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  • American Association for the Advancement of Science (AAAS)  (1.374)
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  • 1990-1994  (654)
  • 1980-1984  (744)
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  • American Association for the Advancement of Science (AAAS)  (1.374)
  • Wiley-Blackwell  (24)
  • Annual Reviews
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  • 1
    ISSN: 0009-2940
    Schlagwort(e): (Hydroxymethyl)diorganylsilanes, esters of ; Rearrangement, thermally induced ; Kinetics ; DSC ; Calculations, ab initio ; Chemistry ; Inorganic Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: Esters of (Hydroxymethyl)diorganylsilanes: Synthesis and Thermally Induced RearrangementTwenty silanes of the type R1R2Si(H)CH2OR3 (A) were synthesized [R1, R2 = Me, Ph, 1-naphthyl, PhCH2,Me3SiCH2; OR3 = OC(O)Me, OC(O)Ph, OC(O)CF3, OS(O)2CF3, OP(O)Ph2, OC(O)Cl] and studied for their thermal behaviour. The silanes A undergo a thermally induced rearrangement to give the corresponding silanes R1R2Si(OR3)Me (B). For compounds with OR3 = OC(O)Cl, an additional decarboxylation takes place to yield the chlorosilanes R1R2Si(Cl)Me. Except for the derivatives with OR3 = OC(O)Cl, the energetic (reaction enthalpy) and kinetic data (reaction order, frequency factor, enthalpy and entropy of activation) of these reactions were studied by means of differential scanning calorimetry (DSC). In addition, the kinetics of all reactions were investigated by 1H-NMR spectroscopy. The transition state of the rearrangement was investigated by an ab initio study based on the model compound H3SiCH2OC(O)H [→ MeH2SiOC(O)H]. The theoretical data and the experimentally obtained energetic and kinetic data are discussed in terms of mechanistic aspects of the rearrangement reaction A → B.
    Zusätzliches Material: 3 Tab.
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  • 2
    Digitale Medien
    Digitale Medien
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 125 (1992), S. 1647-1656 
    ISSN: 0009-2940
    Schlagwort(e): Cycloadditions ; Diels-Alder reactions ; Kinetics ; Zwitterionic intermediates ; Chemistry ; Inorganic Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: trans-1-(Dimethylamino)-1,3-butadiene is allowed to react with methyl acrylate, acrylonitrile, maleo- and fumaronitrile, dimethyl maleate and fumarate, as well as with dimethyl dicyanomaleate and dicyanofumarate. In all cases except the two last ones where only a single isomer is obtained mixtures (endo/exo) of cycloadducts are formed. Structures are determined by a combination of one- and two-dimensional NMR spectroscopy. The E/Z isomeric maleo- and fumaronitrile add stereospecifically to the diene. Cycloaddition of dimethyl maleate and fumarate leads to the same mixture of isomers in almost the same ratio. The reaction of dimethyl dicyanomaleate and dimethyl dicyanofumarate yields a cycloadduct which seems to be the thermodynamically most stable one. The results are interpreted in such a manner that a concerted cycloaddition takes place with maleo- and fumaronitrile, while stepwise reactions, presumably proceeding via zwitterions, are observed with dimethyl maleate, fumarate, the strongly electrophilic dimethyl dicyanomaleate and dicyanofumarate. With increasing capability of the dienophile to stabilize a negative charge the mechanism changes from a concerted to a stepwise reaction.
    Zusätzliches Material: 1 Ill.
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  • 3
    ISSN: 0009-2940
    Schlagwort(e): Radical stabilization, allylic ; Cope rearrangement ; C  -  C Bond cleavage ; Thermochemistry ; Kinetics ; Chemistry ; Inorganic Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: Thermolabile Hydrocarbons, 32.  -  Competing Cope-;Rearrangement and Homolytic Decomposition of meso- and DL-3,4-Di(1-cyclohexen-1-yl)-2,2,5,5-tetramethylhexanemeso- and DL-3,4-di(1-cyclohexen-1-yl)-2,2,5,5-tetramethylhexane (3a) were prepared by an improved reduction procedure (Li/C2H5NH2) from meso- and DL-2,2,5,5-tetramethyl-3,4-diphenylhexane. Products of two competing thermal transformations, C  -  C cleavage vs. Cope rearrangement, were isolated and identified. From a kinetic analysis of this system of reactions, characteristic activation enthalpies and entropies were obtained for the competing transformations. The standard heat of formation of meso-3a (ΔHf0(g) = -58.4 ± 1.2 kcal/mol) was determined by combustion calorimetry and by measurement of its heat of sublimation. A strain enthalpy Hs (meso- 3a) = 10.2 ± 1.2 kcal/mol was derived therefrom. Force-field calculations of the diastereomers of 3a and the Cope products 8a were performed by using MM2, MM2ERW, and MM3 in order to analyse the conformational situation. The calculated ΔHf0(g) values for meso-3a are higher than the experimental value by 4.4 (MM2), 5.2 (MM2ERW), and 14.5 (MM3) kcal/mol. Obviously, the three computational methods require reliable parameters for highly branched olefins like 3a and 5a. From the experimental heat of formation ΔHt0(g) and strain enthalpy Hs of meso-3a and its ΔH* of homolysis the stabilization energy of the allylic radical 4 was determined to be 12.6 ± 1.5 kcal/mol.
    Zusätzliches Material: 4 Ill.
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  • 4
    ISSN: 0009-2940
    Schlagwort(e): C-C Bond homolysis ; Thermolysis ; Kinetics ; Radical stabilisation ; Chemistry ; Inorganic Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: Substituent Effects on the C-C Bond Strength, 12[1].-Thermolysis of Aromatic Pinacol Dimethyl Ethers and Stabilisation Energies of α-Methoxybenzyl Radicals[2]The phenyl-substituted pinacol dimethyl ethers meso- and DL- 5a-d have been prepared by reductive dimerisation of the dimethyl acetals 7a-d of the ketones 8a-d. 1H-NMR spectra and GC-retention times are used to distinguish between the diastereomers, and an X-ray structure analysis of meso-5a confirms these distinctive criteria. The products and the kinetics of the thermolysis reaction of 5a-d have been studied. A linear correlation between ΔG+ (300°C) of thermolysis and strain enthalpies Hs of 5, or its release Ds during the dissoziation into radicals 6, is observed. These correlations do not differ from those of the thermolysis of tetraalkyl-diphenylethanes (1, R=alkyl, S=phenyl)[3,20a]. Hence, the methoxy group does not influence the homolysis reaction of the C-C bond in 5compared to an alkyl group. It is concluded that any stabilisation of the radicals 6 by the alkoxy group[1] is canceled by an extra stabilisation of 5 by the geminal phenyl/methoxy pairs.
    Zusätzliches Material: 2 Ill.
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  • 5
    Digitale Medien
    Digitale Medien
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 127 (1994), S. 525-531 
    ISSN: 0009-2940
    Schlagwort(e): Alkynes ; Alkenes ; Nucleophilicity ; Carbenium ions ; Vinyl cations ; Kinetics ; Chemistry ; Inorganic Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: Relative reactivities of alkenes and alkynes toward diarylmethyl cations have been determined by direct rate measurements and by competition experiments in dichloromethane. At -70°C alkynes are found to be one to two orders of magnitude less reactive than analogously substituted alkenes (e.g. phenylacetylene/styrene), but the reactivity difference reduces strongly as the temperature is raised. The stereochemistry of the vinyl chlorides produced by addition of benzhydryl chlorides to alkynes is characterized.
    Zusätzliches Material: 1 Ill.
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  • 6
    Digitale Medien
    Digitale Medien
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 127 (1994), S. 933-939 
    ISSN: 0009-2940
    Schlagwort(e): Ethylenediazonium salts, thermal stability of, thermal degradation of ; Ethenyl cations, generation of, rearrangement of, interception of ; Kinetics ; Chemistry ; Inorganic Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: Thermal decomposition of 2-substituted ethylenediazonium salts 1a-d produces the corresponding 1-ethenyl cations 2a-d as short-lived intermediates. The primary vinyl cation 2d or the rearranged and energetically favored analogues 3a-c of 2a-c are intercepted by chloride to give the decomposition products 4d and 5a-c, respectively. The generation of 4d and 5a-c as well as a kinetic study of the thermolysis reaction provide no indication that the elimination of nitrogen from 1a-d is occurring with the intermediate formation of cyclic cations 6 or 7.
    Zusätzliches Material: 1 Ill.
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  • 7
    Digitale Medien
    Digitale Medien
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 127 (1994), S. 673-675 
    ISSN: 0009-2940
    Schlagwort(e): Radicals ; Addition ; Alkynes ; Kinetics ; Supercritical fluid conditions ; Chemistry ; Inorganic Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: The kinetics of the addition of cyclohexane (2) to phenylethyne (1) proceeding via 2-cyclohexyl-1-phenylethenyl radical (3) to give 1-cyclohexyl-2-phenylethene (4) was investigated in the temperature range from 260 to 340°C. The radical chain is initiated by a bimolecular reaction of cyclohexane with phenylethyne to give a cyclohexyl radical and a 1-phenylethenyl radical. The physical state of the reaction mixture was varied from liquid to supercritical and to gasphase conditions. No effect on the reaction rate constant near the critical point was observed.
    Zusätzliches Material: 3 Ill.
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  • 8
    ISSN: 0009-2940
    Schlagwort(e): Cycloaddition ; Diels-Alder reaction ; Charge-transfer complex ; Kinetics ; Chemistry ; Inorganic Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: The Diels-Alder reaction of 1,2-dimethylenecyclopentane (1) and tetracyanoethylene (TCNE) is kinetically studied by conventional and stopped-flow UV/Vis absorption-spectroscopic techniques. A transient charge-transfer (CT) absorption band with λmmax=490 nm (half-life at 20°C ca. 3.4 × 10-2 s) is detected in dichloromethane solution. For the molar extinction coefficient a value of e490=310 M-1 cm-1 has been determined from measurements of the optical densitity at zero time as a function of excess diene concentration. With the aid of computer simulation the combined kinetic analysis of the disappearance of reactants and CT complex reveals that the data obtained from experiments at equimolar concentration and at a single temperature (20°C) can be interpreted equally well by both the model where the CT complex is an intermediate on the reaction path and where it is in a nonreactive side equilibrium with the reactants. Activation parameters have been determined for the disappearance of the starting compounds and of the CT complex. Contrary to what is expected for a CT complex being an intermediate in a concerted Diels-Alder reaction a more negative activation entropy for the decay of the CT complex than for the disappearance of the reactants is found. This suggests that the CT complex is unlikely to exhibit a transition-state-like structure as is required for a concerted cycloaddition. Experiments under pseudo-first-order conditions have led to an extension of the reaction scheme by a second-order reaction of the CT complex with the excess diene, the rate constant of which is virtually identical to that for the direct bimolecular cycloaddition. The conclusion is drawn for our case that there are more arguments against than arguments for the CT complex being a preorientation complex in the [4 + 2] cycloaddition.
    Zusätzliches Material: 3 Ill.
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  • 9
    Digitale Medien
    Digitale Medien
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 127 (1994), S. 2493-2498 
    ISSN: 0009-2940
    Schlagwort(e): Electrophilicity ; Ferrocenylmethylium ions ; Kinetics ; Chemistry ; Inorganic Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: Second-order rate constants for the reactions of the ferrocenylmethylium ions 2a - e with silyl enol ethers, allylsilanes, allylstannanes, and hydride donors have been determined photometrically and conductometrically in dichloromethane. The ferrocenylmethylium ions 2a - d (fc-CHR+, R = H, Me, Ph, An) are slightly stronger electrophiles than the tropylium ion, and their electrophilic reactivities depend only slightly on the nature of R. The bis(ferrocenyl)methylium ion 2e is a considerably weaker electrophile, comparable to the tricarbonyl(cyclohexadienyl)iron cation.
    Zusätzliches Material: 3 Ill.
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  • 10
    Digitale Medien
    Digitale Medien
    Weinheim : Wiley-Blackwell
    Advanced Materials 2 (1990), S. 174-179 
    ISSN: 0935-9648
    Schlagwort(e): Explosives ; Propellants ; Pyrotechnics ; Detonation Sensitivity ; Kinetics ; Chemistry ; Polymer and Materials Science
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie , Maschinenbau , Physik
    Zusätzliches Material: 3 Ill.
    Materialart: Digitale Medien
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  • 11
    ISSN: 1042-7147
    Schlagwort(e): Poly(vinyl pyridine) ; Iodine ; DDQ ; TCNQ ; Charge-transfer complexes ; Kinetics ; electronic absorption spectra ; Chemistry ; Polymer and Materials Science
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie , Maschinenbau
    Notizen: The kinetics of formation of charge transfer complexes of poly(4-vinyl pyridine), poly(2-vinyl pyridine), and poly(2-vinyl pyridine-co-styrene) with iodine, 7,7′,8,8′-tetracyanoquinodimethane and 2,3-dichloro-5,6-dicyano-1,4-benzoquinone has been studied using electronic absorption spectroscopy. The charge transfer complexes of analogous low molecular weight donors, namely 2- and 4-picolines with the same set of acceptors have also been investigated for comparison. The composition and the equilibrium constants of the charge transfer complexes have been obtained. The equilibrium constant of the polymeric complexes is found to be higher than that of analogous complexes of the low molecular weight donors. A new method for determining the rate constants of the association and dissociation of the equilibrium involving the charge transfer complex formation has been proposed. The rate constants vary with the concentration of the acceptor. It indicates that the charge transfer complexes undergo a further reaction and hence the observed rate constants are not true but apparent rate constants. The charge transfer complexes have also been investigated by electron paramagnetic resonance spectroscopy.
    Zusätzliches Material: 3 Ill.
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  • 12
    Digitale Medien
    Digitale Medien
    New York, NY [u.a.] : Wiley-Blackwell
    Molecular Reproduction and Development 36 (1993), S. 328-330 
    ISSN: 1040-452X
    Schlagwort(e): Sperm capacitation ; Acrosome reaction ; Kinetics ; Life and Medical Sciences ; Cell & Developmental Biology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie
    Notizen: One of the problems in assaying sperm capacitation is that live eggs mount a block to polyspermy at the zona pellucida. To circumvent this problem, researchers have started to use salt-stored eggs to assay sperm capacitation (Boatman et al., Gamete Res 19:19-29, 1988; Yoshimatsu et al., Gamete Res 21:115-126, 1988). These researchers have demonstrated that the zonae of salt-stored eggs were penetrable by capacitated sperm, but they did not examine whether the timing of penetration of fully capacitated sperm was altered. This report shows that zona penetration by fully capacitated sperm is delayed in both short-term salt-treated eggs (2 hr) and in eggs stored in salt for 〉2 days. These results indicate that the zona is modified when eggs are treated with a high-salt solution. © 1993 Wiley-Liss, Inc.
    Zusätzliches Material: 1 Tab.
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  • 13
    Digitale Medien
    Digitale Medien
    New York, NY [u.a.] : Wiley-Blackwell
    Advanced Materials for Optics and Electronics 2 (1993), S. 165-173 
    ISSN: 1057-9257
    Schlagwort(e): Thermal oxidation ; Kinetics ; Electrical properties ; Trichloroethane (TCA) ; Hydrogen chloride (HCl) ; Hydrogen/oxygen (H2/O2) ; VLSI ; Chemistry ; Polymer and Materials Science
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Elektrotechnik, Elektronik, Nachrichtentechnik , Physik
    Notizen: The oxidation of single-crystal silicon wafers has been investigated using an industrial thermal oxidation system. The growth characteristics and electrical properties of the oxides resulting from pure hydrogen/oxygen (H2/O2), trichloroethane/oxygen (TCA/O2) and hydrogen chlorid/oxygen (HCl/O2) mixtures have been investigated and compared. The addition of both HCl and TCA to oxygen produces higher growth rates and improved electrical characteristics. It is shown that the oxidation rate for TCA/O2 is approximately 30%-40% higher than for HCl/O2 and that comparable electrical properties can be readily obtained. A TCA/O2 ratio of 1 mol% gives the optimum process for VLSI applications, though 3 mol% HCl/O2 gives comparable results. It is suggested that the overall mechanisms governing the processes are similar. However, the TCA process is a safer and cleaner alternative because it generates HCl in situ in the oxidation chamber.
    Zusätzliches Material: 10 Ill.
    Materialart: Digitale Medien
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  • 14
    Digitale Medien
    Digitale Medien
    New York, NY [u.a.] : Wiley-Blackwell
    Microscopy Research and Technique 20 (1992), S. 95-101 
    ISSN: 1059-910X
    Schlagwort(e): Phosphatidylcholine ; Docosane ; Kinetics ; Phase transitions ; Life and Medical Sciences ; Cell & Developmental Biology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Allgemeine Naturwissenschaft
    Notizen: We describe a temperature-jump device that permits time-resolved studies of thin cryo-transmission electron microscopy specimens. The specimen is rapidly heated to induce a change in microstructure just prior to cryo-fixation. The apparatus consists of a xenon arc lamp equipped with a shutter controlled by timing circuitry, used in conjunction with an environmental specimen preparation chamber. The specimen is heated by exposure to focused light from the lamp, and then plunged into cryogen. Using a thermocouple constructed from an electron microscope grid, we show that temperature jumps of 30-60 K are achieved with exposure times of 150-450 milliseconds. Micrographs of dimyristoyl phosphatidylcholine (DMPC) vesicles and n-docosane films, subjected to these exposures, shew that the specimens are still at least 20-30 K above their initial temperature when they contact the cryogen. This method could be applied to a variety of biological and chemical systems which undergo structural changes activated by a rise in temperature.
    Zusätzliches Material: 3 Ill.
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  • 15
    ISSN: 0749-1581
    Schlagwort(e): Molar paramagnetic solvent NMR shifts ; Galvinoxyl ; Kinetics ; Amines ; Reaction mechanism ; Chemistry ; Analytical Chemistry and Spectroscopy
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: The molar paramagnetic solvent NMR shifts of galvinoxyl (1, G′) in toluene were measured at 34°C and found to be 2.21 and 2.39 ppm mol-1 for the aliphatic and the aromatic proton signals of toluene, respectively. The implications of the inequality of the two molar shifts are discussed. The paramagnetic solvent shift of G. in toluene in the presence of tertiary amines decays according to a first-order rate law. The apparent first-order rate constants were found to be linearly related to the initial concentration of the amine. The kobs vs. [R3N]0 regression lines in some cases exhibit a positive intercept, indicating the involvement of the solvent in the reaction. The logarithms of the second-order rate constants are shown to be linear with respect to the ionization potentials of the amines. The reaction products of galvinoxyl with n-Bu3N are hydrogalvinoxyl, GH and the enamine n-Bu2NCH=CHEt whereas, with N/N-dimethylaniline. the products are hydrogalvinoxyl and the hemiaminal ether of formaldehyde, derived from the combination of the radical PhN(Me)CH2. with G. through the oxygen of the latter. A mechanistic scheme is proposed involving a rate-determining electron-transfer step.
