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Meyer MD, Decker MW, Rueter LE, Anderson DJ, Dart MJ, Kim KH, Sullivan JP, Williams M. The identification of novel structural compound classes exhibiting high affinity for neuronal nicotinic acetylcholine receptors and analgesic efficacy in preclinical models of pain. Eur J Pharmacol 2000; 393:171-7. [PMID: 10771011 DOI: 10.1016/s0014-2999(00)00041-8] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/16/2022]
Abstract
Neuronal nicotinic acetylcholine receptors represent a new and potentially useful target for the development of novel non-opioid, non-NSAID (nonsteroidal antiinflammatory drug) analgesic agents. A variety of nicotinic acetylcholine receptor agonists such as nicotine, epibatidine and the azetidinyl ether, (R)-5-(2-azetidinylmethoxy-2-chloropyridine (ABT-594) possesses significant efficacy in preclinical models of pain. A preponderance of evidence suggests that nicotinic acetylcholine receptor agonists produce their analgesic effects predominantly via activation of descending inhibitory pain pathways originating in the key brainstem regions of the nucleus raphe magnus, dorsal raphe, and locus coeruleus, and that alpha4-containing nicotinic acetylcholine receptor subunits mediate these effects. Although these studies may provide a pharmacological target for the development of nicotinic acetylcholine receptor analgesics, the rational design of selective ligands based on the protein structure of the binding site is hampered by insufficient structural information. Using an approach based upon homology to known high-affinity ligands for the alpha4beta2 binding site, a four-point model is proposed which defines distance and directionality parameters common to this set of nicotinic acetylcholine receptor ligands.
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477
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Kim KH, Uehara M, Hess C, Sharma PA, Cheong SW. Thermal and electronic transport properties and two-phase mixtures in La(5/8-x)Pr(x)Ca(3/8)MnO3. PHYSICAL REVIEW LETTERS 2000; 84:2961-2964. [PMID: 11018986 DOI: 10.1103/physrevlett.84.2961] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/02/1999] [Indexed: 05/23/2023]
Abstract
We measured thermal conductivity kappa, thermoelectric power S, and electric conductivity sigma of La(5/8-x)Pr(x)Ca(3/8)MnO3, showing an intricate interplay between metallic ferromagnetism (FM) and charge ordering (CO) instability. The change of kappa, S, and sigma with temperature (T) and x agrees well with the effective medium theories for binary metal-insulator mixtures. This agreement clearly demonstrates that with the variation of T as well as x, the relative volumes of FM and CO phases drastically change and percolative metal-insulator transition occurs in the mixture of FM and CO domains.
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478
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Kim KH, Kim YB, Okuno O. Microfracture mechanisms of composite resins containing prepolymerized particle fillers. Dent Mater J 2000; 19:22-33. [PMID: 11219088 DOI: 10.4012/dmj.19.22] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
The effect of prepolymerized particle fillers on fracture toughness of four commercial composite resins was studied. The ground surface morphology was examined with a field emission scanning electron microscope. Fracture toughness was determined by using single edge notched specimens. Acoustic Emission (AE), which is the elastic wave due to the release of energy from the localized sources of material, was detected by sensors of a high-sensitivity and low-noise resonance type during the fracture toughness test. Acoustic Emission signals detected were analyzed for parameters such as amplitude and energy. Fracture surfaces were examined with a scanning electron microscope. The fracture toughness values, AE releasing patterns during fracture toughness test, and the fracture surface findings were analyzed to understand the fracture behavior of composite resins containing prepolymerized particle fillers. A microfracture model and fracture mechanisms to increase the fracture toughness of this type of composite resins are proposed.
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479
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Kim H, Seo JY, Kim KH. Inhibition of lipid peroxidation, NF-kappaB activation and IL-8 production by rebamipide in Helicobacter pylori-stimulated gastric epithelial cells. Dig Dis Sci 2000; 45:621-8. [PMID: 10749342 DOI: 10.1023/a:1005474013988] [Citation(s) in RCA: 56] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
The present study aimed to investigate whether rebamipide, a novel antiulcer agent that has an oxygen radical scavenging activity, would inhibit lipid peroxidation, NF-kappaB activation, and IL-8 production by H. pylori. Human gastric epithelial cells (AGS and KATO III), treated with rebamipide or not were incubated in the absence or the presence of H. pylori. As a result, H. pylori significantly stimulated IL-8 production, which was similar to time course stimulation of lipid peroxidation. Other cytokines (IL-1alpha, IL-1beta, IL-6, TNF-alpha) were not stimulated by H. pylori. Treatment with H. pylori resulted in the activation of two species of NF-kappaB dimers (a p50/p65 heterodimer and a p50 homodimer). Rebamipide significantly inhibited lipid peroxidation as an indicative of oxidative damage, NF-kappaB complex formation, and IL-8 production by H. pylori. In conclusion, rebamipide may attenuate H. pylori-induced gastric inflammation by inhibiting lipid peroxidation and oxidant-mediated activation of NF-kappaB and thereby decreasing IL-8 production.
