Augmentation of Creatine in the Heart.

Science.gov (United States)

Zervou, Sevasti; Whittington, Hannah J; Russell, Angela J; Lygate, Craig A

2016-01-01

Creatine is a principle component of the creatine kinase (CK) phosphagen system common to all vertebrates. It is found in excitable cells, such as cardiomyocytes, where it plays an important role in the buffering and transport of chemical energy to ensure that supply meets the dynamic demands of the heart. Multiple components of the CK system, including intracellular creatine levels, are reduced in heart failure, while ischaemia and hypoxia represent acute crises of energy provision. Elevation of myocardial creatine levels has therefore been suggested as potentially beneficial, however, achieving this goal is not trivial. This mini-review outlines the evidence in support of creatine elevation and critically examines the pharmacological approaches that are currently available. In particular, dietary creatine-supplementation does not sufficiently elevate creatine levels in the heart due to subsequent down-regulation of the plasma membrane creatine transporter (CrT). Attempts to increase passive diffusion and bypass the CrT, e.g. via creatine esters, have yet to be tested in the heart. However, studies in mice with genetic overexpression of the CrT demonstrate proof-of-principle that elevated creatine protects the heart from ischaemia-reperfusion injury. This suggests activation of the CrT as a major unmet pharmacological target. However, translation of this finding to the clinic will require a greater understanding of CrT regulation in health and disease and the development of small molecule activators.

Creatine and creatine forms intended for sports nutrition.

Science.gov (United States)

Andres, Susanne; Ziegenhagen, Rainer; Trefflich, Iris; Pevny, Sophie; Schultrich, Katharina; Braun, Hans; Schänzer, Wilhelm; Hirsch-Ernst, Karen Ildico; Schäfer, Bernd; Lampen, Alfonso

2017-06-01

Creatine is a popular ergogenic supplement in sports nutrition. Yet, supplementation of creatine occasionally caused adverse effects such as gastrointestinal complaints, muscle cramps and an increase in body weight. Creatine monohydrate has already been evaluated by different competent authorities and several have come to the conclusion that a daily intake of 3 g creatine per person is unlikely to pose safety concerns, focusing on healthy adults with exclusion of pregnant and breastfeeding women. Possible vulnerable subgroups were also discussed in relation to the safety of creatine. The present review provides an up-to-date overview of the relevant information with special focus on human studies regarding the safety of creatine monohydrate and other marketed creatine forms, in particular creatine pyruvate, creatine citrate, creatine malate, creatine taurinate, creatine phosphate, creatine orotate, creatine ethyl ester, creatine pyroglutamate, creatine gluconate, and magnesium creatine chelate. Limited data are available with regard to the safety of the latter creatine forms. Considering an acceptable creatine intake of 3 g per day, most of the evaluated creatine forms are unlikely to pose safety concerns, however some safety concerns regarding a supplementary intake of creatine orotate, creatine phosphate, and magnesium creatine chelate are discussed here. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Creatine kinase response to high-intensity aerobic exercise in adult-onset muscular dystrophy

DEFF Research Database (Denmark)

Andersen, Søren P; Sveen, Marie-Louise; Hansen, Regitze S

2013-01-01

We investigated the effect of high-intensity exercise on plasma creatine kinase (CK) in patients with muscular dystrophies.......We investigated the effect of high-intensity exercise on plasma creatine kinase (CK) in patients with muscular dystrophies....

Response of plasma and urinary uric acid, creatine and creatinine to dietary protein deficiency and/or whole body gamma-irradiation in desert rodent and albino rats

Energy Technology Data Exchange (ETDEWEB)

Roushdy, H M; El-Husseini, M; Saleh, F [National Centre for Radiation Research and Technology, Cairo (Egypt)

1985-01-01

The effect of whole body gamma-irradiation on the levels of plasma and urinary uric acid, creatine and creatinine was studied in the desert rodent, Psammomys obesus and albino rats subjected to dietary protein deficiency. In albino rats, the levels of uric acid in plasma and urine were higher in the animals kept on high protein diets than in those maintained on non-protein ones. Radiation exposure caused a significant increase in uric acid concentration both in plasma and urine of albino rats, whereas in Psammomys obesus obesus, it exerted a significant drop in uric acid concentration in blood paralleling a marked rise in the daily uric acid excretion in the urine, especially with the high radiation level of 1170 r. Creatinine concentrations in plasma and urine of albino rats were higher than the corresponding values in Psammomys obesus obesus. Radiation exposure in general caused an increase in the creatinine concentration in blood and a decrease in its concentration in urine. Plasma creatine was shown to increase due to the effect of radiation exposure. This runs in parallel with the increase in the excretion of creatine in urine. Creatinuria observed in whole body irradiation is obviously caused by a defect in the ability of skeletal muscle to take up creatine from blood. Such abnormality could be the result of direct damage to the muscle caused by incident radiation.

Response of plasma and urinary uric acid, creatine and creatinine to dietary protein deficiency and/or whole body gamma-irradiation in desert rodent and albino rats

International Nuclear Information System (INIS)

Roushdy, H.M.; El-Husseini, M.; Saleh, F.

1985-01-01

The effect of whole body gamma-irradiation on the levels of plasma and urinary uric acid, creatine and creatinine was studied in the desert rodent, Psammomys obesus and albino rats subjected to dietary protein deficiency. In albino rats, the levels of uric acid in plasma and urine were higher in the animals kept on high protein diets than in those maintained on non-protein ones. Radiation exposure caused a significant increase in uric acid concentration both in plasma and urine of albino rats, whereas in Psammomys obesus obesus, it exerted a significant drop in uric acid concentration in blood paralleling a marked rise in the daily uric acid excretion in the urine, especially with the high radiation level of 1170 r. Creatinine concentrations in plasma and urine of albino rats were higher than the corresponding values in Psammomys obesus obesus. Radiation exposure in general caused an increase in the creatinine concentration in blood and a decrease in its concentration in urine. Plasma creatine was shown to increase due to the effect of radiation exposure. This runs in parallel with the increase in the excretion of creatine in urine. Creatinuria observed in whole body irradiation is obviously caused by a defect in the ability of skeletal muscle to take up creatine from blood. Such abnormality could be the result of direct damage to the muscle caused by incident radiation

A reversed-field theta-pinch plasma machine

International Nuclear Information System (INIS)

Yasojima, Yoshiyuki; Ueda, Yoshihiro; Sasao, Hiroyuki; Ueno, Noboru; Tanaka, Toshihide

1984-01-01

Mitsubishi Electric has constructed a reversed-field theta-pinch machine at its Central Research Laboratory and initiated a series of plasma diagnostics and control studies for development of nuclear-fusion technology. Although the device has a linear configuration, a stable high-temperature, high-density toroidal plasma can be generated. The article describes the overall structure, vacuum system, power-supply system, and diagnostics and control system of the plasma machine. (author)

Creatine biosynthesis and transport in health and disease.

Science.gov (United States)

Joncquel-Chevalier Curt, Marie; Voicu, Pia-Manuela; Fontaine, Monique; Dessein, Anne-Frédérique; Porchet, Nicole; Mention-Mulliez, Karine; Dobbelaere, Dries; Soto-Ares, Gustavo; Cheillan, David; Vamecq, Joseph

2015-12-01

Creatine is physiologically provided equally by diet and by endogenous synthesis from arginine and glycine with successive involvements of arginine glycine amidinotransferase [AGAT] and guanidinoacetate methyl transferase [GAMT]. A specific plasma membrane transporter, creatine transporter [CRTR] (SLC6A8), further enables cells to incorporate creatine and through uptake of its precursor, guanidinoacetate, also directly contributes to creatine biosynthesis. Breakthrough in the role of creatine has arisen from studies on creatine deficiency disorders. Primary creatine disorders are inherited as autosomal recessive (mutations affecting GATM [for glycine-amidinotransferase, mitochondrial]) and GAMT genes) or X-linked (SLC6A8 gene) traits. They have highlighted the role of creatine in brain functions altered in patients (global developmental delay, intellectual disability, behavioral disorders). Creatine modulates GABAergic and glutamatergic cerebral pathways, presynaptic CRTR (SLC6A8) ensuring re-uptake of synaptic creatine. Secondary creatine disorders, addressing other genes, have stressed the extraordinary imbrication of creatine metabolism with many other cellular pathways. This high dependence on multiple pathways supports creatine as a cellular sensor, to cell methylation and energy status. Creatine biosynthesis consumes 40% of methyl groups produced as S-adenosylmethionine, and creatine uptake is controlled by AMP activated protein kinase, a ubiquitous sensor of energy depletion. Today, creatine is considered as a potential sensor of cell methylation and energy status, a neurotransmitter influencing key (GABAergic and glutamatergic) CNS neurotransmission, therapeutic agent with anaplerotic properties (towards creatine kinases [creatine-creatine phosphate cycle] and creatine neurotransmission), energetic and antioxidant compound (benefits in degenerative diseases through protection against energy depletion and oxidant species) with osmolyte behavior (retention of

Does creatine supplementation improve the plasma lipid profile in healthy male subjects undergoing aerobic training?

Directory of Open Access Journals (Sweden)

Scagliusi Fernanda B

2008-10-01

Full Text Available Abstract We aimed to investigate the effects of creatine (Cr supplementation on the plasma lipid profile in sedentary male subjects undergoing aerobic training. Methods Subjects (n = 22 were randomly divided into two groups and were allocated to receive treatment with either creatine monohydrate (CR (~20 g·day-1 for one week followed by ~10 g·day-1 for a further eleven weeks or placebo (PL (dextrose in a double blind fashion. All subjects undertook moderate intensity aerobic training during three 40-minute sessions per week, over 3 months. High-density lipoprotein cholesterol (HDL, low-density lipoprotein cholesterol (LDL, very low-density lipoprotein cholesterol (VLDL, total cholesterol (TC, triglyceride (TAG, fasting insulin and fasting glycemia were analyzed in plasma. Thereafter, the homeostasis model assessment (HOMA was calculated. Tests were performed at baseline (Pre and after four (Post 4, eight (Post 8 and twelve (Post 12 weeks. Results We observed main time effects in both groups for HDL (Post 4 versus Post 8; P = 0.01, TAG and VLDL (Pre versus Post 4 and Post 8; P = 0.02 and P = 0.01, respectively. However, no between group differences were noted in HDL, LDL, CT, VLDL and TAG. Additionally, fasting insulin, fasting glycemia and HOMA did not change significantly. Conclusion These findings suggest that Cr supplementation does not exert any additional effect on the improvement in the plasma lipid profile than aerobic training alone.

Quiescent plasma machine for beam-plasma interaction and wave studies

International Nuclear Information System (INIS)

Ferreira, J.L.

1994-01-01

A quiescent double plasma machine for beam-plasma interaction wave studies is described. A detailed description of several plasma diagnostics used for plasma and wave excitation detection is given. A beam-plasma wave dispersion relation is used to compare theoretical values with the experimentally measured Langmuir wave frequencies and wavelengths. (author). 14 refs, 10 figs

Creatine supplementation reduces plasma levels of pro-inflammatory cytokines and PGE2 after a half-ironman competition.

Science.gov (United States)

Bassit, R A; Curi, R; Costa Rosa, L F B P

2008-08-01

The effect of creatine supplementation upon plasma levels of pro-inflammatory cytokines: Interleukin (IL) 1 beta and IL-6, Tumor Necrosis Factor alpha (TNFalpha), and Interferon alpha (INF alpha) and Prostaglandin E(2) (PGE(2)) after a half-ironman competition were investigated. Eleven triathletes, each with at least three years experience of participation in this sport were randomly divided between the control and experimental groups. During 5 days prior to competition, the control group (n = 6) was supplemented with carbohydrate (20 g x d(-1)) whereas the experimental group (n = 5) received creatine (20 g x d(-1)) in a double-blind trial. Blood samples were collected 48 h before and 24 and 48 h after competition and were used for the measurement of cytokines and PGE(2). Forty-eight hours prior to competition there was no difference between groups in the plasma concentrations (pg x ml(-1), mean +/- SEM) of IL-6 (7.08 +/- 0.63), TNFalpha (76.50 +/- 5.60), INF alpha (18.32 +/- 1.20), IL-1 beta (23.42 +/- 5.52), and PGE(2) (39.71 +/- 3.8). Twenty-four and 48 h after competition plasma levels of TNFalpha, INF alpha, IL-1 beta and PGE(2) were significantly increased (P long distance triathlon competition may reduce the inflammatory response induced by this form of strenuous of exercise.

Dynamic identification of plasma magnetic contour in fusion machines

International Nuclear Information System (INIS)

Bettini, P.; Trevisan, F.; Cavinato, M.

2005-01-01

The paper presents a method to identify the plasma magnetic contour in fusion machines, when eddy currents are present in the conducting structures surrounding the plasma. The approach presented is based on the integration of an electromagnetic model of the plasma with a lumped parameters model of the conducting structures around the plasma. This approach has been validated against experimental data from RFX, a reversed field pinch machine. (author)

Plasma hot machining for difficult-to-cut materials, 1

International Nuclear Information System (INIS)

Kitagawa, Takeaki; Maekawa, Katsuhiro; Kubo, Akihiko

1987-01-01

Machinability of difficult-to-cut materials has been a great concern to manufacturing engineers since demands for new materials in the aerospace and nuclear industries are more and more increasing. The purpose of this study is to develop a hot machining to improve machinability of high hardness materials. A plasma arc is used for heating materials cut. The surface just after being heated is removed as a chip by tungsten carbide tools. The turning experiments of high hardness steels with aid of plasma arc heating show not only the decrease in cutting forces but also the following effectiveness: (1) The application of the plasma hot machining to the condition, under which a built-up edge (BUE) appears in turning 0.46%C steel, makes the BUE disappeared, bringing less flank wear. (2) In the case of 18%Mn steel cutting, deep groove wear on the end-cutting edge diminishes, and roughness of the machined surface is improved by the prevention from chatter. (3) Although the chilled cast iron has high hardness of above HB = 350, the plasma hot machining makes it possible to cut it with tungsten carbide tools having less chipping and flank wear. (author)

21 CFR 862.1215 - Creatine phosphokinase/creatine kinase or isoenzymes test system.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Creatine phosphokinase/creatine kinase or... Clinical Chemistry Test Systems § 862.1215 Creatine phosphokinase/creatine kinase or isoenzymes test system. (a) Identification. A creatine phosphokinase/creatine kinase or isoenzymes test system is a device...

Creatine kinase activity in dogs with experimentally induced acute inflammation

Directory of Open Access Journals (Sweden)

Dimitrinka Zapryanova

2013-01-01

Full Text Available The main purpose of this study was to investigate the effect of acute inflammation on total creatine kinase (CK activity in dogs. In these animals, CK is an enzyme found predominantly in skeletal muscle and significantly elevated serum activity is largely associated with muscle damage. Plasma increases in dogs are associated with cell membrane leakage and will therefore be seen in any condition associated with muscular inflammation. The study was induced in 15 mongrel male dogs (n=9 in experimental group and n=6 in control group at the age of two years and body weight 12-15 kg. The inflammation was reproduced by inoculation of 2 ml turpentine oil subcutaneously in lumbar region. The plasma activity of creatine kinase was evaluated at 0, 6, 24, 48, 72 hours after inoculation and on days 7, 14 and 21 by a kit from Hospitex Diagnostics. In the experimental group, the plasma concentrations of the CK-activity were increased at the 48th hour (97.48±6.92 U/L and remained significantly higher (p<0.05 at the 72 hour (97.43±2.93 U/L compared to the control group (77.08±5.27 U/L. The results of this study suggest that the evaluation of creatine kinase in dogs with experimentally induced acute inflammation has a limited diagnostic value. It was observed that the creatine kinase activity is slightly affected by the experimentally induced acute inflammation in dogs.

Materials study for reacting plasma machine

International Nuclear Information System (INIS)

Kamada, Kohji; Hamada, Yasuji

1982-01-01

A new reacting plasma machine is designed, and will be constructed at the Institute of Plasma Physics, Nagoya University. It is important to avoid the activation of the materials for the machine, accordingly, aluminum alloy has been considered as the material since the induced activity of aluminum due to 14 MeV neutrons is small. The vacuum chamber of the new machine consists of four modules, and the remote control of each module is considered. However, the cost of the remote control of modules is expensive. To minimize the dependence on the remote control, the use of aluminum alloy is considered as the first step. The low electrical resistivity, over-ageing, weak mechanical strength and eddy current characteristics of aluminum alloy must be improved. The physical and electrical properties of various aluminum alloys have been investigated. Permeability of hydrogen through aluminum, the recycling characteristics and surface coating materials have been also studied. (Kato, T.)

Absolute Oral Bioavailability of Creatine Monohydrate in Rats: Debunking a Myth.

Science.gov (United States)

Alraddadi, Eman A; Lillico, Ryan; Vennerstrom, Jonathan L; Lakowski, Ted M; Miller, Donald W

2018-03-08

Creatine is an ergogenic compound used by athletes to enhance performance. Supplementation with creatine monohydrate (CM) has been suggested for musculoskeletal and neurological disorders. Until now, little is known about its pharmacokinetic profile. Our objective was to determine the oral bioavailability of CM and the influence of dose on oral absorption. Rats were dosed orally with low dose (10 mg/kg) or high dose (70 mg/kg) 13 C-labeled CM. Blood samples were removed at various time points. Muscle and brain tissue were collected at the conclusion of the study. Plasma and tissue levels of 13 C-labeled creatine were determined using liquid chromatography-tandem mass spectrometry (LC-MS/MS). Physiologically based pharmacokinetic (PBPK) models of CM were built using GastroPlus™. These models were used to predict the plasma concentration-time profiles of creatine hydrochloride (CHCL), which has improved aqueous solubility compared to CM. Absolute oral bioavailability for low dose CM was 53% while high dose CM was only 16%. The simulated C max of 70 mg/kg CHCL was around 35 μg/mL compared to 14 μg/mL for CM with a predicted oral bioavailability of 66% with CHCL compared to 17% with CM. Our results suggest that the oral bioavailability of CM is less than complete and subject to dose and that further examination of improved dosage formulations of creatine is warranted.

Guanidinoacetic acid versus creatine for improved brain and muscle creatine levels

DEFF Research Database (Denmark)

Ostojic, Sergej M; Ostojic, Jelena; Drid, Patrik

2016-01-01

In this randomized, double-blind, crossover trial, we evaluated whether 4-week supplementation with guanidinoacetic acid (GAA) is superior to creatine in facilitating creatine levels in healthy men (n = 5). GAA (3.0 g/day) resulted in a more powerful rise (up to 16.2%) in tissue creatine levels...... in vastus medialis muscle, middle-cerebellar peduncle, and paracentral grey matter, as compared with creatine (P creatine for improved bioenergetics in energy-demanding tissues....

Manipulator for plasma-assisted machining of components made of materials with low machinability

International Nuclear Information System (INIS)

Lyaoshchukov, M.M.; Agadzhanyan, R.A.

1984-01-01

The All-Union Scientific-Research and Technological Institute of Pump Engineering developed, and the ''Uralgidromash'' Production Association has adopted, a manipulator with remote control for the plasma-assisted machining (PAM) of components made of materials with low machinability. The manipulator is distinguished by its universal design and can be used for machining both external and internal surfaces of the bodies of revolution and also end faces and various curvilinear surfaces

Creatine for women: a review of the relationship between creatine and the reproductive cycle and female-specific benefits of creatine therapy.

Science.gov (United States)

Ellery, Stacey J; Walker, David W; Dickinson, Hayley

2016-08-01

The creatine/phosphocreatine/creatine kinase circuit is instrumental in regulating high-energy phosphate metabolism, and the maintenance of cellular energy turnover. The mechanisms by which creatine is able to buffer and regulate cellular energy balance, maintain acid-base balance, and reduce the effects of oxidative stress have led to a large number of studies into the use of creatine supplementation in exercise performance and to treat diseases associated with cellular energy depletion. Some of these studies have identified sex-specific responses to creatine supplementation, as such; there is the perception, that females might be less receptive to the benefits of creatine supplementation and therapy, compared to males. This review will describe the differences in male and female physique and physiology that may account for such differences, and discuss the apparent endocrine modulation of creatine metabolism in females. Hormone-driven changes to endogenous creatine synthesis, creatine transport and creatine kinase expression suggest that significant changes in this cellular energy circuit occur during specific stages of a female's reproductive life, including pregnancy and menopause. Recent studies suggest that creatine supplementation may be highly beneficial for women under certain conditions, such as depression. A greater understanding of these pathways, and the consequences of alterations to creatine bioavailability in females are needed to ensure that creatine is used to full advantage as a dietary supplement to optimize and enhance health outcomes for women.

An improved barium plasma source for q-machines

International Nuclear Information System (INIS)

Paris, P.J.; Gorgerat, P.; Simik, A.; Rynn, N.; Roe, S.; Schleipen, M.

1988-06-01

We have developed a stable q-machine with well determined parameters for long term times, of constant plasma density and temperature. The plasma characteristics and gun behaviour allow research in fundamental plasma physics, especially with the use of non perturbing powerful optical (LIF) diagnostics in the determination of many of the plasma parameters. (author) 17 figs., 2 tabs., 7 refs

Creatine Use in Sports.

Science.gov (United States)

Butts, Jessica; Jacobs, Bret; Silvis, Matthew

The use of creatine as a dietary supplement has become increasingly popular over the past several decades. Despite the popularity of creatine, questions remain with regard to dosing, effects on sports performance, and safety. PubMed was searched for articles published between 1980 and January 2017 using the terms creatine, creatine supplementation, sports performance, and dietary supplements. An additional Google search was performed to capture National Collegiate Athletic Association-specific creatine usage data and US dietary supplement and creatine sales. Clinical review. Level 4. Short-term use of creatine is considered safe and without significant adverse effects, although caution should be advised as the number of long-term studies is limited. Suggested dosing is variable, with many different regimens showing benefits. The safety of creatine supplementation has not been studied in children and adolescents. Currently, the scientific literature best supports creatine supplementation for increased performance in short-duration, maximal-intensity resistance training. While creatine appears to be safe and effective for particular settings, whether creatine supplementation leads to improved performance on the field of play remains unknown.

Machine and plasma diagnostic instrumentation systems for the Tandem Mirror Experiment Upgrade

International Nuclear Information System (INIS)

Coutts, G.W.; Coffield, F.E.; Lang, D.D.; Hornady, R.S.

1981-01-01

To evaluate performance of a second generation Tandem Mirror Machine, an extensive instrumentation system is being designed and installed as part of the major device fabrication. The systems listed will be operational during the start-up phase of the TMX Upgrade machine and provide bench marks for future performance data. In addition to plasma diagnostic instrumentation, machine parameter monitoring systems will be installed prior to machine operation. Simultaneous recording of machine parameters will permit evaluation of plasma parameters sensitive to machine conditions

A control approach for plasma density in tokamak machines

Energy Technology Data Exchange (ETDEWEB)

Boncagni, Luca, E-mail: luca.boncagni@enea.it [EURATOM – ENEA Fusion Association, Frascati Research Center, Division of Fusion Physics, Rome, Frascati (Italy); Pucci, Daniele; Piesco, F.; Zarfati, Emanuele [Dipartimento di Ingegneria Informatica, Automatica e Gestionale ' ' Antonio Ruberti' ' , Sapienza Università di Roma (Italy); Mazzitelli, G. [EURATOM – ENEA Fusion Association, Frascati Research Center, Division of Fusion Physics, Rome, Frascati (Italy); Monaco, S. [Dipartimento di Ingegneria Informatica, Automatica e Gestionale ' ' Antonio Ruberti' ' , Sapienza Università di Roma (Italy)

2013-10-15

Highlights: •We show a control approach for line plasma density in tokamak. •We show a control approach for pressure in a tokamak chamber. •We show experimental results using one valve. -- Abstract: In tokamak machines, chamber pre-fill is crucial to attain plasma breakdown, while plasma density control is instrumental for several tasks such as machine protection and achievement of desired plasma performances. This paper sets the principles of a new control strategy for attaining both chamber pre-fill and plasma density regulation. Assuming that the actuation mean is a piezoelectric valve driven by a varying voltage, the proposed control laws ensure convergence to reference values of chamber pressure during pre-fill, and of plasma density during plasma discharge. Experimental results at FTU are presented to discuss weaknesses and strengths of the proposed control strategy. The whole system has been implemented by using the MARTe framework [1].

Prevalence of Creatine Deficiency Syndromes in Children With Nonsyndromic Autism.

Science.gov (United States)

Schulze, Andreas; Bauman, Margaret; Tsai, Anne Chun-Hui; Reynolds, Ann; Roberts, Wendy; Anagnostou, Evdokia; Cameron, Jessie; Nozzolillo, Alixandra A; Chen, Shiyi; Kyriakopoulou, Lianna; Scherer, Stephen W; Loh, Alvin

2016-01-01

Creatine deficiency may play a role in the neurobiology of autism and may represent a treatable cause of autism. The goal of the study was to ascertain the prevalence of creatine deficiency syndromes (CDSs) in children with autism spectrum disorder (ASD). In a prospective multicenter study, 443 children were investigated after a confirmed diagnosis of ASD. Random spot urine screening for creatine metabolites (creatine, guanidinoacetate, creatinine, and arginine) with liquid chromatography-tandem mass spectrometry and second-tier testing with high-performance liquid chromatography methodology was followed by recall testing in 24-hour urines and confirmatory testing by Sanger-based DNA sequencing of GAMT, GATM, and SLC6A8 genes. Additional diagnostic tests included plasma creatine metabolites and in vivo brain proton magnetic resonance spectroscopy. The creatine metabolites in spot urine in the autism group were compared with 128 healthy controls controlled for age. In 443 subjects with ASD investigated for CDS, we had 0 events (event: 0, 95% confidence interval 0-0.0068), therefore with 95% confidence the prevalence of CDS is creatine metabolites (P > .0125) in urine. Our study revealed a very low prevalence of CDS in children with nonsyndromic ASD and no obvious association between creatine metabolites and autism. Unlike our study population, we expect more frequent CDS among children with severe developmental delay, speech impairment, seizures, and movement disorders in addition to impairments in social communication, restricted interests, and repetitive behaviors. Copyright © 2016 by the American Academy of Pediatrics.

Free creatine available to the creatine phosphate energy shuttle in isolated rat atria

International Nuclear Information System (INIS)

Savabi, F.

1988-01-01

To measure the actual percentage of intracellular free creatine participating in the process of energy transport, the incorporation of [1- 14 C]creatine into the free creatine and phosphocreatine (PCr) pools in spontaneously beating isolated rat atria, under various conditions, was examined. The atria were subjected to three consecutive periods, control, anoxia, and postanoxic recover, in medium containing tracers of [1- 14 C]creatine. The tissue content and specific activity of creatine and PCr were determined at the end of each period. The higher specific activity found for tissue PCr (1.87 times) than creatine, independent of the percentage of total intracellular creatine that was present as free creatine, provides evidence for the existence of two separate pools of free creatine. Analysis of the data shows that in the normal oxygenated state ∼ 9% of the total intracellular creatine is actually free to participate in the process of energy transport (shuttle pool). About 36% of the total creatine is bound to unknown intracellular components and the rest exists as PCr. The creatine that was taken up and the creatine that was released from the breakdown of PCr have much greater access to the site of phosphorylation than the rest of the intracellular creatine. A sharp increase in the specific activity of residual PCr on prolongation of anoxic time was also observed. This provides evidence for a nonhomogeneous pool of PCr, for the most recently formed (radioactive) PCr appeared to be hydrolyzed last

Radioimmunoassay measurement of plasma oxytocin and vasopressin in cows during machine milking

Energy Technology Data Exchange (ETDEWEB)

Landgraf, R; Wehowsky, G; Schulz, J; Schulze, H; Bothur, D [Forschungsinstitut fuer Koerperkultur und Sport, Leipzig (German Democratic Republic); Karl-Marx-Universitaet, Leipzig (German Democratic Republic). Sektion Tierproduktion und Veterinaermedizin)

1982-07-01

The response of plasma oxytocin and vasopressin to machine milking in cows was studied by radioimmunoassay. Depending on the method of machine milking used, plasma oxytocin increased to a greater or lesser degree after teat cup application. Plasma vasopressin was not affected by the milking procedures.

Creatine metabolism and psychiatric disorders: Does creatine supplementation have therapeutic value?

Science.gov (United States)

Allen, Patricia J.

2012-01-01

Athletes, body builders, and military personnel use dietary creatine as an ergogenic aid to boost physical performance in sports involving short bursts of high-intensity muscle activity. Lesser known is the essential role creatine, a natural regulator of energy homeostasis, plays in brain function and development. Creatine supplementation has shown promise as a safe, effective, and tolerable adjunct to medication for the treatment of brain-related disorders linked with dysfunctional energy metabolism, such as Huntington’s Disease and Parkinson’s Disease. Impairments in creatine metabolism have also been implicated in the pathogenesis of psychiatric disorders, leaving clinicians, researchers and patients alike wondering if dietary creatine has therapeutic value for treating mental illness. The present review summarizes the neurobiology of the creatine-phosphocreatine circuit and its relation to psychological stress, schizophrenia, mood and anxiety disorders. While present knowledge of the role of creatine in cognitive and emotional processing is in its infancy, further research on this endogenous metabolite has the potential to advance our understanding of the biological bases of psychopathology and improve current therapeutic strategies. PMID:22465051

Dietary creatine supplementation during pregnancy: a study on the effects of creatine supplementation on creatine homeostasis and renal excretory function in spiny mice.

Science.gov (United States)

Ellery, Stacey J; LaRosa, Domenic A; Kett, Michelle M; Della Gatta, Paul A; Snow, Rod J; Walker, David W; Dickinson, Hayley

2016-08-01

Recent evidence obtained from a rodent model of birth asphyxia shows that supplementation of the maternal diet with creatine during pregnancy protects the neonate from multi-organ damage. However, the effect of increasing creatine intake on creatine homeostasis and biosynthesis in females, particularly during pregnancy, is unknown. This study assessed the impact of creatine supplementation on creatine homeostasis, body composition, capacity for de novo creatine synthesis and renal excretory function in non-pregnant and pregnant spiny mice. Mid-gestation pregnant and virgin spiny mice were fed normal chow or chow supplemented with 5 % w/w creatine for 18 days. Weight gain, urinary creatine and electrolyte excretion were assessed during supplementation. At post mortem, body composition was assessed by Dual-energy X-ray absorptiometry, or tissues were collected to assess creatine content and mRNA expression of the creatine synthesising enzymes arginine:glycine amidinotransferase (AGAT) and guanidinoacetate methyltransferase (GAMT) and the creatine transporter (CrT1). Protein expression of AGAT and GAMT was also assessed by Western blot. Key findings of this study include no changes in body weight or composition with creatine supplementation; increased urinary creatine excretion in supplemented spiny mice, with increased sodium (P < 0.001) and chloride (P < 0.05) excretion in pregnant dams after 3 days of supplementation; lowered renal AGAT mRNA (P < 0.001) and protein (P < 0.001) expressions, and lowered CrT1 mRNA expression in the kidney (P < 0.01) and brain (P < 0.001). Creatine supplementation had minimal impact on creatine homeostasis in either non-pregnant or pregnant spiny mice. Increasing maternal dietary creatine consumption could be a useful treatment for birth asphyxia.

Assessment of creatine kinase and lactate dehydrogenase activities ...

African Journals Online (AJOL)

Ina bid to investigate the influence of menopausal on coronary heart disease, plasma creatine kinase (CK) and lactate dehydrogenase (LDH) enzymes were analysed on a prospective cohort of 100 women attending Irrua Specialist Teaching Hospital (ISTH), Irrua, Edo state-Nigeria. They were divided into two groups; ...

Creatine-creatine phosphate shuttle modeled as two-compartment system at different levels of creatine kinase activity

DEFF Research Database (Denmark)

Fedosov, Sergey

1994-01-01

In order to characterize ADP-ATP and creatine-creatine phosphate (Cr-CrP) shuttles a minimal mathematical model with two compartments and cyclic turnover of matter was designed. The 'mitochondrial' compartment contained 'ATP-synthase' and 'mitochondrial ereatine kinase' (mitCK). The 'cytoplasmic......' compartment consisted of 'ATPase', 'cytoplasmic creatine kinase' (cytCK) and an 'ADP-binding structure'. The exchange of metabolites between these compartments was limited. Different levels of cytCK and mitCK expression as welt as different exchange rate constants between the compartments were assigned...

Does brain creatine content rely on exogenous creatine in healthy youth? A proof-of-principle study.

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Merege-Filho, Carlos Alberto Abujabra; Otaduy, Maria Concepción Garcia; de Sá-Pinto, Ana Lúcia; de Oliveira, Maira Okada; de Souza Gonçalves, Lívia; Hayashi, Ana Paula Tanaka; Roschel, Hamilton; Pereira, Rosa Maria Rodrigues; Silva, Clovis Artur; Brucki, Sonia Maria Dozzi; da Costa Leite, Claudia; Gualano, Bruno

2017-02-01

It has been hypothesized that dietary creatine could influence cognitive performance by increasing brain creatine in developing individuals. This double-blind, randomized, placebo-controlled, proof-of-principle study aimed to investigate the effects of creatine supplementation on cognitive function and brain creatine content in healthy youth. The sample comprised 67 healthy participants aged 10 to 12 years. The participants were given creatine or placebo supplementation for 7 days. At baseline and after the intervention, participants undertook a battery of cognitive tests. In a random subsample of participants, brain creatine content was also assessed in the regions of left dorsolateral prefrontal cortex, left hippocampus, and occipital lobe by proton magnetic resonance spectroscopy (1H-MRS) technique. The scores obtained from verbal learning and executive functions tests did not significantly differ between groups at baseline or after the intervention (all p > 0.05). Creatine content was not significantly different between groups in left dorsolateral prefrontal cortex, left hippocampus, and occipital lobe (all p > 0.05). In conclusion, a 7-day creatine supplementation protocol did not elicit improvements in brain creatine content or cognitive performance in healthy youth, suggesting that this population mainly relies on brain creatine synthesis rather than exogenous creatine intake to maintain brain creatine homeostasis.

Creatine metabolism and psychiatric disorders: Does creatine supplementation have therapeutic value?

OpenAIRE

Allen, Patricia J.

2012-01-01

Athletes, body builders, and military personnel use dietary creatine as an ergogenic aid to boost physical performance in sports involving short bursts of high-intensity muscle activity. Lesser known is the essential role creatine, a natural regulator of energy homeostasis, plays in brain function and development. Creatine supplementation has shown promise as a safe, effective, and tolerable adjunct to medication for the treatment of brain-related disorders linked with dysfunctional energy me...

Creatine phosphokinase test

Science.gov (United States)

... this page: //medlineplus.gov/ency/article/003503.htm Creatine phosphokinase test To use the sharing features on this page, please enable JavaScript. Creatine phosphokinase (CPK) is an enzyme in the body. ...

Experimental works in plasma developed in INPE (Brazil). 1. Double plasma machine for longitudinal wave study. 2. Plasma centrifuge

International Nuclear Information System (INIS)

Ferreira, J.L.; Ludwig, G.O.; Del Bosco, E.

1982-01-01

This work describes some experiments done at the Plasma Physics Laboratory at INPE. In the first part, the double plasma machine used for the study of ion acoustic wave propagation is described, and the results obtained so far are shown. The second part consists in the description of a plasma centrifuge project. It contains some basic parameters of our apparatus used for isotope separation, throuth electromagtnetic rotation of the plasma. (Author) [pt

Changing to a vegetarian diet reduces the body creatine pool in omnivorous women, but appears not to affect carnitine and carnosine homeostasis: a randomised trial.

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Blancquaert, Laura; Baguet, Audrey; Bex, Tine; Volkaert, Anneke; Everaert, Inge; Delanghe, Joris; Petrovic, Mirko; Vervaet, Chris; De Henauw, Stefaan; Constantin-Teodosiu, Dumitru; Greenhaff, Paul; Derave, Wim

2018-04-01

Balanced vegetarian diets are popular, although they are nearly absent in creatine and carnosine and contain considerably less carnitine than non-vegetarian diets. Few longitudinal intervention studies investigating the effect of a vegetarian diet on the availability of these compounds currently exist. We aimed to investigate the effect of transiently switching omnivores onto a vegetarian diet for 6 months on muscle and plasma creatine, carnitine and carnosine homeostasis. In a 6-month intervention, forty omnivorous women were ascribed to three groups: continued omnivorous diet (control, n 10), vegetarian diet without supplementation (Veg+Pla, n 15) and vegetarian diet combined with daily β-alanine (0·8-0·4 g/d) and creatine supplementation (1 g creatine monohydrate/d) (Veg+Suppl, n 15). Before (0 months; 0M), after 3 months (3M) and 6 months (6M), a fasted venous blood sample and 24-h urine was collected, and muscle carnosine content was determined by proton magnetic resonance spectroscopy (1H-MRS). Muscle biopsies were obtained at 0M and 3M. Plasma creatine and muscle total creatine content declined from 0M to 3M in Veg+Pla (P=0·013 and P=0·009, respectively), whereas plasma creatine increased from 0M in Veg+Suppl (P=0·004). None of the carnitine-related compounds in plasma or muscle showed a significant time×group interaction effect. 1H-MRS-determined muscle carnosine content was unchanged over 6M in control and Veg+Pla, but increased in Veg+Suppl in soleus (Pvegetarian diet in omnivorous women, which was ameliorated when accompanied by low-dose dietary creatine supplementation. Carnitine and carnosine homeostasis was unaffected by a 3- or 6-month vegetarian diet, respectively.

Study of discharge in quiescent plasma machine of the INPE

International Nuclear Information System (INIS)

Ferreira, J.G.; Ferreira, J.L.; Ludwig, G.O.; Maciel, H.S.

1988-12-01

Measurements of principal plasma parameters produced by quiescent plasma machine of the Instituto de Pesquisas Espaciais (INPE) for current of 500 mA and several values of pressure and discharge power are presented. A qualitative interpretation for obtained results is done and a simple model for plasma density is compared with experimental values. The conditions of cathode operation are also investigated. (M.C.K.)

The Regulation and Expression of the Creatine Transporter: A Brief Review of Creatine Supplementation in Humans and Animals

OpenAIRE

Schoch, Ryan D; Willoughby, Darryn; Greenwood, Mike

2006-01-01

Abstract Creatine monohydrate has become one of the most popular ergogenic sport supplements used today. It is a nonessential dietary compound that is both endogenously synthesized and naturally ingested through diet. Creatine ingested through supplementation has been observed to be absorbed into the muscle exclusively by means of a creatine transporter, CreaT1. The major rationale of creatine supplementation is to maximize the increase within the intracellular pool of total creatine (creatin...

Total body skeletal muscle mass: estimation by creatine (methyl-d3) dilution in humans

Science.gov (United States)

Walker, Ann C.; O'Connor-Semmes, Robin L.; Leonard, Michael S.; Miller, Ram R.; Stimpson, Stephen A.; Turner, Scott M.; Ravussin, Eric; Cefalu, William T.; Hellerstein, Marc K.; Evans, William J.

2014-01-01

Current methods for clinical estimation of total body skeletal muscle mass have significant limitations. We tested the hypothesis that creatine (methyl-d3) dilution (D3-creatine) measured by enrichment of urine D3-creatinine reveals total body creatine pool size, providing an accurate estimate of total body skeletal muscle mass. Healthy subjects with different muscle masses [n = 35: 20 men (19–30 yr, 70–84 yr), 15 postmenopausal women (51–62 yr, 70–84 yr)] were housed for 5 days. Optimal tracer dose was explored with single oral doses of 30, 60, or 100 mg D3-creatine given on day 1. Serial plasma samples were collected for D3-creatine pharmacokinetics. All urine was collected through day 5. Creatine and creatinine (deuterated and unlabeled) were measured by liquid chromatography mass spectrometry. Total body creatine pool size and muscle mass were calculated from D3-creatinine enrichment in urine. Muscle mass was also measured by magnetic resonance imaging (MRI), dual-energy x-ray absorptiometry (DXA), and traditional 24-h urine creatinine. D3-creatine was rapidly absorbed and cleared with variable urinary excretion. Isotopic steady-state of D3-creatinine enrichment in the urine was achieved by 30.7 ± 11.2 h. Mean steady-state enrichment in urine provided muscle mass estimates that correlated well with MRI estimates for all subjects (r = 0.868, P creatine dose determined by urine D3-creatinine enrichment provides an estimate of total body muscle mass strongly correlated with estimates from serial MRI with less bias than total lean body mass assessment by DXA. PMID:24764133

Effects of Combined Creatine Plus Fenugreek Extract vs. Creatine Plus Carbohydrate Supplementation on Resistance Training Adaptations

Science.gov (United States)

Taylor, Lem; Poole, Chris; Pena, Earnest; Lewing, Morgan; Kreider, Richard; Foster, Cliffa; Wilborn, Colin

2011-01-01

The purpose of this study was to evaluate the effects of combined creatine and fenugreek extract supplementation on strength and body composition. Forty- seven resistance trained men were matched according to body weight to ingest either 70 g of a dextrose placebo (PL), 5 g creatine/70 g of dextrose (CRD) or 3.5 g creatine/900 mg fenugreek extract (CRF) and participate in a 4-d/wk periodized resistance-training program for 8-weeks. At 0, 4, and 8-weeks, subjects were tested on body composition, muscular strength and endurance, and anaerobic capacity. Statistical analyses utilized a separate 3X3 (condition [PL vs. CRD vs. CRF] x time [T1 vs. T2 vs. T3]) ANOVAs with repeated measures for all criterion variables (p ≤ 0.05). No group x time interaction effects or main effects (p > 0.05) were observed for any measures of body composition. CRF group showed significant increases in lean mass at T2 (p = 0.001) and T3 (p = 0.001). Bench press 1RM increased in PL group (p = 0.050) from T1-T3 and in CRD from T1-T2 (p = 0. 001) while remaining significant at T3 (p 0.05). In conclusion, creatine plus fenugreek extract supplementation had a significant impact on upper body strength and body composition as effectively as the combination of 5g of creatine with 70g of dextrose. Thus, the use of fenugreek with creatine supplementation may be an effective means for enhancing creatine uptake while eliminating the need for excessive amounts of simple carbohydrates. Key points Fenugreek plus creatine supplementation may be a new means of increasing creatine uptake. Creatine plus fenugreek seems to be just as effective as the classic creatine plus carbohydrate ingestion in terms of stimulating training adaptations. This is the first study to our knowledge that has combined fenugreek with creatine supplementation in conjunction with a resistance training program. PMID:24149869

Simultaneous Assay of Isotopic Enrichment and Concentration of Guanidinoacetate and Creatine by Gas Chromatography-Mass Spectrometry

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Kasumov, Takhar; Gruca, Lourdes L.; Dasarathy, Srinivasan; Kalhan, Satish C.

2012-01-01

A gas chromatographic-mass spectrometric (GC-MS) method for the simultaneous measurement of isotopic enrichment and concentration of guanidinoacetic acid and creatine in plasma sample for kinetic studies is reported. The method, based on preparation of the bis(trifluoromethyl)-pyrimidine methyl ester derivatives of guanidinoacetic acid and creatine, is robust and sensitive. The lowest measurable m1 and m3 enrichment for guanidinoacetic acid and creatine, respectively, was 0.3%. The calibration curves for measurements of concentration were linear over a range of 0.5-250 μM guanidinoacetic acid and 2-500 μM for creatine. The method was reliable for inter-assay and intra-assay precision, accuracy and linearity. The technique was applied in a healthy adult to determine in vivo fractional synthesis rate of creatine using primed- constant rate infusion of [1-13C]glycine. It was found that isotopic enrichment of guanidinoacetic acid reached plateau by 30 min of infusion of [1-13C]glycine, indicating either a small pool size or a rapid turnover rate or both, of guanidinoacetic acid. In contrast, tracer appearance in creatin was slow (slope: 0.00097), suggesting a large pool size and a slow rate of synthesis of creatine. This method can be used to estimate rate of synthesis of creatine in-vivo in human and animal studies. PMID:19646413

Moderate elevation of intracellular creatine by targeting the creatine transporter protects mice from acute myocardial infarction

Science.gov (United States)

Lygate, Craig A.; Bohl, Steffen; ten Hove, Michiel; Faller, Kiterie M.E.; Ostrowski, Philip J.; Zervou, Sevasti; Medway, Debra J.; Aksentijevic, Dunja; Sebag-Montefiore, Liam; Wallis, Julie; Clarke, Kieran; Watkins, Hugh; Schneider, Jürgen E.; Neubauer, Stefan

2012-01-01

Aims Increasing energy storage capacity by elevating creatine and phosphocreatine (PCr) levels to increase ATP availability is an attractive concept for protecting against ischaemia and heart failure. However, testing this hypothesis has not been possible since oral creatine supplementation is ineffectual at elevating myocardial creatine levels. We therefore used mice overexpressing creatine transporter in the heart (CrT-OE) to test for the first time whether elevated creatine is beneficial in clinically relevant disease models of heart failure and ischaemia/reperfusion (I/R) injury. Methods and results CrT-OE mice were selected for left ventricular (LV) creatine 20–100% above wild-type values and subjected to acute and chronic coronary artery ligation. Increasing myocardial creatine up to 100% was not detrimental even in ageing CrT-OE. In chronic heart failure, creatine elevation was neither beneficial nor detrimental, with no effect on survival, LV remodelling or dysfunction. However, CrT-OE hearts were protected against I/R injury in vivo in a dose-dependent manner (average 27% less myocardial necrosis) and exhibited greatly improved functional recovery following ex vivo I/R (59% of baseline vs. 29%). Mechanisms contributing to ischaemic protection in CrT-OE hearts include elevated PCr and glycogen levels and improved energy reserve. Furthermore, creatine loading in HL-1 cells did not alter antioxidant defences, but delayed mitochondrial permeability transition pore opening in response to oxidative stress, suggesting an additional mechanism to prevent reperfusion injury. Conclusion Elevation of myocardial creatine by 20–100% reduced myocardial stunning and I/R injury via pleiotropic mechanisms, suggesting CrT activation as a novel, potentially translatable target for cardiac protection from ischaemia. PMID:22915766

In vitro and in vivo studies of creatine monohydrate supplementation to Duroc and Landrace pigs

DEFF Research Database (Denmark)

Young, Jette F.; Bertram, Hanne Christine; Theil, Peter Kappel

2007-01-01

Duroc and Landrace pigs as well as primary myotubes from these breeds were used to investigate mechanisms behind differences in their response to creatine monohydrate (CMH). Pigs were supplemented with 0, 12.5, 25 or 50g CMH/d for 5 days (n=10 per treatment and breed). Plasma levels of creatine...... increased dose-dependently in both breeds, while muscle-creatine phosphate content increased only in the Duroc pigs. (1)H NMR metabolic profiling showed a tendency towards clustering according to CMH supplementation only among Duroc pigs, revealing a stronger response compared to Landrace pigs....... The abundance of insulin-like growth factor I and myostatin mRNA was decreased by CMH supplementation while that of type 1 IGF-receptor and creatine transporter was unaffected. Protein synthesis, increased in the myotubes from both breeds, indicating protein accretion, but no effect was observed on the m...

Use of plasma creatine kinase pharmacokinetics to estimate the amount of excercise-induced muscle damage in Beagles.

Science.gov (United States)

Chanoit, G P; Lefebvre, H P; Orcel, K; Laroute, V; Toutain, P L; Braun, J P

2001-09-01

To assess the effects of moderate exercise on plasma creatine kinase (CK) pharmacokinetics and to estimate exercise-induced muscle damage in dogs. 6 untrained adult Beagles. The study was divided into 3 phases. In phase 1, dogs ran for 1 hour at a speed of 9 km/h, and samples were used to determine the area under the plasma CK activity versus time curve (AUC) induced by exercise. In phases 2 and 3, pharmacokinetics of CK were calculated in dogs during exercise and at rest, respectively. Values for AUC and plasma clearance (CI) were used to estimate muscle damage. At rest, values for Cl, steady-state volume of distribution (Vdss), and mean retention time (MRT) were 0.32+/-0.02 ml/kg of body weight/min, 57+/-173 ml/kg, and 3.0+/-0.57 h, respectively. During exercise, Cl decreased significantly (0.26+/-0.03 ml/kg/min), MRT increased significantly, (4.4+/-0.97 h), and Vdss remained unchanged. Peak of plasma CK activity (151+/-58.8 U/L) was observed 3 hours after completion of exercise. Estimated equivalent amount of muscle corresponding to the quantity of CK released was 41+/-29.3 mg/kg. These results revealed that exercise had a minor effect on CK disposition and that the equivalent amount of muscle damaged by moderate exercise was negligible. This study illustrates the relevance for use of the minimally invasive and quantitative pharmacokinetic approach when estimating muscle damage.

Guanidinoacetic acid versus creatine for improved brain and muscle creatine levels: a superiority pilot trial in healthy men.

Science.gov (United States)

Ostojic, Sergej M; Ostojic, Jelena; Drid, Patrik; Vranes, Milan

2016-09-01

In this randomized, double-blind, crossover trial, we evaluated whether 4-week supplementation with guanidinoacetic acid (GAA) is superior to creatine in facilitating creatine levels in healthy men (n = 5). GAA (3.0 g/day) resulted in a more powerful rise (up to 16.2%) in tissue creatine levels in vastus medialis muscle, middle-cerebellar peduncle, and paracentral grey matter, as compared with creatine (P creatine for improved bioenergetics in energy-demanding tissues.

Living Without Creatine: Unchanged Exercise Capacity and Response to Chronic Myocardial Infarction in Creatine-Deficient Mice

Science.gov (United States)

Lygate, Craig A.; Aksentijevic, Dunja; Dawson, Dana; Hove, Michiel ten; Phillips, Darci; de Bono, Joseph P.; Medway, Debra J.; Sebag-Montefiore, Liam; Hunyor, Imre; Channon, Keith M.; Clarke, Kieran; Zervou, Sevasti; Watkins, Hugh; Balaban, Robert S.; Neubauer, Stefan

2014-01-01

Rationale Creatine is thought to be involved in the spatial and temporal buffering of ATP in energetic organs such as heart and skeletal muscle. Creatine depletion affects force generation during maximal stimulation, while reduced levels of myocardial creatine are a hallmark of the failing heart, leading to the widely held view that creatine is important at high workloads and under conditions of pathological stress. Objective We therefore hypothesised that the consequences of creatine-deficiency in mice would be impaired running capacity, and exacerbation of heart failure following myocardial infarction. Methods and Results Surprisingly, mice with whole-body creatine deficiency due to knockout of the biosynthetic enzyme (guanidinoacetate N-methyltransferase – GAMT) voluntarily ran just as fast and as far as controls (>10km/night) and performed the same level of work when tested to exhaustion on a treadmill. Furthermore, survival following myocardial infarction was not altered, nor was subsequent LV remodelling and development of chronic heart failure exacerbated, as measured by 3D-echocardiography and invasive hemodynamics. These findings could not be accounted for by compensatory adaptations, with no differences detected between WT and GAMT−/− proteomes. Alternative phosphotransfer mechanisms were explored; adenylate kinase activity was unaltered, and although GAMT−/− hearts accumulated the creatine pre-cursor guanidinoacetate, this had negligible energy-transfer activity, while mitochondria retained near normal function. Conclusions Creatine-deficient mice show unaltered maximal exercise capacity and response to chronic myocardial infarction, and no obvious metabolic adaptations. Our results question the paradigm that creatine is essential for high workload and chronic stress responses in heart and skeletal muscle. PMID:23325497

Plasma creatine kinase B correlates with injury severity and symptoms in professional boxers.

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Kilianski, Joseph; Peeters, Sophie; Debad, Jeff; Mohmed, Joseph; Wolf, Steven E; Minei, Joseph P; Diaz-Arrastia, Ramon; Gatson, Joshua W

2017-11-01

Each year in the United States, approximately 1.7 million people sustain a traumatic brain injury (TBI). Of these TBI events, about 75 percent are characterized as being mild brain injuries. Immediately following TBI, a secondary brain damage persists for hours, days, and even months. Previously, detection of neuronal and glial biomarkers have proven to be useful to predict neurological outcomes. Here, we hypothesized that creatine kinase, brain (CKBB) is a sensitive biomarker for acute secondary brain injury in professional boxers. Blood (8cc) was collected from the boxing athletes (n=18) prior to and after competition (∼30min). The plasma levels of CKBB were measured using the Meso Scale Diagnostic (MSD) electrochemiluminescence (ECL) array-based multiplex format. Additional data such as number of blows to the head and symptom score (Rivermead Post Concussion Symptoms Questionnaire) were collected. At approximately 30min after the competition, the plasma levels of CKBB were significantly elevated in concussed professional boxers and correlated with the number of blows to the head and symptom scores. Additionally, receiver operating curve (ROC) analysis yielded a 77.8% sensitivity and a specificity of 82.4% with an area under the curve (AUC) of 90% for CKBB as an identifier of secondary brain injury within this population. This study describes the detection of CKBB as a brain biomarker to detect secondary brain injury in professional athletes that have experienced multiple high impact blows to the head. This acute biomarker may prove useful in monitoring secondary brain injury after injury. Copyright © 2017 Elsevier Ltd. All rights reserved.

Beyond muscles: The untapped potential of creatine.

Science.gov (United States)

Riesberg, Lisa A; Weed, Stephanie A; McDonald, Thomas L; Eckerson, Joan M; Drescher, Kristen M

2016-08-01

Creatine is widely used by both elite and recreational athletes as an ergogenic aid to enhance anaerobic exercise performance. Older individuals also use creatine to prevent sarcopenia and, accordingly, may have therapeutic benefits for muscle wasting diseases. Although the effect of creatine on the musculoskeletal system has been extensively studied, less attention has been paid to its potential effects on other physiological systems. Because there is a significant pool of creatine in the brain, the utility of creatine supplementation has been examined in vitro as well as in vivo in both animal models of neurological disorders and in humans. While the data are preliminary, there is evidence to suggest that individuals with certain neurological conditions may benefit from exogenous creatine supplementation if treatment protocols can be optimized. A small number of studies that have examined the impact of creatine on the immune system have shown an alteration in soluble mediator production and the expression of molecules involved in recognizing infections, specifically toll-like receptors. Future investigations evaluating the total impact of creatine supplementation are required to better understand the benefits and risks of creatine use, particularly since there is increasing evidence that creatine may have a regulatory impact on the immune system. Copyright © 2016 Elsevier B.V. All rights reserved.

Creatine and creatine pyruvate reduce hypoxia-induced effects on phrenic nerve activity in the juvenile mouse respiratory system.

Science.gov (United States)

Scheer, Monika; Bischoff, Anna M; Kruzliak, Peter; Opatrilova, Radka; Bovell, Douglas; Büsselberg, Dietrich

2016-08-01

Adequate concentrations of ATP are required to preserve physiological cell functions and protect tissue from hypoxic damage. Decreased oxygen concentration results in ATP synthesis relying increasingly on the presence of phosphocreatine. The lack of ATP through hypoxic insult to neurons that generate or regulate respiratory function, would lead to the cessation of breathing (apnea). It is not clear whether creatine plays a role in maintaining respiratory phrenic nerve (PN) activity during hypoxic challenge. The aim of the study was to test the effects of exogenously applied creatine or creatine pyruvate in maintaining PN induced respiratory rhythm against the deleterious effects of severe hypoxic insult using Working Heart-Brainstem (WHB) preparations of juvenile Swiss type mice. WHB's were perfused with control perfusate or perfusate containing either creatine [100μM] or creatine pyruvate [100μM] prior to hypoxic challenge and PN activity recorded throughout. Results showed that severe hypoxic challenge resulted in an initial transient increase in PN activity, followed by a reduction in that activity leading to respiratory apnea. The results demonstrated that perfusing the WHB preparation with creatine or creatine pyruvate, significantly reduced the onset of apnea compared to control conditions, with creatine pyruvate being the more effective substance. Overall, creatine and creatine pyruvate each produced time-dependent degrees of protection against severe hypoxic-induced disturbances of PN activity. The underlying protective mechanisms are unknown and need further investigations. Copyright © 2016 Elsevier Inc. All rights reserved.

Improvement of the thickness distribution of a quartz crystal wafer by numerically controlled plasma chemical vaporization machining

International Nuclear Information System (INIS)

Shibahara, Masafumi; Yamamura, Kazuya; Sano, Yasuhisa; Sugiyama, Tsuyoshi; Endo, Katsuyoshi; Mori, Yuzo

2005-01-01

To improve the thickness uniformity of thin quartz crystal wafer, a new machining process that utilizes an atmospheric pressure plasma was developed. In an atmospheric pressure plasma process, since the kinetic energy of ions that impinge to the wafer surface is small and the density of the reactive species is large, high-efficiency machining without damage is realized, and the thickness distribution is corrected by numerically controlled scanning of the quartz wafer to the localized high-density plasma. By using our developed machining process, the thickness distribution of an AT cut wafer was improved from 174 nm [peak to valley (p-v)] to 67 nm (p-v) within 94 s. Since there are no unwanted spurious modes in the machined quartz wafer, it was proved that the developed machining method has a high machining efficiency without any damage

Creatine synthesis and exchanges between brain cells: What can be learned from human creatine deficiencies and various experimental models?

Science.gov (United States)

Hanna-El-Daher, Layane; Braissant, Olivier

2016-08-01

While it has long been thought that most of cerebral creatine is of peripheral origin, the last 20 years has provided evidence that the creatine synthetic pathway (AGAT and GAMT enzymes) is expressed in the brain together with the creatine transporter (SLC6A8). It has also been shown that SLC6A8 is expressed by microcapillary endothelial cells at the blood-brain barrier, but is absent from surrounding astrocytes, raising the concept that the blood-brain barrier has a limited permeability for peripheral creatine. The first creatine deficiency syndrome in humans was also discovered 20 years ago (GAMT deficiency), followed later by AGAT and SLC6A8 deficiencies, all three diseases being characterized by creatine deficiency in the CNS and essentially affecting the brain. By reviewing the numerous and latest experimental studies addressing creatine transport and synthesis in the CNS, as well as the clinical and biochemical characteristics of creatine-deficient patients, our aim was to delineate a clearer view of the roles of the blood-brain and blood-cerebrospinal fluid barriers in the transport of creatine and guanidinoacetate between periphery and CNS, and on the intracerebral synthesis and transport of creatine. This review also addresses the question of guanidinoacetate toxicity for brain cells, as probably found under GAMT deficiency.

The Effects of Pre-slaughter Stress and Season on the Activity of Plasma Creatine Kinase and Mutton Quality from Different Sheep Breeds Slaughtered at a Smallholder Abattoir

Directory of Open Access Journals (Sweden)

A. Y. Chulayo

2013-12-01

Full Text Available The objective of the current study was to determine the effect of pre-slaughter stress, season and breed on the activity of plasma creatine kinase (CK and the quality of mutton. One hundred and seventy-three (173 castrated sheep from Dormer (DM, South African Mutton Merino (SAMM, Dorper (DP and Blackhead Persian (BP sheep breeds were used in the study. The animals were grouped according to age-groups as follows: Group 1 (6 to 8 months, Group 2 (9 to 12 months and Group 3 (13 to 16 months. Blood samples were collected during exsanguinations using disposable vacutainer tubes for CK analysis. Representative samples of the Muscularis longissimuss thoracis et. lumborum (LTL were collected from 84 castrated sheep, of different breeds (28 per breed 24 h after slaughter. The following physico-chemical characteristics of mutton were determined; meat pH (pH24, color (L*, a* and b*, thawing and cooking losses and Warner Braztler Shear Force (WBSF. The activity of plasma CK was significantly higher (p0.001 levels (1,358.6±191.08 of CK. South African Mutton Merino had higher values for pH24 (5.9±0.06, L* (34.2±0.97, b* (12.2±0.50 and WBSF (26.8±1.51 and Blackhead Persian had higher values (35.5±2.17 for cooking loss (CL% than the other breeds. Computed Principal Component Analyses (PCA on the activity of plasma CK and physico-chemical characteristics of mutton revealed no correlations between these variables. However, positive correlations were observed between pH24, L*, a*, b*, CL% and WBSF. Relationships between pre-slaughter stress, CK activity and physico-chemical characteristics of mutton were also observed. It was therefore concluded that although mutton quality and creatine kinase were not related, pre-slaughter stress, season and breed affected the activity of creatine kinase and mutton quality.

Creatine supplementation prevents hyperhomocysteinemia, oxidative stress and cancer-induced cachexia progression in Walker-256 tumor-bearing rats.

Science.gov (United States)

Deminice, Rafael; Cella, Paola Sanches; Padilha, Camila S; Borges, Fernando H; da Silva, Lilian Eslaine Costa Mendes; Campos-Ferraz, Patrícia L; Jordao, Alceu Afonso; Robinson, Jason Lorne; Bertolo, Robert F; Cecchini, Rubens; Guarnier, Flávia Alessandra

2016-08-01

The purpose of this study was to investigate (1) the impact of tumor growth on homocysteine (Hcy) metabolism, liver oxidative stress and cancer cachexia and, (2) the potential benefits of creatine supplementation in Walker-256 tumor-bearing rats. Three experiments were conducted. First, rats were killed on days 5 (D5), 10 (D10) and 14 (D14) after tumor implantation. In experiment 2, rats were randomly assigned to three groups designated as control (C), tumor-bearing (T) and tumor-bearing supplemented with creatine (TCr). A life span experiment was conducted as the third experiment. Creatine was supplied in drinking water for 21 days (8 g/L) in all cases. Tumor implantation consisted of a suspension of Walker-256 cells (8.0 × 10(7) cells in 0.5 mL of PBS). The progressive increase (P creatine supplementation promoted a 28 % reduction of tumor weight (P Creatine supplementation was unable to decrease Hcy concentration and to increase SAM/SAH ratio in tumor tissue. These data suggest that creatine effects on hepatic impaired Hcy metabolism promoted by tumor cell inoculation are responsible to decrease plasma Hcy in tumor-bearing rats. In conclusion, Walker-256 tumor growth is associated with progressive hyperhomocysteinemia, body weight loss and liver oxidative stress in rats. Creatine supplementation, however, prevented these tumor-associated perturbations.

Genetics Home Reference: X-linked creatine deficiency

Science.gov (United States)

... Health Conditions X-linked creatine deficiency X-linked creatine deficiency Printable PDF Open All Close All Enable ... view the expand/collapse boxes. Description X-linked creatine deficiency is an inherited disorder that primarily affects ...

X-linked creatine transporter deficiency: clinical aspects and pathophysiology

NARCIS (Netherlands)

van de Kamp, J.M.; Mancini, G.M.; Salomons, G.S.

