• Korean Journal of Veterinary Research
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• v.39 no.5
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• pp.878-895
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• 1999

Ischemic preconditioing (IPC), i.e., a preliminary brief episode of ischemia and reperfusion, has been shown to reduce the cell damage induced by long ischemia and reperfusion. Superoxide radical which is produced during reperfusion after ischemia was recognized as a factor of the ischemic injury and it is dismutated into $H_2O_2$ and $O_2$ by two types of intracellular superoxide dismutase (SOD), Cu,Zn-SOD in cytoplasm and Mn-SOD in mitochondria. Recently oxygen free radicals are suggested to induce the apoptosis, however mechanism of the reduced apoptosis by ischemic preconditioing was unknown, while many studies performed in mammalian heart indicated that ATP-sensitive $K^+$ ($K_{APT}$) channel activation related with the protective effects. The aim of present study is to investigate 1) whether IP upregulate the Cu,Zn-SOD and Mn-SOD activities, and 2) whether ischemic preconditioning decreases apoptosis via $K_{APT}$ channel activation in timely reperfused skeletal muscle after long ishemia. The experimental animals, Sprague-Dawley rats weighing 250~300g, were divided into 8 groups; 1) control group, 2) ischemic preconditioning only groups, 3) pinacidil, a $K_{APT}$ channel opener, treatment only groups, 4) glibenclamide, a $K_{APT}$ channel blocker, treatment only groups, 5) ischemia groups, 6) ischemia after IPC groups, 7) ischemia and pinacidil treatment groups, and 8) IP and ischemia after glibenclamide pretreatment groups. Animals of the control group were administered with the vehicle (DMSO) alone. Pinacidil (1mg/kg) was administered intravenously 5 minutes after initiation of ischemia, and glibenclamide (0.5mg/kg) was injected intravenously 20 minutes before IPC. In rats that were ischemic preconditioned, the left common iliac artery was occluded for 5 minutes followed by 5 minutes of reperfusion by three times using vascular clamp. Ischemia was done by occlusion of the same artery for 4 hours. The specimens of left rectus femoris muscle were obtained immediately (0 hour), 12 hours, 24 hours after drug administrations, IP or ischemia and reperfusion. The immunoreactivities of SOD and its alterations were observed by use of sheep antihuman Cu,Zn-SOD and Mn-SOD antibodies on the $10{\mu}m$ cryosections. The incidencies of apoptosis were observed by TUNEL methods with in situ apoptosis detection kit on $6{\mu}m$ paraffine section. The results obtained were as follows : 1. After IPC, immunoreactivities of Cu,Zn-SOD mainly in the small-sized fibers were increased by 24 hours, that of Mn-SOD at 0 hour and 24 hours. 2. No significant changes in immunoreactivities of SOD was observed in the pinacidil and in the glibenclamide treatment only groups, and in the ischemia only groups. 3. The immunoreactivities of the Cu,Zn-SOD were increased in the ischemia after IPC groups and the ischemia and pinacidil treatment groups. 4. The immunoreactivities of the Cu,Zn-SOD in the IPC and ischemia after glibenclamide pretreatment groups were not increased except for the 12 hours reperfusion group. But, Mn-SOD immunoreactivities were increased in the 0 hours, 12 hours and 24 hours after reperfusion. 5. In the control group, the IPC only groups, and the pinacidil treatment only groups, negative or trace apoptotic reactions were observed, but the positive apoptotic reaction occured in the glibenclamide treatment groups. 6. Moderate or many number of apoptosis were revealed in the ischemia groups, and also the IPC and ischemia after glibenclamide pretreatment group except for 12 hours and 24 hours after reperfusion. However, the incidence of apoptosis was decreased in the ischemia after IPC groups and in the ischemia and pinacidil treatment groups. 7. There is a coincidence between the increase of Cu,Zn-SOD immunoreactivities and the decrease of apoptosis in the presence of ischemia and reperfusion. These results suggest that the protective effects of ishemic preconditioing may related to the SOD activation, and the ischemic preconditioning decreases the apoptosis partially via $K_{APT}$ channel activation in timely reperfused rat skeletal muscle. It is also suggested that inhibition of apoptosis by IPC may related with the SOD activation.

