• The Korean Journal of Pharmacology
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• v.29 no.2
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• pp.175-182
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• 1993

As it has been reported that the depolarization-induced ACh release is modulated by activation of presynaptic $A_1-adenosine$ heteroreceptor in hippocampus and various lines of evidence indicate the adenosine effect is magnesium dependent, the present study was undertaken to delineate the role of endogenus adenosine as a modulator of hippocampal acetylcholine release in this study. Slices from the rat hippocampus were equilibrated with $[^3H]-choline$ and the release of the labelled product, $[^3H]-ACh$, was evoked by electrical stimulation(3Hz, $5\;V\;cm^{-1},$ 2ms, rectangular pulses), and the influence of various agents on the evoked tritium outflow was investigated. Adenosine, in concentrations ranging from $0.3\;to\;100\;{\mu}M$, decreased the $[^3H]-ACh$ release in a dose-dependent manner without changing the basal rate of release. $DPCPX(1{\sim}10{\mu}M)$, a selective $A_1-receptor$ antagonist, increased the $[^3H]-ACh$ release in a dose-related fashion with slight increase of basal tritium release. And the effects of adenosine were significantly inhibited by $DPCPX(2{\mu}M)$ treatment. CPCA, a specific $A_2-agonist$, in concentration ranging from $0.3\;to\;30\;{\mu}M$ decreased evoked tritium outflow with increase of basal rate of tritium release, and these effects were also abolished by $DPCPX(2{\mu}M)$ pretreatment. But, $CGS(0.1{\sim}10{\mu}M)$, a recently introduced potent $A_2-agonist$, did not alter the evoked tritium outflow. When the magnesium concentration of the medium was reduced to 0 mM, there was no change in evoked ACh release by adenosine. In contrast, increasing the magnesium concentration to 4 mM, the inhibitory effects of adenosine were significantly potentiated. These results indicate that $A_1-adenosine$ heteroreceptor is involved in ACh-release in the rat hippocampus and the inhibitory effects of adenosine mediated by $A_1-receptor$ is magnesium-dependent.

• The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
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• v.23 no.2
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• pp.27-40
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• 2010

Background and Objective : Increasing interest in anti-aging and anti-wrinkling agents for the skin has triggered the recent outflow of researches and studies in this field. This study was designed to investigate the effects of bee venom on skin wrinkling and skin aging by testing the skin wrinkling, skin elasticity, trans-epidermal water loss (TEWL), free radical level, anti-oxidative agent level, and skin tissue after infusion of bee venom on hairless mouse. Materials and Methods : Fifteen hairless mice aged between 36~40 weeks were divided randomly into 3 Group; the Bee Venom Syringe Group, the Bee Venom Needle Group, and the control group. The Bee Venom Syringe Group were injected subcutaneously with bee venom (0.1cc in total) using an insulin syringe on three spots in the lumbar spine (one spot on the center and two spots 1~2cm to the side bilaterally). The Bee Venom Needle Group were pricked with bee venom-smeared acupuncture needles on three longitudinal spots in the lumbar spine each 1cm apart, after which the needles were removed 10 minutes later. The Control Group did not receive any form of intervention. All procedures took place thrice a week for four weeks, during which the mice were allowed free access to water and fodder. The mice were measured and compared in the weight, skin wrinkling scale, skin elasticity, and TEWL before and after the experiment. After the experiment, blood samples were taken to measure the free radical and anti-oxidative agent level, and the skin tissue was sliced for examination. Data was analyzed using the SPSS program (ver 12.0). The ANOVA analysis was used to compare and contrast the three groups, and t-test for paired samples was used to evaluate skin-wrinkling before and after experiment. The cut-off p-value of significance was set at p<0.05. Results : 1. Administration of bee venom did not cause serious weight loss or gain. 2. Compared to the control group, the Bee Venom Syringe Group and the Bee Venom Needle Group both showed a decrease in skin wrinkling scale after intervention. Especially, the Bee Venom Syringe Group showed a significant decrease (p<0.05). 3. Compared to the control group, the Bee Venom Syringe Group and the Bee Venom Needle Group both showed an increase in skin elasticity. Especially, the Bee Venom Syringe Group showed a significant increase (p<0.05). 4. No significant change in TEWL was found in the mice in all the three groups before and after experiment. 5. Free radical level was normal in all 15 mice in all the three groups, and anti-oxidative agent was not significantly different across the three groups. 6. The Bee Venom Syringe Group, the Bee Venom Needle Group, and the control group did not show any significant difference in the thickness of epidermis and dermis, infiltration of inflammatory cells, and skin wrinkling. The epidermis layer was relatively better preserved in the Bee Venom Syringe Group as compared to the Bee Venom Needle Group and the control group. Conclusion : Direct injection of bee venom on the hairless mouse using a syringe was found to improve wrinkling of the skin and increase skin elasticity but did not show effectiveness on skin dryness due to water loss. The bee venom appears to have suppressive effects on skin wrinkling, one of the symptoms of skin aging, through a process independent of suppression of free radicals or increase of anti-oxidative agent.

