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Kang SK, Park YD, Kang SI, Kim DK, Kang KL, Lee SY, Lee HJ, Kim EC. Role of resistin in the inflammatory response induced by nicotine plus lipopolysaccharide in human periodontal ligament cells in vitro. J Periodontal Res 2014; 50:602-13. [PMID: 25393899 DOI: 10.1111/jre.12240] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/12/2014] [Indexed: 01/31/2023]
Abstract
BACKGROUND AND OBJECTIVE Resistin was recently reported to play a role in inflammation-related diseases such as arthritis. However, the precise role of resistin in chronic inflammatory diseases, such as periodontal disease, remains unclear. The aim of this study was to investigate the combined effects of nicotine and lipopolysaccharide (LPS) on the expression of resistin and to assess whether resistin expression influences the levels of inflammatory cytokines, extracellular matrix (ECM) molecules and MMPs in human periodontal ligament cells (PDLCs) stimulated with both nicotine and LPS. MATERIAL AND METHODS PDLCs were pretreated with isoproterenol or resistin-specific small interfering RNA (siRNA), stimulated with LPS plus nicotine for 24 h, and then monitored for the production of inflammatory mediators. The concentrations of prostaglandin E2 (PGE2) and nitric oxide (NO) were measured by radioimmunoassay and the Griess method, respectively. RT-PCR and western blot analysis were used to measure the levels of mRNA and protein, respectively. Western blot analysis was also used to assess the activation of various signal-transduction pathways. RESULTS Treatment with nicotine plus LPS up-regulated the expression of resistin mRNA and the production of resistin protein in PDLCs in a time- and concentration-dependent manner. Isoproterenol-mediated interference with the function of resistin, or siRNA-mediated knockdown of resistin expression, markedly attenuated the LPS plus nicotine-mediated stimulation of PGE2 and NO production, the production of cyclooxygenase-2 (COX-2) and inducible nitric oxide synthase proteins and the expression of proinflammatory cytokines [tumor necrosis factor-α, interleukin (IL)-1β, IL-6 and IL-12] and MMPs (MMP-1, MMP-2 and MMP-9); however, these treatments restored the expression of ECM molecules. Furthermore, pretreatment with isoproterenol or resistin-specific siRNA blocked nicotine plus LPS-induced activation of phosphoinositide-3-kinase, glycogen synthase kinase-3 beta, β-catenin, p38, ERK, JNK and nuclear factor-κB. CONCLUSION This is the first study to show that the inhibition of resistin, by either a pharmacological or a genetic silencing approach, has anti-inflammatory effects. These effects include decreased levels of inflammatory cytokines and the prevention of ECM breakdown in a nicotine plus LPS-stimulated PDLC model.
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Affiliation(s)
- S K Kang
- Department of Oral Medicine, School of Dentistry, Kyung Hee University, Seoul, Korea
| | - Y D Park
- Department of Preventive and Society Dentistry, School of Dentistry, Kyung Hee University, Seoul, Korea
| | - S I Kang
- Department of Oral and Maxillofacial Pathology, Research Center for Tooth and Periodontal Regeneration (MRC), School of Dentistry, Kyung Hee University, Seoul, Korea
| | - D K Kim
- Department of Oral Medicine, School of Dentistry, Kyung Hee University, Seoul, Korea
| | - K L Kang
- Department of Periodontology, School of Dentistry, Kyung Hee University, Seoul, Korea
| | - S Y Lee
- Department of Oral and Maxillofacial Pathology, Research Center for Tooth and Periodontal Regeneration (MRC), School of Dentistry, Kyung Hee University, Seoul, Korea
| | - H J Lee
- Department of Oral and Maxillofacial Pathology, Research Center for Tooth and Periodontal Regeneration (MRC), School of Dentistry, Kyung Hee University, Seoul, Korea
| | - E C Kim
- Department of Oral and Maxillofacial Pathology, Research Center for Tooth and Periodontal Regeneration (MRC), School of Dentistry, Kyung Hee University, Seoul, Korea
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Kumar B, Min K, Bashirzadeh M, Farimani AB, Bae MH, Estrada D, Kim YD, Yasaei P, Park YD, Pop E, Aluru NR, Salehi-Khojin A. The role of external defects in chemical sensing of graphene field-effect transistors. Nano Lett 2013; 13:1962-8. [PMID: 23586702 DOI: 10.1021/nl304734g] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
A fundamental understanding of chemical sensing mechanisms in graphene-based chemical field-effect transistors (chemFETs) is essential for the development of next generation chemical sensors. Here we explore the hidden sensing modalities responsible for tailoring the gas detection ability of pristine graphene sensors by exposing graphene chemFETs to electron donor and acceptor trace gas vapors. We uncover that the sensitivity (in terms of modulation in electrical conductivity) of pristine graphene chemFETs is not necessarily intrinsic to graphene, but rather it is facilitated by external defects in the insulating substrate, which can modulate the electronic properties of graphene. We disclose a mixing effect caused by partial overlap of the highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) of adsorbed gas molecules to explain graphene's ability to detect adsorbed molecules. Our results open a new design space, suggesting that control of external defects in supporting substrates can lead to tunable graphene chemical sensors, which could be developed without compromising the intrinsic electrical and structural properties of graphene.
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Affiliation(s)
- B Kumar
- Department of Mechanical and Industrial Engineering, University of Illinois at Chicago, Chicago, Illinois 60607, USA
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Kim ES, Jeon SW, Park SY, Park YD, Chung YJ, Yoon SJ, Lee SY, Park JY, Bae HI, Cho CM, Tak WY, Kweon YO, Kim SK, Choi YH. Where has the tumor gone? The characteristics of cases of negative pathologic diagnosis after endoscopic mucosal resection. Endoscopy 2009; 41:739-45. [PMID: 19693749 DOI: 10.1055/s-0029-1215043] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/10/2022]
Abstract
BACKGROUND AND STUDY AIMS Discrepancies can occur between the histopathological findings from forceps biopsy and endoscopic mucosal resection (EMR), and occasionally in embarrassing cases tumorous tissue is not found at EMR. The aim of the present study was to evaluate the clinical, endoscopic, and histological features of gastric tumors in patients with pathololgically negative findings at EMR. PATIENTS AND METHODS We retrospectively reviewed data from all patients with gastric tumor treated with EMR or endoscopic submucosal dissection (ESD) between August 1999 and April 2007 at our institution, and enrolled into the study patients with no tumor tissue found at mucosal resection. Their biopsy and EMR specimen slides were reviewed by a single pathologist. Patient characteristics, including demographic and clinical features, and the endoscopic appearance of mucosal lesions were evaluated. RESULTS Out of 633 patients treated with EMR or ESD, 20 patients (3.2 %) were included. The mean +/- SD maximal dimension of the mucosal lesions was 6.40 +/- 2.19 mm (range 3 - 10). Mean number of forceps biopsy fragments was 3.80 +/- 1.96 and mean sampling ratio was 2.08 +/- 1.07 mm/fragment. Before resection, histological findings from forceps biopsy were: 13 low grade dysplasias (65.0 %), 2 high grade dysplasias (10.0 %), and 5 intramucosal carcinomas (25.0 %). CONCLUSIONS In the case of pathologically negative findings at EMR, tumors might have been small enough to have been removed by the previous forceps biopsy. However, the possibility of sampling error or of a different location should be considered. Furthermore, appropriate communication between endoscopists and pathologists is essential.
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Affiliation(s)
- E S Kim
- Department of Internal Medicine, Division of Gastroenterology and Hepatology, Kyungpook National University Hospital, Daegu 700-721, Korea
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Kim JY, Park H, Kwon KH, Park JY, Baek JY, Lee TS, Song HR, Park YD, Lee SH. A cell culturing system that integrates the cell loading function on a single platform and evaluation of the pulsatile pumping effect on cells. Biomed Microdevices 2008; 10:11-20. [PMID: 17624619 DOI: 10.1007/s10544-007-9105-z] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
In this paper, we present a novel microfluidic system with pulsatile cell storing, cell-delivering and cell culturing functions on a single PDMS platform. For this purpose, we have integrated two reservoirs, a pulsatile pumping system containing two soft check valves, which were fabricated by in situ photopolymerization, six switch valves, and three cell culture chambers all developed through a simple and rapid fabrication process. The sample volume delivered per stroke was 120 nl and the transported volume was linearly related to the pumping frequency. We have investigated the effect of the pulsatile pneumatic micropumping on the cells during transport. For this purpose, we pumped two types of cell suspensions, one containing human breast adenocarcinoma cells (MCF-7) and the other mesenchymal stem cells (hMSCs) derived from bone marrow. The effect of pulsatile pumping on both cell types was examined by short and long-term culture experiments. Our results showed that the characteristics of both cells were maintained; they were not damaged by the pumping system. Evaluations were carried out by morphological inspection, viability assay and immunophenotyping analysis. The delivered MCF-7 cells and hMSCs spread and proliferated onto the gelatin coated cell culture chamber. This total micro cell culture system can be applied to cell-based high throughput screening and for co-culture of different cells with different volume.
