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P Geslin

Publications and source records attributed to P Geslin.

At least 55 records · Page 3Linked to original sources
PubMed1998

Comparative in vitro killing activities of meropenem, imipenem, ceftriaxone, and ceftriaxone plus vancomycin at clinically achievable cerebrospinal fluid concentrations against penicillin-resistant Streptococcus pneumoniae isolates from children with meningitis.

The activities of meropenem, imipenem, ceftriaxone, and vancomycin were evaluated against 80 penicillin-susceptible and -resistant Streptococcus pneumoniae strains. Meropenem, imipenem, ceftriaxone, and vancomycin MICs at which 90% of the isolates are inhibited were 0.5, 0.25, 1, and 0.25 microg/ml, respectively. Against penicillin-resistant strains, the best killing activity at cerebrospinal fluid concentrations was obtained with imipenem and ceftriaxone-vancomycin. However, while the killing activity of imipenem was significantly greater than that of meropenem, no significant difference was observed between the activities of meropenem and ceftriaxone-vancomycin.

Anti-Bacterial Agents↗
PubMed1998

[Measurement of the left ventricular mass using MRI with automatic determination of the endocardial and epicardial contours].

This study describes a method of automatic border detection of the left ventricular endocardium and epicardium associating three methods of segmentation (increase of region, border detection and adaptive threshold), applicable to the evaluation of ventricular mass and volume by magnetic resonance imaging. Despite slight underestimation, the spin-echo sequence used in 9 small pigs provided a value of left ventricular mass close to that observed ex vivo (r = 0.97, SEE = 6.05 g). Clinical validation using a rapid gradient-echo sequence was undertaken and compared with manual border detection carried out by three independent, trained operators. The study population included healthy subjects and patients with global or segmental left ventricular dysfunction with or without ventricular deformation. The correlations between automatic and manual detection were satisfactory both for calculation of left ventricular mass (r = 0.93, SEE = 13 g) and measurement of surfaces (r = 0.91, SEE = 1.4 cm2). The concordance of the two methods was confirmed by the Bland and Altman test. Cardiac magnetic resonance imaging may provide accurate and reproducible measurements of left ventricular mass within acceptable acquisition and image processing times for routine use. Although the clinical value of such a method is accepted both for establishing the prognosis and guiding management, studies of the cost/efficacy ratio should be undertaken to situate magnetic resonance imaging with respect to other non-invasive techniques of investigation of left ventricular function.

Adult↗
PubMed1998

[Renovascular hypertension due to renal artery thrombosis].

The authors report the case of a 74 year old woman admitted to hospital for severe hypertension with unilateral renal artery thrombosis. Recanalisation of the renal artery was obtained by transluminal angioplasty leading to rapid control of the hypertension. Dynamic renal scintigraphy with MAG 3 confirmed the viability of the kidney distal to the thrombosis and, secondarily, the functional recovery of the affected kidney.

Aged↗
PubMed1998

[Plasma noradrenaline and the prognosis of chronic cardiac failure: a multicenter study].

Plasma noradrenaline is little used in evaluating the prognosis of cardiac failure because of the theoretical necessity of interrupting treatment for a few days before blood sampling. The present study reevaluated the prognostic value of this parameter with blood sampling performed during treatment and then 48 hours after withdrawal of treatment in 192 patients with chronic stable cardiac failure at an advanced stage (64% of patients in Classes III or IV with an average ejection fraction of 28.5 +/- 13.5%). During follow-up (average 43 months) there were 51 deaths and 17 transplants. None of the patients were lost to follow-up. Univariate analysis of 52 variable observers during the initial phase of evaluation found in decreasing order of predictive value for death plasma noradrenaline levels before and after withdrawal of treatment for 48 hours. Serum sodium, age, systolic mean and diastolic pulmonary artery pressures. In multivariate analysis: noradrenaline with or without withdrawal of treatment, hyponatraemia and systolic pulmonary artery pressure. Actuarial survival curves distinguished the following parameters: noradrenaline levels became predictive at concentrations of over 210 pg/mL and there was a significant difference in survival with respect to 4 levels of serum noradrenaline (with or without treatment) > 300 pg/mL, 300 to 600 pg/mL and > 900 pg/mL. This serum noradrenaline measured without withdrawal of treatment (especially angiotensin converting enzyme inhibitors) is a powerful predictor of mortality, carrying a progressively poorer prognosis as the concentration increases.

