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Biomedical subjects

E Genton

Publications and source records attributed to E Genton.

At least 37 records · Page 2Linked to original sources
PubMed1981

Plasma and urine beta-thromboglobulin concentration in patients with deep vein thrombosis.

Plasma and urine beta-thromboglobulin (BTG) were measured in 52 patients with established deep vein thrombosis (DVT) and in 100 patients with clinically suspected DVT but with a negative venogram. Both plasma BTG (geometric mean 54: 95% range 12--239 ng/ml) and urine BTG (0.25; 0.03--3.1 ng/ml) were significantly elevated (p less than 0.005) in patients with DVT compared to symptomatic patients with a negative venogram (plasma BTG 32, 9--112 ng/ml; urine BTG 0.12, 0.02--0.58 ng/ml). Sensitivity (35%) and specificity (80%) of the plasma BTG assay for the diagnosis of DVT were low. The urine BTG assay had a sensitivity of 37% but a specificity of 100%. There was a significant correlation between plasma and urine BTG (r = 0.68, p less than 0.005). Serial BTG measurements were made in urine (40 patients) and plasma (20 patients) from high-risk neurosurgical cases who were screened with 125I-fibrinogen leg scanning and impedance plethysmography. BTG was elevated postoperatively and returned to normal within 2 or 3 days, but rose again in 10 patients in association with the development of DVT. The rise of BTG preceded the uptake of 125I-fibrinogen and lasted for only a few days. The return to normal of BTG was not related to treatment with anticoagulants. While measurement of BTG in plasma and urine is of limited value in the clinical diagnosis of venous thrombosis, the data indicate platelet activation occurs in venous thrombosis, but is maximal or perhaps limited to the initial phase of thrombus development.

Adolescent↗
PubMed1980

Beta-thromboglobulin radioimmunoassay. A laboratory characterization and evaluation.

Platelets release beta-thromboglobulin from alpha-granules when they are activated by various stimuli. An evaluation and optimization of a radioimmunoassay for beta-thromboglobulin is described. The optimum conditions for the reaction have been characterized, and the use of second antibody and polyethylene glycol allows completion of the assay within 24 hours. Similar BTG concentrations were obtained using a 1-hour non-equilibration assay but the 1-hour assay was inefficient for processing large volumes of specimens and has the potential for cross reactivity. BTG standards were unstable but the shelf-life was prolonged with aprotinin or by storage at -70 degrees C. Plasma BTG concentration in 80 normal individuals was 28 +/- 18 ng/ml. (mean +/- 2 S.D.).

Adult↗
PubMed1980

Venous thromboembolism associated with gynecologic surgery.

There are three effective means of prophylaxis against venous thrombosis in high-risk patients, including general surgical and gynecologic patients. Two of these are practical--low-dose heparin and external pneumatic calf compression. The results with dextran are currently equivocal, and its use has the disadvantage of requiring intravenous injection. Although oral anticoagulants are effective in reducing deep-vein thrombosis, significant bleeding occurs, limiting their usefulness. Platelet function-suppressing drugs have not proved to be sufficiently effective for general use.

Adult↗
PubMed1980

Management of venous thromboembolism.

Venous thromboembolism is a frequent cause of morbidity and mortality, especially in immobilized elderly patients. Once thrombosis exists, heparin is effective to arrest the process, and occasionally thrombolytic therapy with urokinase or streptokinase is indicated to accelerate lysis. Thrombosis may be prevented by one or a variety of prophylactic measures which should be applied in high-risk patients.

Aspirin↗
PubMed1980

The relevance of platelet and fibrin thromboembolism of the coronary microcirculation, with special reference to sudden cardiac death.

The coronary microcirculation was examined for platelet and fibrin thrombi in hearts from 21 normal subjects and 244 cardiac patients, including 168 with ischemic heart disease (IHD) and 76 with other types of heart disease. Seventy-seven cases were sudden cardiac death (SCD). No microthrombi were present in any of the normal hearts, whereas platelet and fibrin thrombin were present in the coronary microcirculation in 32 of 244 cardiac cases (13.1%), including 19 with IHD and 13 with other types of heart disease and after cardiac surgery. The microthrombi were either embolic or represented in situ thrombosis, depending upon the underlying pathologic process. There was no significant difference in the incidence of microthrombi in SCD patients, with IHD (10 of 50, 20%) compared with patients who survived longer (nine of 93, 10%). In SCD patients, however, platelet microthrombin were more frequent in patients less than 45 years of age compared with those older than 45 years of age (p = 0.0002). We concluded that coronary microcirculatory thrombi are not uncommon in heart disease. A subgroup of SCD in young patients with IHD has been identified in whom microcirculatory platelet thrombosis is the main cardiac pathologic process. The significance of this process is emphasized by the associated myocardial damage.

Adult↗
PubMed1979

Warfarin sodium versus low-dose heparin in the long-term treatment of venous thrombosis.

Acute deep-vein thrombosis is usually treated with intravenous heparin for a number of days, then with oral anticoagulants for weeks to months. We have compared adjusted-dose warfarin sodium with fixed low-dose subcutaneous heparin in the prevention of recurrent deep-vein thrombosis. Sixty-eight patients with acute deep-vein thrombosis confirmed by venography were treated with intravenous heparin and then randomized to secondary prophylaxis. Nine of 35 patients receiving subcutaneous heparin, but none of 33 receiving warfarin sodium, had new episodes of objectively documented venous thromboembolism (P = 0.001). Seven patients on warfarin sodium experienced bleeding complications (of which four were major), as compared with no patients receiving subcutaneous heparin (P less than 0.005). Thus, adjusted-dose warfarin sodium is more effective than low-dose subcutaneous heparin in preventing recurrent venous thromboembolism, but its use is accompanied by a significant risk of bleeding.

