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Sample records for basal metabolic rate

  1. Basal metabolic rate and the rate of senescence in the great tit

    NARCIS (Netherlands)

    Bouwhuis, Sandra; Sheldon, Ben C.; Verhulst, Simon; Koteja, Pawel

    2011-01-01

    1. Between-individual variation in rates of senescence has recently been found to relate to natal and early-life conditions in several natural populations. Mechanistic theories of senescence have predicted between-individual variation in basal metabolic rate (BMR) to also underlie such variation in

  2. Personality and basal metabolic rate in a wild bird population

    NARCIS (Netherlands)

    Bouwhuis, Sandra; Quinn, John L.; Sheldon, Ben C.; Verhulst, Simon

    2014-01-01

    Personality and metabolic rate are predicted to show covariance on methodological and functional grounds, but empirical studies at the individual level are rare, especially in natural populations. Here we assess the relationship between exploration behaviour, an important axis of personality, and ba

  3. Variation in energy intake and basal metabolic rate of a bird migrating in a wind tunnel

    NARCIS (Netherlands)

    Lindström, Å.; Klaassen, M.R.J.; Kvist, A.

    1999-01-01

    1. We studied the changes in body mass, metabolizable energy intake rate (ME) and basal metabolic rate (BMR) of a Thrush Nightingale, Luscinia luscinia, following repeated 12-h migratory flights in a wind tunnel. In total the bird flew for 176 h corresponding to 6300 km. This is the first study wher

  4. The Scaling of Maximum and Basal Metabolic Rates of Mammals and Birds

    CERN Document Server

    Barbosa, L A; Silva, J K L; Barbosa, Lauro A.; Garcia, Guilherme J. M.; Silva, Jafferson K. L. da

    2004-01-01

    Allometric scaling is one of the most pervasive laws in biology. Its origin, however, is still a matter of dispute. Recent studies have established that maximum metabolic rate scales with an exponent larger than that found for basal metabolism. This unpredicted result sets a challenge that can decide which of the concurrent hypotheses is the correct theory. Here we show that both scaling laws can be deduced from a single network model. Besides the 3/4-law for basal metabolism, the model predicts that maximum metabolic rate scales as $M^{6/7}$, maximum heart rate as $M^{-1/7}$, and muscular capillary density as $M^{-1/7}$, in agreement with data.

  5. Basal metabolic rate declines during long-distance migratory flight in great knots

    NARCIS (Netherlands)

    Battley, PF; Dekinga, A; Dietz, MW; Piersma, T; Tang, SX; Hulsman, K; Battley, Phil F.; Tang, Sixian

    2001-01-01

    Great Knots (Calidris tenuirostris) make one of the longest migratory flights in the avian world, flying almost 5500 km from Australia to China during northward migration. We measured basal metabolic rate (BMR) and body composition in birds before and after this flight and found that BMR decreased 4

  6. The relationship between basal metabolic rate and daily energy expenditure in birds and mammals

    NARCIS (Netherlands)

    Ricklefs, RE; Konarzewski, M; Daan, S

    1996-01-01

    We examined the relationship between daily energy expenditure (DEE) and basal metabolic rate (BMR) in birds and mammals. Two models of the relationship between DEE and BMR were distinguished: a ''shared pathways'' model in which DEE replaces BMR in the active organism and a ''partitioned pathways''

  7. Avian basal metabolic rates : their association with body composition and energy expenditure in nature

    NARCIS (Netherlands)

    Daan, Serge; Masman, Dirkjan; Groenewold, Alex

    1990-01-01

    Measurements of basal metabolic rate (BMR), body water, fat, and lean dry mass of different organs were obtained in 22 bird species, ranging from 10.8 to 1,253 g body mass. Residuals of BMR (after subtracting BMR allometrically predicted from body mass) were positively correlated with residuals of l

  8. Evolution of mitochondrial DNA and its relation to basal metabolic rate.

    Science.gov (United States)

    Feng, Ping; Zhao, Huabin; Lu, Xin

    2015-08-01

    Energy metabolism is essential for the survival of animals, which can be characterized by maximum metabolic rate (MMR) and basal metabolic rate (BMR). Because of the crucial roles of mitochondria in energy metabolism, mitochondrial DNA (mtDNA) has been subjected to stronger purifying selection in strongly locomotive than weakly locomotive birds and mammals. Although maximum locomotive speed (an indicator of MMR) showed a negative correlation with the evolutionary rate of mtDNA, it is unclear whether BMR has driven the evolution of mtDNA. Here, we take advantage of the large amount of mtDNA and BMR data in 106 mammals to test whether BMR has influenced the mtDNA evolution. Our results showed that, in addition to the locomotive speed, mammals with higher BMR have subjected to stronger purifying selection on mtDNA than did those with lower BMR. The evolution of mammalian mtDNA has been modified by two levels of energy metabolism, including MMR and BMR. Our study provides a more comprehensive view of mtDNA evolution in relation to energy metabolism.

  9. A strong response to selection on mass-independent maximal metabolic rate without a correlated response in basal metabolic rate

    DEFF Research Database (Denmark)

    Wone, B W M; Madsen, Per; Donovan, E R;

    2015-01-01

    Metabolic rates are correlated with many aspects of ecology, but how selection on different aspects of metabolic rates affects their mutual evolution is poorly understood. Using laboratory mice, we artificially selected for high maximal mass-independent metabolic rate (MMR) without direct selecti...

  10. The effect of long term combined yoga practice on the basal metabolic rate of healthy adults

    Directory of Open Access Journals (Sweden)

    Nagendra HR

    2006-08-01

    Full Text Available Abstract Background Different procedures practiced in yoga have stimulatory or inhibitory effects on the basal metabolic rate when studied acutely. In daily life however, these procedures are usually practiced in combination. The purpose of the present study was to investigate the net change in the basal metabolic rate (BMR of individuals actively engaging in a combination of yoga practices (asana or yogic postures, meditation and pranayama or breathing exercises for a minimum period of six months, at a residential yoga education and research center at Bangalore. Methods The measured BMR of individuals practicing yoga through a combination of practices was compared with that of control subjects who did not practice yoga but led similar lifestyles. Results The BMR of the yoga practitioners was significantly lower than that of the non-yoga group, and was lower by about 13 % when adjusted for body weight (P Conclusion This study shows that there is a significantly reduced BMR, probably linked to reduced arousal, with the long term practice of yoga using a combination of stimulatory and inhibitory yogic practices.

  11. Testosterone effects on avian basal metabolic rate and aerobic performance: facts and artefacts.

    Science.gov (United States)

    Buttemer, W A; Warne, S; Bech, C; Astheimer, L B

    2008-06-01

    We examined the effects of cage size and testosterone (T) levels on basal and peak metabolic rates (BMR and PMR, respectively) and on pectoral and leg muscle masses of male house sparrows (Passer domesticus). Birds were housed either in small birdcages or in flight aviaries for at least 2 weeks prior to the initial metabolic evaluations. They were then implanted with either empty or T-filled silastic capsules and remeasured 5-6 weeks later. Birds treated with single T implants achieved breeding levels (4-6 ng/mL) and one group given double implants reached 10 ng/mL. There was no effect of T on BMR or PMR in any group studied, but there was an effect of caging. Caged birds showed significant reductions in PMR over the course of captivity, whereas PMR in aviary-housed birds were indistinguishable from their free-living counterparts. Testosterone treatment significantly increased leg muscle mass in caged birds, but had no effect on muscle mass in aviary-housed sparrows. We conclude that testosterone has no direct effect on sparrow metabolic rate or muscle mass, but may interact with cage conditions to produce indirect changes to these variables.

  12. Basal metabolic rate in carnivores is associated with diet after controlling for phylogeny.

    Science.gov (United States)

    Munoz-Garcia, Agusti; Williams, Joseph B

    2005-01-01

    Studies of basal metabolic rate (BMR), the minimum metabolic rate of postabsorptive, inactive endotherms while in their rest phase and thermal neutral zone, have contributed significantly to our understanding of animal energetics. Besides body mass, the main determinant of BMR, researchers have invoked diet and phylogenetic history as important factors that influence BMR, although their relative importance has been controversial. For 58 species within the Carnivora, we tested the hypothesis that BMR is correlated with home range size, a proxy for level of activity, and diet, using conventional least squares regression (CLSR) and regression based on phylogenetic independent contrasts (PIC). Results showed that BMR of Carnivora was positively correlated with home range size after controlling for body mass, regardless of the statistical method employed. We also found that diet and mass-adjusted home range size were correlated. When we simultaneously tested the effect of diet and mass-adjusted home range on mass-adjusted BMR, home range size was insignificant because of its colinearity with diet. Then we eliminated home range size from our model, and diet proved to be significant with both CLSR and PIC. We concluded that species that eat meat have larger home ranges and higher BMR than species that eat vegetable matter. To advance our understanding of the potential mechanisms that might explain our results, we propose the "muscle performance hypothesis," which suggests that selection for different muscle fiber types can account for the differences in BMR observed between meat eaters and vegetarian species within the Carnivora.

  13. Vitamin C improves basal metabolic rate and lipid profile in alloxan-induced diabetes mellitus in rats

    Indian Academy of Sciences (India)

    D U Owu; A B Antai; K H Udofia; A O Obembe; K O Obasi; M U Eteng

    2006-12-01

    Diabetes mellitus (DM) is a multi-factorial disease which is characterized by hyperglycaemia, lipoprotein abnormalities and oxidative stress. This study evaluated effect of oral vitamin C administration on basal metabolic rate and lipid profile of alloxan-induced diabetic rats. Vitamin C was administered at 200 mg/kg body wt. by gavage for four weeks to diabetic rats after which the resting metabolic rate and plasma lipid profile was determined. The results showed that vitamin C administration significantly ( < 0.01) reduced the resting metabolic rate in diabetic rats; and also lowered plasma triglyceride, total cholesterol and low-density lipoprotein cholesterol. These results suggest that the administration of vitamin C in this model of established diabetes mellitus might be beneficial for the restoration of basal metabolic rate and improvement of lipid profile. This may at least in part reduce the risk of cardiovascular events seen in diabetes mellitus.

  14. Thermal conductance and basal metabolic rate are part of a coordinated system for heat transfer regulation.

    Science.gov (United States)

    Naya, Daniel E; Spangenberg, Lucía; Naya, Hugo; Bozinovic, Francisco

    2013-09-22

    Thermal conductance measures the ease with which heat leaves or enters an organism's body. Although the analysis of this physiological variable in relation to climatic and ecological factors can be traced to studies by Scholander and colleagues, only small advances have occurred ever since. Here, we analyse the relationship between minimal thermal conductance estimated during summer (Cmin) and several ecological, climatic and geographical factors for 127 rodent species, in order to identify the exogenous factors that have potentially affected the evolution of thermal conductance. In addition, we evaluate whether there is compensation between Cmin and basal metabolic rate (BMR)-in such a way that a scale-invariant ratio between both variables is equal to one-as could be expected from the Scholander-Irving model of heat transfer. Our major findings are (i) annual mean temperature is the best single predictor of mass-independent Cmin. (ii) After controlling for the effect of body mass, there is a strong positive correlation between log10 (Cmin) and log10 (BMR). Further, the slope of this correlation is close to one, indicating an almost perfect compensation between both physiological variables. (iii) Structural equation modelling indicated that Cmin values are adjusted to BMR values and not the other way around. Thus, our results strongly suggest that BMR and thermal conductance integrate a coordinated system for heat regulation in endothermic animals and that summer conductance values are adjusted (in an evolutionary sense) to track changes in BMRs.

  15. Basal metabolic rate and body composition of elite Japanese male athletes.

    Science.gov (United States)

    Koshimizu, Takako; Matsushima, Yoshiko; Yokota, Yukari; Yanagisawa, Kae; Nagai, Satsuki; Okamura, Koji; Komatsu, Yutaka; Kawahara, Takashi

    2012-01-01

    The estimated energy requirement is important for adequate nutritional management in athletes. The energy requirement can be estimated from the basal metabolic rate (BMR). However, there is little data regarding the BMR of Japanese athletes. This study measured the BMR and body composition of 81 elite Japanese male athletes in different sports categories: endurance (E), strength, power and sprint (S) and ball game (B). The factors influencing the BMR were also investigated. The BMR and body composition were measured by indirect calorimetry and an air-displacement plentysmograph device (the BOD POD), respectively. The BMR per lean body mass (LBM) differed significantly among the three groups. The BMR was significantly correlated with the body weight (BW) and LBM in all groups. A multiple-regression analysis showed that the LBM was the most powerful predictor in the E and S groups, whereas the BW was the most powerful predictor in the B group. The BW appears to become an important predictor as the BW of athletes increases. Additionally, height was the second explanatory variable in the S and B groups, thus suggesting that height needs to be considered for the BMR in these groups. Therefore, the BMR in elite athletes needs to be estimated according to their body composition.

  16. Diet affects resting, but not basal metabolic rate of normothermic Siberian hamsters acclimated to winter.

    Science.gov (United States)

    Gutowski, Jakub P; Wojciechowski, Michał S; Jefimow, Małgorzata

    2011-12-01

    We examined the effect of different dietary supplements on seasonal changes in body mass (m(b)), metabolic rate (MR) and nonshivering thermogenesis (NST) capacity in normothermic Siberian hamsters housed under semi-natural conditions. Once a week standard hamster food was supplemented with either sunflower and flax seeds, rich in polyunsaturated fatty acids (FA), or mealworms, rich in saturated and monounsaturated FA. We found that neither of these dietary supplements affected the hamsters' normal winter decrease in m(b) and fat content nor their basal MR or NST capacity. NST capacity of summer-acclimated hamsters was lower than that of winter-acclimated ones. The composition of total body fat reflected the fat composition of the dietary supplements. Resting MR below the lower critical temperature of the hamsters, and their total serum cholesterol concentration were lower in hamsters fed a diet supplemented with mealworms than in hamsters fed a diet supplemented with seeds. These results indicate that in mealworm-fed hamsters energy expenditure in the cold is lower than in animals eating a seed-supplemented diet, and that the degree of FA unsaturation of diet affects energetics of heterotherms, not only during torpor, but also during normothermy.

  17. Basal metabolic rate and body fatness of adult men in northern Mexico.

    Science.gov (United States)

    Valencia, M E; Moya, S Y; McNeill, G; Haggarty, P

    1994-03-01

    To investigate the possibility that overprediction of basal metabolic rate (BMR) of tropical populations is related to differences in fatness between tropical and temperate populations, 32 Mexican men aged 18-40 years underwent measurements of BMR and body fat content. The men were divided into four body mass index (BMI) groups (FAO/WHO/UNU (1985) equations. The FAO/WHO/UNU equations overestimated measured BMR by 9.8%, 9.6%, 7.8% and 5.5% in the four groups. The overall difference was 8.2%, which was statistically significant (P < 0.001). The intercepts of the two equations were significantly different (P < 0.001) by 532 kJ/day, but there was no significant difference between the slopes of the two regression equations. There was no significant difference between BMR/kg fat-free mass in the four BMI groups. The results therefore do not support the possibility that the overprediction of BMR in tropical populations by international prediction equations based on body weight is accounted for by differences in fatness between tropical and temperate populations.

  18. Flexibility in basal metabolic rate and evaporative water loss among hoopoe larks exposed to different environmental temperatures

    NARCIS (Netherlands)

    Williams, JB; Tieleman, BI

    2000-01-01

    The 'energy demand' hypothesis for short-term adjustments in basal metabolic rate (BMR) posits that birds adjust the size of their internal organs relative to food intake, a correlate of energy demand, We tested this hypothesis on hoopoe larks (Alaemon alaudipes), inhabitants of the Arabian desert,

  19. Exploring individual quality: Basal metabolic rate and reproductive performance in storm-petrels

    Science.gov (United States)

    Blackmer, A.L.; Mauck, R.A.; Ackerman, J.T.; Huntington, C.E.; Nevitt, G.A.; Williams, J.B.

    2005-01-01

    Despite evidence that some individuals achieve both superior reproductive performance and high survivorship, the factors underlying variation in individual quality are not well understood. The compensation and increased-intake hypotheses predict that basal metabolic rate (BMR) influences reproductive performance; if so, variation in BMR may be related to differences in individual quality. We evaluated whether BMR measured during the incubation period provides a proximate explanation for variation in individual quality by measuring the BMRs and reproductive performance of Leach's storm-petrels (Oceanodroma leucorhoa) breeding on Kent Island, New Brunswick, Canada, during 2000 and 2001. We statistically controlled for internal (body mass, breeding age, sex) and external (year, date, time of day) effects on BMR. We found that males with relatively low BMRs hatched their eggs earlier in the season and that their chicks' wing growth rates were faster compared to males with relatively high BMRs. Conversely, BMR was not related to egg volume, hatching date, or chick growth rate for females or to lifetime (???23 years) hatching success for either sex. Thus, for males but not for females, our results support the compensation hypothesis. This hypothesis predicts that animals with low BMRs will achieve better reproductive performance than animals with high BMRs because they have lower self-maintenance costs and therefore can apportion more energy to reproduction. These results provide evidence that intraspecific variation in reproductive performance is related to BMR and suggest that BMR may influence individual quality in males. ?? The Author 2005. Published by Oxford University Press on behalf of the International Society for Behavioral Ecology. All rights reserved.

  20. Uniformity in the basal metabolic rate of marsupials: its causes and consequences Uniformidad en la tasa metabólica basal de marsupiales: sus causas y consecuencias

    Directory of Open Access Journals (Sweden)

    BRIAN K. MACNAB

    2005-06-01

    Full Text Available Most of the variation (98.8 % in basal rate of metabolism (BMR in 70 species of marsupials is correlated with body mass, although lowland species have higher basal rates than highland species and burrowers have lower basal rates than non-burrowers. These factors collectively account for 99.2 % of the variation in marsupial BMR. Marsupials differ in BMR from eutherians by having no species with a high basal rate by general mammalian standards, even when consuming vertebrates or grass, food habits that are associated with very high basal rates in eutherians. The absence of high basal rates in marsupials reflects the absence of a correlation of rate of reproduction with basal rate, a correlation present in eutherians. These differences have two consequences: (1 marsupials are less tolerant of cold environments than eutherians, and (2 marsupials coexist with eutherians only when both have food habits associated with low basal rates and therefore when eutherians have reduced rates of reproduction. In Australia and South America marsupial carnivores diversified in the absence of eutherian equivalents. The importation to mainland Australia of dingos by humans appears to have been the immediate cause for the extinction of thylacines, Tasmanian devils, and eastern quolls. Carnivorous marsupials in South America were replaced by eutherians with the completion of the Panamanian land bridge. Macropods, which have lower basal rates than eutherian grazers, survive in central Australia probably because of their adjustment to xeric environments, whereas introduced domestic stock require the provision of water by humansGran parte de la variación (98,5 en la tasa metabólica basal de 70 especies de marsupiales se correlaciona con la masa corporal, aunque las especies de tierras bajas tienes tasas basales mayores que las de tierras altas, y las especies subterráneas tienes BMR’s menores que las no subterráneas. Colectivamente, estos factores dan cuenta de un

  1. Temperature-induced elevation of basal metabolic rate does not affect testis growth in great tits.

    Science.gov (United States)

    Caro, Samuel P; Visser, Marcel E

    2009-07-01

    The timing of reproduction varies from year to year in many bird species. To adjust their timing to the prevailing conditions of that year, birds use cues from their environment. However, the relative importance of these cues, such as the initial predictive (e.g. photoperiod) and the supplemental factors (e.g. temperature), on the seasonal sexual development are difficult to distinguish. In particular, the fine-tuning effect of temperature on gonadal growth is not well known. One way temperature may affect timing is via its strong effect on energy expenditure as gonadal growth is an energy-demanding process. To study the interaction of photoperiod and temperature on gonadal development, we first exposed 35 individually housed male great tits (Parus major) to mid-long days (after 6 weeks of 8 h L:16 h D at 15 degrees C, photoperiod was set to 13 h L:11 h D at 15 degrees C). Two weeks later, for half of the males the temperature was set to 8 degrees C, and for the other half to 22 degrees C. Unilateral laparotomies were performed at weeks 5 (i.e one week before the birds were transferred to mid-long days), 8 and 11 to measure testis size. Two measures of basal metabolic rate (BMR) were performed at the end of the experiment (weeks 11 and 12). Testis size increased significantly during the course of the experiment, but independently of the temperature treatment. BMR was significantly higher in birds exposed to the cold treatment. These results show that temperature-related elevation of BMR did not impair the long-day-induced testis growth in great tits. As a consequence, temperature may not be a crucial cue and/or constraint factor in the fine-tuning of the gonadal recrudescence in male great tits, and testis growth is not a high energy-demanding seasonal process.

  2. Exploration of Energy Metabolism in the Mouse Using Indirect Calorimetry: Measurement of Daily Energy Expenditure (DEE) and Basal Metabolic Rate (BMR).

    Science.gov (United States)

    Meyer, Carola W; Reitmeir, Peter; Tschöp, Matthias H

    2015-09-01

    Current comprehensive mouse metabolic phenotyping involves studying energy balance in cohorts of mice via indirect calorimetry, which determines heat release from changes in respiratory air composition. Here, we describe the measurement of daily energy expenditure (DEE) and basal metabolic rate (BMR) in mice. These well-defined metabolic descriptors serve as meaningful first-line read-outs for metabolic phenotyping and should be reported when exploring energy expenditure in mice. For further guidance, the issue of appropriate sample sizes and the frequency of sampling of metabolic measurements is also discussed.

  3. Intraspecific correlations of basal and maximal metabolic rates in birds and the aerobic capacity model for the evolution of endothermy.

    Directory of Open Access Journals (Sweden)

    David L Swanson

    Full Text Available The underlying assumption of the aerobic capacity model for the evolution of endothermy is that basal (BMR and maximal aerobic metabolic rates are phenotypically linked. However, because BMR is largely a function of central organs whereas maximal metabolic output is largely a function of skeletal muscles, the mechanistic underpinnings for their linkage are not obvious. Interspecific studies in birds generally support a phenotypic correlation between BMR and maximal metabolic output. If the aerobic capacity model is valid, these phenotypic correlations should also extend to intraspecific comparisons. We measured BMR, M(sum (maximum thermoregulatory metabolic rate and MMR (maximum exercise metabolic rate in a hop-flutter chamber in winter for dark-eyed juncos (Junco hyemalis, American goldfinches (Carduelis tristis; M(sum and MMR only, and black-capped chickadees (Poecile atricapillus; BMR and M(sum only and examined correlations among these variables. We also measured BMR and M(sum in individual house sparrows (Passer domesticus in both summer, winter and spring. For both raw metabolic rates and residuals from allometric regressions, BMR was not significantly correlated with either M(sum or MMR in juncos. Moreover, no significant correlation between M(sum and MMR or their mass-independent residuals occurred for juncos or goldfinches. Raw BMR and M(sum were significantly positively correlated for black-capped chickadees and house sparrows, but mass-independent residuals of BMR and M(sum were not. These data suggest that central organ and exercise organ metabolic levels are not inextricably linked and that muscular capacities for exercise and shivering do not necessarily vary in tandem in individual birds. Why intraspecific and interspecific avian studies show differing results and the significance of these differences to the aerobic capacity model are unknown, and resolution of these questions will require additional studies of potential

  4. Thermodynamic Significance of Human Basal Metabolism

    Institute of Scientific and Technical Information of China (English)

    WangCuncheng

    1993-01-01

    The human basal state,a non-equilibrium steady state,is analysed in this paper in the light of the First and Second Laws of Thermodynamics whereby the thermodynamic significance of the basal metabolic rate and its distinction to the dissipation function and exergy loss are identified.The analysis demonstrates the correct expression of the effects of the blood flow on the heat balance in a human-body bio-heat model and the relationship between the basal metabolic rate and the blood perfusion.

  5. Compilation of basal metabolic and blood perfusion rates in various multi-compartment, whole-body thermoregulation models

    Science.gov (United States)

    Shitzer, Avraham; Arens, Edward; Zhang, Hui

    2016-07-01

    The assignments of basal metabolic rates (BMR), basal cardiac output (BCO), and basal blood perfusion rates (BBPR) were compared in nine multi-compartment, whole-body thermoregulation models. The data are presented at three levels of detail: total body, specific body regions, and regional body tissue layers. Differences in the assignment of these quantities among the compared models increased with the level of detail, in the above order. The ranges of variability in the total body BMR was 6.5 % relative to the lowest value, with a mean of 84.3 ± 2 W, and in the BCO, it was 8 % with a mean of 4.70 ± 0.13 l/min. The least variability among the body regions is seen in the combined torso (shoulders, thorax, and abdomen: ±7.8 % BMR and ±5.9 % BBPR) and in the combined head (head, face, and neck ±9.9 % BMR and ±10.9 % BBPR), determined by the ratio of the standard deviation to the mean. Much more variability is apparent in the extremities with the most showing in the BMR of the feet (±117 %), followed by the BBPR in the arms (±61.3 %). In the tissue layers, most of the bone layers were assigned zero BMR and BBPR, except in the shoulders and in the extremities that were assigned non-zero values in a number of models. The next lowest values were assigned to the fat layers, with occasional zero values. Skin basal values were invariably non-zero but involved very low values in certain models, e.g., BBPR in the feet and the hands. Muscle layers were invariably assigned high values with the highest found in the thorax, abdomen, and legs. The brain, lung, and viscera layers were assigned the highest of all values of both basal quantities with those of the brain layers showing rather tight ranges of variability in both basal quantities. Average basal values of the "time-seasoned" models presented in this study could be useful as a first step in future modeling efforts subject to appropriate adjustment of values to conform to most recently available and reliable data.

  6. Cell size and basal metabolic rate in hummingbirds Tamaño celular y tasa metabólica basal en picaflores

    Directory of Open Access Journals (Sweden)

    Juan C. Opazo

    2005-06-01

    Full Text Available Nucleotypic theory suggests that genome size play indirect roles in determining organismal fitness. Among endotherms this theory has been demonstrated by an inverse correlation between basal metabolic rate (BMR and genome size. Nonetheless, accumulation of variables, especially for some key groups of endotherms, involved in C-value enigma (e.g., cell size will fortify this theory. In this sense, hummingbird species are of particular interest because they are an energetic extreme in avian and endotherm evolution. Knowing that cell size is proportional to C-value, in this study we tested for a relationship between mean corpuscular volume of red blood cells and BMR in four species of hummingbirds ranging from 4 to 20 g. In comparison with other birds, our hummingbird data show higher BMR and the smallest mean corpuscular volumes, thereby providing further support for the nucleotypic theoryLa teoría nucleotípica sugiere que el tamaño del genoma juega un rol indirecto en la adecuación biológica, a través de las variables con las que se relaciona. En endotermos esta teoría ha sido demostrada por la relación inversa entre la tasa metabólica basal y el tamaño del genoma. La acumulación de variables, en grupos claves de endotermos, relacionadas con esta problemática (e.g., tamaño celular son ideales para poner a prueba esta teoría. En este sentido, los picaflores son de particular interés ya que son el extremo energético dentro de los endotermos. Sabiendo que el tamaño celular es proporcional al tamaño del genoma, en este trabajo ponemos a prueba la relación del volumen corpuscular medio y la tasa metabólica basal, e indirectamente el tamaño del genoma, en cuatro especies de picaflores con masas corporales que van desde 4 a 20 g. Los datos de metabolismo mostraron estar dentro de los mayores descritos para aves, asimismo, los tamaños de los eritrocitos fueron los más pequeños dentro de los valores reportados en la literatura

  7. A 'slow pace of life' in Australian old-endemic passerine birds is not accompanied by low basal metabolic rates.

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    Bech, Claus; Chappell, Mark A; Astheimer, Lee B; Londoño, Gustavo A; Buttemer, William A

    2016-05-01

    Life history theory suggests that species experiencing high extrinsic mortality rates allocate more resources toward reproduction relative to self-maintenance and reach maturity earlier ('fast pace of life') than those having greater life expectancy and reproducing at a lower rate ('slow pace of life'). Among birds, many studies have shown that tropical species have a slower pace of life than temperate-breeding species. The pace of life has been hypothesized to affect metabolism and, as predicted, tropical birds have lower basal metabolic rates (BMR) than temperate-breeding birds. However, many temperate-breeding Australian passerines belong to lineages that evolved in Australia and share 'slow' life-history traits that are typical of tropical birds. We obtained BMR from 30 of these 'old-endemics' and ten sympatric species of more recently arrived passerine lineages (derived from Afro-Asian origins or introduced by Europeans) with 'faster' life histories. The BMR of 'slow' temperate-breeding old-endemics was indistinguishable from that of new-arrivals and was not lower than the BMR of 'fast' temperate-breeding non-Australian passerines. Old-endemics had substantially smaller clutches and longer maximal life spans in the wild than new arrivals, but neither clutch size nor maximum life span was correlated with BMR. Our results suggest that low BMR in tropical birds is not functionally linked to their 'slow pace of life' and instead may be a consequence of differences in annual thermal conditions experienced by tropical versus temperate species.

  8. Basal metabolic rate, food intake, and body mass in cold- and warm-acclimated Garden Warblers

    NARCIS (Netherlands)

    Klaassen, M.R.J.; Oltrogge, M.; Trost, L.

    2004-01-01

    We address the question of whether physiological flexibility in relation to climate is a general feature of the metabolic properties of birds. We tested this hypothesis in hand-raised Garden Warblers (Sylvia borin), long-distance migrants, which normally do not experience great temperature differenc

  9. Do great tits (Parus major) suppress basal metabolic rate in response to increased perceived predation danger? A field experiment.

    Science.gov (United States)

    Mathot, Kimberley J; Abbey-Lee, Robin N; Kempenaers, Bart; Dingemanse, Niels J

    2016-10-01

    Several studies have shown that individuals with higher metabolic rates (MRs) feed at higher rates and are more willing to forage in the presence of predators. This increases the acquisition of resources, which in turn, may help to sustain a higher MR. Elevated predation danger may be expected to result in reduced MRs, either as a means of allowing for reduced feeding and risk-taking, or as a consequence of adaptively reducing intake rates via reduced feeding and/or risk-taking. We tested this prediction in free-living great tits (Parus major) using a playback experiment to manipulate perceived predation danger. There was evidence that changes in body mass and BMR differed as a function of treatment. In predator treatment plots, great tits tended to reduce their body mass, a commonly observed response in birds to increased predation danger. In contrast, birds from control treatment plots showed no overall changes in body mass. There was also evidence that great tits from control treatment plots increased their basal metabolic rate (BMR) over the course of the experiment, presumably due to decreasing ambient temperatures over the study period. However, there was no evidence for changes in BMR for birds from predator treatment plots. Although the directions of these results are consistent with the predicted directions of effects, the effects sizes and confidence intervals yield inconclusive support for the hypothesis that great tits would adaptively suppress BMR in response to increased perceived predation risk. The effect size observed in the present study was small (~1%) and would not be expected to result in substantive reductions in feeding rate and/or risk-taking. Whether or not ecological conditions that generate greater energetic stress (e.g. lower food availability, lower ambient temperatures) could produce an effect that produces biologically meaningful reductions in feeding activity and/or risk-taking remains an open question.

  10. Aging-Related Correlation between Serum Sirtuin 1 Activities and Basal Metabolic Rate in Women, but not in Men

    Science.gov (United States)

    2017-01-01

    Sirtuin (SIRT) is a main regulator of metabolism and lifespan, and its importance has been implicated in the prevention against aging-related diseases. The purpose of this study was to identify the pattern of serum SIRT1 activity according to age and sex, and to investigate how serum SIRT1 activity is correlated with other metabolic parameters in Korean adults. The Biobank of Jeju National University Hospital, a member of the Korea Biobank Network, provided serum samples from 250 healthy adults. Aging- and metabolism-related factors were analyzed in serum, and the data were compared by the stratification of age and sex. Basal metabolic rate (BMR) decreased with age and was significantly lower in men in their fifties and older and in women in their forties and older compared with twenties in men and women, respectively. SIRT1 activities were altered by age and sex. Especially, women in their thirties showed the highest SIRT1 activities. Correlation analysis displayed that SIRT1 activity is positively correlated with serum triglyceride (TG) in men, and with waist circumference, systolic blood pressure, diastolic blood pressure, and serum TG in women. And, SIRT1 activity was negatively correlated with aspartate aminotransferase/alanine aminotransferase ratio in women (r = −0.183, p = 0.039). Positive correlation was observed between SIRT1 activity and BMR in women (r = 0.222, p = 0.027), but not in men. Taken together, these findings suggest the possibility that serum SIRT1 activities may be utilized as a biomarker of aging. In addition, positive correlation between SIRT1 activity and BMR in women suggests that serum SIRT1 activity may reflect energy expenditure well in human. PMID:28168178

  11. Basal metabolic rate of endotherms can be modeled using heat-transfer principles and physiological concepts: reply to "can the basal metabolic rate of endotherms be explained by biophysical modeling?".

    Science.gov (United States)

    Roberts, Michael F; Lightfoot, Edwin N; Porter, Warren P

    2011-01-01

    Our recent article (Roberts et al. 2010 ) proposes a mechanistic model for the relation between basal metabolic rate (BMR) and body mass (M) in mammals. The model is based on heat-transfer principles in the form of an equation for distributed heat generation within the body. The model can also be written in the form of the allometric equation BMR = aM(b), in which a is the coefficient of the mass term and b is the allometric exponent. The model generates two interesting results: it predicts that b takes the value 2/3, indicating that BMR is proportional to surface area in endotherms. It also provides an explanation of the physiological components that make up a, that is, respiratory heat loss, core-skin thermal conductance, and core-skin thermal gradient. Some of the ideas in our article have been questioned (Seymour and White 2011 ), and this is our response to those questions. We specifically address the following points: whether a heat-transfer model can explain the level of BMR in mammals, whether our test of the model is inadequate because it uses the same literature data that generated the values of the physiological variables, and whether geometry and empirical values combine to make a "coincidence" that makes the model only appear to conform to real processes.

  12. Variability in basal metabolic rate of a long-distance migrant shorebird (Red Knot, Calidris canutus) reflects shifts in organ sizes

    NARCIS (Netherlands)

    Piersma, T; Bruinzeel, Louis; Drent, R; Kersten, M; VanderMeer, J; Wiersma, P; Meer, Jaap van der

    1996-01-01

    We studied differences in body composition and basal metabolic rate (BMR, measured in postabsorptive birds under thermoneutral conditions at night) in two subspecies of red knots, Calidris canutus: one that spends the nonbreeding season under energetically costly climatic conditions at temperate lat

  13. Taxa metabólica basal em universitários: comparação entre valores medidos e preditos Basal metabolic rate of university students: comparison between measured and predicted values

    Directory of Open Access Journals (Sweden)

    Bruna Camargo Brunetto

    2010-06-01

    calorimetria indireta.OBJECTIVE: The aim of this work is to compare the basal metabolic rate determined by indirect calorimetry with the basal metabolic rate estimated by prediction equations in university students. METHODS: The sample consisted of 48 Brazilian volunteers (23 women and 25 men, aged 20-25 years. The basal metabolic rate determined by indirect calorimetry was compared with the basal metabolic rate estimated by the World Health Organization and Henry & Rees equations. The data was analyzed by the paired t-test, intra-class correlation coefficients, standard deviation of differences and Bland and Altman technique. RESULTS: There were no statistically significant differences between measured and estimated basal metabolic rates by both equations. Correlation coefficients between measured and estimated values were higher in men, however statistically significant in both genders. The magnitude of the standard deviation of differences was similar in both genders. The Bland and Altman technique suggests a similar variability behavior between the measured basal metabolic rate and that estimated by both equations. However, basal metabolic rate predicted by the Henry & Rees equation showed greater concordance than that predicted by the World Health Organization equation, especially in women. CONCLUSION: Due to the use of more conservative statistical indicators, it appears that the basal metabolic rates measured by indirect calorimetry and predicted by both equations do not differ significantly. However, when statistical procedures with an apparently higher sensitivity for detecting differences between measured and predicted rates are used, the potential of the equations to estimate the basal metabolic rate was somewhat compromised. There was a bias of 12.5% to 15.6% in comparison with the basal metabolic rate determined by indirect calorimetry.

  14. Flexibility in basal metabolic rate and evaporative water loss among hoopoe larks exposed to different environmental temperatures.

    Science.gov (United States)

    Williams, J B; Tieleman, B I

    2000-10-01

    The 'energy demand' hypothesis for short-term adjustments in basal metabolic rate (BMR) posits that birds adjust the size of their internal organs relative to food intake, a correlate of energy demand. We tested this hypothesis on hoopoe larks (Alaemon alaudipes), inhabitants of the Arabian desert, by acclimating birds for 3 weeks at 15 degrees C and at 36 degrees C, then measuring their BMR and total evaporative water loss (TEWL). Thereafter, we determined the dry masses of their brain, heart, liver, kidney, stomach, intestine and muscles of the pectoral region. Although mean body mass did not differ initially between the two groups, after 3 weeks, birds in the 15 degrees C group had gained mass (44.1+/-6.5 g), whereas larks in the 36 degrees C group had maintained a constant mass (36.6+/-3.6 g; means +/- s.d., N=6). Birds in the 15 degrees C group had a mean BMR of 46.8+/-6.9 kJ day(-1), whereas birds in the 36 degrees C group had a BMR of 32.9+/-6.3 kJ day(-1), values that were significantly different when we controlled for differences in body mass. When measured at 35 degrees C, larks in the cold-exposure group had a TEWL of 3.55+/-0.60 g H(2)O day(-)(1), whereas TEWL for birds in the 36 degrees C group averaged 2.23+/-0.28 g H(2)O day(-1), a difference of 59.2%. Mass-independent TEWL differed significantly between groups. Larks in the 15 degrees C group had a significantly larger liver, kidney and intestine than larks in the 36 degrees C group. The total increase in organ mass contributed 14.3% towards the total mass increment in the cold exposure group. Increased food intake among larks in the cold group apparently resulted in enlargement of some of the internal organs, and the increase in mass of these organs required a higher rate of oxygen uptake to support them. As oxygen demands increased, larks apparently lost more evaporative water, but the relationship between increases in BMR and TEWL remains unresolved.

  15. Determinação da taxa metabólica basal em cutias, Dasyprocta azarae, por calorimetria indireta Determination of the basal metabolic rate in agoutis, Dasyprocta azarae, by indirect calorimetry

    Directory of Open Access Journals (Sweden)

    Harald F.V. Brito

    2010-06-01

    necessidade de novos estudos sobre o metabolismo de Dasyprocta azarae, sugerindo-se a realização de aferição da taxa metabólica basal e aferição simultânea da concentração sérica de testosterona, estradiol e cortisol para os três grupos.The best way to compare different organisms is the basal metabolic rate, a fundamental interrelation existent among all living beings. Direct measures of oxygen and carbon dioxide concentrations by evaluation of inspired and expired air can be used to measure metabolic rate. So, this research was done in order to measure basal and specific metabolic rates in agoutis (Dasyprocta azarae, and reexamine the scaling of basal metabolism in this species. There were used 34 adult healthy agoutis (9 non-castrated males, 9 castrated males, and 16 females, that belong to the wild animal scientific breeding facility of the Natural History Museum of the Curitiba city, State of Paraná, Brazil. After a six-hour fasting the animals were placed in special boxes under controlled temperature (22.0±1.0ºC, and submitted to measuring of the basal metabolic rate, by indirect calorimetry. It was used the Deltatrac®II metabolic monitor, usually indicated to measure carbon dioxide production (VCO2 and oxygen consumption (VO2 in human beings, by measuring variations in the concentration of VCO2 and of VO2, with a precision of 0.01%. The specific metabolic rate was calculated after determination of the basal metabolic rate and the obtained data were analyzed by inductive statistics. The hypotheses tests for comparison among samples indicated that the specific metabolic rate is higher in non-castrated males than in females and castrated males (significance of 5%, and that the specific metabolic rate of females and castrated males are equivalent (significance of 1%. In addition, analysis of the correlation of experimental points indicates that another variable beyond body size affects the metabolic rate of non-castrated males (significance of 1%, and

  16. [Effect of two hypocaloric diets and their combination with physical exercise on basal metabolic rate and body composition].

    Science.gov (United States)

    Bonfanti, Noelia; Fernández, Juan Marcelo; Gomez-Delgado, Francisco; Pérez-Jiménez, Francisco

    2014-03-01

    El Síndrome Metabólico (SMet) se diagnostica por el cumplimiento de al menos tres criterios: hipertrigliceridemia, HDL-C disminuido, hipertensión arterial, glucemia alterada en ayunas y obesidad. Dicha obesidad constituiría el punto inicial para el desarrollo del SMet. Según la evidencia científica, las dietas hipocalóricas, incluyendo la mediterránea y la reducida en grasa con alto contenido en carbohidratos, reducen la masa grasa (MG) de estos pacientes y su efecto se potencia al combinarse con ejercicio físico (EF), pero se desconoce aún su influencia sobre la tasa metabólica basal (TMB). Objetivo: Conocer el efecto de dos dietas hipocalóricas: mediterránea y baja en grasas, combinadas o no con EF, sobre la TMB y la composición corporal (CC) de adultos con SMet. Métodos: 36 voluntarios, > 50 años, ambos sexos, con diagnóstico de SMet. Se asignaron aleatoriamente a uno de los cuatro grupos de intervención: Dieta hipocalórica mediterránea (MED), Dieta hipocalórica baja en grasa (CHO) ó ambas asociadas a EF (MEDE y CHOE respectivamente). Se evaluó CC (antropometría) y TMB (calorimetría indirecta) antes y después de la intervención. Resultados: La adición de EF a los dos tratamientos hipocalóricos produjo mayor pérdida de peso y MG que las dietas por sí solas, siendo esta pérdida en CHOE > MEDE (p CHOE (p MED (p < 0,05). Conclusiones: CHOE fue el tratamiento que mayor pérdida de peso y MG produjo, induciendo menor reducción de TMB y manteniendo un mejor perfil de CC que MEDE.

  17. Basal metabolism in tropical birds: Latitude, altitude, and the 'pace of life'

    OpenAIRE

    Londoño, GA; Chappell, MA; Castañeda, MDR; Jankowski, JE; Robinson, SK

    2015-01-01

    © 2014 The Authors. Life history varies across latitudes, with the 'pace of life' being 'slower' in tropical regions. Because life history is coupled to energy metabolism via allocation tradeoffs and links between performance capacity and energy use, low metabolic intensity is expected in tropical animals. Low metabolism has been reported for lowland tropical birds, but it is unclear if this is due to 'slow' life history or to a warm, stable environment. We measured basal metabolic rates (BMR...

  18. The effects of diet- and diet plus exercise-induced weight loss on basal metabolic rate and acylated ghrelin in grade 1 obese subjects

    Directory of Open Access Journals (Sweden)

    Lopes AL

    2013-11-01

    Full Text Available André L Lopes,1 Ana Paula T Fayh,2,3 Luisa G de Souza Campos,4 Bruno C Teixeira,1 Randhall B Kreismann Carteri,1 Jerri L Ribeiro,4 Rogério Friedman,2 Álvaro Reischak-Oliveira1 1Exercise Research Laboratory, School of Physical Education, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil; 2Endocrine Unit, Hospital de Clínicas de Porto Alegre, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil; 3Health Sciences College of Trairi, Universidade Federal do Rio Grande do Norte, Santa Cruz, RN, Brazil; 4Centro Universitário Metodista – IPA, Porto Alegre, RS, Brazil Background: Diet and exercise are often prescribed as primary intervention regarding obesity-related disorders. Additionally, recent studies have shown beneficial effects of weight loss through diet and exercise in ghrelin concentrations in obese subjects. The aim of this study was to evaluate the effects of a 5% weight loss on lipid profile, resting metabolic rate (RMR, and acylated ghrelin (AG using two different methods of intervention (diet or diet plus exercise. Materials and methods: Eighteen subjects (twelve women and six men aged 20–40 years with a body mass index of 30–34.9 kg/m2 (grade 1 obesity were randomized into two intervention groups: diet (n=9 or diet plus exercise (n=9. Both groups underwent treatment until 5% of the initial body weight was lost. At baseline and upon completion, RMR and AG were analyzed. Results: Both groups showed a significant decrease in body fat percentage and fat mass. The diet-plus-exercise group showed a decrease in AG (pre: 54.4±25.3 pg/mL and post: 33.2±19.1 pg/mL and an increase in RMR (pre: 1,363±379 kcal/day, post: 1,633±223 kcal/day. Conclusion: These data suggest that diet plus exercise induced weight loss and had beneficial effects on AG concentration and RMR, essential factors to ensure the benefits of a weight-loss program. Keywords: exercise therapy, diet, energy regulation, obesity

  19. Sarcolipin Is a Key Determinant of the Basal Metabolic Rate, and Its Overexpression Enhances Energy Expenditure and Resistance against Diet-induced Obesity.

    Science.gov (United States)

    Maurya, Santosh K; Bal, Naresh C; Sopariwala, Danesh H; Pant, Meghna; Rowland, Leslie A; Shaikh, Sana A; Periasamy, Muthu

    2015-04-24

    Sarcolipin (SLN) is a novel regulator of sarcoplasmic reticulum Ca(2+) ATPase (SERCA) in muscle. SLN binding to SERCA uncouples Ca(2+) transport from ATP hydrolysis. By this mechanism, SLN promotes the futile cycling of SERCA, contributing to muscle heat production. We recently showed that SLN plays an important role in cold- and diet-induced thermogenesis. However, the detailed mechanism of how SLN regulates muscle metabolism remains unclear. In this study, we used both SLN knockout (Sln(-/-)) and skeletal muscle-specific SLN overexpression (Sln(OE)) mice to explore energy metabolism by pair feeding (fixed calories) and high-fat diet feeding (ad libitum). Our results show that, upon pair feeding, Sln(OE) mice lost weight compared with the WT, but Sln(-/-) mice gained weight. Interestingly, when fed with a high-fat diet, Sln(OE) mice consumed more calories but gained less weight and maintained a normal metabolic profile in comparison with WT and Sln(-/-) mice. We found that oxygen consumption and fatty acid oxidation were increased markedly in Sln(OE) mice. There was also an increase in both mitochondrial number and size in Sln(OE) muscle, together with increased expression of peroxisome proliferator-activated receptor δ (PPARδ) and PPAR γ coactivator 1 α (PGC1α), key transcriptional activators of mitochondrial biogenesis and enzymes involved in oxidative metabolism. These results, taken together, establish an important role for SLN in muscle metabolism and energy expenditure. On the basis of these data we propose that SLN is a novel target for enhancing whole-body energy expenditure.

  20. Basal metabolism in tropical birds: latitude, altitude, and the ‘pace of life’

    OpenAIRE

    Londoño, Gustavo Adolfo

    2016-01-01

    Life history varies across latitudes, with the ‘pace of life’ being ‘slower’ in tropical regions. Because life history is coupled to energy metabolism via allocation tradeoffs and links between performance capacity and energy use, low metabolic intensity is expected in tropical animals. Low metabolism has been reported for lowland tropical birds, but it is unclear if this is due to ‘slow’ life history or to a warm, stable environment. We measured basal metabolic rates (BMR) of 253 bird spe...

  1. Calving fluxes and basal melt rates of Antarctic ice shelves.

    Science.gov (United States)

    Depoorter, M A; Bamber, J L; Griggs, J A; Lenaerts, J T M; Ligtenberg, S R M; van den Broeke, M R; Moholdt, G

    2013-10-03

    Iceberg calving has been assumed to be the dominant cause of mass loss for the Antarctic ice sheet, with previous estimates of the calving flux exceeding 2,000 gigatonnes per year. More recently, the importance of melting by the ocean has been demonstrated close to the grounding line and near the calving front. So far, however, no study has reliably quantified the calving flux and the basal mass balance (the balance between accretion and ablation at the ice-shelf base) for the whole of Antarctica. The distribution of fresh water in the Southern Ocean and its partitioning between the liquid and solid phases is therefore poorly constrained. Here we estimate the mass balance components for all ice shelves in Antarctica, using satellite measurements of calving flux and grounding-line flux, modelled ice-shelf snow accumulation rates and a regional scaling that accounts for unsurveyed areas. We obtain a total calving flux of 1,321 ± 144 gigatonnes per year and a total basal mass balance of -1,454 ± 174 gigatonnes per year. This means that about half of the ice-sheet surface mass gain is lost through oceanic erosion before reaching the ice front, and the calving flux is about 34 per cent less than previous estimates derived from iceberg tracking. In addition, the fraction of mass loss due to basal processes varies from about 10 to 90 per cent between ice shelves. We find a significant positive correlation between basal mass loss and surface elevation change for ice shelves experiencing surface lowering and enhanced discharge. We suggest that basal mass loss is a valuable metric for predicting future ice-shelf vulnerability to oceanic forcing.

  2. Redefinition and global estimation of basal ecosystem respiration rate

    DEFF Research Database (Denmark)

    Yuan, Wenping; Luo, Yiqi; Li, Xianglan;

    2011-01-01

    Basal ecosystem respiration rate (BR), the ecosystem respiration rate at a given temperature, is a common and important parameter in empirical models for quantifying ecosystem respiration (ER) globally. Numerous studies have indicated that BR varies in space. However, many empirical ER models still...... use a global constant BR largely due to the lack of a functional description for BR. In this study, we redefined BR to be ecosystem respiration rate at the mean annual temperature. To test the validity of this concept, we conducted a synthesis analysis using 276 site-years of eddy covariance data...... use efficiency GPP model (i.e., EC-LUE) was applied to estimate global GPP, BR and ER with input data from MERRA (Modern Era Retrospective-Analysis for Research and Applications) and MODIS (Moderate resolution Imaging Spectroradiometer). The global ER was 103 Pg C yr −1, with the highest respiration...

  3. Rates of glucose utilization and glucogenesis in rats in the basal state induced by halothane anaesthesia.

    Science.gov (United States)

    Heath, D F; Frayn, K N; Rose, J G

    1977-03-15

    1. Rates and rate coefficients of glucose utilization and replacement were determined with [5-3H]- and [U-14C]-glucose in rats starved for 24h, either conscious or under halothane anaesthesia, in a thermoneutral environment. Plasma insulin concentrations were also measured. 2. Halothane anaesthesia decreased the turnover rate by 20%, which was similar to previously reported decreases in metabolic rates caused by natural sleep. 3. Fractional recycling of glucose carbon was little affected by halothane. 4. Comparison of values in one rat with those in another, among both conscious rats and those under halothane anaesthesia, showed that rate coefficients were inversely correlated with plasma glucose concentrations. 5. These findings indicated that halothane, in the concentration used (1.25%, v/v), had little specific effect on glucose metabolism. 6. Although equilibrium plasma glucose concentrations in different rats under halothane were widely different (4-8 mmol/l) the rates of utilization were very similar (2.5-3.1 micronmol/min per 100 g), indicating that these rates were determined by the production of glucose from gluconeogenic precursors released by basal metabolism, the rate of which is necessarily similar in different rats. 7. Among rats under halothane anaesthesia plasma insulin concentrations were negatively correlated with rate coefficients, showing that the differences between rate coefficients were mostly accounted for by differences between rats in tissue sensitivities to insulin. Thus in each 24h-starved rat, sleeping or resting, the main regulators of the plasma glucose concentrations were the rate of supply of gluconeogenic substrates from energy metabolism and the intrinsic sensitivity of the tissues to insulin. 8. We found that a commonly used deionization method of purifying glucose for determination of its specific radioactivity was inadequate.

  4. Basal metabolism is correlated with habitat productivity among populations of degus (Octodon degus).

    Science.gov (United States)

    Bozinovic, Francisco; Rojas, José M; Broitman, Bernardo R; Vásquez, Rodrigo A

    2009-04-01

    Several competing hypotheses attempt to explain how environmental conditions affect mass-independent basal metabolic rate (BMR) in mammals. One of the most inclusive is the hypothesis that associates BMR with food habits, including habitat productivity. The effects of food habits have been widely investigated at the interspecific level, and variation between individuals and populations has been largely ignored. Intraspecific analysis of physiological traits has the potential to compensate for many pitfalls associated with interspecific analyses and serve as a useful approach for evaluating hypotheses regarding metabolic adaptation. Here we tested the effects of climatic variables (mean annual rainfall=PP, mean annual temperature=T(A)), net primary productivity (NPP) and the de Martonne index (DMi) of aridity on mass-independent BMR among four populations of the caviomorph rodent Octodon degus along a geographic gradient in Chile. BMR was measured on animals maintained in a common garden acclimation set-up, thus kept under the same environment and diet quality for at least 6 months. Mass-independent BMR was significantly different among degu populations showing a large intraspecific spread in metabolic rates. A very large fraction of interpopulational variability in mass-independent BMR was explained by NPP, PP and DMi. Our results were conclusive about the effects of habitat productivity on setting the level of mass-independent BMR at the intraspecific-interpopulational level.

  5. Heart rate responses induced by acoustic tempo and its interaction with basal heart rate

    Science.gov (United States)

    Watanabe, Ken; Ooishi, Yuuki; Kashino, Makio

    2017-01-01

    Many studies have revealed the influences of music on the autonomic nervous system (ANS). Since previous studies focused on the effects of acoustic tempo on the ANS, and humans have their own physiological oscillations such as the heart rate (HR), the effects of acoustic tempo might depend on the HR. Here we show the relationship between HR elevation induced by acoustic tempo and individual basal HR. Since high tempo-induced HR elevation requires fast respiration, which is based on sympatho-respiratory coupling, we controlled the participants’ respiration at a faster rate (20 CPM) than usual (15 CPM). We found that sound stimuli with a faster tempo than the individual basal HR increased the HR. However, the HR increased following a gradual increase in the acoustic tempo only when the extent of the gradual increase in tempo was within a specific range (around + 2%/min). The HR did not follow the increase in acoustic tempo when the rate of the increase in the acoustic tempo exceeded 3% per minute. These results suggest that the effect of the sympatho-respiratory coupling underlying the HR elevation caused by a high acoustic tempo depends on the basal HR, and the strength and the temporal dynamics of the tempo. PMID:28266647

  6. Personality, metabolic rate and aerobic capacity.

    Directory of Open Access Journals (Sweden)

    Antonio Terracciano

    Full Text Available Personality traits and cardiorespiratory fitness in older adults are reliable predictors of health and longevity. We examined the association between personality traits and energy expenditure at rest (basal metabolic rate and during normal and maximal sustained walking. Personality traits and oxygen (VO(2 consumption were assessed in 642 participants from the Baltimore Longitudinal Study of Aging. Results indicate that personality traits were mostly unrelated to resting metabolic rate and energy expenditure at normal walking pace. However, those who scored lower on neuroticism (r = -0.12 and higher on extraversion (r = 0.11, openness (r = 0.13, and conscientiousness (r = 0.09 had significantly higher energy expenditure at peak walking pace. In addition to greater aerobic capacity, individuals with a more resilient personality profile walked faster and were more efficient in that they required less energy per meter walked. The associations between personality and energy expenditure were not moderated by age or sex, but were in part explained by the proportion of fat mass. In conclusion, differences in personality may matter the most during more challenging activities that require cardiorespiratory fitness. These findings suggest potential pathways that link personality to health outcomes, such as obesity and longevity.

  7. Proximal tubule-specific glutamine synthetase deletion alters basal and acidosis-stimulated ammonia metabolism.

    Science.gov (United States)

    Lee, Hyun-Wook; Osis, Gunars; Handlogten, Mary E; Lamers, Wouter H; Chaudhry, Farrukh A; Verlander, Jill W; Weiner, I David

    2016-06-01

    Glutamine synthetase (GS) catalyzes the recycling of NH4 (+) with glutamate to form glutamine. GS is highly expressed in the renal proximal tubule (PT), suggesting ammonia recycling via GS could decrease net ammoniagenesis and thereby limit ammonia available for net acid excretion. The purpose of the present study was to determine the role of PT GS in ammonia metabolism under basal conditions and during metabolic acidosis. We generated mice with PT-specific GS deletion (PT-GS-KO) using Cre-loxP techniques. Under basal conditions, PT-GS-KO increased urinary ammonia excretion significantly. Increased ammonia excretion occurred despite decreased expression of key proteins involved in renal ammonia generation. After the induction of metabolic acidosis, the ability to increase ammonia excretion was impaired significantly by PT-GS-KO. The blunted increase in ammonia excretion occurred despite greater expression of multiple components of ammonia generation, including SN1 (Slc38a3), phosphate-dependent glutaminase, phosphoenolpyruvate carboxykinase, and Na(+)-coupled electrogenic bicarbonate cotransporter. We conclude that 1) GS-mediated ammonia recycling in the PT contributes to both basal and acidosis-stimulated ammonia metabolism and 2) adaptive changes in other proteins involved in ammonia metabolism occur in response to PT-GS-KO and cause an underestimation of the role of PT GS expression.

  8. The Effect of Jiakangning on Basal Metabolic Rate and Thyroid Function in Patients of Hyperthyroidism Combined With Liver Loss%甲亢宁对甲亢合并肝损患者甲状腺功能及基础代谢率的影响

    Institute of Scientific and Technical Information of China (English)

    周莉娟

    2015-01-01

    Objective To investigate the effects of hyperthyroidism jiakangning on liver and thyroid function in patients with basal metabolic rate loss. Methods 80 cases of liver damage in patients with hyperthyroidism were randomly divided into control and treatment groups with 40 patients in the control group was ifne gamping basis of conventional methods combined treatment group hyperthyroidism combined basis rather conventional therapy, were observed three FT3, FT4 and TSH and basal metabolic rate (BMR) changes in the months after. Results The total efficiency of the treatment group cure rate and the treatment of 45.0%(18/40), 95.0% (38/40) were significantly higher than 25.0% (10/40), 75.0% (30/40) (P<0.05). Conclusion The treatment of hyperthyroidism jiakangning liver damage was signiifcantly better.%目的:探讨甲亢宁对甲亢合并肝损患者甲状腺功能及基础代谢率的影响。方法将80例甲亢合并肝损患者随机分为对照组和治疗组各40例,对照组天晴甘平结合基础常规方法治疗,治疗组甲亢宁结合基础常规方法治疗,观察两组患者三个月后的FT3、FT4以及TSH和基础代谢率(BMR)的变化情况。结果治疗组的治愈率和治疗的总有效率45.0%(18/40)、95.0%(38/40)均高于对照组25.0%(10/40)、75.0%(30/40()P<0.05)。结论利用甲亢宁治疗甲亢合并肝损效果更佳。

  9. Validation of Algorithms for Basal Insulin Rate Reductions in Type 1 Diabetic Patients Practising Physical Activity

    Science.gov (United States)

    2013-04-19

    Type 1 Diabetes With a Subcutaneous Insulin Pump; Adjustment of the Recommended Basal Insulin Flow Rate in the Event of Physical Activity; Adjustment of the Recommended Prandial Insulin in the Event of Physical Activity

  10. A phylogenetic analysis of basal metabolism, total evaporative water loss, and life-history among foxes from desert and mesic regions

    NARCIS (Netherlands)

    Williams, JB; Munoz-Garcia, A; Ostrowski, S; Tieleman, BI

    2004-01-01

    We measured basal metabolic rate (BMR) and total evaporative water loss (TEWL) of species of foxes that exist on the Arabian Peninsula, Blanford's fox (Vulpes cana) and two subspecies of Red fox (Vulpes vulpes). Combining these data with that on other canids from the literature, we searched for spec

  11. Endotoxin-induced basal respiration alterations of renal HK-2 cells: A sign of pathologic metabolism down-regulation

    Energy Technology Data Exchange (ETDEWEB)

    Quoilin, C., E-mail: cquoilin@ulg.ac.be [Laboratory of Biomedical Spectroscopy, Department of Physics, University of Liege, 4000 Liege (Belgium); Mouithys-Mickalad, A. [Center of Oxygen Research and Development, Department of Chemistry, University of Liege, 4000 Liege (Belgium); Duranteau, J. [Department of Anaesthesia and Surgical ICU, CHU Bicetre, University Paris XI Sud, 94275 Le Kremlin Bicetre (France); Gallez, B. [Biomedical Magnetic Resonance Group, Louvain Drug Research Institute, Universite catholique de Louvain, 1200 Brussels (Belgium); Hoebeke, M. [Laboratory of Biomedical Spectroscopy, Department of Physics, University of Liege, 4000 Liege (Belgium)

    2012-06-29

    Highlights: Black-Right-Pointing-Pointer A HK-2 cells model of inflammation-induced acute kidney injury. Black-Right-Pointing-Pointer Two oximetry methods: high resolution respirometry and ESR spectroscopy. Black-Right-Pointing-Pointer Oxygen consumption rates of renal cells decrease when treated with LPS. Black-Right-Pointing-Pointer Cells do not recover normal respiration when the LPS treatment is removed. Black-Right-Pointing-Pointer This basal respiration alteration is a sign of pathologic metabolism down-regulation. -- Abstract: To study the mechanism of oxygen regulation in inflammation-induced acute kidney injury, we investigate the effects of a bacterial endotoxin (lipopolysaccharide, LPS) on the basal respiration of proximal tubular epithelial cells (HK-2) both by high-resolution respirometry and electron spin resonance spectroscopy. These two complementary methods have shown that HK-2 cells exhibit a decreased oxygen consumption rate when treated with LPS. Surprisingly, this cellular respiration alteration persists even after the stress factor was removed. We suggested that this irreversible decrease in renal oxygen consumption after LPS challenge is related to a pathologic metabolic down-regulation such as a lack of oxygen utilization by cells.

  12. Mevalonate metabolism regulates Basal breast cancer stem cells and is a potential therapeutic target.

    Science.gov (United States)

    Ginestier, Christophe; Monville, Florence; Wicinski, Julien; Cabaud, Olivier; Cervera, Nathalie; Josselin, Emmanuelle; Finetti, Pascal; Guille, Arnaud; Larderet, Gaelle; Viens, Patrice; Sebti, Said; Bertucci, François; Birnbaum, Daniel; Charafe-Jauffret, Emmanuelle

    2012-07-01

    There is increasing evidence that breast tumors are organized in a hierarchy, with a subpopulation of tumorigenic cancer cells, the cancer stem cells (CSCs), which sustain tumor growth. The characterization of protein networks that govern CSC behavior is paramount to design new therapeutic strategies targeting this subpopulation of cells. We have sought to identify specific molecular pathways of CSCs isolated from 13 different breast cancer cell lines of luminal or basal/mesenchymal subtypes. We compared the gene expression profiling of cancer cells grown in adherent conditions to those of matched tumorsphere cultures. No specific pathway was identified to be commonly regulated in luminal tumorspheres, resulting from a minor CSC enrichment in tumorsphere passages from luminal cell lines. However, in basal/mesenchymal tumorspheres, the enzymes of the mevalonate metabolic pathway were overexpressed compared to those in cognate adherent cells. Inhibition of this pathway with hydroxy-3-methylglutaryl CoA reductase blockers resulted in a reduction of breast CSC independent of inhibition of cholesterol biosynthesis and of protein farnesylation. Further modulation of this metabolic pathway demonstrated that protein geranylgeranylation (GG) is critical to breast CSC maintenance. A small molecule inhibitor of the geranylgeranyl transferase I (GGTI) enzyme reduced the breast CSC subpopulation both in vitro and in primary breast cancer xenografts. We found that the GGTI effect on the CSC subpopulation is mediated by inactivation of Ras homolog family member A (RHOA) and increased accumulation of P27(kip1) in the nucleus. The identification of protein GG as a major contributor to CSC maintenance opens promising perspectives for CSC targeted therapy in basal breast cancer.

  13. Stress during puberty boosts metabolic activation associated with fear-extinction learning in hippocampus, basal amygdala and cingulate cortex.

    Science.gov (United States)

    Toledo-Rodriguez, Maria; Pitiot, Alain; Paus, Tomáš; Sandi, Carmen

    2012-07-01

    Adolescence is characterized by major developmental changes that may render the individual vulnerable to stress and the development of psychopathologies in a sex-specific manner. Earlier we reported lower anxiety-like behavior and higher risk-taking and novelty seeking in rats previously exposed to peri-pubertal stress. Here we studied whether peri-pubertal stress affected the acquisition and extinction of fear memories and/or the associated functional engagement of various brain regions, as assessed with 2-deoxyglucose. We showed that while peri-pubertal stress reduced freezing during the acquisition of fear memories (training) in both sexes, it had a sex-specific effect on extinction of these memories. Moreover hippocampus, basal amygdala and cingulate and motor cortices showed higher metabolic rates during extinction in rats exposed to peri-pubertal stress. Interestingly, activation of the infralimbic cortex was negatively correlated with freezing during extinction only in control males, while only males stressed during puberty showed a significant correlation between behavior during extinction and metabolic activation of hippocampus, amygdala and paraventricular nucleus. No correlations between brain activation and behavior during extinction were observed in females (control or stress). These results indicate that exposure to peri-pubertal stress affects behavior and brain metabolism when the individual is exposed to an additional stressful challenge. Some of these effects are sex-specific.

  14. THE RELATIONSHIP AMONG METABOLIC RATE OF TREE SHREWS (TUPAIA BELANGERI) UNDER COLD ACCLIMATION

    OpenAIRE

    Lin Zhang; Wenrong Gao; Wenxiu Jiang; Zhengkun Wang

    2012-01-01

    Many small mammals inhabiting cold environments display enhanced capacity for seasonal changes in nonshivering thermogenesis (NST) and thermoregulatory maximum metabolic rate (MMR). However, it is not known how this plasticity remains in a mammal that rarely experiences extreme cold fluctuations. In order to answer this question, we determined body mass ( Mb), basal metabolic rate (BMR), NST, and MMR on a tree shrews (Tupaia belangeri), acclimated to cold (5 ºC) conditions. NST was measured a...

  15. Recurrence rate of basal cell carcinoma with positive histopathological margins and related risk factors*

    Science.gov (United States)

    Lara, Fernanda; Santamaría, Jesus Rodriguez; Garbers, Luiz Eduardo Fabricio de Melo

    2017-01-01

    BACKGROUND The best way to approach surgically removed basal cell carcinoma with positive histopathological margins is a controversial issue. Some authors believe that the more appropriate treatment is an immediate reoperation while others prefer a periodic follow up. The rates of recurrence are variable in literature, between 10% and 67%. OBJECTIVE To define the recurrence rate of basal cell carcinoma with positive margins after surgery. Secondarily, identify morphological aspects that can suggest a more frequent tumoral recurrence. METHODS This was a retrospective and observational study made by analysis of medical records of 487 patients between January 2003 and December 2009 in Hospital de Clínicas da Universidade Federal do Paraná (HC-UFPR). From 402 basal cell carcinomas surgically treated, 41 fulfilled inclusion criteria and were evaluated for five years or more. Recurrence rate of these tumors was analyzed in all patients and clinical characteristics such as sex, age, tumor size, tumor site, ulceration, and histological type were evaluated in order to find if they were related to more common tumoral recurrence. RESULTS The rate of positive margins after surgery was 12.18%. There were five cases of tumoral recurrence in the observation group and three cases in the re-excision group. Tumor size, site, histological type, ulceration and type of positive margin did not differ statistically between groups. It was not possible to consider if these factors were important in recurrence rates. STUDY LIMITATIONS Ideally, a prospective study with a larger sample would be more accurate. CONCLUSION The treatment of choice in basal cell carcinoma with positive margins must be individualized to reduce recurrence rates. PMID:28225958

  16. Thyroid hormones correlate with resting metabolic rate, not daily energy expenditure, in two charadriiform seabirds

    Directory of Open Access Journals (Sweden)

    Kyle H. Elliott

    2013-04-01

    Thyroid hormones affect in vitro metabolic intensity, increase basal metabolic rate (BMR in the lab, and are sometimes correlated with basal and/or resting metabolic rate (RMR in a field environment. Given the difficulty of measuring metabolic rate in the field—and the likelihood that capture and long-term restraint necessary to measure metabolic rate in the field jeopardizes other measurements—we examined the possibility that circulating thyroid hormone levels were correlated with RMR in two free-ranging bird species with high levels of energy expenditure (the black-legged kittiwake, Rissa tridactyla, and thick-billed murre, Uria lomvia. Because BMR and daily energy expenditure (DEE are purported to be linked, we also tested for a correlation between thyroid hormones and DEE. We examined the relationships between free and bound levels of the thyroid hormones thyroxine (T4 and triiodothyronine (T3 with DEE and with 4-hour long measurements of post-absorptive and thermoneutral resting metabolism (resting metabolic rate; RMR. RMR but not DEE increased with T3 in both species; both metabolic rates were independent of T4. T3 and T4 were not correlated with one another. DEE correlated with body mass in kittiwakes but not in murres, presumably owing to the larger coefficient of variation in body mass during chick rearing for the more sexually dimorphic kittiwakes. We suggest T3 provides a good proxy for resting metabolism but not DEE in these seabird species.

  17. Interplay between metabolic rate and diet quality in the South American fox, Pseudalopex culpaeus.

    Science.gov (United States)

    Silva, Sergio I; Jaksic, Fabian M; Bozinovic, Francisco

    2004-01-01

    We studied the metabolic costs associated with the ingestion of peppertree fruits (Schinus molle) in the culpeo fox, Pseudalopex culpaeus, the second largest canid in South America. Throughout its range of distribution, this fox feeds on rodents and other small vertebrates, and also on peppertree fruits, which represent 98% of total fruits consumed in semiarid Chile. Peppertree contains a high diversity of phytochemicals. Foxes feeding on diets containing rats and peppertree fruits (mixed diets) exhibited a 98.9% increase in basal rate of metabolism when compared to rat-acclimated foxes. Thus, acute ingestion of chemically defended fruits has an energetic cost for the fox, reflected in higher values of basal metabolism. Increased metabolic rates may be associated with increased protein synthesis for detoxification and for tissue repair, including the production of biotransformation enzymes.

  18. Validity and reproducibility of resting metabolic rate measurements in rural Bangladeshi women: comparison of measurements obtained by Medgem and by Deltatrac device

    NARCIS (Netherlands)

    Alam, D.S.; Hulshof, P.J.M.; Roordink, D.; Meltzer, M.; Yunus, M.; Salam, M.A.; Raaij, van J.M.A.

    2005-01-01

    Objective:To assess reproducibility and validity of resting metabolic rate (RMR) of Bangladeshi women as measured with the MedGem device and using the Deltatrac metabolic monitor as a reference; and (2) to evaluate the FAO/WHO/UNU basal metabolic rate (BMR)-prediction equations. Design:In each of tw

  19. Program for PET image alignment: Effects on calculated differences in cerebral metabolic rates for glucose

    Energy Technology Data Exchange (ETDEWEB)

    Phillips, R.L.; London, E.D.; Links, J.M.; Cascella, N.G. (NIDA Addiction Research Center, Baltimore, MD (USA))

    1990-12-01

    A program was developed to align positron emission tomography images from multiple studies on the same subject. The program allowed alignment of two images with a fineness of one-tenth the width of a pixel. The indications and effects of misalignment were assessed in eight subjects from a placebo-controlled double-blind crossover study on the effects of cocaine on regional cerebral metabolic rates for glucose. Visual examination of a difference image provided a sensitive and accurate tool for assessing image alignment. Image alignment within 2.8 mm was essential to reduce variability of measured cerebral metabolic rates for glucose. Misalignment by this amount introduced errors on the order of 20% in the computed metabolic rate for glucose. These errors propagate to the difference between metabolic rates for a subject measured in basal versus perturbed states.

  20. Cellular metabolic rate is influenced by life-history traits in tropical and temperate birds.

    Science.gov (United States)

    Jimenez, Ana Gabriela; Van Brocklyn, James; Wortman, Matthew; Williams, Joseph B

    2014-01-01

    In general, tropical birds have a "slow pace of life," lower rates of whole-animal metabolism and higher survival rates, than temperate species. A fundamental challenge facing physiological ecologists is the understanding of how variation in life-history at the whole-organism level might be linked to cellular function. Because tropical birds have lower rates of whole-animal metabolism, we hypothesized that cells from tropical species would also have lower rates of cellular metabolism than cells from temperate species of similar body size and common phylogenetic history. We cultured primary dermal fibroblasts from 17 tropical and 17 temperate phylogenetically-paired species of birds in a common nutritive and thermal environment and then examined basal, uncoupled, and non-mitochondrial cellular O2 consumption (OCR), proton leak, and anaerobic glycolysis (extracellular acidification rates [ECAR]), using an XF24 Seahorse Analyzer. We found that multiple measures of metabolism in cells from tropical birds were significantly lower than their temperate counterparts. Basal and uncoupled cellular metabolism were 29% and 35% lower in cells from tropical birds, respectively, a decrease closely aligned with differences in whole-animal metabolism between tropical and temperate birds. Proton leak was significantly lower in cells from tropical birds compared with cells from temperate birds. Our results offer compelling evidence that whole-animal metabolism is linked to cellular respiration as a function of an animal's life-history evolution. These findings are consistent with the idea that natural selection has uniquely fashioned cells of long-lived tropical bird species to have lower rates of metabolism than cells from shorter-lived temperate species.

  1. Cellular metabolic rate is influenced by life-history traits in tropical and temperate birds.

    Directory of Open Access Journals (Sweden)

    Ana Gabriela Jimenez

    Full Text Available In general, tropical birds have a "slow pace of life," lower rates of whole-animal metabolism and higher survival rates, than temperate species. A fundamental challenge facing physiological ecologists is the understanding of how variation in life-history at the whole-organism level might be linked to cellular function. Because tropical birds have lower rates of whole-animal metabolism, we hypothesized that cells from tropical species would also have lower rates of cellular metabolism than cells from temperate species of similar body size and common phylogenetic history. We cultured primary dermal fibroblasts from 17 tropical and 17 temperate phylogenetically-paired species of birds in a common nutritive and thermal environment and then examined basal, uncoupled, and non-mitochondrial cellular O2 consumption (OCR, proton leak, and anaerobic glycolysis (extracellular acidification rates [ECAR], using an XF24 Seahorse Analyzer. We found that multiple measures of metabolism in cells from tropical birds were significantly lower than their temperate counterparts. Basal and uncoupled cellular metabolism were 29% and 35% lower in cells from tropical birds, respectively, a decrease closely aligned with differences in whole-animal metabolism between tropical and temperate birds. Proton leak was significantly lower in cells from tropical birds compared with cells from temperate birds. Our results offer compelling evidence that whole-animal metabolism is linked to cellular respiration as a function of an animal's life-history evolution. These findings are consistent with the idea that natural selection has uniquely fashioned cells of long-lived tropical bird species to have lower rates of metabolism than cells from shorter-lived temperate species.

