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Biomedical subjects

M G Mazzucconi

Publications and source records attributed to M G Mazzucconi.

At least 55 records · Page 3Linked to original sources
PubMed1986

Pipobroman therapy of essential thrombocythemia.

We report our results with pipobroman (PB) therapy in patients with essential thrombocythemia (ET). 21 consecutive untreated patients were treated with PB from 1975 to 1984. PB was given at a dose of 1 mg/kg/d until platelet count dropped below 600 X 10(9)/l. In 18 patients (86%) a hematological remission was obtained. Median duration of induction phase was 49 d. In all cases a maintenance regimen was required at a dose ranging from 0.2 mg/kg/d to 0.5 mg/kg/d, according to platelet number. Follow-up of responder patients ranged from 6 to 108 months (median 17 months). Treatment was well tolerated and we observed only a very moderate and transient hematological toxicity. No patient had relapsed or developed secondary neoplasms at the time of writing. Median survival time of all patients was 24 months (range 10-115).

Adult↗
PubMed1985

Carrier detection in factor VII congenital deficiency.

Thirty obligate and 28 possible carriers of factor VII congenital deficiency, belonging to 16 families, were studied in relation to the immunological variants to which the kindreds belonged, namely, VII+, VIIR and VII-. Factor VII activity and antigen determinations in these subjects formed two phenotypical patterns: a discrepant pattern characterized by a low ratio activity/antigen present in VII+ heterozygotes, and a non-discrepant pattern (normal ratio activity/antigen) which is present in the VII- and VIIR variants. In the first genetic variant the detection of carriers can be performed using the ratio VII:C/VII:Ag. In the other variant, which accounts for the vast majority of heterozygotes, the distribution of the carriers' factor VII is so widespread that a large overlap results between these subjects and the normals. The application of a probabilistic calculation performed by combining the actual values of factor VII:C and the genetic probability of carriership using Fisher's linear discriminant analysis, makes discrimination between carriers and normals easier.

Adolescent↗
PubMed1985

Heterogeneity of type I von Willebrand disease: evidence for a subgroup with an abnormal von Willebrand factor.

Type I von Willebrand disease (vWD) is characterized by equally low plasma concentrations of von Willebrand factor antigen (vWF:Ag) and ristocetin cofactor (RiCof) and by the presence of all vWF multimers in sodium dodecyl sulfate (SDS)-agarose gel electrophoresis. For 17 patients (13 kindreds) diagnosed with these criteria, we have studied the platelet contents of vWF:Ag and RiCof and the changes of these in plasma after DDAVP infusion. Platelet vWF:Ag and RiCof were normal in four kindreds (called "platelet normal" subgroup); following 1-deamino-8-D-arginine vasopressin; plasma vWF:Ag, RiCof and the bleeding time (BT) became normal. In six kindreds, platelet vWF:Ag and RiCof were equally low (platelet low); after DDAVP, plasma vWF:Ag and RiCof remained low, and the BT was prolonged. In three additional kindreds, platelets contained normal concentrations of vWF:Ag, but RiCof was very low (platelet discordant); even though a complete set of multimers was found in plasma and platelets, there was a relatively small amount of large multimers. After DDAVP, plasma vWF:Ag became normal, but RiCof remained low and the BT was very prolonged. These findings demonstrated that there can be an abnormal vWF (RiCof less than vWF:Ag) even in type I vWD, coexisting with a complete set of vWF multimers (platelet discordant); that the abnormal vWF can be shown more clearly in platelets than in plasma or else in plasma after DDAVP infusion; and that DDAVP normalizes the BT only in those patients with normal platelet levels of both vWF:Ag and RiCof (platelet normal).

Autoradiography↗
PubMed1985

Inhibitor to factor V in severe factor V congenital deficiency. A case report.

