• Journal of the Korean Society of Food Science and Nutrition
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• v.37 no.5
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• pp.612-617
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• 2008

Tetrodotoxin (TTX) analogues were first determined from the liver extracts of puffer fish, Takifugu niphobles, by LC/MS with Hydrophilic Interaction Liquid Chromatography (HILIC). In total, 7 TTX analogues were detected within 20 minutes as follows; 5,6,11-trideoxyTTX (34.0%, 1,029.6 nmol/g), 6,11-dideoxyTTX (29.3%, 887.6 nmol/g), TTX (22.1%, 667.8 nmol/g), 4,9-anhydro-TTX (11.2%, 339.3 nmol/g), 11-deoxyTTX＋5-deoxyTTX (2.6%, 78.6 nmol/g), and 4-epiTTX (0.8%, 23.6 nmol/g). Mouse toxicity of diluted liver extracts showed the highest toxicity at pH 3 (8.7 MU/mL) and decreased, as increasing pH, to 1.4 MU/mL at pH 10. At acidic (pH 5) and neutral conditions (pH 7), mouse toxicity of liver extracts (79 MU/mL) decreased slowly, as increasing temperature from $80^{\circ}C$ to $115^{\circ}C$, and time until 1 hour; in contrast, at the akaline condition (pH 9), the toxicity decreased rapidly to the more than half within 10 minutes. Individual toxicity of the fillet of T. niphobles were between $43.2{\sim}106.7$ MU, and $64{\sim}78%$ of its toxicity was eluted to soup when boiled with 3 volumes of water during 10 minutes.

• ALGAE
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• v.17 no.3
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• pp.171-185
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• 2002

The standing crop of genus Microcystis, microcystin concentrations and environmental factors were monitored at stations of the lower reaches of the Nakdong River in 1998 and 1999 during the periods of its occurrence. The Microcystis were observed from May to Octorber, and the cell density was highest at Station Seonam up to 250,000 cells${\cdot}ml^{-1}$ forming scum over the water surface. There were signigicant relationships between the standing crop of Microcystis and nitrate nitrogen, total phosphorus concentrations and Ph. Presumably these parameters were important in the succession to Microcystis dominated phytoplankton community in the summer period in the river. However, Ammonium nitrogen, phosphate phosphorus concentrations and N/P ratio were not critical factors. The Microcystis bloom was notable above $25^{\circ}C$ of surface water temperature. Microcystins were detected from May to November in the algal materials from the river. The 84.2% of algal materials with Microcystis exhibited the microcystin with the maximum of 1711.8 ${\mu}g{\cdot}g^{-1}$ dw. The microcystin concentrations in the algal materials were significantly related to the stading crop of Microcystis, which was the primary determinant factor in the toxin levle of algal materials. The concentrations were also significantly related to pH of the water column in the positive pattern.

• Microbiology and Biotechnology Letters
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• v.29 no.3
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• pp.169-175
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• 2001

This study was conducted to investigate the effects of bifidobacteria on the growth and Caco-2 cell-adherence of Escherichia coli O157:H7 .Dur-ing momo-culture of E. coli O157:H7 and mixed culture with Bifidobacterium infantis K9, pH viable cell count, and ammonia concentration were measured Co-cultivation of E. coli O157:H7 with bifidobacteria. producing acidic metabolites rapidly decreased the viable cell count of E. coli O157:H7 In addition rapid decrease of ammo- nia concentration was observed during mixed culture after 8 hrs incubation compared to single culture of E. coli O157:H7 Therefore it is likely that bifidobacteria assimilate ammonia produced by E. coli O157:H7 P4 B, infantis K9 showed quite similar adherence on the Caco-2 cells in either case. On the other hand adherence of E. coli O157:H7 decreased from 2.6% to 1.86% when B infantis K9 was adhered to Caco-2 cell 2 hrs prior to the application of E. coli O157:H7 In conclusion in adherence of E coli O157:H7 to Caco -2 cell was inhibited by competition of its binding to the adherence site with bifidobacteria. In addition inhibitory effects of bifidobacteria on E coli O157:H7 appeared to be much higher with increae of the number of bifidobacteria and its ability of adherence to Caco-2 cells.