    Zusätzliches Material: 3 Ill.
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  • 16
    Digitale Medien
    Digitale Medien
    Chichester : Wiley-Blackwell
    Organic Magnetic Resonance 29 (1991), S. 36-39 
    ISSN: 0749-1581
    Schlagwort(e): NMR ; FeH2P[CH2CH2CH2P(CH3)2]3 ; Skeletal rearrangement ; Kinetics ; Inversion-transfer-recovery ; Chemistry ; Analytical Chemistry and Spectroscopy
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: The iron dihydride FeH2(PP3) [PP3 = P(CH2CH2CH2PMe2)3] is fluctional, with the terminal co-ordinated phos-phine groups undergoing intramolecular exchange in addition to the iron-bound hydrides. The exchange kinetics of the metal-bound hydrides was examined using a magnetization inversion-transfer-recovery method, and the activation energy was ca. 64 kJ mol-1 at 260 K. The effect of spin-spin coupling on the magnetization transfer was examined.
    Zusätzliches Material: 3 Ill.
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  • 17
    Digitale Medien
    Digitale Medien
    Chichester : Wiley-Blackwell
    Organic Magnetic Resonance 29 (1991), S. 509-512 
    ISSN: 0749-1581
    Schlagwort(e): 3H NMR ; Exchange rates ; Kinetic acidity ; Kinetics ; Chemistry ; Analytical Chemistry and Spectroscopy
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: The first application of tritium NMR spectroscopy to the direct observation of proton-exchange kinetics is described; this technique allows the study of milligram amounts of substrates and for substrates with multiple exchangeable positions. The examples include benzene and the ring and methyl positions of p-xylene reacting with cesium cyclohexylamide in cyclohexylamine, and the enolate positions of cyclohexanone and methyl 7,12-dihydroxy-3-ketocholan-24-oate reacting with heptafluorobutyric acid in dioxane.
    Zusätzliches Material: 2 Ill.
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  • 18
    Digitale Medien
    Digitale Medien
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1993 (1993), S. 131-136 
    ISSN: 0170-2041
    Schlagwort(e): Adpoc-protecting group ; Protecting groups ; Amino acids ; Peptides ; Kinetics ; Chemistry ; Organic Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: Investigations with Selective Deblocking Reagents for Adpoc-Protected Amino Acids and PeptidesSelective reagents for the removal of the Adpoc group have been developed. For this purpose several peptides containing tryptophan and N∊-Boc-lysine have been synthesized. Among several acidolytic reagents, 0.1 N HCl/TFEt/CHCl3 (1:9:1) and 50% HCOOH/TFEt/CHCl3 (1:9:1) show high selectivity especially for the N∊-tert-butyloxycarbonyl group of lysine. Cleavage rates are determined by HPLC and TLC.
    Zusätzliches Material: 3 Ill.
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  • 19
    Digitale Medien
    Digitale Medien
    Weinheim : Wiley-Blackwell
    Angewandte Chemie International Edition in English 20 (1981), S. 487-500 
    ISSN: 0570-0833
    Schlagwort(e): Kinetics ; Relaxation ; Analytical methods ; Relaxation ; NMR spectroscopy ; Chemistry ; General Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: Analysis of spin-lattice relaxation (T1) provides alternatives to the standard line shape procedures for the investigation of intramolecular reactions; furthermore it expands the NMR range at both the high and the low energy barrier limits. Dipole-dipole- and quadrupole-relaxation times are sensitive to very rapid processes such as methyl rotation. Analysis of relaxation in the rotating frame(T1ρ) provides kinetics for many sorts of processes, particularly those in the dynamic range that is too rapid for line shape methods. Saturation transfer and the coalescence of relaxation times at high temperatures can be used to measure high energy barriers. The scope and limitations of these methods are described.
    Zusätzliches Material: 1 Ill.
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  • 20
    Digitale Medien
    Digitale Medien
    Weinheim : Wiley-Blackwell
    Angewandte Chemie International Edition in English 22 (1983), S. 225-240 
    ISSN: 0570-0833
    Schlagwort(e): Kinetics ; Kinetics ; Chemistry ; General Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: The temperature dependence of the rate of chemical reactions has been known for a long time; very often it is characterized by the Arrhenius plot. However, kinetic methods that take this phenomenon into account in one measurement in a planned manner have been applied to reactions in solution only in isolated examples-with the exception of the temperature jump method developed by Eigen et al. for fast reactions, based on a stepped temperature program. A mathematical analysis, however, reveals to the chemist that from the point of view of information theory the course of the reaction rate versus time under conditions of constantly increasing temperature is the measured signal which should lead to the most effective understanding of the reaction mechanism. Analysis of the measured peaks, which may overlap, allows the characterization of reactions either in the solid state or in solution by “mechanistic coordinates”, which extend the concept of reaction order. Their behavior allows further experiments to be planned, enabling elementary steps to be eliminated. Each reacting system can be characterized kinetically by one series of experiments using different starting concentrations for each reactant and additionally, using different heating rates. The experimental verification of these considerations can be seen in ca. 1400 DTA and UV experiments for ca. 120 different systems. Furthermore, the example of the oscillating Belousov-Zhabotinsky reaction shows that “fast” reactions frequently may also be recognized. A test for proposed reaction mechanisms is provided by integration programs which allow immediate comparison between experimental and theoretical signal curves.
    Zusätzliches Material: 9 Ill.
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  • 21
    Digitale Medien
    Digitale Medien
    Weinheim : Wiley-Blackwell
    Angewandte Chemie International Edition in English 29 (1990), S. 1371-1384 
    ISSN: 0570-0833
    Schlagwort(e): Kinetics ; Addition ; Alkenes ; Reaction mechanisms ; Carbocations ; C-C coupling ; Chemistry ; General Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: The addition of carbenium ions to CC double bonds, a key step in many syntheses in organic and macromolecular chemistry, is analyzed using the Lewis acid promoted reactions of alkyl chlorides with alkenes as an example. Stereochemical and kinetic experiments suggest that the transition state is slightly bridged and product-like. Rearrangements of the carbenium ions that result from the electrophilic attack can be minimized by adding salts with nucleophilic counter ions. The thermodynamics of the addition reactions are analyzed, and the conditions necessary in order to observe the back reaction (i.e. the Grob fragmentation) are discussed. Multiparameter equations that predict rate constants are derived from kinetic studies on the reactivities of carbenium ions and alkenes. Reactivity-selectivity relationships over a reactivity range that covers eight orders of magnitude show that the structure of the transition state is only changed by variation of substituents in the immediate vicinity of the reaction center.
    Zusätzliches Material: 8 Ill.
    Materialart: Digitale Medien
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  • 22
    ISSN: 0570-0833
    Schlagwort(e): Defect chemistry ; Kinetics ; Solid-state reactions ; Semiconductors ; Heterogeneous catalysis ; Chemistry ; General Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: Within the last few decades - though with its beginnings traceable to as early as 60 years ago - a direction of research has developed almost unnoticed by the classical chemical disciplines, such that one can now recognize a chemistry within the solid state that is analogous to the long-familiar chemistry in the liquid state. It arises from those departures from the ideal structure that are thermodynamically unavoidable, the point defects, and is referred to as defect chemistry. It includes the description of ionic and electronic effects, and it considers diffusion as a special step of the overall reaction. This area of chemistry enables one to describe and treat in a unified way many apparently widely different phenomena such as ionic conduction in crystals, doping effects and p-n junctions in semiconductors, color centers in alkali metal halides, image development in photography, passivation and corrosion of metals, the kinetics of the synthesis and sintering of solid materials, the problems of rock formation during the earth's evolution, the mechanisms of gas sensors and high temperature fuel cells, the performance of photosentive electrodes, variations of the electron balance in high temperature superconductors, elementary processes of heterogeneous catalysis, nonequilibrium transitions and oscillations in semiconductors in electric fields, and many more. In such phenomena the equilibrium concentration of defects has an important double role: it not only determines the disorder and the departures from the stoichiometric composition in the equilibrium state, but also, together with the mobility as the kinetic parameter, is the key parameter concerning the rates of physical processes, which are the main subject of the present discussion. Following the account of the thermodynamic fundamentals in Part I, this second part of the review will be concerned with kinetic processes. These are essentially the equilibration processes (physical diffusion, electrical conduction, chemical diffusion, and reactions) that take place under the influence of chemical and electric driving forces. As in Part I, here again the general characteristics of defect chemistry will clearly emerge, including the coexistence of ionic and electronic charge carriers, and the importance of the spatial coordinates. The concluding section will discuss some special characteristics of nonlinear processes that are too often overlooked in solid-state studies.
    Zusätzliches Material: 22 Ill.
    Materialart: Digitale Medien
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  • 23
    Digitale Medien
    Digitale Medien
    Weinheim : Wiley-Blackwell
    Angewandte Chemie International Edition in English 33 (1994), S. 2131-2143 
    ISSN: 0570-0833
    Schlagwort(e): Electrochemistry ; Kinetics ; Electron transfer ; Chemistry ; General Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: Data for heterogeneous electron transfer reactions obtained in the last ten years have been examined within the context of contemporary theory. Special attention is focused on systems for which rate constants and activation parameters are available as functions of solvents and of temperataure. The role of reactant structure in deteriming the kinetic parameters is also considered. Double layer effects both at unmodified and modified electrodes are discussed in detail. Experimental techniques, especially those suited to measuring fast reactions, are also outlined.
    Zusätzliches Material: 3 Ill.
    Materialart: Digitale Medien
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  • 24
    Digitale Medien
    Digitale Medien
    Weinheim : Wiley-Blackwell
    Angewandte Chemie International Edition in English 19 (1980), S. 333-343 
    ISSN: 0570-0833
    Schlagwort(e): Kinetics ; Gas-phase reactions ; Computer chemistry ; Chemistry ; General Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: Modern digital methods and powerful computers make it possible to simulate the time behavior of chemical reactions. These calculations can be performed on systems containing an almost unlimited number of elementary reactions. Generally, however, the reaction models used should contain only those elementary reactions which describe the bulk of the conversion. Such a reaction model may be obtained by reduction of the complete set of elementary reactions. Another possibility is analysis of the chemical system starting from conditions ensuring a simple chemistry, which is generally the case at low temperatures and low conversions. The reaction model may then be extended into the range of the reaction variables (temperature, time) of interest. Mathematical simulations may be helpful during the development of the reaction model, and sometimes even decisive. These methods were applied to the pyrolysis of ethylbenzene and n-hexane, and to CO oxidation. They yield information on the reaction paths, the importance of particular elementary reactions, and reaction stability. Furthermore, quantitative data can be obtained concerning the influence of single elementary reactions on the product distribution. The sensitivity matrix shows, e.g., whether the determination of kinetic parameters of an elementary reaction from kinetic data of the overall reaction is possible in principle, and how high the accuracy of the rate constants should be for simulation of the reaction. Both results are important for modeling chemical reactions.
    Zusätzliches Material: 7 Ill.
    Materialart: Digitale Medien
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  • 25
    Publikationsdatum: 1990-08-10
    Beschreibung: The stimulation of phospholipase A2 by thrombin and type 2 (P2)-purinergic receptor agonists in Chinese hamster ovary cells is mediated by the G protein Gi. To delineate alpha chain regulatory regions responsible for control of phospholipase A2, chimeric cDNAs were constructed in which different lengths of the alpha subunit of Gs (alpha s) were replaced with the corresponding sequence of the Gi alpha subunit (alpha i2). When a carboxyl-terminal chimera alpha s-i(38), which has the last 38 amino acids of alpha s substituted with the last 36 residues of alpha i2, was expressed in Chinese hamster ovary cells, the receptor-stimulated phospholipase A2 activity was inhibited, although the chimera could still activate adenylyl cyclase. Thus, alpha s-i(38) is an active alpha s, but also a dominant negative alpha i molecule, indicating that the last 36 amino acids of alpha i2 are a critical domain for G protein regulation of phospholipase A2 activity.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Gupta, S K -- Diez, E -- Heasley, L E -- Osawa, S -- Johnson, G L -- DK37871/DK/NIDDK NIH HHS/ -- GM30324/GM/NIGMS NIH HHS/ -- New York, N.Y. -- Science. 1990 Aug 10;249(4969):662-6.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Division of Basic Sciences, National Jewish Center for Immunology and Respiratory Medicine, Denver, CO 80206.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/2166341" target="_blank"〉PubMed〈/a〉
    Schlagwort(e): Adenosine Triphosphate/pharmacology ; Animals ; Arachidonic Acid ; Arachidonic Acids/metabolism ; Cell Line ; Chlorides/pharmacology ; Enzyme Activation ; GTP-Binding Proteins/*genetics/metabolism ; Inositol Phosphates/metabolism ; Kinetics ; Lithium/pharmacology ; Lithium Chloride ; Macromolecular Substances ; *Mutation ; Phospholipases/*metabolism ; Phospholipases A/*metabolism ; Phospholipases A2 ; Receptors, Purinergic/drug effects/*physiology ; Restriction Mapping ; Thrombin/antagonists & inhibitors/*pharmacology ; Transfection
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    Thema: Biologie , Chemie und Pharmazie , Informatik , Medizin , Allgemeine Naturwissenschaft , Physik
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  • 26
    facet.materialart.
    Unbekannt
    American Association for the Advancement of Science (AAAS)
    Publikationsdatum: 1990-08-17
    Beschreibung: The transcription factor C/EBP uses a bipartite structural motif to bind DNA. Two protein chains dimerize through a set of amphipathic alpha helices termed the leucine zipper. Highly basic polypeptide regions emerge from the zipper to form a linked set of DNA contact surfaces. In the recently proposed a "scissors grip" model, the paired set of basic regions begin DNA contact at a central point and track in opposite directions along the major groove, forming a molecular clamp around DNA. This model predicts that C/EBP must undertake significant changes in protein conformation as it binds and releases DNA. The basic region of ligand-free C/EBP is highly sensitive to protease digestion. Pronounced resistance to proteolysis occurred when C/EBP associated with its specific DNA substrate. Sequencing of discrete proteolytic fragments showed that prominent sites for proteolysis occur at two junction points predicted by the "scissors grip" model. One junction corresponds to the cleft where the basic regions emerge from the leucine zipper. The other corresponds to a localized nonhelical segment that has been hypothesized to contain an N-cap and facilitate the sharp angulation necessary for the basic region to track continuously in the major groove of DNA.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Shuman, J D -- Vinson, C R -- McKnight, S L -- New York, N.Y. -- Science. 1990 Aug 17;249(4970):771-4.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Howard Hughes Research Laboratories, Department of Embryology, Baltimore, MD 21210.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/2202050" target="_blank"〉PubMed〈/a〉
    Schlagwort(e): Amino Acid Sequence ; Binding Sites ; CCAAT-Enhancer-Binding Proteins ; Chromatography, High Pressure Liquid ; DNA/*metabolism ; DNA-Binding Proteins/metabolism ; Kinetics ; Leucine ; Macromolecular Substances ; Models, Molecular ; Molecular Sequence Data ; Nuclear Proteins/*metabolism ; Peptide Fragments/metabolism ; Peptide Hydrolases/*metabolism ; Protein Conformation ; Transcription Factors/*metabolism ; Trypsin/metabolism
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    Thema: Biologie , Chemie und Pharmazie , Informatik , Medizin , Allgemeine Naturwissenschaft , Physik
    Standort Signatur Erwartet Verfügbarkeit
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  • 27
    facet.materialart.
    Unbekannt
    American Association for the Advancement of Science (AAAS)
    Publikationsdatum: 1990-04-06
    Beschreibung: The rate of release of guanine nucleotides from the ras proteins (Ras) is extremely slow in the presence of Mg2+. It seemed likely, therefore that a factor might exist to accelerate the release of guanosine diphosphate (GDP), and hence the exchange of GDP for guanosine triphosphate (GTP). Such a factor has now been discovered in rat brain cytosol. Brain cytosol was found to catalyze, by orders of magnitude, the release of guanine nucleotides from recombinant v-H-Ras protein bound with [alpha-32P]GDP. This effect occurred even in the presence of a large excess of Mg2+, but was destroyed by heat or by incubation of the cytosol for an hour at 37 degrees C in the absence of phosphatase inhibitors. The effect was observed with either v-H-Ras or c-H-Ras, but not with p25rab3A, a small G protein with about 30% similarity to Ras. The effect could not be mimicked by addition of recombinant Ras-GAP or purified GEF, a guanine nucleotide exchange factor involved in the regulation of eukaryotic protein synthesis. By gel filtration chromatography, the factor appears to possess a molecular size between 100,000 and 160,000 daltons. This protein (Ras-guanine nucleotide-releasing factor, or Ras-GRF) may be involved in the activation of p21ras.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Wolfman, A -- Macara, I G -- CA 43551/CA/NCI NIH HHS/ -- ES 01247/ES/NIEHS NIH HHS/ -- GM 41220/GM/NIGMS NIH HHS/ -- New York, N.Y. -- Science. 1990 Apr 6;248(4951):67-9.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Biophysics, University of Rochester Medical Center, NY 14642.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/2181667" target="_blank"〉PubMed〈/a〉
    Schlagwort(e): Animals ; Binding, Competitive ; Brain/metabolism ; Cholic Acids ; Cytosol/*metabolism ; Guanine Nucleotides/*metabolism ; Guanosine 5'-O-(3-Thiotriphosphate) ; Guanosine Diphosphate/*metabolism ; Guanosine Triphosphate/analogs & derivatives/metabolism ; Hot Temperature ; Immunosorbent Techniques ; Kinetics ; Magnesium Chloride/pharmacology ; Molecular Weight ; Proto-Oncogene Proteins/*metabolism ; Proto-Oncogene Proteins p21(ras) ; Rats ; Thionucleotides/metabolism
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    Thema: Biologie , Chemie und Pharmazie , Informatik , Medizin , Allgemeine Naturwissenschaft , Physik
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  • 28
    facet.materialart.
    Unbekannt
    American Association for the Advancement of Science (AAAS)
    Publikationsdatum: 1990-09-28
    Beschreibung: 〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Dusheck, J -- New York, N.Y. -- Science. 1990 Sep 28;249(4976):1494-5.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/2218487" target="_blank"〉PubMed〈/a〉
    Schlagwort(e): *Biological Evolution ; Congresses as Topic ; Female ; Humans ; Male ; Men ; United States ; *Women
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    Thema: Biologie , Chemie und Pharmazie , Informatik , Medizin , Allgemeine Naturwissenschaft , Physik
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  • 29
    facet.materialart.
