• Toxicological Research
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• v.8 no.2
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• pp.235-253
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• 1992

A subacute toxicity study of cis-Malonato[(4R,5R)-4,5-bis(aminomethyl)-2-isopropyl-1,3-dioxolane]platinum(II)(SKI 2053R) was carried out to obtain information on its toxicological profiles, and to determine the maximum tolerated dose in beagle dogs. Four groups of beagle dogs (2M and 2F per group, 0,0.5,1.0,2.0mg/kg/day)were given 15 i.v. injections of SKI 2053R. In order to compare the toxic effects of SKI 2053R with those of cisplatin, one group was treated with cisplatin(0.7mg/kg/day)according to the same treatment schedule. The dosing schedule was divided into 3 courses of 5 consecutive days with 23-day dose-free intervals between each course. After completion of the treatments, remaining dogs were necropsied under established guidelines. Three of four dogs in the high dose group and one of four dogs in the middle dose group treated with SKI 2053R died of hypovolemic shock secondary to hemorrhagic and ulcerative enterocolitis. No toxicity-related mortality occurred in the low dose group of SKI 2053R. No survivor was observed in the group of cisplatin. Clinical signs including vomiting, diarrhea, anorexia and loss body weight were apparent in dogs given either cisplatin or high and middle doses of SKI 2053R. Severe thrombocytopenia and leukocytopenia were observed in the high dose group of SKI 2053R and cisplatin-treatment group, while toxicities as bone marrow suppression were reversible. The significant elevation of serum ALP values in group of SKI 2053R(2.0 mg/kg/day and 1.0mg/kg/day) and cisplatin(0.7mg/kg/day)was observed. Slight proteinuria waa observed in high and middle dose level groups of SKI 2053R. In histopathological examinations, pathological alterations of liver, kidney and spleen were noted dose-dependantly in dogs treated with SKI 2053R, and there was no overt sign of toxicity in low dose group of SKI 2053R. Compared to SKI 2053R, more severe durg-related toxicities occurred in dogs treated with cisplatin. It waw estimated that maximum tolerated dose of SKI 2053R in this treatment schedule was 0.5~0.7mg/kg/day. In conclusion, overall toxic potential of SKI 2053R was approximately 3 times lower than that of cisplatin with respect of lethality.

• Radiation Oncology Journal
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• v.7 no.2
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• pp.171-183
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• 1989

A general effect for cell proliferation has been incorporated into Roesch's survival equation (Accumulation Model). From this an isoeffect formula for the low dose-rate regimen is obtained. The prediction for total doses equivalent to 60Gy delivered at the constant dose-rate over 7 days agrees well with the dose-time data of Paterson and of Green, when the parameter ratio A/B (${\approx}{\alpha{\mu}}/2{\beta}\;where\;{\mu}$ is the repair rate) is chosen to be 0.7Gy/h. When a constant proliferation rate and known facts of division delay are assumed, an isoeffect relation between low dose-rate treatment and acute dose-rate treatment can be derived. This formula in the regimens where proliferation is negligible predicts exactly the data of Ellis that 8 fractions of 5 Gy/day for 7 days are equivalent to continuously applied 60Gy over 7days, provided the A/B ratio is 0.7 Gy/h and the $\alpha/\beta$ ratio is 4Gy. Overall agreement between the clinical data and the predictions made by the formula at the above parameter values suggests that the biologcal end points used as the tolerance level in the studies by Paterson, Green, and Ellis all agree and they are not entirely the early effects as generally assumed. The absence of dose-rate effects observed in the mouse KHT sarcoma can better be explained in terms of a large value for the A/B ratio. Similarly, the same total dose used independently of the dose-rate to treat head and neck tumors by Pierquin can be justified.

• Korean Journal of Digital Imaging in Medicine
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• v.14 no.2
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• pp.15-22
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• 2012

The purpose of this study was to measure the absorbed dose and calculate the effective dose for cone beam computed tomography (CBCT) and panorama units and to estimate usefulness of x-ray protective. Rando phantom and glass dosimeters were used for dosimetry. The absorbed doses were measured at 15 organs and 14 remainder from correspond to ICRP 2007 recommendations. The absorbed dose was highest in salivary glands as measured CBCT 2.420mGy, panorama 0.307mGy. Absorbed dose in another organs were high in order of thyroid, brain, skin, esophagus. The effective dose was CBCT 0.100mSv, panorama 0.011mSv and effective dose of panorama was higher than that of CBCT by 10 times. In case of wearing x-ray protective, reducing effective dose of CBCT by 0.066mSv (66%) and panorama by 0.008mSv (72%). Effective dose were reduced by radiological shielding but it needs further optimization studies, where dosimetric data are analyzed in combination with image quality with keep the patients' exposure as low as possible.

