• The Korean Journal of Mycology
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• v.13 no.3
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• pp.169-177
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• 1985

The studies were carried out to obtain the basic data for maximizing the protoplast yields from the mycelia of P. ostreatus and P. sajor-caju. Some factors affecting the regeneration of the protoplast of both species and the productivity of their reversion were also examined. The maximum yields of protoplasts were obtained from four days cultured mycelia of both species on cellophan membrane placed on the surface of PSA or MCM media in a petri dish. The optimal concentration of lytic enzyme Novozym 234 for protoplast releasing was 5 mg per ml of 0.5 M phosphate buffer solution with 0.6 M sucrose or 0.6 M $MgSO_4$ at pH 6.0. The greatest number of protoplasts was released 3 hours after incubation of the mycelia of P. ostreatus and after 4 hours for the P. sajor-caju in the lytic enzyme solution. Among the osmotic stabilizer solutions tested 0.6 M sucrose and 0.6 M KCl showed the best regeneration rates of the protoplasts of both species. When 0.75 % agar solution was over-layed on the regeneration media immediately after inoculation of the protoplast the regeneration rates were greatly enhanced. The ampicillin added to the agar solution prevented bacteria from infection. The reverted isolates produced the sporophores and basidial spores just like their parents without any mutations when they were cultivated in a broad mouth bottle with sawdust substrates.

• Korean Journal of Pharmacognosy
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• v.47 no.2
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• pp.122-127
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• 2016

Methicillin-Resistant Staphylococcus aureus(MRSA) is a multidrug-resistant(MDR) strain. (+)-Usnic acid(UA) is uniquely found in lichens, and is especially abundant in genera such as Usnea and Cladonia. UA has antimicrobial activity against human and plant pathogens. Therefore, UA may be a good antibacterial drug candidate for clinical development. In search of a natural products capable of inhibiting this multidrug-resistant bacteria, we have investigated the antimicrobial activity of UA against 17 different strains of the bacterium. In this study, the effects of a combination of UA and permeable agents against MRSA were investigated. For the measurement of cell wall permeability, UA with concentration of Ethylenediaminetetraacetic acid(EDTA) was used. In the other hand, Sodium azide($NaN_3$) was used as inhibitors of ATPase. Against the 17 strains, the minimum inhibitory concentrations(MICs) of UA were in the range of $7.81-31.25{\mu}g/ml$. EDTA or $NaN_3$ cooperation against MRSA showed synergistic activity on cell wall. UA and in combination with EDTA and $NaN_3$ could lead to the development of new combination antibiotics against MRSA infection.

• Journal of the korean veterinary medical association
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• v.25 no.10
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• pp.595-606
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• 1989

