Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0027947 (neutropenia)
 17,527 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The aim of platelet inhibitory therapy in cardiology is to prevent undesired thrombus formation and, thus, to prevent complications of cardiovascular diseases. In Germany, 5 substances are approved for antiplatelet therapy. Acetylsalicylic acid, an inhibitor of platelet cyclooxygenase, has been shown to be effective at both high and low doses in the secondary prevention of myocardial infarction, coronary heart disease, and cerebrovascular disease. In addition, acetylsalicylic acid is effective in reducing the complications of unstable angina pectoris and coronary angioplasty, and in reducing the occlusion rate of aortocoronary bypass grafts. The addition of dipyridamole to acetylsalicylic acid has not been shown to result in any additional benefit in many clinical studies. Ticlopidine, an antagonist of ADP-induced platelet aggregation has been similarly effective as acetylsalicylic acid in the treatment of coronary heart disease. The principal side effect of the drug, the occurrence of neutropenia in about 1% of treated patients, makes regular blood cell counts mandatory during treatment. In the secondary prevention of cerebrovascular disease, the drug may be superior to acetylsalicylic acid. Trapidil is an anti-platelet substance which acts on platelets through various mechanisms including inhibition of the release of "platelet derived growth factor". In 3 smaller randomized studies, trapidil has been found to reduce the restenosis rate after coronary angioplasty. Abciximab, the Fab-fragment of an antibody against the platelet fibrinogen receptor glycoprotein 11b/IIIa has been shown to be effective in the prevention of acute and long-term complications of high-risk coronary angioplasty.
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PMID:-New aspects in antithrombotic therapy--platelet inhibitors-. 864 75

The effects of indomethacin, a cyclooxygenase inhibitor, upon plasma concentrations of prostaglandin E2 (PGE2), the febrile response, and metabolic and hematological alterations induced by lipopolysaccharide (LPS) were studied. Experimental endotoxemia was provoked via i.p. injection of 1.0 mg E coli LPS/kg in rats (group A). Indomethacin was introduced/os (2.5 mg/kg) 30 min prior to LPS challenge (group B). Pretreatment with this medication completely inhibited the hyperthermic response to LPS and eliminated the LPS-induced non-specific symptoms of anorexia, adipsia, reduced locomotory activity and gastrointestinal troubles. Plasma PGE2 concentrations increased as early as the 2nd h after the LPS challenge but were blocked when endotoxin application was preceded by indomethacin treatment. Indomethacin did not significantly influence hematological parameters. The dynamics of hematocrit and erythrocyte counts were similar in both groups with a decrease up to the 2nd h followed by an increase to maximum at post-treatment day 3. Pretreatment with indomethacin did not influence the endotoxin-induced leukopenia observed at the 2nd h or the accompanying neutropenia and left shift. Cyclooxygenase inhibition affected total protein concentrations; they were decreased in the early hours of the study (hours 4-6) in both groups. The later tendency towards increase in total protein concentrations was more expressed in animals from group B. Changes in blood glucose were characterized by a permanent tendency towards decrease after hour 2 of LPS challenge up to day 6 (group A). In group B, a similar tendency was observed, but glucose concentrations decreased between hours 2-6 and then returned to initial values.
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PMID:Effects of indomethacin on lipopolysaccharide-induced plasma PGE2 concentrations and clinical pathological disorders in experimental endotoxemia. 946 1

