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L Preda

Publications and source records attributed to L Preda.

At least 37 records · Page 2Linked to original sources
PubMed1996

A new global test for the evaluation of the protein C-protein S system.

We have developed a simple screening assay for evaluating the global activity of the protein C/protein S system. The new test consists of measuring the prothrombin time (PT) with bovine thromboplastin before and after activation of the PC present in the plasma sample by PROTAC, derived from Agkistrodon contortrix snake contortrix venom. Prolongation of the PT was directly related to the activity of the PC/PS system. One hundred and nineteen thrombophilic patients including 36 with PC deficiency, 22 with PS defect, 35 with APC resistance and 26 with other genetic defects predisposing to thrombosis were tested with the new assay together with 112 healthy subjects. The new test showed a high sensitivity for detection of inherited defects related to the PC/PS system (92%, 91% and 97% for PC defects, PS defects and APC resistance, respectively). Since it can be performed automatically the test could be used to screen for patients predisposed to thrombosis due to impairment of the PC/PS system and those patients who might eventually require more extensive evaluation of the PC/PS system by single component assays.

Adult↗
PubMed1995

[Spiral computerized tomography with tridimensional reconstruction (spiral 3D CT) in the study of maxillofacial pathology].

Three dimensional computer reconstruction of CT scans provide head and neck surgeons with an exciting interactive display of clinical anatomy. The 3D CT reconstruction of complex maxillo facial anatomic parts permits a more specific preoperative analysis and surgical planning. Its delineation of disease extension aids the surgeon in developing his own mental three-dimensional image of the regional morphology. Three-dimensional CT permits a clearer perception of the extent of fracture comminution and resulting displacement of fragments. In the case of maxillo-facial tumors, 3D images provide a very clear picture of the extent of erosion involving the adjacent critical organs. Three-dimensional imaging in first generation 3D scanners did have some limitations such as long reconstruction times and inadequate resolution. Subsequent generations, in particular the spiral 3D CT, have eliminated these drawbacks. Furthermore, costs are comparable with those of other computer reconstruction technology that might provide similar images. Representative cases demonstrating the use of 3D CT in maxillofacial surgery and its benefits in planning surgery are discussed.

Adenocarcinoma↗
PubMed1994

[Interventional modalities in immunosuppressed patients].

In immunocompromised patients interventional modalities have diagnostic and/or therapeutic purposes--in both cases they are justified on the basis of the frequently aspecific clinical and instrumental findings and because of the clinical need to carry out the most specific treatment as soon as possible. The authors stress the particular weakness of immunocompromised patients to invasive approaches and discuss the indications, contraindications and precautions which must be taken when performing interventional radiologic modalities. Diagnostic imaging uses radioscopy, US and CT for guidance, each of them allowing a rapid percutaneous confirmation of lesion nature, the assessment of infection in a collection, of a neoplastic lesion type, or of the microbiology of an infectious lesion. Interventional modalities are frequently indicated in chest diseases--e.g., for punctures and percutaneous drainage of empyematous pleural collections or of pulmonary abscesses, percutaneous needle biopsies of lung lesions, or endoscopic dilatation of tracheobronchial stenoses. The percutaneous drainage of lung abscesses in immunocompromised patients makes recovery easier. The diagnostic accuracy of the results of needle biopsy is lower in lung infections than in neoplastic lesions. Indications to abdominal interventional procedures are less frequent--i.e., percutaneous drainage of rare abscesses, percutaneous needle biopsy of nodal mesenteric or lumboaortic masses. Some clinical conditions are diagnosed only with invasive radiologic procedures--e.g., ERCP diagnoses sclerosing cholangitis in AIDS. CT is the basic and the best modality to guide percutaneous drainage in both the abdomen and the chest, to assess contraindications or to indicate some specific modes; in some cases even plurifocal abscesses can be treated with a percutaneous imaging approach.

Abdomen↗
PubMed1993

Effects of acute doses of oxiracetam in the scopolamine model of human amnesia.

