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Biomedical subjects

D Prisco

Publications and source records attributed to D Prisco.

At least 127 records · Page 7Linked to original sources

Effect of oral treatment with pantethine on platelet and plasma phospholipids in IIa hyperlipoproteinemia.

In a single-blind, crossover, completely randomized study, the effects of oral treatment with pantethine or placebo on fatty acid composition of plasma and platelet phospholipids were investigated in 10 IIa hyperlipoproteinemic patients. A significant decrease of total cholesterol and total phospholipids was observed both in plasma and in platelets after a twenty-eight-day treatment. In plasma, pantethine induced a decrease of the ratio sphingomyelin/phosphatidylcholine. Moreover, a relative increase of n3-polyunsaturated fatty acids both in plasma and in platelet phospholipids and a decrease of arachidonic acid in plasma phospholipids were observed. These results indicate that pantethine can affect plasma and platelet lipid composition with possibly favorable influences on the determinants of cell membrane fluidity.

Administration, Oral↗

Age related changes in platelet lipid composition.

Platelet lipid composition was investigated in 52 healthy subjects aged 20 to 68 years with similar dietary habits and living in a narrow geographic area in order to search possible changes referrable to aging. No significant variations were observed when platelet cholesterol, total phospholipids and different phospholipid fractions were considered, whereas cholesterol/phospholipid (C/PL) molar ratio significantly increased with aging (p less than 0.01). Moreover, a significant increase in 16:0 + 16:1 fatty acids was found in phosphatidylcholine (PC) and in sphingomyelin (SP) (r = 0.62, p less than 0.001 and r = 0.30, p less than 0.05 respectively) and a decrease in 18:2 n6 in the phospholipid fractions considered (at least p less than 0.05). These results indicate that modifications in platelet lipid composition occur with aging and that they could affect platelet functions so playing a role in the onset of atherosclerosis and in thrombotic phenomena occurring with increasing frequency in the elderly.

Adult↗

Increased thromboxane A2 generation and altered membrane fatty acid composition in platelets from patients with active angina pectoris.

Lipid composition of platelet membranes and thromboxane A2 (TxA2) generation by platelets were investigated in eighty-seven anginal patients (forty-two with resting angina in active phase and forty-five with effort stable angina or rest angina in inactive phase) and in forty-five clinically healthy subjects of similar age. All subjects were on the same dietary regimen and the adherence to diet was checked by analysis of red blood cell lipids. Platelets from active angina patients produced more TxA2 than platelets from both inactive patients and controls (p less than 0.001). Moreover patients with active angina had higher arachidonic acid (AA, p less than 0.001) and lower eicosapentaenoic (EPA) and docosahexaenoic acid (DHA) levels in phosphatidylcholine (PC, p less than 0.001), than inactive patients and controls. AA and EPA changes in membrane PC significantly correlated with TxA2 production (p less than 0.001) but not with coronary pathoanatomy. Plasma lipids, content of cholesterol, total phospholipids (and their saturated and unsaturated fatty acids) and the different phospholipid fractions in platelet membrane were not different in the three groups. Present results indicate that in platelets from anginal patients phospholipid fatty acid composition is at least in part independent of plasma composition and that in active angina there are modifications leading to increased TxA2 formation and possibly contributing to the occurrence of ischemic attacks.

Adult↗

Impaired cardiac PGI2 and PGE2 biosynthesis in patients with angina pectoris.

Thirty-four patients with unstable angina and 14 patients with stable effort angina were investigated for cardiac prostacyclin and prostaglandin E2 (PGE2) biosynthesis, under resting conditions and after cold pressor testing. Twenty-seven patients undergoing cardiac catheterization and coronary angiography for congenital or acquired heart diseases other than coronary artery disease were studied as a control group. Prostacyclin (as 6-keto-PGF1 alpha) and PGE2 were measured by specific radioimmunoassay of blood from the coronary sinus and aorta. During resting conditions no significant differences in plasma 6-keto-PGF1 alpha and PGE2 concentrations were found between coronary sinus and aortic blood, and no transcardiac gradient existed either in control subjects or in patients with stable and unstable angina, respectively. In control subjects cold pressor testing induced a significant increase in 6-keto-PGF1 alpha and PGE2 levels in blood from the different sampling sites, and a significant transcardiac gradient occurred (+11.2 +/- 6.4 pg/ml for 6-keto-PGF1 alpha and +5.1 +/- 3.4 pg/ml for PGE2). However, in angina patients no significant increase in 6-keto-PGF1 alpha and PGE2 plasma levels was found and no transcardiac gradient was formed after cold pressor testing. These results indicate impaired cardiac prostacyclin and PGE2 biosynthesis both in patients with stable and unstable effort angina.