• The Korean Journal of Nuclear Medicine Technology
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• v.27 no.1
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• pp.29-35
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• 2023

Purpose The concentration of PSA (Prostate Specific Antigen) after radical prostatectomy in prostate cancer patients is a predictor of biochemical recurrence, and the AUA (American Urological Association) is defined as biochemical recurrence when the concentration of PSA is measured at 0.2 ng/mL or more, and when the concentration is measured at 0.2 ng/mL or more at the retest. This standard is also applied our hospital. In this laboratory, the PSA reagent using IRMA (Immunoradiometric Assay) is used, and the sensitivity at a very low value was not as good as the reagent used in the department of laboratory medicine. This study aims to increase the reliability of the results by improving the precision and sensitivity of very low values. Materials and Methods As a reagent for the study, PSA reagent using IRMA was used. As a method to improve the precision and sensitivity of very low values, a variation method on the serum volume(25 uL, 50 uL, 100 uL, 200 uL) was studied, and variation usefulness evaluation was conducted. The evaluation items were compared the results of precision, analytical sensitivity, recovery rate, dilution test, high-dose hook effect test, parallel test and very low concentration values(n = 20). Results The validation results were displayed in the order of 25 uL, 50 uL, 100 uL, 200 uL. As the serum volume increased, it was confirmed that CV (Coefficient of Variation)(%) improved. Analytical sensitivity(ng/mL) was 0.038, 0.041, 0.017, 0.015 and recovery rate(%) was 101±3, 101±3, 99±2, 97±4. very low concentration values(ng/mL) between each volume(n=20) were 0.135±0.068, 0.076±0.050, 0.048±0.034, 0.046±0.034. and high dose hook effect appeared as the serum volume increased. Conclusion Through the variation usefulness evaluation, it was confirmed that as the serum volume increased, the precision and sensitivity improved at very low concentration values. However, it is necessary to pay special attention to the occurrence of high-dose hook effect as the serum volume increases. In the case of tests that requires very low concentration values, it is thought that the reliability of the result will be increased if the variation method is properly used after the variation usefulness evaluation.

• The Korean Journal of Physiology
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• v.19 no.1
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• pp.1-13
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• 1985

The influences of $Ca^{2+}-antagonists$, verapamil and $Mn^{2+}$, upon the spontaneous electrical activity and contractions were studied in guinea-pig taenia coli. Spontaneous contractions were recorded with force transducer, and spike action potentials were measured extracellularly by use of suction electrode. All experiments were performed in tris-buffered Tyrode solution Which was aerated With 100% $O_2$ and kept at $35^{\circ}C$. The results obtained were as follows : 1) Verapamil suppressed the frequency and amplitude of spontaneous contractions dose dependently, and blocked completely mechanical responses at the concentration of 1 mg/1. 2) The frequency of bursts of spike discharge(bursts frequency) and the number of spikes in a burst(spikes frequency) were reduced in a dose·dependent manner within the concentration range of $10^{-5}$ to $10^{-3}g/l$, and bursts frequency was affected more readily at a low concentration of $10^{-5}g/l$ verapamil. 3) The verapamil_induced suppression of spontaneous contractions in the Tyrode solution containing 1 mM $Ca^{2+}$ was completely antagonized by the addition of extra $Ca^{2+}$ to the Tyrode solution $(2\;m\;MCa^{2+})$. 4) $Mn^{2+}$ suppressed the amplitude of spontaneous contractions, whereas $Mn^{2+}$ accelerated the frequency dose-dependently within the range of low concentrations$(10^{-7}\;to\;10^{-4}\;M\;Mn^{2+})$. 5) The bursts frequency determining frequency of spontaneous contractions was increased in a dose-dependent manner, whereas the spikes frequency known to determine the contractions amplitude was reduced within the range of low concentrations. At a high concentration of 1 mM $Mn^{2+}$, however, all spontaneous contractile responses were blocked simultaneously with the disapperance of electrical activity. 6) The frequency and amplitude of spontaneous contractions altered by $Mn^{2+}$ in 1mM $Ca^{2+}$ Tyrode were increased by extra $Ca^{2+}(2mM)$.

• Clinical and Experimental Pediatrics
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• v.60 no.12
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• pp.403-407
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• 2017

Purpose: Quadriplegic children with cerebral palsy are more susceptible to osteoporosis because of various risk factors that interfere with bone metabolism. Pamidronate is effective for pediatric osteoporosis, but there are no guidelines for optimal dosage or duration of treatment in quadriplegic children with osteoporosis. We aimed to evaluate the efficacy of low-dose pamidronate treatment in these patients. Methods: Ten quadriplegic patients on antiepileptic drugs (6 male, 4 female patients; mean age, $10.9{\pm}5.76years$), with osteoporosis and gross motor function classification system level V, were treated with pamidronate (0.5-1.0 mg/kg/day, 2 consecutive days) every 3-4 months in a single institution. The patients received oral supplements of calcium and vitamin D before and during treatment. The lumbar spine bone mineral density (BMD) z score and biochemical markers of bone metabolism were measured regularly during treatment. Results: The main underlying disorder was perinatal hypoxic brain damage (40%, 4 of 10). The mean cumulative dose of pamidronate was $4.49{\pm}2.22mg/kg/yr$, and the mean treatment period was $10.8{\pm}3.32months$. The BMD z score of the lumbar spine showed a significant increase from $-4.22{\pm}1.24$ before treatment to $-2.61{\pm}1.69$ during treatment (P=0.008). Alkaline phosphatase decreased during treatment (P=0.037). Significant adverse drug reactions and new fractures were not reported. Conclusion: Low-dose pamidronate treatment for quadriplegic children with cerebral palsy increased lumbar BMD and reduced the incidence of fracture.

