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Hoarty DJ, Allan P, James SF, Brown CRD, Hobbs LMR, Hill MP, Harris JWO, Morton J, Brookes MG, Shepherd R, Dunn J, Chen H, Von Marley E, Beiersdorfer P, Chung HK, Lee RW, Brown G, Emig J. Observations of the effect of ionization-potential depression in hot dense plasma. PHYSICAL REVIEW LETTERS 2013; 110:265003. [PMID: 23848885 DOI: 10.1103/physrevlett.110.265003] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/28/2013] [Indexed: 06/02/2023]
Abstract
The newly commissioned Orion laser system has been used to study dense plasmas created by a combination of short pulse laser heating and compression by laser driven shocks. Thus the plasma density was systematically varied between 1 and 10 g/cc by using aluminum samples buried in plastic foils or diamond sheets. The aluminum was heated to electron temperatures between 500 and 700 eV allowing the plasma conditions to be diagnosed by K-shell emission spectroscopy. The K-shell spectra show the effect of the ionization potential depression as a function of density. The data are compared to simulated spectra which account for the change in the ionization potential by the commonly used Stewart and Pyatt prescription and an alternative due to Ecker and Kröll suggested by recent x-ray free-electron laser experiments. The experimental data are in closer agreement with simulations using the model of Stewart and Pyatt.
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Cho E, Kim HJ, Kim GM, Kum J, Chung HK, Lyu CJ, Ahn JB, Shin SJ. Assessment of efficiency and safety of the comprehensive Chemotherapy Assistance Program for ordering oncology medications. Int J Med Inform 2013; 82:504-13. [PMID: 23481407 DOI: 10.1016/j.ijmedinf.2013.02.001] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2012] [Revised: 01/31/2013] [Accepted: 02/03/2013] [Indexed: 10/27/2022]
Abstract
PURPOSE To assess whether the newly developed Comprehensive Chemotherapy Assistance Program (CAP) decreases errors and increases performance efficiency in ordering oncology medications as compared to the existing Computerized Physician Order Entry (CPOE) system, the Order Communication System (OCS). METHODS All chemotherapy prescriptions ordered using OCS and CAP systems during the first year of CAP implementation were prospectively analyzed to identify near-miss cases. The efficiency outcomes were determined in a trial setting with eight predefined hypothetical chemotherapy regimens, each with four measures of the average time, movement distance on the screen, maximum input interval time, and number of mouse or keystrokes per order. A total of 14 physicians participated in the study, and each regimen was ordered twice, once using CAP and once using OCS. RESULTS For all near-miss types, CAP orders showed significant improvements as compared with OCS orders (p<0.0001). For CAP orders, incorrect dose and agent errors were reduced by 43.9% and 31.6%, respectively. Compared with OCS orders, regimen defects, drug omissions, and incorrect data input errors were reduced by more than 70% for CAP orders. For all four efficiency measures, a statistically significant competence was identified when physicians ordered a chemotherapy prescription with CAP as compared with OCS (p<0.0001). CONCLUSIONS These results demonstrate the superiority of CAP over the existing CPOE system for ordering oncology medications with regard to safety and efficiency.
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Chung HK, Cho Y, Shin MJ. Alcohol use behaviors, fat intake and the function of pancreatic β-cells in non-obese, healthy Korean males: findings from 2010 Korea National Health and Nutrition Examination Survey. ANNALS OF NUTRITION AND METABOLISM 2013; 62:129-36. [PMID: 23392227 DOI: 10.1159/000345587] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/10/2012] [Accepted: 10/27/2012] [Indexed: 01/13/2023]
Abstract
AIMS In the present study, we aimed to identify dietary factors related to insulin secretion function especially in healthy, non-obese Korean males. METHODS Data were obtained from the Korea National Health and Nutrition Examination Survey V-1 (KNHANES V-1). Nine hundred and twenty male adults aged >30 years of normal weight were included, excluding those with type 2 diabetes mellitus and liver disease. Alcohol use disorders identification test (AUDIT) score which represents alcohol use behaviors and nutrient intakes was used, and homeostasis model assessment of β-cell function (HOMA-B score) was calculated. RESULTS HOMA-B score was associated with age (p < 0.001), AUDIT score (p = 0.030), and percentage of fat from total energy intake (p = 0.002). HOMA-B scores in the problematic AUDIT group were significantly lower than those in the normal AUDIT group. In addition, HOMA-B scores in the lowest fat intake group were significantly lower than those in the medium fat intake group, but similar to those in the highest fat intake group. There was an interaction between alcohol use behaviors and percentage of fat from energy intake in determining HOMA-B score (p for interaction = 0.034). CONCLUSIONS Alcohol use behaviors and percentage of fat from energy intake were found to be associated with HOMA-B score in healthy, non-obese Korean males.
