• Journal of Embryo Transfer
• /
• v.27 no.3
• /
• pp.189-192
• /
• 2012

Although embryonic stem cells (ESCs) or ES-like cells are reported from many mammalian species other than the mouse, the culture system for murine ESCs may not be suitable to the other species. Previously many other research groups have modified either human or mouse ESC culture systems for bovine ESC culture. In this study, we compared three different culture mediums consisting of DMEM, ${\alpha}$-MEM or KnockOut$^{TM}$-DMEM (KO), which are modified from human or mouse ESC culture system, for the generation of bovine ESCs. In this study, some pre-requisite events which are important for establishment and long-term propagation of ESCs such as inner cell mass (ICM) attachment on feeder cells, primary colony formation and sustainability after passaging. Once the ICM clumps attached on feeder cells, this was designated as passage 0. In regards to the rate of ICM attachment, ${\alpha}$-MEM was superior to the other systems. For primary colony formation, there was no difference between DMEM and ${\alpha}$-MEM whereas KO showed lower formation rate than the other groups. For passaging, the colonies were split into 2~4 pieces and passed every 5~6 days. From passage 1 to passage 3, DMEM system seemed to be appropriate for maintaining putative bovine ESCs. On the other hand, ${\alpha}$-MEM tended to be more suitable after passage 6. Although ${\alpha}$-MEM support to maintain a ES-like cell progenies to passage 15, all three culture systems which are modified from human or mouse ESC culture media failed to retain the propagation and long-term culture of putative bovine ESCs. Our findings imply that more optimized alternative culture system is required for establishing bovine ESC lines.

• The Journal of the Korean dental association
• /
• v.37 no.7 s.362
• /
• pp.530-535
• /
• 1999

Detailed finishing of the occlusion is a clinical skill that has become difficult with the development of fixed appliances. Accuracy of bracket placement definitely improves with indirect technique, Several methods for the placement of orthodontic brackets on dental casts are currently used in the indirect bonding technique. These include attachment by means of bonding resins, adhesive tapes or sticky wax. This article presents the indirect procedures of our clinic, which use paste-paste chemically cured composites. Detailed laboratory and clinical procedure for dual tray method and other application of indirect bonding will be presented.

• Toxicological Research
• /
• v.35 no.4
• /
• pp.343-351
• /
• 2019

Many in vitro developmental toxicity assays have been proposed over several decades. Since the late 1980s, we have made intermittent attempts to introduce in vitro assays as screening tests for developmental toxicity of inhouse candidate products. Two cell-based assays which were developed two decades apart were intensively studied. One was an assay of inhibitory effects on mouse ascites tumor cell attachment to a concanavalin A-coated plastic sheet surface (MOT assay), which we studied in the early days of assay development. The other was an assay of inhibitory effects on the differentiation of mouse embryonic stem cell to beating heart cells (EST assay), which we assessed more recently. We evaluated the suitability of the assays for screening in-house candidates. The concordance rates with in vivo developmental toxicity were at the 60% level. The EST assay classified chemicals that inhibited cell proliferation as embryo-toxic. Both assays had a significant false positive rate. The assays were generally considered unsuitable for screening the developmental toxicity of our candidate compounds. Recent test systems adopt advanced technologies. Despite such evolution of materials and methods, the concordance rates of the EST and MOT systems were similar. This may suggest that the fundamental predictivity of in vitro developmental toxicity assays has remained basically unchanged for decades. To improve their predictivity, in vitro developmental toxicity assays should be strictly based on elucidated pathogenetic mechanisms of developmental toxicity.

