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Biomedical subjects

A Girolami

Publications and source records attributed to A Girolami.

At least 559 records · Page 31Linked to original sources

An immunological investigation of factor VIII associated antigen in combined factor V and factor VIII deficiency.

The behavior of factor VIII associated antigen of three patients with combined factor V and factor VIII deficiency has been evaluated in several immunological systems. Factor VIII associated antigen resulted to be normal or higher than normal in all three patients in the radial immunodiffusion and in the electroimmunoassay systems. In the bidimensional electrophoresis system only one factor VIII precipitate was evident and such factor VIII precipitate showed the same electrophoretic mobility as normal factor VIII antigen. These findings firmly establish the fact that the factor VIII defect in congenital combined factor V and factor VIII deficiency is of the hemophilia type.

Antigens↗

Decrease of normotest/thrombotest discrepancy in non-contacted coumarin plasma after glass or ellagic acid activation.

Activation of coumarin plasmas in glass tubes for 60 min resulted in a clear shortening of Thrombotest clotting times. Normotest clotting times were shortened too but to a much lesser extent. As a consequence the Normotest (NT)/Thrombotest (TT) discrepancy which was quite large at 0 time, became progressively smaller. This phenomenon was observed both in undiluted and 6:10 diluted plasma. After ellagic acid activation a similar phenomenon was noted even though a less pronounced shortening of Thrombotest was noted. These data suggest that Thrombotest is very sensitive to contact phase and to factor VII activation and not to any coumarin-induced inhibitors.

Blood Coagulation Tests↗

Combined deficiency of factor V and factor VIII. A report of another case.

A patient with combined factor V and factor VIII deficiency is presented. The bleeding manifestations were: easy bruising, post-traumatic bleeding, bleeding after tooth extractions. The main laboratory feature was a prolonged partial thromboplastin time which was corrected by the addition of adsorbed normal plasma but not by the addition of normal serum, hemophilia A plasma of another patient with combined factor V and factor VIII deficiency. The thromboplastin generation test was clearly abnormal and was corrected by the addition of adsorbed normal plasma but not by addition of normal serum. Prothrombin consumption was also defective. Prothrombin time was slightly prolonged too, Thrombin time, platelet and vascular tests were within normal limits and there was no hyperfibrinolysis. Factor VIII was 8% of normal, whereas factor V was 14% of normal. Factor VIII associated antigen was normal. All other clotting factors were within normal limits. The parents of the propositus were consanguineous (first cousins) but had normal factor V and factor VIII activity and normal factor VIII antigen. The same was true for other family members. The hereditary transmission of the condition appears autosomal recessive.

Blood Coagulation Tests↗

Increased whole blood viscosity on cooling in a patient with cold hemoagglutinin disease.

The whole blood and plasma viscosities have been evaluated in a patient with cold hemoagglutinin disease at different temperatures and at different shear rates. At 37 and 42 degrees C, whole blood viscosity values, regardless of the shear rate applied, resulted to be correspondent to the hematocrit value (31%). The values observed were similar to those noted in a patient with chronic bleeding anemia and an approximately equivalent hematocrit (33%). The same was true for plasma viscosity. At 32 degrees C, whole blood viscosity, regardless of the shear rate, resulted to be higher than expected. The values observed were similar to those noted in a normal subject with a clearly higher hematocrit value (44%) and definitely higher than those noted in the chronic anemia patient. On the contrary, plasma viscosity remained unchanged. These studies indicate that in cold hemoagglutinin disease, red cell aggregation and piling are capable of increasing blood viscosity.

Aged↗

Factor X Friuli coagulation disorder. Report of a newly recognized patient and some considerations on the frequency of the disease in the Friuli area.