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Lee SM, Cho Y, Chung HK, Shin DH, Ha WK, Lee SC, Shin MJ. Effects of kimchi supplementation on blood pressure and cardiac hypertrophy with varying sodium content in spontaneously hypertensive rats. Nutr Res Pract 2012; 6:315-21. [PMID: 22977685 PMCID: PMC3439575 DOI: 10.4162/nrp.2012.6.4.315] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2012] [Revised: 06/07/2012] [Accepted: 07/09/2012] [Indexed: 01/19/2023] Open
Abstract
We tested the effects of dietary intake of freeze-dried Korean traditional fermented cabbage (generally known as kimchi) with varying amounts of sodium on blood pressure and cardiac hypertrophy in spontaneously hypertensive rats (SHRs). Wistar-Kyoto rats (WKY), as a control group, received a regular AIN-76 diet, and the SHRs were divided into four groups. The SHR group was fed a regular diet without kimchi supplementation, the SHR-L group was fed the regular diet supplemented with low sodium kimchi containing 1.4% salt by wet weight, which was provided in a freeze-dried form, the SHR-M group was supplemented with medium levels of sodium kimchi containing 2.4% salt, and the SHR-H group was supplemented with high sodium kimchi containing 3.0% salt. Blood pressure was measured over 6 weeks, and cardiac hypertrophy was examined by measuring heart and left ventricle weights and cardiac histology. SHRs showed higher blood pressure compared to that in WKY rats, which was further elevated by consuming high sodium containing kimchi but was not influenced by supplementing with low sodium kimchi. None of the SHR groups showed significant differences in cardiac and left ventricular mass or cardiomyocyte size. Levels of serum biochemical parameters, including blood urea nitrogen, creatinine, glutamic-oxaloacetic transaminase, glutamic-pyruvic transaminase, sodium, and potassium were not different among the groups. Elevations in serum levels of aldosterone in SHR rats decreased in the low sodium kimchi group. These results suggest that consuming low sodium kimchi may not adversely affect blood pressure and cardiac function even under a hypertensive condition.
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Lee YS, Choi I, Ning Y, Kim NY, Khatchadourian V, Yang D, Chung HK, Choi D, LaBonte MJ, Ladner RD, Nagulapalli Venkata KC, Rosenberg DO, Petasis NA, Lenz HJ, Hong YK. Interleukin-8 and its receptor CXCR2 in the tumour microenvironment promote colon cancer growth, progression and metastasis. Br J Cancer 2012; 106:1833-41. [PMID: 22617157 PMCID: PMC3364111 DOI: 10.1038/bjc.2012.177] [Citation(s) in RCA: 226] [Impact Index Per Article: 18.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
BACKGROUND Colorectal cancer (CRC) is a leading cause of death in the United States. Increased level of interleukin-8 (IL-8) and CXCR2 on tumours and in the tumour microenvironment has been associated with CRC growth, progression and recurrence in patients. Here, we aimed to evaluate the effects of tissue microenvironment-encoded IL-8 and CXCR2 on colon cancer progression and metastasis. METHODS A novel immunodeficient, skin-specific IL-8-expressing transgenic model was generated to evaluate colon cancer growth and metastasis. Syngeneic mouse colon cancer cells were grafted in CXCR2 knockout (KO) mice to study the contribution of CXCR2 in the microenvironment to cancer growth. RESULTS Elevated levels of IL-8 in the serum and tumour microenvironment profoundly enhanced the growth of human and mouse colon cancer cells with increased peri-tumoural angiogenesis, and also promoted the extravasation of the cancer cells into the lung and liver. The tumour growth was inhibited in CXCR2 KO mice with significantly reduced tumour angiogenesis and increased tumour necrosis. CONCLUSION Increased expression of IL-8 in the tumour microenvironment enhanced colon cancer growth and metastasis. Moreover, the absence of its receptor CXCR2 in the tumour microenvironment prevented colon cancer cell growth. Together, our study demonstrates the critical roles of the tumour microenvironment-encoded IL-8/CXCR2 in colon cancer pathogenesis, validating the pathway as an important therapeutic target.
