The preparation, properties and application of carbon fibers for SPME.

The conditions of preparation of new types of carbon fibers for solid phase micro extraction (SPME) prepared by methylene chloride pyrolysis (at 600 degrees C) on the quartz fiber (100 microm) as well as by supporting synthetic active carbon (prepared especially for this purposes) supported in a special epoxide-acrylic polymer is described. The properties of such carbon fibers for SPME were defined by determination of the partition coefficient of the tested substances (i.e., benzene, toluene, xylenes, trichloromethane and tetrachloromethane) and by the microscopic investigations with the application of the optical and scanning electron microscope. The obtained carbon SPME fibers were applied to the analysis of some volatile organic compounds from its aqueous matrix. During chromatographic GC test, at the investigated SPME carbon fibers, we obtained different but mostly high partition coefficients for the determined compounds (Kfs from 120 for trichloromethane up to 11,500 for tetrachloromethane). Owing to the high partition coefficients of the studied substances obtained on carbon fibers, it was possible to do the analysis of organic substances occurring in trace amounts in different matrices. In this paper, we present the analysis of BTX contents in the petrol analyzed with the application carbonized with CH(2)Cl(2) SPME fiber (C1NM) and a headspace over the petrol sample (concentration of each BTX approximately g/dm(3)).

Gatifloxacin 200 mg or 400 mg once daily is as effective as ciprofloxacin 500 mg twice daily for the treatment of patients with acute pyelonephritis or complicated urinary tract infections.

The efficacy and safety of two oral dosing regimens of gatifloxacin were compared to ciprofloxacin in the treatment of complicated urinary tract infection in a randomised, double-blind multi-centre trial. One thousand one hundred and twenty-three adult patients with complicated urinary tract infection (70%) or pyelonephritis (30%) were initially enrolled, 1122 were treated. Of these, 824 were included in a modified ITT population: gatifloxacin 200 mg (274 patients) or 400 mg (280 patients) once daily or ciprofloxacin 500 mg twice daily for 5-14 days (269 patients). Bacteriological and clinical responses were assessed 7-9 days after the end of treatment (EOT) and 4-6 weeks post-treatment (end of study visit, EOS). The bacteriological response rates per patient at EOT in the gatifloxacin 400 mg, gatifloxacin 200 mg and ciprofloxacin groups were 77% (207/269), 78% (208/268) and 73% (190/259), respectively. At EOS they were slightly lower: 70% (184/262), 71% (176/248) and 69% (174/252), respectively. The clinical responses at EOT were 69% (190/277), 70% (190/273) and 65% (174/266). At EOS they were 71% (193/273), 70% (182/259) and 74% (190/258). The overall eradication rates of initial pathogens at EOT and EOS were 85.3% and 88.4% in the gatifloxacin 400 mg group; 84.1 and 90.1% in the gatifloxacin 200 mg group and 85.1 and 91.4% in the ciprofloxacin group. Both oral regimens of gatifloxacin were as effective as that of ciprofloxacin. All treatment groups showed a similar safety profile, nausea being the most frequently reported adverse event.

Regulated expression of the MRP8 and MRP14 genes in human promyelocyticleukemic HL-60 cells treated with the differentiation-inducing agents mycophenolic acid and 1 alpha,25-dihydroxyvitamin D3.

The calcium-binding proteins MRP8 and MRP14 present in mature monomyelocytic cells are induced during differentiation and may mediate the growth arrest in differentiating HL-60 cells. We determined the levels of a protein complex (PC) containing MRP8 and MRP14 and investigated the mechanism by which the genes encoding these proteins are regulated in HL-60 cells treated with the differentiation-inducing agent mycophenolic acid (MPA). While the PC was barely detectable in untreated cells, MPA treatment resulted in elevated levels of the PC which were maximal at 3-4 days and were found to directly parallel gains in the steady-state levels of MRP8 and MRP14 mRNA. Transcription studies with the use of nuclear run-on experiments revealed increased transcription initiation at the MRP8 and MRP14 promoters after MPA treatment. 1 alpha,25-Dihydroxyvitamin D3, which induces HL-60 cell differentiation by another mechanism, was also found to increase transcription initiation at the MRP8 and MRP14 promoters. Our results suggest that this initiation is the major control of maturation agent-mediated increases in MRP8 and MRP14 gene expression, and supports a role for the PC in terminal differentiation of human monomyelocytic cells.

Characterization of stress-responsive behavior in Pseudomonas aeruginosa PAO: isolation of Tn3-lacZYA fusions with novel damage-inducible (din) promoters.

Although the pervasive soil and water microorganism Pseudomonas aeruginosa demonstrates heightened sensitivity to UV radiation, this species possesses a recA gene that, based on structural and functional properties, could mediate a DNA damage-responsive regulon similar to the SOS regulon of Escherichia coli. To determine whether P. aeruginosa encodes such stress-inducible genes, the response of P. aeruginosa to DNA-damaging agents including far-UV radiation (UVC) and the quinolone antimicrobial agent norfloxacin was investigated by monitoring the expression of fusions linking P. aeruginosa promoters to a beta-galactosidase reporter gene. These fusions were obtained by Tn3-HoHoI insertional mutagenesis of a P. aeruginosa genomic library. Eight different damage-inducible (din) gene fusions were isolated which lack homology to the P. aeruginosa recA gene. Expression of the three gene fusions studied, dinA::lacZYA, dinB::lacZYA, and dinC::lacZYA, increased following UVC and quinolone exposure but not following heat shock. Similar to E. coli SOS genes, the din genes were induced to different extents and with dissimilar kinetics following UVC irradiation.