Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0022116 (ischemia)
 91,303 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The American College of Cardiology/American Heart Association Task Force on Practice Guidelines has published recommendations on the diagnosis and treatment of patients with known or suspected unstable angina and non-ST-segment elevation myocardial infarction. The acute ischemia pathway presented in these guidelines encompasses both an early invasive strategy and an early conservative strategy. There are now 4 randomized, controlled trials that have compared the routine early invasive strategy with the selective-invasive or ischemia-guided strategy (Thrombolysis in Myocardial Infarction [TIMI] IIIB, Veterans Affairs Non-Q-Wave Infarction Strategies in Hospital [VANQWISH], Fragmin and Fast Revascularization During Instability in Coronary Artery Disease [FRISC] II, and Treat Angina with Aggrastat and Determine Cost of Therapy with an Invasive or Conservative Strategy [TACTICS]-TIMI 18). The most relevant of these studies to current clinical practice are the FRISC II and TACTICS-TIMI 18 studies. The data from these studies indicate that ST-segment depression or elevated levels of troponin or the MB isoenzyme of creatinine kinase are markers of increased risk and that such patients would benefit from early revascularization. However, the data further suggest that aggressive antiplatelet, antithrombin, and anti-ischemic therapies are also important. Although FRISC II and TACTICS-TIMI 18 support an early invasive approach in most patients (ie, intermediate- and high-risk patients) with non-ST-segment elevation acute coronary syndromes (ACS), all 4 trials support a more conservative approach in those without electrocardiographic changes or enzyme elevations, notably the use of intensive antiplatelet, antithrombotic, and anti-ischemic therapy combined with careful clinical assessment and provocative testing. Patients then undergo catheterization and revascularization only if spontaneous angina occurs or if there is electrocardiographic, enzymatic, or other objective evidence of stress-induced myocardial ischemia. We conclude that tailoring the early initial therapy in hospital to the level of risk is essential to optimizing efficacy and clinical outcomes in this challenging, but common group of ACS patients.
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PMID:Interpreting new treatment guidelines for non-ST-segment elevation acute coronary syndromes. 1169 15

The present study investigates the association between increases in the concentration and function of plasma fibrinogen in two groups of patients with chronic ischemic heart disease (11 with recurrent ischemic events and 19 free of these episodes) and in 34 healthy controls. The fibrinogen function index (fibrinogen function per unit of fibrinogen protein) (FgFI) was used as a measure of the fibrinogen clotting potential. The prothrombin fragment 1+2 (F1+2) and thrombin-antithrombin (TAT) were used as procoagulant markers. Plasma sialic acid (SA) was also evaluated as an inflammatory marker. No differences were found between FgFI (1.06+/-0.13 vs. 1.02+/-0.13), F1+2 (1.2+/-0.5 vs. 1.1+/-0.4 nmol/l) and TAT (2.5+/-1.3 vs. 2.5+/-0.7 microg/ml) in postinfarction patients without recurrent coronary ischemic events and the control group. However, postinfarction patients who suffered recurrent coronary ischemic events had significantly higher FgFI than patients without these symptoms (1.19+/-0.09 vs. 1.06+/-0.13), P<.01) and than the control group (1.19+/-0.09 vs. 1.02+/-0.13, P<.001). Moreover, the F1+2 (1.4+/-0.5 vs. 1.1+/-0.4 nmol/l, P<.05) and TAT (3.6+/-3.3 vs. 2.5+/-0.7 microg/ml, P<.05) were significantly higher in patients who suffered recurrent coronary ischemic events than in the control group. However, F1+2 and TAT were not different between patients with and without these symptoms. The fibrinogen protein (Fg-protein) concentration and high molecular weight fibrinogen (HMW-Fg) levels were significantly higher in both postinfarction patient groups than in the control group and in postinfarction patients with recurrent coronary ischemic events than in postinfarction patients without these symptoms. The plasma SA levels were significantly increased in postinfarction patients with and without recurrent coronary ischemia as compared with the control group. A positive correlation was found between fibrinogen and SA levels (r=.5, P<.01). In conclusion, our study indicates that the procoagulant factors, among which we include fibrinogen, F1+2 and TAT play a very active role in recurrent ischemic events in postmyocardial infarction patients. High plasma concentrations of both fibrinogen and SA suggests that fibrinogen becomes elevated as a consequence of inflammatory processes. The FgFI as an indicator of clotting potential of fibrinogen appears to be associated with ischemic events in chronic coronary artery disease.
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PMID:Relationship between fibrinogen protein and fibrinogen function in postmyocardial infarction patients. 1175 51

