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Biomedical subjects

G Grignani

Publications and source records attributed to G Grignani.

107 records · Page 6Linked to original sources
PubMedDate not supplied

Antithrombin III biological activity and emotional stress in patients with coronary artery disease.

We studied the effect of emotional stress (mental arithmetic for 10 minutes) in ten postinfarction patients and in ten age-matched, apparently healthy subjects as controls. Blood samples for the determination of epinephrine and AT III levels were taken in basal conditions, at the end of mental stress and after 30 minutes of recovery. Mental stress induced a significant increase in epinephrine levels and a significant decrease in AT III levels in control subjects. Both parameters returned to baseline values after 30 minutes of recovery. On the contrary, in postinfarction patients AT III levels of recovery were still significantly lower than those of baseline, suggesting a reduced ability to restore the original concentration of this physiologic inhibitor. Our data can contribute to a better understanding of the complex relationships among phychosocial factors, the haemostatic system and vascular disease.

Adult↗
PubMedDate not supplied

[ProMACE-MOPP vs. ProMACE-CytaBOM polychemotherapies in the treatment of large-cell and unclassifiable non-Hodgkin's lymphomas].

The results of two distinct and successive clinical pilot studies investigating feasibility of aggressive chemotherapy in large cell and unclassified non-Hodgkin's lymphomas are reported. In the first study (1986-87) the ProMACE-MOPP chemotherapy (P-M), a 2nd generation regimen, was administered to 10 patients, whereas in the second study (1987-88) the ProMACE-CytaBOM schedule (P-C), a 3rd generation regimen, was administered to 13 patients. The clinical and prognostic features of the two groups of patients were quite comparable, the only difference being the different follow-up times (median: 43 vs 26 months). The number of complete remissions, freedom from relapse and overall survival were slightly better in the P-M group, with-out a statistically significant difference, despite the longer follow-up time. Hematological toxicity was higher in the P-M study, while gastrointestinal (mucositis, hepatic transitory damage) and neurological toxicity (peripheral neuritis) were somewhat lower. In conclusion, the P-M regimen is worth considering for the treatment of high grade malignant lymphomas, although it was not recently designed and is not widely used at present.

Adolescent↗
PubMedDate not supplied

Proaggregating and procoagulant activities of human mesothelioma tumor cells at different stages of "in vitro" culture.

BACKGROUND: The mechanisms of the interactions between tumor cells and the hemostatic system are not completely understood; the purpose of this study was to elucidate whether tumor cells grown "in vitro" express the same proaggregating and procoagulant activities as cells isolated from tumor tissues, and whether the activities of such cultures are constant and consistent over time. METHODS: Tumor cells were collected and cultured from the pleural fluid of a 71-year-old patient with a sarcomatous malignant mesothelioma. Platelet aggregating activity was studied by adding tumor cells to platelet rich plasma or to washed, aequorin-loaded platelets. The procoagulant activity of the tumor cells was measured by the one-stage recalcification time of different humans plasma substrates. RESULTS: Cells harvested after 4 culture passages possessed low, ADP-dependent platelet aggregating activity, while those studied after 16 or 40 passages activated platelets through the production of thrombin. In the washed platelet system and in the presence of trace amounts of platelet poor plasma, the difference in the aggregating activity of various tumor cell populations was more evident. Normal mesothelial cells did not induce platelet aggregation. Procoagulant activity (tissue factor-like) was low in normal mesothelial cells and in tumor cells after 4 passages, and it was about 10 times higher in tumor cells after 16 or 40 passages. CONCLUSIONS: Results obtained with tumor cells cultured "in vitro" should be considered with caution because their effects are different from those of freshly isolated cells and may not be constant in the different culture passages.

Adult↗
PubMedDate not supplied

Human tumor cells cultured "in vitro" activate platelet function by producing ADP or thrombin.

