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Biomedical subjects

G Grignani

Publications and source records attributed to G Grignani.

At least 73 records · Page 4Linked to original sources

Activation of platelet prostaglandin biosynthesis pathway during neoplastic cell-induced platelet aggregation.

In a previous study we found a correlation between metastatic potential and platelet aggregating activity in sublines of a benzopyrene-induced murine fibrosarcoma ( mFS6 ); the purpose of the present work was to elucidate the role of thromboxane biosynthesis by platelets and/or by neoplastic cells in the activation of platelets in this system. The cells of the more malignant subline induced higher aggregation and TxB2 production than those of the non metastasizing one. The supernatants of aggregating cell suspensions contained very few TxB2; furthermore, preincubation of platelets with ASA or Apyrase resulted in inhibition of aggregation and TxB2 production, while preincubation of the cells was ineffective; these results suggest the platelet origin of the measured TxB2 and indicate that platelet-derived ADP plays an important role in their activation, while the production of ADP by the cells does not seem to be relevant in this model. The involvement of platelet prostaglandin biosynthesis pathway in neoplastic cell induced platelet activation could play an important role in the development of platelet-dependent tumour metastasis.

Animals↗

Castleman's disease with coagulation defect. A case report.

The case of a young man with the plasma cell type of Castleman's disease is described. Beyond the well known systemic manifestations the coagulation tests showed a decrease in the activity of factors V, VIII and X due to the presence of lupus-like circulating anticoagulants. After surgical excision of the mediastinal mass both hematochemical pathological data and the coagulation defect disappeared. It is suggested that the lupus-like anticoagulant was secreted by the tumor.

Adult↗

Interactions between neoplastic cells with different metastasizing capacity and platelet function.

We have examined the effects on platelet function of two sublines (M4 and M9) derived from spontaneous lung nodules of a benzopyrene-induced murine fibrosarcoma (m FS6). The subline M4 was more metastatic and the subline M9 less metastatic than the primary tumour. Only the more malignant cells were able to induce irreversible aggregation of human platelets; this effect was concentration-dependent and was associated with the release of serotonin by platelets. Both aggregation and release were inhibited by preincubation of platelets with ASA, not by preincubation of the cells. The supernatants of cell suspensions had no aggregating activity. However, the neoplastic cells in culture media released an activity directly stimulating platelet aggregation and potentiating the platelet response to ADP; again, this activity was higher for the more malignant cells and the effects were inhibited by preincubation of platelets with ASA. These results suggest a role for platelets in the development of tumour metastases.

Adenosine Diphosphate↗

[In vitro effect of culture fluids from neoplastic tissues on platelet aggregation. I. Human tumors of the gastrointestinal tract].

The effects on platelet function of culture media from 7 human tumours of the gastroenteric tract have been studied on platelet rich plasma obtained from 28 apparently normal subjects. Platelet aggregation was investigated according to Born's method. Some of the culture media showed an aggregating activity on platelets, while others did not; after dialysis, however, also the last ones aggregated platelets. Furthermore all the media both before and after dialysis were able to increase the platelet response to low doses of ADP (3 microM), and these effects were inhibited by Aspirin (0,1 mM). These results suggest that the tumours investigated release stimulating activities on platelet function and that these interactions can be inhibited pharmacologically.

Adenosine Diphosphate↗

[In vitro effect of culture fluids from neoplastic tissues on platelet aggregation. II. Experimental tumors].

We have investigated the effects on platelet function of culture media from 2 sublines of a benzopyrene-induced murine sarcoma (mFS6). Platelet aggregation was investigated according to Born's method. The cell line with greater "in vivo" invasiveness showed higher aggregating activity and higher increase on ADP-induced aggregation; these effects were inhibited by the preincubation of platelets with Aspirin (0,1 mM). These results suggest the role of platelets in metastasis formation; the possibility to inhibit pharmacologically the interactions between platelets and tumour cells could have important implications from both speculative and practical viewpoints.

Adenosine Diphosphate↗

Synoviorthesis versus synovectomy in the treatment of recurrent haemophilic haemarthrosis: long-term evaluation.

The authors report a long-term evaluation of the effects of chemical and surgical synovectomies performed in two groups of patients which were comparable as regards number of haemarthrosis per year and joint mobility. The results obtained indicated that both synovectomy and synoviorthesis were effective in reducing the bleeding episodes; however, while synovectomy stopped almost completely the recurrence of haemarthrosis, synoviorthesis in 3 patients younger than 12 years did not modify it and in one case it even increased the bleeding tendency. Moreover, the occurrence of arthritic pain was observed in 6 knees treated by synoviorthesis and only in 3 knees treated by synovectomy. Finally, the joint function was significantly reduced in the synoviorthesis group as compared to the synovectomy group. In conclusion, synovectomy gave better results than synoviorthesis but the latter treatment has a number of economical and technical advantages and should therefore be considered in patients older than 12 year of age with good joint function and without evident radiological changes, in whom full dose replacement therapy has had no effect on the recurrence of haemarthrosis.

Adolescent↗

Enhanced antithrombotic mechanisms in patients with maturity-onset diabetes mellitus without thromboembolic complications.

Some haemostatic parameters have been evaluated in a group of rigorously selected patients with maturity-onset diabetes mellitus without thromboembolic complications and in apparently normal subjects of the same age before and after the venous occlusion test (VOT). In basal conditions diabetics had higher levels of AT III as biological activity and higher fibrinolytic and antifibrinolytic activities than controls. After VOT, F VIII R:Ag increased significantly in both groups, more markedly in controls than in diabetics, while F VIII: C showed no modification. Also AT III R:Ag increased after the test, but such variation was significant only in diabetics; on the contrary, the biological activity of AT III was always significantly decreased after the test. After VOT there were also in both groups highly significant increases in the fibrinolytic and antifibrinolytic activities. Finally, HbA1c levels directly correlated with AT III as biological activity before VOT, but with no other parameter either before or after the test. These data suggest the existence in patients with diabetes mellitus without thromboembolic complications of an activated protective mechanism against intravascular clotting.

Aged↗

Long-term effect of lithium on the uptake of 5-hydroxytryptamine by human platelets.

1 The content, uptake and storage of 5-hydroxytryptamine (5-HT) in platelets were determined in eight manic-depressive patients not on lithium (Li); in ten manic-depressive patients on Li; and in ten apparently normal persons as controls. 2 Platelets from the patients, whether or not on Li, contained less 5-HT than platelets from normal people. 3 5-HT uptake and storage by platelets from untreated patients were significantly lower than those of control subjects. 4 When patients had been on Li for 3 months or longer the diminished uptake and storage of 5-HT by their platelets were more than fully reversed. 5 Li added to platelet-rich plasma in vitro had no effect on the uptake of 5-HT by platelets.

Adult↗

Haemostasis during transvesical prostatic adenomectomy. A controlled trial on the effect of drugs with antifibrinolytic and thrombin-like activities.

Blood loss, plasma fibrinolytic activity, prothrombin, P.T.T., and fibrinogen plasma levels were measured in 30 patients subjected to transvesical adenomectomy. These parameters were evaluated during 7 consecutive days after the operation. Ten patients received the antifibrinolytic substance (AMCHA), ten patients received Bothrops Jararaca venom extract, and ten patients served as controls. The results show that the coagulating fraction of Bothrops Jararaca snake venom reduces intraoperative bleeding without influencing the haemostatic balance. Postoperative haematuria could be reduced by antifibrinolytic agents.

Aged↗