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Yi K, Mujat M, Park BH, Sun W, Miller JW, Seddon JM, Young LH, de Boer JF, Chen TC. Spectral domain optical coherence tomography for quantitative evaluation of drusen and associated structural changes in non-neovascular age-related macular degeneration. Br J Ophthalmol 2008; 93:176-81. [PMID: 18697811 PMCID: PMC2628537 DOI: 10.1136/bjo.2008.137356] [Citation(s) in RCA: 68] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Background/aims: To demonstrate how spectral domain optical coherence tomography (SDOCT) can better evaluate drusen and associated anatomical changes in eyes with non-neovascular age-related macular degeneration (AMD) compared with time domain optical coherence tomography (TDOCT). Methods: Images were obtained from three eyes of three patients with AMD using an experimental SDOCT system. Both a titanium–sapphire (Ti:sapphire) laser and a superluminescent diode (SLD) were used as a broadband light source to achieve cross-sectional images of the retina. A qualitative and quantitative analysis was performed for structural changes associated with non-neovascular AMD. An automated algorithm was developed to analyse drusen area and volume from SDOCT images. TDOCT was performed using the fast macular scan (StratusOCT, Carl Zeiss Meditec, Dublin, California). Results: SDOCT images can demonstrate structural changes associated with non-neovascular AMD. A new SDOCT algorithm can determine drusen area, drusen volume and proportion of drusen. Conclusions: With new algorithms to determine drusen area and volume and its unprecedented simultaneous ultra-high speed ultra-high resolution imaging, SDOCT can improve the evaluation of structural abnormalities in non-neovascular AMD.
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Oh WY, Yun SH, Vakoc BJ, Shishkov M, Desjardins AE, Park BH, de Boer JF, Tearney GJ, Bouma BE. High-speed polarization sensitive optical frequency domain imaging with frequency multiplexing. OPTICS EXPRESS 2008; 16:1096-103. [PMID: 18542183 PMCID: PMC2752304 DOI: 10.1364/oe.16.001096] [Citation(s) in RCA: 82] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
Polarization sensitive optical coherence tomography (PS-OCT) provides a cross-sectional image of birefringence in biological samples that is complementary in many applications to the standard reflectance-based image. Recent ex vivo studies have demonstrated that birefringence mapping enables the characterization of collagen and smooth muscle concentration and distribution in vascular tissues. Instruments capable of applying these measurements percutaneously in vivo may provide new insights into coronary atherosclerosis and acute myocardial infarction. We have developed a polarization sensitive optical frequency domain imaging (PS-OFDI) system that enables high-speed intravascular birefringence imaging through a fiber-optic catheter. The novel design of this system utilizes frequency multiplexing to simultaneously measure reflectance of two incident polarization states, overcoming concerns regarding temporal variations of the catheter fiber birefringence and spatial variations in the birefringence of the sample. We demonstrate circular cross-sectional birefringence imaging of a human coronary artery ex vivo through a flexible fiber-optic catheter with an A-line rate of 62 kHz and a ranging depth of 6.2 mm.
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Maguluri G, Mujat M, Park BH, Kim KH, Sun W, Iftimia NV, Ferguson RD, Hammer DX, Chen TC, de Boer JF. Three dimensional tracking for volumetric spectral-domain optical coherence tomography. OPTICS EXPRESS 2007; 15:16808-17. [PMID: 19550971 DOI: 10.1364/oe.15.016808] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
We present a three-dimensional (3D) tracker for a clinical ophthalmic spectral domain optical coherence tomography (SD-OCT) system that combines depth-tracking with lateral tracking, providing a stabilized reference frame for 3D data recording and post acquisition analysis. The depth-tracking system is implemented through a real-time dynamic feedback mechanism to compensate for motion artifact in the axial direction. Active monitoring of the retina and adapting the reference arm of the interferometer allowed the whole thickness of the retina to be stabilized to within +/-100 mum. We achieve a relatively constant SNR from image to image by stabilizing the image of the retina with respect to the depth dependent sensitivity of SD-OCT. The depth tracking range of our system is 5.2 mm in air and the depth is adjusted every frame.nhancement in the stability of the images with the depth-tracking algorithm is demonstrated on a healthy volunteer.
