Publications by authors named "Seon Ho Lee"

36 Publications

The Effect of Oxygen Content in Binderless Cokes for High-Density Carbon Blocks from Coal Tar Pitch.

Materials (Basel) 2021 Apr 7;14(8). Epub 2021 Apr 7.

Fuel Cell Laboratory, Korea Institute of Energy Research (KIER), Daejeon 34129, Korea.

High-density carbon blocks are much lighter than metals and have excellent mechanical properties and are one of the materials garnering attention to replace existing metal parts. In this study, a binderless coke was produced by changing the flow rates of nitrogen and air as a carrier gas during heat treatment of coal tar pitch and using this, a green body was formed at 150 MPa and carbonized to produce a high-density carbon block. We express the binderless coke produced in this way by N10A0, N7A3, N5A5, N3A7, N0A10 according to the ratio of nitrogen and air, and in the case of carbon block, we have added CB in front of it. We then considered the effect of oxygen content in the binderless cokes on the optical, chemical, and mechanical properties. It was observed that the produced binderless cokes develop into a dense mosaic structure with a small particle size as the air flow rate increased. To survey the change in oxygen content of the produced binderless coke, O1s and C1s regions were measured using X-ray photoelectric spectroscopy (XPS), and O1s/C1s was calculated. The O1s/C1s ratio steadily increased as the air flow rate increased, and in the case of N0A10, it increased about twice as much as that of N10A0 to 11.20%. β-resin has a very large effect on the mechanical strength of the carbon block in addition to air in the pitch. And in the case of CB-N0A10, it shows the best mechanical strength with a density of 1.72 g/cm, bending strength of 87 MPa, and shore hardness of 93 HSD.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3390/ma14081832DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8067829PMC
April 2021

3D-printed tablets using a single-step hot-melt pneumatic process for poorly soluble drugs.

Int J Pharm 2021 Feb 22;595:120257. Epub 2021 Jan 22.

BK21 FOUR Team and Integrated Research Institute for Drug Development, College of Pharmacy, Dongguk University, Gyeonggi 10326, Republic of Korea. Electronic address:

Main purpose was to evaluate the applicability of a 3D-printer equipped with a hot-melt pneumatic dispenser as a single-step process to prepare tablet dosage forms. Dutasteride, a poorly water-soluble drug, was selected as a model drug. Soluplus®, Kollidon® VA 64, Eudragit® E PO, and hydroxypropyl cellulose (HPC) were premixed as bulking agents prior to printing. Differential scanning calorimetry (DSC), powder X-ray diffraction (PXRD), and thermogravimetric analysis (TGA) were utilized to evaluate the physicochemical properties of the 3D-printed tablets. Moreover, different geometries were designed to correlate the surface area/volume (SA/V) of the tablets with respect to their release profiles. As a result, printed dutasteride was confirmed to be in an amorphous state and not recrystallized even after the accelerated storage stability. Out of the four bulking agents, Kollidon® VA 64, enhanced the dissolution of the printed dutasteride, reaching above 80% within 15 min. These results suggest that the hot-melt pneumatic dispenser was efficient in converting the solid state into an amorphous state, which significantly enhanced the dissolution. On the other hand, the tube-shaped 3D-printed tablet exhibited the fastest drug dissolution profile, which had the highest SA/V ratio in comparison to the cube, hemisphere, and pyramid shapes. These results confirm the dependency of the drug dissolution rate not only on its crystallinity but also on the surface area of the 3D-printed tablet. Therefore, a 3D-printer equipped with a hot-melt pneumatic dispenser possesses useful applicability in enhancing drug dissolution, especially for poorly water-soluble drugs, in a single-step process.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.ijpharm.2021.120257DOI Listing
February 2021

Surface oxidation of petroleum pitch to improve mesopore ratio and specific surface area of activated carbon.

Sci Rep 2021 Jan 14;11(1):1460. Epub 2021 Jan 14.

Fuel Cell Laboratory, Korea Institute of Energy Research (KIER), Daejeon, 34129, Republic of Korea.

In this study, surface oxidation of petroleum pitch was performed to enhance the thermal stability, specific surface area, and mesopore ratio of activated carbon. The oxygen uptake of the pitch by surface oxidation has a strong influence on the formation of the specific surface area and pore size of activated carbon. It was confirmed that the oxygen uptake from the surface to the inner side of the surface oxidized pitch was the highest at the temperature of 330 °C (IP330-AC), with a mesopore ratio of 63.35% and specific surface area of 1811 m g. The oxygen content of the surface oxidized pitch increased proportionately with the mesopore ratio in activated carbon. The specific surface area and mesopore ratio of IP330-AC were respectively 163% and 487% higher than those of petroleum-based commercial activated carbon (A-BAC), and 102% and 491% higher than those of coconut-based commercial activated carbon (P60).
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1038/s41598-020-80784-2DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7809199PMC
January 2021

Performance Evaluation of Automated Immunohematology Analyzer IH-500 for Blood Bank Testing.

Indian J Hematol Blood Transfus 2019 Oct 2;35(4):731-735. Epub 2019 May 2.

Department of Laboratory Medicine, University of Ulsan College of Medicine, Ulsan University Hospital, Bangujin-sunhwandoro 877, Dong-gu, Ulsan, 44033 Korea.

