Relation Between Contraction and Metabolic Efficiency

2020 ◽  
pp. 391-407
Author(s):  
Joseph Kedem ◽  
M. Scheinowitz ◽  
E. Furman ◽  
J. Sonn ◽  
H. R. Weiss
Keyword(s):  
Metabolic Efficiency

Microbial efficiency in a meromictic reservoir

2008 ◽  
Vol 37 (2) ◽  
Author(s):  
Grażyna Mazurkiewicz-Boroń ◽  
Teresa Bednarz ◽  
Elżbieta Wilk-Woźniak
Keyword(s):  
Carbon Dioxide ◽  
Oxygen Consumption ◽  
Release Rate ◽  
Oxygen Consumption Rate ◽  
Consumption Rate ◽  
Metabolic Efficiency ◽  
Sulphur Compounds ◽  
Carbon Dioxide Release ◽  
Microbial Efficiency ◽  
Ion Contents

Microbial efficiency in a meromictic reservoirIndices of microbial efficiency (expressed as oxygen consumption and carbon dioxide release) were determined in the water column of the meromictic Piaseczno Reservoir (in an opencast sulphur mine), which is rich in sulphur compounds. Phytoplankton abundances were low in both the mixolimnion (up to 15 m depth) and monimolimnion (below 15 m depth). In summer and winter, carbon dioxide release was 3-fold and 5-fold higher, respectively, in the monimolimnion than in the mixolimnion. Laboratory enrichments of the sulphur substrate of the water resulted in a decrease in oxygen consumption rate of by about 42% in mixolimnion samples, and in the carbon dioxide release rate by about 69% in monimolimnion samples. Water temperature, pH and bivalent ion contents were of major importance in shaping the microbial metabolic efficiency in the mixolimnion, whilst in the monimolimnion these relationships were not evident.

323 The Subcellular Expression Patterns of Bcl-Xl in Primary Brain Tumour Samples

2021 ◽  
Vol 108 (Supplement_2) ◽  
Author(s):  
A Vassiliou ◽  
K Alavian ◽  
M Tsujishita ◽  
H Bae
Keyword(s):  
Brain Tumour ◽  
Tumour Progression ◽  
Expression Patterns ◽  
B Cell Lymphoma ◽  
Nuclear Antigen ◽  
Future Research ◽  
Metabolic Efficiency ◽  
Cell Detection ◽  
Primary Brain Tumour ◽  
Cancerous Cells

Abstract Introduction Primary brain tumours originate from cells within the brain. The commonest malignant types are gliomas which are graded from I-IV. Emerging evidence has elucidated the function of the mitochondrially localised B-cell lymphoma-extra-large (Bcl-xL) protein, and its promotion of tumour progression-associated properties. Our lab has previously established that Bcl-xL-overexpressing neurons increase metabolic efficiency by producing more adenosine triphosphate and consuming less oxygen, which we assumed, fuels cancer cells to proliferate. Method We quantified the subcellular expression patterns of Bcl-xL in primary brain tumour samples through immunohistochemistry on a brain tissue microarray containing 16 glioma cases from Grades II-IV. We used antibodies against Bcl-xL, heat shock protein 60 for mitochondrial detection and proliferating cell nuclear antigen for cancerous cell detection. Results Bcl-xL is overexpressed in cancerous cells of Grade IV gliomas and is significantly greater than cancerous cells of Grade III and Grade II gliomas. Cancerous cells express higher levels of Bcl-xL than non-cancerous cells in all grades of glioma. Conclusions Bcl-xL-overexpressing neurons exhibit enhanced metabolic efficiency, contributing to increased proliferation rates. Future research should focus on the characterisation of ATP levels and oxygen consumption in glioma cells. Conclusively, pharmacological inhibition of Bcl-xL will suppress the proliferation rate in gliomas and cease cancer cell growth.

