Search PubMed⌕ Search

Biomedical subjects

L Lebrun

Publications and source records attributed to L Lebrun.

At least 19 recordsLinked to original sources
PubMed2006

Respiratory infections associated with nontuberculous mycobacteria in non-HIV patients.

The incidence of nontuberculous mycobacteria (NTM) pulmonary diseases in HIV-negative patients was studied prospectively from January 1, 2001 to December 31, 2003 by 32 sentinel sites distributed throughout France. In total, 262 patients who yielded NTM isolates from respiratory clinical specimens, met the bacteriological, radiological and clinical criteria established by the American Thoracic Society for NTM respiratory disease. Among the 262 NTM isolates, 234 were slow-growing mycobacteria (125 Mycobacterium avium-intracellulare complex (MAC), 66 M. xenopi, 34 M. kansasii) and 28 were rapidly growing mycobacteria (25 M. abscessus complex). In the Paris area, M. xenopi was the most frequently isolated species, followed by MAC. Most patients (>50%), except those with M. kansasii, had underlying predisposing factors such as pre-existing pulmonary disease or immune deficiency. Asthenia, weight loss, chronic cough and dyspnoea were the most common clinical symptoms. The classical radiological appearance of NTM infections was indistinguishable from that observed in patients with pulmonary tuberculosis. In summary, the incidence of nontuberculous mycobacteria pulmonary infections in HIV-negative patients was estimated at 0.74, 0.73 and 0.72 cases per 100,000 inhabitants in 2001, 2002 and 2003, respectively.

AIDS-Related Opportunistic Infections↗
PubMed2004

Investigations on ferroelectric PMN-PT and PZN-PT single crystals ability for power or resonant actuators.

Ferroelectric single crystals of PZN-PT and PMN-PT exhibit outstanding properties: high charge coefficient (dij), high coupling factor (kij) and high strain levels under DC fields. Besides, their mechanical quality factor is believed to be low. Their usefulness for non-resonant or large bandwidth transducers has therefore been previously investigated. However, few studies have been devoted to the dielectric and mechanical losses of single crystals and to their stability under high levels of excitations (electric fields, temperature and mechanical stress). A knowledge and understanding of such performances is needed to determine whether single crystals are suitable materials for power or resonant transducers. In this work, losses and non-linearity versus external excitations are investigated. Dielectric losses and mechanical losses are measured versus electric field for different compositions, orientations. The evolution of d33 and epsilonT33 are obtained versus electric field and temperature for the longitudinal mode. Strain and hysteresis versus sweep mode (up and down) are measured near the resonance frequency using a laser Doppler vibrometer.

Journal Article↗
PubMed2003

Emergence of nosocomial Pseudomonas aeruginosa colonization/infection in pregnant women with preterm premature rupture of membranes and in their neonates.

The epidemiology, risk factors, maternal and neonatal outcomes of nosocomial Pseudomonas aeruginosa acquisition in preterm premature rupture of membranes were analysed. Of 63 women receiving antibiotic prophylaxis with co-amoxiclav, 11 acquired P. aeruginosa vaginal carriage with a median delay of 15 days (6-42) i.e. an incidence of 8.94 per 1000 days of expectant management. Five neonates born to 11 positive mothers were colonized or infected, three of whom died of fulminant sepsis. The duration of antibiotic treatment and multiple pregnancy were identified as independent risk factors. The epidemiological investigation revealed a vertical transmission between mothers and neonates, and suggested selective pressure of antibiotic treatment.

Adult↗
PubMed2001

Molecular identification of TEM-1 beta-lactamase in a Pasteurella multocida isolate of human origin.

Two clinical strains of Pasteurella multocida were isolated from an HIV-infected patient who developed arthritis. Strain FB-1, which was isolated from a dog-bite wound, was resistant to narrow-spectrum penicillins. The second strain, FB-2, which was present in blood cultures as well as the dog-bite wound, was susceptible to all beta-lactam agents. Arbitrarily primedpolymerase chain reaction and pulsed-field gel electrophoresis revealed that these two isolates were genetically indistinguishable. 16S rDNA gene sequencing facilitated identification at the subspecies level. Amoxicillin resistance determinant was located on a highly unstable 4.3-kb plasmid, pFAB-1. Isoelectrofocusing and polymerase chain reaction amplification followed by sequencing revealed the presence of a pI 5.4 TEM-1 beta-lactamase. This description is the first of a TEM-1 Beta-lactamase' in a Pasteurella multocida strain of human origin.

Acquired Immunodeficiency Syndrome↗
PubMed2001

Neonatal group B streptococcal infection. Results of 33 months of universal maternal screening and antibioprophylaxis.

