Regional acetate kinetics and oxidation in human volunteers

1998 ◽  
Vol 274 (6) ◽  
pp. E978-E983 ◽  
Author(s):  
B. Mittendorfer ◽  
L. S. Sidossis ◽  
E. Walser ◽  
D. L. Chinkes ◽  
R. R. Wolfe
Keyword(s):  
Continuous Infusion ◽  
Whole Body ◽  
Acetate Metabolism ◽  
Human Volunteers ◽  
Percent Recovery ◽  
Carbon Recovery ◽  
Body Level ◽  
Uptake And Release

We have used a 3-h primed continuous infusion of [1,2-13C]acetate in five fasted (24 h) volunteers to quantify splanchnic and leg acetate metabolism ( protocol 1). Fractional extraction of acetate by both tissues was high (∼70%), and simultaneous uptake and release of acetate were observed. Labeled carbon recovery in CO2 was 37.9 ± 2.3% at the whole body level, 37.7 ± 1.5% across the splanchnic bed, and 37.3 ± 2.9% across the leg. Furthermore, we calculated whole body labeled carbon recovery during 15 h of [1,2-13C]acetate infusion in three volunteers ( protocol 2). Whole body acetate carbon recovery in CO2 was significantly higher (66.7 ± 4.5%) after 15 h of tracer infusion than after 3 h. We conclude that acetate is rapidly taken up by the leg and splanchnic tissues and that the percent recovery of CO2from the oxidation of acetate is heavily dependent on the length of acetate tracer infusion. In the postabsorptive state, labeled carbon recovery from acetate across the leg and the splanchnic region is similar to the whole body CO2 recovery.

Visualization of Invasion into the Body and Internal Diffusion of Nanoparticles

2008 ◽  
Vol 396-398 ◽  
pp. 569-572
Author(s):  
Fumio Watari ◽  
Shigeaki Abe ◽  
I.D. Rosca ◽  
Atsuro Yokoyama ◽  
Motohiro Uo ◽  
...  
Keyword(s):  
Biomedical Applications ◽  
Fluorescent Microscopy ◽  
The Body ◽  
Internal Diffusion ◽  
Whole Body ◽  
X Ray ◽  
Body Level ◽  
Organ Level ◽  
Level 2 ◽  
Internal Body

Nanoparticles may invade directly into the internal body through the respiratory or digestive system and diffuse inside body. The behavior of nanoparticles in the internal body is also essential to comprehend for the realization of DDS. Thus it is necessary to reveal the internal dynamics for the proper treatments and biomedical applications of nanoparticles. In the present study the plural methods with different principles such as X-ray scanning analytical microscope (XSAM), MRI and Fluorescent microscopy were applied to enable the observation of the internal diffusion of micro/nanoparticles in the (1) whole body level, (2) inner organ level and (3) tissue and intracellular level. Chemical analysis was also done by ICP-AES for organs and compared with the results of XSAM mapping.

Physiological and Perceptual Responses of Human Volunteers during Whole-Body RF Exposure at 450 MHz

1999 ◽  
pp. 613-616 ◽  
Author(s):  
Eleanor R. Adair ◽  
Sharon A. Kelleher ◽  
Larry G. Berglund ◽  
Gary W. Mack
Keyword(s):  
Whole Body ◽  
Rf Exposure ◽  
Human Volunteers

scholarly journals The Kidney Clock Contributes to Timekeeping by the Master Circadian Clock

2019 ◽  
Vol 20 (11) ◽  
pp. 2765 ◽  
Author(s):  
Jihwan Myung ◽  
Mei-Yi Wu ◽  
Chun-Ya Lee ◽  
Amalia Ridla Rahim ◽  
Vuong Hung Truong ◽  
...  
Keyword(s):  
Circadian Rhythms ◽  
Sleep Disturbances ◽  
The Body ◽  
Circadian Clocks ◽  
Whole Body ◽  
The Hierarchical Structure ◽  
Body Level ◽  
The Brain ◽  
Master Clock

