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Biomedical subjects

V Vicente

Publications and source records attributed to V Vicente.

At least 91 records · Page 5Linked to original sources
PubMed1994

Influence of somatostatin in the evolution of acute pancreatitis. A prospective randomized study.

A prospective, controlled, and randomized clinical study was carried out with the purpose of evaluating the influence of somatostatin in the evolution of acute pancreatitis. One hundred patients were randomly divided into two groups, a control group (n = 50 patients) and a somatostatin group (n = 50 patients to whom a dosage of 250 micrograms/h was administered for 48 h following a bolus of 250 micrograms at the beginning of therapy). The two groups were homogeneous in age, sex, etiology, and severity of clinical picture (on admission). The following parameters were compared in the two groups: 1. Evolution of the Computerized Axial Tomography (CT) findings on admission and after 48 h; 2. Length of hospital stay; 3. Need for surgery; and 4. Mortality. The results from the CT scans showed a significant statistical difference in favor of somatostatin regarding the evolution of pancreatic lesions and length of stay in the hospital. Another study using a larger sample would be required in order to evaluate the rest of the parameters.

Acute Disease↗
PubMed1994

Stability of glycoproteins Ib/IX and IIb/IIIa during preparation and storage of platelet concentrates: detection by binding assays with epitope-defined monoclonal antibodies and physiological ligands.

Preservation of the glycoprotein (GP) complexes Ib/IX and IIb/IIIa, because of their role as specific platelet receptors for adhesive proteins, is essential for the haemostatic efficacy of transfusions of platelet concentrates (PCs). We have combined binding assays with epitope-defined monoclonal antibodies, and with the physiological ligands von Willebrand factor and fibrinogen (Fo), to investigate the total expression and functional status of these receptors, in PCs stored for up to 9 days. Routine preparation and storage for up to 5 days have no apparent effect on the surface expression and the functional status of GPs Ib/IX and IIb/IIIa. However, after prolonged storage for up to 9 days we found a 50% decrease in the level of the total and functional GP Ib/IX content of platelets. This finding parallelled a significant rise in plasma glycocalicin, a proteolytic fragment of GP Ib. In addition, long-term storage promoted an impairment in the exposure of GP IIb/IIIa to Fo, and a 50% decrease in Fo binding capacity, without affecting the complex quantitatively. Finally, we also noticed a storage-induced increase in the platelet surface expression of GMP 140, and after 9 days of storage there was a rise in mean platelet volume, and a significant reduction in pH levels.

Agglutination Tests↗
PubMed1994

[Comparative multicenter study of a rabbit high-sensitivity thromboplastin and a recombinant thromboplastin with synthetic phospholipids].

PURPOSE: The purpose of the present study was to compare the results obtained with a human recombinant thromboplastin (Innovin, Baxter) (IN) and a high-sensitivity rabbit brain reagent (Thromboplastin IS, Baxter) (IS), on the performance of prothrombin time (PT) test and the functional assay of factors included in the extrinsic coagulation system, in order to establish possible differences on imprecision, diagnostic accuracy and sensitivity to the oral anticoagulant defect, between the two products. MATERIAL AND METHODS: Six Spanish hospital took part in the study. Plasma samples from 221 healthy subjects, 100 patients with severe liver disease, 27 with dysfibrinogenaemia, 10 with lupus anticoagulant and from 13 individuals propositus and their relatives with congenital deficiencies of the extrinsic coagulation pathway, and their relatives were studied; 188 patients stabilized on oral anticoagulant therapy and 82 on heparin therapy were also included. The in vitro effect of heparin was tested by addition of increasing amounts of heparin (0.3 to 10.0 IU/mL) to aliquots of normal plasma. RESULTS: Both in the intra-assay and in the inter-assay imprecision study, a better coefficient of variation was obtained with IN when the PT was performed on abnormal samples. Prothrombin time ratio from patients with liver disease had significantly higher values with IS. On the contrary, IN had a higher sensitivity in samples from patients with dysfibrinogenaemia or from those stabilized on oral anticoagulant therapy. In showed a very low sensitivity to heparin at concentrations corresponding to the therapeutic range. CONCLUSIONS: The results of this field study indicate that IN, compared with a high-sensitivity rabbit brain thromboplastin, is a suitable reagent for PT determination in normal subjects, patients with liver disease or with congenital deficiencies of clotting factors. It shows a higher sensitivity in cases of dysfibrinogenaemia and in patients on oral anticoagulant therapy. In addition, the recombinant reagent had better reproducibility when the PT was performed on abnormal samples, and it was hardly affected by heparin within the therapeutic range.

Afibrinogenemia↗
PubMed1993

Repeated infusions of DDAVP induce low response of FVIII and vWF but not of plasminogen activators.