The scopolamine model of amnesia has been used to test the pharmacodynamic efficacy of oxiracetam in 12 healthy volunteers. The subjects were divided into four experimental groups, according to a double-blind cross over incomplete randomized block design. After a baseline neuropsychological examination, each subject received in two separate sessions one of the following treatments, as acute oral doses: oxiracetam 800, 1600, 2400 mg or placebo. One hour after treatment scopolamine hydrobromide (0.5 mg) was given subcutaneously. The cognitive performance was tested before and 1, 2, 3 and 25 h after scopolamine administration. Scopolamine caused a deterioration of performance of verbal episodic memory, semantic memory and attention tests. In comparison to placebo, oxiracetam improved the overall test performance, with a statistically significant difference at the dose of 1600 mg on delayed recall of word lists, and showed dose-related antagonism of scopolamine-induced effects also on semantic memory and attention. The efficacy of an acute dose of oxiracetam in reducing scopolamine-induced cognitive impairment supports the potential usefulness of this pharmacological model of amnesia for studying the effects of cognition enhancers in humans.

Adult↗
PubMed1992

Protein C and protein S levels in uremic patients before and after dialysis.

The inhibitory capacity of the natural protein C (PC)/protein S (PS) system was evaluated measuring both the functional activity and the antigen level of both these inhibitors in 30 uremic patients before and after a dialytic treatment and in 30 healthy normal volunteers. PC functional activity was determined by two methods, one clotting and one chromogenic. PS antigen level was measured both as free protein and as total content. Unlike previous authors, we found that PC functional activity and the antigen level were normal in patients before dialysis, with a significant increase after. PS functional activity and free and total antigen levels were all normal before dialysis, and all except free antigen showed a significant post-treatment rise.

Blood Coagulation Tests↗
PubMed1992

Functional protein S in women with lupus anticoagulant inhibitor.

Protein C (PC) and protein S (PS) are components of a potent, natural anticoagulant system. A deficiency of one of these two inhibitors is associated with thrombotic events in young people. A significant reduction in functional PS activity has been observed during normal pregnancy, and recurrent fetal loss may occur in women with lupus anticoagulant (LA) inhibitor. We measured functional PS activity and free PS antigen in 16 non pregnant patients with LA inhibitor and in 17 normal women as controls. A significant difference was observed between patients and controls in functional PS activity (65 +/- 23% vs 87 +/- 15%, p = 0.02) but not in free PS antigen (88 +/- 17% vs 93 +/- 17%). Functional PS activity decreased only in six patients (37%). Removal of IgG from plasma reduced the difference in functional PS activity between patients and controls. Immunologic IgG levels did not correlate with anti-phospholipid antibodies (APA) activities, activated partial thromboplastin time/kaolin clotting time (aPTT/KCT) data or functional PS activity.

Abortion, Habitual↗
PubMed1991

Protein S activity in patients with heredofamilial protein S deficiency and in patients with juvenile venous thrombosis. Results of a functional method.

Using an ACL 300R coagulometer (Instrumentation Laboratory) we assessed the clinical usefulness of a new method to measure PS activity (PS:Act), based on the prolongation of prothrombin time of a mixture of diluted plasma sample, PS depleted plasma previously incubated with Protac for protein C activation, bovine thromboplastin and calcium ions. The results were compared with those from immunological assays. PS:Act was measured in 42 apparently healthy subjects, in 12 patients with hereditary PS deficiency (HPSD group) diagnosed on the basis of immunologic tests and in 48 patients with episodes of juvenile venous thromboembolism at least three months prior to testing (JVTE group). All the HPSD patients had PS:Act below the normal range (less than 62%). In JVTE group 9 patients (18.7%) showed abnormal results for PS:Act, 4 (8.3%) had low levels of free PS:Ag; all patients had normal total PS:Ag levels. Levels of antiphospholipid antibodies (immunologic test) were normal in the 9 JVTE patients with low PS:Act. When all the results were considered together (n = 102), the correlation coefficient between PS:Act and free PS:Ag was 0.78 (p less than 0.01).

Adolescent↗
PubMed1990

A prothrombin time-based functional assay of protein S.

