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1.  Downregulation of Angiotensin II-Induced 12-Lipoxygenase Expression and Cell Proliferation in Vascular Smooth Muscle Cells from Spontaneously Hypertensive Rats by CCL5 
Angiotensin II (Ang II) plays an important role in vascular hypertension. The role of the chemokine CCL5 on Ang II-induced activities in vascular smooth muscle cells (VSMCs) has not been studied. In this study, we elucidated the effect of CCL5 on Ang II-induced 12-lipoxygenase (LO) expression and cell proliferation in spontaneously hypertensive rats (SHR) VSMCs. CCL5 decreased Ang II-induced 12-LO mRNA expression and protein production, and it increased Ang II type 2 (AT2) receptor expression in SHR VSMCs. The inhibitory effect of CCL5 on Ang II-induced 12-LO mRNA expression was mediated through the AT2 receptor. Although treatment of CCL5 alone induced SHR VSMCs proliferation, CCL5 inhibited Ang II-induced VSMCs proliferation and PD123,319, an AT2 receptor antagonist, blocked the inhibitory effect of CCL5 on Ang II-induced VSMCs proliferation. Phosphorylation of p38 was detected in VSMCs treated with Ang II or CCL5 alone. But, decrease of p38 phosphorylation was detected in VSMCs treated with Ang II and CCL5 simultaneously (Ang II/CCL5) and PD123,319 increased p38 phosphorylation in VSMCs treated with Ang II/CCL5. Therefore, these results suggest that the inhibitory effect of CCL5 on Ang II-induced VSMCs proliferation is mediated by the AT2 receptor via p38 inactivation, and CCL5 may play a beneficial role in Ang II-induced vascular hypertension.
doi:10.4196/kjpp.2009.13.5.385
PMCID: PMC2776900  PMID: 19915702
Angiotensin II; Angiotensin II type 2 receptor; Cell proliferation; Chemokine CCL5; 12-lipoxygenase
2.  Finite element modeling technique for predicting mechanical behaviors on mandible bone during mastication 
PURPOSE
The purpose of this study was to propose finite element (FE) modeling methods for predicting stress distributions on teeth and mandible under chewing action.
MATERIALS AND METHODS
For FE model generation, CT images of skull were translated into 3D FE models, and static analysis was performed considering linear material behaviors and nonlinear geometrical effect. To find out proper boundary and loading conditions, parametric studies were performed with various areas and directions of restraints and loading. The loading directions are prescribed to be same as direction of masseter muscle, which was referred from anatomy chart and CT image. From the analysis, strain and stress distributions of teeth and mandible were obtained and compared with experimental data for model validation.
RESULTS
As a result of FE analysis, the optimized boundary condition was chosen such that 8 teeth were fixed in all directions and condyloid process was fixed in all directions except for forward and backward directions. Also, fixing a part of mandible in a lateral direction, where medial pterygoid muscle was attached, gave the more proper analytical results. Loading was prescribed in a same direction as masseter muscle. The tendency of strain distributions between the teeth predicted from the proposed model were compared with experimental results and showed good agreements.
CONCLUSION
This study proposes cost efficient FE modeling method for predicting stress distributions on teeth and mandible under chewing action. The proposed modeling method is validated with experimental data and can further be used to evaluate structural safety of dental prosthesis.
doi:10.4047/jap.2012.4.4.218
PMCID: PMC3517960  PMID: 23236574
Mandible; Stress distribution; Mastication; Finite element analysis
3.  Augmentation of natural cytotoxicity by chronic low-dose ionizing radiation in murine natural killer cells primed by IL-2 
Journal of Radiation Research  2012;53(6):823-829.
The possible beneficial effects of chronic low-dose irradiation (LDR) and its mechanism of action in a variety of pathophysiological processes such as cancer are a subject of intense investigation. While animal studies involving long-term exposure to LDR have yielded encouraging results, the influence of LDR at the cellular level has been less well defined. We reasoned that since natural killer (NK) cells constitute an early responder to exogenous stress, NK cells may reveal sentinel alterations in function upon exposure to LDR. When purified NK cells received LDR at 4.2 mGy/h for a total of 0.2 Gy in vitro, no significant difference in cell viability was observed. Likewise, no functional changes were detected in LDR-exposed NK cells, demonstrating that LDR alone was insufficient to generate changes at the cellular level. Nonetheless, significant augmentation of cytotoxic, but not proliferative, function was detected when NK cells were stimulated with low-dose IL-2 prior to irradiation. This enhancement of NK cytotoxicity was not due to alterations in NK-activating receptors, NK1.1, NKG2D, CD69 and 2B4, or changes in the rate of early or late apoptosis. Therefore, LDR, in the presence of suboptimal cytokine levels, can facilitate anti-tumor cytotoxicity of NK cells without influencing cellular proliferation or apoptosis. Whether these results translate to in vivo consequences remains to be seen; however, our data provide initial evidence that exposure to LDR can lead to subtle immune-enhancing effects on NK cells and may explain, in part, the functional basis underlying, diverse beneficial effects seen in the animals chronically exposed to LDR.
doi:10.1093/jrr/rrs037
PMCID: PMC3483842  PMID: 22915781
Low-dose radiation; natural killer cells; natural cytotoxicity; innate immunity
4.  Inorganic sulfur reduces the motility and invasion of MDA-MB-231 human breast cancer cells 
Nutrition Research and Practice  2011;5(5):375-380.
