Effective degradation of organophosphate ester flame retardants and plasticizers in coastal sediments under high urban pressure.

Empirical evidence of the effective degradation at environmentally relevant conditions of organophosphate esters (OPEs) flame retardants and plasticizers in coastal sediments from an impacted area in the NW Mediterranean Sea is provided. Half-lives varied from 23.3 to 77.0 (abiotic conditions) and from 16.8 to 46.8 days (biotic conditions), depending on the compound, highlighting the relevant role of microbial assemblages enhancing OPE degradation. After an immediate significant reduction of the bacterial abundance due to OPE addition to the sediment at the very beginning of the experiment, the observed biodegradation was associated to a general stimulation of the growth of the bacterial community during a first period, but without a marked change of the structure of the community. However, OPE contamination induced a decrease on the diversity of the bacterial community in the coastal sediment, noticeable after 14 days of incubation. It is likely that on one side the contamination had favoured the growth of some bacterial groups maybe involved in the biodegradation of these compounds but, on the other side, had also impacted some sensitive bacteria. The estimated half-lives fill a data gap concerning OPE degradation rates in marine sediments and will be valuable data for the refinement of OPE chemical risk assessment in marine environments, particularly on impacted sites.

Influence of angular positioning of the prosthesis in stapes surgeries with a NiTiBond prosthesis: Investigation in cadaveric temporal bones.

In incus stapedotomy surgeries, the longitudinal direction of the piston prosthesis should ideally be perpendicular to the stapes footplate. However, in reality, some amounts of angular deviation of the prosthesis from the ideal angular position is unavoidable due to anatomical constraints and surgical conditions. This study aims to evaluate the influence of angular positioning of the prosthesis on surgical outcomes in incus stapedotomy and to provide surgical guidelines related to practical tolerance of the angular positioning. In this study, this influence was assessed with a Kurz NiTiBond prosthesis (0.4-mm diameter) and fenestra sizes of 0.5- and 0.6-mm diameter in cadaveric temporal bones (n = 7 including 2 preliminary tests). Angular position of the prosthesis relative to the footplate was modulated by rotating the stapes about the long and short axes of the footplate. At each angular position, the tympanic membrane was acoustically stimulated in the frequency range of 0.2-10 kHz, and motion of the prosthesis was measured using a Laser Doppler vibrometer (LDV). Furthermore, micro-computed tomography (micro-CT) data of the middle-ear ossicles were used for anatomical analysis of angular positioning of the prosthesis. The results showed that changes of angular position of the prosthesis relative to the stapes footplate do not cause significant changes of prosthesis motion until a certain angular position threshold, and sharply attenuate prosthesis motion when the angular position reaches the threshold. The threshold of the angular position, as the tilting angle of the prosthesis from the direction normal to the stapes footplate, was 26.9 ±â€¯2.5° with the fenestration hole of 0.5-mm diameter and 30.6 ±â€¯3.0° with the fenestration hole of 0.6-mm diameter (n = 5, p < 0.01 for difference between the two fenestra sizes). Analysis of the middle-ear anatomy in this study revealed that the tolerances of the angular positions of the prosthesis does not always cover possible positions of prosthesis crimping. This study suggests that if an anterior offset of the stapes head and/or the thickened footplate is suspected, efforts to locate prosthesis crimping closer to the tip of the incus and/or to make a sufficiently large fenestration hole are favorable.

Fate of petroleum hydrocarbons in bioturbated pristine sediments from Caleta Valdés (Patagonia Argentina): An ex situ bioassay.

Petroleum can pollute pristine shorelines as a consequence of accidental spills or chronic leaks. In this study, the fate of petroleum hydrocarbons in soft pristine sediment of Caleta Valdés (Argentina) subject to ex situ simulated oil pollution was assessed. Sedimentary columns were exposed to medium and high concentrations of Escalante Crude Oil (ECO) and incubated in the laboratory during 30 days. Levels of aliphatic hydrocarbons at different depths of the sedimentary column were determined by gas chromatography. Oil penetration was limited to the first three centimetres in both treatments, and under this depth, hydrocarbons were clearly biogenic (terrestrial plants) as in the whole sedimentary column of the control assay. Bioturbation by macrobenthic infauna was strongly impacted by oil pollution which resulted in reduced sediment oxygenation and low burial of petroleum hydrocarbons. This may partly explain the limited hydrocarbon biodegradation observed, as indicated by the relatively high values of the ratios nC17/pristane, nC18/phytane, and total resolved aliphatic hydrocarbons/unresolved complex mixture. Correspondingly, at the end of the experiment the most probable number of hydrocarbon-degrading bacteria reached ~ 103 MPN g-1 dry weight. These values were lower than those found in chronically polluted coastal sediments, reflecting a low activity level of the oil-degrading community. The results highlight the low attenuation capacities of Caleta Valdés pristine sediments to recover its original characteristics in a short time period if an oil spill occurs. In this work, we present a novel and integrative tool to evaluate the fate of petroleum hydrocarbons and their potential damage on pristine sediments.

