Neural progenitor fate decision defects, cortical hypoplasia and behavioral impairment in Celsr1-deficient mice.

The development of the cerebral cortex is a tightly regulated process that relies on exquisitely coordinated actions of intrinsic and extrinsic cues. Here, we show that the communication between forebrain meninges and apical neural progenitor cells (aNPC) is essential to cortical development, and that the basal compartment of aNPC is key to this communication process. We found that Celsr1, a cadherin of the adhesion G protein coupled receptor family, controls branching of aNPC basal processes abutting the meninges and thereby regulates retinoic acid (RA)-dependent neurogenesis. Loss-of-function of Celsr1 results in a decreased number of endfeet, modifies RA-dependent transcriptional activity and biases aNPC commitment toward self-renewal at the expense of basal progenitor and neuron production. The mutant cortex has a reduced number of neurons, and Celsr1 mutant mice exhibit microcephaly and behavioral abnormalities. Our results uncover an important role for Celsr1 protein and for the basal compartment of neural progenitor cells in fate decision during the development of the cerebral cortex.

Statistical analysis of the effluent quality of 231 on-site sanitation facilities in France monitored during a 6-year period.

On-site wastewater treatment systems are approved by the French regulation based on the results of platform tests following the European standard NF EN 12566-3. In addition to this approval for the treatment system, at least 90% of outlet concentrations have to be below 30 mg L-1 for total suspended solids (TSS) and 35 mg L-1 for biochemical oxygen demand. The aim of this study is to evaluate the effluent quality of these treatment systems on site, i.e. under real operating conditions, and to assess their performances. Between 2011 and 2016, 1,286 treated wastewater samples were taken from 231 on-site sanitation facilities in France. Data collected are heterogeneous and a robust statistical methodology (using a generalized log-linear model) was used to study the effects of four explanatory variables (treatment systems, loading rate, aging and sampling methods) on the distribution of treated wastewater concentrations. The model calculates median outlet concentrations depending on the effects identified. Its application allowed studying and comparing the outlet median concentrations of 21 on-site sanitation systems classified into nine categories and three groups. Four treatment systems out of the 21 monitored showed TSS median outlet concentrations below 10 mg L-1 and four treatment systems have TSS medians higher than the regulatory threshold of 30 mg L-1.

Macrophytes are highly sensitive to the herbicide diquat dibromide in test systems of varying complexity.

The herbicide diquat dibromide is used in North America to manage nuisance macrophytes. However, its effect on native macrophytes is less clear and it could cause indirect effects on other aquatic biota. This study determined the sensitivity of both native and non-native macrophytes grown in test systems with varying complexity to diquat dibromide applied directly to water following label directions. In an outdoor mesocosm experiment and single species greenhouse concentration-response tests, Elodea canadensis Michx., Myriophyllum spicatum L., Ceratophyllum demersum L. and Hydrocharis morsus-ranae L. were exposed to a range of diquat dibromide concentrations (4.7 - 1153 µg/L), corresponding to 0.4 - 100% of the recommended label rate of the formulated product. The mesocosm experiment contained all four plant taxa in the same system along with caged amphipods (Hyalella azteca Saus.), tadpoles (Lithobates pipiens Schreber), phytoplankton and periphyton; however, this study focuses on the macrophytes only. In both test systems, severe direct effects of diquat dibromide on macrophytes were detected, with almost 100% mortality of all macrophytes in both test systems at 74 µg/L. The most sensitive species in the single species tests, E. canadensis, showed almost 100% mortality at concentrations below the HPLC-based method detection limit of 5 µg/L. Effects occurred very rapidly and showed no difference in severity between native and non-native macrophytes or complexity of test systems. These results suggest that diquat dibromide could be applied at a considerably lower label rate, depending on the characteristics of the waterbody, while still achieving effective control of nuisance macrophytes.

Comparison of the design criteria of 141 onsite wastewater treatment systems available on the French market.