6-Ketoprostaglandin F1 alpha↗

Factors influencing platelet aggregation in whole blood.

In order to evaluate the interference of blood cells on platelet aggregation, spontaneous platelet aggregation (SPA), ADP, and collagen-induced platelet aggregation were investigated in whole blood by the impedance method and in platelet-rich plasma (PRP) by densitometric and impedance aggregometers. Stirring of the sample induced a significant decrease of neutrophils (P less than 0.001) but no changes of red blood cell (RBC) and platelet count. After collagen addition, a further decrease of neutrophils was observed, while RBC count was unmodified. The occurrence of SPA was not different in whole blood and in PRP. Platelet number and hematocrit did not affect either spontaneous or collagen-induced aggregation. A significant linear relation (r = -0.60, P less than 0.01) between neutrophil count and collagen whole blood platelet aggregation was found. Collagen- and ADP-induced aggregation were significantly higher and lower, respectively, in whole blood than in PRP using the densitometric method. No differences were observed in SPA and collagen platelet aggregation according to age and sex.

Adult↗

Enhanced peripheral vasoconstrictor response and increased thromboxane A2 synthesis after the cold pressor test in patients with angina at rest.

Peripheral vascular resistance (PVR) and thromboxane A2(TxA2) synthesis after the cold pressor test were investigated in different subsets of patients with angina (10 with stable effort angina, 36 with resting angina [24 in an active phase and 12 in an inactive phase], and five with Prinzmetal's variant angina) and in 41 control subjects of equivalent age and risk factors. Left ventricular end-diastolic pressure, ejection fraction, extent of coronary angiographic lesions, and baseline PVR were not significantly different among the various patient groups. In all patient groups, except those with variant angina, the cold pressor test resulted in a higher increase in PVR than in the control subjects (p less than .001 for all groups). In patients with variant angina the vasoconstrictor response was increased only in proximity (about 1 hr) to ischemic attacks. In patients with active resting angina the vasoconstrictor response was on the average four times longer than that in patients with effort angina and with inactive resting angina (p less than .001). This exaggerated vasoconstrictor response was associated with elevated TxA2 resting levels in plasma and with increased TxA2 synthesis after the cold pressor test. A linear relationship was found between the area of the vascular response and the area of TxA2 production after the cold pressor test in patients with active resting angina (r = .87, p less than .001). The increased TxA2 synthesis and the inappropriate increase of peripheral vascular response to sympathetic stimulation revert back to normal in the inactive phase.(ABSTRACT TRUNCATED AT 250 WORDS)

Angina Pectoris↗

Spontaneous and cold pressor test-induced prostaglandin biosynthesis by human heart.

