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Sample records for high muscle mass

  1. High risk of malnutrition is associated with low muscle mass in older hospitalized patients - a prospective cohort study.

    Pierik, Vincent D; Meskers, Carel G M; Van Ancum, Jeanine M; Numans, Siger T; Verlaan, Sjors; Scheerman, Kira; Kruizinga, Roeliene C; Maier, Andrea B

    2017-06-05

    Malnutrition, low muscle strength and muscle mass are highly prevalent in older hospitalized patients and associated with adverse outcomes. Malnutrition may be a risk factor for developing low muscle mass. We aimed to investigate the association between the risk of malnutrition and 1) muscle strength and muscle mass at admission and 2) the change of muscle strength and muscle mass during hospitalization in older patients. The EMPOWER study included 378 patients aged seventy years or older who were acutely or electively admitted to four different wards of an academic teaching hospital in Amsterdam. Patients were grouped into low risk of malnutrition and high risk of malnutrition based on the Short Nutritional Assessment Questionnaire (SNAQ) score and were assessed for hand grip strength and muscle mass using hand held dynamometry respectively bioelectrical impedance analysis (BIA) within 48 h after admission and at day seven, or earlier at the day of discharge. Muscle mass was expressed as skeletal muscle mass, appendicular lean mass, fat free mass and the skeletal muscle index. The mean age of the patients was 79.7 years (SD 6.39), 48.9% were female. At admission, being at high risk of malnutrition was significantly associated with lower muscle mass (Odds Ratio, 95% CI, 0.90, 0.85-0.96), but not with muscle strength. Muscle strength and muscle mass did not change significantly during hospitalization in both groups. In older hospitalized patients, a high risk of malnutrition is associated with lower muscle mass at admission, but not with muscle strength nor with change of either muscle strength or muscle mass during hospitalization.

  2. Low vitamin D and high parathyroid hormone levels as determinants of loss of muscle strength and muscle mass (sarcopenia) : the Longitudinal Aging Study Amsterdam

    Visser, Marjolein; Deeg, Dorly J H; Lips, Paul

    2003-01-01

    The age-related change in hormone concentrations has been hypothesized to play a role in the loss of muscle mass and muscle strength with aging, also called sarcopenia. The aim of this prospective study was to investigate whether low serum 25-hydroxyvitamin D (25-OHD) and high serum PTH

  3. Effects of exercise improves muscle strength and fat mass in patients with high fracture risk: A randomized control trial

    Ding-Cheng Chan

    2018-07-01

    Full Text Available Background: The deterioration of the musculoskeletal system imposes significant impact on physical activity. Exercise is an important strategy which minimizes these changes. It is not clear which type of exercise provides better improvement on low physical performance, low muscle mass and low strength of sarcopenia. We aim to develop an integrated care (IC model and compare its relative efficacy in limb fat free mass, muscle strength, and physical performance with low extremities exercise (LEE in community dwelling older adults with high risk of fractures (Fracture Risk Assessment Tool (FRAX® ≧3% for hip fracture, ≧20% for major osteoporotic fracture or 1-min osteoporosis risk test (≧1 point or fall (≧2 falls in previous year. Methods: Patients were assigned randomized to participate in either IC or LEE group (n = 55 each for 3 months. All participants received education including home-based exercise. The IC group consisted of different modalities of exercise while the LEE group performed machine-based low extremities exercise. Fat free mass, muscle strength, and physical performance were measured at their baseline and 3-months follow-up. Results: Mean age was 73.8 ± 7 years with 69.1% women. Entire cohort demonstrated significant increment in fat free mass, muscle strength (4 indicators and physical performance (3 indicators. However, between group differences were not significant. Conclusion: With regular supervise exercise; both groups are equally effective in decreasing fat mass and increasing physical performance, muscle mass and strength. However, the IC group required fewer resources and thus more financially feasible in a community setting. Keywords: Bone mineral density, Gender differences, Integrated care, Low extremities exercise, Muscle strength

  4. Effects of exercise improves muscle strength and fat mass in patients with high fracture risk: A randomized control trial.

    Chan, Ding-Cheng; Chang, Chirn-Bin; Han, Der-Sheng; Hong, Cian-Hui; Hwang, Jawl-Shan; Tsai, Keh-Sung; Yang, Rong-Sen

    2017-10-26

    The deterioration of the musculoskeletal system imposes significant impact on physical activity. Exercise is an important strategy which minimizes these changes. It is not clear which type of exercise provides better improvement on low physical performance, low muscle mass and low strength of sarcopenia. We aim to develop an integrated care (IC) model and compare its relative efficacy in limb fat free mass, muscle strength, and physical performance with low extremities exercise (LEE) in community dwelling older adults with high risk of fractures (Fracture Risk Assessment Tool (FRAX ® )) ≧3% for hip fracture, ≧20% for major osteoporotic fracture or 1-min osteoporosis risk test (≧1 point) or fall (≧2 falls in previous year). Patients were assigned randomized to participate in either IC or LEE group (n = 55 each) for 3 months. All participants received education including home-based exercise. The IC group consisted of different modalities of exercise while the LEE group performed machine-based low extremities exercise. Fat free mass, muscle strength, and physical performance were measured at their baseline and 3-months follow-up. Mean age was 73.8 ± 7 years with 69.1% women. Entire cohort demonstrated significant increment in fat free mass, muscle strength (4 indicators) and physical performance (3 indicators). However, between group differences were not significant. With regular supervise exercise; both groups are equally effective in decreasing fat mass and increasing physical performance, muscle mass and strength. However, the IC group required fewer resources and thus more financially feasible in a community setting. Copyright © 2017. Published by Elsevier B.V.

  5. Nutritional interventions to preserve skeletal muscle mass

    Backx, Evelien M.P.

    2016-01-01

    Muscle mass is the main predictor for muscle strength and physical function. The amount of muscle mass can decline rapidly during periods of reduced physical activity or during periods of energy intake restriction. For athletes, it is important to maintain muscle mass, since the loss of muscle is

  6. Effects of high-intensity exercise and protein supplement on muscle mass in ADL dependent older people with and without malnutrition: a randomized controlled trial.

    Carlsson, M; Littbrand, H; Gustafson, Y; Lundin-Olsson, L; Lindelöf, N; Rosendahl, E; Håglin, L

    2011-08-01

    Loss of muscle mass is common among old people living in institutions but trials that evaluate interventions aimed at increasing the muscle mass are lacking. Objective, participants and intervention: This randomized controlled trial was performed to evaluate the effect of a high-intensity functional exercise program and a timed protein-enriched drink on muscle mass in 177 people aged 65 to 99 with severe physical or cognitive impairments, and living in residential care facilities. Three-month high-intensity exercise was compared with a control activity and a protein-enriched drink was compared with a placebo drink. A bioelectrical impedance spectrometer (BIS) was used in the evaluation. The amount of muscle mass and body weight (BW) were followed-up at three and six months and analyzed in a 2 x 2 factorial ANCOVA, using the intention to treat principle, and controlling for baseline values. At 3-month follow-up there were no differences in muscle mass and BW between the exercise and the control group or between the protein and the placebo group. No interaction effects were seen between the exercise and nutritional intervention. Long-term negative effects on muscle mass and BW was seen in the exercise group at the 6-month follow-up. A three month high-intensity functional exercise program did not increase the amount of muscle mass and an intake of a protein-enriched drink immediately after the exercise did not induce any additional effect on muscle mass. There were negative long-term effects on muscle mass and BW, indicating that it is probably necessary to compensate for an increased energy demand when offering a high-intensity exercise program.

  7. High insulin-like growth factor-binding protein-1 (IGFBP-1) is associated with low relative muscle mass in older women

    Stilling, Frej; Wallenius, Sara; Michaëlsson, Karl

    2017-01-01

    . In the present study we investigate the association between serum IGFBP-1 and muscle mass. Design Cross-sectional analysis of 4908 women, between 55 and 85 years old, participating in the Swedish Mammography Cohort-Clinical. Methods We defined low relative muscle mass (LRMM) as an appendicular lean mass divided...... relative muscle mass. High IGFBP-1 may be a marker of a catabolic state.......Objective Skeletal muscles serve several important roles in maintaining good health. Insulin-like growth factor-1 (IGF-1) is a promoter of protein synthesis in skeletal muscle. Its binding protein, Insulin-like growth factor-binding protein-1 (IGFBP-1) can be one determinant of IGF-1 activity...

  8. Molecular regulation of high muscle mass in developing Blonde d'Aquitaine cattle foetuses

    Isabelle Cassar-Malek

    2017-10-01

    Full Text Available The Blonde d'Aquitaine (BA is a French cattle breed with enhanced muscularity, partly attributable to a MSTN mutation. The BA m. Semitendinosus has a faster muscle fibre isoform phenotype comprising a higher proportion of fast type IIX fibres compared to age-matched Charolais (CH. To better understand the molecular network of modifications in BA compared to CH muscle, we assayed the transcriptomes of the m. Semitendinosus at 110, 180, 210 and 260 days postconception (dpc. We used a combination of differential expression (DE and regulatory impact factors (RIF to compare and contrast muscle gene expression between the breeds. Prominently developmentally regulated genes in both breeds reflected the replacement of embryonic myosin isoforms (MYL4, MYH3 with adult isoforms (MYH1 and the upregulation of mitochondrial metabolism (CKMT2, AGXT2L1 in preparation for birth. However, the transition to a fast, glycolytic muscle phenotype in the MSTN mutant BA is detectable through downregulation of various slow twitch subunits (TNNC1, MYH7, TPM3, CSRP3 beyond 210 dpc, and a small but consistent genome-wide reduction in mRNA encoding the mitoproteome. Across the breeds, NRIP2 is the regulatory gene possessing a network change most similar to that of MSTN.

  9. Effects of high protein diets on fat-free mass and muscle protein synthesis following weight loss: a randomized controlled trial

    Context: The benefits of high protein diets for sparing lean body mass and sustaining skeletal muscle protein metabolism during short-term weight loss in normal-weight adults are not well described. Objective: Determine the effects of varying levels of dietary protein intake on body compos...

  10. Low Muscle Mass and Breast Cancer Survival

    In a new study, researchers compared the risk of death for women with breast cancer who had low skeletal muscle mass, or sarcopenia, at diagnosis and women who had adequate muscle mass. Learn what they found and what it might mean for patients in this Cancer Currents blog post.

  11. Chronic exercise preserves lean muscle mass in masters athletes.

    Wroblewski, Andrew P; Amati, Francesca; Smiley, Mark A; Goodpaster, Bret; Wright, Vonda

    2011-09-01

    Aging is commonly associated with a loss of muscle mass and strength, resulting in falls, functional decline, and the subjective feeling of weakness. Exercise modulates the morbidities of muscle aging. Most studies, however, have examined muscle-loss changes in sedentary aging adults. This leaves the question of whether the changes that are commonly associated with muscle aging reflect the true physiology of muscle aging or whether they reflect disuse atrophy. This study evaluated whether high levels of chronic exercise prevents the loss of lean muscle mass and strength experienced in sedentary aging adults. A cross-section of 40 high-level recreational athletes ("masters athletes") who were aged 40 to 81 years and trained 4 to 5 times per week underwent tests of health/activity, body composition, quadriceps peak torque (PT), and magnetic resonance imaging of bilateral quadriceps. Mid-thigh muscle area, quadriceps area (QA), subcutaneous adipose tissue, and intramuscular adipose tissue were quantified in magnetic resonance imaging using medical image processing, analysis, and visualization software. One-way analysis of variance was used to examine age group differences. Relationships were evaluated using Spearman correlations. Mid-thigh muscle area (P = 0.31) and lean mass (P = 0.15) did not increase with age and were significantly related to retention of mid-thigh muscle area (P lean mass (P = 0.4) and PT. This study contradicts the common observation that muscle mass and strength decline as a function of aging alone. Instead, these declines may signal the effect of chronic disuse rather than muscle aging. Evaluation of masters athletes removes disuse as a confounding variable in the study of lower-extremity function and loss of lean muscle mass. This maintenance of muscle mass and strength may decrease or eliminate the falls, functional decline, and loss of independence that are commonly seen in aging adults.

  12. Inflammatory markers and loss of muscle mass (sarcopenia) and strength

    Schaap, Laura A; Pluijm, Saskia M F; Deeg, Dorly J H; Visser, Marjolein

    PURPOSE: The objective of this study was to investigate whether high levels of serum interleukin (IL)-6, C-reactive protein (CRP), and alpha1-antichymotrypsin (ACT) were associated with the loss of muscle strength or muscle mass (sarcopenia) in older persons. SUBJECTS: The study included 986 men and

  13. High-frequency resistance training is not more effective than low-frequency resistance training in increasing muscle mass and strength in well-trained men.

    Gomes, Gederson K; Franco, Cristiane M; Nunes, Paulo Ricardo P; Orsatti, Fábio L

    2018-02-27

    We studied the effects of two different weekly frequency resistance training (RT) protocols over eight weeks on muscle strength and muscle hypertrophy in well-trained men. Twenty-three subjects (age: 26.2±4.2 years; RT experience: 6.9±3.1 years) were randomly allocated into the two groups: low frequency (LFRT, n = 12) or high frequency (HFRT, n = 11). The LFRT performed a split-body routine, training each specific muscle group once a week. The HFRT performed a total-body routine, training all muscle groups every session. Both groups performed the same number of sets (10-15 sets) and exercises (1-2 exercise) per week, 8-12 repetitions maximum (70-80% of 1RM), five times per week. Muscle strength (bench press and squat 1RM) and lean tissue mass (dual-energy x-ray absorptiometry) were assessed prior to and at the end of the study. Results showed that both groups improved (ptrained subjects when the sets and intensity are equated per week.

  14. Regulation of skeletal muscle oxidative capacity and muscle mass by SIRT3.

    Ligen Lin

    Full Text Available We have previously reported that the expression of mitochondrial deacetylase SIRT3 is high in the slow oxidative muscle and that the expression of muscle SIRT3 level is increased by dietary restriction or exercise training. To explore the function of SIRT3 in skeletal muscle, we report here the establishment of a transgenic mouse model with muscle-specific expression of the murine SIRT3 short isoform (SIRT3M3. Calorimetry study revealed that the transgenic mice had increased energy expenditure and lower respiratory exchange rate (RER, indicating a shift towards lipid oxidation for fuel usage, compared to control mice. The transgenic mice exhibited better exercise performance on treadmills, running 45% further than control animals. Moreover, the transgenic mice displayed higher proportion of slow oxidative muscle fibers, with increased muscle AMPK activation and PPARδ expression, both of which are known regulators promoting type I muscle fiber specification. Surprisingly, transgenic expression of SIRT3M3 reduced muscle mass up to 30%, likely through an up-regulation of FOXO1 transcription factor and its downstream atrophy gene MuRF-1. In summary, these results suggest that SIRT3 regulates the formation of oxidative muscle fiber, improves muscle metabolic function, and reduces muscle mass, changes that mimic the effects of caloric restriction.

  15. TAK1 regulates skeletal muscle mass and mitochondrial function

    Hindi, Sajedah M.; Sato, Shuichi; Xiong, Guangyan; Bohnert, Kyle R.; Gibb, Andrew A.; Gallot, Yann S.; McMillan, Joseph D.; Hill, Bradford G.

    2018-01-01

    Skeletal muscle mass is regulated by a complex array of signaling pathways. TGF-β–activated kinase 1 (TAK1) is an important signaling protein, which regulates context-dependent activation of multiple intracellular pathways. However, the role of TAK1 in the regulation of skeletal muscle mass remains unknown. Here, we report that inducible inactivation of TAK1 causes severe muscle wasting, leading to kyphosis, in both young and adult mice.. Inactivation of TAK1 inhibits protein synthesis and induces proteolysis, potentially through upregulating the activity of the ubiquitin-proteasome system and autophagy. Phosphorylation and enzymatic activity of AMPK are increased, whereas levels of phosphorylated mTOR and p38 MAPK are diminished upon inducible inactivation of TAK1 in skeletal muscle. In addition, targeted inactivation of TAK1 leads to the accumulation of dysfunctional mitochondria and oxidative stress in skeletal muscle of adult mice. Inhibition of TAK1 does not attenuate denervation-induced muscle wasting in adult mice. Finally, TAK1 activity is highly upregulated during overload-induced skeletal muscle growth, and inactivation of TAK1 prevents myofiber hypertrophy in response to functional overload. Overall, our study demonstrates that TAK1 is a key regulator of skeletal muscle mass and oxidative metabolism. PMID:29415881

  16. A high whey protein-, leucine-, and vitamin D-enriched supplement preserves muscle mass during intentional weight loss in obese older adults: a double-blind randomized controlled trial

    Verreijen, A.M.; Verlaan, S.; Engberink, M.F.; Swinkels, S.; Bosch, J.; Weijs, P.J.M.

    2015-01-01

    Background: Intentional weight loss in obese older adults is a risk factor for muscle loss and sarcopenia. Objective: The objective was to examine the effect of a high whey protein-, leucine-, and vitamin D-enriched supplement on muscle mass preservation during intentional weight loss in obese older

  17. Exposure to internal muscle tissue loads under the ischial tuberosities during sitting is elevated at abnormally high or low body mass indices.

    Sopher, Ran; Nixon, Jane; Gorecki, Claudia; Gefen, Amit

    2010-01-19

    Deep tissue injury (DTI) is a severe pressure ulcer characteristic of chairfast or bedfast individuals, such as those with impaired mobility or neurological disorders. A DTI differs from superficial pressure ulcers in that the onset of DTI occurs under intact skin, in skeletal muscle tissue overlying bony prominences, and progression of the wound continues subcutaneously until skin breakdown. Due to the nature of this silently progressing wound, it is highly important to screen potentially susceptible individuals for their risk of developing a DTI. Abnormally low and high values of the body mass index (BMI) have been proposed to be associated with pressure ulcers, but a clear mechanism is lacking. We hypothesize that during sitting, exposure to internal muscle tissue loads under the ischial tuberosities (IT) is elevated at abnormally high or low body mass indices. Our aims in this study were: (a) to develop biomechanical models of the IT region in the buttocks that represent an individual who is gaining or losing weight drastically. (b) To determine changes in internal tissue load measures: principal compression strain, strain energy density (SED), principal compression stress and von Mises stress versus the BMI. (c) To determine percentage volumes of muscle tissue exposed to critical levels of the above load measures, which were defined based on our previous animal and tissue engineered model experiments: strain>or=50%, stress>or=2 kPa, SED>or=0.5 kPa. A set of 21 finite element models, which represented the same individual, but with different BMI values within the normal range, above it and below it, was solved for the outcome measures listed above. The models had the same IT shape, size, distance between the IT, and (non-linear) mechanical properties for all soft tissues, but different thicknesses of gluteus muscles and fat tissue layers, corresponding to the BMI level. The resulted data indicated a trend of progressive increase in internal tissue loading

  18. Muscle strength rather than muscle mass is associated with osteoporosis in older Chinese adults

    Yixuan Ma

    2018-02-01

    Conclusion: Based on our study, muscle strength rather than muscle mass is negatively associated with OS in older people; thus, we should pay more attention to muscle strength training in the early stage of the OS.

  19. Muscle Mass and Weight Gain Nutritional Supplements

    Campbell, Bill

    There are numerous sports supplements available that claim to increase lean body mass. However, for these sports supplements to exert any favorable changes in lean body mass, they must influence those factors regulating skeletal muscle hypertrophy (i.e., satellite cell activity, gene transcription, protein translation). If a given sports supplement does favorably influence one of these regulatory factors, the result is a positive net protein balance (in which protein synthesis exceeds protein breakdown). Sports supplement categories aimed at eliciting a positive net protein balance include anabolic hormone enhancers, nutrient timing pre- and postexercise workout supplements, anticatabolic supplements, and nitric oxide boosters. Of all the sports supplements available, only a few have been subject to multiple clinical trials with repeated favorable outcomes relative to increasing lean body mass. This chapter focuses on these supplements and others that have a sound theoretical rationale in relation to increasing lean body mass.

  20. Integrated expression analysis of muscle hypertrophy identifies Asb2 as a negative regulator of muscle mass

    Davey, Jonathan R.; Watt, Kevin I.; Parker, Benjamin L.; Chaudhuri, Rima; Ryall, James G.; Cunningham, Louise; Qian, Hongwei; Sartorelli, Vittorio; Chamberlain, Jeffrey; James, David E.

    2016-01-01

    The transforming growth factor-β (TGF-β) signaling network is a critical regulator of skeletal muscle mass and function and, thus, is an attractive therapeutic target for combating muscle disease, but the underlying mechanisms of action remain undetermined. We report that follistatin-based interventions (which modulate TGF-β network activity) can promote muscle hypertrophy that ameliorates aging-associated muscle wasting. However, the muscles of old sarcopenic mice demonstrate reduced response to follistatin compared with healthy young-adult musculature. Quantitative proteomic and transcriptomic analyses of young-adult muscles identified a transcription/translation signature elicited by follistatin exposure, which included repression of ankyrin repeat and SOCS box protein 2 (Asb2). Increasing expression of ASB2 reduced muscle mass, thereby demonstrating that Asb2 is a TGF-β network–responsive negative regulator of muscle mass. In contrast to young-adult muscles, sarcopenic muscles do not exhibit reduced ASB2 abundance with follistatin exposure. Moreover, preventing repression of ASB2 in young-adult muscles diminished follistatin-induced muscle hypertrophy. These findings provide insight into the program of transcription and translation events governing follistatin-mediated adaptation of skeletal muscle attributes and identify Asb2 as a regulator of muscle mass implicated in the potential mechanistic dysfunction between follistatin-mediated muscle growth in young and old muscles. PMID:27182554

  1. The Regulation of Muscle Mass by Endogenous Glucocorticoids

    Daniel L Marks

    2015-02-01

    Full Text Available Glucocorticoids are highly conserved fundamental regulators of energy homeostasis. In response to stress in the form of perceived danger or acute inflammation, glucocorticoids are released from the adrenal gland, rapidly mobilizing energy from carbohydrate, fat and protein stores. In the case of inflammation, mobilized protein is critical for the rapid synthesis of acute phase reactants and an efficient immune response to infection. While adaptive in response to infection, chronic mobilization can lead to a p rofound depletion of energy stores. Skeletal muscle represents the major body store of protein, and can become substantially atrophied under conditions of chronic inflammation. Glucocorticoids elicit the atrophy of muscle by increasing the rate of protein degradation by the ubiquitin-proteasome system and autophagy lysosome system. Protein synthesis is also suppressed at the level of translational initiation, preventing the production of new myofibrillar protein. Glucocorticoids also antagonize the action of anabolic regulators such as insulin further exacerbating the loss of protein and muscle mass. The loss of muscle mass in the context of chronic disease is a key feature of cachexia and contributes substantially to morbidity and mortality. A growing body of evidence demonstrates that glucocorticoid signaling is a common mediator of wasting, irrespective of the underlying initiator or disease state. This review will highlight fundamental mechanisms of glucocorticoid signaling and detail the mechanisms of glucocorticoid-induced muscle atrophy. Additionally, the evidence for glucocorticoids as a driver of muscle wasting in numerous disease states will be discussed. Given the burden of wasting diseases and the nodal nature of glucocorticoid signaling, effective anti-glucocorticoid therapy would be a valuable clinical tool. Therefore, the progress and potential pitfalls in the development of glucocorticoid antagonists for muscle wasting will

  2. High-frequency, low-intensity vibrations increase bone mass and muscle strength in upper limbs, improving autonomy in disabled children.

    Reyes, M Loreto; Hernández, Marta; Holmgren, Luz J; Sanhueza, Enrique; Escobar, Raúl G

    2011-08-01

    Disuse osteoporosis in children is a progressive disease that can affect quality of life. High-frequency, low-magnitude vibration (HFLMV) acts as an anabolic signal for bone and muscle. We undertook a prospective, randomized, double-blind, placebo-controlled clinical trial to assess the efficacy and safety of regional HFLMV in disabled children. Sixty-five children 6 to 9 year of age were randomized into three groups: placebo, 60 Hz, and 90 Hz. In the two active groups, a 0.3-g mechanical vibration was delivered to the radii and femurs for 5 minutes each day. After 6 months, the main endpoint was bone mineral density (BMD) at the ultradistal radius (UDR), 33% radii (33%R), and femoral necks (FN). Secondary endpoints were area and bone mineral content (BMC) at the UDR, 33%R, and FN; grip force of the upper and lower limbs; motor function; and PedsQL evaluation. An intention-to-treat analysis was used. Fifty-seven children (88%) completed the protocol. A significant increase was observed in the 60-Hz group relative to the other groups in BMD at the UDR (p = .011), in grip force of the upper limbs (p = .035), and in the "daily activities item" (p = .035). A mixed model to evaluate the response to intervention showed a stronger effect of 60 Hz on patients with cerebral palsy on the UDR and that between-subject variability significantly affected the response. There were no reported side effects of the intervention. This work provides evidence that regional HFLMV is an effective and safe strategy to improve bone mass, muscle strength, and possibly independence in children with motor disabilities. Copyright © 2011 American Society for Bone and Mineral Research.

  3. Muscle Strength and Muscle Mass in Older Patients during Hospitalization: The EMPOWER Study

    Van Ancum, Jeanine M.; Scheerman, Kira; Pierik, Vincent D.; Numans, Siger T.; Verlaan, Sjors; Smeenk, Hanne E.; Slee-Valentijn, Monique; Kruizinga, Roeliene C.; Meskers, Carel G.M.; Maier, Andrea B.

    2017-01-01

    Background Low muscle strength and muscle mass are associated with an increased length of hospital stay and higher mortality rate in inpatients. To what extent hospitalization affects muscle strength and muscle mass is unclear. Objective We aimed to assess muscle strength and muscle mass at admission and during hospitalization in older patients and its relation with being at risk of geriatric conditions. Methods The EMPOWER study included patients aged 70 years and older, admitted to 4 wards of the VU University Medical Center in the Netherlands between April and December 2015. At admission, patients were screened for being at risk of 4 geriatric conditions: delirium, falls, malnutrition, and functional disability. At admission and at discharge, muscle strength and muscle mass were assessed. Results A total of 373 patients (mean age, standard deviation [SD]: 79.6, 6.38 years) were included at admission, and 224 patients (mean age, SD: 80.1, 6.32 years) at discharge. At admission, lower muscle strength in both female and male patients and low muscle mass in male patients were associated with being at risk of a higher cumulative number of geriatric conditions. Muscle strength increased during hospitalization, but no change in muscle mass was observed. Changes in muscle measures were not associated with being at risk of geriatric conditions. Discussion Older patients with lower muscle strength and muscle mass at admission were at risk of a higher cumulative number of geriatric conditions. However, being at risk of geriatric conditions did not forecast further decrease in muscle strength and muscle mass during hospitalization PMID:28817825

  4. [Simultaneous determination of 7 arsenic species in chicken muscle and chicken liver with high performance liquid chromatography-inductively coupled plasma mass spectrometry].

    Yang, Lijun; Hu, Qiaoru; Guo, Wei; Liu, Yumin; Song, Xiaohua; Zhang, Pengcheng

    2011-05-01

    A method for the simultaneous determination of 7 arsenic species was developed with high performance liquid chromatography and inductively coupled plasma mass spectrometry (HPLC-ICP-MS). The sample was extracted with artificial gastric juice. The HPLC separation was performed on an anion analytical column utilizing a gradient elution program of ammonium carbonate and water as the mobile phase. Identification and quantification were achieved by ICP-MS. Good linearities of 7 arsenic species were observed in the range from 1 microg/kg to 50 microg/kg with the correlation coefficients greater than 0.999. The average recoveries of 7 arsenic species spiked at the three levels of 1, 2 and 10 microg/kg ranged from 84.3% to 106.6% with the relative standard deviations of 1.4%-4.2%. The quantification limits of 7 arsenic species were 1 microg/kg. The method was proved to be good reproducibility, high sensitivity and simple preprocessing. This method is suitable for the simultaneous determination of 7 arsenic species in chicken muscle and chicken liver.

  5. CORRELATIONS BETWEEN MUSCLE MASS, MUSCLE STRENGTH, PHYSICAL PERFORMANCE, AND MUSCLE FATIGUE RESISTANCE IN COMMUNITY-DWELLING ELDERLY SUBJECTS

    Elizabeth

    2016-03-01

    Full Text Available Objective: To determine the correlations between muscle mass, muscle strength, physical performance, and muscle fatigue resistance in community-dwelling elderly people in order to elucidate factors which contribute to elderly’s performance of daily activities. Methods: A cross-sectional study was conducted on community-dwelling elderly in Bandung from September to December 2014. One hundred and thirty elderly, 60 years old or above, were evaluated using bioelectrical impedance analysis to measure muscle mass; grip strength to measure muscle strength and muscle fatigue resistance; habitual gait speed to measure physical performance; and Global Physical Activity Questionnaire (GPAQ to assess physical activity. Results: There were significant positive correlations between muscle mass (r=0,27, p=0,0019, muscle strength (r=0,26, p=0,0024, and physical performance (r=0,32, p=0,0002 with muscle fatigue resistance. Physical performance has the highest correlation based on multiple regression test (p=0,0025. In association with muscle mass, the physical activity showed a significant positive correlation (r=0,42, p=0,0000. Sarcopenia was identified in 19 (14.61% of 130 subjects. Conclusions: It is suggested that muscle mass, muscle strength, and physical performance influence muscle fatigue resistance.

  6. Supplemental protein in support of muscle mass and health: advantage whey.

    Devries, Michaela C; Phillips, Stuart M

    2015-03-01

    Skeletal muscle is an integral body tissue playing key roles in strength, performance, physical function, and metabolic regulation. It is essential for athletes to ensure that they have optimal amounts of muscle mass to ensure peak performance in their given sport. However, the role of maintaining muscle mass during weight loss and as we age is an emerging concept, having implications in chronic disease prevention, functional capacity, and quality of life. Higher-protein diets have been shown to: (1) promote gains in muscle mass, especially when paired with resistance training; (2) spare muscle mass loss during caloric restriction; and (3) attenuate the natural loss of muscle mass that accompanies aging. Protein quality is important to the gain and maintenance of muscle mass. Protein quality is a function of protein digestibility, amino acid content, and the resulting amino acid availability to support metabolic function. Whey protein is one of the highest-quality proteins given its amino acid content (high essential, branched-chain, and leucine amino acid content) and rapid digestibility. Consumption of whey protein has a robust ability to stimulate muscle protein synthesis. In fact, whey protein has been found to stimulate muscle protein synthesis to a greater degree than other proteins such as casein and soy. This review examines the existing data supporting the role for protein consumption, with an emphasis on whey protein, in the regulation of muscle mass and body composition in response to resistance training, caloric restriction, and aging. © 2015 Institute of Food Technologists®

  7. Ultra-high performance liquid chromatography-tandem mass spectrometry in high-throughput confirmation and quantification of 34 anabolic steroids in bovine muscle.

    Vanhaecke, Lynn; Vanden Bussche, Julie; Wille, Klaas; Bekaert, Karen; De Brabander, Hubert F

    2011-08-26

    An ultra-high performance liquid chromatography tandem mass spectrometry multi-residue method for the determination of 34 anabolic steroids (10 estrogens including stilbenes, 14 androgens and 10 gestagens) in meat of bovine origin is reported. The extraction and clean-up procedure involved homogenization with methanol, defatting with hexane, liquid/liquid extraction with diethylether and finally SPE clean-up with coupled Si and NH(2) cartridges. The analytes were separated on a 1.9 μm Hypersil Gold column (100×2.1 mm) and quantified on a triple quadrupole mass spectrometer (TSQ Vantage) operating simultaneously in both positive and negative atmospheric pressure chemical ionisation (APCI) modes. This analytical procedure was subsequently validated according to EU criteria (CD 2002/657/EC), resulting in decision limits and detection capabilities ranging between 0.04 and 0.88 μg kg(-1) and 0.12 and 1.9 μg kg(-1), respectively. The method obtained for all, natural and synthetic steroids, adequate precisions and intra-laboratory reproducibilities (relative standard deviation below 20%), and the linearity ranged between 0.991 and 0.999. The performance characteristics fulfill the recommended concentrations fixed by the Community Reference Laboratories. The developed analysis is sensitive, and robust and therefore useful for confirmation and quantification of anabolic steroids for research purposes and residue control programs. Copyright © 2010 Elsevier B.V. All rights reserved.

  8. Effect of transcutaneous electrical muscle stimulation on postoperative muscle mass and protein synthesis

    Vinge, O; Edvardsen, L; Jensen, F

    1996-01-01

    In an experimental study, 13 patients undergoing major elective abdominal surgery were given postoperative transcutaneous electrical muscle stimulation (TEMS) to the quadriceps femoris muscle on one leg; the opposite leg served as control. Changes in cross-sectional area (CSA) and muscle protein ...... protein synthesis and muscle mass after abdominal surgery and should be evaluated in other catabolic states with muscle wasting.......In an experimental study, 13 patients undergoing major elective abdominal surgery were given postoperative transcutaneous electrical muscle stimulation (TEMS) to the quadriceps femoris muscle on one leg; the opposite leg served as control. Changes in cross-sectional area (CSA) and muscle protein...... synthesis were assessed by computed tomography and ribosome analysis of percutaneous muscle biopsies before surgery and on the sixth postoperative day. The percentage of polyribosomes in the ribosome suspension decreased significantly (P

  9. Novel biomarkers of changes in muscle mass or muscle pathology

    Arvanitidis, Athanasios

    healthy individuals and patients with different myopathy diseases, describe the underlying mechanisms of muscle conditions and possibly putative response to an intervention. There were three different studies where biomarkers were applied in this thesis. Study I involved 51 myositis patients (28...

  10. Counteracting age-related loss of skeletal muscle mass

    Bechshøft, Rasmus; Reitelseder, Søren; Højfeldt, Grith

    2016-01-01

    Background Aging is associated with decreased muscle mass and functional capacity, which in turn decrease quality of life. The number of citizens over the age of 65 years in the Western world will increase by 50 % over the next four decades, and this demographic shift brings forth new challenges...... at both societal and individual levels. Only a few longitudinal studies have been reported, but whey protein supplementation seems to improve muscle mass and function, and its combination with heavy strength training appears even more effective. However, heavy resistance training may reduce adherence...... Intervention Study will generate scientific evidence and recommendations to counteract age-related loss of skeletal muscle mass in elderly individuals....

  11. Association between muscle mass and a single measurement of ...

    cause mortality significantly. It is strongly associated with the risk of heart attack, coronary artery disease, cardiovascular disease, stroke and liver disease. The relationship between muscle mass and a diagnosis of hypertension in a sample of ...

  12. High-throughput and simultaneous analysis of eight central-acting muscle relaxants in human plasma by ultra-performance liquid chromatography-tandem mass spectrometry in the positive and negative ionization modes.

    Ogawa, Tadashi; Hattori, Hideki; Kaneko, Rina; Ito, Kenjiro; Iwai, Masae; Mizutani, Yoko; Arinobu, Tetsuya; Ishii, Akira; Seno, Hiroshi

    2011-06-01

    In this report, a high-throughput and sensitive method for analysis of eight central-acting muscle relaxants in human plasma by ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) in the positive and negative ionization modes using tolbutamide as internal standard is presented. After pretreatment of a plasma sample by solid-phase extraction with an Oasis HLB cartridge, muscle relaxants were analyzed by UPLC with Acquity UPLC BEH C(18) column and Acquity TQD tandem quadrupole mass spectrometer equipped with an electrospray ionization interface. The calibration curves for muscle relaxants spiked into human plasma equally showed good linearities in the nanogram per milliliter order range. The detection limits (signal-to-noise ratio = 3) was as low as 0.1-2 ng/mL. The method gave satisfactory recovery rates, accuracy, and precision for quality control samples spiked with muscle relaxants. To further validate the present method, 250 mg of chlorphenesin carbamate was orally administered to a healthy male volunteer, and the concentrations of chlorphenesin carbamate in plasma were measured 0.5, 1, 2, 4, 6, and 8 h after dosing; their concentrations in human plasma were between 0.62 and 2.44 μg/mL. To our knowledge, this is the first report describing simultaneous analysis of over more than two central-acting muscle relaxants by liquid chromatography-tandem mass spectrometry. This has been realized by the capability of our instrument for simultaneous multiple reaction monitoring of the target compounds in both positive and negative ionization modes. Therefore, the present method seems very useful in forensic and clinical toxicology and pharmacokinetic studies.

  13. Myostatin inhibition in muscle, but not adipose tissue, decreases fat mass and improves insulin sensitivity.

    Tingqing Guo

    Full Text Available Myostatin (Mstn is a secreted growth factor expressed in skeletal muscle and adipose tissue that negatively regulates skeletal muscle mass. Mstn(-/- mice have a dramatic increase in muscle mass, reduction in fat mass, and resistance to diet-induced and genetic obesity. To determine how Mstn deletion causes reduced adiposity and resistance to obesity, we analyzed substrate utilization and insulin sensitivity in Mstn(-/- mice fed a standard chow. Despite reduced lipid oxidation in skeletal muscle, Mstn(-/- mice had no change in the rate of whole body lipid oxidation. In contrast, Mstn(-/- mice had increased glucose utilization and insulin sensitivity as measured by indirect calorimetry, glucose and insulin tolerance tests, and hyperinsulinemic-euglycemic clamp. To determine whether these metabolic effects were due primarily to the loss of myostatin signaling in muscle or adipose tissue, we compared two transgenic mouse lines carrying a dominant negative activin IIB receptor expressed specifically in adipocytes or skeletal muscle. We found that inhibition of myostatin signaling in adipose tissue had no effect on body composition, weight gain, or glucose and insulin tolerance in mice fed a standard diet or a high-fat diet. In contrast, inhibition of myostatin signaling in skeletal muscle, like Mstn deletion, resulted in increased lean mass, decreased fat mass, improved glucose metabolism on standard and high-fat diets, and resistance to diet-induced obesity. Our results demonstrate that Mstn(-/- mice have an increase in insulin sensitivity and glucose uptake, and that the reduction in adipose tissue mass in Mstn(-/- mice is an indirect result of metabolic changes in skeletal muscle. These data suggest that increasing muscle mass by administration of myostatin antagonists may be a promising therapeutic target for treating patients with obesity or diabetes.

  14. Relation between body mass index percentile and muscle strength ...

    Relation between body mass index percentile and muscle strength and endurance. ... Egyptian Journal of Medical Human Genetics ... They were divided into three groups according to their body mass index percentile where group (a) is equal to or more than 5% percentile yet less than 85% percentile, group (b) is equal to ...

  15. Prevalence of skeletal muscle mass loss and its association with swallowing function after cardiovascular surgery.

    Wakabayashi, Hidetaka; Takahashi, Rimiko; Watanabe, Naoko; Oritsu, Hideyuki; Shimizu, Yoshitaka

    2017-06-01

    The aim of this study was to assess the prevalence of skeletal muscle mass loss and its association with swallowing function in patients with dysphagia after cardiovascular surgery. A retrospective cohort study was performed in 65 consecutive patients with dysphagia after cardiovascular surgery who were prescribed speech therapy. Skeletal muscle index (SMI) was calculated as total psoas muscle area assessed via abdominal computed tomography divided by height squared. Cutoff values were 6.36 cm 2 /m 2 for men and 3.92 cm 2 /m 2 for women. The Food Intake Level Scale (FILS) was used to assess the swallowing function. Univariate and ordered logistic regression analyses were applied to examine the associations between skeletal muscle mass loss and dysphagia. The study included 50 men and 15 women (mean age 73 ± 8 y). The mean SMI was 4.72 ± 1.37 cm 2 /m 2 in men and 3.33 ± 1.42 cm 2 /m 2 in women. Skeletal muscle mass loss was found in 53 (82%) patients. Twelve had tracheostomy cannula. Thirteen were non-oral feeding (FILS levels 1-3), 5 were oral food intake and alternative nutrition (levels 4-6), and 47 were oral food intake alone (levels 7-9) at discharge. The FILS at discharge was significantly lower in patients with skeletal muscle mass loss. Ordered logistic regression analysis of swallowing function showed that skeletal muscle mass loss and tracheostomy cannula were associated independently with the FILS at discharge. The prevalence of skeletal muscle mass loss is very high, and skeletal muscle mass loss is associated with swallowing function. Copyright © 2017 Elsevier Inc. All rights reserved.

  16. Correlation between Body Mass Index, Gender, and Skeletal Muscle Mass Cut off Point in Bandung

    Richi Hendrik Wattimena; Vitriana; Irma Ruslina Defi

    2017-01-01

    Objective: To determine the average skeletal muscle mass (SMM) value in young adults as a reference population; to analyze the correlation of gender, and body mass index to the cut off point; and to determine skeletal muscle mass cut off points of population in Bandung, Indonesia. Methods: This was a cross-sectional study involving 199 participants, 122 females and 77 males. The sampling technique used was the multistage random sampling. The participants were those who lived in four ma...

  17. [Variation of muscle mass and weight in critical patient].

    Valls-Matarín, J; del Cotillo-Fuente, M; Grané-Mascarell, N; Quintana, S

    2015-01-01

    Quantify the muscle mass and body weight variation in critically ill patients and to identify associated factors. A descriptive follow-up study. Data for demographic variables, body weight, fluid balance, daily kilocalories, the amount of sedation and muscle relaxants received and motor physiotherapy applied were collected. Three consecutive measurements were performed in the brachial biceps and quadriceps rectus by using ultrasound, upon admission and every 5 days until discharge. 68 patients were included. Average age was of 73.5 [57-78,5] years. The median length of stay was 9.5 [5.5 -15] days. The median 16 (SD=5.7) daily kilocalories per kg/weight, 91.2% received sedation, 44.1% received muscle relaxants and 20% received physiotherapy. The patients presented a muscle wasting of 4.9 (SD=3.9)mm, p <.001 in the brachial biceps and 5.6 (SD=4.8)mm, p <.001 in the quadriceps rectus. Regression analysis selected the length of stay and the muscle relaxants are the most influential variables in the brachial biceps muscle wasting (R2=0.4), and length of stay as the most influential in the quadriceps rectus muscle wasting (R2=0.3). Patient's mean body weight on admission was of 81.1 (SD=15)kg and 81.2 (SD=14.2)kg on discharge, p=.95. The critically ill patient presents a significant muscle waste related with the length of stay and the treatment received with muscle relaxants. Patients are being discharged with a similar body weight to which they were admitted but with a significant reduction of muscle mass. Copyright © 2014 Elsevier España, S.L.U. y SEEIUC. All rights reserved.

  18. Myoglobin plasma level related to muscle mass and fiber composition: a clinical marker of muscle wasting?

    Weber, Marc-André; Kinscherf, Ralf; Krakowski-Roosen, Holger; Aulmann, Michael; Renk, Hanna; Künkele, Annette; Edler, Lutz; Kauczor, Hans-Ulrich; Hildebrandt, Wulf

    2007-08-01

    Progressive muscle wasting is a central feature of cancer-related cachexia and has been recognized as a determinant of poor prognosis and quality of life. However, until now, no easily assessable clinical marker exists that allows to predict or to track muscle wasting. The present study evaluated the potential of myoglobin (MG) plasma levels to indicate wasting of large locomotor muscles and, moreover, to reflect the loss of MG-rich fiber types, which are most relevant for daily performance. In 17 cancer-cachectic patients (weight loss 22%) and 27 age- and gender-matched healthy controls, we determined plasma levels of MG and creatine kinase (CK), maximal quadriceps muscle cross-sectional area (CSA) by magnetic resonance imaging, muscle morphology and fiber composition in biopsies from the vastus lateralis muscle, body cell mass (BCM) by impedance technique as well as maximal oxygen uptake (VO(2)max). In cachectic patients, plasma MG, muscle CSA, BCM, and VO(2)max were 30-35% below control levels. MG showed a significant positive correlation to total muscle CSA (r = 0.65, p max as an important functional readout. CK plasma levels appear to be less reliable because prolonged increases are observed in even subclinical myopathies or after exercise. Notably, cancer-related muscle wasting was not associated with increases in plasma MG or CK in this study.

  19. Muscle hypertrophy: a narrative review on training principles for increasing muscle mass

    Howe, Louis; Read, Paul; Waldron, Mark

    2017-01-01

    Developing muscle cross-sectional area has the potential to enhance performance for many athletes. Because emerging evidence challenges traditional beliefs regarding the prescription of hypertrophy-focused training programs, this review provides an overview of the current literature relating, specifically, to programming variables. Evidence-based recommendations are provided for the design of effective resistance-training programs, with the goal of increasing an athlete's skeletal muscle mass.

  20. Relative Skeletal Muscle Mass Is Associated with Development of Metabolic Syndrome

    Byung Sam Park

    2013-12-01

    Full Text Available BackgroundVisceral adiposity is related to insulin resistance. Skeletal muscle plays a central role in insulin-mediated glucose disposal; however, little is known about the association between muscle mass and metabolic syndrome (MS. This study is to clarify the clinical role of skeletal muscle mass in development of MS.MethodsA total of 1,042 subjects were enrolled. Subjects with prior MS and chronic diseases were excluded. After 24 months, development of MS was assessed using NCEP-ATP III criteria. Skeletal muscle mass (SMM; kg, body fat mass (BFM; kg, and visceral fat area (VFA; cm2 were obtained from bioelectrical analysis. Then, the following values were calculated as follows: percent of SMM (SMM%; %: SMM (kg/weight (kg, skeletal muscle index (SMI; kg/m2: SMM (kg/height (m2, skeletal muscle to body fat ratio (MFR: SMM (kg/BFM (kg, and skeletal muscle to visceral fat ratio (SVR; kg/cm2: SMM (kg/VFA (cm2.ResultsAmong 838 subjects, 88 (10.5% were newly diagnosed with MS. Development of MS increased according to increasing quintiles of BMI, SMM, VFA, and SMI, but was negatively associated with SMM%, MFR, and SVR. VFA was positively associated with high waist circumference (WC, high blood pressure (BP, dysglycemia, and high triglyceride (TG. In contrast, MFR was negatively associated with high WC, high BP, dysglycemia, and high TG. SVR was negatively associated with all components of MS.ConclusionRelative SMM ratio to body composition, rather than absolute mass, may play a critical role in development of MS and could be used as a strong predictor.

  1. Tinetti mobility test is related to muscle mass and strength in non-institutionalized elderly people.

    Curcio, Francesco; Basile, Claudia; Liguori, Ilaria; Della-Morte, David; Gargiulo, Gaetano; Galizia, Gianluigi; Testa, Gianluca; Langellotto, Assunta; Cacciatore, Francesco; Bonaduce, Domenico; Abete, Pasquale

    2016-12-01

    Elderly people are characterized by a high prevalence of falls and sarcopenia. However, the relationship among Tinetti mobility test (TMT) score, a powerful tool to detect elderly people at risk of falls, and sarcopenia is still not thoroughly investigated. Thus, to determine the relationship between TMT score and muscle mass and strength, 337 elderly participants (mean age 77.1 ± 6.9 years) admitted to comprehensive geriatric assessment were enrolled. TMT score, muscle mass by bioimpedentiometer, and muscle strength by grip strength were evaluated. Muscle mass progressively decreased as TMT score decreased (from 15.3 ± 3.7 to 8.8 ± 1.8 kg/m 2 ; p for trend strength decreased progressively as Tinetti score decreased (from 34.7 ± 8.0 to 23.7 ± 8.7 kg; p for trend 0.001). Linear regression analysis demonstrated that TMT score is linearly related with muscle mass (y = 4.5x + 0.4, r = 0.61; p strength (y = 14.0x + 0.8, r = 0.53; p strength (r = 0.39, p = 0.046). The present study indicates that TMT score is significantly related to muscle mass and strength in non-institutionalized elderly participants. This evidence suggests that TMT score, together with evaluation of muscle mass and strength, may identify sarcopenic elderly participants at high risk of falls.

  2. Development of a new screening method for the detection of antibiotic residues in muscle tissues using liquid chromatography and high resolution mass spectrometry with a LC-LTQ-Orbitrap instrument.

    Hurtaud-Pessel, D; Jagadeshwar-Reddy, T; Verdon, E

    2011-10-01

    A liquid chromatography-high resolution mass spectrometry (LC-HRMS) method was developed for screening meat for a wide range of antibiotics used in veterinary medicine. Full-scan mode under high resolution mass spectral conditions using an LTQ-Orbitrap mass spectrometer with resolving power 60,000 full width at half maximum (FWHM) was applied for analysis of the samples. Samples were prepared using two extraction protocols prior to LC-HRMS analysis. The scope of the method focuses on screening the following main families of antibacterial veterinary drugs: penicillins, cephalosporins, sulfonamides, macrolides, tetracyclines, aminoglucosides and quinolones. Compounds were successfully identified in spiked samples from their accurate mass and LC retention times from the acquired full-scan chromatogram. Automated data processing using ToxId software allowed rapid treatment of the data. Analyses of muscle tissues from real samples collected from antibiotic-treated animals was carried out using the above methodology and antibiotic residues were identified unambiguously. Further analysis of the data for real samples allowed the identification of the targeted antibiotic residues but also non-targeted compounds, such as some of their metabolites.

  3. Diagnostic ultrasound estimates of muscle mass and muscle quality discriminate between women with and without sarcopenia

    Catheeja eIsmail

    2015-10-01

    Full Text Available Introduction: Age-related changes in muscle mass and muscle tissue composition contribute to diminished strength in older adults. The objectives of this study are to examine if an assessment method using mobile diagnostic ultrasound augments well-known determinants of lean body mass (LBM to aid sarcopenia staging, and if a sonographic measure of muscle quality is associated with muscle performance.Methods: Twenty community-dwelling female subjects participated in the study (age = 43.4 ±20.9 years; BMI: 23.8, interquartile range: 8.5. Dual energy X-ray absorptiometry (DXA and diagnostic ultrasound morphometry were used to estimate LBM. Muscle tissue quality was estimated via the echogenicity using grayscale histogram analysis. Peak force was measured with grip dynamometry and scaled for body size. Bivariate and multiple regression analyses were used to determine the association of the predictor variables with appendicular lean mass (aLM/ht2, and examine the relationship between scaled peak force values and muscle echogenicity. The sarcopenia LBM cut point value of 6.75 kg/m2 determined participant assignment into the Normal LBM and Low LBM subgroups.Results: The selected LBM predictor variables were body mass index (BMI, ultrasound morphometry, and age. Although BMI exhibited a significant positive relationship with aLM/ht2 (adj. R2 = .61, p < .001, the strength of association improved with the addition of ultrasound morphometry and age as predictor variables (adj. R2 = .85, p < .001. Scaled peak force was associated with age and echogenicity (adj. R2 = .53, p < .001, but not LBM. The Low LBM subgroup of women (n = 10 had higher scaled peak force, lower BMI, and lower echogenicity values in comparison to the Normal LBM subgroup (n = 10; p < .05.Conclusions: Diagnostic ultrasound morphometry values are associated with LBM, and improve the BMI predictive model for aLM/ht2 in women. In addition, ultrasound proxy measures of muscle quality are more

  4. Muscle mass, BMI, and mortality among adults in the United States: A population-based cohort study.

    Abramowitz, Matthew K; Hall, Charles B; Amodu, Afolarin; Sharma, Deep; Androga, Lagu; Hawkins, Meredith

    2018-01-01

    The level of body-mass index (BMI) associated with the lowest risk of death remains unclear. Although differences in muscle mass limit the utility of BMI as a measure of adiposity, no study has directly examined the effect of muscle mass on the BMI-mortality relationship. Body composition was measured by dual-energy x-ray absorptiometry in 11,687 participants of the National Health and Nutrition Examination Survey 1999-2004. Low muscle mass was defined using sex-specific thresholds of the appendicular skeletal muscle mass index (ASMI). Proportional hazards models were created to model associations with all-cause mortality. At any level of BMI ≥22, participants with low muscle mass had higher body fat percentage (%TBF), an increased likelihood of diabetes, and higher adjusted mortality than other participants. Increases in %TBF manifested as 30-40% smaller changes in BMI than were observed in participants with preserved muscle mass. Excluding participants with low muscle mass or adjustment for ASMI attenuated the risk associated with low BMI, magnified the risk associated with high BMI, and shifted downward the level of BMI associated with the lowest risk of death. Higher ASMI was independently associated with lower mortality. Effects were similar in never-smokers and ever-smokers. Additional adjustment for waist circumference eliminated the risk associated with higher BMI. Results were unchanged after excluding unintentional weight loss, chronic illness, early mortality, and participants performing muscle-strengthening exercises or recommended levels of physical activity. Muscle mass mediates associations of BMI with adiposity and mortality and is inversely associated with the risk of death. After accounting for muscle mass, the BMI associated with the greatest survival shifts downward toward the normal range. These results provide a concrete explanation for the obesity paradox.

  5. The adipokine leptin increases skeletal muscle mass and significantly alters skeletal muscle miRNA expression profile in aged mice

    Hamrick, Mark W.; Herberg, Samuel; Arounleut, Phonepasong; He, Hong-Zhi; Shiver, Austin; Qi, Rui-Qun; Zhou, Li; Isales, Carlos M.

    2010-01-01

    Research highlights: → Aging is associated with muscle atrophy and loss of muscle mass, known as the sarcopenia of aging. → We demonstrate that age-related muscle atrophy is associated with marked changes in miRNA expression in muscle. → Treating aged mice with the adipokine leptin significantly increased muscle mass and the expression of miRNAs involved in muscle repair. → Recombinant leptin therapy may therefore be a novel approach for treating age-related muscle atrophy. -- Abstract: Age-associated loss of muscle mass, or sarcopenia, contributes directly to frailty and an increased risk of falls and fractures among the elderly. Aged mice and elderly adults both show decreased muscle mass as well as relatively low levels of the fat-derived hormone leptin. Here we demonstrate that loss of muscle mass and myofiber size with aging in mice is associated with significant changes in the expression of specific miRNAs. Aging altered the expression of 57 miRNAs in mouse skeletal muscle, and many of these miRNAs are now reported to be associated specifically with age-related muscle atrophy. These include miR-221, previously identified in studies of myogenesis and muscle development as playing a role in the proliferation and terminal differentiation of myogenic precursors. We also treated aged mice with recombinant leptin, to determine whether leptin therapy could improve muscle mass and alter the miRNA expression profile of aging skeletal muscle. Leptin treatment significantly increased hindlimb muscle mass and extensor digitorum longus fiber size in aged mice. Furthermore, the expression of 37 miRNAs was altered in muscles of leptin-treated mice. In particular, leptin treatment increased the expression of miR-31 and miR-223, miRNAs known to be elevated during muscle regeneration and repair. These findings suggest that aging in skeletal muscle is associated with marked changes in the expression of specific miRNAs, and that nutrient-related hormones such as leptin

  6. The adipokine leptin increases skeletal muscle mass and significantly alters skeletal muscle miRNA expression profile in aged mice

    Hamrick, Mark W., E-mail: mhamrick@mail.mcg.edu [Department of Cellular Biology and Anatomy, Institute of Molecular Medicine and Genetics, Medical College of Georgia, Augusta, GA (United States); Department of Orthopaedic Surgery, Institute of Molecular Medicine and Genetics, Medical College of Georgia, Augusta, GA (United States); Herberg, Samuel; Arounleut, Phonepasong [Department of Cellular Biology and Anatomy, Institute of Molecular Medicine and Genetics, Medical College of Georgia, Augusta, GA (United States); Department of Orthopaedic Surgery, Institute of Molecular Medicine and Genetics, Medical College of Georgia, Augusta, GA (United States); He, Hong-Zhi [Henry Ford Immunology Program, Henry Ford Health System, Detroit, MI (United States); Department of Dermatology, Henry Ford Health System, Detroit, MI (United States); Shiver, Austin [Department of Cellular Biology and Anatomy, Institute of Molecular Medicine and Genetics, Medical College of Georgia, Augusta, GA (United States); Department of Orthopaedic Surgery, Institute of Molecular Medicine and Genetics, Medical College of Georgia, Augusta, GA (United States); Qi, Rui-Qun [Henry Ford Immunology Program, Henry Ford Health System, Detroit, MI (United States); Department of Dermatology, Henry Ford Health System, Detroit, MI (United States); Zhou, Li [Henry Ford Immunology Program, Henry Ford Health System, Detroit, MI (United States); Department of Dermatology, Henry Ford Health System, Detroit, MI (United States); Department of Internal Medicine, Henry Ford Health System, Detroit, MI (United States); Isales, Carlos M. [Department of Cellular Biology and Anatomy, Institute of Molecular Medicine and Genetics, Medical College of Georgia, Augusta, GA (United States); Department of Orthopaedic Surgery, Institute of Molecular Medicine and Genetics, Medical College of Georgia, Augusta, GA (United States); others, and

    2010-09-24

    Research highlights: {yields} Aging is associated with muscle atrophy and loss of muscle mass, known as the sarcopenia of aging. {yields} We demonstrate that age-related muscle atrophy is associated with marked changes in miRNA expression in muscle. {yields} Treating aged mice with the adipokine leptin significantly increased muscle mass and the expression of miRNAs involved in muscle repair. {yields} Recombinant leptin therapy may therefore be a novel approach for treating age-related muscle atrophy. -- Abstract: Age-associated loss of muscle mass, or sarcopenia, contributes directly to frailty and an increased risk of falls and fractures among the elderly. Aged mice and elderly adults both show decreased muscle mass as well as relatively low levels of the fat-derived hormone leptin. Here we demonstrate that loss of muscle mass and myofiber size with aging in mice is associated with significant changes in the expression of specific miRNAs. Aging altered the expression of 57 miRNAs in mouse skeletal muscle, and many of these miRNAs are now reported to be associated specifically with age-related muscle atrophy. These include miR-221, previously identified in studies of myogenesis and muscle development as playing a role in the proliferation and terminal differentiation of myogenic precursors. We also treated aged mice with recombinant leptin, to determine whether leptin therapy could improve muscle mass and alter the miRNA expression profile of aging skeletal muscle. Leptin treatment significantly increased hindlimb muscle mass and extensor digitorum longus fiber size in aged mice. Furthermore, the expression of 37 miRNAs was altered in muscles of leptin-treated mice. In particular, leptin treatment increased the expression of miR-31 and miR-223, miRNAs known to be elevated during muscle regeneration and repair. These findings suggest that aging in skeletal muscle is associated with marked changes in the expression of specific miRNAs, and that nutrient

  7. Role of Protein Carbonylation in Skeletal Muscle Mass Loss Associated with Chronic Conditions

    Esther Barreiro

    2016-05-01

    Full Text Available Muscle dysfunction, characterized by a reductive remodeling of muscle fibers, is a common systemic manifestation in highly prevalent conditions such as chronic heart failure (CHF, chronic obstructive pulmonary disease (COPD, cancer cachexia, and critically ill patients. Skeletal muscle dysfunction and impaired muscle mass may predict morbidity and mortality in patients with chronic diseases, regardless of the underlying condition. High levels of oxidants may alter function and structure of key cellular molecules such as proteins, DNA, and lipids, leading to cellular injury and death. Protein oxidation including protein carbonylation was demonstrated to modify enzyme activity and DNA binding of transcription factors, while also rendering proteins more prone to proteolytic degradation. Given the relevance of protein oxidation in the pathophysiology of many chronic conditions and their comorbidities, the current review focuses on the analysis of different studies in which the biological and clinical significance of the modifications induced by reactive carbonyls on proteins have been explored so far in skeletal muscles of patients and animal models of chronic conditions such as COPD, disuse muscle atrophy, cancer cachexia, sepsis, and physiological aging. Future research will elucidate the specific impact and sites of reactive carbonyls on muscle protein content and function in human conditions.

  8. Appendicular Skeletal Muscle Mass Reference Values and the Peak Muscle Mass to Identify Sarcopenia among Iranian Healthy Population.

    Shafiee, Gita; Ostovar, Afshin; Heshmat, Ramin; Keshtkar, Abbas Ali; Sharifi, Farshad; Shadman, Zhaleh; Nabipour, Iraj; Soltani, Akbar; Larijani, Bagher

    2018-01-01

    Sacopenia is a common problem in elderly with the adverse outcomes. The objective of this study was to estimate the peak appendicular skeletal muscle mass (ASM) and age of its attainment by sex among the Iranian population. A total of 691 men and women aged 18-94 years participated in this cross-sectional, population-based study in Bushehr, Iran. ASM was measured by dual X-ray absorptiometry. Cutoff points for men and women were established considering two standard deviations (SDs) below the mean values of the skeletal muscle index (SMI) for young reference groups. The relationship between ASM and age was described by the second-degree regression models. Two SDs below the mean SMIs of reference groups were as cutoff values of low muscle mass in Iranian population. The peak ASM values were 21.35 ± 0.12 Kg and 13.68 ± 0.10 Kg, and the age at peak ASM were 26 (24-28) years and 34 (33-35) years for men and women, respectively. Mean and SD of SMI in those ages were 7.01 ± 0.02 Kg/m 2 and 5.44 ± 0.02 Kg/m 2 among men and women, respectively. Calculated cutoff values of low muscle mass among the Iranian population were 7.0 Kg/m 2 and 5.4 Kg/m 2 among men and women, respectively. Iranian reference values of SMI for both genders were similar to Asia Working Group for Sarcopenia recommendation and lower than the United States and European values. Further studies from different nations and the Middle East countries are needed to obtain reference values for populations, enabling the researchers for comparison and also more valid reports on sarcopenia prevalence.

  9. Psoas muscle cross-sectional area as a measure of whole body lean muscle mass in maintenance hemodialysis patients

    Morrell, Glen R.; Ikizler, Talat A.; Chen, Xiaorui; Heilbrun, Marta E.; Wei, Guo; Boucher, Robert; Beddhu, Srinivasan

    2016-01-01

    Objective We investigate whether psoas or paraspinous muscle area measured on a single L4–5 image is a useful measure of whole lean body mass compared to dedicated mid-thigh magnetic resonance imaging (MRI). Design Observational study. Setting Outpatient dialysis units and a research clinic. Subjects 105 adult participants on maintenance hemodialysis. No control group was used. Exposure variables Psoas muscle area, paraspinous muscle area, and mid-thigh muscle area (MTMA) were measured by MRI. Main outcome measure Lean body mass was measured by dual-energy absorptiometry (DEXA) scan. Results In separate multivariable linear regression models, psoas, paraspinous, and mid-thigh muscle area were associated with increase in lean body mass. In separate multivariate logistic regression models, c-statistics for diagnosis of sarcopenia (defined as lean body mass) were 0.69 for paraspinous muscle area, 0.81 for psoas muscle area, and 0.89 for mid-thigh muscle area. With sarcopenia defined as lean body mass, the corresponding c-statistics were 0.71, 0.92, and 0.94. Conclusions We conclude that psoas muscle area provides a good measure of whole body muscle mass, better than paraspinous muscle area but slightly inferior to mid thigh measurement. Hence, in body composition studies a single axial MR image at the L4–L5 level can be used to provide information on both fat and muscle and may eliminate the need for time-consuming measurement of muscle area in the thigh. PMID:26994780

  10. Comparison of muscle/lean mass measurement methods: correlation with functional and biochemical testing.

    Buehring, B; Siglinsky, E; Krueger, D; Evans, W; Hellerstein, M; Yamada, Y; Binkley, N

    2018-03-01

    DXA-measured lean mass is often used to assess muscle mass but has limitations. Thus, we compared DXA lean mass with two novel methods-bioelectric impedance spectroscopy and creatine (methyl-d3) dilution. The examined methodologies did not measure lean mass similarly and the correlation with muscle biomarkers/function varied. Muscle function tests predict adverse health outcomes better than lean mass measurement. This may reflect limitations of current mass measurement methods. Newer approaches, e.g., bioelectric impedance spectroscopy (BIS) and creatine (methyl-d3) dilution (D3-C), may more accurately assess muscle mass. We hypothesized that BIS and D3-C measured muscle mass would better correlate with function and bone/muscle biomarkers than DXA measured lean mass. Evaluations of muscle/lean mass, function, and serum biomarkers were obtained in older community-dwelling adults. Mass was assessed by DXA, BIS, and orally administered D3-C. Grip strength, timed up and go, and jump power were examined. Potential muscle/bone serum biomarkers were measured. Mass measurements were compared with functional and serum data using regression analyses; differences between techniques were determined by paired t tests. Mean (SD) age of the 112 (89F/23M) participants was 80.6 (6.0) years. The lean/muscle mass assessments were correlated (.57-.88) but differed (p Lean mass measures were unrelated to the serum biomarkers measured. These three methodologies do not similarly measure muscle/lean mass and should not be viewed as being equivalent. Functional tests assessing maximal muscle strength/power (grip strength and jump power) correlated with all mass measures whereas gait speed was not. None of the selected serum measures correlated with mass. Efforts to optimize muscle mass assessment and identify their relationships with health outcomes are needed.

  11. Relationship of interleukin-6 and tumor necrosis factor-alpha with muscle mass and muscle strength in elderly men and women : the Health ABC Study

    Visser, Marjolein; Pahor, Marco; Taaffe, Dennis R; Goodpaster, Bret H; Simonsick, Eleanor M; Newman, Anne B; Nevitt, Michael; Harris, Tamara B

    BACKGROUND: A decline in muscle mass and muscle strength characterizes normal aging. As clinical and animal studies show a relationship between higher cytokine levels and low muscle mass, the aim of this study was to investigate whether markers of inflammation are associated with muscle mass and

  12. Fat-Free Mass and Skeletal Muscle Mass Five Years After Bariatric Surgery.

    Davidson, Lance E; Yu, Wen; Goodpaster, Bret H; DeLany, James P; Widen, Elizabeth; Lemos, Thaisa; Strain, Gladys W; Pomp, Alfons; Courcoulas, Anita P; Lin, Susan; Janumala, Isaiah; Thornton, John C; Gallagher, Dympna

    2018-07-01

    This study investigated changes in fat-free mass (FFM) and skeletal muscle 5 years after surgery in participants from the Longitudinal Assessment of Bariatric Surgery-2 trial. A three-compartment model assessed FFM, and whole-body magnetic resonance imaging (MRI) quantified skeletal muscle mass prior to surgery (T0) and 1 year (T1), 2 years (T2), and 5 years (T5) postoperatively in 93 patients (85% female; 68% Caucasian; age 44.2 ± 11.6 years) who underwent gastric bypass (RYGB), sleeve gastrectomy, or adjustable gastric band. Repeated-measures mixed models were used to analyze the data. Significant weight loss occurred across all surgical groups in females from T0 to T1. FFM loss from T0 to T1 was greater after RYGB (mean ± SE: -6.9 ± 0.6 kg) than adjustable gastric band (-3.5 ± 1.4 kg; P FFM (-3.3 ± 0.7 kg; P FFM loss while maintaining FFM and skeletal muscle from T1 to T5. Between 1 and 5 years following common bariatric procedures, FFM and skeletal muscle are maintained or decrease minimally. The changes observed in FFM and muscle during the follow-up phase may be consistent with aging. © 2018 The Obesity Society.

  13. Association of low back pain with muscle stiffness and muscle mass of the lumbar back muscles, and sagittal spinal alignment in young and middle-aged medical workers.

