• Clinical and Experimental Pediatrics
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• v.53 no.7
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• pp.753-758
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• 2010

Purpose: It has been suggested that p16 has a role in glucocorticoid (GC)-related apoptosis in leukemic cells, but the exact mechanisms have yet to be clarified. We evaluated the relationship between the GC response and p16 expression in a lymphoma cell line. Methods: We used p16 siRNA transfection to construct p16-inactivated cells by using the B-cell lymphoblast cell line NC-37. We compared glucocorticoid receptor (GR) expression, apoptosis, and cell viability between control (p16+NC-37) and p16 siRNA-transfected (p16-NC-37) cells after a single dose of dexamethasone (DX). Results: In both groups, there was a significant increase in cytoplasmic GR expression, which tended to be higher for p16+NC-37 cells than for p16- NC37 cells at all times, and the difference at 18 h was significant (P<0.05). Similar patterns of early apoptosis were observed in both groups, and late apoptosis occurred at higher levels at 18 h when the GR had already been downregulated ($P$<0.05). Cell viability decreased in both groups but the degree of reduction was more severe in p16+NC-37 cells after 18 h ($P$<0.05). Conclusion: These results suggest a relationship between GR expression and cell cycle inhibition, in which the absence of p16 leads to reduced cell sensitivity to DX.

• YAKHAK HOEJI
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• v.39 no.4
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• pp.444-449
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• 1995

Primary cultures of rat cortical and chicken embryonic brain cells were employed to establish a reliable screening method for natural products blocldng or enhancing glutamate-induced neurotoxicity. Exposure of primary cultured rat cortical cells or chicken embryonic brain cells to high dose of glutamate resulted in the fragmentation of neutites and consequent neuronal death. The level of cytoplasmic lactate dehydrogenase(LDH), indicator for cell survival in cultures, was significantly reduced at exposure to glutamate. For the practical application of the methods, series of concentrations of plants extracts and positive control were applied prior to the glutamate insult on primary cultures of rat cortical and chicken embryonic, brain cells. Relative LDH level in cells was measured for the estimation of the effect of the test materials on the glutamatergic neurons. The validity of the present screening method for natural products acting on glutamatergic neurons was examined with dextromethorphan, a known glutamatergic antagonist. The treatment of 100 $\mu{M}$ dextromethorphan prevented the reduction of LDH in rat cortical and chicken embryonic brain cells caused by glutamate insult keeping 60% and 90% of LDH level in normal control, respectively. Above results indicate that primary cultures of rat cortical and chicken embryonic brain cells could be proper systems for the screening of potential natural agents acting on glutamatergic, neurons. Between the two types of cultures, primary culture of chicken embryonic brain cells seemed to be a better system for the primary screening, since it is technically easier and economical compared to that of rat cortical cells.

• Food Science and Preservation
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• v.8 no.2
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• pp.206-212
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• 2001

Water extract of green tea(GTW) and 70% ethanol extract of green tea(GTE) were prepared for the test of antibacterial activity. The sensitivity of Staphylococcus aureus and Salmonella typhimurium to the green tea extracts in various pH of culture broth was tested. Tryptic soy broth(TSB) containing 0∼2%(w/v) of green tea extracts was adjusted to pH 5.0∼7.0 and inoculated with 10$\^$5/∼10$\^$6/ cells/ml of each bacteria. The plate counting method and clear zone test were used to determine inhibitory effect of green tea extracts. Green tea extracts completely inhibited the growth of S. aureus at 0.5% level and bactercidal at 0.5∼1.0% level of GTW and GTE at pH 5.0∼7.0. Green tea extracts were bactercidal to S. typhimurium at 1.5∼2.0% level of GTW and 1.0∼2.0% level of GTE at pH 7.0. Sal. typhimurium was more resistant than S. aureus. in same concentration of green tea extracts at same pH. The resistance of S. aureus and Sal. typhimurium was increased with decreasing pH of culture broth. The morphology of S. aureus cells treated with green tea extracts showed damage of cell wall and cytoplasmic membrane. Severely damaged cells of S. aureus lost electron dense material and cytoplasm. Green tea extracts stimulated autolysis and cell death of S. aureus. This result suggests that green tea extracts can be used as an effective natural antibacterial agent in food.

• Restorative Dentistry and Endodontics
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• v.13 no.1
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• pp.7-19
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• 1988

