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1.  Evaluation of Postoperative Range of Motion and Functional Outcomes after Cruciate-Retaining and Posterior-Stabilized High-Flexion Total Knee Arthroplasty 
Yonsei Medical Journal  2012;53(4):794-800.
The purpose of this study was to compare postoperative range of motion and functional outcomes among patients who received high-flexion total knee arthroplasty using cruciate-retaining (CR-Flex) and posterior-stabilized (PS-Flex) type prostheses.
Materials and Methods
Among 127 patients (186 knees) who underwent high-flexion total knee arthroplasty between 2005 and 2007, 92 knees were placed in the CR-Flex group, and 94 knees were placed in the PS-Flex group. After two years of postoperative follow-up, clinical and radiographic data were reviewed. Postoperative non-weight-bearing range of knee motion, angle of flexion contracture and functional outcomes based on the Western Ontario and McMaster Universities Osteoarthritis (WOMAC) functional sub-scale were assessed and compared between the two groups.
After the 2-year postoperative period, the mean range of motion was 131° in the CR-Flex group and 133° in the PS-Flex group. There were no significant differences in postoperative range of motion between the two groups. Only age at operation and preoperative range of motion were significantly associated with postoperative range of motion after high-flexion total knee arthroplasty. Postoperative functional outcomes based on the WOMAC functional sub-scale were slightly better in the CR-Flex group (9.2±9.1 points) than in the PS-Flex group (11.9±9.6 points); however, this difference was not statistically significant (p=non-significant).
The retention or substitution of the posterior cruciate ligament does not affect postoperative range of motion (ROM) or functional outcomes, according to 2 years of postoperative follow-up of high-flexion total knee arthroplasty.
PMCID: PMC3381472  PMID: 22665348
Total knee arthroplasty; range of motion; functional outcomes; cruciate-retaining; posterior-stabilized; high-flexion
2.  Long-Term Follow-Up Results of a Second-Generation Cementless Femoral Prosthesis with a Collar and Straight Distal Fixation Channels 
Yonsei Medical Journal  2011;53(1):186-192.
We evaluated the results of more than 10 years of follow-up of total hip arthroplasty using a second-generation cementless femoral prosthesis with a collar and straight distal fixation channels.
Materials and Methods
One hundred five patients (129 hips) who underwent surgery between 1991 and 1996 for primary total hip arthroplasty using cementless straight distal fluted femoral stems were followed for more than 10 years. Ninety-four hips in 80 patients were available for clinical and radiologic analysis. The mean age at the time of surgery was 47 years, and the mean duration of follow-up was 14.3 years.
The mean Harris hip scores had improved from 58 points to 88 points at the time of the 10-year follow-up. Activity-related thigh pain was reported in nine hips (10%). At the last follow-up, 93 stems (99%) were biologically stable and one stem (1%) was revised because of loosening. No hip had distal diaphyseal osteolysis. Proximal femoral stress-shielding was reported in 86 hips (91%). We found no significant relationship between collar-calcar contact and thigh pain, stem fixation status, or stress-shielding. The cumulative survival of the femoral stem was 99% (95% confidence interval, 98-100%) after 10 years.
The long-term results of total hip arthroplasty using a second-generation cementless femoral prosthesis with a collar and straight distal fixation channels were satisfactory; however, the high rate of proximal stress-shielding and the minimal effect of the collar indicate the need for some changes in the stem design.
PMCID: PMC3250326  PMID: 22187251
Total hip arthroplasty; second-generation; cementless; collar; straight distal fixation channel
3.  Isoniazid Could Be Used for Antibiotic-loaded Bone Cement for Musculoskeletal Tuberculosis: An In Vitro Study 
Antibiotic-loaded bone cement (ALBC) has been used in serious cases of musculoskeletal tuberculosis, but the type and amount of antibiotic that should be used in ALBC have not been determined.
We therefore determined the (1) elution characteristics and (2) antimycobacterial activity of isoniazid- and rifampicin-loaded bone cement.
A total of 240 elution samples of each of three discs from 40 g bone cement mixed with one of eight dosages: 1 g, 2 g, and 4 g isoniazid, 1 g, 2 g, and 4 g rifampicin, and a combination of 1 + 1 g or 2 + 2 g of isoniazid and rifampicin. The polymerization of rifampicin-loaded bone cement was delayed to mean 122.5 ± 31.1 minutes. We measured the quantity of isoniazid and rifampicin and the antimycobacterial activity on Days 1, 3, 7, 14, and 30.
Isoniazid eluted in almost all the samples while rifampicin was detected only on Day 1 with 2 g (0.7 ± 0.4 ug/mL/day), and until Day 14 with 4 g (0.1 ± 0.0u g/mL/day). Most of the samples containing isoniazid showed antimycobacterial activity while the samples containing rifampicin showed antimycobacterial activity only on Day 1 with 1 g (0.52 ± 0.18 ug/mL), until Day 14 with 2 g (0.03 ± 0.00 ug/mL), and until Day 30 with 4 g (1.84 ± 1.90 ug/mL).