    Masaki, Mitsuhiro; Aoyama, Tomoki; Murakami, Takashi; Yanase, Ko; Ji, Xiang; Tateuchi, Hiroshige; Ichihashi, Noriaki

    2017-11-01

    Muscle stiffness of the lumbar back muscles in low back pain (LBP) patients has not been clearly elucidated because quantitative assessment of the stiffness of individual muscles was conventionally difficult. This study aimed to examine the association of LBP with muscle stiffness assessed using ultrasonic shear wave elastography (SWE) and muscle mass of the lumbar back muscle, and spinal alignment in young and middle-aged medical workers. The study comprised 23 asymptomatic medical workers [control (CTR) group] and 9 medical workers with LBP (LBP group). Muscle stiffness and mass of the lumbar back muscles (lumbar erector spinae, multifidus, and quadratus lumborum) in the prone position were measured using ultrasonic SWE. Sagittal spinal alignment in the standing and prone positions was measured using a Spinal Mouse. The association with LBP was investigated by multiple logistic regression analysis with a forward selection method. The analysis was conducted using the shear elastic modulus and muscle thickness of the lumbar back muscles, and spinal alignment, age, body height, body weight, and sex as independent variables. Multiple logistic regression analysis showed that muscle stiffness of the lumbar multifidus muscle and body height were significant and independent determinants of LBP, but that muscle mass and spinal alignment were not. Muscle stiffness of the lumbar multifidus muscle in the LBP group was significantly higher than that in the CTR group. The results of this study suggest that LBP is associated with muscle stiffness of the lumbar multifidus muscle in young and middle-aged medical workers. Copyright © 2017 Elsevier Ltd. All rights reserved.

  14. A low muscle mass increases mortality in compensated cirrhotic patients with sepsis.

    Lucidi, Cristina; Lattanzi, Barbara; Di Gregorio, Vincenza; Incicco, Simone; D'Ambrosio, Daria; Venditti, Mario; Riggio, Oliviero; Merli, Manuela

    2018-05-01

    Severe infections and muscle wasting are both associated to poor outcome in cirrhosis. A possible synergic effect of these two entities in cirrhotic patients has not been previously investigated. We aimed at analysing if a low muscle mass may deteriorate the outcome of cirrhotic patients with sepsis. Consecutive cirrhotic patients hospitalized for sepsis were enrolled in the study. Patients were classified for the severity of liver impairment (Child-Pugh class) and for the presence of "low muscle mass" (mid-arm muscle circumferencelow muscle mass. In patients with and without low muscle mass, severity of liver disease and characteristics of infections were similar. Mortality tended to be higher in patients with low muscle mass (47% vs 26%, P = .06). A multivariate analysis selected low muscle mass (P low muscle mass compared with those without (50% vs 16%; P = .01). The mortality rate and the incidence of complications in malnourished patients classified in Child-Pugh A-B were similar to those Child-Pugh C. Low muscle mass worsen prognosis in cirrhotic patients with severe infections. This is particularly evident in patients with Child A-B cirrhosis in whom the coexistence of low muscle mass and sepsis caused a negative impact on mortality similar to that observable in all Child C patients with sepsis. © 2018 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  15. Alfacalcidol improves muscle power, muscle function and balance in elderly patients with reduced bone mass.

    Schacht, E; Ringe, Johann D

    2012-01-01

    We investigated the effect of daily therapy with 1 mcg alfacalcidol (Doss(®)-TEVA/AWD-pharma) on muscle power, muscle function, balance performance and fear of falls in an open, multi-centered, uncontrolled, prospective study on a cohort of patients with reduced bone mass. Among the 2,097 participants, 87.1% were post-menopausal women and 12.9% were men. Mean age was 74.8 years and mean body mass index (BMI) 26.3 kg/m². A total of 75.3% of the study population had osteoporosis, 81% a diagnosis of "increased risk of falls" and 70.1% had a creatinine clearance (CrCl) of power tests at onset and after 3 and 6 months: the timed up and go test (TUG) and the chair rising test (CRT). At baseline and after 6 months, participants performed the tandem gait test (TGT) and filled out a questionnaire evaluating fear of falling. Successful performance in the muscle tests is associated with a significantly lower risk of falls and non-vertebral fractures in elderly patients (successful test performance: TUG ≤ 10 s (sec), CRT ≤ 10 s, TGT ≥ 8 steps). A significant improvement in the performance of the two muscle tests was proved already after 3 months of treatment with alfacalcidol and further increased by the end of the therapeutic intervention. There were significant increases in the number of participants able to successfully perform the tests: 24.6% at baseline and 46.3% at the end of trial for the TUG (P balance test (TGT) increased from 36.0% at onset to 58.6% at the end of the trial (P power, muscle function and balance and reduces fear of falls. The significant improvement in the three muscle and balance tests and fear of falls may have a preventative effect on falls and fractures. We suggest that the quantitative risk tests used in this study could be reliable surrogate parameters for the risk of falls and fractures in elderly patients.

  16. Relationship between oxidative stress and muscle mass loss in early postmenopause: an exploratory study.

    Zacarías-Flores, Mariano; Sánchez-Rodríguez, Martha A; García-Anaya, Oswaldo Daniel; Correa-Muñoz, Elsa; Mendoza-Núñez, Víctor Manuel

    2018-04-09

    Endocrine changes due to menopause have been associated to oxidative stress and muscle mass loss. The study objective was to determine the relationship between both variables in early postmenopause. An exploratory, cross-sectional study was conducted in 107 pre- and postmenopausal women (aged 40-57 years). Levels of serum lipid peroxides and uric acid and enzymes superoxide dismutase and glutathione peroxidase, as well as total plasma antioxidant capacity were measured as oxidative stress markers. Muscle mass using bioelectrical impedance and muscle strength using dynamometry were also measured. Muscle mass, skeletal muscle index, fat-free mass, and body mass index were calculated. More than 90% of participants were diagnosed with overweight or obesity. Postmenopausal women had lower values of muscle mass and strength markers, with a negative correlation between lipid peroxide level and skeletal muscle index (r= -0.326, p<.05), and a positive correlation between uric acid and skeletal muscle index (r=0.295, p<.05). A multivariate model including oxidative stress markers, age, and waist circumference showed lipid peroxide level to be the main contributor to explain the decrease in skeletal muscle mass in postmenopause, since for every 0.1μmol/l increase in lipid peroxide level, skeletal muscle index decreases by 3.03 units. Our findings suggest an association between increased oxidative stress and muscle mass loss in early postmenopause. Copyright © 2018 SEEN y SED. Publicado por Elsevier España, S.L.U. All rights reserved.

  17. Estimation of thigh muscle mass with magnetic resonance imaging in older adults and people with chronic obstructive pulmonary disease.

    Mathur, Sunita; Takai, Karen Pr; Macintyre, Donna L; Reid, Darlene

    2008-02-01

    Quantifying muscle mass is an essential part of physical therapy assessment, particularly in older adults and in people with chronic conditions associated with muscle atrophy. The purposes of this study were to examine the relationship between muscle cross-sectional area (CSA) and volume by use of magnetic resonance imaging (MRI) and to compare anthropometric estimations of midthigh CSA with measurements obtained from MRI. Twenty older adults who were healthy and 20 people with chronic obstructive pulmonary disease (COPD), matched for age, sex, and body mass index, underwent MRI to obtain measurements of thigh muscle CSA and volume. Anthropometric measurements (skinfold thickness and thigh circumference) were used to estimate midthigh CSA. Muscle volumes were significantly lower in the people with COPD than in the older adults who were healthy. Moderate to high correlations were found between midthigh CSA and volume in both groups (r=.61-.94). Anthropometric measurements tended to overestimate midthigh CSA in both the people with COPD (estimated CSA=64.9+/-17.8; actual CSA=48.3+/-10.2 cm(2)) and the older adults who were healthy (estimated quadriceps femoris muscle CSA=65.0+/-14.0; actual CSA=56.8+/-13.5 cm(2)). Furthermore, the estimated quadriceps femoris muscle CSAs were not sensitive enough to detect a difference in muscle size between people with COPD and controls. Thigh circumference alone was not different between groups and showed only low to moderate correlations with muscle volume (r=.19-.47). Muscle CSA measured from a single slice provides a good indication of volume, but the most representative slice should be chosen on the basis of the muscle group of interest. Thigh circumference is not correlated with muscle volume and, therefore, should not be used as an indicator of muscle size. The development of population-specific reference equations for estimating muscle CSA from anthropometric measurements is warranted.

  18. Relationship between Handgrip Strength and Muscle Mass in Female Survivors of Breast Cancer: A Mediation Analysis.

    Benavides-Rodríguez, Lorena; García-Hermoso, Antonio; Rodrigues-Bezerra, Diogo; Izquierdo, Mikel; Correa-Bautista, Jorge Enrique; Ramírez-Vélez, Robinson

    2017-07-04

    This study explored the mediating factors of sarcopenia in a group of women survivors of breast cancer in Bogotá, Colombia. This was a descriptive cross-sectional study with 98 women survivors of breast cancer, who were registered with the SIMMON (Integrated Synergies to Improve Oncological Management in Colombia) Foundation. Body weight, height, and waist circumference (WC) were measured, and body mass index (BMI) was calculated. Body composition (percentage of fat and muscle mass) was evaluated via four-pole bioelectrical impedance analysis. Sarcopenia was defined as low muscle mass plus low grip strength or low gait speed (European Working Group on Sarcopenia in Older People (EWGSOP) criteria). A "causal" mediation analysis with the Baron & Kenny procedure (PROCESS ® macro, Columbus, OH, USA) was used to explore variables related to sarcopenia. Analyses were performed with the IBM SPSS 21 statistical package (SPSS Inc., Chicago, IL, USA). The significance level of the results obtained in the hypothesis contrast was p < 0.05. The mean age of the sample was 65.5 ± 5.9 years, with a BMI of 27.8 ± 4.7 kg/m². The prevalence of sarcopenia was 22.4%. Linear regression models suggest a partial mediation of anthropometric parameters (body mass, body mass index and waist circumference) in the association between handgrip strength and muscle mass. In conclusion, one in every five women survivors of breast cancer had sarcopenia. The findings seem to emphasize the importance of obesity prevention in women survivors of breast cancer, suggesting that high handgrip strength may not relate closely to greater muscle mass and therefore would not exclude the risk of sarcopenia.

  19. Proteome-wide muscle protein fractional synthesis rates predict muscle mass gain in response to a selective androgen receptor modulator in rats.

    Shankaran, Mahalakshmi; Shearer, Todd W; Stimpson, Stephen A; Turner, Scott M; King, Chelsea; Wong, Po-Yin Anne; Shen, Ying; Turnbull, Philip S; Kramer, Fritz; Clifton, Lisa; Russell, Alan; Hellerstein, Marc K; Evans, William J

    2016-03-15

    Biomarkers of muscle protein synthesis rate could provide early data demonstrating anabolic efficacy for treating muscle-wasting conditions. Androgenic therapies have been shown to increase muscle mass primarily by increasing the rate of muscle protein synthesis. We hypothesized that the synthesis rate of large numbers of individual muscle proteins could serve as early response biomarkers and potentially treatment-specific signaling for predicting the effect of anabolic treatments on muscle mass. Utilizing selective androgen receptor modulator (SARM) treatment in the ovariectomized (OVX) rat, we applied an unbiased, dynamic proteomics approach to measure the fractional synthesis rates (FSR) of 167-201 individual skeletal muscle proteins in triceps, EDL, and soleus. OVX rats treated with a SARM molecule (GSK212A at 0.1, 0.3, or 1 mg/kg) for 10 or 28 days showed significant, dose-related increases in body weight, lean body mass, and individual triceps but not EDL or soleus weights. Thirty-four out of the 94 proteins measured from the triceps of all rats exhibited a significant, dose-related increase in FSR after 10 days of SARM treatment. For several cytoplasmic proteins, including carbonic anhydrase 3, creatine kinase M-type (CK-M), pyruvate kinase, and aldolase-A, a change in 10-day FSR was strongly correlated (r(2) = 0.90-0.99) to the 28-day change in lean body mass and triceps weight gains, suggesting a noninvasive measurement of SARM effects. In summary, FSR of multiple muscle proteins measured by dynamics of moderate- to high-abundance proteins provides early biomarkers of the anabolic response of skeletal muscle to SARM. Copyright © 2016 the American Physiological Society.

  20. The effect Mat Pilates practice on muscle mass in elderly women

    Leliz Cristina Sampaio Queiroz

    2016-01-01

    Full Text Available Objective: to verify that the Mat Pilates practice increases muscle mass in elderly women. Methods: quasi-experimental study with primary data collection and with a convenience sample. The muscle mass of 43 elderly was evaluated for 11 weeks, by calculating the arm muscle area, before and after the intervention. Results:statistically significant difference was observed (p<0.002 between the average value of the arm muscle area, before (35.56cm2 and after the exercises (42.72cm2. Conclusion: mat Pilates program generates positive effect on increasing the muscle mass of elderly.

  1. Creatine Loading Does Not Preserve Muscle Mass or Strength During Leg Immobilization in Healthy, Young Males

    Backx, Evelien M.P.; Hangelbroek, Roland; Snijders, Tim; Verscheijden, Marie Louise; Verdijk, Lex B.; Groot, de Lisette C.P.G.M.; Loon, van Luc J.C.

    2017-01-01

    Background: A short period of leg immobilization leads to rapid loss of muscle mass and strength. Creatine supplementation has been shown to increase lean body mass in active individuals and can be used to augment gains in muscle mass and strength during prolonged resistance-type exercise

  2. Correlation between Body Mass Index, Gender, and Skeletal Muscle Mass Cut off Point in Bandung

    Richi Hendrik Wattimena

    2017-09-01

    Full Text Available Objective: To determine the average skeletal muscle mass (SMM value in young adults as a reference population; to analyze the correlation of gender, and body mass index to the cut off point; and to determine skeletal muscle mass cut off points of population in Bandung, Indonesia. Methods: This was a cross-sectional study involving 199 participants, 122 females and 77 males. The sampling technique used was the multistage random sampling. The participants were those who lived in four major regions in Bandung, Indonesia: Sukajadi, Cicadas, Buah Batu, and Cibaduyut. Results: The average appendicular skeletal mass index (ASMI in females and males based on body mass index (BMI were identified. The average ASMI values for normal BMI in females was 5.982±0.462 kg/m2 while the average ASMI values normal BMI for males was 7.581±0.744 kg/m2 Conclusions: A correlation between BMI and ASMI that was considered statistically significant was found in females (0.7712; p<0.05 and a very significant correlation was seen in males (0.870; p<0.05. The cut off points were defined by the normal BMI, which were 5.059 for females and 6.093 for males.

  3. High-intensity body weight training is comparable to combined training in changes in muscle mass, physical performance, inflammatory markers and metabolic health in postmenopausal women at high risk for type 2 diabetes mellitus: A randomized controlled clinical trial.

    Martins, Fernanda Maria; de Paula Souza, Aletéia; Nunes, Paulo Ricardo Prado; Michelin, Márcia Antoniazi; Murta, Eddie Fernando Candido; Resende, Elisabete Aparecida Mantovani Rodrigues; de Oliveira, Erick Prado; Orsatti, Fábio Lera

    2018-07-01

    This study compared the effects of 12 weeks of high-intensity interval body weight training (HIBWT) with combined training (COMT; aerobic and resistance exercises on body composition, a 6-minute walk test (6MWT; physical performance), insulin resistance (IR) and inflammatory markers in postmenopausal women (PW) at high risk of type 2 diabetes mellitus (TDM2). In this randomized controlled clinical study, 16 PW at high risk of TDM2 were randomly allocated into two groups: HIBWT (n = 8) and COMT (n = 8). The HIBWT group performed a training protocol (length time ~28 min) consisting of ten sets of 60 s of high intensity exercise interspersed by a recovery period of 60 s of low intensity exercise. The COMT group performed a training protocol (length time ~60 min) consisting of a 30 min walk of moderate intensity following by five resistance exercises. All training sessions were performed in the university gym facility three days a week (no consecutive days) for 12 weeks. All outcomes (body composition, muscle function, and IR and inflammatory markers) were assessed at the baseline and at the end of the study. Both groups increased (P  0.05) from the effects of COMT. There was a significant (P high risk of TDM2. The patients were part of a 12-week training study (ClinicalTrials.gov Identifier: NCT03200639). Copyright © 2018 Elsevier Inc. All rights reserved.

  4. A New Equation to Estimate Muscle Mass from Creatinine and Cystatin C.

    Sun-wook Kim

    Full Text Available With evaluation for physical performance, measuring muscle mass is an important step in detecting sarcopenia. However, there are no methods to estimate muscle mass from blood sampling.To develop a new equation to estimate total-body muscle mass with serum creatinine and cystatin C level, we designed a cross-sectional study with separate derivation and validation cohorts. Total body muscle mass and fat mass were measured using dual-energy x-ray absorptiometry (DXA in 214 adults aged 25 to 84 years who underwent physical checkups from 2010 to 2013 in a single tertiary hospital. Serum creatinine and cystatin C levels were also examined.Serum creatinine was correlated with muscle mass (P < .001, and serum cystatin C was correlated with body fat mass (P < .001 after adjusting glomerular filtration rate (GFR. After eliminating GFR, an equation to estimate total-body muscle mass was generated and coefficients were calculated in the derivation cohort. There was an agreement between muscle mass calculated by the novel equation and measured by DXA in both the derivation and validation cohort (P < .001, adjusted R2 = 0.829, β = 0.95, P < .001, adjusted R2 = 0.856, β = 1.03, respectively.The new equation based on serum creatinine and cystatin C levels can be used to estimate total-body muscle mass.

  5. Muscle Mass Depletion Associated with Poor Outcome of Sepsis in the Emergency Department.

    Lee, YoonJe; Park, Hyun Kyung; Kim, Won Young; Kim, Myung Chun; Jung, Woong; Ko, Byuk Sung

    2018-05-08

    Muscle mass depletion has been suggested to predict morbidity and mortality in various diseases. However, it is not well known whether muscle mass depletion is associated with poor outcome in sepsis. We hypothesized that muscle mass depletion is associated with poor outcome in sepsis. Retrospective observational study was conducted in an emergency department during a 9-year period. Medical records of 627 patients with sepsis were reviewed. We divided the patients into 2 groups according to 28-day mortality and compared the presence of muscle mass depletion assessed by the cross-sectional area of the psoas muscle at the level of the third lumbar vertebra on abdomen CT scans. Univariate and multivariate logistic regression analyses were conducted to examine the association of scarcopenia on the outcome of sepsis. A total of 274 patients with sepsis were finally included in the study: 45 (16.4%) did not survive on 28 days and 77 patients (28.1%) were identified as having muscle mass depletion. The presence of muscle mass depletion was independently associated with 28-day mortality on multivariate logistic analysis (OR 2.79; 95% CI 1.35-5.74, p = 0.01). Muscle mass depletion evaluated by CT scan was associated with poor outcome of sepsis patients. Further studies on the appropriateness of specific treatment for muscle mass depletion with sepsis are needed. © 2018 S. Karger AG, Basel.

  6. Supplementing Breakfast with a Vitamin D and Leucine-Enriched Whey Protein Medical Nutrition Drink Enhances Postprandial Muscle Protein Synthesis and Muscle Mass in Healthy Older Men.

    Chanet, Audrey; Verlaan, Sjors; Salles, Jérôme; Giraudet, Christophe; Patrac, Véronique; Pidou, Véronique; Pouyet, Corinne; Hafnaoui, Nordine; Blot, Adeline; Cano, Noël; Farigon, Nicolas; Bongers, Anke; Jourdan, Marion; Luiking, Yvette; Walrand, Stéphane; Boirie, Yves

    2017-12-01

    Background: A promising strategy to help older adults preserve or build muscle mass is to optimize muscle anabolism through providing an adequate amount of high-quality protein at each meal. Objective: This "proof of principle" study investigated the acute effect of supplementing breakfast with a vitamin D and leucine-enriched whey protein medical nutrition drink on postprandial muscle protein synthesis and longer-term effect on muscle mass in healthy older adults. Methods: A randomized, placebo-controlled, double-blind study was conducted in 24 healthy older men [mean ± SD: age 71 ± 4 y; body mass index (in kg/m 2 ) 24.7 ± 2.8] between September 2012 and October 2013 at the Unit of Human Nutrition, University of Auvergne, Clermont-Ferrand, France. Participants received a medical nutrition drink [test group; 21 g leucine-enriched whey protein, 9 g carbohydrates, 3 g fat, 800 IU cholecalciferol (vitamin D 3 ), and 628 kJ] or a noncaloric placebo (control group) before breakfast for 6 wk. Mixed muscle protein fractional synthesis rate (FSR) was measured at week 0 in the basal and postprandial state, after study product intake with a standardized breakfast with the use of l-[ 2 H 5 ]-phenylalanine tracer methodology. The longer-term effect of the medical nutrition drink was evaluated by measurement of appendicular lean mass, representing skeletal muscle mass at weeks 0 and 6, by dual-energy X-ray absorptiometry. Results: Postprandial FSR (0-240 min) was higher in the test group than in the control group [estimate of difference (ED): 0.022%/h; 95% CI: 0.010%/h, 0.035%/h; ANCOVA, P = 0.001]. The test group gained more appendicular lean mass than the control group after 6 wk (ED: 0.37 kg; 95% CI: 0.03, 0.72 kg; ANCOVA, P = 0.035), predominantly as leg lean mass (ED: 0.30 kg; 95% CI: 0.03, 0.57 kg; ANCOVA, P = 0.034). Conclusions: Supplementing breakfast with a vitamin D and leucine-enriched whey protein medical nutrition drink stimulated postprandial muscle protein

  7. Relationships of 35 lower limb muscles to height and body mass quantified using MRI.

    Handsfield, Geoffrey G; Meyer, Craig H; Hart, Joseph M; Abel, Mark F; Blemker, Silvia S

    2014-02-07

    Skeletal muscle is the most abundant tissue in the body and serves various physiological functions including the generation of movement and support. Whole body motor function requires adequate quantity, geometry, and distribution of muscle. This raises the question: how do muscles scale with subject size in order to achieve similar function across humans? While much of the current knowledge of human muscle architecture is based on cadaver dissection, modern medical imaging avoids limitations of old age, poor health, and limited subject pool, allowing for muscle architecture data to be obtained in vivo from healthy subjects ranging in size. The purpose of this study was to use novel fast-acquisition MRI to quantify volumes and lengths of 35 major lower limb muscles in 24 young, healthy subjects and to determine if muscle size correlates with bone geometry and subject parameters of mass and height. It was found that total lower limb muscle volume scales with mass (R(2)=0.85) and with the height-mass product (R(2)=0.92). Furthermore, individual muscle volumes scale with total muscle volume (median R(2)=0.66), with the height-mass product (median R(2)=0.61), and with mass (median R(2)=0.52). Muscle volume scales with bone volume (R(2)=0.75), and muscle length relative to bone length is conserved (median s.d.=2.1% of limb length). These relationships allow for an arbitrary subject's individual muscle volumes to be estimated from mass or mass and height while muscle lengths may be estimated from limb length. The dataset presented here can further be used as a normative standard to compare populations with musculoskeletal pathologies. © 2013 Published by Elsevier Ltd.

  8. Non-Hodgkin lymphoma in skeletal muscle manifesting as homogeneous masses with CT attenuation similar to muscle

    Panicek, D.M.; Lautin, J.L.; Schwartz, L.H.; Castellino, R.A.

    1997-01-01

    Two cases are presented of masses in muscle due to non-Hodgkin lymphoma (NHL) that were homogeneous and isoattenuating to normal muscle on CT. In each case, the mass was clinically suspected of representing soft tissue sarcoma. However, the masses were relatively inapparent on CT, being visible predominantly as mass effect - an appearance unlike that of soft tissue sarcomas. It is important to be aware that NHL in muscle can be difficult to detect at CT, even with intravenous contrast enhancement; therefore, a clinically apparent mass should not be dismissed on the basis of an apparently unremarkable CT scan of the region. Such findings should suggest the diagnosis of NHL rather than sarcoma. (orig.)

  9. High-Resolution Mass Spectrometers

    Marshall, Alan G.; Hendrickson, Christopher L.

    2008-07-01

    Over the past decade, mass spectrometry has been revolutionized by access to instruments of increasingly high mass-resolving power. For small molecules up to ˜400 Da (e.g., drugs, metabolites, and various natural organic mixtures ranging from foods to petroleum), it is possible to determine elemental compositions (CcHhNnOoSsPp…) of thousands of chemical components simultaneously from accurate mass measurements (the same can be done up to 1000 Da if additional information is included). At higher mass, it becomes possible to identify proteins (including posttranslational modifications) from proteolytic peptides, as well as lipids, glycoconjugates, and other biological components. At even higher mass (˜100,000 Da or higher), it is possible to characterize posttranslational modifications of intact proteins and to map the binding surfaces of large biomolecule complexes. Here we review the principles and techniques of the highest-resolution analytical mass spectrometers (time-of-flight and Fourier transform ion cyclotron resonance and orbitrap mass analyzers) and describe some representative high-resolution applications.

  10. The Intriguing Regulators of Muscle Mass in Sarcopenia and Muscular Dystrophy

    Sakuma, Kunihiro; Aoi, Wataru; Yamaguchi, Akihiko

    2014-01-01

    Recent advances in our understanding of the biology of muscle have led to new interest in the pharmacological treatment of muscle wasting. Loss of muscle mass and increased intramuscular fibrosis occur in both sarcopenia and muscular dystrophy. Several regulators (mammalian target of rapamycin, serum response factor, atrogin-1, myostatin, etc.) seem to modulate protein synthesis and degradation or transcription of muscle-specific genes during both sarcopenia and muscular dystrophy. This revie...

  11. Comparison of skeletal muscle mass to fat-free mass ratios among different ethnic groups.

    Abe, T; Bemben, M G; Kondo, M; Kawakami, Y; Fukunaga, T

    2012-01-01

    Asians seem to have less skeletal muscle mass (SMM) than other ethnic groups, but it is not clear whether relative SMM, i.e., SMM / height square or SMM to fat-free mass (FFM) ratio, differs among different ethnic groups at the same level of body mass index (BMI). To compare the SMM to fat-free mass (FFM) ratio as well as anthropometric variables and body composition among 3 ethnic groups. Three hundred thirty-nine Japanese, 343 Brazilian, and 183 German men and women were recruited for this cross-sectional study. Muscle thickness (MTH) and subcutaneous fat thickness (FTH) were measured by ultrasound at nine sites on the anterior and posterior aspects of the body. FTH was used to estimate the body density, from which fat mass and fat-free mass (FFM) was calculated by using Brozek equation. Total SMM was estimated from ultrasound-derived prediction equations. Percentage body fat was similar among the ethnic groups in men, while Brazilians were higher than Japanese in women. In German men and women, absolute SMM and FFM were higher than in their Japanese and Brazilians counterparts. SMM index and SMM:FFM ratios were similar among the ethnic groups in women, excluding SMM:FFM ratio in Brazilian. In men, however, these relative values (SMM index and SMM:FFM ratio) were still higher in Germans. After adjusting for age and BMI, the SMM index and SMM:FFM ratios were lower in Brazilian men and women compared with the other two ethnic groups, while the SMM index and SMM:FFM ratios were similar in Japanese and German men and women, excluding SMM:FFM ratio in women. Our results suggest that relative SMM is not lower in Asian populations compared with European populations after adjusted by age and BMI.

  12. Genes Whose Gain or Loss-Of-Function Increases Skeletal Muscle Mass in Mice: A Systematic Literature Review

    Sander A. J. Verbrugge

    2018-05-01

    Full Text Available Skeletal muscle mass differs greatly in mice and humans and this is partially inherited. To identify muscle hypertrophy candidate genes we conducted a systematic review to identify genes whose experimental loss or gain-of-function results in significant skeletal muscle hypertrophy in mice. We found 47 genes that meet our search criteria and cause muscle hypertrophy after gene manipulation. They are from high to small effect size: Ski, Fst, Acvr2b, Akt1, Mstn, Klf10, Rheb, Igf1, Pappa, Ppard, Ikbkb, Fstl3, Atgr1a, Ucn3, Mcu, Junb, Ncor1, Gprasp1, Grb10, Mmp9, Dgkz, Ppargc1a (specifically the Ppargc1a4 isoform, Smad4, Ltbp4, Bmpr1a, Crtc2, Xiap, Dgat1, Thra, Adrb2, Asb15, Cast, Eif2b5, Bdkrb2, Tpt1, Nr3c1, Nr4a1, Gnas, Pld1, Crym, Camkk1, Yap1, Inhba, Tp53inp2, Inhbb, Nol3, Esr1. Knock out, knock down, overexpression or a higher activity of these genes causes overall muscle hypertrophy as measured by an increased muscle weight or cross sectional area. The mean effect sizes range from 5 to 345% depending on the manipulated gene as well as the muscle size variable and muscle investigated. Bioinformatical analyses reveal that Asb15, Klf10, Tpt1 are most highly expressed hypertrophy genes in human skeletal muscle when compared to other tissues. Many of the muscle hypertrophy-regulating genes are involved in transcription and ubiquitination. Especially genes belonging to three signaling pathways are able to induce hypertrophy: (a Igf1-Akt-mTOR pathway, (b myostatin-Smad signaling, and (c the angiotensin-bradykinin signaling pathway. The expression of several muscle hypertrophy-inducing genes and the phosphorylation of their protein products changes after human resistance and high intensity exercise, in maximally stimulated mouse muscle or in overloaded mouse plantaris.

  13. Enhancement of Skeletal Muscle in Aged Rats Following High-Intensity Stretch-Shortening Contraction Training.

    Rader, Erik P; Naimo, Marshall A; Layner, Kayla N; Triscuit, Alyssa M; Chetlin, Robert D; Ensey, James; Baker, Brent A

    2017-04-01

    Exercise is the most accessible, efficacious, and multifactorial intervention to improve health and treat chronic disease. High-intensity resistance exercise, in particular, also maximizes skeletal muscle size and strength-outcomes crucial at advanced age. However, such training is capable of inducing muscle maladaptation when misapplied at old age. Therefore, characterization of parameters (e.g., mode and frequency) that foster adaptation is an active research area. To address this issue, we utilized a rodent model that allowed training at maximal intensity in terms of muscle activation and tested the hypothesis that muscles of old rats adapt to stretch-shortening contraction (SSC) training, provided the training frequency is sufficiently low. At termination of training, normalized muscle mass (i.e., muscle mass divided by tibia length) and muscle quality (isometric force divided by normalized muscle mass) were determined. For young rats, normalized muscle mass increased by ∼20% regardless of training frequency. No difference was observed for muscle quality values after 2 days versus 3 days per week training (0.65 ± 0.09 N/mg/mm vs. 0.59 ± 0.05 N/mg/mm, respectively). For old rats following 3 days per week training, normalized muscle mass was unaltered and muscle quality was 30% lower than young levels. Following 2 days per week training at old age, normalized muscle mass increased by 17% and muscle quality was restored to young levels. To investigate this enhanced response, oxidative stress was assessed by lipid peroxidation quantification. For young rats, lipid peroxidation levels were unaltered by training. With aging, baseline levels of lipid peroxidation increased by 1.5-fold. For old rats, only 2 days per week training decreased lipid peroxidation to levels indistinguishable from young values. These results imply that, appropriately scheduled high-intensity SSC training at old age is capable of restoring muscle to a younger phenotype in terms

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

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

    2017-01-01

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

  15. Bio-impedance analysis for appendicular skeletal muscle mass assessment in (pre-) frail elderly people

    Baar, van H.; Hulshof, P.J.M.; Tieland, C.A.B.; Groot, de C.P.G.M.

    2015-01-01

    Background & aims Screening populations for skeletal muscle mass (SMM) is important for early detection of sarcopenia. Our aim was to develop an age specific bio-impedance (BI) prediction equation for the assessment of appendicular skeletal muscle mass (ASMM) in (pre-) frail elderly people aged

  16. Depression Is Associated With Muscle Mass And Strength In Patients With End Stage Renal Disease

    Young Rim Song

    2012-06-01

    Full Text Available Depression is the most common psychiatric complication in patients with end-stage renal disease (ESRD. Sarcopenia, defined as loss of muscle mass and strength, is expected to be associated with depression, because both are closely linked to physical inactivity and functional impairment. We investigated the association of sarcopenia with depression in patients with ESRD. A total of 115 patients undergoing hemodialysis (HD were included in this study. Muscle mass was assessed by lean tissue index (LTI using portable whole body bioimpedance spectroscopy, and muscle strength was measured with handgrip strength (HGS. Depression was defined as Beck Depression Inventory-II (BDI-II score ≥16. About 60% of prevalent HD patients had depression. Compared to subjects without depression, depressed patients had a higher prevalence of sarcopenia (45.5 vs. 8.2%, p<0.001 and significantly increased serum IL-6 and hs-CRP level. However, (prealbumin and body mass index (BMI failed to correlate with BDI-II. HGS and LTI had a consistent negative effect on BDI-II even after adjusting other parameters including inflammation. In multivariate analysis, lower , increased IL-6 and β2-microglobulin,and sarcopenia were significant predictors for depression; sarcopenia was most powerful [odds ratio 9.01, 95% CI 3.60-12.22, p=0.001]. In conclusion, the prevalence of sarcopenia and depression was considerably high and and the presence of sarcopenia was an important predictor for depression.

  17. Does Skeletal Muscle Mass Influence Breast Cancer? Evaluating Mammary Tumorigenesis and Progression Genetically Hyper-Muscular Mice

    Zimmers, Teresa

    2006-01-01

    .... Mice lacking the skeletal muscle-specific muscle growth inhibitor myostatin and mice expressing a dominant negative form of the myostatin receptor, Activin Receptor Type IIB, display heightened muscle mass...

  18. Altered fibre types in gastrocnemius muscle of high wheel-running selected mice with mini-muscle phenotypes.

    Guderley, Helga; Joanisse, Denis R; Mokas, Sophie; Bilodeau, Geneviève M; Garland, Theodore

    2008-03-01

    Selective breeding of mice for high voluntary wheel running has favoured characteristics that facilitate sustained, aerobically supported activity, including a "mini-muscle" phenotype with markedly reduced hind limb muscle mass, increased mass-specific activities of oxidative enzymes, decreased % myosin heavy chain IIb, and, in the medial gastrocnemius, reduced twitch speed, reduced mass-specific isotonic power, and increased fatigue resistance. To evaluate whether selection has altered fibre type expression in mice with either "mini" or normal muscle phenotypes, we examined fibre types of red and white gastrocnemius. In both the medial and lateral gastrocnemius, the mini-phenotype increased activities of oxidative enzymes and decreased activities of glycolytic enzymes. In red muscle samples, the mini-phenotype markedly changed fibre types, with the % type I and type IIA fibres and the surface area of type IIA fibres increasing; in addition, mice from selected lines in general had an increased % type IIA fibres and larger type I fibres as compared with mice from control lines. White muscle samples from mini-mice showed dramatic structural alterations, with an atypical distribution of extremely small, unidentifiable fibres surrounded by larger, more oxidative fibres than normally present in white muscle. The increased proportion of oxidative fibres and these atypical small fibres together may explain the reduced mass and increased mitochondrial enzyme activities in mini-muscles. These and previous results demonstrate that extension of selective breeding beyond the time when the response of the selected trait (i.e. distance run) has levelled off can still modify the mechanistic underpinnings of this behaviour.

  19. Relationship of Muscle Mass Determined by DEXA with Spirometric Results in Healthy Individuals.

    Martín Holguera, Rafael; Turrión Nieves, Ana Isabel; Rodríguez Torres, Rosa; Alonso, María Concepción

    2017-07-01

    Muscle mass maybe a determining factor in the variability of spirometry results in individuals of the same sex and age who have similar anthropometric characteristics. The aim of this study was to determine the association between spirometric results from healthy individuals and their muscle mass assessed by dual energy X-ray absorptiometry (DEXA). A sample of 161 women and 144 men, all healthy non-smokers, was studied. Ages ranged from18 to77years. For each subject, spirometry results and total and regional lean mass values obtained by full body DEXA were recorded. A descriptive analysis of the variables and a regression analysis were performed to study the relationship between spirometric variables and lean body mass, correcting for age and body mass index (BMI). In both sexes all muscle mass variables correlated positively and significantly with spirometric variables, and to a greater extent in men. After partial adjustment of correlations by age and BMI, the factor which best explains the spirometric variables is the total lean body mass in men, and trunk lean body mass in women. In men, muscle mass in the lower extremities is most closely associated with spirometric results. In women, it is the muscle mass of the trunk. In both sexes muscle mass mainly affects FEV 1 . Copyright © 2016 SEPAR. Publicado por Elsevier España, S.L.U. All rights reserved.

  20. Development of a new screening method for the detection of antibiotic residues in muscle tissues using liquid chromatography and high resolution mass spectrometry with a LC-LTQ-Orbitrap instrument.

    2011-01-01

    Abstract In the present work, a liquid chromatography- high resolution mass spectrometry method was developed for the screening in meat of a wide range of antibiotics used in veterinary medicine. Full scan mode under high resolution mass spectral conditions using LTQ-Orbitrap mass spectrometer with resolving power 60.000 FWHM was applied for analysis of the samples. Samples were prepared using two extractions protocols prior to LC-MS analysis. The scope of the method focuses on the...

  1. Salmon Muscle Adherence to Polymer Coatings and Determination of Antibiotic Residues by Reversed-Phase High-Performance Liquid Chromatography Coupled to Selected Reaction Monitoring Mass Spectrometry, Atomic Force Microscopy, and Fourier Transform Infrared Spectroscopy

    E. Zumelzu

    2015-01-01

    Full Text Available The persistent adhesion of salmon muscle to food container walls after treatment with urea solution was observed. This work evaluated the diffusion of antibiotics from the salmon muscle to the polyethylene terephthalate (PET coating protecting the electrolytic chromium coated steel (ECCS plates. New aquaculture production systems employ antibiotics such as florfenicol, florfenicol amine, oxytetracycline, and erythromycin to control diseases. The introduction of antibiotics is a matter of concern regarding the effects on human health and biodiversity. It is important to determine their impact on the adhesion of postmortem salmon muscle to can walls and the surface and structural changes affecting the functionality of multilayers. This work characterized the changes occurring in the multilayer PET polymer and steel of containers by electron microscopy, 3D atomic force microscopy (3D-AFM, X-ray photoelectron spectroscopy (XPS, and Fourier transform infrared spectroscopy (FT-IR analyses. A robust mass spectrometry methodology was employed to determine the presence of antibiotic residues. No evidence of antibiotics was observed on the protective coating in the range between 0.001 and 2.0 ng/mL; however, the presence of proteins, cholesterol, and alpha-carotene was detected. This in-depth profiling of the matrix-level elements is relevant for the use of adequate materials in the canning export industry.

  2. Differences among skeletal muscle mass indices derived from height-, weight-, and body mass index-adjusted models in assessing sarcopenia

    Kim, Kyoung Min; Jang, Hak Chul; Lim, Soo

    2016-01-01

    Aging processes are inevitably accompanied by structural and functional changes in vital organs. Skeletal muscle, which accounts for 40% of total body weight, deteriorates quantitatively and qualitatively with aging. Skeletal muscle is known to play diverse crucial physical and metabolic roles in humans. Sarcopenia is a condition characterized by significant loss of muscle mass and strength. It is related to subsequent frailty and instability in the elderly population. Because muscle tissue is involved in multiple functions, sarcopenia is closely related to various adverse health outcomes. Along with increasing recognition of the clinical importance of sarcopenia, several international study groups have recently released their consensus on the definition and diagnosis of sarcopenia. In practical terms, various skeletal muscle mass indices have been suggested for assessing sarcopenia: appendicular skeletal muscle mass adjusted for height squared, weight, or body mass index. A different prevalence and different clinical implications of sarcopenia are highlighted by each definition. The discordances among these indices have emerged as an issue in defining sarcopenia, and a unifying definition for sarcopenia has not yet been attained. This review aims to compare these three operational definitions and to introduce an optimal skeletal muscle mass index that reflects the clinical implications of sarcopenia from a metabolic perspective. PMID:27334763

  3. Growth hormone mitigates loss of periosteal bone formation and muscle mass in disuse osteopenic rats

    Grubbe, M-C; Thomsen, Jesper Skovhus; Nyengaard, J R

    2014-01-01

    Growth hormone (GH) is a potent anabolic agent capable of increasing both bone and muscle mass. The aim was to investigate whether GH could counteract disuse-induced loss of bone and muscle mass in a rat model. Paralysis was induced by injecting 4 IU Botox (BTX) into the muscles of the right hind...... of periosteal BFR/BS (2-fold increase vs. BTX, Pmuscle mass (+29% vs. BTX, Pmuscle CSA (+11%, P=0.064). In conclusion, GH mitigates disuse......BMD, -13%, Pmuscle mass (-69%, Pmuscle cell cross sectional area (CSA) (-73%, P

  4. mTOR as a Key Regulator in Maintaining Skeletal Muscle Mass

    Mee-Sup Yoon

    2017-10-01

    Full Text Available Maintenance of skeletal muscle mass is regulated by the balance between anabolic and catabolic processes. Mammalian target of rapamycin (mTOR is an evolutionarily conserved serine/threonine kinase, and is known to play vital roles in protein synthesis. Recent findings have continued to refine our understanding of the function of mTOR in maintaining skeletal muscle mass. mTOR controls the anabolic and catabolic signaling of skeletal muscle mass, resulting in the modulation of muscle hypertrophy and muscle wastage. This review will highlight the fundamental role of mTOR in skeletal muscle growth by summarizing the phenotype of skeletal-specific mTOR deficiency. In addition, the evidence that mTOR is a dual regulator of anabolism and catabolism in skeletal muscle mass will be discussed. A full understanding of mTOR signaling in the maintenance of skeletal muscle mass could help to develop mTOR-targeted therapeutics to prevent muscle wasting.

  5. Associations between lower extremity muscle mass and metabolic parameters related to obesity in Japanese obese patients with type 2 diabetes

    Hidetaka Hamasaki

    2015-05-01

    Full Text Available Background. Age-related loss of muscle mass (sarcopenia increases the incidence of obesity in the elderly by reducing physical activity. This sarcopenic obesity may become self-perpetuating, increasing the risks for metabolic syndrome, disability, and mortality. We investigated the associations of two sarcopenic indices, the ratio of lower extremity muscle mass to body weight (L/W ratio and the ratio of lower extremity muscle mass to upper extremity muscle mass (L/U ratio, with metabolic parameters related to obesity in patients with type 2 diabetes and obesity.Methods. Of 148 inpatients with type 2 diabetes treated between October 2013 and April 2014, we recruited 26 with obesity but no physical disability. Daily physical activity was measured by a triaxial accelerometer during a period of hospitalization, and which was also evaluated by our previously reported non-exercise activity thermogenesis questionnaire. We measured body composition by bioelectrical impedance and investigated the correlations of L/W and L/U ratios with body weight, body mass index (BMI, waist circumference (WC, waist-to-hip ratio (WHR, visceral fat area, subcutaneous fat area, serum lipid profile, and daily physical activity.Results. The L/W ratio was significantly and negatively correlated with BMI, WC, WHR, body fat mass, body fat percentage, subcutaneous fat area, and serum free fatty acid concentration, was positively correlated with daily physical activity: the locomotive non-exercise activity thermogenesis score, but was not correlated with visceral fat area. The L/U ratio was significantly and positively correlated with serum high-density lipoprotein cholesterol.Conclusions. High L/W and L/U ratios, indicative of relatively preserved lower extremity muscle mass, were predictive of improved metabolic parameters related to obesity. Preserved muscle fitness in obesity, especially of the lower extremities, may prevent sarcopenic obesity and lower associated risks for

  6. Changes in lower limb muscle function and muscle mass following exercise-based interventions in patients with chronic obstructive pulmonary disease: A review of the English-language literature.

    De Brandt, Jana; Spruit, Martijn A; Hansen, Dominique; Franssen, Frits Me; Derave, Wim; Sillen, Maurice Jh; Burtin, Chris

    2018-05-01

    Chronic obstructive pulmonary disease (COPD) patients often experience lower limb muscle dysfunction and wasting. Exercise-based training has potential to improve muscle function and mass, but literature on this topic is extensive and heterogeneous including numerous interventions and outcome measures. This review uses a detailed systematic approach to investigate the effect of this wide range of exercise-based interventions on muscle function and mass. PUBMED and PEDro databases were searched. In all, 70 studies ( n = 2504 COPD patients) that implemented an exercise-based intervention and reported muscle strength, endurance, or mass in clinically stable COPD patients were critically appraised. Aerobic and/or resistance training, high-intensity interval training, electrical or magnetic muscle stimulation, whole-body vibration, and water-based training were investigated. Muscle strength increased in 78%, muscle endurance in 92%, and muscle mass in 88% of the cases where that specific outcome was measured. Despite large heterogeneity in exercise-based interventions and outcome measures used, most exercise-based trials showed improvements in muscle strength, endurance, and mass in COPD patients. Which intervention(s) is (are) best for which subgroup of patients remains currently unknown. Furthermore, this literature review identifies gaps in the current knowledge and generates recommendations for future research to enhance our knowledge on exercise-based interventions in COPD patients.

  7. Subclinical hypothyroidism has little influences on muscle mass or strength in elderly people.

    Moon, Min Kyong; Lee, You Jin; Choi, Sung Hee; Lim, Soo; Yang, Eun Joo; Lim, Jae-Young; Paik, Nam-Jong; Kim, Ki Woong; Park, Kyong Soo; Jang, Hak C; Cho, Bo Youn; Park, Young Joo

    2010-08-01

    Sarcopenia, the age-related decline in muscle mass, affects the muscle strength and muscle quality, and these changes decrease functional capacity. The prevalence of thyroid dysfunction increases with age, and changes in thyroid hormone level lead to neuromuscular deficits. We investigated the effects of subclinical hypothyroidism on the muscle mass, strength or quality in elderly people. One thousand one hundred eighteen subjects aged > or = 65 yr were randomly selected from a local population and classified into a euthyroid (280 men and 358 women), subclinically hypothyroid (61 men and 75 women), or overtly hypothyroid (7 men and 16 women) group. Although women with subclinical hypothyroidism had a higher prevalence of sarcopenia, defined according to the ratio of appendicular skeletal muscle mass to the square of height, muscle mass, strength or quality did not differ in relation to thyroid status in men or in women. Multivariate analysis including age, diabetes, hypertension, acute coronary event, alcohol, smoking, presence of pain, physical activity score, and lipid profile, showed that thyroid-stimulating hormone level was not associated with muscle mass, strength or quality. In conclusion, subclinical hypothyroidism has little influences on muscle mass, strength or quality, and may not be associated with sarcopenia.

  8. Osteocalcin is necessary and sufficient to maintain muscle mass in older mice

    Paula Mera

    2016-10-01

    Full Text Available Objective: A decrease in muscle protein turnover and therefore in muscle mass is a hallmark of aging. Because the circulating levels of the bone-derived hormone osteocalcin decline steeply during aging in mice, monkeys and humans we asked here whether this hormone might regulate muscle mass as mice age. Methods: We examined muscle mass and strength in mice lacking osteocalcin (Ocn−/− or its receptor in all cells (Gprc6a−/− or specifically in myofibers (Gprc6aMck−/− as well as in 9 month-old WT mice receiving exogenous osteocalcin for 28 days. We also examined protein synthesis in WT and Gprc6a−/− mouse myotubes treated with osteocalcin. Results: We show that osteocalcin signaling in myofibers is necessary to maintain muscle mass in older mice in part because it promotes protein synthesis in myotubes without affecting protein breakdown. We further show that treatment with exogenous osteocalcin for 28 days is sufficient to increase muscle mass of 9-month-old WT mice. Conclusion: This study uncovers that osteocalcin is necessary and sufficient to prevent age-related muscle loss in mice. Author Video: Author Video Watch what authors say about their articles Keywords: Osteocalcin, Muscle mass, Aging

  9. Improved skeletal muscle mass and strength after heavy strength training in very old individuals

    Bechshøft, Rasmus Leidesdorff; Malmgaard-Clausen, Nikolaj Mølkjær; Gliese, Bjørn

    2017-01-01

    , muscle fiber type distribution and size did not differ significantly between groups. We conclude that in protein supplemented very old individuals, heavy resistance training can increase muscle mass and strength, and that the relative improvement in mass is more pronounced when initial muscle mass is low.......Age-related loss of muscle mass and function represents personal and socioeconomic challenges. The purpose of this study was to determine the adaptation of skeletal musculature in very old individuals (83 + years) performing 12 weeks of heavy resistance training (3 ×/week) (HRT) compared to a non....... The increase in CSA is correlated inversely with the baseline level of CSA (R2 = 0.43, P muscle isometric strength, isokinetic peak torque and power increased significantly only in HRT by 10–15%, whereas knee extension one-repetition maximum (1 RM) improved by 91%. Physical functional tests...

  10. High mass planets and low mass stars

    Stevenson, D.J.

    1986-01-01

    The paper on theoretical models of brown dwarf stars was presented to the workshop on ''Astrophysics of brown dwarfs'', Virginia, USA, 1985. The ingredients in the models i.e. equation of state, entropy and the infrared opacity are described. An analytical model is developed which is based on a polytrope (n = 3/4) but which neglects thermonuclear reactions. The model forms the basis of scaling laws for luminosity, mass, opacity and age. Complicating factors in brown dwarf evolution are also discussed. (U.K.)

  11. Skeletal muscle mass recovery from atrophy in IL-6 knockout mice.

    Washington, T A; White, J P; Davis, J M; Wilson, L B; Lowe, L L; Sato, S; Carson, J A

    2011-08-01

    Skeletal muscle interleukin-6 (IL-6) expression is induced by continuous contraction, overload-induced hypertrophy and during muscle regeneration. The loss of IL-6 can alter skeletal muscle's growth and extracellular matrix remodelling response to overload-induced hypertrophy. Insulin-like growth factor-1 (IGF-1) gene expression and related signalling through Akt/mTOR is a critical regulator of muscle mass. The significance of IL-6 expression during the recovery from muscle atrophy is unclear. This study's purpose was to determine the effect of IL-6 loss on mouse gastrocnemius (GAS) muscle mass during recovery from hindlimb suspension (HS)-induced atrophy. Female C57BL/6 [wild type (WT)] and IL-6 knockout (IL-6 KO) mice at 10 weeks of age were assigned to control, HS or HS followed by normal cage ambulation groups. GAS muscle atrophy was induced by 10 days of HS. HS induced a 20% loss of GAS mass in both WT and IL-6 KO mice. HS+7 days of recovery restored WT GAS mass to cage-control values. GAS mass from IL-6 KO mice did not return to cage-control values until HS+14 days of recovery. Both IGF-1 mRNA expression and Akt/mTOR signalling were increased in WT muscle after 1 day of recovery. In IL-6 KO muscle, IGF-1 mRNA expression was decreased and Akt/mTOR signalling was not induced after 1 day of recovery. MyoD and myogenin mRNA expression were both induced in WT muscle after 1 day of recovery, but not in IL-6 KO muscle.   Muscle IL-6 expression appears important for the initial growth response during the recovery from disuse. © 2011 The Authors. Acta Physiologica © 2011 Scandinavian Physiological Society.

  12. Relation between body mass index percentile and muscle strength ...

    Noha Abdel Kader Abdel Kader Hasan

    2016-02-01

    Feb 1, 2016 ... Abstract Background: Muscle strength and endurance in children are very important to develop physical .... the Faculty of Physical Therapy, Cairo university, was used to ..... [9] Noelle G. Quantification of muscle fatigue in cerebral palsy and ... Bouckaert J. Physical fitness and physical activity in obese and.

  13. Association between healthy diet and exercise and greater muscle mass in older adults.

    Kim, Jinhee; Lee, Yunhwan; Kye, Seunghee; Chung, Yoon-Sok; Kim, Kwang-Min

    2015-05-01

    To examine the association between healthy diet and exercise, individually and combined, and low muscle mass in older Korean adults. Population-based cross-sectional study from the Fourth and Fifth Korea National Health and Nutrition Examination Surveys from 2008 to 2011. Community. Nationally representative sample aged 65 and older (1,486 men, 1,799 women) in the Republic of Korea. A food frequency questionnaire was used to determine frequency of food group consumption (meat, fish, eggs, legumes; vegetables; fruits). Participation in exercise (aerobic and resistance) was based on self-report. Combined healthy lifestyle factors were calculated as the number of recommendations met regarding consumption of food groups and exercise performed. Appendicular skeletal muscle mass (ASM) was measured using dual-energy X-ray absorptiometry, and low muscle mass was defined using the variable of ASM adjusted for weight. Logistic regression analysis was performed to examine the association between healthy lifestyle factors and low muscle mass, adjusting for sociodemographic characteristics and health-related variables. In women, after controlling for covariates, vegetable consumption (odds ratio (OR)=0.52, 95% confidence interval (CI)=0.30-0.89) and aerobic exercise (OR=0.62, 95% CI=0.39-1.00) were inversely associated with low muscle mass. Also, the odds of low muscle mass was lower in women with three or more healthy lifestyle factors versus none (OR=0.45, 95% CI=0.23-0.87). In men, there were no associations between food group consumption and exercise and low muscle mass. Older women who exercise and consume a healthy diet have lower odds of low muscle mass. Engaging in multiple healthy behaviors may be important in preventing low muscle mass in late life. © 2015, Copyright the Authors Journal compilation © 2015, The American Geriatrics Society.

  14. Decreased muscle mass in Korean subjects with intracranial arterial stenosis: The Kangbuk Samsung Health Study.

    Jung, Ho-Jung; Jung, Hwanseok; Lee, Taeyoung; Kim, Jongho; Park, Jongsin; Kim, Hacsoo; Cho, Junghwan; Lee, Won-Young; Park, Sung-Woo; Rhee, Eun-Jung; Oh, Hyung-Geun

    2017-01-01

    Intracranial arterial stenosis (ICAS) is a common cause of ischemic stroke in Asians. Decreased muscle mass is one of the major causes of chronic disease in adults. The purpose of this study was to analyze the relationship between muscle mass and ICAS in Korean adults. For this study, we selected a total of 10,530 participants (mean age, 43.3 years; 8558 men) in a health screening program, for whom transcranial Doppler (TCD) ultrasound was used to detect >50% ICAS based on criteria modified from the stroke outcomes and neuroimaging of intracranial atherosclerosis trial. Body composition was evaluated by bioelectrical impedance analysis (BIA). Skeletal muscle index (SMI) was calculated with muscle mass/weight (kg) * 100. Among the total patient population, 322 (3.1%) subjects had ICAS. Subjects with ICAS were older, and had higher mean values for fasting glucose, body mass index and blood pressure compared with those without ICAS. Subjects with ICAS had significantly lower muscle mass, SMI and higher percent body fat compared with those without ICAS. In logistic regression analysis, the subjects in the highest tertile of muscle mass had the lowest odds ratio for ICAS with the lowest tertile group of muscle mass as the reference group even after adjusting for age, systolic blood pressure, fasting blood glucose, sex, smoking and exercise (OR 0.650, 95% CI 0.442-0.955). Subjects with ICAS had significantly decreased muscle mass compared with those without ICAS in Korean adults. The risk for ICAS was lower in subjects with higher muscle mass. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  15. Low skeletal muscle mass outperforms the Charlson Comorbidity Index in risk prediction in patients undergoing pancreatic resections.

    Wagner, D; Marsoner, K; Tomberger, A; Haybaeck, J; Haas, J; Werkgartner, G; Cerwenka, H; Bacher, H; Mischinger, H J; Kornprat, P

    2018-05-01

    Low skeletal muscle mass is a known predictor of morbidity and mortality in patients undergoing major pancreatic surgeries. We sought to combine low skeletal muscle mass with established risk predictors to improve their prognostic capacity for postoperative outcome and morbidity. As established parameters to predict preoperative mortality risk for patients, the ASA classification and the Charlson Comorbidity Index (CCI) were used. The Hounsfield Units Average Calculation (HUAC) was measured to define low skeletal muscle mass in 424 patients undergoing pancreatic resections for malignancies. Patients in the lowest sex-adjusted quartile for HUAC were defined as having low skeletal muscle mass (muscle wasting). Multivariable Cox regression analysis was utilized to identify preoperative risk factors associated with postoperative morbidity. Median patient age was 63 years (19-87), 47.9% patients were male, and half the cohort had multiple comorbidities (Charlson Comorbidity Index [CCI]>6, 63.2%), 30-day mortality was 5.8% (n = 25). Median HUAC was 19.78 HU (IQR: 15.94-23.54) with 145 patients (34.2%) having low skeletal muscle mass. Preoperative frailty defined by low skeletal muscle mass was associated with an increased risk for postoperative complications (OR 1.55, CI 95% 0.98-2.45, p = 0.014), and a higher 30-day mortality (HR 5.17, CI 95% 1.57-16.69, p = 0.004). With an AUC of 0.85 HUAC showed the highest predictability for 30-day mortality (CI 95% 0.78-0.91, p = 0.0001). Patients with CCI ≥6 and low skeletal muscle mass defined by the HUAC had a 9.78 higher risk of dying in the immediate postoperative phase (HR 9.78, CI 95% 2.98-12.2, p = 0.0001). Low skeletal muscle mass predicts postoperative mortality and complications best and it should be incorporated to conventional risk scores to identify high risk patients. Copyright © 2018 Elsevier Ltd, BASO ~ The Association for Cancer Surgery, and the European Society of Surgical Oncology. All rights

  16. Low muscle mass is associated with metabolic syndrome only in nonobese young adults: the Korea National Health and Nutrition Examination Survey 2008-2010.

    Kim, Byung Chul; Kim, Mee Kyoung; Han, Kyungdo; Lee, Sae-Young; Lee, Seung-Hwan; Ko, Seung-Hyun; Kwon, Hyuk-Sang; Merchant, Anwar T; Yim, Hyeon Woo; Lee, Won-Chul; Park, Yong Gyu; Park, Yong-Moon

    2015-12-01

    Little is known about the relationship between body composition and metabolic risk factors in young adults. We hypothesized that low muscle mass (LMM) is associated with metabolic syndrome (MetS) and its components in young adults and that the associations vary by obesity. A cross-sectional analysis was conducted using the Korea National Health and Nutrition Examination Survey data. In total, 5300 young adults aged 19 to 39 years were evaluated. Low muscle mass was defined as an appendicular skeletal muscle mass/weight less than 1 SD below the mean for each participant's corresponding sex and age group. Obesity was defined as a body mass index greater than or equal to 25 kg/m2. The prevalence of LMM was higher in obese than nonobese participants (37.6% vs. 9.6%). In the nonobese participants, the prevalence of MetS, high waist circumference, high triglycerides, and high blood pressure was significantly greater in the LMM group than in the high muscle mass group. In the nonobese group, compared with high muscle mass participants, those with LMM had odds ratios for MetS of 3.6 (95% confidence interval, 1.48-8.76; P young adults with LMM may have a high risk of MetS, especially when they are nonobese. Interventions aimed at increasing muscle mass at younger ages may have the potential to reduce MetS. Published by Elsevier Inc.

  17. Normal Weight but Low Muscle Mass and Abdominally Obese: Implications for the Cardiometabolic Risk Profile in Chronic Obstructive Pulmonary Disease.

    Beijers, Rosanne J H C G; van de Bool, Coby; van den Borst, Bram; Franssen, Frits M E; Wouters, Emiel F M; Schols, Annemie M W J

    2017-06-01

    It is well established that low muscle mass affects physical performance in chronic obstructive pulmonary disease (COPD). We hypothesize that combined low muscle mass and abdominal obesity may also adversely influence the cardiometabolic risk profile in COPD, even in those with normal weight. The cardiometabolic risk profile and the responsiveness to 4 months high-intensity exercise training was assessed in normal-weight patients with COPD with low muscle mass stratified by abdominal obesity. This is a cross-sectional study including 81 clinically stable patients with COPD (age 62.5 ± 8.2 years; 50.6% males; forced expiratory volume in 1 second 55.1 ± 19.5 percentage predicted) with fat-free mass index risk profile. Triglycerides showed a significant decrease, while the HOMA-IR increased. Abdominal obesity is highly prevalent in normal-weight patients with COPD with low muscle mass who showed an increased cardiometabolic risk compared with patients without abdominal obesity. This cardiometabolic risk profile was not altered after 4 months of exercise training. Copyright © 2017 AMDA – The Society for Post-Acute and Long-Term Care Medicine. Published by Elsevier Inc. All rights reserved.

  18. Sarcopenia and Predictors of Skeletal Muscle Mass in Elderly Men With and Without Obesity

    Katja Stoever MA

    2017-06-01

    Full Text Available Objectives: The aim of this study was to determine the variables which show the highest association with muscle mass and to identify the most important predictors for muscle mass in elderly men with and without sarcopenia. Methods: A total of 71 men participated, aged ≥65 years. Sarcopenia was assessed using the definition of the European Working Group on Sarcopenia in Older People with determining skeletal muscle index (SMI, hand-grip strength (HGS, and Short Physical Performance Battery. In addition, maximum strength at upper and lower extremities and physical activity were measured. Results: Strong correlations existed between SMI and gait speed, HGS, maximum isometric strength at leg and chest press. Physical activity showed low correlations with muscle strength. Regression analysis revealed HGS and gait speed as key predictors for SMI. Discussion: The recommendation is measuring gait speed and HGS in clinical practice at first followed by measuring muscle mass for determining sarcopenia.

  19. Delayed recovery of skeletal muscle mass following hindlimb immobilization in mTOR heterozygous mice.

    Susan M Lang

    Full Text Available The present study addressed the hypothesis that reducing mTOR, as seen in mTOR heterozygous (+/- mice, would exaggerate the changes in protein synthesis and degradation observed during hindlimb immobilization as well as impair normal muscle regrowth during the recovery period. Atrophy was produced by unilateral hindlimb immobilization and data compared to the contralateral gastrocnemius. In wild-type (WT mice, the gradual loss of muscle mass plateaued by day 7. This response was associated with a reduction in basal protein synthesis and development of leucine resistance. Proteasome activity was consistently elevated, but atrogin-1 and MuRF1 mRNAs were only transiently increased returning to basal values by day 7. When assessed 7 days after immobilization, the decreased muscle mass and protein synthesis and increased proteasome activity did not differ between WT and mTOR(+/- mice. Moreover, the muscle inflammatory cytokine response did not differ between groups. After 10 days of recovery, WT mice showed no decrement in muscle mass, and this accretion resulted from a sustained increase in protein synthesis and a normalization of proteasome activity. In contrast, mTOR(+/- mice failed to fully replete muscle mass at this time, a defect caused by the lack of a compensatory increase in protein synthesis. The delayed muscle regrowth of the previously immobilized muscle in the mTOR(+/- mice was associated with a decreased raptor•4EBP1 and increased raptor•Deptor binding. Slowed regrowth was also associated with a sustained inflammatory response (e.g., increased TNFα and CD45 mRNA during the recovery period and a failure of IGF-I to increase as in WT mice. These data suggest mTOR is relatively more important in regulating the accretion of muscle mass during recovery than the loss of muscle during the atrophy phase, and that protein synthesis is more sensitive than degradation to the reduction in mTOR during muscle regrowth.

  20. Delayed recovery of skeletal muscle mass following hindlimb immobilization in mTOR heterozygous mice.

    Lang, Susan M; Kazi, Abid A; Hong-Brown, Ly; Lang, Charles H

    2012-01-01

    The present study addressed the hypothesis that reducing mTOR, as seen in mTOR heterozygous (+/-) mice, would exaggerate the changes in protein synthesis and degradation observed during hindlimb immobilization as well as impair normal muscle regrowth during the recovery period. Atrophy was produced by unilateral hindlimb immobilization and data compared to the contralateral gastrocnemius. In wild-type (WT) mice, the gradual loss of muscle mass plateaued by day 7. This response was associated with a reduction in basal protein synthesis and development of leucine resistance. Proteasome activity was consistently elevated, but atrogin-1 and MuRF1 mRNAs were only transiently increased returning to basal values by day 7. When assessed 7 days after immobilization, the decreased muscle mass and protein synthesis and increased proteasome activity did not differ between WT and mTOR(+/-) mice. Moreover, the muscle inflammatory cytokine response did not differ between groups. After 10 days of recovery, WT mice showed no decrement in muscle mass, and this accretion resulted from a sustained increase in protein synthesis and a normalization of proteasome activity. In contrast, mTOR(+/-) mice failed to fully replete muscle mass at this time, a defect caused by the lack of a compensatory increase in protein synthesis. The delayed muscle regrowth of the previously immobilized muscle in the mTOR(+/-) mice was associated with a decreased raptor•4EBP1 and increased raptor•Deptor binding. Slowed regrowth was also associated with a sustained inflammatory response (e.g., increased TNFα and CD45 mRNA) during the recovery period and a failure of IGF-I to increase as in WT mice. These data suggest mTOR is relatively more important in regulating the accretion of muscle mass during recovery than the loss of muscle during the atrophy phase, and that protein synthesis is more sensitive than degradation to the reduction in mTOR during muscle regrowth.

  1. Circulating levels of TNF-alpha and IL-6-relation to truncal fat mass and muscle mass in healthy elderly individuals and in patients with type-2 diabetes

    Pedersen, Maria; Bruunsgaard, Helle; Weis, Nina

    2003-01-01

    The purpose of the current study was to test the hypothesis that an altered fat distribution in elderly healthy subjects and in patients with type-2 diabetes contributes to high circulating levels of interleukin (IL)-6 and tumor necrotic factor (TNF)-alpha, which secondly is related to lower muscle...... mass. Twenty young controls, (20-35 yr), 20 healthy elderly subjects (65-80 yr) and 16 elderly patients with type 2 diabetes (65-80 yr) were included in a cross sectional study. Plasma levels of TNF-alpha and IL-6 were measured after an overnight fast. Dual-energy X-ray absorptiometry and total body...... potassium counting measured truncal fat, appendicular skeletal muscle mass (ASM) and body cell mass (BCM), respectively. TNF-alpha, IL-6 and the relative truncal fat mass were higher in elderly compared with young controls. ASM was lower in diabetic men than in young controls and BCM was lower in elderly...

  2. Phenotype selection reveals coevolution of muscle glycogen and protein and PTEN as a gate keeper for the accretion of muscle mass in adult female mice.

    Mandy Sawitzky

    Full Text Available We have investigated molecular mechanisms for muscle mass accretion in a non-inbred mouse model (DU6P mice characterized by extreme muscle mass. This extreme muscle mass was developed during 138 generations of phenotype selection for high protein content. Due to the repeated trait selection a complex setting of different mechanisms was expected to be enriched during the selection experiment. In muscle from 29-week female DU6P mice we have identified robust increases of protein kinase B activation (AKT, Ser-473, up to 2-fold if compared to 11- and 54-week DU6P mice or controls. While a number of accepted effectors of AKT activation, including IGF-I, IGF-II, insulin/IGF-receptor, myostatin or integrin-linked kinase (ILK, were not correlated with this increase, phosphatase and tensin homologue deleted on chromosome 10 (PTEN was down-regulated in 29-week female DU6P mice. In addition, higher levels of PTEN phosphorylation were found identifying a second mechanism of PTEN inhibition. Inhibition of PTEN and activation of AKT correlated with specific activation of p70S6 kinase and ribosomal protein S6, reduced phosphorylation of eukaryotic initiation factor 2α (eIF2α and higher rates of protein synthesis in 29-week female DU6P mice. On the other hand, AKT activation also translated into specific inactivation of glycogen synthase kinase 3ß (GSK3ß and an increase of muscular glycogen. In muscles from 29-week female DU6P mice a significant increase of protein/DNA was identified, which was not due to a reduction of protein breakdown or to specific increases of translation initiation. Instead our data support the conclusion that a higher rate of protein translation is contributing to the higher muscle mass in mid-aged female DU6P mice. Our results further reveal coevolution of high protein and high glycogen content during the selection experiment and identify PTEN as gate keeper for muscle mass in mid-aged female DU6P mice.

