Harold R. Roberts

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Scientific literature cites a wide range of values for caffeine content in food products. The authors suggest the following standard values for the United States: coffee (5 oz) 85 mg for ground roasted coffee, 60 mg for instant and 3 mg for decaffeinated; tea (5 oz): 30 mg for leaf/bag and 20 mg for instant; colas: 18 mg/6 oz serving; cocoa/hot chocolate: 4(More)
High-dose recombinant factor VIIa has been successfully used as therapy for haemophiliacs with inhibitors. The mechanism by which high-dose factor VIIa supports haemostasis is the subject of some controversy. Postulating a mechanism in which activity is dependent on tissue factor at the site of injury explains the localization of activity but not the(More)
This review examines the evidence that platelets play a major role in localizing and controlling the burst of thrombin generation leading to fibrin clot formation. From the first functional description of platelets, it has been recognized that platelets supply factors that support the activation of prothrombin. Studies have demonstrated that on activation,(More)
Clinical reports suggest that treatment regimens employing both activated prothrombin complex concentrates (aPCCs) and recombinant activated factor VII (rFVIIa) may control the bleeding in patients with haemophilia who fail to respond to either agent alone. We hypothesised that increased concentrations of prothrombin, as may be observed after the infusion(More)
We have developed a cell-based model of thrombin generation using activated monocytes as a source of tissue factor (TF) and platelets serving as a surface for thrombin generation. Monocytes are activated by lipopolysaccharide and express cell-bound TF. To these are added physiologic (plasma) concentrations of all the plasma procoagulants as well as TF(More)
Using a cell-based model system of coagulation, we performed a systematic examination of the effect of varying individual procoagulant proteins (over the range of 0-200% of pooled plasma levels) on the characteristics of thrombin generation. The results revealed a number of features unique to the different coagulation factors, as well as common features(More)
OBJECTIVE To evaluate the pharmacokinetics and pharmacodynamics of recombinant activated factor VII (rFVIIa). METHODS Single-dose pharmacokinetics of three dose levels (17.5, 35, and 70 micrograms/kg) of rFVIIa were investigated in 15 patients with hemophilia with severe factor VIII or factor IX deficiency (with or without inhibitors) while they were in(More)
Recombinant factor VIIa (rFVIIa; NovoSeven(R), Novo Nordisk, Bagsvaerd, Denmark) has been used for many years in the successful management of bleeding episodes in patients with hemophilia and inhibitors. More recently, rFVIIa has also shown considerable success as a hemostatic agent in trauma and surgery patients without pre-existing coagulopathy. Despite(More)
Clinical experience has shown that high doses of recombinant factor VIIa (rFVIIa) may ensure haemostasis in thrombocytopenic patients. We have used a cell-based model system to mimic thrombocytopenia and analyse the effect of rFVIIa. Lowering the platelet density from 200 x 10(9)/l (reflecting normal conditions) to 100, 50, 20 and 10 x 10(9)/l revealed a(More)
The safety and efficacy of recombinant DNA-produced factor VIIa (rFVIIa) was investigated in 15 haemophilic patients in non-bleeding states and during bleeding episodes (mild to moderate joint bleed). Patients with severe haemophilia A without inhibitors (n = 4), haemophilia A with inhibitors (n = 10), and haemophilia B with inhibitor (n = 1) received one(More)