• Radiation Oncology Journal
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• v.15 no.3
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• pp.187-195
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• 1997

Purpose : To analyze the involvement of apoptosis regulatory genes p53, $p21^{wart/cip1}$ bax and bcl-2 in induction of apoptosis by radiation in murine tumors. Materials and methods : The radiation-sensitive ovarian carcinoma OCa-1, and the radiation-resistant hepatocarcinorna HCa-I were used. Tumors, 8 mm in diameter, were irradiated with 25 Gy and at various times after irradiation, ranging from 1 to 48 h, were analyzed histologically for apoptosis and by western blot for alterations in the expression of these genes. The p53 status of the tumors were determined by the polymerase chain reaction-single strand conformation polymorphism assay. Results : Both tumors were positive for wild-type p53. Radiation inducesd apoptosis in OCa-1 but not in HCa-1. Apoptosis developed rapidly, peaked at 2 h after irradiation and returned to almost the background level at 48 h In OCa-1 radiation upregulated the expression of p53, $p21^{wart/cip1}$. and the bcl-2/bax ratio was decreased. In HCa-1 radiation increased the expression of both p53 and $p21^{wart/cip1}$, although the increase of the latter was small The bcl-2/bax ratio was greatly increased. In general the observed changes occurred within a few hours after irradiation, and either preceded or coincided with development of apoptosis Conclusions : The development of apoptosis required upregulation of both p53 and $p21^{wart/cip1}$ as well as a decrease in bcl-2/bax ratio. In contrast, an increase in bcl-2/bax ratio Prevented apoptosis in the presence of upregulated p53 and $p21^{wart/cip1}$ . These findings indentified the involvement of multiple oncogenes in apoptosis regulation in vivo and demonstrate the complexity that may be associated with the use of a single oncogene assessment for Predicting the outcome of cancer therapy with cytotoxic agents.

• Journal of Environmental Health Sciences
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• v.37 no.4
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• pp.267-278
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• 2011