Reduced metabolic efficiency in patients with Crohn's disease

1993 ◽  
Vol 38 (11) ◽  
pp. 2001-2009 ◽  
Author(s):  
Manfred J. Müller ◽  
Lars U. Schmidt ◽  
Jürgen Körber ◽  
Alexander von Zur Mühlen ◽  
Helmuth Canzler ◽  
...  
Keyword(s):  
Crohn’S Disease ◽  
Crohn's Disease ◽  
Metabolic Efficiency

Transcriptional regulation of gene expression in human skeletal muscle during recovery from exercise

2000 ◽  
Vol 279 (4) ◽  
pp. E806-E814 ◽  
Author(s):  
Henriette Pilegaard ◽  
George A. Ordway ◽  
Bengt Saltin ◽  
P. Darrell Neufer
Keyword(s):  
Skeletal Muscle ◽  
Exercise Training ◽  
Human Skeletal Muscle ◽  
Molecular Mechanisms ◽  
Uncoupling Protein ◽  
Pyruvate Dehydrogenase Kinase ◽  
Heme Oxygenase 1 ◽  
Metabolic Efficiency ◽  
Vastus Lateralis Muscle ◽  
Mrna Levels

Exercise training elicits a number of adaptive changes in skeletal muscle that result in an improved metabolic efficiency. The molecular mechanisms mediating the cellular adaptations to exercise training in human skeletal muscle are unknown. To test the hypothesis that recovery from exercise is associated with transcriptional activation of specific genes, six untrained male subjects completed 60–90 min of exhaustive one-legged knee extensor exercise for five consecutive days. On day 5, nuclei were isolated from biopsies of the vastus lateralis muscle of the untrained and the trained leg before exercise and from the trained leg immediately after exercise and after 15 min, 1 h, 2 h, and 4 h of recovery. Transcriptional activity of the uncoupling protein 3 (UCP3), pyruvate dehydrogenase kinase 4 (PDK4), and heme oxygenase-1 (HO-1) genes (relative to β-actin) increased by three- to sevenfold in response to exercise, peaking after 1–2 h of recovery. Increases in mRNA levels followed changes in transcription, peaking between 2 and 4 h after exercise. Lipoprotein lipase and carnitine pamitoyltransferase I gene transcription and mRNA levels showed similar but less dramatic induction patterns, with increases ranging from two- to threefold. In a separate study, a single 4-h bout of cycling exercise ( n = 4) elicited from 5 to >20-fold increases in UCP3, PDK4, and HO-1 transcription, suggesting that activation of these genes may be related to the duration or intensity of exercise. These data demonstrate that exercise induces transient increases in transcription of metabolic genes in human skeletal muscle. Moreover, the findings suggest that the cumulative effects of transient increases in transcription during recovery from consecutive bouts of exercise may represent the underlying kinetic basis for the cellular adaptations associated with exercise training.

Dynamic regulation of metabolic efficiency explains tolerance to acute hypoxia in humans

2014 ◽  
Vol 28 (10) ◽  
pp. 4303-4311 ◽  
Author(s):  
Tomas A. Schiffer ◽  
Björn Ekblom ◽  
Jon O. Lundberg ◽  
Eddie Weitzberg ◽  
Filip J. Larsen
Keyword(s):  
Acute Hypoxia ◽  
Metabolic Efficiency ◽  
Dynamic Regulation

Lipid Dynamics during Reproduction in Two Livebearing Fishes, Gambusia holbrooki and Poecilia latipinna

1993 ◽  
Vol 50 (10) ◽  
pp. 2185-2191 ◽  
Author(s):  
Gary K. Meffe ◽  
Franklin F. Snelson Jr.
Keyword(s):  
Lipid Content ◽  
Energy Use ◽  
Late Summer ◽  
Energy Allocation ◽  
Metabolic Efficiency ◽  
Gambusia Holbrooki ◽  
Poecilia Latipinna ◽  
Lipid Dynamics ◽  
Sailfin Molly ◽  
Eastern Mosquitofish

In animals, strategies of energy allocation among growth, maintenance and reproduction can be significantly altered by lipid storage. Poeciliid (livebearing) fishes store energy in late summer and fall for overwintering and first reproduction in spring, but details of energy use in reproduction are lacking. We conducted a laboratory experiment on the eastern mosquitofish (Gambusia holbrooki) and the sailfin molly (Poecilia latipinna) to document changes in lipid content in both the ovary and soma during development of a brood. In females of both species, ovarian lipid content was highest early in embryogeny and then declined; adult somatic lipids increased (were replenished) during embryonic development in mosquitofish, but declined in mollies. Larger clutches sequestered a larger share of body lipids in both species, possibly indicating energetic limits to reproduction. Finally, growth rate was positively correlated with somatic lipid content in both species, indicating among-individual differences in metabolic efficiency or feeding efficiency rather than a trade-off between growth and energy storage.