This study investigated the effects of inorganic sulfur on metastasis in MDA-MB-231 human breast cancer cells. MDA-MB-231 cells were cultured in the absence or presence of various concentrations (12.5, 25, or 50 µmol/L) of inorganic sulfur. Cell motility, invasion, and the activity and mRNA expression of matrix metalloproteases (MMPs) were examined. Numbers of viable MDA-MB-231 cells did not differ by inorganic sulfur treatment from 0 to 50 µmol/L within 48 h. Inorganic sulfur significantly decreased cell motility and invasion in the MDA-MB-231 cells in a dose-dependent manner (P < 0.05), as determined using a Boyden chamber assay and a Matrigel chamber. The activities of MMP-2 and MMP-9 were significantly reduced by inorganic sulfur in a dose-dependent manner (P < 0.05). The inorganic sulfur also significantly inhibited MMP-2 and MMP-9 expression in the cells (P < 0.05). These data suggest that inorganic sulfur can suppress cancer cell motility and invasion by inhibiting MMP-2 and MMP-9 activity and gene expression in MDA-MB-231 cells.
doi:10.4162/nrp.2011.5.5.375
PMCID: PMC3221821  PMID: 22125673
Inorganic sulfur; invasion; motility; matrix metalloprotease; MDA-MB-231 cells
5.  Cilostazol Inhibits Vascular Smooth Muscle Cell Proliferation and Reactive Oxygen Species Production through Activation of AMP-activated Protein Kinase Induced by Heme Oxygenase-1 
Cilostazol is a selective inhibitor of phosphodiesterase 3 that increases intracellular cAMP levels and activates protein kinase A, thereby inhibiting vascular smooth muscle cell (VSMC) proliferation. We investigated whether AMP-activated protein kinase (AMPK) activation induced by heme oxygenase-1 (HO-1) is a mediator of the beneficial effects of cilostazol and whether cilostazol may prevent cell proliferation and reactive oxygen species (ROS) production by activating AMPK in VSMC. In the present study, we investigated VSMC with various concentrations of cilostazol. Treatment with cilostazol increased HO-1 expression and phosphorylation of AMPK in a dose- and time-dependent manner. Cilostazol also significantly decreased platelet-derived growth factor (PDGF)-induced VSMC proliferation and ROS production by activating AMPK induced by HO-1. Pharmacological and genetic inhibition of HO-1 and AMPK blocked the cilostazol-induced inhibition of cell proliferation and ROS production.These data suggest that cilostazol-induced HO-1 expression and AMPK activation might attenuate PDGF-induced VSMC proliferation and ROS production.
doi:10.4196/kjpp.2011.15.4.203
PMCID: PMC3186921  PMID: 21994478
Cilostazol; Proliferation; ROS; AMPK; HO-1
6.  Impact of Nocturia on Health-Related Quality of Life and Medical Outcomes Study Sleep Score in Men 
Purpose
To evaluate the impact of nocturia on health-related quality of life and sleep in men.
Methods
From January 2008 to December 2008, 284 patients with lower urinary tract symptoms were selected for this study. The participants completed a series of questionnaires on health-related quality of life (the overactive bladder questionnaire, or OAB-q), the Medical Outcomes Study (MOS) sleep scale, and the frequency volume chart.
Results
The patient population had a mean age of 60.0±13.4 years (range, 40 to 79 years). The mean duration of symptoms was 28.8±34.6 months. The mean number of voiding episodes per night was measured as follows: 88 patients (31.0%) reported no nocturia, 60 patients (21.1%) reported 2>voids/night ≥1, 56 patients (19.7%) reported 3>voids/night ≥2, and 80 patients (28.2%) reported ≥3 voids/night. The mean number of nocturia episodes increased with age (P=0.001), and the number of nocturia episodes was significantly associated with the OAB-q symptom score (P=0.001) and symptom bother (P=0.001). Among the categories of the MOS sleep scale, sleep index I (P=0.020), sleep disturbance (P=0.010), adequacy of sleep (P=0.005), and somnolence (P=0.041) were significantly associated with an increased number of nocturia episodes.
