A Controlled Trial of Rivaroxaban after Transcatheter Aortic-Valve Replacement.

Background: Whether the direct factor Xa inhibitor rivaroxaban can prevent thromboembolic events after transcatheter aortic-valve replacement (TAVR) is unclear.

Methods: We randomly assigned 1644 patients without an established indication for oral anticoagulation after successful TAVR to receive rivaroxaban at a dose of 10 mg daily (with aspirin at a dose of 75 to 100 mg daily for the first 3 months) (rivaroxaban group) or aspirin at a dose of 75 to 100 mg daily (with clopidogrel at a dose of 75 mg daily for the first 3 months) (antiplatelet group). The primary efficacy outcome was the composite of death or thromboembolic events.

Randomised, multicentre trial of micafungin vs. an institutional standard regimen for salvage treatment of invasive aspergillosis.

Invasive aspergillosis remains associated with significant morbidity and mortality, necessitating new options for salvage therapy. The objective of this study was to evaluate the efficacy and safety of micafungin as salvage monotherapy in patients with invasive aspergillosis. Patients with proven or probable invasive aspergillosis, who were refractory or intolerant to previous systemic antifungal therapy, were randomised 2 : 1 to receive 300 mg day(-1) intravenous micafungin monotherapy or an intravenous control monotherapy [lipid amphotericin B (5 mg kg(-1) day(-1)), voriconazole (8 mg kg(-1) day(-1)) or caspofungin (50 mg day(-1))] for 3-12 weeks.

Absence of an interaction between the synthetic pentasaccharide fondaparinux and oral warfarin.

Aims: To investigate the pharmacokinetic and pharmacodynamic interaction of the antithrombotic pentasaccharide fondaparinux (Org31540/SR90107A), given subcutaneously, and oral warfarin in healthy subjects.

Methods: This study was performed according to a randomised, three-way cross-over, placebo-controlled, double-blind design in 12 healthy male subjects. The treatment consisted of five subcutaneous (s.

Pre-clinical pharmacological profile of the novel glycoconjugate Org 36764 with both factor Xa and thrombin (IIa) inhibitory activities.

Org 36764, is an antithrombin III (AT) and thrombin binding carbohydrate, which accelerates the inactivation of both factor Xa and thrombin by AT. It displays in buffer an anti-Xa and anti-thrombin activity of 415 and 2 U/mg, respectively, compared to 172 and 114 U/mg, respectively, for unfractionated heparin (UFH), Org 36764 does not cross-react with HIT (heparin induced thrombocytopenia) antibodies and is not neutralised by PF4. In experimental models in rats, on a molar basis.

Biochemical and pharmacological properties of SANORG 34006, a potent and long-acting synthetic pentasaccharide.

SANORG 34006 is a new sulfated pentasaccharide obtained by chemical synthesis. It is an analog of the "synthetic pentasaccharide" (SR 90107/ ORG 31540) which represents the antithrombin (AT) binding site of heparin. SANORG 34006 showed a higher affinity to human AT than SR 90107/ORG 31540 (kd = 1.

Experimental study of thrombogenicity and foreign body reaction induced by heparin-coated coronary stents.

Background: Results of recent randomized clinical trials have revealed a significant reduction in angiographic restenosis rate when adjunctive stenting was performed after conventional coronary balloon angioplasty. The thrombogenicity of metal stents, however, remains a concern. In the present study, we compare the thrombogenicity of heparin-coated coronary stents with that of bare metallic coronary stents.

Two new closely related rat models with relevance to arterial thrombosis--efficacies of different antithrombotic drugs.

Two thrombosis models in rats are described in which mixed type thrombi are formed at arterial and venous flow rates. The models, containing a silk thread in the aorta and vena cava, respectively, were characterised for the activity of three platelet inhibitors, three thrombin active site inhibitors and five glycosaminoglycans (GAGs). In the two models a similar highly platelet-dependent thrombus developed both in size and composition during the first 10 min after insertion of the silk thread.

