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Search Results: 1 - 10 of 25294 matches for " Sujeong Lee "
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Valproic Acid Decreases Cell Proliferation and Color Preference in the Zebrafish Larvae  [PDF]
Bongkyu Lee, Sujeong Lee, Miyoung Choi, Chang-Joong Lee
Journal of Biosciences and Medicines (JBM) , 2017, DOI: 10.4236/jbm.2017.512007
Abstract: Valproic acid (VPA) is widely used as an antiepileptic drug or mood stabilizer. In this study, we evaluated the effects of treatment with 2 mM VPA for 3 h on cell proliferation in the telencephalic area of zebrafish larvae using bromodeoxyuridine (BRDU) to label dividing cells. It was demonstrated that 2 mM VPA exposure for 3 h at 2 and 3 days post-fertilization (dpf) larvae decreased cell proliferation in the telencephalic area of 5 dpf larvae. The reduced cell proliferation was not restored at 10 dpf larvae. The quantitative real-time PCR (qRT-PCR) data indicated that mRNA expression levels of WNT signaling pathway-related factors such as β-catenin, LEF1, and gsk3β were altered in the zebrafish larvae treated with 2 mM VPA at 2 and 3 pdf. It was also demonstrated that 2 mM VPA exposure affected color preference of the zebrafish larvae, reducing blue color preference at 5 dpf larvae. The altered color preference was restored at 10 dpf larvae. These results suggest that VPA exposure may cause molecular, cellular, and behavioral alterations in early developmental stage of the zebrafish.
Negative Regulation of the Novel norpAP24 Suppressor, diehard4, in the Endo-lysosomal Trafficking Underlies Photoreceptor Cell Degeneration
Jongwoo Lee ,Myungchul Song,Sujeong Hong
PLOS Genetics , 2013, DOI: 10.1371/journal.pgen.1003559
Abstract: Rhodopsin has been used as a prototype system to investigate G protein-coupled receptor (GPCR) internalization and endocytic sorting mechanisms. Failure of rhodopsin recycling upon light activation results in various degenerative retinal diseases. Accumulation of internalized rhodopsin in late endosomes and the impairment of its lysosomal degradation are associated with unregulated cell death that occurs in dystrophies. However, the molecular basis of rhodopsin accumulation remains elusive. We found that the novel norpAP24 suppressor, diehard4, is responsible for the inability of endo-lysosomal rhodopsin trafficking and retinal degeneration in Drosophila models of retinal dystrophies. We found that diehard4 encodes Osiris 21. Loss of its function suppresses retinal degeneration in norpAP24, rdgC306, and trp1, but not in rdgB2, suggesting a common cause of photoreceptor death. In addition, the loss of Osiris 21 function shifts the membrane balance between late endosomes and lysosomes as evidenced by smaller late endosomes and the proliferation of lysosomal compartments, thus facilitating the degradation of endocytosed rhodopsin. Our results demonstrate the existence of negative regulation in vesicular traffic between endosomes and lysosomes. We anticipate that the identification of additional components and an in-depth description of this specific molecular machinery will aid in therapeutic interventions of various retinal dystrophies and GPCR-related human diseases.
Synthesis of Pregnane Derivatives, Their Cytotoxicity on LNCap and PC-3 Cells, and Screening on 5α-Reductase Inhibitory Activity
Sujeong Kim,Eunsook Ma
Molecules , 2009, DOI: 10.3390/molecules14114655
Abstract: A series of epoxy- and/or 20-oxime pregnanes were synthesized from commercially available pregnenolone. Compounds 1, 3, 7, 8 and 11-13 were evaluated for cytotoxicity activity towards LNCaP (androgen-dependent) and PC-3 (androgenindependent) prostate cancer cells. Compound 13 showed the highest activity on both LNCaP (IC50 15.17 μM) and PC-3 (IC50 11.83 μM) cell lines. Compound 11 showed weak activity on LNCaP cells (IC50 71.85 μM) and 8 showed the weak activity on PC-3 cells (IC50 68.95 μM), respectively. The 5α-reductase II (5AR2) inhibitory effects of compounds 1-3, 5 and 7-13 were investigated in a convenient screening model, in which compounds 5, 8, 11 and 12 were observed to be potential inhibitors of 5α-reductase, in particular, the 4-azasteroid 11, that also inhibited cell proliferation of androgen-dependent cells and 8, that in addition inhibited PC-3 cells more potently than LNCaP cells.
