2376
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2377
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Kim SH, Yun DJ, Kim TS. A case of cryptococcosis treated with 5-fluorocytosine. Yonsei Med J 1976; 17:52-8. [PMID: 1031502 DOI: 10.3349/ymj.1976.17.1.52] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
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2378
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Kim SH. Three-dimensional structure of transfer RNA. PROGRESS IN NUCLEIC ACID RESEARCH AND MOLECULAR BIOLOGY 1976; 17:181-216. [PMID: 778921 DOI: 10.1016/s0079-6603(08)60070-7] [Citation(s) in RCA: 68] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
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2379
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Quigley GJ, Wang AH, Seeman NC, Suddath FL, Rich A, Sussman JL, Kim SH. Hydrogen bonding in yeast phenylalanine transfer RNA. Proc Natl Acad Sci U S A 1975; 72:4866-70. [PMID: 1108007 PMCID: PMC388833 DOI: 10.1073/pnas.72.12.4866] [Citation(s) in RCA: 79] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Further analysis of the three-dimensional electron density map of yeast phenylalanine tRNA is presented. Attention is focused on the several types of unique hydrogen bonding that are found in the molecule and a number of sections of the electron density map are presented. These sections are compared with an electron density map of a dinucleoside phosphate. The bases in the helical stem regions are all involved in Watson-Crick hydrogen bonding interactions with the exception of the guanine-uracil base pair. Several additional tertiary hydrogen bonding interactions are described.
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2380
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2381
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Kim SH, Schmitz HH. Micro/macro cost-benefit analyses prove new data system's value to hospital, community. HOSPITAL FINANCIAL MANAGEMENT 1975; 29:48-53. [PMID: 10308686] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/12/2023]
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2382
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Lee KH, Ibuka T, Kim SH, Vestal BR, Hall IH, Huang ES. Antitumor agents. 16. Steroidal alpha-methylene-gamma-lactones. J Med Chem 1975; 18:812-7. [PMID: 1159698 DOI: 10.1021/jm00242a010] [Citation(s) in RCA: 39] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Several novel steroidal alpha-methylene-gamma-lactones and related derivatives have been synthesized as potential steroid alkylating antitumor agents. The synthesis of these compounds involved the convenient Reformatsky-type reaction between ethyl-alpha-(bromomethyl)acrylate and the proper steroidal ketones. In vitro assay for the cytotoxicity of these compounds against the growth of tissue culture cells originating from human epidermoid carcinoma of the larynx (H.Ep.-2) has shown significant activity. Cytotoxicity was improved at least sixfold with the introduction of lipophilic steroidal character. Preliminary in vivo tumor assay also indicated that these compounds were active against Walker 256 carcinosarcoma in rats and were inactive against both L1210 lymphoid leukemia and Ehrlich ascites carcinoma in mice. However, the simple alpha-methylene-beta,beta-dicarbethoxy-gamma-butyrolactone significantly inhibited Ehrlich ascites tumor growth.
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2383
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Langlois R, Kim SH, Cantor CR. A comparison of the fluorescence of the Y base of yeast tRNA-Phe in solution and in crystals. Biochemistry 1975; 14:2554-8. [PMID: 1095057 DOI: 10.1021/bi00682a040] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
The fluorescence properties of the Y base of yeast tRNA-Phe are known to be quite sensitive to the environment. The fluorescence lifetime of the Y base in yeast tRNA-Phe is identical in orthorhombic crystals and in the mother liquor from which these crystals are grown. It is 10% higher than the lifetime observed in dilute solutions of tRNA. This small change is a solvent effect due to isopropyl alcohol in the crystallization medium. Isopropyl alcohol does not change the accessibility of the chromophore of the Y base as measured by iodide quenching rates in solution. The accessibility in intact tRNA-Phe is much less than in a ribonuclease digest. Thus, within the limits of the sensitivity of the method, the Y chromophore occupies the same environment in solution and in the crystal and it must be at least partially buried.
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2384
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2385
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Abstract
The influence of hyperthermia on the survival of irradiated oxic and hypoxic HeLa cells was determined. A significant reduction in OER was obtained for irradiated cells subsequently cultivated at 42-degrees C for two hours compared to irradiated cells cultivated at 37-degrees C. These results suggest that heating irradiated hypoxic cells is an effective means of reducing the oxygen dependence factor in radiation effects.
