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Zhao T, Scholl A, Zavaliche F, Lee K, Barry M, Doran A, Cruz MP, Chu YH, Ederer C, Spaldin NA, Das RR, Kim DM, Baek SH, Eom CB, Ramesh R. Electrical control of antiferromagnetic domains in multiferroic BiFeO3 films at room temperature. NATURE MATERIALS 2006; 5:823-9. [PMID: 16951676 DOI: 10.1038/nmat1731] [Citation(s) in RCA: 282] [Impact Index Per Article: 14.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/22/2006] [Accepted: 07/27/2006] [Indexed: 05/11/2023]
Abstract
Multiferroic materials, which offer the possibility of manipulating the magnetic state by an electric field or vice versa, are of great current interest. In this work, we demonstrate the first observation of electrical control of antiferromagnetic domain structure in a single-phase multiferroic material at room temperature. High-resolution images of both antiferromagnetic and ferroelectric domain structures of (001)-oriented multiferroic BiFeO3 films revealed a clear domain correlation, indicating a strong coupling between the two types of order. The ferroelectric structure was measured using piezo force microscopy, whereas X-ray photoemission electron microscopy as well as its temperature dependence was used to detect the antiferromagnetic configuration. Antiferromagnetic domain switching induced by ferroelectric polarization switching was observed, in agreement with theoretical predictions.
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Tenne DA, Bruchhausen A, Lanzillotti-Kimura ND, Fainstein A, Katiyar RS, Cantarero A, Soukiassian A, Vaithyanathan V, Haeni JH, Tian W, Schlom DG, Choi KJ, Kim DM, Eom CB, Sun HP, Pan XQ, Li YL, Chen LQ, Jia QX, Nakhmanson SM, Rabe KM, Xi XX. Probing Nanoscale Ferroelectricity by Ultraviolet Raman Spectroscopy. Science 2006; 313:1614-6. [PMID: 16973874 DOI: 10.1126/science.1130306] [Citation(s) in RCA: 273] [Impact Index Per Article: 14.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
We demonstrated that ultraviolet Raman spectroscopy is an effective technique to measure the transition temperature (Tc) in ferroelectric ultrathin films and superlattices. We showed that one-unit-cell-thick BaTiO3 layers in BaTiO3/SrTiO3 superlattices are not only ferroelectric (with Tc as high as 250 kelvin) but also polarize the quantum paraelectric SrTiO3 layers adjacent to them. Tc was tuned by approximately 500 kelvin by varying the thicknesses of the BaTiO3 and SrTiO3 layers, revealing the essential roles of electrical and mechanical boundary conditions for nanoscale ferroelectricity.
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Kim DM, Kigawa T, Choi CY, Yokoyama S. A highly efficient cell-free protein synthesis system from Escherichia coli. EUROPEAN JOURNAL OF BIOCHEMISTRY 1996; 239:881-6. [PMID: 8774739 DOI: 10.1111/j.1432-1033.1996.0881u.x] [Citation(s) in RCA: 173] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
We modified a cell-free coupled transcription/translation system from Escherichia coli with the T7 phage RNA polymerase, and achieved a productivity as high as 0.4 mg protein/ml reaction mixture. First, we found that the optimal concentrations of phosphoenolpyruvate and poly(ethylene glycol) are interdependent; higher concentrations of the former should be used at higher concentrations of the latter. Second, the use of a condensed 30000 x g cell extract, in place of the conventional one, significantly increased the initial rate of protein synthesis. This phenomenon was demonstrated to be due to a reason other than elimination of inhibitory molecule(s) from the extract. For this system with the condensed extract, the phosphoenolpyruvate and poly(ethylene glycol) concentrations were again co-optimized, resulting in production of chloramphenicol acetyltransferase at a productivity of 0.3 mg/ml. Finally, the productivity was further increased up to 0.4 mg/ml, by supplementation of the pool of amino acids. This improved cell-free protein synthesis system is superior in productivity to any other cell-free systems reported so far, including the continuous-flow cell-free system.
