• Journal of the Korean Society for Precision Engineering
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• v.27 no.5
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• pp.92-101
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• 2010

This study evaluated the structure and quality of osteoporotic vertebral bone. To induce osteoporosis, eight rats were ovariectomized (OVX). All rats were divided into two groups (Normal group: 4, OVX group: 4). Total lumbar vertebrae for each rat were scanned by in-vivo ${\mu}CT$ at 0, 4 and 8 weeks. Morphological characteristics (BV/TV, Tb.Th, Tb.N, Tb.Sp and SMI) were calculated by in-vivo ${\mu}CT$ image analyzer. Three dimensional finite element models were analyzed to investigate bone strength of OVX and Normal groups. Moreover, the elastic modulus was quantitatively analyzed to evaluate the quality changes of osteoporotic bone. In the OVX group, BV/TV, Tb.Th and Tb.N were significantly decreased at all the lumbar over time (p<0.05). We also investigated a contrary tendency in Tb.Sp and SMI, compared to the above results in each group. A degree of alteration of mechanical characteristics in OVX group was decreased over measuring time (p<0.05). Bone quality presented by distribution of elastic modulus was improved in the Normal group more than OVX group. The findings of the present study indicated that both bone structure and quality of whole lumbar could be tracked and detected by analyzing the morphological and biomechanical characteristics of bones, based on a nondestructive method.

• Journal of the korean academy of Pediatric Dentistry
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• v.29 no.2
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• pp.237-242
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• 2002

Lowe syndrome, also known as oculocerebrorenal syndrome, is a rare genetic disorder involving eyes, kidney and nervous system, and occurs predominantly in mostly males. The patients with Lowe syndrome are characterized with prominent forehead, thin and sparse hair, protruding ears, congenital cataracts, glaucoma, mental retardation, stunted growth, hypotonia, decrease in muscle mass and tendon reflexes, renal tubular dysfunction, and metabolic bone disease. A 6-year-old boy with Lowe syndrome was admitted to our clinic, with multiple caries and a chief complaint of intermittent pain on the left mandibular molar area. Because of difficulty in management of behavior and his medical problem, general anesthesia was performed for dental care. No specific complication was noticed during dental treatment procedure under general anesthesia and also during periodic recall-checks. General anesthesia itself, however, could be a potentially life-threatening procedure due to patient's biomedical problems. When a dental procedure under general anesthesia is to be required in patient with Lowe syndrome, it may be advisable being teamed with physicians, and general anesthesia duration should be as short as possible.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.9 no.3
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• pp.209-213
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• 1976

Spinous loaches widely distributed in Korea, are of many color pattern types, but interestingly the crossband B and C-types of these coaches are collected only in the two rivers, the Yeongsan River and the Seomjin River, flowing through the south-western part of Korea. These two types have not only different color pattern, but also different geographical distribution: the B-type is found in the Yeongsan River and the C-typs, in the Seomjin River. But the both types have four common distinctive features, which easily distinguish them from other already known species of this genus: the B and C-types have the similar total length distribution, the same structure of lamina circularis and scales, and the black spots at the back of their opercula. These peculiarities may be explained by studing the history of these two rivers. The author considers that they are once rivers of the same origin located around the Noryeong and the Sobaeg Mountains, and then were eventually separated from each other as the water level or the crust of Korea peninsula changed. Thus, these two types, B and C, of spinous loaches should have been the same species living in the same river, but in the course of time, these two types have taken different color patterns since the separation of two rivers thus making them impossible to cross between these two populations.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.31 no.2
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• pp.116-126
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• 2009

The use of short implants has been accepted risky from biomechanical point of view. However, short implants appear to be a long term viable solution according to recent clinical reports. The purpose of this study was to investigate the effect of different diameter and length of implant size to the different type of bone on the load distribution pattern. Stress analysis was performed using 3-dimensional finite element analysis(3D-FEA). A three-dimensional linear elastic model was generated. All implants modeled were of the various diameter(${\phi}4.0$, 4.5, 5.0 and 6.0 mm) and varied in length, at 7.0, 8.5 and 10.0 mm. Each implant was modeled with a titanium abutment screw and abutment. The implants were seated in a supporting D2 and D4 bone structure consisting of cortical and cancellous bone. An amount of 100 N occlusal load of vertical and $30^{\circ}$ angle to axis of implant and to buccolingual plane were applied. As a result, the maximum equivalent stress of D2 and D4 bones has been concentrated upper region of cortical bone. As the width of implant is increased, the equivalent stress is decreased in cancellous bone and stress was more homogeneously distributed along the implants in all types of bone. The short implant of diameter 5.0mm, 6.0mm showed effective stress distribution in D2 and D4 bone. The oblique force of 100N generated more concentrated stress on the D2 cortical bone. Within the limitations of this study, the use of short implant may offer a predictable treatment method in the vertically restricted sites.

• Korean Journal of Ichthyology
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• v.23 no.2
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• pp.158-162
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• 2011

Growth and spawning ecology of Cobitis lutheri (Teleoste: Cobitidae) were investigated in the Samcheon Stream, Mangyeong River, Jeollabuk-do, Korea from 2005 to 2006. Age group of C. lutheri estimated from the total length indicated that the 40 ~ 60 mm group is 1 year old, the 60 ~ 80 mm group is 2 years old, and the 80 ~ 110mm group is 3 ${\leq}$ years old. The sex ratio (Male/Female) was 0.78, and the female was 20 ~ 30 mm larger than the male. Lamina circularis at the base of pectoral fins in the males as a secondary sexual character was created 12 months after hatching. A change of lateral coloration of males was observed from April to September. The spawning season was early to middle July with water temperatures of $24{\sim}26^{\circ}C$. The average number of eggs was $1,127{\pm}453$ with the egg diameter of $1.09{\pm}0.02$ mm.