• Korean Journal of Clinical Laboratory Science
• /
• v.50 no.2
• /
• pp.118-125
• /
• 2018

Tuberculosis (TB) is an infectious disease caused by Mycobacterium tuberculosis (MTB), but the genes associated with the host immune system can be attributed to the development of TB. The ITGB2 gene encodes the integrin beta 2 chain CD18 protein and is present on chromosome 21. The integrin beta 2 chain is an integrin expressed in leukocytes and plays a very important role in leukocyte maturation and attachment. ITGB2 plays an important role in the phagocytosis of MTB and the aggregation of leukocytes in MTB infections. This study examined the genetic polymorphisms of the ITGB2 gene between the TB case and normal control using Korean genomic and epidemiologic data. As a result, a statistically significant correlation was confirmed in 10 SNPs. The most significant SNP was rs113421921 (OR=0.69, CI: 0.53~0.90, $P=5.8{\times}10^{-3}$). In addition, rs173098, one of the significant 10 SNPs, is possibly located in a binding motif with the transcription factor cofactor p300, and can affect ITGB2 gene expression. These findings suggest that the pathogenesis of TB may be influenced by a range of genetic factors related to the immune function of the host, e.g., the reactions associated with the recruitment and attachment of leukocytes. The results of this study could be used to predict the infection control for tuberculosis in a patient-tailored manner.

• Parasites, Hosts and Diseases
• /
• v.53 no.3
• /
• pp.341-344
• /
• 2015

Toxoplasma gondii is an opportunistic protozoan parasite that can infect almost all warm-blooded animals including humans with a worldwide distribution. Micronemes play an important role in invasion process of T. gondii, associated with the attachment, motility, and host cell recognition. In this research, sequence diversity in microneme protein 6 (MIC6) gene among 16 T. gondii isolates from different hosts and geographical regions and 1 reference strain was examined. The results showed that the sequence of all the examined T. gondii strains was 1,050 bp in length, and their A + T content was between 45.7% and 46.1%. Sequence analysis presented 33 nucleotide mutation positions (0-1.1%), resulting in 23 amino acid substitutions (0-2.3%) aligned with T. gondii RH strain. Moreover, T. gondii strains representing the 3 classical genotypes (Type I, II, and III) were separated into different clusters based on the locus of MIC6 using phylogenetic analyses by Bayesian inference (BI), maximum parsimony (MP), and maximum likelihood (ML), but T. gondii strains belonging to ToxoDB #9 were separated into different clusters. Our results suggested that MIC6 gene is not a suitable marker for T. gondii population genetic studies.

• Journal of Periodontal and Implant Science
• /
• v.44 no.4
• /
• pp.201-206
• /
• 2014

Purpose: Aggressive periodontitis, especially in its severe form, was traditionally considered to have an unfavourable prognosis. It required a complex treatment and its stabilization was often achieved by surgical therapy. The aim of this study was to investigate the results of nonsurgical periodontal treatment in severe generalized forms of aggressive periodontitis. Methods: Patients with advanced generalized aggressive periodontitis were included in the study. Probing depth (PD) of pockets ${\geq}7mm$ and clinical attachment level (CAL) of sites with attachment loss ${\geq}5mm$ were measured at baseline before nonsurgical periodontal treatment, at re-evaluation, and after treatment. The following other parameters were recorded: resolution of inflammation and bone fill. We compared the baseline values with re-evaluation and posttreatment values using the Friedman test. The Wilcoxon test with the Bonferroni correction was used for both re-evaluation and posttreatment values. Results: Seven patients with 266 periodontal sites were examined. A significant difference was found between values, reported as medians with interquartile ranges, for PD at baseline (7.94 [7.33-8.19] mm) and both re-evaluation (4.33 [3.63-5.08] mm) and posttreatment (3.54 [3.33-4.11] mm) values (P=0.002). A significant difference was also found between values for CAL at baseline (9.02 [7.5-9.2] mm) and both re-evaluation (6.55 [6.30-6.87] mm) and posttreatment (6.45 [5.70-6.61] mm) (P=0.002). Inflammation was resolved and angular bone defects were repaired in all cases. Conclusions: These therapeutic results suggest that this form of periodontitis could have positive outcomes after nonsurgical periodontal treatment. The reparative potential of tissue affected by severe aggressive periodontitis should encourage clinicians to save apparently hopeless teeth in cases of this form of periodontitis.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.18 no.4
• /
• pp.363-368
• /
• 1985