A newly recognized patient with the factor X Friuli coagulation disorder is presented. The propositus is a 10-year-old boy who presented excessive bleeding after a tooth extraction. This is the 11th patient with this peculiar coagulation disorder discovered in Friuli and the 12th so far described. His parents are consanguineous and heterozygotes together with other family members. The main laboratory features, typical of the disease were prolonged prothrombin time, a prolonged partial thromboplastin time, and a normal Stypven-cephalin clotting time. The incidence of the homozygotes in the Friuli area appear to be 0.000005 (11 cases in a population of 2,000,000). The probable frequency of the abnormal f gene is 0.0033, whereas that of the normal gene F is 0.9967. The theoretical frequency of the heterozygote, Ff condition is 0.007, namely 7 heterozygotes every 1,000 persons. However, only about 70 ascertained heterozygotes have been discovered so far.

Adolescent↗

The effect of ionophore on platelet aggregation in von Willebrand's disease and in congenital afibrinogenemia. A comparison with ristocetin.

Platelet aggregation in citrated and heparinized plasma by ionophore A 23187 and Ristocetin was studied in normal subjects and in patients with von Willebrand's disease and congenital afibrinogenemia. Aggregation by ionophore was normal in all groups both in citrated and heparinized plasma. Aggregation by Ristocetin in citrated plasma was normal in congenital afibrinogenemia, in normal subjects and in types II and III of von Willebrand's disease. It was absent in classical von Willebrand's disease, type I. In heparinized plasma it was absent in all groups, except in some patients with von Willebrand's disease, type III. It is concluded that ionophore A 23187 behaves in a different way than Ristocetin and has no diagnostic implications.

Afibrinogenemia↗

Platelet aggregation and adhesiveness in classical factor X deficiency and in the abnormal factor X (factor X Friuli) coagulation disorder.

Platelet aggregation to common inductors and to Ristocetin, Thrombofax and Ionophore is normal in congenital factor X deficiency and in factor X Friuli coagulation disorders. Washed normal platelets resuspended in the patient's plasma and in adsorbed normal plasma showed a normal aggregation. On the contrary, normal platelets resuspended in normal serum failed to aggregate. These studies indicate that factor X plays no role in normal platelet aggregation.

Adenosine Diphosphate↗

Combined hereditary deficiency of factors VII and VIII: a distinct coagulation disorder due to the 'lack' of an autosomal gene controlling factor VII and VIII activation?

A patient with a combined hereditary deficiency of factors VII and VIII is presented together with a family study. The main bleeding manifestations were easy bruising and bleeding after tooth extractions. No hemarthrosis was ever observed. The main laboratory features consisted in a mild prolongation of prothrombin time and of partial thromboplastin time. TG test was abnormal and was corrected by the addition of adsorbed normal plasma. Specific assays revealed a moderate defect of factors VII and VIII. All other clotting factors were within normal limits. The factor VII antigen in the propositus was normal or nearly normal. The factor-VIII-associated antigen was also normal. Five additional family members presented the same coagulation pattern and were variably symptomatic. The hereditary transmission pattern seems to be autosomal dominant. The defect appears to be due to a structural abnormality of a gene controlling factors VII and VIII activation.

Adult↗

Combined congenital deficiency of factor V and factor VIII. Report of a further case with some considerations on the hetereditary transmission of this disorder.

A patient with combined factor V and factor VIII deficiency is presented. The bleeding manifestations were mild. The main laboratory feature was a prolonged partial thromboplastin time which was corrected by the addition of adsorbed normal plasma but not by the addition of normal serum, hemophilia A plasma or plasma of another patient with combined factor V and factor VIII deficiency. TGT was also clearly abnormal and was corrected by the addition of adsorbed normal plasma but not by the addition of normal serum. Prothrombin consumption was mildly defective. The prothrombin time was slightly prolonged. Facotr VIII was 12% and factor V 55% of normal. Factor-VIII-associated antigen was normal. The father and a sister of the propositus revealed mild factor V deficiency but normal factor VIII activity and antigen. The parents were not consanguineous. A tentative classification of combined deficiency of factors V and VIII in two groups is proposed. The hereditary transmission of the two types of deficiencies is discussed.

Adult↗

Failure of tranexamic acid to influence the ellagic acid-induced hypercoagulable state.

