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Abstract: Drug resistant malaria is mostly due to Plasmodium falciparum, the highly prevalent species in tropical Africa, Amazon, and Southeast Asia. P. falciparum is responsible for severe involvement of fever or anemia causing more than a million deaths per year. Rationale for treatment is becoming weak as multiple drug resistance against well-tolerated drugs develops. P. falciparum drug resistant malaria originates from chromosomal mutations. Analyses using molecular, genetic and biochemical approaches showed that: 1) impaired uptake of chloroquine by the parasite vacuole is a common characteristic of resistant strains, this phenotype correlates with pfmdr1 and pfcrt gene mutations; 2) one S108N to four (N51I, C59R, I164L) point mutations of dihydrofolate reductase, the enzyme target of antifolinics (pyrimethamine and proguanil), give moderate to high level of resistance to these drugs; 3) resistance to sulfonamides and sulfones involves mutations of dihydropteroate synthase (A437G, K540E), their enzyme target, impairing their capacity to potentiate antifolinic drugs; 4) resistance to atovaquone plus proguanil involves one single mutation on atovaquone target, cytochrome b (Y268S, C or N); 5) resistance to mefloquine is thought to be linked to the over expression of pfmdr1, a pump expelling toxic waste from eukaryotic cells. P. falciparum resistance levels may differ according to places and time, depending on malaria transmission and drug pressure. Coupling in vivo to in vitro tests, and using molecular tests is essential for the surveillance of replacement drugs. Low cost biochemical tools are urgently needed for a prospective monitoring of resistance. [Copyright &y& Elsevier]

• Cellulose nanocrystals are successfully extracted using a natural deep eutectic solvent. • The influence of the treatment time, temperature, and initial fiber concentration during the CNC extraction was studied and thoroughly described using mathematical models. • 16 different parameter combinations are employed to build and to check the validity of these two mathematical models. • Cellulose nanocrystals having optimal yield and crystallinity of 44.9 % and 81 %, respectively, were obtained. In this study, a new approach to optimize the cellulose nanocrystals (CNCs) extraction using acidic natural deep eutectic solvents (NADES) was introduced using, for the first time, design of experiment method. Choline chloride:oxalic acid dihydrate with a molar ratio of 1:1 was used to extract CNCs. Then, three most important parameters were varied to design the experiment: (i) cotton fibre concentrations, (ii) temperature and (iii) treatment time. Two outcomes were studied: the CNC yield and the crystallinity. The mathematical model for crystallinity perfectly described the experiments, while the model for CNC yield provided only a tendency. For a reaction time of 6 h at 95 °C with a fibre concentration of 2 %, the expected optimum CNC yield was approximately 35.5 ± 2.7 % with a crystallinity index of 80 ± 1 %. The obtained experimental results confirmed the models with 43.6 ± 1.9 % and 81 ± 1 % for the CNC yield and the crystallinity index, respectively. This study shows that it is possible to predict the CNC yield CNC and their crystallinity thanks to predictive mathematical models, which gives a great advantage to consider in the near future a scale up of the extraction of cellulose nanocrystals using this original family of green solvents. [ABSTRACT FROM AUTHOR]

Abstract: The surface of model cellulose fibres, Avicell (AV), as well as that of Whatman paper (WP) was chemically modified with two fluorine-bearing alkoxysilane coupling agents, namely: 3,3,3-trifluoropropyl trimethoxysilane (TFPS) and 1H,1H,2H,2H,perfluorooctyl trimethoxysilane (PFOS). The occurrence of the grafting of soxhlet extracted modified cellulose was confirmed by the presence of silicon and fluorine atoms detected by elemental analysis, X-ray photoelectron spectroscopy and Electron Dispersion Energy/Scanning Electron Microscopy (EDS/SEM). The contact angle measurements showed that, after grafting, the surface of AV and WP samples became totally highly hydrophobic with a contact angle of 140°. Thus, the polar contribution to the surface energy of the modified substrates was found to be close to zero. These modified substrate could be interesting for application such as self-cleaning surface, wipes paper, grease barrier paper or for biocomposite with a polar matrix. [Copyright &y& Elsevier]

Cellulose nanocrystals (CNC) and starch nanocrystals (SNC) were grafted by ozone-initiated free-radical polymerisation of styrene in a heterogeneous medium. Surface functionalisation was confirmed by infrared spectroscopy, contact angle measurements, and thermogravimetric and elemental analysis. X-ray diffraction and scanning electron microscopy showed that there was no significant change in the morphology or crystallinity of the nanoparticles following ozonolysis. The grafting efficiency, quantified by 13 C NMR, was greater for SNC, with a styrene/anhydroglucose ratio of 1.56 compared to 0.25 for CNC. The thermal stability improved by 100 °C. The contact angles were 97° and 78° following the SNC and CNC grafting, respectively, demonstrating the efficiency of the grafting in changing the surface properties even at low levels of surface substitution. The grafting increased the compatibility with the polylactide, and produced nanocomposites with improved water vapour barrier properties. Ozone-mediated grafting is thus a promising approach for surface functionalisation of polysaccharide nanocrystals. [ABSTRACT FROM AUTHOR]