New EC standards published in 2009 led to a surge in onsite wastewater treatment systems reaching the European market. Here we summarize their technical aspects and compare them to known values used in centralized wastewater treatment. The paper deals with two types of processes: attached-growth systems (AGS) on fine media and suspended-growth systems (SGS). Covering 141 technical approvals and 36 manufacturers, we compare onsite design criteria against the centralized wastewater design criteria for each process. The systems use a wide range of materials for bacterial growth, from soil, sand or gravel to zeolite, coconut shavings or rockwool cubes, with a huge range of variation in useful surface, from 0.26 m2/PE for one rockwool cube filter to 5 m2/PE for a (traditional system) vertical sand filter. Some rockwool can handle applied daily surface load of 160 g BOD5/m2. SGS design parameters range from 0.025 to 0.34 kg BOD5 per kg MLVSS/d with hydraulic retention times of 0.28-3.7 d. For clarifier design, water velocity ranges from 0.15 to 1.47 m/h. In the sludge line, sludge storage volume ranges from 0.125 down to just 0.56 m3/PE.

Prenatal diagnosis and prognosis of accelerated idioventricular rhythm.

OBJECTIVES: As postnatal identification of accelerated idioventricular rhythm (AIVR) relies on specific electrocardiographic patterns, prenatal diagnosis of this condition is challenging and its true incidence is unknown. The objectives of this study were to evaluate the performance of prenatal ultrasonography in identifying intrauterine cardiocirculatory events linked to specific electrocardiographic signs of postnatal AIVR, including left or right ventricular origin, and to assess the prenatal prognosis of this arrhythmia. METHODS: We reviewed Doppler tracings from the superior vena cava/ascending aorta (SVC/Ao), ductus venosus (DV), ductus arteriosus (DA) and aortic isthmus (AoI), as well as simultaneous M-mode recordings of septal and left ventricular wall motions of fetuses diagnosed with AIVR from January 2004 to December 2014. RESULTS: Three cases of AIVR were identified among 27 912 fetuses. SVC/Ao Doppler flow recordings revealed atrioventricular dissociation (ventricular rates within 20% of atrial rates) in all three fetuses and episodes of isorhythmic atrioventricular dissociation in one, while M-mode confirmed normal left ventricular shortening fraction in all cases. Fusion beats were observed on AoI tracing in one fetus, while simultaneous recordings of AoI and DA revealed signs of right bundle branch block in one case and left bundle branch block in the other two. On DV Doppler recordings, retrograde a-waves in the presence of simultaneous atrial and ventricular contractions were observed in all three fetuses, leading to an increase in central venous pressure in all and hydrops fetalis in two cases without evidence of ventricular dysfunction. CONCLUSIONS: Echocardiographic criteria required for postnatal diagnosis of AIVR can be documented in utero using specific ultrasonographic approaches. During fetal life, AIVR may not be a benign entity. Hydrops fetalis is frequently associated with AIVR because of increase in central venous pressure related to simultaneous atrioventricular contractions; thus, the ultrasonographic investigation protocol of fetuses with unexplained hydrops fetalis should aim at ruling out AIVR and include Doppler flow recordings in SVC/Ao, DV, AoI, DA and umbilical vein. Copyright © 2016 ISUOG. Published by John Wiley & Sons Ltd.

Oxygen profile and clogging in vertical flow sand filters for on-site wastewater treatment.

13 million people (about 20% of the population) use on-site wastewater treatment in France. Buried vertical sand filters are often built, especially when the soil permeability is not sufficient for septic tank effluent infiltration in undisturbed soil. Clogging is one of the main problems deteriorating the operation of vertical flow filters for wastewater treatment. The extent of clogging is not easily assessed, especially in buried vertical flow sand filters. We suggest examining two possible ways of detecting early clogging: (1) NH4-N/NO3-N outlet concentration ratio, and (2) oxygen measurement within the porous media. Two pilot-scale filters were equipped with probes for oxygen concentration measurements and samples were taken at different depths for pollutant characterization. Influent and effluent grab-samples were taken three times a week. The systems were operated using batch-feeding of septic tank effluent. Qualitative description of oxygen transfer processes under unclogged and clogged conditions is presented. NH4-N outlet concentration appears to be useless for early clogging detection. However, NO3-N outlet concentration and oxygen content allows us to diagnose the early clogging of the system.

Vertical flow constructed wetlands subject to load variations: an improved design methodology connected to outlet quality objectives.

