76
|
She WL, Chan CW, Lee WK. Dark and bright photovoltaic spatial solitons in photorefractive crystals with positive refractive-index perturbation. OPTICS LETTERS 2001; 26:1093-1095. [PMID: 18049530 DOI: 10.1364/ol.26.001093] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
We have demonstrated, for what is believed to be the first time, that in a photorefractive crystal with positive refractive-index perturbation a two-dimensional dark or bright photovoltaic spatial soliton can be formed in the same crystal by a signal beam and a background beam of different wavelengths. We discuss the conditions on the effective Glass constants and the absorption coefficients of the background and signal beams in determining the formation of the spatial soliton.
Collapse
|
77
|
Son Y, Hwang JW, Kim ZS, Lee WK, Kim JS. Allometry and biomass of Korean pine (Pinus koraiensis) in central Korea. BIORESOURCE TECHNOLOGY 2001; 78:251-255. [PMID: 11341684 DOI: 10.1016/s0960-8524(01)00012-8] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Aboveground tree biomass of Korean pine (Pinus koraiensis Sieb. et Zucc.) was determined for a natural forest of Korean pine and mixed deciduous trees and seven age classes of plantation forests in central Korea. Regression analyses of the dry weights of stem wood, stem bark, branches, and needles versus diameter at breast height were used to calculate regression equations of the form of log Y = a + b log X. Biomass of Korean pine in the mixed forest was 118 Mg ha(-1), and biomass in the plantations was linearly related to stand age, ranging from 52.3 Mg ha(-1) in 11 to 20-year-old stands to 317.9 Mg ha(-1) in 71 to 80-year-old stands. The proportions of stem wood and stem bark in the total aboveground biomass decreased with stand age while those of branch and needle increased. Specific leaf area of Korean pine ranging from 35.2 to 52.1 cm2 g(-1) was significantly different among crown positions and needle ages; in general, lower crown position and current needles had the greatest surface area per unit dry weight.
Collapse
|
78
|
Yang SW, Lee WK, Lee EJ, Kim KY, Lim Y, Lee KH, Rha HK, Hahn TW. Effect of bradykinin on cultured bovine corneal endothelial cells. Ophthalmologica 2001; 215:303-8. [PMID: 11399940 DOI: 10.1159/000050879] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
PURPOSE To clarify the effect of bradykinin on cytosolic free calcium mobilization and cell proliferation in cultured bovine corneal endothelial cells (BCEC). METHODS The cytosolic free calcium concentration (Ca2+]i) was measured with the InCa(TM) Imaging System after the treatment of bradykinin (10(-11) to 10(-7) M) alone or with the pretreatments of EGTA, bradykinin receptor (Bk1 and Bk2) antagonists and an inhibition of phospholipase C (U-73122). Also, the effect of bradykinin on cell proliferation in BCEC was evaluated using cell counts. RESULTS In BCEC, [Ca2+]i in the resting state was 87 +/- 9 nM. Bradykinin induced an increment of [Ca2+]i in a concentration-dependent manner and its 50% effective concentration was approximately 5 x 10(-11) M. A [Ca2+]i increment at 10(-8) M bradykinin was inhibited with the pretreatment of EGTA, an extracellular calcium chelator. U-73122 (5 x 10(-6) M) attenuated the bradykinin-induced [Ca2+]i increment. The pretreatment of HOE-140 (Bk2 antagonist) almost attenuated the bradykinin (10(-8) M)-induced [Ca2+]i increase, but des-Arg9-[Leu(8)]-bradykinin (Bk1 antagonist) did not suppress it. To investigate the physiological effect of bradykinin, the effect of bradykinin on cell proliferation was studied. 10(-8) M of bradykinin produced a significant increase in cell numbers. This mitogenic effect of bradykinin was inhibited by the Bk2 antagonist. CONCLUSIONS Bradykinin-induced stimulation of the signal transduction pathway in BCEC is coupled with the Bk2 type receptor. Furthermore, bradykinin produces the mitogenic effect in BCEC.