  2. The relationship between body mass and field metabolic rate among individual birds and mammals.

    Science.gov (United States)

    Hudson, Lawrence N; Isaac, Nick J B; Reuman, Daniel C

    2013-09-01

    1. The power-law dependence of metabolic rate on body mass has major implications at every level of ecological organization. However, the overwhelming majority of studies examining this relationship have used basal or resting metabolic rates, and/or have used data consisting of species-averaged masses and metabolic rates. Field metabolic rates are more ecologically relevant and are probably more directly subject to natural selection than basal rates. Individual rates might be more important than species-average rates in determining the outcome of ecological interactions, and hence selection. 2. We here provide the first comprehensive database of published field metabolic rates and body masses of individual birds and mammals, containing measurements of 1498 animals of 133 species in 28 orders. We used linear mixed-effects models to answer questions about the body mass scaling of metabolic rate and its taxonomic universality/heterogeneity that have become classic areas of controversy. Our statistical approach allows mean scaling exponents and taxonomic heterogeneity in scaling to be analysed in a unified way while simultaneously accounting for nonindependence in the data due to shared evolutionary history of related species. 3. The mean power-law scaling exponents of metabolic rate vs. body mass relationships were 0.71 [95% confidence intervals (CI) 0.625-0.795] for birds and 0.64 (95% CI 0.564-0.716) for mammals. However, these central tendencies obscured meaningful taxonomic heterogeneity in scaling exponents. The primary taxonomic level at which heterogeneity occurred was the order level. Substantial heterogeneity also occurred at the species level, a fact that cannot be revealed by species-averaged data sets used in prior work. Variability in scaling exponents at both order and species levels was comparable to or exceeded the differences 3/4-2/3 = 1/12 and 0.71-0.64. 4. Results are interpreted in the light of a variety of existing theories. In particular, results

  3. Long-term effect of yogic practices on diurnal metabolic rates of healthy subjects

    Directory of Open Access Journals (Sweden)

    Chaya M

    2008-01-01

    Full Text Available Background: The metabolic rate is an indicator of autonomic activity. Reduced sympathetic arousal probably resulting in hypometabolic states has been reported in several yogic studies. Aim: The main objective of this study was to assess the effect of yoga training on diurnal metabolic rates in yoga practitioners at two different times of the day (at 6 a.m. and 9 p.m.. Methods and Material: Eighty eight healthy volunteers were selected and their metabolic rates assessed at 6 a.m. and 9 p.m. using an indirect calorimeter at a yoga school in Bangalore, India. Results and conclusions: The results show that the average metabolic rate of the yoga group was 12% lower than that of the non-yoga group ( P < 0.001 measured at 9 p.m. and 16% lower at 6 a.m. ( P < 0.001. The 9 p.m. metabolic rates of the yoga group were almost equal to their predicted basal metabolic rates (BMRs whereas the metabolic rate was significantly higher than the predicted BMR for the non-yoga group. The 6 a.m. metabolic rate was comparable to their predicted BMR in the non-yoga group whereas it was much lower in the yoga group ( P < 0.001. The lower metabolic rates in the yoga group at 6 a.m. and 9 p.m. may be due to coping strategies for day-to-day stress, decreased sympathetic nervous system activity and probably, a stable autonomic nervous system response (to different stressors achieved due to training in yoga.

  4. Habituation to low or high protein intake does not modulate basal or postprandial muscle protein synthesis rates: a randomized trial

    NARCIS (Netherlands)

    Gorissen, S.H.; Horstman, Astrid; Franssen, Rinske; Kouw, I.W.; Wall, B.T.; Burd, N.A.; Groot, de C.P.G.M.; Loon, van L.J.C.

    2017-01-01

    Background: Muscle mass maintenance is largely regulated by basal muscle protein synthesis rates and the ability to increase muscle protein synthesis after protein ingestion. To our knowledge, no previous studies have evaluated the impact of habituation to either low protein intake (LOW PRO) or high

  5. Flight Modes in Migrating European Bee-Eaters: Heart Rate May Indicate Low Metabolic Rate during Soaring and Gliding

    Science.gov (United States)

    Sapir, Nir; Wikelski, Martin; McCue, Marshall D.; Pinshow, Berry; Nathan, Ran

    2010-01-01

    Background Many avian species soar and glide over land. Evidence from large birds (mb>0.9 kg) suggests that soaring-gliding is considerably cheaper in terms of energy than flapping flight, and costs about two to three times the basal metabolic rate (BMR). Yet, soaring-gliding is considered unfavorable for small birds because migration speed in small birds during soaring-gliding is believed to be lower than that of flapping flight. Nevertheless, several small bird species routinely soar and glide. Methodology/Principal Findings To estimate the energetic cost of soaring-gliding flight in small birds, we measured heart beat frequencies of free-ranging migrating European bee-eaters (Merops apiaster, mb∼55 g) using radio telemetry, and established the relationship between heart beat frequency and metabolic rate (by indirect calorimetry) in the laboratory. Heart beat frequency during sustained soaring-gliding was 2.2 to 2.5 times lower than during flapping flight, but similar to, and not significantly different from, that measured in resting birds. We estimated that soaring-gliding metabolic rate of European bee-eaters is about twice their basal metabolic rate (BMR), which is similar to the value estimated in the black-browed albatross Thalassarche (previously Diomedea) melanophrys, mb∼4 kg). We found that soaring-gliding migration speed is not significantly different from flapping migration speed. Conclusions/Significance We found no evidence that soaring-gliding speed is slower than flapping flight in bee-eaters, contradicting earlier estimates that implied a migration speed penalty for using soaring-gliding rather than flapping flight. Moreover, we suggest that small birds soar and glide during migration, breeding, dispersal, and other stages in their annual cycle because it may entail a low energy cost of transport. We propose that the energy cost of soaring-gliding may be proportional to BMR regardless of bird size, as theoretically deduced by earlier studies

  6. Anterior olfactory organ removal produces anxiety-like behavior and increases spontaneous neuronal firing rate in basal amygdala.

    Science.gov (United States)

    Contreras, Carlos M; Gutiérrez-García, Ana G; Molina-Jiménez, Tania

    2013-09-01

    Some chemical cues may produce signs of anxiety and fear mediated by amygdala nuclei, but unknown is the role of two anterior olfactory epithelial organs, the septal and vomeronasal organs (SO-VNOs). The effects of SO-VNO removal were explored in different groups of Wistar rats using two complementary approaches: (i) the assessment of neuronal firing rate in basal and medial amygdala nuclei and (ii) behavioral testing. Fourteen days after SO-VNO removal, spontaneous activity in basal and medial amygdala nuclei in one group was determined using single-unit extracellular recordings. A separate group of rats was tested in the elevated plus maze, social interaction test, and open field test. Compared with sham-operated and intact control rats, SO-VNO removal produced a higher neuronal firing rate in the basal amygdala but not medial amygdala. In the behavioral tests, SO-VNO removal increased signs of anxiety in the elevated plus maze, did not alter locomotion, and increased self-directed behavior, reflecting anxiety-like behavior. Histological analysis showed neuronal destruction in the accessory olfactory bulb but not anterior olfactory nucleus in the SO-VNO group. The present results suggest the participation of SO-VNO/accessory olfactory bulb/basal amygdala relationships in the regulation of anxiety through a process of disinhibition.

  7. Seasonal variation in basal emission rates and composition of mono- and sesquiterpenes emitted from dominant conifers in Japan

    Science.gov (United States)

    Matsunaga, Sou N.; Niwa, Shigeru; Mochizuki, Tomoki; Tani, Akira; Kusumoto, Dai; Utsumi, Yasuhiro; Enoki, Tsutomu; Hiura, Tsutom

    2013-04-01

    Biogenic volatile organic compounds (BVOCs) are known to play an important role in atmospheric chemistry due to their high reactivity and high emission rates. Therefore, in recent decades, many efforts have been made to estimate the emission rates, composition and allocation of the BVOCs. Monoterpenes (MNTs) and sesquiterpenes (SQTs) are major groups of BVOCs and mainly emitted from coniferous trees. There is quite a few reports discussing the seasonality of basal emission rate, which is a normalized emission rate at a set of standard conditions (e.g. temperature, light intensity), of the BVOCs. Three field measurements were conducted using branch enclosure techniques to determine MNTs and SQTs emission measured from mature trees of Cryptomeria japonica and Chamaecyparis obtusa, which are the most dominant trees in Japan and account for about 40-50% of Japanese forest in leaf amount throughout the four seasons in southern Japan in 2010. The results are compared with the measurements for the same compound classes obtained at a suburban area of Tokyo, Japan in 2009. The seasonal variation in the basal emissions of MNTs from both tree species at Shiiba did not show significant seasonal changes. For both tree species, the variations in the basal emission of MNTs differ in the two sites, while those of SQTs showed relatively similar variations. Chemical composition of SQTs showed clear and continued seasonal variations, while MNTs did not show any clear seasonal variation for these tree species at both sites. It can be hypothesized that the emissions of BVOC classes (e.g. MNTs and SQTs) depend on leaf age. In this paper, we discuss about the seasonal variations in the basal emission rates and chemical compositions of BVOCs obtained from the two dominant coniferous tree species in Japan based on nine field measurement campaigns conducted at two different sites.

  8. The relationship among metabolic rate of tree shrews (Tupaia belangeri under cold acclimation

    Directory of Open Access Journals (Sweden)

    Lin Zhang

    2012-11-01

    Full Text Available Many small mammals inhabiting cold environments display enhanced capacity for seasonal changes in nonshivering thermogenesis (NST and thermoregulatory maximum metabolic rate (MMR. However, it is not known how this plasticity remains in a mammal that rarely experiences extreme cold fluctuations. In order to answer this question, we determined body mass ( Mb, basal metabolic rate (BMR, NST, and MMR on a tree shrews (Tupaia belangeri, acclimated to cold (5 ºC conditions. NST was measured as the maximum response of metabolic rate (NSTmax after injection of norepinephrine (NE in thermoneutrality minus BMR. Maximum metabolic rate was assessed in animals exposed to enhanced heat-loss atmosphere (He-O2 connected with an open-flow respirometer. Body mass and metabolic variables increased significantly after cold acclimation with respect to control group but to a high extent (BMR, 87.97%; NST, 69.77%; and MMR, 32.35%. However, aerobic scope (MMR/BMR, and calculated shivering thermogenesis (ST did not significantly change with control group. Our data suggest: 1. The body mass and the capacity of heat production in the cold acclimated group were higher; 2. The increase of BMR and MMR during cold acclimation was the main pattern of heat production in the tree shrews.

  9. Expensive brains: ‘brainy’ rodents have higher metabolic rate

    Directory of Open Access Journals (Sweden)

    Raúl eSobrero

    2011-07-01

    Full Text Available Brains are the centers of the nervous system of animals, controlling the organ systems of the body and coordinating responses to changes in the ecological and social environment. The evolution traits that correlate with cognitive ability, such as relative brain size is thus of broad interest. Brain mass relative to body mass varies among mammals, and diverse factors have been proposed to explain this variation. A recent study provided evidence that energetics play an important role in brain evolution (Isler and van Schaik, 2006. Using composite phylogenies and data drawn from multiple sources, these authors showed that basal metabolic rate (BMR correlates with brain mass across mammals. However, no such relationship was found within rodents. Here we re-examined the relationship between BMR and brain mass within Rodentia using a novel species-level phylogeny. Our results are sensitive to parameter evaluation; in particular how species mass is estimated. We detect no pattern when applying an approach used by previous studies, where each species body mass is represented by two different numbers, one being the individual that happened to be used for BMR estimates of that species. However, this approach may compromise the analysis. When using a single value of body mass for each species, whether representing a single individual, or available species mean, our findings provide evidence that brain mass (independent of body mass and BMR are correlated. These findings are thus consistent with the hypothesis that large brains evolve when the payoff for increased brain mass is greater than the energetic cost they incur.

  10. Positron emission tomography assessment of effects of benzodiazepines on regional glucose metabolic rate in patients with anxiety disorder

    Energy Technology Data Exchange (ETDEWEB)

    Buchsbaum, M.S.; Wu, J.; Haier, R.; Hazlett, E.; Ball, R.; Katz, M.; Sokolski, K.; Lagunas-Solar, M.; Langer, D.

    1987-06-22

    Patients with generalized anxiety disorder (n = 18) entered a 21-day, double-blind, placebo-controlled random assignment trial of clorazepate. Positron emission tomography with YF-deoxyglucose was carried out before and after treatment. Decreases in glucose metabolic rate in visual cortex and relative increases in the basal ganglia and thalamus were found. A correlation between regional changes in metabolic rate and regional benzodiazepine receptor binding density from other human autopsy studies was observed; brain regions highest in receptor density showed the greatest decrease in rate.

  11. Auxin metabolism rates and implications for plant development

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    Eric M Kramer

    2015-03-01

    Full Text Available Studies of auxin metabolism rarely express their results as a metabolic rate, although the data obtained would often permit such a calculation to be made. We analyze data from 31 previously published papers to quantify the rates of auxin biosynthesis, conjugation, conjugate hydrolysis, and catabolism in seed plants. Most metabolic pathways have rates in the range 10 nM/h to 1 μM/h, with the exception of auxin conjugation, which has rates as high as ~100 μM/h. The highest rates of auxin conjugation suggests that auxin metabolic sinks may be very small, perhaps as small as a single cell. By contrast, the relatively low rate of auxin biosynthesis requires plants to conserve and recycle auxin during long-distance transport. The consequences for plant development are discussed.

  12. Characterizing Microbial Diversity and the Potential for Metabolic Function at −15 °C in the Basal Ice of Taylor Glacier, Antarctica

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    Brent C. Christner

    2013-07-01

    Full Text Available Measurement of gases entrapped in clean ice from basal portions of the Taylor Glacier, Antarctica, revealed that CO2 ranged from 229 to 328 ppmv and O2 was near 20% of the gas volume. In contrast, vertically adjacent sections of the sediment laden basal ice contained much higher concentrations of CO2 (60,000 to 325,000 ppmv, whereas O2 represented 4 to 18% of the total gas volume. The deviation in gas composition from atmospheric values occurred concurrently with increased microbial cell concentrations in the basal ice profile, suggesting that in situ microbial processes (i.e., aerobic respiration may have altered the entrapped gas composition. Molecular characterization of 16S rRNA genes amplified from samples of the basal ice indicated a low diversity of bacteria, and most of the sequences characterized (87% were affiliated with the phylum, Firmicutes. The most abundant phylotypes in libraries from ice horizons with elevated CO2 and depleted O2 concentrations were related to the genus Paenisporosarcina, and 28 isolates from this genus were obtained by enrichment culturing. Metabolic experiments with Paenisporosarcina sp. TG14 revealed its capacity to conduct macromolecular synthesis when frozen in water derived from melted basal ice samples and incubated at −15 °C. The results support the hypothesis that the basal ice of glaciers and ice sheets are cryospheric habitats harboring bacteria with the physiological capacity to remain metabolically active and biogeochemically cycle elements within the subglacial environment.

  13. Metabolically Derived Human Ventilation Rates: A Revised Approach Based Upon Oxygen Consumption Rates (Final Report, 2009)

    Science.gov (United States)

    EPA announced the availability of the final report, Metabolically Derived Human Ventilation Rates: A Revised Approach Based Upon Oxygen Consumption Rates. This report provides a revised approach for calculating an individual's ventilation rate directly from their oxygen c...

  14. Increased heart rate variability but normal resting metabolic rate in hypocretin/orexin-deficient human narcolepsy.

    NARCIS (Netherlands)

    Fronczek, R.; Overeem, S.; Reijntjes, R.; Lammers, G.J.; Dijk, J.G.M.; Pijl, H.

    2008-01-01

    STUDY OBJECTIVES: We investigated autonomic balance and resting metabolic rate to explore their possible involvement in obesity in hypocretin/orexin-deficient narcoleptic subjects. METHODS: Resting metabolic rate (using indirect calorimetry) and variability in heart rate and blood pressure were dete

  15. Análise de taxa metabólica basal e composição corporal de idosos do sexo masculino antes e seis meses após exercícios de resistência Análisis de la tasa metabolica de descanso y la composición corporal en veteranos hombres antes y despues de seis meses de ejercicio de endurance Analysis of resting metabolic rate and body composition in elderly males before and after six months of endurance exercise

    Directory of Open Access Journals (Sweden)

    Hanna K.M. Antunes

    2005-02-01

    3 veces por semana (60 minutos en días alternados por seis meses con intensidad prescrita referente a la frecuencia cardiaca del umbral ventilatorio I (VT-1. Los voluntarios fueron sometidos a una evaluación de la composición corporal (DEXA; calorimetría indirecta, análisis sanguíneo y test ergoespirométrico. Después del período de estudio, fue observado un decrecimiento significativo en las hormonas tiroideas y cambios en el metabolismo basal en ambos grupos, pero no fueron observadas alteraciones en la composición corporal. En tanto, el grupo experimental presentó un aumento significativo en el consumo de oxigeno pico y en la carga de trabajo referente a la intensidad del VT-1. Los datos sugieren que un programa de ejercicios aeróbicos en la intensidad del VT-1 no es suficiente para provocar alteraciones favorables en el metabolismo basal y en la composición corporal de añosos, así mismo promueva beneficios cardiovasculares.The aim of this study was to compare basal metabolic rate and body composition before and after an endurance-type physical fitness program. The study involved 46 sedentary aging males, aged 60-75 (66.97 ± 4.80 years, who were randomly allocated to two groups: 1 control group, which was asked not to change their daily routine or join a regular physical fitness program; and 2 experimental group, who took part in an aerobic fitness program consisting of working on cycle ergometer three times a week (60 minutes on alternate days for six months, at heart rate corresponding to ventilatory threshold 1 (VT-1 intensity. Subjects were submitted to measurement of body composition (DEXA; indirect calorimetry, blood analysis and ergospirometric testing. After the study period, the authors found a significant decrease in thyroid hormones as well as basal metabolism changes in both groups, but no changes in body composition. The experimental group, however, showed a significant increase in peak oxygen uptake and workload at VT-1 intensity. The

  16. Crosstalks between myo-inositol metabolism, programmed cell death and basal immunity in Arabidopsis.

    Directory of Open Access Journals (Sweden)

    Ping Hong Meng

    Full Text Available BACKGROUND: Although it is a crucial cellular process required for both normal development and to face stress conditions, the control of programmed cell death in plants is not fully understood. We previously reported the isolation of ATXR5 and ATXR6, two PCNA-binding proteins that could be involved in the regulation of cell cycle or cell death. A yeast two-hybrid screen using ATXR5 as bait captured AtIPS1, an enzyme which catalyses the committed step of myo-inositol (MI biosynthesis. atips1 mutants form spontaneous lesions on leaves, raising the possibility that MI metabolism may play a role in the control of PCD in plants. In this work, we have characterised atips1 mutants to gain insight regarding the role of MI in PCD regulation. METHODOLOGY/PRINCIPAL FINDINGS: - lesion formation in atips1 mutants depends of light intensity, is due to PCD as evidenced by TUNEL labelling of nuclei, and is regulated by phytohormones such as salicylic acid - MI and galactinol are the only metabolites whose accumulation is significantly reduced in the mutant, and supplementation of the mutant with these compounds is sufficient to prevent PCD - the transcriptome profile of the mutant is extremely similar to that of lesion mimic mutants such as cpr5, or wild-type plants infected with pathogens. CONCLUSION/SIGNIFICANCE: Taken together, our results provide strong evidence for the role of MI or MI derivatives in the regulation of PCD. Interestingly, there are three isoforms of IPS in Arabidopsis, but AtIPS1 is the only one harbouring a nuclear localisation sequence, suggesting that nuclear pools of MI may play a specific role in PCD regulation and opening new research prospects regarding the role of MI in the prevention of tumorigenesis. Nevertheless, the significance of the interaction between AtIPS1 and ATXR5 remains to be established.

  17. Metabolic rates of giant pandas inform conservation strategies

    Science.gov (United States)

    Fei, Yuxiang; Hou, Rong; Spotila, James R.; Paladino, Frank V.; Qi, Dunwu; Zhang, Zhihe

    2016-06-01

    The giant panda is an icon of conservation and survived a large-scale bamboo die off in the 1980s in China. Captive breeding programs have produced a large population in zoos and efforts continue to reintroduce those animals into the wild. However, we lack sufficient knowledge of their physiological ecology to determine requirements for survival now and in the face of climate change. We measured resting and active metabolic rates of giant pandas in order to determine if current bamboo resources were sufficient for adding additional animals to populations in natural reserves. Resting metabolic rates were somewhat below average for a panda sized mammal and active metabolic rates were in the normal range. Pandas do not have exceptionally low metabolic rates. Nevertheless, there is enough bamboo in natural reserves to support both natural populations and large numbers of reintroduced pandas. Bamboo will not be the limiting factor in successful reintroduction.

  18. Microbial heterotrophic metabolic rates constrain the microbial carbon pump

    Digital Repository Service at National Institute of Oceanography (India)

    Robinson, C; Ramaiah, N.

    addition incubations are poised to discern the complex interactions between metabolic rate, community structure, and organic and inorganic nutrient availability. In a changing global environment, it is important to understand how increasing sea surface...

  19. Winter Is Coming: Seasonal Variation in Resting Metabolic Rate of the European Badger (Meles meles.

    Directory of Open Access Journals (Sweden)

    David W McClune

    Full Text Available Resting metabolic rate (RMR is a measure of the minimum energy requirements of an animal at rest, and can give an indication of the costs of somatic maintenance. We measured RMR of free-ranging European badgers (Meles meles to determine whether differences were related to sex, age and season. Badgers were captured in live-traps and placed individually within a metabolic chamber maintained at 20 ± 1°C. Resting metabolic rate was determined using an open-circuit respirometry system. Season was significantly correlated with RMR, but no effects of age or sex were detected. Summer RMR values were significantly higher than winter values (mass-adjusted mean ± standard error: 2366 ± 70 kJ⋅d(-1; 1845 ± 109 kJ⋅d(-1, respectively, with the percentage difference being 24.7%. While under the influence of anaesthesia, RMR was estimated to be 25.5% lower than the combined average value before administration, and after recovery from anaesthesia. Resting metabolic rate during the autumn and winter was not significantly different to allometric predictions of basal metabolic rate for mustelid species weighing 1 kg or greater, but badgers measured in the summer had values that were higher than predicted. Results suggest that a seasonal reduction in RMR coincides with apparent reductions in physical activity and body temperature as part of the overwintering strategy ('winter lethargy' in badgers. This study contributes to an expanding dataset on the ecophysiology of medium-sized carnivores, and emphasises the importance of considering season when making predictions of metabolic rate.

  20. The high rate of prevalence of CT-detected basal ganglia calcification in neuropsychiatric (CNS) brucellosis.

    Science.gov (United States)

    Mousa, A M; Muhtaseb, S A; Reddy, R R; Senthilselvan, A; Al-Mudallal, D S; Marafie, A A

    1987-12-01

    Of 65 cases presenting with neuropsychiatric manifestations of brucellosis (CNS-brucellosis), 9(13.8%) had CT-detected basal ganglia calcification (BGC). Of these, 5 had meningitis and 4 had psychiatric manifestations as presenting features. The diagnosis of brucellosis was made by the finding of consistent history and physical findings and the presence of significantly elevated antibody titres and/or positive culture in the blood and/or CSF. In all the cases, BGC was in the form of punctate hyperdense non-enhancing shadows with average density 44.5-58.4 and maximum density 49-64HU. The calcification was unilateral in 3 cases, bilateral and symmetrical in 4 and bilateral but asymmetrical in 2. None of the cases had other predisposing conditions to BGC and in one of the cases did specific anti-brucella treatment effect a detectable change in the BGC. The finding of CT-detected BGC in patients coming from areas endemic for brucellosis should alert physicians to the possibility of underlying brucellar infection.

  1. Singing can improve speech function in aphasics associated with intact right basal ganglia and preserve right temporal glucose metabolism: Implications for singing therapy indication.

    Science.gov (United States)

    Akanuma, Kyoko; Meguro, Kenichi; Satoh, Masayuki; Tashiro, Manabu; Itoh, Masatoshi

    2016-01-01

    Clinically, we know that some aphasic patients can sing well despite their speech disturbances. Herein, we report 10 patients with non-fluent aphasia, of which half of the patients improved their speech function after singing training. We studied ten patients with non-fluent aphasia complaining of difficulty finding words. All had lesions in the left basal ganglia or temporal lobe. They selected the melodies they knew well, but which they could not sing. We made a new lyric with a familiar melody using words they could not name. The singing training using these new lyrics was performed for 30 minutes once a week for 10 weeks. Before and after the training, their speech functions were assessed by language tests. At baseline, 6 of them received positron emission tomography to evaluate glucose metabolism. Five patients exhibited improvements after intervention; all but one exhibited intact right basal ganglia and left temporal lobes, but all exhibited left basal ganglia lesions. Among them, three subjects exhibited preserved glucose metabolism in the right temporal lobe. We considered that patients who exhibit intact right basal ganglia and left temporal lobes, together with preserved right hemispheric glucose metabolism, might be an indication of the effectiveness of singing therapy.

  2. Drosophila larvae lacking the bcl-2 gene, buffy, are sensitive to nutrient stress, maintain increased basal target of rapamycin (Tor signaling and exhibit characteristics of altered basal energy metabolism

    Directory of Open Access Journals (Sweden)

    Monserrate Jessica P

    2012-07-01

    Full Text Available Abstract Background B cell lymphoma 2 (Bcl-2 proteins are the central regulators of apoptosis. The two bcl-2 genes in Drosophila modulate the response to stress-induced cell death, but not developmental cell death. Because null mutants are viable, Drosophila provides an optimum model system to investigate alternate functions of Bcl-2 proteins. In this report, we explore the role of one bcl-2 gene in nutrient stress responses. Results We report that starvation of Drosophila larvae lacking the bcl-2 gene, buffy, decreases survival rate by more than twofold relative to wild-type larvae. The buffy null mutant reacted to starvation with the expected responses such as inhibition of target of rapamycin (Tor signaling, autophagy initiation and mobilization of stored lipids. However, the autophagic response to starvation initiated faster in larvae lacking buffy and was inhibited by ectopic buffy. We demonstrate that unusually high basal Tor signaling, indicated by more phosphorylated S6K, was detected in the buffy mutant and that removal of a genomic copy of S6K, but not inactivation of Tor by rapamycin, reverted the precocious autophagy phenotype. Instead, Tor inactivation also required loss of a positive nutrient signal to trigger autophagy and loss of both was sufficient to activate autophagy in the buffy mutant even in the presence of enforced phosphoinositide 3-kinase (PI3K signaling. Prior to starvation, the fed buffy mutant stored less lipid and glycogen, had high lactate levels and maintained a reduced pool of cellular ATP. These observations, together with the inability of buffy mutant larvae to adapt to nutrient restriction, indicate altered energy metabolism in the absence of buffy. Conclusions All animals in their natural habitats are faced with periods of reduced nutrient availability. This study demonstrates that buffy is required for adaptation to both starvation and nutrient restriction. Thus, Buffy is a Bcl-2 protein that plays an

  3. Mean-field modeling of the basal ganglia-thalamocortical system. I Firing rates in healthy and parkinsonian states.

    Science.gov (United States)

    van Albada, S J; Robinson, P A

    2009-04-21

    Parkinsonism leads to various electrophysiological changes in the basal ganglia-thalamocortical system (BGTCS), often including elevated discharge rates of the subthalamic nucleus (STN) and the output nuclei, and reduced activity of the globus pallidus external (GPe) segment. These rate changes have been explained qualitatively in terms of the direct/indirect pathway model, involving projections of distinct striatal populations to the output nuclei and GPe. Although these populations partly overlap, evidence suggests dopamine depletion differentially affects cortico-striato-pallidal connection strengths to the two pallidal segments. Dopamine loss may also decrease the striatal signal-to-noise ratio, reducing both corticostriatal coupling and striatal firing thresholds. Additionally, nigrostriatal degeneration may cause secondary changes including weakened lateral inhibition in the GPe, and mesocortical dopamine loss may decrease intracortical excitation and especially inhibition. Here a mean-field model of the BGTCS is presented with structure and parameter estimates closely based on physiology and anatomy. Changes in model rates due to the possible effects of dopamine loss listed above are compared with experiment. Our results suggest that a stronger indirect pathway, possibly combined with a weakened direct pathway, is compatible with empirical evidence. However, altered corticostriatal connection strengths are probably not solely responsible for substantially increased STN activity often found. A lower STN firing threshold, weaker intracortical inhibition, and stronger striato-GPe inhibition help explain the relatively large increase in STN rate. Reduced GPe-GPe inhibition and a lower GPe firing threshold can account for the comparatively small decrease in GPe rate frequently observed. Changes in cortex, GPe, and STN help normalize the cortical rate, also in accord with experiments. The model integrates the basal ganglia into a unified framework along with an

  4. Larval developmental rate, metabolic rate and future growth performance in Atlantic salmon

    DEFF Research Database (Denmark)

    Serrano, Jonathan Vaz; Åberg, Madelene; Gjoen, Hans Magnus;

    2009-01-01

    Previous studies in salmonids suggest a link between larval developmental rate, metabolic rate, and future growth. However, the connection between growth during exogenous and endogenous feeding is still debated. In the current study, a positive relationship between larval developmental rate, quan...

  5. Dopamine modulates metabolic rate and temperature sensitivity in Drosophila melanogaster.

    Directory of Open Access Journals (Sweden)

    Taro Ueno

    Full Text Available Homeothermal animals, such as mammals, maintain their body temperature by heat generation and heat dissipation, while poikilothermal animals, such as insects, accomplish it by relocating to an environment of their favored temperature. Catecholamines are known to regulate thermogenesis and metabolic rate in mammals, but their roles in other animals are poorly understood. The fruit fly, Drosophila melanogaster, has been used as a model system for the genetic studies of temperature preference behavior. Here, we demonstrate that metabolic rate and temperature sensitivity of some temperature sensitive behaviors are regulated by dopamine in Drosophila. Temperature-sensitive molecules like dTrpA1 and shi(ts induce temperature-dependent behavioral changes, and the temperature at which the changes are induced were lowered in the dopamine transporter-defective mutant, fumin. The mutant also displays a preference for lower temperatures. This thermophobic phenotype was rescued by the genetic recovery of the dopamine transporter in dopamine neurons. Flies fed with a dopamine biosynthesis inhibitor (3-iodo-L-tyrosine, which diminishes dopamine signaling, exhibited preference for a higher temperature. Furthermore, we found that the metabolic rate is up-regulated in the fumin mutant. Taken together, dopamine has functions in the temperature sensitivity of behavioral changes and metabolic rate regulation in Drosophila, as well as its previously reported functions in arousal/sleep regulation.

  6. Metabolism and Aging : Effects of Cold Exposure on Metabolic Rate, Body Composition, and Longevity in Mice

    NARCIS (Netherlands)

    Vaanholt, Lobke M.; Daan, Serge; Schubert, Kristin A.; Visser, G. Henk

    2009-01-01

    The proposition that increased energy expenditure shortens life has a long history. The rate-of-living theory ( Pearl 1928) states that life span and average mass-specific metabolic rate are inversely proportional. Originally based on interspecific allometric comparisons between species of mammals,

  7. MR spectroscopy-based brain metabolite profiling in propionic acidaemia: metabolic changes in the basal ganglia during acute decompensation and effect of liver transplantation

    Directory of Open Access Journals (Sweden)

    McKiernan Patrick J

    2011-05-01

    Full Text Available Abstract Background Propionic acidaemia (PA results from deficiency of Propionyl CoA carboxylase, the commonest form presenting in the neonatal period. Despite best current management, PA is associated with severe neurological sequelae, in particular movement disorders resulting from basal ganglia infarction, although the pathogenesis remains poorly understood. The role of liver transplantation remains controversial but may confer some neuro-protection. The present study utilises quantitative magnetic resonance spectroscopy (MRS to investigate brain metabolite alterations in propionic acidaemia during metabolic stability and acute encephalopathic episodes. Methods Quantitative MRS was used to evaluate brain metabolites in eight children with neonatal onset propionic acidaemia, with six elective studies acquired during metabolic stability and five studies during acute encephalopathic episodes. MRS studies were acquired concurrently with clinically indicated MR imaging studies at 1.5 Tesla. LCModel software was used to provide metabolite quantification. Comparison was made with a dataset of MRS metabolite concentrations from a cohort of children with normal appearing MR imaging. Results MRI findings confirm the vulnerability of basal ganglia to infarction during acute encephalopathy. We identified statistically significant decreases in basal ganglia glutamate+glutamine and N-Acetylaspartate, and increase in lactate, during encephalopathic episodes. In white matter lactate was significantly elevated but other metabolites not significantly altered. Metabolite data from two children who had received liver transplantation were not significantly different from the comparator group. Conclusions The metabolite alterations seen in propionic acidaemia in the basal ganglia during acute encephalopathy reflect loss of viable neurons, and a switch to anaerobic respiration. The decrease in glutamine + glutamate supports the hypothesis that they are consumed to

  8. Metabolic rate affects adult life span independently of developmental rate in parasitoid wasps

    NARCIS (Netherlands)

    Seyahooei, M.A.; van Alphen, J.J.M.; Kraaijeveld, K.

    2011-01-01

    Developmental time and body size correlate with lifespan in a wide range of taxa, although not in insect parasitoids. When the rate of development is independent of adult metabolic rate, adult lifespan is free to adapt to the adult environment. We suggest that interspecific variation in intrinsic ad

  9. Dietary cystine level affects metabolic rate and glycaemic control in adult mice.

    Science.gov (United States)

    Elshorbagy, Amany K; Church, Chris; Valdivia-Garcia, Maria; Smith, A David; Refsum, Helga; Cox, Roger

    2012-04-01

    Plasma total cysteine (tCys) is strongly and independently associated with obesity in large human cohorts, but whether the association is causal is unknown. Dietary cyst(e)ine increases weight gain in some rodent models. We investigated the body composition, metabolic rate and metabolic phenotype of mature C3H/HeH mice assigned to low-cystine (LC) or high-cystine (HC) diets for 12 weeks. Compared to LC mice, HC mice gained more weight (P=.004 for 12-week weight gain %), with increased fat mass and lean mass, and lowered O₂ consumption and CO₂ production by calorimetry. The HC mice had 30% increase in intestinal fat/body weight % (P=.003) and ∼twofold elevated hepatic triglycerides (P=.046), with increased expression of hepatic lipogenic factors, peroxisome proliferator-activated receptor-γ and sterol regulatory element binding protein-1. Gene expression of both basal and catecholamine-stimulated lipolytic enzymes, adipose triglyceride lipase and hormone-sensitive lipase was inhibited in HC mice adipose tissue. The HC mice also had elevated fasting glucose (7.0 vs. 4.5 mmol/L, Pcystine intake promotes adiposity and an adverse metabolic phenotype in mice, indicating that the positive association of plasma tCys with obesity in humans may be causal.

  10. The determination of standard metabolic rate in fishes

    DEFF Research Database (Denmark)

    Chabot, Denis; Steffensen, John Fleng; Farrell, A.P.

    2016-01-01

    This review and data analysis outline how fish biologists should most reliably estimate the minimal amount of oxygen needed by a fish to support its aerobic metabolic rate (termed standard metabolic rate; SMR). By reviewing key literature, it explains the theory, terminology and challenges...... underlying SMR measurements in fishes, which are almost always made using respirometry (which measures oxygen uptake, ṀO2 ). Then, the practical difficulties of measuring SMR when activity of the fish is not quantitatively evaluated are comprehensively explored using 85 examples of ṀO2 data from different...... fishes and one crustacean, an analysis that goes well beyond any previous attempt. The main objective was to compare eight methods to estimate SMR. The methods were: average of the lowest 10 values (low10) and average of the 10% lowest ṀO2 values, after removing the five lowest ones as outliers (low10...

  11. [Specific growth rate and the rate of energy metabolism in the ontogenesis of axolotl, Ambystoma mexicanum (Amphibia: Ambystomatidae)].

    Science.gov (United States)

    Vladimirova, I G; Kleĭmenov, S Iu; Alekseeva, T A; Radzinskaia, L I

    2003-01-01

    Concordant changes in the rate of energy metabolism and specific growth rate of axolotls have been revealed. Several periods of ontogeny are distinguished, which differ in the ratio of energy metabolism to body weight and, therefore, are described by different allometric equations. It is suggested that the specific growth rate of an animal determines the type of dependence of energy metabolism on body weight.

  12. The tacrolimus metabolism rate influences renal function after kidney transplantation.

    Directory of Open Access Journals (Sweden)

    Gerold Thölking

    Full Text Available The effective calcineurin inhibitor (CNI tacrolimus (Tac is an integral part of the standard immunosuppressive regimen after renal transplantation (RTx. However, as a potent CNI it has nephrotoxic potential leading to impaired renal function in some cases. Therefore, it is of high clinical impact to identify factors which can predict who is endangered to develop CNI toxicity. We hypothesized that the Tac metabolism rate expressed as the blood concentration normalized by the dose (C/D ratio is such a simple predictor. Therefore, we analyzed the impact of the C/D ratio on kidney function after RTx. Renal function was analyzed 1, 2, 3, 6, 12 and 24 months after RTx in 248 patients with an immunosuppressive regimen including basiliximab, tacrolimus, mycophenolate mofetil and prednisolone. According to keep the approach simple, patients were split into three C/D groups: fast, intermediate and slow metabolizers. Notably, compared with slow metabolizers fast metabolizers of Tac showed significantly lower estimated glomerular filtration rate (eGFR values at all the time points analyzed. Moreover, fast metabolizers underwent more indication renal biopsies (p = 0.006 which revealed a higher incidence of CNI nephrotoxicity (p = 0.015 and BK nephropathy (p = 0.024 in this group. We herein identified the C/D ratio as an easy calculable risk factor for the development of CNI nephrotoxicity and BK nephropathy after RTx. We propose that the simple C/D ratio should be taken into account early in patient's risk management strategies.

  13. Oligo-carrageenan kappa increases NADPH, ascorbate and glutathione syntheses and TRR/TRX activities enhancing photosynthesis, basal metabolism, and growth in Eucalyptus trees

    Directory of Open Access Journals (Sweden)

    Alberto eGonzález

    2014-10-01

    Full Text Available In order to analyze the effect of OC kappa in redox status, photosynthesis, basal metabolism and growth in Eucalyptus globulus, trees were treated with water (control, with OC kappa at 1 mg mL-1, or treated with inhibitors of NAD(PH, ascorbate (ASC and glutathione (GSH syntheses and thioredoxin reductase (TRR activity, CHS-828, lycorine, buthionine sulfoximine (BSO and auranofin, respectively, and with OC kappa, and cultivated for 4 months. Treatment with OC kappa induced an increase in NADPH, ASC, and GSH syntheses, TRR and thioredoxin (TRX activities, photosynthesis, growth and activities of basal metabolism enzymes such as rubisco, glutamine synthetase (GlnS, adenosine 5´-phosphosulfate reductase (APR, involved in C, N and S assimilation, respectively, Krebs cycle and purine/pyrimidine synthesis enzymes. Treatment with inhibitors and OC kappa showed that increases in ASC, GSH and TRR/TRX enhanced NADPH synthesis, increases in NADPH and TRR/TRX enhanced ASC and GSH syntheses, and only the increase in NADPH enhanced TRR/TRX activities. In addition, the increase in NADPH, ASC, GSH and TRR/TRX enhanced photosynthesis and growth. Moreover, the increase in NADPH, ASC and TRR/TRX enhanced activities of rubisco, Krebs cycle and purine/pyrimidine synthesis enzymes, the increase in GSH, NADPH, and TRR/TRX enhanced APR activity, and the increase in NADPH and TRR/TRX enhanced GlnS activity. Thus, OC kappa increases NADPH, ASC and GSH syntheses leading to a more reducing redox status, the increase in NADPH, ASC, GSH syntheses and TRR/TRX activities are cross-talking events leading to activation of photosynthesis, basal metabolism and growth in Eucalyptus trees.

  14. Cold- and exercise-induced peak metabolic rates in tropical birds.

    Science.gov (United States)

    Wiersma, Popko; Chappell, Mark A; Williams, Joseph B

    2007-12-26

    Compared with temperate birds, tropical birds have low reproductive rates, slow development as nestlings, and long lifespans. These "slow" life history traits are thought to be associated with reduced energy expenditure, or a slow "pace of life." To test predictions from this hypothesis, we measured exercise-induced peak metabolic rates (PMR(E)) in 45 species of tropical lowland forest birds and compared these data with PMR(E) for three temperate species. We also compared cold-induced PMR (PMR(C)) with PMR(E) in the same individuals of 19 tropical species. Tropical birds had a 39% lower PMR(E) than did the temperate species. In tropical birds, PMR(C) and PMR(E) scaled similarly with body mass (M(b)), but PMR(E) was 47% higher than PMR(C). PMR(E) averaged 6.44 x basal metabolic rate (BMR) and PMR(C) averaged 4.52 x BMR. The slope of the equation relating PMR(E) to M(b) exceeded the slope for the equation for BMR vs. M(b), whereas slopes for the equations of PMR(C) and BMR vs. M(b) did not differ. M(b)-adjusted residuals of PMR(E) were positively correlated with residual BMR, whereas residual PMR(C) and residual BMR were not correlated. PMR(E) and PMR(C) were not correlated after we corrected for M(b). Temperate birds maintained their body temperature at an 8.6 degrees C lower average air temperature than did tropical species. The lower PMR(E) values in tropical species suggest that their suite of life history traits on the slow end of the life history continuum are associated with reduced metabolic rates.

  15. Correlation between metabolic reduction rates and electron affinity of nitroheterocycles

    Energy Technology Data Exchange (ETDEWEB)

    Olive, P.L.

    1979-11-01

    Nitroheterocyclic compounds can selectively sensitize hypoxic (tumor) cells to radiation damage in vitro. However, results in vivo have generally been less optimistic, inasmuch as metabolic reduction of these drugs not only limits effective lifetime but also produces metabolic intermediates with marked cytotoxic and carcinogenic activity. With three reducing systems in vitro, E. coli B/r, mouse L-929 cells, and mouse liver microsomes, the rate of nitroreduction of several nitroheterocycles was found to be proportional to their electron affinity. Since nitroreduction has previously been correlated with subsequent cytotoxicity, DNA damage, and mutagenicity, the present results suggest that improvements in the therapeutic efficacy of nitroheterocycles (i.e., sensitization without toxicity and carcinogenicity) will be dependent on development of drugs with more appropriate pharmacological properties.

  16. Field metabolic rate and PCB adipose tissue deposition efficiency in East Greenland polar bears derived from contaminant monitoring data.

    Science.gov (United States)

    Pavlova, Viola; Nabe-Nielsen, Jacob; Dietz, Rune; Svenning, Jens-Christian; Vorkamp, Katrin; Rigét, Frank Farsø; Sonne, Christian; Letcher, Robert J; Grimm, Volker

    2014-01-01

    Climate change will increasingly affect the natural habitat and diet of polar bears (Ursus maritimus). Understanding the energetic needs of polar bears is therefore important. We developed a theoretical method for estimating polar bear food consumption based on using the highly recalcitrant polychlorinated biphenyl (PCB) congener, 2,2',4,4',55-hexaCB (CB153) in bear adipose tissue as an indicator of food intake. By comparing the CB153 tissue concentrations in wild polar bears with estimates from a purposely designed individual-based model, we identified the possible combinations of field metabolic rates (FMR) and CB153 deposition efficiencies in East Greenland polar bears. Our simulations indicate that if 30% of the CB153 consumed by polar bear individuals were deposited into their adipose tissue, the corresponding FMR would be only two times the basal metabolic rate. In contrast, if the modelled CB153 deposition efficiency were 10%, adult polar bears would require six times more energy than that needed to cover basal metabolism. This is considerably higher than what has been assumed for polar bears in previous studies though it is similar to FMRs found in other marine mammals. An implication of this result is that even relatively small reductions in future feeding opportunities could impact the survival of East Greenland polar bears.

  17. Field metabolic rate and PCB adipose tissue deposition efficiency in East Greenland polar bears derived from contaminant monitoring data.

    Directory of Open Access Journals (Sweden)

    Viola Pavlova

    Full Text Available Climate change will increasingly affect the natural habitat and diet of polar bears (Ursus maritimus. Understanding the energetic needs of polar bears is therefore important. We developed a theoretical method for estimating polar bear food consumption based on using the highly recalcitrant polychlorinated biphenyl (PCB congener, 2,2',4,4',55-hexaCB (CB153 in bear adipose tissue as an indicator of food intake. By comparing the CB153 tissue concentrations in wild polar bears with estimates from a purposely designed individual-based model, we identified the possible combinations of field metabolic rates (FMR and CB153 deposition efficiencies in East Greenland polar bears. Our simulations indicate that if 30% of the CB153 consumed by polar bear individuals were deposited into their adipose tissue, the corresponding FMR would be only two times the basal metabolic rate. In contrast, if the modelled CB153 deposition efficiency were 10%, adult polar bears would require six times more energy than that needed to cover basal metabolism. This is considerably higher than what has been assumed for polar bears in previous studies though it is similar to FMRs found in other marine mammals. An implication of this result is that even relatively small reductions in future feeding opportunities could impact the survival of East Greenland polar bears.

  18. Effect of growth rate and body mass on resting metabolic rate in galliform chicks

    NARCIS (Netherlands)

    Dietz, MW; Drent, RH

    1997-01-01

    In this study, we asked whether within-species variation in chick resting metabolic rate was related to variation in growth and whether this relationship changed during development in three galliform species (turkey, Meleagris gallopavo, guinea fowl, Numida meleagris, and Japanese quail, Coturnix co

  19. Increased metabolic turnover rate and transcapillary escape rate of albumin in long-term juvenile diabetics

    DEFF Research Database (Denmark)

    Parving, H H; Rossing, N; Sander, E

    1975-01-01

    smaller than 0.05). The previously reported decrease in the intravascular albumin mass in long-term diabetics was thus confirmed by an average of 59.0 g/m2 surface area, compared with a normal value of 71.7 g/m2-(minus18%) (P smaller than 0.005). The albumin metabolic rate was increased, the fractional...

  20. Metabolic hormones regulate basal and growth hormone-dependent igf2 mRNA level in primary cultured coho salmon hepatocytes: effects of insulin, glucagon, dexamethasone, and triiodothyronine.

    Science.gov (United States)

    Pierce, A L; Dickey, J T; Felli, L; Swanson, P; Dickhoff, W W

    2010-03-01

    Igf1 and Igf2 stimulate growth and development of vertebrates. Circulating Igfs are produced by the liver. In mammals, Igf1 mediates the postnatal growth-promoting effects of growth hormone (Gh), whereas Igf2 stimulates fetal and placental growth. Hepatic Igf2 production is not regulated by Gh in mammals. Little is known about the regulation of hepatic Igf2 production in nonmammalian vertebrates. We examined the regulation of igf2 mRNA level by metabolic hormones in primary cultured coho salmon hepatocytes. Gh, insulin, the glucocorticoid agonist dexamethasone (Dex), and glucagon increased igf2 mRNA levels, whereas triiodothyronine (T(3)) decreased igf2 mRNA levels. Gh stimulated igf2 mRNA at physiological concentrations (0.25x10(-9) M and above). Insulin strongly enhanced Gh stimulation of igf2 at low physiological concentrations (10(-11) M and above), and increased basal igf2 (10(-8) M and above). Dex stimulated basal igf2 at concentrations comparable to those of stressed circulating cortisol (10(-8) M and above). Glucagon stimulated basal and Gh-stimulated igf2 at supraphysiological concentrations (10(-7) M and above), whereas T(3) suppressed basal and Gh-stimulated igf2 at the single concentration tested (10(-7) M). These results show that igf2 mRNA level is highly regulated in salmon hepatocytes, suggesting that liver-derived Igf2 plays a significant role in salmon growth physiology. The synergistic regulation of igf2 by insulin and Gh in salmon hepatocytes is similar to the regulation of hepatic Igf1 production in mammals.

  1. Transcription factor ATF4 directs basal and stress-induced gene expression in the unfolded protein response and cholesterol metabolism in the liver.

    Science.gov (United States)

    Fusakio, Michael E; Willy, Jeffrey A; Wang, Yongping; Mirek, Emily T; Al Baghdadi, Rana J T; Adams, Christopher M; Anthony, Tracy G; Wek, Ronald C

    2016-05-01

    Disturbances in protein folding and membrane compositions in the endoplasmic reticulum (ER) elicit the unfolded protein response (UPR). Each of three UPR sensory proteins-PERK (PEK/EIF2AK3), IRE1, and ATF6-is activated by ER stress. PERK phosphorylation of eIF2 represses global protein synthesis, lowering influx of nascent polypeptides into the stressed ER, coincident with preferential translation of ATF4 (CREB2). In cultured cells, ATF4 induces transcriptional expression of genes directed by the PERK arm of the UPR, including genes involved in amino acid metabolism, resistance to oxidative stress, and the proapoptotic transcription factor CHOP (GADD153/DDIT3). In this study, we characterize whole-body and tissue-specific ATF4-knockout mice and show in liver exposed to ER stress that ATF4 is not required for CHOP expression, but instead ATF6 is a primary inducer. RNA-Seq analysis indicates that ATF4 is responsible for a small portion of the PERK-dependent UPR genes and reveals a requirement for expression of ATF4 for expression of genes involved in oxidative stress response basally and cholesterol metabolism both basally and under stress. Consistent with this pattern of gene expression, loss of ATF4 resulted in enhanced oxidative damage, and increased free cholesterol in liver under stress accompanied by lowered cholesterol in sera.

  2. Identical metabolic rate and thermal conductance in Rock Sandpiper (Calidris ptilocnemis) subspecies with contrasting nonbreeding life histories

    Science.gov (United States)

    Ruthrauff, Daniel R.; Dekinga, Anne; Gill, Robert E.; Piersma, Theunis

    2013-01-01

    Closely related species or subspecies can exhibit metabolic differences that reflect site-specific environmental conditions. Whether such differences represent fixed traits or flexible adjustments to local conditions, however, is difficult to predict across taxa. The nominate race of Rock Sandpiper (Calidris ptilocnemis) exhibits the most northerly nonbreeding distribution of any shorebird in the North Pacific, being common during winter in cold, dark locations as far north as upper Cook Inlet, Alaska (61°N). By contrast, the tschuktschorum subspecies migrates to sites ranging from about 59°N to more benign locations as far south as ~37°N. These distributional extremes exert contrasting energetic demands, and we measured common metabolic parameters in the two subspecies held under identical laboratory conditions to determine whether differences in these parameters are reflected by their nonbreeding life histories. Basal metabolic rate and thermal conductance did not differ between subspecies, and the subspecies had a similar metabolic response to temperatures below their thermoneutral zone. Relatively low thermal conductance values may, however, reflect intrinsic metabolic adaptations to northerly latitudes. In the absence of differences in basic metabolic parameters, the two subspecies’ nonbreeding distributions will likely be more strongly influenced by adaptations to regional variation in ecological factors such as prey density, prey quality, and foraging habitat.

  3. Both superficial and deep zone articular chondrocyte subpopulations exhibit the Crabtree effect but have different basal oxygen consumption rates.

    Science.gov (United States)

    Heywood, Hannah K; Knight, Martin M; Lee, David A

    2010-06-01

    In the absence of in vivo measurements, the oxygen concentration within articular cartilage is calculated from the balance between cellular oxygen consumption and mass transfer. Current estimates of the oxygen tension within articular cartilage are based on oxygen consumption data from full-depth tissue samples. However, superficial and deep cell subpopulations of articular cartilage express intrinsic metabolic differences. We test the hypothesis that the subpopulations differ with respect to their intrinsic oxygen consumption rate. Chondrocytes from the full cartilage thickness demonstrate enhanced oxygen consumption when deprived of glucose, consistent with the Crabtree phenomena. Chondrocyte subpopulations differ in the prevailing availability of oxygen and glucose, which decrease with distance from the cartilage-synovial fluid interface. Thus, we tested the hypothesis that the oxygen consumption of each subpopulation is modulated by nutrient availability, by examining the expression of the Crabtree effect. The deep cells had a greater oxygen consumption than the superficial cells (V(max) of 6.6 compared to 3.2 fmol/cell/h), consistent with our observations of mitochondrial volume (mean values 52.0 vs. 36.4 microm(3)/cell). Both populations expressed the Crabtree phenomena, with oxygen consumption increasing approximately 2.5-fold in response to glycolytic inhibition by glucose deprivation or 2-deoxyglucose. Over 90% of this increase was oligomycin-sensitive and thus accounted for by oxidative phosphorylation. The data contributes towards our understanding of chondrocyte energy metabolism and provides information valuable for the accurate calculation of the oxygen concentration that the cells experience in vivo. The work has further application to the optimisation of bioreactor design and engineered tissues.

  4. A short period of fasting before surgery conserves basal metabolism and suppresses catabolism according to indirect calorimetry performed under general anesthesia.

    Science.gov (United States)

    Yoshimura, Shinichiro; Fujita, Yoshihito; Hirate, Hiroyuki; Kusama, Nobuyoshi; Azami, Takafumi; Sobue, Kazuya

    2015-06-01

    It is recommended that the period of fasting before elective surgery should be shortened to facilitate a rapid recovery by preventing catabolism. We examined the effects of a short period of fasting on metabolism by performing indirect calorimetry (IC) under general anesthesia. A prospective observational study involving 26 consecutive patients who underwent elective surgery and whose metabolism was evaluated using IC during anesthesia was conducted. The patients were divided into two groups, those who fasted for 10 h (group L). Oxygen consumption, the volume of carbon dioxide emissions (VCO2), the respiratory quotient (RQ), resting energy expenditure (REE), and basal energy expenditure (BEE) were compared. The REE, VCO2, and RQ of group L (17.7 ± 2.3 kcal/kg/day, 118.5 ± 20.8 ml/min, and 0.71 ± 0.12, respectively) were significantly lower than those of group S (19.7 ± 2.3 kcal/kg/day, 143.6 ± 30.9 ml/min, and 0.81 ± 0.09, respectively) (P < 0.05). In group L, the relationship between REE and BEE was weaker (r(2) = 0.501) and the BEE-REE slope was less steep (REE = 0.419BEE + 509.477) than those seen in group S (r(2) = 0.749 and REE = 1.113BEE - 376.111, respectively). Our findings suggest that a short period of fasting (<8 h) before surgery is more strongly associated with the conservation of basal metabolism.

  5. Metabolism and aging: effects of cold exposure on metabolic rate, body composition, and longevity in mice.

    Science.gov (United States)

    Vaanholt, Lobke M; Daan, Serge; Schubert, Kristin A; Visser, G Henk

    2009-01-01

    The proposition that increased energy expenditure shortens life has a long history. The rate-of-living theory (Pearl 1928 ) states that life span and average mass-specific metabolic rate are inversely proportional. Originally based on interspecific allometric comparisons between species of mammals, the theory was later rejected on the basis of comparisons between taxa (e.g., birds have higher metabolic rates than mammals of the same size and yet live longer). It has rarely been experimentally tested within species. Here, we investigated the effects of increased energy expenditure, induced by cold exposure, on longevity in mice. Longevity was measured in groups of 60 male mice maintained at either 22 degrees C (WW) or 10 degrees C (CC) throughout adult life. Forty additional mice were maintained at both of these temperatures to determine metabolic rate (by stable isotope turnover, gas exchange, and food intake) as well as the mass of body and organs of subsets of animals at four different ages. Because energy expenditure might affect longevity by either accumulating damage or by instantaneously affecting mortality rate, we included a third group of mice exposed to 10 degrees C early in life and to 22 degrees C afterward (CW). Exposure to cold increased mean daily energy expenditure by ca. 48% (from 47.8 kJ d(-1) in WW to 70.6 kJ d(-1) in CC mice, with CW intermediate at 59.9 kJ d(-1)). However, we observed no significant differences in median life span among the groups (WW, 832 d; CC, 834 d; CW, 751 d). CC mice had reduced body mass (lifetime mean 30.7 g) compared with WW mice (33.8 g), and hence their lifetime energy potential (LEP) per gram whole-body mass had an even larger excess than per individual. Greenberg ( 1999 ) has pointed out that the size of the energetically costly organs, rather than that of the whole body, may be relevant for the rate-of-living idea. We therefore expressed LEP also in terms of energy expenditure per gram dry lean mass or per gram

  6. Hemispherical dominance of glucose metabolic rate in the brain of the 'normal' ageing population

    NARCIS (Netherlands)

    Cutts, DA; Maguire, RP; Leenders, KL; Spyrou, NM

    2004-01-01

    In the 'normal' ageing brain a decrease in the cerebral metabolic rate has been determined across many brain regions. This study determines whether age differences would affect metabolic rates in regions and different hemispheres of the brain. The regional metabolic rate of glucose (rCMRGlu) was exa

  7. Energy metabolism in astrocytes: high rate of oxidative metabolism and spatiotemporal dependence on glycolysis/glycogenolysis.

    Science.gov (United States)

    Hertz, Leif; Peng, Liang; Dienel, Gerald A

    2007-02-01

    Astrocytic energy demand is stimulated by K(+) and glutamate uptake, signaling processes, responses to neurotransmitters, Ca(2+) fluxes, and filopodial motility. Astrocytes derive energy from glycolytic and oxidative pathways, but respiration, with its high-energy yield, provides most adenosine 5' triphosphate (ATP). The proportion of cortical oxidative metabolism attributed to astrocytes ( approximately 30%) in in vivo nuclear magnetic resonance (NMR) spectroscopic and autoradiographic studies corresponds to their volume fraction, indicating similar oxidation rates in astrocytes and neurons. Astrocyte-selective expression of pyruvate carboxylase (PC) enables synthesis of glutamate from glucose, accounting for two-thirds of astrocytic glucose degradation via combined pyruvate carboxylation and dehydrogenation. Together, glutamate synthesis and oxidation, including neurotransmitter turnover, generate almost as much energy as direct glucose oxidation. Glycolysis and glycogenolysis are essential for astrocytic responses to increasing energy demand because astrocytic filopodial and lamellipodial extensions, which account for 80% of their surface area, are too narrow to accommodate mitochondria; these processes depend on glycolysis, glycogenolysis, and probably diffusion of ATP and phosphocreatine formed via mitochondrial metabolism to satisfy their energy demands. High glycogen turnover in astrocytic processes may stimulate glucose demand and lactate production because less ATP is generated when glucose is metabolized via glycogen, thereby contributing to the decreased oxygen to glucose utilization ratio during brain activation. Generated lactate can spread from activated astrocytes via low-affinity monocarboxylate transporters and gap junctions, but its subsequent fate is unknown. Astrocytic metabolic compartmentation arises from their complex ultrastructure; astrocytes have high oxidative rates plus dependence on glycolysis and glycogenolysis, and their energetics is

  8. Metabolic rate covaries with fitness and the pace of the life history in the field.

    Science.gov (United States)

    Pettersen, Amanda K; White, Craig R; Marshall, Dustin J

    2016-05-25

    Metabolic rate reflects the 'pace of life' in every organism. Metabolic rate is related to an organism's capacity for essential maintenance, growth and reproduction-all of which interact to affect fitness. Although thousands of measurements of metabolic rate have been made, the microevolutionary forces that shape metabolic rate remain poorly resolved. The relationship between metabolic rate and components of fitness are often inconsistent, possibly because these fitness components incompletely map to actual fitness and often negatively covary with each other. Here we measure metabolic rate across ontogeny and monitor its effects on actual fitness (lifetime reproductive output) for a marine bryozoan in the field. We also measure key components of fitness throughout the entire life history including growth rate, longevity and age at the onset of reproduction. We found that correlational selection favours individuals with higher metabolic rates in one stage and lower metabolic rates in the other-individuals with similar metabolic rates in each developmental stage displayed the lowest fitness. Furthermore, individuals with the lowest metabolic rates lived for longer and reproduced more, but they also grew more slowly and took longer to reproduce initially. That metabolic rate is related to the pace of the life history in nature has long been suggested by macroevolutionary patterns but this study reveals the microevolutionary processes that probably generated these patterns.

  9. Physiological underpinnings associated with differences in pace of life and metabolic rate in north temperate and neotropical birds.

    Science.gov (United States)

    Jimenez, Ana Gabriela; Cooper-Mullin, Clara; Calhoon, Elisabeth A; Williams, Joseph B

    2014-07-01

    Animal life-history traits fall within limited ecological space with animals that have high reproductive rates having short lives, a continuum referred to as a "slow-fast" life-history axis. Animals of the same body mass at the slow end of the life-history continuum are characterized by low annual reproductive output and low mortality rate, such as is found in many tropical birds, whereas at the fast end, rates of reproduction and mortality are high, as in temperate birds. These differences in life-history traits are thought to result from trade-offs between investment in reproduction or self-maintenance as mediated by the biotic and abiotic environment. Thus, tropical and temperate birds provide a unique system to examine physiological consequences of life-history trade-offs at opposing ends of the "pace of life" spectrum. We have explored the implications of these trade-offs at several levels of physiological organization including whole-animal, organ systems, and cells. Tropical birds tend to have higher survival, slower growth, lower rates of whole-animal basal metabolic rate and peak metabolic rate, and smaller metabolically active organs compared with temperate birds. At the cellular level, primary dermal fibroblasts from tropical birds tend to have lower cellular metabolic rates and appear to be more resistant to oxidative cell stress than those of temperate birds. However, at the subcellular level, lipid peroxidation rates, a measure of the ability of lipid molecules within the cell membranes to thwart the propagation of oxidative damage, appear not to be different between tropical and temperate species. Nevertheless, lipids in mitochondrial membranes of tropical birds tend to have increased concentrations of plasmalogens (phospholipids with antioxidant properties), and decreased concentrations of cardiolipin (a complex phospholipid in the electron transport chain) compared with temperate birds.

  10. Effect of sedentary activities on resting metabolic rate.

    Science.gov (United States)

    Dietz, W H; Bandini, L G; Morelli, J A; Peers, K F; Ching, P L

    1994-03-01

    We examined the effect of television viewing on resting metabolic rate (RMR) in a cohort of 9 obese and 18 nonobese girls aged 10.4 +/- 1.1 y. RMR was measured while girls watched television, read, or sat quietly for 15 min. Movement was assessed by using activity monitors and a manual count of movements observed on a videotape. Absolute RMR was greater for the obese girls, but no significant treatment effect existed for absolute RMR within either group. Although measured activity did not differ, observed movements were greater when the girls were sitting quietly. Total observed and measured movements were significantly correlated with the CV of the minute-by-minute RMR. These results suggest that television viewing does not alter RMR. Although children appear to fidget more when sitting quietly than when they read or watch television, fidgeting appears to affect the minute-to-minute variation of RMR rather than the level of resting energy expenditure.

  11. Metabolic and Hormonal Determinants of Glomerular Filtration Rate and Renal Hemodynamics in Severely Obese Individuals

    Directory of Open Access Journals (Sweden)

    Edoardo Vitolo

    2016-10-01

    Full Text Available Objective: Renal function is often compromised in severe obesity. A true measurement of glomerular filtration rate (GFR is unusual, and how estimation formulae (EstForm perform in such individuals is unclear. We characterized renal function and hemodynamics in severely obese individuals, assessing the reliability of EstForm. Methods: We measured GFR (mGFR by iohexol plasma clearance, renal plasma flow (RPF by 123I-ortho-iodo-hippurate, basal and stimulated vascular renal indices, endothelium-dependent and -independent vasodilation using flow-mediated dilation (FMD as well as metabolic and hormonal profile in morbid, otherwise healthy, obese subjects. Results: Compared with mGFR, the better performing EstForm was CKD-EPI (5.3 ml/min/1.73 m2 bias by Bland-Altman analysis. mGFR was directly related with RPF, total and incremental glucose AUC, and inversely with PTH and h8 cortisol. Patients with mGFR below the median shown significantly higher PTH and lower vitamin D3. Basal or dynamic renal resistive index, FMD, pulse wave velocity were not related with mGFR. In an adjusted regression model, renal diameter and plasma flow remained related with mGFR (R2 = 0.67, accounting for 15% and 21% of mGFR variance, respectively. Conclusions: CKD-EPI formula should be preferred in morbid obesity; glucose increments during oral glucose tolerance test correlate with hyperfiltration; RPF and diameter are independent determinants of mGFR; slightly high PTH values, frequent in obesity, might influence mGFR.

  12. A validated disease specific prediction equation for resting metabolic rate in underweight patients with COPD

    Directory of Open Access Journals (Sweden)

    Anita Nordenson

    2010-09-01

    Full Text Available Anita Nordenson2, Anne Marie Grönberg1,2, Lena Hulthén1, Sven Larsson2, Frode Slinde11Department of Clinical Nutrition, Sahlgrenska Academy at University of Gothenburg, Göteborg, Sweden; 2Department of Internal Medicine/Respiratory Medicine and Allergology, Sahlgrenska Academy at University of Gothenburg, SwedenAbstract: Malnutrition is a serious condition in chronic obstructive pulmonary disease (COPD. Successful dietary intervention calls for calculations of resting metabolic rate (RMR. One disease-specific prediction equation for RMR exists based on mainly male patients. To construct a disease-specific equation for RMR based on measurements in underweight or weight-losing women and men with COPD, RMR was measured by indirect calorimetry in 30 women and 11 men with a diagnosis of COPD and body mass index <21 kg/m2. The following variables, possibly influencing RMR were measured: length, weight, middle upper arm circumference, triceps skinfold, body composition by dual energy x-ray absorptiometry and bioelectrical impedance, lung function, and markers of inflammation. Relations between RMR and measured variables were studied using univariate analysis according to Pearson. Gender and variables that were associated with RMR with a P value <0.15 were included in a forward multiple regression analysis. The best-fit multiple regression equation included only fat-free mass (FFM: RMR (kJ/day = 1856 + 76.0 FFM (kg. To conclude, FFM is the dominating factor influencing RMR. The developed equation can be used for prediction of RMR in underweight COPD patients.Keywords: pulmonary disease, chronic obstructive, basal metabolic rate, malnutrition, body composition

  13. Correlation Between Ecospace and Metabolic Rate of Marine Organisms Through Geologic Time

    Science.gov (United States)

    Duong, C.; Tenorio, A.; Heim, N. A.; Payne, J.

    2015-12-01

    Marine organisms are the most abundant fossils scientists have discovered in the fossil record. Various factors affect the survival rate of individual organisms and entire genera including metabolic rate, genetic diversity, environmental availability, and ecology. We however chose to focus our attention on studying mean metabolic rates in correlation to life modes. A marine organism's life mode is determined by three criteria: tiering, motility, and feeding mechanism. We believe an organism's life mode has an effect on its survivorship, especially since ecospace is the "primary determinant of routine metabolic rate for marine organisms" (Seibel & Drazen 2007). Using the metabolic equation, we were able to plot metabolic rate changes for various life modes over time. Seibel and Drazen (2007) explain that "metabolic variation in the ocean results from interspecific differences in ecological energy demand," thus allowing us to hypothesize that with different combinations of life modes, different marine organisms will have varying metabolic rates. To further compare our data, we created a heatmap to show the change in metabolic rates over the last 540 million years. Based on the collection of data, metabolic rates of marine organisms have shown an increasing trend. When analyzing ecospaces, pelagic (living in the water column), free moving organisms have relatively high metabolic rates in comparison to other modes of tiering. In other life modes, there's a general trend of genera maintaining a stabilized and moderate metabolic rate that is neither extremely high nor low.

  14. Assessing Metabolic Syndrome Through Increased Heart Rate During Exercise

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    Masoumeh Sadeghi

    2016-12-01

    Full Text Available The present study aimed to assess changes in resting and maximum heart rates as primary indicators of cardiac autonomic function in metabolic syndrome (MetS patients and to determine their value for discriminating MetS from non-MetS. 468 participants were enrolled in this cross-sectional study and assessed according to the updated adult treatment panel III (ATP-III definition of MetS. Resting and maximum heart rates were recorded following the Bruce protocol during an exercise. A receiver operating characteristic (ROC curve was used to identify the best cutoff point for discriminating MetS from the non-MetS state. 194 participants (41.5% were diagnosed as MetS. The mean resting heart rate (RHR was not statistically different between the two groups (P=0.078. However, the mean maximum heart (MHR rate was considerably higher in participants with MetS (142.37±14.84 beats per min compared to the non-MetS group (134.62±21.63 beats per min (P<0.001. In the MetS group, the MHR was positively correlated with the serum triglyceride level (β=0.185, P=0.033 and was inversely associated with age (β=-0.469, P<0.001. The MHR had a moderate value for discriminating MetS from the non-MetS state (c=0.580, P=0.004 with the optimal cutoff point of 140 beats per min. In MetS patients, the MHR was significantly greater compared to non-MetS subjects and was directly correlated with serum triglyceride levels and inversely with advanced age. Moreover, MHR can be used as a suspicious indicator for identifying MetS.

  15. Effect of feed and bleed rate on hybridoma cells in an acoustic perfusion bioreactor: Metabolic analysis

    NARCIS (Netherlands)

    Dalm, M.C.F.; Lamers, P.P.; Cuijten, S.M.R.; Tjeerdsma, A.M.; Grunsven, van W.M.J.; Tramper, J.; Martens, D.E.

    2007-01-01

    For the development of optimal perfusion processes, insight into the effect of feed and bleed rate on cell growth, productivity, and metabolism is essential. In the here presented study the effect of the feed and bleed rate on cell metabolism was investigated using metabolic flux analysis. Under all

  16. Measurement and relevance of maximum metabolic rate in fishes.

    Science.gov (United States)

    Norin, T; Clark, T D

    2016-01-01

    Maximum (aerobic) metabolic rate (MMR) is defined here as the maximum rate of oxygen consumption (M˙O2max ) that a fish can achieve at a given temperature under any ecologically relevant circumstance. Different techniques exist for eliciting MMR of fishes, of which swim-flume respirometry (critical swimming speed tests and burst-swimming protocols) and exhaustive chases are the most common. Available data suggest that the most suitable method for eliciting MMR varies with species and ecotype, and depends on the propensity of the fish to sustain swimming for extended durations as well as its capacity to simultaneously exercise and digest food. MMR varies substantially (>10 fold) between species with different lifestyles (i.e. interspecific variation), and to a lesser extent (aerobic scope, interest in measuring this trait has spread across disciplines in attempts to predict effects of climate change on fish populations. Here, various techniques used to elicit and measure MMR in different fish species with contrasting lifestyles are outlined and the relevance of MMR to the ecology, fitness and climate change resilience of fishes is discussed.

  17. Extreme strain rate and temperature dependence of the mechanical properties of nano silicon nitride thin layers in a basal plane under tension: a molecular dynamics study.

    Science.gov (United States)

    Lu, Xuefeng; Wang, Hongjie; Wei, Yin; Wen, Jiangbo; Niu, Min; Jia, Shuhai

    2014-08-01

    Molecular dynamics simulations are performed to clarify the extreme strain rate and temperature dependence of the mechanical behaviors of nano silicon nitride thin layers in a basal plane under tension. It is found that fracture stresses show almost no change with increasing strain rate. However, fracture strains decrease gradually due to the appearance of additional N(2c)-Si bond breaking defects in the deformation process. With increasing loading temperature, there is a noticeable drop in fracture stress and fracture strain. In the low temperature range, roughness phases can be observed owing to a combination of factors such as configuration evolution and energy change.

  18. Cellular Metabolic Rate Is Influenced by Life-History Traits in Tropical and Temperate Birds

    OpenAIRE

    Ana Gabriela Jimenez; James Van Brocklyn; Matthew Wortman; Williams, Joseph B.

    2014-01-01

    In general, tropical birds have a "slow pace of life," lower rates of whole-animal metabolism and higher survival rates, than temperate species. A fundamental challenge facing physiological ecologists is the understanding of how variation in life-history at the whole-organism level might be linked to cellular function. Because tropical birds have lower rates of whole-animal metabolism, we hypothesized that cells from tropical species would also have lower rates of cellular metabolism than cel...

  19. The determination of standard metabolic rate in fishes.

    Science.gov (United States)

    Chabot, D; Steffensen, J F; Farrell, A P

    2016-01-01

    This review and data analysis outline how fish biologists should most reliably estimate the minimal amount of oxygen needed by a fish to support its aerobic metabolic rate (termed standard metabolic rate; SMR). By reviewing key literature, it explains the theory, terminology and challenges underlying SMR measurements in fishes, which are almost always made using respirometry (which measures oxygen uptake, ṀO2 ). Then, the practical difficulties of measuring SMR when activity of the fish is not quantitatively evaluated are comprehensively explored using 85 examples of ṀO2 data from different fishes and one crustacean, an analysis that goes well beyond any previous attempt. The main objective was to compare eight methods to estimate SMR. The methods were: average of the lowest 10 values (low10) and average of the 10% lowest ṀO2 values, after removing the five lowest ones as outliers (low10%), mean of the lowest normal distribution (MLND) and quantiles that assign from 10 to 30% of the data below SMR (q0·1 , q0·15 , q0·2 , q0·25 and q0·3 ). The eight methods yielded significantly different SMR estimates, as expected. While the differences were small when the variability was low amongst the ṀO2 values, they were important (>20%) for several cases. The degree of agreement between the methods was related to the c.v. of the observations that were classified into the lowest normal distribution, the c.v. MLND (C.V.MLND ). When this indicator was low (≤5·4), it was advantageous to use the MLND, otherwise, one of the q0·2 or q0·25 should be used. The second objective was to assess if the data recorded during the initial recovery period in the respirometer should be included or excluded, and the recommendation is to exclude them. The final objective was to determine the minimal duration of experiments aiming to estimate SMR. The results show that 12 h is insufficient but 24 h is adequate. A list of basic recommendations for practitioners who use respirometry

  20. Scaling of standard metabolic rate in estuarine crocodiles Crocodylus porosus.

    Science.gov (United States)

    Seymour, Roger S; Gienger, C M; Brien, Matthew L; Tracy, Christopher R; Charlie Manolis, S; Webb, Grahame J W; Christian, Keith A

    2013-05-01

    Standard metabolic rate (SMR, ml O2 min(-1)) of captive Crocodylus porosus at 30 °C scales with body mass (kg) according to the equation, SMR = 1.01 M(0.829), in animals ranging in body mass of 3.3 orders of magnitude (0.19-389 kg). The exponent is significantly higher than 0.75, so does not conform to quarter-power scaling theory, but rather is likely an emergent property with no single explanation. SMR at 1 kg body mass is similar to the literature for C. porosus and for alligators. The high exponent is not related to feeding, growth, or obesity of captive animals. The log-transformed data appear slightly curved, mainly because SMR is somewhat low in many of the largest animals (291-389 kg). A 3-parameter model is scarcely different from the linear one, but reveals a declining exponent between 0.862 and 0.798. A non-linear model on arithmetic axes overestimates SMR in 70% of the smallest animals and does not satisfactorily represent the data.

  1. Assesment of Autonomic Function in Metabolic Syndrome using Combination Heart Rate Variability and Heart Rate Turbulence

    Directory of Open Access Journals (Sweden)

    Gülay Aydın

    2013-12-01

    Full Text Available INTRODUCTION: Metabolic syndrome (MetS is described as a group of various abnormal metabolic risk factors such as obesity, dyslipidemia, increased blood pressure, increased plasma glucose levels, prothrombotic condition and proinflammatory state. These parameters are related to decreased parasympathetic and increased sympathetic activity. We aimed to evaluate autonomic function using a combination with heart rate variability (HRV and heart rate turbulence (HRT in metabolic syndrome to compare non-metabolic syndrome(non-MetS. METHODS: We selected consecutive 50 patients with MetS and 50 patients with healthy non-MetS individuals. All patients underwent 24 hours holter monitoring to evaluate HRT and HRV parameters. RESULTS: Age of patients was not different in two groups. Mean age of MetS patients was 57,50±12,13 and 54,6±10,25 in non- MetS individuals. Sex of patients was non different in MetS compared to non-MetS (37 female and 13 male vs. 22 female, 28 male p<0,05 respectively. SDNN and RMSSD was lower in MetS compared to those without MetS (131,96±49,12 vs 179,59±85,83 p=0,03 and 78,64±35,22 vs 112,73±81,24 p=0,08 respectively. SDANN, pNN50,Mean RR, mean heart rate, count of ventricular premature complex(VPC were not different between two groups. Turbulence Slope(TS was not different in two groups. Turbulence Onset(TO was higher in MetS compared to non-MetS (2,01±15,29 and -6,21±13,5 p=0,005. DISCUSSION AND CONCLUSION: We showed that autonomic function in MetS was impaired using a combination with HRT and HRV. These patients should be followed closely for adverse cardiovascular outcome especially including cardiac arrhythmia.

