44 research outputs found
IS6110-Restriction Fragment Length Polymorphism and Spoligotyping Analysis of Mycobacterium tuberculosis Clinical Isolates for Investigating Epidemiologic Distribution in Korea
The Beijing family of Mycobacterium tuberculosis has been emerging in the world. However, there are few nationwide data of genotypic distribution in Korea. This study aimed to identify the genotypic diversity of clinical isolates of M. tuberculosis and to demonstrate the population of Beijing family in Korea. We collected 96 clinical M. tuberculosis isolates from 11 university hospitals nationwide in Korea from 2008 to 2009. We observed 24 clusters in IS6110-RFLP analysis and 19 patterns in spoligotyping. Seventy-five isolates were confirmed to be Beijing family. Two isolates of the K strain and 12 isolates of the K family strain were also found. We found that drug resistance phenotypes were more strongly associated with Beijing family than non-Beijing family (P=0.003). This study gives an overview of the distribution of genotypes of M. tuberculosis in Korea. These findings indicate that we have to pay more attention to control of M. tuberculosis strains associated with the Beijing family
Estimation of Nationwide Vaccination Coverage and Comparison of Interview and Telephone Survey Methodology for Estimating Vaccination Status
This study compared interview and telephone surveys to select the better method for regularly estimating nationwide vaccination coverage rates in Korea. Interview surveys using multi-stage cluster sampling and telephone surveys using stratified random sampling were conducted. Nationwide coverage rates were estimated in subjects with vaccination cards in the interview survey. The interview survey relative to the telephone survey showed a higher response rate, lower missing rate, higher validity and a less difference in vaccination coverage rates between card owners and non-owners. Primary vaccination coverage rate was greater than 90% except for the fourth dose of DTaP (diphtheria/tetanus/pertussis), the third dose of polio, and the third dose of Japanese B encephalitis (JBE). The DTaP4: Polio3: MMR1 fully vaccination rate was 62.0% and BCG1:HepB3:DTaP4:Polio3:MMR1 was 59.5%. For age-appropriate vaccination, the coverage rate was 50%-80%. We concluded that the interview survey was better than the telephone survey. These results can be applied to countries with incomplete registry and decreasing rates of landline telephone coverage due to increased cell phone usage and countries. Among mandatory vaccines, efforts to increase vaccination rate for the fourth dose of DTaP, the third dose of polio, JBE and regular vaccinations at recommended periods should be conducted in Korea
The Therapeutic Effect of STAT3 Signaling-Suppressed MSC on Pain and Articular Cartilage Damage in a Rat Model of Monosodium Iodoacetate-Induced Osteoarthritis
Osteoarthritis (OA) is a degenerative disease that induces pain, cartilage deformation, and joint inflammation. Mesenchymal stem cells (MSCs) are potential therapeutic agents for treatment of OA. However, MSC therapy can cause excessive inflammation. Signal transducer and activator of transcription 3 (STAT3) modulates secretion of many proinflammatory cytokines. Experimental OA was induced by intra-articular (IA) injection of monosodium iodoacetate (MIA) to the right knee of rats. MSCs from OA patients (OA-MSCs) were treated with STA21, a small molecule that blocks STAT3 signaling, by IA or intravenous (IV) injection after MIA injection. Pain severity was quantified by assessment of secondary tactile allodynia using the von Frey assessment test. Cartilage degradation was measured by microcomputed tomography image analysis, histological analysis, and the Mankin score. Protein and gene expression was evaluated by enzyme-linked immunosorbent assay, immunohistochemistry, and real-time polymerase chain reaction. MSCs increased production of proinflammatory cytokines under inflammatory conditions. STA21 significantly decreased expression of these proinflammatory molecules via inhibition of STAT3 activity but increased gene expression of molecules related to migration potential and immunomodulation in OA-MSCs. STAT3-inhibited OA-MSCs administrated by IV or IA injection decreased pain severity and cartilage damage in rats with MIA-induced OA rats by decreasing proinflammatory cytokines in the joints. Combined IA and IV-injected STAT3-inhibited OA-MSCs had an additive effect of pain relief in MIA-induced OA rats. STAT3 inhibition may optimize the therapeutic activities of MSCs for treating OA by attenuating pain and progression of MIA by inhibiting inflammation and cartilage damage
