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  • 1
    Electronic Resource
    Electronic Resource
    Effects of toxin II from the scorpion Androctonus australis Hector on sodium current in neuroblastoma cells and their modulation by oleic acid (1989)
    Springer
    European biophysics journal 16 (1989), S. 351-356 
    Details
    ISSN: 1432-1017
    Keywords: Neuroblastoma cell ; sodium current ; alpha scorpion toxin ; oleic acid ; whole cell patch clamp
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Physics
    Notes: Abstract The effects of toxin II (AaH II) isolated from the scorpion Androtonus australis Hector on sodium current in neuroblastoma X glioma NG 108-15 hybrid cells were analysed under patch clamp conditions in the whole cell configuration. AaH II (70 nM)_induced a maintained sodium current, as well as increasing both fast and slow inactivation time constants and the amplitude of the peak current. This latter effect occurred via a shift of the activation-voltage curve towards negative voltage values by about 9 mV. Oleic acid (5 μM), which had no effect on INa under control conditions, decreased the AaH II-induced maintained current. It also reversed, or prevented the increase of the peak current induced by AaH II. However, it neither prevented nor modified the AaH II-induced increase in inactivation time constants. The binding of the toxin to its specific site and the number of binding sites for AaH II were not significantly modified by oleic acid. The oleic acid-induced effects could not be related to the activation of protein kinase C since PMA, a potent activator of this enzyme, did not produce oleic acid-like effects. From these results, it is concluded that AaH II has several independent effects on sodium channels, some of which could be modulated by the lipid environment of sodium channels in the membrane.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00257883
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  • 2
    Electronic Resource
    Electronic Resource
    Structural selectivity of topological indexes in alkane series (1985)
    s.l. : American Chemical Society
    Journal of chemical information and modeling 25 (1985), S. 23-27 
    Details
    ISSN: 1520-5142
    Source: ACS Legacy Archives
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1021/ci00045a006
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  • 3
    Electronic Resource
    Electronic Resource
    Structure de la tétra(p-n-octylphényl)-5,10,15,20 porphine de zinc(II) (1988)
    Oxford [u.a.] : International Union of Crystallography (IUCr)
    Acta crystallographica 44 (1988), S. 429-432 
    Details
    ISSN: 1600-5759
    Source: Crystallography Journals Online : IUCR Backfile Archive 1948-2001
    Topics: Chemistry and Pharmacology , Geosciences , Physics
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1107/S0108270187010849
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  • 4
    Electronic Resource
    Electronic Resource
    Grid stage modelling functions and molecular vector graphics (1986)
    Springer
    The visual computer 2 (1986), S. 367-378 
    Details
    ISSN: 1432-2315
    Keywords: Molecular polymodelling ; POLYMOD ; 3D Grid stage ; COOBOX ; Geometric and Boolean operations ; Composite images
    Source: Springer Online Journal Archives 1860-2000
    Topics: Computer Science
    Notes: Abstract A polymodelling system (POLYMOD) is presented for varied 2D or 3D displays of chemical shapes, whether structural (molecular volumes distances, surfaces...) or electronic (molecular electrostatic potential, electron densities ...). The POLYMOD system manages reversible correspondences between calculation and representation spaces by immersing the molecules studied in a unique represetation space structured by a 3D grid box. This box, called COOBOX, defined by its point internal coordinates, is used to transform other coordinates into its own. Direct multi-slice images along thex, y, z axis provide access to a variety of derived operations around a molecular shape or set of shapes disposed in various manners. Interactive sub systems ensure Boolean operations and compare property shapes through the 3D grid. Clear separation of graphic routine and of downstream modelling programs leads to rapid and original generation of varied images (subimages, direct or composite images) which are then available for simulation strategies.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01952421
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  • 5
    Electronic Resource
    Electronic Resource
    Chiral liquid crystalline side chain polymers (1985)
    Springer
    Polymer bulletin 14 (1985), S. 179-186 
    Details
    ISSN: 1436-2449
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Summary Optically active liquid crystalline side chain polymers with dif ferent flexible spacer groups (n=2–11) and different main chains (acry lates, methacrylates and α chloroacrylates) are described. (+)-2-methyl butyloxyphenyl esters of benzoic acid were chosen as the mesogenic group.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00708478
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  • 6
    Electronic Resource
    Electronic Resource
    Pharmacokinetics and metabolism of hexamethylmelamine in mice after IP administration (1986)
    Springer
    Cancer chemotherapy and pharmacology 18 (1986), S. 226-230 
    Details
    ISSN: 1432-0843