A case of severe factor V deficiency that developed an inhibitor to factor V following the treatment with fresh frozen plasma (FFP) is described. The patient had a CRM-negative form of factor V congenital deficiency: no factor V antigen could be assayed in her plasma. A sister who supposedly had a severe factor V deficiency died as a result of a severe posttransfusional hepatitis. Two other members of the family were found to be heterozygotes. After several exposures to FFP, the propositus became refractory to the treatment with the appearance of a low titre inhibitor (5 units) which, nevertheless, could not be overcome by plasma infusions.

Blood Coagulation↗
PubMed1984

Evaluation of the effectiveness of DDAVP in surgery and in bleeding episodes in haemophilia and von Willebrand's disease. A study on 43 patients.

1-deamino-8-D-arginine-vasopressin (DDAVP), was used in a wide spectrum of clinical situations employing two different dosages (0.3 and 0.4 microgram/kg b.w.) for the management of 43 patients with factor VIII deficiencies--mild and moderate haemophilia A and von Willebrand's disease (vWD). In most instances, the drug was given in association with antifibrinolytics. Twenty-five dental extractions were carried out with two different protocols: one based upon a single infusion and the other based upon three infusions. Bleeding occurred in three patients regardless of the protocol used. The vasopressin analogue promptly stopped bleeding in 12 'spontaneous' open bleeds (haematuria, epistaxis, menometrorrhagia, gum bleeding) and it appears to be also effective in closed bleeds. DDAVP was used to minimize blood loss during surgical interventions and to avoid haemorrhage in the postoperative period. Nine surgical procedures were carried out in six vWD patients and three haemophiliacs. Bleeding occurred late in the postoperative period on one occasion only. No difference was demonstrated between the two doses of the drug either in terms of clinical benefit or rise of factor VIII coagulant activity. The efficacy of DDAVP and the absence of side-effects make this vasopressin analogue worthy of consideration as a reliable alternative to factor VIII concentrates in a wide variety of clinical situations.

Antigens↗
PubMed1984

Studies on PIVKA VII.

In 30 subjects on stabilized oral anticoagulant treatment, factor VII activity (VII:C) and factor VII antigen (VII:Ag) were evaluated. The average VII:C and VII:Ag levels were 8.7 and 30.7, respectively. All plasma samples were treated with 1 M barium chloride: all the activity and a corresponding average amount of antigen were adsorbed by the salt. The cold-promoted activation of factor VII was found in 5/30 subjects. Corresponding amounts of VII:C and VII:Ag were also removed from the plasma of these subjects after cold activation following the addition of barium chloride. It clearly results from these studies that a portion of VII:Ag cannot be adsorbed by barium chloride because of a reduction (or a lack) of the gamma-carboxyglutamic groups. This portion of VII:Ag can therefore be identified as Pivka VII.

Acenocoumarol↗
PubMed1984

Detection of drug-dependent IgG antibodies with antiplatelet activity by the antiglobulin consumption assay.

Drug-induced thrombocytopenia is a common acquired hemorrhagic disorder. In this study 32 patients with drug-induced thrombocytopenia were examined with the antiglobulin consumption assay. Platelet-associated IgG was elevated in 19 of 20 patients that were analyzed. An increase in serum platelet bindable IgG was observed in 24 subjects after the addition of various drugs (acetylsalicylic acid, noraminopyrine, antibiotics, sulfamides, digoxin, heparin and chenodeoxycholic acid). These findings are significant for the presence of drug-dependent platelet antibodies.

Adolescent↗
PubMed1983

Factor VII congenital deficiency. Clinical picture and classification of the variants.

In congenital factor VII deficiency the clinical picture is related to the levels of factor VII coagulant activity; when factor VII:C levels are very low the bleeding episodes can occur frequently. The most frequent bleedings are menorrhagia and metrorrhagia in females and hemarthrosis in both sexes. There are 3 immunological variants of factor VII deficiency: VII-, VIIR and VII+. Conversely, the genetic variants are 2: one characterized by no discrepancy between VII:C and VII:Ag (found in the heterozygotes of VII- and VIIR variants) and the other, in which a discrepancy between VII:C and VII:Ag is found (heterozygotes from VII+ kindreds). In factor VII deficiency, most commonly the human and ox tissue factors show the highest sensitivity to the coagulation defect, whereas the one extracted from rabbits is definitely less sensitive; the definition of functional variants is based upon a different reactivity to homologous and/or heterologous tissue thromboplastins. In no case was a PIVKA-VII-like protein found and none of the factor VII defective molecules reacted to the generation of important kallikrein activity.