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480
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Houghton J, Macera-Bloch LS, Harrison L, Kim KH, Korah RM. Tumor necrosis factor alpha and interleukin 1beta up-regulate gastric mucosal Fas antigen expression in Helicobacter pylori infection. Infect Immun 2000; 68:1189-95. [PMID: 10678925 PMCID: PMC97266 DOI: 10.1128/iai.68.3.1189-1195.2000] [Citation(s) in RCA: 63] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
Fas-mediated gastric mucosal apoptosis is gaining attention as a cause of tissue damage due to Helicobacter pylori infection. We explored the effects of H. pylori directly, and the effects of the inflammatory environment established subsequent to H. pylori infection, on Fas-mediated apoptosis in a nontransformed gastric mucosal cell line (RGM-1). Exposure to H. pylori-activated peripheral blood mononuclear cells (PBMCs), but not H. pylori itself, induced Fas antigen (Fas Ag) expression, indicating a Fas-regulatory role for inflammatory cytokines in this system. Of various inflammatory cytokines tested, only interleukin 1beta and tumor necrosis factor alpha induced Fas Ag expression, and removal of either of these from the conditioned medium abrogated the response. When exposed to Fas ligand, RGM-1 cells treated with PBMC-conditioned medium underwent massive and rapid cell death, interestingly, with a minimal effect on total cell numbers early on. Cell cycle analysis revealed a substantial increase in S phase cells among cells exposed to Fas ligand, suggesting an increase in their proliferative response. Taken together, these data indicate that the immune environment secondary to H. pylori infection plays a critical role in priming gastric mucosal cells to undergo apoptosis or to proliferate based upon their Fas Ag status.
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481
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Dart MJ, Wasicak JT, Ryther KB, Schrimpf MR, Kim KH, Anderson DJ, Sullivan JP, Meyer MD. Structural aspects of high affinity ligands for the alpha 4 beta 2 neuronal nicotinic receptor. PHARMACEUTICA ACTA HELVETIAE 2000; 74:115-23. [PMID: 10812947 DOI: 10.1016/s0031-6865(99)00023-0] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Neuronal nicotinic acetylcholine receptors (nAChRs) are a heterogeneous family of related ion channels that are widely distributed throughout the central and peripheral nervous systems. They all share a common architecture of five subunit proteins that combine at the cell surface to create a ligand-gated cation permeable pore. Significant effort is currently being expended by medicinal chemistry teams to synthesize ligands that exhibit selectivity for central over peripheral nAChR subtypes. Within the CNS, multiple nAChR subtypes are recognized, and the discovery of ligands exhibiting selectivity among these subtypes offers an opportunity for the development of novel therapeutic agents. The alpha 4 beta 2 subtype is one of the most abundant nAChR subtypes within the CNS, and has been the primary focus of high affinity ligand design. Nicotine (1), and more recently, epibatidine (2) have served as structural templates for the design of the majority of active compounds. Although the diversity of nAChR ligands is growing, the structural requirements necessary for high affinity binding with the alpha 4 beta 2 receptor remain poorly understood. The putative pharmacophoric elements common to all potent alpha 4 beta 2 ligands include (1) a basic or quaternized nitrogen atom, and (2) a less basic nitrogen or a carbonyl oxygen that presumably interact with electron rich and electron deficient sites on the receptor, respectively. The family of currently known high affinity analogs consists of a diverse array of azacycles containing a basic amine. Several additional basic amine fragments have been identified, including the pyrrolizidine nucleus (exemplified by 8) and the 2-azabicyclo[2.2.1]heptane skeleton (exemplified by 9). In addition, we have found that the furo[2,3-b]pyridine heterocycle (compound 10) serves as useful bioisosteric replacement for the pyridyl substituent of nicotine. A preliminary pharmacophore model is proposed in which a reasonable superposition of the putative pharmacophoric elements of the diverse array of high affinity ligands for the alpha 4 beta 2 nAChR reported herein may be accommodated.