Collapse
|
79
|
Park JI, Park HJ, Choi HS, Lee K, Lee WK, Chun SY. Gonadotropin regulation of NGFI-B messenger ribonucleic acid expression during ovarian follicle development in the rat. Endocrinology 2001; 142:3051-9. [PMID: 11416027 DOI: 10.1210/endo.142.7.8232] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
NGFI-B is an immediate-early gene that encodes an orphan nuclear receptor. The present study was designed to examine the localization and gonadotropin regulation of NGFI-B expression in the rat ovary. Northern blot analysis of ovaries obtained from prepubertal rats revealed the increased expression of NGFI-B during prepubertal development. Treatment of immature rats with PMSG, however, decreased ovarian NGFI-B expression. The major cell types expressing NGFI-B messenger RNA were thecal cells of follicles in different sizes. In contrast, treatment of PMSG-primed rats with human (h) CG resulted in the rapid and transient stimulation of ovarian NGFI-B messenger RNA, reaching a peak within 1 h. In situ hybridization analysis revealed that hCG treatment induced the expression of NGFI-B in granulosa cells of preovulatory follicles. Treatment of cultured preovulatory follicles in vitro with LH further confirmed the time- and dose-dependent stimulation of NGFI-B messenger RNA and protein. LH-stimulated NGFI-B expression in preovulatory follicles was abolished by alpha-amanitin, but was superinduced by cycloheximide. Furthermore, treatment of adult cycling rats with pentobarbital abolished NGFI-B expression on proestrus, and exogenous administration of hCG restored it, indicating the role of the preovulatory surge of LH in the stimulation of NGFI-B expression. These results demonstrate the cell type-specific expression and gonadotropin induction of NGFI-B in granulosa cells of preovulatory follicles and suggest a role for NGFI-B in the ovulatory process.
Collapse
|
80
|
Lee WK, Park KD, Kim YH, Suh H, Park JC, Lee JE, Sun K, Baek MJ, Kim HM, Kim SH. Improved calcification resistance and biocompatibility of tissue patch grafted with sulfonated PEO or heparin after glutaraldehyde fixation. JOURNAL OF BIOMEDICAL MATERIALS RESEARCH 2001; 58:27-35. [PMID: 11152994 DOI: 10.1002/1097-4636(2001)58:1<27::aid-jbm40>3.0.co;2-2] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
A novel chemical modification of biological tissues was developed aimed at improving biocompatibility and calcification resistance. This method involved the additional grafting of sulfonated PEO (PEO-SO(3)) or heparin after conventional glutaraldehyde (GA) fixation of bovine pericardium (BP). The amino groups of PEO-SO(3) or heparin were utilized to react to the GA residues to block them. The PEO-SO(3) or heparin grafted tissues demonstrated a slightly higher shrinkage temperature and tensile strength, but greater resistance to collagenase digestion, than GA treated ones. These results suggest that modified tissues have improved durability due to the grafting and filling effect of PEO-SO(3) or heparin in addition to the GA cross-linking. At the direct contact cytotoxicity test in vitro, PEO-SO(3) or heparin grafted tissue was shown to be nontoxic, while relatively significant cytotoxicity was observed for the GA treated tissues, possibly due to the release of GA. From the in vivo calcification study, calcium contents deposited on the modified tissues were much less than those on GA treated tissues. Such a decreased calcification might be explained by the decrease of residual GA groups during the additional treatment, and the space-filling effect and the nonadhesive property and/or the blood compatibility of PEO-SO(3) or heparin grafted covalently. The newly modified tissue patch was observed to show improved pathological assessibility including less inflammation and tissue reactions. This simple modification method may be useful for calcification-resistant and blood-compatible tissue patches for cardiovascular implants.