The automated immunohematology analyzer IH-500 (Bio-rad, Cressier FR, Switzerland) was developed recently for blood bank tests and this study evaluated performance of IH-500. 200 blood samples for ABO/Rh typing were collected. ABO/Rh typing results measured by IH-500 was compared with conventional manual methods. Antibody screening tests were performed with 100 samples using both IH-500 and the Ortho BioVue System, and results were compared. Antibody identification tests were conducted on 5 samples using both IH-500 and the Ortho BioVue System and results were compared. Crossmatching was performed with both IH-500 and conventional manual tube method using 4 patient serum samples and 10 blood cell donors, and 40 results were compared. Isoagglutinin titer of anti-A and anti-B was determined in 10 samples using both IH-500 and the automated analyzer Ortho AutoVue Innova and concordance rates were obtained. The concordance rates of ABO/Rh typing, antibody screening test, antibody identification test, and crossmatching between comparative manual methods and the IH-500 were all 100%. In the evaluation of isoagglutinin titer, 8 (80.0%) results out of 10 samples (80%) showed results within ± 1 titer between the IH-500 and the AutoVue Innova, which indicates the concordance rates of 80.0%. IH-500 reported results with two titers lower than Ortho AutoVue Innova in two samples. The IH-500 demonstrated good concordance rates and provided reliable results compared to comparative manual methods in the blood bank testing. IH-500 would be useful as a possible replacement for conventionally performed manual methods in blood bank testing.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1007/s12288-019-01127-4DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6825066PMC
October 2019

Distinct Clinical Features of Plasma Cell Myeloma Patients Exhibiting Dysmorphic Plasma Cells: Association with More Plasma Cells at Diagnosis.

Indian J Hematol Blood Transfus 2019 Oct 15;35(4):662-672. Epub 2019 Mar 15.

1Department of Laboratory Medicine, University of Ulsan College of Medicine, Ulsan University Hospital, 877 Bangeojin Sunhwan-doro, Dong-gu, Ulsan, 44033 Republic of Korea.

Dysmorphic plasma cells are occasionally found in bone marrow (BM) aspirates of plasma cell myeloma (PCM) patients. We retrospectively analyzed the incidences of significant dysmorphic plasma cells (SDPC) presentations and their associations with clinical features in PCM patients. Total 91 PCM patients diagnosed from January 2013 to December 2017 at author's institution were enrolled. SDPC presentation was determined as ≥ 5% (SDPC5) or ≥ 10% (SDPC10) among total PC and clinical features of PCM patients were compared with respect to SDPC presentation status. Incidence of SDPC5/SDPC10 presentation was 39.6%/18.7%. Patients with SDPC5/SDPC10 showed significantly more BM PC ( = 0.004/0.020) and higher incidences of gains ( = 0.022/0.001) and loss ( = 0.032 for SDPC10 only) at diagnosis than those without SDPC5/SDPC10. Patients with SDPC5/SDPC10 also showed significantly greater absolute BM PC (0.007/0.034 and 0.047/0.049 for 1st and 2nd follow-up, respectively) and serum M-protein (0.041/0.044 and 0.039/0.049 for 1st and 2nd follow-up, respectively) reductions after chemotherapy than those without SDPC5/SDPC10. SDPC5/SDPC10 presentation was confirmed as an independent predictor of BM PC ≥ 37.7% [hazard ratio (HR) 4.649/2.613,  = 0.005/0.039]. Our present study demonstrated that SDPC presentation would be an independent predictor of more BM PC at diagnosis in PCM patients. Associations between SDPC presentation and higher incidence of gains and loss, greater PC/serum monoclonal protein reductions after chemotherapy were also identified. Association between SDPC presentation and favorable treatment response should be evaluated in more comprehensive study.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1007/s12288-019-01112-xDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6825082PMC
October 2019

Comparison of High Sensitivity and Conventional Flow Cytometry for Diagnosing Overt Paroxysmal Nocturnal Hemoglobinuria and Detecting Minor Paroxysmal Nocturnal Hemoglobinuria Clones.

Ann Lab Med 2019 Mar;39(2):150-157

Department of Laboratory Medicine, University of Ulsan College of Medicine, Ulsan University Hospital, Ulsan, Korea.

Background: High sensitivity flow cytometry (HS-FCM) was recently developed for diagnosing paroxysmal nocturnal hemoglobinuria (PNH). We compared its performance with conventional flow cytometry (C-FCM) for diagnosing overt PNH and detecting minor (0.1-1%) PNH clones in aplastic anemia (AA)/low-grade myelodysplastic syndrome (MDS) patients.

Methods: C-FCM and HS-FCM were performed simultaneously on 41 samples from healthy controls and 23 peripheral blood samples from 15 AA/low-grade MDS and eight PNH patients, using a Navios flow cytometer (Beckman Coulter, Miami, FL, USA). Results were compared.

Results: No healthy control samples had PNH clone size >0.01%. For granulocytes, C-FCM detected a smaller PNH clone size than HS-FCM (mean difference: 0.7-1.7%). In AA/low-grade MDS patients, three samples showed >1% PNH clones with C-FCM but not with HS-FCM. Seven samples showed minor PNH clones by C-FCM, but HS-FCM showed negative results for all these samples. In PNH patients, C-FCM detected a smaller PNH clone size than HS-FCM (mean difference: 1.9-5.0%). For red blood cells, C-FCM detected a greater PNH clone size than HS-FCM (mean difference: 1.5%). In AA/low-grade MDS patients, C-FCM showed >1% PNH clones in six samples, but HS-FCM showed >1% PNH clones in none of the samples. C-FCM detected minor PNH clones in nine samples, but six of them were negative by HS-FCM. In PNH patients, C-FCM detected a greater PNH clone size than HS-FCM (mean difference: 2.5%).

