• The korean journal of orthodontics
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• v.28 no.1 s.66
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• pp.165-174
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• 1998

The turnover of collagen is controlled by the balance between collagen synthesis and degradation. The production of collagenase (matrix metalloproteinase-1) and its inhibitor, tissue inhibitor of matrix metallopmteinase-1 (TIMP-1) are one of the substances which regulate this balance. The periodontal ligament fibroblast plays an important role in collagen metabolism during orthodontic treatment and is believed to be an origin of the osteoblast in the alveolar bone. The collagenase secreted by the periodontal ligament fibroblast and the osteoblast initiates the bone resorption by removing the osteoid layer in the alveloar bone. The interleukin-$1{\beta}$ is secreted by the macrophage during orthodontic treatment. The present study was undertaken to assess the effect of mechanical stress and interleukin-$1{\beta}$ on the expression of collagenase and TIMP-1 in the periodontal ligament fibroblasts using reverse transcription polymerase chain reaction and immunohistochemical staining. The periodontal ligament fibroblasts were stitched by placing the $Petriperm dish^{\circledR}$ dish on the top of spheroidal convex watch glass ($5\%$ surface increase) and tented with interleukin-$1{\beta}$ (1.0 ng/ml), or treated with both of them. Treatment with mechanical stress and/or interleukin-$1{\beta}$ resulted in increased collagenase mRNA expression. The mechanical stress treated group (1.61, 1.62, 1.37 fold increase), the interleukin-$1{\beta}$, tented group (1.68, 1.60, 3.78 fold increase), the mechanical stress and interleukin-$1{\beta}$ treated group (1.89, 1.72, 5.48 fold increase) induced increases in collagenase mRNA compared with the control group after 2, 4, 8 hours respectively. But TIMP-1 mRNA expressions at experimental groups were decreased after 2, 4 hours and increased after 8 hours. The mechanical stress treated group (0.16, 0.49 fold decrease and 3.77 fold increase), the interleukin-$1{\beta}$ treated group (0.15,0.44 fold decrease and 4.46 fold increase), the mechanical stress and interleukin-$1{\beta}$ tented group (0.15, 0.69 fold decrease and 4.81 fold increase) induced changes in TIMP-1 mRNA compared with the control group after 2, 4, 8 hours, respectively. Immunohistochemical stain showed that increased collagenase and TIMP-1 staining of the mechanical stress tented group, the interleukin-$1{\beta}$ treated group, and the mechanical stress and interleukin-$1{\beta}$ treated group compared with that of the control group after 8 hours. These findings suggest that mechanical stress and interleukin-$1{\beta}$ regulate expression of collagenase and TIMP-1.

• Korean Journal of Clinical Pharmacy
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• v.16 no.2
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• pp.86-91
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• 2006

There are 3 different hypotheses on how statins may affect bones, through promoting bone formation, inhibiting bone resorption or through anti-inflammatory effect. In the 3 cross-sectional studies above, one showed increase BMD at hip and spine, one showed increase BMD only at mid-forearm and one showed that the risk reduction in fractures is not explained by the changes in BMD however, all 3 studies showed a decrease in risk of fracture associated with statins. In the 2 prospective cohort studies, one showed the use of statins was not associated with BMD at any skeletal site or decreasing the risk of fracture, and the other showed statins except pravastatin decreased in risk of vertebrate fracture but not affecting lumbar spine BMD. All of case-control studies indicated reduction in fracture risk but did not provide any data regarding BMD. 2 of the randomized, controlled studies showed no significant reduction in fracture risk as well as statins' effects on BMD. Finally, one longitudinal study showed statin use reduced fracture risk and increased BMD. Among the conflicting results shown above, even when statin use was shown to increase BMD, it does not seem to account for the reduction in fracture risk. There may be different ways that statins affect bone other than those hypotheses proposed above. Many studies seem to agree that pravastatin does not have any effect on bone. Some studies suggested that the reason statins did not achieve clinically significant increases in BMD in some studies, is due to the low affinity of statins on bone; statins are designed to act in the liver therefore their effective concentration in extrahepatic tissue is low. The limitations to those studies discussed above. Many studies did not account for the change of lifestyle while subjects' were on statins. Increases in weight bearing exercise and changes in diet might affect BMD and thus reduce risk of fractures. Mental alertness and vision acuity might prevent falls from occurring; many statin-users in the studies were young so the risk of fractures from falls would be decreased. Almost all of the studies failed exclude patients with neurological problems. During study periods, many subjects may have been started on drugs for diseases that usually occur with aging which could cause drowsiness and lead to falls. The sample sizes used in some of the trials were small and the duration of treatment and follow up might not have been long enough to see clinically relevant results.

