• Applied Microscopy
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• v.27 no.1
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• pp.87-100
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• 1997

To investigate the effects of mercuric chloride $(HgCl_2)$ on the differentiation of the cerebral neuron of chick embryo 10 days, the ultrastructural changes in nerve cells injected with a various doses of mercuric chloride were observed with transmission electron microscope. The enzyme activity of the some dehydrogenases, cerebral proteins and adenosine triphosphate (ATP) were also analyzed. The results obtained are as follows; The ultrastructural changes in 1.0 mg-injected group, the nuclear membranes were irregular, outer of mitochondria membrances dispressioned, their cristae were destroyed. In 2.0 mg-injected group, the nuclear envelops were destroyed and divided, were not observed organelle except of few ribosome, the RER and mitochondria. The number of polypeptide bands were separated by SDS-PAGE in the normal group were 38 bands. According to the in creased dose of mercuric chloride, contends of the bands were increased in 4 bands, but were decreased in 1 band. The activities of dehydrogenases were declined by increasing the dose of mercuric chloride. Lactate dehydrogenase (LDH) activity fatted to 61% in 2.0 mg-injected group. Malate dehydrogenase (MDH) activity fatted to 90% in 1.0 mg-injected group, greatly to 76% in 2.0 mg-injected group. Succinate dehydrogenase (SDH) activity decreased to 79% in 1.0 mg-injected group and greatly to 62% in 2.0 mg-injected group. ATP content in 1.0 mg-injected group was almost near to the normal level, but it was increased greatly in 2.0 mg-injected group.

• Journal of Microbiology and Biotechnology
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• v.22 no.6
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• pp.856-865
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• 2012

We describe the construction and immunobiological properties of a novel whooping cough vaccine candidate, in which the aroQ gene, encoding 3-dehydroquinase, was deleted by insertional inactivation using the kanamycin resistance gene cassette and allelic exchange using a Bordetella suicide vector. The aroQ B. pertussis mutant required supplementation of media to grow but failed to grow on an unsupplemented medium. The aroQ B. pertussis mutant was undetectable in the trachea and lungs of mice at days 6 and 12 post-infection, respectively. Antigen-specific antibody isotypes IgG1 and IgG2a, were produced, and cell-mediated immunity [CMI], using interleukin-2 and interferon-gamma as indirect indicators, was induced in mice vaccinated with the aroQ B. pertussis vaccine candidate, which were substantially enhanced upon second exposure to virulent B. pertussis. Interleukin-12 was also produced in the aroQ B. pertussis-vaccinated mice. On the other hand, neither IgG2a nor CMI-indicator cytokines were produced in DTaP-vaccinated mice, although the CMI-indicator cytokines became detectable post-challenge with virulent B. pertussis. Intranasal immunization with one dose of the aroQ B. pertussis mutant protected vaccinated mice against an intranasal challenge infection, with no pathogen being detected in the lungs of immunized mice by day 7 post-challenge. B. pertussis aroQ thus constitutes a safe, non-reverting, metabolite-deficient vaccine candidate that induces both humoral and cell-mediated immune responses with potential for use as a single-dose vaccine in adolescents and adults, in the first instance, with a view to disrupting the transmission cycle of whooping cough to infants and the community.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.27 no.6
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• pp.523-527
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• 2005

Allograft donations are commonly found to be contaminated. The most of tissue banks has promoted the use of ionizing radiation for the sterilization of biological tissues. The potential for transmission of human infectious diseases and contamination of microorganism has created serious concern for the continued clinical use of hard and soft-tissue allografts. Tissue banks have employed 15-25kGy for sterilization of hard and tendon allografts, which, according to the national standards, approaches the level at which the tissue quality is adversely affected for transplantation. The donations of allogeneic tissues to the Korea Tissue Bank over a 2-year period were reviewed, and the incidence and bacteriology of contamination were detailed. Clinical outcomes were determined for donors who had positive cultures at the time of retrieval and during the processing and they were compared with those of post sterilization. After exposure of the frozen block bone to 25kGy and the processed tissues to 15kGy of gamma irradiation, the authors were able to demonstrate complete inactivation of the bacteria. The aim of this study was to obtain the effects of gamma irradiation and the irradiation dose according to the type of tissue, through conventional microbiologic test without on influence of biocompatibility in allografts. The contamination rate after the final irradiation sterilization is 0% in the processed allografts. This may be due to the fact that the gamma radiation and processing steps are effective to control contamination.