Tagged and untagged sea urchins, Hemicentrotus pulcherrimus (A. Agassiz) were reared for 84 days in the laboratory, Vinyl tape and trapall paper were used as tag materials. The natural mortality, mortality by predation and shedding rate of tags of the tagged groups were examined, and the results were compared with those of untagged control group. The results of Chi-square test of natural mortality between tagged and control groups were very significative, however, the comparison between the two tagged groups was insignificative. No effect of tag attachment seems to be present at the point of natural predation by starfish, and $x^2-test$ between two the tagged groups on the loss rate of tags showed also insignificance. The mortality shortly after tagging seems to be negligible, and the distinct decreasing effect on growth due to tag attachment was not revealed because of insufficient individuals and rearing periods.

• Journal of the Society of Disaster Information
• /
• v.8 no.4
• /
• pp.391-400
• /
• 2012

Recently, the construction industry commonly uses FRP as a reinforcement material because of its material advantages. FRP attached reinforcement has various advantages such as high strength, stiffness, excellent durability and construction practicability comparing to its weight. However, external attachment of FRP is water-tighted with low water permeable material, not draining water, probably causing damages on a permanent structure. The study manufactured it through pultrusion and examined GP(glass fiber panel) of which material-mechanical properties are almost same as the existing FRP but durability and attachment performance are better by stationary experiments, testing load-deflection curve, destruction types and load-deflection relation under repetitive loading test. As a result of 2,000,000 fatigue tests, it did not result in the destruction and showed excellent permanent attachment and durability as it displays significantly low compressive strain of concrete.

• Parasites, Hosts and Diseases
• /
• v.56 no.1
• /
• pp.53-59
• /
• 2018

Tick saliva is critically important for continuous attachment to the host, blood feeding for days, and transmission of tick-borne pathogens. To characterize the patterns of inflammatory cytokine gene expression during its attachment and blood sucking time, peripheral blood samples of rabbits infested with Haemaphysalis longicornis ticks were collected at different intervals. Blood histamine concentration was evaluated as well as gene encoding IFN-${\gamma}$, TNF-${\alpha}$, IL-2, IL-6, IL-4, and IL-10 were compared with non-infested rabbits. Blood histamine concentration of tick-infested rabbits during fast feeding time was significantly higher than that of non-infested rabbits. In both nymph and adult tick infested rabbits, expression of TNF-${\alpha}$ and IFN-${\gamma}$ genes were decreased significantly (P<0.05), while expression of IL-4, IL-6, and IL-10 were increased 1.3 to 7 folds in adult infested rabbits with the exception of IL-6 that was significantly (P<0.05) decreased in nymph infested rabbits. IL-2 was not expressed in either nymph or adult infestation. H. longicornis saliva is capable of modulate host responses through a complex correlation with histamine and Th1, Th2 mediated cytokines that suppress the inflammatory responses directed toward inflammatory mediators introduced into the host during tick feeding.

• The Journal of Advanced Prosthodontics
• /
• v.3 no.1
• /
• pp.47-50
• /
• 2011

Despite the greater retention and low maintenance of bar attachment system, the longer clinical time and increased number of visits were the assignments to overcome in bar attachment system. This case report describes SFI-Bar$^{(R)}$ (Cendres et Me$\'{e}$taux, Biel/Bienne, Switzerland) to be solve those problems. A 65-year-old female, who had severely absorbed mandible, hoped to wear a stable mandibular denture without pain. As soon as two implants were placed on mandible, a tube bar was connected to two adaptors connected to each implant. The length of the tube bar was adjusted considering inter implant distance, and reconnected to the adaptors. Finally a female part was seated beneath the denture. This case report showed that a satisfactory clinical result was achieved by delivering bar overdenture immediately after implant placement without laboratory procedure.