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Biomedical subjects

A Girolami

Publications and source records attributed to A Girolami.

At least 361 records · Page 20Linked to original sources
PubMed1988

Low incidence of familial occurrence of thrombocythaemia and/or thrombocytosis.

Several reports have been published about familial polycythaemia vera (PV) but no information is available about the incidence of thrombocytosis in the same family. In our population of thrombocytosic patients, both with primary thrombocytosis (133 cases) and secondary (37 cases), we found only two family related subjects. One of them had PV and the other essential thrombocytosis (ET). Our results seem to indicate that familial thrombocytosis is a rare phenomenon, much less frequent then familial thrombocytopenia.

Adolescent↗
PubMed1988

Increased proportion of giant platelets and platelet distribution width are better indicators of altered platelet homeostasis than mean platelet volume in liver cirrhosis.

Platelet count, mean platelet volume (MPV), giant platelet percentage, expressed by us as megathrombocytic index (MTI) and platelet distribution width (PDW) have been evaluated in 32 control subjects and in 27 patients suffering from liver cirrhosis (LC) and thrombocytopenia. MTI and PDW were linearly and inversely correlated to platelet count both in controls and patients. MTI and PDW were markedly increased in LC as compared to controls, while MPV was not significantly different. It is concluded that MTI and PDW are good indices of thrombopoietic stimulus both in controls and in CL and better indicators of altered platelet homeostasis than MPV in LC.

Adolescent↗
PubMed1988

The prevalence of AIDS, AIDS related complex and HIV seropositivity in a large population of patients with congenital clotting disorders.

We have investigated up to the beginning of 1987 114 patients with congenital clotting disorders. 84 had received plasma and/or clotting factors concentrates. 18 out of 84 (21%) had leukopenia, thrombocytopenia, or both. 64 out of 84 (76%) had been infected by hepatitis B virus. The great majority of them (62 out 64) developed adequate immunity (anti Hbs antibodies). Despite this, 47 out 84 (57%) showed persistently elevated transaminases. 17 out of 84 (20%) had HIV-seropositivity. Among them, 7 are free of symptoms related to such a virus up to present time, 8 developed AIDS-related complex and 2 had the full-blown AIDS and died. Non significant difference in HIV seroconversion or its clinical manifestations was noted depending on the administration of factor VIII concentrates versus prothrombin complex concentrates. In contrast, plasma administration appeared to be associated with a lower risk of viral transmission. No abnormality was observed in patients who had never received haemoderivatives, except the presence of anti Hbs antibodies in 1 of them.

AIDS-Related Complex↗
PubMed1988

The report of an Italian family with heterozygous protein C deficiency.

A heterozygote protein C deficit was found in 4 members of the same family. The propositus is a 40 year old male with a clear thrombotic tendency. This included repeated thrombophlebitis of the right leg, and one episode of pulmonary embolism. Arterial thrombosis was not noted. The anticoagulant therapy undertaken by the patient appears to be of some benefit in the sense that no recurrence of thrombotic manifestations occurred. One brother and two nephews of the propositus, even though asymptomatic showed reduced levels of Protein C both as activity and antigen. The parallel reduction of Protein C activity and antigen points towards a "true" deficit of Protein C. The normal, although reduced, pattern in the crossed immunoelectrophoresis supplies further confirmation to this interpretation.

Adult↗
PubMed1988

The use of antiproteolytic mixture fails to modify the abnormal von Willebrand factor pattern in myeloproliferative disease.

Abnormalities of von Willebrand factor, with reduction of higher molecular weight multimers, was described in patients with increased platelet number. We have studied twelve patients with myeloproliferative disease (9 patients with Essential Thrombocytosis and 3 patients with Polycythemia Vera). Blood samples were collected either with citrate and antiproteolytic mixture (EDTA 6 mM, Aprotinin 200 U/ml, N-ethylmaleimide 5 mM in sodium citrate 3.8%). VIIIR: RCoF was found decreased in all patients studied, using both anticoagulants, while VIIIR: Ag was within normal range. Higher molecular weight multimers were found decreased or absent both in samples collected with citrate and in those collected using the antiproteolytic mixture. These data suggested that von Willebrand factor abnormalities observed in myeloproliferative disease are not due to a proteolytic degradation that's supposed to happen in vitro during blood samples collection and manipulation.

Anticoagulants↗
PubMed1987

Multicenter evaluation of a chromogenic substrate method for photometric determination of prothrombin time.