Collapse
|
81
|
Lee M, Cho BK, Ihn KJ, Lee WK, Oh NK, Zin WC. Supramolecular honeycomb by self-assembly of molecular rods in rod-coil molecule. J Am Chem Soc 2001; 123:4647-8. [PMID: 11457270 DOI: 10.1021/ja004071+] [Citation(s) in RCA: 75] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
|
82
|
Kim WU, Seo YI, Park SH, Lee WK, Lee SK, Paek SI, Cho CS, Song HH, Kim HY. Treatment with cyclosporin switching to hydroxychloroquine in patients with rheumatoid arthritis. Ann Rheum Dis 2001; 60:514-7. [PMID: 11302876 PMCID: PMC1753640 DOI: 10.1136/ard.60.5.514] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
OBJECTIVE To investigate the therapeutic benefit of cyclosporin A (CSA) switching to hydroxychloroquine (HCQ) in patients with rheumatoid arthritis (RA). METHODS Thirty four patients with RA who displayed residual inflammation and disability despite partial responses to prior maximal tolerated doses of methotrexate, were included. All were treated with a staged approach using CSA for 24 weeks to induce clinical improvement, followed by HCQ for 16 weeks to maintain the improvement. Seven ACR core set measures were evaluated every four to eight weeks. RESULTS During a 40 week open trial, 27/34 patients completed the study. CSA treatment significantly reduced the tender joints score, swollen joints score, visual analogue pain scale, patient's or doctor's global assessment, patient's self assessed disability, and C reactive protein. Compared with the time of entry into the trial, patients who switched from CSA to HCQ still possessed significantly lower levels of most variables, determined at 28, 32, and 40 weeks. According to the ACR 20% improvement definition, 15/27 (56%) patients had improved at 24 weeks after CSA treatment, and 14/27 (52%) remained improved at 16 weeks after the change to HCQ. Frequent side effects, such as hypertrichosis, gastrointestinal trouble, and hypertension, were noted during CSA treatment, but most of these disappeared after switching to HCQ. The mean levels of blood pressure and serum creatinine were significantly increased during CSA treatment, but returned to normal after changing to HCQ. CONCLUSIONS The data suggest that CSA switching to HCQ treatment may be an effective strategy for patients with RA partially responding to methotrexate, particularly those with toxicity due to CSA.
Collapse
|
83
|
Szeto ML, Lee CK, Yee YK, Li KF, Lee WK, Lee CC, Que TL, Wong BC. Evaluation of five commercial serological tests for the detection of Helicobacter pylori infection in Chinese. Aliment Pharmacol Ther 2001; 15:703-6. [PMID: 11328265 DOI: 10.1046/j.1365-2036.2001.00961.x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
BACKGROUND Commercial serological tests for the detection of Helicobacter pylori infection must be locally validated. We evaluated the accuracy of five commercial tests in the Chinese population. METHODS Serum samples were collected from patients referred for upper endoscopy. Antral biopsies were taken for histological examination and culture of H. pylori. The gold standard for diagnosing H. pylori infection was positive histological staining and/or positive H. pylori culture. The serum samples were tested for H. pylori antibodies using the following tests: (i) Cobas Core Anti-H. pylori EIA; (ii) GAP IgG; (iii) GAP IgM; (iv) H. pylori microwell EIA (Quidel); and (v) Premier H. pylori. The sensitivity, specificity and accuracy of each test was calculated according to the manufacturers' instructions or according to a new cut-off value. RESULTS A total of 158 patients were recruited amongst whom 114 (72%) were H. pylori-positive. Indeterminate results varied from 7% to 19%. The accuracy of the tests varied from 57% to 85%. By using new cut-off values, the accuracy was much improved, ranging from 73.4% to 86.7%. CONCLUSIONS By defining new cut-off values for the Chinese population, we were able to improve the performance of some of the serology tests. This illustrates the importance of local validation.
Collapse
|
84
|
To KF, Chan PK, Chan KF, Lee WK, Lam WY, Wong KF, Tang NL, Tsang DN, Sung RY, Buckley TA, Tam JS, Cheng AF. Pathology of fatal human infection associated with avian influenza A H5N1 virus. J Med Virol 2001; 63:242-6. [PMID: 11170064 DOI: 10.1002/1096-9071(200103)63:3<242::aid-jmv1007>3.0.co;2-n] [Citation(s) in RCA: 316] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Eighteen cases of human influenza A H5N1 infection were identified in Hong Kong from May to December 1997. Two of the six fatal cases had undergone a full post-mortem which showed reactive hemophagocytic syndrome as the most prominent feature. Other findings included organizing diffuse alveolar damage with interstitial fibrosis, extensive hepatic central lobular necrosis, acute renal tubular necrosis and lymphoid depletion. Elevation of soluble interleukin-2 receptor, interleukin-6 and interferon-gamma was demonstrated in both patients, whereas secondary bacterial pneumonia was not observed. Virus detection using isolation, reverse transcription-polymerase chain reaction and immunostaining were all negative. It is postulated that in fatal human infections with this avian subtype, initial virus replication in the respiratory tract triggers hypercytokinemia complicated by the reactive hemophagocytic syndrome. These findings suggest that the pathogenesis of influenza A H5N1 infection might be different from that of the usual human subtypes H1-H3.