Rifampicin was unsuitable for ALBC because of its delayed polymerization. Isoniazid eluted and showed antimycobacterial activity for 30 days.
Clinical Relevance
The data suggest isoniazid could be considered for use in ALBC for musculoskeletal tuberculosis if used with systemic treatment. For preventing resistance and systemic toxicity, a combination with a second-line drug and an in vivo study would be needed.
PMCID: PMC3676586  PMID: 23504536
4.  Effects of resveratrol on the insulin signaling pathway of obese mice 
Journal of Veterinary Science  2014;15(2):179-185.
The present study was conducted to investigate the effects of resveratrol on the insulin signaling pathway in the liver of obese mice. To accomplish this, we administered resveratrol to high fat diet-induced obese mice and examined the levels of protein phosphorylation in the liver using an antibody array. The phosphorylation levels of 10 proteins were decreased in the high fat diet and resveratrol (HFR) fed group relative to the levels in the high fat diet (HF) fed group. In contrast, the phosphorylation levels of more than 20 proteins were increased in the HFR group when compared with the levels of proteins in the HF group. Specifically, the phosphorylation levels of Akt (The308, Tyr326, Ser473) were restored to normal by resveratrol when compared with the levels in the HF group. In addition, the phosphorylation levels of IRS-1 (Ser636/Ser639), PI-3K p85-subunit α/γ(Tyr467/Tyr199), PDK1 (Ser241), GSK-3α (S21) and GSK-3 (Ser9), which are involved in the insulin signaling pathway, were decreased in the HF group, whereas the levels were restored to normal in the HFR group. Overall, the results show that resveratrol restores the phosphorylation levels of proteins involved in the insulin signaling pathway, which were decreased by a high fat diet.
PMCID: PMC4087218  PMID: 24675832
Akt phosphorylation; antibody array; insulin signaling pathway; obese mice; resveratrol
5.  Avatar DNA Nanohybrid System in Chip-on-a-Phone 
Scientific Reports  2014;4:4879.
Long admired for informational role and recognition function in multidisciplinary science, DNA nanohybrids have been emerging as ideal materials for molecular nanotechnology and genetic information code. Here, we designed an optical machine-readable DNA icon on microarray, Avatar DNA, for automatic identification and data capture such as Quick Response and ColorZip codes. Avatar icon is made of telepathic DNA-DNA hybrids inscribed on chips, which can be identified by camera of smartphone with application software. Information encoded in base-sequences can be accessed by connecting an off-line icon to an on-line web-server network to provide message, index, or URL from database library. Avatar DNA is then converged with nano-bio-info-cogno science: each building block stands for inorganic nanosheets, nucleotides, digits, and pixels. This convergence could address item-level identification that strengthens supply-chain security for drug counterfeits. It can, therefore, provide molecular-level vision through mobile network to coordinate and integrate data management channels for visual detection and recording.
PMCID: PMC4019957  PMID: 24824876
6.  Hemodynamic responses in rat brain during transcranial direct current stimulation: a functional near-infrared spectroscopy study 
Biomedical Optics Express  2014;5(6):1812-1821.
In the present study, we monitored hemodynamic responses in rat brains during transcranial direct current stimulation (tDCS) using functional near-infrared spectroscopy (fNIRS). Seven rats received transcranial anodal stimulation with 200 μA direct current (DC) on their right barrel cortex for 10 min. The concentration changes of oxygenated hemoglobin (oxy-Hb) were continuously monitored during stimulation (10 min) and after stimulation (20 min). The trend of hemodynamic response changes was modeled using linear regression, and the relationship between incremental and decremental rates of oxy-Hb was investigated by correlation analysis. Our results showed that the oxy-Hb concentration was almost linearly increased and decreased during and after stimulation, respectively. In addition, a significant negative correlation (p < 0.05) was found between the rate of increase of oxy-Hb during stimulation and the rate of decrease of oxy-Hb after stimulation, indicating that the recovery time after tDCS may not depend on the total amount of hemodynamic changes in the stimulated brain area. Our results also demonstrated considerable individual variability in the rate of change of hemodynamic responses even with the same direct current dose to identical brain regions. This suggests that individual differences in tDCS after-effects may originate from intrinsic differences in the speed of DC stimulation “uptake” rather than differences in the total capacity of DC uptake, and thus the stimulation parameters may need to be customized for each individual in order to maximize tDCS after-effects.
PMCID: PMC4052913  PMID: 24940542
(170.0170) Medical optics and biotechnology; (170.2655) Functional monitoring and imaging; (170.6510) Spectroscopy, tissue diagnostics
7.  Apolipoprotein A-I and HDL Have Anti-Inflammatory Effects on Adipocytes via Cholesterol Transporters: ATP-Binding Cassette (ABC) A-1, ABCG-1 and Scavenger Receptor B-1(SRB-1) 
Circulation research  2013;112(10):1345-1354.
