• 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.

• Journal of Plant Biotechnology
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• v.44 no.1
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• pp.42-48
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• 2017

This study was conducted to establish the optimal condition for in vitro propagation of Disporum sessile. In the experiments with different kinds of media (MS, B5 and WPM) and explant types for shoot induction and elongation, the highest number of shoot inductions (2.5/explant) was shown when the axillary bud explants were cultured on MS medium without plant growth regulators (PGRs). The best shoot elongation (7.2 cm) was also obtained when the apical buds were cultured on MS medium. The effect of BA pulse treatments with in vitro shoots was also examined. The highest in shoot induction (2.29/explant) and elongation (7.28 cm) was observed when the shoots from axillary buds were cultured on the media without PGRs. However, it decreased with increasing duration of BA pulse-treatment. The highest rooting rate (100%) and number of root inductions (21.3/explant) were achieved with 1.0 mg/L indole-3-butyric acid (IBA) treatment, whereas no differences were observed by different shoot types. The regenerated in vitro plantlets were hardened and successfully established in soil.

• Korean Journal of Plant Resources
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• v.21 no.2
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• pp.111-116
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• 2008

This study was carried out to induce plant regeneration via multiple shoot formation from sucker explants of Rubus fruticosus L. ${\times}$ R. parvifolius L. To induce adventitious shoots, the sucker explants were sterilized in 1.2% sodium hypochlorite (NaOCl) solution, and then were cultured on the full and 1/2 MS solid medium supplemented with BA (0.1, 0.5, 1.0, $2.0mg{\cdot}L^{-1}$). After 4 weeks of culture, the highest frequency (83.3%) of shoot formation from sucker explants was obtained from the full MS medium with $1.0mg{\cdot}L^{-1}$ BA. The highest shoot number (3.7) per explant was obtained from the full MS medium with $0.5mg{\cdot}L^{-1}$ BA. After 12 weeks of culture, the number of shoots (15.4) per explant was increased. The highest frequency (95%) of root formation was obtained from the 1/2 MS medium, when the explant with shoot were cultured on the full, 1/2 and 1/4 MS medium. The survival rate of the plantlets after transfer to plastic pots containing sand, soil, and vermiculite (1.1:1, vol.) was 95%. The results indicate that multiple shoot procedure can be applied for an efficient mass propagation of Rubus fruticosus L. ${\times}$ R. parvifolius L.

• Journal of Periodontal and Implant Science
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• v.25 no.3
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• pp.539-556
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• 1995

Periodontal therapeutic modalities should be re-establishing and regenerating the periodontal tissue previously lost to the disease. To achieve periodontal regeneration, periodontal ligament cells must selective migrate to the deneded root surface, attached and proliferated it. Local pH concentration is one of the most factors that periodontal regeneration. The aims of this study were to examine on biological effects of pH to the human periodontal ligament cells in vitro, especially on the cell morphology, attachment, activity, vitality and viability. Human periodontal ligament cells were cultured from extracted tooth for non-periodontal reason. Immediately after extraction, any soft tissue adhering to the cervical parts of the roots was carefully removed with a sterile curette. To produce different pH levels in the media, Eagle's MEM was adjusted from pH 6.6 to 8.2 in 0.2 intervals with 1 M NaOH and 1 N HCl. After cultivation, Then, Periodontal ligament cells were cultured at pH ranging from 6.6-8.2. attachment assay was done at 1, 2 day incubation and activity assay was done at 1, 2, 3 day incubation. The experiments were evaluated by scaning electron microscopic techniques (HITACHIX-650 Scaning Electron Microanalyzer, Tokyo, Japan), MTT assay, and the cultured periodontal ligament cells were fixed in neutral formalin for 24 hours and immunohistochemically processed by PCNA for proliferating ability. The surviving cells in the medium showed slightly increased volume and widening intercellular distances at low concentration of pH than control group (pH 7.4), and apparently shrinkage at high concentration of pH than control group (pH 7.4). The results of the statistical analysis from the experiment on attachment, vitality and viability were as follows. Attachment of periodontal ligament cells at 1st and 2nd day, similar attachment rate of low concentration pH compared with control value (pH 7.4). But above pH 8.0, attachment rate were statistically significant decrease from control value(P<0.05). Periodontal ligament cell's activities were maximum at pH 7.6 by MTT assay. Similar with control value at low concentration of pH. But, the activities were statistically significant decrease at high concentraration of pH(P<0.05). Cellular proliferating rate (PCNA index) were statistically significant decrease from control value at low and high concentration of pH(p<0.05). This results suggested that hjgh concentration pH, in other words, alkali pH was cytotoxic effects on human periodontal ligament cells in vitro.