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Lee JH, Ju YM, Kim DM. Platelet adhesion onto segmented polyurethane film surfaces modified by addition and crosslinking of PEO-containing block copolymers. Biomaterials 2000; 21:683-91. [PMID: 10711965 DOI: 10.1016/s0142-9612(99)00197-0] [Citation(s) in RCA: 168] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Polyethylene oxide (PEO) surfaces were prepared by the addition of PEO-containing amphiphilic block copolymers as surface modifying additives and of dicumyl peroxide (DCP) as a crosslinking agent in segmented polyurethane (PU). PEO-polypropylene oxide-PEO triblock copolymers (Pluronics) with different PEO chain length (from 0 to 98) were used as the surface modifying additives. The PEO additives in the PU film were then crosslinked to be stably entrapped in the PU matrix. The crosslinking was done by free radicals produced from the decomposition of DCP in the film through heating (120 degrees C) or ultraviolet irradiation (254 nm). The surface properties of the PEO additive-entrapped PU films were investigated by the measurement of water contact angles and electron spectroscopy for chemical analysis. The bulk properties such as water absorption, long-term film stability, and tensile strength and elongation at break, were also investigated. It was observed that addition of a small amount (5 wt% based on PU) of the PEO additives resulted in a considerable change of surface characteristics. The PEO additives were stably entrapped in the PU films by crosslinking of them, without significant changes of bulk properties of the films. From the platelet adhesion test on the prepared PEO additive-containing film surfaces, it was observed that the platelet adhesion on the surfaces decreases with increase in PEO chain length of PEO additives. The film surface containing additive with long PEO chains (chain length of 98) was particularly effective in preventing platelet adhesion. The crosslinking of the PEO additives in PU films did not affect the behavior of platelet adhesion on the surfaces; the films with crosslinked PEO additives showed similar platelet adhesion on the surfaces to the films with uncrosslinked ones.
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Abstract
During the past decade, obesity has substantially increased in Korea, and this is leading to dramatic increases in complications such as type 2 diabetes. In this review, we discuss the past and the current situation of obesity in Korea based on the national health and nutrition surveys of 1995, 1998, and 2001. Because Korea is geographically isolated with relatively few migrants and has a low level of genetic heterogeneity, this report demonstrates the impact of environmental factors on the development of obesity beyond epidemiological information about one of the Asian countries. The third national health and nutrition survey reported in 2001 announced that the overall prevalence of obesity [body mass index (BMI) > or = 25.0 kg m(-2)] in Korean adults is 30.6% (32.4% in men and 29.4% in women). The prevalence of obesity in adults and children has increased rapidly from 1990s through the beginning of the new millennium and is steadily increasing in parallel with our rapid socio-economic progress. In particular, special attention should be paid to two groups in hormonal transition: first, middle-aged men and women who experience a great increase in body weight, BMI and waist circumference because of andropause or menopause, and second, adolescents in middle to high school who are preparing for qualification or entrance examinations and are prone to overnutrition or nutritional imbalance and physical inactivity.
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Review |
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Sayre D, Kirz J, Feder R, Kim DM, Spiller E. Transmission microscropy of unmodified biological materials: comparative radiation dosages with electrons and ultrasoft x-ray photons. Ultramicroscopy 1977; 2:337-49. [PMID: 919076 DOI: 10.1016/s0304-3991(76)91997-5] [Citation(s) in RCA: 129] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
The minimum radiation dosage in a specimen consistent with transmission microscopy at resolution d and specimen thickness t is calculated for model specimens resembling biological materials in their natural state. The calculations cover 10(4)-10(7) eV electrons and 1.3-90 A photons in a number of microscopy modes. The results indicate that over a considerable part of the (t,d)-plane transmission microscopy on such specimens can be carried out at lower dosage with photons than with electrons. Estimates of the maximum resolutions obtainable with electrons and photons, consistent with structural survival of the specimen, are obtained, as are data on optimal operating conditions for microscopy with the two particles.
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Comparative Study |
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Kim DM, Choi CY. A semicontinuous prokaryotic coupled transcription/translation system using a dialysis membrane. Biotechnol Prog 1996; 12:645-9. [PMID: 8879155 DOI: 10.1021/bp960052l] [Citation(s) in RCA: 128] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
This report describes a novel and simple cell-free protein synthesis system. In this paper, we prove that the short duration of protein synthesis in a conventional cell-free protein synthesis system of batch configuration can be attributed both to depletion of energy sources and deactivation of S30 extract by small-molecule byproducts produced during the protein synthesis. The reaction period of cell-free protein synthesis system could be extended through an operation of a continuous-flow cell-free protein synthesis system, which was originally developed by Spirin. However, inspite of the greatly extended reaction period, the final amount of cell-free produced protein was not significantly larger than that can be obtained from a batch system due to the reduced rate of protein synthesis. It was supposed that the reduced rate of protein synthesis in the continuous-flow system was attributed to leakage of translational components through the ultrafiltration membrane during the operation of the continuous-flow system. To solve such a problem of the continuous-flow system, we have developed and operated a novel reactor for cell-free protein synthesis. By use of this system, protein synthesis occurred for at least 14 h, yielding 1.2 mg/mL CAT protein. The present system is superior to the continuous-flow system as well as the conventional batch system in that it enables extremely high productivity without using any complex and hard-to-handle apparatus. As far as we know, the yield of cell-free protein synthesis given above is the best of the results reported to date.