• Journal of Life Science
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• v.16 no.7 s.80
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• pp.1207-1213
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• 2006

Tumor necrosis $factor-{\alpha}\;(TNF-{\alpha})$ has been implicated in skeletal diseases by promoting bone loss in inflammatory bone diseases. In the present study, we examined the effects of $TNF-{\alpha}$ on osteoblastic differentiation of human bone marrow-derived mesenchymal stem cells (hBMSCs). $TNF-{\alpha}$ dose-dependently promoted matrix mineralization of hBMSCs with a maximal stimulation at 2ng/ml. $TNF-{\alpha}$ increased expression of alkaline phosphatase, which plays a crucial role for the matrix deposition. The $TNF-{\alpha}-stimulated$ osteoblastic differentiation was not affected by $NF_kB$ inhibitors, BAY and SN50. However, a JNK-specific inhibitor, SP600125 completely abolished the $TNF-{\alpha}-stimulated$ matrix mineralization and expression of alkaline phosphatase. These results suggest that $TNF-{\alpha}$ enhances osteoblastic differentiation of hBMSCs through JNK-dependent pathway.

• The Journal of Korean Academy of Prosthodontics
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• v.59 no.3
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• pp.314-318
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• 2021

There are very few reports of the restoration of tooth loss using dental implants in patients with diffuse sclerosing osteomyelitis (DSO). Because the patients with DSO have unfavorable bone quality for osseointegration of dental implants, additional considerations such as surgical trauma, infection control, and an extended healing period are essential when placing dental implants. The purpose of this study is to report on the success of osseointegration of a dental implant in the patient with DSO.

• Korean Journal of Ichthyology
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• v.33 no.1
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• pp.15-21
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• 2021

The Nakdong nose loach, Koreocobitis naktongensis is an endangered freshwater fish endemic to Korea. The spawning behaviour of the K. naktongensis was observed after treating Ovaprim in laboratory aquarium from 20~27 April 2010. The behavioral patterns were categorized into three stages of pre-spawning, spawning and post-spawning behaviors. Before spawning K. naktongensis usually repeated taking a rest and swimming. On average, initial spawning activity started 11 to 12 hours later after injection with Ovaprim. During the spawning period, the number of spawning acts ranged from 1 to 18. The spawning ratio of female to male was 1 : 1. The male embraced the back of the female's dorsal fin with his lamina circularis. It looked like a complete circle at that time. After spawning, parental care was not observed. Individuals not participating in spawning have been observed to feed on some of the fertilized eggs.

• Journal of Dental Rehabilitation and Applied Science
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• v.27 no.1
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• pp.25-39
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• 2011

In animal studies, Magnesium (Mg) - incorporated oxidized implants showed significant enhancement of the bone response. This prospective clinical trial was performed to investigate the success rate, implant stability and marginal bone loss of Mg oxidized clinical implant. The experimental protocol was approved by Institutional Review Board of the Gangneung-Wonju National University Dental Hospital. Fifty healthy patients had partial edentulism were included in this study. Mg oxidized clinical implants (Implant M, Shinhung, Korea) were installed and restored with conventional protocol. The patients were recalled at 1, 3, 6 months after functional loading. Implant stability quotient (ISQ) was measured and periapical radiographic images were obtained. Amount of marginal bone loss was calculated with calibrated images from periapical radiographs. Repeated measured analysis of variance and post hoc Tukey test were used to compare the mean ISQ and bone level. A total of 101 implants were analyzed. The mean ISQ values increased continuously with time lapse from 68.4 at fixture installation to 71.5 at 6 months after loading. Implant stability was correlated with gender, fixture diameter, bone quality and implant sites. The mean marginal bone loss during 6 months after loading was 0.26 mm. There was no failed implant and six-month success rate was 100%. Within the limitations of this study, the six-month success rate of Mg oxidized implant was satisfactory. The implant stability and marginal bone level were excellent. However, further longer clinical studies will be needed to confirm the success of Mg oxidized clinical implant.

• Korean journal of food and cookery science
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• v.21 no.5
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• pp.725-732
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• 2005

This study attempted to investigate if the soy isoflavone, genistein, influences bone metabolism in ovariectomized, 4-week-old female Wister rats. All the rats were divided into sham (SH) and ovariectomized (OVX) groups consisting of OVX-17${\beta}$-estradiol($10\;{\mu}g/kg$ b.w.), OVX-1mg or 5 mg or 10mg of genistein/kg b.w. The rates were allowed ad libitum access to foods and water for 8 weeks. The Results showed that body weight had significantly increased in the OVX group compared to the SH group (p<0.05) and was not different among the OVX-GEN and OVX-ES groups and the OVX group. The liver and uterus weights in the OVX groups were slighter than those in SH group (p<0.05). The kidney weight in the OVX groups was decreased compared to in that in the SH group but was not significantly different among all OVX groups. Femoral length in the OVX groups was longer than in the SH group and was not different. Rats in the OVX groups had higher creatinine levels than those in the SH group and hydroxyproline level did not differ significantly among any of the groups. Serum ALP activity and Ca in bone, feces, urine and serum did not change among the groups. Bone mineral density (BMD) decreased in the OVX groups compared to the SH group and was slightly increased by feeding genistein (p>0.05). Breaking force and stiffness did not change by ovariectomy and feeding genistein. Hence, these results suggested that estrogen may affect bone mineralization in growing rats and that genistein be may involved in the prevention of bone loss. However, more studies are needed to identify the proper mechanism of genistein and bone formation.