• Journal of Periodontal and Implant Science
• /
• v.37 no.2
• /
• pp.165-180
• /
• 2007

Dental Implants have been proved to be successful prosthetic modality in edentulous patients for 10 years. However, there are few reports on the survival of implant according to location in molar regions. The purpose of this study was to evaluate the $4{\sim}5$ years' cumulative survival rate and the cause of failure of dental implants in different locations for maxillary and mandibular molars. Among the implants placed in molar regions in Gwangju Mir Dental Hospital from Jan. 2001 to Jun. 2002, 473 implants from 166 patients(age range; $26{\sim}75$) were followed and evaluated retrospectively for the causes of failure. We included 417 implants in 126 periodontally compromised patients, 56 implants in 40 periodontal healthy patients, and 205 maxillary and 268 mandibular molar implants. Implant survival rates by various subject factors, surgical factors, fixture factors, and prosthetic factors at each location were compared using Chi-square test and Kaplan-Meier cumulative survival analysis was done for follow-up(FU) periods. The overall failure rate at 5 years was 1O.2%(subject level) and 5.5%(implant level). The overall survival rates of implants during the FU periods were 94.5% with 91.3% in maxillary first molar, 91.1% in maxillary second molar, 99.2% in mandibular first molar and 94,8% in mandibular second molar regions. The survival rates differed significantly between both jaws and among different implant locations(p<0.05), whereas the survival rates of functionally loaded implants were similar in different locations. The survival rates were not different according to gender, age, previous periodontal status, surgery stage, bone graft type, or the prosthetic type. The overall survival rate was low in dental implant of too wide diameter(${\geq}5.75$ mm) and the survival rate was significantly lower for wider implant diameter(p

• Molecules and Cells
• /
• v.43 no.3
• /
• pp.228-235
• /
• 2020

The Drosophila transmembrane semaphorin Sema-1a mediates forward and reverse signaling that plays an essential role in motor and central nervous system (CNS) axon pathfinding during embryonic neural development. Previous immunohistochemical analysis revealed that Sema-1a is expressed on most commissural and longitudinal axons in the CNS and five motor nerve branches in the peripheral nervous system (PNS). However, Sema-1a-mediated axon guidance function contributes significantly to both intersegmental nerve b (ISNb) and segmental nerve a (SNa), and slightly to ISNd and SNc, but not to ISN motor axon pathfinding. Here, we uncover three cis-regulatory elements (CREs), R34A03, R32H10, and R33F06, that robustly drove reporter expression in a large subset of neurons in the CNS. In the transgenic lines R34A03 and R32H10 reporter expression was consistently observed on both ISNb and SNa nerve branches, whereas in the line R33F06 reporter expression was irregularly detected on ISNb or SNa nerve branches in small subsets of abdominal hemisegments. Through complementation test with a Sema-1a loss-of-function allele, we found that neuronal expression of Sema-1a driven by each of R34A03 and R32H10 restores robustly the CNS and PNS motor axon guidance defects observed in Sema-1a homozygous mutants. However, when wild-type Sema-1a is expressed by R33F06 in Sema-1a mutants, the Sema-1a PNS axon guidance phenotypes are partially rescued while the Sema-1a CNS axon guidance defects are completely rescued. These results suggest that in a redundant manner, the CREs, R34A03, R32H10, and R33F06 govern the Sema-1a expression required for the axon guidance function of Sema-1a during embryonic neural development.

• Journal of Periodontal and Implant Science
• /
• v.49 no.1
• /
• pp.2-13
• /
• 2019

