• Archives of Pharmacal Research
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• 제18권6호
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• pp.410-414
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• 1995

Adaptive response induced by low dese .gamma.-ray irradiation in human cervical carcinoma cells was examined. Cells were exposured to low dose of .gamma.-ray irradiation in human cervical carcinoma cells was examined. Cells were exposured to low dose of .gamma.-ray (1-cGy) followed by high doses of r-ray irradiation (0,1,2,3,5,7 and 9Gy for chlnogenic assay or 1.5Gy for micronucleus assay) with various time intervals. Survival fractions of cells in both low dose-irradiated and unirrated groups were analyzed by clonogenic assay. Surviva fractions of low dose-irradiated in cell survival was maximum when low and high dose irradiation time interval was 4 hr. Frequencies of micronuclei which is an indicative of chromosome aberration were also enutained from survival fractions analyzed by clonogenic assay, maximum when low and high dose irradiation time interval was 4hr. Frequencies of micronuclei which is an indicative of chromosome aberration were also enumerated in both low dose-irradiated and unirradiated groups. In consiststent with the result obtained from survival fractions analyzed by clonogenic assay, maximum reduction in frquencies of micronuclei was observed when low dose radiation was given 4 hr prior to high response to subsequent high dose .gamma.-ray irradiation in human cervical carcinomal cells. Our data suggest that one of the possible mechanisms of adaptive response induced by low dose rediation is the increase in repair of DNA double strand breaks in low dose radiation-adapted cells.

• 대한방사성의약품학회지
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• 제7권1호
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• pp.50-55
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• 2021

Low-dose radiotherapy has been known to have anti-inflammatory activity and been used for treatment of pneumonia together with anti-serum and sulfanilamide. However, it rapidly discontinued after the development of various antibiotics showing outstanding effect. Recently, it was re-considered to treat COVID-19 which has very limited treatment such as remdesivir and dexamethasone. So, several studies of COVID-19 therapy using low-dose radiation were reported very recently. They showed that low-dose radiation of 0.5~1.5 Gy were useful for decreasing the oxygen consumption and hospitalization period of COVID-19 patients without adverse reaction. Radiopharmaceuticals such as [⁹⁹mTc]Tc-macroaggregated albumin (MAA) also might be used for low-dose radiotherapy. Administration of vitamin D having anti-inflammatory effect would also be helpful for therapy with synergistic effect.

• 대한예방한의학회지
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• 제20권1호
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• pp.145-159
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• 2016

Objectives : The aim was to investigate the characteristics of low dose effect and non monotonic dose responses(NMDRs) and to predict the influence it might have on the health and medicine, traditional Korean medicine. Methods : By investigating recently published major literatures related to low dose effect and NMDRs, the definition, mechanism, major related fields, and the influence on public health and medicine has been categorized and summarized. Results : Although there are still heated debates about the definition of low dose, it implies the biological responses in environmental exposure level and the NDMDRs means the nonlinear relationship between the dose-response in the slope sign change. Also, it implies the new form of the curve showing a U, reverse U shape, and the slop sign constantly changing showing various forms. This mechanism is because the two acceptor shows opposing effects to toxic materials and the affinity is different along with the numerical value that increase and decrease being different. These characteristics generally appear in endocrine disrupters such as bisphenol A, agricultural pesticides, metal, and radiation. The research field in the public health and medical treatment is obesity, problems in metabolism, growth hormone treatment, climacteric treatment, breast cancer, intake of Korean traditional medicine for pregnancy, menopause and phytoestrogen. Conclusions : As a result of discussing implications, NMDRs is a particular effect in low dose and heated debates surround this response, research is being conducted surrounding the field of obesity, problems in metabolism, growth hormone treatment, climacteric treatment, breast cancer, intake of Korean traditional medicine for pregnancy, menopause, and phytoestrogen. More research and interest in needed as it can have a massive influence in the public health and medicine.

