The SIGMA rat brain templates and atlases for multimodal MRI data analysis and visualization.

Preclinical imaging studies offer a unique access to the rat brain, allowing investigations that go beyond what is possible in human studies. Unfortunately, these techniques still suffer from a lack of dedicated and standardized neuroimaging tools, namely brain templates and descriptive atlases. Here, we present two rat brain MRI templates and their associated gray matter, white matter and cerebrospinal fluid probability maps, generated from ex vivo [Formula: see text]-weighted images (90 µm isotropic resolution) and in vivo T2-weighted images (150 µm isotropic resolution). In association with these templates, we also provide both anatomical and functional 3D brain atlases, respectively derived from the merging of the Waxholm and Tohoku atlases, and analysis of resting-state functional MRI data. Finally, we propose a complete set of preclinical MRI reference resources, compatible with common neuroimaging software, for the investigation of rat brain structures and functions.

Genetically tailored magnetosomes used as MRI probe for molecular imaging of brain tumor.

We investigate here the potential of single step production of genetically engineered magnetosomes, bacterial biogenic iron-oxide nanoparticles embedded in a lipid vesicle, as a new tailorable magnetic resonance molecular imaging probe. We demonstrate in vitro the specific binding and the significant internalization into U87 cells of magnetosomes decorated with RGD peptide. After injection at the tail vein of glioblastoma-bearing mice, we evidence in the first 2 h the rapid accumulation of both unlabeled and functionalized magnetosomes inside the tumor by Enhanced Permeability and Retention effects. 24 h after the injection, a specific enhancement of the tumor contrast is observed on MR images only for RGD-labeled magnetosomes. Post mortem acquisition of histological data confirms MRI results with more magnetosomes found into the tumor treated with functionalized magnetosomes. This work establishes the first proof-of-concept of a successful bio-integrated production of molecular imaging probe for MRI.

[Staphylococcal tracheitis and toxic shock syndrome in a child]. / Laryngotrachéite à staphylocoque doré compliquée d'un syndrome de choc toxique.

Bacterial tracheitis should be raised as a possible cause in cases of severe febrile dyspnea. It can be life-threatening due to airway obstruction or, less frequently, due to toxic shock syndrome. We report the observation of toxic shock syndrome-complicated bacterial tracheitis in a 14-year-old boy. We describe the signs and symptoms of these conditions as well as the principles of treatment.

[Evolution of antibiotic resistance and serogroups of Streptococcus pneumoniae over the 1997-2003 period in Brittany]. / Evolution de la résistance aux antibiotiques et des sérogroupes de Streptococcus pneumoniae en Bretagne entre 1997 et 2003.

At this time, many antibiotics have decreased activity against Streptococcus pneumoniae, a major agent of infectious disease. In this study, we evaluated antibiotic susceptibility and serogroups of strains isolated from bacteraemia, meningitis and acute otitis media in adults and children over the 1997-2003 period in Brittany, France. In 2003, 62% of the isolates were not susceptible to penicillin and 11% were fully resistant. The prevalence of erythromycin resistance was 63%. Resistance rates were higher among isolates recovered from children than adults. Serogroups 19 and 14 were the most frequently isolated, especially the 19 one among children. The emergence of this serogroup might be a consequence of the use of heptavalent conjugate vaccine introduced in 2001 in France. Future surveillance after vaccination will be needed to detect emerging serogroups and resistance among S. pneumoniae.

[Antibiotics resistance of Streptococcus pneumoniae. Results from the Brittany registry for 1999]. / Etat de la résistance aux antibiotiques de Streptococcus pneumoniae dans la région Bretagne. Résultats de l'Observatoire Régional du Pneumocoque pour l'année 1999.

Throughout 1999, clinical microbiology laboratories of 13 hospitals in Brittany have recovered Streptococcus pneumoniae isolates in 832 patients, 312 (37.5%) female and 518 (62.2%) male. Two hundred fifty five of them (30.6%) were children. One hundred eighty eight isolates were recovered from blood cultures (22.6%), 16 from CSF (1.9%), 449 from lungs (54%), and 88 from ear exsudates (10.6%).A 5 microgram oxacillin-disk test was used to detect isolates with reduced susceptibility to penicillin G. Determination of MICs of penicillin G, amoxicillin and cefotaxime were then performed by agar dilution method on 402 strains previously categorized resistant or intermediate. Five hundred forty six isolates were PSDP, 33.5% of them were resistant to penicillin G, 2.2% to amoxicillin and 0.2% to cefotaxime. As expected, a decreased susceptibility to beta-lactamins was frequently associated with resistance to macrolides, cotrimoxazole and tetracycline. Among PSDP, the most prevalent serotypes were 23 (23.7%), 14 (23.5%) and 19 (19.1%). In Brittany, the constant rise of PSDP (1993-1994: 28.5%; 1997: 56.4%; 1999: 65.6 %) could be perhaps explain by analysis of social and demographic data.

In vitro activity of teicoplanin against gram-positive cocci.

The glycopeptide susceptibility of 443 clinical isolates of gram-positive cocci collected from nine general hospitals in 1996 was determined according to the recommendations of the CA-SFM (the Antibiogram Committee of the French Society for Microbiology). In total, 234 isolates of Staphylococcus aureus, 84 isolates of coagulase-negative staphylococci (CNS), 98 enterococci and 27 streptococci were collected. The mecA gene confirming resistance to methicillin was found in 42.7% of S. aureus isolates and 51.2% of CNS isolates. No resistance to teicoplanin and vancomycin was found in S. aureus but four isolates of CNS had an MIC of teicoplanin > or = 8 mg/L. All isolates of Enterococcus faecalis tested were susceptible to both glycopeptides. This study confirms that teicoplanin has a very good in vitro activity against gram-positive cocci, isolated in France from nosocomial infections.

Allele frequencies of hereditary hemochromatosis gene mutations in a local population of west Brittany.

Hereditary hemochromatosis (HH) gene mutations, C282Y and H63D, have been screened in a cohort of 254 presumably healthy persons originating from a western region of France. The carrier frequencies of these mutations and the incidence of HH have been estimated and compared with those of other studies. This cohort contains two C282Y/C282Y genotypes and has the highest C282Y heterozygosity frequency (17.46%) ever reported.