  2. An explanation of the relationship between mass, metabolic rate and characteristic length for placental mammals

    Directory of Open Access Journals (Sweden)

    Charles C. Frasier

    2015-09-01

    Full Text Available The Mass, Metabolism and Length Explanation (MMLE was advanced in 1984 to explain the relationship between metabolic rate and body mass for birds and mammals. This paper reports on a modernized version of MMLE. MMLE deterministically computes the absolute value of Basal Metabolic Rate (BMR and body mass for individual animals. MMLE is thus distinct from other examinations of these topics that use species-averaged data to estimate the parameters in a statistically best fit power law relationship such as BMR = a(bodymassb. Beginning with the proposition that BMR is proportional to the number of mitochondria in an animal, two primary equations are derived that compute BMR and body mass as functions of an individual animal’s characteristic length and sturdiness factor. The characteristic length is a measureable skeletal length associated with an animal’s means of propulsion. The sturdiness factor expresses how sturdy or gracile an animal is. Eight other parameters occur in the equations that vary little among animals in the same phylogenetic group. The present paper modernizes MMLE by explicitly treating Froude and Strouhal dynamic similarity of mammals’ skeletal musculature, revising the treatment of BMR and using new data to estimate numerical values for the parameters that occur in the equations. A mass and length data set with 575 entries from the orders Rodentia, Chiroptera, Artiodactyla, Carnivora, Perissodactyla and Proboscidea is used. A BMR and mass data set with 436 entries from the orders Rodentia, Chiroptera, Artiodactyla and Carnivora is also used. With the estimated parameter values MMLE can calculate characteristic length and sturdiness factor values so that every BMR and mass datum from the BMR and mass data set can be computed exactly. Furthermore MMLE can calculate characteristic length and sturdiness factor values so that every body mass and length datum from the mass and length data set can be computed exactly. Whether or

  3. An explanation of the relationship between mass, metabolic rate and characteristic length for placental mammals

    Science.gov (United States)

    2015-01-01

    The Mass, Metabolism and Length Explanation (MMLE) was advanced in 1984 to explain the relationship between metabolic rate and body mass for birds and mammals. This paper reports on a modernized version of MMLE. MMLE deterministically computes the absolute value of Basal Metabolic Rate (BMR) and body mass for individual animals. MMLE is thus distinct from other examinations of these topics that use species-averaged data to estimate the parameters in a statistically best fit power law relationship such as BMR = a(bodymass)b. Beginning with the proposition that BMR is proportional to the number of mitochondria in an animal, two primary equations are derived that compute BMR and body mass as functions of an individual animal’s characteristic length and sturdiness factor. The characteristic length is a measureable skeletal length associated with an animal’s means of propulsion. The sturdiness factor expresses how sturdy or gracile an animal is. Eight other parameters occur in the equations that vary little among animals in the same phylogenetic group. The present paper modernizes MMLE by explicitly treating Froude and Strouhal dynamic similarity of mammals’ skeletal musculature, revising the treatment of BMR and using new data to estimate numerical values for the parameters that occur in the equations. A mass and length data set with 575 entries from the orders Rodentia, Chiroptera, Artiodactyla, Carnivora, Perissodactyla and Proboscidea is used. A BMR and mass data set with 436 entries from the orders Rodentia, Chiroptera, Artiodactyla and Carnivora is also used. With the estimated parameter values MMLE can calculate characteristic length and sturdiness factor values so that every BMR and mass datum from the BMR and mass data set can be computed exactly. Furthermore MMLE can calculate characteristic length and sturdiness factor values so that every body mass and length datum from the mass and length data set can be computed exactly. Whether or not MMLE can

  4. Brain-derived neurotrophic factor enhances the basal rate of protein synthesis by increasing active eukaryotic elongation factor 2 levels and promoting translation elongation in cortical neurons.

    Science.gov (United States)

    Takei, Nobuyuki; Kawamura, Mihoko; Ishizuka, Yuta; Kakiya, Naomasa; Inamura, Naoko; Namba, Hisaaki; Nawa, Hiroyuki

    2009-09-25

    The constitutive and activity-dependent components of protein synthesis are both critical for neural function. Although the mechanisms controlling extracellularly induced protein synthesis are becoming clear, less is understood about the molecular networks that regulate the basal translation rate. Here we describe the effects of chronic treatment with various neurotrophic factors and cytokines on the basal rate of protein synthesis in primary cortical neurons. Among the examined factors, brain-derived neurotrophic factor (BDNF) showed the strongest effect. The rate of protein synthesis increased in the cortical tissues of BDNF transgenic mice, whereas it decreased in BDNF knock-out mice. BDNF specifically increased the level of the active, unphosphorylated form of eukaryotic elongation factor 2 (eEF2). The levels of active eEF2 increased and decreased in BDNF transgenic and BDNF knock-out mice, respectively. BDNF decreased kinase activity and increased phosphatase activity against eEF2 in vitro. Additionally, BDNF shortened the ribosomal transit time, an index of translation elongation. In agreement with these results, overexpression of eEF2 enhanced protein synthesis. Taken together, our results demonstrate that the increased level of active eEF2 induced by chronic BDNF stimulation enhances translational elongation processes and increases the total rate of protein synthesis in neurons.

  5. The rate of metabolism in marine animals: environmental constraints, ecological demands and energetic opportunities

    OpenAIRE

    Seibel, Brad A.; Drazen, Jeffrey C.

    2007-01-01

    The rates of metabolism in animals vary tremendously throughout the biosphere. The origins of this variation are a matter of active debate with some scientists highlighting the importance of anatomical or environmental constraints, while others emphasize the diversity of ecological roles that organisms play and the associated energy demands. Here, we analyse metabolic rates in diverse marine taxa, with special emphasis on patterns of metabolic rate across a depth gradient, in an effort to und...

  6. Organ-specific rates of cellular respiration in developing sunflower seedlings and their bearing on metabolic scaling theory.

    Science.gov (United States)

    Kutschera, Ulrich; Niklas, Karl J

    2012-10-01

    Fifty years ago Max Kleiber described what has become known as the "mouse-to-elephant" curve, i.e., a log-log plot of basal metabolic rate versus body mass. From these data, "Kleiber's 3/4 law" was deduced, which states that metabolic activity scales as the three fourths-power of body mass. However, for reasons unknown so far, no such "universal scaling law" has been discovered for land plants (embryophytes). Here, we report that the metabolic rates of four different organs (cotyledons, cotyledonary hook, hypocotyl, and roots) of developing sunflower (Helianthus annuus L.) seedlings grown in darkness (skotomorphogenesis) and in white light (photomorphogenesis) differ by a factor of 2 to 5 and are largely independent of light treatment. The organ-specific respiration rate (oxygen uptake per minute per gram of fresh mass) of the apical hook, which is composed of cells with densely packaged cytoplasm, is much higher than that of the hypocotyl, an organ that contains vacuolated cells. Data for cell length, cell density, and DNA content reveal that (1) hook opening in white light is caused by a stimulation of cell elongation on the inside of the curved organ, (2) respiration, cell density and DNA content are much higher in the hook than in the stem, and (3) organ-specific respiration rates and the DNA contents of tissues are statistically correlated. We conclude that, due to the heterogeneity of the plant body caused by the vacuolization of the cells, Kleiber's law, which was deduced using mammals as a model system, cannot be applied to embryophytes. In plants, this rule may reflect scaling phenomena at the level of the metabolically active protoplasmic contents of the cells.

  7. Changes in basal rates and bolus calculator settings in insulin pumps during pregnancy in women with type 1 diabetes

    DEFF Research Database (Denmark)

    Mathiesen, Jonathan M; Secher, Anna L; Ringholm, Lene

    2014-01-01

    and HbA1c were recorded. Results were compared with 96 women with type 1 diabetes on multiple daily injection therapy. RESULTS: Throughout pregnancy, the carbohydrate-to-insulin ratio decreased at all three main meals. The most pronounced decrease was observed at breakfast, where the carbohydrate......-to-insulin ratio was reduced, from median 12 (range 4-20) in early pregnancy to 3 (2-10) g carbohydrate per unit insulin in late pregnancy. Basal insulin delivery increased by ∼50%, i.e. from 0.8 (0.5-2.2) to 1.2 (0.6-2.5) IU/h at 5 a.m. and from 1.0 (0.6-1.5) to 1.3 (0.2-2.3) IU/h at 5 p.m. during pregnancy. HbA1......c levels during pregnancy, the occurrence of severe hypoglycemia and pregnancy outcomes were similar in the two groups. CONCLUSIONS: In women with type 1 diabetes on insulin pump therapy with a bolus calculator, the carbohydrate-to-insulin ratio declined 4-fold from early to late pregnancy, whereas...

  8. Warming reduces metabolic rate in marine snails: adaptation to fluctuating high temperatures challenges the metabolic theory of ecology.

    Science.gov (United States)

    Marshall, David J; McQuaid, Christopher D

    2011-01-22

    The universal temperature-dependence model (UTD) of the metabolic theory of ecology (MTE) proposes that temperature controls mass-scaled, whole-animal resting metabolic rate according to the first principles of physics (Boltzmann kinetics). Controversy surrounds the model's implication of a mechanistic basis for metabolism that excludes the effects of adaptive regulation, and it is unclear how this would apply to organisms that live in fringe environments and typically show considerable metabolic adaptation. We explored thermal scaling of metabolism in a rocky-shore eulittoral-fringe snail (Echinolittorina malaccana) that experiences constrained energy gain and fluctuating high temperatures (between 25°C and approximately 50°C) during prolonged emersion (weeks). In contrast to the prediction of the UTD model, metabolic rate was often negatively related to temperature over a benign range (30-40°C), the relationship depending on (i) the temperature range, (ii) the degree of metabolic depression (related to the quiescent period), and (iii) whether snails were isolated within their shells. Apparent activation energies (E) varied between 0.05 and -0.43 eV, deviating excessively from the UTD's predicted range of between 0.6 and 0.7 eV. The lowering of metabolism when heated should improve energy conservation in a high-temperature environment and challenges both the theory's generality and its mechanistic basis.

  9. Effects of growth hormone transgenesis on metabolic rate, exercise performance and hypoxia tolerance in tilapia hybrids

    DEFF Research Database (Denmark)

    McKenzie, DJ; Martinez, R; Morales, A

    2003-01-01

    Swimming respirometry was employed to compare inactive metabolic rate (Rr), maximum metabolic rate (Rmax), resultant aerobic scope and maximum sustainable (critical) swimming speed (Ucrit), in growth hormone transgenic (GHT) and wild-type (W) tilapia Oreochromis sp. hybrids. Although the Rr of GHT...... tilapia also exhibited the same capacity to regulate oxygen uptake during progressive hypoxia, despite the fact that the GHT fish were defending a higher demand for O2. The results indicate that ectopic expression of GH raises metabolic rate in tilapia, but the fish compensate for this metabolic load...

  10. Hydration status after exercise affect resting metabolic rate and heart rate variability.

    Science.gov (United States)

    Castro-Sepulveda, Mauricio; Cerda-Kohler, Hugo; Pérez-Luco, Cristian; Monsalves, Matías; Andrade, David Cristobal; Zbinden-Foncea, Herman; Báez-San Martín, Eduardo; Ramírez-Campillo, Rodrigo

    2014-12-17

    Introducción: La variabilidad del ritmo cardiaco y la tasa metabólica basal se utilizan en evaluaciones de deportistas. La deshidratación por ejercicio puede conducir a pérdidas de hasta 5% de la masa corporal. En consecuencia, la deshidratación produce un profundo efecto sobre la homeostasis humana. Objetivos: Comparar los efectos de la deshidratación y la rehidratación después del ejercicio en la variabilidad del ritmo cardíaco y la tasa metabólica basal. Métodos: 14 atletas universitarios fueron divididos en un grupo de deshidratación (n=7) y un grupo de rehidratación (n=7), ambos fueron sometidos mediciones basales (Tiempo 1) de variabilidad del ritmo cardíaco y tasa metabólica basal. Después de las mediciones basales, ambos grupos se deshidrataron activamente (-3,4 ± 0,4% masa corporal). Posteriormente, el grupo de deshidratación descansado, mientras que el grupo de rehidratación recibió agua equivalente al 150% de la masa pérdida. Cuatro horas después de la deshidratación se re-evaluó la variabilidad del ritmo cardíaco y tasa metabólica (Tiempo 2). Resultados: El grupo de rehidratación (+13%) y el de deshidratación (+30%) lograron un aumento significativo en la tasa metabólica basal (p.

  11. Impact of a Metabolic Screening Bundle on Rates of Screening for Metabolic Syndrome in a Psychiatry Resident Outpatient Clinic

    Science.gov (United States)

    Wiechers, Ilse R.; Viron, Mark; Stoklosa, Joseph; Freudenreich, Oliver; Henderson, David C.; Weiss, Anthony

    2012-01-01

    Objective: Although it is widely acknowledged that second-generation antipsychotics are associated with cardiometabolic side effects, rates of metabolic screening have remained low. The authors created a quality-improvement (QI) intervention in an academic medical center outpatient psychiatry resident clinic with the aim of improving rates of…

  12. Metabolism correlates with variation in post-natal growth rate among songbirds at three latitudes

    Science.gov (United States)

    Ton, Riccardo; Martin, Thomas E.

    2016-01-01

    1. Variation in post-natal growth rates is substantial among organisms and especially strong among latitudes because tropical and south temperate species typically have slower growth than north temperate relatives. Metabolic rate is thought to be a critical mechanism underlying growth rates after accounting for allometric effects of body mass. However, comparative tests on a large spatial scale are lacking, and the importance of metabolism for growth rates remains unclear both within and particularly across latitudes.

  13. Effects of basal rate verification on CSⅡ dose adjustments in brittle diabetes%基础率验证在脆性糖尿病持续皮下胰岛素输注剂量调整中的作用

    Institute of Scientific and Technical Information of China (English)

    孙蔚; 陆志强; 花霞; 高鑫

    2013-01-01

    基础率验证是找寻并验证基础血糖代谢所需持续皮下胰岛素输注(CSⅡ)基础率的过程.本研究5例脆性糖尿病患者采用赖脯胰岛素CSⅡ治疗,CSⅡ剂量调整至血糖平稳,行基础率验证.结果显示,CSⅡ治疗后血糖整体水平和稳定性得到改善.基础率验证前后,CSⅡ总量无明显差异,基础率由总量的50%减至30%(P<0.05),餐时大剂量增至70%(P<0.05);午餐与晚餐时段基础率减少一半(P<0.05);午餐与晚餐大剂量增至1.5倍(P<0.05),需加用方波控制餐后血糖.结果提示,CSⅡ能平稳控制脆性糖尿病血糖,不依赖基础率验证.然而实施验证能更好地确定适合基础血糖代谢的基础率,进而有助于确定与饮食相关的餐时大剂量.%Basal rate verification is the process to find and verify the basal rate of continuous subcutaneous insulin infusion (CSⅡ) required for basal glucose metabolism.In the present study,five cases of brittle diabetes were treated by CSⅡ with Insulin Lispro.After doses were adjusted to reach steady blood glucose levels,basal rate verifying tests were carried out.The results showed that the overall level and stability of blood glucose were improved markedly after CSⅡ.Before and after the verification of the basal rate,there was no significant difference in CSⅡ total doses.Basal rates decreased from 50% of total to 30% (P<0.05),and boluses increased to 70% (P<0.05).The basal rates during lunch and supper time were reduced by half (P<0.05),the boluses of lunch and supper were increased 1.5 times (P<0.05),and square waves were needed to control postprandial blood glucose.These results suggest that the CSⅡ could smoothly control blood glucose level in brittle diabetes without basal rate verification.However,the implementation of the verification could better determine the basal rates for basal glucose metabolism,and thus help to identify diet-related boluses.

  14. Peripheral reduction of FGFR4 with antisense oligonucleotides increases metabolic rate and lowers adiposity in diet-induced obese mice.

    Directory of Open Access Journals (Sweden)

    Xing Xian Yu

    Full Text Available Obesity is a primary risk factor for multiple metabolic disorders. Many drugs for the treatment of obesity, which mainly act through CNS as appetite suppressants, have failed during development or been removed from the market due to unacceptable adverse effects. Thus, there are very few efficacious drugs available and remains a great unmet medical need for anti-obesity drugs that increase energy expenditure by acting on peripheral tissues without severe side effects. Here, we report a novel approach involving antisense inhibition of fibroblast growth factor receptor 4 (FGFR4 in peripheral tissues. Treatment of diet-induce obese (DIO mice with FGFR4 antisense oligonucleotides (ASO specifically reduced liver FGFR4 expression that not only resulted in decrease in body weight (BW and adiposity in free-feeding conditions, but also lowered BW and adiposity under caloric restriction. In addition, combination treatment with FGFR4 ASO and rimonabant showed additive reduction in BW and adiposity. FGFR4 ASO treatment increased basal metabolic rate during free-feeding conditions and, more importantly, prevented adaptive decreases of metabolic rate induced by caloric restriction. The treatment increased fatty acid oxidation while decreased lipogenesis in both liver and fat. Mechanistic studies indicated that anti-obesity effect of FGFR4 ASO was mediated at least in part through an induction of plasma FGF15 level resulted from reduction of hepatic FGFR4 expression. The anti-obesity effect was accompanied by improvement in plasma glycemia, whole body insulin sensitivity, plasma lipid levels and liver steatosis. Therefore, FGFR4 could be a potential novel target and antisense reduction of hepatic FGFR4 expression could be an efficacious therapy as an adjunct to diet restriction or to an appetite suppressant for the treatment of obesity and related metabolic disorders.

  15. Peripheral reduction of FGFR4 with antisense oligonucleotides increases metabolic rate and lowers adiposity in diet-induced obese mice.

    Science.gov (United States)

    Yu, Xing Xian; Watts, Lynnetta M; Manchem, Vara Prasad; Chakravarty, Kaushik; Monia, Brett P; McCaleb, Michael L; Bhanot, Sanjay

    2013-01-01

    Obesity is a primary risk factor for multiple metabolic disorders. Many drugs for the treatment of obesity, which mainly act through CNS as appetite suppressants, have failed during development or been removed from the market due to unacceptable adverse effects. Thus, there are very few efficacious drugs available and remains a great unmet medical need for anti-obesity drugs that increase energy expenditure by acting on peripheral tissues without severe side effects. Here, we report a novel approach involving antisense inhibition of fibroblast growth factor receptor 4 (FGFR4) in peripheral tissues. Treatment of diet-induce obese (DIO) mice with FGFR4 antisense oligonucleotides (ASO) specifically reduced liver FGFR4 expression that not only resulted in decrease in body weight (BW) and adiposity in free-feeding conditions, but also lowered BW and adiposity under caloric restriction. In addition, combination treatment with FGFR4 ASO and rimonabant showed additive reduction in BW and adiposity. FGFR4 ASO treatment increased basal metabolic rate during free-feeding conditions and, more importantly, prevented adaptive decreases of metabolic rate induced by caloric restriction. The treatment increased fatty acid oxidation while decreased lipogenesis in both liver and fat. Mechanistic studies indicated that anti-obesity effect of FGFR4 ASO was mediated at least in part through an induction of plasma FGF15 level resulted from reduction of hepatic FGFR4 expression. The anti-obesity effect was accompanied by improvement in plasma glycemia, whole body insulin sensitivity, plasma lipid levels and liver steatosis. Therefore, FGFR4 could be a potential novel target and antisense reduction of hepatic FGFR4 expression could be an efficacious therapy as an adjunct to diet restriction or to an appetite suppressant for the treatment of obesity and related metabolic disorders.

  16. Prediction of microbial growth rate versus biomass yield by a metabolic network with kinetic parameters.

    Science.gov (United States)

    Adadi, Roi; Volkmer, Benjamin; Milo, Ron; Heinemann, Matthias; Shlomi, Tomer

    2012-01-01

    Identifying the factors that determine microbial growth rate under various environmental and genetic conditions is a major challenge of systems biology. While current genome-scale metabolic modeling approaches enable us to successfully predict a variety of metabolic phenotypes, including maximal biomass yield, the prediction of actual growth rate is a long standing goal. This gap stems from strictly relying on data regarding reaction stoichiometry and directionality, without accounting for enzyme kinetic considerations. Here we present a novel metabolic network-based approach, MetabOlic Modeling with ENzyme kineTics (MOMENT), which predicts metabolic flux rate and growth rate by utilizing prior data on enzyme turnover rates and enzyme molecular weights, without requiring measurements of nutrient uptake rates. The method is based on an identified design principle of metabolism in which enzymes catalyzing high flux reactions across different media tend to be more efficient in terms of having higher turnover numbers. Extending upon previous attempts to utilize kinetic data in genome-scale metabolic modeling, our approach takes into account the requirement for specific enzyme concentrations for catalyzing predicted metabolic flux rates, considering isozymes, protein complexes, and multi-functional enzymes. MOMENT is shown to significantly improve the prediction accuracy of various metabolic phenotypes in E. coli, including intracellular flux rates and changes in gene expression levels under different growth rates. Most importantly, MOMENT is shown to predict growth rates of E. coli under a diverse set of media that are correlated with experimental measurements, markedly improving upon existing state-of-the art stoichiometric modeling approaches. These results support the view that a physiological bound on cellular enzyme concentrations is a key factor that determines microbial growth rate.

  17. Basal Cell Carcinoma

    Science.gov (United States)

    ... Kids’ zone Video library Find a dermatologist Basal cell carcinoma Overview Basal cell carcinoma: This skin cancer ... that has received years of sun exposure. Basal cell carcinoma: Overview Basal cell carcinoma (BCC) is the ...

  18. Thermal sensation and comfort with transient metabolic rates

    DEFF Research Database (Denmark)

    Goto, Tomonobu; Toftum, Jørn; Dear, R. d.;

    2002-01-01

    environment was held constant at a temperature corresponding to PMV=0 at sedentary activity. Even low activity changes of short duration (1 min at 20% relative work load) affected thermal perceptions. However, after circa 15 min of constant activity, subjective thermal responses approximated the steady......This study investigated the effect on thermal perceptions and preferences of controlled metabolic excursions of various intensities (20%, 40%, 60% relative work load) and durations (3-30 min) imposed on subjects that alternated between sedentary activity and exercise on a treadmill. The thermal...

  19. Can We Rely on Predicted Basal Metabolic Rate in Patients With Intestinal Failure on Home Parenteral Nutrition?

    DEFF Research Database (Denmark)

    Andersen, Anders Skallerup; Pedersen, Louis Nygaard; Olesen, Søren Schou

    2017-01-01

    evaluated the accuracy of predicted BMR in clinically stable patients with IF dependent on home parenteral nutrition (HPN). METHODS: In total, 103 patients with IF were included. We used indirect calorimetry for assessment of BMR and calculated predicted BMR using different equations based on anthropometric...

  20. The absorption and metabolism of a single L-menthol oral versus skin administration: Effects on thermogenesis and metabolic rate.

    Science.gov (United States)

    Valente, Angelica; Carrillo, Andres E; Tzatzarakis, Manolis N; Vakonaki, Elena; Tsatsakis, Aristidis M; Kenny, Glen P; Koutedakis, Yiannis; Jamurtas, Athanasios Z; Flouris, Andreas D

    2015-12-01

    We investigated the absorption and metabolism pharmacokinetics of a single L-menthol oral versus skin administration and the effects on human thermogenesis and metabolic rate. Twenty healthy adults were randomly distributed into oral (capsule) and skin (gel) groups and treated with 10 mg kg(-1) L-menthol (ORALMENT; SKINMENT) or control (lactose capsule: ORALCON; water application: SKINCON) in a random order on two different days. Levels of serum L-menthol increased similarly in ORALMENT and SKINMENT (p > 0.05). L-menthol glucuronidation was greater in ORALMENT than SKINMENT (p  0.05). Participants reported no cold, shivering, discomfort, stress or skin irritation. We conclude that a single L-menthol skin administration increased thermogenesis and metabolic rate in humans. These effects are minor following L-menthol oral administration probably due to faster glucuronidation and greater blood menthol glucuronide levels.

  1. Prediction of Microbial Growth Rate versus Biomass Yield by a Metabolic Network with Kinetic Parameters

    NARCIS (Netherlands)

    Adadi, Roi; Volkmer, Benjamin; Milo, Ron; Heinemann, Matthias; Shlomi, Tomer

    2012-01-01

    Identifying the factors that determine microbial growth rate under various environmental and genetic conditions is a major challenge of systems biology. While current genome-scale metabolic modeling approaches enable us to successfully predict a variety of metabolic phenotypes, including maximal bio

  2. [Estimation of heritability and repeatability of resting metabolic rate in birds, with free-living pied flycatchers Ficedula hypoleuca (Aves: Passeriformes) as an example].

    Science.gov (United States)

    Bushuev, A V; Kerimov, A B; Ivankina, E V

    2010-01-01

    Estimates of a trait heritability and repeatability can get at an idea of its usefulness for being an individual characteristic and its ability to change under selection pressure. Heritability and repeatability of energetic parameters still poorly studied in birds. The most important physiological characteristic of homoiotherms is resting metabolic rate (RMR), which, in the absence of productive processes, does not exceed basal metabolic rate (BMR). We estimated BMR repeatability in free-living pied flycatchers in Moscow Region (55 degrees 44' N, 36 degrees 51' E; 1992-2008) and Tomsk (56 degrees 20' N, 84 degrees 56' E; 2008-2009) populations over intervals from 40 days to 3 years. In Moscow Region population, BMR repeatability amounted to tau = 0.34 +/- 0.10 (n=80) if measured over 1 year interval, tau = 0.60 +/- 0.15 (n=19) if measured over 2 years interval, and tau = 0.85 +/- 0.13 (n=6) if measured over 3 years interval providing that consecutive BMR measurements were done in the same period of reproductive season. In Tomsk population, BMR repeatability, measured over 1 year interval, amounted to tau = 0.49 +/- 0.11 (n=50). Repeatability is a measure of a trait constancy and sets the upper limit of its heritability. To estimate RMR heritability, cross-fostering experiments have been conducted in 2003-2005 with flycatchers of Moscow Region population. RMR of chicks positively correlated with BMR of their biological fathers, whereas such correlation in metabolic rates between chicks and their foster fathers was absent. The RMR heritability estimate turned out to be h2 = 0.43 +/- 0.17 (n=210). The obtained estimates of heritability and repeatability of fundamental energetic traits are rather high for physiological features. This suggests the existence of a potential for direct selection on BMR and evolutionary stable diversity of avian populations with regard to basal metabolic rate.

  3. Novel approaches to the calculation and comparison of thermoregulatory parameters: Non-linear regression of metabolic rate and evaporative water loss in Australian rodents.

    Science.gov (United States)

    Tomlinson, Sean

    2016-04-01

    The calculation and comparison of physiological characteristics of thermoregulation has provided insight into patterns of ecology and evolution for over half a century. Thermoregulation has typically been explored using linear techniques; I explore the application of non-linear scaling to more accurately calculate and compare characteristics and thresholds of thermoregulation, including the basal metabolic rate (BMR), peak metabolic rate (PMR) and the lower (Tlc) and upper (Tuc) critical limits to the thermo-neutral zone (TNZ) for Australian rodents. An exponentially-modified logistic function accurately characterised the response of metabolic rate to ambient temperature, while evaporative water loss was accurately characterised by a Michaelis-Menten function. When these functions were used to resolve unique parameters for the nine species studied here, the estimates of BMR and TNZ were consistent with the previously published estimates. The approach resolved differences in rates of metabolism and water loss between subfamilies of Australian rodents that haven't been quantified before. I suggest that non-linear scaling is not only more effective than the established segmented linear techniques, but also is more objective. This approach may allow broader and more flexible comparison of characteristics of thermoregulation, but it needs testing with a broader array of taxa than those used here.

  4. Hybrid Dysfunction Expressed as Elevated Metabolic Rate in Male Ficedula Flycatchers

    Science.gov (United States)

    McFarlane, S. Eryn; Sirkiä, Päivi M.; Ålund, Murielle; Qvarnström, Anna

    2016-01-01

    Studies of ecological speciation are often biased towards extrinsic sources of selection against hybrids, resulting from intermediate hybrid morphology, but the knowledge of how genetic incompatibilities accumulate over time under natural conditions is limited. Here we focus on a physiological trait, metabolic rate, which is central to life history strategies and thermoregulation but is also likely to be sensitive to mismatched mitonuclear interactions. We measured the resting metabolic rate of male collared, and pied flycatchers as well as of naturally occurring F1 hybrid males, in a recent hybrid zone. We found that hybrid males had a higher rather than intermediate metabolic rate, which is indicative of hybrid physiological dysfunction. Fitness costs associated with elevated metabolic rate are typically environmentally dependent and exaggerated under harsh conditions. By focusing on male hybrid dysfunction in an eco-physiological trait, our results contribute to the general understanding of how combined extrinsic and intrinsic sources of hybrid dysfunction build up under natural conditions. PMID:27583553

  5. Dietary intakes, resting metabolic rates, and body composition in benign and malignant gastrointestinal disease.

    OpenAIRE

    Burke, M.; Bryson, E I; Kark, A E.

    1980-01-01

    Dietary protein and energy intakes were assessed in 42 patients with cancer and 24 with benign conditions of the gastrointestinal tract. The relations of dietary intake to body composition was examined. Resulting metabolic rate was measured in 51 patients. No significant differences in dietary intake or metabolic rate were found between patients with cancer and those with benign disease. There were significant positive correlations between protein and energy intakes and the ratio of total bod...

  6. Treatment of human muscle cells with popular dietary supplements increase mitochondrial function and metabolic rate

    Directory of Open Access Journals (Sweden)

    Vaughan Roger A

    2012-11-01

    Full Text Available Abstract Background Obesity is a common pathology with increasing incidence, and is associated with increased mortality and healthcare costs. Several treatment options for obesity are currently available ranging from behavioral modifications to pharmaceutical agents. Many popular dietary supplements claim to enhance weight loss by acting as metabolic stimulators, however direct tests of their effect on metabolism have not been performed. Purpose This work identified the effects popular dietary supplements on metabolic rate and mitochondrial biosynthesis in human skeletal muscle cells. Methods Human rhabdomyosarcoma cells were treated with popular dietary supplements at varied doses for 24 hours. Peroxisome proliferator-activated receptor coactivator 1 alpha (PGC-1α, an important stimulator of mitochondrial biosynthesis, was quantified using quantitative reverse transcriptase polymerase chain reaction (qRT-PCR. Mitochondrial content was measured using flow cytometry confirmed with confocal microscopy. Glycolytic metabolism was quantified by measuring extracellular acidification rate (ECAR and oxidative metabolism was quantified by measuring oxygen consumption rate (OCR. Total relative metabolism was quantified using WST-1 end point assay. Results Treatment of human rhabdomyosarcoma cells with dietary supplements OxyElite Pro (OEP or Cellucore HD (CHD induced PGC-1α leading to significantly increased mitochondrial content. Glycolytic and oxidative capacities were also significantly increased following treatment with OEP or CHD. Conclusion This is the first work to identify metabolic adaptations in muscle cells following treatment with popular dietary supplements including enhanced mitochondrial biosynthesis, and glycolytic, oxidative and total metabolism.

  7. Diagnosis of In Situ Metabolic State and Rates of Microbial Metabolism During In Situ Uranium Bioremediation with Molecular Techniques

    Energy Technology Data Exchange (ETDEWEB)

    Lovley, Derek R. [University of Massachusetts, Amherst

    2012-11-28

    The goal of these projects was to develop molecule tools to tract the metabolic activity and physiological status of microorganisms during in situ uranium bioremediation. Such information is important in able to design improved bioremediation strategies. As summarized below, the research was highly successful with new strategies developed for estimating in situ rates of metabolism and diagnosing the physiological status of the predominant subsurface microorganisms. This is a first not only for groundwater bioremediation studies, but also for subsurface microbiology in general. The tools and approaches developed in these studies should be applicable to the study of microbial communities in a diversity of soils and sediments.

  8. Is there a relationship between insect metabolic rate and mortality of mealworms Tenebrio molitor L. after insecticide exposure?

    OpenAIRE

    Justyna MALISZEWSKA; TĘGOWSKA, Eugenia

    2016-01-01

    Pesticides are known to affect insects metabolic rate and CO2 release patterns. In the presented paper metabolic rate and mortality of mealworms Tenebrio molitor L. exposed to four different insecticides was evaluated, to find out whether there is a relationship between mealworms sensitivity to pesticides and their metabolic rate. Tenebrio molitor mortality was determined after intoxication with pyrethroid, oxadiazine, neonicotinoid and organophosphate. Metabolic rate before and after intoxic...

  9. Preferred Barefoot Step Frequency is Influenced by Factors Beyond Minimizing Metabolic Rate

    Science.gov (United States)

    Yandell, Matthew B.; Zelik, Karl E.

    2016-03-01

    Humans tend to increase their step frequency in barefoot walking, as compared to shod walking at the same speed. Based on prior studies and the energy minimization hypothesis we predicted that people make this adjustment to minimize metabolic cost. We performed an experiment quantifying barefoot walking metabolic rate at different step frequencies, specifically comparing preferred barefoot to preferred shod step frequency. We found that subjects increased their preferred frequency when walking barefoot at 1.4 m/s (~123 vs. ~117 steps/min shod, P = 2e-5). However, average barefoot walking metabolic rates at the preferred barefoot and shod step frequencies were not significantly different (P = 0.40). Instead, we observed subject-specific trends: five subjects consistently reduced (‑8% average), and three subjects consistently increased (+10% average) their metabolic rate at preferred barefoot vs. preferred shod frequency. Thus, it does not appear that people ubiquitously select a barefoot step frequency that minimizes metabolic rate. We concluded that preferred barefoot step frequency is influenced by factors beyond minimizing metabolic rate, such as shoe properties and/or perceived comfort. Our results highlight the subject-specific nature of locomotor adaptations and how averaging data across subjects may obscure meaningful trends. Alternative experimental designs may be needed to better understand individual adaptations.

  10. Transitions in insect respiratory patterns are controlled by changes in metabolic rate.

    Science.gov (United States)

    Contreras, H L; Bradley, T J

    2010-05-01

    We examined the respiratory patterns of Rhodnius prolixus and Gromphadorhina portentosa as metabolic rates varied with temperature to determine whether insects transition from discontinuous (DGC), cyclical and continuous respiration as a response to increasing aerobic demand. Using flow through respirometry we: (1) determined the effects of temperature on metabolic rate; (2) objectively defined periods of spiracular closure; (3) observed whether there was a correlation between metabolic rate and length of spiracular closure. At low temperatures both species exhibit lengthy periods of spiracular closure reflecting a discontinuous respiratory pattern. As metabolic rate increased, periods of spiracular closure decreased and insects displayed a more cyclical pattern of respiration. As metabolic rates increased even further under the highest experimental temperatures, periods of spiracular closure decreased even more and a continuous respiratory pattern was employed by both species. Our results suggest that the three described respiratory patterns in insects are not distinct but are instead a continuum of respiratory responses driven by the metabolic demand experienced by the insect.

  11. Activity of the basal ganglia in Parkinson`s disease estimated by PET

    Energy Technology Data Exchange (ETDEWEB)

    Ohye, Chihiro [Gunma Univ., Maebashi (Japan). School of Medicine

    1995-04-01

    Positron emission tomographic (PET) studies on the local cerebral blood flow, oxygen metabolic rate, glucose metabolic rate in the basal ganglia of Parkinson`s disease are reviewed. PET has demonstrated that blood flow was decreased in the cerebral cortex, especially the frontal region, of Parkinson`s disease and that specific change in blood flow or metabolic rate in the basal ganglia was detected only in patients with hemi-parkinsonism. In authors` study on PET using {sup 18}FDG in patients with tremor type and rigid type Parkinson`s disease, changes in blood flow and metabolic rate were minimal at the basal ganglia level in tremor type patients, but cortical blood flow was decreased and metabolic rate was more elevated in the basal ganglia in rigid type patients. These findings were correlated with depth micro-recordings obtained by stereotactic pallidotomy. PET studies have also revealed that activity in the nerve terminal was decreased with decreasing dopamine and that dopamine (mainly D{sub 2}) activity was remarkably increased. PET studies with specific tracers are promising in providing more accurate information about functional state of living human brain with minimal invasion to patients. (N.K.).

  12. Daily patterns of metabolic rate among New Zealand lizards (Reptilia: Lacertilia: Diplodactylidae and Scincidae).

    Science.gov (United States)

    Hare, Kelly M; Pledger, Shirley; Thompson, Michael B; Miller, John H; Daugherty, Charles H

    2006-01-01

    In addition to the effects of temperature fluctuations on metabolic rate, entrained endogenous rhythms in metabolism, which are independent of temperature fluctuations, may be important in overall energy metabolism in ectotherms. Daily entrained endogenous rhythms may serve as energy-conserving mechanisms during an animal's active or inactive phase. However, because nocturnal lizards often take advantage of thermal opportunities during the photophase (light), their daily metabolic rhythms may be less pronounced than those of diurnal species. We measured the rate of oxygen consumption (VO(2)) as an index of metabolic rate of eight temperate lizard species (four nocturnal, three diurnal, and one crepuscular/diurnal; n = 7-14) over 24 h at 13 degrees C and in constant darkness to test whether daily patterns (including amplitude, magnitude, and time of peak VO(2)) of metabolic rate in lizards differ with activity period. We also tested for phylogenetic differences in metabolic rate between skinks and geckos. Three daily patterns were evident: 24-h cycle, 12-h cycle, or no daily cycle. The skink Cyclodina aenea has a 12-h crepuscular pattern of oxygen consumption. In four other species, VO(2) increased with, or in anticipation of, the active part of the day, but three species had rhythms offset from their active phase. Although not correlated with activity period or phylogeny, amplitude of VO(2) may be correlated with whether a species is temperate or tropical. In conclusion, the metabolic rate of many species does not always correlate with the recorded activity period. The dichotomy of ecology and physiology may be clarified by more in-depth studies of species behaviors and activity periods.

  13. Running and Metabolic Demands of Elite Rugby Union Assessed Using Traditional, Metabolic Power, and Heart Rate Monitoring Methods

    Science.gov (United States)

    Dubois, Romain; Paillard, Thierry; Lyons, Mark; McGrath, David; Maurelli, Olivier; Prioux, Jacques

    2017-01-01

    The aims of this study were (1) to analyze elite rugby union game demands using 3 different approaches: traditional, metabolic and heart rate-based methods (2) to explore the relationship between these methods and (3) to explore positional differences between the backs and forwards players. Time motion analysis and game demands of fourteen professional players (24.1 ± 3.4 y), over 5 European challenge cup games, were analyzed. Thresholds of 14.4 km·h-1, 20 W.kg-1 and 85% of maximal heart rate (HRmax) were set for high-intensity efforts across the three methods. The mean % of HRmax was 80.6 ± 4.3 % while 42.2 ± 16.5% of game time was spent above 85% of HRmax with no significant differences between the forwards and the backs. Our findings also show that the backs cover greater distances at high-speed than forwards (% difference: +35.2 ± 6.6%; prunning distances of 24.8 ± 17.1% for the backs, and 53.4 ± 16.0% for the forwards with a significant difference (+29.6 ± 6.0% for the forwards; prunning distance (assessed using the traditional approach) and the high-metabolic power distance. The HR monitoring methods demonstrate clearly the high physiological demands of professional rugby games. The traditional and the metabolic-power approaches shows a close correlation concerning their relative values, nevertheless the difference in absolute values especially for the high-intensity thresholds demonstrates that the metabolic power approach may represent an interesting alternative to the traditional approaches used in evaluating the high-intensity running efforts required in rugby union games. Key points Elite/professional rugby union players Heart rate monitoring during official games Metabolic power approach PMID:28344455

  14. Temperature dependence of metabolic rates for microbial growth, maintenance, and survival.

    Science.gov (United States)

    Price, P Buford; Sowers, Todd

    2004-03-30

    Our work was motivated by discoveries of prokaryotic communities that survive with little nutrient in ice and permafrost, with implications for past or present microbial life in Martian permafrost and Europan ice. We compared the temperature dependence of metabolic rates of microbial communities in permafrost, ice, snow, clouds, oceans, lakes, marine and freshwater sediments, and subsurface aquifer sediments. Metabolic rates per cell fall into three groupings: (i) a rate, microg(T), for growth, measured in the laboratory at in situ temperatures with minimal disturbance of the medium; (ii) a rate, microm(T), sufficient for maintenance of functions but for a nutrient level too low for growth; and (iii) a rate, micros(T), for survival of communities imprisoned in deep glacial ice, subsurface sediment, or ocean sediment, in which they can repair macromolecular damage but are probably largely dormant. The three groups have metabolic rates consistent with a single activation energy of approximately 110 kJ and that scale as microg(T):microm(T):micros(T) approximately 10(6):10(3):1. There is no evidence of a minimum temperature for metabolism. The rate at -40 degrees C in ice corresponds to approximately 10 turnovers of cellular carbon per billion years. Microbes in ice and permafrost have metabolic rates similar to those in water, soil, and sediment at the same temperature. This finding supports the view that, far below the freezing point, liquid water inside ice and permafrost is available for metabolism. The rate micros(T) for repairing molecular damage by means of DNA-repair enzymes and protein-repair enzymes such as methyltransferase is found to be comparable to the rate of spontaneous molecular damage.

  15. Effects of starvation and molting on the metabolic rate of the bed bug (Cimex lectularius L.).

    Science.gov (United States)

    DeVries, Zachary C; Kells, Stephen A; Appel, Arthur G

    2015-01-01

    The bed bug (Cimex lectularius L.) is a common hematophagous pest in the urban environment and is capable of surviving extended periods of starvation. However, the relationship between starvation and metabolism in bed bugs is not well understood. To better understand this relationship, we measured the metabolism of all life stages for >900 h after feeding (starvation) using closed-system respirometry. Measurements were made around molting for the immature life stages, which occurs only after a blood meal. In addition, both mated and unmated adults were measured. Starvation and molting had significant effects on the metabolism of the bed bug. Mass-specific metabolic rate (V(O2); mL g(-1) h(-1)) declined in a curvilinear fashion with the period of starvation for adults and with the postmolting period for immature bed bugs (used to standardize all immature life stages). A standard curve was developed to depict the generalized pattern of metabolic decline observed in all life stages that molted. Individual metabolic comparisons among life stages that molted revealed some differences in metabolic rate between unmated males and females. In addition, the mass scaling coefficient was found to decline with starvation time (postmolting time) for all life stages that molted. In most life stages, the ratio of V(CO2) to V(O2) (respiratory exchange ratio) declined over time, indicating a change in metabolic substrate with starvation. Finally, daily percent loss in body mass declined in a pattern similar to that of V(O2). The observed patterns in metabolic decline are evaluated in relation to the life history of bed bugs. In addition, the evolutionary development of these patterns is discussed. The metabolic pattern after feeding was also found to share several similarities with that of other ectothermic species.

  16. Low metabolic rates in salamanders are correlated with weak selective constraints on mitochondrial genes.

    Science.gov (United States)

    Chong, Rebecca A; Mueller, Rachel Lockridge

    2013-03-01

    Mitochondria are the site for the citric acid cycle and oxidative phosphorylation (OXPHOS), the final steps of ATP synthesis via cellular respiration. Each mitochondrion contains its own genome; in vertebrates, this is a small, circular DNA molecule that encodes 13 subunits of the multiprotein OXPHOS electron transport complexes. Vertebrate lineages vary dramatically in metabolic rates; thus, functional constraints on mitochondrial-encoded proteins likely differ, potentially impacting mitochondrial genome evolution. Here, we examine mitochondrial genome evolution in salamanders, which have the lowest metabolic requirements among tetrapods. We show that salamanders experience weaker purifying selection on protein-coding sequences than do frogs, a comparable amphibian clade with higher metabolic rates. In contrast, we find no evidence for weaker selection against mitochondrial genome expansion in salamanders. Together, these results suggest that different aspects of mitochondrial genome evolution (i.e., nucleotide substitution, accumulation of noncoding sequences) are differently affected by metabolic variation across tetrapod lineages.

  17. The effects of hydraulics, geomorphology, and storm events on metabolism rates in an agricultural river

    Science.gov (United States)

    O'Connor, B. L.; Harvey, J. W.; McPhillips, L. E.

    2009-12-01

    Physical factors such as discharge, geomorphology, and sediment transport strongly influence metabolism rates in agricultural rivers with sparse tree canopies where sunlight is not limiting. These physical processes establish a mosaic of sediment habitats of varying particle sizes, permeabilities, and biological communities that control primary production and respiration rates. In this study, we examined the combined factors of hydraulic conditions, sediment texture, and hyporheic exchange on the spatial and temporal variability of metabolism rates in an agricultural river located in central Iowa. Hydraulic conditions were quantified using field velocity measurements and two-dimensional hydraulic modeling. Sediment texture was assessed using a grid-based survey identifying dominant particle size classes, as well as aerial coverage of green algae and fine benthic organic material. Hyporheic exchange potential was quantified using an effective diffusion scaling relationship based on sediment and flow conditions. Patch-scale metabolism rates varied spatially according to patterns in hydraulic and sediment characteristics, but were of the same order of magnitude as reach-scale gross primary productivity and community respiration measurements. Two discharge-related storm perturbation regimes to the reach-scale metabolism rates were identified using diurnal dissolved oxygen data measured at the study reach over three years. Rainfall events of days as a result of increased turbidity, whereas rainfall events of > 3 cm disrupted metabolism rates for several days to weeks due to bed mobilization and the restructuring of the sediment habitats. A combination of hydraulic modeling, habitat mapping, and reach-scale metabolism measurements were used to produce a two-dimensional analysis of a turbidity-related disturbance event that occurred in late fall 2007. Results from this study suggest that physical processes establish, destroy, and restructure hydraulic and sediment

  18. Some metabolic effects of overeating in man.

    Science.gov (United States)

    Welle, S L; Seaton, T B; Campbell, R G

    1986-12-01

    Metabolic responses to 20 days of overeating were examined in five healthy volunteers. Overfeeding caused a variable increase (1-18%) in basal metabolic rate but no change in metabolic rate during light exercise. Postprandial resting metabolic rate was 8-40% higher (mean 18%) during overeating. The increase in oxygen consumption during a norepinephrine infusion was the same before (20 +/- 2%) and after (17 +/- 3%) overfeeding. Overfeeding elevated basal insulin concentrations in all subjects and increased the insulin response to intravenous glucose in four of five subjects. Overfeeding did not significantly alter mean serum T3 concentrations or erythrocyte 86Rb uptake (an index of Na+,K+-ATPase activity). These data do not confirm reports that overfeeding increases metabolic rate more during exercise than during rest. They also suggest that the increase in resting metabolic rate during overfeeding is not caused by increased responsiveness to norepinephrine or increased serum T3 concentrations.

  19. RELATION OF BODY WEIGHT AND FOOD CONSUMPTION TO METABOLIC RATE OF JUVENILE JAPANESE SEA BASS,LATEOLABRAX JAPONICUS

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    The metabolic rate of Japanese sea bass, Lateolabrax japonicus (C & V), was estimated in laboratory at temperature 25.2±0.5℃. The fresh weight of the fish was 4.64-52.28 g (average of 17.81±0.33 g). The routine metabolism was related to body weight by the exponential equation: Rr=14.966W0.74 (r=0.934). The rate of feeding metabolism increased linearly with food consumption. Feeding metabolic rate was 1.8-2.4 times the routine metabolic rate.

  20. Metabolic rates and thermoregulatory characteristics of Akodon azarae (Rodentia: Sigmodontinae Tasas metabólicas y características termorregulatorias de Akodon azarae (Rodentia: Sigmodontinae

    Directory of Open Access Journals (Sweden)

    C. DANIEL ANTINUCHI

    2000-03-01

    Full Text Available In this work, we evaluated the energetic status, activity daily metabolic rate, thermoregulatory capacity and the existence of torpor in Akodon azarae (Fisher 1829. Basal metabolic rate (BMR was similar to the expected value from Kleiber´s, and also according to the BMR of phylogenetically related species. No statistical difference in BMR between sexes was detected. For both males and females, activity daily metabolic rate was 235 % of BMR. Body temperature was not statistically different, neither at different ambient temperatures nor between sexes. In the thermoneutral zone, body temperature was 36.1 ± 1.5 °C. Thermal conductance was lower than the expected for mammals whereas thermoregulatory capacity was 136 % of the expected. Akodon azarae did not show evidence of torporEn este trabajo fueron evaluadas, para Akodon azarae (Fisher 1829, la tasa metabólica basal (BMR y de actividad diaria así como la capacidad termorregulatoria y la posible existencia de torpor. La BMR no presentó diferencias estadísticas con la esperada por la ecuación de Kleiber así como con la esperada para especies filogenéticamente relacionadas. Tampoco fueron detectadas diferencias significativas en la BMR entre sexos. La tasa metabólica de actividad diaria para ambos sexos fue el 235 % de la BMR. La temperatura corporal no presentó variaciones entre individuos mantenidos a diferentes temperaturas ambiente ni tampoco entre sexos y en termoneutralidad fue de 36,1 ± 1,5 °C. Por otra parte, la conductancia térmica fue menor a la esperada mientras que la capacidad termorregulatoria fue el 136% de la esperada. Akodon azarae no presenta sopor

  1. Negative relationships between population density and metabolic rates are not general.

    Science.gov (United States)

    Yashchenko, Varvara; Fossen, Erlend Ignacio; Kielland, Øystein Nordeide; Einum, Sigurd

    2016-07-01

    Population density has recently been suggested to be an important factor influencing metabolic rates and to represent an important 'third axis' explaining variation beyond that explained by body mass and temperature. In situations where population density influences food consumption, the immediate effect on metabolism acting through specific dynamic action (SDA), and downregulation due to fasting over longer periods, is well understood. However, according to a recent review, previous studies suggest a more general effect of population density per se, even in the absence of such effects. It has been hypothesized that this results from animals performing anticipatory responses (i.e. reduced activity) to expected declines in food availability. Here, we test the generality of this finding by measuring density effects on metabolic rates in 10 clones from two different species of the zooplankton Daphnia (Daphnia pulex Leydig and D. magna Straus). Using fluorescence-based respirometry, we obtain high-precision measures of metabolism. We also identify additional studies on this topic that were not included in the previous review, compare the results and evaluate the potential for measurement bias in all previous studies. We demonstrate significant variation in mass-specific metabolism among clones within both species. However, we find no evidence for a negative relationship between population density and mass-specific metabolism. The previously reported pattern also disappeared when we extended the set of studies analysed. We discuss potential reasons for the discrepancy among studies, including two main sources of potential bias (microbial respiration and declining oxygen consumption due to reduced oxygen availability). Only one of the previous studies gives sufficient information to conclude the absence of such biases, and consistent with our results, no effect of density on metabolism was found. We conclude that population density per se does not have a general effect

  2. Measuring Rates of Herbicide Metabolism in Dicot Weeds with an Excised Leaf Assay.

    Science.gov (United States)

    Ma, Rong; Skelton, Joshua J; Riechers, Dean E

    2015-09-07

    In order to isolate and accurately determine rates of herbicide metabolism in an obligate-outcrossing dicot weed, waterhemp (Amaranthus tuberculatus), we developed an excised leaf assay combined with a vegetative cloning strategy to normalize herbicide uptake and remove translocation as contributing factors in herbicide-resistant (R) and -sensitive (S) waterhemp populations. Biokinetic analyses of organic pesticides in plants typically include the determination of uptake, translocation (delivery to the target site), metabolic fate, and interactions with the target site. Herbicide metabolism is an important parameter to measure in herbicide-resistant weeds and herbicide-tolerant crops, and is typically accomplished with whole-plant tests using radiolabeled herbicides. However, one difficulty with interpreting biokinetic parameters derived from whole-plant methods is that translocation is often affected by rates of herbicide metabolism, since polar metabolites are usually not mobile within the plant following herbicide detoxification reactions. Advantages of the protocol described in this manuscript include reproducible, accurate, and rapid determination of herbicide degradation rates in R and S populations, a substantial decrease in the amount of radiolabeled herbicide consumed, a large reduction in radiolabeled plant materials requiring further handling and disposal, and the ability to perform radiolabeled herbicide experiments in the lab or growth chamber instead of a greenhouse. As herbicide resistance continues to develop and spread in dicot weed populations worldwide, the excised leaf assay method developed and described herein will provide an invaluable technique for investigating non-target site-based resistance due to enhanced rates of herbicide metabolism and detoxification.

  3. DIFFERENCES IN POST HATCH METABOLIC RATE AND DEVELOPMENTAL RATE IN ATLANTIC SALMON (SALMO SALAR L): EVIDENCE FOR COMPENSATORY GROWTH?

    DEFF Research Database (Denmark)

    Steffensen, John Fleng

    2010-01-01

    in six out of 91 families, the three families with earliest and the three families with latest time to hatch. Measurements were done on two occasions, at 570-580 (T1) and 600-610 (T2) day degrees from fertilization. Generally, VO2 increased and yolk was consumed between T1 and T2. Late hatching larvae...... and had higher metabolic rate in T1 suggests that these inherited differences can be even out by accelerated post hatch growth....

  4. The relationship of sleep with temperature and metabolic rate in a hibernating primate.

    Directory of Open Access Journals (Sweden)

    Andrew D Krystal

    Full Text Available STUDY OBJECTIVES: It has long been suspected that sleep is important for regulating body temperature and metabolic-rate. Hibernation, a state of acute hypothermia and reduced metabolic-rate, offers a promising system for investigating those relationships. Prior studies in hibernating ground squirrels report that, although sleep occurs during hibernation, it manifests only as non-REM sleep, and only at relatively high temperatures. In our study, we report data on sleep during hibernation in a lemuriform primate, Cheirogaleus medius. As the only primate known to experience prolonged periods of hibernation and as an inhabitant of more temperate climates than ground squirrels, this animal serves as an alternative model for exploring sleep temperature/metabolism relationships that may be uniquely relevant to understanding human physiology. MEASUREMENTS AND RESULTS: We find that during hibernation, non-REM sleep is absent in Cheirogaleus. Rather, periods of REM sleep occur during periods of relatively high ambient temperature, a pattern opposite of that observed in ground squirrels. Like ground squirrels, however, EEG is marked by ultra-low voltage activity at relatively low metabolic-rates. CONCLUSIONS: These findings confirm a sleep-temperature/metabolism link, though they also suggest that the relationship of sleep stage with temperature/metabolism is flexible and may differ across species or mammalian orders. The absence of non-REM sleep suggests that during hibernation in Cheirogaleus, like in the ground squirrel, the otherwise universal non-REM sleep homeostatic response is greatly curtailed or absent. Lastly, ultra-low voltage EEG appears to be a cross-species marker for extremely low metabolic-rate, and, as such, may be an attractive target for research on hibernation induction.

  5. [Resting metabolic rate, stress, testosterone, and induced immune response in "spring" and "fall" males of Campbell dwarf hamsters. Rearing under the long day conditions].

    Science.gov (United States)

    Rogovin, K A; Bushuev, A V; Khrushchova, A M; Vasil'eva, N Iu

    2013-01-01

    We have studied morphological and physiological traits of even-young males of Campbell dwarf hamsters (Phodopus campbelli Thomas, 1905) born at the end of summer ("fall males") and at the end of winter ("spring males") in a vivarium with constant 14-hour day length (14D:10N). After removal from parental cages at the age of one month, males were kept in isolation under the same light conditions. The results obained signify the statistical difference between "fall" and "spring" males in resting metabolic rate, morphological traits associated with sexual activity, some endocrine and immunologic characteristics. Spring males had higher resting metabolic rate, higher body mass in the middle of experiment, bigger testes, seminal vesicles, higher concentration of testosterone in blood and more intensive T-cell immune response to the intracutaneous injection of phytohemagglutinin. They did not differ significantly in basal level of blood cortisole and antibodies production in response to sheep red blood cells (SRBC) antigen challenge, but possessed lower adrenocortical response to the social stressor and adrenocorticotropic hormone. GLM analysis showed that cortisol level in blood after 10 min encounter of males in the open arena, and resting metabolic rate were the only factors significantly influenced humoral immune response to SRBC. When intensity of T-cell immune response was considered as dependent variable, season turned out to be the only factor in the final model that caused a significant effect.

  6. Increasing metabolic rate despite declining body weight in an adult parasitoid wasp.

    Science.gov (United States)

    Casas, Jérôme; Body, Mélanie; Gutzwiller, Florence; Giron, David; Lazzari, Claudio R; Pincebourde, Sylvain; Richard, Romain; Llandres, Ana L

    2015-08-01

    Metabolic rate is a positive function of body weight, a rule valid for most organisms and the basis of several theories of metabolic ecology. For adult insects, however, the diversity of relationships between body mass and respiration remains unexplained. The aim of this study is to relate the respiratory metabolism of a parasitoid with body weight and foraging activity. We compared the metabolic rate of groups of starving and host-fed females of the parasitoid Eupelmus vuilleti recorded with respirometry for 7days, corresponding to the mean lifetime of starving females and over half of the lifetime of foraging females. The dynamics of carbohydrate, lipid and protein in the body of foraging females were quantified with biochemical techniques. Body mass and all body nutrients declined sharply from the first day onwards. By contrast, the CO2 produced and the O2 consumed increased steadily. Starving females showed the opposite trend, identifying foraging as the reason for the respiration increase of feeding females. Two complementary physiological processes explain the unexpected relationship between increasing metabolic rate and declining body weight. First, host hemolymph is a highly unbalanced food, and the excess nutrients (protein and carbohydrate) need to be voided, partially through excretion and partially through respiration. Second, a foraging young female produces eggs at an increasing rate during the first half of its lifetime, a process that also increases respiration. We posit that the time-varying metabolic rate contributions of the feeding and reproductive processes supplements the contribution of the structural mass and lead to the observed trend. We extend our explanations to other insect groups and discuss the potential for unification using Dynamic Energy Budget theory.

  7. Physiological pace of life: the link between constitutive immunity, developmental period, and metabolic rate in European birds.

    Science.gov (United States)

    Pap, Péter László; Vágási, Csongor István; Vincze, Orsolya; Osváth, Gergely; Veres-Szászka, Judit; Czirják, Gábor Árpád

    2015-01-01

    Constitutive innate immunity is the first lined of defence against infections, but the causes determining its variability among species are poorly understood. The pace of life hypothesis predicts that species with a fast speed of life, characterized by high energy turnover and short developmental time, invest relatively little in defence in favour of growth and early reproduction, whereas 'slow-living' species are predicted to invest more resources into costly defence. We conducted phylogenetic comparative analysis on 105 European bird species and determined that the number of leukocytes, and the levels of natural antibodies (NAbs) and complement, measured on adult birds, increased or tended to positively correlate with the length of incubation period. However, we found that the length of incubation and fledging periods have opposite effects on immune defence (i.e. immune parameters show a negative association with the length of fledging period). Our results suggest that the contrasting effects of the incubation and fledging periods are related to the timing of the development of immune cells and of NAbs and complement, which largely mature during the embryonic phase of development. In support of this hypothesis, we found that species with a long relative incubation period [i.e. whose total pre-fledging developmental time (incubation plus fledging) consists largely of the incubation period] invested more in constitutive innate immunity. Finally, in support of the pace of life hypothesis, for a subsample of 63 species, we found that the basal metabolic rate significantly or tended to negatively correlate with immune measures.

  8. How does a fish's metabolic rate influence its performance in a changing environment?

    Directory of Open Access Journals (Sweden)

    Neil Metcalfe

    2015-12-01

    Full Text Available Fish provide some of the best-studied examples of marked intraspecific variation in metabolic rate: after accounting for variation in size and age, there can typically be a 2-3 fold variation among individual fish for both standard and maximum metabolic rate (SMR and MMR, and also in their aerobic scope (AS, the difference between SMR and MMR and hence a fish’s capacity to increase its aerobic metabolism. These differences are relatively stable over time, although individual fish differ in the extent to which they can alter their metabolism when environmental conditions change. In this presentation I will briefly consider the extent and causes of individual variation in SMR, MMR and AS, considering both the mechanistic basis (e.g. individual variation in mitochondrial performance and its origins, including a consideration of genetic and maternal effects. I will then describe both documented and potential links between metabolism, behaviour and performance. Intraspecific variation in metabolism has been found to be related to other traits. As an example, fish with a relatively high SMR tend to be more dominant, digest food faster and grow faster than those with a low SMR, but these advantages only apply in environments where the food supply is high and predictable; in less favourable environments they lose their advantage, and are more prone to risk-taking when conditions deteriorate. Less is known about the ecological consequences of individual variation in MMR and AS, although fish with a higher AS are known to have advantages in some contexts. This is especially important in the context of climate change, since it has been suggested that constraints on AS may underlie the poor performance of fishes at higher temperatures. Given these links between metabolism and measures of performance, understanding the metabolic responses of individuals to changing environments will be a key area for future research.

  9. High-intensity interval training without weight loss improves exercise but not basal or insulin-induced metabolism in overweight/obese African American women.

    Science.gov (United States)

    Arad, Avigdor D; DiMenna, Fred J; Thomas, Naketa; Tamis-Holland, Jacqueline; Weil, Richard; Geliebter, Allan; Albu, Jeanine B

    2015-08-15

    The purpose of this randomized controlled clinical trial was to determine the effect of a 14-week high-intensity interval training (HIIT) intervention with weight stability on metabolic flexibility, insulin sensitivity, and cardiorespiratory fitness in sedentary, premenopausal, nondiabetic, overweight/obese African American women. Twenty-eight subjects were allocated to one of two groups: HIIT, which performed three sessions per week of four high-intensity cycling intervals, or a control group (CON), which maintained their normal level of physical activity. Diet was controlled for all subjects to ensure weight stability. Pre- and postintervention (pre/post), subjects completed an incremental cycling test to limit of tolerance and, following a 10-day high-fat controlled feeding period, a euglycemic-hyperinsulinemic clamp to determine insulin sensitivity and substrate oxidation. Nine members of HIIT (age, 29 ± 4 yr; body mass, 90.1 ± 13.8 kg) and eleven members of CON (age, 30 ± 7 yr; body mass, 85.5 ± 10.7 kg) completed the study. HIIT experienced an increased limit of tolerance (post, 1,124 ± 202 s; pre, 987 ± 146 s; P exchange threshold (post, 1.29 ± 0.34 liters/min; pre, 0.97 ± 0.23 liters/min; P rate compared with CON (P flexibility were not different in HIIT compared with CON. High-intensity interval training with weight stability increased exercise fat oxidation and tolerance in subjects at risk for diabetic progression, but did not improve insulin sensitivity or fat oxidation in the postabsorptive or insulin-stimulated state.

  10. Metabolic Syndrome and Short-Term Heart Rate Variability in Adults with Intellectual Disabilities

    Science.gov (United States)

    Chang, Yaw-Wen; Lin, Jin-Ding; Chen, Wei-Liang; Yen, Chia-Feng; Loh, Ching-Hui; Fang, Wen-Hui; Wu, Li-Wei

    2012-01-01

    Metabolic syndrome (MetS) increases the risk of cardiovascular events. Heart rate variability (HRV) represents autonomic functioning, and reduced HRV significantly increases cardiovascular mortality. The aims of the present paper are to assess the prevalence of MetS in adults with intellectual disabilities (ID), the difference in short-term HRV…

  11. Brain Size and Cerebral Glucose Metabolic Rate in Nonspecific Retardation and Down Syndrome.

    Science.gov (United States)

    Haier, Richard J.; And Others

    1995-01-01

    Brain size and cerebral glucose metabolic rate were determined for 10 individuals with mild mental retardation (MR), 7 individuals with Down syndrome (DS), and 10 matched controls. MR and DS groups both had brain volumes of about 80% compared to controls, with variance greatest within the MR group. (SLD)

  12. Resting metabolic rate in Italians : relation with body composition and anthropometric parameters

    NARCIS (Netherlands)

    Lorenzo, de A.; Andreoli, A.; Bertoli, S.; Testolin, G.; Oriani, G.; Deurenberg, P.

    2000-01-01

    The objectives of this study were to obtain values for resting metabolic rate in Italians in relation to parameters of body composition, and to compare them to predicted values using the FAO/WHO/UNU equation. We performed a cross-sectional observational study of 131 healthy subjects (46 males and 85

  13. Metabolic rate and clothing insulation data of children and adolescents during various school activities

    NARCIS (Netherlands)

    Havenith, G.

    2007-01-01

    Data on metabolic rates (n = 0;81) and clothing insulation (n = 96) of school children and adolescents (A, primary school: age 9-10; B, primary school: age 10-11 year; C, junior vocational (technical) education: age 13-16 (lower level); D, same as C but at advanced level; and E, senior vocational (t

  14. Novel Method of Estimating Metabolic Rates of Soldiers Engaged in Chemical Biological Defense Training

    Science.gov (United States)

    2016-12-01

    SOLDIERS ENGAGED IN CHEMICAL BIOLOGICAL DEFENSE TRAINING DISCLAIMER The opinions or assertions contained herein are the private views of the...USARIEM TECHNICAL REPORT TR17-02 NOVEL METHOD OF ESTIMATING METABOLIC RATES OF SOLDIERS ENGAGED IN CHEMICAL BIOLOGICAL DEFENSE TRAINING ...Volunteers ............................................................................................................ 2 Training Activities

  15. Metabolic Rate: A Factor in Developing Obesity in Children with Down Syndrome?

    Science.gov (United States)

    Chad, Karen; And Others

    1990-01-01

    Resting metabolic rate and its relation to selected anthropomorphic measures were determined in 11 male and 7 female noninstitutionalized children with Down Syndrome. Dietary analysis was performed to determine the children's nutritional status. Results have implications for the prevention and treatment of obesity in children with Down Syndrome.…

  16. Resting Metabolic Rate is Not Reduced in Obese Adults With Down Syndrome

    Science.gov (United States)

    Fernhall, Bo; Figueroa, Arturo; Collier, Scott; Goulopoulou, Styliani; Giannopoulou, Ifigenia; Baynard, Tracy

    2005-01-01

    Resting metabolic rate (RMR) of 22 individuals with Down syndrome was compared to that of 20 nondisabled control individuals of similar age (25.7 and 27.4 years, respectively). Using a ventilated hood system, we measured RMR in the early morning after an overnight fast. Peak aerobic capacity Volume of Oxygen (VO2 peak) and body composition were…

  17. Dietary supplement increases plasma norepinephrine, lipolysis, and metabolic rate in resistance trained men

    OpenAIRE

    Schilling Brian K; Hammond Kelley G; Fisher-Wellman Kelsey H; Bloomer Richard J; Weber Adrianna A; Cole Bradford J

    2009-01-01

    Abstract Correction to Richard J Bloomer, Kelsey H Fisher-Wellman, Kelley G Hammond, Brian K Schilling, Adrianna A Weber and Bradford J Cole: Dietary supplement increases plasma norepinephrine, lipolysis, and metabolic rate in resistance trained men. Journal of the International Society of Sports Nutrition 2009, 6: 4

  18. Dietary supplement increases plasma norepinephrine, lipolysis, and metabolic rate in resistance trained men

    Directory of Open Access Journals (Sweden)

    Schilling Brian K

    2009-04-01

    Full Text Available Abstract Correction to Richard J Bloomer, Kelsey H Fisher-Wellman, Kelley G Hammond, Brian K Schilling, Adrianna A Weber and Bradford J Cole: Dietary supplement increases plasma norepinephrine, lipolysis, and metabolic rate in resistance trained men. Journal of the International Society of Sports Nutrition 2009, 6: 4

  19. Individual (co)variation in standard metabolic rate, feeding rate, and exploratory behavior in wild-caught semiaquatic salamanders.

    Science.gov (United States)

    Gifford, Matthew E; Clay, Timothy A; Careau, Vincent

    2014-01-01

    Repeatability is an important concept in evolutionary analyses because it provides information regarding the benefit of repeated measurements and, in most cases, a putative upper limit to heritability estimates. Repeatability (R) of different aspects of energy metabolism and behavior has been demonstrated in a variety of organisms over short and long time intervals. Recent research suggests that consistent individual differences in behavior and energy metabolism might covary. Here we present new data on the repeatability of body mass, standard metabolic rate (SMR), voluntary exploratory behavior, and feeding rate in a semiaquatic salamander and ask whether individual variation in behavioral traits is correlated with individual variation in metabolism on a whole-animal basis and after conditioning on body mass. All measured traits were repeatable, but the repeatability estimates ranged from very high for body mass (R = 0.98), to intermediate for SMR (R = 0.39) and food intake (R = 0.58), to low for exploratory behavior (R = 0.25). Moreover, repeatability estimates for all traits except body mass declined over time (i.e., from 3 to 9 wk), although this pattern could be a consequence of the relatively low sample size used in this study. Despite significant repeatability in all traits, we find little evidence that behaviors are correlated with SMR at the phenotypic and among-individual levels when conditioned on body mass. Specifically, the phenotypic correlations between SMR and exploratory behavior were negative in all trials but significantly so in one trial only. Salamanders in this study showed individual variation in how their exploratory behavior changed across trials (but not body mass, SMR, and feed intake), which might have contributed to observed changing correlations across trials.

  20. The effect of microbial glucose metabolism on bytownite feldspar dissolution rates between 5 and 35 C

    Energy Technology Data Exchange (ETDEWEB)

    Welch, S.A.; Ullman, W.J.

    1999-10-01

    The rate of Si release from dissolving bytownite feldspar in abiotic batch reactors increased as temperatures increased from 5 to 35 C. Metabolically inert subsurface bacteria (bacteria in solution with no organic substrate) had no apparent effect on dissolution rates over this temperature range. When glucose was added to the microbial cultures, the bacteria responded by producing gluconic acid, which catalyzed the dissolution reaction by both proton- and ligand-promoted mechanisms. The metabolic production, excretion, and consumption of gluconic acid in the course of glucose oxidation, and therefore, the degree of microbial enhancement of mineral dissolution, depend on temperature. There was little accumulation of gluconic acid and therefore, no significant enhancement of mineral dissolution rates at 35 C compared to the abiotic controls. At 20 C, gluconate accumulated in the experimental solutions only at the beginning of the experiment and led to a twofold increase in dissolved Si release compared to the controls, primarily by the ligand-promoted dissolution mechanism. There was significant accumulation of gluconic acid in the 5 C experiment, which is reflected in a significant reduction in pH, leading to 20-fold increase in Si release, primarily attributable to the proton-promoted dissolution mechanism. These results indicate that bacteria and microbial metabolism can affect mineral dissolution rates in organic-rich, nutrient-poor environments; the impact of microbial metabolism on aluminum silicate dissolution rates may be greater at lower rather than at higher temperatures due to the metabolic accumulation of dissolution-enhancing protons and ligands in solution.

  1. Sustained metabolic scope.

    Science.gov (United States)

    Peterson, C C; Nagy, K A; Diamond, J

    1990-03-01

    Sustained metabolic rates (SusMR) are time-averaged metabolic rates that are measured in free-ranging animals maintaining constant body mass over periods long enough that metabolism is fueled by food intake rather than by transient depletion of energy reserves. Many authors have suggested that SusMR of various wild animal species are only a few times resting (basal or standard) metabolic rates (RMR). We test this conclusion by analyzing all 37 species (humans, 31 other endothermic vertebrates, and 5 ectothermic vertebrates) for which SusMR and RMR had both been measured. For all species, the ratio of SusMR to RMR, which we term sustained metabolic scope, is less than 7; most values fall between 1.5 and 5. Some of these values, such as those for Tour de France cyclists and breeding birds, are surely close to sustainable metabolic ceilings for the species studied. That is, metabolic rates higher than 7 times RMR apparently cannot be sustained indefinitely. These observations pose several questions: whether the proximate physiological causes of metabolic ceilings reside in the digestive tract's ability to process food or in each tissue's metabolic capacity; whether ceiling values are independent of the mode of energy expenditure; whether ceilings are set by single limiting physiological capacities or by coadjusted clusters of capacities (symmorphosis); what the ultimate evolutionary causes of metabolic ceilings are; and how metabolic ceilings may limit animals' reproductive effort, foraging behavior, and geographic distribution.

  2. Evidence of circadian rhythm, oxygen regulation capacity, metabolic repeatability and positive correlations between forced and spontaneous maximal metabolic rates in lake sturgeon Acipenser fulvescens.

    Directory of Open Access Journals (Sweden)

    Jon C Svendsen

    Full Text Available Animal metabolic rate is variable and may be affected by endogenous and exogenous factors, but such relationships remain poorly understood in many primitive fishes, including members of the family Acipenseridae (sturgeons. Using juvenile lake sturgeon (Acipenser fulvescens, the objective of this study was to test four hypotheses: 1 A. fulvescens exhibits a circadian rhythm influencing metabolic rate and behaviour; 2 A. fulvescens has the capacity to regulate metabolic rate when exposed to environmental hypoxia; 3 measurements of forced maximum metabolic rate (MMR(F are repeatable in individual fish; and 4 MMR(F correlates positively with spontaneous maximum metabolic rate (MMR(S. Metabolic rates were measured using intermittent flow respirometry, and a standard chase protocol was employed to elicit MMR(F. Trials lasting 24 h were used to measure standard metabolic rate (SMR and MMR(S. Repeatability and correlations between MMR(F and MMR(S were analyzed using residual body mass corrected values. Results revealed that A. fulvescens exhibit a circadian rhythm in metabolic rate, with metabolism peaking at dawn. SMR was unaffected by hypoxia (30% air saturation (O(2sat, demonstrating oxygen regulation. In contrast, MMR(F was affected by hypoxia and decreased across the range from 100% O(2sat to 70% O(2sat. MMR(F was repeatable in individual fish, and MMR(F correlated positively with MMR(S, but the relationships between MMR(F and MMR(S were only revealed in fish exposed to hypoxia or 24 h constant light (i.e. environmental stressor. Our study provides evidence that the physiology of A. fulvescens is influenced by a circadian rhythm and suggests that A. fulvescens is an oxygen regulator, like most teleost fish. Finally, metabolic repeatability and positive correlations between MMR(F and MMR(S support the conjecture that MMR(F represents a measure of organism performance that could be a target of natural selection.

  3. Timing and Variability of Galactose Metabolic Gene Activation Depend on the Rate of Environmental Change.

    Directory of Open Access Journals (Sweden)

    Truong D Nguyen-Huu

    2015-07-01

    Full Text Available Modulation of gene network activity allows cells to respond to changes in environmental conditions. For example, the galactose utilization network in Saccharomyces cerevisiae is activated by the presence of galactose but repressed by glucose. If both sugars are present, the yeast will first metabolize glucose, depleting it from the extracellular environment. Upon depletion of glucose, the genes encoding galactose metabolic proteins will activate. Here, we show that the rate at which glucose levels are depleted determines the timing and variability of galactose gene activation. Paradoxically, we find that Gal1p, an enzyme needed for galactose metabolism, accumulates more quickly if glucose is depleted slowly rather than taken away quickly. Furthermore, the variability of induction times in individual cells depends non-monotonically on the rate of glucose depletion and exhibits a minimum at intermediate depletion rates. Our mathematical modeling suggests that the dynamics of the metabolic transition from glucose to galactose are responsible for the variability in galactose gene activation. These findings demonstrate that environmental dynamics can determine the phenotypic outcome at both the single-cell and population levels.

  4. Metabolic rates of the antarctic amphipod Gondogeneia antarctica at different temperatures and salinities

    Directory of Open Access Journals (Sweden)

    Vicente Gomes

    2013-12-01

    Full Text Available Changes in environmental factors may deeply affect the energy budget of Antarctic organisms as many of them are stenothermal and/or stenohaline ectotherms. In this context, the aim of this study is to contribute to knowledge on variations in the energy demand of the Antarctic amphipod, Gondogeneia antarctica as a function of temperature and salinity. Experiments were held at the Brazilian Antarctic Station "Comandante Ferraz", under controlled conditions. Animals collected at Admiralty Bay were acclimated to temperatures of 0ºC; 2.5ºC and 5ºC and to salinities of 35, 30 and 25. Thirty measurements were made for each of the nine combinations of the three temperatures and three salinities, totalling 270 measurements. Metabolic rates were assessed by oxygen consumption and total nitrogenous ammonia excretion, in sealed respirometers. When acclimated to salinities 30 or 35, metabolic rates at 0ºC and 2.5ºC were very similar indicating a possible mechanism of metabolic compensation for temperature. At 5.0ºC, however, metabolic rates were always higher. Lower salinities enhanced the effects of temperature on metabolism and ammonia excretion rates. The physiological adaptations of individuals of G. antarctica suggest adaptive mechanisms for energy saving, adjusted to an environment with stable conditions of temperature and salinity. Little is known about the joint effects of salinity and temperature and this study is an important contribution to the understanding of the mechanism of polar organisms in their adaptation to both factors.