• Journal of Korean Neurosurgical Society
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• 제54권6호
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• pp.461-466
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• 2013

Objective : Although curcumin has a protective effect on bone remodeling, appropriate therapeutic concentrations of curcumin are not well known as therapeutic drugs for osteoporosis. The purpose of this study was to compare the bone sparing effect of treatment of low-dose and high-dose curcumin after ovariectomy in rats. Methods : Forty female Sprague-Dawley rats underwent either a sham operation (the sham group) or bilateral ovariectomy (OVX). The ovariectomized animals were randomly distributed among three groups; untreated OVX group, low-dose (10 mg/kg) curcumin administered group, and high-dose (50 mg/kg) curcumin group. At 4 and 8 weeks after surgery, serum biochemical markers of bone turnover were analyzed. Bone histomorphometric parameters of the 4th lumbar vertebrae were determined by micro-computed tomography (CT). In addition, mechanical strength was determined by a three-point bending test. Results : High-dose curcumin group showed significantly lower osteocalcin, alkaline phosphatase, and the telopeptide fragment of type I collagen C-terminus concentration at 4 and 8 weeks compared with the untreated OVX group as well as low-dose curcumin group. In the analyses of micro-CT scans of 4th lumbar vertebrae, the high-dose curcumin treated group showed a significant increase in bone mineral densities (p=0.028) and cortical bone mineral densities (p=0.036) compared with the low-dose curcumin treated group. Only high-dose curcumin treated group had a significant increase of mechanical strength compared with the untreated OVX group (p=0.015). Conclusion : The present study results demonstrat that a high-dose curcumin has therapeutic advantages over a low-dose curcumin of an antiresorptive effect on bone remodeling and improving bone mechanical strength.

• 대한의생명과학회지
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• 제25권1호
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• pp.83-91
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• 2019

This study was undertaken to investigate the therapeutic effect of Angelica acutiloba on allergic dermatitis, which Angelica acutiloba is traditionally known to have antiinflammatory effects. Sprague-Dawley (SD) rats were divided into five groups: normal control group, experimental allergic dermatitis group (vehicle group), low dose of Angelica acutiloba extract (low-dose group), high dose of Angelica acutiloba extract (high-dose group), and antihistamine treated group with experimental dermatitis (antihistamine group). Total leukocyte, neutrophil, lymphocyte, monocyte and eosinophil counts were significantly higher in the vehicle group than in the control group, but these variables were significantly lower in the low- and high-dose groups than in the vehicle group. The platelet/lymphocyte ratio in the red blood cell index was significantly lower in the low- and high-dose groups than in the vehicle group. Low and high doses of the Angelica acutiloba extract did not have toxic effects on liver and kidney. Serum NO, iNOS and levels were highest in the vehicle group but significantly lower in the low- and high-dose groups, especially in the high-dose group. The results of this study suggested that the Angelica acutiloba extract had the effect of alleviating or treating the experimental allergic dermatitis, and it was concluded that the high dose was more effective.

• Biomolecules & Therapeutics
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• 제2권2호
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• pp.114-119
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• 1994

[$^3$H]Ouabain binding parameters ( $K_{D}$ and $B_{max}$) to control rat ventricular strips and Langendorff preparations which were not previously exposed to ouabain were compared with those to both preparations that had been first exposed to a complete ouabain dose range of dose-response curve (10$^{-8}$ to 10$^{4}$M). In rat ventricular strips and Langendorff perfused heart preparations, cumulative dose-response curves of ouabain revealed biphasic positive inotropic effects, a "low-dose" effect and a "high-dose" effect with E $d_{50}$ values of 0.5 $\mu$M and 35 $\mu$M ouabain, respectively. The "low-dose" effect in ventricular strip disappeared or was diminished significantly when the ouabain dose-response curve was repeated after the washout of the effects of the first dose-response curve, whereas there were no significant differences in the maximal "high-dose"effect in both exposures to oubain. However, both of the control and ouabain-preexposed Langendorff perfused hearts revealed the same low-dose effects. The $K_{D}$ value for [$^3$H] ouabain binding and the ouabain binding site concentration ( $B_{max}$) estimated by [$^3$H]ouabain displacement assay in control preparations were 230 nM and 2 pmol/mg protein, respectively. [$^3$H]Ouabain binding parameters were not changed by repeated exposure to high concentrations of ouabain. These results suggest that digitalis receptor desensitization in the rat ventricular strip may due to the change of post-receptor events induced by ouabain binding to a high affinity site ($\alpha$$_2$isoform).).).).).