Evidence shows that leukocyte recruitment into inflamed liver sinusoids does not require selectins, with one notable exception: ischemia-reperfusion (I/R). We used intravital microscopy to directly visualize the liver microcirculation during I/R and localized endotoxemia (liver superfused with lipopolysaccharide). General anti-selectin therapy (fucoidan) or anti-adhesion therapy with an antithrombin inhibitor (hirudin) was also used. Many neutrophils rolled and adhered in postsinusoidal vessels and sequestered in the sinusoids during I/R and local endotoxin superfusion. Although fucoidan blocked rolling in both forms of inflammation, leukocyte recruitment into sinusoids was only blocked in I/R. Adhesion was also inhibited in postischemic sinusoids with a second anti-adhesive agent (hirudin). Because liver I/R inevitably induces ischemia upstream in the intestine, anti-selectin therapy may prevent intestinal injury, which could prevent downstream liver inflammation. To test this hypothesis, we completely removed the intestine and rerouted blood flow from the superior mesenteric artery to the superior mesenteric vein. I/R was induced in the liver microcirculation, and many leukocytes rolled and adhered in postsinusoidal venules and adhered in sinusoids. Although fucoidan significantly reduced the rolling in postsinusoidal vessels, adhesion persisted in the sinusoids. Our data suggest that anti-adhesion therapy is effective in liver I/R in the sinusoids and postsinusoidal venules, perhaps in part due to its beneficial effect on the intestine.
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PMID:Molecular mechanisms of leukocyte recruitment in postischemic liver microcirculation. 1206 1

The acute coronary syndromes (ACS) have in common rupture of a vulnerable plaque, leading to exposure of the subendothelial surface and plaque core. The resultant thrombosis leads to a variable degree of flow occlusion, the extent of which differentiates the three syndromes and their treatment by percutaneous coronary intervention (PCI). The guiding principle in the decision when to use PCI in the ACS is that the more time critical and high risk the clinical situation, the more likely it is that PCI will improve ultimate outcome. The use of risk stratification by clinical variables can lead to better triage of patients with non-ST-elevation myocardial infarction (MI) and unstable angina between PCI and medical management. Patients presenting with symptoms suggestive of prolonged ischemia should have an electrocardiogram searching for ST changes, a targeted physical, and blood drawn for rapid assay of cardiac enzymes. In the event that ST elevations suggest infarction, while medical therapy is initiated, emergency cardiac catheterization can be organized. PCI in ACS requires adjunctive antiplatelet and antithrombin therapy, and, in general, coronary stenting is advisable. Among patients with non-ST-elevation MI or unstable angina who can be medically stabilized, the presence of high clinical risk scores would favor early coronary angiography. In their absence, medical therapy can be pursued, unless recurrent ischemia occurs. When the patient's condition is stable, evaluation by stress testing can be used to guide further decisions.
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PMID:Interventional therapy of the acute coronary syndromes. 1207 19

The cardiac troponins have expanded the spectrum of detectable myocardial injury and enhanced the clinician's ability to identify patients with acute coronary syndromes who are at higher risk for death or recurrent ischemic events. Based on available data, it appears most likely that any reliably detected troponin elevation results from myocyte necrosis. This notion has served as the basis for the recent revision of diagnostic criteria for acute myocardial infarction based on cardiac troponin. Nevertheless, further research is necessary to conclusively refute the possibility that the release of cardiac troponins may also occur in the setting of reversible myocyte injury resulting from cellular ischemia. Such an investigation establishing biologic correlates of troponin elevation is likely to prove valuable in guiding diagnostic terminology as well as in therapy. For example, clinical research finding cardiac troponin elevation to be predictive of intracoronary thrombus and distal microvascular obstruction has been important to the evaluation of troponins for targeting powerful antiplatelet and antithrombin therapies. Whether related to irreversible or reversible injury, the cardiac troponins have blurred the traditional boundaries between unstable angina and myocardial infarction and have evolved as powerful tools for risk stratification and therapeutic decision-making.
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PMID:Troponins in patients with acute coronary syndromes: biologic, diagnostic, and therapeutic implications. 1221 81