Protein S activity was measured as the degree of prolongation of a prothrombin time-based clotting assay in which diluted test sample, protein S-depleted plasma previously incubated with Protac to fully activate protein C, bovine thromboplastin and calcium ions are mixed. Assay specificity was first demonstrated by observing that the prolongation of the clotting time was dependent on protein S and was subsequently confirmed by testing plasma samples from patients with conditions known to affect protein S activity. High sensitivity, reproducibility (interassay coefficient of variation lower than 5%) and easy handling of samples and reagents make this assay suitable for screening of congenital and acquired protein S deficiency.

Anticoagulants↗
PubMed1990

Aortopulmonary window coexisting with tetralogy of Fallot: echocardiographic diagnosis.

Aortopulmonary window coexisting with tetralogy of Fallot (TF) was prospectively diagnosed by two-dimensional (2D) echocardiography and Doppler in an 18-month-old boy; the diagnosis was confirmed by cardiac catheterization and angiocardiography. Surgical correction was performed, but the patient died in the operating room from right ventricular dysfunction. The autopsy showed an adequate surgical repair, but the histologic examination of the lungs demonstrated severe pulmonary vascular disease, which was presumed to be the cause of death.

Aortopulmonary Septal Defect↗
PubMed1990

[Total anomalous pulmonary venous drainage: is a surgical correction possible on the sole basis of echocardiography?].

Between April '83 and August '89, 33 patients with total anomalous pulmonary venous drainage were studied at the department of Cardiology in Bergamo. There were 18 males and 15 females, aged between three days and 8 months (average: two months). In this study only cases of isolated total anomalous pulmonary venous drainage were taken into consideration. The patients underwent echocardiographic examination with ATL MK 600, Vingmed 700, ATL Ultramark 9 with 3.5; 5; 7.5; MHz transducers; in the last three years the echocardiographic examination was integrated by continuous and pulsed wave Doppler and, in the last year, by color Doppler. The morphologic diagnosis was routinely established by means of the sequential approach method. A common feature in all types of total anomalous pulmonary venous drainage was the impossibility of defining the connections of the pulmonary veins with the left atrium. Furthermore, patients had a volume overload of the right heart, and atrial septal defects of various sizes. The site of anomalous drainage of the pulmonary veins was assessed by means of multiple cuts from subcostal, precordial and suprasternal windows. The echocardiographic diagnosis was exact and complete in 29 cases (87.9%), and in four cases it was incomplete but basically correct (12.1%). The anatomical findings were confirmed during cardiac surgery in 32 cases and by autopsy in one case of supracardiac total anomalous pulmonary venous drainage in a critically ill patient, who died before surgery. Of the 32 patients who underwent surgical correction, 20 (62.5%) had only an echocardiographic diagnosis, which resulted correct in all cases. The majority of patients with isolated TAPVD can be confidently diagnosed by means of echocardiography, thus, avoiding preoperative catheterization.

Echocardiography↗
PubMed1989

[A case of lipoma of the small intestine].

A case of small bowel lipoma with few evident symptoms is reported. Radiological diagnosis was confirmed at surgery. The comparative rarity of this type of benign intestinal neoformation is pointed out.

Humans↗
PubMed1989

[Cerebral ischemic malacia. A retrospective study of CAT scan-documented cases].

One hundred male patients affected by ischaemic stroke were studied with the use of CT scans. A clinical-biohumoral pattern was traced for every patient, with particular regard to the incidence of risk factors for stroke of which systolic arterial hypertension, appear to be the most frequent. It would be useful to extend this research to female patients as well in order to discover any significant differences between sexes.

Age Factors↗
PubMed1988

Method for the determination of functional (clottable) fibrinogen by the new family of ACL coagulometers.

A new family of coagulometers ACL 100, 200 and 300 (Instrumentation Laboratory, IL) has recently been introduced, in addition to the existing ACL 810. This paper presents a technique to determine clottable fibrinogen using the ACL method based on the measurement of the light scattered from the reaction mixture during a PT test. This technique was found to compare well with the present most commonly used methods.

Afibrinogenemia↗