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Min JW, Kong KA, Park BH, Hong JH, Park EA, Cho SJ, Ha EH, Park H. Effect of postnatal catch-up growth on blood pressure in children at 3 years of age. J Hum Hypertens 2007; 21:868-74. [PMID: 17476289 DOI: 10.1038/sj.jhh.1002215] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Size at birth and early postnatal growth rates appear to be important determinants of cardiovascular diseases. We examined whether intrauterine growth restriction or the subsequent catch-up postnatal weight gain leads to higher blood pressure in early life to confirm that size at birth and early postnatal growth rates appear to be important determinants of blood pressure changes in early life. Of 407 children born between December 2001 and November 2002 in hospital based-birth cohorts, 102 were followed up at 3 years of age (24.2%) at Ewha Womans University Hospital in Seoul, Korea. At 3 years of age, those who had a low birth weight still belonged in the lower-weight group than the others. The subjects' systolic blood pressure was correlated with their current weight (r=0.41) and weight gain (r=0.39), but not with their birth weight. Those with a higher current weight and higher weight gain based on birth weight (conditional weight gain) had the highest blood pressure. Systolic blood pressure increased by 0.2 mm Hg for every 100-g increase in weight at 3 years and, independently, by 1.5 mm Hg for every 100-unit increase in conditional weight gain. This study suggests that birth weight is not directly associated with blood pressure, but accelerated growth, which occurs mostly in those born with a low birth weight, seems to affect blood pressure in early life.
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Cense B, Mujat M, Chen TC, Park BH, de Boer JF. Polarization-sensitive spectral-domain optical coherence tomography using a single line scan camera. OPTICS EXPRESS 2007; 15:2421-31. [PMID: 19532479 DOI: 10.1364/oe.15.002421] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Polarization-sensitive optical coherence tomography can be used to measure the birefringence of biological tissue such as the human retina. Previous measurements with a time-domain polarization-sensitive optical coherence tomography system revealed that the birefringence of the human retinal nerve fiber layer is not constant, but varies as a function of location around the optic nerve head. Here we present a spectral-domain polarization-sensitive optical coherence tomography system that uses a spectrometer configuration with a single line scan camera and a Wollaston prism in the detection arm. Since only one camera has to be synchronized with other components in the system, the design is simplified considerably. This system is 60 times faster than a time-domain polarization-sensitive optical coherence tomography system. Data was acquired using concentric circular scans around the optic nerve head of a young healthy volunteer and the acquisition time for 12 circular scans was reduced from 72 s to 1.2 s. The acquired data sets demonstrate variations in retinal thickness and double pass phase retardation per unit depth that were similar to data from the same volunteer taken with a time-domain polarization-sensitive system. The double pass phase retardation per unit depth of the retinal nerve fiber layer varied between 0.18 and 0.40 degrees/mum, equivalent to a birefringence of 2.2 * 10(-4) and 4.8 * 10(-4) respectively, measured at 840 nm.
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Park JH, Song HI, Rho JM, Kim MR, Kim JR, Park BH, Park TS, Baek HS. Parathyroid hormone (1-34) augments angiopoietin-1 expression in human osteoblast-like cells. Exp Clin Endocrinol Diabetes 2006; 114:438-43. [PMID: 17039426 DOI: 10.1055/s-2006-924400] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Abstract
Parathyroid hormone (PTH) is a major regulatory factor in skeletal physiology. However, the molecular mechanism underlying the effects of PTH on bones has yet to be elucidated in detail. Recently, some reports have demonstrated the crucial role of bone vasculature with regard to bone density. Angiopoietin-1 (Ang-1), along with VEGF, has been established as a primary angiogenic regulatory agent. In this study, we have attempted to characterize the effects of PTH (1-34) on Ang-1 expression and signaling molecules, employing primary-cultured human osteoblast-like cells. Quiescent osteoblasts were exposed to PTH (1-34), after which Ang-1 expression was determined at the mRNA and protein levels. Reverse transcription-polymerase chain reaction (RT-PCR) analyses indicated that Ang-1 mRNA expression increased as the result of PTH (1-34) treatment. The expression of the Ang-1 protein was also augmented as the result of treatment with PTH (1-34). An adenylyl cyclase activator, forskolin, was shown to induce Ang-1 mRNA expression, whereas the protein kinase A inhibitor, H-89, blocked the PTH (1-34)-mediated expression of Ang-1 mRNA. These findings indicate that PTH (1-34)-mediated Ang-1 expression involves adenylyl cyclase-protein kinase A dependent signaling. Our observations also show that Ang-1 may perform a crucial role in the effects of PTH (1-34) on bones, possibly involving alterations in bone vasculature.
