indium-oxine and Arteriosclerosis

Topics: Adult; Aged; Arteriosclerosis; Endothelium, Vascular; Humans; Indium Radioisotopes; Leukocytes, Mononuclear; Male; Middle Aged; Organometallic Compounds; Oxyquinoline; Radionuclide Imaging

In the present study the prevalence of active atherosclerotic lesion sites in the carotid and femoral arteries as well as the platelet survival in a selected group of 33 patients (8 males, 25 females) below the age of 50 after juvenile stroke has been examined. In the patients studied a high frequency (80%) of positive (visible) carotid artery lesions with a platelet uptake ratio (PUR) ranging from 1.07-1.79 as well as an extremely shortened platelet survival were monitored. In-vitro platelet function tests, however, did not show significant abnormalities. No correlation between PUR, platelet survival, platelet function and the clinical situation could be assessed. These findings indicate that in this highly selected group of patients in-vivo haemostatic balancing seems to be severely impaired.

Topics: Adult; Arteriosclerosis; Aspirin; Blood Platelets; Carotid Arteries; Carotid Artery Diseases; Cell Survival; Cerebral Arteries; Cerebrovascular Disorders; Female; Hemostasis; Humans; Indium Radioisotopes; Male; Middle Aged; Organometallic Compounds; Oxyquinoline; Platelet Function Tests; Radionuclide Imaging; Risk Factors

In this study we have assessed the deposition of 111-In-oxine-labelled platelets--using a dual radiotracer method--at angioplasty sites of the lower extremities in 20 patients (14 male, 6 female; median age: 60 years) with ASA (1.0 g/day)-therapy. The platelet survival time (PST)--using the multiple hit model--was evaluated before and after percutaneous transluminal angioplasty, and we also measured the plasma levels of beta-thromboglobulin (beta-TG) and platelet factor 4 (PF 4) before and after PTA. Before PTA, scintigraphy was positive in only one patient, while 24 hours after PTA a positive scintigraphic result was observed in 16/20 patients. The median target/non target-ratio was 1.0 (0.66-1.3) before PTA, and this ratio increased significantly (p less than 0.0005) to 1.53 (1.0-3.3) after PTA. The median PST decreased significantly (185.0 hours before PTA----145.2 hours after PTA; p less than 0.001), while the median platelet turnover increased from 34,000/microliter/day to 47,900/microliter/day (p less than 0.01). The median plasma levels of the platelet specific proteins increased significantly immediately after PTA (p less than 0.001), but one day later they were not significantly different from the pretreatment values. The quantitative methods used in this study seem a valuable tool to evaluate the effects of different therapeutical--especially antiplatelet--interventions after PTA in humans, thus helping to find the best antithrombotic regimen for this widely used therapeutical procedure.

Topics: Adult; Aged; Angioplasty, Balloon; Arteriosclerosis; Aspirin; beta-Thromboglobulin; Blood Platelets; Cell Survival; Female; Humans; Indium Radioisotopes; Male; Middle Aged; Organometallic Compounds; Oxyquinoline; Platelet Adhesiveness; Platelet Factor 4

The fact that prostacyclin is able to preserve platelets in-vitro stimulated the question whether platelets being treated in presence of prostacyclin might behave different after reinjection in human. We therefore studied the effect of synthetic PG12 in-vitro, being added immediately after blood sampling. It is demonstrated that the presence of prostacyclin does not change the labelling efficiency and in-vitro viability beside the alterations induced by this compound itself, however, it results in a significantly improved recovery. Furthermore, the platelet half-life in the patients as well as the deposition of the radiolabelled platelets on active human atherosclerotic lesions does not seem to be affected. Thus, the addition of PGI2-improves cellular viability during the preparation without negatively interfering with the in-vitro and in-vivo results later on. Thus, the use of PGI2 can be strongly recommended.

