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Biomedical subjects

D Robert

Publications and source records attributed to D Robert.

At least 19 recordsLinked to original sources
PubMed2006

The effect of landfill leachate composition on organics and nitrogen removal in an activated sludge system with bentonite additive.

A pre-denitrification activated sludge system (AS) without internal recycle was used in lab-scale studies of landfill leachate treatment. A bentonite supplement at a ratio of 1:4 (mineral : biomass) was used to ensure high sludge settling levels and to serve as a micro-organisms carrier. The system was operated within different parameters such as hydraulic retention time (HRT), ammonia loading rate (ALR) or external recycle ratio, which was adapted to treat varying leachate concentrations of COD and ammonia, ranging from 1020 to 2680 mgO(2)l(-1) and 400-890 mgNH(4)-Nl(-1) respectively. The nitrification was complete and ammonia oxidation reached 99%; this was obtained while the ALR did not exceed 0.09 g NH(4)(+)-Ng(-1)MLVSS d(-1) and HRT was not lower than 1 day (in the aeration reactor). The performance of denitrification was successfully improved by controlling the external recycle rate, when the BOD(5)/N ratio in the raw leachate was 4.1. Consequently, N-removal of up to 80% was achieved. A 10-fold decrease in the denitrification rate was obtained at a BOD(5)/N ratio of 0.5. The efficiency of COD removal varied significantly from 36% to 84%. The positive effect of bentonite addition was determined and is discussed based on preliminary studies. The experiments were carried out in fill-and-draw activated sludge with bentonite; the biomass ratio was 1:2. The activated sludge with bentonite was fed with a synthetic high ammonia and organic-free medium.

Bentonite↗
PubMed2006

[Clinical, microbiological, and therapeutic aspects of Nocardia sp. infections in the Bordeaux hospital from 1993 to 2003].

OBJECTIVE: Our goal was to describe the epidemiological, clinical, and microbiological characteristics of nocardiosis in the Bordeaux teaching hospital, between January 1, 1993 and December 31, 2003. DESIGNS: The retrospective study included patients examined between January 1, 1993 and December 31, 2003 in whom a Nocardia bacterium had been identified from a biological sample. RESULTS: Twenty-four out of 30 Nocardia sp. strains identified during the study period were classified as colonizing strains. 19 patients presented with risk factors for nocardiosis. Nocardia asteroïdes were found in 22 samples, mainly from pulmonary samples. 11 cases of infection due to Nocardia sp. were reported during the study period. Immunosuppression was reported in 7 cases. The clinical forms were not specific. The species incriminated belonged to the N. asteroïdes complex in 8 cases. Treatment consisted in a combination of 2 or 3 molecules including cotrimoxazole for an average duration of 9 months. 9 patients recovered. CONCLUSIONS: The variability of clinical presentation and the lack of standard identification methods delayed the diagnostic. The treatment is not well defined. Clinical strains should be reported to the reference laboratory and prospective studies are necessary.

Anti-Bacterial Agents↗
PubMed2006

[Human herpesvirus 6 encephalitis in trimethoprim-sulfamethoxazole-induced hypersensitivity syndrome].

INTRODUCTION: Human herpesvirus 6 (HHV-6), the causative agent of the common exanthem subitum, is a known cause of central nervous system infection in immunocompromised patients. It has been suggested that HHV-6 participate in the development of drug-induced hypersensitivity syndrome. CASE REPORT: We reported a case of HHV-6 encephalitis associated with hypersensitivity syndrome induced by trimethoprim-sulfamethoxazole in a 72-year-old HIV-negative woman. DISCUSSION: Our case confirmed that reactivation of HHV-6 infection may contribute to the development of the hypersensitivity syndrome.

Aged↗
PubMed2006

Loading dose of vancomycin in critically ill patients: 15 mg/kg is a better choice than 500 mg.

Delays in antimicrobial therapy in high-risk patients with infection may have deleterious effects on clinical outcomes. Therefore, appropriate treatment must be initiated promptly. The objective of this prospective study was to determine the better loading dose of vancomycin in critically ill patients with suspected Gram-positive infections. Two groups of patients were studied successively: Group A, loading dose of 500 mg; and Group B, loading dose of 15 mg/kg. The mean post-loading dose serum vancomycin concentration was significantly higher in Group B than in Group A (19.1 +/- 7.4 mg/L versus 10.4 +/- 2.7 mg/L; P < 0.001), without producing toxic peak levels. Clinical cure rates were significantly different for infected patients in Group B compared with Group A: 93% (14 of 15 patients) versus 56% (10 of 18 patients), respectively. However, the proportion of patients surviving to Intensive Care Unit discharge was similar. Because vancomycin is believed to achieve maximum killing at concentrations in serum of four to five times the minimum inhibitory concentration for the infecting organism, our results suggest that the 15 mg/kg loading dose should be preferred.

Aged↗
PubMed2006

Necrotizing gastritis due to Bacillus cereus in an immunocompromised patient.

Bacillus cereus is increasingly being acknowledged as a serious bacterial pathogen in immunocompromised patients. We present a case of acute necrotizing gastritis caused by B. cereus in a 37-year-old woman with acute myeloblastic leukemia, who recovered following total parenteral nutrition and treatment with imipenem and vancomycin. B. cereus was isolated from gastric mucosa and blood cultures. Up to now, no case of acute necrotizing gastritis due to this organism has been reported.