Collapse
|
85
|
Chu WP, Que TL, Lee WK, Wong SN. Meningoencephalitis caused by Bacillus cereus in a neonate. Hong Kong Med J 2001; 7:89-92. [PMID: 11406681] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/20/2023] Open
Abstract
We report on a newborn boy, who was delivered at 26 weeks' gestation by emergency caesarean section because of a prolapsed cord and breech presentation. Grade IV hyaline membrane disease subsequently developed, for which a surfactant was given. On day 8, there were frequent apnoeic attacks, and on day 30, marked irritability developed, as did intermittent stiffening of all four limbs. The anterior fontanelle was bulging and tense, and the cerebrospinal fluid was found to be turbid. Gram staining of the cerebrospinal fluid and blood revealed Gram-positive bacilli. Subsequent culturing yielded Bacillus cereus, which was sensitive to amikacin and vancomycin. Severe cerebral oedema developed, however, and computed tomography of the brain showed bright cortical sulci, suggestive of meningitis. The baby died on day 37, and post-mortem histological examination of the brain showed extensive liquefactive necrosis with abundant neutrophilic infiltration. Since infection with Bacillus cereus is rapidly fatal, early recognition of infection by this organism is important.
Collapse
|
86
|
Suh CH, Jeong YS, Park HC, Lee CH, Lee J, Song CH, Lee WK, Park YB, Song J, Lee SK. Risk factors for infection and role of C-reactive protein in Korean patients with systemic lupus erythematosus. Clin Exp Rheumatol 2001; 19:191-4. [PMID: 11326483] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/19/2023]
Abstract
To evaluate risk factors for infection and the role of C-reactive protein (CRP) in the diagnosis of infection, a retrospective case control study was performed among Korean systemic lupus erythematosus patients. Of 120 proven infections, 31 episodes (25.8%) occurred in patients taking no corticosteroids (CS). The risk of infection was lower in patients taking low-dose CS (< 300 mg prednisolone/month) than no CS (odds ratio (OR) 0.36). In patients receiving high-dose CS (> 1000 mg prednisolone/month), however, the risk increased (OR 2.9). In patients taking no CS, disease activity manifested as increased SLEDAI, anemia and active urinary sediment, was associated with infection. The CRP was higher in the patients with infection than controls and the CRP levels over 50 mg/l were observed only in infection. These results suggest that CS have a bimodal influence on infection depending on dose. Disease activity is an important risk factor for infection in patients taking no CS. Finally, CRP levels greater than 50 mg/l suggest the presence of infection.
Collapse
|
87
|
Lee WK, Choi SW, Lee HR, Lee EJ, Lee KH, Kim HO. Purinoceptor-mediated calcium mobilization and proliferation in HaCaT keratinocytes. J Dermatol Sci 2001; 25:97-105. [PMID: 11164706 DOI: 10.1016/s0923-1811(00)00117-1] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
To investigate the effect of nucleotides on cytosolic free calcium mobilization and proliferation activity in HaCaT keratinocytes, nucleotides-induced intracellular free calcium concentration ([Ca(2+)](i)) and cell proliferation observed. [Ca(2+)](i) to the extracellular nucleotides was determined using Ca(2+) sensitive indicator, Fura-2/AM with digital video fluorescence imaging microscopy, and cell proliferation was evaluated by counting of cell number. An adenosine 5'-triphosphate (ATP)-induced [Ca(2+)](i) increase was observed from the concentration of 10(-8) M and was more conspicuous at higher concentrations in a concentration-dependent manner. Additionally, other nucleotides such as ADP, UTP, and 2-me-S-ATP also induced a [Ca(2+)](i) increase in a concentration-dependent manner. However, adenosine induced a slight increase of [Ca(2+)](i) only at 10(-3) M. alpha,-methylene-ATP did not evoke any rise in [Ca(2+)](i). The maximal response observed occurred with ATP and UTP at a concentration of 10(-4) M. The ATP-induced transient [Ca(2+)](i) increase was attenuated by the pretreatment with phospholipase C (PLC) inhibitor, U-73122 (10 microM) for 30 min. ATP-induced [Ca(2+)](i) increase and cell proliferation were inhibited by putative P2Y receptor antagonist, suramin (10(-4) M). When the HaCaT cells were stimulated with nucleotides on a concentration of 10(-4) M and cultured for 5 days, the order of effect on cell proliferation was observed to be ATP>UTP>ADP>2-me-S-ATP. Based on these results, we suggest that extracellular ATP stimulate HaCaT keratinocytes proliferation via purinoceptor-mediated [Ca(2+)](i) mobilization