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482
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Kim KH, Kim HJ, Kang JS, Mar W. Determination of metoprolol enantiomers in human urine by coupled achiral-chiral chromatography. J Pharm Biomed Anal 2000; 22:377-84. [PMID: 10719921 DOI: 10.1016/s0731-7085(99)00279-4] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
Achiral chiral column switching HPLC assay was developed to allow the separation and quantitation of the enantiomers of metoprolol in human urine by means of fluorescence detection. Urine samples were prepared by liquid liquid extraction, followed by HPLC. The racemic metoprolol and internal standard were separated from the interfering components in urine and quantified on the silica column, and the enantiomers were determined on a Chiralcel OD chiral stationary phase. The two columns were connected by a switching valve equipped with a silica trap column. Detection limit was 25 ng/ml for each enantiomer. The intra-day variation ranged between 0.38 and 4.94% in relation to the measured concentration and the inter-day variation was 0.15-3.13%. It has been applied to the determination of (R)-(+)-metoprolol and (S)-(-)-metoprolol in urine from healthy volunteers dosed with racemic metoprolol tartrate.
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483
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Kim KH, Strauss EG, Strauss JH. Adaptive mutations in Sindbis virus E2 and Ross River virus E1 that allow efficient budding of chimeric viruses. J Virol 2000; 74:2663-70. [PMID: 10684281 PMCID: PMC111755 DOI: 10.1128/jvi.74.6.2663-2670.2000] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Alphavirus glycoproteins E2 and E1 form a heterodimer that is required for virus assembly. We have studied adaptive mutations in E2 of Sindbis virus (SIN) and E1 of Ross River virus (RR) that allow these two glycoproteins to interact more efficiently in a chimeric virus that has SIN E2 but RR E1. These mutations include K129E, K131E, and V237F in SIN E2 and S310F and C433R in RR E1. Although RR E1 and SIN E2 will form a chimeric heterodimer, the chimeric virus is almost nonviable, producing about 10(-7) as much virus as SIN at 24 h and 10(-5) as much after 48 h. Chimeras containing one adaptive change produced 3 to 20 times more virus than did the parental chimera, whereas chimeras with two changes produced 10 to 100 times more virus and chimeras containing three mutations produced yields that were 180 to 250 times better. None of the mutations had significant effects upon the parental wild-type viruses, however. Passage of the triple variants eight or nine times resulted in variants that produced virus rapidly and were capable of producing >10(8) PFU/ml of culture fluid within 24 h. These further-adapted variants possessed one or two additional mutations, including E2-V116K, E2-S110N, or E1-T65S. The RR E1-C433R mutation was studied in more detail. This Cys is located in the putative transmembrane domain of E1 and was shown to be palmitoylated. Mutation to Arg-433 resulted in loss of palmitoylation of E1. The positively charged arginine residue within the putative transmembrane domain of E1 would be expected to alter the conformation of this domain. These results suggest that interactions within the transmembrane region are important for the assembly of the E1/E2 heterodimer, as are regions of the ectodomains possibly identified by the locations of adaptive mutations in these regions. Further, the finding that four or five changes in the chimera allow virus production that approaches the levels seen with the parental SIN and exceeds that of the parental RR illustrates that the structure and function of SIN and RR E1s have been conserved during the 50% divergence in sequence that has occurred.
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484
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Kim KH, Hwang YJ, Cho JB, Park SI. Immunization of cultured juvenile rockfish Sebastes schlegeli against Microcotyle sebastis (Monogenea). DISEASES OF AQUATIC ORGANISMS 2000; 40:29-32. [PMID: 10785860 DOI: 10.3354/dao040029] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
To determine whether immunization with Microcotyle sebastis antigen could induce protection against the parasite's establishment, naive juvenile rockfish were immunized by injection or immersion with whole worm antigen of M. sebastis. The infestation intensities of immunized groups following a challenge (2 wk after boosting) with 5000 M. sebastis eyed-eggs were significantly lower than those of control groups, when determined 7 wk postinfection. The fish in the groups boosted with M. sebastis antigen showed stronger protection than unboosted groups. The control group injected with FCA only showed a significantly smaller number of worms than the control group, which was immersed in PBS containing seawater. The results strongly suggest that both specific and nonspecific immune factors participate in the protection of rockfish against M. sebastis establishment.
