• Journal of Photoscience
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• 제9권3호
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• pp.37-40
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• 2002

Astronauts are constantly exposed to space radiation at a low-dose rate during long-tenn stays in space. Therefore, it is important to determine correctly the biological effects of space radiation on human health. Space radiations contain various kinds of different energy particles, especially high linear energy transfer (LET) particles. Therefore, we have to study the relative biological effectiveness (RBE) of space radiation under microgravity environment which may change RBE from a stress for cells. Furthermore, the research about space radiation might give us useful information about birth and evolution of life on the earth. We also can realize the importance of preventing the ozone layer from depletion by use of exposure equipment to sunlight at International Space Station (ISS).

• 환경생물
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• 제19권3호
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• pp.205-210
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• 2001

묵은 배추와 무 종자에 저선량 ${\gamma}$선을 조사하여 종자발아율과 발아유식물의 효소활성 변화를 조사하였다. 발아율은 대조구에 비해 저선량 조사구에서 증가하는 경향을 보였는데 특히 발아초기단계에 효과가 뚜렷하게 나타났으며 배추는 2 Gy와 8 Gy조사구에서 4-ll % 정도, 무는 2 Gy, 6 Gy, 10 Gy 조사구에서 25-41% 정도 증가하였다. 저선량 ${\gamma}$선이 조사된 배추와 무의 유묘초장도 저선량 조사구에서 증가하였는데 특히 배추의 경우는 4 Gy와 l0 Gy 조사구에서, 무는 6 Gy 조사구에서 뚜렷한 증가효과를 보였다. 저선량 조사구의 단백질 함량은 발아초기단계에 대조구에 비해 증가하였으며 POD와 CAT 활성은 4 Gy와 l0 Gy 조사구에서 증가하였다. 이에 저선량 $\gamma$선에 의해 묵은 종자의 발아와 효소활성이 촉진됨을 확인할 수 있었다.

• Journal of Radiation Protection and Research
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• 제48권2호
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• pp.59-67
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• 2023

Background: This study aims to reevaluate natural radiation exposure, following up on our previous study conducted in 2019, and to assess the associated risk of lung cancer to the public residing in the gold mining areas of Betare-Oya, east Cameroon, and its vicinity. Materials and Methods: Gamma-ray spectra collected using a 7.62 cm×7.62 cm in NaI(Tl) scintillation spectrometer during a car-borne survey, in situ measurements and laboratory measurements performed in previous studies were used to determine the outdoor absorbed dose rate in air to evaluate the annual external dose inhaled by the public. For determining internal exposure, radon gas concentrations were measured and used to estimate the inhalation dose while considering the inhalation of radon and its decay products. Results and Discussion: The mean value of the laboratory-measured outdoor gamma dose rate was 47 nGy/hr, which agrees with our previous results (44 nGy/hr) recorded through direct measurements (in situ and car-borne survey). The resulting annual external dose (0.29±0.09 mSv/yr) obtained is similar to that of the previous study (0.33±0.03 mSv/yr). The total inhalation dose resulting from radon isotopes and their decay products ranged between 1.96 and 9.63 mSv/yr with an arithmetic mean of 3.95±1.65 mSv/yr. The resulting excess lung cancer risk was estimated; it ranged from 62 to 216 excess deaths per million persons per year (MPY), 81 to 243 excess deaths per MPY, or 135 excess deaths per MPY, based on whether risk factors reported by the U.S. Environmental Protection Agency, United Nations Scientific Committee on the effects of Atomic Radiation, or International Commission on Radiological Protection were used, respectively. These values are more than double the world average values reported by the same agencies. Conclusion: There is an elevated level of risk of lung cancer from indoor radon in locations close to the Betare-Oya gold mining region in east Cameroon. Therefore, educating the public on the harmful effects of radon exposure and considering some remedial actions for protection against radon and its progenies is necessary.