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Kim JH, Oh JY, Park BH, Lee DE, Kim JS, Park HE, Roh MS, Je JE, Yoon JH, Thorne SH, Kirn D, Hwang TH. Systemic armed oncolytic and immunologic therapy for cancer with JX-594, a targeted poxvirus expressing GM-CSF. Mol Ther 2006; 14:361-70. [PMID: 16905462 DOI: 10.1016/j.ymthe.2006.05.008] [Citation(s) in RCA: 230] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2006] [Revised: 05/16/2006] [Accepted: 05/16/2006] [Indexed: 12/17/2022] Open
Abstract
Targeted oncolytic viruses and immunostimulatory therapeutics are being developed as novel cancer treatment platforms. These approaches can be combined through the expression of immunostimulatory cytokines from targeted viruses, including adenoviruses and herpesviruses. Although intratumoral injection of such viruses has been associated with tumor growth inhibition, eradication of distant metastases was not reported. The major limitations for this approach to date have been (1) inefficient intravenous virus delivery to tumors and (2) the lack of predictive, immunocompetent preclinical models. To overcome these hurdles, we developed JX-594, a targeted, thymidine kinase(-) vaccinia virus expressing human GM-CSF (hGM-CSF), for intravenous (i.v.) delivery. We evaluated two immunocompetent liver tumor models: a rabbit model with reproducible, time-dependent metastases to the lungs and a carcinogen-induced rat liver cancer model. Intravenous JX-594 was well tolerated and had highly significant efficacy, including complete responses, against intrahepatic primary tumors in both models. In addition, whereas lung metastases developed in all control rabbits, none of the i.v. JX-594-treated rabbits developed detectable metastases. Tumor-specific virus replication and gene expression, systemically detectable levels of hGM-CSF, and tumor-infiltrating CTLs were also demonstrated. JX-594 holds promise as an i.v.-delivered, targeted virotherapeutic. These two tumor models hold promise for the optimization of this approach.
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Weiss MB, Vitolo MI, Baerenfaller K, Marra G, Park BH, Bachman KE. Persistent mismatch repair deficiency following targeted correction of hMLH1. Cancer Gene Ther 2006; 14:98-104. [PMID: 17082796 DOI: 10.1038/sj.cgt.7700997] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
The use of gene therapy to correct mutated or lost gene function for the treatment of human cancers has been an active, yet problematic area of biomedical research. Many technical difficulties, including efficient tissue-specific delivery, integration site specificity and general toxicity, are being addressed. Little is known, however, about the genetic and phenotypic stability that accompanies a successful gene-specific targeting event in a cancer cell. This question was addressed following the creation of a colon cancer cell line in which a mutated hMLH1 gene was corrected via targeted homologous recombination. This correction resulted in the expression of wild-type hMLH1 protein, restoration of the hPMS2 protein and mismatch repair (MMR) proficiency. One of two hMLH1-corrected clones, however, was found to retain defects in MMR activity. These cells continued to express the corrected hMLH1 protein, but had lost expression of another MMR protein, hMSH6. DNA sequence analysis of the hMSH6 gene revealed biallelic expansions of a cytosine repeat region in exon 5 that result in frameshifts leading to premature stop codons. These findings suggest that, similar to acquired drug resistance, the presence of genetically heterogeneous cancer cell populations or acquisition of compensatory mutations can result in 'resistance' to gene replacement therapy.
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Lim H, de Boer JF, Park BH, Lee EC, Yelin R, Yun SH. Optical frequency domain imaging with a rapidly swept laser in the 815-870 nm range. OPTICS EXPRESS 2006; 14:5937-44. [PMID: 19516763 DOI: 10.1364/oe.14.005937] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/19/2023]
Abstract
Optical frequency domain imaging (OFDI) in the 800-nm biological imaging window is demonstrated by using a novel wavelength-swept laser source. The laser output is tuned continuously from 815 to 870 nm at a 43.2-kHz repetition rate with 7-mW average power. Axial resolution of 10-mum in biological tissue and peak sensitivity of 96 dB are achieved. In vivo imaging of Xenopus laevis is demonstrated with an acquisition speed of 84 frames per second (512 axial lines per frame). This new imaging technique may prove useful in comprehensive retinal screening for medical diagnosis and contrast-agent-based imaging for biological investigations.