Identification of gut dysbiosis in axial spondyloarthritis patients and improvement of experimental ankylosing spondyloarthritis by microbiome-derived butyrate with immune-modulating function
IntroductionDysbiosis is an environmental factor that affects the induction of axial spondyloarthritis (axSpA) pathogenesis. In the present study, we investigated differences in the gut microbiota of patients with axSpA and revealed an association between specific gut microbiota and their metabolites, and SpA pathogenesis.MethodUsing 16S rRNA sequencing data derived from feces samples of 33 axSpA patients and 20 healthy controls (HCs), we examined the compositions of their gut microbiomes.ResultsAs a result, axSpA patients were found to have decreased α-diversity compared to HCs, indicating that axSpA patients have less diverse microbiomes. In particular, at the species level, Bacteroides and Streptococcus were more abundant in axSpA patients than in HCs, whereas Faecalibacterium (F). prausnitzii, a butyrate-producing bacteria, was more abundant in HCs. Thus, we decided to investigate whether F. prausnitzii was associated with health conditions by inoculating F. prausnitzii (0.1, 1, and 10 μg/mL) or by administrating butyrate (0.5 mM) into CD4+ T cells derived from axSpA patients. The levels of IL-17A and IL-10 in the CD4+ T cell culture media were then measured. We also assessed osteoclast formation by administrating butyrate to the axSpA-derived peripheral blood mononuclear cells. The CD4+ IL-17A+ T cell differentiation, IL-17A levels were decreased, whereas IL-10 was increased by F. prausnitzii inoculation. Butyrate reduced CD4+ IL-17A+ T cell differentiation and osteoclastogenesis.DiscussionWe found that CD4+ IL-17A+ T cell polarization was reduced, when F. prausnitzii or butyrate were introduced into curdlan-induced SpA mice or CD4+ T cells of axSpA patient. Consistently, butyrate treatment was associated with the reduction of arthritis scores and inflammation levels in SpA mice. Taken together, we concluded that the reduced abundance of butyrate-producing microbes, particularly F. prausnitzii, may be associated with axSpA pathogenesis
Nonlinear Random Response Analyses of Panels Considering Transverse Shear Deformations under Combined Thermal and Acoustic Loads
The panel structures of flight vehicles at supersonic or hypersonic speeds are subjected to combined thermal, acoustic, and aerodynamic loads. Because of the combined thermal and acoustic loads, the panel structure may exhibit nonlinear random vibration responses, such as the snap-through phenomenon and random vibrations. These unique dynamic behaviors of the panel structure under combined thermal and acoustic loads can result in serious damage or fatigue failure of the panel structures of high-speed flight vehicles. This study investigates the nonlinear random responses of thin and thick panels under combined thermal and acoustic loads. The panels are modeled based on the first-order shear deformation theory (FSDT) to account for transverse shear deformations. The von-Karman nonlinear strain–displacement relationship is used for geometric nonlinearity in the out-of-plane direction of the panel. The thermal load distribution is assumed to be constant in the thickness direction of the panel. The random acoustic load is represented as stationary White–Gaussian random pressure with zero mean and uniform magnitude over the panels. Static and dynamic equations are derived using the principle of virtual work and the nonlinear finite element method. A thermal postbuckling analysis is conducted using the Newton–Raphson method, and the dynamic nonlinear equations are solved using the Newmark-β time integration method. In the present numerical analyses, the snap-through responses for both the thin and thick panels are investigated, and the results indicate that the loading conditions that cause snap-through are different for thin and thick panels
Variation in Seed Quality, Seedling Growth and Biomass Allocation of One-year-old Siberian Larch ( Larix sibirica Ledeb.) Seedlings Grown in Different Conditions from Diverse Seed Sources of Mongolia