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2386
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Karasek FW, Karasek DE, Kim SH. Detection of lysergic acid diethylamide, delta-9-tetrahydrocannabinol and related compounds by plasma chromatography. J Chromatogr A 1975; 105:345-52. [PMID: 1158994 DOI: 10.1016/s0021-9673(01)82264-0] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Plasma chromatography as a method for ultratrace qualitative and quantitative detection of organic compounds is especially well suited for detection of gas chromatographic effluents. The optimum range of sample quantity is 10-6 to 10-12 g for detection and identification of a compound by use of its characteristic positive and negative mobility spectra. The type of reference mobility spectra produced by alkanes, aromatics, esters, halogenated compounds, nitrogenated compounds and organic acids have been previously reported. This study presents the reference mobility spectra produced for lysergic acid diethylamide (LSD), delta-9-tetrahydrocannabinol (delta-9-THC), digitoxigenin and several biochemical compounds of research significance. LSD and delat-9-THC in a mixture can be detected and identified by plasma chromatography positive mobility spectra in quantities of 10-7 g or less. All the compounds investigated in this study display strong MH-+ ions along with other ions primarily of the type (M)NO-+, (M)2H-+. None of these compounds exhibits negative mobility spectra.
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2387
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Lee KH, Kim SH, Furukawa H, Piantadosi C. Antitumor agents. 11. Synthesis and cytotoxic activity of epoxides of helenalin related derivatives. J Med Chem 1975; 18:59-63. [PMID: 1109577 DOI: 10.1021/jm00235a013] [Citation(s) in RCA: 25] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Several epoxides of helenalin related derivatives have been synthesized in an effort to evaluate the potential significance of the epoxycyclopentanone moiety for cytotoxic activity against the growth of tissue culture cells originating from human epidermoid carcinoma of larynx (H.Ep-2). Helenalin (1) was converted to the monoepoxy derivative 2 and the diepoxy derivative 3 by alkaline hydrogen peroxide at different temperatures. Alternative synthesis of 2 was achieved by a convenient method of protecting the alpha-methylene grouping of the gamma-lactone, i.e., epoxidation of helenalin dimethylamine adduct 4, followed by treatment of the reaction product 5 with m-chloroperbenzoic acid. 2,3-Epoxy-11,13-dihydrohelenalin (8) was prepared by direct epoxidation of 11,13-dihydrohelenalin (7). Treatment of mexicanin A (9) with m-chloroperbenzoic acid gave, in addition to the 1,2-epoxy derivative 10, 1-alpha-hydroxyhelenalin (11) which furnished an acetate (12) upon acetylation. Catalytic hydrogenation of 10 yielded the dihydroepoxide 13. Treatment of 1 or acetylhelenalin (15) with Ac2O-p-TsOH gave the same acetyl dienol acetate (14). Epoxidation of 14 with m-chloroperbenzoic acid gave 1,beta hydroxyhelenalin (19) and a mixture of monoepoxides (17 and 18) which yielded 19 and 11 upon silica gel chromatography. The results of the cytotoxicity test of the compounds studied indicate that either an alpha- or a beta-epoxycyclopentanone moiety in helenalin related derivatives contributes significantly to the cytotoxicity. Furthermore, this cytotoxicity appears to be independent of the presence or absence of an alpha-epoxy-gamma-lactonic moiety.
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2388
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Kim SH, Lee KH, Kim SC, Chung SS, Lee KC, Lee HJ. Percutaneous cervical radiofrequency cordotomy for intractable pain. Yonsei Med J 1975; 16:72-82. [PMID: 1066872 DOI: 10.3349/ymj.1975.16.2.72] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
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2389
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Kim SH, Sussman JL, Suddath FL, Quigley GJ, McPherson A, Wang AH, Seeman NC, RICH A. The general structure of transfer RNA molecules. Proc Natl Acad Sci U S A 1974; 71:4970-4. [PMID: 4612535 PMCID: PMC434021 DOI: 10.1073/pnas.71.12.4970] [Citation(s) in RCA: 183] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
The three-dimensional structure of yeast phenylalanine tRNA serves as a useful basis for understanding the tertiary structure of all tRNAs. A large number of tRNA sequences have been surveyed and some general conclusions are drawn. There are only a few regions in the molecule in which there are differences in the number of nucleotides; and the structure of yeast phenylalanine tRNA can accommodate these differences by forming or enlarging protuberances on the surface of the basic framework molecule. The nature and distribution of the differences in number of nucleotides are surveyed and possible hydrogen bonding interactions are discussed for a number of tRNA classes. The two most significant features of the molecule are the large number of stacking interactions which are seen to include most of the nucleotides in the molecule and the system of specific hydrogen bonding interactions. It is likely that these stabilizing elements are preserved in all tRNA structures.
