Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.4.21.6 (thromboplastin)
 13,278 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The results of a prior clinical report suggested that nitroglycerin may interfere with the anticoagulant effect of heparin. Therefore, 30 adult patients undergoing cardiac surgery were studied in a controlled, prospective fashion. Thirteen patients on chronic nitrate therapy received an intraoperative nitroglycerin infusion at 1 micrograms/kg/min intravenously. Seventeen patients received no preoperative or intraoperative nitrates (control group). Heparin, 300 units/kg, was administered to all patients in three consecutive doses: 40 units/kg, 80 units/kg, and 180 units/kg. The activated coagulation time and activated partial thromboplastin time were measured prior to heparin, and 5 minutes after each heparin dose. There were no differences in automated activated coagulation times or in activated partial thromboplastin times between the groups at any measurement period. The study is limited in that only patients on chronic nitrates were included in the treatment group and that only a modest dose of nitroglycerin was used. However, it is concluded that a modest dose of intravenous nitroglycerin does not interfere with the anticoagulant effect of boluses of beef lung heparin in patients undergoing cardiac surgery.
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PMID:Modest doses of nitroglycerin do not interfere with beef lung heparin anticoagulation in patients taking nitrates. 147 63

There is evidence that intravenous nitrates which are frequently used in acute coronary syndromes may interfere with the anticoagulant effect of heparin. We compared the effect of two different nitrate preparations on the activated partial thromboplastin time (APTT), anti-thrombin III activity (AT III) and plasma heparin levels in patients (n = 50) undergoing routine percutaneous transluminal coronary angioplasty (PTCA) for stable angina. Patients were randomized to either: (1) intravenous heparin and nitroglycerin (GTN); or (2) intravenous heparin and isosorbide dinitrate. The APTT, plasma heparin concentration and AT III activity were measured before PTCA and at 2 and 4 hours after commencement of infusions. Both groups received identical doses of heparin. Group 1 patients received a constant dose of 16.6 micrograms/minute of GTN, and group 2 patients received 33.3 micrograms/minute of isosorbide dinitrate. At 4 hours the median APTT ratio was significantly lower in group 1 compared with group 2 (2.6 versus 4.5) (P < 0.05) as was the plasma heparin concentration (0.18 U/ml versus 0.32 U/ml (P < 0.05). However, no significant difference in APTT ratios or plasma heparin concentrations were noted at any of the other sample times. AT III activity was not significantly different between the groups at any sample time. Within-group analysis showed significantly lower APTT ratio and heparin concentrations at 4 hours compared with the respective 2 hour values. These results would suggest that there is a potential impairment of anticoagulation with low-dose intravenous nitroglycerin and to a lesser extent with low-dose isosorbide dinitrate. Early and frequent monitoring may therefore be appropriate when intravenous nitrates and heparin are used in combination.
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PMID:The effect of different nitrate preparations on plasma heparin concentrations and the activated partial thromboplastin time. 817 Aug 77

Because of the unavoidable occurrence of vessel disruption after successful coronary balloon angioplasty, the reliability of quantitative angiographic analysis in that setting has been questioned. For this reason and the suggested occurrence of delayed elastic recoil, repeat angiography at 24 hours has been advocated in clinical interventional trials. In this study, these issues are confronted by performing comprehensive quantitative analysis (Cardiovascular Angiographic Analysis System) of coronary angiograms, acquired in multiple identical projections immediately after and 24 hours after angioplasty, in 102 patients with 110 successfully dilated lesions. Vasomotion was controlled by intracoronary nitrate before angiography and all patients were fully anticoagulated (activated partial thromboplastin time 85 to 120 seconds) for > 24 hours. Paired Student's t tests applied to angiographic measurements revealed that there was no significant deterioration in minimal luminal diameter or cross-sectional area from immediately after angioplasty to 24 hours later. It can thus be inferred that there is no phenomenon of delayed elastic recoil, at least during this time period. Measurement accuracy and precision of the Cardiovascular Angiographic Analysis System from the postangioplasty angiogram are highly acceptable, at < 0.01 and +/- 0.20 mm, respectively. Therefore, it is concluded that routine repeat 24-hour angiography is not indicated after successful angioplasty. A highly significant increase (p < 0.001) in reference diameter (+0.11 +/- 0.18 mm) was responsible for the apparent increase in percent diameter stenosis (2.4 +/- 7%), a finding that demonstrates the potential for error by selective application of percent diameter stenosis measurements alone. Preferential use of absolute luminal measurements is thus strongly recommended for clinical trials with angiographic monitoring.
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PMID:Usefulness of repeat coronary angiography 24 hours after successful balloon angioplasty to evaluate early luminal deterioration and facilitate quantitative analysis. 825 23

