Neuropsychological and psychosocial effects of the FMR-1 full mutation: Case report of monozygotic twins discordant for the fragile X syndrome.

An extensive evaluation was conducted with 16-yr-old monozygotic twins concordant for the fragile X full mutation but discordant for mental retardation. The clearly affected twin had an IQ score of 47; 77% of her neuropsychological z scores were at least 2 SDs below average. Her sister had an IQ score of 105 and average neuropsychological performance. However, each girl demonstrated relative verbal strengths and visual-spatial weaknesses. Their parents rated each girl as having significant problems with attention, conduct, anxiety-withdrawal, and hyperactivity. The girls did not rate themselves as having significant anxiety. These findings are consistent with group data on females with fragile X and demonstrate the wide range of effects associated with the fragile X full mutation. This case report implicates the importance of a psychosocial phenotype of fragile X independent of cognitive ability level. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Radical‐scavenging properties of extracts from the white button mushroom,Agaricus bisporus

BACKGROUND: Agaricus bisporus is the premier cultivated edible mushroom but is usually considered to be of lesser value nutritionally and medicinally compared with other cultivated mushrooms. The objective of this study was to investigate the radical‐scavenging properties of methanolic extracts and the free radical‐processing enzyme activities of water extracts from A. bisporus fruit bodies. Analyses were performed on total fruit bodies from three strains and on separated stipe, cap and gills from one strain, all cultivated experimentally under the same conditions. RESULTS: EC₅₀ values of scavenging ability on 1,1‐diphenyl‐2‐picrylhydrazyl radicals (DPPH^?), scavenging ability on 2,2‐azino‐bis(3‐ethylbenzothiazoline‐6‐sulfonic acid) radical cations (ABTS^?+) and reducing power of methanolic extracts from total fruit bodies ranged between 1.7 and 5.0 and were 1.1–1.9 times higher in a white hybrid than in two wild strains, cream and brown. The gills exhibited higher antioxidant activities relative to the stipe and cap. In water extracts, glutathione peroxidase activities were up to eight times higher than glutathione reductase activities and no difference was observed between strains. Catalase activity was highest in the brown wild strain. The only significant differences in free radical‐processing enzymes between the three parts of the mushroom were higher catalase activity in the gills and lower glutathione reductase activity in the stipe. CONCLUSION: The radical‐scavenging properties of the button mushroom are comparable to those of other edible mushrooms and dependent on the strain and on the section of the fruit body. Copyright © 2008 Society of Chemical Industry     

Strength of pure alumina ceramics above 1 GPa

Up to now, commercially available alumina ceramics were claimed to have strength between 400 and 550 MPa. However, our study shows strength ~ 2 times higher for commercially available alumina than commonly believed. The average and characteristic strength, measured on 31 pure alumina ceramic discs by ball on three balls (B3B) test, were 1205 ± 93 MPa and 1257 MPa, respectively, with a Weibull modulus of m = 11.8. Tested specimens were in form of discs with a diameter of 5 mm and thickness 0.5 mm. The grain size distribution of the alumina is bimodal with an average grain size of ~ 850 nm measured at the surface. The fracture reveals a mixed transgranular / intergranular failure mode. To avoid incorporation of additional flaws, the discs were tested as sintered. The characteristic flexural strength measured in B3B was recalculated according to Weibull theory for standard 4-point bending bars of size 3 × 4 × 45 mm as bend 856 MPa. The measured strength of nearly 900 MPa shows the potential of strength for high purity alumina ceramics.     

Production of 2,3-butanediol from diverse saccharides via fermentation

The present study aimed to evaluate the potential use of whey to produce 2,3-BD via the fermentation of lactose and its monosaccharides, glucose and galactose, in a synthetic culture medium (medium 9, M9) using a modified strain of Escherichia coli K12 MG1655 (E. coli JFR12) at a 0.1 L/L (10 vol%) inoculum ratio, 37 °C, atmospheric pressure, an initial pH 7.4, and 100 rpm for 72 h varying the saccharide concentration from 12.5, 25, and 50 g/L. The 2,3-BD yield was ∼80 % of the theoretical yield using 25 g/L of glucose and lactose, corresponding to 0.38 g/g saccharides at a fermentation time of 48 h (glucose) and 72 h (lactose). However, the 2,3-BD yield was halved (0.19 g/g galactose), fermenting 25 g/L of galactose at 48 h. Taking into account these results, two important conclusions were determined: i) E. coli JFR12 could transform galactose into 2,3-BD although its yield was half of the yield observed with glucose at 48 h; and ii) E. coli JFR12 was as efficient as other natural 2,3-BD producers such as Klebsiella species fermenting lactose. However, the E. coli strain has the advantage of being an innocuous strain. To the best of our knowledge, there is no other study presenting the production of 2,3-BD from galactose and lactose with a genetically modified E. coli strain.     