Animals↗
PubMed1983

A variant of von Willebrand's disease characterized by recessive inheritance and missing triplet structure of von Willebrand factor multimers.

A 10-yr-old girl had bleeding symptoms of moderate severity; her mother and maternal aunt had milder bleeding symptoms, and other members of the kindred were asymptomatic. In the child, factor VIII coagulant activity (VIII:C) and von Willebrand factor antigen (vWF:Ag) were normal, ristocetin cofactor very low, and the bleeding time (BT) markedly prolonged. These values were normal in the rest of the kindred, but the mother and maternal aunt had prolonged BT and a high VIII:C/vWF:Ag ratio. Crossed immunoelectrophoresis (CIE) showed a vWF:Ag peak migrating more anodally in the propositus, two distinct peaks, one migrating anodally, in the father, paternal uncle, and grandmother, and normal peaks in the rest of the kindred. In the propositus, analysis of vWF multimers in plasma on 1.6% sodium dodecyl sulfate (SDS) agarose revealed that there were no larger multimers and there was a relative increase of the smallest multimer. This relative increase was also seen in her relatives with a double peak on CIE. Using gels of smaller porosity, each multimer of the propositus's plasma consisted of a single band, instead of the repeating triplet seen in normal and von Willebrand's disease varients types IIA and IIB. The abnormalities found in the propositus are tentatively interpreted as being due to double heterozygosity for two different genes. The defective gene carried by the father affects the triplet structure of vWF multimers, whereas a prolonged BT and a high VII:C/vWF:Ag ratio are the only phenotypic expressions of the defective gene of the mother. The findings of aberrant triplet structure in congenital vWD strengthen the view that this structure is an intrinsic feature of the normal vWF molecule.

Autoradiography↗
PubMed1981

Factor VII deficiency: immunological characterization of genetic variants and detection of carriers.

Twenty-one patients with congenital factor VII deficiency belonging to 16 different kindreds were investigated. The existence of three immunochemical variants on the ground of factor VII activity (VII:C) and factor VII-related antigen (VII:Ag) levels (VII-, VII+ and VIIR) was established. There was no correlation between the presence of factor VII:Ag and either the clinical picture or the specific function as studied with the Km calculations. Genetically the model of inheritance is the same whatever the immunological variant, but the identification of carriers is simplified when the presence of factor VII-related antigen is assayed throughout a kindred.

Antigens↗
PubMed1981

Chronic idiopathic thrombocytopenic purpura (ITP): site of platelet sequestration and results of splenectomy. A study of 197 patients.

51Cr-platelet kinetics study was performed in 197 patients with chronic ITP after corticosteroid therapy had failed to induce a long lasting remission. The incidence of splenic, spleno-hepatic, hepatic and diffuse platelet sequestration site was 58%, 17%, 6% and 19%, respectively. Splenic and spleno-hepatic sequestration sites were more frequent in patients less than 30 years old and in patients with a platelet count lower than 50 x 10(9)/1. 111 patients were splenectomized shortly after the study. Normalization of the platelet count was obtained more frequently in patients with splenic and spleno-hepatic sequestration than in the others. Labelled platelet sequestration site was the best predictor of the outcome of splenectomy. Platelet kinetics is a non-invasive investigation that should be performed early after the diagnosis of chronic ITP in all patients eligible for splenectomy.

Adolescent↗
PubMed1980

Factor VII activity and antigen in haemophilia B variants.