This study surveyed four campsites and four rural villages of major tourist interest, called tourist-interest or ti-villages, that were monitored for several years, generating over 70 performance balances for vertical flow constructed wetlands (VFCWs) that were intentionally scaled down for experimental trials. The wastewater effectively qualifies as domestic sewage, although relatively concentrated, with the campsites presenting particularly high nitrogen concentrations (122 gTKN L(-1)) (TKN: total Kjeldahl nitrogen). The applied daily loads were also particularly high, with some combinations of load parameters (hydraulic load, organic matter, TKN) leading to 400% overloading. Even under those drastic conditions, the quality of effluent remained excellent on the characteristic organic matter parameters, with removal performances always over 85%. Analysis of the dataset points to two major design thresholds: for campsites, in order to maintain a 73% nitrification rate even at the height of the summer season, the load applied onto the first stage filter in operation could achieve up to 600 gCOD m(-2) day(-1) (COD: chemical oxygen demand). For tourist-interest villages, in order to maintain an 85% nitrification rate, the load applied onto the second stage filter in operation could achieve up to 22 gTKN m(-2).day(-1). Here, VFCWs were demonstrated to robustly handle a massive increase in loads applied, providing the construction and operation stringently follow design standards and practices.

Is exposure to night-time traffic noise a risk factor for purchase of anxiolytic-hypnotic medication? A cohort study.

BACKGROUND: Studies suggest that road traffic noise increases risks of sleep disturbances, anxiety and depressive symptoms, but few have focused on psychotropic drug use. We examined whether exposure to night-time road traffic noise in Marseilles (France) is associated with an increased risk of purchasing anxiolytic or hypnotic medications. METHODS: Cohort of 190,617 inhabitants of Marseilles (aged 18-64 years) covered by the National Health Insurance Fund. We used the CadnaA noise propagation prediction model to calculate a potential road noise exposure indicator at dwellings for the night-period: Ln. Association between the number of purchases of anxiolytics-hypnotics in 2008-9 and the Ln was analysed with a zero-inflated negative binomial (ZINB) model adjusted for characteristics of individuals (sociodemographic, consultations with general practitioners, presence of chronic psychiatric disorder), prescribers (demographic, specialty, workload) and neighbourhoods (medical density, complaints filed for environmental noise). Analyses were stratified by the deprivation level of the census block of residence to control for the confounding effects of neighbourhood socio-economic status. RESULTS: The ZINB model showed a small but significant increase in the risk of purchasing higher numbers of anxiolytics-hypnotics for Ln greater than 55 dB(A) only in the low deprivation stratum. CONCLUSION: We found some evidence that potential exposure to night-time road traffic noise might affect individual use of anxiolytics-hypnotics. Further research based on strictly individual approaches is warranted to assess exposure to road traffic noise more precisely and reliably than allowed by noise propagation prediction models.

Lymphogranuloma venereum in Quebec: Re-emergence among men who have sex with men.

BACKGROUND: Lymphogranuloma venereum (LGV) is a sexually transmitted infection (STI) caused by Chlamydia trachomatis genotypes L1, L2 and L3. This LGV is associated with significant morbidity and increased risk of HIV transmission. While fewer than two cases per year were reported in Quebec before 2005, LGV emerged in 2005-2006 with 69 cases, followed by a period of low incidence (2007-2012), and subsequent re-emergence since 2013. OBJECTIVES: To describe the incidence of LGV in Quebec and the characteristics of the affected population, including demographics and risk factors, clinical manifestations, laboratory tests, treatments and reinfection rates. METHODS: Descriptive data were collected from the notifiable diseases records through the Institut national de santé publique du Québec (INSPQ) infocentre portal. Questionnaires were obtained through the enhanced surveillance system and transmitted anonymously to the Quebec Ministry of Health. In-depth analysis was performed on cases from 2013 to 2016. RESULTS: There were 338 cases of LGV over the four-year period in Quebec. All cases were male, excluding one transsexual. Mean age was 41 years. Most lived in Montréal (81%) and were men who have sex with men (MSM; 99%). The majority (83%) reported four sexual partners or more in the last year, met mostly through the Internet (77%) and in saunas (73%). Frequency of sexual intercourse with out-of-province residents decreased in 2013-2016 (27%) compared with 2005-2012 (38%). History of STIs was frequent: 83% were HIV-infected, 81% reported previous syphilis and 78% previous gonorrhea. Recreational drug use was frequent (57%), reaching 71% in 2016. Most cases were symptomatic, a proportion which decreased in 2016 (68%) compared with 2013-2015 (82%; p=0.006). Clinical presentations included proctitis (86%), lymphadenopathy (13%) and ulcer/papule (12%). Reinfections, mostly within two years of first infection, occurred in 35 individuals (10%).Conclusion: The re-emergence of LGV in Quebec involves an urban subpopulation composed almost exclusively of MSM with STIs, who have a high number of partners and often use drugs.

