• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.33 no.2
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• pp.124-130
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• 2007

In the present study, I investigated the effects of N-methyl-D-aspartate (NMDA), arachidonic acid (AA), and Nitric Oxide Synthase Inhibitor (NOSI), alone or in combination, on the proliferation of cultured primary normal human oral keratinocytes (NHOK). The purpose of this study was therefore the preliminary study for the examination of the interaction between these agents and NHOK in order to elucidate the mechanisms by which epithelial growth and regeneration are regulated. NHOK were obtained from gingival tissue of 20 individuals aged 20 to 29, and third passage (P3) cells were used for this study. The DNA synthesis was measured by the BrdU assay. Addition of low concentration of AA ($1{\mu}M$) and high concentration of AA with NMDA group (NMDA+AA $10{\mu}M$) made DNA synthesis rate increase significantly at the early stage. Adding NNA ($10{\mu}M$) affected DNA synthesis rate to increase significantly in 4 hours. At the early stage, DNA synthesis was significantly active in the NOS-I with NMDA groups than in the control and the NMDA-only group, while it didn't become statistically meaningful in 24 hours. AA $1{\mu}M$ and NNA $10{\mu}M$ may induce the proliferation of the NHOK independently and NOS-I may induce the proliferation of the NHOK with NMDA. These reactions might be related to the NMDA receptor in the cell and the change of the intracellular calcium ion concentration.

• Journal of Periodontal and Implant Science
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• v.28 no.1
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• pp.133-143
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• 1998

Diabetes mellitus is a systemic disease with profound effects on oral health and periodontal wound healing. Uncontrolled diabetes adversely affects surgical wound healing and is often associated with abnormal proliferation of fibroblasts. Human gingival fibroblasts and PDL cells were chosen because they are intimately involved in periodontal therapy and are important for the success of surgical procedure such as guided tissue regeneration. The aim of the present study was to elucidate whether cellular activity and collagen synthesis by glucose pre-treated human gingival fibroblasts and PDL cells are influenced by insulin, and whether healthy cells differ from glucose treated cells. Cells were cultured with DMEM at $37^{\circ}C$, 5% $CO_2$, 100% humidified incubator. To evaluate the effect of glucose on gingival fibroblasts and periodontal ligament cells, the cells were seeded at a cell density of $1{\times}10^4\;cells/well$ culture plates and treated with 20 and 50mM of glucose for 5 days. Then MTT assay was carried out. To evaluate the effect of insulin on glucose-pretreated cells, the cells were seeded at a cell density of $1{\times}10^4\;cells/well$ culture plates and treated with 20 and 50mM of glucose for 5 days. After incubation, $10^3$, $10^4$ and $10^5mU/l$ of insulin were also added to the each well and incubated for 2 days, respectively. Then, MTT assay and collagen synthesis assay were carried out. The results indicate that cellular activity of gingival fibroblasts significantly increased by glucose while periodontal ligament cells were unaffected and cellular activity of gingival fibroblasts and periodontal ligament cells were unaffected by insulin. Collagen synthesis of gingival fibroblast with 20mM glucose and insulin unaffected, but 50mM glucose and insulin increased than control. Collagen synthesis of periodontal ligament cell with 20mM glucose and $10^5mU/l$ insulin significantly increased than other groups and 50mM glucose pretreated PDL cells significantly increased at $10^3mU/l$ insulin but decreased at $10^4mU/l$ insulin. Our findings indicated that these cell types differed in their growth response to glucose, and the increase in collagen synthesis was significantly raised at insulin level of $10^3mU/l$ in gingival fibroblasts and periodontal ligament cells except 20mM glucose pretreated periodontal ligament cells.

• Journal of the korean academy of Pediatric Dentistry
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• v.32 no.4
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• pp.620-627
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• 2005

The purposes of early orthodontic intervention are to correct obvious problems, to intercept developing problems and prevent them from becoming worse. Myofunctional influence on facial growth and the dentition change in muscle function and initiate morphologic variation in the normal configuration of the teeth and enhance an already existing malocclusion. Myofunctional therapy has been advocated since 1960's as the treatment for tongue thrust and other oral habits. Pre-orthodontic $TRAINER^{(R)}$ is introduced as functional device usable in children of mixed dentition to correct functional problems concerning soft tissue, tooth and skeleton. The most common cases to treat with Pre-orthodontic $TRAINER^{(R)}$ are lower anterior crowding, anterior open bite, Class II malocclusion and deep bite. Also, it can be used as correction of oral habits. Patients in this cases visited Department of Pediatric Dentistry, School of dentistry, Dankook University for orthodontic treatment. Pre-orthodontic treatment with Pre-orthodontic $TRAINER^{(R)}$ was carried out for correction of the oral habits.

