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Biomedical subjects

J Aznar

Publications and source records attributed to J Aznar.

At least 73 records · Page 4Linked to original sources

Fibrinolytic activity and protein C in preeclampsia.

Various parameters of the fibrinolytic system and antigenic and functional protein C and its inhibitor were studied during normal pregnancy and in patients with preeclampsia. The fast acting tissue-type plasminogen activator inhibitor level was found to increase progressively during normal pregnancy. This increase was more evident in cases of severe preeclampsia (p less than 0.05). No variations were observed in protein C levels in normal pregnancies but a reduction in protein C level was noted in patients with severe preeclampsia (p less than 0.01). In preeclampsia, the protein C inhibitor level was higher than in normal pregnancy; it was also higher in normal pregnancy when compared to the control group.

Adult

Fibrinolytic study in a homozygous protein C deficient patient.

The fibrinolytic system was evaluated in a patient with homozygous protein C deficiency as well as in several members of his family with a partial deficiency of this protein. Before anticoagulant therapy the patient showed skin lesions which quickly disappeared after administration of fresh plasma. After anticoagulant treatment, the propositus suffered two clinical episodes of "ecchymotic" lesions, which were controlled with fresh plasma. The patient has remained free of new lesions and other clinical episodes up to the present date. The fibrinolytic activity of both the propositus and his family was normal. The patient's father showed adequate release of tissue plasminogen activator after controlled physical exercise. According to clinical and analytical data from our patient and his family, it is suggested that, in spite of the preservation of the fibrinolytic system in this case, a localized deficiency in fibrinolysis could exist in view of the clinical behaviour of the skin lesions described.

Anticoagulants

Effect of oral contraceptives on plasma and platelet lipid composition. Influence of the length duration of time of ingestion.

The action of oral contraceptives (OC) (50 micrograms ethinylestradiol +250 micrograms levonorgestrel) on plasma and platelet lipid composition was studied in two groups of women who took this OC for one year, or for a longer period of time (2-9 years). Comparison with the control group showed that the ingestion of OC modifies the composition of some fatty acids in plasma and platelets. This modification is more marked in the women who took OC for one year. In plasma a decrease in linoleic acid (18:2) was found in the cholesterol and phospholipid fractions. In platelets, an increase of stearic acid (18:0) was observed in phospholipids, triglycerides and free fatty acid fractions. The modifications observed in plasma and platelets were not parallel, which suggests a specific and different action of OC on both plasma and platelets. Finally, it is suggested that the lipid variations found in the group that took the OC for one year may be compatible with a platelet hyperfunction.

Adult

Early platelet-collagen interactions in whole blood and their modifications by aspirin and dipyridamole evaluated by a new method (BASIC wave).

It is shown that the supernatant of unstirred whole blood at 37 degrees C, stimulated by 1 microgram/ml of collagen for 10 sec, produces a rapid generation of pro and antiaggregatory compounds with a final proaggregatory activity which can be detected for more than 60 min on a platelet rich plasma (PRP) by turbidometric aggregometry. A reversible aggregation wave that we have called BASIC wave (for Blood Aggregation Stimulatory and Inhibitory Compounds) is recorded. The collagen stimulation of unstirred PRP produces a similar but smaller BASIC wave. BASIC's intensity increases if erythrocytes are added to PRP but decreases if white blood cells are added instead. Aspirin abolishes "ex vivo" the ability of whole blood and PRP to generate BASIC waves and dipyridamole "in vitro" significantly reduces BASIC's intensity in whole blood in every tested sample, but shows little effect in PRP.

Adult

Reduced fibrinolytic activity in coronary heart disease in basal conditions and after exercise.

Fibrinolysis may be impaired in coronary heart disease patients. 20 coronary heart disease patients and 10 control subjects were examined for tissue-plasminogen activator activity, tissue-plasminogen activator antigen, fast tissue-plasminogen activator inhibitor and other fibrinolytic and haemostatic parameters including antigenic and functional protein C. Both patient and control groups were similar in age and smoking habits. All of these patients had a myocardial infarction between 1-3 months before this study. Assays were evaluated before and after an exercise test. Prothrombin time, activated partial thromboplastin time, protein C, plasminogen, alpha 2-antiplasmin, fibrinogen/fibrin degradation products and contact-activated fibrinolysis were similar before and after exercise in both groups. Fibrinolytic activity assayed by the euglobulin lysis time and fibrin-plate lysis methods was decreased in the patient group as compared with the control group but the difference was not significant. In basal conditions, tissue-plasminogen activator activity was defective in 50% of the coronary heart disease patients (p less than 0.01) and after exercise this percentage rose to 77% (p less than 0.01). However, tissue-plasminogen activator antigen in the coronary heart disease group was similar to that of the control group, both before and after exercise. The activity of the tissue-plasminogen activator inhibitor was persistently increased in coronary heart disease though this increase was not statistically significant. It is concluded that in coronary heart disease patients there is a defective fibrinolytic activity probably due to an increase in tissue-plasminogen activator inhibitor.

Adult

"Ex vivo" influence of fatty acids from plasma cholesterol and triglycerides on the fatty acid pattern of platelets.