  3. Deficits in muscle strength, mass, quality and mobility in people with chronic obstructive pulmonary disease

    Roig, Marc; Eng, Janice J; MacIntyre, Donna L

    2011-01-01

    PURPOSE: Midthigh intramuscular fat (IF), a feature of reduced muscle quality, is an important predictor of self-reported mobility loss in the elderly. This study compared measures of muscle strength, mass, IF, and mobility in patients with chronic obstructive pulmonary disease (COPD) and healthy...

  4. Levator claviculae muscle presenting as a hard clavicular mass: imaging study

    Ruiz Santiago, F.; Lopez Milena, G.; Tristan Fernandez, J.M.; Chamorro Santos, C.

    2001-01-01

    We report a case of levator claviculae muscle presenting clinically as a hard mass in the clavicular area due to angular deformity of this bone. To our knowledge, this is the first report where the anomalous muscle shows this clinical presentation. (orig.)

  5. Alterations in molecular muscle mass regulators after 8 days immobilizing Special Forces mission

    Jespersen, J. G.; Mikkelsen, Ulla Ramer; Nedergaard, A.

    2015-01-01

    In military operations, declined physical capacity can endanger the life of soldiers. During special support and reconnaissance (SSR) missions, Special Forces soldiers sustain 1-2 weeks full-body horizontal immobilization, which impairs muscle strength and performance. Adequate muscle mass and st...

  6. Immobilization/remobilization and the regulation of muscle mass

    Almon, R. R.

    1983-01-01

    The relationship between animal body weight and the wet and dry weights of the soleus and EDL muscles was derived. Procedures were examined for tissue homogenization, fractionation, protein determination and DNA determination. A sequence of procedures and buffers were developed to carry out all analyses on one small muscle. This would yield a considerable increase in analytical strength associated with paired statistics. The proposed casting procedure which was to be used for immobilization was reexamined.

  7. The Impact of Low Muscle Mass Definition on the Prevalence of Sarcopenia in Older Australians

    Solomon Yu

    2014-01-01

    Full Text Available Background. Sarcopenia is the presence of low muscle mass and low muscle function. The aim of this study was to establish cutoffs for low muscle mass using three published methods and to compare the prevalence of sarcopenia in older Australians. Methods. Gender specific cutoffs levels were identified for low muscle mass using three different methods. Low grip strength was determined using established cutoffs of <30 kg for men and <20 kg for women to estimate the prevalence of sarcopenia. Results. Gender specific cutoffs levels for low muscle mass identified were (a <6.89 kg/m2 for men and <4.32 kg/m2 for women, <2 standard deviation (SD of a young reference population; (b <7.36 kg/m2 for men and <5.81 kg/m2 for women from the lowest 20% percentile of the older group; and (c <−2.15 for men and <−1.42 for women from the lowest 20% of the residuals of linear regressions of appendicular skeletal mass, adjusted for fat mass and height. Prevalence of sarcopenia in older (65 years and older people by these three methods for men was 2.5%, 6.2%, and 6.4% and for women 0.3%, 9.3%, and 8.5%, respectively. Conclusions. Sarcopenia is common but consensus on the best method to confirm low muscle mass is required.

  8. Adiposity, muscle mass and muscle strength in relation to functional decline in older persons.

    Schaap, L.A.; Koster, A.; Visser, M.

    2013-01-01

    Aging is associated with changes in body composition and muscle strength. This review aimed to determine the relation between different body composition measures and muscle strength measures and functional decline in older men and women. By use of relevant databases (PubMed, Embase, and CINAHL) and

  9. Increasing Muscle Mass Improves Vascular Function in Obese (db/db) Mice

    Qiu, Shuiqing; Mintz, James D.; Salet, Christina D.; Han, Weihong; Giannis, Athanassios; Chen, Feng; Yu, Yanfang; Su, Yunchao; Fulton, David J.; Stepp, David W.

    2014-01-01

    Background A sedentary lifestyle is an independent risk factor for cardiovascular disease and exercise has been shown to ameliorate this risk. Inactivity is associated with a loss of muscle mass, which is also reversed with isometric exercise training. The relationship between muscle mass and vascular function is poorly defined. The aims of the current study were to determine whether increasing muscle mass by genetic deletion of myostatin, a negative regulator of muscle growth, can influence vascular function in mesenteric arteries from obese db/db mice. Methods and Results Myostatin expression was elevated in skeletal muscle of obese mice and associated with reduced muscle mass (30% to 50%). Myostatin deletion increased muscle mass in lean (40% to 60%) and obese (80% to 115%) mice through increased muscle fiber size (PMyostatin deletion decreased adipose tissue in lean mice, but not obese mice. Markers of insulin resistance and glucose tolerance were improved in obese myostatin knockout mice. Obese mice demonstrated an impaired endothelial vasodilation, compared to lean mice. This impairment was improved by superoxide dismutase mimic Tempol. Deletion of myostatin improved endothelial vasodilation in mesenteric arteries in obese, but not in lean, mice. This improvement was blunted by nitric oxide (NO) synthase inhibitor l‐NG‐nitroarginine methyl ester (l‐NAME). Prostacyclin (PGI2)‐ and endothelium‐derived hyperpolarizing factor (EDHF)‐mediated vasodilation were preserved in obese mice and unaffected by myostatin deletion. Reactive oxygen species) was elevated in the mesenteric endothelium of obese mice and down‐regulated by deletion of myostatin in obese mice. Impaired vasodilation in obese mice was improved by NADPH oxidase inhibitor (GKT136901). Treatment with sepiapterin, which increases levels of tetrahydrobiopterin, improved vasodilation in obese mice, an improvement blocked by l‐NAME. Conclusions Increasing muscle mass by genetic deletion of

  10. The influence of different muscle mass measurements on the diagnosis of cancer cachexia.

    Blauwhoff-Buskermolen, Susanne; Langius, Jacqueline A E; Becker, Annemarie; Verheul, Henk M W; de van der Schueren, Marian A E

    2017-08-01

    Progressive loss of muscle mass is a major characteristic of cancer cachexia. Consensus definitions for cachexia provide different options to measure muscle mass. This study describes the effect of different methods to determine muscle mass on the diagnosis of cancer cachexia. In addition, the association of cachexia with other features of cachexia, quality of life, and survival was explored. Prior to chemotherapy, cachexia was assessed by weight loss, body mass index, and muscle mass measurements, the latter by mid-upper arm muscle area (MUAMA), computed tomography (CT) scans, and bio-electrical impedance analysis (BIA). In addition, appetite, inflammation, muscle strength, fatigue, quality of life, and survival were measured, and associations with cachexia were explored. Included were 241 patients with advanced cancer of the lung (36%), colon/rectum (31%), prostate (18%), or breast (15%). Mean age was 64 ± 10 years; 54% was male. Prevalence of low muscle mass was as follows: 13% with MUAMA, 59% with CT, and 93% with BIA. In turn, the prevalence of cachexia was 37, 43, and 48%, whereby weight loss >5% was the most prominent component of being defined cachectic. Irrespective of type of muscle measurement, patients with cachexia presented more often with anorexia, inflammation, low muscle strength, and fatigue and had lower quality of life. Patients with cachexia had worse overall survival compared with patients without cachexia: HRs 2.00 (1.42-2.83) with MUAMA, 1.64 (1.15-2.34) with CT, and 1.50 (1.05-2.14) with BIA. Although the prevalence of low muscle mass in patients with cancer depended largely on the type of muscle measurement, this had little influence on the diagnosis of cancer cachexia (as the majority of patients was already defined cachectic based on weight loss). New studies are warranted to further elucidate the additional role of muscle measurements in the diagnosis of cachexia and the association with clinical outcomes. © 2017 The Authors

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

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

    2014-01-01

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

  12. Genetic variations in the androgen receptor are associated with steroid concentrations and anthropometrics but not with muscle mass in healthy young men.

    Hélène De Naeyer

    Full Text Available OBJECTIVE: The relationship between serum testosterone (T levels, muscle mass and muscle force in eugonadal men is incompletely understood. As polymorphisms in the androgen receptor (AR gene cause differences in androgen sensitivity, no straightforward correlation can be observed between the interindividual variation in T levels and different phenotypes. Therefore, we aim to investigate the relationship between genetic variations in the AR, circulating androgens and muscle mass and function in young healthy male siblings. DESIGN: 677 men (25-45 years were recruited in a cross-sectional, population-based sibling pair study. METHODS: Relations between genetic variation in the AR gene (CAGn, GGNn, SNPs, sex steroid levels (by LC-MS/MS, body composition (by DXA, muscle cross-sectional area (CSA (by pQCT, muscle force (isokinetic peak torque, grip strength and anthropometrics were studied using linear mixed-effect modelling. RESULTS: Muscle mass and force were highly heritable and related to age, physical activity, body composition and anthropometrics. Total T (TT and free T (FT levels were positively related to muscle CSA, whereas estradiol (E2 and free E2 (FE2 concentrations were negatively associated with muscle force. Subjects with longer CAG repeat length had higher circulating TT, FT, and higher E2 and FE2 concentrations. Weak associations with TT and FT were found for the rs5965433 and rs5919392 SNP in the AR, whereas no association between GGN repeat polymorphism and T concentrations were found. Arm span and 2D:4D finger length ratio were inversely associated, whereas muscle mass and force were not associated with the number of CAG repeats. CONCLUSIONS: Age, physical activity, body composition, sex steroid levels and anthropometrics are determinants of muscle mass and function in young men. Although the number of CAG repeats of the AR are related to sex steroid levels and anthropometrics, we have no evidence that these variations in the AR

  13. Skeletal muscle mass and exercise performance in stable ambulatory patients with heart failure.

    Lang, C C; Chomsky, D B; Rayos, G; Yeoh, T K; Wilson, J R

    1997-01-01

    The purpose of this study was to determine whether skeletal muscle atrophy limits the maximal exercise capacity of stable ambulatory patients with heart failure. Body composition and maximal exercise capacity were measured in 100 stable ambulatory patients with heart failure. Body composition was assessed by using dual-energy X-ray absorption. Peak exercise oxygen consumption (VO2peak) and the anaerobic threshold were measured by using a Naughton treadmill protocol and a Medical Graphics CardioO2 System. VO2peak averaged 13.4 +/- 3.3 ml.min-1.kg-1 or 43 +/- 12% of normal. Lean body mass averaged 52.9 +/- 10.5 kg and leg lean mass 16.5 +/- 3.6 kg. Leg lean mass correlated linearly with VO2peak (r = 0.68, P < 0.01), suggesting that exercise performance is influences by skeletal muscle mass. However, lean body mass was comparable to levels noted in 1,584 normal control subjects, suggesting no decrease in muscle mass. Leg muscle mass was comparable to levels noted in 34 normal control subjects, further supporting this conclusion. These findings suggest that exercise intolerance in stable ambulatory patients with heart failure is not due to skeletal muscle atrophy.

  14. The Effects of Muscle Mass on Homocyst(e)ine Levels in Plasma and Urine.

    Malinow, M René; Lister, Craig L; DE Crée, Carl

    The present study was designed to examine the relationship between homocyst(e)ine (H[e]) levels and muscle mass. Two experimental groups each of 24 Caucasian males, one consisting of higher-muscle mass subjects (HMM) and the other of lower-muscle mass subjects (LMM) participated in this study. Muscle mass was estimated from 24-hour urine collections of creatinine (Crt). Muscle mass was 40.3 ± 15.9 kg in HMM and 37.2 ± 11.4 kg in LMM (P= 0.002). Mean plasma H(e) levels in HMM were 10.29 ± 2.9 nmol/mL, and in LMM were 10.02 ± 2.4 nmol/L (Not significant, [NS]). Urinary H(e) levels (UH[e]) were 9.95 ± 4.3 nmol/mL and 9.22 ± 2.9 nmol/mL for HMM and LMM, respectively (NS). Plasma H(e) levels correlated well with UH(e) (HMM: r= 0.58, P= 0.009; LMM: r= 0.66, P= 0.004). Muscle mass and was not correlated to either plasma H(e) or UH(e). However, in HMM trends were identified for body mass to be correlated with UH(e) (r= 0.39, P= 0.10) and UCrt (r= 0.41, P= 0.08). Surprisingly, in HMM plasma and UCrt were only weakly correlated (r= 0.44, P= 0.06). Our results do not support a causal relationship between the amount of muscle mass and H(e) levels in plasma or urine.

  15. Quantitative analysis of veterinary drugs in bovine muscle and milk by liquid chromatography quadrupole time-of-flight mass spectrometry.

    Saito-Shida, Shizuka; Sakai, Takatoshi; Nemoto, Satoru; Akiyama, Hiroshi

    2017-07-01

    A simple and reliable multiresidue method for quantitative determination of veterinary drugs in bovine muscle and milk using liquid chromatography quadrupole time-of-flight mass spectrometry (LC-QTOF-MS) was developed. Critical MS parameters such as capillary voltage, cone voltage, collision energy, desolvation gas temperature and extraction mass window were carefully optimised to obtain the best possible sensitivity. Analytical samples were prepared using extraction with acetonitrile and hexane in the presence of anhydrous sodium sulphate and acetic acid, followed by ODS cartridge clean-up. The developed method was validated for 82 veterinary drugs in bovine muscle and milk at spike levels of 0.01 and 0.1 mg kg - 1 . With the exception of cefoperazone and phenoxymethylpenicillin, all these compounds exhibited sufficient signal intensity at 0.01 μg ml -1 (equivalent to 0.01 mg kg - 1 ), indicating the high sensitivity of the developed method. For most targets, the determined accuracies were within 70-120%, with repeatability and reproducibility being below 20% at both levels. Except for sulfathiazole in bovine muscle, no interfering peaks at target compound retention times were detected in the blank extract, indicating that the developed method is highly selective. The absence of sulfathiazole in bovine muscle was confirmed by simultaneous acquisition at low and high collision energies to afford exact masses of molecular adduct and fragment ions. Satisfactory linearity was observed for all compounds, with matrix effects being negligible for most targets in bovine muscle and milk at both spike levels. Overall, the results suggest that the developed LC-QTOF-MS method is suitable for routine regulatory-purpose analysis of veterinary drugs in bovine muscle and milk.

  16. Reduced bone mass and muscle strength in male 5α-reductase type 1 inactivated mice.

    Sara H Windahl

    Full Text Available Androgens are important regulators of bone mass but the relative importance of testosterone (T versus dihydrotestosterone (DHT for the activation of the androgen receptor (AR in bone is unknown. 5α-reductase is responsible for the irreversible conversion of T to the more potent AR activator DHT. There are two well established isoenzymes of 5α-reductase (type 1 and type 2, encoded by separate genes (Srd5a1 and Srd5a2. 5α-reductase type 2 is predominantly expressed in male reproductive tissues whereas 5α-reductase type 1 is highly expressed in liver and moderately expressed in several other tissues including bone. The aim of the present study was to investigate the role of 5α-reductase type 1 for bone mass using Srd5a1⁻/⁻ mice. Four-month-old male Srd5a1⁻/⁻ mice had reduced trabecular bone mineral density (-36%, p<0.05 and cortical bone mineral content (-15%, p<0.05 but unchanged serum androgen levels compared with wild type (WT mice. The cortical bone dimensions were reduced in the male Srd5a1⁻/⁻ mice as a result of a reduced cortical periosteal circumference compared with WT mice. T treatment increased the cortical periosteal circumference (p<0.05 in orchidectomized WT mice but not in orchidectomized Srd5a1⁻/⁻ mice. Male Srd5a1⁻/⁻ mice demonstrated a reduced forelimb muscle grip strength compared with WT mice (p<0.05. Female Srd5a1⁻/⁻ mice had slightly increased cortical bone mass associated with elevated circulating levels of androgens. In conclusion, 5α-reductase type 1 inactivated male mice have reduced bone mass and forelimb muscle grip strength and we propose that these effects are due to lack of 5α-reductase type 1 expression in bone and muscle. In contrast, the increased cortical bone mass in female Srd5a1⁻/⁻ mice, is an indirect effect mediated by elevated circulating androgen levels.

  17. The impact of low muscle mass definition on the prevalence of sarcopenia in older Australians.

    Yu, Solomon; Appleton, Sarah; Adams, Robert; Chapman, Ian; Wittert, Gary; Visvanathan, Thavarajah; Visvanathan, Renuka

    2014-01-01

    Sarcopenia is the presence of low muscle mass and low muscle function. The aim of this study was to establish cutoffs for low muscle mass using three published methods and to compare the prevalence of sarcopenia in older Australians. Gender specific cutoffs levels were identified for low muscle mass using three different methods. Low grip strength was determined using established cutoffs of standard deviation (SD) of a young reference population; (b) <7.36 kg/m(2) for men and <5.81 kg/m(2) for women from the lowest 20% percentile of the older group; and (c) <-2.15 for men and <-1.42 for women from the lowest 20% of the residuals of linear regressions of appendicular skeletal mass, adjusted for fat mass and height. Prevalence of sarcopenia in older (65 years and older) people by these three methods for men was 2.5%, 6.2%, and 6.4% and for women 0.3%, 9.3%, and 8.5%, respectively. Sarcopenia is common but consensus on the best method to confirm low muscle mass is required.

  18. Mechanistic Links Underlying the Impact of C-Reactive Protein on Muscle Mass in Elderly

    Britta Wåhlin-Larsson

    2017-11-01

    Full Text Available Background/Aims: Mechanisms underlying the relationship between systemic inflammation and age-related decline in muscle mass are poorly defined. The purpose of this work was to investigate the relationship between the systemic inflammatory marker CRP and muscle mass in elderly and to identify mechanisms by which CRP mediates its effects on skeletal muscle, in-vitro. Methods: Muscle mass and serum CRP level were determined in a cohort of 118 older women (67±1.7 years. Human muscle cells were differentiated into myotubes and were exposed to CRP. The size of myotubes was determined after immunofluorescent staining using troponin. Muscle protein synthesis was assessed using stable isotope tracers and key signalling pathways controlling protein synthesis were determined using western-blotting. Results: We observed an inverse relationship between circulating CRP level and muscle mass (β= -0.646 (95% CI: -0.888, -0.405 p<0.05 and demonstrated a reduction (p < 0.05 in the size of human myotubes exposed to CRP for 72 h. We next showed that this morphological change was accompanied by a CRP-mediated reduction (p < 0.05 in muscle protein fractional synthetic rate of human myotubes exposed to CRP for 24 h. We also identified a CRP-mediated increased phosphorylation (p<0.05 of regulators of cellular energy stress including AMPK and downstream targets, raptor and ACC-β, together with decreased phosphorylation of Akt and rpS6, which are important factors controlling protein synthesis. Conclusion: This work established for the first time mechanistic links by which chronic elevation of CRP can contribute to age-related decline in muscle function.

  19. Locomotion and muscle mass measures in a murine model of collagen-induced arthritis

    Hartog, A.; Hulsman, J.; Garssen, J.

    2009-01-01

    Background: Rheumatoid arthritis (RA) is characterized by chronic poly-arthritis, synovial hyperplasia, erosive synovitis, progressive cartilage and bone destruction accompanied by a loss of body cell mass. This loss of cell mass, known as rheumatoid cachexia, predominates in the skeletal muscle and

  20. High-throughput method for macrolides and lincosamides antibiotics residues analysis in milk and muscle using a simple liquid-liquid extraction technique and liquid chromatography-electrospray-tandem mass spectrometry analysis (LC-MS/MS).

    Jank, Louise; Martins, Magda Targa; Arsand, Juliana Bazzan; Campos Motta, Tanara Magalhães; Hoff, Rodrigo Barcellos; Barreto, Fabiano; Pizzolato, Tânia Mara

    2015-11-01

    A fast and simple method for residue analysis of the antibiotics classes of macrolides (erythromycin, azithromycin, tylosin, tilmicosin and spiramycin) and lincosamides (lincomycin and clindamycin) was developed and validated for cattle, swine and chicken muscle and for bovine milk. Sample preparation consists in a liquid-liquid extraction (LLE) with acetonitrile, followed by liquid chromatography-electrospray-tandem mass spectrometry analysis (LC-ESI-MS/MS), without the need of any additional clean-up steps. Chromatographic separation was achieved using a C18 column and a mobile phase composed by acidified acetonitrile and water. The method was fully validated according the criteria of the Commission Decision 2002/657/EC. Validation parameters such as limit of detection, limit of quantification, linearity, accuracy, repeatability, specificity, reproducibility, decision limit (CCα) and detection capability (CCβ) were evaluated. All calculated values met the established criteria. Reproducibility values, expressed as coefficient of variation, were all lower than 19.1%. Recoveries range from 60% to 107%. Limits of detection were from 5 to 25 µg kg(-1).The present method is able to be applied in routine analysis, with adequate time of analysis, low cost and a simple sample preparation protocol. Copyright © 2015. Published by Elsevier B.V.

  1. Peak muscle mass in young men and sarcopenia in the ageing male

    Nielsen, Morten Frost Munk; Nielsen, T L; Brixen, K

    2015-01-01

    of sarcopenia in men. INTRODUCTION: The ageing population increases the prevalence of sarcopenia. Estimation of normative data on muscle mass in young men during the peak of anabolic hormones is necessary for the diagnosis of sarcopenia in ageing males. The purposes of this study were to provide population......The prevalence of sarcopenia increases with age. The diagnosis of sarcopenia relies in part on normative data on muscle mass, but these data are lacking. This study provides population-based reference data on muscle mass in young men, and these results may be used clinically for the diagnosis......-based reference data on lean body mass (LBM) in young men during the time of peak levels of GH/IGF-1 and testosterone and further to apply the reference data on a population-based sample of men aged 60-74 years to estimate the prevalence of sarcopenia. METHODS: This is a cross-sectional, population-based single...

  2. Growth hormone mitigates loss of periosteal bone formation and muscle mass in disuse osteopenic rats.

    Grubbe, M-C; Thomsen, J S; Nyengaard, J R; Duruox, M; Brüel, A

    2014-12-01

    Growth hormone (GH) is a potent anabolic agent capable of increasing both bone and muscle mass. The aim was to investigate whether GH could counteract disuse-induced loss of bone and muscle mass in a rat model. Paralysis was induced by injecting 4 IU Botox (BTX) into the muscles of the right hind limb. Sixty female Wistar rats, 14 weeks old, were divided into the following groups: baseline, controls, BTX, BTX+GH, and GH. GH was given at a dosage of 5 mg/kg/d for 4 weeks. Compared with controls, BTX resulted in lower periosteal bone formation rate (BFR/BS,-79%, Pbone mineral density (aBMD, -13%, Pbone volume (BV/TV, -26%, Pbone strength (-12%, Pbone strength was found. In addition, GH partly prevented loss of muscle mass (+29% vs. BTX, P<0.001), and tended to prevent loss of muscle CSA (+11%, P=0.064). In conclusion, GH mitigates disuse-induced loss of periosteal BFR/BS at the mid-femur and rectus femoris muscle mass.

  3. Ultrasonography to Measure Swallowing Muscle Mass and Quality in Older Patients With Sarcopenic Dysphagia.

    Ogawa, Nami; Mori, Takashi; Fujishima, Ichiro; Wakabayashi, Hidetaka; Itoda, Masataka; Kunieda, Kenjiro; Shigematsu, Takashi; Nishioka, Shinta; Tohara, Haruka; Yamada, Minoru; Ogawa, Sumito

    2018-06-01

    Sarcopenic dysphagia is characterized by difficulty swallowing due to a loss of whole-body skeletal and swallowing muscle mass and function. However, no study has reported on swallowing muscle mass and quality in patients with sarcopenic dysphagia. To compare the differences in swallowing muscle mass and quality between sarcopenic and nonsarcopenic dysphagia. A cross-sectional study was performed in 55 older patients, who had been recommended to undergo dysphagia assessment and/or rehabilitation. Sarcopenic dysphagia was diagnosed using a diagnostic algorithm for sarcopenic dysphagia. The thickness and area of tongue muscle and geniohyoid muscle (coronal plane and sagittal plane), and the echo-intensity of the tongue and geniohyoid muscles were examined by ultrasound. The study participants included 31 males and 24 females (mean age of 82 ± 7 years), with 14 having possible sarcopenic dysphagia, 22 probable sarcopenic dysphagia, and 19 without sarcopenic dysphagia. The group with sarcopenic dysphagia had a significantly lower cross-sectional area and area of brightness of the tongue muscle than that observed in the group without sarcopenic dysphagia. The most specific factor for identifying the presence of sarcopenic dysphagia was tongue muscle area (sensitivity, 0.389; specificity, 0.947; cut-off value, 1536.0), while the factor with the highest sensitivity was geniohyoid muscle area brightness in sagittal sections (sensitivity, 0.806; specificity, 0.632; cut-off value, 20.1). Multivariate logistic regression analysis showed that the area of the tongue muscle and its area of brightness were independent risk factors for sarcopenic dysphagia. However, geniohyoid sagittal muscle area and area of brightness showed no significant independent association with sarcopenic dysphagia. Tongue muscle mass in patients with sarcopenic dysphagia was smaller than that in patients without the condition. Sarcopenic dysphagia was also associated with increased intensity of the

  4. MALDI imaging mass spectrometry: discrimination of pathophysiological regions in traumatized skeletal muscle by characteristic peptide signatures.

    Klein, Oliver; Strohschein, Kristin; Nebrich, Grit; Oetjen, Janina; Trede, Dennis; Thiele, Herbert; Alexandrov, Theodore; Giavalisco, Patrick; Duda, Georg N; von Roth, Philipp; Geissler, Sven; Klose, Joachim; Winkler, Tobias

    2014-10-01

    Due to formation of fibrosis and the loss of contractile muscle tissue, severe muscle injuries often result in insufficient healing marked by a significant reduction of muscle force and motor activity. Our previous studies demonstrated that the local transplantation of mesenchymal stromal cells into an injured skeletal muscle of the rat improves the functional outcome of the healing process. Since, due to the lack of sufficient markers, the accurate discrimination of pathophysiological regions in injured skeletal muscle is inadequate, underlying mechanisms of the beneficial effects of mesenchymal stromal cell transplantation on primary trauma and trauma adjacent muscle area remain elusive. For discrimination of these pathophysiological regions, formalin-fixed injured skeletal muscle tissue was analyzed by MALDI imaging MS. By using two computational evaluation strategies, a supervised approach (ClinProTools) and unsupervised segmentation (SCiLS Lab), characteristic m/z species could be assigned to primary trauma and trauma adjacent muscle regions. Using "bottom-up" MS for protein identification and validation of results by immunohistochemistry, we could identify two proteins, skeletal muscle alpha actin and carbonic anhydrase III, which discriminate between the secondary damage on adjacent tissue and the primary traumatized muscle area. Our results underscore the high potential of MALDI imaging MS to describe the spatial characteristics of pathophysiological changes in muscle. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  5. Effect of anabolic steroids on skeletal muscle mass during hindlimb suspension

    Tsika, R. W.; Herrick, R. E.; Baldwin, K. M.

    1987-01-01

    The effect of treatment with an anabolic steroid (nandrolone decanoate) on the muscle mass of plantaris and soleus of a rats in hindlimb suspension, and on the isomyosin expression in these muscles, was investigated in young female rats divided into four groups: normal control (NC), normal steroid (NS), normal suspension (N-sus), and suspension steroid (sus-S). Steroid treatment of suspended animals (sus-S vs N-sus) was found to partially spare body weight and muscle weight, as well as myofibril content of plantaris (but not soleus), but did not modify the isomyosin pattern induced by suspension. In normal rats (NS vs NC), steroid treatment did enhance body weight and plantaris muscle weight; the treatment did not alter isomyosin expression in either muscle type.

  6. Low muscle mass--tall and obese children a special genre of obesity.

    Ralt, Dina

    2007-01-01

    The prevalence of over-weight and obesity has increased markedly in the last two decades and vast international resources have been directed toward researching these issues. Obesity would appear to be a problem that is easy to resolve: just eat less and move more. However, this very common condition has turned out to be extremely troublesome, and in some cases even insolvable. A perspective is presented here suggesting that some of the insoluble cases of obesity are the result of an inborn condition of a very low muscle mass. The interplay between less muscle and more fat tissue is discussed from physiological and environmental perspectives with an emphasis on the early years of childhood. It is proposed that these interactions lead to bodily economic decisions sliding between thrift or prodigal strategies. The thrift strategy results not only in obesity and less physical activity but also in other maladies which the body is unable to manage. What leads to obesity (less muscle, more fat) in the medial population will result in morbid obesity when the children are short of muscle tissue from the start. Attempts to lessen the consequences of low muscle mass, which might be very difficult at adulthood, can be more fruitful if initiated at childhood. Early recognition of the ailment is thus crucial. Based on studies demonstrating a 'rivalry' between muscle build-up and height growth at childhood, it is postulated that among the both taller and more obese children the percentage of children with lower muscle mass will be significant. A survey of the height and BMI (Body Mass Index) of Israeli fifth graders supports this postulation. A special, body/muscle-building gymnastics program for children is suggested as a potential early intervention to partially prevent this type of almost irreversible ill progress of obesity.

  7. Delayed Recovery of Skeletal Muscle Mass following Hindlimb Immobilization in mTOR Heterozygous Mice

    Lang, Susan M.; Kazi, Abid A.; Hong-Brown, Ly; Lang, Charles H.

    2012-01-01

    The present study addressed the hypothesis that reducing mTOR, as seen in mTOR heterozygous (+/-) mice, would exaggerate the changes in protein synthesis and degradation observed during hindlimb immobilization as well as impair normal muscle regrowth during the recovery period. Atrophy was produced by unilateral hindlimb immobilization and data compared to the contralateral gastrocnemius. In wild-type (WT) mice, the gradual loss of muscle mass plateaued by day 7. This response was associated ...

  8. Impaired physical function, loss of muscle mass and assessment of biomechanical properties in critical ill patients

    Poulsen, Jesper Brøndum

    2012-01-01

    Intensive care unit (ICU) admission is associated with muscle weakness and ICU survivors report sustained limitation of physical capacity for years after discharge. Limited information is available on the underlying biomechanical properties responsible for this muscle function impairment. A plaus......Intensive care unit (ICU) admission is associated with muscle weakness and ICU survivors report sustained limitation of physical capacity for years after discharge. Limited information is available on the underlying biomechanical properties responsible for this muscle function impairment....... A plausible contributor to the accentuated catabolic drive in ICU patients is a synergistic response to inflammation and inactivity leading to loss of muscle mass. As these entities are predominantly present in the early phase of ICU stay, interventions employed during this time frame may exhibit the greatest...... potential to counteract loss of muscle mass. Despite the obvious clinical significance of muscle atrophy for the functional impairment observed in ICU survivors, no preventive therapies have been identified as yet. The overall aim of the present dissertation is to characterize aspects of physical function...

  9. The loss of skeletal muscle strength, mass, and quality in older adults : the health, aging and body composition study

    Goodpaster, Bret H; Park, Seok Won; Harris, Tamara B; Kritchevsky, Steven B; Nevitt, Michael; Schwartz, Ann V; Simonsick, Eleanor M; Tylavsky, Frances A; Visser, Marjolein; Newman, Anne B

    2006-01-01

    BACKGROUND: The loss of muscle mass is considered to be a major determinant of strength loss in aging. However, large-scale longitudinal studies examining the association between the loss of mass and strength in older adults are lacking. METHODS: Three-year changes in muscle mass and strength were

  10. Creatinine excretion rate, a marker of muscle mass, is related to clinical outcome in patients with chronic systolic heart failure

    ter Maaten, Jozine M.; Damman, Kevin; Hillege, Hans L.; Bakker, Stephan J.; Anker, Stefan D.; Navis, Gerjan; Voors, Adriaan A.

    2014-01-01

    Aims In chronic heart failure (CHF), low body mass as a reflection of low muscle mass has been associated with poor outcome. Urinary creatinine excretion rate (CER) is an established marker of muscle mass, but has not been investigated in CHF. This study aims to evaluate urinary CER as a marker of

  11. Muscle mass as a target to reduce fatigue in patients with advanced cancer.

    Neefjes, Elisabeth C W; van den Hurk, Renske M; Blauwhoff-Buskermolen, Susanne; van der Vorst, Maurice J D L; Becker-Commissaris, Annemarie; de van der Schueren, Marian A E; Buffart, Laurien M; Verheul, Henk M W

    2017-08-01

    Cancer-related fatigue (CRF) reduces quality of life and the activity level of patients with cancer. Cancer related fatigue can be reduced by exercise interventions that may concurrently increase muscle mass. We hypothesized that low muscle mass is directly related to higher CRF. A total of 233 patients with advanced cancer starting palliative chemotherapy for lung, colorectal, breast, or prostate cancer were studied. The skeletal muscle index (SMI) was calculated as the patient's muscle mass on level L3 or T4 of a computed tomography scan, adjusted for height. Fatigue was assessed with the Functional Assessment of Chronic Illness Therapy-fatigue questionnaire (cut-off for fatigue fatigue score was 36 (interquartile range 26-44). A higher SMI on level L3 was significantly associated with less CRF for men (B 0.447, P 0.004) but not for women (B - 0.401, P 0.090). No association between SMI on level T4 and the Functional Assessment of Chronic Illness Therapy-fatigue score was found (n = 82). The association between SMI and CRF may lead to the suggestion that male patients may be able to reduce fatigue by exercise interventions aiming at an increased muscle mass. In women with advanced cancer, CRF is more influenced by other causes, because it is not significantly related to muscle mass. To further reduce CRF in both men and women with cancer, multifactorial assessments need to be performed in order to develop effective treatment strategies. © 2017 The Authors. Journal of Cachexia, Sarcopenia and Muscle published by John Wiley & Sons Ltd on behalf of the Society on Sarcopenia, Cachexia and Wasting Disorders.

  12. Correlates of increased lean muscle mass in women with polycystic ovary syndrome.

    Carmina, E; Guastella, E; Longo, R A; Rini, G B; Lobo, R A

    2009-10-01

    Muscle mass plays an important role in determining cardiovascular and metabolic risks in polycystic ovary syndrome (PCOS). In addition, whether lean mass influences carotid intima-media thickness (IMT) in PCOS has not been assessed. Prospective investigation. Ninety-five women with PCOS were age- and weight-matched to 90 ovulatory controls. All women had dual X-ray absorptiometry for lean, fat and bone mass, and bone mass density (BMD). Serum testosterone, sex hormone-binding globulin, insulin, and glucose and carotid IMT were determined. Free androgen index (FAI) and insulin resistance (by QUICKI) were calculated. In PCOS, waist circumference and insulin were higher and QUICKI lower than in controls (Plean mass were higher in PCOS compared to controls (PPCOS (PPCOS patients had abnormal (> or = 0.9 mm) values. Lean mass correlated with fat parameters, insulin, QUICKI, and FAI, but not with total testosterone; and after adjustments for insulin and QUICKI, lean mass still correlated with fat mass (PLean mass correlated with IMT (Plean mass independently of insulin. Bone mass correlated with lean and fat mass, but not with insulin or androgen. PCOS patients with 'pathological' IMT values had higher % trunk fat, lean mass, and insulin, lower QUICKI, and higher testosterone and FAI compared with those with normal IMT. Lean mass is increased in PCOS, while bone mass is similar to that of matched controls. The major correlates of lean mass are fat mass and insulin but not androgen. Lean mass also correlated with IMT, and although influenced by insulin, small changes in IMT may partially reflect changes in muscle mass, while clearly abnormal values relate to more severe abnormalities of PCOS.

  13. FMAj: a tool for high content analysis of muscle dynamics in Drosophila metamorphosis

    2014-01-01

    Background During metamorphosis in Drosophila melanogaster, larval muscles undergo two different developmental fates; one population is removed by cell death, while the other persistent subset undergoes morphological remodeling and survives to adulthood. Thanks to the ability to perform live imaging of muscle development in transparent pupae and the power of genetics, metamorphosis in Drosophila can be used as a model to study the regulation of skeletal muscle mass. However, time-lapse microscopy generates sizeable image data that require new tools for high throughput image analysis. Results We performed targeted gene perturbation in muscles and acquired 3D time-series images of muscles in metamorphosis using laser scanning confocal microscopy. To quantify the phenotypic effects of gene perturbations, we designed the Fly Muscle Analysis tool (FMAj) which is based on the ImageJ and MySQL frameworks for image processing and data storage, respectively. The image analysis pipeline of FMAj contains three modules. The first module assists in adding annotations to time-lapse datasets, such as genotypes, experimental parameters and temporal reference points, which are used to compare different datasets. The second module performs segmentation and feature extraction of muscle cells and nuclei. Users can provide annotations to the detected objects, such as muscle identities and anatomical information. The third module performs comparative quantitative analysis of muscle phenotypes. We applied our tool to the phenotypic characterization of two atrophy related genes that were silenced by RNA interference. Reduction of Drosophila Tor (Target of Rapamycin) expression resulted in enhanced atrophy compared to control, while inhibition of the autophagy factor Atg9 caused suppression of atrophy and enlarged muscle fibers of abnormal morphology. FMAj enabled us to monitor the progression of atrophic and hypertrophic phenotypes of individual muscles throughout metamorphosis

  14. FMAj: a tool for high content analysis of muscle dynamics in Drosophila metamorphosis.

    Kuleesha, Yadav; Puah, Wee Choo; Lin, Feng; Wasser, Martin

    2014-01-01

    During metamorphosis in Drosophila melanogaster, larval muscles undergo two different developmental fates; one population is removed by cell death, while the other persistent subset undergoes morphological remodeling and survives to adulthood. Thanks to the ability to perform live imaging of muscle development in transparent pupae and the power of genetics, metamorphosis in Drosophila can be used as a model to study the regulation of skeletal muscle mass. However, time-lapse microscopy generates sizeable image data that require new tools for high throughput image analysis. We performed targeted gene perturbation in muscles and acquired 3D time-series images of muscles in metamorphosis using laser scanning confocal microscopy. To quantify the phenotypic effects of gene perturbations, we designed the Fly Muscle Analysis tool (FMAj) which is based on the ImageJ and MySQL frameworks for image processing and data storage, respectively. The image analysis pipeline of FMAj contains three modules. The first module assists in adding annotations to time-lapse datasets, such as genotypes, experimental parameters and temporal reference points, which are used to compare different datasets. The second module performs segmentation and feature extraction of muscle cells and nuclei. Users can provide annotations to the detected objects, such as muscle identities and anatomical information. The third module performs comparative quantitative analysis of muscle phenotypes. We applied our tool to the phenotypic characterization of two atrophy related genes that were silenced by RNA interference. Reduction of Drosophila Tor (Target of Rapamycin) expression resulted in enhanced atrophy compared to control, while inhibition of the autophagy factor Atg9 caused suppression of atrophy and enlarged muscle fibers of abnormal morphology. FMAj enabled us to monitor the progression of atrophic and hypertrophic phenotypes of individual muscles throughout metamorphosis. We designed a new tool to

  15. Within-Winter Flexibility in Muscle Masses, Myostatin, and Cellular Aerobic Metabolic Intensity in Passerine Birds.

    Swanson, David L; King, Marisa O; Culver, William; Zhang, Yufeng

    Metabolic rates of passerine birds are flexible traits that vary both seasonally and among and within winters. Seasonal variation in summit metabolic rates (M sum = maximum thermoregulatory metabolism) in birds is consistently correlated with changes in pectoralis muscle and heart masses and sometimes with variation in cellular aerobic metabolic intensity, so these traits might also be associated with shorter-term, within-winter variation in metabolic rates. To determine whether these mechanisms are associated with within-winter variation in M sum , we examined the effects of short-term (ST; 0-7 d), medium-term (MT; 14-30 d), and long-term (LT; 30-yr means) temperature variables on pectoralis muscle and heart masses, pectoralis expression of the muscle-growth inhibitor myostatin and its metalloproteinase activators TLL-1 and TLL-2, and pectoralis and heart citrate synthase (CS; an indicator of cellular aerobic metabolic intensity) activities for two temperate-zone resident passerines, house sparrows (Passer domesticus) and dark-eyed juncos (Junco hyemalis). For both species, pectoralis mass residuals were positively correlated with ST temperature variables, suggesting that cold temperatures resulted in increased turnover of pectoralis muscle, but heart mass showed little within-winter variation for either species. Pectoralis mRNA and protein expression of myostatin and the TLLs were only weakly correlated with ST and MT temperature variables, which is largely consistent with trends in muscle masses for both species. Pectoralis and heart CS activities showed weak and variable trends with ST temperature variables in both species, suggesting only minor effects of temperature variation on cellular aerobic metabolic intensity. Thus, neither muscle or heart masses, regulation by the myostatin system, nor cellular aerobic metabolic intensity varied consistently with winter temperature, suggesting that other factors regulate within-winter metabolic variation in these birds.

  16. Artistic versus rhythmic gymnastics: effects on bone and muscle mass in young girls.

    Vicente-Rodriguez, G; Dorado, C; Ara, I; Perez-Gomez, J; Olmedillas, H; Delgado-Guerra, S; Calbet, J A L

    2007-05-01

    We compared 35 prepubertal girls, 9 artistic gymnasts and 13 rhythmic gymnasts with 13 nonphysically active controls to study the effect of gymnastics on bone and muscle mass. Lean mass, bone mineral content and areal density were measured by dual energy X-ray absorptiometry, and physical fitness was also assessed. The artistic gymnasts showed a delay in pubertal development compared to the other groups (partistic gymnasts had a 16 and 17 % higher aerobic power and anaerobic capacity, while the rhythmic group had a 14 % higher anaerobic capacity than the controls, respectively (all partistic gymnasts had higher lean mass (partistic and the rhythmic gymnasts (partistic group compared to the other groups. Lean mass strongly correlated with bone mineral content (r=0.84, partistic gymnastic participation is associated with delayed pubertal development, enhanced physical fitness, muscle mass, and bone density in prepubertal girls, eliciting a higher osteogenic stimulus than rhythmic gymnastic.

  17. High-intensity stretch-shortening contraction training modifies responsivity of skeletal muscle in old male rats.

    Rader, Erik P; Naimo, Marshall A; Ensey, James; Baker, Brent A

    2018-04-01

    Utilization of high-intensity resistance training to counter age-related sarcopenia is currently debated because of the potential for maladaptation when training design is inappropriate. Training design is problematic because the influence of various loading variables (e.g. contraction mode, repetition number, and training frequency) is still not well characterized at old age. To address this in a precisely controlled manner, we developed a rodent model of high-intensity training consisting of maximally-activated stretch-shortening contractions (SSCs), contractions typical during resistance training. With this model, we determined that at old age, high-repetition SSC training (80 SSCs: 8 sets of 10 repetitions) performed frequently (i.e. 3 days per week) for 4.5 weeks induced strength deficits with no muscle mass gain while decreasing frequency to 2 days per week promoted increases in muscle mass and muscle quality (i.e. performance normalized to muscle mass). This finding confirmed the popular notion that decreasing training frequency has a robust effect with age. Meanwhile, the influence of other loading variables remains contentious. The aim of the present study was to assess muscle adaptation following modulation of contraction mode and repetition number during high-intensity SSC training. Muscles of young (3 month old) and old (30 month old) male rats were exposed to 4.5 weeks of low-repetition static training of 4 (i.e. 4 sets of one repetition) isometric (ISO) contractions 3 days per week or a more moderate-repetition dynamic training of 40 SSCs (i.e. 4 sets of 10 repetitions) 3 days per week. For young rats, performance and muscle mass increased regardless of training protocol. For old rats, no muscle mass adaptation was observed for 4 ISO training while 40 SSC training induced muscle mass gain without improvement in muscle quality, an outcome distinct from modulating training frequency. Muscle mass gain for old rats was accompanied by

  18. Morphometry, ultrastructure, myosin isoforms, and metabolic capacities of the "mini muscles" favoured by selection for high activity in house mice.

    Guderley, Helga; Houle-Leroy, Philippe; Diffee, Gary M; Camp, Dana M; Garland, Theodore

    2006-07-01

    Prolonged selective breeding of mice (Mus musculus) for high levels of voluntary wheel running has favoured an unusual phenotype ("mini muscles"), apparently caused by a single Mendelian recessive allele, in which most hind-limb muscles are markedly reduced in mass, but have increased mass-specific activities of mitochondrial enzymes. We examined whether these changes reflect changes in fibre size, number or ultrastructure in normal and "mini-muscle" mice within the two (of four) selectively bred lines (lab designations L3 and L6) that exhibit the phenotype at generations 26 and 27. In both lines, the gastrocnemius and plantaris muscles are smaller in mass (by >50% and 20%, respectively) in affected individuals. The mass-specific activities of mitochondrial enzymes in the gastrocnemius and plantaris muscles were increased in the mini phenotype in both lines, with stronger effects in the gastrocnemius muscle. In the gastrocnemius, the % myosin heavy chain (MHC) IIb was reduced by 50% in L3 and by 30% in L6, whereas the % MHC IIa and I were higher, particularly in L3. Fibre number in the plantaris muscle did not significantly differ between mini and normal muscles, although muscle mass was a significant positive correlate of fibre number. Small fibres were more abundant in mini than normal muscles in L3. Mitochondrial volume density was significantly higher in mini than normal muscle fibres in L3, but not in L6. Microscopy revealed a surprising attribute of the mini muscles: an abundance of small, minimally differentiated, myofibril-containing cells positioned in a disorderly fashion, particularly in the surface layer. We hypothesise that these unusual cells may be satellite cells or type IIb fibres that did not complete their differentiation. Together, these observations suggest that mice with the mini phenotype have reduced numbers of type IIb fibres in many of their hind-limb muscles, leading to a decrease in mass and an increase in mass-specific aerobic capacity

  19. Rat muscle blood flows during high-speed locomotion

    Armstrong, R.B.; Laughlin, M.H.

    1985-01-01

    We previously studied blood flow distribution within and among rat muscles as a function of speed from walking (15 m/min) through galloping (75 m/min) on a motor-driven treadmill. The results showed that muscle blood flows continued to increase as a function of speed through 75 m/min. The purpose of the present study was to have rats run up to maximal treadmill speeds to determine if blood flows in the muscles reach a plateau as a function of running speed over the animals normal range of locomotory speeds. Muscle blood flows were measured with radiolabeled microspheres at 1 min of running at 75, 90, and 105 m/min in male Sprague-Dawley rats. The data indicate that even at these relatively high treadmill speeds there was still no clear evidence of a plateau in blood flow in most of the hindlimb muscles. Flows in most muscles continued to increase as a function of speed. These observed patterns of blood flow vs. running speed may have resulted from the rigorous selection of rats that were capable of performing the high-intensity exercise and thus only be representative of a highly specific population of animals. On the other hand, the data could be interpreted to indicate that the cardiovascular potential during exercise is considerably higher in laboratory rats than has normally been assumed and that inadequate blood flow delivery to the muscles does not serve as a major limitation to their locomotory performance

  20. MUSCLE: multiple sequence alignment with high accuracy and high throughput.

    Edgar, Robert C

    2004-01-01

    We describe MUSCLE, a new computer program for creating multiple alignments of protein sequences. Elements of the algorithm include fast distance estimation using kmer counting, progressive alignment using a new profile function we call the log-expectation score, and refinement using tree-dependent restricted partitioning. The speed and accuracy of MUSCLE are compared with T-Coffee, MAFFT and CLUSTALW on four test sets of reference alignments: BAliBASE, SABmark, SMART and a new benchmark, PREFAB. MUSCLE achieves the highest, or joint highest, rank in accuracy on each of these sets. Without refinement, MUSCLE achieves average accuracy statistically indistinguishable from T-Coffee and MAFFT, and is the fastest of the tested methods for large numbers of sequences, aligning 5000 sequences of average length 350 in 7 min on a current desktop computer. The MUSCLE program, source code and PREFAB test data are freely available at http://www.drive5. com/muscle.

  1. Psoas Muscle Cross-sectional Area as a Measure of Whole-body Lean Muscle Mass in Maintenance Hemodialysis Patients.

    Morrell, Glen R; Ikizler, Talat A; Chen, Xiaorui; Heilbrun, Marta E; Wei, Guo; Boucher, Robert; Beddhu, Srinivasan

    2016-07-01

    We investigate whether psoas or paraspinous muscle area measured on a single L4-L5 image is a useful measure of whole lean body mass (LBM) compared to dedicated midthigh magnetic resonance imaging (MRI). Observational study. Outpatient dialysis units and a research clinic. One hundred five adult participants on maintenance hemodialysis. No control group was used. Psoas muscle area, paraspinous muscle area, and midthigh muscle area (MTMA) were measured by magnetic resonance imaging. LBM was measured by dual-energy absorptiometry scan. In separate multivariable linear regression models, psoas, paraspinous, and MTMA were associated with increase in LBM. In separate multivariate logistic regression models, C statistics for diagnosis of sarcopenia (defined as <25th percentile of LBM) were 0.69 for paraspinous muscle area, 0.81 for psoas muscle area, and 0.89 for MTMA. With sarcopenia defined as <10th percentile of LBM, the corresponding C statistics were 0.71, 0.92, and 0.94. We conclude that psoas muscle area provides a good measure of whole-body muscle mass, better than paraspinous muscle area but slightly inferior to midthigh measurement. Hence, in body composition studies a single axial MR image at the L4-L5 level can be used to provide information on both fat and muscle and may eliminate the need for time-consuming measurement of muscle area in the thigh. Copyright © 2016 National Kidney Foundation, Inc. Published by Elsevier Inc. All rights reserved.

  2. Strain in shock-loaded skeletal muscle and the time scale of muscular wobbling mass dynamics.

    Christensen, Kasper B; Günther, Michael; Schmitt, Syn; Siebert, Tobias

    2017-10-16

    In terrestrial locomotion, muscles undergo damped oscillations in response to limb impacts with the ground. Muscles are also actuators that generate mechanical power to allow locomotion. The corresponding elementary contractile process is the work stroke of an actin-myosin cross-bridge, which may be forcibly detached by superposed oscillations. By experimentally emulating rat leg impacts, we found that full activity and non-fatigue must meet to possibly prevent forcible cross-bridge detachment. Because submaximal muscle force represents the ordinary locomotor condition, our results show that forcible, eccentric cross-bridge detachment is a common, physiological process even during isometric muscle contractions. We also calculated the stiffnesses of the whole muscle-tendon complex and the fibre material separately, as well as Young's modulus of the latter: 1.8 MPa and 0.75 MPa for fresh, fully active and passive fibres, respectively. Our inferred Young's modulus of the tendon-aponeurosis complex suggests that stiffness in series to the fibre material is determined by the elastic properties of the aponeurosis region, rather than the tendon material. Knowing these stiffnesses and the muscle mass, the complex' eigenfrequency for responses to impacts can be quantified, as well as the size-dependency of this time scale of muscular wobbling mass dynamics.

  3. Anti-myostatin antibody increases muscle mass and strength and improves insulin sensitivity in old mice.

    Camporez, João-Paulo G; Petersen, Max C; Abudukadier, Abulizi; Moreira, Gabriela V; Jurczak, Michael J; Friedman, Glenn; Haqq, Christopher M; Petersen, Kitt Falk; Shulman, Gerald I

    2016-02-23

    Sarcopenia, or skeletal muscle atrophy, is a debilitating comorbidity of many physiological and pathophysiological processes, including normal aging. There are no approved therapies for sarcopenia, but the antihypertrophic myokine myostatin is a potential therapeutic target. Here, we show that treatment of young and old mice with an anti-myostatin antibody (ATA 842) for 4 wk increased muscle mass and muscle strength in both groups. Furthermore, ATA 842 treatment also increased insulin-stimulated whole body glucose metabolism in old mice, which could be attributed to increased insulin-stimulated skeletal muscle glucose uptake as measured by a hyperinsulinemic-euglycemic clamp. Taken together, these studies provide support for pharmacological inhibition of myostatin as a potential therapeutic approach for age-related sarcopenia and metabolic disease.

  4. Leg blood flow is impaired during small muscle mass exercise in patients with COPD

    Iepsen, Ulrik Winning; Munch, Gregers Druedal Wibe; Rugbjerg, Mette

    2017-01-01

    to both endothelium-independent (SNP) and endothelium-dependent (ACh) stimulation. The results suggests that leg muscle blood flow is impaired during small muscle mass exercise in patients with COPD possibly due to impaired formation of prostacyclin and increased levels of endothelin-1.......Skeletal muscle blood flow is regulated to match the oxygen demand and dysregulation could contribute to exercise intolerance in patients with COPD. We measured leg hemodynamics and metabolites from vasoactive compounds in muscle interstitial fluid and plasma at rest, during one-legged knee...... the formation of interstitial prostacyclin (vasodilator) was only increased in the controls. There was no difference between groups in the nitrite/nitrate levels (vasodilator) in plasma or interstitial fluid during exercise. Moreover, patients and controls showed similar vasodilatory capacity in response...

  5. Impact of low skeletal muscle mass and density on short and long-term outcome after resection of stage I-III colorectal cancer.

    van Vugt, Jeroen L A; Coebergh van den Braak, Robert R J; Lalmahomed, Zarina S; Vrijland, Wietske W; Dekker, Jan W T; Zimmerman, David D E; Vles, Wouter J; Coene, Peter-Paul L O; IJzermans, Jan N M

    2018-06-06

    Preoperative low skeletal muscle mass and density are associated with increased postoperative morbidity in patients undergoing curative colorectal cancer (CRC) surgery. However, the long-term effects of low skeletal muscle mass and density remain uncertain. Patients with stage I-III CRC undergoing surgery, enrolled in a prospective observational cohort study, were included. Skeletal muscle mass and density were measured on CT. Patients with high and low skeletal muscle mass and density were compared regarding postoperative complications, disease-free survival (DFS), overall survival (OS), and cancer-specific survival (CSS). In total, 816 patients (53.9% males, median age 70) were included; 50.4% had low skeletal muscle mass and 64.1% low density. The severe postoperative complication rate was significantly higher in patients with low versus high skeletal muscle and density (20.9% versus 13.6%, p = 0.006; 20.0% versus 11.8%, p = 0.003). Low skeletal muscle mass (OR 1.91, p = 0.018) and density (OR 1.87, p = 0.045) were independently associated with severe postoperative complications. Ninety-day mortality was higher in patients with low skeletal muscle mass and density compared with patients with high skeletal muscle mass and density (3.6% versus 1.7%, p = 0.091; 3.4% versus 1.0%, p = 0.038). No differences in DFS were observed. After adjustment for covariates such as age and comorbidity, univariate differences in OS and CSS diminished. Low skeletal muscle mass and density are associated with short-term, but not long-term, outcome in patients undergoing CRC surgery. These findings recommend putting more emphasis on preoperative management of patients at risk for surgical complications, but do not support benefit for long-term outcome. Copyright © 2018 Elsevier Ltd, BASO ~ The Association for Cancer Surgery, and the European Society of Surgical Oncology. All rights reserved.

  6. The Influence of Body Mass Index, Sex, & Muscle Activation on Pressure Distribution During Lateral Falls on the Hip.

    Pretty, Steven P; Martel, Daniel R; Laing, Andrew C

    2017-12-01

    Hip fracture incidence rates are influenced by body mass index (BMI) and sex, likely through mechanistic pathways that influence dynamics of the pelvis-femur system during fall-related impacts. The goal of this study was to extend our understanding of these impact dynamics by investigating the effects of BMI, sex, and local muscle activation on pressure distribution over the hip region during lateral impacts. Twenty participants underwent "pelvis-release experiments" (which simulate a lateral fall onto the hip), including muscle-'relaxed' and 'contracted' trials. Males and low-BMI individuals exhibited 44 and 55% greater peak pressure, as well as 66 and 56% lower peripheral hip force, compared to females and high-BMI individuals, respectively. Local muscle activation increased peak force by 10%, contact area by 17%, and peripheral hip force by 11% compared to relaxed trials. In summary, males and low-BMI individuals exhibited more concentrated loading over the greater trochanter. Muscle activation increased peak force, but this force was distributed over a larger area, preventing increased localized loading over the greater trochanter. These findings suggest potential value in incorporating sex, gender, and muscle activation-specific force distributions as inputs into computational tissue-level models, and have implications for the design of personalized protective devices including wearable hip protectors.

  7. Tissue Selective Androgen Receptor Modulators (SARMs) Increase Pelvic Floor Muscle Mass in Ovariectomized Mice.

    Ponnusamy, Suriyan; Sullivan, Ryan D; Thiyagarajan, Thirumagal; Tillmann, Heather; Getzenberg, Robert H; Narayanan, Ramesh

    2017-03-01

    Stress urinary incontinence (SUI), a prevalent condition, is represented by an involuntary leakage of urine that results, at least in part, from weakened or damaged pelvic floor muscles and is triggered by physical stress. Current treatment options are limited with no oral therapies available. The pelvic floor is rich in androgen receptor and molecules with anabolic activity including selective androgen receptor modulators (SARMs) may serve as therapeutic options for individuals with SUI. In this study, two SARMs (GTx-024 and GTx-027) were evaluated in a post-menopausal animal model in order to determine their effect on pelvic floor muscles. Female C57BL/6 mice were ovariectomized and their pelvic muscles allowed to regress. The animals were then treated with vehicle or doses of GTx-024 or GTx-027. Animal total body weight, lean body mass, and pelvic floor muscle weights were measured along with the expression of genes associated with muscle catabolism. Treatment with the SARMs resulted in a restoration of the pelvic muscles to the sham-operated weight. Coordinately, the induction of genes associated with muscle catabolism was inhibited. Although a trend was observed towards an increase in total lean body mass in the SARM-treated groups, no significant differences were detected. Treatment of an ovariectomized mouse model with SARMs resulted in an increase in pelvic floor muscles, which may translate to an improvement of symptoms associated with SUI and serves as the basis for evaluating their clinical use. J. Cell. Biochem. 118: 640-646, 2017. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

  8. Insulin Resistance Negatively Influences the Muscle-Dependent IGF-1-Bone Mass Relationship in Premenarcheal Girls.

    Kindler, J M; Pollock, N K; Laing, E M; Jenkins, N T; Oshri, A; Isales, C; Hamrick, M; Lewis, R D

    2016-01-01

    IGF-1 promotes bone growth directly and indirectly through its effects on skeletal muscle. Insulin and IGF-1 share a common cellular signaling process; thus, insulin resistance may influence the IGF-1-muscle-bone relationship. We sought to determine the effect of insulin resistance on the muscle-dependent relationship between IGF-1 and bone mass in premenarcheal girls. This was a cross-sectional study conducted at a university research center involving 147 girls ages 9 to 11 years. Glucose, insulin, and IGF-1 were measured from fasting blood samples. Homeostasis model assessment of insulin resistance (HOMA-IR) was calculated from glucose and insulin. Fat-free soft tissue (FFST) mass and bone mineral content (BMC) were measured by dual-energy x-ray absorptiometry. Our primary outcome was BMC/height. In our path model, IGF-1 predicted FFST mass (b = 0.018; P = .001), which in turn predicted BMC/height (b = 0.960; P IGF-1 predicted BMC/height (b = 0.001; P = .002), but not after accounting for the mediator of this relationship, FFST mass. The HOMA-IR by IGF-1 interaction negatively predicted FFST mass (b = -0.044; P = .034). HOMA-IR had a significant and negative effect on the muscle-dependent relationship between IGF-1 and BMC/height (b = -0.151; P = .047). Lean body mass is an important intermediary factor in the IGF-1-bone relationship. For this reason, bone development may be compromised indirectly via suboptimal IGF-1-dependent muscle development in insulin-resistant children.

  9. Loss of mass and performance in skeletal muscle tissue: a continuum model

    Giantesio Giulia

    2018-02-01

    Full Text Available We present a continuum hyperelastic model which describes the mechanical response of a skeletal muscle tissue when its strength and mass are reduced by aging. Such a reduction is typical of a geriatric syndrome called sarcopenia. The passive behavior of the material is described by a hyperelastic, polyconvex, transversely isotropic strain energy function, and the activation of the muscle is modeled by the so called active strain approach. The loss of ability of activating of an elder muscle is then obtained by lowering of some percentage the active part of the stress, while the loss of mass is modeled through a multiplicative decomposition of the deformation gradient. The obtained stress-strain relations are graphically represented and discussed in order to study some of the effects of sarcopenia.

  10. Premature loss of muscle mass and function in type 2 diabetes.

    Guerrero, N; Bunout, D; Hirsch, S; Barrera, G; Leiva, L; Henríquez, S; De la Maza, M P

    2016-07-01

    Muscle mass and function are among the most relevant factors that contribute to an optimal quality of life, and are strong predictors of mortality in the elderly. Loss of lean tissues and deterioration of muscle function have been described as one of the many complications of type 2 diabetes mellitus (DM2), but most studies do not isolate age as an intervening factor. To study whether adult DM2 patients up to 60years of age have decreased muscle mass and function compared with healthy non-diabetic (ND) subjects of similar age. Appendicular fat-free mass (ApFFM) by dual X-ray absorptiometry (DEXA), handgrip strength (HS), quadriceps strength (QS), 12 min walking capacity (12MW) and the Timed Up and Go test (TUG) were measured in 100 DM2 patients and 39 ND controls. Muscle quality, or the ratio between lean mass and muscle strength of upper and lower limbs, and the functional limitations associated with pain and stiffness assessed according to the Western Ontario and McMaster Universities Arthrosis Index (WOMAC) were also recorded. Specific tests were performed to rule out microvascular diabetic complications (retinal and peripheral nerves), metabolic control, kidney function and vitamin D status and examine their association with ApFFM and function. ApFFM was significantly higher among DM2 female patients and lower among diabetic men. However opposite results were obtained when individual values were corrected for body mass index (BMI), specifically among women, who were more likely to be obese. As for muscle strength and global functionality tests, significantly better performances in TUG, 12MW, QS and HS were observed among ND subjects of both sexes. These differences prevailed even after excluding diabetic patients with microvascular complications as well as those with more than 10years of diabetes. Muscle quality was also significantly better among ND women. Higher scores of pain and stiffness in the WOMAC scale correlated with 12MW and TUG in both groups but

  11. Strength Exercise Improves Muscle Mass and Hepatic Insulin Sensitivity in Obese Youth

    Van Der Heijden, Gert-Jan; Wang, Zhiyue J.; Chu, Zili; Toffolo, Gianna; Manesso, Erica; Sauer, Pieter J. J.; Sunehag, Agneta L.

    VAN DER HEIJDEN, G.-J., Z. J. WANG, Z. CHU, G. TOFFOLO, E. MANESSO, P. J. J. SAUER, and A. L. SUNEHAG. Strength Exercise Improves Muscle Mass and Hepatic Insulin Sensitivity in Obese Youth. Med. Sci. Sports Exerc., Vol. 42, No. 11, pp. 1973-1980, 2010. Introduction: Data on the metabolic effects of

  12. Postoperative loss of skeletal muscle mass, complications and quality of life in patients undergoing cardiac surgery

    van Venrooij, Lenny M. W.; Verberne, Hein J.; de Vos, Rien; Borgmeijer-Hoelen, Mieke M. M. J.; van Leeuwen, Paul A. M.; de Mol, Bas A. J. M.

    2012-01-01

    Objective: The objective of this study was to describe postoperative undernutrition in terms of postoperative losses of appendicular skeletal muscle mass (ASMM) with respect to complications, quality of life, readmission, and 1-y mortality after cardiac surgery. Methods: Patients undergoing cardiac

  13. Middle cerebral artery blood velocity depends on cardiac output during exercise with a large muscle mass

    Ide, K.; Pott, F.; van Lieshout, J. J.; Secher, N. H.

    1998-01-01

    We tested the hypothesis that pharmacological reduction of the increase in cardiac output during dynamic exercise with a large muscle mass would influence the cerebral blood velocity/perfusion. We studied the relationship between changes in cerebral blood velocity (transcranial Doppler), rectus

  14. Strength Exercise Improves Muscle Mass and Hepatic Insulin Sensitivity in Obese Youth

    Van Der Heijden, Gert-Jan; Wang, Zhiyue J.; Chu, Zili; Toffolo, Gianna; Manesso, Erica; Sauer, Pieter J. J.; Sunehag, Agneta L.

    2010-01-01

    VAN DER HEIJDEN, G.-J., Z. J. WANG, Z. CHU, G. TOFFOLO, E. MANESSO, P. J. J. SAUER, and A. L. SUNEHAG. Strength Exercise Improves Muscle Mass and Hepatic Insulin Sensitivity in Obese Youth. Med. Sci. Sports Exerc., Vol. 42, No. 11, pp. 1973-1980, 2010. Introduction: Data on the metabolic effects of

  15. Does Skeletal Muscle Mass Influence Breast Cancer? Evaluating Mammary Tumorigenesis and Progression Genetically Hyper-Muscular Mice

    2006-07-01

    the skeletal muscle-specific muscle growth inhibitor myostatin and mice expressing a dominant negative form of the myostatin receptor, Activin...and rates of breast cancer initiation and progression. 15. SUBJECT TERMS Breast cancer, skeletal muscle, myostatin , MPA, DMBA, Activin receptor 16...including interleukins, Insulin-like Growth Factor (IGF) isoforms, IGF-binding proteins and myostatin . To determine the effect of skeletal muscle mass

  16. Signalling pathways regulating muscle mass in ageing skeletal muscle. The role of the IGF1-Akt-mTOR-FoxO pathway

    Sandri, M.; Barberi, L.; Bijlsma, A.Y.; Blaauw, B.; Dyar, K.A.; Milan, G.; Mammucari, C.; Meskers, C.G.M.; Pallafacchina, G.; Paoli, A.; Pion, D.; Roceri, M.; Romanello, V.; Serrano, A.L.; Toniolo, L.; Larsson, L.; Maier, A.B.; Munoz-Canoves, P.; Musaro, A.; Pende, M.; Reggiani, C.; Rizzuto, R.; Schiaffino, S.

    2013-01-01

    During ageing skeletal muscles undergo a process of structural and functional remodelling that leads to sarcopenia, a syndrome characterized by loss of muscle mass and force and a major cause of physical frailty. To determine the causes of sarcopenia and identify potential targets for interventions

  17. The effect of protein intake and resistance training on muscle mass in acutely ill old medical patients - A randomized controlled trial

    Buhl, Sussi F; Andersen, Aino L; Andersen, Jens Rikardt

    2016-01-01

    admission and a daily protein supplement (18.8 g protein) and resistance training 3 times per week the 12 weeks following discharge. Muscle mass was assessed by Dual-energy X-ray Absorptiometry. Muscle strength was assessed by Hand Grip Strength and Chair Stand Test. Functional ability was assessed...... mass (unadjusted: β-coefficient = -1.28 P = 0.32, adjusted for gender: β-coefficient = -0.02 P = 0.99, adjusted for baseline lean mass: β-coefficient = -0.31 P = 0.80). The de Morton Mobility Index significantly increased in the Control Group (β-coefficient = -11.43 CI: 0.72-22.13, P = 0.04). No other...... differences were found. CONCLUSION: No significant effect on muscle mass was observed in this group of acutely ill old medical patients. High compliance was achieved with the dietary intervention, but resistance training was challenging. Clinical trials identifier NCT02077491....