Macrophage accumulation in adipose tissue associates with insulin resistance and increased cardiovascular disease risk. We previously have shown that generation of reactive oxygen species (ROS) and monocyte chemotactic factors after exposure of adipocytes to saturated fatty acids (SFAs) such as palmitate occurs via translocation of NADPH oxidase 4 (NOX4) into lipid rafts (LRs). The anti-inflammatory effects of apolipoprotein A-I (apoA-I) and HDL on macrophages and endothelial cells appears to occur via cholesterol depletion of LRs. However, little is known concerning anti-inflammatory effects of HDL and apoA-I on adipocytes.
To determine whether apoA-I and HDL inhibit inflammation in adipocytes and adipose tissue, and whether this is dependent on LRs.
Methods and Results
In 3T3L-1 adipocytes, apoA-I, HDL and methyl-β-cyclodextrin inhibited chemotactic factor expression. ApoA-I and HDL also disrupted LRs, reduced plasma membrane cholesterol content, inhibited NOX4 translocation into LRs, and reduced palmitate-induced ROS generation and monocyte chemotactic factor expression. Silencing ABCA-1 abrogated the effect of apoA-I, but not HDL, while silencing ABCG-1 or SRB-1 abrogated the effect of HDL but not apoA-I. In vivo, apoA-I transgenic mice fed a high fat, high sucrose, cholesterol-containing diet showed reduced chemotactic factor and pro-inflammatory cytokine expression and reduced macrophage accumulation in adipose tissue.
ApoA-I and HDL have anti-inflammatory effects in adipocytes and adipose tissue similar to their effects in other cell types. These effects are consistent with disruption and removal of cholesterol from LRs, which are regulated by cholesterol transporters such as ABCA-1, ABCG-1 and SRB-1.
PMCID: PMC3767575  PMID: 23501697
Adipocytes; ABC transporters; cholesterol; HDL; Apolipoprotein A-I
8.  Antimicrobial Susceptibility Pattern and Epidemiology of Female Urinary Tract Infections in South Korea, 2010-2011 
Antimicrobial Agents and Chemotherapy  2013;57(11):5384-5393.
This study aimed to (i) investigate the antimicrobial susceptibilities of bacteria that cause urinary tract infections (UTIs) in outpatient and inpatient settings and (ii) evaluate the risk factors for emerging antimicrobial drug resistance in UTIs in South Korea. In total, 3,023 samples without duplication were collected from females between 25 and 65 years of age who had been diagnosed with a urinary tract infection. Multicenter patient data were collected using a Web-based electronic system and then evaluated. The isolation rates of Escherichia coli, Klebsiella pneumoniae, and Enterococcus faecium in the outpatient setting were 78.1, 4.7, and 1.3%, respectively; in the inpatient setting, the isolation rates of these microorganisms were 37.8, 9.9, and 14.8%, respectively. The susceptibilities of E. coli to amikacin, amoxicillin-clavulanic acid, cefotaxime, cefoxitin, ciprofloxacin, piperacillin-tazobactam, and imipenem in the outpatient setting were 99.4, 79.8, 89.4, 92.8, 69.8, 96.9, and 100.0%, respectively; in the inpatient setting, the susceptibilities to these antibiotics were 97.8, 73.9, 73.7, 82.1, 53.6, 93.2, and 100.0%, respectively. The most unique and common risk factor for emerging antimicrobial-resistant E. coli, K. pneumoniae, and E. faecium was previous exposure to antimicrobials. On the basis of these data, the use of fluoroquinolones should be reserved until culture data are available for the treatment of UTIs in South Korea. The present study will serve as a useful reference for Far Eastern Asia.
PMCID: PMC3811252  PMID: 23959315
9.  Enhancement of Platelet Aggregation by Ursolic Acid and Oleanolic Acid 
Biomolecules & Therapeutics  2014;22(3):254-259.
The pentacyclic triterpenoid ursolic acid (UA) and its isomer oleanolic acid (OA) are ubiquitous in food and plant medicine, and thus are easily exposed to the population through natural contact or intentional use. Although they have diverse health benefits, reported cardiovascular protective activity is contentious. In this study, the effect of UA and OA on platelet aggregation was examined on the basis that alteration of platelet activity is a potential process contributing to cardiovascular events. Treatment of UA enhanced platelet aggregation induced by thrombin or ADP, which was concentration-dependent in a range of 5–50 μM. Quite comparable results were obtained with OA, in which OA-treated platelets also exhibited an exaggerated response to either thrombin or ADP. UA treatment potentiated aggregation of whole blood, while OA failed to increase aggregation by thrombin. UA and OA did not affect plasma coagulation assessed by measuring prothrombin time and activated partial thromboplastin time. These results indicate that both UA and OA are capable of making platelets susceptible to aggregatory stimuli, and platelets rather than clotting factors are the primary target of them in proaggregatory activity. These compounds need to be used with caution, especially in the population with a predisposition to cardiovascular events.
