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S Coccheri

Publications and source records attributed to S Coccheri.

At least 73 records · Page 4Linked to original sources
PubMed1993

Study of a protein S gene polymorphism at DNA and mRNA level in a family with symptomatic protein S deficiency.

A protein S gene polymorphism, detectable by restriction analysis of amplified exonic sequences, was investigated in a family with members affected by protein S deficiency, deep vein thrombosis and ictus. The clinical laboratory findings as well as RFLP analysis were consistent with the presence of a type WP III protein S deficiency clearly marked by a polymorphic allele, thus enabling us to determine the carrier status in several subjects. The RFLP analysis, extended to platelet mRNA after reverse transcription and amplification, demonstrated that the mRNA produced by the putative defective gene was present in a subject affected by thrombosis.

Adult↗
PubMed1993

Effects of a dried garlic preparation on fibrinolysis and platelet aggregation in healthy subjects.

The acute and chronic effects of a preparation of dried garlic powder (Sapec) in a total daily dose of 900 mg on fibrinolysis and platelet aggregation have been evaluated in a randomized, double-blind, placebo controlled cross-over study of 12 healthy subjects. Total euglobulin fibrinolytic activity and t-PA (tissue plasminogen activator) activity were significantly higher 4 and 6 h after garlic and placebo ingestion, and no differences were recorded between treatments. After 14 days of treatment, t-PA activity was significantly higher after garlic, with inter-treatment significance. No significant changes in PAI (Plasminogen Activator Inhibitor) activity and fibrinogen levels were recorded. Platelet aggregation induced by adenosine diphosphate and collagen, and especially beta-thromboglobulin (beta-TG) release after collagen stimulation were significantly inhibited 2 and 4 h after garlic ingestion; platelet aggregation values were also significantly lower after 7 and 14 days of garlic treatment. No significant changes were found in adenosine triphosphate release and serum TXB2 levels after acute garlic administration.

Adenosine Diphosphate↗
PubMed1992

Double-blind, randomized comparison of systemic continuous infusion of 0.25 versus 0.50 mg/kg/24 h of alteplase over 3 to 7 days for treatment of deep venous thrombosis in heparinized patients: results of the European Thrombolysis with rt-PA in Venous Thrombosis (ETTT) trial.

Thirty-two patients with acute, proximal-vein thrombosis were treated with heparin and alteplase (0.25 versus 0.5 mg/kg/24 h during 3-7 days) in a randomized, double-blind, multicenter, European (ETTT) trial. The treatment resulted in a decrease of the venographic Marder's score from 18 (6-25) to 13 (2-24) units (median, range) in Group I (0.25 mg/kg/24 h, n = 15, median decrease 3.0, p = 0.32) and from 17.5 (3-33) to 15.5 (0-27) in Group II (0.5 mg/kg/24 h, n = 16, median decrease 4.0, p = 0.23). Comparison of the sequential venograms could be performed in 14 cases of Group I and in 15 cases in Group II. A minority of patients showed substantial partial recanalization of the initially obstructed veins on the control venogram (one in each treatment group) and most of the control venograms showed either thrombus size reductions (5 in Group I, 7 in Group II) or no change or even deterioration (8 in Group I, 7 in Group II). Major bleedings were observed in 7 patients (7/32, 22%), 5 of them occurring in Group II (5/17, 29%). Thus, the results of the ETTT trial show that the used low dosages of alteplase administered intravenously over 3-7 days in heparinized patients cannot be recommended as a treatment for patients with deep venous thrombosis of lower limbs and/or pelvis. Further studies are needed to define a more suitable dosage regimen of alteplase in this indication.

Adolescent↗
PubMed1992

An evaluation of several laboratory tests and test combinations in the detection of lupus anticoagulant.

