• Journal of Microbiology and Biotechnology
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• v.17 no.1
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• pp.104-109
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• 2007

Lactic acid bacteria that accumulated ${\gamma}-aminobutyric$ acid (GABA) in culture medium were screened to identify strains with high GAB A-producing ability. One strain, MS, which was isolated from kimchi, showed the highest GABA-producing ability among the screened strains. MS was identified as Lactobacillus buchneri based on Gram-staining, metabolic characteristics, and 16S rDNA sequence determination, Optimum culture conditions for GABA production were determined: MRS broth containing 5% MSG, 1% NaCl, and 1% glucose, at an initial pH of 5.0, the incubation temperature at $30^{\circ}C$ for 36 h. Under these conditions, MS produced GABA at a concentration of 251 mM with a 94% GABA conversion rate. Moreover, culture extracts of Lb. buchneri MS partially or completely protected neuronal cells against neurotoxicantinduced cell death.

• Journal of Microbiology and Biotechnology
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• v.19 no.8
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• pp.787-791
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• 2009

In the course of screening for substances that inhibit etoposide (10 ${\mu}g$/ml)-induced apoptosis in human leukemia U937 cells, fungal strain F000120, which exhibits potent inhibitory activity, was selected. The active compound was purified from an ethyl acetate extract of the microorganism by Sep-pak $C_{18}$ column chromatography and HPLC, and was identified as heptelidic acid (koningic acid) by spectroscopic methods. This compound inhibited caspase-3 induction in U937 cells with an $IC_{50}$ value of 40 ${\mu}M$ after 8 h of etoposide treatment. Fluorescent dye staining with acridine orange and ethidium bromide showed that heptelidic acid inhibited apoptosis. Furthermore, it was found that DNA fragmentation and caspase-3 activation, the biological hallmarks of apoptosis, were inhibited by the compound in a dose-dependent manner, suggesting that heptelidic acid inhibits etoposide-induced apoptosis via downregulation of caspases.

• Tuberculosis and Respiratory Diseases
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• v.39 no.1
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• pp.1-6
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• 1992

The diagnosis of tuberculosis is usually established using staining and culturing techniques. Fluorescent stains have improved the sensitivity of direct microscopy. Improved culture media coupled with radiometric means of detecting early mycobacterial growth have shortened the time needed for cultural diagnosis. Rapid immunodiagnostic techniques based on the detection of mycobacterial antigen or of antibodies to theses antigens have not, however, come into widespread clinical use. The DNA or RNA hybridization tests with labeled specific probes which have been described so far are not sensitive enough to be used for clinical speicimens without prior culturing. The advent of the polymerase chain reaction (PCR) has opened new possibilities for diagnosis of microbial infections. This technique has already been applied to a number of microorganisms. In the field of mycobacteria the PCR has been used to identify and to detect DNAs extracted from various mycobacteria. However, despite the extraordinary enthusiasm surrounding this technique and the considerable investiment, PCR has not emerged from the developmental "trenches" in the passed several years. It may be a considerable lenth of time before clinical microbiology laboratories become PCR playgrounds because many details remain to be worked out.

• Toxicological Research
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• v.21 no.4
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• pp.285-290
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• 2005

We demonstrate that radicicol, a macrocyclic antifungal antibiotic originally isolated from Monosporium bonorden, inhibits LPS-induced expression of iNOS gene in RAW 264.7 cells. Treatment of peritoneal macrophages and RAW 264.7 cells with radicicol inhibited LPS-stimulated nitric oxide production in a dose-related manner. Immunohistochemical staining of iNOS and RTPCR analysis showed that the decrease of NO was due to the inhibition of iNOS gene expression in RAW 264.7 cells. Immunostaining of p65, EMSA, and reporter gene assay showed that radicicol inhibited $NF-\kappa/Rel$ nuclear translocation. DNA binding, and transcriptional activation, respectively. Collectively, these series of experiments indicate that radicicol inhibits iNOS gene expression by blocking $NF-\kappa/Rel$ nuclear translocation. Due to the critical role that NO release plays in mediating inflammatory responses, the inhibitory effects of radicicol on iNOS suggest that radicicol may represent a useful anti-inflammatory agent.

