L-Carnitine Supplementation and Performance in Man

2015 ◽  
pp. 110-127 ◽  
Author(s):  
Anton J. M. Wagenmakers
Keyword(s):  
Carnitine Supplementation ◽  
And Performance

scholarly journals Influence of l-carnitine on metabolism and performance of sows

2009 ◽  
Vol 102 (5) ◽  
pp. 645-654 ◽  
Author(s):  
Klaus Eder
Keyword(s):  
Reproductive Performance ◽  
De Novo ◽  
Favourable Effect ◽  
Carnitine Supplementation ◽  
Suckling Period ◽  
Metabolic Requirement ◽  
Uterine Growth ◽  
Biochemical Mechanisms ◽  
And Performance ◽  
Oxidation Of Glucose

In recent years, l-carnitine has been used increasingly as a supplement in livestock animals. The present review gives an overview of the effects of dietary l-carnitine supplementation on the reproductive performance of sows. Results concerning the effect of l-carnitine supplementation during pregnancy on litter sizes are controversial. There are some studies reporting an increased number of piglets born alive per litter, while others could not find such an effect. In contrast, most studies performed show consistently that l-carnitine supplementation to a sow diet low in native carnitine during gestation increases piglet and litter weights at birth and enhances growth of litters during the suckling period. Biochemical mechanisms underlying the favourable effect of carnitine on intra-uterine growth have not been fully elucidated. There is, however, some evidence that carnitine influences the insulin-like growth factor-axis in sows and leads to greater placentae, which in turn improves intra-uterine nutrition, and stimulates oxidation of glucose in the fetuses. These effects may, at least in part, be responsible for higher birth weights of piglets. The stimulating effect of carnitine on growth of the litters might be due to an improved suckling behaviour of piglets born to l-carnitine-supplemented sows, causing the sows' milk production to rise. In conclusion, recent studies have clearly shown that dietary l-carnitine supplementation increases the reproductive performance of sows. These findings suggest that endogenous de novo synthesis of carnitine is insufficient to meet the metabolic requirement of sows during gestation.

L-carnitine supplementation improves fatigue, mood and sleep in cancer patients with fatigue and carnitine deficiency

2006 ◽  
Vol 24 (18_suppl) ◽  
pp. 8588-8588 ◽  
Author(s):  
R. A. Cruciani ◽  
E. Dvorkin ◽  
P. Homel ◽  
B. Culliney ◽  
S. Malamud ◽  
...  
Keyword(s):  
Performance Status ◽  
Serum Levels ◽  
Maximum Tolerated Dose ◽  
Carnitine Deficiency ◽  
Free Carnitine ◽  
Dependent Manner ◽  
Carnitine Supplementation ◽  
Karnofsky Score ◽  
Full Dataset ◽  
And Performance

8588 Background: Carnitine is a natural aminoacid derivative that plays a crucial role in cellular energy metabolism. To determine the dose and tolerability we conducted a phase II study with increasing doses of L-carnitine supplementation. In a preliminary analysis, we reported that L-carnitine could improve fatigue, mood and sleep. (Cruciani et al., 2004). Analysis of the full dataset has confirmed and extended these findings. Methods: Patients had active cancer, fatigue and a Karnofsky ≥50. Carnitine deficiency was defined as free carnitine <35 μm]/L for males and <25 for females (normal range 35–67 and 25–55 respectively), or a ratio of acyl/free carnitine >0.4. We utilized a standard maximum tolerated dose (MTD) design, with 3 patients assigned to each successive dose group, starting at 250 mg/day and increasing in each group by 500 mg/day to a maximum dose target of 3000 mg/day. Fatigue (measured by the BFI), depressed mood (CES-D), quality of sleep (ESS), and performance status (Karnofsky), as well as carnitine serum levels were assessed at baseline and after one week of L-carnitine supplementation. Results: Seven groups of three patients each received L-carnitine supplementation for a week with 250, 750, 1,250, 1,750, 2,250, 2,750 or 3,000 mg/day. Of the 27 patients accrued 21 completed the study. Of these, 17 (mean (SD) age = 63.0 (18), females=8) showed an increase in serum L-carnitine levels. The median (min, max) total carnitine increased from 31 (21, 68) to 51 (29, 111) (p < 0.001) and the free carnitine increased from 25.0 (17, 48) to 39 (25, 82) (p < 0.001). The median (min, max) BFI score at baseline was 63 (36, 81) versus 39 (8, 82) after one week (p<0.001). There was also a significant dose response for BFI (r = -0.61, p = 0.01). Median (min, max) CES-D at baseline was 31. (4, 48) and 18.0 (0, 40) after one-week (p = 0.001). Median (min, max) ESS at baseline was 13.7 (2, 22) and 10.3 (1, 18) after one week (p=0.003). Median Karnofsky score did not change (pre and post = 70). Side effects were not observed in any of the groups. Conclusions: This study suggests that L-carnitine is safe up to 3,000 mg/day. Supplementation was associated with improvements in fatigue and depression scores. Fatigue improved in a dose dependent manner. [Table: see text]