  5. Community size and metabolic rates of psychrophilic sulfate-reducing bacteria in Arctic marine sediments

    DEFF Research Database (Denmark)

    Knoblauch, C.; Jørgensen, BB; Harder, J.

    1999-01-01

    The numbers of sulfate reducers in two Arctic sediments within situ temperatures of 2.6 and -1.7 degrees C were determined. Most-probable-number counts were higher at 10 degrees C than at 20 degrees C, indicating the predominance of a psychrophilic community. Mean specific sulfate reduction rates...... of 19 isolated psychrophiles were compared to corresponding rates of 9 marine, mesophilic sulfate-reducing bacteria. The results indicate that, as a physiological adaptation to the permanently cold Arctic environment, psychrophilic sulfate reducers have considerably higher specific metabolic rates than...

  6. Community size and metabolic rates of psychrophilic sulfate-reducing bacteria in Arctic marine sediments

    Energy Technology Data Exchange (ETDEWEB)

    Knoblauch, C.; Joergensen, B.B.; Harder, J.

    1999-09-01

    The numbers of sulfate reducers in two Arctic sediments with in situ temperatures of 2.6 and {minus}1.7C were determined. Most-probable-number counts were higher at 10 C than at 20 C, indicating the predominance of a psychrophilic community. Mean specific sulfate reduction rates of 19 isolated psychrophiles were compared to corresponding rates of 9 marine, mesophilic sulfate-reducing bacteria. The results indicate that, as a physiological adaptation to the permanently cold Arctic environment, psychrophilic sulfate reducers have considerably higher specific metabolic rates than their mesophilic counterparts at similarly low temperatures.

  7. Evaluation of rate law approximations in bottom-up kinetic models of metabolism

    DEFF Research Database (Denmark)

    Du, Bin; Zielinski, Daniel C.; Kavvas, Erol S.

    2016-01-01

    . These approximate rate laws were: 1) a Michaelis-Menten rate law with measured enzyme parameters, 2) a Michaelis-Menten rate law with approximated parameters, using the convenience kinetics convention, 3) a thermodynamic rate law resulting from a metabolite saturation assumption, and 4) a pure chemical reaction......Background: The mechanistic description of enzyme kinetics in a dynamic model of metabolism requires specifying the numerical values of a large number of kinetic parameters. The parameterization challenge is often addressed through the use of simplifying approximations to form reaction rate laws...... with reduced numbers of parameters. Whether such simplified models can reproduce dynamic characteristics of the full system is an important question. Results: In this work, we compared the local transient response properties of dynamic models constructed using rate laws with varying levels of approximation...

  8. A transcription factor links growth rate and metabolism in the hypersaline adapted archaeon Halobacterium salinarum.

    Science.gov (United States)

    Todor, Horia; Dulmage, Keely; Gillum, Nicholas; Bain, James R; Muehlbauer, Michael J; Schmid, Amy K

    2014-09-01

    Co-ordinating metabolism and growth is a key challenge for all organisms. Despite fluctuating environments, cells must produce the same metabolic outputs to thrive. The mechanisms underlying this 'growth homeostasis' are known in bacteria and eukaryotes, but remain unexplored in archaea. In the model archaeon Halobacterium salinarum, the transcription factor TrmB regulates enzyme-coding genes in diverse metabolic pathways in response to glucose. However, H. salinarum is thought not to catabolize glucose. To resolve this discrepancy, we demonstrate that TrmB regulates the gluconeogenic production of sugars incorporated into the cell surface S-layer glycoprotein. Additionally, we show that TrmB-DNA binding correlates with instantaneous growth rate, likely because S-layer glycosylation is proportional to growth. This suggests that TrmB transduces a growth rate signal to co-regulated metabolic pathways including amino acid, purine, and cobalamin biosynthesis. Remarkably, the topology and function of this growth homeostatic network appear conserved across domains despite extensive alterations in protein components.

  9. Metabolic rate and gross efficiency at high work rates in world class and national level sprint skiers.

    Science.gov (United States)

    Sandbakk, Øyvind; Holmberg, Hans-Christer; Leirdal, Stig; Ettema, Gertjan

    2010-06-01

    The present study investigated metabolic rate (MR) and gross efficiency (GE) at moderate and high work rates, and the relationships to gross kinematics and physical characteristics in elite cross-country skiers. Eight world class (WC) and eight national level (NL) male sprint cross-country skiers performed three 5-min stages using the skating G3 technique, whilst roller skiing on a treadmill. GE was calculated by dividing work rate by MR. Work rate was calculated as the sum of power against gravity and frictional rolling forces. MR was calculated using gas exchange and blood lactate values. Gross kinematics, i.e. cycle length (CL) and cycle rate (CR) were measured by video analysis. Furthermore, the skiers were tested for time to exhaustion (TTE), peak oxygen uptake (VO(2peak)), and maximal speed (V(max)) on the treadmill, and maximal strength in the laboratory. Individual performance level in sprint skating was determined by FIS points. WC skiers did not differ in aerobic MR, but showed lower anaerobic MR and higher GE than NL skiers at a given speed (all P < 0.05). Moreover, WC skiers skated with longer CL and had higher V(max) and TTE (all P < 0.05). In conclusion, the present study shows that WC skiers are more efficient than NL skiers, and it is proposed that this might be due to a better technique and to technique-specific power.

  10. Resting metabolic rate and heat increment of feeding in juvenile South American fur seals (Arctocephalus australis).

    Science.gov (United States)

    Dassis, M; Rodríguez, D H; Ieno, E N; Denuncio, P E; Loureiro, J; Davis, R W

    2014-02-01

    Bio-energetic models used to characterize an animal's energy budget require the accurate estimate of different variables such as the resting metabolic rate (RMR) and the heat increment of feeding (HIF). In this study, we estimated the in air RMR of wild juvenile South American fur seals (SAFS; Arctocephalus australis) temporarily held in captivity by measuring oxygen consumption while at rest in a postabsorptive condition. HIF, which is an increase in metabolic rate associated with digestion, assimilation and nutrient interconversion, was estimated as the difference in resting metabolic rate between the postabsorptive condition and the first 3.5h postprandial. As data were hierarchically structured, linear mixed effect models were used to compare RMR measures under both physiological conditions. Results indicated a significant increase (61%) for the postprandial RMR compared to the postabsorptive condition, estimated at 17.93±1.84 and 11.15±1.91mL O2 min(-1)kg(-1), respectively. These values constitute the first estimation of RMR and HIF in this species, and should be considered in the energy budgets for juvenile SAFS foraging at-sea.

  11. Land use effects and stream metabolic rates: a review of ecosystem response

    Directory of Open Access Journals (Sweden)

    Eduardo Francisco da Silva-Junior

    Full Text Available Abstract Aim To conduct a review of the literature in order to identify the general stream metabolic responses to land use change. Methods I conducted a scientometric review analyzing the distribution of the studies among different environments, the land use scale used, and the general trends in stream metabolism response under each kind of land-use impact. Major Results Most of the analyzed studies were conducted in temperate environments, studying land-use impacts at catchment scale. Ecosystem metabolism responded to land use impacts most of the cases, especially under agricultural pressure. The general responses to land-use alterations were increases in rates of Gross Primary Production (GPP and ecosystem Respiration (R. Primary production increases were mostly related to light and nutrient concentration increases, while R was usually related to water nutrient concentration, temperature and amount of particulate organic matter, but this general behavior can change under high impact levels where sometimes GPP decreases in response to turbidity increases. Riparian vegetation restoration have a positive effect in driving stream metabolic conditions in the direction of pristine condition, but the effectiveness of this approach is reduced in highly impacted systems. Conclusions To elucidate the mechanistic relations between stream metabolic changes and land use impacts is still one fundamental aspect to study in order to best predict effects of land use changes and establish management and protection programs. Thus, studies should focus on the causative relations between stream processes and land use changes considering different scales and multiple stress scenarios in order to improve our understanding about factors that drive the observed metabolic changes.

  12. Cold- and exercise-induced peak metabolic rates in tropical birds

    OpenAIRE

    Wiersma, Popko; Chappell, Mark A; Williams, Joseph B.

    2007-01-01

    Compared with temperate birds, tropical birds have low reproductive rates, slow development as nestlings, and long lifespans. These “slow” life history traits are thought to be associated with reduced energy expenditure, or a slow “pace of life.” To test predictions from this hypothesis, we measured exercise-induced peak metabolic rates (PMRE) in 45 species of tropical lowland forest birds and compared these data with PMRE for three temperate species. We also compared cold-induced PMR (PMRC) ...

  13. Transient and permanent effects of suboptimal incubation temperatures on growth, metabolic rate, immune function and adrenocortical responses in zebra finches.

    Science.gov (United States)

    Wada, Haruka; Kriengwatana, Buddhamas; Allen, Natalie; Schmidt, Kimberly L; Soma, Kiran K; MacDougall-Shackleton, Scott A

    2015-09-01

    In birds, incubation temperature can vary by several degrees Celsius among nests of a given species. Parents may alter incubation temperature to cope with environmental conditions and/or to manipulate embryonic development, and such changes in incubation behavior could have long-lasting effects on offspring phenotype. To investigate short- and long-term effects of suboptimal incubation temperatures on survival and physiological functions in zebra finches, eggs were incubated at 36.2, 37.4 or 38.4 °C for the entire incubation period. The post-hatch environment was identical among the treatment groups. We found that hatching success was lowest in the 38.4 °C group, while post-hatch survival was lowest in the 36.2 °C group. Incubation temperature had sex-specific effects on offspring phenotype: incubation temperatures affected body mass (Mb) but not physiological parameters of males and conversely, the physiological parameters but not Mb of females. Specifically, males from the 38.4 °C group weighed significantly less than males from the 36.2 °C group from the nestling period to adulthood, whereas females from different incubation temperature groups did not differ in Mb. In contrast, females incubated at 36.2 °C had transient but significantly elevated basal metabolic rate and adrenocortical responses during the nestling and fledgling periods, whereas no treatment effect was observed in males. Innate immunity was not affected by incubation temperature in either sex. These results suggest that a 1 °C deviation from what is considered an optimal incubation temperature can lower offspring performance and offspring survival.

  14. Food composition influences metabolism, heart rate and organ growth during digestion in Python regius.

    Science.gov (United States)

    Henriksen, Poul Secher; Enok, Sanne; Overgaard, Johannes; Wang, Tobias

    2015-05-01

    Digestion in pythons is associated with a large increase in oxygen consumption (SDA), increased cardiac output and growth in visceral organs assisting in digestion. The processes leading to the large postprandial rise in metabolism in snakes is subject to opposing views. Gastric work, protein synthesis and organ growth have each been speculated to be major contributors to the SDA. To investigate the role of food composition on SDA, heart rate (HR) and organ growth, 48 ball pythons (Python regius) were fed meals of either fat, glucose, protein or protein combined with carbonate. Our study shows that protein, in the absence or presence of carbonate causes a large SDA response, while glucose caused a significantly smaller SDA response and digestion of fat failed to affect metabolism. Addition of carbonate to the diet to stimulate gastric acid secretion did not increase the SDA response. These results support protein synthesis as a major contributor to the SDA response and show that increased gastric acid secretion occurs at a low metabolic cost. The increase in metabolism was supported by tachycardia caused by altered autonomic regulation as well as an increased non-adrenergic, non-cholinergic (NANC) tone in response to all diets, except for the lipid meal. Organ growth only occurred in the small intestine and liver in snakes fed on a high protein diet.

  15. Intraspecific variation in flight metabolic rate in the bumblebee Bombus impatiens: repeatability and functional determinants in workers and drones.

    Science.gov (United States)

    Darveau, Charles-A; Billardon, Fannie; Bélanger, Kasandra

    2014-02-15

    The evolution of flight energetics requires that phenotypes be variable, repeatable and heritable. We studied intraspecific variation in flight energetics in order to assess the repeatability of flight metabolic rate and wingbeat frequency, as well as the functional basis of phenotypic variation in workers and drones of the bumblebee species Bombus impatiens. We showed that flight metabolic rate and wingbeat frequency were highly repeatable in workers, even when controlling for body mass variation using residual analysis. We did not detect significant repeatability in drones, but a smaller range of variation might have prevented us from finding significant values in our sample. Based on our results and previous findings, we associated the high repeatability of flight phenotypes in workers to the functional links between body mass, thorax mass, wing size, wingbeat frequency and metabolic rate. Moreover, differences between workers and drones were as predicted from these functional associations, where drones had larger wings for their size, lower wingbeat frequency and lower flight metabolic rate. We also investigated thoracic muscle metabolic phenotypes by measuring the activity of carbohydrate metabolism enzymes, and we found positive correlations between mass-independent metabolic rate and the activity of all enzymes measured, but in workers only. When comparing workers and drones that differ in flight metabolic rate, only the activity of the enzymes hexokinase and trehalase showed the predicted differences. Overall, our study indicates that there should be correlated evolution among physiological phenotypes at multiple levels of organization and morphological traits associated with flight.

  16. Measuring maximum and standard metabolic rates using intermittent-flow respirometry: a student laboratory investigation of aerobic metabolic scope and environmental hypoxia in aquatic breathers.

    Science.gov (United States)

    Rosewarne, P J; Wilson, J M; Svendsen, J C

    2016-01-01

    Metabolic rate is one of the most widely measured physiological traits in animals and may be influenced by both endogenous (e.g. body mass) and exogenous factors (e.g. oxygen availability and temperature). Standard metabolic rate (SMR) and maximum metabolic rate (MMR) are two fundamental physiological variables providing the floor and ceiling in aerobic energy metabolism. The total amount of energy available between these two variables constitutes the aerobic metabolic scope (AMS). A laboratory exercise aimed at an undergraduate level physiology class, which details the appropriate data acquisition methods and calculations to measure oxygen consumption rates in rainbow trout Oncorhynchus mykiss, is presented here. Specifically, the teaching exercise employs intermittent flow respirometry to measure SMR and MMR, derives AMS from the measurements and demonstrates how AMS is affected by environmental oxygen. Students' results typically reveal a decline in AMS in response to environmental hypoxia. The same techniques can be applied to investigate the influence of other key factors on metabolic rate (e.g. temperature and body mass). Discussion of the results develops students' understanding of the mechanisms underlying these fundamental physiological traits and the influence of exogenous factors. More generally, the teaching exercise outlines essential laboratory concepts in addition to metabolic rate calculations, data acquisition and unit conversions that enhance competency in quantitative analysis and reasoning. Finally, the described procedures are generally applicable to other fish species or aquatic breathers such as crustaceans (e.g. crayfish) and provide an alternative to using higher (or more derived) animals to investigate questions related to metabolic physiology.

  17. Mathematical model of cycad cones' thermogenic temperature responses: inverse calorimetry to estimate metabolic heating rates.

    Science.gov (United States)

    Roemer, R B; Booth, D; Bhavsar, A A; Walter, G H; Terry, L I

    2012-12-21

    A mathematical model based on conservation of energy has been developed and used to simulate the temperature responses of cones of the Australian cycads Macrozamia lucida and Macrozamia. macleayi during their daily thermogenic cycle. These cones generate diel midday thermogenic temperature increases as large as 12 °C above ambient during their approximately two week pollination period. The cone temperature response model is shown to accurately predict the cones' temperatures over multiple days as based on simulations of experimental results from 28 thermogenic events from 3 different cones, each simulated for either 9 or 10 sequential days. The verified model is then used as the foundation of a new, parameter estimation based technique (termed inverse calorimetry) that estimates the cones' daily metabolic heating rates from temperature measurements alone. The inverse calorimetry technique's predictions of the major features of the cones' thermogenic metabolism compare favorably with the estimates from conventional respirometry (indirect calorimetry). Because the new technique uses only temperature measurements, and does not require measurements of oxygen consumption, it provides a simple, inexpensive and portable complement to conventional respirometry for estimating metabolic heating rates. It thus provides an additional tool to facilitate field and laboratory investigations of the bio-physics of thermogenic plants.

  18. Standard metabolic rate of the bed bug, Cimex lectularius: effects of temperature, mass, and life stage.

    Science.gov (United States)

    Devries, Zachary C; Kells, Stephen A; Appel, Arthur G

    2013-11-01

    Metabolic rates provide important information about the biology of organisms. For ectothermic species such as insects, factors such as temperature and mass heavily influence metabolism, but these effects differ considerably between species. In this study we examined the standard metabolic rate of the bed bug, Cimex lectularius L. We used closed system respirometry and measured both O2 consumption and CO2 production across a range of temperatures (10, 20, 25, 30, 35°C) and life stages, while also accounting for activity. Temperature had a stronger effect on the mass specific .VO2 (mlg(-1)h(-1)) of mated males (Q10=3.29), mated females (Q10=3.19), unmated males (Q10=3.09), and nymphs that hatched (first instars, Q10=3.05) than on unmated females (Q10=2.77) and nymphs that molted (second through fifth instars, Q10=2.78). First instars had significantly lower respiratory quotients (RQ) than all other life stages. RQ of all stages was not affected by temperature. .VO2 (mlh(-1)) scaled more with mass than values previously reported for other arthropods or that would be predicted by the 3/4-power law. The results are used to understand the biology and ecology of the bed bug.

  19. Effects of Different Protein Levels on the Growth Performance and Metabolic Rate of Nutrition in Broilers

    Institute of Scientific and Technical Information of China (English)

    WU Hongda

    2009-01-01

    The objective of this study is to determine the effect of different protein levels on the growth performance and metabolic rate of nutrition in broilers. Total 360 healthy and weight closed local broilers of 3 weeks were chosen and then divided into three groups randomly by one factor. Each group contains three handlings, each handling consists of 40 broilers. The period of experiment was 7 weeks. The metabolic experiment was performed at the 7th week. Three different protein levels were used in broilers' diet. The levels of protein were 19%, 17.5% and 16%. The results showed that the different levels of protein in crude dietary had significant difference between 19% group and the other two groups. The average daily weight gain and daily efficiency were significantly higher than that of the other two groups (P0.05), and the metabolic rate of the impact of phosphorus was significantly different (P<0.05). The result showed that when protein level was 19%, the growth of the local broiler was the best.

  20. Coffee and tea consumption in relation to inflammation and basal glucose metabolism in a multi-ethnic Asian population: a cross-sectional study

    Directory of Open Access Journals (Sweden)

    Tai E Shyong

    2011-06-01

    Full Text Available Abstract Background Higher coffee consumption has been associated with a lower risk of type 2 diabetes in cohort studies, but the physiological pathways through which coffee affects glucose metabolism are not fully understood. The aim of this study was to evaluate the associations between habitual coffee and tea consumption and glucose metabolism in a multi-ethnic Asian population and possible mediation by inflammation. Methods We cross-sectionally examined the association between coffee, green tea, black tea and Oolong tea consumption and glycemic (fasting plasma glucose, HOMA-IR, HOMA-beta, plasma HbA1c and inflammatory (plasma adiponectin and C-reactive protein markers in a multi-ethnic Asian population (N = 4139. Results After adjusting for multiple confounders, we observed inverse associations between coffee and HOMA-IR (percent difference: - 8.8% for ≥ 3 cups/day versus rarely or never; Ptrend = 0.007, but no significant associations between coffee and inflammatory markers. Tea consumption was not associated with glycemic markers, but green tea was inversely associated with plasma C-reactive protein concentrations (percent difference: - 12.2% for ≥ 1 cup/day versus Ptrend = 0.042. Conclusions These data provide additional evidence for a beneficial effect of habitual caffeinated coffee consumption on insulin sensitivity, and suggest that this effect is unlikely to be mediated by anti-inflammatory mechanisms.

  1. The effects of salt stress cause a diversion of basal metabolism in barley roots: possible different roles for glucose-6-phosphate dehydrogenase isoforms.

    Science.gov (United States)

    Cardi, Manuela; Castiglia, Daniela; Ferrara, Myriam; Guerriero, Gea; Chiurazzi, Maurizio; Esposito, Sergio

    2015-01-01

    In this study the effects of salt stress and nitrogen assimilation have been investigated in roots of hydroponically-grown barley plants exposed to 150 mM NaCl, in presence or absence of ammonium as the sole nitrogen source. Salt stress determines a diversion of root metabolism towards the synthesis of osmolytes, such as glycine betaine and proline, and increased levels of reduced glutathione. The metabolic changes triggered by salt stress result in a decrease in both activities and protein abundance of key enzymes, namely GOGAT and PEP carboxylase, and in a slight increase in HSP70. These variations would enhance the requirement for reductants supplied by the OPPP, consistently with the observed increase in total G6PDH activity. The involvement and occurrence of the different G6PDH isoforms have been investigated, and the kinetic properties of partially purified cytosolic and plastidial G6PDHs determined. Bioinformatic analyses examining co-expression profiles of G6PDHs in Arabidopsis and barley corroborate the data presented. Moreover, the gene coding for the root P2-G6PDH isoform was fully sequenced; the biochemical properties of the corresponding protein were examined experimentally. The results are discussed in the light of the possible distinct roles and regulation of the different G6PDH isoforms during salt stress in barley roots.

  2. Allometric scaling of the maximum metabolic rate of mammals: oxygen transport from the lungs to the heart is a limiting step

    Directory of Open Access Journals (Sweden)

    Painter Page R

    2005-08-01

    Full Text Available Abstract Background The maximum metabolic rate (MMR of mammals is approximately proportional to M0.9, where M is the mammal's body weight. Therefore, MMR increases with body weight faster than does the basal metabolic rate (BMR, which is approximately proportional to M0.7. MMR is strongly associated with the capacity of the cardiovascular system to deliver blood to capillaries in the systemic circulation, but properties of this vascular system have not produced an explanation for the scaling of MMR. Results Here we focus on the pulmonary circulation where resistance to blood flow (impedance places a limit on the rate that blood can be pumped through the lungs before pulmonary edema occurs. The maximum pressure gradient that does not produce edema determines the maximum rate that blood can flow through the pulmonary veins without compromising the diffusing capacity of oxygen. We show that modeling the pulmonary venous tree as a fractal-like vascular network leads to a scaling equation for maximum cardiac output that predicts MMR as a function of M as well as the conventional power function aMb does and that least-squares regression estimates of the equation's slope-determining parameter correspond closely to the value of the parameter calculated directly from Murray's law. Conclusion The assumption that cardiac output at the MMR is limited by pulmonary capillary pressures that produce edema leads to a model that is in agreement with experimental measurements of MMR scaling, and the rate of blood flow in pulmonary veins may be rate-limiting for the pathway of oxygen.

  3. Rate limiting factors in trichloroethylene co-metabolic degradation by phenol-grown aerobic granules.

    Science.gov (United States)

    Zhang, Yi; Tay, Joo Hwa

    2014-04-01

    The potential of aerobic granular sludge in co-metabolic removal of recalcitrant substances was evaluated using trichloroethylene (TCE) as the model compound. Aerobic granules cultivated in a sequencing batch reactor with phenol as the growth substrate exhibited TCE and phenol degradation activities lower than previously reported values. Depletion of reducing energy and diffusion limitation within the granules were investigated as the possible rate limiting factors. Sodium formate and citrate were supplied to the granules in batch studies as external electron sources. No significant enhancing effect was observed on the instant TCE transformation rates, but 10 mM formate could improve the ultimate transformation capacity by 26 %. Possible diffusion barrier was studied by sieving the biomass into five size fractions, and determining their specific TCE and phenol degradation rates and capacities. Biomass in the larger size fractions generally showed lower activities. Large granules of >700 μm diameter exhibited only 22 % of the flocs' TCE transformation capacity and 35 % of its phenol dependent SOUR, indicating the possible occurrence of diffusion limitation in larger biomass. However, the highest specific TCE transformation rate was observed with the fraction that mostly consisted of small granules (150-300 μm), suggesting an optimal size range while applying aerobic granules in TCE co-metabolic removal.

  4. The Relation of Standard Metabolic Rate to Water Temperature and Body Weight of Schlegels Black Rockfish (Sebastodes Fuscescens)

    Institute of Scientific and Technical Information of China (English)

    马志敏; 孙耀; 张波; 唐启升

    2004-01-01

    Standard metabolic rates of Schlegels black rockfish with different body weights are determined in laboratory by using the flow-through respirometer at 11.2 ℃, 14.7 ℃, 18.0℃ and 23.6 ℃. The results indicate that the standard metabolic rates increase with the increase of body weight at different temperatures. Relationship between them could be described as Rs = a InW b. The mean of standard metabolic rate is significantly different among groups, but the b values are not. The standard metabolic rates of amended standard body weights decrease with the increase of temperature, and the mean of standard metabolic rate is also significantly different among groups when the standard body weights are 48.6 g, 147.9 g, and 243.1 g.Relationship between them could be described as Rsw = me-bT . The relations of standard metabolic rate ( Rs ) or relative metabolic rate ( Rs ) to body weight and temperature yield the following equations: Rs = 1.160 W0.752 e-9.494/7 and Rs1= 1.160 W0.254e-9.494/7.

  5. Quantifying metabolic rates in submarine hydrothermal vent chimneys: A reaction transport model

    Science.gov (United States)

    LaRowe, D.; Dale, A.; Aguilera, D.; Amend, J. P.; Regnier, P.

    2012-12-01

    The fluids emanating from active submarine hydrothermal vent chimneys provide a window into subseafloor processes and, through mixing with seawater, are responsible for steep thermal and compositional gradients that provide the energetic basis for diverse biological communities. Although several models have been developed to better understand the dynamic interplay of seawater, hydrothermal fluid, minerals and microorganisms inside chimney walls, none provide a fully integrated approach to quantifying the biogeochemistry of these hydrothermal systems. In an effort to remedy this, a fully coupled biogeochemical reaction transport model of a hydrothermal vent chimney has been developed that explicitly quantifies the rate of microbial catalysis while taking into account geochemical processes such as fluid flow, solute transport and oxidation-reduction reactions associated with fluid mixing as a function of temperature. Methanogenesis, hydrogen oxidation by oxygen and sulfate, sulfide oxidation by oxygen and methane oxidation by oxygen and sulfate are the metabolisms included in the reaction network. Model results indicate that microbial catalysis is fastest in the hottest habitable portion of the vent chimney except for methane oxidation by oxygen, which peaks near the seawater-side of the chimney at 20 nmol /cm^3 yr. The dominant metabolisms in the chimney are hydrogen oxidation by sulfate and oxygen and sulfide oxidation at peak rates 3200 , 300 and 900 nmol /cm^3 yr, respectively. The maximum rate of hydrogenotrophic methanogensis is just under 0.07 nmol /cm^3 yr, the slowest of the metabolisms considered. Due to thermodynamic inhibition, there is no anaerobic oxidation of methane by sulfate (AOM). The model developed here provides a quantitative approach to understanding the rates of biogeochemical transformations in hydrothermal systems and can be used to better understand the role of microbial activity in the deep subsurface.

  6. Metabolism

    Science.gov (United States)

    ... Are More Common in People With Type 1 Diabetes Metabolic Syndrome Your Child's Weight Healthy Eating Endocrine System Blood Test: Basic Metabolic Panel (BMP) Activity: Endocrine System Growth Disorders Diabetes Center Thyroid Disorders Your Endocrine System Movie: Endocrine ...

  7. Metabolism

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    2008255 Serum adiponectin level declines in the elderly with metabolic syndrome.WU Xiaoyan(吴晓琰),et al.Dept Geriatr,Huashan Hosp,Fudan UnivShanghai200040.Chin J Geriatr2008;27(3):164-167.Objective To investigate the correlation between ser-um adiponectin level and metabolic syndrome in the elderly·Methods Sixty-one subjects with metabolic syndrome and140age matched subjects without metabolic

  8. Physiological effects of bioceramic material: harvard step, resting metabolic rate and treadmill running assessments.

    Science.gov (United States)

    Leung, Ting-Kai; Kuo, Chia-Hua; Lee, Chi-Ming; Kan, Nai-Wen; Hou, Chien-Wen

    2013-12-31

    Previous biomolecular and animal studies have shown that a room-temperature far-infrared-rayemitting ceramic material (bioceramic) demonstrates physical-biological effects, including the normalization of psychologically induced stress-conditioned elevated heart rate in animals. In this clinical study, the Harvard step test, the resting metabolic rate (RMR) assessment and the treadmill running test were conducted to evaluate possible physiological effects of the bioceramic material in human patients. The analysis of heart rate variability (HRV) during the Harvard step test indicated that the bioceramic material significantly increased the high-frequency (HF) power spectrum. In addition, the results of RMR analysis suggest that the bioceramic material reduced oxygen consumption (VO2). Our results demonstrate that the bioceramic material has the tendency to stimulate parasympathetic responses, which may reduce resting energy expenditure and improve cardiorespiratory recovery following exercise.

  9. Is there a relationship between insect metabolic rate and mortality of mealworms Tenebrio molitor L. after insecticide exposure?

    Directory of Open Access Journals (Sweden)

    Justyna MALISZEWSKA

    2016-09-01

    Full Text Available Pesticides are known to affect insects metabolic rate and CO2 release patterns. In the presented paper metabolic rate and mortality of mealworms Tenebrio molitor L. exposed to four different insecticides was evaluated, to find out whether there is a relationship between mealworms sensitivity to pesticides and their metabolic rate. Tenebrio molitor mortality was determined after intoxication with pyrethroid, oxadiazine, neonicotinoid and organophosphate. Metabolic rate before and after intoxication with insecticides was also determined. The highest CO2 production and mortality rate was observed after mealworms exposition to neonicotinoid insecticide. The results suggest that high CO2 release after intoxication is adequate to the intensity of the non-specific action of the xenobiotic (e.g. hyperactivity of neuromuscular system, rather than the intensity of detoxification processes, and it is correlated with mealworms mortality.

  10. Effective Presentation of Metabolic Rate Information for Lunar Extravehicular Activity (EVA)

    Science.gov (United States)

    Mackin, Michael A.; Gonia, Philip; Lombay-Gonzalez, Jose

    2010-01-01

    During human exploration of the lunar surface, a suited crewmember needs effective and accurate information about consumable levels remaining in their life support system. The information must be presented in a manner that supports real-time consumable monitoring and route planning. Since consumable usage is closely tied to metabolic rate, the lunar suit must estimate metabolic rate from life support sensors, such as oxygen tank pressures, carbon dioxide partial pressure, and cooling water inlet and outlet temperatures. To provide adequate warnings that account for traverse time for a crewmember to return to a safe haven, accurate forecasts of consumable depletion rates are required. The forecasts must be presented to the crewmember in a straightforward, effective manner. In order to evaluate methods for displaying consumable forecasts, a desktop-based simulation of a lunar Extravehicular Activity (EVA) has been developed for the Constellation lunar suite s life-support system. The program was used to compare the effectiveness of several different data presentation methods.

  11. Effects of nutritional status on metabolic rate, exercise and recovery in a freshwater fish

    Energy Technology Data Exchange (ETDEWEB)

    Gingerich, Andrew J.; Philipp, D. P.; Suski, C. D.

    2010-11-20

    The influence of feeding on swimming performance and exercise recovery in fish is poorly understood. Examining swimming behavior and physiological status following periods of feeding and fasting is important because wild fish often face periods of starvation. In the current study, researchers force fed and fasted groups of largemouth bass (Micropterus salmoides) of similar sizes for a period of 16 days. Following this feeding and fasting period, fish were exercised for 60 s and monitored for swimming performance and physiological recovery. Resting metabolic rates were also determined. Fasted fish lost an average of 16 g (nearly 12%) of body mass, while force fed fish maintained body mass. Force fed fish swam 28% further and required nearly 14 s longer to tire during exercise. However, only some physiological conditions differed between feeding groups. Resting muscle glycogen concentrations was twofold greater in force fed fish, at rest and throughout recovery, although it decreased in both feeding treatments following exercise. Liver mass was nearly three times greater in force fed fish, and fasted fish had an average of 65% more cortisol throughout recovery. Similar recovery rates of most physiological responses were observed despite force fed fish having a metabolic rate 75% greater than fasted fish. Results are discussed as they relate to largemouth bass starvation in wild systems and how these physiological differences might be important in an evolutionary context.

  12. Effects of nutritional status on metabolic rate, exercise and recovery in a freshwater fish.

    Science.gov (United States)

    Gingerich, Andrew James; Philipp, David P; Suski, Cory D

    2010-03-01

    The influence of feeding on swimming performance and exercise recovery in fish is poorly understood. Examining swimming behavior and physiological status following periods of feeding and fasting is important because wild fish often face periods of starvation. In the current study, researchers force fed and fasted groups of largemouth bass (Micropterus salmoides) of similar sizes for a period of 16 days. Following this feeding and fasting period, fish were exercised for 60 s and monitored for swimming performance and physiological recovery. Resting metabolic rates were also determined. Fasted fish lost an average of 16 g (nearly 12%) of body mass, while force fed fish maintained body mass. Force fed fish swam 28% further and required nearly 14 s longer to tire during exercise. However, only some physiological conditions differed between feeding groups. Resting muscle glycogen concentrations was twofold greater in force fed fish, at rest and throughout recovery, although it decreased in both feeding treatments following exercise. Liver mass was nearly three times greater in force fed fish, and fasted fish had an average of 65% more cortisol throughout recovery. Similar recovery rates of most physiological responses were observed despite force fed fish having a metabolic rate 75% greater than fasted fish. Results are discussed as they relate to largemouth bass starvation in wild systems and how these physiological differences might be important in an evolutionary context.

  13. Effect of copper nanoparticles and copper sulphate on metabolic rate and development of broiler embryos

    DEFF Research Database (Denmark)

    Scott, Abdullah Talal Abudllah; Vadalasetty, Krishna Prasad; Sawosz, E.

    2016-01-01

    Copper (Cu) is regularly used as a growth promoter in poultry production. However, it has been demonstrated that the content of Cu inside eggs might not be sufficient to support the embryonic development. It is possible to supply the embryo with extra nutrients by in-ovo administration. Recently......, it has been shown that in-ovo administration of copper nanoparticles (Cu-NP) and copper sulphate (CuSO4) remarkably improved the body weights of growing chickens. Thus, the objective of the present experiment was to elucidate the potential effects of Cu-NP and CuSO4 on the metabolic rate (oxygen...

  14. Gestation length, metabolic rate, and body and brain weights in primates: epigenetic effects.

    Science.gov (United States)

    Little, B B

    1989-10-01

    The relationship of brain and body weights can be expressed in log-log regression: log (brain weight) = log (A) + B log (body weight). To investigate further the weights' similarity, gestation length and brain and body weights were determined from the literature for 46 primate genera. The results of allometric and path regression analyses suggest that the relationship between brain and body weights may not be mainly pleiotropic in the order Primates. The correlation between brain and body weights appears to be due to epigenetic factors in hyperplastic growth related to time constraint by gestation length and to energy utilization limitations imposed by metabolic rate.

  15. Basal Reinforced Piled Embankments

    NARCIS (Netherlands)

    Van Eekelen, S.J.M.

    2015-01-01

    A basal reinforced piled embankment consists of a reinforced embankment on a pile foundation. The reinforcement consists of one or more horizontal layers of geosynthetic reinforcement (GR) installed at the base of the embankment. The design of the GR is the subject of this thesis. A basal reinforce

  16. Steelhead trout Oncorhynchus mykiss metabolic rate is affected by dietary Aloe vera inclusion but not by mounting an immune response against formalin-killed Aeromonas salmonicida.

    Science.gov (United States)

    Zanuzzo, F S; Urbinati, E C; Nash, G W; Gamperl, A K

    2015-07-01

    The oxygen consumption (MO2) of two groups of 10° C acclimated steelhead trout Oncorhynchus mykiss was measured for 72 h after they were given a 100 µl kg(-1) intraperitoneal injection of formalin-killed Aeromonas salmonicida (ASAL) or phosphate-buffered saline (PBS). In addition, plasma cortisol levels were measured in fish from both groups prior to, and 1 and 3 h after, they were given a 30 s net stress. The first group was fed an unaltered commercial diet for 4 weeks, whereas the second group was fed the same diet but with 0·5% (5 g kg(-1) ) Aloe vera powder added; A. vera has potential as an immunostimulant for use in aquaculture, but its effects on basal and acute phase response (APR)-related metabolic expenditures and stress physiology, are unknown. Injection of ASAL v. PBS had no measurable effect on the MO2 of O. mykiss indicating that the APR in this species is not associated with any net increase in energy expenditure. In contrast, incorporating 0·5% A. vera powder into the feed decreased routine metabolic rate by c. 8% in both injection groups and standard metabolic rate in the ASAL-injected group (by c. 4 mg O2 kg(-1) h(-1) ; 5%). Aloe vera fed fish had resting cortisol levels that were approximately half of those in fish on the commercial diet (c. 2·5 v. 5·0 ng ml(-1) ), but neither this difference nor those post-stress reached statistical significance (P > 0·05).

  17. Intrinsic vs. extrinsic influences on life history expression: metabolism and parentally induced temperature influences on embryo development rate

    Science.gov (United States)

    Martin, Thomas E.; Ton, Riccardo; Nikilson, Alina

    2013-01-01

    Intrinsic processes are assumed to underlie life history expression and trade-offs, but extrinsic inputs are theorised to shift trait expression and mask trade-offs within species. Here, we explore application of this theory across species. We do this based on parentally induced embryo temperature as an extrinsic input, and mass-specific embryo metabolism as an intrinsic process, underlying embryonic development rate. We found that embryonic metabolism followed intrinsic allometry rules among 49 songbird species from temperate and tropical sites. Extrinsic inputs via parentally induced temperatures explained the majority of variation in development rates and masked a relationship with metabolism; metabolism explained a minor proportion of the variation in development rates among species, and only after accounting for temperature effects. We discuss evidence that temperature further obscures the expected interspecific trade-off between development rate and offspring quality. These results demonstrate the importance of considering extrinsic inputs to trait expression and trade-offs across species.

  18. Association between the glomerular filtration rate of renal dysfunction and metabolic syndrome: an age-stratified analysis

    Institute of Scientific and Technical Information of China (English)

    宋慧

    2014-01-01

    Objective To explore the relationship between the renal dysfunction rate and metabolic syndrome(MS),stratified by age.Methods People took part in physical check-up in a certain tertiary hospital from March 2010to September 2012,were enrolled in this study.Estimated glomerular filtration rate(e GFR),—a renal dysfunction indicator,was calculated by modified MDRD

  19. Standard metabolic rate is associated with gestation duration, but not clutch size, in speckled cockroaches Nauphoeta cinerea

    Directory of Open Access Journals (Sweden)

    Natalie G. Schimpf

    2012-09-01

    Metabolic rate varies significantly between individuals, and these differences persist even when the wide range of biotic and abiotic factors that influence metabolism are accounted for. It is important to understand the life history implications of variation in metabolic rate, but they remain poorly characterised despite a growing body of work examining relationships between metabolism and a range of traits. In the present study we used laboratory-bred families (one sire to three dams of Nauphoeta cinerea (Olivier (speckled cockroaches to examine the relationship between standard metabolic rate (SMR and reproductive performance (number of offspring and gestation duration. We show that SMR is negatively associated with female gestation duration. Age at mating is negatively associated with gestation duration for females, and mass is negatively associated with the average gestation duration of the females a male was mated with. In addition to the results in the current literature, the results from the present study suggest that the association between metabolism and life history is more complex than simple relationships between metabolism and various fitness traits. Future work should consider longitudinal, ontogenetic as well as selective and quantitative genetic breeding approaches to fully examine the associations between metabolism and fitness.

  20. The emerging roles of microRNAs in the molecular responses of metabolic rate depression

    Institute of Scientific and Technical Information of China (English)

    Kyle K. Biggar; Kenneth B. Storey

    2011-01-01

    Metabolic rate depression is an important survival strategy for many animal species and a common element of hibernation, torpor,estivation, anoxia and diapause. Studies of the molecular mechanisms that regulate reversible transitions to and from hypometabolic states have identified principles of regulatory control. These control mechanisms are conserved among biologically diverse organisms and include the coordinated reduction of specific groups of key regulatory enzymes or proteins in the cell, a process likely driven by microRNA target repression/degradation. The present review focuses on a growing area of research in hypometabolism and mechanisms involving the rapid and reversible control of translation facilitated by microRNAs. The analysis draws primarily from current research on three animal models: hibernating mammals, anoxic turtles and freeze-tolerant frogs (with selected examples from multiple other sources). Here, we demonstrate a link between metabolic rate depression, a well-documented response to periods of environmental stress, and microRNA expression. Microarray-based expression profiles and PCR-driven studies have revealed that specific microRNAs are induced in response to environmental stress. Selected members of this group decrease pro-apeptotic signaling,reduce muscle wasting and reduce protein translation, whereas other members contribute to cell cycle arrest and mitogen-activated protein kinase signaling. Many of the same microRNAs are frequently deregulated in numerous disease pathologies and, hence, the hypometabolism model could provide a novel approach for the treatment of stroke and heart attack in humans.

  1. Comparative metabolic rates of common western North Atlantic Ocean sciaenid fishes.

    Science.gov (United States)

    Horodysky, A Z; Brill, R W; Bushnell, P G; Musick, J A; Latour, R J

    2011-07-01

    The resting metabolic rates (R(R)) of western North Atlantic Ocean sciaenids, such as Atlantic croaker Micropogonias undulatus, spot Leiostomus xanthurus and kingfishes Menticirrhus spp., as well as the active metabolic rates (R(A)) of M. undulatus and L. xanthurus were investigated to facilitate inter and intraspecific comparisons of their energetic ecology. The R(R) of M. undulatus and L. xanthurus were typical for fishes with similar lifestyles. The R(R) of Menticirrhus spp. were elevated relative to those of M. undulatus and L. xanthurus, but below those of high-energy-demand species such as tunas Thunnus spp. and dolphinfish Coryphaena hippurus. Repeated-measures non-linear mixed-effects models were applied to account for within-individual autocorrelation and corrected for non-constant variance typical of noisy R(A) data sets. Repeated-measures models incorporating autoregressive first-order [AR(1)] and autoregressive moving average (ARMA) covariances provided significantly superior fits, more precise parameter estimates (i.e. reduced s.e.) and y-intercept estimates that more closely approximated measured R(R) for M. undulatus and L. xanthurus than standard least-squares regression procedures.

  2. Best practice methods to apply to measurement of resting metabolic rate in adults: a systematic review.

    Science.gov (United States)

    Compher, Charlene; Frankenfield, David; Keim, Nancy; Roth-Yousey, Lori

    2006-06-01

    Several factors may alter apparent resting metabolic rate (RMR) during measurement with indirect calorimetry. Likewise, numerous indirect calorimetry measurement protocols have been developed over the years, and the methodology employed could influence test results. As part of a larger project to determine the role of indirect calorimetry in clinical practice, a systematic review of the literature was undertaken to determine the ideal subject condition and test methodology for obtaining reliable measurement of RMR with indirect calorimetry. Food, ethanol, caffeine, and nicotine affect RMR for a variable number of hours after consumption; therefore, intake of these items must be controlled before measurement. Activities of daily living increase metabolic rate, but a short rest (calorimetry should refrain from eating, consuming ethanol and nicotine, smoking, and engaging in physical activity for varying times before measurement. The test site should be physically comfortable and the individual should have 10 to 20 minutes to rest before measurement commences. A 10-minute test duration with the first 5 minutes discarded and the remaining 5 minutes having a coefficient of variation of <10% will give an accurate measure of RMR.

  3. Muscle energy stores and stroke rates of emperor penguins: implications for muscle metabolism and dive performance.

    Science.gov (United States)

    Williams, Cassondra L; Sato, Katsufumi; Shiomi, Kozue; Ponganis, Paul J

    2012-01-01

    In diving birds and mammals, bradycardia and peripheral vasoconstriction potentially isolate muscle from the circulation. During complete ischemia, ATP production is dependent on the size of the myoglobin oxygen (O(2)) store and the concentrations of phosphocreatine (PCr) and glycogen (Gly). Therefore, we measured PCr and Gly concentrations in the primary underwater locomotory muscle of emperor penguin and modeled the depletion of muscle O(2) and those energy stores under conditions of complete ischemia and a previously determined muscle metabolic rate. We also analyzed stroke rate to assess muscle workload variation during dives and evaluate potential limitations on the model. Measured PCr and Gly concentrations, 20.8 and 54.6 mmol kg(-1), respectively, were similar to published values for nondiving animals. The model demonstrated that PCr and Gly provide a large anaerobic energy store, even for dives longer than 20 min. Stroke rate varied throughout the dive profile, indicating muscle workload was not constant during dives as was assumed in the model. The stroke rate during the first 30 s of dives increased with increased dive depth. In extremely long dives, lower overall stroke rates were observed. Although O(2) consumption and energy store depletion may vary during dives, the model demonstrated that PCr and Gly, even at concentrations typical of terrestrial birds and mammals, are a significant anaerobic energy store and can play an important role in the emperor penguin's ability to perform long dives.

  4. Nonlinear temperature effects on multifractal complexity of metabolic rate of mice

    Science.gov (United States)

    Bogdanovich, Jose M.; Bozinovic, Francisco

    2016-01-01

    Complex physiological dynamics have been argued to be a signature of healthy physiological function. Here we test whether the complexity of metabolic rate fluctuations in small endotherms decreases with lower environmental temperatures. To do so, we examine the multifractal temporal scaling properties of the rate of change in oxygen consumption r(VO2), in the laboratory mouse Mus musculus, assessing their long range correlation properties across seven different environmental temperatures, ranging from 0 °C to 30 °C. To do so, we applied multifractal detrended fluctuation analysis (MF-DFA), finding that r(VO2) fluctuations show two scaling regimes. For small time scales below the crossover time (approximately 102 s), either monofractal or weak multifractal dynamics are observed depending on whether Ta  15 °C respectively. For larger time scales, r(VO2) fluctuations are characterized by an asymptotic scaling exponent that indicates multifractal anti-persistent or uncorrelated dynamics. For both scaling regimes, a generalization of the multiplicative cascade model provides very good fits for the Renyi exponents τ(q), showing that the infinite number of exponents h(q) can be described by only two independent parameters, a and b. We also show that the long-range correlation structure of r(VO2) time series differs from randomly shuffled series, and may not be explained as an artifact of stochastic sampling of a linear frequency spectrum. These results show that metabolic rate dynamics in a well studied micro-endotherm are consistent with a highly non-linear feedback control system.

  5. Nonlinear temperature effects on multifractal complexity of metabolic rate of mice

    Directory of Open Access Journals (Sweden)

    Fabio A. Labra

    2016-10-01

    Full Text Available Complex physiological dynamics have been argued to be a signature of healthy physiological function. Here we test whether the complexity of metabolic rate fluctuations in small endotherms decreases with lower environmental temperatures. To do so, we examine the multifractal temporal scaling properties of the rate of change in oxygen consumption r(VO2, in the laboratory mouse Mus musculus, assessing their long range correlation properties across seven different environmental temperatures, ranging from 0 °C to 30 °C. To do so, we applied multifractal detrended fluctuation analysis (MF-DFA, finding that r(VO2 fluctuations show two scaling regimes. For small time scales below the crossover time (approximately 102 s, either monofractal or weak multifractal dynamics are observed depending on whether Ta  15 °C respectively. For larger time scales, r(VO2 fluctuations are characterized by an asymptotic scaling exponent that indicates multifractal anti-persistent or uncorrelated dynamics. For both scaling regimes, a generalization of the multiplicative cascade model provides very good fits for the Renyi exponents τ(q, showing that the infinite number of exponents h(q can be described by only two independent parameters, a and b. We also show that the long-range correlation structure of r(VO2 time series differs from randomly shuffled series, and may not be explained as an artifact of stochastic sampling of a linear frequency spectrum. These results show that metabolic rate dynamics in a well studied micro-endotherm are consistent with a highly non-linear feedback control system.

  6. The rate of metabolism as a factor determining longevity of the Saccharomyces cerevisiae yeast.

    Science.gov (United States)

    Molon, Mateusz; Szajwaj, Monika; Tchorzewski, Marek; Skoczowski, Andrzej; Niewiadomska, Ewa; Zadrag-Tecza, Renata

    2016-02-01

    Despite many controversies, the yeast Saccharomyces cerevisiae continues to be used as a model organism for the study of aging. Numerous theories and hypotheses have been created for several decades, yet basic mechanisms of aging have remained unclear. Therefore, the principal aim of this work is to propose a possible mechanism leading to increased longevity in yeast. In this paper, we suggest for the first time that there is a link between decreased metabolic activity, fertility and longevity expressed as time of life in yeast. Determination of reproductive potential and total lifespan with the use of fob1Δ and sfp1Δ mutants allows us to compare the "longevity" presented as the number of produced daughters with the longevity expressed as the time of life. The results of analyses presented in this paper suggest the need for a change in the definition of longevity of yeast by taking into consideration the time parameter. The mutants that have been described as "long-lived" in the literature, such as the fob1Δ mutant, have an increased reproductive potential but live no longer than their standard counterparts. On the other hand, the sfp1Δ mutant and the wild-type strain produce a similar number of daughter cells, but the former lives much longer. Our results demonstrate a correlation between the decreased efficiency of the translational apparatus and the longevity of the sfp1Δ mutant. We suggest that a possible factor regulating the lifespan is the rate of cell metabolism. To measure the basic metabolism of the yeast cells, we used the isothermal microcalorimetry method. In the case of sfp1Δ, the flow of energy, ATP concentration, polysome profile and translational fitness are significantly lower in comparison with the wild-type strain and the fob1Δ mutant.

  7. Molecular analysis of the metabolic rates of discrete subsurface populations of sulfate reducers

    Energy Technology Data Exchange (ETDEWEB)

    Miletto, M.; Williams, K.H.; N' Guessan, A.L.; Lovley, D.R.

    2011-04-01

    Elucidating the in situ metabolic activity of phylogenetically diverse populations of sulfate-reducing microorganisms that populate anoxic sedimentary environments is key to understanding subsurface ecology. Previous pure culture studies have demonstrated that transcript abundance of dissimilatory (bi)sulfite reductase genes is correlated with the sulfate reducing activity of individual cells. To evaluate whether expression of these genes was diagnostic for subsurface communities, dissimilatory (bi)sulfite reductase gene transcript abundance in phylogenetically distinct sulfate-reducing populations was quantified during a field experiment in which acetate was added to uranium-contaminated groundwater. Analysis of dsrAB sequences prior to the addition of acetate indicated that Desulfobacteraceae, Desulfobulbaceae, and Syntrophaceae-related sulfate reducers were the most abundant. Quantifying dsrB transcripts of the individual populations suggested that Desulfobacteraceae initially had higher dsrB transcripts per cell than Desulfobulbaceae or Syntrophaceae populations, and that the activity of Desulfobacteraceae increased further when the metabolism of dissimilatory metal reducers competing for the added acetate declined. In contrast, dsrB transcript abundance in Desulfobulbaceae and Syntrophaceae remained relatively constant, suggesting a lack of stimulation by added acetate. The indication of higher sulfate-reducing activity in the Desulfobacteraceae was consistent with the finding that Desulfobacteraceae became the predominant component of the sulfate-reducing community. Discontinuing acetate additions resulted in a decline in dsrB transcript abundance in the Desulfobacteraceae. These results suggest that monitoring transcripts of dissimilatory (bi)sulfite reductase genes in distinct populations of sulfate reducers can provide insight into the relative rates of metabolism of different components of the sulfate-reducing community and their ability to respond to

  8. Predicting metabolic rate during level and uphill outdoor walking using a low-cost GPS receiver.

    Science.gov (United States)

    de Müllenheim, Pierre-Yves; Dumond, Rémy; Gernigon, Marie; Mahé, Guillaume; Lavenu, Audrey; Bickert, Sandrine; Prioux, Jacques; Noury-Desvaux, Bénédicte; Le Faucheur, Alexis

    2016-08-01

    The objective of this study was to assess the accuracy of using speed and grade data obtained from a low-cost global positioning system (GPS) receiver to estimate metabolic rate (MR) during level and uphill outdoor walking. Thirty young, healthy adults performed randomized outdoor walking for 6-min periods at 2.0, 3.5, and 5.0 km/h and on three different grades: 1) level walking, 2) uphill walking on a 3.7% mean grade, and 3) uphill walking on a 10.8% mean grade. The reference MR [metabolic equivalents (METs) and oxygen uptake (V̇o2)] values were obtained using a portable metabolic system. The speed and grade were obtained using a low-cost GPS receiver (1-Hz recording). The GPS grade (Δ altitude/distance walked) was calculated using both uncorrected GPS altitude data and GPS altitude data corrected with map projection software. The accuracy of predictions using reference speed and grade (actual[SPEED/GRADE]) data was high [R(2) = 0.85, root-mean-square error (RMSE) = 0.68 MET]. The accuracy decreased when GPS speed and uncorrected grade (GPS[UNCORRECTED]) data were used, although it remained substantial (R(2) = 0.66, RMSE = 1.00 MET). The accuracy was greatly improved when the GPS speed and corrected grade (GPS[CORRECTED]) data were used (R(2) = 0.82, RMSE = 0.79 MET). Published predictive equations for walking MR were also cross-validated using actual or GPS speed and grade data when appropriate. The prediction accuracy was very close when either actual[SPEED/GRADE] values or GPS[CORRECTED] values (for level and uphill combined) or GPS speed values (for level walking only) were used. These results offer promising research and clinical applications related to the assessment of energy expenditure during free-living walking.

  9. Effects of Time-Release Caffeine Containing Supplement on Metabolic Rate, Glycerol Concentration and Performance

    Directory of Open Access Journals (Sweden)

    Adam M. Gonzalez, Jay R. Hoffman, Adam J. Wells, Gerald T. Mangine, Jeremy R. Townsend, Adam R. Jajtner, Ran Wang, Amelia A. Miramonti, Gabriel J. Pruna, Michael B. LaMonica, Jonathan D. Bohner, Mattan W. Hoffman, Leonardo P. Oliveira, David H. Fukuda, Maren S. Fragala, Jeffrey R. Stout

    2015-06-01

    Full Text Available This study compared caffeine pharmacokinetics, glycerol concentrations, metabolic rate, and performance measures following ingestion of a time-release caffeine containing supplement (TR-CAF versus a regular caffeine capsule (CAF and a placebo (PL. Following a double-blind, placebo-controlled, randomized, cross-over design, ten males (25.9 ± 3.2 y who regularly consume caffeine ingested capsules containing either TR-CAF, CAF, or PL. Blood draws and performance measures occurred at every hour over an 8-hour period. Plasma caffeine concentrations were significantly greater (p < 0.05 in CAF compared to TR-CAF during hours 2-5 and significantly greater (p = 0.042 in TR-CAF compared to CAF at hour 8. There were no significant differences between trials in glycerol concentrations (p = 0.86 or metabolic measures (p = 0.17-0.91. Physical reaction time was significantly improved for CAF at hour 5 (p=0.01 compared to PL. Average upper body reaction time was significantly improved for CAF and TR-CAF during hours 1-4 (p = 0.04 and p = 0.01, respectively and over the 8-hour period (p = 0.04 and p = 0.001, respectively compared to PL. Average upper body reaction time was also significantly improved for TR-CAF compared to PL during hours 5-8 (p = 0.004. TR-CAF and CAF showed distinct pharmacokinetics yielding modest effects on reaction time, yet did not alter glycerol concentration, metabolic measures, or other performance measures.

  10. Biphasic effect of melanocortin agonists on metabolic rate and body temperature.

    Science.gov (United States)

    Lute, Beth; Jou, William; Lateef, Dalya M; Goldgof, Margalit; Xiao, Cuiying; Piñol, Ramón A; Kravitz, Alexxai V; Miller, Nicole R; Huang, Yuning George; Girardet, Clemence; Butler, Andrew A; Gavrilova, Oksana; Reitman, Marc L

    2014-08-01

    The melanocortin system regulates metabolic homeostasis and inflammation. Melanocortin agonists have contradictorily been reported to both increase and decrease metabolic rate and body temperature. We find two distinct physiologic responses occurring at similar doses. Intraperitoneal administration of the nonselective melanocortin agonist MTII causes a melanocortin-4 receptor (Mc4r)-mediated hypermetabolism/hyperthermia. This is preceded by a profound, transient hypometabolism/hypothermia that is preserved in mice lacking any one of Mc1r, Mc3r, Mc4r, or Mc5r. Three other melanocortin agonists also caused hypothermia, which is actively achieved via seeking a cool environment, vasodilation, and inhibition of brown adipose tissue thermogenesis. These results suggest that the hypometabolic/hypothermic effect of MTII is not due to a failure of thermoregulation. The hypometabolism/hypothermia was prevented by dopamine antagonists, and MTII selectively activated arcuate nucleus dopaminergic neurons, suggesting that these neurons may contribute to the hypometabolism/hypothermia. We propose that the hypometabolism/hypothermia is a regulated response, potentially beneficial during extreme physiologic stress.

  11. Association between serum uric acid and different states of glucose metabolism and glomerular filtration rate

    Institute of Scientific and Technical Information of China (English)

    CAI Xiao-ling; HAN Xue-yao; JI Li-nong

    2010-01-01

    Background Recently, it has been suggested that the serum uric acid (SUA) level decreased in diabetic patients. The aim of this study was to explore the association between SUA level and different state of glucose metabolism and glomerular filtration rate (GFR) reflected by the simplified Modification of Diet in Renal Disease (MDRD) equation and to test the hypothesis that high MDRD is one of the determinants of SUA level.Methods This cross-sectional study included 2373 subjects in Beijing who underwent a 75 g oral glucose tolerance test (OGTT) for screening of diabetes. According to the states of glucose metabolism, they were divided into normal glucose tolerance, impaired glucose regulation and diabetes.Results Multiple stepwise linear regression analysis showed that adjusted by gender, SUA was positively correlated with body mass index (BMI), waist/hippo ratio, systolic blood pressure (SBP) and triglyceride, meanwhile negatively correlated with age, hemoglobin A1c, fasting insulin and MDRD. There was an increasing trend in SUA concentration and a decreasing trend in MDRD when the levels of fasting plasma glucose (FPG) increased from low to high up to the FPG level of 8.0 mmol/L; thereafter, the SUA concentration started to decrease with further increases in FPG levels, and the MDRD started to increase with further increases in FPG levels.Conclusion This study confirmed the previous finding that SUA decreased in diabetes and provided the supporting evidence that the increased MDRD might contribute to the fall of SUA.

  12. Autonomic control of heart rate by metabolically sensitive skeletal muscle afferents in humans

    DEFF Research Database (Denmark)

    Fisher, James P; Seifert, Thomas; Hartwich, Doreen

    2010-01-01

    Isolated activation of metabolically sensitive skeletal muscle afferents (muscle metaboreflex) using post-exercise ischaemia (PEI) following handgrip partially maintains exercise-induced increases in arterial blood pressure (BP) and muscle sympathetic nerve activity (SNA), while heart rate (HR......) declines towards resting values. Although masking of metaboreflex-mediated increases in cardiac SNA by parasympathetic reactivation during PEI has been suggested, this has not been directly tested in humans. In nine male subjects (23 +/- 5 years) the muscle metaboreflex was activated by PEI following...... moderate (PEI-M) and high (PEI-H) intensity isometric handgrip performed at 25% and 40% maximum voluntary contraction, under control (no drug), parasympathetic blockade (glycopyrrolate) and beta-adrenergic blockade (metoprolol or propranalol) conditions, while beat-to-beat HR and BP were continuously...

  13. Metabolic control analysis of biochemical pathways based on a thermokinetic description of reaction rates

    DEFF Research Database (Denmark)

    Nielsen, Jens Bredal

    1997-01-01

    Metabolic control analysis is a powerful technique for the evaluation of flux control within biochemical pathways. Its foundation is the elasticity coefficients and the flux control coefficients (FCCs). On the basis of a thermokinetic description of reaction rates it is here shown...... affinity. This parameter can often be determined from experiments in vitro. The methodology is applicable only to the analysis of simple two-step pathways, but in many cases larger pathways can be lumped into two overall conversions. In cases where this cannot be done it is necessary to apply an extension...... be much more widely applied, although it was originally based on linearized kinetics. The methodology of determining elasticity coefficients directly from pool levels is illustrated with an analysis of the first two steps of the biosynthetic pathway of penicillin. The results compare well with previous...

  14. THE RATE OF METABOLIC SYNDROME AND COMORBIDITIES IN PATIENTS WITH GOUT: DATA OF A MULTICENTER TRIAL

    Directory of Open Access Journals (Sweden)

    V G Barskova

    2012-01-01

    Full Text Available Objective: to study the rate of metabolic syndrome (MS and its components among gout patients in different regions of the Russian Federation. Subjects and methods. This cross-sectional multicenter study enrolled 2277 gout patients, including 1963 (86.2% men and 314 (13.8% women, from 12 independent medical centers in different regions of the Russian Federation. The patients over 18 years of age who met the classification criteria for gout, elaborated by S. Wallace et al., were included. The diagnosis of MS was established on the basis of Adult Treatment Panel III (ATP III criteria. The presence of MS, its individual components and comorbidities were recorded. Results. The total rate of MS in the patients with gout was 57%; however, it varied substantially (from 15 to 77% in different centers. Among the comorbidities, arterial hypertension was most common (in three fourths of the patients, coronary heart disease (CHD and type 2 diabetes mellitus were less common (43 and 25%, respectively; 15% of the patients had sustained myocardial infarction, renal and cardiac failure was also observed in 15%. In the gout patients, MS was associated with the presence of CHD. Conclusion. The patients with gout were observed to have a high rate of MS (57%, its components, and cardiovascular diseases. The findings suggest that there is a relationship between the presence of MS and the development of CHD.

  15. Contribution of mitochondrial proton leak to skeletal muscle respiration and to standard metabolic rate.

    Science.gov (United States)

    Rolfe, D F; Brand, M D

    1996-10-01

    We have tested the hypothesis that the leak of protons across the mitochondrial inner membrane (proton leak) is a significant contributor to standard metabolic rate (SMR). We found that proton leak accounts for around one-half of the resting respiration rate of perfused rat skeletal muscle. Proton leak is known to make a significant (26%) contribution to the resting respiration rate of isolated rat hepatocytes (M. D. Brand, L.-F. Chien, E. K. Ainscow, D. F. S. Rolfe, and R. K. Porter. Biochim. Biophys. Acta 1187: 132-139, 1994). If the importance of proton leak in these isolated and perfused systems is similar to its importance in vivo, then using literature values for the contribution of liver and skeletal muscle to SMR, we can calculate that proton leak in liver and skeletal muscle alone accounts for 11-26% (mean 20%) of the SMR of the rat. If proton leak activity in the other tissues of the rat is similar to that in liver cells, then the contribution of proton leak to rat SMR would be 16-31% (mean 25%).

  16. The interplay between aerobic metabolism and antipredator performance: vigilance is related to recovery rate after exercise.

    Science.gov (United States)

    Killen, Shaun S; Reid, Donald; Marras, Stefano; Domenici, Paolo

    2015-01-01

    When attacked by a predator, fish respond with a sudden fast-start motion away from the threat. Although this anaerobically-powered swimming necessitates a recovery phase which is fueled aerobically, little is known about links between escape performance and aerobic traits such as aerobic scope (AS) or recovery time after exhaustive exercise. Slower recovery ability or a reduced AS could make some individuals less likely to engage in a fast-start response or display reduced performance. Conversely, increased vigilance in some individuals could permit faster responses to an attack but also increase energy demand and prolong recovery after anaerobic exercise. We examined how AS and the ability to recover from anaerobic exercise relates to differences in fast-start escape performance in juvenile golden gray mullet at different acclimation temperatures. Individuals were acclimated to either 18, 22, or 26°C, then measured for standard and maximal metabolic rates and AS using intermittent flow respirometry. Anaerobic capacity and the time taken to recover after exercise were also assessed. Each fish was also filmed during a simulated attack to determine response latency, maximum speed and acceleration, and turning rate displayed during the escape response. Across temperatures, individuals with shorter response latencies during a simulated attack are those with the longest recovery time after exhaustive anaerobic exercise. Because a short response latency implies high preparedness to escape, these results highlight the trade-off between the increased vigilance and metabolic demand, which leads to longer recovery times in fast reactors. These results improve our understanding of the intrinsic physiological traits that generate inter-individual variability in escape ability, and emphasize that a full appreciation of trade-offs associated with predator avoidance and energy balance must include energetic costs associated with vigilance and recovery from anaerobic exercise.

  17. The interplay between aerobic metabolism and antipredator performance: vigilance is related to recovery rate after exercise

    Directory of Open Access Journals (Sweden)

    Shaun Steven Killen

    2015-04-01

    Full Text Available When attacked by a predator, fish respond with a sudden fast-start motion away from the threat. Although this anaerobically-powered swimming necessitates a recovery phase which is fuelled aerobically, little is known about links between escape performance and aerobic traits such as aerobic scope or recovery time after exhaustive exercise. Slower recovery ability or a reduced aerobic scope could make some individuals less likely to engage in a fast-start response or display reduced performance. Conversely, increased vigilance in some individuals could permit faster responses to an attack but also increase energy demand and prolong recovery after anaerobic exercise. We examined how aerobic scope and the ability to recover from anaerobic exercise relates to differences in fast-start escape performance in juvenile golden grey mullet at different acclimation temperatures. Individuals were acclimated to either 18, 22, or 26oC, then measured for standard and maximal metabolic rates and aerobic scope using intermittent flow respirometry. Anaerobic capacity and the time taken to recover after exercise were also assessed. Each fish was also filmed during a simulated attack to determine response latency, maximum speed and acceleration, and turning rate displayed during the escape response. Across temperatures, individuals with shorter response latencies during a simulated attack are those with the longest recovery time after exhaustive anaerobic exercise. Because a short response latency implies high preparedness to escape, these results highlight the trade-off between the increased vigilance and metabolic demand, which leads to longer recovery times in fast reactors. These results improve our understanding of the intrinsic physiological traits that generate inter-individual variability in escape ability, and emphasise that a full appreciation of trade-offs associated with predator avoidance and energy balance must include energetic costs associated with

  18. Gamma distribution model describes maturational curves for delta wave amplitude, cortical metabolic rate and synaptic density.

    Science.gov (United States)

    Feinberg, I; Thode, H C; Chugani, H T; March, J D

    1990-01-23

    We analyzed the available ontogenetic data (birth to 30 years of age) for: amplitude of delta EEG (DA) waves during sleep; cortical metabolic rate (CMR) measured with positron emission tomography; and synaptic density (SD) in frontal cortex. Each is at the adult level at birth, increases to about twice this level by 3 years of age, and then gradually falls back to the adult level over the next two decades. Statistical analyses revealed that individual gamma distribution models fit each data set as well as did the best ad hoc polynomial. A test of whether a single gamma distribution model could describe all three data sets gave good results for DA and CMR but the fit was unsatisfactory for SD. However, because so few data were available for SD, this test was not conclusive. We proposed the following model to account for these changes. First, cortical neurons are stimulated by birth to enter a proliferative state (PS) that creates many connections. Next, as a result of interactions in the PS, neurons are triggered into a transient organizational state (OS) in which they make enduring connections. The OS has a finite duration (minutes to years), and is characterized by high rates of information-processing and metabolism. Levels of CMR, SD and DA, therefore, are proportional to the number of neurons in the OS at any time. Thus, the cortex after birth duplicates, over a vastly greater time scale, the overproduction and regression of neural elements that occurs repeatedly in embryonic development. Finally, we discussed the implications of post-natal brain changes for normal and abnormal brain function. Mental disorders that have their onset after puberty (notably schizophrenia and manic-depressive psychoses) might be caused by errors in these late maturational processes. In addition to age of onset, this neurodevelopmental hypothesis might explain several other puzzling features of these subtle disorders.

  19. Bringing metabolic networks to life: convenience rate law and thermodynamic constraints

    Directory of Open Access Journals (Sweden)

    Klipp Edda

    2006-12-01

    Full Text Available Abstract Background Translating a known metabolic network into a dynamic model requires rate laws for all chemical reactions. The mathematical expressions depend on the underlying enzymatic mechanism; they can become quite involved and may contain a large number of parameters. Rate laws and enzyme parameters are still unknown for most enzymes. Results We introduce a simple and general rate law called "convenience kinetics". It can be derived from a simple random-order enzyme mechanism. Thermodynamic laws can impose dependencies on the kinetic parameters. Hence, to facilitate model fitting and parameter optimisation for large networks, we introduce thermodynamically independent system parameters: their values can be varied independently, without violating thermodynamical constraints. We achieve this by expressing the equilibrium constants either by Gibbs free energies of formation or by a set of independent equilibrium constants. The remaining system parameters are mean turnover rates, generalised Michaelis-Menten constants, and constants for inhibition and activation. All parameters correspond to molecular energies, for instance, binding energies between reactants and enzyme. Conclusion Convenience kinetics can be used to translate a biochemical network – manually or automatically - into a dynamical model with plausible biological properties. It implements enzyme saturation and regulation by activators and inhibitors, covers all possible reaction stoichiometries, and can be specified by a small number of parameters. Its mathematical form makes it especially suitable for parameter estimation and optimisation. Parameter estimates can be easily computed from a least-squares fit to Michaelis-Menten values, turnover rates, equilibrium constants, and other quantities that are routinely measured in enzyme assays and stored in kinetic databases.

  20. Metabolism

    Science.gov (United States)

    ... a particular food provides to the body. A chocolate bar has more calories than an apple, so ... acid phenylalanine, needed for normal growth and protein production). Inborn errors of metabolism can sometimes lead to ...

  1. How to determine control of growth rate in a chemostat. Using metabolic control analysis to resolve the paradox

    DEFF Research Database (Denmark)

    Snoep, Jacky L.; Jensen, Peter Ruhdal; Groeneveld, Philip

    1994-01-01

    how, paradoxically, one can determine control of growth rate, of growth yield and of other fluxes in a chemostat. We develop metabolic control analysis for the chemostat. this analysis does not depend on the particular way in which specific growth rate varies with the concentration of the growth...

  2. Variation in energy expenditure among black-legged kittiwakes : Effects of activity-specific metabolic rates and activity budgets

    NARCIS (Netherlands)

    Jodice, PGR; Roby, DD; Suryan, RM; Irons, DB; Kaufman, AM; Turco, KR; Visser, GH

    2003-01-01

    We sought to determine the effect of variation in time-activity budgets (TABs) and foraging behavior on energy expenditure rates of parent black-legged kittiwakes (Rissa tridactyla). We quantified TABs using direct observations of radio-tagged adults and simultaneously measured field metabolic rates

  3. Pulse pressure and heart rate in patients with metabolic syndrome across Europe: insights from the GOOD survey.

    Science.gov (United States)

    Perlini, S; Naditch-Brule, L; Farsang, C; Zidek, W; Kjeldsen, S E

    2013-07-01

    The Global Cardiometabolic Risk Profile in Patients with hypertension disease (GOOD) survey investigated the global cardiometabolic risk profile in 3464 adult outpatients with hypertension across 289 sites in 12 European countries. The pulse pressure and heart rate profile of the survey population was evaluated according to the presence or absence of metabolic syndrome and/or type 2 diabetes mellitus. History and treatment of hypertension were not counted as criteria for metabolic syndrome as they applied to all patients. Out of the 3370 recruited patients, 1033 had metabolic syndrome and 1177 had neither metabolic syndrome nor diabetes. When compared with patients with no metabolic syndrome or diabetes, patients with metabolic syndrome had higher pulse pressure (59±14 vs. 55±14 mm Hg) and heart rate (75.2±11.0 vs. 72.5±10.0 beats per min) (Ppulse pressure, which may at least in part reflect increased arterial stiffness and increased sympathetic tone. This may contribute, to some extent, to explaining the increased cardiovascular risk attributed to the presence of metabolic syndrome.

  4. Effect of nanoparticles of silver and gold on metabolic rate and development of broiler and layer embryos

    DEFF Research Database (Denmark)

    Pineda, L; Sawosz, E; Hotowy, A

    2012-01-01

    , their BW and muscle weights at hatching were similar to those of the control group, which suggests that the concentration of AgNano used was adequate for increasing the metabolic rate but not enough to affect growth and development. The results show that AgNano could be a potential metabolic modifier...... for layer embryos; however, the exact mechanism of action should be elucidated in future research....

  5. Scaling of resting and maximum hopping metabolic rate throughout the life cycle of the locust Locusta migratoria.

    Science.gov (United States)

    Snelling, Edward P; Seymour, Roger S; Matthews, Philip G D; Runciman, Sue; White, Craig R

    2011-10-01

    The hemimetabolous migratory locust Locusta migratoria progresses through five instars to the adult, increasing in size from 0.02 to 0.95 g, a 45-fold change. Hopping locomotion occurs at all life stages and is supported by aerobic metabolism and provision of oxygen through the tracheal system. This allometric study investigates the effect of body mass (Mb) on oxygen consumption rate (MO2, μmol h(-1)) to establish resting metabolic rate (MRO2), maximum metabolic rate during hopping (MMO2) and maximum metabolic rate of the hopping muscles (MMO2,hop) in first instar, third instar, fifth instar and adult locusts. Oxygen consumption rates increased throughout development according to the allometric equations MRO2=30.1Mb(0.83±0.02), MMO2=155Mb(1.01±0.02), MMO2,hop=120Mb(1.07±0.02) and, if adults are excluded, MMO2,juv=136Mb(0.97±0.02) and MMO2,juv,hop=103Mb(1.02±0.02). Increasing body mass by 20-45% with attached weights did not increase mass-specific MMO2 significantly at any life stage, although mean mass-specific hopping MO2 was slightly higher (ca. 8%) when juvenile data were pooled. The allometric exponents for all measures of metabolic rate are much greater than 0.75, and therefore do not support West, Brown and Enquist’s optimised fractal network model, which predicts that metabolism scales with a 3⁄4-power exponent owing to limitations in the rate at which resources can be transported within the body.