Abstract: The objective of the present work is to evaluate the impact of the surface grafting of cellulose fibres on the processing, dimensional stability and mechanical performance of fibre–cement composites. The surface modification of the pulps was performed with methacryloxypropyltri-methoxysilane (MPTS), aminopropyltri-ethoxysilane (APTS) and n-octadecyl isocyanate, an aliphatic isocyanate (AI). X-ray photoelectron spectroscopy (XPS) showed that the chemical changes have indeed occurred at the surface, and contact angle measurements showed that the surface energy has also changed. MPTS- and AI-treated fibres presented lower hydrophilic character than untreated fibres, whereas APTS increased the water retention value of the pulp. MPTS-treated fibres decreased the water retention and improved dimensional stability of the fibre–cement composites, while the contrary occurred with other modified fibres. Fibre–cement strength was little influenced by fibre treatment, whereas AI-treated fibres contributed to higher specific energy (SE) and the lower SE value for APTS-treated fibres is an indication of the improvement on fibre to cement adherence. These results are promising and contribute toward new strategies to improve the processing and stability of natural fibre-reinforced cement products. [Copyright &y& Elsevier]

Abstract: Objectives: To identify independent risk factors of severe falciparum malaria among travelers to endemic regions. Materials and methods: A retrospective study on imported malaria into metropolitan France. The World''s Health Organization severity criteria were used to classify malarial episodes. Results: Nine hundred and twenty-one malarial cases were studied; 81 were severe. Independent risk factors of severe malaria were aged above 40 years, high level of parasitized erythrocytes (more than 4%), parasite acquisition in the south-eastern asian region, infection with a chloroquine resistant Plasmodium falciparum (P. falciparum) phenotype and a self administered antimalarial treatment. Conclusion: This study points out two particularly interesting results: severe malaria is significantly associated with the infection by a chloroquine resistant P. falciparum phenotype and with the parasite''s acquisition in the south-eastern asian region. [Copyright &y& Elsevier]

Résumé: Toxoplasma gondii est responsable d’infections graves après transmission maternofœtale ou chez les sujets immunodéprimés. Plus rarement, des formes sévères avec atteinte viscérale au décours d’une primo-infection toxoplasmique ont été décrites chez le sujet immunocompétent notamment en Guyane Française. Nous rapportons le cas d’un adulte non-VIH et non greffé qui a présenté en France un tableau infectieux sévère non spécifique avec atteinte pulmonaire et cérébroméningée. Le diagnostic de toxoplasmose disséminée a été posé sur un résultat de PCR spécifique de T. gondii positif dans le LCR. La primo-infection a été confirmée par la sérologie. L’histoire de la maladie a été reconstituée à partir des résultats obtenus rétrospectivement par PCR en temps réel sur des sérums et des lavages broncho-alvéolaires. La recherche d’un déficit immunitaire suspecté devant les antécédents médicaux du patient était négative à ce jour. L’évolution a été favorable sous traitement antitoxoplasmique spécifique. [Copyright &y& Elsevier]

Summary: Only few drugs for uncomplicated Plasmodium falciparum malaria are available in children. Atovaquone-proguanil is a recent antimalarial drug licensed in France for the uncomplicated P. falciparum malaria in adults. Few paediatric studies have evaluated atovaquone-proguanil in children for uncomplicated malaria in endemic area, but no study have evaluated this treatment for imported malaria. Objective: To evaluate treatment by atovaquone-proguanil for uncomplicated and imported P. falciparum malaria in children. Methods: We retrospectively evaluated the tolerance and the efficacy of atovaquone-proguanil in the children admitted in Robert-Debré Hospital (Paris) for a P. falciparum malaria. From January 2004 to December 2005, 48 children with a median age of 7,5 years (IQR 4–11) were treated with atovaquone-proguanil for a uncomplicated P. falciparum malaria, except for 5 children who had an isolated hyperparasitemia greater or equal to 5%. Results: Atovaquone-proguanil was stopped for 3/48 children because of vomiting. Fever resolved in all the children between Day 3 and 7, following the beginning of the treatment. One child, with a favourable outcome, had a positive parasitemia at Day 4 equal to the initial parasitemia (0,1%). No late therapeutic failure was observed among the 24 children evaluated up to one month after starting treatment. Conclusion: Atovaquone-proguanil is an efficient and well-tolerated antimalarial treatment for uncomplicated P. falciparum malaria in children. The risk of vomiting should lead to a systematic initial hospitalisation of children treated with atovaquone-proguanil. [Copyright &y& Elsevier]

A shared genetic susceptibility between cutaneous malignant melanoma (CMM) and Parkinson's disease (PD) has been suggested. We investigated this by assessing the contribution of rare variants in genes involved in CMM to PD risk. We studied rare variation across 29 CMM risk genes using high-quality genotype data in 6875 PD cases and 6065 controls and sought to replicate findings using whole-exome sequencing data from a second independent cohort totaling 1255 PD cases and 473 controls. No statistically significant enrichment of rare variants across all genes, per gene, or for any individual variant was detected in either cohort. There were nonsignificant trends toward different carrier frequencies between PD cases and controls, under different inheritance models, in the following CMM risk genes: BAP1 , DCC , ERBB4, KIT , MAPK2 , MITF , PTEN , and TP53 . The very rare TYR p.V275F variant, which is a pathogenic allele for recessive albinism, was more common in PD cases than controls in 3 independent cohorts. Tyrosinase, encoded by TYR, is the rate-limiting enzyme for the production of neuromelanin, and has a role in the production of dopamine. These results suggest a possible role for another gene in the dopamine-biosynthetic pathway in susceptibility to neurodegenerative Parkinsonism, but further studies in larger PD cohorts are needed to accurately determine the role of these genes/variants in disease pathogenesis. [ABSTRACT FROM AUTHOR]