• Tuberculosis and Respiratory Diseases
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• v.45 no.4
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• pp.754-759
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• 1998

Background : Lung cancer is an important public health problem because of rapidly increasing malignancy in both sexes in relation with high smoking rate in Korea. Despite advances in therapeutic modalities and supportive cares, 5-year survival rate has improved only marginally during the past 2 decades. Therefore, the early detection of lung cancer is strongly needed for better prognosis and we conducted this study to review the clinical factors resulting in delayed diagnosis of lung cancer. Method: The clinical data such as presenting symptoms, duration for diagnosis, disease entities causing misdiagnosis or delayed diagnosis, were analyzed retrospectively in 154 patients with primary lung cancer diagnosed at Chungnam National university hospital from January to December in 1995. Results : 63 patients(40.9%) out of 154 patients were delayed diagnosed with the duration of 6.3 months compared with 3.6 months in patients diagnosed without delay. In delayed diagnosed group, Cough & sputum and dyspnea as presenting symptom were more critical than hemoptysis and chest pain, and doctor's delay was more critical than patient's delay. Tuberculosis(30/63) was most frequent disease entity causing delayed diagnosis, followed by pneumorua(9/63), COPD(6/63), heart diseases(5/63), etc.. Conclusion: It should be emphasized that any respiratory symptom be checked with chest X-ray to differentiate lung cancer and periodic check of chest X-ray be also needed for the longterm patients with any disease, especially with high risk group.

• Korean Journal of Clinical Laboratory Science
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• v.38 no.3
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• pp.196-202
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• 2006

Treatment of hepatitis B virus (HBV) with lamivudine is effective in suppressing virus replication and results in reduced inflammatory activity. However the most troublesome problem of lamivudine treatment is the emergence of lamivudine-resistant strains with amino acid substitution in the YMDD motif of DNA polymerase gene during the treatment. The aim of this study was to determine the mutation of YMDD motif (codon 552) and codon 528 in chronic HBV patients with lamivudine therapy using PCR-direct sequencing and to investigate the relationship between lamivudine mediated HBV mutation and HBeAg. HBV DNA was extracted from serum samples of HBV patients and amplified by nested PCR with two sets of primer pairs selected in HBV DNA polymerase gene. Amplified PCR product was analyzed by 2% agarose gel electrophoresis and direct sequencing. HBV mutation was detected in 124 out of 207 samples (60%). Single mutation was 50.8% for M552I, 43.5% for M552V, 5.7% for M552I/V and the L528M mutation was 67.0%. Double mutation was 43.6% for M552V/L528M, 33.1% for M552I/L528(wild type), 17.7% for M552I/L528M and 5.6% for M552I/V/L528M. Serine mutation at YMDD motif (M552S) was not found and the L528M mutation frequently accompanied M552V type. In this study, the typical difference of frequencies for HBV mutation depending on HBeAg was not found. Moreover, the PCR-direct sequencing method used in this study might be a powerful tool for the mutation study in clinical reference laboratories with high volume.

• The Korean Journal of Nuclear Medicine
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• v.38 no.1
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• pp.85-98
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• 2004

