Converting an FRT-Tagged Gene into a Fluorescent Protein Gene Fusion by Flp-Mediated Site-Specific Recombination

This protocol uses conditional plasmids carrying the open reading frame (orf) of either superfolder green fluorescent protein (sfGFP) or monomeric Cherry (mCherry) fused to a flippase (Flp) recognition target (FRT) site. In cells expressing the Flp enzyme, site-specific recombination between the plasmid-borne FRT and an FRT "scar" in a target gene in the bacterial chromosome results in chromosomal integration of the plasmid with the concomitant in-frame fusion of the target gene to the fluorescent protein orf. This event can be positively selected using an antibiotic-resistance marker (kan or cat) present on the plasmid. This method is slightly more laborious than generating the fusion directly by recombineering and has the limitation that the selectable marker is no longer removable. However, it has the advantage that it can be more readily integrated in mutational studies, allowing conversion of in-frame deletions resulting from Flp-mediated excision of a drug-resistance cassette (e.g., all those of the "Keio collection") into fluorescent protein fusions. Furthermore, in studies that require that the amino-terminal moiety of the hybrid protein keeps its biological activity, presence of the FRT "linker" sequence at the fusion junction makes it less likely for the fluorescent domain to sterically interfere with the folding of the amino-terminal domain.

NusG prevents transcriptional invasion of H-NS-silenced genes

Evolutionarily conserved NusG protein enhances bacterial RNA polymerase processivity but can also promote transcription termination by binding to, and stimulating the activity of, Rho factor. Rho terminates transcription upon anchoring to cytidine-rich motifs, the so-called Rho utilization sites (Rut) in nascent RNA. Both NusG and Rho have been implicated in the silencing of horizontally-acquired A/T-rich DNA by nucleoid structuring protein H-NS. However, the relative roles of the two proteins in H-NS-mediated gene silencing remain incompletely defined. In the present study, a Salmonella strain carrying the nusG gene under the control of an arabinose-inducible repressor was used to assess the genome-wide response to NusG depletion. Results from two complementary approaches, i) screening lacZ protein fusions generated by random transposition and ii) transcriptomic analysis, converged to show that loss of NusG causes massive upregulation of Salmonella pathogenicity islands (SPIs) and other H-NS-silenced loci. A similar, although not identical, SPI-upregulated profile was observed in a strain with a mutation in the rho gene, Rho K130Q. Surprisingly, Rho mutation Y80C, which affects Rho's primary RNA binding domain, had either no effect or made H-NS-mediated silencing of SPIs even tighter. Thus, while corroborating the notion that bound H-NS can trigger Rho-dependent transcription termination in vivo, these data suggest that H-NS-elicited termination occurs entirely through a NusG-dependent pathway and is less dependent on Rut site binding by Rho. We provide evidence that through Rho recruitment, and possibly through other still unidentified mechanisms, NusG prevents pervasive transcripts from elongating into H-NS-silenced regions. Failure to perform this function causes the feedforward activation of the entire Salmonella virulence program. These findings provide further insight into NusG/Rho contribution in H-NS-mediated gene silencing and underscore the importance of this contribution for the proper functioning of a global regulatory response in growing bacteria. The complete set of transcriptomic data is freely available for viewing through a user-friendly genome browser interface.

Education and information needs identified by patients and key family members prior to surgery for a skull base neoplasm: implications for practice

Many patients with extensive skull base neoplasms poorly understand the nature of their problems. Therefore, education of patients and family members is an important component of care. Research has established the benefits of pre-operative education for other types of surgery and information seeking as an important method of coping. Yet in 184 references on skull base surgery (1996-1999), no case-based or research data that examined education and information needs prior to hospitalization for surgery was found. The investigators present findings from Phase 1 of a descriptive research study designed to determine the education and information needs perceived by patients and family members at their initial visit to the neurosurgeon and on admission to hospital. Data was collected, using interviews and a questionnaire, from 18 patients with skull base neoplasms and 15 key family members. The study findings provide insight into the experience of patients and families during a time period (prehospitalization) that has not been explored. Results indicate that key education needs of participants are related to the brain tumour and surgery. Findings reveal patient participants in contrast to family members had little in the way of information needs. Underlying and impacting the education and information needs is the theme of 'Hearing the News'. Relevance of the results to nursing practice in the pre-operative phase is addressed.

Nursing concerns associated with radical skull base surgery: a case study

Historically, surgical management of extensive neoplasms of the cranial base has been limited by anatomical boundaries. However, major theoretical and technological advances now permit radical surgical resections. The perioperative nursing care of these patients is challenging and requires a wealth of knowledge and skills. The complexity of caring for patients undergoing radical skull base surgery is highlighted through a case study.

[The Guidance Center. Evaluation after a year of activity]

The C.H.U. of Grenoble started a child Guidance Clinic for assuming the education of handicapped children from 2 to 6 (years of age). A whole organization for medical advice, training for walk, psychotherapy, orthophony, together with a day hospital can be found there--the working of whith is provided by a pluridisciplinary team of 15 members (among whom educators, psychanalistes, psychiatristes, psychologistes, pediatristes). The parents may profit by interviews with the educators, with a conjugal adviser, or by parents groups who meet twice a month. An average of 25 children are registered, and 15 are present, among whom most are trisomic 21, or psychotics. The day price is 257 F and 100% returned by the social Security. At last, besides the therapeutic function, the clinic also plays a pedagogic part by receiving probationers coming from different places.