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Karakas B, Weeraratna A, Abukhdeir A, Blair BG, Konishi H, Arena S, Becker K, Wood W, Argani P, De Marzo AM, Bachman KE, Park BH. Interleukin-1 alpha mediates the growth proliferative effects of transforming growth factor-beta in p21 null MCF-10A human mammary epithelial cells. Oncogene 2006; 25:5561-9. [PMID: 16619041 DOI: 10.1038/sj.onc.1209540] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Transforming growth factor-beta type 1 (TGF-beta) has been implicated as both a tumor suppressor and a tumor promoter in many solid epithelial cancers. We have previously demonstrated that the cyclin dependent kinase (CDK) inhibitor p21 acts as a molecular switch in determining a growth inhibitory versus growth proliferative response to TGF-beta in the spontaneously immortalized human mammary epithelial cell line MCF-10A. We now demonstrate that this proliferative effect of TGF-beta is mediated through the proinflammatory cytokine, interleukin-1alpha (IL-1alpha). Using gene expression array analysis, we identified IL-1alpha as a cytokine specifically upregulated only in cells lacking p21 and only upon TGF-beta stimulation. Cell proliferation assays verified that recombinant IL-1alpha was capable of inducing a growth proliferative response in p21 null MCF-10A cells, while neutralizing antibodies against IL-1alpha prevented the growth proliferative effects of TGF-beta. Mechanistically, both the CDK and proliferating cell nuclear antigen (PCNA) inhibitory functions of p21 were responsible for preventing TGF-beta induced cell proliferation, but only PCNA inhibition by p21 regulated IL-1alpha gene expression. These studies demonstrate a novel role for IL-1alpha in mediating a proliferative response to TGF-beta signaling, and suggest that therapies directed against IL-1alpha could abate the growth proliferative effects of TGF-beta without compromising its tumor suppressive function.
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Abstract
It is now well established that cancer is a genetic disease and that somatic mutations of oncogenes and tumour suppressor genes are the initiators of the carcinogenic process. The phosphatidylinositol 3-kinase signalling pathway has previously been implicated in tumorigenesis, and evidence over the past year suggests a pivotal role for the phosphatidylinositol 3-kinase catalytic subunit, PIK3CA, in human cancers. In this review, we analyse recent reports describing PIK3CA mutations in a variety of human malignancies, and discuss their possible implications for diagnosis and therapy.
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Cense B, Chen TC, Nassif N, Pierce MC, Yun SH, Park BH, Bouma BE, Tearney GJ, de Boer JF. Ultra-high speed and ultra-high resolution spectral-domain optical coherence tomography and optical Doppler tomography in ophthalmology. BULLETIN DE LA SOCIETE BELGE D'OPHTALMOLOGIE 2006:123-32. [PMID: 17265794] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Subscribe] [Scholar Register] [Indexed: 05/13/2023]
Abstract
We present ultra-high resolution optical coherence tomography (OCT) structural intensity and optical Doppler tomography (ODT) flow velocity images of the human retina in vivo. The ultra-high speed OCT system is based on Spectral Domain or Fourier Domain technology, which provides a sensitivity advantage over conventional OCT of more than 2 orders of magnitude. This sensitivity improvement allows video rate OCT and ODT cross sectional imaging of retinal structures. Images will be presented with axial resolutions of 6 and 3.5 microns. We observed small features in the inner and outer plexiform layers, which are believed to be small blood vessels. Flow velocity images will be presented showing pulsatile flow in retinal arteries and veins.
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Kim SK, Park IK, Park BH, Park W, Lee HS, Kim TH, Jun JB, Bae SC, Yoo DH, Uhm WS. A case report: isolated a heavy chain monoclonal gammopathy in a patient with polyneuropathy, organomegaly, endocrinopathy, monoclonal gammopathy and skin change syndrome. Int J Clin Pract 2005:26-30. [PMID: 15875614 DOI: 10.1111/j.1368-504x.2005.00343.x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
A 45-year-old South-Korean man presented with abdominal distension, progressive paresthesia and motor weakness of both lower extremities. Our case was identified as polyneuropathy, organomegaly, endocrinopathy, monoclonal gammopathy and skin change (POEMS) syndrome based on diagnostic criteria. Circulating M components of POEMS syndrome consist mainly of IgG or IgA-lambda and rarely IgM-lambda, IgG-kappa or isolated light chains. In this case, the M-band on serum protein electrophoresis and isolated IgA heavy chain on serum immunofixation electrophoresis were demonstrated, but there was no abnormal light chain. We suggest that this case may be associated with a pattern of abnormal secretion of monoclonal protein or a coincidence of a heavy chain disease in POEMS syndrome, even though the latter possibility may be very rare.