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Baek SH, Park J, Kim DM, Aksyuk VA, Das RR, Bu SD, Felker DA, Lettieri J, Vaithyanathan V, Bharadwaja SSN, Bassiri-Gharb N, Chen YB, Sun HP, Folkman CM, Jang HW, Kreft DJ, Streiffer SK, Ramesh R, Pan XQ, Trolier-McKinstry S, Schlom DG, Rzchowski MS, Blick RH, Eom CB. Giant piezoelectricity on Si for hyperactive MEMS. Science 2011; 334:958-61. [PMID: 22096193 DOI: 10.1126/science.1207186] [Citation(s) in RCA: 127] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
Microelectromechanical systems (MEMS) incorporating active piezoelectric layers offer integrated actuation, sensing, and transduction. The broad implementation of such active MEMS has long been constrained by the inability to integrate materials with giant piezoelectric response, such as Pb(Mg(1/3)Nb(2/3))O(3)-PbTiO(3) (PMN-PT). We synthesized high-quality PMN-PT epitaxial thin films on vicinal (001) Si wafers with the use of an epitaxial (001) SrTiO(3) template layer with superior piezoelectric coefficients (e(31,f) = -27 ± 3 coulombs per square meter) and figures of merit for piezoelectric energy-harvesting systems. We have incorporated these heterostructures into microcantilevers that are actuated with extremely low drive voltage due to thin-film piezoelectric properties that rival bulk PMN-PT single crystals. These epitaxial heterostructures exhibit very large electromechanical coupling for ultrasound medical imaging, microfluidic control, mechanical sensing, and energy harvesting.
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Research Support, U.S. Gov't, Non-P.H.S. |
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127 |
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Fong DD, Kolpak AM, Eastman JA, Streiffer SK, Fuoss PH, Stephenson GB, Thompson C, Kim DM, Choi KJ, Eom CB, Grinberg I, Rappe AM. Stabilization of monodomain polarization in ultrathin PbTiO3 films. PHYSICAL REVIEW LETTERS 2006; 96:127601. [PMID: 16605959 DOI: 10.1103/physrevlett.96.127601] [Citation(s) in RCA: 125] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/22/2005] [Indexed: 05/08/2023]
Abstract
Using in situ high-resolution synchrotron x-ray scattering, the Curie temperature TC has been determined for ultrathin c-axis epitaxial PbTiO3 films on conducting substrates (SrRuO3 on SrTiO3), with surfaces exposed to a controlled vapor environment. The suppression of TC was relatively small, even for the thinnest film (1.2 nm). We observe that 180 degrees stripe domains do not form, indicating that the depolarizing field is compensated by free charge at both interfaces. This is confirmed by ab initio calculations that find polar ground states in the presence of ionic adsorbates.
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Wang LF, Kim DM, Lee CY. Effects of heat processing and storage on flavanols and sensory qualities of green tea beverage. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2000; 48:4227-4232. [PMID: 10995342 DOI: 10.1021/jf0003597] [Citation(s) in RCA: 115] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
This research was conducted to understand the effects of heat processing and storage on flavanols and sensory qualities of green tea extract. Fresh tea leaves were processed into steamed and roasted green teas by commercial methods and then extracted with hot water (80 degrees C) at 1:160 ratio (tea leaves/water by weight). Green tea extracts were heat processed at 121 degrees C for 1 min and then stored at 50 degrees C to accelerate chemical reactions. Changes in flavanol composition and sensory qualities of green tea extracts during processing and storage were measured. Eight major flavanols (catechin, epicatechin, gallocatechin, epigallocatechin, epicatechin gallate, catechin gallate, epigallocatechin gallate, and gallocatechin gallate) were identified in the processed tea extract. Among them, epigallocatechin gallate and epigallocatechin appeared to play the key role in the changes of sensory qualities of processed green tea beverage. The steamed tea leaves produced a more desirable quality of processed green tea beverage than the roasted ones.