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Affiliation(s)
- J Y Kim
- Department of Biomedical Engineering, Korea University, Anam-dong, Seongbuk-gu, Seoul 136-701, South Korea
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Park YD, Chung YJ, Chung HY, Yu W, Bae HI, Jeon SW, Cho CM, Tak WY, Kweon YO. Factors related to lymph node metastasis and the feasibility of endoscopic mucosal resection for treating poorly differentiated adenocarcinoma of the stomach. Endoscopy 2008; 40:7-10. [PMID: 18210339 DOI: 10.1055/s-2007-966750] [Citation(s) in RCA: 97] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
BACKGROUND AND AIM Endoscopic mucosal resection (EMR) is currently not accepted as an alternative treatment to surgery in early gastric cancer (EGC) of the undifferentiated histologic type. The present retrospective analysis examined the correlation of various histologic factors with the presence of lymph node metastasis (LNM). PATIENTS AND METHODS A retrospective analysis on 234 patients with poorly differentiated EGC who underwent radical gastrectomy with D2 lymph node dissection was undertaken. Several clinicopathologic factors were investigated to identify predictive factors for LNM: age, sex, type of operation, tumor location, tumor size, gross type, ulceration, lymphatic invasion, and depth of invasion. RESULTS Of the 234 lesions with poorly differentiated EGC, half (n = 116) already showed submucosal invasion in the resection specimen; 25.9 % of those (30/116) were limited to the upper third (SM1). Of the lesions confined to the mucosa, LNM was found in 3.4 % (4/118). With minor submucosal infiltration (SM1), the LNM rate was lower (0/30) in our patient population. Only with SM2/3 infiltration did the LNM rate sharply rise to around 30 %. The cut-off for submucosal infiltration depth was 500 microm (0/32 LNM), above which LNM rates were substantial (31.2 %; 24/77). There was limited correlation between the SM1-3 classification and actual measurement of submucosal infiltration depth. In a multivariate analysis, tumor size ( P = 0.033), depth of invasion ( P = 0.004), and lymphatic invasion ( P < 0.001) were associated with LNM. CONCLUSION Poorly differentiated EGC confined to the mucosa or with minimal submucosal infiltration (<or= 500 microm) could be considered for curative EMR due to the low risk of LNM. Given the limited case number of subgroups, these findings should be confirmed by more data from other centers, which should also focus on local recurrence after EMR in poorly differentiated EGC.
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Affiliation(s)
- Y D Park
- Division of Gastroenterology, Department of Internal Medicine, Kyungpook National University Hospital, Daegu, Korea
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Chang GS, Kurmaev EZ, Finkelstein LD, Choi HK, Lee WO, Park YD, Pedersen TM, Moewes A. Post-annealing effect on the electronic structure of Mn atoms in Ga(₁-x)Mn(x)As probed by resonant inelastic x-ray scattering. J Phys Condens Matter 2007; 19:076215. [PMID: 22251602 DOI: 10.1088/0953-8984/19/7/076215] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
The electronic structure of as-grown and post-annealed Ga(₁-x)Mn(x)As epilayers (x≈0.055) has been investigated using resonant inelastic x-ray scattering. Mn L₂,₃ x-ray emission spectra show that the integral intensity ratio of Mn L₂ to L₃ emission lines increases with annealing temperature and comes close to that of manganese oxide. The oxygen K-emission/absorption spectra of post-annealed Ga₀.₉₄₅Mn₀.₀₅₅As show 1.5-3.0 times higher degree of oxidation on the film surface than that of the as-grown sample. These experimental findings are attributed to the diffusion of Mn impurity atoms from interstitial positions in the GaAs host lattice to the surface where they are passivated by oxygen.
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Affiliation(s)
- G S Chang
- Department of Physics and Engineering Physics, University of Saskatchewan, 116 Science Place, Saskatoon, SK, S7N 5E2, Canada.
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Chun SH, Kim YS, Choi HK, Jeong IT, Lee WO, Suh KS, Oh YS, Kim KH, Khim ZG, Woo JC, Park YD. Interplay between carrier and impurity concentrations in annealed Ga1-xMnxAs: intrinsic anomalous hall effect. Phys Rev Lett 2007; 98:026601. [PMID: 17358627 DOI: 10.1103/physrevlett.98.026601] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/29/2006] [Indexed: 05/14/2023]
Abstract
Investigating the scaling behavior of annealed Ga1-xMnxAs anomalous Hall coefficients, we note a universal crossover regime where the scaling behavior changes from quadratic to linear. Furthermore, measured anomalous Hall conductivities in the quadratic regime when properly scaled by carrier concentration remain constant, spanning nearly a decade in conductivity as well as over 100 K in T_[C] and comparing favorably to theoretically predicated values for the intrinsic origins of the anomalous Hall effect. Both qualitative and quantitative agreements strongly point to the validity of new equations of motion including the Berry phase contributions as well as the tunability of the anomalous Hall effect.
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Affiliation(s)
- S H Chun
- Department of Physics and Institute of Fundamental Physics, Sejong University, Seoul 143-747, Korea
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8
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Park BS, Kim JS, Kim SH, Park YD. Characterization of a pollen-preferential gene, BAN102, from Chinese cabbage. Plant Cell Rep 2005; 24:663-70. [PMID: 16160834 DOI: 10.1007/s00299-005-0007-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/13/2004] [Revised: 04/05/2005] [Accepted: 04/13/2005] [Indexed: 05/04/2023]
Abstract
We isolated and characterized a pollen-preferential gene, BAN102, from Chinese cabbage and analyzed the activity of its promoter. There were three or four copies of the BAN102 gene in the Chinese cabbage genome that specifically expressed in pollen and pollen tube. There were 2137 bp of BAN102 genomic clone comprising 186 bp of protein coding region, and 1178 bp of 5' and 773 bp of 3' non-coding regions. TATA box were located at 1071 nt of the promoter region while the polyadenylation signal and polyadenylation site were at 1470 and 1486 nt of the 3' non-coding region. BLAST search of BAN102 sequence showed that coding region of BAN102 gene was the greatest percent similarity with arabinogalactan protein (AGP23) gene from Arabidopsis thaliana. Promoter analysis using GUS gene as a reporter showed that the pollen-specificity of BAN102 resided within the -112 to -44 bp of proximal promoter from the transient expression in tobacco and Chinese cabbage plants.
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MESH Headings
- Base Sequence
- Blotting, Southern
- Brassica/genetics
- Cloning, Molecular
- DNA, Complementary/genetics
- Gene Dosage/genetics
- Gene Expression Profiling
- Gene Expression Regulation, Plant/genetics
- Gene Transfer Techniques
- Genes, Plant/genetics
- Genes, Reporter
- Genome, Plant
- Molecular Sequence Data
- Organ Specificity
- Plants, Genetically Modified
- Pollen/anatomy & histology
- Pollen/cytology
- Pollen/genetics
- Promoter Regions, Genetic/genetics
- RNA, Messenger/genetics
- RNA, Messenger/metabolism
- Restriction Mapping
- Nicotiana
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Affiliation(s)
- B S Park
- Brassica Genomics Team, National Institute of Agricultural Biotechnology, Rural Development Administration, Suwon 441-701, Korea
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9
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Lee KH, Meador KJ, Park YD, King DW, Murro AM, Pillai JJ, Kaminski RJ. Pathophysiology of altered consciousness during seizures: Subtraction SPECT study. Neurology 2002; 59:841-6. [PMID: 12297563 DOI: 10.1212/wnl.59.6.841] [Citation(s) in RCA: 80] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
BACKGROUND The mechanisms underlying altered consciousness during seizures are poorly understood. Previous clinicopathologic studies suggest a role for the thalamus and upper brainstem in consciousness mechanisms. OBJECTIVE To examine blood flow changes associated with altered consciousness during seizures. METHODS Seventy-one patients with epilepsy who underwent video-EEG monitoring and ictal/interictal SPECT were studied. Patients were divided into three groups depending on their conscious state during seizures: 1) complete impairment of consciousness (CI), 2) no impairment of consciousness (NI), or 3) uncertain impairment of consciousness (UI). The distribution of blood flow changes during these seizures was assessed by subtraction (ictal - interictal) SPECT co-registered to MRI. Conscious state was assessed in relation to secondary ictal hyperperfusion in subcortical regions (i.e., thalamus and upper brainstem). RESULTS Impairment of consciousness showed a strong association with secondary hyperperfusion in the thalamic/upper brainstem region (p = 0.01), occurring in 92% (45/49) of CI, 69% (9/13) of UI, and 11% (1/9) of NI. CONCLUSIONS These findings are consistent with a role for the thalamus and upper brainstem in consciousness mechanisms. The authors suggest that the spread of epileptic discharges or a trans-synaptic activation (diaschisis) of these structures is an important mechanism in the alteration of consciousness during seizures. Variance in the results may be due to differences in timing of radioisotope injection, sensitivity of the subtraction SPECT technique, and the ability to clinically assess the conscious state.
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Affiliation(s)
- K H Lee
- Department of Neurology, Medical College of Georgia, Augusta, GA, USA
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Stroud RM, Hanbicki AT, Park YD, Kioseoglou G, Petukhov AG, Jonker BT, Itskos G, Petrou A. Reduction of spin injection efficiency by interface defect spin scattering in ZnMnSe/AlGaAs-GaAs spin-polarized light-emitting diodes. Phys Rev Lett 2002; 89:166602. [PMID: 12398743 DOI: 10.1103/physrevlett.89.166602] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/24/2001] [Indexed: 05/24/2023]
Abstract
We report the first experimental demonstration that interface microstructure limits diffusive electrical spin-injection efficiency across heteroepitaxial interfaces. An inverse correlation be-tween spin-polarized electron injection efficiency and interface defect density is demonstrated for ZnMnSe/AlGaAs-GaAs spin-polarized light-emitting diodes that exhibit quantum well spin polarizations up to 85%. A theoretical treatment shows that the suppression of spin injection due to interface defects results from the contribution of the defect potential to the spin-orbit interaction, which increases the spin-flip scattering.