[Groundwater quality in two arid areas of Morocco: impact of pollution on biodiversity and paleogeographic implications]. / Qualité des eaux souterraines dans deux régions arides du Maroc: impact des pollutions sur la biodiversité et implications paléogéographiques.

The biodiversity and the quality of subterranean waters have been comparatively studied in the Haouz plain near Marrakesh and in the Tafilalet, in south-eastern Morocco. For this purpose, physicochemical and faunistic analyses were carried out on the water of ten wells and springs located in the area of Marrakesh, and in Errachidia area respectively. In the wells of Marrakesh, the average stygobiologic diversity is relatively high in the wells located upstream the dumping from the city where the ground water presents low contents of nitrates and orthophosphates. In contrast, the wells located in the spreading zone of Marrakesh wastewaters are characterized by the scarcity or the absence of stygobitic species; in these latter wells, the water is highly polluted. It is rich in nitrates, nitrites, ammonium, and the conductivity is rather high. In the area of Errachidia the faunistic inventory gathers some ten species, some of which are living in hot springs. The subterranean water is highly mineralised. In the two studied areas, the biodiversity decreases when well water is locally polluted, and the subterranean fauna completely disappears if the degree of contamination is important. This relation between the biodiversity and water quality which had already appeared in surface water, is confirmed within the wells of Marrakech. The groundwater fauna of both two areas presents similarities in relation to their geological history, mainly the various marine cycles of marine transgressions-regressions, which were at the origin of the settlement of the ancestors of the extant species, and the Atlasic orogenesis which separated the common ancestral populations into two separated stocks, involving a different evolution of the ancestors and a resulting speciation by vicariance.

Assessment of wetland/upland vegetation communities and evaluation of soil-plant contamination by polycyclic aromatic hydrocarbons and trace metals in regions near oil sands mining in Alberta.

Oil sands mining in Alberta, Canada, has been steadily increasing over the last 50years. The extent to which the surrounding vegetation has been altered/contaminated by pollutants released during bitumen extraction has not been a focus of oil sands environmental monitoring efforts. The objectives of this study were to assess plant species richness and composition in wetlands and uplands in the vicinity of oil sands mining areas and to measure levels of contamination of trace metals and polycyclic aromatic hydrocarbons (PAHs) in soils and plants. Twenty-two sites were selected in three locations: near to (OS, n=7), West (n=7), and East (n=8) of oil sands mining operations. Aboveground plant species were inventoried and soil was collected for a seedbank study. Soils and plants were collected for analyses of 28 metals and 40 parent and alkylated PAHs. Plant species richness and composition differed significantly among locations. More species were found in the OS sites, many of them being non-native, than in East and West sites, which contained almost exclusively native perennials. PAH levels were significantly higher in OS sites, and were mostly comprised of alkylated PAHs. Patterns of PAH distribution indicated contamination from bitumen/petroleum in four sites; other combustion types may have affected five additional sites at different levels. Metals were also elevated in OS sites. Metal levels were significantly correlated with distance to upgrader facilities. Ratios of some metals in soil vs. above- and belowground plant parts were significantly higher in West and East than in OS sites, likely due in part to pH as soil was acidic at the East and West locations but alkaline at OS sites. This study showed that sites located near oil sands mining operations were contaminated with PAHs and metals, and that the vegetation composition at these sites greatly differed from less disturbed areas.

The French National Mesothelioma Surveillance Program.