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485
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Braun KW, Tribley WA, Griswold MD, Kim KH. Follicle-stimulating hormone inhibits all-trans-retinoic acid-induced retinoic acid receptor alpha nuclear localization and transcriptional activation in mouse Sertoli cell lines. J Biol Chem 2000; 275:4145-51. [PMID: 10660575 DOI: 10.1074/jbc.275.6.4145] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The regulation of retinoic acid receptor alpha (RARalpha) signal transduction has not been well characterized. In this study, we determined whether all-trans-retinoic acid (tRA) and follicle-stimulating hormone (FSH) modulate RARalpha receptor subcellular localization, leading to changes in its transcriptional activity and protein expression in mouse Sertoli cell lines. We found that tRA induced the nuclear localization of RARalpha within 30 min and that longer term exposure increased the receptor transcriptional activity and RARalpha protein expression. Conversely, FSH suppressed the tRA-induced nuclear localization, transcriptional transactivation, and protein expression of RARalpha. Treatment with two different protein kinase A-selective antagonists reversed the inhibitory actions of FSH on tRA-dependent RARalpha nuclear localization and transcriptional activity. These results are consistent with the involvement of protein kinase A in mediating the inhibitory effects of FSH. For the first time, we demonstrate a unique signaling convergence between the RARalpha and the FSH-mediated signaling pathways, which may have significant implications in the testis because both are critical regulators of testis physiology.
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486
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Singh BN, Kim KH. Floating drug delivery systems: an approach to oral controlled drug delivery via gastric retention. J Control Release 2000; 63:235-59. [PMID: 10601721 DOI: 10.1016/s0168-3659(99)00204-7] [Citation(s) in RCA: 356] [Impact Index Per Article: 14.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
In recent years scientific and technological advancements have been made in the research and development of rate-controlled oral drug delivery systems by overcoming physiological adversities, such as short gastric residence times (GRT) and unpredictable gastric emptying times (GET). Several approaches are currently utilized in the prolongation of the GRT, including floating drug delivery systems (FDDS), also known as hydrodynamically balanced systems (HBS), swelling and expanding systems, polymeric bioadhesive systems, modified-shape systems, high-density systems, and other delayed gastric emptying devices. In this review, the current technological developments of FDDS including patented delivery systems and marketed products, and their advantages and future potential for oral controlled drug delivery are discussed.
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487
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Kim KH, Sung CK, Park BK, Kim WK, Oh CW, Kim KS. Percutaneous gallbladder drainage for delayed laparoscopic cholecystectomy in patients with acute cholecystitis. Am J Surg 2000; 179:111-3. [PMID: 10773145 DOI: 10.1016/s0002-9610(00)00247-6] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
BACKGROUND Many studies have concluded that delayed or interval laparoscopic cholecystectomy (LC) in patients with acute cholecystitis (AC) demonstrated higher conversion rates and complication rates compared with early LC. However, if the acutely inflamed gallbladder is decompressed by emergent percutaneous gallbladder drainage (PGBD), it may decrease the technical difficulty of LC allowing successful delayed LC when the patient is in better condition. The purpose of this retrospective study was to assess the outcomes of delayed LC following PGBD in patients with AC. METHODS A total of 72 LC for AC were divided into PGBD (n = 27) and non-PGBD groups (n = 45). The PGBD group had delayed LC (after 72 hours of admission). Thirty-two non-PGBD patients had early LC (within 72 hours of admission) and 13 non-PGBD had delayed LC. Outcome of delayed LC for the PGBD group was assessed by LC time, conversion rate, morbidity rate, and hospital stay, and compared with that of the non-PGBD group. RESULTS Compared with early and delayed LC of the non-PGBD group, the PGBD group showed longer LC time (median 110 minutes versus 87.5 minutes versus 85 minutes, P <0. 05), a little lower conversion rate (15% versus 25% versus 23%), similar morbidity rate (15% versus 9% versus 15%), and prolonged hospital stay (13 days versus 7 days versus 10 days). CONCLUSIONS PGBD did not significantly improve the outcome of LC for AC as assessed by conversion and morbidity rate and hospital stay compared with no PGBD. Thus, we can conclude that although PGBD is a safe and effective emergency procedure for AC, it should be limited to higher risk groups such as elderly or critically ill patients and to acalculous cholecystitis.
