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  • 1
    Electronic Resource
    Electronic Resource
    Procaine in Cardioplegia: Does It Affect the Endothelial Function? (2002)
    350 Main Street , Malden , MA 02148 , USA. , and 9600 Garsington Road , Oxford OX4 2DQ , England . : Blackwell Science Inc
    Journal of cardiac surgery 17 (2002), S. 0 
    Details
    ISSN: 1540-8191
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: Objective: Cardioplegic solutions are widely used in cardiac surgery and hyperkelemia in cardioplegia has been demonstrated to impair the endothelium-derived hyperpolarizing factor (EDHF)-mediated endothelial function. The present study examined the effect of procaine in St. Thomas Hospital Cardioplegia on the EDHF-mediated response in porcine coronary arteries. Methods: Isometric force study: Porcine coronary micro-arteries were studied in a myograph. Two rings taken from the same artery (diameter 200–450 μm, n = 8) were incubated with Kreb's solution as control or Kreb's solution plus procaine (1 mM) at 37 °C for 1 h, respectively. The EDHF-mediated relaxation was induced by bradykinin (BK, −10 ∼−6.5 log M) in the presence of indomethacin (Indo, 7 μM), NG-nitro-L-arginine (L-NNA, 300 μM), and hemoglobin (HbO, 20 μM) after U46619-precontraction (−8 log M). Electrophysiological study: The membrane potential of a single smooth muscle cell in coronary arteries was measured by a microelectrode after superfusion with Kreb's solution or Kreb's containing procaine (1 mM) for 1  h. Results: Procaine had little effect on the resting force of porcine coronary micro-arteries (0.94 ± 0.74 mN vs. 0.67 ± 0.23 mN in control, P 〉 0.05) and did not alter the U46619-induced precontraction (10.7 ± 1.7 mN vs. 12.0 ± 1.7 mN, P 〉 0.05). The BK-induced, EDHF-mediated relaxation was increased by the treatment with procaine with the EC50 shifted leftward (97.3 ± 0.6% vs. 83.0 ± 5.1% at −7 log M and 99.4 ± 0.6% vs. 96.7 ± 1.6% at −6.5 log M, P 〈 0.05; EC50: −8.57 ± 0.24 vs. −7.92 ± 0.23 log M, P 〈 0.05). Procaine slightly depolarized the smooth muscle cell (−56.3 ± 1.0 vs. −59.3 ± 0.7 mV, P 〉 0.05) and decreased the BK-induced hyperpolarization from −70.3 ± 0.4 mV to −68.0 ± 0.8 mV (−7 log M, P 〈 0.05) and from −72.3 ± 0.7 mV to −68.8 ± 0.8 mV (−6.5 log M, P 〈 0.01). Conclusions: In the coronary arteries, procaine has depolarizing effect but it enhances the EDHF-mediated relaxation. Therefore, addition of procaine in cardioplegia may preserve the EDHF-mediated endothelial function.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1046/j.1540-8191.2002.101432.x
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  • 2
    Electronic Resource
    Electronic Resource
    Impaired EDHF-Mediated Relaxation in Porcine Pulmonary Micro-Arteries by Cold Storage with University of Wisconsin and Euro-Collins Solutions (2002)
    350 Main Street , Malden , MA 02148 , USA. , and 9600 Garsington Road , Oxford OX4 2DQ , England . : Blackwell Science Inc
    Journal of cardiac surgery 17 (2002), S. 0 
    Details
    ISSN: 1540-8191
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: Background: Vascular endothelium plays a key role in regulation of vascular tone. Hyperkalemia has been demonstrated to impair the EDHF-mediated endothelial function in coronary circulation. University of Wisconsin (UW) and Eruo-collins (EC) solutions are used for organ preservation in transplantation surgery. The potassium concentration in UW or EC solutions is as high as 125 mmol/L or 115 mmol/L, respectively. This study was designed to examine whether hyperkalemia or storage with UW and EC solutions affects the relaxation mediated by EDHF in the porcine pulmonary micro-arteries. Methods: Porcine pulmonary micro-artery rings (diameter 200–450 μm) were studied in myograph (n = 8 in each group). After incubation with hyperkalemia (K+ 125 mmol/L, at 37° C), UW or EC solutions (at 4° C for 4 hours), EDHF-mediated relaxation induced by bradykinin (BK, −10 to −6.5 log M) in the presence of inhibitors for cyclooxygenase (Indomethacin, 7 μM), nitric oxide synthase (NG-nitro-L-arginine, 300 μM), and oxyhemoglobin (20 μM) was compared with control (Krebs' solution) in precontraction with U46619 (−7.5 log M). Results: The EDHF-mediated relaxation to BK was 69.6 ± 6.3% compared with 97.1 ± 1.7% (p= 0.003) in control (no inhibitors). After incubation with hyperkalemia, the relaxation significantly decreased (38.6 ± 3.0% vs. 59.1 ± 7.4%, p= 0.03). Storage with UW or EC solutions also significantly decreased the relaxation (49.3 ± 7.3% vs. 65.2 ± 3.5%, p= 0.04 and 51.9 ± 8.4% vs. 60.3 ± 6.1%, p= 0.02, respectively). Conclusions: In porcine pulmonary micro-arteries, exposure to hyperkalemia or storage with UW or EC solutions at 4°C for 4 hours impairs the EDHF-mediated endothelial function. The clinical significance of this effect should be further studied.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1046/j.1540-8191.2002.10147.x
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  • 3
    Electronic Resource
    Electronic Resource
    Different Role of Epoxyeicosatrienoic Acids (EET11,12) in Endothelium-Derived Hyperpolarizing Factor-Mediated Relaxation in Porcine Coronary and Pulmonary Micro-Arteries (2002)
    350 Main Street , Malden , MA 02148 , USA. , and 9600 Garsington Road , Oxford OX4 2DQ , England . : Blackwell Science Inc
    Journal of cardiac surgery 17 (2002), S. 0 
    Details
    ISSN: 1540-8191
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: Objectives: Endothelium-derived hyperpolarizing factor (EDHF) plays a key role in vasorelaxation and the cytochrome P450-monooxygenase metabolites of arachidonic acid epoxyeicosatrienoic acids (EETs), such as EET11,12, have been suggested to be EDHF in various vasculatures. However, little is known about the role of EET11,12 in the coronary and pulmonary circulation, especially in microcirculation. The present study was designed to examine the role of EET11,12 in porcine coronary and pulmonary micro-arteries. Methods: Porcine coronary and pulmonary micro-arteries (diameter 200-450 μm) were studied in a myograph (n = 8 in each group). The artery rings were set at the 90% of the circumference at 100 mm Hg for coronary or 30 mm Hg for pulmonary micro-arteries, respectively. After precontraction with U46619 (−8.2 log M for coronary and −7.5 log M for pulmonary micro-arteries), EET11,12 (−10 ∼−6.5 log M) or bradykinin (BK, −10 ∼−6.5 log M)-induced relaxation was established in the presence of inhibitors for cyclooxygenase (indomethacin, 7 μM), nitric oxide (NO) synthetase (NG-nitro-L-arginine, 300 μM), and NO scavenger oxyhemoglobin (20 μM). Results: EET11,12 induced a dose-dependent relaxation in coronary micro-arteries with the maximal relaxation of 18.3 ± 3.3% that was significantly less than the relaxation induced by BK (72.5 ± 7.8%; P 〈 0.001). In contrast, in pulmonary micro-arteries, BK induced a marked relaxation (69.6 ± 6.3%) whereas EET11,12 did not have any effect. Conclusion: In porcine coronary micro-arteries, EET11,12 may partially mimic the action of EDHF whereas in pulmonary arteries, this substance is unlikely involved in the EDHF-mediated relaxation.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1046/j.1540-8191.2002.101433.x
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  • 4
    Electronic Resource
    Electronic Resource
    Determination of Interaction Mechanism of Sensorgrams by Analysis of Binding Kinetics (1999)
    Springer
    The protein journal 18 (1999), S. 709-719 
    Details
    ISSN: 1573-4943
    Keywords: Biosensor ; adenylate kinase ; monoclonal antibody ; inhomogeneous ; rebinding
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract We monitored the interactions between pairs of molecules where the antigen adenylate kinase (AK) was immobilized on the surface of a chip and the antibody against AK, McAb3D3, was in solution. The association data that we obtained were not always accurately described by the expected pseudo-first-order reaction mechanism. A better description of the association data was achieved with a double-exponential function. Various models were applied to describe these observations: mass transport-controlled processes, inhomogeneous immobilized ligands, or inhomogeneous soluble analytes. Inhomogeneous immobilized ligands seemed to be the most likely explanation for the observed biphasic association kinetics. We simulated the kinetics of the SPR signal under the above-mentioned conditions. Plots of dR/dt versus R of the association phase showed characteristic differences between those nonlinearities resulting from mass transport limitation and those from inhomogeneous ligands. The plots of dR/dt versus R of McAb3D3 binding to immobilized AK show positive curvatures, indicating that the observed biphasic association kinetics is due to the inhomogeneity of the immobilized ligands. This is consistent with the results obtained from the comparison of various model fittings.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1020666509604