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Chung HK, Lee HY. Drinking behaviors by stress level in Korean university students. Nutr Res Pract 2012; 6:146-54. [PMID: 22586504 PMCID: PMC3349037 DOI: 10.4162/nrp.2012.6.2.146] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2012] [Revised: 03/09/2012] [Accepted: 03/09/2012] [Indexed: 11/06/2022] Open
Abstract
The purposes of this study are to estimate the stress level of university students, and to verify the relationships between stress level and drinking behavior. A questionnaire survey was administered to 430 university students in the Gangwon area in Korea from November 5 to November 28, 2008, and data from 391 students were used for the final statistical analysis. The most stressful factor was "Worry about academic achievements" (2.86 by Likert-type 4 point scale). The subjects were divided into two groups, a low stress group (≤ 65.0) and a high stress group (≥ 66.0), by the mean value (65.1) and median value (66.0) of the stress levels. The drinking frequency was not different between the two stress groups, but the amount of alcohol consumption was significantly different (P < 0.05). The portion of students reporting drinking "7 glasses or over" was higher in the lower stress group than in the higher stress group. In addition, factor 6, "Lack of learning ability", was negatively correlated with drinking frequency and the amount of alcohol consumption (P < 0.05), and factor 3, "Worry about academic achievements", was negatively correlated with the amount of drinking (P < 0.05). The major motive for drinking was "When overjoyed or there is something to celebrate" (2.62), and the main expected effect of drinking was "Drinking enables me to get together with people and shape my sociability" (2.73). The higher stress group showed significantly higher scores on several items in the categories of motives (P < 0.01), negative experience (P < 0.05), and expected effects (P < 0.05) of drinking than the lower stress group. Our results imply that university students at the lower stress level may drink more from social motives in positive drinking environments, while those at the higher stress level may have more problematic-drinking despite their smaller amount of alcohol consumption.
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Choi J, Kim HY, Ju EJ, Jung J, Park J, Chung HK, Lee JS, Lee JS, Park HJ, Song SY, Jeong SY, Choi EK. Use of macrophages to deliver therapeutic and imaging contrast agents to tumors. Biomaterials 2012; 33:4195-203. [PMID: 22398206 DOI: 10.1016/j.biomaterials.2012.02.022] [Citation(s) in RCA: 158] [Impact Index Per Article: 13.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2011] [Accepted: 02/09/2012] [Indexed: 12/13/2022]
Abstract
Drug targeting to tumors with limited toxicity and enhanced efficacy of drug is one of the important goals for cancer treatment pharmaceutics. Monocytes/macrophages are able to migrate to tumor sites across the blood barriers by acting as Trojan horses carrying drug cargoes. Taking this advantage, we have intended to develop an efficient administration system using a biologically active carrier of mouse peritoneal macrophage bearing liposomal doxorubicin (macrophage-LP-Dox). We expect that this system could improve the cancer therapeutic efficacy through deeper penetration into tumor even hypoxic region behind tumor blood vessel. We first confirmed that macrophages containing iron oxides could migrate and infiltrate into tumors effectively by MR imaging. Next, we showed that doxorubicin (Dox) encapsulated with liposomes (LP-Dox) was successfully loaded into macrophages, in which the biological activity of macrophage and cytotoxicity of Dox against tumor cells were well preserved. Delivery of Dox into tumor tissue by systemic administration of macrophage-LP-Dox was verified in both subcutaneous and metastasis xenograft tumor models. Importantly, the effective inhibition of in vivo tumor growth was proved with this system. Our results provide the feasibility of macrophages-LP-drug as an active biocarrier for the enhancement of therapeutic effects in cancer treatment and open new perspectives for the active delivery of drugs.