2014-01-01

Creatine transporter deficiency was discovered in 2001 as an X-linked cause of intellectual disability characterized by cerebral creatine deficiency. This review describes the current knowledge regarding creatine metabolism, the creatine transporter and the clinical aspects of creatine transporter

Role of Creatine Supplementation on Exercise-Induced Cardiovascular Function and Oxidative Stress

Directory of Open Access Journals (Sweden)

Michael I. C. Kingsley

2009-01-01

Full Text Available Many degenerative diseases are associated with increased oxidative stress. Creatine has the potential to act as an indirect and direct antioxidant; however, limited data exist to evaluate the antioxidant capabilities of creatine supplementation within in vivo human systems. This study aimed to investigate the effects of oral creatine supplementation on markers of oxidative stress and antioxidant defenses following exhaustive cycling exercise. Following preliminary testing and two additional familiarization sessions, 18 active males repeated two exhaustive incremental cycling trials (T1 and T2 separated by exactly 7 days. The subjects were assigned, in a double-blind manner, to receive either 20 g of creatine (Cr or a placebo (P for the 5 days preceding T2. Breath-by-breath respiratory data and heart rate were continually recorded throughout the exercise protocol and blood samples were obtained at rest (preexercise, at the end of exercise (postexercise, and the day following exercise (post24 h. Serum hypdroperoxide concentrations were elevated at postexercise by 17 ± 5% above preexercise values (p = 0.030. However, supplementation did not influence lipid peroxidation (serum hypdroperoxide concentrations, resistance of low density lipoprotein to oxidative stress (t1/2max LDL oxidation and plasma concentrations of non-enzymatic antioxidants (retinol, α-carotene, β-carotene, α-tocopherol, γ-tocopherol, lycopene and vitamin C. Heart rate and oxygen uptake responses to exercise were not affected by supplementation. These findings suggest that short-term creatine supplementation does not enhance non-enzymatic antioxidant defence or protect against lipid peroxidation induced by exhaustive cycling in healthy males.

Beyond Muscles: The Untapped Potential of Creatine

OpenAIRE

Riesberg, Lisa A.; Weed, Stephanie A.; McDonald, Thomas L.; Eckerson, Joan M.; Drescher, Kristen M.

2016-01-01

Creatine is widely used by both elite and recreational athletes as an ergogenic aid to enhance anaerobic exercise performance. Older individuals also use creatine to prevent sarcopenia and, accordingly, may have therapeutic benefits for muscle wasting diseases. Although the effect of creatine on the musculoskeletal system has been extensively studied, less attention has been paid to its potential effects on other physiological systems. Because there is a significant pool of creatine in the br...

Creatine supplementation and swim performance: a brief review.

Science.gov (United States)

Hopwood, Melissa J; Graham, Kenneth; Rooney, Kieron B

2006-03-01

Nutritional supplements are popular among athletes participating in a wide variety of sports. Creatine is one of the most commonly used dietary supplements, as it has been shown to be beneficial in improving performance during repeated bouts of high-intensity anaerobic activity. This review examines the specific effects of creatine supplementation on swimming performance, and considers the effects of creatine supplementation on various measures of power development in this population. Research performed on the effect of creatine supplementation on swimming performance indicates that whilst creatine supplementation is ineffective in improving performance during a single sprint swim, dietary creatine supplementation may benefit repeated interval swim set performance. Considering the relationship between sprint swimming performance and measurements of power, the effect of creatine supplementation on power development in swimmers has also been examined. When measured on a swim bench ergometer, power development does show some improvement following a creatine supplementation regime. How this improvement in power output transfers to performance in the pool is uncertain. Although some evidence exists to suggest a gender effect on the performance improvements seen in swimmers following creatine supplementation, the majority of research indicates that male and female swimmers respond equally to supplementation. A major limitation to previous research is the lack of consideration given to the possible stroke dependant effect of creatine supplementation on swimming performance. The majority of the research conducted to date has involved examination of the freestyle swimming stroke only. The potential for performance improvements in the breaststroke and butterfly swimming strokes is discussed, with regards to the biomechanical differences and differences in efficiency between these strokes and freestyle. Key PointsCreatine supplementation does not improve single sprint

Hypoxia decreases creatine uptake in cardiomyocytes, while creatine supplementation enhances HIF activation.

Science.gov (United States)

Santacruz, Lucia; Arciniegas, Antonio Jose Luis; Darrabie, Marcus; Mantilla, Jose G; Baron, Rebecca M; Bowles, Dawn E; Mishra, Rajashree; Jacobs, Danny O

2017-08-01

Creatine (Cr), phosphocreatine (PCr), and creatine kinases (CK) comprise an energy shuttle linking ATP production in mitochondria with cellular consumption sites. Myocytes cannot synthesize Cr: these cells depend on uptake across the cell membrane by a specialized creatine transporter (CrT) to maintain intracellular Cr levels. Hypoxia interferes with energy metabolism, including the activity of the creatine energy shuttle, and therefore affects intracellular ATP and PCr levels. Here, we report that exposing cultured cardiomyocytes to low oxygen levels rapidly diminishes Cr transport by decreasing V max and K m Pharmacological activation of AMP-activated kinase (AMPK) abrogated the reduction in Cr transport caused by hypoxia. Cr supplementation increases ATP and PCr content in cardiomyocytes subjected to hypoxia, while also significantly augmenting the cellular adaptive response to hypoxia mediated by HIF-1 activation. Our results indicate that: (1) hypoxia reduces Cr transport in cardiomyocytes in culture, (2) the cytoprotective effects of Cr supplementation are related to enhanced adaptive physiological responses to hypoxia mediated by HIF-1, and (3) Cr supplementation increases the cellular ATP and PCr content in RNCMs exposed to hypoxia. © 2017 The Authors. Physiological Reports published by Wiley Periodicals, Inc. on behalf of The Physiological Society and the American Physiological Society.

The use of creatine supplements in the military.

Science.gov (United States)

Havenetidis, Konstantinos

2016-08-01

Creatine is considered an effective nutritional ergogenic aid to enhance exercise performance. In spite of the publication of several reviews in the last decade on the topic of exercise performance/sports and creatine there is a need for an update related to the military given the lack of information in this area. The aim of this study was to critically assess original research addressing the use of creatine supplements in the military. A search of the electronic databases PubMed and SPORTDiscus, for the following key words: military personnel, trainees, recruit, soldier, physical fitness, physical conditioning, creatine supplementation, creatine ingestion, nutritional supplements to identify surveys and randomised clinical trials from journal articles and technical reports investigating the effect of creatine supplementation on military populations. Thirty-three out of 90 articles examined the use of creatine as a dietary supplement in military personnel. Twenty-one studies were finally selected on the basis of stated inclusion criteria for military surveys and randomised clinical trials. Most of the surveys (15/17) in the military indicate a high popularity of creatine (average 27%) among supplement users. In contrast, in most of the exercise protocols used (6/9) during randomised clinical trials creatine has produced a non-significant performance-enhancing effect. Creatine is one of the most widely used supplemental compounds in the military. It is not considered a doping infraction or related to any adverse health effects but its long-term usage needs further investigation. Experimental research suggests that creatine supplementation does not enhance physical performance in the military. However, limitations in creatine dosage, military fitness testing and sample group selection might have underestimated the ergogenic properties of creatine. Recent studies also indicate positive effects on various aspects of total force fitness such as cognitive

A buffered form of creatine does not promote greater changes in muscle creatine content, body composition, or training adaptations than creatine monohydrate

Directory of Open Access Journals (Sweden)

Jagim Andrew R

2012-09-01

Full Text Available Abstract Background Creatine monohydrate (CrM has been consistently reported to increase muscle creatine content and improve high-intensity exercise capacity. However, a number of different forms of creatine have been purported to be more efficacious than CrM. The purpose of this study was to determine if a buffered creatine monohydrate (KA that has been purported to promote greater creatine retention and training adaptations with fewer side effects at lower doses is more efficacious than CrM supplementation in resistance-trained individuals. Methods In a double-blind manner, 36 resistance-trained participants (20.2 ± 2 years, 181 ± 7 cm, 82.1 ± 12 kg, and 14.7 ± 5% body fat were randomly assigned to supplement their diet with CrM (Creapure® AlzChem AG, Trostberg, Germany at normal loading (4 x 5 g/d for 7-days and maintenance (5 g/d for 21-days doses; KA (Kre-Alkalyn®, All American Pharmaceutical, Billings, MT, USA at manufacturer’s recommended doses (KA-L, 1.5 g/d for 28-days; or, KA with equivalent loading (4 x 5 g/d for 7-days and maintenance (5 g/d doses of CrM (KA-H. Participants were asked to maintain their current training programs and record all workouts. Muscle biopsies from the vastus lateralis, fasting blood samples, body weight, DEXA determined body composition, and Wingate Anaerobic Capacity (WAC tests were performed at 0, 7, and 28-days while 1RM strength tests were performed at 0 and 28-days. Data were analyzed by a repeated measures multivariate analysis of variance (MANOVA and are presented as mean ± SD changes from baseline after 7 and 28-days, respectively. Results Muscle free creatine content obtained in a subgroup of 25 participants increased in all groups over time (1.4 ± 20.7 and 11.9 ± 24.0 mmol/kg DW, p = 0.03 after 7 and 28-days, respectively, with no significant differences among groups (KA-L −7.9 ± 22.3, 4.7 ± 27.0; KA-H 1.0 ± 12.8, 9.1�

A buffered form of creatine does not promote greater changes in muscle creatine content, body composition, or training adaptations than creatine monohydrate.

Science.gov (United States)

Jagim, Andrew R; Oliver, Jonathan M; Sanchez, Adam; Galvan, Elfego; Fluckey, James; Riechman, Steven; Greenwood, Michael; Kelly, Katherine; Meininger, Cynthia; Rasmussen, Christopher; Kreider, Richard B

2012-09-13

Creatine monohydrate (CrM) has been consistently reported to increase muscle creatine content and improve high-intensity exercise capacity. However, a number of different forms of creatine have been purported to be more efficacious than CrM. The purpose of this study was to determine if a buffered creatine monohydrate (KA) that has been purported to promote greater creatine retention and training adaptations with fewer side effects at lower doses is more efficacious than CrM supplementation in resistance-trained individuals. In a double-blind manner, 36 resistance-trained participants (20.2 ± 2 years, 181 ± 7 cm, 82.1 ± 12 kg, and 14.7 ± 5% body fat) were randomly assigned to supplement their diet with CrM (Creapure® AlzChem AG, Trostberg, Germany) at normal loading (4 x 5 g/d for 7-days) and maintenance (5 g/d for 21-days) doses; KA (Kre-Alkalyn®, All American Pharmaceutical, Billings, MT, USA) at manufacturer's recommended doses (KA-L, 1.5 g/d for 28-days); or, KA with equivalent loading (4 x 5 g/d for 7-days) and maintenance (5 g/d) doses of CrM (KA-H). Participants were asked to maintain their current training programs and record all workouts. Muscle biopsies from the vastus lateralis, fasting blood samples, body weight, DEXA determined body composition, and Wingate Anaerobic Capacity (WAC) tests were performed at 0, 7, and 28-days while 1RM strength tests were performed at 0 and 28-days. Data were analyzed by a repeated measures multivariate analysis of variance (MANOVA) and are presented as mean ± SD changes from baseline after 7 and 28-days, respectively. Muscle free creatine content obtained in a subgroup of 25 participants increased in all groups over time (1.4 ± 20.7 and 11.9 ± 24.0 mmol/kg DW, p = 0.03) after 7 and 28-days, respectively, with no significant differences among groups (KA-L -7.9 ± 22.3, 4.7 ± 27.0; KA-H 1.0 ± 12.8, 9.1 ± 23.2; CrM 11.3 ± 23.9, 22.3 ± 21

CREATINE SUPPLEMENTATION AND SWIM PERFORMANCE: A BRIEF REVIEW

Directory of Open Access Journals (Sweden)

Melissa J. Hopwood

2006-03-01

Full Text Available Nutritional supplements are popular among athletes participating in a wide variety of sports. Creatine is one of the most commonly used dietary supplements, as it has been shown to be beneficial in improving performance during repeated bouts of high-intensity anaerobic activity. This review examines the specific effects of creatine supplementation on swimming performance, and considers the effects of creatine supplementation on various measures of power development in this population. Research performed on the effect of creatine supplementation on swimming performance indicates that whilst creatine supplementation is ineffective in improving performance during a single sprint swim, dietary creatine supplementation may benefit repeated interval swim set performance. Considering the relationship between sprint swimming performance and measurements of power, the effect of creatine supplementation on power development in swimmers has also been examined. When measured on a swim bench ergometer, power development does show some improvement following a creatine supplementation regime. How this improvement in power output transfers to performance in the pool is uncertain. Although some evidence exists to suggest a gender effect on the performance improvements seen in swimmers following creatine supplementation, the majority of research indicates that male and female swimmers respond equally to supplementation. A major limitation to previous research is the lack of consideration given to the possible stroke dependant effect of creatine supplementation on swimming performance. The majority of the research conducted to date has involved examination of the freestyle swimming stroke only. The potential for performance improvements in the breaststroke and butterfly swimming strokes is discussed, with regards to the biomechanical differences and differences in efficiency between these strokes and freestyle

Creatine kinase and creatine kinase subunit-B in coronary sinus blood in pacing-induced angina pectoris

DEFF Research Database (Denmark)

Bagger, J P; Ingerslev, J; Heinsvig, E M

1982-01-01

In nine out of 10 patients with angiographic documented coronary artery disease, pacing-induced angina pectoris provoked myocardial production of lactate, whereas no significant release of either creatine kinase or creatine kinase subunit-B to coronary sinus and peripheral venous blood could...

X-Linked Creatine Transporter Deficiency Presenting as a Mitochondrial Disorder

NARCIS (Netherlands)

Hathaway, S.C.; Friez, M.; Limbo, K.; Parker, C.; Salomons, G.S.; Vockley, J.; Wood, T.; Abdul-Rahman, O.A.

2010-01-01

X-linked creatine transporter defect is caused by mutations in SLC6A8 at Xq28, which encodes the sodium-dependent creatine transporter. Reduction in creatine uptake results in elevated urine creatine and CSF creatine deficiency, which can be detected on magnetic resonance spectroscopy. We report a

Effects of creatine supplementation on exercise performance.

Science.gov (United States)

Demant, T W; Rhodes, E C

1999-07-01

While creatine has been known to man since 1835, when a French scientist reported finding this constitutent of meat, its presence in athletics as a performance enhancer is relatively new. Amid claims of increased power and strength, decreased performance time and increased muscle mass, creatine is being hailed as a true ergogenic aid. Creatinine is synthesised from the amino acids glycine, arginine and methionine in the kidneys, liver and pancreas, and is predominantly found in skeletal muscle, where it exists in 2 forms. Approximately 40% is in the free creatine form (Crfree), while the remaining 60% is in the phosphorylated form, creatine phosphate (CP). The daily turnover rate of approximately 2 g per day is equally met via exogenous intake and endogenous synthesis. Although creatine concentration (Cr) is greater in fast twitch muscle fibres, slow twitch fibres have a greater resynthesis capability due to their increased aerobic capacity. There appears to be no significant difference between males and females in Cr, and training does not appear to effect Cr. The 4 roles in which creatine is involved during performance are temporal energy buffering, spatial energy buffering, proton buffering and glycolysis regulation. Creatine supplementation of 20 g per day for at least 3 days has resulted in significant increases in total Cr for some individuals but not others, suggesting that there are 'responders' and 'nonresponders'. These increases in total concentration among responders is greatest in individuals who have the lowest initial total Cr, such as vegetarians. Increased concentrations of both Crfree and CP are believed to aid performance by providing more short term energy, as well as increase the rate of resynthesis during rest intervals. Creatine supplementation does not appear to aid endurance and incremental type exercises, and may even be detrimental. Studies investigating the effects of creatine supplementation on short term, high intensity exercises have

Impedance Mismatch study between the Microwave Generator and the PUPR Plasma Machine

International Nuclear Information System (INIS)

Gaudier, Jorge R.; Castellanos, Ligeia; Encarnacion, Kabir; Zavala, Natyaliz; Rivera, Ramon; Farahat, Nader; Leal, Edberto

2006-01-01

Impedance mismatch inside the connection from the microwave power generator to the plasma machine is studied. A magnetron power generator transmits microwaves of 2.45 GHz and variable power from 50W to 5000W, through a flexible rectangular waveguide to heat plasma inside a Mirror Cusp devise located at the Polytechnic University of Puerto Rico. Before the production of plasma, the residual gas of the devise must be extracted by a vacuum system (5Torr or better), then Argon gas is injected to the machine. The microwaves heat the Argon ions to initiate ionization and plasma is produced. A dielectric wall is used inside the rectangular waveguide to isolate the plasma machine and maintain vacuum. Even though the dielectric will not block the wave propagation, some absorption of microwaves will occur. This absorption will cause reflection, reducing the efficiency of the power transfer. Typically a thin layer of Teflon is used, but measurements using this dielectric show a significant reflection of power back to the generator. Due to the high-power nature of the generator (5KW), this mismatch is not desirable. An electromagnetic field solver based on the Finite Difference Time Domain Method(FDTD) is used to model the rectangular waveguide connection. The characteristic impedance of the simulation is compared with the analytical formula expression and a good agreement is obtain. Furthermore the Teflon-loaded guide is modeled using the above program and the input impedance is computed. The reflection coefficient is calculated based on the transmission line theory with the characteristic and input impedances. Based on the simulation results it is possible to optimize the thickness, shape and dielectric constant of the material, in order to seal the connection with a better match

Plasma heating in multiple-resonance excitation of a plasma in a mirror machine

Energy Technology Data Exchange (ETDEWEB)

Bender, A; Siambis, J G [Carnegie-Mellon Univ., Pittsburgh, Pa. (USA)

1976-06-01

By applying 1 kW of microwave power at 2.45 GHz and 1 kW of r.f. power in the frequency range of 4-25 MHz at one end of a mirror machine, where neutral hydrogen gas is injected in a pulsed mode, a plasma density of 2 x 10/sup 11/cm/sup -3/ with an electron temperature of 60 eV and ion temperature of 40 eV is generated. The ion heating mechanism, is, principally, collisional thermalization of the applied r.f. power, via coupling to and excitation of the low frequency resonances of the plasma column, in agreement with the theoretical prediction for the case of high total effective collision frequency for momentum transfer for the electrons.

Creatine and the Liver: Metabolism and Possible Interactions.

Science.gov (United States)

Barcelos, R P; Stefanello, S T; Mauriz, J L; Gonzalez-Gallego, J; Soares, F A A

2016-01-01

The process of creatine synthesis occurs in two steps, catalyzed by L-arginine:glycine amidinotransferase (AGAT) and guanidinoacetate N-methyltransferase (GAMT), which take place mainly in kidney and liver, respectively. This molecule plays an important energy/pH buffer function in tissues, and to guarantee the maintenance of its total body pool, the lost creatine must be replaced from diet or de novo synthesis. Creatine administration is known to decrease the consumption of Sadenosyl methionine and also reduce the homocysteine production in liver, diminishing fat accumulation and resulting in beneficial effects in fatty liver and non-alcoholic liver disease. Different studies have shown that creatine supplementation could supply brain energy, presenting neuroprotective effects against the encephalopathy induced by hyperammonemia in acute liver failure. Creatine is also taken by many athletes for its ergogenic properties. However, little is known about the adverse effects of creatine supplementation, which are barely described in the literature, with reports of mainly hypothetical effects arising from a small number of scientific publications. Antioxidant effects have been found in several studies, although one of the theories regarding the potential for toxicity from creatine supplementation is that it can increase oxidative stress and potentially form carcinogenic compounds.

Scientific basis and practical aspects of creatine supplementation for athletes.

Science.gov (United States)

Volek, Jeff S; Rawson, Eric S

2004-01-01

A large number of studies have been published on creatine supplementation over the last decade. Many studies show that creatine supplementation in conjunction with resistance training augments gains in muscle strength and size. The underlying physiological mechanism(s) to explain this ergogenic effect remain unclear. Increases in muscle fiber hypertrophy and myosin heavy chain expression have been observed with creatine supplementation. Creatine supplementation increases acute weightlifting performance and training volume, which may allow for greater overload and adaptations to training. Creatine supplementation may also induce a cellular swelling in muscle cells, which in turn may affect carbohydrate and protein metabolism. Several studies point to the conclusion that elevated intramuscular creatine can enhance glycogen levels but an effect on protein synthesis/degradation has not been consistently detected. As expected there is a distribution of responses to creatine supplementation that can be largely explained by the degree of creatine uptake into muscle. Thus, there is wide interest in methods to maximize muscle creatine levels. A carbohydrate or carbohydrate/protein-induced insulin response appears to benefit creatine uptake. In summary, the predominance of research indicates that creatine supplementation represents a safe, effective, and legal method to enhance muscle size and strength responses to resistance training.

Creatine and Caffeine: Considerations for Concurrent Supplementation.

Science.gov (United States)

Trexler, Eric T; Smith-Ryan, Abbie E

2015-12-01

Nutritional supplementation is a common practice among athletes, with creatine and caffeine among the most commonly used ergogenic aids. Hundreds of studies have investigated the ergogenic potential of creatine supplementation, with consistent improvements in strength and power reported for exercise bouts of short duration (≤ 30 s) and high intensity. Caffeine has been shown to improve endurance exercise performance, but results are mixed in the context of strength and sprint performance. Further, there is conflicting evidence from studies comparing the ergogenic effects of coffee and caffeine anhydrous supplementation. Previous research has identified independent mechanisms by which creatine and caffeine may improve strength and sprint performance, leading to the formulation of multi-ingredient supplements containing both ingredients. Although scarce, research has suggested that caffeine ingestion may blunt the ergogenic effect of creatine. While a pharmacokinetic interaction is unlikely, authors have suggested that this effect may be explained by opposing effects on muscle relaxation time or gastrointestinal side effects from simultaneous consumption. The current review aims to evaluate the ergogenic potential of creatine and caffeine in the context of high-intensity exercise. Research directly comparing coffee and caffeine anhydrous is discussed, along with previous studies evaluating the concurrent supplementation of creatine and caffeine.

Side effects of creatine supplementation in athletes.

OpenAIRE

Francaux, Marc; Poortmans, Jacques R

2006-01-01

Context: Allegations about side effects of creatine supplementation by athletes have been published in the popular media and scientific publications. Purpose: To examine the experimental evidence relating to the physiological effects of creatine supplementation. Results: One of the purported effects of oral creatine supplementation is increased muscle mass. A review of the literature reveals a 1.0% to 2.3% increase in body mass, which is attributed to fat-free mass and, more specifically, to ...

Creatine biosynthesis and transport by the term human placenta.

Science.gov (United States)

Ellery, Stacey J; Della Gatta, Paul A; Bruce, Clinton R; Kowalski, Greg M; Davies-Tuck, Miranda; Mockler, Joanne C; Murthi, Padma; Walker, David W; Snow, Rod J; Dickinson, Hayley

2017-04-01

Creatine is an amino acid derivative that is involved in preserving ATP homeostasis. Previous studies suggest an important role for the creatine kinase circuit for placental ATP turnover. Creatine is obtained from both the diet and endogenous synthesis, usually along the renal-hepatic axis. However, some tissues with a high-energy demand have an inherent capacity to synthesise creatine. In this study, we determined if the term human placenta has the enzymatic machinary to synthesise creatine. Eleven placentae were collected following elective term caesarean section. Samples from the 4 quadrants of each placenta were either fixed in formalin or frozen. qPCR was used to determine the mRNA expression of the creatine synthesising enzymes arginine:glycine amidinotransferase (AGAT) and guanidinoacetate methyltransferase (GAMT), and the creatine transporter (SLC6A8). Protein expression of AGAT and GAMT was quantified by Western blot, and observations of cell localisation of AGAT, GAMT and SLC6A8 made with immunohistochemistry. Synthesis of guanidinoacetate (GAA; creatine precursor) and creatine in placental homogenates was determined via GC-MS and HPLC, respectively. AGAT, GAMT and SLC6A8 mRNA and protein were detected in the human placenta. AGAT staining was identified in stromal and endothelial cells of the fetal capillaries. GAMT and SLC6A8 staining was localised to the syncytiotrophoblast of the fetal villi. Ex vivo, tissue homogenates produce both GAA (4.6 nmol mg protein -1 h -1 ) and creatine (52.8 nmol mg protein -1 h -1 ). The term human placenta has the capacity to synthesise creatine. These data present a new understanding of placental energy metabolism. Copyright © 2017 Elsevier Ltd. All rights reserved.

Disturbed energy metabolism and muscular dystrophy caused by pure creatine deficiency are reversible by creatine intake

Science.gov (United States)

Nabuurs, C I; Choe, C U; Veltien, A; Kan, H E; van Loon, L J C; Rodenburg, R J T; Matschke, J; Wieringa, B; Kemp, G J; Isbrandt, D; Heerschap, A

2013-01-01

Creatine (Cr) plays an important role in muscle energy homeostasis by its participation in the ATP–phosphocreatine phosphoryl exchange reaction mediated by creatine kinase. Given that the consequences of Cr depletion are incompletely understood, we assessed the morphological, metabolic and functional consequences of systemic depletion on skeletal muscle in a mouse model with deficiency of l-arginine:glycine amidinotransferase (AGAT−/−), which catalyses the first step of Cr biosynthesis. In vivo magnetic resonance spectroscopy showed a near-complete absence of Cr and phosphocreatine in resting hindlimb muscle of AGAT−/− mice. Compared with wild-type, the inorganic phosphate/β-ATP ratio was increased fourfold, while ATP levels were reduced by nearly half. Activities of proton-pumping respiratory chain enzymes were reduced, whereas F1F0-ATPase activity and overall mitochondrial content were increased. The Cr-deficient AGAT−/− mice had a reduced grip strength and suffered from severe muscle atrophy. Electron microscopy revealed increased amounts of intramyocellular lipid droplets and crystal formation within mitochondria of AGAT−/− muscle fibres. Ischaemia resulted in exacerbation of the decrease of pH and increased glycolytic ATP synthesis. Oral Cr administration led to rapid accumulation in skeletal muscle (faster than in brain) and reversed all the muscle abnormalities, revealing that the condition of the AGAT−/− mice can be switched between Cr deficient and normal simply by dietary manipulation. Systemic creatine depletion results in mitochondrial dysfunction and intracellular energy deficiency, as well as structural and physiological abnormalities. The consequences of AGAT deficiency are more pronounced than those of muscle-specific creatine kinase deficiency, which suggests a multifaceted involvement of creatine in muscle energy homeostasis in addition to its role in the phosphocreatine–creatine kinase system. PMID:23129796

Proton NMR studies of creatine in human erythrocytes

Energy Technology Data Exchange (ETDEWEB)

Kuchel, P W; Chapman, B E [Sydney Univ. (Australia). Dept. of Biochemistry

1983-09-01

Proton spin-echo nuclear magnetic resonance spectroscopy was used to measure the relative levels of some metabolites in intact human erythrocytes that had been fractionated by density gradient centrifugation. Age dependent changes in the concentrations of free glycine, choline and ergothioneine were seen for the first time, while glutathione was essentially invariant. In addition, there was a 10-fold decrease in creatine levels from the youngest to oldest cells. This confirms earlier reports and provides a simple explanation for the variable creatine resonance intensities seen in spectra obtained from different erythrocyte samples prepared from the same donor. The different chemical shifts of the methylene resonances of creatine and creatine phosphate was demonstrated and hence confirmed that the bulk of the creatine in intact erythrocytes is not phosphorylated. The chemical shift difference enabled the monitoring of the creatine phosphokinase catalysed reaction in lysates to which the rabbit muscle enzyme had been added. This experiment indicated that the enzyme is not significantly inhibited by factors in the lysates, and introduced a new means of assaying the in situ activity of the enzyme.

Proton NMR studies of creatine in human erythrocytes

International Nuclear Information System (INIS)

Kuchel, P.W.; Chapman, B.E.

1983-01-01

Proton spin-echo nuclear magnetic resonance spectroscopy was used to measure the relative levels of some metabolites in intact human erythrocytes that had been fractionated by density gradient centrifugation. Age dependent changes in the concentrations of free glycine, choline and ergothioneine were seen for the first time, while glutathione was essentially invariant. In addition, there was a 10-fold decrease in creatine levels from the youngest to oldest cells. This confirms earlier reports and provides a simple explanation for the variable creatine resonance intensities seen in spectra obtained from different erythrocyte samples prepared from the same donor. The different chemical shifts of the methylene resonances of creatine and creatine phosphate was demonstrated and hence confirmed that the bulk of the creatine in intact erythrocytes is not phosphorylated. The chemical shift difference enabled the monitoring of the creatine phosphokinase catalysed reaction in lysates to which the rabbit muscle enzyme had been added. This experiment indicated that the enzyme is not significantly inhibited by factors in the lysates, and introduced a new means of assaying the in situ activity of the enzyme. (author)

Two-site immunoradiometric assay for the MB isoenzyme of creatine kinase

Energy Technology Data Exchange (ETDEWEB)

Willson, V J.C.; Jones, H M; Thompson, R J [Cambridge Univ. (UK). Clinical School

1981-06-18

A two-site immunoradiometric assay for myocardial creatine kinase MB isoenzyme is described. The method utilizes immobilized anti-human creatine kinase BB antibodies and /sup 125/I-labelled anti-human creatine kinase MM antibodies and can specifically detect creatine kinase MB in the presence of approximately 1000-fold excess of creatine kinase MM or BB. Native kinase MB prepared from human heart and creatine kinase MB prepared by hybridisation of purified human creatine kinase MM and creatine kinase BB appeared to react identically in the assay. Serum estimations on patients with suspected myocardial infarction correlated with the presence of MB band on electrophoresis but preliminary results suggest that the two-site immunoradiometric assay may be more sensitive.

Creatine and creatine analogues in hypertension and cardiovascular disease

NARCIS (Netherlands)

Horjus, Deborah L.; Oudman, Inge; van Montfrans, Gert A.; Brewster, Lizzy M.

2011-01-01

The creatine kinase system, the central regulatory system of cellular energy metabolism, provides ATP in situ at ATP-ases involved in ion transport and muscle contraction. Furthermore, the enzyme system provides relative protection from tissue ischaemia and acidosis. The system could therefore be a

Creatine and guanidinoacetate reference values in a French population

NARCIS (Netherlands)

Joncquel-Cheval Curt, M.; Cheillan, D.; Briand, G.; Salomons, G.S.; Mention-Mulliez, K.; Dobbelaere, D.; Cuisset, J.M.; Lion-Francois, L.; Portes, V.D.; Chabli, A.; Valayannopoulos, V.; Benoist, J.F.; Pinard, J.M.; Simard, G.; Douay, O.; Deiva, K.; Tardieu, M.; Afenjar, A.; Heron, D.; Rivier, F.; Chabrol, B.; Prieur, F.; Cartault, F.; Pitelet, G.; Goldenberg, A.; Bekri, S.; Gerard, M.; Delorme, R.; Porchet, N.; Vianey-Saban, C.; Vamecq, J.

2013-01-01

Creatine and guanidinoacetate are biomarkers of creatine metabolism. Their assays in body fluids may be used for detecting patients with primary creatine deficiency disorders (PCDD), a class of inherited diseases. Their laboratory values in blood and urine may vary with age, requiring that reference

Creatine supplementation and glycemic control: a systematic review.

Science.gov (United States)

Pinto, Camila Lemos; Botelho, Patrícia Borges; Pimentel, Gustavo Duarte; Campos-Ferraz, Patrícia Lopes; Mota, João Felipe

2016-09-01

The focus of this review is the effects of creatine supplementation with or without exercise on glucose metabolism. A comprehensive examination of the past 16 years of study within the field provided a distillation of key data. Both in animal and human studies, creatine supplementation together with exercise training demonstrated greater beneficial effects on glucose metabolism; creatine supplementation itself demonstrated positive results in only a few of the studies. In the animal studies, the effects of creatine supplementation on glucose metabolism were even more distinct, and caution is needed in extrapolating these data to different species, especially to humans. Regarding human studies, considering the samples characteristics, the findings cannot be extrapolated to patients who have poorer glycemic control, are older, are on a different pharmacological treatment (e.g., exogenous insulin therapy) or are physically inactive. Thus, creatine supplementation is a possible nutritional therapy adjuvant with hypoglycemic effects, particularly when used in conjunction with exercise.

Creatine, energetic function, metabolism and supplementation effects on sports

Directory of Open Access Journals (Sweden)

Emerson Gimenes Bernardo da Silva

2008-06-01

Full Text Available The purpose of this work is to review the literature regarding creatine ingestion by athletes and physical activity enthusiasts, discussing its necessity and, if possible, predicting some consequences. In order to achieve this purpose it was necessary to study the relationship between the muscles energetic system and their regulation. It was also proved necessary to investigate the creatine cycle, its endogenous origin, its metabolizing and conversion into creatine-phosphate. A bibliography was used to collect information about the subject. The research lead to the following conclusions: diet supplementation with creatine leads to increased phosphocreatine levels in human muscles. However, new in vivo experiments are most desirable, because it is already known that creatine interferes with the regulation of some metabolic pathways.

Can creatine supplementation form carcinogenic heterocyclic amines in humans?

Science.gov (United States)

Pereira, Renato Tavares dos Santos; Dörr, Felipe Augusto; Pinto, Ernani; Solis, Marina Yazigi; Artioli, Guilherme Giannini; Fernandes, Alan Lins; Murai, Igor Hisashi; Dantas, Wagner Silva; Seguro, Antônio Carlos; Santinho, Mirela Aparecida Rodrigues; Roschel, Hamilton; Carpentier, Alain; Poortmans, Jacques Remi; Gualano, Bruno

2015-01-01

Abstract Creatine supplementation has been associated with increased cancer risk. In fact, there is evidence indicating that creatine and/or creatinine are important precursors of carcinogenic heterocyclic amines (HCAs). The present study aimed to investigate the acute and chronic effects of low- and high-dose creatine supplementation on the production of HCAs in healthy humans (i.e. 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP), 2-amino-3,8-dimethylimidazo[4,5-f]quinoxaline (8-MeIQx),  2-amino-(1,6-dimethylfuro[3,2-e]imidazo[4,5-b])pyridine (IFP) and 2-amino-3,4,8-trimethylimidazo[4,5-f]quinoxaline (4,8-DiMeIQx)). This was a non-counterbalanced single-blind crossover study divided into two phases, in which low- and high-dose creatine protocols were tested. After acute (1 day) and chronic supplementation (30 days), the HCAs PhIP, 8-MeIQx, IFP and 4,8-DiMeIQx were assessed through a newly developed HPLC–MS/MS method. Dietary HCA intake and blood and urinary creatinine were also evaluated. Out of 576 assessments performed (from 149 urine samples), only nine (3 from creatine and 6 from placebo) showed quantifiable levels of HCAs (8-MeIQx: n = 3; 4,8-DiMeIQx: n = 2; PhIP: n = 4). Individual analyses revealed that diet rather than creatine supplementation was the main responsible factor for HCA formation in these cases. This study provides compelling evidence that both low and high doses of creatine supplementation, given either acutely or chronically, did not cause increases in the carcinogenic HCAs PhIP, 8-MeIQx, IFP and 4,8-DiMeIQx in healthy subjects. These findings challenge the long-existing notion that creatine supplementation could potentially increase the risk of cancer by stimulating the formation of these mutagens. Key points There is a long-standing concern that creatine supplementation could be associated with cancer, possibly by facilitating the formation of carcinogenic heterocyclic amines (HCAs). This study provides compelling evidence

Treatment by oral creatine, L-arginine and L-glycine in six severely affected patients with creatine transporter defect

NARCIS (Netherlands)

Valayannopoulos, V.; Boddaert, N.; Chabli, A.; Barbier, V.; Desguerre, I.; Philippe, A.; Afenjar, A.; Mazzuca, M.; Cheillan, D.; Munnich, A.; de Keyzer, Y.; Jakobs, C.A.J.M.; Salomons, G.S.; de Lonlay, P.

2012-01-01

Background X-linked cerebral creatine deficiency is caused by the deficiency of the creatine transporter (CTP) encoded by the SLC6A8 gene. Patients and Methods We report here a series of six patients with severe CTP deficiency, four males and two females; clinical presentations include mild to

A two-site immunoradiometric assay for the MB isoenzyme of creatine kinase

International Nuclear Information System (INIS)

Willson, V.J.C.; Jones, H.M.; Thompson, R.J.

1981-01-01

A two-site immunoradiometric assay for myocardial creatine kinase MB isoenzyme is described. The method utilizes immobilized anti-human creatine kinase BB antibodies and 125 I-labelled anti-human creatine kinase MM antibodies and can specifically detect creatine kinase MB in the presence of approximately 1000-fold excess of creatine kinase MM or BB. Native kinase MB prepared from human heart and creatine kinase MB prepared by hybridisation of purified human creatine kinase MM and creatine kinase BB appeared to react identically in the assay. Serum estimations on patients with suspected myocardial infarction correlated with the presence of MB band on electrophoresis but preliminary results suggest that the two-site immunoradiometric assay may be more sensitive. (Auth.)

Creatine pretreatment protects cortical axons from energy depletion in vitro

Science.gov (United States)

Shen, Hua; Goldberg, Mark P.

2012-01-01

Creatine is a natural nitrogenous guanidino compound involved in bioenergy metabolism. Although creatine has been shown to protect neurons of the central nervous system (CNS) from experimental hypoxia/ischemia, it remains unclear if creatine may also protect CNS axons, and if the potential axonal protection depends on glial cells. To evaluate the direct impact of creatine on CNS axons, cortical axons were cultured in a separate compartment from their somas and proximal neurites using a modified two-compartment culture device. Axons in the axon compartment were subjected to acute energy depletion, an in vitro model of white matter ischemia, by exposure to 6 mM sodium azide for 30 min in the absence of glucose and pyruvate. Energy depletion reduced axonal ATP by 65%, depolarized axonal resting potential, and damaged 75% of axons. Application of creatine (10 mM) to both compartments of the culture at 24 h prior to energy depletion significantly reduced axonal damage by 50%. In line with the role of creatine in the bioenergy metabolism, this application also alleviated the axonal ATP loss and depolarization. Inhibition of axonal depolarization by blocking sodium influx with tetrodotoxin also effectively reduced the axonal damage caused by energy depletion. Further study revealed that the creatine effect was independent of glial cells, as axonal protection was sustained even when creatine was applied only to the axon compartment (free from somas and glial cells) for as little as 2 h. In contrast, application of creatine after energy depletion did not protect axons. The data provide the first evidence that creatine pretreatment may directly protect CNS axons from energy deficiency. PMID:22521466

Creatine Enhances Mitochondrial-Mediated Oligodendrocyte Survival After Demyelinating Injury.

Science.gov (United States)

Chamberlain, Kelly A; Chapey, Kristen S; Nanescu, Sonia E; Huang, Jeffrey K

2017-02-08

Chronic oligodendrocyte loss, which occurs in the demyelinating disorder multiple sclerosis (MS), contributes to axonal dysfunction and neurodegeneration. Current therapies are able to reduce MS severity, but do not prevent transition into the progressive phase of the disease, which is characterized by chronic neurodegeneration. Therefore, pharmacological compounds that promote oligodendrocyte survival could be beneficial for neuroprotection in MS. Here, we investigated the role of creatine, an organic acid involved in adenosine triphosphate (ATP) buffering, in oligodendrocyte function. We found that creatine increased mitochondrial ATP production directly in oligodendrocyte lineage cell cultures and exerted robust protection on oligodendrocytes by preventing cell death in both naive and lipopolysaccharide-treated mixed glia. Moreover, lysolecithin-mediated demyelination in mice deficient in the creatine-synthesizing enzyme guanidinoacetate-methyltransferase ( Gamt ) did not affect oligodendrocyte precursor cell recruitment, but resulted in exacerbated apoptosis of regenerated oligodendrocytes in central nervous system (CNS) lesions. Remarkably, creatine administration into Gamt -deficient and wild-type mice with demyelinating injury reduced oligodendrocyte apoptosis, thereby increasing oligodendrocyte density and myelin basic protein staining in CNS lesions. We found that creatine did not affect the recruitment of macrophages/microglia into lesions, suggesting that creatine affects oligodendrocyte survival independently of inflammation. Together, our results demonstrate a novel function for creatine in promoting oligodendrocyte viability during CNS remyelination. SIGNIFICANCE STATEMENT We report that creatine enhances oligodendrocyte mitochondrial function and protects against caspase-dependent oligodendrocyte apoptosis during CNS remyelination. This work has important implications for the development of therapeutic targets for diseases characterized by

Creatine supplementation with specific view to exercise/sports performance: an update

Directory of Open Access Journals (Sweden)

Cooper Robert

2012-07-01

Full Text Available Abstract Creatine is one of the most popular and widely researched natural supplements. The majority of studies have focused on the effects of creatine monohydrate on performance and health; however, many other forms of creatine exist and are commercially available in the sports nutrition/supplement market. Regardless of the form, supplementation with creatine has regularly shown to increase strength, fat free mass, and muscle morphology with concurrent heavy resistance training more than resistance training alone. Creatine may be of benefit in other modes of exercise such as high-intensity sprints or endurance training. However, it appears that the effects of creatine diminish as the length of time spent exercising increases. Even though not all individuals respond similarly to creatine supplementation, it is generally accepted that its supplementation increases creatine storage and promotes a faster regeneration of adenosine triphosphate between high intensity exercises. These improved outcomes will increase performance and promote greater training adaptations. More recent research suggests that creatine supplementation in amounts of 0.1 g/kg of body weight combined with resistance training improves training adaptations at a cellular and sub-cellular level. Finally, although presently ingesting creatine as an oral supplement is considered safe and ethical, the perception of safety cannot be guaranteed, especially when administered for long period of time to different populations (athletes, sedentary, patient, active, young or elderly.

The Effect of Direct Current Transthoracic Countershock on Human Myocardial Cells Evidenced by Creatine Kinase and Lactic Dehydrogenase Isoenzymes.

Science.gov (United States)

1986-05-01

however, fractionation of these enzymes will identify their specific source. Plasma levels of CK isoenzymes (CKMB) and LDH isoenzymes ( LDHI ) are most...damage--inferred by isoenzyme levels of CKMB and/or LDHI in the serum above normal levels (see definitions of creatine kinase and lactic dehydrogenase

Creatine kinase activity is associated with blood pressure

NARCIS (Netherlands)

Brewster, Lizzy M.; Mairuhu, Gideon; Bindraban, Navin R.; Koopmans, Richard P.; Clark, Joseph F.; van Montfrans, Gert A.

2006-01-01

BACKGROUND: We previously hypothesized that high activity of creatine kinase, the central regulatory enzyme of energy metabolism, facilitates the development of high blood pressure. Creatine kinase rapidly provides adenosine triphosphate to highly energy-demanding processes, including cardiovascular

Creatine protects against mitochondrial dysfunction associated with HIV-1 Tat-induced neuronal injury

Science.gov (United States)

Stevens, Patrick R.; Gawryluk, Jeremy W.; Hui, Liang; Chen, Xuesong; Geiger, Jonathan D.

2015-01-01

HIV-1 infected individuals are living longer but experiencing a prevalence rate of over 50% for HIV-1 associated neurocognitive disorders (HAND) for which no effective treatment is available. Viral and cellular factors secreted by HIV-1 infected cells leads to neuronal injury and HIV-1 Tat continues to be implicated in the pathogenesis of HAND. Here we tested the hypothesis that creatine protected against HIV-1 Tat-induced neuronal injury by preventing mitochondrial bioenergetic crisis and/or redox catastrophe. Creatine blocked HIV-1 Tat1-72-induced increases in neuron cell death and synaptic area loss. Creatine protected against HIV-1 Tat-induced decreases in ATP. Creatine and creatine plus HIV-1 Tat increased cellular levels of creatine, and creatine plus HIV-1 Tat further decreased ratios of phosphocreatine to creatine observed with creatine or HIV-1 Tat treatments alone. Additionally, creatine protected against HIV-1 Tat-induced mitochondrial hypopolarization and HIV-1 Tat-induced mitochondrial permeability transition pore opening. Thus, creatine may be a useful adjunctive therapy against HAND. PMID:25613139

Creatine in the central nervous system: From magnetic resonance spectroscopy to creatine deficiencies.

Science.gov (United States)

Rackayova, Veronika; Cudalbu, Cristina; Pouwels, Petra J W; Braissant, Olivier

2017-07-15

Creatine (Cr) is an important organic compound acting as intracellular high-energy phosphate shuttle and in energy storage. While located in most cells where it plays its main roles in energy metabolism and cytoprotection, Cr is highly concentrated in muscle and brain tissues, in which Cr also appears to act in osmoregulation and neurotransmission. This review discusses the basis of Cr metabolism, synthesis and transport within brain cells. The importance of Cr in brain function and the consequences of its impaired metabolism in primary and secondary Cr deficiencies are also discussed. Cr and phosphocreatine (PCr) in living systems can be well characterized using in vivo magnetic resonance spectroscopy (MRS). This review describes how 1 H MRS allows the measurement of Cr and PCr, and how 31 P MRS makes it possible to estimate the creatine kinase (CK) rate constant and so detect dynamic changes in the Cr/PCr/CK system. Absolute quantification by MRS using creatine as internal reference is also debated. The use of in vivo MRS to study brain Cr in a non-invasive way is presented, as well as its use in clinical and preclinical studies, including diagnosis and treatment follow-up in patients. Copyright © 2016 Elsevier Inc. All rights reserved.

On the importance of exchangeable NH protons in creatine for the magnetic coupling of creatine methyl protons in skeletal muscle

NARCIS (Netherlands)

Kruiskamp, M.J.; Nicolaij, K.

2001-01-01

The methyl protons of creatine in skeletal muscle exhibit a strong off-resonance magnetization transfer effect. The mechanism of this process is unknown. We previously hypothesized that the exchangeable amide/amino protons of creatine might be involved. To test this the characteristics of the

Computer simulation of plasma behavior in open-ended linear theta machines. Scientific report 81-5

International Nuclear Information System (INIS)

Stover, E.K.

1981-04-01

Zero-dimensional and one-dimensional fluid plasma computer models have been developed to study the behavior of linear theta pinch plasmas. Computer simulation results generated from these codes are compared with data obtained from two theta pinch experiments so that significant machine plasma behavior can be identified. The experiments examined are a collisional experiment, T/sub i/ approx. 50 eV, n/sub e/ approx. 10 17 cm -3 , where the plasma mean-free-path was significantly less than the plasma column length, and a hot ion species experiment, T/sub i/ approx. 3 keV, n/sub e/ approx. 10 16 cm -3 , where the ion mean-free-path was on the order of the plasma column length

Creatine affords protection against glutamate-induced nitrosative and oxidative stress.

Science.gov (United States)

Cunha, Mauricio P; Lieberknecht, Vicente; Ramos-Hryb, Ana Belén; Olescowicz, Gislaine; Ludka, Fabiana K; Tasca, Carla I; Gabilan, Nelson H; Rodrigues, Ana Lúcia S

2016-05-01

Creatine has been reported to exert beneficial effects in several neurodegenerative diseases in which glutamatergic excitotoxicity and oxidative stress play an etiological role. The purpose of this study was to investigate the protective effects of creatine, as compared to the N-Methyl-d-Aspartate (NMDA) receptor antagonist dizocilpine (MK-801), against glutamate or hydrogen peroxide (H2O2)-induced injury in human neuroblastoma SH-SY5Y cells. Exposure of cells to glutamate (60-80 mM) or H2O2 (200-300 μM) for 24 h decreased cellular viability and increased dichlorofluorescein (DCF) fluorescence (indicative of increased reactive oxygen species, ROS) and nitric oxide (NO) production (assessed by mono-nitrogen oxides, NOx, levels). Creatine (1-10 mM) or MK-801 (0.1-10 μM) reduced glutamate- and H2O2-induced toxicity. The protective effect of creatine against glutamate-induced toxicity involves its antioxidant effect, since creatine, similar to MK-801, prevented the increase on DCF fluorescence induced by glutamate or H2O2. Furthermore, creatine or MK-801 blocked glutamate- and H2O2-induced increases in NOx levels. In another set of experiments, the repeated, but not acute, administration of creatine (300 mg/kg, po) in mice prevented the decreases on cellular viability and mitochondrial membrane potential (assessed by tetramethylrhodamine ethyl ester, TMRE, probe) of hippocampal slices incubated with glutamate (10 mM). Creatine concentration-dependent decreased the amount of nitrite formed in the reaction of oxygen with NO produced from sodium nitroprusside solution, suggesting that its protective effect against glutamate or H2O2-induced toxicity might be due to its scavenger activity. Overall, the results suggest that creatine may be useful as adjuvant therapy for neurodegenerative disease treatments. Copyright © 2016 Elsevier Ltd. All rights reserved.

Creatine Supplementation Does Not Prevent the Development of Alcoholic Steatosis.

Science.gov (United States)

Ganesan, Murali; Feng, Dan; Barton, Ryan W; Thomes, Paul G; McVicker, Benita L; Tuma, Dean J; Osna, Natalia A; Kharbanda, Kusum K

2016-11-01

Alcohol-induced reduction in the hepatocellular S-adenosylmethionine (SAM):S-adenosylhomocysteine (SAH) ratio impairs the activities of many SAM-dependent methyltransferases. These impairments ultimately lead to the generation of several hallmark features of alcoholic liver injury including steatosis. Guanidinoacetate methyltransferase (GAMT) is an important enzyme that catalyzes the final reaction in the creatine biosynthetic process. The liver is a major site for creatine synthesis which places a substantial methylation burden on this organ as GAMT-mediated reactions consume as much as 40% of all the SAM-derived methyl groups. We hypothesized that dietary creatine supplementation could potentially spare SAM, preserve the hepatocellular SAM:SAH ratio, and thereby prevent the development of alcoholic steatosis and other consequences of impaired methylation reactions. For these studies, male Wistar rats were pair-fed the Lieber-DeCarli control or ethanol (EtOH) diet with or without 1% creatine supplementation. At the end of 4 to 5 weeks of feeding, relevant biochemical and histological analyses were performed. We observed that creatine supplementation neither prevented alcoholic steatosis nor attenuated the alcohol-induced impairments in proteasome activity. The lower hepatocellular SAM:SAH ratio seen in the EtOH-fed rats was also not normalized or SAM levels spared when these rats were fed the creatine-supplemented EtOH diet. However, a >10-fold increased level of creatine was observed in the liver, serum, and hearts of rats fed the creatine-supplemented diets. Overall, dietary creatine supplementation did not prevent alcoholic liver injury despite its known efficacy in preventing high-fat-diet-induced steatosis. Betaine, a promethylating agent that maintains the hepatocellular SAM:SAH, still remains our best option for treating alcoholic steatosis. Copyright © 2016 by the Research Society on Alcoholism.

Creatine Protects against Excitoxicity in an In Vitro Model of Neurodegeneration

Science.gov (United States)

Genius, Just; Geiger, Johanna; Bender, Andreas; Möller, Hans-Jürgen; Klopstock, Thomas; Rujescu, Dan

2012-01-01

Creatine has been shown to be neuroprotective in aging, neurodegenerative conditions and brain injury. As a common molecular background, oxidative stress and disturbed cellular energy homeostasis are key aspects in these conditions. Moreover, in a recent report we could demonstrate a life-enhancing and health-promoting potential of creatine in rodents, mainly due to its neuroprotective action. In order to investigate the underlying pharmacology mediating these mainly neuroprotective properties of creatine, cultured primary embryonal hippocampal and cortical cells were challenged with glutamate or H2O2. In good agreement with our in vivo data, creatine mediated a direct effect on the bioenergetic balance, leading to an enhanced cellular energy charge, thereby acting as a neuroprotectant. Moreover, creatine effectively antagonized the H2O2-induced ATP depletion and the excitotoxic response towards glutamate, while not directly acting as an antioxidant. Additionally, creatine mediated a direct inhibitory action on the NMDA receptor-mediated calcium response, which initiates the excitotoxic cascade. Even excessive concentrations of creatine had no neurotoxic effects, so that high-dose creatine supplementation as a health-promoting agent in specific pathological situations or as a primary prophylactic compound in risk populations seems feasible. In conclusion, we were able to demonstrate that the protective potential of creatine was primarily mediated by its impact on cellular energy metabolism and NMDA receptor function, along with reduced glutamate spillover, oxidative stress and subsequent excitotoxicity. PMID:22347384

Creatine Transporter Deficiency in Two Brothers with Autism Spectrum Disorder.

Science.gov (United States)

Aydin, Halil Ibrahim

2018-01-15

Creatine transporter deficiency (CTD) is a treatable, X-linked, inborn error of metabolism. Two brothers with autism spectrum disorder were diagnosed with CTD at the ages of 17 and 12 years. Both were found to have a previously reported hemizygous p.408delF (c.1216_1218delTTC) deletion mutation. Both patients were given creatine monohydrate, L-arginine, L-glycine and S-adenosylmethionine, which partially improved the behavioral problems. Serum creatinine levels, creatine peak at brain MR spectroscopy or creatine/creatinine ratio in urine should be evaluated to identify CTD in children with autistic behavior and language disorders.

Complete inhibition of creatine kinase in isolated perfused rat hearts

International Nuclear Information System (INIS)

Fossel, E.T.; Hoefeler, H.

1987-01-01

Transient exposure of an isolated isovolumic perfused rat heart to low concentrations (0.5 mM) of perfusate-born iodoacetamide resulted in complete inhibition of creatine kinase and partial inhibition of glyceraldehyde-3-phosphate dehydrogenase in the heart. At low levels of developed pressure, hearts maintained mechanical function, ATP, and creatine phosphate levels at control values. However, iodoacetamide-inhibited hearts were unable to maintain control values of end diastolic pressure or peak systolic pressure as work load increased. Global ischemia resulted in loss of all ATP without loss of creatine phosphate, indicating lack of active creatine kinase. These results indicate that isovolumic perfused rat hearts are able to maintain normal function and normal levels of high-energy phosphates without active creatine kinase at low levels of developed pressure. 31 P-NMR of the heart was carried out

Creatine kinase isozyme expression in embryonic chicken heart

NARCIS (Netherlands)

Lamers, W. H.; Geerts, W. J.; Moorman, A. F.; Dottin, R. P.

1989-01-01

The distribution pattern of creatine kinase (EC 2.7.3.2) isozymes in developing chicken heart was studied by immunohistochemistry. Creatine kinase M, which is absent from adult heart, is transiently expressed between 4 and 11 days of incubation. During that period, numerous muscular cells in the

Computer simulation of plasma behavior in open-ended linear theta machines. Scientific report 81-5

Energy Technology Data Exchange (ETDEWEB)

Stover, E. K.

1981-04-01

Zero-dimensional and one-dimensional fluid plasma computer models have been developed to study the behavior of linear theta pinch plasmas. Computer simulation results generated from these codes are compared with data obtained from two theta pinch experiments so that significant machine plasma behavior can be identified. The experiments examined are a collisional experiment, T/sub i/ approx. 50 eV, n/sub e/ approx. 10/sup 17/ cm/sup -3/, where the plasma mean-free-path was significantly less than the plasma column length, and a hot ion species experiment, T/sub i/ approx. 3 keV, n/sub e/ approx. 10/sup 16/ cm/sup -3/, where the ion mean-free-path was on the order of the plasma column length.

Creatine kinase BB and beta-2-microglobulin as markers of CNS metastases in patients with small-cell lung cancer

DEFF Research Database (Denmark)

Pedersen, A G; Bach, F W; Nissen, Mogens Holst

1985-01-01

Creatine kinase (CK) and its BB isoenzyme (CK-BB) were measured in CSF in 65 evaluable patients suspected of CNS metastases secondary to small-cell lung cancer (SCLC). In addition, CSF and plasma levels of beta-2-microglobulin (beta-2-m) were measured in a group of 73 evaluable patients. Of the 65...

Treatment of Creatine Transporter (SLC6A8) Deficiency With Oral S-Adenosyl Methionine as Adjunct to L-arginine, Glycine, and Creatine Supplements.

Science.gov (United States)

Jaggumantri, Sravan; Dunbar, Mary; Edgar, Vanessa; Mignone, Cristina; Newlove, Theresa; Elango, Rajavel; Collet, Jean Paul; Sargent, Michael; Stockler-Ipsiroglu, Sylvia; van Karnebeek, Clara D M

2015-10-01

Creatine transporter (SLC6A8) deficiency is an X-linked inborn error of metabolism characterized by cerebral creatine deficiency, behavioral problems, seizures, hypotonia, and intellectual developmental disability. A third of patients are amenable to treatment with high-dose oral creatine, glycine, and L-arginine supplementation. Given the limited treatment response, we initiated an open-label observational study to evaluate the effect of adjunct S-adenosyl methionine to further enhance intracerebral creatine synthesis. Significant and reproducible issues with sleep and behavior were noted in both male patients on a dose of 50/mg/kg. One of the two patients stopped S-adenosyl methionine and did not come for any follow-up. A safe and tolerable dose (17 mg/kg/day) was identified in the other patient. On magnetic resonance spectroscopy, this 8-year-old male did not show an increase in intracerebral creatine. However, significant improvement in speech/language skills, muscle mass were observed as well as in personal outcomes as defined by the family in activities related to communication and decision making. Further research is needed to assess the potential of S-adenosyl methionine as an adjunctive therapy for creatine transporter deficiency patients and to define the optimal dose. Our study also illustrates the importance of pathophysiology-based treatment, individualized outcome assessment, and patient/family participation in rare diseases research. Copyright © 2015 Elsevier Inc. All rights reserved.

Interactions of Aging, Overload, and Creatine Supplementation in Rat Plantaris Muscle

Directory of Open Access Journals (Sweden)

Mark D. Schuenke

2011-01-01

Full Text Available Attenuation of age-related sarcopenia by creatine supplementation has been equivocal. In this study, plantaris muscles of young (Y; 5m and aging (A; 24m Fisher 344 rats underwent four weeks of either control (C, creatine supplementation (Cr, surgical overload (O, or overload plus creatine (OCr. Creatine alone had no effect on muscle fiber cross-sectional area (CSA or heat shock protein (HSP70 and increased myonuclear domain (MND only in young rats. Overload increased CSA and HSP70 content in I and IIA fibers, regardless of age, and MND in IIA fibers of YO rats. CSA and MND increased in all fast fibers of YOCr, and CSA increased in I and IIA fibers of AOCr. OCR did not alter HSP70, regardless of age. MND did not change in aging rats, regardless of treatment. These data indicate creatine alone had no significant effect. Creatine with overload produced no additional hypertrophy relative to overload alone and attenuated overload-induced HSP70 expression.

A creatine-driven substrate cycle enhances energy expenditure and thermogenesis in beige fat.

Science.gov (United States)

Kazak, Lawrence; Chouchani, Edward T; Jedrychowski, Mark P; Erickson, Brian K; Shinoda, Kosaku; Cohen, Paul; Vetrivelan, Ramalingam; Lu, Gina Z; Laznik-Bogoslavski, Dina; Hasenfuss, Sebastian C; Kajimura, Shingo; Gygi, Steve P; Spiegelman, Bruce M

2015-10-22

Thermogenic brown and beige adipose tissues dissipate chemical energy as heat, and their thermogenic activities can combat obesity and diabetes. Herein the functional adaptations to cold of brown and beige adipose depots are examined using quantitative mitochondrial proteomics. We identify arginine/creatine metabolism as a beige adipose signature and demonstrate that creatine enhances respiration in beige-fat mitochondria when ADP is limiting. In murine beige fat, cold exposure stimulates mitochondrial creatine kinase activity and induces coordinated expression of genes associated with creatine metabolism. Pharmacological reduction of creatine levels decreases whole-body energy expenditure after administration of a β3-agonist and reduces beige and brown adipose metabolic rate. Genes of creatine metabolism are compensatorily induced when UCP1-dependent thermogenesis is ablated, and creatine reduction in Ucp1-deficient mice reduces core body temperature. These findings link a futile cycle of creatine metabolism to adipose tissue energy expenditure and thermal homeostasis. PAPERCLIP. Copyright © 2015 Elsevier Inc. All rights reserved.

A Creatine-Driven Substrate Cycle Enhances Energy Expenditure and Thermogenesis in Beige Fat

Science.gov (United States)

Kazak, Lawrence; Chouchani, Edward T.; Jedrychowski, Mark P.; Erickson, Brian K.; Shinoda, Kosaku; Cohen, Paul; Vetrivelan, Ramalingam; Lu, Gina Z.; Laznik-Bogoslavski, Dina; Hasenfuss, Sebastian C.; Kajimura, Shingo; Gygi, Steve P.; Spiegelman, Bruce M.

2015-01-01

SUMMARY Thermogenic brown and beige adipose tissues dissipate chemical energy as heat, and their thermogenic activities can combat obesity and diabetes. Herein the functional adaptations to cold of brown and beige adipose depots are examined using quantitative mitochondrial proteomics. We identify arginine/creatine metabolism as a beige adipose signature and demonstrate that creatine enhances respiration in beige fat mitochondria when ADP is limiting. In murine beige fat, cold exposure stimulates mitochondrial Creatine Kinase activity and induces coordinated expression of genes associated with creatine metabolism. Pharmacological reduction of creatine levels decreases whole body energy expenditure after administration of a β3-agonist and reduces the adipose metabolic rate. Genes of creatine metabolism are compensatorily induced when UCP1-dependent thermogenesis is ablated, and creatine reduction in Ucp1-deficient mice reduces core body temperature. These findings link a futile cycle of creatine metabolism to adipose tissue energy expenditure and thermal homeostasis. PMID:26496606

Cytogenetical Effect of Creatine Monohydrate in Vicia faba Root Tips

International Nuclear Information System (INIS)

Ali, A.A.M.; El-zahrani, N.H.; El-shamrani, S.M.

2010-01-01

The present study has been conducted to evaluate the creatine effect on the cellular behavior at mitosis of Vicia faba using four concentrations (1.50, 2, 2.50 and 3 g/ 100 ml) with three exposure times (6, 12, 24 hour). Marked reduction of mitotic index was recorded at all creatine treatments and this trait was affected by creatine concentration and exposure time. Unbalanced mitotic stages percentages were observed after all treatments whereas, prophase % was decreased in all treatments but the opposite was true for metaphase %. While, (ana-telo) phases % were either increased or decreased after creatine treatments. Alteration of DNA or RNA contents, were obtained at different treatments. On the other hand, abnormalities were shown at all treatments with an increase percentage by increasing creatine concentration and exposure time. The most common of these abnormalities were: stickiness, disturbed and C metaphase. In addition, laggards, multipolor, and bridges were observed in some treatments but with low percentage

Creatine Monohydrate Enhances Energy Status and Reduces Glycolysis via Inhibition of AMPK Pathway in Pectoralis Major Muscle of Transport-Stressed Broilers.

Science.gov (United States)

Zhang, Lin; Wang, Xiaofei; Li, Jiaolong; Zhu, Xudong; Gao, Feng; Zhou, Guanghong

2017-08-16

Creatine monohydrate (CMH) contributes to reduce transport-induced muscle rapid glycolysis and improve meat quality of broilers, but the underlying mechanism is still unknown. Therefore, this study aimed to investigate the molecular mechanisms underlying the ameliorative effects of CMH on muscle glycolysis metabolism of transported broilers during summer. The results showed that 3 h transport during summer elevated chicken live weight loss and plasma corticosterone concentration; decreased muscle concentrations of ATP, creatine, and energy charge value; increased muscle AMP concentration and AMP/ATP ratio; and upregulated muscle mRNA expression of LKB1 and AMPKα2, as well as protein expression of p-LKB1 Thr189 and p-AMPKα Thr172 , which subsequently resulted in rapid glycolysis in the pectoralis major muscle and consequent reduction of meat quality. Dietary addition of CMH at 1200 mg/kg ameliorated transport-induced rapid muscle glycolysis and reduction of meat quality via enhancement of the energy-buffering capacity of intramuscular phosphocreatine/creatine system and inhibition of AMPK pathway.

