• The korean journal of orthodontics
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• v.27 no.1
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• pp.141-155
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• 1997

The purpose of this study was to evaluate the effectiveness of the Nd:YAG laser and the Er:YAAG laser on etching enamel for direct bonding of orthodontic bracket. The advantages of laser etching rather than conventional acid etching are to reduce the subsurface demineralization rate, to inhibit the spillage of acid onto uninvolved ""its of enamel, and to save the clinical manipulation time involving drying, trashing and drying again. 189 freshly extracted human premolars were prepared for this research. 165 out of them were divided into 11 groups of 15 teeth. One group was acid etching and the rest groups were irradiated with Nd:YAG laser by four different energy levels(100mj 10pps, 100mj 20pps, 150mj 20pps, 200mj 20pps) and with Er:YAG laser by six different energy levels(60mj 5pps, 60mj 10pps, 100mj 10pps. 200mj 10pps, 200mj l5pps, 400mj 10pps). Shear bond strength was tested with Instron after 24 hours, one week, and three weeks. Twenty-four out of 189 teeth were divided into twelve groups untreated control, acid etching, and ten laser irradiation subgroups. And the ultrastructural enamel surfaces of each group were observed with scanning electron microscope. The results were as follows; 1. The means and the standard deviations of shear bond strength of Nd:YAG and Er:YAU laser irradiation by different energy levels were obtained. 2. Shear bond strengths of Er:YAG laser irradiation groups were higher than those of Nd:YAG laser irradiation groups at the identical energy level. 3. Maximum bond strengths was achieved at the energy of I50mj, 20pps in Nd:YAG laser irradiation groups or 60mj, 10pps in Er:YAG laser irradiation groups. 4. It was acceptible for direct bonding to irradiate lb0mj 20pps with Nd:YAG laser or to irradiate 60mj 10pps with Er:YAG laser considering the results of shear bond strength tests and SEM obsesvation.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.13 no.4
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• pp.1699-1705
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• 2012

This study was conducted to examine the differences of the quality of chest compression between 10 cm higher position of rescuer's knee from the bottom and its bottom position during implementation of CPR. It selected randomly subjects out of 66 students who attend the Dept. of Emergency Medical Technology in G college, G metropolitan city as the first grader and divided them into 31 experimental group and 32 control group from Nov. 8 to 9, 2011. Mattress was spread 10 cm higher from the bottom(material: B4 Copy Paper) and on the bottom(material: PVC, size: $185{\times}125{\times}0.65cm$) and only chest compression was conducted for 2 minutes. Experiment was conducted with 1 Resusci Anne mannequin and the results of experiment were recorded with Laerdal PC Skill Reporting System. Data collected were analyzed with $x^2$-test and Fisher's exact probability test using SPSS 14.0 for Window, Mann-Whitney U-test, and Wilcoxon signed rank test. As a result of the study, it was found that 10 cm higher position of rescuer knee from the bottom than the bottom position and group below 170 cm in their height and 65 kg in their weight were more effective in proper depth of chest compression and average chest compression depth.

• Journal of Life Science
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• v.15 no.1 s.68
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• pp.87-93
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• 2005

This study investigated the response of GLUT -4 and GRP-78 expression in soleus muscle of streptozotocin-induced diabetic rats by imposing different exercise intensities. F344 rats were randomly divided into 4 groups (n=15 in each group): Control (Control), diabetes-operation (DO), diabetes with low intensity exercise (DLE) and diabetes with high intensity exercise (DHE). The rats in DLE and DHE groups were exercised for 8 weeks by treadmill running. Blood glucose levels in DO were significantly higher compared to that in NORMAL whereas DLE showed the most lowest level in blood glucose among diabetic groups. Diabetic groups exhibited significantly lower level in insulin change and DLE showed significantly higher insulin level among diabetic groups. GRP-78 in DO was significantly $(167.05\%)$ higher than that in Control. GRP-78 in DLE was $139.41\%$ which is significantly higher compared to Control but when compared to DO and DHE, it was significant low. GRP-78 in DHE was $194.64\%$ which doubled the protein level in Control and showed the most highest level in all groups. GLUT-4 in DO was significantly $(33.58\%)$ higher compared to Control. GLUT-4 in DLE showed $124.58\%$ which was significant high compared to Control, DO and DHE. GLUT-4 in DHE showed $26.91\%$ compared to Control and was the most lowest level among all groups. It seems clear that chiefly low intensity exercise benefits diabetic patients in controlling blood glucose. It was concluded that low intensity exercise induces translocation of GLUT-4 which results in increased blood inflow, thus GRP-78 expression is decreased.

