• Journal of Microbiology and Biotechnology
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• v.34 no.2
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• pp.289-295
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• 2024

We have developed an aptamer that specifically binds to Porphyromonas gingivalis to reduce the cellular damage caused by P. gingivalis infection and applied it as a biosensor. P. gingivalis is one of the major pathogens causing destructive periodontal disease among the periodontal microorganisms constituting complex biofilms. Porphyromonas gingivalis G-protein (PGP) known to play an important role in the transmission of germs was used as a target protein for the screening of aptamer. The aptamer that has binds to the G-protein of P. gingivalis, was screened and developed through the Systemic Evolution of Ligands by Exponential Energy (SELEX) method. Modified-Western blot analysis was performed with the aptamer which consisted of 38 single-stranded DNA to confirm the selectivity. ELONA (enzyme linked oligonucleotide assay) used to confirm that the aptamer was sensitive to PGP even at low concentration of 1 ㎍/ml. For the rapid detection of P. gingivalis, we constructed a surface plasmon resonance biosensor with SPREETA using the PGP aptamer. It was confirmed that PGP could be detected as low concentration as at 0.1 pM, which is the minimum concentration of aptamer sensor within 5 min. Based on these results, we have constructed a SPREETA biosensor based on aptamer that can bind to P. gingivalis G-protein. It can be used as an infection diagnosis system to rapidly diagnose and analyze oral diseases caused by P. gingivalis.

• Journal of Life Science
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• v.16 no.2 s.75
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• pp.199-205
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• 2006

Peroxisome proliferator activated receptor (PPAR)-$\alpha$ of three PPAR subtypes ($-\alpha,\;-\beta/-\gamma,\;-\delta$), which are members of the nuclear hormone receptor superfamily of ligand-activated transcription factors, plays a key role in lipoprotein and glucose homeostasis. A variation in the PPAR-a gene expression has been suggested to influence the development of metabolic syndrome through alterations in lipid concentrations. The aim of our study was to investigate the association between the PPAR-a and metabolic syndrome among South Korean. A total of 542 health screen examinees were enrolled in this study who were examined in Kosin University Gospel Hospital from December, 2004 to July, 2005. The height, weight, waist circumference, and systolic and diastolic blood pressure of the subjects were examined and fasting blood glucose, total cholesterol, HDL cholesterol, LDL cholesterol, triglyceride were measured by-sampling in venous blood. The metabolic syndrome was defined as the presence of three or more of the following : waist circumference men ${\geq}90cm$, women ${\geq}80cm$, blood pressure ${\geq}130/85mmHg$, fasting glucose ${\geq}110mg/dL$, HDL cholesterol men <40 mg/dL, women <50 mg/dL, triglyceride ${\geq}150mg/dL$. The blood pressure, fasting glucose, HDL cholesterol, triglyceride were evaluated by using the criteria of NECP ATP III and waist circumference was assessed by using the criteria of WHO Asia-Western Pacific. And the author compared the frequency of the PPAR-$\alpha$ mutation of L162V ($C{\rightarrow}G$ variant in exon 5) in a sample of 542 subjects with and without the metabolic syndrome by polymerase chain reaction allele-specific oligonucleotide (PCR-ASO) method. One (0.2%) hetero-isotype among high risk of metabolic syndrome was identified. The values of waist circumference, body mass index and low density lipoprotein cholesterol of the mutant were 100 cm, 28.6 $kg/m^2$ and 120 mg/dL, respectively. Although the author failed to see significant association between the presence of the PPAR-$\alpha$ L162V polymorphism and metabolic syndrome, one PPAR-$\alpha$ L162V polymorphism in metabolic syndrome patients was found.