Guanidinoacetic acid loading affects plasma γ-aminobutyric acid in healthy men.

Science.gov (United States)

Ostojic, Sergej M; Stojanovic, Marko

2015-08-01

Guanidinoacetic acid (GAA), a precursor of creatine and an innovative dietary agent, activates γ-amino butyric acid (GABA) receptors yet clinical effects of dietary GAA on GABA metabolism are currently unknown. The main aim of this pilot research was to investigate whether GAA loading affected peripheral GABA homeostasis in healthy humans. Eight healthy male volunteers aged 22-25 years were randomized in a double-blind design to receive either GAA (three grams daily) or placebo by oral administration for 3 weeks. At baseline and after 3 weeks participants provided fasting blood samples for free plasma levels of GABA, GAA, creatine and glutamine. Following 3 weeks of intervention, plasma GABA level dropped significantly in participants receiving 3 g of GAA per day as compared to the placebo (P = 0.03). GAA loading significantly decreased plasma GABA by 88.8 nmol/L (95% confidence interval; 5.4-172.1) after 3 weeks of intervention as compared to the baseline (P = 0.03). GAA intervention positively affected both plasma GAA and creatine (P GABA metabolism, and potentially down-regulates GABA synthesis in peripheral tissues. Possible GABAergic action of dietary GAA adds to the safety profile of this novel dietary supplement.

Effect of age, diet, and tissue type on PCr response to creatine supplementation.

Science.gov (United States)

Solis, Marina Yazigi; Artioli, Guilherme Giannini; Otaduy, Maria Concepción García; Leite, Claudia da Costa; Arruda, Walquiria; Veiga, Raquel Ramos; Gualano, Bruno

2017-08-01

Creatine/phosphorylcreatine (PCr) responses to creatine supplementation may be modulated by age, diet, and tissue, but studies assessing this possibility are lacking. Therefore we aimed to determine whether PCr responses vary as a function of age, diet, and tissue. Fifteen children, 17 omnivorous and 14 vegetarian adults, and 18 elderly individuals ("elderly") participated in this study. Participants were given placebo and subsequently creatine (0.3 g·kg -1 ·day -1 ) for 7 days in a single-blind fashion. PCr was measured through phosphorus magnetic resonance spectroscopy ( 31 P-MRS) in muscle and brain. Creatine supplementation increased muscle PCr in children ( P creatine supplementation in any group, and delta changes in brain PCr (-0.7 to +3.9%) were inferior to those in muscle PCr content (+10.3 to +27.6%; P creatine protocol (0.3 g·kg -1 ·day -1 for 7 days) may be affected by age, diet, and tissue. Whereas creatine supplementation was able to increase muscle PCr in all groups, although to different extents, brain PCr was shown to be unresponsive overall. These findings demonstrate the need to tailor creatine protocols to optimize creatine/PCr accumulation both in muscle and in brain, enabling a better appreciation of the pleiotropic properties of creatine. NEW & NOTEWORTHY A standardized creatine supplementation protocol (0.3 g·kg -1 ·day -1 for 7 days) effectively increased muscle, but not brain, phosphorylcreatine. Older participants responded better than younger participants whereas vegetarians responded better than omnivores. Responses to supplementation are thus dependent on age, tissue, and diet. This suggests that a single "universal" protocol, originally designed for increasing muscle creatine in young individuals, may lead to heterogeneous muscle responses in different populations or even no responses in tissues other than skeletal muscle. Copyright © 2017 the American Physiological Society.

Exclusion of acute myocardial infarction. The value of measuring creatine kinase slope

NARCIS (Netherlands)

Bakker, A. J.; Koelemay, M. J.; van Vlies, B.; Gorgels, J. P.; Smits, R.; Tijssen, J. G.; Haagen, F. D.

1995-01-01

For the exclusion (and diagnosis) of acute myocardial infarction, we studied timed sequential (slope) measurements of creatine kinase and creatine kinase-MB catalytic activity concentration, creatine kinase-MB mass concentration, troponin T and myoglobin, using data from 242 patients consecutively

The cataract and glucosuria associated monocarboxylate transporter MCT12 is a new creatine transporter

Science.gov (United States)

Abplanalp, Jeannette; Laczko, Endre; Philp, Nancy J.; Neidhardt, John; Zuercher, Jurian; Braun, Philipp; Schorderet, Daniel F.; Munier, Francis L.; Verrey, François; Berger, Wolfgang; Camargo, Simone M.R.; Kloeckener-Gruissem, Barbara

2013-01-01

Creatine transport has been assigned to creatine transporter 1 (CRT1), encoded by mental retardation associated SLC6A8. Here, we identified a second creatine transporter (CRT2) known as monocarboxylate transporter 12 (MCT12), encoded by the cataract and glucosuria associated gene SLC16A12. A non-synonymous alteration in MCT12 (p.G407S) found in a patient with age-related cataract (ARC) leads to a significant reduction of creatine transport. Furthermore, Slc16a12 knockout (KO) rats have elevated creatine levels in urine. Transport activity and expression characteristics of the two creatine transporters are distinct. CRT2 (MCT12)-mediated uptake of creatine was not sensitive to sodium and chloride ions or creatine biosynthesis precursors, breakdown product creatinine or creatine phosphate. Increasing pH correlated with increased creatine uptake. Michaelis–Menten kinetics yielded a Vmax of 838.8 pmol/h/oocyte and a Km of 567.4 µm. Relative expression in various human tissues supports the distinct mutation-associated phenotypes of the two transporters. SLC6A8 was predominantly found in brain, heart and muscle, while SLC16A12 was more abundant in kidney and retina. In the lens, the two transcripts were found at comparable levels. We discuss the distinct, but possibly synergistic functions of the two creatine transporters. Our findings infer potential preventive power of creatine supplementation against the most prominent age-related vision impaired condition. PMID:23578822

Effects on Energy Metabolism of Two Guanidine Molecules, (Boc)2 -Creatine and Metformin.

Science.gov (United States)

Garbati, Patrizia; Ravera, Silvia; Scarfì, Sonia; Salis, Annalisa; Rosano, Camillo; Poggi, Alessandro; Damonte, Gianluca; Millo, Enrico; Balestrino, Maurizio

2017-09-01

Several enzymes are involved in the energy production, becoming a possible target for new anti-cancer drugs. In this paper, we used biochemical and in silico studies to evaluate the effects of two guanidine molecules, (Boc) 2 -creatine and metformin, on creatine kinase, an enzyme involved in the regulation of intracellular energy levels. Our results show that both drugs inhibit creatine kinase activity; however, (Boc) 2 -creatine displays a competitive inhibition, while metformin acts with a non-competitive mechanism. Moreover, (Boc) 2 -creatine is able to inhibit the activity of hexokinase with a non-competitive mechanism. Considering that creatine kinase and hexokinase are involved in energy metabolism, we evaluated the effects of (Boc) 2 -creatine and metformin on the ATP/AMP ratio and on cellular proliferation in healthy fibroblasts, human breast cancer cells (MDA-MB-468), a human neuroblastoma cell line (SH-SY5Y), a human Hodgkin lymphoma cell line (KMH2). We found that healthy fibroblasts were only partially affected by (Boc) 2 -creatine, while both ATP/AMP ratio and viability of the three cancer cell lines were significantly decreased. By inhibiting both creatine kinase and hexokinase, (Boc) 2 -creatine appears as a promising new agent in anticancer treatment. Further research is needed to understand what types of cancer cells are most suitable to treatment by this new compound. J. Cell. Biochem. 118: 2700-2711, 2017. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

Numerical experimentation on focusing time and neutron yield in GN1 plasma focus machine

International Nuclear Information System (INIS)

Singh, Arwinder; Lee, Sing; Saw, S.H.

2014-01-01

In this paper, we have shown how we have fitted Lee's six phase model code to analyze the current waveform of the GN1 plasma focus machine working in deuterium gas. The Lee's 6-phase model codes was later configured to work between 0.5 to 6 Torr and the results of both focusing time and neutron yield was then compared with the published experimental results. The final results indicate that Lee's code, gives realistic plasma dynamics and focus properties together with a realistic neutron yield for GN1 plasma focus, without the need of any adjustable parameters, needing only to fit the computed current trace to a measured current trace. (author)

Exploratory studies of the potential anti-cancer effects of creatine.

Science.gov (United States)

Campos-Ferraz, P L; Gualano, B; das Neves, W; Andrade, I T; Hangai, I; Pereira, R T S; Bezerra, R N; Deminice, R; Seelaender, M; Lancha, A H

2016-08-01

Two experiments were performed, in which male Wistar Walker 256 tumor-bearing rats were inoculated with 4 × 10(7) tumor cells subcutaneously and received either creatine (300 mg/kg body weight/day; CR) or placebo (water; PL) supplementation via intragastric gavage. In experiment 1, 50 rats were given PL (n = 22) or CR (n = 22) and a non-supplemented, non-inoculated group served as control CT (n = 6), for 40 days, and the survival rate and tumor mass were assessed. In experiment 2, 25 rats were given CR or PL for 15 days and sacrificed for biochemical analysis. Again, a non-supplemented, non-inoculated group served as control (CT; n = 6). Tumor and muscle creatine kinase (CK) activity and total creatine content, acidosis, inflammatory cytokines, and antioxidant capacity were assessed. Tumor growth was significantly reduced by approximately 30 % in CR when compared with PL (p = 0.03), although the survival rate was not significantly different between CR and PL (p = 0.65). Tumor creatine content tended to be higher in CR than PL (p = 0.096). Tumor CK activity in the cytosolic fraction was higher in CR than PL (p Creatine supplementation was able to slow tumor growth without affecting the overall survival rate, probably due to the re-establishment of the CK-creatine system in cancer cells, leading to attenuation in acidosis, inflammation, and oxidative stress. These findings support the role of creatine as a putative anti-cancer agent as well as help in expanding our knowledge on its potential mechanisms of action in malignancies.

Effect of creatine supplementation and drop-set resistance training in untrained aging adults.

Science.gov (United States)

Johannsmeyer, Sarah; Candow, Darren G; Brahms, C Markus; Michel, Deborah; Zello, Gordon A

2016-10-01

To investigate the effects of creatine supplementation and drop-set resistance training in untrained aging adults. Participants were randomized to one of two groups: Creatine (CR: n=14, 7 females, 7 males; 58.0±3.0yrs, 0.1g/kg/day of creatine+0.1g/kg/day of maltodextrin) or Placebo (PLA: n=17, 7 females, 10 males; age: 57.6±5.0yrs, 0.2g/kg/day of maltodextrin) during 12weeks of drop-set resistance training (3days/week; 2 sets of leg press, chest press, hack squat and lat pull-down exercises performed to muscle fatigue at 80% baseline 1-repetition maximum [1-RM] immediately followed by repetitions to muscle fatigue at 30% baseline 1-RM). Prior to and following training and supplementation, assessments were made for body composition, muscle strength, muscle endurance, tasks of functionality, muscle protein catabolism and diet. Drop-set resistance training improved muscle mass, muscle strength, muscle endurance and tasks of functionality (pcreatine to drop-set resistance training significantly increased body mass (p=0.002) and muscle mass (p=0.007) compared to placebo. Males on creatine increased muscle strength (lat pull-down only) to a greater extent than females on creatine (p=0.005). Creatine enabled males to resistance train at a greater capacity over time compared to males on placebo (p=0.049) and females on creatine (p=0.012). Males on creatine (p=0.019) and females on placebo (p=0.014) decreased 3-MH compared to females on creatine. The addition of creatine to drop-set resistance training augments the gains in muscle mass from resistance training alone. Creatine is more effective in untrained aging males compared to untrained aging females. Copyright © 2016 Elsevier Inc. All rights reserved.

New Developments in Creatine Supplementation Research: Mechanisms of Athletic Performance Enhancement

OpenAIRE

DerHovanessian, Ariss

2002-01-01

In the last decade creatine supplementation has become the most popular ergogenic aid among athletes, with particular performance enhancements found in high-power output, anaerobic exercises. Physiologically, creatine and phosphocreatine provide an energy reservoir in skeletal muscle. Recent studies have also shown that the ergogenic effects of creatine are caused by muscle protein metabolism (or reduced catabolism), satellite cell proliferation, protective oxidant scavenging, and membrane st...

The effects of creatine pyruvate and creatine citrate on performance during high intensity exercise

Directory of Open Access Journals (Sweden)

Purpura Martin

2008-02-01

Full Text Available Abstract Background A double-blind, placebo-controlled, randomized study was performed to evaluate the effect of oral creatine pyruvate (Cr-Pyr and creatine citrate (Cr-Cit supplementation on exercise performance in healthy young athletes. Methods Performance during intermittent handgrip exercise of maximal intensity was evaluated before (pretest and after (posttest 28 days of Cr-Pyr (5 g/d, n = 16, Cr-Cit (5 g/d, n = 16 or placebo (pla, 5 g/d, n = 17 intake. Subjects performed ten 15-sec exercise intervals, each followed by 45 sec rest periods. Results Cr-Pyr (p Conclusion It is concluded that four weeks of Cr-Pyr and Cr-Cit intake significantly improves performance during intermittent handgrip exercise of maximal intensity and that Cr-Pyr might benefit endurance, due to enhanced activity of the aerobic metabolism.

Co-administration of creatine and guanidinoacetic acid for augmented tissue bioenergetics: A novel approach?

Science.gov (United States)

Ostojic, Sergej M

2017-07-01

A confined absorption of exogenous creatine through creatine transporter (CRT1) seems to hamper its optimal uptake in bioenergetical deficits. Co-administration of guanidinoacetic acid (GAA) along with creatine could target other transport channels besides CRT1, and supremely improve cellular levels of creatine. This innovative approach might tackle tissues difficult to reach with conventional creatine interventions, providing a potentially more effective and safe mixture in clinical pharmacology and therapeutics. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

Creatine Use and Exercise Heat Tolerance in Dehydrated Men

OpenAIRE

Watson, Greig; Casa, Douglas J; Fiala, Kelly A; Hile, Amy; Roti, Melissa W; Healey, Julie C; Armstrong, Lawrence E; Maresh, Carl M

2006-01-01

Context: Creatine monohydrate (CrM) use is highly prevalent in team sports (eg, football, lacrosse, ice hockey) and by athletes at the high school, college, professional, and recreational levels. Concerns have been raised about whether creatine use is associated with increased cramping, muscle injury, heat intolerance, and risk of dehydration.

Upregulation of the Creatine Transporter Slc6A8 by Klotho

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Ahmad Almilaji

2014-11-01

Full Text Available Background/Aims: The transmembrane Klotho protein contributes to inhibition of 1,25(OH2D3 formation. The extracellular domain of Klotho protein could function as an enzyme with e.g. β-glucuronidase activity, be cleaved off and be released into blood and cerebrospinal fluid. Klotho regulates several cellular transporters. Klotho protein deficiency accelerates the appearance of age related disorders including neurodegeneration and muscle wasting and eventually leads to premature death. The main site of Klotho protein expression is the kidney. Klotho protein is also appreciably expressed in other tissues including chorioid plexus. The present study explored the effect of Klotho protein on the creatine transporter CreaT (Slc6A8, which participates in the maintenance of neuronal function and survival. Methods: To this end cRNA encoding Slc6A8 was injected into Xenopus oocytes with and without additional injection of cRNA encoding Klotho protein. Creatine transporter CreaT (Slc6A8 activity was estimated from creatine induced current determined by two-electrode voltage-clamp. Results: Coexpression of Klotho protein significantly increased creatine-induced current in Slc6A8 expressing Xenopus oocytes. Coexpression of Klotho protein delayed the decline of creatine induced current following inhibition of carrier insertion into the cell membrane by brefeldin A (5 µM. The increase of creatine induced current by coexpression of Klotho protein in Slc6A8 expressing Xenopus oocytes was reversed by β-glucuronidase inhibitor (DSAL. Similarly, treatment of Slc6A8 expressing Xenopus oocytes with recombinant human alpha Klotho protein significantly increased creatine induced current. Conclusion: Klotho protein up-regulates the activity of creatine transporter CreaT (Slc6A8 by stabilizing the carrier protein in the cell membrane, an effect requiring β-glucuronidase activity of Klotho protein.

URINARY CREATINE AT REST AND AFTER REPEATED SPRINTS IN ATHLETES: A PILOT STUDY

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Nasrallah, F.; Feki, M.; Chamari, K.; Omar, S.; Alouane-Trabelsi, L.; Ben Mansour, A.; Kaabachi, N.

2014-01-01

Creatine plays a key role in muscle function and its evaluation is important in athletes. In this study, urinary creatine concentration was measured in order to highlight its possible significance in monitoring sprinters. The study included 51 sprinters and 25 age- and sex-matched untrained subjects as a control group. Body composition was measured and dietary intake estimated. Urine samples were collected before and after standardized physical exercise. Creatine was assessed by gas chromatography mass spectrometry. Basal urinary creatine (UC) was significantly lower in sprinters than controls (34±30 vs. 74±3 µmol/mmol creatinine, p creatine significantly decreased in both athletes and controls. UC is low in sprinters at rest and further decreases after exercise, most likely due to a high uptake and use of creatine by muscles, as muscle mass and physical activity are supposed to be greater in athletes than untrained subjects. Further studies are needed to test the value of urinary creatine as a non-invasive marker of physical condition and as a parameter for managing Cr supplementation in athletes. PMID:24917689

Caffeine and Creatine Content of Dietary Supplements Consumed by Brazilian Soccer Players.

Science.gov (United States)

Inácio, Suelen Galante; de Oliveira, Gustavo Vieira; Alvares, Thiago Silveira

2016-08-01

Caffeine and creatine are ingredients in the most popular dietary supplements consumed by soccer players. However, some products may not contain the disclosed amounts of the ingredients listed on the label, compromising the safe usage and the effectiveness of these supplements. Therefore, the aim of this study was to evaluate the content of caffeine and creatine in dietary supplements consumed by Brazilian soccer players. The results obtained were compared with the caffeine content listed on the product label. Two batches of the supplement brands consumed by ≥ 50% of the players were considered for analysis. The quantification of caffeine and creatine in the supplements was determined by a high-performance liquid chromatography system with UV detector. Nine supplements of caffeine and 7 supplements of creatine met the inclusion criteria for analysis. Eight brands of caffeine and five brands of creatine showed significantly different values (p soccer players present inaccurate values listed on the label, although most presented no difference among batches. To ensure consumer safety and product efficacy, accurate information on caffeine and creatine content should be provided on all dietary supplement labels.

Meta-Analysis of Creatine for Neuroprotection Against Parkinson's Disease.

Science.gov (United States)

Attia; Ahmed, Hussien; Gadelkarim, Mohamed; Morsi, Mahmoud; Awad, Kamal; Elnenny, Mohamed; Ghanem, Esraa; El-Jaafary, Shaimaa; Negida, Ahmed

2017-01-01

Creatine is an antioxidant agent that showed neuroprotective effects in animal models of Parkinson's disease (PD). Creatine was selected by the National Institute of Neurological Disorders and Stroke as a possible disease modifying agent for Parkinson's disease. Therefore, many clinical trials evaluated the efficacy of creatine for patients with PD. The aim of this systematic review and meta-analysis is to synthesize evidence from published randomized controlled trials (RCTs) about the efficacy of Creatine for patients with PD. We followed PRISMA statement guidelines during the preparation of this systematic review and meta-analysis. A computer literature search for PubMed, EBSCO, web of science and Ovid Midline was carried out. We included RCTs comparing creatine with placebo in terms of motor functions and quality of life. Outcomes of total Unified Parkinson's Disease Rating Scale (UPDRS), UPDRS I, UPDRS II, and UPDRS III were pooled as mean difference (MD) between two groups from baseline to the endpoint. Statistical heterogeneity was assessed by visual inspection of the forest plot and measured by chi-square and I square tests. Three RCTs (n=1935) were included in this study. The overall effect did not favor either of the two groups in terms of: UPDRS total score (MD 1.07, 95% CI [3.38 to 1.25], UPDRS III (MD 0.62, 95% CI [2.27 to 1.02]), UPDRS II (MD 0.03, 95% CI [0.81 to 0.86], or UPDRS I (MD 0.03, 95% CI [0.33 to 0.28]). Current evidence does not support the use of creatine for neuroprotection against PD. Future well-designed, randomized controlled trials are needed. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

Immunological measurements on the disappearance of creatine kinase MM from the circulation

International Nuclear Information System (INIS)

Wevers, R.A.; Landeghem, A.A.J. van; Mul-Steinbusch, M.W.F.J.; Bijdendijk, J.G.; Weerts, P.; Kloeg, P.; Soons, J.B.J.

1983-01-01

Both a two-site immunoradiometric assay and a two-site enzyme-linked immunosorbent assay for creatine kinase MM are described. Linearity, reproducibility and cross-reactivity of the assays are satisfactory. Creatine kinase MM incubated in a pH-controlled serum matrix loses its activity, but has its antigenic determinants affected as well. Of all the techniques used, only the immunoradiometric assay is capable of measuring part of the inactivated enzyme. Measurements with this assay on the sera of patients after a myocardial infarction show identical results for enzyme activity and creatine kinase protein quantity. The in vitro disappearance rate of creatine kinase activity is slow compared with the in vivo half-life of the enzyme. These two observations lead to the conclusion that creatine kinase is removed from the circulation long before it is inactivated in the blood stream. (Auth.)

Dietary guanidinoacetic acid increases brain creatine levels in healthy men

DEFF Research Database (Denmark)

Ostojic, Sergej M; Ostojic, Jelena; Drid, Patrik

2017-01-01

OBJECTIVE: Guanidinoacetic acid (GAA) is an experimental dietary additive that might act as a creatine source in tissues with high-energy requirements. In this case study, we evaluated brain levels of creatine in white matter, gray matter, cerebellum, and thalamus during 8 wk oral GAA......, and 8 wk, the participants underwent brain magnetic resonance spectroscopy, clinical chemistry studies, and open-ended questionnaire for side-effect prevalence and severity. RESULTS: Brain creatine levels increased in similar fashion in cerebellum, and white and gray matter after GAA supplementation......, with an initial increase of 10.7% reported after 4 wk, and additional upsurge (7.7%) from the weeks 4 to 8 follow-up (P creatine levels decreased after 4 wk for 6.5% (P = 0.02), and increased nonsignificantly after 8 wk for 8% (P = 0.09). GAA induced an increase in N-acetylaspartate levels at 8...

Caffeine, creatine, GRIN2A and Parkinson's disease progression.

Science.gov (United States)

Simon, David K; Wu, Cai; Tilley, Barbara C; Lohmann, Katja; Klein, Christine; Payami, Haydeh; Wills, Anne-Marie; Aminoff, Michael J; Bainbridge, Jacquelyn; Dewey, Richard; Hauser, Robert A; Schaake, Susen; Schneider, Jay S; Sharma, Saloni; Singer, Carlos; Tanner, Caroline M; Truong, Daniel; Wei, Peng; Wong, Pei Shieen; Yang, Tianzhong

2017-04-15

Caffeine is neuroprotective in animal models of Parkinson's disease (PD) and caffeine intake is inversely associated with the risk of PD. This association may be influenced by the genotype of GRIN2A, which encodes an NMDA-glutamate-receptor subunit. In two placebo-controlled studies, we detected no association of caffeine intake with the rate of clinical progression of PD, except among subjects taking creatine, for whom higher caffeine intake was associated with more rapid progression. We now have analyzed data from 420 subjects for whom DNA samples and caffeine intake data were available from a placebo-controlled study of creatine in PD. The GRIN2A genotype was not associated with the rate of clinical progression of PD in the placebo group. However, there was a 4-way interaction between GRIN2A genotype, caffeine, creatine and the time since baseline. Among subjects in the creatine group with high levels of caffeine intake, but not among those with low caffeine intake, the GRIN2A T allele was associated with more rapid progression (p=0.03). These data indicate that the deleterious interaction between caffeine and creatine with respect to rate of progression of PD is influenced by GRIN2A genotype. This example of a genetic factor interacting with environmental factors illustrates the complexity of gene-environment interactions in the progression of PD. Copyright © 2017 Elsevier B.V. All rights reserved.

Interleukin-6, Creatine Kinase, and Antioxidant Enzyme Activities following Platelet-Rich Plasma Treatment on Muscle Injury: A Pilot Study

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Lingling Lai

2016-06-01

Full Text Available The aim of this study was to investigate the effect of autologous platelet-rich plasma (PRP treatment alongside rehabilitation compared with rehabilitation alone on inflammatory cytokine (interleukin-6, IL-6, creatine kinase muscle type (CKM, and antioxidant enzymes (superoxide dismutase, SOD; catalase, CAT following hamstring injury. This study was a randomised control trial. Participants diagnosed with grade-2 acute hamstring injury (n=16 were divided into 2 groups of PRP treatment with rehabilitation program (PRP-T and rehabilitation program (CON. Blood samples were collected at baseline, and 2 fortnightly for the various biochemical assessments. Participants were certified to have recovered upon fulfilling return to play (RTP criteria. Level of IL-6 and the activities of CKM, SOD, and CAT were measured. PRP-T group benefited from earlier time to RTP with significantly lower IL-6 level and CAT activity compared to CON group. There was no significant difference in CKM and SOD activities between the groups, though a trend of lower values in all variables was observed at week 4 compared to week 0. PRP treatment potentially improves muscle healing process by altering both the inflammatory and oxidative responses, hence hastens time to RTP. KEY WORDS:  Autologous, blood injection, rehabilitation, sports injury, hamstring injury

Creatine supplementation: effects on blood creatine kinase activity responses to resistance exercise and creatine kinase activity measurement

Directory of Open Access Journals (Sweden)

Marco Machado

2009-12-01

Full Text Available The purpose of this study was to determine the effects of creatine supplementation and exercise on the integrity of muscle fiber, as well as the effect of the supplementation on the creatine kinase (CK assay measurement. Forty-nine sedentary individuals participated in a double-blind study and were divided into two groups: C (n=26 received 4x5-day packages of 0.6 g.kg-1 of body weight contained 50% of creatine + 50% of dextrose, and P (n=23 received packages containing only dextrose. On the first day the groups performed a 1RM test for bench press, seated row, leg extension, leg curl and leg press. On D7 they received the supplements. On the fourteenth day, they performed a training session of five exercises, each in three sets of ten repetitions at 75% of 1RM. Blood was collected before (D14 and after the exercise session (D15. Differing levels of blood creatine were tested to determine the influence on the assay measurements of CK. ANOVA and Tukey's post-hoc tests were used to compare groups and different times of study protocol (PO objetivo do presente estudo foi determinar o efeito da suplementação de creatina e do exercício na integridade das fibras musculares e, também, o efeito da suplementação na técnica de mensuração da atividade da creatina kinase (CK. Quarenta e nove sedentários participaram de um estudo duplo-cego e foram divididos em dois grupos: C (n=26 que receberam 4x5 dias embalagens com 0,6 g.kg-1 de massa corporal com 50% de creatina + 50% de dextrose, e P (n=23 que receberam embalagens contendo apenas dextrose. No primeiro dia, eles realizaram o teste de 1RM para os exercícios supino reto, remada sentada, cadeira extensora, mesa flexora, e leg press. No D7 receberam os suplementos. No décimo quarto dia eles realizaram uma sessão de treinos com os cinco exercícios, cada um com 3x10 repetições a 75% de 1RM. Sangue foi coletado antes (D14 e depois da sessão de exercícios (D15. Diferentes concentrações de

Maternal creatine supplementation affects the morpho-functional development of hippocampal neurons in rat offspring.

Science.gov (United States)

Sartini, S; Lattanzi, D; Ambrogini, P; Di Palma, M; Galati, C; Savelli, D; Polidori, E; Calcabrini, C; Rocchi, M B L; Sestili, P; Cuppini, R

2016-01-15

Creatine supplementation has been shown to protect neurons from oxidative damage due to its antioxidant and ergogenic functions. These features have led to the hypothesis of creatine supplementation use during pregnancy as prophylactic treatment to prevent CNS damage, such as hypoxic-ischemic encephalopathy. Unfortunately, very little is known on the effects of creatine supplementation during neuron differentiation, while in vitro studies revealed an influence on neuron excitability, leaving the possibility of creatine supplementation during the CNS development an open question. Using a multiple approach, we studied the hippocampal neuron morphological and functional development in neonatal rats born by dams supplemented with 1% creatine in drinking water during pregnancy. CA1 pyramidal neurons of supplemented newborn rats showed enhanced dendritic tree development, increased LTP maintenance, larger evoked-synaptic responses, and higher intrinsic excitability in comparison to controls. Moreover, a faster repolarizing phase of action potential with the appearance of a hyperpolarization were recorded in neurons of the creatine-treated group. Consistently, CA1 neurons of creatine exposed pups exhibited a higher maximum firing frequency than controls. In summary, we found that creatine supplementation during pregnancy positively affects morphological and electrophysiological development of CA1 neurons in offspring rats, increasing neuronal excitability. Altogether, these findings emphasize the need to evaluate the benefits and the safety of maternal intake of creatine in humans. Copyright © 2015 IBRO. Published by Elsevier Ltd. All rights reserved.

Urinary excretion of creatine and creatinine in gamma irradiated rats

Energy Technology Data Exchange (ETDEWEB)

Basu, S K; Srinivasan, M N; Chuttani, K; Bhatnagar, A; Ghose, A

1985-06-01

Dose response relationships of creatine, creatinine excretions and their ratio in 24 hr urine samples have been studied on each individual day upto 4 days after 1-7 Gy whole body gamma irradiation to rats. Creatine excretion reaches the peak on the 2nd day while creatinine excretion reaches the peak on the first day and a plateau is maintained up to the 4th day in each case. Good dose response correlationship is maintained for creatine or creatinine levels up to the 4th day and for creatine creatinine ratio up to the 3rd day. Seperate dose response curves are needed on each individual day for using these parameters for biological dosimetry purpose. Administration of the radioprotectors viz., combination of 5-hydroxytryptophan (HT) and 2-amino-ethylisothiuronium bromide hydrobromide (AET), HT alone and optimum radioprotecting dose of AET before 5 Gy whole body ..gamma..-irradiation have not been of help for reducing creatinineurea. (author).

Urinary excretion of creatine and creatinine in gamma irradiated rats

International Nuclear Information System (INIS)

Basu, S.K.; Srinivasan, M.N.; Chuttani, K.; Bhatnagar, A.; Ghose, A.

1985-01-01

Dose response relationships of creatine, creatinie excretions and their ratio in 24 hr urine samples have been studied on each individual day upto 4 days after 1-7 Gy whole body gamma irradiation to rats. Creatine excretion reaches the peak on the 2nd day while creatinine excretion reaches the peak on the first day and a plateau is maintained upto the 4th day in each case. Good dose response correlationship is maintained for creatine or creatinine levels upto the 4th day and for creatine creatinine ratio upto the 3rd day. Seperate dose response curves are needed on each individual day for using these parameters for biological dosimetry purpose. Administration of the radioprotectors viz., combination of 5-hydroxytryptophan (HT) and 2-amino-ethylisothiuronium bromide hydrobromide (AET), HT alone and optimum radioprotecting dose of AET before 5 Gy whole body γ-irradiation have not been of help for reducing creatinineurea. (author)

Rhabdomyolysis and acute kidney injury: creatine kinase as a prognostic marker and validation of the McMahon Score in a 10-year cohort: A retrospective observational evaluation.

Science.gov (United States)

Simpson, Joanna P; Taylor, Andrew; Sudhan, Nazneen; Menon, David K; Lavinio, Andrea

2016-12-01

High-volume fluid resuscitation and the administration of sodium bicarbonate and diuretics have a theoretical renoprotective role in patients at high risk of acute kidney injury (AKI) following rhabdomyolysis. Abnormally elevated creatine kinase has previously been used as a biological marker for the identification of patients at high risk of AKI following rhabdomyolysis. To assess the sensitivity and specificity of plasma creatine kinase (admission and peak values) for the prediction of AKI requiring renal replacement therapy (RRT) or of death in patients with confirmed rhabdomyolysis. To compare the diagnostic performance of creatine kinase with the McMahon score. Retrospective observational study. Data collection included McMahon and Acute Physiology and Chronic Health Evaluation II (APACHE II) scores; daily creatine kinase; daily creatinine and electrolytes; ICU length of stay and mortality. Neurosciences and Trauma Critical Care Unit (Cambridge, UK). In total, 232 adults with confirmed rhabdomyolysis (creatine kinase > 1000 Ul) admitted to Neurosciences and Trauma Critical Care Unit between 2002 and 2012. AKI, RRT and mortality. Forty-five (19%) patients developed AKI and 29 (12.5%) patients required RRT. Mortality was significantly higher in patients who developed AKI (62 vs. 18%, P rhabdomyolysis. Although a PEAK creatine kinase of at least 5000 Ul has sensitivity acceptable for screening purposes, this is often a delayed finding. A McMahon score of at least 6 calculated on admission allows for a more sensitive, specific and timely identification of patients who may benefit from high-volume fluid resuscitation.

Creatine maintains intestinal homeostasis and protects against colitis.

Science.gov (United States)

Turer, Emre; McAlpine, William; Wang, Kuan-Wen; Lu, Tianshi; Li, Xiaohong; Tang, Miao; Zhan, Xiaoming; Wang, Tao; Zhan, Xiaowei; Bu, Chun-Hui; Murray, Anne R; Beutler, Bruce

2017-02-14

Creatine, a nitrogenous organic acid, replenishes cytoplasmic ATP at the expense of mitochondrial ATP via the phosphocreatine shuttle. Creatine levels are maintained by diet and endogenous synthesis from arginine and glycine. Glycine amidinotransferase (GATM) catalyzes the rate-limiting step of creatine biosynthesis: the transfer of an amidino group from arginine to glycine to form ornithine and guanidinoacetate. We screened 36,530 third-generation germline mutant mice derived from N -ethyl- N -nitrosourea-mutagenized grandsires for intestinal homeostasis abnormalities after oral administration of dextran sodium sulfate (DSS). Among 27 colitis susceptibility phenotypes identified and mapped, one was strongly correlated with a missense mutation in Gatm in a recessive model of inheritance, and causation was confirmed by CRISPR/Cas9 gene targeting. Supplementation of homozygous Gatm mutants with exogenous creatine ameliorated the colitis phenotype. CRISPR/Cas9-targeted ( Gatm c/c ) mice displayed a normal peripheral immune response and immune cell homeostasis. However, the intestinal epithelium of the Gatm c/c mice displayed increased cell death and decreased proliferation during DSS treatment. In addition, Gatm c/c colonocytes showed increased metabolic stress in response to DSS with higher levels of phospho-AMPK and lower levels of phosphorylation of mammalian target of rapamycin (phospho-mTOR). These findings establish an in vivo requirement for rapid replenishment of cytoplasmic ATP within colonic epithelial cells in the maintenance of the mucosal barrier after injury.

Creatine supplementation in the aging population: effects on skeletal muscle, bone and brain.

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Gualano, Bruno; Rawson, Eric S; Candow, Darren G; Chilibeck, Philip D

2016-08-01

This narrative review aims to summarize the recent findings on the adjuvant application of creatine supplementation in the management of age-related deficits in skeletal muscle, bone and brain metabolism in older individuals. Most studies suggest that creatine supplementation can improve lean mass and muscle function in older populations. Importantly, creatine in conjunction with resistance training can result in greater adaptations in skeletal muscle than training alone. The beneficial effect of creatine upon lean mass and muscle function appears to be applicable to older individuals regardless of sex, fitness or health status, although studies with very old (>90 years old) and severely frail individuals remain scarce. Furthermore, there is evidence that creatine may affect the bone remodeling process; however, the effects of creatine on bone accretion are inconsistent. Additional human clinical trials are needed using larger sample sizes, longer durations of resistance training (>52 weeks), and further evaluation of bone mineral, bone geometry and microarchitecture properties. Finally, a number of studies suggest that creatine supplementation improves cognitive processing under resting and various stressed conditions. However, few data are available on older adults, and the findings are discordant. Future studies should focus on older adults and possibly frail elders or those who have already experienced an age-associated cognitive decline.

Structural Changes of Creatine Kinase upon Substrate Binding

OpenAIRE

Forstner, Michael; Kriechbaum, Manfred; Laggner, Peter; Wallimann, Theo

1998-01-01

Small-angle x-ray scattering was used to investigate structural changes upon binding of individual substrates or a transition state analog complex (TSAC; Mg-ADP, creatine, and KNO3) to creatine kinase (CK) isoenzymes (dimeric muscle-type (M)-CK and octameric mitochondrial (Mi)-CK) and monomeric arginine kinase (AK). Considerable changes in the shape and the size of the molecules occurred upon binding of Mg-nucleotide or TSAC. The radius of gyration of Mi-CK was reduced from 55.6 A (free enzym...

Early detection of response in small cell bronchogenic carcinoma by changes in serum concentrations of creatine kinase, neuron specific enolase, calcitonin, ACTH, serotonin and gastrin releasing peptide

DEFF Research Database (Denmark)

Bork, E; Hansen, M; Urdal, P

1988-01-01

Creatine kinase (CK-BB), neuron specific enolase (NSE), ACTH, calcitonin, serotonin and gastrin releasing peptide (GRP) were measured in serum or plasma before and immediately after initiation of treatment in patients with small cell lung cancer (SCC). Pretherapeutic elevated concentrations of CK...

Sex-specific antidepressant effects of dietary creatine with and without sub-acute fluoxetine in rats

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Allen, Patricia J.; D'Anci, Kristen E.; Kanarek, Robin B.; Renshaw, Perry F.

2013-01-01

The potential role of metabolic impairments in the pathophysiology of depression is motivating researchers to evaluate the treatment efficacy of creatine, a naturally occurring energetic and neuroprotective compound found in brain and muscle tissues. Growing evidence is demonstrating the benefit of oral creatine supplements for reducing depressive symptoms in humans and animals. A novel question is whether dietary creatine, when combined with antidepressant drug therapy, would be more effective than either compound alone. To answer this question, four studies were conducted to investigate the behavioral effects of combined creatine and low-dose fluoxetine treatment using the forced swim test in male and female rats. Sprague-Dawley rats were fed powdered rodent chow supplemented with 0%, 2% or 4% w/w creatine monohydrate for 5 weeks. Rats were injected with fluoxetine (5.0 or 10.0 mg/kg) or saline according to a sub-acute dosing schedule. Female rats maintained on a 4% creatine diet displayed antidepressant-like effects compared to non-supplemented females prior to fluoxetine treatment. In contrast, creatine did not alter behavior reliably in males. Following drug treatment and a second forced swim trial, the antidepressant-like profile of creatine remained significant only in females co-administered 5.0 mg/kg fluoxetine. Moreover, in females only, supplementation with 4% creatine produced a more robust antidepressant-like behavioral profile compared to either dose of fluoxetine alone. Estrous cycle data indicated that ovarian hormones influenced the antidepressant-like effects of creatine. Addressing the issue of sex differences in response to treatment may affect our understanding of creatine, its relationship with depressive behavior, and may lead to sex-specific therapeutic strategies. PMID:22429992

Creatine supplementation with methylglyoxal: a potent therapy for cancer in experimental models.

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Pal, Aparajita; Roy, Anirban; Ray, Manju

2016-08-01

The anti-cancer effect of methylglyoxal (MG) is now well established in the literature. The main aim of this study was to investigate the effect of creatine as a supplement in combination with MG both in vitro and in vivo. In case of the in vitro studies, two different cell lines, namely MCF-7 (human breast cancer cell line) and C2C12 (mouse myoblast cell line) were chosen. MG in combination with creatine showed enhanced apoptosis as well as higher cytotoxicity in the breast cancer MCF-7 cell line, compared to MG alone. Pre-treatment of well-differentiated C2C12 myotubes with cancerogenic 3-methylcholanthrene (3MC) induced a dedifferentiation of these myotubes towards cancerous cells (that mimic the effect of 3MC observed in solid fibro-sarcoma animal models) and subsequent exposure of these induced cancer cells with MG proved to be cytotoxic. Thus, creatine plus ascorbic acid enhanced the anti-cancer effects of MG. In contrast, when normal C2C12 muscle cells or myotubes (mouse normal myoblast cell line) were treated with MG or MG plus creatine and ascorbic acid, no detrimental effects were seen. This indicated that cytotoxic effects of MG are specifically limited towards cancer cells and are further enhanced when MG is used in combination with creatine and ascorbic acid. For the in vivo studies, tumors were induced by injecting Sarcoma-180 cells (2 × 10(6) cells/mouse) in the left hind leg. After 7 days of tumor inoculation, treatments were started with MG (20 mg/kg body wt/day, via the intravenous route), with or without creatine (150 mg/kg body wt/day, fed orally) and ascorbic acid (50 mg/kg body wt/day, fed orally) and continued for 10 consecutive days. Significant regression of tumor size was observed when Sarcoma-180 tumor-bearing mice were treated with MG and even more so with the aforesaid combination. The creatine-supplemented group demonstrated better overall survival in comparison with tumor-bearing mice without creatine. In conclusion, it may be

Purification and characterization of creatine kinase isozymes from the nurse shark Ginglymostoma cirratum.

Science.gov (United States)

Gray, K A; Grossman, S H; Summers, D D

1986-01-01

Creatine kinase from nurse shark brain and muscle has been purified to apparent homogeneity. In contrast to creatine kinases from most other vertebrate species, the muscle isozyme and the brain isozyme from nurse shark migrate closely in electrophoresis and, unusually, the muscle isozyme is anodal to the brain isozyme. The isoelectric points are 5.3 and 6.2 for the muscle and brain isozymes, respectively. The purified brain preparation also contains a second active protein with pI 6.0. The amino acid content of the muscle isozyme is compared with other isozymes of creatine kinase using the Metzger Difference Index as an estimation of compositional relatedness. All comparisons show a high degree of compositional similarity including arginine kinase from lobster muscle. The muscle isozyme is marginally more resistant to temperature inactivation than the brain isozyme; the muscle protein does not exhibit unusual stability towards high concentrations of urea. Kinetic analysis of the muscle isozyme reveals Michaelis constants of 1.6 mM MgATP, 12 mM creatine, 1.2 mM MgADP and 50 mM creatine phosphate. Dissociation constants for the same substrate from the binary and ternary enzyme-substrate complex do not differ significantly, indicating limited cooperatively in substrate binding. Enzyme activity is inhibited by small planar anions, most severely by nitrate. Shark muscle creatine kinase hybridizes in vitro with rabbit muscle or monkey brain creatine kinase; shark brain isozyme hybridizes with monkey brain or rabbit brain creatine kinase. Shark muscle and shark brain isozymes, under a wide range of conditions, failed to produce a detectable hybrid.

URINARY CREATINE AT REST AND AFTER REPEATED SPRINTS IN ATHLETES: A PILOT STUDY

Directory of Open Access Journals (Sweden)

I. Bezrati-Benayed

2014-07-01

Full Text Available Creatine plays a key role in muscle function and its evaluation is important in athletes. In this study, urinary creatine concentration was measured in order to highlight its possible significance in monitoring sprinters. The study included 51 sprinters and 25 age- and sex-matched untrained subjects as a control group. Body composition was measured and dietary intake estimated. Urine samples were collected before and after standardized physical exercise. Creatine was assessed by gas chromatography mass spectrometry. Basal urinary creatine (UC was significantly lower in sprinters than controls (34±30 vs. 74±3 μmol/mmol creatinine, p<0.05. UC was inversely correlated with body mass (r=-0.34, p<0.01 and lean mass (r=- 0.30, p<0.05, and positively correlated with fat mass (r=0.32, p<0.05. After acute exercise, urinary creatine significantly decreased in both athletes and controls. UC is low in sprinters at rest and further decreases after exercise, most likely due to a high uptake and use of creatine by muscles, as muscle mass and physical activity are supposed to be greater in athletes than untrained subjects. Further studies are needed to test the value of urinary creatine as a non-invasive marker of physical condition and as a parameter for managing Cr supplementation in athletes.

Influence of Arm-cranking on Changes in Plasma CK Activity after High Force Eccentric Exercise of the Elbow Flexors

OpenAIRE

Kazunori, NOSAKA; Kei, SAKAMOTO; Mike, NEWTON; Exercise and Sports Science, Graduate School of Integrated Science, Yokohama City University:School of Biomedical and Sports Science, Edith Cowan University; Exercise and Sports Science, Graduate School of Integrated Science, Yokohama City University; School of Biomedical and Sports Science, Edith Cowan University

2002-01-01

It was hypothesized that the time course of changes in plasma creatine kinase (CK) activity following eccentric exercise was influenced by rhythmical muscle contractions performed after eccentric exercise. This study examined whether arm-cranking (AC) alters the time course of changes in plasma creatine kinase (CK) activity after eccentric exercise of the elbow flexors (ECC). Six male students performed two bouts of ECC separated by 3 weeks, and AC (25watts, 2-hours) was performed immediately...

Myocardial Creatine Levels Do Not Influence Response to Acute Oxidative Stress in Isolated Perfused Heart

Science.gov (United States)

Aksentijević, Dunja; Zervou, Sevasti; Faller, Kiterie M. E.; McAndrew, Debra J.; Schneider, Jurgen E.; Neubauer, Stefan; Lygate, Craig A.

2014-01-01

Background Multiple studies suggest creatine mediates anti-oxidant activity in addition to its established role in cellular energy metabolism. The functional significance for the heart has yet to be established, but antioxidant activity could contribute to the cardioprotective effect of creatine in ischaemia/reperfusion injury. Objectives To determine whether intracellular creatine levels influence responses to acute reactive oxygen species (ROS) exposure in the intact beating heart. We hypothesised that mice with elevated creatine due to over-expression of the creatine transporter (CrT-OE) would be relatively protected, while mice with creatine-deficiency (GAMT KO) would fare worse. Methods and Results CrT-OE mice were pre-selected for creatine levels 20–100% above wild-type using in vivo 1H–MRS. Hearts were perfused in isovolumic Langendorff mode and cardiac function monitored throughout. After 20 min equilibration, hearts were perfused with either H2O2 0.5 µM (30 min), or the anti-neoplastic drug doxorubicin 15 µM (100 min). Protein carbonylation, creatine kinase isoenzyme activities and phospho-PKCδ expression were quantified in perfused hearts as markers of oxidative damage and apoptotic signalling. Wild-type hearts responded to ROS challenge with a profound decline in contractile function that was ameliorated by co-administration of catalase or dexrazoxane as positive controls. In contrast, the functional deterioration in CrT-OE and GAMT KO hearts was indistinguishable from wild-type controls, as was the extent of oxidative damage and apoptosis. Exogenous creatine supplementation also failed to protect hearts from doxorubicin-induced dysfunction. Conclusions Intracellular creatine levels do not influence the response to acute ROS challenge in the intact beating heart, arguing against creatine exerting (patho-)physiologically relevant anti-oxidant activity. PMID:25272153

Low dose creatine supplementation enhances sprint phase of 400 meters swimming performance.

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Anomasiri, Wilai; Sanguanrungsirikul, Sompol; Saichandee, Pisut

2004-09-01

This study demonstrated the effect of low dose creatine supplement (10 g. per day) on the sprinting time in the last 50 meters of 400 meters swimming competition, as well as the effect on exertion. Nineteen swimmers in the experimental group received creatine monohydrate 5 g with orange solution 15 g, twice per day for 7 days and nineteen swimmers in the control group received the same quantity of orange solution. The results showed that the swimmers who received creatine supplement lessened the sprinting time in the last 50 meters of 400 meters swimming competition than the control group. (p<0.05). The results of Wingate test (anaerobic power, anaerobic capacity and fatigue index) compared between pre and post supplementation. There was significant difference at p<0.05 in the control group from training effect whereas there was significant difference at p<0.000 from training effect and creatine supplement in the experiment group. Therefore, the creatine supplement in amateur swimmers in the present study enhanced the physical performance up to the maximum capacity.

Manufacturing technology development of plasma/ion nitriding for improvement of hardness of machine components and tools

International Nuclear Information System (INIS)

Suprapto; Tjipto Sujitno; Saminto

2015-01-01

The manufacturing technology development of plasma/ion nitriding to improve of hardness of machine components and tools has been done. The development of this technology aims to improve device performance plasma nitriding double chamber and conducted with the addition of thermal radiation shield. Testing was done by testing for preheating operation (start-up), test operation for conditions nitriding and test for nitriding process. The results show that: the plasma nitriding device can be operated for nitriding process at the temperature of about 500 °C for 6 hours, using the thermal radiation shield obtained outside wall temperature of about 65 °C and shorten start-up time to about 60 minutes. The use of thermal radiation shield can also improve the efficiency of the electric power supply and increase the operating temperature for nitriding process. Test for nitriding obtained increase of hardness 1.33 times for the original camshaft (genuine parts) and 1.8 times for the imitation camshaft (imitation parts), the results are compared with after the tempering process at a temperature of 600 °C. For sample SS 304 was 2.45 times compared with before nitrided These results indicate that the development of manufacturing technology of plasma/ion nitriding to increase hardness of machine components and tools have been successfully able to increase the hardness, although still need to be optimized. Besides that, these devices can be developed to use for the process of carburizing and carbonitriding. (author)

The CREST-E study of creatine for Huntington disease: A randomized controlled trial.

Science.gov (United States)

Hersch, Steven M; Schifitto, Giovanni; Oakes, David; Bredlau, Amy-Lee; Meyers, Catherine M; Nahin, Richard; Rosas, Herminia Diana

2017-08-08

To investigate whether creatine administration could slow progressive functional decline in adults with early symptoms of Huntington disease. We conducted a multicenter, randomized, double-blind, placebo-controlled study of up to 40 g daily of creatine monohydrate in participants with stage I and II HD treated for up to 48 months. The primary outcome measure was the rate of change in total functional capacity (TFC) between baseline and end of follow-up. Secondary outcome measures included changes in additional clinical scores, tolerability, and quality of life. Safety was assessed by adverse events and laboratory studies. At 46 sites in North America, Australia, and New Zealand, 553 participants were randomized to creatine (275) or placebo (278). The trial was designed to enroll 650 patients, but was halted for futility after the first interim analysis. The estimated rates of decline in the primary outcome measure (TFC) were 0.82 points per year for participants on creatine, 0.70 points per year for participants on placebo, favoring placebo (nominal 95% confidence limits -0.11 to 0.35). Adverse events, mainly gastrointestinal, were significantly more common in participants on creatine. Serious adverse events, including deaths, were more frequent in the placebo group. Subgroup analysis suggested that men and women may respond differently to creatine treatment. Our data do not support the use of creatine treatment for delaying functional decline in early manifest HD. NCT00712426. This study provides Class II evidence that for patients with early symptomatic HD, creatine monohydrate is not beneficial for slowing functional decline. Copyright © 2017 The Author(s). Published by Wolters Kluwer Health, Inc. on behalf of the American Academy of Neurology.

Effects of creatine supplementation along with resistance training on urinary formaldehyde and serum enzymes in wrestlers.

Science.gov (United States)

Nasseri, Azadeh; Jafari, Afshar

2016-04-01

Formaldehyde is a cytotoxic agent produced from creatine through a metabolic pathway, and in this regard, it has been claimed that creatine supplementation could be cytotoxic. Even though the cytotoxic effects of creatine supplementation have been widely studied, yet little is known about how resistance training can alter these toxic effects. This study aimed to determine the effects of short-term creatine supplementation plus resistance training on the level of urinary formaldehyde and concentrations of serum enzymes in young male wrestlers. In a double-blind design twenty-one subjects were randomized into creatine supplementation (Cr), creatine supplementation plus resistance training (Cr + T) and placebo plus resistance training (Pl + T) groups. Participants ingested creatine (0.3 g/kg/day) or placebo for 7 days. The training protocol consisted of 3 sessions in one week, each session including three sets of 6-9 repetitions at 80-85% of one-repetition maximum for whole-body exercise. Urine and blood samples were collected at baseline and at the end of the supplementation. Creatine supplementation significantly increased the excretion rate of urinary formaldehyde in the Cr and Cr + T groups by 63.4% and 30.4%, respectively (P0.05). These findings indicate that resistance training may lower the increase of urinary formaldehyde excretion induced by creatine supplementation, suggesting that creatine consumption could be relatively less toxic when combined with resistance training.

Oral creatine supplementation attenuates muscle loss caused by limb immobilization: a systematic review

Directory of Open Access Journals (Sweden)

Camila Souza Padilha

Full Text Available Abstract Introduction: Recent studies have pointing creatine supplementation as a promising therapeutic alterna- tive in several diseases, especially myopathies and neurodegenerative disorder. Objective: elucidate the role of creatine supplementation on deleterious effect caused by limb immobilization in humans and rats. Methods: Analyzed articles were searched by three online databases, PubMed, SportDicus e Scielo. After a review and analysis, the studies were included in this review articles on effect of creatine supplementation on skeletal muscle in humans and rat, before, during and after a period of limb immobilization. Results: Studies analyzed demonstrated positive points in use of creatine supplementation as a therapeutic tool to mitigating the deleterious effects of limb immobilization, in humans and rat. Conclusion: The dataset of this literature review allows us to conclude that creatine supplementation may reduce muscle loss and/or assist in the recovery of muscle atrophy caused by immobilization and disuse in rats and humans. Also, we note that further research with better methodological rigor is needed to clarify the mechanisms by which creatine support the recovery of muscle atrophy. Moreover, these effects are positive and promising in the field of muscle rehabilitation, especially after member’s immobilization.

Creatine Deficiency Syndrome could be Missed Easily: A Case Report of Guanidinoacetate Methyltransferase Deficiency Presented with Neurodevelopmental Delay, Seizures, and Behavioral Changes, but Normal Structural MRI.

Science.gov (United States)

Pacheva, Iliyana; Ivanov, Ivan; Penkov, Marin; Kancheva, Daliya; Jordanova, Albena; Ivanova, Mariya

2016-09-01

A case with GAMT deficiency (homozygous c.64dupG mutation) presented with neurodevelopmental delay, rare seizures, behavioral disturbances, and mild hypotonia, posing diagnostic challenges. Metabolic investigations showed low creatinine in plasma and urine (guanidinoacetate couldn't be investigated) and slightly elevated lactate. MRI was normal. Correct diagnosis was possible only after MR spectroscopy was performed at age 5½ years. A homozygous c.64dupG mutation of the GAMT gene was identified in the proband. In conclusion, every case with neurodevelopmental delay or arrest, especially when accompanied by seizures, behavioral impairment, muscle hypotonia or extrapyramidal symptoms should undergo MRI with MR spectroscopy. Normal structural MRI doesn't exclude a creatine deficiency syndrome. Biochemical investigations of guanidinoacetate, creatine, and creatinine in body fluid should be done to diagnose cerebral creatine deficiency syndromes and to specify the deficient enzyme. Thus, a treatable disease will not be missed. © 2016 by the Association of Clinical Scientists, Inc.

Use of oral creatine as an ergogenic aid for increased sports performance: perceptions of adolescent athletes.

Science.gov (United States)

Ray, T R; Eck, J C; Covington, L A; Murphy, R B; Williams, R; Knudtson, J

2001-06-01

Competitive athletes, including adolescents, seek ways to gain advantage over competitors. One ergogenic aid is creatine, a naturally occurring nitrogen compound found primarily in skeletal muscle. Increasing creatine levels may prolong skeletal muscle activity, enhancing work output. A questionnaire assessing awareness and use of creatine supplementation was completed by 674 athletes from 11 high schools. Data were statistically analyzed to determine variation among groups. Of those surveyed, 75% had knowledge of creatine supplements, and 16% used creatine to enhance athletic performance. Percentage of use increased with age and grade level. Awareness and use were greater among boys than girls. Adverse effects were reported by 26%. Most athletes consumed creatine using a method inconsistent with scientific recommendations. Use of creatine by adolescent athletes is significant and inconsistent with optimal dosing. Physicians, athletic trainers, and coaches should disseminate proper information and advise these adolescent athletes.

Dietary creatine supplementation lowers hepatic triacylglycerol by increasing lipoprotein secretion in rats fed high-fat diet.

Science.gov (United States)

da Silva, Robin P; Leonard, Kelly-Ann; Jacobs, René L

2017-12-01

Recent studies have shown that dietary creatine supplementation can prevent lipid accumulation in the liver. Creatine is a small molecule that plays a large role in energy metabolism, but since the enzyme creatine kinase is not present in the liver, the classical role in energy metabolism does not hold in this tissue. Fat accumulation in the liver can lead to the development of nonalcoholic fatty liver disease (NAFLD), a progressive disease that is prevalent in humans. We have previously reported that creatine can directly influence lipid metabolism in cell culture to promote lipid secretion and oxidation. Our goal in the current study was to determine whether similar mechanisms that occur in cell culture were present in vivo. We also sought to determine whether dietary creatine supplementation could be effective in reversing steatosis. Sprague-Dawley rats were fed a high-fat diet or a high-fat diet supplemented with creatine for 5 weeks. We found that rats supplemented with creatine had significantly improved rates of lipoprotein secretion and alterations in mitochondrial function that were consistent with greater oxidative capacity. We also find that introducing creatine into a high-fat diet halted hepatic lipid accumulation in rats with fatty liver. Our results support our previous report that liver cells in culture with creatine secrete and oxidize more oleic acid, demonstrating that dietary creatine can effectively change hepatic lipid metabolism by increasing lipoprotein secretion and oxidation in vivo. Our data suggest that creatine might be an effective therapy for NAFLD. Copyright © 2017 Elsevier Inc. All rights reserved.

Machinability of nickel based alloys using electrical discharge machining process

Science.gov (United States)

Khan, M. Adam; Gokul, A. K.; Bharani Dharan, M. P.; Jeevakarthikeyan, R. V. S.; Uthayakumar, M.; Thirumalai Kumaran, S.; Duraiselvam, M.

2018-04-01

The high temperature materials such as nickel based alloys and austenitic steel are frequently used for manufacturing critical aero engine turbine components. Literature on conventional and unconventional machining of steel materials is abundant over the past three decades. However the machining studies on superalloy is still a challenging task due to its inherent property and quality. Thus this material is difficult to be cut in conventional processes. Study on unconventional machining process for nickel alloys is focused in this proposed research. Inconel718 and Monel 400 are the two different candidate materials used for electrical discharge machining (EDM) process. Investigation is to prepare a blind hole using copper electrode of 6mm diameter. Electrical parameters are varied to produce plasma spark for diffusion process and machining time is made constant to calculate the experimental results of both the material. Influence of process parameters on tool wear mechanism and material removal are considered from the proposed experimental design. While machining the tool has prone to discharge more materials due to production of high energy plasma spark and eddy current effect. The surface morphology of the machined surface were observed with high resolution FE SEM. Fused electrode found to be a spherical structure over the machined surface as clumps. Surface roughness were also measured with surface profile using profilometer. It is confirmed that there is no deviation and precise roundness of drilling is maintained.

A review of creatine supplementation in age-related diseases: more than a supplement for athletes

Science.gov (United States)

Smith, Rachel N.; Agharkar, Amruta S.; Gonzales, Eric B.

2014-01-01

Creatine is an endogenous compound synthesized from arginine, glycine and methionine. This dietary supplement can be acquired from food sources such as meat and fish, along with athlete supplement powders. Since the majority of creatine is stored in skeletal muscle, dietary creatine supplementation has traditionally been important for athletes and bodybuilders to increase the power, strength, and mass of the skeletal muscle. However, new uses for creatine have emerged suggesting that it may be important in preventing or delaying the onset of neurodegenerative diseases associated with aging. On average, 30% of muscle mass is lost by age 80, while muscular weakness remains a vital cause for loss of independence in the elderly population. In light of these new roles of creatine, the dietary supplement’s usage has been studied to determine its efficacy in treating congestive heart failure, gyrate atrophy, insulin insensitivity, cancer, and high cholesterol. In relation to the brain, creatine has been shown to have antioxidant properties, reduce mental fatigue, protect the brain from neurotoxicity, and improve facets/components of neurological disorders like depression and bipolar disorder. The combination of these benefits has made creatine a leading candidate in the fight against age-related diseases, such as Parkinson’s disease, Huntington’s disease, amyotrophic lateral sclerosis, long-term memory impairments associated with the progression of Alzheimer’s disease, and stroke. In this review, we explore the normal mechanisms by which creatine is produced and its necessary physiology, while paying special attention to the importance of creatine supplementation in improving diseases and disorders associated with brain aging and outlining the clinical trials involving creatine to treat these diseases. PMID:25664170

Evaluation of the effectiveness of training on a machine with a variable-cam.

Science.gov (United States)

Urbanik, Czesław; Staniszewski, Michał; Mastalerz, Andrzej; Karczewska, Magdalena; Lutosławska, Grażyna; Iwańska, Dagmara; Madej, Anna; Ostrowska, Elżbieta; Gwarek, Lucyna; Tkaczyk, Joanna

2013-01-01

The aim of the study was to assess the effectiveness of the training of elbow flexors through the use of 2 machines, one of which was equipped with a disc plate of constant radius, the other one with a variable-cam having a radius adjustable to muscle strength. The experiment included 45 men divided into 3 equal groups: training group A (variable-cam), training group B (circle), and control group C. The training lasted for 8 weeks, 3 times a week. In order to control the effects, the values of peak torque and power of the flexor muscles of the elbow were isokinetically measured for the angular velocities of 30°/s and 60°/s. Also taken were anthropometric measurements of the arm and the creatine kinase (CK) activity in the blood plasma. As a result of the training, significant increases of biomechanical values were noted only in group A: power increased over 20%, the peak torque over 14%. After the training, significant increases of arm circumference in the relaxed position were noted in group A (17 mm), as well as in group B (11 mm). Also, some changes in CK activity were observed between Monday and Friday in a training week. On the basis of the experimental measurements, it may be ascertained that training elbow flexor muscles on a machine with a variable-cam is more efficient for increases in strength and power, as well as for some anthropometric parameters, than training on a machine with a disc plate.

The Effects of Creatine Supplementation on Explosive Performance and Optimal Individual Postactivation Potentiation Time

Directory of Open Access Journals (Sweden)

Chia-Chi Wang

2016-03-01

Full Text Available Creatine plays an important role in muscle energy metabolism. Postactivation potentiation (PAP is a phenomenon that can acutely increase muscle power, but it is an individualized process that is influenced by muscle fatigue. This study examined the effects of creatine supplementation on explosive performance and the optimal individual PAP time during a set of complex training bouts. Thirty explosive athletes performed tests of back squat for one repetition maximum (1RM strength and complex training bouts for determining the individual optimal timing of PAP, height and peak power of a counter movement jump before and after the supplementation. Subjects were assigned to a creatine or placebo group and then consumed 20 g of creatine or carboxymethyl cellulose per day for six days. After the supplementation, the 1RM strength in the creatine group significantly increased (p < 0.05. The optimal individual PAP time in the creatine group was also significant earlier than the pre-supplementation and post-supplementation of the placebo group (p < 0.05. There was no significant difference in jump performance between the groups. This study demonstrates that creatine supplementation improves maximal muscle strength and the optimal individual PAP time of complex training but has no effect on explosive performance.

Genetic Depletion of Adipocyte Creatine Metabolism Inhibits Diet-Induced Thermogenesis and Drives Obesity.