항원제시세포(APC)와 보조T세포 간의 협력작용에 의하여 활성화된 작동세포(NK세포, CTL, K세포, 대식세포, 과립구 등)의 종양세포, 이식장기 및 세포내기생세균에 감염된 각종 세포에 대한 세포독성작용은 생체방어를 위한 중요한 세포성면역기전이다. 지난 몇 년간 세포성면역기전에 관한 많은 연구에도 불구하고 T림파구매개성 세포독성작용의 면역생물학적기전은 확실히 밝혀있지 않다. 지금까지 알려진 중요한 연구내용을 요약하면 다음과 같다. 1. 세포독성작용을 나타내는 작동세포로는 NK세포, CTL, K세포, 대식세포/단핵구 및 과립구가 있다. 2. T세포의 세포표면항원분자군(CD)으로는 $CD_{2},\;CD_{3},\;CD_{4}[Ly_{3}T_{4}],\;CD_{5}[=Ly_{1}],\;CD_{7},\;CD_{8}[Ly_{2,3}]$가 있으며 $CD_{4}$는 보조Ttpvhdml 특이마커이고 $CD_{8}$는 세포독성 T세포 및 억압T세포의 특이마커이다. 주요 T세포수용체(TCR)는 $CD_{4}$ 또는 $CD_{8}$ 분자와 가까이 연합된 이향체($TCR-{\alpha}{\beta}/TCR-{\gamma}{\delta}$이며 보조 T세포 $CD_{4}$(마우스 $L_{3}T_{4}$)는 수용체와 연합되어 있는반면 억압 T세포 $CD_{8}(Ly+_{2,3})$는 항원수용체와 연합되어 있다. 3. T세포는 Ti-$CD_{3}$(항원/MHC) 복합체를 통한 '항원가교'에 의한 자극(항원인식)과 $CD_{2}$를 통한 비특이경로에 의하여 활성화(분화증식)된다. 비특이경로를 통한 활성경로에서 T세포($CD_{4}$ 및 $CD_{8}$)가 활성화되기 위하여는 보조T세포가 생산하는 IL-2을 요구하며 IL-2의 자극으로 분화증식된 $CD_{8}$는 세포독성능을 나타내지만 $CD_{4}^{+}$는 여전히 세포독성능을 나타내지 못한다. 4. 보조T세포는 class II MHC분자와 연합된 항원을 식별하는 반면 세포독성T세포는 class I MHC 분자와 연합된 항원을 식별한다. 5. 림파구 매개성 세포독성은 접촉(conjugati-on), 탈분극(depolarization), 용해계획(progra-mming), 용해(lysis) 및 재순환(recycling)의 단계를 거쳐 진행된다. 6. 표적세포살해매체로는 perforin / PFP / cy-tolysin, lymphopores, lymphotoxins, protone, cytolytic enzymes가 알려졌으며 세포독성작용은 이들 이외에도 여러 가지 매체를 통한 복합작용으로 추정된다. 7. CTL 매개성 표적세포의 주요 대사변화는 actomyocin ATPase의 증가, phosphocreatine과 ATPase의 소모, ATP 의존성 $Na^{+}/K^{+}$ 펌프작용의 중지, ATP 의존성 $Ca^{2+}$ 유출감소 및 세포내 축적이 관찰된다. 8. $Ca^{2+}$의 축적으로 세포막 교질 침투손상을 주어 수분의 유입을 증가시킴으로써 수포형성, 핵붕괴, 사립체팽화 및 정상세포 구조상실(Zeiosis)이 있다. 결론적으로 CTL 매개성 세포독성작용은 PFP, LT, TNF, 유사 TNF / LT 및 기타 매체를 통한 복합작용이며 세포살해기전은 지속적 대사소모와 정형적 세포구조(핵 및 세포질)의 파괴에 의한 것이다.

• Proceedings of the Korea Environmental Mutagen Society Conference
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• 2002.11a
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• pp.80-88
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• 2002

Recent studies demonstrate that collagen IV selectively pro-motes the repair of physiological processes in sublethally injured renal proximal tubular ceils (RPTC). We sought to further define the mechanisms of cell repair by measuring the effects of toxicant injury and stimulation of repair by L-ascorbic acid-2-phosphate (AscP), exogenous collagen IV, or function-stimulating integrin antibodies on the expression and subcellular localization of collagen-binding integrins (CBI) in RPTC. Expression of CBI subunits ${\alpha}_1$, ${\alpha}_2$, and ${\beta}_1$ in RPTC was not altered on day 1 after sublethal injury by S-(1,2-dichlorovinyl)-L-cysteine (DCVC). On day 6, expression of ${\alpha}_1$ and ${\beta}_1$ subunits remained unchanged, whereas a 2.2-fold increase in ${\alpha}_2$ expression was evident in injured RPTC. CBI localization in control RPTC was limited exclusively to the basal membrane. On day 1 after injury, RPTC exhibited a marked inhibition of active $Na^+$ transport and a loss of cell polarity characterized by a decrease in basal CBI localization and the appearance of CBI on the apical membrane. On day 6 after injury, RPTC still exhibited marked inhibition of active $Na^+$ transport and localization of CBI to the apical membrane. However, DCVC-injured RPTC cultured in pharmacological concentrations of AscP (500 ${\mu}$M)or exogenous collagen IV (50 ${\mu}$g/ml) exhibited an increase inactive $Na^+$ transport, relocalization of CBI to the basal membrane, and the disappearance of CBI from the apical membrane on day 6. Function-stimulating antibodies to CBI ${\beta}_1$ did not promote basal relocalization of CBI despite stimulating the repair of $Na^+$/$K^+$-ATPase activity on day 6 after injury. These data demonstrate that DCVC disrupts integrin localization and that physiological repair stimulated by AscP or collagen IV is associated with the basal relocalization of CBI in DCVC-injured RPTC. These data also suggest that CBI-mediated repair of physiological functions may occur independently of integrin relocalization.

