2301
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Abstract
In the past 8 yrs, 14 children were treated with obstructing lesions of the larynx, some of then acquired from prolonged intubation. Endoscopic resection of the obstructions proved feasible in selected cases. The use of a wire stylette of fine needle within a small ureteral catheter sheath provides a readily available and accurate means for dealing with some of these lesions.
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2302
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Kim SH, Kim JH, Hahn EW. The enhanced killing of irradiated HeLa cells in synchronous culture by hyperthermia. Radiat Res 1976; 66:337-45. [PMID: 1265224] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
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2303
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2304
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Abstract
From a historical curiosity at the turn of the century, today omphalocele and gastroschisis can be corrected with good results, thanks to innovative techniques and better understanding of the newborn. Associated anomalies consist mainly of malrotation, Meckel's diverticulum, intestinal atresia, congenital heart defects, and genitourinary abnormalities. Nonoperative management in certain centers has been sucessful for the very large omphaloceles with an intact sac; however, a secondary procedure is necessary. In the past 10 years, the use of Silastic sheeting and total parenteral nutrition has allowed early repair of even the most severe cases, with excellent end results and low mortality.
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2305
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Abstract
Plasma chromatography detects and identifies compounds in trace quantities at atmospheric pressure through characteristic positive and negative mobility spectra. To facilitate use of the technique to detect gas chromatographic effluents, a number of reference mobility spectra for different classes of compounds have been reported. Reference spectra for two more compounds, heroin and cocaine, are presented in this study. The primary ions found in these mobility spectra were determined to be M+, (M - H2)+, and (M - CH3CO2)+ for heroin and M+, (M - C6H5CO2)+ and (M - C6H5CO2 - CO2CH3)+ for cocaine using a directly interfaced plasma chromatograph-mass spectrometer. The identified ions agree closely with those predicted in the ion mobility spectra using mass-mobility correlation data coupled with chemical ionization mass spectrometry data. Also, an independent check demonstrating the reliability of reduced mobility values reported in earlier reference spectra was made.
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2306
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2307
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2308
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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] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
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2309
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2310
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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] [What about the content of this article? (0)] [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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2311
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2312
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Kim SH, Schmitz HH. Micro/macro cost-benefit analyses prove new data system's value to hospital, community. Hosp Financ Manage 1975; 29:48-53. [PMID: 10308686] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/12/2023]
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2313
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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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2314
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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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2315
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2316
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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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2317
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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] [What about the content of this article? (0)] [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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2318
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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] [What about the content of this article? (0)] [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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2319
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2320
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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] [What about the content of this article? (0)] [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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2321
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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] [What about the content of this article? (0)] [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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2322
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Kim JH, Kim SH, Hahn E. Thermal enhancement of the radiosensitivity using cultured normal and neoplastic cells. Am J Roentgenol Radium Ther Nucl Med 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] [What about the content of this article? (0)] [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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2323
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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] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
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2324
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2325
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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] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
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2326
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2327
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2328
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2329
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2330
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2331
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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] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
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2332
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Kim SH, Quigley G, Suddath FL, McPherson A, Sneden D, Kim JJ, Weinzierl J, Rich A. X-ray crystallographic studies of polymorphic forms of yeast phenylalanine transfer RNA. J Mol Biol 1973; 75:421-8. [PMID: 4580683 DOI: 10.1016/0022-2836(73)90031-4] [Citation(s) in RCA: 29] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
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2333
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Sneden D, Miller DL, Kim SH, Rich A. Preliminary x-ray analysis of the crystalline complex between poypeptide chain elongation factor, Tu, and GDP. Nature 1973; 241:530-1. [PMID: 4571529 DOI: 10.1038/241530a0] [Citation(s) in RCA: 25] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
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2334
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2335
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Kim SH, Quigley GJ, Suddath FL, McPherson A, Sneden D, Kim JJ, Weinzierl J, Rich A. Three-dimensional structure of yeast phenylalanine transfer RNA: folding of the polynucleotide chain. Science 1973; 179:285-8. [PMID: 4566654 DOI: 10.1126/science.179.4070.285] [Citation(s) in RCA: 332] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
At 4 A resolution the polynucleotides in yeast phenylalanine transfer RNA are seen in a series of electron dense masses about 5.8 A apart. These peaks are probably associated with the phosphate groups, while lower levels of electron density between segments of adjacent polynucleotide chains are interpreted as arising from hydrogen-bonded purine-pyrimidine base pairs. It is possible to trace the entire polynucleotide chain with only two minor regions of ambiguity. The polynucleotide chain has a secondary structure consistent with the cloverleaf conformation; however, its folding is different from that proposed in any model. The molecule is made of two double-stranded helical regions oriented at right angles to each other in the shape of an L. One end of the L has the CCA acceptor; the anticodon loop is at the other end, and the dihydrouridine and TpsiC loops form the corner.