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Affiliation(s)
- R M Stroud
- Naval Research Laboratory, Washington, DC 20375, USA
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11
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Park YD, Yang Y, Chen QX, Lin HN, Liu Q, Zhou HM. Kinetics of complexing activation by the magnesium ion on green crab (Scylla serrata) alkaline phosphatase. Biochem Cell Biol 2002; 79:765-72. [PMID: 11800017] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/23/2023] Open
Abstract
As with mammalian enzymes, green crab (Scylla serrata) alkaline phosphatase can be activated by Mg2+ through a time-dependent course. The activation is mainly a Vmax effect. Tsou's method was used to study the kinetic course of activation. The results show that the enzyme was activated by a complexing scheme that had not been previously identified: the enzyme first reversibly and quickly binds Mg2+ and then undergoes a slow reversible course to activation, with a relatively high activation energy (78 +/- 4 kJ/mol) and a slow conformational change. The activation reaction is a single molecule reaction, and the apparent activation rate constant is independent of Mg2+ concentration if the concentration is sufficiently high. The microscopic rate constants of activation and the association constant were determined from the measurements. The proposed scheme may also be applied to the Mg2+ activation mechanism for mammalian enzyme, to explain why the activation rate is time-dependent and not diffusion controlled. Substrate binding was also shown to affect the activation rate constant.
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Affiliation(s)
- Y D Park
- Department of Biological Science and Biotechnology, Tsinghua University, Beijing, People's Republic of China
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12
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Park YD, Ou WB, Yu TW, Zhou HM. Folding pathway for partially folded rabbit muscle creatine kinase. Biochem Cell Biol 2002; 79:479-87. [PMID: 11527217] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/21/2023] Open
Abstract
Rabbit muscle creatine kinase (CK) was modified by 5,5'-dithio-bis(2-nitrobenzoic acid) accompanied by 3 M guanidine hydrochloride denaturation to produce a partially folded state with modified thiol groups. The partially folded CK was in a monomeric state detected by size exclusion chromatography, native-polyacrylamide gel electrophoresis, circular dichroism, and intrinsic fluorescence studies. After dithiothreitol (DTT) treatment, about 70% CK activity was regained with a two-phase kinetic course. Rate constants calculated for regaining of activity and refolding were compared with those for CK modified with various treatments to show that refolding and recovery of activity were synchronized. To further characterize the partially folded CK state and its folding pathway, the molecular chaperone GroEL was used to evaluate whether it can bind with partly folded CK during refolding, and 1-anilinonaphthalene-8-sulfonate was used to detect the hydrophobic surface of the monomeric state of CK. The monomeric state of CK did not bind with GroEL, although it had a larger area of hydrophobic surface relative to the native state. These results may provide different evidence for the structural requirement of GroEL recognition to the substrate protein compared with previously reported results that GroEL bound with substrate proteins mainly through hydrophobic surface. The present study provides data for a monomeric intermediate trapped by the modification of the SH groups during the refolding of CK. Schemes are given for explaining both the partial folding CK pathway and the refolding pathway.
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Affiliation(s)
- Y D Park
- Department of Biological Science and Biotechnology, Tsinghua University, Beijing, China
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13
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Park YD, Hanbicki AT, Erwin SC, Hellberg CS, Sullivan JM, Mattson JE, Ambrose TF, Wilson A, Spanos G, Jonker BT. A group-IV ferromagnetic semiconductor: MnxGe1-x. Science 2002; 295:651-4. [PMID: 11809964 DOI: 10.1126/science.1066348] [Citation(s) in RCA: 1426] [Impact Index Per Article: 64.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
We report on the epitaxial growth of a group-IV ferromagnetic semiconductor, Mn(x)Ge(1-x), in which the Curie temperature is found to increase linearly with manganese (Mn) concentration from 25 to 116 kelvin. The p-type semiconducting character and hole-mediated exchange permit control of ferromagnetic order through application of a +/-0.5-volt gate voltage, a value compatible with present microelectronic technology. Total-energy calculations within density-functional theory show that the magnetically ordered phase arises from a long-range ferromagnetic interaction that dominates a short-range antiferromagnetic interaction. Calculated spin interactions and percolation theory predict transition temperatures larger than measured, consistent with the observed suppression of magnetically active Mn atoms and hole concentration.
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Affiliation(s)
- Y D Park
- Naval Research Laboratory, Washington, DC 20375, USA
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14
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Kim KH, Cho YM, Kang WH, Kim JH, Byun KH, Park YD, Bae KS, Park HM. Negative regulation of filamentous growth and flocculation by Lkh1, a fission yeast LAMMER kinase homolog. Biochem Biophys Res Commun 2001; 289:1237-42. [PMID: 11741326 DOI: 10.1006/bbrc.2001.6128] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
We have isolated a full-length cDNA clone that encodes for a Schizosaccharomyces pombe homolog of the dual-specificity protein kinase of the LAMMER family, lkh1 (lammer kinase homolog). The proposed Lkh1 protein contains 575 amino acids. The lkh1(+) null mutant is viable, but exhibits flocculation upon reaching stationary phase in liquid media and filamentous adhesion growth on solid media. Analysis of the flocculation activity of the lkh1(+) null mutant indicates that asexual aggregation of S. pombe cells into floccules is divalent cation-dependent and galactose-specific. We also demonstrate that the Saccharomyces cerevisiae LAMMER kinase homolog, Kns1, can substitute for the Lkh1 function in S. pombe.
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Affiliation(s)
- K H Kim
- Department of Microbiology, Chungnam National University, Taejon, 305-764, Korea
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15
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Moon YJ, Choe GS, Yun HS, Park YD. Flaring time interval distribution and spatial correlation of major X-ray solar flares. ACTA ACUST UNITED AC 2001. [DOI: 10.1029/2000ja000224] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Abstract
The effects of osmolytes, including dimethysulfoxide, sucrose, glycine and proline, on the unfolding and inactivation of guanidine-denatured creatine kinase were studied by observing the fluorescence emission spectra, the CD spectra and the inactivation of enzymatic activity. The results showed that low concentrations of dimethysulfoxide (< 40%), glycine (< 1.5 m), proline (< 2.5 m) and sucrose (< 1.2 m) reduced the inactivation and unfolding rate constants of creatine kinase, increased the change in transition free energy of inactivation and unfolding (Delta Delta G(u)) and stabilized its active conformation relative to the partially unfolded state with no osmolytes. In the presence of various osmolytes, the inactivation and unfolding dynamics of creatine kinase were related to the protein concentrations. These osmolytes protected creatine kinase against guanidine denaturation in a concentration-dependent manner. The ability of the osmolytes to protect creatine kinase against guanidine denaturation decreased in order from sucrose to glycine to proline. Dimethysulfoxide was considered separately. This study also suggests that osmolytes are not only energy substrates for metabolism and organic components in vivo, but also have an important physiological function for maintaining adequate rates of enzymatic catalysis and for stabilizing the protein secondary and tertiary conformations.
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Affiliation(s)
- W B Ou
- Department of Biological Sciences and Biotechnology, Tsinghua University, Beijing, China
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Ou WB, Luo W, Park YD, Zhou HM. Chaperone-like activity of peptidyl-prolyl cis-trans isomerase during creatine kinase refolding. Protein Sci 2001; 10:2346-53. [PMID: 11604540 PMCID: PMC2374073 DOI: 10.1110/ps.23301] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2001] [Revised: 08/09/2001] [Accepted: 08/09/2001] [Indexed: 10/14/2022]
Abstract
Porcine kidney 18 kD peptidyl-prolyl cis-trans isomerase (PPIase) belongs to the cyclophilin family that is inhibited by the immunosuppressive drug cyclosporin A. The chaperone activity of PPIase was studied using inactive, active, and alkylated PPIase during rabbit muscle creatine kinase (CK) refolding. The results showed that low concentration inactive or active PPIase was able to improve the refolding yields, while high concentration PPIase decreased the CK reactivation yields. Aggregation was inhibited by inactive or active PPIase, and completely suppressed at 32 or 80 times the CK concentration (2.7 microM). However, alkylated PPIase was not able to prevent CK aggregation. In addition, the ability of inactive PPIase to affect CK reactivation and prevent CK aggregation was weaker than that of active PPIase. These results indicate that PPIase interacted with the early folding intermediates of CK, thus preventing their aggregation in a concentration-dependent manner. PPIase exhibited chaperone-like activity during CK refolding. The results also suggest that the isomerase activity of PPIase was independent of the chaperone activity, and that the proper molar ratio was important for the chaperone activity of PPIase. The cysteine residues of PPIase may be a peptide binding site, and may be an essential group for the chaperone function.
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Affiliation(s)
- W B Ou
- Department of Biological Science and Biotechnology, Tsinghua University, Beijing 100084, PR China
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18
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Abstract
Primary oxalosis is a rare congenital disorder of oxalate metabolism characterized by deposits of calcium oxalate in several organs, including the heart. We present the case of a 38-year-old man with primary oxalosis who had unique echocardiographic findings. Two-dimensional echocardiography revealed the sparkling high intensity echocardiographic pattern and concentric thickening of myocardial walls. Microscopic examinations showed the extensive deposits of calcium oxalate crystals in the myocardium. Therefore, we suggest that primary oxalosis should be given important consideration in the differential diagnosis of a hypertrophied myocardium with high intensity echocardiograms.