Conclusions: HS-FCM can sensitively detect minor PNH clones and reduce false-positive C-FCM minor PNH clone cases in AA/low-grade MDS patients.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3343/alm.2019.39.2.150DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6240522PMC
March 2019

Description of Mycobacterium chelonae subsp. bovis subsp. nov., isolated from cattle (Bos taurus coreanae), emended description of Mycobacterium chelonae and creation of Mycobacterium chelonae subsp. chelonae subsp. nov.

Int J Syst Evol Microbiol 2017 Oct 12;67(10):3882-3887. Epub 2017 Sep 12.

Department of Biomedical Sciences, Microbiology and Immunology, Cancer Research Institute, Institute of Endemic Diseases, and Liver Research Institute, Seoul National University Medical Research Center (SNUMRC), Seoul National University College of Medicine, Seoul, Republic of Korea.

Three rapidly growing mycobacterial strains, QIA-37, QIA-40 and QIA-41, were isolated from the lymph nodes of three separate Korean native cattle, Hanwoo (Bos taurus coreanae). These strains were previously shown to be phylogenetically distinct but closely related to Mycobacterium chelonae ATCC 35752 by taxonomic approaches targeting three genes (16S rRNA, hsp6 and rpoB) and were further characterized using a polyphasic approach in this study. The 16S rRNA gene sequences of all three strains showed 99.7 % sequence similarity with that of the M. chelonae type strain. A multilocus sequence typing analysis targeting 10 housekeeping genes, including hsp65 and rpoB, revealed a phylogenetic cluster of these strains with M. chelonae. DNA-DNA hybridization values of 78.2 % between QIA-37 and M. chelonae indicated that it belongs to M. chelonae but is a novel subspecies distinct from M. chelonae. Phylogenetic analysis based on whole-genome sequences revealed a 95.44±0.06 % average nucleotide identity (ANI) value with M. chelonae, slightly higher than the 95.0 % ANI criterion for determining a novel species. In addition, distinct phenotypic characteristics such as positive growth at 37 °C, at which temperature M. chelonae does not grow, further support the taxonomic status of these strains as representatives of a novel subspecies of M. chelonae. Therefore, we propose an emended description of Mycobacterium chelonae, and descriptions of M. chelonae subsp. chelonae subsp. nov. and M. chelonae subsp. bovis subsp. nov. are presented; strains ATCC 35752(=CCUG 47445=CIP 104535=DSM 43804=JCM 6388=NCTC 946) and QIA-37 (=KCTC 39630=JCM 30986) are the type strains of the two novel subspecies.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1099/ijsem.0.002217DOI Listing
October 2017

Changes in ginsenoside patterns of red ginseng extracts according to manufacturing and storage conditions.

Food Sci Biotechnol 2017 12;26(6):1735-1741. Epub 2017 Jul 12.

1Department of Food Science and Technology, College of Life and Applied Sciences, Yeungnam University, 280 Daehak-Ro, Gyeongsan, Gyeongbuk 58541 Republic of Korea.

Although the pharmacological action of red ginseng is mostly generated by ginsenosides, contents of ginsenosides in manufactured extracts are still varying according to processing and storage conditions. Rg1, Rb1, and Rh1 levels significantly decreased overtime under pH adjustment and thermal treatment during storage, and these changes were exacerbated at lower pH and higher storage temperature. However, Rg3 level showed the opposite pattern compared to other ginsenosides. Rg3 level linearly increased at higher temperature and pH while significantly decreased at pH 2. Furthermore, Rg3 level constantly increased during storage. This is the first combined study on the effects of manufacturing and storage conditions on ginsenoside contents of red-ginseng-extract products. To minimize loss of major marker and bioactive compounds of red ginseng products during manufacturing processes and storage, it is recommended that red-ginseng-extracts be maintained at pH 6-8, sterilized at below 105 °C, and stored at below 25 °C.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1007/s10068-017-0149-4DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6049700PMC
July 2017

Mycobacterium paraintracellulare sp. nov., for the genotype INT-1 of Mycobacterium intracellulare.

Int J Syst Evol Microbiol 2016 Aug 17;66(8):3132-3141. Epub 2016 May 17.

Department of Biomedical Sciences, Microbiology and Immunology, Cancer Research Institute, Institute of Endemic Diseases, and Liver Research Institute, Seoul National University Medical Research Center (SNUMRC), Seoul National University College of Medicine, Seoul, Republic of Korea.

Three mycobacterial strains, isolated from independent Korean patients with pulmonary infections, belonging to the Mycobacterium intracellulare genotype 1 (INT-1) were characterized using a polyphasic approach. The sequences of the 16S rRNA gene and internal transcribed spacer 1 (ITS1) of the INT-1 strains were identical to those of Mycobacterium intracellulare ATCC 13950T. However, multilocus sequence typing (MLST) analysis targeting five housekeeping genes (hsp65, rpoB, argG, gnd and pgm) revealed the phylogenetic separation of these strains from M. intracellulare ATCC 13950T. DNA-DNA hybridization values of >70 % confirmed that the three isolates belong to the same species, while the values of <70 % between one of them and the type strains of M. intracellulare and Mycobacterium chimaera confirmed their belonging to a distinct species. In addition, phenotypic characteristics such as positive growth on MacConkey agar and in acidic broth culture, unique matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) MS profiles of lipids, and unique mycolic acids profiles further supported the taxonomic status of these strains as representatives of a novel species of the Mycobacterium avium complex named Mycobacterium paraintracellulare. The type strain is MOTT64T (=KCTC 29084T=JCM 30622T).
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1099/ijsem.0.001158DOI Listing
August 2016

Ligularia fischeri extract attenuates liver damage induced by chronic alcohol intake.

