Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0016382 (flushing)
 6,387 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Iloprost is an analogue of epoprostenol (prostacyclin; PGI2; a potent but short-lived prostanoid mainly produced in the vascular endothelium) and mimics the pharmacodynamic properties of this compound, namely: inhibition of platelet aggregation, vasodilatation and, as yet ill-defined, cytoprotection. Improved metabolic and, in particular, chemical stability enhance the clinical utility of iloprost. When administered as an intermittent intravenous infusion at less than or equal to 2 ng/kg/min for 2 to 4 weeks, iloprost reduced rest pain and improved ulcer healing in 40 to 60% of patients with critical leg ischaemia, including diabetic patients, and delayed amputation in the majority of responding individuals. Similar benefits have been seen in thromboangiitis obliterans and, in patients with severe Raynaud's phenomenon, shorter courses of therapy reduced the frequency, intensity and duration of ischaemic episodes for at least 6 weeks. The very few comparative trials reported to date (i.e. vs nifedipine in Raynaud's phenomenon; vs low-dose aspirin in thromboangiitis obliterans) have favoured iloprost, but comparisons with more established agents are needed to assess this drug's value in less severe forms of peripheral ischaemia, such as intermittent claudication. At present, iloprost is administered intravenously and this is a limitation to treatment. The potent, rapidly reversible antiplatelet activity of iloprost suits it for use in extracorporeal circulation and for the intraoperative management of heparin-induced platelet activation. Although results in animal models of ischaemic myocardial injury are encouraging, preliminary clinical experience in patients with myocardial ischaemia or infarction has been disappointing. Most patients tolerate iloprost infusion rates of up to 2 ng/kg/min. Headache and flushing are extremely common and are the suggested end-point of dose titration, as higher doses are associated with a significant incidence of gastrointestinal distress and, ultimately, hypotension. Thus, iloprost provides a pharmacotherapeutic option for patients with severe peripheral vascular disease, a condition for which few alternative drug therapies exist. Its potent but short-lived effects make it well-suited to certain therapeutic niches such as the management of intraoperative platelet activation. Prostanoid analogues have far-reaching therapeutic potential and further experience with iloprost will no doubt help to define its clinical applications.
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PMID:Iloprost. A review of its pharmacodynamic and pharmacokinetic properties, and therapeutic potential in peripheral vascular disease, myocardial ischaemia and extracorporeal circulation procedures. 137 60

Des-amino-D-arginine vasopressin (DDAVP) stimulates the release of factor VIII and plasminogen activator from the vascular endothelium. An infusion of exogenous factor VIII given to haemophiliacs causes an increase in platelet activation. This activation does not occur after stimulating a rise in the patient's own factor VIII level caused by DDAVP infusion. We hypothesised therefore that DDAVP could also cause the endothelial release of prostacyclin (PGI2), a potent anti-platelet agent which would counteract the aggregating effect of factor VIII. To examine this possibility we studied the effect of DDAVP on prostacyclin release, as measured by its stable metabolite 6-oxo-PGF1 alpha, in vitro and in vivo. Rabbit aortic rings were incubated with different concentrations of DDAVP using saline as control. The supernatant was assayed for 6-oxo-PGF1 alpha by radioimmunoassay. All concentrations of DDAVP gave a significant release of 6-oxo-PGF1 alpha. Vasopressin was much less potent. When DDAVP was infused into haemophilic patients there was a significant increase in circulating 6-oxo-PGF1 alpha levels immediately after the infusion. The facial flushing observed as a side-effect of DDAVP could therefore be prostacyclin-mediated. We confirmed this by abolishing the DDAVP induced flushing seen in normal subjects by prior treatment with aspirin which inhibits PGI2 formation.
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PMID:DDAVP stimulates prostacyclin production. 680 93

