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  • 1
    Electronic Resource
    Electronic Resource
    Mutations in the high-affinity IgE receptor β-chain are not associated with nonresponder status (2005)
    Oxford, UK : Munksgaard International Publishers
    Allergy 60 (2005), S. 0 
    Details
    ISSN: 1398-9995
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: Background:  Basophils of some individuals do not release histamine upon activation of their high-affinity immunoglobulin E (IgE) receptor (FcRI), but do so if this receptor is circumvented for cell activation. This so-called nonresponder phenomenon is clinically relevant, because in various studies atopy was less frequent or absent in nonresponder individuals. So far, it is unknown if this phenomenon is acquired during adulthood or exists from birth on.Methods:  Histamine release was determined from isolated leucocytes stimulated with anti-IgE or calciumionophor. Also, random primed cDNA was synthesized and the open reading frame (ORF) of the FcRI β-subunit amplified and sequenced.Results:  In the first part of our study, we examined the role of atopic status, type of atopy, and age in a random population of 95 children of whom we found 22% to be nonresponder. None of these parameters correlated with the nonresponder status. Except for food allergy, no specific type of atopy correlated with histamine release. The mechanism underlying the nonresponder phenomenon is assumed to occur early in the signalling cascade. We hypothesized that mutations in the FcRI β-chain may be associated with the nonresponder status, and in the second part of our study sequenced the β-subunit in 20 responders and 20 nonresponders. Two conservative and two nonconservative heterozygous one base mutations (Thr179Thr, Asp216Asp, Ile147Leu and Glu237Gly) were found in two nonresponders and one responder. Three of these mutations have not been described so far.Conclusion:  The nonresponder phenomenon is present from birth on and genetically determined. In our population, it was not associated with age or the presence of atopy, and appeared not to be caused by mutations in the FcRI β-chain.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1398-9995.2005.00807.x
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  • 2
    Electronic Resource
    Electronic Resource
    Simplified synthesis of 5-mercaptouracil riboside derivatives (1982)
    s.l. : American Chemical Society
    The @journal of organic chemistry 47 (1982), S. 1769-1772 
    Details
    ISSN: 1520-6904
    Source: ACS Legacy Archives
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1021/jo00348a037
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  • 3
    Electronic Resource
    Electronic Resource
    Capillary gas chromatography of fatty acid methyl esters from human milk lipid subclasses
    Amsterdam : Elsevier
    Journal of Chromatography A 279 (1983), S. 549-553 
    Details
    ISSN: 0021-9673
    Source: Elsevier Journal Backfiles on ScienceDirect 1907 - 2002
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://linkinghub.elsevier.com/retrieve/pii/S0021-9673(01)93656-8
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  • 4
    Electronic Resource
    Electronic Resource
    The synthesis of piperolide and related compounds
    Amsterdam : Elsevier
    Tetrahedron Letters 20 (1979), S. 1627-1630 
    Details
    ISSN: 0040-4039
    Source: Elsevier Journal Backfiles on ScienceDirect 1907 - 2002
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://linkinghub.elsevier.com/retrieve/pii/S0040-4039(01)93609-3
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  • 5
    Electronic Resource
    Electronic Resource
    Facile triphenylphosphine deoxygenation of benzofuran dioxetanes, their epoxides and valence-isomeric quinone methides
    Amsterdam : Elsevier
    Tetrahedron Letters 35 (1994), S. 6063-6066 
    Details
    ISSN: 0040-4039
    Keywords: 2 ; 2 ; 2 ; 3-dimethylbenzofurans ; 3-dimethylindenes ; 3-dimethylindole ; Dimethyldioxirane ; deoxygenation ; dioxetanes ; epoxides ; phosphine ; phospholanes ; quinone methides ; singlet oxygen
    Source: Elsevier Journal Backfiles on ScienceDirect 1907 - 2002
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://linkinghub.elsevier.com/retrieve/pii/0040-4039(94)88076-X
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  • 6
    Electronic Resource
    Electronic Resource
    External hyphal production of vesicular-arbuscular mycorrhizal fungi in pasture and tallgrass prairie communities (1995)
    Springer
    Oecologia 103 (1995), S. 17-23 
    Details
    ISSN: 1432-1939