Conclusions
The number of nocturia episodes increased with age in men. Nocturia appeared to be associated with further negative effects on sleep quality, health-related quality of life, and symptom bother.
doi:10.5213/inj.2011.15.2.82
PMCID: PMC3138848  PMID: 21811697
Nocturia; Sleep; Quality of life
7.  Butin (7,3′,4′-Trihydroxydihydroflavone) Reduces Oxidative Stress-Induced Cell Death via Inhibition of the Mitochondria-Dependent Apoptotic Pathway 
Recently, we demonstrated that butin (7,3′,4′-trihydroxydihydroflavone) protected cells against hydrogen peroxide (H2O2)-induced apoptosis by: (1) scavenging reactive oxygen species (ROS), activating antioxidant enzymes such superoxide dismutase and catalase; (2) decreasing oxidative stress-induced 8-hydroxy-2′-deoxyguanosine levels via activation of oxoguanine glycosylase 1, and (3), reducing oxidative stress-induced mitochondrial dysfunction. The objective of this study was to determine the cytoprotective effects of butin on oxidative stress-induced mitochondria-dependent apoptosis, and possible mechanisms involved. Butin significantly reduced H2O2-induced loss of mitochondrial membrane potential as determined by confocal image analysis and flow cytometry, alterations in Bcl-2 family proteins such as decrease in Bcl-2 expression and increase in Bax and phospho Bcl-2 expression, release of cytochrome c from mitochondria into the cytosol and activation of caspases 9 and 3. Furthermore, the anti-apoptotic effect of butin was exerted via inhibition of mitogen-activated protein kinase kinase-4, c-Jun NH2-terminal kinase (JNK) and activator protein-1 cascades induced by H2O2 treatment. Finally, butin exhibited protective effects against H2O2-induced apoptosis, as demonstrated by decreased apoptotic bodies, sub-G1 hypodiploid cells and DNA fragmentation. Taken together, the protective effects of butin against H2O2-induced apoptosis were exerted via blockade of membrane potential depolarization, inhibition of the JNK pathway and mitochondria-involved caspase-dependent apoptotic pathway.
doi:10.3390/ijms12063871
PMCID: PMC3131597  PMID: 21747713
butin; oxidative stress; mitochondria-dependent apoptotic pathway
8.  Age Related Change of Nocturia in Women 
Purpose
The precise etiology and classification of nocturia in women is not enough. We evaluated age related changes and classified the type of nocturia by age in women.
Methods
We included 118 women 20 years or older with nocturia at least one time during night time. Subjects were divided into three groups by the age: group 1, under 40 years; group 2, 40 through 59 years; group 3, 60 years and above. The causes of nocturia and its pattern changed by age in women were evaluated using 3 days frequency volume chart. Nocturia was devided into three types: nocturnal polyuria, decreased nocturnal bladder capacity and mixed type.
Results
The mean age was 57.2±11.8 and the mean nocturnal frequency was 2.7±1.8. In all age group, noctural polyuria was the major cause for noturia (40.8%), followed by low nocturnal bladder capacity (23.7%). As a major cause of nocturia, there was a significant increase of the incidence of nocturnal polyuria in aged people: group 1, 32.4%; group 2, 41.0%; group 3: 47.6% (P<0.04).
Conclusions
Nocturnal polyuria and decreased nocturnal bladder capacity are the major causes of nocturia in women. Nocturnal polyuria was the major cause of nocturia with age over 60 years old. In aged women, nocturnal polyuria should be considered as a main cuase of nocturia and treated based on these result.
doi:10.5213/inj.2010.14.4.245
PMCID: PMC3021816  PMID: 21253336
Nocturia; Women; Age
9.  The Reliability and Validity of the Korean Version of the Structured Interview for Prodromal Syndrome 
Psychiatry Investigation  2010;7(4):257-263.
Objective
The Structured Interview for Prodromal Syndrome (SIPS) from Yale University is intended to diagnose prodromal syndrome of psychosis and to measure the severity of prodromal symptoms. Here, a Korean version of SIPS is presented, and its reliability, validity, and factor structures are examined using a representative Korean sample.
Methods
The Korean version of SIPS was administered to 40 participants over a period of 1 year. The inter-rater reliability and internal consistency of the SIPS were then evaluated. In addition, its factor structure was investigated using principal-axis factor analysis. Concurrent validity was explored using Pearson correlation coefficients with the Positive and Negative Syndrome Scale (PANSS).
Results
Of the 40 subjects, 12.5% developed psychotic disorders during the 1-year follow-up period. Inter-rater reliability was good (intra-class correlations=0.96), and internal consistency was acceptable (Cronbach's alpha=0.83). A three-factor resolution displayed the best simple structure and accounted for 52.6% of all item variance. Factors 1 and 2 showed strong correlations with negative symptoms and cognitive dysfunction, respectively, on the PANSS. Factor 3 was not correlated with any factor on the PANSS.
Conclusion
The Korean version of SIPS is a reliable instrument for the assessment of prodromal symptoms in subjects and may be used to evaluate prodromal psychosis.
doi:10.4306/pi.2010.7.4.257
PMCID: PMC3022312  PMID: 21253409
The Korean version of the Structured Interview for Prodromal Syndrome; Reliability; Validity; Schizophrenia
10.  Increased Immunoendocrine Cells in Intestinal Mucosa of Postinfectious Irritable Bowel Syndrome Patients 3 Years after Acute Shigella Infection - An Observation in a Small Case Control Study 
Yonsei Medical Journal  2009;51(1):45-51.
Purpose
Postinfectiously irritable bowel syndrome (PI-IBS) develops in 3-30% of individuals with bacterial gastroenteritis. Recent studies demonstrated increases in inflammatory components in gut mucosa of PI-IBS patients even after complete resolution of infection. We aimed to investigate histological changes in colon and rectum of PI-IBS subjects after long term period of infection.