Intravenous infusion of desmopressin (DDAVP, 0.4 micrograms/kg b.w. in 12') causes an increase in the level of extrinsic plasminogen activator, measured in plasma euglobulin fractions with added C1-inactivator on fibrin plates. A poor response or no response at all was elicited in two out of 21 patients with spontaneous thrombosis, 18/38 with hyperlipoproteinaemia and 10/14 with terminal renal insufficiency requiring haemodialysis. Haemodilution during the first 30' after starting the DDAVP-infusion occurred both in responders and in non-responders; so did haemodynamic reactions: increase in heart rate, drop in diastolic blood pressure, facial flushing. The rise of fibrinolytic activity was shown not to be associated with decreased hepatic blood flow. Normal factor VIII-rises in "non-responders" indicate the responsiveness of the receptive organs, including the hypothalamus, to DDAVP. Despite a normal baseline level of fibrinolytic activity in the blood, as occurs for instance in terminal renal insufficiency, the vascular endothelium may be refractory to stimulation. In some patients especially in type IV hyperlipoproteinaemia, a selective defect of the release of plasminogen activator is postulated. In subjects with low fibrinolytic activity at rest, as observed in spontaneous thromboembolism and in hypertriglyceridaemia, the failure to release plasminogen activator upon stimulation with DDAVP might be a consequence of an impairment of synthesis as well.
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PMID:The use of desmopressin acetate (DDAVP) as a test of the fibrinolytic capacity of patients--analysis of responders and non-responders. 681 44

To study facial flush after systemic administration of human corticotropin-releasing hormone (hCRH) we injected 100 micrograms hCRH intravenously to ten healthy young men. The increase in facial temperature was measured by infrared camera. A significant increase in facial temperature of 1.39 degrees C +/- 0.3 was found within 7 min in all patients, which lasted up to 60 min, although facial flushing was visible in only 50% (5/10) of the probands. In a second experiment 100 micrograms hCRH was then administered to seven other healthy young men. Intra- and extracerebral blood flow velocity changes in the medial cerebral artery (MCA) and external carotid artery (ECA) were measured after hCRH administration by use of Doppler sonography. We found a decrease of intracerebral blood flow which was caused by hyperventilation and was reversible following 6% CO2 hyperventilation during a second injection of 100 micrograms hCRH. Blood flow velocity in the ECA increased by 111.5 +/- 32.9% (compared to baseline level), lasted up to 60 min after hCRH injection, and was not reversible by 6% end-tidal CO2 ventilation. We thus demonstrated that the direct vasodilatory effect of hCRH involves the ECA-supplied vascular territory only. The intracerebral vasoconstrictory effect represents the result of hyperventilation following hCRH injection. The data thus clearly suggest an interaction of hCRH and the vascular endothelium of the ECA, causing a marked blood flow velocity increase and facial flushing.
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PMID:Intra- and extracerebral blood flow changes and flushing after intravenous injection of human corticotropin-releasing hormone. 808 64

Primary Raynaud's phenomenon is common, particularly in younger women, and may be familial. Vasospasm is not confined to the digits and may involve, for example, the tongue and nose, and also visceral organs like the heart, oesophagus or lung and cerebral circulation. Symptoms tend to be milder in primary compared with secondary Raynaud's phenomenon, which is associated with other disorders such as the connective tissue diseases. Indeed, the severity of symptoms often acts as the predictor for the much later onset of the associated systemic disease. Occupational Raynaud's phenomenon is related to the use of vibrating instruments, and a significant proportion of patients may be cured by an early change in job. In those over 60 years of age, Raynaud's phenomenon is commonly a result of atherosclerotic obstructive arterial disease, and screening for and treatment of the risk factors is appropriate. The best-studied mechanisms in Raynaud's phenomenon involve the blood and vascular endothelium. Microcirculatory flow may be impeded by activated platelet clumps, rigid red and white blood cells and damaged endothelium. These platelet clumps, white blood cells and damaged endothelium also release vasoactive/vasoconstrictive compounds which may additionally trigger the clotting cascade and thrombosis. Initial management for mild disease should focus on support and advice regarding avoidance of known precipitating factors, including vasospastic drugs. Cold protection with warming agents, 'Abel' shoes and also electrically heated gloves and socks is effective, but may be too cumbersome and inconvenient for some patients. Simple vasodilators like naftidrofuryl, inositol nicotinate and possibly pentoxifylline (oxpentifylline) are useful in mild disease, with adverse effects like headache and flushing being less problematic. The 'gold standard' of Raynaud's phenomenon treatment is nifedipine, a calcium channel antagonist/blocker. Full dosage, however, can be limited by ankle swelling, headache and flushing, but adverse effects may be reduced by using the 'retard' or long-acting preparations. Adverse effects are also reduced with the newer calcium channel antagonists like diltiazem but at the expense of efficacy. Useful, enhanced benefit is also achieved by combination therapy with vasodilators. Newer treatments include the prostaglandin analogues which are effective but disadvantaged by their parenteral route of administration, and lack of licence in some countries. Oral preparations are, however, being studied and are in the pipeline. Essential fatty acid supplementation is mildly effective, while ketanserin and calcitonin gene-related peptide both look promising. Lumbar sympathectomy retains its important role in the treatment of Raynaud's phenomenon involving the lower limbs. Satisfactory symptomatic relief is now possible for many patients with Raynaud's phenomenon and this should certainly be the aim for all patients seeking medical help.
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PMID:Pharmacotherapy of Raynaud's phenomenon. 911 18