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Park JS, Chung HK, Hwang HK, Kim JK, Yoon DS. Postoperative nutritional effects of early enteral feeding compared with total parental nutrition in pancreaticoduodectomy patients: a prosepective, randomized study. J Korean Med Sci 2012; 27:261-7. [PMID: 22379336 PMCID: PMC3286772 DOI: 10.3346/jkms.2012.27.3.261] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/07/2011] [Accepted: 11/01/2011] [Indexed: 12/17/2022] Open
Abstract
The benefits of early enteral feeding (EEN) have been demonstrated in gastrointestinal surgery. But, the impact of EEN has not been elucidated yet. We assessed the postoperative nutritional status of patients who had undergone pancreaticoduodenectomy (PD) according to the postoperative nutritional method and compared the clinical outcomes of two methods. A prospective randomized trial was undertaken following PD. Patients were randomly divided into two groups; the EEN group received the postoperative enteral feed and the control group received the postoperative total parenteral nutrition (TPN) management. Thirty-eight patients were included in our analyses. The first day of bowel movement and time to take a normal soft diet was significantly shorter in EEN group than in TPN group. Prealbumin and transferrin were significantly reduced on post-operative day (POD) 7 and were slowly recovered until POD 90 in the TPN group than in the EEN group. EEN group rapidly recovered weight after POD 21 whereas it was gradually decreased in TPN group until POD 90. EEN after PD is associated with preservation of weight compared with TPN and impact on recovery of digestive function after PD.
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Kim S, Youn H, Song MG, Kang JH, Chung HK, Lee DS, Chung JK. Complementary treatment of siTERT for improving the antitumor effect of TERT-specific I-131 therapy. Cancer Gene Ther 2012; 19:263-70. [PMID: 22301953 DOI: 10.1038/cgt.2011.88] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Sodium iodide symporter (NIS)-based radionuclide therapy provides an effective means of treating malignant tumors. However, it is sometimes inadequate because of limited effects on radio-resistant tumors, and thus, combination therapies with other therapeutic options have been requested to enhance its efficacy. Human telomerase reverse transcriptase (hTERT) has been reported to be involved in the progression of most cancers and also been viewed as a good candidate for targeting tumor. Application of TERT-specific radionuclide therapies using NIS gene transfer have been reported to treat TERT-positive tumors, but this approach only demonstrated tumor regression rather than eradication. As inhibiting TERT expression by introducing the hTERT-specific shRNA (siTERT) has been suggested as a therapeutic option, we investigated the complementary role of siTERT treatment after the TERT-specific I-131 therapy and its possibility as a novel anticancer therapeutic strategy. Retroviruses containing TERT promoter/NIS for TERT specific Radionuclide therapy and siTERT for TERT targeting antisense therapy were produced. Hep3B cells expressing TERT specific NIS (Hep3B-TERT/NIS) were xenografted into nude mouse and visualized with micro-SPECT/CT for monitoring NIS activity. The levels of hTERT mRNA, protein and its activity were confirmed by RT-PCR, Western blotting and Telomerase repeat amplification protocol assay. Cell proliferation was monitored by MTT assay and induced apoptosis was confirmed by Annexin-V-PI staining. Therapeutic effects of I-131 and/or siTERT were evaluated by clonogenic assay and mouse tumor model. Reduction of hTERT mRNA, protein and TERT activity by siTERT were observed in Hep3B-TERT/NIS cells. The viabilities of the infected cells were significantly decreased to 50% versus siScramble treated controls. The early apoptotic cell population was increased by siTERT. The survival rates of cells treated with siTERT or I-131 alone were 72.4±7.6% and 56.2±5.2%, respectively. However, the survival rate of cells treated with I-131 and siTERT were decreased to 22.1±2.8%. From mouse xenograft model, we also found that the siTERT gene therapy showed synergism to the radioiodine therapy for reducing tumor growth in vivo. Our Results suggested that complementary siTERT gene therapy offers a novel strategy of cancer therapy to improve the therapeutic efficacy of TERT-specific I-131.