Synthesis of semiconducting polyphenylacetylene catalyzed by Ni(MeCN)6(BF4)2/AlEt2Cl

Summary Phenylacetylene (PhA) is polymerized by the dicationic nickel complex Ni(MeCN)₆(BF₄)₂ associated with AlEt₂Cl as co-catalyst. The production of 200g of polymer per gram of nickel per hour represents a typical activity of this system. Under our experimental conditions, the polymer displays an exclusive trans structure. The molecular weight distribution of the polymer is polymodal (5000 g.mol⁻¹ and 200 g.mol⁻¹). The highest average molecular weight fraction (5000 g. mol⁻¹) represents the highest published value for polyphenylacetylene (PPA) where a nickel catalyst is employed. The electrical conductivities vary between 10⁻⁷ and 10⁻¹⁶ S.cm⁻¹, and are characteristic of a semi-conductor polymer. Equivalent values are cited in the literature only in the case of doped PPA. Experimental observations enabled us to propose a mechanism for the formation of the active species through the reaction of Ni(MeCN)₆(BF₄)₂ with AlEt₂Cl. Received: 13 September 2001/Revised version: 10 January 2002/ Accepted: 11 January 2002     

Tamoxifen derivatives for delivery of the antitumoral (DACH)Pt group: selective synthesis by McMurry coupling,and biochemical behaviour

The goal of our study was to potentiate the effects of the ((R,R)-trans-1,2-diaminocyclohexane)-platinum(II) fragment [(DACH)Pt], known for its cytotoxic properties, either with tamoxifen (Tam), the most widely used antiestrogen in the treatment of hormone-dependent breast cancers, or with its active metabolite hydroxytamoxifen (hydroxy-Tam). We coupled Tam or hydroxy-Tam derivatives bearing a malonato group at the para position of the beta aromatic ring with the (DACH)Pt fragment. The malonato-Tam and malonato-hydroxy-Tam compounds were prepared through McMurry coupling of the appropriate ketones. The presence of the malonate group resulted in a pronounced stereospecificity in the reaction, since malonato-Tam was obtained only as the Z isomer, while malonato-hydroxy-Tam was obtained as an 80/20 E/Z mixture. Attribution of the isomeric structures was achieved by 2D NMR spectroscopy. The platinum complexes (DACH)Pt-malonato-Tam and (DACH)Pt-malonato-hydroxy-Tam were then prepared by coupling the barium salts derived from the malonato-Tam and malonato-hydroxy-Tam with the nitrate derived from (DACH)PtCl(2). Study of the biochemical properties of these two platinum complexes showed that, while the hydroxy-Tam complex is satisfactorily recognized by the estrogen receptor (relative binding affinity, RBA=6.4 %), the Tam complex is less well recognized (RBA=0.5 %). The effects of these complexes on two hormone-dependent breast cancer cell lines (MCF7 and MVLN) were studied in vitro. Both complexes showed an antiproliferative effect on MCF7 cells, and an antiestrogenic effect on MVLN cells. The observed effects appear to be essentially antihormonal, since incorporation of the (DACH)Pt fragment into the tamoxifen skeleton did not cause an increase in the cytotoxicity of the complexes.     

Diastereoselective Heterogeneous Catalytic Hydrogenation of Aromatic or Heteraromatic Compounds

The diastereoselective hydrogenation catalyzed by heterogeneous metallic catalysts uses a covalently bound chiral auxiliary to induce the chirality. It remains an active synthetic methodology in the asymmetric synthesis of chiral products and may proceed with high diastereoselectivity. This review describes recent examples using this method, such as hydrogenation of C=C, C=O, and C=N bonds. The use of a chiral auxiliary group has also been successfully applied to the hydrogenation of aromatic and heteroaromatic rings. The choice of the chiral auxiliary was found to play a key role in the asymmetric hydrogenation. The results could be explained in terms of steric effect, with a preferred conformation of the adduct substrate and the addition occurring from the less bulky side. The catalytic metal, the support and the presence of additives were also found to have a significant influence.     

Solution- and crystal-phase covalent modification of lysozyme by a purpose-designed organoruthenium complex. A MALDI-TOF MS study of its metal binding sites

Study of the reaction between the transition organometallic complex 4-ruthenocenyl 2,6-dimethylpyrylium tetrafluoroborate and the enzyme hen egg white lysozyme (HEWL) in solution and by diffusion in crystals was performed by use of a combination of spectroscopic and chromatographic methods. Conjugation involving the lysine residues of lysozyme appeared to occur readily, yielding very stable ruthenocenyl pyridinium adducts with average degrees of incorporation ranging from 0.2 to 1.8 metal complexes per protein molecule, depending on reaction conditions. Matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS) revealed that the protein conjugates were in fact mixtures of unmodified, mono-, di- and sometimes tripyridinium adducts. In combination with reversed-phased HPLC, we were able to show that six different monoruthenocenyl pyridinium adducts were formed in solution. This result was confirmed by trypsin digestion of a ruthenocenyl pyridinium conjugate and MALDI-TOF MS analysis of the peptide mixture, which showed that lysines 1, 13, 33, 96, 97 and 116 were involved in the reaction with the pyrylium complex, lysines 13, 33 and 116 being the major binding sites. In the tetragonal crystal state, no binding of the ruthenium complex was shown to occur at lysine 116, owing to steric hindrance at this particular position.