Objectives: A great number of hazardous agents can be emitted from various types of art-creation in a fine arts college, but little data on exposure assessment has been published. A variety of processes encompassing toxic or non-toxic materials, tools, and components are involved in a sculptor work at a fine art college. The aim of this study was to assess exposure levels to particulates and noise during sculpture classes in a college of fine arts. Methods: Students in sculpture classes participated in this study. Mass, number, and surface area concentrations of particulates, noise level, temperature and relative humidity were monitored by both personal and area sampling during the tasks of metal, wood, and stone sculpting. Results: The number and surface concentration of particulates was the highest in the task of wood sculpting, followed by metal and stone work. The mass concentration of particulates was the highest in stone sculpting (personal GM 3.0 mg/$m^3$, GSD 3.0), followed by wood (personal GM 1.5 mg/$m^3$, GSD 1.8) and metal work (personal GM 0.95 mg/$m^3$, GSD 1.51) in that order. Occupational exposure limits (OEL) for particulates depends on the type of particulate. For wood dust, 86% (six subjects) of the personal samples and all area samples exceeded the Korean OEL for wood dust (1 mg/$m^3$), while 20% (two subjects) among stone sculpting students were exposed above the Korean OEL (10 mg/$m^3$). In contrast, metal sculpting did not exceed the OEL (5 mg/$m^3$). For noise level, metal sculpting students (Leq 95.1 dB(A) in the morning, 85.3 dB(A) in the afternoon) were exposed the most, followed by stone sculpting (88.3 dB(A)), and wood sculpting (84.8 dB(A)) in that order. Compared with the 90 dB(A) of the Korean OEL and 85 dB(A) of the American Conference of Governmental Industrial Hygienists' threshold limit value (ACGIH-TLV) for noise, 100% of the subjects (five subjects) and area samples during metal sculpting in the morning session exceeded both OELs, but only three subjects (60%) exceeded the ACGIH-TLV in the afternoon session. For stone sculpting, 50% (one subject) and 100% (two subjects) exceeded the Korean OEL and ACGIH-TLV, respectively, but the area sample did not exceed either OEL. During wood sculpting, two subjects (40%) exceeded ACGIH TLV. Conclusions: This work evaluated the sculptors' exposure to particulate matter and noise in fine art college, and revealed a poor working environment for the participating students. Effective measures should be supplemented by the administration of colleges.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.13 no.4
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• pp.233-244
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• 2018

The purpose of this study was to improve awareness of network marketing business in South Korea, which takes a quite negative view of network marketing, to raise awareness of "starting up a business" as independent business owners, to assist them in building their own subjecthood in network business and entrepreneurial identity, and ultimately to give some suggestions on how to improve their self-directed entrepreneurial competency and the quality of their business management. To make an empirical analysis of 121 independent business owners of Korean native network marketing, the personal and background variables of the entrepreneurs were selected as independent variables, and entrepreneurship was selected as a mediator variable. The selected dependent variables were financial and non-financial business performances. A multiple regression analysis was conducted by inputting the variables. The findings of the study were as follows: It produced an effect of more financial performance when the innovation of the independent business owners of network marketing was better, and this innovation was possible to have only when they improved in entrepreneurial efficacy and locus of control. In contrast, only authenticity had an effect on boosting non-financial business performance among the factors of entrepreneurship. To have authenticity, it's necessary to strengthen achievement needs and awareness of locus of control among the personal characteristics of the independent business owners of network marketing. Among the factors of entrepreneurship, there was better authenticity when their personal networks were broader among their background characteristics. In addition, self-efficacy that was one of personal characteristics made a direct contribution to the enhancement of non-financial performance. As a result, independent business owners of network marketing are required to hold a strong belief in their own business, to be active in business activities and to have a high efficacy as spontaneous principal agents, and they also are required to have more adventurous, planned, active and propulsive achievement needs that enable them to attain the goals of their business and keep moving forward. Besides, they should foster their locus-of-control competency that is to control, endure and be responsible for a variety of phenomena or incidents that they face, and there will be better financial performance or non-financial performance only when they demonstrate their self-belief and confidence and when they have faith in and conviction about themselves. For independent business owners of network marketing, a consumer-centered thinking that entails authenticity and trustworthiness and touches the hearts of customers is a more effective marketing strategy than an egocentric thinking as sellers when they approach customers. And they are expected to make progress in terms of the quality of business management when their business attachment or enthusiasm is great enough to match their own efficacy with entrepreneurial identity or strike a balance between them.

