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Biomedical subjects

F Rodeghiero

Publications and source records attributed to F Rodeghiero.

At least 163 records · Page 9Linked to original sources
PubMed1990

Platelet von Willebrand factor assay: results using two methods for platelet lysis.

Two different methods (using Triton X-100 and glycerol) for lysing platelets to measure platelet vWF concentrations were compared directly. The platelet concentration of von Willebrand factor antigen (vWF:Ag) was similar for both methods, whereas ristocetin cofactor activity (Ricof) was higher with Triton than with glycerol. After storing platelet lysates for two months at -80 degrees C vWF:Ag and Ricof concentrations decreased with both methods of lysis. Larger than normal (supranormal) vWF multimeric forms could be visualized in platelet lysates obtained using both methods, with no change of the multimeric pattern during storage. Triton can be recommended as the agent of choice to lyse platelets for measurement of their vWF concentration, but the samples must be assayed within two weeks to avoid decay of Ricof activity.

Blood Platelets↗
PubMed1990

Early deaths and anti-hemorrhagic treatments in acute promyelocytic leukemia. A GIMEMA retrospective study in 268 consecutive patients.

The records of 268 consecutive patients with acute hypergranular promyelocytic leukemia, treated at 29 Italian centers between January 1984 and December 1987, have been reviewed to assess the incidence of early hemorrhagic deaths and the effectiveness of various antihemorrhagic treatments. Three separate groups were considered: 94 patients were treated with heparin, 67 with anti-fibrinolytics (tranexamic acid, epsilon-aminocaproic acid, or aprotinin), and 107 with supportive therapy alone. The overall incidence of early hemorrhagic death (within the first 10 days of treatment) was 9.4%, with no significant differences between the various groups. Similarly, there were no differences in complete remission rates or duration of survival. The consumption of packed red blood cells and platelet concentrates was similar for two of the groups, and there was a significantly greater use of platelet concentrates for heparin-treated patients. High blast cell counts on the day of admission were significantly associated with hemorrhagic death within the first 10 days. These counts, plus high blast cell counts and low platelet counts, were associated with death within 24 hours.

Adolescent↗
PubMed1990

Fibrinopeptide A changes during remission induction treatment with L-asparaginase in acute lymphoblastic leukemia: evidence for activation of blood coagulation.

L-Asparaginase, a widely used antileukemic agent, inhibits liver protein synthesis leading to hypofibrinogenemia and hypoprothrombinemia together with a severe reduction of antithrombin III and protein C. An increased risk of thrombosis has been reported in leukemic patients treated with this agent. We measured fibrinopeptide A (FPA) changes in 14 patients with acute lymphoblastic leukemia during induction remission treatment with a protocol including L-Asparaginase (10,000 U/m2/daily intravenous for 14 days). At diagnosis, 9/14 patients had FPA level above upper limit of normal range (mean = 4.1 ng/ml). After two days of therapy, FPA rose to 5.2 ng/ml and thereafter showed a slight increase throughout. Antithrombin III, protein C and fibrinogen dropped to its nadir on day 6 and 9. However, the ratio FPA/fibrinogen on a molar basis showed a three-fold increase during this days, demonstrating that the thrombin-dependent consumption of fibrinogen was also increased. In conclusion, our data show that activation of blood coagulation occurs in concomitance with the hemostatic derangement caused by L-Asparaginase. Replacement therapy with the recently available antithrombin III concentrates may be worthy of a clinical trial to test its effectiveness in preventing the thrombotic phenomena reported in these patients.

Adolescent↗
PubMed1990

Incidence and risk factors for thrombotic complications in a historical cohort of 100 patients with essential thrombocythemia.

The purpose of this study was to determine which factors were associated with an increased risk of thrombo-hemorrhagic complications in a historical cohort of 100 consecutive and unselected patients with essential thrombocythemia (ET) in whom busulfan treatment was given when platelets were more than 1,000 x 10(9)/L and/or a major thrombotic or hemorrhagic event occurred. The incidence of major hemorrhagic complications was very low (0.33%/person-time at risk [pt-yr]) in comparison with that of thrombotic episodes (6.6%/pt-yr). In an adequate and appropriate control historical group of 200 patients, no severe hemorrhages were recorded and the incidence of thrombotic events was 1.2% pt-yr. Thus, the analysis of risk factors was restricted to this latter group of events. Age, a previous thrombotic event, and long duration of thrombocytosis were identified as major risk factors for thrombosis, while smoking, diabetes mellitus, hyperlipidemia, and hypertension did not influence the rate of thrombotic episodes.

Adolescent↗
PubMed1989

Heterogeneous phenotypes of platelet and plasma von Willebrand factor in obligatory heterozygotes for severe von Willebrand disease.