We report a complication observed in a 77-year-old man admitted to another hospital for "de novo" angina, in which coronary angiography showed a proximal 65% stenosis of the left anterior descending artery. The patient was medically stabilized, but one month later he developed unstable angina that was not controlled by heparin, nitrate and calcium antagonist infusions. Therefore, he was started on ReoPro (0.25 mg/kg bolus and 10 micrograms/min infusion) but because of persisting symptoms, he was transferred to our unit for urgent PTCA. Angioplasty plus stenting was successful and angina disappeared. The ReoPro infusion was stopped (6 hours after it had been started) for mild oral bleeding. Blood analysis was normal (including platelet count) except for the activated partial thromboplastin (PTT) and prothrombin (PT) time, which exceeded the laboratory limits of determination. Consequently, heparin infusion was also stopped. Eight hours after PTCA, he suddenly developed hypotension, bradycardia and loss of consciousness. The echocardiogram revealed a large pericardial effusion with diastolic collapse of the right cardiac chambers. The patient was treated with volume expanders, plasma and platelet units in an attempt to reestablish a normal hemodynamic pattern and normal platelet function. Elective pericardiocentesis was performed 24 hour later, with drainage of 800 ml of hematic effusion. Severe hemorrhagic complication was induced by ReoPro despite a normal platelet count. This was successfully counteracted with plasma and platelet infusion.
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PMID:[Cardiac tamponade after coronary angioplasty induced by treatment with ReoPro]. 1032 29

Excessive production of nitric oxide (NO) by the inducible form of NO synthase (iNOS) plays a key role in the development of endotoxin shock. Tumor necrosis factor-alpha (TNF-alpha) induces iNOS, thereby contributing to the development of shock. We recently reported that recombinant tissue factor pathway inhibitor (r-TFPI), an important inhibitor of the extrinsic pathway of the coagulation system, inhibits TNF-alpha production by monocytes. In this study, we investigated whether r-TFPI could ameliorate hypotension by inhibiting excessive production of NO in rats given lipopolysaccharide (LPS). Pretreatment of animals with r-TFPI prevented LPS-induced hypotension. Recombinant TFPI significantly inhibited the increases in both the plasma levels of NO2-/NO3- and lung iNOS activity 3 h after LPS administration. Expression of iNOS mRNA in the lung was also inhibited by intravenous administration of r-TFPI. However, neither DX-9065a, a selective inhibitor of factor Xa, nor an inactive derivative of factor VIIa (DEGR-F.Vlla) that selectively inhibits factor VIIa activity, had any effect on LPS-induced hypotension despite their potent anticoagulant effects. Moreover, neither the plasma levels of NO2-/NO3- nor lung iNOS activity were affected by administration of DX-9065a and DEGR-F.VIIa. These results suggested that r-TFPI ameliorates LPS-induced hypotension by reducing excessive production of NO in rats given LPS and this effect was not attributable to its anticoagulant effects, but to the inhibition of TNF-alpha production.
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PMID:Recombinant tissue factor pathway inhibitor prevents lipopolysaccharide-induced systemic hypotension in rats by inhibiting excessive production of nitric oxide. 1177 29

We examined the blood compatibility and protein adsorption on hydroxyapatite and hydroxy-carbonate apatite. Those apatites were synthesized under a 0, 5, or 15% CO(2)-containing N(2) atmosphere by a wet-chemical method with a strong ammonia alkali solution of calcium nitrate and diammonium hydrogen phosphate (5:3 in molar ratio) and subsequent calcination in the range of 105-700 degrees C. From infrared (IR) analysis, the carbonate ions substituted both phosphate ions and hydroxyl ions in the hydroxyapatite lattice; the intensities of IR bands assignable to phosphate ions and hydroxyl ions were reduced on calcinations. The specific surface areas of synthesized apatites decreased with increasing calcination temperature. Blood-clotting properties were evaluated in terms of active partial thromboplastin time, prothrombin time, and the amount of fibrinogen for the plasma in contact with the apatites, indicating that all the apatites barely influenced the blood clotting system. The apatites were in contact with a solution containing both bovine serum albumin (BSA) and beta(2)-microglobulin (beta(2)-MG), and the amounts of those proteins adsorbed on them were examined: the amount of absorbed BSA and beta(2)-MG gradually increased with the calcination temperature below 500 degrees C, while it showed a sudden increase when more than 600 degrees C. Hydroxy-carbonate apatite synthesized under a 15% CO(2)-containing N(2) atmosphere and calcined below 400 degrees C had the greatest selectivity in adsorbing beta(2)-MG. Thus, a higher selectivity for beta(2)-MG adsorption was empirically correlated to carbonate ions incorporated in the hydroxyapatite lattice.
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PMID:Selective protein adsorption and blood compatibility of hydroxy-carbonate apatites. 1512 1