• Journal of Periodontal and Implant Science
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• v.26 no.3
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• pp.605-624
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• 1996

Various bonegraft materials and the technique of guided tissue regeneration have been used to regenerate lost periodontal tissue. Calcium sulfate has been known as a bone graft material because of good biocompatibility, rapid resorption and effective osteoinduction. It has been known that calcium sulfate works as a binder to stabilize the defect when it is used with synthetic graft materials. The effects on the regeneration of pericxiontal tissue were studied in dogs after grafting 3-wall intrabony defects with calcium carbonate and calcium sulfate and covering with calcium sulfate barrier. The 3-wall intrabony defectstdmm width, 4mm depth, 4mm length) were created in anterior area and treated with flap operation alone(contol group), with porous resorbable calcium carbonate graft alonetexperirnental group 1), with calcium sulfate graft alonetexperimental group 2) and with composite graft of 80% calcium carbonate and 20% calcium sulfate with calcium sulfate barriertexperimental group 3). Healing responses were histologically observed after 8 weeks and the results were as follows: 1. The alveolar bone formation was $0.59{\pm}0.19mm$ in the control group, $1.80{\pm}0.25mm$ in experimental group 1, $1.61{\pm}0.21mm$ in experimental group 2 and $1.94{\pm}0.11mm$ in experimental group 3 with statistically significant differences between control group and all experimental groups(P<0.05). There were statistically significant differences between experimental group 1 and group 2 (P<0.05). 2. The new cementum formation was $0.48{\pm}0.19mm$ in the control group. $1.72{\pm}0.26mm$ in experimental group 1, $1.43{\pm}0.17mm$ in experimental group 2, $1.89{\pm}0.15mm$ in experimental group 3 with statiscally significant differences between control group and all experimental groups (p<0.05). There were statistically significant differences between experimental group 1 and group 2, and between experimental group 2 and group 3(P<0.05). 3. The length of junctional epithelium was $1.61{\pm}0.20mm$ in the contol group, $0.95{\pm}0.06mm$ in experimental group 1, $1.34{\pm}0.16mm$ in experimental group 2, $1.08{\pm}0.11mm$ in experimental group 3 with statiscally significant differences between control group and experimental group 1. and btween control group and experimental group 3(p<0.05). There were statistically significant differences between experimental group 1 ,and group 2, and between experimental group 2 and group 3(P<0.05). 4. The connective tissue adhesion was $1.67{\pm}O.20mm$ in the control group, $1.33{\pm}0.24mm$ in experimental group 1. $1.23{\pm}0.16mm$ in experimental group 2, $1.08{\pm}0.14mm$ in experimental group 3 with statistically significant differences between control group and all experimental groups(p<0.05). There were nostatistically significant differences between all experimental groups. As a result, epithelial migration was not prevented when calcium sulfate was used alone, but new bone and cementum formation were enhanced. Epithelial migration was prevented and new bone and cementum formation were also enhanced when calcium carbonate was used alone and when both calcium carbonate and calcium sulfate were used.

• Journal of Periodontal and Implant Science
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• v.26 no.3
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• pp.641-654
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• 1996