  6. Co-variation of metabolic rates and cell-size in coccolithophores

    Directory of Open Access Journals (Sweden)

    G. Aloisi

    2015-04-01

    Full Text Available Coccolithophores are sensitive recorders of environmental change. The size of their coccosphere varies in the ocean along gradients of environmental conditions and provides a key for understanding the fate of this important phytoplankton group in the future ocean. But interpreting field changes in coccosphere size in terms of laboratory observations is hard, mainly because the marine signal reflects the response of multiple morphotypes to changes in a combination of environmental variables. In this paper I examine the large corpus of published laboratory experiments with coccolithophores looking for relations between environmental conditions, metabolic rates and cell size (a proxy for coccosphere size. I show that growth, photosynthesis, and to a lesser extent calcification, co-vary with cell size when pCO2, irradiance, temperature, nitrate, phosphate and iron conditions change. With the exception of phosphate and temperature, a change from limiting to non-limiting conditions always results in an increase in cell size. An increase in phosphate or temperature produces the opposite effect. The magnitude of the coccosphere size changes observed in the laboratory is comparable to that observed in the ocean. If the biological reasons behind the environment-metabolism-size link are understood, it will be possible to use coccosphere size changes in the modern ocean and in marine sediments to investigate the fate of coccolithophores in the future ocean. This reasoning can be extended to the size of coccoliths if, as recent experiments are starting to show, coccolith size reacts to environmental change proportionally to coccosphere size. I introduce a simple model that simulates the growth rate and the size of cells forced by nitrate and phosphate concentrations. By considering a simple rule that allocates the energy flow from nutrient acquisition to cell structure (biomass and cell maturity (biological complexity, eventually leading to cell division

  7. Dietary supplement increases plasma norepinephrine, lipolysis, and metabolic rate in resistance trained men

    Directory of Open Access Journals (Sweden)

    Schilling Brian K

    2009-01-01

    Full Text Available Abstract Background Dietary supplements targeting fat loss and increased thermogenesis are prevalent within the sport nutrition/weight loss market. While some isolated ingredients have been reported to be efficacious when used at high dosages, in particular in animal models and/or via intravenous delivery, little objective evidence is available pertaining to the efficacy of a finished product taken by human subjects in oral form. Moreover, many ingredients function as stimulants, leading to increased hemodynamic responses. The purpose of this investigation was to determine the effects of a finished dietary supplement on plasma catecholamine concentration, markers of lipolysis, metabolic rate, and hemodynamics. Methods Ten resistance trained men (age = 27 ± 4 yrs; BMI = 25 ± 3 kg· m-2; body fat = 9 ± 3%; mean ± SD ingested a dietary supplement (Meltdown®, Vital Pharmaceuticals or a placebo, in a random order, double blind cross-over design, with one week separating conditions. Fasting blood samples were collected before, and at 30, 60, and 90 minutes post ingestion and were assayed for epinephrine (EPI, norepinephrine (NE, glycerol, and free fatty acids (FFA. Area under the curve (AUC was calculated for all variables. Gas samples were collected from 30–60 minutes post ingestion for measurement of metabolic rate. Heart rate and blood pressure were recorded at all blood collection times. Results AUC was greater for the dietary supplement compared to the placebo for NE (1332 ± 128 pg·mL-1·90 min-1 vs. 1003 ± 133 pg·mL-1·90 min-1; p = 0.03, glycerol (44 ± 3 μg·mL-1·90 min-1 vs. 26 ± 2 μg·mL-1·90 min-1; p -1·90 min-1 vs. 0.88 ± 0.12 mmol·L-1·90 min-1; p = 0.0003. No difference between conditions was noted for EPI AUC (p > 0.05. For all variables, values were highest at 90 minutes post ingestion. Total kilocalorie expenditure during the 30 minute collection period was 29.6% greater (p = 0.02 for the dietary supplement (35 ± 3

  8. Metabolic rate limits the effect of sperm competition on mammalian spermatogenesis.

    Science.gov (United States)

    delBarco-Trillo, Javier; Tourmente, Maximiliano; Roldan, Eduardo R S

    2013-01-01

    Sperm competition leads to increased sperm production in many taxa. This response may result from increases in testes size, changes in testicular architecture or changes in the kinetics of spermatogenesis, but the impact of each one of these processes on sperm production has not been studied in an integrated manner. Furthermore, such response may be limited in species with low mass-specific metabolic rate (MSMR), i.e., large-bodied species, because they cannot process energy and resources efficiently enough both at the organismic and cellular levels. Here we compare 99 mammalian species and show that higher levels of sperm competition correlated with a) higher proportions of seminiferous tubules, b) shorter seminiferous epithelium cycle lengths (SECL) which reduce the time required to produce sperm, and c) higher efficiencies of Sertoli cells (involved in sperm maturation). These responses to sperm competition, in turn, result in higher daily sperm production, more sperm stored in the epididymides, and more sperm in the ejaculate. However, the two processes that require processing resources at faster rates (SECL and efficiency of Sertoli cells) only respond to sperm competition in species with high MSMR. Thus, increases in sperm production with intense sperm competition occur via a complex network of mechanisms, but some are constrained by MSMR.

  9. Scaling up the curvature of mammalian metabolism

    Directory of Open Access Journals (Sweden)

    Juan eBueno

    2014-10-01

    Full Text Available A curvilinear relationship between mammalian metabolic rate and body size on a log-log scale has been adopted in lieu of thelongstanding concept of a 3/4 allometric relationship (Kolokotrones et al. 2010. The central tenet of Metabolic Ecology (ME states that metabolism at the individual level scales-up to drive the ecology of populations, communities and ecosystems. If this tenet is correct, the curvature of metabolism should be perceived in other ecological traits. By analyzing the size scaling allometry of eight different mammalian traits including basal and field metabolic rate, offspring biomass production, ingestion rate, costs of locomotion, life span, population growth rate and population density we show that the curvature affects most ecological rates and

  10. Novel approach for evaluation of air change rate in naturally ventilated occupied spaces based on metabolic CO2 time variation

    DEFF Research Database (Denmark)

    Melikov, Arsen Krikor; Markov, Detelin G.

    2014-01-01

    , air-tight space, constant indoor pressure and temperature. The proposed approach for ACR evaluation can be applied to time intervals with any length, even with varying parameters of both indoor and outdoor air, in which metabolic CO2 generation rate is known and constant. This approach makes possible......IAQ in many residential buildings relies on non-organized natural ventilation. Accurate evaluation of air change rate (ACR) in this situation is difficult due to the nature of the phenomenon - intermittent infiltration-exfiltration periods of mass exchange between the room air and the outdoor air...... at low rate. This paper describes a new approach for ACR evaluation in naturally ventilated occupied spaces. Actual metabolic CO2 time variation record in an interval of time is compared with the computed variation of metabolic CO2 for the same time interval under reference conditions: sleeping occupants...

  11. Effectiveness of eugenol sedation to reduce the metabolic rates of cool and warm water fish at high loading densities

    Science.gov (United States)

    Cupp, Aaron R.; Hartleb, Christopher F.; Fredricks, Kim T.; Gaikowski, Mark P.

    2016-01-01

    Effects of eugenol (AQUI-S®20E, 10% active eugenol) sedation on cool water, yellow perch Perca flavescens (Mitchill), and warm water, Nile tilapia Oreochromis niloticus L. fish metabolic rates were assessed. Both species were exposed to 0, 10, 20 and 30 mg L−1 eugenol using static respirometry. In 17°C water and loading densities of 60, 120 and 240 g L−1, yellow perch controls (0 mg L−1 eugenol) had metabolic rates of 329.6–400.0 mg O2 kg−1 h−1, while yellow perch exposed to 20 and 30 mg L−1 eugenol had significantly reduced metabolic rates of 258.4–325.6 and 189.1–271.0 mg O2 kg−1 h−1 respectively. Nile tilapia exposed to 30 mg L−1 eugenol had a significantly reduced metabolic rate (424.5 ± 42.3 mg O2 kg−1 h−1) relative to the 0 mg L−1 eugenol control (546.6 ± 53.5 mg O2 kg−1 h−1) at a loading density of 120 g L−1 in 22°C water. No significant differences in metabolic rates for Nile tilapia were found at 240 or 360 g L−1 loading densities when exposed to eugenol. Results suggest that eugenol sedation may benefit yellow perch welfare at high densities (e.g. live transport) due to a reduction in metabolic rates, while further research is needed to assess the benefits of eugenol sedation on Nile tilapia at high loading densities.

  12. Bile acid sequestration reduces plasma glucose levels in db/db mice by increasing its metabolic clearance rate.

    Directory of Open Access Journals (Sweden)

    Maxi Meissner

    Full Text Available AIMS/HYPOTHESIS: Bile acid sequestrants (BAS reduce plasma glucose levels in type II diabetics and in murine models of diabetes but the mechanism herein is unknown. We hypothesized that sequestrant-induced changes in hepatic glucose metabolism would underlie reduced plasma glucose levels. Therefore, in vivo glucose metabolism was assessed in db/db mice on and off BAS using tracer methodology. METHODS: Lean and diabetic db/db mice were treated with 2% (wt/wt in diet Colesevelam HCl (BAS for 2 weeks. Parameters of in vivo glucose metabolism were assessed by infusing [U-(13C]-glucose, [2-(13C]-glycerol, [1-(2H]-galactose and paracetamol for 6 hours, followed by mass isotopologue distribution analysis, and related to metabolic parameters as well as gene expression patterns. RESULTS: Compared to lean mice, db/db mice displayed an almost 3-fold lower metabolic clearance rate of glucose (p = 0.0001, a ∼300% increased glucokinase flux (p = 0.001 and a ∼200% increased total hepatic glucose production rate (p = 0.0002. BAS treatment increased glucose metabolic clearance rate by ∼37% but had no effects on glucokinase flux nor total hepatic or endogenous glucose production. Strikingly, BAS-treated db/db mice displayed reduced long-chain acylcarnitine content in skeletal muscle (p = 0.0317 but not in liver (p = 0.189. Unexpectedly, BAS treatment increased hepatic FGF21 mRNA expression 2-fold in lean mice (p = 0.030 and 3-fold in db/db mice (p = 0.002. CONCLUSIONS/INTERPRETATION: BAS induced plasma glucose lowering in db/db mice by increasing metabolic clearance rate of glucose in peripheral tissues, which coincided with decreased skeletal muscle long-chain acylcarnitine content.

  13. METABOLISM

    Institute of Scientific and Technical Information of China (English)

    1999-01-01

    Objective: To determine the allele frequencies of genetic variants 373 Ala→Pro and 451 Arg→Gln of cholesteryl ester transfer protein (CETP) and to explore their potential impacts on serum lipid metabolism. Methods: The genotypes in CETP codon 373 and 451 in 91 German healthy students and 409 an-

  14. Interspecific Differences in Metabolic Rate and Metabolic Temperature Sensitivity Create Distinct Thermal Ecological Niches in Lizards (Plestiodon)

    Science.gov (United States)

    Watson, Charles M.; Burggren, Warren W.

    2016-01-01

    Three congeneric lizards from the southeastern United States (Plestiodon fasciatus, P. inexpectatus, and P. laticeps) exhibit a unique nested distribution. All three skink species inhabit the US Southeast, but two extend northward to central Ohio (P. fasciatus and P. laticeps) and P. fasciatus extends well into Canada. Distinct interspecific differences in microhabitat selection and behavior are associated with the cooler temperatures of the more Northern ranges. We hypothesized that interspecific differences in metabolic temperature sensitivity locally segregates them across their total range. Resting oxygen consumption was measured at 20°, 25° and 30°C. Plestiodon fasciatus, from the coolest habitats, exhibited greatly elevated oxygen consumption compared to the other species at high ecologically-relevant temperatures (0.10, 0.17 and 0.83 ml O2. g-1. h-1 at 20°, 25° and 30°C, respectively). Yet, P. inexpectatus, from the warmest habitats, exhibited sharply decreased oxygen consumption compared to the other species at lower ecologically-relevant temperatures (0.09, 0.27 and 0.42 ml O2. g-1. h-1 at 20°, 25° and 30°C, respectively). Plestiodon laticeps, from both open and closed microhabitats and intermediate latitudinal range, exhibited oxygen consumptions significantly lower than the other two species (0.057, 0.104 and 0.172 ml O2. g-1. h-1 at 20°, 25° and 30°C, respectively). Overall, Plestiodon showed metabolic temperature sensitivities (Q10s) in the range of 2–3 over the middle of each species’ normal temperature range. However, especially P. fasciatus and P. inexpectatus showed highly elevated Q10s (9 to 25) at the extreme ends of their temperature range. While morphologically similar, these skinks are metabolically distinct across the genus’ habitat, likely having contributed to their current distribution. PMID:27760215

  15. Increasing ankle push-off work with a powered prosthesis does not necessarily reduce metabolic rate for transtibial amputees.

    Science.gov (United States)

    Quesada, Roberto E; Caputo, Joshua M; Collins, Steven H

    2016-10-03

    Amputees using passive ankle-foot prostheses tend to expend more metabolic energy during walking than non-amputees, and reducing this cost has been a central motivation for the development of active ankle-foot prostheses. Increased push-off work at the end of stance has been proposed as a way to reduce metabolic energy use, but the effects of push-off work have not been tested in isolation. In this experiment, participants with unilateral transtibial amputation (N=6) walked on a treadmill at a constant speed while wearing a powered prosthesis emulator. The prosthesis delivered different levels of ankle push-off work across conditions, ranging from the value for passive prostheses to double the value for non-amputee walking, while all other prosthesis mechanics were held constant. Participants completed six acclimation sessions prior to a data collection in which metabolic rate, kinematics, kinetics, muscle activity and user satisfaction were recorded. Metabolic rate was not affected by net prosthesis work rate (p=0.5; R(2)=0.007). Metabolic rate, gait mechanics and muscle activity varied widely across participants, but no participant had lower metabolic rate with higher levels of push-off work. User satisfaction was affected by push-off work (p=0.002), with participants preferring values of ankle push-off slightly higher than in non-amputee walking, possibly indicating other benefits. Restoring or augmenting ankle push-off work is not sufficient to improve energy economy for lower-limb amputees. Additional necessary conditions might include alternate timing or control, individualized tuning, or particular subject characteristics.

  16. Metabolic rate and membrane fatty acid composition in birds: a comparison between long-living parrots and short-living fowl.

    Science.gov (United States)

    Montgomery, Magdalene K; Hulbert, A J; Buttemer, William A

    2012-01-01

    Both basal metabolic rate (BMR) and maximum lifespan potential (MLSP) vary with body size in mammals and birds and it has been suggested that these are mediated through size-related variation in membrane fatty acid composition. Whereas the physical properties of membrane fatty acids affect the activity of membrane proteins and, indirectly, an animal's BMR, it is the susceptibility of those fatty acids to peroxidation which influence MLSP. Although there is a correlation between body size and MLSP, there is considerable MLSP variation independent of body size. For example, among bird families, Galliformes (fowl) are relatively short-living and Psittaciformes (parrots) are unusually long-living, with some parrot species reaching maximum lifespans of more than 100 years. We determined BMR and tissue phospholipid fatty acid composition in seven tissues from three species of parrots with an average MLSP of 27 years and from two species of quails with an average MLSP of 5.5 years. We also characterised mitochondrial phospholipids in two of these tissues. Neither BMR nor membrane susceptibility to peroxidation corresponded with differences in MLSP among the birds we measured. We did find that (1) all birds had lower n-3 polyunsaturated fatty acid content in mitochondrial membranes compared to those of the corresponding tissue, and that (2) irrespective of reliance on flight for locomotion, both pectoral and leg muscle had an almost identical membrane fatty acid composition in all birds.

  17. Growth against entropy in bacterial metabolism: the phenotypic trade-off behind empirical growth rate distributions in E. coli

    Science.gov (United States)

    De Martino, Daniele; Capuani, Fabrizio; De Martino, Andrea

    2016-06-01

    The solution space of genome-scale models of cellular metabolism provides a map between physically viable flux configurations and cellular metabolic phenotypes described, at the most basic level, by the corresponding growth rates. By sampling the solution space of E. coli's metabolic network, we show that empirical growth rate distributions recently obtained in experiments at single-cell resolution can be explained in terms of a trade-off between the higher fitness of fast-growing phenotypes and the higher entropy of slow-growing ones. Based on this, we propose a minimal model for the evolution of a large bacterial population that captures this trade-off. The scaling relationships observed in experiments encode, in such frameworks, for the same distance from the maximum achievable growth rate, the same degree of growth rate maximization, and/or the same rate of phenotypic change. Being grounded on genome-scale metabolic network reconstructions, these results allow for multiple implications and extensions in spite of the underlying conceptual simplicity.

  18. Does amifostine reduce metabolic rate? Effect of the drug on gas exchange and acute ventilatory hypoxic response in humans.

    Science.gov (United States)

    Pandit, Jaideep J; Allen, Caroline; Little, Evelyn; Formenti, Federico; Harris, Adrian L; Robbins, Peter A

    2015-04-16

    Amifostine is added to chemoradiation regimens in the treatment of many cancers on the basis that, by reducing the metabolic rate, it protects normal cells from toxic effects of therapy. We tested this hypothesis by measuring the metabolic rate (by gas exchange) over 255 min in 6 healthy subjects, at two doses (500 mg and 1000 mg) of amifostine infused over 15 min at the start of the protocol. We also assessed the ventilatory response to six 1 min exposures to isocapnic hypoxia mid-protocol. There was no change in metabolic rate with amifostine as measured by oxygen uptake (p = 0.113). However in carbon dioxide output and respiratory quotient, we detected a small decline over time in control and drug protocols, consistent with a gradual change from carbohydrate to fat metabolism over the course of the relatively long study protocol. A novel result was that amifostine (1000 mg) increased the mean ± SD acute hypoxic ventilatory response from 12.4 ± 5.1 L/min to 20.3 ± 11.9 L/min (p = 0.045). In conclusion, any cellular protective effects of amifostine are unlikely due to metabolic effects. The stimulatory effect on hypoxic ventilatory responses may be due to increased levels of hypoxia inducible factor, either peripherally in the carotid body, or centrally in the brain.

  19. Seasonal and inter-annual variations of community metabolism rates of a Posidonia oceanica seagrass meadow

    Science.gov (United States)

    Champenois, W.; Borges, A. V.

    2012-04-01

    We report gross primary production (GPP), community respiration (CR), and net community production (NCP) over Posidonia oceanica meadow at 10 m in Corsica (Bay of Revellata) based on the open water O2 mass balance from a data-set of hourly measurements with an array of three O2 optodes deployed from August 2006 to October 2009. The method was checked by comparison with discrete measurements of metabolic rates derived from benthic chamber incubations also based on the diel change of O2. This comparison was satisfactory and actually highlights the potential caveats of benthic incubation measurements related to O2 accumulation in small chambers leading to photorespiration, and an under-estimation of GPP. Our data confirmed previous P. oceanica meadows GPP and CR values, strong seasonal variations, and net autotrophy. High resolution data revealed strong inter-annual variability, with a decrease of GPP by 35% and NCP by 87% during 2006-2007 characterized by a mild and less stormy winter compared 2007-2008 and 2008-2009. P. oceanica meadows are then expected to decrease export of organic carbon to adjacent communities (decrease of NCP), since a decrease in frequency and intensity of marine storms is expected in future in the Mediterranean Sea, due to a northward shift of the Atlantic storm track.

  20. Metabolic energy correlates of heart rate variability spectral power associated with a 900-calorie challenge.

    Science.gov (United States)

    Millis, Richard M; Austin, Rachel E; Hatcher, Mark D; Bond, Vernon; Goring, Kim L

    2011-01-01

    We studied healthy males challenged with a 900 Cal test beverage and correlated EE with the raw (ms(2)) and normalized units (nu) of total power (TP), low frequency/high frequency (LF/HF) and VLF spectral power of heart rate variability (HRV). The correlations were evaluated during 20 min of normal breathing (NB, control) and 20 min of paced breathing (PB) at 12 breaths·min(-1) (0.2 Hz). EE was not significantly correlated with any of the HRV variables before the metabolic challenge. After the challenge, EE was positively correlated with LF/HF and with VLF; VLF was also positively correlated with LF/HF during both NB and PB. These findings suggest that EE may be a correlate of LF/HF and of VLF spectral power of HRV in healthy adolescent/young adult males. The association of lower resting energy expenditure with lower amounts of VLF spectral power may occur in individuals with predilections for obese phenotypes.

  1. Metabolic Energy Correlates of Heart Rate Variability Spectral Power Associated with a 900-Calorie Challenge

    Directory of Open Access Journals (Sweden)

    Richard M. Millis

    2011-01-01

    Full Text Available We studied healthy males challenged with a 900 Cal test beverage and correlated EE with the raw (ms2 and normalized units (nu of total power (TP, low frequency/high frequency (LF/HF and VLF spectral power of heart rate variability (HRV. The correlations were evaluated during 20 min of normal breathing (NB, control and 20 min of paced breathing (PB at 12 breaths⋅min−1 (0.2 Hz. EE was not significantly correlated with any of the HRV variables before the metabolic challenge. After the challenge, EE was positively correlated with LF/HF and with VLF; VLF was also positively correlated with LF/HF during both NB and PB. These findings suggest that EE may be a correlate of LF/HF and of VLF spectral power of HRV in healthy adolescent/young adult males. The association of lower resting energy expenditure with lower amounts of VLF spectral power may occur in individuals with predilections for obese phenotypes.

  2. Temperature dependences of growth rates and carrying capacities of marine bacteria depart from metabolic theoretical predictions

    KAUST Repository

    Huete-Stauffer, Tamara Megan

    2015-09-11

    Using the metabolic theory of ecology (MTE) framework, we evaluated over a whole annual cycle the monthly responses to temperature of the growth rates (μ) and carrying capacities (K) of heterotrophic bacterioplankton at a temperate coastal site. We used experimental incubations spanning 6oC with bacterial physiological groups identified by flow cytometry according to membrane integrity (live), nucleic acid content (HNA and LNA) and respiratory activity (CTC+). The temperature dependence of μat the exponential phase of growth was summarized by the activation energy (E), which was variable (-0.52 to 0.72 eV) but followed a seasonal pattern, only reaching the hypothesized value for aerobic heterotrophs of 0.65 eV during the spring bloom for the most active bacterial groups (live, HNA, CTC+). K (i.e. maximum experimental abundance) peaked at 4 × 106 cells mL-1 and generally covaried with μbut, contrary to MTE predictions, it did not decrease consistently with temperature. In the case of live cells, the responses of μand K to temperature were positively correlated and related to seasonal changes in substrate availability, indicating that the responses of bacteria to warming are far from homogeneous and poorly explained by MTE at our site. © FEMS 2015.

  3. Specific heat flow rate: an on-line monitor and potential control variable of specific metabolic rate in animal cell culture that combines microcalorimetry with dielectric spectroscopy.

    Science.gov (United States)

    Guan, Y; Evans, P M; Kemp, R B

    1998-06-05

    One of the requirements for enhanced productivity by the animal culture systems used in biotechnology is the direct assessment of the metabolic rate by on-line biosensors. Based on the fact that cell growth is associated with an enthalpy change, it is shown that the specific heat flow rate is stoichiometrically related to the net specific rates of substrates, products, and indeed to specific growth rate, and therefore a direct reflection of metabolic rate. Heat flow rate measured by conduction calorimetry has a technical advantage over estimates for many material flows which require assays at a minimum of two discrete times to give the rate. In order to make heat flow rate specific to the amount of the living cellular system, it would be advantageous to divide it by viable biomass. This requirement has been fulfilled by combining a continuous flow microcalorimeter ex situ with a dielectric spectroscope in situ, the latter measuring the viable cell mass volume fraction. The quality of the resulting biosensor for specific heat flow rate was illustrated using batch cultures of Chinese hamster ovary cells (CHO 320) producing recombinant human interferon-gamma (IFN-gamma) during growth in a stirred tank bioreactor under fully aerobic conditions. The measuring scatter of the probe was decreased significantly by applying the moving average technique to the two participant signals. It was demonstrated that the total metabolic rate of the cells, as indicated by the specific heat flow rate sensor, decreased with increasing time in batch culture, coincident with the decline in the two major substrates, glucose and glutamine, and the accumulation of the by-products, ammonia and lactate. Furthermore, the specific heat flow rate was an earlier indicator of substrate depletion than the flow rate alone. The calorimetric-respirometric ratio showed the intensive participation of anaerobic processes during growth and the related IFN-gamma production. Specific heat flow rate was

  4. Comparison of Indirect Calorimetry and Predictive Equations in Estimating Resting Metabolic Rate in Underweight Females

    Directory of Open Access Journals (Sweden)

    Soghra ALIASGHARZADEH

    2015-10-01

    Full Text Available Background: Underweight as a public health problem in young women is associated with nutritional deficiencies, menstrual irregularity, eating disorders, reduced fertility, etc. Since resting metabolic rate (RMR is a necessary compo-nent in the development of nutrition support therapy, therefore we determined the accuracy of commonly used pre-dictive equations against RMR measured by indirect calorimetry among healthy young underweight females.Methods: This cross-sectional study was conducted on 104 underweight females aged 18-30 years old with body mass index (BMI <18.5 kg/m2 in 2013 . After collecting anthropometric data, body composition was measured by bioelec-tric impedance analysis (BIA. RMR was measured by using indirect calorimetry (FitMate™ and was estimated by 10 commonly used predictive equations. Comparisons were conducted using paired t-test. The accuracy of the RMR equations was evaluated on the basis of the percentage of subjects’ predicted RMR within 10% of measured RMR.Results: The mean BMI of subjects was 17.3±1.3 kg/m2. The measured RMR ranged 736-1490 kcal/day (mean 1084.7±175 kcal/day. Findings indicated that except Muller and Abbreviation, other equations significantly over es-timated RMR, compared to measured value (P<0.05. As an individual prediction accuracy, these predictive equations showed poor performance with the highest accuracy rate of 54.8% for Muller equation (22.1% under and 23.1% over-prediction and 43.3% for Abbreviation equation (31.7% under and 25% over-prediction, the percentage bias was 1.8% and 0.63% and RMSE was 162 and 173 kcal/d, respectively.Conclusion: Although Muller equation gave fairly acceptable prediction, more suitable new equations are needed to be developed to help better management of nutritional plans in young underweight people.

  5. ASSOCIATION BETWEEN HEART RATE VARIABILITY AND COMPONENTS OF THE METABOLIC SYNDROME IN WOMEN WITH RHEUMATOID ARTHRITIS

    Directory of Open Access Journals (Sweden)

    D. S. Novikova

    2014-01-01

    Full Text Available Aim. To study the relationship between heart rate variability (HRV and components of the metabolic syndrome (MS in women with rheumatoid arthritis (RA.Material and methods. Female patients (n=291 with a firm RA diagnosis under 60 years of age were examined. Evaluation of traditional cardiovascular risk factors, MS components (International Diabetes Federation criteria, 24-hour ECG monitoring were performed along with the assessment of clinical symptoms, the degree of activity and severity of RA.Results. Weak associations of HRV with waist circumference, blood pressure level, hypertriglyceridemia, hypoalphalipoproteinemia and smoking were found in the correlation analysis. Patients with RA were divided into three groups depending on the number of existing MS components. Group 1 (0-1 component included 113 women (39%, group 2 (2-3 components – 109 women (37% and group 3 (4-5 components – included 69 women with RA (24%. Progressive decrease in the absolute values and the increase in the percentage of the low values of all the studied time and frequency HRV indices, adjusted by age and heart rate, from the 1st to the 3rd group of women with RA were determined. Significant increase in sympathovagal index from the 1st to the 3rd group was also shown.Conclusion. A combination of several components of the MS in RA plays a greater role in the development of disorders of neurovegetative autonomic control of heart activity (increased influence of the sympathetic and/or reduced influence of the parasympathetic nervous system on cardiac function than each traditional cardiovascular risk factor taken separately. Abnormality in autonomic regulation of cardiac activity may be an important link in the pathogenesis of cardiac arrhythmias, sudden cardiac death and overall cardiovascular mortality in women with RA.

  6. Maximal sum of metabolic exchange fluxes outperforms biomass yield as a predictor of growth rate of microorganisms.

    Science.gov (United States)

    Zarecki, Raphy; Oberhardt, Matthew A; Yizhak, Keren; Wagner, Allon; Shtifman Segal, Ella; Freilich, Shiri; Henry, Christopher S; Gophna, Uri; Ruppin, Eytan

    2014-01-01

    Growth rate has long been considered one of the most valuable phenotypes that can be measured in cells. Aside from being highly accessible and informative in laboratory cultures, maximal growth rate is often a prime determinant of cellular fitness, and predicting phenotypes that underlie fitness is key to both understanding and manipulating life. Despite this, current methods for predicting microbial fitness typically focus on yields [e.g., predictions of biomass yield using GEnome-scale metabolic Models (GEMs)] or notably require many empirical kinetic constants or substrate uptake rates, which render these methods ineffective in cases where fitness derives most directly from growth rate. Here we present a new method for predicting cellular growth rate, termed SUMEX, which does not require any empirical variables apart from a metabolic network (i.e., a GEM) and the growth medium. SUMEX is calculated by maximizing the SUM of molar EXchange fluxes (hence SUMEX) in a genome-scale metabolic model. SUMEX successfully predicts relative microbial growth rates across species, environments, and genetic conditions, outperforming traditional cellular objectives (most notably, the convention assuming biomass maximization). The success of SUMEX suggests that the ability of a cell to catabolize substrates and produce a strong proton gradient enables fast cell growth. Easily applicable heuristics for predicting growth rate, such as what we demonstrate with SUMEX, may contribute to numerous medical and biotechnological goals, ranging from the engineering of faster-growing industrial strains, modeling of mixed ecological communities, and the inhibition of cancer growth.

  7. Maximal sum of metabolic exchange fluxes outperforms biomass yield as a predictor of growth rate of microorganisms.

    Directory of Open Access Journals (Sweden)

    Raphy Zarecki

    Full Text Available Growth rate has long been considered one of the most valuable phenotypes that can be measured in cells. Aside from being highly accessible and informative in laboratory cultures, maximal growth rate is often a prime determinant of cellular fitness, and predicting phenotypes that underlie fitness is key to both understanding and manipulating life. Despite this, current methods for predicting microbial fitness typically focus on yields [e.g., predictions of biomass yield using GEnome-scale metabolic Models (GEMs] or notably require many empirical kinetic constants or substrate uptake rates, which render these methods ineffective in cases where fitness derives most directly from growth rate. Here we present a new method for predicting cellular growth rate, termed SUMEX, which does not require any empirical variables apart from a metabolic network (i.e., a GEM and the growth medium. SUMEX is calculated by maximizing the SUM of molar EXchange fluxes (hence SUMEX in a genome-scale metabolic model. SUMEX successfully predicts relative microbial growth rates across species, environments, and genetic conditions, outperforming traditional cellular objectives (most notably, the convention assuming biomass maximization. The success of SUMEX suggests that the ability of a cell to catabolize substrates and produce a strong proton gradient enables fast cell growth. Easily applicable heuristics for predicting growth rate, such as what we demonstrate with SUMEX, may contribute to numerous medical and biotechnological goals, ranging from the engineering of faster-growing industrial strains, modeling of mixed ecological communities, and the inhibition of cancer growth.

  8. Differences in resting metabolic rate and physical activity patterns in lean and overweight/obese pregnant women

    Science.gov (United States)

    Energy requirements vary during pregnancy due to changes in physical activity (PA) and maternal fat stores. This study measured resting metabolic rate (RMR) and PA patterns in healthy lean and overweight/obese (OW) pregnant women. RMR was measured using indirect calorimetry (MOXUS), activity pattern...

  9. Metabolic rate of spiders (Pardosa prativage) feed on prey species of different diet quality measured by colorimetry

    DEFF Research Database (Denmark)

    Nielsen, Søren Achim; Kynde, Bjarke; Westh, Peter

    The metabolic rate was measured in the wolf spider Pardosa prativaga after preying different species of aphids, collembolans and fruit flies raised on common commercial medium. The activity of detoxification enzyme systems Glutathione S-Transferase (GST), Glutathione Peroxidase (GSTpx) was invest...

  10. Monitoring and prevalence rates of metabolic syndrome in military veterans with serious mental illness.

    Directory of Open Access Journals (Sweden)

    Sameed Ahmed M Khatana

    Full Text Available BACKGROUND: Cardiovascular disease is the leading cause of mortality among patients with serious mental illness (SMI and the prevalence of metabolic syndrome--a constellation of cardiovascular risk factors--is significantly higher in these patients than in the general population. Metabolic monitoring among patients using second generation antipsychotics (SGAs--a risk factor for metabolic syndrome--has been shown to be inadequate despite the release of several guidelines. However, patients with SMI have several factors independent of medication use that predispose them to a higher prevalence of metabolic syndrome. Our study therefore examines monitoring and prevalence of metabolic syndrome in patients with SMI, including those not using SGAs. METHODS AND FINDINGS: We retrospectively identified all patients treated at a Veterans Affairs Medical Center with diagnoses of schizophrenia, schizoaffective disorder or bipolar disorder during 2005-2006 and obtained demographic and clinical data. Incomplete monitoring of metabolic syndrome was defined as being unable to determine the status of at least one of the syndrome components. Of the 1,401 patients included (bipolar disorder: 822; schizophrenia: 222; and schizoaffective disorder: 357, 21.4% were incompletely monitored. Only 54.8% of patients who were not prescribed SGAs and did not have previous diagnoses of hypertension or hypercholesterolemia were monitored for all metabolic syndrome components compared to 92.4% of patients who had all three of these characteristics. Among patients monitored for metabolic syndrome completely, age-adjusted prevalence of the syndrome was 48.4%, with no significant difference between the three psychiatric groups. CONCLUSIONS: Only one half of patients with SMI not using SGAs or previously diagnosed with hypertension and hypercholesterolemia were completely monitored for metabolic syndrome components compared to greater than 90% of those with these characteristics

  11. The effect of microbial glucose metabolism on bytownite feldspar dissolution rates between 5° and 35°C

    Science.gov (United States)

    Welch, S. A.; Ullman, W. J.

    1999-10-01

    The rate of Si release from dissolving bytownite feldspar in abiotic batch reactors increased as temperatures increased from 5° to 35°C. Metabolically inert subsurface bacteria (bacteria in solution with no organic substrate) had no apparent effect on dissolution rates over this temperature range. When glucose was added to the microbial cultures, the bacteria responded by producing gluconic acid, which catalyzed the dissolution reaction by both proton- and ligand-promoted mechanisms. The metabolic production, excretion, and consumption of gluconic acid in the course of glucose oxidation, and therefore, the degree of microbial enhancement of mineral dissolution, depend on temperature. There was little accumulation of gluconic acid and therefore, no significant enhancement of mineral dissolution rates at 35°C compared to the abiotic controls. At 20°C, gluconate accumulated in the experimental solutions only at the beginning of the experiment and led to a twofold increase in dissolved Si release compared to the controls, primarily by the ligand-promoted dissolution mechanism. There was significant accumulation of gluconic acid in the 5°C experiment, which is reflected in a significant reduction in pH, leading to 20-fold increase in Si release, primarily attributable to the proton-promoted dissolution mechanism. These results indicate that bacteria and microbial metabolism can affect mineral dissolution rates in organic-rich, nutrient-poor environments; the impact of microbial metabolism on aluminum silicate dissolution rates may be greater at lower rather than at higher temperatures due to the metabolic accumulation of dissolution-enhancing protons and ligands in solution.

  12. The Coupling of Cerebral Metabolic Rate of Glucose and Cerebral Blood Flow In Vivo

    DEFF Research Database (Denmark)

    Hasselbalch, Steen; Paulson, Olaf Bjarne

    2012-01-01

    The energy supplied to the brain by metabolic substrate is largely utilized for maintaining synaptic transmission. In this regulation cerebral blood flow and glucose consumption is tightly coupled as well in the resting condition as during activation. Quantification of cerebral blood flow...... not used for aerobic metabolism. Although some of the excess glucose uptake can be explained by lactate production, this phenomenon can still not account for the excess glucose uptake. Thus, more complex metabolic patterns in the brain might be reflected in the excess glucose uptake during activation...

  13. Seasonally constant field metabolic rates in free-ranging sugar gliders (Petaurus breviceps).

    Science.gov (United States)

    Quin, Darren G; Riek, Alexander; Green, Stuart; Smith, Andrew P; Geiser, Fritz

    2010-03-01

    Sugar gliders, Petaurus breviceps (average body mass: 120 g) like other small wild mammals must cope with seasonal changes in food availability and weather and therefore thermoregulatory and energetic challenges. To determine whether free-ranging sugar gliders, an arboreal marsupial, seasonally adjust their energy expenditure and water use, we quantified field metabolic rates (FMR) and water flux at a seasonal cool-temperate site in eastern Australia. Thirty six male and female sugar gliders were labelled with doubly labelled water for this purpose in spring, summer and autumn. The mean FMR was 159+/-6 kJ d(-1) (spring), 155+/-8 kJ d(-1) (summer), and 152+/-20 kJ d(-1) (autumn) and the mean FMR for the three seasons combined was 158+/-5 kJ d(-1) (equivalent to 1.33 kJ g(-)(1)d(-1) or 780 kJ kg(-0.)(75)d(-1)). The mean total body water was 83+/-2 g, equal to 68.5% of body weight. Mean water flux was 29+/-1 mL day(-1). Season, ambient temperature or sex did not affect any of the measured and estimated physiological variables, but body mass and total body water differed significantly between sexes and among seasons. Our study is the first to provide evidence for a constant FMR in a small mammal in three different seasons and despite different thermal conditions. This suggests that seasonal changes in climate are compensated for by behavioural and physiological adjustments such as huddling and torpor known to be employed extensively by sugar gliders in the wild.

  14. Can the cerebral metabolic rate of oxygen be estimated with near-infrared spectroscopy?

    Science.gov (United States)

    Boas, D. A.; Strangman, G.; Culver, J. P.; Hoge, R. D.; Jasdzewski, G.; Poldrack, R. A.; Rosen, B. R.; Mandeville, J. B.

    2003-08-01

    We have measured the changes in oxy-haemoglobin and deoxy-haemoglobin in the adult human brain during a brief finger tapping exercise using near-infrared spectroscopy (NIRS). The cerebral metabolic rate of oxygen (CMRO2) can be estimated from these NIRS data provided certain model assumptions. The change in CMRO2 is related to changes in the total haemoglobin concentration, deoxy-haemoglobin concentration and blood flow. As NIRS does not provide a measure of dynamic changes in blood flow during brain activation, we relied on a Windkessel model that relates dynamic blood volume and flow changes, which has been used previously for estimating CMRO2 from functional magnetic resonance imaging (fMRI) data. Because of the partial volume effect we are unable to quantify the absolute changes in the local brain haemoglobin concentrations with NIRS and thus are unable to obtain an estimate of the absolute CMRO2 change. An absolute estimate is also confounded by uncertainty in the flow-volume relationship. However, the ratio of the flow change to the CMRO2 change is relatively insensitive to these uncertainties. For the finger tapping task, we estimate a most probable flow-consumption ratio ranging from 1.5 to 3 in agreement with previous findings presented in the literature, although we cannot exclude the possibility that there is no CMRO2 change. The large range in the ratio arises from the large number of model parameters that must be estimated from the data. A more precise estimate of the flow-consumption ratio will require better estimates of the model parameters or flow information, as can be provided by combining NIRS with fMRI.

  15. Cold and Spleen-Qi Deficiency Patterns in Korean Medicine Are Associated with Low Resting Metabolic Rate

    Science.gov (United States)

    Bae, Kwang-Ho

    2017-01-01

    Background. Korean medicine (KM) patterns such as cold, heat, deficiency, and excess patterns have been associated with alterations of resting metabolic rate (RMR). However, the association of KM patterns with accurately measured body metabolic rate has not been investigated. Methods. Data on cold (CP), heat (HP), spleen-qi deficiency (SQDP), and kidney deficiency (KDP) patterns were extracted by a factor analysis of symptoms experienced by 954 participants. A multiple regression analysis was conducted to determine the association between KM patterns and RMR measured by an indirect calorimeter. Results. The CP and SQDP scores were higher and the HP score was lower in women. The HP and SQDP scores decreased with age, while KDP scores increased with age. A multiple regression analysis revealed that CP and SQDP scores were negatively associated with RMR independently of gender and age, and the CP remained significantly and negatively associated with RMR even after adjustment for fat-free mass. Conclusions. The underlying pathology of CP and SQDP might be associated with the body's metabolic rate. Further studies are needed to investigate the usefulness of RMR measurement in pattern identification and the association of CP and SQDP with metabolic disorders.

  16. Predator-induced phenotypic plasticity in metabolism and rate of growth: rapid adaptation to a novel environment.

    Science.gov (United States)

    Handelsman, Corey A; Broder, E Dale; Dalton, Christopher M; Ruell, Emily W; Myrick, Christopher A; Reznick, David N; Ghalambor, Cameron K

    2013-12-01

    Novel environments often impose directional selection for a new phenotypic optimum. Novel environments, however, can also change the distribution of phenotypes exposed to selection by inducing phenotypic plasticity. Plasticity can produce phenotypes that either align with or oppose the direction of selection. When plasticity and selection are parallel, plasticity is considered adaptive because it provides a better pairing between the phenotype and the environment. If the plastic response is incomplete and falls short of producing the optimum phenotype, synergistic selection can lead to genetic divergence and bring the phenotype closer to the optimum. In contrast, non-adaptive plasticity should increase the strength of selection, because phenotypes will be further from the local optimum, requiring antagonistic selection to overcome the phenotype-environment mismatch and facilitate adaptive divergence. We test these ideas by documenting predator-induced plasticity for resting metabolic rate and growth rate in populations of the Trinidadian guppy (Poecilia reticulata) adapted to high and low predation. We find reduced metabolic rates and growth rates when cues from a predator are present during development, a pattern suggestive of adaptive and non-adaptive plasticity, respectively. When we compared populations recently transplanted from a high-predation environment into four streams lacking predators, we found evidence for rapid adaptive evolution both in metabolism and growth rate. We discuss the implications for predicting how traits will respond to selection, depending on the type of plasticity they exhibit.

  17. The Protein Cost of Metabolic Fluxes: Prediction from Enzymatic Rate Laws and Cost Minimization.

    Science.gov (United States)

    Noor, Elad; Flamholz, Avi; Bar-Even, Arren; Davidi, Dan; Milo, Ron; Liebermeister, Wolfram

    2016-11-01

    Bacterial growth depends crucially on metabolic fluxes, which are limited by the cell's capacity to maintain metabolic enzymes. The necessary enzyme amount per unit flux is a major determinant of metabolic strategies both in evolution and bioengineering. It depends on enzyme parameters (such as kcat and KM constants), but also on metabolite concentrations. Moreover, similar amounts of different enzymes might incur different costs for the cell, depending on enzyme-specific properties such as protein size and half-life. Here, we developed enzyme cost minimization (ECM), a scalable method for computing enzyme amounts that support a given metabolic flux at a minimal protein cost. The complex interplay of enzyme and metabolite concentrations, e.g. through thermodynamic driving forces and enzyme saturation, would make it hard to solve this optimization problem directly. By treating enzyme cost as a function of metabolite levels, we formulated ECM as a numerically tractable, convex optimization problem. Its tiered approach allows for building models at different levels of detail, depending on the amount of available data. Validating our method with measured metabolite and protein levels in E. coli central metabolism, we found typical prediction fold errors of 4.1 and 2.6, respectively, for the two kinds of data. This result from the cost-optimized metabolic state is significantly better than randomly sampled metabolite profiles, supporting the hypothesis that enzyme cost is important for the fitness of E. coli. ECM can be used to predict enzyme levels and protein cost in natural and engineered pathways, and could be a valuable computational tool to assist metabolic engineering projects. Furthermore, it establishes a direct connection between protein cost and thermodynamics, and provides a physically plausible and computationally tractable way to include enzyme kinetics into constraint-based metabolic models, where kinetics have usually been ignored or oversimplified.

  18. Metabolic and organ mass responses to selection for high growth rates in the domestic chicken (Gallus domesticus).

    Science.gov (United States)

    Konarzewski, M; Gavin, A; McDevitt, R; Wallis, I R

    2000-01-01

    Evolutionary hypotheses suggest that higher rates of postembryonic development in birds should either lower the resting metabolic rate (RMR) in a trade-off between the costs of growth and maintenance or increase RMR because of a buildup of metabolic machinery. Furthermore, some suggest that higher rates of postembryonic development in birds should reduce peak metabolic rate (PMR) through delayed tissue maturation and/or an increased energy allocation to organ growth. We studied this by comparing metabolic rates and organ sizes of fast-growing meat-type chickens (broilers) with those of birds from a laying strain, which grow much slower. During the first week of life, despite growing six times faster, the RMR of the broiler chickens was lower than that of birds of the laying strain. The difference between strains in RMR disappeared thereafter, even though broilers continued to grow twice as fast as layers. The differences between strains in growth rate during the first week after hatching were not reflected in similar differences in the relative masses of the heart, liver, and small intestine. However, broilers had heavier intestines once they reached a body mass of 80 g. In contrast, broilers had relatively smaller brains than did layers. There was a positive correlation, over both strains, between RMR and the masses of leg muscles, intestine, and liver. Furthermore, despite delayed maturation of muscle tissue, broilers exhibited significantly higher PMR. We hypothesize that a balance between the larger relative muscle mass but lower muscle maturation level explains this high PMR. Another correlation, between leg muscle mass and PMR, partly explained the positive correlation between RMR and PMR.

  19. Neuropsychiatry of the basal ganglia

    OpenAIRE

    Ring, H.; Serra-Mestres, J

    2002-01-01

    This review aims to relate recent findings describing the role and neural connectivity of the basal ganglia to the clinical neuropsychiatry of basal ganglia movement disorders and to the role of basal ganglia disturbances in "psychiatric"' states. Articles relating to the relevant topics were initially collected through MEDLINE and papers relating to the clinical conditions discussed were also reviewed. The anatomy and connections of the basal ganglia indicate that these structures are import...

  20. Ventilation rates and activity levels of juvenile jumbo squid under metabolic suppression in the oxygen minimum zone.

    Science.gov (United States)

    Trübenbach, Katja; Pegado, Maria R; Seibel, Brad A; Rosa, Rui

    2013-02-01

    The Humboldt (jumbo) squid, Dosidicus gigas, is a part-time resident of the permanent oxygen minimum zone (OMZ) in the Eastern Tropical Pacific and, thereby, it encounters oxygen levels below its critical oxygen partial pressure. To better understand the ventilatory mechanisms that accompany the process of metabolic suppression in these top oceanic predators, we exposed juvenile D. gigas to the oxygen levels found in the OMZ (1% O(2), 1 kPa, 10 °C) and measured metabolic rate, activity cycling patterns, swimming mode, escape jet (burst) frequency, mantle contraction frequency and strength, stroke volume and oxygen extraction efficiency. In normoxia, metabolic rate varied between 14 and 29 μmol O(2) g(-1) wet mass h(-1), depending on the level of activity. The mantle contraction frequency and strength were linearly correlated and increased significantly with activity level. Additionally, an increase in stroke volume and ventilatory volume per minute was observed, followed by a mantle hyperinflation process during high activity periods. Squid metabolic rate dropped more than 75% during exposure to hypoxia. Maximum metabolic rate was not achieved under such conditions and the metabolic scope was significantly decreased. Hypoxia changed the relationship between mantle contraction strength and frequency from linear to polynomial with increasing activity, indicating that, under hypoxic conditions, the jumbo squid primarily increases the strength of mantle contraction and does not regulate its frequency. Under hypoxia, jumbo squid also showed a larger inflation period (reduced contraction frequency) and decreased relaxed mantle diameter (shortened diffusion pathway), which optimize oxygen extraction efficiency (up to 82%/34%, without/with consideration of 60% potential skin respiration). Additionally, they breathe 'deeply', with more powerful contractions and enhanced stroke volume. This deep-breathing behavior allows them to display a stable ventilatory volume per

  1. Dissolved Organic Nitrogen Inputs from Wastewater Treatment Plant Effluents Increase Responses of Planktonic Metabolic Rates to Warming.

    Science.gov (United States)

    Vaquer-Sunyer, Raquel; Conley, Daniel J; Muthusamy, Saraladevi; Lindh, Markus V; Pinhassi, Jarone; Kritzberg, Emma S

    2015-10-06

    Increased anthropogenic pressures on coastal marine ecosystems in the last century are threatening their biodiversity and functioning. Global warming and increases in nutrient loadings are two major stressors affecting these systems. Global warming is expected to increase both atmospheric and water temperatures and increase precipitation and terrestrial runoff, further increasing organic matter and nutrient inputs to coastal areas. Dissolved organic nitrogen (DON) concentrations frequently exceed those of dissolved inorganic nitrogen in aquatic systems. Many components of the DON pool have been shown to supply nitrogen nutrition to phytoplankton and bacteria. Predictions of how global warming and eutrophication will affect metabolic rates and dissolved oxygen dynamics in the future are needed to elucidate their impacts on biodiversity and ecosystem functioning. Here, we experimentally determine the effects of simultaneous DON additions and warming on planktonic community metabolism in the Baltic Sea, the largest coastal area suffering from eutrophication-driven hypoxia. Both bacterioplankton community composition and metabolic rates changed in relation to temperature. DON additions from wastewater treatment plant effluents significantly increased the activation energies for community respiration and gross primary production. Activation energies for community respiration were higher than those for gross primary production. Results support the prediction that warming of the Baltic Sea will enhance planktonic respiration rates faster than it will for planktonic primary production. Higher increases in respiration rates than in production may lead to the depletion of the oxygen pool, further aggravating hypoxia in the Baltic Sea.

  2. Saturation-recovery metabolic-exchange rate imaging with hyperpolarized [1-13C] pyruvate using spectral-spatial excitation.

    Science.gov (United States)

    Schulte, Rolf F; Sperl, Jonathan I; Weidl, Eliane; Menzel, Marion I; Janich, Martin A; Khegai, Oleksandr; Durst, Markus; Ardenkjaer-Larsen, Jan Henrik; Glaser, Steffen J; Haase, Axel; Schwaiger, Markus; Wiesinger, Florian

    2013-05-01

    Within the last decade hyperpolarized [1-13C] pyruvate chemical-shift imaging has demonstrated impressive potential for metabolic MR imaging for a wide range of applications in oncology, cardiology, and neurology. In this work, a highly efficient pulse sequence is described for time-resolved, multislice chemical shift imaging of the injected substrate and obtained downstream metabolites. Using spectral-spatial excitation in combination with single-shot spiral data acquisition, the overall encoding is evenly distributed between excitation and signal reception, allowing the encoding of one full two-dimensional metabolite image per excitation. The signal-to-noise ratio can be flexibly adjusted and optimized using lower flip angles for the pyruvate substrate and larger ones for the downstream metabolites. Selectively adjusting the excitation of the down-stream metabolites to 90° leads to a so-called "saturation-recovery" scheme with the detected signal content being determined by forward conversion of the available pyruvate. In case of repetitive excitations, the polarization is preserved using smaller flip angles for pyruvate. Metabolic exchange rates are determined spatially resolved from the metabolite images using a simplified two-site exchange model. This novel contrast is an important step toward more quantitative metabolic imaging. Goal of this work was to derive, analyze, and implement this "saturation-recovery metabolic exchange rate imaging" and demonstrate its capabilities in four rats bearing subcutaneous tumors.

  3. Metabolic rate variation over adult lifetime in the butterfly Vanessa cardui (Nymphalidae: Nymphalinae): aging, feeding, and repeatability.

    Science.gov (United States)

    Woods, William A; Wood, C A L; Ebersole, John; Stevenson, R D

    2010-01-01

    Questions about the adaptive importance of metabolic rate can be approached only when measurements of differences between individuals are repeatable. We made daily measurements of CO(2) production, body mass, and food uptake over the adult life span of unmated Vanessa cardui kept under constant environmental conditions in both fed and unfed treatments. Mass and CO(2) production generally declined with age in both treatments, though with much day-to-day variability in the fed treatment. For the full samples, metabolic rate was repeatable for the unfed treatment (repeatability r = 0.60) but not for the fed treatment (r = 0.03). Differences between fed and unfed individuals of the same age range were repeatable for the unfed treatment (r = 0.39) but not for the fed treatment (r = -0.20). Removing age effects on CO(2) production yielded still higher repeatability in the unfed treatment (r = 0.83), though not in fed butterflies of the same age range (r = -0.02). However, repeatability of CO(2) production of fed butterflies increased sharply with age, rising to 0.82 for butterflies age 8-10 d. Although food uptake mass was repeatable (r = 0.52), feeding history explained little variation in CO(2) production. We conclude that for V. cardui and possibly for other insects of similar feeding habit, variation in metabolic rate between individuals is best represented by measurements of unfed individuals of the same age or of older fed individuals.

  4. Implications of progesterone metabolism in MA-10 cells for accurate measurement of the rate of steroidogenesis.

    NARCIS (Netherlands)

    Rommerts, F.F.; King, S.R.; Span, P.N.

    2001-01-01

    In virtually all studies with MA-10 cells, progesterone RIAs have been used to measure steroid synthesis. To test whether progesterone is a stable end product, we investigated the metabolism of added tritiated progesterone and pregnenolone in MA-10 cells over a period of 3 h. Steroids were then extr

  5. Conservation of the glucan phosphatase laforin is linked to rates of molecular evolution and the glucan metabolism of the organism

    Directory of Open Access Journals (Sweden)

    Pace Rachel M

    2009-06-01

    Full Text Available Abstract Background Lafora disease (LD is a fatal autosomal recessive neurodegenerative disease. A hallmark of LD is cytoplasmic accumulation of insoluble glucans, called Lafora bodies (LBs. Mutations in the gene encoding the phosphatase laforin account for ~50% of LD cases, and this gene is conserved in all vertebrates. We recently demonstrated that laforin is the founding member of a unique class of phosphatases that dephosphorylate glucans. Results Herein, we identify laforin orthologs in a protist and two invertebrate genomes, and report that laforin is absent in the vast majority of protozoan genomes and it is lacking in all other invertebrate genomes sequenced to date. We biochemically characterized recombinant proteins from the sea anemone Nematostella vectensis and the amphioxus Branchiostoma floridae to demonstrate that they are laforin orthologs. We demonstrate that the laforin gene has a unique evolutionary lineage; it is conserved in all vertebrates, a subclass of protists that metabolize insoluble glucans resembling LBs, and two invertebrates. We analyzed the intron-exon boundaries of the laforin genes in each organism and determine, based on recently published reports describing rates of molecular evolution in Branchiostoma and Nematostella, that the conservation of laforin is linked to the molecular rate of evolution and the glucan metabolism of an organism. Conclusion Our results alter the existing view of glucan phosphorylation/dephosphorylation and strongly suggest that glucan phosphorylation is a multi-Kingdom regulatory mechanism, encompassing at least some invertebrates. These results establish boundaries concerning which organisms contain laforin. Laforin is conserved in all vertebrates, it has been lost in the vast majority of lower organisms, and yet it is an ancient gene that is conserved in a subset of protists and invertebrates that have undergone slower rates of molecular evolution and/or metabolize a carbohydrate

  6. Physical activity, heart rate, metabolic profile, and estradiol in premenopausal women

    DEFF Research Database (Denmark)

    Emaus, Aina; Veierød, Marit B; Furberg, Anne-Sofie;

    2008-01-01

    syndrome (zMS); total cholesterol-high-density lipoprotein-cholesterol (HDL-C) ratio, insulin resistance, total fat tissue, BP, and triglycerides] was defined. Linear regression and linear mixed models were used, and confounding factors were tested. RESULTS: Physically active women had lower fat percentage...... were also found for fat tissue, total cholesterol-HDL-C ratio, insulin resistance, and triglycerides. A dose-response relationship was observed among the three levels of LPA and HR and zMS (Ptrend = 0.03 for LPA; Ptrend = 0.004 for HR). Women in the highest tertile of the clustered metabolic risk score......PURPOSE: To study whether physical inactive women with a tendency to develop metabolic syndrome have high levels of 17beta-estradiol (E2) of importance for breast cancer risk. METHODS: Two hundred and four healthy women of reproductive age were assessed for self-reported leisure-time physical...

  7. Genetic modulation of energy metabolism in birds through mitochondrial function

    NARCIS (Netherlands)

    Tieleman, B. Irene; Versteegh, Maaike A.; Fries, Anthony; Helm, Barbara; Dingemanse, Niels J.; Gibbs, H. Lisle; Williams, Joseph B.

    2009-01-01

    Despite their central importance for the evolution of physiological variation, the genetic mechanisms that determine energy expenditure in animals have largely remained unstudied. We used quantitative genetics to confirm that both mass-specific and whole-organism basal metabolic rate (BMR) were heri

  8. The Effect of the Protease Inhibitor Ritonavir on the Rate of Metabolism of Midazolam

    Science.gov (United States)

    2000-01-03

    all tissues in the body are capable of some metabolism of xenobiotics, the liver is the main site of biotransformation ( Katzung , 1998). The system...second oxygen is transferred to the substrate ( Katzung , 1998). The P450 system is a super-family of related enzymes, all with unique functions that...involves the incident itself (Omoigui, 1995). Antiviral. A substance that has properties that are aimed at preventing viral replication ( Katzung

  9. Aspartic acid concentrations in coral skeletons as recorders of past disturbances of metabolic rates

    Science.gov (United States)

    Gupta, Lallan P.; Suzuki, Atsushi; Kawahata, Hodaka

    2006-11-01

    The composition of total hydrolysable amino acids (THAAs) in a skeleton of the coral Porites australiensis, collected from Ishigaki Island, Japan, was examined in order to determine whether amino acids (AA) can be used as biomarkers of past changes in coral physiology (metabolism). Micro-samples, corresponding to a time resolution of 1 month, were collected along the growth axis of the coral. Of the 20 AAs analyzed, aspartic acid (Asp) was the most abundant, and its mole concentration relative to the sum of all other AAs (mole%Asp) showed a clear seasonal pattern of low content during winters and high during summers. A growth disturbance in the coral skeleton during 1988 1990, shown by X-ray scans and oxygen and carbon stable isotope data, was marked by a high mole%Asp ratio. Variability in carbon isotope data has often been attributed to metabolic effects, or changes in the isotopic composition of seawater, or both. The changes in mole%Asp shown here suggest that metabolic effects are mainly responsible for sharp changes in carbon isotope profiles during periods of growth disturbance.

  10. Ivabradine and metoprolol differentially affect cardiac glucose metabolism despite similar heart rate reduction in a mouse model of dyslipidemia.

    Science.gov (United States)

    Vaillant, Fanny; Lauzier, Benjamin; Ruiz, Matthieu; Shi, Yanfen; Lachance, Dominic; Rivard, Marie-Eve; Bolduc, Virginie; Thorin, Eric; Tardif, Jean-Claude; Des Rosiers, Christine

    2016-10-01

    While heart rate reduction (HRR) is a target for the management of patients with heart disease, contradictory results were reported using ivabradine, which selectively inhibits the pacemaker If current, vs. β-blockers like metoprolol. This study aimed at testing whether similar HRR with ivabradine vs. metoprolol differentially modulates cardiac energy substrate metabolism, a factor determinant for cardiac function, in a mouse model of dyslipidemia (hApoB(+/+);LDLR(-/-)). Following a longitudinal study design, we used 3- and 6-mo-old mice, untreated or treated for 3 mo with ivabradine or metoprolol. Cardiac function was evaluated in vivo and ex vivo in working hearts perfused with (13)C-labeled substrates to assess substrate fluxes through energy metabolic pathways. Compared with 3-mo-old, 6-mo-old dyslipidemic mice had similar cardiac hemodynamics in vivo but impaired (P ivabradine-treated hearts displayed significantly higher stroke volume values and glycolysis vs. their metoprolol-treated counterparts ex vivo, values for the ivabradine group being often not significantly different from 3-mo-old mice. Further analyses highlighted additional significant cardiac alterations with disease progression, namely in the total tissue level of proteins modified by O-linked N-acetylglucosamine (O-GlcNAc), whose formation is governed by glucose metabolism via the hexosamine biosynthetic pathway, which showed a similar pattern with ivabradine vs. metoprolol treatment. Collectively, our results emphasize the implication of alterations in cardiac glucose metabolism and signaling linked to disease progression in our mouse model. Despite similar HRR, ivabradine, but not metoprolol, preserved cardiac function and glucose metabolism during disease progression.

  11. Glutamine metabolism in uricotelic species: variation in skeletal muscle glutamine synthetase, glutaminase, glutamine levels and rates of protein synthesis.

    Science.gov (United States)

    Watford, Malcolm; Wu, Guoyao

    2005-04-01

    High intracellular glutamine levels have been implicated in promoting net protein synthesis and accretion in mammalian skeletal muscle. Little is known regarding glutamine metabolism in uricotelic species but chicken breast muscle exhibits high rates of protein accretion and would be predicted to maintain high glutamine levels. However, chicken breast muscle expresses high glutaminase activity and here we report that chicken breast muscle also expresses low glutamine synthetase activity (0.07+/-0.01 U/g) when compared to leg muscle (0.50+/-0.04 U/g). Free glutamine levels were 1.38+/-0.09 and 9.69+/-0.12 nmol/mg wet weight in breast and leg muscles of fed chickens, respectively. Glutamine levels were also lower in dove breast muscle (4.82+/-0.35 nmol/mg wet weight) when compared to leg muscle (16.2+/-1.0 nmol/mg wet weight) and much lower (1.80+/-0.46 nmol/mg wet weight) in lizard leg muscle. In fed chickens, rates of fractional protein synthesis were higher in leg than in breast muscle, and starvation (48 h) resulted in a decrease in both glutamine content and rate of protein synthesis in leg muscle. Thus, although tissue-specific glutamine metabolism in uricotelic species differs markedly from that in ureotelic animals, differences in rates of skeletal muscle protein synthesis are associated with corresponding differences in intramuscular glutamine content.

  12. Vismodegib in basal cell carcinoma.

    Science.gov (United States)

    Amaria, R N; Bowles, D W; Lewis, K D; Jimeno, A

    2012-07-01

    Vismodegib is a novel, small-molecule inhibitor of smoothened, a key component of the hedgehog signaling pathway. Increased hedgehog pathway signaling is critical in the development of hereditary and spontaneous basal cell carcinomas of the skin, and has been implicated in the development of a number of other tumors. In preclinical models, vismodegib demonstrated potent antitumor activity in hedgehog-dependent tumors, particularly basal cell carcinomas. Clinically, phase I and II studies showed dramatic anticancer activity in patients with advanced basal cell carcinomas. In January 2012, vismodegib was approved by the FDA for the treatment of unresectable or metastatic basal cell carcinomas of the skin.

  13. Thermal dependence of clearance and metabolic rates in slow- and fast-growing spats of manila clam Ruditapes philippinarum.

    Science.gov (United States)

    Tamayo, David; Ibarrola, Irrintzi; Navarro, Enrique

    2013-10-01

    Thermal dependence of clearance rate (CR: l h(-1)), standard (SMR: J h(-1)) and routine metabolic rates (RMR: J h(-1)), were analyzed in fast (F)- and slow (S)-growing juveniles of the clam Ruditapes philippinarum. Physiological rates were measured at the maintenance temperature (17 °C), and compared with measurements performed at 10 and 24 °C after 16 h and 14 days to analyze acute and acclimated responses, respectively. Metabolic rates (both RMR and SMR) differed significantly between F and S seeds, irrespective of temperature. Mass-specific CRs were not different for F and S seeds but were significantly higher in F clams for rates standardized according to allometric size-scaling rules. Acute thermal dependency of CR was equal for F and S clams: mean Q 10 were ≈3 and 2 in temperature ranges of 10-17 and 17-24 °C, respectively. CR did not change after 2 weeks of acclimation to temperatures. Acute thermal effects on SMR were similar in both groups (Q 10 ≈ 1 and 1.6 in temperature ranges of 10-17 and 17-24 °C, respectively). Large differences between groups were found in the acute thermal dependence of RMR: Q 10 in F clams (≈1.2 and 1.9 at temperature ranges of 10-17 and 17-24 °C, respectively) were similar to those found for SMR (Q 10 = 1.0 and 1.7). In contrast, RMR of S clams exhibited maximum thermal dependence (Q 10 = 3.1) at 10-17 °C and become depressed at higher temperatures (Q 10 = 0.9 at 17-24 °C). A recovery of RMR in S clams was recorded upon acclimation to 24 °C. Contrasting metabolic patterns between fast and slow growers are interpreted as a consequence of differential thermal sensitivity of the fraction of metabolism associated to food processing and assimilation.

  14. Growth hormone transgenic tilapia (Oreochromis sp.) compensate for increased metabolic rate to preserve exercise performance and hypoxia tolerance

    DEFF Research Database (Denmark)

    McKenzie, D.J.; Martínez, R.; Morales, A.

    2001-01-01

    of the exponential relationship between U and O2 uptake back to a notional stationary baseline was taken as an estimate of maintenance metabolism. This was significantly higher in transgenic vs. wild-type fish (8.63 ± 0.86 vs. 5.39 ± 0.27 mmol O2 kg-1 h-1, respectively). However, maximum O2 uptake was also slightly......Transgenic tilapia hybrids (Oreochromis mossambicus × O. hornorum) carrying a single copy of a homologous cDNA growth hormone exhibit higher growth rates than their wild-type conspecifics (Martinez et al. 1999). Swimming respirometry was employed to determine whether the increased growth rate...... was linked to elevated rates of maintenance metabolism in transgenics, and if this, in turn, influenced their scope to increase O2 uptake and perform exercise or their ability to maintain O2 uptake during progressive hypoxia. Individual transgenics or wild-types, of similar mass and length (60.0 ± 10 g...

  15. Environment and feeding change the ability of heart rate to predict metabolism in resting Steller sea lions (Eumetopias jubatus).

    Science.gov (United States)

    Young, Beth L; Rosen, David A S; Haulena, Martin; Hindle, Allyson G; Trites, Andrew W

    2011-01-01

    The ability to use heart rate (fh) to predict oxygen consumption rates ([Formula: see text]) in Steller sea lions and other pinnipeds has been investigated in fasting animals. However, it is unknown whether established fh:[Formula: see text] relationships hold under more complex physiological situations, such as when animals are feeding or digesting. We assessed whether fh could accurately predict [Formula: see text] in trained Steller sea lions while fasting and after being fed. Using linear mixed-effects models, we derived unique equations to describe the fh:[Formula: see text] relationship for fasted sea lions resting on land and in water. Feeding did not significantly change the fh:[Formula: see text] relationship on land. However, Steller sea lions in water displayed a different fh:[Formula: see text] relationship after consuming a 4-kg meal compared with the fasting condition. Incorporating comparable published fh:[Formula: see text] data from Steller sea lions showed a distinct effect of feeding after a 6-kg meal. Ultimately, our study illustrated that both feeding and physical environment are statistically relevant when deriving [Formula: see text] from telemetered fh, but that only environment affects the practical ability to predict metabolism from fh. Updating current bioenergetic models with data gathered using these predictive fh:[Formula: see text] equations will yield more accurate estimates of metabolic rates of free-ranging Steller sea lions under a variety of physiological, behavioral, and environmental states.

  16. High metabolic demand in neural tissues: Information and control theory perspectives on the synergism between rate and stability.

    Science.gov (United States)

    Wallace, Rodrick

    2016-11-21

    Evolutionary process has been selected for inherently unstable systems in higher animals that can react swiftly to changing patterns of threat or opportunity, for example blood pressure, the immune response, and gene expression. However, these require continual strict regulation: uncontrolled blood pressure is fatal, immune cells can attack 'self' tissues, and improper gene expression triggers developmental disorders. Consciousness in particular demands high rates of metabolic free energy to both operate and regulate the fundamental biological machinery: both the 'stream of consciousness' and the 'riverbanks' that confine it to useful realms are constructed and reconstructed moment-by-moment in response to highly dynamic internal and environmental circumstances. We develop powerful necessary conditions models for such phenomena based on the Data Rate Theorem linking control and information theories in the context of inherent instability. The synergism between conscious action and its regulation underlies the ten-fold higher rate of metabolic energy consumption in human neural tissues and implies a close, culturally modulated relation between sleep disorders and certain psychopathologies.

  17. Is Mass-based Metabolism Rate Proportional to Surface Area in Plant Leaves? A Data Re-analysis

    Institute of Scientific and Technical Information of China (English)

    Dongmei Jin; Yiqiang Dai; Li Sun; Shucun Sun

    2008-01-01

    We re-analyzed two large published databases on leaf traits of plant species from seven different biomes, and determined the scaling relationship between leaf metabolism rate (mass-based photosynthesis capacity, Amass, and mass-based dark respiration, Rdmass) and specific leaf area (SLA) across biomes, using a standardized major axis (SMA) method. Overall pooled data produced a scaling exponent of 1.33 for the relationship between Amass and SLA, significantly larger than 1.0; and 1.04 between Rdmass and SLA. The scaling exponent of the relationship between Amass and SLA ranged between 1.23 (in tropical forest) and 1.66 (in alpine biome), and it was significantly larger in alpine (1.66) and grass/meadow (1.52) biomes than in tropical forest (1.23) and wetland (1.27). The exponent of the relationship between Rdmass and SLA, however,was much smaller in wetland (1.05) than in temperate forest (1.29) and tropical rainforest (1.65). In general, the predicated universal scaling relationship that the mass-based metabolism rate should be proportional to surface area in organisms is not applicable at the leaf-level in plants. Rather, the large slope difference of the relationship between leaf metabolism rate and SLA found among biomes indicates that the strength of the selective forces driving the scaling relationship is different among the biomes. The result basically suggests the importance of increasing SLA to plant carbon gain in stressful environments and to carbon loss in favorable habitats, and therefore has an important implication for survival strategies of plants in different biomes.

  18. Atmospheric oxygen level affects growth trajectory, cardiopulmonary allometry and metabolic rate in the American alligator (Alligator mississippiensis)

    Science.gov (United States)

    Owerkowicz, Tomasz; Elsey, Ruth M.; Hicks, James W.

    2009-01-01

    Summary Recent palaeoatmospheric models suggest large-scale fluctuations in ambient oxygen level over the past 550 million years. To better understand how global hypoxia and hyperoxia might have affected the growth and physiology of contemporary vertebrates, we incubated eggs and raised hatchlings of the American alligator. Crocodilians are one of few vertebrate taxa that survived these global changes with distinctly conservative morphology. We maintained animals at 30°C under chronic hypoxia (12% O2), normoxia (21% O2) or hyperoxia (30% O2). At hatching, hypoxic animals were significantly smaller than their normoxic and hyperoxic siblings. Over the course of 3 months, post-hatching growth was fastest under hyperoxia and slowest under hypoxia. Hypoxia, but not hyperoxia, caused distinct scaling of major visceral organs–reduction of liver mass, enlargement of the heart and accelerated growth of lungs. When absorptive and post-absorptive metabolic rates were measured in juvenile alligators, the increase in oxygen consumption rate due to digestion/absorption of food was greatest in hyperoxic alligators and smallest in hypoxic ones. Hyperoxic alligators exhibited the lowest breathing rate and highest oxygen consumption per breath. We suggest that, despite compensatory cardiopulmonary remodelling, growth of hypoxic alligators is constrained by low atmospheric oxygen supply, which may limit their food utilisation capacity. Conversely, the combination of elevated metabolism and low cost of breathing in hyperoxic alligators allows for a greater proportion of metabolised energy to be available for growth. This suggests that growth and metabolic patterns of extinct vertebrates would have been significantly affected by changes in the atmospheric oxygen level. PMID:19376944

  19. Toxic effects of linear alkylbenzene sulfonate on metabolic activity, growth rate, and microcolony formation of Nitrosomonas and Nitrosospira strains.

    Science.gov (United States)

    Brandt, K K; Hesselsøe, M; Roslev, P; Henriksen, K; Sørensen, J

    2001-06-01

    Strong inhibitory effects of the anionic surfactant linear alkylbenzene sulfonate (LAS) on four strains of autotrophic ammonia-oxidizing bacteria (AOB) are reported. Two Nitrosospira strains were considerably more sensitive to LAS than two Nitrosomonas strains were. Interestingly, the two Nitrosospira strains showed a weak capacity to remove LAS from the medium. This could not be attributed to adsorption or any other known physical or chemical process, suggesting that biodegradation of LAS took place. In each strain, the metabolic activity (50% effective concentration [EC(50)], 6 to 38 mg liter(-1)) was affected much less by LAS than the growth rate and viability (EC(50), 3 to 14 mg liter(-1)) were. However, at LAS levels that inhibited growth, metabolic activity took place only for 1 to 5 days, after which metabolic activity also ceased. The potential for adaptation to LAS exposure was investigated with Nitrosomonas europaea grown at a sublethal LAS level (10 mg liter(-1)); compared to control cells, preexposed cells showed severely affected cell functions (cessation of growth, loss of viability, and reduced NH(4)(+) oxidation activity), demonstrating that long-term incubation at sublethal LAS levels was also detrimental. Our data strongly suggest that AOB are more sensitive to LAS than most heterotrophic bacteria are, and we hypothesize that thermodynamic constraints make AOB more susceptible to surfactant-induced stress than heterotrophic bacteria are. We further suggest that AOB may comprise a sensitive indicator group which can be used to determine the impact of LAS on microbial communities.

  20. Extraction of elementary rate constants from global network analysis of E. coli central metabolism

    Directory of Open Access Journals (Sweden)

    Broderick Gordon

    2008-05-01

    Full Text Available Abstract Background As computational performance steadily increases, so does interest in extending one-particle-per-molecule models to larger physiological problems. Such models however require elementary rate constants to calculate time-dependent rate coefficients under physiological conditions. Unfortunately, even when in vivo kinetic data is available, it is often in the form of aggregated rate laws (ARL that do not specify the required elementary rate constants corresponding to mass-action rate laws (MRL. There is therefore a need to develop a method which is capable of automatically transforming ARL kinetic information into more detailed MRL rate constants. Results By incorporating proteomic data related to enzyme abundance into an MRL modelling framework, here we present an efficient method operating at a global network level for extracting elementary rate constants from experiment-based aggregated rate law (ARL models. The method combines two techniques that can be used to overcome the difficult properties in parameterization. The first, a hybrid MRL/ARL modelling technique, is used to divide the parameter estimation problem into sub-problems, so that the parameters of the mass action rate laws for each enzyme are estimated in separate steps. This reduces the number of parameters that have to be optimized simultaneously. The second, a hybrid algebraic-numerical simulation and optimization approach, is used to render some rate constants identifiable, as well as to greatly narrow the bounds of the other rate constants that remain unidentifiable. This is done by incorporating equality constraints derived from the King-Altman and Cleland method into the simulated annealing algorithm. We apply these two techniques to estimate the rate constants of a model of E. coli glycolytic pathways. The simulation and statistical results show that our innovative method performs well in dealing with the issues of high computation cost, stiffness, local

  1. Relationship Between Metabolic Rate and Organ Size in Brandt's Voles (Microtus brandti)%内蒙古草原布氏田鼠代谢率与身体器官的关系

    Institute of Scientific and Technical Information of China (English)

    宋志刚; 王德华

    2003-01-01

    动物代谢率存在差异的原因及其意义是进化生理学的一个核心问题.为了解代谢率的影响因素和功能意义,我们测定了不同驯化条件下布氏田鼠(Microtus brandti)的基础代谢率 (basal metabolic rate, BMR) 、日能量消耗(daily energy expenditure, DEE)和冷诱导的最大代谢率 (maximum metabolic rate, MMR) ,分析了动物体内11种器官、组织的重量与代谢率的关系.结果显示,排除温度、光照、食物质量和体重的影响后,BMR与心脏、肝脏、肾脏、胃和盲肠相关;DEE与心脏、肾脏、胃和盲肠相关;MMR与脑重显著负相关.这表明:在布氏田鼠体内存在着代谢活性器官,主要包括心脏、肝脏、肾脏、胃和盲肠,这些器官对BMR有较大的贡献.动物的能量周转水平与体内 "代谢机器"(metabolic machinery)的大小相关连,主要受到心脏、肾脏、胃和盲肠的影响.最大代谢率受脑重的影响.BMR与MMR的相关性不显著,而BMR与DEE的相关性显著,说明较高的BMR有助于维持较高的DEE,但不能维持较高的MMR.

  2. Effects of salinity on metabolic rate and branchial expression of genes involved in ion transport and metabolism in Mozambique tilapia (Oreochromis mossambicus).

    Science.gov (United States)

    Zikos, Aris; Seale, Andre P; Lerner, Darren T; Grau, E Gordon; Korsmeyer, Keith E

    2014-12-01

    This study investigated the effects of two rearing salinities, and acute salinity transfer, on the energetic costs of osmoregulation and the expression of metabolic and osmoregulatory genes in the gill of Mozambique tilapia. Using automated, intermittent-flow respirometry, measured standard metabolic rates (SMRs) of tilapia reared in seawater (SW, 130 mg O₂ kg⁻¹ h⁻¹) were greater than those reared in fresh water (FW, 103 mg O₂ kg⁻¹ h⁻¹), when normalized to a common mass of 0.05 kg and at 25±1°C. Transfer from FW to 75% SW increased SMR within 18h, to levels similar to SW-reared fish, while transfer from SW to FW decreased SMR to levels similar to FW-reared fish. Branchial gene expression of Na⁺-K⁺-2Cl⁻ cotransporter (NKCC), an indicator of SW-type mitochondria-rich (MR) cells, was positively correlated with SMR, while Na⁺-Cl⁻ cotransporter (NCC), an indicator of FW-type MR cells, was negatively correlated. Principal Components Analysis also revealed that branchial expression of cytochrome c oxidase subunit IV (COX-IV), glycogen phosphorylase (GP), and a putative mitochondrial biogenesis regulator in fish, peroxisome proliferator-activated receptor γ coactivator 1α (PGC-1α), were correlated with a higher SMR, plasma osmolality, and environmental salinity, while expression of glycogen synthase (GS), PGC-1β, and nuclear respiratory factor 1 (NRF-1) had negative correlations. These results suggest that the energetic costs of osmoregulation are higher in SW than in FW, which may be related to the salinity-dependent differences in osmoregulatory mechanisms found in the gills of Mozambique tilapia.