OBJECTIVE: To assess the efficacy and pitfalls of a protocol of generalized screening for group B Streptococcus (GBS) and intra-partum treatment of all carriers in a clinical setting. DESIGN: A descriptive study and comparison with an historical group. SETTING: A tertiary perinatal center. POPULATION: All women attending prenatal care in our center and delivered after 37 weeks were eligible. Study period ranged from January 1994 to September 1996. Comparison group consisted in deliveries of years 1992 and 1993. METHODS: Vaginal cultures were performed at 36 weeks on non-selective medium followed by intra-partum treatment of all carrier mothers. Rate of carriage, incidence of neonatal GBS sepsis, influence of risk factors and the reasons for failures were analysed. Comparison was made with an historical group. Statistical analysis was performed using a Chi-square test. RESULTS: There were 5374 term deliveries during the study. 3906 were screened (72.7%) and 559 of them found positive for GBS (14.3%). We observed 46 early-onset GBS diseases (0.86% of term-births). 43.5% of infections occurred in babies born from mothers without risks factors at delivery. Negative GBS cultures at sampling accounted for 43.5% of protocol failures. Comparison of the incidence of early-onset GBS disease with the previous two years showed a significant drop (1.45-0.86%, P<0.05). CONCLUSIONS: Our protocol revealed feasible and effective in reducing the incidence of early-onset GBS disease. Improvements must be studied particularly as to the predictive value of screening cultures.

Amoxicillin↗
PubMed2000

Seizures after stroke: a prospective multicenter study.

BACKGROUND: Studies of seizures after stroke have largely been retrospective, with small patient numbers and limited statistical analysis. Much of the doctrine about seizures after stroke is not evidenced based. OBJECTIVE: To determine the incidence, outcome, and risk factors for seizures after stroke. DESIGN: International, multicenter, prospective, analytic inception cohort study conducted for 34 months. PATIENTS AND SETTING: There were 2021 consecutive patients with acute stroke admitted to university teaching hospitals with established stroke units. After exclusion of 124 patients with previous epilepsy or without computed tomographic diagnosis, 1897 were available for analysis. Mean follow-up was 9 months. MAIN OUTCOME MEASURES: Occurrence of 1 or more seizures after stroke, stroke disability, and death after stroke. RESULTS: Seizures occurred in 168 (8.9%) of 1897 patients with stroke (28 [10.6%] of 265 with hemorrhagic and 140 [8.6%] of 1632 with ischemic stroke). On Kaplan-Meier survival analysis, patients with hemorrhagic stroke were at significantly greater risk of seizures (P =.002), with an almost 2-fold increase in risk of seizure after stroke (hazard ratio [HR], 1.85; 95% confidence interval [CI], 1.26-2.73; P =.002). On multivariate analysis, risk factors for seizures after ischemic stroke were cortical location of infarction (HR, 2.09; 95% CI, 1. 19-3.68; P<.01) and stroke disability (HR, 2.10; 95% CI, 1.16-3.82; P<.02). The only risk factor for seizures after hemorrhagic stroke was cortical location (HR, 3.16; 95% CI, 1.35-7.40; P<.008). Recurrent seizures (epilepsy) occurred in 47 (2.5%) of 1897 patients. Late onset of the first seizure was an independent risk factor for epilepsy after ischemic stroke (HR, 12.37; 95% CI, 4.74-32.32; P<. 001) but not after hemorrhagic stroke. CONCLUSIONS: Seizures occur more commonly with hemorrhagic stroke than with ischemic stroke. Only a small minority later develop epilepsy. Patients with a disabling cortical infarct or a cortical hemorrhage are more likely to have seizures after stroke; those with late-onset seizures are at greater risk of epilepsy.

Aged↗
PubMed2000

Fatal Mycobacterium tuberculosis brain abscess in an immunocompetent patient.

A non-HIV-infected 63-y-old woman presented seizures and coma during the course of Mycobacterium tuberculosis infection. Computerized tomography scan led to the diagnosis of a large compressive brain abscess. The patient died with multiorgan failure. Systematic central nervous system investigations should be done in cases of disseminated tuberculosis.

Brain Abscess↗
PubMed1998

Molecular fingerprinting of Mycobacterium tuberculosis and risk factors for tuberculosis transmission in Paris, France, and surrounding area.