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115 |
11
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Kim DM, Swartz JR. Prolonging cell-free protein synthesis by selective reagent additions. Biotechnol Prog 2000; 16:385-90. [PMID: 10835240 DOI: 10.1021/bp000031y] [Citation(s) in RCA: 110] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Factors causing the early cessation of protein synthesis have been studied in a cell-free system from Escherichia coli. We discovered that phosphoenol pyruvate (PEP), the secondary energy source for ATP regeneration, and several amino acids are rapidly degraded during the cell-free protein synthesis reaction. The degradation of such compounds takes place even in the absence of protein synthesis. This degradation severely reduces the capacity for protein synthesis. The lost potency was completely recovered when the reaction mixture was supplied with additional PEP and amino acids. Of the 20 amino acids, only arginine, cysteine, and tryptophan were required to restore system activity. Through repeated additions of PEP, arginine, cysteine,and tryptophan, the duration of protein synthesis was greatly extended. In this fed-batch reaction, after a 2 h incubation, the level of cell-free synthesized chloramphenicol acetyl transferase (CAT) reached 350 microg/mL, which is 3.5 times the yield of the batch reaction. Addition of fresh magnesium further extended the protein synthesis. As a result, through coordinated additions of PEP, arginine, cysteine, tryptophan, and magnesium, the final concentration of cell-free synthesized CAT increased more than 4-fold compared to a batch reaction. SDS-PAGE analysis of such a fed-batch reaction produced an obvious band of CAT upon Coomassie Blue staining.
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110 |
12
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Sayre D, Kirz J, Feder R, Kim DM, Spiller E. Potential operating region for ultrasoft x-ray microscopy of biological materials. Science 1977; 196:1339-40. [PMID: 867033 DOI: 10.1126/science.867033] [Citation(s) in RCA: 88] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Calculations are presented which indicate an extensive suboptical region in the microscopy of biological materials in their natural state which is accessible to ultrasoft x-ray transmission microscopy. Throughout most of the region, radiation dosage levels to the specimen are lower than in electron microscopy.
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88 |
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Eshghjoo S, Kim DM, Jayaraman A, Sun Y, Alaniz RC. Macrophage Polarization in Atherosclerosis. Genes (Basel) 2022; 13:genes13050756. [PMID: 35627141 PMCID: PMC9142092 DOI: 10.3390/genes13050756] [Citation(s) in RCA: 62] [Impact Index Per Article: 20.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2022] [Revised: 04/23/2022] [Accepted: 04/24/2022] [Indexed: 02/06/2023] Open
Abstract
The implication of the heterogeneous spectrum of pro- and anti-inflammatory macrophages (Macs) has been an important area of investigation over the last decade. The polarization of Macs alters their functional phenotype in response to their surrounding microenvironment. Macs are the major immune cells implicated in the pathogenesis of atherosclerosis. A hallmark pathology of atherosclerosis is the accumulation of pro-inflammatory M1-like macrophages in coronary arteries induced by pro-atherogenic stimuli; these M1-like pro-inflammatory macrophages are incapable of digesting lipids, thus resulting in foam cell formation in the atherosclerotic plaques. Recent findings suggest that the progression and stability of atherosclerotic plaques are dependent on the quantity of infiltrated Macs, the polarization state of the Macs, and the ratios of different types of Mac populations. The polarization of Macs is defined by signature markers on the cell surface, as well as by factors in intracellular and intranuclear compartments. At the same time, pro- and anti-inflammatory polarized Macs also exhibit different gene expression patterns, with differential cellular characteristics in oxidative phosphorylation and glycolysis. Macs are reflective of different metabolic states and various types of diseases. In this review, we discuss the major differences between M1-like Macs and M2-like Macs, their associated metabolic pathways, and their roles in atherosclerosis.
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Wu CS, Wei Q, Wang H, Kim DM, Balderas M, Wu G, Lawler J, Safe S, Guo S, Devaraj S, Chen Z, Sun Y. Protective Effects of Ghrelin on Fasting-Induced Muscle Atrophy in Aging Mice. J Gerontol A Biol Sci Med Sci 2020; 75:621-630. [PMID: 30407483 PMCID: PMC7328200 DOI: 10.1093/gerona/gly256] [Citation(s) in RCA: 57] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2018] [Indexed: 12/12/2022] Open
Abstract
Sarcopenia is the aging-associated progressive loss of skeletal muscle; however, the pathogenic mechanism of sarcopenia is not clear. The orexigenic hormone ghrelin stimulates growth hormone secretion, increases food intake, and promotes adiposity. Here we showed that fasting-induced muscle loss was exacerbated in old ghrelin-null (Ghrl-/-) mice, exhibiting decreased expression of myogenic regulator MyoD and increased expression of protein degradation marker MuRF1, as well as altered mitochondrial function. Moreover, acylated ghrelin and unacylated ghrelin treatments significantly increased mitochondrial respiration capacity in muscle C2C12 cells. Consistently, acylated ghrelin and unacylated ghrelin treatments effectively increased myogenic genes and decreased degradation genes in the muscle in fasted old Ghrl-/- mice, possibly by stimulating insulin and adenosine monophosphate-activated protein kinase pathways. Furthermore, Ghrl-/- mice showed a profile of pro-inflammatory gut microbiota, exhibiting reduced butyrate-producing bacteria Roseburia and ClostridiumXIVb. Collectively, our results showed that ghrelin has a major role in the maintenance of aging muscle via both muscle-intrinsic and -extrinsic mechanisms. Acylated ghrelin and unacylated ghrelin enhanced muscle anabolism and exerted protective effects for muscle atrophy. Because unacylated ghrelin is devoid of the obesogenic side effect seen with acylated ghrelin, it represents an attractive therapeutic option for sarcopenia.