• Pediatric Infection and Vaccine
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• v.9 no.2
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• pp.193-200
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• 2002

Purpose : This study was performed to investigate the epidemiology of viral acute lower respiratory tract infection(ALRI) in two different areas of Korea. Methods : A total of 796 patients hospitalized for ALRI aged 15 years or less from June 2000 to June 2001 in Samsung Seoul hospital(SSH) and Masan Fatima hospital(MFH) were enrolled. Viral etiologies were confirmed using nasopharyngeal aspirates. We compared etiologic agents, age distribution, clinical manifestations, and seasonal occurrence of viral ALRI between the two hospitals. Results : Virus was isolated in 208 patients(26.1%). The proportion of patients aged under 2 years in SSH was 60.2%, while those in MFH was 90.0%(P<0.05). Respiratory syncytial virus(RSV) was more prevalent in MFH, but adenovirus, influenza virus and parainfluenza virus were more prevalent in SSH(P<0.05). Croup and bronchiolitis occurred more frequently in MFH than in SSH(P<0.05). The most frequent viral pathogens causing bronchiolitis and croup were RSV and parainfluenza virus, respectively, in both hospitals. Adenovirus was the main cause of pneumonia in SSH, in contrast to RSV in MFH. In terms of tracheobronchitis, adenovirus was detected most frequently in SSH, whereas influenza virus-type A was mainly isolated in MFH. Similar pattern of seasonal occurrences of RSV, parainfluenza virus and influenza virus-type A was noted in both hospitals. Adenovirus was isolated sporadically throughout the study periods. Conclusion : Seasonal occurrence and clinical syndromes according to viral pathogens showed similar pattern in two areas. However, distribution of offending viruses was different, although this is mainly related to the different age distribution. An annual nationwide surveillance is necessary to understand the viral epidemiology associated with respiratory illnesses in Korea.

• Neonatal Medicine
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• v.16 no.2
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• pp.172-181
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• 2009

Purpose: To identify trends in causative bacterial organisms for neonatal sepsis and antimicrobial susceptibilities over 10 years in one neonatal intensive care unit. Methods: We retrospectively reviewed the cases of culture-proven neonatal sepsis between January 1998 and December 2007. The 10-year period was divided into two phases (phase I, 1998-2002; phase II, 2003-2007) to distinguish the differences during the entire period. Results: Total 350 episodes of neonatal sepsis were identified in 315 neonates. The common pathogens of early-onset sepsis were S. epidermidis, S. aureus, P. aeruginosa, and E. cloacae in phase I, and S. epidermidis and E. cloacae in phase II. In cases of late-onset sepsis, coagulase negative Staphylococcus, S. aureus, and K. pneumoniae were isolated frequently in both phases. The incidence of sepsis caused by multi-drug resistant organisms decreased with strict infection control. Gram positive organisms showed 0-20% susceptibility to penicillin, ampicillin, and cefotaxime in both phases. Sensitivity to amikacin for Enterobacter spp. increased, whereas P. aeruginosa showed decreased sensitivity in phase II. Between 50% and 60% of other gram negative bacteria, except P. aeruginosa, were susceptible to cefotaxime in phase II in contrast to phase I. Greater than 80% of gram negative bacteria were sensitive to imipenem except P. aeruginosa and ciprofloxacin in both phases. Conclusion: The trend in causative microorganisms and antimicrobial susceptibilities can be used as a guideline for selection of appropriate antibiotics. A particular attention should be paid to infection control, especially to reduce sepsis caused by multi-drug resistant organisms.

• Journal of Hospice and Palliative Care
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• v.22 no.4
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• pp.198-206
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• 2019

Purpose: The Act on Hospice and Palliative Care and Decisions on Life-sustaining Treatment for Patients at the End of Life was enacted in 2016 and has taken effect since 2018 February. The content of this act was based on Physician Orders for Life-Sustaining Treatment (POLST) in the United States and we modified it for terminal cancer patients registering hospice. The object of this study is to investigate preference and implementation rate for modified Korean POLST (MMK-POLST) items in hospice ward. Methods: From February 1, 2017 to April 30, 2019, medical records regarding MMK-POLST were retrospectively analyzed for all patients hospitalized in the hospice ward of Gyeongsang National University Hospital. Results: Of the eligible 387 total cohorts, 295 patients filled out MK-POLST. MK-POLST has been completed in 133 cases (44.1%) by the patient themselves, 84 cases (28.5%) by the spouse, and 75 cases (25.4%) by their children, respectively. While only 13 (4.4%) out of 295 MK-POLST completed patients refused the parenteral nutrition and 5 patients (1.7%) for palliative sedation, the absolute majority of 288 (97.6%) patients did not want cardiopulmonary resuscitation (CPR) and ventilators and 226 people (76.9%) for pressor medications. Kappa values for the matched strength of MK-POLST implementation were poor for all items except CPR, ventilators and palliative sedation. Conclusion: Hospice patients refused to conduct cardiopulmonary resuscitation, ventilators and pressor agents. In contrast, antibiotics, parenteral nutrition and palliative sedation were favored in the majority of patients.

