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Biomedical subjects

G Lippi

Publications and source records attributed to G Lippi.

At least 91 records · Page 5Linked to original sources
PubMed1993

Homologous priming in chemotactic peptide-stimulated neutrophils.

The kinetics and dose-dependence of activation of human neutrophils exposed to sequential additions of the chemotactic peptide n-formyl-methionyl-leucyl-phenylalanine (fMLP) have been investigated by multiwell microplate assays. Treatment of neutrophils with medium-high doses (from 10(-8) to 5 x 10(-7) M) of fMLP caused activation of superoxide anion (O2-) production, but prevented further activation by a subsequent addition of an optimal dose (from 10(-7) M to 5 x 10(-7) M) of fMLP. These findings represent an example of cell desensitization, or adaptation. However, neutrophils treated with low, sub-stimulatory doses (from 10(-10) to 5 x 10(-9) M) of the peptide and then treated with optimal doses of fMLP exhibited an O2- production that was two to three-fold higher than that induced by the same optimal doses on untreated cells. A similar phenomenon of homologous priming of the oxidative metabolism of neutrophil has not previously been described or characterized. Priming was maximal after about 30 min of incubation with fMLP, which differed from desensitization, which required only a few minutes. Homologous priming was not confined to O2- production, but was also observed with the release of the granule enzyme, lysozyme. Low doses of fMLP were also capable of triggering an increase of intracellular free Ca2+ and of fMLP membrane receptors, which are possible mechanisms responsible for priming.

Calcium↗
PubMed1993

Dual effects of formylpeptides on the adhesion of endotoxin-primed human neutrophils.

Neutrophils, treated with sequential additions of bacterial products such as endotoxin (E. Coli lipopolysaccharide, LPS) and the chemotactic peptide N-formyl-methionyl-leucyl-phenylalanine (fMLP), undergo to metabolic activation and express membrane-anchoring proteins that promote adhesion to serum-coated culture wells. By investigating the dose-response relationships of these phenomena, we have found that: (a) resting neutrophils do not produce a significant amount of superoxide (O2-) and show only minimal adhesion to serum-coated plastic surfaces; (b) fully activatory doses (> 5 x 10(-8) M) of fMLP induce the release of O2- and a significant increase of the cell adhesion; (c) pretreatment of the cells for 1 h with LPS augments cell adhesion to serum-coated culture wells in the absence of further stimulation and primes the neutrophils to enhanced fMLP-dependent O2- release; (d) addition of low, substimulatory doses of fMLP (from 10(-10) M to 5 x 10(-9) M) inhibits and reverses the adhesion of LPS-treated cells, (e) high fMLP doses ( > 10(-7) M) are additive to LPS in promoting adhesion. Phorbol-myristate acetate (> 10(-9) M) increased adhesion in both normal and LPS-treated neutrophils, but low doses of this stimulant did not inhibit adhesion. Low doses (10(-9) M) of fMLP increased intracellular cyclic AMP in both normal and LPS-treated neutrophils, suggesting that stimulus-induced rises in cAMP may be the negative signal responsible for down-modulation of adhesion.(ABSTRACT TRUNCATED AT 250 WORDS)

Antigens, CD↗
PubMed1992

Acute phase proteins in alcoholics with or without liver injury.

Acute phase proteins behaviour has been examined in chronic alcoholics to verify the hypothesis that chronic alcohol consumption stimulates the hepatic synthesis of acute phase proteins. Certain acute phase proteins were studied in two groups of alcoholics, one with and one without liver damage, and in a third group of healthy volunteers. The results show that the acute phase proteins were similar in the two groups of alcoholics, but differed when compared to the control group. The authors have concluded from these results, that chronic alcohol consumption causes a serum increase of: mucoproteins (p less than 0.001), alpha 1 acid glycoprotein (p less than 0.05), haptoglobin (p less than 0.05) and fibrinogen (p less than 0.02). Such increases are independent from the existence of liver damage.

Acute-Phase Proteins↗
PubMed1992

[Defibrotide vs. calcium heparin in the prevention of deep vein thrombosis in gynecologic oncologic surgery].

