Soy isoflavones increase preprandial peptide YY (PYY), but have no effect on ghrelin and body weight in healthy postmenopausal women

Background: Soy isoflavones show structural and functional similarities to estradiol. Available data indicate that estradiol and estradiol-like components may interact with gut "satiety hormones" such as peptide YY (PYY) and ghrelin, and thus influence body weight. In a randomized, double-blind, placebo-controlled, cross-over trial with 34 healthy postmenopausal women (59 ± 6 years, BMI: 24.7 ± 2.8 kg/m2), isoflavone-enriched cereal bars (50 mg isoflavones/day; genistein to daidzein ratio 2:1) or non-isoflavone-enriched control bars were consumed for 8 weeks (wash-out period: 8-weeks). Seventeen of the subjects were classified as equol producers. Plasma concentrations of ghrelin and PYY, as well as energy intake and body weight were measured at baseline and after four and eight weeks of each intervention arm. Results: Body weight increased in both treatment periods (isoflavone: 0.40 ± 0.94 kg, P < 0.001; placebo: 0.66 ± 0.87 kg, P = 0.018), with no significant difference between treatments. No significant differences in energy intake were observed (P = 0.634). PYY significantly increased during isoflavone treatment (51 ± 2 pmol/L vs. 55 ± 2 pmol/L), but not during placebo (52 ± 3 pmol/L vs. 50 ± 2 pmol/L), (P = 0.010 for treatment differences, independent of equol production). Baseline plasma ghrelin was significantly lower in equol producers (110 ± 16 pmol/L) than in equol non-producers (162 ± 17 pmol/L; P = 0.025). Conclusion: Soy isoflavone supplementation for eight weeks did not significantly reduce energy intake or body weight, even though plasma PYY increased during isoflavone treatment. Ghrelin remained unaffected by isoflavone treatment. A larger and more rigorous appetite experiment might detect smaller differences in energy intake after isoflavone consumption. However, the results of the present study do not indicate that increased PYY has a major role in the regulation of body weight, at least in healthy postmenopausal women.

Analysis of the headspace aroma compounds of walnuts (Juglans regia L.)

The aroma volatiles of walnuts from three different geographical locations were studied. Over 110 compounds were identified in the headspace volatiles, many for the first time as walnut components. Walnuts from China and the Ukraine contained high levels of lipid-derived volatiles, in particular hexanal, pentanal, 1-hexanol and 1-pentanol from linoleic acid breakdown, and 1-penten-3-ol from alpha-linolenic acid breakdown. Chilean walnuts, however, contained high levels of alkylbenzenes of molecular weight 120, with the lipid-derived aldehydes and alcohols present at much lower levels than in the other two walnut samples. The relationship between the fatty acid composition of the walnuts and their volatile composition is discussed. Copyright (C) 2005 John Wiley & Sons, Ltd.

New prodrugs derived from 6-aminodopamine and 4-aminophenol as candidates for melanocyte-directed enzyme prodrug therapy (MDEPT)

Two novel tyrosinase mediated drug delivery pathways have been investigated for the selective delivery of cytotoxic units to melanocytes from urea and thiourea prodrugs. The synthesis of these prodrugs is reported, as well as oximetry data that illustrate that the targets are substrates for tyrosinase. The stability of each of the prodrugs in (i) phosphate buffer and (ii) bovine serum is discussed, and the urea prodrugs are identified as lead candidates for further studies. Finally, HPLC studies and preliminary cytotoxicity studies in a melanotic and an amelanotic cell line, that illustrate the feasibility of the approach, are presented.

Organocatalysis with proline derivatives: improved catalysts for the asymmetric Mannich, nitro-Michael and aldol reactions

Tetrazole and acylsulfonamide organocatalysts derived from proline have been synthesised and applied to the asymmetric Mannich, nitro-Michael and aldol reactions to give results that are superior to the proline-catalysed counterpart.

Recent highlights in modified oligonucleotide chemistry

The synthesis of modified nucleic acids has been the subject of much study ever since the structure of DNA was elucidated by Watson and Crick at Cambridge and Wilkins and Franklin at King's College over half a century ago. This review describes recent developments in the synthesis and application of these artificial nucleic acids, predominantly the phosphoramidites which allow for easy inclusion into oligonucleotides, and is divided into three separate sections. Firstly, modi. cations to the base portion will be discussed followed secondly by modi. cations to the sugar portion. Finally, changes in the type of nucleic acid linker will be discussed in the third section. Peptide Nucleic Acids ( PNAs) are not discussed in this review as they represent a separate and large area of nucleic acid mimics.

What Monte Carlo models can do and cannot do efficiently?

The question "what Monte Carlo models can do and cannot do efficiently" is discussed for some functional spaces that define the regularity of the input data. Data classes important for practical computations are considered: classes of functions with bounded derivatives and Holder type conditions, as well as Korobov-like spaces. Theoretical performance analysis of some algorithms with unimprovable rate of convergence is given. Estimates of computational complexity of two classes of algorithms - deterministic and randomized for both problems - numerical multidimensional integration and calculation of linear functionals of the solution of a class of integral equations are presented. (c) 2007 Elsevier Inc. All rights reserved.

Design and development of a dextrous manipulator

This paper describes a novel method of actuation for robotic hands. The solution employs a Bowden cable routed to each joint. The use of a Bowden cable is shown to be feasible for this purpose, ever, with the changing frictional forces associated with it. This method greatly simplifies the control of the hand by removing the coupling between joints, and provides for direct and accurate translation between the joints and the servo motors driving the cables. The design also allows for two degrees of freedom with the same centre of rotation to be realized in the largest knuckle of each finger; thus biological finger kinematics are more closely emulated.