• Applied Biological Chemistry
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• v.19 no.4
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• pp.189-201
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• 1976

In an effort to develop a microbial in secticide, B. thdringiensis var. thuringiensis was cultured in the medium composed of cocoon-cooked water from a filature. The results obtained are summarized as followss : (1) Bacillus thuringiensis is a bacterium producing a ${\delta}-endotoxin$ especially toxic to lepidopterous insects and a thermostable exotoxin harmful to dipterous insects. (2) With a view to utilizing the cocoon-cooked water discarded from the filature, as a nutrient source in the B. thuingiensis culture, it was analyzed to contain large amounts of various minerals and protein (7.5 mg/ml) believed to be extracted from the pupae. (3) A large amount of the ${\delta}-endotoxin$ can be obtained most cheeply by using cocoon-cooked water instead of distilled water in preparing GYS and citrate salts media. (4) The largest amount of a mixture of the vegetative cells, spores, and crystals was obtained by addition of 8 gr/l of glucose to the GYS medium. (5) The growth of the bacterium was far better, when leucine, isoleucine, and valine were added all together to the citrate salts medium to the concentration of $1.25{\times}10^{-3}M$. (6) The best growth was observed by addition of Na-glutamate to the citrate salts medium to the concentration of $2.5{\times}10^{-3}M$. (7) The optimal culture time ranged from 9 to 15 days. (8) The highest mortality was shown in Pieris rapae Linne with a pH of the total body extract of 8.4, whereas Dendrolimus spectabilis Butler and Bombyx mori Linne with lower pH's were less susceptible to the ${\delta}-endotoxin$. (9) The presence of the thermo stable exotoxin was confirmed by the fact that the supernatant of the culture was very toxic to the Drosophila melanogaster tested.

• The Korean Journal of Pharmacology
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• v.31 no.3
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• pp.355-363
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• 1995

It has been well known that the intracellular calcium concentration $([Ca^{2+}]_i)$ in living cell is very sensitive to live or to survive, but the transmembrane system of calcium ion, especially mechanism of calcium ion movement in unexcitable state has been little elucidated. Though many proposed theories for calcium ion transport have been reported, it is still unclear that how could the sustained maintenance in cytosolic calcium level be done in cell. Since one of possible mechanisms of calcium transport may be related to the acetylcholine receptor-linked calcium channel, author performed experiment to elucidate this mechanism of calcium influx related to cholinergic receptor in ml muscarinic receptor-transfected RBL-2H3 cell-line. 1) The effects of carbachol both on calcium ion influx and on the secretion of hexosaminidase were respectively observed in the manner of time-related or concentration-dependent pattern in this model. 2) The effects of several metal cations on calcium transport were shown in carbachol-induced cell-line. 3) Atropine was administered to examine the relationship between cholinergic receptor and calcium ion influx in this model. 4) PMA (Phorbol 12-myristate 13-acetate) or PTx (Pertussis toxin) was respectively administered to examine the secondary mediator which involved pathway of calcium ion movement in carbachol-induced cell-line. The results of this experiments were as follows; 1) Carbachol significantly stimulated both the calcium influx and the secretion of hexosaminidase in the manner of the concentration-dependent pattern. 2) Atropine potently blocked the effects of carbachol in concentration-response manner. 3) Administered metal cations inhibited the calcium influx in carbachol-stimulated this model to the concentration-related pattern. 4) PMA did not inhibit carbachol-induced secretion of hexosaminidase, but blocked the calcium influx in this cell-line. 5) The suppression of carbachol-induced hexosaminidase secretion was shown in PTx-treated cell -line.