• Journal of Plant Biology
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• v.38 no.1
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• pp.33-38
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• 1995

Hydroxyurea (HU), a DNA synthesis inhibitor, was tested as synchronizing agent in root-tip meristem of Allium wakegi. Roots were treated with 2.5mM HU for 14 h to accumulate meristem root-tip cells at the G1/S interface. After release from HU block, the cells re-entered the cell cycle with a high degree of synchrony. Synchronized mitotic frequency of A. wakegi was 22.7%, which was about 3.9 times as high as that of the control. The highest metaphase index(23.0%) was obtained when, 6 h after release from the HU block, the roots were treated with 0.05% colchicine for 2 h. Modifying various Giemsa staining protocols defined for animals and a few plant species, G-bands were visualized at prometaphase and metaphase chromosomes of A. wakegi. The higher degree of chromosome condensation, the less differential bands could be resolved. This is the first demonstration introduced partial mitotic synchronization into G-banding in plant.

• BMB Reports
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• v.38 no.3
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• pp.314-319
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• 2005

Adenosine, as a ubiquitous metabolite, mediates many physiological functions via activation of plasma membrane receptors. Mechanisms of most of its physiological roles have been studied extensively, but research on adenosine-induced apoptosis (AIA) has only started recently. In this study we demonstrate that adenosine dose-dependently triggered apoptosis of cultured baby hamster kidney (BHK) cells. Adenosine-induced apoptotic cell death was characterized by DNA laddering, changes in nuclear chromatin morphology and phosphatidylserine staining. Apoptosis was also quantified by flow cytometry. Results suggest the involvement of adenosine $A_1$ and $A_3$ receptors as well as equilibrative nucleoside transporters in apoptosis induced by adenosine. These results indicate a receptor-transporter co-signaling mechanism in AIA in BHK cells. The involvement of $A_1$ and $A_3$ receptors also implies a possible apoptotic pathway mediated by G protein-coupled receptors.

• Journal of Marine Bioscience and Biotechnology
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• v.12 no.2
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• pp.123-130
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• 2020

Cancer is an unfavorable human disease, and the treatment commonly have side effects and can be ineffective. Since exploration and development of cancer treatment drugs is particularly demanding, this study aimed to investigate the anticancer activities of Polysiponia morrowii extract s (PME) on CT-26 and HeLa cells. The results showed that PME inhibited cell proliferation in a dose-dependent manner, with IC50 values of 41.04% in CT-26 and 48.51% in HeLa cell cultures. Moreover, cytological observation using Hoechst 33342 staining assay showed typical apoptotic morphology in both cancer cells, and production of sub-G1 DNA was induced by PME treatment in a dose-dependent manner, with 34.41% in CT-26 and 46.01% in HeLa cell cultures. These findings suggest that PME may have potential preventive effects or medicinal value in the treatment of colorectal and cervical cancers.

• Tuberculosis and Respiratory Diseases
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• v.43 no.1
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• pp.30-37
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• 1996

Background: The extraction methods of DNA from clinical samples are the major obstacle to use the PCR(polymerase Chain Reaction) in routine labortary for early detection of M. tuberculosis. We tried to improve the extraction method of DNA from sputum for establishment of the PCR in routine labortary by reducing the possibility of cross contamination and performing it easily and safely. Methods: We used the $InstaGene^{TM}$ DNA extraction kit(BioRad Co.) using Chelex 100 ion exchange resin for preparation of DNA. We compared InstaGene method in 100 cases of sputum from proteinase K method which is known as the most commonly used method for DNA purification(Experiment 1). And we compared InstaGene method in 98 cases of sputum from Microwave method developed by a company in Korea(Experiment 2). In experiment 1,245bps of IS6110 were amplified and then 188bps were amplified by nested PCR. In experiment 2,536bps in primary PCR and 276bps in nested PCR were amplified and analysed by agarose gel electrophoresis and EtBr staining. Results: When we chose AFB smear, culture, or AFB smear and culture as a standard test, PCR had low specificity and positive predictive value in both experiments. The InstaGene method has higher value in sensitivity and negative predictive value significantly than proteinase K method. The InstaGene method and the Microwave methods were similar in sensitivity, specificity, positive predictive value and negative predictive value. Conclusion: Even though both methods had lower possibility of cross contamination, shorter time requirement, simplicity, and economic advantages than Proteinase K method, the InstaGene method was a little simpler than the Microwave method. Therefore, in terms of usefulness in clinical application, the Instagene method seems to be the most useful method in DNA extraction for detection of M. tuberculosis using PCR. The reliability of this method will be clarified by further studies with enough clinical samples.