[Quetiapine and anticholinergic drugs induced ischaemic colitis: A case study]. / Colite ischémique sous quétiapine associée à d'autres molécules anticholinergiques : à propos d'un cas.

INTRODUCTION: The aim of this paper is to underline the need for systematic monitoring of patients treated with anticholinergic antipsychotic drugs. We present the clinical history of a 34-year-old adult, treated with quetiapine in combination with other drugs with anticholinergic effects. CASE REPORT: A 34-year-old male adult had been suffering from bipolar disorder since 2001. He was treated with risperidone, but he was not compliant due to adverse effects, including decreased libido and erectile dysfunction. On June 5th 2012, it was decided to administrate 600mg per day of quetiapine in combination with tropatepine consequent to an episode of agitation and aggressiveness. On June 14th 2012, while the patient was receiving diazepam and valproic acid, loxapine oral solution was introduced. On June 23th, the patient started mentioning digestive disorders, such as diffuse abdominal pain with constipation but continued to pass gaz. On June 25th, at 6:30 am, he declared abdominal pain, which worsened at 8:15 am despite administration of analgesics, followed by malaise and onset of vomiting. His laboratory tests showed leukocytosis 11.2G/L with neutrophils 7.7G/L. The abdomen's radiograph without preparation showed small bowel and colonic air-fluid levels. The result of the CT scan confirmed an occlusive syndrome affecting the whole small gut and colon. At 1 pm, the patient's condition worsened. He received an intramuscular injection of 100mg of loxapine and an opioid treatment, including tramadol and morphine. At 2:30 pm, the clinical condition further deteriorated with an onset of generalized abdominal contracture, the absence of abdominal breathing, sweating, tachycardia at 104 beats per minute, and hypothermia of 34.5°C. He was transferred to an intensive care unit. Laboratory tests showed metabolic acidosis, elevated liver enzymes and acute renal failure. He received volume expansion and was treated by renal replacement therapy and antibiotics. He was intubated and transferred to the operating room. At laparotomy, both colonic necrosis with perforation and necrosis of the small bowel were seen. The patient underwent total colectomy with small bowel resection, distal ileostomy and closure of the rectal stump. The onset of septic and hemorrhagic state required further surgery on June 26th. The evolution was characterized by multi-organ failure with acute anuric renal failure, multiple cardiac arrests, and systemic bacterial and fungal infection. On July 24th, this unfavorable outcome lead to death. In summary, the patient had an occlusive syndrome due to neuroleptics and complications, including mesenteric ischemia with necrotizing colitis. DISCUSSION/CONCLUSION: Quetiapine, like all antipsychotics, has anticholinergic effects, including cardiac, psychiatric and digestive disorders. The combination of anticholinergic drugs decreases intestinal peristalsis. Without any prompt management, this decrease can result in a colonic ischemia or necrosis. In patients treated with neuroleptics, the onset of constipation must alert medical staff. Systematic monitoring of bowel movements should be performed in any patient receiving anticholinergic drugs.

[Fast-tracking and regional anaesthesia: preliminary feasibility study]. / Fast-tracking en anesthésie locorégionale périphérique: étude préliminaire de faisabilité.

OBJECTIVE: The monitoring in the post-anaesthesia care unit (PACU) improves the safety, the comfort and the analgesia of patients. At present, studies suggest the possibility to bypass the PACU according to the principle of fast-tracking (FT). The aim of this study was to evaluate the feasibility and the safety of a simulated protocol of FT after a regional anaesthesia. PATIENTS AND METHODS: Seven hundred patients were prospectively included in this study over a period of 6 months. METHODS: The Withes' scoring system was used for determining when patients could be safely discharged from PACU. We added a variable concerning the monitoring of surgical site. A minimum score of 14 was required on arrival to the PACU to consider a FT. The success rate of blocks, the use of sedation or general anaesthesia were noted. Adverse events were recorded. RESULTS: The success rate of blocks was 93 %. The score was higher than 14 in 98 % of case on arrival to the PACU. Thirteen adverse events were reported before surgery and/or operating room. No adverse events were reported during the stay in the PACU. CONCLUSION: Regional anaesthesia seems to be an appropriate principle to fast-track the PACU. It could be a way to reduce health care costs, and can offer solution for the PACU congestion problem. In France, the fast-tracking is a marginal concept without any support regulatory. An evolution to such a practice could be considered.