We studied the effects on platelet function of different human tumour cells cultured "in vitro": Mo T lymphocyte cell line, NCI-N592 small cell lung carcinoma cell line, and 5637 bladder carcinoma cell line. Mo and NCI-N592 cells possessed a slight, dose-dependent platelet aggregating activity, which was completely abolished by apyrase and unaffected by hirudin. The cell-free supernatant also induced an aggregation response, which was very similar to that obtained with tumour cell suspensions. The presence of ADP in the cell-free supernatants of cell suspensions was confirmed by HPLC analysis. On the contrary, aggregation induced by 5637 cells was preceded by a significant lag phase; it was not affected by apyrase but it was abolished by hirudin, and the cell-free supernatant had no effect. These data suggest that Mo and NCI-N592 cells activate platelets by producing ADP, while 5637 cells stimulate platelet function by generating thrombin. The amount of ADP produced by the first two tumour cell lines was measured by bioassay: the extent of such production was similar for both cell lines and the maximum was reached after 60 minutes and maintained for up to 3 hours. These results suggest that neoplastic cells can activate platelets by different mechanisms: such investigations should be performed in homologous systems and in well-defined experimental conditions.

Adenosine Diphosphate↗
PubMedDate not supplied

[The in-vivo effect of dihydroergocristine on human platelet function].

An acute test was run on healthy volunteers to assess the effect of i.v. dihydroergocristine methansulphonate on platelet function. The number of platelets was virtually unaffected, whereas adhesion to glass was significantly reduced. A direct and specific effect was noted on the 1st, adrenaline aggregation wave, while the 2nd wave (expression of ADP) induced aggregation did not appear to have been significantly altered. It is felt that further examination of the alpha-adrenergic block induced by the drug should be under-taken in view of the recent literature data which explain the inability of commonly employed anti-aggreganting drugs, such as acetylsalicylic acid, to prevent and treat atherothrombosis, in spite of the encouraging experimental results.

Adenosine Diphosphate↗
PubMedDate not supplied

Current concepts in coronary thrombolysis.

Thrombolytic therapy has become standard care in treating acute myocardial infarction. Fibrinolytic drugs such as streptokinase, APSAC and urokinase are non fibrin specific, and induce systemic activation of the fibrinolytic process, while t-PA and prourokinase are fibrin specific since they are able to activate mainly fibrin bound plasminogen. Both groups of thrombolytics exert different and opposing effects on the hemostatic balance: indeed, they have antithrombotic as well as prothrombotic properties, and this may be important for explaining therapeutic failures or reocclusions. New strategies have been considered or are under investigation for further improving the already excellent efficacy of thrombolytic treatment in myocardial infarction: combined administration of fibrinolytic agents, thrombus-targeted thrombolytic drugs, association with other drugs both effective and ineffective on the hemostatic process. At present, however, the first priority still seems to be a continuing effort to increase the percentage of patients treated with thrombolytics, since the benefits of this therapy have already been clearly demonstrated.

Humans↗
PubMedDate not supplied

[Neurocysticercosis and epilepsy. Description of a clinical case].

Since 1985 infection by suin tapeworm Taenia Solium seems to have disappeared in Italy, but patients may still exist which have contracted many years ago the disease that has followed its natural course. We report the case of an Italian, 50 year-old-man with neurocysticercosis presenting with generalized seizures. CT and MR showed typical calcific and cystic lesions in the brain. Rx scans of muscles revealed the presence of fusisorm calcific lesions suggestive for cysticercosis and the serum levels of specific antibodies confirmed the diagnosis. The patient was treated with albendazole with no regression of cerebral lesions after one month, but simultaneous treatment with antiepileptic drugs was able to control completely neurologic symptoms.

Brain Diseases↗
PubMedDate not supplied

Effect of interferon alpha, interferon gamma and tumor necrosis factor on the procoagulant activity of human cancer cells.