The laboratory assessment of the lupus anticoagulant, a factor frequently associated with venous and arterial thrombosis, recurrent miscarriages and abortions, is not straightforward, as indicated by the variety of tests proposed and the different results obtained. On account of the marked variability and heterogeneity of lupus anticoagulant among patients, no single test or reagent will identify all patients with lupus anticoagulant, and a panel of several tests has to be used. This is time consuming and increases the workload of the laboratory. The aim of this study was to assess the minimum number of tests necessary for the satisfactory identification of the patient with lupus anticoagulant. Our study confirms that lupus anticoagulant may be present in a significant number of patients with normal routine activated partial thromboplastin time, a test which therefore cannot be used as the sole criterion for identifying patients suspected of having lupus anticoagulant. In contrast all patients who had positive results in at least one test could be detected (100% sensitivity) with two combinations of tests: (1) dilute activated partial thromboplastin time and Kaolin clotting time and (2) dilute activated partial thromboplastin time and tissue thromboplastin inhibition test. Since the latter inhibition test has been reported to give a high number of false-positive or negative results, we suggest the combination of dilute activated partial thromboplastin time and Kaolin clotting time as the standard pair of tests for the screening of suspected lupus anticoagulant patients.

Antiphospholipid Syndrome↗
PubMed1991

Ticlopidine.

Explore the source record for details and available documents.

Arterial Occlusive Diseases↗
PubMed1991

Influence of dietary fatty acids on phospholipid composition and prostaglandin E synthesis in rat kidneys.

The effects of oils with different amounts of n6 and n3 fatty acid precursors and derivatives were evaluated on phospholipid composition and PGE2 synthesis of rat kidneys. Dietary lipids were: olive oil, an olive-blackcurrant-fish oil mixture and a blackcurrant-fish oil mixture. We observed in the kidneys of rats fed the blackcurrant-fish oil mixture a significant decrease in PGE2 synthesis, while arachidonate values did not show significant variations. A decrease of PGE2 synthesis could be due to competitive and inhibitory effects of fatty acids other than arachidonate, observed in the kidney phospholipid composition in our dietary conditions.

Animals↗
PubMed1991

Ticlopidine lowers plasma fibrinogen in patients with polycythaemia rubra vera and additional thrombotic risk factors. A double-blind controlled study.

Thirty-seven patients affected by polycythaemia rubra vera (PRV) and with at least one additional thrombotic risk factor (overt vascular disease, diabetes mellitus, treated hypertension, smoking habit, plasma hyperviscosity, hyperfibrinogenemia) were enrolled in a double-blind randomized placebo-controlled study, and 18 were given ticlopidine 250 mg, b.i.d., for 60 days. All the patients had previously been submitted to cytoreduction, and PRV was under control in all cases at the start of the study. During the study, the haematological parameters were controlled every 15 days, and venesection was performed if haematocrit was greater than 46%. Whole blood viscosity, at low and high shear rates, plasma viscosity, and fibrinogen were measured on days 0 and 60. In the ticlopidine group, we recorded a significant 13.14% reduction of the mean fibrinogen level after treatment (390 +/- 63 vs. 449 +/- 97 mg/dl, p less than 0.01). All the other haemorheological parameters were not significantly modified by ticlopidine treatment, nor were there significant modifications recorded in the placebo group. Our study shows that ticlopidine may reduce a probable thrombotic risk factor (hyperfibrinogenemia) in PRV patients.

Aged↗
PubMed1991

Coagulation and fibrinolysis in orthotopic liver transplantation: role of the recipient's disease and use of antithrombin III concentrates. S. Orsola Working Group on Liver Transplantation.

In this study we report the data obtained from extensive haemostatic testing of 25 patients undergoing orthotopic liver transplantation and the results of an open randomized pilot trial of antithrombin III concentrate administration during surgery. Marked differences in transfusional needs and in pre- and intraoperative blood coagulation and fibrinolytic changes were observed between recipients with liver cirrhosis and those with primary biliary cirrhosis. In the former, the increases in tissue-type plasminogen activator activity, total euglobulin fibrinolytic activity, and fibrin-derived degradation products occurred earlier and were more marked, as were the signs of increased thrombin formation. Supplementation of antithrombin III concentrate during surgery failed to induce significant changes in the main parameters studied and in the transfusional needs.

Adult↗
PubMed1991

Modulation of arachidonate metabolite generation in human blood by oral defibrotide.