    Unbekannt
    American Association for the Advancement of Science (AAAS)
    Publikationsdatum: 1990-09-21
    Beschreibung: Nonobese diabetic (NOD) mice develop an autoimmune form of diabetes, becoming hyperglycemic after 3 months of age. This process was accelerated by injecting young NOD mice with CD4+ islet-specific T cell clones derived from NOD mice. Overt diabetes developed in 10 of 19 experimental animals by 7 weeks of age, with the remaining mice showing marked signs of the disease in progress. Control mice did not become diabetic and had no significant pancreatic infiltration. This work demonstrates that a CD4 T cell clone is sufficient to initiate the disease process in the diabetes-prone NOD mouse.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Haskins, K -- McDuffie, M -- P01 DK40144/DK/NIDDK NIH HHS/ -- New York, N.Y. -- Science. 1990 Sep 21;249(4975):1433-6.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Barbara Davis Center for Childhood Diabetes, University of Colorado Health Sciences Center, Denver 80262.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/2205920" target="_blank"〉PubMed〈/a〉
    Schlagwort(e): Animals ; Antigens, CD4/analysis/*immunology ; Clone Cells ; Diabetes Mellitus, Experimental/*immunology/pathology ; Female ; Islets of Langerhans/*immunology/pathology ; Male ; Mice ; Mice, Inbred Strains ; Mice, Mutant Strains ; T-Lymphocytes/*immunology/transplantation
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    Thema: Biologie , Chemie und Pharmazie , Informatik , Medizin , Allgemeine Naturwissenschaft , Physik
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  • 30
    Publikationsdatum: 1990-11-30
    Beschreibung: Conducting gramicidin channels form predominantly by the transmembrane association of monomers, one from each side of a lipid bilayer. In single-channel experiments in planar bilayers the two gramicidin analogs, [Val1]gramicidin A (gA) and [4,4,4-F3-Val1]gramicidin A (F3gA), form dimeric channels that are structurally equivalent and have characteristically different conductances. When these gramicidins were added asymmetrically, one to each side of a preformed bilayer, the predominant channel type was the hybrid channel, formed between two chemically dissimilar monomers. These channels formed by the association of monomers residing in each half of the membrane. These results also indicate that the hydrophobic gramicidins are surprisingly membrane impermeant, a conclusion that was confirmed in experiments in which gA was added asymmetrically and symmetrically to preformed bilayers.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉O'Connell, A M -- Koeppe, R E 2nd -- Andersen, O S -- GM21342/GM/NIGMS NIH HHS/ -- GM34968/GM/NIGMS NIH HHS/ -- New York, N.Y. -- Science. 1990 Nov 30;250(4985):1256-9.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Physiology and Biophysics, Cornell University Medical College, New York, NY 10021.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/1700867" target="_blank"〉PubMed〈/a〉
    Schlagwort(e): Amino Acid Sequence ; Cell Membrane Permeability ; Chemistry, Physical ; Electric Conductivity ; Gramicidin/*chemistry/metabolism ; Ion Channels/*chemistry/physiology ; Kinetics ; Lipid Bilayers/*chemistry ; Macromolecular Substances ; Molecular Sequence Data ; Physicochemical Phenomena ; Protein Conformation
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    Thema: Biologie , Chemie und Pharmazie , Informatik , Medizin , Allgemeine Naturwissenschaft , Physik
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  • 31
    facet.materialart.
    Unbekannt
    American Association for the Advancement of Science (AAAS)
    Publikationsdatum: 1990-06-22
    Beschreibung: The vast repertoire of immunoglobulins and T cell receptors is generated, in part, by V(D)J recombination, a series of genomic rearrangements that occur specifically in developing lymphocytes. The recombination activating gene, RAG-1, which is a gene expressed exclusively in maturing lymphoid cells, was previously isolated. RAG-1 inefficiently induced V(D)J recombinase activity when transfected into fibroblasts, but cotransfection with an adjacent gene, RAG-2, has resulted in at least a 1000-fold increase in the frequency of recombination. The 2.1-kilobase RAG-2 complementary DNA encodes a putative protein of 527 amino acids whose sequence is unrelated to that of RAG-1. Like RAG-1, RAG-2 is conserved between species that carry out V(D)J recombination, and its expression pattern correlates precisely with that of V(D)J recombinase activity. In addition to being located just 8 kilobases apart, these convergently transcribed genes are unusual in that most, if not all, of their coding and 3' untranslated sequences are contained in single exons. RAG-1 and RAG-2 might activate the expression of the V(D)J recombinase but, more likely, they directly participate in the recombination reaction.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Oettinger, M A -- Schatz, D G -- Gorka, C -- Baltimore, D -- GM39458/GM/NIGMS NIH HHS/ -- New York, N.Y. -- Science. 1990 Jun 22;248(4962):1517-23.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Whitehead Institute for Biomedical Research, Cambridge, MA 02142.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/2360047" target="_blank"〉PubMed〈/a〉
    Schlagwort(e): Amino Acid Sequence ; Animals ; Base Sequence ; Biological Evolution ; Cattle ; Cell Line ; Chickens ; Cricetinae ; DNA/*genetics ; DNA Nucleotidyltransferases/*genetics ; *DNA-Binding Proteins ; Dogs ; Female ; *Gene Rearrangement, B-Lymphocyte ; *Gene Rearrangement, T-Lymphocyte ; *Homeodomain Proteins ; Humans ; Male ; Mice ; Molecular Sequence Data ; *Multigene Family ; Nuclear Proteins ; Nucleic Acid Hybridization ; Opossums ; Proteins/*genetics ; Rabbits ; Recombination, Genetic/*genetics ; Restriction Mapping ; Transfection ; Turtles ; VDJ Recombinases
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    Thema: Biologie , Chemie und Pharmazie , Informatik , Medizin , Allgemeine Naturwissenschaft , Physik
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  • 32
    Publikationsdatum: 1990-09-28
    Beschreibung: The erbB2 oncogene encodes a 185-kilodalton transmembrane protein whose sequence is similar to the epidermal growth factor receptor (EGFR). A 30-kilodalton factor (gp30) secreted from MDA-MB-231 human breast cancer cells was shown to be a ligand for p185erbB2. An antibody to EGFR abolished the tyrosine phosphorylation induced by EGF and transforming growth factor-alpha (TGF-alpha) but only partially blocked that produced by gp30 in SK-BR-3 breast cancer cells. In two cell lines that overexpress erbB2 but do not expresss EGFR (MDA-MB-453 breast cancer cells and a Chinese hamster ovary cell line that had been transfected with erbB2), phosphorylation of p185erbB2 was induced only by gp30. The gp30 specifically inhibited the growth of cells that overexpressed p185erbB2. An antibody to EGFR had no effect on the inhibition of SK-BR-3 cell colony formation obtained with gp30. Thus, it appeared that gp30 interacted directly with the EGFR and erbB2. Direct binding of gp30 to p185erbB2 was confirmed by binding competition experiments, where gp30 was found to displace the p185erbB2 binding of a specific antibody to p185erbB2. The evidence described here suggests that gp30 is a ligand for p185erbB2.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Lupu, R -- Colomer, R -- Zugmaier, G -- Sarup, J -- Shepard, M -- Slamon, D -- Lippman, M E -- New York, N.Y. -- Science. 1990 Sep 28;249(4976):1552-5.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Vincent T. Lombardi Cancer Research Center, Georgetown University Medical Center, Washington, DC 20007.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/2218496" target="_blank"〉PubMed〈/a〉
    Schlagwort(e): Animals ; Antibodies, Monoclonal ; Binding, Competitive ; Breast Neoplasms ; Cell Line ; Chromatography, Affinity ; Female ; Humans ; Kinetics ; Ligands ; Molecular Weight ; Phosphorylation ; Protein-Tyrosine Kinases/metabolism ; Proto-Oncogene Proteins/genetics/immunology/*metabolism ; Proto-Oncogenes ; Receptor, Epidermal Growth Factor/isolation & purification/*metabolism ; Transfection
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    Thema: Biologie , Chemie und Pharmazie , Informatik , Medizin , Allgemeine Naturwissenschaft , Physik
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  • 33
    facet.materialart.
    Unbekannt
    American Association for the Advancement of Science (AAAS)
    Publikationsdatum: 1990-05-04
    Beschreibung: The amino acid sequences of three fragments of cyanogen bromide-digested human placental inositol 1,2-cyclic phosphate 2-phosphohydrolase, an enzyme of the phosphatidylinositol signaling pathway, are identical to sequences within lipocortin III, a member of a family of homologous calcium- and phospholipid-binding proteins that do not have defined physiological functions. Lipocortin III has also been previously identified as placental anticoagulant protein III (PAP III) and calcimedin 35 alpha. Antibodies to PAP III detected PAP III and inositol 1,2-cyclic phosphate 2-phosphohydrolase with identical reactivity on immunoblotting. In addition, inositol 1,2-cyclic phosphate 2-phosphohydrolase was stimulated by the same acidic phospholipids that bind lipocortins.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Ross, T S -- Tait, J F -- Majerus, P W -- HLBI 14147/HL/NHLBI NIH HHS/ -- HLBI 16634/HL/NHLBI NIH HHS/ -- HLBI 40801/HL/NHLBI NIH HHS/ -- New York, N.Y. -- Science. 1990 May 4;248(4955):605-7.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Internal Medicine, Washington University School of Medicine, St Louis, MO 63110.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/2159184" target="_blank"〉PubMed〈/a〉
    Schlagwort(e): Amino Acid Sequence ; Annexin A3 ; Annexins ; Calcium-Binding Proteins/*genetics ; Female ; Humans ; Immunoblotting ; Kinetics ; Molecular Sequence Data ; Phosphoric Diester Hydrolases/*genetics/isolation & purification/metabolism ; Placenta/*enzymology ; Pregnancy
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    Thema: Biologie , Chemie und Pharmazie , Informatik , Medizin , Allgemeine Naturwissenschaft , Physik
    Standort Signatur Erwartet Verfügbarkeit
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  • 34
    Publikationsdatum: 1990-08-10
    Beschreibung: Somatic mutations in a subset of growth hormone (GH)-secreting pituitary tumors convert the gene for the alpha polypeptide chain (alpha s) of Gs into a putative oncogene, termed gsp. These mutations, which activate alpha s by inhibiting its guanosine triphosphatase (GTPase) activity, are found in codons for either of two amino acids, each of which is completely conserved in all known G protein alpha chains. The likelihood that similar mutations would activate other G proteins prompted a survey of human tumors for mutations that replace either of these two amino acids in other G protein alpha chain genes. The first gene so far tested, which encodes the alpha chain of Gi2, showed mutations that replaced arginine-179 with either cysteine or histidine in 3 of 11 tumors of the adrenal cortex and 3 of 10 endocrine tumors of the ovary. The mutant alpha i2 gene is a putative oncogene, referred to as gip2. In addition, gsp mutations were found in 18 of 42 GH-secreting pituitary tumors and in an autonomously functioning thyroid adenoma. These findings suggest that human tumors may harbor oncogenic mutations in various G protein alpha chain genes.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Lyons, J -- Landis, C A -- Harsh, G -- Vallar, L -- Grunewald, K -- Feichtinger, H -- Duh, Q Y -- Clark, O H -- Kawasaki, E -- Bourne, H R -- New York, N.Y. -- Science. 1990 Aug 10;249(4969):655-9.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Human Genetics, Cetus Corporation, Emeryville CA 94608.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/2116665" target="_blank"〉PubMed〈/a〉
    Schlagwort(e): Amino Acid Sequence ; Base Sequence ; DNA, Neoplasm/genetics ; Endocrine System Diseases/*genetics ; Female ; GTP Phosphohydrolases/genetics/metabolism ; GTP-Binding Proteins/*genetics/metabolism ; Humans ; Male ; Molecular Sequence Data ; *Mutation ; Neoplasms/*genetics ; Oligonucleotide Probes ; *Oncogenes ; Pituitary Neoplasms/*genetics ; Polymerase Chain Reaction
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    Thema: Biologie , Chemie und Pharmazie , Informatik , Medizin , Allgemeine Naturwissenschaft , Physik
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  • 35
    Publikationsdatum: 1990-07-20
    Beschreibung: Minor histocompatibility (H) antigens can be peptides derived from cellular proteins that are presented on the cell surface by major histocompatibility complex (MHC) class I molecules. This is similar to viral antigens, because in both cases cytotoxic T lymphocytes (CTLs) recognize artificially produced peptides loaded on target cells. Naturally processed minor H peptides were found to be similar to those artificial CTL-epitopes, as far as size and hydrophobicity is concerned. The peptides studied were isolated from a transfectant that expressed a model CTL-defined antigen, beta-galactosidase, from male cells that express H-Y, which has been known operationally since 1955, and from cells that express H-4, known since 1961.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Rotzschke, O -- Falk, K -- Wallny, H J -- Faath, S -- Rammensee, H G -- New York, N.Y. -- Science. 1990 Jul 20;249(4966):283-7.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Max-Planck-Institut fur Biologie, Abteilung Immungenetik, Tubingen, Federal Republic of Germany.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/1695760" target="_blank"〉PubMed〈/a〉
    Schlagwort(e): Amino Acid Sequence ; Animals ; Epitopes/isolation & purification ; Female ; H-Y Antigen/*analysis/immunology ; Male ; Mice ; Mice, Inbred Strains ; Minor Histocompatibility Antigens/*analysis/immunology ; Molecular Sequence Data ; Peptides/chemical synthesis ; Species Specificity ; Spleen/immunology ; T-Lymphocytes, Cytotoxic/*immunology
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    Thema: Biologie , Chemie und Pharmazie , Informatik , Medizin , Allgemeine Naturwissenschaft , Physik
    Standort Signatur Erwartet Verfügbarkeit
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  • 36
    Publikationsdatum: 1990-09-28
    Beschreibung: Heparin-binding growth factor-1 (HBGF-1) is an angiogenic polypeptide mitogen for mesoderm- and neuroectoderm-derived cells in vitro and remains biologically active after truncation of the amino-terminal domain (HBGF-1 alpha) of the HBGF-1 beta precursor. Polymerase chain reaction mutagenesis and prokaryotic expression systems were used to prepare a mutant of HBGF-1 alpha lacking a putative nuclear translocation sequence (amino acid residues 21 to 27; HBGF-1U). Although HBGF-1U retains its ability to bind to heparin, HBGF-1U fails to induce DNA synthesis and cell proliferation at concentrations sufficient to induce intracellular receptor-mediated tyrosine phosphorylation and c-fos expression. Attachment of the nuclear translocation sequence from yeast histone 2B at the amino terminus of HBGF-1U yields a chimeric polypeptide (HBGF-1U2) with mitogenic activity in vitro and indicates that nuclear translocation is important for this biological response.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Imamura, T -- Engleka, K -- Zhan, X -- Tokita, Y -- Forough, R -- Roeder, D -- Jackson, A -- Maier, J A -- Hla, T -- Maciag, T -- HL 32348/HL/NHLBI NIH HHS/ -- HL 35627/HL/NHLBI NIH HHS/ -- New York, N.Y. -- Science. 1990 Sep 28;249(4976):1567-70.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Laboratory of Molecular Biology, Jerome H. Holland Laboratory for the Biomedical Sciences, American Red Cross, Rockville, MD 20855.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/1699274" target="_blank"〉PubMed〈/a〉
    Schlagwort(e): Amino Acid Sequence ; Animals ; Base Sequence ; Binding, Competitive ; Cattle ; Cell Division/drug effects ; Cell Line ; Cell Nucleus/metabolism ; Cells, Cultured ; DNA Replication/drug effects ; Endothelium, Vascular/drug effects/metabolism ; Fibroblast Growth Factor 1/*genetics/metabolism/pharmacology ; Kinetics ; Mice ; Mitogens/pharmacology ; Molecular Sequence Data ; *Mutation ; Oligonucleotide Probes ; Receptors, Mitogen/metabolism ; Receptors, Vascular Endothelial Growth Factor ; Recombinant Proteins/metabolism/pharmacology ; Transcription, Genetic/drug effects
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    Thema: Biologie , Chemie und Pharmazie , Informatik , Medizin , Allgemeine Naturwissenschaft , Physik
    Standort Signatur Erwartet Verfügbarkeit
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  • 37
    facet.materialart.