• Journal of Bio-Environment Control
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• v.29 no.3
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• pp.293-305
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• 2020

This experiment was aimed to identify concentrations of mineral nutrients in leaf lettuce (Lactuca sativa) grown on hydroball aquaponics and in the water for growing fish by conducting two experiments. The experiment I (Expt. I) was conducted with 12 fishes (F12) with and without filter, hydroball and plants (H12 (12 fishes, hydroball), FHP12 (12 fishes, filter, hydroball, 6 plants) and HP12 (12 fishes, hydroball, 6 plants)), and the experiment II (Expt. II) was with and without plants (FH15 (15 fishes, filter, hydroball), FHP15 (15 fishes, filter, hydroball, 6 plants)). The pH level in the water of all the treatments was decreased during the growing period, and the pH and EC of the water were lower in all the treatment with plants than those without plants in both Expt. I and Expt. II. When compared with adequate nutrient concentrations for hydroponics, nitrate nitrogen (NO₃-N) and phosphorus (P) concentrations in the fish growing water were higher under the FHP15 treatment in Expt. II; however, potassium (K), calcium (Ca), and magnesium (Mg) were only 16, 49, and 82% of hydroponics, representatively, and iron (Fe) was not detected. The fresh weight of lettuce harvested from the FHP15 treatment was 38 g, only a 30% of marketable lettuce yield. The T-N and P contents of the leaf tissue grown under the FHP15 treatment were close to the optimal level; however, the K, Ca, and iron (Fe) contents were less than the optimal with no deficiency symptom.

• Clinical and Experimental Reproductive Medicine
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• v.25 no.2
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• pp.115-122
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• 1998

The maintenance of a viable pregnancy has long been viewed as an immunological paradox. The deveolping embryo and trophoblast are immunologically foreign to the maternal immune system due to their maternally inherited genes products and tissue-specific differentiation antigens (Hill & Anderson, 1988). Therefore, speculation has arisen that spontaneous abortion may be caused by impaired maternal immune tolerance to the semiallogenic conceptus (Hill, 1990). Loss of recall antigen has been reported in immunosuppressed transplant recipients and is associated with graft survival (Muluk et al., 1991; Schulik et al., 1994). Progesterone $(10^{-5}M)$ has immunosuppressive capabilities (Szekeres-Bartho et al., 1985). Previous study showed that fertile women, but not women with unexplained recurrent abortion (URA), lose their immune response to recall antigens when pregnant (Bermas & Hill, 1997). Therefore, we hypothesized that immunosuppressive doses of progesterone may affect proliferative response of lymphocytes to trophoblast antigen and alloantigen. Proliferative responses using $^3H$-thymidine ($^3H$-TdR) incorporation of peripheral blood mononuclear cells (PBMCs) to the irradiated allogeneic periperal blood mononuclear cells as alloantigen, trophoblast extract and Flu as recall antigen, and PHA as mitogen were serially checked in 9 women who had experienced unexplained recurrent miscarriage. Progesterone vaginal suppositories (100mg b.i.d; Utrogestan, Organon) beginning 3 days after ovulation were given to 9 women with unexplained RSA who had prior evidence of Th1 immunity to trophoblast. We checked proliferation responses to conception cycle before and after progesterone supplementation once a week through the first 7 weeks of pregnancy. All patients of alloantigen and PHA had a positive proliferation response that occmed in the baseline phase. But 4 out of 9 patients (44.4%) of trophoblast antigen and Flu antigen had a positive proliferative response. The suppression of proliferation response to each antigen were started after proliferative phase and during pregnancy cycles. Our data demonstrated that since in vivo progesterone treated PBMCs suppressed more T-lymphocyte activation and $^3H$-TdR incorporation compare to PBMCs, which are not influenced by progesterone. This data suggested that it might be influenced by immunosuppressive effect of progesterone. In conclusion, progesterone may play an important immunological role in regulating local immune response in the fetal-placental unit. Furthermore, in the 9 women given progesterone during a conception cycle, Only two (22%) repeat pregnancy losses occured in these 9 women despite loss of antigen responsiveness (one chemical pregnancy loss and one loss at 8 weeks of growth which was karyotyped as a Trisomy 4). These finding suggested that pregnancy loss due to fetal aneuploidy is not associated with immunological phenomena.

