[Evaluation of the impact of different lengths of pre-enrichment in a nutritive broth and prolonged incubation of MRSA-ID, a chromogenic agar medium, on its performances for identifying methicillin-resistant Staphylococcus aureus in screening samples]. / Evaluation de l'influence des conditions de culture sur les performances du milieu gélosé sélectif MRSA-ID pour l'identification de Staphylococcus aureus résistant à la méticilline dans les prélèvements de dépistage.

MRSA-carrier screening is recommended to prevent MRSA dissemination in hospitals. Rapid and specific detection of MRSA in the laboratory is a key element in enabling control measures. Our objective was to evaluate the impact of different lengths of pre-incubation in a nutritive broth and prolonged incubation of MRSA-ID, a chromogenic agar medium, on its performances for identifying MRSA in screening samples. According to our results, short-length pre-enrichments only provided a weak increase of sensitivity as compared to the absence of pre-enrichment. On the contrary, the sensitivity increase provided by an overnight pre-enrichment was significant. The prolongation of incubation in the chromogenic agar medium (48 hours instead of 24 hours) did not provide any significant increase of sensitivity but was associated with a strong and significant loss of specificity. Therefore, it seems relevant to reject prolonged incubation of selective agar media and to make a choice between the absence of pre-enrichment (faster results) and an overnight pre-enrichment (higher sensitivity), according to local epidemiology and local practices implemented for prevention.

Talcage by medical thoracoscopy for primary spontaneous pneumothorax is more cost-effective than drainage: a randomised study.

Simple thoracoscopic talcage (TT) is a safe and effective treatment of primary spontaneous pneumothorax (PSP). However, its efficacy has not previously been estimated in comparison with standard conservative therapy (pleural drainage (PD)). In this prospective randomised comparison of two well-established procedures of treating PSP requiring at least a chest tube, cost-effectiveness, safety and pain control was evaluated in 108 patients with PSP (61 TT and 47 PD). Patients in both groups had comparable clinical characteristics. Drainage and hospitalisation duration were similar in TT and PD patients. There were no complications in either group. The immediate success rate was different: after prolonged drainage (>7 days), 10 out of 47 PD patients, but only 1 out of 61 TT patients required a TT as a second procedure. Total costs of hospitalisation including any treatment procedure were not significantly different between TT and PD patients. Pain, measured daily by visual analogue scales, was statistically higher during the first 3 days in TT patients but not in those patients receiving opiates. One month after leaving hospital, there was no significant difference in residual pain or full working ability: 20 out of 58 (34%) versus 10 out of 47 (21%) and 36 out of 61 (59%) versus 26 out of 39 (67%) in TT versus PD groups, respectively. After 5 yrs of follow-up, there had been only three out of 59 (5%) recurrences of pneumothorax after TT, but 16 out of 47 (34%) after conservative treatment by PD. Cost calculation favoured TT pleurodesis especially with regard to recurrences. In conclusion, thoracoscopic talc pleurodesis under local anaesthesia is superior to conservative treatment by chest tube drainage in cases of primary spontaneous pneumothorax that fail simple aspiration, provided there is efficient control of pain by opioids.

Is waking electroencephalographic activity a predictor of daytime sleepiness in sleep-related breathing disorders?

No data are available in the literature assessing the potential use of waking electroencephalographic (EEG) activity in the detection of excessive daytime sleepiness (EDS) in patients with sleep-related breathing disorders (SRBD). The aim of this study was to evaluate whether waking EEG spectral power reflects the level of EDS in SRBD patients. The study was performed in 48 patients in whom quantitative EEG analysis, including the alpha attenuation coefficient (AAC), was performed. Sleepiness was assessed by the Epworth Sleepiness Scale, the Stanford Sleepiness Scale, the Visual Analogue Scale and the maintenance of wakefulness test. Although AAC and EEG spectral power tended to vary throughout the day, none of these variations correlated with EDS measures. Waking EEG measures were not different between snorers and apnoeic patients. Compared to nonsleepy patients, sleepy patients had greater theta and slow alpha powers, but the differences did not reach statistical significance. The EEG slowing was independent of hypoxaemia, severity of SRBD, or degree of sleep disruption. The authors conclude that waking electroencephalographic measures are not sensitive enough to predict variation in alertness or to differentiate sleepy from nonsleepy sleep-related breathing disorders patients. The degree of electroencephalographic slowing was related neither to sleep disruption nor to severity of sleep-related breathing disorders.