A multicenter study of a chromogenic substrate method for photometric determination of prothrombin time was conducted in order to evaluate its clinical application. Seven laboratories participated in the study using a total of 742 plasma samples from 417 patients on oral anticoagulant therapy, 261 healthy subjects and 64 patients with different diseases especially of the liver as well as 30 patients with hereditary deficiency of coagulation factors II, V, VII, X. The chromogenic PT method was compared to a standardized coagulometric PT assay which uses the same sensitive human placenta thromboplastin calibrated against international reference preparations. A high correlation of the prothrombin ratio values of the chromogenic and the coagulometric assay was obtained in 402 plasma samples (r = 0.940; y = 1.02x - 0.1). The study showed that the chromogenic PT reagent is sensitive to deficiency of the coagulation factors of the extrinsic pathway but not affected by heparin up to 1 IU/ml because of the heparin antagonist added. The precision (coefficient of variation) of the photometric method ranged between 0.6 and 3% (intraassay CV) and between 1.4 and 5.8 (interassay CV). The International Sensitivity Index (ISI) obtained for the used lot was 1.09. The therapeutical range in percentage activity for patients in a stable phase of an anticoagulant therapy was found to be from 15 to 27 percent of normal. The results of the clinical evaluation proved the good comparability of the new chromogenic PT test with coagulometric methods, its high factor sensitivity, good reproducibility and easy performance.

Anticoagulants↗
PubMed1987

Increased factor VIII/vWf levels in patients with reduced platelet number.

Factor VIII/von Willebrand factor (VIII/vWf) related properties were studied in twenty six patients with thrombocytopenia. Fifteen patients were affected by idiopathic thrombocytopenic purpura (ITP) and 11 patients by thrombocytopenia of a different nature or non-ITP (n-ITP). All patients showed an enhancement of platelet associated IgG (PAIgG). A significant increase of factor VIII ristocetin cofactor (VIII R: RCoF) and factor VIII related antigen (VIII R:Ag) was found in ITP patients while normal values were observed for factor VIII coagulant (VIII:C). All factor VIII/vWf components, on the contrary, were increased in n-ITP group with a prevalence of VIII R:RCoF as observed in ITP group even though with lower mean values. Multimeric analysis of VIII/vWf demonstrated a higher concentration of all multimeric components, with major representation of higher molecular weight multimers (HMWM) in patients of both groups. Two patients were studied before and after improvement in platelet count. A decrease of vWf related properties (VIII R:RCoF and VIII R:Ag) concomitant with the increase in platelet count was found. In n-ITP patients a statistical correlation between VIII R:RCoF and PAIgG was also observed while no correlation was found between other factor VIII/vWf components and PAIgG both in ITP and n-ITP patients.

Adolescent↗
PubMed1987

The significance of thrombocytosis in old age.

We performed a retrospective study on 21 patients, aged 70 years or more, affected by polycythemia vera (PV) or essential thrombocythemia (ET). As controls, we evaluated 10 younger ET patients. The results indicate that in older ET subjects there was a lower incidence of hemorrhagic and thrombotic complications than in younger patients and PV patients. However, platelet number and platelet function tests were similar in all the patients studied. We suppose that an increase in hematocrit as seen in PV is much more dangerous as compared to an isolated increase in platelet count, and that thrombocytosis alone in old age can be an isolated expression of a natural involution of blood marrow similar to myelofibrosis.

Adult↗
PubMed1987

Failure of two anti-platelet drugs (indobufen and dipyridamole) to improve thrombocytopenia in liver cirrhosis.

The hypothesis that thrombocytopenia in liver cirrhosis (LC) could be due to platelet activation was investigated. 18 patients with thrombocytopenia and LC have been studied. Circulating beta-thromboglobulin (beta TG) was normal, but appeared elevated when referred to platelet count. However, this may not accurately reflect alpha-granule release because of reduced liver cell function. Intraplatelet beta TG, on the contrary, should not be affected by liver cell function. It was markedly depressed, thus truly suggesting the existence of an exhausted state caused by platelet activation. Thromboxane B2 production was slightly increased. This could be due to a compensatory mechanism, or simply to platelet size, which was slightly increased, too. Anti-platelet therapy failed to improve thrombocytopenia. A platelet activation state seems therefore to be present in LC, but seems not to be the only cause of thrombocytopenia. Platelet factor 4 approximated zero, regardless of platelet count and therapy. This confirms that elevated values of such a protein represent only a laboratory artifact, due to platelet activation in vitro.

Aged↗
PubMed1987

Fibrinolytic behavior in long-standing branch retinal vein occlusion.

