Ultrasonic device for real-time sewage velocity and suspended particles concentration measurements

In the frame of a technological research and innovation network in water and environment technologies (RITEAU, Réseau de Recherche et d'Innovation Technologique Eau et Environnement), our research group, in collaboration with industrial partners and other research institutions, has been in charge of the development of a suitable flowmeter: an ultrasonic device measuring simultaneously the water flow and the concentration of size classes of suspended particles. Working on the pulsed ultrasound principle, our multi-frequency device (1 to 14 MHz) allows flow velocity and water height measurement and estimation of suspended solids concentration. Velocity measurements rely on the coherent Doppler principle. A self developed frequency estimator, so called Spectral Identification method, was used and compared to the classical Pulse-Pair method. Several measurements campaigns on one wastewater collector of the French city of Strasbourg gave very satisfactory results and showed smaller standard deviation values for the Doppler frequency extracted by the Spectral Identification method. A specific algorithm was also developed for the water height measurements. It relies on the water surface acoustic impedance rupture and its peak localisation and behaviour in the collected backscattering data. This algorithm was positively tested on long time measurements on the same wastewater collector. A large part of the article is devoted to the measurements of the suspended solids concentrations. Our data analysis consists in the adaptation of the well described acoustic behaviour of sand to the behaviour of wastewater particles. Both acoustic attenuation and acoustic backscattering data over multiple frequencies are analyzed for the extrapolation of size classes and respective concentrations. Under dry weather conditions, the massic backscattering coefficient and the overall size distribution showed similar evolution whatever the measurement site was and were suggesting a global wastewater particles behaviour. By comparison to sampling data, our data analysis lead to the characterization of two particle groups: the ones occurring during rain events and the ones typical of wastewater under dry weather conditions. Even with already encouraging results on the several weeks of data recorded on several wastewater collectors, the validation of our data inversion method is still under progress.

[Evolution of facial nerve prognosis in vestibular schwannoma surgery by translabyrinthine approach]

OBJECTIVES OF THE STUDY

To evaluate our results on the postoperative facial function, its pre and preoperative predictive factors, and the application of the surgical technique to lesions of decreasing size.

PATIENTS AND METHODS

A series of 248 patients operated of an unilateral vestibular schwannoma has been reviewed. We have compared the results gathered over two periods corresponding to the evolution of our surgical technique since 1998.

RESULTS

Immediate and 1 year postoperative facial function is significantly better among patients operated after 1998 (satisfactory in 75 and 88% respectively). This trend marked by the improvement of the results since 1998 has to be discussed according to other predictive factors. One of predictive factor is the decrease of the size of the lesion during the same period. The other factors are the hearing level, deafness duration, trigeminal nerve involved, vestibular status and ABR desynchronization.

CONCLUSION

The positive predictive factors are usually correlated with the size of the tumour This implies the necessity of an early diagnosis of the schwannomas. The second predictive factor of the facial function is the use of a soft surgical technique.

Deriving structure from evolution: metazoan segmentation

Segmentation is a common feature of disparate clades of metazoans, and its evolution is a central problem of evolutionary developmental biology. We evolved in silico regulatory networks by a mutation/selection process that just rewards the number of segment boundaries. For segmentation controlled by a static gradient, as in long-germ band insects, a cascade of adjacent repressors reminiscent of gap genes evolves. For sequential segmentation controlled by a moving gradient, similar to vertebrate somitogenesis, we invariably observe a very constrained evolutionary path or funnel. The evolved state is a cell autonomous 'clock and wavefront' model, with the new attribute of a separate bistable system driven by an autonomous clock. Early stages in the evolution of both modes of segmentation are functionally similar, and simulations suggest a possible path for their interconversion. Our computation illustrates how complex traits can evolve by the incremental addition of new functions on top of pre-existing traits.

Intérêt du Breastfeeding Assessment Score pour la prédiction du sevrage précoce de l'allaitement maternel en France

BACKGROUND

The Breastfeeding Assessment Score (BAS) was derived to help identify mothers at increased risk of early weaning in United States. Data are currently lacking on the accuracy of the BAS for French mother-infant pairs.

OBJECTIVE

To assess the accuracy of the BAS in a French validation cohort.

METHODS

We used the original data from a prospective cohort study of 488 mothers who were breastfeeding at discharge in 9 maternity wards in 2005. The outcome measures were assessed using structured follow-up telephone interviews at 4 and 26 weeks.

RESULTS

The weaning rate was 3% at 14 days of infant age. The corresponding area under ROC curve was 0.73 [0.60-0.85] and was comparable to that observed in the derivation cohort (0.75). For a cut point of 8 recommended by the authors of the BAS, 43% of mother-infant pairs were categorized at high risk and the weaning rate in this subgroup was 5%. The mother-infant pairs with a score lower than 8 had a shorter median breastfeeding duration (18 versus 20 weeks, P=0.02), were more likely to report breastfeeding difficulties after discharge (63% versus 53%, P=0.03), and were less likely to be "very satisfied" with breastfeeding experience (66% versus 77%, P=0.007).

