• The Plant Pathology Journal
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• 제19권4호
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• pp.210-216
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• 2003

This study examined the existence of genetically diverse population of Cucumber mosaic virus (CMV), known as quasispecies, from lily, Nicotiana benthamiana and from purified virions. Based on the conserved sequences of CMV lily isolates in intergenic region (IR) on RNA3, the genetic variation of IR from three different sources was investigated by a specific restriction endonuclease hydrolysis of amplified reverse transcription-polymerase chain reaction (RT-PCR) products using virus-specific primers, and was compared with IR sequences. The IR nucleotide sequences of CMV lily isolates were highly conserved, however, quasispecies was detected from all three sources in low level, containing sub-populations of RNA3. These subpopulations of RNA3 were inoculated onto zucchini squash by in vitro transcripts from corresponding full-length cDNA clones together with Eny RNA1 and 2 transcripts. The systemic symptom of zucchini plants infected by these quasispecies was chlorotic spotting, which was milder than severe mosaic and stunt symptom caused by Eny-CMV. The severity of symptom was correlated with RNA accumulation of viruses. These results suggest that the genome of CMV lily isolates consists of quasispecies populations.

• 한국응용약물학회:학술대회논문집
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• 한국응용약물학회 2000년도 춘계학술대회
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• pp.6-7
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• 2000

Recently, free radicals such as active oxygen species, nitric oxide, etc are believed to be one of the key substances in physiological and pathological, toxicological phenomena, and oxidative damages, and all organism have defencing system against such as free radicals. Formation and extinction of free radicals may be regulated through bio-redox system, in which various enzymes and compounds should be involved in very complicated manner. Thus, direct and non-invasive measurement of in vivo free radical reactions with living animals must be essential to understand the role of free radicals in pathophysiological phenomena. Electron spin resonance spectroscopy (ESR) is very selective and sensitive technique to detect free radicals, but a conventional ESR spectrometer has large detect in application to living animals, since high frequent microwave is absorbed with water, resulting in generation of high fever in living body. In order to estimate in vivo free radical reactions in living whole animals, we develop in vivo ESR-CT technique using nitroxide radicals as spin probes. Nitroxide radicals and their reduced forms, hydroxylamines, are known to interact with various redox systems. We found that! ! the signal decay due to reduction of nitroxyl radicals is influenced by aging, inspired oxygen concentration, ischemia-referfusion injury, radiation, etc. In the present paper, I will introduce in vivo ESR technique and my laboratory recent results concerning non-invasive evaluation of free radical reactions in living mice.

• Journal of Ecology and Environment
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• 제38권2호
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• pp.271-279
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• 2015

After the reversion of Okinawa (Ryukyu Islands) to Japan in 1972, extensive urban and agricultural development resulted in a significant increase in sediment discharge to coastal waters. The release of sediment has caused the degradation of freshwater and coastal ecosystems and biodiversity. A consideration for catchment-to-reef continua, as well as agricultural (socioeconomic) factors is necessary to establish proper land-based management plans for the conservation of the island environment. We have set up a framework to integrate biophysics and socioeconomics: 1) setting a conservation target and threshold, 2) identifying the sources and processes, and 3) examining cost-effectiveness and management priorities. The framework may be applicable to other tropical and subtropical islands with similar characteristics.

• Preventive Nutrition and Food Science
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• 제5권4호
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• pp.225-229
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• 2000

The antioxidative and protective activities of kefir, low-fat dry milk (NFDM) extract and fractions on SFME cells in serum-free medium were investigated. Kefir and low-fat kefir and NFDM extract were made by solubilizing the freeze dried powder forms in deionized water, filtering through glass prefilter, 12 ㎛ and 2 ㎛ membrane, and demineraling with chelating resin. Kefir, low-fat kefir and NFDM extract were fractioned into dialyzate and retentate by dialysis with membrane tube having the molecular cut-off of 3,500 Dalton. An antioxidative activity was analyzed by the in vitro model system using a linoleic acid. In the case of kefir an antioxidative activity was detected only in the retentate of kefir extract. On the other hand NFDM showed an antioxidative activity in extract, demineralized extract, dialyzate and retentate. The retentate of kefir extract had the higher antioxidative activity than that of NFDM extract. Kefir showed the protective effect of SFME cells in serum-free medium in extract, demineralized extract and retentate, but low-fat kefir didn't. NFDM had the similar protective effect on SFME cells as extract, demineralized extract and retentate of kefir.

