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Biomedical subjects

B Bizzi

Publications and source records attributed to B Bizzi.

At least 73 records · Page 4Linked to original sources
PubMed1985

Serum beta 2-microglobulin in systemic sclerosis.

The role of beta 2 microglobulin (beta 2-m) in Systemic Sclerosis (SS) has been evaluated. Twenty-four female patients have been examined: 15 of them were affected by acrosclerosis (Group 1) and 9 of them by diffuse sclerosis (Group 2). 46.6% of Group 1 and 44.4% of Group 2 had values significantly higher than normal controls. (P less than 0.01 and P less than 0.005 respectively). The authors deal with the validity of the use of B2-m as index of inflammatory activity of the disease.

Adult↗
PubMed1984

Different forms of AT-III congenital defect: a study by crossed immunoelectrofocusing.

Antithrombin III (AT-III) deficiency may be due to quantitative or qualitative AT-III reduction. The diagnosis of qualitative disorder is suspected when a discrepancy is found between immunological and functional levels of AT-III. Heterogeneity has been hypothesized in both quantitative and qualitative deficiency of AT-III. A technique based on crossed immunoelectrofocusing (CIEF) was applied to investigate molecular variants of AT-III. 3 families with low functional and immunological levels of AT-III and 1 family with only a low functional AT-III level were investigated. An abnormal AT-III pattern was found with CIEF in the family with suspected qualitative disorder and in 1 of the families with quantitative disorder. The 2 abnormal patterns were different. Thus the use of CIEF AT-III patterns could help to define congenital AT-III deficiencies and could serve as a basis for classification of different forms of AT-III deficiency.

Adult↗
PubMed1983

Coagulation disorders in patients with tumors of the uterus.

Sixty-eight previously untreated female subjects were studied: 26 patients with cervical carcinoma, 22 with endometrial carcinoma, and 20 with benign uterine diseases. These patients, together with 25 healthy female control subjects, underwent several coagulation tests, including beta-thromboglobulin (beta-TG) and platelet factor 4 (PF4) plasma levels. Of all the parameters considered, the variations in beta-TG and PF4 were the most interesting. They were increased in patients with cervical and endometrial carcinoma. The sensitivity of the two tests reached 79% (15/19) for patients with invasive cervical carcinoma and 74% (16/22) for all patients with endometrial carcinoma. Our data demonstrate that among the investigated parameters beta-TG and PF4 are the earliest disorders of the hemostatic system and are more frequently increased in the gynecologic malignancies.

Adenocarcinoma↗
PubMed1983

Evaluation of some coagulation parameters in cerebral ischemia.

In order to investigate some aspects of blood coagulation and of platelet function in cerebral ischemia, 18 healthy subjects, 24 patients with previous cerebral infarction and 12 patients with transient ischemic attacks were studied. All patients were in a non-active state of the illness. In all subjects, platelet count, prothrombin time, activated partial thromboplastin time and determination of the fibrinogen concentration were performed as routine. All subjects were tested for platelet adhesiveness, circulating platelet aggregates, factor VIII coagulant (VIII C), factor VIII-related von Willebrand factor (VII RWF), factor VIII-related antigen (VII RAg), antithrombin III (AT III) concentration and activity and euglobulin clot lysis time. No significant difference between patients and controls was found in routine tests, platelet function, AT III concentration or activity. Plasma levels of VIII C, VIII RWF, VIII RAg were significantly increased in both patient groups. The VIII RAg/VIII C ratio was significantly increased only in patients with previous cerebral infarction. Euglobulin clot lysis time was significantly increased in both patient groups.

Adult↗
PubMed1983

Antithrombin III and factor Xa inhibitor in atherosclerosis.

75 patients with atherosclerosis divided into five disease groups (previous myocardial infarction and cerebral thrombosis, angina pectoris, transient ischemic attacks, arteriosclerosis obliterans) were studied and compared to 20 healthy subjects. Antithrombin III (AT III) concentration was determined by single radial immunodiffusion; AT III and factor Xa-inhibitor (Xa-I) activities were measured by amidolytic methods. No significant difference was found in any group of patients as compared to normal controls by all the methods. A positive correlation was found between AT III concentration and AT III activity, AT III concentration and Xa-I activity, AT III activity and Xa-I activity. Results are discussed in relation to the literature data.

Adult↗
PubMed1983

[Beta-thromboglobulin and platelet regeneration time in children with mitral valve prolapse].