Pharm Biol 2016 Aug 22;54(8):1465-73. Epub 2016 Jan 22.

a Department of Food Science and Technology , Yeungnam University , Gyeongsan , Republic of Korea ;

Context Ligularia fischeri (Ledebour) Turcz. (Compositae) has been used as a leafy vegetable and in traditional medicine to treat hepatic disorder in East Asia. Objective The present study explores the antioxidant activity of LF aqueous extract on EtOH-induced oxidative stress accompanied by hepatotoxicity both in vitro and in vivo. Materials and methods In vitro study using the mouse liver NCTC-1469 cell line was conducted to estimate the cytotoxicity as well as the inhibitory effect of LF extract against alcohol-treated cell damage. In vivo study used an alcohol-fed Wister rat model orally administered EtOH (3.95 g/kg of body weight/d) with or without LF extract (100 or 200 mg/kg body weight) for 6 weeks. Serum and liver tissue were collected to evaluate hepatic injury and antioxidant-related enzyme activity. Results The EC50 value for the DPPH radical scavenging capacity of LF extract was 451.5 μg/mL, whereas the IC50 value of LF extract in terms of EtOH-induced reactive oxygen species (ROS) generation was 98.3 μg/mL without cell cytotoxicity. LF extract (200 mg/kg body weight) significantly reduced the triglyceride content of serum (33%) as well as hepatic lipid peroxidation (36%), whereas SOD activity was elevated three-fold. LF extract suppressed expression of CYP2E1 and TNF-α, and attenuated alcohol-induced abnormal morphological changes. Discussion and conclusion LF extract attenuated liver damage induced by alcoholic oxidative stress through inhibition of ROS generation, down-regulation of CYP2E1, and activation of hepatic antioxidative enzymes. Homeostasis of the antioxidative defence system in the liver by LF extract mitigated hepatic disorder following chronic alcohol intake.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3109/13880209.2015.1104701DOI Listing
August 2016

Mycobacterium anyangense sp. nov., a rapidly growing species isolated from blood of Korean native cattle, Hanwoo (Bos taurus coreanae).

Int J Syst Evol Microbiol 2015 Jul 13;65(7):2277-2285. Epub 2015 Apr 13.

Department of Biomedical Sciences, Microbiology and Immunology, Cancer Research Institute, and Institute of Endemic Diseases, Seoul National University Medical Research Center (SNUMRC), Seoul National University College of Medicine, Seoul 110-799, Republic of Korea.

From the whole blood of Korean native cattle, Hanwoo (Bos taurus coreanae), a previously undescribed, rapidly growing, scotochromogenic isolate of the genus Mycobacterium is reported. Its 16S rRNA gene sequence, and the sequences of three other genes (hsp65, recA and rpoB) were unique and phylogenetic analysis based on 16S rRNA gene sequence (1420 bp) placed the organism into the rapidly growing Mycobacterium group close to Mycobacterium smegmatis (98.5% sequence similarity). However, phylogenetic analyses based on three different gene sequences (hsp65, recA and rpoB) revealed its location to be distinct from the branch of rapidly growing species. Culture and biochemical characteristics were generally similar to those of Mycobacterium fortuitum. Unique matrix-assisted laser desorption ionization time-of-flight (MALDI-TOF) MS profiles of lipids, unique fatty acid profile, unique mycolic acids profiles and a low DNA-DNA relatedness to M. fortuitum (23.6%) and M. smegmatis (39.7%) strongly supported the taxonomic status of this strain as a representative of a novel species of rapidly growing mycobacteria named Mycobacterium anyangense. The type strain is strain QIA-38(T) ( = JCM 30275(T) = KCTC 29443(T)).
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1099/ijs.0.000255DOI Listing
July 2015

Modified transtibial versus anteromedial portal technique in anatomic single-bundle anterior cruciate ligament reconstruction: comparison of femoral tunnel position and clinical results.

Am J Sports Med 2014 Dec 30;42(12):2941-7. Epub 2014 Sep 30.

Department of Orthopedic Surgery, Ulsan University Hospital, University of Ulsan College of Medicine, Ulsan, Korea.

Background: Although several studies have compared a conventional transtibial technique with an anteromedial (AM) portal technique for single-bundle (SB) anterior cruciate ligament (ACL) reconstruction, no study to date has investigated whether the modified transtibial technique results in the femoral tunnel being in a similar anatomic position and produces similar clinical outcomes with those of the AM portal technique.

Purpose: To compare the clinical outcomes and femoral tunnel position of SB ACL reconstruction using a modified transtibial technique (creating a femoral tunnel with varus and internal rotation of the tibia as well as modification of the tibial tunnel orientation) with those of SB ACL reconstruction using an AM portal technique.

Study Design: Randomized controlled trial; Level of evidence, 1.

Methods: A total of 40 patients (40 knees) who underwent arthroscopic SB ACL reconstruction were included in this study. Patients were randomized using a computer-generated sequence into 2 groups: 20 patients by the modified transtibial technique (group 1) and 20 patients by the AM portal technique (group 2). Clinical evaluations included the 2000 International Knee Documentation Committee (IKDC) subjective knee score, Lysholm knee score, Tegner activity scale, Lachman test, pivot-shift test, 2000 IKDC knee examination, and KT-1000 arthrometer measurement. Three-dimensional computed tomography scans were analyzed according to the quadrant method, and the obliquity of the femoral tunnels in the coronal and sagittal planes and the size of the tunnel orifice were measured.