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Jhang H, Lee SG, Kim SS, Park BH, Bak JG. Stabilization of interchange modes in mirror plasmas by a nonlinear rf-plasma wave coupling process. PHYSICAL REVIEW LETTERS 2005; 95:035005. [PMID: 16090752 DOI: 10.1103/physrevlett.95.035005] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/12/2004] [Indexed: 05/03/2023]
Abstract
Experimental and theoretical studies are made of the consequences of a nonlinear coupling process between pump rf waves and interchange modes in mirror plasmas. It is demonstrated that the interchange-stable operation window exists depending on the applied rf power and gamma=omega(0)/Omega(i), where omega(0) (Omega(i)) is the angular frequency of the applied rf wave (ion cyclotron frequency). Results are shown that the nonlinear wave coupling process gives rise to the operation window near the resonance (gamma approximately equal to 1), which is elucidated by theoretical analyses combined with full rf wave simulations.
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Park JH, Park BH, Kim HK, Park TS, Baek HS. Hypoxia decreases Runx2/Cbfa1 expression in human osteoblast-like cells. Mol Cell Endocrinol 2002; 192:197-203. [PMID: 12088880 DOI: 10.1016/s0303-7207(02)00036-9] [Citation(s) in RCA: 73] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
To elucidate the molecular mechanism in relation to vascular supply and osteoporosis, we investigated the effect of hypoxia on Runx2 expression in MG63 cells. Also investigated was expression of type I collagen and osteocalcin, which are regulated by Runx2, alkaline phosphatase (ALPase) to see if they are affected by hypoxia. Quiescent cultures of MG63 cells were exposed to hypoxia (2% O(2)) and normoxia (18% O(2)) for 24, 48, 72 and 96 h. In cells exposed to hypoxia, reverse transcription-polymerase chain reaction (RT-PCR) analysis showed that mRNA expression of Runx2, type I collagen, osteocalcin, and ALPase were decreased in a time dependent manner to 96 h. Activity of ALPase was also reduced in the same manner. Western blotting showed a marked decrease in Runx2 protein at 96 h in cells under hypoxia compared to normoxia. These data indicate that Runx2 expression in osteoblasts is reduced by hypoxia, and may be a mechanism of osteoporosis by decreased vascular supply.
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Kwon KB, Yang JY, Ryu DG, Rho HW, Kim JS, Park JW, Kim HR, Park BH. Vibrio vulnificus cytolysin induces superoxide anion-initiated apoptotic signaling pathway in human ECV304 cells. J Biol Chem 2001; 276:47518-23. [PMID: 11591724 DOI: 10.1074/jbc.m108645200] [Citation(s) in RCA: 56] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Previous studies showed that exposure to Vibrio vulnificus cytolysin (VVC) caused characteristic morphologic changes and dysfunction of vascular structures in lung. VVC showed cytotoxicity for mammalian cells in culture and acted as a vascular permeability factor. In this study, the underlying mechanisms of VVC-induced cytotoxicity was investigated on ECV304 cell, a human vascular endothelial cell line. When cells were exposed to 0.4 hemolytic units (HU) of VVC, consecutive apoptotic events were observed; the elevation of superoxide anion (O (-.)(2)), the release of cytochrome c, the activation of caspase-3, the cleavage of poly(ADP-ribose) polymerase, and the DNA fragmentation. The pretreatment with 4-hydroxy-2,2,6,6-tetramethylpiperidine-N-oxyl (TEMPO), O(-.) 2) scavenger, completely abolished O(-.)(2) levels and downstream apoptotic events. Moreover, pretreatment with cyclosporin A (CsA), a mitochondrial permeability transition inhibitor, was capable of attenuating O(-.)(2)-mediated cytochrome c release and caspase-3 activation, and consequent apoptosis. Apoptosis, as demonstrated by oligonucleosomal DNA fragmentation and fluorescence microscopy, was induced 24 h after VVC treatment, which was also prevented by caspase-3 inhibitor, Ac-DEVD-CHO. Caspase-1 inhibitor, Ac-YVAD-CHO, did not protect ECV 304 cells from apoptosis. These results suggest a scenario where VVC-induced apoptosis is triggered by the generation of O(-.)(2), release of cytochrome c from mitochondria, activation of caspase-3, degradation of poly(ADP-ribose) polymerase, and DNA fragmentation. The induction of apoptosis in endothelial cells by VVC may provide a pivotal mechanism for understanding the pathophysiology of septicemia.