    Keywords: Mycorrhiza ; External hyphae ; Root morphology ; Grasslands ; Soil moisture
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract External hyphae of vesicular-arbuscular mycorrhizal (VAM) fungi were quantified over a growing season in a reconstructed tallgrass prairie and an ungrazed cool-season pasture. In both sites, hyphal lengths increased throughout the growing season. Peak external hyphal lengths were 111 m cm−3 of soil in the prairie and 81 m cm−3 of soil in the pasture. These hyphal lengths calculate to external hyphal dry weights of 457 μg cm−3 and 339 μg cm−3 of soil for prairie and pasture communities, respectively. The relationships among external hyphal length, root characteristics, soil P and soil moisture were also determined. Measures of gross root morphology [e.g., specific root length (SRL) and root mass] have a strong association with external hyphal length. Over the course of the study, both grassland communities experienced a major drought event in late spring. During this period a reduction in SRL occurred in both the pasture and prairie without a measured reduction in external hyphal length. Recovery for both the pasture and prairie occurred not by increasing SRL, but rather by increasing external hyphal length. This study suggests that growth is coordinated between VAM hyphae and root morphology, which in turn, are constrained by plant community composition and soil nutrient and moisture conditions.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00328420
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  • 7
    Electronic Resource
    Electronic Resource
    Influence of temperature on the sensitivity of the β-receptors and the contractility of guinea-pig atrium (1972)
    Springer
    Naunyn-Schmiedeberg's archives of pharmacology 275 (1972), S. 95-104 
    Details
    ISSN: 1432-1912
    Keywords: Temperature ; β-Receptors ; Guinea-Pig Atrium ; Affinity ; Adrenergic Drugs
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Using electrically stimulated guinea-pig atria the influence of temperature on the contractility and on the efficacy of some β-sympathomimetic and-lytic drugs, was studied. The following results were obtained. 1. Raising the temperature of the bath fluid from 25–42°C decreased significantly the developed amplitude of contraction under control conditions, whereas dT/dt max values were not altered. The maximal developed tension induced by the sympathomimetic drugs decreased at 42°C. The corresponding dT/dt max values, on the other hand, were increased by elevation of the temperature. 2. The dose-response curves of the sympathomimetic drugs isoprenaline (IPN), Th 1165a and orciprenaline (OPN) were shifted to the right when the temperature was increased from 25–42°C. The affinity of IPN at 33°C was found about 30- and 100-times higher than that of Th 1165a and OPN, respectively. 3. The β-adrenolytic drug pindolol (LB 46), as well as the cardioselective β-blocker, practolol, antagonized the β-sympathomimetic effects evoked by IPN and Th 1165a in a competitive manner. As indicated by the pA2 values, pindolol had a 100-times higher affinity than practolol. The present results lead to the conclusion that, on the guinea-pig atrium, the agonist β-receptor reaction depends on the metabolic rate of this organ.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00505070
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  • 8
    Electronic Resource
    Electronic Resource
    Sensitivity changes of adrenergic β-receptors induced by alterations of the metabolic state of isolated organs (1972)
    Springer
    Naunyn-Schmiedeberg's archives of pharmacology 275 (1972), S. 105-113 
    Details
    ISSN: 1432-1912
    Keywords: Sympathomimetic Affinity ; β-Receptors ; Temperature ; Metabolic State ; Isolated Organs
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Experiments on isolated organs-rabbit ileum, guinea-pig trachea and atrium — with different “β-receptor subtypes” were carried out in order to determine whether changes of the metabolic state or of the extracellular pH were able to alter the responsiveness of these receptors to sympathomimetic amines. 1. Guinea-Pig Atrium. Lowering of the pH of the bath fluid from 7.48 to 6.79 resulted in a significant decrease of the affinity of isoprenaline (IPN) calculated as the pD2-value. Metabolic inhibition induced by iodoacetic acid (IAA) (5×10−5 M) increased the affinity of Th 1165a. 2. Rabbit Ileum. The affinity of IPN was not changed by lowering the pH, even to values of 6.11. At this pH the spontaneous motility was already markedly impaired. IAA (2.4×10−5 M) caused a moderate increase in the affinity of IPN whereas those of Th 1165a and orciprenaline (OPN) were elevated 10-fold. 3. Guinea-Pig Trachea. Lowering of the pH caused a decrease of the pD2-values of IPN and in particular of Th 1165a. The metabolic inhibitor IAA had no influence upon the pD2 value of IPN. 4. The present results favour the existence of only one type of β-receptor which changes its sensitivity depending on the metabolic state. It seems therefore very likely that the affinity of sympathomimetic drugs depends not only on the structure of the β-receptor but also on the metabolic state of the tissue.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00505071
