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Yannay Khaikin, Sarah Sidky, Jose Abdenur, Arnaud Anastasi, Diana Ballhausen, Sabrina Buoni, Alicia Chan, David Cheillan, Nathalie Dorison, Alice Goldenberg, Jennifer Goldstein, Floris C Hofstede, Marie-Line Jacquemont, Dwight D Koeberl, Laurence Lion-Francois, Allan Meldgaard Lund, Karine Mention, Helen Mundy, Declan O'Rourke, Gaele Pitelet, Miquel Raspall-Chaure, Maria Tassini, Thierry Billette de Villemeur, Monique Williams, Gajja S Salomons, Saadet Mercimek-Andrews
PURPOSE: Guanidinoacetate methyltransferase (GAMT) deficiency is an autosomal recessive disorder caused by pathogenic variants in GAMT. Brain creatine depletion and guanidinoacetate accumulation cause developmental delay, seizures and movement disorder. Treatment consists of creatine, ornithine and arginine-restricted diet. We initiated an international treatment registry using Research Electronic Data Capture (REDCap) software to evaluate treatment outcome. METHODS: Physicians completed an online REDCap questionnaire...
February 16, 2018: European Journal of Paediatric Neurology: EJPN
Manisha Juneja, Abdelkrim Azmi, Jonathan Baets, Andreas Roos, Matthew J Jennings, Paola Saveri, Chiara Pisciotta, Nathalie Bernard-Marissal, Bernard L Schneider, Catherine Verfaillie, Roman Chrast, Pavel Seeman, Angelika F Hahn, Peter de Jonghe, Stuart Maudsley, Rita Horvath, Davide Pareyson, Vincent Timmerman
BACKGROUND: Charcot-Marie-Tooth type 2 (CMT2) neuropathy is characterised by a vast clinical and genetic heterogeneity complicating its diagnosis and therapeutic intervention. Identification of molecular signatures that are common to multiple CMT2 subtypes can aid in developing therapeutic strategies and measuring disease outcomes. METHODS: A proteomics-based approach was performed on lymphoblasts from CMT2 patients genetically diagnosed with different gene mutations to identify differentially regulated proteins...
February 15, 2018: Journal of Neurology, Neurosurgery, and Psychiatry
Valdemar Stajer, Milan Vranes, Vladan Kocic, Sergej M Ostojic
PURPOSE: Elevated serum creatine and higher handgrip strength are individually associated with better health profiles yet the link between two variables remains unknown. In this cross-sectional study, we evaluated serum creatine levels in relation to handgrip strength in a cohort of 130 young healthy adults (61 women and 69 men; age 23.3 ± 2.6 years), while controlling for age, gender, fat-free mass and biomarkers of creatine metabolism as effect modifiers. MATERIALS AND METHODS: Serum creatine, creatinine and guanidinoacetic acid (GAA) levels were measured with liquid chromatography-tandem mass spectroscopy, while handgrip strength was assessed with a hydraulic hand dynamometer...
February 6, 2018: Biomarkers: Biochemical Indicators of Exposure, Response, and Susceptibility to Chemicals
Sergej M Ostojic, Jelena Ostojic
We analyzed data from previously completed trials to determine the effects of supplemental guanidinoacetic acid (GAA) on markers of muscle bioenergetics in healthy men using 1.5 T magnetic resonance spectroscopy. No detectable GAA (< 0.1 µM) was found in the vastus medialis muscle at baseline nor at follow-up. This implies deficient GAA availability in the human skeletal muscle, suggesting absent or negligible potential for creatine synthesis from GAA inside this tissue, even after GAA loading.
February 6, 2018: Applied Physiology, Nutrition, and Metabolism, Physiologie Appliquée, Nutrition et Métabolisme
Kenea C Udobi, Amanda N Kokenge, Emily R Hautman, Gabriela Ullio, Julie Coene, Michael T Williams, Charles V Vorhees, Aloïse Mabondzo, Matthew R Skelton
Creatine transporter (CrT; SLC6A8) deficiency (CTD) is an X-linked disorder characterized by severe cognitive deficits, impairments in language, and an absence of brain creatine (Cr). In a previous study, we generated floxed Slc6a8 (Slc6a8flox ) mice to create ubiquitous Slc6a8 knockout (Slc6a8-/y ) mice. Slc6a8-/y mice lacked whole body Cr and exhibited cognitive deficits. While Slc6a8-/y mice have a similar biochemical phenotype to CTD patients, they also showed a reduction in size and reductions in swim speed that may have contributed to the observed deficits...
January 31, 2018: Genes, Brain, and Behavior
Sergej M Ostojic, Milan Vranes, Davor Loncar, Natasa Zenic, Damir Sekulic
Guanidinoacetic acid (GAA) conversion to creatine is thought to be involved in cardiometabolic disturbances through its role in biological methylation and insulin secretion. We evaluated the association of serum GAA and creatine with cardiometabolic risk factors in a cohort of 151 apparently healthy adults (82 women and 69 men) aged 18-63 years. Serum levels of GAA and creatine were measured with liquid chromatography-tandem mass spectrometry. A multiple linear regression model adjusted for age and sex was employed to examine the relationship of serum GAA and creatine with cardiometabolic risk factors...