Science.gov (United States)

Kazak, Lawrence; Chouchani, Edward T; Lu, Gina Z; Jedrychowski, Mark P; Bare, Curtis J; Mina, Amir I; Kumari, Manju; Zhang, Song; Vuckovic, Ivan; Laznik-Bogoslavski, Dina; Dzeja, Petras; Banks, Alexander S; Rosen, Evan D; Spiegelman, Bruce M

2017-10-03

Diet-induced thermogenesis is an important homeostatic mechanism that limits weight gain in response to caloric excess and contributes to the relative stability of body weight in most individuals. We previously demonstrated that creatine enhances energy expenditure through stimulation of mitochondrial ATP turnover, but the physiological role and importance of creatine energetics in adipose tissue have not been explored. Here, we have inactivated the first and rate-limiting enzyme of creatine biosynthesis, glycine amidinotransferase (GATM), selectively in fat (Adipo-Gatm KO). Adipo-Gatm KO mice are prone to diet-induced obesity due to the suppression of elevated energy expenditure that occurs in response to high-calorie feeding. This is paralleled by a blunted capacity for β3-adrenergic activation of metabolic rate, which is rescued by dietary creatine supplementation. These results provide strong in vivo genetic support for a role of GATM and creatine metabolism in energy expenditure, diet-induced thermogenesis, and defense against diet-induced obesity. Published by Elsevier Inc.

Predictive Analysis for the Thermal Diffusion of the Plasma-Assisted Machining of Superalloy Inconel-718 Based on Exponential Smoothing

Directory of Open Access Journals (Sweden)

Chen Shao-Hsien

2018-01-01

Full Text Available Nickel base and titanium base materials have been widely applied to engines in aerospace industry, and these engines are essential components of airplanes. The machining characteristics of aerospace materials may cause machining cutters to be worn down in a short time and thus reduce the accuracy of processing. The plasma-assisted machining adopted in the research is a kind of the complex machining method. In the cases of nickel base and titanium base alloys, the method can heat workpieces in an extremely short duration to soften the materials for the ease of cutting so that the cutting force, cutter wear, and machining cost will all be reduced. The research adopted plasma heating to soften parts of the materials and aimed to explore the heating of nickel base alloy. The temperature variation of the materials was investigated and measured by adjusting the current and feed velocity. Moreover, Inconel-718 superalloy was adopted for the comparison with nickel base alloy for the observation of the influence and change brought by heat, and the method of exponential smoothing was adopted to conduct the prediction and analysis of thermal diffusion for understanding the influence and change brought by electric current on nickel base materials. Finally, given the current from 20 A to 80 A and feed velocity from 1,000 mm/min to 3,000 mm/min, the influence of thermal diffusion was investigated and the related model was built.

Concentrations in beef and lamb of taurine, carnosine, coenzyme Q(10), and creatine.

Science.gov (United States)

Purchas, R W; Rutherfurd, S M; Pearce, P D; Vather, R; Wilkinson, B H P

2004-03-01

Levels of taurine, carnosine, coenzyme Q(10), and creatine were measured in beef liver and several muscles of beef and lamb and in cooked and uncooked meat. The amino acid taurine has numerous biological functions, the dipeptide carnosine is a buffer as well as an antioxidant, coenzyme Q(10) is also an antioxidant present within mitochondria, and creatine along with creatine phosphate is involved with energy metabolism in muscle. Large differences were shown for all compounds between beef cheek muscle (predominantly red fibres) and beef semitendinosus muscle (mainly white fibres), with cheek muscle containing 9.9 times as much taurine, and 3.2 times as much coenzyme Q(10), but only 65% as much creatine and 9% as much carnosine. Levels in lamb relative to beef semitendinosus muscles were higher for taurine but slightly lower for carnosine, coenzyme Q(10) and creatine. Values for all the compounds varied significantly between eight lamb muscles, possibly due in part to differences in the proportion of muscle fibre types. Slow cooking (90 min at 70 °C) of lamb longissimus and semimembranosus muscles led to significant reductions in the content of taurine, carnosine, and creatine (Plamb, but that these levels vary between muscles, between animals, and with cooking.

ALTERATIONS IN BRAIN CREATINE CONCENTRATIONS UNDER LONG-TERM SOCIAL ISOLATION (EXPERIMENTAL STUDY).

Science.gov (United States)

Koshoridze, N; Kuchukashvili, Z; Menabde, K; Lekiashvili, Sh; Koshoridze, M

2016-02-01

Stress represents one of the main problems of modern humanity. This study was done for understanding more clearly alterations in creatine content of the brain under psycho-emotional stress induced by long-term social isolation. It was shown that under 30 days social isolation creatine amount in the brain was arisen, while decreasing concentrations of synthesizing enzymes (AGAT, GAMT) and creatine transporter protein (CrT). Another important point was that such changes were accompanied by down-regulation of creatine kinase (CK), therefore the enzyme's concentration was lowered. In addition, it was observed that content of phosphocreatine (PCr) and ATP were also reduced, thus indicating down-regulation of energy metabolism of brain that is really a crucial point for its normal functioning. To sum up the results it can be underlined that long-term social isolation has negative influence on energy metabolism of brain; and as a result reduce ATP content, while increase of free creatine concentration, supposedly maintaining maximal balance for ATP amount, but here must be also noted that up-regulated oxidative pathways might have impact on blood brain barrier, resulting on its permeability.

Proteinase K processing of rabbit muscle creatine kinase

DEFF Research Database (Denmark)

Leydier, C; Andersen, Jens S.; Couthon, F

1997-01-01

Proteinase K cleaves selectively both cytosolic and mitochondrial isoforms of creatine kinase leading to the appearance of two fragments, a large N-terminal one (K1) and a small C-terminal peptide (K2) which remain associated together. The loss of enzymatic activity correlates with the extent...... of monomer cleavage. N-terminal sequencing of the K2 fragments from rabbit cytosolic and pig mitochondrial creatine kinase shows that these peptides begin with A328 and A324, respectively. Electrospray ionization mass spectrometry demonstrates that K2 peptide is composed of 53 residues (A328-K380). However...

URINARY CREATINE AT REST AND AFTER REPEATED SPRINTS IN ATHLETES: A PILOT STUDY

OpenAIRE

Bezrati-Benayed, I.; Nasrallah, F.; Feki, M.; Chamari, K.; Omar, S.; Alouane-Trabelsi, L.; Ben Mansour, A.; Kaabachi, N.

2014-01-01

Creatine plays a key role in muscle function and its evaluation is important in athletes. In this study, urinary creatine concentration was measured in order to highlight its possible significance in monitoring sprinters. The study included 51 sprinters and 25 age- and sex-matched untrained subjects as a control group. Body composition was measured and dietary intake estimated. Urine samples were collected before and after standardized physical exercise. Creatine was assessed by gas chromatog...

Immunological measurements on the disappearance of creatine kinase MM from the circulation. [Immunoradiometric assay

Energy Technology Data Exchange (ETDEWEB)

Wevers, R A; van Landeghem, A A.J.; Mul-Steinbusch, M W.F.J.; Bijdendijk, J G; Weerts, P; Kloeg, P; Soons, J B.J. [Rijksuniversiteit Utrecht (Netherlands)

1983-07-15

Both a two-site immunoradiometric assay and a two-site enzyme-linked immunosorbent assay for creatine kinase MM are described. Linearity, reproducibility and cross-reactivity of the assays are satisfactory. Creatine kinase MM incubated in a pH-controlled serum matrix loses its activity, but has its antigenic determinants affected as well. Of all the techniques used, only the immunoradiometric assay is capable of measuring part of the inactivated enzyme. Measurements with this assay on the sera of patients after a myocardial infarction show identical results for enzyme activity and creatine kinase protein quantity. The in vitro disappearance rate of creatine kinase activity is slow compared with the in vivo half-life of the enzyme. These two observations lead to the conclusion that creatine kinase is removed from the circulation long before it is inactivated in the blood stream.

The effects of creatine supplementation on selected factors of tennis specific training

NARCIS (Netherlands)

Pluim, B.M.; Ferrauti, A.; Broekhof, F.; Deutekom, M.; Gotzmann, A.; Kuipers, H.; Weber, K.

2006-01-01

BACKGROUND: Creatine supplementation is popular among tennis players but it is not clear whether it actually enhances tennis performance. OBJECTIVES: To examine the effects of creatine supplementation on tennis specific performance indices. METHODS: In a randomised, double blind design, 36

The Influence of Creatine Monohydrate on Strength and Endurance After Doing Physical Exercise With Maximum Intensity

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Asrofi Shicas Nabawi

2017-11-01

Full Text Available The purpose of this study was: (1 to analyze the effect of creatine monohydrate to give strength after doing physical exercise with maximum intensity, towards endurance after doing physical exercise with maximum intensity, (2 to analyze the effect of non creatine monohydrate to give strength after doing physical exercise with maximum intensity, towards endurance after doing physical exercise with maximum intensity, (3 to analyze the results of the difference by administering creatine and non creatine on strength and endurance after exercise with maximum intensity. This type of research used in this research was quantitative with quasi experimental research methods. The design of this study was using pretest and posttest control group design, and data analysis was using a paired sample t-test. The process of data collection was done with the test leg muscle strength using a strength test with back and leg dynamometer, sit ups test with 1 minute sit ups, push ups test with push ups and 30 seconds with a VO2max test cosmed quart CPET during the pretest and posttest. Furthermore, the data were analyzed using SPSS 22.0 series. The results showed: (1 There was the influence of creatine administration against the strength after doing exercise with maximum intensity; (2 There was the influence of creatine administration against the group endurance after doing exercise with maximum intensity; (3 There was the influence of non creatine against the force after exercise maximum intensity; (4 There was the influence of non creatine against the group after endurance exercise maximum intensity; (5 The significant difference with the provision of non creatine and creatine from creatine group difference delta at higher against the increased strength and endurance after exercise maximum intensity. Based on the above analysis, it can be concluded that the increased strength and durability for each of the groups after being given a workout.

Cloning and characterization of the promoter regions from the parent and paralogobs creatine transporter genes

NARCIS (Netherlands)

Ndika, J.D.T.; Lusink, V.; Beaubrun, C.; Kanhai, W.; Martinez-Munoz, C.; Jakobs, C.A.J.M.; Salomons, G.S.

2014-01-01

Interconversion between phosphocreatine and creatine, catalyzed by creatine kinase is crucial in the supply of ATP to tissues with high energy demand. Creatine's importance has been established by its use as an ergogenic aid in sport, as well as the development of intellectual disability in patients

Observation of enhanced electric field in an RF-plugged sheet plasma in the RFC-XX-M open-ended machine

International Nuclear Information System (INIS)

Oda, T.; Takiyama, K.; Kadota, K.

1987-12-01

We report nonperturbing observation of the electric field in the sheet plasma for RF end-plugging on the RFC XX-M open-ended machine by using the Stark effect with a combined technique of beam-probe and laser-induced fluorescence. Under the optimum condition for the RF plugging, enhanced electric field is found in the sheet plasma by about 2.5 times with respect to the electric field when no plasma is produced. The field spatial profile is also measured, which is discussed in connection with the electrostatic eigenmode. (author)

The effects of creatine supplementation on selected factors of tennis specific training

NARCIS (Netherlands)

Pluim, B. M.; Ferrauti, A.; Broekhof, F.; Deutekom, M.; Gotzmann, A.; Kuipers, H.; Weber, K.

2006-01-01

Creatine supplementation is popular among tennis players but it is not clear whether it actually enhances tennis performance. To examine the effects of creatine supplementation on tennis specific performance indices. In a randomised, double blind design, 36 competitive male tennis players (24

THE EFFECT OF CREATINE SUPPLEMENTATION ON ATHLETE ISOKINETIC PERFORMANCE

OpenAIRE

Erkan Faruk ŞİRİN; Suzan YALÇIN

2009-01-01

The purpose of this study is to find the effects of Creatin Monohydrate (CrH2O) on athlete performance (isokinetic power measured as a total workout) used as an ergojenic aid in long-term (6 weeks) supplementation. There are 38 participants willing to join to the study. Their ages are between 20 and 27. All of them are choosed from active athletes. From the findings of this study; all the participants’ in the creatin group have increased the total workout production in all cycles of isokineti...

Screening for primary creatine deficiencies in French patients with unexplained neurological symptoms

NARCIS (Netherlands)

Cheillan, D.; Curt, M.J.; Briand, G.; Salomons, G.S.; Mention-Mulliez, K.; Dobbelaere, D.; Cuisset, J.M.; Lion-Francois, L.; Portes, V.D.; Chabli, A.; Valayannopoulos, V.; Benoist, J.F.; Pinard, J.M.; Simard, G.; Douay, O.; Deiva, K.; Afenjar, A.; Heron, D.; Rivier, F.; Chabrol, B.; Prieur, F.; Cartault, F.; Pitelet, G.; Goldenberg, A.; Bekri, S.; Gerard, M.; Delorme, R.; Tardieu, M.; Porchet, N.; Vianey-Saban, C.; Vamecq, J.

2012-01-01

A population of patients with unexplained neurological symptoms from six major French university hospitals was screened over a 28-month period for primary creatine disorder (PCD). Urine guanidinoacetate (GAA) and creatine:creatinine ratios were measured in a cohort of 6,353 subjects to identify PCD

Creatine as a booster for human brain function. How might it work?

Science.gov (United States)

Rae, Caroline D; Bröer, Stefan

2015-10-01

Creatine, a naturally occurring nitrogenous organic acid found in animal tissues, has been found to play key roles in the brain including buffering energy supply, improving mitochondrial efficiency, directly acting as an anti-oxidant and acting as a neuroprotectant. Much of the evidence for these roles has been established in vitro or in pre-clinical studies. Here, we examine the roles of creatine and explore the current status of translation of this research into use in humans and the clinic. Some further possibilities for use of creatine in humans are also discussed. Copyright © 2015 Elsevier Ltd. All rights reserved.

Effect of creatine on aerobic and anaerobic metabolism in skeletal muscle in swimmers.

OpenAIRE

Thompson, C H; Kemp, G J; Sanderson, A L; Dixon, R M; Styles, P; Taylor, D J; Radda, G K

1996-01-01

OBJECTIVE: To examine the effect of a relatively low dose of creatine on skeletal muscle metabolism and oxygen supply in a group of training athletes. METHODS: 31P magnetic resonance and near-infrared spectroscopy were used to study calf muscle metabolism in a group of 10 female members of a university swimming team. Studies were performed before and after a six week period of training during which they took either 2 g creatine daily or placebo. Calf muscle metabolism and creatine/choline rat...

Cardiac Troponin I, Creatine Phosphokinase and Myoglobine Levels in Preeclampsia

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Ahmet Kale

2005-01-01

Full Text Available To evaluate minor myocardial injury in preeclamptic pregnancies by serum markers of cardiac troponin-I, creatine phosphokinase and myoglobine. Group I consisted of 45 preeclamptic pregnancies, Group 2 consisted of uncomplicated pregnancies. The groups were compared for maternal age, parity, mean troponin–I, creatine phosphokinase and myoglobine values. Student-t test were used in statistical analyses. Significance was accepted as p<0.05. Cardiac troponin-I levels were statistically significantly higher in preeclamptic pregnancies (0,97 ± 0,11ng/ml than control groups (0,12 ± 0.09 ng/ml (p<0.001. No statistically significant difference was found with mean levels of creatine phosphokinase and myoglobin levels between two groups. Higher values of troponin-I’in preeclamptic patients is thought to be a result of myocardial injury and associated with pregnancy-induced hypertension.

Radioimmunoassay measurement of creatine kinase BB in the serum of schizophrenic patients

Energy Technology Data Exchange (ETDEWEB)

Lerner, M H; Friedhoff, A J [New York Univ., NY (USA). Medical Center

1980-10-23

Brain type creatine kinase (BB) isoenzyme was measured using a highly sensitive and specific radioimmunoassay procedure (limit of detection, 1 ..mu..g/l of sample) in two schizophrenic populations, an acute non-medicated group consisting of 35 subjects and a chronic group of 15 subjects. Since the assay can also measure the B subunit of MB isoenzyme, patients were selected so as to exclude subjects with possible heart, kidney or other ailments which might result in an increased serum creatine kinase B subunit. Both the acute schizophrenics (3.0 +- 0.23) x S.E.M. and the chronic schizophrenics (2.9 +- 0.33) had serum levels of creatine kinase BB similar to those of controls (2.8 +- 0.21) and non-cardiac patients (3.5 +- 0.58). Patients having myocardial infarction or neurovascular surgery had elevated creatine kinase B subunit. Similar but much less sensitive quantitative results were obtained using agarose multizonal electrophoresis.

Radioimmunoassay measurement of creatine kinase BB in the serum of schizophrenic patients

International Nuclear Information System (INIS)

Lerner, M.H.; Friedhoff, A.J.

1980-01-01

Brain type creatine kinase (BB) isoenzyme was measured using a highly sensitive and specific radioimmunoassay procedure (limit of detection, 1 μg/l of sample) in two schizophrenic populations, an acute non-medicated group consisting of 35 subjects and a chronic group of 15 subjects. Since the assay can also measure the B subunit of MB isoenzyme, patients were selected so as to exclude subjects with possible heart, kidney or other ailments which might result in an increased serum creatine kinase B subunit. Both the acute schizophrenics (3.0 +- 0.23) x S.E.M. and the chronic schizophrenics (2.9 +- 0.33) had serum levels of creatine kinase BB similar to those of controls (2.8 +- 0.21) and non-cardiac patients (3.5 +- 0.58). Patients having myocardial infarction or neurovascular surgery had elevated creatine kinase B subunit. Similar but much less sensitive quantitative results were obtained using agarose multizonal electrophoresis. (Auth.)

Radioimmunoassay of creatine kinase BB isoenzyme

International Nuclear Information System (INIS)

Geng Jianguo

1988-01-01

A radioimmunoassay of creatine kinase BB isoenzyme (CK-BB) was developed by using CK-BB purified from human brain. The CK-BB antiserum was raised by immunizing rabbite and 125 I-CK-BB iodinated with Bolton-Hunter reagent. The affinity constant was 3.0 x 10 9 mol/L. No cross reactions with creatine kinase MM isoenzyme and neuron-specific enolase were found. The measuring range was 3.5 x 10 -8 ∼ 1.2 x 10 -5 mmol/L, the average recovery rate 97.5%, with the inter and intrassay CV 3.1% and 12%, respectively. The average serum CK-BB concentration in 83 normal persons was 1.5 x 10 -7 +- 8.1 x 10 -8 mmol/L, quite different from the values of acute myocardial infarction (5.2 x 10 -6 +- 1.2 x 10 -4 mmol/L, n = 28) and cerebral vascular accident (8.4 x 10 -4 +- 5.0 x 10 -4 mmol/L, n = 10)

Effects of creatine supplementation on high-intensity intermittent exercise: discrepancies and methodological appraisals

Directory of Open Access Journals (Sweden)

Bruno Gualano

2008-07-01

Full Text Available http://dx.doi.org/10.5007/1980-0037.2008v10n2p189 After a brief review of the literature on the effects of creatine supplementation on high-intensity intermittent exercise performance, the main aim of this study was to discuss methodological differences between studies which could explain the discrepancies observed in the literature. The effects of creatine supplementation on high-intensity intermittent exercise performance have been investigated in depth. Although the results of much research demonstrates the effi cacy of this supplement, there is just as much evidence that does not support this ergogenic effect. The explanation for this divergence appears to be multifactorial, although it is always linked to methodological characteristics. Study design (crossover or parallel groups, individual variability of muscular creatine content, chronic high meat intake, sample size, exercise protocol characteristics (body weight dependence and time between series, and gender and age all differ between studies and are potentially the variables responsible, to differing extents, for the discrepancies observed in the literature. Studies involving young males, with parallel group design, adequate statistical power, control of the incorporation of creatine into muscles, food intake assessment and intermittent exercise protocols in which performance is independent of body weight and with rest-recovery intervals of 1 to 6 minutes, usually produce positive results. The many methodological factors which can contribute to divergence on the ergogenic effects of creatine should be considered in futures studies, as well as when prescribing creatine supplementation.

Mobility of creatine phosphokinase and beta-enolase in cultured muscle cells.

Science.gov (United States)

Arrio-Dupont, M; Foucault, G; Vacher, M; Douhou, A; Cribier, S

1997-11-01

The diffusion of beta-enolase and creatine phosphokinase in muscle cells has been studied by modulated fringe pattern photobleaching. Beta-enolase is mobile in the sarcoplasm. At 20 degrees C, the diffusion coefficient is 13.5 +/- 2.5 microm2 s(-1) in the cytosol and 56 microm2 s(-1) in aqueous media. As in the case of dextrans of the same hydrodynamic radius, its mobility is hindered by both the crowding of the fluid phase of the cytoplasm and the screening effect due to myofilaments. A fraction of creatine phosphokinase is mobile in the sarcoplasm. Its diffusion coefficient in the cytosol, 4.5 +/- 1 microm2 s(-1), is lower than that of the dextran of equivalent size. The other fraction (20 to 50%) is very slightly mobile, with an apparent diffusion coefficient varying from 0.0035 to 0.043 microm2 s(-1). This low mobility might be attributed to exchange between free and bound creatine phosphokinase. The bound fraction of the endogenous enzyme was localized by immunocytofluorescence on the cultured muscle cells. Our results favor a localization of bound cytosolic creatine phosphokinase on the M-line and a diffuse distribution in all myotubes.

CREATINE SUPPLEMENTATION AND EXERCISE PERFORMANCE: A BRIEF REVIEW

Directory of Open Access Journals (Sweden)

Stephen P. Bird

2003-12-01

Full Text Available During the past decade, the nutritional supplement creatine monohydrate has been gaining popularity exponentially. Introduced to the general public in the early 1990s, shortly after the Barcelona Olympic Games, creatine (Cr has become one of the most widely used nutritional supplements or ergogenic aids, with loading doses as high as 20-30 g·day-1 for 5-7 days typical among athletes. This paper reviews the available research that has examined the potential ergogenic value of creatine supplementation (CrS on exercise performance and training adaptations. Short-term CrS has been reported to improve maximal power/strength, work performed during sets of maximal effort muscle contractions, single-effort sprint performance, and work performed during repetitive sprint performance. During training CrS has been reported to promote significantly greater gains in strength, fat free mass, and exercise performance primarily of high intensity tasks. However, not all studies demonstrate a beneficial effect on exercise performance, as CrS does not appear to be effective in improving running and swimming performance. CrS appears to pose no serious health risks when taken at doses described in the literature and may enhance exercise performance in individuals that require maximal single effort and/or repetitive sprint bouts

Cloning and characterization of the promoter regions from the parent and paralogous creatine transporter genes.

Science.gov (United States)

Ndika, Joseph D T; Lusink, Vera; Beaubrun, Claudine; Kanhai, Warsha; Martinez-Munoz, Cristina; Jakobs, Cornelis; Salomons, Gajja S

2014-01-10

Interconversion between phosphocreatine and creatine, catalyzed by creatine kinase is crucial in the supply of ATP to tissues with high energy demand. Creatine's importance has been established by its use as an ergogenic aid in sport, as well as the development of intellectual disability in patients with congenital creatine deficiency. Creatine biosynthesis is complemented by dietary creatine uptake. Intracellular transport of creatine is carried out by a creatine transporter protein (CT1/CRT/CRTR) encoded by the SLC6A8 gene. Most tissues express this gene, with highest levels detected in skeletal muscle and kidney. There are lower levels of the gene detected in colon, brain, heart, testis and prostate. The mechanism(s) by which this regulation occurs is still poorly understood. A duplicated unprocessed pseudogene of SLC6A8-SLC6A10P has been mapped to chromosome 16p11.2 (contains the entire SLC6A8 gene, plus 2293 bp of 5'flanking sequence and its entire 3'UTR). Expression of SLC6A10P has so far only been shown in human testis and brain. It is still unclear as to what is the function of SLC6A10P. In a patient with autism, a chromosomal breakpoint that intersects the 5'flanking region of SLC6A10P was identified; suggesting that SLC6A10P is a non-coding RNA involved in autism. Our aim was to investigate the presence of cis-acting factor(s) that regulate expression of the creatine transporter, as well as to determine if these factors are functionally conserved upstream of the creatine transporter pseudogene. Via gene-specific PCR, cloning and functional luciferase assays we identified a 1104 bp sequence proximal to the mRNA start site of the SLC6A8 gene with promoter activity in five cell types. The corresponding 5'flanking sequence (1050 bp) on the pseudogene also had promoter activity in all 5 cell lines. Surprisingly the pseudogene promoter was stronger than that of its parent gene in 4 of the cell lines tested. To the best of our knowledge, this is the first

Creatine Supplementation and Skeletal Muscle Metabolism for Building Muscle Mass- Review of the Potential Mechanisms of Action.

Science.gov (United States)

Farshidfar, Farnaz; Pinder, Mark A; Myrie, Semone B

2017-01-01

Creatine, a very popular supplement among athletic populations, is of growing interest for clinical applications. Since over 90% of creatine is stored in skeletal muscle, the effect of creatine supplementation on muscle metabolism is a widely studied area. While numerous studies over the past few decades have shown that creatine supplementation has many favorable effects on skeletal muscle physiology and metabolism, including enhancing muscle mass (growth/hypertrophy); the underlying mechanisms are poorly understood. This report reviews studies addressing the mechanisms of action of creatine supplementation on skeletal muscle growth/hypertrophy. Early research proposed that the osmotic effect of creatine supplementation serves as a cellular stressor (osmosensing) that acts as an anabolic stimulus for protein synthesis signal pathways. Other reports indicated that creatine directly affects muscle protein synthesis via modulations of components in the mammalian target of rapamycin (mTOR) pathway. Creatine may also directly affect the myogenic process (formation of muscle tissue), by altering secretions of myokines, such as myostatin and insulin-like growth factor-1, and expressions of myogenic regulatory factors, resulting in enhanced satellite cells mitotic activities and differentiation into myofiber. Overall, there is still no clear understanding of the mechanisms of action regarding how creatine affects muscle mass/growth, but current evidence suggests it may exert its effects through multiple approaches, with converging impacts on protein synthesis and myogenesis. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

Development of Ratiometric Fluorescent Biosensors for the Determination of Creatine and Creatinine in Urine.

Science.gov (United States)

Duong, Hong Dinh; Rhee, Jong Il

2017-11-08

In this study, the oxazine 170 perchlorate (O17)-ethylcellulose (EC) membrane was successfully exploited for the fabrication of creatine- and creatinine-sensing membranes. The sensing membrane exhibited a double layer of O17-EC membrane and a layer of enzyme(s) entrapped in the EC and polyurethane hydrogel (PU) matrix. The sensing principle of the membranes was based on the hydrolytic catalysis of urea, creatine, and creatinine by the enzymes. The reaction end product, ammonia, reacted with O17-EC membrane, resulting in the change in fluorescence intensities at two emission wavelengths ( λ em = 565 and 625 nm). Data collected from the ratio of fluorescence intensities at λ em = 565 and 625 nm were proportional to the concentrations of creatine or creatinine. Creatine- and creatinine-sensing membranes were very sensitive to creatine and creatinine at the concentration range of 0.1-1.0 mM, with a limit of detection (LOD) of 0.015 and 0.0325 mM, respectively. Furthermore, these sensing membranes showed good features in terms of response time, reversibility, and long-term stability. The interference study demonstrated that some components such as amino acids and salts had some negative effects on the analytical performance of the membranes. Thus, the simple and sensitive ratiometric fluorescent sensors provide a simple and comprehensive method for the determination of creatine and creatinine concentrations in urine.

Creatine Supplementation Increases Total Body Water in Soccer Players: a Deuterium Oxide Dilution Study.

Science.gov (United States)

Deminice, R; Rosa, F T; Pfrimer, K; Ferrioli, E; Jordao, A A; Freitas, E

2016-02-01

This study aimed to evaluate changes in total body water (TBW) in soccer athletes using a deuterium oxide dilution method and bioelectrical impedance (BIA) formulas after 7 days of creatine supplementation. In a double-blind controlled manner, 13 healthy (under-20) soccer players were divided randomly in 2 supplementation groups: Placebo (Pla, n=6) and creatine supplementation (CR, n=7). Before and after the supplementation period (0.3 g/kg/d during 7 days), TBW was determined by deuterium oxide dilution and BIA methods. 7 days of creatine supplementation lead to a large increase in TBW (2.3±1.0 L) determined by deuterium oxide dilution, and a small but significant increase in total body weight (1.0±0.4 kg) in Cr group compared to Pla. The Pla group did not experience any significant changes in TBW or body weight. Although 5 of 6 BIA equations were sensitive to determine TBW changes induced by creatine supplementation, the Kushner et al. 16 method presented the best concordance levels when compared to deuterium dilution method. In conclusion, 7-days of creatine supplementation increased TBW determined by deuterium oxide dilution or BIA formulas. BIA can be useful to determine TBW changes promoted by creatine supplementation in soccer athletes, with special concern for formula choice. © Georg Thieme Verlag KG Stuttgart · New York.

Serum creatine phosphokinase as prognostic indicator in the management of electrical burn

International Nuclear Information System (INIS)

Memon, A.R.; Memon, F.M.; Shaikh, B.F.

2008-01-01

To determine the mean difference of serum creatine phosphokinase according to the extent of tissue damage and prognosis of the patients suffering from electrical burn injuries. During the study period, 38 patients with electrical burn injuries were enrolled. Victims of electrical burns with evidence of myocardial injury were excluded. Following admission, serum creatine phosphokinase was measured serially on 10 consecutive occasions. The data was later analyzed statistically using SPSS-10.0. Of the 38 patients, the mean age of the victims was 28 years, with males dominating the study population (82%). A statistically significant association was found between the level of serum creatine phosphokinase and likelihood of death (p=0.000). It was also found that serial monitoring of this enzyme can be used as prognostic indicator in the management of electrical burns injury. The level of creatine phosphokinase increased with the degree of tissue injuries in patients with electrical burns. This prognostic value is of great importance in the local setup, where sophisticated investigations to detect extent of injuries are not available. (author)

Creatine and the Male Adolescent Athlete

Science.gov (United States)

Schumaker, Shauna; Eyers, Christina; Cappaert, Thomas

2012-01-01

As the level of competition in youth sports increases, so does athletes' vulnerability to experimenting with performance-enhancing aids (PEAs) at alarmingly young ages. One of the more commonly used PEAs is a supplement called creatine, which has the ability to generate muscular energy, allowing athletes to train at higher intensities for longer…

Ammonium-induced impairment of axonal growth is prevented through glial creatine.

OpenAIRE

Braissant, O.; Henry, H.; Villard, A.M.; Zurich, M.G.; Loup, M.; Eilers, B.; Parlascino, G.; Matter, E.; Boulat, O.; Honegger, P.; Bachmann, C.

2002-01-01

Hyperammonemia in neonates and infants affects brain development and causes mental retardation. We report that ammonium impaired cholinergic axonal growth and altered localization and phosphorylation of intermediate neurofilament protein in rat reaggregated brain cell primary cultures. This effect was restricted to the phase of early maturation but did not occur after synaptogenesis. Exposure to NH4Cl decreased intracellular creatine, phosphocreatine, and ADP. We demonstrate that creatine cot...

International Society of Sports Nutrition position stand: safety and efficacy of creatine supplementation in exercise, sport, and medicine

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Kreider, Richard B.; Kalman, Douglas S.; Antonio, Jose; Ziegenfuss, Tim N.; Wildman, Robert; Collins, Rick; Candow, Darren G.; Kleiner, Susan M.; Almada, Anthony L.; Lopez, Hector L.

2017-01-01

Creatine is one of the most popular nutritional ergogenic aids for athletes. Studies have consistently shown that creatine supplementation increases intramuscular creatine concentrations which may help explain the observed improvements in high intensity exercise performance leading to greater training adaptations. In addition to athletic and exercise improvement, research has shown that creatine supplementation may enhance post-exercise recovery, injury prevention, thermoregulation, rehabilit...

EXERCISE PERFORMANCE AND MUSCLE CONTRACTILE PROPERTIES AFTER CREATINE MONOHYDRATE SUPPLEMENTATION IN AEROBIC-ANAEROBIC TRAINING RATS

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Nickolay Boyadjiev

2007-12-01

Full Text Available The purpose of this study was to investigate the effects of creatine monohydrate supplementation on exercise performance and contractile variables in aerobic-anaerobic training rats. Twenty 90-day-old male Sprague Dawley rats were divided into two groups - creatine (Cr and controls (K. The creatine group received creatine monohydrate as a nutritional supplement, whereas the control group was given placebo. Both groups were trained 5 days a week on a treadmill for 20 days in a mixed (aerobic-anaerobic metabolic working regimen (27 m·min-1, 15% elevation for 40 min. The exercise performance (sprint-test, contractile properties (m. tibialis anterior, oxidative enzyme activity (SDH, LDH, NADH2 in m. soleus and blood hematological and chemical variables were assessed in the groups at the end of the experiment. It was found out that creatine supplementation improved the exercise performance after 20 days of administration in a dose of 60 mg per day on the background of a mixed (aerobic-anaerobic exercise training. At the end of the trial the Cr-group demonstrated better values for the variables which characterize the contractile properties of m. tibialis anterior containing predominantly types IIA and IIB muscle fibers. On the other hand, a higher oxidative capacity was found out in m. soleus (type I muscle fibers as a result of 20-day creatine supplementation. No side effects of creatine monohydrate supplementation were assessed by the hematological and blood biochemical indices measured in this study

Determination of Local Magnetic Dipole Moment of the Plasma at the PUPR Cusp-Mirror Machine

International Nuclear Information System (INIS)

Leal-Quiros, Edbertho; Prelas, Mark

2006-01-01

A novel diagnostic that allows measurement of the magnetic moment μ has been designed. The μ-Analyzer consists of a Directional Energy Analyzer and a Magnetic Hall Probe in the same detector miniature case. The Directional Energy Analyzer measures the ion temperature in the perpendicular direction to the magnetic field. On the other side, the Hall Probe measures the magnetic field. The μ-Analyzer is a miniature analyzer to avoid plasma perturbation. This allows the measurement of the ion temperature and the local magnetic field at the same point at the same time, therefore μ, the first adiabatic invariant is found. From the above parameters, the local Larmor radius also will be calculated. From the analysis of the data simultaneously in time and space, the μ of the Local Plasma has been determined. This result is a very important quantity, among other properties that permit one to know the stability of the magnetic confinement device using the MHD Stability Criterium, and also very important in Space Plasma Research. In addition to the above, a direct measurement of the Larmor radius of each position is also possible. The experiments have been made in a Cusp/Mirror Plasma Machine where plasma parameters such as Density and Temperature are relatively easy to change in a very wide range

Influence of creatine supplementation on indicators of glucose metabolism in skeletal muscle of exercised rats

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Michel Barbosa de Araújo

2013-12-01

Full Text Available The purpose of this study was to evaluate the effect of creatine supplementation in the diet on indicators of glucose metabolism in skeletal muscle of exercised rats. Forty Wistar adult rats were distributed into four groups for eight weeks: 1 Control: sedentary rats that received balanced diet; 2 Creatine control: sedentary rats that received supplementation of 2% creatine in the balanced diet; 3 Trained: rats that ran on a treadmill at the Maximal Lactate Steady State and received balanced diet; and 4 Supplemented-trained: rats that ran on a treadmill at the Maximal Lactate Steady State and received creatine supplementation (2% in the balanced diet. The hydric intake increased and the body weight gain decreased in the supplemented-trained group. In the soleus muscle, the glucose oxidation increased in both supplemented groups. The production of lactate and glycemia during glucose tolerance test decreased in the supplemented-trained group. Creatine supplementation in conjunction with exercise training improved muscular glycidic metabolism of rats.

Serum creatine kinase isoenzymes in children with osteogenesis imperfecta.

Science.gov (United States)

D'Eufemia, P; Finocchiaro, R; Zambrano, A; Lodato, V; Celli, L; Finocchiaro, S; Persiani, P; Turchetti, A; Celli, M

2017-01-01

This study evaluates serum creatine kinase isoenzyme activity in children with osteogenesis imperfecta to determine its usefulness as a biochemical marker during treatment with bisphosphonate. The changes of creatine kinase (CK) isoenzyme activity during and after discontinuation therapy were observed. These results could be useful in addressing over-treatment risk prevention. The brain isoenzyme of creatine kinase (CKbb) is highly expressed in mature osteoclasts during osteoclastogenesis, thus plays an important role in bone resorption. We previously identified high serum CKbb levels in 18 children with osteogenesis imperfect (OI) type 1 treated for 1 year with bisphosphonate (neridronate). In the present study, serum CK isoenzymes were evaluated in the same children with continuous versus discontinued neridronate treatment over a further 2-year follow-up period. This study included 18 children with OI type 1, 12 with continued (group A) and 6 with ceased (group B) neridronate treatment. Auxological data, serum biochemical markers of bone metabolism, bone mineral density z-score, and serum total CK and isoenzyme activities were determined in both groups. Serum CKbb was progressively and significantly increased in group A (p < 0.004) but rapidly decreased to undetectable levels in group B. In both groups, the cardiac muscle creatine kinase isoenzyme (CKmb) showed a marked decrease, while serum C-terminal telopeptide (CTx) levels were almost unchanged. This study provides evidence of the cumulative effect of neridronate administration in increasing serum CKbb levels and the reversible effect after its discontinuation. This approach could be employed for verifying the usefulness of serum CKbb as a biochemical marker in patients receiving prolonged bisphosphonate treatment. Moreover, the decreased serum CKmb levels suggest a systemic effect of these drugs.

Radioimmunoassay of creatine kinase BB isoenzyme

Energy Technology Data Exchange (ETDEWEB)

Jianguo, Geng [Shanghai Medical Univ. (China). Zhongshan Hospital; and others

1988-11-01

A radioimmunoassay of creatine kinase BB isoenzyme (CK-BB) was developed by using CK-BB purified from human brain. The CK-BB antiserum was raised by immunizing rabbite and {sup 125}I-CK-BB iodinated with Bolton-Hunter reagent. The affinity constant was 3.0 x 10{sup 9} mol/L. No cross reactions with creatine kinase MM isoenzyme and neuron-specific enolase were found. The measuring range was 3.5 x 10{sup -8} {approx} 1.2 x 10{sup -5} mmol/L, the average recovery rate 97.5%, with the inter and intrassay CV 3.1% and 12%, respectively. The average serum CK-BB concentration in 83 normal persons was 1.5 x 10{sup -7} +- 8.1 x 10{sup -8} mmol/L, quite different from the values of acute myocardial infarction (5.2 x 10{sup -6} +- 1.2 x 10{sup -4} mmol/L, n = 28) and cerebral vascular accident (8.4 x 10{sup -4} +- 5.0 x 10{sup -4} mmol/L, n = 10).

Effects of creatine supplementation on cardiac autonomic functions in bodybuilders.

Science.gov (United States)

Mert, Kadir Uğur; Ilgüy, Serdar; Dural, Muhammet; Mert, Gurbet Özge; Özakin, Engin

2017-06-01

Bodybuilder-type workouts may affect heart rate variability (HRV), which has considerable potential to assess the role of autonomic nervous system (ANS). A scientifically designed approach is necessary for bodybuilders to achieve better results while protecting their health. In this study, we aimed to investigate HRV parameters in bodybuilders compared to healthy control subjects and effects of creatine supplementation. A total of 48 male participants (16 controls, 16 supplement (-), 16 supplement (+)) were evaluated in our study. Bodybuilders who were taking creatine supplementation were enrolled in supplement (+) group. HRV parameters were measured from 24-hour Holter recordings of all participants. When mean heart rates were compared with control group (71.5 ± 12.6 beats/min), statistically significant difference was revealed in supplement (-) group (61.8 ± 6.8 beats/min; P = 0.022) unlike supplement (+) group (69.63 ± 14.1 beats/min; P = 0.650). HRV analyses revealed significant parasympathetic shift in supplement (-) group. No significant difference was demonstrated on HRV parameters, except high frequency (P = 0.029) in supplement (+) group. Conclusively, elevated parasympathetic modulation, which is favorable cardiovascular outcome of exercise, was demonstrated in bodybuilders. However, our study also revealed that creatine supplementation attenuates this favorable effect in ANS by limiting elevation of parasympathetic modulation. Although the sympathetic slight shift is attributed to creatine supplementation, it cannot be discriminated from the effects of over training. © 2017 Wiley Periodicals, Inc.

Preparation of anti-adhesion surfaces on aluminium substrates of rubber plastic moulds using a coupling method of liquid plasma and electrochemical machining

Science.gov (United States)

Meng, Jianbing; Dong, Xiaojuan; Wei, Xiuting; Yin, Zhanmin

2014-03-01

Hard anti-adhesion surfaces, with low roughness and wear resistance, on aluminium substrates of rubber plastic moulds were fabricated via a new coupling method of liquid plasma and electrochemical machining. With the aid of liquid plasma thermal polishing and electrochemical anodic dissolution, micro/nano-scale binary structures were prepared as the base of the anti-adhesion surfaces. The anti-adhesion behaviours of the resulting aluminium surfaces were analysed by a surface roughness measuring instrument, a scanning electron microscope (SEM), a Fourier-transform infrared spectrophotometer (FTIR), an X-ray diffractometer (XRD), an optical contact angle meter, a digital Vickers micro-hardness (Hv) tester, and electronic universal testing. The results show that, after the liquid plasma and electrochemical machining, micro/nano-scale binary structures composed of micro-scale pits and nano-scale elongated boss structures were present on the sample surfaces. As a result, the anti-adhesion surfaces fabricated by the above coupling method have good anti-adhesion properties, better wear resistance and lower roughness.

Preparation of anti-adhesion surfaces on aluminium substrates of rubber plastic moulds using a coupling method of liquid plasma and electrochemical machining

Directory of Open Access Journals (Sweden)

Jianbing Meng

2014-02-01

Full Text Available Hard anti-adhesion surfaces, with low roughness and wear resistance, on aluminium substrates of rubber plastic moulds were fabricated via a new coupling method of liquid plasma and electrochemical machining. With the aid of liquid plasma thermal polishing and electrochemical anodic dissolution, micro/nano-scale binary structures were prepared as the base of the anti-adhesion surfaces. The anti-adhesion behaviours of the resulting aluminium surfaces were analysed by a surface roughness measuring instrument, a scanning electron microscope (SEM, a Fourier-transform infrared spectrophotometer (FTIR, an X-ray diffractometer (XRD, an optical contact angle meter, a digital Vickers micro-hardness (Hv tester, and electronic universal testing. The results show that, after the liquid plasma and electrochemical machining, micro/nano-scale binary structures composed of micro-scale pits and nano-scale elongated boss structures were present on the sample surfaces. As a result, the anti-adhesion surfaces fabricated by the above coupling method have good anti-adhesion properties, better wear resistance and lower roughness.

Preparation of anti-adhesion surfaces on aluminium substrates of rubber plastic moulds using a coupling method of liquid plasma and electrochemical machining

Energy Technology Data Exchange (ETDEWEB)

Meng, Jianbing, E-mail: jianbingmeng@126.com; Dong, Xiaojuan; Wei, Xiuting; Yin, Zhanmin [School of Mechanical Engineering, Shandong University of Technology, Zibo, 255049 (China)

2014-03-15

Hard anti-adhesion surfaces, with low roughness and wear resistance, on aluminium substrates of rubber plastic moulds were fabricated via a new coupling method of liquid plasma and electrochemical machining. With the aid of liquid plasma thermal polishing and electrochemical anodic dissolution, micro/nano-scale binary structures were prepared as the base of the anti-adhesion surfaces. The anti-adhesion behaviours of the resulting aluminium surfaces were analysed by a surface roughness measuring instrument, a scanning electron microscope (SEM), a Fourier-transform infrared spectrophotometer (FTIR), an X-ray diffractometer (XRD), an optical contact angle meter, a digital Vickers micro-hardness (Hv) tester, and electronic universal testing. The results show that, after the liquid plasma and electrochemical machining, micro/nano-scale binary structures composed of micro-scale pits and nano-scale elongated boss structures were present on the sample surfaces. As a result, the anti-adhesion surfaces fabricated by the above coupling method have good anti-adhesion properties, better wear resistance and lower roughness.

Edge diagnostics for tandem mirror machines

International Nuclear Information System (INIS)

Allen, S.L.

1984-01-01

The edge plasma in a tandem mirror machine shields the plasma core from cold neutral gas and impurities. A variety of diagnostics are used to measure the fueling, shielding, and confinement of the edge plasma in both the end plug and central cell regions. Fast ion gauges and residual gas analyzers measure the gas pressure and composition outside of the plasma. An array of Langmuir probes is used to measure the electron density and temperature. Extreme ultraviolet (euv) and visible spectroscopy are used to measure both the impurity and deuterium densities and to estimate the shielding factor for the core plasma. The linear geometry of a tandem mirror also allows direct measurements of the edge plasma by sampling the ions and electrons lost but the ends of the machine. Representative data obtained by these diagnostics during operation of the Tandem Mirror Experiment (TMX) and Tandem Mirror Experiment-Upgrade (TMX-U) experiments are presented. Diagnostics that are currently being developed to diagnose the edge plasma are also discussed

Structural changes of creatine kinase upon substrate binding.

Science.gov (United States)

Forstner, M; Kriechbaum, M; Laggner, P; Wallimann, T

1998-08-01

Small-angle x-ray scattering was used to investigate structural changes upon binding of individual substrates or a transition state analog complex (TSAC; Mg-ADP, creatine, and KNO3) to creatine kinase (CK) isoenzymes (dimeric muscle-type (M)-CK and octameric mitochondrial (Mi)-CK) and monomeric arginine kinase (AK). Considerable changes in the shape and the size of the molecules occurred upon binding of Mg-nucleotide or TSAC. The radius of gyration of Mi-CK was reduced from 55.6 A (free enzyme) to 48.9 A (enzyme plus Mg-ATP) and to 48.2 A (enzyme plus TSAC). M-CK showed similar changes from 28.0 A (free enzyme) to 25.6 A (enzyme plus Mg-ATP) and to 25.5 A (enzyme plus TSAC). Creatine alone did not lead to significant changes in the radii of gyration, nor did free ATP or ADP. AK also showed a change of the radius of gyration from 21.5 A (free enzyme) to 19.7 A (enzyme plus Mg-ATP), whereas with arginine alone only a minor change could be observed. The primary change in structure as seen with monomeric AK seems to be a Mg-nucleotide-induced domain movement relative to each other, whereas the effect of substrate may be of local order only. In CK, however, additional movements have to be involved.

Effect on hemo-dialysis on concentration of lactate dehyrogenase, creatine kinase and a-amylase in renal failure

International Nuclear Information System (INIS)

Modawe, G. O. H.; Idris, O. F.

2009-01-01

This study was conducted to compare the concentration of plasma enzymes in chronic renal failure pre dialysis (group A) and post dialysis (group B), and evaluate the concentration of these enzymes between pre and post dialysis. The study was performed in 25 samples of Sudanese patients (chronic renal failure) and compared with 15 samples as the control groups. plasma samples were analyzed using spectrophotometric methods, plasma concentration of these enzymes showed increase in chronic renal failure pre and post dialysis. The mean values of lactate dehydrogenase pre dialysis was 259IU/L, post dialysis was 276IU/L, the mean of creatine kinase pre dialysis was 252IU/L, and post dialysis was 241 IU/L but the mean of amylase pre and post dialysis was the same 144 IU/L. This study showed that there was no difference of concentration of amylase enzyme, but the different in concentration of CK and LDH between pre and post dialysis during chronic renal failure depend on normal range of this enzyme in control groups.(Author)

Exchange rates of creatine kinase metabolites: feasibility of imaging creatine by chemical exchange saturation transfer MRI.

Science.gov (United States)

Haris, Mohammad; Nanga, Ravi Prakash Reddy; Singh, Anup; Cai, Kejia; Kogan, Feliks; Hariharan, Hari; Reddy, Ravinder

2012-11-01

Creatine (Cr), phosphocreatine (PCr) and adenosine-5-triphosphate (ATP) are major metabolites of the enzyme creatine kinase (CK). The exchange rate of amine protons of CK metabolites at physiological conditions has been limited. In the current study, the exchange rate and logarithmic dissociation constant (pKa) of amine protons of CK metabolites were calculated. Further, the chemical exchange saturation transfer effect (CEST) of amine protons of CK metabolites with bulk water was explored. At physiological temperature and pH, the exchange rate of amine protons in Cr was found to be 7-8 times higher than PCr and ATP. A higher exchange rate in Cr was associated with lower pKa value, suggesting faster dissociation of its amine protons compared to PCr and ATP. CEST MR imaging of these metabolites in vitro in phantoms displayed predominant CEST contrast from Cr and negligible contribution from PCr and ATP with the saturation pulse parameters used in the current study. These results provide a new method to perform high-resolution proton imaging of Cr without contamination from PCr. Potential applications of these finding are discussed. Copyright © 2012 John Wiley & Sons, Ltd.

Laser-induced gas plasma machining

Energy Technology Data Exchange (ETDEWEB)

Elhadj, Selim; Bass, Isaac Louis; Guss, Gabriel Mark; Matthews, Manyalibo J.

2017-10-17

Techniques for removing material from a substrate are provided. A laser beam is focused at a distance from the surface to be treated. A gas is provided at the focus point. The gas is dissociated using the laser energy to generate gas plasma. The substrate is then brought in contact with the gas plasma to enable material removal.

The achievements of the Z-machine; Les exploits de la Z-machine

Energy Technology Data Exchange (ETDEWEB)

Larousserie, D

2008-03-15

The ZR-machine that represents the latest generation of Z-pinch machines has recently begun preliminary testing before its full commissioning in Albuquerque (Usa). During its test the machine has well operated with electrical currents whose intensities of 26 million Ampere are already 2 times as high as the intensity of the operating current of the previous Z-machine. In 2006 the Z-machine reached temperatures of 2 billions Kelvin while 100 million Kelvin would be sufficient to ignite thermonuclear fusion. In fact the concept of Z-pinch machines was imagined in the fifties but the technological breakthrough that has allowed this recent success and the reborn of Z-machine, was the replacement of gas by an array of metal wires through which the electrical current flows and vaporizes it creating an imploding plasma. It is not well understood why Z-pinch machines generate far more radiation than theoretically expected. (A.C.)

Creatine co-ingestion with carbohydrate or cinnamon extract provides no added benefit to anaerobic performance.

Science.gov (United States)

Islam, Hashim; Yorgason, Nick J; Hazell, Tom J

2016-09-01

The insulin response following carbohydrate ingestion enhances creatine transport into muscle. Cinnamon extract is promoted to have insulin-like effects, therefore this study examined if creatine co-ingestion with carbohydrates or cinnamon extract improved anaerobic capacity, muscular strength, and muscular endurance. Active young males (n = 25; 23.7 ± 2.5 y) were stratified into 3 groups: (1) creatine only (CRE); (2) creatine+ 70 g carbohydrate (CHO); or (3) creatine+ 500 mg cinnamon extract (CIN), based on anaerobic capacity (peak power·kg(-1)) and muscular strength at baseline. Three weeks of supplementation consisted of a 5 d loading phase (20 g/d) and a 16 d maintenance phase (5 g/d). Pre- and post-supplementation measures included a 30-s Wingate and a 30-s maximal running test (on a self-propelled treadmill) for anaerobic capacity. Muscular strength was measured as the one-repetition maximum 1-RM for chest, back, quadriceps, hamstrings, and leg press. Additional sets of the number of repetitions performed at 60% 1-RM until fatigue measured muscular endurance. All three groups significantly improved Wingate relative peak power (CRE: 15.4% P = .004; CHO: 14.6% P = .004; CIN: 15.7%, P = .003), and muscular strength for chest (CRE: 6.6% P creatine ingestion lead to similar changes in anaerobic power, strength, and endurance.

Creatine and creatinine contents in different diet types for dogs - effects of source and processing.

Science.gov (United States)

Dobenecker, B; Braun, U

2015-12-01

The concentrations of creatine and its degradation product creatinine were determined in a variety of unprocessed as well as processed feedstuffs suitable for dogs. Unprocessed feedstuffs were categorised as single feedstuffs, bone and raw food diets (BARF), and small vertebrates, for example prey animals. Processed feedstuffs were categorised as meat/meat and bone meals, complete wet diets and complete dry diets. The feedstuffs were chosen to cover a broad range of each of the three defined processed and unprocessed feed categories available on the market without further subclustering. The creatine content of the samples was compared on a dry matter, protein and energy basis. The relation of creatine to crude protein permitted a rating of the meat quality in terms of muscle tissue. We found no difference in creatine concentrations between the three categories of unprocessed feedstuffs (raw single feedstuffs, prey and BARF diets), neither on a dry matter basis nor when expressed relative to crude protein and metabolisable energy respectively. Significantly lower levels were determined in meat/meat and bone meal and commercial dry diets (e.g. 303 mg creatine/MJ ME in unprocessed vs. 6 mg/MJ ME in processed feedstuffs; p creatine which is a natural compound of the diet of this carnivorous and omnivorous species. © 2015 The Authors. Journal of Animal Physiology and Animal Nutrition Published by Blackwell Verlag GmbH.

A comparison of mutagen production in fried ground chicken and beef: effect of supplemental creatine.

Science.gov (United States)

Knize, M G; Shen, N H; Felton, J S

1988-11-01

Ground chicken breast and ground beef with either endogenous or a 10-fold increase in the concentration of creatine were fried at 220 degrees C for 10 min per side. One patty (100 g) of chicken meat yielded 120,000 Salmonella (TA1538) revertants following metabolic activation. The pan residues had 39% of the total activity. Added creatine (10-fold the endogenous level) increased mutagen yields an average of 2-fold. Beef cooked under identical conditions yielded 150,000 revertants/100 g for the meat patties and pan residues combined. Added creatine to beef prior to cooking increased mutagen yields 3-fold. The mutagenic profiles following initial HPLC separation showed that chicken samples with endogenous or added creatine were remarkably similar. Chicken and beef HPLC mutagenicity profiles were also similar to each other, but not identical. This suggests that the general mutagen-forming reactions with the two different types of muscle are qualitatively similar with only minor quantitative differences. The pan residues from both meat types with and without added creatine showed some significant differences in the mutagen peak profile. This work suggests that the types of mutagens formed in chicken are similar to those formed in beef and that creatine appears to be involved in the formation of all the mutagenic compounds produced from fried muscle tissue.

Abnormalities in Human Brain Creatine Metabolism in Gulf War Illness Probed with MRS

Science.gov (United States)

2014-12-01

TYPE Final 3. DATES COVERED 30 Sep 2012 - 29 Sep 2014 4. TITLE AND SUBTITLE 5a. CONTRACT NUMBER Abnormalities in Human Brain Creatine Metabolism in...levels of total creatine (tCr) in veterans with Gulf War Illness have been observed in prior studies. The goal of this research is to estimate amounts and

Effects of Creatine Monohydrate Augmentation on Brain Metabolic and Network Outcome Measures in Women With Major Depressive Disorder.

Science.gov (United States)

Yoon, Sujung; Kim, Jieun E; Hwang, Jaeuk; Kim, Tae-Suk; Kang, Hee Jin; Namgung, Eun; Ban, Soonhyun; Oh, Subin; Yang, Jeongwon; Renshaw, Perry F; Lyoo, In Kyoon

2016-09-15

Creatine monohydrate (creatine) augmentation has the potential to accelerate the clinical responses to and enhance the overall efficacy of selective serotonin reuptake inhibitor treatment in women with major depressive disorder (MDD). Although it has been suggested that creatine augmentation may involve the restoration of brain energy metabolism, the mechanisms underlying its antidepressant efficacy are unknown. In a randomized, double-blind, placebo-controlled trial, 52 women with MDD were assigned to receive either creatine augmentation or placebo augmentation of escitalopram; 34 subjects participated in multimodal neuroimaging assessments at baseline and week 8. Age-matched healthy women (n = 39) were also assessed twice at the same intervals. Metabolic and network outcomes were measured for changes in prefrontal N-acetylaspartate and changes in rich club hub connections of the structural brain network using proton magnetic resonance spectroscopy and diffusion tensor imaging, respectively. We found MDD-related metabolic and network dysfunction at baseline. Improvement in depressive symptoms was greater in patients receiving creatine augmentation relative to placebo augmentation. After 8 weeks of treatment, prefrontal N-acetylaspartate levels increased significantly in the creatine augmentation group compared with the placebo augmentation group. Increment in rich club hub connections was also greater in the creatine augmentation group than in the placebo augmentation group. N-acetylaspartate levels and rich club connections increased after creatine augmentation of selective serotonin reuptake inhibitor treatment. Effects of creatine administration on brain energy metabolism and network organization may partly underlie its efficacy in treating women with MDD. Copyright © 2016 Society of Biological Psychiatry. Published by Elsevier Inc. All rights reserved.

International Society of Sports Nutrition position stand: safety and efficacy of creatine supplementation in exercise, sport, and medicine.

Science.gov (United States)

Kreider, Richard B; Kalman, Douglas S; Antonio, Jose; Ziegenfuss, Tim N; Wildman, Robert; Collins, Rick; Candow, Darren G; Kleiner, Susan M; Almada, Anthony L; Lopez, Hector L

2017-01-01

Creatine is one of the most popular nutritional ergogenic aids for athletes. Studies have consistently shown that creatine supplementation increases intramuscular creatine concentrations which may help explain the observed improvements in high intensity exercise performance leading to greater training adaptations. In addition to athletic and exercise improvement, research has shown that creatine supplementation may enhance post-exercise recovery, injury prevention, thermoregulation, rehabilitation, and concussion and/or spinal cord neuroprotection. Additionally, a number of clinical applications of creatine supplementation have been studied involving neurodegenerative diseases (e.g., muscular dystrophy, Parkinson's, Huntington's disease), diabetes, osteoarthritis, fibromyalgia, aging, brain and heart ischemia, adolescent depression, and pregnancy. These studies provide a large body of evidence that creatine can not only improve exercise performance, but can play a role in preventing and/or reducing the severity of injury, enhancing rehabilitation from injuries, and helping athletes tolerate heavy training loads. Additionally, researchers have identified a number of potentially beneficial clinical uses of creatine supplementation. These studies show that short and long-term supplementation (up to 30 g/day for 5 years) is safe and well-tolerated in healthy individuals and in a number of patient populations ranging from infants to the elderly. Moreover, significant health benefits may be provided by ensuring habitual low dietary creatine ingestion (e.g., 3 g/day) throughout the lifespan. The purpose of this review is to provide an update to the current literature regarding the role and safety of creatine supplementation in exercise, sport, and medicine and to update the position stand of International Society of Sports Nutrition (ISSN).

Cold component flow in a two-component mirror machine

International Nuclear Information System (INIS)

Rognlien, T.D.

1975-12-01

Steady-state solutions are given for the flow characteristics along the magnetic field of the cold plasma component in a two-component mirror machine. The hot plasma component is represented by a fixed density profile. The fluid equations are used to describe the cold plasma, which is assumed to be generated in a localized region at one end of the machine. The ion flow speed, v/sub i/, is required to satisfy the Bohm sheath condition at the end walls, i.e., v/sub i/ greater than or equal to c/sub s/, where c/sub s/ is the ion-acoustic speed. For the case when the cold plasma density, n/sub c/, is much less than the hot plasma density, n/sub h/, the cold plasma is stagnant and does not penetrate through the machine in the zero temperature case. The effect of a finite temperature is to allow for the penetration of a small amount of cold plasma through the machine. For the density range n/sub c/ approximately n/sub h/, the flow solutions are asymmetric about the midplane and have v/sub i/ = c/sub s/ near the midplane. Finally, for n/sub c/ much greater than n/sub h/, the solutions become symmetric about the midplane and approach the Lee--McNamara type solutions with v/sub i/ = c/sub s/ near the mirror throats

Operations analysis of the unscheduled summer machine opening of the Tokamak Fusion Test Reactor (TFTR) at the Princeton Plasma Physics Laboratory

International Nuclear Information System (INIS)

Viola, M.E.; McCann, J.

1985-01-01

During experimental operation, a problem developed with the mechanical integrity of the TFTR surface pumping system neutralizer plates that required a vacuum vessel entry for repairs. This problem, coupled with several less significant machine internal problems that had been developing, forced the decision to make an unscheduled vacuum vessel entry. An extended machine outage at that time would have had a severe impact on the experimental schedule. Therefore, the goal was to make repairs and return the vacuum vessel to a clean condition as quickly as possible. The total time required between the end of regularly scheduled activity and restoration of the machine capability to routinely obtain 1 MA disruption-free plasma was 12 days

Creatine-induced activation of antioxidative defence in myotube cultures revealed by explorative NMR-based metabonomics and proteomics

DEFF Research Database (Denmark)

Young, Jette Feveile; Larsen, Lotte Bach; Malmendal, Anders

2010-01-01

Creatine is a key intermediate in energy metabolism and supplementation of creatine has been used for increasing muscle mass, strength and endurance. Creatine supplementation has also been reported to trigger the skeletal muscle expression of insulin like growth factor I, to increase the fat......-free mass and improve cognition in elderly, and more explorative approaches like transcriptomics has revealed additional information. The aim of the present study was to reveal additional insight into the biochemical effects of creatine supplementation at the protein and metabolite level by integrating...... the explorative techniques, proteomics and NMR metabonomics, in a systems biology approach. METHODS: Differentiated mouse myotube cultures (C2C12) were exposed to 5 mM creatine monohydrate (CMH) for 24 hours. For proteomics studies, lysed myotubes were analyzed in single 2-DGE gels where the first dimension...

Is there a rationale for the use of creatine either as nutritional supplementation or drug administration in humans participating in a sport?

Science.gov (United States)

Benzi, G

2000-03-01

Even though no unambiguous proof for enhanced performance during high-intensity exercise has yet been reported, the creatine administration is charged to improve physical performance and has become a popular practice among subjects participating in different sports. Appropriate creatine dosage may be also used as a medicinal product since, in accordance with the Council Directive 65/65/CEE, any substance which may be administered with a view to restoring, correcting or modifying physiological functions in human beings is considered a medicinal product. Thus, quality, efficacy and safety must characterize the substance. In biochemical terms, creatine administration enhances both creatine and phosphocreatine concentrations, allowing for an increased total creatine pool in skeletal muscle. In thermodynamics terms, creatine interferes with the creatine-creatine kinase-phosphocreatine circuit, which is related to the mitochondrial function as a highly organized system for the energy control of the subcellular adenylate pool. In pharmacokinetics terms, creatine entry into skeletal muscle is initially dependent on the extracellular concentration, but the creatine transport is subsequently down-regulated. In pharmacodynamics terms, the creatine enhances the possibility to maintain power output during brief periods of high-intensity exercises. In spite of uncontrolled daily dosage and long-term administration, no research on creatine safety in humans has been set up by specific standard protocol of clinical pharmacology and toxicology, as currently occurs in phase I for the products for human use. More or less documented side effects induced by creatine are weight gain; influence on insulin production; feedback inhibition of endogenous creatine synthesis; long-term damages on renal function. A major point that related to the quality of creatine products is the amount of creatine ingested in relation to the amount of contaminants present. During the production of creatine

Particle-in-cell plasma simulation codes on the connection machine

International Nuclear Information System (INIS)

Walker, D.W.

