• The Korean Journal of Physiology
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• v.11 no.2
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• pp.9-16
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• 1977

The present experiment was conducted to see whether or not several cardioactive agents influence the 'regenerative $Ca^{++}$ release' in the mechanically disrupted cardiac cells. The mechanically disrupted cardiac cells were prepared by the method of Kerrick and Best from the ventricle of rat. The tension development of the disrupted cardiac cells was measured with a mechanoelectric transducer (RCA 5734). The results were summarized as follows 1) 2 mM caffeine enhanced the regenerative $Ca^{++}$ release, whereas 2 mM Procaine inhibited the $Ca^{++}$ release as reported by other investigators. 2) Epinephrine at concentrations of $10^{-7},\;10^{-6}\;and\;10^{-5}M$ increased the regenerative $Ca^{++}$ release significantly but showed a poor dose response on the $Ca^{++}$ release. 3) Propranolol showed no effect on the regenerative $Ca^{++}$ release when studied alone. Furthermore, it showed no antagonistic effect on an increased regenerative $Ca^{++}$ release induced by epinephrine. 4) Other cardioactive agents such as acetylcholine, ouabain, isoproterenol and c-AMP at concentrations of $10^{-6}M$ showed no effect on the regenerative $Ca^{++}$ release. From the above results, it may be concluded that the cardioactive actions of these agents are not related directly to the process of regenerative $Ca^{++}$ release.

• Progress in Superconductivity and Cryogenics
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• v.23 no.2
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• pp.10-13
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• 2021

Superconductor-ferromagnet thin film heterostructure is an ideal system for studying the interplay between superconductivity and ferromagnetism. These two antagonistic properties combined in thin film heterostructure create interesting proximity effects such as spin-triplet superconductivity. Thin film heterostructure of optimally doped La_2-xSr_xCuO₄(LSCO) cuprate superconductor and SrRuO₃(SRO) ruthenate ferromagnet has been grown by pulsed laser deposition. Its temperature-dependent resistivity and Hall effect measurements show that our LSCO/SRO heterostructure has both superconductivity and ferromagnetism. In the Hall effect measurement results, we find additional hump-like structures appear in the anomalous Hall effect signal in the vicinity of superconducting transition. We conclude that giant magnetoresistance of the LSCO layer distorts the AHE signal, which results in a hump-like structure.

• Journal of Veterinary Clinics
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• v.24 no.2
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• pp.104-108
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• 2007

The purpose of the study is to evaluate the clinical antagonistic effect of atipamezole(0.25 mg/kg, IM) in cats anesthetized with tiletamine-zolazepam ($Zoletil^{(R)}$, 10 mg/kg, IM) and medetomidine (0.05 mg/kg, IM). Twelve healthy 1 year old Korean mixed breed cats were used for this study. They were 4 males and 8 females. These cats were randomly assigned to two groups. One was control group ($Zoletil^{(R)}$ + medetomidine, ZM), and the other was treatment group ($Zoletil^{(R)}$ + medetomidine and antagonism by atipamezole, ZMA). All cats were examined 15 minutes before, 5, 25, 65 and 105 minutes after administration of tiletamine-zolazepam and medetomidine. Atipamezole was injected intramuscularly 20 minutes after ZM administation. Recovery time, heart rate, respiratory rate, total plasma protein and blood glucose were significantly different between ZM group and ZMA group (P<0.05). However, rectal temperature was not significantly different between ZM group and ZMA group. Two groups were able to induce sternal recumbency within 2 minutes and lateral recumbency within 4 minutes after the anesthetics injection. Mean sternal position time ($mean{\pm}SD$) was $174.0{\pm}44.6\;and\;116.2{\pm}27.3$ minutes, and mean standing position time was $210.8{\pm}45.6\;and\;154.2{\pm}21.1$ minutes in ZM and ZMA group, respectively. In these two groups, adverse effects during recovery time from anesthesia were not seen. As a result, the ZMA group had a faster recovery than the ZM group. Thus it was concluded that atipamezole could exert a useful reversal effect in cats anesthetized with medetomidine-tiletamine/zolazepam combination.