Adult↗
PubMed1998

[Presumptive tests and molecular hybridization for the identification of untypable strains of Streptococcus pneumoniae].

Five different methods for identification of pneumococci (optochine susceptibility, bile solubility, Slidex Pneumo-kit, Phadebact Pneumococcus test, AccuProbe DNA test) were evaluated with a total of 280 Streptococcus pneumoniae non typable strains. 189 strains were identified as pneumococci according to the AccuProbe test results. Among these, 180 strains (95.2%) were optochine sensitive (d > or = 12 mm). Bile solubility was seen in 125 (66.1%) of the pneumococci. Immunological identifications were respectively positive for 67 and 56 among 140 strains. By comparison with the DNA/RNA reassociation method, the poor sensitivities and specificities of the presumptive identification tests are actually demonstrated for pneumococcal non typable strains. Thus, the AccuProbe DNA test is seen as the only adequate method for identification of such strains.

Bacterial Typing Techniques↗
PubMed1998

[Streptococcus pneumoniae: serotypes, invasive and antibiotic resistant strains. Current situation in France].

OBJECTIVES: Anti-pneumococcal antibiotic therapy has reduced morbidity and mortality of pneumococcal infections, but this success has retarded wide application of vaccination. The emergence and worldwide diffusion of antibiotic-resistant strains raises an important public health problem. The current situation requires determining the respective roles of antibiotic therapy and vaccine immunoprophylaxy. The aim of this work was to examine the data collected by the French National Pneumococci Registry. METHODS: The Nation Surveillance Network for Pneumococcal Infections was initiated in France in 1984. With this registry, it has been possible to follow regularly the evolution of serotypes and their sensitivity to antibiotics in 34,130 strains received from 1984 to 1996 and to compare these results with the clinical data. RESULTS: Serotyping the invasive strains has shown that the relative frequency of these serotypes has been stable: the 23-valence pneumococca vaccine provided good serotype coverage from 1984 to 1996 (87.2% of the invasive strains isolated in 1996 belonged to the vaccine types). Penicillin-resistant pneumococci comprised 3.8% of the strains, isolated in 1987 and 42.8% of those isolated in 1996. Two-thirds of these penicillin-resistant pneumococci had high-level resistance and an equivalent percentage were multiresistant. The consequences of resistant strains on antibiotic therapy for pneumonia, acute otitis and meningitis is discussed. CONCLUSION: Bacterio-clinical surveillance networks provide regular epidemiological data aimed at better use of antibiotics and the promotion of vaccination campaigns. In the future, the vaccination of children under 2 years of age with new conjugated polysaccharide vaccines should be an essential step in the global strategy against pneumococcal infections. The vaccinal formula of such a pediatric vaccine would contain 10 valences, defined according to the serotype results we have obtained: 1, 3, 4, 6, 7, 9, 14, 18, 19, 13. This vaccine would cover 86.1% of the invasive strains and 90.7% of the strains isolated from children with acute otitismedia.

Anti-Bacterial Agents↗
PubMed1997

Structural organization of the Streptococcus pneumoniae chromosome and relatedness of penicillin-sensitive and -resistant strains in type 9V.

Fragmentation of Streptococcus pneumoniae genomic DNA with low-frequency-cleavage restriction endonucleases and separation of the fragments by field-inversion gel electrophoresis (FIGE) provides a DNA-fingerprint of a strain. This method enables us to construct a physical and genetic map of the R6 laboratory strain what will be presented. The origin of replication containing several Dna boxes was located in the dnaA region. It was of interest to compare the profiles of subclones. Two clones of strain R36A (R6 and C13) were cultivated separately for more than 15,000 generations in two laboratories. FIGE profiles differed by only one band. Another R36A descendant, isolated in 1958 by Ravin, strain Rx was of interest since it was deficient in Dpn restriction enzymes and methylases and in the hex B function. Its origin was questionable; its profile is identical to others R6 descendants, demonstrating that Rx is derived from R36A. FIGE analysis was carried out on several penicillin-resistant strains of type 9V because penicillin-resistance in this type increased recently. The profiles of a collection of a number of these resistant isolates were very similar, showing that they result from a clone. The profiles of penicillin sensitive isolates of the same type are very similar to the resistant isolates. This suggests that the 9V type has spread recently from a clone, and the resistance genes have mutated and were selected when penicillin was extensively used.

Blotting, Southern↗
PubMed1997

In-vitro killing activity of combinations of beta-lactam agents with aminoglycosides against penicillin-resistant pneumococci.