• Journal of Periodontal and Implant Science
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• v.28 no.4
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• pp.659-678
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• 1998

In the present study, oligonucleotide probes based on 16S rRNA were taken to investigate the diversity of oral spirochetes without culture method. This is the first study that revealed oral spirochetes of both presently cultivable and uncultured oral spirochetes in Korean adult periodontitis patients. Subgingival plaque samples were taken from diseased sites(probing depth ${\geq}6\;mm$, experimental group, n=116) and healthy sites(probing depth${\leq}3mm$, control 1 group, n=28) in 29 patients with adult periodontitis, and from 20 periodontally healthy subjects(probing depth${\leq}3mm$, control 2 group, n=100). Following being examined under phase-contrast microscope, all samples were submitted to dot-blot hybridization after polymerase chain reacton with eubacterial primers. 5 species-specific probes(TVIN, TDEN, TMAL, TSOC, and TPEC) and 7 group-specific probes(TRE I, TRE II, TRE III, TRE IV, TRE V, TRE VI, and TRE VII) were used one by one for the identification of both cultivable and so far uncultivable oral spirochetes. All probes were labeled with digoxigenin(DIG)-ddUTP and detected by chemilumininescence. The following results were obtained. 1. Under phase-contrast microscope, 91.37% and 14.28% of oral spirochetes were observed in the experimental and control 1 groups, respectively. None of oral spirochetes were observed in control 2 group. 2. With universal probe, 98.27%, 46.42%, and 22.0% of oral spirochetes were observed in experimental, control 1, and control 2 groups, respectively. 3. With specific probe, 95.68%, 35.71%, and 19.0% of oral spirochetes were observed in experimental, control 1, and control 2 groups, respectively. 4. With species-specific probes, T. socranskii were recovered in a high percentage of sites(81.89%) examined, followed by T. maltophilum(50.0%), T. vincentii(36.20%), T. denticola(13.79%), respectively. With group- specific probes, TRE IV was recovered in a high percentage of sites(85.34%) examined, followed by TRE II(77.58%), TRE I(56.89%), TRE III(25.86%), TRE VI(5.17%), and TRE V(2.58%), respectively. 5. T. vincentii were only observed in the diseased sites, not in the healthy sites. 6. Neither T. pectinovorum nor group VII oral spirochetes were observed in any sites. The findings warrant further investgations of the recovered spirochetes to elucidate the possible associations of oral spirochetal prevalence in race and types of periodontitis, pathogenesis of T. vincentii and the possible distributional change of oral spirochetes before and after treatments.

• The Journal of Korean Academy of Prosthodontics
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• v.55 no.4
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• pp.361-371
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• 2017

Purpose: We aimed to investigate the gene expression of human gingival fibroblasts on microgroove surface using DNA microarray. Materials and methods: Microgrooves were applied on grade II titanium discs to have 0/$0{\mu}m$ (NE0, control group), 60/$10{\mu}m$ (E60/10, experimental group) of respective width/depth by photolithography. The entire surface of the microgrooved Ti substrata was further acid etched and used as the two experimental groups in this study. Human gingival fibroblasts were cultured in the experimental group and the control group, and total RNA was extracted. The oligonucleotide microarray was performed to confirm the changes of various gene expression levels between experimental group and control group. Changes of gene expression level were determined at the pathway level by mapping the expression results of DNA chips, using the KEGG (Kyoto Encyclopedia of Genes and Genomes) pathway analysis. Results: Gene expression levels on E60/10 and NE0 were analyzed, there were 123 genes showing significant differences in expression more than 1.5 times on E60/10 microgrooved surface compared to NE0 surface, and 19 genes showing significant differences in expression more than 2 times. The KEGG pathway analysis confirmed the changes in gene expression levels under experimental conditions. Cell signaling, proliferation, and activity among the various gene expression results were identified. Conclusion: Microgrooved surfaces induce gene expression changes and related cell signaling. According to the results of this study, microgrooves can be used as the surface of various biomaterials which need to improve cell activity through gene expression changes and activation of cell signaling.

• Tuberculosis and Respiratory Diseases
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• v.54 no.4
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• pp.367-377
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• 2003