PMCID: PMC4060080  PMID: 25009707
Ursolic acid; Oleanolic acid; Platelet aggregation
10.  A reusable evanescent wave immunosensor for highly sensitive detection of bisphenol A in water samples 
Scientific Reports  2014;4:4572.
This paper proposed a compact and portable planar waveguide evanescent wave immunosensor (EWI) for highly sensitive detection of BPA. The incident light is coupled into the planar waveguide chip via a beveled angle through undergoing total internal reflection, where the evanescent wave field forms and excites the binding fluorophore-tagged antibodies on the chip surface. Typical calibration curves obtained for BPA has detection limits of 0.03 μg/L. Linear response for BPA ranged from 0.124 μg/L–9.60 μg/L with 50% inhibition concentration for BPA of 1.09 ± 0.25 μg/L. The regeneration of the planar optical waveguide chip allows the performance of more than 300 assay cycles within an analysis time of about 20 min for each assay cycle. By application of effective pretreatment procedure, the recoveries of BPA in real water samples gave values from 88.3% ± 8.5% to 103.7% ± 3.5%, confirming its application potential in the measurement of BPA in reality.
PMCID: PMC3975238  PMID: 24699239
11.  Family Economic Empowerment and Mental Health Among AIDS-Affected Children Living in AIDS-Impacted Communities: Evidence from a Randomized Evaluation in Southwestern Uganda 
We examine whether an innovative family economic empowerment intervention addresses mental health functioning of AIDS-affected children in communities heavily impacted by HIV/AIDS in Uganda.
A cluster randomized controlled trial (RCT) consisting of two study arms: a treatment condition (n=179) and a control condition (n=118) was used to examine the impact of the family economic empowerment intervention on children’s levels of hopelessness and depression. The intervention comprised of matched children savings accounts, financial management workshops, and mentorship. Data were collected at baseline and 12 months post-intervention.
Using multivariate analysis with several socio-economic controls, we find that children in the treatment condition (receiving the intervention) report significant improvement in their mental health functioning. Specifically, the intervention reduces hopelessness and depression levels. On the other hand, children in the control condition (not receiving the intervention) report no changes on both measures.
The findings indicate that children with poor mental health functioning living in communities affected by HIV/AIDS may benefit from innovative family economic empowerment interventions. As measures of mental health functioning, both hopelessness and depression have long-term negative psychosocial and developmental impacts on children. These findings have implications for public health programs intended for long-term care and support of children living in resource poor, AIDS-impacted communities.
PMCID: PMC3578660  PMID: 23410851
12.  Periarticular Injection with Corticosteroid Has an Additional Pain Management Effect in Total Knee Arthroplasty 
Yonsei Medical Journal  2014;55(2):493-498.
Although the analgesic effects of corticosteroids have been well documented, little information is available on periarticular injection (PI) containing corticosteroids for early postoperative pain management after total knee arthroplasty (TKA). We performed a prospective double-blind randomized trial to evaluate the efficacy and safety of an intraoperative corticosteroid PI in patients undergoing TKA.
Materials and Methods
Seventy-six consecutive female patients undergoing bilateral staged TKA were randomized to receive steroid or non-steroid PI, with 3 months separating the procedures. The steroid group received PI with a mixture containing triamcinolone acetonide (40 mg). The non-steroid group received the same injection mixture without corticosteroid. During the postoperative period, nighttime pain, functional recovery [straight leg raising (SLR) ability and maximal flexion], patient satisfaction, and complications were recorded. Short-term postoperative clinical scores and patient satisfaction were evaluated at 6 months.
The pain level was significantly lower in the PI steroid than the non-steroid group on the night of the operation (VAS, 1.2 vs. 2.3; p=0.021). Rebound pain was observed in both groups at POD1 (VAS, 3.2 vs. 3.8; p=0.248), but pain remained at a low level thereafter. No significant differences were seen in maximal flexion, frequency of acute rescuer, clinical scores, and patient satisfaction. The steroid group was able to perform SLR earlier than the non-steroid group (p=0.013). The incidence of complications was similar between the groups.
PI containing a corticosteroid provided an additional pain-relieving effect on the night of the operation. In addition, corticosteroid PI did not increase the perioperative complications of TKA.