1991-01-01

Methods for implementing three-dimensional, electromagnetic, relativistic PIC plasma simulation codes on the Connection Machine (CM-2) are discussed. The gather and scatter phases of the PIC algorithm involve indirect indexing of data, which results in a large amount of communication on the CM-2. Different data decompositions are described that seek to reduce the amount of communication while maintaining good load balance. These methods require the particles to be spatially sorted at the start of each time step, which introduced another form of overhead. The different methods are implemented in CM Fortran on the CM-2 and compared. It was found that the general router is slow in performing the communication in the gather and scatter steps, which precludes an efficient CM Fortran implementation. An alternative method that uses PARIS calls and the NEWS communication network to pipeline data along the axes of the VP set is suggested as a more efficient algorithm

Differences in muscle pain and plasma creatine kinase activity after ...

African Journals Online (AJOL)

encephalopathy,18 and the decrement in muscle power associated with muscle damage.6 ... A high degree of intra-individual variability in plasma. CK activity was ..... 21. Komi PV. Stretch-shortening cycle exercise: a powerful model to study.

Solution thermodynamics of creatine monohydrate in binary (water + ethanol) solvent systems at T = (278.15 to 328.15) K

International Nuclear Information System (INIS)

Song, Liangcheng; Wei, Lihua; Si, Tao; Guo, Huai; Yang, Chunhui

2016-01-01

Highlights: • The solubilities of creatine monohydrate in (ethanol + water) mixtures were investigated. • The solubility data were well correlated by Jouyban–Acree model. • Solution thermodynamic properties were calculated. • The dissolving process of creatine monohydrate in was endothermic and entropy-driven. - Abstract: In order to optimize the crystallization process of creatine monohydrate, the solubility of creatine monohydrate in the binary (water + ethanol) mixture was measured at temperatures ranging from 278.15 K to 328.15 K using the laser monitoring technique. The solubility increased with both the temperature and the mole fraction of water in the solvent mixture. The experimental solubility was well correlated by the Jouyban–Acree model, which generated a sensitive solubility surface for creatine monohydrate. Furthermore, the thermodynamic parameters of this dissolution process were also estimated. The results showed that the dissolution process of creatine monohydrate in each solvent mixture was endothermic and entropy-driven, and that the dissolution of creatine monohydrate became much easier when the mole fraction of water in the solvent mixture increased.

Control processes and machine protection on ASDEX Upgrade

International Nuclear Information System (INIS)

Raupp, G.; Treutterer, W.; Mertens, V.; Neu, G.; Sips, A.; Zasche, D.; Zehetbauer, Th.

2007-01-01

Safe operation of ASDEX Upgrade is guaranteed by a conventional hierarchy of simple and robust hard-wired systems for personnel and machine protection featuring standardized switch-off procedures. Machine protection and handling of off-normal events is further enhanced and peak and lifetime stress minimized through the plasma control system. Based on a real-time process model supporting safety critical applications with data quality tagging, process self-monitoring, watchdog monitoring and alarm propagation, processes detect complex and critical failures and reliably perform case-sensitive counter measures. Intelligent real-time failure handling is done with hardware or software redundancy and performance degradation, or modification of reference values to continue or terminate discharges with reduced machine stress. Examples implemented so far on ASDEX Upgrade are given, such as recovery from measurement failures, switch-over of redundant actuators, handling of actuator limitations, detection of plasma instabilities, plasma state dependent soft landing, or handling of failed switch-off procedures through breakers disconnecting the machine from grid

Design study of a plasma-loaded CRM using TPD-II machine

International Nuclear Information System (INIS)

Minami, Kazuo

2007-08-01

Design study of an experiment for plasma-loaded cyclotron resonance maser (CRM) utilizing TPD-II Machine at NIFS, Japan is described in some detail. The principle of gyrotrons has been believed the CRM instability. However, all the existing linear theories of CRM instability include unphysical modes unstable at infinite values of axial wavenumber that can never be observed experimentally. To overcome the difficulty, we derive and analyze numerically an exact linear dispersion relation of a large orbit electron beam for CRM, and removed the unphysical modes. However, the relation is found to include two principles of cyclotron emission with oscillation frequencies above and below the branch of fast electron cyclotron wave. The former is CRM instability, and the latter is named Chrenkov instability in the azimuthal direction (CIAD). It is noted that the CIAD we found remains only a proposal of a new mechanism for cyclotron emission until the physical existence is verified experimentally. To verify the CIAD, the design study of a plasma-loaded CRM has been carried out. The apparatus consists of two portions installed in the TPD-II: A pair of helical wiggler windings to create a mono-energetic beam with 15 keV and pitch factor V θ /V z ≥1, and microwave circuits including a cylindrical TE 011 mode cavity with resonant frequency 3.45 GHz. For high plasma density n≥1.5x10 11 cm -3 from TPD-II, the CRM instability may be suppressed and the CIAD will take turn. The present experimental study contributes to a deeper understanding and a widened future prospect in gyrotron physics. (author)

Evaluation of Creatine Kinase Activity and Inorganic Phosphate ...

African Journals Online (AJOL)

subjects presenting with major VOC. Keywords: Serum creatine kinase activity, Serum inorganic phosphate concentration, Sickle cell disease,. Steady state, Vaso‑occlusive crisis. Original Article. Address for correspondence: Dr. John C Aneke,. Department of Hematology,. Nnamdi Azikiwe University Teaching. Hospital ...

Serum creatine kinase and lactate dehydrogenase activities in ...

African Journals Online (AJOL)

... in thyroid function are common endocrine disorders affecting 5-10% of individuals over ... Key words: Hyperthyroidism, hypothyroidism, lactate dehydrogenase, serum creatine kinase ... individuals depends on age, race, lean body mass and physical activity. ... measured by radioimmunoassay on AXSYM System (Abbott.

Evaluation of Creatine Kinase Activity and Inorganic Phosphate ...

African Journals Online (AJOL)

Background: Biochemical parameters vary in subjects with different hemoglobin phenotypes, compared with normal controls. Aim: The aim was to evaluate serum creatine kinase (CK) activity and inorganic phosphate concentrations in Nigerian adults with homozygous and heterozygous hemoglobin phenotypes. Subjects ...

The rotational mobility of spin labels in wool creatine depending on temperature, humidity and deformation

International Nuclear Information System (INIS)

Bobodzhanov, P.Kh.; Yusupov, I.Kh.; Marupov, R.

2001-01-01

Present article is devoted to study of rotational mobility of spin labels in wool creatine depending on temperature, humidity and deformation. The experimental data of study of structure and molecular mobility of wool creatine modified by spin labels was considered.

Umbrella sampling of proton transfer in a creatine-water system

Science.gov (United States)

Ivchenko, Olga; Bachert, Peter; Imhof, Petra

2014-04-01

Proton transfer reactions are among the most common processes in chemistry and biology. Proton transfer between creatine and surrounding solvent water is underlying the chemical exchange saturation transfer used as a contrast in magnetic resonance imaging. The free energy barrier, determined by first-principles umbrella sampling simulations (EaDFT 3 kcal/mol) is in the same order of magnitude as the experimentally obtained activation energy. The underlying mechanism is a first proton transfer from the guanidinium group to the water pool, followed by a second transition where a proton is "transferred back" from the nearest water molecule to the deprotonated nitrogen atom of creatine.

Effects of creatine supplementation on cognitive function of healthy individuals: A systematic review of randomized controlled trials.

Science.gov (United States)

Avgerinos, Konstantinos I; Spyrou, Nikolaos; Bougioukas, Konstantinos I; Kapogiannis, Dimitrios

2018-07-15

Creatine is a supplement used by sportsmen to increase athletic performance by improving energy supply to muscle tissues. It is also an essential brain compound and some hypothesize that it aids cognition by improving energy supply and neuroprotection. The aim of this systematic review is to investigate the effects of oral creatine administration on cognitive function in healthy individuals. A search of multiple electronic databases was performed for the identification of randomized clinical trials (RCTs) examining the cognitive effects of oral creatine supplementation in healthy individuals. Six studies (281 individuals) met our inclusion criteria. Generally, there was evidence that short term memory and intelligence/reasoning may be improved by creatine administration. Regarding other cognitive domains, such as long-term memory, spatial memory, memory scanning, attention, executive function, response inhibition, word fluency, reaction time and mental fatigue, the results were conflicting. Performance on cognitive tasks stayed unchanged in young individuals. Vegetarians responded better than meat-eaters in memory tasks but for other cognitive domains no differences were observed. Oral creatine administration may improve short-term memory and intelligence/reasoning of healthy individuals but its effect on other cognitive domains remains unclear. Findings suggest potential benefit for aging and stressed individuals. Since creatine is safe, future studies should include larger sample sizes. It is imperative that creatine should be tested on patients with dementias or cognitive impairment. Copyright © 2018 Elsevier Inc. All rights reserved.

A Pilot Study of Creatine as a Novel Treatment for Depression in Methamphetamine Using Females

Science.gov (United States)

Hellem, Tracy L.; Sung, Young-Hoon; Shi, Xian-Feng; Pett, Marjorie A.; Latendresse, Gwen; Morgan, Jubel; Huber, Rebekah S.; Kuykendall, Danielle; Lundberg, Kelly J.; Renshaw, Perry F.

2015-01-01

Objective Depression among methamphetamine users is more prevalent in females than males, but gender specific treatment options for this comorbidity have not been described. Reduced brain phosphocreatine levels have been shown to be lower in female methamphetamine users compared to males, and, of relevance, studies have demonstrated an association between treatment resistant depression and reduced brain phosphocreatine concentrations. The nutritional supplement creatine monohydrate has been reported to reduce symptoms of depression in female adolescents and adults taking antidepressants, as well as to increase brain phosphocreatine in healthy volunteers. Therefore, the purpose of this pilot study was to investigate creatine monohydrate as a treatment for depression in female methamphetamine users. Methods Fourteen females with depression and comorbid methamphetamine dependence were enrolled in an 8 week open label trial of 5 grams of daily creatine monohydrate and of these 14, eleven females completed the study. Depression was measured using the Hamilton Depression Rating Scale (HAMD) and brain phosphocreatine levels were measured using phosphorus magnetic resonance spectroscopy pre- and post-creatine treatment. Secondary outcome measures included anxiety symptoms, measured with the Beck Anxiety Inventory (BAI), as well as methamphetamine use, monitored by twice weekly urine drug screens and self-reported use. Results The results of a linear mixed effects repeated measures model showed significantly reduced HAMD and BAI scores as early as week 2 when compared to baseline scores. This improvement was maintained through study completion. Brain phosphocreatine concentrations were higher at the second phosphorus magnetic resonance spectroscopy scan compared to the baseline scan; Mbaseline = 0.223 (SD = 0.013) vs. Mpost-treatment = 0.233 (SD = 0.009), t(9) = 2.905, p creatine increased phosphocreatine levels. Also, a reduction in methamphetamine positive urine drug

Dependence of myosin-ATPase on structure bound creatine kinase in cardiac myfibrils from rainbow trout and freshwater turtle

DEFF Research Database (Denmark)

Haagensen, L.; Jensen, D.H.; Gesser, Hans

2008-01-01

The influence of myofibrillar creatine kinase on the myosin-ATPase activity was examined in cardiac ventricular myofibrils isolated from rainbow trout (Oncorhynchus mykiss) and freshwater turtle (Trachemys scripta). The ATPase rate was assessed by recording the rephosphorylation of ADP by the pyr......The influence of myofibrillar creatine kinase on the myosin-ATPase activity was examined in cardiac ventricular myofibrils isolated from rainbow trout (Oncorhynchus mykiss) and freshwater turtle (Trachemys scripta). The ATPase rate was assessed by recording the rephosphorylation of ADP...... by the pyruvate kinase reaction alone or together with the amount of creatine formed, when myofibrillar bound creatine kinase was activated with phosphocreatine. The steady-state concentration of ADP in the solution was varied through the activity of pyruvate kinase added to the solution. For rainbow trout...... myofibrils at a high pyruvate kinase activity, creatine kinase competed for ADP but did not influence the total ATPase activity. When the ADP concentration was elevated within the physiological range by lowering the pyruvate kinase activity, creatine kinase competed efficiently and increased the ATPase...

Creatine Supplementation Associated or Not with Strength Training upon Emotional and Cognitive Measures in Older Women: A Randomized Double-Blind Study

Science.gov (United States)

Alves, Christiano Robles Rodrigues; Merege Filho, Carlos Alberto Abujabra; Benatti, Fabiana Braga; Brucki, Sonia; Pereira, Rosa Maria R.; de Sá Pinto, Ana Lucia; Lima, Fernanda Rodrigues; Roschel, Hamilton; Gualano, Bruno

2013-01-01

Purpose To assess the effects of creatine supplementation, associated or not with strength training, upon emotional and cognitive measures in older woman. Methods This is a 24-week, parallel-group, double-blind, randomized, placebo-controlled trial. The individuals were randomly allocated into one of the following groups (n=14 each): 1) placebo, 2) creatine supplementation, 3) placebo associated with strength training or 4) creatine supplementation associated with strength training. According to their allocation, the participants were given creatine (4 x 5 g/d for 5 days followed by 5 g/d) or placebo (dextrose at the same dosage) and were strength trained or not. Cognitive function, assessed by a comprehensive battery of tests involving memory, selective attention, and inhibitory control, and emotional measures, assessed by the Geriatric Depression Scale, were evaluated at baseline, after 12 and 24 weeks of the intervention. Muscle strength and food intake were evaluated at baseline and after 24 weeks. Results After the 24-week intervention, both training groups (ingesting creatine supplementation and placebo) had significant reductions on the Geriatric Depression Scale scores when compared with the non-trained placebo group (p = 0.001 and p = 0.01, respectively) and the non-trained creatine group (p creatine (p = 0.60) groups, or between the trained placebo and creatine groups (p = 0.83). Both trained groups, irrespective of creatine supplementation, had better muscle strength performance than the non-trained groups. Neither strength training nor creatine supplementation altered any parameter of cognitive performance. Food intake remained unchanged. Conclusion Creatine supplementation did not promote any significant change in cognitive function and emotional parameters in apparently healthy older individuals. In addition, strength training per se improved emotional state and muscle strength, but not cognition, with no additive effects of creatine supplementation

The Effects of Creatine Monohydrate on Permeability of Coronary Artery Endothelium and Level of Blood Lipoprotein in Diabetic Rats.

Science.gov (United States)

Rahmani, Asghar; Asadollahi, Khairollah; Soleimannejad, Kourosh; Khalighi, Zahra; Mohsenzadeh, Yosouf; Hemati, Ruhollah; Moradkhani, Atefeh; Abangah, Ghobad

2016-09-01

Creatine monohydrate has beneficial effects on serum glucose. This study aimed to investigate the effects of creatine on serum biochemical markers and permeability of coronary arteries among diabetic rats. 32 Wistar rats, which weighed 150-200 grams were randomly divided into 4 groups including: group I, control; group II, creatine monohydrate; group III, diabetic rats; and group IV, diabetic rats + creatine. Creatine monohydrate was applied by 400 mg/kg/daily for 5 months. Animals' weights and blood samples were taken before and after the study. Endothelial permeability rate was measured by Evans Blue method. Data were analysed by SPSS 16. At the end of fifth month, rats' weights in diabetic group under treatment with creatine, compared to those without, increased significantly (pcreatine (pcreatine compared to untreated groups, closed to the intact group (pcreatine monohydrate caused an improvement of serum biochemical markers associated with diabetes and reduced the permeability rate of coronary arteries among diabetic rats. © 2016 by the Association of Clinical Scientists, Inc.

Boehringer immunoinhibition procedure for creatine kinase-MB evaluated and compared with column ion-exchange chromatography

NARCIS (Netherlands)

ter Welle, H. F.; Baartscheer, T.; Fiolet, J. W.

1983-01-01

In determination of creatine kinase isoenzyme MB (CK-MB), the Boehringer immunoinhibition method gives a high and variable blank activity as compared with column-chromatography. Thus a correction must be applied. Furthermore, a second correction of 1% of total creatine kinase activity is necessary

The acute effect of beta-guanidinopropionic acid versus creatine or placebo in healthy men (ABC-Trial): A randomized controlled first-in-human trial.

Science.gov (United States)

Karamat, Fares A; Horjus, Deborah L; Haan, Yentl C; van der Woude, Lisa; Schaap, Marianne C; Oudman, Inge; van Montfrans, Gert A; Nieuwland, Rienk; Salomons, Gajja S; Clark, Joseph F; Brewster, Lizzy M

2017-12-01

Increasing evidence indicates that the ATP-generating enzyme creatine kinase (CK) is involved in hypertension. CK rapidly regenerates ATP from creatine phosphate and ADP. Recently, it has been shown that beta-guanidinopropionic acid (GPA), a kidney-synthesized creatine analogue and competitive CK inhibitor, reduced blood pressure in spontaneously hypertensive rats. To further develop the substance as a potential blood pressure-lowering agent, we assessed the tolerability of a sub-therapeutic GPA dose in healthy men. In this active and placebo-controlled, triple-blind, single-centre trial, we recruited 24 healthy men (18-50 years old, BMI 18.5-29.9 kg m -2 ) in the Netherlands. Participants were randomized (1:1:1) to one week daily oral administration of GPA 100 mg, creatine 5 g, or matching placebo. The primary outcome was the tolerability of GPA, in an intent-to-treat analysis. Twenty-four randomized participants received the allocated intervention and 23 completed the study. One participant in the placebo arm dropped out for personal reasons. GPA was well tolerated, without serious or severe adverse events. No abnormalities were reported with GPA use in clinical safety parameters, including physical examination, laboratory studies, or 12-Lead ECG. At day 8, mean plasma GPA was 213.88 (SE 0.07) in the GPA arm vs. 32.75 (0.00) nmol l -1 in the placebo arm, a mean difference of 181.13 (95% CI 26.53-335.72). In this first-in-human trial, low-dose GPA was safe and well-tolerated when used during 1 week in healthy men. Subsequent studies should focus on human pharmacokinetic and pharmacodynamic assessments with different doses. © 2017 The Authors. British Journal of Clinical Pharmacology published by John Wiley & Sons Ltd on behalf of British Pharmacological Society.

Three-step preparation and purification of phosphorus-33-labeled creatine phosphate of high specific activity

International Nuclear Information System (INIS)

Savabi, F.; Geiger, P.J.; Bessman, S.P.

1984-01-01

Rabbit heart mitochondria were used as a source of enzymes for the synthesis of phosphorus-labeled creatine phosphate. This method is based on the coupled reaction between mitochondrial oxidative phosphorylation and mitochondrial-bound creatine kinase. It is possible to convert more than 90% of the inorganic phosphate (P/sub i/) to creatine phosphate. The method used only small amounts of adenine nucleotides which led to a product with only slight nucleotide contamination. This could be removed by activated charcoal extraction. For further purification, a method for the removal of residual P/sub i/ is described. 20 references

The Role of Supplemented Creatine in Human Metabolism

Czech Academy of Sciences Publication Activity Database

Petr, M.; Navrátil, Tomáš; Heyrovský, Michael; Kohlíková, E.

2011-01-01

Roč. 15, č. 17 (2011), s. 3029-3042 ISSN 1385-2728 R&D Projects: GA AV ČR IAA400400806 Institutional research plan: CEZ:AV0Z40400503 Keywords : creatine * creatinine * folates Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 3.064, year: 2011

NMR studies on 15N-labeled creatine (CR), creatinine (CRN), phosphocreatine (PCR), and phosphocreatinine (PCRN), and on barriers to rotation in creatine kinase-bound creatine in the enzymatic reaction

International Nuclear Information System (INIS)

Kenyon, G.L.; Reddick, R.E.

1986-01-01

Recently, the authors have synthesized 15 N-2-Cr, 15 N-3-Crn, 15 N-2-Crn, 15 N-3-PCrn, 15 N-3-PCr, and 15 N-2-PCr. 1 H, 15 N, 31 P NMR data show that Crn protonates exclusively at the non-methylated ring nitrogen, confirm that PCrn is phosphorylated at the exocyclic nitrogen, and demonstrate that the 31 P- 15 N one-bond coupling constant in 15 N-3-PCr is 18 Hz, not 3 Hz as previously reported by Brindle, K.M., Porteous, R. and Radda, G.K.. The authors have found that creatine kinase is capable of catalyzing the 14 N/ 15 N positional isotope exchange of 3- 15 N-PCr in the presence of MgADP, but not in its absence. Further, the exchange does not take place when labeled PCr is resynthesized exclusively from the ternary complex E X Cr X MgATP as opposed to either E X Cr or free Cr. This suggests that the enzyme both imparts an additional rotational barrier to creatine in the complex and catalyzes the transfer of phosphoryl group with essentially complete regiospecificity

Changes of creatine kinase structure upon ligand binding as seen by small-angle scattering

Science.gov (United States)

Forstner, Michael; Kriechbaum, Manfred; Laggner, Peter; Wallimann, Theo

1996-09-01

Small-angle X-ray and neutron scattering have been used to investigate structural changes upon binding of individual substrates or a transition state analogue complex (TSAC), consisting of Mg-ADP, creatine and KNO 3 to creatine kinase isoenzymes (dimeric M-CK and octameric Mi-CK) and monomeric arginine kinase (AK). Considerable changes in the shape and the size of the molecules occurred upon binding of Mg-ATP and TSAC, whereas creatine alone had only a small effect. In Mi-CK, the radius of gyration was reduced from 55.6 Å (free enzyme) to 48.9 Å (enzyme + Mg-ATP) and to 48.2 Å (enzyme + TSAC). The experiments performed with M-CK showed similar changes from 28.0 Å (free enzyme) to 25.6 Å (enzyme + Mg-ATP) and to 25.5 Å (enzyme + TSAC). Creatine alone did not lead to significant changes in the radii of gyration, nor did free ATP or ADP. AK showed the same behaviour: a change of the radius of gyration from 21.5 Å (free enzyme) to 19.7 Å (enzyme + MG-ATP), whereas with arginine alone only a minor change could be observed. The primary change in structure as seen with monomeric AK seems to be a magnesium-nucleotide induced domain movement relative to each other, whereas the effect of substrate may be of local order only. In creatine kinase, however, further movements must be involved in the large conformational change.

Creatine Loading, Resistance Exercise Performance, and Muscle Mechanics.

Science.gov (United States)

Stevenson, Scott W.; Dudley, Gary A.

2001-01-01

Examined whether creatine (CR) monohydrate loading would alter resistance exercise performance, isometric strength, or in vivo contractile properties of the quadriceps femoris muscle compared with placebo loading in resistance-trained athletes. Overall, CR loading did not provide an ergogenic benefit for the unilateral dynamic knee extension…

Acute and chronic safety and efficacy of dose dependent creatine nitrate supplementation and exercise performance.

Science.gov (United States)

Galvan, Elfego; Walker, Dillon K; Simbo, Sunday Y; Dalton, Ryan; Levers, Kyle; O'Connor, Abigail; Goodenough, Chelsea; Barringer, Nicholas D; Greenwood, Mike; Rasmussen, Christopher; Smith, Stephen B; Riechman, Steven E; Fluckey, James D; Murano, Peter S; Earnest, Conrad P; Kreider, Richard B

2016-01-01

Creatine monohydrate (CrM) and nitrate are popular supplements for improving exercise performance; yet have not been investigated in combination. We performed two studies to determine the safety and exercise performance-characteristics of creatine nitrate (CrN) supplementation. Study 1 participants (N = 13) ingested 1.5 g CrN (CrN-Low), 3 g CrN (CrN-High), 5 g CrM or a placebo in a randomized, crossover study (7d washout) to determine supplement safety (hepatorenal and muscle enzymes, heart rate, blood pressure and side effects) measured at time-0 (unsupplemented), 30-min, and then hourly for 5-h post-ingestion. Study 2 participants (N = 48) received the same CrN treatments vs. 3 g CrM in a randomized, double-blind, 28d trial inclusive of a 7-d interim testing period and loading sequence (4 servings/d). Day-7 and d-28 measured Tendo™ bench press performance, Wingate testing and a 6x6-s bicycle ergometer sprint. Data were analyzed using a GLM and results are reported as mean ± SD or mean change ± 95 % CI. In both studies we observed several significant, yet stochastic changes in blood markers that were not indicative of potential harm or consistent for any treatment group. Equally, all treatment groups reported a similar number of minimal side effects. In Study 2, there was a significant increase in plasma nitrates for both CrN groups by d-7, subsequently abating by d-28. Muscle creatine increased significantly by d-7 in the CrM and CrN-High groups, but then decreased by d-28 for CrN-High. By d-28, there were significant increases in bench press lifting volume (kg) for all groups (PLA, 126.6, 95 % CI 26.3, 226.8; CrM, 194.1, 95 % CI 89.0, 299.2; CrN-Low, 118.3, 95 % CI 26.1, 210.5; CrN-High, 267.2, 95 % CI 175.0, 359.4, kg). Only the CrN-High group was significantly greater than PLA (p power (PLA, 59.0, 95 % CI 4.5, 113.4; CrM, 68.6, 95 % CI 11.4, 125.8; CrN-Low, 40.9, 95 % CI -9.2, 91.0; CrN-High, 60.9, 95 % CI 10.8, 111.1, W) and

Efficacy and safety of creatine supplementation in juvenile dermatomyositis: A randomized, double-blind, placebo-controlled crossover trial.

Science.gov (United States)

Solis, Marina Yazigi; Hayashi, Ana Paula; Artioli, Guilherme Giannini; Roschel, Hamilton; Sapienza, Marcelo Tatit; Otaduy, Maria Concepción; De Sã Pinto, Ana Lucia; Silva, Clovis Artur; Sallum, Adriana Maluf Elias; Pereira, Rosa Maria R; Gualano, Bruno

2016-01-01

It has been suggested that creatine supplementation is safe and effective for treating idiopathic inflammatory myopathies, but no pediatric study has been conducted to date. The objective of this study was to examine the efficacy and safety of creatine supplementation in juvenile dermatomyositis (JDM) patients. In this study, JDM patients received placebo or creatine supplementation (0.1 g/kg/day) in a randomized, crossover, double-blind design. Subjects were assessed at baseline and after 12 weeks. The primary outcome was muscle function. Secondary outcomes included body composition, aerobic conditioning, health-related quality of life, and muscle phosphocreatine (PCr) content. Safety was assessed by laboratory parameters and kidney function measurements. Creatine supplementation did not affect muscle function, intramuscular PCr content, or any other secondary outcome. Kidney function was not affected, and no side effects were reported. Twelve weeks of creatine supplementation in JDM patients were well-tolerated and free of adverse effects, but treatment did not affect muscle function, intramuscular PCr, or any other parameter. © 2015 Wiley Periodicals, Inc.

Effects of Creatine Supplementation on Muscle Strength and Optimal Individual Post-Activation Potentiation Time of the Upper Body in Canoeists.

Science.gov (United States)

Wang, Chia-Chi; Lin, Shu-Cheng; Hsu, Shu-Ching; Yang, Ming-Ta; Chan, Kuei-Hui

2017-10-27

Creatine supplementation reduces the impact of muscle fatigue on post-activation potentiation (PAP) of the lower body, but its effects on the upper body remain unknown. This study examined the effects of creatine supplementation on muscle strength, explosive power, and optimal individual PAP time of the upper body during a set of complex training bouts in canoeists. Seventeen male high school canoeists performed a bench row for one repetition at maximum strength and conducted complex training bouts to determine the optimal individual timing of PAP and distance of overhead medicine ball throw before and after the supplementation. Subjects were assigned to a creatine or placebo group, and later consumed 20 g of creatine or carboxymethyl cellulose per day for six days. After supplementation, the maximal strength in the creatine group significantly increased ( p creatine group was significantly earlier than the pre-supplementation times ( p creatine supplementation increases maximal strength and shortens the optimal individual PAP time of the upper body in high school athletes, but has no effect on explosive power. Moreover, it was found that the recovery time between a bench row and an overhead medicine ball throw in a complex training bout is an individual phenomenon.

Increased understanding of the dynamics and transport in ITB plasmas from multi- machine comparisons

International Nuclear Information System (INIS)

Gohil, P.

2002-01-01

This paper presents details on: (a) examination and compilation of experimental results on transport from the many machines worldwide to better understand the physics of ITB formation and sustainment; (b) the development of an international database on ITB experimental results to determine the requirements for the formation and sustainment of ITBs, especially for reactor relevant conditions; (c) determining and performing comprehensive tests of theory-based models and simulations using the experimental ITB database. This paper will further present the status of research on critical issues in ITB physics including barrier formation and access conditions, particle and impurity transport, fueling, core-edge integration, profile control and stability as well as issues of accessibility in reactor scale devices such as barriers with T e =T i , barriers with low toroidal rotation and flat density profiles. Results will be presented from many devices providing a clearer understanding of transport and ITB physics in present plasmas and how this understanding can be applied to increase the performance of plasmas in future devices. An ITB database is being developed. (author)

Plasma Diagnostics

Energy Technology Data Exchange (ETDEWEB)

Zaveryaev, V [Kurchatov Institute, Moscow (Russian Federation); others, and

2012-09-15

The success in achieving peaceful fusion power depends on the ability to control a high temperature plasma, which is an object with unique properties, possibly the most complicated object created by humans. Over years of fusion research a new branch of science has been created, namely plasma diagnostics, which involves knowledge of almost all fields of physics, from electromagnetism to nuclear physics, and up-to-date progress in engineering and technology (materials, electronics, mathematical methods of data treatment). Historically, work on controlled fusion started with pulsed systems and accordingly the methods of plasma parameter measurement were first developed for short lived and dense plasmas. Magnetically confined hot plasmas require the creation of special experimental techniques for diagnostics. The diagnostic set is the most scientifically intensive part of a plasma device. During many years of research operation some scientific tasks have been solved while new ones arose. New tasks often require significant changes in the diagnostic system, which is thus a very flexible part of plasma machines. Diagnostic systems are designed to solve several tasks. As an example here are the diagnostic tasks for the International Thermonuclear Experimental Reactor - ITER: (1) Measurements for machine protection and basic control; (2) Measurements for advanced control; (3) Additional measurements for performance evaluation and physics. Every new plasma machine is a further step along the path to the main goal - controlled fusion - and nobody knows in advance what new phenomena will be met on the way. So in the planning of diagnostic construction we should keep in mind further system upgrading to meet possible new scientific and technical challenges. (author)

Erythrocyte creatine as a marker of intravascular hemolysis due to left ventricular outflow tract obstruction in hypertrophic cardiomyopathy.

Science.gov (United States)

Kubo, Toru; Okumiya, Toshika; Baba, Yuichi; Hirota, Takayoshi; Tanioka, Katsutoshi; Yamasaki, Naohito; Sugiura, Tetsuro; Doi, Yoshinori L; Kitaoka, Hiroaki

2016-03-01

Erythrocyte creatine, a marker of erythrocyte age that increases with shortening of erythrocyte survival, has been reported to be a quantitative and reliable marker for intravascular hemolysis. We hypothesized that hemolysis could also occur due to intraventricular obstruction in patients with hypertrophic cardiomyopathy (HCM). The purpose of this study was to examine the presence of subclinical hemolysis and the relation between intravascular hemolysis and intraventricular pressure gradient (IVPG). We measured erythrocyte creatine in 92 HCM patients. Twelve patients had left ventricular outflow tract obstruction (LVOTO), 4 had midventricular obstruction (MVO), and the remaining 76 were non-obstructive. Erythrocyte creatine levels ranged from 0.92 to 4.36μmol/g hemoglobin. Higher levels of erythrocyte creatine were associated with higher IVPG (r=0.437, pcreatine levels are high (≥1.8μmol/g hemoglobin), subclinical hemolysis is considered to be present. Half of LVOTO patients and no MVO patients showed high erythrocyte creatine levels. Although non-obstructive patients did not show significant intraventricular obstruction at rest, some showed high erythrocyte creatine levels. When LVOT-PG was measured during the strain phase of the Valsalva maneuver in 20 non-obstructive patients, 7 of those 20 patients showed LVOTO. In the 20 patients, there was no relation between erythrocyte creatine levels and LVOT-PG before the Valsalva maneuver (r=0.125, p=0.600), whereas there was a significant correlation between erythrocyte creatine and LVOT-PG provoked by the Valsalva maneuver (r=0.695, p=0.001). There is biochemical evidence of subclinical hemolysis in patients with HCM, and this hemolysis seems to be associated with LVOTO provoked by daily physical activities. Copyright © 2015 Japanese College of Cardiology. Published by Elsevier Ltd. All rights reserved.

Serum creatine kinase and lactate dehydrogenase activities in ...

African Journals Online (AJOL)

Background and Objectives: There is the recognition of a pattern of elevations of serum enzymes in hyperthyroid and hypothyroid patients. The aims of this study were to determine the activities of serum creatine kinase (CK) and lactate deydrogenase (LDH) in thyroid disorders, and to evaluate the relationship between CK, ...

Conceptual studies of plasma engineering test facility

International Nuclear Information System (INIS)

Hiraoka, Toru; Tazima, Teruhiko; Sugihara, Masayoshi; Kasai, Masao; Shinya, Kichiro

1979-04-01

Conceptual studies have been made of a Plasma Engineering Test Facility, which is to be constructed following JT-60 prior to the experimental power reactor. The physical aim of this machine is to examine self-ignition conditions. This machine possesses all essential technologies for reactor plasma, i.e. superconducting magnet, remote maintenance, shielding, blanket test modules, tritium handling. Emphasis in the conceptual studies was on structural consistency of the machine and whether the machine would be constructed practically. (author)

Protective effects of regular aerobic exercise on renal tissue injury following creatine monohydrate supplementation in rats

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Davoud Rahimi

2017-01-01

Full Text Available Creatine is one of the most common supplements for improvement of athletic performance which is used by athletes. The most important debate about creatine consumption is its adverse effect on kidneys due to increased protein load. This study was performed to evaluate the protective effects of aerobic exercise on renal tissue injury following consumption of creatine monohydrate in the rat. For this purpose, 30 male Wistar rats were randomly divided into 3 groups of 10 animals each. Group 1, as control, received only standard food. Group 2 received 5 g/kg b.w. creatine monohydrate supplement daily for 8 weeks through gavage and group 3 received creatine monohydrate supplementation in the same manner30 minutes before aerobic exercise. Aerobic exercise was performed 5 times per week on treadmill at speed of 10-25m/min for 10-30 minutes with the slope of 5 degrees. At the end of 8 weeks, water intake and urinary excretion of rats were measured and blood samples were collected for measurement of serum renal function biomarkers including urea, uric acid and creatinine. Finally, the rats were euthanized for renal histopathology. In group 3, by doing regular aerobic exercise, water intake and urinary excretion rates were significantly (p

Project of experimental study on plasma waves and plasma turbulence

International Nuclear Information System (INIS)

Ferreira, J.L.

1990-09-01

The objective of this project is to perform experiments with wave phenomena on plasmas. Particular attention will be given to Langmuir and whistler waves due to its relations with several phenomena occuring on space and laboratory plasmas. The new concepts of particle acceleration with electromagnetic waves, the auroral phenomena on the polar regions and the charged particle precipitation to the atmosphere through anomalies of the earth magnetic field are examples where these waves have an important role. In this project we intend to study the propagation of these waves in a quiescent plasma machine. This machine is able to produce a plasma with density and temperature with values similar to what is met in the ionosphere. This project will be a part of the activities of the basic plasma group of the INPE's Associated Plasma Laboratory (LAP). It will have the collaboration of the departments of Aeronomy and Geophysics also from INPE, and the collaboration of the Plasma and Gas Physics Laboratory from University of Paris - South, in France. (author)

Effects of whole-body x irradiation on the biogenesis of creatine in the rat

International Nuclear Information System (INIS)

Thyagarajan, P.; Vakil, U.K.; Sreenivasan, A.

1977-01-01

Influences of whole-body x irradiation on various aspects of creatine metabolism have been studied. Exposures to sublethal or lethal doses of x radiation results in excessive urinary excretion as well as higher accumulation of creatine in the skeletal muscle of x-irradiated rats. A sudden fall in CPK activity in muscle with a concomitant rise in serum suggests that changes in serum and tissue CPK activity are of an adaptive nature in rats exposed to sublethal doses of x radiation. In vitro studies on creatine synthesis shows that transaminidase and methyl transferase activities in kidneys and liver, respectively, are decreased on the 5th day in the x-irradiated, are decreased on the 5th day in the x-irradiated rat. However, on the 8th day, the enzyme activities are restored to normal

Incubating Isolated Mouse EDL Muscles with Creatine Improves Force Production and Twitch Kinetics in Fatigue Due to Reduction in Ionic Strength

Science.gov (United States)

Head, Stewart I.; Greenaway, Bronwen; Chan, Stephen

2011-01-01

Background Creatine supplementation can improve performance during high intensity exercise in humans and improve muscle strength in certain myopathies. In this present study, we investigated the direct effects of acute creatine incubation on isolated mouse fast-twitch EDL muscles, and examined how these effects change with fatigue. Methods and Results The extensor digitorum longus muscle from mice aged 12–14 weeks was isolated and stimulated with field electrodes to measure force characteristics in 3 different states: (i) before fatigue; (ii) immediately after a fatigue protocol; and (iii) after recovery. These served as the control measurements for the muscle. The muscle was then incubated in a creatine solution and washed. The measurement of force characteristics in the 3 different states was then repeated. In un-fatigued muscle, creatine incubation increased the maximal tetanic force. In fatigued muscle, creatine treatment increased the force produced at all frequencies of stimulation. Incubation also increased the rate of twitch relaxation and twitch contraction in fatigued muscle. During repetitive fatiguing stimulation, creatine-treated muscles took 55.1±9.5% longer than control muscles to lose half of their original force. Measurement of weight changes showed that creatine incubation increased EDL muscle mass by 7%. Conclusion Acute creatine application improves force production in isolated fast-twitch EDL muscle, and these improvements are particularly apparent when the muscle is fatigued. One likely mechanism for this improvement is an increase in Ca2+ sensitivity of contractile proteins as a result of ionic strength decreases following creatine incubation. PMID:21850234

Incubating isolated mouse EDL muscles with creatine improves force production and twitch kinetics in fatigue due to reduction in ionic strength.

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Stewart I Head

Full Text Available BACKGROUND: Creatine supplementation can improve performance during high intensity exercise in humans and improve muscle strength in certain myopathies. In this present study, we investigated the direct effects of acute creatine incubation on isolated mouse fast-twitch EDL muscles, and examined how these effects change with fatigue. METHODS AND RESULTS: The extensor digitorum longus muscle from mice aged 12-14 weeks was isolated and stimulated with field electrodes to measure force characteristics in 3 different states: (i before fatigue; (ii immediately after a fatigue protocol; and (iii after recovery. These served as the control measurements for the muscle. The muscle was then incubated in a creatine solution and washed. The measurement of force characteristics in the 3 different states was then repeated. In un-fatigued muscle, creatine incubation increased the maximal tetanic force. In fatigued muscle, creatine treatment increased the force produced at all frequencies of stimulation. Incubation also increased the rate of twitch relaxation and twitch contraction in fatigued muscle. During repetitive fatiguing stimulation, creatine-treated muscles took 55.1±9.5% longer than control muscles to lose half of their original force. Measurement of weight changes showed that creatine incubation increased EDL muscle mass by 7%. CONCLUSION: Acute creatine application improves force production in isolated fast-twitch EDL muscle, and these improvements are particularly apparent when the muscle is fatigued. One likely mechanism for this improvement is an increase in Ca(2+ sensitivity of contractile proteins as a result of ionic strength decreases following creatine incubation.

Changes of lipidemia after one month of creatine supplementation

Czech Academy of Sciences Publication Activity Database

Navrátil, Tomáš; Petr, M.; Kohlíková, E.

2015-01-01

Roč. 146, č. 5 (2015), s. 771-780 ISSN 0026-9247 R&D Projects: GA ČR(CZ) GAP208/12/1645 Institutional support: RVO:61388955 Keywords : creatine * vitamin B12 * folates Subject RIV: CG - Electrochemistry Impact factor: 1.131, year: 2015

Rhabdomyolysis-Associated Acute Kidney Injury With Normal Creatine Phosphokinase.

Science.gov (United States)

Kamal, Faisal; Snook, Lindsay; Saikumar, Jagannath H

2018-01-01

Rhabdomyolysis is a syndrome characterized by the breakdown of skeletal muscle and leakage of intracellular myocyte contents, such as creatine phosphokinase (CPK) and myoglobin, into the interstitial space and plasma resulting in acute kidney injury (AKI). Elevated CPK of at least 5 times the upper limit of normal is an important diagnostic marker of Rhabdomyolysis. We present a case of rhabdomyolysis with severe AKI with a normal CPK at presentation. A 32-year-old man presented with acute respiratory failure and AKI after an overdose of recreational drugs. Urinalysis at presentation showed trace amounts of blood, identified as rare red blood cells under microscopy. CPK was 156 U/L at presentation. Workup for glomerulonephritis and vasculitis was negative. He was initiated on renal replacement therapy, and a kidney biopsy showed severe acute tubular injury with positive myoglobin casts. Supportive management and renal replacement therapy was provided, and renal function spontaneously improved after a few weeks. This is an uncommon clinical presentation of severe rhabdomyolysis complicated by AKI. This suggests that CPK alone may not be a sensitive marker for rhabdomyolysis-induced AKI in some cases. Copyright © 2018 Southern Society for Clinical Investigation. Published by Elsevier Inc. All rights reserved.

The effect of combined supplementation of carbohydrates and creatine on anaerobic performance

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AS Theodorou

2017-02-01

Full Text Available The purpose of the study was to examine the effect of creatine (Cr supplementation on anaerobic performance when ingesting creatine and carbohydrates (CHO together. Twenty male physical education students comprised the two experimental (CR and CRCHO and one control (CON groups of the study. All groups performed three 30 s anaerobic Wingate tests (AWTs interspersed with 6 minutes of recovery. The CR group (n = 7 ingested 5 g of Cr 5 times per day for 4 days. Subjects in the CRCHO group (n = 6 ingested the same quantity but additionally after each 5 g dose of Cr consumed 500 ml of a commercially available energy drink containing 100 g of simple sugars. Over all three AWTs average mean power improved significantly compared to baseline for the CR group (5.51% but not for the CRCHO group (3.06%. Mean power for the second AWT was improved following the acute loading for the CR group only (4.54% and for the third AWT for both CR (8.49% and CRCHO (5.75% groups. Over all three AWTs a significant change was recorded in average peak power following the acute loading for the CR group (8.26% but not for the CRCHO group (4.11%. Peak power was significantly improved following the loading only for the CR group during the third AWT (19.79%. No changes in AWT performance were recorded for the CON group after intervention. The findings of the present study suggest that ingesting creatine together with carbohydrates will not further improve performance compared to the ingestion of creatine only.

Mirror fusion test facility plasma diagnostics system

International Nuclear Information System (INIS)

Thomas, S.R. Jr.; Coffield, F.E.; Davis, G.E.; Felker, B.

1979-01-01

During the past 25 years, experiments with several magnetic mirror machines were performed as part of the Magnetic Fusion Energy (MFE) Program at LLL. The latest MFE experiment, the Mirror Fusion Test Facility (MFTF), builds on the advances of earlier machines in initiating, stabilizing, heating, and sustaining plasmas formed with deuterium. The goals of this machine are to increase ion and electron temperatures and show a corresponding increase in containment time, to test theoretical scaling laws of plasma instabilities with increased physical dimensions, and to sustain high-beta plasmas for times that are long compared to the energy containment time. This paper describes the diagnostic system being developed to characterize these plasma parameters

Variability of Creatine Metabolism Genes in Children with Autism Spectrum Disorder

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Jessie M. Cameron

2017-07-01

Full Text Available 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. The objective of the study was to test the hypothesis that genetic variability in creatine metabolism genes is associated with autism. We sequenced GATM, GAMT and SLC6A8 genes in 166 patients with autism (coding sequence, introns and adjacent untranslated regions. A total of 29, 16 and 25 variants were identified in each gene, respectively. Four variants were novel in GATM, and 5 in SLC6A8 (not present in the 1000 Genomes, Exome Sequencing Project (ESP or Exome Aggregation Consortium (ExAC databases. A single variant in each gene was identified as non-synonymous, and computationally predicted to be potentially damaging. Nine variants in GATM were shown to have a lower minor allele frequency (MAF in the autism population than in the 1000 Genomes database, specifically in the East Asian population (Fisher’s exact test. Two variants also had lower MAFs in the European population. In summary, there were no apparent associations of variants in GAMT and SLC6A8 genes with autism. The data implying there could be a lower association of some specific GATM gene variants with autism is an observation that would need to be corroborated in a larger group of autism patients, and with sub-populations of Asian ethnicities. Overall, our findings suggest that the genetic variability of creatine synthesis/transport is unlikely to play a part in the pathogenesis of autism

Variability of Creatine Metabolism Genes in Children with Autism Spectrum Disorder.

Science.gov (United States)

Cameron, Jessie M; Levandovskiy, Valeriy; Roberts, Wendy; Anagnostou, Evdokia; Scherer, Stephen; Loh, Alvin; Schulze, Andreas

2017-07-31

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. The objective of the study was to test the hypothesis that genetic variability in creatine metabolism genes is associated with autism. We sequenced GATM , GAMT and SLC6A8 genes in 166 patients with autism (coding sequence, introns and adjacent untranslated regions). A total of 29, 16 and 25 variants were identified in each gene, respectively. Four variants were novel in GATM , and 5 in SLC6A8 (not present in the 1000 Genomes, Exome Sequencing Project (ESP) or Exome Aggregation Consortium (ExAC) databases). A single variant in each gene was identified as non-synonymous, and computationally predicted to be potentially damaging. Nine variants in GATM were shown to have a lower minor allele frequency (MAF) in the autism population than in the 1000 Genomes database, specifically in the East Asian population (Fisher's exact test). Two variants also had lower MAFs in the European population. In summary, there were no apparent associations of variants in GAMT and SLC6A8 genes with autism. The data implying there could be a lower association of some specific GATM gene variants with autism is an observation that would need to be corroborated in a larger group of autism patients, and with sub-populations of Asian ethnicities. Overall, our findings suggest that the genetic variability of creatine synthesis/transport is unlikely to play a part in the pathogenesis of autism spectrum

Periodontal status and serum creatine kinase levels among young ...

African Journals Online (AJOL)

Objectives: It is hypothesized that soccer players with periodontal disease exhibit raised serum creatine kinase (CK) levels as compared to those without periodontal disease. We assessed the clinical gingival status and serum CK levels among young soccer players. Materials and Methods: Demographic data were ...

Comparative quantification of dietary supplemented neural creatine concentrations with (1)H-MRS peak fitting and basis spectrum methods.

Science.gov (United States)

Turner, Clare E; Russell, Bruce R; Gant, Nicholas

2015-11-01

Magnetic resonance spectroscopy (MRS) is an analytical procedure that can be used to non-invasively measure the concentration of a range of neural metabolites. Creatine is an important neurometabolite with dietary supplementation offering therapeutic potential for neurological disorders with dysfunctional energetic processes. Neural creatine concentrations can be probed using proton MRS and quantified using a range of software packages based on different analytical methods. This experiment examines the differences in quantification performance of two commonly used analysis packages following a creatine supplementation strategy with potential therapeutic application. Human participants followed a seven day dietary supplementation regime in a placebo-controlled, cross-over design interspersed with a five week wash-out period. Spectroscopy data were acquired the day immediately following supplementation and analyzed with two commonly-used software packages which employ vastly different quantification methods. Results demonstrate that neural creatine concentration was augmented following creatine supplementation when analyzed using the peak fitting method of quantification (105.9%±10.1). In contrast, no change in neural creatine levels were detected with supplementation when analysis was conducted using the basis spectrum method of quantification (102.6%±8.6). Results suggest that software packages that employ the peak fitting procedure for spectral quantification are possibly more sensitive to subtle changes in neural creatine concentrations. The relative simplicity of the spectroscopy sequence and the data analysis procedure suggest that peak fitting procedures may be the most effective means of metabolite quantification when detection of subtle alterations in neural metabolites is necessary. The straightforward technique can be used on a clinical magnetic resonance imaging system. Copyright © 2015 Elsevier Inc. All rights reserved.

The plasma physics of plasma processing

International Nuclear Information System (INIS)

Shohet, L.

1991-01-01

Plasma processing is used for producing new materials with unusual and superior properties, for developing new chemical compounds and processes, for machining, and for altering and refining materials and surfaces. It has direct applications to semiconductor fabrication, materials synthesis, welding, lighting, polymers, anti-corrosion coatings, machine tools, metallurgy, electrical and electronics devices, hazardous waste removal, high performance ceramics, and many other items in both high-technology and the more traditional industries. Plasma processing takes on a wide variety of apparently different forms in industry, but the techniques share many common characteristics and problems. Control of the generation and flux of ions, electrons and free radicals in the plasma and their incidence on a surface is vital. Diagnostics, sensors, modeling techniques, and associated statistical methods are needed. However, without an in-depth understanding of the variety of phenomena taking place and their application to the industrial environment, advances in this technology, and its efficient use, will occur at a diminishing rate

Effects of Creatine Supplementation on Muscle Strength and Optimal Individual Post-Activation Potentiation Time of the Upper Body in Canoeists

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Chia-Chi Wang

2017-10-01

Full Text Available Creatine supplementation reduces the impact of muscle fatigue on post-activation potentiation (PAP of the lower body, but its effects on the upper body remain unknown. This study examined the effects of creatine supplementation on muscle strength, explosive power, and optimal individual PAP time of the upper body during a set of complex training bouts in canoeists. Seventeen male high school canoeists performed a bench row for one repetition at maximum strength and conducted complex training bouts to determine the optimal individual timing of PAP and distance of overhead medicine ball throw before and after the supplementation. Subjects were assigned to a creatine or placebo group, and later consumed 20 g of creatine or carboxymethyl cellulose per day for six days. After supplementation, the maximal strength in the creatine group significantly increased (p < 0.05. The optimal individual PAP time in the creatine group was significantly earlier than the pre-supplementation times (p < 0.05. There was no significant change in explosive power for either group. Our findings support the notion that creatine supplementation increases maximal strength and shortens the optimal individual PAP time of the upper body in high school athletes, but has no effect on explosive power. Moreover, it was found that the recovery time between a bench row and an overhead medicine ball throw in a complex training bout is an individual phenomenon.

Ultrashort pulse laser machining of metals and alloys

Science.gov (United States)

Perry, Michael D.; Stuart, Brent C.

2003-09-16

The invention consists of a method for high precision machining (cutting, drilling, sculpting) of metals and alloys. By using pulses of a duration in the range of 10 femtoseconds to 100 picoseconds, extremely precise machining can be achieved with essentially no heat or shock affected zone. Because the pulses are so short, there is negligible thermal conduction beyond the region removed resulting in negligible thermal stress or shock to the material beyond approximately 0.1-1 micron (dependent upon the particular material) from the laser machined surface. Due to the short duration, the high intensity (>10.sup.12 W/cm.sup.2) associated with the interaction converts the material directly from the solid-state into an ionized plasma. Hydrodynamic expansion of the plasma eliminates the need for any ancillary techniques to remove material and produces extremely high quality machined surfaces with negligible redeposition either within the kerf or on the surface. Since there is negligible heating beyond the depth of material removed, the composition of the remaining material is unaffected by the laser machining process. This enables high precision machining of alloys and even pure metals with no change in grain structure.

The value of creatine kinase, estradiol and progesterone levels in early diagnosis of ectopic pregnancies: a prospective controlled study

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Feride Mimaroğlu

2010-06-01

Full Text Available INTRODUCTION: To evaluate the role of serum creatine kinase, progesterone and estradiol as a biochemical marker in the early diagnosis of tubal pregnancy. MATERIAL-METHODS: A prospective controlled study was carried out on 44 women with first trimester pregnancy. First group (n=22 with tubal pregnancy formed the study group and second group (n=22 with normal intrauterine pregnancy was taken as controls. Serum beta hCG, creatine kinase, progesterone and estradiol levels in the two groups were compared. Surgical treatment had choosen as a treatment modality of ectopic pregnancy. RESULTS: The optimal cutoff value of creatine kinase to be used for the prediction of ectopic pregnancy was 45 IU/l, which resulted in a sensitivity of 86%, specificity of 31%, positive predictive value 55 % and negative predictive value 70 %. The same values for estradiol and progesterone were detected >225 pg/ml, 100 %, 68 %, 75%, 100 % and >13 ng/mL, 95 %, 81 %, % 84, % 97 in discriminating ectopic pregnancies. According to AUC levels there was a significant difference between estradiol-creatine kinase levels, progesterone-estradiol levels and progesterone–creatin kinase levels (p values 0.024, 0.0082, and 0.0001, respectively. CONCLUSION: Serum creatine kinase values appear to be a useful marker in the diagnosis of ectopic pregnancy.

Neuroprotective effect of creatine against propionic acid toxicity in ...

African Journals Online (AJOL)

With sufficient research and clinical trials in future, this could prove to be successful in treatment or management of autism as a neurodevelopmental disorder recently related to PA neurotoxicity. Keywords: Propionic acid, creatine, SH-SY5Y, comet assay, DNA fragmentation assay, apoptosis, neuroprotection. African Journal ...

Effects of plyometric training and creatine supplementation on maximal-intensity exercise and endurance in female soccer players.

Science.gov (United States)

Ramírez-Campillo, Rodrigo; González-Jurado, José Antonio; Martínez, Cristian; Nakamura, Fábio Yuzo; Peñailillo, Luis; Meylan, Cesar M P; Caniuqueo, Alexis; Cañas-Jamet, Rodrigo; Moran, Jason; Alonso-Martínez, Alicia M; Izquierdo, Mikel

2016-08-01

To investigate the effects of a six-week plyometric training and creatine supplementation intervention on maximal-intensity and endurance performance in female soccer players during in-season training. Randomized, double-blind, placebo-controlled trial. Young (age 22.9±2.5y) female players with similar training load and competitive background were assigned to a plyometric training group receiving placebo (PLACEBO, n=10), a plyometric training group receiving creatine supplementation (CREATINE, n=10) or a control group receiving placebo without following a plyometric program (CONTROL, n=10). Athletes were evaluated for jumping, maximal and repeated sprinting, endurance and change-of-direction speed performance before and after six weeks of training. After intervention the CONTROL group did not change, whereas both plyometric training groups improved jumps (ES=0.25-0.49), sprint (ES=0.35-0.41), repeated sprinting (ES=0.48-0.55), endurance (ES=0.32-0.34) and change-of-direction speed performance (ES=0.46-0.55). However, the CREATINE group improved more in the jumps and repeated sprinting performance tests than the CONTROL and the PLACEBO groups. Adaptations to plyometric training may be enhanced with creatine supplementation. Copyright © 2015 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.

Creatine fails to augment the benefits from resistance training in patients with HIV infection: a randomized, double-blind, placebo-controlled study.

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Giorgos K Sakkas

Full Text Available Progressive resistance exercise training (PRT improves physical functioning in patients with HIV infection. Creatine supplementation can augment the benefits derived from training in athletes and improve muscle function in patients with muscle wasting. The objective of this study was to determine whether creatine supplementation augments the effects of PRT on muscle strength, energetics, and body composition in HIV-infected patients.This is a randomized, double blind, placebo-controlled, clinical research center-based, outpatient study in San Francisco. 40 HIV-positive men (20 creatine, 20 placebo enrolled in a 14-week study. Subjects were randomly assigned to receive creatine monohydrate or placebo for 14 weeks. Treatment began with a loading dose of 20 g/day or an equivalent number of placebo capsules for 5 days, followed by maintenance dosing of 4.8 g/day or placebo. Beginning at week 2 and continuing to week 14, all subjects underwent thrice-weekly supervised resistance exercise while continuing on the assigned study medication (with repeated 6-week cycles of loading and maintenance. The main outcome measurements included muscle strength (one repetition maximum, energetics ((31P magnetic resonance spectroscopy, composition and size (magnetic resonance imaging, as well as total body composition (dual-energy X-ray absorptiometry. Thirty-three subjects completed the study (17 creatine, 16 placebo. Strength increased in all 8 muscle groups studied following PRT, but this increase was not augmented by creatine supplementation (average increase 44 vs. 42%, difference 2%, 95% CI -9.5% to 13.9% in creatine and placebo, respectively. There were no differences between groups in changes in muscle energetics. Thigh muscle cross-sectional area increased following resistance exercise, with no additive effect of creatine. Lean body mass (LBM increased to a significantly greater extent with creatine. CONCLUSIONS / SIGNIFICANCE: Resistance exercise improved

The achievements of the Z-machine

International Nuclear Information System (INIS)

Larousserie, D.

2008-01-01

The ZR-machine that represents the latest generation of Z-pinch machines has recently begun preliminary testing before its full commissioning in Albuquerque (Usa). During its test the machine has well operated with electrical currents whose intensities of 26 million Ampere are already 2 times as high as the intensity of the operating current of the previous Z-machine. In 2006 the Z-machine reached temperatures of 2 billions Kelvin while 100 million Kelvin would be sufficient to ignite thermonuclear fusion. In fact the concept of Z-pinch machines was imagined in the fifties but the technological breakthrough that has allowed this recent success and the reborn of Z-machine, was the replacement of gas by an array of metal wires through which the electrical current flows and vaporizes it creating an imploding plasma. It is not well understood why Z-pinch machines generate far more radiation than theoretically expected. (A.C.)

Imprinted polymer-modified hanging mercury drop electrode for differential pulse cathodic stripping voltammetric analysis of creatine.

Science.gov (United States)

Lakshmi, Dhana; Sharma, Piyush S; Prasad, Bhim B

2007-06-15

The molecularly imprinted polymer [poly(p-aminobenzoicacid-co-1,2-dichloroethane)] film casting was made on the surface of a hanging mercury drop electrode by drop-coating method for the selective and sensitive evaluation of creatine in water, blood serum and pharmaceutical samples. The molecular recognition of creatine by the imprinted polymer was found to be specific via non-covalent (electrostatic) imprinting. The creatine binding could easily be detected by differential pulse, cathodic stripping voltammetric signal at optimised operational conditions: accumulation potential -0.01 V (versus Ag/AgCl), polymer deposition time 15s, template accumulation time 60s, pH 7.1 (supporting electrolyte< or =5 x 10(-4)M NaOH), scan rate 10 mV s(-1), pulse amplitude 25 mV. The modified sensor in the present study was found to be highly reproducible and selective with detection limit 0.11 ng mL(-1) of creatine. Cross-reactivity studies revealed no response to the addition of urea, creatinine and phenylalanine; however, some insignificant magnitude of current was observed for tryptophan and histidine in the test samples.

Folic Acid and Creatine as Therapeutic Approaches to Lower Blood Arsenic: A Randomized Controlled Trial.

Science.gov (United States)

Peters, Brandilyn A; Hall, Megan N; Liu, Xinhua; Parvez, Faruque; Sanchez, Tiffany R; van Geen, Alexander; Mey, Jacob L; Siddique, Abu B; Shahriar, Hasan; Uddin, Mohammad Nasir; Islam, Tariqul; Balac, Olgica; Ilievski, Vesna; Factor-Litvak, Pam; Graziano, Joseph H; Gamble, Mary V

2015-12-01

The World Health Organization estimates that > 140 million people worldwide are exposed to arsenic (As)-contaminated drinking water. As undergoes biologic methylation, which facilitates renal As elimination. In folate-deficient individuals, this process is augmented by folic acid (FA) supplementation, thereby lowering blood As (bAs). Creatinine concentrations in urine are a robust predictor of As methylation patterns. Although the reasons for this are unclear, creatine synthesis is a major consumer of methyl donors, and this synthesis is down-regulated by dietary/supplemental creatine. Our aim was to determine whether 400 or 800 μg FA and/or creatine supplementation lowers bAs in an As-exposed Bangladeshi population. We conducted a clinical trial in which 622 participants were randomized to receive 400 μg FA, 800 μg FA, 3 g creatine, 3 g creatine+400 μg FA, or placebo daily. All participants received an As-removal filter on enrollment, and were followed for 24 weeks. After the 12th week, half of the two FA groups were switched to placebo to evaluate post-treatment bAs patterns. Linear models with repeated measures indicated that the decline in ln(bAs) from baseline in the 800-μg FA group exceeded that of the placebo group (weeks 1-12: β= -0.09, 95% CI: -0.18, -0.01; weeks 13-24: FA continued: β= -0.12, 95% CI: -0.24, -0.00; FA switched to placebo: β= -0.14, 95% CI: -0.26, -0.02). There was no rebound in bAs related to cessation of FA supplementation. Declines in bAs observed in the remaining treatment arms were not significantly different from those of the placebo group. In this mixed folate-deficient/replete study population, 12- and 24-week treatment with 800 μg (but not 400 μg) FA lowered bAs to a greater extent than placebo; this was sustained 12 weeks after FA cessation. In future studies, we will evaluate whether FA and/or creatine altered As methylation profiles.

Resistance Training and Co-supplementation with Creatine and Protein in Older Subjects with Frailty.

Science.gov (United States)

Collins, J; Longhurst, G; Roschel, H; Gualano, B

2016-01-01

Studies assessing the effects co-supplementation with creatine and protein, along with resistance training, in older individuals with frailty are lacking. This is an exploratory trial from the Pro-Elderly study ("Protein Intake and Resistance Training in Aging") aimed at gathering knowledge on the feasibility, safety, and efficacy of co-supplementation with creatine and protein supplementation, combined with resistance training, in older individuals with frailty. A 14-week, double-blind, randomized, parallel-group, placebo controlled exploratory trial. The subjects were randomly assigned to whey protein and creatine co-supplementation (WHEY+CR) or whey protein supplementation (WHEY) group. All subjects undertook a supervised exercise training program and were assessed at baseline and after 14 weeks. Muscle function, body composition, blood parameters, and self-reported adverse events were assessed. No interaction effects (between-group differences) were observed for any dependent variables (p > 0.05 for all). However, there were main time-effects in handgrip (WHEY+CR = 26.65 ± 31.29; WHEY = 13.84 ± 14.93 Kg; p = 0.0005), timed-up-and-go (WHEY+CR = -11.20 ± 9.37; WHEY = -17.76 ± 21.74 sec; p = 0.006), and timed-stands test (WHEY+CR = 47.50 ± 35.54; WHEY = 46.87 ± 24.23 reps; p = 0.0001), suggesting that WHEY+CR and WHEY were similarly effective in improving muscle function. All of the subjects showed improvements in at least two of the three functional tests, regardless of their treatments. Body composition and blood parameters were not changed (p > 0.05). No severe adverse effects were observed. Co-supplementation with creatine and whey protein was well-tolerable and free of adverse events in older subjects with frailty undertaking resistance training. Creatine supplementation did not augment the adaptive effects of resistance training along with whey protein on body composition or muscle function in this population. Clinicaltrials.gov: NCT01890382.

Changes in neutrophil count, creatine kinases and muscle soreness ...

African Journals Online (AJOL)

Objective. A primary objective was to examine circulating neutrophil count after repeated bouts of downhill running. An additional aim was to determine creatine kinase (CK) levels during the initial 12 hours, after repeated DHRs. Design. Eleven healthy, untrained Caucasian males performed 2 x 60 min bouts of DHR ...

Periodontal status and serum creatine kinase levels among young ...

African Journals Online (AJOL)

2015-12-02

Dec 2, 2015 ... Key words: Periodontal disease, serum creatine kinase, soccer players ... has also been reported that poor oral health status influences the quality of life of an individual ..... A short‑term longitudinal randomized case‑control study. Clin Oral ... crevicular fluid from chronic periodontitis patients before and after.