Streptococcus pneumoniae has developed resistance to almost every antibacterial agent used in clinical practice, including the most active beta-lactams. This has led to the proposed use of drug combinations. The aim of this study was to determine the efficacy of combinations of beta-lactam agents (cefotaxime or imipenem) with aminoglycosides (gentamicin, netilmicin or amikacin) against pneumococci showing high-level resistance to penicillin and streptomycin and/or kanamycin. All tested combinations were bactericidal and synergic despite the weak concentrations of antibiotics used. Our results suggest that combinations of beta-lactam agents with aminoglycosides may be useful for treating infections by penicillin-resistant pneumococci located outside the central nervous system.

Aminoglycosides↗
PubMed1997

Change in nasopharyngeal carriage of Streptococcus pneumoniae resulting from antibiotic therapy for acute otitis media in children.

BACKGROUND: Acute otitis media is the leading reason for antibiotic prescriptions in childhood. The increase in antibiotic resistance of Streptococcus pneumoniae is generally attributed to the extensive use of antibiotics and the selective pressure on the bacterial strains of the nasopharyngeal flora. OBJECTIVE: To evaluate the change in nasopharyngeal carriage of S. pneumoniae during antibiotic therapy prescribed for acute otitis media. METHODS: Between October, 1993, and March, 1994, we conducted a clinical trial comparing cefpodoxime-proxetil and amoxicillin-clavulanate in acute otitis media. From 364 children, 4 months to 4.5 years old, a nasopharyngeal sample was obtained before and after treatment. Antibiotic susceptibility was established by determining minimal inhibitory concentrations by the agar dilution method. Serotype and randomly amplified polymorphic DNA analysis were used to compare pre- and posttreatment S. pneumoniae strains. RESULTS: The risk for a child to carry penicillin-resistant S. pneumoniae (MIC > or = 0.125 mg/l) did not increase after antibiotic treatment: 84 of 364 (23.1%) before, 70 of 364 (19.2%) after. There was a significant decrease of penicillin-susceptible S. pneumoniae carriage, 117 of 364 (32.1%) before treatment compared with 24 of 364 (6.6%) (P = 0.0001) after treatment. However, among the children carrying S. pneumoniae at the end of the treatment there was an increase in the percentage of penicillin-resistant pneumococci: 84 of 201 (41.8%) before treatment and 70 of 94 (74.5%) after treatment. Among the 94 children carrying S. pneumoniae at the end of the treatment, 22 did not harbor pneumococcus before, 16 carried another genotypically different serotype and 56 harbored the same serotype. Among these 56 children 2 patients harbored strains that had increased MICs for the tested beta-lactam antibiotics. The randomly amplified polymorphic DNA analysis showed that in one case, the strains were genetically different. CONCLUSIONS: These data illustrate that antibiotic therapy did not increase the rate at which children carried penicillin-resistant S. pneumoniae, but there was an increase in the rate of resistance among the children carrying pneumococci at the end of the treatment, mainly as a result of reduction of susceptible strains.

Acute Disease↗
PubMed1997

Western blot analysis of antibody response to pneumococcal protein antigens in a murine model of pneumonia.

To detect new antigen candidates for serological tests, we studied the antibody response to pneumococcal protein antigens in mice infected intratracheally with various Streptococcus pneumoniae strains. Sera were tested by Western blotting against whole-cell protein extracts. Mice developed a detectable immunoglobulin G-type response against a small number of polypeptides. The antibody response was strain dependent: sera from individuals infected with the same strain gave similar banding patterns on immunoblots. The banding patterns varied with the strain used for infection. However, a band at 36 to 38 kDa was recognized by all reactive sera. This band appeared to correspond to a polypeptide that was antigenically well conserved among the different S. pneumoniae serotypes. An antibody response to this antigen developed in mice irrespective of the capsular type, the virulence, and the susceptibility to penicillin G of the infecting strain. Thus, this 36- to 38-kDa protein antigen may be of value for the development of a serological test for humans.

Animals↗
PubMed1997

Molecular epidemiology of Streptococcus pneumoniae with decreased susceptibility to penicillin in a Paris children's hospital.

