[Results transferability on RXL, ARX, X-Pand, BN2 (Dade Behring) and modular DP (Roche Diagnostics) analysers: application to component assays of fibrotest and Actitest]. / Transférabilité des résultats entre les automates RXL, ARX, X-Pand, BN2 (Dade Behring) et le Modular DP (Roche Diagnostics): application aux paramètres des Fibrotest et Actitest.

The follow up of patients with chronic liver diseases and the data from multicentric clinical studies are affected by the variability of assay results for the same parameter between the different laboratories. Today, the main objective in clinical chemistry throughout the world is to harmonise the assay results between the laboratories after the confirmation of their traceability, in relation to defined reference systems. In this context, the purpose of our study was to verify the homogeneity of haptoglobin, apolipoprotein A1, total bilirubin, GGT activity, ALAT activity results, which are combined in Fibrotest and Actitest, between Dimension Analysers RXL, ARX and X-PAND (Dade Behring Society). Moreover, we verified the transferability of Fibrotest and Actitest results between the RXL, and either the BN2 (haptoglobin and apolipoprotein A1) or the Modular DP (total bilirubin, GGT and ALAT activity concentrations). The serum samples from 150 hospitalised patients were analysed on the different analysers. Specific protein assays were calibrated using solutions standardised against reference material on Dimension and BN2 analysers. Total bilirubin assays were performed by a diazoreaction on Dimension and Modular DP analysers. The GGT and ALAT activity measurements on the Dimension analysers were performed in accordance with the reference methods defined by the International Federation of Clinical Chemisty and Laboratory Medicine (IFCC). On the Modular, enzyme activity measurements were performed according to the Szasz method (L-gamma- glutamyl-4-nitroanilide as substrate) modified by Persijn and van der Slik (L-gamma- glutamyl-3-carboxy- 4-nitroanilide as substrat) for GGT and according to the IFCC specifications for ALAT. The methods of enzymatic activity measurement were calibrated on the Modular only. Liver fibrosis and necroinflammatory activity indices were determined using calculation algorithms, after having adjusted each component's result of Fibrotest and Actitest for gender and age. Our study has shown, for each parameter, harmonious results between the Dimension analysers and between RXL and BN2- Modular DP. Disregarding alpha-2 macroglobulin which cannot be assayed on RXL, the results of Fibrotest and Actitest were similar as performed on BN2- Modular DP and RXL.

[Antibiotic sensitivity of bacteria isolated from pathological specimens and utilization of beta-lactams in an orthopedic surgery service]. / Sensibilité aux antibiotiques des bactéries isolées de produits pathologiques et consommation de bêtalactamines dans un service de chirurgie osseuse.

From 1980 to 1984, computerized data on the sensitivity to the main antibiotics of 1991 strains isolated from clinical specimens were evaluated in relation to beta-lactam use and hospital activity in a unit of orthopedic surgery. No major variations were found in distribution of species throughout the study period, whereas sensitivity to antimicrobial agents changed. From 1980 to 1982, patients had postoperative prophylactic treatment with cephalosporin (cefazolin) for two days; during the same period, 59% of 557 Gram negative organisms were resistant to cefazolin and 31% of Staphylococci were resistant to methicillin (and to other antibiotics). In 1983 and 1984, cefazolin was replaced by intraoperative flash therapy with a penicillin-M (cloxacillin); concomitantly, sensitivity to cefazolin increased among Gram negative organisms (38% of 485 isolates were cefazolin-resistant; p less than 0.001) and Staphylococci (16% of 342 isolates were methicillin-resistant; p less than 0.001). Phage typing of S. aureus failed to disclose any epidemic outbreak. Since hospital activity remained the same throughout the period under study, it seems justified to correlate the increase in bacterial sensitivity observed to the decrease in use of cephalosporin, although other factors (microepidemic, isolation techniques) may be involved.

[Bacterial contamination of the air in different operating rooms]. / Contamination bactérienne de l'air dans différentes salles d'opération.

Bacteria air samples were taken in the operating rooms, with no people present, to specify the level of air contamination and suggest bacteriological standards for different operating rooms. In the first step of this study, for 5 months the air contamination mean value of operating rooms, ventilated at 15 changes/hour was 18.5 Cfu/m3 +/- 1.9. In the second part of the study, during two years, 1 381 air samples were taken in 8 different operating rooms. The mean values of air contamination range from 1.4 Cfu/m3 in a Charnley isolator system to 121 Cfu/m3 in an operating room ventilated at 7.5 changes per hour. As a general rule, the airborne contamination is more significant in the oldest operating rooms than in the new one with filtrated air. The variations observed between 1981 and 1982 are explained by technical modifications of the system or progress in control of operating room conditions. Measurements of the bacterial contamination of the air give useful informations, but it is however better to ensure that the specifications for volume air supply and positive air pressure in the operating theatres are being fulfilled. The airborne bacterial concentration in a modern ventilated operating room should not exceed 30 Cfu/m3.