The objective of this study was to gain deeper insight into the early reasons for saphenous vein graft disease and to find a practical approach to obviate it. Intraoperative storage of freshly explanted venous grafts (45 min, 20 degrees C; n=25 in each case) in saline, saline + 5% albumin, or HTK-solution and also in heparinized autologous blood was poorly tolerated by the endothelium. Large endothelial areas (mostly >75% of total surface) were detached already during brief non-pulsatile flushing just before the transplantation. Contact of deendothelialized areas in graft remnants with defined mixtures of coagulation factors or blood (n=11-17) caused rapid coagulatory processes via expression of tissue factor and assembly of prothrombinase in the subendothelium. Attached platelets and leukocytes accelerated the procoagulatory processes further, and endothelium-dependent anticoagulatory activities were significantly abolished. During pulsatile arterial flow, the resulting blood clots exacerbated the damage of the intima markedly, because they were flushed away tearing off further endothelium. In contrast, storage of venous grafts in a plasma preparation freed from isoagglutinins and coagulation factors preserved the endothelium, which resisted arterial flow and revealed anticoagulatory activity in the presence of antithrombin III and/or protein C. We conclude that gentle preparation and preservation of the vascular endothelium with a suitable storage solution during bypass surgery is a decisive first step to obviate saphenous vein graft disease.
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PMID:Extensive deendothelialization and thrombogenicity in routinely prepared vein grafts for coronary bypass operations: facts and remedy. 1968 84

Introduction. Posterior Reversible Encephalopathy Syndrome (PRES) is an increasingly recognized clinical and radiological entity with a wide spectrum of symptoms. Its mechanism depends on failure of the blood-brain barrier due to high systemic blood pressure (BP) and loss of integrity of vascular endothelium related with different triggers. Methods. We aim to report a case of PRES induced by arterial hypertension and very early systemic sclerosis (SSc) not previously known. Results. A 64-year-old female was admitted due to 1-week pulsating headache more prominent on frontal scalp, accompanied by phonophobia, photophobia, and facial flushing. Neurological exam revealed brisk deep tendon reflex. Brain magnetic resonance imaging (MRI) showed subcortical lesions mainly located in posterior regions. BP was monitored and episodic arterial hypertension was detected. In laboratory tests positive anti-topoisomerase I antibodies were detected. BP was controlled with angiotensin-converting-enzyme inhibitors and headache improved. In a new MRI a month later improvement of white matter lesions was observed. Capillaroscopy showed "active pattern," considered typical of SSc. Conclusion. In SSc anti-endothelial cell antibodies impair vascular endothelium and liberation of vasoconstrictors leads to BP increasing and disruption of blood-brain barrier autoregulation mechanisms. PRES can be the first manifestation of very early SSc and this entity should be considered even in absence of skin lesions or Raynaud phenomenon.
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PMID:Posterior reversible encephalopathy syndrome as presenting form of very early systemic sclerosis. 2580 77