• Journal of Microbiology and Biotechnology
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• v.11 no.3
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• pp.524-528
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• 2001

The measurement of radiation response using simple and informative techniques would be of great value in studying the genetic risk following occupational, therapeutic, or accidental exposure to radiation. When patients receive radiation therapy, many suffer from side effects. Since each patient receives a different dose due to different physical conditions, it is important to measure the exact dose of radiation received by each patient to lessen the side effects. Even though several biological dosimetric systems have already been developed, there is no ideal system that can satisfy all the criteria for an idean dosimetric system, especially for low-dose radiation as used in radiation therapy. In this study, an SOS Chromotest of E. coli PQ37 was evaluated as a novel dosimeter for low-dose gamma-rays. E. coli PQ37 was originally developed to screen chemical mutagens using the SOS Chromotest-a colorimtric assay, based on the induction of ${\beta}$-galactosidase ue to DNA damage. The survival fraction of E. coli PQ37 decreased dose-dependently with an increasing dose of cobalt-60 gamma-rays. Also, a good linear correlation was found between the biological damage revealed by the ${\beta}$-galactosidase expression and the doses of gamma-rays. The expression of ${\beta}$-galactosidase activity that responded to low-dose radiation under 1 Gy was $Y=0.404+(0.089{\pm}0.3)D+(-0.018{\pm}0.16)D^2$ (Y, absorbance at 420 nm; D, Dose of irradiation) as calculated using Graph Pad In Plot and Excel. When a rabbit was fed with capsules containing an agar block embdded with E. coli PQ37 showed a linear response to the radiation doses. Accordingly, the results confirm that E. coli PQ37 can be used as a sensitive biological dosimeter fro cobalt-60 gamma-rays. To the best of our knowledge, this is the first time that a bacterium has been used as a biological dosimeter, especially for low-dose radiation.

• Journal of Microbiology and Biotechnology
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• v.33 no.6
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• pp.806-822
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• 2023

In the current study we assessed a new crystallized compound, 5-(1-hydroxybutyl)-4-methoxy-3-methyl-2H-pyran-2-one (C-HMMP), from the endophytic fungus Colletotrichum acutatum residing in the medicinal plant Angelica sinensis for its in vitro antimicrobial, antibiofilm, antioxidant, antimalarial, and anti-proliferative properties. The promising compound was identified as C-HMMP through antimicrobial-guided fraction. The structure of C-HMMP was unambiguously confirmed by 2D NMR and HIRS spectroscopic analysis. Antimicrobial property testing of C-HMMP showed it to be effective against a variety of pathogenic bacteria and fungi with MICs ranging from 3.9 to 31.25 ㎍/ml. The compound displayed excellent antibiofilm activity against C. albicans, S. aureus, and K. pneumonia. Furthermore, the antimalarial and radical scavenging activities of C-HMMP were clearly dosedependent, with IC50 values of 0.15 and 131.2 ㎍/ml. The anti-proliferative activity of C-HMMP against the HepG-2, HeLa, and MCF-7 cell lines in vitro was investigated by MTT assay, revealing notable anti-proliferative activity with IC50 values of 114.1, 90, and 133.6 ㎍/ml, respectively. Moreover, CHMMP successfully targets topoisomerase I and demonstrated beneficial anti-mutagenicity in the Ames test against the reactive carcinogenic mutagen, 2-aminofluorene (2-AF). Finally, the compound inhibited the activity of α-glucosidase and α-amylase with IC50 values of 144.7 and 118.6 ㎍/ml, respectively. To the best of our knowledge, the identified compound C-HMMP was obtained for the first time from C. acutatum of A. sinensis, and this study demonstrated that C-HMMP has relevant biological significance and could provide better therapeutic targets against disease.

• Journal of the Korean Wood Science and Technology
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• v.37 no.1
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• pp.114-120
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• 2009

The bark of Populus alba ${\times}$ glandulosa was collected, air-dried and extracted with 70% aqueous acetone. Then it was successively partitioned with n-hexane, $CH_2Cl_2$, EtOAc and $H_2O$. Repeated Sephadex LH-20 column chromatography and preparative TLC on the EtOAc soluble fraction gave a grandidentatin isomer. The structure was elucidated as grandidentatin A (cis-2-hydroxycyclohexyl 6-O-p-coumaroyl-${\beta}$-D-glucopyranoside) on the basis of spectroscopic evidences such as $^1H$-NMR, $^{13}C$-NMR, 2D-NMR and MALDI TOF-MS spectrum followed by acid hydrolysis. Grandidentatin A was identified here for the first time in Populus alba ${\times}$ glandulosa bark, and to the bset of our knowledge it has not been reported in any other literature.

