• Journal of Periodontal and Implant Science
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• v.34 no.2
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• pp.333-344
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• 2004

The enamel matrix derivative (EMD) has been recently used in the periodontal regenerative techniques. The present study was established to investigate the influence of EMD on human periodontal ligament cells using expression of mRNA of periodontal ligament specific gene (PDLs)17, PDLs22, type I collagen when EMD applied to periodontal ligament cells. Periodontal ligament cells were obtained from a healthy periodontium and cultured in Dulbecco's modified Eagle's medium (DMEM) plus 10% fetal bovine serum and ${\beta}-glycerophosphate$ with ascorbic acid. Test groups were two; One adds EMD in culture media and another added EMD and Dexamethasone (DEX) in culture media. Positive control group added DEX in culture media, and negative control group adds niether of EMD nor DEX. $Emdogain^{(R)}$ (Biora, Sweden, 30 mg/ml) was diluted by 75 ${\mu}g/ml$ concentration to culture media. For reverse transcription-polymerase chain reaction (RT-PCR), total RNA isolated on days 0, 7, 14 and 21. mRNA of PDLs17 was expressed on days 14 and 21 in EMD or DEX group, and expressed on days 7, 14 and 21 in EMD plus DEX group, the other side, expressed on days 21 in negative control group. mRNA of PDLs22 expressed on days 7, 14 and 21 in EMD group, and expressed on days 14 and 21 in DEX group, and expressed on days 7, 14 and 21 in EMD plus DEX group. Negative control group expressed on days 14 and 21. Type I collagen was expressed on all days and all groups. These results indicate that EMD promotes differentiation of periodontal ligament cells, and this is considered to offer basis that can apply EMD to periodontal tissue regeneration technique.

• Journal of Korean Society of Water and Wastewater
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• v.29 no.6
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• pp.633-641
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• 2015

Waterborne infectious disease is induced by several pathogenic microbes such as bacteria, viruses and protozoans, and the cases caused by viral infection is currently increasing. Water treatment process could reduce the number of virus in the water, but there were many difficulties to completely remove the virus particles from water. Therefore, the membrane separation technology which was reported to effectively remove pollutants from raw water has attracted increasing attention and demand. Since its efficiency has been introduced, demands for evaluation method toward the membrane filtration process are increasing. However, progression of the method development is slow due to the difficulties in cultivation of several waterborne viruses from animal models or cell culture system. To overcome the difficulties, we used adenovirus, one of the commonly isolated pathogenic waterborne viruses which can grow in cell culture system in vitro. The adenovirus used in this study was identified as human adenovirus C strain. The adenovirus was spiked in the raw water and passed through the microfiltration membrane produced by Econity, a Korean membrane company, and then the viral removal rate was evaluated by real-time PCR. In the results, the amount of virus in the filtered water was decreased approximately by 5 log scale. Because coagulant treatment has been known to reduce filtering function of the membrane by inducing fouling, we also investigated whether there was any interference of coagulant. In the results, we confirmed that coagulant treatment did not show significant interference on microfiltration membrane. In this study, we found that waterborne virus can be effectively removed by membrane filtration system. In particular, here we also suggest that real-time PCR method can rapidly, sensitively and quantitatively evaluate the removal rate of virus. These results may provide a standard method to qualifying membrane filtration processes.

• Journal of Korean Neurosurgical Society
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• v.29 no.9
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• pp.1161-1170
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• 2000