January 13, 2018: Nutrients
Sergej M Ostojic, Tatjana Trivic, Patrik Drid, Valdemar Stajer, Milan Vranes
No abstract text is available yet for this article.
2018: Annals of Nutrition & Metabolism
Elli Mann, Robert Kluesener, Felix Boschann, Jana Ruppert, Franz P Armbruster, Andreas Meinitzer, Christoph Melzer, Thomas B Dschietzig
BACKGROUND: Homoarginine (hArg) is known to have an impact on nitric oxide (NO) metabolism. It seems to increase NO generation and/or availability, thereby enhancing endothelial function. In addition, hArg is connected to energy metabolism since the key enzyme, L-arginine-glycine amidinotransferase (AGAT) for hArg synthesis in the kidneys, is also involved in the synthesis of energy metabolites like guanidinoacetate. Former studies indicate that low levels of hArg are linked to cardiovascular disease and increased all-cause mortality...
November 1, 2017: Clinical Laboratory
Masanori Tachikawa, Masahiko Watanabe, Masahiro Fukaya, Kazuhisa Sakai, Tetsuya Terasaki, Ken-Ichi Hosoya
Creatine is synthesized by S-adenosylmethionine:guanidinoacetate N-methyltransferase (GAMT), and the creatine/phosphocreatine shuttle system mediated by creatine kinase (CK) is essential for storage and regeneration of high-energy phosphates in cells. Although the importance of this system in brain development is evidenced by the hereditary nature of creatine deficiency syndrome, the spatiotemporal cellular expression patterns of GAMT in developing brain remain unknown. Here we show that two waves of high GAMT expression occur in developing mouse brain...
February 2018: Neurochemical Research
Masanori Tachikawa, Ayane Yashiki, Shin-Ichi Akanuma, Haruka Matsukawa, Soichiro Ide, Masabumi Minami, Ken-Ichi Hosoya
Guanidinoacetate (GAA) is a biosynthetic precursor of creatine, which plays a critical role in homeostasis of high-energy phosphates in the brain, but cerebral accumulation of GAA leads to neurological complications, such as epilepsy and seizures. The purpose of the present study was to clarify the contribution of the γ-aminobutyric acid (GABA) transport systems to GAA transport in astrocytes by means of uptake studies in rat brain slices, primary astrocyte cultures and Chinese hamster ovary (CHO) cells expressing human GABA transporters (GATs)...
February 2018: Neurochemistry International
Ángel Barón-Sola, Francisca Fernández Del Campo, Soledad Sanz-Alférez
Arginine (Arg) and glycine (Gly) seem to be the only substrates accepted by the amidinotransferase that catalyze the first step of the synthesis pathway of the cyanotoxin cylindrospermopsin (CYN), leading to guanidinoacetate (GAA). Here, the effect of these amino acids on the production of CYN in cultures of the cylindrospermopsin-producing strain, Aphanizomenon ovalisporum UAM-MAO, has been studied. Arg clearly increased CYN content, the increment appearing triphasic along the culture. On the contrary, Gly caused a decrease of CYN, observable from the first day on...
November 1, 2017: Toxins
Xiangli Sun, Yanyan Wei, Weiguo Liu, Liying Zhang
A novel ion chromatography method for the determination of guanidinoacetic acid (GAA) in animal feed samples was developed. The optimal detection mode, chromatography column, gradient condition of mobile phases and sample pretreatment conditions were investigated. Using a linear gradient of methane sulfonic acid and ultraviolet detector at 200 nm, the interfering substances in feed samples and GAA could be separated successfully on a Dionex IonPac(TM) CS16 cation exchange analysis column. The calibration curves showed a range of linearity between 0...
October 8, 2017: Se Pu, Chinese Journal of Chromatography
Sergej M Ostojic
Arginine-glycine amidinotransferase (AGAT) deficiency is a rare inherited metabolic disorder that severely affects brain bioenergetics. Characterized by mental retardation, language impairment, and behavioral disorders, AGAT deficiency is a treatable condition, where long-term creatine supplementation usually restores brain creatine levels and improves its clinical features. In some cases of AGAT deficiency, creatine treatment might be somewhat limited due to possible shortcomings in performance and transport of creatine to the brain...