  3. Water exchange rate in RAS and dietary inclusion of micro-minerals influence growth, body composition and mineral metabolism in common carp

    NARCIS (Netherlands)

    Antony Jesu Prabhu, P.; Kaushik, S.J.; Geurden, I.; Stouten, T.; Fontagné-dicharry, S.; Veron, V.; Mariojouls, C.; Verreth, J.A.J.; Eding, E.H.; Schrama, J.W.

    2017-01-01

    Recirculation aquaculture systems (RASs) operated at low water exchange rates are known to accumulate minerals in the water. This study examined the dietary mineral requirement and metabolism in common carp reared in RAS of contrasting water exchange rates. Two independent RAS (water exchange rates,

  4. Effect of Temperature on Precipitation Rate of Calcium Carbonate Produced through Microbial Metabolic Process of Bio Materials

    Directory of Open Access Journals (Sweden)

    Prima Yane Putri

    2016-09-01

    Full Text Available Concrete is the most widely used construction material in civil engineering. But plain concrete is a brittle material and has little resistance to cracking. The cracking in concrete promotes deterioration such as the corrosion of reinforcing rebar, therefore, repair in filling the crack is often carried out. Recently, repair methods using bio-based materials associated with microbial metabolic processes leading to precipitation of calcium carbonate have been intensively studied. In this study, influencing factors on the precipitation rate depending on the constituents of bio-based material comprising yeast, glucose and calcium acetate mixed in tris buffer solution was examined for improving the rate of initial reactions. In addition, effect of temperature change on the amount of calcium carbonate precipitation was also investigated. The precipitates were identified by X-ray diffraction. It was shown that the increase of temperature lead to a change on calcium carbonate precipitation and caused the pH decrease under 7.0.

  5. Short-term captivity influences maximal cold-induced metabolic rates and their repeatability in summer-acclimatized American goldfinches Spinus tristis

    Institute of Scientific and Technical Information of China (English)

    David L.SWANSON; Marisa O.KING

    2013-01-01

    Studies of metabolic variation in birds have involved both wild and captive individuals,but few studies have investigated whether captivity directly influences metabolic rates,despite such variation potentially confounding conclusions regarding how metabolic rates respond to the conditions under study.In addition,whether short-term captivity influences metabolic rate repeatability in birds is currently uninvestigated.In this study,we measured Msum (maximal cold-induced metabolic rates) in summer acclimatized American goldfinches Spinus tristis directly after capture from wild populations,after approximately 2 weeks of indoor captivity (Captive 1),and again after an additional 1-2 weeks of captivity (Captive 2).Msum increased significantly (16.9%) following the initial captive period,but remained stable thereafter.Body mass (Mb) also increased significantly (9.2%) during the initial captive period but remained stable thereafter,suggesting that muscle growth and/or remodeling of body composition produced the observed metabolic variation.Mb and Msum were not significantly repeatable between wild and Captive 1 birds,but were significantly repeatable between Captive 1 and Captive 2 groups.These data suggest that caution must be exercised when extrapolating metabolic rates from short-term captive to wild populations.In addition,Msum was a repeatable trait for birds under conditions where mean metabolic rates remained stable,but Msum repeatability disappeared during acclimation to conditions promoting phenotypically flexible metabolic responses.This suggests that the capacity for phenotypic flexibility varies among individuals,and such variation could have fitness consequences.

  6. The effects of laboratory housing and spatial enrichment on brain size and metabolic rate in the eastern mosquitofish, Gambusia holbrooki.

    Science.gov (United States)

    Turschwell, Mischa P; White, Craig R

    2016-01-21

    It has long been hypothesised that there is a functional correlation between brain size and metabolic rate in vertebrates. The present study tested this hypothesis in wild-caught adult mosquitofish Gambusia holbrooki by testing for an intra-specific association between resting metabolic rate (RMR) and brain size while controlling for variation in body size, and through the examination of the effects of spatial enrichment and laboratory housing on body mass-independent measures of brain size and RMR. Controlling for body mass, there was no relationship between brain size and RMR in wild-caught fish. Contrary to predictions, spatial enrichment caused a decrease in mass-independent brain size, highlighting phenotypic plasticity in the adult brain. As expected, after controlling for differences in body size, wild-caught fish had relatively larger brains than fish that had been maintained in the laboratory for a minimum of six weeks, but wild-caught fish also had significantly lower mass-independent RMR. This study demonstrates that an organisms' housing environment can cause significant plastic changes to fitness related traits including brain size and RMR. We therefore conclude that current standard laboratory housing conditions may cause captive animals to be non-representative of their wild counterparts, potentially undermining the transferability of previous laboratory-based studies of aquatic ectothermic vertebrates to wild populations.

  7. The effects of laboratory housing and spatial enrichment on brain size and metabolic rate in the eastern mosquitofish, Gambusia holbrooki

    Directory of Open Access Journals (Sweden)

    Mischa P. Turschwell

    2016-03-01

    Full Text Available It has long been hypothesised that there is a functional correlation between brain size and metabolic rate in vertebrates. The present study tested this hypothesis in wild-caught adult mosquitofish Gambusia holbrooki by testing for an intra-specific association between resting metabolic rate (RMR and brain size while controlling for variation in body size, and through the examination of the effects of spatial enrichment and laboratory housing on body mass-independent measures of brain size and RMR. Controlling for body mass, there was no relationship between brain size and RMR in wild-caught fish. Contrary to predictions, spatial enrichment caused a decrease in mass-independent brain size, highlighting phenotypic plasticity in the adult brain. As expected, after controlling for differences in body size, wild-caught fish had relatively larger brains than fish that had been maintained in the laboratory for a minimum of six weeks, but wild-caught fish also had significantly lower mass-independent RMR. This study demonstrates that an organisms' housing environment can cause significant plastic changes to fitness related traits including brain size and RMR. We therefore conclude that current standard laboratory housing conditions may cause captive animals to be non-representative of their wild counterparts, potentially undermining the transferability of previous laboratory-based studies of aquatic ectothermic vertebrates to wild populations.

  8. Effects of wastewater treatment plant effluent inputs on planktonic metabolic rates and microbial community composition in the Baltic Sea

    Science.gov (United States)

    Vaquer-Sunyer, Raquel; Reader, Heather E.; Muthusamy, Saraladevi; Lindh, Markus V.; Pinhassi, Jarone; Conley, Daniel J.; Kritzberg, Emma S.

    2016-08-01

    The Baltic Sea is the world's largest area suffering from eutrophication-driven hypoxia. Low oxygen levels are threatening its biodiversity and ecosystem functioning. The main causes for eutrophication-driven hypoxia are high nutrient loadings and global warming. Wastewater treatment plants (WWTP) contribute to eutrophication as they are important sources of nitrogen to coastal areas. Here, we evaluated the effects of wastewater treatment plant effluent inputs on Baltic Sea planktonic communities in four experiments. We tested for effects of effluent inputs on chlorophyll a content, bacterial community composition, and metabolic rates: gross primary production (GPP), net community production (NCP), community respiration (CR) and bacterial production (BP). Nitrogen-rich dissolved organic matter (DOM) inputs from effluents increased bacterial production and decreased primary production and community respiration. Nutrient amendments and seasonally variable environmental conditions lead to lower alpha-diversity and shifts in bacterial community composition (e.g. increased abundance of a few cyanobacterial populations in the summer experiment), concomitant with changes in metabolic rates. An increase in BP and decrease in CR could be caused by high lability of the DOM that can support secondary bacterial production, without an increase in respiration. Increases in bacterial production and simultaneous decreases of primary production lead to more carbon being consumed in the microbial loop, and may shift the ecosystem towards heterotrophy.

  9. The rate of starch hydrolysis in vitro does not predict the metabolic responses to legumes in vivo.

    Science.gov (United States)

    O'Dea, K; Wong, S

    1983-09-01

    The aim of this study was to determine whether legumes in a physical form which is rapidly digested in vitro give rise to proportionately greater metabolic responses in vivo than legumes which are slowly digested in vitro. Samples of cooked whole and ground lentils were incubated in vitro with pancreatic amylase for 30 min and the percentage starch hydrolysis determined. Grinding the lentils before cooking resulted in a 5-fold increase in the rate of starch hydrolysis (whole lentils 12.1%, ground lentils 60.9%). For the in vivo studies six healthy, young, lean subjects consumed two test meals containing 50 g starch: whole lentils and lentils that had been ground finely before cooking. Postprandial glucose and insulin responses were measured over 4 h. Peak glucose and insulin responses occurred 60 min postprandially for the whole lentils and 30 min postprandially for ground lentils. Although the increase in plasma glucose after ground lentils (1.6 mM) was significantly higher (p less than 0.025) than that after whole lentils (0.9 mM), there was no difference in the magnitude of the insulin responses. These results indicate that, unlike for cereals, the rate of intestinal starch hydrolysis is not the major factor determining the metabolic responses to legumes. By virtue of their low postprandial glucose and insulin responses, irrespective of their physical form and digestibility, legumes would appear to be ideal for inclusion in the diet of diabetics.

  10. Effects of ocean acidification on the metabolic rates of three species of bivalve from southern coast of China

    Institute of Scientific and Technical Information of China (English)

    LIU Wenguang; HE Maoxian

    2012-01-01

    Oceanic uptake of anthropogenic carbon dioxide results in a decrease in seawater pH,a process known as “ocean acidification”.The pearl oyster Pinctada fucata,the noble scallop Chlamys nobilis,and the green-lipped mussel Perna viridis are species of economic and ecological importance along the southern coast of China.We evaluated the effects of seawater acidification on clearance,respiration,and excretion rates in these three species.The animals were reared in seawater at pH 8.1 (control),7.7,or 7.4.The clearance rate was highest at pH 7.7 for P.fucata and at pH 8.1 for C.nobilis and P.viridis.The pH had little effect on the respiration rate of P.fucata and P.viridis.In contrast,the respiration rate was significantly lower at pH 7.4 in C.nobilis.The excretion rate was significantly lower at pH 7.4 than pH 8.1 for all species.The results indicate that the reduction in seawater pH likely affected the metabolic process (food intake,oxygen consumption,and ammonia excretion) of these bivalves.Different species respond differently to seawater acidification.Further studies are needed to demonstrate the exact mechanisms for this effect and evaluate adaptability of these bivalves to future acidified oceans.

  11. The fungicide Pristine® inhibits mitochondrial function in vitro but not flight metabolic rates in honey bees.

    Science.gov (United States)

    Campbell, Jacob B; Nath, Rachna; Gadau, Juergen; Fox, Trevor; DeGrandi-Hoffman, Gloria; Harrison, Jon F

    2016-03-01

    Honey bees and other pollinators are exposed to fungicides that act by inhibiting fungal mitochondria. Here we test whether a common fungicide (Pristine®) inhibits the function of mitochondria of honeybees, and whether consumption of ecologically-realistic concentrations can cause negative effects on the mitochondria of flight muscles, or the capability for flight, as judged by CO2 emission rates and thorax temperatures during flight. Direct exposure of mitochondria to Pristine® levels above 5 ppm strongly inhibited mitochondrial oxidation rates in vitro. However, bees that consumed pollen containing Pristine® at ecologically-realistic concentrations (≈ 1 ppm) had normal flight CO2 emission rates and thorax temperatures. Mitochondria isolated from the flight muscles of the Pristine®-consuming bees had higher state 3 oxygen consumption rates than control bees, suggesting that possibly Pristine®-consumption caused compensatory changes in mitochondria. It is likely that the lack of a strong functional effect of Pristine®-consumption on flight performance and the in vitro function of flight muscle mitochondria results from maintenance of Pristine® levels in the flight muscles at much lower levels than occur in the food, probably due to metabolism and detoxification. As Pristine® has been shown to negatively affect feeding rates and protein digestion of honey bees, it is plausible that Pristine® consumption negatively affects gut wall function (where mitochondria may be exposed to higher concentrations of Pristine®).

  12. Investigations into the relationship of post-stress metabolic rates and growth of fishes

    Science.gov (United States)

    The objective of this study was to determine if respirometry indices of fish following a stressor correspond with growth. On four occasions over a period of one month, oxygen consumption rates of 16 hybrid striped bass families were measured following a standardized handling stressor. Groups of 10...

  13. Metabolic Rate and Ground Reaction Force During Motorized and Non-Motorized Treadmill Exercise

    Science.gov (United States)

    Everett, Meghan E.; Loehr, James A.; DeWitt, John K.; Laughlin, Mitzi; Lee, Stuart M. C.

    2010-01-01

    PURPOSE: To measure vertical ground reaction force (vGRF) and oxygen consumption (VO2) at several velocities during exercise using a ground-based version of the ISS treadmill in the M and NM modes. METHODS: Subjects (n = 20) walked or ran at 0.89, 1.34, 1.79, 2.24, 2.68, and 3.12 m/s while VO2 and vGRF data were collected. VO2 was measured using open-circuit spirometry (TrueOne 2400, Parvo-Medics). Data were averaged over the last 2 min of each 5-min stage. vGRF was measured in separate 15-s bouts at 125 Hz using custom-fitted pressure-sensing insoles (F-Scan Sport Sensors, Tekscan, Inc). A repeated-measures ANOVA was used to test for differences in VO2 and vGRF between M and NM and across speeds. Significance was set at P < 0.05. RESULTS: Most subjects were unable to exercise for 5 min at treadmill speeds above 1.79 m/s in the NM mode; however, vGRF data were obtained for all subjects at each speed in both modes. VO2 was approx.40% higher during NM than M exercise across treadmill speeds. vGRF increased with treadmill speed but was not different between modes. CONCLUSION: Higher VO2 with no change in vGRF suggests that the additional metabolic cost associated with NM treadmill exercise is accounted for in the horizontal forces required to move the treadmill belt. Although this may limit the exercise duration at faster speeds, high-intensity NM exercise activates the hamstrings and plantarflexors, which are not specifically targeted or well protected by other in-flight countermeasures.

  14. Global rates of marine sulfate reduction and implications for sub-sea-floor metabolic activities

    Science.gov (United States)

    Bowles, Marshall W.; Mogollón, José M.; Kasten, Sabine; Zabel, Matthias; Hinrichs, Kai-Uwe

    2014-05-01

    Sulfate reduction is a globally important redox process in marine sediments, yet global rates are poorly quantified. We developed an artificial neural network trained with 199 sulfate profiles, constrained with geomorphological and geochemical maps to estimate global sulfate-reduction rate distributions. Globally, 11.3 teramoles of sulfate are reduced yearly (~15% of previous estimates), accounting for the oxidation of 12 to 29% of the organic carbon flux to the sea floor. Combined with global cell distributions in marine sediments, these results indicate a strong contrast in sub-sea-floor prokaryote habitats: In continental margins, global cell numbers in sulfate-depleted sediment exceed those in the overlying sulfate-bearing sediment by one order of magnitude, whereas in the abyss, most life occurs in oxic and/or sulfate-reducing sediments.

  15. Metabolic rates and biochemical compositions of Apostichopus japonicus (Selenka) tissue during periods of inactivity

    Institute of Scientific and Technical Information of China (English)

    包杰; 董双林; 田相利; 王芳; 高勤峰; 董云伟

    2010-01-01

    Estivation, hibernation, and starvation are indispensable inactive states of sea cucumbers Apostichopus japonicus in nature and in culture ponds. Generally, temperature is the principal factor that induces estivation or hibernation in the sea cucumber. The present study provided insight into the physiological adaptations of A. japonicus during the three types of inactivity (hibernation, estivation, and starvation) by measuring the oxygen consumption rates (Vo2) and biochemical compositions under laboratory ...

  16. The Influence of Verapamil and Nicardipine on the Rate of Metabolism of Midazolam

    Science.gov (United States)

    2000-10-01

    coronary rate and force ( Katzung , 1998). Calcium channel blocking drugs are widely used and have documented effectiveness in angina, hypertension, and...supraventricular tachycardias. They are also of use in hypertrophic cardiomyopathy, migraine, atherosclerosis, and Raynaud’s syndrome ( Katzung , 1998). The...Bethesda, Maryland. Katzung , B. G. (1998). Vasodilators and the treatment of angina pectoris. In B. G. Katzung , (Ed.), Basic and clincial pharmacology

  17. Energy metabolism during human pregnancy.

    Science.gov (United States)

    Forsum, Elisabet; Löf, Marie

    2007-01-01

    This review summarizes information regarding how human energy metabolism is affected by pregnancy, and current estimates of energy requirements during pregnancy are presented. Such estimates can be calculated using either increases in basal metabolic rate (BMR) or increases in total energy expenditure (TEE). The two modes of calculation give similar results for a complete pregnancy but different distributions of energy requirements in the three trimesters. Recent information is presented regarding the effect of pregnancy on BMR, TEE, diet-induced thermogenesis, and physical activity. The validity of energy intake (EI) data recently assessed in well-nourished pregnant women was evaluated using information regarding energy metabolism during pregnancy. The results show that underreporting of EI is common during pregnancy and indicate that additional longitudinal studies, taking the total energy budget during pregnancy into account, are needed to satisfactorily define energy requirements during the three trimesters of gestation.

  18. Rate of starch hydrolysis in vitro as a predictor of metabolic responses to complex carbohydrate in vivo.

    Science.gov (United States)

    O'Dea, K; Snow, P; Nestel, P

    1981-10-01

    This study was designed to determine whether the rate of hydrolysis of different starches by pancreatic amylase in vitro was proportional to the postprandial glucose and insulin response to those starches after oral ingestion. Lean young men consumed four test meals of rice containing 75 g starch: white rice, unpolished (brown) rice, ground white rice, and ground brown rice. Postprandial glucose and insulin responses were measured over 4 h and showed the following pattern: ground white rice congruent to ground brown rice greater than white rice greater than brown rice. The maximum increases in blood glucose after the four meals were brown rice 0.9 mM, white rice 1.5 mM, ground brown rice 3.3 mM, and ground white rice 3.6 mM. Samples of the cooked rices were incubated in vitro with pancreatic amylase for 30 min and the percentage starch hydrolysis determine. The relative rates of starch hydrolysis correlated very closely with the peak glucose responses: brown rice 17.6%, white rice 30.8%, ground brown rice 68.2% and ground white rice 71.8%. These results indicated that the rate of intestinal hydrolysis of starch is an extremely important determinant of the metabolic responses to a particular starch. The rate of starch hydrolysis can be determine simply by an in vitro method and should assist the design of diets for the treatment of diabetes.

  19. Choosing the Right Basal Reader.

    Science.gov (United States)

    Robbins, Ruth H.

    1980-01-01

    Looks at factors in the textbook publishing industry, especially costs and censorship, which affect the quality of available reading series. Notes the problem of readability and content bias. Finally, presents a checklist of basal reader evaluation criteria. (SJL)

  20. Heart transcriptome of the bank vole (Myodes glareolus: towards understanding the evolutionary variation in metabolic rate

    Directory of Open Access Journals (Sweden)

    Kuduk Katarzyna

    2010-06-01

    Full Text Available Abstract Background Understanding the genetic basis of adaptive changes has been a major goal of evolutionary biology. In complex organisms without sequenced genomes, de novo transcriptome assembly using a longer read sequencing technology followed by expression profiling using short reads is likely to provide comprehensive identification of adaptive variation at the expression level and sequence polymorphisms in coding regions. We performed sequencing and de novo assembly of the bank vole heart transcriptome in lines selected for high metabolism and unselected controls. Results A single 454 Titanium run produced over million reads, which were assembled into 63,581 contigs. Searches against the SwissProt protein database and the ENSEMBL collection of mouse transcripts detected similarity to 11,181 and 14,051 genes, respectively. As judged by the representation of genes from the heart-related Gene Ontology categories and UniGenes detected in the mouse heart, our detection of the genes expressed in the heart was nearly complete (> 95% and almost 90% respectively. On average, 38.7% of the transcript length was covered by our sequences, with notably higher (45.0% coverage of coding regions than of untranslated regions (24.5% of 5' and 32.7% of 3'UTRs. Lower sequence conservation between mouse and bank vole in untranslated regions was found to be partially responsible for poorer UTR representation. Our data might suggest a widespread transcription from noncoding genomic regions, a finding not reported in previous studies regarding transcriptomes in non-model organisms. We also identified over 19 thousand putative single nucleotide polymorphisms (SNPs. A much higher fraction of the SNPs than expected by chance exhibited variant frequency differences between selection regimes. Conclusion Longer reads and higher sequence yield per run provided by the 454 Titanium technology in comparison to earlier generations of pyrosequencing proved beneficial for the

  1. Measuring and modeling C flux rates through the central metabolic pathways in microbial communities using position-specific 13C-labeled tracers

    Science.gov (United States)

    Dijkstra, P.; van Groenigen, K.; Hagerty, S.; Salpas, E.; Fairbanks, D. E.; Hungate, B. A.; KOCH, G. W.; Schwartz, E.

    2012-12-01

    The production of energy and metabolic precursors occurs in well-known processes such as glycolysis and Krebs cycle. We use position-specific 13C-labeled metabolic tracers, combined with models of microbial metabolic organization, to analyze the response of microbial community energy production, biosynthesis, and C use efficiency (CUE) in soils, decomposing litter, and aquatic communities. The method consists of adding position-specific 13C -labeled metabolic tracers to parallel soil incubations, in this case 1-13C and 2,3-13C pyruvate and 1-13C and U-13C glucose. The measurement of CO2 released from the labeled tracers is used to calculate the C flux rates through the various metabolic pathways. A simplified metabolic model consisting of 23 reactions is solved using results of the metabolic tracer experiments and assumptions of microbial precursor demand. This new method enables direct estimation of fundamental aspects of microbial energy production, CUE, and soil organic matter formation in relatively undisturbed microbial communities. We will present results showing the range of metabolic patterns observed in these communities and discuss results from testing metabolic models.

  2. Relationships between metabolic rate, muscle electromyograms and swim performance of adult chinook salmon

    Science.gov (United States)

    Geist, D.R.; Brown, R.S.; Cullinan, V.I.; Mesa, M.G.; VanderKooi, S.P.; McKinstry, C.A.

    2003-01-01

    Oxygen consumption rates of adult spring chinook salmon Oncorhynchus tshawytscha increased with swim speed and, depending on temperature and fish mass, ranged from 609 mg O2 h-1 at 30 cm s-1 (c. 0.5 BLs-1) to 3347 mg O2 h-1 at 170 cm s -1 (c. 2.3 BLs-1). Corrected for fish mass, these values ranged from 122 to 670 mg O2 kg-1 h-1, and were similar to other Oncorhynchus species. At all temperatures (8, 12.5 and 17??C), maximum oxygen consumption values levelled off and slightly declined with increasing swim speed >170 cm s-1, and a third-order polynomial regression model fitted the data best. The upper critical swim speed (Ucrit) of fish tested at two laboratories averaged 155 cm s -1 (2.1 BLs-1), but Ucrit of fish tested at the Pacific Northwest National Laboratory were significantly higher (mean 165 cm s-1) than those from fish tested at the Columbia River Research Laboratory (mean 140 cm s-1). Swim trials using fish that had electromyogram (EMG) transmitters implanted in them suggested that at a swim speed of c. 135 cm s-1, red muscle EMG pulse rates slowed and white muscle EMG pulse rates increased. Although there was significant variation between individual fish, this swim speed was c. 80% of the Ucrit for the fish used in the EMG trials (mean Ucrit 168.2 cm s-1). Bioenergetic modelling of the upstream migration of adult chinook salmon should consider incorporating an anaerobic fraction of the energy budget when swim speeds are ???80% of the Ucrit. ?? 2003 The Fisheries Society of the British Isles.

  3. Resting heart rate as a predictor of metabolic dysfunctions in obese children and adolescents

    Directory of Open Access Journals (Sweden)

    Freitas Júnior Ismael F

    2012-01-01

    Full Text Available Abstract Background Recent studies have identified that a higher resting heart rate (RHR is associated with elevated blood pressure, independent of body fatness, age and ethnicity. However, it is still unclear whether RHR can also be applied as a screening for other risk factors, such as hyperglycemia and dyslipidemia. Thus, the purpose of the presented study was to analyze the association between RHR, lipid profile and fasting glucose in obese children and adolescents. Methods The sample was composed of 180 obese children and adolescents, aged between 7-16 years. Whole-body and segmental body composition were estimated by Dual-energy X-ray absorptiometry. Resting heart rate (RHR was measured by heart rate monitors. The fasting blood samples were analyzed for serum triglycerides, total cholesterol (TC, high-density lipoprotein cholesterol (HDL-C, low-density lipoprotein cholesterol (LDL-C, and glucose, using the colorimetric method. Results Fasting glucose, TC, triglycerides, HDL-C, LDL-C and RHR were similar in both genders. The group of obese subjects with a higher RHR presented, at a lower age, higher triglycerides and TC. There was a significant relationship between RHR, triglycerides and TC. In the multivariate model, triglycerides and TC maintained a significant relationship with RHR independent of age, gender, general and trunk adiposity. The ROC curve indicated that RHR has a high potential for screening elevated total cholesterol and triglycerides as well as dyslipidemia. Conclusion Elevated RHR has the potential to identify subjects at an increased risk of atherosclerosis development.

  4. Mescaline: its effects on learning rate and dopamine metabolism in goldfish (Carassius auratus).

    Science.gov (United States)

    Zeller, E A; Couper, G S; Huprikar, S V; Mellow, A M; Moody, R R

    1976-11-15

    The pharmacological action of mescaline on goldfish was studied with the Bitterman-Agranoff shock-avoidance test. In short term experiments with high mescaline doses an increase in learning rates was observed. Similar results were obtained with apomorphine and L-dopa. However, when the fish were exposed to smaller mescaline doses (or to fluphenazine) for 3 days, their ability to avoid electric shock was reduced. Apparently, mescaline induced a release of dopamine which stimulated central dopaminergic systems. Subsequently, MAO destroys the liberated dopamine. Thus, the ensuing dopamine deficit appears to be responsible for the marked changes in behavior in the chronic experiment.

  5. Metabolic behavior of Lactococcus lactis MG1363 in microaerobic continuous cultivation at a low dilution rate

    DEFF Research Database (Denmark)

    Jensen, Niels B.S.; Melchiorsen, Claus Rix; Jochumsen, Kirsten Væver;

    2001-01-01

    Minute amounts of oxygen were supplied to a continuous cultivation of Lactococcus lactis subsp. cremoris MG1363 grown on a defined glucose-limited medium at a dilution rate of 0.1 h(-1). More than 80% of the carbon supplied with glucose ended up in fermentation products other than lactate. Addition...... dioxide and acetate to replace formate and ethanol as catabolic end products while hardly affecting the production of either acetoin or lactate. The negative impact of oxygen on the synthesis of pyruvate formate lyase was confirmed. Moreover, oxygen was shown to down regulate the protein level of alcohol...

  6. Influence of GSM900 electromagnetic fields on the metabolic rate in rodents

    Directory of Open Access Journals (Sweden)

    A. El Ouardi

    2008-05-01

    Full Text Available The development of exposure devices for investigating possible effects of mobile communication systems to non-restrained animals aims at a homogenous field distribution in the area the animals occupy. In the presented 900 MHz exposure device a quite good field homogeneity of 5% (including the standing wave contribution due to internal reflections is reached in the cage region mainly by flattening the transverse field. For the standard waveguide (WR1150 without dielectric sheets this value reads 14%. The desired maximal whole body specific absorption rate (SAR of 4 W/kg in the Djungarian hamster model is achieved at an input power of only 3.7 W.

  7. Comparative analysis of false discovery rate methods in constructing metabolic association networks.

    Science.gov (United States)

    Koo, Imhoi; Yao, Sen; Zhang, Xiang; Kim, Seongho

    2014-08-01

    Gaussian graphical model (GGM)-based method, a key approach to reverse engineering biological networks, uses partial correlation to measure conditional dependence between two variables by controlling the contribution from other variables. After estimating partial correlation coefficients, one of the most critical processes in network construction is to control the false discovery rate (FDR) to assess the significant associations among variables. Various FDR methods have been proposed mainly for biomarker discovery, but it still remains unclear which FDR method performs better for network construction. Furthermore, there is no study to see the effect of the network structure on network construction. We selected the six FDR methods, the linear step-up procedure (BH95), the adaptive linear step-up procedure (BH00), Efron's local FDR (LFDR), Benjamini-Yekutieli's step-up procedure (BY01), Storey's q-value procedure (Storey01), and Storey-Taylor-Siegmund's adaptive step-up procedure (STS04), to evaluate their performances on network construction. We further considered two network structures, random and scale-free networks, to investigate their influence on network construction. Both simulated data and real experimental data suggest that STS04 provides the highest true positive rate (TPR) or F1 score, while BY01 has the highest positive predictive value (PPV) in network construction. In addition, no significant effect of the network structure is found on FDR methods.

  8. Quantifying the cerebral metabolic rate of oxygen by combining diffuse correlation spectroscopy and time-resolved near-infrared spectroscopy.

    Science.gov (United States)

    Verdecchia, Kyle; Diop, Mamadou; Lee, Ting-Yim; St Lawrence, Keith

    2013-02-01

    Preterm infants are highly susceptible to ischemic brain injury; consequently, continuous bedside monitoring to detect ischemia before irreversible damage occurs would improve patient outcome. In addition to monitoring cerebral blood flow (CBF), assessing the cerebral metabolic rate of oxygen (CMRO2) would be beneficial considering that metabolic thresholds can be used to evaluate tissue viability. The purpose of this study was to demonstrate that changes in absolute CMRO2 could be measured by combining diffuse correlation spectroscopy (DCS) with time-resolved near-infrared spectroscopy (TR-NIRS). Absolute CBF was determined using bolus-tracking TR-NIRS to calibrate the DCS measurements. Cerebral venous blood oxygenation (SvO2) was determined by multiwavelength TR-NIRS measurements, the accuracy of which was assessed by directly measuring the oxygenation of sagittal sinus blood. In eight newborn piglets, CMRO2 was manipulated by varying the anesthetics and by injecting sodium cyanide. No significant differences were found between the two sets of SvO2 measurements obtained by TR-NIRS or sagittal sinus blood samples and the corresponding CMRO2 measurements. Bland-Altman analysis showed a mean CMRO2 difference of 0.0268 ± 0.8340 mLO2/100 g/min between the two techniques over a range from 0.3 to 4 mL O2/100 g/min.

  9. Thermopreference, tolerance and metabolic rate of early stages juvenile Octopus maya acclimated to different temperatures.

    Science.gov (United States)

    Noyola, Javier; Caamal-Monsreal, Claudia; Díaz, Fernando; Re, Denisse; Sánchez, Adolfo; Rosas, Carlos

    2013-01-01

    Thermopreference, tolerance and oxygen consumption rates of early juveniles Octopus maya (O. maya; weight range 0.38-0.78g) were determined after acclimating the octopuses to temperatures (18, 22, 26, and 30°C) for 20 days. The results indicated a direct relationship between preferred temperature (PT) and acclimated temperature, the PT was 23.4°C. Critical Thermal Maxima, (CTMax; 31.8±1.2, 32.7±0.9, 34.8±1.4 and 36.5±1.0) and Critical Thermal Minima, (CTMin; 11.6±0.2, 12.8±0.6, 13.7±1.0, 19.00±0.9) increased significantly (P<0.05) with increasing acclimation temperatures. The endpoint for CTMax was ink release and for CTMin was tentacles curled, respectively. A thermal tolerance polygon over the range of 18-30°C resulted in a calculated area of 210.0°C(2). The oxygen consumption rate increased significantly α=0.05 with increasing acclimation temperatures between 18 and 30°C. Maximum and minimum temperature quotients (Q10) were observed between 26-30°C and 22-26°C as 3.03 and 1.71, respectively. These results suggest that O. maya has an increased capability for adapting to moderate temperatures, and suggest increased culture potential in subtropical regions southeast of México.

  10. Essential fatty acids influence metabolic rate and tolerance of hypoxia in Dover sole ( Solea solea ) larvae and juveniles

    DEFF Research Database (Denmark)

    McKenzie, David; Lund, Ivar; Pedersen, Per Bovbjerg

    2008-01-01

    Dover sole (Solea solea, Linneaus 1758) were raised from first feeding on brine shrimp (Artemia sp.) with different contents and compositions of the essential fatty acids (EFA) arachidonic acid (ARA, 20:4n - 6); eicosapentaenoic acid (EPA, 20:5n - 3), and docosahexaenoic acid (DHA, 22:6n - 3......), and their metabolic rate and tolerance to hypoxia measured prior to and following metamorphosis and settlement. Four dietary Artemia preparations were compared: (1) un-enriched; (2) enriched with a commercial EFA mixture (Easy DHA SELCO Emulsion); (3) enriched with a marine fish oil combination (VEVODAR and Incromega......-crit, but juveniles fed on un-enriched Artemia still exhibited higher P-crit and agitation thresholds than the other groups. Sole fed un-enriched Artemia had significantly lower contents of EFA in their tissues, both before and after settlement. Thus, enriching live feeds with EFA has significant effects...

  11. Sea urchins in a high-CO2 world: partitioned effects of body size, ocean warming and acidification on metabolic rate.

    Science.gov (United States)

    Carey, Nicholas; Harianto, Januar; Byrne, Maria

    2016-04-15

    Body size and temperature are the major factors explaining metabolic rate, and the additional factor of pH is a major driver at the biochemical level. These three factors have frequently been found to interact, complicating the formulation of broad models predicting metabolic rates and hence ecological functioning. In this first study of the effects of warming and ocean acidification, and their potential interaction, on metabolic rate across a broad range in body size (two to three orders of magnitude difference in body mass), we addressed the impact of climate change on the sea urchin ITALIC! Heliocidaris erythrogrammain context with climate projections for southeast Australia, an ocean warming hotspot. Urchins were gradually introduced to two temperatures (18 and 23°C) and two pH levels (7.5 and 8.0), at which they were maintained for 2 months. Identical experimental trials separated by several weeks validated the fact that a new physiological steady state had been reached, otherwise known as acclimation. The relationship between body size, temperature and acidification on the metabolic rate of ITALIC! H. erythrogrammawas strikingly stable. Both stressors caused increases in metabolic rate: 20% for temperature and 19% for pH. Combined effects were additive: a 44% increase in metabolism. Body size had a highly stable relationship with metabolic rate regardless of temperature or pH. None of these diverse drivers of metabolism interacted or modulated the effects of the others, highlighting the partitioned nature of how each influences metabolic rate, and the importance of achieving a full acclimation state. Despite these increases in energetic demand there was very limited capacity for compensatory modulating of feeding rate; food consumption increased only in the very smallest specimens, and only in response to temperature, and not pH. Our data show that warming, acidification and body size all substantially affect metabolism and are highly consistent and

  12. Metabolic rate, evaporative water loss and thermoregulatory state in four species of bats in the Negev desert.

    Science.gov (United States)

    Muñoz-Garcia, Agustí; Larraín, Paloma; Ben-Hamo, Miriam; Cruz-Neto, Ariovaldo; Williams, Joseph B; Pinshow, Berry; Korine, Carmi

    2016-01-01

    Life in deserts is challenging for bats because of their relatively high energy and water requirements; nevertheless bats thrive in desert environments. We postulated that bats from desert environments have lower metabolic rates (MR) and total evaporative water loss (TEWL) than their mesic counterparts. To test this idea, we measured MR and TEWL of four species of bats, which inhabit the Negev desert in Israel, one species mainly restricted to hyper-arid deserts (Otonycteris hemprichii), two species from semi-desert areas (Eptesicus bottae and Plecotus christii), and one widespread species (Pipistrellus kuhlii). We also measured separately, in the same individuals, the two components of TEWL, respiratory water loss (RWL) and cutaneous evaporative water loss (CEWL), using a mask. In all the species, MR and TEWL were significantly reduced during torpor, the latter being a consequence of reductions in both RWL and CEWL. Then, we evaluated whether MR and TEWL in bats differ according to their geographic distributions, and whether those rates change with Ta and the use of torpor. We did not find significant differences in MR among species, but we found that TEWL was lowest in the species restricted to desert habitats, intermediate in the semi-desert dwelling species, and highest in the widespread species, perhaps a consequence of adaptation to life in deserts. Our results were supported by a subsequent analysis of data collected from the literature on rates of TEWL for 35 bat species from desert and mesic habitats.

  13. Metabolic rates of ATP transfer through creatine kinase (CK Flux) predict clinical heart failure events and death.

    Science.gov (United States)

    Bottomley, Paul A; Panjrath, Gurusher S; Lai, Shenghan; Hirsch, Glenn A; Wu, Katherine; Najjar, Samer S; Steinberg, Angela; Gerstenblith, Gary; Weiss, Robert G

    2013-12-11

    Morbidity and mortality from heart failure (HF) are high, and current risk stratification approaches for predicting HF progression are imperfect. Adenosine triphosphate (ATP) is required for normal cardiac contraction, and abnormalities in creatine kinase (CK) energy metabolism, the primary myocardial energy reserve reaction, have been observed in experimental and clinical HF. However, the prognostic value of abnormalities in ATP production rates through CK in human HF has not been investigated. Fifty-eight HF patients with nonischemic cardiomyopathy underwent ³¹P magnetic resonance spectroscopy (MRS) to quantify cardiac high-energy phosphates and the rate of ATP synthesis through CK (CK flux) and were prospectively followed for a median of 4.7 years. Multiple-event analysis (MEA) was performed for HF-related events including all-cause and cardiac death, HF hospitalization, cardiac transplantation, and ventricular-assist device placement. Among baseline demographic, clinical, and metabolic parameters, MEA identified four independent predictors of HF events: New York Heart Association (NYHA) class, left ventricular ejection fraction (LVEF), African-American race, and CK flux. Reduced myocardial CK flux was a significant predictor of HF outcomes, even after correction for NYHA class, LVEF, and race. For each increase in CK flux of 1 μmol g⁻¹ s⁻¹, risk of HF-related composite outcomes decreased by 32 to 39%. These findings suggest that reduced CK flux may be a potential HF treatment target. Newer imaging strategies, including noninvasive ³¹P MRS that detect altered ATP kinetics, could thus complement risk stratification in HF and add value in conditions involving other tissues with high energy demands, including skeletal muscle and brain.

  14. “IDEAL” Aging is Associated with Lower Resting Metabolic Rate: The Baltimore Longitudinal Study of Aging

    Science.gov (United States)

    Schrack, Jennifer A.; Knuth, Nicolas D.; Simonsick, Eleanor M.; Ferrucci, Luigi

    2014-01-01

    Objectives To assess the associations among age, health status, and resting metabolic rate (RMR) in a large population of older adults. Design Cross-Sectional Analysis Setting Community-dwelling volunteers from the Baltimore Longitudinal Study of Aging (BLSA) Participants Four hundred twenty persons aged 40 – 96 (mean 68.2 ± 11.0) who underwent a comprehensive physical examination, cognitive assessment, resting metabolic rate testing, body composition assessment, and physical function testing during a three-day clinic visit. Measurements Participants were assigned to “IDEAL” (Insight into the Determination of Exceptional Aging and Longevity) or “non-IDEAL” categories based on health status. IDEAL participants were defined by the absence of: physical and cognitive impairments, chronic conditions/comorbidities and blood profile alterations. A three-stage linear regression model was used to assess the relationship between RMR and age, using IDEAL classification as a predictor, adjusting for sex and body composition. Results RMR averaged 1512.4 (± 442.9) kcal/day and was lower with advancing age (β = −8.55, p < 0.001). After adjusting for age, sex, and body composition RMR was 109.6 kcals/day lower in IDEAL than non-IDEAL participants (p < 0.005). Conclusions Individuals who are fully functional and free of major medical conditions have lower RMR than those affected by disease and functional impairments. These findings suggest that health status plays a role in energy utilization and regulation independent of age and body composition and that elevated RMR may be a global biomarker of poor health in older persons. PMID:24635835

  15. Nonsurgical Treatment Options for Basal Cell Carcinoma

    Directory of Open Access Journals (Sweden)

    Mary H. Lien

    2011-01-01

    Full Text Available Basal cell carcinoma (BCC remains the most common form of nonmelanoma skin cancer (NMSC in Caucasians, with perhaps as many as 2 million new cases expected to occur in the United States in 2010. Many treatment options, including surgical interventions and nonsurgical alternatives, have been utilized to treat BCC. In this paper, two non-surgical options, imiquimod therapy and photodynamic therapy (PDT, will be discussed. Both modalities have demonstrated acceptable disease control rates, cosmetically superior outcomes, and short-term cost-effectiveness. Further studies evaluating long-term cure rates and long-term cost effectiveness of imiquimod therapy and PDT are needed.

  16. Effects of intraspecific variation in reproductive traits, pectoral fin use and burst swimming on metabolic rates and swimming performance in the Trinidadian guppy (Poecilia reticulata).

    Science.gov (United States)

    Svendsen, Jon C; Banet, Amanda I; Christensen, Rune H B; Steffensen, John F; Aarestrup, Kim

    2013-09-15

    There is considerable intraspecific variation in metabolic rates and locomotor performance in aquatic ectothermic vertebrates; however, the mechanistic basis remains poorly understood. Using pregnant Trinidadian guppies (Poecilia reticulata), a live-bearing teleost, we examined the effects of reproductive traits, pectoral fin use and burst-assisted swimming on swimming metabolic rate, standard metabolic rate (O2std) and prolonged swimming performance (Ucrit). Reproductive traits included reproductive allocation and pregnancy stage, the former defined as the mass of the reproductive tissues divided by the total body mass. Results showed that the metabolic rate increased curvilinearly with swimming speed. The slope of the relationship was used as an index of swimming cost. There was no evidence that reproductive traits correlated with swimming cost, O2std or Ucrit. In contrast, data revealed strong effects of pectoral fin use on swimming cost and Ucrit. Poecilia reticulata employed body-caudal fin (BCF) swimming at all tested swimming speeds; however, fish with a high simultaneous use of the pectoral fins exhibited increased swimming cost and decreased Ucrit. These data indicated that combining BCF swimming and pectoral fin movement over a wide speed range, presumably to support swimming stability and control, is an inefficient swimming behaviour. Finally, transition to burst-assisted swimming was associated with an increase in aerobic metabolic rate. Our study highlights factors other than swimming speed that affect swimming cost and suggests that intraspecific diversity in biomechanical performance, such as pectoral fin use, is an important source of variation in both locomotor cost and maximal performance.

  17. An improved thermoregulatory model for cooling garment applications with transient metabolic rates

    Science.gov (United States)

    Westin, Johan K.

    Current state-of-the-art thermoregulatory models do not predict body temperatures with the accuracies that are required for the development of automatic cooling control in liquid cooling garment (LCG) systems. Automatic cooling control would be beneficial in a variety of space, aviation, military, and industrial environments for optimizing cooling efficiency, for making LCGs as portable and practical as possible, for alleviating the individual from manual cooling control, and for improving thermal comfort and cognitive performance. In this study, we adopt the Fiala thermoregulatory model, which has previously demonstrated state-of-the-art predictive abilities in air environments, for use in LCG environments. We validate the numerical formulation with analytical solutions to the bioheat equation, and find our model to be accurate and stable with a variety of different grid configurations. We then compare the thermoregulatory model's tissue temperature predictions with experimental data where individuals, equipped with an LCG, exercise according to a 700 W rectangular type activity schedule. The root mean square (RMS) deviation between the model response and the mean experimental group response is 0.16°C for the rectal temperature and 0.70°C for the mean skin temperature, which is within state-of-the-art variations. However, with a mean absolute body heat storage error 3¯ BHS of 9.7 W˙h, the model fails to satisfy the +/-6.5 W˙h accuracy that is required for the automatic LCG cooling control development. In order to improve model predictions, we modify the blood flow dynamics of the thermoregulatory model. Instead of using step responses to changing requirements, we introduce exponential responses to the muscle blood flow and the vasoconstriction command. We find that such modifications have an insignificant effect on temperature predictions. However, a new vasoconstriction dependency, i.e. the rate of change of hypothalamus temperature weighted by the

  18. Greater left cerebral hemispheric metabolism in bulimia assessed by positron emission tomography

    Energy Technology Data Exchange (ETDEWEB)

    Wu, J.C.; Hagman, J.; Buchsbaum, M.S.; Blinder, B.; Derrfler, M.; Tai, W.Y.; Hazlett, E.; Sicotte, N. (Univ. of California, Irvine (USA))

    1990-03-01

    Eight women with bulimia and eight age- and sex-matched normal control subjects were studied with positron emission tomography using (18F)-fluorodeoxyglucose (FDG) as a tracer of brain metabolic rate. Subjects performed a visual vigilance task during FDG uptake. In control subjects, the metabolic rate was higher in the right hemisphere than in the left, but patients with bulimia did not have this normal asymmetry. Lower metabolic rates in the basal ganglia, found in studies of depressed subjects, and higher rates in the basal ganglia, reported in a study of anorexia nervosa, were not found. This is consistent with the suggestion that bulimia is a diagnostic grouping distinct from these disorders.

  19. Lipid metabolism and body composition in Gclm(-/-) mice

    Energy Technology Data Exchange (ETDEWEB)

    Kendig, Eric L. [Department of Environmental Health, University of Cincinnati Medical Center, P.O. Box 670056, Cincinnati, OH 45267 (United States); Center for Environmental Genetics, University of Cincinnati Medical Center, P.O. Box 670056, Cincinnati, OH 45267 (United States); Chen, Ying [Department of Pharmaceutical Sciences, School of Pharmacy, University of Colorado Denver, Aurora, CO 80045 (United States); Krishan, Mansi; Johansson, Elisabet; Schneider, Scott N. [Department of Environmental Health, University of Cincinnati Medical Center, P.O. Box 670056, Cincinnati, OH 45267 (United States); Genter, Mary Beth; Nebert, Daniel W. [Department of Environmental Health, University of Cincinnati Medical Center, P.O. Box 670056, Cincinnati, OH 45267 (United States); Center for Environmental Genetics, University of Cincinnati Medical Center, P.O. Box 670056, Cincinnati, OH 45267 (United States); Shertzer, Howard G., E-mail: shertzhg@ucmail.uc.edu [Department of Environmental Health, University of Cincinnati Medical Center, P.O. Box 670056, Cincinnati, OH 45267 (United States); Center for Environmental Genetics, University of Cincinnati Medical Center, P.O. Box 670056, Cincinnati, OH 45267 (United States)

    2011-12-15

    In humans and experimental animals, high fat diets (HFD) are associated with risk factors for metabolic diseases, such as excessive weight gain and adiposity, insulin resistance and fatty liver. Mice lacking the glutamate-cysteine ligase modifier subunit gene (Gclm(-/-)) and deficient in glutathione (GSH), are resistant to HFD-mediated weight gain. Herein, we evaluated Gclm-associated regulation of energy metabolism, oxidative stress, and glucose and lipid homeostasis. C57BL/6J Gclm(-/-) mice and littermate wild-type (WT) controls received a normal diet or an HFD for 11 weeks. HFD-fed Gclm(-/-) mice did not display a decreased respiratory quotient, suggesting that they are unable to process lipid for metabolism. Although dietary energy consumption and intestinal lipid absorption were unchanged in Gclm(-/-) mice, feeding these mice an HFD did not produce excess body weight nor fat storage. Gclm(-/-) mice displayed higher basal metabolic rates resulting from higher activities of liver mitochondrial NADH-CoQ oxidoreductase, thus elevating respiration. Although Gclm(-/-) mice exhibited strong systemic and hepatic oxidative stress responses, HFD did not promote glucose intolerance or insulin resistance. Furthermore, HFD-fed Gclm(-/-) mice did not develop fatty liver, likely resulting from very low expression levels of genes encoding lipid metabolizing enzymes. We conclude that Gclm is involved in the regulation of basal metabolic rate and the metabolism of dietary lipid. Although Gclm(-/-) mice display a strong oxidative stress response, they are protected from HFD-induced excessive weight gain and adipose deposition, insulin resistance and steatosis. -- Highlights: Black-Right-Pointing-Pointer A high fat diet does not produce body weight and fat gain in Gclm(-/-) mice. Black-Right-Pointing-Pointer A high fat diet does not induce steatosis or insulin resistance in Gclm(-/-) mice. Black-Right-Pointing-Pointer Gclm(-/-) mice have high basal metabolism and mitochondrial

  20. Effects of intraspecific variation in reproductive traits, pectoral fin use and burst swimming on metabolic rates and swimming performance in the Trinidadian guppy (Poecilia reticulata)

    DEFF Research Database (Denmark)

    Svendsen, Jon Christian; Banet, Amanda I.; Christensen, Rune Haubo Bojesen

    2013-01-01

    of reproductive traits, pectoral fin use and burse-assisted swimming on swimming metabolic rate, standard metabolic rate (MO2std) and prolonged swimming performance (Ucrit). Reproductive traits included reproductive allocation and pregnancy stage, the former defined as the mass of the reproductive tissues divided...... by the total body mass. Results showed that the metabolic rate increased curvilinearly with swimming speed. The slope of the relationship was used as an index of swimming cost. There was no evidence that reproductive traits correlated with swimming cost, MO2std or Ucrit. In contrast, data revealed strong...... effects of pectoral fin use on swimming cost and Ucrit. Poecilia reticulata employed body-caudal fin (BCF) swimming at all tested swimming speeds; however, fish with a high simultaneous use of the pectoral fins exhibited increased swimming cost and decreased Ucrit. These data indicated that combining BCF...

  1. Nevoid basal cell carcinoma syndrome

    Directory of Open Access Journals (Sweden)

    Kannan Karthiga

    2006-01-01

    Full Text Available Binkley and Johnson first reported this syndrome in 1951. But it was in 1960, Gorlin-Goltz established the association of basal cell epithelioma, jaw cyst and bifid ribs, a combination which is now frequently known as Gorlin-Goltz syndrome as well as Nevoid Basal Cell Carcinoma Syndrome (NBCCS. NBCCS is inherited as an autosomal dominant trait with high penetrance and variable expressivity. NBCCS is characterized by variety of cutaneous, dental, osseous, opthalmic, neurologic and sexual abnormalities. One such case of Gorlin-Goltz syndrome is reported here with good illustrations.

  2. Energy metabolism during the menstrual cycle, pregnancy and lactation in well nourished Indian women.

    NARCIS (Netherlands)

    Piers, L.S.

    1994-01-01

    The measured basal metabolic rates (BMR) of present day Indian women were found to be comparable to published BMRs, measured in Indian women over 50 years ago, but 7 percent lower than present European/American women. This can possibly be due to differences in body composition or climate. Schofield'

  3. Carbon Dioxide Impacts in the Deep-Sea: Is Maintaining a Metabolically Required CO2 Efflux Rate Challenging?

    Science.gov (United States)

    Peltzer, E. T.; Hofmann, A. F.; Brewer, P. G.

    2011-12-01

    Increasing ocean acidification from fossil fuel CO2 invasion, from temperature driven changes in respiration, and from possible leakage from sub-seabed geologic CO2 disposal has aroused concern over the impacts of elevated CO2 concentrations on marine life. Here we describe the rate problem for animals who must export CO2 at about the same rate at which O2 is consumed. We analyze the basic properties controlling CO2 export within the diffusive boundary of marine animals in a changing ocean in order to compare the challenges posed by O2 uptake under stress with the equivalent problem of CO2 expulsion. The problem is more complex than that for a non-reactive gas since, as with gas exchange of CO2 at the air-sea interface, the influence of the ensemble of reactions within the CO2 - HCO3- - CO3= acid-base system needs to be considered. These reactions appear as an enhancement factor which significantly facilitates CO2 efflux compared to O2 intake at equal temperature, pressure and flow rate under typical oceanic concentrations. Possibly as an adaptation to this chemical advantage marine animals typically can respond to external CO2 stress simply by metabolic adjustment. This is energetically more favorable than having to resort to mechanically increasing flow over their surface to thin the boundary layer as is required to alleviate O2 stress. Regionally as with O2 the combination of T, P, and pH/pCO2 creates a zone of maximum CO2 stress at around 1000 m depth. But the net result is that the combination of an increase in T combined with declining O2 poses a greater respiratory challenge to marine life than does increasing CO2. The relationships developed here allow a more accurate prediction of the impacts on marine life from the combined effects of changing T, O2, and CO2 than can be estimated from single variable studies.

  4. Antihypertensive medication versus health promotion for improving metabolic syndrome in preventing cardiovascular events: a success rate-oriented simulation study

    Directory of Open Access Journals (Sweden)

    Satoh Makiko

    2011-02-01

    Full Text Available Abstract Background In practice, it is difficult to compare the effectiveness of traditional antihypertensive treatment with that of health promotion in reducing incidence rate of cardiovascular disease (IRCVD, events/year. This simulation study compared the effectiveness of two approaches to reducing IRCVD in a sample population: a traditional approach, in which high-risk patients are treated with conventional antihypertensive medications, and a population-based approach, in which subjects participate in a health promotion program. Methods We constructed a simulation model for a sample population of middle-aged Japanese men whose systolic blood pressure (SBP levels are normally distributed (130 ± 20 mm Hg. The principal assumption was that IRCVD increases exponentially according to SBP. The population IRCVD was calculated as the product of the distribution of SBP multiplied by IRCVD at each SBP. The cumulative IRCVD was calculated by the definite integral from the lowest to the highest SBP of IRCVD at each SBP level. The success rates were calculated according to SBP and metabolic risk profiles in the two approaches, respectively. Results The reduction in IRCVD was twice as large for antihypertensive medications as it was for health promotion in several situations. For example, if adherence to antihypertensive treatment occurred at a realistic level, the decrease in IRCVD was estimated at 9.99 × 10-4. In contrast, even if the health program was promoted optimistically, the decrease in IRCVD was estimated at 4.69 × 10-4. Conclusions The success rate-oriented simulation suggests that prescribing antihypertensive medications is superior to promoting the health promotion program in reducing IRCVD in virtual middle-aged Japanese men.

  5. Establishment of steady-state metabolism of ethanol in perfused rat liver: the quantitative analysis using kinetic mechanism-based rate equations of alcohol dehydrogenase.

    Science.gov (United States)

    Yao, Chung-Tay; Lai, Ching-Long; Hsieh, Hsiu-Shan; Chi, Chin-Wen; Yin, Shih-Jiun

    2010-09-01

    Alcohol dehydrogenase (ADH) catalyzes oxidation of ingested ethanol to acetaldehyde, the first step in hepatic metabolism. The purpose of this study was to establish an ex vivo rat liver perfusion system under defined and verified steady states with respect to the metabolites and the metabolic rates, and to quantitatively correlate the observed rates with simulations based on the kinetic mechanism-based rate equations of rat liver ADH. Class I ADH1 was isolated from male Sprague-Dawley rats and characterized by steady-state kinetics in the Krebs-Ringer perfusion buffer with supplements. Nonrecirculating liver perfusion with constant input of ethanol at near physiological hepatic blood flow rate was performed in situ. Ethanol and the related metabolites acetaldehyde, acetate, lactate, and pyruvate in perfusates were determined. Results of the initial velocity, product, and dead-end inhibition studies showed that rat ADH1 conformed to the Theorell-Chance Ordered Bi Bi mechanism. Steady-state metabolism of ethanol in the perfused liver maintained up to 3h as evidenced by the steady-state levels of ethanol and metabolites in the effluent, and the steady-state ethanol disappearance rates and acetate production rates. The changes of the metabolic rates were qualitatively and in general quantitatively correlated to the results from simulations with the kinetic rate equations of ADH1 under a wide range of ethanol, in the presence of competitive inhibitor 4-methylpyrazole and of uncompetitive inhibitor isobutyramide. Preliminary flux control analysis estimated that apparent C(ADH)(J) in the perfused liver may approximate 0.7 at constant infusion with 1-2 mM ethanol, suggesting that ADH plays a major but not the exclusive role in governing hepatic ethanol metabolism. The reported steady-state rat liver perfusion system may potentially be applicable to other drug or drug-ethanol interaction studies.

  6. Encephalopathy with calcifications of the basal ganglia in children. A reappraisal of Fahr's syndrome with respect to 14 new cases.

    Science.gov (United States)

    Billard, C; Dulac, O; Bouloche, J; Echenne, B; Lebon, P; Motte, J; Robain, O; Santini, J J

    1989-02-01

    Calcifications of the basal ganglia are described under the heading of "Fahr's syndrome". The clinical pattern is variable and the syndrome may be sporadic or familial. This study describes a personal series of 14 cases of encephalopathy with calcification of the basal ganglia and reviews the literature cases. A four-group classification is proposed. The first group includes encephalopathy, microcephaly, dwarfism, retinal degeneration or optic atrophy, symmetrical patchy demyelination with calcifications and probable autosomal recessive inheritance. Some cases have an early onset, a rapid evolution. Others have a later onset, longer course and retinal degeneration. In the second group, the children suffer from a congenital encephalopathy or a cerebral palsy without clear deterioration, without short stature, ocular impairment or persistent CSF abnormalities. This group has not been reported in the literature. The cases do not seem to be genetic. The precise cause in unknown but a sporadic non progressive anoxo-ischemic, or viral prenatal disease is suggested. In the third group, the association of encephalopathy, microcephaly, and persistent CSF lymphocytosis, has a high recurrence rate. The pathogenesis is still a matter of dispute. The fourth group is characterized by autosomal dominant calcifications of the basal ganglia with or without neurological abnormalities. Finally calcium metabolism disorders and mitochondrial encephalomyopathy may be associated with calcifications of the basal ganglia.

  7. Increase of glucose consumption in basal ganglia, thalamus and frontal cortex of patients with spasmodic torticollis

    Energy Technology Data Exchange (ETDEWEB)

    Grassi, F.; Bressi, S.; Antoni, M. [Univ. of Milan (Italy)] [and others

    1994-05-01

    The pathophysiology of spasmodic torticollis, a focal dystonia involving neck muscles, is still unclear. Positron emission tomography (PET) studies showed either an increase as well as a decrease of regional cerebral metabolic rate of glucose (rCMRglu) in basal ganglia. In the present study, [18F]FDG and PET was used to measure rCMRglu in 10 patients with spasmodic torticollis (mean age 50.37 {plus_minus} 11.47) and 10 age matched controls. All cases with a short disease duration, were untreated. A factorial analysis of variance revealed a significant bilateral increase of glucose consumption in caudate nucleus and pallidum/putamen complex (p>0.004) and in the cerebellum (p>0.001). The rCMRglu increase in the motor/premotor cortex and in the thalamus reached a trend towards significance (p<0.05). These preliminary data show enhanced metabolism in basal ganglia and cerebellum as the functional correlate of focal dystonia. A recently proposed model suggests that dystonia would be the consequence of a putaminal hyperactivity, leading to the breakdown of the pallidal inhibitory control on thalamus and thalamo-cortical projections.

  8. Cryotherapy in basal cell carcinoma

    Directory of Open Access Journals (Sweden)

    Sandra A

    1999-01-01

    Full Text Available Cryotherapy has proved to be an effective tool in the management of various dermatoses. We report 6 patients with histopathologically proven basal cell carcinoma of variable sizes treated with liquid nitrogen cryotherapy by the open spray technique. Lesions tended to heal with depigmentation and scar formation. However depigmented areas often repigmented over a period of time.

  9. Paradoxical dissociation between heart rate and heart rate variability following different modalities of exercise in individuals with metabolic syndrome: The RESOLVE study.

    Science.gov (United States)

    Boudet, Gil; Walther, Guillaume; Courteix, Daniel; Obert, Philippe; Lesourd, Bruno; Pereira, Bruno; Chapier, Robert; Vinet, Agnès; Chamoux, Alain; Naughton, Geraldine; Poirier, Paul; Dutheil, Frédéric

    2017-02-01

    Aims To analyse the effects of different modalities of exercise training on heart rate variability (HRV) in individuals with metabolic syndrome (MetS). Methods and results Eighty MetS participants (aged 50-70 years) were housed and managed in an inpatient medical centre for 21 days, including weekends. Physical activity and food intake/diet were intensively monitored. Participants were randomly assigned into three training groups, differing only by intensity of exercise: moderate-endurance-moderate-resistance ( re), high-resistance-moderate-endurance ( Re), and moderate-resistance-high-endurance ( rE). HRV was recorded before and after the intervention by 24-hour Holter electrocardiogram. Although mean 24-hour heart rate decreased more in Re than re (-11.6 ± 1.6 vs. -4.8 ± 2.1%; P = 0.010), low frequency/high frequency decreased more in re than Re (-20.4 ± 5.5% vs. + 20.4 ± 9.1%; P = 0.002) and rE (-20.4 ± 5.5% vs. -0.3 ± 11.1%; P = 0.003). Very low frequency increased more in Re than re (+121.2 ± 35.7 vs. 42.9 ± 11.3%; P = 0.004). For all HRV parameters, rE ranged between re and Re values. Low frequency/high frequency changes were linked with visceral fat loss only in re (coefficient 5.9, 95% CI 1.9-10.0; P = 0.004). By day 21, HRV parameters of MetS groups (heart rate -8.6 ± 1.0%, standard deviation of R-R intervals + 34.0 ± 6.6%, total power + 63.3 ± 11.1%; P < 0.001) became closer to values of 50 aged-matched healthy controls. Conclusions A 3-week residential programme with intensive volumes of physical activity (15-20 hours per week) enhanced HRV in individuals with MetS. Participants with moderate intensity of training had greater improvements in sympathovagal balance, whereas those with high intensity in resistance training had greater decreases in heart rate and greater increases in very low frequency. Modality-specific relationships were observed between enhanced HRV

  10. Deuterium isotope effects on toluene metabolism. Product release as a rate-limiting step in cytochrome P-450 catalysis

    Energy Technology Data Exchange (ETDEWEB)

    Ling, K.H.; Hanzlik, R.P.

    1989-04-28

    Liver microsomes from phenobarbital-induced rats oxidize toluene to a mixture of benzyl alcohol plus o-, m- and p-cresol (ca. 69:31). Stepwise deuteration of the methyl group causes stepwise decreases in the yield of benzyl alcohol relative to cresols (ca. 24:76 for toluene-d3). For benzyl alcohol formation from toluene-d3 DV = 1.92 and D(V/K) = 3.53. Surprisingly, however, stepwise deuteration induces stepwise increases in total oxidation, giving rise to an inverse isotope effect overall (DV = 0.67 for toluene-d3). Throughout the series (i.e. d0, d1, d2, d3) the ratios of cresol isomers remain constant. These results are interpreted in terms of product release for benzyl alcohol being slower than release of cresols (or their epoxide precursors), and slow enough to be partially rate-limiting in turnover. Thus metabolic switching to cresol formation causes a net acceleration of turnover.

  11. Elevated trace element concentrations and standard metabolic rate in banded water snakes (Nerodia fasciata) exposed to coal combustion wastes

    Energy Technology Data Exchange (ETDEWEB)

    Hopkins, W.A.; Rowe, C.L.; Congdon, J.D. [Savannah River Ecology Laboratory, Aiken, SC (United States)

    1999-06-01

    Trace element concentrations in banded water snakes, Nerodia fasciata, and representative prey items from a site polluted by coal combustion wastes were compared with concentrations in conspecifics from a nearby reference site. Water snakes accumulated high concentrations of trace elements, especially arsenic (As) and selenium (Se), in the polluted habitat. In addition to being exposed to contaminants in water and sediments, snakes in the polluted site are exposed to contaminants by ingesting prey items that have elevated whole-body concentrations of trace elements, including As, cadmium (Cd), and Se. Snakes from the polluted site exhibited mean standard metabolic rates (SMR) 32% higher than snakes from the reference site. As a result, snakes from the polluted site appear to have elevated allocation of energy to maintenance and theoretically should have less energy available for growth, reproduction, and storage. It is hypothesized that long-term exposure to coal ash-derived trace elements and the resultant accumulation of some elements are responsible for observed increases in SMR.

  12. The association of ruminal pH and some metabolic parameters with conception rate at first artificial insemination in Thai dairy cows

    NARCIS (Netherlands)

    Inchaisri, C.; Somchai Chantsavang,; Noordhuizen, J.P.T.M.; Hogeveen, H.

    2013-01-01

    The objective of this study was to determine the association of metabolic parameters and cow associated factors with the conception rate at first insemination (FCR) in Thai dairy cows. The investigation was performed with 529 lactations from 32 smallholder dairy farms. At 3–6 weeks after parturition

  13. Locomotor, Heart-Rate, and Metabolic Power Characteristics of Youth Women's Field Hockey: Female Athletes in Motion (FAiM) Study

    Science.gov (United States)

    Vescovi, Jason D.

    2016-01-01

    Purpose: The purpose of this study was to quantify the locomotor, heart-rate, and metabolic power characteristics of high-level youth female field hockey matches. Method: Players from the U21 and U17 Canadian women's national teams were monitored during a 4-match test series using Global Positioning System technology. Position (forward,…

  14. Primed-infusion technique for rapid estimation of the metabolic clearance rate of 1,25(OH)/sub 2/D/sub 3/

    Energy Technology Data Exchange (ETDEWEB)

    Eastell, R.; Riggs, B.L.; Kumar, R.

    1987-09-01

    The authors have developed a rapid primed-infusion technique for the measurement of the metabolic clearance and production rate of 1,25-dihydroxyvitamin D/sub 3/ in normal human subjects and experimental animals. With this method, an estimate of the metabolic clearance rate of 1,25-dihydroxyvitamin D/sub 3/ can generally be made within 3 to 4 h. Initial studies in five dogs using 1,25-(/sup 3/H)-dihydroxyvitamin D/sub 3/ allowed us to determine the optimal ratio of loading dose to infusion rate that resulted in the most rapid attainment of steady-state levels of plasma radioactivity. By use of this technique they found that the metabolic clearance rate of 1,25-dihydroxyvitamin D/sub 3/ in dogs was 6.3 +/- 1.2 ml/min; the production rate of the hormone was 0.40 +/- 0.25 ..mu..g/day. In eight normal women, aged 28-51 yr, the metabolic clearance rate for 1,25-dihydroxyvitamin D/sub 3/ was 25.9 +/- 4.7 ml/min; the production rate was 1.38 +/- 0.45 ..mu..g/day. The advantages of this method relative to ones used in the past are that it can be performed quickly (generally within 3-4 h) with the use of only tracer amounts of this hormone (equivalent to 1.1% of the production rate). With this method, no assumptions about the most appropriate model to which to fit the data need to be made. Because of its rapidity, no metabolites of the injected 1,25-dihydroxyvitamin D/sub 3/ are formed during the study interval.

  15. Perceived exertion and heart rate models for estimating metabolic workload in elite British soldiers performing a backpack load-carriage task.

    Science.gov (United States)

    Simpson, Richard J; Graham, Scott M; Florida-James, Geraint D; Connaboy, Christopher; Clement, Richard; Jackson, Andrew S

    2010-10-01

    Identifying field measures to estimate backpack load-carriage work intensity in elite soldiers is of interest to the military. This study developed rating of perceived exertion (RPE) and heart rate models to define metabolic workload for a backpack load-carriage task valid for a population of elite soldiers using serial data. Male soldiers (n = 18) from the British Parachute or Special Air Service Regiment completed an incremental treadmill walking and (or) running protocol while carrying a 20-kg backpack. Heart rate, RPE, and oxygen uptake were recorded at each incremental stage of the protocol. Linear mixed models were used to model the RPE and heart rate data in the metric of measured peak oxygen uptake. Workload was accurately estimated using RPE alone (SE = 6.03), percentage of estimated maximum heart rate (%E-MHR) (SE = 6.9), and percentage of measured maximum heart rate (%M-MHR) (SE = 4.9). Combining RPE and %E-MHR resulted in a field measure with an accuracy (SE = 4.9) equivalent to the %M-MHR model. We conclude that RPE, %E-MHR, and %M-MHR provide accurate field-based proxy measures of metabolic workload in elite British soldiers performing a backpack load-carriage task. The model is accurate for the metabolic range measured by these serial data for the backpack load-carriage task.

  16. Omega-3 Fatty Acid Supplementation for 12 Weeks Increases Resting and Exercise Metabolic Rate in Healthy Community-Dwelling Older Females.

    Directory of Open Access Journals (Sweden)

    Samantha L Logan

    Full Text Available Critical among the changes that occur with aging are decreases in muscle mass and metabolic rate and an increase in fat mass. These changes may predispose older adults to chronic disease and functional impairment; ultimately resulting in a decrease in the quality of life. Research has suggested that long chain omega-3 fatty acids, found predominantly in fatty fish, may assist in reducing these changes. The objective of this study was to evaluate the effect of fish oil (FO supplementation in a cohort of healthy, community-dwelling older females on 1 metabolic rate and substrate oxidation at rest and during exercise; 2 resting blood pressure and resting and exercise heart rates; 3 body composition; 4 strength and physical function, and; 5 blood measures of insulin, glucose, c-reactive protein, and triglycerides. Twenty-four females (66 ± 1 yr were recruited and randomly assigned to receive either 3g/d of EPA and DHA or a placebo (PL, olive oil for 12 wk. Exercise measurements were taken before and after 12 wk of supplementation and resting metabolic measures were made before and at 6 and 12 wk of supplementation. The results demonstrated that FO supplementation significantly increased resting metabolic rate by 14%, energy expenditure during exercise by 10%, and the rate of fat oxidation during rest by 19% and during exercise by 27%. In addition, FO consumption lowered triglyceride levels by 29% and increased lean mass by 4% and functional capacity by 7%, while no changes occurred in the PL group. In conclusion, FO may be a strategy to improve age-related physical and metabolic changes in healthy older females. Trial registration: ClinicalTrials.gov NCT01734538.

  17. Adenosine mediates decreased cerebral metabolic rate and increased cerebral blood flow during acute moderate hypoxia in the near-term fetal sheep.

    Science.gov (United States)

    Blood, Arlin B; Hunter, Christian J; Power, Gordon G

    2003-12-15

    Exposure of the fetal sheep to moderate to severe hypoxic stress results in both increased cortical blood flow and decreased metabolic rate. Using intravenous infusion of 8-cyclopentyl-1,3-dipropylxanthine (DPCPX), a selective adenosine A1 receptor antagonist that is permeable to the blood brain barrier, we examine the role of adenosine A1 receptors in mediating cortical blood flow and metabolic responses to moderate hypoxia. The effects of DPCPX blockade are compared to controls as well as animals receiving intravenous 8-(p-sulfophenyl)-theophylline) (8-SPT), a non-selective adenosine receptor antagonist which has been found to be blood brain barrier impermeable. Laser Doppler flow probes, tissue PO2, and thermocouples were implanted in the cerebral cortices of near-term fetal sheep. Catheters were placed in the brachial artery and sagittal sinus vein for collection of samples for blood gas analysis. Three to seven days later responses to a 30-min period of fetal hypoxemia (arterial PO2 10-12 mmHg) were studied with administration of 8-SPT, DPCPX, or vehicle. Cerebral metabolic rate was determined by calculation of both brain heat production and oxygen consumption. In response to hypoxia, control experiments demonstrated a 42 +/- 7 % decrease in cortical heat production and a 35 +/- 10 % reduction in oxygen consumption. In contrast, DPCPX infusion during hypoxia resulted in no significant change in brain heat production or oxygen consumption, suggesting the adenosine A1 receptor is involved in lowering metabolic rate during hypoxia. The decrease in cerebral metabolic rate was not altered by 8-SPT infusion, suggesting that the response is not mediated by adenosine receptors located outside the blood brain barrier. In response to hypoxia, control experiments demonstrated a 35 +/- 7 % increase in cortical blood flow. DPCPX infusion did not change this increase in cortical blood flow, however 8-SPT infusion attenuated increases in flow, indicating that hypoxic

  18. Brain and high metabolic rate organ mass: contributions to resting energy expenditure beyond fat-free mass1234

    Science.gov (United States)

    Javed, Fahad; He, Qing; Davidson, Lance E; Thornton, John C; Albu, Jeanine; Boxt, Lawrence; Krasnow, Norman; Elia, Marinos; Kang, Patrick; Heshka, Stanley

    2010-01-01

    Background: The degree to which interindividual variation in the mass of select high metabolic rate organs (HMROs) mediates variability in resting energy expenditure (REE) is unknown. Objective: The objective was to investigate how much REE variability is explained by differences in HMRO mass in adults and whether age, sex, and race independently predict REE after adjustment for HMRO. Design: A cross-sectional evaluation of 55 women [30 African Americans aged 48.7 ± 22.2 y (mean ± SD) and 25 whites aged 46.4 ± 17.7 y] and 32 men (8 African Americans aged 34.3 ± 18.2 y and 24 whites aged 51.3 ± 20.6 y) was conducted. Liver, kidney, spleen, heart, and brain masses were measured by magnetic resonance imaging, and fat and fat-free mass (FFM) were measured by dual-energy X-ray absorptiometry. REE was measured by indirect calorimetry. Results: REE estimated from age (P = 0.001), race (P = 0.006), sex (P = 0.31), fat (P = 0.001), and FFM (P brain (P = 0.006) to the model increased the explained variance to 75% and rendered the contributions of age, sex, and race statistically nonsignificant, whereas fat and FFM continued to make significant contributions (both P brain to the model rendered the intercept (69 kcal · kg−1 · d−1) consistent with zero, which indicated zero REE for zero body mass. Conclusions: Relatively small interindividual variation in HMRO mass significantly affects REE and reduces the role of age, race, and sex in explaining REE. Decreases in REE with increasing age may be partly related to age-associated changes in the relative size of FFM components. PMID:20164308

  19. Effect of postprandial hyperglycaemia in non-invasive measurement of cerebral metabolic rate of glucose in non-diabetic subjects

    Energy Technology Data Exchange (ETDEWEB)

    Tsuchida, Tatsuro; Itoh, Harumi [Department of Radiology, Fukui Medical University, Matsuoka (Japan); Sadato, Norihiro; Nishizawa, Sadahiko; Yonekura, Yoshiharu [Biomedical Imaging Research Center, Fukui Medical University (Japan)

    2002-02-01

    The aim of this study was to determine the effect of postprandial hyperglycaemia (HG) on the non-invasive measurement of cerebral metabolic rate of glucose (CMRGlc). Five patients who had a meal within an hour before a fluorine-18 fluorodeoxyglucose positron emission tomography (FDG-PET) examination were recruited in this study. They underwent intermittent arterial blood sampling (measured input function), and, based on this sampling, CMRGlc was calculated using an autoradiographic method (CMRGlc{sub real}). Simulated input functions were generated based on standardised input function, body surface area and net injected dose of FDG, and simulated CMRGlc (CMRGlc{sub sim}) was also calculated. Percent error of the area under the curve (AUC) between measured (AUC{sub real}) and simulated input function (AUC{sub IFsim}) and percent error between CMRGlc{sub real} and CMRGlc{sub sim} were calculated. These values were compared with those obtained from a previous study conducted under fasting conditions (F). The serum glucose level in the HG group was significantly higher than that in the F group (165{+-}69 vs 100{+-}9 mg/dl, P=0.0007). Percent errors of AUC and CMRGlc in grey matter and white matter in HG were significantly higher than those in F (12.9%{+-}1.3% vs 3.5%{+-}2.2% in AUC, P=0.0015; 18.2%{+-}2.2% vs 2.9%{+-}1.9% in CMRGlc in grey matter, P=0.0028; 24.0%{+-}4.6% vs 3.4%{+-}2.2% in CMRGlc in white matter, P=0.0028). It is concluded that a non-invasive method of measuring CMRGlc should be applied only in non-diabetic subjects under fasting conditions. (orig.)