Waves and turbulences studies in plasmas: ten years of research on quiescent plasmas at the Brazilian Space Research National Institute

International Nuclear Information System (INIS)

Ferreira, J.L.

1991-01-01

Quiescent plasmas generated by thermionic discharges and surface confined by multipole magnetic fields have been used in basic plasma research since 1973. The first machine was developed at UCLA (USA) to produce an uniform plasma for beam and waves studies in large cross section plasmas. A double quiescent plasma machine was constructed at the plasma laboratory of INPE in 1981, it began its operation producing linear ion-acoustic waves in an Argon plasma. Later on non linear ion acoustic waves and solitons were studied in plasma containing several species of negative and positive ions. The anomalous particle transport across multipole magnetic fields were also investigated. An anomalous resistivity associated with an ion acoustic turbulence is responsible for the formation of a small amplitude double-layer. The existence of a bootstrap mechanism is shown experimentally. Today, the main interest is toward the generation of Langmuir waves in non uniform plasmas. An experimental study on Langmuir wave generation using a grid system is been carried on. A magnetized quiescent plasma device for studies of whistle wave generation is been constructed. This machine will make possible future studies on several wave modes of magnetized plasmas. (author). 31 refs, 16 figs

Effects of exercise intensity and creatine loading on post-resistance exercise hypotension

Directory of Open Access Journals (Sweden)

Moreno Rodrigues Moreno

2009-09-01

Full Text Available Postexercise hypotension plays an important role in the non-pharmacological treat-ment of hypertension and is characterized by a decrease in blood pressure after a single exercise bout in relation to pre-exercise levels. This study investigated the effects of exercise intensity and creatine monohydrate supplementation on postexercise hypotension, as well as the possible role of blood lactate in this response. Ten normotensive subjects underwent resistance exercise sessions before (BC and after (AC creatine supplementation: 1 muscle endurance (ME consisting of 30 repetitions at 30% of one-repetition maximum; 2 hypertrophy (HP consisting of 8 repetitions at 75% of one-repetition maximum. Blood pressure was measured before and after the exercise bout. Blood lactate was measured after the exercise bout. The HP and ME sessions promoted a decrease in systolic blood pressure (∆ -19 ± 1.0 mmHg; ∆ -15 ± 0.9 mmHg, respectively, P 0.05. In conclusion, resistance exercise intensity did not influence postexercise hypotension. Creatine supplementation attenuated the decrease in blood pressure after resistance exercise. The results suggest the involvement of blood lactate in post-resistance exercise hypotension.

Effects of exercise intensity and creatine loading on post-resistance exercise hypotension

Directory of Open Access Journals (Sweden)

Moreno Rodrigues Moreno

2009-01-01

Postexercise hypotension plays an important role in the non-pharmacological treat-ment of hypertension and is characterized by a decrease in blood pressure after a single exercise bout in relation to pre-exercise levels. This study investigated the effects of exercise intensity and creatine monohydrate supplementation on postexercise hypotension, as well as the possible role of blood lactate in this response. Ten normotensive subjects underwent resistance exercise sessions before (BC and after (AC creatine supplementation: 1 muscle endurance (ME consisting of 30 repetitions at 30% of one-repetition maximum; 2 hypertrophy (HP consisting of 8 repetitions at 75% of one-repetition maximum. Blood pressure was measured before and after the exercise bout. Blood lactate was measured after the exercise bout. The HP and ME sessions promoted a decrease in systolic blood pressure (∆ -19 ± 1.0 mmHg; ∆ -15 ± 0.9 mmHg, respectively, P 0.05. In conclusion, resistance exercise intensity did not influence postexercise hypotension. Creatine supplementation attenuated the decrease in blood pressure after resistance exercise. The results suggest the involvement of blood lactate in post-resistance exercise hypotension.

Photonometers for coating and sputtering machines

Science.gov (United States)

Oupický, P.; Jareš, D.; Václavík, J.; Vápenka, D.

2013-04-01

The concept of photonometers (alternative name of optical monitor of a vacuum deposition process) for coating and sputtering machines is based on photonometers produced by companies like SATIS or HV Dresden. Photometers were developed in the TOPTEC centre and its predecessor VOD (Optical Development Workshop of Institut of Plasma Physics AS CR) for more than 10 years. The article describes current status of the technology and ideas which will be incorporated in next development steps. Hardware and software used on coating machines B63D, VNA600 and sputtering machine UPM810 is presented.

Plasma stream transport method (2) Use of charge exchange plasma source

International Nuclear Information System (INIS)

Tsuchimoto, T.

1978-01-01

The plasma stream transport method using a single plasma source has limitations for practical film deposition. Using a charge exchange phenomenon, a new plasma source is devised and tested by the plasma stream transport machine. Metals, silicon dioxide, and nitride films are deposited by this system. The mechanism of deposition under relatively high vacuum surrounding a silicon wafer is discussed as is the effect of radical atoms

Creatine kinase B-driven energy transfer in the brain is important for habituation and spatial learning behaviour, mossy fibre field size and determination of seizure susceptibility.

NARCIS (Netherlands)

Jost, C.R.; Zee, C.E.E.M. van der; Zandt, H.J.A. in t; Oerlemans, F.T.J.J.; Verheij, M.M.M.; Streijger, F.; Fransen, J.A.M.; Deursen, J.; Heerschap, A.; Cools, A.R.; Wieringa, B.

2002-01-01

Creatine kinases are important in maintaining cellular-energy homeostasis, and neuroprotective effects have been attributed to the administration of creatine and creatine-like compounds. Herein we examine whether ablation of the cytosolic brain-type creatine kinase (B-CK) in mice has detrimental

Creatine kinase B-driven energy transfer in the brain is important for habituation and spatial learning behaviour, mossy fibre field size and determination of seizure susceptibility

NARCIS (Netherlands)

Jost, C.R.; Zee, C.E.E.M. van der; Zandt, H.J.A. in t; Oerlemans, F.T.J.J.; Verheij, M.M.M.; Streijger, F.; Fransen, J.A.M.; Heerschap, A.; Cools, A.R.; Wieringa, B.

2002-01-01

Creatine kinases are important in maintaining cellular-energy homeostasis, and neuroprotective effects have been attributed to the administration of creatine and creatine-like compounds. Herein we examine whether ablation of the cytosolic brain-type creatine kinase (B-CK) in mice has detrimental

Neuroprotective effect of creatine against propionic acid toxicity in ...

African Journals Online (AJOL)

edoja

2013-07-31

Jul 31, 2013 ... Full Length Research Paper. Neuroprotective effect of creatine against propionic acid toxicity in neuroblastoma SH-SY5Y cells in culture. Afaf El-Ansary*, Ghada Abu-Shmais and Abeer Al-Dbass. Biochemistry Department, College of Science, King Saud University, P.O. Box 22452, Zip code 11495, Riyadh, ...

Recent results relevant to ignition physics and machine design issues

International Nuclear Information System (INIS)

Coppi, B.; Airoldi, A.; Bombarda, F.

2001-01-01

The plasma regimes under which ignition can be achieved involve a characteristic range of parameters and issues on which information has been provided by recent experiments. In particular, these results have motivated a new, in-depth analysis of the expected performance of the Ignitor machine as well as of the plasma processes that it can investigate. The main results and recent advances in the design of key systems of the machine are reported. (author)

Recent results relevant to ignition physics and machine design issues

International Nuclear Information System (INIS)

Coppi, B.; Airoldi, A.; Bombarda, F.

1999-01-01

The plasma regimes under which ignition can be achieved involve a characteristic range of parameters and issues on which information has been provided by recent experiments. In particular, these results have motivated a new, in-depth analysis of the expected performance of the Ignitor machine as well as of the plasma processes that it can investigate. The main results and recent advances in the design of key systems of the machine are reported. (author)

Raman spectroscopic approach to monitor the in vitro cyclization of creatine → creatinine

Science.gov (United States)

Gangopadhyay, Debraj; Sharma, Poornima; Singh, Sachin Kumar; Singh, Pushkar; Tarcea, Nicolae; Deckert, Volker; Popp, Jürgen; Singh, Ranjan K.

2015-01-01

The creatine → creatinine cyclization, an important metabolic phenomenon has been initiated in vitro at acidic pH and studied through Raman spectroscopic and DFT approach. The equilibrium composition of neutral, zwitterionic and protonated microspecies of creatine has been monitored with time as the reaction proceeds. Time series Raman spectra show clear signature of creatinine formation at pH 3 after ∼240 min at room temperature and reaction is faster at higher temperature. The spectra at pH 1 and pH 5 do not show such signature up to 270 min implying faster reaction rate at pH 3.

Radiation inactivation method provides evidence that membrane-bound mitochondrial creatine kinase is an oligomer

International Nuclear Information System (INIS)

Quemeneur, E.; Eichenberger, D.; Goldschmidt, D.; Vial, C.; Beauregard, G.; Potier, M.

1988-01-01

Lyophilized suspensions of rabbit heart mitochondria have been irradiated with varying doses of gamma rays. Mitochondrial creatine kinase activity was inactivated exponentially with a radiation inactivation size of 352 or 377 kDa depending upon the initial medium. These values are in good agreement with the molecular mass previously deduced from by permeation experiments: 357 kDa. This is the first direct evidence showing that the native form of mitochondrial creatine kinase is associated to the inner membrane as an oligomer, very likely an octamer

Both Creatine and Its Product Phosphocreatine Reduce Oxidative Stress and Afford Neuroprotection in an In Vitro Parkinson’s Model

Directory of Open Access Journals (Sweden)

Mauricio Peña Cunha

2014-10-01

Full Text Available Creatine is the substrate for creatine kinase in the synthesis of phosphocreatine (PCr. This energetic system is endowed of antioxidant and neuroprotective properties and plays a pivotal role in brain energy homeostasis. The purpose of this study was to investigate the neuroprotective effect of creatine and PCr against 6-hydroxydopamine (6-OHDA-induced mitochondrial dysfunction and cell death in rat striatal slices, used as an in vitro Parkinson’s model. The possible involvement of the signaling pathway mediated by phosphatidylinositol-3 kinase (PI3K, protein kinase B (Akt, and glycogen synthase kinase-3β (GSK3β was also evaluated. Exposure of striatal slices to 6-OHDA caused a significant disruption of the cellular homeostasis measured as 3-(4,5 dimethylthiazol-2-yl-2,5-diphenyl-tetrazolium bromide reduction, lactate dehydrogenase release, and tyrosine hydroxylase levels. 6-OHDA exposure increased the levels of reactive oxygen species and thiobarbituric acid reactive substances production and decreased mitochondrial membrane potential in rat striatal slices. Furthermore, 6-OHDA decreased the phosphorylation of Akt (Serine473 and GSK3β (Serine9. Coincubation with 6-OHDA and creatine or PCr reduced the effects of 6-OHDA toxicity. The protective effect afforded by creatine or PCr against 6-OHDA-induced toxicity was reversed by the PI3K inhibitor LY294002. In conclusion, creatine and PCr minimize oxidative stress in striatum to afford neuroprotection of dopaminergic neurons.

Both Creatine and Its Product Phosphocreatine Reduce Oxidative Stress and Afford Neuroprotection in an In Vitro Parkinson’s Model

Science.gov (United States)

Martín-de-Saavedra, Maria D.; Romero, Alejandro; Egea, Javier; Ludka, Fabiana K.; Tasca, Carla I.; Farina, Marcelo; Rodrigues, Ana Lúcia S.; López, Manuela G.

2014-01-01

Creatine is the substrate for creatine kinase in the synthesis of phosphocreatine (PCr). This energetic system is endowed of antioxidant and neuroprotective properties and plays a pivotal role in brain energy homeostasis. The purpose of this study was to investigate the neuroprotective effect of creatine and PCr against 6-hydroxydopamine (6-OHDA)-induced mitochondrial dysfunction and cell death in rat striatal slices, used as an in vitro Parkinson’s model. The possible involvement of the signaling pathway mediated by phosphatidylinositol-3 kinase (PI3K), protein kinase B (Akt), and glycogen synthase kinase-3β (GSK3β) was also evaluated. Exposure of striatal slices to 6-OHDA caused a significant disruption of the cellular homeostasis measured as 3-(4,5 dimethylthiazol-2-yl)-2,5-diphenyl-tetrazolium bromide reduction, lactate dehydrogenase release, and tyrosine hydroxylase levels. 6-OHDA exposure increased the levels of reactive oxygen species and thiobarbituric acid reactive substances production and decreased mitochondrial membrane potential in rat striatal slices. Furthermore, 6-OHDA decreased the phosphorylation of Akt (Serine473) and GSK3β (Serine9). Coincubation with 6-OHDA and creatine or PCr reduced the effects of 6-OHDA toxicity. The protective effect afforded by creatine or PCr against 6-OHDA-induced toxicity was reversed by the PI3K inhibitor LY294002. In conclusion, creatine and PCr minimize oxidative stress in striatum to afford neuroprotection of dopaminergic neurons. PMID:25424428

Photonometers for coating and sputtering machines

Directory of Open Access Journals (Sweden)

Václavík J.

2013-05-01

Full Text Available The concept of photonometers (alternative name of optical monitor of a vacuum deposition process for coating and sputtering machines is based on photonometers produced by companies like SATIS or HV Dresden. Photometers were developed in the TOPTEC centre and its predecessor VOD (Optical Development Workshop of Institut of Plasma Physics AS CR for more than 10 years. The article describes current status of the technology and ideas which will be incorporated in next development steps. Hardware and software used on coating machines B63D, VNA600 and sputtering machine UPM810 is presented.

A new approach to theoretical investigations of high harmonics generation by means of fs laser interaction with overdense plasma layers. Combining particle-in-cell simulations with machine learning

International Nuclear Information System (INIS)

Mihailescu, A.

2016-01-01

Within the past decade, various experimental and theoretical investigations have been performed in the field of high-order harmonics generation (HHG) by means of femtosecond ( fs ) laser pulses interacting with laser produced plasmas. Numerous potential future applications thus arise. Beyond achieving higher conversion efficiency for higher harmonic orders and hence harmonic power and brilliance, there are more ambitious scientific goals such as attaining shorter harmonic wavelengths or reducing harmonic pulse durations towards the attosecond and even the zeptosecond range. High order harmonics are also an attractive diagnostic tool for the laser-plasma interaction process itself. Particle-in-Cell (PIC) simulations are known to be one of the most important numerical instruments employed in plasma physics and in laser-plasma interaction investigations. The novelty brought by this paper consists in combining the PIC method with several machine learning approaches. For predictive modelling purposes, a universal functional approximator is used, namely a multi-layer perceptron (MLP), in conjunction with a self-organizing map (SOM). The training sets have been retrieved from the PIC simulations and also from the available literature in the field. The results demonstrate the potential utility of machine learning in predicting optimal interaction scenarios for gaining higher order harmonics or harmonics with particular features such as a particular wavelength range, a particular harmonic pulse duration or a certain intensity. Furthermore, the author will show how machine learning can be used for estimations of electronic temperatures, proving that it can be a reliable tool for obtaining better insights into the fs laser interaction physics.

Effects of combined creatine and sodium bicarbonate supplementation on repeated sprint performance in trained men.

Science.gov (United States)

Barber, James J; McDermott, Ann Y; McGaughey, Karen J; Olmstead, Jennifer D; Hagobian, Todd A

2013-01-01

Creatine and sodium bicarbonate supplementation independently increase exercise performance, but it remains unclear whether combining these 2 supplements is more beneficial on exercise performance. The purpose of this study was to evaluate the impact of combining creatine monohydrate and sodium bicarbonate supplementation on exercise performance. Thirteen healthy, trained men (21.1 ± 0.6 years, 23.5 ± 0.5 kg·m(-2), 66.7 ± 5.7 ml·(kg·m)(-1) completed 3 conditions in a double-blinded, crossover fashion: (a) Placebo (Pl; 20 g maltodextrin + 0.5 g·kg(-1) maltodextrin), (b) Creatine (Cr; 20 g + 0.5 g·kg(-1) maltodextrin), and (c) Creatine plus sodium bicarbonate (Cr + Sb; 20 g + 0.5 g·kg(-1) sodium bicarbonate). Each condition consisted of supplementation for 2 days followed by a 3-week washout. Peak power, mean power, relative peak power, and bicarbonate concentrations were assessed during six 10-second repeated Wingate sprint tests on a cycle ergometer with a 60-second rest period between each sprint. Compared with Pl, relative peak power was significantly higher in Cr (4%) and Cr + Sb (7%). Relative peak power was significantly lower in sprints 4-6, compared with that in sprint 1, in both Pl and Cr. However, in Cr + Sb, sprint 6 was the only sprint significantly lower compared with sprint 1. Pre-Wingate bicarbonate concentrations were significantly higher in Cr + Sb (10%), compared with in Pl and Cr, and mean concentrations remained higher after sprint 6, although not significantly. Combining creatine and sodium bicarbonate supplementation increased peak and mean power and had the greatest attenuation of decline in relative peak power over the 6 repeated sprints. These data suggest that combining these 2 supplements may be advantageous for athletes participating in high-intensity, intermittent exercise.

Manipulation of Muscle Creatine and Glycogen Changes Dual X-ray Absorptiometry Estimates of Body Composition.

Science.gov (United States)

Bone, Julia L; Ross, Megan L; Tomcik, Kristyen A; Jeacocke, Nikki A; Hopkins, Will G; Burke, Louise M

2017-05-01

Standardizing a dual x-ray absorptiometry (DXA) protocol is thought to provide a reliable measurement of body composition. We investigated the effects of manipulating muscle glycogen and creatine content independently and additively on DXA estimates of lean mass. Eighteen well-trained male cyclists undertook a parallel group application of creatine loading (n = 9) (20 g·d for 5 d loading; 3 g·d maintenance) or placebo (n = 9) with crossover application of glycogen loading (12 v 6 g·kg BM per day for 48 h) as part of a larger study involving a glycogen-depleting exercise protocol. Body composition, total body water, muscle glycogen and creatine content were assessed via DXA, bioelectrical impedance spectroscopy and standard biopsy techniques. Changes in the mean were assessed using the following effect-size scale: >0.2 small, >0.6, moderate, >1.2 large and compared with the threshold for the smallest worthwhile effect of the treatment. Glycogen loading, both with and without creatine loading, resulted in substantial increases in estimates of lean body mass (mean ± SD; 3.0% ± 0.7% and 2.0% ± 0.9%) and leg lean mass (3.1% ± 1.8% and 2.6% ± 1.0%) respectively. A substantial decrease in leg lean mass was observed after the glycogen depleting condition (-1.4% ± 1.6%). Total body water showed substantial increases after glycogen loading (2.3% ± 2.3%), creatine loading (1.4% ± 1.9%) and the combined treatment (2.3% ± 1.1%). Changes in muscle metabolites and water content alter DXA estimates of lean mass during periods in which minimal change in muscle protein mass is likely. This information needs to be considered in interpreting the results of DXA-derived estimates of body composition in athletes.

Chronic high-dose creatine has opposing effects on depression-related gene expression and behavior in intact and sex hormone-treated gonadectomized male and female rats.

Science.gov (United States)

Allen, Patricia J; DeBold, Joseph F; Rios, Maribel; Kanarek, Robin B

2015-03-01

Creatine is an antioxidant, neuromodulator and key regulator of energy metabolism shown to improve depressive symptoms in humans and animals, especially in females. To better understand the pharmacological effects of creatine, we examined its influence on depression-related hippocampal gene expression and behaviors in the presence and absence of sex steroids. Sham-operated and gonadectomized male and female rats were fed chow alone or chow blended with either 2% or 4% w/w creatine monohydrate for five weeks before forced swim, open field, and wire suspension tests, or seven weeks total. Before supplementation, males were chronically implanted with an empty or a testosterone-filled (T) capsule (10-mm surface release), and females were administered progesterone (P, 250 μg), estradiol benzoate (EB, 2.5 μg), EB+P, or sesame oil vehicle weekly. Relative to non-supplemented shams, all hippocampal plasticity-related mRNAs measured, including brain-derived neurotrophic factor (BDNF), tyrosine kinase B, doublecortin, calretinin, and calbindin, were downregulated in sham males given 4% creatine, and BDNF, doublecortin, and calbindin mRNAs were downregulated in sham females given 4% creatine. In contrast, combined 4% creatine+T in castrates prevented downregulation of BDNF, doublecortin, and calretinin mRNAs. Similarly, combined 4% creatine+EB+P in ovariectomized females attenuated downregulation of BDNF and calbindin mRNA levels. Moderate antidepressant and anxiolytic-like behaviors were observed in EB+P-treated ovariectomized females fed creatine, with similar trends in T-treated castrates fed creatine. Altogether, these data show that chronic, high-dose creatine has opposing effects on neuroplasticity-related genes and depressive behavior in intact and gonadectomized male and female rats. The dose and schedule of creatine used negatively impacted hippocampal neuronal integrity in otherwise healthy brains, possibly through negative compensatory changes in energy

Musculus soleus of rats at physical activity and L-carnitine and creatine phosphate effect

Directory of Open Access Journals (Sweden)

Irina A. Khutorskaya

2017-09-01

Full Text Available Introduction: The study of the effect of metabolic drugs on the histochemical characteristics of soleus muscle is relevant for solving the problem of providing the training process in Russia with non-doping drugs for safe correction of the consequences of intense physical activity in athletes. Materials and Methods: Dynamic physical activity in rats (n = 24 was simulated by swimming “to the limit” with weighting of 10 % of body weight (20 days, 1 time per day. The experimental animals were divided into four groups (6 animals each: № 1 – control, № 2 – swimming + isotonic NaCl solution, № 3 and № 4 – swimming + L-carnitine or creatine phosphate 100.0 mg/kg daily intraperitoneally. The object of the study was musculus soleus. Differentiation of muscle fibers was carried out by the intensity of histochemical activity of succinate dehydrogenase (SDG and alkaline stable adenosine triphosphate (ATP of myosin. The percentage of muscle fibers was evaluated and their diameter was defined by the direct morphometry. The obtained data were treated statistically by Student’s T-test. Results: Swimming of the animals “to the limit” do not affect the ratio of fibers with different phenotypes in the soleus muscle. This indicator is genetically determined and was not modified by L-carnitine and creatine phosphate. Dynamic physical activity promotes the development of hypertrophy of muscle fibers of various types. The investigated medicaments of the metabolic type either do not influence on the formation of exerciseinduced hypertrophy (predominantly creatine phosphate or reduce the intensity of the hypertrophic process (predominantly L-carnitine under dynamic physical activity. Discussion and Conclusions: The obtained data indicate L-carnitine and creatine phosphate do not have an anabolic effect. Taking into account the relevant data on ability of L-carnitine and creatine phosphate to effectively correct a negative effects of intensive

The effects of beta alanine plus creatine administration on performance during repeated bouts of supramaximal exercise in sedentary men.

Science.gov (United States)

Okudan, N; Belviranli, M; Pepe, H; Gökbel, H

2015-11-01

The aim of this study was to investigate the effects of beta alanine and/or creatine supplementation on performance during repeated bouts of supramaximal exercise in sedentary men. Forty-four untrained healthy men (aged 20-22 years, weight: 68-72 kg, height: 174-178 cm) participated in the present study. After performing the Wingate Test (WAnT) for three times in the baseline exercise session, the subjects were assigned to one of four treatment groups randomly: 1) placebo (P; 10 g maltodextrose); 2) creatine (Cr; 5 g creatine plus 5 g maltodextrose); 3) beta-alanine (β-ALA; 1,6 g beta alanine plus 8,4 g maltodextrose); and 4) beta-alanine plus creatine (β-ALA+Cr; 1,6 g beta alanine plus 5 g creatine plus 3,4 g maltodextrose). Participants were given the supplements orally twice a day for 22 consecutive days, then four times a day for the following 6 days. After 28 days, the second exercise session was applied during which peak power (PP) and mean power (MP) were measured and fatigue index (FI) was calculated. PP and MP decreased and FI increased in all groups during exercise before and after the treatment. During the postsupplementation session PP2 and PP3 increased in creatine supplemented group (from 642.7±148.6 to 825.1±205.2 in PP2 and from 522.9±117.5 to 683.0±148.0 in PP3, respectively). However, MP increased in β-ALA+Cr during the postsupplementation compared to presupplementation in all exercise sessions (from 586.2±55.4 to 620.6±49.6 in MP1, from 418.1±37.2 to 478.3±30.3 in MP2 and from 362.0±41.3 to 399.1±3 in MP3, respectively). FI did not change with beta alanine and beta alanine plus creatine supplementation during the postsupplementation exercise session. Beta-alanine and beta alanine plus creatine supplementations have strong performance enhancing effect by increasing mean power and delaying fatigue Index during the repeated WAnT.

Development of novel tungsten processing technologies for electro-chemical machining (ECM) of plasma facing components

International Nuclear Information System (INIS)

Holstein, Nils; Krauss, Wolfgang; Konys, Juergen

2011-01-01

Plasma facing components for fusion applications must exhibit long-term stability under extreme conditions, and therefore material imperfections cannot be tolerated due to a high risk of technical failures. To prevent or abolish defects in refractory metals components during the manufacturing process, some methods of electro-chemical machining as S-ECM and C-ECM were developed, enabling both the processing of smooth plain defect-free surfaces of different geometry and the removal of bulk material for the shaping of three-dimensional structures, also without cracks. It is discussed, that tungsten ablation with accurate electro-chemical molding is very sensitive to the kind of electric current, and therefore current investigations focused also on the effects of frequency profiles on the sharpness of edge rounding.

Acute and chronic safety and efficacy of dose dependent creatine nitrate supplementation and exercise performance

OpenAIRE

Galvan, Elfego; Walker, Dillon K.; Simbo, Sunday Y.; Dalton, Ryan; Levers, Kyle; O?Connor, Abigail; Goodenough, Chelsea; Barringer, Nicholas D.; Greenwood, Mike; Rasmussen, Christopher; Smith, Stephen B.; Riechman, Steven E.; Fluckey, James D.; Murano, Peter S.; Earnest, Conrad P.

2016-01-01

Background Creatine monohydrate (CrM) and nitrate are popular supplements for improving exercise performance; yet have not been investigated in combination. We performed two studies to determine the safety and exercise performance-characteristics of creatine nitrate (CrN) supplementation. Methods Study 1 participants (N?=?13) ingested 1.5?g CrN (CrN-Low), 3?g CrN (CrN-High), 5?g CrM or a placebo in a randomized, crossover study (7d washout) to determine supplement safety (hepatorenal and musc...

The B isozyme creatine kinase is active as a fusion protein in Escherichia coli

International Nuclear Information System (INIS)

Koretsky, A.P.; Traxler, B.A.

1989-01-01

A cDNA encoding the B isozyme of creatine kinase CK B has been expressed in Escherichia coli from a fusion with lacZ carried by λgtll. Western blots indicate that a stable polypeptide with the appropriate mobility for the Β-galactosidase-creatine kinase Β-gal-CK B ) fusion protein cross-reacts with both Β-gal and CK B antiserum. No significant CK activity is detected in control E. coli; however, extracts from cells containing the λgtll-CK B construct have a CK activity of 1.54j0.07 μmol/min per mg protein. The fusion protein appears to provide this activity bacause immunoprecipitation of protein with Β-gal antiserum leads to a loss of CK activity from extracts. That the enzyme is active in vivo was demonstrated by detection of a phosphocreatine (PCr) peak in the 31 P NMR spectrum from E. coli grown on medium supplemented with creatine. As in mammalian brain and muscle, the PCr peak detected was sensitive to the energy status of the E. coli. (author). 17 refs.; 3 figs.; 1 tab

Prognostic importance of troponin T and creatine kinase after elective angioplasty

NARCIS (Netherlands)

Nienhuis, Mark B.; Ottervanger, Jan Paul; Dikkeschei, Bert; Suryapranata, Harry; de Boer, Menko-Jan; Dambrink, Jan-Henk E.; Hoorntje, Jan C. A.; van't Hof, Arnoud W. J.; Gosselink, Marcel; Zijlstra, Felix

2007-01-01

Background: The prognostic importance of elevated cardiac enzymes after elective percutaneous coronary intervention has been debated. Therefore, we performed a prospective observational study to evaluate the prognostic value of postprocedural rise of troponin T and creatine kinase. Methods: Troponin

AMP kinase expression and activity in human skeletal muscle: effects of immobilization, retraining, and creatine supplementation

DEFF Research Database (Denmark)

Eijnde, Bert O.; Derave, Wim; Wojtaszewski, Jørgen

2005-01-01

The effects of leg immobilization and retraining in combination with oral creatine intake on muscle AMP-activated protein kinase (AMPK) protein expression and phosphorylation status were investigated. A double-blind trial was performed in young healthy volunteers (n = 22). A cast immobilized...... the right leg for 2 wk, whereafter the knee-extensor muscles of that leg were retrained for 6 wk. Half of the subjects received creatine monohydrate throughout the study (Cr; from 15 g down to 2.5 g daily), and the others ingested placebo (P; maltodextrin). Before and after immobilization and retraining...... that immobilization-induced muscle inactivity for 2 wk does not alter AMPK a1-, a2-, and ß2-subunit expression or a-AMPK phosphorylation status. Furthermore, the present observations indicate that AMPK probably is not implicated in the previously reported beneficial effects of oral creatine supplementation on muscle...

Optimization of Gas Composition Used in Plasma Chemical Vaporization Machining for Figuring of Reaction-Sintered Silicon Carbide with Low Surface Roughness.

Science.gov (United States)

Sun, Rongyan; Yang, Xu; Ohkubo, Yuji; Endo, Katsuyoshi; Yamamura, Kazuya

2018-02-05

In recent years, reaction-sintered silicon carbide (RS-SiC) has been of interest in many engineering fields because of its excellent properties, such as its light weight, high rigidity, high heat conductance and low coefficient of thermal expansion. However, RS-SiC is difficult to machine owing to its high hardness and chemical inertness and because it contains multiple components. To overcome the problem of the poor machinability of RS-SiC in conventional machining, the application of atmospheric-pressure plasma chemical vaporization machining (AP-PCVM) to RS-SiC was proposed. As a highly efficient and damage-free figuring technique, AP-PCVM has been widely applied for the figuring of single-component materials, such as Si, SiC, quartz crystal wafers, and so forth. However, it has not been applied to RS-SiC since it is composed of multiple components. In this study, we investigated the AP-PCVM etching characteristics for RS-SiC by optimizing the gas composition. It was found that the different etching rates of the different components led to a large surface roughness. A smooth surface was obtained by applying the optimum gas composition, for which the etching rate of the Si component was equal to that of the SiC component.

Creatine Supplementation During Resistance Training Does Not Lead to Greater Bone Mineral Density in Older Humans: A Brief Meta-Analysis

Directory of Open Access Journals (Sweden)

Scott C. Forbes

2018-04-01

Full Text Available Creatine supplementation during resistance training has potential beneficial effects on properties of bone in aging adults. We systematically reviewed randomized controlled trials (RCTs investigating the effect of creatine supplementation combined with resistance training on bone mineral density (BMD in aging adults. We searched PubMed and SPORTDiscus databases and included RCTs of ≥3 months duration that examined the combined effect of creatine and resistance training on bone mineral in adults >50 years of age or postmenopausal. Meta-analyses were performed when applicable trials were available on whole body and clinically important bone sites. Five trials met inclusion criteria with a total of 193 participants. Two of the studies reported significant benefits of creatine supplementation and resistance training compared to resistance training alone on bone. Meta-analyses revealed no greater effect of creatine and resistance training compared to resistance training alone on whole body BMD (MD: 0.00, 95% CI −0.01 to 0.01, p = 0.50, hip BMD (MD −0.01, 95% CI −0.02 to 0.01, p = 0.26, femoral neck BMD (MD 0.00, 95% CI −0.01 to 0.01, p = 0.71, and lumbar spine BMD (MD 0.01, 95% CI −0.01 to 0.03, p = 0.32. In conclusion, there is a limited number of RCTs examining the effects of creatine supplementation and resistance training on BMD in older adults. Our meta-analyses revealed no significant effect on whole body, hip, femoral neck, or lumbar spine BMD when comparing creatine and resistance training to resistance training alone. Future longer term (>12 month trials with higher resistance training frequencies (≥3 times per week is warranted.

[Chemical Exchange Saturation Transfer Imaging of Creatine Metabolites: a 3.0 T MRI Pilot].

Science.gov (United States)

Guo, Ying-kun; Li, Zhen-lin; Rong, Yu; Xia, Chun-chao; Zhang, Li-zhi; Peng, Wan-ling; Liu, Xi; Xu, Hua-yan; Zhang, Ti-jiang; Zuo, Pan-li; Schmitt, Benjamin

2016-03-01

To determine the feasibility of using chemical exchange saturation transfer (CEST) imaging to measure creatine (Cr) metabolites with 3.0 T MR. Phantoms containing different concentrations of Cr under various pH conditions were studied with CEST sequence on 3.0 T MR imaging. CEST effect and Z spectra were analyzed. Cr exhibited significant CEST effect (± 1.8 ppm, F = 99.08, P 3.0 T MR imaging, and positive correlation was found between the signal intensity and concentration of Cr (r = 0.963, P 3.0 T MR imaging. Creatine concentrations and pH influence CEST effect.

Review of the Tandem Mirror Experiment-Upgrade (TMX-U) machine-parameter-instrumentation system

International Nuclear Information System (INIS)

Kane, R.J.; Coffield, F.E.; Coutts, G.W.; Hornady, R.S.

1983-01-01

The Tandem Mirror Experiment-Upgrade (TMX-U) machine consists of seven major machine subsystems: magnet system, neutral beam system, microwave heating (ECRH), ion heating (ICRH), gas fueling, stream guns, and vacuum system. Satisfactory performance of these subsystems is necessary to achieve the experimental objectives planned for TMX-U operations. Since the performance quality of the subsystem is important and can greatly affect plasma parameters, a 233-channel instrumentation system has been installed. Data from the instrumentation system are acquired and stored with the plasma diagnostic information. Thus, the details of the machine performance are available during post-shot analysis. This paper describes all the machine-parameter-instrumentation hardware, presents some typical data, and outlines how the data are used

Creatine, Similar to Ketamine, Counteracts Depressive-Like Behavior Induced by Corticosterone via PI3K/Akt/mTOR Pathway.

Science.gov (United States)

Pazini, Francis L; Cunha, Mauricio P; Rosa, Julia M; Colla, André R S; Lieberknecht, Vicente; Oliveira, Ágatha; Rodrigues, Ana Lúcia S

2016-12-01

Ketamine has emerged as a novel strategy to treat refractory depression, producing rapid remission, but elicits some side effects that limit its use. In an attempt to investigate a safer compound that may afford an antidepressant effect similar to ketamine, this study examined the effects of the ergogenic compound creatine in a model of depression, and the involvement of phosphatidylinositol-3-kinase/protein kinase B/mammalian target of rapamycin (PI3K/Akt/mTOR) pathway in its effect. In order to induce a depressive-like behavior, mice were administered with corticosterone (20 mg/kg, per os (p.o.)) for 21 days. This treatment increased immobility time in the tail suspension test (TST), an effect abolished by a single administration of creatine (10 mg/kg, p.o.) or ketamine (1 mg/kg, i.p.), but not by fluoxetine (10 mg/kg, p.o., conventional antidepressant). Treatment of mice with wortmannin (PI3K inhibitor, 0.1 μg/site, intracerebroventricular (i.c.v.)) or rapamycin (mTOR inhibitor, 0.2 nmol/site, i.c.v.) abolished the anti-immobility effect of creatine and ketamine. None of the treatments affected locomotor activity of mice. The immunocontents of p-mTOR, p-p70S6 kinase (p70S6K), and postsynaptic density-95 protein (PSD95) were increased by creatine and ketamine in corticosterone or vehicle-treated mice. Moreover, corticosterone-treated mice presented a decreased hippocampal brain-derived neurotrophic factor (BDNF) level, an effect abolished by creatine or ketamine. Altogether, the results indicate that creatine shares with ketamine the ability to acutely reverse the corticosterone-induced depressive-like behavior by a mechanism dependent on PI3K/AKT/mTOR pathway, and modulation of the synaptic protein PSD95 as well as BDNF in the hippocampus, indicating the relevance of targeting these proteins for the management of depressive disorders. Moreover, we suggest that creatine should be further investigated as a possible fast-acting antidepressant.

Creatine supplementation during pregnancy: summary of experimental studies suggesting a treatment to improve fetal and neonatal morbidity and reduce mortality in high-risk human pregnancy

Science.gov (United States)

2014-01-01

While the use of creatine in human pregnancy is yet to be fully evaluated, its long-term use in healthy adults appears to be safe, and its well documented neuroprotective properties have recently been extended by demonstrations that creatine improves cognitive function in normal and elderly people, and motor skills in sleep-deprived subjects. Creatine has many actions likely to benefit the fetus and newborn, because pregnancy is a state of heightened metabolic activity, and the placenta is a key source of free radicals of oxygen and nitrogen. The multiple benefits of supplementary creatine arise from the fact that the creatine-phosphocreatine [PCr] system has physiologically important roles that include maintenance of intracellular ATP and acid–base balance, post-ischaemic recovery of protein synthesis, cerebral vasodilation, antioxidant actions, and stabilisation of lipid membranes. In the brain, creatine not only reduces lipid peroxidation and improves cerebral perfusion, its interaction with the benzodiazepine site of the GABAA receptor is likely to counteract the effects of glutamate excitotoxicity – actions that may protect the preterm and term fetal brain from the effects of birth hypoxia. In this review we discuss the development of creatine synthesis during fetal life, the transfer of creatine from mother to fetus, and propose that creatine supplementation during pregnancy may have benefits for the fetus and neonate whenever oxidative stress or feto-placental hypoxia arise, as in cases of fetal growth restriction, premature birth, or when parturition is delayed or complicated by oxygen deprivation of the newborn. PMID:24766646

Effects of Creatine and Sodium Bicarbonate Coingestion on Multiple Indices of Mechanical Power Output During Repeated Wingate Tests in Trained Men.

Science.gov (United States)

Griffen, Corbin; Rogerson, David; Ranchordas, Mayur; Ruddock, Alan

2015-06-01

This study investigated the effects of creatine and sodium bicarbonate coingestion on mechanical power during repeated sprints. Nine well-trained men (age = 21.6 ± 0.9 yr, stature = 1.82 ± 0.05 m, body mass = 80.1 ±12.8 kg) participated in a double-blind, placebo-controlled, counterbalanced, crossover study using six 10-s repeated Wingate tests. Participants ingested either a placebo (0.5 g·kg(-1) of maltodextrin), 20 g·d(-1) of creatine monohydrate + placebo, 0.3 g·kg(-1) of sodium bicarbonate + placebo, or coingestion + placebo for 7 days, with a 7-day washout between conditions. Participants were randomized into two groups with a differential counterbalanced order. Creatine conditions were ordered first and last. Indices of mechanical power output (W), total work (J) and fatigue index (W·s(-1)) were measured during each test and analyzed using the magnitude of differences between groups in relation to the smallest worthwhile change in performance. Compared with placebo, both creatine (effect size (ES) = 0.37-0.83) and sodium bicarbonate (ES = 0.22-0.46) reported meaningful improvements on indices of mechanical power output. Coingestion provided small meaningful improvements on indices of mechanical power output (W) compared with sodium bicarbonate (ES = 0.28-0.41), but not when compared with creatine (ES = -0.21-0.14). Coingestion provided a small meaningful improvement in total work (J; ES = 0.24) compared with creatine. Fatigue index (W·s(-1)) was impaired in all conditions compared with placebo. In conclusion, there was no meaningful additive effect of creatine and sodium bicarbonate coingestion on mechanical power during repeated sprints.

The influence of individualizing physical loads on speed, creatine kinase activity and lactate dehydrogenase in football players.

Directory of Open Access Journals (Sweden)

2008-06-01

Full Text Available Introduction: One of the most important training problems in: contemporary football is speed preparation of a player for the season and the ability of keeping it on the same, relatively high level throughout the starting period [1]. The main process used for re-synthesis ATP during single, short-lasting efforts of maximal intensity, is decomposition of phospho-creatine under the influence of creatine kinase enzyme. Physical loads imposed during speed trainings often exceed the possibility of producing energy from phosphogenic reserve through oxygen - lactate free processes, because the supply of phospho-creatine is used very quickly. In such circumstances the lacking energy is refilled through processes called oxygen free glicolise with the help of lactate dehydrogenase enzyme. The aim of the work was to answer the question:

Creatine monohydrate supplementation does not increase muscle strength, lean body mass, or muscle phosphocreatine in patients with myotonic dystrophy type 1.

Science.gov (United States)

Tarnopolsky, Mark; Mahoney, Douglas; Thompson, Terry; Naylor, Heather; Doherty, Timothy J

2004-01-01

Creatine monohydrate (CrM) supplementation may increase strength in some types of muscular dystrophy. A recent study in myotonic muscular dystrophy type 1 (DM1) did not find a significant treatment effect, but measurements of muscle phosphocreatine (PCr) were not performed. We completed a randomized, double-blind, cross-over trial using 34 genetically confirmed adult DM1 patients without significant cognitive impairment. Participants received CrM (5 g, approximately 0.074 g/kg daily) and a placebo for each 4-month phase with a 6-week wash-out. Spirometry, manual muscle testing, quantitative isometric strength testing of handgrip, foot dorsiflexion, and knee extension, handgrip and foot dorsiflexion endurance, functional tasks, activity of daily living scales, body composition (total, bone, and fat-free mass), serum creatine kinase activity, serum creatinine concentration and clearance, and liver function tests were completed before and after each intervention, and muscle PCr/beta-adenosine triphosphate (ATP) ratios of the forearm flexor muscles were completed at the end of each phase. CrM supplementation did not increase any of the outcome measurements except for plasma creatinine concentration (but not creatinine clearance). Thus, CrM supplementation at 5 g daily does not have any effects on muscle strength, body composition, or activities of daily living in patients with DM1, perhaps because of a failure of the supplementation to increase muscle PCr/beta-ATP content.

New DIII-D tokamak plasma control system

International Nuclear Information System (INIS)

Campbell, G.L.; Ferron, J.R.; McKee, E.; Nerem, A.; Smith, T.; Greenfield, C.M.; Pinsker, R.I.; Lazarus, E.A.

1992-09-01

A state-of-the-art plasma control system has been constructed for use on the DIII-D tokamak to provide high speed real time data acquisition and feedback control of DIII-D plasma parameters. This new system has increased the precision to which discharge shape and position parameters can be maintained and has provided the means to rapidly change from one plasma configuration to another. The capability to control the plasma total energy and the ICRF antenna loading resistance has been demonstrated. The speed and accuracy of this digital system will allow control of the current drive and heating systems in order to regulate the current and pressure profiles and diverter power deposition in the DIII-D machine. Use of this system will allow the machine and power supplies to be better protected from undesirable operating regimes. The advanced control system is also suitable for control algorithm development for future machines in these areas and others such as disruption avoidance. The DIII-D tokamak facility is operated for the US Department of Energy by General Atomics Company (GA) in San Diego, California. The DIII-D experimental program will increase emphasis on rf heating and current drive in the near future and is installing a cryopumped divertor ring during the fall of 1992. To improve the flexibility of this machine for these experiments, the new shape control system was implemented. The new advanced plasma control system has enhanced the capabilities of the DIII-D machine and provides a data acquisition and control platform that promises to be useful far beyond its original charter

Creatine kinase in the serum of patients with acute infections of the central nervous system

DEFF Research Database (Denmark)

Peterslund, N A; Heinsvig, E M; Christensen, K D

1985-01-01

Serum creatine kinase was assessed in 94 consecutive patients without convulsions admitted to hospital due to suspicion of infection of the central nervous system. No reliable discrimination between patients with aseptic and those with bacterial meningitis was obtained. Patients with bacterial...... of bacterial meningitis. The highest serum CK value found in patients with encephalitis was 725 U/l. Reference values for control patients with meningism were 16-269 U/1. In a subset of 9 patients creatine kinase isoenzyme analysis was performed. In all cases only muscle type (MM) isoenzyme was found...

A randomized, double-blind, placebo-controlled, proof-of-concept trial of creatine monohydrate as adjunctive treatment for bipolar depression.

Science.gov (United States)

Toniolo, Ricardo Alexandre; Silva, Michelle; Fernandes, Francy de Brito Ferreira; Amaral, José Antonio de Mello Siqueira; Dias, Rodrigo da Silva; Lafer, Beny

2018-02-01

Depressive episodes are a major cause of morbidity and dysfunction in individuals suffering from bipolar disorder. Currently available treatments for this condition have limited efficacy and new therapeutic options are needed. Extensive research in the pathophysiology of bipolar disorder points to the existence of mitochondrial and bioenergetic dysfunction. We hypothesized that creatine monohydrate, a nutraceutical that works as a mitochondrial modulator, would be effective as an adjunctive therapy for bipolar depression. We conducted a double-blind trial in which 35 patients with bipolar disorder type I or II in a depressive episode by DSM-IV criteria and in use of regular medication for the treatment of this phase of the disease were randomly allocated into two adjunctive treatment groups for 6 weeks: creatine monohydrate 6 g daily (N = 17) or placebo (N = 18). Primary efficacy was assessed by the change in the Montgomery-Åsberg Depression Rating Scale (MADRS). We did not find a statistically significant difference in the comparison between groups for the change in score on the MADRS after 6 weeks in an intention-to-treat (ITT) analysis (p = 0.560; Cohen's d = 0.231). However, we found significant superiority of creatine add-on vs. placebo when we considered the remission criterion of a MADRS score ≤ 12 at week 6 analyzing the outcome of the 35 randomized patients on ITT (52.9% remission in the creatine group vs. 11.1% remission in the placebo group) and of the 23 completers (66.7% remission in the creatine group vs. 18.2% remission in the placebo group) (p = 0.012; OR = 9.0 and p = 0.036; OR = 9.0, respectively). Two patients who received creatine switched to hypomania/mania early in the trial. No clinically relevant physical side-effects were reported or observed. This proof-of-concept study, aiming to restore brain bioenergetics using an adjunctive mitochondrial modulator, is not conclusive on the efficacy of creatine add-on for bipolar

Utilization of glutamate/creatine ratios for proton spectroscopic diagnosis of meningiomas

International Nuclear Information System (INIS)

Hazany, Saman; Hesselink, John R.; Healy, John F.; Imbesi, Steven G.

2007-01-01

Our purpose was to determine the potential of metabolites other than alanine to diagnose intracranial meningiomas on proton magnetic resonance spectroscopy (MRS). Using a 1.5-T MR system the lesions were initially identified on FLAIR, and T1- and T2-weighted images. Employing standard point-resolved spectroscopy (PRESS) for single voxel proton MRS (TR 1500 ms, TE 30 ms, 128 acquisitions, voxel size 2 x 2 x 2 cm, acquisition time 3.12 min), MR spectra were obtained from 5 patients with meningiomas, from 20 with other intracranial lesions, and from 4 normal controls. Peak heights of nine resonances, including lipid, lactate, alanine, NAA (N-acetylaspartate), β/γ-Glx (glutamate + glutamine), creatine, choline, myo-inositol, and α-Glx/glutathione, were measured in all spectra. The relative quantity of each metabolite was measured as the ratio of its peak height to the peak height of creatine. Relative quantities of α-Glx/glutathione, β/γ-Glx, and total Glx/glutathione were significantly elevated in meningiomas compared to the 20 other intracranial lesions and the normal control brains. Alanine was found in four of five meningiomas, but lactate partially masked the alanine in three meningiomas. None of the other lesions or control brains showed an alanine peak. The one meningioma with no alanine and the three others with lactate had elevated Glx. While alanine is a relatively unique marker for meningioma, our results support the hypothesis that the combination of glutamate/creatine ratios and alanine on proton MRS is more specific and reliable for the diagnosis of meningiomas than alanine alone. (orig.)

Utilization of glutamate/creatine ratios for proton spectroscopic diagnosis of meningiomas

Energy Technology Data Exchange (ETDEWEB)

Hazany, Saman [University of California, School of Medicine, San Diego, CA (United States); Hesselink, John R.; Healy, John F.; Imbesi, Steven G. [UCSD Medical Center, Department of Radiology, San Diego, CA (United States)

2007-02-15

Our purpose was to determine the potential of metabolites other than alanine to diagnose intracranial meningiomas on proton magnetic resonance spectroscopy (MRS). Using a 1.5-T MR system the lesions were initially identified on FLAIR, and T1- and T2-weighted images. Employing standard point-resolved spectroscopy (PRESS) for single voxel proton MRS (TR 1500 ms, TE 30 ms, 128 acquisitions, voxel size 2 x 2 x 2 cm, acquisition time 3.12 min), MR spectra were obtained from 5 patients with meningiomas, from 20 with other intracranial lesions, and from 4 normal controls. Peak heights of nine resonances, including lipid, lactate, alanine, NAA (N-acetylaspartate), {beta}/{gamma}-Glx (glutamate + glutamine), creatine, choline, myo-inositol, and {alpha}-Glx/glutathione, were measured in all spectra. The relative quantity of each metabolite was measured as the ratio of its peak height to the peak height of creatine. Relative quantities of {alpha}-Glx/glutathione, {beta}/{gamma}-Glx, and total Glx/glutathione were significantly elevated in meningiomas compared to the 20 other intracranial lesions and the normal control brains. Alanine was found in four of five meningiomas, but lactate partially masked the alanine in three meningiomas. None of the other lesions or control brains showed an alanine peak. The one meningioma with no alanine and the three others with lactate had elevated Glx. While alanine is a relatively unique marker for meningioma, our results support the hypothesis that the combination of glutamate/creatine ratios and alanine on proton MRS is more specific and reliable for the diagnosis of meningiomas than alanine alone. (orig.)

Leak tightness tests on actively cooled plasma facing components: Lessons learned from Tore Supra experience and perspectives for the new fusion machines

Energy Technology Data Exchange (ETDEWEB)

Chantant, M., E-mail: michel.chantant@cea.fr; Lambert, R.; Gargiulo, L.; Hatchressian, J.-C.; Guilhem, D.; Samaille, F.; Soler, B.

2015-10-15

Highlights: • Test procedures for the qualification of the tightness of actively cooled plasma facing components were defined. • The test is performed after the component manufacturing and before its set-up in the vacuum vessel. • It allows improving the fusion machine availability. • The lessons of tests over 20 years at Tore Supra are presented. - Abstract: The fusion machines under development or construction (ITER, W7X) use several hundreds of actively cooled plasma facing components (ACPFC). They are submitted to leak tightness requirements in order to get an appropriate vacuum level in the vessel to create the plasma. During the ACPFC manufacturing and before their installation in the machine, their leak tightness performance must be measured to check that they fulfill the vacuum requirements. A relevant procedure is needed which allows to segregate potential defects. It must also be optimized in terms of test duration and costs. Tore Supra, as an actively cooled Tokamak, experienced several leaks on ACPFCs during the commissioning and during the operation of the machine. A test procedure was then defined and several test facilities were set-up. Since 1990 the tightness of all the new ACPFCs is systematically tested before their installation in Tore Supra. During the qualification test, the component is set up in a vacuum test tank, and its cooling circuits are pressurized with helium. It is submitted to 3 temperature cycles from room temperature up to the baking temperature level in Tore Supra (200 °C) and two pressurization tests are performed (6 MPa at room temperature and 4 MPa at 200 °C) at each stage. At the end of the last cycle when the ACPFC is at room temperature and pressurized with helium at 6 MPa, the measured leak rate must be lower than 5 × 10{sup −11} Pa m{sup 3} s{sup −1}, the pressure in the test tank being <5 × 10{sup −5} Pa. A large experience has been gained on ACPFCs with carbon parts on stainless steel and Cu

Monoclonal antibody FsC-47 against carp sperm creatine kinase

Czech Academy of Sciences Publication Activity Database

Koubek, Pavel; Elzeinová, Fatima; Šulc, Miroslav; Linhart, O.; Pěknicová, Jana

2006-01-01

Roč. 25, č. 3 (2006), s. 154-157 ISSN 1554-0014 R&D Projects: GA ČR(CZ) GA524/03/0178 Institutional research plan: CEZ:AV0Z50520514; CEZ:AV0Z50200510 Keywords : creatin kinase * monoclonal antibody * carp sperm Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 0.411, year: 2006

A one-dimensional Q-machine model taking into account charge-exchange collisions

International Nuclear Information System (INIS)

Maier, H.; Kuhn, S.

1992-01-01

The Q-machine is a nontrivial bounded plasma system which is excellently suited not only for fundamental plasma physics investigations but also for the development and testing of new theoretical methods for modeling such systems. However, although Q-machines have now been around for over thirty years, it appears that there exist no comprehensive theoretical models taking into account their considerable geometrical and physical complexity with a reasonable degree of self-consistency. In the present context we are concerned with the low-density, single-emitter Q-machine, for which the most widely used model is probably the (one-dimensional) ''collisionless plane-diode model'', which has originally been developed for thermionic diodes. Although the validity of this model is restricted to certain ''axial'' phenomena, we consider it a suitable starting point for extensions of various kinds. While a generalization to two-dimensional geometry (with still collisionless plasma) is being reported elsewhere, the present work represents a first extension to collisional plasma (with still one-dimensional geometry). (author) 12 refs., 2 figs

Is long term creatine and glutamine supplementation effective in enhancing physical performance of military police officers?

Science.gov (United States)

da Silveira, Celismar Lázaro; de Souza, Thiago Siqueira Paiva; Batista, Gilmário Ricarte; de Araújo, Adenilson Targino; da Silva, Júlio César Gomes; de Sousa, Maria do Socorro Cirilo; Marta, Carlos; Garrido, Nuno Domingo

2014-09-29

The objective of this study was to analyze the effect of supplementation with creatine and glutamine on physical fitness of military police officers. Therefore, an experimental double blind study was developed, with the final sample composed by 32 men randomly distributed into three groups: a group supplemented with creatine (n=10), glutamine (n=10) and a placebo group (n=12) and evaluated in three distinct moments, in an interval of three months (T1, T2 and T3). The physical training had a weekly frequency of 5 sessions × 90 min, including strength exercises, local muscular resistance, flexibility and both aerobic and anaerobic capacity. After analyzing the effect of time, group and interaction (group × time) for measures that indicated the physical capabilities of the subjects, a significant effect of time for the entire variable was identified (p0,05). In face of the results it was concluded that supplementation with creatine and glutamine showed no ergogenic effect on physical performance in military police officers.

A review of creatine supplementation in age-related diseases: more than a supplement for athletes [v1; ref status: indexed, http://f1000r.es/4ak

Directory of Open Access Journals (Sweden)

Rachel N. Smith

2014-09-01

Full Text Available Creatine is an endogenous compound synthesized from arginine, glycine and methionine. This dietary supplement can be acquired from food sources such as meat and fish, along with athlete supplement powders. Since the majority of creatine is stored in skeletal muscle, dietary creatine supplementation has traditionally been important for athletes and bodybuilders to increase the power, strength, and mass of the skeletal muscle. However, new uses for creatine have emerged suggesting that it may be important in preventing or delaying the onset of neurodegenerative diseases associated with aging. On average, 30% of muscle mass is lost by age 80, while muscular weakness remains a vital cause for loss of independence in the elderly population. In light of these new roles of creatine, the dietary supplement’s usage has been studied to determine its efficacy in treating congestive heart failure, gyrate atrophy, insulin insensitivity, cancer, and high cholesterol. In relation to the brain, creatine has been shown to have antioxidant properties, reduce mental fatigue, protect the brain from neurotoxicity, and improve facets/components of neurological disorders like depression and bipolar disorder. The combination of these benefits has made creatine a leading candidate in the fight against age-related diseases, such as Parkinson’s disease, Huntington’s disease, amyotrophic lateral sclerosis, long-term memory impairments associated with the progression of Alzheimer’s disease, and stroke. In this review, we explore the normal mechanisms by which creatine is produced and its necessary physiology, while paying special attention to the importance of creatine supplementation in improving diseases and disorders associated with brain aging and outlining the clinical trials involving creatine to treat these diseases.

Rate equation for creatine kinase predicts the in vivo reaction velocity: 31P NMR surface coil studies in brain, heart, and skeletal muscle of the living rat

International Nuclear Information System (INIS)

Bittl, J.A.; DeLayre, J.; Ingwall, J.S.

1987-01-01

Brain, heart, and skeletal muscle contain four different creatine kinase isozymes and various concentrations of substrates for the creatine kinase reaction. To identify if the velocity of the creatine kinase reaction under cellular conditions is regulated by enzyme activity and substrate concentrations as predicted by the rate equation, the authors used 31 P NMR and spectrophotometric techniques to measure reaction velocity, enzyme content, isozyme distribution, and concentrations of substrates in brain, heart, and skeletal muscle of living rat under basal or resting conditions. The total tissue activity of creatine kinase in the direction of MgATP synthesis provided an estimate for V/sub max/ and exceeded the NMR-determined in vivo reaction velocities by an order of magnitude. The isozyme composition varied among the three tissues: >99% BB for brain; 14% MB, 61% MM, and 25% mitochondrial for heart; and 98% MM and 2% mitochondrial for skeletal muscle. The NMR-determined reaction velocities agreed with predicted values from the creatine kinase rate equation. The concentrations of free creatine and cytosolic MgADP, being less than or equal to the dissociation constants for each isozyme, were dominant terms in the creatine kinase rate equation for predicting the in vivo reaction velocity. Thus, they observed that the velocity of the creatine kinase reaction is regulated by total tissue enzyme activity and by the concentrations of creatine and MgADP in a manner that is independent of isozyme distribution

A review of creatine supplementation in age-related diseases: more than a supplement for athletes [v1; ref status: indexed, http://f1000r.es/4ak

OpenAIRE

Rachel N. Smith; Amruta S. Agharkar; Eric B. Gonzales

2014-01-01

Creatine is an endogenous compound synthesized from arginine, glycine and methionine. This dietary supplement can be acquired from food sources such as meat and fish, along with athlete supplement powders. Since the majority of creatine is stored in skeletal muscle, dietary creatine supplementation has traditionally been important for athletes and bodybuilders to increase the power, strength, and mass of the skeletal muscle. However, new uses for creatine have emerged suggesting that it may b...

Effects of creatine supplementation on oxidative stress profile of athletes

Science.gov (United States)

2012-01-01

Background Creatine (Cr) supplementation has been widely used among athletes and physically active individuals. Secondary to its performance-enhancing ability, an increase in oxidative stress may occur, thus prompting concern about its use. The purpose of this study is to investigate the effects of Cr monohydrate supplementation and resistance training on muscle strength and oxidative stress profile in healthy athletes. Methods A randomized, double-blind, placebo-controlled method was used to assess twenty-six male elite Brazilian handball players divided into 3 groups: Cr monohydrate supplemented group (GC, N = 9), placebo group (GP, N = 9), no treatment group (COT, N = 8) for 32 days. All subjects underwent a resistance training program. Blood samples were drawn on 0 and 32 days post Cr supplementation to analyze the oxidative stress markers, thiobarbituric acid reactive species (TBARS), total antioxidant status (TAS), and uric acid. Creatine phosphokinase, urea, and creatinine were also analyzed, as well. Fitness tests (1 repetition maximum - 1RM and muscle endurance) were performed on the bench press. Body weight and height, body fat percentage (by measuring skin folds) and upper muscular area were also evaluated. Statistical analysis was performed using ANOVA. Results Only GC group showed increase in 1RM (54 ± 9 vs. 63 ± 10 kg; p = 0.0356) and uric acid (4.6 ± 1.0 vs. 7.4 ± 1.6 mg/dl; p = 0.025), with a decrease in TAS (1.11 ± 0.34 vs. 0.60 ± 0.19 mmol/l; p = 0.001). No differences (pre- vs. post-training) in TBARS, creatine phosphokinase, urea, creatinine, body weight and height, body fat percentage, or upper muscular area were observed in any group. When compared to COT, GC group showed greater decrease in TAS (−0.51 ± 0.36 vs. -0.02 ± 0.50 mmol/l; p = 0.0268), higher increase in 1RM (8.30 ± 2.26 vs. 5.29 ± 2.36 kg; p = 0.0209) and uric acid (2.77 ± 1.70 vs. 1.00 ± 1.03 mg/dl; p = 0.0276). Conclusion We conclude that Cr monohydrate

Effects of creatine supplementation on oxidative stress profile of athletes

Directory of Open Access Journals (Sweden)

Percário Sandro

2012-12-01

Full Text Available Abstract Background Creatine (Cr supplementation has been widely used among athletes and physically active individuals. Secondary to its performance-enhancing ability, an increase in oxidative stress may occur, thus prompting concern about its use. The purpose of this study is to investigate the effects of Cr monohydrate supplementation and resistance training on muscle strength and oxidative stress profile in healthy athletes. Methods A randomized, double-blind, placebo-controlled method was used to assess twenty-six male elite Brazilian handball players divided into 3 groups: Cr monohydrate supplemented group (GC, N = 9, placebo group (GP, N = 9, no treatment group (COT, N = 8 for 32 days. All subjects underwent a resistance training program. Blood samples were drawn on 0 and 32 days post Cr supplementation to analyze the oxidative stress markers, thiobarbituric acid reactive species (TBARS, total antioxidant status (TAS, and uric acid. Creatine phosphokinase, urea, and creatinine were also analyzed, as well. Fitness tests (1 repetition maximum - 1RM and muscle endurance were performed on the bench press. Body weight and height, body fat percentage (by measuring skin folds and upper muscular area were also evaluated. Statistical analysis was performed using ANOVA. Results Only GC group showed increase in 1RM (54 ± 9 vs. 63 ± 10 kg; p = 0.0356 and uric acid (4.6 ± 1.0 vs. 7.4 ± 1.6 mg/dl; p = 0.025, with a decrease in TAS (1.11 ± 0.34 vs. 0.60 ± 0.19 mmol/l; p = 0.001. No differences (pre- vs. post-training in TBARS, creatine phosphokinase, urea, creatinine, body weight and height, body fat percentage, or upper muscular area were observed in any group. When compared to COT, GC group showed greater decrease in TAS (−0.51 ± 0.36 vs. -0.02 ± 0.50 mmol/l; p = 0.0268, higher increase in 1RM (8.30 ± 2.26 vs. 5.29 ± 2.36 kg; p = 0.0209 and uric acid (2.77 ± 1.70 vs. 1.00 ± 1.03 mg/dl; p = 0.0276. Conclusion We conclude that Cr

Relationship between elevated creatine phosphokinase and the clinical spectrum of rhabdomyolysis

NARCIS (Netherlands)

Veenstra, J.; Smit, W. M.; Krediet, R. T.; Arisz, L.

1994-01-01

The incidence, causes and complications of severe rhabdomyolysis (creatine phosphokinase (CK) > or = 5000 U/l) were studied during a 7-year study period in a large university hospital population. This condition was present in 0.074% of all admitted patients. The mortality in the study group (n = 93)

Involvement of PI3K/Akt Signaling Pathway and Its Downstream Intracellular Targets in the Antidepressant-Like Effect of Creatine.

