Preparation and evaluation of PEG-bound thrombin inhibitors based on 4-amidinophenylalanine.

The dipeptide Mtr-Asp-D-Adf-Pip 10 represents a potent thrombin inhibitor. In comparison to NAPAP, 10 exhibited improved tolerability and a longer half-life in vivo, i.e.

Synthesis and characterisation of novel thrombin inhibitors based on 4-amidinophenylalanine.

Thrombin inhibitors have been thought to play a pivotal role in myocardial infarct and stroke incidences and their aftermath. Quite some time ago potent synthetic thrombin inhibitors became known based on peptide derivatives D-Phe-Pro-Arg and benzamidine. One of them, fairly well characterised was beta-naphthylsulphonylglycyl-D,L-4-amidino-phenylalanylpiperidi de (NAPAP).

Inhibition of in vitro clot growth by r-hirudin is more effective and longer sustained than by an analogous peptide.

The specific thrombin inhibitors r-hirudin and a synthetic peptide (I) D-FPRP(G)4-NGDFEEIPEEYL were compared in in vitro tests. r-hirudin proved to be the superior compound with respect to inhibition of amidolytic small substrate turnover that is catalysed by soluble and immobilised thrombin as well as to inhibition of fibrinogen activation. In an in vitro clot model significantly higher molar concentrations of peptide I are needed to achieve fibrin bound thrombin inhibition equivalent to that of r-hirudin.

[Auxiliary MR spectroscopy of blood plasma in the diagnosis of malignant head and neck tumors].

Magnetic resonance (MR) spectroscopy of an EDTA or citrate plasma sample (also referred to as "Fossel test" after Fossel, who first described it) started out as a promising method for fast and simple diagnosis of malignancies. Although the results of our own studies of the head and neck area confirm this tendency, we believe--and so do meanwhile also other investigators--that the clinical use of this test in its present form is not feasible because of lacking specificity.