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2336
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Kim SH, Quigley G, Suddath FL, McPherson A, Sneden D, Kim JJ, Weinzierl J, Blattmann P, Rich A. The three-dimensional structure of yeast phenylalanine transfer RNA: shape of the molecule at 5.5-A resolution. Proc Natl Acad Sci U S A 1972; 69:3746-50. [PMID: 4566458 PMCID: PMC389863 DOI: 10.1073/pnas.69.12.3746] [Citation(s) in RCA: 24] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
Three isomorphous heavy-atom derivatives have been obtained of orthorhombic crystals of phenylalanine transfer RNA from yeast. These derivatives contain osmium, samarium, and platinum. The positions of the heavy atoms have been determined; these have been used to calculate a three-dimensional electron-density map of transfer RNA at a resolution of 5.5 A. The map shows a high contrast between the molecular boundaries and the solvent areas, so that most of the external shape of the molecule can be determined. The molecule appears to be 92 A long and to have a width varying from 16 A to 34 A. There are some narrow regions in the molecule that connect more globular regions. The electron density map shows chains of dense objects approximately 6 A apart that are probably due to adjacent phosphate groups on the polynucleotide chain. At the present stage of the analysis it is not possible to trace the entire backbone unambiguously; however, the data at this resolution suggest no apparent similarity between the folding of the molecule and any of the tertiary structure models proposed for transfer RNA.
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2337
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Sussman JL, Seeman NC, Kim SH, Berman HM. Crystal structure of a naturally occurring dinucleoside phoaphate: uridylyl 3',5'-adenosine phosphate model for RNA chain folding. J Mol Biol 1972; 66:403-21. [PMID: 5037021 DOI: 10.1016/0022-2836(72)90423-8] [Citation(s) in RCA: 154] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
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2338
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Kim SH, Kim JH. Lethal effect of adriamycin on the division cycle of HeLa cells. Cancer Res 1972; 32:323-5. [PMID: 5058189] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
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2339
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Seeman NC, Sussman JL, Berman HN, Kim SH. Nucleic acid conformation: crystal structure of a naturally occurring dinucleoside phosphate (UpA). Nat New Biol 1971; 233:90-2. [PMID: 5287004 DOI: 10.1038/newbio233090a0] [Citation(s) in RCA: 54] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
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2340
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Kim SH, Quigley G, Suddath FL, Rich A. High-resolution x-ray diffraction patterns of crystalline transfer RNA that show helical regions. Proc Natl Acad Sci U S A 1971; 68:841-5. [PMID: 5279525 PMCID: PMC389056 DOI: 10.1073/pnas.68.4.841] [Citation(s) in RCA: 61] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
Abstract
Yeast phenylalanyl transfer RNA crystallizes in a simple orthorhombic unit cell (a = 33.2, b = 56.1, c = 161 A), and the crystal yields an x-ray diffraction pattern with a resolution of 2.3 A. From an analysis of the packing in the unit cell it is concluded that the molecular dimensions are approximately 80 by 33 by 28 A. The diffraction pattern viewed along the a-axis has a distribution characteristic of double-helical nucleic acids. However, this distribution is not found when the pattern is viewed along the b-axis. This has been interpreted as indicating that the double-helical portions of the transfer RNA molecule are approximately half a helical turn in length, and therefore can contain 4-7 base pairs. These results are consistent with the cloverleaf formulation of transfer RNA secondary structure.
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2341
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Kim SH, Kim JH, Djordjevic B. Effects of x-irradiation on RNA and protein synthesis in HeLa cells. Radiat Res 1970; 42:577-89. [PMID: 5421861] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
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2342
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Abstract
An orthorhombic form of crystalline formylmethionine transter RNA has been obtained which contains one molecule as the asymmetric unit of the unit cell. Three-dimensional x-ray diffraction data have been collected up to a resolution of 12 angstroms, and from this a Patterson function has been calculated. The function contains an elongated ridge of interatomic vectors parallel to the c-axis of the crystal. Analysis of the function suggests that the molecules are elogated and dimerized in an overlapping antiparrael fashion along the c-axis. The dimer has a length near 109 angstroms and a width of 35 angstroms in one direction. The individual molecular length is approximately 80 angstroms with an irregular cross section measuring 25 by 35 angstrms.
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2343
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2344
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2345
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Abstract
Large single crystals of formylmethionyl transfer RNA have been prepared. An x-ray diffraction study shows that the material crystallizes in a hexagonal lattice with a equal to 170 angstroms, c equal to 234 angstroms. The diffraction pattern extends to spacings just under 20 angstroms at present. The crystals are heavily hydrated, containing 88 percent water.
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2346
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Kim JH, Gelbard AS, Djordjevic B, Kim SH, Perez AG. Action of daunomycin on the nucleic acid metabolism and viability of HeLa cells. Cancer Res 1968; 28:2437-42. [PMID: 5728152] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
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2347
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Djordjevic B, Kim JH, Kim SH. Modification of radiation response in synchronized HeLa cells by metabolic inhibitors. I. Effect of an inhibitor of RNA-synthesis, puromycin aminonucleoside. Int J Radiat Biol Relat Stud Phys Chem Med 1968; 14:1-7. [PMID: 5302636 DOI: 10.1080/09553006814550721] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
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2348
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Abstract
9-Ethylhypoxanthine and 5-fluorouracil form a 1 : 1 crystalline complex. The structure of this complex has been solved by x-ray diffraction analysis. The molecules crystallize in a monoclinic lattice and form a sheet structure in which pairs of fluorouracil molecules are held together by two hydrogen bonds. The 9-ethylhypoxanthine residues fill up the rest of the molecular sheet by forming single hydrogen bonds with each uracil pair.
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2349
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2350
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