Science.gov (United States)

Cunha, Mauricio P; Budni, Josiane; Ludka, Fabiana K; Pazini, Francis L; Rosa, Julia Macedo; Oliveira, Ágatha; Lopes, Mark W; Tasca, Carla I; Leal, Rodrigo B; Rodrigues, Ana Lúcia S

2016-07-01

Creatine has been proposed to exert beneficial effects in the management of depression, but the cell signaling pathways implicated in its antidepressant effects are not well established. This study investigated the involvement of PI3K/Akt signaling pathway and its downstream intracellular targets in the antidepressant-like effect of creatine. The acute treatment of mice with creatine (1 mg/kg, po) increased the Akt and P70S6K phosphorylation, and HO-1, GPx and PSD95 immunocontents. The pretreatment of mice with LY294002 (10 nmol/mouse, icv, PI3K inhibitor), wortmannin (0.1 μg/mouse, icv, PI3K inhibitor), ZnPP (10 μg/mouse, icv, HO-1 inhibitor), or rapamycin (0.2 nmol/mouse, icv, mTOR inhibitor) prevented the antidepressant-like effect of creatine (1 mg/kg, po) in the TST. In addition, the administration of subeffective dose of either the selective GSK3 inhibitor AR-A014418 (0.01 μg/mouse, icv), the nonselective GSK3 inhibitor lithium chloride (10 mg/kg, po), or the HO-1 inductor CoPP (0.01 μg/mouse, icv), in combination with a subeffective dose of creatine (0.01 mg/kg, po) reduced the immobility time in the TST as compared with either drug alone. No treatment caused significant changes in the locomotor activity of mice. These results indicate that the antidepressant-like effect of creatine in the TST depends on the activation of Akt, Nrf2/HO-1, GPx, and mTOR, and GSK3 inhibition.

Level of hamstrings damage depending on force-generating capacity and creatine kinase activity

OpenAIRE

Carmona, Gerard; Alomar, Xavier; Mendiguchia, Jurdan; Serrano, David; Padullés, Josep Maria; Nescolarde Selva, Lexa Digna; Rodas Font, Gil; Cusso Calabuig, Roser; Guerrero, M.; Idoate, F.; Balius, Ramon; Cadefau, Joan

2014-01-01

The aim of the present study was to categorize the eccentric exercise-induced hamstrings damage by using easy measurable markers such as force-generating capacity and serum creatine kinase activity Peer Reviewed

Creatine-induced activation of antioxidative defence in myotube cultures revealed by explorative NMR-based metabonomics and proteomics

Directory of Open Access Journals (Sweden)

Nielsen Niels

2010-02-01

Full Text Available Abstract Background Creatine is a key intermediate in energy metabolism and supplementation of creatine has been used for increasing muscle mass, strength and endurance. Creatine supplementation has also been reported to trigger the skeletal muscle expression of insulin like growth factor I, to increase the fat-free mass and improve cognition in elderly, and more explorative approaches like transcriptomics has revealed additional information. The aim of the present study was to reveal additional insight into the biochemical effects of creatine supplementation at the protein and metabolite level by integrating the explorative techniques, proteomics and NMR metabonomics, in a systems biology approach. Methods Differentiated mouse myotube cultures (C2C12 were exposed to 5 mM creatine monohydrate (CMH for 24 hours. For proteomics studies, lysed myotubes were analyzed in single 2-DGE gels where the first dimension of protein separation was pI 5-8 and second dimension was a 12.5% Criterion gel. Differentially expressed protein spots of significance were excised from the gel, desalted and identified by peptide mass fingerprinting using MALDI-TOF MS. For NMR metabonomic studies, chloroform/methanol extractions of the myotubes were subjected to one-dimensional 1H NMR spectroscopy and the intracellular oxidative status of myotubes was assessed by intracellular DCFH2 oxidation after 24 h pre-incubation with CMH. Results The identified differentially expressed proteins included vimentin, malate dehydrogenase, peroxiredoxin, thioredoxin dependent peroxide reductase, and 75 kDa and 78 kDa glucose regulated protein precursors. After CMH exposure, up-regulated proteomic spots correlated positively with the NMR signals from creatine, while down-regulated proteomic spots were negatively correlated with these NMR signals. The identified differentially regulated proteins were related to energy metabolism, glucose regulated stress, cellular structure and the

Treatment with Creatine Monohydrate in Spinal and Bulbar Muscular Atrophy: Protocol for a Randomized, Double-Blind, Placebo-Controlled Trial.

Science.gov (United States)

Hijikata, Yasuhiro; Katsuno, Masahisa; Suzuki, Keisuke; Hashizume, Atsushi; Araki, Amane; Yamada, Shinichiro; Inagaki, Tomonori; Ito, Daisuke; Hirakawa, Akihiro; Kinoshita, Fumie; Gosho, Masahiko; Sobue, Gen

2018-03-05

Although spinal and bulbar muscular atrophy (SBMA) has been classified as a motor neuron disease, several reports have indicated the primary involvement of skeletal muscle in the pathogenesis of this devastating disease. Recent studies reported decreased intramuscular creatine levels in skeletal muscles in both patients with SBMA and transgenic mouse models of SBMA, which appears to contribute to muscle weakness. The present study aimed to examine the efficacy and safety of oral creatine supplementation to improve motor function in patients with SBMA. A randomized, double-blind, placebo-controlled, three-armed clinical trial was conducted to assess the safety and efficacy of creatine therapy in patients with SBMA. Patients with SBMA eligible for this study were assigned randomly in a 1:1:1 ratio to each group of placebo, 10 g, or 15 g daily dose of creatine monohydrate in a double-blind fashion. Participants took creatine or placebo orally 3 times a day for 8 weeks. Outcome measurements were results of neurological assessments, examinations, and questionnaires collected at baseline and at weeks 4, 8, and 16 after a washout period. The primary endpoint was the change in handgrip strength values from baseline to week 8. The secondary endpoints included the following: results of maximum voluntary isometric contraction tests of extremities; tongue pressure; results of the 15-foot timed walk test and the rise from bed test; modified quantitative myasthenia gravis score; respiratory function test results; activities of daily living assessed with the Revised Amyotrophic Lateral Sclerosis Functional Rating Scale and the Spinal and Bulbar Muscular Atrophy Functional Rating Scale; skeletal muscle mass measured with dual-energy X-ray absorptiometry; urinary 8-hydroxydeoxyguanosine levels; and questionnaires examining the quality of life, swallowing function, and fatigue. Participant enrollment in the trial started from June 2014 and follow-up was completed in July 2015. The

Performance of a plasma fluid code on the Intel parallel computers

International Nuclear Information System (INIS)

Lynch, V.E.; Carreras, B.A.; Drake, J.B.; Leboeuf, J.N.; Liewer, P.

1992-01-01

One approach to improving the real-time efficiency of plasma turbulence calculations is to use a parallel algorithm. A parallel algorithm for plasma turbulence calculations was tested on the Intel iPSC/860 hypercube and the Touchtone Delta machine. Using the 128 processors of the Intel iPSC/860 hypercube, a factor of 5 improvement over a single-processor CRAY-2 is obtained. For the Touchtone Delta machine, the corresponding improvement factor is 16. For plasma edge turbulence calculations, an extrapolation of the present results to the Intel σ machine gives an improvement factor close to 64 over the single-processor CRAY-2

Performance of a plasma fluid code on the Intel parallel computers

Science.gov (United States)

Lynch, V. E.; Carreras, B. A.; Drake, J. B.; Leboeuf, J. N.; Liewer, P.

1992-01-01

One approach to improving the real-time efficiency of plasma turbulence calculations is to use a parallel algorithm. A parallel algorithm for plasma turbulence calculations was tested on the Intel iPSC/860 hypercube and the Touchtone Delta machine. Using the 128 processors of the Intel iPSC/860 hypercube, a factor of 5 improvement over a single-processor CRAY-2 is obtained. For the Touchtone Delta machine, the corresponding improvement factor is 16. For plasma edge turbulence calculations, an extrapolation of the present results to the Intel (sigma) machine gives an improvement factor close to 64 over the single-processor CRAY-2.

Automated urinalysis technique determines concentration of creatine and creatinine by colorimetry

Science.gov (United States)

Rho, J. H.

1967-01-01

Continuous urinalysis technique is useful in the study of muscle wastage in primates. Creatinine concentration in urine is determined in an aliquot mixture by a color reaction. Creatine is determined in a second aliquot by converting it to creatinine and measuring the difference in color intensity between the two aliquots.

Damage of actively cooled plasma facing components of magnetic confinement controlled fusion machines

Energy Technology Data Exchange (ETDEWEB)

Chevet, G. [Association Euratom-CEA, DSM/DRFC, CEA Cadarache, Saint-Paul-Lez-Durance (France)], E-mail: gaelle.chevet@cea.fr; Schlosser, J. [Association Euratom-CEA, DSM/DRFC, CEA Cadarache, Saint-Paul-Lez-Durance (France); Martin, E.; Herb, V.; Camus, G. [Universite Bordeaux 1, UMR 5801 (CNRS-SAFRAN-CEA-UB1), Laboratoire des Composites Thermostructuraux, F-33600 Pessac (France)

2009-03-31

Plasma facing components (PFCs) of magnetic fusion machines have high manufactured residual stresses and have to withstand important stress ranges during operation. These actively cooled PFCs have a carbon fibre composite (CFC) armour and a copper alloy heat sink. Cracks mainly appear in the CFC near the composite/copper interface. In order to analyse damage mechanisms, it is important to well simulate the damage mechanisms both of the CFC and the CFC/Cu interface. This study focuses on the mechanical behaviour of the N11 material for which the scalar ONERA damage model was used. The damage parameters of this model were identified by similarity to a neighbour material, which was extensively analysed, according to the few characterization test results available for the N11. The finite elements calculations predict a high level of damage of the CFC at the interface zone explaining the encountered difficulties in the PFCs fabrication. These results suggest that the damage state of the CFC cells is correlated with a conductivity decrease to explain the temperature increase of the armour surface under fatigue heat load.

Damage of actively cooled plasma facing components of magnetic confinement controlled fusion machines

Science.gov (United States)

Chevet, G.; Schlosser, J.; Martin, E.; Herb, V.; Camus, G.

2009-03-01

Plasma facing components (PFCs) of magnetic fusion machines have high manufactured residual stresses and have to withstand important stress ranges during operation. These actively cooled PFCs have a carbon fibre composite (CFC) armour and a copper alloy heat sink. Cracks mainly appear in the CFC near the composite/copper interface. In order to analyse damage mechanisms, it is important to well simulate the damage mechanisms both of the CFC and the CFC/Cu interface. This study focuses on the mechanical behaviour of the N11 material for which the scalar ONERA damage model was used. The damage parameters of this model were identified by similarity to a neighbour material, which was extensively analysed, according to the few characterization test results available for the N11. The finite elements calculations predict a high level of damage of the CFC at the interface zone explaining the encountered difficulties in the PFCs fabrication. These results suggest that the damage state of the CFC cells is correlated with a conductivity decrease to explain the temperature increase of the armour surface under fatigue heat load.

Damage of actively cooled plasma facing components of magnetic confinement controlled fusion machines

International Nuclear Information System (INIS)

Chevet, G.; Schlosser, J.; Martin, E.; Herb, V.; Camus, G.

2009-01-01

Plasma facing components (PFCs) of magnetic fusion machines have high manufactured residual stresses and have to withstand important stress ranges during operation. These actively cooled PFCs have a carbon fibre composite (CFC) armour and a copper alloy heat sink. Cracks mainly appear in the CFC near the composite/copper interface. In order to analyse damage mechanisms, it is important to well simulate the damage mechanisms both of the CFC and the CFC/Cu interface. This study focuses on the mechanical behaviour of the N11 material for which the scalar ONERA damage model was used. The damage parameters of this model were identified by similarity to a neighbour material, which was extensively analysed, according to the few characterization test results available for the N11. The finite elements calculations predict a high level of damage of the CFC at the interface zone explaining the encountered difficulties in the PFCs fabrication. These results suggest that the damage state of the CFC cells is correlated with a conductivity decrease to explain the temperature increase of the armour surface under fatigue heat load

Skill execution and sleep deprivation: effects of acute caffeine or creatine supplementation - a randomized placebo-controlled trial

Directory of Open Access Journals (Sweden)

Kilduff Liam P

2011-02-01

Full Text Available Abstract Background We investigated the effects of sleep deprivation with or without acute supplementation of caffeine or creatine on the execution of a repeated rugby passing skill. Method Ten elite rugby players completed 10 trials on a simple rugby passing skill test (20 repeats per trial, following a period of familiarisation. The players had between 7-9 h sleep on 5 of these trials and between 3-5 h sleep (deprivation on the other 5. At a time of 1.5 h before each trial, they undertook administration of either: placebo tablets, 50 or 100 mg/kg creatine, 1 or 5 mg/kg caffeine. Saliva was collected before each trial and assayed for salivary free cortisol and testosterone. Results Sleep deprivation with placebo application resulted in a significant fall in skill performance accuracy on both the dominant and non-dominant passing sides (p Conclusion Acute sleep deprivation affects performance of a simple repeat skill in elite athletes and this was ameliorated by a single dose of either caffeine or creatine. Acute creatine use may help to alleviate decrements in skill performance in situations of sleep deprivation, such as transmeridian travel, and caffeine at low doses appears as efficacious as higher doses, at alleviating sleep deprivation deficits in athletes with a history of low caffeine use. Both options are without the side effects of higher dose caffeine use.

Plasma Stability in Magnetic Mirror Machine with Stabilizing Rods; Stabilite du Plasma dans une Machine a Miroirs Magnetiques avec Barreaux de Stabilisation; Ustojchivost' plazmy v probkotrone so stabiliziruyushchimi sterzhnyami; Estabilidad del Plasma en una Trampa de Espejos con Barras Estabilizadoras

Energy Technology Data Exchange (ETDEWEB)

Trubnikov, B. A. [Institut Atomnoj Ehnergii Im. I.V. Kurchatova, Moskva, SSSR (Russian Federation)

1966-04-15

The well-known criterion {delta}{integral} Script-Small-L / B < 0 is generalized for arbitrary axially-asymmetric fields. For this purpose it must be presented as {integral}({delta}B/B{sup 2}) (P{sub 0} + P{sub Up-Tack }) d Script-Small-L > 0; here {delta}B = s x {Delta}B is the increase of the magnitude of the field on the adjacent (external) line of force, where s Up-Tack B. This criterion is applied to plasma stability in a magnetic mirror machine with stabilizing rods. The field near the axis is described by the scalar potential {psi} = {integral} B{sub 0} (z) dz - B{sub 0}{sup 1} (z) r 2/4 + g (z) r{sup n} cos n{phi} while for the field on the axis itself we accept the parabolic approximation B{sub 0}(z) = B{sub 0}{sup 0} (l + z{sup 2} /1{sup 2}). If 2n rods each with current J are located on a circle of radius a, then, for r{sub 0}/ Script-Small-L << 1 we can give the stability criterion such a form that in it remain only the parameters {alpha} = 4nJ Script-Small-L r{sub 0}{sup n-2}/ca{sup n} B{sup 0}{sub 0} and x = z{sub max}/ Script-Small-L , where z{sub max} is the farthest point of particle reflection (z = 0 is the central plane of the magnetic mirror machine). Two particle distributions are discussed: the Maxwellian distribution with the cut-out cone, and the single-valued distributions of v{sup 2} and J = v{sup 2}{sub Up-Tack }/B. Stability appears for {alpha} > (n-1)- Vulgar-Fraction-One-Half ; the particles with small longitudinal velocities (V{sub 0} --> 0) stabilize first; then, as {alpha} increases, those having ever more distant x. The limit, {sup {alpha}}lim = (n-1){sup Vulgar-Fraction-One-Half} , has a simple physical meaning and corresponds to the condition {Delta} Divides B Divides > 0 at z = 0. In this article, systems with 4 and 6 stabilizing rods are discussed in detail. The calculated results for the 6-rod system are in good agreement with the experiments of Ioffe and collaborators, who observed the appearance of a stabilized plasma in the

Preparation of sup 125 I-creatine phosphokinase-MM

Energy Technology Data Exchange (ETDEWEB)

Jingxian, Su; Jingmin, Ma [Academia Sinica, Beijing, BJ (China). Inst. of Atomic Energy

1988-09-01

{sup 125}I-creatine phosphokinase-MM ({sup 125}I-CPK-MM) was prepared by {sup 125}I-labelled Bolton-Hunter reagent (HPNS). Iodinating conditions of HPNS and its conjugation to protein were studied. {sup 125}I-CPK-MM with immune activity was obtained and used to establish the {sup 125}I-CPK-MM radioimmunoassay method by the General Hospital of PLA. {sup 125}I-CPK-MM in PBS-G solution containing 0.015 mol/l ethyl mercaptan at 4-10 deg C can be used for one month.

Is Long Term Creatine and Glutamine Supplementation Effective in Enhancing Physical Performance of Military Police Officers?

Directory of Open Access Journals (Sweden)

Lázaro da Silveira Celismar

2014-12-01

Full Text Available The objective of this study was to analyze the effect of supplementation with creatine and glutamine on physical fitness of military police officers. Therefore, an experimental double blind study was developed, with the final sample composed by 32 men randomly distributed into three groups: a group supplemented with creatine (n=10, glutamine (n=10 and a placebo group (n=12 and evaluated in three distinct moments, in an interval of three months (T1, T2 and T3. The physical training had a weekly frequency of 5 sessions x 90 min, including strength exercises, local muscular resistance, flexibility and both aerobic and anaerobic capacity. After analyzing the effect of time, group and interaction (group x time for measures that indicated the physical capabilities of the subjects, a significant effect of time for the entire variable was identified (p0,05. In face of the results it was concluded that supplementation with creatine and glutamine showed no ergogenic effect on physical performance in military police officers.

Influence of Arm-cranking on Changes in Plasma CK Activity after High Force Eccentric Exercise of the Elbow Flexors

OpenAIRE

Kosaka, Kazunori; Sakamoto, Kei; Newton, Mike

2002-01-01

NOSAKA, K., SAKAMOTO, K. and NEWTON, M., Influence of Armcranking on Changes in Plasma CK Activlty after High Force Eccentric Exerclse of the Elbow Flexours. Abv. Exerc. Sports Physiol., Vol.8, No.2 pp.45-50, 2002. It was hypothesized that the time course of changes in plasma creatine kinase(CK) activity following eccentrie exercise was influenced by rhythmical muscle contractions performned after eccentric exercise. This study examined whether arm-cranking (AC) alters the time course of chan...

Heat-Assisted Machining for Material Removal Improvement

Science.gov (United States)

Mohd Hadzley, A. B.; Hafiz, S. Muhammad; Azahar, W.; Izamshah, R.; Mohd Shahir, K.; Abu, A.

2015-09-01

Heat assisted machining (HAM) is a process where an intense heat source is used to locally soften the workpiece material before machined by high speed cutting tool. In this paper, an HAM machine is developed by modification of small CNC machine with the addition of special jig to hold the heat sources in front of the machine spindle. Preliminary experiment to evaluate the capability of HAM machine to produce groove formation for slotting process was conducted. A block AISI D2 tool steel with100mm (width) × 100mm (length) × 20mm (height) size has been cut by plasma heating with different setting of arc current, feed rate and air pressure. Their effect has been analyzed based on distance of cut (DOC).Experimental results demonstrated the most significant factor that contributed to the DOC is arc current, followed by the feed rate and air pressure. HAM improves the slotting process of AISI D2 by increasing distance of cut due to initial cutting groove that formed during thermal melting and pressurized air from the heat source.

Survey of mirror machine reactors

International Nuclear Information System (INIS)

Condit, W.C.

1978-01-01

The Magnetic Mirror Fusion Program is one of the two main-line fusion efforts in the United States. Starting from the simple axisymmetric mirror concept in the 1950's, the program has successfully overcome gross flute-type instabilities (using minimum-B magnetic fields), and the most serious of the micro-instabilities which plagued it (the drift-cyclotron loss-cone mode). Dense plasmas approaching the temperature range of interest for fusion have been created (n/sub p/ = 10 14 /cc at 10 to 12 keV). At the same time, rather extensive conceptual design studies of possible mirror configurations have led to three principle designs of interest: the standard mirror fission-fusion hybrid, tandem mirror, and the field-reversed mirror. The lectures will discuss these three concepts in turn. There will be no discussion of diagnostics for the mirror machine in these lectures, but typical plasma parameters will be given for each type of machine, and the diagnostic requirements will be apparent. In a working fusion reactor, diagnostics will be required for operational control, and remarks will be made on this subject

Nondispersive x-ray diagnostics of short lived plasmas

International Nuclear Information System (INIS)

Day, R.H.

1983-01-01

In this NATO Advanced Study Institute, we have discussed in detail the diagnosis of many pulse power machine properties, including their electrical behavior, grounding and shielding, and related data acquisition techniques. The purpose for many of these machines is to create high temperature/high density plasmas and, therefore, the subsequent behavior of these plasmas is of critical concern. The energy density of these plasmas is such that they will naturally radiate in the x-ray regime and thus the diagnosis of their x-ray emission is a crucial measurement of the entire system performance. In this lecture, I describe the general techniques used to perform nondispersive x-ray diagnostics of these short lived plasmas

Atmospheric-pressure plasma technology

International Nuclear Information System (INIS)

Kogelschatz, U

2004-01-01

Major industrial plasma processes operating close to atmospheric pressure are discussed. Applications of thermal plasmas include electric arc furnaces and plasma torches for generation of powders, for spraying refractory materials, for cutting and welding and for destruction of hazardous waste. Other applications include miniature circuit breakers and electrical discharge machining. Non-equilibrium cold plasmas at atmospheric pressure are obtained in corona discharges used in electrostatic precipitators and in dielectric-barrier discharges used for generation of ozone, for pollution control and for surface treatment. More recent applications include UV excimer lamps, mercury-free fluorescent lamps and flat plasma displays

Performance of a plasma fluid code on the Intel parallel computers

International Nuclear Information System (INIS)

Lynch, V.E.; Carreras, B.A.; Drake, J.B.; Leboeuf, J.N.; Liewer, P.

1992-01-01

One approach to improving the real-time efficiency of plasma turbulence calculations is to use a parallel algorithm. A parallel algorithm for plasma turbulence calculations was tested on the Intel iPSC/860 hypercube and the Touchtone Delta machine. Using the 128 processors of the Intel iPSC/860 hypercube, a factor of 5 improvement over a single-processor CRAY-2 is obtained. For the Touchtone Delta machine, the corresponding improvement factor is 16. For plasma edge turbulence calculations, an extrapolation of the present results to the Intel (sigma) machine gives an improvement factor close to 64 over the single-processor CRAY-2. 12 refs

Chromatographic separation and continuously referenced, on-line monitoring of creatine kinase isoenzymes by use of an immobilized-enzyme microreactor

International Nuclear Information System (INIS)

Denton, M.S.; Bostick, W.D.; Dinsmore, S.R.; Mrochek, J.E.

1978-01-01

We describe a new concept in continuously referenced monitoring of the isoenzyme activities of creatine kinase (EC 2.7.3.2) after liquid-chromatographic separation. After separation on a diethylaminoethyl-Sephacel column, the three isoenzymes of creatine kinase undergo a series of upled enzyme reactions, ultimately resulting in the formation of ultraviolet-detectable NADPH. A major advantage of this detection system is the immobilized-enzyme microreactor (2 x 17 mm), which may be removed and stored refrigerated when not in use. A split-stream configuration allows self-blanking of endogenous ultraviolet-absorbing constituents in authentic sera samples, which would otherwise make definitive diagnosis and quantitation difficult or impossible. This detection system is applicable to the automated analysis of creatine kinase isoenzymes in the clinical laboratory. 5 figures; 42 references

Design upgrading on Ignitor Machine

International Nuclear Information System (INIS)

Cucchiaro, A.; Coletti, A.; Bianchi, A.

2006-01-01

Ignitor is a high field compact machine conceived to achieve ignition in D-T plasma. The upgraded design of the Plasma Chamber (PC) and of the First Wall (FW) system consider the updated scenarios for IGNITOR vertical plasma disruption (VDE). The electromagnetic (EM) loads arising from halo currents and net horizontal force with the proper toroidal distribution have been envisaged. The dynamic elastic-plastic structural analysis of the PC has brought to a tayloring of the wall thickness such to reduce the displacements within the clearance with toroidal coil. A detailed 3D finite elements model has been developed in order to evaluate the electromagnetic loads on FW. The thermal loads arisen from plasma heat loads (peak value 1.8 MW/m 2 ) have been also considered. In any case the maximum calculated stresses are within the allowable limits. The relevant 3D virtual mockup software simulates the inside of the PC including the entire boom with end-effector. This allowed for the analysis of the boom kinematics to cover all positions with the various end-effectors to assess the Remote Handling task operations. The structural analysis of the IGNITOR machine Load Assembly has been performed taking into account the friction coefficients between the significant components. The non linear analysis takes into account for both the in-plane and the out-of-plane loads. The vertical plasma disruption conditions (VDE) result in bigger out-of-plane loads than the normal operating conditions. Keys of proper dimensions between the 30 o extension C-Clamps modules was adopted to assure structural stability. As far as the interlaminar shear stresses on toroidal field coils are concerned, the related safety factors are decreased respect to the normal operating conditions, but remaining around 2. (author)

Creatine Enhances Transdifferentiation of Bone Marrow Stromal Cell-Derived Neural Stem Cell Into GABAergic Neuron-Like Cells Characterized With Differential Gene Expression.

Science.gov (United States)

Darabi, Shahram; Tiraihi, Taki; Delshad, AliReza; Sadeghizadeh, Majid; Taheri, Taher; Hassoun, Hayder K

2017-04-01

Creatine was reported to induce bone marrow stromal cells (BMSC) into GABAergic neuron-like cells (GNLC). In a previous study, creatine was used as a single inducer for BMSC into GNLC with low yield. In this study, BMSC-derived neurospheres (NS) have been used in generating GABAergic phenotype. The BMSC were isolated from adult rats and used in generating neurospheres and used for producing neural stem cells (NSC). A combination of all-trans-retinoic acid (RA), the ciliary neurotrophic factor (CNTF), and creatine was used in order to improve the yield of GNLC. We also used other protocols for the transdifferentiation including RA alone; RA and creatine; RA and CNTF; and RA, CNTF, and creatine. The BMSC, NSC, and GNLC were characterized by specific markers. The activity of the GNLC was evaluated using FM1-43. The isolated BMSC expressed Oct4, fibronectin, and CD44. The NS were immunoreactive to nestin and SOX2, the NSC were immunoreactive to nestin, NF68 and NF160, while the GNLC were immunoreactive to GAD1/2, VGAT, GABA, and synaptophysin. Oct4 and c-MYC, pluripotency genes, were expressed in the BMSC, while SOX2 and c-MYC were expressed in the NSC. The activity of GNLC indicates that the synaptic vesicles were released upon stimulation. The conclusion is that the combination of RA, CNTF, and creatine induced differentiation of neurosphere-derived NSC into GNLC within 1 week. This protocol gives higher yield than the other protocols used in this study. The mechanism of induction was clearly associated with several differential pluripotent genes.

Langmuir probes for SPIDER (source for the production of ions of deuterium extracted from radio frequency plasma) experiment: Tests in BATMAN (Bavarian test machine for negative ions)

Science.gov (United States)

Brombin, M.; Spolaore, M.; Serianni, G.; Pomaro, N.; Taliercio, C.; Palma, M. Dalla; Pasqualotto, R.; Schiesko, L.

2014-11-01

A prototype system of the Langmuir probes for SPIDER (Source for the production of Ions of Deuterium Extracted from RF plasma) was manufactured and experimentally qualified. The diagnostic was operated in RF (Radio Frequency) plasmas with cesium evaporation on the BATMAN (BAvarian Test MAchine for Negative ions) test facility, which can provide plasma conditions as expected in the SPIDER source. A RF passive compensation circuit was realised to operate the Langmuir probes in RF plasmas. The sensors' holder, designed to better simulate the bias plate conditions in SPIDER, was exposed to a severe experimental campaign in BATMAN with cesium evaporation. No detrimental effect on the diagnostic due to cesium evaporation was found during the exposure to the BATMAN plasma and in particular the insulation of the electrodes was preserved. The paper presents the system prototype, the RF compensation circuit, the acquisition system (as foreseen in SPIDER), and the results obtained during the experimental campaigns.

Langmuir probes for SPIDER (source for the production of ions of deuterium extracted from radio frequency plasma) experiment: Tests in BATMAN (Bavarian test machine for negative ions)

International Nuclear Information System (INIS)

Brombin, M.; Spolaore, M.; Serianni, G.; Pomaro, N.; Taliercio, C.; Palma, M. Dalla; Pasqualotto, R.; Schiesko, L.

2014-01-01

A prototype system of the Langmuir probes for SPIDER (Source for the production of Ions of Deuterium Extracted from RF plasma) was manufactured and experimentally qualified. The diagnostic was operated in RF (Radio Frequency) plasmas with cesium evaporation on the BATMAN (BAvarian Test MAchine for Negative ions) test facility, which can provide plasma conditions as expected in the SPIDER source. A RF passive compensation circuit was realised to operate the Langmuir probes in RF plasmas. The sensors’ holder, designed to better simulate the bias plate conditions in SPIDER, was exposed to a severe experimental campaign in BATMAN with cesium evaporation. No detrimental effect on the diagnostic due to cesium evaporation was found during the exposure to the BATMAN plasma and in particular the insulation of the electrodes was preserved. The paper presents the system prototype, the RF compensation circuit, the acquisition system (as foreseen in SPIDER), and the results obtained during the experimental campaigns

Histochemical demonstration of creatine kinase activity using polyvinyl alcohol and auxiliary enzymes

NARCIS (Netherlands)

Frederiks, W. M.; Marx, F.; van Noorden, C. J.

1987-01-01

Creatine kinase activity (EC 2.7.3.2.) has been demonstrated in myocardium and skeletal muscle from rats by a method based on the incubation of cryostat sections with a polyvinyl alcohol-containing medium and the use of auxiliary enzymes. Hexokinase and glucose-6-phosphate dehydrogenase were spread

Momentum transport studies from multi-machine comparisons

International Nuclear Information System (INIS)

Yoshida, M.; Kamada, Y.; Sakamoto, Y.; Kaye, S.; Solomon, W.; Bell, R.E.; Rice, J.; Podpaly, Y.; Reinke, M.L.; Tala, T.; Salmi, A.; Burrell, K.H.; Ferreira, J.; McDonald, D.; Mantica, P.

2012-01-01

A database of toroidal momentum transport on five tokamaks, Alcator C-Mod, DIII-D, JET, NSTX and JT-60U, has been constructed under a wide range of conditions in order to understand the characteristics of toroidal momentum transport coefficients, namely the toroidal momentum diffusivity (χ φ ) and the pinch velocity (V pinch ). Through an inter-machine comparison, the similarities and differences in the properties of χ φ and V pinch among the machines have been clarified. Parametric dependences of these momentum transport coefficients have been investigated over a wide range of plasma parameters taking advantage of the different operation regimes in machines. The approach offers insights into the parametric dependences as follows. The toroidal momentum diffusivity (χ φ ) generally increases with increasing heat diffusivity (χ i ). The correlation is observed over a wide range of χ φ , covering roughly two orders of magnitude, and within each of the machines over the whole radius. Through the inter-machine comparison, it is found that χ φ becomes larger in the outer region of the plasma. Also observed is a general trend for V pinch in tokamaks; the inward pinch velocity (−V pinch ) increases with increasing χ φ . The results that are commonly observed in machines will support a toroidal rotation prediction in future devices. On the other hand, differences among machines have been observed. The toroidal momentum diffusivity, χ φ , is larger than or equal to χ i in JET and JT-60U; on the other hand, χ φ is smaller than or equal to χ i in NSTX, DIII-D and Alcator C-Mod. In DIII-D, the ratio −RV pinch /χ φ at r/a = 0.5–0.6 is about 2, which is small compared with that in other tokamaks (−RV pinch /χ φ ≈ 5). Based on these different observations, parametric dependences of χ φ /χ i , RV pinch /χ φ and χ φ have been investigated in H-mode plasmas. Across the dataset from all machines, the ratio χ φ /χ i tends to be larger in low �

Effects of creatine supplementation on high-intensity intermittent exercise: discrepancies and methodological appraisals

Directory of Open Access Journals (Sweden)

Patrícia Chackur Brum

2008-04-01

Full Text Available After a brief review of the literature on the effects of creatine supplementation on high-intensity intermittent exercise performance, the main aim of this study was to discuss methodological differences between studies which could explain the discrepancies observed in the literature. The effects of creatine supplementation on high-intensity intermittent exercise performance have been investigated in depth. Although the results of much research demonstrates the effi cacy of this supplement, there is just as much evidence that does not support this ergogenic effect. The explanation for this divergence appears to be multifactorial, although it is always linked to methodological characteristics. Study design (crossover or parallel groups, individual variability of muscular creatine content, chronic high meat intake, sample size, exercise protocol characteristics (body weight dependence and time between series, and gender and age all differ between studies and are potentially the variables responsible, to differing extents, for the discrepancies observed in the literature. Studies involving young males, with parallel group design, adequate statistical power, control of the incorporation of creatine into muscles, food intake assessment and intermittent exercise protocols in which performance is independent of body weight and with rest-recovery intervals of 1 to 6 minutes, usually produce positive results. The many methodological factors which can contribute to divergence on the ergogenic effects of creatine should be considered in futures studies, as well as when prescribing creatine supplementation. Resumo Após breve revisão da literatura existente acerca dos efeitos da suplementação de creatina no rendimento em atividades intermitentes de alta intensidade, o objetivo principal dessa revisão foi discutir diferenças metodológicas dos estudos que possam explicar a divergência encontrada na literatura. Os efeitos da suplementação de creatina

The Creatine Transporter Gene Paralogous at 16p11.2 Is Expressed in Human Brain

Directory of Open Access Journals (Sweden)

Nadia Bayou

2008-01-01

We report on the clinical, cytogenetic, and molecular findings in a boy with autism carrying a de novo translocation t(7;16(p22.1;p11.2. The chromosome 16 breakpoint disrupts the paralogous SLC6A8 gene also called SLC6A10 or CT2. Predicted translation of exons and RT-PCR analysis reveal specific expression of the creatine transporter paralogous in testis and brain. Several studies reported on the role of X-linked creatine transporter mutations in individuals with mental retardation, with or without autism. The existence of disruption in SLC6A8 paralogous gene associated with idiopathic autism suggests that this gene may be involved in the autistic phenotype in our patient.

Evaluation of plasma chemistry and haematological studies on chickens infected with Eimeria tenella and E acervulina.

Science.gov (United States)

Fukata, T; Komba, Y; Sasai, K; Baba, E; Arakawa, A

1997-07-12

Plasma chemistry and haematological studies were conducted on chickens with coccidiosis. Male White Leghorn chickens, of two weeks old, were inoculated with 5 x 10(4) Eimeria tenella sporulated oocysts or with 1 x 10(6) E acervulina sporulated oocysts. Blood samples were taken four, seven and 11 days after inoculation. A wet chemistry system was applied to measure the plasma activities of aspartate aminotransferase, alanine aminotransferase, alkaline phosphatase, gamma glutamyltransferase, creatine kinase, amylase and lactate dehydrogenase and the concentrations of creatine, total bilirubin, urate, total cholesterol, total protein, albumin, glucose and triglycerides. A dry chemistry system was applied to measure sodium, potassium, chloride and calcium. The number of red blood cells and packed cell volume were determined by a micro cell counter and blood pH was measured with a blood gas analyser. The erythrocyte count, packed cell volume, sodium and chloride levels in the chickens infected with E tenella were significantly (P < 0.05) lower than those of the uninfected controls. The significant decrease in blood pH of the chickens infected with E acervulina suggests malabsorption associated with duodenal lesions induced by the infection.

Measurements of wave-particle interaction in a single-ended Q machine

DEFF Research Database (Denmark)

Andersen, S.A.; Christoffersen, G.B.; Jensen, Vagn Orla

1971-01-01

. Experimentally, short density pulses are generated in the plasma in a single-ended Q machine by application of electrical square pulses to a grid immersed in the plasma column. The perturbed ion velocity distribution function in the density pulse is measured by means of an electrostatic energy analyzer...

Control of creatine metabolism by HIF is an endogenous mechanism of barrier regulation in colitis.

Science.gov (United States)

Glover, Louise E; Bowers, Brittelle E; Saeedi, Bejan; Ehrentraut, Stefan F; Campbell, Eric L; Bayless, Amanda J; Dobrinskikh, Evgenia; Kendrick, Agnieszka A; Kelly, Caleb J; Burgess, Adrianne; Miller, Lauren; Kominsky, Douglas J; Jedlicka, Paul; Colgan, Sean P

2013-12-03

Mucosal surfaces of the lower gastrointestinal tract are subject to frequent, pronounced fluctuations in oxygen tension, particularly during inflammation. Adaptive responses to hypoxia are orchestrated largely by the hypoxia-inducible transcription factors (HIFs). As HIF-1α and HIF-2α are coexpressed in mucosal epithelia that constitute the barrier between the lumen and the underlying immune milieu, we sought to define the discrete contribution of HIF-1 and HIF-2 transactivation pathways to intestinal epithelial cell homeostasis. The present study identifies creatine kinases (CKs), key metabolic enzymes for rapid ATP generation via the phosphocreatine-creatine kinase (PCr/CK) system, as a unique gene family that is coordinately regulated by HIF. Cytosolic CKs are expressed in a HIF-2-dependent manner in vitro and localize to apical intestinal epithelial cell adherens junctions, where they are critical for junction assembly and epithelial integrity. Supplementation with dietary creatine markedly ameliorated both disease severity and inflammatory responses in colitis models. Further, enzymes of the PCr/CK metabolic shuttle demonstrate dysregulated mucosal expression in a subset of ulcerative colitis and Crohn disease patients. These findings establish a role for HIF-regulated CK in epithelial homeostasis and reveal a fundamental link between cellular bioenergetics and mucosal barrier.

The effects of a high dosage of creatine and caffeine supplementation on the lean body mass composition of rats submitted to vertical jumping training

Directory of Open Access Journals (Sweden)

Carneiro-Junior Miguel A

2011-03-01

Full Text Available Abstract Background The influences of creatine and caffeine supplementation associated with power exercise on lean body mass (LBM composition are not clear. The purpose of this research was to determine whether supplementation with high doses of creatine and caffeine, either solely or combined, affects the LBM composition of rats submitted to vertical jumping training. Methods Male Wistar rats were randomly divided into 8 groups: Sedentary (S or Exercised (E [placebo (Pl, creatine (Cr, caffeine (Caf or creatine plus caffeine (CrCaf]. The supplemented groups received creatine [load: 0.430 g/kg of body weight (BW for 7 days; and maintenance: 0.143 g/kg of BW for 35 days], caffeine (15 mg/kg of BW for 42 days or creatine plus caffeine. The exercised groups underwent a vertical jump training regime (load: 20 - 50% of BW, 4 sets of 10 jumps interspersed with 1 min resting intervals, 5 days/wk, for 6 weeks. LBM composition was evaluated by portions of water, protein and fat in the rat carcass. Data were submitted to ANOVA followed by the Tukey post hoc test and Student's t test. Results Exercised animals presented a lower carcass weight (10.9%; P = 0.01, as compared to sedentary animals. However, no effect of supplementation was observed on carcass weight (P > 0.05. There were no significant differences among the groups (P > 0.05 for percentage of water in the carcass. The percentage of fat in the group SCr was higher than in the groups SCaf and ECr (P Conclusions High combined doses of creatine and caffeine does not affect the LBM composition of either sedentary or exercised rats, however, caffeine supplementation alone reduces the percentage of fat. Vertical jumping training increases the percentages of water and protein and reduces the fat percentage in rats.

Changes in the level of urea, creatine and creatinine in the liver and serum of irradiated rats

International Nuclear Information System (INIS)

El Kashef, H.S.; Saada, H.N.

1991-01-01

This study aims to compare between the susceptibility of two tissues (liver and serum) toγ-radiation with respect to some protein end-products; namely urea, creatine and creatinine. The results indicated that in control rat liver, the concentration of urea, creatine and creatinine ranged between 262-266, 106-108 and 18.86-19.48 μg/g fresh tissue, respectively. In blood serum, the concentration of these end-products were 327-383, 94-97 and 12.36-12.51μg/ml blood serum. Whole body -irradiation at dose 5.5 Gy caused significant changes in the levels of both urea and creatine in the blood serum on the 7th and 14th post irradiation days, while the level of creatinine was not altered. As for the liver of whole body γ -irradiated rats, significant changes were observed in the content of urea at the all post-irradiation days except at the 3 rd day. The creatinine content of the liver was significantly decreased on the 3 rd, 14th and 21st days after irradiation. Similar decrease was noticed in the content of creatine, but on the 7th day, significant increase was observed. The variation in the studied parameters started early in the liver and lated longer, but it started later and lasted shorter in the serum of irradiated rats. It could be suggested that the liver of irradiated rats is more sensitive to the radiation dose 5.5 Gy than the blood.1 fig.,2 tab

Creatine in combination with resistance training and improvement in muscle strength: evaluation of a health claim pursuant to Article 13(5) of Regulation (EC) No 1924/2006

DEFF Research Database (Denmark)

Sjödin, Anders Mikael

2016-01-01

on the scientific substantiation of a health claim related to creatine in combination with resistance training and improvement in muscle strength. The Panel considers that the food constituent, creatine, which is the subject of the health claim, is sufficiently characterised. The Panel considers that improvement...... substantiation of the claim. In weighing the evidence the Panel took into account that, overall, the human intervention studies submitted provide evidence for an effect of creatine, consumed at doses of at least 3 g/day in combination with regular resistance training (three times per week for several weeks......) of moderate intensity, on muscle strength in adults over the age of 55, while no such effect was observed when similar doses of creatine on a weekly basis were given on training days only (three times per week). The Panel also took into account the plausible mechanism by which daily consumption of creatine...

FTIR Imaging of Brain Tissue Reveals Crystalline Creatine Deposits Are an ex Vivo Marker of Localized Ischemia during Murine Cerebral Malaria: General Implications for Disease Neurochemistry

Science.gov (United States)

2012-01-01

Phosphocreatine is a major cellular source of high energy phosphates, which is crucial to maintain cell viability under conditions of impaired metabolic states, such as decreased oxygen and energy availability (i.e., ischemia). Many methods exist for the bulk analysis of phosphocreatine and its dephosphorylated product creatine; however, no method exists to image the distribution of creatine or phosphocreatine at the cellular level. In this study, Fourier transform infrared (FTIR) spectroscopic imaging has revealed the ex vivo development of creatine microdeposits in situ in the brain region most affected by the disease, the cerebellum of cerebral malaria (CM) diseased mice; however, such deposits were also observed at significantly lower levels in the brains of control mice and mice with severe malaria. In addition, the number of deposits was observed to increase in a time-dependent manner during dehydration post tissue cutting. This challenges the hypotheses in recent reports of FTIR spectroscopic imaging where creatine microdeposits found in situ within thin sections from epileptic, Alzheimer’s (AD), and amlyoid lateral sclerosis (ALS) diseased brains were proposed to be disease specific markers and/or postulated to contribute to the brain pathogenesis. As such, a detailed investigation was undertaken, which has established that the creatine microdeposits exist as the highly soluble HCl salt or zwitterion and are an ex-vivo tissue processing artifact and, hence, have no effect on disease pathogenesis. They occur as a result of creatine crystallization during dehydration (i.e., air-drying) of thin sections of brain tissue. As ischemia and decreased aerobic (oxidative metabolism) are common to many brain disorders, regions of elevated creatine-to-phosphocreatine ratio are likely to promote crystal formation during tissue dehydration (due to the lower water solubility of creatine relative to phosphocreatine). The results of this study have demonstrated that

Simultaneous quantification of porcine myocardial adenine nucleotides and creatine phosphate by ion-pair reverse-phase high-performance liquid chromatography

International Nuclear Information System (INIS)

Cordis, G.A.; Das, D.K.

1987-01-01

In order to follow the energy metabolism and the levels of high-energy phosphate compounds in porcine myocardium subjected to ischemic insult, it was necessary to develop a high-performance liquid chromatography (HPLC) method where creatine phosphate (CP) and the adenine nucleotides could be measured simultaneously in a single run. Currently available ion-pair reverse-phase HPLC methods require a separate injection with a change in wavelength and mobile phase in order to measure the creatine phosphate, while baseline separation of AMP is lacking. The ion-exchange HPLC method includes a simultaneous determination, but the baseline drifts due to the gradient and baseline separation of AMP is not achieved. In the following ion-pair reverse-phase HPLC method, simultaneous measurements of porcine myocardial adenine nucleotides and creatine phosphate were achieved along with a stable baseline and homogeneous baseline separation of each measured compound, allowing accurate quantification

Determination of total creatine kinase activity in blood serum using an amperometric biosensor based on glucose oxidase and hexokinase.

Science.gov (United States)

Kucherenko, I S; Soldatkin, O O; Lagarde, F; Jaffrezic-Renault, N; Dzyadevych, S V; Soldatkin, A P

2015-11-01

Creatine kinase (CK: adenosine-5-triphosphate-creatine phosphotransferase) is an important enzyme of muscle cells; the presence of a large amount of the enzyme in blood serum is a biomarker of muscular injuries, such as acute myocardial infarction. This work describes a bi-enzyme (glucose oxidase and hexokinase based) biosensor for rapid and convenient determination of CK activity by measuring the rate of ATP production by this enzyme. Simultaneously the biosensor determines glucose concentration in the sample. Platinum disk electrodes were used as amperometric transducers. Glucose oxidase and hexokinase were co-immobilized via cross-linking with BSA by glutaraldehyde and served as a biorecognition element of the biosensor. The biosensor work at different concentrations of CK substrates (ADP and creatine phosphate) was investigated; optimal concentration of ADP was 1mM, and creatine phosphate - 10 mM. The reproducibility of the biosensor responses to glucose, ATP and CK during a day was tested (relative standard deviation of 15 responses to glucose was 2%, to ATP - 6%, to CK - 7-18% depending on concentration of the CK). Total time of CK analysis was 10 min. The measurements of creatine kinase in blood serum samples were carried out (at 20-fold sample dilution). Twentyfold dilution of serum samples was chosen as optimal for CK determination. The biosensor could distinguish healthy and ill people and evaluate the level of CK increase. Thus, the biosensor can be used as a test-system for CK analysis in blood serum or serve as a component of multibiosensors for determination of important blood substances. Determination of activity of other kinases by the developed biosensor is also possible for research purposes. Copyright © 2015 Elsevier B.V. All rights reserved.

Plasma heating by radio frequency in the LISA linear machine

International Nuclear Information System (INIS)

Cunha Raposo, C. da.

1985-05-01

The characteristics of an experimental apparatus to produce helium plasma by radio frequency and to study its behavior when confined by a magnetic field with mirrors is shown. The plasma was produced by a microwave source of 2.45 GHz and 800 Watts, operating in steady and pulsed state. The plasma parameters were studied as a function of an external magnetic field, for large and small resonance regions. The axial and radial magnetic fields were mapped for each region in order to verify the spatial distribution, particle orbits, and energy confinement time according to the energy balance equation. As a consequence of the influence of the radio frequency (RF) voltage in the plasma the Bohm theory of plasma prob was modified. The diagnostic was done with plane movable electrostatic probe, Hall probe, magnetic probe, diamagnetic coil and spectrography. (Author) [pt

Frequency-domain lifetime fluorometry of double-labeled creatine kinase.

Science.gov (United States)

Gregor, M; Kubala, M; Amler, E; Mejsnar, J

2003-01-01

Myofibril-bound creatine kinase EC 2.7.3.2 (CK), a key enzyme of muscle energy metabolism, has been selected for studies of conformational changes that underlie the cellular control of enzyme activity. For fluorescence spectroscopy measurements, the CK molecule was double-labeled with IAF (5-iodoacetamidofluorescein) and ErITC (erythrosin 5'-isothiocyanate). Measurement of fluorescence resonance energy transfer (FRET) from fluorescein to erythrosin was used to obtain information about the donor-acceptor pair distance. Frequency-domain lifetime measurements evaluate the donor-acceptor distance in the native CK molecule as 7.8 nm. The Förster radius equals 5.3 nm with the resolution range from 0.2 to 1.0 nm. Erythrosin-fluorescein labeling (EFL) was tested for artificial conformational changes of the CK molecule with high-salt concentration treatment. The transition distance, defined by His-97 and Cys-283 and derived from a 3D model equals 0.766 nm for the open (inactive) form and 0.277 nm for the closed (reactive) form of the CK molecule. In this way, the resolution range of the used spectroscopy method is significant, concerning the difference of 0.489 nm. Nevertheless, the CK enzyme activity, assessed by the hexokinase-coupled assay, was diminished down to 1 % of the activity of the native enzyme. EFL is suitable for description of conformational behavior implied from the regulation of creatine kinase. However, the observed inhibition restricts EFL to studies of conformational changes during natural catalytic activity.

Comparison of the eight weeks of supplementation Creatine and Glutamine consumption along with resistance exercise on the level of ALP in female mice

Directory of Open Access Journals (Sweden)

A eskandari

2015-11-01

Full Text Available Background and purpose: in recent years, in order to improve power, speed, the increase in the volume of the musculature, preventing sports injuries and maintain the muscle performance athletes use from different resistance exercises and food supplements. In this regard, present study has been conducted with the aim of comparison the influence of an 8 week period consumption of creatine (2 gr.kg-1.day-1 in 1st week and 0.48 gr.kg-1.day-1during 2nd to 8th weeks and glutamine (1 gr.kg-1.day-1 from first to eighth weeks along with resistance exercise on level of ALP of female mice. Materials and methods: This experimental study was done on 80 Small adult female mice of Surrey species (28 ± 5 gram. The animals were randomly divided into 8 groups of: resistance exercise, resistance exercise + creatine, resistance exercise + glutamine, resistance exercise + glutamine + creatine, creatine, glutamine, creatine + glutamine and control groups (N= 10. Resistance exercise (5 days a week was including: climbing (4 sets, 5 times repetition with two minutes rest between the sets from a ladder (with the height of one meter and including 26 steps and bearing 30 percent of the weight of the Mouse body (hanging from tail in the first week and the increasing it up to 200 percent of body weight till the last week of the experiment. During 48 hours after the last practice session of resistance exercise, the blood sample was taken and the the level of ALP has been measured. Findings:The results showed that the level of ALP enzyme in creatine + glutamine + resistance exercise groug had been increased in comparison with the control group (144.3 ± 15.86 in comparison with 234.7 ± 25.69 U.L-1 P < 0.05. Conclusion: The results of this research indicate Creatine and Glutamine supplementation consumption along with resistance exercise increases in the level of ALP enzyme in the liver of mice.

Production of a double-humped ion velocity distribution function in a single-ended Q-machine

DEFF Research Database (Denmark)

Andersen, S.A.; Jensen, Vagn Orla; Michelsen, Poul

1970-01-01

An experimental method of producing a double-humped velocity distribution function for the ions in a Q-machine is described. The method is based on charge exchange processes between neutral ceasium and the ions in a ceasium plasma.......An experimental method of producing a double-humped velocity distribution function for the ions in a Q-machine is described. The method is based on charge exchange processes between neutral ceasium and the ions in a ceasium plasma....

1H magnetic resonance spectroscopy of the brain in paediatrics: The diagnosis of creatine deficiencies

NARCIS (Netherlands)

Sijens, P.E.; Oudkerk, M.

2005-01-01

The diagnosis of creatine deficiencies, a paediatric application of magnetic resonance spectroscopy that has already become a diagnostic tool in clinical practice, is reviewed and illustrated with results from recent examinations

The effects of a high dosage of creatine and caffeine supplementation on the lean body mass composition of rats submitted to vertical jumping training.

Science.gov (United States)

Franco, Frederico Sc; Costa, Neuza Mb; Ferreira, Susana A; Carneiro-Junior, Miguel A; Natali, Antônio J

2011-03-01

The influences of creatine and caffeine supplementation associated with power exercise on lean body mass (LBM) composition are not clear. The purpose of this research was to determine whether supplementation with high doses of creatine and caffeine, either solely or combined, affects the LBM composition of rats submitted to vertical jumping training. Male Wistar rats were randomly divided into 8 groups: Sedentary (S) or Exercised (E) [placebo (Pl), creatine (Cr), caffeine (Caf) or creatine plus caffeine (CrCaf)]. The supplemented groups received creatine [load: 0.430 g/kg of body weight (BW) for 7 days; and maintenance: 0.143 g/kg of BW for 35 days], caffeine (15 mg/kg of BW for 42 days) or creatine plus caffeine. The exercised groups underwent a vertical jump training regime (load: 20 - 50% of BW, 4 sets of 10 jumps interspersed with 1 min resting intervals), 5 days/wk, for 6 weeks. LBM composition was evaluated by portions of water, protein and fat in the rat carcass. Data were submitted to ANOVA followed by the Tukey post hoc test and Student's t test. Exercised animals presented a lower carcass weight (10.9%; P = 0.01), as compared to sedentary animals. However, no effect of supplementation was observed on carcass weight (P > 0.05). There were no significant differences among the groups (P > 0.05) for percentage of water in the carcass. The percentage of fat in the group SCr was higher than in the groups SCaf and ECr (P < 0.05). A higher percentage of protein was observed in the groups EPl and ECaf when compared to the groups SPl and SCaf (P < 0.001). The percentage of fat in the carcass decreased (P < 0.001), while those of water and protein increased (P < 0.05) in exercised animals, compared to sedentary animals. Caffeine groups presented reduced percentage of fat when compared to creatine supplemented groups (P < 0.05). High combined doses of creatine and caffeine does not affect the LBM composition of either sedentary or exercised rats, however, caffeine

Machine performance and its effects on experiments in JT-60U

International Nuclear Information System (INIS)

Kondo, I.

1995-01-01

The operational results of JT-60U were reviewed in light of the strategy made at the design stage. The operational plan for better confinement shifted from that of low q to high poloidal beta plasma configuration with higher q value according to the revealed machine properties. Some technical and operational skills helped bring about the recent results out of the machine. (orig.)

Normal results of post-race thallium-201 myocardial perfusion imaging in marathon runners with elevated serum MB creatine kinase levels

International Nuclear Information System (INIS)

Siegel, A.J.; Silverman, L.M.; Holman, B.L.

1985-01-01

Elevated cardiac enzyme values in asymptomatic marathon runners after competition can arise from skeletal muscle through exertional rhabdomyolysis, silent injury to the myocardium, or a combined tissue source. Peak post-race levels of the MB isoenzyme of creatine kinase are similar to values in patients with acute myocardial infarction. Previously reported normal results of infarct-avid myocardial scintigraphy with technetium 99m pyrophosphate in runners after competition suggest a non-cardiac source but cannot exclude silent injury to the myocardium. Therefore, thallium 201 myocardial perfusion imaging was performed in runners immediately after competition together with determination of sequential cardiac enzyme levels. Among 15 runners tested, the average peak in serum MB creatine kinase 24 hours after the race was 128 IU/liter with a cumulative MB creatine kinase release of 117 IU/liter; these values are comparable to those in patients with acute transmural myocardial infarction. Thallium 201 myocardial scintigraphic results were normal in five runners randomly selected from those who volunteered for determination of sequential blood levels. It is concluded that elevations of serum MB creatine kinase in marathon runners arise from a skeletal muscle source and that thallium 201 myocardial scintigraphy is useful to assess runners for myocardial injury when clinical questions arise

A double-blind, placebo-controlled randomized trial of creatine for the cancer anorexia/weight loss syndrome (N02C4): an Alliance trial.

Science.gov (United States)

Jatoi, A; Steen, P D; Atherton, P J; Moore, D F; Rowland, K M; Le-Lindqwister, N A; Adonizio, C S; Jaslowski, A J; Sloan, J; Loprinzi, C

2017-08-01

Multiple pilot studies, including one in colorectal cancer patients, suggest that creatine, an amino acid derivative, augments muscle, improves strength, and thereby could palliate the cancer anorexia/weight loss syndrome. In this randomized, double-blind, placebo-controlled trial, incurable patients with this syndrome were assigned creatine (20 g/day load×5 days followed by 2 g/day orally) versus identical placebo. Patients were weighed once a week for 1 month and then monthly. Patients were also assessed over 1 month for appetite and quality of life (validated questionnaires), fist grip strength, body composition (bioelectrical impedance), and adverse events. The primary endpoint was 10% or greater weight gain from baseline during the first month. Within this combined cohort of 263 evaluable patients (134 received creatine and 129 placebo), only 3 gained ≥10% of their baseline weight by 1 month: two creatine-treated and the other placebo-exposed (P = 1.00). Questionnaire data on appetite, quality of life, and activities of daily living showed no statistically significant differences between groups. Similarly, no statistically significant differences between groups were observed for fist-grip strength or body composition. Rates and severity of adverse events were comparable between groups. Finally, a median survival of 230 and 239 days were observed in the creatine and placebo groups, respectively (P = 0.70). Creatine, as prescribed in this trial, had no effect on the cancer anorexia/weight loss syndrome. © The Author 2017. Published by Oxford University Press on behalf of the European Society for Medical Oncology. All rights reserved. For permissions, please email: journals.permissions@oup.com.

Design, fabrication, and testing of the PIACE-R1 machine

International Nuclear Information System (INIS)

Goto, S.; Uyama, T.; Yokota, T.; Takano, H.; Ohsaki, O.; Masuda, K.; Koyanagi, E.; Sanada, Y.

1979-01-01

The design, fabrication and testing of the coil and collector system for the PIACE-R1 (Plasma Injection and Compression Experiments-Race Track 1) are described in this paper. In particular, the eddy current analysis, collector insulation, and stress analysis for determining the coil configuration and arrangement are presented in detail. The purpose of the machine is to obtain thermonuclear plasmas. 5 refs

Comparison of Advanced Machine Learning Tools for Disruption Prediction and Disruption Studies

Czech Academy of Sciences Publication Activity Database

Odstrčil, Michal; Murari, A.; Mlynář, Jan

2013-01-01

Roč. 41, č. 7 (2013), s. 1751-1759 ISSN 0093-3813 R&D Projects: GA ČR GAP205/10/2055 Institutional support: RVO:61389021 Keywords : Learning Machines * Support Vector Machines * Neural Network * ASDEX Upgrade * JET * Disruption mitigation * Tokamaks * ITER Subject RIV: BL - Plasma and Gas Discharge Physics Impact factor: 0.950, year: 2013

Plasma focus system: Design, construction and experiments

International Nuclear Information System (INIS)

Alacakir, A.; Akguen, Y.; Boeluekdemir, A. S.

2007-01-01

The aim of this work is to construct a compact experimental system for fusion research. The design, construction and experiments of the 3 kJ Mather type plasma focus machine is described. This machine is established for neutron yield and fast neutron radiography by D-D reaction which is given by D + D→ 3 He (0.82 MeV) + n (2.45 MeV) . Investigation of the geometry of plasma focus machine in the presence of high voltage drive and vacuum system setup is shown. 108 neutron per pulse and 200 kA peak current is obtained for many shots. Scintillator screen for fast neutron imaging, sensitive to 2.45 MeV neutrons, is also manufactured in our labs. Structural neutron shielding computations for safety is also completed

Hematologic and plasma biochemical reference values in Indian peafowl (Pavo cristatus).

Science.gov (United States)

Samour, Jaime; Naldo, Jesus; Rahman, Habeeb; Sakkir, Mohammed

2010-06-01

Blood samples were collected from captive, adult, clinically normal Indian peafowl (Pavo cristatus) for hematologic and plasma biochemical analyses. Hematologic parameters investigated were total red blood cell count, hemoglobin, packed cell volume, fibrinogen, mean cell volume, mean cell hemoglobin, mean cell hemoglobin concentration, total white blood cell count, differential white blood cell count, and thrombocyte count. Plasma biochemical parameters investigated were alanine aminotransferase, alkaline phosphatase, amylase, aspartate aminotransferase, bile acids, total bilirubin, blood urea nitrogen, calcium, cholesterol, creatinine, creatine kinase, gamma glutamyltransferase, lactate dehydrogenase, glucose, iron, phosphorus, and uric acid, as well as plasma protein electrophoresis. Results were compared with values from studies done in houbara bustards (Chlamydotis undulata), kori bustards (Ardeotis kori), stone curlews (Burhinus oedicnemus), and taxonomically related species, including ring-necked pheasants (Phasianus colchicus), red-legged partridges (Alectoris rufa), Kashmir native fowl (Kashmirfavorella), and Bangladesh native, Fayoumi, and Assil fowl (Gallus domesticus).

Quantitative estimation of infarct size by simultaneous dual radionuclide single photon emission computed tomography: comparison with peak serum creatine kinase activity

International Nuclear Information System (INIS)

Kawaguchi, K.; Sone, T.; Tsuboi, H.; Sassa, H.; Okumura, K.; Hashimoto, H.; Ito, T.; Satake, T.

1991-01-01

To test the hypothesis that simultaneous dual energy single photon emission computed tomography (SPECT) with technetium-99m (99mTc) pyrophosphate and thallium-201 (201TI) can provide an accurate estimate of the size of myocardial infarction and to assess the correlation between infarct size and peak serum creatine kinase activity, 165 patients with acute myocardial infarction underwent SPECT 3.2 +/- 1.3 (SD) days after the onset of acute myocardial infarction. In the present study, the difference in the intensity of 99mTc-pyrophosphate accumulation was assumed to be attributable to difference in the volume of infarcted myocardium, and the infarct volume was corrected by the ratio of the myocardial activity to the osseous activity to quantify the intensity of 99mTc-pyrophosphate accumulation. The correlation of measured infarct volume with peak serum creatine kinase activity was significant (r = 0.60, p less than 0.01). There was also a significant linear correlation between the corrected infarct volume and peak serum creatine kinase activity (r = 0.71, p less than 0.01). Subgroup analysis showed a high correlation between corrected volume and peak creatine kinase activity in patients with anterior infarctions (r = 0.75, p less than 0.01) but a poor correlation in patients with inferior or posterior infarctions (r = 0.50, p less than 0.01). In both the early reperfusion and the no reperfusion groups, a good correlation was found between corrected infarct volume and peak serum creatine kinase activity (r = 0.76 and r = 0.76, respectively; p less than 0.01)

Ion-plasma gun for ion-milling machine

Science.gov (United States)

Kaminsky, Manfred S.; Campana, Jr., Thomas J.

1976-01-01

An ion gun includes an elongated electrode with a hollow end portion closed by a perforated end plate. The end plate is positioned parallel to a perforated flat electrode of opposite electrical polarity. An insulated sleeve encompasses the elongated electrode and extends outwardly from the perforated end towards the flat electrode. The sleeve length is separated into two portions of different materials. The first is formed of a high-temperature material that extends over the hollow portion of the elongated electrode where the arc is initiated by a point source electrode. The second sleeve portion extending over the remainder of the elongated electrode is of a resilient material for enhanced seal-forming ability and retention of plasma gas. Perforations are arranged in the flat electrode in a mutually opposing triangular pattern to project a plasma beam having a generally flat current profile towards a target requiring precision milling.

Mice lacking the UbCKmit isoform of creatine kinase reveal slower spatial learning acquisition, diminished exploration and habituation, and reduced acoustic startle reflex responses.