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Affiliation(s)
- J Yoshioka
- Division of Tracer Kinetics, Osaka University Graduate School of Medicine, D9, 2-2, Yamadaoka, Suita, Osaka 5650871, Japan.
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19
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Yun YP, Do JH, Ko SR, Ryu SY, Kim JH, Song HC, Park YD, Ahn KS, Kim SH. Effects of Korean red ginseng and its mixed prescription on the high molecular weight dextran-induced blood stasis in rats and human platelet aggregation. J Ethnopharmacol 2001; 77:259-264. [PMID: 11535373 DOI: 10.1016/s0378-8741(01)00303-8] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
This study was undertaken to evaluate the antithrombotic effects of Korean Red Ginseng (KRG) and its new prescription (KRGP) consisting of five herbs such as Korean red ginseng, Ganoderma, Cinnamomi Cortex, Glycyrrhizae Radix and Laminaria. In rats with blood stasis induced by high molecular weight dextran, KRG and KRGP significantly restored not only the number of platelets and fibrinogen, but also suppressed the fibrin degradation products (FDP) to normal range. In platelet aggregation assay with human platelet rich plasma (PRP), KRG and KRGP significantly inhibited thrombin and collagen-induced platelet aggregation. The IC(50) values of KRG and KRGP were >2 and 0.23+/-0.01 mg/ml for thrombin, 0.32+/-0.01 and 0.17+/-0.02 mg/ml for collagen and 0.72+/-0.25 and >2 mg/ml for ADP, respectively. In coagulation assay, KRG and KRGP significantly prolonged activated partial prothrombin time (APPT) and prothrombin time (PT) as compared with control data. KRGP was found to be more effective than KRG alone on antithrombotic activity. These results suggest that KRGP may exert its antithrombotic activity due to inhibition of platelet aggregation and coagulation activity more than KRG.
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Affiliation(s)
- Y P Yun
- College of Pharmacy, Chungbuk National University, Cheongju 361-763, South Korea
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20
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Wu BN, Park YD, Tian WX, Zhou HM. Unfolding and inactivation of fatty acid synthase from chicken liver during urea denaturation. Biochim Biophys Acta 2001; 1549:112-21. [PMID: 11566373 DOI: 10.1016/s0167-4838(01)00249-7] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The inactivation and conformational changes of the multifunctional fatty acid synthase (acyl-CoA:malonyl-CoA C-acyltransferase (decarboxylating, oxoacyl- and enoyl-reducing and thioester-hydrolyzing), EC 2.3.1.85) from chicken liver have been studied in urea solution. The results show that complete inactivation of the fatty acid synthase occurs before obvious conformational changes with regard to the overall, beta-ketoacyl reduction and acetoacetyl-CoA reduction reactions. Significant conformational changes indicated by the changes of the intrinsic fluorescence emission and the circular dichroism spectra occurred at higher urea concentrations. The kinetic rate constants for the two phase inactivation and unfolding reactions were measured and semilogarithmic plots of the activity versus time gave curves which could be resolved into two straight lines, indicating that both the inactivation and unfolding processes consisted of fast and slow phases as a first-order reaction. The results from Lineweaver-Burk plots indicated that urea is a competitive inhibitor for acetyl-CoA and malonyl-CoA, with K(m) increasing with increasing urea concentrations. However, urea is a noncompetitive inhibitor for NADPH, the substrate of the overall reaction and beta-ketoacyl reduction reaction, and acetylacetate, the substrate of the beta-ketoacyl reduction reaction. Activation by low concentrations of urea was observed although this activation was only temporarily induced in an early stage of inactivation. The aggregation phenomenon of the fatty acid synthase in a certain concentration range of urea (3-4 M) was also observed during unfolding. This result shows that this multifunctional enzyme unfolds with competition with misfolding in the folding pathway. Comparison of inactivation and conformational changes of the enzyme as well as aggregation imply that unfolding intermediates may exist during urea denaturation. The possible unfolding pathway of fatty acid synthase is also discussed in this paper.
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Affiliation(s)
- B N Wu
- Graduate School, Chinese Academy of Sciences, Beijing, PR China
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21
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Yanagihara I, Inui K, Yanagihara K, Park YD, Tanaka J, Ozono K, Okada S, Kurahashi H. Fluorescence in situ hybridization analysis of peripheral blood cells in Pearson marrow-pancreas syndrome. J Pediatr 2001; 139:452-5. [PMID: 11562629 DOI: 10.1067/mpd.2001.116296] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
We used a dual-color fluorescence in situ hybridization technique to estimate deleted mitochondrial DNA at a single-cell level and determine any correlation with the disease progression in lymphocytes from patients with Pearson marrow-pancreas syndrome. The method demonstrated a shift in heteroplasmy, paralleling the hematologic improvement.
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Affiliation(s)
- I Yanagihara
- Department of Environmental Medicine, Research Institute, Osaka Medical Center for Maternal and Child Health, Izumi City, Osaka, Japan
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22
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Miyagawa S, Hirota S, Park YD, Yamasaki M, Daikoku N, Morikawa H, Yoshioka A, Kitamura Y, Ichijima K. Cutaneous mastocytosis associated with a mixed germ cell tumour of the ovary: report of a case and review of the literature. Br J Dermatol 2001; 145:309-12. [PMID: 11531799 DOI: 10.1046/j.1365-2133.2001.04322.x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
A 10-year-old girl with a mixed germ cell tumour of the ovary, treated by surgery and chemotherapy, developed cutaneous mastocytosis approximately 8 months after starting chemotherapy. This is the sixth report of a germ cell tumour associated with mastocytosis. c-kit receptor point mutations, including Asp816Val and Val560Gly were absent in a biopsy specimen obtained from lesional skin.
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Affiliation(s)
- S Miyagawa
- Department of Dermatology, Nara Medical University, Kashihara City, Nara 634-8522, Japan.
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23
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Hara J, Park YD, Yoshioka A, Yumura-Yagi K, Koudera U, Hosoi G, Sako M, Kosaka Y, Sano K, Misu H, Mabuchi O, Aoyagi N, Yamamoto M, Tawa A, Miyata H, Tanaka H, Kikkawa M, Shimodera M, Kawa-Ha K. Intensification of chemotherapy using block therapies as consolidation and reinduction therapies for acute lymphoblastic leukemia during childhood. Int J Hematol 2001; 74:165-72. [PMID: 11594517 DOI: 10.1007/bf02982000] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
Between April 1994 and March 1997, 143 children (age range, 1-15 years) with newly diagnosed acute lymphoblastic leukemia (ALL), except for those patients with t(9;22), were treated according to protocol-94 of the Osaka Childhood Leukemia Study Group. In this trial, the intensity of chemotherapy was enforced in the consolidation and reinduction phases by introducing AML-type block therapies consisting of concentrated administration of 4 to 6 drugs during 5 or 6 days. For patients in the higher risk groups, rotational combination chemotherapy was introduced following the early phase. A total of 124 children with B-cell precursor ALL (B-pre ALL) were classified into 3 groups, the ultrahigh-risk group (UHRG) (15 patients), the high-risk group (HRG) (61 patients), or the standard-risk group (SRG) (48 patients), based on age. leukocyte count, immunophenotype, central nervous system leukemia, response to treatment, and selected chromosomal abnormalities. The complete remission rate was 93%, and the 6-year event-free survival (EFS) rate was 79%+/-4%. EFS rates for the UHRG, HRG, and SRG groups were 67%+/-12%, 80%+/-6%, and 81%+/-6%, respectively. Nineteen patients with T-cell ALL were treated with the protocol for the UHRG. Thirteen patients (68%) attained complete remission, and the 6-year EFS rate was 55%+/-12%. Thus, intensification of chemotherapy improved the EFS rate and AML-type block therapies appeared to be effective as the consolidation and reinduction therapies for B-pre ALL.
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Affiliation(s)
- J Hara
- Department of Developmental Medicine, Osaka University, Graduate School of Medicine, Suita, Japan.
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24
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Kinoshita S, Yoshioka A, Park YD, Ishizashi H, Konno M, Funato M, Matsui T, Titani K, Yagi H, Matsumoto M, Fujimura Y. Upshaw-Schulman syndrome revisited: a concept of congenital thrombotic thrombocytopenic purpura. Int J Hematol 2001; 74:101-8. [PMID: 11530798 DOI: 10.1007/bf02982558] [Citation(s) in RCA: 98] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
Upshaw-Schulman syndrome (USS) is a congenital bleeding disorder characterized by repeated episodes of thrombocytopenia and microangiopathic hemolytic anemia that respond to infusions of fresh frozen plasma. Inheritance of USS has been thought to be autosomal recessive, because 2 siblings in the same family are often affected but their parents are asymptomatic. Recently, chronic relapsing thrombotic thrombocytopenic purpura (CR-TTP), reported almost exclusively in adults, was shown to be caused by inherited or acquired deficiency in the activity of a plasma von Willebrand factor-cleaving protease (vWF-CPase). The pathogenesis of USS is unknown, and a relationship between CR-YEP and USS has not been reported. We studied 3 unrelated USS patients (ST, SY, and KI) who presented with severe indirect neonatal hyperbilirubinemia. All 3 patients had undetectable vWF-CPase activity, and the inhibitors to vWF-CPase were all negative. In their parents with no clinical symptoms, vWF-CPase activities as a percentage of control samples (mother/father) were 17/20 for ST, 60/45 for SY, and 36/5.6 for KI. Thus, USS and vWF-CPase activity appear to be coinherited as autosomal recessive traits. Transfusion of fresh frozen plasma in 2 patients (ST and SY) resulted in the expected maximal increment of approximately 7% to 8% in vWF-CPase activity at 1 to 4 hours, but the levels became less than 3% within 2 days. After this decrease, platelet counts increased, plateaued in the normal range at 10 to 12 days, and declined thereafter. Thus, the 2 to 3 weeks of therapeutic benefit from plasma infusions will be discussed in relation to the intravascular lifetime of vWF-CPase.
