I. F. Lane

Radiolabeled platelets in detecting the source of recurrent pulmonary emboli. A case report

Multiple pulmonary emboli are recognized to be the cause of progressive pulmonary failure. In these patients, the source of emboli may be difficult to detect, even by venography. The authors describe the use of autologous Indium 111-labeled platelets to locate the origin in a patient with progressing right heart failure.

The Diagnosis of True and False Aneurysms With 111-Indium Labelled Platelets

Thrombus formation within arterial aneurysms may lead to embolisation and distal ischaemia. We have investigated the use of 111-indium labelled plate lets in the diagnosis of atherosclerotic and false aneurysms. Autologous platelets labelled with 111-indium oxine were injected into patients with eleven proven aneurysms (8 atherosclerotic, 3 false) . Gamma camera imaging performed be tween 24 and 72 hours later was positive for 10 of the aneurysms. In every case there was increased uptake of label over the aneurysm when compared to undis eased blood vessels (p < 0.05). Most aneurysms could be demonstrated within 24 hours of labelling platelets. 111-indium labelled platelets may prove useful in identifying the source of peripheral arterial emboli.

Assessment of Platelet Inhibitory Therapy for Arterial Prostheses in an in Vivo Canine Model

Platelet inhibitory therapy has applications in vascular surgery and in patients who have coronary and cerebral vascular disease1. Screening of new products to assess their ethicacy involves measurement of platelet aggregation responses to standard aggregants2 the use of artificial circuits3 and clinical trials, which are time consuming and expensive. The frequent side-effects found with the standard platelet inhibitory therapy of aspirin combined with dipyridamole4 has led for a search for new compounds. We have developed an in vivo canine model which is used to identify effective compounds on the basis of the rate of platelet accumulation and subsequent thrombosis on artificial arterial prostheses. We describe this model and its use to evaluate a new reversible cyclo-oxygenase inhibitor, indobufen (Farmitalia Carlo Erba).

The Effect of Surgical Dressings on Skin Temperature

Infection of surgical wounds leads to delaying healing, incisional herniation and occasionally to fatal septic complications. Contamination by micro-organisms at the time of surgery is prevented by an aseptic operating environment. Postoperatively, wounds are dressed to reduce entry of bacteria such as Staphyloccoci aureus and Eschericia coli which occur naturally as skin commensals.

The Influence of Thromboxane Receptor Blockade on Platelet Uptake in Dacron Grafts in Man

Human prosthetic vascular grafts do not sustain a growth of endothelium on the luminal surface and remain thrombogenic indefinitely1. Whilst large diameter aortic grafts develop a thin layer of platelet thrombus as pseudointima, smaller prostheses such as those in the femoro-popliteal position have a thrombosis and occlusion rate approaching 60% at 1 year after implantation2. Platelet inhibitory therapy is established in the prevention of thrombosis but the combination of aspirin plus dipyridamole produces frequent gastro-intestinal side effects. This has been shown in the recent Persantin Aspirin Re-infarction Study3 where 25% of patients had to discontinue aspirin therapy. Thromboxane A2 (TXA2) which is a product of aracidonic acid metabolism, is a powerful stimulator of platelet aggregation4. It is produced by enzymes including cyclo-oxygenase and thromboxane synthetase in platelets and the natural biological opponent of TXA2 is prostocyclin (PGI2).