• Journal of Korean society of Dental Hygiene
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• v.9 no.2
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• pp.111-124
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• 2009

This study analyzes through the review of literature and laws the exposure time, clinical frequency, and radiation exposure of intraoral and extraoral radiography as well as of panoramic radiography performed by dental hygienists in dental clinics, compares the dental radiology curriculums of radiological science and dental hygiene departments, and proposes the expansion of dental hygienists' radiography operations. The radiology curriculums were compared between the radiological science and dental hygiene departments of colleges. For new analysis by radiography for dental diagnosis, the exposure time, radiation absorbed dose, effective dose, and number of days of natural radiation were compared by the type of oral radiation films and radiographical techniques proposed by domestic and international studies. The exposure time of panoramic radiography is 15 seconds and it takes about two minutes for completion, whereas the exposure time of the standard radiography is 0.2~0.8 seconds and it takes 10 times longer for completion of the radiography of full mouth than the panoramic radiography. The standard radiography can cause distortions of radiation at severely curved parts of dental arch and palatopharyngeal reflex. However, panoramic radiography can be performed even for lock jaw patients, causes less inconvenience to patients and is much simpler than the standard radiography. The percentage of dental clinics where radiography is performed by dental hygienists was 92.0%, and the percentage of standard film radiography by dental hygienists was 98% whereas the percentage of panoramic radiography by dental hygienists was 92%. For the absorbed dose which is an indicator of radiation exposure, the When the effective dose which is an indicator of the danger of radiation exposure was converted to the number of days of natural radiation, it was 3.3 days for panoramic radiography, but 13.9 days for the full mouth standard radiography by bisecting angle technique which was 4.2 times longer than the panoramic radiography. There were two colleges that had a dental radiology course with two credits in the departments of radiological science. The credits for dental radiology courses in the department of dental hygiene ranged varied by college, ranging from 3 to 8; on average, the theory course was 2.2 credits and the practice course was 2.02 credits. To summarize the above results, the percentage of dental clinics where panoramic radiography is performed by dental hygienists under the guidance of dentists is high. Panoramic radiography has become an essential facility for dental clinics. It is faster than standard film radiography and less dangerous due to low radiation exposure. Panoramic radiography is a simple mechanical job that does not require training of oral radiography by radiotechnologist. Because panoramic radiography is one of major operations which must be performed at all times in dental clinics, it must be designated as intraoral technique rather than extraoral technique, or legalized for inclusion in the scope of operations of dental hygienists.

• Korean Journal of Microbiology
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• v.30 no.5
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• pp.360-365
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• 1992

Clinical isolates of 8 ofloxacin resistant Staphylococcus auresu (ORSA) were subjected to MIC test, Southern analysis on gyrA locus and nucleotide sequence analysis of 290 bp of gyrA gene (gyrA-290) spanning amino acid 26 to 121 in order to understand the mechanism of quinolone resistance in Staphylococcus aureus. ORSAs showed highlevel resistance against quinolones (8-250 fold increase of MICs) and also significant resistance agianst ${\beta}-lactams$ (2-32 fold increase of MICs). However, ORSs did not show any change in sensitivity agianst vancomycin. Southern analysis of ORSAs with HindIII, PstI and AluI revealed RFLPs on gyrA locus. In order to further analyze the gyrA gene, gyrA-290 was amplified by PCR and cloned to pTZ vector. Subsequent nucleic acid sequence analysis of gyrA-290 demonstrated a point mutation of C to T resulting amino acid change of Ser-84 to Leu-84 in all 8 ORSA strains. The substitution at 84th amino acid of tyrase A might confer one mechanism of high level quinolone resistance in Staphylococcus aureus.

• Journal of Microbiology and Biotechnology
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• v.20 no.10
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• pp.1450-1456
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• 2010