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Lee SJ, Chung HK. Analyzing altruistic motivations in public library valuation using contingent valuation method. LIBRARY & INFORMATION SCIENCE RESEARCH 2012. [DOI: 10.1016/j.lisr.2011.05.001] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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Lee SJ, Chung HK, Jung EJ. Assessing the warm glow effect in contingent valuations for public libraries. JOURNAL OF LIBRARIANSHIP AND INFORMATION SCIENCE 2010. [DOI: 10.1177/0961000610380819] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
This article aims to present evidence of the warm glow effect in a public library setting. More specifically, it tests whether individual respondents with different values for the warm glow component report different values for their willingness to pay (WTP). The data come from a contingent valuation survey conducted on randomly selected citizens of Korea, where the respondents are asked how much they are willing to pay for public library services. Results show that there is significant difference between traditional WTP and cold WTP, concluding that the traditional WTP value is not the real economic value of the public good.
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Hoarty DJ, James SF, Brown CRD, Williams BM, Guymer T, Hill M, Morton J, Chapman D, Shepherd R, Dunn J, Brown G, Schneider M, Beiersdorfer P, Chung HK, Harris JWO, Upcraft L, Smith CC, Lee RW. High temperature, high density opacity measurements using short pulse lasers. ACTA ACUST UNITED AC 2010. [DOI: 10.1088/1742-6596/244/1/012002] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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Chung HK, Suschak J, Galmin L, Rose N, Pal R. Characterization of a SHIV162P3 variant evolved in an infected rhesus macaque with persistent plasma viremia. Virus Res 2010; 151:229-34. [PMID: 20417670 DOI: 10.1016/j.virusres.2010.04.006] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2009] [Revised: 04/14/2010] [Accepted: 04/16/2010] [Indexed: 12/30/2022]
Abstract
Typically plasma viremia is controlled in macaques challenged with R5 tropic SHIV162P3 during the chronic phase of infection. However, in a few infected animals it sustains for a prolonged period. Persistent plasma viremia in two such macaques led to a rapid decline of CD4+ T-cells in blood leading to the induction of AIDS. A viral variant from one of these animals showed sensitivity to soluble CD4 and maraviroc similar to the challenge virus. However, it exhibited reduced sensitivity to anti-gp120 antibody b12 and to sera from SHIV162P3-infected macaques or HIV-1-infected humans. Molecular sequencing of the env gene from this virus revealed multiple mutations clustering on the V1 domain of gp120. These results demonstrate that evolution of the envelope in SHIV-infected macaques may lead to the emergence of a viral variant with altered immunological characteristics.
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Lee EM, Chung HK, Livesay J, Suschak J, Finke L, Hudacik L, Galmin L, Bowen B, Markham P, Cristillo A, Pal R. Molecular methods for evaluation of virological status of nonhuman primates challenged with simian immunodeficiency or simian-human immunodeficiency viruses. J Virol Methods 2009; 163:287-94. [PMID: 19878696 DOI: 10.1016/j.jviromet.2009.10.012] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2009] [Revised: 10/13/2009] [Accepted: 10/19/2009] [Indexed: 01/23/2023]
Abstract
Nonhuman primates represent a robust model to evaluate preclinical efficacy of HIV-1 vaccine and therapeutic strategies. Plasma and tissue viral RNA as well as tissue proviral DNA load are key parameters in assessing efficacy of vaccines and therapeutics against simian immunodeficiency virus (SIV) or simian-human immunodeficiency virus (SHIV) challenge. To quantitate SIV RNA in plasma and tissues, an isothermal nucleic acid sequence-based amplification (NASBA) method using real-time detection of amplified RNA with molecular beacons was developed. This assay has accuracy and reproducibility over seven orders of magnitude and has advantages over the electrochemiluminescence-based NASBA assay described previously, both in terms of higher throughput and sensitivity. Reproducibility and accuracy were also demonstrated for a TaqMan real-time PCR assay for quantitating proviral DNA load in PBMCs and lymphoid tissues. In infected macaques, the level of plasma viremia correlated with the tissue viral RNA but not always with proviral DNA loads. Further, animals with undetectable levels of viral RNA in plasma and proviral DNA in tissues, showed no sign of seroconversion and activation of Gag-specific CD8+ or CD4+ T cells in peripheral blood. These results suggest that simultaneous application of real-time NASBA and PCR assays provides quantitative evaluation of challenge outcome in macaques.