• Journal of Life Science
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• v.24 no.2
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• pp.173-180
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• 2014

Estrogen can promote or inhibit cellular proliferation depending on tissue cell types and physiological condition and acts through the signal transduction pathways mediated primarily by estrogen receptors. This study examined the effects of fulvestrant (Ful), a well-known antagonist for the estrogen receptor, on the action of $17{\beta}$-estradiol (E2) with respect to the proliferation and apoptosis of Chinese hamster ovarian (CHO) cells. We used different concentrations of E2, Ful, and E2 plus Ful during different treatment durations. Treatment with 15-40 ${\mu}M$ E2 significantly inhibited proliferation in a time-dependent manner, although it had no influence in concentrations up to 1 ${\mu}M$. Interestingly, Ful at 10-40 ${\mu}M$ also inhibited cellular proliferation in both a concentration- and time-dependent manner. In addition, Ful enhanced rather than decreased the inhibitory effect on cellular proliferation by E2 in combined treatment for 10 days. Thus, Ful does not appear to have an antagonistic effect on estrogen's anti-proliferative action in CHO cells. In TUNEL assays to confirm DNA fragmentation by E2 and/or Ful, CHO cells treated with 20 ${\mu}M$ E2 showed a TUNEL-positive reaction in most DAPI-stained nuclei, and cells treated with either 40 ${\mu}M$ Ful or 40 ${\mu}M$ Ful plus 20 ${\mu}M$ E2 also exhibited a TUNEL-positive reaction but at a lower rate compared to the E2-treated cells. These results indicate that Ful does not have an antagonistic effect on estrogen's anti-proliferative action in CHO cells, suggesting that the anti-proliferative and apoptosis-related mechanism(s) through DNA fragmentation by E2 and Ful may be mediated by different signal transduction pathways.

• Journal of Haehwa Medicine
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• v.4 no.2
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• pp.309-329
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• 1996

There are the Seven Effect of Drugs and unique processing methods in Chinese traditional medicine. The Seven Effects are single effrect(單行), additive effect(相加, 相須), synergic effect(上乘, 相使), antagonistic effect(相畏, 拮抗), inhibitory effect(相惡), neutralizing effect(相殺) and opposite effect(相反). We are interested in synergic effects of some drugs and components ; Addition of OLDENLANDIA DIFFUSA to Kilkyungtang combanation enhanced the cytotoxic activity of Kilkyungtang against A549 and B16-Fo eells by 20% and 50%, respectively. The Oldenlandia-added kilkyungtang also potentiated the cytotoxicities of mitomycine Cand 5-fluorouracil. ar-tunnerone. isolated from the root of Curcuma longa, potentiated the cytotoxic activity of sesquiphellandrene(isolated from the same root), aurapten(isolated from Aurantii semen)or cyclophosphamide by 10 times. The purpose of the processing(修治) of Chinese grugs is to remove unusable parts of plants and to eliminate toxicities as well as to produse new active components in drugs. On a occasion of study on the anthelmintic drugs against the chinese fluke(Clonorchis sinesis, (肝디스토마), we have observed that the processed mume fruit(鳥梅) possessed a very very potent clonorchicidal effect, while the methanol extract of the non-processed fruit inactive. The active component was isolated from the processed mume and identified as 5-hydroxymethylfurfuryl aldehyde. This substance dose not occur in the immature fruit and was found only in the processed one. Wehave heated the immature fruit in an oven at $90^{\circ}C$ for 52 hrs and found that the heated fruit eame clonorchidal. As demonstrated in these and other example cited in this presentation, the natural products chemistry is contributory to univeiling the drug effect ensued from the processing and the synergic effect of Oriental medical drug combinations, and to rationalization or modernization of the traditional medicine.