In infectious disease, invasion of host tissue by bacteria or their products frequently induces a wide variety of inflammatory and immunopathologic reaction. Evidence indicates that cytokines are involved in the initiation and progression of chronic inflammatory diseases, such as periodontitis. Interleukin-6, which is a multifunctional cytokine, has important roles in acute and chronic inflammation and may also be implicated in bone resorption. Periodontal diseases are characterized by chronic inflammation of the periodontium with alveolar bone resoption. A principal driving force behind this response appears to lie in the immune system's response to bacteria. Many of the cell components which have been shown to function as virulence factors in gram-negative bacteria are associated with the bacterial surface. Of these, lipopolysaccharide has been characterized as one that mediates a number of biological activities which can lead to the destruction of host tissue. Non-steroidal antiinflammatory drug is used for reduce inflammation, and most of NSAIDs inhibit prostaglandine $E_2$ production, but it is shown that $PGE_2$ production is stimulated by IL-1 in recent study. So, the influence of other cytokines except $PGE_2$ on periodontium can not be avoided. Therefore, new antiinflammatory drug is needed. Rhizoma coptidis is used in oriental medicine for anti-inflammation and antiseptics. In this present study, we examined the IL-6 release in periodontal ligament cells treated with the lipopolysaccharide, and also the effect of rhizoma coptidis on cellular activity and IL-6 production of periodontal ligament cells. To evaluate the effect of rhizoma coptidis on cellular activity, the cells were seeded at a cell density of $1{\times}10^4$ cells/well in 24-well culture plates. After one day incubation, 1-6, 10-9 and 10-12 g/ml of rhizoma coptidis and 5, $10{\mu}g/ml$ of LPS were added to the each well and incubated for 1 and 2 days, respectively. Then, MTT assay were carried out. To evaluate the effect of rhizoma coptidis on IL-6 production, the cells were seeded at a cell density of $1.5{\times}10^4$ cells/well in 24-well culture plates. After one day incubation, 10-9 g/ml of rhizoma coptidis and 5, $10{\mu}g/ml$ of LPS were added to the each well and incubated for 3, 6, 12 and 24 hours. Then, amounts of IL-6 production is measured by IL-6 ELISA kit used. The results were as follows : 1. Rhizoma coptidisrbelow to ($10^{-6}g/ml$) significantly increaed cellular activity of periodontal ligament cells than control. 2. Rhizoma coptidist ($10^{-9}g/ml$) significantly increased cellular activity of LPS($5{\mu}g/ml$)-treated periodontal ligament cells than control. 3. LPS(5 and $10{\mu}g/ml$) significantly increased IL-6 production of periodontal ligament cells than control. 4. Rhizoma coptidis($10^{-9}g/ml$) decreased IL-6 production of LPS ($5{\mu}g/ml$)-treated periodontal.ligarnent cells than LPS only tested group. These findings suggest that stimulation of the IL-6 release of periodontal ligament cells by LPS may have a role in the progression of inflammation and alveolar bone resoption in periodontal disease, and that inhibition of the IL-6 release of cells and stimulation of cellular activity by rhizoma coptidis may help the periodontal regeneration.

• The korean journal of orthodontics
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• v.29 no.3 s.74
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• pp.361-374
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• 1999

Intraoral filled type of orthodontic appliance can cause reversible or irreversible damages such as gingivitis, periodontitis, enamel decalcification, dental caries, root resorption, and pulpal changes. Such adverse effects are brought by increase in dental plaque as well as oral flora. Such an increase causes gingival inflammation and enamel decalcification. The purpose of this study is to get klowledge on initial changes in dental plaque, gingivitis, and enamel decalcification after bonding fixed orthodontic appliances according to time flow, gender, and sides(right/left) of premolar region. For control group, 48 students of dental college, Yonsei university(26 males, 22 females) were chosen; for experimental group, 73 orthodontic patients(36 males, 37 females) who will be treated with fixed appliances were chosen. All the subjects had no systemic disease, juvenile periodontitis and all the females had passed their ,menarche. Tooth brushing instruction was given to all the subjects prior to the experiment. For control group, plaque index, gingival index, and decalcification index were measured twice at 3 weeks interval ; for experimental group, the same was done prior to, 3, 6, 9 weeks after bonding fixed appliances. The following results were obtained: 1. In plaque index 3 weeks after placement of appliances, and it showed gradual increase afterwards. 2. In gingival index3 weeks after placement of appliances, and afterwards it showed increase at a faster rate than plaque index. 3. Enamel decalcification began to show between 3 and 6 weeks after bonding fixed appliances. Decalcification index began to increase 6 weeks after appliance placement, but there was no statistical significance. 4. When the comparison was made between two sides of premolar region, the right side showed greater index in plaque and gingival index of experimental group.