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2390
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Kim SH, Suddath FL, Quigley GJ, McPherson A, Sussman JL, Wang AH, Seeman NC, Rich A. Three-dimensional tertiary structure of yeast phenylalanine transfer RNA. Science 1974; 185:435-40. [PMID: 4601792 DOI: 10.1126/science.185.4149.435] [Citation(s) in RCA: 644] [Impact Index Per Article: 12.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
The 3-angstrom electron density map of crystalline yeast phenylalanine transfer RNA has provided us with a complete three-dimensional model which defines the positions of all of the nucleotide residues in the moleclule. The overall features of the molecule are virtually the same as those seen at a resolution of 4 angstroms except that many additional details of tertiary structure are now visualized. Ten types of hydrogen bonding are identified which define the specificity of tertiary interactions. The molecule is also stabilized by considerable stacking of the planar purines and pyrimidines. This tertiary structure explains, in a simple and direct fashion, chemical modification studies of transfer RNA. Since most of the tertiary interactions involve nucleotides which are common to all transfer RNA 's, it is likely that this three-dimensional structure provides a basic pattern of folding which may help to clarify the three-dimensional structure of all transfer RNA's.
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2391
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Kim JH, Kim SH, Hahn E. Thermal enhancement of the radiosensitivity using cultured normal and neoplastic cells. THE AMERICAN JOURNAL OF ROENTGENOLOGY, RADIUM THERAPY, AND NUCLEAR MEDICINE 1974; 121:860-4. [PMID: 4432967 DOI: 10.2214/ajr.121.4.860] [Citation(s) in RCA: 24] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
Cultures of normal tissue are relatively insensitive to heat, while malignant cells in culture are highly sensitive to thermal treatment. This differential thermal sensitivity is most pronounced when the cells of normal and neoplastic tissues are exposed to heat in their exponential growth phase. Dose survival curves of HeLa and 3T3 cells with and without postirradiation thermal treatment showed that the neoplastic HeLa line exhibited significant enhancement of radiosensitivity when the irradiated cells were exposed to elevated temperatures (42C. for 3 hours). Similar heat treatment of irradiated 3T3 fibroblasts did not appreciably enhance the radiation response. The potential significance of these findings for clinical radiotherapy is discussed.
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2392
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Lee KH, Kim SH, Piantadosi C, Huang ES, Geissman TA. Antitumor agents. 8. Synthesis and cytotoxic activity of O,O'-bis(acrylyl)-alpha,omega-alkanediols. J Pharm Sci 1974; 63:1162-3. [PMID: 4850611 DOI: 10.1002/jps.2600630734] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
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2393
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2394
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Suddath FL, Quigley GJ, McPherson A, Sneden D, Kim JJ, Kim SH, Rich A. Three-dimensional structure of yeast phenylalanine transfer RNA at 3.0angstroms resolution. Nature 1974; 248:20-4. [PMID: 4594440 DOI: 10.1038/248020a0] [Citation(s) in RCA: 122] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
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2395
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Hilbers CW, Shulman RG, Kim SH. High resolution NMR study of the melting of yeast tRNA Phe. Biochem Biophys Res Commun 1973; 55:953-60. [PMID: 4586623 DOI: 10.1016/0006-291x(73)91235-7] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
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2396
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2397
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2398
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Kim SH, Rubin BT. Theoretical free energy of activation for dehydration of hydrated ions in solution. THE JOURNAL OF PHYSICAL CHEMISTRY 1973; 77:1245-50. [PMID: 4709281 DOI: 10.1021/j100629a013] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
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2399
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Djordjevic B, Anderson LL, Kim SH. Oxygen enhancement ratios in Hela cells irradiated with californium and radium sources. Radiology 1973; 107:429-34. [PMID: 4695915 DOI: 10.1148/107.2.429] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
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2400
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Kim SH, Quigley G, Suddath FL, McPherson A, Sneden D, Kim JJ, Weinzierl J, Rich A. Unit cell transormations in yeast phenylalanine transfer RNA crystals. J Mol Biol 1973; 75:429-32. [PMID: 4580684 DOI: 10.1016/0022-2836(73)90032-6] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
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