Search results for "histamine"

Omalizumab rapidly improves angioedema-related quality of life in adult patients with chronic spontaneous urticaria: X-ACT study data

2018

Background The X-ACT study aims to examine the effect of omalizumab treatment on quality of life (QoL) in chronic spontaneous urticaria (CSU) patients with angioedema refractory to high doses of H1-antihistamines. Methods In X-ACT, a phase III, double-blind, placebo-controlled study, CSU patients (18–75 years) with ≥4 angioedema episodes during the 6 months before inclusion were randomized (1:1) to receive omalizumab 300 mg or placebo every 4 weeks for 28 weeks. Angioedema-related QoL, skin-related QoL impairment, and psychological well-being were assessed. Results Ninety-one patients were randomized and 68 (omalizumab, n=35; placebo, n=33) completed the 28-week treatment period. At baselin…

Histamine and spontaneously released mast cell granules affect the cell growth of human hepatocellular carcinoma cells

2007

The role of mast cells in tumor growth is still controversial. In this study we analyzed the effects of both histamine and pre-formed mediators spontaneously released by mast cells on the growth of two human hepatocellular carcinoma cell lines, HA22T/VGH and HuH-6, with different characteristics of differentiation, biological behavior and genetic defects. We showed that total mast cell releasate, exocytosed granules (granule remnants) and histamine reduced cell viability and proliferation in HuH-6 cells. In contrast, in HA22T/VGH cells granule remnants and histamine induced a weak but significant increase in cell growth. We showed that both cell lines expressed histamine receptors H(1) and …

Perioperative nonspecific histamine release : a new classification by aetiological mechanisms and evaluation of their clinical relevance

1993

As a consequence of the performance of a randomized controlled clinical trial on perioperative histamine release and cardiovascular and respiratory disturbances, several types of increases in plasma histamine had to be distinguished instead of only two which existed at the beginning of the study: drug-induced allergic and pseudoallergic reactions. First of all, the new classification by aetiology (clinical epidemiology) was derived from a meta-analysis (secondary analysis) of the most recent literature. According to that histamine release in the perioperative period has several, different causes and is involved in several, different disease manifestations. A clear distinction (classificatio…

Histamine inhibits 5-hydroxytryptamine release from the porcine small intestine: Involvement of H3 receptors

1992

Abstract Strips of the porcine small intestine were incubated in vitro, and the release of 5-hydroxytryptamine (5-HT) was determined by high-pressure liquid chromatography with electrochemical detection. Removal of the mucosa resulted in a large reduction (95%) of tissue 5-HT, suggesting that enterochromaffin cells are the main source of 5-HT. The release of 5-HT was reduced by 70% after omission of calcium. Tetrodotoxin and hexamethonium reduced the release of 5-HT by 30%–40% in a nonadditive manner, indicating a spontaneous neuronal (nicotinic) excitatory input to the enterochromaffin cells. Histamine inhibited the release of 5-HT by about 50%. This effect was not affected by mepyramine o…

Efficacy of leukotriene receptor antagonist in chronic urticaria. A double-blind, placebo-controlled comparison of treatment with montelukast and cet…

2001

Background The cause and pathogenesis of chronic urticaria are still poorly understood. IgE-independent reactions, are common in adult patients with chronic urticaria, who have daily spontaneous occurrence of weals. H1-receptor antagonists (antihistamines) are the major class of therapeutic agents used in the management of urticaria and angioedema. Nevertheless, chronic urticaria is often difficult to treat and may not be controlled by antihistamines alone. It has been postulated that mediators other than histamine, such as kinins, prostaglandin and leukotrienes, may be responsible for some of the symptoms in urticaria which are not controlled by antihistamines. In this study, which was ran…

Antihistaminic and anticholinergic activities of mequitazine in comparison with clemizole

1988

Abstract The antihistamine and anticholinergic properties of mequitazine have been investigated and compared with those of clemizole. Both mequitazine and clemizole antagonized the effect of histamine in guinea-pig ileum competitively, the pA2 values calculated by Schild plot were 9.95 ± 0.44 for mequitazine and 10.54 ± 0.44 for clemizole. Mequitazine at 10−7 M produced a parallel shift of the dose-response curve to acetylcholine in the rat duodenum, clemizole and the lower doses of mequitazine failed to modify the effect of acetylcholine. The potency of mequitazine and clemizole as H1-histamine blockers is similar, but only mequitazine at highest concentration used showed anticholinergic a…

Pharmacological activity of new histamine analogues.

1974

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.

EFFECTS OF PHORBOL 12,13-DIACETATE AND ITS INFLUENCE ON SPASMOGENIC RESPONSES IN NORMAL AND SENSITIZED GUINEA-PIG TRACHEA

1995

Abstract We have studied the effects of phorbol 12,13-diacetate (PDA) and its influence on a variety of spasmogenic responses in trachea isolated in from normal and sensitized guinea-pigs. Tracheal preparations were denuded of epithelium, treated with indomethacin (2·8 μm), and cooled to 20°C. In these experimental conditions, tracheal strips contracted to PDA (0·1 nm-1 μm). Contractions to PDA (1 μm) were greater in sensitized tissues. In normal trachea, contractions to PDA (0·1 μm) were depressed by H-7, 1-(5-isoquinolinyl-sulphonyl)-2-methylpiperazine, (50 μm), amiloride (10 μm), verapamil (10 μm) and Ca2+-free exposure. Similar effects were obtained in sensitized trachea except that PDA…

Loss of striatal histamine H2receptors in Huntington's: Chorea but not in Parkinson's disease: Comparison with animal models

1993

Autoradiographic techniques were used to study the distribution of histamine H2-receptors as labeled with [125I]iodoaminopotentidine in the brains of patients affected by human neurodegenerative pathologies, as compared with control cases. The highest levels of histamine H2 binding sites in control cases were found in the caudate, putamen, and accumbens nuclei. In Huntington's chorea, the levels of histamine H2 receptor binding sites were found to be markedly decreased in virtually all regions examined, particularly in the putamen and globus pallidus lateralis. The loss of binding sites was related to the grade of the disease. Losses were more marked in grade III disease cases. The possible…