    Unbekannt
    American Association for the Advancement of Science (AAAS)
    Publikationsdatum: 1990-06-29
    Beschreibung: Soluble and hydrophobic lipid breakdown products have a variety of important signaling roles in cells. Here sphingoid bases derived in cells from sphingolipid breakdown are shown to have a potent and direct effect in mediating calcium release from intracellular stores. Sphingosine must be enzymically converted within the cell to a product believed to be sphingosine-1-phosphate, which thereafter effects calcium release from a pool including the inositol 1,4,5-trisphosphate-sensitive calcium pool. The sensitivity, molecular specificity, and reversibility of the effect on calcium movements closely parallel sphingoid base-mediated inhibition of protein kinase C. Generation of sphingoid bases in cells may activate a dual signaling pathway involving regulation of calcium and protein kinase C, comparable perhaps to the phosphatidylinositol and calcium signaling pathway.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Ghosh, T K -- Bian, J -- Gill, D L -- NS19304/NS/NINDS NIH HHS/ -- New York, N.Y. -- Science. 1990 Jun 29;248(4963):1653-6.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Biological Chemistry, University of Maryland School of Medicine, Baltimore 21201.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/2163543" target="_blank"〉PubMed〈/a〉
    Schlagwort(e): Adenosine Diphosphate/pharmacology ; Animals ; Calcimycin/pharmacology ; Calcium/*metabolism ; Cell Line ; Kinetics ; Phosphoric Monoester Hydrolases/metabolism ; Phosphorylcholine/analogs & derivatives/pharmacology ; Protein Kinase C/metabolism ; Second Messenger Systems/drug effects ; Sphingosine/*analogs & derivatives/*pharmacology ; Thermodynamics
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    Thema: Biologie , Chemie und Pharmazie , Informatik , Medizin , Allgemeine Naturwissenschaft , Physik
    Standort Signatur Erwartet Verfügbarkeit
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  • 38
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    American Association for the Advancement of Science (AAAS)
    Publikationsdatum: 1990-10-12
    Beschreibung: Voltage-dependent ion channels are responsible for electrical signaling in neurons and other cells. The main classes of voltage-dependent channels (sodium-, calcium-, and potassium-selective channels) have closely related molecular structures. For one member of this superfamily, the transiently voltage-activated Shaker H4 potassium channel, specific amino acid residues have now been identified that affect channel blockade by the small ion tetraethylammonium, as well as the conduction of ions through the pore. Furthermore, variation at one of these amino acid positions among naturally occurring potassium channels may account for most of their differences in sensitivity to tetraethylammonium.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉MacKinnon, R -- Yellen, G -- GM 43949/GM/NIGMS NIH HHS/ -- New York, N.Y. -- Science. 1990 Oct 12;250(4978):276-9.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Cellular and Molecular Physiology, Harvard Medical School, Boston, MA 02115.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/2218530" target="_blank"〉PubMed〈/a〉
    Schlagwort(e): Amino Acid Sequence ; Animals ; Electric Conductivity ; Kinetics ; Membrane Potentials/drug effects ; Molecular Sequence Data ; Mutagenesis, Site-Directed ; Oligonucleotide Probes ; Potassium Channels/drug effects/genetics/*physiology ; Tetraethylammonium ; Tetraethylammonium Compounds/*pharmacology
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    Thema: Biologie , Chemie und Pharmazie , Informatik , Medizin , Allgemeine Naturwissenschaft , Physik
    Standort Signatur Erwartet Verfügbarkeit
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  • 39
    Publikationsdatum: 1990-02-16
    Beschreibung: Sulfonylurea-sensitive adenosine triphosphate (ATP)-regulated potassium (KATP) channels are present in brain cells and play a role in neurosecretion at nerve terminals. KATP channels in substantia nigra, a brain region that shows high sulfonylurea binding, are inactivated by high glucose concentrations and by antidiabetic sulfonylureas and are activated by ATP depletion and anoxia. KATP channel inhibition leads to activation of gamma-aminobutyric acid (GABA) release, whereas KATP channel activation leads to inhibition of GABA release. These channels may be involved in the response of the brain to hyper- and hypoglycemia (in diabetes) and ischemia or anoxia.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Amoroso, S -- Schmid-Antomarchi, H -- Fosset, M -- Lazdunski, M -- New York, N.Y. -- Science. 1990 Feb 16;247(4944):852-4.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Institut de Pharmacologie Moleculaire et Cellulaire, UPR 411 du CNRS, Valbonne, France.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/2305257" target="_blank"〉PubMed〈/a〉
    Schlagwort(e): Adenosine Triphosphate/*physiology ; Animals ; Cell Hypoxia ; Deoxyglucose/pharmacology ; Glucose/metabolism/*pharmacology ; Hypoglycemic Agents/*pharmacology ; In Vitro Techniques ; Kinetics ; Oligomycins/pharmacology ; Potassium/pharmacology ; Potassium Channels/drug effects/*physiology ; Rubidium/metabolism ; Structure-Activity Relationship ; Substantia Nigra/drug effects/*physiology ; gamma-Aminobutyric Acid/*metabolism
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    Thema: Biologie , Chemie und Pharmazie , Informatik , Medizin , Allgemeine Naturwissenschaft , Physik
    Standort Signatur Erwartet Verfügbarkeit
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  • 40
    Publikationsdatum: 1990-05-04
    Beschreibung: Platelet-derived growth factor (PDGF) stimulates phospholipase C (PLC) activity and the phosphorylation of the gamma isozyme of PLC (PLC-gamma) in vitro and in living cells. The role of PLC-gamma in the phosphoinositide signaling pathway was addressed by examining the effect of overexpression of PLC-gamma on cellular responses to PDGF. Overexpression of PLC-gamma correlated with PDGF-induced tyrosine phosphorylation of PLC-gamma and with PDGF-induced breakdown of phosphatidylinositol 4,5-bisphosphate (PIP2). However, neither bradykinin- nor lysophosphatidic acid-induced phosphoinositide metabolism was enhanced in the transfected cells, suggesting that the G protein-coupled phosphoinositide responses to these ligands are mediated by other PLC isozymes. The enhanced PDGF-induced generation of inositol trisphosphate (IP3) did not enhance intracellular calcium signaling or influence PDGF-induced DNA synthesis. Thus, enzymes other than PLC-gamma may limit PDGF-induced calcium signaling and DNA synthesis. Alternatively, PDGF-induced calcium signaling and DNA synthesis may use biochemical pathways other than phosphoinositide metabolism for signal transduction.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Margolis, B -- Zilberstein, A -- Franks, C -- Felder, S -- Kremer, S -- Ullrich, A -- Rhee, S G -- Skorecki, K -- Schlessinger, J -- New York, N.Y. -- Science. 1990 May 4;248(4955):607-10.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Rorer Biotechnology, King of Prussia, PA 19406.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/2333512" target="_blank"〉PubMed〈/a〉
    Schlagwort(e): Animals ; Calcium/physiology ; Cattle ; Cell Division/*drug effects ; Cells, Cultured ; DNA Replication/drug effects ; Genetic Vectors ; Inositol Phosphates/metabolism ; Isoenzymes/biosynthesis/*genetics/metabolism ; Kinetics ; Mice ; Platelet-Derived Growth Factor/*pharmacology ; Second Messenger Systems/*drug effects ; Transfection ; Type C Phospholipases/biosynthesis/*genetics/metabolism
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    Thema: Biologie , Chemie und Pharmazie , Informatik , Medizin , Allgemeine Naturwissenschaft , Physik
    Standort Signatur Erwartet Verfügbarkeit
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  • 41
    facet.materialart.
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    American Association for the Advancement of Science (AAAS)
    Publikationsdatum: 1990-02-09
    Beschreibung: Gene mutation in vivo in human T lymphocytes appears to occur preferentially in dividing cells. Individuals with multiple sclerosis (MS) are assumed to have one or more populations of diving T cells that are being stimulated by autoantigens. Mutant T cell clones from MS patients were isolated and tested for reactivity to myelin basic protein, an antigen that is thought to participate in the induction of the disease. The hypoxanthine guanine phosphoribosyltransferase (hprt) clonal assay was used to determine mutant frequency values in MS patients with chronic progressive disease. Eleven of 258 thioguanine-resistant (hprt-) T cell clones from five of the six MS patients who were tested proliferated in response to human myelin basic protein without prior in vitro exposure to this antigen. No wild-type clones from these patients, nor any hprt- or wild-type clones from three healthy individuals responded to myelin basic protein. Thus, T cell clones that react with myelin basic protein can be isolated from the peripheral blood of MS patients.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Allegretta, M -- Nicklas, J A -- Sriram, S -- Albertini, R J -- CA30688-07/CA/NCI NIH HHS/ -- NS00849/NS/NINDS NIH HHS/ -- New York, N.Y. -- Science. 1990 Feb 9;247(4943):718-21.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Genetics Laboratory, University of Vermont, Burlington 05401.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/1689076" target="_blank"〉PubMed〈/a〉
    Schlagwort(e): Adult ; Autoantigens/immunology ; Cell Division ; Clone Cells/immunology ; Female ; Humans ; Hypoxanthine Phosphoribosyltransferase/genetics ; Male ; Middle Aged ; Multiple Sclerosis/genetics/*immunology ; Mutation ; Myelin Basic Protein/*immunology ; T-Lymphocytes/drug effects/*immunology ; Thioguanine/pharmacology ; X Chromosome
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    Thema: Biologie , Chemie und Pharmazie , Informatik , Medizin , Allgemeine Naturwissenschaft , Physik
    Standort Signatur Erwartet Verfügbarkeit
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  • 42
    facet.materialart.
    Unbekannt
    American Association for the Advancement of Science (AAAS)
    Publikationsdatum: 1990-01-12
    Beschreibung: 〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Allen, H L -- Iversen, L L -- New York, N.Y. -- Science. 1990 Jan 12;247(4939):221.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Merck Sharp & Dohme Research Laboratories, West Point, PA 19486.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/2403696" target="_blank"〉PubMed〈/a〉
    Schlagwort(e): Animals ; Cerebral Cortex/drug effects/*ultrastructure ; Dibenzocycloheptenes/administration & dosage/*pharmacology ; Dizocilpine Maleate ; Male ; Neurons/drug effects/*ultrastructure ; Phencyclidine/*pharmacology ; Rats ; Vacuoles/drug effects
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    Thema: Biologie , Chemie und Pharmazie , Informatik , Medizin , Allgemeine Naturwissenschaft , Physik
    Standort Signatur Erwartet Verfügbarkeit
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  • 43
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    Unbekannt
    American Association for the Advancement of Science (AAAS)
    Publikationsdatum: 1990-11-16
    Beschreibung: 〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Marshall, E -- New York, N.Y. -- Science. 1990 Nov 16;250(4983):900-2.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/2237436" target="_blank"〉PubMed〈/a〉
    Schlagwort(e): Adult ; Aged ; Female ; Humans ; Male ; Middle Aged ; Neoplasms/*mortality ; United States
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    Thema: Biologie , Chemie und Pharmazie , Informatik , Medizin , Allgemeine Naturwissenschaft , Physik
    Standort Signatur Erwartet Verfügbarkeit
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  • 44
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    American Association for the Advancement of Science (AAAS)
    Publikationsdatum: 1990-07-20
    Beschreibung: 〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Schneiderman, M -- Davis, D L -- Wagener, D K -- New York, N.Y. -- Science. 1990 Jul 20;249(4966):228-9.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/2374921" target="_blank"〉PubMed〈/a〉
    Schlagwort(e): African Americans ; European Continental Ancestry Group ; Female ; Humans ; Lung Neoplasms/mortality ; Male ; Prevalence ; Smoking/*epidemiology ; United States
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    Thema: Biologie , Chemie und Pharmazie , Informatik , Medizin , Allgemeine Naturwissenschaft , Physik
    Standort Signatur Erwartet Verfügbarkeit
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  • 45
    facet.materialart.
    Unbekannt
    American Association for the Advancement of Science (AAAS)
    Publikationsdatum: 1990-11-09
    Beschreibung: Deletion of chromosome 11p13 in humans produces the WAGR syndrome, consisting of aniridia (an absence or malformation of the iris), Wilms tumor (nephroblastoma), genitourinary malformations, and mental retardation. An interspecies backcross between Mus musculus/domesticus and Mus spretus was made in order to map the homologous chromosomal region in the mouse genome and to define an animal model of this syndrome. Nine evolutionarily conserved DNA clones from proximal human 11p were localized on mouse chromosome 2 near Small-eyes (Sey), a semidominant mutation that is phenotypically similar to aniridia. Analysis of Dickie's Small-eye (SeyDey), a poorly viable allele that has pleiotropic effects, revealed the deletion of three clones, f3, f8, and k13, which encompass the aniridia (AN2) and Wilms tumor susceptibility genes in man. Unlike their human counterparts, SeyDey/+ mice do not develop nephroblastomas. These findings suggest that the Small-eye defect is genetically equivalent to human aniridia, but that loss of the murine homolog of the Wilms tumor gene is not sufficient for tumor initiation. A comparison among Sey alleles suggests that the AN2 gene product is required for induction of the lens and nasal placodes.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Glaser, T -- Lane, J -- Housman, D -- 2 T32 GMO7753-11/GM/NIGMS NIH HHS/ -- GM27882/GM/NIGMS NIH HHS/ -- T32 GM007753/GM/NIGMS NIH HHS/ -- New York, N.Y. -- Science. 1990 Nov 9;250(4982):823-7.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Center for Cancer Research, Massachusetts Institute of Technology, Cambridge 02139.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/2173141" target="_blank"〉PubMed〈/a〉
    Schlagwort(e): Animals ; Aniridia/*genetics ; Blotting, Southern ; Chromosome Deletion ; Chromosome Mapping ; DNA/analysis ; *Disease Models, Animal ; Eye/embryology/pathology ; Female ; Genes, Wilms Tumor/*genetics ; Genetic Markers ; Kidney Neoplasms/*genetics ; Male ; Mice ; Mice, Inbred C3H ; Mice, Inbred C57BL ; Muridae ; Mutation ; Phenotype ; Polymorphism, Genetic ; Syndrome ; Wilms Tumor/*genetics
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    Thema: Biologie , Chemie und Pharmazie , Informatik , Medizin , Allgemeine Naturwissenschaft , Physik
    Standort Signatur Erwartet Verfügbarkeit
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  • 46
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    American Association for the Advancement of Science (AAAS)
    Publikationsdatum: 1990-08-17
    Beschreibung: An antibody elicited to a distorted N-methyl porphyrin catalyzed metal ion chelation by the planar porphyrin. At fixed Zn2+ and Cu2+ concentrations, the antibody-catalyzed reaction showed saturation kinetics with respect to the substrate mesoporphyrin IX (2) and was inhibited by the hapten, N-methylmesoporphyrin IX (1). The turnover number of 80 hour-1 for antibody-catalyzed metallation of 2 with Zn2+ compares with an estimated value of 800 hour-1 for ferrochelatase. The antibody also catalyzed the insertion of Co2+ and Mn2+ into 2, but it did not catalyze the metallation of protoporphyrin IX (3) or deuteroporphyrin IX (4). The antibody has high affinity for several metalloporphyrins, suggesting an approach to developing antibody-heme catalysts for redox or electron transfer reactions.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Cochran, A G -- Schultz, P G -- New York, N.Y. -- Science. 1990 Aug 17;249(4970):781-3.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Chemistry, University of California, Berkeley 94720.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/2389144" target="_blank"〉PubMed〈/a〉
    Schlagwort(e): Antibodies/*metabolism ; Antigens/immunology ; Catalysis ; Cobalt/metabolism ; Copper/metabolism ; Ferrochelatase/metabolism ; Kinetics ; Manganese/metabolism ; Mesoporphyrins/immunology/metabolism ; Metals/*metabolism ; Porphyrins/*metabolism ; Zinc/metabolism
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    Thema: Biologie , Chemie und Pharmazie , Informatik , Medizin , Allgemeine Naturwissenschaft , Physik
    Standort Signatur Erwartet Verfügbarkeit
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  • 47
    facet.materialart.
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    American Association for the Advancement of Science (AAAS)
    Publikationsdatum: 1990-11-23
    Beschreibung: 〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Martinez, F -- Poet, T S -- Watson, R R -- New York, N.Y. -- Science. 1990 Nov 23;250(4984):1070.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/2251495" target="_blank"〉PubMed〈/a〉
    Schlagwort(e): Animals ; Cocaine/metabolism/pharmacokinetics ; Hair/*chemistry/metabolism ; Humans ; Male ; Mice ; Morphine/metabolism/pharmacokinetics ; *Substance Abuse Detection
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    Thema: Biologie , Chemie und Pharmazie , Informatik , Medizin , Allgemeine Naturwissenschaft , Physik
    Standort Signatur Erwartet Verfügbarkeit
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  • 48
    Publikationsdatum: 1991-03-08
    Beschreibung: The two mouse genes, En-1 and En-2, that are homologs of the Drosophila segmentation gene engrailed, show overlapping spatially restricted patterns of expression in the neural tube during embryogenesis, suggestive of a role in regional specification. Mice homozygous for a targeted mutation that deletes the homeobox were viable and showed no obvious defects in embryonic development. This may be due to functional redundancy of En-2 and the related En-1 gene product during embryogenesis. Consistent with this hypothesis, the mutant mice showed abnormal foliation in the adult cerebellum, where En-2, and not En-1, is normally expressed.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Joyner, A L -- Herrup, K -- Auerbach, B A -- Davis, C A -- Rossant, J -- HD25334/HD/NICHD NIH HHS/ -- NS18381/NS/NINDS NIH HHS/ -- NS20591/NS/NINDS NIH HHS/ -- New York, N.Y. -- Science. 1991 Mar 8;251(4998):1239-43.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Samuel Lunenfeld Research Institute, Mount Sinai Hospital, Toronto, Ontario, Canada.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/1672471" target="_blank"〉PubMed〈/a〉
    Schlagwort(e): Animals ; Blastocyst ; Cell Line ; Cerebellum/*anatomy & histology/embryology/pathology ; Chimera ; *Chromosome Deletion ; Female ; *Genes, Homeobox ; Male ; Mice ; Mice, Inbred BALB C ; Mice, Inbred C57BL ; Nervous System/embryology ; Phenotype
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    Thema: Biologie , Chemie und Pharmazie , Informatik , Medizin , Allgemeine Naturwissenschaft , Physik
    Standort Signatur Erwartet Verfügbarkeit
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  • 49
    facet.materialart.