• Journal of the Korean Magnetics Society
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• v.15 no.2
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• pp.100-105
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• 2005

$Ni_{0.9}Zn_{0.1}Fe_2O_4$ nanoparticles have been prepared by a sol-gel method. The structural and magnetic properties have been investigated by DTA/TGA, XRD, SEM, and $M\ddot{o}ssbauer$ spectroscopy, VSM. $Ni_{0.9}Zn_{0.1}Fe_2O_4$ powder that was annealed at $300^{\circ}C$ has spinel structure and behaved superparamagnetically. The estimated size of superparammagnetic Ni-Zn ferrite nanoparticle is around 10 nm. The hyperfine fields at 13 K for the A and B patterns were found to be 533 and 507 kOe, respectively. The blocking temperature ($T_B$) of superparammagnetic $Ni_{0.9}Zn_{0.1}Fe_2O_4$ nanoparticle is about 250 K. The magnetic anisotropy constant and relaxation time constant of $Ni_{0.9}Zn_{0.1}Fe_2O_4$ nanoparticle were calculated to be $1.6\times10^6\;ergs/cm^3$ and ${\tau}_0=5.0{\times}10^{-13}$ s, respectively. Also, Temperature increased up to $43^{\circ}C$ within 10 minutes under AC magnetic field of 7 MHz. It is considered that $Ni_{0.9}Zn_{0.1}Fe_2O_4$ powder that was annealed at $300^{\circ}C$ is available for biomedicine application such as hyperthermia, drug delivery system and contrast agents in MRI.

• Journal of fish pathology
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• v.36 no.2
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• pp.293-302
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• 2023

This study evaluated the acute toxicity induced by oxolinic acid (OA), neomycin-oxytetracycline combination (NEO-OTC) and florfenicol (FF) administered to guppy (Poecilia reticulata) by comparing standard formulations with commercial preparations (COOaqua curinpotion, COOaqua terafinpotion and COOaqua profenpotion, respectively) for ornamental fish at concentrations of 2-4%. NEO-OTC exhibited the highest acute toxicity in guppy, with no difference observed between the pstandard formulation and commercial preparation (LC₅₀ = 126.08 mg/L and 112.44 mg/L, respectively). OA acute toxicity was assessed in the form of sodium salt, with an LC₅₀ of 504.61 mg/L for the standard formulation and a slightly increased toxicity of 316.11 mg/L for the commercial preparation. In contrast, no mortality was observed during the 96-hour exposure period with the standard formulation in the form of oxolinic acid. The acute toxicity of FF was measured to be above 1,000 mg/L for the standard formulation; however, the commercial preparation significantly increased to 158.53 mg/L. These results indicate that toxicity can significantly increase in commercial formulations, especially those with low levels of active ingredients. This is presumed to be attributed to the organic solvents or solubilizing agents present in the commercial preparations, which may enhance toxicity. Additionally, guppy infected with Aeromonas salmonicida were effectively protected against mortality by administering OA, NEO-OTC and FF at concentrations of 50 mg/L, 100 mg/L and 15 mg/L, respectively, for 2 hours and at half the dose for 24 hours. This result indicates that liquid formulations containing low concentrations of antibiotics may partially increase toxicity, but there is no problem in effectively treating diseases in ornamental fish.