Materials and Methods
We recruited PI-IBS subjects who had been diagnosed IBS after complete resolution of enteritis caused by shigellosis outbreak 3 years earlier. We compared unmatched four groups, PI-IBS (n = 4), non PI-IBS (n = 7), D-IBS (n = 7, diarrhea predominant type) and healthy controls (n = 10). All of them underwent colonoscopic biopsy at three areas, including descending colon (DC), sigmoid colon (SC) and rectum, which were assessed for 5-hydroxytryptamine (5-HT)/peptide YY (PYY)-containing enterochromaffin (EC) cell, intraepithelial (IEL) and lamina propria T lymphocyte (CD3), CD8 lymphocytes, mast cells and CD68/calprotectin+ macrophages.
Results
All subjects had no structural or gross abnormalities at colonoscopy. In PI-IBS, 5-HT containing EC cells, PYY containing EC cells, IELs, CD3 lymphocytes, CD8 lymphocytes, mast cells, and CD68 + macrophages were increased compared to control (p < 0.05). In D-IBS, PYY containing EC cells, IELs, and CD3 lymphocytes were increased compared to control (p < 0.05). In PI-IBS, 5-HT containing EC cells tended to increase and PYY containing EC cells, CD8 lymphocytes, mast cells, and CD68+ macrophages were increased compared to non PI-IBS (p < 0.05). Calprotectin + marcrophages were decreased in PI-IBS, non PI-IBS and IBS compared to control.
Conclusion
The immunoendocrine cells were sporadically increased in PI-IBS, non PI-IBS and D-IBS compared with control. Our findings in a very small number of patients suggest that mucosal inflammation may play a role in long-term PI-IBS, and that other sub-groups of IBS and larger scale studies are needed to confirm this observation.
doi:10.3349/ymj.2010.51.1.45
PMCID: PMC2799963  PMID: 20046513
Post infectious irritable bowel syndrome; enterochromaffin cell; T lymphocyte; mast cell; macrophage
11.  Compound K, a Metabolite of Ginseng Saponin, Induces Mitochondria-Dependent and Caspase-Dependent Apoptosis via the Generation of Reactive Oxygen Species in Human Colon Cancer Cells 
The objective of this study was to elucidate the cytotoxic mechanism of Compound K, with respect to the involvement of reactive oxygen species (ROS) and the mitochondrial involved apoptosis, in HT-29 human colon cancer cells. Compound K exhibited a concentration of 50% growth inhibition (IC50) at 20 μg/mL and cytotoxicity in a time dependent manner. Compound K produced intracellular ROS in a time dependent fashion; however, N-acetylcysteine (NAC) pretreatment resulted in the inhibition of this effect and the recovery of cell viability. Compound K induced a mitochondria-dependent apoptotic pathway via the modulation of Bax and Bcl-2 expressions, resulting in the disruption of the mitochondrial membrane potential (Δψm). Loss of the Δψm was followed by cytochrome c release from the mitochondria, resulting in the activation of caspase-9, -3, and concomitant poly ADP-ribosyl polymerase (PARP) cleavage, which are the indicators of caspase-dependent apoptosis. The apoptotic effect of Compound K, exerted via the activation of c-Jun NH2-terminal kinase (JNK) and p38 mitogen-activated protein kinase (MAPK), was abrogated by specific MAPK inhibitors. This study demonstrated that Compound K-mediated generation of ROS led to apoptosis through the modulation of a mitochondria-dependent apoptotic pathway and MAPK pathway.
doi:10.3390/ijms11124916
PMCID: PMC3100836  PMID: 21614182
Compound K; reactive oxygen species; mitochondrial membrane potential; c-Jun NH2-terminal kinase; p38 mitogen-activated protein kinase
12.  Evaluation of proximal contact strength by postural changes 
STATEMENT OF PROBLEM
Proper proximal contact is important for maintaining and stabilizing the dental arch. However, the proximal contact strength (PCS) is not a constant value and can be affected by a variety of factors.
PURPOSE
This study examined the influences of postural changes on the posterior PCS.
MATERIAL AND METHODS
Twelve adults with a normal occlusion and had not undergone prosthetic treatment or proximal restoration were participated in this study. A metal strip was inserted into the proximal surface and removed at a constant velocity. The contact strength was measured in every contact point between canine to second molar in both arches. The PCSs were obtained initially in the upright position, secondly in the supine position and finally in the upright position again. All measurements were repeated after a 2 hour period. Statistical analysis was carried out using the Friedman test (P < .05).
RESULTS
Generally, a decrease in PCS occurred when the posture was changed from the initial upright to supine position, while it increased when the posture was changed from the supine to upright position. A significant change was observed in all areas except for between the canine-first premolar in the maxilla and between the first molarsecond molar in the mandible areas.