PMCID: PMC3936618  PMID: 24532523
Corticosteroid; periarticular injection; pain; total knee arthroplasty
13.  Seoritae Extract Reduces Prostate Weight and Suppresses Prostate Cell Proliferation in a Rat Model of Benign Prostate Hyperplasia 
Seoritae is a type of black soybean that is known to have health-promoting effects due to its high isoflavone and anthocyanin contents. We evaluated whether Seoritae extract (SE) had beneficial effects on the reduction of prostate weight in a rat model of benign prostatic hyperplasia (BPH). BPH was induced by intramuscular injections of testosterone enanthate once a week for 5 weeks in Sprague-Dawley rats, and rats were treated with or without daily oral doses of SE during BPH induction. After 5 weeks, the oxidative stress (superoxide dismutase and 8-hydroxy-2-deoxyguanosine), apoptosis (caspase-3), and activity of 5-alpha reductase were evaluated in the serum and prostate. The SE treatment group showed a significant decrease in prostate weight, oxidative stress, apoptosis, and 5-alpha reductase activity compared to the nontreated BPH group. These results show that SE is effective in decreasing the weight and proliferation of the prostate, and suggest that SE may be an effective treatment for BPH.
PMCID: PMC3950473  PMID: 24701239
14.  Large-scale synthesis of highly emissive and photostable CuInS2/ZnS nanocrystals through hybrid flow reactor 
We report a high-yield, low-cost synthesis route to colloidal CuInS2/ZnS (CIS/ZnS) nanocrystals (NCs) with Cu vacancies in the crystal lattice. Yellow-emitting CIS/ZnS core/shell NCs of high luminescence were facilely synthesized via a stepwise, consecutive hybrid flow reactor approach. It is based on serial combination of a batch-type mixer and a flow-type furnace. In this reactor, the flow rate of the solutions was typically 1 mL/min, 100 times larger than that of conventional microfluidic reactors. This method can produce gram quantities of material with a chemical yield in excess of 90% with minimal solvent waste. This is a noninjection-based approach in 1-dodecanethiol (DDT) with excellent synthetic reproducibility and large-scale capability. The optical features and structure of the obtained CIS/ZnS NCs have been characterized by UV–vis and fluorescence spectroscopies, X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), energy-dispersive X-ray spectroscopy (EDX) and high-resolution transmission electron microscopy (HRTEM). The resulting CIS/ZnS NCs in chloroform exhibit quantum yield (QY) of 61.4% with photoemission peaking at 561 nm and full width at half maximum (FWHM) of 92 nm. The as-synthesized CIS/ZnS NCs were proven to have excellent photostability. The synthesized CIS/ZnS NCs can be a promising fluorescent probe for biological imaging and color converting material for light-emitting diode due to Cd-free constituents.
PMCID: PMC3996094  PMID: 24533662
CuInS2/ZnS nanocrystals; Hybrid flow reactor; Large-scale synthesis; Photostability
15.  Bioreducible polymers as a determining factor for polyplex decomplexation rate and transfection 
Biomacromolecules  2013;14(2):548-556.
Polyplex formation (complexation) and gene release from the polyplexes (decomplexation) are major events in polymeric gene delivery, however the effect of the decomplexation rate on transfection has been rarely investigated. This study employed mixed polymers of poly(L-lysine) (PLL: MW ~7.4 kDa) and reducible PLL (RPLL) (MW ~6.7 kDa) to design decomplexation rate-controllable PLL100-xRPLLx/pDNA complexes (PRLx polyplexes). The transfection efficiency of a model gene (luciferase) in MCF7 and HEK293 cell lines increased with increasing x (RPLL content) in the PRLx polyplexes until peaking at x=2.5 and x=10, respectively, after which point transfection efficiency declined rapidly. In MCF7 cells, PRL2.5 polyplex produced 3- or 223-fold higher gene expression than PLL or RPLL polyplexes, respectively. Similarly, the transfection efficiency of PRL10 polyplex-transfected HEK293 cells was 3.8- or 67-fold higher than that of PLL or RPLL polyplexes, respectively. The transfection results were not apparently related to the particle size, surface charge, complexation/compactness, cellular uptake, or cytotoxicity of the tested polyplexes. However, the decomplexation rate varied by RPLL content in the polyplexes, which in turn influenced the gene transfection. The nuclear localization of pDNA delivered by PRLx polyplexes showed a similar trend to their transfection efficiencies. This study suggests that an optimum decomplexation rate may result in high nuclear localization of pDNA and transfection. Understanding in decomplexation and intracellular localization of pDNA may help develop more effective polyplexes.
PMCID: PMC3570707  PMID: 23259985
Decomplexation; Nuclear localization; Poly(L-lysine); Polymeric gene carrier; Reducible polymer
16.  Formin homology 1 (OsFH1) regulates submergence-dependent root hair development in rice plants 
Plant Signaling & Behavior  2013;8(8):e24970.
By using a forward genetic approach, a formin homology 1 gene (OsFH1) was identified as a critical regulator of rice root hair development. The phenotypic effect of OsFH1 on root hair development was verified by using three independent mutants, one point mutation and two T-DNA insertions. The study showed that OsFH1 is required for the elongation of root-hairs. However, Osfh1 exhibited growth defect of root hairs only when roots were grown submerged in solution. To understand how OsFH1 impinges on plant responses to root submergence, the growth responses of Osfh1 root hairs to anoxia, carbohydrate supplementation and exogenous hormones (auxin and ethylene) and nutrients (Fe and Pi) were examined. However, none of these treatments rescued the growth defects of Osfhl1 root hairs. This study demonstrates that OsFH1 could be involved in preventing submergence-induced inhibition of root hair growth.