Transmission Scanning Electron Microscopy and Energy Analysis with the Siemens ELMISKOP 101

1972 ◽  
Vol 30 ◽  
pp. 450-451
Author(s):  
H. M. Thieringer
Keyword(s):  
Objective Lens ◽  
Transmission Microscopy ◽  
Image Recording ◽  
Mode Of Operation ◽  
Scanning Transmission ◽  
Electron Microscopes ◽  
And Performance ◽  
Convergent Beam ◽  
Ray Path ◽  
Beam Diffraction

It has repeatedly been show that with conventional electron microscopes very fine electron probes can be produced, therefore allowing various micro-techniques such as micro recording, X-ray microanalysis and convergent beam diffraction. In this paper the function and performance of an SIEMENS ELMISKOP 101 used as a scanning transmission microscope (STEM) is described. This mode of operation has some advantages over the conventional transmission microscopy (CTEM) especially for the observation of thick specimen, in spite of somewhat longer image recording times.Fig.1 shows schematically the ray path and the additional electronics of an ELMISKOP 101 working as a STEM. With a point-cathode, and using condensor I and the objective lens as a demagnifying system, an electron probe with a half-width ob about 25 Å and a typical current of 5.10-11 amp at 100 kV can be obtained in the back focal plane of the objective lens.

Angular Resolved Electron Spectroscopy with Parallel Recording

1990 ◽  
Vol 48 (2) ◽  
pp. 370-371
Author(s):  
Huang Min ◽  
P.S. Flora ◽  
C.J. Harland ◽  
J.A. Venables
Keyword(s):  
Electron Spectroscopy ◽  
Low Voltage ◽  
Solid Angle ◽  
Detection System ◽  
Voltage Electron ◽  
Cylindrical Mirror ◽  
Inner Radius ◽  
Channel Plate ◽  
And Performance ◽  
Type Detector

A cylindrical mirror analyser (CMA) has been built with a parallel recording detection system. It is being used for angular resolved electron spectroscopy (ARES) within a SEM. The CMA has been optimised for imaging applications; the inner cylinder contains a magnetically focused and scanned, 30kV, SEM electron-optical column. The CMA has a large inner radius (50.8mm) and a large collection solid angle (Ω > 1sterad). An energy resolution (ΔE/E) of 1-2% has been achieved. The design and performance of the combination SEM/CMA instrument has been described previously and the CMA and detector system has been used for low voltage electron spectroscopy. Here we discuss the use of the CMA for ARES and present some preliminary results.The CMA has been designed for an axis-to-ring focus and uses an annular type detector. This detector consists of a channel-plate/YAG/mirror assembly which is optically coupled to either a photomultiplier for spectroscopy or a TV camera for parallel detection.

Novel epoxy/anhydride alternatives for biological electron microscopy: Physical and performance characteristis of embed 812 and LX 112 in combination with NSA/NMA/DMAE

1989 ◽  
Vol 47 ◽  
pp. 1000-1001
Author(s):  
Joe A. Mascorro ◽  
Gerald S. Kirby
Keyword(s):  
Electron Microscopy ◽  
Flow Rate ◽  
Succinic Anhydride ◽  
Volume Flow Rate ◽  
Mass Density ◽  
Uranyl Acetate ◽  
Volume Flow ◽  
Base Resin ◽  
And Performance ◽  
Acid Anhydrides