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Park BH, Saxer C, Srinivas SM, Nelson JS, de Boer JF. In vivo burn depth determination by high-speed fiber-based polarization sensitive optical coherence tomography. JOURNAL OF BIOMEDICAL OPTICS 2001; 6:474-9. [PMID: 11728208 DOI: 10.1117/1.1413208] [Citation(s) in RCA: 117] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/15/2001] [Revised: 05/31/2001] [Accepted: 06/28/2001] [Indexed: 05/19/2023]
Abstract
We report the first application of high-speed fiber-based polarization sensitive optical coherence tomography (PS-OCT) to image burned tissue in vivo. Thermal injury denatures collagen in skin and PS-OCT can measure the reduction in collagen birefringence using depth resolved changes in the polarization state of light propagated in, and reflected from, the tissue. Stokes vectors were calculated for each point in a scan and birefringence relative to incident polarization determined using four incident polarization states. Using a high-speed fiber-based PS-OCT system on rat skin burned for varying periods of time, a correlation between birefringence and actual burn depth determined by histological analysis was established. In conclusion, PS-OCT has potential use for noninvasive assessment of burn depth.
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Park BH, Park JW. The protective effect of Amomum xanthoides extract against alloxan-induced diabetes through the suppression of NFkappaB activation. Exp Mol Med 2001; 33:64-8. [PMID: 11460883 DOI: 10.1038/emm.2001.12] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
This study was undertaken to investigate the preventive mechanism of Amomum xanthoides extract against the development of alloxan-induced diabetics of mice. Pretreatment of mice with A. xanthoides extract via intraperitoneum prevented alloxan-induced hyperglycemia and hypoinsulinemia in a dose dependent manner. Histological examination of pancreatic tissue from A. xanthoides extract treated mice showed that the islet cells remain unaffected by alloxan treatment. NFkappaB activation in the pancreas 30 min after alloxan injection (60 mg/kg, iv), as assessed by an electrophoretic mobility shift assay, was not detected in the mice pretreated with A. xanthoides extract. These results suggest that NFkappaB activation may be one of the critical determinant in the progression of the disease. Considering the preventive effect of A. xanthoides extract from alloxan-induced diabetics development, these results may provide the possible therapeutic value of A. xanthoides extract for the prevention of diabetes mellitus progression.
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Hamm JK, Park BH, Farmer SR. A role for C/EBPbeta in regulating peroxisome proliferator-activated receptor gamma activity during adipogenesis in 3T3-L1 preadipocytes. J Biol Chem 2001; 276:18464-71. [PMID: 11279134 DOI: 10.1074/jbc.m100797200] [Citation(s) in RCA: 217] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
The differentiation of 3T3-L1 preadipocytes is regulated in part by a cascade of transcriptional events involving activation of the CCAAT/enhancer-binding proteins (C/EBPs) and peroxisome proliferator-activated receptor gamma (PPARgamma) by dexamethasone (DEX), 3-isobutyl-1-methylxanthine (MIX), and insulin. In this study, we demonstrate that exposure of 3T3-L1 preadipocytes to DEX and insulin fails to induce adipogenesis as indicated by a lack of C/EBPalpha, PPARgamma2, and adipose protein 2/fatty acid-binding protein expression; however, PPARgamma1 is expressed. Treatment of these MIX-deficient cells with a PPARgamma ligand, troglitazone, induces C/EBPalpha expression and rescues the block in adipogenesis. In this regard, we also show that induction of C/EBPalpha gene expression by troglitazone in C3H10T1/2 cells ectopically expressing PPARgamma occurs in the absence of ongoing protein synthesis, suggesting a direct transactivation of the C/EBPalpha gene by PPARgamma. Furthermore, ectopic expression of a dominant negative isoform of C/EBPbeta (liver-enriched transcriptional inhibitory protein (LIP)) inhibits the induction of C/EBPalpha, PPARgamma2, and adipose protein 2/fatty acid-binding protein by DEX, MIX, and insulin in 3T3-L1 cells without affecting the induction of PPARgamma1 by DEX. Exposure of LIP-expressing preadipocytes to troglitazone along with DEX, MIX, and insulin induces differentiation into adipocytes. Additionally, we show that sustained expression of C/EBPalpha in these LIP-expressing adipocytes requires constant exposure to troglitazone. Taken together, these observations suggest that inhibition of C/EBPbeta activity not only blocks C/EBPalpha and PPARgamma2 expression, but it also renders the preadipocytes dependent on an exogenous PPARgamma ligand for their differentiation into adipocytes. We propose, therefore, an additional role for C/EBPbeta in regulating PPARgamma activity during adipogenesis, and we suggest an alternative means of inducing preadipocyte differentiation that relies on the dexamethasone-associated induction of PPARgamma1 expression.