• The Korean Journal of Physiology and Pharmacology
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• v.12 no.4
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• pp.155-164
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• 2008

Resveratrol has been known to possess various potent cardiovascular effects in animal, but there is little information on its functional effect on the secretion of catecholamines (CA) from the perfused model of the adrenal medulla. Therefore, the aim of the present study was to determine the effect of resveratrol on the CA secretion from the isolated perfused model of the normotensive rat adrenal gland, and to elucidate its mechanism of action. Resveratrol (10${\sim}100{\mu}$M) during perfusion into an adrenal vein for 90 min inhibited the CA secretory responses evoked by ACh (5.32 mM), high $K^+$ (a direct membrane-depolarizer, 56 mM), DMPP (a selective neuronal nicotinic $N_n$ receptor agonist, 100${\mu}$M) and McN-A-343 (a selective muscarinic $M_1$ receptor agonist, 100${\mu}$M) in both a time- and dose- dependent fashion. Also, in the presence of resveratrol (30${\mu}$M), the secretory responses of CA evoked by veratridine 8644 (an activator of voltage-dependent$Na^+$ channels, 100${\mu}$M), Bay-K-8644 (a L-type dihydropyridine $Ca^{2+}$ channel activator, 10${\mu}$M), and cyc1opiazonic acid (a cytoplasmic $Ca^{2+}$-ATPase inhibitor, 10${\mu}$M) were significantly reduced. In the simultaneous presence of resveratrol (30${\mu}$M) and L-NAME (an inhibitor of NO synthase, 30${\mu}$M), the CA secretory evoked by ACh, high $K^+$, DMPP, McN-A-343, Bay-K-8644 and cyc1opiazonic acid were recovered to a considerable extent of the corresponding control secretion compared with the inhibitory effect of resveratrol alone. Interestingly, the amount of nitric oxide (NO) released from the adrenal medulla was greatly increased in comparison to its basal release. Taken together, these experimental results demonstrate that resveratrol can inhibit the CA secretory responses evoked by stimulation of cholinergic nicotinic receptors, as well as by direct membrane-depolarization in the isolated perfused model of the rat adrenal gland. It seems that this inhibitory effect of resveratrol is exerted by inhibiting an influx of both ions through $Na^+$ and $Ca^{2+}$ channels into the adrenomedullary cells as well as by blocking the release of $Ca^{2+}$ from the cytoplasmic calcium store, which are mediated at least partly by the increased NO production due to the activation of NO synthase.

• The Korean Journal of Physiology and Pharmacology
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• v.12 no.3
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• pp.101-109
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• 2008

The aim of the present study was to examine the effects of ketamine, a dissociative anesthetics, on secretion of catecholamines (CA) secretion evoked by cholinergic stimulation from the perfused model of the isolated rat adrenal gland, and to establish its mechanism of action, and to compare ketamine effect with that of thiopental sodium, which is one of intravenous barbiturate anesthetics. Ketamine ($30{\sim}300{\mu}M$), perfused into an adrenal vein for 60 min, dose- and time-dependently inhibited the CA secretory responses evoked by ACh (5.32 mM), high $K^+$ (a direct membrane-depolarizer, 56 mM), DMPP (a selective neuronal nicotinic NN receptor agonist, $100{\mu}M$) and McN-A-343 (a selective muscarinic M1 receptor agonist, $100{\mu}M$). Also, in the presence of ketamine ($100{\mu}M$), the CA secretory responses evoked by veratridine (a voltage-dependent $Na^+$ channel activator, $100{\mu}M$), Bay-K-8644 (an L-type dihydropyridine $Ca^{2+}$ channel activator, $10{\mu}M$), and cyclopiazonic acid (a cytoplasmic $Ca^{2+}$-ATPase inhibitor, $10{\mu}M$) were significantly reduced, respectively. Interestingly, thiopental sodium ($100{\mu}M$) also caused the inhibitory effects on the CA secretory responses evoked by ACh, high $K^+$, DMPP, McN-A-343, veratridine, Bay-K-8644, and cyclopiazonic acid. Collectively, these experimental results demonstrate that ketamine inhibits the CA secretion evoked by stimulation of cholinergic (both nicotinic and muscarinic) receptors and the membrane depolarization from the isolated perfused rat adrenal gland. It seems likely that the inhibitory effect of ketamine is mediated by blocking the influx of both $Ca^{2+}$ and $Na^+$ through voltage-dependent $Ca^{2+}$ and $Na^+$ channels into the rat adrenal medullary chromaffin cells as well as by inhibiting $Ca^{2+}$ release from the cytoplasmic calcium store, which are relevant to the blockade of cholinergic receptors. It is also thought that, on the basis of concentrations, ketamine causes similar inhibitory effect with thiopental in the CA secretion from the perfused rat adrenal medulla.