BACKGROUND: It is not known whether the different cytokines may influence the procoagulant activity of cancer cells; the purpose of this study was to investigate the effect of interferon alpha, interferon gamma and tumor necrosis factor on the procoagulation capacity of human cancer cells cultured "in vitro" or isolated from tumor tissues. METHODS: "In vitro" cultured tumor cell lines were derived from a patient with malignant mesothelioma and a patient with lung adenocarcinoma. Cells isolated from 6 carcinomas of different origin were also investigated. The procoagulant activity of the cells before and after treatment with the cytokines was expressed as RBT U/10(5) cells or RVV U/10(5) cells. RESULTS: Short-term incubation of tumor cells cultured "in vitro" with cytokines did not modify their procoagulant activity; after longer incubation however, interferon alpha induced a significant increase in the procoagulant activity of mesothelioma cells, while interferon gamma induced and increase in the procoagulant activity of lung adenocarcinoma cells. Furthermore, short-term incubation of cells isolated from tumor tissues with interferon gamma or tumor necrosis factor resulted in a significant increase of procoagulant activity, while interferon alpha had no effect. CONCLUSIONS: Altogether, these data demonstrate that the cytokines may influence the expression of the different procoagulant activities of tumor cells.

Blood Coagulation↗
PubMedDate not supplied

Cryopreservation of human platelets using dimethyl sulfoxide and glycerol-glucose: effects on "in vitro" platelet function.

BACKGROUND: The technique of freezing blood platelets could be very useful in the transfusion support of thrombocytopenic patients. The best method of platelet cryopreservation still remains an object of debate, though it has been suggested that dimethyl sulfoxide (DMSO) is more effective than glycerol-glucose as a cryopreservative. However, few studies have directly compared platelets cryopreserved with different methods. METHODS: We compared "in vitro" function of platelets cryopreserved with 5% dimethyl sulfoxide (DMSO) or 3% glycerol-glucose at -140 degrees C. Platelet aggregation and release reaction were studied with a Lumi aggregometer, thromboxane B2 (TxB2) production by radioimmunoassay, and Ca++ movement by the Fura 2 method. RESULTS: Cryopreservation with both of the methods dramatically reduced the ability of platelets to release ATP and to aggregate in response to single agonists. In contrast, cryopreserved platelets maintained their ability to aggregate after stimulation with paired agonists and to produce TxB2. Cytoplasmic Ca++ increase induced by thrombin was observed in the glycerol-preserved platelets, while it was nearly absent in the DMSO-preserved ones. CONCLUSIONS: We suggest that cryopreservation with glycerol-glucose or DMSO induces similar defects of platelet function. The damage is severe, but platelets are still able to respond to strong stimulation.

Blood Platelets↗
PubMedDate not supplied

In vitro effect of reduced glutathione on platelet function.

BACKGROUND: Generation of reactive oxygen species has been suggested to represent an important regulatory mechanism of platelet reactivity in both physiological and pathological conditions, and free-radical scavengers may inhibit platelet activation. The purpose of the present study was to investigate the effect of reduced glutathione (GSH) on different platelet functions stimulated by ADP, collagen or PAF. METHODS: Platelet aggregation was investigated by Born's method. TxB2 and PDGF levels were measured by radioimmunoassay. RESULTS: GSH at the lowest dose (1 mM) did not significantly modify aggregation, TxB2 production or PDGF release induced by ADP or PAF, while at higher concentrations (3 mM or 10 mM) it significantly inhibited all parameters. Collagen-induced platelet activation was remarkably less sensitive to GSH, since aggregation was not significantly reduced, while TxB2 production was reduced by GSH when employed at concentrations of 3 mM or 10 mM, and PDGF release was inhibited only by the highest dose (10 mM). IC50 for inhibition of platelet aggregation, TxB2 production and PDGF release were between 1.43 and 2.36 mM when platelets were stimulated with ADP, between 2.23 and 8.90 mM when PAF was used and between 8.00 and 16.30 mM when collagen was the agonist. CONCLUSIONS: Our data suggest that GSH may act as a physiological inhibitor of platelet activation and may therefore contribute to the regulation of platelet reactivity.

Adenosine Diphosphate↗