Purpose: Cellular uptake of $^{99}mTc$-sestamibi (MIBI) and $^{99}mTc$-tetrofosmin (TF) is low in cancer cells expressing multidrug resistance(MDR) by p-glycoprotein(Pgp) or multidrug related protein(MRP). Verapamil is known to increase cellular uptake of MIBI in MDR cancer cells, but is recently reported to have different effects on tracer uptake in certain cancer cells. This study was prepared to evaluate effects of verapamil on cellular uptake of MIBI and TF in several cancer cells. Materials and Methods: Celluar uptakes of Tc-99m MIBI and TF were measured in erythroleukermia K562 cell, breast cancer MCF7 cell, and human ovarian cancer SK-OV-3 cells, and data were compared with those of doxorubicin-resistant K562(Ad) cells. RT-PCR and Western blot analysis were used for the detection of mdr1 mRNA and Pgp expression, and to observe changes in isotypes of PKC enzyme. Effects of verapamil on MIBI and TF uptake were evaluated at different concentrations upto $200{\mu}M\;at\;1{\times}10^6\;cells/ml\;at\;37^{\circ}C$. Radioactivity in supernatant and pellet was measured with gamma counter to calculate cellular uptake ratio. Toxicity of verapamil was measured with MTT assay. Results: Cellular uptakes of MIBI and TF were increased by time in four cancer cells studied. Co-incubation with verapamil resulted in an increase in uptake of MIBI and TF in K562(Adr) cell at a concentration of $100{\mu}M$ and the maximal increase at $50{\mu}M$ was 10-times to baseline. In contrast, uptakes of MIBI and TF in K562, MCF7, SK-OV3 cells were decreased with verapamil treatment at a concentration over $1{\mu}M$. With a concentration of $200{\mu}M$ verapamil, MIBI and TF uptakes un K562 cells were decreased to 1.5 % and 2.7% of those without verapamil, respectively. Cellular uptakes of MIBI and TF in MCF7 and SK-OV-3 cells were not changed with $10{\mu}M$, but were also decreased with verapamil higher than $10{\mu}M$, resulting 40% and 5% of baseline at $50{\mu}M$. MTT assay of four cells revealed that K562, MCF7, SK-OV3 were not damaged with verapamil at $200{\mu}M$. Conclusion: Although verapamil increases uptake of MIBI and TF in MDR cancer cells, cellular uptakes were further decreased with verapamil in certain cancer cells, which is not related to cytotoxicity of drug. These results suggest that cellular uptakes of both tracers might differ among different cells, and interpretation of changes in tracer uptake with verapamil in vitro should be different when different cell lines are used.

• Journal of dental hygiene science
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• v.14 no.2
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• pp.150-157
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• 2014

The aim of this study was to suggest a convenient method of monitoring the gingival state through plaque detection. Quantitative Light-Induced Fluorescence-Digital (QLF-D), which can assess mature plaque, can be used to assess the oral hygiene status of individuals and to establish an adequate intervention plans for them. The subjects of the study participated in the clinical training at Department of Dental Hygiene, N University. The subjects completed questionnaires on general characteristics and oral hygiene methods. Then, photographs of maxillary and mandibular anterior teeth of the subjects were taken using the QLF-D. After the oral examinations, gingival state was recorded according to the $L{\ddot{o}}e$ & Silness's Gingival Index (GI). In addition, a plaque control record was calculated in percentage using disclosing agent. The analysis of the relation between the plaque control record and the QLF-D scores showed positive correlation (r=0.638, p<0.001), and the analysis of the relation between the QLF-D scores and the gingival bleeding index scores also showed positive correlation (r=0.562, p<0.001). Besides, the study classified the participants into healthy gingiva group and the gingivitis group according to the classification criteria of GI, and when the difference of QLF-D scores between the groups was analyzed, the QLF-D scores were statistically significantly higher (t=-2.785, p=0.007) in the gingivitis group ($1.71{\pm}1.545$) than the healthy gingiva group ($0.74{\pm}1.290$). When the differences in mean values of the QLF-D scores were analyzed against and the gingival bleeding index scores, the QLF-D scores of 0 and 1 belonged to the category of normal gingival state while the QLF-D scores of 2, 3 and 4 belonged to the category of gingivitis state. Therefore, it is deemed that the red fluorescence detected by the QLF-D from the mature supragingival plaque can be used for monitoring the state of gingivitis.

