Enzymology of the branched-chain amino acid oxidation disorders: the valine pathway

Valine is one of the three branched-chain amino acids which undergoes oxidation within mitochondria. In this paper, we describe the current state of knowledge with respect to the enzymology of the valine oxidation pathway and the different disorders affecting oxidation

Effect of creatine supplementation during resistance training on lean tissue mass and muscular strength in older adults: a meta-analysis

Philip D Chilibeck,1 Mojtaba Kaviani,2 Darren G Candow,3 Gordon A Zello4 1College of Kinesiology, University of Saskatchewan, Saskatoon, SK, 2School of Nutrition and Dietetics, Acadia University, Wolfville, NS, 3Faculty of Kinesiology and Health Studies, University of Regina, Regina, 4College of Pharmacy and Nutrition, University of Saskatchewan, Saskatoon, SK, Canada Abstract: The loss of muscle mass and strength with aging results in significant functional impairment. Creatine supplementation has been used in combination with resistance training as a strategy for increasing lean tissue mass and muscle strength in older adults, but results across studies are equivocal. We conducted a systematic review and meta-analysis of randomized controlled trials of creatine supplementation during resistance training in older adults with lean tissue mass, chest press strength, and leg press strength as outcomes by searching PubMed and SPORTDiscus databases. Twenty-two studies were included in our meta-analysis with 721 participants (both men and women; with a mean age of 57–70 years across studies) randomized to creatine supplementation or placebo during resistance training 2–3 days/week for 7–52 weeks. Creatine supplementation resulted in greater increases in lean tissue mass (mean difference =1.37 kg [95% CI =0.97–1.76]; p<0.00001), chest press strength (standardized mean difference [SMD] =0.35 [0.16–0.53]; p=0.0002), and leg press strength (SMD =0.24 [0.05–0.43]; p=0.01). A number of mechanisms exist by which creatine may increase lean tissue mass and muscular strength. These are included in a narrative review in the discussion section of this article. In summary, creatine supplementation increases lean tissue mass and upper and lower body muscular strength during resistance training of older adults, but potential mechanisms by which creatine exerts these positive effects have yet to be evaluated extensively. Keywords: muscle, age, sarcopenia, exercise, nutrition, bench press, leg pres

Cytotoxic 4'-aminochalcones and related compounds

A series of 4'-aminochalcones 1 and related maleamic acids 2 and Schiff bases 3 were designed and synthesized as candidate cytotoxic agents. The atomic charges on different atoms of representative compounds were calculated. Evaluation of the enones 1-3 against human Molt 4/C8 and CEM T-lymphocytes as well as murine P388 and L1210 leukemic cells revealed that approximately 40% of the IC50 values generated were less than 10 microM. In some cases cytotoxicity was correlated with the Hammett sigma values of the aryl substituents and less frequently with the aryl Hansch pi values. Evidence was obtained that in general these compounds displayed selective toxicity for certain malignant cells and were well tolerated in mice. This study has revealed various directions whereby the project may be amplified in the future with a view to finding compounds with increased cytotoxicity to tumour cells.status: publishe