The Effectiveness of Automatic Recommending System for Premedication in Reducing Recurrent Radiocontrast Media Hypersensitivity Reactions
Yun-Jeong Bae, Ye Won Hwang, Sun-young Yoon, Sujeong Kim, Taehoon Lee, Yoon Su Lee, Hyouk-Soo Kwon, You Sook Cho, Myung Jin Shin, Hee-Bom Moon, Tae-Bum Kim
PLOS ONE , 2013, DOI: 10.1371/journal.pone.0066014
Abstract: Background Non-ionic radiocontrast media (RCM) is rarely associated with hypersensitivity reactions. Premedication of patients who reacted previously to RCM with systemic corticosteroids and/or antihistamines can help reduce recurrent hypersensitivity reactions. However, premedication is still not prescribed in many cases for various reasons. This study aimed to determine the effectiveness of our novel RCM hypersensitivity surveillance and automatic recommending system for premedication. Methods and Results Hospitalized patients with a history of RCM hypersensitivity were identified in an electronic medical record system that included a mandatory reporting system for past adverse drug reactions. In 2009, a novel automatic prescription system was added that classified index RCM reactions by severity and dispensed appropriate corticosteroid and/or antihistamine pretreatment prior to new RCM exposures. The data from 12 months under the previous system and 12 months under the current system were compared. The two systems had similar overall premedication rates (91% and 95%) but the current system was associated with a significantly higher corticosteroid premedication rate (65% vs. 14%), which significantly reduced the breakthrough reaction rate (6.7% vs. 15.2%). The current system was also associated with increased corticosteroid and antihistamine premedication of patients with a mild index reaction (61% vs. 7%) and a reduction in their breakthrough reaction rate (6% vs. 15%). Conclusions Premedication with corticosteroid and/or antihistamine, which was increased by our novel automatic prescription system, significantly reduced breakthrough reactions in patients with a history of RCM hypersensitivity.
Influence of Initial Treatment Modality on Long-Term Control of Chronic Idiopathic Urticaria
Sujeong Kim, Seunghee Baek, Bomi Shin, Sun-young Yoon, So Young Park, Taehoon Lee, Yoon Su Lee, Yun-Jeong Bae, Hyouk Soo Kwon, You Sook Cho, Hee-Bom Moon, Tae-Bum Kim
PLOS ONE , 2013, DOI: 10.1371/journal.pone.0069345
Abstract: Background Chronic idiopathic urticaria (CIU) is a common cutaneous disorder but the influence of initial treatment modality on long-term control is not known. The aim of this study was to evaluate clinical features, and the influence of initial treatment modality on long-term control. Methods and Results 641 CIU patients were enrolled from the allergy clinic in a tertiary referral hospital. Disease duration, aggravating factors and treatment modality at each visit were evaluated. Times required to reach a controlled state were analyzed according to initial treatment modality, using Kaplan-Meier survival curves, the Cox proportional-hazards model, and propensity scores. Female to male ratio was 1.7: 1; mean age at onset was 40.5 years. The most common aggravating factors were food (33.5%), stress (31.5%) and fatigue (21.6%). Most patients (82.2%) used H1-antihistamines alone as initial treatment while 17% used a combination treatment with oral corticosteroids. There was no significant difference in the time taken to reach a controlled state between patients treated with single vs multiple H1-antihistamines or between those who received H1-antihistamine monotherapy vs. a combination therapy with oral corticosteroids. Conclusion The time required to control CIU is not reduced by use of multiple H1-antihistamines or oral corticosteroids in the initial treatment.
