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Biomedical subjects

C Bevilacqua

Publications and source records attributed to C Bevilacqua.

At least 19 recordsLinked to original sources
PubMed1992

Protective role of heparin on in vitro functional aortic response in Watanabe heritable hyperlipidemic rabbits.

The effects of prolonged in vivo heparin treatment upon vasomotor responses and content of cholesterol and energy related compounds were studied in isolated thoracic and abdominal aortas from Watanabe heritable hyperlipidemic (WHHL) rabbits. Unfractionated heparin was administered subcutaneously (2 mg/kg twice a day) to 3-month-old WHHL rabbits for a period of 6 months. A group of WHHL rabbits was treated with saline solution and considered as control. Aortic cholesterol infiltration and serum cholesterol were not significantly decreased by the prolonged heparin treatment. In heparin-treated WHHL rabbits, the in vitro aortic endothelium-dependent relaxation produced by acetylcholine or calcimycin (A 23187) was greater than in saline-treated WHHL group. ATP-induced aorta relaxation (endothelium-dependent and endothelium-independent) did not vary significantly in the two groups of WHHL rabbits, even after mechanical removal of endothelium. Also the noradrenaline-induced aorta contraction did not vary between the two groups of WHHL rabbits. No significant variation in energy-related compounds (except for ADP) was found in the aortic arch. These results suggest that heparin produces a protective effect on aortic tissue by acting mainly at endothelial level.

Adenosine Triphosphate↗
PubMed1991

Acute carotid artery occlusive thrombosis and its pharmacological prevention in the rabbit.

A simple and reproducible method to induce an occlusive thrombus in rabbit carotid artery is reported. Rabbits were anesthetized and prepared to record arterial pressure, heart rate, and carotid blood flow. A critical stenosis of a damaged carotid artery was obtained using an external plastic cylinder. Complete occlusion occurred within 6 to 12 minutes, as measured by the decrease in blood flow. Both stenosis of the vessel and deliberate damage (clamping by surgical forceps) were found essential to occlusion. Occlusion was prevented by administration of heparin (200 IU/kg), tissue plasminogen activator (300 micrograms/kg), iloprost (10 micrograms/kg) or the synthetic thrombin inhibitor, FPRCH2Cl (0.5 mg/kg), while ASA (100 mg/kg) was uneffective. The procedure permits an easy and rapid evaluation of thrombus formation and of anti-thrombotic drugs affecting the hemostatic process.

Acute Disease↗
PubMed1989

In K562 leukemia cells treated with doxorubicin and hemin, a decrease in c-myc mRNA expression correlates with loss of self-renewal capability but not with erythroid differentiation.

The decrease in c-myc mRNA expression occurring in leukemia cell lines induced to differentiate is supposed to be an early event of the commitment to the differentiation program. Alternatively, the decrease in c-myc mRNA expression could be simply a consequence of loss of the self-renewal capability characteristic of the terminal differentiated phenotypes. In an attempt to clarify these hypotheses, we analysed comparatively the kinetics of variations in c-myc mRNA expression, hemoglobin synthesis, DNA and RNA syntheses, cell cycle kinetics and self-renewal capability in normal and hemin-treated K562 leukemia cells exposed for different periods of time to the antitumoral antibiotic doxorubicin. Times of exposure to doxorubicin were either 2 h, which resulted in reversible induction of hemoglobin synthesis without significant cytostatic effects, or continuously for more than 5 days, which resulted in an irreversible induction of hemoglobin synthesis and in the complete and irreversible loss of self-renewal activity. Comparative analysis of the experimental data indicated that the decrease in c-myc mRNA expression correlated with the loss of replicative activity, possibly due to an irreversible cytostatic effect of the long exposure to doxorubicin, but not with the commitment to the differentiation programs.

Blotting, Northern↗
PubMed1987

In vitro and ex vivo effects of indobufen on human platelet aggregation, the release reaction and thromboxane B2 production.

