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  • 1990-1994  (8)
  • Organic Chemistry  (3)
  • Inorganic Chemistry  (2)
  • Polymer and Materials Science  (2)
  • Fluorochrome-labeled capillaries
  • Liesegang rings
  • 1
    Electronic Resource
    Electronic Resource
    Springer
    Naunyn-Schmiedeberg's archives of pharmacology 351 (1994), S. 99-106 
    ISSN: 1432-1912
    Keywords: Key words Lung perfusion ; Bupivacaine ; Fluorochrome-labeled capillaries ; First-pass retention ; Inulin ; Tritium-labeled water
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract The ability of rat lung to remove the local anaesthetic drug bupivacaine from the blood was studied in isolated organs which were perfused either in an open (single-pass mode) or in a closed system (recirculating medium). Isolated perfused rat lungs exhibited a very low capacity to metabolize bupivacaine within 3 h during which the drug circulated continuously through the organ. The clearance values differed only by 0.2 ml/min from the control parameters in sham perfusions. The calculated extraction ratio was 0.2% and the elimination half-life was about 210 min. The volume of distribution of bupivacaine was 133 ml which remarkably surmounted the reference values obtained for sham perfusions. The distribution of bupivacaine into the pulmonary tissue was investigated applying the multiple indicator dilution technique to isolated lungs perfused in the single-pass mode. The mean elimination time of model compounds for distribution into the intravascular space, 14C-inulin, and the total water space, 3H-water, were 68 and 75 s at a flow rate of 6 ml/min. The volume of distribution was 5.9 ml for inulin and 6.5 ml for water. The mean transit time for concomitantly injected bupivacaine was 221 s and the volume of distribution was 14.4 ml. The respective parameters of sham perfusions performed without an isolated organ were substantially lower, i.e. mean elimination time 50, 50 and 61 s and distribution volume 4.9, 5.0 and 6.1 ml for inulin, water and bupivacaine. The volume of distribution during single-pass contact of bupivacaine to lung was not substantially influenced by an increase of the flow rate from 6 to 9 and 12 ml/min whereas the mean transit time dropped from 221 to 121 and 108 s, respectively. These results support the assumption that bupivacaine is extensively retained by the pulmonary tissue and that elimination of bupivacaine by metabolism can be neglegted for lung. The hemodynamic parameters of bronchiolar perfusion in the artificially perfused lung were determined using two fluorochrome-labeled macromolecular proteins, i.e. fluorescein-isothiocyanate (FITC)- and lissamine-rhodamine-B 200 (RB 200)-labeled globulin. After 10 min of perfusion at a flow rate of 12 ml/min in the closed system an area of 10.8% of the peribronchiolar tissue area contained the dye-label FITC. A very similar index (10.1%) of dye-coloured capillaries was obtained when the lungs of anaesthetized rats were examined 10 min after intravenous injection of the fluorochrome into the pulmonary artery in vivo. In isolated perfused rat lungs receiving both FITC and RB 200 59.5% of FITC-labeled capillaries were reached by the second fluorochrome within 2 s. This fraction accounted for 93.3% after 10 s of circulation time. This proves that isolated rat lungs were well perfused in vitro.
    Type of Medium: Electronic Resource
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  • 2
    ISSN: 0009-2940
    Keywords: Bis(phosphido)-bridged diiron hexa(penta)carbonyl complexes, molecular structures ; Steric strain ; Iron-iron double bond ; Calculations, EHT ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: An Unusual Pair of Bis(phosphido)-Bridged Diiron Carbonyl Complexes: [Fe2(CO)n{μ-P(tBu)2}(μ-PCy2)] (n = 5 and 6)Treatment of Na[Fe2(CO)6(μ-CO){μ-P(tBu)2}] with Cy2PCl gives [Fe2(CO)6{μ-P(tBu)2}(μ-PCy2)] (1) which loses CO on heating in toluene to afford [Fe2(CO)5{μ-P(tBu)2}(μ-PCy2)] (2). Complexes 1 and 2 have been characterized spectroscopically and by X-ray analyses. The central Fe2P2 unit in 1 is exactly planar whereas in 2 it is somewhat folded.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
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  • 3
    ISSN: 0899-0042
    Keywords: chromatographic resolution of stereoisomers ; molecular modelling ; conformation ; κ-opiate receptor ; Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The four stereoisomers of the two peripherally selective κ-opioid agonists EMD 60 400 and EMD 61 753 were synthesized, tested for stereoisomeric purity, and examined for affinity to the κ opioid receptor. The relationships between the configuration of these molecules and their biological activity are discussed. © 1994 Wiley-Liss, Inc.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
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  • 4
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Chemie Ingenieur Technik - CIT 62 (1990), S. 183-190 
    ISSN: 0009-286X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Development of chemical engineering - A survey. This article describes the scientific and technological origins of chemical engineering and the concept of chemical technology. The paradigm of unit operations was the result of mass production, continuous and catalytic processes, and knowledge of physical chemistry. The evolution of theory and the institutionalization of chemical engineering are described as constitutive elements.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