Eighty-one patients were submitted to gynaecological malignancy surgery in a randomized study aimed at the evaluation of the efficacy of defibrotide (40 patients) and calcium heparin (41 patients) in perioperative prophylaxis. They were randomly allocated to defibrotide group (400 mg bid im starting one day before surgery and continuing until the 7th postoperative day) or calcium heparin group (5000 IU bid sc starting two hours before surgery and continuing likewise for 7 days). No cases of DVT diagnosed by means of a Doppler CW were observed in either treatment group. Laboratory parameters have shown similar modifications in the two treatment groups. Three cases of bleeding were observed in the calcium heparin group while no cases of bleeding were detected in the defibrotide group. The results obtained suggest that defibrotide is at least as effective as calcium heparin in perioperative DVT prevention and that the former drug has a possibly better tolerability profile, due to a decisively lower tendency to bleeding.

Aged↗
PubMed1990

Advantages of a new anticoagulant in routine hematology on the Coulter Counter S-Plus STKR analyzer.

The authors report the advantages of a new anticoagulant-antiaggregant mixture that avoids the deleterious effects of ethylenediaminotetraacetic acid (EDTA) on mean platelet volume and also prevents EDTA-induced platelet clumping. It is suitable for routine cell counting and sizing with the Coulter Counter S-Plus STKR. The values of the common hematologic parameters agree well with those from EDTA-treated samples and are stable for at least eight hours after sampling.

Anticoagulants↗
PubMed1989

[Pharmacologic prevention of deep postoperative venous thrombosis in general surgery].

The most commonly used pharmacological aids employed in the prevention of peroperative deep venous thrombosis in general surgery are reviewed in brief. The probable action mechanisms, recommended doses, laboratory parameters to be monitored, side-effects, contraindications and effectiveness shown in the main clinical trials carried out are illustrated.

Fibrinolytic Agents↗
PubMed1989

[Defibrotide versus heparin in antithrombotic prophylaxis in gynecological surgery].

Deep venous thrombosis (DVT) can be a significant complication of the postoperative course in gynaecological surgery, because of traumatism and compression to which the vascular pelvic structures are subjected. A protocol was therefore designed to evaluate the effectiveness and tolerability of defibrotide, a new antithrombotic and profibrinolytic drug, compared with low-dose heparin. The study was conducted on 102 women, undergoing major gynaecological surgery for benign and malignant affections, randomly assigned to the following two treatment groups. A) defibrotide (400 mg i.v./i.m. b.i.d., starting the day before the surgery for 8 days); B) calcium heparin (5000 IU s.c. b.i.d., starting on the day of surgery, for/days). Clinical, haematological and instrumental (Doppler ultrasound) parameters were assessed and no major events were noted in either of the two treatment groups though in the calcium heparin group, 2 patients showed clinical signs of DVT (not confirmed by Doppler ultrasound) and no side effects were noticed, except for a cutaneous rash in one defibrotide patient and an episode of bleeding on the third postoperative day in a patient treated with calcium heparin. Defibrotide proved as effective as calcium heparin in the prevention of DVT in gynaecological surgery.

Clinical Trials as Topic↗
PubMed1985

Hemostatic Balance Index in TIA patients: sex-related changes.

In order to evaluate the occurrence of hemostatic disorders, 37 patients with transient ischemic attacks (TIAs) and 50 control subjects were studied by means of the Hemostatic Balance Index (H.B.I.) derived from Raby's Thrombodynamic Potential Index (T.P.I.) and Fearnley's Whole Blood Diluted Lysis Time (W.B.D.L.T.). Results showed a significant increase in T.P.I. and a tendency to a decrease in fibrinolytic activity in the TIA group: H.B.I. was shown to be significantly increased, thus indicating a pro-thrombotic imbalance in these patients. The occurrence of similar changes in TIA females when compared to male patients marks the importance of plasmatic factors in the mechanism of thrombotic disorders in females with cerebrovascular disease.

Adult↗
PubMed1984

Hemostatic disorders in 25 patients with limited and uncomplicated thyroid and breast cancer: prophylactic and therapeutic considerations.