We have studied "ex vivo", in 92 normal subjects, the influence of fatty acids (FA) that esterify plasma cholesterol and triglycerides on the fatty acid composition of phospholipids, triglycerides and free fatty acid fractions in platelets. High and significant correlations (p less than 0.001) were found for some of the platelet phospholipid FA and the same FA that esterify plasma cholesterol [18:1 (r = 0.56); 18:2 (r = 0.71) and 20:5 (r = 0.42)] and plasma triglycerides [18:1 (r = 0.57) and 18:2 (r = 0.66)]. Some significant correlations were also found between some of the platelet triglyceride FA and the same FA that esterify plasma phospholipids [18:1 (r = 0.58)], triglycerides [18:1 (r = 0.51), 18:2 (r = 0.52)] cholesterol [18:1 (r = 0.44)] and plasma free fatty acids [18:1 (r = 0.39); 18:2 (r = 0.40)]. By evaluating these results in conjunction with those of an earlier study, it can be concluded that "in vivo" the FA from different plasma lipid fractions and especially those esterifying the plasma cholesterol and phospholipid fractions, can influence the FA composition of platelet phospholipids in normal subjects. In trying to interpret the role played by plasma lipids in platelet lipids, it may be of interest to take into account the interrelationships found in this study.

Adult

Prostacyclin production by rat aorta "in vitro" is increased by the combined action of dipyridamole plus pentoxifylline.

The present study evaluates the effect of dipyridamole and pentoxifylline, individually and in combination, on PGI2-like production and arachidonic acid metabolism of rat aorta "in vitro". Pentoxifylline 100 microM and dipyridamole 92 and 184 microM increased PGI2-like activity, as measured by the platelet aggregation inhibitory capacity of the aortic ring incubates, by 71%, 46% and 60% respectively; a greater increase in PGI2-like activity was observed with the combination of the drugs than when they were used separately. This effect was observed even at the lowest doses assayed. In fact, dipyridamole 9.2 microM plus pentoxifylline 1 microM increased the PGI2-like activity by 30% while the individual increase was 4.5% and 10.6% respectively. To obtain more information on the effect of the dipyridamole-pentoxifylline combination on arachidonic acid metabolism, arteries were incubated with (1-14C) arachidonic acid, and the 6-keto-PGF1 alpha and PGE2 quantified. Dipyridamole 92 microM plus pentoxifylline 1 and 10 microM increased 6-keto-PGF1 alpha and PGE2 production by about 30% and 48% respectively while the combination with pentoxifylline 100 microM increased the 6-keto-PGF1 alpha 76.5% and the PGE2 50%. The possible biological effect and therapeutic implications of increased PGI2 production by the arteries due to the dipyridamole-pentoxifylline combination remains to be ascertained.

Animals

Activities of new quinoline derivatives against genital pathogens.

The in vitro activities of four quinoline carboxylic acids against 48 strains of Neisseria gonorrhoeae, 10 of Chlamydia trachomatis, and 32 of Ureaplasma urealyticum were compared. Ciprofloxacin was the most active against N. gonorrhoeae and C. trachomatis but had poor bactericidal activity against U. urealyticum, whereas ofloxacin showed the most bactericidal activity against U. urealyticum but was less active than ciprofloxacin against the two former pathogens. Norfloxacin and enoxacin were less active against all the studied pathogens.

Anti-Bacterial Agents

Possible homozygous factor VIIR disorder associated with fibrinolytic hyperactivity.

A family with inherited factor VII deficiency is described. The propositus is a 9-year-old girl with chronic haemorrhagic history of epistaxis and bleeding after tooth extractions. Her factor VII coagulant activity was less than 3% using rabbit thromboplastin. She had a factor VII antigen level of 50%. Both parents were heterozygous for factor VII deficiency. The father had procoagulant factor VII (VII-C) of 44% and factor VII antigen (VII-Ag) of 74%, and the mother had 54% of factor VII-C and 85% of VII-Ag. Her only brother had normal levels of factor VII-C (100%). Additionally, some abnormalities in the fibrinolytic system were detected both in the propositus and her brother with shortened euglobulin lysis times and increased functional levels of plasminogen activator. To our knowledge, the clinical association of inherited factor VII deficiency and familial fibrinolytic disturbances has not been described so far.

Blood Coagulation Tests

Soluble fibrin monomer complexes and other hemostatic parameters in patients with intrauterine fetal death.

Hemostatic parameters, especially soluble fibrin monomer complexes, have been studied in 114 patients with intrauterine fetal death. The patients were classified into three groups according to the duration of fetal retention. A correlation was observed between a longer duration of fetal retention and the hemostatic alteration. Moreover, in the groups of patients in which this hemostatic disorder was more evident, an improvement in these alterations was detected after fetal evacuation. A hemorrhagic picture with consumption of coagulation factors and cross-linked fibrin oligomers was detected after uterine evacuation in only 1 case and required an emergency hysterectomy and the administration of blood and plasma. In the rest of the patients, fetal evacuation was sufficient to normalize the parameters and no hemorrhagic complications were observed. The favorable evolution and minimal hemostatic alterations in the majority of the patients with intrauterine fetal death, when early obstetric management was established, are discussed.

Adult

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