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Won JY, Lee DY, Shim WH, Chang BC, Park SI, Yoon CS, Kwon HM, Park BH, Jung GS. Elective endovascular treatment of descending thoracic aortic aneurysms and chronic dissections with stent-grafts. J Vasc Interv Radiol 2001; 12:575-82. [PMID: 11340135 DOI: 10.1016/s1051-0443(07)61478-x] [Citation(s) in RCA: 62] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022] Open
Abstract
PURPOSE To report our experience of endovascular stent-graft placement in patients with descending thoracic aortic dissections and aneurysms and to evaluate the feasibility, safety, and clinical outcomes of the treatment. MATERIALS AND METHODS Stent-grafts were placed in the descending thoracic aortas of 23 patients with saccular aneurysms (n = 11) and Stanford type B chronic aortic dissections of the descending thoracic and abdominal aorta (n = 12). All stent-grafts were individually constructed of self-expandable stainless steel stents covered with polytetrafluoroethylene. Vascular access was achieved through the femoral artery in all patients. Clinical status of each patient was monitored and postoperative CT was performed within 1 month of the procedure and at 3-12-month intervals after the procedures. RESULTS Successful exclusion of the primary entry tears of dissections and the inlets of saccular aneurysms was achieved in all but two patients with aortic dissection. The overall technical success rate was 91.3% (dissection: 10 of 12 = 83%; aneurysm: 11 of 11 = 100%). All patients in whom technical success was achieved showed complete thrombosis and significant decrease in diameter of the thoracic false lumen (preoperative: 5.3 cm +/- 0.9; postoperative: 4.3 cm +/- 0.9; P = .004) or aneurysm sac (preoperative: 5.3 cm +/- 1.7; postoperative: 2.8 cm +/- 2.5; P = .001). In addition, five patients demonstrated complete resolution of the dissected thoracic false lumen (n = 2) and aneurysm sac (n = 3). However, in all patients with aortic dissection, the abdominal aorta was not significantly changed in size (P = .302) and shape and their false lumen flows remained persistent. Immediate postoperative complications were detected in 12 patients (52%); 10 had fever, leukocytosis, and elevation of C-reactive protein, another had wound infection, and another had transient abdominal pain. Three patients died 2, 3, and 12 months after the procedure: one from septic shock, another from underlying mediastinitis, and the other from an unexplained cause. The remaining 20 patients were well after the procedure (1-9 days; mean, 3 days), without any stent-graft-related complications or discomfort (follow up period: 10-65 mo; mean: 25.1 mo +/- 15.6). The cumulative survival rate after the stent graft was 100% at 30 days and 91% at 12 months. CONCLUSIONS For treatment of aortic dissection and saccular aneurysm of the descending thoracic aorta, endovascular stent-graft repair may be a technically feasible and effective treatment modality.
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71
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Cho KH, Lee DC, Chhem RK, Kim SD, Bouffard JA, Cardinal E, Park BH. Normal and acutely torn posterior cruciate ligament of the knee at US evaluation: preliminary experience. Radiology 2001; 219:375-80. [PMID: 11323460 DOI: 10.1148/radiology.219.2.r01ma22375] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
PURPOSE To determine the ultrasonographic (US) findings of normal and acutely torn posterior cruciate ligament (PCL) of the knee and evaluate the usefulness of US in the injured PCL. MATERIALS AND METHODS US images were obtained in 30 knees in 15 asymptomatic volunteers as a control group and in 35 patients clinically suspected of having an acute PCL injury. Only the distal half of the PCL was evaluated. Of the 35 patients, 28 had their PCL status confirmed: 13 had a normal PCL at magnetic resonance (MR) imaging plus clinical examination, and 15 had a torn PCL at either MR imaging and surgery or MR imaging and clinical follow-up. RESULTS Normal PCLs were homogeneously hypoechoic, with a well-defined posterior border. Torn PCLs were heterogeneously hypoechoic (12 [80%] of 15 patients), with an indistinct posterior margin (11 [73%] of 15 patients). Torn PCLs were significantly thicker (range, 12.0-20.0 mm; mean, 15.6 mm +/- 2.5 [SD]; P <.01), as compared with normal PCLs in 13 patients (range, 3.8-5.8 mm; mean, 4.6 mm +/- 1.0; P <.01) and in the volunteers (range, 3.7-6.2 mm; mean, 4.5 mm +/- 1.2; P <.01). CONCLUSION An acutely torn PCL thickens (>10 mm), loses its sharply defined posterior border, and has a heterogeneously hypoechoic appearance. US may be useful as a screening examination for patients suspected of having PCL injury and for deciding whether to perform more expensive MR imaging or surgical intervention.