• Proceedings of the Korean Society of Plant Pathology Conference
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• 2003.10a
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• pp.98.1-98
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• 2003

Antagonistic effect of bacterial strains isolated from phylloplane of strawberry plants grown In greenhouse was tested on Botrytis cinerea Among the promising bacterial strains, Bacillus sp. S1-0210 showed highest inhibition of mycelial growth of B. cinerea and a broad spectrum of antifungal activities against many plant pathogenic fungi in vitro. Bacillus sp. S1-0210 was identified as Bacillus subtilis based on the analysis of 185 rDNA as well as its biochemical characteristics. Application of wettable powder formulation of B. subtiiis S1-0210 significantly reduced the incidence of gray mold on trawberry fruits during storage. Results showed that treatment of B. subtilis S1-0210 decreased the incidence of gray mold by 4.8％ whereas the incidence in control was 77.9％, indicating that the formulation of B. subtilis S1-0210 will be practically applied on strawberry fruits as a biocontrol agent of gray mold during storage.

• Preventive Nutrition and Food Science
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• v.2 no.4
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• pp.310-315
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• 1997

Wild propionibacteria isolated from different commercial swiss cheese samples were tested for antimicrobial activities. In initial screening, six of these Propionibacterium isolates showed antagonistic activity against 10 selected indicator organisms by the deferred method. In next, only two Propionibacterium strains JW6 and JW14 showed antibacterial activity in the cell-free supernatants by the modified well diffusion method. Propionibacterium strains JW6 and JW14 were finally identified as bacteriocin producers which exhibited a bactericidal effect against closely related species. The antimicrobial substances were proteins, since their activities were completely destroyed following several degradative enzyme treatments. The bacteriocins showed a narrow inhibitory spectrum of activity against two propionibacteria and two bacilli of strains tested in this study.

• Korean Journal of Environmental Biology
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• v.21 no.4
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• pp.321-327
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• 2003

Differences between the principles for the radiological protection of man and the environment are compared. The derived levels of exposure for man and biota recommended by the international agencies with dose rates for chronic radiation producing effects at different levels of biological organization were given in terms of the biological effects. Cytogenetic effects on plants after an exposure to ionizing radiation at low doses alone and in combination with other factors are discussed. A wide range of experimental data were analysed and the general conclusions were extracted to cover the topics such as non-linearity of dose response, synergistic and antagonistic effects of the combined exposure of different factors, radiation-induced genomic instability, and the phenomena of radioadaptation.

• Microbiology and Biotechnology Letters
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• v.1 no.2
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• pp.89-92
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• 1973

In the previous paper the biological characteristics and some reaction mechanisms of Astradix-P, yeaststatic substance, were reported. Especially yeaststatic activity of Astradix-P was anta-gonistically inhibited by alkaline amino acids, arginine, lysine and histidine, which were added as a nitrogen source in the yeast growing medium. In this paper the effects of alkaline nitrogen containing substance and several vitamins on the yeaststatic activity were investigated. The antagonistic action of alkaline nitrogen containing substance; adenine and vitamins; thiamine, riboflavin, pyridoxin, cobalamin, nicotinic acid, folic acid, biotin, p-aminobenzoic acid, inositol, and pantothenic acid to Astradix-P were not observed, thus evidencing that the yeaststatic activity of Astradix-P was not inhibited by a alkaline nitrogen containing substance and several vitamins.

• 한국생물공학회:학술대회논문집
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• 2002.04a
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• pp.386-389
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• 2002

Antagonistic Bacillus sp. #16 to phytopathogenic fungi were selected based on the growth rate, inhibition rate and surface tension reduction. Based on the 16S rRNA sequences, Bacillus sp. #16 is closely related to the B. subtilis DSM10. In the pot test, Bacillus sp. #16 show the most effective growth inhibition against damping-off disease of cucumber seeding.