The object of this paper was to investigate the histopatological changes on dog's pulp under cavitation by irradiation of the $CO_2$ laser. The subjects were derived from four dogs, and irradiated 113.23 J/$mm^2$, 283.09 J/$mm^2$, 566.08 J/$mm^2$ in Group I, II, and III respectively. The dogs were sacrificed immediately, 24 hour, 72 hour and 1 week after $CO_2$ laser treatment. For light microscopic examination, routine H-E and PAS stains were employed. For electron microscopic observation, the teeth were fixed in 1% paraformaldehyde and 1% glutaraldehyde, decalcified teeth in 10% EDTA were stained by uranyl acetate and lead citrate. The observation was made with a Hitachi H-500 model electron microscope. The following results were obtained in this study: 1. At the early stage of the experimental sub-groups-immediately, 24 hour, 72 hour samples of Group I, II and III-coagulation necrosis and hyperemia were observed in odontoblastic and subodontoblastic pulpal layer. 2. At the 1 week sub-group of Group I, II, regenerative hyperplasia of the odontoblasts without coagulation necrosis were revealed, in addition to thickened predentin. On he other hand coagulation necrosis and atrophic change accompanying with hyperplasia were found at the 1 week sub-group of Group III. 3. Ultrastructurally, the odontoblasts appeared nuclear degeneration, vacuolar change of cytoplasmic organelles and rupture of plasma membrane at the early stage of the experimental period of all groups. 4. Under spectrohelioscopic examination, regenerative odontobalsts were seen at the 1 week specimens of Group I, II and III. 5. The pulpal response occured at 113-566 J/$mm^2$. The pathologic change of pulp tissue occured at the early experimental period but regeneration of odontoblasts could be seen after 1 week.

• BMB Reports
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• v.32 no.6
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• pp.585-593
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• 1999

The water and methanol extracts of Artemisia argyi showed significant cytotoxicities against J774A.1 cells but not so much against normal leukocytes. The cytotoxicities were found to be dependent on the extract concentration and the incubation time. The concentration of water and methanol extracts inhibiting 50% of cell proliferation ($IC_{50}$) were estimated to be 44.2 mg/ml and 71.6 mg/ml, respectively. In the presence of Artemisia argyi water extract, total superoxide dismutase (CuZnSOD and MnSOD) activities of media, cytoplasmic and mitochondrial fractions of J774A.1 cells increased in accordance with cytotoxicity. MnSOD was found to be the main component of enhanced total SOD activities, particulary in the mitochondrial fraction. In contrast to SOD, catalase and glutathione peroxidase (GPx) were not found in any instance of the current investigation. In addition, substantial amount of $O_2^-$ appeared to be generated in the mitochondrial fraction under the influence of Artemisia argyi. All data put together, it is postulated that Artemisia argyi extracts seem to stimulate $O_2^-$ generation in mitochondria of J774A.1 cells with concomitant increases of SODs. Since $H_2O_2$, the reaction product of SOD on $O_2^-$, is known to be readily converted to very toxic $OH{\cdot}$ in the absence of catalase and/or GPx cooperation, toxicity derived from ROS such as $O_2^-$, $H_2O_2$, and $OH{\cdot}$ may be the main cause of necrosis and/or apoptosis of J774A.1 cells.

• The Korean Journal of Pain
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• v.29 no.3
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• pp.158-163
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• 2016

Background: Phenol and alcohol have been used to ablate nerves to treat pain but are not specific for nerves and can damage surrounding soft tissue. Lidocaine at concentrations > 8% injected intrathecal in the animal model has been shown to be neurotoxic. Tests the hypothesis that 10% lidocaine is neurolytic after a peri-neural blockade in an ex vivo experiment on the canine sciatic nerve. Methods: Under ultrasound, one canine sciatic nerve was injected peri-neurally with 10 cc saline and another with 10 cc of 10% lidocaine. After 20 minutes, the sciatic nerve was dissected with gross inspection. A 3 cm segment was excised and preserved in 10% buffered formalin fixative solution. Both samples underwent progressive dehydration and infusion of paraffin after which they were placed on paraffin blocks. The sections were cut at $4{\mu}m$ and stained with hemoxylin and eosin. Microscopic review was performed by a pathologist from Henry Ford Hospital who was blinded to which experimental group each sample was in. Results: The lidocaine injected nerve demonstrated loss of gross architecture on visual inspection while the saline injected nerve did not. No gross changes were seen in the surrounding soft tissue seen in either group. The lidocaine injected sample showed basophilic degeneration with marked cytoplasmic vacuolation in the nerve fibers with separation of individual fibers and endoneurial edema. The saline injected sample showed normal neural tissue. Conclusions: Ten percent lidocaine causes rapid neurolytic changes with ultrasound guided peri-neural injection. The study was limited by only a single nerve being tested with acute exposure.

• Korean Journal of Clinical Laboratory Science
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• v.47 no.1
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• pp.6-10
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• 2015

Photodynamic therapy (PDT) apply photosensitizers and light. The purpose of this study was to evaluate the in vitro efficacy of PDT using blue LED (light emitting diode) with photofrin and radachlorin for Propionibacterium acnes. The colony forming units method was used to assess the antibacterial activity. Suspension (1 mL) containing P. acnes at $1{\times}10^5CFU/mL$ were prepared and then 2 fold serial diluted to $12.5{\mu}g/mL$ from $50{\mu}g/mL$ concentration of photofrin and radachlorin. After 60 minutes incubation, light was irradiated for 10 to 30 minutes using the following light source of wavelength 460 nm, each energy density 36, 72 and $108J/cm^2$. Bacterial growth was evaluated after 72 hours incubation in a Phenylethanol Blood Agar (PEBA) culture. In addition, flow cytometric analysis were performed to measure the live cell after PDT. Also transmission electron microscopy (TEM) was employed to evaluate the effect of pathogens by PDT. The PDT Group was perfectly killed to all kind of photosensitizers dose of $12.5{\mu}g/mL$ with irradiation of 10 minutes. Also other Groups were killed to all kind of photosensitizers dose of $6.25{\mu}g/mL$ with irradiation time of 20 and 30 minutes. The flow cytometry showed a lower number of viable bacteria in the PDT group compared to the control group. The images of the TEM results were showed in cytoplasmic membrane damage and partially deformed to cell morphologies. These results suggest that radachlorin and photofrin combine blue LED PDT can be effectively treated when was proved treatment for acnes therapy.