CONCLUSION

The intrinsic properties of the BAS are robust. However, its use would be of limited interest in France because of the relatively low rate of early weaning. Randomized trials are needed before recommending routine use of BAS-based breastfeeding support intervention.

[Epidemiology and clinical characteristics of childhood parapneumonic empyemas]

Several studies have reported an increasing incidence of childhood parapneumonic empyemas in various countries.

AIM OF THE STUDY

The aim of our study was to estimate the annual incidence of complicated community-acquired pneumonias in children during a 9-year period in a French area and to describe the epidemiological and clinical characteristics of these complications.

POPULATION AND METHODS

We have listed the children from 28 days to 15 years old, hospitalized in the 2 children hospitals of the Isere district for a community-acquired pneumonia complicated with a pleural empyema or a pulmonary abscess from 1995 to 2003.

RESULTS

During the study period, 90 children were hospitalized for a complicated pneumonia including 83 pleural empyemas and 7 isolated lung abscess. The average number of cases was 4 per year from 1995 to 1998 then increased since 1999 to reach 34 cases in 2003, according to a linear model (P<0,001). The incidence of the complicated pneumonia, plotted to the paediatric population of the area has gone up from 0.5 per 100000 to 13 per 100000 children between 1995 and 2003.

CONCLUSION

The incidence of the complicated pneumonias in children increased since 1999 in a French area. Additional investigations are necessary to identify the causes of this increase.

Association of eNOS Glu298Asp gene polymorphism with circadian blood pressure rhythm

Hypertensive patients with altered circadian blood pressure (BP) profile experience greater repercussion of hypertension on target organs and a higher risk of cardiovascular events, compared with those with physiological variations in BP. It has been demonstrated in animal models, that circadian variations in BP depend on several regulatory systems, in particular the nitric oxide-cGMP pathway. eNOS298 Glu/Asp polymorphism is a functional variant and may alter the amount of NO generated or eNOS activity. The objective of the present study was to find out whether eNOS298 gene polymorphism affects circadian BP regulation in 110 healthy subjects and 155 never-treated hypertensive patients recruited at Hypertension Units in Grenoble, Toulouse and Lille (France).

Prospective assessment of fluoroquinolone use in a teaching hospital

The aim of this study was to review the use of fluoroquinolone (FQ) drugs in a teaching hospital and to bring to light the factors associated with FQ misuse. A prospective observational study of FQ prescriptions was conducted in a 2,200-bed teaching hospital. Every hospitalized patient receiving a FQ drug during the 3-week survey period was included. A questionnaire was filled out using medical records and face-to-face interviews with FQ prescribers. An infectious diseases specialist reviewed the questionnaires and analyzed FQ therapy according to local guidelines for FQ prescription. Among the group of 174 patients included, FQ therapy was inappropriate in 88 cases (50.6%; 95% CI 43-58) for the following reasons: inappropriate clinical setting, 43; non-first-line recommendation, 24; inappropriate choice of FQ agent, 9; and inappropriate combination of FQs, 12. FQ prescriptions did not comply with prescription rules in 45 cases (25.9%; 95% CI 20-33). Appropriateness and compliance overlapped for 17 of these 45 patients who received an inappropriate FQ course that did not comply with prescription rules. Finally, FQ therapy was misused for 116 of the 174 patients (66.6%; 95% CI 59-74). Characteristics linked with FQ misuse were hospitalization in surgical wards (p = 0.03), intravenous therapy (p < 0.01), and presumptive therapy (p = 0.05). The FQ misuse rate progressively decreased during the survey period (p = 0.04). FQ misuse was a common phenomenon in the teaching hospital studied. The significant improvement in FQ prescribing practices observed during the study period demonstrates that frequent review of antibiotic use with prescribers is warranted.

[Comparison of mortality according to the revascularisation strategies and the symptom-to-management delay in ST-segment elevation myocardial infarction]