• Journal of the Korean Society of Food Science and Nutrition
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• v.37 no.12
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• pp.1560-1567
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• 2008

This study was designed to evaluate the effect of green tea products (GTP) on bone metabolism marker in ovariectomized (OVX) rats fed high cholesterol diet. Forty Sprague-Dawley female rats, 10 weeks of age ($279{\pm}2g$), were divided into 4 groups and fed on the experimental diets for 6 weeks: sham operated control (Sham-C) and OVX-control (OVX-C) groups treated high cholesterol diet. OVX-GTP 5% (OVX-G5) and OVX-GTP 20% (OVX-G20) groups were treated with high cholesterol diet containing 5% GTP and 20% GTP, respectively. Food efficient ratio was significantly (p<0.05) lower in OVX-G20 than in the other OVX groups. Bone mineral density of femur was not significantly different among the experimental groups in the order of Sham-C>OVX-G5 and OVX-G20>OVX-C. Alkaline phosphatase activities on serum was lower in the GTP supplement groups than in the OVX-C. Estradiol levels of serum were higher in the GTP supplement groups than in the OVX-C. Osteocalcin levels of serum was the lowest in the OVX-G20. Deoxypyridinoline crosslink values of urine, indicator of bone absorption, was the lowest in the OVX-G20 group. The GTP supplemented groups had a lower bone resorption ratio than in the OVX-C group. From the above results, these findings suggest the possibility of using GTP as a functional food materials related to bone metabolism in menopause.

• The Journal of the Korean bone and joint tumor society
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• v.15 no.2
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• pp.111-121
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• 2009

Background: Osteosarcoma is one of the most common primary malignant tumors of bone occurring mainly in children and adolescents. Although surgery combined with chemotherapy has markedly improved patient survival during the last years, the use of anticancer drugs is still associated with serious problem, such as the frequent acquisition of drug-resistant phenotypes and occurrence of "secondary malignancies". Several solid tumors display enhanced expression of matrix metalloproteinases (MMPs), and recently clinical trials have been initiated on MMP-inhibitors. On the other hand, bisphosphonates (BPs) are inhibitors of bone resorption, and widely used to treat osteoclast-mediated bone diseases. Also they appear to possess direct antitumor activity. Methods: One osteosarcoma cell line (U2OS) was treated with ibandronate (0, 0.1, 1, $10{\mu}M$) for 48 hours. Cell viabilities were determined using MTT assay, the mRNA levels of MMP-2 and MT1-MMP were detected by reverse-transcription polymerase chain reaction, the amount of MMP-2 and MT1-MMP protein were measured by Westernblot, the activities of MMP-2 were observed by Gelatin zymography, and Matrigel invasion assays were used to investigate the invasive potential of osteosarcoma cell lines before and after ibandronate treatment. Results: The invasiveness of U2OS cell line was reduced dose-dependently following 48 hour treatment of up to $10{\mu}M$ of the ibandronate at which concentration no cytotoxicity occurred. Furthermore, the gelatinolytic activities and protein and mRNA levels of MMP-2 and MT1-MMP were also suppressed by increasing ibandronate concentrations. Conclusion: Given that MMP-2 is instrumental in tumor cell invasion, it is very likely that the reduction in osteosarcoma cell invasion by ibandronate is a consequence, at least in part, of suppressed expression of both MMP-2 and MT1-MMP. Isolation of a molecule (s) responsible for the bisphosphonate inhibition of tumor cell invasion would pave the way for the development of a new generation of metastasis inhibitors.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.30 no.6
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• pp.465-473
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• 2004