CONCLUSION
The posterior PCS, which dentists generally believe to be a static feature of occlusion, is affected significantly by posture.
doi:10.4047/jap.2009.1.3.118
PMCID: PMC2994688  PMID: 21165266
Proximal contact strength; Upright position; Supine position
13.  IL-8/CXCL8 Upregulates 12-Lipoxygenase Expression in Vascular Smooth Muscle Cells from Spontaneously Hypertensive Rats 
Background
We previously demonstrated remarkable differences in the expression of IL-8/CXCL8 in aortic tissues and vascular smooth muscle cells (VSMC) from spontaneously hypertensive rats (SHR) compared to VSMC from normotensive Wistar-Kyoto rats (WKY). In the present study, we investigated the direct effect of IL-8/CXCL8 on expression of 12-lipoxygenase (LO), a hypertensive modulator, in SHR VSMC.
Methods
Cultured aortic VSMC from SHR and WKY were used. Expression of 12-LO mRNA was determined by real-time polymerase chain reaction. Phosphorlyation of ERK1/2 and production of 12-LO and angiotensin II subtype 1 (AT1) receptor were assessed by Western blots. IL-8/CXCL8-stimulated DNA synthesis was determined by measuring incorporation of [3H]-thymidine. And effect of IL-8/CXCL8 on vascular tone was determined by phenylephrine-induced contraction of thoracic aortic rings.
Results
Treatment with IL-8/CXCL8 greatly increased 12-LO mRNA expression and protein production compared to treatment with angiotensin II. IL-8/CXCL8 also increased the expression of the AT1 receptor. The increase in 12-LO induced by IL-8/CXCL8 was inhibited by treatment with an AT1 receptor antagonist. The induction of 12-LO mRNA production and the proliferation of SHR VSMC by IL-8/CXCL8 was mediated by the ERK pathway. The proliferation of SHR VSMC and the vascular contraction in the thoracic aortic ring, both of which were induced by IL-8/CXCL8, were inhibited by baicalein, a 12-LO inhibitor.
Conclusion
These results suggest that the potential role of IL-8/CXCL8 in hypertensive processes is likely mediated through the 12-LO pathway.
doi:10.4110/in.2009.9.3.106
PMCID: PMC2803299  PMID: 20107540
IL-8/CXCL8; 12-lipoxygenase; rat vascular smooth muscle cell
14.  15-Deoxy-Δ12,14-Prostaglandin J2 Upregulates the Expression of LPS-Induced IL-8/CXCL8 mRNA in Vascular Smooth Muscle Cells from Spontaneously Hypertensive Rats 
Background
15d-PGJ2 has been known to act as an anti-inflammatory agent and has anti-hypertensive effects. As a result of these properties, we examined the effect of 15d-PGJ2 on the LPS-induced IL-8/CXCL8 mRNA expression in VSMCs from SHR.
Methods
Effect and action mechanism of 15d-PGJ2 on the expression of LPS-induced IL-8/CXCL8 mRNA in VSMCs from SHR and WKY were examined by using real-time polymerase chain reaction, electrophoretic mobility shift assay for NF-κB avtivity, Western blotting analysis for ERK and p38 phosphorylation and flow cytometry for NAD(P)H oxidase activity.
Results
15d-PGJ2 decreased the expression of LPS-induced IL-8/CXCL8 mRNA in WKY VSMCs, but increased the expression of LPS-induced IL-8/CXCL8 mRNA in SHR VSMCs. The upregulatory effect of 15d-PGJ2 in SHR VSMCs was mediated through PPARγ, and dependent on NF-κB activation and ERK phosphorylation. However, inhibition of the p38 signaling pathway augmented the upregulatory effect of 15d-PGJ2 on LPS-induced IL-8/CXCL8 mRNA. A NAD(P)H oxidase inhibitor inhibited the upregulatory effect of 15d-PGJ2 on LPS-induced IL-8/CXCL8 mRNA expression in SHR VSMCs, and an increase in NAD(P)H oxidase activity was detected in SHR VSMCs treated with 15d-PGJ2/LPS.
Conclusion
Our results indicate that the upregulatory effect of 15d-PGJ2 on LPS-induced IL-8/CXCL8 expression in SHR VSMCs is mediated through the PPARγ and ERK pathway, and may be related to NAD(P)H oxidase activity. However, p38 inactivation may also play an important role in 15d-PGJ2/LPS-induced IL-8/CXCL8 expression in SHR VSMCs.
doi:10.4110/in.2009.9.2.64
PMCID: PMC2803308  PMID: 20107546
15d-PGJ2; IL-8/CXCL8; vascular smooth muscle cells
15.  Use of Long-term Cultured Embryoid Bodies May Enhance Cardiomyocyte Differentiation by BMP2 
Yonsei Medical Journal  2008;49(5):819-827.
Purpose
Human embryonic stem cells (hESCs) can proliferate for a prolonged period and differentiate into cardiomyocytes in vitro. Recent studies used bone morphogenetic protein 2 (BMP2) to generate cardiomyocytes from hESCs, however, all those studies used early embryoid bodies (EBs) and did not retrieve cardiomyocytes with a high yield. In this study, we treated long-term cultured EBs with BMP2 in order to promote differentiation into cardiomyocytes from hESCs.
Materials and Methods
hESC lines, including SNUhES3 and SNUhES4, were used in this study. Undifferentiated hESC colonies were detached to form EBs and cultured for up to 30 days. These long-term cultured EBs were differentiated into cardiomyocytes in serum-containing media. In our protocol, BMP2 was applied for 5 days after attachment of EBs. Cardiac specific markers, beating of differentiated cells and electron microscopic (EM) ultrastructures were evaluated and analyzed.