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Chung HK, Kang B, Lee JH, Shim JY, Park S, Lee SH, Park YK, Park E, Chung N, Shin MJ. Increased arterial stiffness is associated with reduced plasma levels of beta-carotene in treated hypertensive patients with type 2 diabetes mellitus. Nutr Metab Cardiovasc Dis 2009; 19:e9-e11. [PMID: 19505810 DOI: 10.1016/j.numecd.2009.03.013] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/30/2008] [Revised: 02/22/2009] [Accepted: 03/17/2009] [Indexed: 12/12/2022]
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Pal R, Nuttall J, Galmin L, Weiss D, Chung HK, Romano J. Characterization of vaginal transmission of a simian human immunodeficiency virus (SHIV) encoding the reverse transcriptase gene from HIV-1 in Chinese rhesus macaques. Virology 2009; 386:102-8. [PMID: 19195672 DOI: 10.1016/j.virol.2009.01.002] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2008] [Revised: 11/21/2008] [Accepted: 01/02/2009] [Indexed: 11/27/2022]
Abstract
Replication competent recombinant simian-human immunodeficiency virus encoding the reverse transcriptase gene (RT SHIV) from HIV-1 was characterized for vaginal transmission in rhesus macaques. RT SHIV was shown to transmit efficiently via the vaginal route in macaques with detectable plasma viremia persisting for a year in some animals. Analyses of virus load in tissues of infected animals revealed accumulation of viral RNA in lymph nodes and spleen with levels correlating with plasma viremia. RT-SHIV was inhibited by dapivirine, nevirapine, efavirenz and tenofovir in vitro, although the effect was less pronounced with tenofovir. Virus isolated from infected animals at early and later time points had limited changes in RT sequences and exhibited similar sensitivity to RT inhibitors as the challenge virus. The vaginal transmission of RT SHIV demonstrated here suggests this virus may possibly be used in the nonhuman primate model for limited evaluation of RT inhibitors applied vaginally.
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Brown GV, Hansen SB, Träbert E, Beiersdorfer P, Widmann K, Chen H, Chung HK, Clementson JHT, Gu MF, Thorn DB. Investigation of the 2p_{32}-3d_{52} line emission of Au;{53+}-Au;{69+} for diagnosing high energy density plasmas. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2008; 77:066406. [PMID: 18643382 DOI: 10.1103/physreve.77.066406] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/05/2008] [Indexed: 05/26/2023]
Abstract
Measurements of the L -shell emission of highly charged gold ions were made under controlled laboratory conditions using the SuperEBIT electron beam ion trap, allowing detailed spectral observations of lines from Fe-like Au53+ through Ne-like Au69+ . Using atomic data from the Flexible Atomic Code, we have identified strong 3d_{52}-->2p_{32} emission features that can be used to diagnose the charge state distribution in high energy density plasmas, such as those found in the laser entrance hole of hot hohlraum radiation sources. We provide collisional-radiative calculations of the average ion charge Z as a function of temperature and density, which can be used to relate charge state distributions inferred from 3d_{52}-->2p_{32} emission features to plasma conditions, and investigate the effects of plasma density on calculated L -shell Au emission spectra.
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Chung HK. The contingent valuation method in public libraries. JOURNAL OF LIBRARIANSHIP AND INFORMATION SCIENCE 2008. [DOI: 10.1177/0961000608089343] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
This study aims to present a new model measuring the economic value of public libraries, combining the dissonance minimizing (DM) and information bias minimizing (IBM) format in the contingent valuation (CV) surveys. The possible biases which are tied to the conventional CV surveys are reviewed. An empirical study is presented to compare the model with the conventional CVM and DM +IBM format. A cost—benefit analysis is used as a tool to determine if the benefit of public libraries outweighs the cost incurred in providing the services. The study conducts a case study in a public library to demonstrate how public libraries could apply the approach to their local studies.
