• Microbiology and Biotechnology Letters
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• v.24 no.1
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• pp.9-18
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• 1996

Streptococcus mutans has been implicated as primary causative agents of dental caries by insoluble glucan (IG) in human and experimental animals. An attempt was made to search for the ${\alpha}$-1,3 glucanase that degrades IG produced by S. mutans. ${\alpha}$-1,3 glucanase was detected in the culture supernatant of microorganisms, which are isolated from soils on agar medium containing IG as a sole carbon source. This Streptomyces sp. hydrolysed IG produced by immobilized S. mutans and was named as Y9373. This enzyme required ${\alpha}$-1,3 glucan (IG) as an inducer. The optimum conditions for enzyme production were studied. The enzyme was purified by 30~70% $(NH_4)_2SO_4$ precipitation, anion exchange chroma tography on DEAE-cellulose and gel filtration on Sepadex G-75. The purified enzyme has a specific activity of 7840.0 U/mg protein giving 32.1-fold purification and final yield of 0.53%. The molecular weight was estimated to be about 22.5 kDa by SDS-PAGE. The optimum pH and temperature for enzyme reaction were 6.5 and 37$^{\circ}C$, respectively and the enzyme was relatively stable at the temperature below 60$^{\circ}C$. The activity of purified enzyme was enhanced by adding $Co^{2+},\;Mn^{2+}\;and\;Mg^{2+}$ into the medium, whereas inhibited by adding $Hg^{2+},\;Zn^{2+}$ and SDS. The $K_m\;and\;V_{max}$ value of ${\alpha}$-1,3 glucanase for IG were estimated to be 2.50 mM and 0.0431 mM/min, respectively. The thin layer chromatographic analysis of hydrolysates from IG with ${\alpha}$-1,3 glucanase showed that glucose was the main product of reaction. This enzyme activity was about 14 times higher than marketing dextranase as preventive agent against artificial dental caries by S. mutans in TH medium including 5% sucrose after 30 minutes.

• KSBB Journal
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• v.23 no.2
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• pp.109-117
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• 2008

Phellinus linteus (Sang Hwang mushroom; P. linteusis) has been widely used for a traditional medicine in Japan, Korea and China. In traditional oriental applications, P. linteus and their extracts have been exclusively used to treat various diseases like insomnia, neurasthenia, gastric ulcers, arthritis, nephritis, stress, asthma, bronchitis, neuromuscular disorders, hypertension and also as an immune system stimulator in cancer therapy. In a number of articles, it is indicated how tremendous their therapeutic values are. According to these studies, P. linteus and their extracts show immunomodulatory activities like enhancing immune system function including anti-tumor activity and inhibiting the growth of existing tumors. P. linteus and their extracts have been being studied for use as immunotherapy agents and biological response modifiers (BRMs) for the possible treatment of cancer without side effects. Recently, the cultured mycelium product of P. linteus has been developed and approved as a medicine in Korea. This review shows not only the current status of methods of developmental technology like artificial culture and various biological applications of P. linteus but also recent market trends of functional foods made from P. linteus.

• Journal of Plant Biotechnology
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• v.30 no.1
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• pp.73-80
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• 2003

Useful Dianthus species were collected and selected from two native and seven foreign species distributed in Gangwon province. For in vitro breeding,. callus was induced from the explants of apical meristem, leaf, stem and the in vitro adventitious shoots on MS basal medium with 2.0 mg/L 2,4-D and 0.5 mg/L BA at 27$^{\circ}C$ under continuous light. After 3 weeks of culture, calli initiated the most highly from the leaf explants of D. chinensis Organogenic calli were able to be selected from the adventitious shoot-derived calli. For shoot regeneration, these organogenic calli were cultured on MS medium with the combination of 0.1 mg/L NAA＋1.0 mg/L BA under continuous light. Multiple shoots were proliferated with low frequency (about 30%) from those adventitious shootderived calli. Also, shoots initiated directly from the adventitious shoot explants without callus formation at high frequency of 52% when cultured on N6 medium containing 0.1 mg/L NAA and 1.0 mg/L BA in D. gratianopol. Multiple shoots and plantlets grew well and rooted on MS medium supplemented with 0.1 mg/L NAA. Regenerants with well-developed roots were transferred to 8-cm pots containing vermiculite at 85% relative humidity and 27$^{\circ}C$ These plantlets were acclimatized in artificial soil mixture and transferred to the greenhouse for flowering with normal phenotypes. M28 Mutant line was selected with white flowers from 0.03M EMS-treated organogenic calli derived from in vitro adventitious shoot explants of D. chinensis and set seeds.