• Journal of Veterinary Clinics
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• v.30 no.3
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• pp.172-177
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• 2013

The aim of this study was to evaluate the in vivo and in vitro efficacy of enrofloxacin-silver sulfadiazine (Baytril$^{(R)}$ otic, Bayer, USA) for the treatment of otitis externa in dogs. Twenty-four dogs with otitis externa were included in this double-blinded, randomized study. The experimental group was treated with the Baytril$^{(R)}$ otic and the distilled water was applied to the control group. Both groups were administered each solution twice daily for 7 days and next 7 days off treatment. On days 0, 7 and 14, clinical signs, bacteriological and fungal counts were graded using semi-quantitative scales, respectively. For the evaluation of in vitro efficacy of Baytril$^{(R)}$ otic, we also performed Minimal Inhibitory Concentration (MIC) test by agar dilution method against Staphylococcus pseudintermedius, Pseudomonas aeruginosa and Malassezia pachydermatis. In the experimental group, the sum of clinical scores was decreased 81.0% and microbial scores were significantly reduced 87.0% at days 14, compared with day 0. The results of MIC testing were showed the concentration of enrofloxacin and silver sulfadiazine in Baytril$^{(R)}$ otic is high enough to kill for 3 infectious agents. No adverse reactions were observed in any of the dogs during this study. These results suggest that Baytril$^{(R)}$ otic are efficient and safe treatment for canine otitis externa.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.7
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• pp.119-126
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• 2019

This study was conducted to investigate the effects of task oriented training on motor and cognitive function recovery in rats with induced Alzheimer's dementia. Thirty Sprague-Dawley rats were randomly assigned to a control group (n=15) and an experimental group (n=15). Training was given three times a week, for 20 minutes a session for 4 weeks. The cognitive and motor functions of the rats were evaluated by an eight arm radial maze test and ladder rung walk test. The eight arm radial maze test showed significant differences between groups according to the time of day 14 and 28 (p<.001). The difference in measured values according to the timing of the two groups was significant (p<.001). Additionally, there was a significant difference between the time and the group interaction (p<.001). The ladder rung walk test showed significant differences between groups according to the time of day 14 and 28 (p<.001). The difference in the measured values according to the timing of the two groups was significant (p<.001), and there was a significant difference between the time and the group interaction (p<.001). As a result, task oriented training for Alzheimer's dementia rats was found to have a positive effect on recovery of motor and cognitive function.

• Tuberculosis and Respiratory Diseases
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• v.44 no.4
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• pp.729-741
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• 1997

Background : We have recently reported that airway epithelial cells can produce RANTES and IL-8 in response to the stimulation of tubercle bacilli suggesting a certain role of airway epithelial cells in the pathogenesis of pulmonary tuberculosis. The pathogenesis of tuberculosis is determined by several factors including phagocytosis, immunological response of host, and virulence of tubercle bacilli. Interestingly, there have been reports suggesting that difference in immunological response of host according to the virulence of tubercle bacilli may be related with the pathogenesis of tuberculosis. We, therefore, studied the expressions and productions of RANTES and IL-8 in airway epithelial cells in response to tubercle bacilli(H37Rv, virulent strain and H37Ra, avirulent strain), in order to elucidate the possible pathophysiology of pulmonary tuberculosis. Methods : Peripheral blood monocytes were isolated from normal volunteers. Peripheral blood monocytes (PBM) were stimulated with LPS($10{\mu}g/ml$), H37Rv, or H37Ra($5{\times}10^5$ bacilli/well) along with normal control for 24 hours. A549 cells were stimulated with supernatants of cultured PBM for 24 hours. ELISA kit was used for the measurement of $TNF{\alpha}$ and IL-$1{\beta}$ production in supernatants of cultured PBM and for the measurement of RANTES and IL-8 in supernatants of cultured A549 cells. Northern blot analysis was used for the measurement of RANTES and IL-8 mRNA expression in cultured A549 cells. Results : $TNF{\alpha}$ and IL-$1{\beta}$ productions were increased in cultured PBM stimulated with LPS or tubercle bacilli(H37Rv or H37Ra) compared with the control. There was, however, no difference in $TNF{\alpha}$ and IL-$1{\beta}$ production between cultured PBM stimulated with H37Rv and H37Ra. RANTES and IL-8 expressions and productions were also increased in cultured A549 cells stimulated with LPS or tubercle bacilli compared with the control. RANTES and IL-8 mRNA expressions were significantly increased in cultured A549 cells stimulated with H37Ra-conditioned media(CM) compared with A549 cells stimulated with H37Rv-CM (p<0.05). However, there was no difference in RANTES and IL-8 productions between A549 cells stimulated with H37Rv-CM and H37Ra-CM. Conclusion : Airway epithelial cells can produce the potent chemokines such as RANTES and IL-8, in response to the stimulation of tubercle bacilli. These results suggest that airway epithelial cells may play a certain role in the pathogenesis of pulmonary tuberculosis. However, the role of airway epithelial cells in the pathogenesis of tuberculosis according to the virulence of tubercle bacilli was not clear in this study.