• Annals of Clinical Neurophysiology
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• v.1 no.2
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• pp.126-146
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• 1999

In clinical neurology various different electrophysiological tests are widely used to demonstrate the unsuspected malfunctioning in the nervous system and to monitor over time the clinical status of patients. In addition clinical neurologists and neurosurgeons take advantage of the intraoperative monitorings to increase the quality of neurosurgical operations in the posterior fossa, in the spinal cord, or in visual pathways. In the field of movement disorders, elecrophysiolgical tests provide neurologists with making accurate differential diagnoses with useful therapeutic stratergies as well as with investigating the pathophysiological machanisms. By using the electromyographic tests it could be possible for us to evaluate the types of blephalospasm, the extent of hemifacial spasm, the level of myoclonus, and the prime muscles of torticollis etc. Sometimes the myographic guidance may be critical for choosing the exact injecting site of botulinum toxin. These several decades various electroencephalographic and evoked potential tests has been utilized in the electrophysiological laboratories to understand the basic pathophysiology of myoclonus, spasticity and other central motor dysfunctions. It could be one of the breakthroughs in the area of behavorial neurology that the brain function can be mapped by the spontaneous or evoked electrical activities of nervous system since the movement related potentials (MRPs) had been studies for several decades. Various reflex tests such as masseter reflex, blink reflex, click evoked vestibulocollic reflex, facial reflex, stretch reflex, flexor reflex, H-reflex, H-reflex recovery curve, vestibular inhibition of H-reflex, reciprocal inhibition, recurrent or Renshaw reflex, Ib inhibition, cutaneous reflex have been also used to understand normal or abnormal physiology in movement disorders. Polysomnography, posturography and gait studies are also applied in clinical neurology in association with with movement disorders which are useful in deciding the treatment regimen.

• Nutrition Research and Practice
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• v.14 no.2
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• pp.127-133
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• 2020

BACKGROUND/OBJECTIVES: Non-small cell lung cancer is mostly recognized among other types of lung cancer with a poor prognosis by cause of chemotherapeutic resistance and increased metastasis. Luteolin has been found to decrease cell metastasis. However, its underlying mechanisms remain unresolved. The objective of this study was to examine the effect (and its mechanism) of luteolin on the migration and invasion of human non-small cell lung cancer A549 cells. MATERIALS/METHODS: Cell viability was investigated by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. Wound healing and transwell assays were evaluated to assess migration and invasion, respectively. Western blot analysis and immunofluorescence were further performed to investigate the role of luteolin and its mechanisms of action. RESULTS: Administration with up to 40 μM luteolin showed no cytotoxic activity on lung cancer A549 cells or non-cancer MRC-5 cells. Additionally, luteolin at 20-40 μM significantly suppressed A549 cells' migration, invasion, and the formation of filopodia in a concentration-dependent manner at 24 h. This is similar with western blot analysis, which revealed diminished the phosphorylated focal adhesion kinase (pFAK), phosphorylated non-receptor tyrosine kinase (pSrc), Ras-related C3 botulinum toxin substrate 1 (Rac1), cell division control protein 42 (Cdc42), and Ras homolog gene family member A (RhoA) expression levels. CONCLUSIONS: Overall, our data indicate that luteolin plays a role in controlling lung cancer cells' migration and invasion via Src/FAK and its downstream Rac1, Cdc42, and RhoA pathways. Luteolin might be considered a promising candidate for suppressing invasion and metastasis of lung cancer cells.