  18. Age associated declines in muscle mass, strength, power, and physical performance: impact on fear of falling and quality of life

    SUMMARY: This 3 year longitudinal study among older adults showed that declining muscle mass, strength, power, and physical performance are independent contributing factors to increased fear of falling, while declines of muscle mass and physical performance contribute to deterioration of quality of ...

  19. Pro-inflammatory capacity of classically activated monocytes relates positively to muscle mass and strength.

    Beenakker, Karel G M; Westendorp, Rudi G J; de Craen, Anton J M; Slagboom, Pieternella E; van Heemst, Diana; Maier, Andrea B

    2013-08-01

    In mice, monocytes that exhibit a pro-inflammatory profile enter muscle tissue after muscle injury and are crucial for clearance of necrotic tissue and stimulation of muscle progenitor cell proliferation and differentiation. The aim of this study was to test if pro-inflammatory capacity of classically activated (M1) monocytes relates to muscle mass and strength in humans. This study included 191 male and 195 female subjects (mean age 64.2 years (SD 6.4) and 61.9 ± 6.4, respectively) of the Leiden Longevity Study. Pro-inflammatory capacity of M1 monocytes was assessed by ex vivo stimulation of whole blood with Toll-like receptor (TLR) 4 agonist lipopolysaccharide (LPS) and TLR-2/1 agonist tripalmitoyl-S-glycerylcysteine (Pam₃Cys-SK₄), both M1 phenotype activators. Cytokines that stimulate M1 monocyte response (IFN-γ and GM-CSF) as well as cytokines that are secreted by M1 monocytes (IL-6, TNF-α, IL-12, and IL-1β) were measured. Analyses were adjusted for age, height, and body fat mass. Upon stimulation with LPS, the cytokine production capacity of INF-γ, GM-CSF, and TNF-α was significantly positively associated with lean body mass, appendicular lean mass and handgrip strength in men, but not in women. Upon stimulation with Pam₃Cys-SK₄, IL-6; TNF-α; and Il-1β were significantly positively associated with lean body mass and appendicular lean in women, but not in men. Taken together, this study shows that higher pro-inflammatory capacity of M1 monocytes upon stimulation is associated with muscle characteristics and sex dependent. © 2013 John Wiley & Sons Ltd and the Anatomical Society.

  20. Age-related differences in lean mass, protein synthesis and skeletal muscle markers of proteolysis after bed rest and exercise rehabilitation.

    Tanner, Ruth E; Brunker, Lucille B; Agergaard, Jakob; Barrows, Katherine M; Briggs, Robert A; Kwon, Oh Sung; Young, Laura M; Hopkins, Paul N; Volpi, Elena; Marcus, Robin L; LaStayo, Paul C; Drummond, Micah J

    2015-09-15

    Bed rest-induced muscle loss and impaired muscle recovery may contribute to age-related sarcopenia. It is unknown if there are age-related differences in muscle mass and muscle anabolic and catabolic responses to bed rest. A secondary objective was to determine if rehabilitation could reverse bed rest responses. Nine older and fourteen young adults participated in a 5-day bed rest challenge (BED REST). This was followed by 8 weeks of high intensity resistance exercise (REHAB). Leg lean mass (via dual-energy X-ray absorptiometry; DXA) and strength were determined. Muscle biopsies were collected during a constant stable isotope infusion in the postabsorptive state and after essential amino acid (EAA) ingestion on three occasions: before (PRE), after bed rest and after rehabilitation. Samples were assessed for protein synthesis, mTORC1 signalling, REDD1/2 expression and molecular markers related to muscle proteolysis (MURF1, MAFBX, AMPKα, LC3II/I, Beclin1). We found that leg lean mass and strength decreased in older but not younger adults after bedrest (P protein synthesis increased before bed rest in both age groups (P protein synthesis rates and increased MAFBX mRNA, p-AMPKα and the LC3II/I ratio (P protein synthesis and a marginal increase in proteolytic markers. Finally, rehabilitation restored bed rest-induced deficits in lean mass and strength in older adults. © 2015 The Authors. The Journal of Physiology © 2015 The Physiological Society.

  1. The Association between Total Protein and Vegetable Protein Intake and Low Muscle Mass among the Community-Dwelling Elderly Population in Northern Taiwan

    Ru-Yi Huang

    2016-06-01

    Full Text Available Sarcopenia, highly linked with fall, frailty, and disease burden, is an emerging problem in aging society. Higher protein intake has been suggested to maintain nitrogen balance. Our objective was to investigate whether pre-sarcopenia status was associated with lower protein intake. A total of 327 community-dwelling elderly people were recruited for a cross-sectional study. We adopted the multivariate nutrient density model to identify associations between low muscle mass and dietary protein intake. The general linear regression models were applied to estimate skeletal muscle mass index across the quartiles of total protein and vegetable protein density. Participants with diets in the lowest quartile of total protein density (<13.2% were at a higher risk for low muscle mass (odds ratio (OR 3.03, 95% confidence interval (CI 1.37–6.72 than those with diets in the highest quartile (≥17.2%. Similarly, participants with diets in the lowest quartile of vegetable protein density (<5.8% were at a higher risk for low muscle mass (OR 2.34, 95% CI 1.14–4.83 than those with diets in the highest quartile (≥9.4%. Furthermore, the estimated skeletal muscle mass index increased significantly across the quartiles of total protein density (p = 0.023 and vegetable protein density (p = 0.025. Increasing daily intakes of total protein and vegetable protein densities appears to confer protection against pre-sarcopenia status.

  2. Protein needs in athletes and dietary-nutrition guidelines to gain muscle mass

    Aritz Urdampilleta

    2014-05-01

    Full Text Available One of the most important effects of strength training is muscular hypertrophy. Athletes should optimize their nutritional management in order to compensate their own genetic limitations. The aim of this review is to analyze the scientific evidence concerning protein intake as a tool to achieve muscle hypertrophy. Depending on the expenditure and energy intake of athlete, a daily protein ranging between 10-15% of total dietary intake is needed. However in sports diets, it is preferable to estimate the amount of protein needed per kilogram of body weight in each individual. In this regard athletes should ingest an amount between 1.2 g and 1.8 g of proteins/kg of body mass/day to maintain their lean mass. In order to increase muscle mass (0.5 kg/week, athletes should take between 1.6 g and 1.8 g of protein/kg/day with an increase of 400-500 kcal in their daily diet. These needs will depend on the sport, muscular catabolic status, the athlete’s lean mass and glycogen stores. Protein needs will increase if muscle and liver glycogen stores are empty. Excess of protein intake (more than 2 g/kg/day, with full glycogen stores, does not benefit the athlete and could cause an increase in circulating ketones and urea, thereby producing an early dehydration.

  3. Impact of fat mass distribution body shapes on muscles strength and the joints pain

    Zerf Mohammed

    2016-01-01

    Full Text Available Our study focuses on fat mass distribution body shapes type as measured to determine their effect on skeletal muscle strengthening lumbar extensors (upper and lower limbs where our background confirms that every girl has a natural body type of rectangle, apple, pear, or hourglass. It is good for her to know which type of body shape she is, so she can learn what exercises to do, whereas similar studies suggest that it is much better to challenge weight problems with exercise and dietary measures before resorting to figure shaping. For this purpose, our study was carried out with a total of thirty students, females listed in the Institute of Physical Education and Sport, University of Mostaganem, aged between 20 and 23 years; their homogeneity was based on age, sex, and academic specialty, classified based on the body mass index (BMI into two groups (normal and overweight and based on their body shape′s type into three groups (9 pear shape, 10 rectangle shape, and 11 hourglass shape as a protocol experimental to examine the impact of fat mass distribution body shapes type on lumbar extensor strength. Based on our data analysis, we confirm that the pear and the rectangle shape affect the strength lumbar extensors due to body weight distribution which increases the risks relating to the skeletal muscles. Weight gain is a factor contributing to the weakness of skeletal muscles. However, the body shape explains the anomalies of the distribution of fat mass and BMI risk observed in our sample in the lower and upper part of the body recorded by the values of Killy test and endurance of trunk, the case of the pear and the rectangle shape back pain, which are consisting in excess of the body fat distributed in comparison with less percentage of muscle mass. Whereas this difference can affect the pelvic position.

  4. Association between muscle mass and adipo-metabolic profile: a cross-sectional study in older subjects

    Perna S

    2015-02-01

    Full Text Available Simone Perna,1,* Davide Guido,2,* Mario Grassi,2 Mariangela Rondanelli1 1Department of Public Health, Experimental and Forensic Medicine, School of Medicine, Endocrinology and Nutrition Unit, University of Pavia, Azienda di Servizi alla Persona di Pavia, Pavia, Italy; 2Medical and Genomic Statistics Unit, Department of Brain and Behavioral Sciences, University of Pavia, Pavia, Italy *These authors contributed equally to this work Background: Sarcopenia, the decrease in muscle mass and function, may lead to various negative health outcomes in elderly. The association among sarcopenia with adiposity and metabolic markers has rarely been studied in the elderly population, with controversial results. The aim of this study is to evaluate this relationship in older subjects.Methods: A cross-sectional study was conducted in 290 elderly patients, focusing on the possible association between muscle mass loss, assessed by relative skeletal muscle mass (RSMM, and an adipo-metabolic profile (AMP defined by adiposity and metabolic biochemical markers. Measurements of body composition were assessed by dual energy X-ray absorptiometry. Biochemical parameters, such as albumin, low-density lipoprotein cholesterol, high-density lipoprotein cholesterol, total cholesterol, triglycerides, C-reactive protein, and homocysteine and its related markers (folate and vitamin B12 were measured. Using canonical correlation analysis and structural equation modeling, an individual score of AMP was created and correlated with RSMM.Results: The AMP–RSMM correlation was equal to +0.642 (95% confidence interval, +0.512 to +0.773; P<0.001. Hence, a negative association between sarcopenia severity and adiposity/metabolic biochemical markers was highlighted.Conclusion: This study contained a novel way to examine the relationship between the variables of interest based on a composite index of adiposity and metabolic conditions. Results shed light on the orientation and magnitude of

  5. Ultrasonographic evaluation of the calf muscle mass and architecture in elderly patients with and without sarcopenia.

    Kuyumcu, Mehmet Emin; Halil, Meltem; Kara, Özgür; Çuni, Bledjan; Çağlayan, Gökhan; Güven, Serdar; Yeşil, Yusuf; Arık, Güneş; Yavuz, Burcu Balam; Cankurtaran, Mustafa; Özçakar, Levent

    2016-01-01

    To sonographically assess the muscle mass and architecture of sarcopenic elderly subjects, and to explore the utility of ultrasound (US) measurements in predicting sarcopenia. One hundred elderly subjects were enrolled in this cross-sectional study. Mean age value of our study population was 73.08±6.18years. The diagnosis of sarcopenia was confirmed by measuring fat-free mass index (using bioelectrical impedance analysis) and handgrip strength. Calf circumference was measured and US evaluations comprised bilateral gastrocnemius muscle (MG) thickness, fascicle length and pennate angles; subcutaneous fat and dermis thicknesses in the calf. Bilateral muscle thickness and fascicle length values were significantly lower in patients with sarcopenia (both psarcopenia (all values>76.92%). Gastrocnemius muscle thickness and fascicle length values are lower in sarcopenic elderly and these two parameters can serve as alternative measurements for predicting/quantifying sarcopenia. Calf circumference measurements alone may not be appropriate for assessing sarcopenia. Instead, US imaging can conveniently be used to evaluate different compartments of the musculoskelal system in (sarcopenic) elderly. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  6. Circulating levels of TNF-alpha and IL-6-relation to truncal fat mass and muscle mass in healthy elderly individuals and in patients with type-2 diabetes

    Pedersen, Maria; Bruunsgaard, Helle; Weis, Nina

    2003-01-01

    The purpose of the current study was to test the hypothesis that an altered fat distribution in elderly healthy subjects and in patients with type-2 diabetes contributes to high circulating levels of interleukin (IL)-6 and tumor necrotic factor (TNF)-alpha, which secondly is related to lower muscle...... mass. Twenty young controls, (20-35 yr), 20 healthy elderly subjects (65-80 yr) and 16 elderly patients with type 2 diabetes (65-80 yr) were included in a cross sectional study. Plasma levels of TNF-alpha and IL-6 were measured after an overnight fast. Dual-energy X-ray absorptiometry and total body...... to lower ASM and BCM in elderly men both in a univariate regression analysis and a multivariate regression analysis. In conclusion, high plasma levels of TNF-alpha and IL-6 in elderly healthy people and in patients with type 2 diabetes are associated with increased truncal fat mass, suggesting...

  7. Hormonal and lifestyle determinants of appendicular skeletal muscle mass in men: the MINOS study.

    Szulc, Pawel; Duboeuf, François; Marchand, François; Delmas, Pierre D

    2004-08-01

    Aging-related sarcopenia is characterized by a loss of muscle mass and strength and increased fatigability. However, studies of its determinants in elderly men are scarce. We investigated risk factors for sarcopenia in a large cohort of men. We analyzed 845 men aged 45-85 y who belonged to the MINOS cohort. Lifestyle factors (physical activity, tobacco smoking, alcohol intake, caffeine intake) were evaluated by using a standardized questionnaire. Appendicular skeletal muscle mass (ASM) was estimated by using dual-energy X-ray absorptiometry. The relative appendicular skeletal muscle mass index (RASM) was calculated as ASM/body height(2.3). Apparent free testosterone concentration (AFTC) and free testosterone index (FTI) were calculated on the basis of concentrations of total testosterone and sex hormone-binding globulin. RASM decreased with age (r = -0.29, P values for AFTC, FTI, or 25-hydroxycholecalciferol [25(OH)D] were >2 SDs below the mean for young men had significantly lower RASM than did men with higher values. Men with sarcopenia, defined as the lowest quartile of RASM in the studied cohort (normal RASM, weighed significantly less, smoked more, and spent significantly less time on leisure-time activities. Sarcopenic men also had lower values for testosterone, AFTC, FTI, and 25(OH)D. In elderly men, low physical activity, tobacco smoking, thinness, low testosterone (AFTC and FTI), and decreased 25(OH)D concentrations are risk factors for sarcopenia.

  8. Age- and gender-dependent values of skeletal muscle mass in healthy children and adolescents

    Webber, Colin E.; Barr, Ronald D.

    2011-01-01

    Background Skeletal muscle mass (SMM) can be extracted from whole-body scans obtained by X-ray-based dual-photon absorptiometry (DXA). There is a need to establish expected age-dependent values for children and adolescents. Methods Appendicular lean tissue mass (ALM) was extracted from whole-body DXA scans in 140 healthy children and adolescents (68 females and 72 males). Whole-body SMM was calculated from ALM using equations developed by Kim et al. (Am J Clin Nutr 84:1014–1020, 2006). Age-de...

  9. The Influence of High-Frequency Gravitational Waves Upon Muscles

    Moy, Lawrence S.; Baker, Robert M. L. Jr

    2007-01-01

    The objective of this paper is to present a theory for the possible influence of high-frequency gravitational waves or HFGWs and pulsed micro-current electromagnetic waves or EMs on biological matter specifically on muscle cells and myofibroblasts. The theory involves consideration of the natural frequency of contractions and relaxations of muscles, especially underlying facial skin, and the possible influence of HFGWs on that process. GWs pass without attenuation through all material thus conventional wisdom would dictate that GWs would have no influence on biological matter. On the other hand, GWs can temporarily modify a gravitational field in some locality if they are of high frequency and such a modification might have an influence in changing the skin muscles' natural frequency. Prior to the actual laboratory generation of HFGWs their influence can be emulated by micro-current EM pulses to the skin and some evidence presented here on that effect may predict the influence of HFGWs. We believe that the HFGW pulsations lead to increased muscle activity and may serve to reverse the aging process. A novel theoretical framework concerning these relaxation phenomena is one result of the paper. Another result is the analysis of the possible delivery system of the FBAR-generated HFGWs, the actual power of the generated HFGWs, and the system's application to nanostructural modification of the skin or muscle cells. It is concluded that a series of non-evasive experiments, which are identified, will have the potential to test theory by detecting and analyzing the possible HFGWs change in polarization, refraction, etc. after their interaction with the muscle cells

  10. Measurement of Muscle Protein Fractional Synthetic Rate by Capillary Gas Chromatography/Combustion Isotope Ratio Mass Spectrometry

    Yarasheski, Kevin E.; Smith, Kenneth; Rennie, Michael J.; Bier, Dennis M.

    1992-01-01

    The measurement of skeletal muscle protein fractional synthetic rate using an infusion of (1-13C)leucine and measuring the isotopic abundance of the tracer in skeletal muscle protein by preparative gas chromatography (GC)/ninhydrin isotope ratio mass spectrometry (IRMS) is laborious and subject to errors owing to contamination by 12C. The purpose of this study was to compare muscle (13C)leucine enrichment measured with the conventional preparative GC/ninhydrin IRMS approach to a new, continuo...

  11. Time-Course of Muscle Mass Loss, Damage, and Proteolysis in Gastrocnemius following Unloading and Reloading: Implications in Chronic Diseases

    Chacon-Cabrera, Alba; Lund-Palau, Helena; Gea, Joaquim; Barreiro, Esther

    2016-01-01

    Background Disuse muscle atrophy is a major comorbidity in patients with chronic diseases including cancer. We sought to explore the kinetics of molecular mechanisms shown to be involved in muscle mass loss throughout time in a mouse model of disuse muscle atrophy and recovery following immobilization. Methods Body and muscle weights, grip strength, muscle phenotype (fiber type composition and morphometry and muscle structural alterations), proteolysis, contractile proteins, systemic troponin I, and mitochondrial content were assessed in gastrocnemius of mice exposed to periods (1, 2, 3, 7, 15 and 30 days) of non-invasive hindlimb immobilization (plastic splint, I cohorts) and in those exposed to reloading for different time-points (1, 3, 7, 15, and 30 days, R cohorts) following a seven-day period of immobilization. Groups of control animals were also used. Results Compared to non-exposed controls, muscle weight, limb strength, slow- and fast-twitch cross-sectional areas, mtDNA/nDNA, and myosin content were decreased in mice of I cohorts, whereas tyrosine release, ubiquitin-proteasome activity, muscle injury and systemic troponin I levels were increased. Gastrocnemius reloading following splint removal improved muscle mass loss, strength, fiber atrophy, injury, myosin content, and mtDNA/nDNA, while reducing ubiquitin-proteasome activity and proteolysis. Conclusions A consistent program of molecular and cellular events leading to reduced gastrocnemius muscle mass and mitochondrial content and reduced strength, enhanced proteolysis, and injury, was seen in this non-invasive mouse model of disuse muscle atrophy. Unloading of the muscle following removal of the splint significantly improved the alterations seen during unloading, characterized by a specific kinetic profile of molecular events involved in muscle regeneration. These findings have implications in patients with chronic diseases including cancer in whom physical activity may be severely compromised. PMID

  12. Muscle mass decline, arterial stiffness, white matter hyperintensity, and cognitive impairment: Japan Shimanami Health Promoting Program study.

    Kohara, Katsuhiko; Okada, Yoko; Ochi, Masayuki; Ohara, Maya; Nagai, Tokihisa; Tabara, Yasuharu; Igase, Michiya

    2017-08-01

    There is a close association between frailty and cognitive impairment. However, the underlying contribution of sarcopenia to the development of cognitive impairment is unclear. We investigated the possible association between muscle mass decline and cognitive impairment in a cross-sectional study of 1518 subjects aged 55 years or above. We also evaluated arterial stiffness and white matter hyperintensities (WMHs) as possible underlying mechanisms for this association. Two sarcopenic indices were measured: thigh muscle cross-sectional area (CSA; calculated by computed tomography) and skeletal muscle mass (bioelectric impedance). Muscle mass decline was defined as either the bottom 10% or 20% of participants for each sex. Cognitive function was assessed using the Touch Panel-type Dementia Assessment Scale, and brachial-ankle pulse wave velocity was measured as an index of arterial stiffness. Both sarcopenic indices were modestly but significantly associated with brachial-ankle pulse wave velocity in male and female subjects. The presence of WMHs was significantly associated with low thigh muscle CSA in men and with low skeletal muscle mass in women. The Touch Panel-type Dementia Assessment Scale score was modestly but significantly and positively associated with thigh muscle CSA in men and skeletal muscle mass in women. Muscle mass decline in the bottom 10% of participants on both sarcopenic indices was significantly and independently related to cognitive impairment in women. Lower sarcopenic indices are significantly related to lower cognitive scores. Arterial stiffness and WMHs could account, at least in part, for this association. © 2017 The Authors. Journal of Cachexia, Sarcopenia and Muscle published by John Wiley & Sons Ltd on behalf of the Society on Sarcopenia, Cachexia and Wasting Disorders.

  13. Skeletal muscle mass and quality as risk factors for postoperative outcome after open colon resection for cancer

    Boer, B. C.; de Graaff, F.; Brusse-Keizer, M.; Bouman, D. E.; Slump, C. H.; Slee-Valentijn, M.; Klaase, J. M.

    The prevalence of colorectal cancer in the elderly is increasing and, therefore, surgical interventions with a risk of potential complications are more frequently performed. This study investigated the role of low skeletal muscle mass (sarcopenia), muscle quality, and the sarcopenic obesity as

  14. Loss of Muscle Mass During Chemotherapy Is Predictive for Poor Survival of Patients With Metastatic Colorectal Cancer

    Blauwhoff-Buskermolen, Susanne; Versteeg, Kathelijn S.; de van der Schueren, Marian A. E.; den Braver, Nicole R.; Berkhof, Johannes; Langius, Jacqueline A. E.; Verheul, Henk M. W.

    2016-01-01

    Low muscle mass is present in approximately 40% of patients with metastatic colorectal cancer (mCRC) and may be associated with poor outcome. We studied change in skeletal muscle during palliative chemotherapy in patients with mCRC and its association with treatment modifications and overall

  15. LOW MID-UPPER ARM CIRCUMFERENCE AND MORTALITY IN OLDER PERSONS: THE INFLUENCE OF FAT AND MUSCLE MASS

    Delmonico, M.J.; Harris, T.B.; Visser, M.; Park, S.W.; Conroy, M.B.; Velasquez-Mieyer, P.; Boudreau, R.; Manini, T.M.; Nevitt, M.; Newman, A.B.; Goodpaster, B.H.

    2009-01-01

    Background: Sarcopenia is thought to be accompanied by increased muscle fat infiltration. However, no longitudinal studies have examined concomitant changes in muscle mass, strength, or fat infiltration in older adults. Objective: We present longitudinal data on age-related changes in leg

  16. COMPARISON OF HAMSTRING MUSCLE ACTIVATION DURING HIGH-SPEED RUNNING AND VARIOUS HAMSTRING STRENGTHENING EXERCISES

    Solheim, Jens Asmund Brevik; Bencke, Jesper

    2017-01-01

    Purpose/Background Several studies have examined the effect of hamstring strength exercises upon hamstring strains in team sports that involve many sprints. However, there has been no cross comparison among muscle activation of these hamstring training exercises with actual sprinting. Therefore, the aim of this study was to examine different hamstring exercises and compare the muscle activity in the hamstring muscle group during various exercises with the muscular activity produced during maximal sprints. Methods Twelve male sports students (age 25 ± 6.2 years, 1.80 ± 7.1 m, body mass 81.1 ± 15.6 kg) participated in this study. Surface EMG electrodes were placed on semimembranosus, semitendinosus and biceps femoris to measure muscle activity during seven hamstrings exercises and sprinting together with 3D motion capture to establish at what hip and knee angles maximal muscle activation (EMG) occurs. Maximal EMG activity during sprints for each muscle was used in order to express each exercise as a percentage of max activation during sprinting. Results The main findings were that maximal EMG activity of the different hamstring exercises were on average between 40-65% (Semitendinosus), 18-40% (biceps femoris) and 40-75% (Semimembranosus) compared with the max EMG activity in sprints, which were considered as 100%. The laying kick together with the Nordic hamstring exercises and its variations had the highest muscle activations, while the cranes showed the lowest muscle activation (in all muscles) together with the standing kick for the semimembranosus. In addition, angles at which the peak EMG activity of the hamstring muscle occurs were similar for the Nordic hamstring exercises and different for the two crane exercises (hip angle), standing kick (hip angle) and the laying kick (knee angle) compared with the sprint. Conclusions Nordic hamstring exercises with its variation together with the laying kick activates the hamstrings at high levels and

  17. Quantitative phosphoproteomic analysis of caprine muscle with high and low meat quality.

    Liu, Manshun; Wei, Yanchao; Li, Xin; Quek, Siew Young; Zhao, Jing; Zhong, Huazhen; Zhang, Dequan; Liu, Yongfeng

    2018-07-01

    During the conversion of muscle to meat, protein phosphorylation can regulate various biological processes that have important effects on meat quality. To investigate the phosphorylation pattern of protein on rigor mortis, goat longissimus thoracis and external intercostals were classified into two groups (high quality and low quality), and meat quality was evaluated according to meat quality attributes (Warner-Bratzler shear force, Color, pH and drip loss). A quantitative mass spectrometry-based phosphoproteomic study was conducted to analyze the caprine muscle at 12h postmortem applying the TiO 2 -SIMAC-HILIC (TiSH) phosphopeptide enrichment strategy. A total of 2125 phosphopeptides were identified from 750 phosphoproteins. Among them, 96 proteins had differed in phosphorylation levels. The majority of these proteins are involved in glucose metabolism and muscle contraction. The differential phosphorylation level of proteins (PFK, MYL2 and HSP27) in two groups may be the crucial factors of regulating muscle rigor mortis. This study provides a comprehensive view for the phosphorylation status of caprine muscle at rigor mortis, it also gives a better understanding of the regulation of protein phosphorylation on various biological processes that affect the final meat quality attributes. Copyright © 2018. Published by Elsevier Ltd.

  18. Influence of muscle strength, physical activity and weight on bone mass in a population-based sample of 1004 elderly women.

    Gerdhem, P; Ringsberg, K A M; Akesson, K; Obrant, K J

    2003-09-01

    High physical activity level has been associated with high bone mass and low fracture risk and is therefore recommended to reduce fractures in old age. The aim of this study was to estimate the effect of potentially modifiable variables, such as physical activity, muscle strength, muscle mass and weight, on bone mass in elderly women. The influence of isometric thigh muscle strength, self-estimated activity level, body composition and weight on bone mineral density (dual energy X-ray absorptiometry; DXA) in total body, hip and spine was investigated. Subjects were 1004 women, all 75 years old, taking part in the Malmö Osteoporosis Prospective Risk Assessment (OPRA) study. Physical activity and muscle strength accounted for 1-6% of the variability in bone mass, whereas weight, and its closely associated variables lean mass and fat mass, to a much greater extent explained the bone mass variability. We found current body weight to be the variable with the most substantial influence on the total variability in bone mass (15-32% depending on skeletal site) in a forward stepwise regression model. Our findings suggest that in elderly women, the major fracture-preventive effect of physical activity is unlikely to be mediated through increased bone mass. Retaining or even increasing body weight is likely to be beneficial to the skeleton, but an excess body weight increase may have negative effects on health. Nevertheless, training in elderly women may have advantages by improving balance, co-ordination and mobility and therefore decreasing the risk of fractures.

  19. Statin-associated muscle symptoms-Managing the highly intolerant.

    Backes, James M; Ruisinger, Janelle F; Gibson, Cheryl A; Moriarty, Patrick M

    Musculoskeletal symptoms are the most commonly reported adverse effects associated with statin therapy. Yet, certain data indicate that these symptoms often present in populations with underlying musculoskeletal complaints and are not likely statin related. Switching statins or using lower doses resolves muscle complaints in most patients. However, there is a growing population of individuals who experience intolerable musculoskeletal symptoms with multiple statins, regardless of the individual agent or prescribed dose. Recent randomized, placebo-controlled trials enrolling highly intolerant subjects provide significant insight regarding statin-associated muscle symptoms (SAMS). Notable findings include the inconsistency with reproducing muscle complaints, as approximately 40% of subjects report SAMS when taking a statin but not while receiving placebo, but a substantial cohort reports intolerable muscle symptoms with placebo but none when on a statin. These data validate SAMS for those likely experiencing true intolerance, but for others, suggest a psychosomatic component or misattribution of the source of pain and highlights the importance of differentiating from the musculoskeletal symptoms caused by concomitant factors. Managing the highly intolerant requires candid patient counseling, shared decision-making, eliminating contributing factors, careful clinical assessment and the use of a myalgia index score, and isolating potential muscle-related adverse events by gradually reintroducing drug therapy with the utilization of intermittent dosing of lipid-altering agents. We provide a review of recent data and therapeutic guidance involving a focused step-by-step approach for managing SAMS among the highly intolerant. Such strategies usually allow for clinically meaningful reductions in low-density lipoprotein cholesterol and an overall lowering of cardiovascular risk. Copyright © 2017 National Lipid Association. Published by Elsevier Inc. All rights reserved.

  20. The effects of dietary protein intake on appendicular lean mass and muscle function in elderly men

    Mitchell, Cameron J; Milan, Amber M; Mitchell, Sarah M

    2017-01-01

    Background: The Recommended Daily Allowance (RDA) for protein intake in the adult population is widely promoted as 0.8 g · kg-1 · d-1 Aging may increase protein requirements, particularly to maintain muscle mass.Objective: We investigated whether controlled protein consumption at the current RDA...... or twice the RDA (2RDA) affects skeletal muscle mass and physical function in elderly men.Design: In this parallel-group randomized trial, 29 men aged >70 y [mean ± SD body mass index (in kg/m2): 28.3 ± 4.2] were provided with a complete diet containing either 0.8 (RDA) or 1.6 (2RDA) g protein · kg-1 · d-1...... energy balance (mean ± SD RDA: 209 ± 213 kcal/d; 2RDA 145 ± 214 kcal/d; P= 0.427 for difference between the groups). In comparison with RDA, whole-body lean mass increased in 2RDA (P = 0.001; 1.49 ± 1.30 kg, P

  1. Texture-modified diets are associated with decreased muscle mass in older adults admitted to a rehabilitation ward.

    Shimizu, Akio; Maeda, Keisuke; Tanaka, Kei; Ogawa, Mei; Kayashita, Jun

    2018-05-01

    Texture-modified diets (TMD) have significantly lower energy and protein content than normal diets. Therefore, TMD can cause malnutrition and loss of muscle mass. However, few studies have reported the relationship between TMD and decreased skeletal muscle mass. The aim of the present study was to clarify the association between TMD and decreased skeletal muscle mass. We reviewed data of 188 older adult patients who were admitted to a rehabilitation hospital. TMD were defined based on the Japanese Dysphagia Diet Criteria 2013 proposed by the Japanese Society of Dysphagia Rehabilitation. The Mini Nutritional Assessment-Short Form was used to assess nutritional status; dual-energy X-ray absorptiometry was used to measure the skeletal muscle mass index, and the cut-off values for decreased skeletal muscle mass index were based on the Asian Working Group for Sarcopenia; the Functional Independence Measure was used to evaluate activities of daily living. The patients' mean age was 80.6 ± 7.5 years, and 62% were women. A total of 22 patients (11.7%) consumed TMD. A total of 104 patients (55.3%) had decreased skeletal muscle mass, and approximately 90% of them consumed TMD. Decreased skeletal muscle mass index (odds ratio 7.199, 95% confidence interval 1.489-34.805, P ≤ 0.01) and Functional Independence Measure scores (odds ratio 0.972, 95% confidence interval 0.952-0.992, P ≤ 0.01) were independently related to TMD in the multivariate analysis. The TMD group was associated with decreased skeletal muscle mass. Future, prospective studies are necessary to investigate causality. Geriatr Gerontol Int 2018; 18: 698-704. © 2017 Japan Geriatrics Society.

  2. A mouse anti-myostatin antibody increases muscle mass and improves muscle strength and contractility in the mdx mouse model of Duchenne muscular dystrophy and its humanized equivalent, domagrozumab (PF-06252616), increases muscle volume in cynomolgus monkeys.

    St Andre, Michael; Johnson, Mark; Bansal, Prashant N; Wellen, Jeremy; Robertson, Andrew; Opsahl, Alan; Burch, Peter M; Bialek, Peter; Morris, Carl; Owens, Jane

    2017-11-09

    The treatments currently approved for Duchenne muscular dystrophy (DMD), a progressive skeletal muscle wasting disease, address the needs of only a small proportion of patients resulting in an urgent need for therapies that benefit all patients regardless of the underlying mutation. Myostatin is a member of the transforming growth factor-β (TGF-β) family of ligands and is a negative regulator of skeletal muscle mass. Loss of myostatin has been shown to increase muscle mass and improve muscle function in both normal and dystrophic mice. Therefore, myostatin blockade via a specific antibody could ameliorate the muscle weakness in DMD patients by increasing skeletal muscle mass and function, thereby reducing patients' functional decline. A murine anti-myostatin antibody, mRK35, and its humanized analog, domagrozumab, were developed and their ability to inhibit several TGB-β ligands was measured using a cell-based Smad-activity reporter system. Normal and mdx mice were treated with mRK35 to examine the antibody's effect on body weight, lean mass, muscle weights, grip strength, ex vivo force production, and fiber size. The humanized analog (domagrozumab) was tested in non-human primates (NHPs) for changes in skeletal muscle mass and volume as well as target engagement via modulation of circulating myostatin. Both the murine and human antibodies are specific and potent inhibitors of myostatin and GDF11. mRK35 is able to increase body weight, lean mass, and muscle weights in normal mice. In mdx mice, mRK35 significantly increased body weight, muscle weights, grip strength, and ex vivo force production in the extensor digitorum longus (EDL) muscle. Further, tibialis anterior (TA) fiber size was significantly increased. NHPs treated with domagrozumab demonstrated a dose-dependent increase in lean mass and muscle volume and exhibited increased circulating levels of myostatin demonstrating target engagement. We demonstrated that the potent anti-myostatin antibody mRK35 and

  3. Green tea extracts ameliorate high-fat diet-induced muscle atrophy in senescence-accelerated mouse prone-8 mice.

    Onishi, Shintaro; Ishino, Mayu; Kitazawa, Hidefumi; Yoto, Ai; Shimba, Yuki; Mochizuki, Yusuke; Unno, Keiko; Meguro, Shinichi; Tokimitsu, Ichiro; Miura, Shinji

    2018-01-01

    Muscle atrophy (loss of skeletal muscle mass) causes progressive deterioration of skeletal function. Recently, excessive intake of fats was suggested to induce insulin resistance, followed by muscle atrophy. Green tea extracts (GTEs), which contain polyphenols such as epigallocatechin gallate, have beneficial effects on obesity, hyperglycemia, and insulin resistance, but their effects against muscle atrophy are still unclear. Here, we found that GTEs prevented high-fat (HF) diet-induced muscle weight loss in senescence-accelerated mouse prone-8 (SAMP8), a murine model of senescence. SAMP8 mice were fed a control diet, an HF diet, or HF with 0.5% GTEs (HFGT) diet for 4 months. The HF diet induced muscle weight loss with aging (measured as quadriceps muscle weight), whereas GTEs prevented this loss. In HF diet-fed mice, blood glucose and plasma insulin concentrations increased in comparison with the control group, and these mice had insulin resistance as determined by homeostasis model assessment of insulin resistance (HOMA-IR). In these mice, serum concentrations of leukocyte cell-derived chemotaxin 2 (LECT2), which is known to induce insulin resistance in skeletal muscle, were elevated, and insulin signaling in muscle, as determined by the phosphorylation levels of Akt and p70 S6 kinases, tended to be decreased. In HFGT diet-fed mice, these signs of insulin resistance and elevation of serum LECT2 were not observed. Although our study did not directly show the effect of serum LECT2 on muscle weight, insulin resistance examined using HOMA-IR indicated an intervention effect of serum LECT2 on muscle weight, as revealed by partial correlation analysis. Accordingly, GTEs might have beneficial effects on age-related and HF diet-induced muscle weight loss, which correlates with insulin resistance and is accompanied by a change in serum LECT2.

  4. Highly multiparametric analysis by mass cytometry.

    Ornatsky, Olga; Bandura, Dmitry; Baranov, Vladimir; Nitz, Mark; Winnik, Mitchell A; Tanner, Scott

    2010-09-30

    This review paper describes a new technology, mass cytometry, that addresses applications typically run by flow cytometer analyzers, but extends the capability to highly multiparametric analysis. The detection technology is based on atomic mass spectrometry. It offers quantitation, specificity and dynamic range of mass spectrometry in a format that is familiar to flow cytometry practitioners. The mass cytometer does not require compensation, allowing the application of statistical techniques; this has been impossible given the constraints of fluorescence noise with traditional cytometry instruments. Instead of "colors" the mass cytometer "reads" the stable isotope tags attached to antibodies using metal-chelating labeling reagents. Because there are many available stable isotopes, and the mass spectrometer provides exquisite resolution between detection channels, many parameters can be measured as easily as one. For example, in a single tube the technique allows for the ready detection and characterization of the major cell subsets in blood or bone marrow. Here we describe mass cytometric immunophenotyping of human leukemia cell lines and leukemia patient samples, differential cell analysis of normal peripheral and umbilical cord blood; intracellular protein identification and metal-encoded bead arrays. Copyright © 2010 Elsevier B.V. All rights reserved.

  5. Vector Boson Scattering at High Mass

    Sherwood, P

    2009-01-01

    In the absence of a light Higgs boson, the mechanism of electroweak symmetry breaking will be best studied in processes of vector boson scattering at high mass. Various models predict resonances in this channel. Here, we investigate W W scalar and vector resonances, W Z vector resonances and a Z Z scalar resonance over a range of diboson centre-of-mass energies. Particular attention is paid to the application reconstruction of dijet pairs with low opening angle resulting from the decay of highly boosted vector bosons.

  6. Lean muscle mass in classic or ovulatory PCOS: association with central obesity and insulin resistance.

    Mario, F M; do Amarante, F; Toscani, M K; Spritzer, P M

    2012-10-01

    This age-matched case-control study assessed total and segmental lean muscle mass in classic or ovulatory polycystic ovary syndrome (PCOS) patients and investigated whether lean mass is associated with hormone and metabolic features. Participants underwent anthropometric and clinical evaluation. Habitual physical activity was assessed with a digital pedometer, and body composition by dual-energy X-ray absorptiometry. Laboratory measurements included total cholesterol, cholesterol fractions, triglycerides, glucose, total serum testosterone, serum insulin, estradiol, luteinizing hormone, and SHBG. Energy intake was calculated using a food frequency questionnaire. Classic PCOS patients had higher body mass index (BMI), waist circumference, testosterone and lipid accumulation product values than ovulatory PCOS and controls. Energy consumption, homeostasis model assessment index, SHBG, free androgen index and triglycerides, total and trunk lean mass were higher only in classic PCOS women vs. controls. Arm, leg, trunk, total or limb lean masses were not correlated with hormone levels in any of the groups. However, in PCOS women lipid accumulation product was positively correlated with total (r=0.56, p=0.001), trunk (r=0.59, p=0.001), arm (r=0.54, p=0.001), leg (r=0.44, p=0.03) and limb (r=0.48, p=0.001) lean masses. BMI was positively correlated with all lean mass segments and independently associated with total lean mass. Lipid accumulation product and BMI were independently associated with trunk lean mass variation. The increase in lean mass in classic PCOS appears to be associated with insulin resistance and central obesity rather than with energy intake, physical activity or androgens. © J. A. Barth Verlag in Georg Thieme Verlag KG Stuttgart · New York.

  7. Initial Presentation of Renal Cell Carcinoma as a Metastatic Mass within the Masseter Muscle: A Case Report and Literature Review

    Bae, Kyung Eun; Lee, Han Bee; Cho, Woo Ho; Kim, Jae Hyung; Lee, Ji Hae; Kang, Min Jin [Dept. of Radiology, Sanggye Paik Hospital, Inje University College of Medicine, Seoul (Korea, Republic of); Kim, Hyun Jung [Dept. of Pathology, Sanggye Paik Hospital, Inje University College of Medicine, Seoul (Korea, Republic of)

    2012-02-15

    Renal cell carcinoma (RCC) is often concomitant with distant metastasis, and these metastases are the first sign of an otherwise occult primary. Whereas metastasis of RCC to the head and neck has been reported, metastasis to the masseter muscle, which is composed of skeletal muscle, is quite rare. We now report the case of a 66-year-old man who had a past history of pulmonary tuberculosis, with RCC metastasis of a well-defined intensely enhancing hypervascular mass in the masseter muscle as the initial presentation. We present the imaging findings of this case and a literature review about radiologic differential diagnosis of intramasseteric masses.

  8. Type VI collagen turnover-related peptides—novel serological biomarkers of muscle mass and anabolic response to loading in young men

    Nedergaard, Anders; Sun, Shu; Karsdal, Morten A

    2013-01-01

    Immobilization-induced loss of muscle mass is a complex phenomenon with several parallels to sarcopenic and cachectic muscle loss. Muscle is a large organ with a protein turnover that is orders of magnitude larger than most other tissues. Thus, we hypothesize that muscle loss and regain is reflec...

  9. The role of fat mass and skeletal muscle mass in knee osteoarthritis is different for men and women: the NEO study

    Visser, A.W. de; Mutsert, R. de; Loef, M.; Cessie, S. le; Heijer, M. den; Bloem, J.L.; Reijnierse, M.; Rosendaal, F.R.; Kloppenburg, M.; Assendelft, W.J.J.; Smit, J.W.A.; et al.,

    2014-01-01

    OBJECTIVE: To investigate if the amount of fat mass (FM) or skeletal muscle mass (SMM) is more strongly associated with knee osteoarthritis (OA), in both men and women. METHODS: The Netherlands Epidemiology of Obesity (NEO) study is a population-based cohort aged 45-65 years, including 5313

  10. Effects of menopause and high-intensity training on insulin sensitivity and muscle metabolism.

    Mandrup, Camilla M; Egelund, Jon; Nyberg, Michael; Enevoldsen, Lotte Hahn; Kjær, Andreas; Clemmensen, Andreas E; Christensen, Anders Nymark; Suetta, Charlotte; Frikke-Schmidt, Ruth; Steenberg, Dorte Enggaard; Wojtaszewski, Jørgen F P; Hellsten, Ylva; Stallknecht, Bente M

    2018-02-01

    To investigate peripheral insulin sensitivity and skeletal muscle glucose metabolism in premenopausal and postmenopausal women, and evaluate whether exercise training benefits are maintained after menopause. Sedentary, healthy, normal-weight, late premenopausal (n = 21), and early postmenopausal (n = 20) women were included in a 3-month high-intensity exercise training intervention. Body composition was assessed by magnetic resonance imaging and dual-energy x-ray absorptiometry, whole body glucose disposal rate (GDR) by hyperinsulinemic euglycemic clamp (40 mU/m/min), and femoral muscle glucose uptake by positron emission tomography/computed tomography, using the glucose analog fluorodeoxyglucose, expressed as estimated metabolic rate (eMR). Insulin signaling was investigated in muscle biopsies. Age difference between groups was 4.5 years, and no difference was observed in body composition. Training increased lean body mass (estimate [95% confidence interval] 0.5 [0.2-0.9] kg, P training (eMR vastus lateralis muscle: 27.8 [19.6-36.0] μmol/min/kg, P training-induced increases in insulin sensitivity included increased expression of hexokinase (19.2 [5.0-24.7] AU, P = 0.02) and glycogen synthase (32.4 [15.0-49.8] AU, P high-intensity exercise training.

  11. Aluminum nanocantilevers for high sensitivity mass sensors

    Davis, Zachary James; Boisen, Anja

    2005-01-01

    We have fabricated Al nanocantilevers using a simple, one mask contact UV lithography technique with lateral and vertical dimensions under 500 and 100 nm, respectively. These devices are demonstrated as highly sensitive mass sensors by measuring their dynamic properties. Furthermore, it is shown ...

  12. Relative muscle mass and the risk of incident type 2 diabetes: A cohort study.

    Sungwoo Hong

    Full Text Available The association between relative muscle mass (RMM and incidence of type 2 diabetes (T2DM is largely unknown. We examined whether RMM predicted development of T2DM in an apparently young healthy population.This cohort study was comprised of 113,913 men and 89,854 women, free of T2DM at baseline, who underwent a health checkup examination and were followed-up annually or biennially for an average of 2.9 years. We used skeletal muscle mass index (SMI as an indicator of RMM. SMI (% [total skeletal muscle mass (kg/body weight (kg×100] was estimated using a bioelectrical impedance analyzer. The study outcome was incident T2DM, defined as fasting serum glucose ≥126 mg/dL, HbA1C ≥6.5%, or use of medication for T2DM.During 589,098.8 person-years of follow-up, 4,264 individuals developed T2DM (incidence rate, 7.2 per 1000 person-years. Median age (range at baseline was 39.1 years (18.1-87.1. RMM was negatively associated with incidence of T2DM in a dose-response manner. The multivariate-adjusted hazard ratios (95% CIs for incident T2DM comparing quartiles 3, 2 and 1 of RMM to the highest quartile were 1.32 (1.14-1.52, 1.63 (1.42-1.86, and 2.21 (1.94-2.51, respectively, for males and 1.18 (0.88-1.58, 1.46 (1.11-1.91, and 1.96 (01.51-2.53 for females (P for trend <0.001; 0.011. This association was stronger in younger or premenopausal subjects.RMM was negatively associated with development of T2DM in a large sample of young and middle-aged Korean adults. Further research is required to determine whether preservation of muscle mass through intervention affects the risk of T2DM.

  13. Leg muscle mass and composition in relation to lower extremity performance in men and women aged 70 to 79 : the health, aging and body composition study

    Visser, Marjolein; Kritchevsky, Stephen B; Goodpaster, Bret H; Newman, Anne B; Nevitt, Michael; Stamm, Elizabeth; Harris, Tamara B

    OBJECTIVES: The loss of muscle mass with aging, or sarcopenia, is hypothesized to be associated with the deterioration of physical function. Our aim was to determine whether low leg muscle mass and greater fat infiltration in the muscle were associated with poor lower extremity performance (LEP).

  14. The effect of individualized nutritional counseling on muscle mass and treatment outcome in patients with metastatic colorectal cancer undergoing chemotherapy: a randomized controlled trial protocol

    van der Werf, Anne; Blauwhoff-Buskermolen, Susanne; Langius, Jacqueline A. E.; Berkhof, Johannes; Verheul, Henk M. W.; de van der Schueren, Marian A. E.

    2015-01-01

    A low muscle mass is prevalent in patients with metastatic colorectal cancer (mCRC) and has been associated with poor treatment outcome. Chemotherapeutic treatment has an additional unfavorable effect on muscle mass. Sufficient protein intake and physical activity are known to induce muscle protein

  15. Automatic Calibration of High Density Electric Muscle Stimulation

    Knibbe, Jarrod; Strohmeier, Paul; Boring, Sebastian

    2017-01-01

    . (2) EMS requires time consuming, expert calibration -- confining these interaction techniques to the lab. EMS arrays have been shown to increase stimulation resolution, but as calibration complexity increases exponentially as more electrodes are used, we require heuristics or automated procedures......Electric muscle stimulation (EMS) can enable mobile force feedback, support pedestrian navigation, or confer object affordances. To date, however, EMS is limited by two interlinked problems. (1) EMS is low resolution -- achieving only coarse movements and constraining opportunities for exploration...... for successful calibration. We explore the feasibility of using electromyography (EMG) to auto-calibrate high density EMS arrays. We determine regions of muscle activity during human-performed gestures, to inform stimulation patterns for EMS-performed gestures. We report on a study which shows that auto...

  16. Visceral obesity, fat mass/muscle mass ratio and atherogenic dyslipidemia: cross-sectional study. Riobamba, Ecuador

    Tomas Marcelo Nicolalde Cifuentes

    2015-10-01

    Full Text Available Introduction: The distribution and composition of fat mass is associated with different metabolic risks. The predominance of brown visceral fat is associated with risk factors for cardiovascular disease (CVD, such as: high triglycerides and apolipoprotein B, increased LDL cholesterol, ratio triglycerides/low HDL cholesterol elevated (atherogenic dyslipidemia indicator, insulin resistance, hyperinsulinemia and cardiovascular risk (CVR. Sarcopenia and obesity may act synergistically in functional and metabolic disorders. The aim of this study was to determine the relationship between visceral obesity, fat mass/muscular mass ratio and atherogenic dyslipidemia in adult individuals in order to determine the association pattern between these variables and set strategies for focused attention.Material and Methods: In a sample of 307 subjects of both sexes (21-71 years there was measured atherogenic dyslipidemia as the ratio of triglyceride/HDL cholesterol, visceral obesity measured by bio impedance as the relative score of visceral fat, and the ratio fat mass/lean mass.Results: A cluster analysis was performed to establish the structure of association between these variables with different risk groups. Three groups were identified: the first had visceral obesity with an average relative level of visceral fat of 13.6, the second group with an average of 8.9 and in the third group were placed individuals with the lowest visceral obesity score averaging 6.5. As for the fat mass/lean mas ratio the first two groups had a similar average of this index with a value of 1.56 and 1.69 respectively and the third group with the lowest average value of 1.3. Group 1 presented visceral obesity and impaired fat mass/lean mass ratio and had a high value of triglyceride/HDL ratio 4.1. Group 2 without visceral obesity and a deterioration in the relative fat mass/lean mass ratio had a triglyceride/HDL cholesterol of 3.6 and Group 3; not recorded visceral obesity or

  17. Baseline muscle mass is a poor predictor of functional overload-induced gain in the mouse model

    Audrius Kilikevicius

    2016-11-01

    Full Text Available Genetic background contributes substantially to individual variability in muscle mass. Muscle hypertrophy in response to resistance training can also vary extensively. However, it is less clear if muscle mass at baseline is predictive of the hypertrophic response.The aim of this study was to examine the effect of genetic background on variability in muscle mass at baseline and in the adaptive response of the mouse fast- and slow-twitch muscles to overload. Males of eight laboratory mouse strains: C57BL/6J (B6, n=17, BALB/cByJ (n=7, DBA/2J (D2, n=12, B6.A-(rs3676616-D10Utsw1/Kjn (B6.A, n=9, C57BL/6J-Chr10A/J/NaJ (B6.A10, n=8, BEH+/+ (n=11, BEH (n=12 and DUHi (n=12, were studied. Compensatory growth of soleus and plantaris muscles was triggered by a 4-week overload induced by synergist unilateral ablation. Muscle weight in the control leg (baseline varied from 5.2±07 mg soleus and 11.4±1.3 mg plantaris in D2 mice to 18.0±1.7 mg soleus in DUHi and 43.7±2.6 mg plantaris in BEH (p<0.001 for both muscles. In addition, soleus in the B6.A10 strain was ~40% larger (p<0.001 compared to the B6. Functional overload increased muscle weight, however, the extent of gain was strain-dependent for both soleus (p<0.01 and plantaris (p<0.02 even after accounting for the baseline differences. For the soleus muscle, the BEH strain emerged as the least responsive, with a 1.3-fold increase, compared to a 1.7-fold gain in the most responsive D2 strain, and there was no difference in the gain between the B6.A10 and B6 strains. The BEH strain appeared the least responsive in the gain of plantaris as well, 1.3-fold, compared to ~1.5-fold gain in the remaining strains. We conclude that variation in muscle mass at baseline is not a reliable predictor of that in the overload-induced gain. This suggests that a different set of genes influence variability in muscle mass acquired in the process of normal development, growth and maintenance, and in the process of adaptive

  18. Per meal dose and frequency of protein consumption is associated with lean mass and muscle performance.

    Loenneke, Jeremy P; Loprinzi, Paul D; Murphy, Caoileann H; Phillips, Stuart M

    2016-12-01

    It has been hypothesized that for older adults evenly distributing consumption of protein at 30-40 g per meal throughout the day may result in more favorable retention of lean mass and muscular strength. Such a thesis has not, to our knowledge, been tested outside of short-term studies or acute measures of muscle protein synthesis. To examine whether the number of times an individual consumed a minimum of 30 g of protein at a meal is associated with leg lean mass and knee extensor strength. Data from the 1999-2002 NHANES were used, with 1081 adults (50-85 y) constituting the analytic sample. A "multiple pass" 24-h dietary interview format was used to collect detailed information about the participants' dietary intake. Knee extensor strength was assessed objectively using the Kin Com MP dynamometer. Leg lean mass was estimated from whole-body dual-energy X-ray absorptiometry (DXA) scans. Participants with 1 vs. 0 (β adjusted  = 23.6, p = 0.002) and 2 vs. 0 (β adjusted  = 51.1, p = 0.001) meals of ≥30 g protein/meal had greater strength and leg lean mass (1 vs. 0, β adjusted  = 1160, p frequency with leg lean mass and strength plateaued at ∼45 g protein/meal for those consuming 2 vs. 0 meals above the evaluated protein/meal threshold. However, for those with only 1 meal at or above the evaluated threshold, the response plateaued at 30 g/meal. Leg lean mass mediated the relationship between protein frequency and strength, with the proportion of the total effect mediated being 64%. We found that more frequent consumption of meals containing between 30 and 45 g protein/meal produced the greatest association with leg lean mass and strength. Thus, the consumption of 1-2 daily meals with protein content from 30 to 45 g may be an important strategy for increasing and/or maintaining lean body mass and muscle strength with aging. Copyright © 2016 Elsevier Ltd and European Society for Clinical Nutrition and Metabolism. All rights reserved.

  19. Impact of Skeletal Muscle Mass Index, Intramuscular Adipose Tissue Content, and Visceral to Subcutaneous Adipose Tissue Area Ratio on Early Mortality of Living Donor Liver Transplantation.

    Hamaguchi, Yuhei; Kaido, Toshimi; Okumura, Shinya; Kobayashi, Atsushi; Shirai, Hisaya; Yagi, Shintaro; Kamo, Naoko; Okajima, Hideaki; Uemoto, Shinji

    2017-03-01

    Skeletal muscle depletion has been shown to be an independent risk factor for poor survival in various diseases. However, in surgery, the significance of other body components including visceral and subcutaneous adipose tissue remains unclear. This retrospective study included 250 adult patients undergoing living donor liver transplantation (LDLT) between January 2008 and April 2015. Using preoperative plain computed tomography imaging at the third lumbar vertebra level, skeletal muscle mass, muscle quality, and visceral adiposity were evaluated by the skeletal muscle mass index (SMI), intramuscular adipose tissue content (IMAC), and visceral to subcutaneous adipose tissue area ratio (VSR), respectively. The cutoff values of these parameters were determined for men and women separately using the data of 657 healthy donors for LDLT between 2005 and 2016. Impact of these parameters on outcomes after LDLT was analyzed. VSR was significantly correlated with patient age (P = 0.041), neutrophil-lymphocyte ratio (P mass index (P normal group. On multivariate analysis, low SMI (hazard ratio [HR], 2.367, P = 0.002), high IMAC (HR, 2.096, P = 0.004), and high VSR (HR, 2.213, P = 0.003) were identified as independent risk factors for death after LDLT. Preoperative visceral adiposity, as well as low muscularity, was closely involved with posttransplant mortality.

  20. Resistance Exercise Impacts Lean Muscle Mass in Women with Polycystic Ovary Syndrome.

    Kogure, Gislaine Satyko; Miranda-Furtado, Cristiana Libardi; Silva, Rafael Costa; Melo, Anderson Sanches; Ferriani, Rui Alberto; De Sá, Marcos Felipe Silva; Dos Reis, Rosana Maria

    2016-04-01

    This study investigated the effects of progressive resistance training (PRT) on lean muscle mass (LMM) in women with or without polycystic ovary syndrome (PCOS) and its effects on metabolic factors and concentrations of related steroid hormones. This was a nonrandomized, therapeutic, open, single-arm study. All in all, 45 sedentary women with PCOS and 52 without (non-PCOS), 18-37 yr of age, with body mass indexes (BMI) of 18-39.9 kg·m(-2) of all races and social status, performed PRT three times a week for 4 months. Before and after PRT, the concentrations of hormones and metabolic factors and waist circumference were measured. LMM and total body fat percentage were determined using dual-energy x-ray absorptiometry. Clinical characteristics, LMM, and fasting glucose were adjusted for confounding covariables and compared using general linear mixed models. Each patient's menstrual history was taken before study enrollment and after PRT. PRT resulted in reduced plasma testosterone and fasting glucose levels. After PRT, the androstenedione concentration increased and the sex hormone-binding globulin concentration decreased in women with PCOS. The waist circumference was reduced (P lean mass (LM)/height2, increased in women with PCOS (P = 0.04). Women with PCOS showed increased muscle mass indexes of appendicular LM/height2 (P = 0.03) and LM/height2 (P women with PCOS (P = 0.01) at the baseline and after PRT. To our knowledge, this is the first report to show that resistance exercise alone can improve hyperandrogenism, reproductive function, and body composition by decreasing visceral fat and increasing LMM, but it has no metabolic impact on women with PCOS.

  1. Is increase in bone mineral content caused by increase in skeletal muscle mass/strength in adult patients with GH-treated GH deficiency? A systematic literature analysis

    Klefter, O.; Feldt-Rasmussen, U.

    2009-01-01

    to a muscle modulating effect, and if treatment with GH would primarily increase muscle mass and strength with a secondary increase in BMD/BMC, thus supporting the present physiological concept that mass and strength of bones are mainly determined by dynamic loads from the skeletal muscles. METHOD: We...... performed a systematic literature analysis, including 51 clinical trials published between 1996 and 2008, which had studied the development in muscle mass, muscle strength, BMD, and/or BMC in GH-treated adult GHD patients. RESULTS: GH therapy had an anabolic effect on skeletal muscle. The largest increase...... in muscle mass occurred during the first 12 months of therapy. Most trials measuring BMD/BMC reported significant increases from baseline values. The significant increases in BMD/BMC occurred after 12-18 months of treatment, i.e. usually later than the increases in muscle parameters. Only seven trials...

  2. Is increase in bone mineral content caused by increase in skeletal muscle mass/strength in adult patients with GH-treated GH deficiency?

    Klefter, Oliver; Feldt-Rasmussen, Ulla

    2009-01-01

    to a muscle modulating effect, and if treatment with GH would primarily increase muscle mass and strength with a secondary increase in BMD/BMC, thus supporting the present physiological concept that mass and strength of bones are mainly determined by dynamic loads from the skeletal muscles. METHOD: We...... performed a systematic literature analysis, including 51 clinical trials published between 1996 and 2008, which had studied the development in muscle mass, muscle strength, BMD, and/or BMC in GH-treated adult GHD patients. RESULTS: GH therapy had an anabolic effect on skeletal muscle. The largest increase...... in muscle mass occurred during the first 12 months of therapy. Most trials measuring BMD/BMC reported significant increases from baseline values. The significant increases in BMD/BMC occurred after 12-18 months of treatment, i.e. usually later than the increases in muscle parameters. Only seven trials...

  3. A dietary supplementation with leucine and antioxidants is capable to accelerate muscle mass recovery after immobilization in adult rats.

    Isabelle Savary-Auzeloux

    Full Text Available Prolonged inactivity induces muscle loss due to an activation of proteolysis and decreased protein synthesis; the latter is also involved in the recovery of muscle mass. The aim of the present work was to explore the evolution of muscle mass and protein metabolism during immobilization and recovery and assess the effect of a nutritional strategy for counteracting muscle loss and facilitating recovery. Adult rats (6-8 months were subjected to unilateral hindlimb casting for 8 days (I0-I8 and then permitted to recover for 10 to 40 days (R10-R40. They were fed a Control or Experimental diet supplemented with antioxidants/polyphenols (AOX (I0 to I8, AOX and leucine (AOX + LEU (I8 to R15 and LEU alone (R15 to R40. Muscle mass, absolute protein synthesis rate and proteasome activities were measured in gastrocnemius muscle in casted and non-casted legs in post prandial (PP and post absorptive (PA states at each time point. Immobilized gastrocnemius protein content was similarly reduced (-37% in both diets compared to the non-casted leg. Muscle mass recovery was accelerated by the AOX and LEU supplementation (+6% AOX+LEU vs. Control, P<0.05 at R40 due to a higher protein synthesis both in PA and PP states (+23% and 31% respectively, Experimental vs. Control diets, P<0.05, R40 without difference in trypsin- and chymotrypsin-like activities between diets. Thus, this nutritional supplementation accelerated the recovery of muscle mass via a stimulation of protein synthesis throughout the entire day (in the PP and PA states and could be a promising strategy to be tested during recovery from bed rest in humans.

  4. Relationship between lifting performance and skeletal muscle mass in elite powerlifters.

    Ye, X; Loenneke, J P; Fahs, C A; Rossow, L M; Thiebaud, R S; Kim, D; Bemben, M G; Abe, T

    2013-08-01

    Aim of the study was to examine the relationship between whole body skeletal muscle mass (SMM) and powerlifting performance in elite powerlifters. Twenty elite male powerlifters, including 4 world champions, volunteered. Muscle thickness (MTH) and subcutaneous fat thickness (FTH) were measured by ultrasound at 9 sites on the anterior and posterior aspects of the body. FTH was used to estimate body fat and fat-free mass and SMM was estimated from ultrasound-derived prediction equations. Best lifting performance in the squat (SQ), bench press (BP), and dead lift (DL) was recorded from competition performance. Significant strong correlations (Pwide range of weight classes (56kg-145kg) and there were no significant correlation between the SMM and those performances (r=0.21 for SQ and r=0.12 for BP). However, the DL/SMM ratio was negatively correlated to DL performance (r=-0.47, P<0.05). SMM is a good predictor of powerlifting performance throughout all weight classes.

  5. Low appendicular skeletal muscle mass (ASM) with limited mobility and poor health outcomes in middle-aged African Americans.

    Malmstrom, Theodore K; Miller, Douglas K; Herning, Margaret M; Morley, John E

    2013-09-01

    Recent efforts to provide a consensus definition propose that sarcopenia be considered a clinical syndrome associated with the loss of both skeletal muscle mass and muscle function that occurs with aging. Validation of sarcopenia definitions that include both low muscle mass and poor muscle function is needed. In the population-based African American Health (AAH) study (N = 998 at baseline/wave 1), muscle mass and mobility were evaluated in a clinical testing center in a subsample of N = 319 persons (ages 52-68) at wave 4 (2004). Muscle mass was measured using dual energy x-ray absorptiometry and mobility by a 6-min walk test and 4-m gait walk test. Height corrected appendicular skeletal mass (ASM; 9.0 ± 1.5 in n = 124 males, 8.3 ± 2.2 in n = 195 females) was computed as total lean muscle mass in arms and legs (kilograms) divided by the square of height (meters). Cross-sectional and longitudinal (6-year) associations of low ASM (bottom 25 % AAH sample; ASM with limited mobility (4-m gait walk ≤1 m/s or 6-min walk ASM with limited mobility was associated with IADL difficulties (p = .008) and frailty (p = .040) but not with ADL difficulties or falls in cross-sectional analyses; and with ADL difficulties (p = .022), IADL difficulties (p = .006), frailty (p = .039), and mortality (p = .003) but not with falls in longitudinal analyses adjusted for age and gender. Low ASM alone was marginally associated with mortality (p = .085) but not with other outcomes in cross-sectional or longitudinal analyses. Low ASM with limited mobility is associated with poor health outcomes among late middle-aged African Americans.

  6. An ATLAS high mass dijet event

    ATLAS, Experiment

    2014-01-01

    A high mass dijet event: two high-pT jets with invariant mass 2.8 TeV. A track pT cut of 2.5 GeV has been applied for the display. 1st jet (ordered by pT): pT = 310 GeV, y = -2.0, φ = -0.2 2nd jet: pT = 280 GeV, y = 2.5, φ = 2.9 3rd jet: pT = 14 GeV, y = -0.9, φ = -1.0 Jet momenta are calibrated according to the "EM+JES" scheme. Event collected on 5 August 2010.

  7. Vector Boson Scattering at High Mass

    The ATLAS collaboration

    2009-01-01

    In the absence of a light Higgs boson, the mechanism of electroweak symmetry breaking will be best studied in processes of vector boson scattering at high mass. Various models predict resonances in this channel. Here, we investigate $WW $scalar and vector resonances, $WZ$ vector resonances and a $ZZ$ scalar resonance over a range of diboson centre-of-mass energies. Particular attention is paid to the application of forward jet tagging and to the reconstruction of dijet pairs with low opening angle resulting from the decay of highly boosted vector bosons. The performances of different jet algorithms are compared. We find that resonances in vector boson scattering can be discovered with a few tens of inverse femtobarns of integrated luminosity.

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

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

    2004-01-01

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

  9. Relation between body mass index percentile and muscle strength and endurance

    Noha Abdel Kader Abdel Kader Hasan

    2016-10-01

    Conclusion: The study shows that the BMI of children had a positive correlation with the muscle strength of quadriceps, triceps, and abdominal muscles while a negative correlation with the endurance time of these muscles.

  10. The total body mass of fatty acid ethyl esters in skeletal muscles following ethanol exposure greatly exceeds that found in the liver and the heart.

    Salem, Raneem O; Laposata, Michael; Rajendram, Rajkumar; Cluette-Brown, Joanne E; Preedy, Victor R

    2006-01-01

    Skeletal muscle appears to be susceptible to chronic and acute excess alcohol intake, giving rise to alcoholic myopathy, a common disease among alcoholics. Fatty acid ethyl esters (FAEE), non-oxidative metabolites of ethanol, have been shown to be toxic to cells in vitro and in vivo. We hypothesized that accumulation of FAEE in skeletal muscle could contribute to the development of alcoholic myopathy. Male wistar rats were treated either with 75 mmol ethanol/kg body weight or saline, in the fed state or starved for 1 or 2 days before administration. Rats were thus divided into the following groups: fed-saline (n = 8); fed-ethanol (n = 8); starved 1 day, saline (n = 8); starved 1 day, ethanol (n = 9); starved 2 days, saline (n = 7); and starved 2 days, ethanol (n = 8). At the end of the incubation, skeletal muscles (abdominal and gastrocnemius), liver, and heart were isolated and processed for FAEE isolation and analysis by gas chromatography-mass spectrometry (GC-MS). Total mass of FAEE in the muscles was much greater than that found in the liver and the heart. In general, the animals that were fasted for 1 day and received ethanol had the highest FAEE levels among the three groups of animals. The major ethyl ester species in all cases were ethyl 16:0, ethyl 18:0, ethyl 18:1 n-9, and ethyl 18:2 n-6. Ethyl 20:4 n-6 and ethyl 22:6 n-3 were also present, except in the fasted 1-day group, where ethyl 22:6 disappeared, though it reappeared in the fasted 2-day group. These findings demonstrate that skeletal muscles contain high levels of FAEE that are synthesized in the body after ethanol exposure. The concentration of FAEE in skeletal muscle in this study was very similar to FAEE concentration in the liver. This differs from previous studies suggesting a low concentration of skeletal muscle FAEE with ethanol exposure.