• Journal of fish pathology
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• v.27 no.2
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• pp.107-114
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• 2014

For the treatments and protection of bacterial fish disease, many requirements are needed for aquatic probiotics so that they are effective in aquaculture animals but are also harmless to humans. In the present study, among 17 candidate probiotic bacteria (CPB) obtained from the edible part of the shellfish, Bacillus sp. CPB-St (CPB-St) were selected and in vitro evaluated for the possibility as a probiotic strain for the control of fish streptococcosis which frequently occurs in the olive flounder farms. CPB-St showed inhibitory effects on the growth of various fish pathogenic bacteria, Streptococcus sp., S. parauberis, S. iniae, Lactococcus garvieae and L. piscium by the double layer test ranging about 18~26 mm of clear zone. Inhibitory activity of CPB-St to Streptococcus sp. was observed 6 hours after and the growth of Streptococcus sp. was decreased to 8~55 folds in the co-culture of CPB-St with Streptococcus sp.. The safety of CPB-St to fish and survival of CPB-St in the intestine were assessed in the olive flounder, Paralichthys olivaceus. Fish mortality was not observed in artificial infection with CPB-St for 2 weeks. CPB-St was entirely excreted from the stomach and intestine 24 hours after oral injection. This results indicate that CPB-St has potential applications as a probiotic for the control of fish streptococcosis in aquaculture.

• Pediatric Infection and Vaccine
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• v.3 no.2
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• pp.145-153
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• 1996

The incidence of Adenovirus(AV) pneumonia in children is estimated at 8%. Long-term complications reported with type 7 include hyperleucent lung syndrome, bronchiolitis obliterans and may require several months to recover. We reviewed 8 case of AV pnemonia confirmed by AV culture and sero-diagnosis among selected 19 AV pneumonia suspicious cases who were admitted to the Sanggye Paik Hospital of Inje University due to clinical pneumonia from May to July 1996. From 19 children, nasal aspirates or trachial aspirates were collected: viral agents were detected by virus isolation and virus antigen was detected by indirect immunofluorescent staining. Serologic diagnosis for type-specific AV antibody was done by neutralisation test. The results are as follows: 1) Age of the patients ranged from 6 months to 47 months with a mean of $24{\pm}9$ months. 6 were male and 2 were female(M:F= 3:1). 2) Monthly distribution showed 4 cases on June, 2 cases on May and July, respectively. 3) The mean duration of admission was 20.4 days and mean duration of fever was 11.3 days 4) Peripheral leukocyte counts were elevated in 4 cases(50%) and findings of shift to left were showed in 4 cases(50%) and serum aminotransferase activities were elevated in 6 case(75%). 5) Radiologic findings include linear and streaky infiltration(1/8 cases), patchy and lobar consolidation (7/8 cases), pleural effusion(2/8 cases) and hyperleucency was seen in 3/8 cases at time of admission and increased to 6/8 cases on hospital discharge. 6) The AV serotypes were type 7, type 3, and type 1. 7) Oxygen supply was done in 4 cases(50%) and all 8 patients include 2 cases of type 7 treated with artificial ventilator were survived. In conclusion, the serotypes of AV pneumonia outbreaks in early summer of 1996 were type 7, 3, 1 and, as showed severe clinical course, continued follow up surveillance is necessary to the long term pulmonary complications.

• The Korean Journal of Mycology
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• v.25 no.3 s.82
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• pp.209-218
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• 1997

This study was carried out to obtain the basic data for artificial culture of Grifola umbellata. The optimal condition for the mycelial growth was obtained at $20^{\circ}C$ and pH 4, respectively. G. umbellata showed the most favorable growth on the Hoppkins media. Carbon sources such as glucose, fluctose and manitol were favorable for stimulating a mycelial growth of G. umbellata. Valine, one of nitrogen sources also appeared to be favorable to a mycelial growth. The optimum C/N ratio was about 30:1 in case that 1% glucose as carbon source was mixed with the basal media. Lactic acid as organic acid was most favorable to the mycelial growth. Also, thiamine-Hcl as vitamin source was favorable. The mineral nutrient of $FeSO_4$ or $MgSO_4$ was most favorable to G. umbellata, and its optimal concentration was about 0.01% in $FeSO_4$ and 0.1 % in $MgSO_4$ respectively. Among 4 different cereal extract media, polished rice extract medium which was mixed with silkworm pupae was most suitable for a favorable growth of G. umbellata.

• The Journal of Korean Academy of Prosthodontics
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• v.37 no.1
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• pp.1-22
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• 1999