• Proceedings of the Korea Society of Environmental Toocicology Conference
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• 2003.10a
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• pp.181-181
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• 2003

We have studied the mechanism of action of TCDD on CYP1A1 promoter activity in both Hepa Ⅰ and MCF-7 cells using transient transfection system with p1A1-Luc reporter gene. When HDAC inhibitors, such as trichostatin A, HC toxin and a novel HDAC inhibitor, IN2001 were cotreated with TCDD to the cells transfected with plAt-Luc reporter gene, the basal promoter activity of CYP1A1 was increased by HBAC inhibitors. Also, in MCF-7 human breast cancer cells, HDAC inhibitors, such as IN2001 and trichostatin A increased the basal activity of CYP1A1 promoter but TCDD stimulated CYP1A1 promoter activity was not changed by HDAC inhibitors. And, in stably-transfected Hepa Ⅰ cells with p1A1-Luc, HDAC inhibitors increased the basal promoter activity only Also, we have investigated the effects of HDAC inhibitors on the human breast and prostate cancer cells in terms of cell proliferation and apoptosis based on SRB assay. IN2001 as well as trichostatin A inhibited the MCF-7, MDA-MB-231, MDA-MB-468, T47D, ZR75-1, PC3 cell growth dose-dependently. The growth inhibition of these cells with HDAC inhibitors was associated with profound morphological change, which suggests the HDAC inhibitors induced apoptosis of cells. The result of cell cycle analysis after 24h exposure of IN2001 showed G2/M cell cycle arrest in MCF-7 cells and apoptosis in T47D and MDA-MB-231 cells.

• The Journal of the Korean Society for Microbiology
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• v.17 no.1
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• pp.35-41
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• 1982

Enterotoxigenk E. coli is one of the major causative agents of the infantile diarrhea and traveler's diarrhea. The heat-labile enterotoxin is thought to be a virulence factor in the pathogenesis of the diarrhea and to be a marker for identification of the enterotoxigenic E. coli from non pathogenic E. coli. Therefore knowledge about the heat-labile enterotoxin is essential not only for understanding the pathogenesis but also for the diagnosis of the diarrhea. However the in-vitro heat-labile enterotoxin production is reported to be greatly affected by the cultural condition. In this regards, this study was designed to know the optimal conditions for the production of the heat-labile enterotoxin by assaying the permeability factor in the 18 hours culture supernatant of E. coli 08K25(B2) H9 and of E. coli 015 H11. Results obtained were summerized as follows: 1. Amounts of heat-labile enterotoxin produced were greater at initial pH 8.5 than at 7.0 of CYES-2 broth culture. However, the bacterial growth itself was more abundant at 7.0 than at 8.5. 2. Heat-labile enterotoxin per unit volume of culture supernatant was greater at shaking culture than at standing culture condition, but ratio of the enterotoxin produced over the unit mass of E. coli calculated was greater at standing culture than shaking culture condition, indicating that the greater yields of the toxin produced at shaking culture was due to increase in E. coli cell mass compared to the standing culture condition: 3. The enterotoxin produced in the lincomycin(128 microgram/ml) supplemented media was 5 or 11 times greater on the basis of enterotoxin per unit mass of E. coli, compared to the lincomycin-non-supplemented media, indicating that lincomycin itself increases the enterotoxin production. 4. Treatment of 18 hours culture of E. coli with polymyxin B(0.2 mg/ml) for 1 hour increased the yields of enterotoxin amounting to 2 or 5 times of the non-treated control cultures.

• Microbiology and Biotechnology Letters
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• v.35 no.3
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• pp.250-254
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• 2007

Bacillus thringiensis strain 108 was isolated from soil and had nematicidal activity against second stage juvenile of plant root-knot nematode, Meloidogyne incognita. The strain 108, a rod shape, spore forming and Gram positive bacterium, produced lecithinase, catalase, and ${\delta}$-endotoxin. The strain 108 belongs to H serotype 3, Bacillus thuringiensis var. kurstaki. A nematicidal substance of the strain 108 was partially purified on Sephadex G-25 gel filtration, activated carbon adsorption, silica gel adsorption, and Sephadex G-10 gel filtration. $LC_{90}$ of the partially purified substance against M incognita was $1.2\;{\mu}g/ml$. The nematicidal substance was stable by heat treatment at $100^{\circ}C$ for 1hr, but was perfectly lost nematicidal activity after autoclave ($110^{\circ}C$, 30 min).