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72
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Seo SB, Park SJ, Park ST, Cho CC, Park BH, Lee SJ, Kim HM, Kajiuchi T, Shin TY. Disodium cromoglycate inhibits production of immunoglobulin E. Immunopharmacol Immunotoxicol 2001; 23:229-37. [PMID: 11417850 DOI: 10.1081/iph-100103862] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
Disodium cromoglycate (DSCG) has been shown to inhibit the release of mediators from mast cells. In the present study, the effect of DSCG on active anaphylactic reaction was studied in mice. DSCG dose-dependently inhibited the active systemic anaphylactic reaction and serum immunoglobulin (Ig)E production induced by immunization with ovalbumin, Bordetella pertussis toxin and aluminum hydroxide gel. DSCG strongly inhibited IL-4-dependent IgE production by lipopolysaccharide-stimulated murine whole spleen cells. In the case of U266 human IgE-bearing B cells, DSCG also showed an inhibitory effect on the IgE production. These results suggest that DSCG has an anti-anaphylactic activity by inhibition of IgE production from B cells.
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An NH, Han MK, Um C, Park BH, Park BJ, Kim HK, Kim UH. Significance of ecto-cyclase activity of CD38 in insulin secretion of mouse pancreatic islet cells. Biochem Biophys Res Commun 2001; 282:781-6. [PMID: 11401531 DOI: 10.1006/bbrc.2001.4654] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Cyclic ADP-ribose (cADPR), a product of CD38, has a second messenger role for in intracellular Ca(2+) mobilization from microsomes of pancreatic islets as well as from a variety of other cells. ADP-ribosylation of CD38 by ecto-mono ADP-ribosyltransferase in activated T cells results in apoptosis as well as inactivation of its activities. We, therefore, examined the effect of ADP-ribosylation of CD38 in mouse pancreatic islet cells. NAD-dependent inactivation and ADP-ribosylation of CD38, intracellular concentrations of cADPR and Ca(2+), and insulin secretion were measured following incubation of mouse pancreatic islet cells with NAD. ADP-ribosylation of CD38 inactivated its ecto-enzyme activities, and abolished glucose-induced increase of cADPR production, intracellular concentration of Ca(2+), and insulin secretion. Taken together, ecto-cyclase activity of CD38 to produce intracellular cADPR seems to be indispensable for insulin secretion.
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Huang ES, Samudrala R, Park BH. Scoring functions for ab initio protein structure prediction. Methods Mol Biol 2001; 143:223-45. [PMID: 11084908 DOI: 10.1385/1-59259-368-2:223] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/18/2023]
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75
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Chae MR, Park BH, Kim JS, Rho HW, Park JW, Kim HR. Protective effect of C-reactive protein against the lethality induced by Vibrio vulnificus lipopolysaccharide. Microbiol Immunol 2001; 44:335-40. [PMID: 10888350 DOI: 10.1111/j.1348-0421.2000.tb02503.x] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Vibrio vulnificus infection has attracted special interest because of its high mortality. A strong clinical association exists between hepatic dysfunction and increased morbidity and mortality from V. vulnificus infection. In this study, the effect of C-reactive protein (CRP), a typical hepatogenic acute phase protein, on the lethality induced by V. vulnificus lipopolysaccharide (LPS) was investigated in galactosamine-sensitized mice. The pretreatment of CRP, in a dose of at least 2 mg/kg, 2 hr before the challenge of LPS completely protected mice against the lethality by V. vulnificus LPS. The elevation of serum tumor necrosis factor-alpha (TNF-alpha) induced by LPS administration was not affected by CRP pretreatment. However, the LPS- or TNF-alpha-induced hepatotoxicity was completely prevented by CRP. These results indicate that CRP does not prevent the synthesis, but prevents the hepatotoxic action of TNF-alpha. The possibility that impaired production of acute phase proteins in patients with pre-existing hepatic dysfunction may predispose the higher risk of V. vulnificus infection needs to be evaluated further.
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