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488
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Lee MW, Park MS, Jeong DW, Kim KH, Kim HH, Toh SH. Diarylheptanoids from the leaves of Alnus hirsuta Turcz. Arch Pharm Res 2000; 23:50-3. [PMID: 10728657 DOI: 10.1007/bf02976466] [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: 10/21/2022]
Abstract
Diarylheptanoids, (5S)-1,7-bis-(3,4-dihydroxyphenyl)-5-hydroxyheptane-3-one (1, hirsutanonol), (5S)-1,7-bis-(3,4-dihydroxyphenyl)-heptane-3-one-5-O-beta-D-xylopyranosi de (2, oregonin), (5R)-1,7-bis-(3,4-dihydroxyphenyl)-heptane-5-O-beta-D-xylopyranoside (3), and (5R)-1,7-bis-(3,4-dihydroxyphenyl)-heptane-5-O-beta-D-glucopyranoside (4) were isolated from the leaves of Alnus hirsuta Turcz. The structures of these compounds were identified based on the spectral and physicochemical data.
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489
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Abstract
Expression of critical enzymes in fatty acid and fat biosynthesis is tightly controlled by nutritional and hormonal stimuli. The expression of fatty acid synthase, which catalyzes all reactions for synthesis of palmitate from acetyl-CoA and malonyl-CoA, and of mitochondrial glycerol-3-phosphate acyltransferase, which catalyzes the first acylation step in glycerophospholipid synthesis, is decreased to an undetectable level during fasting. Food intake, especially a high carbohydrate, fat-free diet after fasting, causes a dramatic increase in the transcription of these genes. Insulin secretion is increased during feeding and has a positive effect on expression. By using adipocytes in culture and transgenic mice that express the reporter gene driven by the fatty acid synthase promoter, the cis-acting sequence that mediates insulin regulation of the fatty acid synthase promoter was defined. Upstream stimulatory factors (USF) that bind to the -65 E-box are required for insulin-mediated transcriptional activation of the fatty acid symthase gene. Sterol regulatory element binding protein (SREBP)-1 may be also involved in induction of these genes during feeding. Using specific inhibitors and expressing various signaling molecules, we found that insulin regulation of the fatty acid synthase promoter is mediated by the phosphatidylinositol (PI)3-kinase signaling pathway and that protein kinase B/akt is a downstream effector.
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490
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Jung SM, Lee BG, Joh GY, Cha JK, Chung WT, Kim KH. Primary Sjögren's syndrome manifested as multiple sclerosis and cutaneous erythematous lesions: a case report. J Korean Med Sci 2000; 15:115-8. [PMID: 10719822 PMCID: PMC3054592 DOI: 10.3346/jkms.2000.15.1.115] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/05/2022] Open
Abstract
Sjögren's syndrome is a chronic autoimmune disorder characterized by lymphocytic infiltration of the lacrimal and salivary glands, leading to dryness of eyes (kerato-conjunctivitis sicca) and mouth (xerostomia). The skin lesions in Sjögren's syndrome are usually manifested as xeroderma, but sometimes appear as annular erythema or vasculitis. Central nervous system symptoms may be presented as one of extraglandular manifestations, though rare in incidence, and need differential diagnosis from multiple sclerosis. We report a case of a 45-year-old woman diagnosed as multiple sclerosis at first but later as neurologic manifestation of primary Sjögren's syndrome, showing signs of multiple sclerosis and cutaneous erythematous lesions.
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491
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Kim KH, Kim DS, Hong SP, Keon OS. Reversed-phase high performance liquid chromatographic separation of the enantiomers of terbutaline by derivatization with 2,3,4,6-tetra-o-acetyl-beta-D-glucopyranosyl isothiocyanate. Arch Pharm Res 2000; 23:26-30. [PMID: 10728652 DOI: 10.1007/bf02976461] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
The enantiomers of the bronchodilator terbutaline were separated by reversed-phase high performance liquid chromatography after derivatization with 2,3,4,6-tetra-O-acetyl-beta-D-glucopyranosyl isothiocyanate(GITC) reagent. The derivatization proceeded quantitatively within 1 h at room temperature. The corresponding diastereomeric thiourea derivatives were well resolved on an ODS column with acetonitrile-acetate buffer as a mobile phase. Elution orders of the diastereomers were confirmed by derivatization of R-(-)-terbutaline and S-(+)-terbutaline which were collected by semi-preparative chiral HPLC using Sumichiral OA-4700 column. The native fluorescence of terbutaline was quenched by derivatization with GITC. The detection limit was 25 ng when monitored at UV 278 nm.