    Unbekannt
    American Association for the Advancement of Science (AAAS)
    Publikationsdatum: 1991-08-23
    Beschreibung: The evolutionary significance of protein polymorphisms has long been debated. Exponents of the balanced theory advocate that selection operates to maintain polymorphisms, whereas the neoclassical school argues that most genetic variation is neutral. Some studies have suggested that protein polymorphisms are not neutral, but their significance has been questioned because one cannot eliminate the possibility that linked loci were responsible for the observed differences. Evidence is presented that an enzymatic phenotype can affect carbon flow through a metabolic pathway. Glucose flux differences between lactate dehydrogenase-B phenotypes of Fundulus heteroclitus were reversed by substituting the Ldh-B gene product of one homozygous genotype with that of another.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉DiMichele, L -- Paynter, K T -- Powers, D A -- New York, N.Y. -- Science. 1991 Aug 23;253(5022):898-900.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Wildlife and Fisheries Sciences, Texas A&M University, College Station 77843.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/1876847" target="_blank"〉PubMed〈/a〉
    Schlagwort(e): Animals ; Blastocyst/enzymology ; Genotype ; Glucose/metabolism ; Glycolysis ; Isoenzymes ; Killifishes/embryology/*genetics/metabolism ; Kinetics ; L-Lactate Dehydrogenase/*genetics/metabolism ; Lactates/metabolism ; Lactic Acid ; Microinjections ; Phenotype ; Swine
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    Thema: Biologie , Chemie und Pharmazie , Informatik , Medizin , Allgemeine Naturwissenschaft , Physik
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  • 50
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    Unbekannt
    American Association for the Advancement of Science (AAAS)
    Publikationsdatum: 1991-09-20
    Beschreibung: CD45 is a leukocyte-specific, transmembrane protein tyrosine phosphatase (PTPase) required for T cell responsiveness. How the activity of PTPases is regulated in vivo is unclear. Treatment of murine thymocytes and a variety of murine T cell lines with the calcium ionophore ionomycin decreased CD45 PTPase activity. Ionomycin treatment also led to a decreased phosphorylation of serine residues in CD45. These results indicate that increased intracellular calcium modulates CD45 PTPase activity, demonstrating regulation of CD45 PTPase activity in vivo, and also implicate serine dephosphorylation as a possible mechanism.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Ostergaard, H L -- Trowbridge, I S -- CA-17733/CA/NCI NIH HHS/ -- New York, N.Y. -- Science. 1991 Sep 20;253(5026):1423-5.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Cancer Biology, Salk Institute, San Diego, CA 92186.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/1654595" target="_blank"〉PubMed〈/a〉
    Schlagwort(e): Animals ; Antigens, CD/*metabolism ; Antigens, CD45 ; Cell Line ; Histocompatibility Antigens/*metabolism ; Ionomycin/*pharmacology ; Kinetics ; Mice ; Mice, Inbred BALB C ; Phosphoprotein Phosphatases/*metabolism ; Protein Tyrosine Phosphatases ; Spleen/drug effects/enzymology/immunology ; T-Lymphocytes/drug effects/*enzymology/immunology ; Thymus Gland/immunology
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  • 51
    Publikationsdatum: 1991-05-03
    Beschreibung: A transition state analogue was used to produce a mouse antibody that catalyzes transesterification in water. The antibody behaves as a highly efficient catalyst with a covalent intermediate and the characteristic of induced fit. While some features of the catalytic pathway were programmed when the hapten was designed and reflect favorable substrate-antibody interactions, other features are a manifestation of the chemical potential of antibody diversity. The fact that antibodies recapitulate mechanisms and pathways previously thought to be a characteristic of highly evolved enzymes suggests that once an appropriate binding cavity is achieved, reaction pathways commensurate with the intrinsic chemical potential of proteins ensue.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Wirsching, P -- Ashley, J A -- Benkovic, S J -- Janda, K D -- Lerner, R A -- GM43858-01/GM/NIGMS NIH HHS/ -- New York, N.Y. -- Science. 1991 May 3;252(5006):680-5.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Chemistry, Scripps Research Institute, La Jolla, CA 92037.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/2024120" target="_blank"〉PubMed〈/a〉
    Schlagwort(e): Acylation ; Alcohols/metabolism ; Animals ; Antibodies, Monoclonal/immunology/*metabolism ; Antibody Specificity ; Binding Sites, Antibody ; *Catalysis ; Enzymes/metabolism ; Esterification ; Haptens ; Kinetics ; Mice ; Water
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    Thema: Biologie , Chemie und Pharmazie , Informatik , Medizin , Allgemeine Naturwissenschaft , Physik
    Standort Signatur Erwartet Verfügbarkeit
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  • 52
    Publikationsdatum: 1991-12-20
    Beschreibung: Rap1A is a low molecular weight guanosine triphosphate (GTP)-binding protein in human neutrophil membranes whose cellular function is unknown. Rap1A was found to form stoichiometric complexes with the cytochrome b558 component of the phagocyte nicotinamide adenine dinucleotide phosphate (NADPH) oxidase system. The (guanosine-5'-O-(3-thiotriphosphate) (GTP-gamma-S)-bound form of Rap1A bound more tightly to cytochrome b558 than did the guanosine diphosphate-bound form. No complex formation was observed between cytochrome b558 and H-Ras-GTP-gamma-S or Rap1A-GTP-gamma-S that had been heat-inactivated, nor between Rap1A-GTP-gamma-S and hydrophobic proteins serving as controls. Complex formation between Rap1A-GTP-gamma-S and cytochrome b558 was inhibited by phosphorylation of Rap1A with cyclic adenosine monophosphate (cAMP)-dependent protein kinase. These observations suggest that Rap1A may participate in the structure or regulation of the NADPH oxidase system and that this function of the Rap1A protein may be altered by phosphorylation.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Bokoch, G M -- Quilliam, L A -- Bohl, B P -- Jesaitis, A J -- Quinn, M T -- 5RO126711/PHS HHS/ -- GM39434/GM/NIGMS NIH HHS/ -- GM44428/GM/NIGMS NIH HHS/ -- New York, N.Y. -- Science. 1991 Dec 20;254(5039):1794-6.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Immunology, Scripps Research Institute, La Jolla, CA 92037.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/1763330" target="_blank"〉PubMed〈/a〉
    Schlagwort(e): Binding Sites ; Chromatography, Gel ; Cytochrome b Group/isolation & purification/*metabolism ; GTP-Binding Proteins/antagonists & inhibitors/isolation & ; purification/*metabolism ; Guanosine 5'-O-(3-Thiotriphosphate)/metabolism ; Humans ; Kinetics ; Macromolecular Substances ; NADH, NADPH Oxidoreductases/*metabolism ; NADPH Oxidase ; Neutrophils/enzymology ; Phosphorylation ; Protein Binding ; Protein Kinase C/metabolism ; Proto-Oncogene Proteins/metabolism ; Recombinant Proteins/antagonists & inhibitors/isolation & purification/metabolism ; rap GTP-Binding Proteins
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    Standort Signatur Erwartet Verfügbarkeit
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  • 53
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    Unbekannt
    American Association for the Advancement of Science (AAAS)
    Publikationsdatum: 1991-03-08
    Beschreibung: Engagement of the antigen-specific receptor (TCR) of CD4+ T lymphocytes without a second (costimulatory) signal prevents the subsequent production of interleukin-2 (IL-2) by these cells. Because IL-2 is a key immunoregulatory lymphokine and is also produced by a subset of CD8+ T cells that are able to kill target cells, the effect of engaging the TCR of one such clone in the absence of costimulatory signals was examined. The capacity for TCR-dependent IL-2 production was lost, indicating comparable costimulator-dependent signaling requirements for IL-2 production in CD4+ and CD8+ T cells. However, TCR-mediated cytotoxicity was not impaired, implying that costimulation is required for only certain TCR-dependent effector functions.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Otten, G R -- Germain, R N -- New York, N.Y. -- Science. 1991 Mar 8;251(4998):1228-31.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Lymphocyte Biology Section, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/1900952" target="_blank"〉PubMed〈/a〉
    Schlagwort(e): Animals ; Antibodies, Monoclonal/immunology ; Antigen-Presenting Cells/immunology ; Antigens, CD8 ; Antigens, Differentiation, T-Lymphocyte/*immunology ; Female ; Interleukin-2/biosynthesis/*physiology ; Kinetics ; Lymphocyte Activation ; Mice ; Mice, Inbred Strains ; Ovalbumin/immunology ; Rats ; Receptors, Antigen, T-Cell/*immunology ; Spleen/immunology/radiation effects ; T-Lymphocytes/*immunology
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    Thema: Biologie , Chemie und Pharmazie , Informatik , Medizin , Allgemeine Naturwissenschaft , Physik
    Standort Signatur Erwartet Verfügbarkeit
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  • 54
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    American Association for the Advancement of Science (AAAS)
    Publikationsdatum: 1991-06-07
    Beschreibung: 〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Palca, J -- New York, N.Y. -- Science. 1991 Jun 7;252(5011):1369.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/2047847" target="_blank"〉PubMed〈/a〉
    Schlagwort(e): *Hiv ; History, 20th Century ; Humans ; Male ; National Institutes of Health (U.S.) ; United States ; Virus Cultivation
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    Thema: Biologie , Chemie und Pharmazie , Informatik , Medizin , Allgemeine Naturwissenschaft , Physik
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  • 55
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    American Association for the Advancement of Science (AAAS)
    Publikationsdatum: 1991-03-01
    Beschreibung: In 1921 it was discovered that the sexual fate of Drosophila is determined by the ratio of X chromosomes to sets of autosomes. Only recently has it been found that the X chromosome to autosome (X:A) ratio is communicated in part by the dose of sisterless-b (sis-b), an X-linked genetic element located within the achaete-scute complex of genes involved in neurogenesis. In this report, the molecular nature of the primary sex determination signal and its relation to these proneural genes was determined by analysis of sis-b+ germline transformants. The sis-b+ function is confered by protein T4, a member of the helix-loop-helix family of transcription factors. Although T4 is shared by sis-b and scute-alpha, the regulatory regions of sis-b, which control T4 expression in sex determination, are both separable from and simpler than those of scute-alpha, which control T4 expression in neurogenesis. Dose-sensitive cooperative interactions in the assembly or binding of sis-dependent transcription factors may directly determine the activity of the female-specific promoter of Sex-lethal, the master regulator of sexual development. In this model there is no need to invoke the existence of analogous autosomal negative regulators of Sex-lethal.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Erickson, J W -- Cline, T W -- GM 23468/GM/NIGMS NIH HHS/ -- New York, N.Y. -- Science. 1991 Mar 1;251(4997):1071-4.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Molecular and Cell Biology, University of California, Berkeley 94720.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/1900130" target="_blank"〉PubMed〈/a〉
    Schlagwort(e): Animals ; Animals, Genetically Modified ; DNA Mutational Analysis ; Dosage Compensation, Genetic ; Drosophila melanogaster/*genetics ; Female ; Genes ; Genes, Lethal ; Male ; *Nervous System Physiological Phenomena ; Restriction Mapping ; *Sex Determination Analysis ; Transcription, Genetic ; X Chromosome/physiology
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    Standort Signatur Erwartet Verfügbarkeit
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  • 56
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    American Association for the Advancement of Science (AAAS)
    Publikationsdatum: 1991-09-27
    Beschreibung: Dihydropyridine-sensitive voltage-dependent L-type calcium channels are critical to excitation-secretion and excitation-contraction coupling. The channel molecule is a complex of the main, pore-forming subunit alpha 1 and four additional subunits: alpha 2, delta, beta, and gamma (alpha 2 and delta are encoded by a single messenger RNA). The alpha 1 subunit messenger RNA alone directs expression of functional calcium channels in Xenopus oocytes, and coexpression of the alpha 2/delta and beta subunits enhances the amplitude of the current. The alpha 2, delta, and gamma subunits also have pronounced effects on its macroscopic characteristics, such as kinetics, voltage dependence of activation and inactivation, and enhancement by a dihydropyridine agonist. In some cases, specific modulatory functions can be assigned to individual subunits, whereas in other cases the different subunits appear to act in concert to modulate the properties of the channel.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Singer, D -- Biel, M -- Lotan, I -- Flockerzi, V -- Hofmann, F -- Dascal, N -- New York, N.Y. -- Science. 1991 Sep 27;253(5027):1553-7.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Physiology and Pharmacology, Sackler School of Medicine, Tel Aviv University, Ramat Aviv, Israel.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/1716787" target="_blank"〉PubMed〈/a〉
    Schlagwort(e): 3-Pyridinecarboxylic acid, ; 1,4-dihydro-2,6-dimethyl-5-nitro-4-(2-(trifluoromethyl)phenyl)-, Methyl ; ester/pharmacology ; Animals ; Barium/pharmacology ; *Barium Compounds ; Cadmium/pharmacology ; Cadmium Chloride ; Calcium Channels/drug effects/genetics/*physiology ; *Chlorides ; Heart/physiology ; Kinetics ; Macromolecular Substances ; Membrane Potentials/drug effects ; Oocytes/physiology ; RNA, Messenger/genetics ; Xenopus
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    Thema: Biologie , Chemie und Pharmazie , Informatik , Medizin , Allgemeine Naturwissenschaft , Physik
    Standort Signatur Erwartet Verfügbarkeit
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  • 57
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    American Association for the Advancement of Science (AAAS)
    Publikationsdatum: 1991-02-01
    Beschreibung: Rhodopsin and the visual pigments are a distinct group within the family of G-protein-linked receptors in that they have a covalently bound ligand, the 11-cis-retinal chromophore, whereas all of the other receptors bind their agonists through noncovalent interactions. The retinal chromophore in rhodopsin is bound by means of a protonated Schiff base linkage to the epsilon-amino group of Lys-296. Two rhodopsin mutants have been constructed, K296G and K296A, in which the covalent linkage to the chromophore is removed. Both mutants form a pigment with an absorption spectrum close to that of the wild type when reconstituted with the Schiff base of an n-alkylamine and 11-cis-retinal. In addition, the pigment formed from K296G and the n-propylamine Schiff base of 11-cis-retinal was found to activate transducin in a light-dependent manner, with 30 to 40% of the specific activity measured for the wild-type protein. It appears that the covalent bond is not essential for binding of the chromophore or for catalytic activation of transducin.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Zhukovsky, E A -- Robinson, P R -- Oprian, D D -- 5T32 GM07596-11/GM/NIGMS NIH HHS/ -- EY07965/EY/NEI NIH HHS/ -- R01 EY007965/EY/NEI NIH HHS/ -- S07 RR07044/RR/NCRR NIH HHS/ -- New York, N.Y. -- Science. 1991 Feb 1;251(4993):558-60.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Graduate Department of Biochemistry, Brandeis University, Waltham, MA 02254.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/1990431" target="_blank"〉PubMed〈/a〉
    Schlagwort(e): Binding Sites ; Guanosine 5'-O-(3-Thiotriphosphate)/metabolism ; Kinetics ; Mutagenesis, Site-Directed ; Protein Binding ; Retinaldehyde/*metabolism ; Rhodopsin/genetics/*metabolism/radiation effects ; Schiff Bases ; Spectrophotometry ; Transducin/*metabolism/radiation effects
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    Thema: Biologie , Chemie und Pharmazie , Informatik , Medizin , Allgemeine Naturwissenschaft , Physik
    Standort Signatur Erwartet Verfügbarkeit
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  • 58
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    American Association for the Advancement of Science (AAAS)
    Publikationsdatum: 1991-06-07
    Beschreibung: 〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Marshall, E -- New York, N.Y. -- Science. 1991 Jun 7;252(5011):1372.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/2047849" target="_blank"〉PubMed〈/a〉
    Schlagwort(e): Cancer Care Facilities/*organization & administration ; History, 20th Century ; Humans ; Male
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    Thema: Biologie , Chemie und Pharmazie , Informatik , Medizin , Allgemeine Naturwissenschaft , Physik
    Standort Signatur Erwartet Verfügbarkeit
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  • 59
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    American Association for the Advancement of Science (AAAS)
    Publikationsdatum: 1991-09-13
    Beschreibung: The phosphorylation of the cardiac sodium channel by adenosine 3',5'-monophosphate (cAMP)-dependent protein kinase A leads to its inactivation. It was shown that extracellular cAMP can also modulate the sodium channel of rat, guinea pig, and frog ventricular myocytes in a rapid (less than 50 milliseconds), reversible, and dose-dependent manner. The decrease in the sodium current was accompanied by a 10- to 15-millivolt shift in the steady-state availability of the sodium channel toward more negative potentials and was inhibited by guanosine-5'-O-(2-thiodiphosphate) or pertussis toxin, suggesting that the extracellular modulation of the sodium channel by cAMP is mediated by a membrane-delimited mechanism that includes a pertussis toxin-sensitive G protein.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Sorbera, L A -- Morad, M -- HL16152/HL/NHLBI NIH HHS/ -- New York, N.Y. -- Science. 1991 Sep 13;253(5025):1286-9.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Physiology, University of Pennsylvania, Philadelphia 19104.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/1653970" target="_blank"〉PubMed〈/a〉
    Schlagwort(e): Animals ; Cyclic AMP/*pharmacology ; Guanosine 5'-O-(3-Thiotriphosphate)/pharmacology ; Guanosine Diphosphate/analogs & derivatives/pharmacology ; Guinea Pigs ; Heart/drug effects/*physiology ; Isoproterenol/pharmacology ; Kinetics ; Membrane Potentials/drug effects ; Pertussis Toxin ; Rana pipiens ; Rats ; Receptors, Cyclic AMP/drug effects/*physiology ; Sodium Channels/drug effects/*physiology ; Thionucleotides/pharmacology ; Virulence Factors, Bordetella/pharmacology
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    Thema: Biologie , Chemie und Pharmazie , Informatik , Medizin , Allgemeine Naturwissenschaft , Physik
    Standort Signatur Erwartet Verfügbarkeit
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  • 60
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    American Association for the Advancement of Science (AAAS)
    Publikationsdatum: 1991-10-25
    Beschreibung: The action of dopamine and other monoamine neurotransmitters at synapses is terminated predominantly by high-affinity reuptake into presynaptic terminals by specific sodium-dependent neurotransmitter transport proteins. A complementary DNA encoding a rat dopamine transporter has been isolated that exhibits high sequence similarity with the previously cloned norepinephrine and gamma-aminobutyric acid transporters. Transient expression of the complementary DNA in HeLa cells confirms the cocaine sensitivity of this transporter.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Kilty, J E -- Lorang, D -- Amara, S G -- New York, N.Y. -- Science. 1991 Oct 25;254(5031):578-9.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Yale University, New Haven, CT 06510.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/1948035" target="_blank"〉PubMed〈/a〉
