Contrasting effects of human THP-1 cell differentiation on levofloxacin and moxifloxacin intracellular accumulation and activity against Staphylococcus aureus and Listeria monocytogenes.

Background And Aims: Listeria monocytogenes and Staphylococcus aureus invade and multiply in THP-1 monocytes. Fluoroquinolones accumulate in these cells, but are less active against intracellular than extracellular forms of L. monocytogenes and S.

Factors compromising the activity of moxifloxacin against intracellular Staphylococcus aureus.

Objectives: The aim of this study was to determine the intracellular activity of moxifloxacin against a reference strain and a clinical strain and to study the factors compromising the intracellular activity of moxifloxacin.

Methods: The bactericidal activity of moxifloxacin at therapeutic concentrations was studied against extracellular (broth) and intracellular (infected THP-1 monocytes) forms of Staphylococcus aureus and compared with that of levofloxacin. The activity of moxifloxacin was also evaluated in the presence of alkalinizing agents, in intracellular salt medium mimicking the phagolysosomal environment and in cell lysate.

Synthesis of omeprazole analogues and evaluation of these as potential inhibitors of the multidrug efflux pump NorA of Staphylococcus aureus.

A series of 11 pyrrolo[1,2-a]quinoxaline derivatives, 1a to 1k, sharing structural analogies with omeprazole, a eukaryotic efflux pump inhibitor (EPI) used as an antiulcer agent, was synthesized. Their inhibitory effect was evaluated using Staphylococcus aureus strain SA-1199B overexpressing NorA. By determinations of the MIC of norfloxacin in the presence of these EPIs devoid of intrinsic antibacterial activity and used at 128 microg/ml, and by the checkerboard method, compound 1e (MIC decrease, 16-fold; fractional inhibitory concentration index [SigmaFIC], 0.

Factors influencing the intracellular activity of fluoroquinolones: a study using levofloxacin in a Staphylococcus aureus THP-1 monocyte model.

Objectives: Recent studies have raised the question of whether the intracellular activity of quinolones is optimal with respect to their cellular accumulation. The aim of this study was to compare the intracellular and extracellular activities of a commonly used quinolone, levofloxacin, and to examine the causes of the possible inconsistency between intracellular and extracellular effects.

Methods: The bactericidal activity of levofloxacin at therapeutic levels, alone or in combination with various efflux-pump inhibitors or alkalinizing agents, was studied against Staphylococcus aureus ATCC 25923 in Mueller-Hinton (MH) broth and in a THP-1 monocytic cell model, using intracellular salt medium (ISM) mimicking the phagolysosomal environment, and in cell lysate.

Protonation equilibrium and lipophilicity of moxifloxacin.

This study was performed to characterise the protonation equilibrium at the molecular level and pH-dependent lipophilicity of moxifloxacin. After determining macro- and micro-constants, distribution features of four microspecies in aqueous phase were assessed. The apparent partition coefficient versus pH profile of moxifloxacin showed a parabolic curve in n-octanol/buffer system which reached near pI.

Simultaneous determination of levofloxacin, gatifloxacin and moxifloxacin in serum by liquid chromatography with column switching.

Liquid chromatography with a column-switching technique was developed for simultaneous direct quantification of levofloxacin, gatifloxacin and moxifloxacin in human serum. Serum samples were injected on a LiChroCART 4-4 pre-column (PC) filled with a LiChrospher 100 RP-18, 5 microm where fluoroquinolones (FQs) were purified and concentrated. The FQs were back-flushed from the PC and then separated on a Supelcosil ABZ+ Plus (150 mm x 4.

High-performance liquid chromatographic separation of fluoroquinolone enantiomers: a review.

Fluoroquinolones are antibacterial agents widely used clinically. In recent years, there has been an important development of new derivatives, and more than 7000 analogues have been described today. Different fluoroquinolones (FQ) have one or two chiral centers in their chemical structure and are available as racemates, diastereoisomers, or pure enantiomers.

Discrepancy between uptake and intracellular activity of moxifloxacin in a Staphylococcus aureus-human THP-1 monocytic cell model.

The correlation between uptake of moxifloxacin by THP-1, a continuous line of monocytic cells devoid of intrinsic bactericidal properties, and its activity against Staphylococcus aureus ATCC 25923, a susceptible reference strain (MIC and minimal bactericidal concentration of moxifloxacin, 0.1 mg/liter), was studied in a 5-h assay. The uptake of the drug, added to the culture medium at 0.

Uptake of quinolones by in-vitro human monocyte derived macrophages.

We have developed an in-vitro model of monocyte-derived macrophage (MDMphi) to compare fluoroquinolone uptake in monocytes and derived macrophages. Monocyte-derived macrophages were obtained in-vitro by cultivating freshly isolated monocytes for seven days in RPMI 1640 medium, containing foetal calf serum and Rhu granulocyte-macrophage colony stimulating factor. Final suspensions contained 95% viable cells and 63% macrophages.

[Audit on pelvimetry at a polyvalent radiology department].

Purpose: Study of the dose absorbed by the fetus during CT pelvimetry.