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  • 9
    Electronic Resource
    Electronic Resource
    Influence of papaverine and isoprenaline on contractility and cyclic AMP level of left guinea-pig atria at different rates of beat (1977)
    Springer
    Naunyn-Schmiedeberg's archives of pharmacology 299 (1977), S. 9-15 
    Details
    ISSN: 1432-1912
    Keywords: Papaverine ; Isoprenaline ; cAMP ; Contractility ; Frequency of stimulation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Responses to papaverine and isoprenaline on cyclic AMP and contractility were investigated in left atria of guinea-pigs driven at a rate of 0.5 or 2 Hz. 1. Studies on the time course of the effects of isoprenaline (3×10−8 M) showed that the increase in cAMP levels preceded the increase in contractile activity. cAMP increased to maximal values and then rapidly fell to the control levels with a similar time course both at 0.5 and 2 Hz. The contractile responses to isoprenaline, however, showed a different time course. The development of the inotropic response to isoprenaline occurred faster at 2 Hz than at 0.5 Hz. In contrast to the levels of cAMP maximal contractile responses were maintained throughout the presence of isoprenaline. 2. At a stimulation frequency of 2 Hz with increasing concentrations of papaverine (10−6 M, 3×10−6 M, 3×10−5 M) the cAMP content increased dose-dependently. However, no correlation between the effects on cAMP and contractility could be established since 3×10−5 M papaverine already reduced contractile amplitude. The same concentration of papaverine slightly depresssed the inotropic responses to isoprenaline whereas it considerably enhanced the effects of isoprenaline on cAMP. 3. At a stimulation frequency of 0.5 Hz papaverine produced similar effects on the basal cAMP level and the cAMP responses to isoprenaline as at 2 Hz. However, papaverine increased significantly cardiac contractility and potentiated the positive inotropic effects of isoprenaline. At this rate of stimulation a linear relationship between the positive inotropic effect and the increase in cAMP as produced by increasing concentrations of papaverine (10−6 M, 3×10−6 M, 3×10−5 M) was obtained. The dissociation of the effects of papaverine on contractility and cAMP seems to be related to a calcium antagonistic property which—in addition to the inhibition of phosphodiesterase—comes into play at higher rates of beat and inhibits the effects of elevated cAMP on myocardial contractility.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00508631
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  • 10
    Electronic Resource
    Electronic Resource
    Stimulation by phenylephrine of adrenergic alpha- and beta-receptors in the isolated perfused rabbit heart (1974)
    Springer
    Naunyn-Schmiedeberg's archives of pharmacology 282 (1974), S. 307-310 
    Details
    ISSN: 1432-1912
    Keywords: Isolated Perfused Rabbit Heart ; Phenylephrine ; dp/dt max ; Heart Rate ; Adrenolytic Drugs
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary In the isolated perfused rabbit heart the effect of phenylephrine on the left ventricular dp/dt max and on heart rate was investigated. 1. The positive inotropic effect of phenylephrine 3×10−7 to 3×10−6 M was abolished by the α-adrenolytic drug phentolamine (3×10−6 M), whereas the β-adrenolytic drug pindolol (10−8 M) was ineffective. On the other hand, the positive inotropic effect evoked by higher concentrations (10−5 to 10−4 M) of phenylephrine was blocked by pindolol while phentolamine was without any effect. 2. The positive chronotropic effect of phenylephrine was antagonized by pindolol. Phentolamine was ineffective. 3. The results presented here show that the ventricular myocardium of the rabbit contains both β- and α-adrenoceptors responsible for the mediation of the positive inotropic effect of phenylephrine.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00501238
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