    Schlagwort(e): Amino Acid Sequence ; Animals ; Base Sequence ; Carrier Proteins/drug effects/*genetics/metabolism ; Cloning, Molecular ; Cocaine/*pharmacology ; Dopamine/*metabolism ; Dopamine Plasma Membrane Transport Proteins ; Gene Expression ; HeLa Cells ; Humans ; Kinetics ; *Membrane Glycoproteins ; *Membrane Transport Proteins ; Molecular Sequence Data ; *Nerve Tissue Proteins ; Oligodeoxyribonucleotides ; Polymerase Chain Reaction/methods ; Rats ; Sequence Homology, Nucleic Acid ; Transfection
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    Thema: Biologie , Chemie und Pharmazie , Informatik , Medizin , Allgemeine Naturwissenschaft , Physik
    Standort Signatur Erwartet Verfügbarkeit
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  • 61
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    American Association for the Advancement of Science (AAAS)
    Publikationsdatum: 1991-01-25
    Beschreibung: The higher order folding process of the catalytic RNA derived from the self-splicing intron of Tetrahymena thermophila was monitored with the use of Fe(II)-EDTA-induced free radical chemistry. The overall tertiary structure of the RNA molecule forms cooperatively with the uptake of at least three magnesium ions. Local folding transitions display different metal ion dependencies, suggesting that the RNA tertiary structure assembles through a specific folding intermediate before the catalytic core is formed. Enzymatic activity, assayed with an RNA substrate that is complementary to the catalytic RNA active site, coincides with the cooperative structural transition. The higher order RNA foldings produced by Mg(II), Ca(II), and Sr(II) are similar; however, only the Mg(II)-stabilized RNA is catalytically active. Thus, these results directly demonstrate that divalent metal ions participate in general folding of the ribozyme tertiary structure, and further indicate a more specific involvement of Mg(II) in catalysis.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Celander, D W -- Cech, T R -- New York, N.Y. -- Science. 1991 Jan 25;251(4992):401-7.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Howard Hughes Medical Institute, Department of Chemistry and Biochemistry, University of Colorado, Boulder 80309-0215.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/1989074" target="_blank"〉PubMed〈/a〉
    Schlagwort(e): Animals ; Base Sequence ; Calcium/metabolism ; Densitometry ; Kinetics ; Magnesium/metabolism ; Magnesium Chloride/pharmacology ; Molecular Sequence Data ; Nucleic Acid Conformation ; RNA, Catalytic/*chemistry/drug effects/metabolism ; Strontium/metabolism ; Tetrahymena
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    Thema: Biologie , Chemie und Pharmazie , Informatik , Medizin , Allgemeine Naturwissenschaft , Physik
    Standort Signatur Erwartet Verfügbarkeit
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  • 62
    Publikationsdatum: 1991-03-29
    Beschreibung: Cloned integrin alpha 2 subunit complementary DNA was expressed on human rhabdomyosarcoma (RD) cells to give a functional VLA-2 (alpha 2 beta 1) adhesion receptor. The VLA-2-positive RDA2 cells not only showed increased adhesion to collagen and laminin in vitro, but also formed substantially more metastatic tumor colonies in nude mice after either intravenous or subcutaneous injection. These results show that a specific adhesion receptor (VLA-2) can markedly enhance both experimental and spontaneous metastasis. In contrast to the metastasis results, there was no difference in either the in vitro growth rate or apparent in vivo tumorigenicity of RD and RDA2 cells.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Chan, B M -- Matsuura, N -- Takada, Y -- Zetter, B R -- Hemler, M E -- CA 37393/CA/NCI NIH HHS/ -- GM 38903/GM/NIGMS NIH HHS/ -- New York, N.Y. -- Science. 1991 Mar 29;251(5001):1600-2.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Dana-Farber Cancer Institute, Harvard Medical School, Boston, MA 02115.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/2011740" target="_blank"〉PubMed〈/a〉
    Schlagwort(e): Animals ; *Cell Adhesion ; Cell Line ; Collagen ; Fibronectins ; Humans ; Kinetics ; Laminin ; Lung Neoplasms/pathology/secondary ; Mice ; Mice, Nude ; Neoplasm Metastasis ; Neoplasm Transplantation ; Receptors, Very Late Antigen/genetics/*physiology ; Rhabdomyosarcoma/*pathology ; Transplantation, Heterologous
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    Thema: Biologie , Chemie und Pharmazie , Informatik , Medizin , Allgemeine Naturwissenschaft , Physik
    Standort Signatur Erwartet Verfügbarkeit
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  • 63
    Publikationsdatum: 1991-06-07
    Beschreibung: National, longitudinal surveys from Great Britain and the United States were used to investigate the effects of divorce on children. In both studies, a subsample of children who were in two-parent families during the initial interview (at age 7 in the British data and at ages 7 to 11 in the U.S. data) were followed through the next interview (at age 11 and ages 11 to 16, respectively). At both time points in the British data, parents and teachers independently rated the children's behavior problems, and the children were given reading and mathematics achievement tests. At both time points in the U.S. data, parents rated the children's behavior problems. Children whose parents divorced or separated between the two time points were compared to children whose families remained intact. For boys, the apparent effect of separation or divorce on behavior problems and achievement at the later time point was sharply reduced by considering behavior problems, achievement levels, and family difficulties that were present at the earlier time point, before any of the families had broken up. For girls, the reduction in the apparent effect of divorce occurred to a lesser but still noticeable extent once preexisting conditions were considered.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Cherlin, A J -- Furstenberg, F F Jr -- Chase-Lansdale, L -- Kiernan, K E -- Robins, P K -- Morrison, D R -- Teitler, J O -- HD25936/HD/NICHD NIH HHS/ -- New York, N.Y. -- Science. 1991 Jun 7;252(5011):1386-9.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Sociology, Johns Hopkins University, Baltimore, MD 21218.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/2047851" target="_blank"〉PubMed〈/a〉
    Schlagwort(e): Achievement ; Adolescent ; Child ; Child Behavior ; Divorce/*psychology ; England ; Female ; Humans ; Longitudinal Studies ; Male ; United States
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    Thema: Biologie , Chemie und Pharmazie , Informatik , Medizin , Allgemeine Naturwissenschaft , Physik
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  • 64
    Publikationsdatum: 1991-08-02
    Beschreibung: Modulation of the activity of potassium and other ion channels is an essential feature of nervous system function. The open probability of a large conductance Ca(2+)-activated K+ channel from rat brain, incorporated into planar lipid bilayers, is increased by the addition of adenosine triphosphate (ATP) to the cytoplasmic side of the channel. This modulation takes place without the addition of protein kinase, requires Mg2+, and is mimicked by an ATP analog that serves as a substrate for protein kinases but not by a nonhydrolyzable ATP analog. Addition of protein phosphatase 1 reverses the modulation by MgATP. Thus, there may be an endogenous protein kinase activity firmly associated with this K+ channel. Some ion channels may exist in a complex that contains regulatory protein kinases and phosphatases.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Chung, S K -- Reinhart, P H -- Martin, B L -- Brautigan, D -- Levitan, I B -- DK31374/DK/NIDDK NIH HHS/ -- NS17910/NS/NINDS NIH HHS/ -- New York, N.Y. -- Science. 1991 Aug 2;253(5019):560-2.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Graduate Department of Biochemistry, Brandeis University, Waltham, MA 02254.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/1857986" target="_blank"〉PubMed〈/a〉
    Schlagwort(e): Adenosine Triphosphate/pharmacology ; Animals ; Brain/*physiology ; Calcium/*pharmacology ; Kinetics ; Lipid Bilayers ; Potassium Channels/drug effects/metabolism/*physiology ; Protein Kinases/*metabolism ; Rats
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  • 65
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    Unbekannt
    American Association for the Advancement of Science (AAAS)
    Publikationsdatum: 1991-09-06
    Beschreibung: 〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Fox, C H -- New York, N.Y. -- Science. 1991 Sep 6;253(5024):1075.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/1887232" target="_blank"〉PubMed〈/a〉
    Schlagwort(e): *Ethics, Professional ; Female ; Humans ; Laboratories/organization & administration ; Male ; Research Support as Topic ; Scientific Misconduct ; United States
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    Thema: Biologie , Chemie und Pharmazie , Informatik , Medizin , Allgemeine Naturwissenschaft , Physik
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  • 66
    Publikationsdatum: 1991-02-22
    Beschreibung: Macrophage-like U-937 cells secrete a 22-kilodalton heparin-binding growth factor that is mitogenic for BALB-3T3 fibroblasts and smooth muscle cells, but not endothelial cells. The amino acid sequence predicted from complementary DNA clones indicates that the mitogen is a new member of the epidermal growth factor (EGF) family. This heparin-binding EGF-like growth factor (HB-EGF) binds to EGF receptors on A-431 epidermoid carcinoma cells and smooth muscle cells, but is a far more potent mitogen for smooth muscle cells than is EGF. HB-EGF is also expressed in cultured human macrophages and may be involved in macrophage-mediated cellular proliferation.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Higashiyama, S -- Abraham, J A -- Miller, J -- Fiddes, J C -- Klagsbrun, M -- CA37392/CA/NCI NIH HHS/ -- CA45548/CA/NCI NIH HHS/ -- New York, N.Y. -- Science. 1991 Feb 22;251(4996):936-9.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Surgical Research, Children's Hospital, Boston, MA 02115.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/1840698" target="_blank"〉PubMed〈/a〉
    Schlagwort(e): Amino Acid Sequence ; Cell Division/drug effects ; Cell Line ; Chromatography, Affinity ; Chromatography, High Pressure Liquid ; DNA Replication/drug effects ; Epidermal Growth Factor/genetics/isolation & ; purification/*metabolism/pharmacology ; Growth Substances/*metabolism ; Heparin/*metabolism ; Humans ; Kinetics ; Macrophages/*metabolism ; Molecular Sequence Data ; Protein Binding ; Receptor, Epidermal Growth Factor/metabolism ; Sequence Homology, Nucleic Acid
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    Thema: Biologie , Chemie und Pharmazie , Informatik , Medizin , Allgemeine Naturwissenschaft , Physik
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  • 67
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    Unbekannt
    American Association for the Advancement of Science (AAAS)
    Publikationsdatum: 1991-05-03
    Beschreibung: Fatal neonatal sibling aggression is common in predatory birds but has not been previously reported in wild mammals. Spotted hyena females are strongly masculinized, both anatomically and behaviorally, apparently by high levels of androgens during ontogeny. Neonates display elevated androgen levels, precocial motor development, and fully erupted front teeth. Litters are usually twins, and siblings fight violently at birth, apparently leading to the death of one sibling in same-sex litters, whereas in mixed-sex litters both siblings usually survive.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Frank, L G -- Glickman, S E -- Licht, P -- MH39917/MH/NIMH NIH HHS/ -- New York, N.Y. -- Science. 1991 May 3;252(5006):702-4.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Psychology, University of California, Berkeley 94720.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/2024122" target="_blank"〉PubMed〈/a〉
    Schlagwort(e): Aggression/*physiology ; Androgens/*blood ; Animals ; Animals, Newborn/*physiology ; Behavior, Animal/*physiology ; Carnivora/*physiology ; Dentition ; Female ; Male ; Motor Activity/physiology ; *Sex Characteristics ; Sex Ratio ; Sibling Relations ; Tooth Eruption/physiology
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    Thema: Biologie , Chemie und Pharmazie , Informatik , Medizin , Allgemeine Naturwissenschaft , Physik
    Standort Signatur Erwartet Verfügbarkeit
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  • 68
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    American Association for the Advancement of Science (AAAS)
    Publikationsdatum: 1991-03-15
    Beschreibung: The representation of pain in the cerebral cortex is less well understood than that of any other sensory system. However, with the use of magnetic resonance imaging and positron emission tomography in humans, it has now been demonstrated that painful heat causes significant activation of the contralateral anterior cingulate, secondary somatosensory, and primary somatosensory cortices. This contrasts with the predominant activation of primary somatosensory cortex caused by vibrotactile stimuli in similar experiments. Furthermore, the unilateral cingulate activation indicates that this forebrain area, thought to regulate emotions, contains an unexpectedly specific representation of pain.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Talbot, J D -- Marrett, S -- Evans, A C -- Meyer, E -- Bushnell, M C -- Duncan, G H -- New York, N.Y. -- Science. 1991 Mar 15;251(4999):1355-8.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Laboratoire de neurophysiologie comportementale, Faculte de medecine dentaire, Universite de Montreal, Quebec, Canada.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/2003220" target="_blank"〉PubMed〈/a〉
    Schlagwort(e): Adult ; Animals ; Anxiety/physiopathology ; Brain Mapping ; Cerebral Cortex/*physiology ; Functional Laterality ; Hot Temperature ; Humans ; Magnetic Resonance Imaging ; Male ; Pain/*physiopathology ; Tomography, Emission-Computed
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    Thema: Biologie , Chemie und Pharmazie , Informatik , Medizin , Allgemeine Naturwissenschaft , Physik
    Standort Signatur Erwartet Verfügbarkeit
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  • 69
    Publikationsdatum: 1991-05-31
    Beschreibung: An identified neuron of the leech, a Retzius cell, has been attached to the open gate of a p-channel field-effect transistor. Action potentials, spontaneous or stimulated, modulate directly the source-drain current in silicon. The electronic signals match the shape of the action potential. The average voltage on the gate was up to 25 percent of the intracellular voltage change. Occasionally weak signals that resemble the first derivative of the action potential were observed. The junctions can be described by a model that includes capacitive coupling of the plasma membrane and the gate oxide and that accounts for variable resistance of the seal.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Fromherz, P -- Offenhausser, A -- Vetter, T -- Weis, J -- New York, N.Y. -- Science. 1991 May 31;252(5010):1290-3.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Abteilung Biophysik der Universitat Ulm, Germany.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/1925540" target="_blank"〉PubMed〈/a〉
    Schlagwort(e): Action Potentials ; Animals ; Electric Conductivity ; Electrophysiology ; Kinetics ; Leeches/*physiology ; Microscopy, Electron, Scanning ; Neurons/*physiology/ultrastructure ; *Silicon ; Transistors, Electronic
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    Standort Signatur Erwartet Verfügbarkeit
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  • 70
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    American Association for the Advancement of Science (AAAS)
    Publikationsdatum: 1991-10-11
    Beschreibung: It is generally accepted that glutamate serves as the neurotransmitter at most excitatory synapses in the mammalian central nervous system (CNS). Synaptic release of glutamate may trigger a fast and a slow excitatory postsynaptic current (EPSC). The slow EPSC is mediated by N-methyl-D-aspartate (NMDA) receptor channels, whereas the fast EPSC is mediated by non-NMDA receptor channels. The nootropic agent aniracetam selectively and reversibly slows the desensitization kinetics of non-NMDA channels and lengthens their single-channel open times. Antiracetam also modulates the kinetics of the fast EPSC in a manner that mirrors its action on the kinetics of the non-NMDA channels. These results support the hypothesis that the properties of the non-NMDA glutamate channels rather than the rate of neurotransmitter clearance are the primary determinants of the kinetics of the fast EPSC in the mammalian CNS.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Tang, C M -- Shi, Q Y -- Katchman, A -- Lynch, G -- NS28158/NS/NINDS NIH HHS/ -- New York, N.Y. -- Science. 1991 Oct 11;254(5029):288-90.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Neurology, University of Pennsylvania, Philadelphia.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/1681589" target="_blank"〉PubMed〈/a〉
    Schlagwort(e): Action Potentials/*drug effects ; Animals ; Glutamates/*physiology ; Glutamic Acid ; Kinetics ; Pyrrolidinones/*pharmacology ; Rats ; Receptors, Glutamate ; Receptors, N-Methyl-D-Aspartate/drug effects ; Receptors, Neurotransmitter/drug effects ; Synapses/*drug effects
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    Thema: Biologie , Chemie und Pharmazie , Informatik , Medizin , Allgemeine Naturwissenschaft , Physik
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  • 71
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    American Association for the Advancement of Science (AAAS)
    Publikationsdatum: 1991-11-01
    Beschreibung: 〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉New York, N.Y. -- Science. 1991 Nov 1;254(5032):630.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/1948038" target="_blank"〉PubMed〈/a〉
    Schlagwort(e): Brain/*physiology ; Female ; *Homosexuality ; Humans ; Male ; Sexual Behavior/*physiology
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    Thema: Biologie , Chemie und Pharmazie , Informatik , Medizin , Allgemeine Naturwissenschaft , Physik
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  • 72
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    American Association for the Advancement of Science (AAAS)
    Publikationsdatum: 1991-10-25
    Beschreibung: SP-B is a protein in pulmonary surfactant that is, in greatest part, responsible for resistance to surface tension and prevention of collapse of pulmonary alveoli. Peptides of 21 residues, synthesized following the sequence of SP-B or resembling the hydrophobic and hydrophilic domains of SP-B (such as RLLLLRLLLLRLLLLRLLLLR, R, Arg, and L, Leu), enhanced the abilities of phospholipids to reduce surface tension both in vitro and in vivo. Intermittent positively charged residues were essential for this activity. The SP-B-like peptides were found by tryptophan fluorescence to partition within the phospholipid layer in contact with both polar head groups and acyl side chains. These data, together with findings that the SP-B-related peptides increase inter- and intramolecular order of the phospholipid layer, suggest that SP-B resists surface tension by increasing lateral stability of the phospholipid layer.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Cochrane, C G -- Revak, S D -- GM-37696/GM/NIGMS NIH HHS/ -- HL-23584/HL/NHLBI NIH HHS/ -- New York, N.Y. -- Science. 1991 Oct 25;254(5031):566-8.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Immunology, Scripps Research Institute, La Jolla, CA 92037.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/1948032" target="_blank"〉PubMed〈/a〉
    Schlagwort(e): Amino Acid Sequence ; Kinetics ; Molecular Sequence Data ; Peptides/*chemical synthesis/chemistry ; Phospholipids/metabolism ; Proteolipids/chemistry/*metabolism ; Pulmonary Surfactants/chemistry/*metabolism ; Structure-Activity Relationship ; Surface Tension