In order to evaluate the efficacy of an anticoagulant treatment in neoplasia, we have looked for the existence and the possible role of hemostatic unbalance in patients affected by limited and uncomplicated thyroid and breast cancer by examining hemostasis in 25 patients. Our data allowed us to evidentiate an accelerated and increased fibrinoformation associated with the presence of plasminogen's activation inhibitor which overlaps the increased plasminogen's activators. We evidentiated also an increase of platelet functions in vitro and of their activation in vivo. These findings support the hypothesis of a possible role played by hemostasis alterations in the pathogenesis of thromboembolic complications, cancer growth and/or metastatization, and justify prophylactic and therapeutic anticoagulation.

Adult↗
PubMed1984

[Left ventricular function in patients under peritoneal dialysis treatment].

M-Mode echocardiogram and systolic time intervals were obtained in 24 patients with end-stage chronic renal failure before and after peritoneal dialysis in order to evaluate their left ventricular function. Before dialysis 9 patients (group A) showed an echocardiographic pattern of dilated cardiomyopathy, i.e. increased left ventricular end-diastolic dimension (EDD) and volume (EDV), reduction of fractional shortening (FS%), of circumferential fiber shortening (Vcf) and of ejection fraction (EF). Seven patients (group B) had the morphological and functional features of asymmetric septal hypertrophy: ratio of interventricular septum to posterior wall thickness (IVS/PWT) greater than 1.3, reduced EDD and EDV. Eight uraemics (group C) had no specific feature of cardiac disease, but only aspecific echocardiography signs of myocardial derangement. Peritoneal dialysis appeared to be associated with gradual improvement of the contractile state in group A patients, with reduction in echocardiographic asymmetric septal hypertrophy in group B uraemics, and with an aspecific increase in cardiac performance in group C patients. It is concluded that: end-stage chronic renal failure may have echocardiographic pattern of dilated or asymmetric hypertrophic cardiomyopathy; peritoneal dialysis significantly improves the morphological and functional derangements of both clinical conditions.

Adult↗
PubMedDate not supplied

Total and free PSA serum concentrations are not influenced by extensive physical exercise and bicycle riding.

Vigorous and prolonged physical exercise and mechanical involvement of the perineal region might influence prostatic function and measurement of both total (PSA) and free prostate specific antigen (fPSA), decreasing the diagnostic efficiency of the laboratory screening for either benign or neoplastic prostate disorders in athletes. To investigate the effects of regular and strenuous physical exercise with or without bicycle riding on integrity and biochemical function of prostatic tissue, we measured serum PSA and fPSA in 69 elite and professional cyclists, 31 members of the Italian national cross-country ski team, and in 43 sedentary healthy controls. The concentration of both PSA and fPSA did not differ significantly between sedentary individuals and physically active cross-country skiers (PSA 0.43 +/- 0.30 vs. 0.36+/-0.25, ns; fPSA 0.16+/-0.12 vs. 0.12+/-0.12, ns) or cyclists (PSA 0.43 +/- 0.30 vs. 0.36 +/- 0.23, ns; fPSA 0.16 +/- 0.12 vs. 0.13 +/- 0.08, ns), and the relative distribution of values appeared almost overlapping. We hypothesize that neither a heavy and regular physical exercise nor the extensive and prolonged mechanical involvement of the prostate region by the bicycle riding have significant influence on release of both PSA and fPSA.

Adult↗
PubMedDate not supplied

Severe preeclampsia in antithrombin III deficiency with no history of venous thromboembolism.

Complications of pregnancy, such as preeclampsia, placental abruption, fetal growth retardation, still-birth and fetal death are associated with an increased frequency of pro-thrombotic abnormalities. We describe a case of severe preeclampsia and multiple placental infarctions in a 28-year-old woman at 31 weeks' gestation. Despite a negative personal history for venous thromboembolism, coagulation screening for thrombophilia detected an isolated antithrombin III deficiency. In view of the high prevalence of pro-thrombotic complications, laboratory screening for thrombophilia would be advantageous in women with complicated pregnancies, to ensure adequate management in high-risk situations, as suggested by larger-scale clinical investigations.

Adult↗