• Journal of Pharmaceutical Investigation
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• v.32 no.2
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• pp.113-117
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• 2002

Cyto-toxic effect of silver sulfadiazine (Ag-SD) on keratinocytes and its implication on wound healing process were investigated in $2^{nd}$ degree bum hairless mouse model. As a dermal model, HaCat (immortalized keratinocytes) monolayer culture in DMEM with 10% FBS was used. Cyto-toxicity of Ag-SD was estimated by measuring the cell viability using neutral red assay after adding the drug. The $2^{nd}$ degree bum was prepared on hairless mouse back skin (1 cm diameter) and dressings with Ag-SD were applied for 96 hr. The process of re-epithelialization and the presence of inflammatory cells were investigated and histology with Hematoxylin-Eosin staining was performed. Ag-SD displayed highly cyto-toxic effect on cultured HaCat cells in a concentration dependent manner $(1-100\;{\mu}g/mL)$. Topical application of Ag-SD (2%) could control the infection: no inflammatory cells were observed in histology. However the cyto-toxic effect of Ag-SD on skin cells induced the impairment in epidermal regeneration.

• Journal of Nutrition and Health
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• v.33 no.3
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• pp.289-295
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• 2000

In the present work we investigated the effect of regular physical exercise on the activities of erythrocyte antioxidant enzyme, plasma total radical-trapping antioxidant potential(TRAP) and plasma level of lipid peroxidation(malondialdehyde, MDA) in 64 healthy male, aged 34-67 years. The study population were divided in two groups: small amount of exerciser(exercise time less than 10min/d) and moderate amount of exerciser(exercise time more than 20min/d) according to their physical exercise habits measured by a questionnaire. Erythrocyte superoxide dismutase(SOD), glutathione peroxidase(GSH-Px) and catalase(CAT), plasma TRAP, as well as plasma MDA were determined. Erythrocyte GSH-Px and plasma TRAP were higher in moderate amount of exercisers than those in small amount of exercisers by 17% and 26%, respectively. No significant differences were observed in erythrocyte SOD, CAT and plasma MDA between the two groups. Mean exercise time was positively correlated with the erythrocyte GSH-Px activity and plasma TRAP significantly. The results would sugest that regular moderate exercise enhances antioxidant defences against reactive oxygen species and may increase the likelihood of a healthier life span.

• Journal of Veterinary Clinics
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• v.34 no.5
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• pp.392-395
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• 2017

A 2-year-old miniature poodle dog was referred to Seoul Animal Clinic for assessment of traumatic ocular lesion by cat claw. Corneal perforation accompanied by hyphema following iridal laceration was observed in the left eye. Topical antibiotics, mydriatics and systemic antibiotics/steroids were applied to treat severe uveitis with miosis and fibrinous exudate. Although lenticular lesion was explored after mydriasis, it was obscured by severe corneal edema around corneal perforation. Despite aggressive treatments, the uveitis became more serious in the next day. To prevent septic implantation syndrome from anterior lens capsule disruption, phacoemulsification surgery was performed. The anterior lens capsule disruption was detected during continuous curvilinear capsulorhexis. The left eye remained the vision with mild posterior capsule opacification and intermittent conjunctival hyperemia during seven-month follow-up.

• The Journal of Korean Association of Computer Education
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• v.6 no.2
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• pp.1-8
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• 2003

In existing the learner testing system, it has a weak point to determine differently the difficulty of each question which has been estimated by teacher's view and the subjective stand point. In this paper, we develops the learner testing system which supports the estimation of the individual ability of learner, provides the questions for suitable to the individual learner level, and able to estimate the question of individual that used by three parameters such as the difficulty parameter, discrimination parameter, and guessing parameter. Also, it is applied to three-parameters logistic model of IRT(Item Response Theory) for using CAT(Computer Adaptive Testing) technique.

• Advances in Traditional Medicine
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• v.5 no.1
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• pp.62-68
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• 2005

Doxorubicin is a powerful anticancer antibiotic extensively used in the treatment of several types of cancers. Long-term administration of this drug results in cumulative dose related cardiotoxicity due to enhanced production of free radicals leading to oxidative stress. Our earlier investigations have demonstrated significant antioxidant, anti-inflammatory and antitumour properties of Ganoderma lucidum extracts. We extended our investigations to evaluate the protective effect of Ganoderma lucidum extract against doxorubicin-induced cardiotoxicity. Administration of 3 doses of doxorubicin, 6 mg/kg body weights, i.p. per each dose, alternative days, showed dear signs of cardiotoxicity in rats. The drug enhanced serum creatine kinase (CK) activity and lipid peroxidation in tissue drastically. The drug also induced significant decrease in GSH level and activities of CAT, SOD and GPx. Administration of methanolic extract of G.lucidum (500 and 1,000 mg/kg body weight) significantly increased the level of GSH and activities of CAT, SOD and GPx. Activity of CK was significantly lowered in a dose dependent manner. The treatment also caused significant decrease in lipid peroxidation (MDA). The results thus indicated that methanolic extract of G.lucidum prevented oxidative stress caused by doxorubicin administration and the increase in serum CK activity and lipid peroxidation in the tissue. The experimental findings suggest the therapeutic potential of G.lucidum as adjuvant in cancer chemotherapy.