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Research Support, N.I.H., Extramural |
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57 |
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Kim DM, Lee IH, Song CJ. Uremic Encephalopathy: MR Imaging Findings and Clinical Correlation. AJNR Am J Neuroradiol 2016; 37:1604-9. [PMID: 27127003 DOI: 10.3174/ajnr.a4776] [Citation(s) in RCA: 56] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2015] [Accepted: 02/12/2016] [Indexed: 11/07/2022]
Abstract
BACKGROUND AND PURPOSE Uremic encephalopathy is a metabolic disorder in patients with renal failure. The purpose of this study was to describe the MR imaging findings of uremic encephalopathy. MATERIALS AND METHODS This study retrospectively reviewed MR imaging findings in 10 patients with clinically proved uremic encephalopathy between May 2005 and December 2014. Parameters evaluated were lesion location and appearance; MR signal intensity of the lesions on T1WI, T2WI, and T2 fluid-attenuated inversion recovery images; the presence or absence of restricted diffusion on diffusion-weighted images and apparent diffusion coefficient maps; and the reversibility of documented signal-intensity abnormalities on follow-up MR imaging. RESULTS MR imaging abnormalities accompanying marked elevation of serum creatinine (range, 4.3-11.7 mg/dL) were evident in the 10 patients. Nine patients had a history of chronic renal failure with expansile bilateral basal ganglia lesions, and 1 patient with acute renal failure had reversible largely cortical lesions. Two of 6 patients with available arterial blood gas results had metabolic acidosis. All basal ganglia lesions showed expansile high signal intensity (lentiform fork sign) on T2WI. Varied levels of restricted diffusion and a range of signal intensities on DWI were evident and were not correlated with serum Cr levels. All cortical lesions demonstrated high signal intensity on T2WI. Four patients with follow-up MR imaging after hemodialysis showed complete resolution of all lesions. CONCLUSIONS The lentiform fork sign is reliable in the early diagnosis of uremic encephalopathy, regardless of the presence of metabolic acidosis. Cytotoxic edema and/or vasogenic edema on DWI/ADC maps may be associated with uremic encephalopathy.
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Journal Article |
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56 |
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Kim DM, Brecher ME, Bland LA, Estes TJ, McAllister SK, Aguero SM, Carmen RA, Nelson EJ. Prestorage removal of Yersinia enterocolitica from red cells with white cell-reduction filters. Transfusion 1992; 32:658-62. [PMID: 1381532 DOI: 10.1046/j.1537-2995.1992.32792391041.x] [Citation(s) in RCA: 50] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Prestorage removal of phagocytic white cells (WBCs) may increase the survivability of contaminating bacteria in units of stored red cells. Fourteen units of whole blood were inoculated with 65 colony-forming units per mL of Yersinia enterocolitica (serotype O:3) and processed into AS-3-preserved red cells. Five red cell units were filtered with a prototype third-generation filter and five red cell units with a second generation filter. WBC reduction was performed on the day of collection. Four red cell units were not filtered. Three noninoculated whole blood units served as negative controls; two were filtered (one with each type of WBC-reduction filter) and one remained unfiltered. All red cell units were then stored at 4 degrees C for 42 days. One of the five filtered red cell units (20%) in each filter group supported growth of Y. enterocolitica. In contrast, 4 (100%) of 4 unfiltered inoculated red cell units had growth (p = 0.04). Overall, 2 (20%) of 10 units of WBC-reduced red cells supported the growth of Y. enterocolitica, as compared to 100 percent of unfiltered red cell units after inoculation (p = 0.015). Bacterial contamination was not detected in any of the three noninoculated units. It can be concluded that prestorage WBC filtration significantly reduces the potential for growth of Y. enterocolitica in red cells stored at 4 degrees C for 42 days.