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492
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Cho KH, Ahn HT, Park KC, Chung JH, Kim SW, Sung MW, Kim KH, Chung PH, Eun HC, Youn JI. Reconstruction of human hard-palate mucosal epithelium on de-epidermized dermis. J Dermatol Sci 2000; 22:117-24. [PMID: 10674825 DOI: 10.1016/s0923-1811(99)00056-0] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Artificial hard-palate mucosa equivalents were reconstructed using keratinocytes derived from normal human hard-palate and de-epidermized dermis. Reconstructed hard-palate mucosal epithelium formed in three-dimensional culture was compared to native hard-palate mucosal epithelium and reconstructed oral buccal mucosal epithelium with regard to keratin expression. Artificial hard-palate mucosal epithelium reconstructed in medium with delipidized serum showed a differentiation pattern similar to that of hard-palate epithelium in vivo. The present study also confirmed that keratinocytes derived from hard-palate mucosa are intrinsically different from those of nonkeratinizing oral surfaces.
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493
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Moon SJ, Ahn W, Lee MG, Kim H, Lee SI, Seo JT, Case RM, Kim KH. A novel effect of rebamipide: generation of [Ca(2+)](i) oscillations through activation of CCK(1) receptors in rat pancreatic acinar cells. Eur J Pharmacol 2000; 388:17-20. [PMID: 10657542 DOI: 10.1016/s0014-2999(99)00849-3] [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
The protective effect of 2-(4-chlorobenzoylamino)-3-[2(1H)-quinolinon-4-yl]-propionic acid (rebamipide) on gastric mucosa is well established. Here we demonstrate that rebamipide acts on pancreatic acinar cells to generate oscillations of intracellular Ca(2+) concentration ([Ca(2+)](i)) through the activation of cholecystokinin subtype 1 (CCK(1)) receptors. At concentrations higher than 5 microM, rebamipide induced [Ca(2+)](i) oscillations in individual fura-2-loaded pancreatic acinar cells. The frequency of oscillations increased with increasing concentrations of rebamipide, while the latency between stimulation of cells and initiation of [Ca(2+)](i) oscillations decreased with increasing concentration. The [Ca(2+)](i) oscillations evoked by rebamipide were inhibited by the CCK(1) receptor antagonist L-364,718 but not by atropine or the CCK(2) receptor antagonist L-365,260 indicating that rebamipide is a nonpeptide CCK(1) receptor agonist.
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494
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Choy K, Pae EK, Park Y, Kim KH, Burstone CJ. Effect of root and bone morphology on the stress distribution in the periodontal ligament. Am J Orthod Dentofacial Orthop 2000; 117:98-105. [PMID: 10629526 DOI: 10.1016/s0889-5406(00)70254-x] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
To achieve predictable and physiologic orthodontic tooth movement, estimating the axis of rotation of a tooth and the level and location of maximum stress distributed in the periodontal ligament is essential. An extracted upper canine was scanned into a computer 2-dimensionally and divided into 80 nodes along the long axis of the tooth. A mathematical formula was derived, and stress was calculated on each node. The purpose of this study was to reveal the center of resistance, axis of rotation, and an ideal force magnitude associated with various periodontal conditions, such as potential root resorption, alveolar bone loss, and varying anatomic root shape by analyzing the stress distribution in the periodontal ligament. The study demonstrates that the location of center of resistance changes significantly with variation of shape and length of the root embedded in alveolar bone. In contrast, in response to alveolar bone loss, the relative location of the center of resistance to total root length remains constant. Analysis of the stress distribution pattern in our 2-dimensional model reveals that the relationship between location of force and axis of rotation is determined by s(2) (that is) a constant depends on shape and length of a root in alveolar bone. Tapered and short roots that result from alveolar bone loss or apical root resorption are prone to tipping. The optimal orthodontic force may vary depending on the maximum stress in the periodontal ligament.
