studies on Polyacrylonitrile (3) Irradiation of Polyacrylonitrile (폴리아크릴로니트릴에 關한 硏究 (第 3 報) 폴리아크릴로니트릴에 對한 放射線照射에 關하여)

  • ICK SAM NOH
    • Journal of the Korean Chemical Society
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    • v.11 no.2
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    • pp.77-80
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    • 1967
  • Radiolysis of polyacrylonitrile(PAN) has been studied. Parameters for crosslinking and scission induced by gamma-ray irradiation were obtained by means of sol-gel partitioning method. G-value of crosslinking in PAN ($\bar{M}n=6{\times}10^5$) was 0.038 and the gel dose 21.6 Mrad. The effects of irradiation on the thermal degradation rate in PAN was also studied. No appreciable changes in thermal degradation rate observed up to 81.8 Mrad of irradiation dose.

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Survival Rate and Biological Effect of Chronic Medium-Dose-Rate Gamma Radiation Exposed to Mice (장기 중선량률 감마선 피폭에 의한 마우스의 생존율 및 생물학적 영향 평가)

  • Kim, Jae-Kyung;Jin, Yeung Bae;Oh, Su-Mi;Lee, Yun-Jong;Sung, Nak-Yun;Song, Beom-Seok;Park, Jong-Heum;Byun, Eui-Baek;Lee, Ju-Woon;Kim, Jae-Hun
    • Journal of Radiation Industry
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    • v.7 no.2_3
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    • pp.155-159
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    • 2013
  • Late effects of chronic exposure to gamma radiation are potential hazards to worker in radiation facilities as well as to the general public. Recently, chronic gamma radiation exposure effects have become a serious concern. Using a total of 60 mice, we studied the biological effects of medium-dose chronic exposure to gamma radiation. Sixty female 6-week-old specific pathogen free Balb/c mice were randomly divided into six groups (five groups irradiated and one non-irradiated control group). Irradiation was carried out for 7 days using gamma rays at dose rates of 119.65, 238.10, 357.14, 476.19 and $595.24mGy\;h^{-1}$ with total doses 20, 40, 60, 80 and 100 Gy. After irradiation, we determined survival rate of gamma radiation exposed mice during 1 week and 476.19 and $595.24mGy\;h^{-1}$ exposed group mice showed less 10% of survival rate. Otherwise, 119.65, 238.10 and $357.14mGy\;h^{-1}$ exposed group mice were survived each 100%, 80% and 70%. Half of survived mice after 1 week are immediately sacrifice and counted body and spleen weights. Compared with control non-irradiated group, total body weights and spleen weights isolated from 119.65, 238.10 and 357.14 irradiated group mice showed significant decreased. However, no significant alteration was observed between 119.65, 238.10 and $357.14mGy\;h^{-1}$ irradiated group. Overall, our results show for the first time that medium-dose chronic gamma radiation has the potential to stimulation of biological effects.

Effects of Sperm Number and Semen Type on Sow Reproductive Performance in Subtropical Area

  • Kuo, Y.H.;Hnang, S.Y.;Lee, K.H.
    • Asian-Australasian Journal of Animal Sciences
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    • v.13 no.1
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    • pp.6-9
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    • 2000
  • The purpose of this study was to evaluate the effect of lower numbers of sperm $(3{\times}10^9)$ per dose liquid semen and type of semen used in artificial insemination (AI) on sow reproductive performance in subtropical area. Semen was supplied by two commercial AI centers. A total of 671 female pigs from seven farms were inseminated with either $3{\times}10^9$ or $5{\times}10^9$ sperm per dose. Two types of semen were used: heterospermic semen from two boars of the same breed and homospermic semen from a single boar. After insemination, conception rate, farrowing rate, total litter size, and number of dead piglets were recorded. The analysis of variance indicated that there was no significant effect of interactions between pig farm, type of semen, or number of sperm on any of the traits measured. There were significant differences in conception rate, farrowing rate, and total litter size among pig farms (p<0.05). The effect of number of sperm per dose liquid semen ($3{\times}10^9$ or $5{\times}10^9$) was not significant. Sows inseminated with homospermic semen showed significantly higher conception and farrowing rates but significantly lower total litter size (p<0.05). In conclusion, the number of sperm per dose liquid semen for AI could be lowered to $3{\times}10^9 $ without affecting reproductive performance in subtropical areas like Taiwan.