Method for the determination of functional (clottable) fibrinogen by the new family of ACL coagulometers.

A new family of coagulometers ACL 100, 200 and 300 (Instrumentation Laboratory, IL) has recently been introduced, in addition to the existing ACL 810. This paper presents a technique to determine clottable fibrinogen using the ACL method based on the measurement of the light scattered from the reaction mixture during a PT test. This technique was found to compare well with the present most commonly used methods.

Intraplatelet serotonin (I5HT) in children with the hemolytic uremic syndrome.

I5HT levels were investigated in 14 children with Hemolytic Uremic Syndrome (HUS). Low levels of I5HT were demonstrated in all the children studied during the early phase of the disease, indicating reversible platelet aggregation and recirculation of degranulated platelets. Three months after the onset of HUS, only 2 children with a pathological picture of cortical necrosis and a mild degree of chronic renal failure had low I5HT levels. On the contrary, normal I5HT levels were present in the other children completely recovered from HUS and with a renal biopsy picture of thrombotic microangiopathy with predominant glomerular involvement. We conclude that normal values of I5HT, after the acute stage of HUS, are a good index of complete recovery from the disease. Further observations are required to assess the prognostic value of low I5HT levels in children with chronic renal failure secondary to HUS.

[Epidemiological evaluation of thromboembolic risk. Critical review of the prospects offered by determination of antithrombin III]. / Valutazione epidemiologica del rischio tromboembolico. Revisione critica delle prospettive offerte dal dosaggio dell'antitrombina III.

Authors review the epidemiology of deep venous thrombosis and the prothrombotic state in high risk patients; particularly antithrombin III role in blood clotting is considered. A fall in antithrombin III concentration and/or activity can induce hypercoagulability and thrombosis. Moreover authors stress the need to evaluate antithrombin III as anti-Xa activity, to detect high risk patients for deep venous thrombosis.

The fibrinolytic system in the newborn: role of histidine-rich glycoprotein.

The fibrinolytic system controls fibrin deposition and its clearance. The efficacy of this system can be evaluated by plasminogen concentration determinations and by the behavior of factors such as histidine-rich glycoprotein (HRG) which controls plasminogen activation and alpha 2-antiplasmin which controls plasmin activity. Circulating plasminogen levels are decreased in the neonatal period. We studied factors affecting fibrinolysis in neonates and observed that an important reduction in HRG accompanied the reduced circulating plasminogen levels, with the result that 85% of circulating plasminogen was not bound to HRG and was thus free for binding to fibrin and for activation to plasmin. This condition is consistent with the increased fibrinolytic activity secondary to the "clotting activation' observed in the neonatal period particularly on the 1st day of life.