Accurate and rapid diagnosis of Pandemic Influenza A/H1N1 2009 virus (H1N1 2009) infection is important for the prevention and control of influenza epidemics and the timely initiation of antiviral treatment. This study was conducted to evaluate the performance of several diagnostic tools for the detection of H1N1 2009. Flocked nasopharyngeal swabs were collected from 254 outpatients of suspected H1N1 2009 during October 2009. This study analyzed the performances of the RealTime Ready Inf A/H1N1 Detection Set (Roche), Influenza A (H1N1) Real-Time Detection Kit (Bionote), Seeplex Influenza A/B OneStep Typing Set [Seeplex Reverse Transcriptase PCR (RT-PCR)], BinaxNow Influenza A & B Test Kit [Binax Rapid Antigen Test (RAT)], and SD BIOLINE Influenza Ag kit (SD RAT). Roche and Bionote real-time RT-PCR showed identical results for the H1N1 2009 hemagglutinin gene. Compared with real-time RT-PCR, the sensitivities and specificities were 83.7% and 100% for Seeplex RT-PCR, 64.5% and 94.7% for Binax RAT, and 69.5% and 100% for SD RAT. The sensitivities of Seeplex RT-PCR, Binax RAT, and SD RAT in patients aged over 21 years were 73.7%, 47.4%, and 57.9%, respectively. The sensitivities of Seeplex RT-PCR, Binax RAT, and SD RAT on the day of initial symptoms were mostly lower (68.8%, 56.3%, and 31.3%, respectively). In conclusion, multiplex RT-PCR and RAT for the detection of H1N1 2009 were significantly less sensitive than real-time RT-PCR. Moreover, a negative RAT may require more sensitive confirmatory assays, because it cannot be ruled out from influenza infection.

• IMMUNE NETWORK
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• v.7 no.3
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• pp.149-157
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• 2007

Background: The microsatellites within human leukocyte antigen (HLA) region show considerable polymorphism and strong linkage disequilibrium (LD) with HLA alleles. These microsatellites have been used for genetic analysis including disease mapping to understand susceptibility to autoimmune and infectious diseases. Also, use of microsatellites has recently been proposed as an approach for identifying non-HLA markers within the HLA region that could function as transplantation determinants and for the selection of potential donors for transplantation. Methods: To analyse the frequency of five microsatellites in the Korean population, genotyping for polymorphisms at five microsatellites markers (BAT2, MIB, DQCAR, D6S105 and TNFd) within HLA region was performed on 143 healthy Korean controls. Results: The most frequent genotype shown in healthy Korean controls were BAT2 8 (153 bp, 42.7%), MIB 1 (326 bp, 40.6%), DQCAR 3 (188 bp, 38.5%), D6S105 7 (126 bp, 58.0%) and TNFd 3 (128 bp, 58.0%). And common two-loci haplotypes were found as MIB 1-HLA-B*62 (HF: 10.6%), MIB 6-HLA-B*44 (HF: 7.8%), DQCAR 3-HLA-DRB1*13 (HF: 8.5%), TNFd 5-HLA-B*62 (HF: 7.8%) and D6S105 7-HLA-A*02 (HF: 16.2%). Conclusion: These data might provide useful information on the microsatellites markers with HLA region in Korean population and be helpful in further defining the clinical impact of these microsatellites.

• Journal of Preventive Medicine and Public Health
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• v.49 no.3
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• pp.165-175
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• 2016

Objectives: The present study was undertaken to study the maternal risk factors for preterm birth (PTB) and low birth weight (LBW) with a special emphasis on assessing the proportions of maternal genitourinary and periodontal infections among Indian women and their association with adverse pregnancy outcomes. Methods: A hospital-based prospective study comprising 790 pregnant women visiting the obstetrics clinic for a routine antenatal check-up was undertaken. Once recruited, all study participants underwent clinical and microbiological investigations for genitourinary infections followed by a dental check-up for the presence of periodontitis. The study participants were followed up until their delivery to record the pregnancy outcomes. Infectious and non-infectious risk factors for PTB and LBW were assessed using univariate and multivariate Cox regression analysis. Independent risk factors for PTB and LBW were reported in terms of adjusted relative risk (ARR) with the 95% confidence interval (CI). Results: Rates of PTB and LBW in the study population were 7.6% and 11.4%, respectively. Previous preterm delivery (ARR, 5.37; 95% CI, 1.5 to 19.1), periodontitis (ARR, 2.39; 95% CI, 1.1 to 4.9), Oligohydramnios (ARR, 5.23; 95% CI, 2.4 to 11.5), presence of Nugent's intermediate vaginal flora (ARR, 2.75; 95% CI, 1.4 to 5.1), gestational diabetes mellitus (ARR, 2.91; 95% CI, 1.0 to 8.3), and maternal height <1.50 m (ARR, 2.21; 95% CI, 1.1 to 4.1) were risk factors for PTB, while periodontitis (ARR, 3.38; 95% CI, 1.6 to 6.9), gestational hypertension (ARR, 3.70; 95% CI, 1.3 to 10.8), maternal height <1.50 m (ARR, 2.66; 95% CI, 1.3 to 5.1) and genital infection during later stages of pregnancy (ARR, 2.79; 95% CI, 1.2 to 6.1) were independent risk factors for LBW. Conclusions: Our study findings underscore the need to consider screening for potential genitourinary and periodontal infections during routine antenatal care in developing countries.