To investigate prostaglandin biosynthesis by the heart, 21 patients undergoing cardiac catheterization and coronary angiography for congenital or acquired heart diseases other than coronary artery disease were investigated. Prostacyclin (as 6-keto-PGF1 alpha), PGE2, PGF2 alpha and TxA2 (as TxB2) were measured by specific radioimmunoassay in blood from coronary sinus, aorta, and a peripheral vein under resting conditions and following cold pressor test (CPT). PGF2 alpha was always found undetectable. In resting conditions, no significant differences in plasma 6-keto-PGF1 alpha, PGE2, or TxB2 concentrations were found among coronary sinus, aorta, and peripheral venous blood and no transcardiac gradient existed (mean: +0.4 +/- 1.2 pg/ml for 6-keto-PGF1 alpha, +0.1 +/- 0.6 pg/ml for PGE2, and -0.4 +/- 9.9 pg/ml for TxB2). CPT was able to induce a significant increase in 6-keto-PGF1 alpha and PGE2 concentration in blood from the different sampling sites and a significant transcardiac gradient was found following CPT (+11.6 +/- 7.4 pg/ml for 6-keto-PGF1 alpha (p less than 0.01) and +5.2 +/- 3.6 pg/ml for PGE2 (p less than 0.001). TxB2 levels significantly increased in peripheral venous blood (from 18.3 +/- 6.2 to 29.2 +/- 20.3 pg/ml, p less than 0.05), but they did not increase either in coronary sinus (from 21.9 +/- 9.7 to 22.9 +/- 9.8 pg/ml) or in aorta (from 22.3 +/- 4.7 to 19.1 +/- 6.5 pg/ml). Present results indicate that a cardiocoronary prostacyclin and PGE2 synthesis is inappreciable under resting conditions but it becomes remarkable following sympathetic stimulation. On the contrary, no TxA2 cardiocoronary biosynthesis seems to occur in patients free from coronary artery disease.

Adult↗

Abnormal cardiocoronary thromboxane A2 production in patients with unstable angina.

Thromboxane B2 (TXB2), the stable metabolite of thromboxane A2 (TXA2), was measured in the coronary sinus and in aortic blood before and after cold pressor test (CPT) in 21 patients suffering from ischemic heart disease (7 affected by stable effort angina and 14 by unstable angina) and in 12 patients not suffering from myocardial ischemia (control group) during coronary angiography. Aspirin (10 mg/kg intravenously) was administered before catheterization in order to prevent platelet and leukocyte TXA2 formation. Control subjects and patients with effort angina had TXB2 resting levels lower than unstable angina patients without a transcardiac gradient which, on the contrary, was found in unstable angina patients. Only in these patients CPT resulted in a significant TXB2 increase more marked in the coronary sinus (from 50.0 +/- 18.9 pg/ml to 73.0 +/- 35.1 pg/ml, p less than 0.001) than in the aorta (from 33.4 +/- 17.1 pg/ml to 42.6 +/- 24.0 pg/ml, p less than 0.05), so that the transcardiac TXB2 gradient significantly increased. In all but two unstable angina patients, TXB2 elevation was not associated with a fall of cardiac lactate extraction. The resting and CPT-induced TXB2 gradients were unrelated to the presence and severity of coronary angiographic lesions. These results indicate that unstable angina patients show an abnormal cardiocoronary capacity to synthesize TXA2, which seems not to be elicited by the occurrence of myocardial ischemia.

Adult↗

Changes in fatty acid composition of the single platelet phospholipids induced by pantethine treatment.

In a single-blind cross-over study the effect of oral treatment with pantethine on plasma and platelet lipid composition was evaluated in 20 patients with dyslipidaemia (7 IIa, 7 IIb and 6 Iv type). In plasma significant decreases of total cholesterol and triglycerides with increase of high density lipoprotein-cholesterol were observed. In platelets pantethine treatment significantly reduced phospholipid and cholesterol content. In addition gas-chromatographic analysis showed a reduction of saturated and monounsaturated and a relative increase of polyunsaturated fatty acid content of platelet phospholipids. A selective relative increase was observed of some n-3 polyunsaturated fatty acids like eicosapentaenoic and docosahexaenoic acid whereas arachidonic acid decreased. The present study indicates a favourable influence of pantethine not only on plasma but also on platelet lipids which could be of value in delaying the development of atherosclerosis in dyslipidaemic patients.

Administration, Oral↗

Effect of a single Ditazole dose on platelet aggregation and prostaglandin formation.

The in vitro activity of the non-steroidal anti-inflammatory agent Ditazole was investigated in a group of 20 male patients at thrombotic risk in comparison with placebo in a completely randomized cross-over design. A single Ditazole administration was able to induce a significant decrease in the number of circulating platelet aggregates (CPA), platelet aggregability by ADP and in thromboxane production by platelets. No significant changes were found in platelet cAMP concentration and in plasma 6keto-PGF1 alpha levels. Present results indicate that Ditazole affects platelet aggregation in a double way, by decreasing both the reversible and the ADP-induced aggregation. The lack of effects on plasma 6keto-PGF1 alpha concentration suggests that Ditazole can reduce platelet aggregation without affecting prostacyclin production.