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495
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Ro JY, Lee BC, Kim JY, Chung YJ, Chung MH, Lee SK, Jo TH, Kim KH, Park YI. Inhibitory mechanism of aloe single component (alprogen) on mediator release in guinea pig lung mast cells activated with specific antigen-antibody reactions. J Pharmacol Exp Ther 2000; 292:114-21. [PMID: 10604937] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/14/2023] Open
Abstract
We previously reported that the glycoprotein extracted from aloe strongly inhibited the mediator releases caused by the activation of guinea pig lung mast cells. Therefore, this study aimed to purify a single component that has an antiallergic effect from crude aloe extract and then to assess the effects of aloe single component (alprogen) on the mechanism of mediator releases caused by the mast cell activation. We purified aloe extracts by using various columns. We also purified mast cells from guinea pig lung tissues by using enzyme digestion, rough and discontinuous density Percoll gradient. Mast cells were sensitized with IgG(1) (anti-ovalbumin) and challenged with ovalbumin. Histamine was assayed by using a fluorometric analyzer and leukotrienes by radioimmunoassay. [Ca(2+)](i) level was analyzed by using a confocal laser scanning microscope. Protein kinase activity was determined by the protein phosphorylated with [gamma-(32)P]ATP. The phospholipase D activity was assessed by the labeled phosphatidylalcohol. The amount of mass 1,2-diacylglycerol (DAG) was measured by the [(3)H]DAG produced when prelabeled with [(3)H]myristic acid. Phospholipase A(2) activity was determined by measuring the lyso-phosphatidylcholine released from the labeled phospholipids. Alprogen significantly decreased histamine and leukotriene releases and blocked completely Ca(2+) influx during mast cell activation. The protein kinase C and phospholipase D activities were decreased by alprogen in dose-dependent manner. Alprogen inhibited mass DAG formation and the phospholipase A(2) activity during mast cell activation. The data suggest that alprogen purified from aloe inhibits multiple signals as well as blocking Ca(2+) influx caused by mast cells activated with specific antigen-antibody reactions and that then the inhibition of histamine and leukotriene release follows.
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496
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Park DH, Kim KH, Park SY, Lee BH, Choi CW, Chin SY. Diagnosis of recurrent uterine cervical cancer: computed tomography versus positron emission tomography. Korean J Radiol 2000; 1:51-5. [PMID: 11752929 PMCID: PMC2718139 DOI: 10.3348/kjr.2000.1.1.51] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
OBJECTIVE To determine the accuracy of CT and positron emission tomography (PET) in the diagnosis of recurrent uterine cervical cancer. MATERIALS AND METHODS Imaging findings of CT and PET in 36 patients (mean age, 53 years) in whom recurrent uterine cervical cancer was suspected were analyzed retrospectively. Between October 1997 and May 1998, they had undergone surgery and/or radiation therapy. Tumor recurrence was confirmed by pathologic examination or follow-up studies. RESULTS In detecting recurrent uterine cervical cancer, the sensitivity, specificity, and accuracy of CT were 77.8%, 83.3%, and 80.5%, respectively, while for PET, the corresponding figures were 100%, 94.4%, and 97.2%. The Chi-square test revealed no significant difference in specificity (p =.2888), but significant differences in sensitivity (p =.0339) and accuracy (p =.0244). CONCLUSION PET proved to be a reliable screening method for detecting recurrent uterine cervical cancer, but to determine the anatomical localization of recurrent tumors, and thus decide an adequate treatment plan, CT was eventually needed.
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497
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Lee DH, Yu JS, Hwang JC, Kim KH. Percutaneous placement of self-expandable metallic biliary stents in malignant extrahepatic strictures: indications of transpapillary and suprapapillary methods. Korean J Radiol 2000; 1:65-72. [PMID: 11752932 PMCID: PMC2718166 DOI: 10.3348/kjr.2000.1.2.65] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
OBJECTIVE To compare the efficacy of suprapapillary and transpapillary methods of transhepatic biliary metallic stent placement in malignant biliary strictures and to specify the indications of each method applied. MATERIALS AND METHODS Stents were placed in 59 patients. Strictures were categorized as type A (within 3 cm of the ampulla, n = 27), type B (over 3 cm from ampulla, n = 7), type C (within 3 cm of the bending portion, n = 9), or type D (over 3 cm above the bending portion, n = 16). The stenting method was suprapapillary in 34 cases and transpapillary in 25. The rates of initial and long-term patency and of early recurrence were compared. RESULTS Initial patency rates for the suprapapillary and transpapillary methods were 1/7 (14.3%) and 20/20 (100%) respectively for type A (p <0.0001), 4/5 (80.0%) and 2/2 for type B, 3/7 (42.9%) and 2/2 for type C, and 15/16 (93.8%) and 0/0 for type D. Early recurrence rates were 7/30 (23.3%) using the suprapapillary method and 4/29 (13.8%) using the transpapillary method (p = 0.51). The long-term patency rate did not differ significantly according to either type (p = 0.37) or method (p = 0.62). CONCLUSION For good initial patency, the transpapillary method is recommended for strictures of the distal extrahepatic duct near the ampulla and just above the bending portion. Long-term patency is not influenced by the stenting method employed.
