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Biomedical subjects

J Aznar

Publications and source records attributed to J Aznar.

At least 163 records · Page 9Linked to original sources
PubMed1989

[Determination of free erythrocyte protoporphyrin in thalassemic trait].

Free erythrocyte protoporphirin (FEP), along with diverse haematologic and iron metabolism data, were determined in 60 carriers of the thalassaemic trait (29 beta and 31 delta beta). FEP rates were significantly higher in thalassaemia carriers (39.04 +/- 14.12 micrograms/dl) than in a control group (24.95 +/- 4.70 micrograms/dl) (p less than 0.05). No correlation between FEP and any other iron metabolism parameter, or the severity of anaemia, was found. No FEP differences appeared between the beta (41.06 +/- 16.5 micrograms/dl) and delta beta (37.1 +/- 11.06 micrograms/dl) traits, so, although FEP rates are increased in thalassaemia carriers, they are useless in differentiating between the commonest thalassaemic forms in our country.

Adolescent↗
PubMed1989

[Evaluation of erythrocyte deformability in carriers of thalassemic trait with the Hanss' hemorheometer].

Red-cell deformability was assessed with the Hanss' haemorheometer in 63 carriers of the thalassaemic trait (20 beta and 43 delta beta). Impaired deformability (rigidity index 10.5 +/- 1.4) was present in 80% of the carriers of both beta- and delta beta-traits, as compared with a control group (rigidity index 8.7 +/- 0.6). No correlation was found between such indices and several parameters capable of influencing upon red-cell deformability, namely, MCV, MCH, RDW and MDA. The possibility of any impairment of lipid compounds in red cell membrane is suggested as a cause of decreased deformability in thalassaemia carriers.

Adolescent↗
PubMed1988

Antiplatelet activity of dipyridamole in non anticoagulated whole blood.

Dipyridamole has been reported to inhibit platelet aggregation in citrate anticoagulated whole blood (WB). However, citrate may alter the response of platelets and/or the effect of antiplatelet drugs. The present study evaluates the "ex vivo" effect of dipyridamole, two hours after a single dose (3 mg/Kg) in 25 normal subjects in non-anticoagulated (native) WB and in WB anticoagulated with citrate or hirudin. We have used the BASIC anticoagulated with citrate or hirudin. We have used the BASIC wave as analytical method, which can evaluate the early steps of platelet activation with collagen in less than 1 min after venoclysis, thus allowing the study in native WB. The results show that dipyridamole significantly inhibits (p less than 0.001) platelet activation to collagen in citrated WB (66%) while the drug's effect is much lower (21%) and non-significant if evaluated in native or hirudine anticoagulated WB. These results suggest that citrate or low calcium concentration amplify the drug's platelet inhibitory action in WB and, therefore, the laboratory results may overestimate the drug's effect "in vivo".

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↗
PubMed1988

Composition of platelet fatty acids and their modulation by plasma fatty acids in humans: effect of age and sex.

This study evaluates the influence of sex on platelet fatty acid (FA) composition, and whether sex differences are conditioned by age. Since plasma FA have a specific relationship with platelet FA their variations with age and sex are also considered. Forty-nine male-female human couples (16-75 years), where within each couple the partners were on qualitatively similar diets and of similar age, were studied. Few differences were found between the whole groups of men and women in platelet FA. A comparison of data on FA in platelet phospholipids (PL) from 3 age groups (16-40, 40-60 and over 60) showed an increase in saturated FA of middle-aged subjects, an age-dependent decrease in 20: 5 in both sexes and of 18: 2 mainly in women. The percentage of plasma phosphatidylserine plus phosphatidylinositol decreased in middle-aged subjects. With regard to the influence of FA of plasma PL on FA of platelet PL, we found a higher correlation coefficient (r) for 16:0 and 18:0 and 20:4 and a lower one for 20:5 in middle-aged men and post-menopausal women. Considering that an increase in saturated FA and 20:4 and a decrease in 20:5 in platelet PL may increase platelet function, the plasma FA influence on platelets may help to explain the higher incidence of CHD in those groups of subjects.

Adolescent↗
PubMed1988

Plasminogen activator inhibitor activity and other fibrinolytic variables in patients with coronary artery disease.

Several fibrinolytic variables, including plasminogen activator inhibitor activity, were studied before and after exercise in 67 normolipidaemic patients with coronary artery disease and in 25 hyperlipidaemic patients with coronary artery disease. Before exercise plasminogen activator inhibitor activity was higher in the patient groups than in a group of 10 healthy volunteers. For those who were normolipidaemic plasminogen activator inhibitor activity was greater in patients with angina pectoris who had had a myocardial infarction. The concentration of antigenic tissue-type plasminogen activator was similar in all the patients with coronary artery disease and higher than in the control group. After the exercise test fibrinolytic capacity was lower in the patients with angina pectoris and a previous history of myocardial infarction. After exercise both the released immunological tissue-type plasminogen activator and fibrinolytic capacity were lower in the hyperlipidaemic patients than in the normolipidaemic patients. The concentration of plasminogen activator inhibitor was also higher in the hyperlipidaemic patients. Patients with hyperlipidaemia IV had the highest plasminogen activator inhibitor activity. The increase in plasminogen activator inhibitor activity found in the patients was partially inhibited by antiserum against plasminogen activator inhibitor-1 in vitro. The formation of a complex of about 115,000 daltons between plasminogen activator inhibitor and purified tissue-type plasminogen activator was detected by a zymographic fibrin technique. These findings show that in patients with coronary artery disease fibrinolytic activity is impaired by an increase in plasminogen activator inhibitor. Impaired fibrinolysis may be related to the clinical evolution of coronary artery disease in these patients.