  20. Effect of Ambient Temperature on Body Temperature and Rest Metabolic Rate in Apodemus chevrieri During Postnatal Development

    Directory of Open Access Journals (Sweden)

    Zhu Wan-long

    2014-05-01

    Full Text Available In order to investigate the ability of constant temperature and thermoregulation in Apodemus chevrieri, body temperature and rest metabolic rate (RMR were measured during postnatal development (1~42 day when the A. chevrieri exposed different ambient temperature. The result showed that: body temperature and RMR of pups in A. chevrieri increased according to the increase of ambient temperature during 1 day to 7 day, showed character of poikilotherms; body temperature of pups were lower in low temperature(5oC and 10oC, relatively and RMR significant increased when day age is 14 day, it indicated that the pups showed a certain degree of thermoregulation in this phase. Its thermoregulation ability developed quickly during 7 day to 14 day. RMR of pups was extreme significantly higher in low temperature than that in other temperature when day age was 21 day, it showed that the pups had some thermoregulation to low temperature stimulation. The RMR of pups was showed increasing trend in high temperature(35oC when 28 day; when day age was 35 day and 42 day, the thermal neutral zone were 22.5 to 30oC and approaching its adult level. All of these results indicated that pups of A. chevrieri in the different growing period had different thermogenesis and energy allocation to maintain stable to body temperature, thermogenesis was weaker in the early phase of postnatal development, most of energy is used to its growth. After pups were weaned, the ability of constant temperature and thermoregulation developed quickly to adjust variations of environment during postnatal development.

  1. Effects of dietary Gracilaria sp. and Alaria sp. supplementation on growth performance, metabolic rates and health in meagre (Argyrosomus regius) subjected to pathogen infection

    DEFF Research Database (Denmark)

    Peixoto, Maria João; Salas-Leitón, Emílio; Brito, Francisca;

    2016-01-01

    Effects of dietary seaweed supplementation on basal physiology and health biomarkers were assessed in meagre (Argyrosomus regius) subjected to bacterial infection, using Photobacterium damselae subsp. Piscicida (Phdp) as the etiologic agent. Three test diets were prepared by supplementing a basal...

  2. Concentrated insulins: the new basal insulins

    Directory of Open Access Journals (Sweden)

    Lamos EM

    2016-03-01

    Full Text Available Elizabeth M Lamos,1 Lisa M Younk,2 Stephen N Davis3 1Division of Endocrinology, Diabetes and Nutrition, 2Department of Medicine, University of Maryland School of Medicine, 3Department of Medicine, University of Maryland Medical Center, Baltimore, MD, USA Introduction: Insulin therapy plays a critical role in the treatment of type 1 and type 2 diabetes mellitus. However, there is still a need to find basal insulins with 24-hour coverage and reduced risk of hypoglycemia. Additionally, with increasing obesity and insulin resistance, the ability to provide clinically necessary high doses of insulin at low volume is also needed. Areas covered: This review highlights the published reports of the pharmacokinetic (PK and glucodynamic properties of concentrated insulins: Humulin-R U500, insulin degludec U200, and insulin glargine U300, describes the clinical efficacy, risk of hypoglycemic, and metabolic changes observed, and finally, discusses observations about the complexity of introducing a new generation of concentrated insulins to the therapeutic market. Conclusion: Humulin-R U500 has a similar onset but longer duration of action compared with U100 regular insulin. Insulin glargine U300 has differential PK/pharmacodynamic effects when compared with insulin glargine U100. In noninferiority studies, glycemic control with degludec U200 and glargine U300 is similar to insulin glargine U100 and nocturnal hypoglycemia is reduced. Concentrated formulations appear to behave as separate molecular entities when compared with earlier U100 insulin analog compounds. In the review of available published data, newer concentrated basal insulins may offer an advantage in terms of reduced intraindividual variability as well as reducing the injection burden in individuals requiring high-dose and large volume insulin therapy. Understanding the PK and pharmacodynamic properties of this new generation of insulins is critical to safe dosing, dispensing, and administration

  3. The human airway epithelial basal cell transcriptome.

    Directory of Open Access Journals (Sweden)

    Neil R Hackett

    Full Text Available BACKGROUND: The human airway epithelium consists of 4 major cell types: ciliated, secretory, columnar and basal cells. During natural turnover and in response to injury, the airway basal cells function as stem/progenitor cells for the other airway cell types. The objective of this study is to better understand human airway epithelial basal cell biology by defining the gene expression signature of this cell population. METHODOLOGY/PRINCIPAL FINDINGS: Bronchial brushing was used to obtain airway epithelium from healthy nonsmokers. Microarrays were used to assess the transcriptome of basal cells purified from the airway epithelium in comparison to the transcriptome of the differentiated airway epithelium. This analysis identified the "human airway basal cell signature" as 1,161 unique genes with >5-fold higher expression level in basal cells compared to differentiated epithelium. The basal cell signature was suppressed when the basal cells differentiated into a ciliated airway epithelium in vitro. The basal cell signature displayed overlap with genes expressed in basal-like cells from other human tissues and with that of murine airway basal cells. Consistent with self-modulation as well as signaling to other airway cell types, the human airway basal cell signature was characterized by genes encoding extracellular matrix components, growth factors and growth factor receptors, including genes related to the EGF and VEGF pathways. Interestingly, while the basal cell signature overlaps that of basal-like cells of other organs, the human airway basal cell signature has features not previously associated with this cell type, including a unique pattern of genes encoding extracellular matrix components, G protein-coupled receptors, neuroactive ligands and receptors, and ion channels. CONCLUSION/SIGNIFICANCE: The human airway epithelial basal cell signature identified in the present study provides novel insights into the molecular phenotype and biology of

  4. Triple-negative breast cancer with brain metastases: a comparison between basal-like and non-basal-like biological subtypes

    NARCIS (Netherlands)

    A. Niwińska (Anna); W. Olszewski (Wojciech); M. Murawska (Magdalena); K. Pogoda (Katarzyna)

    2011-01-01

    textabstractThe aim of this study was to divide the group of triple-negative breast cancer patients with brain metastases into basal-like and non-basal-like biological subtypes in order to compare clinical features and survival rates in those two groups. A comprehensive analysis of 111 consecutive t

  5. Optimizing the distribution of resources between enzymes of carbon metabolism can dramatically increase photosynthetic rate: a numerical simulation using an evolutionary algorithm.

    Science.gov (United States)

    Zhu, Xin-Guang; de Sturler, Eric; Long, Stephen P

    2007-10-01

    The distribution of resources between enzymes of photosynthetic carbon metabolism might be assumed to have been optimized by natural selection. However, natural selection for survival and fecundity does not necessarily select for maximal photosynthetic productivity. Further, the concentration of a key substrate, atmospheric CO(2), has changed more over the past 100 years than the past 25 million years, with the likelihood that natural selection has had inadequate time to reoptimize resource partitioning for this change. Could photosynthetic rate be increased by altered partitioning of resources among the enzymes of carbon metabolism? This question is addressed using an "evolutionary" algorithm to progressively search for multiple alterations in partitioning that increase photosynthetic rate. To do this, we extended existing metabolic models of C(3) photosynthesis by including the photorespiratory pathway (PCOP) and metabolism to starch and sucrose to develop a complete dynamic model of photosynthetic carbon metabolism. The model consists of linked differential equations, each representing the change of concentration of one metabolite. Initial concentrations of metabolites and maximal activities of enzymes were extracted from the literature. The dynamics of CO(2) fixation and metabolite concentrations were realistically simulated by numerical integration, such that the model could mimic well-established physiological phenomena. For example, a realistic steady-state rate of CO(2) uptake was attained and then reattained after perturbing O(2) concentration. Using an evolutionary algorithm, partitioning of a fixed total amount of protein-nitrogen between enzymes was allowed to vary. The individual with the higher light-saturated photosynthetic rate was selected and used to seed the next generation. After 1,500 generations, photosynthesis was increased substantially. This suggests that the "typical" partitioning in C(3) leaves might be suboptimal for maximizing the light

  6. The basal ganglia and apraxia.

    Science.gov (United States)

    Pramstaller, P P; Marsden, C D

    1996-02-01

    Ever since Liepmann's original descriptions at the beginning of the century apraxia has usually been attributed to damage confined to the cerebral cortex and/or cortico-cortical connecting pathways. However, there have been suggestions that apraxia can be due to deep subcortical lesions, which raises the question as to whether damage to the basal ganglia or thalamus can cause apraxia. We therefore analysed 82 cases of such 'deep' apraxias reported in the literature. These reports consisted of a small number (n=9) of cases studied neuropathologically, and a much larger group (n=73) in which CT or MRI was used to identify the size and extent of the lesion. The reports were subdivided into (i) those with small isolated lesions which involved nuclei of the basal ganglia or thalamus only, and not extending to involve periventricular or peristriatal white matter; (ii) those with large lesions which involved two or more of the nuclei, or one or more of these deep structures plus damage to closely adjacent areas including the internal capsule, periventricular or peristriatal white matter; and (iii) lesions sparing basal ganglia and thalamus but involving adjacent white matter. The main conclusions to be drawn from this meta-analysis are that lesions confined to the basal ganglia (putamen, caudate nucleus and globus pallidus) rarely, if ever, cause apraxia. Lesions affecting the lenticular nucleus or putamen nearly always intruded into the adjacent lateral white matter to involve association fibres, in particular those of the superior longitudinal fasciculus and frontostriatal connections. Apraxia occurred with deep lesions of the basal ganglia apparently sparing white matter in only eight out of the 82 cases. Apraxia was most commonly seen when there were lesions in the lenticular nucleus or putamen (58 out of 72 cases) with additional involvement of capsular, and particularly of periventricular or peristriatal, white matter. Lesions of the globus pallidus (no cases) or

  7. Effects of Impaired Glucose Metabolism on Heart Rate Variability and Blood Pessure Variability in Essential Hpertensive Patients

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    To investigate the effects of impaired glucose metabolism (IGM) on cardiovascular autonomic nervous systems in essential hypertensive (EH) patients by comparing heart rate variability (HRV) and blood pressure variability (BPV) in EH patients with or without type 2 diabetes mellitus (T2DM). Simultaneous 24-h recordings of ambulatory ECG and blood pressure monitoring were performed in 36 male old patients with simple EH and 33 male old patients with EH combined with T2DM. HRV analysis included time domain parameters such as SDNN, SDANN, SDNNi, rMSSD and pNN50, and total spectral power (TP) of HRV, which mainly consists of VLF, LF and HF component along with LF/HF ratio, was also obtained. The value of ambulatory blood pressure was represented as the mean blood pressure (mean systolic/mSBP, diastolic/mDBP and pulse pressure/mPP)during different periods (24 h/24 h, day time/d and night time/n). Standard deviation (SD) as well as coefficient of variance (CV) of blood pressure during each above-mentioned period were obtained to reflect the long-term BPV. Our result showed that SDNN, SDNNi, SDANN, rMSSD, PNN50, TP and HF of HRV in cases of EH with T2DM were all significantly lower than those in simple EH subjects (P<0.05). No significant differences in VLF or LF was found between the two groups (P>0.05), while LF/HF ratio was significantly higher in EH with T2DM patients than in simple EH subjects (P<0.01).Moreover, dmSBP, 24 h-mPP and dmPP were all significantly higher in EH with T2DM patients than in simple EH subjects (P<0.05), while nmSBP, 24 h-mSBP, 24 h-mDBP, dmDBP, nmDBP or nmPP showed no significant difference between this two groups of patients (P>0.05). And dSBPSD,dSBPCV and 24 h-SBPSD were all significantly higher in EH with T2DM patients than in simple EH subjects (P<0.05), while the other BPV indexes showed no significant difference between this two groups (P>0.05). It is concluded that the cardiovascular autonomic nervous systems in EH patients

  8. Effects of supplemental fish oil on resting metabolic rate, body composition, and salivary cortisol in healthy adults

    Directory of Open Access Journals (Sweden)

    Pabon Vanessa A

    2010-10-01

    Full Text Available Abstract Background To determine the effects of supplemental fish oil (FO on resting metabolic rate (RMR, body composition, and cortisol production in healthy adults. Methods A total of 44 men and women (34 ± 13y, mean+SD participated in the study. All testing was performed first thing in the morning following an overnight fast. Baseline measurements of RMR were measured using indirect calorimetry using a facemask, and body composition was measured using air displacement plethysmography. Saliva was collected via passive drool and analyzed for cortisol concentration using ELISA. Following baseline testing, subjects were randomly assigned in a double blind manner to one of two groups: 4 g/d of Safflower Oil (SO; or 4 g/d of FO supplying 1,600 mg/d eicosapentaenoic acid (EPA and 800 mg/d docosahexaenoic acid (DHA. All tests were repeated following 6 wk of treatment. Pre to post differences were analyzed using a treatment X time repeated measures ANOVA, and correlations were analyzed using Pearson's r. Results Compared to the SO group, there was a significant increase in fat free mass following treatment with FO (FO = +0.5 ± 0.5 kg, SO = -0.1 ± 1.2 kg, p = 0.03, a significant reduction in fat mass (FO = -0.5 ± 1.3 kg, SO = +0.2 ± 1.2 kg, p = 0.04, and a tendency for a decrease in body fat percentage (FO = -0.4 ± 1.3% body fat, SO = +0. 3 ± 1.5% body fat, p = 0.08. No significant differences were observed for body mass (FO = 0.0 ± 0.9 kg, SO = +0.2 ± 0.8 kg, RMR (FO = +17 ± 260 kcal, SO = -62 ± 184 kcal or respiratory exchange ratio (FO = -0.02 ± 0.09, SO = +0.02 ± 0.05. There was a tendency for salivary cortisol to decrease in the FO group (FO = -0.064 ± 0.142 μg/dL, SO = +0.016 ± 0.272 μg/dL, p = 0.11. There was a significant correlation in the FO group between change in cortisol and change in fat free mass (r = -0.504, p = 0.02 and fat mass (r = 0.661, p = 0.001. Conclusion 6 wk of supplementation with FO significantly increased

  9. Migraine attacks the Basal Ganglia

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    Bigal Marcelo

    2011-09-01

    Full Text Available Abstract Background With time, episodes of migraine headache afflict patients with increased frequency, longer duration and more intense pain. While episodic migraine may be defined as 1-14 attacks per month, there are no clear-cut phases defined, and those patients with low frequency may progress to high frequency episodic migraine and the latter may progress into chronic daily headache (> 15 attacks per month. The pathophysiology of this progression is completely unknown. Attempting to unravel this phenomenon, we used high field (human brain imaging to compare functional responses, functional connectivity and brain morphology in patients whose migraine episodes did not progress (LF to a matched (gender, age, age of onset and type of medication group of patients whose migraine episodes progressed (HF. Results In comparison to LF patients, responses to pain in HF patients were significantly lower in the caudate, putamen and pallidum. Paradoxically, associated with these lower responses in HF patients, gray matter volume of the right and left caudate nuclei were significantly larger than in the LF patients. Functional connectivity analysis revealed additional differences between the two groups in regard to response to pain. Conclusions Supported by current understanding of basal ganglia role in pain processing, the findings suggest a significant role of the basal ganglia in the pathophysiology of the episodic migraine.

  10. Behaviour in a standardized assay, but not metabolic or growth rate, predicts behavioural variation in an adult aquatic top predator Esox lucius in the wild.

    Science.gov (United States)

    Laskowski, K L; Monk, C T; Polverino, G; Alós, J; Nakayama, S; Staaks, G; Mehner, T; Arlinghaus, R

    2016-04-01

    This study tested for links among behaviour, state and life-history variables as predicted by the pace-of-life hypothesis in adult pike Esox lucius. First, a standardized open-field behavioural assay was developed to assess individual behaviour of wild-captured adult E. lucius. Behaviour within the standardized assay predicted swimming behaviour in the lake, providing an ecological validation of the assay. There was no relationship between standardized behaviour and any of the life-history and state variables, including metabolism, body condition, juvenile growth rate and adult growth rate in contrast to predictions from the pace-of-life hypothesis. This study demonstrates that it is possible to assess ecologically relevant behavioural variation in a large-bodied top predator using a standard open-field assay, but it is noteworthy that this standardized behaviour is not systematically related to standard metabolism or growth.

  11. Increased metabolic rate in obese women after ingestion of potassium, magnesium- and phosphate-enriched orange juice or injection of ephedrine.

    Science.gov (United States)

    Jaedig, S; Henningsen, N C

    1991-06-01

    Thirty-six obese, pre-menopausal women were studied after an overnight fast and randomized to four different regimens of metabolic stimuli: group I (n = 12), 100 ml orange juice with dissolved K- and Mg-phosphates (K, 40 mmol; Mg, 17.5 mmol; HPO4, 35 mmol); group II (n = 8), 100 ml of water with electrolytes as in group I; group III (n = 8), 100 ml of orange juice; group IV (n = 8), injection of ephedrine intravenously, 0.25 mg/kg body weight. The women in groups I, II and III were further stimulated with ephedrine as in group IV and new measurements made. Thirty minutes after the first stimulus VO2, VCO2 and energy expenditure (EE) rose significantly (13.1-16.5 per cent) in groups I and IV only. In groups I and III the blood concentrations of glucose, insulin, and C-peptide rose significantly. After the second stimulus (ephedrine i.v.) no further increase in VO2, VCO2 and EE occurred in group I, but the increases from basal values became significant in group III. In all women at baseline, whole-body potassium was significantly correlated to VO2. Serum-magnesium was negatively correlated to A/I weight (actual/ideal weight). We conclude that the addition of K- and Mg-phosphates to glucose increases the postprandial thermogenesis in obese patients.

  12. Multiple scales of temporal variability in ecosystem metabolism rates: results from two years of continuous monitoring in a forested headwater stream

    Energy Technology Data Exchange (ETDEWEB)

    Roberts, Brian J [ORNL; Mulholland, Patrick J [ORNL; Hill, Walter [ORNL

    2007-01-01

    Headwater streams are key sites of nutrient and organic matter processing and retention, but little is known about temporal variability in gross primary production (GPP) and ecosystem respiration (ER) rates as a result of the short duration of most ecosystem metabolism measurements in lotic ecosystems. We examined temporal variability and controls on ecosystem metabolism by measuring daily rates continuously for two years in Walker Branch, a first-order deciduous forest stream. Four important scales of temporal variability in ecosystem metabolism rates were identified: (1) seasonal, (2) day-to-day, (3) episodic (storm-related), and (4) inter-annual. Seasonal patterns were largely controlled by the leaf phenology and productivity of the deciduous riparian forest. Walker Branch was strongly net heterotrophic throughout the year with the exception of the open-canopy spring when GPP and ER rates were similar. Day-to-day variability in weather conditions influenced light reaching the streambed, resulting in high day-to-day variability in GPP particularly during spring (daily light levels explained 84% of the variance in daily GPP in April). Episodic storms depressed GPP for several days in spring, but increased GPP in autumn by removing leaves shading the streambed. Storms depressed ER initially, but then stimulated ER to 2-3 times pre-storm levels for several days. Walker Branch was strongly net heterotrophic in both years of the study (NEP = -1156 and -773 g O2 m-2 y-1), with annual GPP being similar (488 and 519 g O2 m-2 y-1) but annual ER being higher in 2004 than 2005 (-1645 vs. -1292 g O2 m-2 y-1). Inter-annual variability in ecosystem metabolism (assessed by comparing 2004 and 2005 rates with previous measurements) was the result of the storm frequency and timing and the size of the spring macroalgal bloom. Changes in local climate can have substantial impacts on stream ecosystem metabolism rates and ultimately influence the carbon source and sink properties of

  13. Unstimulated salivary flow rate, pH and buffer capacity of saliva in healthy volunteers Débito basal, pH y capacidad tampón de la secreción salivar en sujetos sanos

    Directory of Open Access Journals (Sweden)

    C. Fenoll-Palomares

    2004-11-01

    Full Text Available Objectives: to assess the salivary flow rate, pH, and buffer capacity of healthy volunteers, and their relationships with age, gender, obesity, smoking, and alcohol consumption, and to establish the lower-end value of normal salivary flow (oligosialia. Methods: a prospective study was conducted in 159 healthy volunteers (age > 18 years, absence of medical conditions that could decrease salivary flow. Unstimulated whole saliva was collected during ten minutes, and salivary flow rate (ml/min, pH, and bicarbonate concentration (mmol/l were measured using a Radiometer ABL 520. The 5 percentile of salivary flow rate and bicarbonate concentration was considered the lower limit of normality. Results: median salivary flow rate was 0.48 ml/min (range: 0.1-2 ml/min. Age younger than 44 years was associated with higher flow rates (OR 2.10. Compared with women, men presented a higher flow rate (OR 3.19 and buffer capacity (OR 2.81. Bicarbonate concentration correlated with salivary flow rate. The lower-end values of normal flow rate and bicarbonate concentration were 0.15 ml/min and 1.800 mmol/l, respectively. The presence of obesity, smoking, and alcohol consumption did not influence salivary parameters. Conclusions: in healthy volunteers, salivary flow rate depends on age and gender, and correlates with buffer capacity. Obesity, smoking, and alcohol use do not influence salivary secretion.Objetivos: conocer el débito, pH y capacidad tampón de la saliva en sujetos sanos y sus relaciones con edad, sexo, obesidad y hábitos tabáquico y alcohólico, así como establecer la definición de hiposialia. Métodos: estudio observacional prospectivo en 159 voluntarios sanos (> 18 años, sin factores conocidos que disminuyan la secreción salivar. Se ha recogido la saliva total, sin estímulo, durante 10 minutos, determinando su débito (ml/min, pH y capacidad tampón (concentración de bicarbonato en mmol/l mediante autoanalizador Radiometer ABL 520. Se han

  14. Identical metabolic rate and thermal conductance in Rock Sandpiper (Calidris ptilocnemis) subspecies with contrasting nonbreeding life histories

    NARCIS (Netherlands)

    Ruthrauff, Dan; Dekinga, Anne; Gill, Robert E.; Piersma, Theunis

    2013-01-01

    Closely related species or subspecies can exhibit metabolic differences that reflect site-specific environmental conditions. Whether such differences represent fixed traits or flexible adjustments to local conditions, however, is difficult to predict across taxa. The nominate race of Rock Sandpiper

  15. Assessment of metabolic properties and kinetic parameters of methanogenic sludge by on-line methane production rate measurements

    NARCIS (Netherlands)

    Gonzalez-Gil, G.; Kleerebezem, R.; Lettinga, G.

    2002-01-01

    This report presents a new approach to studying the metabolic and kinetic properties of anaerobic sludge from single batch experiments. The two main features of the method are that the methane production is measured on-line with a relatively cheap system, and that the methane production data can be

  16. Metabolism and thermoregulation in the tree shrew, Tupaia belangeri

    Directory of Open Access Journals (Sweden)

    Lin Zhang

    2012-05-01

    Full Text Available Maximum metabolic rate is a physiological limitation that is an important for animals' survival, reproduction and geographic. Basal metabolic rate (BMR, nonshivering thermogenesis (NST, and maximum metabolic rate (MMR were measured was in a small mammal species, Tupaia belangeri, which is a unique species of small-bodied mammals in the Oriental realm. Thermal neutral zone (TNZ was 30 - 35°C and BMR was 1.38±0.09 ml g-1 h-1. NST and MMR were 2.64±0.08 ml g-1 h-1 and 7.14±0.38 ml g-1 h-1 in summer, respectively. The ecophysiological properties of relatively high body temperature, wide TNZ, low BMR and thermogenic capacity enable this species to adapt to its environment.

  17. Evaluation of Basal Serum Adrenocorticotropic Hormone and Cortisol Levels and Their Relationship with Nonalcoholic Fatty Liver Disease in Male Patients with Idiopathic Hypogonadotropic Hypogonadism

    Institute of Scientific and Technical Information of China (English)

    Wen-Bo Wang; Fei She; Li-Fang Xie; Wen-Hua Yan; Jin-Zhi Ouyang; Bao-An Wang; Hang-Yun Ma

    2016-01-01

    Background:Prolonged gonadal hormone deficiency in patients with idiopathic hypogonadotropic hypogonadism (IHH) may produce adverse effects on the endocrine homeostasis and metabolism.This study aimed to compare basal serum adrenocorticotropic hormone (ACTH) and cortisol levels between male IHH patients and healthy controls.Moreover,this study compared the basal hypothalamic-pituitary-adrenal (HPA) axis in patients with and without nonalcoholic fatty liver disease (NAFLD),and also evaluated the relationship between basal HPA axis and NAFLD in male IHH patients.Methods:This was a retrospective case-control study involving 75 Chinese male IHH patients (mean age 21.4 ± 3.8 years,range 17-30 years) and 135 healthy controls after matching for gender and age.All subjects underwent physical examination and blood testing for serum testosterone,luteinizing hormone,follicle-stimulating hormone,ACTH,and cortisol and biochemical tests.Results:Higher basal serum ACTH levels (8.25 ± 3.78 pmol/L vs.6.97 ± 2.81 pmol/L) and lower cortisol levels (366.70 ± 142.48 nmol/L vs.452.82 ± 141.53 nmol/L) were observed in male IHH patients than healthy subjects (all P < 0.05).IHH patients also showed higher metabolism parameters and higher prevalence rate of NAFLD (34.9% vs.4.4%) than the controls (all P < 0.05).Basal serum ACTH (9.91 ± 4.98 pmol/L vs.7.60 ± 2.96 pmol/L) and dehydroepiandrosterone sulfate (2123.7 ± 925.8 μg/L vs.1417.1 ± 498.4 μg/L) levels were significantly higher in IHH patients with NAFLD than those without NAFLD (all P < 0.05).We also found that basal serum ACTH levels were positively correlated with NAFLD (r =0.289,P < 0.05) and triglyceride levels (r =0.268,P < 0.05) in male IHH patients.Furthermore,NAFLD was independently associated with ACTH levels in male IHH patients by multiple linear regression analysis.Conclusions:The male IHH patients showed higher basal serum ACTH levels and lower cortisol levels than matched healthy controls.NAFLD was

  18. Vismodegib (ERIVEDGE°) In basal cell carcinoma: too many unknowns.

    Science.gov (United States)

    2015-01-01

    Basal cell carcinomas are the most common skin cancers. They are usually localised and carry a good prognosis. There is no standard treatment for the rare patients with metastatic basal cell carcinoma or very extensive basal cell carcinoma for whom surgery or radiotherapy is inappropriate. Vismodegib, a cytotoxic drug, is claimed to prevent tumour growth by inhibiting a pathway involved in tissue repair and embryogenesis. It has been authorised in the European Union for patients with metastatic or locally advanced and extensive basal cell carcinoma. Clinical evaluation of vismodegib is based on a non-comparative clinical trial involving 104 patients, providing only weak evidence. Twenty-one months after the start of the trial, 7 patients with metastases (21%) and 6 patients with advanced basal cell carcinoma (10%) had died. Given the lack of a placebo group, there is no way of knowing whether vismodegib had any effect, positive or negative, on survival. There were no complete responses among patients with metastases, but about one-third of them had partial responses. Among the 63 patients with locally advanced basal cell carcinoma, there were 14 complete responses and 16 partial responses. The recurrence rate in patients with complete responses was not reported. Similar results were reported in two other uncontrolled trials available in mid-2014. Vismodegib has frequent and sometimes serious adverse effects, including muscle spasms, fatigue and severe hyponatraemia. Cases of severe weight loss, alopecia, ocular disorders, other cancers (including squamous cell carcinoma) and anaemia have also been reported. More data are needed on possible hepatic and cardiovascular adverse effects. A potent teratogenic effect was seen in experimental animals. As vismodegib enters semen, contraception is mandatory for both men (condoms) and women. In practice, vismodegib has frequent and varied adverse effects, some of which are serious, while its benefits are poorly documented

  19. Marine ice sheet model performance depends on basal sliding physics and sub-shelf melting

    Science.gov (United States)

    Gladstone, Rupert Michael; Warner, Roland Charles; Galton-Fenzi, Benjamin Keith; Gagliardini, Olivier; Zwinger, Thomas; Greve, Ralf

    2017-01-01

    Computer models are necessary for understanding and predicting marine ice sheet behaviour. However, there is uncertainty over implementation of physical processes at the ice base, both for grounded and floating glacial ice. Here we implement several sliding relations in a marine ice sheet flow-line model accounting for all stress components and demonstrate that model resolution requirements are strongly dependent on both the choice of basal sliding relation and the spatial distribution of ice shelf basal melting.Sliding relations that reduce the magnitude of the step change in basal drag from grounded ice to floating ice (where basal drag is set to zero) show reduced dependence on resolution compared to a commonly used relation, in which basal drag is purely a power law function of basal ice velocity. Sliding relations in which basal drag goes smoothly to zero as the grounding line is approached from inland (due to a physically motivated incorporation of effective pressure at the bed) provide further reduction in resolution dependence.A similar issue is found with the imposition of basal melt under the floating part of the ice shelf: melt parameterisations that reduce the abruptness of change in basal melting from grounded ice (where basal melt is set to zero) to floating ice provide improved convergence with resolution compared to parameterisations in which high melt occurs adjacent to the grounding line.Thus physical processes, such as sub-glacial outflow (which could cause high melt near the grounding line), impact on capability to simulate marine ice sheets. If there exists an abrupt change across the grounding line in either basal drag or basal melting, then high resolution will be required to solve the problem. However, the plausible combination of a physical dependency of basal drag on effective pressure, and the possibility of low ice shelf basal melt rates next to the grounding line, may mean that some marine ice sheet systems can be reliably simulated at

  20. Oxidative metabolism in insulin-treated gestational diabetes mellitus.

    Science.gov (United States)

    Hsu, H W; Butte, N F; Wong, W W; Moon, J K; Ellis, K J; Klein, P D; Moise, K J

    1997-06-01

    To investigate whether protein, carbohydrate, and fat metabolism was normalized in insulin-treated gestational diabetes mellitus (GDM), eight Hispanic women with GDM and eight healthy controls were studied at 32-36 wk of gestation and 6 wk postpartum. Net substrate utilization was measured using room respiration calorimetry. Exogenous substrate oxidation was determined by 13C recovered in breath CO2 from 13C-labeled leucine, glucose, and Hiolein. Women with GDM had higher 24-h oxygen consumption, carbon dioxide production, total energy expenditure, and basal metabolic rates than controls due to larger body mass. Adjusted for weight or fat-free mass, total energy expenditure, basal metabolic rate, and basal and 24-h whole body net protein, carbohydrate, and fat utilization did not differ between insulin-treated GDM subjects and controls in pregnancy or postpartum. Oxidation of [13C]leucine and [13C]glucose did not differ by group or pregnancy status. Recovery of exogenously administered [13C]Hiolein, a biosynthetic triglyceride, as breath 13CO2 was significantly lower in the GDM group antepartum and postpartum (P = 0.02), indicating lower oxidation of exogenous triglycerides in GDM.

  1. Idiopathic Basal Ganglia Calcification Presented with Impulse Control Disorder

    Science.gov (United States)

    Sahin, Cem; Levent, Mustafa; Akbaba, Gulhan; Kara, Bilge; Yeniceri, Emine Nese; Inanc, Betul Battaloglu

    2015-01-01

    Primary familial brain calcification (PFBC), also referred to as Idiopathic Basal Ganglia Calcification (IBGC) or “Fahr's disease,” is a clinical condition characterized by symmetric and bilateral calcification of globus pallidus and also basal ganglions, cerebellar nuclei, and other deep cortical structures. It could be accompanied by parathyroid disorder and other metabolic disturbances. The clinical features are dysfunction of the calcified anatomic localization. IBGC most commonly presents with mental damage, convulsion, parkinson-like clinical picture, and neuropsychiatric behavior disorders; however, presentation with impulse control disorder is not a frequent presentation. In the current report, a 43-year-old male patient who has been admitted to psychiatry policlinic with the complaints of aggressive behavior episodes and who has been diagnosed with impulse control disorder and IBGC was evaluated in the light of the literature. PMID:26246920

  2. Impaired systolic blood pressure recovery and heart rate recovery after graded exercise in patients with metabolic syndrome.

    Science.gov (United States)

    Alihanoglu, Yusuf I; Yildiz, Bekir S; Kilic, I Dogu; Uludag, Burcu; Demirci, Emre E; Zungur, Mustafa; Evrengul, Harun; Kaftan, Asuman H

    2015-01-01

    The aim of this study was to evaluate and compare systolic blood pressure recovery and heart rate recovery (HRR) values obtained at various time intervals after maximal graded exercise treadmill testing between patients with metabolic syndrome (MS) and the controls without MS. To our knowledge, this is the first study indicating systolic blood pressure recovery (SBPR) impairment and its relations to HRR and other variables in this group of patients. The study population included 110 patients with MS (67 men, 43 women; mean age: 46 ± 9 years) and 110 control subjects who did not meet the criteria for MS (58 men, 52 women; mean age: 44 ± 10 years). All patients were selected from nonobese, apparently healthy sedentary individuals who had the ability to perform maximum exercise testing. SBPR was assessed by calculating the ratio of systolic blood pressure (SBP) obtained in the third minute of the recovery period to either the peak-exercise SBP or the SBP in the first minute of the recovery period after graded exercise testing. HRR values were calculated by subtracting the HR at the first, second, third, fourth, and fifth minutes of the recovery period from the HR reached at peak exercise. There was no significant difference found between the 2 groups with respect to age and sex distribution. As expected, patients with MS had higher waist circumference, fasting plasma glucose and serum triglyceride, and lower high-density lipoprotein cholesterol compared with control subjects. All HRR values calculated in the first, second, third, fourth, and fifth minutes were significantly detected lower in the MS group compared with the control group (HRR 1st: 32 ± 10 vs 36 ± 11; P = 0.009; HRR 2nd: 47 ± 10 vs 51 ± 11; P = 0.02; HRR 3rd: 53 ± 11 vs 58 ± 12; P = 0.001; HRR 4th: 57 ± 11 vs 64 ± 12; P 1 in patients with MS (1.01 ± 0.2 vs 0.91 ± 0.1 and 1.01 ± 0.1 vs 0.94 ± 0.1) and these were statistically significant compared with the control group (P < 0.001 and

  3. Use of the local false discovery rate for identification of metabolic biomarkers in rat urine following Genkwa Flos-induced hepatotoxicity.

    Directory of Open Access Journals (Sweden)

    Zuojing Li

    Full Text Available Metabolomics is concerned with characterizing the large number of metabolites present in a biological system using nuclear magnetic resonance (NMR and HPLC/MS (high-performance liquid chromatography with mass spectrometry. Multivariate analysis is one of the most important tools for metabolic biomarker identification in metabolomic studies. However, analyzing the large-scale data sets acquired during metabolic fingerprinting is a major challenge. As a posterior probability that the features of interest are not affected, the local false discovery rate (LFDR is a good interpretable measure. However, it is rarely used to when interrogating metabolic data to identify biomarkers. In this study, we employed the LFDR method to analyze HPLC/MS data acquired from a metabolomic study of metabolic changes in rat urine during hepatotoxicity induced by Genkwa flos (GF treatment. The LFDR approach was successfully used to identify important rat urine metabolites altered by GF-stimulated hepatotoxicity. Compared with principle component analysis (PCA, LFDR is an interpretable measure and discovers more important metabolites in an HPLC/MS-based metabolomic study.

  4. Phenotypic plasticity of gas exchange pattern and water loss in Scarabaeus spretus (Coleoptera: Scarabaeidae): deconstructing the basis for metabolic rate variation.

    Science.gov (United States)

    Terblanche, John S; Clusella-Trullas, Susana; Chown, Steven L

    2010-09-01

    Investigation of gas exchange patterns and modulation of metabolism provide insight into metabolic control systems and evolution in diverse terrestrial environments. Variation in metabolic rate in response to environmental conditions has been explained largely in the context of two contrasting hypotheses, namely metabolic depression in response to stressful or resource-(e.g. water) limited conditions, or elevation of metabolism at low temperatures to sustain life in extreme conditions. To deconstruct the basis for metabolic rate changes in response to temperature variation, here we undertake a full factorial study investigating the longer- and short-term effects of temperature exposure on gas exchange patterns. We examined responses of traits of gas exchange [standard metabolic rate (SMR); discontinuous gas exchange (DGE) cycle frequency; cuticular, respiratory and total water loss rate (WLR)] to elucidate the magnitude and form of plastic responses in the dung beetle, Scarabaeus spretus. Results showed that short- and longer-term temperature variation generally have significant effects on SMR and WLR. Overall, acclimation to increased temperature led to a decline in SMR (from 0.071+/-0.004 ml CO(2) h(-1) in 15 degrees C-acclimated beetles to 0.039+/-0.004 ml CO(2) h(-1) in 25 degrees C-acclimated beetles measured at 20 degrees C) modulated by reduced DGE frequency (15 degrees C acclimation: 0.554+/-0.027 mHz, 20 degrees C acclimation: 0.257+/-0.030 mHz, 25 degrees C acclimation: 0.208+/-0.027 mHz recorded at 20 degrees C), reduced cuticular WLRs (from 1.058+/-0.537 mg h(-1) in 15 degrees C-acclimated beetles to 0.900+/-0.400 mg h(-1) in 25 degrees C-acclimated beetles measured at 20 degrees C) and reduced total WLR (from 4.2+/-0.5 mg h(-1) in 15 degrees C-acclimated beetles to 3.1+/-0.5 mg h(-1) in 25 degrees C-acclimated beetles measured at 25 degrees C). Respiratory WLR was reduced from 2.25+/-0.40 mg h(-1) in 15 degrees C-acclimated beetles to 1.60+/-0.40 mg h

  5. Tumor Delineation and Quantitative Assessment of Glucose Metabolic Rate within Histologic Subtypes of Non-Small Cell Lung Cancer by Using Dynamic (18)F Fluorodeoxyglucose PET.

    Science.gov (United States)

    Meijer, Tineke W H; de Geus-Oei, Lioe-Fee; Visser, Eric P; Oyen, Wim J G; Looijen-Salamon, Monika G; Visvikis, Dimitris; Verhagen, Ad F T M; Bussink, Johan; Vriens, Dennis

    2016-11-15

    Purpose To assess whether dynamic fluorine 18 ((18)F) fluorodeoxyglucose (FDG) positron emission tomography (PET) has added value over static (18)F-FDG PET for tumor delineation in non-small cell lung cancer (NSCLC) radiation therapy planning by using pathology volumes as the reference standard and to compare pharmacokinetic rate constants of (18)F-FDG metabolism, including regional variation, between NSCLC histologic subtypes. Materials and Methods The study was approved by the institutional review board. Patients gave written informed consent. In this prospective observational study, 1-hour dynamic (18)F-FDG PET/computed tomographic examinations were performed in 35 patients (36 resectable NSCLCs) between 2009 and 2014. Static and parametric images of glucose metabolic rate were obtained to determine lesion volumes by using three delineation strategies. Pathology volume was calculated from three orthogonal dimensions (n = 32). Whole tumor and regional rate constants and blood volume fraction (VB) were computed by using compartment modeling. Results Pathology volumes were larger than PET volumes (median difference, 8.7-25.2 cm(3); Wilcoxon signed rank test, P segmentation on static (18)F-FDG PET images is in best agreement with pathology volume and could be useful for NSCLC autocontouring. Differences in glycolytic rate and VB between SCC and AC are relevant for research in targeting agents and radiation therapy dose escalation. (©) RSNA, 2016 Online supplemental material is available for this article.

  6. The Basal Ganglia and Motor Control

    OpenAIRE

    Groenewegen, Henk J.

    2003-01-01

    This paper briefly reviews the functional anatomy of the basal ganglia and their relationships with the thalamocortical system. The basal ganglia, including the striatum, pallidum, subthalamic nucleus, and substantia nigra, are involved in a number of parallel, functionally segregated cortical-subcortical circuits. These circuits support a wide range of sensorimotor, cognitive and emotional-motivational brain functions. A main role of the basal ganglia is the learning and selection of the mos...

  7. Functional Neuroanatomy of the Basal Ganglia

    OpenAIRE

    Lanciego, José L.; Luquin, Natasha; Obeso, José A.

    2012-01-01

    The “basal ganglia” refers to a group of subcortical nuclei responsible primarily for motor control, as well as other roles such as motor learning, executive functions and behaviors, and emotions. Proposed more than two decades ago, the classical basal ganglia model shows how information flows through the basal ganglia back to the cortex through two pathways with opposing effects for the proper execution of movement. Although much of the model has remained, the model has been modified and amp...

  8. Weight Management, Energy Metabolism, and Endocrine Hor¬mones- Review Article

    Directory of Open Access Journals (Sweden)

    Seyed-Ali MOSTAFAVI

    2015-10-01

    Full Text Available Energy expenditure is determined by basal metabolic rate, physical activity, and Thermic Effect of Foods (TEF. Some endocrine hormones have role in basal metabolism and hence in human energy expenditure. And some foods pose more thermic effects on the total body energy expenditure and therefore can influence body weight. This review was performed to discuss factors which may affect body metabolism and body weight. Latest medical databases and nutrition and metabolism books were reviewed. We used the following keywords in online databases: "Weight Management" and "Hormones"; "Energy Metabolism" and "dietary factors"; "Weight Management" and "dietary factors"; "Endocrine Hormones" and "energy expenditure"; "Basal Energy Expenditure" and "dietary factors"; " Thermic Effect of Foods" and "dietary factors". The best designed articles were used to perform this review. The results are presented bellow. Spicy foods, Caffeine, and alcohol are some dietary factors and Body Size, Body Composition, Age and Gender are the non-dietary factors which may affect the metabolism. Diet composition can also slightly influence the metabolism. This effect depends on how efficient a dietary component is metabolized in the body. Regular dietary pattern also can slightly increase TEF comparing with irregular dietary pattern. Thyroid hormones, Ghrelin, Epinephrine, Cortisol, Steroid hormones, Leptin, Growth hormone, and insulin are among the most important hormones which may influence on metabolism and body weight. Energy expenditure is the basis for measuring human energy requirement and is crucial for weight management. Various hormonal, dietary and non-dietary factors are engaged in total body energy expenditure and are important for weight management. Keywords: Weight Management, Energy Metabolism, Dietary factors, Endocrine Hormones

  9. Effects of p-Synephrine alone and in Combination with Selected Bioflavonoids on Resting Metabolism, Blood Pressure, Heart Rate and Self-Reported Mood Changes

    Directory of Open Access Journals (Sweden)

    Sidney J. Stohs, Harry G Preuss, Samuel C. Keith, Patti L. Keith, Howard Miller, Gilbert R. Kaats

    2011-01-01

    Full Text Available Bitter orange (Citrus aurantium extract is widely used in dietary supplements for weight management and sports performance. Its primary protoalkaloid is p-synephrine. Most studies involving bitter orange extract and p-synephrine have used products with multiple ingredients. The current study assessed the thermogenic effects of p-synephrine alone and in conjunction with the flavonoids naringin and hesperidin in a double-blinded, randomized, placebo-controlled protocol with 10 subjects per treatment group. Resting metabolic rates (RMR, blood pressure, heart rates and a self-reported rating scale were determined at baseline and 75 min after oral ingestion of the test products in V-8 juice. A decrease of 30 kcal occurred in the placebo control relative to baseline. The group receiving p-synephrine (50 mg alone exhibited a 65 kcal increase in RMR as compared to the placebo group. The consumption of 600 mg naringin with 50 mg p-synephrine resulted in a 129 kcal increase in RMR relative to the placebo group. In the group receiving 100 mg hesperidin in addition to the 50 mg p-synephrine plus 600 mg naringin, the RMR increased by 183 kcal, an increase that was statistically significant with respect to the placebo control (p<0.02. However, consuming 1000 mg hesperidin with 50 mg p-synephrine plus 600 mg naringin resulted in a RMR that was only 79 kcal greater than the placebo group. None of the treatment groups exhibited changes in heart rate or blood pressure relative to the control group, nor there were no differences in self-reported ratings of 10 symptoms between the treatment groups and the control group. This unusual finding of a thermogenic combination of ingredients that elevated metabolic rates without corresponding elevations in blood pressure and heart-rates warrants longer term studies to assess its value as a weight control agent.

  10. Piperine’s mitigation of obesity and diabetes can be explained by its up-regulation of the metabolic rate of resting muscle

    Science.gov (United States)

    Naber, Nariman; Pate, Edward; Canton, Marcella; Reggiani, Carlo; Cooke, Roger

    2016-01-01

    We identify a target for treating obesity and type 2 diabetes, the consumption of calories by an increase in the metabolic rate of resting skeletal muscle. The metabolic rate of skeletal muscle can be increased by shifting myosin heads from the super-relaxed state (SRX), with a low ATPase activity, to a disordered relaxed state (DRX), with a higher ATPase activity. The shift of myosin heads was detected by a change in fluorescent intensity of a probe attached to the myosin regulatory light chain in skinned skeletal fibers, allowing us to perform a high-throughput screen of 2,128 compounds. The screen identified one compound, which destabilized the super-relaxed state, piperine (the main alkaloid component of black pepper). Destabilization of the SRX by piperine was confirmed by single-nucleotide turnover measurements. The effect was only observed in fast twitch skeletal fibers and not in slow twitch fibers or cardiac tissues. Piperine increased ATPase activity of skinned relaxed fibers by 66 ± 15%. The Kd was ∼2 µM. Piperine had little effect on the mechanics of either fully active or resting muscle fibers. Previous work has shown that piperine can mitigate both obesity and type 2 diabetes in rodent models of these conditions. We propose that the increase in resting muscle metabolism contributes to these positive effects. The results described here show that up-regulation of resting muscle metabolism could treat obesity and type 2 diabetes and that piperine would provide a useful lead compound for the development of these therapies. PMID:27799519

  11. Elite male Flat jockeys display lower bone density and lower resting metabolic rate than their female counterparts: implications for athlete welfare.

    Science.gov (United States)

    Wilson, George; Hill, Jerry; Sale, Craig; Morton, James P; Close, Graeme L

    2015-12-01

    To test the hypothesis that daily weight-making is more problematic to health in male compared with female jockeys, we compared the bone density and resting metabolic rate (RMR) in weight-matched male and female Flat jockeys. RMR (kcal·kg(-1) lean mass) was lower in males compared with females as well as lower bone-density Z scores at the hip and lumbar spine. Data suggest the lifestyle of male jockeys compromise health more severely than females, possibly because of making weight more frequently.

  12. Early recognition of basal cell naevus syndrome

    NARCIS (Netherlands)

    Veenstra-Knol, HE; Scheewe, JH; van der Vlist, GJ; van Doorn, ME; Ausems, MGEM

    2005-01-01

    The basal cell naevus syndrome is an autosomal dominant syndrome characterised by major manifestations such as basal cell carcinomas, jaw cysts, palmar or plantar pits, and intracranial calcifications. Early recognition is important in order to reduce morbidity due to cutaneous and cerebral malignan

  13. Nevoid Basal Cell Carcinoma Syndrome (Gorlin Syndrome).

    Science.gov (United States)

    Bresler, Scott C; Padwa, Bonnie L; Granter, Scott R

    2016-06-01

    Nevoid basal cell carcinoma syndrome, or basal cell nevus syndrome (Gorlin syndrome), is a rare autosomal dominantly inherited disorder that is characterized by development of basal cell carcinomas from a young age. Other distinguishing clinical features are seen in a majority of patients, and include keratocystic odontogenic tumors (formerly odontogenic keratocysts) as well as dyskeratotic palmar and plantar pitting. A range of skeletal and other developmental abnormalities are also often seen. The disorder is caused by defects in hedgehog signaling which result in constitutive pathway activity and tumor cell proliferation. As sporadic basal cell carcinomas also commonly harbor hedgehog pathway aberrations, therapeutic agents targeting key signaling constituents have been developed and tested against advanced sporadically occurring tumors or syndromic disease, leading in 2013 to FDA approval of the first hedgehog pathway-targeted small molecule, vismodegib. The elucidation of the molecular pathogenesis of nevoid basal cell carcinoma syndrome has resulted in further understanding of the most common human malignancy.

  14. Treatment of metabolic acidosis in patients with stage 3 chronic kidney disease with fruits and vegetables or oral bicarbonate reduces urine angiotensinogen and preserves glomerular filtration rate.

    Science.gov (United States)

    Goraya, Nimrit; Simoni, Jan; Jo, Chan-Hee; Wesson, Donald E

    2014-11-01

    Alkali therapy of metabolic acidosis in patients with chronic kidney disease (CKD) with plasma total CO2 (TCO2) below 22 mmol/l per KDOQI guidelines appears to preserve estimated glomerular filtration rate (eGFR). Since angiotensin II mediates GFR decline in partial nephrectomy models of CKD and even mild metabolic acidosis increases kidney angiotensin II in animals, alkali treatment of CKD-related metabolic acidosis in patients with plasma TCO2 over 22 mmol/l might preserve GFR through reduced kidney angiotensin II. To test this, we randomized 108 patients with stage 3 CKD and plasma TCO2 22-24 mmol/l to Usual Care or interventions designed to reduce dietary acid by 50% using sodium bicarbonate or base-producing fruits and vegetables. All were treated to achieve a systolic blood pressure below 130 mm Hg with regimens including angiotensin converting enzyme inhibition and followed for 3 years. Plasma TCO2 decreased in Usual Care but increased with bicarbonate or fruits and vegetables. By contrast, urine excretion of angiotensinogen, an index of kidney angiotensin II, increased in Usual Care but decreased with bicarbonate or fruits and vegetables. Creatinine-calculated and cystatin C-calculated eGFR decreased in all groups, but loss was less at 3 years with bicarbonate or fruits and vegetables than Usual Care. Thus, dietary alkali treatment of metabolic acidosis in CKD that is less severe than that for which KDOQI recommends therapy reduces kidney angiotensin II activity and preserves eGFR.

  15. Bilateral symmetrical basal ganglia and thalamic lesions in children: an update (2015)

    Energy Technology Data Exchange (ETDEWEB)

    Zuccoli, Giulio [Children' s Hospital of Pittsburgh of UPMC, Section of Neuroradiology, Pittsburgh, PA (United States); Yannes, Michael Paul [University of Pittsburgh School of Medicine, Department of Radiology, Pittsburgh, PA (United States); Nardone, Raffaele [Paracelsus Medical University, Department of Neurology, Christian Doppler Klinik, Salzburg (Austria); Bailey, Ariel [West Virginia University, Department of Radiology, Morgantown, WV (United States); Goldstein, Amy [Children' s Hospital of Pittsburgh of UPMC, Department of Neurology, Section of Metabolic Disorders and Neurogenetics, Pittsburgh, PA (United States)

    2015-10-15

    In children, many inherited or acquired neurological disorders may cause bilateral symmetrical signal intensity alterations in the basal ganglia and thalami. A literature review was aimed at assisting neuroradiologists, neurologists, infectious diseases specialists, and pediatricians to provide further understanding into the clinical and neuroimaging features in pediatric patients presenting with bilateral symmetrical basal ganglia and thalamic lesions on magnetic resonance imaging (MRI). We discuss hypoxic-ischemic, toxic, infectious, immune-mediated, mitochondrial, metabolic, and neurodegenerative disorders affecting the basal ganglia and thalami. Recognition and correct evaluation of basal ganglia abnormalities, together with a proper neurological examination and laboratory findings, may enable the identification of each of these clinical entities and lead to earlier diagnosis. (orig.)

  16. Effects of food ration on SMR: influence of food consumption on individual variation in metabolic rate in juvenile coho salmon (Onchorhynchus kisutch).

    Science.gov (United States)

    Van Leeuwen, Travis E; Rosenfeld, Jordan S; Richards, Jeffrey G

    2012-03-01

    1. Consistency of differences in standard metabolic rate (SMR) between individual juvenile salmonids and the apparently limited ability of individuals to regulate their SMR has led many researchers to conclude that differences in individual SMR are fixed (i.e. genetic). 2. To test for the effects of food ration on individual performance and metabolism, SMR was estimated by measuring oxygen consumption using flow-through respirometry on individually separated young of the year coho salmon (Oncorhynchus kisutch) placed on varying food rations over a period of 44 days. 3. Results demonstrate that the quantity of food consumed directly affects SMR of juvenile coho salmon, independent of specific dynamic action (SDA, an elevation in metabolic rate from the increased energy demands associated with digestion immediately following a meal) and indicates that higher food consumption is a cause of elevated SMR rather than a consequence of it. Juvenile coho salmon therefore demonstrated an ability to regulate their SMR according to food availability and ultimately food consumption. 4. This study indicates that food consumption may play a pivotal role in understanding individual variation in SMR independent of inherent genetic differences. We suggest that studies involving SMR need to be cautious about the effects of intra-individual differences in food consumption in communal tanks or in different microhabitats in the wild as disproportionate food consumption may contribute more to variation in SMR than intrinsic (genetic) factors. 5. In general, our results suggest that evolutionary changes in SMR are likely a response to selection on food consumption and growth, rather than SMR itself.

  17. Basal blood parameters of horses subjected to aerobic activity fed with lipidic concentrated

    Directory of Open Access Journals (Sweden)

    Kátia de Oliveira

    2012-02-01

    Full Text Available The feeding diets were evaluated containing low and high levels of soybean oil for horses athletes subjected to two protocols of aerobic training on the response of basal blood biochemical parameters. Four horses were used in latin square design with treatments in a 2 x 2 factorial arrangement. Treatments consisted levels of 5 and 15% oil concentrates and two aerobic training, 40' and 60' minutes. Plasmatic parameters were monitored, triglyceride (TG, total cholesterol (TC, glucose (GLU and lactate (LAC, during basal metabolism. The TG, TC, GLU and LAC from horses at rest were not affected (P> 0.05 neither of diet and physical activity, 0.21, 3.79, 4.18, 0.93 mmol L-1, respectively. It can be concluded that offer concentrate with high content of soybean oil to athletic horses in aerobic activities can be performed without altering the blood biochemical profile of basal metabolism.

  18. Effects of both ecdysone and the acclimation to low temperature, on growth and metabolic rate of juvenile freshwater crayfish Cherax quadricarinatus (Decapoda, Parastacidae

    Directory of Open Access Journals (Sweden)

    Anouk Chaulet

    2013-06-01

    Full Text Available Growth, metabolic rate, and energy reserves of Cherax quadricarinatus (von Martens, 1868 juveniles were evaluated in crayfish acclimated for 16 weeks to either 25ºC (temperature near optimum or 20ºC (marginal for the species. Additionally, the modulating effect of ecdsyone on acclimation was studied. After 12 weeks of exposure, weight gain of both experimental groups acclimated to 25ºC (control: C25, and ecdysone treated: E25 was significantly higher than that of those groups acclimated to 20ºC (C20 and E20. A total compensation in metabolic rate was seen after acclimation from 25ºC to 20ºC; for both the control group and the group treated with ecdysone. A Q10value significantly higher was only observed in the group acclimated to 20ºC and treated with ecdysone. A reduction of glycogen reserves in both hepatopancreas and muscle, as well as a lower protein content in muscle, was seen in both groups acclimated to 20ºC. Correspondingly, glycemia was always higher in these groups. Increased lipid levels were seen in the hepatopancreas of animals acclimated to 20ºC, while a higher lipid level was also observed in muscle at 20ºC, but only in ecdysone-treated crayfish.

  19. Arginine depletion by arginine deiminase does not affect whole protein metabolism or muscle fractional protein synthesis rate in mice.

    Science.gov (United States)

    Marini, Juan C; Didelija, Inka Cajo

    2015-01-01

    Due to the absolute need for arginine that certain cancer cells have, arginine depletion is a therapy in clinical trials to treat several types of cancers. Arginine is an amino acids utilized not only as a precursor for other important molecules, but also for protein synthesis. Because arginine depletion can potentially exacerbate the progressive loss of body weight, and especially lean body mass, in cancer patients we determined the effect of arginine depletion by pegylated arginine deiminase (ADI-PEG 20) on whole body protein synthesis and fractional protein synthesis rate in multiple tissues of mice. ADI-PEG 20 successfully depleted circulating arginine (arginine, whole body protein synthesis and breakdown were maintained in the ADI-PEG 20 treated mice. The fractional protein synthesis rate of muscle was also not affected by arginine depletion. Most tissues (liver, kidney, spleen, heart, lungs, stomach, small and large intestine, pancreas) were able to maintain their fractional protein synthesis rate; however, the fractional protein synthesis rate of brain, thymus and testicles was reduced due to the ADI-PEG 20 treatment. Furthermore, these results were confirmed by the incorporation of ureido [14C]citrulline, which indicate the local conversion into arginine, into protein. In conclusion, the intracellular recycling pathway of citrulline is able to provide enough arginine to maintain protein synthesis rate and prevent the loss of lean body mass and body weight.

  20. Effects of Temperature on Maximum Metabolic Rate and Metabolic Scope of Juvenile Manchurian Trout, Brachymystax lenok (Pallas)%温度对细鳞鲑幼鱼最大代谢率和代谢范围的影响

    Institute of Scientific and Technical Information of China (English)

    徐革锋; 尹家胜; 韩英; 刘洋; 牟振波

    2014-01-01

    This study examined the effects of water temperature on the metabolic characteristics and aerobic exer-cise capacity of juvenile manchurian trout , Brachymystax lenok ( Pallas) .The resting metabolic rate ( RMR) ,maxi-mum metabolic rate (MMR), metabolic scope(MS)and critical swimming speed (UCrit) of juveniles were measured at different temperature (4, 8, 12, 16, 20℃).The results showed that both the RMR and the MMR increased sig-nificantly with the increasing of water temperature ( P<0 .05 ) .Compared with test group at 4℃, the RMR for 8℃, 12℃, 16℃ and 20℃increased by 62%, 165%, 390%, 411%,respectively, and the MMR increased by 3%, 34%, 111%, 115%, respectively .However , the MS decreased with the increasing of water temperature with the highest MS occurring at 4℃.UCrit was significantly affected by water temperature (P<0.05), but the varia-tions of UCrit didn′t follow certain pattern with temperature .In the test of aerobic exercise , the MMR for each tem-perature level occurred at the swimming speed of 70% UCrit , probably due to the start of anaerobic metabolism , which caused excessive creatine in body , consequently hindered the aerobic metabolism .%为了探究温度对细鳞鲑( Brachymystax lenok)幼鱼的代谢特征和有氧运动能力的影响,在不同温度(4℃、8℃、12℃、16℃、20℃)下测定了实验鱼的静止代谢率( RMR)、有氧运动过程中的最大代谢率( MMR)以及能量代谢范围(MS)和临界游泳速度(UCrit)。结果表明,随着温度的上升,RMR和MMR均显著提高(P<0.05),各温度下的RMR和MMR分别较4℃条件的提高了62%(8℃)、165%(12℃)、390%(16℃)、411%(20℃)和3%(8℃)、34%(12℃)、111%(16℃)、115%(20℃);MS随水温的升高呈现下降的趋势,且4℃条件具有最大的代谢范围。不同温度条件下UCrit存在显著性差异,但随着温度升高未表现出明显的变

  1. A Single Arm Pilot Study of Effects of Berberine on the Menstrual Pattern, Ovulation Rate, Hormonal and Metabolic Profiles in Anovulatory Chinese Women with Polycystic Ovary Syndrome.

    Directory of Open Access Journals (Sweden)

    Lin Li

    Full Text Available To evaluate the effects of berberine on the menstrual pattern, ovulation rate, hormonal and metabolic profiles in anovulatory Chinese women with polycystic ovary syndrome.Berberine 0.4 g three times per day was given for four months to 102 anovulatory Chinese women with polycystic ovary syndrome. The menstrual pattern, ovulation rate, hormonal and metabolic profiles were compared before and after the berberine treatment. Ovulation was confirmed by serum progesterone level ≥10 ng/ml.A total of 98 of 102 subjects (96.1% completed the four month treatment, including 69 (70.4%, 69/98 normal weight and 29 (29.6%, 29/98 overweight/obese. Fourteen women (14.3%, 14/98 had regained regular menses after berberine treatment and there was no significant difference between normal weight and overweight/obese groups. The ovulation rate was 25.0% over four months in the whole group, 22.5% in the normal weight group and 31.0% in the overweight/obese group. Sex hormone binding globulin, insulin resistance, total cholesterol, total triglyceride and low-density lipoprotein cholesterol decreased after berberine treatment in the normal weight group only.Our study found that administration of berberine alone may improve the menstrual pattern and ovulation rate in anovulatory Chinese women with polycystic ovary syndrome. Berberine can also decrease sex hormone binding globulin, insulin resistance, total cholesterol, triglycerides and low-density lipoprotein cholesterol in normal weight polycystic ovary syndrome women.Chictr.org ChiCTR-OO-13003943.

  2. Idiorrhythmic dose-rate variability in dietary zinc intake generates a different response pattern of zinc metabolism than conventional dose-response feeding.

    Science.gov (United States)

    Momcilović, B; Reeves, P G; Blake, M J

    1997-07-01

    We compared the effects of idiorrhythmic dose-rate feeding and conventional dose-response on the induction of intestinal metallothionein (iMT), expression of aortal heat-shock protein mRNA (HSP70mRNA) induced by restraint stress, and accumulation of Zn in the femur and incisor of young growing male rats. An idiorrhythmic approach requires that the average dietary Zn concentration (modulo, M) over the whole experiment (epoch, E) is kept constant across different groups. This is done by adjusting the Zn concentration of the supplemented diet supplied to compensate for the reduction in the number of days on which Zn-supplemented diet is fed, the latter being spread evenly over the experiment. Idiorrhythms involve offering the diet with n times the overall Zn concentration (M) only every nth day with Zn-deficient diet offered on other days. Idiorrythmic Zn dose-rate feeding changed Zn accumulation in the femur and incisor in a complex bi-modal fashion, indicating that metabolic efficiency of dietary Zn is not constant but depends on Zn dose-rate. In contrast to feeding Zn in the conventional dose-response scheme, iMT and HSP70mRNA were not affected by idiorrhythmic dose-rate feeding. Idiorrhythmic cycling in dietary Zn load posed no risk of a biochemical overload nor caused the animals to be stressed. Idiorrhythmic dose-rate feeding brings the dimension of time to the conventional dose-response model.

  3. Basal physiological parameters in domesticated tree shrews (Tupaia belangeri chinensis).

    Science.gov (United States)

    Wang, Jing; Xu, Xin-Li; Ding, Ze-Yang; Mao, Rong-Rong; Zhou, Qi-Xin; Lü, Long-Bao; Wang, Li-Ping; Wang, Shuang; Zhang, Chen; Xu, Lin; Yang, Yue-Xiong

    2013-04-01

    Establishing non-human primate models of human diseases is an efficient way to narrow the large gap between basic studies and translational medicine. Multifold advantages such as simplicity of breeding, low cost of feeding and facility of operating make the tree shrew an ideal non-human primate model proxy. Additional features like vulnerability to stress and spontaneous diabetic characteristics also indicate that the tree shrew could be a potential new animal model of human diseases. However, basal physiological indexes of tree shrew, especially those related to human disease, have not been systematically reported. Accordingly, we established important basal physiological indexes of domesticated tree shrews including several factors: (1) body weight, (2) core body temperature and rhythm, (3) diet metabolism, (4) locomotor rhythm, (5) electroencephalogram, (6) glycometabolism and (7) serum and urinary hormone level and urinary cortisol rhythm. We compared the physiological parameters of domesticated tree shrew with that of rats and macaques. Results showed that (a) the core body temperature of the tree shrew was 39.59±0.05 ℃, which was higher than that of rats and macaques; (b) Compared with wild tree shrews, with two activity peaks, domesticated tree shrews had only one activity peak from 17:30 to 19:30; (c) Compared with rats, tree shrews had poor carbohydrate metabolism ability; and (d) Urinary cortisol rhythm indicated there were two peaks at 8:00 and 17:00 in domesticated tree shrews, which matched activity peaks in wild tree shrews. These results provided basal physiological indexes for domesticated tree shrews and laid an important foundation for diabetes and stress-related disease models established on tree shrews.

  4. Metastatic Basal Cell Carcinoma Accompanying Gorlin Syndrome

    Directory of Open Access Journals (Sweden)

    Yeliz Bilir

    2014-01-01

    Full Text Available Gorlin-Goltz syndrome or basal cell nevus syndrome is an autosomal dominant syndrome characterized by skeletal anomalies, numerous cysts observed in the jaw, and multiple basal cell carcinoma of the skin, which may be accompanied by falx cerebri calcification. Basal cell carcinoma is the most commonly skin tumor with slow clinical course and low metastatic potential. Its concomitance with Gorlin syndrome, resulting from a mutation in a tumor suppressor gene, may substantially change morbidity and mortality. A 66-year-old male patient with a history of recurrent basal cell carcinoma was presented with exophthalmus in the left eye and the lesions localized in the left lateral orbita and left zygomatic area. His physical examination revealed hearing loss, gapped teeth, highly arched palate, and frontal prominence. Left orbital mass, cystic masses at frontal and ethmoidal sinuses, and multiple pulmonary nodules were detected at CT scans. Basal cell carcinoma was diagnosed from biopsy of ethmoid sinus. Based on the clinical and typical radiological characteristics (falx cerebri calcification, bifid costa, and odontogenic cysts, the patient was diagnosed with metastatic skin basal cell carcinoma accompanied by Gorlin syndrome. Our case is a basal cell carcinoma with aggressive course accompanying a rarely seen syndrome.

  5. Metastatic Basal cell carcinoma accompanying gorlin syndrome.

    Science.gov (United States)

    Bilir, Yeliz; Gokce, Erkan; Ozturk, Banu; Deresoy, Faik Alev; Yuksekkaya, Ruken; Yaman, Emel

    2014-01-01

    Gorlin-Goltz syndrome or basal cell nevus syndrome is an autosomal dominant syndrome characterized by skeletal anomalies, numerous cysts observed in the jaw, and multiple basal cell carcinoma of the skin, which may be accompanied by falx cerebri calcification. Basal cell carcinoma is the most commonly skin tumor with slow clinical course and low metastatic potential. Its concomitance with Gorlin syndrome, resulting from a mutation in a tumor suppressor gene, may substantially change morbidity and mortality. A 66-year-old male patient with a history of recurrent basal cell carcinoma was presented with exophthalmus in the left eye and the lesions localized in the left lateral orbita and left zygomatic area. His physical examination revealed hearing loss, gapped teeth, highly arched palate, and frontal prominence. Left orbital mass, cystic masses at frontal and ethmoidal sinuses, and multiple pulmonary nodules were detected at CT scans. Basal cell carcinoma was diagnosed from biopsy of ethmoid sinus. Based on the clinical and typical radiological characteristics (falx cerebri calcification, bifid costa, and odontogenic cysts), the patient was diagnosed with metastatic skin basal cell carcinoma accompanied by Gorlin syndrome. Our case is a basal cell carcinoma with aggressive course accompanying a rarely seen syndrome.

  6. 运动锻炼对鲤鱼幼鱼游泳能力及代谢的影响%The Effect of Exercise Training on the Swimming Performance and Metabolic Rate in Juvenile Common Carp (Cyprinus carpio)

    Institute of Scientific and Technical Information of China (English)

    闫东娟; 闫冠杰; 曹振东; 付世建

    2012-01-01

    以鲤鱼(Cyprinus carpio)幼鱼为研究对象,在25℃条件下将90尾体重为(8.12±1.30)g的实验鱼平均分成0h锻炼组(对照组)、6h锻炼组和12h锻炼组,以600临界游泳速度(Ucrit)持续运动锻炼15d,每天锻炼时间分别为0、6和12 h;随后对实验鱼进行Ucrit、耗氧率(MO2)和快速启动(Fast- start)的测定.结果显示,经过运动锻炼鲤鱼幼鱼的Ucrit和Fast-start与对照组相比,均没有显著提高,但6h锻炼组的实验鱼在30和36 cm·s-1的流速下MO2显著降低,而12h运动锻炼组的MO2始终处于较高水平.研究认为可能是由于在低于Ucrit流速下的适度的运动锻炼可能会提高鱼类在该流速下的能量利用效率,而高强度的锻炼则会使它们的基础代谢处于较高水平.%To investigate the effect of exercise training on the swimming performance and metabolic rate during swimming in juvenile common carp (Cyprinus carpio). 90 juvenile fish (8. 12+1. 30) g was forced to swim under 60% critical swimming speed (Ucrit) for 0 h (control), 6 h and 12 h daily for 15 d. Then three groups of fish were underwent both an Ucrit, and fast-start measurement. The oxygen consumption rate (Mo2 ) at different swimming speed was also measured. Neither Ucrit, nor fast-start performance as indicated by maximum velocity (Vmax), maximum acceleration velocity (Amax) and travel distance during first 12 ms (S120 ms) significantly changed after 15 d training in juvenile common carp. However, the Mo2 at 20 and 36 cm s ' of fish in 6 h training group were significantly lower than those in control group while the Mo, at all swimming speed of fish in 12 h training group were significantly higher than those of control group (p<0. 05). It suggested that the cost of transport decrease after moderate exercise training (6 h), however, high intensity training (12 h) may impair the cost of transport by increased basal metabolic rate.

  7. Prosthetic ankle push-off work reduces metabolic rate but not collision work in non-amputee walking

    Science.gov (United States)

    Caputo, Joshua M.; Collins, Steven H.

    2014-12-01

    Individuals with unilateral below-knee amputation expend more energy than non-amputees during walking and exhibit reduced push-off work and increased hip work in the affected limb. Simple dynamic models of walking suggest a possible solution, predicting that increasing prosthetic ankle push-off should decrease leading limb collision, thereby reducing overall energy requirements. We conducted a rigorous experimental test of this idea wherein ankle-foot prosthesis push-off work was incrementally varied in isolation from one-half to two-times normal levels while subjects with simulated amputation walked on a treadmill at 1.25 m.s-1. Increased prosthesis push-off significantly reduced metabolic energy expenditure, with a 14% reduction at maximum prosthesis work. In contrast to model predictions, however, collision losses were unchanged, while hip work during swing initiation was decreased. This suggests that powered ankle push-off reduces walking effort primarily through other mechanisms, such as assisting leg swing, which would be better understood using more complete neuromuscular models.

  8. How Basal Ganglia Outputs Generate Behavior

    Directory of Open Access Journals (Sweden)

    Henry H. Yin

    2014-01-01

    Full Text Available The basal ganglia (BG are a collection of subcortical nuclei critical for voluntary behavior. According to the standard model, the output projections from the BG tonically inhibit downstream motor centers and prevent behavior. A pause in the BG output opens the gate for behavior, allowing the initiation of actions. Hypokinetic neurological symptoms, such as inability to initiate actions in Parkinson’s disease, are explained by excessively high firing rates of the BG output neurons. This model, widely taught in textbooks, is contradicted by recent electrophysiological results, which are reviewed here. In addition, I also introduce a new model, based on the insight that behavior is a product of closed loop negative feedback control using internal reference signals rather than sensorimotor transformations. The nervous system is shown to be a functional hierarchy comprising independent controllers occupying different levels, each level controlling specific variables derived from its perceptual inputs. The BG represent the level of transition control in this hierarchy, sending reference signals specifying the succession of body orientations and configurations. This new model not only explains the major symptoms in movement disorders but also generates a number of testable predictions.

  9. Arginine depletion by arginine deiminase does not affect whole protein metabolism or muscle fractional protein synthesis rate in mice.

    Directory of Open Access Journals (Sweden)

    Juan C Marini

    Full Text Available Due to the absolute need for arginine that certain cancer cells have, arginine depletion is a therapy in clinical trials to treat several types of cancers. Arginine is an amino acids utilized not only as a precursor for other important molecules, but also for protein synthesis. Because arginine depletion can potentially exacerbate the progressive loss of body weight, and especially lean body mass, in cancer patients we determined the effect of arginine depletion by pegylated arginine deiminase (ADI-PEG 20 on whole body protein synthesis and fractional protein synthesis rate in multiple tissues of mice. ADI-PEG 20 successfully depleted circulating arginine (<1 μmol/L, and increased citrulline concentration more than tenfold. Body weight and body composition, however, were not affected by ADI-PEG 20. Despite the depletion of arginine, whole body protein synthesis and breakdown were maintained in the ADI-PEG 20 treated mice. The fractional protein synthesis rate of muscle was also not affected by arginine depletion. Most tissues (liver, kidney, spleen, heart, lungs, stomach, small and large intestine, pancreas were able to maintain their fractional protein synthesis rate; however, the fractional protein synthesis rate of brain, thymus and testicles was reduced due to the ADI-PEG 20 treatment. Furthermore, these results were confirmed by the incorporation of ureido [14C]citrulline, which indicate the local conversion into arginine, into protein. In conclusion, the intracellular recycling pathway of citrulline is able to provide enough arginine to maintain protein synthesis rate and prevent the loss of lean body mass and body weight.

  10. Neglected giant scalp Basal cell carcinoma

    DEFF Research Database (Denmark)

    Larsen, Anne Kristine; El-Charnoubi, Waseem-Asim Ghulam; Gehl, Julie;

    2014-01-01

    SUMMARY: Rarely, basal cell carcinoma grows to a giant size, invading the underlying deep tissue and complicating the treatment and reconstruction modalities. A giant basal cell carcinoma on the scalp is in some cases treated with a combination of surgery and radiation therapy, resulting in local...... control, a satisfactory long-term cosmetic and functional result. We present a case with a neglected basal cell scalp carcinoma, treated with wide excision and postoperative radiotherapy, reconstructed with a free latissimus dorsi flap. The cosmetic result is acceptable and there is no sign of recurrence...

  11. Neglected Giant Scalp Basal Cell Carcinoma

    Directory of Open Access Journals (Sweden)

    Anne Kristine Larsen, MD

    2014-03-01

    Full Text Available Summary: Rarely, basal cell carcinoma grows to a giant size, invading the underlying deep tissue and complicating the treatment and reconstruction modalities. A giant basal cell carcinoma on the scalp is in some cases treated with a combination of surgery and radiation therapy, resulting in local control, a satisfactory long-term cosmetic and functional result. We present a case with a neglected basal cell scalp carcinoma, treated with wide excision and postoperative radiotherapy, reconstructed with a free latissimus dorsi flap. The cosmetic result is acceptable and there is no sign of recurrence 1 year postoperatively.

  12. Ethanol and reactive species increase basal sequence heterogeneity of hepatitis C virus and produce variants with reduced susceptibility to antivirals.

    Science.gov (United States)

    Seronello, Scott; Montanez, Jessica; Presleigh, Kristen; Barlow, Miriam; Park, Seung Bum; Choi, Jinah

    2011-01-01

    Hepatitis C virus (HCV) exhibits a high level of genetic variability, and variants with reduced susceptibility to antivirals can occur even before treatment begins. In addition, alcohol decreases efficacy of antiviral therapy and increases sequence heterogeneity of HCV RNA but how ethanol affects HCV sequence is unknown. Ethanol metabolism and HCV infection increase the level of reactive species that can alter cell metabolism, modify signaling, and potentially act as mutagen to the viral RNA. Therefore, we investigated whether ethanol and reactive species affected the basal sequence variability of HCV RNA in hepatocytes. Human hepatoma cells supporting a continuous replication of genotype 1b HCV RNA (Con1, AJ242652) were exposed to ethanol, acetaldehyde, hydrogen peroxide, or L-buthionine-S,R-sulfoximine (BSO) that decreases intracellular glutathione as seen in patients. Then, NS5A region was sequenced and compared with genotype 1b HCV sequences in the database. Ethanol and BSO elevated nucleotide and amino acid substitution rates of HCV RNA by 4-18 folds within 48 hrs which were accompanied by oxidative RNA damage. Iron chelator and glutathione ester decreased both RNA damage and mutation rates. Furthermore, infectious HCV and HCV core gene were sufficient to induce oxidative RNA damage even in the absence of ethanol or BSO. Interestingly, the dn/ds ratio and percentage of sites undergoing positive selection increased with ethanol and BSO, resulting in an increased detection of NS5A variants with reduced susceptibility to interferon alpha, cyclosporine, and ribavirin and others implicated in immune tolerance and modulation of viral replication. Therefore, alcohol is likely to synergize with virus-induced oxidative/nitrosative stress to modulate the basal mutation rate of HCV. Positive selection induced by alcohol and reactive species may contribute to antiviral resistance.