• Clinical and Experimental Pediatrics
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• v.48 no.5
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• pp.527-533
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• 2005

Purpose : Long-term administration of anticonvulsants in children with epilepsy may cause short stature, hypocalcemia and low bone mineral density. This study was performed for the early detection of abnormal bone metabolism in children with epilepsy on taking anticonvulsants. Methods : Thirty children aged 5 to 16 years who were diagnosed with epilepsy were enrolled in this study. All had taken anticonvulsants for more than one year. Bone mineral density of lumbar vertebra was measured by dual-energy X-ray absorptiometry. Serum calcium, phosphorous, alkaline phosphatase, 25-hydroxycholecalciferol[$25(OH)D_3$], parathyroid hormone, and urine deoxypyridinoline were measured as biochemical bone markers. Bone age and body mass index were also calculated. Results : Bone minreal density, body mass index, bone age, and height were significantly decreased in two female patients who had taken two antiepileptic drugs for more than four years and they also had chronic diseases such as cerebral palsy with microcephaly, encephalomalacia, and microcephaly with atrial septal defect. Bone mineral density had significant positive correlations with body mass index(P<0.01) and bone age(P<0.01). Conclusion : This study showed chronic medication of anticonvulsants in children may cause low bone mineral density and short stature. Bone age and body mass index could be the important surrogate markers to find the population at risk. More studies, including a large study population and long term cohort study, will be required.

• Tuberculosis and Respiratory Diseases
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• v.47 no.3
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• pp.321-330
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• 1999

Background : Early diagnosis and proper antibiotic treatment are very important in the management of ventilator-associated pneumonia (VAP) because of its high mortality. Bronchoscopy with a protected specimen brush (PSB) has been considered the standard method to isolate the causative organisms of VAP. However, this method burdens consumer economically to purchase a PSB. Another useful method for the diagnosis of VAP is quantitative cultures of aspirated specimens through bronchoscopic bronchoalveolar lavage (BAL), for which the infusion of more than 120 m1 of saline has been recommended for adequate sampling of a pulmonary segment. However, occasionally it leads to deterioration of the patient's condition. We studied the diagnostic efficacy of minibronchoalveolar lavage (miniBAL), which retrieves only 25 ml of BAL fluid, in the isolation of causative organisms of VAP. Methods: We included 38 consecutive patients (41 cases) suspected of having VAP on the basis of clinical evidence, who had received antibiotics before the bronchoscopy. The two diagnostic techniques of PSB and miniBAL, which were performed one after another at the same pulmonary segment, 'were compared prospectively. The cut-off values for quantitative cultures to define causative bacteria of VAP were more than $10^3$ colony-forming units (cfu)/ml for PSB and more than $10^4$ cfu/ml for BAL. Results: The amount of instilled normal saline required to retrieve 25 ml of BAL fluid was $93{\pm}32 ml$ (mean${\pm}$SD). The detection rate of causative agents was 46.3% (19/41) with PSB and 43.9% (18/41) with miniBAL. The concordance rate of PSB and miniBAL in the bacterial culture was 85.4% (35/41). Although arterial blood oxygen saturation dropped significantly (p<0.05) during ($92{\pm}10%$) and 10 min after ($95{\pm}3%$) miniBAL compared with the baseline ($97{\pm}3%$), all except 3 cases were within normal ranges. The significantly elevated heart rate during ($l25{\pm}24$/min, p<0.05) miniBAL compared with the baseline ($1l1{\pm}22$/min) recovered again in 10 min after ($111{\pm}26$/min) miniBAL. Transient hypotension was developed during the procedure in two cases. The procedure was stopped in one case due to atrial flutter. Conclusion: MiniBAL is a safe and effective technique to detect the causative organisms of VAP.

• Korean Journal of Environmental Agriculture
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• v.37 no.4
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• pp.291-301
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• 2018