Embedding media based upon an epoxy resin of choice and the acid anhydrides dodecenyl succinic anhydride (DDSA), nadic methyl anhydride (NMA), and catalyzed by the tertiary amine 2,4,6-Tri(dimethylaminomethyl) phenol (DMP-30) are widely used in biological electron microscopy. These media possess a viscosity character that can impair tissue infiltration, particularly if original Epon 812 is utilized as the base resin. Other resins that are considerably less viscous than Epon 812 now are available as replacements. Likewise, nonenyl succinic anhydride (NSA) and dimethylaminoethanol (DMAE) are more fluid than their counterparts DDSA and DMP- 30 commonly used in earlier formulations. This work utilizes novel epoxy and anhydride combinations in order to produce embedding media with desirable flow rate and viscosity parameters that, in turn, would allow the medium to optimally infiltrate tissues. Specifically, embeding media based on EmBed 812 or LX 112 with NSA (in place of DDSA) and DMAE (replacing DMP-30), with NMA remaining constant, are formulated and offered as alternatives for routine biological work.Individual epoxy resins (Table I) or complete embedding media (Tables II-III) were tested for flow rate and viscosity. The novel media were further examined for their ability to infilftrate tissues, polymerize, sectioning and staining character, as well as strength and stability to the electron beam and column vacuum. For physical comparisons, a volume (9 ml) of either resin or media was aspirated into a capillary viscocimeter oriented vertically. The material was then allowed to flow out freely under the influence of gravity and the flow time necessary for the volume to exit was recored (Col B,C; Tables). In addition, the volume flow rate (ml flowing/second; Col D, Tables) was measured. Viscosity (n) could then be determined by using the Hagen-Poiseville relation for laminar flow, n = c.p/Q, where c = a geometric constant from an instrument calibration with water, p = mass density, and Q = volume flow rate. Mass weight and density of the materials were determined as well (Col F,G; Tables). Infiltration schedules utilized were short (1/2 hr 1:1, 3 hrs full resin), intermediate (1/2 hr 1:1, 6 hrs full resin) , or long (1/2 hr 1:1, 6 hrs full resin) in total time. Polymerization schedules ranging from 15 hrs (overnight) through 24, 36, or 48 hrs were tested. Sections demonstrating gold interference colors were collected on unsupported 200- 300 mesh grids and stained sequentially with uranyl acetate and lead citrate.

Trace nanoanalysis

1994 ◽  
Vol 52 ◽  
pp. 940-941
Author(s):  
D. E. Newbury ◽  
R. D. Leapman
Keyword(s):  
High Performance ◽  
Secondary Ion Mass Spectrometry ◽  
Detection Efficiency ◽  
Volume Element ◽  
And Performance ◽  
Trace Constituents ◽  
Secondary Ion ◽  
Concentration Levels ◽  
Structure Properties

Trace constituents, which can be very loosely defined as those present at concentration levels below 1 percent, often exert influence on structure, properties, and performance far greater than what might be estimated from their proportion alone. Defining the role of trace constituents in the microstructure, or indeed even determining their location, makes great demands on the available array of microanalytical tools. These demands become increasingly more challenging as the dimensions of the volume element to be probed become smaller. For example, a cubic volume element of silicon with an edge dimension of 1 micrometer contains approximately 5×1010 atoms. High performance secondary ion mass spectrometry (SIMS) can be used to measure trace constituents to levels of hundreds of parts per billion from such a volume element (e. g., detection of at least 100 atoms to give 10% reproducibility with an overall detection efficiency of 1%, considering ionization, transmission, and counting).

Relationship of stress and performance among first-year dental students

1986 ◽  
Vol 50 (5) ◽  
pp. 264-267 ◽  
Author(s):  
GH Westerman ◽  
TG Grandy ◽  
JV Lupo ◽  
RE Mitchell
Keyword(s):  
Dental Students ◽  
First Year ◽  
And Performance ◽  
Relationship Of

Linguistic Competence in Aphasia

2008 ◽  
Vol 17 (3) ◽  
pp. 87-92
Author(s):  
Leonard L. LaPointe
Keyword(s):  
Language Use ◽  
Linguistic Competence ◽  
Careful Study ◽  
Feral Children ◽  
Performance Factors ◽  
Performance Loss ◽  
Linguistic Rules ◽  
Communication Goals ◽  
Aphasia Treatment ◽  
And Performance

Abstract Loss of implicit linguistic competence assumes a loss of linguistic rules, necessary linguistic computations, or representations. In aphasia, the inherent neurological damage is frequently assumed by some to be a loss of implicit linguistic competence that has damaged or wiped out neural centers or pathways that are necessary for maintenance of the language rules and representations needed to communicate. Not everyone agrees with this view of language use in aphasia. The measurement of implicit language competence, although apparently necessary and satisfying for theoretic linguistics, is complexly interwoven with performance factors. Transience, stimulability, and variability in aphasia language use provide evidence for an access deficit model that supports performance loss. Advances in understanding linguistic competence and performance may be informed by careful study of bilingual language acquisition and loss, the language of savants, the language of feral children, and advances in neuroimaging. Social models of aphasia treatment, coupled with an access deficit view of aphasia, can salve our restless minds and allow pursuit of maximum interactive communication goals even without a comfortable explanation of implicit linguistic competence in aphasia.

Sign in / Sign up

Export Citation Format

Share Document