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Ping Y, Shepherd R, Lasinski BF, Tabak M, Chen H, Chung HK, Fournier KB, Hansen SB, Kemp A, Liedahl DA, Widmann K, Wilks SC, Rozmus W, Sherlock M. Absorption of short laser pulses on solid targets in the ultrarelativistic regime. PHYSICAL REVIEW LETTERS 2008; 100:085004. [PMID: 18352633 DOI: 10.1103/physrevlett.100.085004] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/06/2007] [Revised: 08/21/2007] [Indexed: 05/26/2023]
Abstract
We report the first direct measurements of total absorption of short laser pulses on solid targets in the ultrarelativistic regime. The data show an enhanced absorption at intensities above 10(20) W/cm(2), reaching 60% for near-normal incidence and 80%-90% for 45 degrees incidence. Two-dimensional particle-in-cell simulations demonstrate that such high absorption is consistent with both interaction with preplasma and hole boring by the intense laser pulse. A large redshift in the second harmonic indicates a surface recession velocity of 0.035c.
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Chen H, Shepherd R, Chung HK, Kemp A, Hansen SB, Wilks SC, Ping Y, Widmann K, Fournier KB, Dyer G, Faenov A, Pikuz T, Beiersdorfer P. Fast-electron-relaxation measurement for laser-solid interaction at relativistic laser intensities. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2007; 76:056402. [PMID: 18233771 DOI: 10.1103/physreve.76.056402] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/14/2007] [Revised: 09/25/2007] [Indexed: 05/25/2023]
Abstract
We present measurements of the fast-electron-relaxation time in short-pulse (0.5 ps) laser-solid interactions for laser intensities of 10(17), 10(18), and 10(19) Wcm2, using a picosecond time-resolved x-ray spectrometer and a time-integrated electron spectrometer. We find that the laser coupling to hot electrons increases as the laser intensity becomes relativistic, and that the thermalization of fast electrons occurs over time scales on the order of 10 ps at all laser intensities. The experimental data are analyzed using a combination of models that include Kalpha generation, collisional coupling, and plasma expansion.
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Chung HK, Cheon GJ, Choi CW, Kim MJ, Lee SJ, Lim SM. Comparison of Cellular Metabolic Responses of18F-FDG According to the Effect ofβ-Irradiation in p53 Wild and Deleted Cell Lines. Cancer Biother Radiopharm 2007; 22:636-43. [DOI: 10.1089/cbr.2007.331] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
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Cristillo AD, Lisziewicz J, He L, Lori F, Galmin L, Trocio JN, Unangst T, Whitman L, Hudacik L, Bakare N, Whitney S, Restrepo S, Suschak J, Ferrari MG, Chung HK, Kalyanaraman VS, Markham P, Pal R. HIV-1 prophylactic vaccine comprised of topical DermaVir prime and protein boost elicits cellular immune responses and controls pathogenic R5 SHIV162P3. Virology 2007; 366:197-211. [PMID: 17499328 DOI: 10.1016/j.virol.2007.04.012] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2007] [Revised: 03/29/2007] [Accepted: 04/11/2007] [Indexed: 11/30/2022]
Abstract
Topical DNA vaccination (DermaVir) facilitates antigen presentation to naive T cells. DermaVir immunization in mice, using HIV-1 Env and Gag, elicited cellular immune responses. Boosting with HIV-1 gp120 Env and p41 Gag augmented Th1 cytokine levels. Intramuscular DNA administration was less efficient in priming antigen-specific cytokine production and memory T cells. In rhesus macaques, DermaVir immunization induced Gag- and Env-specific Th1 and Th2 cytokines and generation of memory T cells. Boosting of DermaVir-primed serum antibody levels was noted following gp140(SHIV89.6P)/p27(SIV) immunization. Rectal challenge with pathogenic R5-tropic SHIV162P3 resulted in control of plasma viremia (4/5 animals) that was reflected in jejunum, colon and mesenteric lymph nodes. An inverse correlation was found between Gag- and Env-specific central memory T cell responses on the day of challenge and plasma viremia at set point. Overall, the topical DermaVir/protein vaccination yields central memory T cell responses and facilitates control of pathogenic SHIV infection.