Purpose: The aim of this study was to conduct a histologic evaluation of irradiated calvarial defects in rats 4 weeks after applying fibroblast growth factor-2 (FGF-2) with hyaluronan or biphasic calcium phosphate (BCP) block in the presence or absence of adjunctive hyperbaric oxygen (HBO) therapy. Methods: Twenty rats were divided into HBO and non-HBO (NHBO) groups, each of which was divided into FGF-2 and BCP-block subgroups according to the grafted material. Localized radiation with a single 12-Gy dose was applied to the calvaria of rats to simulate radiotherapy. Four weeks after applying this radiation, 2 symmetrical circular defects with a diameter of 6 mm were created in the parietal bones of each animal. The right-side defect was filled with the materials mentioned above and the left-side defect was not filled (as a control). All defects were covered with a resorbable barrier membrane. During 4 weeks of healing, 1 hour of HBO therapy was applied to the rats in the HBO groups 5 times a week. The rats were then killed, and the calvarial specimens were harvested for radiographic and histologic analyses. Results: New bone formation was greatest in the FGF-2 subgroup, and improvement was not found in the BCP subgroup. HBO seemed to have a minimal effect on new bone formation. There was tendency for more angiogenesis in the HBO groups than the NHBO groups, but the group with HBO and FGF-2 did not show significantly better outcomes than the HBO-only group or the NHBO group with FGF-2. Conclusions: HBO exerted beneficial effects on angiogenesis in calvarial defects of irradiated rats over a 4-week healing period, but it appeared to have minimal effects on bone regeneration. FGF-2 seemed to enhance new bone formation and angiogenesis, but its efficacy appeared to be reduced when HBO was applied.

• Journal of the korean academy of Pediatric Dentistry
• /
• v.49 no.2
• /
• pp.170-179
• /
• 2022

This study aimed to evaluate the masticatory performance of Korean children and adolescents and to investigate related factors. Early loss of primary molars, degree of occlusion of first molars, occlusal relationship of first molars, and presence of anterior crossbite were considered. From March 2020 to July 2021, 56 children and adolescents between the ages of 6 and 12 were included. The mixing ability index (MAI) was calculated to evaluate the masticatory efficiency of children and adolescents. The subjects were classified into three groups according to the number of early lost primary molars; normal dentition, 1 - 2 teeth lost, more than 3 teeth lost. The number of participants are 23, 18, and 15, respectively. There was no difference in the MAI values between the normal dentition group and the group has 1 - 2 teeth lost. However, when 3 or more primary molars were lost, the MAI value decreased and a significant difference was observed. This study is the first study to evaluate the masticatory performance of children and adolescents in Korea, and it will be helpful to pediatric dentists who evaluate the masticatory performance of children and adolescents and strive to improve the masticatory efficiency of children and adolescents in clinical practice.

• Journal of Nutrition and Health
• /
• v.56 no.2
• /
• pp.184-202
• /
• 2023

Purpose: This study investigates the necessary educational materials from the perspective of caregivers managing food allergies of preschoolers. Methods: An online survey enrolled 400 caregivers of preschoolers with food allergies. The study was conducted in July 2022, and data were analyzed using the IBM SPSS Statistics 25. Results: The caregivers of preschoolers with food allergies showed low food allergy knowledge. The highest percentage of incorrect answers were for items related to the cause (74.2%) and response (65.2%) to food allergies. Moreover, categorizing the levels of knowledge as high, medium, and low, we found that caregivers with younger children exhibited a better understanding of food allergies. Approximately 56.9% of subjects in the high class were caregivers with preschoolers under three years, whereas caregivers with preschoolers over four years comprised 43.2% of the high-class subjects. Regarding food allergy treatment, four questions measured how well the caregivers tended to the children. With higher levels of knowledge, caregivers were more likely to read nutrient information and check for food allergens. The caregivers of preschoolers who were clinically diagnosed with food allergies demonstrated a higher percentage of using separate ingredients and cooking utensils. Conclusion: This study shows how the caregivers' knowledge levels are critical in managing and treating food allergies among preschoolers. With caregivers' lower knowledge of food allergies and preschoolers younger than four years, self-diagnosis of food allergies and existing food allergies were not managed efficiently. Hence, customized education for caregivers is essential to improve their knowledge level regarding limiting foods that may cause allergies, reading food labels, and using ingredients and cooking utensils separately.