OBJECTIVES: The French National Mesothelioma Surveillance Program (NMSP) was established in 1998 by the National Institute for Health Surveillance (InVS). Its objectives are to estimate the trends in mesothelioma incidence and the proportion attributable to occupational asbestos exposure, to help improve its pathology diagnosis, to assess its compensation as an occupational disease, and to contribute to research. METHODS: The NMSP records incident pleural tumours in 21 French districts that cover a population of approximately 16 million people (a quarter of the French population). A standardised procedure of pathological and clinical diagnosis ascertainment is used. Lifetime exposure to asbestos and to other factors (man made mineral fibres, ionising radiation, SV40 virus) is reconstructed, and a case-control study was also conducted. The proportion of mesothelioma compensated as an occupational disease was assessed. RESULTS: Depending on the hypothesis, the estimated number of incident cases in 1998 ranged from 660 to 761 (women: 127 to 146; men: 533 to 615). Among men, the industries with the highest risks of mesothelioma are construction and ship repair, asbestos industry, and manufacture of metal construction materials; the occupations at highest risk are plumbers, pipe-fitters, and sheet-metal workers. The attributable risk fraction for occupational asbestos exposure in men was 83.2% (95% CI 76.8 to 89.6). The initial pathologist's diagnosis was confirmed in 67% of cases, ruled out in 13%, and left uncertain in the others; for half of the latter, the clinical findings supported a mesothelioma diagnosis. In all, 62% applied for designation of an occupational disease, and 91% of these were receiving workers' compensation. CONCLUSIONS: The NMSP is a large scale epidemiological surveillance system with several original aspects, providing important information to improve the knowledge of malignant pleural mesothelioma, such as monitoring the evolution of its incidence, of high risk occupations and economic sectors, and improving pathology techniques.

Human malignant mesothelioma cell growth: activation of janus kinase 2 and signal transducer and activator of transcription 1alpha for inhibition by interferon-gamma.

Intrapleural injections of recombinant human IFN-gamma have shown some efficacy in reducing tumor growth in early stages of diffuse malignant mesothelioma (DMM). Here, we have addressed the potential therapeutic effect of IFN-gamma in DMM by investigating the activation of the JAK/STAT signaling pathway in seven human mesothelioma cell lines (HMCLs) that were differentially responsive to the antiproliferative activity of IFN-gamma. We showed that janus kinase 2 (JAK2) and signal transducer and activator of transcription 1 (STAT1) were phosphorylated on tyrosine residues within 15 min in all the HMCLs in which IFN-gamma (500 units/ml) inhibited proliferation. In addition, STAT1 binding activity to the gamma-activated sites DNA sequence was detected within 15 min in electrophoretic mobility-shift assay analysis, and IFN regulatory factor-1 RNA expression was observed within 6 h in the more responsive cells (72.7-95.2% inhibition of DNA synthesis after 72 h of treatment). Conversely, in several HMCLs, absent or limited growth suppressive effect (less than 22% inhibition of DNA synthesis) was associated with alterations in expression or activation of JAK2 or STAT1 or, downstream, with low induction of IFN regulatory factor-1 RNA expression and/or STAT1 protein expression following IFN-gamma treatment. These data suggest that at least part of the IFN-gamma effect on proliferation of HMCLs is mediated directly through activation of the JAK/STAT1 signaling pathway, and it could account for the antitumoral activity reported in DMM patients treated with IFN-gamma.

Evaluating trivalent chromium toxicity on wild terrestrial and wetland plants.

Elevated chromium levels in soil from mining can impact the environment, including plants. Mining of chromium is concentrated in South Africa, several Asian countries, and potentially in Northern Ontario, Canada, raising concerns since chromium toxicity to wild plants is poorly understood. In the first experiment, concentration-response tests were conducted to evaluate effects of chromium on terrestrial and wetland plants. Following established guidelines using artificial soil, seeds of 32 species were exposed to chromium (Cr(3+)) at concentrations simulating contamination (0-1000 mg kg(-1)). This study found that low levels of chromium (250 mg kg(-1)) adversely affected the germination of 22% of species (33% of all families), while higher levels (500 and 1000 mg kg(-1)) affected 69% and 94% of species, respectively, from 89% of the families. Secondly, effects on seedbanks were studied using soil collected in Northern Ontario and exposed to Cr(3+) at equivalent concentrations (0-1000 mg kg(-1)). Effects were less severe in the seedbank study with significant differences only observed at 1000 mg kg(-1). Seeds exposed to Cr(3+) during stratification were greatly affected. Seed size was a contributing factor as was possibly the seed coat barrier. This study represents an initial step in understanding Cr(3+) toxicity on wild plants and could form the basis for future risk assessments.

Note: Spin-exchange optical pumping in a van.

The advent of spin-hyperpolarization techniques designed to overcome the sensitivity issue of nuclear magnetic resonance owing to polarization transfer from more ordered systems has recently raised great enthusiasm. However, the out-of-equilibrium character of the polarization requires a close proximity between the area of production and the site of use. We present here a mobile spin-exchange optical pumping setup that enables production of laser-polarized noble gases in a standalone mode, in close proximity to hospitals or research laboratories. Only compressed air and mains power need to be supplied by the host laboratory.

