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L Ballester

Publications and source records attributed to L Ballester.

22 records · Page 2Linked to original sources

Determination of cyclohexamone after derivatization with 2,4-dinitrophenyl hydrazine in intravenous solutions stored in PVC bags by high performance liquid chromatography.

A high performance liquid chromatographic procedure is described for the determination of cyclohexanone leached in intravenous solutions from the poly(vinyl chloride) bags. After derivatization with 2,4-dinitrophenylhydrazine and extraction with pentane, the cyclohexanone derivative was analysed on a C18 BDS Hypersil column using mobile phase mixture of acetonitrile:water (55:45). Ultra-violet detection was performed at 368 nm. The limit of quantification was 30 ng/mL and the assay was linear from 0.05 to 50 micrograms/mL. The recovery was better than 95%. The proposed method is satisfactory in its accuracy and precision with particularly relative standard deviations (RSD) for intra-assay and inter-assay of below 10%. This method has been successfully used for the determination of cyclohexanone in aqueous solutions such as sodium chloride (0.9%) and glucose (5%) stored in PVC containers. The values obtained varied between 2.04 and 44.9 micrograms/mL according to solutions and volume.

Chromatography, High Pressure Liquid↗

In vitro effects of spiramycin and dirithromycin on IL1 beta production by human LPS-stimulated mononuclear cells.

Polymorphonuclear neutrophils are the predominant cells in acute inflammatory lesions and their functions and recruitment are regulated by cytokines, including IL1, TNF and IL8. Antibiotic modulation of inflammatory effects has stimulated investigations of antibiotics for their potential activity as immunomodulators over their primary bactericidal or bacteriostatic activities. This study reports the influence of macrolides, spiramycin and dirithromycin on IL1 beta production. Mononuclear cells, isolated from healthy human volunteers, were preincubated with macrolides (0.1 to 500 micrograms/ml) and stimulated by Escherichia coli lipopolysaccharide. Then, IL1 beta production was detected by western blotting analysis. At therapeutic concentrations, dirithromycin and spiramycin seemed to enhance IL1 beta production by LPS-stimulated cells, with +37 per cent and +28 per cent at 1 microgram/ml respectively. At supratherapeutic concentrations, these drugs seemed to inhibit IL1 beta production through protein kinase C inhibition, with inhibitory concentrations 50 per cent of 378 micrograms/ml for dirithromycin and 234 micrograms/ml for spiramycin. So, macrolides may modulate the host defence system through their influence on cytokine production.

Anti-Bacterial Agents↗