Forty-three percent of the tuberculosis cases reported in France are from the Ile de France region. The incidence of tuberculosis in this region is 33 cases per 100,000 inhabitants, twice the national average. A restriction fragment length polymorphism (RFLP) analysis was performed with clinical isolates of Mycobacterium tuberculosis isolated during 1995 in 10 hospitals in Paris and surrounding areas to detect tuberculosis transmission and define the factors associated with clustering in this population. The molecular markers used were the insertion sequence IS6110 and the direct repeat (DR) sequence. Social, demographic, and clinical data were collected from the patients' medical files. Ten patients with isolates with a single copy of IS6110 were excluded from further analysis. Twenty-four patients with false-positive cultures due to laboratory contamination (based on RFLP analysis with IS6110 and examination of patient data) were also excluded. The study was then conducted with 272 strains isolated from 272 patients. Further fingerprinting was performed by using the DR element with strains with patterns by RFLP analysis with IS6110 that differed by one band only and strains with identical patterns by RFLP analysis with IS6110 and with low numbers of copies of IS6110. The combined use of both markers identified unique patterns for 177 strains and clustered 95 (35.7%) strains in 26 groups, each containing isolates from 2 to 12 patients. The clustering was strongly associated with homelessness and the male sex. It was not associated with age, birth in a foreign country, human immunodeficiency virus positivity, or residence in hostels or prison. Isolates from homeless people were often included in large clusters, and homeless people could be the source of tuberculosis transmission for more than 50% of the clustered patients. These results suggest that homeless people play a key role in the spread of M. tuberculosis in the community and that poor socioeconomic conditions are the main risk factors associated with active tuberculosis transmission.

AIDS-Related Opportunistic Infections↗
PubMed1998

Randomized, single-blinded comparative study of the efficacy of amoxicillin (40 mg/kg/day) versus standard-dose penicillin V in the treatment of group A streptococcal pharyngitis in children.

A 10-day course of amoxicillin at a dosage of 40 mg per kilogram per day was compared with conventional (lower dosage) penicillin V therapy in the treatment of culture-proven Group A streptococcal pharyngitis in children 3 to 18 years of age in a prospective, randomized, and single-blinded study. Children had to have signs and symptoms compatible with the diagnosis of streptococcal pharyngitis and to have a throat swab positive for Group A streptococci. A second throat culture was obtained 10 to 14 days after the completion of therapy. Serotyping was performed to help differentiate carrier states from reinfections. Of 161 children enrolled, 113 were evaluable; 55 received penicillin and 58 received amoxicillin. At the completion of therapy 70.9% (39/55) of patients in the penicillin group vs 87.9% (51/58) of patients in the amoxicillin group were asymptomatic (clinical cure, P = 0.025). At the completion of therapy, 54.5% (30/55) of patients in the penicillin group vs 79.3% (46/58) of patients in the amoxicillin group had negative throat cultures (bacteriologic cure, P = 0.005). The carrier rate (children who were well but who were still carrying the same serotype of Group A streptococcus) also differed between the groups: 13 (23.6%) in the penicillin group compared with six (10.3%) in the amoxicillin group. Amoxicillin at 40 mg/kg/day was significantly more effective than lower dosages of penicillin V for clinical and bacteriologic cure in the treatment of Group A streptococcal pharyngitis in children. The current perception that penicillin is declining in effectiveness may be due to inadequate dosing.

Adolescent↗
PubMed1997

Limits of commercial molecular tests for diagnosis of pulmonary tuberculosis.

Several studies report high specificity, but variable sensitivity, of Amplified Mycobacterium tuberculosis Direct Test (AMTDT, Gen-Probe) based on ribosomal ribonucleic acid (rRNA) amplification and Amplicor Mycobacterium tuberculosis test (Amplicor, Roche) based on deoxyribonucleic acid (DNA) amplification for diagnosis of pulmonary tuberculosis. We have retrospectively evaluated these assays on selected acid-fast bacilli (AFB)-positive and -negative smear specimens and compared the results obtained from nucleic acid amplification with those of AFB staining of semi-quantitative cultures as determined by radiometric Bactec and Löwenstein-Jensen cultures. In comparison to cultures, Amplicor and AMTDT assays exhibited identical overall sensitivities of 80%, while the staining had a lower sensitivity of 62%. The sensitivities of Amplicor and AMTDT were 98% and 100%, respectively, for the AFB-positive specimens, and 50 and 46%, respectively for the AFB-negative specimens in comparison to cultures. The sensitivities of both assays appeared similar, and were directly related to the number of bacilli in the specimens studied. The low sensitivity (50%) for smear-negative specimens showed that current amplification assays may be unsuitable to replace cultures for diagnosis of tuberculosis. The decision to perform these molecular techniques should result from close co-operation between clinicians and microbiologists, taking into account the sensitivity results reported here, as well as the expense of the assays.

DNA↗
PubMed1996

Evaluation of the Etest for rapid susceptibility testing of Mycobacterium avium to clarithromycin.

MICs of clarithromycin were determined by the Etest method for thirty clinical strains of Mycobacterium avium complex (MAC) and compared with MICs results as determined by the reference agar dilution method. Agreement (within +/- 1 log2 dilution) between the Etest and the reference method was 70% for susceptible strains and 100% for resistant strains. No major errors resulting in misclassification in susceptibility or resistance categories were detected for the Etest MIC method. It is suggested that the Etest is easy to perform and is an accurate method for determining susceptibility of MAC strains to clarithromycin.

Anti-Bacterial Agents↗