• Journal of Microbiology and Biotechnology
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• v.27 no.3
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• pp.535-541
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• 2017

Two Gram-staining-negative, red-pinkish, coccus-shaped, non-motile, and aerobic bacterial strains, designated $Ant21^T$ and Ant22, were isolated from the Antarctic coastal sea water. Strains $Ant21^T$ and Ant22 showed UVC and gamma radiation resistance. Phylogenetic analyses based on 16S rRNA gene sequences determined that these strains belong to the genus Deinococcus. Through the analyses of the 16S rRNA gene sequences, strains $Ant21^T$ and Ant22 were found to have 97.7% and 97.8% similarity to Deinococcus marmoris DSM $12784^T$ and 97.0% and 97.2% similarity to Deinococcus saxicola AA-$1444^T$, respectively. The sequence similarity with the type strains of other Deinococcus species was less than 96.9% for both strains. Strains $Ant21^T$ and Ant22 shared relatively high 16S rRNA gene sequence similarity (99.3%) and had a closely related DNA reassociation value of $84{\pm}0.5%$. Meanwhile, they showed a low level of DNA-DNA hybridization (<30%) with other closely related species of the genus Deinococcus. The two strains also showed typical chemotaxonomic features for the genus Deinococcus, in terms of the major polar lipid (phosphoglycolipid) and the major fatty acids ($C_{16:0}$, $C_{16:1}$ ${\omega}6c/{\omega}7c$, $iso-C_{17:0}$, and $iso-C_{15:0}$). They grew at temperatures between $4^{\circ}C$ and $30^{\circ}C$ and at pH values of 6.0-8.0. Based on the physiological characteristics, the 16S rRNA gene sequence analysis results, and the low DNA-DNA reassociation level with Deionococcus marmoris, strains $Ant21^T$ ($=KEMB\;9004-167^T$ $=JCM\;31436^T$) and Ant22 (KEMB 9004-168 =JCM 31437) represent novel species belonging to the genus Deinococcus, for which the name Deinococcus rubrus is proposed.

• Korean Journal of Head & Neck Oncology
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• v.12 no.2
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• pp.169-176
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• 1996

Tuberculous cervical lymphadenitis is still an important cause of neck mass in Korea. Tuberculosis is an important differential diagnosis in patients of cervical lymphadenopathy. Rapid and sensitive test for the diagnosis of tuberculosis is essential for the approapiate treatment. Up to now, conventional diagnostic methods for M. tuberculosis were acid-fast bacilli(AFB) stain and culture of M. tuberculosis. The direct microscopic examination of AFB by Ziehl-Neelsen stain is rapid, but often negative. The culture for M. tuberculosis is time-consuming, taking 4 to 8 weeks. Recently various methods to detect Mycobacterial DNA, including PCR and restriction fragment length polymorphism(RFLP) analysis have been reported. Here we represent a simple method for the confirmation of M. tuberculosis and exclusion of the other Mycobacterial species by RFLP analysis and silver staining of polyacrylamide gel electrophoresis after nested PCR for a repetitive DNA sequence(IS986) specific for M. tuberculosis from fresh or paraffin-embedded biopsy specimens. This result leads us to conclude that this method is simple, rapid and possibly applicable to confirm M. tuberculosis and rule out the other Mycobacteria species from the clinical specimens in the clinical laboratories.