scholarly journals Nutrition for Older Athletes: Focus on Sex-Differences

Nutrients ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 1409
Author(s):  
Barbara Strasser ◽  
Dominik Pesta ◽  
Jörn Rittweger ◽  
Johannes Burtscher ◽  
Martin Burtscher
Keyword(s):  
Sex Differences ◽  
Exercise Training ◽  
Role Model ◽  
Healthy Aging ◽  
Endurance Performance ◽  
Metabolic Efficiency ◽  
Older Athletes ◽  
Age Related ◽  
Masters Athletes ◽  
Physical Capacities

Regular physical exercise and a healthy diet are major determinants of a healthy lifespan. Although aging is associated with declining endurance performance and muscle function, these components can favorably be modified by regular physical activity and especially by exercise training at all ages in both sexes. In addition, age-related changes in body composition and metabolism, which affect even highly trained masters athletes, can in part be compensated for by higher exercise metabolic efficiency in active individuals. Accordingly, masters athletes are often considered as a role model for healthy aging and their physical capacities are an impressive example of what is possible in aging individuals. In the present review, we first discuss physiological changes, performance and trainability of older athletes with a focus on sex differences. Second, we describe the most important hormonal alterations occurring during aging pertaining regulation of appetite, glucose homeostasis and energy expenditure and the modulatory role of exercise training. The third part highlights nutritional aspects that may support health and physical performance for older athletes. Key nutrition-related concerns include the need for adequate energy and protein intake for preventing low bone and muscle mass and a higher demand for specific nutrients (e.g., vitamin D and probiotics) that may reduce the infection burden in masters athletes. Fourth, we present important research findings on the association between exercise, nutrition and the microbiota, which represents a rapidly developing field in sports nutrition.

scholarly journals Selection of drought tolerant wheat genotypes by osmotic stress imposed at germination and early seedling stage

2018 ◽  
Vol 15 (2) ◽  
pp. 177-192
Author(s):  
RR Saha ◽  
A Hannan ◽  
A Nessa ◽  
MA Malek ◽  
MR Islam
Keyword(s):  
Osmotic Stress ◽  
Dry Weight ◽  
Seedling Stage ◽  
Metabolic Efficiency ◽  
Wheat Genotypes ◽  
Shoot Dry Weight ◽  
Vigour Index ◽  
Peg Treatment ◽  
Early Seedling ◽  
Different Levels

An experiment on hundred wheat genotypes under different levels of osmotic stress was carried out during 2014 to select the genotype(s) tolerant to drought at germination and early seedling stage. Different levels of osmotic stress were imposed by using polyethylene glycol (PEG). Three osmotic stress levels viz. control (distilled water), 15% PEG solution and 25% PEG solution were used. Among the 100 genotypes the rate of germination percentage, final germination (%), root and shoot dry weight, amount of respiration and vigour index under PEG treatment was found significantly lower than that of control condition. Compared to control condition relative decrease in rate of germination, final germination, amount of respiration and vigour index among the wheat genotypes were found more at 25% PEG than that of 15% PEG treatment. However, the seed metabolic efficiency was significantly higher in wheat genotypes under both 15% PEG and 25% PEG treatment compared to the control condition. A significant positive correlation exists between the important growth parameters like rate of germination (%), final germination (%), shoot dry weight, root dry weight and vigour index. On the basis of these physiological traits against osmotic stress, nine genotypes of wheat such as BD-480, BD-498, BD- 501, BD-513, BD-514, BD-519, BD-592, BD-618 and BD- 633 were selected as drought tolerant.SAARC J. Agri., 15(2): 177-192 (2017)

scholarly journals Increased plasma leptin attenuates adaptive metabolism in early lactating dairy cows

2016 ◽  
Vol 229 (2) ◽  
pp. 145-157 ◽  
Author(s):  
Richard A Ehrhardt ◽  
Andreas Foskolos ◽  
Sarah L Giesy ◽  
Stephanie R Wesolowski ◽  
Christopher S Krumm ◽  
...  
Keyword(s):  
Dairy Cow ◽  
Feed Intake ◽  
Plasma Levels ◽  
Plasma Concentrations ◽  
Body Weight Loss ◽  
Energy Output ◽  
Glucose Disposal ◽  
Hepatic Glycogen ◽  
Metabolic Efficiency ◽  
Plasma Leptin