Tranexamic acid in a dose of 50 mg/kg b.w. was unable to alter the ellagic acid induced hypercoagulable state. No change in the hypercoagulability pattern was observed regardless of the time of administration of the compound (before or after the ellagic infusion). The silicone clotting times after the infusion of ellagic acid were markedly shortened and remained so for about 60 minutes. The results observed in two control groups treated with saline were similar. The euglobulin lysis times were clearly prolonged after the administration of tranexamic acid, whereas no changes were observed after the administration of saline. These results indicate that tranexamic acid has no anti-factor XII activity.

Animals↗

The "echis carinatus venom" prothrombin assay in coumarin treated patients. A comparison with one-stage and immunological assays.

Prothrombin (factor II) was assayed in a group of coumarin treated patients using the Echis carinatus venom as thromboplastin. The levels obtained were comparable to those observed using the classical one-stage method. A good correlation was in fact observed between the two methods. The levels observed by the Echis carinatus method were definitely lower than those obtained using two immunological methods indicating that Echis carinatus venom activated, in our system, only normal prothrombin. However, even the levels obtained immunologically were slightly decreased, regardless of the method used, as compared to pooled normal plasma. In congenital prothrombin deficiency (homozygotes and heterozygotes) the level obtained by the Echis carinatus method was comparable to that observed by the one-stage method. On the contrary, in a congenital dysprothrombinemia (prothrombin Padua) a normal level was observed whereas the one-stage and two-stage methods yielded constantly levels of about 50% of normal.

Animals↗

The effect of heparin on platelet aggregation by common inductors and by ristocetin in congenital bleeding disorders due to factor VIII or fibrinogen defects.

Platelet aggregation by various inductors was studied in citrated and heparinized plasma of the following groups of subjects: Normal, hemophilia A, combined factor V and factor VIII deficiency, v. Willeprand's disease and congenital afibrinognemia. The results may be summarized as follows: A-platelet aggregation in citrated plasm 1) platelet aggregation by common inductors ADP, adrenalin and collagen was normal in all groups of subjects but for the patients with congential afibrinogenemia in whom adrenalin induced aggregation was absent or markedly refuced whereas ADP and collagen gave slightly reduced or near normal aggregation curves. 2) platelet aggregation by ristocetin was normal in all groups of subjects but for v. Willebrand's disease in which it was absent. B-platelet aggregation in heparized plasma. 1) platelet aggregation by common inductors resulted to be normal in all groups of subjects except in congenital afibrinogenemia. In this latter case the pattern was still mildly defective but here was an increased aggregation as compared to citrated plasma. These findings have been interpretemmon inductors. 2) platelet aggregation by ristocetin resulted to be absent in all groups of subjects investigated. The possible mechanism of action of the inhibitory effect exercised py heparin with regard to restocetin is discussed.

Adenosine Diphosphate↗

Failure of ellagic acid to affect platelet aggregation in normal and in factor XII deficient plasma.

Ellagic acid solutions, regardless of the concentration, failed to alter platelet aggregation induced by ADP, Adrenalin, Collagen, Thrombofax and Ristocetin in normal and in factor XII deficient plasma. A moderate inhibition was noted after addition of ADP both in normal and in factor XII deficient plasma but this was present also in the control systems and was therefore due to the buffer-dextrose solution and not to ellagic acid. These data indicate that Hageman factor plays on role in platelet aggregation.

Adenosine Diphosphate↗

Factor X Friuli: An immunological study in plasma and in serum using several methods.