• Journal of the Korean Geotechnical Society
• /
• v.23 no.3
• /
• pp.25-40
• /
• 2007

Excessive earth pressure is one of the major mechanical factors in the deformation and damage of Cut-and-Cover Tunnel lining in shallow tunnels and portals of mountain tunnels (Kim, 2000). Excessive earth pressure may be attributed to insufficient compaction and consolidation of backfill material due to self-weight, precipitation and vibration caused by traffic (Komiya et al., 2000; Taylor et al., 1984; Yoo, 1997). Even though there were a lot of tests performed to determine the earth pressure acting on the tunnel lining, unfortunately there were almost no case histories of studies performed to determine remedial measures that reduce differential settlement and excessive earth pressure. In this study the installation of geotextile mat was selected to reduce the differential settlement and excessive earth pressure acting on the cut-and-cover tunnel lining. In order to determine settlement and earth pressure reduction effect (reinforcement effect) of geotextile mat reinforcement, laboratory tunnel model tests were performed. This study was limited to the modeling of rigid circular cut-and-cover tunnel constructed at a depth of $1.0D\sim1.5D$ in loose sandy ground and subjected to a vibration frequency of 100 Hz. Model tests with varying soil cover, mat reinforcement scheme and slope roughness were performed to determine the most effective mat reinforcement scheme. Slope roughness was adjusted by attaching sandpaper #100, #400 and acetate on the cut slope surface. Mat reinforcement effect of each mat reinforcement scheme were presented by the comparison of earth pressure obtained from the unreinforced and mat reinforced model tests. Soil settlement reduction was analyzed and presented using the Picture Analysis Method (Park, 2003).

• Journal of Life Science
• /
• v.18 no.11
• /
• pp.1592-1599
• /
• 2008

The $\beta$-lactamase gene was cloned into E. coli DH5$\alpha$ from Bacillus sp. J105 with strong resistance against $\beta$-lactam antibiotics. The chromosomal DNA was partially digested with Sau3AI and ligated to BamHI digested pLAFR3. $\beta$-Lactamase positive clones were obtained by using in vitro packaging kit. The pKL11-${\Delta}4.6$ with $\beta$-lactamase activity was obtained by subcloning of the recombinant plasmid ($\beta$-lac +). The 6.5 kb fragment in the subcloned plasmid was sequenced. The DNA fragment that contains the $\beta$-lactamase gene encodes 309 amino acids. The 0.17 kb upstream region was similar to those of B. thuringinesis and B. cereus with 97% identity. The deduced amino acids sequence was also similar to those of $\beta$-lactamase from B. thuringinesis and B. cereus with 97% and 94% identity, respectively. The phylogenetic tree also showed the relationships of the $\beta$-lactamase gene of Bacillus sp. J105 to genetically related that of other Bacillus strains. Analysis of expression pattern of the pKL11-${\Delta}4.6$ in E. coli, revealed that the secretion efficiency of $\beta$-lactamase was $4{\sim}5%$ and the molecular weight was as same as that of original $\beta$-lactamase (31 kDa) from Bacillus sp. J105.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.45 no.11
• /
• pp.1544-1551
• /
• 2016

Various types of fermented soybean foods are consumed in various Asian countries, including China, Indonesia, Japan, Korea, and Vietnam. Cheonggukjang is a Korean whole soybean paste fermented by Bacillus subtilis and regarded as a healthy food. The objective of this study was to investigate the Ca-bioavailability and anti-osteoporotic effects of cheonggukjang (CGJ) containing high poly-gamma glutamate (PGA) contents in an animal model. Blood samples were collected from the jugular vein at 0, 0.5, 1, 2, 3, 4, and 5 h after a single oral dose in male rats. Ca-bioavailability in CGJ containing high PGA contents was approximately 3~5 times higher than that of natural CGJ. Female rats were either sham-operated (sham; n=5) or surgically ovariectomized (OVX; five animals per group) and then administered to OVX control, raloxifene hydrochloride (RLX) 1 mg/kg/d, or CGJ containing high contents of PGA (20 and 200 mg/kg/d) for 12 weeks. Serum osteocalcin concentration was significantly lower in the CGJ 200 mg/kg/d group compared with the OVX control group. Serum progesterone concentration was significantly higher in the CGJ 200 mg/kg/d group compared with the OVX control group. Reduction grade of the trabecular bone decreased in the RLX 1 and CGJ 200 mg/kg/d group compared with that of the OVX control group. In conclusion, CGJ 200 mg/kg/d may have inhibitory effects on osteoporosis in OVX rats, and Ca-bioavailability was improved in CGJ containing high PGA contents.