We studied 12 children with echocardiographic evidence of mitral valve prolapse (MVP) in order to demonstrate platelet activation or consumption as risk for thromboembolism. Therefore, with a standard radioimmunoassay, we measured the plasma levels of Beta-thromboglobulin (BTG), a platelet-specific protein released during platelet release reaction. Platelet turn-over was evaluated by measuring the Platelet Regeneration Time (PRT) with a non-radioisotopic method. Blood samples for BTG assay were collected at rest and after exercise. BTG plasma levels obtained in children with MVP were significantly higher than in normal subjects (p less than 0.01), both at rest and after exercise. We found no difference in either group between BTG level at rest and after exercise. The TRP was within the normal range in all patients except 2, in whom TRP was slightly shorter. Increased BTG levels and normal TRP suggest that in our patients platelet activation, but not consumption, was increased. In children with MVP, periodic controls of platelet activation may be useful to detect an increased risk of thromboembolism.

Adolescent↗
PubMed1982

[The factor VIII complex in atherosclerosis].

In order to investigate the factor VIII complex trend in atherosclerosis, 96 patients suffering from atherosclerosis, divided in 6 groups (angina pectoris, previous myocardial infarction, transient ischemic attacks, previous cerebral thrombosis, diabetes without symptoms of vascular injury and diabetes with vascular complications), were studied and compared to a control group of normal subjects. Plasma levels of Factor VII Coagulant (VIII C), Factor VIII-Related von Willebrand Factor (VIII-RWF) and Factor VIII-related Antigen (VIII ARg) were measured in all subjects. A significant rise of VIII RAg was noticed in all groups of patients as compared to the control group: this increase appears to be related to the severity of vascular injury. A significant rise of VIII RWF, parallel to the VIII RAg increase, was also noticed in all groups. Besides, all groups of patients showed a significant and uniform increase of VIII C. The average ratio of VIII RAg/VIII C was raised in all groups, except diabetics without complications; but the increase was statistically significant only in those patients with a heavier vascular injury which is related to the marked rise of VIII RAg in such clinical situations. The findings of this study are discussed in relation to the literature data. The significance of the determination of VIII RAg/VIII C ratio and of the VIII RAg assay as methods for monitoring the severity of the vascular injury in atherosclerosis are also discussed.

Adult↗
PubMed1982

Beta-thromboglobulin in patients with acute and chronic coronary artery disease.

Beta-thromboglobulin (beta TG) plasma levels were measured by radioimmunoassay in 14 patients with acute myocardial infarction (MI), in 13 with myocardial ischemia and recurrent episodes of angina and in 14 subjects with a past history of MI. Increased beta TG plasma values were observed in patients with acute MI and with myocardial ischemia whereas subjects with a past history of MI showed results not significantly different from normal subjects. Daily measurements in acute MI showed in five cases a second peak of beta TG values which suggests the occurrence of a deep vein thrombosis. The increased platelet consumption in MI was not related with the extent of the necrosis. We suggest, therefore, that platelet activation is associated with myocardial ischemia rather than necrosis.

Adult↗
PubMed1982

A comparative study on the effect of dilazep and dipyridamole on some platelet functions.

It was the purpose of this study to examine the effect of 1,4-bis[3-(3,4,5-trimethoxybenzoyl-oxy)propyl]-perhydro-1,4-diazepine (dilazep) on platelet function in vivo, compared with that of dipyridamole. 15 patients were given oral doses of 300 mg dilazep daily, and another 15 patients received oral doses of 450 mg dipyridamole daily. Blood was withdrawn 2 and 4 weeks after the start of treatment, in each case 2 h after administration of the drug. The results were as follows: bleeding time was prolonged in both groups; there was a percentage reduction of circulating platelet aggregates in both groups, but this was statistically significant in the dilazep group only; platelet aggregation was decreased in both groups, several parameters (minimum dose required to induce aggregation, collagen lag phase) were statistically significantly improved in the dilazep group only; platelet malondialdehyde production was unchanged; no changes were demonstrated in platelet shape, fibrinogen concentration, partial thromboplastin time, or prothrombin activity.

Adult↗
PubMed1981

Megathrombocytes, platelet regeneration time and platelet associated IgG in idiopathic thrombocytopenic purpura and in thrombocytopenia associated with chronic liver disease.