Results: All clinical parameters improved significantly after SB ACL reconstruction, with no between-group differences. The mean distance of the femoral tunnel center location from the posterior condylar surface (0.8% difference; P = .167) and from the Blumensaat line (2.1% difference; P = .067) was similar in groups 1 and 2. The mean coronal obliquity of the femoral tunnel was significantly lower in group 1 than in group 2 (42.5° ± 6.1° vs 49.3° ± 7.2°, respectively; P = .001), but the mean sagittal obliquity was similar between the 2 groups (41.9° ± 6.1° vs 43.3° ± 5.4°, respectively; P = .303). The mean area of the tunnel orifice was significantly greater in group 1 than in group 2 (11.6 ± 1.4 × 9.2 ± 1.6 mm vs 10.3 ± 1.1 × 9.1 ± 1.4 mm, respectively; P = .013).

Conclusion: The modified transtibial technique for SB ACL reconstruction showed good clinical results and anatomic placement of the femoral tunnel, similar with those of the AM portal technique.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1177/0363546514551922DOI Listing
December 2014

Total Knee Arthroplasty Using a Posterior Cruciate Ligament Sacrificing Medial Pivot Knee: Minimum 5-year Follow-up Results.

Knee Surg Relat Res 2014 Sep 29;26(3):135-40. Epub 2014 Aug 29.

Department of Orthopedic Surgery, Arthro-center, Ulsan University Hospital, University of Ulsan College of Medicine, Ulsan, Korea.

Purpose: To evaluate minimum 5-year follow-up clinical and radiological results of total knee arthroplasty (TKA) using a posterior cruciate ligament sacrificing (PS), non-substituting Advance Medial Pivot Knee.

Materials And Methods: One hundred and twenty knees in 80 patients who could be followed up for more than 5 years after TKA using the PS Advance Medial Pivot Knee were evaluated retrospectively. The evaluations included the preoperative and postoperative range of motion (ROM), tibiofemoral angle, Knee Society (KS) knee and function scores, and Western Ontario and McMaster Universities Arthritis Index (WOMAC) score. The Kaplan-Meier method was used for survival analysis.

Results: The ROM increased from a preoperative mean flexion contracture of 7.6° and further flexion of 115.1° to a postoperative mean flexion contracture of 1.5° and further flexion of 120.5°. The tibiofemoral angle was changed from 4.6° varus preoperatively to 5.8° valgus postoperatively. The KS knee and function scores as well as WOMAC score significantly improved after surgery (p<0.05). Complications developed in 4 cases (3.3%): 2 cases of periprosthetic patellar fracture (1.7%) and 2 cases of aseptic loosening (1.7%). The seven-year survival rate was 98.1% in the Kaplan-Meier survival analysis.

Conclusions: The minimum 5-year follow-up results of TKA using the PS Medial Pivot Knee were satisfactory.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.5792/ksrr.2014.26.3.135DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4163570PMC
September 2014

Relationship between prenatal and postnatal exposures to folate and risks of allergic and respiratory diseases in early childhood.

Pediatr Pulmonol 2015 Feb 10;50(2):155-63. Epub 2014 Mar 10.

Department of Pediatrics, Ulsan University Hospital, University of Ulsan Collage of Medicine, Ulsan, Korea.

Background: It is uncertain whether folate is risk or preventive factor for allergic and respiratory diseases.

Objective: To determine the relationship between maternal or offspring folate status and subsequent development of allergic and respiratory diseases in early childhood.

Methods: In total, 917 mother-child pairs from a prospective birth cohort in South Korea were studied. Data regarding the children's allergic and respiratory outcomes were obtained from standardized questionnaires completed by the mothers at postnatal months 6, 12, and 24. Serum folate levels were measured in the mothers at mid- and late-pregnancy, and in their children at 24 months of age. Atopic biomarkers were measured in the cord blood (CB) and at 24 months after birth. Biomarkers and clinical outcomes were analyzed and compared between the mother-child pairs divided into two groups according to median serum folate status at mid- and late-pregnancy.

Results: Serum folate levels during mid-pregnancy were inversely associated with CB eosinophil count (adjusted odds ratio [OR] 0.72, 95% confidence interval [CI], 0.54-0.96) and positively associated with CB interleukin-10 levels (1.47, 1.11-1.94). Maternal folate level above the median value (≥9.5 ng/ml) during mid-pregnancy was associated with a decreased risk for the child of lower respiratory tract infections (LRTIs) at 6 months of age (adjusted OR 0.50, 95% CI 0.28-0.91) and atopic dermatitis (AD) at 24 months (adjusted OR 0.52, 95% CI 0.31-0.88), but not with LRTIs and AD at other ages.

Conclusions: A relatively high maternal serum folate level in mid-pregnancy was associated with a decreased risk of LRTIs and AD in early childhood.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1002/ppul.23025DOI Listing
February 2015

Targeted theranostic nanoparticles: receptor-mediated entry into cells, pH-induced signal generation and cytosolic delivery.

Small 2014 Mar 18;10(5):901-6. Epub 2013 Sep 18.

Graduate School and Department of Analytical Science and Technology, Chungnam National University, Daejeon, 305-764, Republic of Korea.

Virus-like theranostic nanoparticles: virus-like poly(amino acid) nanoparticles are synthesized that can be internalized via receptor-mediated endocytosis, resulting in encapsulated pH-activatable fluorescence probes that can be turned on in acidic environments but otherwise remain undetectable. The encapsulated anticancer drugs are also released into cytosol by endosome disruption.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1002/smll.201302136DOI Listing
March 2014

The combination of real-time PCR and HPLC for the identification of non-tuberculous mycobacteria.

Ann Lab Med 2013 Sep 8;33(5):349-52. Epub 2013 Aug 8.