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Comparative Study |
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Kim DM, Brecher ME, Bland LA, Estes TJ, Carmen RA, Nelson EJ. Visual identification of bacterially contaminated red cells. Transfusion 1992; 32:221-5. [PMID: 1557802 DOI: 10.1046/j.1537-2995.1992.32392213804.x] [Citation(s) in RCA: 45] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
There have been increasing numbers of reports of transfusion-acquired Yersinia enterocolitica bacteremia (including several fatal cases). Fifteen units of whole blood were inoculated with various concentrations of Y. enterocolitica serotype 0:3 and processed into AS-3 preserved red cells (RBCs). Consistent growth of the organism was found at inoculum concentrations greater than or equal to 10 colony-forming units per mL. In all 13 units of RBCs that supported the growth of Y. enterocolitica, a darkening in color (due to hemolysis and a decrease in pO2) was observed in the bag. The attached sample segments, which were sealed from the main unit, remained sterile and did not darken. This color change was apparent in all the contaminated units by Day 35, which was 1.5 to 2 weeks after the bacteria were first detected in cultures of the blood. Hence, by comparison of the color of the segment tubing with that of the unit itself, units grossly contaminated with Y. enterocolitica can be identified prior to transfusion. Moreover, review of photographs on file at the Centers for Disease Control revealed this dramatic color change in 2 units of blood that caused transfusion-transmitted sepsis (Enterobacter agglomerans and an unidentified gram-negative bacillus, not Yersinia sp.), which demonstrated that the color change was not limited to Y. enterocolitica. This method of visual identification of contaminated units of blood could decrease the incidence of posttransfusion bacterial sepsis.
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Yang SJ, Min KW, Gupta SK, Park JY, Shivane VK, Pitale SU, Agarwal PK, Sosale A, Gandhi P, Dharmalingam M, Mohan V, Mahesh U, Kim DM, Kim YS, Kim JA, Kim PK, Baik SH. A multicentre, multinational, randomized, placebo-controlled, double-blind, phase 3 trial to evaluate the efficacy and safety of gemigliptin (LC15-0444) in patients with type 2 diabetes. Diabetes Obes Metab 2013; 15:410-6. [PMID: 23170990 DOI: 10.1111/dom.12042] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/27/2012] [Revised: 09/27/2012] [Accepted: 11/09/2012] [Indexed: 01/21/2023]
Abstract
AIM This study was designed to assess the efficacy and safety of the dipeptidyl peptidase IV inhibitor gemigliptin (LC15-0444) 50 mg versus placebo in patients with type 2 diabetes. METHODS We conducted a 24-week, randomized, double-blind, placebo-controlled phase III trial in 182 patients (74 from Korea and 108 from India) with type 2 diabetes. After an initial 2 weeks of a diet and exercise programme followed by 2 weeks of a single-blind placebo run-in period, eligible patients were randomized to gemigliptin 50 mg or placebo, receiving the assigned treatment for 24 weeks. HbA1c and fasting plasma glucose (FPG) were measured periodically, and oral glucose tolerance test was performed at baseline and weeks 12 and 24. RESULTS At week 24, gemigliptin treatment led to significant reductions in HbA1c measurements compared to placebo (adjust mean after subtracting the placebo effect size: -0.71%, 95% confidence interval: -1.04 to -0.37%). A significantly greater proportion of patients achieved an HbA1c <7% with gemigliptin than with placebo. The placebo-subtracted FPG change from baseline at week 24 was -19.80 mg/dl. The overall incidence rates for adverse events were similar in the gemigliptin and placebo groups. CONCLUSIONS This study showed the efficacy and safety of gemigliptin 50 mg administered once daily as a monotherapy for type 2 diabetes patients.
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Clinical Trial, Phase III |
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Kim DM, Lee YM, Back JH, Yang TY, Lee JH, Song HJ, Shim SK, Hwang KJ, Park MY. A serosurvey of Orientia tsutsugamushi from patients with scrub typhus. Clin Microbiol Infect 2009; 16:447-51. [PMID: 19778303 DOI: 10.1111/j.1469-0691.2009.02865.x] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Many countries where scrub typhus is endemic use their own cutoff values for antibody titres to differentiate between cured cases and current infections. To establish an antibody titre cutoff value, one needs to investigate the seroprevalence in endemic areas, and the duration of the increase in titre after complete cure. We conducted a follow-up study of anti-Orientia tsutsugamushi antibody titres using indirect immunofluorescence assays (IFA) and passive haemagglutination assays (PHA) in patients with scrub typhus. After the onset of symptoms, IgM antibody titres increased gradually over 2-3 weeks, peaked at about 4 weeks, and started to decrease rapidly between 4 and 5 weeks. At 1-year follow-up, the median IgM value was 1:10. Out of 77 patients who were tested at that time, 36 (47%) had IgM titres > or =1:20, and none had titres exceeding 1:80. Over the first 2 weeks, IgG antibody titres increased sharply, peaked at about 4 weeks and decreased rather gradually thereafter, with a median titre of 1:128 maintained up to the 18th month. At 1-year follow-up, five out of 77 patients (6.5%) had titres > or =1:1,024 and 57% had titres > or =1:128. Based on these results, a cutoff value of > or =1:160 for IgM antibody should differentiate between previous and current infections in endemic areas such as Korea and Japan, where scrub typhus occurs mainly in the autumn.