To characterize the heterogeneity of severe (type III) von Willebrand disease (vWD), plasma and platelet von Willebrand factor antigen (vWF:Ag) and ristocetin cofactor activity (Ricof) were measured in 28 obligatory heterozygotes (ie, parents or children of probands from 15 different kindreds with severe vWD). On the average, heterozygotes had low levels of vWF in both platelets and plasma. There was, however, considerable heterogeneity, with four distinct patterns. Eleven heterozygotes had concordant reduction of vWF:Ag and Ricof in both plasma and platelets; five had low levels of vWF:Ag and Ricof in plasma contrasting with normal levels in platelets; eight had a peculiar pattern, the reverse of the above (ie, low levels in platelets and normal levels in plasma); and in one, both vWF measurements were normal in plasma and platelets. These patterns were genetically determined: they were consistent in four couples of consanguineous heterozygotes and in two couples carrying the same gene deletion. Only the remaining three heterozygotes had no clearly identifiable pattern. Other findings of this study were that although most of the heterozygotes had normal bleeding times, the 7 of 28 who had prolonged bleeding times had concordantly low levels of vWF measurements in both plasma and platelets. In conclusion, this large series of obligatory heterozygotes provides evidence for phenotypic and genotypic heterogeneity of severe vWD.

Bleeding Time↗
PubMed1989

Consistency of responses to repeated DDAVP infusions in patients with von Willebrand's disease and hemophilia A.

The consistency in time of responses to separate desmopressin (DDAVP) infusions in patients with von Willebrand's disease (vWD) and mild or moderate hemophilia A has been the subject of limited investigation. We report here the results of a clinical study undertaken to test the consistency of responses to repeated DDAVP administrations in 22 patients with vWD and 10 with mild or moderate hemophilia A (time interval between first and last infusion ranging from 1 to 77 months; median, 13 months). In patients with vWD, 80% of cases showed a departure of less than 20% from the average VIII:C peak level calculated after the two infusions. A similarly consistent pattern was observed for bleeding times recorded 30 minutes after each infusion. In patients with hemophilia A, some infused on more than two instances, the departure from the average VIII:C peak level was less than 20% in nearly 70% of cases. A good within-family consistency was also demonstrated by analyzing data obtained from seven kindreds with vWD and two with hemophilia A. In conclusion, our study suggests that the pattern of responsiveness observed after a DDAVP test-infusion can be reliably used to decide the future clinical management of the individual patient and that a similar pattern of response is usually observed within the same kindred.

Deamino Arginine Vasopressin↗
PubMed1989

Clinical significance of fibrinopeptide A in acute lymphocytic and non-lymphocytic leukaemia.

Fibrinopeptide A (FPA) was systematically investigated in 74 patients with acute leukaemia at different stages of the disease (50 with non-lymphocytic leukaemia, ANLL; 24 with lymphocytic leukaemia, ALL). At diagnosis, 75% of the cases had high FPA levels (86% in ANLL and 54% in ALL) with significantly higher levels in ANLL than in ALL (13.4 vs 4.4 ng/ml; p less than 0.001). Patients with DIC (20 cases in ANLL and 1 case in ALL) had significantly higher levels (p less than 0.001). FPA levels were neither correlated with fibrinogen or FDP levels nor with blast cell count. During chemotherapy, median FPA did not show significant changes whereas, at the end of therapy, a return toward normality was generally observed both in ALL and ANLL apart from the group of patients with acute promyelocytic leukaemia. Among the 24 patients who entered post-remission follow-up (13 ANLL and 11 ALL), 10 cases out of the 11 relapsing (6/6 with ANLL and 4/5 with ALL) had increased FPA 1 to 2 months before the ascertainment of the relapse. However, 16% and 9% of the samples obtained on different occasions, respectively from ANLL and ALL cases in maintained first remission, showed FPA above the normal limit. This study demonstrates that subclinical activation of blood coagulation, as indicated by high FPA level, is common both in lymphocytic and non-lymphocytic leukemia and suggests that this phenomenon is related to disease activity.

Adolescent↗
PubMed1989

Clinical effectiveness of desmopressin in a case of acquired von Willebrand's syndrome associated with benign monoclonal gammopathy.

A case of acquired von Willebrand's syndrome (avWs) secondary to benign monoclonal gammopathy, is described, in which desmopressin (DDAVP) has proven effective repeatedly in preventing bleeding after tooth extraction. The laboratory pattern was similar to that of congenital type IA von Willebrand's disease. After DDAVP, prolonged bleeding time and factor VIII/von Willebrand factor activities were normalized. The disappearance rate of the elicited activities was similar to that observed in patients with congenital disease. This report adds to the scarce data concerning the haemostatic effectiveness of DDAVP in avWs and suggests that this agent might also be used in controlling or preventing bleeding in patients with the acquired disease, selected on the basis of their biological responsiveness to a test-infusion.

Deamino Arginine Vasopressin↗
PubMed1988

Hyper-responsiveness to DDAVP for patients with type I von Willebrand's disease and normal intra-platelet von Willebrand factor.

