[Management of the Legionella-link risk in a multicentre area's hospital: lessons learned of a six-year experience]. / Gestion des risques liés aux légionelles dans un centre hospitalier multisites : retour d'expérience de plus de six années.

To reduce the Legionella-linked risk in the several sites of Sud-Francilien Hospital, following a hospital-acquired legionellosis case, a multidisciplinary working group performed an action plan monitored through Legionella pneumophila counts in hot water supply. From 2003 to the first half year 2009, positive points for Legionella pneumophila in the main sites of the hospital decreased from 85.71 to 28.00%, representing a significant reduction of 67.33%. Similar results were observed for three of the four establishments, whereas the last did not describe a pronounced reduction of Legionella pneumophila counts and showed constantly serogroup 1 strains. During this period, investigations of additional cases of legionellosis demonstrated a nosocomial transmission in one case in this last site. Multidisciplinary mobilization in management of Legionella-linked risk contributed to these results.

Evaluation of the quality of hospital food from the kitchen to the patient.

Food-borne pathogens can multiply if food is not maintained at an appropriate temperature and if there are delays between food preparation and distribution. The aim of this study was to evaluate the quality of meals during transport from the kitchens to the patients in three departments of a university hospital. Meals were transported inside insulated, cooled food carts. We analysed the delays at each step of the transport process, and measured the temperature inside the food cart and inside the meals. The total duration of the transport (mean=85.3 min; range 44-123 min) conformed to the official recommendations (<2 h at a temperature <10 degrees C before consumption). The internal temperature of 73.6% of the 30 food carts followed was below 10 degrees C. The internal temperature of the meals was below 10 degrees C in 91.7% of cases when the food cart was first opened, but in only 12% of cases by the time the last patient was served. No pathogens were isolated from any of the samples. However, 10% of meals, all of which were salads, had total viable counts of bacteria above the recommended limits. This study confirms that it is essential to control time and temperature to ensure food quality and safety in hospitals.

Strategies for the diagnosis and treatment of bacteraemia in children with central venous catheters: an analysis.

The aim of this study was to analyse the diagnostic, empirical and therapeutic strategies adopted when a blood culture from a hospitalized child with a central venous catheter is 'positive', and to assess whether practices complied with the consensus adopted in our hospital, inspired by published recommendations. One hundred and ten cases of bacteraemia were studied prospectively. Investigations to determine whether the catheter was the cause of infection were carried out in 45% of cases, and the catheter was removed as recommended in 39% of cases. Of the patients that received empirical treatment, 56% received broad-spectrum antibiotics with no apparent clinical justification. Following susceptibility testing on the isolated strain, the antibiotic treatment was considered to be appropriate in 58% of cases. Overall, compliance with the consensus recommendations was poor. This was partly due to the high turnover rate of antibiotic prescribers.

Long chain arginine esters: a new class of cationic detergents for preparation of hydrophobic ion-paired complexes.

The ability of stoichiometric amounts (based on charged groups) of ionic detergents to bind to oppositely charged ionic compounds has been recently reviewed. These hydrophobic ion-paired (HIP) complexes display altered solubility properties. Most of the work to date on HIP compelxes has focused on basic drugs and anionic detergents. It would be extremely useful to extend this approach to acidic compounds, including DNA and RNA. However, most cationic detergents are relatively toxic. It is hypothesized that detergents constructed from naturally occurring or well tolerated components, coupled by labile linkages, will be less toxic and still able to form strong HIP complexes. This study describes the synthesis and characterization of long chain alkyl esters of arginine. This class of cationic detergents, which have not been reported previously, are less cytotoxic than alkyltrimethylammonium detergents, possibly making them more acceptable in drug delivery applications. These arginine esters exhibit detergent-like properties. For example, the dodecyl ester of arginine has a critical micelle concentration of 0.07 mM, while being approximately 5-10 fold less toxic than tetradecyltrimethylammonium bromide. The arginine dodecyl ester forms stable HIP complexes with plasmid DNA. The complex is sufficiently stable to allow some modest level of transfection with Cos-7 cells in a time- and concentration-dependent fashion. This work demonstrates that arginine-based cationic detergents are effective ion-pairing agents, appear to be less toxic than alkyltrimethylammonium compounds, and form stable complexes with DNA.

Formation of an active dimer during storage of interleukin-1 receptor antagonist in aqueous solution.