The rehabilitation of degraded forests in Mongolia showed very low success and the total area
reforested successfully represents only 5% of the total forest lost. One of the reasons for such poor
results may be low quality of planting stock due to the poor quality of seeds. The objectives of this
study were to determine seed source variation in seed quality, to examine their growth and biomass
allocation in one-year-old seedlings of Siberian larch from diverse seed sources, and to select the most
promising seed sources for reforestation of degraded forest lands in Mongolia. Siberian larch seedlings
from eight geographically different seed sources were grown at an open nursery and in greenhouse
nursery conditions, and seedlings were subjected to growth and biomass allocation measurements at
the end of the
fi
rst growing season. It was found that there were signi
fi
cant differences in seed quality,
growth and biomass allocation among the seed sources in both growth conditions. Overall, Sources
No.3 (Tuul river) and No.4 (Mungun) showed the best growth performances and biomass accumulation
at open nursery and greenhouse nursery conditions, respectively. Source No.1 (Ovorkhangai) had the
lowest performances in both growth conditions for all measured variables. On the other hand, seedlings
grown in the greenhouse nursery conditions had more intensive growth and accumulated more biomass
compared to seedlings grown in open nursery conditions. However, the proportion of biomass of the
roots at open nursery grown seedlings was higher than that of greenhouse grown seedlings, which may
indicate a more promising survival rate after
fi
eld transplanting
Theoretical Study on Targeted Penetration of Influenza A Virus to Induce the Destruction of Cancer Cell
Oncolytic virus is used for targeted cancer therapy and it is functionalized to target and destroy cancer cell by replication of virus in the cell . Although oncolytic virus was expected to have low side effect due to application of autoimmunity, accurate targeting of cancer cell and high-efficiency of treatment have not been achieved. In this study, hemagglutinin (HA), the surface protein of Influenza A virus, was modified to target pancreatic cancer cell. Improvement of the targeting accuracy was expected by coating DOTAP (N-[1-(2,3-dioleoyloxy)propyl]-N,N,N-trimethylammonium) on the surface of influenza A virus. For this theoretical study, coarse-grained molecular dynamics was employed, and cancer cell membrane was modeled with four different lipids, cholesterol and sialic acid, which was receptor of influenza A virus. Cancer cell membrane was shown stronger adsorption with HA than normal cell due to interaction between lysine and arginine of HA, which were positively charged, and POPS of cancer cell. Oncolytic virus coated with DOTAP was shown effective due to strong adsorption on the cancer cell membrane originated from charge interaction between DOTAP and POPS
Development of Thermal Nanoimprinting-based Process for the Fabrication of Practical Triboelectric Nanogenerator
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Prediction of abundance of forest flies (Diptera) according to climate scenarios RCP 4.5 and RCP 8.5 in South Korea
This aim of this study was to project the future changes of abundance of dipteran families due to climate change using nationwide fly data of surveys conducted for 4 years from 2006 at 295 sites (forests). Most analyzed families (22) showed characteristics that are expected in normal distribution along a temperature gradient in which the maximum value occurs at an optimum temperature. Temperature changes were projected by Representative Concentration Pathways (RCP) 4.5 and 8.5 climate scenarios, and abundance in two periods, 2011s2015 and 2056–2065, was projected using the mean value of abundance in each temperature range. It was predicted that among the 22 families analyzed, the abundance of 21 will decrease and one will increase due to a temperature increase. The family abundance change rates were significantly correlated with temperature. This pattern was used for qualitative prediction (decrease or increase) of other families (> 1% of occurrence). This qualitative prediction also showed that 26 families, except one, were forecasted to decrease