  13. Apico-basal polarity complex and cancer

    Indian Academy of Sciences (India)

    Mohammed Khursheed; Murali Dharan Bashyam

    2014-03-01

    Apico-basal polarity is a cardinal molecular feature of adult eukaryotic epithelial cells and appears to be involved in several key cellular processes including polarized cell migration and maintenance of tissue architecture. Epithelial cell polarity is maintained by three well-conserved polarity complexes, namely, PAR, Crumbs and SCRIB. The location and interaction between the components of these complexes defines distinct structural domains of epithelial cells. Establishment and maintenance of apico-basal polarity is regulated through various conserved cell signalling pathways including TGF, Integrin and WNT signalling. Loss of cell polarity is a hallmark for carcinoma, and its underlying molecular mechanism is beginning to emerge from studies on model organisms and cancer cell lines. Moreover, deregulated expression of apico-basal polarity complex components has been reported in human tumours. In this review, we provide an overview of the apico-basal polarity complexes and their regulation, their role in cell migration, and finally their involvement in carcinogenesis.

  14. Automatic basal slice detection for cardiac analysis

    Science.gov (United States)

    Paknezhad, Mahsa; Marchesseau, Stephanie; Brown, Michael S.

    2016-03-01

    Identification of the basal slice in cardiac imaging is a key step to measuring the ejection fraction (EF) of the left ventricle (LV). Despite research on cardiac segmentation, basal slice identification is routinely performed manually. Manual identification, however, has been shown to have high inter-observer variability, with a variation of the EF by up to 8%. Therefore, an automatic way of identifying the basal slice is still required. Prior published methods operate by automatically tracking the mitral valve points from the long-axis view of the LV. These approaches assumed that the basal slice is the first short-axis slice below the mitral valve. However, guidelines published in 2013 by the society for cardiovascular magnetic resonance indicate that the basal slice is the uppermost short-axis slice with more than 50% myocardium surrounding the blood cavity. Consequently, these existing methods are at times identifying the incorrect short-axis slice. Correct identification of the basal slice under these guidelines is challenging due to the poor image quality and blood movement during image acquisition. This paper proposes an automatic tool that focuses on the two-chamber slice to find the basal slice. To this end, an active shape model is trained to automatically segment the two-chamber view for 51 samples using the leave-one-out strategy. The basal slice was detected using temporal binary profiles created for each short-axis slice from the segmented two-chamber slice. From the 51 successfully tested samples, 92% and 84% of detection results were accurate at the end-systolic and the end-diastolic phases of the cardiac cycle, respectively.

  15. Biomarkers for Basal-like Breast Cancer

    OpenAIRE

    Choo, Jennifer R.; Torsten O. Nielsen

    2010-01-01

    Initially recognized through microarray-based gene expression profiling, basal-like breast cancer, for which we lack effective targeted therapies, is an aggressive form of carcinoma with a predilection for younger women. With some success, immunohistochemical studies have attempted to reproduce the expression profile classification of breast cancer through identification of subtype-specific biomarkers. This review aims to present an in depth summary and analysis of the current status of basal...

  16. Effects of diet composition on the metabolic and heart rate responses to cold water exposure in men.

    Science.gov (United States)

    Ashkar, E; Marsiglia, J C; Berreta, J A; Garcia, S A; Rodríguez, R R; Estol, C J

    1985-01-01

    The reaction to immersion in cold water (22 degrees C) was studied in ten healthy male volunteers successively receiving balanced (C), hypercarbohydrate (HC), hyperprotein (HP), and hyperlipid (HL) normocaloric diets with a three week equilibration period on each diet. Oxygen consumption (ml min-1 m-2) increased from 149 to 224 during C, from 160 to 196 during HL, from 154 to 178 during HP, and from 166 to 187 during HL. Only the first two differences were significant. Pulmonary ventilation (ml min-1 m-2) increased from 4.08 to 6.24 during C, from 4.01 to 5.48 during HC, from 3.41 to 3.83 during HP, and from 3.77 to 5.48 during HL. The difference was statistically significant only for C. Heart rate (beats/min) decreased from 73 to 64 during C, from 74 to 61 during HC, from 73 to 60 during HP and from 72 to 64 during HL. The differences were statistically significant for all diets except HL. Oral temperature decreased in all groups (range 0.4 to 1.6 degrees C). Respiratory rate changes were not statistically significant. The calorigenic reaction to cold water immersion was demonstrable for all groups but more efficient in subjects receiving either balanced or HC diets, suggesting that HP and HL diets reduce cold adaptation.

  17. Temperature Shift Experiments Suggest That Metabolic Impairment and Enhanced Rates of Photorespiration Decrease Organic Acid Levels in Soybean Leaflets Exposed to Supra-Optimal Growth Temperatures

    Directory of Open Access Journals (Sweden)

    Richard C. Sicher

    2015-08-01

    Full Text Available Elevated growth temperatures are known to affect foliar organic acid concentrations in various plant species. In the current study, citrate, malate, malonate, fumarate and succinate decreased 40 to 80% in soybean leaflets when plants were grown continuously in controlled environment chambers at 36/28 compared to 28/20 °C. Temperature effects on the above mentioned organic acids were partially reversed three days after plants were transferred among optimal and supra-optimal growth temperatures. In addition, CO2 enrichment increased foliar malate, malonate and fumarate concentrations in the supra-optimal temperature treatment, thereby mitigating effects of high temperature on respiratory metabolism. Glycerate, which functions in the photorespiratory pathway, decreased in response to CO2 enrichment at both growth temperatures. The above findings suggested that diminished levels of organic acids in soybean leaflets upon exposure to high growth temperatures were attributable to metabolic impairment and to changes of photorespiratory flux. Leaf development rates differed among temperature and CO2 treatments, which affected foliar organic acid levels. Additionally, we report that large decreases of foliar organic acids in response to elevated growth temperatures were observed in legume species.

  18. Temperature Shift Experiments Suggest That Metabolic Impairment and Enhanced Rates of Photorespiration Decrease Organic Acid Levels in Soybean Leaflets Exposed to Supra-Optimal Growth Temperatures.

    Science.gov (United States)

    Sicher, Richard C

    2015-08-05

    Elevated growth temperatures are known to affect foliar organic acid concentrations in various plant species. In the current study, citrate, malate, malonate, fumarate and succinate decreased 40 to 80% in soybean leaflets when plants were grown continuously in controlled environment chambers at 36/28 compared to 28/20 °C. Temperature effects on the above mentioned organic acids were partially reversed three days after plants were transferred among optimal and supra-optimal growth temperatures. In addition, CO2 enrichment increased foliar malate, malonate and fumarate concentrations in the supra-optimal temperature treatment, thereby mitigating effects of high temperature on respiratory metabolism. Glycerate, which functions in the photorespiratory pathway, decreased in response to CO2 enrichment at both growth temperatures. The above findings suggested that diminished levels of organic acids in soybean leaflets upon exposure to high growth temperatures were attributable to metabolic impairment and to changes of photorespiratory flux. Leaf development rates differed among temperature and CO2 treatments, which affected foliar organic acid levels. Additionally, we report that large decreases of foliar organic acids in response to elevated growth temperatures were observed in legume species.

  19. Modeling metabolic networks in C. glutamicum: a comparison of rate laws in combination with various parameter optimization strategies

    Directory of Open Access Journals (Sweden)

    Oldiges Marco

    2009-01-01

    Full Text Available Abstract Background To understand the dynamic behavior of cellular systems, mathematical modeling is often necessary and comprises three steps: (1 experimental measurement of participating molecules, (2 assignment of rate laws to each reaction, and (3 parameter calibration with respect to the measurements. In each of these steps the modeler is confronted with a plethora of alternative approaches, e. g., the selection of approximative rate laws in step two as specific equations are often unknown, or the choice of an estimation procedure with its specific settings in step three. This overall process with its numerous choices and the mutual influence between them makes it hard to single out the best modeling approach for a given problem. Results We investigate the modeling process using multiple kinetic equations together with various parameter optimization methods for a well-characterized example network, the biosynthesis of valine and leucine in C. glutamicum. For this purpose, we derive seven dynamic models based on generalized mass action, Michaelis-Menten and convenience kinetics as well as the stochastic Langevin equation. In addition, we introduce two modeling approaches for feedback inhibition to the mass action kinetics. The parameters of each model are estimated using eight optimization strategies. To determine the most promising modeling approaches together with the best optimization algorithms, we carry out a two-step benchmark: (1 coarse-grained comparison of the algorithms on all models and (2 fine-grained tuning of the best optimization algorithms and models. To analyze the space of the best parameters found for each model, we apply clustering, variance, and correlation analysis. Conclusion A mixed model based on the convenience rate law and the Michaelis-Menten equation, in which all reactions are assumed to be reversible, is the most suitable deterministic modeling approach followed by a reversible generalized mass action kinetics

  20. Metabolism of Nonessential N15-Labeled Amino Acids and the Measurement of Human Whole-Body Protein Synthesis Rates

    Science.gov (United States)

    Stein, T. P.; Settle, R. G.; Albina, J. A.; Dempsey, D. T.; Melnick, G.

    1991-01-01

    Eight N-15 labeled nonessential amino acids plus (15)NH4Cl were administered over a 10 h period to four healthy adult males using a primed-constant dosage regimen. The amount of N-15 excreted in the urine and the urinary ammonia, hippuric acid, and plasma alanine N-15 enrichments were measured. There was a high degree of consistency across subjects in the ordering of the nine compounds based on the fraction of N-15 excreted (Kendall coefficient of concordance W = 0.83, P is less than 0.01). Protein synthesis rates were calculated from the urinary ammonia plateau enrichment and the cumulative excretion of N-15. Glycine was one of the few amino acids that gave similar values by both methods.

  1. Heart rate and metabolic responses to moderate-intensity aerobic exercise: a comparison of graded walking and ungraded jogging at a constant perceived exertion.

    Science.gov (United States)

    Kilpatrick, Marcus W; Kraemer, Robert R; Quigley, Edward J; Mears, Jennifer L; Powers, Jeremy M; Dedea, Anthony J; Ferrer, Nicholas F

    2009-03-01

    In this study, we assessed how ungraded jogging and graded walking at the same rating of perceived exertion (RPE) affect heart rate and oxygen consumption ([Vdot]O(2)). Twenty untrained participants completed a treadmill test to determine peak [Vdot]O(2) (mean = 40.3 +/- 6.3 ml . kg(-1) . min(-1)). Participants completed separate 30-min trials of moderate exercise (RPE of 13 on the Borg 6-20 scale) in random order on the treadmill: graded walking and ungraded jogging. Treadmill speed or grade was adjusted throughout the trial by the experimenter based on participant responses to maintain an RPE of 13. The jogging trial produced a significantly higher heart rate (161 +/- 18 vs. 142 +/- 24 beats . min(-1)) and [Vdot]O(2) (7.4 +/- 1.8 vs. 5.8 +/- 1.5 METs) (P jogging trial (5.2 +/- 1.0 miles . h(-1) to 5.0 +/- 0.9 miles . h(-1)) (P > 0.05), in an effort to maintain constant RPE. These findings provide evidence that similar perceptions of effort during graded walking and ungraded jogging do not produce similar cardiovascular and metabolic responses. The results indicate that, for a given prescribed perceived effort, jogging provides a greater stimulus for fitness benefits and caloric expenditure.

  2. Dietary Caffeine and Polyphenol Supplementation Enhances Overall Metabolic Rate and Lipid Oxidation at Rest and After a Bout of Sprint Interval Exercise.

    Science.gov (United States)

    Jo, Edward; Lewis, Kiana L; Higuera, Daniel; Hernandez, Joshua; Osmond, Adam D; Directo, Dean J; Wong, Michael

    2016-07-01

    Jo, E, Lewis, KL, Higuera, D, Hernandez, J, Osmond, AD, Directo, DJ, and Wong, M. Dietary caffeine and polyphenol supplementation enhances overall metabolic rate and lipid oxidation at rest and after a bout of sprint interval exercise. J Strength Cond Res 30(7): 1871-1879, 2016-The purpose of this study was to investigate the effects of a caffeine-polyphenolic supplement on (a) metabolic rate and fat oxidation at rest and after a bout of sprint interval exercise (SIE) and (b) SIE performance. In a double-blind, randomized, placebo-controlled, crossover study and after an initial familiarization visit, 12 subjects (male: n = 11; female: n = 1) (body mass = 76.1 ± 2.2 kg; height = 169.8 ± 1.6 cm; body mass index = 22.7 ± 3.0 kg·m; body fat % = 21.6 ± 2.0%) underwent 2 testing sessions during which time they consumed either a caffeine-polyphenol supplement or placebo. After supplementation, resting energy expenditure, heart rate (HR), and blood pressure (BP) were assessed. Subsequently, subjects performed 30 minutes of SIE while researchers collected performance data. Subjects were then tested for post-SIE energy expenditure, HR, and BP. The caffeine-polyphenol treatment resulted in significantly (p ≤ 0.05) greater energy expenditure (+7.99% rest; +10.16% post-SIE), V[Combining Dot Above]O2 (+9.64% rest; +12.10% post-SIE), and fat oxidation rate (+10.60% rest; +9.76% post-SIE) vs. placebo at rest and post-SIE. No significant differences were detected for peak and average power at all sprint intervals between treatments. Post-SIE HR was significantly (p ≤ 0.05) greater with caffeine-polyphenol supplementation vs. placebo (90.8 ± 3.5 vs. 85.1 ± 3.6 b·min). There were no significant between-treatment differences for BP. It may be concluded that the observed thermogenic response after SIE was directly attributable to caffeine-polyphenol supplementation as opposed to an indirect manifestation of enhanced performance and work output. Collectively, these results

  3. Localized basal meningeal enhancement in tuberculous meningitis

    Energy Technology Data Exchange (ETDEWEB)

    Theron, Salomine; Andronikou, Savvas; Grobbelaar, Marie; Steyn, Freda; Mapukata, Ayanda; Plessis, Jaco du [University of Stellenbosch, Department of Radiology, Tygerberg Hospital, P.O. BOX 19063, Tygerberg (South Africa)

    2006-11-15

    Focal basal meningeal enhancement may produce a confusing CT picture in children with suspected tuberculous meningitis (TBM). To demonstrate the incidence, distribution and appearance of localized basal meningeal enhancement in children with TBM. CT scans of patients with definite (culture proven) and probable (CSF suggestive) TBM were retrospectively evaluated by two observers. Localized basal enhancement was documented as involving: unilateral cistern of the lateral fossa (CLF), unilateral sylvian fissure, unilateral CLF and sylvian fissure in combination, unilateral CLF and sylvian fissure with ipsi- or contralateral ambient cistern and isolated quadrigeminal plate cistern. The study included 130 patients with TBM (aged 2 months to 13 years 9 months). Focal basal enhancement was seen in 11 patients (8.5%). The sylvian fissure was involved most commonly, followed by the lateral fossa cistern. The ambient cistern was involved in three patients and the quadrigeminal plate cistern in one. Focal areas of enhancement corresponded to the areas of infarction in every patient. Focal basal meningeal enhancement is common (8.5%) in paediatric TBM. This must be kept in mind when evaluating CT scans in children presenting with focal neurological findings, seizures or meningism in communities where TBM is endemic. (orig.)

  4. Somatotopic organization of the primate basal ganglia

    Directory of Open Access Journals (Sweden)

    Atsushi eNambu

    2011-04-01

    Full Text Available Somatotopic organization is a fundamental and key concept to understand how the cortico-basal ganglia loop works. It is also indispensable knowledge to perform stereotaxic surgery for movement disorders. Here I would like to describe the somatotopic organization of the basal ganglia, which consist of the striatum, subthalamic nucleus, globus pallidus and substantia nigra. Projections from motor cortical regions representing different body parts terminate in different regions of these nuclei. Basal ganglia neurons respond not only to the stimulation of the corresponding regions of the motor cortices, but also to active and passive movements of the corresponding body parts. On the basis of these anatomical and physiological findings, somatotopic organization can be identified in the motor territories of these nuclei in the basal ganglia. In addition, projections from functionally interrelated cortical areas partially converge through the cortico-basal ganglia loop, but nevertheless the somatotopy is still preserved. Disorganized somatotopy may explain, at least in part, the pathophysiology of movement disorders, such as Parkinson’s disease and dystonia.

  5. Selected regulation of gastrointestinal acid-base secretion and tissue metabolism for the diamondback water snake and Burmese python.

    Science.gov (United States)

    Secor, Stephen M; Taylor, Josi R; Grosell, Martin

    2012-01-01

    manifested in a depressed gastric and intestinal metabolism, which selectively serves to reduce basal metabolism and hence promote survival between infrequent meals. By maintaining elevated GI performance between meals, fasted water snakes incur the additional cost of tissue activity, which is expressed in a higher standard metabolic rate.

  6. Higher rates of metabolic syndrome among women taking zidovudine as compared to tenofovir in rural Africa: preliminary data from the CART-1 study

    Directory of Open Access Journals (Sweden)

    Niklaus Daniel Labhardt

    2014-11-01

    Full Text Available Introduction: Due to its side effects stavudine (D4T has been replaced by zidovudine (AZT and tenofovir (TDF in most low- and middle-income countries (LMICs. In 2014 about 38% of adult first-line regimens contain AZT and 62% TDF [1]. Whereas the unfavourable metabolic outcomes of D4T in comparison to TDF have been described extensively, studies from LMICs comparing metabolic profiles between patients on AZT and TDF are scarce. Given the high number of patients in LMICs still taking AZT, data on their metabolic profile are needed. We present rates of metabolic syndrome (MS in adult patients taking either AZT- or TDF-containing first-line, non-nucleoside reverse transcriptase (NNRTI-based regimens. Materials and Methods: Data derived from a cross-sectional multi-disease screening conducted in ten facilities in two rural districts of Lesotho, Southern Africa [2]. Patients were eligible if aged ≥25 years and on NNRTI-containing first-line ART ≥6 months. The MS definition for Africa of the International Diabetes Federation was applied [3]. Assessed potential predictors for MS were age, time on ART, virologic suppression, body-mass index (BMI, alcohol consumption, wealth quintile, NNRTI (nevirapine (NVP or Efavirenz (EFV, history of previous D4T exposure and ART-backbone (AZT or TDF. Statistical analyses – stratified for sex – comprised univariate logistic regression for each predictor variable with subsequent construction of a multivariate model including all predictors with an association to MS at a significance level<0.1 in univariate analysis. Results: Out of 1026 patients, 660 (64.3% were female. MS prevalence was 9.8% (95% CI 6.9–13.4 in men and 22.9% (19.7–26.3 in women. In women, aged ≥35 years, AZT-backbone, NVP-base, BMI ≥25kg/m2 and taking ART for ≥4.5 years were associated with MS in univariate analysis. In the multivariate model only AZT (adjusted odds-ratio: 2.2, 95% CI 1.4–3.6; p=0.001 and BMI ≥25kg/m2 (9.8; 2.8

  7. Higher rates of metabolic syndrome among women taking zidovudine as compared to tenofovir in rural Africa: preliminary data from the CART-1 study

    Science.gov (United States)

    Labhardt, Niklaus Daniel; Cheleboi, Molisana; Faturyiele, Olatunbosun; Motlatsi, Mokete M; Pfeiffer, Karolin; Ismael Lejone, Thabo; Cerutti, Bernard; Muser, Jürgen; Shankar Gupta, Ravi; Lynen, Lutgarde; Hatz, Christoph

    2014-01-01

    Introduction Due to its side effects stavudine (D4T) has been replaced by zidovudine (AZT) and tenofovir (TDF) in most low- and middle-income countries (LMICs). In 2014 about 38% of adult first-line regimens contain AZT and 62% TDF [1]. Whereas the unfavourable metabolic outcomes of D4T in comparison to TDF have been described extensively, studies from LMICs comparing metabolic profiles between patients on AZT and TDF are scarce. Given the high number of patients in LMICs still taking AZT, data on their metabolic profile are needed. We present rates of metabolic syndrome (MS) in adult patients taking either AZT- or TDF-containing first-line, non-nucleoside reverse transcriptase (NNRTI)-based regimens. Materials and Methods Data derived from a cross-sectional multi-disease screening conducted in ten facilities in two rural districts of Lesotho, Southern Africa [2]. Patients were eligible if aged ≥25 years and on NNRTI-containing first-line ART ≥6 months. The MS definition for Africa of the International Diabetes Federation was applied [3]. Assessed potential predictors for MS were age, time on ART, virologic suppression, body-mass index (BMI), alcohol consumption, wealth quintile, NNRTI (nevirapine (NVP) or Efavirenz (EFV)), history of previous D4T exposure and ART-backbone (AZT or TDF). Statistical analyses – stratified for sex – comprised univariate logistic regression for each predictor variable with subsequent construction of a multivariate model including all predictors with an association to MS at a significance level<0.1 in univariate analysis. Results Out of 1026 patients, 660 (64.3%) were female. MS prevalence was 9.8% (95% CI 6.9–13.4) in men and 22.9% (19.7–26.3) in women. In women, aged ≥35 years, AZT-backbone, NVP-base, BMI ≥25kg/m2 and taking ART for ≥4.5 years were associated with MS in univariate analysis. In the multivariate model only AZT (adjusted odds-ratio: 2.2, 95% CI 1.4–3.6; p=0.001) and BMI ≥25kg/m2 (9.8; 2.8–34.1, p

  8. Microbial biomass and basal respiration in Sub-Antarctic and Antarctic soils in the areas of some Russian polar stations

    Directory of Open Access Journals (Sweden)

    E. Abakumov

    2014-03-01

    Full Text Available Antarctica is the unique place for pedological investigations. Soils of Antarctica have been studied intensively during the last century. Antarctic logistic provides the possibility to scientists access the terrestrial landscapes mainly in the places of polar stations. That is why the main and most detailed pedological investigations were conducted in Mc Murdo Valleys, Transantarctic Mountains, South Shetland Islands, Larsemann hills and Schirmacher Oasis. Investigations were conducted during the 53rd and 55th Russian Antarctic expeditions on the base of soil pits and samples collected in Sub-Antarctic and Antarctic regions. Soils of diverse Antarctic landscapes were studied with aim to assess the microbial biomass level, basal respiration rates and metabolic activity of microbial communities. The investigation conducted shows that soils of Antarctic are quite different in profile organization and carbon content. In general, Sub-Antarctic soils are characterized by more developed humus (sod organo-mineral horizons as well as the upper organic layer. The most developed organic layers were revealed in peat soils of King-George Island, where its thickness reach even 80 cm. These soils as well as soils under guano are characterized by the highest amount of total organic carbon (TOC 7.22–33.70%. Coastal and continental soils of Antarctic are presented by less developed Leptosols, Gleysols, Regolith and rare Ornhitosol with TOC levels about 0.37–4.67%. The metabolic ratios and basal respiration were higher in Sub-Antarctic soils than in Antarctic ones which can be interpreted as result of higher amounts of fresh organic remnants in organic and organo-mineral horizons. Also the soils of King-George island have higher portion of microbial biomass (max 1.54 mg g−1 than coastal (max 0.26 mg g−1 and continental (max 0.22 mg g−1 Antarctic soils. Sub-Antarctic soils mainly differ from Antarctic ones in increased organic layers thickness and total

  9. Identification of triple-negative and basal-like canine mammary carcinomas using four basal markers.

    Science.gov (United States)

    Kim, N H; Lim, H Y; Im, K S; Kim, J H; Sur, J-H

    2013-05-01

    Molecular-based classification of canine mammary carcinomas (CMCs) has been a recent research focus. In human breast cancer, triple-negative and basal-like phenotypes are distinct molecular subgroups that are known for their poor prognosis, but these tumours are not yet well defined in the dog. The aim of this study was to determine whether CMCs include triple-negative and basal-like phenotypes by immunohistochemical assessment of expression of the oestrogen receptor (OR), progesterone receptor (PR), human epidermal growth factor receptor 2 (HER2) and four basal markers, cytokeratin (CK) 14, CK5/6, p63 and the epidermal growth factor receptor (EGFR). In this study of 241 CMCs, 45 triple-negative tumours (OR(-), PR(-) and HER2(-)) were identified and this phenotype was associated with an unfavourable prognosis. In these tumours, the expression of CK14, CK5/6 and EGFR was related to clinicopathological parameters, while the expression of p63 was not relevant. The majority of the triple-negative tumours were of the basal-like phenotype, given that 75.6% of them expressed more than two basal markers. However, three of the basal markers were not uniformly expressed; therefore, the proportion of the basal-like phenotype was altered on the basis of the selection of the markers. Although both triple-negative and basal-like phenotypes are distinct entities in CMC, further study is needed to differentiate one from the other.

  10. Metabolism and Excretion Rates of Parent and Hydroxy-PAHs in Urine Collected after Consumption of Traditionally Smoked Salmon for Native American Volunteers

    Science.gov (United States)

    Motorykin, Oleksii; Santiago-Delgado, Lisandra; Rohlman, Diana; Schrlau, Jill E.; Harper, Barbara; Harris, Stuart; Harding, Anna; Kile, Molly L.; Massey Simonich, Staci L.

    2015-01-01

    Few studies have been published on the excretion rates of parent polycyclic aromatic hydrocarbons (PAHs) and hydroxy-polycyclic aromatic hydrocarbons (OH-PAHs) following oral exposure. This study investigated metabolism and excretion rates of 4 parent PAHs and 10 OH-PAHs after the consumption of smoked salmon. Nine members of the Confederated Tribes of the Umatilla Indian Reservation consumed 50 g of traditionally smoked salmon with breakfast and five urine samples were collected during the following 24 hours. The concentrations of OH-PAHs increased from 43.9 μg/g creatinine for 2-OH-Nap to 349 ng/g creatinine for 1-OH-Pyr, 3 to 6 hr post-consumption. Despite volunteers following a restricted diet, there appeared to be a secondary source of naphthalene and fluorene, which led to excretion efficiencies greater than 100%. For the parent PAHs that were detected in urine, the excretion efficiencies ranged from 13% for phenanthrene (and its metabolite) to 240% for naphthalene (and its metabolites). The half-lives for PAHs ranged from 1.4 hr for retene to 3.3 hr for pyrene. The half-lives for OH-PAHs were higher and ranged from 1.7 hr for 9-OH-fluorene to 7.0 hr for 3-OH-fluorene. The concentrations of most parent PAHs, and their metabolites, returned to the background levels 24 hr post-consumption. PMID:25659315

  11. Self-Rated Health in middle-aged and elderly Chinese: distribution, determinants and associations with cardio-metabolic risk factors

    Directory of Open Access Journals (Sweden)

    Yu Zhijie

    2009-09-01

    Full Text Available Abstract Background Self-rated health (SRH has been demonstrated to be an accurate reflection of a person's health and a valid predictor of incident mortality and chronic morbidity. We aimed to evaluate the distribution and factors associated with SRH and its association with biomarkers of cardio-metabolic diseases among middle-aged and elderly Chinese. Methods Survey of 1,458 men and 1,831 women aged 50 to 70 years, conducted in one urban and two rural areas of Beijing and Shanghai in 2005. SRH status was measured and categorized as good (very good and good vs. not good (fair, poor and very poor. Determinants of SRH and associations with biomarkers of cardio-metabolic diseases were evaluated using logistic regression. Results Thirty two percent of participants reported good SRH. Males and rural residents tended to report good SRH. After adjusting for potential confounders, residence, physical activity, employment status, sleep quality and presence of diabetes, cardiovascular disease, and depression were the main determinants of SRH. Those free from cardiovascular disease (OR 3.68; 95%CI 2.39; 5.66, rural residents (OR 1.89; 95% CI 1.47; 2.43, non-depressed participants (OR 2.50; 95% CI 1.67; 3.73 and those with good sleep quality (OR 2.95; 95% CI 2.22; 3.91 had almost twice or over the chance of reporting good SRH compared to their counterparts. There were significant associations -and trend- between SRH and levels of inflammatory markers, insulin levels and insulin resistance. Conclusion Only one third of middle-aged and elderly Chinese assessed their health status as good or very good. Although further longitudinal studies are required to confirm our findings, interventions targeting social inequalities, lifestyle patterns might not only contribute to prevent chronic morbidity but as well to improve populations' perceived health.

  12. Post-hatching development of mitochondrial function, organ mass and metabolic rate in two ectotherms, the American alligator (Alligator mississippiensis) and the common snapping turtle (Chelydra serpentina).

    Science.gov (United States)

    Sirsat, Sarah K G; Sirsat, Tushar S; Price, Edwin R; Dzialowski, Edward M

    2016-04-15

    The ontogeny of endothermy in birds is associated with disproportionate growth of thermogenic organs and increased mitochondrial oxidative capacity. However, no similar study has been made of the development of these traits in ectotherms. For comparison, we therefore investigated the metabolism, growth and muscle mitochondrial function in hatchlings of a turtle and a crocodilian, two ectotherms that never develop endothermy. Metabolic rate did not increase substantially in either species by 30 days post-hatching. Yolk-free body mass and heart mass did not change through 30 days in alligators and heart mass was a constant proportion of body mass, even after 1 year. Yolk-free body mass and liver mass grew 36% and 27%, respectively, in turtles during the first 30 days post-hatch. The mass-specific oxidative phosphorylation capacity of mitochondria, assessed using permeabilized muscle fibers, increased by a non-significant 47% in alligator thigh and a non-significant 50% in turtle thigh over 30 days, but did not increase in the heart. This developmental trajectory of mitochondrial function is slower and shallower than that previously observed in ducks, which demonstrate a 90% increase in mass-specific oxidative phosphorylation capacity in thigh muscles over just a few days, a 60% increase in mass-specific oxidative phosphorylation capacity of the heart over a few days, and disproportionate growth of the heart and other organs. Our data thus support the hypothesis that these developmental changes in ducks represent mechanistic drivers for attaining endothermy.

  13. Post-hatching development of mitochondrial function, organ mass and metabolic rate in two ectotherms, the American alligator (Alligator mississippiensis and the common snapping turtle (Chelydra serpentina

    Directory of Open Access Journals (Sweden)

    Sarah K. G. Sirsat

    2016-04-01

    Full Text Available The ontogeny of endothermy in birds is associated with disproportionate growth of thermogenic organs and increased mitochondrial oxidative capacity. However, no similar study has been made of the development of these traits in ectotherms. For comparison, we therefore investigated the metabolism, growth and muscle mitochondrial function in hatchlings of a turtle and a crocodilian, two ectotherms that never develop endothermy. Metabolic rate did not increase substantially in either species by 30 days post-hatching. Yolk-free body mass and heart mass did not change through 30 days in alligators and heart mass was a constant proportion of body mass, even after 1 year. Yolk-free body mass and liver mass grew 36% and 27%, respectively, in turtles during the first 30 days post-hatch. The mass-specific oxidative phosphorylation capacity of mitochondria, assessed using permeabilized muscle fibers, increased by a non-significant 47% in alligator thigh and a non-significant 50% in turtle thigh over 30 days, but did not increase in the heart. This developmental trajectory of mitochondrial function is slower and shallower than that previously observed in ducks, which demonstrate a 90% increase in mass-specific oxidative phosphorylation capacity in thigh muscles over just a few days, a 60% increase in mass-specific oxidative phosphorylation capacity of the heart over a few days, and disproportionate growth of the heart and other organs. Our data thus support the hypothesis that these developmental changes in ducks represent mechanistic drivers for attaining endothermy.

  14. Basal ganglia calcification as a putative cause for cognitive decline

    Directory of Open Access Journals (Sweden)

    João Ricardo Mendes de Oliveira

    Full Text Available ABSTRACT Basal ganglia calcifications (BGC may be present in various medical conditions, such as infections, metabolic, psychiatric and neurological diseases, associated with different etiologies and clinical outcomes, including parkinsonism, psychosis, mood swings and dementia. A literature review was performed highlighting the main neuropsychological findings of BGC, with particular attention to clinical reports of cognitive decline. Neuroimaging studies combined with neuropsychological analysis show that some patients have shown progressive disturbances of selective attention, declarative memory and verbal perseveration. Therefore, the calcification process might represent a putative cause for dementia syndromes, suggesting a probable link among calcinosis, the aging process and eventually with neuronal death. The increasing number of reports available will foster a necessary discussion about cerebral calcinosis and its role in determining symptomatology in dementia patients

  15. Radiologic study of basal cell nevus syndrome

    Energy Technology Data Exchange (ETDEWEB)

    Park, Tae Won [Dept. of Oral Radiology, College of Dentistry, Seoul National University, Seoul (Korea, Republic of)

    1988-11-15

    Several cases of jaw cyst-basal cell nevus-bifid rib syndrome are presented. This syndrome consists principally of multiple jaw cysts, basal cell nevi, and bifid ribs but no one component is present in all patients. The purpose of this paper is to review the multiple characteristics of this syndrome and present three cases in a family and additional 4 cases. The many malformations associated with the syndrome have variable expressively. In the cases, multiple jaw cysts, pal mar and plantar pittings, bridging of sella, temporoparietal bossing, hypertelorism, cleft palate, and dystopia canthoru m have been observed.

  16. Early Detection of Regional and Global Left Ventricular Myocardial Function Using Strain and Strain-rate Imaging in Patients with Metabolic Syndrome

    Institute of Scientific and Technical Information of China (English)

    Qin Wang; Qi-Wei Sun; Dan Wu; Ming-Wu Yang; Rong-Juan Li; Bo Jiang; Jiao Yang

    2015-01-01

    Background:Strain and strain-rate imaging (SRI) have been found clinically useful in the assessment of cardiac systolic and diastolic function as well as providing new insights in deciphering cardiac physiology and mechanics in cardiomyopathies,and identifying early subclinical changes in various pathologies.The aim of this study was to evaluate the regional and global left ventricular (LV) myocardial function in metabolic syndrome (MS) with SRI so that we can provide more myocardial small lesions in patients with MS,which is robust and reliable basis for early detection of LV function.Methods:Thirty-nine adults with MS were enrolled in the study.There was a control group of 39 healthy adults.In addition to classic echocardiographic assessment of LV global functional changes,SRI was used to evaluate regional and global LV function.Including:Peak systolic strain (S),peak systolic strain-rate (SR-s),peak diastolic strain-rate (SR-e).Results:There were no statistically significant differences between MS and controls in all traditional parameters of LV systolic function.On the other hand,significant differences were observed between MS and the control group in most of the parameters of S,SR-s,SR-e in regional LV function.Multiple stepwise regression analyses revealed that S and SR significantly were negatively correlated with blood pressure,waist circumference,fasting plasma glucose,uric acid,suggesting that risk factories were relevant to regional systolic dysfunction.Conclusion:In MS with normal LV ejection fraction,there was regional myocardial dysfunction,risk factors contributed to the impairment of systolic and diastolic function of the regional myocardium.Assessment of myocardial function using SRI could be more accurate in MS patient evaluation than conventional echocardiography alone.

  17. Early Detection of Regional and Global Left Ventricular Myocardial Function Using Strain and Strain-rate Imaging in Patients with Metabolic Syndrome

    Directory of Open Access Journals (Sweden)

    Qin Wang

    2015-01-01

    Full Text Available Background: Strain and strain-rate imaging (SRI have been found clinically useful in the assessment of cardiac systolic and diastolic function as well as providing new insights in deciphering cardiac physiology and mechanics in cardiomyopathies, and identifying early subclinical changes in various pathologies. The aim of this study was to evaluate the regional and global left ventricular (LV myocardial function in metabolic syndrome (MS with SRI so that we can provide more myocardial small lesions in patients with MS, which is robust and reliable basis for early detection of LV function. Methods: Thirty-nine adults with MS were enrolled in the study. There was a control group of 39 healthy adults. In addition to classic echocardiographic assessment of LV global functional changes, SRI was used to evaluate regional and global LV function. Including: Peak systolic strain (S, peak systolic strain-rate (SR-s, peak diastolic strain-rate (SR-e. Results: There were no statistically significant differences between MS and controls in all traditional parameters of LV systolic function. On the other hand, significant differences were observed between MS and the control group in most of the parameters of S, SR-s, SR-e in regional LV function. Multiple stepwise regression analyses revealed that S and SR significantly were negatively correlated with blood pressure, waist circumference, fasting plasma glucose, uric acid, suggesting that risk factories were relevant to regional systolic dysfunction. Conclusion: In MS with normal LV ejection fraction, there was regional myocardial dysfunction, risk factors contributed to the impairment of systolic and diastolic function of the regional myocardium. Assessment of myocardial function using SRI could be more accurate in MS patient evaluation than conventional echocardiography alone.

  18. Effects of whole-body electromyostimulation on resting metabolic rate, body composition, and maximum strength in postmenopausal women: the Training and ElectroStimulation Trial.

    Science.gov (United States)

    Kemmler, Wolfgang; Schliffka, Rebecca; Mayhew, Jerry L; von Stengel, Simon

    2010-07-01

    We evaluated the effect of whole-body electromyostimulation (WB-EMS) during dynamic exercises over 14 weeks on anthropometric, physiological, and muscular parameters in postmenopausal women. Thirty women (64.5 +/- 5.5 years) with experience in physical training (>3 years) were randomly assigned either to a control group (CON, n = 15) that maintained their general training program (2 x 60 min.wk of endurance and dynamic strength exercise) or to an electromyostimulation group (WB-EMS, n = 15) that additionally performed a 20-minute WB-EMS training (2 x 20 min.10 d). Resting metabolic rate (RMR) determined from spirometry was selected to indicate muscle mass. In addition, body circumferences, subcutaneous skinfolds, strength, power, and dropout and adherence values. Resting metabolic rate was maintained in WB-EMS (-0.1 +/- 4.8 kcal.h) and decreased in CON (-3.2+/-5.2 kcal.h, p = 0.038); although group differences were not significant (p = 0.095), there was a moderately strong effect size (ES = 0.62). Sum of skinfolds (28.6%) and waist circumference (22.3%) significantly decreased in WB-EMS whereas both parameters (1.4 and 0.1%, respectively) increased in CON (p = 0.001, ES = 1.37 and 1.64, respectively), whereas both parameters increased in CON (1.4 and 0.1%, respectively). Isometric strength changes of the trunk extensors and leg extensors differed significantly (p < or = 0.006) between WB-EMS and CON (9.9% vs. -6.4%, ES = 1.53; 9.6% vs. -4.5%, ES = 1.43, respectively). In summary, adjunct WB-EMS training significantly exceeds the effect of isolated endurance and resistance type exercise on fitness and fatness parameters. Further, we conclude that for elderly subjects unable or unwilling to perform dynamic strength exercises, electromyostimulation may be a smooth alternative to maintain lean body mass, strength, and power.

  19. Expression of stromelysin 3 in basal cell carcinomas.

    Science.gov (United States)

    Cribier, B; Noacco, G; Peltre, B; Grosshans, E

    2001-01-01

    Stromelysin 3 is a member of the metalloproteinase family, which is expressed in various remodelling processes. The prognosis of breast cancers and squamous cell carcinomas is correlated to the level of expression of this protein. The purpose of the present work was to evaluate the expression of stromelysin 3 in the major types of basal cell carcinomas. We selected cases of primary tumours that were fully excised, without previous biopsy: 40 Pinkus tumors, 40 superficial, 40 nodular, 38 morpheiform basal cell carcinomas and 10 cases showing deep subcutaneous or muscular invasion. Immunohistochemistry was carried out using monoclonal anti-ST3 antibodies (MC Rio, IGBMC Strasbourg), and evaluated on a semi-quantitative scale from 0 to 3. Positively stained cells were restricted to the periphery of the epithelial cells, which, by contrast, never expressed stromelysin 3. The global rate of expression was 27% in Pinkus tumors, 65% in superficial, 72.5% in nodular, 87% in morpheiform and 100% in deeply invasive carcinomas. The rates of tumours showing the highest number of positively stained cells (class 2 or 3) were respectively 7.5%, 20%, 45%, 63% and 100%. This systematic study of stromelysin3 expression in basal cell carcinomas confirms that it is a marker of poor prognosis, because the rate of positive tumours was much higher in aggressive carcinomas. Moreover, the majority of tumours showing an intense expression (i.e. the highest number of positively stained cells in their stroma) were of the morpheiform and deeply invasive types, which are of poor prognosis. Altogether, the studies performed on cutaneous tumours are consistent with the theory of stromelysin 3 playing an active role in tumour progression.

  20. Basal Cell Carcinoma in The Netherlands

    NARCIS (Netherlands)

    S.C. Flohil (Sophie)

    2012-01-01

    textabstractThere are many different cutaneous malignancies, but malignant melanoma, squamous cell carcinoma (SCC) and basal cell carcinoma (BCC) represent approximately 98% of all skin cancers.In literature, these three skin cancers are often divided into melanoma and nonmelanoma skin cancers (NMSC

  1. Immunosuppressive Environment in Basal Cell Carcinoma

    DEFF Research Database (Denmark)

    Omland, Silje H; Nielsen, Patricia S; Gjerdrum, Lise M R;

    2016-01-01

    Interaction between tumour survival tactics and anti-tumour immune response is a major determinant for cancer growth. Regulatory T cells (T-regs) contribute to tumour immune escape, but their role in basal cell carcinoma (BCC) is not understood. The fraction of T-regs among T cells was analysed...

  2. Parallel basal ganglia circuits for decision making.

    Science.gov (United States)

    Hikosaka, Okihide; Ghazizadeh, Ali; Griggs, Whitney; Amita, Hidetoshi

    2017-02-02

    The basal ganglia control body movements, mainly, based on their values. Critical for this mechanism is dopamine neurons, which sends unpredicted value signals, mainly, to the striatum. This mechanism enables animals to change their behaviors flexibly, eventually choosing a valuable behavior. However, this may not be the best behavior, because the flexible choice is focused on recent, and, therefore, limited, experiences (i.e., short-term memories). Our old and recent studies suggest that the basal ganglia contain separate circuits that process value signals in a completely different manner. They are insensitive to recent changes in value, yet gradually accumulate the value of each behavior (i.e., movement or object choice). These stable circuits eventually encode values of many behaviors and then retain the value signals for a long time (i.e., long-term memories). They are innervated by a separate group of dopamine neurons that retain value signals, even when no reward is predicted. Importantly, the stable circuits can control motor behaviors (e.g., hand or eye) quickly and precisely, which allows animals to automatically acquire valuable outcomes based on historical life experiences. These behaviors would be called 'skills', which are crucial for survival. The stable circuits are localized in the posterior part of the basal ganglia, separately from the flexible circuits located in the anterior part. To summarize, the flexible and stable circuits in the basal ganglia, working together but independently, enable animals (and humans) to reach valuable goals in various contexts.

  3. Giant basal cell carcinoma Carcinoma basocelular gigante

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    Nilton Nasser

    2012-06-01

    Full Text Available The basal cell carcinoma is the most common skin cancer but the giant vegetating basal cell carcinoma reaches less than 0.5 % of all basal cell carcinoma types. The Giant BCC, defined as a lesion with more than 5 cm at its largest diameter, is a rare form of BCC and commonly occurs on the trunk. This patient, male, 42 years old presents a Giant Basal Cell Carcinoma which reaches 180 cm2 on the right shoulder and was negligent in looking for treatment. Surgical treatment was performed and no signs of dissemination or local recurrence have been detected after follow up of five years.O carcinoma basocelular é o tipo mais comum de câncer de pele, mas o carcinoma basocelular gigante vegetante não atinge 0,5% de todos os tipos de carcinomas basocelulares. O Carcinoma Basocelular Gigante, definido como lesão maior que 5 cm no maior diâmetro, é uma forma rara de carcinoma basocelular e comumente ocorre no tronco. Este paciente apresenta um Carcinoma Basocelular Gigante com 180cm² no ombro direito e foi negligente em procurar tratamento. Foi realizado tratamento cirúrgico e nenhum sinal de disseminação ou recorrência local foi detectada após 5 anos.

  4. Effect of a vitamin D{sub 3}-based nutritional supplement ('Videchol') on carbohydrate metabolism of rats following chronic low dose-rate irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Starikovich, L.S.; Vernikovska, Ya.I.; Vigovska, T.V.; Veliky, M.M. [Lviv Ivan Franko National University, Department of Biochemistry, Lviv (Ukraine); Becerril Aragon, G.A. [Lviv Ivan Franko National University, Department of Biochemistry, Lviv (Ukraine)]. E-mail: gabriel_aragon@mail.ru

    2001-09-01

    In this study we evaluated the effects of the administration of a vitamin D{sub 3} preparation 'Videchol' to chronically irradiated rats (1 cGy day{sup -1}) by the assessment of the activities of several glycolytic enzymes: lactic dehydrogenase (LDH) (EC 1.1.1.28), pyruvate kinase (PK) (EC 2.7.1.40) and hexokinase (HK) (EC 2.7.1.1), in populations of erythroid and myeloid bone marrow cells. Videchol treatment of irradiated rats led to the normalisation of HK and LDH activity at cumulative doses of around 30 cGy in granulocyte-monocyte cells and to normalisation of LDH and PK activities in erythroid cells starting at 20 cGy in comparison with irradiated rats who did not receive Videchol. The reaction kinetic parameters of LDH in erythrocytes changed according to the redistribution pattern of the isozymes throughout the different stages of the experiment. The administration of Videchol to irradiated rats led to a rearrangement of the LDH isozymes ratio characterised by kinetic properties more comparable to those of the controls. Thus, vitamin D{sub 3} appears to induce a normalisation of carbohydrate metabolism in rats chronically irradiated with low dose-rate ionising radiation. (author)

  5. Direct calorimetry identifies deficiencies in respirometry for the determination of resting metabolic rate in C57Bl/6 and FVB mice.

    Science.gov (United States)

    Burnett, Colin M L; Grobe, Justin L

    2013-10-01

    Substantial research efforts have been aimed at identifying novel targets to increase resting metabolic rate (RMR) as an adjunct approach to the treatment of obesity. Respirometry (one form of "indirect calorimetry") is unquestionably the dominant technique used in the obesity research field to assess RMR in vivo, although this method relies upon a lengthy list of assumptions that are likely to be violated in pharmacologically or genetically manipulated animals. A "total" calorimeter, including a gradient layer direct calorimeter coupled to a conventional respirometer, was used to test the accuracy of respirometric-based estimations of RMR in laboratory mice (Mus musculus Linnaeus) of the C57Bl/6 and FVB background strains. Using this combined calorimeter, we determined that respirometry underestimates RMR of untreated 9- to 12-wk-old male mice by ∼10-12%. Quantitative and qualitative differences resulted between methods for untreated C57Bl/6 and FVB mice, C57Bl/6 mice treated with ketamine-xylazine anesthesia, and FVB mice with genetic deletion of the angiotensin II type 2 receptor. We conclude that respirometric methods underestimate RMR in mice in a magnitude that is similar to or greater than the desired RMR effects of novel therapeutics. Sole reliance upon respirometry to assess RMR in mice may lead to false quantitative and qualitative conclusions regarding the effects of novel interventions. Increased use of direct calorimetry for the assessment of RMR and confirmation of respirometry results and the reexamination of previously discarded potential obesity therapeutics are warranted.

  6. Assessment of myocardial metabolic rate of glucose by means of Bayesian ICA and Markov Chain Monte Carlo methods in small animal PET imaging

    Science.gov (United States)

    Berradja, Khadidja; Boughanmi, Nabil

    2016-09-01

    In dynamic cardiac PET FDG studies the assessment of myocardial metabolic rate of glucose (MMRG) requires the knowledge of the blood input function (IF). IF can be obtained by manual or automatic blood sampling and cross calibrated with PET. These procedures are cumbersome, invasive and generate uncertainties. The IF is contaminated by spillover of radioactivity from the adjacent myocardium and this could cause important error in the estimated MMRG. In this study, we show that the IF can be extracted from the images in a rat heart study with 18F-fluorodeoxyglucose (18F-FDG) by means of Independent Component Analysis (ICA) based on Bayesian theory and Markov Chain Monte Carlo (MCMC) sampling method (BICA). Images of the heart from rats were acquired with the Sherbrooke small animal PET scanner. A region of interest (ROI) was drawn around the rat image and decomposed into blood and tissue using BICA. The Statistical study showed that there is a significant difference (p < 0.05) between MMRG obtained with IF extracted by BICA with respect to IF extracted from measured images corrupted with spillover.

  7. Validity of using a 3-dimensional PET scanner during inhalation of 15O-labeled oxygen for quantitative assessment of regional metabolic rate of oxygen in man.

    Science.gov (United States)

    Hori, Yuki; Hirano, Yoshiyuki; Koshino, Kazuhiro; Moriguchi, Tetsuaki; Iguchi, Satoshi; Yamamoto, Akihide; Enmi, Junichiro; Kawashima, Hidekazu; Zeniya, Tsutomu; Morita, Naomi; Nakagawara, Jyoji; Casey, Michael E; Iida, Hidehiro

    2014-09-21

    Use of 15O labeled oxygen (15O2) and positron emission tomography (PET) allows quantitative assessment of the regional metabolic rate of oxygen (CMRO2) in vivo, which is essential to understanding the pathological status of patients with cerebral vascular and neurological disorders. The method has, however, been challenging, when a 3D PET scanner is employed, largely attributed to the presence of gaseous radioactivity in the trachea and the inhalation system, which results in a large amount of scatter and random events in the PET assessment. The present study was intended to evaluate the adequacy of using a recently available commercial 3D PET scanner in the assessment of regional cerebral radioactivity distribution during an inhalation of 15O2. Systematic experiments were carried out on a brain phantom. Experiments were also performed on a healthy volunteer following a recently developed protocol for simultaneous assessment of CMRO2 and cerebral blood flow, which involves sequential administration of 15O2 and C15O2. A particular intention was to evaluate the adequacy of the scatter-correction procedures. The phantom experiment demonstrated that errors were within 3% at the practically maximum radioactivity in the face mask, with the greatest radioactivity in the lung. The volunteer experiment demonstrated that the counting rate was at peak during the 15O gas inhalation period, within a verified range. Tomographic images represented good quality over the entire FOV, including the lower part of the cerebral structures and the carotid artery regions. The scatter-correction procedures appeared to be important, particularly in the process to compensate for the scatter originating outside the FOV. Reconstructed images dramatically changed if the correction was carried out using inappropriate procedures. This study demonstrated that accurate reconstruction could be obtained when the scatter compensation was appropriately carried out. This study also suggested the

  8. Basal cell adenoma of the parotid gland. Case report and review of the literature.

    Science.gov (United States)

    González-García, Raúl; Nam-Cha, Syong H; Muñoz-Guerra, Mario F; Gamallo-Amat, C

    2006-03-01

    Basal cell adenoma of the salivary glands is an uncommon type of monomorphous adenoma. Its most frequent location is the parotid gland. It usually appears as a firm and mobile slow-growing mass. Histologically, isomorphic cells in nests and interlaced trabecules with a prominent basal membrane are observed. It is also characterized by the presence of a slack and hyaline stroma and the absence of myxoid or condroid stroma. In contrast to pleomorphic adenoma, it tends to be multiple and its recurrence rate after surgical excision is high. Due to prognostic implications, differential diagnosis with basal cell adenocarcinoma, adenoid cystic carcinoma and basaloid squamous cell carcinoma is mandatory. We describe a case of basal cell adenoma of the parotid gland. We also review the literature and discuss the diagnosis and management of this rare entity.

  9. Brain structure evolution in a basal vertebrate clade: evidence from phylogenetic comparative analysis of cichlid fishes

    Directory of Open Access Journals (Sweden)

    Kolm Niclas

    2009-09-01

    Full Text Available Abstract Background The vertebrate brain is composed of several interconnected, functionally distinct structures and much debate has surrounded the basic question of how these structures evolve. On the one hand, according to the 'mosaic evolution hypothesis', because of the elevated metabolic cost of brain tissue, selection is expected to target specific structures mediating the cognitive abilities which are being favored. On the other hand, the 'concerted evolution hypothesis' argues that developmental constraints limit such mosaic evolution and instead the size of the entire brain varies in response to selection on any of its constituent parts. To date, analyses of these hypotheses of brain evolution have been limited to mammals and birds; excluding Actinopterygii, the basal and most diverse class of vertebrates. Using a combination of recently developed phylogenetic multivariate allometry analyses and comparative methods that can identify distinct rates of evolution, even in highly correlated traits, we studied brain structure evolution in a highly variable clade of ray-finned fishes; the Tanganyikan cichlids. Results Total brain size explained 86% of the variance in brain structure volume in cichlids, a lower proportion than what has previously been reported for mammals. Brain structures showed variation in pair-wise allometry suggesting some degree of independence in evolutionary changes in size. This result is supported by variation among structures on the strength of their loadings on the principal size axis of the allometric analysis. The rate of evolution analyses generally supported the results of the multivariate allometry analyses, showing variation among several structures in their evolutionary patterns. The olfactory bulbs and hypothalamus were found to evolve faster than other structures while the dorsal medulla presented the slowest evolutionary rate. Conclusion Our results favor a mosaic model of brain evolution, as certain

  10. Field measurement of basal forces generated by erosive debris flows

    Science.gov (United States)

    McCoy, S.W.; Tucker, G.E.; Kean, J.W.; Coe, J.A.

    2013-01-01

    It has been proposed that debris flows cut bedrock valleys in steeplands worldwide, but field measurements needed to constrain mechanistic models of this process remain sparse due to the difficulty of instrumenting natural flows. Here we present and analyze measurements made using an automated sensor network, erosion bolts, and a 15.24 cm by 15.24 cm force plate installed in the bedrock channel floor of a steep catchment. These measurements allow us to quantify the distribution of basal forces from natural debris‒flow events that incised bedrock. Over the 4 year monitoring period, 11 debris‒flow events scoured the bedrock channel floor. No clear water flows were observed. Measurements of erosion bolts at the beginning and end of the study indicated that the bedrock channel floor was lowered by 36 to 64 mm. The basal force during these erosive debris‒flow events had a large‒magnitude (up to 21 kN, which was approximately 50 times larger than the concurrent time‒averaged mean force), high‒frequency (greater than 1 Hz) fluctuating component. We interpret these fluctuations as flow particles impacting the bed. The resulting variability in force magnitude increased linearly with the time‒averaged mean basal force. Probability density functions of basal normal forces were consistent with a generalized Pareto distribution, rather than the exponential distribution that is commonly found in experimental and simulated monodispersed granular flows and which has a lower probability of large forces. When the bed sediment thickness covering the force plate was greater than ~ 20 times the median bed sediment grain size, no significant fluctuations about the time‒averaged mean force were measured, indicating that a thin layer of sediment (~ 5 cm in the monitored cases) can effectively shield the subjacent bed from erosive impacts. Coarse‒grained granular surges and water‒rich, intersurge flow had very similar basal force distributions despite

  11. Correlation transfer from basal ganglia to thalamus in Parkinson's disease.

    Science.gov (United States)

    Reitsma, Pamela; Doiron, Brent; Rubin, Jonathan

    2011-01-01

    Spike trains from neurons in the basal ganglia of parkinsonian primates show increased pairwise correlations, oscillatory activity, and burst rate compared to those from neurons recorded during normal brain activity. However, it is not known how these changes affect the behavior of downstream thalamic neurons. To understand how patterns of basal ganglia population activity may affect thalamic spike statistics, we study pairs of model thalamocortical (TC) relay neurons receiving correlated inhibitory input from the internal segment of the globus pallidus (GPi), a primary output nucleus of the basal ganglia. We observe that the strength of correlations of TC neuron spike trains increases with the GPi correlation level, and bursty firing patterns such as those seen in the parkinsonian GPi allow for stronger transfer of correlations than do firing patterns found under normal conditions. We also show that the T-current in the TC neurons does not significantly affect correlation transfer, despite its pronounced effects on spiking. Oscillatory firing patterns in GPi are shown to affect the timescale at which correlations are best transferred through the system. To explain this last result, we analytically compute the spike count correlation coefficient for oscillatory cases in a reduced point process model. Our analysis indicates that the dependence of the timescale of correlation transfer is robust to different levels of input spike and rate correlations and arises due to differences in instantaneous spike correlations, even when the long timescale rhythmic modulations of neurons are identical. Overall, these results show that parkinsonian firing patterns in GPi do affect the transfer of correlations to the thalamus.

  12. Anhedonia in the psychosis risk syndrome: associations with social impairment and basal orbitofrontal cortical activity

    OpenAIRE

    Cressman, Victoria L.; Schobel, Scott A.; Steinfeld, Sara; Ben-David, Shelly; Judy L. Thompson; Small, Scott A.; Moore, Holly; Corcoran, Cheryl M.

    2015-01-01

    Background/Objectives: Anhedonia is associated with poor social function in schizophrenia. Here, we examined this association in individuals at clinical high risk (CHR) for schizophrenia and related psychotic disorders, taking into account social anxiety. We then explored correlations between anhedonia and basal metabolic activity in selected forebrain regions implicated in reward processing. Methods: In 62 CHR individuals and 37 healthy controls, we measured social adjustment (Social Adjustm...

  13. Cerebral gigantism associated with jaw cyst basal cell naevoid syndrome in two families.

    Science.gov (United States)

    Cramer, H; Niederdellmann, H

    1983-01-01

    We report 9 subjects from 2 families with the syndrome of cerebral gigantism, seven of the patients also had jaw cyst basal cell naevoid syndrome. Neurological, radiological, somatic and biochemical features of this hitherto unreported association are described. Neurological symptoms included mild hydrocephalus, ventricular malformation, cerebellar syndrome, intracranial calcification, oculomotor disturbances, EEG abnormalities and rarely, mild peripheral nervous disorders. A disturbance of calcium metabolism appears to be a prominent feature of the genetically determined nonprogressive syndrome.

  14. Lymphatic and blood vessels in basal and triple-negative breast cancers: characteristics and prognostic significance.

    Science.gov (United States)

    Mohammed, Rabab A A; Ellis, Ian O; Mahmmod, Ali M; Hawkes, E Claire; Green, Andrew R; Rakha, Emad A; Martin, Stewart G

    2011-06-01

    Basal and triple-negative breast cancer phenotypes are characterised by unfavourable biological behaviour and outcome. Although certain studies have examined their pathological and molecular profile, the vascular characteristics of lymphatic and blood vessels have not been examined. Immunohistochemical staining with podoplanin, CD34 and CD31 was used to examine lymphatic and microvessel density, as well as vascular invasion in 197 basal-like and in 99 triple-negative breast tumours and compared against 200 non-basal and 334 non-triple-negative cases. All specimens were lymph node negative. Vascular invasion was identified as blood or lymphatic vascular invasion by the differential expression of markers. All measurements were correlated with clinicopathological features and prognosis. No significant difference was detected between the basal and triple-negative groups in terms of lymphatic or microvessel density or vascular invasion. However, both the basal and the triple-negative groups showed significantly higher microvessel density than did the non-basal and non-triple-negative groups (P=0.017 and Pcontrols. Interestingly, vascular invasion, almost entirely lymphatic invasion, was detected in 27% of the basal and in 26% of the triple-negative groups with no significant difference in comparison with control groups. In both basal and triple negatives, vascular invasion was associated with poorer survival by univariate and multivariate analyses. The 20-year overall survival rate in basal-like tumours was 55% in vascular invasion-positive cases compared with 73% in vascular invasion-negative tumours (P=0.012), and 46% in triple-negative vascular invasion-positive compared with 79% in vascular invasion-negative tumours (P=0.001). Basal-like vs non-basal-like and triple-negative vs non-triple-negative tumours have similar vascular characteristics in terms of lymphatic vessel density and vascular invasion but higher microvessel density, suggesting that such groups may

  15. Change of oxygen free radical metabolism and free amino acids of patients with hyperthyroidism

    Institute of Scientific and Technical Information of China (English)

    Hua-Ling Ruan; Li Zhao; Kun-Quan Guo; Kun Yang; Lin-Xiu Ye; Xue Sun

    2016-01-01

    Objective:To study the change situation of oxygen free radical metabolism and free amino acids of patients with hyperthyroidism.Methods:Eighty-one patients with hyperthyroidism who were treated in our hospital from May 2013 to October 2014 were selected as the observation group, while 81 healthy persons with health examination at the same period were the control group. Then, the serum oxygen free radical indexes and free amino acids of the two groups were respectively detected and compared, and the detection results of patients in the observation group with different etiologic types and basal metabolic rate were also compared. Results:The serum oxygen free radical related indexes of the observation group were all higher than those of the control group; the serum antioxidant related indexes were all lower than those of the control group; and the serum free amino acids levels were all obviously lower than those of the control group. Besides, the detection results of patients with severe hyperthyroidism in the observation group were worse than those of patients with mild and moderate disease, while the detection results of the observation group with different types of hyperthyroidism had no significant differences.Conclusions:The fluctuation of oxygen free radical metabolism and free amino acids of patients with hyperthyroidism are obvious, and the detection results of patients with different basal metabolic rates are also quite obvious.

  16. Intraspecific differences in metabolic rate of Chroeomys olivaceus (Rodentia: Muridae: the effect of thermal acclimation in arid and mesic habitats Diferencias intraespecíficas en la tasa metabólica de Chroeomys olivaceus (Rodentia: Muridae: efecto de la aclimatación térmica en hábitat áridos y mésicos

    Directory of Open Access Journals (Sweden)

    F. Fernando Novoa

    2005-06-01

    Full Text Available Studies of metabolic capacities in rodents have been largely studied at an inter-specific levels, but physiological capacities of populations belonging to the same species have received lesser attention. Here we studied the maximum and basal metabolic rates of two populations of the rodent Chroeomys olivaceus dwelling in habitats with contrasting temperature and rainfall regimes, and to test if differences in metabolic capacities are due to local adaptation or acclimatization effect. After four weeks of acclimation to 25 ºC and 10 ºC, the BMR and MMR were determined in individuals from the northern population of Caleta Loa, and the southern population of La Picada. Individuals from ‘La Picada’ population were heavier than those from Caleta Loa. MMR and BMR exhibited higher values in cold acclimated animals compared with warm-acclimated animals. Besides, BMR, but not MMR, was lower in Caleta Loa individuals, in spite of the acclimation treatment. Hence, the differences in the metabolic capacities and the response to acclimation of C. olivaceus populations appear to be an evolutionary response to the environmental cuesLas capacidades metabólicas en roedores han sido ampliamente estudiadas en un nivel ínterespecífico, pero los atributos fisiológicos de las poblaciones que pertenecen a una misma especie, han recibido menos atención. Aquí estudiamos las tasas metabólicas máximas y basales de dos poblaciones del roedor Chroeomys olivaceus que viven en habitats con temperaturas y regímenes de precipitaciones contrastantes y se analiza si las diferencias en las capacidades metabólicas se deben a diferenciación local o a efectos de aclimatación. Después de cuatro semanas de aclimatación a 25 ºC y 10 ºC, el BMR y MMR fueron determinados en individuos de la población norteña de Caleta Loa y en la población sureña de "La Picada". Los individuos de la población "La Picada" presentaron mayor masa corporal que los de Caleta Loa. Los

  17. Bilateral germinoma of the basal ganglia.

    Science.gov (United States)

    Rossi, Andrea; Garrè, Maria Luisa; Ravegnani, Marcello; Nozza, Paolo; Abbruzzese, Arturo; Giangaspero, Felice; Tortori-Donati, Paolo

    2008-01-01

    Germinoma arising in the bilateral basal ganglia is exceedingly rare, with only five cases reported to date. Owing to non-specific clinical findings and the frequent presence of ill-defined abnormalities without a definite tumor mass on neuroimaging, the diagnosis can be difficult. We describe a case in which magnetic resonance spectroscopy (MRS) findings suggested a tumor and supported the decision to perform biopsy of the lesion.

  18. Basal ganglia lesions in children and adults

    Energy Technology Data Exchange (ETDEWEB)

    Bekiesinska-Figatowska, Monika, E-mail: m.figatowska@mp.pl [Department of Diagnostic Imaging, Institute of Mother and Child, ul. Kasprzaka 17a, 01-211 Warsaw (Poland); Mierzewska, Hanna, E-mail: h.mierzewska@gmail.com [Department of Neurology of Children and Adolescents, Institute of Mother and Child, ul. Kasprzaka 17a, 01-211 Warsaw (Poland); Jurkiewicz, Elżbieta, E-mail: e-jurkiewicz@o2.pl [Department of Diagnostic Imaging, Children' s Memorial Health Institute, Al. Dzieci Polskich 20, 04-730 Warsaw (Poland)

    2013-05-15

    The term “basal ganglia” refers to caudate and lentiform nuclei, the latter composed of putamen and globus pallidus, substantia nigra and subthalamic nuclei and these deep gray matter structures belong to the extrapyramidal system. Many diseases may present as basal ganglia abnormalities. Magnetic resonance imaging (MRI) and computed tomography (CT) – to a lesser degree – allow for detection of basal ganglia injury. In many cases, MRI alone does not usually allow to establish diagnosis but together with the knowledge of age and circumstances of onset and clinical course of the disease is a powerful tool of differential diagnosis. The lesions may be unilateral: in Rassmussen encephalitis, diabetes with hemichorea/hemiballism and infarction or – more frequently – bilateral in many pathologic conditions. Restricted diffusion is attributable to infarction, acute hypoxic–ischemic injury, hypoglycemia, Leigh disease, encephalitis and CJD. Contrast enhancement may be seen in cases of infarction and encephalitis. T1-hyperintensity of the lesions is uncommon and may be observed unilaterally in case of hemichorea/hemiballism and bilaterally in acute asphyxia in term newborns, in hypoglycemia, NF1, Fahr disease and manganese intoxication. Decreased signal intensity on GRE/T2*-weighted images and/or SWI indicating iron, calcium or hemosiderin depositions is observed in panthotenate kinase-associated neurodegeneration, Parkinson variant of multiple system atrophy, Fahr disease (and other calcifications) as well as with the advancing age. There are a few papers in the literature reviewing basal ganglia lesions. The authors present a more detailed review with rich iconography from the own archive.

  19. Basal hydraulic conditions of Ice Stream B

    Science.gov (United States)

    Engelhardt, Hermann; Kamb, Barclay

    1993-01-01

    Fifteen boreholes have been drilled to the base of Ice Stream B in the vicinity of UpB Camp. The boreholes are spread over an area of about 500 x 1000 m. Several till cores were retrieved from the bottom of the 1000-m-deep holes. Laboratory tests using a simple shear box revealed a yield strength of basal till of 2 kPa. This agrees well with in-situ measurements using a shear vane. Since the average basal shear stress of Ice Stream B with a surface slope of 0.1 degree is about 20 kPa, the ice stream cannot be supported by till that weak. Additional support for this conclusion comes from the basal water pressure that has been measured in all boreholes as soon as the hot water drill reached bottom. In several boreholes, the water pressure has been continuously monitored; in two of them, over several years. The water pressure varies but stays within 1 bar of flotation where ice overburden pressure and water pressure are equal. The ratio of water and overburden pressure lies between 0.986 and 1.002. This is an extremely high value as compared to other fast-moving ice masses; e.g., Variegated Glacier in surge has a ratio of 0.8, and Columbia Glacier - a fast-moving tidewater glacier - has a ratio of 0.9. It implies that water flow under the glacier occurs in a thin film and not in conduits that would drain away water too rapidly. It also implies that basal sliding must be very effective. Water flow under the glacier was measured in a salt-injection experiment where a salt pulse was released at the bottom of a borehole while 60 m down-glacier, the electrical resistance was measured between two other boreholes. A flow velocity of 7 mm/s was obtained.

  20. Assessing Psychological Functioning in Metabolic Disorders: Validation of the Adaptive Behavior Assessment System, Second Edition (ABAS-II), and the Behavior Rating Inventory of Executive Function (BRIEF) for Identification of Individuals at Risk.

    Science.gov (United States)

    Waisbren, Susan E; He, Jianping; McCarter, Robert

    2015-01-01

    Long-term follow-up of neuropsychological functioning in metabolic disorders remains difficult due to limited opportunities for comprehensive neuropsychological evaluations. This study examined the validity of using the Adaptive Behavior Assessment System, Second Edition (ABAS-II), and the Behavior Rating Inventory of Executive Function (BRIEF) for assessing developmental status in metabolic disorders and for identifying individuals at risk for cognitive deficits. Results from individuals with urea cycle disorders, phenylketonuria, galactosemia, and fatty acid oxidation disorders were obtained on the ABAS-II and BRIEF and were compared to results obtained from neuropsychological testing performed on the same day. Correlations between scores on the ABAS-II and developmental or IQ tests for individuals with urea cycle disorders ranged from 0.48 to 0.72 and concordance rates for scores greater than a standard deviation below the normative mean ranged from 69 to 89%. Correlations ranged from 0.20 to 0.68 with concordance ranging from 73 to 90% in the other metabolic disorders. For the BRIEF, correlations with other tests of executive functioning were significant for urea cycle disorders, with concordance ranging from 52 to 80%. For the other metabolic disorders, correlations ranged from -0.09 to -0.55. Concordance rates for at-risk status on the BRIEF and executive functioning tests ranged from 55% in adults to 80% in children with other metabolic disorders. These results indicate that the ABAS-II and BRIEF together can confidently be used as an adjunct or supplementary method for clinical follow-up and for research on functional status involving infants, children, and adults with metabolic disorders.

  1. Metabolic control of resting hemispheric cerebral blood flow is oxidative, not glycolytic.

    Science.gov (United States)

    Powers, William J; Videen, Tom O; Markham, Joanne; Walter, Vonn; Perlmutter, Joel S

    2011-05-01

    Although the close regional coupling of resting cerebral blood flow (CBF) with both cerebral metabolic rate of oxygen (CMRO(2)) and cerebral metabolic rate of glucose (CMRglc) within individuals is well documented, there are few data regarding the coupling between whole brain flow and metabolism among different subjects. To investigate the metabolic control of resting whole brain CBF, we performed multivariate analysis of hemispheric CMRO(2), CMRglc, and other covariates as predictors of resting CBF among 23 normal humans. The univariate analysis showed that only CMRO(2) was a significant predictor of CBF. The final multivariate model contained two additional terms in addition to CMRO(2): arterial oxygen content and oxygen extraction fraction. Notably, arterial plasma glucose concentration and CMRglc were not included in the final model. Our data demonstrate that the metabolic factor controlling hemispheric CBF in the normal resting brain is CMRO(2) and that CMRglc does not make a contribution. Our findings provide evidence for compartmentalization of brain metabolism into a basal component in which CBF is coupled to oxygen metabolism and an activation component in which CBF is controlled by another mechanism.

  2. Refractory epilepsy and basal ganglia: the role of seizure frequency

    Energy Technology Data Exchange (ETDEWEB)

    Bouilleret, V.; Trebossen, R.; Mantzerides, M.; Semah, F.; Ribeiro, M.J. [Service Hospitalier Frederic Joliot, I2BM/DSV, CEA, 91 - Orsay (France); Bouilleret, V. [CHU Bicetre, Unite de Neurophysiologie et d' Epileptologie, AP-HP, 75 - Paris (France); Chassoux, F. [Hopital Saint Anne, Service de Neurochirurgie, 75 - Paris (France); Biraben, A. [CHU, Service de Neurologie, Hopital Pontchaillou, 35 - Rennes (France)

    2008-02-15

    Objectives. - A decrease of [{sup 18}F]Fluoro-L-DOPA uptake in basal ganglia (B.G.) was recently reported in medically refractory epilepsy. The purpose of this study was to assess the involvement of dopaminergic neurotransmission in refractory Temporal Lobe Epilepsy (T.L.E.) and its relationship to glucose metabolism and morphological changes. Methods. - Twelve T.L.E. patients were studied using [{sup 18}F]FDG PET, [{sup 18}F]Fluoro-L-DOPA PET and MRI and compared with healthy control volunteers. Morphological cerebral changes were assessed using Voxel-Based Morphometry (V.B.M.). Student t test statistical maps of functional and morphological differences between patients and controls were obtained using a general linear model. Results. - In T.L.E. patients, [{sup 18}F]Fluoro-L-DOPA uptake was reduced to the same extent in caudate and putamen in both cerebral hemispheres as well as in the substantia nigra (S.N.). These dopaminergic functional alterations occurred without any glucose metabolism changes in these areas. The only mild morphological abnormality was found in striatal regions without any changes in the S.N.. Conclusion. - The present study provides support for dopaminergic neurotransmission involvement in T.L.E.. The discrepancies between G.M.V. atrophy and the pattern of [{sup 18}F]Fluoro-L-DOPA suggest that B.G. involvement is not related to structural subcortical abnormalities. A functional decrease can be ruled out as there was no change of the glycolytic pathway metabolism in these areas. (authors)

  3. Elevated global cerebral blood flow, oxygen extraction fraction and unchanged metabolic rate of oxygen in young adults with end-stage renal disease: an MRI study

    Energy Technology Data Exchange (ETDEWEB)

    Zheng, Gang; Lou, Yaxian; Pan, Zhiying; Liu, Ya [Medical School of Nanjing University, Department of Medical Imaging, Jinling Hospital, Nanjing, Jiangsu (China); Nanjing University of Aeronautics and Astronautics, College of Aivil Aviation, Nanjing, Jiangsu (China); Wen, Jiqiu; Li, Xue; Zhang, Zhe [Medical School of Nanjing University, National Clinical Research Center of Kidney Diseases, Jinling Hospital, Nanjing, Jiangsu (China); Lu, Hanzhang [University of Texas Southwestern Medical Center, Advanced Imaging Research Center, Dallas, TX (United States); Liu, Wei [Siemens Shenzhen Magnetic Resonance Ltd., Shenzhen, Guangdong (China); Liu, Hui [Siemens MR NEA Collaboration, Siemens Ltd., Shanghai (China); Chen, Huijuan; Kong, Xiang; Luo, Song; Jiang, Xiaolu; Zhang, Zongjun; Zhang, Long Jiang; Lu, Guang Ming [Medical School of Nanjing University, Department of Medical Imaging, Jinling Hospital, Nanjing, Jiangsu (China)

    2016-06-15

    To noninvasively assess global cerebral blood flow (CBF), oxygen extraction fraction (OEF) and cerebral metabolic rate of oxygen (CMRO{sub 2}) in young adults with end-stage renal disease (ESRD). Thirty-six patients and 38 healthy volunteers were included and took part in MR examinations, blood and neuropsychological tests. CBF and OEF were measured by phase-contrast and T2-relaxation-under-spin-tagging MRI techniques, respectively. CMRO{sub 2} was computed from CBF, OEF and hematocrit according to Fick's principle. Correlations were performed between MR measurements, blood biochemistry measurements and neuropsychological test scores. Compared with controls, ESRD patients had elevated CBF (72.9 ± 12.5 vs. 63.8 ± 8.5 ml min{sup -1} 100 g{sup -1}, P < 0.001), elevated OEF (47.2 ± 10.2 vs. 35.8 ± 5.4 %, P < 0.001), but unaffected CMRO{sub 2} (199.5 ± 36.4 vs. 193.8 ± 28.6 μmol O{sub 2} min{sup -1} 100 g{sup -1}, P = 0.879). Hematocrit negatively correlated with CBF (r = -0.640, P < 0.001) and OEF (r = -0.701, P < 0.001), but not with CMRO{sub 2}. Altered neuropsychological test scores of ESRD patients were associated with OEF and CBF, but not with CMRO{sub 2}. There were weak relationships between eGFR and hematocrit (r = 0.308, P = 0.068) or CBF (r = 0.318, P = 0.059). Our findings suggested that anaemic young adults with ESRD may afford higher CBF and OEF to maintain a normal CMRO{sub 2}. Despite this compensatory process, however, cognitive function was still impaired and its severity was correlated with their CBF and OEF abnormality. (orig.)

  4. Effects of dumb-bell exercise with and without energy restriction on resting metabolic rate, diet-induced thermogenesis and body composition in mildly obese women.

    Science.gov (United States)

    Matsuo, T; Suzuki, M

    1999-06-01

    The effects of dumb-bell exercise (aerobic-resistance exercise) with and without low calorie diet (LCD) therapy on resting metabolic rate (RMR), diet-induced thermogenesis (DIT) and body composition were studied in 12 mildly obese women aged 19-20 years. The subjects were randomly assigned to one of the following two groups: dumb-bell exercise with LCD (DEx + LCD group), and dumb-bell exercise only (DEx group). The subjects performed dumb-bell exercises with pairs of 2 kg dumb-bells every day after dinner for approximately 20 min. In the DEx + LCD group, subjects also received a liquid-formula diet based on a commercially available diet supplement, Micro Diet, for two of their three daily meals. Thus, they were restricted to approximately 4.18 MJ of energy intake per day for 12 weeks. Subjects underwent several measurement