Department of Laboratory Medicine, Ulsan University Hospital, University of Ulsan College of Medicine, Ulsan, Korea.

We used HPLC and AdvanSure real-time PCR (LG Life Sciences, Korea) to retrospectively analyze non-tuberculous mycobacteria (NTM) in 133 clinical specimens. The specimens were culture-positive for NTM and the HPLC method identified 130 strains of mycobacteria from the cultures (97.7%) at the species level. Among the isolates, 48 Mycobacterium. kansasii (36.1%), 39 M. intracellulare (29.3%), 17 M. avium (12.8%), 16 M. abscessus (12.0%), 6 M. fortuitum (4.5%), 2 M. szulgai (1.5%), 2 M. gordonae (1.5%), and 3 unclassified NTM strains (2.3%) were identified. The real-time PCR assay identified 60 NTM-positive specimens (45.1%), 65 negative specimens (48.9%), and 8 M. tuberculosis (TB)-positive specimens (6.0%). The real-time PCR assay is advantageous because of its rapid identification of NTM. However, in our study, the real-time PCR assay showed relatively low sensitivity (45.1%) when using direct specimens including sputum and bronchoalveolar lavage (BAL) fluid. HPLC is useful as it discriminates NTM at the species level, although it is time-consuming and requires specific equipment and technical expertise. A combination of both methods will be helpful for the rapid and accurate identification of mycobacteria in clinical laboratories.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3343/alm.2013.33.5.349DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3756239PMC
September 2013

Mycobacterium parakoreense sp. nov., a slowly growing non-chromogenic species related to Mycobacterium koreense, isolated from a human clinical specimen.

Int J Syst Evol Microbiol 2013 Jun 16;63(Pt 6):2301-2308. Epub 2012 Nov 16.

Department of Microbiology and Immunology, Biomedical Sciences, Liver Research Institute, Institute of Endemic Diseases, Seoul National University Medical Research Center (SNUMRC), Seoul National University College of Medicine, Seoul 110-799, Republic of Korea.

A previously undescribed, slowly growing, non-chromogenic Mycobacterium strain (299(T)) was isolated from the sputum sample of a patient with a symptomatic pulmonary infection. Phenotypically, strain 299(T) was generally similar to Mycobacterium koreense DSM 45576(T) and Mycobacterium triviale ATCC 23292(T). The 16S rRNA gene sequence of strain 299(T) was similar to that of M. koreense DSM 45576(T) (GenBank accession no. AY734996, 99.5% similarity); however, it differed substantially from that of M. triviale ATCC 23292(T) (X88924, 98.2%). Phylogenetic analysis based on 16S rRNA gene sequences showed that strain 299(T) clustered together with M. koreense DSM 45576(T) and M. triviale ATCC 23292(T), supported by high bootstrapping values (99%). Unique mycolic acid profiles and phylogenetic analysis based on two different chronometer molecules, the hsp65 and rpoB genes, strongly supported the taxonomic status of this strain as representing a distinct species. These data support the conclusion that strain 299(T) represents a novel mycobacterial species, for which the name Mycobacterium parakoreense sp. nov. is proposed. The type strain is 299(T) (=DSM 45575(T)=KCTC 19818(T)).
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1099/ijs.0.045070-0DOI Listing
June 2013

Lung infection caused by Mycobacterium riyadhense confused with Mycobacterium tuberculosis: the first case in Korea.

Ann Lab Med 2012 Jul 20;32(4):298-303. Epub 2012 Jun 20.

Department of Laboratory Medicine, Ulsan University Hospital, University of Ulsan College of Medicine, Korea.

A slowly growing, non-chromogenic mycobacterial strain was isolated from sputum and bronchial lavage fluid samples of a patient presenting with productive cough, blood-tinged sputum, low-grade fever, and weakness. A positive acid-fast bacilli sputum smear result prompted the initiation of an anti-tuberculosis regimen. Multiplex real-time PCR showed a negative result for Mycobacterium tuberculosis complex and a positive result for nontuberculous mycobacteria. The DNA chip test confirmed this organism as a member of the genus Mycobacterium, but could not specify the species. Interestingly, the mycolic acid patterns obtained by HPLC nearly overlapped with those of M. simulans. The sequences of the Mycobacterium 16S rRNA gene and 16S-23S internal transcribed spacer region were unique and were found to have 100% similarity with those of M. riyadhense. After a review of the literature, we report this case as the first Korean case of M. riyadhense lung infection.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3343/alm.2012.32.4.298DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3384813PMC
July 2012

A novel homozygous missense ADAMTS13 mutation Y658C in a patient with recurrent thrombotic thrombocytopenic purpura.

Ann Clin Lab Sci 2011 ;41(3):273-6

Department of Laboratory Medicine, Ulsan University Hospital, University of Ulsan College of Medicine, Korea.

Thrombotic thrombocytopenic purpura (TTP) is a devastating systemic disorder that is characterized by microangiopathic hemolytic anemia, thrombocytopenia, neurological dysfunction, and renal failure. In the hereditary form of TTP, severe deficiency of ADAMTS13, a plasma metalloprotease that cleaves von Willebrand factor, is associated with the development of this disorder. A 34-year-old woman was diagnosed with TTP due to severely reduced ADAMTS13 activity; clinical manifestations resolved only by repeated total plasma exchanges or transfusion. Homozygous and heterozygous Y658C (c.1973A>G) alleles were detected in the patient and her child with severe and mild ADAMTS13 deficiencies, respectively. Herein, we report a novel missense mutation Y658C (c.1973A>G) on exon 17 of ADAMTS13 and discuss its clinical implications.
View Article and Find Full Text PDF

Download full-text PDF

Source
February 2012

Comparison of an automated repetitive sequence-based PCR microbial typing system with IS6110-restriction fragment length polymorphism for epidemiologic investigation of clinical Mycobacterium tuberculosis isolates in Korea.

