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Biomedical subjects

G Davì

Publications and source records attributed to G Davì.

At least 91 records · Page 5Linked to original sources

[Evaluation of blood viscosity and erythrocyte filterability in chronic ischemic heart disease].

In 40 patients suffering from chronic ischemic heart disease (16 with history of myocardial infarction, 10 with unstable angina and 14 with stable angina) and in an equal number of sex-and age-matched control subjects, we have determined plasma and blood viscosity according to RAND et al. using a Wells-Brookfield Micro-Viscometer, shear rate 230 sec-1, and red cell filterability according to REID et al. Significant differences were found in patients suffering from ischemic heart disease, in comparison with the control group, for blood viscosity (p less than 0.01), plasma viscosity (p less than 0.001) and red cell filterability (p less than 0.001). The changes of hemorheological parameters in ischemic heart disease, especially in patients suffering from unstable angina and in those with history of myocardial infarction, point to the opportunity of a pharmacological treatment aiming at improving the district microcirculation.

Adult↗

Platelet thromboxane synthesis in treated childhood diabetes mellitus.

TXB2 formation in PRP after thrombin or arachidonic acid stimulation was determined in 23 young compensated insulin-dependent diabetic patients, and in 10 control subjects of equivalent age. No significant difference in TXB2 synthesis during the times sampled was observed. Six out of 23 diabetics had circulating immune complexes (CIC) in their sera as detected by the C1q-SP; after the addition of arachidonic acid and thrombin the amount of TXB2 in PRP from CIC-positive patients was significantly higher than in PRP from CIC-negative patients. The increased synthesis of PG endoperoxides in CIC-positive patients could be a direct effect of antigen-antibody complexes on platelets.

Adolescent↗

The effect of two low doses of aspirin on whole blood thromboxane and prostacyclin generation in healthy subjects.

The effects of two low doses of aspirin (20 mg and 100 mg) on prostacyclin and thromboxane formation during whole blood clotting were studied in 8 healthy volunteers. A single 100 mg aspirin dose caused more than 90% reduction of both serum TXB2 and 6-keto-PGF1 alpha; a single 20 mg dose of aspirin inhibited serum TXB2 more than 6-keto-PGF1 alpha but effects on these two products could not be completely dissociated. However, the effect of a single 20 mg aspirin dose on serum TXB2, was of much longer duration than its inhibitory effect on PGI2 synthesis during whole blood clotting.

6-Ketoprostaglandin F1 alpha↗

Plasmatic TXB2 and 6-keto-PGF1 alpha levels during charcoal hemoperfusion in chronic renal failure patients.

6 patients with end-stage renal disease underwent hemoperfusion with charcoal columns, for 60 min. Blood samples anticoagulated with 2% EDTA/aspirin solution were obtained from arteriovenous fistulas in the basal condition, 5 min after a bolus injection of heparin (7,500 U), at the end of hemoperfusion, and 30 min after. The study was repeated few days later, in the same patients, two hours after 100 mg aspirin by mouth. TXB2 and 6-keto-PGF1 alpha were assayed with RIA in unextracted (U) and extracted (E) and chromatographed platelet poor plasma (PPP). Platelet counts before and after hemoperfusion were also performed. Low levels of the two prostaglandins were found in plasma; this could be related to the procedures for collection and processing of plasma samples; no significant differences were observed between extracted and unextracted samples: there were slightly higher levels of 6-keto-PGF1 alpha in unextracted samples. After charcoal hemoperfusion there was only a slight and not significant increase of TXB2 and 6-keto-PGF1 alpha; low dose aspirin did not modify significantly plasma levels of the two prostaglandins before hemoperfusion but it reduced TXB2 and 6-keto-PGF1 alpha levels after charcoal hemoperfusion. The platelet count fell (-22%) after charcoal hemoperfusion with heparin alone and in similar manner after low-dose aspirin pretreatment (-24%, 7%).

6-Ketoprostaglandin F1 alpha↗

[Behavior of various blood coagulation and hemorrheological parameters in arteriosclerotic vascular disease of the lower legs].