BACKGROUND: Rice is one of the main sources for inorganic arsenic among the consumed crops in the world population's diet. Arsenic is classified into Group 1 as it is carcinogenic for humans, according to the IARC. This study was carried out to assess dietary exposure risk of inorganic arsenic in husked rice and polished rice to the Korean population health. METHODS AND RESULTS: Total arsenic was determined using microwave device and ICP-MS. Inorganic arsenic was determined by ICP-MS coupled with HPLC system. The HPLC-ICP-MS analysis was optimized based on the limit of detection, limit of quantitation, and recovery ratio to be $0.73-1.24{\mu}g/kg$, $2.41-4.09{\mu}g/kg$, and 96.5-98.9%, respectively. The inorganic arsenic concentrations of daily exposure (included in body weight) were $4.97{\times}10^{-3}$ (${\geq}20$ years old) $-1.36{\times}10^{-2}$ (${\leq}2$ years old) ${\mu}g/kg\;b.w./day$ (PTWI 0.23-0.63%) by the husked rice, and $1.39{\times}10^{-1}$ (${\geq}20$ years old) $-3.21{\times}10^{-1}$ (${\leq}2$ years old) ${\mu}g/kg\;b.w./day$ (PTWI 6.47-15.00%) by the polished rice. CONCLUSION: The levels of overall exposure to total and inorganic arsenic by the husked and polished rice were far lower than the recommended levels of The Joint FAO/WHO Expert Committee on Food Additives (JECFA), indicating of little possibility of risk.

• Analytical Science and Technology
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• v.23 no.6
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• pp.531-536
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• 2010

A quantitative analytical method has been established for the measurement of inosine 5'-monophosphate dehydrogenase (IMPDH) activity in human peripheral blood mononuclear cells (PBMCs) by ion-pair reversed-phase high performance liquid chromatography equipped with ultraviolet detection (HPLC/UV). IMPDH is a ${\beta}$-nicotinamide adenine dinucleotide hydrate (NAD+)-dependent dehydrogenase in which the enzyme converts inosine 5'-monophosphate (IMP) into xanthosine 5'-monophosphate (XMP). Its activity was measured by quantifying a HPLC chromatogram corresponding to XMP produced during the incubation of lysed PBMCs with IMP as a substrate and $NAD^+$ as a coenzyme. XMP produced was detected at a wavelength of 260 nm. The mobile phase was composed of a mixture of 37 mM potassium dihydrogen phosphate containing 7 mM tetra-n-butylammonium hydrogen sulfate adjusted to pH 5.5 and methanol (85:15, v/v) with a flow rate of 1 mL/min. The calibration curve was linear ($r^2$=0.999999) in the range of $0.2-50.0\;{\mu}M$ and the limit of quantification (LOQ) was $0.2\;{\mu}M$. The intra- and inter-day precisions were between 0.88-1.47% and 0.85-5.24%, respectively. The intra- and inter-day accuracies were between 98.74-99.99% and 99.95-101.65%, respectively. IMPDH activity in 11 Korean healthy volunteers ranged from 18.29 to 36.60 nmol/h/mg protein (mean = $27.70{\pm}6.28\;nmol/h/mg$ protein).

• Korean Journal of Agricultural and Forest Meteorology
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• v.23 no.3
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• pp.149-155
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• 2021

Early warning systems for weather risk management in the agricultural sector have been developed to predict potential wind damage to crops. These systems take into account the daily maximum wind speed to determine the critical wind speed that causes fruit drops and provide the weather risk information to farmers. In an effort to increase the accuracy of wind risk predictions, an artificial neural network for binary classification was implemented. In the present study, the daily wind speed and other weather data, which were measured at weather stations at sites of interest in Jeollabuk-do and Jeollanam-do as well as Gyeongsangbuk- do and part of Gyeongsangnam- do provinces in 2019, were used for training the neural network. These weather stations include 210 synoptic and automated weather stations operated by the Korean Meteorological Administration (KMA). The wind speed data collected at the same locations between January 1 and December 12, 2020 were used to validate the neural network model. The data collected from December 13, 2020 to February 18, 2021 were used to evaluate the wind risk prediction performance before and after the use of the artificial neural network. The critical wind speed of damage risk was determined to be 11 m/s, which is the wind speed reported to cause fruit drops and damages. Furthermore, the maximum wind speeds were expressed using Weibull distribution probability density function for warning of wind damage. It was found that the accuracy of wind damage risk prediction was improved from 65.36% to 93.62% after re-classification using the artificial neural network. Nevertheless, the error rate also increased from 13.46% to 37.64%, as well. It is likely that the machine learning approach used in the present study would benefit case studies where no prediction by risk warning systems becomes a relatively serious issue.