Search results for "halos"

FTIR and SAXS study on MBCO-saccharide amorphous systems: protein-matrix reciprocal effects

2010

Effects of gamma-irradiation on trehalose–hydroxyethylcellulose microspheres loaded with vancomycin

2003

Ionizing radiation can be used as a drug sterilization technique, provided that the drug itself is not modified and that no toxic products are produced; moreover, if the irradiated product is a drug delivery system, the drug release characteristics must not be significantly altered by radiation. The aim of this work was to study the effects of sterilization by ionizing radiation on hydroxyethylcellulose/trehalose spherical micromatrices, containing the antibiotic vancomycin. Our experimental results showed that gamma-rays did not alter the chromophore groups of vancomycin (UV measurements), and did not modify the kinetic behavior of drug release from microspheres. Moreover, no significant c…

Trehalose interacts with phospholipid polar heads in Langmuir monolayers

2000

Surface pressure−area isotherms, surface potential-area isotherms and fluorescence microscopy were employed to study the behavior of phospholipid monolayers at the air/water interface when trehalose was added to the aqueous subphase. In the presence of this sugar, the critical area corresponding to the onset of surface potential increases, indicating that trehalose is participating in the network of hydrogen bonds between the phospholipid polar heads. In addition, it causes an expansion of the isotherm, hindering the formation of the liquid-condensed phase. The collapse area is significantly increased, indicating that trehalose takes part in the monolayer structure without being expelled ev…

Reply to Comment on “Trehalose Interacts with Phospholipid Polar Heads in Langmuir Monolayers”

2002

Light-Induced Protein-Matrix Uncoupling and Protein Relaxation in Dry Samples of Trehalose-Coated MbCO at Room Temperature

2005

In humid samples of trehalose-coated carboxy-myoglobin (MbCO), thermally driven conformational relaxation takes place after photodissociation of the carbon monoxide (CO) molecule at room temperature. In such samples, because of the extreme viscosity of the external matrix, photodissociated CO cannot diffuse out of the protein and explores the whole (proximal and distal side) heme pocket, experiencing averaged protein heme pocket structures, as a result of the presence of Brownian motions. At variance, in very dry samples, a lower portion of the photodissociated CO diffuses from the distal to the proximal heme pocket side probing in nonaveraged structures. We revisit here the flash photolysi…

Transmission electron microscopical studies on some haemolymph proteins from the marine polychaete Nereis virens.

2001

Abstract The hexagonal bilayer haemoglobin molecule from Nereis virens has been investigated in a comparative study using several different negative stain electron microscopical specimen preparations (i.e. by conventional adsorption to continuous carbon support films, by the negative staining-carbon film technique and by negative staining across the holes of holey carbon support films with air-drying and rapid freezing/cryo-negative staining). The benefits and limitations of these different approaches are indicated, with the overall conclusion that negative staining with ammonium molybdate across holes creates the best possibilities for molecular imaging, and also has the potential for the …

Etestw versus broth microdilution for ceftaroline MIC determination with Staphylococcus aureus: Results from PREMIUM, a European multicentre study

2017

Objectives: To compare the concordance of ceftaroline MIC values by reference broth microdilution (BMD) and Etest (bioMérieux, France) for MSSA and MRSA isolates obtained from PREMIUM (D372SL00001), a European multicentre study. Methods: Ceftaroline MICs were determined by reference BMD and by Etest for 1242 MSSA and MRSA isolates collected between February and May 2012 from adult patients with community-acquired pneumonia or complicated skin and soft tissue infections; tests were performed across six European laboratories. Selected isolates with ceftaroline resistance in broth (MIC >1 mg/L) were retested in three central laboratories to confirm their behaviour. Results: Overall concordance…

Outbreak of IMI-1 Carbapenemase-producing colistin-resistant Enterobacter cloacae on the French island of Mayotte (Indian Ocean)

2018

International audience; The spread of carbapenemase-producing Enterobacteriaceae in the Southwest Indian Ocean islands is poorly known. Here we describe an outbreak of colistin-resistant Enterobacter cloacae harbouring blaIMI-1 in the French overseas department of Mayotte. Between October 2015 and January 2017, all isolates of imipenem-non-susceptible E. cloacae at Mayotte Medical Center and University Hospital of Reunion Island were screened for carbapenemase production. Positive isolates were typed by pulsed-field gel electrophoresis and whole-genome sequencing (WGS)-based multilocus sequence typing (MLST), and all β-lactamase genes were identified by PCR and sequencing. Resistance profil…

Cerebrospinal fluid pharmacokinetics of ceftaroline in neurosurgical patients with an external ventricular drain

2019

IF 5.217; International audience; BackgroundOwing to its antibacterial properties, ceftaroline could be attractive for prevention or treatment of bacterial post-neurosurgical meningitis/ventriculitis. However, few data are available concerning its meningeal concentrations.ObjectivesTo investigate ceftaroline CSF pharmacokinetics in ICU patients with an external ventricular drain (EVD).MethodsPatients received a single 600 mg dose of ceftaroline as a 1 h intravenous infusion. Blood and CSF samples were collected before and 0.5, 1, 3, 6, 12 and 24 h after the end of the infusion. Concentrations were assayed in plasma and CSF by LC–MS/MS. A two-step compartmental pharmacokinetic analysis was c…

Analysis of ceftriaxone and ceftazidime distribution in cerebrospinal fluid of and cerebral extracellular space in awake rats by in vivo microdialysis

1995

In vivo microdialysis was used to estimate the extracellular concentrations of ceftazidime and ceftriaxone, two expanded-spectrum cephalosporins commonly used in the treatment of bacterial meningitis, in two brain regions (the right corpus striatum and the left lateral ventricle) of awake, freely moving rats. Antibiotics were administered by constant intravenous infusion at 18 mg/h until steady-state levels were reached. Ceftriaxone levels measured at the steady state in the extracellular space of the corpus striatum (0.80 ± 0.17 J.tg/ml) were statistically equivalent to those obtained in the cerebrospinal fluid of the lateral ventricle (0.71 ± 0.15 J.tg/ml). The ratios of these levels in t…