Biochemical and pharmacological properties of SANORG 32701. Comparison with the "synthetic pentasaccharide' (SR 90107/ORG 31540) and standard heparin.

SANORG 32701 is a new sulfated pentasaccharide obtained by total chemical synthesis. It is analogue of the "synthetic pentasaccharide" (SR 90107/ORG 31540), which represents the antithrombin III (AT-III) binding site of heparin. Like SR 90107, it shows high affinity for human AT-III (Kd = 3.

Characterization of ORG 20241, a combined phosphodiesterase IV/III cyclic nucleotide phosphodiesterase inhibitor for asthma.

The pharmacological profile of a novel cyclic nucleotide phosphodiesterase (PDE) inhibitor, Org 20241, has been characterized. The compound selectively inhibits PDE IV (pIC50, 5.2-6.

Synthetic analogues of the antithrombin III-binding pentasaccharide sequence of heparin. Prediction of in vivo residence times.

The synthetic pentasaccharide Org 31540/SR 90107A represents the antithrombin III (ATIII) binding region of heparin and accelerates the ATIII-mediated inhibition of coagulation factor Xa. This compound and 15 structural analogues with ATIII binding constants (Kd) ranging from 2.7 to 2600 nmol/L were compared for their plasma elimination in rats as measured from their factor Xa inhibiting activity.

Feasible synthesis and biological properties of six 'non-glycosamino' glycan analogues of the antithrombin III binding heparin pentasaccharide.

In this paper, we report the synthesis of 'non-glycosamino' glycan analogues 5-10 of the antithrombin III binding pentasaccharide 1. Pentasaccharides 5-10 feature a pseudo-alternating EFGH tetrasaccharide sequence, that is, the disaccharide fragments EF and GH have the same substitution pattern. In the synthetic strategy applied for the synthesis of pentasaccharides 5-10, the properly protected EF disaccharide fragments 19 and 20 are obtained from their GH counterparts 17 and 18 by base-catalyzed epimerization.

Pentasaccharide and Orgaran arrest, whereas heparin delays thrombus formation in a rat arteriovenous shunt.

The mode of action of glycosaminoglycans (GAGs) towards thrombus formation in a rat arteriovenous shunt was studied by simultaneous examination of thrombus weight, platelet consumption and thrombin generation during 45 min of blood circulation. A comparison was made between the effects of heparin, the heparinoid Org 10172 (Orgaran), and the chemically synthesized methoxy derivative of the antithrombin III binding pentasaccharide fragment of heparin (Org 31540). All three compounds inhibited thrombus growth by 30% at a dose of 80 anti-Xa U/kg i.

Human bronchial cyclic nucleotide phosphodiesterase isoenzymes: biochemical and pharmacological analysis using selective inhibitors.

1 The aims of the present study were to characterize the cyclic nucleotide phosphodiesterase (PDE) isoenzyme activities present in human bronchi and to examine the ability of selective isoenzyme inhibitors to relax histamine and methacholine precontracted preparations of human bronchi. 2 Three separations of pooled human bronchial tissue samples were performed. Ion-exchange chromatography showed that the soluble fraction of human bronchial preparations contains PDE I, II, III, IV and V isoenzyme activities.

Low molecular weight proteins as carriers for renal drug targeting: naproxen-lysozyme.

Low molecular weight proteins (LMWPs), such as lysozyme, may be suitable carriers to target drugs to the kidney. In this study the antiinflammatory drug naproxen was covalently bound to lysozyme (1:1). Pharmacokinetics of the conjugate, naproxen-lysozyme (nap-LYSO), were compared to that of an equimolar mixture of uncoupled naproxen with lysozyme in freely moving rats.

IgG- and IgE-mediated histamine release from superfused guinea-pig airway tissues.

Anaphylactic histamine release and the inhibition by the beta-adrenoceptor agonist fenoterol has been investigated using lung and tracheal tissues from two groups of guinea-pigs, differently sensitized to respond with IgG or IgE antibodies, respectively. A superfusion method was introduced and compared with classical batch incubation. The difference between IgG- and IgE-mediated histamine release during superfusion of both tissues was much greater than the difference obtained during batch-incubations.