Adult↗
PubMed1987

Effect of postprandial lipaemia on platelet function in man evaluated in whole blood.

The effect of a fatty meal (100 g of fat) on platelet function is evaluated. Two hours after the fat intake (dairy cream) there is a significant reduction in the initial stages of platelet activation by collagen (1 and 0.5 micrograms/ml) as measured by a new analytical method, the BASIC wave, and by the decrease in the beta-Thromboglobulin released by stimulated platelets. This effect is greater in platelet rich plasma (PRP) than in whole blood. Red blood cells (RBC) have a potentiating effect on platelet activation by collagen both before and after the fat intake which is indicated by an increase in the BASIC wave intensity. No significant differences were found, however, in platelet aggregation in PRP or whole blood evaluated by impedance aggregometry. These results suggest that the increase of chylomicrons after fat intake has an inhibitory effect on platelet activation but does not modify platelet aggregation. In addition, it seems that lipaemia does not modify RBC interactions with platelets in collagen stimulated samples.

Animals↗
PubMed1987

Study of the formation of fibrin clot in cirrhotic patients. An approach to study of acquired dysfibrinogenemia.

Alterations in the coagulation system are common in patients with liver disease. We have examined the importance of the species and chains of fibrinogen in 3 groups of cirrhotic patients. The study of the gelation of fibrinogen in cirrhotic patients shows that the lag time increases in 80.3% of them and that the maximum gelation rate is altered in 51% of these plasmas. Also it is observed that 80% of the plasmas from cirrhotic patients have a percentage (23.3 +/- 7.7%) of unpolymerized alpha chain, after highly cross-linked fibrin formation. These alterations, in lag time and in the maximum gelation rate, have no significant correlation with the situation of the fibrinolytic system in these patients. The study of isolated fibrinogen from cirrhotic patients and normal subjects plasma, shows that there are no objective alterations in the percentage of fibrinogen species, the amount of sialic acid or the ratio of polypeptide chains.

Afibrinogenemia↗
PubMed1987

Fibrinogen Barcelona I. Congenital dysfibrinogenemia characterized by defective release of fibrinopeptide A and fibrinogen degradation products.

A congenital dysfibrinogenemia, fibrinogen Barcelona I, was detected in a 28 year-old woman with no prior history of bleeding. The thrombin induced clotting of plasma and purified fibrinogen was much prolonged. Fibrin monomer aggregation was impaired. The abnormal fibrinogen polymerized in the presence of calcium and can be further cross-linked by factor XIIIa. The turbidity of fibrin gels obtained from fibrinogen Barcelona was much lower than normal fibrinogen. The kinetic constant Km for fibrinogen Barcelona plus normal fibrinogen gelation was similar to normal fibrinogen gelation. The release rate of fibrinopeptide A by thrombin was slower than that of normal fibrinogen. However, two mol of fibrinopeptide A was released per mol of fibrinogen in 30 min. SDS-PAGE of abnormal and normal fibrinogens and of reduced fibrinogens showed identical patterns. Sialic acid content was markedly decreased in fibrinogen Barcelona. Plasmin digestion of two fibrinogens showed identical patterns in SDS-PAGE as regards X fragment formation. The kinetics of fibrinogen degradation showed a decrease in the formation rate of D and E fragments. The fact that the patient was in threat of abortion and developing a haemorrhagic syndrome may indicate that the defect in the fibrinogen was important in the pathogenesis of haemorrhage in this patient.

Adult↗
PubMed1987

Congenital hypofibrinogenemia and pregnancy, obstetric and hematological management.

A 27-year-old pregnant woman with severe congenital hypofibrinogenemia was studied from the 18th to the 40th week of pregnancy, after which she had a normal delivery. The results of the quantitative and qualitative fibrinogen studies done on the patient made it possible to rule out associated dysfibrinogenemia. No variations in the concentration and function of fibrinogen were observed during gestation. The only treatment given was a transfusion of fresh plasma prior to delivery. The importance of fibrinogen in maintaining normal placental insertion and the obstetric management of predelivery and delivery are discussed.

Adult↗
PubMed1987

Single doses of ofloxacin in uncomplicated gonorrhoea.

The clinical efficacies of 2 different single-dose oral treatments of ofloxacin were evaluated in a double-blind, randomised study of 60 males with gonococcal urethritis. 30 patients received a single dose of ofloxacin 100mg and 30 received a single dose of ofloxacin 200mg. The minimal inhibitory concentrations of ofloxacin against all isolates were less than or equal to 0.25 mg/L. Neisseria gonorrhoeae was eradicated from all 50 patients evaluated and clinical cure was achieved in 84%. In total, 8 patients developed post-gonococcal urethritis, although there was a significantly (p less than 0.05) lower rate of post-gonococcal urethritis in the group treated with ofloxacin 200mg. In conclusion, a single oral dose of ofloxacin 100mg could be an alternative treatment for uncomplicated gonorrhoea.

Adolescent↗