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Biomedical subjects

I Alberca

Publications and source records attributed to I Alberca.

At least 37 records · Page 2Linked to original sources

Normal pregnancy in a patient with a postpartum factor VIII inhibitor.

A patient who had developed a VIII:C IgG-Kappa antibody after her first delivery became pregnant for a second time. At that time the titer of the inhibitor had increased fourfold, remaining at high levels throughout the rest of the pregnancy. The neonate exhibited an inhibitor with characteristics identical to that of the mother which could not be detected 3 months after birth. No hemorrhagic complications in either of the subjects were observed.

Adult↗

Effect of hemodialysis on protein C levels.

The immunological functions of antithrombin III and protein C were studied in 8 patients before, during and after hemodialysis. After dialysis a significant decrease in protein C and antithrombin III levels was seen. The changes observed in both proteins after hemodialysis should be considered as a component in the genesis of the hypercoagulation state in these patients.

Adult↗

Lupus anticoagulant and false positive serological tests for syphilis.

A 41-year old male who presented for blood donation for the first time was rejected on the grounds of a positive reaginic serological test (VDRL and RPR) and a specific antitrepomena test (FTA) for syphilis. Later studies revealed the existence of a lupus anticoagulant and this was made responsible for the positive serology. Our observation suggests the need to search for the existence of a lupus anticoagulant in blood donors with non-specific or specific positive antitrepenema test.

Adult↗

Detection of anomalies in cell-surface carbohydrates on thrombasthenic platelets using 125I-labeled lectins.

The composition of carbohydrates on the surface of platelets from a patient with Glanzmann's thrombasthenia and from seven normal donors were determined and compared. To this end, binding studies were performed using nine different purified 125I-labeled lectins; Concanavalin A, P-Phytohaemagglutinin, Wheat Germ Agglutinin, Dolichos biflorus, Pisum sativum, Ricinus communis II Agglutinin, Tetragonolobus purpureus, Lens culinaris and Soybean Agglutinin. These studies show that thrombasthenic platelets bear significantly decreased numbers of receptors for Concanavalin A and Lens culinaris, both with a specificity for D-mannose, and Ricinus communis II, with specificity for D-galactose. There were no detectable differences in the numbers of other lectin receptors. These results provide further evidence of molecular defects in thrombasthenic platelets. Moreover, the use of 125I-labeled lectins, as shown here, provides a fast and reliable technique for identifying abnormalities in the carbohydrate composition on the surface of platelets in various thrombopathies.

Blood Platelet Disorders↗

Activation of kinin-prekallikrein system after infusion of factor VIII concentrates in hemophilic patients.

Possible changes in the kinin-prekallikrein system after infusion of factor VIII concentrate were studied in seven patients with severe hemophilia. The functional and immunological activities of factors XI and XII, prekallikrein, high molecular weight kininogen, and C-1-esterase inhibitor were measured before and at 0.5, 2, 6, and 12 hours after infusion of 50 U/kg of factor VIII concentrate. A significant decrease (P less than 0.05) in the functional and immunological activities of prekallikrein was observed at 0.5 and 2 hours after factor VIII administration. The other proteins did not change. The results suggest that the kinin system is activated after infusion of high doses of factor VIII concentrate, although clinical evidence of such activation by these changes was not detected.

Antigens↗

Controlled trial of desmopressin in liver cirrhosis and other conditions associated with a prolonged bleeding time.

The synthetic vasopressin derivative desmopressin (DDAVP) shortens a prolonged bleeding time (BT) in patients with uremia, congenital platelet dysfunction, and von Willebrand disease. To establish the limits of the clinical usefulness of DDAVP, a controlled randomized study was carried out in 53 patients and ten volunteers with different conditions that have in common a prolonged BT. DDAVP significantly shortened the BT in 21 cirrhotics (P less than .01), in eight patients with unclassified prolonged BT (P less than .05) and in ten volunteers taking the antiplatelet drugs aspirin (P less than .05) and ticlopidine. The BT changes were not statistically significant in 15 patients with severe thrombocytopenia nor in nine with congenital platelet dysfunction, even though a few patients with storage pool deficiency responded with a marked BT shortening. Our findings indicate that DDAVP might be given when biopsies or other surgical procedures must be carried out in patients with prolonged BT. However, the compound is often ineffective in patients with thrombocytopenia or congenital platelet dysfunction.

Adolescent↗

New congenital deficiency of high molecular weight kininogen and prekallikrein (Fitzgerald trait). Study of response to DDAVP and venous occlusion.

The prolonged partial thromboplastin time observed in the plasma of a 36 year old asymptomatic man was related to the reduced prekallikrein activities (coagulant; antigenic; and amidolytic) and the absence of coagulant and immunologic activities of high molecular weight kininogen (HMWKg). The patient's plasma also exhibited impaired surface-mediated fibrinolysis and impaired generation of kallikrein. The coagulation defect was identified as the "Fitzgerald trait". The levels of CH50, C2, C4 and C-1 inactivator were normal. Venous occlusion in the patient gave rise to a normal release of extrinsic plasminogen activator from the vascular endothelium. The administration of DDAVP led to a FVIII/VWF response which was similar to that obtained in healthy subjects. No alteration could be observed in the contact phase proteins after DDAVP administration.

Adult↗

Protein C deficiency--response to danazol and DDAVP.

We studied a Spanish family in which one of the female members presented recurrent thrombophlebitis in both legs after three different deliveries. Biological and antigenic activity of protein C was decreased (35% and 42% respectively). Reduced protein C levels were also observed in 6 other family members. Administration of danazol (600 mg/day) in two patients with protein C deficiency elevated this protein and discontinuation of the drug resulted in a reduction of protein C to pretreatment values. The proposita showed a normal fibrinolytic activity and infusion of DDAVP produced a similar response of FVIII/VWF and plasminogen activator to those observed in healthy subjects.

Antithrombin III↗