• Journal of Ginseng Research
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• v.40 no.3
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• pp.237-244
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• 2016

Background: Ginsenoside Rg3 and arginine-fructose (Arg-Fru) are known as the hypotensive compounds of Panax ginseng; however, their efficacy on antihypertension has not been reported yet to our best knowledge. Thus, hypotensive components-enriched fraction of red ginseng (HCEF-RG) was prepared from fine root concentrate (FR) and their antihypertensive effects were investigated in spontaneously hypertensive rats (SHR). Methods: Male SHRs were divided into six groups: control (Wistar Kyoto, SHR); FR 500; FR 1,000; HCEF-RG 500; and HCEF-RG 1,000; samples (mg/kg body weight) were orally administered every day for 8 wk. Blood pressure was monitored at 1 wk, 2 wk, 3 wk, 4 wk, 6 wk, and 8 wk by tail cuff method. At 8 wk after samples administration, mice were killed for the measurement of renin activity (RA), angiotensin-I converting enzyme inhibition, angiotensin II, and nitric oxide (NO) levels in plasma. Results: HCEF-RG with four-fold more Rg3 and 24-fold more Arg-Fru contents was successfully prepared from reacted mixtures of FR and persimmon vinegar (12 times against FR, v/v) at $80^{\circ}C$ for 18 h. Both FR 1,000 and HCEF-RG 1,000 showed lowered systolic blood pressure than SHR control group and HCEF-RG 1,000 group exhibited a significant decrease in diastolic blood pressure. RA was significantly lowered in all treated groups, while angiotensin II did not affect by FR and HCEF-RG treatment. However, angiotensin-I converting enzyme inhibition and NO in FR 1,000 and HCEF-RG 1,000 were significantly increased compared with SHR control group. Conclusion: HCEF-RG is more effective and useful for alleviating hypertension than FR, implying the health benefit of Rg3 and Arg-Fru.

• The Korean Journal of Physiology and Pharmacology
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• v.23 no.4
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• pp.231-236
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• 2019

In drug discovery or preclinical stages of development, potency parameters such as $IC_{50}$, $K_i$, or $K_d$ in vitro have been routinely used to predict the parameters of efficacious exposure (AUC, $C_{min}$, etc.) in humans. However, to our knowledge, the fundamental assumption that the potency in vitro is correlated with the efficacious concentration in vivo in humans has not been investigated extensively. Thus, the present review examined this assumption by comparing a wide range of published pharmacokinetic (PK) and potency data. If the drug potency in vitro and its in vivo effectiveness in humans are well correlated, the steady-state average unbound concentrations in humans [$C_{u_-ss.avg}=f_u{\cdot}F{\cdot}Dose/(CL{\cdot}{\tau})=f_u{\cdot}AUCss/{\tau}$] after treatment with approved dosage regimens should be higher than, or at least comparable to, the potency parameters assessed in vitro. We reviewed the ratios of $C_{u_-ss.avg}$/potency in vitro for a total of 54 drug entities (13 major therapeutic classes) using the dosage, PK, and in vitro potency reported in the published literature. For 54 drugs, the $C_{u_-ss.avg}$/in vitro potency ratios were < 1 for 38 (69%) and < 0.1 for 22 (34%) drugs. When the ratios were plotted against $f_u$ (unbound fraction), "ratio < 1" was predominant for drugs with high protein binding (90% of drugs with $f_u{\leq}5%$; i.e., 28 of 31 drugs). Thus, predicting the in vivo efficacious unbound concentrations in humans using only in vitro potency data and $f_u$ should be avoided, especially for molecules with high protein binding.

• Journal of Educational Research in Mathematics
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• v.17 no.4
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• pp.359-380
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• 2007

This study was conducted with two 6-graders to identify how were their proportional reasoning abilities, whether they evolved proportional thinking in a various context, and what had influence on their proportional thinking. The findings, as previous researches noted, suggested that the proportional expression obtaining by instrumental understanding could not provide rich opportunities for students to improve understanding about ratio and proportion and proportional reasoning abilities, while being useful for determining the answers. The students were able to solve proportional problems with incorporating their knowledge of divisor, multiples, and fraction into proportional situations, but not the lack of number sense. The students easily solved proportional problems experienced in math and other subjects but they did not notice proposition in problems with unfamiliar contexts.