Desmopressin (DDAVP) has gained wide acceptance as the drug of first choice in the treatment or prevention of haemorrhages in the majority of patients with von Willebrand's disease (vWd). However, data concerning the clinical effectiveness of DDAVP refer generally to mild vWd, with factor VIII and vW factor levels usually above 20% of normal. In 14 patients with type I vWd characterized by very low plasma levels of factor VIII coagulant activity (VIII:C) and vWf, measured as ristocetin cofactor activity (lower than 20% and 3% of normal respectively), but with a normal intraplatelet content of vWf, a test infusion of DDAVP (0.4 microgram/kg) elicited a very marked increase of VIII:C and vWf and normalized the bleeding time. All these patients subsequently underwent tooth extraction after DDAVP infusion. The incidence of bleeding was remarkably low, with only two minor late bleeding episodes easily stopped by repeating DDAVP infusion. Compared to the cases of type I vWd with unknown intraplatelet vWf content reported in the literature, this subgroup of patients had a more marked, albeit short-lived, increment of VIII:C and vWf.

Adolescent↗
PubMed1988

von Willebrand disease "Vicenza" with larger-than-normal (supranormal) von Willebrand factor multimers.

When normal volunteers or patients with type I von Willebrand disease (VWD) are given desmopressin (DDAVP), a set of larger-than-normal (supranormal) von Willebrand factor (VWF) multimers, similar to those present in VWF-containing cells such as platelets megakaryocytes and endothelial cells, appear transiently in postinfusion plasma. In two kindreds with mild lifelong bleeding symptoms transmitted as an autosomal dominant trait, all ten symptomatic members (but none of the five asymptomatic members) had a supranormal multimeric structure for plasma VWF, apparently identical to that seen for postdesmopressin normal plasma. Plasma factor VIII coagulant activity (VIII:C), VWF antigen (VWF:Ag), ristocetin-induced platelet agglutination, and ristocetin cofactor (RiCof) activity were low. Platelet VWF:Ag and RiCof levels (tested for three patients only) were normal. Bleeding times were normal or slightly prolonged. The patients' platelet multimeric structure was the same as that for normal platelets. After desmopressin infusion the plasma VWF multimeric structure remained supranormal as for preinfusion plasma, with VIII:C VWF:Ag and RiCof increasing markedly over baseline values and disappearing at a normal rate. Examination of the VWF subunit composition from three of these patients indicated that proteolytic processing of their VWF did not differ from normal. This study describes the first variant of VWD with a supranormal multimeric structure.

Blood Platelets↗
PubMed1987

Calibration of lyophilized standards for ristocetin cofactor activity of von Willebrand Factor (vWF) requires vWF-deficient plasma as diluent for dose-response curves.

Calibration of local standards for ristocetin cofactor activity of von Willebrand's factor (vWF:Rcof) against reference preparations is required to achieve a better standardization of this measurement. We have observed that in calibration assays (multiple line parallel bioassay) for vWF:Rcof, measured aggregometrically, the type of diluent used to obtain the dose-response curves exerted a critical influence on the final potency estimation when a fresh-frozen plasma against a lyophilized standard or two lyophilized preparations were to be compared. This pattern was observed with various commercial standards and also with the First International Reference Preparation for Factor VIII-Related Activities in Plasma. The choice of diluent was not relevant if two fresh-frozen plasma preparations were to be calibrated. Systematic experiments using as diluents Tris-saline, Tris-buffered-albumin solution or vWF-deficient plasma (vW-plasma) showed that the ratio lyophilized/fresh-frozen preparations was invariably lower with albumin solution than with vW-plasma. Tris-saline partially corrected this discrepancy, but yielded less precise estimates. Preliminary results with cryosupernatant-plasma seems to indicate that this material is a valid substitute for vW-plasma, but confirmatory experiments are required. For the moment, plasma obtained from patients with severe type III vW-disease should be considered the "ideal" diluent for calibration assays involving lyophilized preparations.

Freeze Drying↗
PubMed1987

Fibrinogen Vicenza and Genova II: two new cases of congenital dysfibrinogenemia with isolated defect of fibrin monomer polymerization and inhibitory activity on normal coagulation.

Two new cases of congenital dysfibrinogenemia are presented in which defective fibrin monomer polymerization and inhibitory activity on normal coagulation were observed. They have been tentatively called fibrinogen Vicenza and Genova II. The first was discovered in a family with mild bleeding diathesis, the second in an asymptomatic family. In almost all reported cases of fibrinogens with defective fibrin monomer polymerization, additional functional or structural defects have been detected. In our cases, on the contrary, detailed investigations failed to show any other abnormality. Fibrinogen Genova II is apparently identical to fibrinogen Baltimore IV, whereas fibrinogen Vicenza is similar to fibrinogen Troyes and Genova I, but also exerts an evident inhibitory activity on normal coagulation and differs from fibrinogen Genova II and Baltimore IV showing a different kinetic pattern of fibrin monomer polymerization.

Adult↗