• 대한화학회지
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• 제15권4호
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• pp.177-181
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• 1971

Free radicals of lysozyme produced by $Ti-H_2O_2$ system were studied in aqueous solution at room temperature using ESR with a continuous flow-mixing. The spectra, each consisting of a doublet with 5.5 G splitting and a broad resonance covering 80 G splitting are closely similar in shape to that for solid irradiated in vacuum at $77^{\circ}K$ and observed at room temperature immediately on warming. The result is assumed to indicate that the secondary protein radical components formed within 0.01 second, dead time of the mixing chamber, and initiated by hydrogen atom abstraction at ${\alpha}$-carbon atom of peptide chain in liquid solution at room temperature are identical to those resulting from the initial formation of a mixture of positive holes and negative ions by ionization processes as well as radical fragments by the rupture of chemical bonds in the solid during similar time at the same temperature. A broad resonance is observed with considerable amplitude on the high field side of the doublet, which is quite dissimilar to the spectra of irradiated solid lysozyme. This resonance was tentatively attributed to the polypeptide free radical in which unpaired electrons are localized on side chain.

• Journal of Photoscience
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• 제4권2호
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• pp.35-40
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• 1997

The sensory transduction processes of blue light in guard cells have been suggested the involvement of Ca$^{2+}$/calmodulin-dependent myosin light chain kinase (MLCK) or MLCK-like proteins. The source of Ca$^{2+}$ required for the signal transduction process was investigated in guard cell protoplasts (GCPs). The GCPs showed the typical H$^+$ pumping activity by blue light (200 $\mu$mol m$^{-2}$ s$^{-1}$) and fusicoccin (10 $\mu$M) under background red light (600 $\mu$mol m$^{-2}$ s$^{-1}$). The blue light-dependent H$^+$ pumping was not significantly affected by the externally changed Ca$^{2+}$ concentrations. The addition of 1 mM Ca$^{2+}$ in the bathing medium ratherly inhibited the H$^+$ pumping. In contrast, the blue light-dependent H$^+$ pumping was inhibited by caffeine and 2,5-di-(tert-butyl)-1,4-benzohydroquinone (BHQ), inhibitor of C$^{2+}$-ATPase in endoplasmic reticulum (ER) without inhibiting the H $^+$ pump. The inhibition by caffeine and BHQ was fully reversible. The extent of inhibition by caffeine and BHQ was larger when they were added together than when added separately. The results suggest that Ca$^{2+}$ required for the blue light-dependent H$^+$ pumping may be released from the intracellular Ca$^{2+}$ stores, probably ER in guard cells.

• Toxicological Research
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• 제8권2호
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• pp.331-342
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• 1992

The chicken major histocompatibility complex (MHC), the B complex, is beginning to be analyzed at the DNA level. Inbred lines of chickens have been reported to possess 3~5 MHC class II genes. To further analyzed the molecular structure of the chicken MHC class II genes, cDNA clones coding for chicken MHC class II (B-L) ${\beta}$ chain molecules were isolated from chicken spleen and liver. Tissue-specific transcription of B-L ${\beta}$genes was studied by Northern blot analysis. A high level of expression was detected for spleen poly(A)$^+$ RNA whereas a faint signal was detected for liver poly(A)$^+$ RNA. Twenty-nine cDNA clones were isolated from the spleen and eight cDNA clones were isolated from the liver. Based on restriction maps, most clones could be clustered into one family of genes. Four cDNA clones were sequenced (S7, S10 and S19 from the spleen and L1, which was identical to S19, from the liver). Complete amino acid sequences of B-L ${\beta}$ chain molecules were predicated from the nucleotide sequences of the cDNA clones. Although both the nature and the location of the conserved residues were similar in chicken and mammalian sequences, some species-specific differences were found, suggesting that the structures of the B-L molecules are similar, but not identical to their mammalian counterparts.