Mammals meet the increased nutritional demands of lactation through a combination of increased feed intake and a collection of adaptations known as adaptive metabolism (e.g., glucose sparing via insulin resistance, mobilization of endogenous reserves, and increased metabolic efficiency via reduced thyroid hormones). In the modern dairy cow, adaptive metabolism predominates over increased feed intake at the onset of lactation and develops concurrently with a reduction in plasma leptin. To address the role of leptin in the adaptive metabolism of early lactation, we asked which adaptations could be countered by a constant 96-h intravenous infusion of human leptin (hLeptin) starting on day 8 of lactation. Compared to saline infusion (Control), hLeptin did not alter energy intake or milk energy output but caused a modest increase in body weight loss. hLeptin reduced plasma glucose by 9% and hepatic glycogen content by 73%, and these effects were associated with a 17% increase in glucose disposal during an insulin tolerance test. hLeptin attenuated the accumulation of triglyceride in the liver by 28% in the absence of effects on plasma levels of the anti-lipolytic hormone insulin or plasma levels of free fatty acids, a marker of lipid mobilization from adipose tissue. Finally, hLeptin increased the plasma concentrations of T4and T3by nearly 50% without affecting other neurally regulated hormones (i.e., cortisol and luteinizing hormone (LH)). Overall these data implicate the periparturient reduction in plasma leptin as one of the signals promoting conservation of glucose and energy at the onset of lactation in the energy-deficient dairy cow.

scholarly journals Physiological Evidence for Isopotential Tunneling in the Electron Transport Chain of Methane-Producing Archaea

2017 ◽  
Vol 83 (18) ◽  
Author(s):  
Nikolas Duszenko ◽  
Nicole R. Buan
Keyword(s):  
Escherichia Coli ◽  
Electron Transport ◽  
Stationary Phase ◽  
Exponential Growth ◽  
Electron Transport Chain ◽  
Methanosarcina Barkeri ◽  
Metabolic Efficiency ◽  
Methanosarcina Acetivorans ◽  
Content Type ◽  
Transport Chain

ABSTRACT Many, but not all, organisms use quinones to conserve energy in their electron transport chains. Fermentative bacteria and methane-producing archaea (methanogens) do not produce quinones but have devised other ways to generate ATP. Methanophenazine (MPh) is a unique membrane electron carrier found in Methanosarcina species that plays the same role as quinones in the electron transport chain. To extend the analogy between quinones and MPh, we compared the MPh pool sizes between two well-studied Methanosarcina species, Methanosarcina acetivorans C2A and Methanosarcina barkeri Fusaro, to the quinone pool size in the bacterium Escherichia coli. We found the quantity of MPh per cell increases as cultures transition from exponential growth to stationary phase, and absolute quantities of MPh were 3-fold higher in M. acetivorans than in M. barkeri. The concentration of MPh suggests the cell membrane of M. acetivorans, but not of M. barkeri, is electrically quantized as if it were a single conductive metal sheet and near optimal for rate of electron transport. Similarly, stationary (but not exponentially growing) E. coli cells also have electrically quantized membranes on the basis of quinone content. Consistent with our hypothesis, we demonstrated that the exogenous addition of phenazine increases the growth rate of M. barkeri three times that of M. acetivorans. Our work suggests electron flux through MPh is naturally higher in M. acetivorans than in M. barkeri and that hydrogen cycling is less efficient at conserving energy than scalar proton translocation using MPh. IMPORTANCE Can we grow more from less? The ability to optimize and manipulate metabolic efficiency in cells is the difference between commercially viable and nonviable renewable technologies. Much can be learned from methane-producing archaea (methanogens) which evolved a successful metabolic lifestyle under extreme thermodynamic constraints. Methanogens use highly efficient electron transport systems and supramolecular complexes to optimize electron and carbon flow to control biomass synthesis and the production of methane. Worldwide, methanogens are used to generate renewable methane for heat, electricity, and transportation. Our observations suggest Methanosarcina acetivorans, but not Methanosarcina barkeri, has electrically quantized membranes. Escherichia coli, a model facultative anaerobe, has optimal electron transport at the stationary phase but not during exponential growth. This study also suggests the metabolic efficiency of bacteria and archaea can be improved using exogenously supplied lipophilic electron carriers. The enhancement of methanogen electron transport through methanophenazine has the potential to increase renewable methane production at an industrial scale.

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