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Biomedical subjects

A Estelles

Publications and source records attributed to A Estelles.

At least 19 recordsLinked to original sources
PubMed2006

Expression of the fibrinolytic components in endometriosis.

Endometriosis is a benign gynaecologic disease defined as the presence of endometrial tissue outside the uterus. This tissue has the ability to implant at ectopic sites, such as ovary and peritoneum, where a local extracellular proteolysis might take place. An altered expression of several components of the fibrinolytic system in the endometrium and peritoneal fluid of women with the disease has been suggested as a key factor in the establishment of the endometriotic lesions. There is evidence of increased fibrinolytic activity in the eutopic endometrium of these women, resulting in endometrial fragments with a high potential to degrade the extracellular matrix and facilitate implantation. Proteolytic status is determined by the imbalance between plasminogen activators and plasminogen activator inhibitors, which are expressed differently depending on the type of lesion considered and the stage of the disease. The aim of the present study is to review the expression of the plasminogen activator system in endometriosis, and to consider the clinical implications and the possible further research efforts in this disease.

Endometriosis↗
PubMed2000

Epidermal growth factor receptor dimerization monitored in live cells.

We present a method for monitoring receptor dimerization at the membrane of live cells. Chimeric proteins containing the epidermal growth factor (EGF) receptor extracellular and transmembrane domains fused to weakly complementing beta-galactosidase (beta-gal) deletion mutants were expressed in cells in culture. Treatment of the cells with EGF-like compounds for as little as 15 s resulted in chimeric receptor dimerization detectable as beta-gal enzymatic activity. The dose response of chimeric receptors was ligand specific. beta-galactosidase complementation was reversible upon removal of ligand and could be reinduced. Antibodies that block ligand binding inhibited receptor dimerization and beta-gal complementation. These results demonstrate that beta-gal complementation provides a rapid, simple, and sensitive assay for protein interactions and for detecting and monitoring the kinetics of receptor dimerization.

Animals↗
PubMed1993

A quantitative ELISA for the measurement of complexes of prostate-specific antigen with protein C inhibitor when using a purified standard.

The serine protease inhibitor protein C inhibitor is present in semen at a relatively high concentration and forms in vivo complexes with two plasminogen activators also present in semen, urokinase-type and tissue-type plasminogen activators. Therefore, the fact that prostate-specific antigen (PSA), a major prostate enzyme, complexes and inactivates protein C inhibitor (PCI) in semen could have implications in human reproduction. The present study was undertaken to develop an enzyme-linked immunosorbent assay (ELISA) for complexes of PSA with PCI (PSA:PCI) with purified PSA:PCI complexes as a standard. Seminal plasma was utilized as the starting material for purification of complexes by affinity chromatography on heparin-Sepharose and gel filtration. The final preparation contained equimolar concentrations of PSA and PCI and was used for calibration of an ELISA for PSA:PCI complexes involving polyclonal anti-PSA and horseradish peroxidase-labeled anti-PCI antibodies. The ELISA had a detection limit of about 0.2 ng/ml of complex and was specific for PSA:PCI complexes because no color was developed at PSA or PCI concentrations up to 100 microgram/ml. Normal plasma or plasma from patients with prostate carcinoma who had high PSA levels had no detectable PSA:PCI complexes. Seminal plasma from voluntary donors collected in the absence of inhibitors and incubated at room temperature for at least 3 hours had PSA:PCI complex levels ranging from 30 to 46 micrograms/ml, accounting for up to 34% of the total PCI in seminal plasma.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1991

Interaction of plasma kallikrein with protein C inhibitor in purified mixtures and in plasma.

The interaction between plasma kallikrein (KK) and protein C inhibitor (PCI) and the influence of KK on the complex formation between activated protein C (APC) and PCI was studied in purified systems as well as in plasma in order to assess the significance of these reactions in the plasma milieu. PCI complexed to KK (KK:PCI) or to APC (APC:PCI) was measured by sandwich ELISA's using antibodies directed against each protein in the complexes. The formation of KK:PCI complexes assayed by this method paralleled the inhibition of KK amidolytic activity by PCI in purified system. Incubation of normal plasma (NHP) at 4 degrees C, which can induce prekallikrein activation due to cold activation, resulted in PCI inactivation and appearance of KK:PCI complexes. PCI activity fell to 35% of the NHP and 1.2 micrograms/ml of KK:PCI complex was formed. However, incubation of NHP at room temperature or of prekallikrein deficient plasma at 4 degrees C did not result in significant decrease of PCI activity. Thus the PCI inactivation was associated with prekallikrein activation and complexation to PCI following cold activation. Incubation of exogenous purified KK with NHP resulted in PCI inactivation and complexation with KK in a temperature-dependent manner. Addition of 2.8 micrograms/ml KK to plasma at 4 degrees C resulted in the inactivation of 55% of plasma PCI and the formation of 0.9 microgram/ml KK:PCI which represents 21% of the KK added, whereas at 37 degrees C PCI was inactivated to 30% and only 0.30 microgram/ml KK:PCI complexes were measured. These results indicate that PCI is a major KK inhibitor at 4 degrees C.(ABSTRACT TRUNCATED AT 250 WORDS)