• The Korean Journal of Physiology
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• 제28권1호
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• pp.99-103
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• 1994

Single neuronal activities were recorded in the cuneate nucleus of awake rats during rest and running behavior. Movement-induced changes in somatic sensory transmission were tested by generating post-stimulus time histograms of these neurons' responses to stimulation through eleetrodes chronically implanted under the skin of the forepaw, during control resting behavior and during two standardized speeds of locomotor movement: slow (1.0 steps/s), fast (2.0 steps/s). The magnitudes of firing during these responses were measured and normalized as percentage increases over background firing. The averaged evoked unit responses were facilitated by $+59.3{\pm}12.5%\;and\;+25.6{\pm}5.4%$ (SEM) as compared with resting behavior, during slow and fast movement respectively. This is to be compared with the movement-induced sensory suppressions observed previously in the ventrobasal thalamus $(-31.0%{\pm}1.9%)$ and in the primary somatosensory cortex $(-71.2%{\pm}3.8%)$ of slowly running rats. These results suggest that afferent somatosensory information may be uniquely modulated at each sensory relay, such that it may be facilitated at brainstem level and then subjected to suppression at higher somatosensory nuclei during movement.

• Bulletin of the Korean Chemical Society
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• 제31권1호
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• pp.59-63
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• 2010

Calculations are presented for the $\gamma$-aminobutyric acid-$(H_2O)_n$ (n = 0-5) clusters in both canonical and zwitterionic forms. We examine the effects of microsolvation on the structures and transformation between the canonical and zwitterionic forms. The canonical forms are predicted to be more stable for n = 0-4. With five microsolvating water molecules, the two forms of $\gamma$-aminobutyric acid become quasidegenerate, with the energies of zwitterionic forms slightly (by 1 - 3 kcal/mol) higher. The lowest energy zwitterionic conformer of $\gamma$-aminobutyric acid-$(H_2O)_5$ cluster is calculated to isomerize to canonical form through a barrier-less proton transfer process and is thus predicted to be kinetically unstable. Therefore, we predict that the canonical conformers of $\gamma$-aminobutyric acid should be observed predominantly in the gas phase at low temperature in presence of up to five water molecules.

• Bulletin of the Korean Chemical Society
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• 제29권5호
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• pp.1013-1017
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• 2008

Syndecan-3 is a cell-surface heparan sulfate proteoglycan, which performs a variety of functions during cell adhension process. It is also a coreceptor for growth factor, mediating cell-cell and cell-matrix interaction. Syndecan-3 contains a cytoplasmic domain potentially associated with the cytoskeleton. Syndecan-3 is specifically expressed in neuron cell and has related to neuron cell differentiation and development of actin filament in cell migration. Syndecans each have a unique, central, and variable (V) region in their cytoplasmic domains. And that region of syndecan-3 may modulate the interactions of the conserved C1 regions of the cytoplasmic domains by tyrosine phosphorylation. Cytoplasmic domain of syndecan-3 has been synthesized for NMR structural studies. The solution structure of syndecan-3 cytoplasmic domain has been determined by two-dimensional NMR spectroscopy and simulated-annealing calculation. The cytoplasmic domain of the syndecan proteins has a tendency to form a dimmer conformation with a central cavity, however, that of syndecan-3 demonstrated a monomer conformation with a flexible region near C-terminus. The structural information might add knowledge about the structure-function relationships among syndecan proteins.