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MESH Headings
- ADAM Proteins
- ADAMTS13 Protein
- Adult
- Anemia, Hemolytic/enzymology
- Anemia, Hemolytic/genetics
- Female
- Genes, Recessive
- Hemorrhagic Disorders/enzymology
- Hemorrhagic Disorders/genetics
- Hemorrhagic Disorders/therapy
- Humans
- Infant, Newborn
- Japan
- Jaundice, Neonatal/etiology
- Jaundice, Neonatal/therapy
- Male
- Metalloendopeptidases/deficiency
- Metalloendopeptidases/genetics
- Pedigree
- Plasma
- Purpura, Thrombotic Thrombocytopenic/classification
- Purpura, Thrombotic Thrombocytopenic/congenital
- Purpura, Thrombotic Thrombocytopenic/enzymology
- Purpura, Thrombotic Thrombocytopenic/genetics
- Syndrome
- Thrombocytopenia/congenital
- Thrombocytopenia/enzymology
- Thrombocytopenia/genetics
- Thrombocytopenia/therapy
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Affiliation(s)
- S Kinoshita
- Department of Pediatrics, Nara Medical University, Kashihara City, Japan
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25
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King DW, Park YD, Smith JR, Wheless JW. Magnetoencephalography in neocortical epilepsy. Adv Neurol 2001; 84:415-23. [PMID: 11091884] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/18/2023]
Affiliation(s)
- D W King
- Department of Neurology, Medical College of Georgia, Augusta 30912, USA
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26
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Abstract
The course of refolding and reactivation of urea-denatured creatine kinase (ATP; creatine N-phosphotransferase, EC 2.7.3.2) has been studied in the absence and presence of molecular chaperonin GroEL. The enzyme was denatured in Tris--HCl buffer containing 6 M urea for 1 h. In the refolding studies, the denatured enzyme was diluted 60-fold into the same buffer containing GroEL or not for activity, turbidity, fluorescence measurements and polyacrylamide gel electrophoresis. The results show that the reactivation process is dependent of creatine kinase concentration in the concentration range 2.5--4 microM. The levels of activity recovery decrease with increasing enzyme concentration because of the formation of wrong aggregates. The molecular chaperonin GroEL can bind the refolding intermediate of creatine kinase and thus prevent the formation of wrong aggregates. This intermediate is an inactive dimeric form that is in a conformation resembling the 'molten globule' state.
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Affiliation(s)
- S Li
- Department of Biological Science and Biotechnology, Tsinghua University, Beijing 10084, People's Republic of China
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27
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Huang K, Park YD, Cao ZF, Zhou HM. Reactivation and refolding of rabbit muscle creatine kinase denatured in 2,2,2-trifluoroethanol solutions. Biochim Biophys Acta 2001; 1545:305-13. [PMID: 11342055 DOI: 10.1016/s0167-4838(00)00293-4] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
The unfolding and refolding of creatine kinase (ATP:creatine N-phosphotransferase (CK), EC 2.7.3.2) during denaturation and reactivation by trifluoroethanol (TFE) have been studied. Significant aggregation was observed when CK was denatured at TFE concentrations between 10% and 40% (v/v). 50% TFE (v/v) was used to study the denaturation and unfolding of CK. The activity loss of CK was a very quick process, as was the marked conformational changes during denaturation followed by fluorescence emission spectra and far-ultraviolet CD spectra. DTNB modification and size exclusion chromatography were used to find that CK dissociated and was in its monomer state after denaturation with 50% TFE. Reactivation and refolding were observed after 80-fold dilution of the denatured CK into 0.05 M Tris-HCl buffer, pH 8.0. The denatured CK recovered about 38% activity following a two phase course (k(1)=4.82+/-0.41x10(-3) s(-1), k(2)=0.60+/-0.01x10(-3) s(-1)). Intrinsic fluorescence maximum intensity changes showed that the refolding process also followed biphasic kinetics (k(1)=4.34+/-0.27x10(-3) s(-1), k(2)=0.76+/-0.02x10(-3) s(-1)) after dilution into the proper solutions. The far-ultraviolet CD spectra ellipticity changes at 222 nm during the refolding process also showed a two phase course (k(1)=4.50+/-0.07x10(-3) s(-1), k(2)=1.13+/-0.05x10(-3) s(-1)). Our results suggest that TFE can be used as a reversible denaturant like urea and GuHCl. The 50% TFE induced CK denaturation state, which was referred to as the 'TFE state', and the partially refolded CK are compared with the molten globule state. The aggregation caused by TFE during denaturation is also discussed in this paper.
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Affiliation(s)
- K Huang
- Department of Biological Science and Technology, Tsinghua University, Beijing, China
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28
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Park YD, Cao ZF, Zhou HM. Reactivation kinetics of guanidine hydrochloride-denatured creatine kinase measured using the substrate reaction. J Protein Chem 2001; 20:67-72. [PMID: 11330350 DOI: 10.1023/a:1011046814606] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Guanidine hydrochloride-denatured creatine kinase (CK) can very quickly form a dimer with reactivity when the denaturant is diluted into the reaction system in the presence of DTT or EDTA. Tsou's method and its applied equation [Tsou (1988), Adv. Enzymol. Rel. Areas Mol. Biol. 61, 381-436; Yang and Zhou (1998), Biochim. Biophys. Acta 1388, 190-198] were used to measure the kinetic reactivation rate constants and the reactivation degree for reassociated CK dimers. Partial reactivation (about 50% at best) occurred following a monophasic course during the substrate reaction when compared with previous time interval measurements. The reactivation degree increased with increasing DTT (0.1-5 mM) and EDTA (0.1-1 mM) concentrations. The apparent forward rate constants do not change with concentration, showing that the reactivation is a reversible first-order reaction, but not of complex formation type. However, the apparent forward rate constants do change with EDTA concentration, showing that the reactivation with EDTA is a reversible first-order reaction as well as of complex formation type. Excess DTT concentrations have an inhibitory effect, indicating that the excessive EDTA acts as a metal chealate not only for free Mg2+, but also for MgATP during the enzyme catalysis. This study shows that additional information about the reactivation of CK can be obtained from examining the substrate reaction. The possible refolding pathway of CK is discussed.
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Affiliation(s)
- Y D Park
- Department of Biological Science and Biotechnology, Tsinghua University, Beijing, China
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29
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Abstract
Atypical features in benign epilepsy of childhood with centrotemporal spikes (BECTS) are not uncommon. There are children with BECTS who do not have a benign outcome in terms of neuropsychologic functioning. BECTS have been linked with Landau-Kleffner syndrome (LKS) and continuous spikes and waves during slow sleep (CSWS). At the Medical College of Georgia from January 1988 to June 1999, 78 children, ages 2-16 years, were identified to have electroencephalogram evidence of centrotemporal spikes. Their medical records were reviewed for developmental history, behavioral problems, and school performance. Children with structural lesions/other epileptic syndromes were excluded. Fifty-six demonstrated a history of clinical seizures compatible with BECTS and 22 demonstrated centrotemporal spikes without clinical seizures. Among all children with centrotemporal spikes, 9% (n = 7) were diagnosed with mild intellectual disability (intelligence quotient < 70), 10% (n = 8) with borderline functioning, 31% (n = 24) with behavioral problems, and 17% (n = 13) with specific learning disabilities. Three children with BECTS experienced language delay and regression. Seizure control for BECTS usually is achieved without much difficulty, with excellent long-term prognosis. However, the data presented indicate that a large number of BECTS patients exhibit learning or behavior problems that require intervention. A small number may demonstrate language outcome similar to children with LKS and CSWS.
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Affiliation(s)
- A W Yung
- Department of Neurology, Section of Child Neurology, Medical College of Georgia, Augusta, Georgia 30912, USA
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30
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Abstract
We performed magnetic resonance spectroscopy in three pediatric patients (two boys and one girl, ages 11 to 17 years) with epilepsia partialis continua. Single-voxel proton magnetic resonance spectroscopy was performed on each patient. Data were acquired from voxels of 4 or 8 cm3 from the affected hemisphere and from contralateral homologous regions. The spectral peaks of several metabolites (N-acetyl-aspartate, choline, creatine, and lactate) were measured. Neuropathologic findings revealed Rasmussen's syndrome in two children and gliosis in one. We observed increased lactate-to-creatine ratios and reduced N-acetyl-aspartate-to-creatine ratios in the affected hemispheres in all three children with epilepsia partialis continua. These data support previous reports. The largest increase in the lactate-to-creatine ratio was detected in a patient with Rasmussen's syndrome and ongoing epilepsia partialis continua at the time of measurement. The other two patients had an increase in the lactate-to-creatine ratio and a decrease in the N-acetyl-aspartate-to-creatine ratio in the affected area. The increased lactate-to-creatine ratio was associated with recurrent focal seizures from different underlying pathologies.
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Affiliation(s)
- Y D Park
- Department of Neurology, Medical College of Georgia, Augusta 30912, USA.