Topics: Aged; Arteriosclerosis; Blood Platelets; Blood Preservation; Epoprostenol; Female; Half-Life; Humans; Indium Radioisotopes; Isotope Labeling; Male; Middle Aged; Organometallic Compounds; Oxyquinoline; Platelet Aggregation; Radioisotopes

Using 111indium oxine and 111indium oxine sulphate as platelet labels, maximal labelling efficiency can be achieved already after 3 minutes at an incubation temperature of 37 degrees C. Mean labelling efficiency values of about 90% are reached at a platelet count of greater than 10(9) platelets/ml, but the labelling efficiency is satisfactory also at a rather low platelet count of about 10(6) platelets/ml (71% on average). Platelet labelling with these tracers allows the calculation of platelet half-life in vivo, and gamma-camera imaging of platelet aggregates in thrombosis and renal transplant rejection as well. In the present study, the platelet half-life is significantly shortened in patients with coronary heart disease (n = 15), peripheral vascular disease (n = 13) and primary hyperlipoproteinaemia (n = 32) in comparison with 106 controls. No age dependence of platelet half-life was found in the different groups of patients whereas in the control group, a significant negative correlation between age and platelet half-life was observed.

Topics: Adult; Age Factors; Aged; Arteriosclerosis; Blood Platelets; Coronary Disease; Half-Life; Humans; Hydroxyquinolines; Hyperlipoproteinemias; Indium; Isotope Labeling; Methods; Microscopy, Electron, Scanning; Middle Aged; Organometallic Compounds; Oxyquinoline; Radionuclide Imaging

A new dual isotope scintigraphic (DISC) examination of the carotid arteries consisting of simultaneous injections of 111In-labeled platelets and 99mTc-labeled red cells was performed on eight male patients suffering from amaurosis fugax attacks. In concordance with the angiographically proven high percentage of significant extracranial carotid disease in patients with amaurosis fugax, six of the eight patients examined had an increased platelet accumulation in the carotid artery clinically affected. In one patient with normal angiography and one amaurosis fugax attack the platelet scintigraphy even revealed a pathological platelet accumulation in the ipsilateral carotid artery. These findings confirm the hypothesis that most amaurosis fugax attacks are due to arterio-arterial emboli originating from atherosclerotic plaques of the carotid bifurcation.

Topics: Aged; Arteriosclerosis; Blindness; Carotid Artery Diseases; Carotid Artery Thrombosis; Carotid Artery, External; Carotid Artery, Internal; Cerebral Angiography; Constriction, Pathologic; Humans; Indium; Ischemic Attack, Transient; Male; Middle Aged; Organometallic Compounds; Oxyquinoline; Radionuclide Imaging; Serum Albumin; Technetium Tc 99m Aggregated Albumin; Tin; Tin Compounds

Platelet labeling with 111-In-oxinesulfate allows visualization of platelet deposition in the vascular bed. Scintigraphic studies were performed in 6 patients with "active" (PUR greater than 1.20) and 8 patients with "inactive" (PUR less than 1.20) atherosclerotic lesions of the femoral artery. Platelet deposition was also studied in 11 patients with implanted prosthetic vascular grafts and in 21 patients with an abnormal aneurysm of the aorta. Infusing 5 ng/kg/min PGI2 during 6 hours for 5 days into patients with "active"-atherosclerosis and aneurysms of the aorta resulted in a significant decrease of platelet deposition even after having stopped the infusion. There was no influence of PGI2 on PUR in patients with "inactive" lesions. The group of patients with implanted prosthetic grafts demonstrated also a significant decrease of PUR values during the PGI2-infusion, but reached baseline values soon after stopping the infusion. When platelet deposition is increased gamma-camera imaging provides valuable date on the influence of any kind of therapy on the in-vivo platelet function.

Topics: Aorta, Abdominal; Aortic Aneurysm; Arteriosclerosis; Blood Platelets; Epoprostenol; Humans; Indium; Organometallic Compounds; Oxyquinoline; Radioisotopes; Radionuclide Imaging