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Research Support, Non-U.S. Gov't |
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Min SH, Kim DM, Heo YS, Kim YI, Kim HM, Kim J, Han YM, Kim IC, Yoo OJ. New p53 target, phosphatase of regenerating liver 1 (PRL-1) downregulates p53. Oncogene 2008; 28:545-54. [PMID: 18997816 DOI: 10.1038/onc.2008.409] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Most of the p53 target genes, all except MDM2, COP1 and PIRH2, perform functions in apoptosis, differentiation and cell cycle arrest. The aforementioned oncogenes downregulate p53 through a negative feedback mechanism, and thus contribute to tumor development. In this study, we report a new p53 target, PRL-1, which is believed to be a significant regulator in the development and metastasis of a variety of cancer types. Phosphatase of regenerating liver 1 (PRL-1) overexpression reduced the levels of endogenous and exogenous p53 proteins, and inhibited p53-mediated apoptosis. On the other hand, the ablation of PRL-1 by small interfering RNA (siRNA) increased p53 protein levels. The p53 downregulation was mediated by p53 ubiquitination and subsequent proteasomal degradation. Furthermore, p53 ubiquitination by PRL-1 was achieved through two independent pathways, by inducing PIRH2 transcription and by inducing MDM2 phosphorylation through Akt signaling. In addition, we showed that the PRL-1 gene harbors a p53 response element in the first intron, and its transcription is regulated by the p53 protein. These findings imply that the new oncogenic p53 target, PRL-1, may contribute to tumor development by the downregulation of p53 by a negative feedback mechanism.
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Research Support, Non-U.S. Gov't |
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Ahammed M, Chae BJ, Lohakare J, Keohavong B, Lee MH, Lee SJ, Kim DM, Lee JY, Ohh SJ. Comparison of aviary, barn and conventional cage raising of chickens on laying performance and egg quality. ASIAN-AUSTRALASIAN JOURNAL OF ANIMAL SCIENCES 2014; 27:1196-203. [PMID: 25083115 PMCID: PMC4109877 DOI: 10.5713/ajas.2013.13394] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/05/2013] [Revised: 11/21/2013] [Accepted: 09/16/2013] [Indexed: 11/27/2022]
Abstract
This study intended to compare the productive performance of three different layer raising systems; conventional cage (CC), barn (BR) and aviary (AV). The AV is welfare bestowed housing that allows free locomotion for birds within the BR. The BR allows bird's free locomotion inside BR but without multilevel structures. Both pullets and cockerels were housed together in both AV and BR, but only pullets in CC. Seventeen weeks old Lohmann Brown Lite (n = 800) pullets were housed in AV during this study. The same age layer pullets were simultaneously assigned to either at CC or BR to compare egg production performance with AV. The duration of experiment was 40 weeks (from 21st to 60th week). There were no remarkable differences in egg production, hen day egg production (HDEP) and average egg weight among three rearing systems. First 20 weeks (phase-1) average HDEP (%) of AV, CC, and BR were 85.9, 88.8, 87.1 and average egg weights (g) were 57.5, 59.9, and 56.9 respectively. Those of the remaining 20 weeks (phase-2) were 87.1, 87.9, 85.5 and 64.2, 63.0 62.1, respectively. Daily feed intakes (122 g, 110 g, 125 g); feed conversion ratio (2.4, 2.1, 2.5) and daily egg mass (53.9 g, 54.4 g, 52.8 g) data from AV, CC, and BR were not influenced significantly by the respective raising systems. Daily feed intake of layers in both AV (124 g) and BR (127 g) tended to be higher than that in CC (113 g) during phase-2. Overall, exterior egg quality (dirty and cracked eggs) in both phases was superior in BR compared with AV and CC, whereas CC generated intermediate results. This study indicated that the HDEP per se in AV and BR were not significantly different from that in CC. The study implied that the facility depreciation cost for AV and cost for increased feed intake in AV compared to CC are believed to be critical to evaluate the cost effectiveness of egg production in AV.
