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Biomedical subjects

P Geslin

Publications and source records attributed to P Geslin.

162 records · Page 9Linked to original sources
PubMedDate not supplied

Experimental validation of an automated edge-detection method for a simultaneous determination of the endocardial and epicardial borders in short-axis cardiac MR images: application in normal volunteers.

The goal of this study was to put together several techniques of image segmentation to provide a reliable assessment of the left ventricular mass with short-axis cardiac MR images. No initial manual input was required for this process based on region growing, gradient detection, and adaptive thresholding. A comparison between actual mass and automatic assessment was implemented with 9 minipigs that underwent spin-echo MR imaging. Fifteen normal volunteers were studied with a fast-gradient-echo sequence. The automatic segmentation was then controlled by three trained observers. Actual mass and automatic segmentation were strongly correlated (r = .97 with P < .01). For normal volunteers, the standard error of estimation of the automatic assessment (12 g) compared well with the average myocardial mass (120 +/- 30 g) and the interobserver reproducibility of the manual assessment (9 g). These results allow the application of this method to the quantification of the left ventricular function and mass in clinical practice.

Adult↗
PubMedDate not supplied

Ribotyping of Streptococcus agalactiae strains isolated from vaginas of asymptomatic women.

One hundred and eleven strains of Streptococcus agalactiae isolated from vaginas of asymptomatic women were characterized by determination of restriction length polymorphism profiles of rDNA regions (rDNA RFLP patterns) and serotyping. Thirty-five different PstI rDNA RFLP patterns were identified. Half of the strains fell into only seven of these 35 groups. No correlation between serotypes and rDNA RFLP patterns was found. These results indicate that (i) the genetic diversity of the S. agalactiae species is relatively limited and (ii) determination of rDNA RFLP patterns can be used as a typing system only in conjunction with serotyping.

Bacterial Typing Techniques↗
PubMedDate not supplied

Simultaneous and correlated detection of endocardial and epicardial borders on short-axis MR images for the measurement of left ventricular mass.

A method was developed for fast, reproducible assessment of left ventricular mass with detection of the endocardial and epicardial borders. The method makes use of short-axis magnetic resonance (MR) imaging in conjunction with an integrated segmentation approach that includes region growing, edge detection, and adaptive thresholding. The mass of the left ventricle in nine Yucatan minipigs was measured ex vivo and compared with the mass as determined in vivo with both full automated segmentation and an interactive process involving two trained observers. The test sample consisted of 59 sections obtained during diastole. There was good correlation between actual mass and both automatically and manually assessed mass. Linear regression analysis showed that the difference between ex vivo measurement and automatic mass assessment (standard error of estimation [SEE] = 5 g) was similar to interobserver variability in interactive mass assessment (SEE = 4 g). Mass assessment with short-axis MR imaging and an integrated segmentation approach does not require location of the ventricular cavity and allows precise delineation of the endocardial and epicardial borders. The results of this experimental study are encouraging for the potential use of this technique in clinical cardiac functional analyses.

Algorithms↗
PubMedDate not supplied

[Severe anaphylactoid reactions after intravenous corticosteroids. Report of a case and review of the literature].

We report a case of fatal anaphylactic reaction to intravenous methylprednisolone succinate therapy developed in a 51 year old asthmatic man with aspirin intolerance and undetermined myocarditis. 14 similar cases were found in literature and analysed: asthma and aspirin intolerance seem to be risk factors; the organism reacts against either unconjugated corticoid or esterified corticoid principally its succinate salt; the mechanism of these reactions remains not clear; it may be either a true allergic reaction or a non specific reaction.

Anaphylaxis↗
PubMedDate not supplied

[Pneumococcal serotyping in France. Development (1978-1982) and vaccine covering].

From 09/1977 till 08/1982, 2,449 pneumococcus strains coming from Paris or province hospitals were typed according to the Danish system with antisera from the Copenhagen Statens Serum Institut by counter-immunoelectrophoresis for the first 900 and by capsular swelling afterwards. For the whole, the first 14 types or groups are in order: 19 (348), 6 (261), 23 (231), 3 (205), 1 (158), 14 (104), 9 (103), 18 (94), 7 (82), 11 (82), 15 (82), 4 (74), 8 (63), 10 (55), and make up 79.3% of the whole. For the 687 strains isolated from haemocultures or from cerebrospinal fluids, the first 14 types or groups are in order: 1 (95), 19 (69), 6 (56), 23 (49), 4 (47), 3 (44), 7 (42), 18 (40), 9 (35), 5 (32), 14 (30), 8 (27), 15 (18), 24 (13), and make up 86.9% of these strains. The annual variations for these 687 strains are slight as regards the 14 most frequent groups and types: the type I is always first, except for one year. The definition of serotypes in the groups for 261 strains isolated from cerebrospinal fluids or from haemocultures, in 1981 and 1982, allowed a study of the "vaccinal covering". It is 64.75% for the marketed tetradecavalent vaccine and 82.75% for a 23 valency vaccine defined according to international serotype statements.

Bacterial Vaccines↗
PubMedDate not supplied

[Kinetics of the local immune response in lobar pneumonia].

In 19 patients suffering from lobar pneumonia and treated with antibiotics, bronchoalveolar lavages were performed in attempt to follow the course of the biological disorders caused by the pulmonary bacterial infection. The cytologic study of the fluid harvested from 14 patients with normal immune reactivity showed, firstly, a polymorphonuclear leucocytosis and, after about ten days, a lymphocytosis, reaching 30 to 70% of the alveolar cell population. These cell disorders existed only in the lobe affected by the pneumonia process. In five alcoholics (one of them also splenectomized), the polymorphonuclear leucocytosis lasted 15 to 25 days and the lymphocytosis was delayed and moderate. We also searched for the pneumococcal antigen by counter-current immunoelectrophoresis using a polyvalent antiserum. We found it in 13 patients, 7 with a positive hemoculture for pneumococcus and 6 negatives. Clearance of this antigen was slow, non modified by alcoholism. We found this antigen in two patients later, between the 90th and 110th days, in the lavage fluid concentrated fifty times. The quantitative and qualitative study of the immunoglobulins revealed considerable individual variations, owing to the variable intensity of the local inflammation phenomenons and to the technical difficulties of their dosage in the lavage fluid.

Adolescent↗