Results
Compared to 10-day or 20-day EBs, 30-day EBs showed a higher expression level of cardiac specific markers, Nkx2.5 and α-myosin heavy chain (αMHC). Treatment of BMP2 increased expression of cardiac troponin (cTn) I and α-actinin when evaluated at 20 days after attachment of 30-day EBs. Beating of differentiated cells was observed from 7 to 20 days after attachment. Moreover, EM findings demonstrated fine structures such as Z bands in these differentiated cardiomyocytes. These long-term cultured EBs yielded cardiomyocytes with an efficiency of as high as 73.6% when assessed by FACS.
Conclusion
We demonstrated that the use of long-term cultured EBs may enhance differentiation into cardiomyocytes from hESCs when treated with BMP2.
doi:10.3349/ymj.2008.49.5.819
PMCID: PMC2615363  PMID: 18972603
Bone morphogenetic protein 2; cardiomyocytes; cell differentiation; embryoid bodies; embryonic stem cells; long-term
16.  Effect of Itopride Hydrochloride on the Ileal and Colonic Motility in Guinea Pig In Vitro 
Yonsei Medical Journal  2008;49(3):472-478.
Purpose
Itopride hydrochloride (itopride) inhibits acetylcholinesterase (AChE) and antagonizes dopamine D2 receptor, and has been used as a gastroprokinetic agent. However, its prokinetic effect on the small bowel or colon has not yet been thoroughly investigated. The aim of this study was to investigate the effects of itopride on motor functions of the ileum and colon in guinea pigs.
Materials and Methods
The distal ileum was excised and the activity of peristaltic contraction was determined by measuring the amplitude and propagation velocity of peristaltic contraction. The distal colon was removed and connected to the chamber containing Krebs-Henseleit solution (K-H solution). Artificial fecal matter was inserted into the oral side of the lumen, and moved toward the anal side by intraluminal perfusion via peristaltic pump. Colonic transit times were measured by the time required for the artificial feces to move a total length of 10 cm with 2-cm intervals.
Results
In the ileum, itopride accelerated peristaltic velocity at higher dosage (10-10-10-6 M) whereas neostigmine accelerated it only with a lower dosage (10-10-10-9 M). Dopamine (10-8 M) decelerated the velocity that was recovered by itopride infusion. Itopride and neostigmine significantly shortened colonic transit at a higher dosage (10-10-10-6 M). Dopamine (10-8 M) delayed colonic transit time that was also recovered after infusion of itopride.
Conclusion
Itopride has prokinetic effects on both the ileum and colon, which are regulated through inhibitory effects on AChE and antagonistic effects on dopamine D2 receptor.
doi:10.3349/ymj.2008.49.3.472
PMCID: PMC2615341  PMID: 18581598
Itopride; acetylcholinesterase inhibitor; dopamine D2 receptor antagonist
17.  Arthroscopic synovectomy in haemophilic arthropathy of the knee 
International Orthopaedics  2005;29(5):296-300.
From January 1996 to January 2001, arthroscopic synovectomies were performed in 28 knees with haemophilic arthropathy. The mean follow-up period was 5 years and 11 months. Six portals (two anterior, two suprapatellar, two posterior) and a posterior trans-septal portal were used in all cases. The average Hospital for Special Surgery (HSS) knee score increased from 56.4 to 71.5 points at the last follow-up. The average frequency of haemarthrosis reduced from five times per month before operation to once per month. The amount of factor replacement decreased from a mean of 4,633 U to 1,505 U. Progression of arthritis was observed radiographically in three cases at the last follow-up. An arthroscopic synovectomy of the knee using appropriate arthroscopic portals is a useful method in treating haemophilic patients as it decreases bleeding episodes, amount of factor replacement and knee pain.
doi:10.1007/s00264-005-0666-2
PMCID: PMC3456637  PMID: 16082543
18.  Simplified EM Grid Vitrification Is a Convenient and Efficient Method for Mouse Mature Oocyte Cryopreservation 
Yonsei Medical Journal  2006;47(3):399-404.
This study was performed to evaluate the efficiency of simplified EM grid vitrification, skipping the step of removing the cryoprotectant (5.5 M EG + 1.0 M sucrose) droplet on the grid after loading oocytes, compared to conventional cryopreservation protocols for mouse mature oocytes. Firstly, the recovery, survival, fertilization and hatching rates of simplified EM grid vitrification were compared with those of the slow freezing method using 1.5 M DMSO. Then, conventional EM grid vitrification was compared with simplified EM grid vitrification. Simplified EM grid vitrification showed higher survival, fertilization and hatching rates than those of the slow freezing method (85.6% vs. 63.2%; 51.0% vs. 22.3%; 38.7% vs. 12.5%, p < 0.01, respectively). Moreover, simplified EM grid vitrification showed higher recovery, survival and fertilization rates than those of conventional EM grid vitrification (100% vs. 95.0%, p = 0.024; 90.0% vs. 78.9%, p = 0.033; 56.7% vs. 38.7%, p = 0.021, respectively). Hatching rate tended to be higher for simplified EM grid vitrification compared to conventional EM grid vitrification (41.1% vs. 24.1%). In conclusion, simplified EM grid vitrification is a convenient and efficient method for cryopreservation of mouse mature oocytes, compared to conventional EM grid vitrification and slow freezing methods.
doi:10.3349/ymj.2006.47.3.399
PMCID: PMC2688161  PMID: 16807991
EM grid vitrification; cryopreservation; mouse oocyte
19.  Production of Chemokines in Kawasaki Disease, Henoch-Schönlein Purpura and Acute Febrile Illness 
Journal of Korean Medical Science  2004;19(6):800-804.