NARCIS (Netherlands)

Streijger, F.; Jost, C.R.; Oerlemans, F.T.J.J.; Ellenbroek, B.A.; Cools, A.R.; Wieringa, B.; Zee, C.E.E.M. van der

2004-01-01

Brain-type creatine kinases B-CK (cytosolic) and UbCKmit (mitochondrial) are considered important for the maintenance and distribution of cellular energy in the central nervous system. Previously, we have demonstrated an abnormal behavioral phenotype in mice lacking the B-CK creatine kinase isoform,

Stability of plasmas obtained in E.P.P.E; Stabilite des plasmas obtenus dans E. P. P. E

Energy Technology Data Exchange (ETDEWEB)

Adam, J; Rebut, P H; Torossian, A [Commissariat a l' Energie Atomique, Fontenay-aux-Roses (France). Centre d' Etudes Nucleaires

1964-07-01

The stability results obtained on Mest have been extended on a machine ten times more powerful: EppE. A plasma stable during its whole confinement time has been observed. This confinement time seems to be limited by the resistive diffusion of the magnetic fields through the plasma. The main characteristics of this plasma are: Time of confinement: 200 {mu}s; T{sub e} {approx} T{sub i}: 40 eV; {beta} = 8*{pi}*k*T*n{sub e}/B{sup 2}: 8%; n{sub e}: 2.5*10{sup 15}/cm{sup 3}. (authors) [French] Les resultats sur la stabilite obtenus dans Mest ont ete developpes dans une machine dix fois plus puissante: EppE. Un plasma stable pendant toute la duree de son confinement a ete observe et la limitation de ce temps est bien expliquee par la diffusion resistive des champs magnetiques a travers le plasma. Les principales caracteristiques du plasma d'EppE sont: Temps de confinement: 200 {mu}s; T{sub e} {approx} T{sub i}: 40 eV; {beta} 8*{pi}*k*T*n{sub e}/B{sup 2}: 8%; n{sub e}: 2.5*10{sup 15}/cm{sup 3}.

A creatina como suplemento ergogênico para atletas Creatine as an ergogenic supplement for athletes

Directory of Open Access Journals (Sweden)

José PERALTA

2002-01-01

Full Text Available A creatina vem sendo muito pesquisada devido ao seu potencial efeito no rendimento físico de atletas envolvidos em exercícios de alta intensidade e curta duração, intermitentes e com curtos períodos de recuperação. A creatina fosforilada é uma reserva de energia nas células musculares. Durante um exercício intenso, a sua quebra libera energia é usada para regenerar o trifosfato de adenosina. Aproximadamente 95% do pool de creatina encontra-se na musculatura esquelética e sua regeneração após o exercício é um processo dependente de oxigênio. Estudos mostram que a suplementação com este composto pode aumentar o pool orgânico em 10 a 20%, e este percentual é maior em atletas vegetarianos (até 60%. Ainda existe controvérsia com relação aos benefícios e riscos da suplementação com esta substância. Este estudo revisa alguns dos aspectos relacionados com o metabolismo da creatina e seu uso como substância ergogênica na prática desportiva.Several researches on creatine have been done due to its potential effects on the physical performance of athletes involved in high intensity, short duration and intermittent exercises with short periods of recovery. Phosphorylated creatine is an energy reserve in the muscle cells. During an intense exercise, its breakdown liberates energy used to regenerate adenosine triphosphate. Approximately 95% of the creatine pool is found in the skeletal muscle, and the regenerating process after exercise is oxygen dependent. Studies show that supplementation with this compound may procedure an increase of 10% to 20% in the organic pool, and this percentage is higher in vegetarian athletes (up to 60%. There is still controversy regarding the benefits and risks of supplementation with this substance. This paper reviews some aspects related to the creatine metabolism and its use as an ergogenic substance in sports practice.

Variations in creatine kinase activity and reactive oxygen species levels are involved in capacitation of bovine spermatozoa.

Science.gov (United States)

Córdoba, M; Pintos, L; Beconi, M T

2008-12-01

The generation of reactive oxygen species (ROS) is associated with some factors such as oxidative substrate sources, mitochondrial function and NAD(P)H oxidase activity. In bovine spermatozoa, heparin capacitation produces a respiratory burst sensitive to diphenyleneiodonium (DPI). Creatine kinase (CK) is related to extramitochondrial ATP disponibility. Our purpose was to determine the variation in ROS level and its relation with NAD(P)H oxidase sensitive to DPI and CK participation, as factors involved in redox state and energy generation in capacitation. The chlortetracycline technique was used to evaluate capacitation. CK activity and ROS level were measured by spectrophotometry and spectrofluorometry respectively. The capacitation percentage was increased by heparin or quercetin treatment (P level as control (238.62 +/- 23.47 arbitrary units per 10(8) spermatozoa) (P > 0.05). CK activity decreased by 50% with heparin or quercetin (P level variations were observed in heparin- or quercetin-treated samples (P bovine spermatozoa, capacitation requires equilibrium between oxidative damage susceptibility and ROS levels. CK activity is associated with redox state variation and energy sources. In conclusion, capacitation induction depends on NADPH oxidase and the shuttle creatine-creatine phosphate, both sensitive to DPI.

Metabolomic study of plasma from female mink (Neovison vison) with low and high residual feed intake during restrictive and ad libitum feeding

DEFF Research Database (Denmark)

Hedemann, Mette Skou; Damgaard, Birthe Marie

2012-01-01

was high during restrictive feeding, e.g. betaine, carnitine, and creatine. During ad libitum feeding the plasma level of metabolites that can be characterized as biomarkers of meat intake (creatinine, carnosine, 1- and 3 methylhistidine) was high. The plasma level of lysophosphatidylcholine species......Metabolite profiling may elucidate changes in metabolic pathways under various physiological or nutritional conditions. In the present study two groups of female mink characterized as having a high (16 mink) or low (14 mink) residual feed intake were investigated during restrictive and ad libitum...

The influence of high fat diets with different ketogenic ratios on the hippocampal accumulation of creatine - FTIR microspectroscopy study

Science.gov (United States)

Skoczen, A.; Setkowicz, Z.; Janeczko, K.; Sandt, Ch.; Borondics, F.; Chwiej, J.

2017-09-01

The main purpose of this study was the determination and comparison of anomalies in creatine (Cr) accumulation occurring within CA3 and DG areas of hippocampal formation as a result of two high-fat, carbohydrate-restricted ketogenic diets (KD) with different ketogenic ratio (KR). To reach this goal, Fourier transformed infrared microspectroscopy with synchrotron radiation source (SRFTIR microspectroscopy) was applied for chemical mapping of creatine absorption bands, occurring around 1304, 1398 and 2800 cm- 1. The samples were taken from three groups of experimental animals: control group (N) fed with standard laboratory diet, KD1 and KD2 groups fed with high-fat diets with KR 5:1 and 9:1 respectively. Additionally, the possible influence on the phosphocreatine (PhCr, the high energetic form of creatine) content was evaluated by comparative analysis of chemical maps obtained for creatine and for compounds containing phosphate groups which manifest in the spectra at the wavenumbers of around 1240 and 1080 cm- 1. Our results showed that KD2 strongly modifies the frequency of Cr inclusions in both analyzed hippocampal areas. Statistical analysis, performed with Mann-Whitney U test revealed increased accumulation of Cr within CA3 and DG areas of KD2 fed rats compared to both normal rats and KD1 experimental group. Moreover, KD2 diet may modify the frequency of PhCr deposits as well as the PhCr to Cr ratio.

Contribution to explanation of the effect of supplemented creatine in human metabolism

Czech Academy of Sciences Publication Activity Database

Navrátil, Tomáš; Kohlíková, E.; Petr, M.; Heyrovský, Michael; Pelclová, D.; Přistoupilová, K.; Přistoupil, T. I.; Šenholdová, Z.

2009-01-01

Roč. 112, č. 2 (2009), s. 500-506 ISSN 0308-8146 R&D Projects: GA ČR GA203/07/1195; GA AV ČR IAA400400806 Grant - others:Ga MZd(CZ) 8107-3/2004 Institutional research plan: CEZ:AV0Z40400503 Keywords : voltammetry * creatine * creatinine * folates Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 3.146, year: 2009

Ribose Supplementation Alone or with Elevated Creatine Does Not Preserve High Energy Nucleotides or Cardiac Function in the Failing Mouse Heart.

Directory of Open Access Journals (Sweden)

Kiterie M E Faller

Full Text Available Reduced levels of creatine and total adenine nucleotides (sum of ATP, ADP and AMP are hallmarks of chronic heart failure and restoring these pools is predicted to be beneficial by maintaining the diseased heart in a more favourable energy state. Ribose supplementation is thought to support both salvage and re-synthesis of adenine nucleotides by bypassing the rate-limiting step. We therefore tested whether ribose would be beneficial in chronic heart failure in control mice and in mice with elevated myocardial creatine due to overexpression of the creatine transporter (CrT-OE.FOUR GROUPS WERE STUDIED: sham; myocardial infarction (MI; MI+ribose; MI+CrT-OE+ribose. In a pilot study, ribose given in drinking water was bioavailable, resulting in a two-fold increase in myocardial ribose-5-phosphate levels. However, 8 weeks post-surgery, total adenine nucleotide (TAN pool was decreased to a similar amount (8-14% in all infarcted groups irrespective of the treatment received. All infarcted groups also presented with a similar and substantial degree of left ventricular (LV dysfunction (3-fold reduction in ejection fraction and LV hypertrophy (32-47% increased mass. Ejection fraction closely correlated with infarct size independently of treatment (r(2 = 0.63, p<0.0001, but did not correlate with myocardial creatine or TAN levels.Elevating myocardial ribose and creatine levels failed to maintain TAN pool or improve post-infarction LV remodeling and function. This suggests that ribose is not rate-limiting for purine nucleotide biosynthesis in the chronically failing mouse heart and that alternative strategies to preserve TAN pool should be investigated.

Possible limits of plasma linear colliders

Science.gov (United States)

Zimmermann, F.

2017-07-01

Plasma linear colliders have been proposed as next or next-next generation energy-frontier machines for high-energy physics. I investigate possible fundamental limits on energy and luminosity of such type of colliders, considering acceleration, multiple scattering off plasma ions, intrabeam scattering, bremsstrahlung, and betatron radiation. The question of energy efficiency is also addressed.

Creatine supplementation augments the increase in satellite cell and myonuclei number in human skeletal muscle induced by strength training

DEFF Research Database (Denmark)

Olsen, Steen; Aagaard, Per; Kadi, Fawzi

2006-01-01

The present study investigated the influence of creatine and protein supplementation on satellite cell frequency and number of myonuclei in human skeletal muscle during 16 weeks of heavy-resistance training. In a double-blinded design 32 healthy, male subjects (19-26 years) were assigned to stren......The present study investigated the influence of creatine and protein supplementation on satellite cell frequency and number of myonuclei in human skeletal muscle during 16 weeks of heavy-resistance training. In a double-blinded design 32 healthy, male subjects (19-26 years) were assigned...

The tyrosyl residues in creatine kinase. Modification by iodine.

Science.gov (United States)

Fattoum, A; Kassab, R; Pradel, L A

1975-10-20

The effect of the iodination of tyrosyl residues in creatine kinase from rabbit muscle has been investigated at alkaline pH after reversible masking of the reactive thiol groups. The conversion of 4-5 tyrosyl residues to monoiodotyrosines as measured by spectrotitration and by radioactive iodine labelling resulted in almost total loss of enzymic activity. The modified enzyme was unable to bind its nucleotide substrates but no significant conformational change was revealed by optical rotatory dispersion or Stokes radius measurements. However, change in the reactivity of some non-essential thiol groups, presumably those located near the active thiol groups, was observed.

Plasma cleaning for waste minimization

Energy Technology Data Exchange (ETDEWEB)

Ward, P.P.

1993-07-01

Although plasma cleaning is a recognized substitute for solvent cleaning in removing organic contaminants, some universal problems in plasma cleaning processes prevent wider use of plasma techniques. Lack of understanding of the fundamental mechanisms of the process, unreliable endpoint detection techniques, and slow process times make plasma cleaning processes less than desirable. Our approach to address these plasma cleaning problems is described. A comparison of plasma cleaning rates of oxygen and oxygen/sulfur hexafluoride gases shows that fluorine-containing plasmas can enhance etch rates by 400% over oxygen alone. A discussion of various endpoint indication techniques is discussed and compared for application suitability. Work toward a plasma cleaning database is discussed. In addition to the global problems of plasma cleaning, an experiment where the specific mixed-waste problem of removal of machine oils from radioactive scrap metal is discussed.

Estimated carrier frequency of creatine transporter deficiency in females in the general population using functional characterization of novel missense variants in the SLC6A8 gene.

Science.gov (United States)

DesRoches, Caro-Lyne; Patel, Jaina; Wang, Peixiang; Minassian, Berge; Salomons, Gajja S; Marshall, Christian R; Mercimek-Mahmutoglu, Saadet

2015-07-10

Creatine transporter deficiency (CRTR-D) is an X-linked inherited disorder of creatine transport. All males and about 50% of females have intellectual disability or cognitive dysfunction. Creatine deficiency on brain proton magnetic resonance spectroscopy and elevated urinary creatine to creatinine ratio are important biomarkers. Mutations in the SLC6A8 gene occur de novo in 30% of males. Despite reports of high prevalence of CRTR-D in males with intellectual disability, there are no true prevalence studies in the general population. To determine carrier frequency of CRTR-D in the general population we studied the variants in the SLC6A8 gene reported in the Exome Variant Server database and performed functional characterization of missense variants. We also analyzed synonymous and intronic variants for their predicted pathogenicity using in silico analysis tools. Nine missense variants were functionally analyzed using transient transfection by site-directed mutagenesis with In-Fusion HD Cloning in HeLa cells. Creatine uptake was measured by liquid chromatography tandem mass spectrometry for creatine measurement. The c.1654G>T (p.Val552Leu) variant showed low residual creatine uptake activity of 35% of wild type transfected HeLa cells and was classified as pathogenic. Three variants (c.808G>A; p.Val270Met, c.942C>G; p.Phe314Leu and c.952G>A; p.Ala318Thr) were predicted to be pathogenic based on in silico analysis, but proved to be non-pathogenic by our functional analysis. The estimated carrier frequency of CRTR-D was 0.024% in females in the general population. We recommend functional studies for all novel missense variants by transient transfection followed by creatine uptake measurement by liquid chromatography tandem mass spectrometry as fast and cost effective method for the functional analysis of missense variants in the SLC6A8 gene. Crown Copyright © 2015. Published by Elsevier B.V. All rights reserved.

Engineering of the 'PCAST machine'

International Nuclear Information System (INIS)

Sinnis, J.; Brooks, A.; Brown, T.

1996-01-01

The President's Committee of Advisors on Science and Technology (PCAST) has suggested that a device with a mission of ignition and moderate burn time could address the physics of burning plasmas at a lesser cost than ITER with its more comprehensive physics and technology mission. The Department of Energy commissioned a study to explore this PCAST suggestion. This paper describes the results of the engineering portion of the study of this 'PCAST Machine;' physics is covered in a companion paper authored by G.H. Neilson, et al; and the costs are covered in a companion paper by R.T. Simmons, et al. Both are published in the proceedings of this conference. The study was undertaken by a team under the direction of Bruce Montgomery that included representatives from MIT, PPPL, ORNL, LLNL, GA, Northrup-Grumman, and Stone and Webster. The performance requirements for the PCAST machine are to form and sustain a burning plasma for three helium accumulation times. The philosophy adopted for this design was to achieve the required performance at lower cost by decreasing the major radius to five meters, increasing the toroidal field to 7 tesla, and using stronger shaping. The major device parameters are given. 4 refs., 4 figs., 1 tab

The Current-Driven, Ion-Acoustic Instability in a Collisionless Plasma

DEFF Research Database (Denmark)

Michelsen, Poul; Pécseli, Hans; Juul Rasmussen, Jens

1979-01-01

The current-driven, ion-acoustic instability was investigated by means of an experiment performed in a collisionless plasma produced in a single-ended Q-machine. Reflections at the ends of the plasma column gave rise to a standing wave. Parameters of the instability were investigated, and it was ......, and it was demonstrated that the fluctuations in the plasma column behave as a classical Van der Pol oscillator. Accurate measurements of the growth rate of the instability can be performed by making explicit use of the particular properties of such a system.......The current-driven, ion-acoustic instability was investigated by means of an experiment performed in a collisionless plasma produced in a single-ended Q-machine. Reflections at the ends of the plasma column gave rise to a standing wave. Parameters of the instability were investigated...

Creatine Transporter Deficiency: Screening of Males with Neurodevelopmental Disorders and Neurocognitive Characterization of a Case.

Science.gov (United States)

Thurm, Audrey; Himelstein, Daniel; DʼSouza, Precilla; Rennert, Owen; Jiang, Susanqi; Olatunji, Damilola; Longo, Nicola; Pasquali, Marzia; Swedo, Susan; Salomons, Gajja S; Carrillo, Nuria

2016-05-01

Creatine transporter deficiency (CTD) is an X-linked, neurometabolic disorder associated with intellectual disability that is characterized by brain creatine (Cr) deficiency and caused by mutations in SLC6A8, the Cr transporter 1 protein gene. CTD is identified by elevated urine creatine/creatinine (Cr/Crn) ratio or reduced Cr peak on brain magnetic resonance spectroscopy; the diagnosis is confirmed by decreased Cr uptake in cultured fibroblasts, and/or identification of a mutation in the SLC6A8 gene. Prevalence studies suggest this disorder may be underdiagnosed. We sought to identify cases from a well-characterized cohort of children diagnosed with neurodevelopmental disorders. Urine screening for CTD was performed on a cohort of 46 males with autism spectrum disorder (ASD) and 9 males with a history of non-ASD developmental delay (DD) classified with intellectual disability. We identified 1 patient with CTD in the cohort based on abnormal urine Cr/Crn, and confirmed the diagnosis by the identification of a novel frameshift mutation in the SLC6A8 gene. This patient presented without ASD but with intellectual disability, and was characterized by a nonspecific phenotype of early language delay and DD that persisted into moderate-to-severe intellectual disability, consistent with previous descriptions of CTD. Identification of patients with CTD is possible by measuring urine Cr and Crn levels and the current case adds to the growing literature of neurocognitive deficits associated with the disorder that affect cognition, language and behavior in childhood.

Experimental setup for producing tungsten coated graphite tiles using plasma enhanced chemical vapor deposition technique for fusion plasma applications

International Nuclear Information System (INIS)

Chauhan, Sachin Singh; Sharma, Uttam; Choudhary, K.K.; Sanyasi, A.K.; Ghosh, J.; Sharma, Jayshree

2013-01-01

Plasma wall interaction (PWI) in fusion grade machines puts stringent demands on the choice of materials in terms of high heat load handling capabilities and low sputtering yields. Choice of suitable material still remains a challenge and open topic of research for the PWI community. Carbon fibre composites (CFC), Beryllium (Be), and Tungsten (W) are now being considered as first runners for the first wall components of future fusion machines. Tungsten is considered to be one of the suitable materials for the job because of its superior properties than carbon like low physical sputtering yield and high sputter energy threshold, high melting point, fairly high re-crystallization temperature, low fuel retention capabilities, low chemical sputtering with hydrogen and its isotopes and most importantly the reparability with various plasma techniques both ex-situ and in-situ. Plasma assisted chemical vapour deposition is considered among various techniques as the most preferable technique for fabricating tungsten coated graphite tiles to be used as tokamak first wall and target components. These coated tiles are more favourable compared to pure tungsten due to their light weight and easier machining. A system has been designed, fabricated and installed at SVITS, Indore for producing tungsten coated graphite tiles using Plasma Enhanced Chemical Vapor Deposition (PE-CVD) technique for Fusion plasma applications. The system contains a vacuum chamber, a turbo-molecular pump, two electrodes, vacuum gauges, mass analyzer, mass flow controllers and a RF power supply for producing the plasma using hydrogen gas. The graphite tiles will be put on one of the electrodes and WF6 gas will be inserted in a controlled manner in the hydrogen plasma to achieve the tungsten-coating with WF6 dissociation. The system is integrated at SVITS, Indore and a vacuum of the order of 3*10 -6 is achieved and glow discharge plasma has been created to test all the sub-systems. The system design with

The Relationship Between Creatine and Whey Protein Supplements Consumption and Anesthesia in Rats.

Science.gov (United States)

Saberi, Kianoush; Gorji Mahlabani, Mohammad Amin; Tashayoie, Mohammad; Nasiri Nejad, Farinaz

2016-02-01

Because the trend of pharmacotherapy is toward controlling diet rather than administration of drugs, in our study we examined the probable relationship between Creatine (Cr) or Whey (Wh) consumption and anesthesia (analgesia effect of ketamine). Creatine and Wh are among the most favorable supplements in the market. Whey is a protein, which is extracted from milk and is a rich source of amino acids. Creatine is an amino acid derivative that can change to ATP in the body. Both of these supplements result in Nitric Oxide (NO) retention, which is believed to be effective in N-Methyl-D-aspartate (NMDA) receptor analgesia. The main question of this study was whether Wh and Cr are effective on analgesic and anesthetic characteristics of ketamine and whether this is related to NO retention or amino acids' features. We divided 30 male Wistar rats to three (n = 10) groups; including Cr, Wh and sham (water only) groups. Each group was administered (by gavage) the supplements for an intermediate dosage during 25 days. After this period, they became anesthetized using a Ketamine-Xylazine (KX) and their time to anesthesia and analgesia, and total sleep time were recorded. Data were analyzed twice using the SPSS 18 software with Analysis of Variance (ANOVA) and post hoc test; first time we expunged the rats that didn't become anesthetized and the second time we included all of the samples. There was a significant P-value (P < 0.05) for total anesthesia time in the second analysis. Bonferroni multiple comparison indicated that the difference was between Cr and Sham groups (P < 0.021). The data only indicated that there might be a significant relationship between Cr consumption and total sleep time. Further studies, with rats of different gender and different dosage of supplement and anesthetics are suggested.

Creatine Kinase Activity Weakly Correlates to Volume Completed Following Upper Body Resistance Exercise

Science.gov (United States)

Machado, Marco; Willardson, Jeffrey M.; Silva, Dailson P.; Frigulha, Italo C.; Koch, Alexander J.; Souza, Sergio C.

2012-01-01

In the current study, we examined the relationship between serum creatine kinase (CK) activity following upper body resistance exercise with a 1- or 3-min rest between sets. Twenty men performed two sessions, each consisting of four sets with a 10-repetition maximum load. The results demonstrated significantly greater volume for the 3-min…

31P NMR measurements of the ADP concentration in yeast cells genetically modified to express creatine kinase

International Nuclear Information System (INIS)

Brindle, K.; Braddock, P.; Fulton, S.

1990-01-01

Rabbit muscle creatine kinase has been introduced into the yeast Saccharomyces cerevisiae by transforming cells with a multicopy plasmid containing the coding sequence for the enzyme under the control of the yeast phosphoglycerate kinase promoter. The transformed cells showed creating kinase activities similar to those found in mammalian heart muscle. 31 P NMR measurements of the near-equilibrium concentrations of phosphocreatine and cellular pH together with measurements of the total extractable concentrations of phosphocreatine and creatine allowed calculation of the free ADP/ATP ratio in the cell. The calculated ratio of approximately 2 was considerably higher than the ratio of between 0.06 and 0.1 measured directly in cell extracts

How the use of creatine supplements can elevate serum creatinine in the absence of underlying kidney pathology

Science.gov (United States)

Williamson, Lydia; New, David

2014-01-01

Serum creatinine is a widely used marker in the assessment of renal function. Elevated creatinine levels suggest kidney dysfunction, prompting the need for further investigation. This report describes a case in which the consumption of the bodybuilding supplement creatine ethyl ester resulted in raised serum creatinine in the absence of true underlying kidney pathology. The abnormalities reversed after discontinuation of the supplement. A case of pseudo renal failure was recognised and kidney function was concluded to be normal. This report aims to address the mechanisms by which the ingestion of creatine ethyl ester can mimic the blood results expected in advanced renal failure, and confronts the problems faced when relying on serum creatinine as a diagnostic tool. PMID:25239988

Simultaneous determination of creatinine and creatine in human serum by double-spike isotope dilution liquid chromatography-tandem mass spectrometry (LC-MS/MS) and gas chromatography-mass spectrometry (GC-MS).

Science.gov (United States)

Fernández-Fernández, Mario; Rodríguez-González, Pablo; Añón Álvarez, M Elena; Rodríguez, Felix; Menéndez, Francisco V Álvarez; García Alonso, J Ignacio

2015-04-07

This work describes the first multiple spiking isotope dilution procedure for organic compounds using (13)C labeling. A double-spiking isotope dilution method capable of correcting and quantifying the creatine-creatinine interconversion occurring during the analytical determination of both compounds in human serum is presented. The determination of serum creatinine may be affected by the interconversion between creatine and creatinine during sample preparation or by inefficient chemical separation of those compounds by solid phase extraction (SPE). The methodology is based on the use differently labeled (13)C analogues ((13)C1-creatinine and (13)C2-creatine), the measurement of the isotopic distribution of creatine and creatinine by liquid chromatography-tandem mass spectrometry (LC-MS/MS) and the application of multiple linear regression. Five different lyophilized serum-based controls and two certified human serum reference materials (ERM-DA252a and ERM-DA253a) were analyzed to evaluate the accuracy and precision of the proposed double-spike LC-MS/MS method. The methodology was applied to study the creatine-creatinine interconversion during LC-MS/MS and gas chromatography-mass spectrometry (GC-MS) analyses and the separation efficiency of the SPE step required in the traditional gas chromatography-isotope dilution mass spectrometry (GC-IDMS) reference methods employed for the determination of serum creatinine. The analysis of real serum samples by GC-MS showed that creatine-creatinine separation by SPE can be a nonquantitative step that may induce creatinine overestimations up to 28% in samples containing high amounts of creatine. Also, a detectable conversion of creatine into creatinine was observed during sample preparation for LC-MS/MS. The developed double-spike LC-MS/MS improves the current state of the art for the determination of creatinine in human serum by isotope dilution mass spectrometry (IDMS), because corrections are made for all the possible errors

Mitochondrial DNA depletion by ethidium bromide decreases neuronal mitochondrial creatine kinase: Implications for striatal energy metabolism.

Science.gov (United States)

Warren, Emily Booth; Aicher, Aidan Edward; Fessel, Joshua Patrick; Konradi, Christine

2017-01-01

Mitochondrial DNA (mtDNA), the discrete genome which encodes subunits of the mitochondrial respiratory chain, is present at highly variable copy numbers across cell types. Though severe mtDNA depletion dramatically reduces mitochondrial function, the impact of tissue-specific mtDNA reduction remains debated. Previously, our lab identified reduced mtDNA quantity in the putamen of Parkinson's Disease (PD) patients who had developed L-DOPA Induced Dyskinesia (LID), compared to PD patients who had not developed LID and healthy subjects. Here, we present the consequences of mtDNA depletion by ethidium bromide (EtBr) treatment on the bioenergetic function of primary cultured neurons, astrocytes and neuron-enriched cocultures from rat striatum. We report that EtBr inhibition of mtDNA replication and transcription consistently reduces mitochondrial oxygen consumption, and that neurons are significantly more sensitive to EtBr than astrocytes. EtBr also increases glycolytic activity in astrocytes, whereas in neurons it reduces the expression of mitochondrial creatine kinase mRNA and levels of phosphocreatine. Further, we show that mitochondrial creatine kinase mRNA is similarly downregulated in dyskinetic PD patients, compared to both non-dyskinetic PD patients and healthy subjects. Our data support a hypothesis that reduced striatal mtDNA contributes to energetic dysregulation in the dyskinetic striatum by destabilizing the energy buffering system of the phosphocreatine/creatine shuttle.

Mitochondrial DNA depletion by ethidium bromide decreases neuronal mitochondrial creatine kinase: Implications for striatal energy metabolism.

Directory of Open Access Journals (Sweden)

Emily Booth Warren

Full Text Available Mitochondrial DNA (mtDNA, the discrete genome which encodes subunits of the mitochondrial respiratory chain, is present at highly variable copy numbers across cell types. Though severe mtDNA depletion dramatically reduces mitochondrial function, the impact of tissue-specific mtDNA reduction remains debated. Previously, our lab identified reduced mtDNA quantity in the putamen of Parkinson's Disease (PD patients who had developed L-DOPA Induced Dyskinesia (LID, compared to PD patients who had not developed LID and healthy subjects. Here, we present the consequences of mtDNA depletion by ethidium bromide (EtBr treatment on the bioenergetic function of primary cultured neurons, astrocytes and neuron-enriched cocultures from rat striatum. We report that EtBr inhibition of mtDNA replication and transcription consistently reduces mitochondrial oxygen consumption, and that neurons are significantly more sensitive to EtBr than astrocytes. EtBr also increases glycolytic activity in astrocytes, whereas in neurons it reduces the expression of mitochondrial creatine kinase mRNA and levels of phosphocreatine. Further, we show that mitochondrial creatine kinase mRNA is similarly downregulated in dyskinetic PD patients, compared to both non-dyskinetic PD patients and healthy subjects. Our data support a hypothesis that reduced striatal mtDNA contributes to energetic dysregulation in the dyskinetic striatum by destabilizing the energy buffering system of the phosphocreatine/creatine shuttle.

Creatin-kinase elevation after accidental ingestion of almotriptan in an 18-month-old girl.

Science.gov (United States)

Castagno, E; Lupica, M; Viola, S; Savino, F; Miniero, R

2014-02-01

Few studies have been published to demonstrate tolerability and efficacy of almotriptan in adolescents and children with migraine, particularly in the first years of life, though preliminary results are favorable. We report the case of an 18-month-old infant with elevation of serum levels of creatin-kinase after the accidental ingestion of almotriptan. A previously healthy 18-month-old girl (weight: 13 kg) was admitted to our Department four hours after the accidental ingestion of 6.25 mg of almotriptan (0.48 mg/kg), without any specific symptom. The performed investigations showed high serum levels of creatin-kinase (CK) (527 IU/L; normal values: 24-170 IU/L). Transaminase, creatinine, aldolase, myoglobin and troponin T serum levels were normal. The electrocardiogram proved negative. Initial management consisted of parenteral rehydration with saline solution. CK levels lowered significantly at 12 hours (455 IU/L) and at 65 hours (188 IU/L) after the ingestion. No symptoms were observed before discharge and on follow-up.

NMR-based metabonomic studies reveal changes in the biochemical profile of plasma and urine from pigs fed high-fibre rye bread

DEFF Research Database (Denmark)

Bertram, Hanne C; Bach Knudsen, Knud E; Serena, Anja

2006-01-01

could be ascribed to differences in the content of betaine and creatine/creatinine between the two diets, and LC-MS analyses verified a significantly lower content of creatinine in WGD urine samples compared with NWD urine samples. In conclusion, using an explorative approach, the present studies...... disclosed biochemical effects of a wholegrain diet on plasma betaine content and excretion of betaine and creatinine....

NMR-based metabonomic studies reveal changes in the biochemical profile of plasma and urine from pigs fed high fibre rye bread

DEFF Research Database (Denmark)

Bertram, Hanne C.; Bach Knudsen, Knud E.; Serena, Anja

2006-01-01

could be ascribed to differences in the content of betaine and creatine/creatinine between the two diets, and LC-MS analyses verified a significantly lower content of creatinine in WGD urine samples compared with NWD urine samples. In conclusion, using an explorative approach, the present studies...... disclosed biochemical effects of a wholegrain diet on plasma betaine content and excretion of betaine and creatinine....

Charging of dust grains in a plasma with negative ions

International Nuclear Information System (INIS)

Kim, Su-Hyun; Merlino, Robert L.

2006-01-01

The effect of negative ions on the charging of dust particles in a plasma is investigated experimentally. A plasma containing a very low percentage of electrons is formed in a single-ended Q machine when SF 6 is admitted into the vacuum system. The relatively cold Q machine electrons (T e ≅0.2 eV) readily attach to SF 6 molecules to form SF 6 - negative ions. Calculations of the dust charge indicate that for electrons, negative ions, and positive ions of comparable temperatures, the charge (or surface potential) of the dust can be positive if the positive ion mass is smaller than the negative ion mass and if ε, the ratio of the electron to positive ion density, is sufficiently small. The Q machine plasma is operated with K + positive ions (mass 39 amu) and SF 6 - negative ions (mass 146 amu), and also utilizes a rotating cylinder to dispense dust into the plasma column. Analysis of the current-voltage characteristics of a Langmuir probe in the dusty plasma shows evidence for the reduction in the (magnitude) of the negative dust charge and the transition to positively charged dust as the relative concentration of the residual electrons is reduced. Some remarks are offered concerning experiments that could become possible in a dusty plasma with positive grains

Nuclear Overhauser effect studies on the conformation of magnesium adenosine 5'-triphosphate bound to rabbit muscle creatine kinase

International Nuclear Information System (INIS)

Rosevear, P.R.; Powers, V.M.; Dowhan, D.; Mildvan, A.S.; Kenyon, G.L.

1987-01-01

Nuclear Overhauser effects were used to determine interproton distances on MgATP bound to rabbit muscle creatine kinase. The internuclear distances were used in a distance geometry program that objectively determines both the conformation of the bound MgATP and its uniqueness. Two classes of structures were found that satisfied the measured interproton distances. Both classes had the same anti glycosidic torsional angle (X = 78 +/- 10 0 ) but differed in their ribose ring puckers (O1'-endo or C4'-exo). The uniqueness of the glycosidic torsional angle is consistent with the preference of creatine kinase for adenine nucleotides. One of these conformations of MgATP bound to creatine kinase is indistinguishable from the conformation found for Co(NH 3 ) 4 ATP bound to the catalytic subunit of protein kinase, which also has a high specificity for adenine nucleotides. Distance geometry calculations also suggest that upper limit distances, when low enough (≤ 3.4 A), can be used instead of measured distances to define, within experimental error, the glycosidic torsional angle of bound nucleotides. However, this approach does not permit an evaluation of the ribose ring pucker

ITER plasma safety interface models and assessments

International Nuclear Information System (INIS)

Uckan, N.A.; Bartels, H-W.; Honda, T.; Amano, T.; Boucher, D.; Post, D.; Wesley, J.

1996-01-01

Physics models and requirements to be used as a basis for safety analysis studies are developed and physics results motivated by safety considerations are presented for the ITER design. Physics specifications are provided for enveloping plasma dynamic events for Category I (operational event), Category II (likely event), and Category III (unlikely event). A safety analysis code SAFALY has been developed to investigate plasma anomaly events. The plasma response to ex-vessel component failure and machine response to plasma transients are considered

Screening for primary creatine deficiencies in French patients with unexplained neurological symptoms

Directory of Open Access Journals (Sweden)

Cheillan David

2012-12-01

Full Text Available Abstract A population of patients with unexplained neurological symptoms from six major French university hospitals was screened over a 28-month period for primary creatine disorder (PCD. Urine guanidinoacetate (GAA and creatine:creatinine ratios were measured in a cohort of 6,353 subjects to identify PCD patients and compile their clinical, 1H-MRS, biochemical and molecular data. Six GAMT [N-guanidinoacetatemethyltransferase (EC 2.1.1.2] and 10 X-linked creatine transporter (SLC6A8 but no AGAT (GATM [L-arginine/glycine amidinotransferase (EC 2.1.4.1] deficient patients were identified in this manner. Three additional affected sibs were further identified after familial inquiry (1 brother with GAMT deficiency and 2 brothers with SLC6A8 deficiency in two different families. The prevalence of PCD in this population was 0.25% (0.09% and 0.16% for GAMT and SLC6A8 deficiencies, respectively. Seven new PCD-causing mutations were discovered (2 nonsense [c.577C > T and c.289C > T] and 1 splicing [c.391 + 15G > T] mutations for the GAMT gene and, 2 missense [c.1208C > A and c.926C > A], 1 frameshift [c.930delG] and 1 splicing [c.1393-1G > A] mutations for the SLC6A8 gene. No hot spot mutations were observed in these genes, as all the mutations were distributed throughout the entire gene sequences and were essentially patient/family specific. Approximately one fifth of the mutations of SLC6A8, but not GAMT, were attributed to neo-mutation, germinal or somatic mosaicism events. The only SLC6A8-deficient female patient in our series presented with the severe phenotype usually characterizing affected male patients, an observation in agreement with recent evidence that is in support of the fact that this X-linked disorder might be more frequent than expected in the female population with intellectual disability.

Screening for primary creatine deficiencies in French patients with unexplained neurological symptoms

Science.gov (United States)

2012-01-01

A population of patients with unexplained neurological symptoms from six major French university hospitals was screened over a 28-month period for primary creatine disorder (PCD). Urine guanidinoacetate (GAA) and creatine:creatinine ratios were measured in a cohort of 6,353 subjects to identify PCD patients and compile their clinical, 1H-MRS, biochemical and molecular data. Six GAMT [N-guanidinoacetatemethyltransferase (EC 2.1.1.2)] and 10 X-linked creatine transporter (SLC6A8) but no AGAT (GATM) [L-arginine/glycine amidinotransferase (EC 2.1.4.1)] deficient patients were identified in this manner. Three additional affected sibs were further identified after familial inquiry (1 brother with GAMT deficiency and 2 brothers with SLC6A8 deficiency in two different families). The prevalence of PCD in this population was 0.25% (0.09% and 0.16% for GAMT and SLC6A8 deficiencies, respectively). Seven new PCD-causing mutations were discovered (2 nonsense [c.577C > T and c.289C > T] and 1 splicing [c.391 + 15G > T] mutations for the GAMT gene and, 2 missense [c.1208C > A and c.926C > A], 1 frameshift [c.930delG] and 1 splicing [c.1393-1G > A] mutations for the SLC6A8 gene). No hot spot mutations were observed in these genes, as all the mutations were distributed throughout the entire gene sequences and were essentially patient/family specific. Approximately one fifth of the mutations of SLC6A8, but not GAMT, were attributed to neo-mutation, germinal or somatic mosaicism events. The only SLC6A8-deficient female patient in our series presented with the severe phenotype usually characterizing affected male patients, an observation in agreement with recent evidence that is in support of the fact that this X-linked disorder might be more frequent than expected in the female population with intellectual disability. PMID:23234264

Overview of engineering design, manufacturing and assembly of JT-60SA machine

Energy Technology Data Exchange (ETDEWEB)

Di Pietro, Enrico, E-mail: enrico.dipietro@jt60sa.org [JT-60SA EU Home Team, Fusion for Energy, Boltzmannstrasse 2, Garching 85748 (Germany); Barabaschi, Pietro [JT-60SA EU Home Team, Fusion for Energy, Boltzmannstrasse 2, Garching 85748 (Germany); Kamada, Yutaka [JT-60SA JA Home Team, Japan Atomic Energy Agency, 801-1 Mukoyama, Naka, Ibaraki 311-0193 (Japan); Ishida, Shinichi [JT-60SA JA Project Team, Japan Atomic Energy Agency, 801-1 Mukoyama, Naka, Ibaraki 311-0193 (Japan)

2014-10-15

The JT-60SA experiment is one of the three projects to be undertaken in Japan as part of the Broader Approach Agreement, conducted jointly by Europe and Japan, and complementing the construction of ITER in Europe. The JT-60SA device is a fully superconducting tokamak capable of confining break-even equivalent deuterium plasmas with equilibria covering high plasma shaping with a low aspect ratio at a maximum plasma current of I{sub p} = 5.5 MA. This makes JT-60SA capable to support and complement ITER in all the major areas of fusion plasma development necessary to decide DEMO reactor construction. After a complex start-up phase due to the necessity to carry out a re-baselining effort with the purpose to fit in the original budget while aiming to retain the machine mission, performance, and experimental flexibility, in 2009 detailed design could start. With the majority of time-critical industrial contracts in place, in 2012, it was possible to establish a credible time plan, and now, the project is progressing on schedule towards the first plasma in March 2019. After careful and focused R and D and qualification tests, the procurement of the major components and plant is now well advanced in manufacturing design and/or fabrication. In the meantime the disassembly of the JT-60U machine has been completed and the engineering of the JT-60SA assembly process has been developed. The actual assembly of JT-60SA started in January 2013 with the installation of the cryostat base. The paper gives an overview of the present status of the engineering design, manufacturing and assembly of the JT-60SA machine.

Universal Instability in a Thermal Plasma Device (Q-Machine); Instabilite Universelle dans une Machine a Plasma Thermique (Machine-Q); Issledovaniya universal'noj neustojchivosti v ustrojstve dlya termicheski ionizovannoj plazmy; Inestabilidad Universal en un Dispositivo de Plasma Termico (Maquina Q)

Energy Technology Data Exchange (ETDEWEB)

Lashinsky, H. [University Of Maryland, College Park, MD (United States)

1966-04-15

The fully ionized column in, a thermal plasma device (Q-machine) provides a convenient medium for studying the universal (drift-wave) instability arising from the joint effect of the finite ion Larmor radius and the density gradient perpendicular to the magnetic confining field. The pertinent dimensionless parameters can be varied over a range such that the results can be scaled to make comparisons.with plasmas of thermonuclear interest, and the instability can be excited in controlled fashion by appropriate adjustment of the sheath conditions at the metal end plates by using sheath-control techniques that are discussed together with the underlying theory. By exploiting these techniques the oscillation amplitude can be held at arbitrarily low levels and the behaviour of the instability can be traced from the low-amplitude (e Empty-Set /kT {approx}10{sup -3}) ''quasilinear'' regime, characterized by a monochromatic ''locked-mode'' spectrum, into the non-linear regime; and then into a weakly turbulent state (e Empty-Set /kT Less-Than-Or-Equivalent-To 1) characterized by a noisy ''hash'' spectrum. A novel ''raster-display'' method provides a complete picture of the development of the instability and the transition to turbulence. The experimentally determined basic characteristics of the instability such as the mode frequencies, direction of azimuthal propagation, coherence properties, density independence, magnetic field dependence, and spatial dependence of mode amplitude, are in good qualitative agreement with the linear theory of the universal instability. Experiments have also been carried out on the effect of column length on the real part of the frequency (approximately a 10% correction) and on the imaginary part. The effect on the latter is due to ion Landau damping and the method provides an excellent means of studying the Landau damping mechanism itself. The results of these experiments are also in good agreement with the linear theory and have, in addition

EFFECTS OF CREATINE, GINSENG, AND ASTRAGALUS SUPPLEMENTATION ON STRENGTH, BODY COMPOSITION, MOOD, AND BLOOD LIPIDS DURING STRENGTH-TRAINING IN OLDER ADULTS

Directory of Open Access Journals (Sweden)

Michael E. Rogers

2006-03-01

Full Text Available The effects of supplemental dietary creatine and a botanical extract consisting of ginseng and astragalus were evaluated in 44 adults aged 55-84 years participating in a 12-week strength-training program. Participants consumed creatine only (Cr, creatine plus botanical extract (CrBE, or placebo (PL, and performed bench press, lat pull down, biceps curl, leg press, knee extension, and knee flexion for 3 sets of 8-12 reps on 3 days per week for 12 weeks. The 1-repetition maximum for each exercise, body composition (full-body DEXA, blood lipids, and mood states were evaluated before and after the intervention. Training improved (p < 0.05 strength and lean mass for all groups, however greater gains were observed with Cr and CrBE compared with placebo (but no difference was found between Cr and CrBE. Only CrBE improved blood lipids and self-reported vigor, and the CrBE group lost significantly more body fat and gained more bench press strength than Cr. These results indicate that strength and lean mass gains achieved by older adults participating in a strength training program can be enhanced with creatine supplementation, and that ginseng and astragalus may provide additional health and psychological benefits. However, these herbs do not appear to have an additive effect on strength and lean mass gains during training

Plasma Chamber Design and Fabrication Activities

Science.gov (United States)

Parodi, B.; Bianchi, A.; Cucchiaro, A.; Coletti, A.; Frosi, P.; Mazzone, G.; Pizzuto, A.; Ramogida, G.; Coppi, B.

2006-10-01

A fabrication procedure for a typical Plasma Chamber (PC) sector has been developed to cover all the manufacturing phases, from the raw materials specification (including metallurgical processes) to the machining operations, acceptance procedures and vacuum tests. Basically, the sector is made of shaped elements (forged or rolled) welded together using special fixtures and then machined to achieve the final dimensional accuracy. An upgraded design of the plasma chamber's vertical support that can withstand the estimated electromagnetic loads (Eddy and Halo current plus horizontal net force resulting from the worst plasma disruption scenario VDE, Vertical Displacement Event) has been completed. The maintenance of the radial support can take place hands-on with a direct access from outside the cryostat. With the present design, vacuum tightness is achieved by welding conducted with automatic welding heads. On the outer surface of the PC a dedicated duct system, filled by helium gas, is included to cool down the PC to room temperature when needed.

Contraction-mediated glycogenolysis in mouse skeletal muscle lacking creatine kinase: the role of phosphorylase b activation.

NARCIS (Netherlands)

Katz, A.; Andersson, D.C.; Yu, J.; Norman, B.; Sandstrom, M.E.; Wieringa, B.; Westerblad, H.

2003-01-01

Skeletal muscle that is deficient in creatine kinase (CK-/-) exhibits accelerated glycogenolysis during contraction. Understanding this phenomenon could provide insight into the control of glycogenolysis during contraction. Therefore, glycogen breakdown was investigated in isolated extensor

Leptin in milk and plasma of dairy asses

Directory of Open Access Journals (Sweden)

F. Fantuz

2010-04-01

Full Text Available Milk and plasma leptin levels have been studied in dairy asses machine milked according to two different routines: 20 pregnant, pluriparous asses, were divided into two groups subjected, every 28 d for 150 d, to two consecutive milkings carried out at different intervals, i.e. 20 vs. 4 hours interval, respectively for group A and group B. During the study, the declining total milk obtained by machine milking was unaffected by the different milking strategies; body condition score of asses as well did not vary between the groups. Different milking intervals did not significantly influence skimmed milk leptin content neither plasma leptin level. Moreover, we did not find significant variation in plasma leptin neither correlation with BCS, indicating that in donkey pregnancy inhibits the cross talk between hypothalamus and adipose tissue.

Fueling, heating, and leaking of plasma in mirror reactors

International Nuclear Information System (INIS)

Carlson, G.A.; Moir, R.W.

1976-01-01

The principles of mirror machine confinement are reviewed with emphasis on the physical process of neutral beam injection and plasma end leakage. The characteristics of efficient neutral beam injectors and direct energy convertors for the plasma and leakage are described

Cerebral proton magnetic resonance spectroscopy demonstrates reversibility of N-acetylaspartate/creatine in gray matter after delayed encephalopathy due to carbon monoxide intoxication

DEFF Research Database (Denmark)

Hansen, Marco Bo; Kondziella, Daniel; Danielsen, Else Rubæk

2014-01-01

with cerebral proton magnetic resonance spectroscopy showed a dramatically decrease in N-acetylaspartate to total creatine ratios and elevated lactate levels in the gray matter. Subsequently, our patient received six additional sessions of hyperbaric oxygen therapy with only minimal recovery. At six...... reversal of N-acetylaspartate to total creatine ratios in gray matter has, to our knowledge, never been described before and shows that severe, initial measurements may not predict poor long-term patient outcome....

Measurement of the electron attachment rates for SF6 and C7F14 at Te=0.2 eV in a magnetized Q machine plasma

International Nuclear Information System (INIS)

Merlino, Robert L.; Kim, Su-Hyun

2008-01-01

Electron attachment rates for SF 6 and C 7 F 14 were measured in a magnetized Q machine plasma at an electron temperature of 0.2±0.02 eV and with neutral gas pressures of P∼10 -4 Torr. The rate constants for attachment to SF 6 and C 7 F 14 were (7.6±2.0)x10 -8 and (2.2±0.9)x10 -7 cm 3 s -1 , respectively.

Multi-Pulse DARHT Machine-Plasma Plume Problem

International Nuclear Information System (INIS)

Lauer, E J

2004-01-01

The plasma current decay time constant is predicted to be short compared to the pulse length and so self-focusing is predicted for most of the beam pulse. Four- pulse beam envelopes for a high dose case require mitigation, those for a low dose case do not. Methods of mitigation are summarized. Hose instability growth in the plume length is predicted to be minimal

Plasma engineering: a perspective

International Nuclear Information System (INIS)

Gralnick, S.L.

1978-01-01

This review paper will present the authors perspective of the field of Plasma Engineering as it has evolved over the preceding five years. This embrionic discipline has grown in that period of time to the point where it is sufficiently mature to become part of the curriculum, and a speciality within, the discipline of Nuclear Engineering. Plasma Engineering can be distinguished from the underlying science of plasma physics in that in the pursuit of the latter, our goal is the understanding of the fundamental processes governing the behavior of plasmas while the former discipline seeks the embodiment of these concepts in useful devices. Consequent to this goal, the plasma engineer, of necessity, is concerned with the interfaces between a plasma configuration and the device by which it is produced and maintained. These interface problems, often referred to as kitchen physics are multidisciplinary in nature, and their solution requires careful attention to both plasma physics and machine engineering detail

Maternal creatine supplementation during pregnancy prevents acute and long-term deficits in skeletal muscle after birth asphyxia: a study of structure and function of hind limb muscle in the spiny mouse.

Science.gov (United States)

LaRosa, Domenic A; Ellery, Stacey J; Snow, Rod J; Walker, David W; Dickinson, Hayley

2016-12-01

Maternal antenatal creatine supplementation protects the brain, kidney, and diaphragm against the effects of birth asphyxia in the spiny mouse. In this study, we examined creatine's potential to prevent damage to axial skeletal muscles. Pregnant spiny mice were fed a control or creatine-supplemented diet from mid-pregnancy, and 1 d before term (39 d), fetuses were delivered by c-section with or without 7.5 min of birth asphyxia. At 24 h or 33 ± 2 d after birth, gastrocnemius muscles were obtained for ex-vivo study of twitch-tension, muscle fatigue, and structural and histochemical analysis. Birth asphyxia significantly reduced cross-sectional area of all muscle fiber types (P creatine treatment prevented all asphyxia-induced changes in the gastrocnemius, improved motor performance. This study demonstrates that creatine loading before birth protects the muscle from asphyxia-induced damage at birth.

The influence of plasma motion on disruption generated runaway electrons

International Nuclear Information System (INIS)

Russo, A.J.

1991-01-01

One of the possible consequences of disruptions is the generation of runaway electrons which can impact plasma facing components and cause damage due to high local energy deposition. This problem becomes more serious as the machine size and plasma current increases. Since large size and high currents are characteristics of proposed future machines, control of runaway generation is an important design consideration. A lumped circuit model for disruption runaway electron generation indicates that control circuitry on strongly influence runaway behavior. A comparison of disruption data from several shots on JET and D3-D with model results, demonstrate the effects of plasma motion on runaway number density and energy. 6 refs., 12 figs

Experimental and numerical investigations of plasma turbulence

International Nuclear Information System (INIS)

Huld, T.

1990-07-01

Turbulence in plasmas has been investigated experimentally and numerically. The work described here is divided into four parts: - experiments on edge turbulence in a single-ended Q-machine. Convective cells are investigated in detail together with the anomalous transport caused by them. - Numerical simulation of the edge turbulence in the Q-machine. This simulation uses spectral methods to solve Euler's equation in a cylindrical geometry. - Measurements on wave propagation and the ion beam instability in an unmagnetized plasma with an ion beam with a finite diameter. - Development of software for the automated acquisition of data. This program can control an experiment as well as make measurements. It also include a graphics part. (author) 66 ills., 47 refs

Creatine level and lipide analysis in radiosensitive organs of mice after total body irradiation - a contribution to further development of biologic radiodosimetry

Energy Technology Data Exchange (ETDEWEB)

Breiter, N; Ungemach, F R; Hegner, D; Beck, G; Mayr, A

1986-02-01

The authors intended to test the suitability of creatine level and/or certain criteria of lipide analysis in radiosensitive organs for an individual (i.e. considering biologic variations of radiosensitivity), qualitative and quantitative demonstration of an irradiation damage. It was found that creatine determination and several criteria of lipide peroxydation are not suitable for a biologic radiation dosimetry due to the absence of organ dependent, radiation dose dependent, and time dependent changes. The reasons are discussed.

Creatine level and lipide analysis in radiosensitive organs of mice after total body irradiation - a contribution to further development of biologic radiodosimetry

International Nuclear Information System (INIS)

Breiter, N.; Ungemach, F.R.; Hegner, D.; Beck, G.; Mayr, A.

1986-01-01

The authors intended to test the suitability of creatine level and/or certain criteria of lipide analysis in radiosensitive organs for an individual (i.e. considering biologic variations of radiosensitivity), qualitative and quantitative demonstration of an irradiation damage. It was found that creatine determination and several criteria of lipide peroxydation are not suitable for a biologic radiation dosimetry due to the absence of organ dependent, radiation dose dependent, and time dependent changes. The reasons are discussed. (orig.) [de

Hydrogen peroxide (H2O2) irreversibly inactivates creatine kinase from Pelodiscus sinensis by targeting the active site cysteine.

Science.gov (United States)

Wang, Wei; Lee, Jinhyuk; Hao, Hao; Park, Yong-Doo; Qian, Guo-Ying

2017-12-01

Creatine kinase (EC 2.7.3.2, CK) plays an important role in cellular energy metabolism and homeostasis by catalysing the transfer of phosphate between ATP and creatine phosphate. In this study, we investigated the effects of H 2 O 2 on PSCKM (muscle type creatine kinase from Pelodiscus sinensis) by the integrating method between enzyme kinetics and docking simulations. We found that H 2 O 2 strongly inactivated PSCKM (IC 50 =0.25mM) in a first-order kinetic process, and targeted the active site cysteine directly. A conformational study showed that H 2 O 2 did not induce the tertiary structural changes in PSCKM with no extensive exposure of hydrophobic surfaces. Sequential docking simulations between PSCKM and H 2 O 2 indicated that H 2 O 2 interacts with the ADP binding region of the active site, consistent with experimental results that demonstrated H 2 O 2 -induced inactivation. Our study demonstrates the effect of H 2 O 2 on PSCKM enzymatic function and unfolding, and provides important insight into the changes undergone by this central metabolic enzyme in ectothermic animals in response to the environment. Copyright © 2017 Elsevier B.V. All rights reserved.

International school of plasma physics course on instabilities and confinement in toroidal plasmas. Varenna (Italy), September 27-October 9, 1971

International Nuclear Information System (INIS)

1974-11-01

The lectures of a Varenna Summer School about the theme Instabilities and Confinement in toroidal Plasmas are given. The topics included are: high-beta toroidal pinches, non-MHD instabilities and anomalous transport, analogy between turbulent transfer in velocity space and plasma collisioned transport in real space, the magnetohydrodynamic approach of plasma confinement in closed magnetic configurations, properties of isodynamical equilibrium configurations and their generalization, transport theory for toroidal plasmas, plasma physics, low-β toroidal machines, the neoclassical theory of transit time magnetic pumping, radio frequency heating of toroidal plasmas, plasma heating at lower hybrid frequency, RF-plasma heating with L-structures, numerical simulation, dynamical stabilization of low frequency waves in inhomogeneous plasmas, dynamic and feedback stabilization of plasmas and problems with nuclear fusion reactors

Supplemented Creatine Induces Changes in Human Metabolism of Thiocompounds and One- and Two-Carbon Units

Czech Academy of Sciences Publication Activity Database

Navrátil, Tomáš; Kohlíková, E.; Petr, M.; Pelclová, D.; Heyrovský, Michael; Přistoupilová, K.

2010-01-01

Roč. 59, č. 3 (2010), s. 431-442 ISSN 0862-8408 R&D Projects: GA AV ČR IAA400400806 Institutional research plan: CEZ:AV0Z40400503 Keywords : creatine * creatinine * folates * homocysteine Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 1.646, year: 2010

Cognitive effects of creatine monohydrate adjunctive therapy in patients with bipolar depression: Results from a randomized, double-blind, placebo-controlled trial.

Science.gov (United States)

Toniolo, Ricardo Alexandre; Fernandes, Francy de Brito Ferreira; Silva, Michelle; Dias, Rodrigo da Silva; Lafer, Beny

2017-12-15

Depressive episodes and cognitive impairment are major causes of morbidity and dysfunction in individuals suffering from bipolar disorder (BD). Novel treatment approaches that target clinical and cognitive aspects of bipolar depression are needed, and research on pathophysiology suggests that mitochondrial modulators such as the nutraceutical creatine monohydrate might have a therapeutic role for this condition. Eighteen (N=18) patients with bipolar depression according to DSM-IV criteria who were enrollled in a 6-week, randomized, double-blind, placebo-controlled trial of creatine monohydrate 6g daily as adjunctive therapy were submitted to neuropsychological assessments (Wisconsin Card Sorting Test, Digit Span subtest of the Wechsler Adult Intelligence Scale-Third Edition, Stroop Color-Word Test, Rey-Osterrieth complex figure test, FAS Verbal Fluency Test) at baseline and week 6. There was a statistically significant difference between the treatment groups of the change on the total scores after 6 weeks in the verbal fluency test, with improvement in the group receiving adjunctive treatment with creatine. We did not find significant differences between the groups of the changes on other neuropsychological tests. Small sample and lack of a control group of healthy subjects. Our trial, which was the first to investigate the cognitive effects of creatine monohydrate on bipolar depression, indicates that supplementation with this nutraceutical for 6 weeks is associated with improvement in verbal fluency tests in patients with this condition. Copyright © 2016 Elsevier B.V. All rights reserved.

In silico investigation of molecular effects caused by missense mutations in creatine transporter protein

Science.gov (United States)

Zhang, Zhe; Schwatz, Charles; Alexov, Emil

2011-03-01

Creatine transporter (CT) protein, which is encoded by SLC6A8 gene, is essential for taking up the creatine in the cell, which in turn plays a key role in the spatial and temporal maintenance of energy in skeletal and cardiac muscle cells. It was shown that some missense mutations in CT cause mental retardation, while others are harmless non-synonymous single nucleoside polymorphism (nsSNP). Currently fifteen missense mutations in CT are known, among which twelve are disease-causing. Sequence analysis reveals that there is no clear trend distinguishing disease-causing from harmless missense mutations. Because of that, we built 3D model of the CT using highly homologous template and use the model to investigate the effects of mutations of CT stability and hydrogen bond network. It is demonstrated that disease-causing mutations affect the folding free energy and ionization states of titratable group in much greater extend as compared with harmless mutations. Supported by grants from NLM, NIH, grant numbers 1R03LM009748 and 1R03LM009748-S1.

The Effect of Creatin and Carnitine Supplementation on 5 kmClassic and 10 km Free Styles Race Performance of Cross Country Skiers

OpenAIRE

Ebru ÇETİN

2004-01-01

This İnvestigation examined the effect of creatin and carnitine supplementation on 5 km classic and 10 km free styles race performance of competitive cross country skiers.Eighteen highly trained (12 male and 6 female) cross country skiers aged 13-16 years seperated into 3 equal groups. All groups participated in the 5 km classic and 10 km free races styles in Erciyes at 2200m altitude ski center before the carnitine and creatine loading. After the race subjects were seperated into carnitine, ...

Sample preparation of metal alloys by electric discharge machining

Science.gov (United States)

Chapman, G. B., II; Gordon, W. A.

1976-01-01

Electric discharge machining was investigated as a noncontaminating method of comminuting alloys for subsequent chemical analysis. Particulate dispersions in water were produced from bulk alloys at a rate of about 5 mg/min by using a commercially available machining instrument. The utility of this approach was demonstrated by results obtained when acidified dispersions were substituted for true acid solutions in an established spectrochemical method. The analysis results were not significantly different for the two sample forms. Particle size measurements and preliminary results from other spectrochemical methods which require direct aspiration of liquid into flame or plasma sources are reported.

Preliminary conceptual engineering design considerations for the MX machine

International Nuclear Information System (INIS)

Bulmer, R.H.; Calderon, M.U.; Hibbs, S.M.; Kozman, T.A.

1975-01-01

The mirror experiment was designed to develop the technologies necessary to make the transition from the presently small-scale physics experiments (2XIIB and BBII) to large-scale steady-state DT burning systems, such as the Fusion Engineering Research Facility (FERF) and Controlled Thermonuclear Reactors (CTR) based on plasma confinement in open magnetic geometry. The confinement parameters in the design of the present machine include a 20-kG central field with a mirror ratio of 2 to 1 and an overall BL product approximately 5 times greater than that currently available with the 2XIIB compression coils (or a mirror-to-mirror length of 3.4 m). Several types of Yin-Yang minimum parallel B parallel geometries were studied, and a ''displaced'' Yin-Yang was chosen because the center of the machine is easily accessable between the coils and between the magnet lobes. Other important design considerations include the target plasma system, the vacuum system, and the injectors. The target plasma system includes a pellet generating system used to produce a 400-μm deuterium pellet and a two-arm laser system where the laser energy is produced from a 1-kJ, 10-GW CO 2 laser at 100 ns

Summary of UCRL pyrotron (mirror machine) program

Energy Technology Data Exchange (ETDEWEB)

Post, R F [Radiation Laboratory, University of California, Livermore, CA (United States)

1958-07-01

Under the sponsorship of the Atomic Energy Commission, work has been going forward at the University of California Radiation Laboratory since 1952 to investigate the application of the so-called 'magnetic mirror' effect to the creation and confinement of a high temperature plasma. This report presents some of the theory of operation of the Mirror Machine, and summarizes the experimental work which has been carried out.

Analysis of machining and machine tools

CERN Document Server

Liang, Steven Y

2016-01-01

This book delivers the fundamental science and mechanics of machining and machine tools by presenting systematic and quantitative knowledge in the form of process mechanics and physics. It gives readers a solid command of machining science and engineering, and familiarizes them with the geometry and functionality requirements of creating parts and components in today’s markets. The authors address traditional machining topics, such as: single and multiple point cutting processes grinding components accuracy and metrology shear stress in cutting cutting temperature and analysis chatter They also address non-traditional machining, such as: electrical discharge machining electrochemical machining laser and electron beam machining A chapter on biomedical machining is also included. This book is appropriate for advanced undergraduate and graduate mechani cal engineering students, manufacturing engineers, and researchers. Each chapter contains examples, exercises and their solutions, and homework problems that re...

Contribution of creatine kinase MB mass concentration at admission to early diagnosis of acute myocardial infarction

NARCIS (Netherlands)

Bakker, A. J.; Gorgels, J. P.; van Vlies, B.; Koelemay, M. J.; Smits, R.; Tijssen, J. G.; Haagen, F. D.

1994-01-01

OBJECTIVE: To assess the diagnostic value at admission of creatine kinase MB mass concentration, alone or in combination with electrocardiographic changes, in suspected myocardial infarction. DESIGN: Prospective study of all consecutive patients admitted within 12 hours after onset of chest pain to

MTX [Microwave Tokamak Experiment] plasma diagnostic system

International Nuclear Information System (INIS)

Rice, B.W.; Hooper, E.B.; Brooksby, C.A.

1987-01-01

In this paper, a general overview of the MTX plasma diagnostics system is given. This includes a description of the MTX machine configuration and the overall facility layout. The data acquisition system and techniques for diagnostic signal transmission are also discussed. In addition, the diagnostic instruments planned for both an initial ohmic-heating set and a second FEL-heating set are described. The expected range of plasma parameters along with the planned plasma measurements will be reviewed. 7 refs., 5 figs

Mechanical considerations for MFTF-B plasma-diagnostic system