The kidney harbors one of the strongest circadian clocks in the body. Kidney failure has long been known to cause circadian sleep disturbances. Using an adenine-induced model of chronic kidney disease (CKD) in mice, we probe the possibility that such sleep disturbances originate from aberrant circadian rhythms in kidney. Under the CKD condition, mice developed unstable behavioral circadian rhythms. When observed in isolation in vitro, the pacing of the master clock, the suprachiasmatic nucleus (SCN), remained uncompromised, while the kidney clock became a less robust circadian oscillator with a longer period. We find this analogous to the silencing of a strong slave clock in the brain, the choroid plexus, which alters the pacing of the SCN. We propose that the kidney also contributes to overall circadian timekeeping at the whole-body level, through bottom-up feedback in the hierarchical structure of the mammalian circadian clocks.

High temperature stress response is not sexually dimorphic at the whole-body level and is dependent on androgens to induce sex reversal

2020 ◽  
Vol 299 ◽  
pp. 113605
Author(s):  
Diana C. Castañeda-Cortés ◽  
Jing Zhang ◽  
Agustín F. Boan ◽  
Valerie S. Langlois ◽  
Juan I. Fernandino
Keyword(s):  
High Temperature ◽  
Stress Response ◽  
Temperature Stress ◽  
High Temperature Stress ◽  
Sex Reversal ◽  
Whole Body ◽  
Sexually Dimorphic ◽  
Body Level

Autoimmune disorder phenotypes in Hvcn1-deficient mice

2013 ◽  
Vol 450 (2) ◽  
pp. 295-301 ◽  
Author(s):  
Mari Sasaki ◽  
Akihiro Tojo ◽  
Yoshifumi Okochi ◽  
Nana Miyawaki ◽  
Daisuke Kamimura ◽  
...  
Keyword(s):  
T Cells ◽  
Autoimmune Disorder ◽  
Whole Body ◽  
Activated T Cells ◽  
Proton Channels ◽  
Voltage Gated ◽  
In The Wild ◽  
Body Level ◽  
Deficient Mice

Hv channels (voltage-gated proton channels) are expressed in blood cells, microglia and some types of epithelial cells. In neutrophils Hv channels regulate the production of reactive oxygen species through regulation of membrane potential and intracellular pH. Hv channels have also been suggested to play a role in sperm physiology in the human. However, the functions of the Hv channel at the whole-body level are not fully understood. In the present paper we show that Hvcn1 (voltage-gated hydrogen channel 1)-knockout mice show splenomegaly, autoantibodies and nephritis, that are reminiscent of human autoimmune diseases phenotypes. The number of activated T-cells was larger in Hvcn1-deficient mice than in the wild-type mice. Upon viral infection this was remarkably enhanced in Hvcn1-deficient mice. The production of superoxide anion in T-cells upon stimulation with PMA was significantly attenuated in the Hvcn1-deficient mice. These results suggest that Hv channels regulate T-cell homoeostasis in vivo.

Experimental analysis of critical oxygen delivery

2005 ◽  
Vol 288 (3) ◽  
pp. H1071-H1079 ◽  
Author(s):  
Ivo P. Torres Filho ◽  
Bruce D. Spiess ◽  
Roland N. Pittman ◽  
R. Wayne Barbee ◽  
Kevin R. Ward
Keyword(s):  
Cardiac Index ◽  
Multivariable Analysis ◽  
Systolic Pressure ◽  
Whole Body ◽  
Critical Levels ◽  
Dual Regression ◽  
Body Level ◽  
Multiple Variables ◽  
Systemic Variables ◽  
Stored Blood