Is a "routine invasive" or "selective invasive" strategy the best approach for patients with non-ST-segment elevation acute coronary syndrome (ACS)? A "selective invasive" strategy incorporates ischemia-guided use of aggressive medical therapy followed by angiography and revascularization for angina or stress-induced myocardial ischemia. The "routine invasive" strategy (cardiac catheterization followed by percutaneous coronary intervention within 24 to 48 h of symptom-onset) is frequently employed, but no randomized, controlled trials have demonstrated improved clinical outcomes. Recently, the second Fragmin and fast Revascularization during InStability in Coronary artery disease (FRISC-II) and the Treat angina with Aggrastat and determine Cost of Therapy with an Invasive or Conservative Strategy-Thrombolysis in Myocardial Infarction (TACTICS TIMI-18) trials found significant reductions in death, recurrent myocardial infarction, or hospitalization for biomarker-positive ACS. Also, the third Randomized Intervention Trial of unstable Angina (RITA-3) recently reported a halving of refractory angina and reduction in the use of antianginal medication with early intervention. Early trials failed to demonstrate the superiority of the "routine invasive" approach, presumably because of fewer revascularizations, unavailability of stents, and more recent use of glycoprotein IIb/IIIa inhibitors and low-molecular-weight heparins. The FRISC-II, TACTICS TIMI-18, and RITA-3 studies indicate that higher-risk patients benefit from early revascularization, but that aggressive antiplatelet, antithrombin, and anti-ischemic therapy are also important. While all three trials support an "early invasive" approach in intermediate- and high-risk patients, other trials support a more "conservative" approach in those without electrocardiographic changes or enzyme elevations. Optimal management should incorporate both strategies.
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PMID:"Routine invasive" versus "selective invasive" approaches to non-ST-segment elevation acute coronary syndromes management in the post-stent/platelet inhibition era. 1264 49

The therapeutic potential of low-molecular-weight (LMW) fucoidan, a sulfated polysaccharide extracted from brown seaweed devoid of direct antithrombin effect, was investigated in vitro and in a model of critical hindlimb ischemia in rat. In vitro results showed that LMW fucoidan enhanced fibroblast growth factor (FGF)-2-induced [(3)H]thymidine incorporation in cultured rat smooth muscle cells. Intravenous injection in rats of LMW fucoidan significantly increased the stromal-derived factor (SDF)-1 level from 1.2 +/- 0.1 to 6.5 +/- 0.35 ng/ml in plasma. The therapeutic effect of LMW fucoidan (5 mg/kg/day), FGF-2 (1 micro g/kg/day), and LMW fucoidan combined with FGF-2 was assessed 14 days after induction of ischemia by 1) clinical evaluation of claudication, 2) tissue blood flow analysis, 3) histoenzymology of muscle metabolic activity, and 4) quantification of capillary density. Both LMW fucoidan and FGF-2 similarly improved residual muscle blood flow (62.5 +/- 6.5 and 64.5 +/- 4.5%, respectively) compared with the control group (42 +/- 3.5%, p < 0.0001). The combination of FGF-2 and LMW fucoidan showed further significant improvement in tissue blood flow (90.5 +/- 3%, p < 0.0001). These results were confirmed by phosphorylase activity, showing muscle regeneration in rats treated with the combination of FGF-2 and LMW fucoidan. Capillary density count increased from 9.6 +/- 0.7 capillaries/muscle section in untreated ischemic controls to 14.3 +/- 0.9 with LMW fucoidan, 14.5 +/- 0.9 with FGF-2, and 19.1 +/- 0.9 in combination (p < 0.001). Thus, LMW fucoidan potentiates FGF-2 activity, mobilizes SDF-1, and facilitates angiogenesis in a rat model. This natural compound could be of interest as an alternative for conventional treatment in critical ischemia.
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PMID:Low-molecular-weight fucoidan promotes therapeutic revascularization in a rat model of critical hindlimb ischemia. 1264 49