Collapse
|
88
|
Kim KA, Lee WK, Kim JK, Seo MS, Lim Y, Lee KH, Chae G, Lee SH, Chung Y. Mechanism of refractory ceramic fiber- and rock wool-induced cytotoxicity in alveolar macrophages. Int Arch Occup Environ Health 2001; 74:9-15. [PMID: 11196086 DOI: 10.1007/s004200000187] [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: 11/27/2022]
Abstract
OBJECTIVES Man-made vitreous fibers (MMVFs) can induce cytotoxicity in a way similar to that of other particles, including silica and asbestos fibers. However, as yet the mechanism of MMVF-induced cytotoxicity is still not clear. This report aims to clarify the mechanism of MMVF-induced cytotoxicity in the alveolar macrophage (AM). In this mechanism, an attempt to prove the involvement of the adenosine triphosphate (ATP) generation system and the polyinosinic acid-inhibitable scavenger receptors was made. METHODS Several parameters were observed for cytotoxicity, such as cell viability, the release of lactic dehydrogenase (LDH) and ATP levels in rat AM's that were treated with refractory ceramic fibers (RF2) and rock wool (RW1). A specially designed ATP generation system was used to determine the effect of MMVF on ATP generation. A scavenger receptor ligand was applied to evaluate the relationship between scavenger receptors and MMVF-induced ATP depletion. RESULTS A 3-(4,5-dimethylthiazol)-2,5-diphenyl tetrazolium bromide (MTT) assay indicated that both RF2 and RW1 caused a decrease in cell viability and this decrease was concentration-dependent. RF2 and RW1 increased the release of LDH with increasing fiber concentration. From these parameters, RF2 was shown to exhibit greater cytotoxicity than did RW1. Both fibers decreased the intracellular ATP content and this decrease was concentration-dependent. The decrease was more pronounced in RW1 than in RF2 at all fiber concentrations. These fibers suppressed succinate-triggered oxygen consumption. Polyinosinic acid, a ligand of the scavenger receptor, inhibited the MMVF-induced decrease in ATP concentration. CONCLUSION These results suggest that RF2 and RW1 can induce cytotoxicity and ATP depletion in the AM through the polyinosinic acid-inhibitable scavenger receptor. ATP depletion was the important factor in MMVF cytotoxicity, especially by RW1.
Collapse
|
89
|
Lee WK, Fezzaa K, Fernandez P, Tajiri G, Mills D. Performance limits of indirectly cryogenically cooled silicon monochromators--experimental results at the APS. JOURNAL OF SYNCHROTRON RADIATION 2001; 8:22-25. [PMID: 11486492 DOI: 10.1107/s0909049500013868] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/20/2000] [Accepted: 10/04/2000] [Indexed: 05/23/2023]
Abstract
The results of high-heat-load tests of indirectly cryogenically cooled silicon monochromators are presented. The measurements show that, provided that the total power absorbed by the crystal is less than approximately 150 W, indirect cryogenically cooled silicon monochromators will perform well, with thermal-induced slope errors of less than 2 arcsec. At the Advanced Photon Source, this corresponds to the undulator closed-gap (11 mm) condition at 100 mA with white-beam slit sizes slightly larger than the full width at half-maximum of the radiation central cones. The dependence of the slope errors on the thermomechanical properties of silicon are discussed and clearly demonstrated.
Collapse
|
90
|
Abstract
This article examines the changing patterns of poverty in Singapore. As Singapore's population ages, the poor increasingly includes the elderly. It appears that ascribed factors, such as gender and race, have significant influence on financial security at old age. As the population ages, the adequacy of existing anti-poverty policy is challenged.