• The Korean Journal of Physiology and Pharmacology
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• v.19 no.4
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• pp.357-363
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• 2015

The purpose of this study was to compare the inhibitory effect of bevacizumab on human Tenon's fibroblasts (HTFs) cultured from primary and recurrent pterygium. Cultured HTFs were exposed to 2.0, 5.0, 7.5, and 15.0 mg/mL concentration of bevacizumab for 24 hours. The 3-[4,5-dimethylthiazol- 2-yl]-2,5-diphenyl tetrazolium bromide and lactate dehydrogenase leakage assays were then performed to assess fibroblast metabolism and viability. The matrix metalloproteinase (MMP), procollagen type I C terminal propeptide (PIP), and laminin immunoassays were performed to examine extracellular matrix production. Changes in cellular morphology were examined by phase-contrast and transmission electron microscopy. Both metabolic activity and viability of primary and recurrent pterygium HTFs were inhibited by bevacizumab in a dose-dependent manner, especially at concentrations greater than 7.5 mg/mL. Both types of HTFs had significant decreases in MMP-1, PIP, and laminin levels. Distinctly, the inhibitory effect of bevacizumab on MMP-1 level related with collagenase in primary pterygium HTFs was significantly higher than that of recurrent pterygium. Significant changes in cellular density and morphology both occurred at bevacizumab concentrations greater than 7.5 mg/mL. Only primary pterygium HTFs had a reduction in cellular density at a bevacizumab concentration of 5.0 mg/mL. Bevacizumab inhibits primary and recurrent pterygium HTFs in a dose-dependent manner, especially at concentrations greater than 7.5 mg/mL. As the primary HTFs produces larger amounts of MMP-1 compared to recurrent HTFs, significant reduction in MMP-1 level in primary pterygium HTFs after exposure to bevacizumab is likely to be related to the faster cellular density changes in primary pterygium HTFs.

• Journal of the Korean Institute of Telematics and Electronics D
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• v.36D no.4
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• pp.48-56
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• 1999

In this paper, we have investigated experimentally the effects of initial oxygen concentration on oxygen pileup phenomenon and the diffusion of implanted impurities. 1.2 MeV $^{11}B^{+}$ and 2.2 MeV $^{31}P^{+}$ ions were implanted into p-type (100) Si wafers with a dose of 1${\times}10^{15}$ / $\textrm{cm}^2$. Secondary ion mass spectrometry(SIMS) measurements were carried out to obtain depth distribution profiles for implanted impurities and oxygen atoms after two-step annealing of $700^{\circ}C$(20 hours)+$1000^{\circ}C$(10 hours). Residual secondary defect distribution and annealing behabiour were also studied by cross-sectional transmission electron microscopy(TEM) observations. Oxygen pileup nearly $R_p$(projected range) were observed by SIMS measurements and considerable amount of residual secondary defect layer were observed by TEM observations. It can be seen that oxygen atoms are trapped at the secondary defects by the experimental results. Enhanced diffusions of boron and phosphorus to the bulk direction were observed with the increasing of initial oxygen concentration.

• The Korean Journal of Physiology and Pharmacology
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• v.12 no.6
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• pp.293-297
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• 2008

The effect of forskolin on corticostriatal synaptic transmission was examined by recording excitatory postsynaptic currents (EPSCs) in rat brain slices using the whole-cell voltage-clamp technique. Forskolin produced a dose-dependent increase of corticostriatal EPSCs (1, 3, 10, and $30{\mu}M$) immediately after its treatment, and the increase at 10 and $30{\mu}M$ was maintained even after its washout. When the brain slices were pre-treated with (DL)-2-amino-phosphonovaleric acid (AP-V, $100{\mu}M$), an NMDA receptor antagonist, the acute effect of forskolin ($10{\mu}M$) was blocked. However, after washout of forskolin, an increase of corticostriatal EPSCs was still observed even in the presence of AP-V. When KT 5720 ($5{\mu}M$), a protein kinase A (PKA) inhibitor, was applied through the patch pipette, forskolin ($10{\mu}M$) increased corticostriatal EPSCs, but this increase was not maintained. When forskolin was applied together with AP-V and KT 5720, both the increase and maintenance of the corticostriatal EPSCs were blocked. These results suggest that forskolin activates both NMDA receptors and PKA, however, in a different manner.

• Progress in Medical Physics
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• v.13 no.3
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• pp.139-148
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• 2002

The measured attenuation correction with transmission (Tx) scans produced quantitatively accurate images. However, it was not clear for optimal emission (Ex) and Tx scan time in PET imaging. This study was to evaluate acceptable Ex and Tx scan time by simulating clinical situations using various phantoms. Cylindrical and NEMA phantom were used for $^{18}$ F-PET scan using 2D protocol in GE Advance PETTM scanner. Cylindrical phantom was filled with 136 MBq 18F, and five regions of interests (ROI) were drawn on 23 slices. NEMA phantom had three inserts containing water, air and polytetrafluoro-ethylene (PTFE). Outside of these inserts were filled with 309 MBq of $^{18}$ F, and total 12 ROIs were drawn on 23 slices. Scans were carried out according to five Ex scan times: 2, 5, 10, 15, and 30 min, and nine Tx scan times: 2, 3, 4, 5, 7, 10, 15, 20, and 30 min. Images were reconstructed using measured attenuation correction, and ROI analyses were performed for all images, and mean, standard deviation (SD), coefficient of variation and percent errors were calculated. For cylindrical phantom study, ROI mean and SD were decreased as Ex and Tx time increased. Coefficients of variation were kept constant, when Tx was greater than 10 min. The amount of error decreased for the increment of Ex time from 10 min to 15 min was almost the same to that from 15 min to 30 min. In NEMA phantom Tx 15 min showed the lowest er개r level when the percent errors for three inserts were summed for all of the Ex times. This study suggested that Ex 15 min and Tx 15 min were acceptable as optimal scan time for the scanning protocol and the dose of radiopharmaceuticals used in these phantom study.