Red blood cell filterability was compared with some blood coagulation parameters in 50 patients suffering from atherosclerosis obliterans of lower limbs at stages II, III and IV. The reduced red blood cell filterability correlated positively with the stage of the arterial disease (r = 0.8185), with levels of plasma fibrinogen (r = 0.8366) and with the euglobulin lysis time (r = 0.8124), while negative correlations with platelet reactivity threshold (r = 0.6928) and with antithrombin III activity (r = 0.6557) were found. The authors believe that in the therapy of these vascular diseases it is necessary to modify the reduced red blood cell filterability together with the blood coagulation order.

Antithrombin III↗

Platelet sensitivity to prostacyclin and thromboxane production in hyperlipidemic patients.

In 13 type II hyperlipidemics (10 males and 3 females; mean age 50.2 +/- 10.6 years), in 10 type IV hyperlipidemics (7 males and 3 females; mean age 51 +/- 13.3 years) and in 23 healthy age- and sex-matched controls, the following parameters were measured: plasma cholesterol; plasma TG; plasma C-HDL; VLDL, separated in a preparative ultracentrifuge; C-LDL; Apo B, with immunoelectrophoretic method; platelet sensitivity to prostacyclin; TXB2 formation in PRP; TXB2 in serum. This study provides evidence for: 1. Reduced platelet sensitivity to prostacyclin, more evident in type II hyperlipidemia that provides an additional mechanism involved in increased platelet aggregation found in type II hyperlipidemia. 2. Enhanced TXB2 formation in PRP after thrombin stimulation (664.65 +/- 142.18 pmol/10(8) platelets) only in type II hyperlipidemics and such enhanced formation was positively correlated to C-LDL (r = 0.53; p less than 0.05) and to Apo B (r = 0.62; p less than 0.05); serum TXB2 formation rate was also increased in type II hyperlipidemia.

Adult↗

Thromboxane B2 formation and platelet sensitivity to prostacyclin in insulin-dependent and insulin-independent diabetics.

TxB2 formation in PRP after thrombin stimulus, serum TxB2 and platelet sensitivity to prostacyclin and the correlation with ambient fasting plasma glucose and lipoproteins were determined in 20 insulin-independent diabetics (IID) with macroangiopathy, 10 insulin-dependent diabetics (IDD) with microangiopathy and 30 matched controls. Platelets obtained from insulin-independent diabetics synthetize significantly higher amounts of TxB2 than those of insulin-dependent diabetics and matched controls. IDD and IID patients required significantly higher concentrations of prostacyclin (p less than 0.001) for a similar degree of platelet aggregation inhibition. The amount of prostacyclin required for 50% platelet aggregation inhibition was correlated with fasting plasma glucose (r = 0.64, p less than 0.001) and HbA1% (r = 0.48, p less than 0.01) in all diabetic subjects. We conclude that: 1) only PRP, obtained from some insulin-independent diabetics with a concomitant macroangiopathy, shows an increased synthesis of TxB2; 2) platelet sensitivity to prostacyclin is highly dependent on the fasting ambient plasma glucose.

Adult↗

Enhanced platelet release reaction in insulin-dependent and insulin-independent diabetic patients.

Plasma beta thromboglobulin (BTG) and platelet factor 4 (PF4) levels were measured and correlated with plasma lipid and lipoprotein patterns in 20 insulin-independent diabetics, in 10 insulin-dependent diabetics and in 30 healthy controls matched to patients as to age, sex and weight. Increased plasma BTG and PF4 levels both in insulin-dependent and in insulin-independent diabetics indicate enhanced in vivo platelet activation and release reaction in these patients. No difference in BTG and PF4 values between these two groups of diabetic patients was observed in our study. A marked correlation between plasma PF4 values and plasma glucose levels was shown in insulin-dependent diabetics only whereas a significant positive correlation with plasma triglycerides and plasma triglyceride VLDL and a negative correlation with cholesterol-HDL was shown in insulin-independent diabetics.

Adult↗