PMCID: PMC3999081  PMID: 23733059
root hair; development; formin homology 1 (OsFH1); rice; submergence
17.  Development of an Enzyme-linked Immunosorbent Assay Using Vitellin for Vitellogenin Measurement in the Pale Chub, Zacco platypus 
Fish vitellogenin (VTG) is produced in the female liver during oogenesis through the estradiol cycle and produced in the male liver by endocrine disrupting chemicals (EDCs) such as alkylphenols. In this study, we propose that the VTG concentration in the pale chub could be detected using monoclonal antibodies and polyclonal antibodies against vitellin (Vn) in a VTG enzyme-linked immunosorbent assay (ELISA) system.
Monoclonal antibodies and polyclonal antibodies were produced using the Vn extracted from the matured ovum of the ovary. The VTG was extracted from the plasma of the male pale chub. The Vn and VTG were confirmed by measuring the molecular weight of their proteins using sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and the specificity of the antibodies was checked through western blotting methods. The assay system was validated with respect to optimal assay concentrations, specificity, recovery, and intra- and inter-assay variations.
The Vn consisted of two protein bands with apparent molecular weights of 64 and 37 kDa. The SDS-PAGE indicated protein weights of 146 and 77 kDa in the VTG. The assay range was 15.6 ng/mL to 2,000 ng/mL, and the value of the intra- and inter-assay variations were within 10.0% and 14.7%, respectively. The recovery rate was 99.5±5.5%.
A sandwich ELISA was developed that could be used to qualify the VTG of pale chub in screening for EDCs. Pale chub is an ideal species for observing estrogen activity in the environment because of its extensive habitat and extensive food chain. The ELISA developed here would be more favorable than those for other species for determining the effect of long-term food chain accumulation of EDCs in aquatic environments.
PMCID: PMC3909746  PMID: 24498593
Antibody; Endocrine disrupting chemicals; Enzyme-linked immunosorbent assay system; Pale chub; Vitellin; Vitellogenin
18.  Polymeric Nucleic Acid Carriers: Current Issues and Novel Design Approaches 
To deliver nucleic acids including plasmid DNA (pDNA) and short interfering RNA (siRNA), polymeric gene carriers equipped with various functionalities have been extensively investigated. The functionalities of these polymeric vectors have been designed to overcome various extracellular and intracellular hurdles that nucleic acids and their carriers encounter during their journey from injection site to intracellular target site. This review briefly introduces known extracellular and intracellular issues of nucleic acid delivery and their solution strategies. We examine significant yet overlooked factors affecting nucleic acid delivery (e.g., microenvironmental pH, polymer/siRNA complexation, and pharmaceutical formulation) and highlight our reported approaches to solve these problems.
PMCID: PMC3502710  PMID: 22771981
Gene delivery; Non-viral gene delivery; Nucleic acid delivery; plasmid DNA; Polymeric gene delivery; short interfering RNA
19.  QTc Prolongation after Ventricular Septal Defect Repair in Infants 
Korean Circulation Journal  2013;43(12):825-829.
Background and Objectives
Prolonging of the corrected QT interval (QTc) has been reported after cardiac surgery in some studies. However, there have not been many studies on infant open cardiac surgery for ventricular septal defect (VSD) repair. This study was performed to define the changes in QTc and to find related post-surgery factors in this patient group.
Subjects and Methods
From 2008 to 2012, 154 infants underwent VSD repair at the Severance Cardiovascular Hospital. This study includes 105 of these cases. QTc was measured in these patients retrospectively. Demographic data and peri-procedural data, such as Aristotle score, cross-clamp time and bypass time, were analyzed. The exclusion criteria included multiple and small VSDs that underwent direct closure.
Mean post-operative QTc was increased compared to the pre-operative measurements (from 413.6±2.3 to 444.9±2.5, p<0.001). In multiple linear regression, the comprehensive Aristotle score was associated with increasing QTc (p=0.047). The incidence of transient arrhythmia, such as atrial tachycardia, junctional ectopic tachycardia, premature atrial contraction, or premature ventricular contraction, was associated with QTc prolongation (p=0.005). Prolonged QTc was also associated with cross-clamp time (p=0.008) and low weight (p=0.042). Total length of stay at the intensive care unit and intubation time after surgery were not associated with QTc prolongation.
Prolonged QTc could be seen after VSD repair in infants. This phenomenon was associated with peri-procedural factors such as the Aristotle score and cross-clamp time. Patients with QTc prolongation after cardiac surgery had an increased tendency towards arrhythmogenicity in the post-operative period.