Vascular Disrupting Agent Drug Classes Differ in Effects on the Cytoskeleton
Sujeong Kim, Leonid Peshkin, Timothy J. Mitchison
PLOS ONE , 2012, DOI: 10.1371/journal.pone.0040177
Abstract: Vascular disrupting agents (VDAs), anti-cancer drugs that target established tumor blood vessels, fall into two main classes: microtubule targeting drugs, exemplified by combretastatin A4 (CA4), and flavonoids, exemplified by 5,6-dimethylxanthenone-4-acetic acid (DMXAA). Both classes increase permeability of tumor vasculature in mouse models, and DMXAA in particular can cause massive tumor necrosis. The molecular target of CA4 is clearly microtubules. The molecular target(s) of DMXAA remains unclear. It is thought to promote inflammatory signaling in leukocytes, and has been assumed to not target microtubules, though it is not clear from the literature how carefully this assumption has been tested. An earlier flavone analog, flavone acetic acid, was reported to promote mitotic arrest suggesting flavones might possess anti-microtubule activity, and endothelial cells are sensitive to even mild disruption of microtubules. We carefully investigated whether DMXAA directly affects the microtubule or actin cytoskeletons of endothelial cells by comparing effects of CA4 and DMXAA on human umbilical vein endothelial cells (HUVEC) using time-lapse imaging and assays for cytoskeleton integrity. CA4 caused retraction of the cell margin, mitotic arrest and microtubule depolymerization, while DMXAA, up to 500 μM, showed none of these effects. DMXAA also had no effect on pure tubulin nucleation and polymerization, unlike CA4. We conclude that DMXAA exhibits no direct anti-microtubule action and thus cleanly differs from CA4 in its mechanism of action at the molecular level.
Synthesis and 5α-Reductase Inhibitory Activity of C21 Steroids Having 1,4-diene or 4,6-diene 20-ones and 4-Azasteroid 20-Oximes
Sujeong Kim,Yong-ung Kim,Eunsook Ma
Molecules , 2012, DOI: 10.3390/molecules17010355
Abstract: The synthesis and evaluation of 5α-reductase inhibitory activity of some 4-azasteroid-20-ones and 20-oximes and 3β-hydroxy-, 3β-acetoxy-, or epoxy-substituted C21 steroidal 20-ones and 20-oximes having double bonds in the A and/or B ring are described. Inhibitory activity of synthesized compounds was assessed using 5α-reductase enzyme and [1,2,6,7-3H]testosterone as substrate. All synthesized compounds were less active than finasteride (IC50: 1.2 nM). Three 4-azasteroid-2-oximes (compounds 4, 6 and 8) showed good inhibitory activity (IC50: 26, 10 and 11 nM) and were more active than corresponding 4-azasteroid 20-ones (compounds 3, 5 and 7). 3β-Hydroxy-, 3β-acetoxy- and 1α,2α-, 5α,6α- or 6α,7α-epoxysteroid-20-one and -20-oxime derivatives having double bonds in the A and/or B ring showed no inhibition of 5α-reductase enzyme.