Systemic variables were evaluated with respect to O2 delivery to test the hypothesis that critical O2 delivery and critical Hb can be estimated by multiple variables collected simultaneously. Rats were subjected to transfusion with either fresh or stored blood and then subjected to stepwise isovolemic hemodilution. Critical levels were measured by the dual-regression method from plots of systemic variables against O2 delivery and Hb. Delivery was calculated from cardiac index and arterial O2 content. We found that 1) after hemodilution, O2 delivery changed in a nonlinear relationship with Hb; 2) critical delivery calculated using 30 different systemic variables was not statistically different from each other; 3) critical delivery and critical Hb were correlated but were not different between animals receiving fresh or stored blood; and 4) similar critical levels were found using a single variable from several animals and using several variables from the same subject. The best variables to estimate critical delivery were lactate, bicarbonate, base excess, O2 extraction ratio, expired CO2, pulse pressure, cardiac index, and systolic pressure. The data suggest that a multivariable analysis of critical delivery may help determine the physiological oxygenation boundary at the whole body level. This may assist in finding therapeutic triggers on an individual basis using systemic markers of the transition from aerobic to anaerobic metabolism.

The Effects of Nutritional Supplementation Throughout an Endurance Run on Leucine Kinetics during Recovery

2007 ◽  
Vol 17 (5) ◽  
pp. 456-467 ◽  
Author(s):  
Sharon L. Miller ◽  
P. Courtney Gaine ◽  
Carl M. Maresh ◽  
Lawrence E. Armstrong ◽  
Cara B. Ebbeling ◽  
...  
Keyword(s):  
Continuous Infusion ◽  
Endurance Exercise ◽  
Protein Supplementation ◽  
Nutritional Supplementation ◽  
Whole Body ◽  
Protein Utilization ◽  
Leucine Kinetics ◽  
Mixed Protein

This study determined the effect of nutritional supplementation throughout endurance exercise on whole-body leucine kinetics (leucine rate of appearance [Ra], oxidation [Ox], and nonoxidative leucine disposal [NOLD]) during recovery. Five trained men underwent a 2-h run at 65% VO2max, during which a carbohydrate (CHO), mixed protein-carbohydrate (milk), or placebo (PLA) drink was consumed. Leucine kinetics were assessed during recovery using a primed, continuous infusion of 1-13C leucine. Leucine Ra and NOLD were lower for milk than for PLA. Ox was higher after milk-supplemented exercise than after CHO or PLA. Although consuming milk during the run affected whole-body leucine kinetics, the benefits of such a practice for athletes remain unclear. Additional studies are needed to determine whether protein supplementation during exercise can optimize protein utilization during recovery.

Responses to Nutrients in farm animals: implications for product quality

2007 ◽  
Vol 2007 ◽  
pp. 263-263
Author(s):  
J. F. Hocquette ◽  
S. Tesseraud ◽  
I. Cassar-Malek ◽  
C. Leroux
Keyword(s):  
Product Quality ◽  
Dairy Products ◽  
Farm Animals ◽  
Whole Body ◽  
Metabolic Efficiency ◽  
Food Markets ◽  
Animal Products ◽  
New Concepts ◽  
Body Level ◽  
Increasing Demand

In the context of increased globalisation and competitiveness, producers of animal products have been the most affected with considerable reductions in profit margins. Research on nutrition in farm animals is thus still needed to reduce the costs of production by increasing metabolic efficiency. To achieve this goal, the objective is always to control animal performance accurately by improved quantification of animal requirements and by precise feed evaluation. At the same time, the farming and agri-food sectors are faced with a general saturation of food markets in Europe and with an increasing demand by consumers for high-quality meat and dairy products. This has also led to specific research in nutrition which aims to optimise metabolic activity of muscle and mammary gland to produce meat and dairy products of the desirable composition. This paper aims to address this important question: how animal nutrition may help to optimise metabolic efficiency and product quality. Today this needs better knowledge of tissue and organ requirements and of nutrient fate within tissues and organs as well as of their contribution to the quality of animal products. Furthermore, in order to achieve this goal of greater understanding of animal response to nutrition, new concepts and techniques are available to decipher mechanisms that were impossible to address adequately a few years ago. In this connection, emerging approaches such as genomics and modelling provide the means for a better insight into the mechanisms which regulate metabolism at tissue or whole body level.

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