The degradation products of recombinant human interleukin-1 receptor antagonist (rhIL-1ra) formed during storage at 30 degrees C in aqueous solution were characterized. Cationic exchange chromatography of the stored sample showed two major, new peaks eluting before (P1) and after (L2) the native protein, which were interconvertible. Size-exclusion chromatography and electrophoresis documented that both the P1 and L2 fractions were irreversible dimers, formed by noncovalent interactions. A competition assay with interleukin-1 indicated that on a per monomer basis the P1 and L2 dimers retained about two-thirds of the activity of the native monomer. Infrared and far-UV circular dichroism spectroscopies showed that only minor alterations in secondary structure arose upon the formation of the P1 dimer. However, alteration in the near-UV circular dichroism spectrum suggested the presence of disulfide bonds in the P1 dimer, which are absent in the native protein. Mass spectroscopy and tryptic mapping, before and after carboxymethylation, demonstrated that the P1 dimer contained an intramolecular disulfide bond between Cys-66 and Cys-69. Although conversion of native protein to the P1 dimer was irreversible in buffer alone, the native monomer could be regained by denaturing the P1 dimer with guanidine hydrochloride and renaturing it by dialysis, suggesting that the intramolecular disulfide bond does not interfere with refolding. Analysis of the time course of P1 formation during storage at 30 degrees C indicated that the process followed first-order, and not second-order, kinetics, suggesting that the rate-limiting step was not dimerization. It is proposed that a conformational change in the monomer is the rate-limiting step in the formation of the P1 dimer degradation product. Sucrose stabilized the native monomer against this process. This result can be explained by the general stabilization mechanism for this additive, which is due to its preferential exclusion from the protein surface.

Physical factors affecting the storage stability of freeze-dried interleukin-1 receptor antagonist: glass transition and protein conformation.

The effects of glass transition of, and protein conformation in, the dried solid on the storage stability of freeze-dried recombinant human interleukin-1 receptor antagonist (rhIL-1ra) were examined. Glass transition is a temperature-dependent phenomenon. Amorphous materials become hard and brittle at temperatures below their characteristic glass transition temperatures (Tg) such that diffusion of molecules along the matrix is not sufficient to cause large-scale structural changes. To ascertain the importance of the glass transition in protein storage stability, we compared 10 different lyophilized rhIL-1ra formulations, with Tgs ranging from 20 to 56 degrees C, during several weeks of storage at temperatures above and below the samples' Tgs. Protein degradation, both deamidation and aggregation, was greatly accelerated at temperatures above Tg, but for some formulations also arose below Tg. Thus, storage of dried proteins below the Tg is necessary but not sufficient to ensure long-term stability. To examine the effects of protein structure in the dried solid, we prepared formulations with various sucrose concentrations, all of which had a Tg = 66 +/- 2.5 degrees C. With infrared spectroscopy, we determined that the protein lyophilized with /=5% sucrose, conformational change was inhibited during lyophilization. When stored at 50 degrees C, degradation of the freeze-dried protein varied inversely with sucrose concentration. These results indicate that structural changes arising during the lyophilization process led to damage during subsequent storage, even if the storage temperature was less than the Tg. Together the results of these studies document that to obtain optimum stability of dried rhIL-1ra it was necessary to inhibit conformational change during lyophilization and to store at temperatures below the Tg of the dried formulation.

The use of intensive clinic support to permit outpatient autologous bone marrow transplantation for breast cancer.

Recent studies have explored feasibility and cost considerations of administering high-dose chemotherapy with hematopoietic support in the outpatient setting. Between October 1991 and April 1993, we studied 110 women with primary metastatic breast cancer undergoing high-dose chemotherapy with hematopoietic support. Ninety-two patients were managed in an outpatient clinic after high-dose chemotherapy and autologous bone marrow transplantation and peripheral blood progenitor cells. The remaining 18 patients received the same high-dose treatment and hematopoietic support in the hospital and were discharged to a nearby hotel each night; these patients were the pilot group for this effort and also served as a control group. High-dose chemotherapy consisted of cyclophosphamide/cisplatin/carmustine. Chemotherapy was well tolerated, allowing 95% of 65 eligible patients enrolled since November 1992 to be discharged soon after chemotherapy for outpatient posttransplant support. Approximately 70% of these patients required either no hospital readmission or brief readmissions of 1 to 4 days. Median days of hospitalization required for historical groups of patients receiving high-dose chemotherapy plus bone marrow support as inpatient therapy, high-dose chemotherapy with colony-stimulating factor-primed peripheral blood progenitor cells and autologous bone marrow transplantation as inpatient therapy in a traditional transplant model, and outpatient management of autologous bone marrow transplantation patients were 37, 24.5, and 7 days, respectively, despite the same high-dose chemotherapy. Charges related to the transplant procedure were reduced by 50% over the last 2 to 5 years using the outpatient management approach. This procedure may be applicable to patients with other forms of cancer receiving intensive chemotherapeutic regimens. The use of outpatient management in a transplant setting is highly cost effective.