[Targeting anticoagulated patients for medication reconciliation at discharge in orthopaedic surgery]. / Conciliation médicamenteuse de sortie ciblée en chirurgie orthopédique : focus sur les anticoagulants.

In orthopedic surgery, the well-known iatrogenic risk of oral anticoagulants is particularly increased due to surgical management (suspension and resumption of treatment). In order to prevent avoidable iatrogenic events linked to incomplete discharge documents, targeted medical reconciliation (MR) has been deployed. This is a single-center prospective study conducted in orthopaedic surgery for six months including any patient treated upon admission with an oral anticoagulant. The analysis of the compliance of discharge documents (hospitalization report and prescriptions) was carried out before and after pharmaceutical interventions. The criteria analysed included the mention of the oral treatment, its dosage as well as the supervision of the switch from heparin therapy to the usual oral treatment. The documents were compliant if the mention of oral anticoagulant treatment and the date of the shift were correctly documented. Thirty-seven patients were included. The compliance rate of discharge documents was significantly improved by MR, going from 13.5 % to 78.4 % (P <0.05). The non-compliances before the intervention concerned the absence of mention of: the usual treatment (64.9 %), its dosage (81.1 %) or the switch's securing (75.7 %). Discharge from surgery of the patient on anticoagulants is a stage presenting a real risk which can be managed by the intervention of pharmacists. Improving the compliance of discharge documents is a first step towards better securing drug management.

Identification of the binding site of the {sigma}54 hetero-oligomeric FleQ/FleT activator in the flagellar promoters of Rhodobacter sphaeroides.

Expression of the flagellar genes in Rhodobacter sphaeroides is dependent on one of the four sigma-54 factors present in this bacterium and on the enhancer binding proteins (EBPs) FleQ and FleT. These proteins, in contrast to other well-characterized EBPs, carry out activation as a hetero-oligomeric complex. To further characterize the molecular properties of this complex we mapped the binding sites or upstream activation sequences (UASs) of six different flagellar promoters. In most cases the UASs were identified at approximately 100 bp upstream from the promoter. However, the activity of the divergent promoters flhAp-flgAp, which are separated by only 53 bp, is mainly dependent on a UAS located approximately 200 bp downstream from each promoter. Interestingly, a significant amount of activation mediated by the upstream or contralateral UAS was also detected, suggesting that the architecture of this region is important for the correct regulation of these promoters. Sequence analysis of the regions carrying the potential FleQ/FleT binding sites revealed a conserved motif. In vivo footprinting experiments with the motAp promoter allowed us to identify a protected region that overlaps with this motif. These results allow us to propose a consensus sequence that represents the binding site of the FleQ/FleT activating complex.

The N terminus of FliM is essential to promote flagellar rotation in Rhodobacter sphaeroides.

FliM is part of the flagellar switch complex. Interaction of this protein with phospho-CheY (CheY-P) through its N terminus constitutes the main information relay point between the chemotactic system and the flagellum. In this work, we evaluated the role of the N terminus of FliM in the swimming behavior of Rhodobacter sphaeroides. Strains expressing the FliM protein with substitutions in residues previously reported in Escherichia coli as being important for interaction with CheY showed an increased stop frequency compared with wild-type cells. In accordance, we observed that R. sphaeroides cells expressing FliM lacking either the first 13 or 20 amino acids from the N terminus showed a stopped phenotype. We show evidence that FliMDelta13 and FliMDelta20 are stable proteins and that cells expressing them allow flagellin export at levels indistinguishable from those detected for the wild-type strain. These results suggest that the N-terminal region of FliM is required to promote swimming in this bacterium. The role of CheY in controlling flagellar rotation in this organism is discussed.

sigma(54) Promoters control expression of genes encoding the hook and basal body complex in Rhodobacter sphaeroides.

Gene expression of the flagellar system is tightly controlled by external stimuli or intracellular signals. A general picture of this regulation has been obtained from studies of Salmonella enterica serovar Typhimurium. However, these regulatory mechanisms do not apply to all bacterial groups. In this study, we have investigated regulation of the flagellar genetic system in Rhodobacter sphaeroides. Deletion analysis, site-directed mutagenesis, and 5'-end mapping were conducted in order to identify the fliO promoter. Our results indicate that this promoter is recognized by the factor sigma(54). Additionally, 5'-end mapping of the flgB and fliK transcripts suggests that these mRNAs are also transcribed from sigma(54) promoters. Finally, we showed evidence that suggests that fliC transcription is not entirely dependent on the presence of a complete basal body-hook structure. Our results are discussed in the context of a possible regulatory hierarchy controlling flagellar gene expression in R. sphaeroides.

Transcriptional repression of gdhA in Escherichia coli is mediated by the Nac protein.

In this work we show that the nac gene from Escherichia coli is transcriptionally active, and that its expression is dependent on NRI (NtrC) and sigma-54. Northern blot experiments show a monocistronic nac-specific mRNA that is detected when wild-type cells are grown in nitrogen-limiting conditions. Our data also show that in nitrogen-limiting conditions Nac is involved in the transcriptional repression of the gdhA gene (encoding glutamate dehydrogenase) except when L-glutamine is used as the only nitrogen source. Moreover, the high level of GDH activity observed in a nac mutant strain is reduced when a wild-type nac gene is introduced under control of the lac promoter in N-limiting conditions, but not in L-glutamine or N-excess. These results suggest the existence of an additional mechanism responsible for overcoming repression by Nac.

The flagellar switch genes fliM and fliN of Rhodobacter sphaeroides are contained in a large flagellar gene cluster.

In this work, the genes that encode the FliM and FliN proteins of Rhodobacter sphaeroides were characterized. These genes are part of a large flagellar gene cluster in which six additional open reading frames encoding products homologous to FliL, FliO, FliP, FliQ, FliR, and FlhB proteins from other bacteria were identified. The inactivation of the fliM gene gave a nonflagellate phenotype (Fla-), suggesting that FliM is required for flagellar assembly. Complementation analysis of this fliM mutant indicated that fliM and fliN transcription starts beyond the 5' end of fliK and terminates after fliN.

An IS4 insertion at the glnA control region of Escherichia coli creates a new promoter by providing the -35 region of its 3'-end.

An insertion element (IS)4 insertion selected as suppressor of the rpoN73::Tn5 alelle was located inside the control region of the glnA gene in Escherichia coli. In the rpoN73::Tn5 background the IS4 insertion promotes glnA transcription at a low constitutive level sufficient to sustain glutamine-independent growth. The IS4 insertion mutation in either rpoN73::Tn5 or wild-type backgrounds promotes glnA transcription from a new start site located two bases downstream of the glnAp2 start site. Analysis of sequences flanking the insertion point showed a promoter sequence whose -35 region was located inside the IS4 sequence and the -10 region was inside the glnA control region. Site-directed mutagenesis of relevant nucleotide residues of the newly created promoter impaired transcription of a reporter gene. The results support our contention that IS4 carries a -35 promoter region that is able to create functional hybrid promoters. We propose that this mechanism could be one of the molecular reasons of the suppressor activity previously reported for IS4.