PMCID: PMC3875699  PMID: 24385994
Ventricular septal defect; Electrocardiography; Infant
20.  Regulatory role of indeterminate domain 10 (IDD10) in ammonium-dependent gene expression in rice roots 
Plant Signaling & Behavior  2013;8(5):e24139.
One of the strategies that plants utilize to adapt to fluctuating soil nutrient levels is rapid reprogramming of transcriptional regulation via cell signaling mechanisms. Higher plants exposed to ammonium undergo modulation of a broad spectrum of gene expression. However, regulation of the transcriptional mechanisms underlying ammonium-mediated gene expression is poorly understood. We identified a transcriptional regulator, indeterminate domain 10 (IDD10), whose mutants exhibited an ammonium-hypersensitive root growth defect. To elucidate the molecular relationship between IDD10 and ammonium-mediated gene expression, ammonium-responsive genes were examined in mutants and overexpressors of IDD10. Among the key ammonium uptake and assimilation genes, AMT1;2 (ammonium transporter 1;2) and GDH2 (glutamate dehydrogenase 2) significantly depend on IDD10 expression levels for ammonium-mediated induction. Extensive molecular analysis revealed that IDD10 directly binds to the promoter of AMT1;2 and the fifth intron of GDH2 genes via the core sequence TTTGTCC/G. Transcriptome analysis with root tissues identified many ammonium-inducible genes whose expression was increased by IDD10. Half of them contained potential IDD10-binding motifs in their promoters. This study determined that IDD10 is a transcriptional activator involved in nitrogen regulatory circuits that control a broad spectrum of gene expression, which might influence root growth in rice.
PMCID: PMC3906431  PMID: 23470720
indeterminate domain (IDD) gene; transcription factor; rice; ammonium; root growth
21.  Biocompatible, pH-sensitive AB2 Miktoarm Polymer-Based Polymersomes: Preparation, Characterization, and Acidic pH-Activated Nanostructural Transformation 
Journal of materials chemistry  2012;22(36):91968-19178.
Motivated by the limitations of liposomal drug delivery systems, we designed a novel histidine-based AB2-miktoarm polymer (mPEG-b-(polyHis)2) equipped with a phospholipid-mimic structure, low cytotoxicity, and pH-sensitivity. Using “core-first” click chemistry and ring-opening polymerization, mPEG2kDa-b-(polyHis29kDa)2 was successfully synthesized with a narrow molecular weight distribution (1.14). In borate buffer (pH 9), the miktoarm polymer self-assembled to form a nano-sized polymersome with a hydrodynamic radius of 70.2 nm and a very narrow size polydispersity (0.05). At 4.2 µmol/mg polymer, mPEG2kDa-b-(polyHis29kDa)2 strongly buffered against acidification in the endolysosomal pH range and exhibited low cytotoxicity on a 5 d exposure. Below pH 7.4 the polymersome transitioned to cylindrical micelles, spherical micelles, and finally unimers as the pH was decreased. The pH-induced structural transition of mPEG2kDa-b-(polyHis29kDa)2 nanostructures may be caused by the increasing hydrophilic weight fraction of mPEG2kDa-b-(polyHis29kDa)2 and can help to disrupt the endosomal membrane through proton buffering and membrane fusion of mPEG2kDa-b-(polyHis29kDa)2. In addition, a hydrophilic model dye, 5(6)-carboxyfluorescein encapsulated into the aqueous lumen of the polymersome showed a slow, sustained release at pH 7.4 but greatly accelerated release below pH 6.8, indicating a desirable pH sensitivity of the system in the range of endosomal pH. Therefore, this polymersome that is based on a biocompatible histidine-based miktoarm polymer and undergoes acid-induced transformations could serve as a drug delivery vehicle for chemical and biological drugs.
PMCID: PMC3447630  PMID: 23002330
Polymersome; pH sensitivity; Poly(L-histidine); Structural transition; Miktoarm polymer
22.  pH-Sensitive Polymeric Micelle-based pH Probe for Detecting and Imaging Acidic Biological Environments 
Biomacromolecules  2012;13(9):2945-2951.
To overcome the limitations of monomeric pH probes for acidic tumor environments, this study designed a mixed micelle pH probe composed of polyethylene glycol (PEG)-b- poly(L-histidine) (PHis) and PEG-b-poly(L-lactic acid) (PLLA), which is well-known as an effective antitumor drug carrier. Unlike monomeric histidine and PHis derivatives, the mixed micelles can be structurally destabilized by changes in pH, leading to a better pH sensing system in nuclear magnetic resonance (NMR) techniques. The acidic pH-induced transformation of the mixed micelles allowed pH detection and pH mapping of 0.2–0.3 pH unit differences by pH-induced “on/off”-like sensing of NMR and magnetic resonance spectroscopy (MRS). The micellar pH probes sensed pH differences in non-biological phosphate buffer and biological buffers such as cell culture medium and rat whole blood. In addition, the pH-sensing ability of the mixed micelles was not compromised by loaded doxorubicin. In conclusion, PHis-based micelles could have potential as a tool to simultaneously treat and map the pH of solid tumors in vivo.