October 3, 2017: Nutritional Neuroscience
Lin Chen, Haifeng Zeng, Xiang Xu, Nirbhay N Yadav, Shuhui Cai, Nicolaas A Puts, Peter B Barker, Tong Li, Robert G Weiss, Peter C M van Zijl, Jiadi Xu
The current study aims to assign and estimate the total creatine (tCr) signal contribution to the Z-spectrum in mouse brain at 11.7 T. Creatine (Cr), phosphocreatine (PCr) and protein phantoms were used to confirm the presence of a guanidinium resonance at this field strength. Wild-type (WT) and knockout mice with guanidinoacetate N-methyltransferase deficiency (GAMT-/-), which have low Cr and PCr concentrations in the brain, were used to assign the tCr contribution to the Z-spectrum. To estimate the total guanidinium concentrations, two pools for the Z-spectrum around 2 ppm were assumed: (i) a Lorentzian function representing the guanidinium chemical exchange saturation transfer (CEST) at 1...
December 2017: NMR in Biomedicine
O Chandani Dinesh, Robert F Bertolo, Janet A Brunton
BACKGROUND: Creatine is not included in commercial pediatric parenteral products; the entire creatine requirement must be met by de novo synthesis from arginine during parenteral nutrition (PN). Poor arginine status is common during PN in neonates which may compromise creatine accretion. We hypothesized that creatine supplementation will improve creatine status and spare arginine in PN-fed piglets. METHODS: Piglets (3-5 d old) were provided PN with or without creatine for 14 d...
August 28, 2017: Pediatric Research
Furhan Iqbal, Herald Hoeger, Gurt Lubec, Olaf Bodamer
The creatine/phosphocreatine system is essential for cellular phosphate coupled energy storage and production. We investigated the utility of creatine monohydrate supplementation in two different creatine deficient knockout mouse models. Following weaning, female Arginine: Glycine Amidinotransferase (AGAT) and Guanidinoacetate: methyltransferase (GAMT) knockouts and wild type mice were studied based on their genotypes and dietary supplementation (creatine free or 2% creatine monohydrate supplemented diet) for 10 weeks, using a series of behavioral tests and biochemical analyzes...
December 2017: Metabolic Brain Disease
Milan Vraneš, Sergej Ostojić, Aleksandar Tot, Snežana Papović, Slobodan Gadžurić
In this work for the first time the physicochemical and thermal properties of guanidinoacetic acid (GAA) and its aqueous solutions have been performed to test for its viability as a potential dietary supplement. Thermal stability, viscosity, solubility and experimental density are determined. From measured densities the volumetric properties were estimated and discussed in the scope of GAA self-aggregation in aqueous solutions using experimental and computational results. Based on thermal stability and solubility measurements, it is found that GAA is more thermally stable but less soluble comparing to creatine due to a self-aggregation process that occurs at GAA concentrations higher than 0...
December 15, 2017: Food Chemistry
Jessie M Cameron, Valeriy Levandovskiy, Wendy Roberts, Evdokia Anagnostou, Stephen Scherer, Alvin Loh, Andreas Schulze
Creatine deficiency syndrome (CDS) comprises three separate enzyme deficiencies with overlapping clinical presentations: arginine:glycine amidinotransferase (GATM gene, glycine amidinotransferase), guanidinoacetate methyltransferase (GAMT gene), and creatine transporter deficiency (SLC6A8 gene, solute carrier family 6 member 8). CDS presents with developmental delays/regression, intellectual disability, speech and language impairment, autistic behaviour, epileptic seizures, treatment-refractory epilepsy, and extrapyramidal movement disorders; symptoms that are also evident in children with autism...
July 31, 2017: International Journal of Molecular Sciences
Duygu Naile Günes, Arslan Arinc Kayacelebi, Erik Hanff, Joel Lundgren, Björn Redfors, Dimitrios Tsikas
L-Homoarginine (hArg) and guanidinoacetate (GAA) are produced from L-arginine (Arg) by the catalytic action of arginine:glycine amidinotransferase. Guanidinoacetate methyltransferase methylates GAA on its non-guanidine N atom to produce creatine. Arg and hArg are converted by nitric oxide synthase (NOS) to nitric oxide (NO). NO is oxidized to nitrite and nitrate which circulate in the blood and are excreted in the urine. Asymmetric dimethylarginine (ADMA), an NOS inhibitor, is widely accepted to be exclusively produced after asymmetric N (G)-methylation of Arg residues in proteins and their regular proteolysis...
July 14, 2017: Amino Acids
Christopher Cartmell, Daniel M Evans, Jessica M L Elwood, Hisham S Fituri, Patrick J Murphy, Thomas Caspari, Barbara Poniedziałek, Piotr Rzymski
Cylindrospermopsin (CYN) is a naturally occurring alkaloid produced by a variety of cyanobacteria and known to induce oxidative stress-mediated toxicity in eukaryotic cells. Despite extensive research on the mechanism of CYN toxicity, an understanding of the structural features responsible for this toxicity and the mechanism by which it can enter the cell are still not clear. It was established that the presence of both the uracil and guanidine groups is essential in biological activity of CYN whilst not much is known in this regard on the role of tether that separates them and the attached hydroxyl group...
October 2017: Toxicology in Vitro: An International Journal Published in Association with BIBRA
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