Functional neural differentiation of human adipose tissue-derived stem cells using bFGF and forskolin
Sujeong Jang, Hyong-Ho Cho, Yong-Bum Cho, Jong-Seong Park, Han-Seong Jeong
BMC Cell Biology , 2010, DOI: 10.1186/1471-2121-11-25
Abstract: Human ADSCs from earlobe fat maintained self-renewing capacity and differentiated into adipocytes, osteoblasts, or chondrocytes under specific culture conditions. Following neural induction with bFGF and forskolin, hADSCs were differentiated into various types of neural cells including neurons and glia in vitro. In neural differentiated-hADSCs (NI-hADSCs), the immunoreactivities for neural stem cell marker (nestin), neuronal markers (Tuj1, MAP2, NFL, NFM, NFH, NSE, and NeuN), astrocyte marker (GFAP), and oligodendrocyte marker (CNPase) were significantly increased than in the primary hADSCs. RT-PCR analysis demonstrated that the mRNA levels encoding for ABCG2, nestin, Tuj1, MAP2, NFL, NFM, NSE, GAP43, SNAP25, GFAP, and CNPase were also highly increased in NI-hADSCs. Moreover, NI-hADSCs acquired neuron-like functions characterized by the display of voltage-dependent tetrodotoxin (TTX)-sensitive sodium currents, outward potassium currents, and prominent negative resting membrane potentials under whole-cell patch clamp recordings. Further examination by RT-PCR showed that NI-hADSCs expressed high level of ionic channel genes for sodium (SCN5A), potassium (MaxiK, Kv4.2, and EAG2), and calcium channels (CACNA1C and CACNA1G), which were expressed constitutively in the primary hADSCs. In addition, we demonstrated that Kv4.3 and Eag1, potassium channel genes, and NE-Na, a TTX-sensitive sodium channel gene, were highly induced following neural differentiation.These combined results indicate that hADSCs have the same self-renewing capacity and multipotency as stem cells, and can be differentiated into functional neurons using bFGF and forskolin.Stem cell-based therapies for the repair and regeneration of various tissues and organs offer a paradigm shift that may lead to alternative therapeutic solutions for a number of diseases. The emerging field of regenerative medicine requires reliable sources of stem cells, biomaterial scaffolds and cytokine growth factors. A stem cell i
The Relationship between Visual Satisfaction and Water Clarity and Quality Management in Tourism Fishing Ports  [PDF]
Lee-Hsueh Lee
Journal of Water Resource and Protection (JWARP) , 2016, DOI: 10.4236/jwarp.2016.88064
Abstract: Visual satisfaction of the tourists with a water body is strongly influenced by water clarity, which is in turn influenced by a number of water quality parameters. Visual satisfaction thus stands to benefit from having a water quality management tool that results in better water clarity. A Clarity Suitability Index of Water Quality (CSIWQ), derived from clarity suitability curves of selected water quality parameters, can allow estimation of optimal values for these parameters, while ensuring high visual satisfaction among tourists. The present study used sampling and survey methodologies to investigate water clarity and quality at five tourism fishing ports; simultaneously, tourists’ visual satisfaction with a water body was assessed through a questionnaire based on their perceptions. The relationship between tourists’ visual satisfaction and water clarity was found to be positive and strong, with water clarity having predictive power of 74.2%. The study showed that DO, BOD, TP, and SS were the most critical parameters for water clarity. A continued product approach of CSIWQ was found to be most appropriate for describing the relationship between water clarity and these four parameters. This enabled a CSIWQ Index value to be calculated. With a CSIWQ value of 0.6, water clarity would be more than 2.08 m, and tourists would experience very high satisfaction. CSI curves showed that DO would preferably be 9.0 mg/L, and BOD, TP, and SS less than 0.5 mg/L, 0.12 mg/L, and 45.0 mg/L, respectively. The model thus produced valuable insights for assessing and improving water quality and ensuring high levels of visual satisfaction among tourists in tourism fishing ports. This model identified only four parameters but could be improved by ensuring that other water quality parameters were included, to encourage an increase in the number of tourists and to include monitoring of more pollutant sources.
Appearance’s Aesthetic Appreciation to Inform Water Quality Management of Waterscapes  [PDF]
Lee-Hsueh Lee
Journal of Water Resource and Protection (JWARP) , 2017, DOI: 10.4236/jwarp.2017.913103
Abstract:
The appearance of the water is just one aspect of a waterscape that can be appreciated aesthetically. Water appearance is affected by water clarity and water colour. Here, an aesthetic assessment model of waterscape was suggested. In the model, water clarity and colour have direct effects, whereas water quality and phytoplankton biomass have indirect effects, on tourists’ aesthetic assessment of water bodies. The preferred water colour is aquamarine to blue, regardless of depth of clarity. Water colour ranges from pastel yellow to yellow-green are not favoured by tourists. Four water-quality parameters were correlated with water clarity and phytoplankton biomass. The coefficient of indirect effect of river pollution index on tourists’ aesthetic valuation of aquamarine to blue water colour was -0.457, and for pastel yellow to yellowgreen, it was -0.209. The research results showed observation of water colour could not only reflect waterscape aesthetic value, but also serve as a guide of judging water quality, and the status of phytoplankton benefited to simplify the process of water-quality management for waterscape.
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