The presence of five cyclic nucleotide phosphodiesterase isoenzyme activities in bovine tracheal smooth muscle and the functional effects of selective inhibitors.

1. The profile of cyclic nucleotide phosphodiesterase (PDE) isoenzymes and the relaxant effects of isoenzyme selective inhibitors were examined in bovine tracheal smooth muscle. The compounds examined were the non-selective inhibitor 3-isobutyl-1-methylxanthine (IBMX), zaprinast (PDE V selective), milrinone and Org 9935 (4,5-dihydro-6-(5,6-dimethoxy-benzo[b]thien-2-yl)-5-methyl-1 (2H)-pyridazinone; both PDE III selective), rolipram (PDE IV selective) and Org 30029 (N-hydroxy-5,6-dimethoxy-benzo[b]-thiophene-2-carboximidamide HCl a dual PDE III/IV inhibitor).

Role of phosphoinositide metabolism in human bronchial smooth muscle contraction and in functional antagonism by beta-adrenoceptor agonists.

The aim of the present investigation was to study in human bronchial smooth muscle (1) the relationship between methacholine and histamine-induced inositol phosphate (IP) production and contraction, (2) the influence of increasing concentrations of methacholine and histamine on the relaxation (pD2 and Emax) by isoproterenol (functional antagonism), and (3) the relation between IP production by methacholine and histamine and the changes of pD2 and Emax values of isoproterenol-induced relaxation. Methacholine and histamine were full agonists in contracting human bronchial smooth muscle, with pD2 values of 6.01 +/- 0.

Muscarinic receptors in human airway smooth muscle are coupled to phosphoinositide metabolism.

In the present study we investigated whether muscarinic receptors in human airway smooth muscle are coupled to phosphoinositide metabolism as a possible transduction mechanism of contraction. Using isolated bronchial smooth muscle preparations, we found that the muscarinic agonist methacholine caused a time- and concentration-dependent accumulation of inositol phosphates in the presence of lithium, an effect which could be inhibited by atropine. Apart from its physiological significance, this finding may have great relevance for the biochemical investigation of cholinergic hyperresponsiveness in the airways of asthmatic patients.

Role of phosphoinositide metabolism in functional antagonism of airway smooth muscle contraction by beta-adrenoceptor agonists.

Histamine and the muscarinic agonists, methacholine, oxotremorine, and McN-A-343, were used to contract guinea-pig tracheal smooth muscle preparations. Cumulative dose-relaxation curves with isoprenaline were performed subsequently. In addition, the concentration-dependent induction of phosphoinositide metabolism by the contractile agonists was measured in bovine tracheal smooth muscle.

Muscarinic M2 receptors in bovine tracheal smooth muscle: discrepancies between binding and function.

Previous work showing that AF-DX 116, a cardioselective muscarinic antagonist in functional experiments, does not discriminate between muscarinic receptors in bovine cardiac and tracheal membranes has been extended. In addition to AF-DX 116 we used the muscarinic antagonists, atropine, pirenzepine, 4-DAMP methobromide, gallamine, hexahydrosiladifenidol and methoctramine, in radioligand binding experiments on bovine cardiac left ventricular and tracheal smooth muscle membranes. The functional antagonism of the methacholine-induced contraction of bovine tracheal smooth muscle strips was also evaluated.

Depolarization-induced release of [(3)H]histamine by high potassium concentrations, electrical stimulation and veratrine from rat brain slices after incubation with the radiolabelled amine.

Brain slices obtained from neocortex, hypothalamus or hippocampus were incubated with [(3)H]histamine and subsequently superfused and exposed to different depolarizing stimuli, viz. high K(+)-concentrations, electrical field stimulation and veratrine. K(+)-induced release of tritium was completely calcium-dependent and its magnitude depended on the K(+)-concentration, with maximal release being reached at 56 mM K(+).