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  • 5
    Electronic Resource
    Electronic Resource
    Allylmalonamide as a bivalent linker: Synthesis of biantennary GM3-saccharide—Keyhole limpet hemocyanin glycoconjugate and the immune response in mice (1999)
    Springer
    Glycoconjugate journal 16 (1999), S. 507-515 
    Details
    ISSN: 1573-4986
    Keywords: GM3 antigen ; sialyllactoside ; biantennary ; glycoconjugate ; antibody ; CTP, Cytidine 5′-triphosphate ; KLH, Keyhole Limpet Hemocyanin ; M2C2H, 4-(4-N-maleimidomethyl) cyclohexane-1-carboxyl hydrazide ; MPL, Monophosphoryl lipid A ; Sulfo-GMBS, N-(γ-maleimidobutyryloxy) sulfosuccinimide ester ; BSA, Bovine serum albumin ; HSA, Human serum albumin ; GBSPIa (GBSPIII), Type Ia (III) group B Streptococcus polysaccharide
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract A biantennary GM3-saccharide (sialyllactoside) derivative (4) was constructed using allylmalonic acid as a bivalent linker, both carboxylic acids of which were condensed with 3-aminopropyl lactoside (2) prior to enzymatic sialylation with a fusion enzyme. While ozonolysis of its allyl group generated a saccharide having a terminal aldehyde (6), we were unable to couple 6 directly to protein by reductive amination. However, extension of the spacer by means of introducing a maleimide group to 6 through its aldehyde group to give 7 enabled the latter to be successfully coupled to thiolated proteins. The average ratios of saccharide to protein were observed to be 35 in KLH conjugate (13) and 9–12 in HSA conjugates (14 and 15). The antisera obtained by immunizing mice with the biantennary sialyllactoside-KLH conjugate (13) together with MPL adjuvant were analyzed by ELISA. Using several structurally related saccharide-HSA conjugates as screening antigens, it was concluded that anti-sialyllactoside antibodies, both IgG and IgM, were effectively raised. This was further supported by competitive inhibition experiments using lactoside (1), sialyllactoside (8) and biantennary sialyllactoside (4) as inhibitors.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1007069904462
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  • 6
    Electronic Resource
    Electronic Resource
    Carboxymethyl-histaminocarbonylmethylamylose as a mimetic system of chymotrypsin in the catalytic hydrolysis of esters (1989)
    New York : Wiley-Blackwell
    Die Makromolekulare Chemie 190 (1989), S. 1531-1536 
    Details
    ISSN: 0025-116X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: A new type of polysaccharide host, carboxymethyl-histaminocarbonylmethylamylose (2b), containing carboxylic, imidazolyl and hydroxyl groups in the backbone, was used as a mimetic system for chymotrypsin in the catalytic hydrolysis of 3-acetoxy-N-dodecylpyridinium iodide (1). The substrate is located in the hydrophobic cavity of the amylose helix. The apparent saturation, the entropy-favored kinetics and the pronounced catalytic efficiency (9 times higher than that of a system consisting of the same concentration of carboxymethylamylose and histamine) show that 2b is a good enzyme model in which the definite binding site, active center and self-organization characteristics are present. Most distinctly, the pH-rate constant profile of the hydrolysis of 1 and 2b is of bell-type and has an optimum at pH 7,98, which is very close to 7,90 for chymotrypsin. In conclusion, the charge relay mechanism is also involved in the catalytic effect of 2b.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/macp.1989.021900704
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