Acute intravenous administration in man of defibrotide (CAS 83712-60-1), a polynucleotide derivative, induces increase of 6-keto-PGF1 alpha and PGE2 production from appropriately stimulated whole blood. In the present study including acute and chronic experiments, defibrotide (Prociclide) orally administered during two weeks to healthy volunteers significantly increased the amounts of 6-keto-PGF1 alpha generated after appropriate stimulation in whole blood and in a neutrophilic leukocytes-platelet suspension. Similar effects were observed for PGE2, while TXB2 production was unchanged. Furthermore, platelet aggregation induced by calcium ionophore A23817 and production of leukotriene B4 from whole blood and isolated polymorphonuclear neutrophils were inhibited. The observed results suggest that defibrotide is biochemically active also by the oral route although the pharmacological and clinical value of the observed changes needs to be assessed.

Adult↗
PubMed1990

Increased placental production of leukotriene B4 in gestational hypertension.

Production of some lipoxygenase and cyclooxygenase derivatives of arachidonic acid was measured in placental tissue obtained from women with gestational hypertension and with normal pregnancies. The levels of leukotriene B4 were about five times higher in placentas from hypertensive women and also raised thromboxane A2 and reduced prostaglandin E2 levels were observed. Prostacyclin production was lowered only in women with more severe hypertension, in association with the highest measured levels of leukotriene B4 and thromboxane A2. It is suggested that increased placental levels of leukotriene B4 and thromboxane A2 appear already in mild gestational hypertension, while depression of prostacyclin may occur only at more severe stages of gestational hypertensive disease.

Adult↗
PubMed1990

Low molecular weight heparins: an introduction.

Heparin fractions and fragments are useful tools in the elucidation of the mechanism of action of heparin and similar substances. The identification of portions with low or high affinity for antithrombin III and of a 'core' pentasaccharide responsible for anti-factor Xa activity has been possible thanks to heparin fractionation and fragmentation procedures. The development of low molecular weight heparins led to the production of substances with a molecular weight around 5,000, considerably variable in chemical structure, anti-factor Xa and anti-factor IIa activities, and experimental antithrombotic effects. The original rationale according to which fragments with high anti-factor Xa activity and anti-factor Xa/anti-factor IIa ratio would retain optimal antithrombotic activity with greatly reduced prohemorrhagic actions, turned out to be an oversimplification of the problem. In fact, neither is the anti-factor Xa activity the only determinant of the antithrombotic effect, nor is the anti-factor IIa activity a good predictor of hemorrhage. Despite disaggregation of the original rationale, low molecular weight heparins have already proved to be at least as effective and safe, and more conveniently and practically administered, as unfractionated heparin in the prophylaxis of deep-vein thrombosis.

Animals↗
PubMed1989

Association of reduced factor VIII with impaired platelet reactivity to adrenalin and collagen after total thyroidectomy.

Twenty-one thyroprival patients, previously submitted to total thyroidectomy for tumours, were investigated during stabilized L-thyroxine supplementation and at the end of a 20-25 day "no-therapy" period, necessary for a 131I total body scintigraphy. During supplementation therapy a lower than normal mean beta-thromboglobulin (beta-TG) release level was found, the other blood clotting and platelet function tests being normal. After substitution therapy withdrawal, platelet function tests showed reduced adrenalin aggregation, increased collagen threshold aggregating concentrations, decreased beta-TG release values and reduced aggregation to ristocetin, whereas blood clotting tests showed prolonged aPTT values and reduced levels of factor VIII:C and vWf:Ag. We conclude that in acquired hypothyroidism the lowering of factor VIII:C and vWf:Ag (acquired von Willebrand disease) is associated with impaired platelet reactivity not only to ristocetin but also to collagen and especially adrenalin. In the patients investigated these changes were almost completely corrected by substitutive therapy with L-thyroxine at clinically effective doses.

Adult↗
PubMed1989

Lowered antithrombin III activity and other clotting changes in homocystinuria: effects of a pyridoxine-folate regimen.