Objective : The transverse hippocampal slice is one of the most commonly studied in vitro models of mammalian brain physiology. However, despite its broad usage, there has been no standardization of slice preparation techniques or recording condition. It is well known that variations in recording conditions can result in profound different effects to neuronal responses. Evoked field potentials, recorded extracellularly, were used to investigate the effects of variations in hippocampal slice preparation protocol on hypoxia responses of CA1 neurones. Material & Methods : Before hypoxic injury, hippocampal slices were incubated for 4 hours. During incubation period, the slices were placed in a incubation chamber($21^{\circ}C$) for recovery from preparation injury and then transferred to recording chamber($34^{\circ}C$) for more recovery and baseline electric recording with current stimulation(0.1Hz). Various time periods in incubation chamber and recording chamber were applied to each experimental group(group 1=60min : 180min, group 2=90min : 150min, group 3=180min : 60min, time in incubation chamber : time in recording chamber) before 10 min hypoxia produced by replacing 95% $O_2$+5% $CO_2$ mixed gas to 95% $N_2$+5% $CO_2$ gas. Calcium, Magnesium ions and several drugs effecting on glutamate receptor also were studied. Recoveries from hypoxic injury of hippocampal slices were estimated by percent recovery of population spike(PS). Statistic analysis of study were performed using paired t-test. Results : The percent recovery of PS after 10min hypoxia was considerably enhanced by increasing the period of current stimulation during incubation period before hypoxic injury. Temperature effect on the result of this experiment was also studied(group 4) but the result from this showed no statistic significance. Low magnesium ion concentration of artificial CSF(Mg-free aCSF) during incubation period enhanced the recovery of PS but low calcium (calcium-free) and high magnesium ion concentration(2mM) reduced it after hypoxic injury. L-glutamate($100{\mu}M$) and AP-5($50{\mu}M$) had no effect on the recovery of PS but CNQX($10{\mu}M$) in artificial CSF during incubation period markedly enhanced the recovery of PS. Co-treatment of AP-5($50{\mu}M$), CNQX($10{\mu}M$) and high magnesium concentration(2mM) enhanced recovery of PS in immediate following period of hypoxic injury but the effect of cotreatment after then decayed rapidly and lost statistic significance. Conclusions : Judging from above results, the condition of baseline recording is important in observing the recovery of population spike after hypoxia, and the time and the condition should be controled more strictly to obtain reliable results.

• Journal of Plant Biotechnology
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• v.40 no.4
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• pp.224-230
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• 2013

Lily is an important cut-flower in Korea and world as well due to it's a variety of flower colors and various sizes of flowers. To develop elite lily cultivars, conventional breeding techniques have been used so far. However, an introduction of tissue culture system in mass propagation of bulbs and regeneration of shoots with a high efficiency is prerequisite at this moment. Especially, growth of bulbs and shoots as well as reduction of browning is critical factor to proliferate bulbs with shoots of superior lines or cultivar in lily. For this purpose, we tried to test whether ascorbic acid, citric acid and silver nitrate in medium to facilitate growth of bulbs and shoots as well as reduction of browning of bulb scales in lily. As a result, ascorbic acid and silver nitrate showed no significant differences compared to control plants in the growth of bulbs and shoots. When bulb scales were treated with $150mg{\cdot}l^{-1}$ of citric acid, formations of shoots and bulbs showed best result. While, bulb scale treated with $100mg{\cdot}l^{-1}$ of citric acid showed the growth of shoot and root as well as increasing of fresh weight compared to other treatments. Regarding the reduction of browning, $150mg{\cdot}l^{-1}$ of ascorbic acid showed the best result with the less than 2%. Although more experiments with several commercial varieties are needed in the future to establish mass propagation of bulbs of lily, results obtained in this study are supposed to provide the basic knowledge and contribution in tissue culture system of lily.

• Journal of Ginseng Research
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• v.23 no.1 s.53
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• pp.13-20
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• 1999

We previously reported that Korean red ginseng (KRG) has a relaxation effect on the smooth muscles of corpus cavernosum via nitric oxide (NO) pathway and calcium and potassium channels. However, it is suggested that the active ingredients of KRG might be different depending on the sources of preparation, and there might be differences in actions for different compositions. We first investigated the composition of KRG saponins according to the extractions of the various sources of KRG, then with these extractions the relaxation effects were evaluated in vitro and hemodynamical in vivo using New Zealand white rabbit and rat corpus cavernosum. The total compositions of ginsenoside $(G-Rb_1,\;-Rb_2,\;-Rc,\;-Rd,\;G-Re,\;-Rf,\;-Rg_1)$ in fractionated KRG saponin designated as TS-1, TS-2, TS-3 were $41\%,\;40\%,\;and\;62\%,$ respectively, and the ratios of PD saponin and PT saponin (PD/PT) were 1,55, 1.72, 2.25, and 2.61, the values of which were statistically significant. In vitro studies using the rabbit corpus cavernosal muscle strips, the KRG saponin relaxed cavernosal strips in a dose-dependent manner, and same results were observed in in vivo studies, that KRG saponin increased the intracavernosal pressure in the rat. There was difference in the efficacy according to fractionation techniques. The differences in the total contents of ginsenosides did not affect relaxation, rather PT saponin content was statistically related to the degree of cavernosal relaxation, and this action presumed to be mediated by NO pathway and calcium and potassium channels. In conclusion, KRG exerts relaxation which is a key step in erection via combination of effects on NO system or calcium and potassium channels. The efficacy of this action is different to the sources of ginseng, which is affected by the different composition of ginsenosides $(G-Rb_1,\;-Rb_2,\;-Rc,\;-Rd,\;G-Re,\;-Rf,\;-Rg_1).$ Thus the further studies on the active ingredients such as minor ginsenosides and non-saponin components of red ginseng with maximum potency should be sought.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.43 no.2
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• pp.77-82
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• 2017