We compared the production of three chemokines; interferon-γ-inducible protein-10 (IP-10), monocyte chemoattractant protein-1 (MCP-1) and growth-related oncogene-α (Gro-α) that attracts monocytes or neutrophils, or both, in peripheral blood at acute stage of Kawasaki disease (n=29), Henoch-Schönlein purpura (n=15) and acute febrile illnesses (n=12). The production of the chemokines was assayed by ELISA. The plasma levels of IP-10 were markedly elevated in Kawasaki disease (538.6±336.4 pg/mL) and acute febrile illnesses (417.1±262.2 pg/mL) compared with in Henoch-Schönlein purpura (58.7±95.7 pg/mL) (p<0.05). The MCP-1 levels were elevated in Kawasaki disease (443.0±473.1 pg/mL) and acute febrile illnesses (328.6±261.1 pg/mL) compared with in Henoch-Schönlein purpura (82.9±79.0 pg/mL) (p<0.05). The Gro-α levels were elevated only in acute febrile illnesses (134.3±153.6 pg/mL) compared with in Kawasaki disease (31.8±22.1 pg/mL) or Henoch-Schönlein purpura (29.4±53.3 pg/mL) (p<0.05). According to these results, monocytes may play an important role in Kawasaki disease. In acute febrile illnesses, both monocytes and neutrophils may play an important role. By contrast, Henoch-Schönlein purpura may not be associated with the role of monocytes and neutrophils. Further studies using a larger number of cases are needed.
doi:10.3346/jkms.2004.19.6.800
PMCID: PMC2816295  PMID: 15608388
Mucocutaneous Lymph Node Syndrome; Kawasaki Disease; Purpura, Schönlein-Henoch; Acute Febrile Illness; Measles; Gastroenteritis; Pneumonia; Tonsillitis; Mumps; Exanthem Subitum; Chemokines, CC; Chemokines, CXC; Chemokines
20.  Production and expression of Gro-alpha and RANTES by peripheral blood mononuclear cells isolated from patients with Kawasaki disease and measles. 
Journal of Korean Medical Science  2003;18(3):381-386.
We investigated whether the production and gene expression of Gro-alpha and RANTES in Kawasaki disease differ in measles. Forty-two samples from 14 patients in different clinical stages of Kawasaki disease, eight samples from 8 patients in the acute stage of measles and seven samples from 7 healthy children were collected. The present study was performed using ELISA and RT-PCR for the productions and gene expression of the chemokines. The production of Gro-alpha was markedly elevated during the acute stage of measles compared with Kawasaki disease. Moreover, the expression of Gro-alpha was increased in every case of measles, but not in Kawasaki disease. The production of RANTES was elevated in the acute stage of both diseases when compared to the healthy control. However, the plasma RANTES level did not change significantly according to the clinical stages of Kawasaki disease. A correlation between the production and gene expression of RANTES and Gro-alpha was not found in Kawasaki disease. These results suggest that Kawasaki disease differs from measles with regard to Gro-alpha production and expression, but not RANTES. Gro-alpha might play an important role in the acute stage of measles, however not in Kawasaki disease. Further studies are needed to clarify the efficacy of Gro-alpha as a marker in measles.
PMCID: PMC3055045  PMID: 12808325
21.  Glial Cell-Specific Regulation of the JC Virus Early Promoter by Histone Deacetylase Inhibitors 
Journal of Virology  2003;77(6):3394-3401.
The human polyomavirus JC virus is the etiologic agent of the fatal disease demyelinating progressive multifocal leukoencephalopathy. Although multiple transcription factors have been shown to interact with the JC virus promoter and regulate transcriptional activity, their relevance to cell specificity remains elusive. To investigate whether chromatin structure controls glial cell-specific expression of JC virus early genes, glial and nonglial cells were transfected with a reporter plasmid containing the JC virus early promoter and then treated with the histone deacetylase (HDAC) inhibitors trichostatin A (TSA) and sodium butyrate. TSA and butyrate induced 20- to 30-fold activation of the JC virus promoter in nonglial cells, whereas less than 2-fold induction was observed in glial cells. These results indicate that the JC virus early promoter might be highly suppressed in nonglial cells by hypoacetylated chromatin and activated by hyperacetylation. In support of this, chromatin immunoprecipitation assays demonstrated acetylation of the JC virus promoter region in U87MG cells but no acetylation in HeLa cells. In addition, treatment of HeLa cells with TSA induced hyperacetylation of the JC virus promoter, whereas minimal induction was seen in U87MG cells. Deletional and site-directed mutational analyses revealed that the enhancer region and Sp1 binding site upstream of the TATA box were important for TSA-mediated activation. We confirmed TSA-mediated activation of the JC virus promoter in the context of natural chromatin structure in stable cell lines. Thus, it appears that chromatin structure may control JC virus transcription in a cell-specific manner.
doi:10.1128/JVI.77.6.3394-3401.2003
PMCID: PMC149517  PMID: 12610114
22.  An 80-Kilodalton Protein That Binds to the Pre-S1 Domain of Hepatitis B Virus 
Journal of Virology  2000;74(1):110-116.