Collapse
|
91
|
Song J, Park YB, Lee WK, Lee KH, Lee SK. Clinical associations of anti-endothelial cell antibodies in patients with systemic lupus erythematosus. Rheumatol Int 2000; 20:1-7. [PMID: 11149654 DOI: 10.1007/s002960000060] [Citation(s) in RCA: 45] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
The aim of this study was to define the clinical associations of anti-endothelial cell antibody (AECA) in systemic lupus erythematosus (SLE) patients by measuring serum AECA titers to correlate with the disease activity and clinical manifestations. Forty-one SLE patients and 27 controls were studied. Serum samples were collected at the time of patient presentation with disease exacerbation and 4 weeks after the start of treatment. The disease activity was evaluated by the SLE Disease Activity Index (SLEDAI). AECA was detected by enzyme-linked immunosorbent assay (ELISA) methods with the surface antigen of the immortalized human microvascular endothelial cell line (HMEC-1). The mean immunoglobulin (Ig)G-AECA and IgM-AECA optical densities (ODs) were significantly higher in patients with SLE compared with controls [mean +/- standard deviation (SD), 0.32 +/- 0.15 vs 0.18 +/- 0.16 and 0.29 +/- 0.14 vs 0.21 +/- 0.09, respectively]. There was a positive correlation between IgG-AECA and the SLEDAI scores. The positivity rate of AECA in the groups with digital vasculitis, neuropsychiatric lupus, and anti-cardiolipin antibody was significant. In conclusion, AECA may be involved in the pathogenesis of SLE and was correlated with the disease activity. It was also associated with clinical manifestations such as digital vasculitis, neuropsychiatric lupus, and anti-cardiolipin antibody positivity.
Collapse
|
92
|
Lee WK, Kim HK. Feeder vessel laser photocoagulation of subfoveal choroidal neovascularization. KOREAN JOURNAL OF OPHTHALMOLOGY 2000; 14:60-8. [PMID: 11213736 DOI: 10.3341/kjo.2000.14.2.60] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
We performed laser photocoagulation for extrafoveal feeder vessels in a series of 10 eyes with subfoveal choroidal neovascular membranes (CNVMs) in which feeder vessels could be detected by means of indocyanine green angiography using scanning laser ophthalmoscope. On the follow up indocyanine green angiograms performed within one week after treatment, successful occlusion of the feeder vessels with nonperfusion of the corresponding CNVMs was observed in 8 eyes (80%). Four eyes showed improved visual acuities with resolution of the exudative manifestation. But within 3 months, recanalization of the feeder vessels or further proliferation of the CNVMs developed in 7 eyes. We confirmed the possibility of infarction and regression of the CNVM by feeder vessel photocoagulation, which could improve the visual acuity. But it was rarely possible to maintain them.
Collapse
|
93
|
Lee WK, Park KD, Han DK, Suh H, Park JC, Kim YH. Heparinized bovine pericardium as a novel cardiovascular bioprosthesis. Biomaterials 2000; 21:2323-30. [PMID: 11026639 DOI: 10.1016/s0142-9612(00)00159-9] [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: 11/27/2022]
Abstract
A novel chemical modification of biological tissues was developed by the direct coupling heparin to bovine pericardium (BP). The heparinization involves pretreatment of BP using GA and followed by grafting heparin to BP by the reaction of residual aldehyde and amine group of heparin. BP was modified by direct coupling of heparin and the effect of heparin coupling on calcification was evaluated in vitro and in vivo. Heparinized BP was characterized by measuring shrinkage temperature, mechanical properties, digestion resistance to collagenase enzyme, in vitro cytotoxicity, and in vivo calcification. Thermal and mechanical properties showed that the durability of heparin-treated tissue increased as compared with fresh tissue and GA-treated tissue. Resistance to collagenase digestion revealed that heparin-treated tissue has greater resistance to enzyme digestion than did fresh tissue and GA-treated tissue. Heparinized tissue had shown to be non-cytotoxic, however, relatively high cytotoxicity was observed in the GA-treated tissues due to the release of GA. In vivo calcification study demonstrated much less calcium deposition on heparin-treated BP than GA-treated one. Obtained results attest to the usefulness of heparinized BP for cardiovascular bioprostheses.