Percentage of megathrombocytes, platelet regeneration time (PRT) and platelet-Associated IgG (Pl-A-IgG) were investigated in 12 patients with clinical features consistent with idiopathic thrombocytopenic purpura and in 11 patients with thrombocytopenia associated with chronic liver disease. Bone marrow smears were also examined and megakaryocytes classified into stages I-III according to the current principle. Of 12 patients with idiopathic thrombocytopenic purpura the percentage of megathrombocytes was increased in 9, PRT reduced in 10, and Pl-A-IgG increased in 8 patients. A statistically significant correlation was found between the percentage of megathrombocytes and the level of Pl-A-IgG. A slight correlation was also found between PRT and the percentage of megathrombocytes, while a significant correlation was found between megakaryocytes in stage I and the percentage of megathrombocytes, suggesting that growth of megakaryocytes probably contributes to platelet heterogeneity. In patients with thrombocytopenia and chronic liver disease, the percentage of megathrombocytes was in the normal range. A moderately increased level of Pl-A-IgG was found only in patients with active chronic hepatitis, PRT was reduced only in a few patients, while most of them also showed an increase of Pl-A-IgG.

Blood Platelets↗
PubMed1980

Platelet-associated IgG in acute and chronic hepatic diseases.

In order to investigate the role of an immune mechanism in the pathogenesis of thrombocytopenia in hepatic patients, we measured platelet associated IgG (PAIgG) in 84 patients with various hepatic diseases. Increased PAIgG levels were found in 84% of patients with chronic active hepatitis (mean 21.32 +/- 8.45 fg/platelet) and in 75% of those with cirrhosis with hepatitis (mean 17.3 +/- 11.2 fg/platelet). In these patients there was no significant correlation between PAIgG and platelet count. Increased PAIgG amounts were also observed in some patients with inactive cirrhosis (18%). Normal PAIgG values were found in all patients with acute viral hepatitis and chronic persistent hepatitis. An immunologic mechanism may play a role in the pathogenesis of thrombocytopenia in hepatic patients. Furthermore, measurement of PAIgG may have a great usefulness in the differential diagnosis of chronic hepatic diseases.

Blood Platelets↗
PubMed1979

Human platelet aggregation by thimerosal. Functional and ultrastructural studies.

Thimerosal, a sulfhydryl group inhibitor, produces in an aggregometer a decrease in optical density of normal platelet-rich plasma over a wide range of concentrations. Ultrastructural study shows that the decrease of optical density produced by thimerosal at low doses is due to a true platelet aggregation preceded by a release reaction, whereas the aggregometric curves recorded after addition of thimerosal at high doses can be attributed to marked alterations of platelet morphology. Electron microscopic study shows the presence of electron-dense material between plasma membranes after addition of a low dose, and the early rupture of membranes after a high dose. These findings support previous conclusions that thimerosal binds to plasma membranes. Thimerosal induces a release reaction, seen in ultrastructural study and revealed by measurement of 14C-serotonin release. Moreover, thimerosal-induced aggregation is independent of released ADP and of formation of intermediates of the arachidonate pathway. Thimerosal-induced platelet aggregation is inhibited neither by ADP removal nor by aspirin addition.

Adenosine Diphosphate↗
PubMed1979

Platelet heterogeneity. Relationship between buoyant density, size, lipid peroxidation and platelet age.

Human platelets were separated into 2 density populations by repeated centrifugations of platelet-rich plasma at increasing gravitational force. The heaviest platelet fraction was rich in larger platelets. The lightest platelet fraction was rich in smaller platelets. In both fractions and in the platelet button, lipid peroxidation (malonaldehyde-MDA-production after addition of thrombin) was measured at basal condition, on the 1st, 3rd, 5th, 7th and 9th day after aspirin ingestion. At basal conditions and after ingestion of aspirin, MDA production was higher in the heavy-large platelets than in light-small ones, but a parallel increase of MDA production was observed in the light and in the heavy population and in the platelet button. The data are not compatible with the hypothesis that platelet density and size are age-related. Aspirin inhibits platelet lipid peroxidation by permanently acetylating their cyclooxygenase and if the heaviest platelets were the young ones, lipid peroxidation should reappear sooner in them.

Aspirin↗
PubMed1977

Amidolytic assay of thrombin bound to alpha2-macroglobulin in plasma.

A method for the determination in plasma of alpha2-macroglogulin-bound thrombin is described. Alpha2-Macroglobulin-bound thrombin is precipitated from plasma by 13% polyethyleneglycol, and its amidolytic activity is assayed by using the chromogenic substrate benzoyl-Phe-Val-Arg-p-nitroanilide (S 2160). After thrombin addition to plasma, only about 1.7% of the added thrombin activity was recovered in the alpha2-macro-globulin precipitate. It is suggested that the contribution of alpha2-macroglobulin to anti-thrombin activity of normal plasma is of little relevance.

Aniline Compounds↗