1THE PARTIAL THROMBOPLASTIN TIME test was originally developed by Langdell et al. (1) as a method of following the therapy of hemophulic patients. These investigators found this test to be extremely sensitive to changes in Factor VIII brought about by whole blood or plasma transfusions. Extensive studies of the partial thromboplastin time test (PTT) by Rodman et il. (2) have shown that this tes...

KEY CLINICAL MESSAGE Acquired hemophilia A should be taken into account in the differential diagnosis of perioperative bleeding in patients without any apparent reason for activated partial thromboplastin time prolongation.

UNLABELLED The activated partial thromboplastin time (aPTT) and anti-Xa activity are used for monitoring unfractionated heparin (UFH) therapy in children and may not be optimal. OBJECTIVE Determine correlations of aPTT, anti-Xa and UFH dose in children. Single centre prospective cohort study in children receiving UFH. The aPTT and anti-Xa results from routine coagulation monitoring were colle...

BACKGROUND An unexpectedly detected prolonged activated partial thromboplastin time (APTT) can be a harmless laboratory finding, but can also reflect a thrombotic tendency or a bleeding disorder. The assistance of laboratory professionals in the interpretation of an unexpectedly detected prolonged APTT (uAPTT) is often required. The way in which uAPTTs are evaluated in laboratories was assessed...

OBJECTIVES To assess the strength of thrombin formation and determine the effects of unfractionated heparin (UFH) in children during cardiac catheterization. BACKGROUND UFH reduces the thrombotic risk related to catheterization but the effects of UFH on the coagulation system in children, and proper monitoring of UFH remain unclear. METHODS We studied 42 patients aged 3-12 years undergoing ...

Although nanotechnology has provided a rich variety of nanomaterials (1-100 nm) for in vivo medical applications, the blood compatibility of all these nanobiomaterials is still largely unexamined. Here, we report the preparation of blood-compatible carbon nanotubes (CNTs) that potentially represent the building blocks for nanodevices having in vivo applications. Activated partial thromboplastin...

Intravenous immunoglobulins cause thromboembolic events at a frequency of 2-3%. Complications of this nature can be life threatening. Nevertheless, a test for thrombogenicity such as non activated partial thromboplastin time is not mandatory for these drugs. As a result of recent incidents we have performed experiments to evaluate a modified thrombin generation test for its ability to detect mi...

A photoelectric clot timer is described. The apparatus allows a large analytic capacity, with good precision and correlation to manual methods, and can be used with capillary blood. Prothrombin analysis according to the method of Quick and Owren, the Thrombotest method, and determinations of partial thromboplastin time are applicable to the apparatus. The semiautomated procedure is extremely si...

The concentration of heparin in plasma was measured using a chromogenic substrate. It appeared that the measurement of heparin concentration in plasma was important in therapeutic control and evaluation of heparin. There was a correlation between the activated partial thromboplastin time (APTT) and heparin concentration in plasma, but since the gradients of regression line differed in each of t...

BACKGROUND Activated partial thromboplastin time (aPTT) and antifactor Xa (anti-Xa) monitoring methods for unfractionated heparin (UFH) often disagree. The extent of discordance for those with elevated bilirubin remains unclear. Our objective was to evaluate concordance between activated aPTT and anti-Xa methods for hyperbilirubinemic patients on UFH. METHODS This was a retrospective cohort s...