Background : It is well known that only 10% of those infected with Mycobacterium tuberculosis actually develop clinical disease, indicating the existence of host genetic factors regulating disease expression. In this study, we investigated HLA-DRB1 and -DQB1 gene polymorphisms in Korean patients with pulmonary tuberculosis (PTB). Methods : HLA-DRB1 and -DQB1 gene polymorphisms were investigated in 67 PTB patients without previous treatment history, 38 drug-sensitive (DS) and 29 multidrug-resistant (MDR) cases, and 200 healthy controls. HLA-DRB1 typing was done using reverse SSO (sequence specific oligonucleotide) and PCR-SSCP (single strand conformational polymorphism) methods and DQB1 typing was done using PCR-RFLP (restriction fragment length polymorphism), PCR-SSCP and PCR-SSP (sequence specific primer) methods. Results : Among the PTB patients, MDR-TB cases showed frequencies of DRB1*0701 and *08032 increased by about two-fold compared to those of normal controls, and likewise for their associated DQB1 alleles, DQB1*0202 and *0601 (15.5% vs. 34.5%, p=0.01). The frequency of HLA-DQB1*0609 was significantly increased in PTB patients (4.0% vs. 14.9%, p=0.004), showing similar increases in both DS and MDR cases. There was also an association of HLA alleles with the clinical severity of the disease according to the extent of lung lesion. Significantly increased frequencies of DRB1*08032 (4.2% vs. 32.6%, p=0.007) and DQB1*0601 (12.5% vs. 34.9%, p=0.047) were observed in more advanced (moderately & far advanced/DS and far advanced/MDR), compared with less advanced (minimal/DS and moderately advanced/MDR) lung lesions. Although DRB1*0701, DQB1*0202 and DQB1*0609 showed significant increases in different subsets of the disease, these HLA alleles did not show consistent association with disease severity. Conclusion : HLA-DRB1*08032 and DQB1*0601 alleles were associated with genetic susceptibility to MDR-TB in Korean patients, and also with disease severity and progression of PTB.

• Journal of Korean Society of Environmental Engineers
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• v.22 no.5
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• pp.939-947
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• 2000

Enhanced biological phosphorus removal (EBPR) was performed in an anaerobic/aerobic sequencing batch reactor (SBR). Influent was a synthetic wastewater based on acetate as a carbon source. The sludge age and hydraulic retention time were kept at 10 days and 16 hrs, respectively, Phosphate release during the anaerobic period and phosphate uptake in aerobic period were increased gradually with time. and after about 200 days, steady-state operation could be achieved with complete removal of influent phosphate. Number distribution of microbial community in the sludge performing EBPR was investigated during the steady state operation. 17 rRNA targeted oligonucleotide probes were designed and slot hybridization technique was used to determine the number distribution of each microorganism. In the acetate fed SBR, rRNA belonging to the beta subclass of proteobacteria was the most dominant in total rRNA and rRNA matching to CTE probe was the second, rRNAs of Acinetobacter, Aeromonas and Pseudomonas, which are usually thought as phosphorus accumulating organisms in EBPR processes, constituted less than 10% of total rRNA. From this community analysis, it was inferred that microorganisms belong to the beta subclass of proteobacteia (BET) and CTE such as Rhodocyclus group were important in biological phosphorus removal. Therefore, the role of Acinetobacter, Aeromonas and Pseudomonas in the EBPR might have been overestimated.

• The korean journal of orthodontics
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• v.35 no.4 s.111
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• pp.312-319
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• 2005

Streptococcus mutans and Streptococcus sobrinus are major etiological agents in enamel demineralization around orthodontic appliances. This study was designed to examine the prevalence of these streptococci on orthodontic brackets in vivo using polymerase chain reaction. Four incisor brackets in the upper and lower arches were removed and collected from 80 patients at the time of debonding. The genomic DMA of adhered bacteria was extracted and each dextranase gene of S. mutans and S. sobrinus was amplified using the specific oligonucleotide primers. The results showed that the maxillary incisor brackets were colonized by both cariogenic streptococci to a somewhat higher degree than that taken from the mandible. The prevalence of S. mutans was $50.0\%$ on the maxillary incisor brackets and $33.8\%$ on the mandibular incisor brackets, and that of S. sobrinus was $17.5\%$ and $15.0\%$, respectively. Both species were detected on the maxillary incisor brackets of 7 patients $(8.8\%)$ and the mandibular incisor brackets of 5 patients $(6.3\%)$. These results suggest that cariogenic streptococci can adhere to the incisor brackets and may be resident species on the incisor brackets.