• Microbiology and Biotechnology Letters
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• v.43 no.4
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• pp.357-366
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• 2015

Quorum sensing (QS) is involved in the process of cell-to-cell communication and as a gene regulatory mechanism, which has been implicated in bacterial pathogenicity. Bacteria use this QS system to control a variety of physiological processes. In this study, pomegranate (Punica granatum L.) peel extract (PPE) was first screened for its ability to inhibit QS in bio-reporter strains (Chromobacterium violaceum and C. violaceum CV026). Next, the ability of PPE to inhibit swimming motility and biofilm formation was examined in Y. enterocolitica. Additionally, changes in the expression of specific genes involved in the synthesis of the N-acylhomoserine lactones (AHLs; yenI and yenR) and in the flagellar regulon (fliA, fleB and flhDC) were evaluated by reverse transcription (RT)-PCR. The results show that PPE specifically inhibited and reduced QS-controlled violacein production by 78.5% in C. violaceum CV026, and decreased QS-associated biofilm formation and swimming motility in Y. enterocolitica without significantly affecting bacterial growth. These inhibitory effects were also associated with the down-regulation of gene expression involved in the synthesis of AHLs and in motility. Our results suggest that PPE could be a potential therapeutic agent to prevent enteropathogens in humans, as well as highlight the need to further investigate the in vivo properties of PPE for clinical applications.

• Journal of Microbiology and Biotechnology
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• v.24 no.3
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• pp.363-370
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• 2014

Campylobacter jejuni is a prevalent foodborne pathogen worldwide. Human infection by C. jejuni primarily arises from contaminated poultry meats. Genes expressed in vivo may play an important role in the pathogenicity of C. jejuni. We applied an immunoscreening method, in vivo-induced antigen technology (IVIAT), to identify in vivo-induced genes during human infection by C. jejuni. An inducible expression library of genomic proteins was constructed from sequenced C. jejuni NCTC 11168 and was then screened using adsorbed, pooled human sera obtained from clinical patients. We successfully identified 24 unique genes expressed in vivo. These genes were implicated in metabolism, molecular biosynthesis, genetic information processing, transport, and other processes. We selected six genes with different functions to compare their expression levels in vivo and in vitro using real-time RT-PCR. The results showed that the selected six genes were significantly upregulated in vivo but not in vitro. In short, these identified in vivo-induced genes may contribute to human infection of C. jejuni, some of which may be meaningful vaccine candidate antigens or diagnosis serologic markers for campylobacteriosis. IVIAT may present a significant and efficient method for understanding the pathogenicity mechanism of Campylobacter and for finding targets for its prevention and control.

• Microbiology and Biotechnology Letters
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• v.47 no.3
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• pp.465-472
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• 2019

Candida albicans is an opportunistic human pathogen that causes infections. Candidiasis is often related to antifungal resistance because the pathogen has the ability to form biofilms. In a previous study, we found that the Salvia miltiorriza ethanol extract demonstrated anticandidal activity by altering membrane permeability and inhibiting the cell wall synthesis in C. albicans. Our results here demonstrate that $78{\mu}g/ml$ of the S. miltiorriza extract significantly diminished the early stage biofilms formed by 10 clinical C. albicans isolates by 51.3%; this was analyzed by 2,3-Bis-(2-methoxy-4-nitro-5-sulfophenyl)-2H-tetrazolium-5-carboxanilide salt (XTT) reduction assay. The effect of the S. miltiorrhiza extract on the adhesion of C. albicans cells to polystyrene plates and germ tube formation was examined via microscopic investigation. Although the density of the adhered cells was remarkably reduced up on incubation with $39{\mu}g/ml$ S. miltiorrhiza extract, germ tube formation by C. albicans was rarely affected. Quantitative real-time PCR analysis showed that the S. miltiorrhiza extract downregulated the expression of C. albicans hypha-specific genes, EAP1 by 34.7% (p < 0.001), ALS1 by 45.0% (p < 0.001), ALS3 by 48.1% (p < 0.001), and ECE1 by 21.3% (p = 0.006), respectively. Our data suggest that the S. miltiorrhiza ethanol extract significantly inhibited the early stage of biofilm formation by C. albicans by interfering with cell adhesion, by downregulating EAP1, ALS1 and ALS3, and presumably by modifying the cell wall and membrane structure.