Korean J Lab Med 2011 Oct 3;31(4):282-4. Epub 2011 Oct 3.

Department of Laboratory Medicine, School of Medicine, Pusan National University, Yangsan, Korea.

Tuberculosis remains a severe public health problem worldwide. Presently, genotyping is used for conducting epidemiologic and clinical studies on tuberculosis cases. We evaluated the efficacy of the repetitive sequence-based PCR (rep-PCR)-based DiversiLab™ system (bioMérieux, France) over the IS6110-restriction fragment length polymorphism analysis for detecting Mycobacterium tuberculosis. In all, 89 clinical M. tuberculosis isolates collected nationwide from Korea were used. The DiversiLab system allocated the 89 isolates to 8 groups with 1 unique isolate when a similarity level of 95% was applied. Seventy-six isolates of the Beijing family and 13 isolates of non-Beijing family strains were irregularly distributed regardless of rep-PCR groups. The DiversiLab system generated a rapid, sensitive, and standardized result. It can be used to conduct molecular epidemiologic studies to identify clinical M. tuberculosis isolates in Korea.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3343/kjlm.2011.31.4.282DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3190008PMC
October 2011

The Use of High Performance Liquid Chromatography to Speciate and Characterize the Epidemiology of Mycobacteria.

Lab Med 2011 Oct;42(10):612-617

Objective: We evaluated high-performance liquid chromatography (HPLC) for species identification of mycobacteria from various clinical specimens in an urban hospital in South Korea between January 2005 and December 2009.

Methods: In the study period 24,774 cultures were completed, yielding the 3215 clinical isolates cultivated for mycobacteria and positive cultures that had mycolic acid investigated by HPLC. For species identification, we compared HPLC patterns of clinical isolates with 33 standard species.

Results: There were 3 different HPLC groups with single, double, and triple-cluster patterns representing 9, 20, and 4 mycobacterial species, respectively. Species identification rates of HPLC for and nontuberculous mycobacteria (NTM) were found to be 100% and 95.6%, respectively. Among mycobacterial isolates, 12.1% were NTM-positive. There were 20 different NTM species with frequencies of 0.3%~15.5%.

Conclusion: The HPLC method was highly sensitive identifying NTM isolated from clinical specimens.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1309/LMDDEHPSYE6ZDM3CDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3892985PMC
October 2011

Mycobacterium koreense sp. nov., a slowly growing non-chromogenic species closely related to Mycobacterium triviale.

Int J Syst Evol Microbiol 2012 Jun 22;62(Pt 6):1289-1295. Epub 2011 Jul 22.

Department of Microbiology and Immunology, Cancer Research Institute and Liver Research Institute, College of Medicine, Seoul National University, Seoul 110-799, Republic of Korea.

A novel slow-growing, non-chromogenic mycobacterium (strain 01-305(T)) was isolated from a patient with pulmonary dysfunction. Growth characteristics, acid-fastness and the results of 16S rRNA gene sequencing supported the placement of this strain within the genus Mycobacterium. Phenotypically, strain 01-305(T) was generally similar to Mycobacterium triviale ATCC 23292(T), but some unique biochemical characteristics were observed. The 16S rRNA gene sequence of strain 01-305(T) was similar to those of M. triviale ATCC 23290 (GenBank accession no. AY734996, 99.9 % similarity) and M. triviale ATCC 23291 (AY734995, 99.9 %); however, it differed substantially from that of M. triviale ATCC 23292(T) (X88924, 98.2 %). Phylogenetic analysis based on 16S rRNA gene sequences placed strain 01-305(T) in the slow-growing Mycobacterium group close to M. triviale ATCC 23290 and M. triviale ATCC 23291, but not M. triviale ATCC 23292(T). Unique mycolic acid profiles and phylogenetic analysis based on two different chronometer molecules, and the hsp65 and rpoB genes, strongly supported the taxonomic status of this strain as representing a distinct species. These data support the conclusion that strain 01-305(T) represents a novel mycobacterial species, for which the name Mycobacterium koreense sp. nov. is proposed. The type strain is 01-305(T) ( = DSM 45576(T) = KCTC 19819(T)).
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1099/ijs.0.033274-0DOI Listing
June 2012

Antimicrobial activity of plant extracts against Salmonella Typhimurium, Escherichia coli O157:H7, and Listeria monocytogenes on fresh lettuce.

J Food Sci 2011 Jan-Feb;76(1):M41-6. Epub 2010 Dec 1.

Dept. of Food and Animal Biotechnology, Seoul National Univ., San 56-1, Sillim-dong, Gwanak-gu, Seoul 151-742, Korea.

Plant extracts have been found to be effective in reducing microorganisms. This study evaluated antimicrobial activity of 12 plant extracts against Salmonella Typhimurium, Escherichia coli O157:H7, and Listeria monocytogenes by using a disk diffusion assay, and Syzygium aromaticum (clove) showed the highest inhibitory effect. To investigate the efficacy of clove extract that inactivates pathogens on lettuce, inoculated lettuce with S. Typhimurium, E. coli O157:H7, and L. monocytogenes was treated with diluted clove extracts or distilled water for 0, 1, 3, 5, and 10 min. Clove extract treatment significantly reduced populations of the 3 tested pathogens from the surface of lettuce. Practical Application: This result indicated that clove extract is a useful antimicrobial agent to reduce the microbial level of foodborne pathogens on fresh lettuce. It also might be a natural antimicrobial for reducing or replacing chemical sanitizers in food preservation.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1111/j.1750-3841.2010.01926.xDOI Listing
September 2011

Improving the blood collection process using the active-phlebotomist phlebotomy system.