• The Journal of Internal Korean Medicine
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• v.33 no.2
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• pp.126-144
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• 2012

Background : Peripheral nerves more rapidly recover than central nerves. However, it has been known that the degree of reaction of axons of peripheral nerves is affected by distinctive characteristics of axons and environmental factors near the axons. Taxol is a widely used medicine as for ovarian, breast, lung and gastric cancer. However it causes patients difficulties under treatment due to its toxic and side effects, which include persistent pain. Objectives : This study reviewed how SJT extract in vitro and in vivo affects nerve tissues of a sciatic nerve damaged by Taxol. It also studied how SJT extract in vivo affects axons of the sciatic nerve after the sciatic nerve was damaged by pressing. Methods : After vehicle, Taxol, and Taxol plus SJT were treated respectively for tissue of the sciatic nerve in vitro and then tissues were observed using Neurofilament 200, Hoechst, ${\beta}$-tubulin, $S100{\beta}$, caspase-3 and anti-cdc2. SJT was also oral medicated by injecting Taxol into the sciatic nerve of in vivo rats. Tissues of the sciatic nerve and axons of DRG sensory nerves were then observed using Neurofilament 200, Hoechst, ${\beta}$-tubulin, $S100{\beta}$, caspase-3 and p-Erk1/2. After inflicting pressing damage to the sciatic nerve of in vivo rats, tissues of the sciatic nerve and DRG sensory nerve were observed using Neurofilament 200, Hoechst, $S100{\beta}$, caspase-3, anti-cdc2, phospho-vimentin, ${\beta}1$-integrin, Dil reverse tracking and p-Erk1/2. Results : The group of in vitro Taxol plus SJT treatment had meaningful effects after sciatic nerve tissue was damaged by Taxol. The group of in vivo SJT treatment had effects of regenerating Schwann cells and axons which were damaged by Taxol treatment. The group of in vivo SJT had effects of regenerating axons in damaged areas after the sciatic nerve was damaged by pressing, and also had variations of distribution in Schwann cells at DRG sensory nerves and axons. Conclusions : This study confirmed that SJT treatment is effective for growth of axons in the sciatic nerve tissues and improvement of Schwann cells after axons of the sciatic nerve tissues was damaged. After tissues of sciatic nerve was damaged by pressing in vivo, SJT treatment had effects on promoting regeneration of axon in the damaged area and reactional capabilities in axons of DRG sensory nerves.

• Journal of Plant Biotechnology
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• v.45 no.3
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• pp.266-272
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• 2018

A Polygonatum stenophyllum Maxim. is an important endangered plant belonging to the family Liliaceae. A method was developed for the rapid micropropagation of P. stenophyllum through plant regeneration from rhizome (1-year, 3-years, and 5-years) explant-derived calli. The rhizome segments were cultured in Murashige and Skoog (MS) medium supplemented with varying concentrations of 2,4-D (0, 0.5, 1.0, $1.5mg{\cdot}L^{-1}$) for callus induction. In media supplemented with $0.5mg{\cdot}L^{-1}$ of 2,4-D, 87% of 3-years rhizome produced callus. Subsequently, the callus was transferred to 1/2MS medium supplemented with various concentrations of IAA, IBA, NAA, and 2,4-D (0, 0.1, 0.5 and $1.0mg{\cdot}L^{-1}$) for adventitious shoot formation. The highest percentage of adventitious shoot induction (57%) was observed in 1/2MS medium containing $0.5mg{\cdot}L^{-1}$ of NAA. Elongation of the adventitious shoot was achieved in 1/2MS medium supplemented with $0.1mg{\cdot}L^{-1}$ of BA. Rooting was achieved in 1/2MS medium without any hormones. It is hypothesized that the stated in vitro propagation protocol will be useful for conservation and mass propagation of the endangered Polygonatum stenophyllum Maxim. for bioresources.

• Korean Journal of Agricultural Science
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• v.14 no.2
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• pp.205-212
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• 1987