• 약학회지
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• 제50권2호
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• pp.84-92
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• 2006

The present study investigated an effect of arsenic trioxide on the urethane-induced lung carcinogenesis in mice. To understand its carcinogenesis, we examined proliferating cell nuclear antigen (PCNA), apoptotic index as well as cell cycle-related proteins (cyclin D1, p21, and p27). Urethane was injected intraperitoneally in ICR mice, and then they were sacrificed at 5, 15, or 25 weeks following treatment of arsenic trioxide. Arsenic trioxide was given with tap water at a concentration of 1 mg/l (low-dose) and 5mg/1 (high-dose) for 25 weeks. During the carcinogenesis, sequential histological changes from hyperplasia to adenomas, and ultimately to overt carcinomas were noted. The development of hyperplasias, adenomas, and carcinomas in the lung were slightly increased by the treatment of low-dose arsenic trioxide. However, there is no correlation between dose and tumor multiplicity. The administration of low-dose arsenic trioxide, significantly increased the tumor size. The proliferative index observed on 5 weeks after significantly increased. Cyclin D1 and p21 protein, cell cycle related proteins, were more significantly increased in hyperplasia and adenoma in low dose arsenic treated group than urethane alone group. The p27 protein expression did not show any significantly changes with arsenic treated or untreated group. Low dose exposure to arsenic trioxide resulted in increased expression of cyclin D1 and p21 protein. The present results indicate that low-dose treatment of arsenic trioxide, but not high dose of it, partly modulate the cellular proliferation, cyclin D1, and p21 protein expression, and that this effect may contribute to accelerated development of lung adenocarcinomas in urethane-induced mice.

• Journal of Radiation Protection and Research
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• 제20권2호
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• pp.97-102
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• 1995

인체 말초 혈액 림프구에서 저선량의 감마선에 의해 유도되는 적응 반응을 관찰하였다. 인체 림프구를 저선량의 감마선(priming dose 0.01Gy) 을 조사한 후 여러 시간 간격 후 고선량 (challenging dose, 1.5Gy) 을 조사하였다. 저선량을 미리 조사한 림프구와 조사하지 않은 림프구에서 발생된 미세핵의 빈도를 계수하였다. 비세핵 발생 빈도는 저선량 조사 4시간 후 고선량을 조사하였을 때 최대 감소치를 보였다. 저선량과 고선량 조사 시간차가 7시간 또는 20시간이었을 때 미세핵 발생 빈도는 약간 감소하였으나 유의성은 없었다. 본 연구에서는 $G_0$상태의 세포주기에서 저선량을 조사하였을 경우 적응 반응이 나타나는 것이 관찰 되었다. 미세핵 분석법은 실험 방법이 비교적 간단하고, 기타 염색체 분석법에 비하여 빠른 시간내 결과를 도출 할 수 있어 추후 방사선에 대한 적응 반응의 연구에 유용한 지표가 될 수 있을 것이다.

• 대한약학회:학술대회논문집
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• 대한약학회 2002년도 Proceedings of the Convention of the Pharmaceutical Society of Korea Vol.2
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• pp.261.2-261.2
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• 2002

Hypoglycemic effect of GRA was examined in multiple low dose(MLD) streptozotocin(STZ)-induced diabetic rats with regard to time of administration. Experimental methods: 20 mg/kg of STZ in 100 mM citrate buffer(pH 4.5) was injected intraperitoneally for 5 consecutive days. In co-treatment groups, GRA was administered intraperitoneally for 3 weeks at dose of 150 or 300 kg/kg. (omitted)

• The Korean Journal of Pain
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• 제22권3호
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• pp.224-228
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• 2009

Background: Shoulder arthroscopic surgery is frequently associated with severe postoperative pain, which can be difficult to manage without the use of high-dose opioids. Although an interscalene brachial plexus block (ISBPB) can be used to provide anesthesia for shoulder arthroscopic surgery, its effect using low-dose mepivacaine on postoperative pain management has not been reported. We hypothesized that ISBPB using a low-dose mepivacaine can provide effective postoperative analgesia for shoulder arthroscopic surgery without the need for high-dose opioids and act as a significant motor or sensory block. Methods: This study examined a total of 40 patients, who underwent shoulder arthroscopic surgery, and received ISBPB with 10 ml of normal saline (group NS; n = 20) or 10 ml of 1% mepivacaine with epinephrine 1:200,000 (group MC; n = 20). The block was performed preoperatively. The postoperative pain score, opioid consumption, and side effect were recorded. Results: The visual analog scale scores were significantly lower in group MC than in group NS at 120 minutes after shoulder arthroscopic surgery ($1.9{\pm}1.0$ versus $4.0{\pm}1.4$). Group MC showed significantly lower fentanyl consumption after shoulder arthroscoic surgery than group NS ($27{\pm}32.6$ versus $79{\pm}18.9{\mu}g$). The degree of motor and sensory block after surgery was minimal. Conclusions: ISBPB using low-dose mepivacaine reduced the level of postoperative pain and fentanyl consumption without significant side effects. ISBPB using low-dose mepivacaine is a useful analgesic technique for shoulder arthroscopic surgery.