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Hyung SM, Kim DM, Hong C, Youn DH. Optic disc of the myopic eye: relationship between refractive errors and morphometric characteristics. KOREAN JOURNAL OF OPHTHALMOLOGY 1992; 6:32-5. [PMID: 1434043 DOI: 10.3341/kjo.1992.6.1.32] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Because the optic disc in myopic eyes is different from a normal optic disc, there are many difficulties in examining the optic discs of myopic eyes. To study optic disc change due to myopia, we performed a morphometrical study of stereophotographs of 61 men, 109 eyes, who had no glaucoma history. The range of refractive error was from +0.75 diopter to -12.75 diopter, and all subjects had intraocular pressure below or equal to 21 mmHg. According to the increase in the myopic degree, the temporal slope of the disc cup was significantly decreased, but the ratio of the vertical disc diameter (VDD) to the horizontal disc diameter and the ratio of the width of peripapillary atrophy (PPA) to the VDD were significantly increased. The above results suggests that in high myopia the optic disc was tilted and the rim-cup border was indistinct and there are some problems in the estimation of the morphometric parameters. Also in evaluation of the PPA of myopic glaucoma patients, there may be some difficulty in deciding whether it is due to myopic change or glaucomatous damage.
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Han SK, Park KH, Kim DM, Chang BL. Effect of diode laser trans-scleral cyclophotocoagulation in the management of glaucoma after intravitreal silicone oil injection for complicated retinal detachments. Br J Ophthalmol 1999; 83:713-7. [PMID: 10340982 PMCID: PMC1723083 DOI: 10.1136/bjo.83.6.713] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
AIMS To evaluate the effect of trans scleral cyclophotocoagulation (TSCPC) on intraocular pressure (IOP) in the eyes retaining intravitreal silicone oil with medically uncontrolled secondary glaucoma following intravitreal silicone oil injection. METHODS Medical records of 11 eyes of 11 patients who underwent TSCPC for medically uncontrolled glaucoma without pupillary block following intravitreal silicone oil injection for complicated retinal detachment were reviewed retrospectively. In all cases, intravitreal silicone oil was not removed for fear of retinal redetachment. Diode laser contact TSCPC was performed at a power of 1.5-2.5 W, for a duration of 2 seconds, and with 20-27 applications. IOP, number of glaucoma medications, and success rate were evaluated. RESULTS After a mean follow up period of 52.5 (SD 8.2) (range 42-68) weeks, the mean pretreatment level of IOP, 43.0 (14.4) (26-67) mmHg, had fallen to 14.5 (4.3) (7-20) mm Hg (p=0.003). The number of glaucoma medications was reduced from 2.6 (0.8) to 0.6 (1.0) (p= 0.005). Qualified success was achieved in nine eyes (81.8%) and complete success in six (54.5%). After TSCPC, patients' retinal status had not changed. CONCLUSION Patients with medically uncontrolled glaucoma secondary to intravitreal silicone oil injection can be treated with TSCPC in spite of the retained intravitreal silicone oil.
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Woo SJ, Park KH, Kim DM. Comparison of localised nerve fibre layer defects in normal tension glaucoma and primary open angle glaucoma. Br J Ophthalmol 2003; 87:695-8. [PMID: 12770963 PMCID: PMC1771704 DOI: 10.1136/bjo.87.6.695] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
AIM To compare the pattern of localised nerve fibre layer (NFL) defects in normal tension glaucoma (NTG) and primary open angle glaucoma (POAG). METHODS 50 NTG eyes and 36 POAG eyes, all with localised NFL defects, were enrolled. On retinal NFL photography, the proximity of the defect to the centre of the fovea (angle alpha) and the sum of the angular width of the defects (angle beta) were determined. Angle alpha was the angle made by a line from the centre of the fovea to the disc centre and a line from the disc centre to the disc margin, where the nearest border of the defect met. The patterns of localised NFL defects in NTG and POAG were compared with angles alpha and beta. Independent t test was used for statistical analysis. RESULTS Angle alpha in NTG (35.1 (SD 20.0) degrees ) was significantly smaller than that of POAG (45.9 (21.9) degrees ) (p=0.02), while angle beta in NTG (49.0 (31.9) degrees ) was significantly larger than that of POAG (33.1 (23.9) degrees ) (p=0.01). CONCLUSIONS The pattern of NFL defects in NTG was different from that in POAG. Localised NFL defects in NTG were closer to the fovea and wider in width than those in POAG.
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Kang JG, Lee JJ, Kim DM, Kim JA, Kim CS, Hahm TS, Lee BD. Blocking noise but not music lowers bispectral index scores during sedation in noisy operating rooms. J Clin Anesth 2008; 20:12-6. [PMID: 18346603 DOI: 10.1016/j.jclinane.2007.06.005] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2006] [Revised: 05/31/2007] [Accepted: 06/01/2007] [Indexed: 11/25/2022]
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