  11. Prognostic significance of low skeletal muscle mass compared with protein-energy malnutrition in liver cirrhosis.

    Nishikawa, Hiroki; Enomoto, Hirayuki; Ishii, Akio; Iwata, Yoshinori; Miyamoto, Yuho; Ishii, Noriko; Yuri, Yukihisa; Takata, Ryo; Hasegawa, Kunihiro; Nakano, Chikage; Nishimura, Takashi; Yoh, Kazunori; Aizawa, Nobuhiro; Sakai, Yoshiyuki; Ikeda, Naoto; Takashima, Tomoyuki; Iijima, Hiroko; Nishiguchi, Shuhei

    2017-09-01

    To investigate the impact of low skeletal muscle mass (LSMM) on survival as compared with protein-energy malnutrition (PEM) in patients with liver cirrhosis (LC). A total of 206 individuals with LC were analyzed. We retrospectively examined the impact of LSMM, as defined by psoas muscle mass at the third lumber on computed tomography, on survival as compared with PEM. In terms of comparison of the effects of LSMM and PEM on survival, we used time-dependent receiver operating characteristics (ROC) analysis. Our study cohort included 115 men and 91 women with a median age of 67 years. There were 140 patients with Child-Pugh A, 62 with Child-Pugh B, and 4 with Child-Pugh C. A total of 117 patients (56.8%) had LSMM and 52 patients (25.2%) had PEM. The proportion of PEM in patients with LSMM (31.62%, 37/117) was significantly higher than in patients without LSMM (16.85%, 15/89) (P = 0.0229). In the multivariate analysis for the entire cohort, the presence of hepatocellular carcinoma, lower body mass index, presence of LSMM, lower triglyceride value, poorer renal function, and higher des-γ-carboxy prothrombin value were found to be significant adverse predictors linked to overall survival, while presence of PEM tended to be significant. In the time-dependent ROC analysis, all area under the ROCs for survival in LSMM at each time point were higher than those in PEM except for Child-Pugh B patients. In this comparison of LSMM and PEM on clinical outcomes in LC patients, it was shown that LSMM may have stronger prognostic impact than PEM. © 2016 The Japan Society of Hepatology.

  12. The Effect of a 12-Week Omega-3 Supplementation on Body Composition, Muscle Strength and Physical Performance in Elderly Individuals with Decreased Muscle Mass

    Roma Krzymińska-Siemaszko

    2015-08-01

    Full Text Available The aim of the study was to assess the effect of a polyunsaturated omega-3 fatty acids (PUFA supplementation on the parameters of body composition, muscle strength and physical performance in elderly people with decreased muscle mass (DMM. Fifty three elderly people with an ALM index (the ratio of appendicular lean mass to squared height either below (−2SD: low muscle mass-LMM or between (−1SD and −2SD: the risk of LMM-rLMM the ALM index for the young Polish reference population were randomly assigned to PUFA-treated groups (LMM-PUFA, rLMM-PUFA or control groups (LMM-control, rLMM-control. PUFA-treated groups received capsules containing 1.3 g of PUFA and 10 mg of vitamin E, while the control groups received 11 mg of vitamin E daily for 12 weeks. Body composition (BIA analysis, muscle strength (hand grip measured with dynamometer and physical performance (Timed Up and Go test-TUG were assessed before and after supplementation. No statistically significant differences were observed either in muscle mass or in the hand grip and TUG in any group. The post-pre difference (mean ± SD in ALM index was as follows (kg/m2: LMM-PUFA: 0.00 ± 0.30, rLMM-PUFA: 0.00 ± 0.22, LMM-control: 0.03 ± 0.36, rLMM-control: –0.03 ± 0.20. In our study, a 12 week supplementation of PUFA did not affect the evaluated parameters in elderly individuals with DMM.

  13. SPIRAL2/DESIR high resolution mass separator

    Kurtukian-Nieto, T., E-mail: kurtukia@cenbg.in2p3.fr [Centre d’Études Nucléaires de Bordeaux Gradignan, Université Bordeaux 1-CNRS/IN2P3, BP 120, F-33175 Gradignan Cedex (France); Baartman, R. [TRIUMF, 4004 Wesbrook Mall, Vancouver B.C., V6T 2A3 (Canada); Blank, B.; Chiron, T. [Centre d’Études Nucléaires de Bordeaux Gradignan, Université Bordeaux 1-CNRS/IN2P3, BP 120, F-33175 Gradignan Cedex (France); Davids, C. [Physics Division, Argonne National Laboratory, Argonne, IL 60439 (United States); Delalee, F. [Centre d’Études Nucléaires de Bordeaux Gradignan, Université Bordeaux 1-CNRS/IN2P3, BP 120, F-33175 Gradignan Cedex (France); Duval, M. [GANIL, CEA/DSM-CNRS/IN2P3, Bd Henri Becquerel, BP 55027, F-14076 Caen Cedex 5 (France); El Abbeir, S.; Fournier, A. [Centre d’Études Nucléaires de Bordeaux Gradignan, Université Bordeaux 1-CNRS/IN2P3, BP 120, F-33175 Gradignan Cedex (France); Lunney, D. [CSNSM-IN2P3-CNRS, Université de Paris Sud, F-91405 Orsay (France); Méot, F. [BNL, Upton, Long Island, New York (United States); Serani, L. [Centre d’Études Nucléaires de Bordeaux Gradignan, Université Bordeaux 1-CNRS/IN2P3, BP 120, F-33175 Gradignan Cedex (France); Stodel, M.-H.; Varenne, F. [GANIL, CEA/DSM-CNRS/IN2P3, Bd Henri Becquerel, BP 55027, F-14076 Caen Cedex 5 (France); and others

    2013-12-15

    DESIR is the low-energy part of the SPIRAL2 ISOL facility under construction at GANIL. DESIR includes a high-resolution mass separator (HRS) with a designed resolving power m/Δm of 31,000 for a 1 π-mm-mrad beam emittance, obtained using a high-intensity beam cooling device. The proposed design consists of two 90-degree magnetic dipoles, complemented by electrostatic quadrupoles, sextupoles, and a multipole, arranged in a symmetric configuration to minimize aberrations. A detailed description of the design and results of extensive simulations are given.

  14. Effects of progressive strength training on muscle mass in type 2 diabetes mellitus patients determined by computed tomography

    Cauza, E.; Strehblow, C.; Hanusch-Enserer, U.; Fasching, P.; Metz-Schimmerl, S.; Strasser, B.; Kostner, K.; Dunstan, D.; Haber, P.

    2009-01-01

    To examine the effect of a 4-month progressive strength training program on muscle and fat mass assessed by computed tomography (CT) in type 2 diabetes mellitus (T2DM) patients, and to assess the relationships of changes in muscle cross-section area (CSA) with glycaemic control. Twenty adults (mean age ± SE: 56.4 ± 0.9 a) with T2DM participated in a supervised strength training program for 4 months 3 days/week. Muscle and fat areas of the quadriceps muscle were estimated by CT volumetry before and immediately after the training. Glycaemic (HbA1c) and anthropometric (BMI, skinfolds) measurements were assessed at 0 and 4 months, respectively. After strength training, muscle strength increased significantly in all measured muscle groups. Quadriceps size (CSA of the muscle) was increased by 2.4 % (from 7.99 ± 0.3 cm 3 to 8.18 ± 0.3 cm 3 , p = 0.003) for the right extremity, 3.9 % (from 8.1 ± 0.4 cm 3 to 8.41 ± 0.5 cm 3 , p = 0.04) for the left side. Fat tissue CSA reduced from 0.66 ± 0.1 cm 3 to 0.56 ± 0.12 cm 3 for the right leg (15.3 % reduction) and from 0.58 ± 0.12 cm 3 to 0.37 ± 0.13 cm 3 for the left leg (35.8 % reduction), resulting in a mean fat CSA reduction of 24.8 %. Fat mass assessed by skin folds was significantly reduced and lean body mass was significantly increased. The change in muscle CSA was not correlated with the changes in HbA1c or muscle strength. Strength training significantly improves both muscle mass and the muscle to fat ratio in T2DM. However, changes in muscle observed with computed tomography were not related to changes observed in HbA1c with training. (author) [de

  15. Usefulness of circuit training at home for improving bone mass and muscle mass while losing fat mass in undergraduate female students.

    Takahata, Yoko

    2018-05-09

    The purpose of this study was to determine whether or not circuit training at home affects the calcaneus quantitative ultrasound status as well as other indices of body composition among undergraduate female students. Forty-one adolescents were recruited (18.5 ± 0.6 years old). The stiffness index of the calcaneus, broadband ultrasound attenuation of the calcaneus, speed of sound of the calcaneus, and body frame index. This was a three-month intervention study, so the measurements were conducted at baseline, 2 months later, and 3 months later while the subjects underwent circuit training at home. The subjects were divided into two groups: namely, the exercising group and non-exercising group. In the exercising group, broadband ultrasound attenuation of the calcaneus was higher 2 months later (p = 0.033) as well as 3 months later (p = 0.036), and the speed of sound of the calcaneus was higher 3 months later (p = 0.018). In addition, the muscle mass was strongly positively correlated with the calcaneus QUS-SOS (p = 0.004), while the body fat percentage was a strongly negatively correlated with the calcaneus QUS-BUA (p = 0.043). In the non-exercising group, the stiffness index of the calcaneus was higher 2 months later (p = 0.002) as well as 3 months later (p = 0.002). Furthermore, the body percentage was strongly positively correlated with the calcaneus QUS-SI (p = 0.009). These findings suggest that the calcaneus quantitative ultrasound status and muscle mass while losing fat mass may be improved by means of a simple exercise regimen within a short period among undergraduate female students.

  16. Age-Associated Loss of OPA1 in Muscle Impacts Muscle Mass, Metabolic Homeostasis, Systemic Inflammation, and Epithelial Senescence.

    Tezze, Caterina; Romanello, Vanina; Desbats, Maria Andrea; Fadini, Gian Paolo; Albiero, Mattia; Favaro, Giulia; Ciciliot, Stefano; Soriano, Maria Eugenia; Morbidoni, Valeria; Cerqua, Cristina; Loefler, Stefan; Kern, Helmut; Franceschi, Claudio; Salvioli, Stefano; Conte, Maria; Blaauw, Bert; Zampieri, Sandra; Salviati, Leonardo; Scorrano, Luca; Sandri, Marco

    2017-06-06

    Mitochondrial dysfunction occurs during aging, but its impact on tissue senescence is unknown. Here, we find that sedentary but not active humans display an age-related decline in the mitochondrial protein, optic atrophy 1 (OPA1), that is associated with muscle loss. In adult mice, acute, muscle-specific deletion of Opa1 induces a precocious senescence phenotype and premature death. Conditional and inducible Opa1 deletion alters mitochondrial morphology and function but not DNA content. Mechanistically, the ablation of Opa1 leads to ER stress, which signals via the unfolded protein response (UPR) and FoxOs, inducing a catabolic program of muscle loss and systemic aging. Pharmacological inhibition of ER stress or muscle-specific deletion of FGF21 compensates for the loss of Opa1, restoring a normal metabolic state and preventing muscle atrophy and premature death. Thus, mitochondrial dysfunction in the muscle can trigger a cascade of signaling initiated at the ER that systemically affects general metabolism and aging. Copyright © 2017 The Author(s). Published by Elsevier Inc. All rights reserved.

  17. Ratio of muscle mass to fat mass assessed by bioelectrical impedance analysis is significantly correlated with liver fat accumulation in patients with type 2 diabetes mellitus.

    Kurinami, Noboru; Sugiyama, Seigo; Morita, Ayami; Yoshida, Akira; Hieshima, Kunio; Miyamoto, Fumio; Kajiwara, Keizo; Jinnouch, Katsunori; Jinnouchi, Tomio; Jinnouchi, Hideaki

    2018-05-01

    Obesity and ectopic fat accumulation are important conditions of type 2 diabetes mellitus (T2DM). Our aim was to determine whether bioelectrical impedance body composition analysis combined with blood test results could estimate liver ectopic fat accumulation in patients with treatment-naïve T2DM. Subjects were 119 untreated T2DM patients. Computed tomography scans were performed to calculate the liver to spleen attenuation ratio (L/S ratio) as a measure of liver fat accumulation, with excess liver fat accumulation defined as an L/S ratio analysis using InBody770. The Nagelkerke R 2 test showed that the muscle mass/fat mass ratio (muscle/fat ratio) was the most suitable variable among anthropometric factors and body component indexes for estimating liver fat accumulation. The muscle/fat ratio was significantly correlated with the L/S ratio (ρ = 0.4386, P analysis showed that the muscle/fat ratio (odds ratio 0.40, 95% confidence interval 0.22-0.73, P ratio 1.06, 95% confidence interval 1.02-1.10, P analysis, the cutoff value of the muscle/fat ratio for excess liver fat accumulation was 2.34. In patients with treatment-naïve T2DM, the muscle/fat ratio and ALT are useful for estimating the presence of excess liver fat accumulation in daily clinical practice. Copyright © 2018. Published by Elsevier B.V.

  18. Imaging mass spectrometry reveals fiber-specific distribution of acetylcarnitine and contraction-induced carnitine dynamics in rat skeletal muscles.

    Furuichi, Yasuro; Goto-Inoue, Naoko; Manabe, Yasuko; Setou, Mitsutoshi; Masuda, Kazumi; Fujii, Nobuharu L

    2014-10-01

    Carnitine is well recognized as a key regulator of long-chain fatty acyl group translocation into the mitochondria. In addition, carnitine, as acetylcarnitine, acts as an acceptor of excess acetyl-CoA, a potent inhibitor of pyruvate dehydrogenase. Here, we provide a new methodology for accurate quantification of acetylcarnitine content and determination of its localization in skeletal muscles. We used matrix-assisted laser desorption/ionization imaging mass spectrometry (MALDI-IMS) to visualize acetylcarnitine distribution in rat skeletal muscles. MALDI-IMS and immunohistochemistry of serial cross-sections showed that acetylcarnitine was enriched in the slow-type muscle fibers. The concentration of ATP was lower in muscle regions with abundant acetylcarnitine, suggesting a relationship between acetylcarnitine and metabolic activity. Using our novel method, we detected an increase in acetylcarnitine content after muscle contraction. Importantly, this increase was not detected using traditional biochemical assays of homogenized muscles. We also demonstrated that acetylation of carnitine during muscle contraction was concomitant with glycogen depletion. Our methodology would be useful for the quantification of acetylcarnitine and its contraction-induced kinetics in skeletal muscles. Copyright © 2014 Elsevier B.V. All rights reserved.

  19. Comparison between clinical significance of height-adjusted and weight-adjusted appendicular skeletal muscle mass.

    Furushima, Taishi; Miyachi, Motohiko; Iemitsu, Motoyuki; Murakami, Haruka; Kawano, Hiroshi; Gando, Yuko; Kawakami, Ryoko; Sanada, Kiyoshi

    2017-02-13

    This study aimed to compare relationships between height- or weight-adjusted appendicular skeletal muscle mass (ASM/Ht 2 or ASM/Wt) and risk factors for cardiometabolic diseases or osteoporosis in Japanese men and women. Subjects were healthy Japanese men (n = 583) and women (n = 1218). The study population included a young group (310 men and 357 women; age, 18-40 years) and a middle-aged and elderly group (273 men and 861 women; age, ≥41 years). ASM was measured by dual-energy X-ray absorptiometry. The reference values for class 1 and 2 sarcopenia in each sex were defined as values one and two standard deviations below the sex-specific means of the young group, respectively. The reference values for class 1 and 2 sarcopenia defined by ASM/Ht 2 were 7.77 and 6.89 kg/m 2 in men and 6.06 and 5.31 kg/m 2 in women, respectively. The reference values for ASM/Wt were 35.0 and 32.0% in men and 29.6 and 26.4% in women, respectively. In both men and women, ASM/Wt was negatively correlated with higher triglycerides (TG) and positively correlated with serum high-density lipoprotein cholesterol (HDL-C), but these associations were not found in height-adjusted ASM. In women, TG, systolic blood pressure, and diastolic blood pressure in sarcopenia defined by ASM/Wt were significantly higher than those in normal subjects, but these associations were not found in sarcopenia defined by ASM/Ht 2 . Whole-body and regional bone mineral density in sarcopenia defined by ASM/Ht 2 were significantly lower than those in normal subjects, but these associations were not found in sarcopenia defined by ASM/Wt. Weight-adjusted definition was able to identify cardiometabolic risk factors such as TG and HDL-C while height-adjusted definition could identify factors for osteoporosis.

  20. Polymorphisms of muscle genes are associated with bone mass and incident osteoporotic fractures in Caucasians

    Harsløf, Torben; Frost, M; Nielsen, T L

    2013-01-01

    The interaction between muscle and bone is complex. The aim of this study was to investigate if variations in the muscle genes myostatin (MSTN), its receptor (ACVR2B), myogenin (MYOG), and myoD1 (MYOD1) were associated with fracture risk, bone mineral density (BMD), bone mineral content (BMC......), and lean body mass. We analyzed two independent cohorts: the Danish Osteoporosis Prevention Study (DOPS), comprising 2,016 perimenopausal women treated with hormone therapy or not and followed for 10 years, and the Odense Androgen Study (OAS), a cross-sectional, population-based study on 783 men aged 20......-29 years. Nine tag SNPs in the four genes were investigated. In the DOPS, individuals homozygous for the variant allele of the MSTN SNP rs7570532 had an increased risk of any osteoporotic fracture, with an HR of 1.82 (95 % CI 1.15-2.90, p = 0.01), and of nonvertebral osteoporotic fracture, with an HR of 2...

  1. Testosterone therapy increased muscle mass and lipid oxidation in aging men

    Frederiksen, Louise; Højlund, Kurt; Hougaard, David M

    2011-01-01

    The indication for testosterone therapy in aging hypogonadal men without hypothalamic, pituitary, or testicular disease remains to be elucidated. The aim of this study was to investigate the effect of testosterone therapy on insulin sensitivity, substrate metabolism, body composition, and lipids...... lipid oxidation (b = 5.65 mg/min/m(2), p = 0.045) increased and basal glucose oxidation (b = -9.71 mg/min/m(2), p = 0.046) decreased in response to testosterone therapy even when corrected for changes in LBM. No significant changes in insulin-stimulated Rd was observed (b = -0.01mg/min/m(2), p = 0.......92). Testosterone therapy increased muscle mass and lipid oxidation in aging men with low normal bioavailable testosterone levels; however, our data did not support an effect of testosterone on whole-body insulin sensitivity using the euglycemic hyperinsulinemic clamp technique....

  2. Muscle quality, aerobic fitness and fat mass predict lower-extremity physical function in community-dwelling older adults.

    Misic, Mark M; Rosengren, Karl S; Woods, Jeffrey A; Evans, Ellen M

    2007-01-01

    Muscle mass, strength and fitness play a role in lower-extremity physical function (LEPF) in older adults; however, the relationships remain inadequately characterized. This study aimed to examine the relationships between leg mineral free lean mass (MFLM(LEG)), leg muscle quality (leg strength normalized for MFLM(LEG)), adiposity, aerobic fitness and LEPF in community-dwelling healthy elderly subjects. Fifty-five older adults (69.3 +/- 5.5 years, 36 females, 19 males) were assessed for leg strength using an isokinetic dynamometer, body composition by dual energy X-ray absorptiometry and aerobic fitness via a treadmill maximal oxygen consumption test. LEPF was assessed using computerized dynamic posturography and stair ascent/descent, a timed up-and-go task and a 7-meter walk with and without an obstacle. Muscle strength, muscle quality and aerobic fitness were similarly correlated with static LEPF tests (r range 0.27-0.40, p < 0.05); however, the strength of the independent predictors was not robust with explained variance ranging from 9 to 16%. Muscle quality was the strongest correlate of all dynamic LEPF tests (r range 0.54-0.65, p < 0.001). Using stepwise linear regression analysis, muscle quality was the strongest independent predictor of dynamic physical function explaining 29-42% of the variance (p < 0.001), whereas aerobic fitness or body fat mass explained 5-6% of the variance (p < 0.05) depending on performance measure. Muscle quality is the most important predictor, and aerobic fitness and fat mass are secondary predictors of LEPF in community-dwelling older adults. These findings support the importance of exercise, especially strength training, for optimal body composition, and maintenance of strength and physical function in older adults.

  3. The role of mTOR signaling in the regulation of protein synthesis and muscle mass during immobilization in mice

    You, Jae-Sung; Anderson, Garrett B.; Dooley, Matthew S.; Hornberger, Troy A.

    2015-01-01

    ABSTRACT The maintenance of skeletal muscle mass contributes substantially to health and to issues associated with the quality of life. It has been well recognized that skeletal muscle mass is regulated by mechanically induced changes in protein synthesis, and that signaling by mTOR is necessary for an increase in protein synthesis and the hypertrophy that occurs in response to increased mechanical loading. However, the role of mTOR signaling in the regulation of protein synthesis and muscle mass during decreased mechanical loading remains largely undefined. In order to define the role of mTOR signaling, we employed a mouse model of hindlimb immobilization along with pharmacological, mechanical and genetic means to modulate mTOR signaling. The results first showed that immobilization induced a decrease in the global rates of protein synthesis and muscle mass. Interestingly, immobilization also induced an increase in mTOR signaling, eIF4F complex formation and cap-dependent translation. Blocking mTOR signaling during immobilization with rapamycin not only impaired the increase in eIF4F complex formation, but also augmented the decreases in global protein synthesis and muscle mass. On the other hand, stimulating immobilized muscles with isometric contractions enhanced mTOR signaling and rescued the immobilization-induced decrease in global protein synthesis through a rapamycin-sensitive mechanism that was independent of ribosome biogenesis. Unexpectedly, the effects of isometric contractions were also independent of eIF4F complex formation. Similar to isometric contractions, overexpression of Rheb in immobilized muscles enhanced mTOR signaling, cap-dependent translation and global protein synthesis, and prevented the reduction in fiber size. Therefore, we conclude that the activation of mTOR signaling is both necessary and sufficient to alleviate the decreases in protein synthesis and muscle mass that occur during immobilization. Furthermore, these results indicate

  4. Dynamic proteome profiling of individual proteins in human skeletal muscle after a high-fat diet and resistance exercise.

    Camera, Donny M; Burniston, Jatin G; Pogson, Mark A; Smiles, William J; Hawley, John A

    2017-12-01

    It is generally accepted that muscle adaptation to resistance exercise (REX) training is underpinned by contraction-induced, increased rates of protein synthesis and dietary protein availability. By using dynamic proteome profiling (DPP), we investigated the contribution of both synthesis and breakdown to changes in abundance on a protein-by-protein basis in human skeletal muscle. Age-matched, overweight males consumed 9 d of a high-fat, low-carbohydrate diet during which time they either undertook 3 sessions of REX or performed no exercise. Precursor enrichment and the rate of incorporation of deuterium oxide into newly synthesized muscle proteins were determined by mass spectrometry. Ninety proteins were included in the DPP, with 28 proteins exhibiting significant responses to REX. The most common pattern of response was an increase in turnover, followed by an increase in abundance with no detectable increase in protein synthesis. Here, we provide novel evidence that demonstrates that the contribution of synthesis and breakdown to changes in protein abundance induced by REX differ on a protein-by-protein basis. We also highlight the importance of the degradation of individual muscle proteins after exercise in human skeletal muscle.-Camera, D. M., Burniston, J. G., Pogson, M. A., Smiles, W. J., Hawley, J. A. Dynamic proteome profiling of individual proteins in human skeletal muscle after a high-fat diet and resistance exercise. © FASEB.

  5. HOT HIGH-MASS ACCRETION DISK CANDIDATES

    Beuther, H.; Walsh, A. J.; Longmore, S. N.

    2009-01-01

    To better understand the physical properties of accretion disks in high-mass star formation, we present a study of a dozen high-mass accretion disk candidates observed at high spatial resolution with the Australia Telescope Compact Array (ATCA) in the high-excitation (4,4) and (5,5) lines of NH 3 . All of our originally selected sources were detected in both NH 3 transitions, directly associated with CH 3 OH Class II maser emission and implying that high-excitation NH 3 lines are good tracers of the dense gas components in hot-core-type targets. Only the one source that did not satisfy the initial selection criteria remained undetected. From the 11 mapped sources, six show clear signatures of rotation and/or infall motions. These signatures vary from velocity gradients perpendicular to the outflows, to infall signatures in absorption against ultracompact H II regions, to more spherical infall signatures in emission. Although our spatial resolution is ∼1000 AU, we do not find clear Keplerian signatures in any of the sources. Furthermore, we also do not find flattened structures. In contrast to this, in several of the sources with rotational signatures, the spatial structure is approximately spherical with sizes exceeding 10 4 AU, showing considerable clumpy sub-structure at even smaller scales. This implies that on average typical Keplerian accretion disks-if they exist as expected-should be confined to regions usually smaller than 1000 AU. It is likely that these disks are fed by the larger-scale rotating envelope structure we observe here. Furthermore, we do detect 1.25 cm continuum emission in most fields of view. While in some cases weak cm continuum emission is associated with our targets, more typically larger-scale H II regions are seen offset more than 10'' from our sources. While these H II regions are unlikely to be directly related to the target regions, this spatial association nevertheless additionally stresses that high-mass star formation rarely

  6. The Role of Muscle Mass, Muscle Quality, and Body Composition in Risk for the Metabolic Syndrome and Functional Decline in Older Adults: Topical Collection on Nutrition, Obesity, and Diabetes

    R.T. Mankowski (Robert T.); S.D. Anton (Stephen D.); M. Aubertin-Leheudre (Mylene)

    2015-01-01

    textabstractAbstract Age-related body composition changes include both loss of muscle mass (sarcopenia) and increase in fat mass, which jointly contribute to a decline in metabolic functions. Muscle quality is positively related to functional capacity and a lower risk for the development of the

  7. Contribution of Heritability and Epigenetic Factors to Skeletal Muscle Mass Variation in United Kingdom Twins.

    Livshits, Gregory; Gao, Fei; Malkin, Ida; Needhamsen, Maria; Xia, Yudong; Yuan, Wei; Bell, Christopher G; Ward, Kirsten; Liu, Yuan; Wang, Jun; Bell, Jordana T; Spector, Tim D

    2016-06-01

    Skeletal muscle mass (SMM) is one of the major components of human body composition, with deviations from normal values often leading to sarcopenia. Our major aim was to conduct a genome-wide DNA methylation study in an attempt to identify potential genomic regions associated with SMM. This was a mixed cross-sectional and longitudinal study. Community-based study. A total of 1550 middle-aged United Kingdom twins (monozygotic [MZ] and dizygotic [DZ]), 297 of which were repeatedly measured participated in the study. Appendicular lean mass assessed using dual-energy X-ray absorptiometry technology, and methylated DNA immunoprecipitation sequencing DNA methylation profiling genome-wide were obtained from each individual. Heritability estimate of SMM, with simultaneous adjustment for covariates obtained using variance decomposition analysis, was h(2) = 0.809 ± 0.050. After quality control and analysis of longitudinal stability, the DNA methylation data comprised of 723 029 genomic sites, with positive correlations between repeated measurements (Rrepeated = 0.114-0.905). Correlations between MZ and DZ twins were 0.51 and 0.38 at a genome-wide average, respectively, and clearly increased with Rrepeated. Testing for DNA methylation association with SMM in 50 discordant MZ twins revealed 36 081 nominally significant results, of which the top-ranked 134 signals (P 0.40) were subjected to replication in the sample of 1196 individuals. Seven SMM methylation association signals replicated at a false discovery rate less than 0.1, and these were located in or near genes DNAH12, CAND1, CYP4F29P, and ZFP64, which have previously been highlighted in muscle-related studies. Adjusting for age, smoking, and blood cell heterogeneity did not alter significance of these associations. This epigenome-wide study, testing longitudinally stable methylation sites, discovered and replicated a number of associations between DNA methylation at CpG loci and SMM. Four replicated signals were

  8. Low-intensity aerobic exercise training: inhibition of skeletal muscle atrophy in high-fat-diet-induced ovariectomized rats.

    Kim, Hye Jin; Lee, Won Jun

    2017-09-30

    Postmenopausal women are highly susceptible to diseases, such as obesity, type 2 diabetes, osteoporosis, or skeletal muscle atrophy and many people recognize the need for regular physical activity. Aerobic exercise training is known to improve the oxidative capacity and insulin sensitivity of skeletal muscles. This study aimed to investigate the role of low-intensity aerobic exercise training on skeletal muscle protein degradation or synthesis in the plantaris muscles of high-fat-fed ovariectomized rats. Ovariectomized female rats were divided into two groups: a high-fat diet-sedentary group (HFD), and a high-fat diet-aerobic exercise group (HFD+EX). The exercise group exercised aerobically on a treadmill 5 days/week for 8 weeks. The rats progressively ran 30 min/day at 15 m/min, up to 40 min/day at 18 m/min, 0% slope, in the last 4 weeks. Although aerobic exercise led to significantly increased AMP-activated protein kinase (AMPK) phosphorylation at Thr172, phosphorylation of the mammalian target of rapamycin (mTOR) substrate Thr389 S6K1 level did not decrease. Additionally, even though Akt activity did not increase at Ser473, the atrogin-1 level significantly decreased in the exercise group compared to the non-exercise group. Immunohistochemical staining revealed that high-fat-induced TSC2 protein expression was eliminated in response to aerobic exercise. These results suggest that aerobic exercise can inhibit skeletal muscle protein degradation, but it cannot increase protein synthesis in the plantaris muscle of high-fat-fed ovariectomized rats. Our findings have implications in understanding skeletal muscle mass maintenance with low intensity aerobic exercise in post-menopausal women. ©2017 The Korean Society for Exercise Nutrition

  9. Effects of anabolic steroids and high-intensity aerobic exercise on skeletal muscle of transgenic mice.

    Karina Fontana

    Full Text Available In an attempt to shorten recovery time and improve performance, strength and endurance athletes occasionally turn to the illicit use of anabolic-androgenic steroids (AAS. This study evaluated the effects of AAS treatment on the muscle mass and phenotypic characteristics of transgenic mice subjected to a high-intensity, aerobic training program (5d/wk for 6 weeks. The transgenic mice (CETP(+/-LDLr(-/+ were engineered to exhibit a lipid profile closer to humans. Animals were divided into groups of sedentary (Sed and/or training (Ex mice (each treated orally with AAS or gum arabic/vehicle: Sed-C, Sed-M, ex-C, ex-M. The effects of AAS (mesterolone: M on specific phenotypic adaptations (muscle wet weight, cross-sectional area, and fiber type composition in three hindlimb muscles (soleus:SOL, tibialis anterior:TA and gastrocnemius:GAS were assessed. In order to detect subtle changes in fiber type profile, the entire range of fiber types (I, IC, IIAC, IIA, IIAD, IID, IIDB, IIB was delineated using mATPase histochemistry. Body weight gain occurred throughout the study for all groups. However, the body weight gain was significantly minimized with exercise. This effect was blunted with mesterolone treatment. Both AAS treatment (Sed-M and high-intensity, aerobic training (ex-C increased the wet weights of all three muscles and induced differential hypertrophy of pure and hybrid fibers. Combination of AAS and training (ex-M resulted in enhanced hypertrophy. In the SOL, mesterolone treatment (Sed-M and ex-M caused dramatic increases in the percentages of fiber types IC, IIAC, IIAD, IID, with concomitant decrease in IIA, but had minimal impact on fiber type percentages in the predominantly fast muscles. Overall, the AAS-induced differential adaptive changes amounted to significant fiber type transformations in the fast-to-slow direction in SOL. AAS treatment had a significant effect on muscle weights and fiber type composition in SOL, TA and GAS which was

  10. High Fat Diet-Induced Skeletal Muscle Wasting Is Decreased by Mesenchymal Stem Cells Administration: Implications on Oxidative Stress, Ubiquitin Proteasome Pathway Activation, and Myonuclear Apoptosis

    Johanna Abrigo

    2016-01-01

    Full Text Available Obesity can lead to skeletal muscle atrophy, a pathological condition characterized by the loss of strength and muscle mass. A feature of muscle atrophy is a decrease of myofibrillar proteins as a result of ubiquitin proteasome pathway overactivation, as evidenced by increased expression of the muscle-specific ubiquitin ligases atrogin-1 and MuRF-1. Additionally, other mechanisms are related to muscle wasting, including oxidative stress, myonuclear apoptosis, and autophagy. Stem cells are an emerging therapy in the treatment of chronic diseases such as high fat diet-induced obesity. Mesenchymal stem cells (MSCs are a population of self-renewable and undifferentiated cells present in the bone marrow and other mesenchymal tissues of adult individuals. The present study is the first to analyze the effects of systemic MSC administration on high fat diet-induced skeletal muscle atrophy in the tibialis anterior of mice. Treatment with MSCs reduced losses of muscle strength and mass, decreases of fiber diameter and myosin heavy chain protein levels, and fiber type transitions. Underlying these antiatrophic effects, MSC administration also decreased ubiquitin proteasome pathway activation, oxidative stress, and myonuclear apoptosis. These results are the first to indicate that systemically administered MSCs could prevent muscle wasting associated with high fat diet-induced obesity and diabetes.

  11. Dual-energy X-ray absorptiometry is a valid tool for assessing skeletal muscle mass in older women.

    Chen, Zhao; Wang, ZiMian; Lohman, Timothy; Heymsfield, Steven B; Outwater, Eric; Nicholas, Jennifer S; Bassford, Tamsen; LaCroix, Andrea; Sherrill, Duane; Punyanitya, Mark; Wu, Guanglin; Going, Scott

    2007-12-01

    Assessing skeletal muscle mass (SMM) is critical in studying and detecting sarcopenia. Direct measurements by MRI or computerized tomography are expensive or high in radiation exposure. Dual-energy X-ray absorptiometry (DXA) is promising for body composition assessments, but the validity of DXA for predicting SMM in the elderly is still under investigation. The objective of this study was to assess the relationship between DXA-derived measurements of lean soft tissue mass (LSTM) and SMM in older women. Study participants were postmenopausal women (n = 101) recruited in southern Arizona. Total and regional body composition was measured using MRI and DXA (QDR4500w). The participants' mean age was 70.7 +/- 6.4 y and their mean BMI was 27.4 +/- 5.1 kg/m2. DXA-derived LSTM was highly correlated with MRI-derived SMM for the whole body (r = 0.94; P LSTM assessments for the leg region but not for the total body. In conclusion, although the relationships between DXA measures and MRI-derived SMM vary by region of interest, the overall prediction of SMM by DXA is excellent. We conclude that DXA is a reliable method for cross-sectional assessments of SMM in older women.

  12. Electrically Stimulated Antagonist Muscle Contraction Increased Muscle Mass and Bone Mineral Density of One Astronaut - Initial Verification on the International Space Station.

    Shiba, Naoto; Matsuse, Hiroo; Takano, Yoshio; Yoshimitsu, Kazuhiro; Omoto, Masayuki; Hashida, Ryuki; Tagawa, Yoshihiko; Inada, Tomohisa; Yamada, Shin; Ohshima, Hiroshi

    2015-01-01

    Musculoskeletal atrophy is one of the major problems of extended periods of exposure to weightlessness such as on the International Space Station (ISS). We developed the Hybrid Training System (HTS) to maintain an astronaut's musculoskeletal system using an electrically stimulated antagonist to resist the volitional contraction of the agonist instead of gravity. The present study assessed the system's orbital operation capability and utility, as well as its preventative effect on an astronaut's musculoskeletal atrophy. HTS was attached to the non-dominant arm of an astronaut staying on the ISS, and his dominant arm without HTS was established as the control (CTR). 10 sets of 10 reciprocal elbow curls were one training session, and 12 total sessions of training (3 times per week for 4 weeks) were performed. Pre and post flight ground based evaluations were performed by Biodex (muscle performance), MRI (muscle volume), and DXA (BMD, lean [muscle] mass, fat mass). Pre and post training inflight evaluations were performed by a hand held dynamometer (muscle force) and a measuring tape (upper arm circumference). The experiment was completed on schedule, and HTS functioned well without problems. Isokinetic elbow extension torque (Nm) changed -19.4% in HTS, and -21.7% in CTR. Isokinetic elbow flexion torque changed -23.7% in HTS, and there was no change in CTR. Total Work (Joule) of elbow extension changed -8.3% in HTS, and +0.3% in CTR. For elbow flexion it changed -23.3% in HTS and -32.6% in CTR. Average Power (Watts) of elbow extension changed +22.1% in HTS and -8.0% in CTR. For elbow flexion it changed -6.5% in HTS and -4.8% in CTR. Triceps muscle volume according to MRI changed +11.7% and that of biceps was +2.1% using HTS, however -0.1% and -0.4% respectively for CTR. BMD changed +4.6% in the HTS arm and -1.2% for CTR. Lean (muscle) mass of the arm changed only +10.6% in HTS. Fat mass changed -12.6% in HTS and -6.4% in CTR. These results showed the orbital operation

  13. Electrically Stimulated Antagonist Muscle Contraction Increased Muscle Mass and Bone Mineral Density of One Astronaut - Initial Verification on the International Space Station.

    Naoto Shiba

    Full Text Available Musculoskeletal atrophy is one of the major problems of extended periods of exposure to weightlessness such as on the International Space Station (ISS. We developed the Hybrid Training System (HTS to maintain an astronaut's musculoskeletal system using an electrically stimulated antagonist to resist the volitional contraction of the agonist instead of gravity. The present study assessed the system's orbital operation capability and utility, as well as its preventative effect on an astronaut's musculoskeletal atrophy.HTS was attached to the non-dominant arm of an astronaut staying on the ISS, and his dominant arm without HTS was established as the control (CTR. 10 sets of 10 reciprocal elbow curls were one training session, and 12 total sessions of training (3 times per week for 4 weeks were performed. Pre and post flight ground based evaluations were performed by Biodex (muscle performance, MRI (muscle volume, and DXA (BMD, lean [muscle] mass, fat mass. Pre and post training inflight evaluations were performed by a hand held dynamometer (muscle force and a measuring tape (upper arm circumference.The experiment was completed on schedule, and HTS functioned well without problems. Isokinetic elbow extension torque (Nm changed -19.4% in HTS, and -21.7% in CTR. Isokinetic elbow flexion torque changed -23.7% in HTS, and there was no change in CTR. Total Work (Joule of elbow extension changed -8.3% in HTS, and +0.3% in CTR. For elbow flexion it changed -23.3% in HTS and -32.6% in CTR. Average Power (Watts of elbow extension changed +22.1% in HTS and -8.0% in CTR. For elbow flexion it changed -6.5% in HTS and -4.8% in CTR. Triceps muscle volume according to MRI changed +11.7% and that of biceps was +2.1% using HTS, however -0.1% and -0.4% respectively for CTR. BMD changed +4.6% in the HTS arm and -1.2% for CTR. Lean (muscle mass of the arm changed only +10.6% in HTS. Fat mass changed -12.6% in HTS and -6.4% in CTR.These results showed the orbital

  14. Similar effects of leucine rich and regular dairy products on muscle mass and functions of older polymyalgia rheumatica patients: a randomized crossover trial.

    Björkman, M P; Pilvi, T K; Kekkonen, R A; Korpela, R; Tilvis, R S

    2011-06-01

    Leucine-rich milk and whey proteins have been suggested for prevention of age related loss of muscle mass and strength i.e. sarcopenia. The effects of milk protein supplementation and low intensity home based physical exercise on body composition and muscle functions were investigated. A randomized double blind crossover trial. Community dwelling members of Helsinki rheumatoid association. Older people (N=47, mean age 69.5 years) suffering from polymyalgia rheumatica. Patients performed as many stand ups as possible twice a day after which they ingested a regular (Control) or a whey protein enriched dairy product with high leucine content (Test). The 8-week intervention periods were separated by a 4-week wash-out. Body composition was measured by dual x-ray absorptiometry and muscle functions by hand grip strength, force platform countermovement jump performance, chair stand test, and walking speed. The 16-week home-based post-exercise supplementation resulted in a 1.8% increase (p = 0.052) in lower limb muscle mass. Walking speed (+5.3%, p = 0.007) and chair stand test performance (-12.2 %, p products prevent or treat age-associated sarcopenia and whether they are superior to the present commercial milk products.

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

    Gorissen, Stefan Hm; Horstman, Astrid Mh; Franssen, Rinske; Kouw, Imre Wk; Wall, Benjamin T; Burd, Nicholas A; de Groot, Lisette Cpgm; van Loon, Luc Jc

    2017-02-01

    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 protein intake (HIGH PRO) on the postprandial muscle protein synthetic response. We assessed the impact of LOW PRO compared with HIGH PRO on basal and postprandial muscle protein synthesis rates after the ingestion of 25 g whey protein. Twenty-four healthy, older men [age: 62 ± 1 y; body mass index (in kg/m 2 ): 25.9 ± 0.4 (mean ± SEM)] participated in a parallel-group randomized trial in which they adapted to either a LOW PRO diet (0.7 g · kg -1 · d -1 ; n = 12) or a HIGH PRO diet (1.5 g · kg -1 · d -1 ; n = 12) for 14 d. On day 15, participants received primed continuous l-[ring- 2 H 5 ]-phenylalanine and l-[1- 13 C]-leucine infusions and ingested 25 g intrinsically l-[1- 13 C]-phenylalanine- and l-[1- 13 C]-leucine-labeled whey protein. Muscle biopsies and blood samples were collected to assess muscle protein synthesis rates as well as dietary protein digestion and absorption kinetics. Plasma leucine concentrations and exogenous phenylalanine appearance rates increased after protein ingestion (P 0.05). Plasma exogenous phenylalanine availability over the 5-h postprandial period was greater after LOW PRO than after HIGH PRO (61% ± 1% compared with 56% ± 2%, respectively; P protein synthesis rates increased from 0.031% ± 0.004% compared with 0.039% ± 0.007%/h in the fasted state to 0.062% ± 0.005% compared with 0.057% ± 0.005%/h in the postprandial state after LOW PRO compared with HIGH PRO, respectively (P protein-derived amino acids in the circulation and does not lower basal muscle protein synthesis rates or increase postprandial muscle protein synthesis rates after ingestion of 25 g protein in older men. This trial was registered at clinicaltrials.gov as NCT

  16. Deficiency of heat shock transcription factor 1 suppresses heat stress-associated increase in slow soleus muscle mass of mice.

    Ohno, Y; Egawa, T; Yokoyama, S; Nakai, A; Sugiura, T; Ohira, Y; Yoshioka, T; Goto, K

    2015-12-01

    Effects of heat shock transcription factor 1 (HSF1) deficiency on heat stress-associated increase in slow soleus muscle mass of mice were investigated. Both HSF1-null and wild-type mice were randomly assigned to control and heat-stressed groups. Mice in heat-stressed group were exposed to heat stress (41 °C for 60 min) in an incubator without anaesthesia. Significant increase in wet and dry weights, and protein content of soleus muscle in wild-type mice was observed seven days after the application of the heat stress. However, heat stress had no impact on soleus muscle mass in HSF1-null mice. Neither type of mice exhibited much effect of heat stress on HSF mRNA expression (HSF1, HSF2 and HSF4). On the other hand, heat stress upregulated heat shock proteins (HSPs) at the mRNA (HSP72) and protein (HSP72 and HSP110) levels in wild-type mice, but not in HSF1-null mice. The population of Pax7-positive nuclei relative to total myonuclei of soleus muscle in wild-type mice was significantly increased by heat stress, but not in HSF1-null mice. Furthermore, the absence of HSF1 gene suppressed heat stress-associated phosphorylation of Akt and p70 S6 kinase (p-p70S6K) in soleus muscle. Heat stress-associated increase in skeletal muscle mass may be induced by HSF1 and/or HSF1-mediated stress response that activates muscle satellite cells and Akt/p70S6K signalling pathway. © 2015 Scandinavian Physiological Society. Published by John Wiley & Sons Ltd.

  17. Low vitamin D status is associated with reduced muscle mass and impaired physical performance in frail elderly people

    Tieland, C.A.B.; Brouwer, E.M.; Nienaber-Rousseau, C.; Loon, van L.J.C.; Groot, de C.P.G.M.

    2013-01-01

    Background/Objectives: Serum 25-hydroxyvitamin D (25(OH)D) status has been associated with muscle mass, strength and physical performance in healthy elderly people. Yet, in pre-frail and frail elderly people this association has not been studied. The objective of this study was to explore the

  18. The impact of dietary protein or amino acid supplementation on muscle mass and strength in elderly people

    Tieland, M.; Franssen, R.; Dullemeijer, C.; Dronkelaar, van C.; Kim, H.K.; Ispoglou, T.; Zhu, K.; Prince, R.L.; Loon, van L.J.C.; Groot, de Lisette C.P.G.M.

    2017-01-01

    Objectives: Increasing protein or amino acid intake has been promoted as a promising strategy to increase muscle mass and strength in elderly people, however, long-term intervention studies show inconsistent findings. Therefore, we aim to determine the impact of protein or amino acid

  19. Low skeletal muscle mass is associated with increased hospital expenditure in patients undergoing cancer surgery of the alimentary tract

    J.L.A. van Vugt (Jeroen); S. Büttner (Stefan); S. Levolger (S.); R.R.J. Coebergh van den Braak (Robert); M. Suker (Mustafa); M.P. Gaspersz (Marcia); R.W.F. de Bruin (Ron); C. Verhoef (Kees); Van Eijck, C.H.C. (Casper H. C.); Bossche, N. (Niek); B. Groot Koerkamp (Bas); J.N.M. IJzermans (Jan)

    2017-01-01

    textabstractBackground: Low skeletal muscle mass is associated with poor postoperative outcomes in cancer patients. Furthermore, it is associated with increased healthcare costs in the United States. We investigated its effect on hospital expenditure in a Western-European healthcare system, with

  20. Basic Training of Student’s Outdoor Club Increases Muscle Mass after Five Weeks of Exercise in Males

    Novie Salsabila

    2015-03-01

    Full Text Available Background: Aerobic and anaerobic exercises, may lead to increase muscle mass. The aim of this study was to determine the change in muscle mass during basic training of students’ outdoor club. Methods: This was an observational analytic study to college students who joined basic training of students’ outdoor club for 19 weeks. Subjects consisted of 17 male and 15 female students, measured five times consecutively by using Body Fat/Hydration monitor scale, with Bioelectrical Impedance Analysis principle. Data collection was performed five times, from February to July 2012 in Bandung. Statistical analysis was processed using Analysis of Variance (ANOVA. Results: The result in males showed the mean 43.35±3.15 on the initial measurement. The muscle mass further increased significantly after five, ten, fifteen, and nineteen weeks of exercise (43.73±3.18 (p0.05; 38.08±1.67 (p>0.05 ; 38.23±1.52 (p>0.05 ; 38.61±1.52 (p<0.05 vs 37.77±2.00 respectively. Conclusion: Basic training of student’s outdoor club increases muscle mass significantly after five weeks of exercise in males, but not in females

  1. Accessory brachialis muscle associated with high division of brachial artery

    Krishnamurthy A; David S; Bagoji IB; Nayak SR; Pai MM; Murlimanju BV; Kumar GC

    2010-01-01

    During routine dissection for the undergraduate students in the Department of Anatomy, Kasturba Medical College, Mangalore, of a male cadaver aged 73 years, we encountered an additional slip of brachialis muscle taking origin in the flexor compartment of left arm and inserting into the forearm. The origin of the additional muscle belly was from the anteromedial surface of shaft and medial supracondylar ridge of lower end of humerus. The additional muscle slip merged with the tendon of pronato...

  2. Measurement of Muscle Protein Fractional Synthetic Rate by Capillary Gas Chromatography/Combustion Isotope Ratio Mass Spectrometry

    Yarasheski, Kevin E.; Smith, Kenneth; Rennie, Michael J.; Bier, Dennis M.

    2014-01-01

    The measurement of skeletal muscle protein fractional synthetic rate using an infusion of (1-13C)leucine and measuring the isotopic abundance of the tracer in skeletal muscle protein by preparative gas chromatography (GC)/ninhydrin isotope ratio mass spectrometry (IRMS) is laborious and subject to errors owing to contamination by 12C. The purpose of this study was to compare muscle (13C)leucine enrichment measured with the conventional preparative GC/ninhydrin IRMS approach to a new, continuous-flow technique using capillary GC/combustion IRMS. Quadriceps muscles were removed from four Sprague–Dawley rats after each was infused at a different rate with (1-13C)leucine for 6–8 h. Muscle leucine enrichment (at.% excess) measured by both methods differed by less than 4%, except at low (13C)leucine enrichments (IRMS was used to assess muscle (13C)leucine enrichment and fractional muscle protein synthesis rate in ten normal young men and women infused with (1,2-13C2)leucine for 12–14 h. This approach reduced the variability of the isotope abundance measure and gave estimates of muscle protein synthesis rate (0.050 ± 0.011% h−1 (mean ± SEM); range = 0.023–0.147% h−1) that agree with published values determined using the standard analytical approach. The measurement of (13C)leucine enrichment from skeletal muscle protein by capillary GC/combustion IRMS provides a simple, acceptable and practical alternative to preparative GC/ninhydrin IRMS. PMID:1420371

  3. Reference Centile Curves for Body Fat Percentage, Fat-free Mass, Muscle Mass and Bone Mass Measured by Bioelectrical Impedance in Asian Indian Children and Adolescents.

    Chiplonkar, Shashi; Kajale, Neha; Ekbote, Veena; Mandlik, Rubina; Parthasarathy, Lavanya; Borade, Ashwin; Patel, Pinal; Patel, Prerna; Khadilkar, Vaman; Khadilkar, Anuradha

    2017-12-15

    To create gender-specific percentile curves for percent body fat (%BF) by Bio electrical Impedance Analysis (BIA) for screening adiposity and risk of hypertension in Indian children and generate reference curves for percent fat-free mass (%FFM), muscle mass (%LM) and bone mineral content (BMC) by using bioelectrical impedance. Secondary analysis of data from previous multicenter cross-sectional studies. Private schools from five regions of India. A random sample of 3850 healthy school children (2067 boys) (5-17 yr) from private schools in five major Indian cities. Anthropometry, blood pressure (BP) and body composition were measured by bioelectrical impedance. Reference curves were generated by the LMS method. %BF, %FFM, %LM, BMC and BP. Median %BF increased by 6% from 5 to 13 years of age and declined (around 2%) up to 17 years in boys. In girls, %BF increased by 8% from 5 to 14 years and thereafter declined by 3%. Based upon the risk of hypertension, the new cut-offs of 75th and 85th percentile of %BF were proposed for detecting over fatness and excess fatness in children. Median %FFM was 90% at 5 yrs and decreased till 12 years, and then showed a slight increase to 84% at 17 yrs in boys. In girls, it was 86% at 5 yrs and decreased till 15 yrs, and plateaued at 71.8% at 17 yrs. Reference curves for percent body fat for Indian children would be useful to screen children for health risk in clinical set up.

  4. High responders to resistance exercise training demonstrate differential regulation of skeletal muscle microRNA expression

    Davidsen, Peter K; Gallagher, Iain J; Hartman, Joseph W

    2011-01-01

    MicroRNAs (miRNA), small noncoding RNA molecules, may regulate protein synthesis, while resistance exercise training (RT) is an efficient strategy for stimulating muscle protein synthesis in vivo. However, RT increases muscle mass, with a very wide range of effectiveness in humans. We therefore...... determined the expression level of 21 abundant miRNAs to determine whether variation in these miRNAs was able to explain the variation in RT-induced gains in muscle mass. Vastus lateralis biopsies were obtained from the top and bottom ~20% of responders from 56 young men who undertook a 5 day/wk RT program...... for 12 wk. Training-induced muscle mass gain was determined by dual-energy X-ray absorptiometry, and fiber size was evaluated by histochemistry. The expression level of each miRNA was quantified using TaqMan-based quantitative PCR, with the analysis carried out in a blinded manner. Gene ontology...

  5. High body mass index and cancer risk

    Benn, Marianne; Tybjærg-Hansen, Anne; Smith, George Davey

    2016-01-01

    of follow-up (range 0-37), 8002 developed non-skin cancer, 3347 non-melanoma skin cancer, 1396 lung cancer, 637 other smoking related cancers, 1203 colon cancer, 159 kidney cancer, 1402 breast cancer, 1062 prostate cancer, and 2804 other cancers. Participants were genotyped for five genetic variants...... with a BMI ≥ 30 versus 18.5-24.9 kg/m(2). Corresponding risk of breast cancer was 20 % (0-44 %) higher in postmenopausal women. BMI was not associated with risk of colon, kidney, other smoking related cancers, prostate cancer, or other cancers. In genetic analyses, carrying 7-10 versus 0-4 BMI increasing......High body mass index (BMI) has been associated with increased risk of some cancer. Whether these reflect causal associations is unknown. We examined this issue. Using a Mendelian randomisation approach, we studied 108,812 individuals from the general population. During a median of 4.7 years...

  6. MALDI imaging mass spectrometry: Discrimination of pathophysiological regions in traumatized skeletal muscle by characteristic peptide signatures

    Klein, O.; Strohschein, K.; Nebrich, G.; Oetjen, J.; Trede, D.; Thiele, H.; Alexandrov, T.; Giavalisco, P.; Duda, G.N.; Roth, P. von; Geissler, S.; Klose, J.; Winkler, T.

    2014-01-01

    Due to formation of fibrosis and the loss of contractile muscle tissue, severe muscle injuries often result in insufficient healing marked by a significant reduction of muscle force and motor activity. Our previous studies demonstrated that the local transplantation of mesenchymal stromal cells into an injured skeletal muscle of the rat improves the functional outcome of the healing process. Since, due to the lack of sufficient markers, the accurate discrimination of pathophysiological region...

  7. Muscle strength and regional lean body mass influence on mineral bone health in young male adults.

    Guimarães, Bianca Rosa; Pimenta, Luciana Duarte; Massini, Danilo Alexandre; Dos Santos, Daniel; Siqueira, Leandro Oliveira da Cruz; Simionato, Astor Reis; Dos Santos, Luiz Gustavo Almeida; Neiva, Cassiano Merussi; Pessôa Filho, Dalton Muller

    2018-01-01

    The relationship between muscle strength and bone mineral content (BMC) and bone mineral density (BMD) is supposed from the assumption of the mechanical stress influence on bone tissue metabolism. However, the direct relationship is not well established in younger men, since the enhancement of force able to produce effective changes in bone health, still needs to be further studied. This study aimed to analyze the influence of muscle strength on BMC and BMD in undergraduate students. Thirty six men (24.9 ± 8.6 y/o) were evaluated for regional and whole-body composition by dual energy X-ray absorptiometry (DXA). One repetition maximum tests (1RM) were assessed on flat bench-press (BP), lat-pull down (LPD), leg-curl (LC), knee extension (KE), and leg-press 45° (LP45) exercises. Linear regression modelled the relationships of BMD and BMC to the regional body composition and 1RM values. Measurements of dispersion and error (R2adj and standard error of estimate (SEE)) were tested, setting ρ at ≤0.05. The BMD mean value for whole-body was 1.12±0.09 g/cm2 and BMC attained 2477.9 ± 379.2 g. The regional lean mass (LM) in upper-limbs (UL) (= 6.80±1.21 kg) was related to BMC and BMD for UL (R2adj = 0.74, pBMC and BMD for LL (R2adj = 0.68, pBMC (R2adj = 0.47, pBMC (R2adj = 0.36, pBMC and BMD in young men, strengthening the relationship between force and LM, and suggesting both to parametrizes bone mineral health.

  8. Assessment of respiratory muscle strength in children according to the classification of body mass index

    George Jung da Rosa

    2014-06-01

    Full Text Available OBJECTIVE: To assess and compare the respiratory muscle strength among eutrophic, overweight and obese school children, as well as to identify anthropometric and respiratory variables related to the results.METHODS: Cross-sectional survey with healthy schoolchildren aged 7-9 years old, divided into three groups: Normal weight, Overweight and Obese. The International Study of Asthma and Allergies in Childhood (ISAAC questionnaire was applied. The body mass index (BMI was evaluated, as well as the forced expiratory volume in one second (FEV1 with a portable digital device. The maximal inspiratory and expiratory pressures (MIP and MEP were measured by a digital manometer. Comparisons between the groups were made by Kruskal-Wallis test. Spearman's correlation coefficient was used to analyze the correlations among the variables.RESULTS: MIP of eutrophic school children was higher than MIP found in overweight (p=0.043 and obese (p=0.013 children. MIP was correlated with BMI percentile and weight classification (r=-0.214 and r=-0.256 and MEP was correlated with height (r=0.328. Both pressures showed strong correlation with each other in all analyses (r≥0.773, and less correlation with FEV1 (MIP - r=0.362 and MEP - r=0.494. FEV1 correlated with MEP in all groups (r: 0.429 - 0.569 and with MIP in Obese Group (r=0.565. Age was correlated with FEV1 (r=0.578, MIP (r=0.281 and MEP (r=0.328.CONCLUSIONS: Overweight and obese children showed lower MIP values, compared to eutrophic ones. The findings point to the influence of anthropometric variables on respiratory muscle strength in children.

  9. What's So Special about FGF19-Unique Effects Reported on Skeletal Muscle Mass and Function.

    Glass, David J

    2017-08-01

    In a recent study published in Nature Medicine, Benoit et al. (2017) reported unique effects of FGF19 on mouse skeletal muscle: FGF19 induced skeletal muscle hypertrophy and blocked muscle atrophy, acting via FGF receptors and ßKlotho, while a related FGF21 hormone was ineffective. Copyright © 2017 Elsevier Inc. All rights reserved.

  10. Effect of pretreatment psoas muscle mass on survival for patients with unresectable pancreatic cancer undergoing systemic chemotherapy.

    Ishii, Noriko; Iwata, Yoshinori; Nishikawa, Hiroki; Enomoto, Hirayuki; Aizawa, Nobuhiro; Ishii, Akio; Miyamoto, Yuho; Yuri, Yukihisa; Hasegawa, Kunihiro; Nakano, Chikage; Nishimura, Takashi; Yoh, Kazunori; Sakai, Yoshiyuki; Ikeda, Naoto; Takashima, Tomoyuki; Takata, Ryo; Iijima, Hiroko; Nishiguchi, Shuhei

    2017-11-01

    To the best of our knowledge, there are few previous studies that have investigated the effect of decreased skeletal muscle mass (DSMM) on survival in patients with unresectable advanced pancreatic cancer (APC) who are undergoing systemic chemotherapy. Thus, the present study aimed to investigate the impact of DSMM, as determined by the psoas muscle index (PMI) following computed tomography and prior to systemic chemotherapy, on the outcomes of patients with unresectable APC (n=61). The primary endpoint used was the overall survival (OS) rate. The OS rates in the PMI-High group (exceeds the median PMI value in each gender) were retrospectively compared with those in the PMI-Low group (below the median PMI value in each gender), and factors associated with OS were investigated using univariate and multivariate analyses. The study cohort included 31 male and 30 female patients with a median age of 72 years, 13 of whom were stage IVA, and 48 were stage IVB. The median PMI in males was 4.3 cm 2 /m 2 (range, 1.6-8.2 cm 2 /m 2 ), while that in females was 2.3 cm 2 /m 2 (range, 0.7-6.1 cm 2 /m 2 ). The proportion of patients with performance status 0 in the PMI-High group was significantly high, compared with that in the PMI-Low group [83.3% (25/30) vs. 58.1% (18/31); P=0.0486]. Body mass index in the PMI-High group was significantly higher compared with that in the PMI-Low group (P=0.0154). The 1-year cumulative survival rate was 43.3% in the PMI-High group and 12.9% in the PMI-Low group (P=0.0027). Following multivariate analysis, PMI (P=0.0036), prothrombin time (P=0.0044) and carbohydrate antigen 19-9 (P=0.0451) were identified to be significant predictors of OS. In conclusion, DSMM, as determined by the PMI, could be a significant predictor of prognosis in patients with unresectable APC who are receiving systemic chemotherapy.

  11. Impact of Weight Loss on Physical Function with Changes in Strength, Muscle Mass, and Muscle Fat Infiltration in Overweight to Moderately Obese Older Adults: A Randomized Clinical Trial

    Adam J. Santanasto

    2011-01-01

    Full Text Available Purpose. Evaluate the effects of weight loss on muscle mass and area, muscle fat infiltration, strength, and their association with physical function. Methods. Thirty-six overweight to moderately obese, sedentary older adults were randomized into either a physical activity plus weight loss (PA+WL or physical activity plus successful aging health education (PA+SA program. Measurements included body composition by dual-energy X-ray absorptiometry, computerized tomography, knee extensor strength, and short physical performance battery (SPPB. Results. At 6 months, PA+WL lost greater thigh fat and muscle area compared to PA+SA. PA+WL lost 12.4% strength; PA+SA lost 1.0%. Muscle fat infiltration decreased significantly in PA+WL and PA+SA. Thigh fat area decreased 6-fold in comparison to lean area in PA+WL. Change in total SPPB score was strongly inversely correlated with change in fat but not with change in lean or strength. Conclusion. Weight loss resulted in additional improvements in function over exercise alone, primarily due to loss of body fat.

  12. Excess glycogen does not resolve high ultimate pH of oxidative muscle.

    England, Eric M; Matarneh, Sulaiman K; Oliver, Emily M; Apaoblaza, Ariel; Scheffler, Tracy L; Shi, Hao; Gerrard, David E

    2016-04-01

    Skeletal muscle glycogen content can impact the extent of postmortem pH decline. Compared to glycolytic muscles, oxidative muscles contain lower glycogen levels antemortem which may contribute to the higher ultimate pH. In an effort to explore further the participation of glycogen in postmortem metabolism, we postulated that increasing the availability of glycogen would drive additional pH decline in oxidative muscles to equivalent pH values similar to the ultimate pH of glycolytic muscles. Glycolysis and pH declines were compared in porcine longissimus lumborum (glycolytic) and masseter (oxidative) muscles using an in vitro system in the presence of excess glycogen. The ultimate pH of the system containing longissimus lumborum reached a value similar to that observed in intact muscle. The pH decline of the system containing masseter samples stopped prematurely resulting in a higher ultimate pH which was similar to that of intact masseter muscle. To investigate further, we titrated powdered longissimus lumborum and masseter samples in the reaction buffer. As the percentage of glycolytic sample increased, the ultimate pH decreased. These data show that oxidative muscle produces meat with a high ultimate pH regardless of glycogen content and suggest that inherent muscle factors associated with glycolytic muscle control the extent of pH decline in pig muscles. Copyright © 2015 Elsevier Ltd. All rights reserved.

  13. Lower Jump Power Rather Than Muscle Mass Itself is Associated with Vertebral Fracture in Community-Dwelling Elderly Korean Women.

    Lee, Eun Young; Lee, Su Jin; Kim, Kyoung Min; Seo, Da Hea; Lee, Seung Won; Choi, Han Sol; Kim, Hyeon Chang; Youm, Yoosik; Kim, Chang Oh; Rhee, Yumie

    2017-06-01

    Sarcopenia is considered to be a risk factor for osteoporotic fracture, which is a major health problem in elderly women. In this study, we aimed to investigate the association of sarcopenia, with regard to muscle mass and function, with prevalent vertebral fracture in community-dwelling elderly women. We recruited 1281 women aged 64 to 87 years from the Korean Urban Rural Elderly cohort study. Muscle mass and function were measured using bioimpedance analysis and jumping mechanography. Skeletal muscle index (SMI) and jump power were used as an indicator of muscle mass and function, respectively. Among the participants, we observed 282 (18.9%) vertebral fractures and 564 (44.0%) osteoporosis. Although age, body mass index, and prevalence of osteoporosis increased as both SMI and jump power decreased, prevalence of vertebral fracture increased only when jump power decreased. In univariate analysis, compared with the highest quartile of jump power, the lowest quartile had a significant odds ratio of 2.80 (95% CI 1.79-4.36) for vertebral fracture. This association between jump power and vertebral fracture remained significant, with an odds ratio of 3.04 (95% CI 1.77-5.23), even after adjusting for other risk factors including age, bone mineral density, previous fracture, and cognitive function. In contrast, there was no association between SMI and vertebral fracture. Based on our results, low jump power, but not SMI, is associated with vertebral fracture in community-dwelling elderly Korean women. This finding suggests that jump power may have a more important role than muscle mass itself for osteoporotic fracture.

  14. Contraction-induced increases in Na+-K+-ATPase mRNA levels in human skeletal muscle are not amplified by activation of additional muscle mass

    Nordsborg, Nikolai; Thomassen, Martin; Lundby, Carsten

    2005-01-01

    The present study tested the hypothesis that exercise with a large compared with a small active muscle mass results in a higher contraction-induced increase in Na+-K+-ATPase mRNA expression due to greater hormonal responses. Furthermore, the relative abundance of Na+-K+-ATPase subunit a1, a2, a3, a......% of the a2 expression, and no reliable detection of a3 and a4 was possible. In conclusion, activation of additional muscle mass does not result in a higher exercise-induced increase in Na+-K+-ATPase subunit-specific mRNA.......4, ß1, ß2, and ß3 mRNA in human skeletal muscle was investigated. On two occasions, eight subjects performed one-legged knee extension exercise (L) or combined one-legged knee extension and bilateral arm cranking (AL) for 5.00, 4.25, 3.50, 2.75, and 2.00 min separated by 3 min of rest. Leg exercise...

  15. Long-term high-level exercise promotes muscle reinnervation with age.

    Mosole, Simone; Carraro, Ugo; Kern, Helmut; Loefler, Stefan; Fruhmann, Hannah; Vogelauer, Michael; Burggraf, Samantha; Mayr, Winfried; Krenn, Matthias; Paternostro-Sluga, Tatjana; Hamar, Dusan; Cvecka, Jan; Sedliak, Milan; Tirpakova, Veronika; Sarabon, Nejc; Musarò, Antonio; Sandri, Marco; Protasi, Feliciano; Nori, Alessandra; Pond, Amber; Zampieri, Sandra

    2014-04-01

    The histologic features of aging muscle suggest that denervation contributes to atrophy, that immobility accelerates the process, and that routine exercise may protect against loss of motor units and muscle tissue. Here, we compared muscle biopsies from sedentary and physically active seniors and found that seniors with a long history of high-level recreational activity up to the time of muscle biopsy had 1) lower loss of muscle strength versus young men (32% loss in physically active vs 51% loss in sedentary seniors); 2) fewer small angulated (denervated) myofibers; 3) a higher percentage of fiber-type groups (reinnervated muscle fibers) that were almost exclusive of the slow type; and 4) sparse normal-size muscle fibers coexpressing fast and slow myosin heavy chains, which is not compatible with exercise-driven muscle-type transformation. The biopsies from the old physically active seniors varied from sparse fiber-type groupings to almost fully transformed muscle, suggesting that coexpressing fibers appear to fill gaps. Altogether, the data show that long-term physical activity promotes reinnervation of muscle fibers and suggest that decades of high-level exercise allow the body to adapt to age-related denervation by saving otherwise lost muscle fibers through selective recruitment to slow motor units. These effects on size and structure of myofibers may delay functional decline in late aging.

  16. Relating speech production to tongue muscle compressions using tagged and high-resolution magnetic resonance imaging

    Xing, Fangxu; Ye, Chuyang; Woo, Jonghye; Stone, Maureen; Prince, Jerry

    2015-03-01

    The human tongue is composed of multiple internal muscles that work collaboratively during the production of speech. Assessment of muscle mechanics can help understand the creation of tongue motion, interpret clinical observations, and predict surgical outcomes. Although various methods have been proposed for computing the tongue's motion, associating motion with muscle activity in an interdigitated fiber framework has not been studied. In this work, we aim to develop a method that reveals different tongue muscles' activities in different time phases during speech. We use fourdimensional tagged magnetic resonance (MR) images and static high-resolution MR images to obtain tongue motion and muscle anatomy, respectively. Then we compute strain tensors and local tissue compression along the muscle fiber directions in order to reveal their shortening pattern. This process relies on the support from multiple image analysis methods, including super-resolution volume reconstruction from MR image slices, segmentation of internal muscles, tracking the incompressible motion of tissue points using tagged images, propagation of muscle fiber directions over time, and calculation of strain in the line of action, etc. We evaluated the method on a control subject and two postglossectomy patients in a controlled speech task. The normal subject's tongue muscle activity shows high correspondence with the production of speech in different time instants, while both patients' muscle activities show different patterns from the control due to their resected tongues. This method shows potential for relating overall tongue motion to particular muscle activity, which may provide novel information for future clinical and scientific studies.

