|
|
|
|
|
|
Identification of  B-Dependent
Genes in Bacillus cereus by Proteome and In Vitro Transcription Analysis.Willem van Schaik, 2004.The alternative sigma factor B
of the food pathogen Bacillus cereus is activated upon stress
exposure and plays a role in the adaptive response of vegetative
cells . This study describes the identification of
B-dependent
genes in B . cereus . Two-dimensional gel electrophoresis was
performed with protein extracts from a
B-overproducing
B . cereus strain . Nine protein spots, which were absent from
the negative control, were identified by matrix-assisted laser
desorption ionization-time of flight mass spectrometry or N-terminal
sequencing . The
B-dependent
expression of the corresponding genes was confirmed by Northern blot
analysis with RNA isolated from B . cereus ATCC 14579 and its
sigB null mutant . Northern blot analysis also revealed that
six other genes were part of
B-dependent
operons . The proteins that are predicted to be encoded by the
B-dependent
genes include an intracellular protease, a Mg2+
transporter, and a thiamine biosynthesis protein (ThiG) . Highly
conserved promoter sites were found to precede all
B-dependent
genes, with the exception of thiG . By searching the B .
cereus genome for this conserved promoter sequence, five more
candidate
B-dependent
genes were identified . Northern blot analysis and in vitro
transcription experiments with a reconstituted B . cereus
B-RNA
polymerase holoenzyme confirmed the
B
dependency of two of these genes and strongly suggested that two
other genes, encoding an oligopeptide-binding OppA-like protein and
subunit II of the cytochrome d ubiquinol oxidase, are also
B
dependent . In conclusion,
B
of B . cereus not only regulates genes directly involved in the
stress response but may also control specific metabolic
rearrangements .
Intrapulmonary Pharmacokinetics and Pharmacodynamics of Itraconazole and 14-Hydroxyitraconazole at Steady State. John E. Conte Jr., 2004.We determined the steady-state intrapulmonary pharmacokinetic and pharmacodynamic parameters of orally administered itraconazole (ITRA), 200 mg every 12 h (twice a day [b.i.d.]), on an empty stomach, for a total of 10 doses, in 26 healthy volunteers . Five subgroups each underwent standardized bronchoscopy and bronchoalveolar lavage (BAL) at 4, 8, 12, 16, and 24 h after administration of the last dose . ITRA and its main metabolite, 14-hydroxyitraconazole (OH-IT), were measured in plasma, BAL fluid, and alveolar cells (AC) using high-pressure liquid chromatography . Half-life and area under the concentration-time curves (AUC) in plasma, epithelial lining fluid (ELF), and AC were derived using noncompartmental analysis . ITRA and OH-IT maximum concentrations of drug (Cmax) (mean ± standard deviation) in plasma, ELF, and AC were 2.1 ± 0.8 and 3.3 ± 1.0, 0.5 ± 0.7 and 1.0 ± 0.9, and 5.5 ± 2.9 and 6.6 ± 3.1 µg/ml, respectively . The ITRA and OH-IT AUC for plasma, ELF, and AC were 34.4 and 60.2, 7.4 and 18.9, and 101 and 134 µg · hr/ml . The ratio of the Cmax and the MIC at which 90% of the isolates were inhibited (MIC90), the AUC/MIC90 ratio, and the percent dosing interval above MIC90 for ITRA and OH-IT concentrations in AC were 1.1 and 3.2, 51 and 67, and 100 and 100%, respectively . Plasma, ELF, and AC concentrations of ITRA and OH-IT declined monoexponentially with half-lives of 23.1 and 37.2, 33.2 and 48.3, and 15.7 and 45.6 h, respectively . An oral dosing regimen of ITRA at 200 mg b.i.d . results in concentrations of ITRA and OH-ITRA in AC that are significantly greater than those in plasma or ELF and intrapulmonary pharmacodynamics that are favorable for the treatment of fungal respiratory infection . Environmental Surveillance System To Track Wild Poliovirus Transmission. Jagadish M. Deshpande, 2003.Eradication of poliomyelitis from large metropolis cities in India has been difficult due to high population density and the presence of large urban slums . Three paralytic poliomyelitis cases were reported in Mumbai, India, in 1999 and 2000 in spite of high immunization coverage and good-quality supplementary immunization activities . We therefore established a systematic environmental surveillance study by weekly screening of sewage samples from three high-risk slum areas to detect the silent transmission of wild poliovirus . In 2001, from among the 137 sewage samples tested, wild poliovirus type 1 was isolated from 35 and wild poliovirus type 3 was isolated from 1 . Acute flaccid paralysis (AFP) surveillance indicated one case of paralytic poliomyelitis from the city . Phylogenetic analysis with complete VP1 sequences revealed that the isolates from environmental samples belonged to four lineages of wild polioviruses recently isolated from poliomyelitis cases in Uttar Pradesh and not to those previously isolated from AFP cases in Mumbai . Wild poliovirus thus introduced caused one case of paralytic poliomyelitis . The virus was detected in environmental samples 3 months before . It was found that wild polioviruses introduced several times during the year circulated in Mumbai for a limited period before being eliminated . Environmental surveillance was found to be sensitive for the detection of wild poliovirus silent transmission . Nucleotide sequence analysis helped identify wild poliovirus reservoir areas .
|
© 2005
Transgalactic Ltd (manufacturer of Bioscreen C software) |
Privacy Statement | P.O. Box
1393, 00101 Helsinki, Finland,
Last modified: May 25, 2005
| ||||||