Antibodies, Monoclonal↗
PubMed1990

[Plasminogen deficiencies in 2 Spanish families. Response to the administration of DDAVP].

We describe two families with heterozygous plasminogen deficiency. In the first the patient was a 27 year-old female who suffered an acute episode of ischemic cerebrovascular disease affecting the left temporal lobe documented by arteriographic, gammagraphic and CAT studies. She had no family history of thrombotic conditions. In the other family the propositus was a 31 year-old man with spontaneous deep venous thrombosis in the left leg. His father was also symptomatic, with a history of recurrent thrombotic complications after predisposing factors, that included multiple venous thrombosis and a pulmonary embolism. Laboratory data showed normal hemostasis test results. Antigenic and functional levels of protein C, protein S and antithrombin III were within normal limits. The only abnormality found was decreased plasminogen activity in plasma; antigenic and functional levels were reduced to about half-normal levels. In both cases crossed immunoelectrophoresis revealed a normal migration pattern of plasminogen. Thus, we conclude that our patients were carriers of congenital hypoplasminogenemia or familial type I plasminogen deficiency, due to decreased synthesis. We also reported on fibrinolytic response to infusion of DDAVP, a synthetic analogue of the antidiuretic hormone. Fibrinolytic activity was normal in basal conditions as well as in response to DDAVP infusion.

Adult↗
PubMed1988

Physiological coagulation inhibitors (protein S, protein C and antithrombin III) in severe preeclamptic states and in users of oral contraceptives.

Protein C, protein S and antithrombin III were evaluated in normal pregnancy, severe preeclampsia and chronic hypertension with superimposed severe preeclampsia. The same study was performed on a group of 10 normal women using oral contraceptives. In normal pregnancy a significant decrease in the level of free and total PS was observed in the 2nd trimester of pregnancy and was sustained throughout the remaining months. No significant changes in the levels of protein C and antithrombin III were observed during normal pregnancy. In preeclamptic states a significant decrease in protein C was observed. It was more evident in severe preeclampsia when compared with the normal pregnancy group at similar gestational age. No statistically significant differences in protein S were found when the normal and pathological groups were compared. Antithrombin III decreased only slightly in the severe preeclamptic group. The decrease in protein C and antithrombin III levels in severe preeclampsia could be related with the microthrombotic state that these patients may present. However, the role played by protein S, which decreases during normal pregnancy and in preeclampsia, is not clear. A decrease in the level of total protein S was observed in the group of women using oral contraceptives. No significant changes in protein C and antithrombin III levels were observed in this group.

Adult↗
PubMed1985

Abruptio placentae and disseminated intravascular coagulation.

Several parameters of hemostasis have been studied in 19 patients suffering from abruptio placentae. In 10 of them severe hemostatic alterations were detected and in 5, disseminated intravascular coagulation was observed. The patients were divided into four groups according to the severity of their clinical picture. The degree of placental separation was related to the severity and course of the clinical history and to the alterations in hemostasis detected at the most critical clinical moment. The analytical parameters were evaluated after extraction of the thromboplastic material. A good correlation was observed between the severity of the clinical picture and the degree of placental separation and the greatest analytical alteration, especially with cross-linked soluble fibrin monomer complexes (SFMC). In 9 of the 19 patients who showed analytical and/or clinical alterations, an improvement was detected in these alterations after evacuation of the uterus.

Abruptio Placentae↗
PubMed1982

Evaluation of the soluble fibrin monomer complexes and other coagulation parameters in obstetric patients.

The soluble fibrin monomer complexes (SFMC) in 154 obstetric patients with possible disseminated intravascular coagulation (DIC) were evaluated in SDS polyacrylamide gel electrophoresis (PAGE) after precipitation with B-alanine. Other coagulation tests were performed on these patients. The patients were classified into three groups: A) patients with a clinical history of DIC (6 cases); B) patients with only the analytical alterations of DIC (35 cases); and C) patients who showed pathological obstetric diagnoses but without a clinical nor analytical history of DIC (113 cases). In the three groups, well-defined bands of less electrophoretic mobility than fibrinogen were obtained. A significant increase in the second electrophoretic band was found in group A (5.1 per cent) when compared to group C (0.5 per cent). The second electrophoretic band appeared in greater proportion in the group of patients with an unfavorable clinical evolution.