• Journal of Chest Surgery
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• v.42 no.3
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• pp.283-291
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• 2009

Background: Tracheal reconstruction after extended tracheal resection still remains as a major surgical challenge because good clinical outcomes are usually correlated with limited tracheal resection. Recent investigations with a using cryopreserved trachea for the reconstruction of a trachea have been carried out to overcome this problem. In this study, we analyzed viability of tracheas, which is an important determining factor for the success of transplanting a cryopreserved trachea and the development of post-transplantation tracheal stenosis, according to three different experimental factors: 1) the warm-ischemic time, 2) the cryopreservation solution and 3) the preserving temperature, to determine a better cryopreservation protocol and a better composition of the cryopreservation solution. Material and Method: Rats tracheas were harvested for different warm-ischemic times (0 hr, 12 hrs, 24 hrs). The tracheas were treated with recombinant insulin growth factor-1 (IGF) and they were stored at three different temperatures $(4^{\circ}C,\;-80^{\circ}C,\;-196^{\circ}C)$ for two weeks. After two weeks, we thawed the stored trachea and isolated the cells of the tracheas with using type II collagenase. We cultured the cells for seven days and then we compared the cellular viability by the MTT reduction assay. Result: Though cryopreservation is required to preserve a trachea for a longer time period, the viability of the tracheas stored at $-80^{\circ}C$ and $-196^{\circ}C$ was significantly reduced compared to that of the tracheas stored at $4^{\circ}C$. The viability of the tracheas with warm-ischemic times of 12 hrs and 24 hrs was also reduced in comparison to the tracheas with a warm-ischemic time of 0 hrs. Our data showed that the warm ischemic time and the parameters of crypreservation negatively affect on trachea viability. However, a cryopresrvation solution containing IGF-1 improved the cellular viability better than the existing cryopreservation solution. For the warm ischemic time group of a 0 hr, the addition of IGF-1 improved the viability of trachea at all the preserving temperatures. Conclusion: These experiments demonstrate that the viability of cryopreserved trachea can improved by modifying the components of the crypreservation solution with the addition of IGF-1 and reducing the warm-ischemic time.

• Clinical and Experimental Pediatrics
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• v.48 no.8
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• pp.886-893
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• 2005

Purpose : Kawasaki disease is the most common cause of systemic vasculitis in children less than 5 years of age. Recent immunohistochemistry findings suggest that many vascular growth factors play a role in the formation of the coronary artery lesions. Active remodeling of the coronary artery lesions in Kawasaki disease continues in the form of intimal proliferation and neoangiogenesis for several years after the onset of the disease. Intravenous immunoglobulin(IVIG) and corticosteroid have been used in the treatment of Kawasaki disease but the exact mechanism is not clear. We have investigated that IVIG and corticosteroid inhibited vascular endothelial growth factor(VEGF)-induced tube formation of endothelial cells in vitro on Matrigel assay. Methods : Human umbilical vein endothelial cells(HUVECs) were cultured and seeded on Matrigel coated 24 well plates in medium with or without the following agents : VEGF, VEGF plus IVIG, VEGF plus VEGF antibody, VEGF plus methylprednisolone, VEGF, IVIG plus methylprednisolone for 18 hours. The total length of tube structures in each photograph was quantified. Results : IVIG significantly inhibited the proliferation of HUVECs. The inhibitory effect of IVIG was also reversible. In the meantime, VEGF induced the differentiation of HUVECs into capillary like structures on Matrigel, which was inhibited by VEGF antibody in a dose-dependent manner. Interestingly, IVIG and methylprednisolone inhibited VEGF-induced tube formation of HUVECs. IVIG was more effective in inhibition than methylprednisolone alone. Conclusion : We revealed that VEGF induced the differentiation of HUVECs and this effect was inhibited by IVIG and methylprednisolone.