• Applied Biological Chemistry
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• v.20 no.2
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• pp.221-227
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• 1977

Contents of proline and chloride in halophytes were $80-1700\;{\mu}g/gfw$ and 0.13-0.45 mM/gfw respectively. The content of proline was inversely proportional to that of chloride. Rhizomes of Phargmites communis Trin, a halophyte, were grown in non-saline medium and then taken to saline treatment for one or two weeks. Growth of P. communis was inhibited when salinized with 0.25M NaCl. Total nitrogen decreased and alcohol soluble nitrogen and proline increased when growth was retarded. The quantity of Fraction 1 protein decreased at 0.25M NaCl treatment. The accumulation of proline at high concentration in P. communis suggested that it might play a role in osmotic adjustment.

• Bulletin of the Korean Chemical Society
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• v.32 no.6
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• pp.1925-1930
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• 2011

Psychrophilic bacteria have acquired cold-resistance in order to protect themselves against freezing temperatures, which would otherwise be lethal. DnaK/DnaJ/GrpE systems are molecular chaperones which facilitate proper folding of newly synthesized proteins. Efficient folding processes are of great importance especially in a cold environment, such as the Arctic. In order to understand the protection mechanisms of psychrophilic bacteria against cold temperatures, we have explored a genome of KOPRI22215, tentatively identified as Psychromonas arctica, whose genome sequence has not yet been discovered. With an aim of searching for a coding gene of DnaK from KOPRI22215, we have applied a series of polymerase chain reactions (PCR) with homologous primers designed from other Psychromonas species and LA PCR in vitro cloning. 1917 bp complete coding sequence of dnaK from KOPRI22215 was identified including upstream promoter sites. Recombinant plasmids to overexpress PaDnaK along with EcDnaK (DnaK of E. coli) were then constructed in pAED4 vector and the pET-based system to induce PaDnaK expression by IPTG. Characterization assays of expressed PaDnaK were carried out by measuring survival rates upon 4 day incubation at 4 $^{\circ}C$: a refolding assay as molecular chaperone, and ATPase assay for functional activity. Taking account of all the data together, we conclude that PaDnaK was identified, successfully expressed, and found to be more efficient in providing cold-resistance for bacterial cells.

• Nutrition Research and Practice
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• v.8 no.1
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• pp.46-53
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• 2014

Inorganic arsenic (iAs) is a toxic metalloid found ubiquitously in the environment. In humans, exposure to iAs can result in toxicity and cause toxicological manifestations. Arsenic trioxide ($As_2O_3$) has been used in the treatment for acute promyelocytic leukemia. The kidney is the critical target organ of trivalent inorganic As ($iAs^{III}$) toxicity. We examine if oral administration of astaxanthin (AST) has protective effects on nephrotoxicity and oxidative stress induced by $As_2O_3$ exposure (via intraperitoneal injection) in rats. Markers of renal function, histopathological changes, $Na^+-K^+$ ATPase, sulfydryl, oxidative stress, and As accumulation in kidneys were evaluated as indicators of $As_2O_3$ exposure. AST showed a significant protective effect against $As_2O_3$-induced nephrotoxicity. These results suggest that the mechanisms of action, by which AST reduces nephrotoxicity, may include antioxidant protection against oxidative injury and reduction of As accumulation. These findings might be of therapeutic benefit in humans or animals suffering from exposure to $iAs^{III}$ from natural sources or cancer therapy.

• Biomedical Science Letters
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• v.9 no.3
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• pp.159-165
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• 2003

Ankyrins are a ubiquitously expressed family of intracellular adaptor proteins involved in targeting diverse proteins to specialized membrane domains in both the plasma membrane and the endoplasmic reticulum. Recently, the studies with C-terminus of ankyrins have identified that ankyrin-B is capable of interacting with Hsp40 and sAnkl is capable of interacting with obscurin and titin, but the function of C-terminal domain of ankyrin-G remains unknown. To identify proteins interacting C-terminus of ankyrin-G, we used the C-terminus of ankyrin-G as a bait for a yeast two-hybrid screen of brain cDNA library. Approximately 1.33$\times$l0$^6$ transformants were screened, of which 13 positive clones were obtained as determined by activation of HIS3, ADE2 and MELl reporter genes. Sequence analyses of these 13 plasmids revealed that cDNA inserts of 13 colonies showed highly homologous to 11 genes, including 5 known (i.e., Na$^+$/K$^+$ ATPase $\beta$1, SERBPl, UTF2, cytochrome C oxidase and collagen IV $\alpha$2) and 6 unknown genes. The evaluation of the proteins that emerge from these experiments provides a rational approach to investigate the those proteins significant in interaction with ankyrin-G.