• Korean Journal of Environmental Agriculture
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• v.18 no.1
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• pp.66-69
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• 1999

To investigate the hormetic effect of the low dose ${\gamma}-ray$, soybean(Glycine max L.) seeds of three cultivars (Hwangkeumkong, Bansakong, S900 cv.) were irradiated with the dose of 0.5∼20.0 Gy and cultivated in the experimental field. The hormetic effects of the low dose ${\gamma}-ray$ on the growth of field experiment were different from each cultivar, that is, more effective in the S900 cultivar of black seedcoat color than in the Hwangkeumkong and Bangsakong of yellow ones. The germination rate of S900 cultivar increased about 30% in the 0.5Gy irradiated group compared with that of the control. The plant height of the 4.0Gy irradiated group in both Bangsakong and S900 cultivar increased 15% more than that of the control. Grain yield and the number of pod in 1.0 Gy and 4.0 Gy irradiated group of S900 cultivar and that of 2.0 Gy irradiated group of Hwangkeumkong increased 25 and 35% on the average, respectively.

• Korean Journal of Environmental Biology
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• v.17 no.1
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• pp.11-15
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• 1999

To investigate the stimulating effects of the low- dose radiation, the seeds of chinese cabbages (Brassica campestris L. cv. Hanyoreum and cv. Tropic emperor) were irradiated at the dose of 0.5 Gy~20 Gy with the ${\gamma}$-ray radition. In case of ‘Hanyoreum’cultivar, there were no significant promoting effects on the germination rate except the 0.5 Gy irradiated group. The increase in seedling height and fresh weight in 8 Gy and 12 Gy irradiated groups was 20% and 40%, respectively, which suggested the stimulating effect of the low-dose radiation on the early growth. In case of‘Tropic emperor’cultivar, the germination rate of 1 Gy irradiated group increased approximately 10% and the seedling height and fresh weight of 1 Gy and 12 Gy irradiated group in the greenhouse 20% on the average, and plant height and fresh weight of 0.5 Gy and 4 Gy irradiated group in the field increased 10% and 20% on the average, respectively.

• Archives of Pharmacal Research
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• v.19 no.5
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• pp.381-385
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• 1996

Rat ventricles respond with a biphasic positive inotropic effect to ouabain, low-dose and high-dose effects but rat atria with only a monophasic high dose effect. In an effect to understand the difference in response to ouabain of two tissues between rat atria and ventricles the levels of the $a_{2}$ -isoform of the $Na^{+}$, $K^{+}$-ATPase which has higher affinity for ouabain than the $a_{1}$-iso-form were determined by a $[^{3}H]$ouabain binding assay. The yield of protein per gram wet weight was about 47 mg for atria and 100 mg for ventricles. The $K_{d}$ values of ouabain for the high-affinity ouabain binding site $(a_{2} -isoform)$ were nearly the same (230 nM) in the atria and ventricles. However, the numbers of the $a_{2}$-isoform $(B_{max})$ per mg protein were approximately half in the atria. When the binding data were expressed in unit per gram tissue wet weight, the numbers of $a_{2}$ -isoform in the atria was about 25% of that in the ventricles. THese results demonstrate that the $a_{2}$ -isoform of the $Na^{+}$, $K^{+}$-ATPase in the rat atria could be detected by $[^{3}H]$ouabain binding assay and the levels of this isoform are too low to show the low-dose effect of ouabain.

• Development and Reproduction
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• v.23 no.2
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• pp.93-99
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• 2019

Nonylphenols (NPs) are widely used industrial materials, and are considered as potent endocrine disrupting chemical. Present study was undertaken to clarify the effect of subchronic low-dose NP exposure to F1 generation male mice. Mice were divided into 2 groups; (1) CON, control animals and (2) NP-50 ($50{\mu}g/L$), animals were treated with NP via drinking water. NP exposures were continuously conducted from parental pre-mating period until the postnatal day (PND) 55 of F1 offsprings. Mice were sacrificed on PND 55 and the tissue weights were measured. The initial body weights (at PND 21) and terminal body weights (PND 55) of the NP-50 animals were significantly lower than those of control animals (p<0.05). NP exposure induced a significant increase in the absolute weight of the testes (p<0.05). Conversely, the NP exposure caused significant decrease in the absolute weights of the epididymis (p<0.01), prostate (p<0.05) and seminal vesicle (p<0.05). Histopathological studies revealed that NP-treated animals exerted decreased seminiferous tubule diameters, reduced luminal area, and lower number of germ cells. Also some sloughing morphologies in the tubules were observed. In the caudal epididymis, fewer mature sperms and swollen epithelial cells were found in the NP-treated group. Our results confirmed that the subchronic low-dose NP exposure altered some male parameters and induced histopathological abnormalities in testis and epididymis of F1 mice. Since the NP dose used in this study is close to the average human daily NP exposure, our results could provide practically meaningful understanding of adverse effect of EDC in human.