Morphologic and hemodynamic consequences after percutaneous balloon valvotomy for neonatal pulmonary stenosis: medium-term follow-up.

OBJECTIVES: This study sought to evaluate ventricular and valvular morphologic changes, hemodynamic consequences and clinical outcomes of pulmonary balloon valvotomy performed in the neonatal period. BACKGROUND: Previous studies support percutaneous balloon valvotomy as the management option of choice for infants and children with valvular pulmonary stenosis. Less information is available to define the impact of valvotomy on the clinical course when performed in the neonatal period. METHODS: Patient records, catheterization data, cineangiograms and selected echocardiograms (initial and most recent studies) of 37 consecutive neonates undergoing attempted balloon dilation were reviewed. RESULTS: Dilation was accomplished in 35 (94%) of 37 attempts. Immediately after dilation, the transvalvular peak to peak systolic gradient decreased from 60 +/- 22 mm Hg (mean +/- SD, range 20 to 100) to 11 +/- 10 mm Hg (range 0 to 45) (p < 0.0001), and the right ventricular/aortic systolic pressure ratio decreased from 1.25 +/- 0.43 (range 0.5 to 2.6) to 0.66 +/- 0.22 (range 0.2 to 1) (p < 0.0001). Oxygen saturation measured by percutaneous oximetry increased from 80 +/- 7% to 92 +/- 4% (p < 0.0001). Three patients died (8%), and two required repeat balloon dilation. At the follow-up visit (median 31 months, range 6 months to 8 years), the estimated peak instantaneous Doppler gradient was 15 +/- 9 mm Hg (range 6 to 36). Thickening of valve leaflets, initially present in 93% of patients, was found in only 4%, and leaflet mobility improved in all. Hypoplasia of the right ventricle, initially present in 31%, was found in only 4% at the latest evaluation. Pulmonary annulus diameter Z score increased from -3 +/- 1.0 to 0 +/- 0.1 (p < 0.0001). Freedom from reintervention was 90%, 84% and 84% at 1, 2 and 8 years, respectively. CONCLUSIONS: These data support the application of balloon valvotomy as the initial intervention in the treatment algorithm for neonates with critical pulmonary valve stenosis. Medium-term follow-up observations demonstrate sustained hemodynamic relief and support maturation of the right ventricle and pulmonary valve annulus, with the expectation of a good long-term outcome.

Myocardial perfusion, function and exercise tolerance after the arterial switch operation.

OBJECTIVES: This study was conducted to determine the prevalence of myocardial perfusion abnormalities at rest and exercise and to assess exercise capacity in children after the arterial switch operation. BACKGROUND: There have been sporadic reports of myocardial ischemia or sudden death in children after the arterial switch operation for transposition of the great arteries, possibly related to inadequate coronary perfusion due to kinking or stenosis of the translocated coronary arteries. METHODS: Myocardial perfusion at rest and peak exercise was assessed using the scintigraphic agent technetium-99m methoxyisobutyl isonitrile (sestamibi). Exercise capacity was determined with a modified Bruce protocol. Ambulatory electrocardiographic (ECG) Holter monitoring was performed. Ventricular function, contractility and wall motion were assessed echocardiographically. RESULTS: Twenty-three children (aged 4.2 to 7.9 years) underwent evaluation. Abnormalities were found on the rest perfusion scans in 22 children (95.6%). The left ventricular myocardium was divided into 13 segments for analysis. Of 299 rest segments, 225 (75.3%) were normal, 11 (3.7%) showed mild defects, 45 (15%) moderate defects and 18 (6%) severe defects at rest. At peak exercise, 237 segments (79.3%) were normal, 24 (8%) showed mild defects, 33 (11%) moderate defects and 5 (1.7%) severe defects. Compared with rest studies, myocardial perfusion grade at exercise was unchanged in 246 segments (82.3%), improved in 42 (14%) and worsened in 11 (3.7%). All patients had normal exercise tolerance without symptoms or ischemic ECG changes. No ventricular tachycardia was seen on Holter monitoring. All patients had a shortening fraction > or = 27%. Left ventricular contractility was normal in 12 children in whom it was assessed. Regional wall motion was normal in 17 children with adequate echocardiographic images for this analysis. CONCLUSIONS: Myocardial perfusion scan abnormalities assessed by technetium-99m sestamibi are common after an arterial switch operation. These abnormalities are of uncertain clinical significance and generally lessen with exercise. The normal exercise tolerance without symptoms or ECG changes suggests that myocardial perfusion is adequate during the physiologic stress of exercise in children up to 8 years after an arterial switch operation.