• Polymer(Korea)
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• v.35 no.1
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• pp.7-12
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• 2011

Poly(lactic-co-glycolic acid) (PLGA) is a biodegradable synthetic polymer with acceptable mechanical strength and well-controlled degradation rate. Also, it can be easily fabricated into many shapes. Silk fibroin contains powerful bioactive molecules. We fabricated natural/synthetic hybrid films using 0, 10, 20, 40 and 80 wt% of silk fibroin. Schwann cells (SCs) were seeded on PLGA/silk fibroin hybrid films and confirmed the effects of adhesion and proliferation on SCs according to the content of silk fibroin. In this study, we confirmed PLGA/silk fibroin hybrid film containing 40% and 80% of silk fibroin interrupted adhesion and proliferation of SCs. Films containing 10% and 20% of silk, however, provided suitable environment for growth and proliferation of SCs. These results suggest that silk fibroin provides suitables surface to neural cells and its proper content provides proper culture conditions to improve cell adhesion and proliferation.

• Polymer(Korea)
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• v.37 no.2
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• pp.141-147
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• 2013

Poly(lactide-co-glycolic acid) (PLGA) has been widely used in the drug delivery and tissue engineering applications because of its good mechanical strength and biodegradation profile. However, cell attachment to the scaffold is low compared with that on fibrin although cells can be attached to the polymer surface. In this study, PLGA scaffolds were soaked in cells-fibrin suspension and polymerized with dropping fibrinogen-thrombin solution. Cellular proliferation activity was observed in PLGA/fibrin-seeded costal cartilage cells (CC) on 1, 3, and 7 days using the MTT assay and SEM. The effects of fibrin on the extracellular matrix (ECM) formation were evaluated using CC cell-seeded PLGA/fibrin scaffolds. The PLGA/fibrin scaffolds elicited more production of glycosaminoglycan (GAG) and collagen than the PLGA scaffold. In this study, fibrin incorporated PLGA scaffolds were prepared to evaluate the effects of fibrin on the cell attachment and proliferation in vitro and in vivo. In this result, we confirmed that proliferation of cells in PLGA/fibrin scaffolds were better than in PLGA scaffolds. The PLGA/fibrin scaffolds provide suitable environment for growth and proliferation of costal cartilage cells.

• Restorative Dentistry and Endodontics
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• v.26 no.2
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• pp.141-152
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• 2001