• Asian Pacific Journal of Cancer Prevention
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• 제15권19호
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• pp.8171-8175
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• 2014

Background: To study the radioprotective effects of flavonoids from Rosa roxburghii Tratt (FRT). Materials and Methods: The radioprotective effects of FRT were investigated by examining cell viability, 30-day survival of mice and the number of colony-forming units in spleen (CFU-S) after total-body 60Co irradiation. Results: The survival rates of irradiated cells gradually increased with increasing concentrations of FRT. The survival rate was the highest at 87% with a concentration of $30{\mu}g/mL$. Pretreatment with FRT was needed to realize its radioprotective activity in mice at the dose of 60 mg/kg. With the increasing doses of 30 mg/kg, 60 mg/kg and 120 mg/kg, the numbers of CFU-S increased, and were significantly different compared with the control group. Conclusions: Pretreatment with FRT prior to irradiation resulted in significantly higher cell survival at 24 h after 5 Gy radiation, increased 30-day survival in mice after exposure to a potentially lethal dose of 8 Gy, and resulted in a higher number of CFU-S in mice after exposure to a dose of 6 Gy. These results collectively indicate that FRT is an effective radioprotective agent.

• Child Health Nursing Research
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• 제11권4호
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• pp.456-464
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• 2005

Purpose: To determine the effects of hand massage on nausea and vomiting, and anxiety in children with Iymphocytic leukemia receiving high dose chemotherapy. Method: The children were assigned to an experimental group(15) or a control group(15). All of the children were diagnosed with acute Iymphocytic leukemia and admitted for high dose chemotherapy at C University Medical Center in Seoul. The hand massage was performed for 10 minutes twice a day over three days. To measure the effects of hand massage, the Index of Nausea and Vomiting by Rhodes et al. and the State-Trait Anxiety Inventory for children by Spielberger were used. The level of anxiety was measured by systolic blood pressure, diastolic blood pressure, and pulse rate. Results: The score for nausea and vomiting decreased in the experimental group. State anxiety for the experimental group was significantly more positive than for the control group at the 2nd measurement. There was a significant difference in systolic blood pressure between the two groups. The level of diastolic blood pressure in the two groups decreased significantly over time. Conclusion: Hand massage could be effective in decreasing nausea and vomiting, state anxiety, pulse rate and blood pressure in children with acute leukemia receiving high dose chemotherapy.

• Biomolecules & Therapeutics
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• 제7권1호
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• pp.89-96
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• 1999

CJ-50002 is an oral vaccine against V.vulnificus infection composed of whole cell lysate of V. vulnificus. The general pharmacological properties of CJ-50002 were evaluated in various animals and in vitro system. CJ-50002 at oral doses of 0.2, 2 and 20 mg/kg had no effect on general behavior in mice, chromo- and electro-convulsions in mice, writhing syndrome induced by acetic acid in mice, body temperature in rats, charcoal meal propulsion in mice and urine and electrolytes excretion in rats. However, oral administration of CJ-50002 at dose of 20 mg/kg prolonged the hexobarbital-inuced sleeping inducing time in mice. In anesthetized dogs, CJ-50002 showed no effect on blood pressure, heart rate and ECG but decreased the respiratory rate and femoral blood flow at dose of 20 mg/kg. p.o. CJ-50002 had no effect on the contractile response of the isolated guinea pig ileum to various spasmogen at concentrations of 0.2, 2 and 20 $\mu\textrm{g}$/ml, respectively. Since these pharmacological effects of CJ-500o2 were observed at dose much greater than those in clinical use (approximately 0.16 mg/kg, p.o.), it is likely that this vaccine may be relatively free of undesirable effects in clinical practice.

• 약학회지
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• 제32권2호
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• pp.129-136
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• 1988

Effects of the selective alpha-adrenoceptor agonists, clonidine, oxymetazoline and phenylephrine, on heart rate and contractile force were investigated in the isolated frog atria and it was attempted to examine the influence of adrenoceptor antagonist upon those. Clonidine produced dose-dependent negative chronotropic and positive inotropic effects. The negative chronotropic effect was significantly attenuated in the presence of prazosin and yohimbine but not propranolol. The positive inotropic effect was significantly attenuated by prazosin, yohimbine and propranolol. Oxymetazoline produced dose-dependent negative chronotropic and inotropic effects. The negative chronotropic effect was significantly attenuated in the presence of prazosin, which was partially augmented by yohimbine but was not affected by propranolol. The negative inotropic effect was not affected by propranolol but it was partially augmented by yohimbine and was partially attenuated by prazosin. Phenylephrine produced dose-dependent positive chronotropic and inotropic effects. The positive chronotropic and inotropic effect were significantly attenuated in the presence of propranolol but were not affected by prazosin and yohimbine. These results suggest that the negative chronotropic effect by clonidine and oxymetazoline is mediated by alpha-adrenoceptors, the positive chronotropic and inotropic effects by phenylephrine are mediated by beta-adrenoceptors, and alpha-adrenoceptors mediated the inhibitory chronotropic responses exists in the isolated frog atria.