Necrosis of the digits is a rare complication of warfarin therapy of obscure pathogenesis. We report a 61-year-old woman with a 12-month history of Raynaud's phenomenon who developed multiple digital necrosis following aortic valve replacement with mechanical prosthesis for aortic insufficiency caused by nonbacterial thrombotic endocarditis. Exacerbation of Raynaud's phenomenon occurred during the postoperative period, with daily episodes of ischemia of the fingers and toes that improved with local warming. However, coincident with the occurrence of immune heparin-induced thrombocytopenia, and while undergoing routine warfarin anticoagulation because of the mechanical valve prosthesis, the patient abruptly developed progression of digital ischemia to multiple digital necrosis on postoperative day 8, at the time the international normalized ratio reached its peak value of 4.3. All limb pulses were readily palpable, and vascular imaging studies showed thrombosis only in the superficial femoral and popliteal veins of the right leg. Coagulation studies showed greatly elevated levels of thrombin-antithrombin complexes and prothrombin fragment F1.2 levels, consistent with uncontrolled thrombin generation. After vitamin K administration, no abnormalities of the protein C anticoagulant pathway were identified, consistent with previous studies of other patients with warfarin-induced necrosis complicating heparin-induced thrombocytopenia. Subsequently, the patient was shown to have metastatic breast adenocarcinoma, which explained the patient's initial presentation with nonbacterial thrombotic endocarditis. This patient case suggests that multiple digital gangrene can result from the interaction of various localizing and systemic factors, including compromised microvascular blood flow (Raynaud's phenomenon), increased thrombin generation (heparin-induced thrombocytopenia, adenocarcinoma), and warfarin-induced failure of the protein C natural anticoagulant pathway.
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PMID:Warfarin-associated multiple digital necrosis complicating heparin-induced thrombocytopenia and Raynaud's phenomenon after aortic valve replacement for adenocarcinoma-associated thrombotic endocarditis. 1469 34

The last few years have clarified the tight link between inflammation and coagulation. In addition to the identification of new regulatory mechanisms of the coagulation system and of an explosive number of mediators of inflammation, it is now clear that the existence of a positive feed-back between inflammation and coagulation leads to reciprocal activation of both pathways. Plasma levels of acute phase proteins involved in coagulation and fibrinolysis are elevated during inflammation, while natural anticoagulant mechanisms are depressed. Pro-inflammatory cytokines "activate" cell membranes exposed to flowing blood (endothelium, platelets, monocytes, neutrophils) which from physiologically inert or anticoagulant become procoagulant. Increased tissue factor expression results in increased thrombin formation within the microcirculation. Thrombin is central to fibrin deposition but it also plays a key role in cell-mediated mechanisms involving inflammation, cell proliferation and activation of the natural anticoagulant protein C. Depression of natural anticoagulant mechanisms, occurring in severe sepsis, results in uncontrolled thrombin formation, with pro-inflammatory activity prevailing, and the feed-back loop of inflammation and coagulation ultimately leading to multi-organ failure. However, both in the clinical setting and in animal experiments, heparin or direct anticoagulants have shown no effect on survival even if blocking fibrin deposition. Organ failure is only partially due to the thrombotic occlusion of the microcirculation, while other mechanisms of endothelial damage are probably more relevant in the development of ischemia. The endothelium is central to the maintenance of the natural anticoagulant mechanisms (TFPI, antithrombin, protein C). The protein C system, in addition to dumping thrombin formation, specifically modulates inflammation by cell signaling. This system is markedly depressed in severe sepsis. The infusion of activated protein C, or restoring normal levels of protein C within the circulation - depending on the individual bleeding risk are powerful tools to treat the endothelitis responsible for the clinical sequelae of severe sepsis.
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PMID:[Protein C and coagulation in sepsis]. 1518 14

In France, the incidence of meningococcal infections is increasing and the most severe presentation, called purpura fulminans, has still a death rate of 20-25%. Diagnosis of invasive meningococcal infection must be evoked in any child presenting with febrile purpura (vasculitic rash not disappearing with "tumbler test"); a fulminating form must be suspected in the presence of only one ecchymosis and signs of infection, remembering that recognition of shock is difficult in children. The Health Authority recommend to administer a third generation cephalosporin promptly for any child with signs of infection and an ecchymotic purpura (>3 mm of diameter), and then to refer the patient to the hospital. Children with purpura fulminans should be referred to a paediatric intensive care unit. Management includes antibiotics, steroids, fluid resuscitation and catecholamines (be aware of hypoglycaemia, particularly in infants, and hypocalcaemia). Treatment of cutaneous necrosis and distal ischemia is difficult and still controversial: antithrombin, protein C, tissue plasminogen activator and vasodilator infusion have no proved efficacy. Cases must be rapidly notified to the Public Health Service who will institute chemoprophylaxis for close contacts. Given the predominance of serogroup B in France, we hope that an efficient vaccine will soon become available.
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PMID:[Meningococcal purpura fulminans in children]. 1529 72


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