In order to investigate various physical and biological properties of dental magnetic attachments studies on retentive characteristics, corrosion properties, cytotoxicity of different magnetic systems for dental applications were done. For the study of retentive characteristics changes of retentive force by increasing air gap, wear properties of various attachment systems and loss of magnetic force by heat treatment were measured. Forte study of corrosion property of magnet covering metal electrochemical corrosion was done in artificial saliva and 0.9% NaCl solution between $-1,000mV_{SCE}\;and\;+1,000mV_{SCE}$. Anodic polarization curves are obtained about 6 types of samples and 2 types of solution. Corroded surfaces were examined with metallurgical microscope, scanning electron microscope and surface profilometer. For the study of cytotoxicity of magnetic attachment and its field cell growth and agar overlay test were done. The results of this study were as follows. 1. In Magnetic attachments using closed circuit retentive force at zero air gap was greater than magnets using open circuit, but decrease of retentive force by increasing air gap was also greater than open systems. 2. After 40,000 cycles of wear test all mechanical attachment resulted in varing degree of retention loss but in magnetic attachments no loss of retentive force was observed. 3. The magnetic attachment using Neodymium magnet showed early loss of retentive force about $200^{\circ}C$ but attachment using Samarium magnet showed some resistance to heat treatment and complete retention loss was observed about $500^{\circ}C$. The keeper was not influenced by heat treatment in retention. 4. In electrochemical corrosion test Dyna magnetic attachment covering metal showed the highiest corrosion resistance and Shiner magnet covering metal showed the least corrosion resistance and examination of corroded surface with metallurgical microscope, scanning electron micro-scope and surface profilometer also showed same results with anodic polarization corves. 5. The result of cell culture tests on the magnet covered with metal showed least recognizable cytotoxicity.

• Journal of Aquaculture
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• v.20 no.1
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• pp.31-40
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• 2007

To find out the effect of the spat planting time and environmental factors in the arkshell, Scapharca broughtonii (Schrenck), we investigated the growth, survival rate of arkshell and habitat characteristics in Gamak Bay, Yeoja Bay and Saryang Island. We planted artificial spats of arkshell in Gamak Bay and Yeoja Bay at November 2004, and also planted domestic and Chinese natural spats in Saryang Island at March 2005. We measured growth, survival rate of arkshell, physiochemical parameters of the water mass (water temperature, salinity, dissolved oxygen, nutrients and chlorophyll a) and characteristics of the sediment (oxygen penetration depth, oxygen microprofiles, ignition loss and chemical oxygen demand) by monthly. The cumulative survival ratio of arkshell in Gamak Bay was the highest at December, whereas the ratio of arkshell in Yeoja Bay was recorded as 0% at October. The monthly growth rates of arkshell length in Gamak Bay and Yeoja Bay were the highest in May and the growth rate of the Korean arkshell in Saryang Island was higher than Chinese ones significantly. The high mortality (> 65%) of the arkshell in Yeoja Bay during summer probably caused by high water temperature, inflow of low salinity water, and low dissolved oxygen concentration in sediment. The concentrations of nutrient and sediment COD were considered to play an important role in the monthly survival ratio of arkshell in Gamak Bay and Sarayng Island. We suggest that the growth and mortality of arkshell might be influenced to the planting time of spat and the habitat characteristics.

• Clinical and Experimental Reproductive Medicine
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• v.25 no.2
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• pp.123-128
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• 1998

Implantation rates remain low following human in vitro fertilization (IVF). Suboptimal culture conditions may limit the ability of embryos to hatch as blastocysts, and artificial opening of the zona pellucida has been proposed as a means to promote subsequent hatching (assisted hatching). In this study, assisted hatching (AH) by zona drilling using acidic Tyrode's solution was performed in 320 patients, due to their age of more than 38 years (group A), the thick zona pellucida (group Z; $ZP\geq0.18{\mu}m$), and failures in implantation more than 3 times in previous IVF-ET trial (group P). This study was designed firstly, to study the effects of AH on the outcomes of IVF-ET according to the indications and secondly, to verify the appropriate application of AH. The results were as follows; 1. There was no difference in pregnancy rate between AH group (26.6%) and non-AH group (26.5%). 2. Assisted hatching (AH) showed significantly higher pregnancy rate of the patients with thick zona pellucid a than those of the patients with age factor and with the history of repeated implantation failure. But in the patients with age factor only, AH resulted in higher pregnancy rate. 3. Interestingly, the patients with complex factors including zona factor (Z: 33.9%; ZA: 30.4%; ZP: 31.6%; ZAP: 21.4%) showed higher pregnancy rates than other complex factors excluding zona factor (A: 24.4%, P: 0%; AP: 10.8%). From these results, AH is more helpful to the patients with thick zona pellucida rather than patients with older age and/or previous repeated implantation failure.

• The Korean Journal of Mycology
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• v.24 no.3 s.78
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• pp.214-222
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• 1996

This study was carried out to obtain the basic data on artificial culture of Phellinus linteus. The optimum condition for the mycelial growth was $25{\sim}30^{\circ}C$ and pH $6.0{\sim}7.0$. The carbon sources such as D-glucose, D-mannose and Dextrose were favorable to mycelial growth. As nitrogen sources, peptone, cassamino acid and glutamic acid appeared to be favorable. The optimum C/N ratio was about 20:1, when 2% of glucose was provided as a carbon source. The better organic acids and vitamin among tested ones were gallic, silicic acids and biotin. The mineral nutrients of $KH_2PO_4,\;FeSO_4{\cdot}7H_2O,\; MgSO_4{\cdot}7H_2O,\;ZnSO_4{\cdot}7H_2O$ were effective and the optimum concentrations were 0.05, 0.001, 0.02 and 0.003%, respectively.