We have done a comprehensive study in normal volunteers of the in vitro and ex vivo effects of the antiplatelet agent indobufen on platelet aggregation, the release reaction and thromboxane B2 (TxB2) production as induced by different concentrations of aggregating agents. At low concentrations (10 microM), indobufen completely inhibited secondary platelet aggregation, the release reaction and TxB2 production stimulated by ADP, epinephrine and low concentrations of platelet-activating factor (PAF acether). Higher concentrations of indobufen (100 microM) completely inhibited TxB2 production, platelet aggregation and ATP release induced by arachidonic acid (1 mM) or collagen (2 micrograms/ml). The inhibitory effect was partially overcome by higher concentrations of arachidonic acid (2 mM). Data obtained ex vivo 2 h after the oral administration of 200 mg indobufen to 8 normal volunteers were in keeping with those of the in vitro study. We conclude that indobufen inhibits platelet aggregation and the release reaction by inhibiting the platelet arachidonate pathway.

Adenosine Triphosphate↗
PubMed1987

Fibrinogen-independent aggregation and deaggregation of human platelets: studies in two afibrinogenemic patients.

Platelets from two afibrinogenemic patients were used to determine whether fibrinogen is essential for platelet aggregation and to examine whether released fibrinogen contributes to the stabilization of platelet aggregates when platelets have been induced to aggregate and release their granule contents by stimulation with thrombin. The addition of adenosine diphosphate (ADP) to platelet-rich plasma (PRP) or to suspensions of washed platelets from the afibrinogenemic patients caused the formation of small aggregates, which was either not inhibited or only slightly inhibited by the F(ab')2 fragments of an antibody to fibrinogen but was inhibited by an antibody (10E5) to glycoprotein IIb/IIIa. Thus there is a component of ADP-induced platelet aggregation that is not dependent on fibrinogen or other plasma proteins but is dependent on glycoprotein IIb/IIIa. There was little difference in the extent of aggregation and the release of granule contents of normal and afibrinogenemic platelets in response to the release-inducing agents collagen, platelet-activating factor (PAF), sodium arachidonate, or thrombin. With normal or afibrinogenemic platelets, aggregation by thrombin (0.2 U/mL or higher) was not inhibited by the F(ab')2 fragments of an antibody to human fibrinogen. Deaggregation by combinations of inhibitors of platelets aggregated by 1 U/mL thrombin showed no difference between platelets from afibrinogenemic and control subjects, indicating that released fibrinogen does not make a major contribution to the stabilization of platelet aggregates formed by thrombin stimulation.

Adenosine Diphosphate↗
PubMed1982

[Prevention of viral hepatitis B with specific gamma globulin. Results of 2 years' experience in a hemodialysis center].

Prophylaxis with gamma globulins specific for virus hepatitis B was carried out at the Trieste Haemodialysis Centre from December 1979 to December 1981. Since no clear distinction could be drawn between HBsAg-positive dialysed subjects, all staff and patients at the Centre were regarded as constantly at risk for contagion, and hence in the post-exposure state. Those who refused prophylaxis were excluded, together with surface antigen carriers and subjects with antibodies. Specific gamma globulins (Uman-Big) were given at a dose of 0.06 cc/kg at intervals of 90-105 days, together with 0.02 cc/kg standard gamma globulins for conjectured protection against non-A and non-B hepatitis. No allergic reactions worthy of not were observed. Only one patient positivised of all those who underwent continuous prophylaxis. New carriers of HBsAg gradually decreased in number from 1976 to 1981, initially due to the adoption of disposable filters, subsequently owing to partial separation of Au-positives, and finally, in a significant manner, with the introduction of prophylaxis with specific gamma globulins.

Hepatitis B↗
PubMed1976

[Geriatric department].

The medicolegal, health and organisational aspects of the department introduced by law into the Italian hospital structure are examined. A comparison is made with the proposals made in the single national contract for hospital workers. An account is given of the Senior Citizen's Department set up at Trieste, in the light of the city's demographic and socioeconomic situation.

Aged↗