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    Thema: Biologie , Chemie und Pharmazie , Informatik , Medizin , Allgemeine Naturwissenschaft , Physik
    Standort Signatur Erwartet Verfügbarkeit
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  • 73
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    American Association for the Advancement of Science (AAAS)
    Publikationsdatum: 1991-09-27
    Beschreibung: 〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Moffat, A S -- New York, N.Y. -- Science. 1991 Sep 27;253(5027):1483.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/1896855" target="_blank"〉PubMed〈/a〉
    Schlagwort(e): Acquired Immunodeficiency Syndrome/prevention & control ; Adolescent ; Adult ; Female ; *Health Surveys ; Humans ; Male ; National Institutes of Health (U.S.) ; *Sexual Behavior ; Sexually Transmitted Diseases/prevention & control ; United States
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    Thema: Biologie , Chemie und Pharmazie , Informatik , Medizin , Allgemeine Naturwissenschaft , Physik
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  • 74
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    American Association for the Advancement of Science (AAAS)
    Publikationsdatum: 1991-09-06
    Beschreibung: Calcium-induced calcium release (CICR) may function widely in calcium-mediated cell signaling, but has been most thoroughly characterized in muscle cells. In a homogenate of sea urchin eggs, which display transients in the intracellular free calcium concentration ([Ca2+]i) during fertilization and anaphase, addition of Ca2+ triggered CICR. Ca2+ release was also induced by the CICR modulators ryanodine and caffeine. Responses to both Ca2+ and CICR modulators (but not Ca2+ release mediated by inositol 1,4,5-trisphosphate) were inhibited by procaine and ruthenium red, inhibitors of CICR. Intact eggs also displayed transients of [Ca2+]i when microinjected with ryanodine. Cyclic ADP-ribose, a metabolite with potent Ca(2+)-releasing properties, appears to act by way of the CICR mechanism and may thus be an endogenous modulator of CICR. A CICR mechanism is present in these nonmuscle cells as is assumed in various models of intracellular Ca2+ wave propagation.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Galione, A -- Lee, H C -- Busa, W B -- HD17484/HD/NICHD NIH HHS/ -- HD22879/HD/NICHD NIH HHS/ -- New York, N.Y. -- Science. 1991 Sep 6;253(5024):1143-6.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Biology, Johns Hopkins University, Baltimore, MD 21218.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/1909457" target="_blank"〉PubMed〈/a〉
    Schlagwort(e): Adenosine Diphosphate Ribose/*pharmacology ; Adenosine Triphosphate/metabolism ; Animals ; Calcium/*metabolism/pharmacology ; Cyclic ADP-Ribose ; Egtazic Acid/pharmacology ; Kinetics ; Ovum/drug effects/*physiology ; Sea Urchins ; Spectrometry, Fluorescence ; Time Factors
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    Thema: Biologie , Chemie und Pharmazie , Informatik , Medizin , Allgemeine Naturwissenschaft , Physik
    Standort Signatur Erwartet Verfügbarkeit
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  • 75
    Publikationsdatum: 1991-12-20
    Beschreibung: The goal of islet transplantation in human diabetes is to maintain the islet grafts in the recipients without the use of immunosuppression. One approach is to encapsulate the donor islets in permselective membranes. Hollow fibers fabricated from an acrylic copolymer were used to encapsulate small numbers of rat islets that were immobilized in an alginate hydrogel for transplantation in diabetic mice. The fibers were biocompatible, prevented rejection, and maintained normoglycemia when transplanted intraperitoneally; hyperglycemia returned when the fibers were removed at 60 days. Normoglycemia was also maintained by subcutaneous implants that had an appropriately constructed outer surface on the fibers.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Lacy, P E -- Hegre, O D -- Gerasimidi-Vazeou, A -- Gentile, F T -- Dionne, K E -- DK01226/DK/NIDDK NIH HHS/ -- New York, N.Y. -- Science. 1991 Dec 20;254(5039):1782-4.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Pathology, Washington University School of Medicine, St. Louis, MO 63110.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/1763328" target="_blank"〉PubMed〈/a〉
    Schlagwort(e): *Acrylic Resins ; Animals ; Animals, Newborn ; Blood Glucose/*metabolism ; Diabetes Mellitus, Experimental/blood/*surgery ; In Vitro Techniques ; Insulin/secretion ; Islets of Langerhans/*secretion ; Islets of Langerhans Transplantation/*physiology ; Male ; Membranes, Artificial ; Mice ; Mice, Inbred C57BL ; *Polyvinyl Chloride ; Rats ; Rats, Inbred WF ; Time Factors ; Transplantation, Heterologous
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    Thema: Biologie , Chemie und Pharmazie , Informatik , Medizin , Allgemeine Naturwissenschaft , Physik
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  • 76
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    American Association for the Advancement of Science (AAAS)
    Publikationsdatum: 1991-05-24
    Beschreibung: The signal recognition particle (SRP) directs signal sequence specific targeting of ribosomes to the rough endoplasmic reticulum. Displacement of the SRP from the signal sequence of a nascent polypeptide is a guanosine triphosphate (GTP)-dependent reaction mediated by the membrane-bound SRP receptor. A nonhydrolyzable GTP analog can replace GTP in the signal sequence displacement reaction, but the SRP then fails to dissociate from the membrane. Complexes of the SRP with its receptor containing the nonhydrolyzable analog are incompetent for subsequent rounds of protein translocation. Thus, vectorial targeting of ribosomes to the endoplasmic reticulum is controlled by a GTP hydrolysis cycle that regulates the affinity between the SRP, signal sequences, and the SRP receptor.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Connolly, T -- Rapiejko, P J -- Gilmore, R -- GM 35687/GM/NIGMS NIH HHS/ -- New York, N.Y. -- Science. 1991 May 24;252(5009):1171-3.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Biochemistry and Molecular Biology, University of Massachusetts Medical School, Worcester 01655.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/1851576" target="_blank"〉PubMed〈/a〉
    Schlagwort(e): Animals ; Centrifugation, Density Gradient ; Endoplasmic Reticulum/metabolism ; GTP-Binding Proteins/genetics/metabolism ; Guanosine Triphosphate/*metabolism ; Guanylyl Imidodiphosphate/pharmacology ; Hydrolysis ; Kinetics ; Macromolecular Substances ; Protein Binding ; Protein Biosynthesis ; Receptors, Cell Surface/isolation & purification/*metabolism ; *Receptors, Cytoplasmic and Nuclear ; *Receptors, Peptide ; Ribonucleoproteins/genetics/isolation & purification/*metabolism ; Ribosomes/metabolism ; Signal Recognition Particle ; Transcription, Genetic ; Vesicular stomatitis Indiana virus/genetics/metabolism
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    Thema: Biologie , Chemie und Pharmazie , Informatik , Medizin , Allgemeine Naturwissenschaft , Physik
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  • 77
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    American Association for the Advancement of Science (AAAS)
    Publikationsdatum: 1991-11-29
    Beschreibung: The N-end rule relates the in vivo half-life of a protein to the identity of its amino-terminal residue. Distinct versions of the N-end rule operate in all eukaryotes examined. It is shown that the bacterium Escherichia coli also has the N-end rule pathway. Amino-terminal arginine, lysine, leucine, phenylalanine, tyrosine, and tryptophan confer 2-minute half-lives on a test protein; the other amino-terminal residues confer greater than 10-hour half-lives on the same protein. Amino-terminal arginine and lysine are secondary destabilizing residues in E. coli because their activity depends on their conjugation to the primary destabilizing residues leucine or phenylalanine by leucine, phenylalanine-transfer RNA-protein transferase. The adenosine triphosphate-dependent protease Clp (Ti) is required for the degradation of N-end rule substrates in E. coli.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Tobias, J W -- Shrader, T E -- Rocap, G -- Varshavsky, A -- DK39520/DK/NIDDK NIH HHS/ -- GM31530/GM/NIGMS NIH HHS/ -- New York, N.Y. -- Science. 1991 Nov 29;254(5036):1374-7.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Biology, Massachusetts Institute of Technology, Cambridge 02139.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/1962196" target="_blank"〉PubMed〈/a〉
    Schlagwort(e): Amino Acid Sequence ; Animals ; Bacteria/*metabolism ; Bacterial Proteins/*metabolism ; Escherichia coli/enzymology/metabolism ; Half-Life ; Kinetics ; Molecular Sequence Data ; Rabbits ; Reticulocytes/metabolism ; Saccharomyces cerevisiae/enzymology/metabolism ; Structure-Activity Relationship ; beta-Galactosidase/*metabolism
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    Thema: Biologie , Chemie und Pharmazie , Informatik , Medizin , Allgemeine Naturwissenschaft , Physik
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  • 78
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    American Association for the Advancement of Science (AAAS)
    Publikationsdatum: 1991-08-23
    Beschreibung: The N-methyl-D-aspartate (NMDA) receptor, a subtype of glutamate receptors, plays a key role in synaptic plasticity in the nervous system. After NMDA receptor activation, calcium entry into the postsynaptic neuron is a critical initial event. However, the subsequent mechanisms by which the NMDA receptor signal is processed are incompletely understood. Stimulation of cultured rat hippocampal cells with glutamate resulted in the rapid and transient tyrosine phosphorylation of a 39-kilodalton protein (p39). Tyrosine phosphorylation of p39 was triggered by the NMDA receptor and required an influx of Ca2+ from the extracellular medium. Because p39 was found to be highly related or identical to the microtubule-associated protein 2 kinase, the NMDA receptor signal may be processed by a sequential activation of protein kinases.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Bading, H -- Greenberg, M E -- CA 43855/CA/NCI NIH HHS/ -- NS 28829/NS/NINDS NIH HHS/ -- New York, N.Y. -- Science. 1991 Aug 23;253(5022):912-4.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Microbiology and Molecular Genetics, Harvard Medical School, Boston, MA 02115.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/1715095" target="_blank"〉PubMed〈/a〉
    Schlagwort(e): 2-Amino-5-phosphonovalerate/pharmacology ; Animals ; Calcium/metabolism ; Calcium-Calmodulin-Dependent Protein Kinases ; Cells, Cultured ; Glutamates/pharmacology ; Glutamic Acid ; Hippocampus/drug effects/metabolism ; Immunoblotting ; Kinetics ; Phosphoproteins/*metabolism ; Phosphorylation ; Phosphotyrosine ; Protein Kinases/metabolism ; Rats ; Receptors, N-Methyl-D-Aspartate/*metabolism ; Tyrosine/*analogs & derivatives/metabolism
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    Thema: Biologie , Chemie und Pharmazie , Informatik , Medizin , Allgemeine Naturwissenschaft , Physik
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  • 79
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    American Association for the Advancement of Science (AAAS)
    Publikationsdatum: 1991-05-24
    Beschreibung: 〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Hoffman, M -- New York, N.Y. -- Science. 1991 May 24;252(5009):1070.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/2031180" target="_blank"〉PubMed〈/a〉
    Schlagwort(e): Adult ; Chromosome Mapping ; Female ; Fragile X Syndrome/*genetics ; Humans ; Male ; *Mutation ; X Chromosome
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    Thema: Biologie , Chemie und Pharmazie , Informatik , Medizin , Allgemeine Naturwissenschaft , Physik
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  • 80
    Publikationsdatum: 1991-05-03
    Beschreibung: The imaging of living specimens in water by x-ray microscopy can be greatly enhanced with the use of an intense flash x-ray source and sophisticated technologies for reading x-ray images. A subnanosecond [corrected] x-ray pulse from a laser-produced plasma was used to record the x-ray image of living sea urchin sperm in an x-ray resist. The resist relief was visualized at high resolution by atomic-force microscopy. Internal structure of the sperm head was evident, and the carbon density in a flagellum was estimated from the relief height.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Tomie, T -- Shimizu, H -- Majima, T -- Yamada, M -- Kanayama, T -- Kondo, H -- Yano, M -- Ono, M -- New York, N.Y. -- Science. 1991 May 3;252(5006):691-3.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Electrotechnical Laboratory, Ibaraki, Japan.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/2024121" target="_blank"〉PubMed〈/a〉
    Schlagwort(e): Animals ; Cell Nucleus/ultrastructure ; Male ; Methylmethacrylates ; Microscopy/*methods ; Mitochondria/ultrastructure ; *Sea Urchins ; Seawater ; Sperm Tail/*ultrastructure ; X-Rays
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    Thema: Biologie , Chemie und Pharmazie , Informatik , Medizin , Allgemeine Naturwissenschaft , Physik
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  • 81
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    American Association for the Advancement of Science (AAAS)
    Publikationsdatum: 1991-01-04
    Beschreibung: The N-methyl-D-aspartate (NMDA) subtype of the glutamate receptor is an important mediator of several forms of neural and behavioral plasticity. The present studies examined whether NMDA receptors might be involved in the development of opiate tolerance and dependence, two examples of behavioral plasticity. The noncompetitive NMDA receptor antagonist MK-801 attenuated the development of tolerance to the analgesic effect of morphine without affecting acute morphine analgesia. In addition, MK-801 attenuated the development of morphine dependence as assessed by naloxone-precipitated withdrawal. These results suggest that NMDA receptors may be important in the development of opiate tolerance and dependence.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Trujillo, K A -- Akil, H -- DA02265/DA/NIDA NIH HHS/ -- DA05336/DA/NIDA NIH HHS/ -- MH422251/MH/NIMH NIH HHS/ -- New York, N.Y. -- Science. 1991 Jan 4;251(4989):85-7.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Mental Health Research Institute, University of Michigan, Ann Arbor 48109-0720.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/1824728" target="_blank"〉PubMed〈/a〉
    Schlagwort(e): *Analgesia ; Animals ; Behavior, Animal/drug effects ; Dizocilpine Maleate/*pharmacology ; Drug Tolerance ; Male ; *Morphine ; Naloxone/pharmacology ; Pain Measurement ; Rats ; Rats, Inbred Strains ; Receptors, N-Methyl-D-Aspartate/antagonists & inhibitors/*physiology ; *Substance-Related Disorders
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    Thema: Biologie , Chemie und Pharmazie , Informatik , Medizin , Allgemeine Naturwissenschaft , Physik
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  • 82
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    American Association for the Advancement of Science (AAAS)
    Publikationsdatum: 1991-08-30
    Beschreibung: 〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Gibbons, A -- New York, N.Y. -- Science. 1991 Aug 30;253(5023):957-9.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/1887226" target="_blank"〉PubMed〈/a〉
    Schlagwort(e): Animals ; Brain/*anatomy & histology/physiology ; Corpus Callosum/anatomy & histology/physiology ; Female ; Humans ; Hypothalamus/*anatomy & histology/physiology ; Male ; Rats ; *Sex Characteristics
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    Thema: Biologie , Chemie und Pharmazie , Informatik , Medizin , Allgemeine Naturwissenschaft , Physik
    Standort Signatur Erwartet Verfügbarkeit
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  • 83
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    American Association for the Advancement of Science (AAAS)
    Publikationsdatum: 1991-08-30
    Beschreibung: The anterior hypothalamus of the brain participates in the regulation of male-typical sexual behavior. The volumes of four cell groups in this region [interstitial nuclei of the anterior hypothalamus (INAH) 1, 2, 3, and 4] were measured in postmortem tissue from three subject groups: women, men who were presumed to be heterosexual, and homosexual men. No differences were found between the groups in the volumes of INAH 1, 2, or 4. As has been reported previously, INAH 3 was more than twice as large in the heterosexual men as in the women. It was also, however, more than twice as large in the heterosexual men as in the homosexual men. This finding indicates that INAH is dimorphic with sexual orientation, at least in men, and suggests that sexual orientation has a biological substrate.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉LeVay, S -- New York, N.Y. -- Science. 1991 Aug 30;253(5023):1034-7.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Salk Institute for Biological Studies, San Diego, CA 92186.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/1887219" target="_blank"〉PubMed〈/a〉
    Schlagwort(e): Anterior Hypothalamic Nucleus/*anatomy & histology/cytology ; Female ; *Homosexuality ; Humans ; Male ; Optic Chiasm/anatomy & histology ; Sexual Behavior/*physiology
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    Thema: Biologie , Chemie und Pharmazie , Informatik , Medizin , Allgemeine Naturwissenschaft , Physik
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  • 84
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    American Association for the Advancement of Science (AAAS)
    Publikationsdatum: 1991-04-19
    Beschreibung: A link is found between T wave alternans and vulnerability to ventricular fibrillation, and a new approach is provided for quantification of susceptibility to malignant arrhythmias. Complex demodulation reveals that alternation of the electrocardiogram is concentrated during the first half of the T wave, coinciding with the vulnerable period of the cardiac cycle. During myocardial ischemia and reperfusion, there are marked increases in the degree of T wave alternans that parallel the established time course of changes in vulnerability. The influence of the sympathetic nervous system in arrhythmogenesis is also accurately detected. Ultimately, complex demodulation of the electrocardiogram could provide a technique for identification and management of individuals at risk for sudden cardiac death.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Nearing, B D -- Huang, A H -- Verrier, R L -- HL-33567/HL/NHLBI NIH HHS/ -- New York, N.Y. -- Science. 1991 Apr 19;252(5004):437-40.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Georgetown University School of Medicine, Washington, DC 20007.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/2017682" target="_blank"〉PubMed〈/a〉
    Schlagwort(e): Animals ; Constriction ; Coronary Vessels ; Dogs ; Electric Stimulation ; *Electrocardiography ; Electrophysiology ; Female ; Heart Conduction System/*physiopathology ; Kinetics ; Male ; Mathematics ; Reperfusion ; Ventricular Fibrillation/*physiopathology
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    Thema: Biologie , Chemie und Pharmazie , Informatik , Medizin , Allgemeine Naturwissenschaft , Physik
    Standort Signatur Erwartet Verfügbarkeit
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  • 85
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    American Association for the Advancement of Science (AAAS)
    Publikationsdatum: 1991-08-30
    Beschreibung: 〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Barinaga, M -- New York, N.Y. -- Science. 1991 Aug 30;253(5023):956-7.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/1887225" target="_blank"〉PubMed〈/a〉
    Schlagwort(e): Female ; *Homosexuality ; Humans ; Hypothalamus/cytology/*physiology ; Male ; Sex Characteristics ; Sexual Behavior/*physiology
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    Thema: Biologie , Chemie und Pharmazie , Informatik , Medizin , Allgemeine Naturwissenschaft , Physik
    Standort Signatur Erwartet Verfügbarkeit
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  • 86
    facet.materialart.