  17. Administration of soluble activin receptor 2B increases bone and muscle mass in a mouse model of osteogenesis imperfecta

    DiGirolamo, Douglas J.; Singhal, Vandana; Chang, Xiaoli; Lee, Se-Jin; Germain-Lee, Emily L.

    2015-01-01

    Osteogenesis imperfecta (OI) comprises a group of heritable connective tissue disorders generally defined by recurrent fractures, low bone mass, short stature and skeletal fragility. Beyond the skeletal complications of OI, many patients also report intolerance to physical activity, fatigue and muscle weakness. Indeed, recent studies have demonstrated that skeletal muscle is also negatively affected by OI, both directly and indirectly. Given the well-established interdependence of bone and skeletal muscle in both physiology and pathophysiology and the observations of skeletal muscle pathology in patients with OI, we investigated the therapeutic potential of simultaneous anabolic targeting of both bone and skeletal muscle using a soluble activin receptor 2B (ACVR2B) in a mouse model of type III OI (oim). Treatment of 12-week-old oim mice with ACVR2B for 4 weeks resulted in significant increases in both bone and muscle that were similar to those observed in healthy, wild-type littermates. This proof of concept study provides encouraging evidence for a holistic approach to treating the deleterious consequences of OI in the musculoskeletal system. PMID:26161291

  18. Screening halogenated environmental contaminants in biota based on isotopic pattern and mass defect provided by high resolution mass spectrometry profiling

    Cariou, Ronan, E-mail: laberca@oniris-nantes.fr; Omer, Elsa; Léon, Alexis; Dervilly-Pinel, Gaud; Le Bizec, Bruno

    2016-09-14

    In the present work, we addressed the question of global seeking/screening organohalogenated compounds in a large panel of complex biological matrices, with a particular focus on unknown chemicals that may be considered as potential emerging hazards. A fishing strategy was developed based on untargeted profiling among full scan acquisition datasets provided by high resolution mass spectrometry. Since large datasets arise from such profiling, filtering useful information stands as a central question. In this way, we took advantage of the exact mass differences between Cl and Br isotopes. Indeed, our workflow involved an innovative Visual Basic for Applications script aiming at pairing features according to this mass difference, in order to point out potential organohalogenated clusters, preceded by an automated peak picking step based on the centWave function (xcms package of open access R programming environment). Then, H/Cl-scale mass defect plots were used to visualize the datasets before and after filtering. The filtering script was successfully applied to a dataset generated upon liquid chromatography coupled to ESI(−)-HRMS measurement from one eel muscle extract, allowing for realistic manual investigations of filtered clusters. Starting from 9789 initial obtained features, 1994 features were paired in 589 clusters. Hexabromocyclododecane, chlorinated paraffin series and various other compounds have been identified or tentatively identified, allowing thus broad screening of organohalogenated compounds in this extract. Although realistic, manual review of paired clusters remains time consuming and much effort should be devoted to automation. - Highlights: • We address the screening of halogenated compounds in large Full Scan HRMS datasets. • The workflow involves peak picking, pairing script and review of paired features. • The pairing script is based on exact mass differences between Cl and Br isotopes. • H/Cl scale mass defect plots are used to

  19. Screening halogenated environmental contaminants in biota based on isotopic pattern and mass defect provided by high resolution mass spectrometry profiling

    Cariou, Ronan; Omer, Elsa; Léon, Alexis; Dervilly-Pinel, Gaud; Le Bizec, Bruno

    2016-01-01

    In the present work, we addressed the question of global seeking/screening organohalogenated compounds in a large panel of complex biological matrices, with a particular focus on unknown chemicals that may be considered as potential emerging hazards. A fishing strategy was developed based on untargeted profiling among full scan acquisition datasets provided by high resolution mass spectrometry. Since large datasets arise from such profiling, filtering useful information stands as a central question. In this way, we took advantage of the exact mass differences between Cl and Br isotopes. Indeed, our workflow involved an innovative Visual Basic for Applications script aiming at pairing features according to this mass difference, in order to point out potential organohalogenated clusters, preceded by an automated peak picking step based on the centWave function (xcms package of open access R programming environment). Then, H/Cl-scale mass defect plots were used to visualize the datasets before and after filtering. The filtering script was successfully applied to a dataset generated upon liquid chromatography coupled to ESI(−)-HRMS measurement from one eel muscle extract, allowing for realistic manual investigations of filtered clusters. Starting from 9789 initial obtained features, 1994 features were paired in 589 clusters. Hexabromocyclododecane, chlorinated paraffin series and various other compounds have been identified or tentatively identified, allowing thus broad screening of organohalogenated compounds in this extract. Although realistic, manual review of paired clusters remains time consuming and much effort should be devoted to automation. - Highlights: • We address the screening of halogenated compounds in large Full Scan HRMS datasets. • The workflow involves peak picking, pairing script and review of paired features. • The pairing script is based on exact mass differences between Cl and Br isotopes. • H/Cl scale mass defect plots are used to

  20. Identification of skeletal muscle mass depletion across age and BMI groups in health and disease--there is need for a unified definition.

    Bosy-Westphal, A; Müller, M J

    2015-03-01

    Although reduced skeletal muscle mass is a major predictor of impaired physical function and survival, it remains inconsistently diagnosed to a lack of standardized diagnostic approaches that is reflected by the variable combination of body composition indices and cutoffs. In this review, we summarized basic determinants of a normal lean mass (age, gender, fat mass, body region) and demonstrate limitations of different lean mass parameters as indices for skeletal muscle mass. A unique definition of lean mass depletion should be based on an indirect or direct measure of skeletal muscle mass normalized for height (fat-free mass index (FFMI), appendicular or lumbal skeletal muscle index (SMI)) in combination with fat mass. Age-specific reference values for FFMI or SMI are more advantageous because defining lean mass depletion on the basis of total FFMI or appendicular SMI could be misleading in the case of advanced age due to an increased contribution of connective tissue to lean mass. Mathematical modeling of a normal lean mass based on age, gender, fat mass, ethnicity and height can be used in the absence of risk-defined cutoffs to identify skeletal muscle mass depletion. This definition can be applied to identify different clinical phenotypes like sarcopenia, sarcopenic obesity or cachexia.

  1. Application of dynamic metabolomics to examine in vivo skeletal muscle glucose metabolism in the chronically high-fat fed mouse

    Kowalski, Greg M., E-mail: greg.kowalski@deakin.edu.au [Centre for Physical Activity and Nutrition Research, School of Exercise and Nutrition Sciences, Deakin University, Burwood, Victoria 3125 (Australia); De Souza, David P. [Metabolomics Australia, Bio21 Institute of Molecular Science and Biotechnology, University of Melbourne, Parkville, Victoria 3010 (Australia); Burch, Micah L. [Brigham and Women' s Hospital, Department of Medicine, Boston, MA (United States); Hamley, Steven [Centre for Physical Activity and Nutrition Research, School of Exercise and Nutrition Sciences, Deakin University, Burwood, Victoria 3125 (Australia); Kloehn, Joachim [Metabolomics Australia, Bio21 Institute of Molecular Science and Biotechnology, University of Melbourne, Parkville, Victoria 3010 (Australia); Selathurai, Ahrathy [Centre for Physical Activity and Nutrition Research, School of Exercise and Nutrition Sciences, Deakin University, Burwood, Victoria 3125 (Australia); Tull, Dedreia; O' Callaghan, Sean; McConville, Malcolm J. [Metabolomics Australia, Bio21 Institute of Molecular Science and Biotechnology, University of Melbourne, Parkville, Victoria 3010 (Australia); Bruce, Clinton R. [Centre for Physical Activity and Nutrition Research, School of Exercise and Nutrition Sciences, Deakin University, Burwood, Victoria 3125 (Australia)

    2015-06-19

    Rationale: Defects in muscle glucose metabolism are linked to type 2 diabetes. Mechanistic studies examining these defects rely on the use of high fat-fed rodent models and typically involve the determination of muscle glucose uptake under insulin-stimulated conditions. While insightful, they do not necessarily reflect the physiology of the postprandial state. In addition, most studies do not examine aspects of glucose metabolism beyond the uptake process. Here we present an approach to study rodent muscle glucose and intermediary metabolism under the dynamic and physiologically relevant setting of the oral glucose tolerance test (OGTT). Methods and results: In vivo muscle glucose and intermediary metabolism was investigated following oral administration of [U-{sup 13}C] glucose. Quadriceps muscles were collected 15 and 60 min after glucose administration and metabolite flux profiling was determined by measuring {sup 13}C mass isotopomers in glycolytic and tricarboxylic acid (TCA) cycle intermediates via gas chromatography–mass spectrometry. While no dietary effects were noted in the glycolytic pathway, muscle from mice fed a high fat diet (HFD) exhibited a reduction in labelling in TCA intermediates. Interestingly, this appeared to be independent of alterations in flux through pyruvate dehydrogenase. In addition, our findings suggest that TCA cycle anaplerosis is negligible in muscle during an OGTT. Conclusions: Under the dynamic physiologically relevant conditions of the OGTT, skeletal muscle from HFD fed mice exhibits alterations in glucose metabolism at the level of the TCA cycle. - Highlights: • Dynamic metabolomics was used to investigate muscle glucose metabolism in vivo. • Mitochondrial TCA cycle metabolism is altered in muscle of HFD mice. • This defect was not pyruvate dehydrogenase mediated, as has been previously thought. • Mitochondrial TCA cycle anaplerosis in muscle is virtually absent during the OGTT.

  2. Application of dynamic metabolomics to examine in vivo skeletal muscle glucose metabolism in the chronically high-fat fed mouse

    Kowalski, Greg M.; De Souza, David P.; Burch, Micah L.; Hamley, Steven; Kloehn, Joachim; Selathurai, Ahrathy; Tull, Dedreia; O'Callaghan, Sean; McConville, Malcolm J.; Bruce, Clinton R.

    2015-01-01

    Rationale: Defects in muscle glucose metabolism are linked to type 2 diabetes. Mechanistic studies examining these defects rely on the use of high fat-fed rodent models and typically involve the determination of muscle glucose uptake under insulin-stimulated conditions. While insightful, they do not necessarily reflect the physiology of the postprandial state. In addition, most studies do not examine aspects of glucose metabolism beyond the uptake process. Here we present an approach to study rodent muscle glucose and intermediary metabolism under the dynamic and physiologically relevant setting of the oral glucose tolerance test (OGTT). Methods and results: In vivo muscle glucose and intermediary metabolism was investigated following oral administration of [U- 13 C] glucose. Quadriceps muscles were collected 15 and 60 min after glucose administration and metabolite flux profiling was determined by measuring 13 C mass isotopomers in glycolytic and tricarboxylic acid (TCA) cycle intermediates via gas chromatography–mass spectrometry. While no dietary effects were noted in the glycolytic pathway, muscle from mice fed a high fat diet (HFD) exhibited a reduction in labelling in TCA intermediates. Interestingly, this appeared to be independent of alterations in flux through pyruvate dehydrogenase. In addition, our findings suggest that TCA cycle anaplerosis is negligible in muscle during an OGTT. Conclusions: Under the dynamic physiologically relevant conditions of the OGTT, skeletal muscle from HFD fed mice exhibits alterations in glucose metabolism at the level of the TCA cycle. - Highlights: • Dynamic metabolomics was used to investigate muscle glucose metabolism in vivo. • Mitochondrial TCA cycle metabolism is altered in muscle of HFD mice. • This defect was not pyruvate dehydrogenase mediated, as has been previously thought. • Mitochondrial TCA cycle anaplerosis in muscle is virtually absent during the OGTT

  3. Influence of muscle fiber type composition on early fat accumulation under high-fat diet challenge.

    Hua, Ning; Takahashi, Hirokazu; Yee, Grace M; Kitajima, Yoichiro; Katagiri, Sayaka; Kojima, Motoyasu; Anzai, Keizo; Eguchi, Yuichiro; Hamilton, James A

    2017-01-01

    To investigate whether differences in muscle fiber types affect early-stage fat accumulation, under high fat diet challenge in mice. Twelve healthy male C57BL/6 mice experienced with short-term (6 weeks) diet treatment for the evaluation of early pattern changes in muscular fat. The mice were randomly divided into two groups: high fat diet (n = 8) and normal control diet (n = 4). Extra- and intra-myocellular lipid (EMCL and IMCL) in lumbar muscles (type I fiber predominant) and tibialis anterior (TA) muscle (type II fiber predominant) were determined using magnetic resonance spectroscopy (MRS). Correlation of EMCL, IMCL and their ratio between TA and lumbar muscles was evaluated. EMCL increased greatly in both muscle types after high fat diet. IMCL in TA and lumbar muscles increased to a much lower extent, with a slightly greater increase in TA muscles. EMCLs in the 2 muscles were positively correlated (r = 0.84, p = 0.01), but IMCLs showed a negative relationship (r = -0.84, p = 0.01). In lumbar muscles, high fat diet significantly decreased type I fiber while it increased type II fiber (all p≤0.001). In TA muscle, there was no significant fiber type shifting (p>0.05). Under short-time high fat diet challenge, lipid tends to initially accumulate extra-cellularly. In addition, compared to type II dominant muscle, Type I dominant muscle was less susceptible to IMCL accumulation but more to fiber type shifting. These phenomena might reflect compensative responses of skeletal muscle to dietary lipid overload in order to regulate metabolic homeostasis.

  4. Physiological effects beyond the significant gain in muscle mass in sarcopenic elderly men: evidence from a randomized clinical trial using a protein-rich food

    Alemán-Mateo H

    2012-07-01

    Full Text Available Heliodoro Alemán-Mateo,1 Liliana Macías,1 Julián Esparza-Romero,1 Humberto Astiazaran-García,1 Ana Luz Blancas21Coordinación de Nutrición, Centro de Investigación en Alimentación y Desarrollo, AC, Hermosillo, Sonora, México; 2Dirección General de Servicios de Salud a la Persona, Hermosillo, Sonora, MéxicoBackground: Sarcopenia is strongly associated with an inadequate intake of dietary protein. Dietary protein supplementation boosts muscle-protein synthesis and increases muscle mass in the elderly. This study tested whether adding a protein-rich food, ricotta cheese, to the habitual diet increased total appendicular skeletal muscle mass and strength in elderly people.Methods: Participants (n = 40, were sarcopenic elderly men and women over 60 years of age. Two comparison groups were formed at random and followed for 3 months: the intervention group received 210 g/day of ricotta cheese plus the habitual diet, while the control group followed the habitual diet with no additional intervention. Total appendicular skeletal muscle (TASM was assessed by dual-energy X-ray absorptiometry, while strength was measured using a handheld dynamometer at baseline and after the intervention period. The primary outcomes were the percentage of relative change in TASM and strength.Results: The percentage of relative change in TASM was not significant between the groups after the intervention period. Muscle strength improved in the intervention group, but showed only a tendency towards significance (P = 0.06. Secondary analysis showed that the men in the intervention group gained 270 g in TASM compared to those in the control group, and improved their fasting insulin levels (P = 0.05, muscle strength, lean body mass in the arms, and body weight variables.Conclusion: The results of this study indicate that a nutritional intervention using a high-quality protein food, specifically ricotta cheese, in order to increase the amount of protein intake might not

  5. Effect of Body Mass Index on Postural Balance and Muscle Strength in Children Aged 8-10 years

    Lucky Prasetiowati

    2017-04-01

    Full Text Available Background:Childhood overweight and obesity, which are considered as global epidemic, can be assessed using Body Mass Index (BMI. BMI difference can lead to anatomic changes due to an increased body load. This increase might also affect motor performance, including changes in postural balance and muscle strength. Aims and Objectives: to explain the influence of BMI on postural balance and lower limb muscle strength and to assess the correlation between those two variables in children aged 8-10 years. Material and methods:The sample consisted of 63 children aged 8-10 years, which were divided in 3 groups: BMI-normal, BMI-overweight, and BMI-obese. The postural balance was assessed using single leg balance test on MatScan and the Center Of Pressure (COP area was recorded. Isometric muscle strength of hip extensor and knee extensor were measured using a hand-held dynamometer. Results: Obese children had significantly largerCOP area than overweight (p = 0.004 and normal weight children (p = 0.000.There were no significant differences in hip extensor muscle strength between obese children with overweight and normal weight children (p=0.527. The absolute knee extensor muscle strength in obese group was significantly higher than the overweight and normal group (p = 0.003. However the relative muscle strength of lower limb for obese children was significantly lower than for normal weight. There was no significant correlation between absolute hip extensor and knee extensor muscles strength with COP area. Conclusion: Obese children have decreased postural balance and increased absolute knee extensormuscle strength significantly when compared to overweight and normal children. There is no significant correlation between postural balance and muscle strength.

  6. Low relative skeletal muscle mass (sarcopenia) in older persons is associated with functional impairment and physical disability.

    Janssen, Ian; Heymsfield, Steven B; Ross, Robert

    2002-05-01

    To establish the prevalence of sarcopenia in older Americans and to test the hypothesis that sarcopenia is related to functional impairment and physical disability in older persons. Cross-sectional survey. Nationally representative cross-sectional survey using data from the Third National Health and Nutrition Examination Survey (NHANES III). Fourteen thousand eight hundred eighteen adult NHANES III participants aged 18 and older. The presence of sarcopenia and the relationship between sarcopenia and functional impairment and disability were examined in 4,504 adults aged 60 and older. Skeletal muscle mass was estimated from bioimpedance analysis measurements and expressed as skeletal muscle mass index (SMI = skeletal muscle mass/body mass x 100). Subjects were considered to have a normal SMI if their SMI was greater than -one standard deviation above the sex-specific mean for young adults (aged 18-39). Class I sarcopenia was considered present in subjects whose SMI was within -one to -two standard deviations of young adult values, and class II sarcopenia was present in subjects whose SMI was below -two standard deviations of young adult values. The prevalence of class I and class II sarcopenia increased from the third to sixth decades but remained relatively constant thereafter. The prevalence of class I (59% vs 45%) and class II (10% vs 7%) sarcopenia was greater in the older (> or = 60 years) women than in the older men (P normal SMI, respectively. Some of the associations between class II sarcopenia and functional impairment remained significant after adjustment for age, race, body mass index, health behaviors, and comorbidity. Reduced relative skeletal muscle mass in older Americans is a common occurrence that is significantly and independently associated with functional impairment and disability, particularly in older women. These observations provide strong support for the prevailing view that sarcopenia may be an important and potentially reversible cause of

  7. Effect of restriction vegan diet's on muscle mass, oxidative status, and myocytes differentiation: A pilot study.

    Vanacore, Daniela; Messina, Giovanni; Lama, Stefania; Bitti, Giuseppe; Ambrosio, Pasqualina; Tenore, Giancarlo; Messina, Antonietta; Monda, Vincenzo; Zappavigna, Silvia; Boccellino, Mariarosaria; Novellino, Ettore; Monda, Marcellino; Stiuso, Paola

    2018-01-10

    This study was conceived to evaluate the effects of three different diets on body composition, metabolic parameters, and serum oxidative status. We enrolled three groups of healthy men (omnivores, vegetarians, and vegans) with similar age, weight and BMI, and we observed a significant decrease in muscle mass index and lean body mass in vegan compared to vegetarian and omnivore groups, and higher serum homocysteine levels in vegetarians and vegans compared to omnivores. We studied whether serum from omnivore, vegetarian, and vegan subjects affected oxidative stress, growth and differentiation of both cardiomyoblast cell line H9c2 and H-H9c2 (H9c2 treated with H 2 O 2 to induce oxidative damage). We demonstrated that vegan sera treatment of both H9c2 and H-H9c2 cells induced an increase of TBARS values and cell death and a decrease of free NO 2- compared to vegetarian and omnivorous sera. Afterwards, we investigated the protective effects of vegan, vegetarian, and omnivore sera on the morphological changes induced by H 2 O 2 in H9c2 cell line. We showed that the omnivorous sera had major antioxidant and differentiation properties compared to vegetarian and vegan sera. Finally, we evaluated the influence of the three different groups of sera on MAPKs pathway and our data suggested that ERK expression increased in H-H9c2 cells treated with vegetarian and vegan sera and could promote cell death. The results obtained in this study demonstrated that restrictive vegan diet could not prevent the onset of metabolic and cardiovascular diseases nor protect by oxidative damage. © 2018 Wiley Periodicals, Inc.

  8. Predicting skeletal muscle mass from dual-energy X-ray absorptiometry in Japanese prepubertal children.

    Midorikawa, T; Ohta, M; Hikihara, Y; Torii, S; Sakamoto, S

    2017-10-01

    We aimed to develop regression-based prediction equations for estimating total and regional skeletal muscle mass (SMM) from measurements of lean soft tissue mass (LSTM) using dual-energy X-ray absorptiometry (DXA) and investigate the validity of these equations. In total, 144 healthy Japanese prepubertal children aged 6-12 years were divided into 2 groups: the model development group (62 boys and 38 girls) and the validation group (26 boys and 18 girls). Contiguous MRI images with a 1-cm slice thickness were obtained from the first cervical vertebra to the ankle joints as reference data. The SMM was calculated from the summation of the digitized cross-sectional areas. Total and regional LSTM was measured using DXA. Strong significant correlations were observed between the site-matched SMM (total, arms, trunk and legs) measured by MRI and the LSTM obtained by DXA in the model development group for both boys and girls (R 2 adj =0.86-0.97, Pprediction equations were applied to the validation group, the measured total (boys 9.47±2.21 kg; girls 8.18±2.62 kg) and regional SMM were very similar to the predicted values for both boys (total SMM 9.40±2.39 kg) and girls (total SMM 8.17±2.57 kg). The results of the Bland-Altman analysis for the validation group did not indicate any bias for either boys or girls with the exception of the arm region for the girls. These results suggest that the DXA-derived prediction equations are precise and accurate for the estimation of total and regional SMM in Japanese prepubertal boys and girls.

  9. Age- and gender-dependent values of skeletal muscle mass in healthy children and adolescents.

    Webber, Colin E; Barr, Ronald D

    2012-03-01

    Skeletal muscle mass (SMM) can be extracted from whole-body scans obtained by X-ray-based dual-photon absorptiometry (DXA). There is a need to establish expected age-dependent values for children and adolescents. Appendicular lean tissue mass (ALM) was extracted from whole-body DXA scans in 140 healthy children and adolescents (68 females and 72 males). Whole-body SMM was calculated from ALM using equations developed by Kim et al. (Am J Clin Nutr 84:1014-1020, 2006). Age-dependent patterns of increase in SMM were derived by fitting SMM values to equations that consisted of the sum of two logistic expressions, one accounting for SMM changes during growth and the other for SMM changes during puberty. Normal ranges were defined so that 95% of the SMM values were included. The reproducibility of SMM measurements was obtained from whole-body DXA scans repeated on three occasions in each of a separate group of 32 normal children with repositioning between scans. Normal ranges are presented as equations describing the age-dependent pattern of increase in SMM as well as population standard deviations that increased steadily with age. For 15 children below age 10, SMM reproducibility (95% CI) was 149 g (119-199 g) while for 17 children and adolescents over age 10, reproducibility was 170 g (138-223 g). DXA-based measurements of SMM in children and adolescents are reproducible and can be expressed in terms of age-dependent Z scores.

  10. Pre-hospital dietary intake correlates with muscle mass at the time of fracture in older hip fractured patients

    Riccardo eCalvani

    2014-11-01

    Full Text Available Background. Failure to meet an adequate dietary intake is involved in the pathogenesis of sarcopenia and osteoporosis, which in turn increase the risk for falls and fractures, respectively. Older people with hip fracture are often protein-malnourished at hospitalization. Whether low protein-energy intake is associated with muscle atrophy in hip fractured patients is presently unknown. This information is necessary for the development of novel strategies to manage this especially vulnerable patient population. The aim of this study was therefore to explore the relationship between dietary intake and muscle mass in older hip fractured patients.Methods. Analyses were conducted in hip fractured elderly admitted to an orthopedic and trauma surgery ward (University Hospital. Muscle mass was estimated by bioelectrical impedance analysis within 24 h from admission. Dietary information was collected via 24-h dietary recall and nutrient intakes calculated by a nutrition software.Results. Among 62 hip fractured patients (mean age 84.6±7.6 years, 84% women, the average energy intake was 929.2±170.3 Kcal/day, with higher values reported by men (1.046.8±231.4 Kcal/day relative to women (906.5±148.3 Kcal/day; p=0.01. Absolute and normalized protein intake was 50.0±13.5 g/day and 0.88±0.27 g/kg (body weight/day, respectively, with no gender differences. A positive correlation was determined between total energy intake and muscle mass (r=0.384; p=0.003. Similarly, protein and leucine consumption was positively correlated with muscle mass (r=0.367 and 0.311, respectively; p=0.005 for both.Conclusions. A low intake of calories, protein and leucine is associated with reduced muscle mass in hip fractured elderly. Given the relevance of sarcopenia as a risk factor for adverse outcomes in this patient population, our findings highlight the importance of a comprehensive dietary assessment for the detection of nutritional deficits predisposing to or aggravating

  11. Effects of Insect Protein Supplementation during Resistance Training on Changes in Muscle Mass and Strength in Young Men

    Mathias T. Vangsoe

    2018-03-01

    Full Text Available During prolonged resistance training, protein supplementation is known to promote morphological changes; however, no previous training studies have tested the effect of insect protein isolate in a human trial. The aim of this study was to investigate the potential effect of insect protein as a dietary supplement to increase muscle hypertrophy and strength gains during prolonged resistance training in young men. Eighteen healthy young men performed resistance training four day/week for eight weeks. Subjects were block randomized into two groups consuming either an insect protein isolate or isocaloric carbohydrate supplementation within 1 h after training and pre-sleep on training days. Strength and body composition were measured before and after intervention to detect adaptions to the resistance training. Three-day weighed dietary records were completed before and during intervention. Fat- and bone- free mass (FBFM improved significantly in both groups (Mean (95% confidence interval (CI, control group (Con: (2.5 kg (1.5, 3.5 p < 0.01, protein group (Pro: (2.7 kg (1.6, 3.8 p < 0.01 from pre- to post-. Leg and bench press one repetition maximum (1 RM improved by Con: (42.0 kg (32.0, 52.0 p < 0.01 and (13.8 kg (10.3, 17.2 p < 0.01, Pro: (36.6 kg (27.3, 45.8 p < 0.01 and (8.1 kg (4.5, 11.8 p < 0.01, respectively. No significant differences in body composition and muscle strength improvements were found between groups. In young healthy men, insect protein supplementation did not improve adaptations to eight weeks of resistance training in comparison to carbohydrate supplementation. A high habitual protein intake in both Con and Pro may partly explain our observation of no superior effect of insect protein supplementation.

  12. Aerobic characteristics of red kangaroo skeletal muscles: is a high aerobic capacity matched by muscle mitochondrial and capillary morphology as in placental mammals?

    Dawson, Terence J; Mifsud, Brock; Raad, Matthew C; Webster, Koa N

    2004-07-01

    Marsupials and placentals together comprise the Theria, the advanced mammals, but they have had long independent evolutionary histories, with the last common ancestor occurring more than 125 million years ago. Although in the past the marsupials were considered to be metabolically 'primitive', the red kangaroo Macropus rufus has been reported to have an aerobic capacity (VO2max) comparable to that of the most 'athletic' of placentals such as dogs. However, kangaroos travel at moderate speeds with lower relative cost than quadrupedal placentals. Given the long independent evolution of the two therian groups, and their unusual locomotor energetics, do kangaroos achieve their high aerobic capacity using the same structural and functional mechanisms used by (athletic) placentals? Red kangaroo skeletal muscle morphometry matched closely the general aerobic characteristics of placental mammals. The relationship between total mitochondrial volume in skeletal muscle and VO2max during exercise was identical to that in quadrupedal placentals, and differed from that in bipedal humans. As for placentals generally, red kangaroo mitochondrial oxygen consumption at VO2max was 4.7 ml O2 min(-1) ml(-1) of mitochondria. Also, the inner mitochondrial membrane densities were 35.8 +/- 0.7 m2 ml(-1) of mitochondria, which is the same as for placental mammals, and the same pattern of similarity was seen for capillary densities and volumes. The overall data for kangaroos was equivalent to that seen in athletic placentals such as dogs and pronghorns. Total skeletal muscle mass was high, being around 50% of body mass, and was concentrated around the pelvis and lower back. The majority of the muscles sampled had relatively high mitochondrial volume densities, in the range 8.8-10.6% in the major locomotor muscles. Again, capillary densities and capillary blood volumes followed the pattern seen for mitochondria. Our results indicate that the red kangaroo, despite its locomotion and extreme

  13. Alternate-Day High-Fat Diet Induces an Increase in Mitochondrial Enzyme Activities and Protein Content in Rat Skeletal Muscle.

    Li, Xi; Higashida, Kazuhiko; Kawamura, Takuji; Higuchi, Mitsuru

    2016-04-06

    Long-term high-fat diet increases muscle mitochondrial enzyme activity and endurance performance. However, excessive calorie intake causes intra-abdominal fat accumulation and metabolic syndrome. The purpose of this study was to investigate the effect of an alternating day high-fat diet on muscle mitochondrial enzyme activities, protein content, and intra-abdominal fat mass in rats. Male Wistar rats were given a standard chow diet (CON), high-fat diet (HFD), or alternate-day high-fat diet (ALT) for 4 weeks. Rats in the ALT group were fed a high-fat diet and standard chow every other day for 4 weeks. After the dietary intervention, mitochondrial enzyme activities and protein content in skeletal muscle were measured. Although body weight did not differ among groups, the epididymal fat mass in the HFD group was higher than those of the CON and ALT groups. Citrate synthase and beta-hydroxyacyl CoA dehydrogenase activities in the plantaris muscle of rats in HFD and ALT were significantly higher than that in CON rats, whereas there was no difference between HFD and ALT groups. No significant difference was observed in muscle glycogen concentration or glucose transporter-4 protein content among the three groups. These results suggest that an alternate-day high-fat diet induces increases in mitochondrial enzyme activities and protein content in rat skeletal muscle without intra-abdominal fat accumulation.

  14. High performance electrochemical and electrothermal artificial muscles from twist-spun carbon nanotube yarn

    Lee, Jae Ah; Baughman, Ray H.; Kim, Seon Jeong

    2015-04-01

    High performance torsional and tensile artificial muscles are described, which utilize thermally- or electrochemically-induced volume changes of twist-spun, guest-filled, carbon nanotube (CNT) yarns. These yarns were prepared by incorporating twist in carbon nanotube sheets drawn from spinnable CNT forests. Inserting high twist into the CNT yarn results in yarn coiling, which can dramatically amplify tensile stroke and work capabilities compared with that for the non-coiled twisted yarn. When electrochemically driven in a liquid electrolyte, these artificial muscles can generate a torsional rotation per muscle length that is over 1000 times higher than for previously reported torsional muscles. All-solid-state torsional electrochemical yarn muscles have provided a large torsional muscle stroke (53° per mm of yarn length) and a tensile stroke of up to 1.3% when lifting loads that are ~25 times heavier than can be lifted by the same diameter human skeletal muscle. Over a million torsional and tensile actuation cycles have been demonstrated for thermally powered CNT hybrid yarns muscles filled with paraffin wax, wherein a muscle spins a rotor at an average 11,500 revolutions/minute or delivers 3% tensile contraction at 1200 cycles/minute. At lower actuation rates, these thermally powered muscles provide tensile strokes of over 10%.

  15. Skeletal muscle mass and body fat in relation to successful ageing of older adults: The multi-national MEDIS study.

    Tyrovolas, Stefanos; Haro, Josep-Maria; Mariolis, Anargiros; Piscopo, Suzanne; Valacchi, Giuseppe; Bountziouka, Vassiliki; Anastasiou, Foteini; Zeimbekis, Akis; Tyrovola, Dimitra; Foscolou, Alexandra; Gotsis, Efthimios; Metallinos, George; Tur, Josep-Antoni; Matalas, Antonia; Lionis, Christos; Polychronopoulos, Evangelos; Panagiotakos, Demosthenes

    2016-01-01

    The determinants that promote successful ageing still remain unknown. The aim of the present work was to evaluate the role of skeletal muscle mass and body fat percentage (BF%), in the level of successful ageing. during 2005-2011, 2663 older (aged 65-100 years) from 21 Mediterranean islands and the rural Mani region (Peloponnesus) of Greece were voluntarily enrolled in the study. Appendicular skeletal muscle mass (ASM), skeletal muscle mass index (SMI) and BF% were calculated using population formulas. Dietary habits, energy intake, expenditure and energy balance were derived throughout standard procedures. A successful ageing index ranging from 0 to 10 was used. The mean ASM mass was 24±6.0kg, the SMI was 0.84±0.21 and the BF% was 44%. Females had lower SMI and higher BF% in comparison with males, respectively [(SMI: 0.66±0.09 vs. 1.03±0.11; BF%: 51% vs. 34%, (pageing, while changes in BF% [b-coefficient (95% CI): -0.04 (-0.05 to -0.03)] were inversely associated with successful ageing. Results from sensitivity analysis showed that the effects of variations on body composition were consistent, less pronounced in the positive energy balance group and more pronounced among the oldest old. Body composition changes seem to be associated with lower quality of life in the older adults, as measured through successful ageing. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  16. The effect of low extremity plyometric training on back muscle power of high school throwing event athletes.

    Park, Gi Duck; Lee, Joong Chul; Lee, Juri

    2014-01-01

    [Purpose] The physical strength elements required for athletic throwing events include muscle strength, swiftness, agility, speed, flexibility, and physical balance. Although plyometric training and weight training are implemented as representative training methods for improving swiftness and agility, most studies of it have been conducted with players of other sports. [Subjects] The study subjects were 10 throwing event athletes attending K physical education high school. The subjects were randomly assigned to a control group of five subjects and an experimental group of five subjects. To analyze the body composition, an Inbody 3.0 instrument (Biospace, Korea) was used as experimental equipment to measure heights, weight, body fat percentages, and muscle masses and a Biodex system 4.0 (BIODEX, USA) was used to measure isokinetic muscle-joint and lumbar muscle strengths. The plyometric training consisted of 15 techniques out of the training methods introduced in the 'Power up plyometric training'. The plyometric program was implemented without any training load three times per week during daybreak exercises for the experimental group. The number of times and the number of sets were changed over time as follows: three sets of 10 times in the 1st -4th weeks, three sets of 15 times in the 5th-8th weeks, and five sets of 15 times in the 9th-12th weeks. [Results] According to the ANCOVA results of lumbar extensor muscle strength at 60°/sec, the overall reliability of the model was significant. According to the ANCOVA results of lumbar flexor muscle strength at 60°/sec, the overall reliability of the model was significant. [Conclusion] Plyometric training positively affected high school throwing event athletes. To summarize the study findings, the application of plyometric training with high intensity and loads improved the results of athletes who perform highly intensive exercises at normal times.

  17. Low intensity vibration of ankle muscles improves balance in elderly persons at high risk of falling

    Toosizadeh, Nima; Mohler, Jane

    2018-01-01

    In our study we examined postural performance of young healthy persons (HY), elderly healthy persons (HE), and elderly persons at high risk of falling (FR). Anterio-posterior (AP) and medio-lateral (ML) ankle and hip angular deviations, as well as linear displacements of the center of mass (COM) were assessed in persons standing with eyes either open or closed, while none, and 40 and 30 Hz vibrations were applied bilaterally to the ankle muscle gastrocnemius. During quiet standing with eyes open, balance parameters in FR group differed from those in healthy groups. ML ankle and hip angular deviations, as well as COM linear displacements were noticeably larger in FR group. During quiet standing with eyes closed, all balance parameters in participants of all groups had a clear trend to increase. During standing with eyes open, 40 Hz vibration increased all but one balance parameter within HY group, ankle angular deviations in HE group, but none in FR group. In response to 30 Hz vibration, only ankle angular deviations and COM linear displacements increased in HY group. There were no changes in both elderly groups. During standing with eyes closed, 40 and 30 Hz vibrations did not produce consistent changes in balance parameters in HY and HE groups. In FR persons, 40 Hz vibration did not change balance parameters. However, in FR groups, 30 Hz vibration decreased ankle and hip angular deviations, and COM linear displacements. The major result of the study is a finding that low intensity vibration of ankle muscles makes balance better in elderly persons at high risk of falling. This result is clinically relevant because it suggests that applying mild vibration to ankle muscles while standing and walking might benefit elderly persons, improving their postural performance and reducing a risk of unexpected falls. PMID:29579098

  18. Slow movement resistance training using body weight improves muscle mass in the elderly: A randomized controlled trial.

    Tsuzuku, S; Kajioka, T; Sakakibara, H; Shimaoka, K

    2018-04-01

    To examine the effect of a 12-week slow movement resistance training using body weight as a load (SRT-BW) on muscle mass, strength, and fat distribution in healthy elderly people. Fifty-three men and 35 women aged 70 years old or older without experience in resistance training participated, and they were randomly assigned to a SRT-BW group or control group. The control group did not receive any intervention, but participants in this group underwent a repeat measurement 12 weeks later. The SRT-BW program consisted of 3 different exercises (squat, tabletop push-up, and sit-up), which were designed to stimulate anterior major muscles. Initially, these exercises were performed by 2 sets of 10 repetitions, and subsequently, the number of repetitions was increased progressively by 2 repetitions every 4 weeks. Participants were instructed to perform each eccentric and concentric phase of movement slowly (spending 4 seconds on each movement), covering the full range of motion. We evaluated muscle mass, strength, and fat distribution at baseline and after 12 weeks of training. Changes over 12 weeks were significantly greater in the SRT-BW group than in the control group, with a decrease in waist circumference, hip circumference, and abdominal preperitoneal and subcutaneous fat thickness, and an increase in thigh muscle thickness, knee extension strength, and hip flexion strength. In conclusion, relatively short-term SRT-BW was effective in improving muscle mass, strength, and fat distribution in healthy elderly people. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  19. Nutritional Strategies for the Preservation of Fat Free Mass at High Altitude

    Stacie L. Wing-Gaia

    2014-02-01

    Full Text Available Exposure to extreme altitude presents many physiological challenges. In addition to impaired physical and cognitive function, energy imbalance invariably occurs resulting in weight loss and body composition changes. Weight loss, and in particular, loss of fat free mass, combined with the inherent risks associated with extreme environments presents potential performance, safety, and health risks for those working, recreating, or conducting military operations at extreme altitude. In this review, contributors to muscle wasting at altitude are highlighted with special emphasis on protein turnover. The article will conclude with nutritional strategies that may potentially attenuate loss of fat free mass during high altitude exposure.

  20. Prolonged Adaptation to a Low or High Protein Diet Does Not Modulate Basal Muscle Protein Synthesis Rates - A Substudy.

    Hursel, Rick; Martens, Eveline A P; Gonnissen, Hanne K J; Hamer, Henrike M; Senden, Joan M G; van Loon, Luc J C; Westerterp-Plantenga, Margriet S

    2015-01-01

    Based on controlled 36 h experiments a higher dietary protein intake causes a positive protein balance and a negative fat balance. A positive net protein balance may support fat free mass accrual. However, few data are available on the impact of more prolonged changes in habitual protein intake on whole-body protein metabolism and basal muscle protein synthesis rates. To assess changes in whole-body protein turnover and basal muscle protein synthesis rates following 12 weeks of adaptation to a low versus high dietary protein intake. A randomized parallel study was performed in 40 subjects who followed either a high protein (2.4 g protein/kg/d) or low protein (0.4 g protein/kg/d) energy-balanced diet (30/35/35% or 5/60/35% energy from protein/carbohydrate/fat) for a period of 12 weeks. A subgroup of 7 men and 8 women (body mass index: 22.8±2.3 kg/m2, age: 24.3±4.9 y) were selected to evaluate the impact of prolonged adaptation to either a high or low protein intake on whole body protein metabolism and basal muscle protein synthesis rates. After the diet, subjects received continuous infusions with L-[ring-2H5]phenylalanine and L-[ring-2H2]tyrosine in an overnight fasted state, with blood samples and muscle biopsies being collected to assess post-absorptive whole-body protein turnover and muscle protein synthesis rates in vivo in humans. After 12 weeks of intervention, whole-body protein balance in the fasted state was more negative in the high protein treatment when compared with the low protein treatment (-4.1±0.5 vs -2.7±0.6 μmol phenylalanine/kg/h;Pprotein breakdown (43.0±4.4 vs 37.8±3.8 μmol phenylalanine/kg/h;Psynthesis (38.9±4.2 vs 35.1±3.6 μmol phenylalanine/kg/h;Pprotein group. Basal muscle protein synthesis rates were maintained on a low vs high protein diet (0.042±0.01 vs 0.045±0.01%/h;P = 0.620). In the overnight fasted state, adaptation to a low-protein intake (0.4 g/kg/d) does not result in a more negative whole-body protein balance and

  1. Propeptide-mediated inhibition of myostatin increases muscle mass through inhibiting proteolytic pathways in aged mice.

    Collins-Hooper, Henry; Sartori, Roberta; Macharia, Raymond; Visanuvimol, Korntip; Foster, Keith; Matsakas, Antonios; Flasskamp, Hannah; Ray, Steve; Dash, Philip R; Sandri, Marco; Patel, Ketan

    2014-09-01

    Mammalian aging is accompanied by a progressive loss of skeletal muscle, a process called sarcopenia. Myostatin, a secreted member of the transforming growth factor-β family of signaling molecules, has been shown to be a potent inhibitor of muscle growth. Here, we examined whether muscle growth could be promoted in aged animals by antagonizing the activity of myostatin through the neutralizing activity of the myostatin propeptide. We show that a single injection of an AAV8 virus expressing the myostatin propeptide induced an increase in whole body weights and all muscles examined within 7 weeks of treatment. Our cellular studies demonstrate that muscle enlargement was due to selective fiber type hypertrophy, which was accompanied by a shift toward a glycolytic phenotype. Our molecular investigations elucidate the mechanism underpinning muscle hypertrophy by showing a decrease in the expression of key genes that control ubiquitin-mediated protein breakdown. Most importantly, we show that the hypertrophic muscle that develops as a consequence of myostatin propeptide in aged mice has normal contractile properties. We suggest that attenuating myostatin signaling could be a very attractive strategy to halt and possibly reverse age-related muscle loss. © The Author 2014. Published by Oxford University Press on behalf of The Gerontological Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  2. Influence of step-height and body mass on gastrocnemius muscle fascicle behavior during stair ascent.

    Spanjaard, M.; Reeves, N.D.; van Dieen, J.H.; Baltzopoulos, V.; Maganaris, C.N.

    2008-01-01

    To better understand the role of the ankle plantar flexor muscles in stair negotiation, we examined the effects of manipulation of kinematic and kinetic constraints on the behavior of the gastrocnemius medialis (GM) muscle during stair ascent. Ten subjects ascended a four-step staircase at four

  3. The high aerobic capacity of a small, marsupial rat-kangaroo (Bettongia penicillata) is matched by the mitochondrial and capillary morphology of its skeletal muscles.

    Webster, Koa N; Dawson, Terence J

    2012-09-15

    We examined the structure-function relationships that underlie the aerobic capacities of marsupial mammals that hop. Marsupials have relatively low basal metabolic rates (BMR) and historically were seen as 'low energy' mammals. However, the red kangaroo, Macropus rufus (family Macropodidae), has aerobic capacities equivalent to athletic placentals. It has an extreme aerobic scope (fAS) and its large locomotor muscles feature high mitochondrial and capillary volumes. M. rufus belongs to a modern group of kangaroos and its high fAS is not general for marsupials. However, other hopping marsupials may have elevated aerobic capacities. Bettongia penicillata, a rat-kangaroo (family Potoroidae), is a small (1 kg), active hopper whose fAS is somewhat elevated. We examined the oxygen delivery system in its muscles to ascertain links with hopping. An elevated fAS of 23 provided a relatively high maximal aerobic oxygen consumption ( ) in B. penicillata; associated with this is a skeletal muscle mass of 44% of body mass. Ten muscles were sampled to estimate the total mitochondrial and capillary volume of the locomotor muscles. Values in B. penicillata were similar to those in M. rufus and in athletic placentals. This small hopper had high muscle mitochondrial volume densities (7.1-11.9%) and both a large total capillary volume (6 ml kg(-1) body mass) and total capillary erythrocyte volume (3.2 ml kg(-1)). Apparently, a considerable aerobic capacity is required to achieve the benefits of the extended stride in fast hopping. Of note, the ratio of to total muscle mitochondrial volume in B. penicillata was 4.9 ml O(2) min(-1) ml(-1). Similar values occur in M. rufus and also placental mammals generally, not only athletic species. If such relationships occur in other marsupials, a fundamental structure-function relationship for oxygen delivery to muscles likely originated with or before the earliest mammals.

  4. Increase in relative skeletal muscle mass over time and its inverse association with metabolic syndrome development: a 7-year retrospective cohort study.

    Kim, Gyuri; Lee, Seung-Eun; Jun, Ji Eun; Lee, You-Bin; Ahn, Jiyeon; Bae, Ji Cheol; Jin, Sang-Man; Hur, Kyu Yeon; Jee, Jae Hwan; Lee, Moon-Kyu; Kim, Jae Hyeon

    2018-02-05

    Skeletal muscle mass was negatively associated with metabolic syndrome prevalence in previous cross-sectional studies. The aim of this study was to investigate the impact of baseline skeletal muscle mass and changes in skeletal muscle mass over time on the development of metabolic syndrome in a large population-based 7-year cohort study. A total of 14,830 and 11,639 individuals who underwent health examinations at the Health Promotion Center at Samsung Medical Center, Seoul, Korea were included in the analyses of baseline skeletal muscle mass and those changes from baseline over 1 year, respectively. Skeletal muscle mass was estimated by bioelectrical impedance analysis and was presented as a skeletal muscle mass index (SMI), a body weight-adjusted appendicular skeletal muscle mass value. Using Cox regression models, hazard ratio for developing metabolic syndrome associated with SMI values at baseline or changes of SMI over a year was analyzed. During 7 years of follow-up, 20.1% of subjects developed metabolic syndrome. Compared to the lowest sex-specific SMI tertile at baseline, the highest sex-specific SMI tertile showed a significant inverse association with metabolic syndrome risk (adjusted hazard ratio [AHR] = 0.61, 95% confidence interval [CI] 0.54-0.68). Furthermore, compared with SMI changes metabolic syndrome development were 0.87 (95% CI 0.78-0.97) for 0-1% changes and 0.67 (0.56-0.79) for > 1% changes in SMI over 1 year after additionally adjusting for baseline SMI and glycometabolic parameters. An increase in relative skeletal muscle mass over time has a potential preventive effect on developing metabolic syndrome, independently of baseline skeletal muscle mass and glycometabolic parameters.

  5. Clinical effectiveness of protein and amino acid supplementation on building muscle mass in elderly people: a meta-analysis.

    Zhe-rong Xu

    Full Text Available A major reason for the loss of mobility in elderly people is the gradual loss of lean body mass known as sarcopenia. Sarcopenia is associated with a lower quality of life and higher healthcare costs. The benefit of strategies that include nutritional intervention, timing of intervention, and physical exercise to improve muscle loss unclear as finding from studies investigating this issue have been inconsistent. We have performed a systematic review and meta-analysis to assess the ability of protein or amino acid supplementation to augment lean body mass or strength of leg muscles in elderly patients.Nine studies met the inclusion criteria of being a prospective comparative study or randomized controlled trial (RCT that compared the efficacy of an amino acid or protein supplement intervention with that of a placebo in elderly people (≥ 65 years for the improvement of lean body mass (LBM, leg muscle strength or reduction associated with sarcopenia.The overall difference in mean change from baseline to the end of study in LBM between the treatment and placebo groups was 0.34 kg which was not significant (P = 0.386. The overall differences in mean change from baseline in double leg press and leg extension were 2.14 kg (P = 0.748 and 2.28 kg (P = 0.265, respectively, between the treatment group and the placebo group.These results indicate that amino acid/protein supplements did not increase lean body mass gain and muscle strength significantly more than placebo in a diverse elderly population.

  6. Effect of strength training and short-term detraining on muscle mass in women aged over 50 years old

    Maryam Delshad

    2013-01-01

    Full Text Available Background: The loss of muscle mass is associated with aging. The aim of this study was to determine the effects of resistance training and detraining on muscle mass in elderly women. Methods: Twenty post-menopausal women aged ≥50 years old were enrolled. Matching for age, they were randomly assigned into control and resistance training group (RT. The intervention consisted of three sets of 10 repetitions for 10 movements with Thera-Band tubing (based on 80-100% 10-RM, three times a week, for 12 weeks and thereafter, four weeks detraining. Skinfold thickness was determined by caliper. Percentage of body fat was estimated from skinfold thickness (triceps and subscapular by McArdle method. Fat mass (FM and fat-free mass (FFM were calculated. Range of motion for trunk flexion and extension was determined. Results: During 12 weeks of intervention, significant increases were observed in 1-RM of biceps curl, FFM, trunk flexion and extension and significant decreases during four weeks detraining in RT group. The RT group demonstrated significant decreases during resistance training and increases during detraining in skinfold thickness. FFM, trunk flexion, and extension decreased and skinfold thickness, %FM, and weight of body fat increased in the control group (P < 0.05. Conclusions: Resistance training with Thera-Band enhanced strength and muscle endurance in elderly women and a 4-week detraining period had an adverse effect on muscle power. This suggests that a strength training program is an effective intervention to prevent functional reductions, and can contribute to improve neuromuscular function in older adults.

  7. Muscle mass and physical recovery in ICU: innovations for targeting of nutrition and exercise.

    Wischmeyer, Paul E; Puthucheary, Zudin; San Millán, Iñigo; Butz, Daniel; Grocott, Michael P W

    2017-08-01

    We have significantly improved hospital mortality from sepsis and critical illness in last 10 years; however, over this same period we have tripled the number of 'ICU survivors' going to rehabilitation. Furthermore, as up to half the deaths in the first year following ICU admission occur post-ICU discharge, it is unclear how many of these patients ever returned home or a meaningful quality of life. For those who do survive, recent data reveals many 'ICU survivors' will suffer significant functional impairment or post-ICU syndrome (PICS). Thus, new innovative metabolic and exercise interventions to address PICS are urgently needed. These should focus on optimal nutrition and lean body mass (LBM) assessment, targeted nutrition delivery, anabolic/anticatabolic strategies, and utilization of personalized exercise intervention techniques, such as utilized by elite athletes to optimize preparation and recovery from critical care. New data for novel LBM analysis technique such as computerized tomography scan and ultrasound analysis of LBM are available showing objective measures of LBM now becoming more practical for predicting metabolic reserve and effectiveness of nutrition/exercise interventions. 13C-Breath testing is a novel technique under study to predict infection earlier and predict over-feeding and under-feeding to target nutrition delivery. New technologies utilized routinely by athletes such as muscle glycogen ultrasound also show promise. Finally, the role of personalized cardiopulmonary exercise testing to target preoperative exercise optimization and post-ICU recovery are becoming reality. New innovative techniques are demonstrating promise to target recovery from PICS utilizing a combination of objective LBM and metabolic assessment, targeted nutrition interventions, personalized exercise interventions for prehabilitation and post-ICU recovery. These interventions should provide hope that we will soon begin to create more 'survivors' and fewer victim's post

  8. Scapular muscle activity from selected strengthening exercises performed at low and high intensity

    Andersen, Christoffer H; Zebis, Mette K; Saervoll, Charlotte

    2012-01-01

    A balanced level of muscle strength between the different parts of the scapular muscles is important to optimize performance and prevent injuries in athletes. Emerging evidence suggests that many athletes lack balanced strength in the scapular muscles. Evidence based recommendations are important...... for proper exercise prescription. This study determines scapular muscle activity during strengthening exercises for scapular muscles performed at low and high intensities (Borg-CR10 level 3 and 8). Surface electromyography (EMG) from selected scapular muscles was recorded during seven strengthening exercises...... and expressed as a percentage of the maximal EMG. Seventeen women (aged 24-55 years) without serious disorders participated. Several of the investigated exercises - press-up, prone flexion, one-arm row and prone abduction at Borg 3 and press-up, push-up plus and one-arm row at Borg 8 - predominantly activated...

  9. Type VI collagen turnover-related peptides-novel serological biomarkers of muscle mass and anabolic response to loading in young men.

    Nedergaard, Anders; Sun, Shu; Karsdal, Morten A; Henriksen, Kim; Kjær, Michael; Lou, Yunyun; He, Yi; Zheng, Qinlong; Suetta, Charlotte

    2013-12-01

    Immobilization-induced loss of muscle mass is a complex phenomenon with several parallels to sarcopenic and cachectic muscle loss. Muscle is a large organ with a protein turnover that is orders of magnitude larger than most other tissues. Thus, we hypothesize that muscle loss and regain is reflected by peptide biomarkers derived from type VI collagen processing released in the circulation. In order to test this hypothesis, we set out to develop an ELISA assay against an type VI collagen N-terminal globular domain epitope (IC6) and measured the levels of IC6 and an MMP-generated degradation fragment of collagen 6, (C6M) in a human immobilization-remobilization study setup with young (n = 11) and old (n = 9) men. They were subjected to 2 weeks of unilateral lower limb immobilization followed by 4 weeks of remobilization including thrice weekly resistance training, using the contralateral leg as internal controls. Subjects were sampled for strength, quadriceps muscle volume and blood at baseline (PRE), post-immobilization (2W), and post-remobilization (4W). Blood were subsequently analyzed for levels of the C6M and IC6 biomarkers. We subsequently tested if there was any correlation between C6M, IC6, or the C6M/IC6 ratio and muscle mass or strength at baseline. We also tested whether there was any relation between these biomarkers and changes in muscle mass or strength with immobilization or remobilization. The model produced significant loss of muscle mass and strength in the immobilized leg. This loss was bigger in young subjects than in elderly, but whereas the young recovered almost fully, the elderly had limited regrowth of muscle. We found a significant correlation between IC6 and muscle mass at baseline in young subjects (R (2) = 0.6563, p = 0.0045), but none in the elderly. We also found a significant correlation between C6M measured at the 4W time point and the change in muscle mass during remobilization, again only manifesting in the young

  10. Lean body mass and muscle function in head and neck cancer patients and healthy individuals - results from the DAHANCA 25 study

    Lønbro, Simon; Dalgas, Ulrik; Primdahl, Hanne

    2013-01-01

    Abstract Introduction. Loss of lean body mass is common following radiotherapy in patients with head and neck squamous cell carcinoma (HNSCC) and may reduce maximal muscle strength and functional performance. However, the associations between lean body mass, muscle strength and functional...... m max gait speed, 30 s chair rise, 30 s arm curl, stair climb) from HNSCC patients from the DAHANCA 25 trials and data from 24 healthy individuals were included. Results. Lean body mass and maximal muscle strength were significantly associated according to the gender and age-adjusted linear...... regression model (p regression analyses showed that HNSCC patients expressed significant lower levels of the investigated variables after radiotherapy...

  11. Assessment of muscle mass, risk of falls and fear of falling in elderly people with diabetic neuropathy

    Hudson Azevedo Pinheiro

    Full Text Available Abstract Objective : To assess muscle mass, risk of falls and fear of falling in elderly adults with diabetic neuropathy (DNP. Methods : 50 elderly patients with diabetes mellitus (DM and diabetic neuropathy (NPD participated in this study. Risk of falling was assessed using the Berg Balance Scale (BBS. Fear of falling was assessed by means of the Falls Efficacy Scale-International (FES-I. Muscle mass was assessed by tetrapolar bioimpedance analysis (BIA and Janssen's equation. Subjects were divided into two groups: one with a history of falls in the six months before study enrollment (G1 and the other without history of falls (G2. Results : There were statistically significant differences between G1 and G2 regarding lean body mass (p < 0.05, risk of falls as measured by the BBS (p < 0.01, and fear of falling as measured by the FES-I (p < 0.01. In addition, there was a significant correlation between the BBS and BIA (r = 0.45 and p < 0.01, showing that the greater the lean body mass, the lower the risk of falling. Conclusions : We found an association between lean mass, risk of falls and fear of falling in elderly adults with DNP and a history of falls from own height.

  12. The association of low muscle mass with soluble receptor for advanced glycation end products (sRAGE): The Korean Sarcopenic Obesity Study (KSOS).

    Kim, Tae Nyun; Park, Man Sik; Lee, Eun Joo; Chung, Hye Soo; Yoo, Hye Jin; Kang, Hyun Joo; Song, Wook; Baik, Sei Hyun; Choi, Kyung Mook

    2018-03-01

    Advanced glycation end products (AGEs) are accumulated with aging in various tissues of humans. The soluble receptor for AGEs (sRAGE) exerts a protective role against the development of aging-related chronic disorders by neutralizing the action of AGEs. We investigated the implication of sRAGE on low muscle mass in Asian men and women. This cross-sectional study included a 390-participant, nondiabetic subcohort recruited within the framework of the Korean Sarcopenic Obesity Study, an ongoing prospective cohort study. Low muscle mass was defined based on the distribution of appendicular skeletal muscle mass divided by body mass index, as proposed by the Foundation for the National Institutes Sarcopenia Project. Serum sRAGE levels were significantly lower in participants with low muscle mass than in participants without low muscle mass (0.76 [0.60-1.00] ng/mL vs 0.87 [0.67-1.15] ng/mL, P = .005). In age- and sex-adjusted correlation analyses, appendicular skeletal muscle mass divided by body mass index was associated with sRAGE (r = 0.109, P = .037). Furthermore, decreased circulating levels of sRAGE are independently associated with low muscle mass (odds ratio = 0.254, P = .002) after adjusting for confounding factors, including insulin resistance and inflammatory markers. The present study shows that a low circulating level of sRAGE may be an independent risk factor for the presence of low muscle mass. Copyright © 2017 John Wiley & Sons, Ltd.

  13. High-Latitude Neutral Mass Density Maxima

    Huang, C. Y.; Huang, Y.; Su, Y.-J.; Huang, T.; Sutton, E. K.

    2017-10-01

    Recent studies have reported that thermospheric effects due to solar wind driving can be observed poleward of auroral latitudes. In these papers, the measured neutral mass density perturbations appear as narrow, localized maxima in the cusp and polar cap. They conclude that Joule heating below the spacecraft is the cause of the mass density increases, which are sometimes associated with local field-aligned current structures, but not always. In this paper we investigate neutral mass densities measured by accelerometers on the CHAllenging Minisatellite Payload (CHAMP) and Gravity Recovery and Climate Experiment (GRACE) spacecraft from launch until years 2010 (CHAMP) and 2012 (GRACE), approximately 10 years of observations from each satellite. We extract local maxima in neutral mass densities over the background using a smoothing window with size of one quarter of the orbit. The maxima have been analyzed for each year and also for the duration of each set of satellite observations. We show where they occur, under what solar wind conditions, and their relation to magnetic activity. The region with the highest frequency of occurrence coincides approximately with the cusp and mantle, with little direct evidence of an auroral zone source. Our conclusions agree with the "hot polar cap" observations that have been reported and studied in the past.

  14. Metallic Muscles at Work : High Rate Actuation in Nanoporous Gold/Polyaniline Composites

    Detsi, Eric; Onck, Patrick; De Hosson, Jeff Th. M.

    Metallic muscles made of nanoporous metals suffer from serious drawbacks caused by the usage of an aqueous electrolyte for actuation. An aqueous electrolyte prohibits metallic muscles from operating in dry environments and hampers a high actuation rate due to the low ionic conductivity of

  15. Effects of high-intensity interval cycling performed after resistance training on muscle strength and hypertrophy.

    Tsitkanou, S; Spengos, K; Stasinaki, A-N; Zaras, N; Bogdanis, G; Papadimas, G; Terzis, G

    2017-11-01

    Aim of the study was to investigate whether high-intensity interval cycling performed immediately after resistance training would inhibit muscle strength increase and hypertrophy expected from resistance training per se. Twenty-two young men were assigned into either resistance training (RE; N = 11) or resistance training plus high-intensity interval cycling (REC; N = 11). Lower body muscle strength and rate of force development (RFD), quadriceps cross-sectional area (CSA) and vastus lateralis muscle architecture, muscle fiber type composition and capillarization, and estimated aerobic capacity were evaluated before and after 8 weeks of training (2 times per week). Muscle strength and quadriceps CSA were significantly and similarly increased after both interventions. Fiber CSA increased significantly and similarly after both RE (type I: 13.6 ± 3.7%, type IIA: 17.6 ± 4.4%, type IIX: 23.2 ± 5.7%, P high-intensity interval cycling performed after heavy-resistance exercise may not inhibit resistance exercise-induced muscle strength/hypertrophy after 2 months of training, while it prompts aerobic capacity and muscle capillarization. The addition of high-intensity cycling after heavy-resistance exercise may decrease RFD partly due to muscle architectural changes. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  16. High Performance Artificial Muscles Using Nanofiber and Hybrid Yarns

    2015-07-14

    2. Above advance led to “Artificial Muscles From Fishing Line and Sewing Thread”, which was patent filed and then published in Science in 2014...consuming significant energy. The publication of Artificial Muscles From Fishing Line and Sewing Thread (Science, 2014) generated TV, radio, and other...gn f cant energy. The pub cat on of “Art f c a Musc es From F sh ng L ne and Sew ng Thread” (Sc ence, 2014) generated TV, rad o, and other wor d-w de

  17. Feasibility of resistance training in adult McArdle patients: clinical outcomes and muscle strength and mass benefits.

    Santalla, Alfredo; Munguía-Izquierdo, Diego; Brea-Alejo, Lidia; Pagola-Aldazábal, Itziar; Díez-Bermejo, Jorge; Fleck, Steven J; Ara, Ignacio; Lucia, Alejandro

    2014-01-01

    We analyzed the effects of a 4-month resistance (weight lifting) training program followed by a 2-month detraining period in 7 adult McArdle patients (5 female) on: muscle mass (assessed by DXA), strength, serum creatine kinase (CK) activity and clinical severity. Adherence to training was ≥84% in all patients and no major contraindication or side effect was noted during the training or strength assessment sessions. The training program had a significant impact on total and lower extremities' lean mass (P training by +855 g (95% confidence interval (CI): 30, 1679) and +547 g (95%CI: 116, 978), respectively, and significantly decreasing with detraining. Body fat showed no significant changes over the study period. Bench press and half-squat performance, expressed as the highest value of average muscle power (W) or force (N) in the concentric-repetition phase of both tests showed a consistent increase over the 4-month training period, and decreased with detraining. Yet muscle strength and power detraining values were significantly higher than pre-training values, indicating that a training effect was still present after detraining. Importantly, all the participants, with no exception, showed a clear gain in muscle strength after the 4-month training period, e.g., bench press: +52 W (95% CI: 13, 91); half-squat: +173 W (95% CI: 96, 251). No significant time effect (P > 0.05) was noted for baseline or post strength assessment values of serum CK activity, which remained essentially within the range reported in our laboratory for McArdle patients. All the patients changed to a lower severity class with training, such that none of them were in the highest disease severity class (3) after the intervention and, as such, they did not have fixed muscle weakness after training. Clinical improvements were retained, in all but one patient, after detraining, such that after detraining all patients were classed as class 1 for disease severity.

  18. Myosin heavy chain isoform expression in adult and juvenile mini-muscle mice bred for high-voluntary wheel running.

    Talmadge, Robert J; Acosta, Wendy; Garland, Theodore

    2014-11-01

    The myosin heavy chain (MyHC) isoform composition of locomotor and non-locomotor muscles of mini-muscle mice were assessed at the protein and mRNA levels in both adult and juvenile (21 day old) mice. Mini-muscle mice are one outcome of a replicated artificial selection experiment in which four lines of mice were bred for high voluntary wheel running (HR lines). Two of the lines responded with an increase in frequency of a single nucleotide polymorphism in an intron in the MyHC-2b gene (myh4) that when homozygous causes a dramatic reduction in triceps surae mass. We found that both locomotor and non-locomotor muscles of adult mini-muscle mice displayed robust reductions, but not elimination, of the MyHC-2b isoform at both the protein and mRNA levels, with commensurate increases in MyHC-2x and sometimes MyHC-2a, as compared with either a line of HR mice that does not display the mini-muscle phenotype or inbred C57Bl6 mice. Immunohistochemical analyses revealed that locomotor muscles of mini-muscle mice contain fibers that express the MyHC-2b isoform, which migrates normally in SDS-PAGE gels. However, these MyHC-2b positive fibers are generally smaller than the surrounding fibers and smaller than the MyHC-2b positive fibers of non-mini-muscle mice, resulting in characteristically fast muscles that lack a substantial MyHC-2b positive (superficial) region. In contrast, the masseter, a non-locomotor muscle of mini-muscle mice contained MyHC-2b positive fibers that stained more lightly for MyHC-2b, but appeared normal in size and distribution. In adults, many of the MyHC-2b positive fibers in the mini-muscle mice also display central nuclei. Only a small proportion of small MyHC-2b fibers in mini-muscle mice stained positive for the neural cell adhesion molecule, suggesting that anatomical innervation was not compromised. In addition, weanling (21 day old), but not 5 day old mice, displayed alterations in MyHC isoform content at both the protein and mRNA levels, including

  19. Ratio of Dietary n-6/n-3 Polyunsaturated Fatty Acids Independently Related to Muscle Mass Decline in Hemodialysis Patients.

    Te-Chih Wong

    Full Text Available n-3 polyunsaturated fatty acids (PUFAs might be useful nutritional strategy for treating patients with sarcopenia. We evaluated the effect of the intake of dietary n-3 PUFAs on the skeletal muscle mass (SMM, appendicular skeletal muscle mass (ASM, and its determinants in patients receiving standard hemodialysis (HD treatment for the management of end stage renal disease.In this cross-sectional study, data of 111 HD patients were analyzed. Anthropometric and bioelectrical impedance measurements used to estimate the muscle mass were performed the day of dialysis immediately after the dialysis session. Routine laboratory and 3-day dietary data were also collected. The cutoff value of adequate intake (AI for both n-3 PUFAs and alpha-linolenic acid (ALA was 1.6 g/day and 1.1 g/day for men and women, respectively.The mean age, mean dietary n-3 PUFAs intake, ALA intake, ratio of n-6/n-3 PUFAs intake, SMM, and ASM of patients were 61.4 ± 10.4 years, 2.0 ± 1.3 g/day, 1.5 ± 1.0 g/day, 9.5 ± 6.7 g/day, 23.9 ± 5.5 kg, and 17.5 ± 4.5 kg, respectively. A higher SMM and ASM significantly observed in patients who achieved an AI of n-3 PUFAs. Similar trends appeared to be observed among those patients who achieved the AI of ALA, but the difference was not significantly, except for ASM (P = 0.047. No relevant differences in demographics, laboratory and nutritional parameters were observed, regardless of whether the patients achieved an AI of n-3 PUFAs. Multivariate analysis showed that the BMI and equilibrated Kt/V were independent determinants of the muscle mass. Moreover, the ratio of n-6/n-3 PUFAs was an independent risk determinant of reduced ASM in HD patients.Patients with an AI of n-3 PUFAs had better total-body SMM and ASM. A higher dietary ratio of n-6/n-3 PUFAs seemed to be associated with a reduced muscle mass in HD patients.