Aspirin inhibits platelet activation by irreversibly inhibiting platelet cyclooxygenase and thromboxane production, and reduces the odds of serious vascular events (stroke, myocardial infarction or vascular death) by about one quarter in a range of patients with symptomatic atherosclerosis at high risk of a subsequent event. The adenosine diphosphate (ADP) receptor antagonists clopidogrel and ticlopidine are significantly more effective than aspirin in high-risk vascular patients, further reducing the odds of serious vascular events by about 10% (95% CI 2-19%) over the benefit provided by aspirin. The ADP receptor antagonists are also associated with a significant 30% reduction in the odds of gastrointestinal haemorrhage (odds ratio 0.71, 95% CI 0.59-0.86). Ticlopidine increases the odds of skin rash and of diarrhoea by more than twofold compared with aspirin, whereas clopidogrel is associated with a one-third increase in the odds of rash and of diarrhoea. Only ticlopidine increases the odds of neutropenia compared with aspirin. There is no clear evidence as yet for the benefit of dipyridamole or an oral GP IIb/IIIa receptor antagonist as single antiplatelet agents in atherothrombotic patients. Amongst high vascular risk patients, the combination of low-dose aspirin and high-dose dipyridamole is associated with about a 10% (95% CI 0-20%) reduction in the odds of a serious vascular event. Most of this reduction is due to a 23% reduction in non-fatal stroke. The size of this estimate continues to be investigated in an ongoing study of patients with transient ischaemic attack and stroke. The combined use of aspirin and ticlopidine is markedly superior to heparin, warfarin and aspirin for reducing thrombotic complications after coronary artery stenting. Clopidogrel plus aspirin has been shown to be safer than aspirin and ticlopidine in coronary stenting, and is now under long-term evaluation in unstable angina, and other conditions in which patients are at high risk of atherothrombotic events.
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PMID:Current oral antiplatelet agents to prevent atherothrombosis. 1131 17

The cytokine granulocyte colony-stimulating factor (G-CSF) is in broad clinical use to treat neutropenia, and trials on its use in immunosuppressed conditions and infections are ongoing. To apply G-CSF effectively, it is crucial to understand the regulation and distribution of its endogenous formation. Since G-CSF release is mediated, at least in part, by TNF-alpha formation, we investigated whether drugs suppressing TNF-alpha also impair G-CSF production. Surprisingly, G-CSF formation was enhanced in lipopolysaccharide (LPS)-stimulated blood from a pentoxifylline-treated patient. In the presence of dibutyryl-cAMP, forskolin, tolafentrine or 3-isobutyl-1-methylxanthine, LPS-induced G-CSF formation was enhanced in THP-1 cells, primary monocytes and whole blood. Correspondingly,rp-8-bromo-cAMP suppressed LPS-induced G-CSF release. Addition of prostaglandin E(2) enhanced and indomethacin suppressed G-CSF formation. Reporter gene studies showed that dibutyryl-cAMP enhanced LPS-induced G-CSF promoter activity, indicating a transcriptional up-regulation. Furthermore, disruption of a newly identified putative cAMP-responsive element (CRE) in the G-CSF promoter demonstrated the regulatory role for G-CSF gene transcription. In conclusion, endogenous G-CSF formation critically depends on both TNF-alpha and cyclooxygenase products, exerting effects via cAMP and the CRE in the G-CSF promoter. This might have bearing for drug side effects, putative G-CSF mimetics and our understanding of G-CSF immunobiology.
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PMID:Cyclic AMP increases endogenous granulocyte colony-stimulating factor formation in monocytes and THP-1 macrophages despite attenuated TNF-alpha formation. 1288 4

Whether leukocytes exert an influence on vascular function in vivo is not known. Here, genetic and pharmacologic approaches show that the absence of neutrophils leads to acute blood pressure dysregulation. Following neutrophil depletion, systolic blood pressure falls significantly over 3 days (88.0 +/- 3.5 vs 104.0 +/- 2.8 mm Hg, day 3 vs day 0, mean +/- SEM, P < .001), and aortic rings from neutropenic mice do not constrict properly. The constriction defect is corrected using l-nitroarginine-methyl ester (L-NAME) or the specific inducible nitric oxide synthase (iNOS) inhibitor 1400W, while acetylcholine relaxation is normal. iNOS- or IFNgamma-deficient mice are protected from neutropenia-induced hypotension, indicating that iNOS-derived nitric oxide (NO) is responsible and that its induction involves IFNgamma. Oral enrofloxacin partially inhibited hypotension, implicating bacterial products. Roles for cyclooxygenase, complement C5, or endotoxin were excluded, although urinary prostacyclin metabolites were elevated. Neutrophil depletion required complement opsinization, with no evidence for intravascular degranulation. In summary, circulating neutrophils contribute to maintaining physiological tone in the vasculature, at least in part through suppressing early proinflammatory effects of infection. The speed with which hypotension developed provides insight into early changes that occur in the absence of neutrophils and illustrates the importance of constant surveillance of mucosal sites by granulocytes in healthy mice.
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PMID:Circulating neutrophils maintain physiological blood pressure by suppressing bacteria and IFNgamma-dependent iNOS expression in the vasculature of healthy mice. 1846 8


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