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    American Association for the Advancement of Science (AAAS)
    Publikationsdatum: 1991-03-01
    Beschreibung: 〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Barinaga, M -- New York, N.Y. -- Science. 1991 Mar 1;251(4997):1020-1.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/1998115" target="_blank"〉PubMed〈/a〉
    Schlagwort(e): Animals ; Contraception/*methods ; Egg Proteins/immunology ; Female ; Male ; Spermatozoa/immunology ; Vaccines
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    Thema: Biologie , Chemie und Pharmazie , Informatik , Medizin , Allgemeine Naturwissenschaft , Physik
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  • 87
    Publikationsdatum: 1991-03-08
    Beschreibung: Epidermal growth factor and platelet-derived growth factor can stimulate the production of the second messenger inositol trisphosphate in responsive cells, but the biochemical pathway for these signaling events has been uncertain because the reactions have not been reconstituted with purified molecules in vitro. A reconstitution is described that requires not only the growth factor, its receptor with tyrosine kinase activity, and the soluble phospholipase C-gamma 1, but also the small soluble actin-binding protein profilin. Profilin binds to the substrate phosphatidylinositol 4,5-bisphosphate and inhibits its hydrolysis by unphosphorylated phospholipase C-gamma 1. Phosphorylation of phospholipase C-gamma 1 by the epidermal growth factor receptor tyrosine kinase overcomes the inhibitory effect of profilin and results in an effective activation of phospholipase C-gamma 1.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Goldschmidt-Clermont, P J -- Kim, J W -- Machesky, L M -- Rhee, S G -- Pollard, T D -- GM-26338/GM/NIGMS NIH HHS/ -- New York, N.Y. -- Science. 1991 Mar 8;251(4998):1231-3.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Cell Biology and Anatomy, Johns Hopkins University School of Medicine, Baltimore, MD 21205.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/1848725" target="_blank"〉PubMed〈/a〉
    Schlagwort(e): Animals ; Contractile Proteins/metabolism ; Epidermal Growth Factor/*metabolism ; Inositol Phosphates/metabolism ; Isoenzymes/*metabolism ; Kinetics ; Microfilament Proteins/*metabolism ; Phosphatidylinositol 4,5-Diphosphate ; Phosphatidylinositols/metabolism ; Phosphorylation ; Profilins ; Protein-Tyrosine Kinases/*metabolism ; Receptor, Epidermal Growth Factor/*metabolism ; Signal Transduction ; Type C Phospholipases/*metabolism ; Tyrosine
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    Thema: Biologie , Chemie und Pharmazie , Informatik , Medizin , Allgemeine Naturwissenschaft , Physik
    Standort Signatur Erwartet Verfügbarkeit
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  • 88
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    American Association for the Advancement of Science (AAAS)
    Publikationsdatum: 1991-09-13
    Beschreibung: Interleukin-8 (IL-8) is an inflammatory cytokine that activates neutrophil chemotaxis, degranulation, and the respiratory burst. Neutrophils express receptors for IL-8 that are coupled to guanine nucleotide-binding proteins (G proteins); binding of IL-8 to its receptor induces the mobilization of intracellular calcium stores. A cDNA clone from HL-60 neutrophils, designated p2, has now been isolated that encodes a human IL-8 receptor. When p2 is expressed in oocytes from Xenopus laevis, the oocytes bind 125I-labeled IL-8 specifically and respond to IL-8 by mobilizing calcium stores with an EC50 of 20 nM. This IL-8 receptor has 77% amino acid identity with a second human neutrophil receptor isotype that binds IL-8 with higher affinity. It also exhibits 69% amino acid identity with a protein reported to be an N-formyl peptide receptor from rabbit neutrophils, but less than 30% identity with all other known G protein-coupled receptors, including the human N-formyl peptide receptor.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Murphy, P M -- Tiffany, H L -- New York, N.Y. -- Science. 1991 Sep 13;253(5025):1280-3.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Laboratory of Host Defenses, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/1891716" target="_blank"〉PubMed〈/a〉
    Schlagwort(e): Amino Acid Sequence ; Animals ; Binding, Competitive ; Cloning, Molecular/methods ; DNA/genetics ; Gene Library ; Humans ; Interleukin-8/*metabolism/pharmacology ; Kinetics ; Molecular Sequence Data ; Neutrophils/immunology ; Oocytes/drug effects/physiology ; Protein Biosynthesis ; Rabbits ; Receptors, Immunologic/drug effects/*genetics/physiology ; Receptors, Interleukin-8A ; Recombinant Proteins/metabolism ; Sequence Homology, Nucleic Acid ; Signal Transduction ; Transcription, Genetic ; Xenopus
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    Thema: Biologie , Chemie und Pharmazie , Informatik , Medizin , Allgemeine Naturwissenschaft , Physik
    Standort Signatur Erwartet Verfügbarkeit
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  • 89
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    American Association for the Advancement of Science (AAAS)
    Publikationsdatum: 1992-10-09
    Beschreibung: During early development of the mammalian cerebral cortex, young neurons migrate outward from the site of their final mitosis in the ventricular zone into the cortical plate, where they form the adult cortex. Time-lapse confocal microscopy was used to observe directly the dynamic behaviors of migrating cells in living slices of developing cortex. The majority of cells migrated along a radial pathway, consistent with the view that cortical neurons migrate along radial glial fibers. A fraction of cells, however, turned within the intermediate zone and migrated orthogonal to the radial fibers. This orthogonal migration may contribute to the tangential dispersion of clonally related cortical neurons.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉O'Rourke, N A -- Dailey, M E -- Smith, S J -- McConnell, S K -- EY06314/EY/NEI NIH HHS/ -- NS09027/NS/NINDS NIH HHS/ -- NS28587/NS/NINDS NIH HHS/ -- etc. -- New York, N.Y. -- Science. 1992 Oct 9;258(5080):299-302.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Biological Sciences, Stanford University, CA 94305.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/1411527" target="_blank"〉PubMed〈/a〉
    Schlagwort(e): Animals ; Antibodies, Monoclonal ; Carbocyanines ; Cell Movement ; Cerebral Cortex/cytology/*growth & development ; Culture Techniques ; Ferrets ; Fluorescent Dyes ; Immunohistochemistry ; Kinetics ; Lasers ; Microscopy ; Neurons/*physiology ; Vimentin/immunology
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    Thema: Biologie , Chemie und Pharmazie , Informatik , Medizin , Allgemeine Naturwissenschaft , Physik
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  • 90
    Publikationsdatum: 1992-11-13
    Beschreibung: When glycine418 of Escherichia coli glutathione reductase, which is in a closely packed region of the dimer interface, is replaced with a bulky tryptophan residue, the enzyme becomes highly cooperative (Hill coefficient 1.76) for glutathione binding. The cooperativity is lost when the mutant subunit is hybridized with a wild-type subunit to create a heterodimer. The mutation appears to disrupt atomic packing at the dimer interface, which induces a change of kinetic mechanism. A single mutation in a region of the protein remote from the active site can thus act as a molecular switch to confer cooperativity on an enzyme.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Scrutton, N S -- Deonarain, M P -- Berry, A -- Perham, R N -- New York, N.Y. -- Science. 1992 Nov 13;258(5085):1140-3.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Biochemistry, University of Cambridge, United Kingdom.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/1439821" target="_blank"〉PubMed〈/a〉
    Schlagwort(e): Base Sequence ; Binding Sites ; Escherichia coli/*enzymology/genetics ; Genes, Bacterial ; Glutathione/metabolism ; Glutathione Reductase/*chemistry/genetics/metabolism ; Glycine/chemistry ; Kinetics ; Macromolecular Substances ; Models, Molecular ; Molecular Sequence Data ; Molecular Structure ; *Mutagenesis, Site-Directed ; NADP/metabolism ; Plasmids ; Protein Multimerization ; Tryptophan/chemistry
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    Thema: Biologie , Chemie und Pharmazie , Informatik , Medizin , Allgemeine Naturwissenschaft , Physik
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  • 91
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    American Association for the Advancement of Science (AAAS)
    Publikationsdatum: 1992-08-07
    Beschreibung: 〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Palca, J -- New York, N.Y. -- Science. 1992 Aug 7;257(5071):739.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/1496391" target="_blank"〉PubMed〈/a〉
    Schlagwort(e): Adolescent ; *Crime ; Female ; *Genetics, Medical ; Humans ; Male ; *National Institutes of Health (U.S.) ; *Research Support as Topic ; United States ; United States Dept. of Health and Human Services ; *Violence
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    Thema: Biologie , Chemie und Pharmazie , Informatik , Medizin , Allgemeine Naturwissenschaft , Physik
    Standort Signatur Erwartet Verfügbarkeit
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  • 92
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    Unbekannt
    American Association for the Advancement of Science (AAAS)
    Publikationsdatum: 1992-04-10
    Beschreibung: Diacylglycerols, which are generated during phospholipase-catalyzed hydrolysis of phospholipids, stimulated actin polymerization in the presence of highly purified plasma membranes from the cellular slime mold Dictyostelium discoideum. The increased rate of actin polymerization apparently resulted from de novo formation of actin nucleation sites rather than uncapping of existing filament ends, because the membranes lacked detectable endogenous actin. The increased actin nucleation was mediated by a peripheral membrane component other than protein kinase C, the classical target of diacylglycerol action. These results indicate that diacylglycerols increase actin nucleation at plasma membranes and suggest a mechanism whereby signal transduction pathways may control cytoskeletal assembly.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Shariff, A -- Luna, E J -- GM-33048/GM/NIGMS NIH HHS/ -- R01 GM033048/GM/NIGMS NIH HHS/ -- New York, N.Y. -- Science. 1992 Apr 10;256(5054):245-7.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Cell Biology Group, Worcester Foundation for Experimental Biology, Shresbury, MA 01545.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/1373523" target="_blank"〉PubMed〈/a〉
    Schlagwort(e): Actins/*metabolism ; Alkaloids/pharmacology ; Animals ; Calcium/pharmacology ; Cell Membrane/drug effects/*metabolism ; Dictyostelium/*metabolism ; Diglycerides/*pharmacology ; Kinetics ; Macromolecular Substances ; *Naphthalenes ; Polycyclic Compounds/pharmacology ; Protein Kinase C/antagonists & inhibitors ; Staurosporine ; Tetradecanoylphorbol Acetate/pharmacology ; Time Factors
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    Thema: Biologie , Chemie und Pharmazie , Informatik , Medizin , Allgemeine Naturwissenschaft , Physik
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  • 93
    Publikationsdatum: 1992-10-16
    Beschreibung: The corpse of a Late Neolithic individual found in a glacier in Oetztal is unusual because of the intact nature of all body parts that resulted from the characteristics of its mummification process and its protected geographical position with regard to glacier flow. Anthropological data indicate that the man was 25 to 40 years old, was between 156 and 160 centimeters in stature, had a cranial capacity of between 1500 and 1560 cubic centimeters, and likely died of exhaustion.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Seidler, H -- Bernhard, W -- Teschler-Nicola, M -- Platzer, W -- zur Nedden, D -- Henn, R -- Oberhauser, A -- Sjovold, T -- New York, N.Y. -- Science. 1992 Oct 16;258(5081):455-7.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Institut fur Humanbiologie, Universitat Wien, Austria.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/1411539" target="_blank"〉PubMed〈/a〉
    Schlagwort(e): Animals ; Austria ; Ear/anatomy & histology ; Freezing ; History, Ancient ; Hominidae/*anatomy & histology ; Humans ; Italy ; Male ; *Mummies ; Skull/anatomy & histology
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    Thema: Biologie , Chemie und Pharmazie , Informatik , Medizin , Allgemeine Naturwissenschaft , Physik
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  • 94
    Publikationsdatum: 1992-05-22
    Beschreibung: Human immunodeficiency virus type 1 (HIV-1) transmission from infected patients to health-care workers has been well documented, but transmission from an infected health-care worker to a patient has not been reported. After identification of an acquired immunodeficiency syndrome (AIDS) patient who had no known risk factors for HIV infection but who had undergone an invasive procedure performed by a dentist with AIDS, six other patients of this dentist were found to be HIV-infected. Molecular biologic studies were conducted to complement the epidemiologic investigation. Portions of the HIV proviral envelope gene from each of the seven patients, the dentist, and 35 HIV-infected persons from the local geographic area were amplified by polymerase chain reaction and sequenced. Three separate comparative genetic analyses--genetic distance measurements, phylogenetic tree analysis, and amino acid signature pattern analysis--showed that the viruses from the dentist and five dental patients were closely related. These data, together with the epidemiologic investigation, indicated that these patients became infected with HIV while receiving care from a dentist with AIDS.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Ou, C Y -- Ciesielski, C A -- Myers, G -- Bandea, C I -- Luo, C C -- Korber, B T -- Mullins, J I -- Schochetman, G -- Berkelman, R L -- Economou, A N -- New York, N.Y. -- Science. 1992 May 22;256(5060):1165-71.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Division of HIV/AIDS, Centers for Disease Control, Atlanta, GA 30333.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/1589796" target="_blank"〉PubMed〈/a〉
    Schlagwort(e): Acquired Immunodeficiency Syndrome/blood/microbiology/*transmission ; Amino Acid Sequence ; Base Sequence ; DNA, Viral/blood/genetics/isolation & purification ; *Dentistry ; Female ; Florida ; Genetic Variation ; HIV Infections/microbiology/*transmission ; HIV-1/*genetics/isolation & purification ; Humans ; Male ; Molecular Sequence Data ; Monocytes/physiology ; Oligodeoxyribonucleotides ; *Patients ; Phylogeny ; Sequence Homology, Nucleic Acid ; Viral Envelope Proteins/*genetics
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    Thema: Biologie , Chemie und Pharmazie , Informatik , Medizin , Allgemeine Naturwissenschaft , Physik
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  • 95
    Publikationsdatum: 1992-04-03
    Beschreibung: Colorectal (CR) tumors are usually curable if detected before metastasis. Because genetic alterations are associated with the development of these tumors, mutant genes may be found in the stool of individuals with CR neoplasms. The stools of nine patients whose tumors contained mutations of K-ras were analyzed. In eight of the nine cases, the ras mutations were detectable in DNA purified from the stool. These patients included those with benign and malignant neoplasms from proximal and distal colonic epithelium. Thus, colorectal tumors can be detected by a noninvasive method based on the molecular pathogenesis of the disease.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Sidransky, D -- Tokino, T -- Hamilton, S R -- Kinzler, K W -- Levin, B -- Frost, P -- Vogelstein, B -- CA06973/CA/NCI NIH HHS/ -- CA35494/CA/NCI NIH HHS/ -- New York, N.Y. -- Science. 1992 Apr 3;256(5053):102-5.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Oncology, Johns Hopkins University, Baltimore, MD 21231.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/1566048" target="_blank"〉PubMed〈/a〉
    Schlagwort(e): Adult ; Aged ; Amino Acid Sequence ; Base Sequence ; Blotting, Southern ; Carcinoma/diagnosis/*genetics/pathology ; Colonic Neoplasms/diagnosis/*genetics/pathology ; DNA, Neoplasm/genetics/*isolation & purification ; Feces/chemistry ; Female ; *Genes, ras ; Humans ; Male ; Middle Aged ; Molecular Sequence Data ; *Mutation ; Oligodeoxyribonucleotides ; Polymerase Chain Reaction ; Prognosis ; Rectal Neoplasms/diagnosis/*genetics/pathology
    Print ISSN: 0036-8075
    Digitale ISSN: 1095-9203
    Thema: Biologie , Chemie und Pharmazie , Informatik , Medizin , Allgemeine Naturwissenschaft , Physik
    Standort Signatur Erwartet Verfügbarkeit
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  • 96
    facet.materialart.
    Unbekannt
    American Association for the Advancement of Science (AAAS)
    Publikationsdatum: 1992-04-03
    Beschreibung: 〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Palca, J -- New York, N.Y. -- Science. 1992 Apr 3;256(5053):24.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/1566053" target="_blank"〉PubMed〈/a〉
    Schlagwort(e): Adult ; Child ; Female ; *Health Promotion ; Humans ; Infant ; Infant Mortality ; Male ; Middle Aged ; *Minority Groups ; National Institutes of Health (U.S.) ; *Research Support as Topic ; United States
    Print ISSN: 0036-8075
    Digitale ISSN: 1095-9203
    Thema: Biologie , Chemie und Pharmazie , Informatik , Medizin , Allgemeine Naturwissenschaft , Physik
    Standort Signatur Erwartet Verfügbarkeit
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  • 97
    facet.materialart.
    Unbekannt
    American Association for the Advancement of Science (AAAS)
    Publikationsdatum: 1992-05-01
    Beschreibung: A DNA-nicking activity was detected in the sera of patients with various autoimmune pathologies and was shown to be a property of autoantibodies. The DNA hydrolyzing activity, which was purified by affinity and high-performance liquid chromatography, corresponded in size to immunoglobulin M (IgM) and IgG and had a positive response to antibodies to human IgG. The DNA hydrolyzing autoantibodies were stable to acid shock and yielded a DNA degradation pattern that was different from that of deoxyribonuclease (DNase) I and blood DNase.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Shuster, A M -- Gololobov, G V -- Kvashuk, O A -- Bogomolova, A E -- Smirnov, I V -- Gabibov, A G -- New York, N.Y. -- Science. 1992 May 1;256(5057):665-7.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉V.A. Engelhardt Institute of Molecular Biology, Academy of Sciences of Russia, Moscow.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/1585181" target="_blank"〉PubMed〈/a〉
    Schlagwort(e): Acetates/pharmacology ; Acetic Acid ; Autoantibodies/isolation & purification/*metabolism ; Autoimmune Diseases/*metabolism ; Chromatography, High Pressure Liquid ; DNA/*metabolism ; DNA Polymerase I/metabolism ; Deoxyribonuclease I/metabolism ; Electrophoresis, Agar Gel ; Humans ; Immunoglobulin G/isolation & purification/metabolism ; Immunoglobulin M/isolation & purification/metabolism ; Kinetics ; Lupus Erythematosus, Systemic/immunology ; Plasmids
    Print ISSN: 0036-8075
    Digitale ISSN: 1095-9203
    Thema: Biologie , Chemie und Pharmazie , Informatik , Medizin , Allgemeine Naturwissenschaft , Physik
    Standort Signatur Erwartet Verfügbarkeit
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  • 98
    Publikationsdatum: 1992-05-01
    Beschreibung: A membrane polypeptide involved in K+ transport in a higher plant was cloned by complementation of a yeast mutant defective in K+ uptake with a complementary DNA library from Arabidopsis thaliana. A 2.65-kilobase complementary DNA conferred ability to grow on media with K+ concentration in the micromolar range and to absorb K+ (or 86Rb+) at rates similar to those in wild-type yeast. The predicted amino acid sequence (838 amino acids) has three domains: a channel-forming region homologous to animal K+ channels, a cyclic nucleotide-binding site, and an ankyrin-like region.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Sentenac, H -- Bonneaud, N -- Minet, M -- Lacroute, F -- Salmon, J M -- Gaymard, F -- Grignon, C -- New York, N.Y. -- Science. 1992 May 1;256(5057):663-5.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Biochimie et Physiologie Vegetales, ENSA-M/INRA/CNRS URA 573, Montpellier, France.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/1585180" target="_blank"〉PubMed〈/a〉
    Schlagwort(e): Amino Acid Sequence ; *Arabidopsis Proteins ; Biological Transport ; Blotting, Southern ; Carrier Proteins/chemistry/genetics ; *Cloning, Molecular ; DNA/genetics ; Deoxyribonuclease EcoRI ; Gene Expression ; Kinetics ; Molecular Sequence Data ; Plant Proteins/chemistry/*genetics ; Plants/*genetics ; Potassium/*metabolism ; Potassium Channels/chemistry/*genetics ; Saccharomyces cerevisiae/*genetics ; Sequence Homology, Nucleic Acid
    Print ISSN: 0036-8075
    Digitale ISSN: 1095-9203
    Thema: Biologie , Chemie und Pharmazie , Informatik , Medizin , Allgemeine Naturwissenschaft , Physik
    Standort Signatur Erwartet Verfügbarkeit
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  • 99
    facet.materialart.
    Unbekannt
    American Association for the Advancement of Science (AAAS)
    Publikationsdatum: 1992-08-14
    Beschreibung: A pseudo--half-knot can be formed by binding an oligonucleotide asymmetrically to an RNA hairpin loop. This binding motif was used to target the human immunodeficiency virus TAR element, an important viral RNA structure that is the receptor for Tat, the major viral transactivator protein. Oligonucleotides complementary to different halves of the TAR structure bound with greater affinity than molecules designed to bind symmetrically around the hairpin. The pseudo--half-knot--forming oligonucleotides altered the TAR structure so that specific recognition and binding of a Tat-derived peptide was disrupted. This general binding motif may be used to disrupt the structure of regulatory RNA hairpins.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Ecker, D J -- Vickers, T A -- Bruice, T W -- Freier, S M -- Jenison, R D -- Manoharan, M -- Zounes, M -- New York, N.Y. -- Science. 1992 Aug 14;257(5072):958-61.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉ISIS Pharmaceuticals, Carlsbad, CA 92008.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/1502560" target="_blank"〉PubMed〈/a〉
    Schlagwort(e): Base Sequence ; Binding Sites ; DNA, Viral/metabolism ; Gene Products, tat/metabolism ; HIV/*genetics ; Kinetics ; Molecular Sequence Data ; *Nucleic Acid Conformation ; Oligoribonucleotides/*chemistry ; RNA, Viral/*chemistry/genetics/metabolism ; tat Gene Products, Human Immunodeficiency Virus
    Print ISSN: 0036-8075
    Digitale ISSN: 1095-9203
    Thema: Biologie , Chemie und Pharmazie , Informatik , Medizin , Allgemeine Naturwissenschaft , Physik
    Standort Signatur Erwartet Verfügbarkeit
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  • 100
    facet.materialart.
    Unbekannt
    American Association for the Advancement of Science (AAAS)
    Publikationsdatum: 1992-05-22
    Beschreibung: The growth-inhibiting peptide hormone somatostatin stimulates phosphotyrosine phosphatase activity in the human pancreatic cell line MIA PaCa-2. This hormonal activation was mediated by a pertussis toxin-sensitive guanosine 5'-triphosphate-binding protein (G protein) in the membranes of these cells. Activation of this G protein by somatostatin stimulated the dephosphorylation of exogenous epidermal growth factor receptor prepared from A-431 cells in vitro. This pathway may mediate the antineoplastic action of somatostatin in these cells and in human tumors and could represent a general mechanism of G protein coupling that is utilized by normal cells in the hormonal control of cell growth.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Pan, M G -- Florio, T -- Stork, P J -- New York, N.Y. -- Science. 1992 May 22;256(5060):1215-7.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Vollum Institute for Advanced Biomedical Research, Oregon Health Sciences University, Portland 97201.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/1350382" target="_blank"〉PubMed〈/a〉
    Schlagwort(e): Adenosine Triphosphate/metabolism ; Carcinoma, Squamous Cell ; Cell Line ; Cell Membrane/metabolism ; Dose-Response Relationship, Drug ; Enzyme Activation ; GTP-Binding Proteins/*metabolism ; Guanosine 5'-O-(3-Thiotriphosphate)/pharmacology ; Guanosine Diphosphate/analogs & derivatives/pharmacology ; Humans ; Kinetics ; Pancreatic Neoplasms ; Peptides/metabolism ; Pertussis Toxin ; Phosphorylation ; Protein Kinases/metabolism ; Protein Tyrosine Phosphatases/*metabolism ; Receptor, Epidermal Growth Factor/metabolism ; Somatostatin/*pharmacology ; Thionucleotides/pharmacology ; Virulence Factors, Bordetella/pharmacology
    Print ISSN: 0036-8075
    Digitale ISSN: 1095-9203
    Thema: Biologie , Chemie und Pharmazie , Informatik , Medizin , Allgemeine Naturwissenschaft , Physik
    Standort Signatur Erwartet Verfügbarkeit
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