Waste stabilisation ponds in France: state of the art and recent trends.

Waste stabilisation ponds represent 20% of the total number of wastewater treatment plants in France. Practical expertise acquired during these last 20 years has led to modification in the design of the first facultative basin of WSP systems. Its active surface area is now dimensioned at 6 m2(p.e.)(-1) in order to limit the risk of malfunctioning. The cumulated surface of the 2nd and 3rd basin is maintained at 5 m2(p.e.)(-1). Another practical point is also that WSPs must receive mainly diluted influents. Globally, the plants are on average far from their nominal loadings, which explains why the first sludge removals took place on average 13 years after being put in operation. Based on a representative sample of plants, i.e. 1 5% of the French WSPs, it has been possible to estimate the time, material means and cost needed for sludge removal as well as the amount of sludge accumulated. The sludge removed at the 1st yields on average 110 L (p.e.)(-1) which represents 12 kg DM (p.e.)(-1). The current trend of increasing the quality levels necessary for discharge into sensitive receiving bodies has led to adaptive solutions of polishing treatments by intermittent sand filter systems with or without the plantation of reeds.

How to treat raw sewage with constructed wetlands: an overview of the French systems.

The development of vertical flow constructed wetlands treating raw wastewater in France has proved to be very successful over the last 20 years. In view of this a survey was carried out on more than 80 plants in order to study their performance and correct the design if necessary. This study shows that such systems perform well in terms of respecting the goals of both low level outlet COD and SS and nitrification. Pollutant removal performance in relation to the loads handled and the specific characteristics of the plants were investigated. Nitrification is shown to be the most sensitive process in such systems and performance in relation to sizing is discussed. Such systems, if well designed, can achieve an outlet level of 60 mg L(-1) in COD, 15 mg L(-1) in SS and 8 mg L(-1) in TKN with an area of 2 - 2.5 m2.PE(-1). The sludge deposit on the first stage must be removed after about 10-15 years.

[New trends in pediatric endocarditis]. / Nuevas tendencias de la endocarditis pediátrica.

OBJECTIVES: To evaluate the epidemiology, etiology and outcome of endocarditis in a cohort of pediatric patients and to compare the main characteristics with our previous experience. MATERIAL AND METHODS: Patients aged less than 18 years of age diagnosed with endocarditis at the Sainte-Justine Hospital, University of Montreal between 1-1986 and 12-2000 were studied. The recent case series was compared with our previous experience from 1960-1985. RESULTS: Fifty-six children with endocarditis were included in the 1986-2000 series: 35 children with congenital heart disease, 15 with serious underlying disease and six healthy children. The mean age was 7 years and 10 months. Fifty-four percent of the patients were boys. The incidence of endocarditis increased from 1.5 cases/year in the 1986-2000 series to 4 cases/year in the 1986-2000 series. In the 1986-2000 series, 10 (17.9 %) patients had a central catheter. Sixteen (28.6 %) patients had a vascular prosthesis. Blood cultures were positive in 50 patients (89 %): Streptococci were found in 48 % of the patients and Staphylococci in 34 %. Echocardiography was positive in 36 of 55 patients (65.4 %). All children were treated with intravenous antibiotics for a mean of 43 +/- 15 days. There were no recurrences. Significant morbidity developed in 26 patients (46 %). Embolic phenomena were seen in 11 children (20 %). Twelve patients (21 %) needed surgery. Of the six healthy children, five developed complications. Overall, seven children (12.5 %) died; all were older than 6 years of age. Comparing our experience from 1960-1985 with that from 1986-2000 revealed that morbidity decreased from 85.7 % to 46.4 % and mortality decreased from 27 % to 12.5 %. CONCLUSIONS: Physicians must recognize that children with underlying immunodeficiency and those with central catheters have an increased risk of endocarditis. Healthy children with endocarditis have a greater risk of complications. Morbidity and mortality due to endocarditis has diminished considerably in recent years.