ABSTRACT
There are two important reasons why most platelet function studies can be inaccurate. First, platelet function deteriorates when blood is taken out of the vascular tree. Second, tests performed on platelets removed from the blood do not incorporate the role of other cellular and chemical components that may alter platelet activity. This article demonstrates that a coagulation test developed in our laboratory can accurately assess the role of platelet age on the speed of the coagulation of blood. Samples (5.0 mL) of citrated venous blood from 15 volunteers were divided into two groups. One group (n = 6), comprised of subgroups A, B, C, and D of 950 microL aliquots each, was tested within 3 hours. The second group (n = 9), comprised of subgroups E, F, G, and H of 950 microL aliquots each, was tested at 24 hours. The aliquots were added to 50 microL saline without collagen (subgroups A and E), 50 microL saline with 10 micrograms collagen (subgroups B and F), 50 microL saline with 50 micrograms collagen (subgroups C and G), and 50 microL saline with 100 micrograms collagen (subgroups D and H). All collagen-incubated fresh blood samples were significantly more hypercoagulable (shorter recalcification times) compared with the control (no collagen) blood. In the 24-hour-old blood, changes were significant only in the sample with 50 micrograms/mL collagen. We conclude that these data authenticate the role of platelet age in the assessment of the coagulation process.
Subject(s)
Blood Coagulation/physiology , Blood Platelets/physiology , Blood Coagulation Disorders/diagnosis , Citrates , Collagen , Humans , Platelet Function Tests/methods , Sodium Chloride , Time FactorsABSTRACT
Two cases of cardiac tumors were studied by computerized tomography. The first patient presented with cerebral embolization from left atrial tumor. Chest X-ray showed calcification in the region of the atria. A 2-"D" echo showed tumors of the right and left atrium. CT studies with contrast confirmed tumors of right and left atria its relationship with atrial septum and calcification. This is the first case report in the literature of multicentric biatrial tumors thought to be myxomas shown by computerized tomography. The second patient presented with weight loss, progressive weakness, shortness of breath and palpitations. A 2-"D" echo showed a large pedunculated left atrial mass prolapsing across the mitral valve into the left ventricle. CT with contrast showed large mass 3.5 X 4.5 cm in the left atrium. At surgery, this was proved to be a left atrial myxoma.