An immunological study of factor X Friuli was carried out using an anti-human-factor X antiserum. The results obtained with different methods were compared. Only an ill-defined factor X band or precipitate was evident on standard immuno-electrophoresis and on immunodiffusion. Using a non-absorbed antiserum a precipitate was evident on eletroimmunoassay, in normal, factor X Friuli and in factor X deficient plasma. On the contary, using an antiserum which had been previously absorbed with factor X deficient plasma, a precipitate was evident only with factor X Friuli plasma or normal plasma. Excellent results were obtained with the cross-over electrophoresis. Using this method a major or factor X band was evident in normal plasma, factor II,P FACTOR VII, factor IX deficient plasmas and in the factor X FRIULI PLASMA. No factor X band was evident in factor X deficient plasmas and in absorbed normal plasma. Lighter, more cathodic bands were seen in all plasmas. These were due to secondary activities of the antiserum and could be disregarded. Friuli serum factor X and normal serum factor X showed a slightly more anodic migration as compared to their plasma counterparts. In coumarin plasma two factor X bands were evident; one normal in position and one slightly more catholidic. In the bidimensional immunoelectrophoresis two precipitates are visible in normal plasma and in factor X Friuli plasma. In factor X deficient plasma only one precipitate is evident. This latter precipitate is due to the secondary activity of the antiserum used. On the basis of these data it is concluded that factor X Friuli behaves, immunologically, as normal factor X.

Blood Coagulation Disorders↗

Platelet adhesiveness and aggregation in congenital afibrinogenemia. An investigation of three patients with post-transfusion, cross-correction studies between two of them.

Platelet adhesiveness and aggregation were studied in three patients with congenital afibrinogenemia. The results obtained may be summarized as follows: The retention of platelets to a glass-bead filter determined with the Salzman method was significantly decreased; it was normal after fibrinogen infusion. With a modification of the Hellem test the values obtained were slightly decreased. Adrenalin-induced aggregation was absent whereas ADP-and collagen-induced aggregation was near normal or slightly decreased. Thrombofax aggregation was absent in citrated plasma. The abnormalities of platelet aggregation were corrected after fibrinogen infusion or after addition in vitro of fibrinogen, hemofilia A plasma and PPP obtained from an afibrinogenemic patient after fibrinogen infusion. The abnormalities of platelet aggregation were corrected well by ADP, collagen and Thrombofax in heparinized blood, but only a slight correction of adrenalin-induced aggregation was noted. Thrombin aggregation proved to be normal with the higher concentrations, whereas it was defective with the lower ones. Ristocetin aggregation was normal in citrated plasma at the concentration of 1.5 mg per ml but it was absent at the lower concentration (1.0 mg per ml). Ristocetin aggregation was, on the other hand absent in heparinized blood regardless of the concentration. These findings are in agreement with the presence of a prolonged bleeding time in congenital afibrinogenemia and suggest that fibrinogen plays an important role in platelet aggregation and adhesiveness.

Adenosine Diphosphate↗

The K-test (trypsin clotting time) in coumarin treated patients and in congenital deficiencies and abnormalities of the prothrombin complex.

The behavior of K-test (Trypsin clotting time) has been studied in 38 patients on long-term coumarin therapy and in 19 patients with congenital coagulation disorders of the prothrombin complex. All coumarin treated patients showed a clear prolongation of the test. The results obtained were compared with the standard prothrombin time, the Hepato-Quick-test (P-P test) and the Factor II + X test values, observed in the same patients. A good correlation was observed in each instance. The highest correlation was observed between K-test and the Factor II + X test (r=+0,78;t=7,80;p less than 0.001). All congenital coagulation disorders of the prothrombin complex yielded a prolonged K-test value but for Factor VII deficiency. In three patients with this latter condition a perfectly normal value was obtained. The K-test together with the prothrombin time may be useful in the differential diagnosis of factor VII deficiency from factor X deficiency and from the factor X Friuli abnormality.

Blood Coagulation Disorders↗

The effect of several viper venoms on prothrombin Padua.

The effect of four viper venoms (Oxyuranus scutellatus, Notechis scutatus scutatus, Echis carinatus, Naja nigricollis) on prothrombin Padua has been studied. Using Oxyuranus scutellatus venom and Notechis scutatus scutatus venom, prothrombin activity resulted to be moderately decreased similarly to what observed with other one-stage and two-stage methods. On the contrary, using Echis carinatus venom a normal level was obtained. No clotting was observed using the Naja nigricollis venom, regardless of the concentration used. The normal level of factor II obtained with Echis carinatus venom as compared with the low levels obtained with the other venoms, suggests that it acts on a different site of the prothrombin molecule.

Animals↗