• The Korean Journal of Pharmacology
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• v.9 no.1
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• pp.1-21
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• 1973

During the last decade extensive studios on catecholamines have evolved new knowledge in the physiology and biochemistry of adrenergic mechanism. Cardiac muscle, receiving adrenergic fibres from the stellate, cervical and thoracic ganglia, has been repeatedly shown to have a specific capacity to uptake and to store catecholamines. The catecholamine stores in cardiac muscle have also been shown to be important sites for the action of numerous drugs. Under normal condition, a certain level of catecholamines is maintained in the stores and serves as the basis for studying the changes in the catecholamine content of the heart. Because myocardial catecholamines play such important role in the patho-physiology of the heart, it would be interesting to compare the normal level of myocardial catecholamines among various species of animals. An occasional study has dealt with myocardial catecholamines of several species add ages of animals but these have been insufficiently comprehensive to afford a basis for an understanding of the importance of these amines as related to species and ages. The present investigation was undertaken to determine whether or not there is any significance of myocardial catecholamines in the course of the evolution and development of animals. Seasonal changes, sex difference and regional and subcellular distribution of myocardial catecholamines were also examined. The concentration of cardiac catecholamines was determined by the spectrophotofluorometric procedure described by Shore and Olin. The results obtained were summarized as follows: 1. As animals phylogenetically progressed larger amounts of catecholamines were resent in their hearts. A negligibly small amount of catecholamine was present in the hearts of the clam, a non-vertebrate. Among the vertebrates, cold-blooded animals (snake, turtle, frog, eel and fish) had less myocardial catecholamines than warm-blooded animals, of which aves (fowl and duck) had less than mammalia (cat, dog, rabbit, rat, cow and pig). The ratio of norepinephrine to epinephrine also was greater as the animals progress phylogenetically. 2. Examination of the regional distribution of cardiac catecholamines in warm-blooded animals showed that the content of the auricle was generally higher than that of the septum and considerably than that of the ventricle, but the differences of contents among these regions were not so marked. 3. In the embryonic chick, cardiac catecholamines were firstly detected on the 4th day of incubation, the time before the cardiac innervation of sympathetic nerves. The concentrations of these catecholamines increased but not markedly on the 6th day of incubation, soon after the innervation of sympathetic nerves to the heart. The level of the cardiac catecholamines fluctuated throughout the remainder of embryonic development. 4. In newborn rat hearts, a considerable amount of catecholamines was present. With the development of the rats, the concentrations of myocardial catecholamines increased. The ratio of epinephrine and norepinephrine fluctuated within the range of 40 to 60 pervent. However, as development progressed, the percentage of norepinephrine continued to rise, attaining the adult value of $80{\sim}90%$ after $45{\sim}60$ days. In contrast, the total amount of epinephrine remained fairly constant throughout the animal's development. 5. No significant sexual differences were observed in the concentration of myocardial catecholamines in the developing rat. 6. The catecholamines in the rabbit hearts increased during the summer season (from May to August) and maintained a fairly constant level in the other seasons of the year. 7. The subcellular distribution of cardiac catecholamines was examined by differential centrifugation of homogenates of cardiac muscles in rabbits, cats and rats. The catecholamines were found to be present approximately 20% in particles of mitochondrial fraction, 45% in particles of microsomal fraction and 35% in soluble supernatant fraction. The particle containing catecholamines in cardiac muscle appears to be two different sizes.

• Korean Journal of Animal Reproduction
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• v.9 no.2
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• pp.133-139
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• 1985