Objectives: The aim of this study was to compare the mechanical resistance of four different osteosyntheses modeled in two different sagittal split ramus osteotomy (SSRO) designs and to determine the linear loading in a universal testing machine. Materials and Methods: An in vitro experiment was conducted with 40 polyurethane hemimandibles. The samples were divided into two groups based on osteotomy design; Group I, right angles between osteotomies and Group II, no right angles between osteotomies. In each group, the hemimandibles were distributed into four subgroups according to the osteosynthesis method, using one 4-hole 2.0 mm conventional or locking plate, with or without one bicortical screw with a length of 12.0 mm (hybrid technique). Each subgroup contained five samples and was subjected to a linear loading test in a universal testing machine. Results: The peak load and peak displacement were compared for statistical significance using PASW Statistics 18.0 (IBM Co., USA). In general, there was no difference between the peak load and peak displacement related to osteotomy design. However, when the subgroups were compared, the osteotomy without right angles offered higher mechanical resistance when one conventional or locking 2.0 mm plate was used. One locking plate with one bicortical screw showed higher mechanical resistance ($162.72{\pm}42.55N$), and these results were statistically significantly compared to one conventional plate with monocortical screws (P=0.016) and one locking plate with monocortical screws (P=0.012). The difference in peak displacement was not statistically significant based on osteotomy design or internal fixation system configuration. Conclusion: The placement of one bicortical screw in the distal region promoted better stabilization of SSRO. The osteotomy design did not influence the mechanical behavior of SSRO when the hybrid technique was applied.

• The Korean Journal of Zoology
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• v.38 no.4
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• pp.523-530
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• 1995

Specific affinity binding sites for atrial natriuretic peptide (ANP) were Investigated in the pig ovarian tissues by in vitro autoradiographic techniques. In the pig ovary, the highest binding sites for 12514abeiled rANP(l~28) were localized in the granulosa cell layer of the forncles. The binding sies on theca layer of the ovarian follicles were mainly localized in the external layer, but none was observed In the Internal layer. In the corpus luteum, the binding site was not observed. The specific bindings of 200 pM of l2Sl4abelled rANP(l~28) to granulosa and theca externa layers were reversed completely by excess concentration (1 ~4) of unlabelled rANP(l~28) but not by 10 ~ of unrelated peptides, human angiotensin II and arginine vasopressin. The binding was also displaced by 1 ~ of desiGIn18, Ser19, Gly2O, leu21, Gly22I ANP(4~2g) (C- ANF) as a spedfic ligand of the ANP clearance receptor. Therefore these results indicate ~hat the biological and the clearance ANP receptors exist in the theca externa and granulosa layer of the pig ovary, and suggest that the ANP receptors may be related with the regulatory lundion of the ovarian follicular development including oocyte maturation.

• Clinical and Experimental Reproductive Medicine
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• v.45 no.3
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• pp.129-134
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• 2018

Objective: In frozen and thawed embryos, the zona pellucida (ZP) can be damaged due to hardening. Laser-assisted hatching (LAH) of embryos can increase the pregnancy rate. This study compared thinning and drilling of the ZP before frozen embryo transfer (FET). Methods: Patients were randomly allocated into two groups for LAH using thinning or drilling on day 2 after thawing. Twenty-five percent of the ZP circumference and 50% of the ZP thickness was removed in the thinning group, and a hole $40{\mu}m$ in diameter was made in the drilling group. Results: A total of 171 in vitro fertilization/intracytoplasmic sperm injection FET cycles, including 85 cycles with drilling LAH and 86 cycles with thinning LAH, were carried out. The thinning group had a similar ${\beta}$-human chorionic gonadotropin-positive rate (38.4% vs. 29.4%), implantation rate (16.5% vs. 14.4%), clinical pregnancy rate (36.0% vs. 25.9%), miscarriage rate (5.8% vs. 2.4%), ongoing pregnancy rate (30.2% vs. 23.5%), and multiple pregnancy rate (7.0% vs. 10.6%) to the drilling LAH group. There were no significant differences in pregnancy outcomes between subgroups defined based on age (older or younger than 35 years) or ZP thickness (greater or less than $17{\mu}m$) according to the LAH method. Conclusion: The present study demonstrated that partial ZP thinning or drilling resulted in similar outcomes in implantation and pregnancy rates using thawed embryos, irrespective of women's age or ZP thickness.