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The pharmacokinetics of hexamethylmelamine (HMM) and its first metabolite (hydroxymethylpentamethylmelamine HMPMM) following IP bolus dose of 200 mg/kg were studied in mice. The drug concentrations were determined by a sensitive reversed-phase HPLC assay. Thus, for the first time, HMM major hydroxylated and demethylated metabolite plasma levels canbedetermined at the same time. Pharmacokinetic data were analyzed by an original method using a nonlinear cost function minimized by a simplex algorithm. An important property of this computer program is that convergence is ensured in contrast to linear or nonlinear least-square regression analysis, which leads to lack of convergence or to false convergence. Both HMM and HMPMM data fit a one-compartment open model. The parameters obtained indicate that the parent drug would probably be rapidly and completely transformed by the human body into HMPMM.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00273391
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  • 7
    Electronic Resource
    Electronic Resource
    Pharmacokinetics and metabolism of hexamethylmelamine in mice bearing renal cell tumors (1988)
    Springer
    Cancer chemotherapy and pharmacology 22 (1988), S. 282-288 
    Details
    ISSN: 1432-0843
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The pharmacokinetics of hexamethylmelamine (HMM) and its main metabolites hydroxymethylpentamethylmelamine (HMPMM), pentamethylmelamine (PMM), and 2,2,4,6 tetramethylmelamine (2,2,4,6 TetrMM) were studied in renal cell (RC) tumor tissues and plasma of CDF1 mice that had received IP bolus injections of the maximally tolerated dose (200 mg/kg) of HMM. HMM, PMM, and 2,2,4,6 Tetr MM concentrations determined in RC tissues were much higher than the plasma values, as indicated by the pharmacokinetic parameters (Cmax and AUC). On the other hand, very low levels of HMPMM, generally considered to be a potentially active antitumor compound, were detected in the target tissues, whereas this hydroxylated metabolite was stable and easily determined in plasma. High HMM concentrations in RC tissues could correlate with the high sensitivity of the tumor to this drug. However, the behavior of HMPMM remains unclear; related hypotheses are presented in this paper.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00254232
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  • 8
    Electronic Resource
    Electronic Resource
    Cooperativity of tetrodotoxin action in the frog node of Ranvier (1985)
    Springer
    Pflügers Archiv 405 (1985), S. 237-243 
    Details
    ISSN: 1432-2013
    Keywords: Node of Ranvier ; Na channels ; Tetrodotoxin ; Cooperativity
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract 1. The steady state effects and rates of action of tetrodotoxin (TTX) on sodium current were studied in the voltage clamped frog node of Ranvier. 2. Inactivation of the sodium current was separated into fast and slow phases. Both phases were assumed to correspond to two different currents (fast and slow) flowing through fast and slow channels (Benoit et al. 1985). 3. The dose-response curve of the steady state effect of tetrodotoxin on the fast current was sigmoid. An analysis of this effect in double logarithmic coordinates gave a Hill coefficient of 1.74. 4. The rates of tetrodotoxin action on the fast current were determined by the reversible reduction of the peak current recorded at a potential (+20 mV) at which the slow current was relatively small. 5. After an initial delay, the onset of TTX effect followed an exponential function of time whose constant decreased with increasing tetrodotoxin concentrations. Expressed as the time corresponding to a reduction of 2% of the current, the delay (δt2%) increased from about 100 ms with 300 nM-TTX to about 30 s with 1 nM-TTX. 6. When tetrodotoxin was removed, the offset developed quasi-instantaneously and followed an exponential function of time whose constant was independent of the toxin concentration. 7. Both steady state and rates of tetrodotoxin effects could be fitted well if one assumed that the block of one fast channel occurred after binding of two TTX molecules to two cooperative sites.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00582567
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  • 9
    Electronic Resource
    Electronic Resource
    Radiation necrosis of the brain: Time of onset and incidence related to total dose and fractionation of radiation (1985)
    Springer
    Neuroradiology 27 (1985), S. 44-47 
    Details
    ISSN: 1432-1920
    Keywords: Radiation therapy ; radiation injuries ; radiation dose-interval of onset ; incidence ; brain tumor
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Clinical deterioration during or after brain irradiation may be due to progression of neoplasm or radiation induced necrosis of the neoplasm and/or of normal brain tissues, or a combination of all. Eight patients with histologically documented radiation induced lesions of the brain are included in this study. The radiation therapy included the fractional schedule, group A, who received 280 to 300 rads daily, to a total dose of 4500 to 5000 rads and weekly exposure did not exceed 900 rads. Group B patients were exposed to 850 rads, daily dose on day 1, 3, 21 and 23 to a total dose of 3400 rads. The incidence of radiation induced lesions of brain was 3.4% in patients group A and 8.7% in group B patients (without) statistical significance). The median time of onset of these lesions after completion of radiation therapy was significantly shorter in group B patients (8.5 months) as opposed to group A patients (21 months).
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00342516
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  • 10
    Electronic Resource
    Electronic Resource
    Chloramine-T-induced modifications of K+ channel inactivation in neuroblastoma cells (1989)
    Springer
    Pflügers Archiv 414 (1989), S. S127 
    Details
    ISSN: 1432-2013
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00582264
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