  20. Ratio of Dietary n-6/n-3 Polyunsaturated Fatty Acids Independently Related to Muscle Mass Decline in Hemodialysis Patients.

    Wong, Te-Chih; Chen, Yu-Tong; Wu, Pei-Yu; Chen, Tzen-Wen; Chen, Hsi-Hsien; Chen, Tso-Hsiao; Yang, Shwu-Huey

    2015-01-01

    n-3 polyunsaturated fatty acids (PUFAs) might be useful nutritional strategy for treating patients with sarcopenia. We evaluated the effect of the intake of dietary n-3 PUFAs on the skeletal muscle mass (SMM), appendicular skeletal muscle mass (ASM), and its determinants in patients receiving standard hemodialysis (HD) treatment for the management of end stage renal disease. In this cross-sectional study, data of 111 HD patients were analyzed. Anthropometric and bioelectrical impedance measurements used to estimate the muscle mass were performed the day of dialysis immediately after the dialysis session. Routine laboratory and 3-day dietary data were also collected. The cutoff value of adequate intake (AI) for both n-3 PUFAs and alpha-linolenic acid (ALA) was 1.6 g/day and 1.1 g/day for men and women, respectively. The mean age, mean dietary n-3 PUFAs intake, ALA intake, ratio of n-6/n-3 PUFAs intake, SMM, and ASM of patients were 61.4 ± 10.4 years, 2.0 ± 1.3 g/day, 1.5 ± 1.0 g/day, 9.5 ± 6.7 g/day, 23.9 ± 5.5 kg, and 17.5 ± 4.5 kg, respectively. A higher SMM and ASM significantly observed in patients who achieved an AI of n-3 PUFAs. Similar trends appeared to be observed among those patients who achieved the AI of ALA, but the difference was not significantly, except for ASM (P = 0.047). No relevant differences in demographics, laboratory and nutritional parameters were observed, regardless of whether the patients achieved an AI of n-3 PUFAs. Multivariate analysis showed that the BMI and equilibrated Kt/V were independent determinants of the muscle mass. Moreover, the ratio of n-6/n-3 PUFAs was an independent risk determinant of reduced ASM in HD patients. Patients with an AI of n-3 PUFAs had better total-body SMM and ASM. A higher dietary ratio of n-6/n-3 PUFAs seemed to be associated with a reduced muscle mass in HD patients.

  1. Low vitamin D status is associated with reduced muscle mass and impaired physical performance in frail elderly people.

    Tieland, M; Brouwer-Brolsma, E M; Nienaber-Rousseau, C; van Loon, L J C; De Groot, L C P G M

    2013-10-01

    Serum 25-hydroxyvitamin D (25(OH)D) status has been associated with muscle mass, strength and physical performance in healthy elderly people. Yet, in pre-frail and frail elderly people this association has not been studied. The objective of this study was to explore the association between vitamin D intake and serum 25(OH)D status with muscle mass, strength and physical performance in a pre-frail and frail elderly population. This cross-sectional study included 127 pre-frail and frail elderly people in The Netherlands. Whole body and appendicular lean mass (ALM) (dual energy X-ray absorptiometry), leg strength (one repetition maximum), handgrip strength and physical performance (short physical performance battery) were measured, and blood samples were collected for the assessment of serum 25(OH)D status (liquid chromatography-tandem mass spectrometry). In addition, habitual dietary intake (3-day food records) and physical activity data (accelerometers) were collected. In total, 53% of the participants had a serum 25(OH)D level below 50  nmol/l. After adjustment for confounding factors, 25(OH)D status was associated with ALM (β=0.012, P=0.05) and with physical performance (β=0.020, PVitamin D intake was associated with physical performance (β=0.18, P0.05). In this frail elderly population, 25(OH)D status is low and suggests a modest association with reduced ALM and impaired physical performance. In addition, vitamin D intake tended to be associated with impaired physical performance. Our findings highlight the need for well-designed intervention trials to assess the impact of vitamin D supplementation on 25(OH)D status, muscle mass and physical performance in pre-frail and frail elderly people.

  2. Physical activity as intervention for age-related loss of muscle mass and function

    Eriksen, Christian Skou; Garde, Ellen; Reislev, Nina Linde

    2016-01-01

    insights into training-induced promotion of functional ability and independency after retirement and will help to formulate national recommendations regarding physical activity schemes for the growing population of older individuals in western societies. Results will be published in scientific peer......INTRODUCTION: Physical and cognitive function decline with age, accelerating during the 6th decade. Loss of muscle power (force×velocity product) is a dominant physical determinant for loss of functional ability, especially if the lower extremities are affected. Muscle strength training is known...... to maintain or even improve muscle power as well as physical function in older adults, but the optimal type of training for beneficial long-term training effects over several years is unknown. Moreover, the impact of muscle strength training on cognitive function and brain structure remains speculative...

  3. High precision mass measurements in Ψ and Υ families revisited

    Artamonov, A.S.; Baru, S.E.; Blinov, A.E.

    2000-01-01

    High precision mass measurements in Ψ and Υ families performed in 1980-1984 at the VEPP-4 collider with OLYA and MD-1 detectors are revisited. The corrections for the new value of the electron mass are presented. The effect of the updated radiative corrections has been calculated for the J/Ψ(1S) and Ψ(2S) mass measurements [ru

  4. High-sensitivity mass spectrometry with a tandem accelerator

    Henning, W.

    1984-01-01

    The characteristic features of accelerator mass spectrometry are discussed. A short overview is given of the current status of mass spectrometry with high-energy (MeV/nucleon) heavy-ion accelerators. Emphasis is placed on studies with tandem accelerators and on future mass spectrometry of heavier isotopes with the new generation of higher-voltage tandems

  5. Protein supplementation increases muscle mass gain during prolonged resistance-type exercise training in frail elderly people: a randomized double-blind, placebo-controlled trial

    Tieland, C.A.B.; Dirks, M.L.; Zwaluw, van der N.L.; Verdijk, L.; Rest, van de O.; Groot, de C.P.G.M.; Loon, van L.C.

    2012-01-01

    Objectives Protein supplementation has been proposed as an effective dietary strategy to augment the skeletal muscle adaptive response to prolonged resistance-type exercise training in elderly people. Our objective was to assess the impact of protein supplementation on muscle mass, strength, and

  6. Association between −308 G/A TNF-α Polymorphism and Appendicular Skeletal Muscle Mass Index as a Marker of Sarcopenia in Normal Weight Obese Syndrome

    L. Di Renzo

    2013-01-01

    Full Text Available Background and Aim. Normal weight obese (NWO syndrome is characterized by normal body mass index (BMI, but high amount of fat mass and reduced lean mass. We evaluated allelic frequency of the G/A −308 TNF-α polymorphism and prevalence of sarcopenia in NWO. Methods. We enrolled 120 Italian healthy women, distinguished into 3 groups: normal weight (NW; NWO, and preobese-obese (PreOB/OB and evaluated anthropometric parameters, body composition by dual X-ray absorptiometry, blood tests, and genotyping of G/A −308 TNF-α polymorphism. Results. We found a positive association between sarcopenic obesity and −308 TNF-α polymorphism. All obese women were sarcopenic and were no carrier of mutation (G/G. Among all G/G, NWO showed significant differences in lean mass and total body lean mass (TBLean with respect to NW and PreOB/OB (P<0.001. Regarding appendicular skeletal muscle mass index values, 4.21% of NW were sarcopenic (50% G/G and 50% G/A; the same percentage was observed in NWO subjects (100% G/G. Moreover, 2.10% of PreOB/OB were sarcopenic and all were G/G. Conclusion. Our study suggests that TNF-α polymorphism contributes to sarcopenic obesity susceptibility, in association with body composition. This is the first study that shows the importance of TNF-α polymorphism to determine TBLean variation in NWO syndrome.

  7. Association between -308 G/A TNF-α polymorphism and appendicular skeletal muscle mass index as a marker of sarcopenia in normal weight obese syndrome.

    Di Renzo, L; Sarlo, F; Petramala, L; Iacopino, L; Monteleone, G; Colica, C; De Lorenzo, A

    2013-01-01

    Normal weight obese (NWO) syndrome is characterized by normal body mass index (BMI), but high amount of fat mass and reduced lean mass. We evaluated allelic frequency of the G/A -308 TNF-α polymorphism and prevalence of sarcopenia in NWO. We enrolled 120 Italian healthy women, distinguished into 3 groups: normal weight (NW); NWO, and preobese-obese (PreOB/OB) and evaluated anthropometric parameters, body composition by dual X-ray absorptiometry, blood tests, and genotyping of G/A -308 TNF-α polymorphism. We found a positive association between sarcopenic obesity and -308 TNF-α polymorphism. All obese women were sarcopenic and were no carrier of mutation (G/G). Among all G/G, NWO showed significant differences in lean mass and total body lean mass (TBLean) with respect to NW and PreOB/OB (P skeletal muscle mass index values, 4.21% of NW were sarcopenic (50% G/G and 50% G/A); the same percentage was observed in NWO subjects (100% G/G). Moreover, 2.10% of PreOB/OB were sarcopenic and all were G/G. Our study suggests that TNF-α polymorphism contributes to sarcopenic obesity susceptibility, in association with body composition. This is the first study that shows the importance of TNF-α polymorphism to determine TBLean variation in NWO syndrome.

  8. Unilateral hindlimb casting induced a delayed generalized muscle atrophy during rehabilitation that is prevented by a whey or a high protein diet but not a free leucine-enriched diet.

    Hugues Magne

    Full Text Available Sarcopenia is the general muscle mass and strength loss associated with ageing. Muscle atrophy could be made worse by exposure to acute periods of immobilization, because muscle disuse by itself is a stimulus for atrophy. Using a model of unilateral hindlimb casting in old adult rats, we have already demonstrated that the primary effect of immobilization was atrophy in the casted leg, but was also surprisingly associated with a retarded atrophy in the non-casted leg during rehabilitation. In search of mechanisms involved in this generalized atrophy, we demonstrated in the present study that contrary to pair-fed non-immobilized control animals, muscle protein synthesis in the non-immobilized limb was unable to adapt and to respond positively to food intake. Because pair-fed control rats did not lose muscle mass, this defect in muscle protein synthesis may represent one of the explanation for the muscle mass loss observed in the non-immobilized rats. Nevertheless, in order to stimulate protein turn over and generate a positive nitrogen balance required to maintain the whole muscle mass in immobilized rats, we tested a dietary free leucine supplementation (an amino acid known for its stimulatory effect on protein metabolism during the rehabilitation period. Leucine supplementation was able to overcome the anabolic resistance in the non-immobilized limb. A greater muscle protein synthesis up-regulation associated with a stimulation of the mTOR signalling pathway was indeed recorded but it remained inefficient to prevent the loss of muscle in the non-immobilized limb. By contrast, we demonstrated here that whey protein or high protein diets were able to prevent the muscle mass loss of the non-immobilized limb by sustaining muscle protein synthesis during the entire rehabilitation period.

  9. Effect of modified fasting therapy on body weight, fat and muscle mass, and blood chemistry in patients with obesity.

    Kim, Koh-Woon; Song, Mi-Yeon; Chung, Seok-Hee; Chung, Won-Seok

    2016-02-01

    The aim of this study was to investigate the effects and safety of modified fasting therapy using fermented medicinal herbs and exercise on body weight, fat and muscle mass, and blood chemistry in obese subjects. Twenty-six patients participated in a 14-day fast, during which they ingested a supplement made from fermented medicinal herbs and carbohydrates (intake: 400-600 kcal/d). The schedule included 7 prefasting relief days and 14 days of stepwise reintroduction of food. The patients also took part in an exercise program that incorporated Qigong, weight training, and walking exercises. The efficacy of treatments was observed by assessing body fat mass and muscle mass, and alanine aminotransferase (ALT), aspartate aminotransferase (AST), cholesterol, and triglycerides in each study period. Specific symptoms or side effects were reported. Body weight and body fat mass both decreased significantly by (5.16 ± 0.95) and (3.89 ± 0.79) kg (both P fasting therapy using fermented medicinal herbs and exercise could be effective and safe on obese patients.

  10. Lack of independent effect of type 2 diabetes beyond characteristic comorbidities and medications on small muscle mass exercising muscle blood flow and exercise tolerance.

    Poitras, Veronica J; Bentley, Robert F; Hopkins-Rosseel, Diana H; LaHaye, Stephen A; Tschakovsky, Michael E

    2015-08-01

    Persons with type 2 diabetes (T2D) are believed to have reduced exercise tolerance; this may be partly due to impaired exercising muscle blood flow (MBF). Whether there is an impact of T2D on exercising MBF within the typical constellation of comorbidities (hypertension, dyslipidemia, obesity) and their associated medications has not been investigated. We tested the hypothesis that small muscle mass exercise tolerance is reduced in persons with T2D versus Controls (matched for age, body mass index, fitness, comorbidities, non-T2D medications) and that this is related to blunted MBF. Eight persons with T2D and eight controls completed a forearm critical force (fCFimpulse) test as a measure of exercise tolerance (10-min intermittent maximal effort forearm contractions; the average contraction impulse in the last 30 sec quantified fCFimpulse). Forearm blood flow (FBF; ultrasound) and mean arterial pressure (MAP; finger photoplethysmography) were measured; forearm vascular conductance (FVK) was calculated. Data are means ± SD, T2D versus Control. fCFimpulse was not different between groups (136.9 ± 47.3  N·sec vs. 163.1 ± 49.7 N·sec, P = 0.371) nor was the ∆FBF from rest to during exercise at fCFimpulse (502.9 ± 144.6 vs. 709.1 ± 289.2 mL/min, P = 0.092), or its determinants ∆FVK and ∆MAP (both P > 0.05), although there was considerable interindividual variability. ∆FBF was strongly related to fCFimpulse (r = 0.727, P = 0.002), providing support for the relationship between oxygen delivery and exercise tolerance. We conclude that small muscle mass exercising MBF and exercise tolerance are not impaired in representative persons with T2D versus appropriately matched controls. This suggests that peripheral vascular control impairment does not contribute to reduced exercise tolerance in this population. © 2015 The Authors. Physiological Reports published by Wiley Periodicals, Inc. on behalf of the American Physiological Society and

  11. Mechanical muscle function and lean body mass during supervised strength training and testosterone therapy in aging men with low-normal testosterone levels

    Kvorning, Thue; Christensen, Louise L; Madsen, Klavs

    2013-01-01

    To examine the effect of strength training and testosterone therapy on mechanical muscle function and lean body mass (LBM) in aging men with low-normal testosterone levels in a randomized, double-blind, placebo-controlled 24-week study.......To examine the effect of strength training and testosterone therapy on mechanical muscle function and lean body mass (LBM) in aging men with low-normal testosterone levels in a randomized, double-blind, placebo-controlled 24-week study....

  12. Sports Mass Age Therapy on the Reduction of Delayed Onset Muscle Soreness of the Quadriceps Femoris

    Boguszewski Dariusz

    2014-12-01

    Full Text Available Purpose. Massage therapy is one of most commonly applied treatments during athletic training. The aim of this study was to assess the effectiveness of sports massage therapy on reducing post-exercise quadriceps muscle soreness. Methods. A sample of 29 women aged 24-26 years was divided into an experimental group (n = 15 receiving classic sports massage therapy and a control group (n = 14 given no treatment. An exercise session consisting of five sets of deep squat jumps was administered after which lower limb power as assessed via the vertical jump test. Muscle soreness was assessed using the visual analogue scale (VAS and exercise intensity with the Borg Rating of Perceived Exertion Scale. Subsequent measurements of lower limb power and muscle soreness were performed 24, 48, 72 and 96 h after the exercise session. Differences between the measurements were assessed by the Friedman and least significant difference tests while between-group comparisons involved the Mann-Whitney U test. Results. The largest decrease in lower limb power was observed between the first measurement after the exercise session and 24 h later (p < 0.01. The smallest decrease in power was observed in the massage group. The highest levels of muscle soreness were noted 24 h post-exercise in the massage group and 48 h post-exercise in the control group. The experimental group showed a decrease in muscle soreness in each subsequent measurement, with the results close to zero on the VAS 96 h postexercise. Conclusions. Massage therapy quickened recovery and improved muscle efficiency post-exercise and may serve as an effective treatment of muscle soreness. The analgesic effect of massage suggests it should be widely applied in sport, physical therapy and rehabilitation.

  13. Sex and race/ethnic disparities in the cross-sectional association between depressive symptoms and muscle mass: the Multi-ethnic Study of Atherosclerosis.

    Remigio-Baker, Rosemay A; Allison, Matthew A; Schreiner, Pamela J; Carnethon, Mercedes R; Nettleton, Jennifer A; Mujahid, Mahasin S; Szklo, Moyses; Crum, Rosa M; Leuotsakos, Jeannie-Marie; Franco, Manuel; Jensky, Nicole; Golden, Sherita Hill

    2015-09-18

    The cross-sectional area of total muscle mass has been reported to decrease by about 40% for those 20-60 years of age. Depressive symptoms may discourage motivation to engage in physical activity such as strength training shown to negate muscle loss. Inflammation related to depressive symptoms may also contribute to muscle atrophy. Physiological differences by sex and race/ethnicity may also modify the association between depression and muscle mass. Evidence on the relationship between depression (or depressive symptoms) and adiposity has been mounting; however, little is known about the depressive symptoms-muscle mass association. We sought to determine the association between elevated depressive symptoms (EDS) and lean muscle mass and whether this varies by sex and race/ethnicity. Evaluating 1605 adults (45-84 years of age) from the Multi-ethnic Study of Atherosclerosis Abdominal Body Composition, Inflammation and Cardiovascular Disease Study, we examined the cross-sectional association between EDS (Center for Epidemiologic Studies for Depression Scale score≥16 and/or antidepressant use) and computed tomography-measured abdominal lean muscle mass using linear regression. Muscles were evaluated as a whole and by functionality (locomotion vs. stabilization/posture). Covariates included height, body mass index, sociodemographics, comorbidities, inflammatory markers and health behaviors (pack-years of smoking, alcohol locomotion compared to men, total intentional exercise, daily caloric intake). Sex and race/ethnicity were assessed as potential modifiers. Statistical significance was at a pdepressive symptoms had 5.9 cm2 lower lean muscle mass for locomotion compared to men without EDS, fully-adjusted (CI=-10.5, -1.4, p=0.011). This was statistically significantly different from the null finding among women (interaction p=0.05). Chinese participants with EDS had 10.2 cm2 lower abdominal lean muscle mass for locomotion compared to those without EDS (fully

  14. High-Precision Mass Measurements of Exotic Nuclei with the Triple-Trap Mass Spectrometer Isoltrap

    Blaum, K; Zuber, K T; Stanja, J

    2002-01-01

    The masses of close to 200 short-lived nuclides have already been measured with the mass spectrometer ISOLTRAP with a relative precision between 1$\\times$10$^{-7}$ and 1$\\times$10^{-8}$. The installatin of a radio-frequency quadrupole trap increased the overall efficiency by two orders of magnitude which is at present about 1%. In a recent upgrade, we installed a carbon cluster laser ion source, which will allow us to use carbon clusters as mass references for absolute mass measurements. Due to these improvements and the high reliability of ISOLTRAP we are now able to perform accurate high-precision mass measurements all over the nuclear chart. We propose therefore mass measurements on light, medium and heavy nuclides on both sides of the valley of stability in the coming four years. ISOLTRAP is presently the only instrument capable of the high precision required for many of the proposed studies.

  15. Chronic β2 -adrenoceptor agonist treatment alters muscle proteome and functional adaptations induced by high intensity training in young men.

    Hostrup, Morten; Onslev, Johan; Jacobson, Glenn A; Wilson, Richard; Bangsbo, Jens

    2018-01-15

    While several studies have investigated the effects of exercise training in human skeletal muscle and the chronic effect of β 2 -agonist treatment in rodent muscle, their effects on muscle proteome signature with related functional measures in humans are still incompletely understood. Herein we show that daily β 2 -agonist treatment attenuates training-induced enhancements in exercise performance and maximal oxygen consumption, and alters muscle proteome signature and phenotype in trained young men. Daily β 2 -agonist treatment abolished several of the training-induced enhancements in muscle oxidative capacity and caused a repression of muscle metabolic pathways; furthermore, β 2 -agonist treatment induced a slow-to-fast twitch muscle phenotype transition. The present study indicates that chronic β 2 -agonist treatment confounds the positive effect of high intensity training on exercise performance and oxidative capacity, which is of interest for the large proportion of persons using inhaled β 2 -agonists on a daily basis, including athletes. Although the effects of training have been studied for decades, data on muscle proteome signature remodelling induced by high intensity training in relation to functional changes in humans remains incomplete. Likewise, β 2 -agonists are frequently used to counteract exercise-induced bronchoconstriction, but the effects β 2 -agonist treatment on muscle remodelling and adaptations to training are unknown. In a placebo-controlled parallel study, we randomly assigned 21 trained men to 4 weeks of high intensity training with (HIT+β 2 A) or without (HIT) daily inhalation of β 2 -agonist (terbutaline, 4 mg dose -1 ). Of 486 proteins identified by mass-spectrometry proteomics of muscle biopsies sampled before and after the intervention, 32 and 85 were changing (false discovery rate (FDR) ≤5%) with the intervention in HIT and HIT+β 2 A, respectively. Proteome signature changes were different in HIT and HIT+β 2 A (P

  16. Mitochondrial function in human skeletal muscle following high-altitude exposure

    Jacobs, Robert A; Boushel, Robert; Wright-Paradis, Cynthia

    2013-01-01

    Studies regarding mitochondrial modifications in human skeletal muscle following acclimatization to high altitude are conflicting, and these inconsistencies may be due to the prevalence of representing mitochondrial function through static and isolated measurements of specific mitochondrial...... characteristics. The aim of this study, therefore, was to investigate mitochondrial function in response to high-altitude acclimatization through measurements of respiratory control in the vastus lateralis muscle. Skeletal muscle biopsies were obtained from 10 lowland natives prior to and again after a total of 9......-11 days of exposure to 4559 m. High-resolution respirometry was performed on the muscle samples to compare respiratory chain function and respiratory capacities. Respirometric analysis revealed that mitochondrial function was largely unaffected, because high-altitude exposure did not affect the capacity...

  17. Beyond Body Mass Index. Is the Body Cell Mass Index (BCMI) a useful prognostic factor to describe nutritional, inflammation and muscle mass status in hospitalized elderly?: Body Cell Mass Index links in elderly.

    Rondanelli, Mariangela; Talluri, Jacopo; Peroni, Gabriella; Donelli, Chiara; Guerriero, Fabio; Ferrini, Krizia; Riggi, Emilia; Sauta, Elisabetta; Perna, Simone; Guido, Davide

    2018-06-01

    The aim of this study was to establish the effectiveness of Body Cell Mass Index (BCMI) as a prognostic index of (mal)nutrition, inflammation and muscle mass status in the elderly. A cross-sectional observational study has been conducted on 114 elderly patients (80 women and 34 men), with mean age equal to 81.07 ± 6.18 years. We performed a multivariate regression model by Structural Equation Modelling (SEM) framework. We detected the effects over a Mini Nutritional Assessment (MNA) stratification, by performing a multi-group multivariate regression model (via SEM) in two MNA nutritional strata, less and bigger (or equal) than 17. BCMI had a significant effect on albumin (β = +0.062, P = 0.001), adjusting for the other predictors of the model as Body Mass Index (BMI), age, sex, fat mass and cognitive condition. An analogous result is maintained in MNAelderly patients. Copyright © 2017 Elsevier Ltd and European Society for Clinical Nutrition and Metabolism. All rights reserved.

  18. Butyryl-cholinesterase is related to muscle mass and strength. A new biomarker to identify elderly subjects at risk of sarcopenia.

    Cacciatore, Francesco; Della-Morte, David; Basile, Claudia; Curcio, Francesco; Liguori, Ilaria; Roselli, Mario; Gargiulo, Gaetano; Galizia, Gianluigi; Bonaduce, Domenico; Abete, Pasquale

    2015-01-01

    To determine the relationship between Butyryl-cholinesterase (α-glycoprotein synthesized in the liver, b-CHE) and muscle mass and strength. Muscle mass by bioimpedentiometer and muscle strength by grip strength were evaluated in 337 elderly subjects (mean age: 76.2 ± 6.7 years) admitted to comprehensive geriatric assessment. b-CHE levels were lower in sarcopenic than in nonsarcopenic elderly subjects (p elderly subjects. Thus, b-CHE may be considered to be a fair biomarker for identifying elderly subjects at risk of sarcopenia.

  19. Recumbent vs. upright bicycles: 3D trajectory of body centre of mass, limb mechanical work, and operative range of propulsive muscles.

    Telli, Riccardo; Seminati, Elena; Pavei, Gaspare; Minetti, Alberto Enrico

    2017-03-01

    Recumbent bicycles (RB) are high performance, human-powered vehicles. In comparison to normal/upright bicycles (NB) the RB may allow individuals to reach higher speeds due to aerodynamic advantages. The purpose of this investigation was to compare the non-aerodynamic factors that may potentially influence the performance of the two bicycles. 3D body centre of mass (BCoM) trajectory, its symmetries, and the components of the total mechanical work necessary to sustain cycling were assessed through 3D kinematics and computer simulations. Data collected at 50, 70, 90 110 rpm during stationary cycling were used to drive musculoskeletal modelling simulation and estimate muscle-tendon length. Results demonstrated that BCoM trajectory, confined in a 15-mm side cube, changed its orientation, maintaining a similar pattern across all cadences in both bicycles. RB displayed a reduced additional mechanical external power (16.1 ± 9.7 W on RB vs. 20.3 ± 8.8 W on NB), a greater symmetry on the progression axis, and no differences in the internal mechanical power compared to NB. Simulated muscle activity revealed small significant differences for only selected muscles. On the RB, quadriceps and gluteus demonstrated greater shortening, while biceps femoris, iliacus, and psoas exhibited greater stretch; however, aerodynamics still remains the principal benefit.

  20. BACK MUSCLES STRENGTH DEVELOPMENT BY MEANS OF INCREASE AND DECREASE OF EFFORT LOAD DURING GIANT SETS IN BODYBUILDING FOR MASSES

    TIMNEA OLIVIA

    2013-01-01

    Full Text Available Abstract The aim of the study is to highlight methodological issues on the back muscle strength development by combining methodological procedures in masses bodybuilding.Methods. The study was conducted in three stages over a period of two months (March-April 2011, performing three workouts per week, monitoring the effective use of strength exercises to develop back muscles in the same muscle area by means of giant sets during workouts. In this context, we conducted a case study in "Tonik Fitness Club" in Bucharest, applied to two athletes of 28 and 34 years old. We recorded subjects’ evolutions during the training session, using statistical and mathematical method and graphical representation method.Results. The study content highlights the training programs depending on muscle zone and the specific methodological aspects, the weekly training program per muscle groups, the stages of study carrying out, the test and control trials applied in terms of anthropometric measurements and of back muscle strength development, and the application of the methodical procedure of effort load increase and decrease within the giant sets in a training micro-cycle.Discussion. The study focused on the training programs over two months, monitoring statistically the development of back muscle strength through the application of the procedure of effort load increase and decrease during giant sets in bodybuilding for masses. From the analysis of training programs content we noticed that three giant sets of exercises were used, performed in four series; each exercise within the giant sets was applied by means of the procedure of increasing and decreasing effort load. Study results emphasize the anthropometric measurement results: the study subjects have the age mean of 24.75, with a size of 175.2 cm and a weight of 83.75 kg at initial testing and a decrease by 2.12 kg in final testing. Regarding the chest perimeter, the inspiration is averaging 89.5 in initial

  1. Biomarker discovery in high grade sarcomas by mass spectrometry imaging

    Lou, S.

    2017-01-01

    This thesis demonstrates a detailed biomarker discovery Mass Spectrometry Imaging workflow for histologically heterogeneous high grade sarcomas. Panels of protein and metabolite signatures were discovered either distinguishing different histological subtypes or stratifying high risk patients with poor survival.

  2. Dexamethasone and BCAA Failed to Modulate Muscle Mass and mTOR Signaling in GH-Deficient Rats.

    Nishida, Hikaru; Ikegami, Ayaka; Kaneko, Chiaki; Kakuma, Hitomi; Nishi, Hisano; Tanaka, Noriko; Aoyama, Michiko; Usami, Makoto; Okimura, Yasuhiko

    2015-01-01

    Branched-chain amino acids (BCAAs) and IGF-I, the secretion of which is stimulated by growth hormone (GH), prevent muscle atrophy. mTOR plays a pivotal role in the protective actions of BCAA and IGF-1. The pathway by which BCAA activates mTOR is different from that of IGF-1, which suggests that BCAA and GH work independently. We tried to examine whether BCAA exerts a protective effect against dexamethasone (Dex)-induced muscle atrophy independently of GH using GH-deficient spontaneous dwarf rats (SDRs). Unexpectedly, Dex did not induce muscle atrophy assessed by the measurement of cross-sectional area (CSA) of the muscle fibers and did not increase atrogin-1, MuRF1 and REDD1 expressions, which are activated during protein degradation. Glucocorticoid (GR) mRNA levels were higher in SDRs compared to GH-treated SDRs, indicating that the low expression of GR is not the reason of the defect of Dex's action in SDRs. BCAA did not stimulate the phosphorylation of p70S6K or 4E-BP1, which stimulate protein synthesis. BCAA did not decrease the mRNA level of atrogin-1 or MuRF1. These findings suggested that Dex failed to modulate muscle mass and that BCAA was unable to activate mTOR in SDRs because these phosphorylations of p70S6K and 4E-BP1 and the reductions of these mRNAs are regulated by mTOR. In contrast, after GH supplementation, these responses to Dex were normalized and muscle fiber CSA was decreased by Dex. BCAA prevented the Dex-induced decrease in CSA. BCAA increased the phosphorylation of p70S6K and decreased the Dex-induced elevations of atrogin-1 and Bnip3 mRNAs. However, the amount of mTORC1 components including mTOR was not decreased in the SDRs compared to the normal rats. These findings suggest that GH increases mTORC1 activity but not its content to recover the action of BCAA in SDRs and that GH is required for actions of Dex and BCAA in muscles.

  3. Dexamethasone and BCAA Failed to Modulate Muscle Mass and mTOR Signaling in GH-Deficient Rats.

    Hikaru Nishida

    Full Text Available Branched-chain amino acids (BCAAs and IGF-I, the secretion of which is stimulated by growth hormone (GH, prevent muscle atrophy. mTOR plays a pivotal role in the protective actions of BCAA and IGF-1. The pathway by which BCAA activates mTOR is different from that of IGF-1, which suggests that BCAA and GH work independently. We tried to examine whether BCAA exerts a protective effect against dexamethasone (Dex-induced muscle atrophy independently of GH using GH-deficient spontaneous dwarf rats (SDRs. Unexpectedly, Dex did not induce muscle atrophy assessed by the measurement of cross-sectional area (CSA of the muscle fibers and did not increase atrogin-1, MuRF1 and REDD1 expressions, which are activated during protein degradation. Glucocorticoid (GR mRNA levels were higher in SDRs compared to GH-treated SDRs, indicating that the low expression of GR is not the reason of the defect of Dex's action in SDRs. BCAA did not stimulate the phosphorylation of p70S6K or 4E-BP1, which stimulate protein synthesis. BCAA did not decrease the mRNA level of atrogin-1 or MuRF1. These findings suggested that Dex failed to modulate muscle mass and that BCAA was unable to activate mTOR in SDRs because these phosphorylations of p70S6K and 4E-BP1 and the reductions of these mRNAs are regulated by mTOR. In contrast, after GH supplementation, these responses to Dex were normalized and muscle fiber CSA was decreased by Dex. BCAA prevented the Dex-induced decrease in CSA. BCAA increased the phosphorylation of p70S6K and decreased the Dex-induced elevations of atrogin-1 and Bnip3 mRNAs. However, the amount of mTORC1 components including mTOR was not decreased in the SDRs compared to the normal rats. These findings suggest that GH increases mTORC1 activity but not its content to recover the action of BCAA in SDRs and that GH is required for actions of Dex and BCAA in muscles.

  4. Hypertrophy Stimulation at the Onset of Type I Diabetes Maintains the Soleus but Not the EDL Muscle Mass in Wistar Rats

    Marco A. S. Fortes

    2017-10-01

    Full Text Available Diabetes mellitus induces a reduction in skeletal muscle mass and strength. Strength training is prescribed as part of treatment since it improves glycemic control and promotes increase of skeletal muscle mass. The mechanisms involved in overload-induced muscle hypertrophy elicited at the establishment of the type I diabetic state was investigated in Wistar rats. The purpose was to examine whether the overload-induced hypertrophy can counteract the hypotrophy associated to the diabetic state. The experiments were performed in oxidative (soleus or glycolytic (EDL muscles. PI3K/Akt/mTOR protein synthesis pathway was evaluated 7 days after overload-induced hypertrophy of soleus and of EDL muscles. The mRNA expression of genes associated with different signaling pathways that control muscle hypertrophy was also evaluated: mechanotransduction (FAK, Wnt/β-catenin, myostatin, and follistatin. The soleus and EDL muscles when submitted to overload had similar hypertrophic responses in control and diabetic animals. The increase of absolute and specific twitch and tetanic forces had the same magnitude as muscle hypertrophic response. Hypertrophy of the EDL muscle from diabetic animals mostly involved mechanical loading-stimulated PI3K/Akt/mTOR pathway besides the reduced activation of AMP-activated protein kinase (AMPK and decrease of myostatin expression. Hypertrophy was more pronounced in the soleus muscle of diabetic animals due to a more potent activation of rpS6 and increased mRNA expression of insulin-like growth factor-1 (IGF-1, mechano-growth factor (MGF and follistatin, and decrease of myostatin, MuRF-1 and atrogin-1 contents. The signaling changes enabled the soleus muscle mass and force of the diabetic rats to reach the values of the control group.

  5. Hypertrophy Stimulation at the Onset of Type I Diabetes Maintains the Soleus but Not the EDL Muscle Mass in Wistar Rats

    Fortes, Marco A. S.; Scervino, Maria V. M.; Marzuca-Nassr, Gabriel N.; Vitzel, Kaio F.; da Justa Pinheiro, Carlos H.; Curi, Rui

    2017-01-01

    Diabetes mellitus induces a reduction in skeletal muscle mass and strength. Strength training is prescribed as part of treatment since it improves glycemic control and promotes increase of skeletal muscle mass. The mechanisms involved in overload-induced muscle hypertrophy elicited at the establishment of the type I diabetic state was investigated in Wistar rats. The purpose was to examine whether the overload-induced hypertrophy can counteract the hypotrophy associated to the diabetic state. The experiments were performed in oxidative (soleus) or glycolytic (EDL) muscles. PI3K/Akt/mTOR protein synthesis pathway was evaluated 7 days after overload-induced hypertrophy of soleus and of EDL muscles. The mRNA expression of genes associated with different signaling pathways that control muscle hypertrophy was also evaluated: mechanotransduction (FAK), Wnt/β-catenin, myostatin, and follistatin. The soleus and EDL muscles when submitted to overload had similar hypertrophic responses in control and diabetic animals. The increase of absolute and specific twitch and tetanic forces had the same magnitude as muscle hypertrophic response. Hypertrophy of the EDL muscle from diabetic animals mostly involved mechanical loading-stimulated PI3K/Akt/mTOR pathway besides the reduced activation of AMP-activated protein kinase (AMPK) and decrease of myostatin expression. Hypertrophy was more pronounced in the soleus muscle of diabetic animals due to a more potent activation of rpS6 and increased mRNA expression of insulin-like growth factor-1 (IGF-1), mechano-growth factor (MGF) and follistatin, and decrease of myostatin, MuRF-1 and atrogin-1 contents. The signaling changes enabled the soleus muscle mass and force of the diabetic rats to reach the values of the control group. PMID:29123487

  6. Effects of high-intensity physical training on muscle fiber characteristics in poststroke patients

    Andersen, Jesper Løvind; Jørgensen, Jørgen R.; Zeeman, Peter

    2017-01-01

    INTRODUCTION: Stroke is a leading cause of disability worldwide. High-intensity physical training can improve muscle strength and gait speed, but adaptive mechanisms at the muscle cellular level are largely unknown. METHODS: Outpatients with poststroke hemiparesis participated in a 3-month...... rehabilitation program combining high-intensity strength and body-weight supported treadmill-training. Biopsies sampled bilaterally from vastus lateralis muscles, before, after, and at 1-year follow-up after intervention, were analyzed for fiber size, type, and capillarization. RESULTS: At baseline, paretic...... lower limbs had smaller muscle fiber size and lower type I and IIA and higher type IIX percentages than nonparetic lower limbs. Paretic lower limbs had increased type IIA fibers after training. At follow-up, no difference between the lower limbs remained. CONCLUSIONS: Although high-intensity training...

  7. CONSTRAINTS ON THE RELATIONSHIP BETWEEN STELLAR MASS AND HALO MASS AT LOW AND HIGH REDSHIFT

    Moster, Benjamin P.; Somerville, Rachel S.; Maulbetsch, Christian; Van den Bosch, Frank C.; Maccio, Andrea V.; Naab, Thorsten; Oser, Ludwig

    2010-01-01

    We use a statistical approach to determine the relationship between the stellar masses of galaxies and the masses of the dark matter halos in which they reside. We obtain a parameterized stellar-to-halo mass (SHM) relation by populating halos and subhalos in an N-body simulation with galaxies and requiring that the observed stellar mass function be reproduced. We find good agreement with constraints from galaxy-galaxy lensing and predictions of semi-analytic models. Using this mapping, and the positions of the halos and subhalos obtained from the simulation, we find that our model predictions for the galaxy two-point correlation function (CF) as a function of stellar mass are in excellent agreement with the observed clustering properties in the Sloan Digital Sky Survey at z = 0. We show that the clustering data do not provide additional strong constraints on the SHM function and conclude that our model can therefore predict clustering as a function of stellar mass. We compute the conditional mass function, which yields the average number of galaxies with stellar masses in the range m ± dm/2 that reside in a halo of mass M. We study the redshift dependence of the SHM relation and show that, for low-mass halos, the SHM ratio is lower at higher redshift. The derived SHM relation is used to predict the stellar mass dependent galaxy CF and bias at high redshift. Our model predicts that not only are massive galaxies more biased than low-mass galaxies at all redshifts, but also the bias increases more rapidly with increasing redshift for massive galaxies than for low-mass ones. We present convenient fitting functions for the SHM relation as a function of redshift, the conditional mass function, and the bias as a function of stellar mass and redshift.

  8. Influence of blood flow occlusion on the development of peripheral and central fatigue during small muscle mass handgrip exercise.

    Broxterman, R M; Craig, J C; Smith, J R; Wilcox, S L; Jia, C; Warren, S; Barstow, T J

    2015-09-01

    Critical power represents an important threshold for neuromuscular fatigue development and may, therefore, dictate intensities for which exercise tolerance is determined by the magnitude of fatigue accrued. Peripheral fatigue appears to be constant across O2 delivery conditions for large muscle mass exercise, but this consistency is equivocal for smaller muscle mass exercise. We sought to determine the influence of blood flow occlusion during handgrip exercise on neuromuscular fatigue development and to examine the relationship between neuromuscular fatigue development and W '. Blood flow occlusion influenced the development of both peripheral and central fatigue, thus providing further evidence that the magnitude of peripheral fatigue is not constant across O2 delivery conditions for small muscle mass exercise. W ' appears to be related to the magnitude of fatigue accrued during exercise, which may explain the reported consistency of intramuscular metabolic perturbations and work performed for severe-intensity exercise. The influence of the muscle metabolic milieu on peripheral and central fatigue is currently unclear. Moreover, the relationships between peripheral and central fatigue and the curvature constant (W ') have not been investigated. Six men (age: 25 ± 4 years, body mass: 82 ± 10 kg, height: 179 ± 4 cm) completed four constant power handgrip tests to exhaustion under conditions of control exercise (Con), blood flow occlusion exercise (Occ), Con with 5 min post-exercise blood flow occlusion (Con + Occ), and Occ with 5 min post-exercise blood flow occlusion (Occ + Occ). Neuromuscular fatigue measurements and W ' were obtained for each subject. Each trial resulted in significant peripheral and central fatigue. Significantly greater peripheral (79.7 ± 5.1% vs. 22.7 ± 6.0%) and central (42.6 ± 3.9% vs. 4.9 ± 2.0%) fatigue occurred for Occ than for Con. In addition, significantly greater peripheral (83.0 ± 4.2% vs. 69.0 ± 6.2%) and central

  9. Effect of small-sided team sport training and protein intake on muscle mass, physical function and markers of health in older untrained adults

    Vorup, Jacob; Pedersen, Mogens Theisen; Brahe, Lena Kirchner

    2017-01-01

    The effect of small-sided team sport training and protein intake on muscle mass, physical function, and adaptations important for health in untrained older adults was examined. Forty-eight untrained older (72±6 (±standard deviation, SD) years men and women were divided into either a team sport...... group ingesting a drink high in protein (18 g) immediately and 3 h after each training session (TS-HP, n = 13), a team sport group ingesting an isocaloric drink with low protein content (3 g; TS-LP, n = 18), or a control group continuing their normal activities (CON, n = 17). The team sport training...... was performed as ~20 min of small-sided ball games twice a week over 12 weeks. After the intervention period, leg muscle mass was 0.6 kg higher (P = 0.047) in TS-HP, with no effect in TS-LP. In TS-HP, number of sit-to-stand repetitions increased (1.2±0.6, P = 0.054), time to perform 2.45 m up-and-go was lower...

  10. High-accuracy mass determination of unstable nuclei with a Penning trap mass spectrometer

    2002-01-01

    The mass of a nucleus is its most fundamental property. A systematic study of nuclear masses as a function of neutron and proton number allows the observation of collective and single-particle effects in nuclear structure. Accurate mass data are the most basic test of nuclear models and are essential for their improvement. This is especially important for the astrophysical study of nuclear synthesis. In order to achieve the required high accuracy, the mass of ions captured in a Penning trap is determined via their cyclotron frequency $ \

  11. High-accuracy mass spectrometry for fundamental studies.

    Kluge, H-Jürgen

    2010-01-01

    Mass spectrometry for fundamental studies in metrology and atomic, nuclear and particle physics requires extreme sensitivity and efficiency as well as ultimate resolving power and accuracy. An overview will be given on the global status of high-accuracy mass spectrometry for fundamental physics and metrology. Three quite different examples of modern mass spectrometric experiments in physics are presented: (i) the retardation spectrometer KATRIN at the Forschungszentrum Karlsruhe, employing electrostatic filtering in combination with magnetic-adiabatic collimation-the biggest mass spectrometer for determining the smallest mass, i.e. the mass of the electron anti-neutrino, (ii) the Experimental Cooler-Storage Ring at GSI-a mass spectrometer of medium size, relative to other accelerators, for determining medium-heavy masses and (iii) the Penning trap facility, SHIPTRAP, at GSI-the smallest mass spectrometer for determining the heaviest masses, those of super-heavy elements. Finally, a short view into the future will address the GSI project HITRAP at GSI for fundamental studies with highly-charged ions.

  12. Effect of small-sided team sport training and protein intake on muscle mass, physical function and markers of health in older untrained adults: A randomized trial.

    Vorup, Jacob; Pedersen, Mogens Theisen; Brahe, Lena Kirchner; Melcher, Pia Sandfeld; Alstrøm, Joachim Meno; Bangsbo, Jens

    2017-01-01

    The effect of small-sided team sport training and protein intake on muscle mass, physical function, and adaptations important for health in untrained older adults was examined. Forty-eight untrained older (72±6 (±standard deviation, SD) years men and women were divided into either a team sport group ingesting a drink high in protein (18 g) immediately and 3 h after each training session (TS-HP, n = 13), a team sport group ingesting an isocaloric drink with low protein content (3 g; TS-LP, n = 18), or a control group continuing their normal activities (CON, n = 17). The team sport training was performed as ~20 min of small-sided ball games twice a week over 12 weeks. After the intervention period, leg muscle mass was 0.6 kg higher (P = 0.047) in TS-HP, with no effect in TS-LP. In TS-HP, number of sit-to-stand repetitions increased (1.2±0.6, P = 0.054), time to perform 2.45 m up-and-go was lower (0.7±0.3 s, P = 0.03) and number of arm curl repetitions increased (3.5±1.2, P = 0.01), whereas in TS-LP only number of repetitions in sit-to-stand was higher (1.6±0.6, P = 0.01). In TS-LP, reductions were observed in total and abdominal fat mass (1.2±0.5 and 0.4±0.2 kg, P = 0.03 and P = 0.02, respectively), heart rate at rest (9±3 bpm, P = 0.002) and plasma C-reactive protein (1.8±0.8 mmol/L, P = 0.03), with no effects in TS-HP. Thus, team sport training improves functional capacity of untrained older adults and increases leg muscle mass only when ingesting proteins after training. Furthermore, team sport training followed by intake of drink with low protein content does lower fat mass, heart rate at rest and level of systemic inflammation. clinicaltrials.gov NCT03120143.

  13. Skeletal muscle and performance adaptations to high-intensity training in elite male soccer players

    Fransson, Dan; Nielsen, Tobias Schmidt; Olsson, Karl

    2018-01-01

    PURPOSE: To examine the skeletal muscle and performance responses across two different exercise training modalities which are highly applied in soccer training. METHODS: Using an RCT design, 39 well-trained male soccer players were randomized into either a speed endurance training (SET; n = 21...... pronouncedly than small-sided game training, but comparable responses were in muscle ion transporters and antioxidative capacity in well-trained male soccer players....

  14. Trunk muscle activation during moderate- and high-intensity running.

    Behm, David G; Cappa, Dario; Power, Geoffrey A

    2009-12-01

    Time constraints are cited as a barrier to regular exercise. If particular exercises can achieve multiple training functions, the number of exercises and the time needed to achieve a training goal may be decreased. It was the objective of this study to compare the extent of trunk muscle electromyographic (EMG) activity during running and callisthenic activities. EMG activity of the external obliques, lower abdominals (LA), upper lumbar erector spinae (ULES), and lumbosacral erector spinae (LSES) was monitored while triathletes and active nonrunners ran on a treadmill for 30 min at 60% and 80% of their maximum heart rate (HR) reserve, as well as during 30 repetitions of a partial curl-up and 3 min of a modified Biering-Sørensen back extension exercise. The mean root mean square (RMS) amplitude of the EMG signal was monitored over 10-s periods with measures normalized to a maximum voluntary contraction rotating curl-up (external obliques), hollowing exercise (LA), or back extension (ULES and LSES). A main effect for group was that triathletes had greater overall activation of the external obliques (p runs, respectively, than with the curl-ups (p = 0.001). The back extension exercise provided less ULES (p = 0.009) and LSES (p = 0.0001) EMG activity than the 60% and 80% runs, respectively. In conclusion, triathletes had greater trunk activation than nonrunners did while running, which could have contributed to their better performance. Back-stabilizing muscles can be activated more effectively with running than with a prolonged back extension activity. Running can be considered as an efficient, multifunctional exercise combining cardiovascular and trunk endurance benefits.

  15. Creation of a contusion injury in rabbit skeletal muscle using a drop-mass technique

    Margaret N. Deane

    2013-08-01

    Full Text Available This study reports our experience in developing a simple, minor injury. After reviewing the literature, a ‘drop-mass’ method was selected where a 201 g, elongated oval-shaped weight was dropped up to 15 times through a 1 m tube onto the left vastus lateralis of New Zealand white rabbits. To determine the extent of injury and degree of healing, biopsies were obtained six days after injury from the healing vastus lateralis of each animal. The tissue was fixed in formal saline, embedded in wax, cut and stained with haematoxylin and eosin (H&E and phosphotungstic acid haematoxylin (PTAH and examined by light microscopy (LM. The ‘optimal’ injury was created after seven drops, where quite severe, mild and moderately severe trauma was caused to muscle in the juxta-bone, mid and sub-dermal regions respectively. In each region, the muscle exhibited features of healing six days after injury. The ‘drop-mass’ technique appears to cause a contusion within a single muscle of at least three degrees of severity. This previously unreported observation is of particular importance to other researchers wishing to investigate contusion injury in other animal models.

  16. Effects of Eight Months of Whole-Body Vibration Training on the Muscle Mass and Functional Capacity of Elderly Women.

    Santin-Medeiros, Fernanda; Rey-López, Juan P; Santos-Lozano, Alejandro; Cristi-Montero, Carlos S; Garatachea Vallejo, Nuria

    2015-07-01

    Few intervention studies have used whole-body vibration (WBV) training in the elderly, and there is inconclusive evidence about its health benefits. We examined the effect of 8 months of WBV training on muscle mass and functional capacity in elderly women. A total of 37 women (aged 82.4 ± 5.7 years) voluntarily participated in this study. Subjects were randomly assigned to a vibration group (n = 19) or a control group (n = 18). The vibration group trained on a vertical vibration platform twice a week. The control group was requested not to change their habitual lifestyle. The quadriceps femoris muscle cross-sectional area was determined by magnetic resonance imaging. All participants were evaluated by a battery of tests (Senior Fitness Test) to determine their functional capacity, as well as handgrip strength and balance/gait. General linear repeated-measure analysis of variance (group by time) was performed to examine the effect of the intervention on the outcomes variables. After 8 months, nonstatistically significant differences in the quadriceps CSA (pre-training: 8,516.16 ± 1,271.78 mm² and post-training: 8,671.63 ± 1,389.03 mm²) (p > 0.05) were found in the WBV group (Cohen's d: -0.12), whereas the CON group significantly decreased muscle mass (pre-training: 9,756.18 ± 1,420.07 mm² and post-training: 9,326.82 ± 1,577.53 mm²), with moderate effect size evident (Cohen's d: 0.29). In both groups, no changes were observed in the functional capacity, handgrip strength and balance/gait. The WBV training could prevent the loss of quadriceps CSA in elderly women.

  17. Alternate Mediterranean diet score is positively associated with skeletal muscle mass index in middle-aged adults.

    Tian, Hui-Yuan; Qiu, Rui; Jing, Li-Peng; Chen, Zhan-Yong; Chen, Geng-Dong; Chen, Yu-Ming

    2017-04-01

    Researches have suggested Mediterranean diet might lower the risk of chronic diseases, but data on skeletal muscle mass (SMM) are limited. This community-based cross-sectional study examined the association between the alternate Mediterranean diet score (aMDS) and SMM in 2230 females and 1059 males aged 40-75 years in Guangzhou, China. General information and habitual dietary information were assessed in face-to-face interviews conducted during 2008-2010 and 3 years later. The aMDS was calculated by summing the dichotomous points for the items of higher intakes of whole grain, vegetables, fruits, legumes, nuts, fish and ratio of MUFA:SFA, lower red meat and moderate ethanol consumption. The SMM of the whole body, limbs, arms and legs were measured using dual-energy X-ray absorptiometry during 2011-2013. After adjusting for potential covariates, higher aMDS was positively associated with skeletal muscle mass index (SMI, SMM/height2, kg/m2) at all of the studied sites in males (all P trend0·05). Age-stratified analyses showed that the favourable associations tended to be more pronounced in the younger subjects aged less than the medians of 59·2 and 62·2 years in females and males (P interaction>0·10). In conclusion, the aMDS shows protective associations with SMM in Chinese adults, particularly in male and younger subjects.

  18. Feasibility of resistance training in adult McArdle patients: Clinical outcomes and muscle strength and mass benefits

    Alfredo eSantalla

    2014-12-01

    Full Text Available We analyzed the effects of a 4-month resistance (weight lifting training program followed by a 2-month detraining period in 7 adult McArdle patients (5 female on: muscle mass (assessed by DXA, strength, serum creatine kinase (CK activity and clinical severity. Adherence to training was ≥ 84% in all patients and no major contraindication or side effect was noted during the training or strength assessment sessions. The training program had a significant impact on total and lower extremities’ lean mass (P0.05 was noted for baseline or post strength assessment values of serum CK activity, which remained essentially within the range reported in our laboratory for McArdle patients. All the patients changed to a lower severity class with training, such that none of them were in the highest disease severity class (3 after the intervention and, as such, they did not have fixed muscle weakness after training. Clinical improvements were retained, in all but one patient, after detraining, such that after detraining all patients were classed as class 1 for

  19. Similar muscles contribute to horizontal and vertical acceleration of center of mass in forward and backward walking: implications for neural control

    Jansen, Karen; De Groote, Friedl; Massaad, Firas; Meyns, Pieter; Jonkers, Ilse

    2012-01-01

    Leg kinematics during backward walking (BW) are very similar to the time-reversed kinematics during forward walking (FW). This suggests that the underlying muscle activation pattern could originate from a simple time reversal, as well. Experimental electromyography studies have confirmed that this is the case for some muscles. Furthermore, it has been hypothesized that muscles showing a time reversal should also exhibit a reversal in function [from accelerating the body center of mass (COM) to decelerating]. However, this has not yet been verified in simulation studies. In the present study, forward simulations were used to study the effects of muscles on the acceleration of COM in FW and BW. We found that a reversal in function was indeed present in the muscle control of the horizontal movement of COM (e.g., tibialis anterior and gastrocnemius). In contrast, muscles' antigravity contributions maintained their function for both directions of movement. An important outcome of the present study is therefore that similar muscles can be used to achieve opposite functional demands at the level of control of the COM when walking direction is reversed. However, some muscles showed direction-specific contributions (i.e., dorsiflexors). We concluded that the changes in muscle contributions imply that a simple time reversal would be insufficient to produce BW from FW. We therefore propose that BW utilizes extra elements, presumably supraspinal, in addition to a common spinal drive. These additions are needed for propulsion and require a partial reconfiguration of lower level common networks. PMID:22423005

  20. Fragmented esophageal smooth muscle contraction segments on high resolution manometry: a marker of esophageal hypomotility.

    Porter, R F; Kumar, N; Drapekin, J E; Gyawali, C P

    2012-08-01

    Esophageal peristalsis consists of a chain of contracting striated and smooth muscle segments on high resolution manometry (HRM). We compared smooth muscle contraction segments in symptomatic subjects with reflux disease to healthy controls. High resolution manometry Clouse plots were analyzed in 110 subjects with reflux disease (50 ± 1.4 years, 51.5% women) and 15 controls (27 ± 2.1 years, 60.0% women). Using the 30 mmHg isobaric contour tool, sequences were designated fragmented if either smooth muscle contraction segment was absent or if the two smooth muscle segments were separated by a pressure trough, and failed if both smooth muscle contraction segments were absent. The discriminative value of contraction segment analysis was assessed. A total of 1115 swallows were analyzed (reflux group: 965, controls: 150). Reflux subjects had lower peak and averaged contraction amplitudes compared with controls (P value to HRM analysis. Specifically, fragmented smooth muscle contraction segments may be a marker of esophageal hypomotility. © 2012 Blackwell Publishing Ltd.

  1. Electrospray Ionization Mass Spectrometric Analysis of Highly Reactive Glycosyl Halides

    Lajos Kovács

    2012-07-01

    Full Text Available Highly reactive glycosyl chlorides and bromides have been analysed by a routine mass spectrometric method using electrospray ionization and lithium salt adduct-forming agents in anhydrous acetonitrile solution, providing salient lithiated molecular ions [M+Li]+, [2M+Li]+ etc. The role of other adduct-forming salts has also been evaluated. The lithium salt method is useful for accurate mass determination of these highly sensitive compounds.

  2. Assessment of the influence of body composition on bone mass in children and adolescents based on a functional analysis of the muscle-bone relationship.

    Golec, Joanna; Chlebna-Sokół, Danuta

    2014-01-01

    The functional model of skeletal development considers the mechanical factor to be the most important skeletal modulant. The aim of the study was a functional analysis of the bone-muscle relationship in children with low and normal bone mass. The study involved 149 children with low and 99 children with normal bone mass (control group). All patients underwent a densitometry examination (DXA). Low bone mass was diagnosed if the Z-score was below values of Z-scores for all parameters in children with low bone mass as compared to the control group. Children with low bone mass had lower content of adipose and muscle tissue and a marked deficit of muscle tissue with regard to height (which according to mechanostat theory leads to lower muscle-generated strain on bones). This group of children had also lower TBBMC/LBM Z-scores, which indicates greater fracture susceptibility. 1. Functional analysis, which showed associations between bone and muscle tissues, can be useful for diagnosing and monitoring skeletal system disorders as well as making therapeutic decisions.2. The study emphasizes the role of proper nutrition and physical activities, which contribute to proper body composition, in the prevention of bone mineralization disorders in childhood and adolescence. 3. The study showed the inadequacy of the classic reference ranges used in interpreting DXA data in children and demonstrated the usefulness of continuous variables for that purpose.

  3. A Massive Prestellar Clump Hosting No High-mass Cores

    Sanhueza, Patricio; Lu, Xing; Tatematsu, Ken’ichi [National Astronomical Observatory of Japan, National Institutes of Natural Sciences, 2-21-1 Osawa, Mitaka, Tokyo 181-8588 (Japan); Jackson, James M. [School of Mathematical and Physical Sciences, University of Newcastle, University Drive, Callaghan, NSW 2308 (Australia); Zhang, Qizhou; Stephens, Ian W. [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Guzmán, Andrés E. [Departamento de Astronomía, Universidad de Chile, Camino el Observatorio 1515, Las Condes, Santiago (Chile); Wang, Ke, E-mail: patricio.sanhueza@nao.ac.jp [European Southern Observatory (ESO) Headquarters, Karl-Schwarzschild-Str. 2, D-85748 Garching bei München (Germany)

    2017-06-01

    The infrared dark cloud (IRDC) G028.23-00.19 hosts a massive (1500 M {sub ⊙}), cold (12 K), and 3.6–70 μ m IR dark clump (MM1) that has the potential to form high-mass stars. We observed this prestellar clump candidate with the Submillimeter Array (∼3.″5 resolution) and Jansky Very Large Array (∼2.″1 resolution) in order to characterize the early stages of high-mass star formation and to constrain theoretical models. Dust emission at 1.3 mm wavelength reveals five cores with masses ≤15 M {sub ⊙}. None of the cores currently have the mass reservoir to form a high-mass star in the prestellar phase. If the MM1 clump will ultimately form high-mass stars, its embedded cores must gather a significant amount of additional mass over time. No molecular outflows are detected in the CO (2-1) and SiO (5-4) transitions, suggesting that the SMA cores are starless. By using the NH{sub 3} (1, 1) line, the velocity dispersion of the gas is determined to be transonic or mildly supersonic (Δ V {sub nt}/Δ V {sub th} ∼ 1.1–1.8). The cores are not highly supersonic as some theories of high-mass star formation predict. The embedded cores are four to seven times more massive than the clump thermal Jeans mass and the most massive core (SMA1) is nine times less massive than the clump turbulent Jeans mass. These values indicate that neither thermal pressure nor turbulent pressure dominates the fragmentation of MM1. The low virial parameters of the cores (0.1–0.5) suggest that they are not in virial equilibrium, unless strong magnetic fields of ∼1–2 mG are present. We discuss high-mass star formation scenarios in a context based on IRDC G028.23-00.19, a study case believed to represent the initial fragmentation of molecular clouds that will form high-mass stars.

  4. Preserving Healthy Muscle during Weight Loss123

    Cava, Edda; Yeat, Nai Chien; Mittendorfer, Bettina

    2017-01-01

    Weight loss is the cornerstone of therapy for people with obesity because it can ameliorate or completely resolve the metabolic risk factors for diabetes, coronary artery disease, and obesity-associated cancers. The potential health benefits of diet-induced weight loss are thought to be compromised by the weight-loss–associated loss of lean body mass, which could increase the risk of sarcopenia (low muscle mass and impaired muscle function). The objective of this review is to provide an overview of what is known about weight-loss–induced muscle loss and its implications for overall physical function (e.g., ability to lift items, walk, and climb stairs). The currently available data in the literature show the following: 1) compared with persons with normal weight, those with obesity have more muscle mass but poor muscle quality; 2) diet-induced weight loss reduces muscle mass without adversely affecting muscle strength; 3) weight loss improves global physical function, most likely because of reduced fat mass; 4) high protein intake helps preserve lean body and muscle mass during weight loss but does not improve muscle strength and could have adverse effects on metabolic function; 5) both endurance- and resistance-type exercise help preserve muscle mass during weight loss, and resistance-type exercise also improves muscle strength. We therefore conclude that weight-loss therapy, including a hypocaloric diet with adequate (but not excessive) protein intake and increased physical activity (particularly resistance-type exercise), should be promoted to maintain muscle mass and improve muscle strength and physical function in persons with obesity. PMID:28507015

  5. Use of prediction equations to determine the accuracy of whole-body fat and fat-free mass and appendicular skeletal muscle mass measurements from a single abdominal image using computed tomography in advanced cancer patients.

    Kilgour, Robert D; Cardiff, Katrina; Rosenthall, Leonard; Lucar, Enriqueta; Trutschnigg, Barbara; Vigano, Antonio

    2016-01-01

    Measurements of body composition using dual-energy X-ray absorptiometry (DXA) and single abdominal images from computed tomography (CT) in advanced cancer patients (ACP) have important diagnostic and prognostic value. The question arises as to whether CT scans can serve as surrogates for DXA in terms of whole-body fat-free mass (FFM), whole-body fat mass (FM), and appendicular skeletal muscle (ASM) mass. Predictive equations to estimate body composition for ACP from CT images have been proposed (Mourtzakis et al. 2008; Appl. Physiol. Nutr. Metabol. 33(5): 997-1006); however, these equations have yet to be validated in an independent cohort of ACP. Thus, this study evaluated the accuracy of these equations in estimating FFM, FM, and ASM mass using CT images at the level of the third lumbar vertebrae and compared these values with DXA measurements. FFM, FM, and ASM mass were estimated from the prediction equations proposed by Mourtzakis and colleagues (2008) using single abdominal CT images from 43 ACP and were compared with whole-body DXA scans using Spearman correlations and Bland-Altman analyses. Despite a moderate to high correlation between the actual (DXA) and predicted (CT) values for FM (rho = 0.93; p ≤ 0.001), FFM (rho = 0.78; p ≤ 0.001), and ASM mass (rho = 0.70; p ≤ 0.001), Bland-Altman analyses revealed large range-of-agreement differences between the 2 methods (29.39 kg for FFM, 15.47 kg for FM, and 3.99 kg for ASM mass). Based on the magnitude of these differences, we concluded that prediction equations using single abdominal CT images have poor accuracy, cannot be considered as surrogates for DXA, and may have limited clinical utility.

  6. Increased Muscular 5α-Dihydrotestosterone in Response to Resistance Training Relates to Skeletal Muscle Mass and Glucose Metabolism in Type 2 Diabetic Rats.

    Naoki Horii

    Full Text Available Regular resistance exercise induces skeletal muscle hypertrophy and improvement of glycemic control in type 2 diabetes patients. Administration of dehydroepiandrosterone (DHEA, a sex steroid hormone precursor, increases 5α-dihydrotestosterone (DHT synthesis and is associated with improvements in fasting blood glucose level and skeletal muscle hypertrophy. Therefore, the aim of this study was to investigate whether increase in muscle DHT levels, induced by chronic resistance exercise, can contribute to skeletal muscle hypertrophy and concomitant improvement of muscular glucose metabolism in type 2 diabetic rats. Male 20-week-old type 2 diabetic rats (OLETF were randomly divided into 3 groups: sedentary control, resistance training (3 times a week on alternate days for 8 weeks, or resistance training with continuous infusion of a 5α-reductase inhibitor (n = 8 each group. Age-matched, healthy nondiabetic Long-Evans Tokushima Otsuka (LETO rats (n = 8 were used as controls. The results indicated that OLETF rats showed significant decrease in muscular DHEA, free testosterone, DHT levels, and protein expression of steroidogenic enzymes, with loss of skeletal muscle mass and hyperglycemia, compared to that of LETO rats. However, 8-week resistance training in OLETF rats significantly increased the levels of muscle sex steroid hormones and protein expression of steroidogenic enzymes with a concomitant increase in skeletal muscle mass, improved fasting glucose level, and insulin sensitivity index. Moreover, resistance training accelerated glucose transporter-4 (GLUT-4 translocation and protein kinase B and C-ζ/λ phosphorylation. Administering the 5α-reductase inhibitor in resistance-trained OLETF rats resulted in suppression of the exercise-induced effects on skeletal muscle mass, fasting glucose level, insulin sensitivity index, and GLUT-4 signaling, with a decline in muscular DHT levels. These findings suggest that resistance training

  7. Influence of amino acids, dietary protein, and physical activity on muscle mass development in humans

    Dideriksen, Kasper; Reitelseder, Søren; Holm, Lars

    2013-01-01

    intake. Ingestion of excess protein exerts an unwanted load to the body and therefore, it is important to find the least amount of protein that provides the maximal hypertrophic stimulus. Hence, research has focused on revealing the relationship between protein intake (dose) and its resulting stimulation...... response dependent on the characteristics of the protein ingested. The effect of protein intake on muscle protein accretion can further be stimulated by prior exercise training. In the ageing population, physical training may counteract the development of "anabolic resistance" and restore the beneficial...

  8. Influence of combined resistance training and healthy diet on muscle mass in healthy elderly women: a randomized controlled trial.

    Strandberg, Emelie; Edholm, Peter; Ponsot, Elodie; Wåhlin-Larsson, Britta; Hellmén, Erik; Nilsson, Andreas; Engfeldt, Peter; Cederholm, Tommy; Risérus, Ulf; Kadi, Fawzi

    2015-10-15

    The delivery of efficient nonpharmacological treatment to prevent the loss of muscle mass in older adults is a major challenge, and information on the combined effects of training and diet is particularly important. Here we aimed to evaluate the effects of 24 wk of resistance training combined with a healthy dietary approach (n-6/n-3 ratio healthy and physically active older women (65-70 years). The three-armed randomized controlled trial included a resistance training + healthy diet group (RT-HD), a resistance training group (RT), and controls (CON). All subjects included in the study were physically active and had low levels of serum inflammatory markers. In accordance with the dietary goals, the n-6/n-3 ratio dietary intake significantly decreased only in RT-HD by 42%. An increase in 1 repetition maximum in leg extension occurred in RT (+20.4%) and RT-HD (+20.8%), but not in CON. Interestingly, leg lean mass significantly increased only in RT-HD (+1.8%). While there were no changes in serum C-reactive protein and IL-6 levels, a significant decrease in serum level of the pro-inflammatory precursor arachidonic acid (-5.3 ± 9.4%) together with an increase in serum n-3 docosahexaenoic acid (+8.3%) occurred only in RT-HD. Altogether, this study demonstrates that the effects of resistance training on muscle mass in healthy older adults can be optimized by the adoption of a healthy diet. Copyright © 2015 the American Physiological Society.

  9. Strong Relation between Muscle Mass Determined by D3-creatine Dilution, Physical Performance and Incidence of Falls and Mobility Limitations in a Prospective Cohort of Older Men.