• Journal of Korean Neurosurgical Society
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• v.64 no.5
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• pp.705-715
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• 2021

Objective : Through our previous clinical trials, the demonstrated therapeutic effects of MSC in chronic spinal cord injury (SCI) were found to be not sufficient. Therefore, the need to develop stem cell agent with enhanced efficacy is increased. We transplanted enhanced Wnt3-asecreting human mesenchymal stem cells (hMSC) into injured spines at 6 weeks after SCI to improve axonal regeneration in a rat model of chronic SCI. We hypothesized that enhanced Wnt3a protein expression could augment neuro-regeneration after SCI. Methods : Thirty-six Sprague-Dawley rats were injured using an Infinite Horizon (IH) impactor at the T9-10 vertebrae and separated into five groups : 1) phosphate-buffered saline injection (injury only group, n=7); 2) hMSC transplantation (MSC, n=7); 3) hMSC transfected with pLenti vector (without Wnt3a gene) transplantation (pLenti-MSC, n=7); 4) hMSC transfected with Wnt3a gene transplantation (Wnt3a-MSC, n=7); and 5) hMSC transfected with enhanced Wnt3a gene (1.7 fold Wnt3a mRNA expression) transplantation (1.7 Wnt3a-MSC, n=8). Six weeks after SCI, each 5×10⁵ cells/15 µL at 2 points were injected using stereotactic and microsyringe pump. To evaluate functional recovery from SCI, rats underwent Basso-Beattie-Bresnahan (BBB) locomotor test on the first, second, and third days post-injury and then weekly for 14 weeks. Axonal regeneration was assessed using growth-associated protein 43 (GAP43), microtubule-associated protein 2 (MAP2), and neurofilament (NF) immunostaining. Results : Fourteen weeks after injury (8 weeks after transplantation), BBB score of the 1.7 Wnt3a-MSC group (15.0±0.28) was significantly higher than that of the injury only (10.0±0.48), MSC (12.57±0.48), pLenti-MSC (12.42±0.48), and Wnt3a-MSC (13.71±0.61) groups (p<0.05). Immunostaining revealed increased expression of axonal regeneration markers GAP43, MAP2, and NF in the Wnt3a-MSC and 1.7 Wnt3a-MSC groups. Conclusion : Our results showed that enhanced gene expression of Wnt3a in hMSC can potentiate axonal regeneration and improve functional recovery in a rat model of chronic SCI.

• Journal of Microbiology and Biotechnology
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• v.31 no.11
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• pp.1583-1590
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• 2021

Studies have demonstrated that PE_PGRS45 is constitutively expressed under various environmental conditions (such as nutrient depletion, hypoxia, and low pH) of the in vitro growth conditions examined, indicating that PE_PGRS45 protein is critical to the basic functions of Mycobacterium tuberculosis. However, there are few reports about the biochemical function and pathogenic mechanism of PE_PGRS45 protein. The fact that this M. tuberculosis gene is not easily expressed in E. coli may be mainly due to the high content of G+C and the use of unique codons. Fusion tags are indispensable tools used to improve the soluble expression of recombinant proteins and accelerate the characterization of protein structure and function. In the present study, His6, Trx, and His6-MBP were used as fusion tags, but only MBP-PE_PGRS45 was expressed solubly. The purification using His6-MBP tag-specific binding to the Ni column was easy to separate after the tag cleavage. We used the purified PE_PGRS45 to immunize New Zealand rabbits and obtained anti-PE_PGRS45 serum. We found that the titer of polyclonal antibodies against PE_PGR45 was higher than 1:256000. The result shows that purified PE_PGRS45 can induce New Zealand rabbits to produce high-titer antibodies. In conclusion, the recombinant protein PE_PGRS45 was successfully expressed in E. coli and specific antiserum was prepared, which will be followed by further evaluation of these specific antigens to develop highly sensitive and specific diagnostic tests for tuberculosis.