To examine the morphogenetic response, stem segments of 8 Populus spp. and 3 different explants of P. nigra var. italica were cultured on MS (Murashige and Skoog 1962) and WPM (Woody Plant Medium) medium containing various phytohormones. The results obtained were as follows: 1. Shoot regeneration and development from stem segment of 8 Populus spp. showed a quite difference according to the section and the species. All of the species of Leuce and Tacamahaca section did not form adventitious buds, while most of explants showed axillary or dormant bud elongation after 4 weeks. But P. nigra var. italica of Aigeiros section showed a successful adventitious bud formation (mean 5.4 buds per explant). 2. Leaf, petiole, and internode segment of P. nigra var. italica showed a quite differences according to media and ex plants upon the morphogenetic response. Adventitious bud formation from leaf was more abundant and readily initiated on the abaxial side than on the adaxial side. Mean number of 103 adventitious buds per explant was obtained from abaxial side of leaf segment cultured on WPM medium containing $0.2mg/{\ell}$ BAP for 5 weeks. 3. 2,4-D (2,4-dichlorophenoxy acetic acid) supplemented to media appeared to be negative upon the adventitious bud formation of P. nigra var. italica, while it promoted callus formation from all explants. Especially, NAA (${\alpha}$-naphtalene acetic acid) or NAA combination with BAP (6-benzylaminopurine) promoted root regeneration from the all explant of P. nigra var. italica in this study.

• Journal of Plant Biotechnology
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• v.41 no.3
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• pp.134-139
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• 2014

The aim of this study was to establish the condition of regeneration for white balloon flower (Platycodon grandiflorum DC. cv. Jangback) and to manage for the raising of seedling with in vitro regenerated plants. It was examined that 0.5 mg/L of NAA and 1.0 mg/L of BA was the best composition for the callus and shoot induction (up to 600%). NAA was better than IBA for the induction of root and it took 16.9 days for the induction of rooting on the MS soild media containing 0.5 mg/L of NAA and the final rooting ratio was up to 75%. Out of 5 different bed soils purchased from local market, "Tosil" was identified to be the best for the acclimation and growth of in vitro regenerated balloon flower. In detail, on 8 weeks after planting of in vitro regenerated plants in pots containing "Tosil" bed soils, the plant hight was increased up to 2-fold (12.8 cm), 3.5-fold (27) for the number of leaf and 1.5-fold (4.5 cm) for the leaf length when compared to the other four bed soils, respectively. Our preliminary results indicate that it is possible to prevent the occurrence of blue balloon flower in the massive cultivated area of white balloon flower by providing the seedlings raised from in vitro regenerated plants.

• Journal of Plant Biotechnology
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• v.40 no.4
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• pp.224-230
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• 2013

Lily is an important cut-flower in Korea and world as well due to it's a variety of flower colors and various sizes of flowers. To develop elite lily cultivars, conventional breeding techniques have been used so far. However, an introduction of tissue culture system in mass propagation of bulbs and regeneration of shoots with a high efficiency is prerequisite at this moment. Especially, growth of bulbs and shoots as well as reduction of browning is critical factor to proliferate bulbs with shoots of superior lines or cultivar in lily. For this purpose, we tried to test whether ascorbic acid, citric acid and silver nitrate in medium to facilitate growth of bulbs and shoots as well as reduction of browning of bulb scales in lily. As a result, ascorbic acid and silver nitrate showed no significant differences compared to control plants in the growth of bulbs and shoots. When bulb scales were treated with $150mg{\cdot}l^{-1}$ of citric acid, formations of shoots and bulbs showed best result. While, bulb scale treated with $100mg{\cdot}l^{-1}$ of citric acid showed the growth of shoot and root as well as increasing of fresh weight compared to other treatments. Regarding the reduction of browning, $150mg{\cdot}l^{-1}$ of ascorbic acid showed the best result with the less than 2%. Although more experiments with several commercial varieties are needed in the future to establish mass propagation of bulbs of lily, results obtained in this study are supposed to provide the basic knowledge and contribution in tissue culture system of lily.

• Journal of the korean academy of Pediatric Dentistry
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• v.39 no.2
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• pp.174-180
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• 2012

In case of an immature tooth with necrotic pulp, regeneration of pulp tissue into a canal would be the ideal outcome. It may be capable of promoting the continuation of normal root development. Platelet-rich fibrin has been suggested as a potentially ideal scaffold for regenerative endodontic treatment. Immature permanent teeth of young children were diagnosed with pulp necrosis and apical abscess as the result of clinical and radiographic examination. After removal of necrotic pulp, canal was irrigated with 5.25% NaOCl and dried with paper point. A triple antibiotic mixture was placed in canal space in 3 weeks. After removal of the antibiotic mixture, the platelet-rich fibrin was injected into the canal space with MTA placed directly over the platelet-rich fibrin clot. The coronal region was restored by composite resin. On the basis of short-term results of the present 3 cases, regeneration of vital tissues appears to be possible in a tooth with necrotic pulp and a periapical lesion. Also, platelet-rich fibrin proves to be potentially an ideal scaffold for this procedure. Therefore, long-term clinical observation and examination about this treatment using platelet-rich fibrin in immature permanent teeth of young children are considered to be necessary.