• Journal of Microbiology and Biotechnology
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• v.19 no.9
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• pp.932-945
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• 2009

Several species of Gram-positive bacteria have cell wall peptidoglycan (syn. murein) in which not all of the sugar moieties are N-acetylated. This has recently been shown to be a secondary effect, caused by the action of a peptidoglycan N-acetylglucosamine deacetylase. We have found that the opportunistic pathogen Listeria monocytogenes is unusual in having three enzymes with such activity, two of which remain in the cytoplasm. Here, we examine the enzyme (PgdA) that crosses the cytoplasmic membrane and is localized in the cell wall. We purified a hexa-His-tagged form of PgdA to study its activity and constructed a mutant devoid of functional Lmo0415 (PgdA) protein. L. monocytogenes PgdA protein exhibited peptidoglycan N-acetylglucosamine deacetylase activity with natural substrates (peptidoglycan) from both L. monocytogenes and Escherichia coli as well as the peptidoglycan sugar chain component N-acetylglucosamine, but not with N-acetylmuramic acid. As was reported recently [6], inactivation of the structural gene was not lethal for L. monocytogenes nor did it affect growth rate or morphology of the cells. However, the pgdA mutant was more prone to autolysis induced by such agents as Triton X-100 and EDTA, and is more susceptible to the cationic antimicrobial peptides (CAMP) lysozyme and mutanolysin, using either peptidoglycan muramidases or autolysis-inducing agents. The pgdA mutant was also slightly more susceptible than the wild-type strain to the action of certain beta-lactam antibiotics. Our results indicate that protein PgdA plays a protective physiological role for listerial cells.

• The Korean Journal of Physiology and Pharmacology
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• v.7 no.6
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• pp.333-339
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• 2003

It has been demonstrated that an unidentified cytosolic factor(s) reduces $K_{ACh}$ channel function. Therefore, this study attempted to elucidate the cytosolic factor. Fresh cytosol isolated from normal heart (FC) depressed the $K_{ACh}$ channel activity, but cytosol isolated from the ischemic hearts (IC) did not modulate the channel function. Electrophorectic analysis revealed that a protein of ${\sim}80 kDa was markedly reduced or even lost in IC. By using peptide sequencing analysis and Western blot, this 80 kDa protein was identified as transferrin (receptor-mediated $Fe^{3+}$ transporter, 76 kDa). Direct application of transferrin (100 nM) to the cytoplasmic side of inside-out patches decreased the open probability ($P_o$, 12.7${\pm}6.4%, n=4) without change in mean open time (${\tau}_o$, $98.5{\pm}1.3$%, n=4). However, the equimolar apotransferrin, which is free of $Fe^{3+}$, had no effect on the channel activity (N*$P_o$, $129.1{\pm}13.5$%, n=3). Directly applied $Fe^{3+}$ (100 nM) showed results similar to those of transferrin (N*$P_o$: $21.1{\pm}3.9$%, n=5). However $Fe^{2+}$ failed to reduce the channel function (N*$P_o$, $106.3{\pm}26.8$%, n=5). Interestingly, trivalent cation La3+ inhibited N*$P_o$ of the channel ($6.1{\pm}3.0$%, n=3). Taken together, these results suggest that $Fe^{3+}$ bound to transferrin can modulate the $K_{ACh}$ channel function by its electrical property as a polyvalent cation.

• Journal of Korean Academy of Oral and Maxillofacial Radiology
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• v.27 no.1
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• pp.141-165
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• 1997

Radiation-impaired wound healing in animal experiments was believed to be an another logical experimental model to understand the wound healing mechanism in patients. The purpose of this study was to reveal the block point which would result in impaired healing. Twenty four rats(Sprague-Dawley strains) were divided into two groups according to the time interval between irradiation and wounding. Group I, observing the healing effect on the 1st day and Group II are the healing effects on the 7th days after irradiation to the wound of the rat tongue. Experimental animals were sacrificed 3, 6, 12, and 24 hours after wounding. The specimens were examined by the light microscope and transmission electron microscope. The following results were obtained 1. Fibroblasts in both groups showed degenerative changes which were dilated mitochondria and rER, reduced microorganelle, vacuoles and little cytoplasmic process. 2. Average length between bands and Quantity of the newly produced collagen fibers around fibroblasts remained unchanged against control group. 3. The severity of degenerative change of the fibroblast and impairment of wound healing including shortening of the thickness of collagen fibers were more severe in the group II than in the group I.