Adult and paediatric size bronchoscopes for bronchoalveolar lavage in mechanically ventilated patients: yield and side effects.

BACKGROUND: Bronchoalveolar lavage is considered a safe procedure. When performed in the mechanically ventilated patient, however, potentially harmful effects on respiratory and haemodynamic functions have been reported in which the size of the bronchoscope may play a part. Two different size bronchoscopes (adult and paediatric) were therefore investigated with regard to bronchoalveolar lavage yield and side effects. METHODS: Twenty mechanically ventilated patients underwent bronchoalveolar lavage with both adult and paediatric bronchoscopes in a randomised sequential manner. RESULTS: In a total of 45 pairs of bronchoalveolar lavage procedures no difference was noted between adult and paediatric bronchoscopes with regard to total cell yield, differential cell count, and microbiological results. Peak intratracheal pressure increased with the adult bronchoscope only. Systemic arterial pressures increased more with the adult than with the paediatric bronchoscope. PaO2 decreased with the adult but not with the paediatric bronchoscope. CONCLUSIONS: The paediatric bronchoscope offers a comparable bronchoalveolar lavage yield in mechanically ventilated patients to the adult bronchoscope, while the respiratory and haemodynamic side effects are significantly lower than with the adult size instrument.

[Nitrous oxide (NO) in the treatment of adult respiratory distress syndrome]. / Le monoxyde d'azote (NO) dans le traitement du syndrome de détresse respiratoire de l'adulte.

Inhaled nitric oxide (NO) may be beneficial in patients with adult respiratory distress syndrome (ARDS), by lowering the venous admixture in the lungs and thereby improving the hypoxemia, and by its vasodilator effect which improves pulmonary hypertension. We studied 6 patients with severe ARDS (PaO2/FiO2 9.6 +/- 1.7 kPa and mean pulmonary artery pressure [PAPm] 37 +/- 4 mm Hg) during short term inhalation of NO (30 minutes) at a concentration of 32 ppm. In all patients, we observed the same response, i.e. a significant increase in PaO2 (28 +/- 8% at the same FiO2, p = 0.014) and a decrease in PAPm (15 +/- 5%; p = 0.038) with rapid reversal when NO inhalation was halted. Toxic metabolites of NO, such as NO2, NO3, etc. remained < 1 ppm when measured in different sections of the respiratory circuit. We conclude, in agreement with the study of Rossaint et al. [16], that (1.) inhaled NO may be beneficial in ARDS by improving pulmonary hypertension and gas exchange; (2.) short term NO inhalation is probably safe; (3.) however, the safety of long term administration of NO and a beneficial effect on survival in ARDS patients remain to be shown.

Antibodies selected from whole antiserum by fusion proteins as tools for the study of the topology of mitochondrial membrane proteins. Evidence that the N-terminal extremity of the sixth alpha-helix of the uncoupling protein is facing the matrix.

The reactivity to freeze-thawed mitochondria or submitochondrial particles of a whole antiserum raised against the uncoupling protein has been investigated. Incubation with freeze-thawed brown adipose tissue mitochondria trapped antibodies reactive toward accessible parts of the uncoupling protein. One-third to one-half of antibodies against uncoupling protein which were present in the serum remained free. These antibodies were highly reactive with the vesicles obtained by sonication of mitochondria, in which the matricial side of the inner membrane was made accessible. To define epitopes recognized by the antiserum, different fusion proteins made up of MalE protein and uncoupling protein fragments were used. Immunoaffinity chromatography, using an immobilized purified fusion protein containing amino acids 253 to 290 of uncoupling protein, selected antibodies specifically directed against this part of the protein. A more precise localization of the main epitope recognized by these antibodies is proposed. These purified antibodies reacted with the protein only in submitochondrial particles, indicating a matricial orientation of this epitope. This result, associated with other data concerning uncoupling protein or related mitochondrial carriers such as the ADP/ATP translocator and the phosphate carrier, allowed us to determine the orientation of the sixth alpha-helix of the uncoupling protein.