Material And Methods: Twenty consecutive pelvimetries on pregnant women showed the mean fetal location in regard of the maternal pelvic skeleton (retrospective study). Then, thermoluminescent radiation detectors were put in the antropomorph phantom slices, in housing correspondent to the fetal's volume.

Determination of phosphonoformate (foscarnet) in calf and human serum by automated solid-phase extraction and high-performance liquid chromatography with amperometric detection.

An isocratic high-performance liquid chromatographic method with automated solid-phase extraction has been developed to determine foscarnet in calf and human serums. Extraction was performed with an anion exchanger, SAX, from which the analyte was eluted with a 50 mM potassium pyrophosphate buffer, pH 8.4.

Uptake of fluoroquinolones in human monocytes isolated from peripheral blood.

The aim of this study was to develop a technique for separating monocytic cells in suspension from peripheral blood to measure the intracellular penetration of three fluoroquinolones (ofloxacin, ciprofloxacin and sparfloxacin). Mononucleated cells were isolated from the blood on a density gradient with lymphoprep and purified by a specific technique of adhesion and disadhesion on fibronectin. The monocytes were obtained in suspension with 76.

[Imaging of small renal tumors].

The increased incidence of detection of small renal tumours, less than or equal to 3 cm in diameter, is related to the generalization and improvement of radiological techniques. Many asymptomatic renal tumours are discovered by ultrasonography and computed tomography. Medical imaging is now able to identify simple cysts (morphological characters, absence of blood supply), angiomyolipomas (demonstration of the fatty contingent) and other solid renal tumours (tumour enhancement on computed tomography).

Demonstration of efficacy of combining corticosteroids and colchicine in two patients with idiopathic sclerosing mesenteritis.

Sclerosing mesenteritis is an uncommon condition of unknown etiology. It is likely to be the fibrous evolution of mesenteric panniculitis. It often has an indolent course but may be complicated by progressive bowel obstruction.

Comparative uptake of sparfloxacin and ciprofloxacin into human THP 1 monocytic cells.

The uptake of sparfloxacin (CAS 11542-93-9) by human monocytes was studied by comparison with ciprofloxacin (CAS 86393-32-0). The human monocytic THP 1 cells were incubated with the antibiotics for 2 h. Entry of antimicrobials into the cells was determined by means of a velocity gradient centrifugation technique and HPLC assay.

Iohexol in patients undergoing urography: a comparison of polypropylene containers (Unique Soft Pack) and glass vials.

The purpose of the present phase IV multicentre trial was to evaluate general patient tolerance to Omnipaque 350 mgI/ml (iohexol) supplied in polypropylene containers compared to that of the same product supplied in routinely used glass vials, with emphasis on allergy-like adverse events. Polypropylene is a pure plastic material with practically no additives, and has been tested in vitro as a contrast medium packaging material for several years. Handling of these containers is easier and safer than handling of glass vials.

[Transplacental passage of epirubicin].

We studied the transplacental transfer of epirubicin, an anthracycline used for the treatment of different neoplastic disorders, in particular breast cancers, by in vitro perfusion of term human placenta. Placenta from women with uncomplicated pregnancy were collected immediately after vaginal delivery and put into 37 degrees C thermostated hood. Perfusion of foetal surface of the placenta by modified Earle's solution was started immediately after catheterisation at a flow rate of 6 ml/min and then so was the perfusion of the intervillous space at the rate of 12 ml/min.

Liver metastases: safety and efficacy of detection with superparamagnetic iron oxide in MR imaging.

Purpose: To evaluate the clinical and biologic safety of superparamagnetic iron oxide (SPIO) as a contrast agent in magnetic resonance (MR) imaging and to assess its efficacy in the detection of liver metastases.

Materials And Methods: Twenty adults with liver metastases underwent MR imaging at 1.5 T before and 1 hour after infusion of SPIO.

Rectal malacoplakia in renal transplantation: MR features.

This report describes the CT and MRI features of rectal malacoplakia in a renal transplant recipient. The lesion appeared strongly hyperdense (105 HU) on unenhanced CT and demonstrated hypointense signal on T1- and T2-weighted MR imaging with slight homogeneous enhancement after gadolinium injection. These characteristics distinguish this lesion from other more common neoplastic, inflammatory rectal lesions that are typically isointense on T1-weighted imaging and enhance variably after gadolinium injection.

[MRI: overview, technique, interpretation].

The purpose of this paper is to describe the general principle of MRI, emphasising the practical conduct of the examination which consists of three main phases. The authors define the concepts of relaxation time and T1 and T2, essential parameters for the understanding of MRI. They simply explain how to recognise a predominance of T1- or T2-weighting on MRI images.

[Pelvic lymph node groups in computed tomography. Topographic atlas].

This atlas was prepared to facilitate the diagnosis of lymph mode enlargement in the pelvic region and to improve topographic diagnosis. Fifty computed tomographies were performed after lymphography using centimetric pelvic slices in order to select eight levels for reference. A statistical analysis was conducted to establish a diagram of the mean number of lymph nodes on the right and left side for each level.