• Journal of Yeungnam Medical Science
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• v.15 no.2
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• pp.286-296
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• 1998

Different techniques for culturing respiratory epithelial cells have been developed to overcome the limitations of studies on in vivo and on bioptic material. Traditionally, culture systems are divided into organ cultures, explant cultures and dissociated cell cultures. The first two contain both epithelial and non-epithelial cells. However, in monolayer cultures of dissociated cells only epithelial cells are present, the effects observed are caused by a pure epithelial responses. The purpose of this study is to establish primary culture method of human nasal epithelium (HNEC) by monolayer culture of dissociated cells to evaluate the role of the epithelial cells in the allergic and non-allergic nasal inflammatory reactions. HNEC was prepared by primary culture method of monolayer culture of dissociated cells from human inferior nasal turbinate mucosa of septal deviation patients. Primary cultured cells were characterized by indirect immunofluorescence assay and transmission electron microscopy. The immunoreactivities of cytokeratin-pan and cytokeratin No. 8 were observed in cultured HNEC. However, the immnoreactivities of vimentin and von Willebrand factor were not observed in cultured HNEC. The tonofilaments and desmosome were observed in cultured HNEC. The cultured epithelial cells were identified to be pure nasal epithelial cells. The monolayer culture of dissociated cells could successfully be employed for further study to investigate the role of the epithelial cells in allergic or non-allergic nasal inflammatory diseases.

• Clinical and Experimental Reproductive Medicine
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• v.24 no.2
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• pp.153-165
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• 1997

In male reproducible health, fertility and IVF (in-vitro fertilization), semen analysis has been most important. Semen analysis can be divided into concentration, motional and morphological analysis of sperm. The existing method which was developed earlier to analyze semen concentrated on the sperm motility analysis. To provide more useful and precise solutions for clinical problems such as infertility, semen analysis must include sperm morphological analysis. But the traditional tools for semen analysis are subjective, imprecise, inaccurate, difficult to standardize, and difficult to reproduce. Therefore, with the help of development of microcomputers and image processing techniques, we developed a new sperm morphology analyzer to overcome these problems. In this study the agreement on percent normal morphology was studied between different observers and a computerized sperm morphology analyzer on a slide-by-slide basis using strict criteria. Slides from 30 different patients from the SNUH andrology laboratory were selected randomly. Microscopic fields and sperm cells were chosen randomly and percent normal morphology was recorded. The ability of sperm morphology analyzer to repeat the same reading for normal and abnormal cells was studied. The results showed that there was no significant bias between two experienced observers. The limits of agreement were 4.1%${\sim}$-3.8%. The Pearson correlation coefficient between readers was 0.79. Between the manual and sperm morphology analyzer, the same findings were reported. In this experiments the slides were stained by two different methods, PAP and Diff-Quik staining methods. The limits of agreement were 7.2%${\sim}$-5.7% and 6.0%${\sim}$-6.3%, respectively. The Pearson correlation coefficients ware 0.76 and 0.91, respectively. The limits of agreement was tighter below 20% normal forms. In the experiments of repeatability, 52 cells stained by PAP and Diff-Quik staining methods were analyzed three times in succession. Estimating pairwise agreement, the kappa statistic for the pairs were 0.76, 0.81, 0.86, and 0.75, 0.88, 0.88 respectively. In this study it was shown that there was good agreement between manual and computerized assessment of normal and abnormal cells. The repeatability and agreement per slide of computerized sperm morphology analyzer was excellent. The computer's ability to classify normal morphology per slide is promising. Based on results obtained, this system can be of clinical value both in andrology laboratories and IVF units.