PMCID: PMC3438342  PMID: 22861824
pH imaging; poly(L-histidine); micelle pH probe; NMR; MRS
23.  Toll-like Receptor 4 Deficiency Decreases Atherosclerosis but Does Not Protect against Inflammation in Obese LDL Receptor-Deficient Mice 
Obesity is associated with insulin resistance, chronic low-grade inflammation and atherosclerosis. Toll-like receptor 4 (TLR4) participates in the cross-talk between inflammation and insulin resistance, being activated by both lipopolysaccharide and saturated fatty acids. This study was undertaken to determine whether TLR4 deficiency has a protective role in inflammation, insulin resistance and atherosclerosis induced by a diabetogenic diet.
Methods and Results
TLR4 and LDL receptor double knockout (Tlr4−/−Ldlr−/−) mice and Ldlr−/− mice were fed either a normal chow or a diabetogenic diet for 24 weeks. Tlr4−/−Ldlr−/− mice fed a diabetogenic diet showed improved plasma cholesterol and triglyceride levels but developed obesity, hyperinsulinemia and glucose intolerance equivalent to obese Ldlr−/− mice. Adipocyte hypertrophy, macrophage accumulation and local inflammation were not attenuated in intra-abdominal adipose tissue in Tlr4−/−Ldlr−/− mice. However, TLR4 deficiency led to markedly decreased atherosclerosis in obese Tlr4−/−Ldlr−/− mice. Compensatory up-regulation of TLR2 expression was observed both in obese TLR4 deficient mice and in palmitate-treated TLR4-silenced 3T3-L1 adipocytes.
TLR4 deficiency decreases atherosclerosis without affecting obesity-induced inflammation and insulin resistance in LDL receptor deficient mice. Alternative pathways may be responsible for adipose tissue macrophage infiltration and insulin resistance that occurs in obesity.
PMCID: PMC3748807  PMID: 22580897
Toll-like receptor 4; insulin resistance; atherosclerosis; inflammation; diabetogenic diet
24.  Screening of Dihydropyrimidine Dehydrogenase Genetic Variants by Direct Sequencing in Different Ethnic Groups 
Journal of Korean Medical Science  2013;28(8):1129-1133.
Dihydropyrimidine dehydrogenase (DPYD) is an enzyme that regulates the rate-limiting step in pyrimidine metabolism, especially catabolism of fluorouracil, a chemotherapeutic agent for cancer. In order to determine the genetic distribution of DPYD, we directly sequenced 288 subjects from five ethnic groups (96 Koreans, 48 Japanese, 48 Han Chinese, 48 African Americans, and 48 European Americans). As a result, 56 polymorphisms were observed, including 6 core polymorphisms and 18 novel polymorphisms. Allele frequencies were nearly the same across the Asian populations, Korean, Han Chinese and Japanese, whereas several SNPs showed different genetic distributions between Asians and other ethnic populations (African American and European American). Additional in silico analysis was performed to predict the function of novel SNPs. One nonsynonymous SNP (+199381A > G, Asn151Asp) was predicted to change its polarity of amino acid (Asn, neutral to Asp, negative). These findings would be valuable for further research, including pharmacogenetic and drug responses studies.
PMCID: PMC3744698  PMID: 23960437
Ethnic Gropus; Pharmacogenetics; Dihydropyrimidine Dehydrogenase; Fluorouracil
25.  Therapeutic Effect of the Tuber of Alisma orientale on Lipopolysaccharide-Induced Acute Lung Injury 
Although Alisma orientale, an ethnic herb, has been prescribed for treating various diseases in Asian traditional medicine, experimental evidence to support its therapeutic effects is lacking. Here, we sought to determine whether A. orientale has a therapeutic effect on acute lung injury (ALI). Ethanol extract of the tuber of A. orientale (EEAO) was prepared and fingerprinted by HPLC for its constituents. Mice received an intraperitoneal (i.p.) injection of lipopolysaccharide (LPS) for the induction of ALI. At 2 h after LPS treatment, mice received an intratracheal (i.t.) spraying of various amounts of EEAO to the lung. Bioluminescence imaging of transgenic NF-κB/luciferase reporter mice shows that i.t. EEAO posttreatment suppressed lung inflammation. In similar experiments with C57BL/6 mice, EEAO posttreatment significantly improved lung inflammation, as assessed by H&E staining of lung sections, counting of neutrophils in bronchoalveolar lavage fluid, and semiquantitative RT-PCR analyses of proinflammatory cytokines and Nrf2-dependent genes in the inflamed lungs. Furthermore, EEAO posttreatment enhanced the survival of mice that received a lethal dose of LPS. Together, our results provide evidence that A. orientale has a therapeutic effect on ALI induced by sepsis.
PMCID: PMC3745860  PMID: 23983806

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