• Tuberculosis and Respiratory Diseases
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• v.51 no.2
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• pp.122-134
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• 2001

Background : Some chemotherapeutic drugs induce NF-${\kappa}B$ activation by degrading the $I{\kappa}B{\alpha}$ protein in cancer cells which contributes to anticancer drug resistance. We hypothesized that inhibiting $I{\kappa}B{\alpha}$ degradation would block NF-${\kappa}B$ activation and result in increased tumor cell mortality in response to chemotherapy. Methods : The "superrepressor" form of the NF-${\kappa}B$ inhibitor was transferred by an adenoviral vector (Ad-$I{\kappa}B{\alpha}$-SR) to the human lung cancer cell lines (NCI H157 and NCI H460). With a MIT assay, the level of sensitization to cisplatin and paclitaxel were measured. To confirm the mechanism, an EMSA and Annexin V assay were performed. Results : EMSA showed that $I{\kappa}B{\alpha}$-SR effectively blocked the NF-${\kappa}B$ activation induced by cisplatin. Transduction with Ad-$I{\kappa}B{\alpha}$-SR resulted in an increased sensitivity of the lung cancer cell lines to cisplatin and paclitaxel by a factor of 2~3 in terms of $IC_{50}$. Annexin-V analysis suggests that this increment in chemosensitivity to cisplatin probably occurs through the induction of apoptosis. Conclusion : The blockade of chemotherapeutics induced NF-${\kappa}B$ activation by inducing Ad-$I{\kappa}B{\alpha}$-SR, increased apoptosis and increasing the chemosensitivity of the lung cancer cell lines tested, subsequently. Gene transfer of $I{\kappa}B{\alpha}$-SR appears to be a new therapeutic strategy of chemosensitization in lung cancer.

• The Korean Journal of Nuclear Medicine
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• v.39 no.1
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• pp.34-43
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• 2005

Purpose: $^{99m}Tc$-sestamibi(MIBI) and $^{99m}Tc$-tetrofosmin have been used as substrates for P-glycoprotein (Pgp) and multidrug resistance associated protein (MRP), which are closely associated with multidrug resistance of the tumors. To understand different handling of radiotracers in cancer cell lines expressing Pgp and MRP, we compared cellular uptakes of $^{99m}Tc$-MIBI and $^{99m}Tc$-tetrofosmin. The effects of cyclosporin A (CsA), well-known multidrug resistant reversing agent, on the uptake of both tracers were also compared. Materials and Methods: HCT15/CL02 human colorectal cancer cells for Pgp expressing cells, and human non-small cell lung cancer A549 cells for MRP expressing cells, were used for in vitro and in vivo studies. RT-PCR, western blot analysis and immunohistochemistry were used for detection of Pgp and MRP. MDR-reversal effect with CsA was evaluated at different drug concentrations after incubation with MIBI or tetrofosmin. Radioactivities of supernatant and pellet were measured with gamma well counter. Tumoral uptake of the tracers were measured from tumor bearing nude mice treated with or without CsA. Results: RT-PCR, western blot analysis of the cells and irnrnunochemical staining revealed selective expression of Pgp and MRP for HCY15/CL02 and A549 cells, respectively. There were no significant difference in cellular uptakes of both tracers in HCT15/CL02 cells, but MIBI uptake was slightly higher than that of tetrofosmin in A549 cells. Co-incubation with CsA resulted in a increase in cellular uptakes of MIBI and tetrofosmin. Uptake of MIBI or tetrofosmin in HCT15/CL02 cells was increased by 10- and 2.4-fold, and by 7.5 and 6.3-fold in A549 cells, respectively. Percentage increase of MIBI was higher than that of tetrofosmin with CsA for both cells (p<0.05). In vivo biodistribution study showed that MIBI (114% at 10 min, 257% at 60 min, 396% at 240 min) and tetrofosmin uptake (110% at 10 min, 205% at 60 min, 410% at 240 min) were progressively increased by the time, up to 240 min with CsA. But increases in tumoral uptake were not significantly different between MIBI and tetrofosmin for both tumors. Conclusion: MIBI seems to be a better tracer than tetrofosmin for evaluating MDR reversal effect of the modulators in vitro, but these differences were not evident in vivo tumoral uptake. Both MIBI and tetrofosmin seem to be suitable tracers for imaging Pgp- and MRP-mediated drug resistance in tumors.