• 생명과학회지
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• 제29권12호
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• pp.1345-1350
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• 2019

한약재로 쓰이는 용담(Gentiana scabra)의 열수 추출물(GS-W)을 정상 마우스에 경구 투여할 경우 in vivo 위장관이송률(ITR)이 유의적이고 용량 의존적으로 증가한다는 사실이, 최근 본 연구진에 의해 보고된 바 있다. 이에 본 연구에서는, in vivo 실험적 위장관 운동 기능 저해(GMD) 마우스 모델에서는 GS-W가 ITR에 어떠한 영향을 미치는지 검정하고자 하였다. GS-W는 5 g/kg의 고용량 경구 투여 시에도 정상 마우스에서 급성 독성을 나타내지 않았고, GMD 마우스에서 ITR을 유의적이고 용량 의존적으로 증가시켰으며, 특히 1 g/kg 경구 투여 시의 ITR은 cisapride 투여 시보다 수치 상으로 높았다. 이러한 결과들은, 1990년대까지 임상적으로 널리 처방되었으나 치명적인 부작용으로 인해 2000년 이후 시장에서 철수된 약물인 cisapride를 GS-W가 대체하여, 인간의 다양한 GMD 상황을 예방하거나 그 증상을 완화시킬 수 있는 잠재력이 있음을 시사한다.

• Toxicological Research
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• 제19권2호
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• pp.123-131
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• 2003

This study was carried out to assess the combined repeated dose, reproduction and developmental toxicities of benzoyl peroxide for OECD SIDS (Screening Information Data Set) program. Male and female Sprague-Dawley rats were exposed to benzoyl peroxide at dose levels of 0, 250, 500 and 1,000 mg/kg/day for 29 days for males and for 41-51 days for females. No deaths were found in all animals including control group during exposure period. No hematological effects attributable to benzoyl peroxide were observed in all treated groups. Significant decrease in the weight of testes and epididymis were observed in males at 1,000 mg/kg/day. In females at 1,000 mg/kg/day, slight histopathological effects in uterus such as epithelial vacuolation or hyperplasia were observed. No treatment-related changes in precoital time and rate of copulation, fertility and gestation period were noted in all treated groups. There was no evidence of teratogenic effect of benzoyl peroxide, but body weight of pups at 1,000 mg/kg/day was significantly decreased. NOAEL for combined repeated dose and reproduction/developmental toxicity was 500 mg/kg/day.

• Clinical and Experimental Reproductive Medicine
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• 제39권4호
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• pp.144-152
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• 2012

Objective: Concerns are growing about the decrease in male reproductive health. Caffeine is one of the popular nutrients that has been implicated as a risk factor for infertility. In the present study, we examined whether in utero and lactational exposure to caffeine affects the reproductive function of the offspring of rats. Methods: Pregnant rats received caffeine via drinking water during gestation (26 and 45 mg/kg) and lactation (25 and 35 mg/kg). Body and reproductive organ weight, seminiferous tubule diameter, germinal epithelium height, sperm parameters, fertility rate, number of implantations, and testosterone level of the offspring were assessed from birth to adulthood. Results: Significant dose-related decreases were observed in the body and reproductive organ weight, seminiferous tubule diameter, and germinal epithelium height of the offspring. Sperm density had declined significantly in offspring of the low-dose and high-dose groups, by 8.81% and 19.97%, respectively, by postnatal day 150. The number of viable fetuses had decreased significantly in females mated with male offspring of the high-dose group at postnatal days 60, 90, 120, and 150. There were also significant reductions in testosterone levels of high-dose group offspring from birth to postnatal day 150. Conclusion: It is concluded that maternal caffeine consumption impairs gonadal development and has long-term adverse effects on the reproductive efficiency of male offspring rats.