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31
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Lee KH, Park YD, King DW, Meador KJ, Loring DW, Murro AM, Smith JW. Prognostic implication of contralateral secondary electrographic seizures in temporal lobe epilepsy. Epilepsia 2000; 41:1444-9. [PMID: 11077458 DOI: 10.1111/j.1528-1157.2000.tb00120.x] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
PURPOSE Interhemispheric propagation of seizures in temporal lobe epilepsy is frequently noted during intracranial EEG monitoring. We hypothesized that a distinct secondary electrographic seizure (DSES) in the temporal lobe contralateral to primary seizure onset may be an unfavorable prognostic indicator. METHODS We reviewed intracranial depth electrode EEG recordings, 1-year outcome, and medical records of 51 patients (M 29, F 22: age 15-64 years) who underwent anterior temporal lobectomy during 1988-96. We defined DSES as a seizure that spread to the contralateral temporal lobe and produced distinct contralateral EEG features. The distinct feature was focal involvement of one or two electrode contacts at onset, which starts and evolves independently from the ipsilateral temporal lobe. We considered DSES as the predominant seizure pattern when it occurred in more than one half of the patients' recorded seizures. RESULTS Only nine of 19 (47%) patients with predominant DSES had a 1-year seizure-free outcome, whereas 27 of 32 (84%) patients without predominant DSES had a 1-year seizure-free outcome (p < 0.01). Bitemporal independent seizures were more common in patients with predominant DSES (9/19 versus 0/32; p < 0.001). CONCLUSION Our results suggest that distinct contralateral secondary electrographic seizure is a predictor of unfavorable outcome and is also more likely to be associated with bitemporal seizures.
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Affiliation(s)
- K H Lee
- Department of Neurology, Department of Neurosurgery, Medical College of Georgia, Augusta, GA 30912, USA
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32
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Abstract
Five furanocoumarins including a new one were isolated from the root of Angelica dahurica by repeated silica gel column chromatography. Their chemical structures were determined to be isoimperatorin (1), oxypeucedanin hydrate-3"-butyl ether (2), imperatorin (3), knidilin (4), and oxypeucedanin hydrate (5). This represents the first study in which the compound 2 has been isolated and identified. The long-range coupling (5J) in the 1H-NMR spectrum observed in the linear furanocoumarin skeleton was also investigated in detail.
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Affiliation(s)
- N I Baek
- Department of Life Sciences and Institute of Life Sciences, Kyunghee University, Suwon, Korea.
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33
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Smith JR, Lee MR, Jenkins PD, King DW, Murro AM, Park YD, Lee GP, Meador KJ, Loring DW. A 13-year experience with epilepsy surgery. Stereotact Funct Neurosurg 2000; 73:98-103. [PMID: 10853110 DOI: 10.1159/000029763] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Between 1985 and 1997, 563 therapeutic craniotomies were performed: 311 anterior temporal (ATL) and 158 extramesial temporal (XMT) resections, 67 callosotomies, 20 hemispherectomies and 7 multiple subpial transections. Sixty-seven percent of nonlesional ATL cases were seizure free (SF), and 76% of nonlesional ATL cases < or =18 years old were SF. Seventy-eight percent of lesional ATL cases with complete resection were SF. Seventy-three percent of lesional cases < or =18 were SF. Thirty-seven percent of nonlesional XMT cases were SF. Seventy percent of XMT lesional cases with complete resection were SF, and 82% of lesional XMT cases < or =18 were SF. Of the anterior callosotomy cases, there was a > or =90% decrease in generalized tonic-clonic seizures in 50% of patients, and in tonic seizures, drop attacks, absence and myoclonic seizures in approximately 60-70% of patients. Of 20 hemispherectomies, 65% were SF. Of 7 multiple subpial transections, 29% were SF.
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Affiliation(s)
- J R Smith
- Section of Neurosurgery, Medical College of Georgia, Augusta 30912, USA.
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34
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Abstract
Intracranial hemorrhage occurs in 2-8% of patients with hemophilia and can result in neurologic sequelae including seizure disorders. There is a paucity of data concerning the surgical treatment of epilepsy in children with hemophilia. We review our experience with 2 children who developed medically refractory seizure disorders. Both children underwent hemispherotomy, at 18 months (case 1) and 13 years of age (case 2), respectively. Perioperative management included continuous factor replacement. Both children tolerated surgical intervention without complications or increased neurologic deficit. Case 2 showed a 90% reduction in seizure frequency, and case 1 is seizure free. Surgical management of intractable epilepsy in children with hemophilia is safe and effective.
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Affiliation(s)
- D J Yeh
- Departments of Surgery, Children's Medical Center, Medical College of Georgia, Augusta 30912, USA.
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35
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Abstract
Creatine kinase (ATP:creatine N-phosphotransferase, EC 2.7.3.2) is a good model for studying dissociation and reassociation during unfolding and refolding. This study compares self-reassociated CK dimers and CK dimers that contain hybrid dimers under proper conditions. Creatine kinase forms a monomer when denatured in 6 M urea for 1 h which will very quickly form a dimer when the denaturant is diluted under suitable conditions. After modification by DTNB, CK was denatured in 6 M urea to form a modified CK monomer. Dimerization of this modified subunit of CK occurred upon dilution into a suitable buffer containing DTT. Therefore, three different types of reassociated CK dimers including a hybrid dimer can be made from two different CK monomers in the proper conditions. The CK monomers are from a urea-denatured monomer of DTNB-modified CK and from an unmodified urea dissociated monomer. Equal enzyme concentration ratios of these two monomers were mixed in the presence of urea, then diluted into the proper buffer to form the three types of reassociated CK dimers including the hybrid dimer. Reassociated CK dimers including all three different types recover about 75% activity following a two-phase course (k1 = 4.88 x 10(-3) s(-1), k2 = 0.68 x 10(-3) s(-1)). Intrinsic fluorescence spectra of the three different CK monomers which were dissociated in 6 M urea, dissociated in 6 M urea after DTNB modification, and a mixture of the first two dissociated enzymes were studied in the presence of the denaturant urea. The three monomers had different fluorescence intensities and emission maxima. The intrinsic fluorescence maximum intensity changes of the reassociated CK dimers were also studied. The refolding processes also follow biphasic kinetics (k1 = 3.28 x 10(-)3 s(-1), k2 = 0.11 x 10(-3) S(-1)) after dilution in the proper solutions. Tsou's method [Tsou (1988), Adv. Enzymol. Rel. Areas Mol. Biol. 61, 381-436] was also used to measure the kinetic reactivation rate constants for the different three types of reassociated CK dimers, with different kinetic reactivation rate constants observed for each type. CK dissociation and reassociation schemes are suggested based on the results.
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Affiliation(s)
- Y D Park
- Department of Biological Science and Biotechnology, Tsinghua University, Beijing, China
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36
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Abstract
Creatine kinase (ATP: creatine N-phosphotransferase, EC 2.7.3.2) was completely denatured using 3 M guanidine hydrochloride for 2 h as in previous studies [Yao et al. (1982), Sci. Sin. 25B, 1296-1302; Yao et al. (1984), Biochemistry 23, 2740-2744; Yao et al. (1982), Sci. Sin. 25B, 1186-1193]. Under suitable conditions, about 60-70% of the activity can be recovered in the presence of different Mg2+ concentrations. Both the reactivation and the refolding processes follow two-phase courses after dilution in the proper solutions. A comparison of the rate constants for the refolding of unfolded creatine kinase with those for the recovery of its catalytic activity at various Mg2+ concentrations shows that these are not synchronized. The reactivity of guanidine hydrochloride-denatured creatine kinase can be inhibited by Mg2+; however, the rates of reactivation are independent of the Mg2+ concentration. In addition, Mg2+ affects the fluorescence intensity, but the rate constants of refolding are independent of Mg2+ concentration. Although the reactivation of GdHCl-denatured creatine kinase is complete about 3 h after dilution with reactivation solutions, the conformational changes during refolding occur in a much slower reaction. Mg2+ can induce complex changes in the relative fluorescence intensity during refolding over a broad range of concentrations.
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Affiliation(s)
- Y D Park
- Department of Biological Science and Biotechnology, Tsinghua University, Beijing, China
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Zhu CM, Chen QX, Lin HN, Yang Y, Park YD, Zhang RQ, Zhou HM. Kinetics of inhibition of green crab (Scylla serrata) alkaline phosphatase by L-cysteine. J Protein Chem 1999; 18:603-7. [PMID: 10524778 DOI: 10.1023/a:1020611602818] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
The inhibition of alkaline phosphatase from green crab (Scylla serrata) by L-cysteine has been studied. The results show that L-cysteine gives a mixed-type inhibition. The progress-of-substrate-reaction method previously described by Tsou [(1988), Adv. Enzymol. Related Areas Mol. Biol. 61, 391-436] was used to study the inactivation kinetics of the enzyme by L-cysteine. The microscopic rate constants were determined for reaction of the inhibitor with the free enzyme and the enzyme-substrate complex (ES) The results show that inactivation of the enzyme by L-cysteine is a slow, reversible reaction. Comparison of the inactivation rate constants of free enzyme and ES suggests that the presence of the substrate offers marked protection of this enzyme against inactivation by L-cysteine.