The aim of our study was to evaluate the fibrinolytic system in patients with retinal branch vein occlusion (RVO). The following tests were carried out: prothrombin time, partial thromboplastin time (PTT), fibrinogen degradation products, euglobulin lysis time, fibrinogen, pasminogen, antithrombin III, alpha 2-antiplasmin and alpha 2-macroglobulin. Comparing the results of patients with those of normal controls, only the fibrinogen increase and PTT shortening were significantly different. All other tests taken into account were within normal limits. Only the patients without other associated diseases (diabetes or hypertension) showed a significant activation of fibrinolysis (either with respect to normal or to other RVO patient groups). In conclusion, no important fibrinolytic impairment was seen in our longstanding RVO patients. Fibrinolytic activation seen in patients without verified associated diseases may be related to the presence of a sound endothelium, still able to release plasminogen activators in response to RVO. The fibrinogen and PTT changes in RVO were probably due to other associated diseases.

Aged↗
PubMed1987

Type IIB von Willebrand factor with normal sialic acid content induces platelet aggregation in the absence of ristocetin. Role of platelet activation, fibrinogen, and two distinct membrane receptors.

Three preparations of purified von Willebrand factor (vWF), obtained from unrelated patients affected by type IIB von Willebrand disease, were found to have normal sialic acid content (between 129 and 170 nmol/mg of vWF, as compared with 158 +/- 17 nmol/mg in four normal preparations) and to induce platelet aggregation in the presence of physiologic levels of divalent cations and without addition of ristocetin. A monoclonal antibody that blocks the vWF binding domain of the platelet glycoprotein (GP)Ib caused complete inhibition of IIB vWF-induced aggregation. In contrast, a monoclonal antibody that blocks the receptor for adhesive proteins on the platelet GPIIb/IIIa complex failed to inhibit the initial response of platelets to high concentrations of IIB vWF. Moreover, IIB vWF caused agglutination of formalin-fixed platelets that was blocked only by the anti-GPIb antibody, suggesting that the binding of vWF to GPIb, even in the absence of ristocetin, results in platelet-platelet interaction that is followed by exposure of the GPIIb/IIIa receptors for adhesive proteins. Endogenous ADP, normally active platelet metabolism and fibrinogen binding to GPIIb/IIIa were necessary for maximal and irreversible platelet aggregation. In the absence of fibrinogen, however, aggregation was mediated by vWF binding to GPIIb/IIIa. A 52/48-kD tryptic fragment containing the GPIb binding domain of normal vWF completely blocked the aggregation induced by all three IIB vWF preparations. The present study defines in detail the mechanisms involved in IIB vWF-induced platelet aggregation. Moreover, it establishes that the GPIb binding domain of normal and IIB vWF are closely related and that desialylation is not required for the direct interaction of IIB vWF with GPIb.

Apyrase↗
PubMed1987

Factor X antigen--factor X activity discrepancy in coumarin treated patients. No relationship with dilution curve.

The plasma of 12 patients on coumarin medication was investigated with regard to factor X antigen, factor X activity, factor X antigen--factor X activity difference (delta) and dilution curve. The plasmas were divided into 3 groups according to the level of anticoagulation (under anticoagulated, normally anticoagulated, over anticoagulated). The average factor X antigen and the average factor X activity were 56.7, 53.0, 34.6 and 25.5, 20.1, 11.1%, respectively for the three groups of patients. The antigen-activity differences (delta) were 21.2, 22.5 and 23.5%, respectively. The degree of inhibition in conventional units was 2.6, 1.7 and 0.4 units for the three groups of patients, respectively. The decrease of "inhibition" with the increase of anticoagulation is not in agreement with the presence of similar levels of pre-factors or delta antigen-activity in the plasma of the three groups of patients. These data are against the presence of inhibitors in coumarin treated patients.

Antigens↗
PubMed1987

Thrombocytopenia in liver cirrhosis complicated by variceal haemorrhage: lack of increase in platelet count after spleno renal distal shunt.

10 patients with liver cirrhosis (LC) and previous variceal bleeding have been studied. Platelet count was markedly depressed. Giant platelet percentage (MTI) was significantly increased, reflecting bone marrow compensatory hyperactivity. Platelet associated IgG (PAIgG) was elevated. Such elevation, however, was inconstant and did not correlate with platelet count. Beta-thromboglobulin was markedly increased when referred to circulating platelet number, but its level did not accurately reflect platelet activation, because of decreased liver cell function. Platelet Factor 4 was always zero, thus confirming that high values of this protein represent only a laboratory artifact, due to platelet activation in vitro. 5 patients underwent spleno renal distal shunt, which transiently improved hypersplenism only in one case. Despite this, MTI became perfectly normal in all patients, suggesting a decrease in the thrombopoietic stimulus. PAIgG dramatically fell in the two patients with the highest pre-operative values. Since thrombocytopenia persisted, the non-specific nature of PAIgG in LC seems to be further supported.

Adult↗