6-Ketoprostaglandin F1 alpha↗

In vitro investigation on the antiaggregating activity of ditazole.

The antiaggregating activity of ditazole, a non-steroidal antiinflammatory drug, was assayed in vitro on platelets from 16 subjects at high risk of thrombosis and from 14 healthy control subjects. This study was performed by the photometric method (Born) on platelet rich plasma (PRP), preincubated with ditazole at final concentrations of 1, 2.5, 4 and 40 micrograms/ml. Aggregation was induced by 1 and 2 microM ADP, 1 and 10 microM adrenaline and by 1 and 2 mM arachidonic acid (AA). Ditazole (1 microgram/ml) inhibited platelet aggregation induced by ADP (1 and 2 microM) in both groups and significantly reduced at all concentrations tested adrenaline (10 microM) induced aggregation in subjects at risk, but only at 2.5 micrograms/ml concentration in control subjects. Arachidonic acid (1 mM)-induced aggregation was significantly reduced by ditazole at all concentrations tested in control subjects but only at 2.5 micrograms/ml or more in subjects at risk. In both groups, however, aggregation induced by 2 mM AA was significantly reduced by ditazole at all concentrations tested.

Adenosine Diphosphate↗

Blood velocity in the coronary artery circulation: relation to thromboxane A2 levels in coronary sinus in patients with angiographically normal coronary arteries.

In the present study, we report the finding that some patients with spontaneous typical angina and angiographically normal coronary arteries present an abnormal cardiocoronary capacity to produce thromboxane A2, both in basal conditions and after sympathetic stimulation. The levels of thromboxane A2 in coronary sinus are significantly correlated to the rate of clearance of contrast medium in coronary circulation. Such a finding might be useful in better understanding the interesting syndrome of angina with normal coronary arteries.

Adult↗

Hemostatic alterations during human immunodeficiency virus infection: a review.

Human immunodeficiency virus (HIV) infection is associated to different clinical and laboratory hemostatic alterations. The most important is thrombocytopenia, which very often leads to a picture indistinguishable from idiopathic thrombocytopenic purpura with poor clinical relevance but with possible important problems of differential diagnosis. Thrombotic thrombocytopenic purpura is sometimes associated to HIV infections, although only few reports there exist. Finally, the high incidence of lupus anticoagulant in some phases of HIV infection has not a clinical relevance, but is essentially a laboratory finding which is to be known because it can cause a prolonged partial thromboplastin time.

Acquired Immunodeficiency Syndrome↗

Markers of increased thrombin generation.

Blood clotting activation causes an increased thrombin generation. The direct measurement of plasma thrombin is not feasible due to the absence of reliable methods. Thus, only indirect approaches are possible. Different markers of thrombin generation have been proposed in the past years. Some methods are nowadays of historical interest. Among various methods reported the 'gold standard' is fibrinopeptide A assay, while thrombin-antithrombin complexes assay needs further validation to be employed as a reliable index of increased thrombin generation, and more recent methods (such as those for F1+2 fragment and for protein C activation peptide) are not available for routine use.

Antithrombin III↗

Venous thromboembolism in renal transplant recipients: high rate of recurrence.

Few data are available on the incidence of venous thromboembolism occurring in renal transplant recipients and optimal duration of oral anticoagulant therapy after thrombotic episode. Our study was performed to evaluate the risk of thrombosis recurrence in patients developing a first episode. Among 484 renal transplant patients 34 (7%) developed a first thromboembolism and were referred to the Thrombosis Centre: 28 patients (group 1) were prospectively studied, after stopping anticoagulants. Group 1 was compared with a group of 84 patients without an history of renal disease who had suffered from a first thrombotic episode and were matched for age, sex, and type of thrombotic event (group 2). During follow-up, 14/28 group 1 patients and 8/84 group 2 patients experienced thrombotic recurrence (P = .0001). Our data outline the high risk of recurrence in renal transplant recipients. Strategies for recurrence prevention are needed taking into account the high bleeding risk of anticoagulants in renal transplant patients.

Adult↗