• Journal of Broadcast Engineering
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• v.12 no.6
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• pp.574-584
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• 2007

As the real time multimedia service become more popular, the needs of transmission with low delay and high quality are getting more stronger. Among those video compression technologies, the rate control method dose an important role in getting the effective data transmitting and the high image quality. In this paper, we combined the feature of CBR and VBR coding methods to propose a new bit-rate control method witch allows each frame to generates bits in the defined fluctuation range and applies a scene change detection at a part of frame and also can maintain low-delay and high quality even if the perfect VBR transmission environment is not guaranteed. The experiment result shows the proposed algorithm provides more effective method than TMN8 in real time application.

• The Korean Journal of Pharmacology
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• v.28 no.2
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• pp.171-179
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• 1992

Effects of a $M_1$ receptor antagonist, pirenzepine, a $M_2$ receptor antagonist, AF-DX116, and a nicotinic receptor antagonist, mecamylamine on the pressor responses to preganglionic sympathetic nerve stimulation (PNS) and McN-A-343 and DMPP in spinal (pithed) rabbits were investigated, in order to elucidate a functional role of $M_1$, $M_2$ and nicotinic receptors in ganglionic transmission. Pirenzepine and AF-DX116 selectively inhibited the McN-A-343-induced pressor response in chlorisondamine-treated rabbit and the BCh-induced bradycardia, respectively. Electrical stimulations of preganglionic sympathetic outflow at T8 level produced increases in blood pressure. Pirenzepine $(3\;{\mu}g/kg)$ significantly inhibited the PNS-induced pressor response and the degree of inhibition was not changed by increasing the doses to $100\;{\mu}g/kg$. AF-DX116 $(100\;{\mu}g/kg)$ had no effect on the PNS-induced pressor response. Mecamylamine inhibited the PNS-induced pressor response in a dose-dependent manner. The inhibitory action of mecamylamine was significantly augmented by combined-treatment with pirenzepine $(30\;{\mu}g/kg)$ but AF-DX116 $(100\;{\mu}g/kg)$ did not affect the inhibitory action of mecamylamine. McN-A-343 and DMPP elicited pressor response in the spinal rabbit. Pirenzepine and AF-DX116 dose-dependently inhibited the McN-A-343-induced pressor response but they did not affect DMPP-induced pressor response. Mecamylamine inhibited both pressor responses induced by McN-A-343 and DMPP. These results suggest that not only nicotinic receptors but also $M_1$ receptors play a facilitatory role in ganglionic transmission but $M_2$ receptors do not contribute the transmission in spinal (pithed) rabbits.

• Biomolecules & Therapeutics
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• v.19 no.2
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• pp.261-266
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• 2011

As recent reports suggest that nanoparticles may penetrate into cell membrane and effect DNA condition, it is necessary to assay possible cytotoxic and genotoxic risk. Three different sizes of magnetic nanoparticle silica (MNP@$SiO_2$) (50, 100 and 200 nm diameter) were tested for cytotoxicity and DNA damage using L5178Y cell. MNP@$SiO_2$ had constant physicochemical characteristics confirmed by transmission electron microscope, electron spin resonance spectrometer and inductively coupled plasma-atomic emission spectrometer for 48 h. Treatment of MNP@$SiO_2$ induced dose and time dependent cytotoxicity. At 6 h, 50, 100 or 200 nm MNP@$SiO_2$ decreased significantly cell viability over the concentration of 125 ${\mu}g/ml$ compared to vehicle control (p<0.05 or p<0.01). Moreover, at 24 h, 50 or 100 nm MNP@$SiO_2$ decreased significantly cell viability over the concentration of 125 ${\mu}g/ml$(p<0.01). And treatment of 200 nm MNP@$SiO_2$ decreased significantly cell viability at the concentration of 62.5 ${\mu}g/ml$ (p<0.05) and of 125, 250, 500 ${\mu}g/ml$ (p<0.01, respectively). Furthermore, at 48 h, 50, 100 or 200 nm MNP@$SiO_2$ decreased significantly cell viability at the concentration of 62.5 ${\mu}g/ml$ (p<0.05) and of 125, 250, 500 ${\mu}g/ml$ (p<0.01, respectively). Cellular location detected by confocal microscope represented they were existed in cytoplasm, mainly around cell membrane at 2 h after treatment of MNP@$SiO_2$. Treatment of 50 nm MNP@$SiO_2$ significantly increased DNA damage at middle and high dose (p<0.01), and treatment of 100 nm or 200 nm significantly increased DNA damage in all dose compared to control (p<0.01). Taken together, treatment of MNP@$SiO_2$ induced cytotoxicity and enhanced DNA damage in L5178Y cell.