Isolation of alkane-degrading bacteria from deep-sea Mediterranean sediments.

AIMS: To isolate and identify alkane-degrading bacteria from deep-sea superficial sediments sampled at a north-western Mediterranean station. METHODS AND RESULTS: Sediments from the water/sediment interface at a 2400 m depth were sampled with a multicorer at the ANTARES site off the French Mediterranean coast and were promptly enriched with Maya crude oil as the sole source of carbon and energy. Alkane-degrading bacteria belonging to the genera Alcanivorax, Pseudomonas, Marinobacter, Rhodococcus and Clavibacter-like were isolated, indicating that the same groups were potentially involved in hydrocarbon biodegradation in deep sea as in coastal waters. CONCLUSIONS: These results confirm that members of Alcanivorax are important obligate alkane degraders in deep-sea environments and coexist with other degrading bacteria inhabiting the deep-subsurface sediment of the Mediterranean. SIGNIFICANCE AND IMPACT OF THE STUDY: The results suggest that the isolates obtained have potential applications in bioremediation strategies in deep-sea environments and highlight the need to identify specific piezophilic hydrocarbon-degrading bacteria (HCB) from these environments.

Influence of Chironomus riparius (Diptera, Chironomidae) and Tubifex tubifex (Annelida, Oligochaeta) on oxygen uptake by sediments. Consequences of uranium contamination.

The diffusive oxygen uptake (DOU) of sediments inhabited by Chironomus riparius and Tubifex tubifex was investigated using a planar oxygen optode device, and complemented by measurements of bioturbation activity. Additional experiments were performed within contaminated sediments to assess the impact of uranium on these processes. After 72h, the two invertebrate species significantly increased the DOU of sediments (13-14%), and no temporal variation occurred afterwards. Within contaminated sediments, it was already 24% higher before the introduction of the organisms, suggesting that uranium modified the sediment biogeochemistry. Although the two species firstly reacted by avoidance of contaminated sediment, they finally colonized it. Their bioturbation activity was reduced but, for T. tubifex, it remained sufficient to induce a release of uranium to the water column and an increase of the DOU (53%). These results highlight the necessity of further investigations to take into account the interactions between bioturbation, microbial metabolism and pollutants.

Imaging oxygen distribution in marine sediments. The importance of bioturbation and sediment heterogeneity.

The influence of sediment oxygen heterogeneity, due to bioturbation, on diffusive oxygen flux was investigated. Laboratory experiments were carried out with 3 macrobenthic species presenting different bioturbation behaviour patterns: the polychaetes Nereis diversicolor and Nereis virens, both constructing ventilated galleries in the sediment column, and the gastropod Cyclope neritea, a burrowing species which does not build any structure. Oxygen two-dimensional distribution in sediments was quantified by means of the optical planar optode technique. Diffusive oxygen fluxes (mean and integrated) and a variability index were calculated on the captured oxygen images. All species increased sediment oxygen heterogeneity compared to the controls without animals. This was particularly noticeable with the polychaetes because of the construction of more or less complex burrows. Integrated diffusive oxygen flux increased with oxygen heterogeneity due to the production of interface available for solute exchanges between overlying water and sediments. This work shows that sediment heterogeneity is an important feature of the control of oxygen exchanges at the sediment-water interface.

Enhanced biodegradation of phenanthrene by a marine bacterium in presence of a synthetic surfactant.

The biodegradation of phenanthrene by the marine strain Sphingomonas sp. 2MPII (DSMZ 11572) was enhanced by the solubilizating properties of the nonionic surfactant Tween 80. After 197 h of incubation, 85 +/- 4% of the initial amount of phenanthrene (0.4 g l-1) was biodegraded in presence of Tween 80 (0.5 g l-1) as opposed to 52 +/- 5% without this synthetic surfactant. These results confirm that the activity of the strain 2MPII is limited by the bioavailability of the polycyclic aromatic hydrocarbon (PAH) substrate in the aqueous phase. Tween 80 appears to be efficient in increasing the bioavailability of hydrophobic compounds such as PAHs.