Among pneumococci with decreased susceptibility or pneumococci resistant to penicillin (PRP) isolated at Armand-Trousseau children's hospital, those expressing capsular serotypes 23F, 9V, and 14 were the most frequently isolated. We compared 53 clinical isolates (14 type 9V, 26 type 23F, and 13 type 14) by analysis of chromosomal macrorestriction patterns and DNA restriction patterns of the penicillin-binding protein (PBP) genes pbp 2b, pbp 2x, and pbp 1a. All 9V isolates originated from the same clone. Five 23F clones were distinguished, the largest of which comprised 20 isolates. The main type 14 clone comprised nine isolates; three other type 14 strains were closely related to the 9V clone, probably by horizontal transfer of capsular biosynthesis genes. Most 23F and type 14 isolates shared the same PBP gene restriction patterns as the 9V clone, suggesting horizontal transfer of altered PBP genes.

Child↗
PubMed1997

[Value of MRI with injection of gadolinium in the diagnosis of mitral ring abscess. Apropos of a case].

Transoesophageal echocardiography is the investigation of choice for the diagnosis of valvular vegetations in infectious endocarditis but the diagnosis of an associated ring abscess is sometimes difficult especially in patients with valvular prostheses or calcifications which are in important source of artefacts. The authors report a case of mitral annular abscess confirmed at surgery and comment on the diagnostic and prognostic value of cardiac MRI. MRI showed an abnormal cavity directly related to the mitral annulus and separated from the left ventricle by a low intensity signal which increased after injection of gadolinium suggesting an inflammatory origin and therefore arising from the abscess. The cavity was heterogeneous in T1 associating zones of low intensity with high intensity signals increasing in T2 on the second echo (thrombus and necrosis). Cine-MRI showed non communication between the abscess cavity and the left ventricle or atrium.

Abscess↗
PubMed1997

Streptococcal pyrogenic exotoxin A, streptolysin O, exoenzymes, serotype and biotype profiles of Streptococcus pyogenes isolates from patients with toxic shock syndrome and other severe infections.

The determination of protein M and T serotypes, biotypes and pyrogenic (erythrogenic) exotoxin A (SPE A), streptolysin O (SLO), streptokinase (SK), hyaluronidase (HA) and cysteine proteinase release by 212 S. pyogenes isolates from patients with severe invasive group A streptococcal (GAS) infections, among them 74 cases of streptococcal toxic shock syndrome (STSS) has been investigated. M1 or M3 serotypes were expressed by 25% of the isolates (53/212), whereas 59% (125/212) belonged to 15 other different serotypes and 16% (34/212) were untypeable. Of the 74 isolates from STSS patients, 42% (31/74) expressed M1 and to a lesser extent M3 serotypes versus 19% of the non STSS isolates (26/138). Among the ten different biotypes known, biotypes 1 and 3 were prevalent, particularly the former in the case of STSS isolates. SPE A was detectably produced by about 25% (54/212) of the strains. However, as high as 40.5% of the STSS isolates (30/74) versus 17.4% of non STSS isolates (24/138) released SPE A. Moreover, 67% of the SPE A producing strains were of serotype M1 or M3. SK and HA were released by 71% and 10% of the isolates respectively. All strains released SLO (4 to 256 HU/ml) and 85% cysteine proteinase. No relationship between toxin or enzyme titer and the type of disease or clinical origin of the strains was found. Culture supernatants of all isolates showed moderate to high lymphocyte transforming activity with index values ranging from 14.5 to 50.3 including those strains which did not release detectable amounts of SPE A suggesting that SPE C and other mitogenic factor(s) are released by the isolates investigated.

Adolescent↗
PubMed1996

[Increase of sialic acid concentration in the plasma of patients with coronary disease].

OBJECTIVES: Plasma levels of sialic acid are elevated in patients with coronary heart disease. We evaluated the specificity of this increase and attempted to correlate it with the severity of coronary lesions. METHODS: Total plasma sialic acid levels measured in 60 control subjects were compared with that in 135 patients with heart disease requiring coronarography. RESULTS: Plasma levels of sialic acid were significantly higher in patients (664 +/- 146 mg/l) than in controls (584 +/- 100 mg/l). In the group of patients, sialic acid level was only increased in those with coronary lesions - infarcts (738 +/- 166 mg/l) and angina (664 +/- 121 mg/l) - but was not raised above normal levels in those with other heart diseases (cardiomyopathy, valve failure, etc.). There was a positive correlation (p < 0.001) between raised sialic acid level and the severity of the coronary lesions as measured on coronarography. CONCLUSIONS: The elevated level of sialic acid in patients with coronary heart disease could be related to disorders in cell adhesion.

Adult↗