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  • 5
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Chemie Ingenieur Technik - CIT 64 (1992), S. 794-794 
    ISSN: 0009-286X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Type of Medium: Electronic Resource
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  • 6
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 619 (1993), S. 859-864 
    ISSN: 0044-2313
    Keywords: 2,2-Bis(diisopropoxyphosphonyl)propyl methyltin dibromide ; synthesis ; crystal structure ; n.m.r. data ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Molecular Structure of 2,2-Bis(diisopropoxyphosphonyl)propyl Methyltin DibromideBy methylation of Me3SnCH2CH[P(O)(OPr-i)2]2 with NaH/MeI Me3SnCH2C(Me)[P(O)(OPr-i)2]2 (1) is obtained, which is converted by bromine into the dibromide MeBr2SnCH2C(Me)[P(O)(OPr-i)2]2 (2). An X-ray crystal structure analysis shows 2 to be monomeric. The tin atom is situated in the centre of a distorted octahedron, in which the functional substituent is intramolecular coordinated as tridentate ligand in a facial mode. The two organo groups are arranged in trans-position (C—Sn—C 155.1°), whereas the oxygen and bromine atoms are orientated cis to each other. The six-membered ring of the bicyclic molecular fragment of 2 which results from the coordination of the functional organo group to the tin atom shows a boat-conformation, whereas the two five-membered rings exist in twist-conformations. Multinuclear n.m.r. and i.r. data show that 2 retains its solid state structure also in nonpolar solvents.
    Notes: Durch Methylierung von Me3SnCH2CH[P(O)(OPr-i)2]2 mittels NaH/MeI erhält man Me3SnCH2C(Me)[P(O)(OPr-i)2]2 (1), das mit Brom in das Dibromid MeBr2SnCH2C(Me)[P(O)(OPr-i)2]2 (2) überführt wird. Nach der Röntgenkristallstrukturanalyse ist 2 im Festkörper monomer. Das Zinnatom befindet sich im Zentrum eines verzerrten Oktaeders, in dem der funktionelle Substituent intramolekular als tridentater Ligand in facialer Anordnung koordiniert ist. Die beiden Organoreste sind trans-ständig angeordnet (C—Sn—C 155,1°), während sich die Sauerstoff- und Bromatome in cis-Anordnung zueinander befinden. Der Sechsring des aus der Koordination des funktionellen Organorestes am Zinnatom resultierenden bicyclischen Molekülfragmentes von 2 weist Wannenkonformation auf, während die beiden Fünfringe in Twist-Konformationen vorliegen. Multikern-NMR- und IR-Daten belegen, daß 2 seine Festkörperstruktur auch in unpolaren Lösungsmitteln beibehält.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
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  • 7
    ISSN: 0170-2041
    Keywords: Azapeptides ; Renin inhibitor ; Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: A highly potent renin inhibitor of the azapeptide type (2) is synthesized by starting from the hydrazine derivative 3. This peptide analogue inhibits renin in the same range (nanomolar) as its purely peptidic original 2a, but reveals much higher specificity for renin than 2a does.
    Additional Material: 1 Tab.
    Type of Medium: Electronic Resource
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  • 8
    ISSN: 0268-2605
    Keywords: Organolead ; organomercury ; organotin ; toxicity ; lipid metabolism ; arachidonic acid ; Lands cycle ; cell culture ; HL-60 cells ; Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The concentration of free fatty acids within cells is mainly dependent upon the following enzyme activities: liberation by phospholipase A2 (PLA2), activation of free acids by acyl-CoA-synthetase and re-esterification by lysophospholipid acyltransferase (LAT). In many cell types, especially those of the haematopeotic system, this deacylation-reacylation cycle (‘Lands cycle’) plays an important role in the regulation of free fatty acid concentration, above all that of arachidonic acid.We have shown here that heavy-metal compounds affect this cycle mainly at two points and thereby lead to an increase of free fatty acids. On the one hand, organometals cause an inhibition of the reacylation of lysophospholipids; and on the other, the induction of PLA2 activity produces the same result. All compounds investigated such as methylmercury chloride (MeHgCl), diethyltriethyl-, and trimethyl-lead chloride (Et2PbCl2, Et3PbCl, Me3PbCl) as well as trimethyltin chloride (Et3SnCl) and di-t-butyltin dichloride (t-Bu2SnCl2) show at least one of these effects. In the case of Et3PbCl, the use of PLA2-inhibitors or pertussis toxin causes a drastic decrease in the amount of arachidonic acid liberated. These experiments demonstrate that the organometallic compounds inhibit the reacylation and/or stimulate the deacylation of fatty acids that are involved in many important biological or pathological mechanisms. The results suggest that in differentiated HL-60 cells the organometal compounds stimulate the Lands cycle by increasing the activity of the PLA2, possibly via a signal-transduction mechanism, and this effect is intensified via an inhibition of reesterification.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
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