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498
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Victor JD, Apkarian P, Hirsch J, Conte MM, Packard M, Relkin NR, Kim KH, Shapley RM. Visual function and brain organization in non-decussating retinal-fugal fibre syndrome. Cereb Cortex 2000; 10:2-22. [PMID: 10639391 DOI: 10.1093/cercor/10.1.2] [Citation(s) in RCA: 44] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Functional neuroimaging, psychophysical and electrophysiological investigations were performed in a patient with non-decussating retinal-fugal fibre syndrome, an inborn achiasmatic state in which the retinal projections of each eye map entirely to the ipsilateral primary visual cortex. Functional magnetic resonance imaging (fMRI) studies showed that for monocularly presented simple visual stimuli, only the ipsilateral striate cortex was activated. Within each hemisphere's striate cortex, the representation of the two hemifields overlapped extensively. Despite this gross miswiring, visual functions that require precise geometrical information (such as vernier acuity) were normal, and there was no evidence for the confounding of visual information between the overlapping ipsi-lateral and contralateral representations. Contrast sensitivity and velocity judgments were abnormal, but their dependence on the orientation and velocity of the targets suggests that this deficit was due to ocular instabilities, rather than the miswiring per se. There were no asymmetries in performance observed in visual search, visual naming or illusory contour perception. fMRI analysis of the latter two tasks under monocular viewing conditions indicated extensive bilateral activation of striate and prestriate areas. Thus, the remarkably normal visual behavior achieved by this patient is a result of both the plasticity of visual pathways, and efficient transfer of information between the hemispheres.
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499
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Abstract
OBJECTIVE Multilocular cystic renal cell carcinoma (MCRCC) is a recently described variety of renal cell carcinoma with characteristic pathologic and clinical features. The purpose of this study was to analyze the imaging findings of MCRCCs. MATERIALS AND METHODS Ten adult patients with pathologically proven unilateral MCRCC who underwent renal US and CT were included in this study. The radiologic findings were retrospectively evaluated for cystic content, wall, septum, nodularity, calcification and solid portion by three radiologists who established a consensus. Imaging and postnephrectomy pathologic findings were compared. RESULTS All patients were adults (six males and four females) and their ages ranged from 33 to 68 years (mean, 46). On US and CT images, all tumors appeared as well-defined multilocular cystic masses composed of serous or complicated fluid. In all patients, unenhanced CT scans revealed hypodense cystic portions, and in four tumors, due to the presence of hemorrhage or gelatinous fluid, some hyperdense areas were also noted. In no tumor was an expansile solid nodule seen in the thin septa, and in only one was there dystrophic calcification in a septum. Small areas of solid portion constituting less than 10% of the entire lesion were found in six of the ten tumors, and these areas were slightly enhanced on enhanced CT scans. In all patients, imaging and pathologic findings correlated closely. CONCLUSION On US and CT images, MCRCC appeared as a well-defined multilocular cystic mass with serous, proteinaceous or hemorrhagic fluid, with no expansile solid nodules in the thin septa, and sometimes with small slightly enhanced solid areas. Where radiologic examinations demonstrate a cystic renal mass of this kind in adult males, MCRCC should be included in the differential diagnosis.
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500
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Han JY, Kim KH, Lee HD, Moon SY, Shaffer LG. De novo direct duplication of 15q15-->q24 in a newborn boy with mild manifestations. AMERICAN JOURNAL OF MEDICAL GENETICS 1999; 87:395-8. [PMID: 10594877 DOI: 10.1002/(sici)1096-8628(19991222)87:5<395::aid-ajmg5>3.0.co;2-h] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Duplication of distal 15q results in a recognizable clinical phenotype. We report here on a 25-day-old boy with a de novo interstitial duplication of chromosome region 15q15-q24. The manifestations in this patient are milder than those of previously described patients and include minor facial anomalies, velopharyngeal insufficiency, branchial cleft cyst, and hydronephrosis. Fluorescence in situ hybridization (FISH) using a chromosome 15 painting probe confirmed that the extra material is of chromosome 15 origin. Further analysis with the SNRPN probe demonstrated that the duplication is telomeric to the Prader-Willi/Angelman syndrome critical region. This case delineates a broader spectrum for patients with duplication 15q syndrome.
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