Abruptio Placentae↗
PubMed1982

Factor XII-induced fibrinolysis. Diminished proactivator activity and drastic reduction of activator activity in Fletcher factor-deficient plasma gamma globulin.

Fibrinolytic studies in gamma G fractions of three Fletcher factor-deficient plasmas (functionally deficient in prekallikrein) revealed weak or no factor XII-independent activator activity. Two of the three Fletcher trait patients showed no plasminogen activator activity in clot lysis, fibrin plate, and amidolytic assays. The third patient showed no activator activity as determined by clot lysis and amidolytic assays but gave 10% of the activator activity detected in normal undiluted gamma G fraction in absence of HFf when determined by fibrin plate assay. Normal plasma gamma G fractions showed detectable and significant plasminogen activator activity. These fractions did not contain kallikrein or activated factor XI activities, thus indicating that the activator activity could not be attributed to the presence in these fractions or trace of these activated factors. Furthermore, factor XI-deficient plasma gamma G fraction, which was shown to contain no activated prekallikrein, showed normal plasminogen activator activity. Finally, specific antibodies to prekallikrein were shown not to quench the activity of plasminogen activator present in normal plasma gamma fraction. A double genetic deficiency to explain the absence in Fletcher factor-deficient plasma gamma G fractions of both prekallikrein proactivator and activator activities is not likely. Thus plasma prekallikrein, besides being a known plasminogen proactivator, appears to be required for the expression of a plasminogen activator activity.

Electrophoresis, Polyacrylamide Gel↗
PubMed1980

Dysfunctional plasminogen in full-term newborn.

Full-term newborns (FTN) plasminogen was evaluated by different techniques (affinity chromatography, immunologic technique, casein method, and chromogenic substrate). The functional activity of the FTN plasminogen was about 50% of that of the adult. This suggests the possible existence of a functional anomaly of plasminogen in FTN. FTN plasminogen aminoacids were studied, and, besides small qualitative anomalies, a decrease in amino acid residues per mole of protein and a different N-terminal amino acid were detected.

Adult↗
PubMed1978

Alterations in the coagulation and fibrinolysis system in pregnancy, labour and puerperium, with special reference to a possible transitory state of intravascular coagulation during labour.

Various tests of hemostasis were carried out during pregancy, labour and the puerperium in a group of 259 women. Determinations were carried out in the 1st, 2nd and 3rd trimesters, in the period of dilatation, the expulsion period, the period of expulsion of the placenta and the immediate postpartum period of labour and on each of the first 5 days of the puerperium. It was confirmed that during pregnancy there is an elevation of the fibrinogen degradation products (FDP) levels with a proportional increase in the numbers of positive protamine sulfate and ethanol tests. The proportion of positive protamine sulfate and ethanol tests reaches a maximum in the expulsion of the placenta coinciding with the presence of soluble complexes heavier than fibrinogen as detected by polyacrylamide gel electrophoresis and by column chromatography. All this indicates that there is a transitory intravascular coagulation produced during labour reaching its maximum at the time of birth and tending to become normalized in the first few days of the puerperium.

Blood Coagulation↗
PubMed1976

Changes in human amniotic fluid fibrinolytic inhibitor levels during pregnancy.

The amniotic fluid (AF) when incubated with the patient's own plasma diminishes the lytic activity of the plasma. It is suggested that this inhibition is due to the presence of fibrinolytic inhibitors in the AF. The inhibitors rate increases as pregnancy advances. Evaluating these inhibitors in a group of 65 women before and after the 38th week of pregnancy, a higher rate of fibrinolytic inhibitors is found after the 38th week. The said differences are statistically significant. For the moment it does not seem that the increasing of the inhibitors in the last part of pregnancy might be used as a fetal maturity test.

Amniotic Fluid↗
PubMed1976

Streptokinase resistance test in a group of Mediterranean people and its possible variations as regards sex and age.

A streptokinase resistance test (SK-RT) was studied on a group of people from the Mediterranean coast of Spain. It was found that 87.5% of the studied population required a dose of 250,000 U or less to obtain an adequate neutralization of the circulating antibodies. In none of the cases was the required dose higher than 500,000 U. The average dose was of 132,969 U (SD = 102,269). No significant differences were found between the dose required for men and that required for women. A significantly inferior dose to the average was, however, required for people over 50 years old (x = 112,280, SD = 100,459).

Adolescent↗