Search results for "histamine"
showing 10 items of 254 documents
Structural and vibrational study of the tautomerism of histamine free-base in solution.
2003
Infrared and Raman spectroscopy in H(2)O and D(2)O and quantum Density Functional calculations were used to determine the structure of histamine free-base in aqueous solution. A quantum mechanical study of the tautomeric equilibrium of histamine free-base in solution was performed at the 6-311G level. Electronic correlation energies were included by using the hybrid functional B3LYP. The solvent was simulated as a continuum characterized by a dielectric constant, and the quantum system (solute) was placed in an ellipsoidal cavity. Solute-solvent electrostatic interaction was calculated by means a multipolar moment expansion introduced in the Hamiltonian. Four relevant histamine conformation…
Effects of naturally occurring dihydroflavonols from Inula viscosa on inflammation and enzymes involved in the arachidonic acid metabolism
2007
Abstract The anti-inflammatory properties of three flavanones isolated from Inula viscosa , sakuranetin, 7- O -methylaromadendrin, and 3-acetyl-7- O -methylaromadendrin, have been tested both in vitro and in vivo. Acute inflammation in vivo was induced by means of topical application of 12- O -tetradecanoylphorbol 13-acetate (TPA) to mouse ears or by subcutaneous injection of phospholipase A 2 (PLA 2 ) into mouse paws. The test compounds were evaluated in vitro for their effect on both the metabolism of arachidonic acid and on the release and/or activity of enzymes involved in the inflammatory response such as elastase, myeloperoxidase (MPO), and protein kinase C (PKC). The most active comp…
Histamine, an effective initiator for the synthesis of polysulfides
2020
The synthesis of polysulfides from thioepoxides traditionally makes use of toxic organometallic initiators. We demonstrate the use of histamine as an efficient initiator. The polymerization can be carried out under solvent-free and metal-free conditions at mild temperature to obtain high-quality polysulfides. A synergistic acid and base catalysis mechanism is proposed. The results enable a safer and cleaner production of next-generation polymers.
New antiasthmatic drugs from traditional medicine?
1991
Several plants are used in traditional medicine for the treatment of bronchial asthma. We are trying to identify the active compound(s) and their mode of action. For the isolation and identification of the active principles, different chromatographic methods, HPLC, MPLC, elementary analysis, UV, mass, <sup>1</sup>H- and <sup>13</sup>C-NMR spectroscopy are used. Whole plant extracts, fractionated extracts and pure compounds are tested in the following pharmacological systems: cyclooxygenase and lipoxygenase pathway of arachidonic acid metabolism, bronchial obstruction of guinea pigs after inhalation of allergens, platelet-activating factor (PAF), histamine or acetylch…
Struktur-Wirkungs-Beziehungen bei Histaminanaloga, 13. Mitt.: 5(4)-Cyclisch substituierte Histamine und Nα-Methyl-histamine
1976
Es wird die Darstellung von 5(4)-cyclisch substituierten Histaminen und Nα-Methyl-histaminen durch Cyclisierung von 1-aryl-substituierten 2-Brom-4-phthalimido-butan-1-onen mit Formamid oder Benzamidin und anschliesende Hydrolyse bzw. Reduktion der Zwischenprodukte beschrieben. C-5(4) Cyclic Substituted Histamines and Nα-Methylhistamines The preparation of C-5(4) cyclic substituted histamines and Nα-methylhistamines by cyclisation of 1-aryl-2-bromo-4-phthalimidobutan-1-ones with formamide or benzamidine, followed by hydrolysis or reduction of the intermediates, is described.
Effects of histamine on dentate granule cells in vitro
1990
Abstract Hippocampal slices from rat brain were exposed to histamine and related substances in a perfusion chamber. Granule cells of the dentate gyrus were studied with conventional extra- and intracellular recording and a single electrode voltage clamp. Histamine caused, through activation of H 2 -receptors, a small depolarization, an increase in the number of synaptic and action potentials, a block of the long lasting (but not the early) component of spike afterhyperpolarizations and a reduction of the accommodation of action potential firing. These effects were mimicked by forskolin (suggests activation of adenylate cyclase). In voltage clamp, histamine blocked a long lasting calcium-dep…
Effects of leflunomide on immune responses and models of inflammation.
1993
Leflunomide is an antiphlogistic and immunomodulating agent that has been shown to be effective in preventing and healing autoimmune disorders and reactions leading to organ graft rejection. From our preliminary clinical data [4], we now have hopes that these effects, observed in experimental animals, can truly be transferred to humans. Although we are far from understanding the mode of action of leflunomide, we are slowly gathering some insight. A good many of the immunosuppressive effects of leflunomide can be attributed to the antagonistic effects it has on responses to many cytokines, most likely through receptor expression and signal transduction (tyrosine kinase inhibition). The inhib…
Analysis of pharmaceutical preparations containing antihistamine drugs by micellar liquid chromatography
2005
Rapid chromatographic procedures for analytical quality control of pharmaceutical preparations containing antihistamine drugs, alone or together with other kind of compounds are proposed. The method uses C18 stationary phases and micellar mobile phases of cetyltrimethylammonium bromide (CTAB) with either 1-propanol or 1-butanol as organic modifier. The proposed procedures allow the determination of the antihistamines: brompheniramine, chlorcyclizine, chlorpheniramine, diphenhydramine, doxylamine, flunarizine, hydroxyzine, promethazine, terfenadine, tripelennamine and triprolidine, in addition to caffeine, dextromethorphan, guaifenesin, paracetamol and pyridoxine in different pharmaceutical …
Histamin in der Interstitialfl�ssigkeit der befallenen und klinisch nicht befallenen Haut bei chronisch rezidivierender Urticaria
1979
Bei 8 Patienten mit idiopathischer chronisch rezidivierender Urticaria wurden in der Periumbilicalregion Saugblasen gleichzeitig auf frischen urticariellen Herden und der unveranderten Haut daneben produziert und Histamin in der Blasenflussigkeit bestimmt. Hierzu wurde die von Siraganian entwickelte Methode der Autoanalyzer-Technik in modifizierter Form verwendet. Die Histaminspiegel lagen bei diesen Patienten in unveranderter Haut in derselben Grosenordnung wie bei 10 Normalpersonen, wahrend alle 8 Urticaria-Patienten hohere Histamin-Werte in den Urticae verglichen mit der nicht befallenen Haut aufwiesen; bei 4 der Patienten waren diese Unterschiede jedoch nur gering ausgepragt.
H1 antihistamīna bezrecepšu medikamentu aprite Rīgas aptiekā, laika posmā no 2014. gada 1.janvāra līdz 2014. gada 31. decembrim
2015
Pēdējo 20 gadu laikā alerģijas izplatība palielinājusies divas reizes un ar to saskaras gandrīz vai katrā ģimenē. Alerģija nav slimība, tā ir dažādu saslimšanu grupa, kuru pamatā ir kopējs patoloģisks process un kur galvenā loma ir cilvēka imūnajai sistēmai. Ja nav iespējams no alerģiju izraisītājiem (alergēniem) izvairīties, tad visbiežāk alerģisko izpausmju mazināšanai lieto perorālos vai vietējas darbības H1 antihistamīna līdzekļus. Bakalaura darba mērķis – noskaidrot H1 antihistamīna bezrecepšu medikamentu apriti Rīgas aptiekā laika posmā no 2014. gada 1. janvāra līdz 2014. gada 31. decembrim, ar anketēšanas palīdzību izvērtēt alerģijas izpausmju smaguma pakāpi, tās sezonalitāti un resp…