Clin Lab 2011 ;57(1-2):21-7

Department of Laboratory Medicine and Genetics, Soonchunhyang University Bucheon Hospital, Gyeonggi, Korea.

Background: Because the number of patients requiring phlebotomy varies significantly at different times throughout the day, it is difficult to control wait times during peak times. We tried to solve this problem by changing from the conventional fixed-phlebotomist phlebotomy system (CFPPS), in which the phlebotomist waits for patients at a fixed location to the active-phlebotomist phlebotomy system (APPS), in which a phlebotomist goes to patients actively. We compared the productivity of these two systems.

Methods: After changing the system at our hospital, we measured the waiting time before seeing phlebotomy staff and compared it to a comparable hospital that uses CFPPS. We reviewed the phlebotomy count recorded in the laboratory information system before and after the system change.

Results: After the system change, the average waiting time for phlebotomy was 2.34 min (median 1 min) and the waiting time was less than 5 min in all time slots, except 7:00 to 7:30 a.m. The new system significantly decreased the waiting time. In addition, the maximum number of patients seen by a phlebotomist during the peak time was higher in the APPS.

Conclusion: The APPS enhanced the productivity of the phlebotomist and reduced waiting time with limited human resources in a Korean hospital.
View Article and Find Full Text PDF

Download full-text PDF

Source
April 2011

MONW phenotype is associated with advanced colorectal adenoma in Korean men.

Obesity (Silver Spring) 2012 Sep 3;20(9):1876-81. Epub 2011 Mar 3.

Department of Family Medicine, Ulsan University Hospital, University of Ulsan College of Medicine, Ulsan, South Korea.

The aim of this study was to investigate whether there was a relationship between colorectal adenoma and metabolically obese but normal weight (MONW) among Korean men and women. The MONW phenotype is defined as a BMI <25, but fulfilling the metabolic syndrome (MS) criteria with a modified waist circumference (≥90 cm for men and ≥85 cm for women) appropriate for Korean. A total of 3,430 subjects (2,263 men and 1,167 women; 23-75 years old) were included in the study. Colorectal adenomas were diagnosed in 775 men and 199 women. The rate of advanced adenomas in males was 24.3% and in females 21.1%. A significant association between MONW and advanced colorectal adenoma was found in men (age-adjusted odds ratio (OR) = 1.92, 95% confidence interval (CI): 1.06-3.47) but not in women (age-adjusted OR = 1.80, 95% CI: 0.50-6.45). The findings suggest that men with MONW may have an increased risk of developing advanced colorectal adenoma whereas this does not seem true for females.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1038/oby.2011.34DOI Listing
September 2012

Transcription factor Sp1 regulates basal transcription of the human DRG2 gene.

Biochim Biophys Acta 2011 Mar 2;1809(3):184-90. Epub 2011 Feb 2.

Department of Biological Sciences, University of Ulsan, Ulsan 680-749, Korea.

Developmentally regulated GTP-binding protein 2 (DRG2) is an evolutionarily conserved GTP-binding protein. DRG2 mRNA expression has been confirmed in many animal and human tissues. DRG2 is thought to play an essential role in the control of cell growth and differentiation. However, transcriptional regulation of DRG2 is largely unknown. To investigate the mechanisms controlling DRG2 expression, we cloned 1509bp of the 5'-flanking sequence of this gene. Deletion analysis showed that the region between -113 and -70 is essential for the basal level expression of the DRG2 gene in K562 human erythroleukemic cells. Mutation of a putative stimulating protein 1 (Sp1) regulatory site located at position -108 resulted in a significant decline in DRG2 promoter activity. Electrophoretic mobility shift assay and chromatin immunoprecipitation analysis revealed that Sp1 binds to this site. Knockdown of Sp1 expression using siRNA inhibited the promoter activation as well as the endogenous DRG2 transcriptional level. Taken together, these results demonstrate that basal expression level of DRG2 is regulated by the Sp1 transcription factor.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.bbagrm.2011.01.004DOI Listing
March 2011

Molecular identification of the novel Gγ-β hybrid hemoglobin: Hb Gγ-β Ulsan (Gγ through 13; β from 19).

Blood Cells Mol Dis 2010 Dec 29;45(4):276-9. Epub 2010 Oct 29.

Department of Laboratory Medicine, Seoul National University Hospital, 110-744, Seoul, Republic of Korea.

Gene fusion is a very rare mechanism that produces hemoglobin variants. Less than ten types of β-like hybrid globins have been reported to date. Herein we identified the first hybrid hemoglobin between Gγ- and β-globins in a five-year-old Korean male who had thalassemia minor feature and triplication of the HBA2 gene (αα/αααα). The novel globin originated from a 27,707-base pair deletion spanning from the HBG2 to HBB gene (NG_000007.3:g.42947_70653del). Its protein sequence included 13 N-terminal amino acids from Gγ-globin, five common amino acids from Gγ- and β-globins, and 128 amino acids from β-globin (Gγ through 13; β from 19). Molecular genetic analyses characterized the hybrid DNA and RNA. Mass spectrometry and de novo protein sequencing successfully identified the fusion peptide in the hybrid hemoglobin. We named this novel hybrid Hb Gγ-β Ulsan. The novel hemoglobin constituted 37.0% of the total hemoglobin and showed reduced oxygen affinity.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.bcmd.2010.10.001DOI Listing
December 2010