• Archives of Pharmacal Research
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• v.21 no.3
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• pp.315-319
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• 1998

Gastric smooth muscle of cats was used to investigate the involvement of protein kinase in vanadate-induced contraction. Vanadate caused a contraction of cat gastric smooth muscle in a dose-dependent manner. Vanadate-induced contraction was totally inhibited by 2 mM EGTA and 1.5 mM $LACI_3$ and significantly inhibited by $10\mu$M verapamil and $1\mu$M nifedipine, suggesting that vanadate-induced contraction is dependent on the extracellular $Ca^{2+}$ concentration, and the influx of extracellular $Ca^{2+}$ was mediated through voltage-dependent $Ca^{2+}$ channel. Both protein kinase C inhibitor and tyrosine kinase inhibitor significantly inhibited the vanadate-induced contraction and the combined inhibitory effect of two protein kinase inhibitors was greater than that of each one. But calmodulin antagonists did not have any influence on the vanadate-induced contraction. On the other hand, both forskolin ($1\mu$M) and sodium nitroprusside ($1\mu$M) significantly inhibited vanadate-induced contraction. Therefore, these results suggest that both protein kinase C and tyrosino kinase are involved in the vanadate-induced contraction which required the influx of extracellular $Ca^{2+}$ in cat gastric smooth muscle, and that the contractile mechanism of vanadate may be different from that of agonist binding to its specific receptor.

• Biomolecules & Therapeutics
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• v.1 no.1
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• pp.37-43
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• 1993

Electrical or chemical stimulation of many areas in the brainstem modulates activity of dorsal horn neurons (DHN). This is known to be mediated by a population of bulbospinal neurons. Yet, little is known about responses of DHNs to stimulation of the caudal ventrolateral medulla (CVLM). Thus, the purpose of the present study is to see if there is any change in activity of DHNs when CVLM is stimulated electrically. Thirty-one DHNs were recorded from dorsal horn of the spinal cord. Fourteen DHNs (45%) were classified as wide dynamic range neurons and 9 (19%) were high threshold cells, and 4 (13%) and 4 (13%) were deep and low threshold neurons, respectively. Among 31 neurons tested for responses to stimulation of CVLM, 21 DHNs (68%) were inhibited by the electrical stimulation of CVLM ($200{\mu}A,\;100{\mu}s$ duration, 100 Hz), and 9 cells (39%) did not show any change in neuronal activity. One neuron was excited by the stimulation. The electrical stimulation of CVLM not only inhibited spontaneous activity of DHNs but also inhibited evoked responses of DHNs to somatic stimulation in the receptive field. These data suggest that CVLM is one of the pain-modulatory areas that control transmission of ascending information of noxious input to the brain from the spinal cord.

• Proceedings of the Korean Society of Applied Pharmacology
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• 1995.04a
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• pp.77-77
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• 1995

Human immunodeficiency virus type 1 (HIV-1) contains several nonstructural genes which are required for the viral replication and disease pathogenesis. Among them, tat and nef genes encode an essential transactivator of HIV-1 LTR and a pluripotent protein which seems to be essential for the in vivo but not in vitro viral replication, respectively. We constructed two tat and n of defective HIV-1 and tested for their ability to replicate in several T cells. The defective viruses did not replicate in CD4$\^$+/ T cells, but rescued in the recombinant Jurkat-tat cell which also contains tat gene. The replication of tat and nef defective HIV-1 which expresses chloramphenicol acetyltransferase(CAT) gene was easily detected by a sensitive CAT assay. No revertant was identified during the passages of the mutant viruses for more than two months in Jurkat-tat cells. tat and n of defective HIV-1 could be used instead of wild type viruse for several purposes such as inhibitor screening and development of attenuated AIDS vaccine.

• Journal of Microbiology and Biotechnology
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• v.15 no.2
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• pp.296-301
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• 2005

The effect of aqueous methanol on the catalytic properties of porcine pancreatic lipase has been investigated. The k$_{CAT}$, values for the hydrolysis of N$^{alpha}$-benzyloxycarbonyl-L­lysine p-nitrophenyl ester at 0$^{circ}$C increased in a linear manner with increasing methanol concentration. However, the K$_{M}$ values were not influenced at methanol concentrations lower than $30\%$ and then began to increase at higher concentrations in an exponential fashion. Based on product analysis, the increase in k$_{CAT}$, with increasing methanol concentration can be accounted for by nucleophilic competition of methanol for the acyl enzyme intermediate, indicating that the rate-limiting step of the porcine pancreatic lipase-catalyzed reaction is deacylation under current experimental conditions. The exponential increase in K$_{M}$ at methanol concentrations higher than $30\%$ is attributed to the hydrophobic partitioning effect on substrate binding. There was no loss of lipase activity over a 4 h period in $60\%$ methanol concentration at pH$^{circ}$ 5.5 and 0$^{circ}$C. By monitoring the intrinsic fluorescence and absorbance, no evidence for structural changes by methanol was observed.

• Journal of Korean Biological Nursing Science
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• v.10 no.1
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• pp.1-10
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• 2008

Purpose: The purpose of this study was to investigate the cerebral infarction size, antioxidant enzyme activities and lipid peroxidation changes after 6 weeks of dietary soybean protein intake in a rat focal brain ischemia model. Method: Weaning Sprague-Dawley rats were fed with either modified AIN-93G diet containing casein 20% (control), 20% soybean protein isolate-based diet (S20), or 40% of soybean protein isolate-based diet (S40) for 6 weeks. The animals were subject to right middle cerebral artery occlusion for 2 hr. After 24 hr of recirculation, the rats were sacrificed. Antioxidant enzymes activities of superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPx) and thiobarbituric acid reactive substance (TBARS) level in the right brain were also measured. Result: There were no significant differences in the right cortical infarction volume, TBARS level, SOD and CAT activities among the three groups whereas the GPx activities of the S20 group were significantly higher than those of the control group (p=.02). Conclusion: Our results suggest that 20% of soybean protein may have a modulating effect on GPx and possibly have some protective effect against oxidative stress although it may enough to decrease cerebral infarction volume in rat focal brain ischemia model.