Although the vasopressin analogue desamino-d-arginine vasopressin (DDAVP) induces a very well characterized increase in factor VIII (FVIII), von Willebrand factor (vWF), tissue plasminogen activator (t-PA) and urokinase-type plasminogen activator (u-PA), the mechanism(s) by which DDAVP enhances the plasma levels of these proteins is poorly understood. Some clinical evidence suggests that certain patients repeatedly treated with DDAVP at closely spaced intervals become progressively unresponsive (tachyphylaxis). In order to investigate the effect of repeated DDAVP infusion on the behaviour of FVIII, vWF, t-PA and u-PA, we infused three different doses of DDAVP (0.3 microgram/Kg) to six healthy volunteers (19-26 years old, mean 22) at 12-hour intervals. Blood samples were collected immediately before and after DDAVP. The second and third infusion of DDAVP induced a low response of FVIII and vWF. In contrast, t-PA and u-PA exhibited a consistent response after each DDAVP infusion. If the progressive decrease of FVIII and vFW response observed in healthy subjects after repeated doses of DDAVP at 12-hour intervals is extended to haemophiliacs and von Willebrand's patients, the usefulness of desmopressin may be limited when these proteins must be raised therapeutically for a prolonged period of time. Finally, our results suggest that the mechanism for regulating the release of vWF and plasminogen activators in the conditions of our study are not dependent.

Adult↗
PubMed1993

[Primary antiphospholipid syndrome in juvenile ischemic stroke].

Results obtained in three patients with juvenile ischemic stroke and criteria of primary antiphospholipid syndrome is reported. These patients are selected out from a series of 12 patients with 18-mounts follow-up. Lupic anticoagulant and anticardiolipin antibodies were found in two of three patients and one patient show anticardiolipin antibodies with negative lupic anticoagulant. All others coagulation proteins examined (antithrombin III, plasminogen, protein C and protein S) were normal. We conclude that antiphospholipid antibodies are associated with increase risk of thrombosis. Therefore should be systematically investigated in juvenile ischemic stroke of unknown aetiology.

Adult↗
PubMed1992

Activated protein C: alpha 1-antitrypsin (APC: alpha 1 AT) complex as a marker for in vitro diagnosis of prethrombotic states.

The purpose of the study was to test whether APC: alpha 1AT complex is a useful clinical marker of the activation of coagulation. The rationale for this is that activated protein C may appear in circulation at an early stage of blood coagulation, when subcoagulant amounts of thrombin are formed. Given the relatively higher half-life of APC: alpha 1AT as compared to that of thrombin:AT-III (TAT) complexes, we hypothesized that APC:alpha 1AT could represent an amplification of the thrombin generated in the first events of coagulation. Using sandwich ELISA's we measured APC: alpha 1AT and TAT complexes as well as complexes of AT-III with its target proteases in normal subjects and in several clinical groups of patients prone to thrombotic episodes, including pregnancy, preeclampsia, hemodialysis, gynecological tumors, diabetes and oral contraceptives. APC: alpha 1AT complex was significantly increased in all clinical groups as compared to normal subjects and showed relatively higher increases than did TAT and ATM complexes in the majority of the groups studied. There was a significant and positive correlation between APC: alpha 1AT and TAT complex levels in the majority of the groups, as well as between TAT and ATM and between APC: alpha 1AT and ATM complex levels. We conclude that APC: alpha 1AT complex can be used as a sensitive marker of prethrombotic states.

Antithrombin III↗
PubMed1992

[The attitudes of primary care professionals on mental patients and psychiatric care].

AIM: To describe the views of different primary care professionals regarding mental illness, psychiatric patients and mental health care. DESIGN: Crossover survey. SITE. Primary care centres in a health zone. PARTICIPANTS: All the primary care centre professionals and social service base teams. Out of 66 possible subjects, 61 answered the questionnaire. MEASUREMENTS AND RESULTS: A questionnaire composed by ourselves about peoples' opinions was given. The chi 2 test was then used to analyse the questionnaire, both item by item and by means of the distribution of frequencies and comparisons. On some items differences between Health Professionals and social service staff occurred. But there were no differences between doctors and nursing staff, nor between men and women (level of importance: 0.50). For 91% of those surveyed, mental health is an illness like any other. 87% believe psychiatry is a science; and 77% that psychiatry is related to the rest of medicine. 48% believe that the majority of mental disturbances are untreatable. 80% affirm that psychiatric admissions should be into special hospitals. CONCLUSION: The authors highlight the need to overcome the discrepancy between positive attitudes on the theoretical side and a reluctance to integrate those attitudes into practice.

Adult↗
PubMed1992

Microscopic rice bodies in rheumatoid synovial fluid sediments.

To determine the clinical significance of the microscopic study of the synovial fluid (SF) sediment, 306 sediments were examined from 216 patients with the most frequently occurring acute and chronic arthropathies. The SF was obtained using a fine gauge needle. Microscopic rice bodies were seen in 53 (17.3%) of the samples studied. Forty-five (84.9%) of the samples in which rice bodies were observed were from patients with rheumatoid arthritis (RA) (p < 0.001); 34.9% of the 129 RA samples were found to contain rice bodies. The specificity of finding rice bodies in RA was 95.5%. Most rice bodies were composed of partly or totally hyalinized fibrinous material; in their interior, mononuclear cells were predominantly observed--most of them macrophagic in appearance. With less frequency the rice bodies exhibited central areas of fibrosis. Our results suggest that microscopic rice bodies are fibrinous particles derived from the entrapping of cells in the dense fibrin network present in inflammatory SF.

Arthritis, Rheumatoid↗