Eliminating the infecting bacteria of the root canal system and preventing reinfection must be the main objectives of all endodontic works. None of commercially available root canal sealers have the properties of desirable tissue compatibility and strong antibacterial activity. The purpose of this study is to develope an ideal root canal sealer using commercially available polyphosphate (polyP), Calgon, which is known to be antibacterial and safe. For the study. resin type AH26, zinc oxide eugenol type Tubli Seal. Ca(OH)$_2$ type Apexit as base sealers for polyP (0~3%) and para formaldehyde containing N2 as a control base were selected. Specimens (3$\times$4mm) of the sealers were prepared in a 37$^{\circ}C$ incubator for 3 and 10 days and their antibacterial activity against streptococci and black pigmented anaerobic rods was observed using an agar diffusion method. The result were as follows: 1. Among 3 day old root canal sealers. N2 as a positive control showed the strongest antibacterial effect. followed by AH26. Tubli Seal and. Apexit which barely showed antibacterial activity against the test bacteria. In contrast. 10 day old AH26 showed a greater antibacterial activity than 10 day old N2. 2. All sealer specimens showed a greater antibacterial activity against black pigmented anaerobic rods than streptococci. Three day old ones appeared to be more antibacterial than 10 day old ones except for Apexit. 3. As compared to N2, 3 day old AH26 demonstrated a similar antibacterial activity against black pig mented anaerobic rods but to a lesser extent to streptococci. Ten day old AH26 showed a greater antibacterial activity against black pigmented anaerobic rods than 10 day old N2. 4. As compared to AH26. Tubli Seal generally revealed a lower antibacterial activity but it showed a greater antibacterial activity aginst S. gordonii Challis. 5. Enhancement of antibacterial activity by polyP was more clearly observed when it was added to Ca(OH)$^{\circ}C$ based root canal sealers. Tubli Seal and N2. 6. The addition of polyP enhanced the antibacterial activity of 3 day old AH26 against S. gordonii G9B (16%) and Challis (29%), and P. gingivalis 2561 (24%) only. Moreover, polyP failed to increase antibacterial activity of 10 day old AH26 against the test strains but P. gingivalis A7A1 28(13%). 7. The addition of polyP increased the antibacterial effect of 3 day old Tubli Seal on several test bacteria including s. mutans GS 5 (50%). s. gordonii G9B (47%) and Challis (122%). and all the test strains of P. gingivalis (13~35%) except for 9 14K 1. The addition of polyP to 10 day old Tubli Seal increased antibacterial activity of the root canal sealer against most test strains. 8. 3 day old Apexit failed to show antibacterial activity. if any very little against S. mutans GS 5 and Pr. intermedia ATCC 49046. However. polyP increased its antibacterial activity by 50 and 69%, respectively. Increase of antibacterial activity of 10 day old Apexit by polyP was more clearly observed than that of 3 day old one.

• Journal of Life Science
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• v.19 no.11
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• pp.1651-1657
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• 2009

Physical activity and exercise can promote sensorimotor recovery from central nerve injury. It has been suggested that the functional recovery promoted by exercise training after spinal cord injury might be associated with insulin-like growth factor-I in the inflicted muscle. To investigate morphological and biochemical change of the soleus muscle after spinal cord injury, all tissues were used for H&E, immunofluorescence staining and Western blot. Also, BBB-test was used to evaluate behavioral improvement after spinal cord contusion. Thirty male Sprague-Dawley rats ($230{\pm}10\;g$; 7week in age) were assigned equally to three different groups; Normal (n=10), SCI (n=10), SCI+TMT (n=10). Every rat in SCI and SCI+TMT groups underwent laminectomy at T9 level and then contusion on the exposed spinal cord site in anesthetized condition. After one week-recovery from contusion, every rat in the SCI+TMT group exercised on a motorized treadmill for 30min/d, 5d/wk for 7wks. TMT followed by injury increased IGF-I induction levels in the soleus muscle and inhibited muscle atrophy. Behavioral scales for 4 and 8 weeks after spinal cord injury were improved in the SCI+TMT group compared to the SCI group. These results suggest that treadmill exercise after spinal cord injury might promote functional recovery along with muscle regrowth through the up-regulation of IGF-1 in muscle tissue.

• Journal of Life Science
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• v.18 no.3
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• pp.344-349
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• 2008

Normal somatic cells proliferate for a limited number of doublings in culture and then enter an irreversible growth-arrest state called replicative senescence. Replicative senescence has been believed a reason for the limited cellular turnover and deterioration of tissue function in aged animals. However, there is no experimental evidence supporting this assumption. Furthermore, cells from aged person have been poorly characterized with an exception of the cases of T cells. In this study, we examined cell biological changes occurring in replicative senescence of fibroblast strains originated from a new-born (NHF-NB) and a 87 year old man (NHF-87). NHF-87 (and the cells from a 75-year old) proliferated to smaller population doublings and with longer doubling times than NHF-NB did. At early passages, NHF-87 exhibited a low senescence-associated ${\beta}-Gal$ (SA ${\beta}-Gal$) activity and lipofuscin level, typical markers for cellular senescence. Furthermore, they maintained low levels of lysosome and reactive oxygen species (ROS). All of these levels increased dramatically in the late passage NHF-87 quite similarly as those in the late passaged NHF-NB did. These results indicate that most cells originated from the aged maintain a phenotype of the cells originated from new-born donors and undergo replicative senescence with the same kinetics as that of the cells from new-born. It is also indicated that not SA ${\beta}-gal$ activity but cell proliferation rate may be qualified as a biomarker for cells aged in vivo.