Adult↗
PubMed2006

[Assessment of dysarthria and dysphagia in ALS patients].

Swallowing and speech disorders are the dramatic consequences of bulbar and pseudo-bulbar syndrome in ALS. Evaluation is necessary to guide speech therapy and to measure the effects of treatment. This article revues the different examinations used to assess bulbar and pseudobulbar involvement in an ALS patient: oromotor assessment, evaluation of the functions with self assessment, perceptive and objective evaluation of speech disorders, fiberoptic endoscopic evaluation of dysphagia (FEES) and videofluoroscopy.

Amyotrophic Lateral Sclerosis↗
PubMed2006

Leachate detoxification by combination of biological and TiO2-photocatalytic processes.

Landfill leachates are a problematic wastewater due to their variable concentration, volume changing in time and presence of refractory and hazardous components. In this paper, the results of a new approach to photocatalysis assisted by biological process for the detoxification of stabilised landfill leachate are presented. The biologically pre-treated leachate still contained a significant amount of non-biodegradable COD and TOC amounting to 500 and 200 mg/L, respectively. The 300 min of photocatalytic treatment (UVC/TiO2) brought about a significant decrease in more than 80% refractory organics remaining in leachate. The effect of pH and catalyst loading on mineralisation, colour removal rate and biodegradability (BOD/COD) improvement in the photoreactor were discussed. The bio-accessibility of formed photocatalytic oxidation intermediates was confirmed by oxygen uptake rate (OUR) measurements. Consequently, a part of COD was successfully removed in post-biological treatment.

Biodegradation, Environmental↗
PubMed2005

Patterns of home mechanical ventilation use in Europe: results from the Eurovent survey.

The study was designed to assess the patterns of use of home mechanical ventilation (HMV) for patients with chronic respiratory failure across Europe. A detailed questionnaire of centre details, HMV user characteristics and equipment choices was sent to carefully identified HMV centres in 16 European countries. A total of 483 centres treating 27,118 HMV users were identified. Of these, 329 centres completed surveys between July 2001 and June 2002, representing up to 21,526 HMV users and a response rate of between 62% and 79%. The estimated prevalence of HMV in Europe was 6.6 per 100,000 people. The variation in prevalence between countries was only partially related to the median year of starting HMV services. In addition, there were marked differences between countries in the relative proportions of lung and neuromuscular patients using HMV, and the use of tracheostomies in lung and neuromuscular HMV users. Lung users were linked to a HMV duration of <1 yr, thoracic cage users with 6-10 yrs of ventilation and neuromuscular users with a duration of > or =6 yrs. In conclusion, wide variations exist in the patterns of home mechanical ventilation provision throughout Europe. Further work is needed to monitor its use and ensure equality of provision and access.

Adolescent↗
PubMed2005

Quality control of equipment in home mechanical ventilation: a European survey.

Quality control of the equipment used in home mechanical ventilation is necessary in order to ensure that patients safely and accurately receive the prescribed ventilatory support. The aim of this study was to carry out a survey on the quality-control procedures in different centres and countries. The survey was carried out in the context of a European Commission Concerted Action covering 16 European countries. The study was extensive and detailed, involving 326 centres, which provided home ventilation to >20,000 patients. The survey showed that: 1) ventilator servicing was mainly carried out by external companies (62% of centres), with a servicing frequency ranging 3-12 months; 2) interaction between servicing companies and prescribers was limited (only 61% of centres were always informed of major incidents); 3) participation of centres in equipment quality control was poor (only 56% of centres assessed that patients/caregivers correctly cleaned/maintained the ventilator); and 4) centres were insufficiently aware of vigilance systems (only 23% of centres). Moreover, the data showed considerable inter- and intra-country differences. The size of the centre was an important determinant of many of these quality-control aspects. This survey provides information that will enable the European Commission Concerted Action to formulate recommendations on procedures for home-ventilator quality control.

Chronic Disease↗
PubMed2004

Power gain exhibited by motile mechanosensory neurons in Drosophila ears.

In insects and vertebrates alike, hearing is assisted by the motility of mechanosensory cells. Much like pushing a swing augments its swing, this cellular motility is thought to actively augment vibrations inside the ear, thus amplifying the ear's mechanical input. Power gain is the hallmark of such active amplification, yet whether and how much energy motile mechanosensory cells contribute within intact auditory systems has remained uncertain. Here, we assess the mechanical energy provided by motile mechanosensory neurons in the antennal hearing organs of Drosophila melanogaster by analyzing the fluctuations of the sound receiver to which these neurons connect. By using dead WT flies and live mutants (tilB(2), btv(5P1), and nompA(2)) with defective neurons as a background, we show that the intact, motile neurons do exhibit power gain. In WT flies, the neurons lift the receiver's mean total energy by 19 zJ, which corresponds to 4.6 times the energy of the receiver's Brownian motion. Larger energy contributions (200 zJ) associate with self-sustained oscillations, suggesting that the neurons adjust their energy expenditure to optimize the receiver's sensitivity to sound. We conclude that motile mechanosensory cells provide active amplification; in Drosophila, mechanical energy contributed by these cells boosts the vibrations that enter the ear.

Animals↗