Few studies have dealt with blood-clotting changes in patients affected by homocystinuria. The aim of this contribution is to briefly review studies published so far on the topic and report the results of our investigation performed in 3 patients. At baseline we found reduced antithrombin III and factor VII levels in all the patients, in line with the results of other authors, and other slight and less constant changes such as lowered factor X activity and protein C antigen, and increased beta-thromboglobulin levels. During pyridoxine and folate treatment, antithrombin III activity rapidly returned to normal; factor VII increased and beta-thromboglobulin decreased. These blood-clotting abnormalities may play a role in the thrombotic tendency associated with homocystinuria. Their nature is still uncertain, but the improvement observed during active metabolic treatment suggests that the defect in amino acid transsulfuration of homocystinuria may directly affect synthesis or activity of some clotting factors.

Adolescent↗
PubMed1989

Ticlopidine in the treatment of intermittent claudication: a 21-month double-blind trial.

After a 3-month, single-blind, run-in period, 151 patients with intermittent claudication were randomly allocated to receive the antiplatelet agent ticlopidine (250 mg twice per day) or an identical placebo. One hundred and twenty patients completed the double-blind phase of the trial, which lasted 21 months. The primary analysis was performed according to the "intention-to-treat principle" in all 151 enrolled patients. There was, continuing on from the third month after randomization, a progressive and sustained improvement of the pain-free and maximum walking distances in the two treatment groups that was significantly greater in the ticlopidine group. The ankle-arm systolic blood pressure ratio at rest and after exercise increased in a significant manner in the ticlopidine group only. In a secondary analysis, with exclusion of 25 patients because of protocol violations at selection, consistently significant differences in favor of the ticlopidine group were still observed for maximum walking distance and systolic ankle-arm blood pressure ratio, both at rest and after exercise. No major side effects were reported in the treated group. It is concluded that long-term treatment with ticlopidine improves walking ability and ankle systolic blood pressure in patients with claudication.

Blood Pressure↗
PubMed1988

Long-term effects of ticlopidine on fibrinogen and haemorheology in patients with peripheral arterial disease.

The effects of ticlopidine treatment (250 mg b.i.d. for 21 months) on fibrinogen and other rheological variables, as compared to placebo, were studied in 44 patients with intermittent claudication due to peripheral arterial occlusive disease. Blood samples were collected every 3 months during this double-blind, randomised placebo-controlled trial which lasted 21 months. Consistently lower values of fibrinogen, haematocrit and whole blood viscosity at high and low shear rate levels were found in the ticlopidine group; the intergroup differences were statistically significant at most but not all follow-up examinations. A significant time-related variance was observed in the ticlopidine group for the measured variables, also after correction for the variability found in the placebo group. Thus, the observed changes in the ticlopidine group are mainly treatment related. These effects on fibrinogen and haemorheology may contribute, besides the known antiplatelet activity of the drug, to the clinical improvement reported in a larger group of claudicants to which the present subset of patients belong.

Blood Viscosity↗
PubMed1988

Acute effects of defibrotide, an experimental antithrombotic agent, on fibrinolysis and blood prostanoids in man.

Defibrotide is a polynucleotide extracted from mammalian lung, which shows antithrombotic and anti-ischaemic activity in animals, probably related to stimulation of fibrinolysis and/or enhancement of prostacyclin production. The effect of a single infusion of defibrotide on fibrinolysis and the levels of certain prostanoids in man has been investigated in a cross-over double-blind placebo-controlled study. Evaluation of changes in fibrinolysis was difficult because of the spontaneous activation observed after placebo. However, the fast-acting plasminogen activator inhibitor was decreased only at end of the defibrotide infusion, suggesting a moderate profibrinolytic effect superimposed on the spontaneous activation. There was a marked and prolonged elevation of the plasma level of 6-keto-PGF1 alpha, the stable metabolite of prostacyclin. In collagen stimulated whole blood, both 6-keto-PGF1 alpha and prostaglandin E2 production were also greatly increased, with no consistent indication of inhibition of thromboxane B2. It is suggested that defibrotide stimulates prostacyclin and prostaglandin E2 production by leucocytes or via platelet/leukocyte interactions. The effects observed here should be useful in guiding subsequent clinical trials.

6-Ketoprostaglandin F1 alpha↗