Collapse
|
94
|
Kim JS, Lee WK, Rim JA, Jensen WP, Lee JH, Kim MJ, Kim JG, Suh IH. 25,27-(6-Tosyl-3,9-dioxa-6-azaundecane-1,11-diyldioxy)-26,28-(3,6, 9-trioxaundecane-1,11-diyldioxy)calix[4]arene. Acta Crystallogr C 2000; 56 Pt 11:1369-71. [PMID: 11077302 DOI: 10.1107/s0108270100010921] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2000] [Accepted: 08/07/2000] [Indexed: 11/10/2022] Open
Abstract
A new calix[4]-crowned azacrown ether, C(51)H(59)NO(11)S, consisting of four phenyl rings in a 1,3-alternate conformation was synthesized from the reaction of 25, 27-bis(5-chloro-3-oxapentyloxy)calix[4]crown-5 and p-toluenesulfonamide in the presence of Cs(2)CO(3). A crown-5 loop was attached on the two facing lower rims of the calix[4]arene and the N-tosyl azacrown group was attached on the other set of lower rims of the calix[4]arene backbone. This molecule seems to offer an inside cavity for the formation of a host-guest complex.
Collapse
|
95
|
Pu XY, Chan CW, Lee WK. Measurement of the internal lasing intensity distribution of a dye-doped pendant drop. OPTICS LETTERS 2000; 25:1514-1516. [PMID: 18066263 DOI: 10.1364/ol.25.001514] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
The lasing intensity distribution made inside a circular resonator formed by a dye-doped pendant drop was measured by addition of polymer particles to the dye solution to enhance the elastic-scattered light of the lasing inside the pendant drop. A theory that connects wave and ray pictures in dealing with the cavity resonance is used to calculate the internal intensity distribution. The experimental and theoretical results are in good agreement for sufficiently large densities of scattering particles, such that the cavity mode efficiency phi is approximately 1 for all resonant modes.
Collapse
|
96
|
Lee WK, Padmanabhan S, Dominiczak AF. Genetics of hypertension: from experimental models to clinical applications. J Hum Hypertens 2000; 14:631-47. [PMID: 11095156 DOI: 10.1038/sj.jhh.1001043] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Human essential hypertension is a complex, multifactorial, quantitative trait under a polygenic control. Over the last decade several strategies have been used to dissect the genetic determinants of hypertension. Of these strategies, the study of rare monogenic forms of hypertension has been the most successful. Attempts to identify the multiple genes involved in the more common polygenic form of hypertension has been more difficult. Many laboratories use rat models of genetic hypertension where some of the complexity of studying human hypertension can be removed. Numerous crosses between hypertensive and normotensive strains have produced several quantitative trait loci (QTL) for blood pressure and other related phenotypes such as left ventricular hypertrophy, stroke, insulin resistance and kidney failure. In this review we describe established and novel strategies to dissect the susceptibility and severity loci for human essential hypertension. We also illustrate a few successful examples of a direct translation of genetic discoveries from the experimental setting to human investigation. The use of new molecular tools such as gene 'chips' or microarrays for either gene expression profiling or single nucleotide polymorphisms (SNPs)-based total genome scanning strategies will ultimately result in new diagnostics and therapeutics for human essential hypertension.
Collapse
|
97
|
Chung WG, Park CS, Roh HK, Lee WK, Cha YN. Oxidation of ranitidine by isozymes of flavin-containing monooxygenase and cytochrome P450. JAPANESE JOURNAL OF PHARMACOLOGY 2000; 84:213-20. [PMID: 11128045 DOI: 10.1254/jjp.84.213] [Citation(s) in RCA: 63] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Rat and human liver microsomes oxidized ranitidine to its N-oxide (66-76%) and S-oxide (13-18%) and desmethylranitidine (12-16%). N- and S-oxidations of ranitidine were inhibited by metimazole [flavin-containing monooxygenase (FMO) inhibitor] to 96-97% and 71-85%, respectively, and desmethylation of ranitidine was inhibited by SKF525A [cytochrome P450 (CYP) inhibitor] by 71-95%. Recombinant FMO isozymes like FMO1, FMO2, FMO3 and FMO5 produced 39, 79, 2180 and 4 ranitinine N-oxide and 45, 0, 580 and 280 ranitinine S-oxide pmol x min(-1) x nmol(-1) FMO, respectively. Desmethyranitinine was not produced by recombinant FMOs. Production of desmethylranitidine by rat and human liver microsomes was inhibited by tranylcypromine, a-naphthoflavon and quinidine, which are known to inhibit CYP2C19, 1A2 and 2D6, repectively. FMO3, the major form in adult liver, produced both ranitidine N- and S-oxides at a 4 to 1 ratio. FMO1, expressed primarily in human kidney, was 55- and 13-fold less efficient than the hepatic FMO3 in producing ranitidine N- and S-oxides, respectively. FMO2 and FMO5, although expressed slightly in human liver, kidney and lung, were not efficient producers of ranitidine N- and S-oxides. Thus, urinary contents of ranitidine N-oxide can be used as the in vivo probe to determine the hepatic FMO3 activity.