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Affiliation(s)
- C M Zhu
- Department of Biological Science and Biotechnology, Tsinghua University, Beijing, China
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Wheless JW, Willmore LJ, Breier JI, Kataki M, Smith JR, King DW, Meador KJ, Park YD, Loring DW, Clifton GL, Baumgartner J, Thomas AB, Constantinou JE, Papanicolaou AC. A comparison of magnetoencephalography, MRI, and V-EEG in patients evaluated for epilepsy surgery. Epilepsia 1999; 40:931-41. [PMID: 10403217 DOI: 10.1111/j.1528-1157.1999.tb00800.x] [Citation(s) in RCA: 154] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
PURPOSE To determine the efficacy and relative contribution of several diagnostic methods [ictal and interictal scalp and intracranial EEG, magnetic resonance imaging (MRI), and magnetoencephalography (MEG)] in identifying the epileptogenic zone for resection. METHODS This was a prospective study using a masked comparison-to-criterion standard. Fifty-eight consecutive patients with refractory partial epilepsy from two university comprehensive epilepsy programs were studied. Patients who were evaluated for and underwent epilepsy surgery were recruited. The main outcome measure was the efficacy of each diagnostic method to identify the resected epileptogenic zone, when referenced to surgical outcome. RESULTS MEG (52%) was second only to ictal intracranial V-EEG in predicting the epileptogenic zone for the entire group of patients who had an excellent surgical outcome (seizure free or rare seizure). In a subanalysis, for patients who had temporal lobe surgery, this same relation was seen (MEG, 57%, ictal intracranial V-EEG, 62%). With extratemporal resection, ictal (81%) and interictal (75%) intracranial EEG were superior to MEG (44%) in predicting the surgery site in those patients with an excellent outcome. Finally, for all patients who had a good surgical outcome, MEG (52%) was better than ictal (33%) or interictal (45%) scalp VEEG in predicting the site of surgery. CONCLUSIONS These results indicate that MEG is a very promising diagnostic method and raise the possibility that it may obviate the need for invasive EEG in some cases or reduce the length of scalp EEG evaluation in others.
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Affiliation(s)
- J W Wheless
- University of Texas-Houston, Texas Comprehensive Epilepsy Program, 77030, USA
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Yang Y, Park YD, Yu TW, Zhou HM. Reactivation and refolding of a partially folded creatine kinase modified by 5,5'-dithio-bis(2-nitrobenzoic acid). Biochem Biophys Res Commun 1999; 259:450-4. [PMID: 10362528 DOI: 10.1006/bbrc.1999.0622] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Creatine kinase with its thiol groups modified by 5, 5'-dithio-bis(2-nitrobenzoic acid) has been shown to be partially folded in a monomeric state using fluorescence, circular dichroism, proteolysis, and size exclusion chromatography studies. In the presence of DTT, the partially folded modified creatine kinase can be reactivated and refolded following a biphasic course, suggesting the existence of a monomeric intermediate during the refolding of CK. The results provide evidence for our previously suggested model of the refolding pathway of urea-denatured creatine kinase.
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Affiliation(s)
- Y Yang
- Department of Biological Science and Biotechnology, School of Life Science and Engineering, Beijing, 100084, China
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40
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Park YD, Yanagihara I, Saitoh S, Momoi MY, Yoshioka A. [Hematologic improvement of Pearson's syndrome confirmed by mitochondrial DNA analysis]. Rinsho Ketsueki 1999; 40:390-5. [PMID: 10390887] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 04/13/2023]
Abstract
We report on an 8-month-old girl with Pearson's syndrome who presented with transfusion-dependent pancytopenia, exocrine pancreatic dysfunction, and lactic acidosis. Bone marrow findings were consistent with sideroblastic anemia and marked vacuolization of myeloid and erythroid precursors. Southern blot analysis of mitochondrial DNA (mtDNA) revealed a 4.5 kb deletion in peripheral blood cells. Gradual hematologic improvement was observed thereafter, and the patient was relieved of the need for blood transfusions. We were able to confirm a decrease of the mtDNA deletion in lymphocytes as well as in lymphoblastoid cell lines cultured from peripheral lymphocytes as the patient made steady hematologic progress.
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Affiliation(s)
- Y D Park
- Department of Pediatrics, Nara Medical University
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Abstract
BACKGROUND Previous studies suggest that responsiveness is impaired during complex partial seizures (CPS) and pseudoseizures (PS); however, to our knowledge, there has been no systematic comparison using both response and memory testing. OBJECTIVE To compare CPS with PS using ictal cognitive assessment (ICA) of responsiveness and memory. PATIENTS AND METHODS We used a nonautomated method of ICA by bedside observers, consisting of family members and staff, during video electroencephalographic monitoring to test responsiveness and memory during the ictal phase in 245 events. We assessed the adequacy of testing and compared the testing results in 31 patients during CPS and 13 patients during PS. RESULTS The ictal presentation of a command was successful in 58% of the events. The ictal presentation of at least 2 memory items with testing for recall after orientation was adequate in 57% of events. Impaired responsiveness was shown during both CPS and PS. However, some response was detected during 48% of PS compared with 18% of CPS (P<.01). Memory items were recalled during 63% of PS but during only 4% of CPS (P<.001). The International Classification of Epileptic Seizures remained useful, but in 11 events (8%), distinguishing complex from simple partial seizures was difficult. Recall of various types of stimuli (aural-verbal vs visual-pictorial) during ICA did not correlate with the side or location of the seizure focus, but this may have been confounded by the rarity of any memory recall during CPS. CONCLUSIONS Ictal cognitive assessment by bedside observers is practical and provides the interaction necessary for properly classifying seizures; ICA, especially memory, may help to distinguish CPS from PS.
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Affiliation(s)
- W L Bell
- Department of Neurology, Wake Forest University School of Medicine, Winston-Salem, NC 27157, USA
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Park JH, Lee WI, Yoon WH, Park YD, Lee JS, Lee MG. Pharmacokinetic and pharmacodynamic changes of furosemide after intravenous and oral administration to rats with alloxan-induced diabetes mellitus. Biopharm Drug Dispos 1998; 19:357-64. [PMID: 9737816 DOI: 10.1002/(sici)1099-081x(199809)19:6<357::aid-bdd114>3.0.co;2-g] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Because some physiological changes occurring in diabetes mellitus patients could alter the pharmacokinetics and pharmacodynamics of the drugs to treat the disease, the pharmacokinetics and pharmacodynamics of furosemide were investigated after intravenous (i.v.) and oral administration of the drug (6 mg per whole body weight) to control rats and alloxan-induced diabetes mellitus rats (AIDRs). After i.v. administration, the total body clearance (5.47 versus 7.05 mL min(-1) kg(-1)) was significantly slower in AIDRs and this was due to significantly slower renal clearance (2.35 versus 4.33 mL min(-1) kg(-1)) because the nonrenal clearance was comparable between two groups of rats. The 8 h urinary excretion of furosemide after i.v. administration decreased significantly (2280 versus 3760 microg) in AIDRs due to impaired kidney function; the glomerular filtration rate measured by creatinine clearance was significantly slower (2.86 versus 4.33 mL min(-1) kg(-1)) and both the plasma urea nitrogen (43.5 versus 17.3 mg dL(-1)) and kidney weight (0.953 versus 0.749% of body weight) increased significantly in AIDRs. This resulted in a significant decrease in the 8 h urine output per g kidney (17.8 versus 43.6 mL) in AIDRs. However, the 8 h diuretic efficiency was not significantly different between two groups of rats. After oral administration, the area under the plasma concentration-time curve from time 0 to 8 h decreased significantly in AIDRs (1200 versus 1910 microg x min mL(-1)) due to considerably decreased absorption of furosemide from gastrointestinal tract of AIDRs. After oral administration, the 8 h urine output per g kidney (18.6 versus 36.4 mL) also decreased significantly in the AIDRs due to significantly decreased 8 h urinary excretion of furosemide (405 versus 2210 microg), however, the 8 h diuretic efficiency increased significantly (127 versus 35.2 mL mg(-1)) in AIDRs.
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Affiliation(s)
- J H Park
- College of Pharmacy, Seoul National University, Republic of Korea
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Smith JR, Lee MR, King DW, Murro AM, Park YD, Lee GP, Loring DW, Meador KJ, Harp R. Results of lesional vs. nonlesional frontal lobe epilepsy surgery. Stereotact Funct Neurosurg 1998; 69:202-9. [PMID: 9711755 DOI: 10.1159/000099875] [Citation(s) in RCA: 45] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Fifty-three seizure focus resections limited to the frontal lobe were performed. Forty-nine had adequate follow-up. Five of 17 (29%) nonlesional (NL) cases and 21 of 32 (66%) lesional (L) cases were seizure free (SF) at 1 year postoperatively. Eight of 9 (89%) L cases < or = 18 years old vs. 13 of 23 (57%) > 18 years old were SF. Eight of 10 (80%) tumor vs. 13 of 22 (59%) nontumor L cases were SF. Sixteen NL cases were localized by invasive recording. Five (31%) were SF. Ictal localization was obtained in 4 of 32 L cases. Three of 4 (75%) were SF. Eighteen of 24 (64%) L cases without ictal localization were SF. Nine of 12 (75%) lateral resections, 7 of 12 (58%) lobectomies, and 2 of 13 (15%) mesial resections were SF. Three of 20 cases with at least 90% reduction in seizures became SD > or = 2 years postresection. No case with < 90% seizure reduction at one year showed improvement with longer follow-up.
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Affiliation(s)
- J R Smith
- Section of Neurosurgery, Medical College of Georgia, Augusta, USA.