The aim of this study was to compare the mortality associated to primary angioplasty and thrombolysis in patients managed for an elevated ST-segment acute coronary syndrome in less than or more than 3 hours after the onset of symptoms. We analyzed the in-hospital mortality of 846 patients (including 276 [33%] treated by primary angioplasty, 511 [60%] by thrombolysis, and 59 [7%] without revascularisation) included from October 2002 to December 2003 in a registry of patients with an elevated ST-segment acute coronary syndrome managed in less than 12 hours in Northern Alps districts. The overall in-hospital mortality was at 6.0% (51/846). For the 631 managed in <3 hours, the mortality rates were respectively at 5.0%, 4.6% and 11.1% respectively in case of primary angioplasty, thrombolysis and without revascularisation (p=0.21). For the 215 patients with pain lasting more than 3 hours, the mortality rates were at 2.7%, 10.3% and 21.7% in case of primary angioplasty, thrombolysis and no revascularisation, respectively (p=0.01). In the multivariable analysis, the OR of death in case of thrombolysis compared to primary angioplasty was at 1.65 (95% IC: 0.73 - 3.75) for patients with pain " 3 hours, and 4.98 (95% IC: 1.32-18.37) for those with pain > 3 hours. These results are in line with randomized trials conclusions and confirm the international guidelines suggesting primary angioplasty for patients with a chest pain >3 hours and either angioplasty or thrombolysis in case of chest pain < 3 hours.

Intracellular residency is frequently associated with recurrent Staphylococcus aureus rhinosinusitis

AIM

The prevalence of intracellular Staphylococcus aureus organisms in the nasal mucosa of patients with recurrent infectious rhinosinusitis episodes was studied.

METHOD

Twenty-seven consecutive adult patients who failed medical management of chronic rhinosinusitis (CRS) of multiple origins, associated or not with nasal polyposis, were consecutively enrolled for endonasal sinus surgery (including partial middle turbinectomy, middle antrostomy, ethmoidectomy, sphenoidotomy) and followed for a 12-month post-operative period.

RESULTS

Seventeen of these patients showed the presence of intracellular S. aureus as detected by confocal laser scan immunofluorescence microscopy in epithelial cells of surgical intranasal biopsy specimens. Nine of the patients with and two without intracellular bacteria yielded S. aureus in endoscopically guided cultures of middle meatus secretions, despite the recent administration of prophylactic antibiotics. Eleven of the 17 patients with intracellular S. aureus relapsed for rhinosinusitis within the 12-month follow-up period. Molecular typing of sequential S. aureus isolates demonstrated the persistence of unique patient-specific S. aureus clonotypes in nine of the patients with intracellular bacteria during the 12-month follow-up.

CONCLUSION

The presence of intracellular S. aureus in epithelial cells of the nasal mucosa is a significant risk factor for recurrent episodes of rhinosinusitis due to persistent bacterial clonotypes, which appear refractory to antimicrobial and surgical therapy.

[Analysis of the accuracy of a coronary syndrome register]

Registers of the management of infarction can complement information obtained from randomised trials evaluating the methods and practice of treatment. In order to do this, the quality of the registers must be assured, and in particular the accuracy of the recorded cases. The objective of this study was to evaluate the accuracy of a register for the in-hospital and pre-hospital management of acute coronary syndromes with ST segment elevation of less than 12 hours' duration. Using a capture-recapture method, the study compared cases in the register with eligible cases present in the hospital and emergency ambulance service databases at two establishments, giving a recruitment rate of 61%. The rate of accuracy was estimated at 84% (95% CI [82 ; 86]). The independent factors associated with failure of notification were female sex (ORa=6.65 [2.04-21.69]), presentation at nights, weekends or bank holidays (ORa=4.13 [1.33-12.85]), direct admission to hospital without passing by the emergency ambulance service (ORa=2.85 [1.03-7.69]), primary angioplasty (ORa=6.18 [1.60-23.79]) and the absence of reperfusion (ORa=40.38 [6.21-262.40]). With more than 80% accuracy, the results produced by the register are robust. The selection bias linked to the under-representation of certain subgroups, while real, has only a marginal impact on estimates derived from the register. Factors associated with failure of notification should be taken into account when operating such a register.

[Adequacy of antibiotic therapy to guidelines for urinary tract infection in hospital]

OBJECTIVE

We estimated the adequacy of antibiotic therapy to guidelines for nosocomial and community-acquired urinary tract infections in hospital.

DESIGN

For 4 weeks, all adult patients hospitalized with positive bacteriuria were included in our retrospective study. Data was collected from urine culture results and from patient medical files. Adequacy to guidelines was analyzed by two infectious disease specialists, focusing on the indication, antibiotic choice, dosage, route of administration, and duration of treatment.

RESULTS

Overall 202 patients were enrolled in the study (63.9% women). The decision of initiating or not antibiotic therapy was appropriate in 66.8% of cases. Antibiotherapy indication and antibiotic choice were adequate in 94 cases in empiric prescription (50.8%) and in 123 cases (60.9%) after receiving culture antibiogram results. Route of administration was adequate in 94.4% and dosage in 70.8% of prescriptions. This poor compliance with guidelines was mainly due to unnecessary prescriptions in asymptomatic bacteriuria, unnecessary biotherapies and spectrum errors.

CONCLUSIONS

It seems important to remind prescribers of recommendations for urinary tract infections.