Collapse
|
98
|
Shin SJ, Lee WK, Lim HW, Park J. Characterization of the ATP transporter in the reconstituted rough endoplasmic reticulum proteoliposomes. BIOCHIMICA ET BIOPHYSICA ACTA 2000; 1468:55-62. [PMID: 11018651 DOI: 10.1016/s0005-2736(00)00241-8] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Adenosine triphosphate (ATP) transporter from rat liver rough endoplasmic reticulum (RER) was solubilized and reconstituted into phosphatidylcholine liposomes. The RER proteoliposomes, resulting from optimizing some reconstitution parameters, had an apparent K(m) value of 1.5 microM and a V(max) of 286 pmol min(-1) (mg protein)(-1) and showed higher affinity for ATP and a lower V(max) value than intact RER (K(m) of 6.5 microM and V(max) of 1 nmol). ATP transport was time- and temperature-dependent, inhibited by 4, 4'-diisothiocyanostilbene-2,2'-disulfonic acid, which is known as an inhibitor of anion transporters including ATP transporter, but was not affected by atractyloside, a specific inhibitor of mitochondrial ADP/ATP carrier. The internal and external effects of various nucleotides on the ATP transport were examined. ATP transport was cis-inhibited strongly by ADP and weakly by AMP. ADP-preloaded RER proteoliposomes showed a specific increase of ATP transport activity while AMP-preloaded RER proteoliposomes did not show the enhanced overshoot peak in the ATP uptake plot. These results demonstrate the ADP/ATP antiport mechanism of ATP transport in rat liver RER.
Collapse
|
99
|
She WL, Lee KK, Lee WK. All optical quasi-steady-state photorefractive spatial solitons. PHYSICAL REVIEW LETTERS 2000; 85:2498-2501. [PMID: 10978091 DOI: 10.1103/physrevlett.85.2498] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/06/2000] [Indexed: 05/23/2023]
Abstract
We have created a one- (rather than two-) dimensional quasi-steady-state photorefractive spatial soliton induced by a laser beam instead of an applied electric field. The formation of this type of spatial soliton depends on the intensity of the self-trapped beam, which is different from quasi-steady-state spatial solitons reported in the literature. The optically induced spatial soliton can be exploited in all optical switching applications.
Collapse
|
100
|
Kang WS, Lee WK, Seo MS, Kim JK, Han JW, Moon YW, Cho KK, Kim MJ, Lee KH, Kim YS, Jo YH, Choi CR. Cellular distribution of isozymes of protein kinase C in septal olfactory epithelium of mice. Neurosci Lett 2000; 288:143-6. [PMID: 10876081 DOI: 10.1016/s0304-3940(00)01230-1] [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: 11/22/2022]
Abstract
To determine the presence of protein kinase C (PKC) isozymes in the septal olfactory epithelium of mice (mSOE), western blotting and immunohistochemistry were performed using antibodies against PKC isozymes. With the exception of PKC-betaI, all of the PKC isozymes were detected in the whole lysate of septal tissue layer and apparent molecular weights for each isoform were found. PKC-alpha, PKC-gamma and PKC-epsilon were detected in the olfactory glandular cells of the lamina propria, and PKC-betaI and PKC-betaII were located in the microvillar cells. Neither novel PKC nor atypical PKC was detected in olfactory glandular cells or microvillar cells, except for PKC-epsilon. PKC-lambda was localized in the mucous layer of the mSOE. Meanwhile, PKC-delta and PKC-xi were distributed in the receptor cells in the mSOE. These data demonstrate the isoform-specific expression of PKC in mSOE and suggest a role for the novel and atypical types of PKC in olfactory transduction.
Collapse
|