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Uk Kim H, Seok Park B, Park YD, Jin YM. Pollen ablation of transgenic tobacco plants by expression of the diphtheria toxin A-chain gene under the control of a putative pectin esterase promoter from Chinese cabbage. Mol Cells 1998; 8:310-7. [PMID: 9666468] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
Abstract
We previously showed that a 383 bp (-274 to approximately +109) promoter of a pollen-specific gene, GBAN215-6, had a property of a late gene in pollen development in transgenic tobacco plants. It drove GUS gene expression from uninucleate microspores to pollen tube growth of trinucleated cells. To more precisely characterize the specificity of the promoter, we placed the diphtheria toxin A-chain (DTx-A) coding region under the control of the GBAN215-6 promoter. Transgenic tobacco plants containing the GBAN215-6/DTx-1 were phenotypically normal until an early stage of flowering. The dehisced anthers do not contain pollen grains and the filament length of stamen was shorter than that of normal plants. Microscopic examination showed that ablation of pollen by the expression of DTx-A was variable. The transgenic tobacco plants containing one copy of the DTx-A gene show 50% aborted and 50% normal pollen, which suggests that this gene acts gametophytically. However, most of the transgenic plants with high copy number were male-sterile. When these male-sterile tobacco plants were backcrossed as female with pollen from wild-type tobacco plants, the fruit capsule sizes and seed yields of the next generation (BC1 lines) were severely reduced and the segregation of male-sterile to fertile plants in BC1 seeds was not Mendelian.
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Affiliation(s)
- H Uk Kim
- Cytogenetics Division, National Institute of Agricultural Science and Technology, Suwon, Korea.
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Yasui M, Park YD, Okamura T, Chayama K, Yoshimoto T, Inoue M, Yagi K, Kawa K. CD34+ progenitor cell transplantation from two HLA-mismatched healthy fathers to two infants with severe aplastic anemia. Int J Hematol 1998; 67:15-22. [PMID: 9594440 DOI: 10.1016/s0925-5710(97)00088-1] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Pluripotent stem cells of hematopoiesis are included among CD34+ cells in the blood and bone marrow. After granulocyte-colony stimulating factor (G-CSF) mobilization, 1-2% of the mononuclear cells in the blood are CD34+ cells, which can be obtained by leukapheresis. We performed CD34+ progenitor cell transplantation in two children with severe aplastic anemia (SAA) who lacked HLA-matched donors. The donors were treated with G-CSF, 600 micrograms/body/day subcutaneously, for 4-5 days. CD34+ cell selection was performed from the apheresis concentrate with mouse anti-CD34 antibody 9C5 and magnet beads coated with sheep anti-mouse IgG1. After the transplantation, the patients received tacrolimus to prevent graft-versus-host disease (GVHD). G-CSF was given to both patients. A mean number of 4.96 x 10(6) CD34+ cells per kilogram of body weight were transplanted. The hematopoietic recovery after the CD34+ cell transplantation was rapid, except for platelets, and acute GVHD was less than or equal to grade I. Case 1, who demonstrated mixed chimerism, anemia and thrombocytopenia after the graft, received a second transplant with intensified preconditioning, and now sustains complete and stable hematopoiesis after a follow-up of 314 days posttransplant. Although Case 2 showed early rejection and received a second transplant, sustained engraftment was never achieved. However, the patient's own hematopoiesis appeared. For SAA patients who do not have HLA-matched donors, this type of approach seems to be a feasible and useful method. However, an intensified preconditioning regimen to overcome the high likelihood of rejection should be employed.
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Affiliation(s)
- M Yasui
- Department of Pediatrics, Osaka Medical Center, Japan
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Park YD, Yasui M, Yoshimoto T, Chayama K, Shimono T, Okamura T, Inoue M, Yumura-Yagi K, Kawa-Ha K. Changes in hemostatic parameters in hepatic veno-occlusive disease following bone marrow transplantation. Bone Marrow Transplant 1997; 19:915-20. [PMID: 9156266 DOI: 10.1038/sj.bmt.1700760] [Citation(s) in RCA: 44] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Hepatic veno-occlusive disease (VOD) is a major complication after bone marrow transplantation (BMT). Its prediction, diagnosis and treatment remain unclear. Examination was made of changes in hemostatic parameters in patients with or without VOD after BMT. Twenty-seven children were studied following BMT. Eight of them developed VOD. Tissue plasminogen activator (t-PA), plasminogen activator inhibitor 1 (PAI-1), thrombomodulin (TM), von Willebrand factor (vWF), factor VII, fibrinogen (FBG), FDP, D-dimer (D-D), plasminogen (PLG), thrombin-antithrombin III (TAT), alpha 2-plasmin inhibitor/plasmin complex (PIC), antithrombin III (AT-III), protein C, N-terminal propeptide for type III procollagen (P-III-P), were measured weekly from pre-BMT to day 28 after BMT. In VOD patients, t-PA and PAI-1 significantly increased (P < 0.05) and FBG significantly fell during the post-transplant period (P < 0.05). Significantly low AT-III and PLG were also noted before VOD (P < 0.05). There were no changes in other hemostatic parameters. t-PA, PAI-1 and FBG would thus appear useful markers for the diagnosis of VOD, and AT-III and PLG, predictive markers for VOD. The coagulation-fibrinolysis system following endothelial cell damage may contribute to the onset of VOD.
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Affiliation(s)
- Y D Park
- Department of Pediatrics, Osaka Medical Center, Japan
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Abstract
We compared Wada memory performance for stimuli presented at two timing intervals following amobarbital injection in 47 non-lesional patients with complex partial seizures (L = 26; R = 21). A significant interaction between seizure focus and timing of presentation was present (P < 0.03). Memory performance for objects whose presentation began approximately 50-55 s following amobarbital administration differed as a function of ipsilateral vs. contralateral injection at a very high level of statistical significance (P < 0.00001). Items presented approximately 4 min, 30 s post injection were also related to seizure onset literality, but at a lower statistical level (P < 0.01). Presentation of Wada memory stimuli earlier during hemispheric anaesthesia yields results that are more sensitive to lateralized temporal lobe seizure onset than does presentation of items later during the procedure.
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Affiliation(s)
- D W Loring
- Department of Neurology, Medical College of Georgia, Augusta 30912-3275, USA
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Okamura T, Park YD, Inoue M, Yasui M, Ueno M, Endo C, Yagi K, Kawa K. [The clinical significance of minimal residual disease of acute leukemia with t(4;11) (q21;q23)]. Rinsho Ketsueki 1996; 37:1318-1321. [PMID: 8960669] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
Hybrid fusion genes are specific tumor markers of several leukemic subtypes. The use of reverse transcription-polymerase chain reaction (RT-PCR) to amplify chimeric cDNAs allows sensitive detection of the leukemia clone. The clinical relevance of minimal residual disease (MRD) remains controversial. In this report, an infantile acute lymphoblastic leukemia with t(4;11) (q21; q23) was analyzed after each treatment for the presence of MRD by RT-PCR amplification of the MLL/LTG4 fusion gene which became available recently. The patient soon achieved a hematological CR, after induction therapy, and underwent autologous BMT following consolidation chemotherapy for 9 months. However, he relapsed three months after the BMT. MRD was always detectable during his clinical course. These findings suggest that the detection of MRD of the MLL/LTG4 fusion transcript is a useful tool for monitoring MRD and selecting treatment.
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Park YD, Murro AM, King DW, Gallagher BB, Smith JR, Yaghmai F. The significance of ictal depth EEG patterns in patients with temporal lobe epilepsy. Electroencephalogr Clin Neurophysiol 1996; 99:412-5. [PMID: 9020799 DOI: 10.1016/s0013-4694(96)95120-2] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
We reviewed 187 depth recorded seizures in 33 patients with non-lesional temporal lobe complex partial seizures. All patients had a minimum of 1 year follow-up following temporal lobectomy. We classified seizure onset pattern as rhythmic activity, attenuation, or repetitive spikes or spike wave complexes. The most common pattern of seizure onset was rhythmic activity and the next most common pattern was repetitive spikes. Seventy-five seizures (49%) had only one seizure onset pattern, and 79 seizures (51%) had a combination of seizure onset patterns. The degree of hippocampal gliosis strongly predicted the type of seizure onset pattern (Chi square = 24.07, 2 d.f., P < 0.01). The rhythmic activity pattern was associated with mild gliosis, and the repetitive spike pattern was associated with severe gliosis. We classified seizure onset as focal or regional based on the number of electrode contacts that were involved by the ictal EEG. A focal seizure onset was associated with an excellent outcome following temporal lobectomy.
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Affiliation(s)
- Y D Park
- Department of Neurology, Medical College of Georgia, Augusta 30912-3255, USA
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50
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Papp I, Iglesias VA, Moscone EA, Michalowski S, Spiker S, Park YD, Matzke MA, Matzke AJ. Structural instability of a transgene locus in tobacco is associated with aneuploidy. Plant J 1996; 10:469-78. [PMID: 8811861 DOI: 10.1046/j.1365-313x.1996.10030469.x] [Citation(s) in RCA: 25] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
This paper describes molecular and cytogenetic evidence for the stability of a transgene locus that is present on the triplicated chromosome in an aneuploid tobacco line. This instability was manifested in several ways in trisomics including a major chromosome rearrangement that was detectable cytogenetically, smaller scale DNA rearrangements that occurred both germinally and somatically, and methylation/epigenetic silencing. In a deletion derivative of the locus, DNA breakpoints were found in AT-rich regions. One of these regions binds to nuclear scaffolds in vitro, suggesting a possible role for aberrant topoisomerase II cleavage in destabilization of the locus. The implications of increased chromosome instability in aneuploids for plant karyotype evolution and human carcinogenesis are discussed.
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Affiliation(s)
- I Papp
- Institute of Molecular Biology, Austrian Academy of Sciences, Salzburg, Austria
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