Acute Disease↗
PubMed1979

Plasma beta-thromboglobulin: differentiation between intravascular and extravascular platelet destruction.

To elucidate the usefulness of beta-thromboglobulin (beta TG) in the differentiation of the mechanism of thrombocytopenia, plasma beta TG concentration was measured in one patient with amegakaryocytic thrombocytopenia, four patients with autoimmune thrombocytopenia (ATP), two patients with thrombotic thrombocytopenia (TTP), and one patient with thrombocytopenia secondary to disseminated intravascular coagulation (DIC). Plasma beta TG was not measurable in amegakaryocytic thrombocytopenia, was normal in ATP, and was increased in TTP and DIC. These data indicate that in thrombocytopenic patients, increased plasma beta TG concentration may result from intravascular platelet consumption with release of platelet constituents in contrast to extravascular platelet destruction by the macrophage-monocyte system.

Adult↗
PubMed1978

Platelet-suppressant therapy in patients with coronary artery disease.

Platelets may contribute to the pathogenesis of atherosclerosis and to the complications of coronary atherosclerosis, acute myocardial infarction, unstable angina, and sudden cardiac death. In addition, platelets may contribute to saphenous vein aortocoronary graft occlusion. Of 104 men with coronary artery disease, platelet survival (SURV) (chromium51 labeling) was shortened in 68% (3.1+/-0.03 days [average+/-SEM]; normal, 3.7+/-0.03 days; P greater than .001). Three platelet-suppressant drugs, sulfinpyrazone, clofibrate, and dipyridamole increased SURV. Saphenous vein graft occlusion was associated with shortened SURV. Of 36 men with occlusion of at least one graft, SURV was shortened in 35 (2.5+/-0.08 days), whereas in 19 with all grafts open, SURV was shortened in six (3.5+/-0.10 days; P less than .01). These drugs increased SURV (2.3 +/- 0.08 to 2.7 +/- 0.11 days; P less than 0.1) and were associated with improved graft patency (four of 32 grafts after initial bypass vs 30 of 34 grafts open after second operation).

Adult↗
PubMed1978

Platelet survival determination in atherosclerosis.

Platelet survival presently represents a useful method for the study of atherosclerosis and its consequences in patients and in animal models. The currently used technique, while time consuming, appears to be reliable and reproducible for the measurement of platelet survival and turnover rate. The test offers promise to detect and perhaps quantify the degree of active vessel wall damage. In addition, it might prove useful to identify drugs with potential as platelet suppressants. Finally, the test might be used to compare with new techniques developed or used to identify vessel damage or thrombosis proneness.

Animals↗
PubMed1978

Cardiac thromboembolism: evidence for role of platelets and value of platelet suppressant therapy.

Thromboembolism remains a frequent and serious problem in cardiac patients. Methods to identify the thrombosis prone patient and the identification of safe and effective forms of treatment would be of great value. The accumulating evidence which indicates that abnormalities in platelet tests are often present in cardiac patients and may help identify those at greatest risk of thrombosis is encouraging. It suggests that patients with cardiac disease are desirable groups for investigation. It also indicates that the platelet survival test may be useful as a reference against which new and more practical tests can be compared, as well as a means to identify useful platelet suppressant drugs or to monitor the effects of these drugs.

Aspirin↗
PubMed1977

Cardiac thromboembolism: evidence for role of platelets and value of platelet suppressant therapy.

Thromboembolism remains a frequent and serious problem in cardiac patients. Methods to identify the thrombosis-prone patient and the identification of safe and effective forms of treatment would be of great value. The accumulating evidence which indicates that abnormalities in platelet tests are often present in cardiac patients and may help identify those at greatest risk of thrombosis is encouraging. It suggests that patients with cardiac disease are desirable groups for investigation. It also indicates that the platelet survival test may be useful as a reference against which new and more practical tests can be compared, as well as a means to identify useful platelet suppressant drugs or to monitor the effects of these drugs.

Blood Platelets↗
PubMed1977

Platelet survival time in patients with hypoxemia and pulmonary hypertension.

Platelet survival time (autologous labeling with 51chromium) was measured in 63 patients in order to evaluate the role of platelets in the thromboembolic complications of patients with hypoxemia and pulmonary hypertension. Thirty-eight of these patients had chronic obstructive airways disease; 13, primary pulmonary hypertension; seven, recurrent pulmonary embolism; four, the Eisenmenger syndrome; and one, multiple pulmonary arteriovenous fistula. Forty-three patients were hypeakly associated with arterial oxygen tension ( r = 0.50), but not with the arterial carbon dioxide tension or the level of pulmonary artery pressure. Sulfinpyrazone lengthened platelet survival in 12 of 24 (50%) treated patients but this drug did not alter either arterial oxygen tension arterial carbon dioxide tension, or pulmonary artery pressure. Our results suggest that hypoxemia is associated with shortened platelet survival time and that platelets may, therefore, be involved in the thromboembolic complications that develop in patients with hypoxemia.

Blood Platelets↗