Twenty three patients belonging to 18 different pedigrees of Haemophilia B were studied with regard to ox-brain prothrombin time and its correlation to factor VII. Eleven among them were B-negative (no detectable factor IX antigen), five were B-reduced (factor IX antigen detectable but below the normal values) and seven were B-positive (normal levels of factor IX antigen). Ox-brain prothrombin time was found prolonged (greater than or equal to mean + 2.5 SD:99% confidence limits) in nine patients. Factor VII Activity (VII:C) was found reduced in 1/11 B-negative, in 2/5 B-reduced and in 4/7 B-positive patients. Factor VII Antigen (VII:Ag) was found normal in all but one patient. The ratio VII:C/VII:Ag was abnormal in eight patients independently from the variant of Haemophilia B. The underlying defect which causes the prolongation of Ox-brain prothrombin time due to factor VII:C mild deficiency is heterogeneous. Age, a mild Vitamin K deficiency, the presence of an inhibitor of Factor VII activation and other unknown causes, may be responsible for this pattern.

Adult↗
PubMed1980

Deflazacort in thrombocytopenia: a comparison with prednisone.

Deflazacort is a new glucocorticoid which in previous studies was found to be about 0.8 times as potent as prednisone. Twelve outpatients affected by chronic idiopathic thrombocytopenic purpura, in whom the maintenance dose of corticosteroid had already been established, were given 6 mg deflazacort for each 5 mg prednisone equivalent. Effectiveness of deflazacort therapy was estimated on the basis of the results of platelet count, bleeding time, tourniquet test, and physical signs related to platelet function. Tolerability was evaluated on the basis of laboratory data, side effects, and body weight. Deflazacort was administered for 54--263 days (mean 114.5) and, at the same mean daily dose of prednisone, succeeded in keeping platelet number unchanged. As far as bleeding time, tourniquet test, and physical signs are concerned, deflazacort therapy gave a further improvement compared to prednisone. Both treatments were very well tolerated. The high number of white blood cells and neutrophils during prednisone therapy was restored to the normal range by deflazacort.

Adolescent↗
PubMed1978

Treatment of congenital factor VII deficiency with a new concentrate.

A new factor VII concentrate, made from ACD plasma by a process involving successive absorptions of cryoprecipitate supernatant on DEAE Sephadex and of the resulting supernatant on A1(OH)3, was administered to 10 patients with severe factor VII deficiency. 5 patients received only one dose for treatment of a single bleeding episode, the remaining 5 were given multiple infusions (47) for spontaneous hemorrhages or for the prevention of surgical bleeding. In vivo factor VII recovery ranged from 43 to 126% (average 88%) of the assayed in vitro activity of the concentrate. A dose of 0.5 u/kg was found to produce a 1% rise of the plasma factor VII levels. The mean half-life on injected factor VII as assessed in 7 kinetic studies was 205 min (range 168--234). Spontaneous bleeding was easily controlled by the concentrate and major surgical procedures (two tonsillectomies) could be performed without complications. 1 patient developed HBSAg positive hepatitis, but otherwise no serious side effects were observed. Factor VII concentrate reduced the risk of precipitating circulatory overload associated with the use of plasma and avoids the unnecessary rise of factor II, IX and X which follows prothrombin complex concentrates.

Adolescent↗
PubMed1977

A CRM-Positive variant of factor-VII deficiency and the detection of heterozygotes with the assay of factor-like antigen.

Nine patients with severe factor-VII deficiency, belonging to seven pedigrees were studied for the presence of factor-VII-CRM with an inhibitor neutralization assay. The antibody, raised in rabbits, did not precipitate the antigen and could only be used in a fluid phase assay to measure the capacity of plasma to neutralize inhibitory activity directed against factor-VII activity. In one of these nine patients normal amounts of factor-VII-CRM could be demonstrated. The CRM + patient did not show a clinical picture at variance with that of the CRM-patients. The investigation into this CRM+ pedigree revealed heterozygosity in nine out of 12 persons when using the ratio between biological factor-VII activity and factor-VII-CRM as the criterion.

Adolescent↗