Purpose : The essential triad for nerve regeneration is nerve conduit, supporting cell and neurotrophic factor. In order to improve the peripheral nerve regeneration, we used polyglycolic acid(PGA) tube and brain-derived neurotrophic factor(BDNF) gene transfected Schwann cells in sciatic nerve defects of SD rat. Materials and methods : Nerve conduits were made with PGA sheet and outer surface was coated with poly(lactic-co-glycolic acid) for mechanical strength and control the resorption rate. The diameter of conduit was 1.8mm and the length was 17mm Schwann cells were harvested from dorsal root ganglion(DRG) of SD rat aged 1 day. Schwann cells were cultured on the PGA sheet to test the biocompatibility adhesion of Schwann cell. Human BDNF gene was obtained from cDNA library and amplified using PCR. BDNF gene was inserted into E1 deleted region of adenovirus shuttle vector, pAACCMVpARS. BDNF-adenovirus was multiplied in 293 cells and purified. The BDNF-Adenovirus was then infected to the cultured Schwann cells. Left sciatic nerve of SD rat (250g weighing) was exposed and 14mm defects were made. After bridging the defect with PGA conduit, culture medium(MEM), Schwann cells or BDNF-Adenovirus infected Schwann cells were injected into the lumen of conduit, respectively. 12 weeks after operation, gait analysis for sciatic function index, electrophysiology and histomorphometry was performed. Results : Cultured Schwann cells were well adhered to PGA sheet. Sciatic index of BDNF transfected group was $-53.66{\pm}13.43$ which was the best among three groups. The threshold of compound action potential was between 800 to $1000{\mu}A$ in experimental groups which is about 10 times higher than normal sciatic nerve. Conduction velocity and peak voltage of action potential of BDNF group was the highest among experimental groups. The myelin thickness and axonal density of BDNF group was significantly greater than the other groups. Conclusion : BDNF gene transfected Schwann cells could regenerate the sciatic nerve gap(14mm) of rat successfully.

• The Korean Journal of Pesticide Science
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• v.11 no.4
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• pp.254-260
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• 2007

In order to evaluate the toxic effects of butachlor, a herbicide widely used for control of weeds in paddy field, on medaka (Oryzias latipes), acute toxicity tests for five developmental stages and early life stage toxicity test of were conducted. As the results of acute toxicity test, $96h-LC_{50}s$ for 1 day, 1 week, 2 weeks, 2 months and 5 months after hatching of O. latipes were 0.68, 0.52, 0.38, 1.09 and $0.45\;mg\;L^{-1}$, respectively. This indicated that the most sensitive stage was 2 weeks after hatching. The early life stage toxicity test showed that no statistically significant hatching period and hatching success of embryo was observed at all concentrations of butaclor. However, 0.05 and $0.1\;mg\;L^{-1}$ of butachlor showed statistically significant post hatching survival with p<0.1. Abnormalities of larva were 2.1, 2.3 and 10% at 0.025, 0.05 and $0.1\;mg\;L^{-1}$ of concentration, respectively. They showed abnormal vertebral axis, craniofacial alteration and retarded yolk-sac resorption. The total length and weight were decreased depending on butachlor concentration the end of test. Weight of larva was showed more sensitive toxic indicator than total length. The toxicological responses of O. latipes to butachlor expressed as LOEC(lowest observed effect concentration), NOEC(no observed effect concentration) and MATC(maximum acceptable toxicant concentration) values were 0.025, 0.013 and $0.018\;mg\;L^{-1}$, respectively.

• Korean Journal of Psychosomatic Medicine
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• v.5 no.2
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• pp.185-194
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• 1997

A comparison was made regarding illness behavior among patients with somatoform disorders, depressive disorders and psychosomatic disorders. The subjects consisted of out-patients with somatoform disorders(N=52), depressive disorders(N=52) and psychosomatic disorders(N=51). illness behavior was assessed by illness Behavior Assessment Schedule and the questionnaire about help-seeking behavior. The patients with somatoform disorders and psychosomatic disorders more often affirmed the presence of somatic disease, were more likely to have phobia of disease, had more preoccupation with ideas of disease and more frequently shopped around oriental clinics than the patients with depressive disorders. The patients with somatoform disorders more often attributed its cause to physical factors, less often attributed the origin of affective disturbance to psychological causes, showed Less depression and irritability, and were less likely to accept psychiatric treatment recommended by other physicians than depressive patients. The patients with somatoform disorders were more likely to report having been told that they suffered from a mild illness than those with psychosomatic disorders. The patients with somatoform disorders with psychological problems tended to inhibit expression of their emotion. Female patients with somatoform disorders more often affirmed the presence of psychological disorder and attributed its cause to psychological factors than male ones. These results suggest that in illness behavior, patients with somatoform disorders are different from depressive patients, whereas the former patients are similar to psychosomatic patients except the discrepancy between therapists and patients regarding evaluation of their symptoms. Thus, it is emphasized that first, therapists need to approach patients with somatoform disorders somatically with understanding of their underlying need to deny psychological problems, followed by either psychological or biopsychosocial approach.