• Journal of Preventive Medicine and Public Health
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• v.32 no.1
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• pp.101-107
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• 1999

Objectives. To determine the effects of exposure to hexavalent chromium, 93 male Sprague-Dawley rats were exposed to hexavalent chromium solution. Methods. Rats were divided into 4 groups and exposed to 0.1ml of 0 mM, 0.4 mM, 2.0 mM, and 10.0 mM potassium chromate in the first experiment, and to 0.1 ml of 0 mM, 20 mM, 40 mM, and 80 mM in the second for consecutive 3 days by tracheal instillation. Three and 10 rats were the controls for the first and the second experiments, respectively. Lung tissues were then removed to measure the 8-hydroxydeoxyguanosine (8-OH-dG) level using the HPLC-ECD method, superoxide dismutase (SOD) activity using the cytochrome C method, and 8-hydroxyguanine endonuclease activity using the oligonucleotide nicking assay. Results. The results showed no significant linear relationship between chromium exposure level and 8-OH-dG level or 8-hydroxyguanine endonuclease activity. In the first experiment, 8-OH-dG level and 8-hydroxyguanine endonuclease activity increased in 0.4 mM group, and then decreased in 2.0 mM and 10.0 mM groups. The correlation coefficients between 8-OH-dG level and 8-hydroxyguanine endonuclease activity was statistically significant (P<0.01), and total SOD activity was elevated by chromium exposure in a dose-dependent manner (P<0.05). In contrast, there was no significant dose-response pattern or correlation in the secod experiment. Conclusions. Based on the fact that there was no linear relationship between chromium dose and 8-OH-dG level or activity of the repair enzyme, it seems unlikely that 8-OH-dG formation is the major mechanism of chromium carcinogenesis.

• Applied Biological Chemistry
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• v.50 no.4
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• pp.276-280
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• 2007

Buckwheat often causes severe allergic reactions in sensitive people. One of the major allergenic proteins in common buckwheat (Fagopyrum esculentum) has been found to be a BW10KD protein. In this study, we developed a PCR method to detect buckwheat ingredients in food using primers corresponding to the allergenic BW10KD gene. Five pairs of oligonucleotide primers successfully enabled PCR amplification of the specific regions of the genomic BW10KD DNA from buckwheat, but no amplification from seven other cereals and beans (barley, wheat, German millet, African millet, soybean, red bean, and black bean). The proposed PCR method was applied to analyze 12 processed foods (buckwheat flour, buckwheat noodle, buckwheat jelly, wheat noodle, instant noodle, black sesame gruels, sunsik, cookie, misutkaru, and three kinds of cereal); among them, only three samples including buckwheat flour, buckwheat noodle and buckwheat jelly showed a positive reaction to the detection. This PCR method was able to detect as little as 1 ng of common buckwheat DNA. This rapid and specific PCR method would be applicable to detect allergenic buckwheat ingredients in food.

• Journal of Environmental Science International
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• v.17 no.5
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• pp.555-564
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• 2008

The bacterial community structure in biological activated carbon (BAC) process in drinking water treatment plant was investigated by Fluorescent in situ Hybridization (FISH) with rRNA-targeted oligonucleotide probe. Samples were collected at different three points in BAC process every month for one year. They were hybridized with a probe specific for the alpha, beta, gamma subclass of the class Proteobacteria, Cytophaga-Flavobacteria group and Gram-positive high G+C content (HGC) group. Total numbers of bacteria in BAC process counted by 4',6-diamidino-2-phenylindole (DAPI) staining were $5.4{\times}10^{10}$ (top), $4.0{\times}10^{10}$ (middle) and $2.8{\times}10^{10}$ cells/ml (bottom). The number of the culturable bacteria was from $1.0{\times}10^7$ to $3.6{\times}10^7$ cells/ml and the culturability was about 0.05%. The faction of bacteria detectable by FISH with the probe EUB338 was about 83% of DAPI counts. Gamma and alpha subclass of the class Proteobacteria were predominant in BAC process and their ratios were over 20% respectively. In top and middle, alpha, beta and gamma subclass of the class Proteobacteria competed with each other and their percentages was changed according to the season. In bottom, gamma subclass of the class Proteobacteria was predominant all through the year. It could be successfully observed the seasonal distribution of bacterial community in biological activated carbon process using FISH.