It has been suggested that hepatitis B virus (HBV) binds to a receptor on the plasma membrane of human hepatocytes via the pre-S1 domain of the large envelope protein as an initial step in HBV infection. However, the nature of the receptor remains controversial. In an attempt to identify a cell surface receptor for HBV, purified recombinant fusion protein of the pre-S1 domain of HBV with glutathione S-transferase (GST), expressed in Escherichia coli, was used as a ligand. The surface of human hepatocytes or HepG2 cells was biotinylated, and the cell lysate (precleared lysate) which did not bind to GST and glutathione-Sepharose beads was used as a source of receptor molecules. The precleared lysate of the biotinylated cells was incubated with the GST–pre-S1 fusion protein, and the bound proteins were visualized by Western blotting and enhanced chemiluminescence. An approximately 80-kDa protein (p80) was shown to bind specifically to the pre-S1 domain of the fusion protein. The receptor binding assay using serially or internally deleted segments of pre-S1 showed that amino acid residues 12 to 20 and 82 to 90 are essential for the binding of pre-S1 to p80. p80 also bound specifically to the pre-S1 of native HBV particles. Analysis of the tissue and species specificity of p80 expression in several available human primary cultures and cell lines of different tissue origin showed that p80 expression is not restricted to human hepatocytes. Taken together the results suggest that p80 may be a component of the viral entry machinery.
PMCID: PMC111519  PMID: 10590097
23.  Glial Cell-Specific Regulation of the JC Virus Early Promoter by Large T Antigen 
Journal of Virology  2000;74(2):755-763.
Progressive multifocal leukoencephalopathy (PML) is a fatal demyelinating disease that results from an oligodendrocyte infection caused by JC virus. The JC virus early promoter directs cell-specific expression of the viral replication factor large T antigen, and thus transcriptional regulation constitutes a major mechanism of glial tropism in PML. We have previously demonstrated that T antigen controls the JC virus basal promoter in a glial cell-specific manner, since T antigen repressed the JC virus and simian virus 40 (SV40) early promoters in glioma cells but induced strong activation of the JC virus early promoter in nonglial cells. To further analyze these findings, T antigen and nuclear extracts from glial and nonglial cells were used to examine DNase I footprints on the proximal promoter. T-antigen binding to site II was more extensive than expected based on sequence homology with SV40, and nuclear proteins protected several regions of the proximal promoter in a cell-specific manner. Multiple Sp1 binding domains were identified. Site-directed mutagenesis revealed that T-antigen-mediated activation required a TATA box sequence, a pentanucleotide repeat immediately upstream of the TATA box, and an Sp1 binding site downstream of the TATA box. When footprints were obtained with mutant promoters which blocked T-antigen-induced transactivation, no change in T-antigen binding was observed. These results suggest that T antigen activates the JC virus basal promoter in nonglial cells by interaction with the transcription initiation complex.
PMCID: PMC111595  PMID: 10623737
24.  Protein Kinase C-Dependent Dephosphorylation of Tyrosine Hydroxylase Requires the B56δ Heterotrimeric Form of Protein Phosphatase 2A 
PLoS ONE  2011;6(10):e26292.
Tyrosine hydroxylase, which plays a critical role in regulation of dopamine synthesis, is known to be controlled by phosphorylation at several critical sites. One of these sites, Ser40, is phosphorylated by a number of protein kinases, including protein kinase A. The major protein phosphatase that dephosphorylates Ser40 is protein phosphatase-2A (PP2A). A recent study has also linked protein kinase C to the dephosphorylation of Ser40 [1], but the mechanism is unclear. PP2A isoforms are comprised of catalytic, scaffold, and regulatory subunits, the regulatory B subunits being able to influence cellular localization and substrate selection. In the current study, we find that protein kinase C is able to phosphorylate a key regulatory site in the B56δ subunit leading to activation of PP2A. In turn, activation of the B56δ-containing heterotrimeric form of PP2A is responsible for enhanced dephosphorylation of Ser40 of tyrosine hydroylase in response to stimulation of PKC. In support of this mechanism, down-regulation of B56δ expression in N27 cells using RNAi was found to increase dopamine synthesis. Together these studies reveal molecular details of how protein kinase C is linked to reduced tyrosine hydroxylase activity via control of PP2A, and also add to the complexity of protein kinase/protein phosphatase interactions.
doi:10.1371/journal.pone.0026292
PMCID: PMC3198769  PMID: 22046270

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