A new method for the specific assay of prothrombin is described which utilises Taipan snake venom and the chromogenic substrate Tos-Gly-Pro-Arg-pNA (Chromozym TH). The method is sensitive and reproducible and shows good correlation with a conventional specific assay for prothrombin. The reaction is dependent on calcium ions and phospholipid, and is therefore sensitive to the coumarin-induced pr...

medium containing blood. For this reason we preferred to test our strains after growth on blood agar base. Precise details of Severin's chromogenic cephalosporin substrate method were not stated. To the best of our knowledge, antibiotic therapy had not been given to the four patients from whom ,B-lactamase producing strains were isolated. Clearly, the possibility of transfer of plasmids determi...

We present a simple assay to examine effects of compounds on virulence gene expression in the human pathogen Staphylococcus aureus. The assay employs transcriptional reporter strains carrying lacZ fused to central virulence genes. Compounds affecting virulence gene expression and activity of the agr locus are scored based on color change in the presence of a chromogenic beta-galactosidase subst...

The general hypothesis for the biological function of 112W glycoprotein I is that it neutralizes all negatively charged macromolecules that might enter the bloodstream and diminishes unwanted activation of the blood coagulation. In the present study we report that $2-glycoprotein I inhibits the activation of the contact phase system of the intrinsic pathway of blood coagulation. Activation was ...

Using a recently developed chromogenic substrate assay sensitive to 10 pg/ml Escherichia coli endotoxin in plasma, systemic endotoxaemia was found in 52% of 21 episodes of fever in patients with a haematological malignancy who were infected. Endotoxaemia was also found in 27% of 22 episodes of fever of unknown origin. In 45 afebrile patients neither neutropenia nor cytotoxic chemotherapy was a ...

A highly selective, ultrasensitive (visual and instrumental detection limits of 40 nM and 0.1 nM, respectively), environmentally-friendly, simple and rapid colorimetric sensor was developed for the detection of copper(II) in water. This sensor is based on a novel signal-amplification mechanism involving reactive halide species (RHSs) including chlorides or bromides, which accelerate copper Fent...

Using the chromogenic substrate S-2222, we have optimized and automated an amidolytic assay for heparin. The assay is based on the detection of anti-Xa activity generated by heparin in plasma. The method is reproducible (intra- and interassay CVs of 2.4 and 3.3%, respectively) and reliable in antithrombin III-deficient plasma. Results of this assay, obtained for plasma samples from patients and...

A test paper for high-selectivity detecting Hg2+ ions in mixed acetonitrile-watersolutions has been achieved using a bis(ferrocenyl) azine, as chromogenic chemosensormolecule, and a solid cellulose fibre, as a substrate. Depending on the amount of mercuryions in contact with the detecting molecule a spectacular color change in the celluloseindicator is produced, being possible to determine the ...

The presence of DPPII (dipeptidyl peptidase II; E.C. 3.4.14.2) has been demonstrated in various mammalian tissues. However, a profound molecular and catalytic characterization, including substrate selectivity, kinetics and pH-dependence, has not been conducted. In the present study, DPPII was purified from human seminal plasma to apparent homogeneity with a high yield (40%) purification scheme,...