An immunoassay may be defined as an analytical procedure involving the competitive reaction between a limiting concentration of specific antibody and two populations of antigen, one of which is labelled or immobillized. The advent of immunoassay has revolutionised our knowledge of reproductive physiology and the practice of veterinary and clinical medicine. Radioimmunoassay (RIA) was the first of these methods to be developed, which meausred the analyte with good sensitivity, accuracy and precision (1,2). The essential components of RIA are:-(i) a limited concentration of antibodies, (ii) a reference preparation, and (iii) an antigen labelled with a radioisotope (usually tritium or iodine-125). Most procedures invelove isolating the antibody-bound fraction and measuring the amount of labelled antigen. Good facilities are available for scintilltion counting, data reduction nd statistical analysis. RIA is undergoing refinement through:-(i) the introduction of new techniques to separate the antibody-bound and free fractions which minimize the misclassification of labelled antigen into these compartments, and the amount of non-specfic binding. (3), (ii) the development of non-extration for the measurement of haptens (4), (iii) the determination of a, pp.rent free (i.e. non-protein bound) analytes (5), and (iv) the use of monoclonal antibodies(6). In 1968, Miles and Hales introduced in important new type of immunoassay which they termed immunora-diometric assay (IRMA) based on t도 use of isotopically labelled specific antibodies(7) in a move from limited to excess reagent systems. The concept of two-site IRMAs (with a capture antibody on a solid-phase, and a second labelled antibody to a different antigenic determinant of the analyte) has enabled the development of more sensitive and less-time consuming methods for the measurement of protein hormones ovar wide concentration of analyte (8). The increasing use of isotopic methos for diverse a, pp.ications has exposed several problems. For example, the radioactive half-life and radiolysis of the labelled reagent limits assay sensitivity and imposes a time limit on the usefulness of a kit. In addition, the potential health hazards associated with the use and disposal of radioactive cmpounds and the solvents and photofluors necessary for liquid scientillation counting are incompatable with the development of extra-laboratory tests. To date, the most practical alternative labels to radioisotopes, for the measurement of analytes in a concentration > 1 ng/ml, are erythrocytes, polystyrene particiles, gold sols, dyes and enzymes or cofactors with a visual or colorimetric end-point(9). Increased sensitivity to<1 pg/ml may be obtained with fluorescent and chemiluminescent labels, or enzymes with a fluorometric, chemiluminometric or bioluminometric end-point. The sensitivity of any immunoassay or immunometric assay depends on the affinity of the antibody-antigen reaction, the specific activity of the label, the precision with which the reagents are manipulated and the nonspecific background signal (10). The sensitivity of a limited reagent system for the measurement of haptens or proteins is mainly dependent upon the affinity of the antibodies and the smalleest amount of reagent that may be manipulated. Consequently, it is difficult in practice to improve on the sensitivity obtained with iodine-125 as the label. Conversely, with excess reagent systems for the measurement of proteins it is theoretically possible to increase assay sensitivity at least 1000 fold with alternative luminescent labels. To date, a 10-fold improvement has been achieved, and attempts are being made to reduce the influence of other variables on the specific signal from the immunoreaction.

• Korean Journal of Social Welfare
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• v.35
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• pp.1-30
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• 1998

The primary objectives of this research is to identify (1) demographic and behavioral characteristics of donors for social welfare organizations in Korea and (2) factors that predicts the degrees of donors' philanthropic effort measured by the fraction of personal income given to these organizations. This study uses the data based on the responses of 191 participants among 500 donors selected randomly from the donor population of 5 major social welfare organizations. In the demographic aspect, this study showed that donors have higher frequencies in college education, Christianity, married status, age of 30s & 40s, and middle class. In the behavioral aspect, this study showed that donors have higher frequencies in inner motivation for philanthropic participation ("joy of giving"), satisfaction about the activities of social welfare organizations, trust toward funds administration of social welfare organizations, and active participation ("solicitation to others") about donation. This study also showed that donor's duration is distributed around 3 years (median) and donors' donation amount is distributed around 20,000 Won (median). This study found that the median value of donors' philanthropic effort is 1.2 percent and the distribution of philanthropic effort by income has the U shape. Finally, using polynomial regression analysis, this study found that the first power and second power of donor's income, age, continuation motivation of donation, and degree of active participation are statistically significant in predicting the degree of donors' philanthropic effort. This study will contribute to expanding knowledge about donors' characteristics and provide a practical implication for financial resource mobilization strategies in nonprofit nongovernmental sector.

• Economic and Environmental Geology
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• v.38 no.2 s.171
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• pp.165-176
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• 2005

Natural gas in deep sediment may occur in three phases based on the physical and chemical conditions. If the concentration of gas in pore water is less than the solubility, gas is dissolved. If the concentration of gas is greater than its solubility (water is saturated or supersaturated with gas), gas occurs as a fee gas below the gas hydrate stability Lone (GHSZ) and is present as solid hydrate within the GHSZ. The knowledge of gas concentration in deep sediment appears critical to determine the phase of natural gases and to understand the formation and distribution of gas hydrate. However, reliable data on gas concentration are usually available only from the upper section of marine sediment by the headspace gas technique, which is widely used for sampling of gases from the sediments. The headspace gas technique represents only a fraction of gases present in situ because sediments release most of the gases during recovery and sampling. The PCS (Pressure Core Sampler) is a downhole tool developed to recover a nominal $1{\cal}m$ long, $4.32{\cal}cm$ diameter core containing $1,465cm^3$ of sediment, pore water and gas at in situ pressure up to 68.9 MPa. During Leg 204, the PCS was deployed at 6 Sites. In situ methane gas concentration and distribution of gas hydrate was measured by using PCS tool. Characteristics of methane concentration and distribution is different from site to site. Distribution of gas hydrate in the study area is closely related to characteristics of in situ gas concentration measured by PCS.