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Chung HK. Evaluating Academic Journals using Impact Factor and Local Citation Score. JOURNAL OF ACADEMIC LIBRARIANSHIP 2007. [DOI: 10.1016/j.acalib.2007.01.016] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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Cheon GJ, Chung HK, Choi JA, Lee SJ, Ahn SH, Lee TS, Choi CW, Lim SM. Cellular metabolic responses of PET radiotracers to (188)Re radiation in an MCF7 cell line containing dominant-negative mutant p53. Nucl Med Biol 2007; 34:425-32. [PMID: 17499732 DOI: 10.1016/j.nucmedbio.2007.01.011] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2006] [Revised: 01/28/2007] [Accepted: 01/29/2007] [Indexed: 01/16/2023]
Abstract
UNLABELLED We investigated the relations between the cell uptakes of metabolic radiotracers and beta-radiation pretreatment using a dominant mutant p53 (p53mt) cell line to evaluate the effects of p53 genes on (18)F labeled positron emission tomography (PET) radiotracer uptakes. METHODS pCMV-Neo-Bam (control), which contains a neo-resistance marker, and p53 dominant-negative mutant expression constructs were stably transfected into MCF7 cell line. Cells were plated in 24-well plates at 1.0x10(5) cells for 18 h. Rhenium-188 ((188)Re) (a beta emitter) was added to the medium (3.7, 18.5, 37 MBq) and incubated for 24 h. We performed gamma-counting to determine the cellular uptakes of 2-[(18)F]fluoro-2-deoxy-d-glucose (FDG), o-(2-[(18)F]fluoroethyl)-l-tyrosine (FET) and 2'-[(18)F]fluoro-2'-deoxythymidine (FLT) (370 kBq, 60 min). Cell viabilities were determined by trypan blue staining and flow cytometry. RESULTS p53mt cells showed 1.5-2-fold higher FDG uptake than wild-type p53 cells in basal condition, and the difference of FDG uptake was greater after (188)Re treatment (P<.01). FET uptake increased with (188)Re dose without a significant difference between p53 statuses. p53mt cells showed lower FLT uptake than wild-type p53 cells in basal condition, and the difference of FLT uptake was greater after (188)Re treatment. By cell viability testing and FACS analysis, p53mt cells showed lower viability and a larger apoptotic fraction (sub-G1) than wild-type p53 cells after (188)Re treatment. CONCLUSION We speculate that p53 dysfunction increases glucose and decreases thymidine metabolism in cancer cells and that this may be exaggerated by (188)Re beta-radiation. Our findings suggest that FDG could reflect tumor viability and malignant potential after (188)Re beta-radiation treatment, whereas FLT could be a more useful PET radiotracer for assessing therapeutic response to beta-radiation, especially in cancer cells with an altered function of p53.
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Hansen SB, Faenov AY, Pikuz TA, Fournier KB, Shepherd R, Chen H, Widmann K, Wilks SC, Ping Y, Chung HK, Niles A, Hunter JR, Dyer G, Ditmire T. Temperature determination using Kalpha spectra from M -shell Ti ions. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2005; 72:036408. [PMID: 16241580 DOI: 10.1103/physreve.72.036408] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/25/2005] [Indexed: 05/05/2023]
Abstract
The compact multipulse terawatt (COMET) laser facility at LLNL was used to irradiate Al-coated 2-50 microm Ti foils with approximately 10(19) W cm(-2) , 500 fs, 3-6 J laser pulses. Laser-plasma interactions on the front side of the target generate hot electrons with sufficient energy to excite inner-shell electrons in Ti, creating Kalpha emission which has been measured using a focusing spectrometer with spatial resolution aimed at the back surface of the targets. The spatial extent of the emission varies with target thickness. The high spectral resolution (lambda/Deltalambda approximately equal to 3800) is sufficient to measure broadening of the Kalpha emission feature due to the emergence of blueshifted satellites from ionized Ti in a heated region of the target. A self-consistent-field model is used to spectroscopically diagnose thermal electron temperatures up to 40 eV in the strongly coupled Ti plasmas.
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