    Cawthon, Peggy M; Orwoll, Eric S; Peters, Katherine E; Ensrud, Kristine E; Cauley, Jane A; Kado, Deborah M; Stefanick, Marcia L; Shikany, James M; Strotmeyer, Elsa S; Glynn, Nancy W; Caserotti, Paolo; Shankaran, Mahalakshmi; Hellerstein, Marc; Cummings, Steven R; Evans, William J

    2018-06-12

    Direct assessment of skeletal muscle mass in older adults is clinically challenging. Relationships between lean mass and late-life outcomes have been inconsistent. The D3-creatine dilution method provides a direct assessment of muscle mass. Muscle mass was assessed by D3-creatine (D3Cr) dilution in 1,382 men (mean age, 84.2 yrs). Participants completed the Short Physical Performance Battery (SPPB); usual walking speed (6 meters); and DXA lean mass. Men self-reported mobility limitations (difficulty walking 2-3 blocks or climbing 10 steps); recurrent falls (2+); and serious injurious falls in the subsequent year. Across quartiles of D3Cr muscle mass/body mass, multivariate linear models calculated means for SPPB and gait speed; multivariate logistic models calculated odds ratios for incident mobility limitations or falls. Compared to men in the highest quartile, those in the lowest quartile of D3Cr muscle mass/body mass had slower gait speed (Q1: 1.04 vs Q4: 1.17 m/s); lower SPPB (Q1: 8.4 vs Q4: 10.4 points); greater likelihood of incident serious injurious falls (OR Q1 vs Q4: 2.49, 95% CI: 1.37, 4.54); prevalent mobility limitation (OR Q1 vs Q4,: 6.1, 95%CI: 3.7, 10.3) and incident mobility limitation (OR Q1 vs Q4: 2.15 95% CI: 1.42, 3.26); p for trend strongly related to physical performance, mobility and incident injurious falls in older me.

  10. Age-associated declines in muscle mass, strength, power, and physical performance: impact on fear of falling and quality of life.

    Trombetti, A; Reid, K F; Hars, M; Herrmann, F R; Pasha, E; Phillips, E M; Fielding, R A

    2016-02-01

    This 3-year longitudinal study among older adults showed that declining muscle mass, strength, power, and physical performance are independent contributing factors to increased fear of falling, while declines of muscle mass and physical performance contribute to deterioration of quality of life. Our findings reinforce the importance of preserving muscle health with advancing age. The age-associated loss of skeletal muscle quantity and function are critical determinants of independent physical functioning in later life. Longitudinal studies investigating how decrements in muscle components of sarcopenia impact fear of falling (FoF) and quality of life (QoL) in older adults are lacking. Twenty-six healthy older subjects (age, 74.1 ± 3.7; Short Physical Performance Battery (SPPB) score ≥10) and 22 mobility-limited older subjects (age, 77.2 ± 4.4; SPPB score ≤9) underwent evaluations of lower extremity muscle size and composition by computed tomography, strength and power, and physical performance at baseline and after 3-year follow-up. The Falls Efficacy Scale (FES) and Short Form-36 questionnaire (SF-36) were also administered at both timepoints to assess FoF and QoL, respectively. At 3-year follow-up, muscle cross-sectional area (CSA) (p < 0.013) and power decreased (p < 0.001), while intermuscular fat infiltration increased (p < 0.001). These decrements were accompanied with a longer time to complete 400 m by 22 ± 46 s (p < 0.002). Using linear mixed-effects regression models, declines of muscle CSA, strength and power, and SPPB score were associated with increased FES score (p < 0.05 for each model). Reduced physical component summary score of SF-36 over follow-up was independently associated with decreased SPPB score (p < 0.020), muscle CSA (p < 0.046), and increased 400 m walk time (p < 0.003). In older adults with and without mobility limitations, declining muscle mass, strength, power, and physical

  11. Prolonged Adaptation to a Low or High Protein Diet Does Not Modulate Basal Muscle Protein Synthesis Rates - A Substudy.

    Rick Hursel

    Full Text Available Based on controlled 36 h experiments a higher dietary protein intake causes a positive protein balance and a negative fat balance. A positive net protein balance may support fat free mass accrual. However, few data are available on the impact of more prolonged changes in habitual protein intake on whole-body protein metabolism and basal muscle protein synthesis rates.To assess changes in whole-body protein turnover and basal muscle protein synthesis rates following 12 weeks of adaptation to a low versus high dietary protein intake.A randomized parallel study was performed in 40 subjects who followed either a high protein (2.4 g protein/kg/d or low protein (0.4 g protein/kg/d energy-balanced diet (30/35/35% or 5/60/35% energy from protein/carbohydrate/fat for a period of 12 weeks. A subgroup of 7 men and 8 women (body mass index: 22.8±2.3 kg/m2, age: 24.3±4.9 y were selected to evaluate the impact of prolonged adaptation to either a high or low protein intake on whole body protein metabolism and basal muscle protein synthesis rates. After the diet, subjects received continuous infusions with L-[ring-2H5]phenylalanine and L-[ring-2H2]tyrosine in an overnight fasted state, with blood samples and muscle biopsies being collected to assess post-absorptive whole-body protein turnover and muscle protein synthesis rates in vivo in humans.After 12 weeks of intervention, whole-body protein balance in the fasted state was more negative in the high protein treatment when compared with the low protein treatment (-4.1±0.5 vs -2.7±0.6 μmol phenylalanine/kg/h;P<0.001. Whole-body protein breakdown (43.0±4.4 vs 37.8±3.8 μmol phenylalanine/kg/h;P<0.03, synthesis (38.9±4.2 vs 35.1±3.6 μmol phenylalanine/kg/h;P<0.01 and phenylalanine hydroxylation rates (4.1±0.6 vs 2.7±0.6 μmol phenylalanine/kg/h;P<0.001 were significantly higher in the high vs low protein group. Basal muscle protein synthesis rates were maintained on a low vs high protein diet (0.042

  12. High efficiency nebulization for helium inductively coupled plasma mass spectrometry

    Jorabchi, Kaveh; McCormick, Ryan; Levine, Jonathan A.; Liu Huiying; Nam, S.-H.; Montaser, Akbar

    2006-01-01

    A pneumatically-driven, high efficiency nebulizer is explored for helium inductively coupled plasma mass spectrometry. The aerosol characteristics and analyte transport efficiencies of the high efficiency nebulizer for nebulization with helium are measured and compared to the results obtained with argon. Analytical performance indices of the helium inductively coupled plasma mass spectrometry are evaluated in terms of detection limits and precision. The helium inductively coupled plasma mass spectrometry detection limits obtained with the high efficiency nebulizer at 200 μL/min are higher than those achieved with the ultrasonic nebulizer consuming 2 mL/min solution, however, precision is generally better with high efficiency nebulizer (1-4% vs. 3-8% with ultrasonic nebulizer). Detection limits with the high efficiency nebulizer at 200 μL/min solution uptake rate approach those using ultrasonic nebulizer upon efficient desolvation with a heated spray chamber followed by a Peltier-cooled multipass condenser

  13. Mass terms in effective theories of high density quark matter

    Schäfer, T.

    2002-04-01

    We study the structure of mass terms in the effective theory for quasiparticles in QCD at high baryon density. To next-to-leading order in the 1/pF expansion we find two types of mass terms: chirality conserving two-fermion operators and chirality violating four-fermion operators. In the effective chiral theory for Goldstone modes in the color-flavor-locked (CFL) phase the former terms correspond to effective chemical potentials, while the latter lead to Lorentz invariant mass terms. We compute the masses of Goldstone bosons in the CFL phase, confirming earlier results by Son and Stephanov as well as Bedaque and Schäfer. We show that to leading order in the coupling constant g there is no antiparticle gap contribution to the mass of Goldstone modes, and that our results are independent of the choice of gauge.

  14. Locomotor muscle fatigue does not alter oxygen uptake kinetics during high-intensity exercise

    James Hopker

    2016-10-01

    Full Text Available The slow component (VO2sc that develops during high-intensity aerobic exercise is thought to be strongly associated with locomotor muscle fatigue. We sought to experimentally test this hypothesis by pre-fatiguing the locomotor muscles used during subsequent high-intensity cycling exercise. Over two separate visits, eight healthy male participants were asked to either perform a non-metabolically stressful 100 intermittent drop-jumps protocol (pre fatigue condition or rest for 33 minutes (control condition according to a random and counterbalanced order. Locomotor muscle fatigue was quantified with 6-second maximal sprints at a fixed pedaling cadence of 90 rev·min-1. Oxygen kinetics and other responses (heart rate, capillary blood lactate concentration and rating of perceived exertion, RPE were measured during two subsequent bouts of 6 min cycling exercise at 50% of the delta between the lactate threshold and VO2max determined during a preliminary incremental exercise test. All tests were performed on the same cycle ergometer. Despite significant locomotor muscle fatigue (P = 0.03, the VO2sc was not significantly different between the pre fatigue (464 ± 301 mL·min-1 and the control (556 ± 223 mL·min-1 condition (P = 0.50. Blood lactate response was not significantly different between conditions (P = 0.48 but RPE was significantly higher following the pre-fatiguing exercise protocol compared with the control condition (P < 0.01 suggesting higher muscle recruitment. These results demonstrate experimentally that locomotor muscle fatigue does not significantly alter the VO2 kinetic response to high intensity aerobic exercise, and challenge the hypothesis that the VO2sc is strongly associated with locomotor muscle fatigue.

  15. Oxidative DNA damage and repair in skeletal muscle of humans exposed to high-altitude hypoxia

    Lundby, Carsten; Pilegaard, Henriette; van Hall, Gerrit

    2003-01-01

    Recent research suggests that high-altitude hypoxia may serve as a model for prolonged oxidative stress in healthy humans. In this study, we investigated the consequences of prolonged high-altitude hypoxia on the basal level of oxidative damage to nuclear DNA in muscle cells, a major oxygen-consuming...

  16. The obesity paradox in men with coronary heart disease and heart failure: the role of muscle mass and leptin.

    Wannamethee, S Goya; Shaper, A Gerald; Whincup, Peter H; Lennon, Lucy; Papacosta, Olia; Sattar, Naveed

    2014-01-15

    We have investigated the role of muscle mass, natriuretic peptides and adipokines in explaining the obesity paradox. The obesity paradox relates to the association between obesity and increased survival in patients with coronary heart disease (CHD) or heart failure (HF). Prospective study of 4046 men aged 60-79 years followed up for a mean period of 11 years, during which 1340 deaths occurred. The men were divided according to the presence of doctor diagnosed CHD and HF: (i) no CHD or HF ii), with CHD (no HF) and (iii) with HF. Overweight (BMI 25-9.9 kg/m(2)) and obesity (BMI ≥ 30 kg/m(2)) were associated with lower mortality risk compared to men with normal weight (BMI 18.5-24.9 kg/m(2)) in those with CHD [hazards ratio (HR) 0.71 (0.56,0.91) and 0.77 (0.57,1.04); p=0.04 for trend] and in those with HF [HR 0.57 (0.28,1.16) and 0.41 (0.16,1.09; p=0.04 for trend). Adjustment for muscle mass and NT-proBNP attenuated the inverse association in those with CHD (no HF) [HR 0.78 (0.61,1.01) and 0.96 (0.68,1.36) p=0.60 for trend) but made minor differences to those with HF [p=0.05]. Leptin related positively to mortality in men without HF but inversely to mortality in those with HF; adjustment for leptin abolished the BMI mortality association in men with HF [HR 0.82 (0.31,2.20) and 0.99 (0.27,3.71); p=0.98 for trend]. The lower mortality risk associated with excess weight in men with CHD without HF may be due to higher muscle mass. In men with HF, leptin (possibly reflecting cachexia) explain the inverse association. Copyright © 2013. Published by Elsevier Ireland Ltd.

  17. Comparison between body mass index, triceps skin fold thickness and mid-arm muscle circumference in Saudi adolescents

    Abdalkhail, B.; Shawky, S.

    2002-01-01

    Adolescence is an important period in an individual's life. Overweight and obesity are fraught with several health problems even late in life. The objective of this study was estimate the overweight, obesity, body fat and muscle content of Saudi adolescents as compared to a recognized reference population. Data were collected from a sample of Saudi adolescents in Jeddah from 42 boys' and 42 girls' school during the month of April 2000. Data collection was done by personal interviews to collect sociodemograhic factors and by direct measurement of weight, height, triceps skin fold thickness (TSF) and mid-arm circumference (MAC). The 50th, 85th and 95th percentiles(P50, P85 and P95) for body mass index (BMI) and triceps skin fold thickness (TSF) were taken, then the 50th, 90th, and 95th percentiles (P50, P90 and P95) for the mid-arm muscle circumference (MAMC) were calculated. These measurements were compared with corresponding values of the National Health and Nutrition Examination Survey I (NHANES I). The P85 and P95 for the BMI and TSF were higher for Saudi adolescents than the NHANES I and the difference was wider for P95. Conversely, there was a lower MAMC at P90 and P95thane the NHANES I reference population curves. The lower MAMC curves were less marked in girls than in boys. On the other hand Saudi boys and girls showed on average similar body mass index indicated by MBI at P50, which was misleading, since those adolescents showing similar body mass index had more fatness than of average reference population indicated by TSF and P50, and less muscularity on average than reference population indicated MAMC at P-50. Overweight and obesity with increased body fat content and decreased body muscle content appear to be widespread among Saudi adolescents even among those adolescents showing average body index. Public health interventions are required to improve quality of food, encourage physical, activity and exercise, as well as correct the perception of

  18. High mass resolution time of flight mass spectrometer for measuring products in heterogeneous catalysis in highly sensitive microreactors

    Andersen, Thomas; Jensen, Robert; Christensen, M. K.

    2012-01-01

    We demonstrate a combined microreactor and time of flight system for testing and characterization of heterogeneous catalysts with high resolution mass spectrometry and high sensitivity. Catalyst testing is performed in silicon-based microreactors which have high sensitivity and fast thermal...

  19. Associations of dietary patterns with bone mass, muscle strength and balance in a cohort of Australian middle-aged women.

    Wu, Feitong; Wills, Karen; Laslett, Laura L; Oldenburg, Brian; Jones, Graeme; Winzenberg, Tania

    2017-10-01

    Influences of dietary patterns on musculoskeletal health are poorly understood in middle-aged women. This cross-sectional analysis from a cohort of 347 women (aged 36-57 years) aimed to examine associations between dietary patterns and musculoskeletal health outcomes in middle-aged women. Diet was measured by the Cancer Council of Victoria FFQ. Total body bone mineral content (TB BMC), femoral neck and lumbar spine bone density (dual-energy X-ray absorptiometry), lower limbs muscle strength (LMS) and balance tests (timed up and go test, step test, functional reach test (FRT) and lateral reach test) were also measured. Exploratory factor analysis was used to identify dietary patterns and scores for each pattern generated using factor loadings with absolute values ≥0·20. Associations between food pattern scores and musculoskeletal outcomes were assessed using multivariable linear regression. Three dietary patterns were identified: 'Healthy' (high consumption of a plant-based diet - vegetables, legumes, fruit, tomatoes, nuts, snacks, garlic, whole grains and low intake of high-fat dairy products), 'high protein, high fat' (red meats, poultry, processed meats, potatoes, cruciferous and dark-yellow vegetables, fish, chips, spirits and high-fat dairy products) and 'Processed foods' (high intakes of meat pies, hamburgers, beer, sweets, fruit juice, processed meats, snacks, spirits, pizza and low intake of cruciferous vegetables). After adjustment for confounders, Healthy pattern was positively associated with LMS, whereas Processed foods pattern was inversely associated with TB BMC and FRT. The associations were not significant after accounting for multiple comparisons. There were no associations with any other outcomes. These results suggest that maintaining a healthy diet could contribute to bone acquisition, muscle strength and balance in adult life. However, while they provide some support for further investigating dietary strategies for prevention of age

  20. Influence of Nordic Walking Training on Muscle Strength and the Electromyographic Activity of the Lower Body in Women With Low Bone Mass

    Ossowski Zbigniew

    2016-06-01

    Full Text Available Introduction. Osteoporosis and osteopenia are related to changes in the quantity and quality of skeletal muscle and contribute to a decreased level of muscle strength. The purpose of this study was to evaluate the impact of Nordic walking training on muscle strength and the electromyographic (EMG activity of the lower body in women with low bone mass. Material and methods. The participants of the study were 27 women with low bone mass. The sample was randomly divided into two groups: a control group and an experimental group. Women from the experimental group participated in 12 weeks of regular Nordic walking training. Functional strength was assessed with a 30-second chair stand test. The EMG activities of the gluteus maximus (GMax, rectus femoris (RF, biceps femoris (BF, soleus (SOL, and lumbar (LB muscles were measured using a surface electromyogram. Results. Nordic walking training induced a significant increase in the functional strength (p = 0.006 of the lower body and activity of GMax (p = 0.013 and a decrease in body mass (p = 0.006 in women with reduced bone mass. There was no statistically significant increase in the EMG activities of the RF, BF, SOL, or LB muscles. The study did not indicate any significant changes in functional muscle strength, the EMG activity of the lower body, or anthropometry in women from the control group. Conclusions. Nordic walking training induces positive changes in lower body strength and the electromyographic activity of the gluteus maximus as well as a decrease in body mass in women with low bone mass.

  1. Ratio of dietary ω-3 and ω-6 fatty acids-independent determinants of muscle mass-in hemodialysis patients with diabetes.

    Wong, Te-Chih; Chen, Yu-Tong; Wu, Pei-Yu; Chen, Tzen-Wen; Chen, Hsi-Hsien; Chen, Tso-Hsiao; Hsu, Yung-Ho; Yang, Shwu-Huey

    2016-09-01

    ω-3 and ω-6 polyunsaturated fatty acids (PUFAs) are essential nutrients in the human diet and possibly affect muscle mass. We evaluated the association between the dietary ratios of ω-3 and ω-6 PUFAs and muscle mass, indicated as skeletal muscle mass (SMM) and appendicular skeletal muscle mass (ASM), in patients with diabetes undergoing hemodialysis (HD). In this cross-sectional study, data on 69 patients with diabetes who underwent standard HD therapy were analyzed. For estimating muscle mass, anthropometric and bioelectrical impedance analyses were conducted following dialysis. In addition, routine laboratory and 3-d dietary data were obtained. The adequate intake (AI) cut-off for ω-3 PUFAs was 1.6 g/d and 1.1 g/d for male and female patients, respectively. The average age of the participants was 63.0 ± 10.4 y. The mean ratios of ω-3/ω-6 PUFA intake, ω-6/ω-3 PUFA intake, SMM, and ASM of the patients were 0.13 ± 0.07, 9.4 ± 6.4, 24.6 ± 5.4 kg, and 18.3 ± 4.6 kg, respectively. Patients who had AI of ω-3 PUFAs had significantly higher SMM and ASM than did their counterparts. Linear and stepwise multivariable adjustment analyses revealed that insulin resistance and the ω-6/ω-3 PUFA ratio were the independent deleterious determinants of ASM normalized to height in HD patients. Patients with AI of ω-3 PUFAs had total-body SMM and ASM that were more appropriate. A higher dietary ratio of ω-6/ω-3 PUFAs was associated with reduced muscle mass in HD patients. Copyright © 2016 Elsevier Inc. All rights reserved.

  2. Search for high mass resonances in dielectron final state

    CMS Collaboration

    2018-01-01

    A search for high mass resonances in the dielectron final state is performed using proton-proton collision data at a center-of-mass energy of $13~\\mathrm{TeV}$ collected by the CMS experiment at the LHC in 2017. The integrated luminosity corresponds to $41~\\mathrm{fb}^{-1}$. No evidence for a significant deviation from standard model expectation is observed. The sensitivity of the search is increased by combining these data with a previously analysed set of data obtained in 2016 and corresponding to a luminosity of $36~\\mathrm{fb}^{-1}$. Upper bounds are set on the masses of hypothetical particles that arise in new-physics scenarios.

  3. High mass accuracy and high mass resolving power FT-ICR secondary ion mass spectrometry for biological tissue imaging

    Smith, D.F.; Kiss, A.; Leach, F.E.; Robinson, E.W.; Paša-Tolić, L.; Heeren, R.M.A.

    2013-01-01

    Biological tissue imaging by secondary ion mass spectrometry has seen rapid development with the commercial availability of polyatomic primary ion sources. Endogenous lipids and other small bio-molecules can now be routinely mapped on the sub-micrometer scale. Such experiments are typically

  4. Implications of the absence of high-mass radion signals

    Ahmed, Aqeel; Dillon, Barry M.; Grzadkowski, Bohdan; Gunion, John F.; Jiang, Yun

    2017-05-01

    Given the disappearance of the 750 GeV diphoton LHC signal and the absence of signals at high mass in this and other channels, significant constraints on the mixed Higgs-radion of the five-dimensional Randall-Sundrum model arise. By combining all channels, these constraints place a significant radion-mass-dependent lower bound on the radion vacuum expectation value that is fairly independent of the amount of Higgs radion mixing.

  5. High Resolution Mass Spectrometry of Polyfluorinated Polyether-Based Formulation

    Dimzon, Ian Ken; Trier, Xenia; Frömel, Tobias

    2016-01-01

    High resolution mass spectrometry (HRMS) was successfully applied to elucidate the structure of a polyfluorinated polyether (PFPE)-based formulation. The mass spectrum generated from direct injection into the MS was examined by identifying the different repeating units manually and with the aid o......-fluorinated polymers. The information from MS is essential in studying the physico-chemical properties of PFPEs and can help in assessing the risks they pose to the environment and to human health. Graphical Abstract ᅟ....

  6. High Intensity Exercise in Multiple Sclerosis: Effects on Muscle Contractile Characteristics and Exercise Capacity, a Randomised Controlled Trial.

    Inez Wens

    Full Text Available Low-to-moderate intensity exercise improves muscle contractile properties and endurance capacity in multiple sclerosis (MS. The impact of high intensity exercise remains unknown.Thirty-four MS patients were randomized into a sedentary control group (SED, n = 11 and 2 exercise groups that performed 12 weeks of a high intensity interval (HITR, n = 12 or high intensity continuous cardiovascular training (HCTR, n = 11, both in combination with resistance training. M.vastus lateralis fiber cross sectional area (CSA and proportion, knee-flexor/extensor strength, body composition, maximal endurance capacity and self-reported physical activity levels were assessed before and after 12 weeks.Compared to SED, 12 weeks of high intensity exercise increased mean fiber CSA (HITR: +21 ± 7%, HCTR: +23 ± 5%. Furthermore, fiber type I CSA increased in HCTR (+29 ± 6%, whereas type II (+23 ± 7% and IIa (+23 ± 6%, CSA increased in HITR. Muscle strength improved in HITR and HCTR (between +13 ± 7% and +45 ± 20% and body fat percentage tended to decrease (HITR: -3.9 ± 2.0% and HCTR: -2.5 ± 1.2%. Furthermore, endurance capacity (Wmax +21 ± 4%, time to exhaustion +24 ± 5%, VO2max +17 ± 5% and lean tissue mass (+1.4 ± 0.5% only increased in HITR. Finally self-reported physical activity levels increased 73 ± 19% and 86 ± 27% in HCTR and HITR, respectively.High intensity cardiovascular exercise combined with resistance training was safe, well tolerated and improved muscle contractile characteristics and endurance capacity in MS.ClinicalTrials.gov NCT01845896.

  7. Effects of High-Intensity Blood Flow Restriction Exercise on Muscle Fatigue

    Neto Gabriel R.

    2014-07-01

    Full Text Available Strength training combined with blood flow restriction (BFR have been used to improve the levels of muscle adaptation. The aim of this paper was to investigate the acute effect of high intensity squats with and without blood flow restriction on muscular fatigue levels. Twelve athletes (aged 25.95 ± 0.84 years were randomized into two groups: without Blood Flow Restriction (NFR, n = 6 and With Blood Flow Restriction (WFR, n = 6 that performed a series of free weight squats with 80% 1-RM until concentric failure. The strength of the quadriceps extensors was assessed in a maximum voluntary isometric contraction integrated to signals from the surface electromyogram. The average frequency showed significant reductions in the WFR group for the vastus lateralis and vastus medialis muscles, and intergroup only for the vastus medialis. In conclusion, a set of squats at high intensity with BFR could compromise muscle strength immediately after exercise, however, differences were not significant between groups.

  8. High resolution study of high mass pairs and high transverse momentum particles

    Smith, S.R.

    1983-01-01

    Preliminary experiments involving the high resolution spectrometer (experiment 605) at Fermilab are described. The spectrometer is designed for the study of pairs of particles at large invariant masses and single particles at large transverse momenta. A number of applications of the apparatus in the study of Drell-Yan processes, e.g. transverse momentum measurement, are discussed

  9. Pre- and post-operative evaluation of ventricular function, muscle mass and valve morphology by MR tomography in Ebstein's anomaly

    Gutberlet, M.; Oellinger, H.; Amthauer, H.; Hoffmann, T.; Felix, R.; Ewert, P.; Nagdyman, N.; Lange, P.; Hetzer, R.

    2000-01-01

    Purpose: To evaluate the value of MRT with spin echo (SE) and CINE gradient echo (GE) sequences for the pre- and postoperative assessment of patients with Ebstein's anomaly. Methods: Twelve patients within the ages of four to 49 years (mean 22±12 years) were examined pre- (n=5) or postoperatively (n=7) after tricuspid valve reconstruction with a 1.5 T scanner. For the anatomical assessment, an ECG-gated transverse SE-sequence, for the assessment of valve morphology and function as well as for volumetry a CINE GE-sequence with retrospective gating was used. With the use of the multislice-multiphase technique, after summing up the manually outlined epi- and endocardial areas, endsystolic (ESV) and enddiastolic volumes (EDV), ejection fraction (EF), stroke volume (SV), and muscle mass (MM) were calculated for both ventricles. Results: The differentiation of the displaced parts of the tricuspid valve (TV) was insufficient with static SE, but was possible in all patients with CINE-MRT. Like in Doppler echocardiography, a qualitative assessment of tricuspid insufficiency was possible in CINE-MRT, the mean incompetence grade preoperative was 1.8 (±0.8), postoperative 0.7 (±0.5). The mean RV-EF in the preoperative group was 41.8% (±6.4), in the postoperative group 47.9% (±10.6), the mean LV-EF preoperative 47.4% (±8.5%), postoperative 63,0% (±9.4). Conclusion: CINE-MRT should rather be used than SE for the assessment of valve morphology. EF, muscle mass and tricuspid incompetence can also be calculated pre- and postoperative with CINE-MRT. (orig.) [de

  10. Impaired Bronchoprotection Is Not Induced by Increased Smooth Muscle Mass in Chronic Treatment In Vivo with Formoterol in Asthmatic Mouse Model

    W Luo

    2014-09-01

    Full Text Available Objective: Inhaling β2-adrenoceptor agonist is first-line asthma treatment, which is used for both acute relief and prevention of bronchoconstriction. However, chronic use of β-agonists results in impaired bronchoprotection and increasing occurrences of severe asthma exacerbation, even death in clinical practice. The mechanism of β-adrenoceptor hyposensitivity has not been thoroughly elucidated thus far. Bronchial smooth muscle contraction induces airway narrowing and also mediates airway inflammation. Moreover, bronchial smooth muscle mass significantly increases in asthmatics. We aimed to establish an asthmatic model that demonstrated that formoterol induced impaired bronchoprotection and to see whether increased smooth muscle mass played a role in it. Methods: We combined routine allergen challenging (seven weeks with repeated application of formoterol, formoterol plus budesonide or physiological saline in allergen-sensitized BALB/c mouse. The bronchoprotection mediated by β-agonist was measured in five consecutive weeks. Smooth muscle mass was shown by morphometric analysis, and α-actin expression was detected by western blot. Results: The trend of bronchoprotection was wavy in drug interventional groups, which initially increased and then decreased. Chronic treatment with formoterol significantly impaired bronchoprotection. According to the morphometric analysis and α-actin expression, no significant difference was detected in smooth muscle mass in all groups. Conclusion: This experiment successfully established that a chronic asthmatic mouse model, which manifested typical features of asthmatic patients, with chronic use of formoterol, results in a loss of bronchoprotection. No significant difference was detected in smooth muscle mass in all groups, which implied some subcellular signalling changes may be the key points.

  11. Ultra High-Mass Resolution Paper Spray by Fourier Transform Ion Cyclotron Resonance Mass Spectrometry

    Kevin D. Quinn

    2012-01-01

    Full Text Available Paper Spray Ionization is an atmospheric pressure ionization technique that utilizes an offline electro-osmotic flow to generate ions off a paper medium. This technique can be performed on a Bruker SolariX Fourier transform ion cyclotron resonance mass spectrometer by modifying the existing nanospray source. High-resolution paper spray spectra were obtained for both organic and biological samples to demonstrate the benefit of linking the technique with a high-resolution mass analyzer. Error values in the range 0.23 to 2.14 ppm were obtained for calf lung surfactant extract with broadband mass resolving power (m/Δm50% above 60,000 utilizing an external calibration standard.

  12. Magnetic resonance imaging of muscle tears

    De Smet, A.A.; Fisher, D.R.; Heiner, J.P.; Keene, J.S.

    1990-01-01

    Magnetic resonance scans were obtained on 17 patients with acute, subacute, or chronic muscle tears. These patients presented with complaints of persistent pain or a palpable mass. Magnetic resonance findings were characterized according to alterations in muscle shape and the presence of abnormal high signal within the injured muscle. These areas of high signal were noted on both T1-weighted and T2-weighted scans and were presumed to represent areas of intramuscular hemorrhage. (orig.)

  13. Locomotor Muscle Fatigue Does Not Alter Oxygen Uptake Kinetics during High-Intensity Exercise.

    Hopker, James G; Caporaso, Giuseppe; Azzalin, Andrea; Carpenter, Roger; Marcora, Samuele M

    2016-01-01

    The [Formula: see text] slow component ([Formula: see text]) that develops during high-intensity aerobic exercise is thought to be strongly associated with locomotor muscle fatigue. We sought to experimentally test this hypothesis by pre-fatiguing the locomotor muscles used during subsequent high-intensity cycling exercise. Over two separate visits, eight healthy male participants were asked to either perform a non-metabolically stressful 100 intermittent drop-jumps protocol (pre-fatigue condition) or rest for 33 min (control condition) according to a random and counterbalanced order. Locomotor muscle fatigue was quantified with 6-s maximal sprints at a fixed pedaling cadence of 90 rev·min -1 . Oxygen kinetics and other responses (heart rate, capillary blood lactate concentration and rating of perceived exertion, RPE) were measured during two subsequent bouts of 6 min cycling exercise at 50% of the delta between the lactate threshold and [Formula: see text] determined during a preliminary incremental exercise test. All tests were performed on the same cycle ergometer. Despite significant locomotor muscle fatigue ( P = 0.03), the [Formula: see text] was not significantly different between the pre-fatigue (464 ± 301 mL·min -1 ) and the control (556 ± 223 mL·min -1 ) condition ( P = 0.50). Blood lactate response was not significantly different between conditions ( P = 0.48) but RPE was significantly higher following the pre-fatiguing exercise protocol compared with the control condition ( P locomotor muscle fatigue does not significantly alter the [Formula: see text] kinetic response to high intensity aerobic exercise, and challenge the hypothesis that the [Formula: see text] is strongly associated with locomotor muscle fatigue.

  14. A 5-year cohort study of the effects of high protein intake on lean mass and BMC in elderly postmenopausal women.

    Meng, Xingqiong; Zhu, Kun; Devine, Amanda; Kerr, Deborah A; Binns, Colin W; Prince, Richard L

    2009-11-01

    Long-term effects of high dietary protein intake on muscle and bone structure in the elderly are not clear. The aim of this study was to investigate the relationship between baseline protein intake and lean mass and BMC 5 yr later in a cohort of elderly postmenopausal women. A total of 862 community-dwelling women 75 +/- 3 yr of age provided baseline data including nutrient intake assessed by a food frequency questionnaire. At 5 yr, upper arm muscle area (UAMA) and body composition using DXA were measured. Baseline protein intake was 81 +/- 28 g/d (1.2 +/- 0.4 g/kg/d), contributing 19 +/- 3% of total energy intake. There were positive correlations between baseline protein intake and whole body and appendicular bone-free lean mass and BMC (r = 0.14-0.18, p 87 g/d) had 5.4-6.0% higher whole body and appendicular lean mass and UAMA and 5.3-6.0% higher whole body and appendicular BMC. These effects remained after adjusting for potential confounders. However, the effect on BMC disappeared after further adjustment for lean mass. This study shows that high protein intake is associated with long-term beneficial effects on muscle mass and size and bone mass in elderly women. The protein effect on bone may be partly mediated by its effects on muscle.

  15. Purification and Crystallization of Murine Myostatin: A Negative Regulator of Muscle Mass

    Hong, Young S.; Adamek, Daniel; Bridge, Kristi; Malone, Christine C.; Young, Ronald B.; Miller, Teresa; Karr, Laurel

    2004-01-01

    Myostatin (MSTN) has been crystallized and its preliminary X-ray diffraction data were collected. MSTN is a negative regulator of muscle growt/differentiation and suppressor of fat accumulation. It is a member of TGF-b family of proteins. Like other members of this family, the regulation of MSTN is critically tied to its process of maturation. This process involves the formation of a homodimer followed by two proteolytic steps. The first proteolytic cleavage produces a species where the n-terminal portion of the dimer is covalently separated from, but remains non-covalently bound to, the c-terminal, functional, portion of the protein. The protein is activated upon removal of the n-terminal "pro-segment" by a second n-terminal proteolytic cut by BMP-1 in vivo, or by acid treatment in vitro. Understanding the structural nature and physical interactions involved in these regulatory processes is the objective of our studies. Murine MSTN was purified from culture media of genetically engineered Chinese Hamster Ovary cells by multicolumn purification process and crystallized using the vapor diffusion method.

  16. Utility and reliability of non-invasive muscle function tests in high-fat-fed mice.

    Martinez-Huenchullan, Sergio F; McLennan, Susan V; Ban, Linda A; Morsch, Marco; Twigg, Stephen M; Tam, Charmaine S

    2017-07-01

    What is the central question of this study? Non-invasive muscle function tests have not been validated for use in the study of muscle performance in high-fat-fed mice. What is the main finding and its importance? This study shows that grip strength, hang wire and four-limb hanging tests are able to discriminate the muscle performance between chow-fed and high-fat-fed mice at different time points, with grip strength being reliable after 5, 10 and 20 weeks of dietary intervention. Non-invasive tests are commonly used for assessing muscle function in animal models. The value of these tests in obesity, a condition where muscle strength is reduced, is unclear. We investigated the utility of three non-invasive muscle function tests, namely grip strength (GS), hang wire (HW) and four-limb hanging (FLH), in C57BL/6 mice fed chow (chow group, n = 48) or a high-fat diet (HFD group, n = 48) for 20 weeks. Muscle function tests were performed at 5, 10 and 20 weeks. After 10 and 20 weeks, HFD mice had significantly reduced GS (in newtons; mean ± SD: 10 weeks chow, 1.89 ± 0.1 and HFD, 1.79 ± 0.1; 20 weeks chow, 1.99 ± 0.1 and HFD, 1.75 ± 0.1), FLH [in seconds per gram body weight; median (interquartile range): 10 weeks chow, 2552 (1337-4964) and HFD, 1230 (749-1994); 20 weeks chow, 2048 (765-3864) and HFD, 1036 (717-1855)] and HW reaches [n; median (interquartile range): 10 weeks chow, 4 (2-5) and HFD, 2 (1-3); 20 weeks chow, 3 (1-5) and HFD, 1 (0-2)] and higher falls [n; median (interquartile range): 10 weeks chow, 0 (0-2) and HFD, 3 (1-7); 20 weeks chow, 1 (0-4) and HFD, 8 (5-10)]. Grip strength was reliable in both dietary groups [intraclass correlation coefficient (ICC) = 0.5-0.8; P tests are valuable and reliable tools for assessment of muscle strength and function in high-fat-fed mice. © 2017 The Authors. Experimental Physiology © 2017 The Physiological Society.

  17. Visualization of dynamic change in contraction-induced lipid composition in mouse skeletal muscle by matrix-assisted laser desorption/ionization imaging mass spectrometry.

    Goto-Inoue, Naoko; Manabe, Yasuko; Miyatake, Shouta; Ogino, Shinya; Morishita, Ai; Hayasaka, Takahiro; Masaki, Noritaka; Setou, Mitsutoshi; Fujii, Nobuharu L

    2012-06-01

    Lipids in skeletal muscle play a fundamental role both in normal muscle metabolism and in disease states. Skeletal muscle lipid accumulation is associated with several chronic metabolic disorders, including obesity, insulin resistance, and type 2 diabetes. However, it is poorly understood whether the lipid composition of skeletal muscle changes by contraction, due to the complexity of lipid molecular species. In this study, we used matrix-assisted laser desorption/ionization imaging mass spectrometry (MALDI-IMS) to investigate changes in skeletal muscle lipid composition induced by contraction. We successfully observed the reduction of diacylglycerol and triacylglycerol, which are generally associated with muscle contraction. Interestingly, we found the accumulation of some saturated and mono-unsaturated fatty acids and poly-unsaturated fatty acids containing phosphatidylcholine in contracted muscles. Moreover, the distributions of several types of lipid were changed by contraction. Our results show that changes in the lipid amount, lipid composition, and energy metabolic activity can be evaluated in each local spot of cells and tissues at the same time using MALDI-IMS. In conclusion, MALDI-IMS is a powerful tool for studying lipid changes associated with contractions.

  18. Rotation of the Mass Donors in High-mass X-ray Binaries and Symbiotic Stars

    K. Stoyanov

    2015-02-01

    Full Text Available Our aim is to investigate the tidal interaction in High-mass X-ray Binaries and Symbiotic stars in order to determine in which objects the rotation of the mass donors is synchronized or pseudosynchronized with the orbital motion of the compact companion. We find that the Be/X-ray binaries are not synchronized and the orbital periods of the systems are greater than the rotational periods of the mass donors. The giant and supergiant High-mass X-ray binaries and symbiotic stars are close to synchronization. We compare the rotation of mass donors in symbiotics with the projected rotational velocities of field giants and find that the M giants in S-type symbiotics rotate on average 1.5 times faster than the field M giants. We find that the projected rotational velocity of the red giant in symbiotic star MWC 560 is v sin i= 8.2±1.5 km.s−1, and estimate its rotational period to be Prot<>/sub = 144 - 306 days. Using the theoretical predictions of tidal interaction and pseudosynchronization, we estimate the orbital eccentricity e = 0.68 − 0.82.

  19. Metabolomic Analysis of Oxidative and Glycolytic Skeletal Muscles by Matrix-Assisted Laser Desorption/IonizationMass Spectrometric Imaging (MALDI MSI)

    Tsai, Yu-Hsuan; Garrett, Timothy J.; Carter, Christy S.; Yost, Richard A.

    2015-06-01

    Skeletal muscles are composed of heterogeneous muscle fibers that have different physiological, morphological, biochemical, and histological characteristics. In this work, skeletal muscles extensor digitorum longus, soleus, and whole gastrocnemius were analyzed by matrix-assisted laser desorption/ionization mass spectrometry to characterize small molecule metabolites of oxidative and glycolytic muscle fiber types as well as to visualize biomarker localization. Multivariate data analysis such as principal component analysis (PCA) and partial least squares discriminant analysis (PLS-DA) were performed to extract significant features. Different metabolic fingerprints were observed from oxidative and glycolytic fibers. Higher abundances of biomolecules such as antioxidant anserine as well as acylcarnitines were observed in the glycolytic fibers, whereas taurine and some nucleotides were found to be localized in the oxidative fibers.

  20. Impact of high intensity exercise on muscle morphology in EAE rats

    Wens, I; Dalgas, U; Verboven, K

    2015-01-01

    paralysis (experiment 2, n=40), isokinetic foot extensor strength, cross sectional area (CSA) of tibialis anterior (TA), extensor digitorum longus (EDL) and soleus (SOL) and brain-derived neurotrophic factor (BDNF) levels were assessed. EAE reduced muscle fiber CSA of TA, EDL and SOL. In general, exercise......The impact of high-intensity exercise on disease progression and muscle contractile properties in experimental autoimmune encephalomyelitis (EAE) remains unclear. Control (CON) and EAE rats were divided into sedentary and exercise groups. Before onset (experiment 1, n=40) and after hindquarter...... was not able to affect CSA, whereas it delayed hindquarter paralysis peak. CON muscle work peaked and declined, while it remained stable in EAE. BDNF-responses were not affected by EAE or exercise. In conclusion, EAE affected CSA-properties of TA, EDL and SOL, which could, partly, explain the absence of peak...

  1. Protein-containing nutrient supplementation following strength training enhances the effect on muscle mass, strength, and bone formation in postmenopausal women

    Holm, Lars; Olesen, Jens L; Matsumoto, Keitaro

    2008-01-01

    .0 +/- 1.4%); nutrient group: 0.953 +/- 0.051 to 0.978 +/- 0.043 g/mm(3) (3.8 +/- 3.4%)] when adjusted for age, body mass index, and BMD at inclusion. Bone formation displayed an interaction (P increased osteocalcin at 24 wk in the nutrient group. In conclusion, we report...... that nutrient supplementation results in superior improvements in muscle mass, muscle strength, femoral neck BMD, and bone formation during 24 wk of strength training. The observed differences following such a short intervention emphasize the significance of postexercise nutrient supply on musculoskeletal......We evaluated the response of various muscle and bone adaptation parameters with 24 wk of strength training in healthy, early postmenopausal women when a nutrient supplement (protein, carbohydrate, calcium, and vitamin D) or a placebo supplement (a minimum of energy) was ingested immediately...

  2. Protein-containing nutrient supplementation following strength training enhances the effect on muscle mass, strength, and bone formation in postmenopausal women

    Holm, Lars; Olesen, J.L.; Matsumoto, K.

    2008-01-01

    .4%); nutrient group: 0.953 ± 0.051 to 0.978 ± 0.043 g/mm3 (3.8 ± 3.4%)] when adjusted for age, body mass index, and BMD at inclusion. Bone formation displayed an interaction (P increased osteocalcin at 24 wk in the nutrient group. In conclusion, we report that nutrient supplementation...... results in superior improvements in muscle mass, muscle strength, femoral neck BMD, and bone formation during 24 wk of strength training. The observed differences following such a short intervention emphasize the significance of postexercise nutrient supply on musculoskeletal maintenance.......We evaluated the response of various muscle and bone adaptation parameters with 24 wk of strength training in healthy, early postmenopausal women when a nutrient supplement (protein, carbohydrate, calcium, and vitamin D) or a placebo supplement (a minimum of energy) was ingested immediately...

  3. FORMALDEHYDE MASERS: EXCLUSIVE TRACERS OF HIGH-MASS STAR FORMATION

    Araya, E. D.; Brown, J. E. [Western Illinois University, Physics Department, 1 University Circle, Macomb, IL 61455 (United States); Olmi, L. [INAF, Osservatorio Astrofisico di Arcetri, Largo E. Fermi 5, I-50125 Firenze (Italy); Ortiz, J. Morales [University of Puerto Rico, Río Piedras Campus, Physical Sciences Department, P.O. Box 23323, San Juan, PR 00931 (United States); Hofner, P.; Creech-Eakman, M. J. [New Mexico Institute of Mining and Technology, Physics Department, 801 Leroy Place, Socorro, NM 87801 (United States); Kurtz, S. [Instituto de Radioastronomía y Astrofísica, Universidad Nacional Autónoma de México, Apdo. Postal 3-72, 58089 Morelia, Michoacán (Mexico); Linz, H. [Max-Planck-Institut für Astronomie, Königstuhl 17, D-69117 Heidelberg (Germany)

    2015-11-15

    The detection of four formaldehyde (H{sub 2}CO) maser regions toward young high-mass stellar objects in the last decade, in addition to the three previously known regions, calls for an investigation of whether H{sub 2}CO masers are an exclusive tracer of young high-mass stellar objects. We report the first survey specifically focused on the search for 6 cm H{sub 2}CO masers toward non high-mass star-forming regions (non HMSFRs). The observations were conducted with the 305 m Arecibo Telescope toward 25 low-mass star-forming regions, 15 planetary nebulae and post-AGB stars, and 31 late-type stars. We detected no H{sub 2}CO emission in our sample of non HMSFRs. To check for the association between high-mass star formation and H{sub 2}CO masers, we also conducted a survey toward 22 high-mass star-forming regions from a Hi-GAL (Herschel infrared Galactic Plane Survey) sample known to harbor 6.7 GHz CH{sub 3}OH masers. We detected a new 6 cm H{sub 2}CO emission line in G32.74−0.07. This work provides further evidence that supports an exclusive association between H{sub 2}CO masers and young regions of high-mass star formation. Furthermore, we detected H{sub 2}CO absorption toward all Hi-GAL sources, and toward 24 low-mass star-forming regions. We also conducted a simultaneous survey for OH (4660, 4750, 4765 MHz), H110α (4874 MHz), HCOOH (4916 MHz), CH{sub 3}OH (5005 MHz), and CH{sub 2}NH (5289 MHz) toward 68 of the sources in our sample of non HMSFRs. With the exception of the detection of a 4765 MHz OH line toward a pre-planetary nebula (IRAS 04395+3601), we detected no other spectral line to an upper limit of 15 mJy for most sources.

  4. High-resolution respirometry of fine-needle muscle biopsies in pre-manifest Huntington's disease expansion mutation carriers shows normal mitochondrial respiratory function.

    Eva Buck

    Full Text Available Alterations in mitochondrial respiration are an important hallmark of Huntington's disease (HD, one of the most common monogenetic causes of neurodegeneration. The ubiquitous expression of the disease causing mutant huntingtin gene raises the prospect that mitochondrial respiratory deficits can be detected in skeletal muscle. While this tissue is readily accessible in humans, transgenic animal models offer the opportunity to cross-validate findings and allow for comparisons across organs, including the brain. The integrated respiratory chain function of the human vastus lateralis muscle was measured by high-resolution respirometry (HRR in freshly taken fine-needle biopsies from seven pre-manifest HD expansion mutation carriers and nine controls. The respiratory parameters were unaffected. For comparison skeletal muscle isolated from HD knock-in mice (HdhQ111 as well as a broader spectrum of tissues including cortex, liver and heart muscle were examined by HRR. Significant changes of mitochondrial respiration in the HdhQ knock-in mouse model were restricted to the liver and the cortex. Mitochondrial mass as quantified by mitochondrial DNA copy number and citrate synthase activity was stable in murine HD-model tissue compared to control. mRNA levels of key enzymes were determined to characterize mitochondrial metabolic pathways in HdhQ mice. We demonstrated the feasibility to perform high-resolution respirometry measurements from small human HD muscle biopsies. Furthermore, we conclude that alterations in respiratory parameters of pre-manifest human muscle biopsies are rather limited and mirrored by a similar absence of marked alterations in HdhQ skeletal muscle. In contrast, the HdhQ111 murine cortex and liver did show respiratory alterations highlighting the tissue specific nature of mutant huntingtin effects on respiration.

  5. Mass spectrometry applied to high temperature chemistry, (2)

    Asano, Mitsuru; Kato, Eiichi; Sata, Toshiyuki.

    1980-01-01

    The application of mass spectrometry to high temperature chemistry is reviewed. As a blanket material for fusion reactors, the behavior of lithium has been investigated by using mass analysers. The enthalpies of the chemical reactions of metallic lithium were obtained. The enthalpies of isomolecular exchange reactions and the derived atomization energies of LiD, Li 2 D and Li 2 D 2 were also obtained by mass spectrometry. The thermomechanical character of lithium oxide was studied. The vaporization behaviors of LiCrO 2 and Li 5 FeO 4 were studied with a quadrupole mass analyser. The vaporization of cobalt from nickel alloy was studied. The evaporated ions were analysed with a mass analyser. The measurement of the vaporized molecules of metals and fused silicate was made by mass spectrometry. The activities of Fe-V system were determined by measuring the ion current ratio. The activities of Fe-V-Cr system were also obtained. The vapor pressure of phosphor from Fe-P alloys can be measured. The activity coefficients and interaction parameters for the dilute solutions of elements, such as Mn, Al, Cu, Cr, Co, Ni, Si, Ti, V, B, Zr, Mo, C, S, and P, dissolved in liquid iron are shown in a table. The activities of NaCl-KCl system were derived by measuring the ion current ratio and by monomer-dimer method. (Kato, T.)

  6. High-Precision Direct Mass Determination of Unstable Isotopes

    2002-01-01

    The extension of systematic high-precision measurements of the nuclear mass to nuclei far from the valley of $\\beta$ stability is of great interest in nuclear physics and astrophysics. The mass, or binding energy, is a fundamental gross property and a key input parameter for nuclear matter calculations. It is also a sensitive probe for collective and single-particle effects in nuclear structure. \\\\ \\\\ For such purposes, nuclear masses need to be known to an accuracy of about 10$^{-7}$ (i.e. $\\Delta$M~$\\leq$~10~keV for A~=~100). To resolve a particular mass from its nuclear isomers and isobars, resolving power of 10$^6$ are often required. To achieve this, the ions delivered by the on-line mass separator ISOLDE are confined in a Penning quadrupole trap. This trap is placed in the very homogeneous and stable magnetic field of a superconducting magnet. Here, the cyclotron frequency and hence the mass are determined. \\\\ \\\\ The first measurements using this new technique have been completed for a long chain of Cs ...

  7. Quality properties of pre- and post-rigor beef muscle after interventions with high frequency ultrasound.

    Sikes, Anita L; Mawson, Raymond; Stark, Janet; Warner, Robyn

    2014-11-01

    The delivery of a consistent quality product to the consumer is vitally important for the food industry. The aim of this study was to investigate the potential for using high frequency ultrasound applied to pre- and post-rigor beef muscle on the metabolism and subsequent quality. High frequency ultrasound (600kHz at 48kPa and 65kPa acoustic pressure) applied to post-rigor beef striploin steaks resulted in no significant effect on the texture (peak force value) of cooked steaks as measured by a Tenderometer. There was no added benefit of ultrasound treatment above that of the normal ageing process after ageing of the steaks for 7days at 4°C. Ultrasound treatment of post-rigor beef steaks resulted in a darkening of fresh steaks but after ageing for 7days at 4°C, the ultrasound-treated steaks were similar in colour to that of the aged, untreated steaks. High frequency ultrasound (2MHz at 48kPa acoustic pressure) applied to pre-rigor beef neck muscle had no effect on the pH, but the calculated exhaustion factor suggested that there was some effect on metabolism and actin-myosin interaction. However, the resultant texture of cooked, ultrasound-treated muscle was lower in tenderness compared to the control sample. After ageing for 3weeks at 0°C, the ultrasound-treated samples had the same peak force value as the control. High frequency ultrasound had no significant effect on the colour parameters of pre-rigor beef neck muscle. This proof-of-concept study showed no effect of ultrasound on quality but did indicate that the application of high frequency ultrasound to pre-rigor beef muscle shows potential for modifying ATP turnover and further investigation is warranted. Crown Copyright © 2014. Published by Elsevier B.V. All rights reserved.

  8. SIEMENS ADVANCED QUANTRA FTICR MASS SPECTROMETER FOR ULTRA HIGH RESOLUTION AT LOW MASS

    Spencer, W; Laura Tovo, L

    2008-07-08

    The Siemens Advanced Quantra Fourier Transform Ion Cyclotron Resonance (FTICR) mass spectrometer was evaluated as an alternative instrument to large double focusing mass spectrometers for gas analysis. High resolution mass spectrometers capable of resolving the common mass isomers of the hydrogen isotopes are used to provide data for accurate loading of reservoirs and to monitor separation of tritium, deuterium, and helium. Conventional double focusing magnetic sector instruments have a resolution that is limited to about 5000. The Siemens FTICR instrument achieves resolution beyond 400,000 and could possibly resolve the tritium ion from the helium-3 ion, which differ by the weight of an electron, 0.00549 amu. Working with Y-12 and LANL, SRNL requested Siemens to modify their commercial Quantra system for low mass analysis. To achieve the required performance, Siemens had to increase the available waveform operating frequency from 5 MHz to 40 MHz and completely redesign the control electronics and software. However, they were able to use the previous ion trap, magnet, passive pump, and piezo-electric pulsed inlet valve design. NNSA invested $1M in this project and acquired four systems, two for Y-12 and one each for SRNL and LANL. Siemens claimed a $10M investment in the Quantra systems. The new Siemens Advanced Quantra demonstrated phenomenal resolution in the low mass range. Resolution greater than 400,000 was achieved for mass 2. The new spectrometer had a useful working mass range to 500 Daltons. However, experiments found that a continuous single scan from low mass to high was not possible. Two useful working ranges were established covering masses 1 to 6 and masses 12 to 500 for our studies. A compromise performance condition enabled masses 1 to 45 to be surveyed. The instrument was found to have a dynamic range of about three orders of magnitude and quantitative analysis is expected to be limited to around 5 percent without using complex fitting algorithms

  9. Swimming exercise increases serum irisin level and reduces body fat mass in high-fat-diet fed Wistar rats.

    Lu, Yun; Li, Hongwei; Shen, Shi-Wei; Shen, Zhen-Hai; Xu, Ming; Yang, Cheng-Jian; Li, Feng; Feng, Yin-Bo; Yun, Jing-Ting; Wang, Ling; Qi, Hua-Jin

    2016-05-13

    It has been shown that irisin levels are reduced in skeletal muscle and plasma of obese rats; however, the effect of exercise training on irisin level remains controversial. We aim to evaluate the association of swimming exercise with serum irisin level and other obesity-associated parameters. Forty healthy male Wistar rats were randomly assigned to 4 groups: a normal diet and sedentary group (ND group), normal diet and exercise group (NDE group), high-fat diet and sedentary group (HFD group), and high-fat diet and exercise group (HFDE group. After 8 consecutive weeks of swimming exercise, fat mass and serum irisin level was determined. Higher serum irisin levels were detected in the HFDE group (1.15 ± 0.28 μg/L) and NDE group (1.76 ± 0.17 μg/L) than in the HFD group (0.84 ± 0.23 μg/L) or the ND group (1.24 ± 0.29 μg/L), respectively (HFDE group vs. HFD group, P mass (r = -0.68, P mass (r = -0.576, P mass (r = -0.439, P mass, visceral fat mass and percentage fat mass were lower in the HFDE group than the HFD group (all P values mass in high-fat-fed Wistar rats, which may be attributable to elevated irisin levels induced by swimming exercise.

  10. Low skeletal muscle mass is a predictive factor for chemotherapy dose-limiting toxicity in patients with locally advanced head and neck cancer

    Wendrich, Anne W; Swartz, Justin E; Bril, Sandra I; Wegner, Inge; de Graeff, Alexander; Smid, Ernst J; de Bree, Remco; Pothen, Ajit J

    OBJECTIVES: Low skeletal muscle mass (SMM) or sarcopenia is emerging as an adverse prognostic factor for chemotherapy dose-limiting toxicity (CLDT) and survival in cancer patients. Our aim was to determine the impact of low SMM on CDLT in patients with locally advanced head and neck squamous cell

  11. Efficacy of whey protein supplementation on resistance exercise-induced changes in muscle strength, lean mass, and function in mobility-limited older adults

    Whey protein supplementation may augment resistance exercise-induced increases in muscle strength and mass. Further studies are required to determine whether this effect extends to functionally compromised older adults. The objectives of the study were to compare the effects of whey protein concent...

  12. The Impact of dietary protein or amino acid supplementation on muscle mass and strength in elderly people : individual participant data and meta-analysis of RCT's

    Tieland, M.; Franssen, R.; Dullemeijer, C.; van Dronkelaar, C; Kyung Kim, H.; Ispoglou, T; Zhu, K.; Prince, R. L.; van Loon, L. J. C.; de Groot, Lisette C. P. G. M.

    2017-01-01

    OBJECTIVES: Increasing protein or amino acid intake has been promoted as a promising strategy to increase muscle mass and strength in elderly people, however, long-term intervention studies show inconsistent findings. Therefore, we aim to determine the impact of protein or amino acid supplementation

  13. Yeast expression proteomics by high-resolution mass spectrometry

    Walther, Tobias C; Olsen, Jesper Velgaard; Mann, Matthias

    2010-01-01

    -translational controls contribute majorly to regulation of protein abundance, for example in heat shock stress response. The development of new sample preparation methods, high-resolution mass spectrometry and novel bioinfomatic tools close this gap and allow the global quantitation of the yeast proteome under different...

  14. High-Performance Liquid Chromatography-Mass Spectrometry.

    Vestal, Marvin L.

    1984-01-01

    Reviews techniques for online coupling of high-performance liquid chromatography with mass spectrometry, emphasizing those suitable for application to nonvolatile samples. Also summarizes the present status, strengths, and weaknesses of various techniques and discusses potential applications of recently developed techniques for combined liquid…

  15. High-mass stars in Milky Way clusters

    Negueruela, Ignacio

    2017-11-01

    Young open clusters are our laboratories for studying high-mass star formation and evolution. Unfortunately, the information that they provide is difficult to interpret, and sometimes contradictory. In this contribution, I present a few examples of the uncertainties that we face when confronting observations with theoretical models and our own assumptions.

  16. Aluminum nano-cantilevers for high sensitivity mass sensors

    Davis, Zachary James; Boisen, Anja

    2005-01-01

    We have fabricated Al nano-cantilevers using a very simple one mask contact UV lithography technique with lateral dimensions under 500 nm and vertical dimensions of approximately 100 nm. These devices are demonstrated as highly sensitive mass sensors by measuring their dynamic properties. Further...

  17. High Resolution Mass Spectrometry of Polyfluorinated Polyether-Based Formulation

    Dimzon, Ian Ken; Trier, Xenia; Frömel, Tobias; Helmus, Rick; Knepper, Thomas P.; de Voogt, Pim

    2016-02-01

    High resolution mass spectrometry (HRMS) was successfully applied to elucidate the structure of a polyfluorinated polyether (PFPE)-based formulation. The mass spectrum generated from direct injection into the MS was examined by identifying the different repeating units manually and with the aid of an instrument data processor. Highly accurate mass spectral data enabled the calculation of higher-order mass defects. The different plots of MW and the nth-order mass defects (up to n = 3) could aid in assessing the structure of the different repeating units and estimating their absolute and relative number per molecule. The three major repeating units were -C2H4O-, -C2F4O-, and -CF2O-. Tandem MS was used to identify the end groups that appeared to be phosphates, as well as the possible distribution of the repeating units. Reversed-phase HPLC separated of the polymer molecules on the basis of number of nonpolar repeating units. The elucidated structure resembles the structure in the published manufacturer technical data. This analytical approach to the characterization of a PFPE-based formulation can serve as a guide in analyzing not just other PFPE-based formulations but also other fluorinated and non-fluorinated polymers. The information from MS is essential in studying the physico-chemical properties of PFPEs and can help in assessing the risks they pose to the environment and to human health.

  18. High- and low-molecular-mass microbial surfactants.

    Rosenberg, E; Ron, E Z

    1999-08-01

    Microorganisms synthesize a wide variety of high- and low-molecular-mass bioemulsifiers. The low-molecular-mass bioemulsifiers are generally glycolipids, such as trehalose lipids, sophorolipids and rhamnolipids, or lipopeptides, such as surfactin, gramicidin S and polymyxin. The high-molecular-mass bioemulsifiers are amphipathic polysaccharides, proteins, lipopolysaccharides, lipoproteins or complex mixtures of these biopolymers. The low-molecular-mass bioemulsifiers lower surface and interfacial tensions, whereas the higher-molecular-mass bioemulsifiers are more effective at stabilizing oil-in-water emulsions. Three natural roles for bioemulsifiers have been proposed: (i) increasing the surface area of hydrophobic water-insoluble growth substrates; (ii) increasing the bioavailability of hydrophobic substrates by increasing their apparent solubility or desorbing them from surfaces; (iii) regulating the attachment and detachment of microorganisms to and from surfaces. Bioemulsifiers have several important advantages over chemical surfactants, which should allow them to become prominent in industrial and environmental applications. The potential commercial applications of bioemulsifiers include bioremediation of oil-polluted soil and water, enhanced oil recovery, replacement of chlorinated solvents used in cleaning-up oil-contaminated pipes, vessels and machinery, use in the detergent industry, formulations of herbicides and pesticides and formation of stable oil-in-water emulsions for the food and cosmetic industries.

  19. Young men with low birthweight exhibit decreased plasticity of genome-wide muscle DNA methylation by high-fat overfeeding

    Jacobsen, Stine C; Gillberg, Linn; Bork-Jensen, Jette

    2014-01-01

    The association between low birthweight (LBW) and risk of developing type 2 diabetes may involve epigenetic mechanisms, with skeletal muscle being a prime target tissue. Differential DNA methylation patterns have been observed in single genes in muscle tissue from type 2 diabetic and LBW...... individuals, and we recently showed multiple DNA methylation changes during short-term high-fat overfeeding in muscle of healthy people. In a randomised crossover study, we analysed genome-wide DNA promoter methylation in skeletal muscle of 17 young LBW men and 23 matched normal birthweight (NBW) men after...... a control and a 5 day high-fat overfeeding diet....

  20. Application of tuned mass dampers in high-rise construction

    Teplyshev, Vyacheslav; Mylnik, Alexey; Pushkareva, Maria; Agakhanov, Murad; Burova, Olga

    2018-03-01

    The article considers the use of tuned mass dampers in high-rise construction for significant acceleration and amplitude of vibrations of the upper floors under dynamic wind influences. The susceptibility of people to accelerations in high-rise buildings and possible means of reducing wind-induced fluctuations in buildings are analyzed. The statistics of application of tuned mass dampers in high-rise construction all over the world is presented. The goal of the study is to identify an economically attractive solution that allows the fullest use of the potential of building structures in high-rise construction, abandoning the need to build massive frames leading to over-consumption of materials.

  1. Automated data processing of high-resolution mass spectra

    Hansen, Michael Adsetts Edberg; Smedsgaard, Jørn

    of the massive amounts of data. We present an automated data processing method to quantitatively compare large numbers of spectra from the analysis of complex mixtures, exploiting the full quality of high-resolution mass spectra. By projecting all detected ions - within defined intervals on both the time...... infusion of crude extracts into the source taking advantage of the high sensitivity, high mass resolution and accuracy and the limited fragmentation. Unfortunately, there has not been a comparable development in the data processing techniques to fully exploit gain in high resolution and accuracy...... infusion analyses of crude extract to find the relationship between species from several species terverticillate Penicillium, and also that the ions responsible for the segregation can be identified. Furthermore the process can automate the process of detecting unique species and unique metabolites....

  2. Compensating effect of minor portal hypertension on the muscle mass loss-related poor prognosis in cirrhosis.

    Maruyama, Hitoshi; Kobayashi, Kazufumi; Kiyono, Soichiro; Ogasawara, Sadahisa; Suzuki, Eichiro; Ooka, Yoshihiko; Chiba, Tetsuhiro; Yamaguchi, Tadashi

    2017-01-01

    Background: To examine the influence of the severity of portal hemodynamic abnormality on the prognosis of cirrhosis with respect to the muscle mass loss (MML). Methods: The study involved a subgroup analysis in 98 cirrhosis patients (63.5 ± 11.8 years) who prospectively underwent both Doppler ultrasound and hepatic venous catheterization. The prognostic influence of MML diagnosed by computed tomography using the L3 skeletal muscle index was evaluated (median observation period, 32.7 months). Results: The cumulative survival rate showed difference between patients with MML (n = 34; 82.2%/1year, 41.2%/3years and 36.1%/5years) and those without (n = 64; 92.1%/1year, 74.9%/3years and 69.4%/5years; P = 0.005). When divided with respect to the portal velocity, the survival rate showed differences between patients with and without MML in the cohort 12 mmHg. However, in the cohort with HVPG ≤ 12 mmHg, survival rate showed no difference between patients with MML (n=10; 100%/1year, 61.9%/3years and 61.9%/5years) and those without (n=19; 93.8%/1year, 71.2%/3years and 59.4%/5years; p = 0.493) Conclusion: Lower HVPG has a compensating effect on the MML-induced poor prognosis of cirrhosis. Care should be taken in the evaluation of the influence of MML in consideration of the severity of portal hypertension.

  3. Ultrastructural pathological study on skeletal muscle injury in rabbit after a high-dose radiation

    Sun Wei; Ni Xinchu; Sun Suping; Cai Leiming; Yu Jingping; Wang Jian; Nie Bin; Sun Zhiqiang; Ni Xinye; Cao Xiufeng

    2012-01-01

    Objective: To establish a rabbit model of radiation-induced skeletal muscle injury in order to study the ultrastructural pathological changes and underlying mechanism. Methods: 28 New Zealand rabbits were randomly divided into 2 groups with 16 rabbits in experimental group and 12 rabbits in control group. The experimental rabbits were irradiated on hip with a single dose of 80 Gy of 9 MeV electrons from a linear accelerator. 1 month and 6 months after irradiation the pathological changes were respectively observed under light microscope and electron microscope. Results: One month after irradiation, the morphologic changes including degeneration, necrosis of muscle cells, and hemorrhage between the muscle cells were observed under light microscope and the swelling of myofibrillae, blurring of light and shade band, vacuolar degeneration of mitochondria and amorphous areas of necrosis were observed under electron microscope. Six months after irradiation, the morphologic changes of nucleolus chips, fibrous connective tissue, thickening of vascular wall and vascular congestion between the muscle cells and the amorphous areas of necrosis in the experimental group were much more serious than those of 1 month after irradiation. In addition, the myofilaments were lost in degeneration areas and the sarcomere became shorten. Observation with electron microscope showed that the mitochondrial size and its morphological changes were varied and the amounts of collagen between myofibrillaes were increased 6 months after irradiation. Conclusions: A rabbit model of high-dose irradiated skeleton muscle injury was successfully established with a single dose of 80 Gy of 9 MeV electrons from a linear accelerator. The degeneration and necrosis of muscle cells may be promoted by mitochondrial and vascular injury, degeneration of vessel and nerve fiber. (authors)

  4. An ATLAS event with a high mass dijet system

    ATLAS, Experiment

    2014-01-01

    Event with a high mass dijet system: the invariant mass of the two highest-pT jets is 2.55 TeV. The highest pT jet has a pT of 420 GeV, and an eta of -1.51, the second leading jet has pT of 320 GeV and an eta of 2.32. Jet momenta are calibrated according to the "EM+JES" scheme. No other jets are found with pT above 20 GeV. Event collected on 4 July 2010.

  5. Normalised Mutual Information of High-Density Surface Electromyography during Muscle Fatigue

    Adrian Bingham

    2017-12-01

    Full Text Available This study has developed a technique for identifying the presence of muscle fatigue based on the spatial changes of the normalised mutual information (NMI between multiple high density surface electromyography (HD-sEMG channels. Muscle fatigue in the tibialis anterior (TA during isometric contractions at 40% and 80% maximum voluntary contraction levels was investigated in ten healthy participants (Age range: 21 to 35 years; Mean age = 26 years; Male = 4, Female = 6. HD-sEMG was used to record 64 channels of sEMG using a 16 by 4 electrode array placed over the TA. The NMI of each electrode with every other electrode was calculated to form an NMI distribution for each electrode. The total NMI for each electrode (the summation of the electrode’s NMI distribution highlighted regions of high dependence in the electrode array and was observed to increase as the muscle fatigued. To summarise this increase, a function, M(k, was defined and was found to be significantly affected by fatigue and not by contraction force. The technique discussed in this study has overcome issues regarding electrode placement and was used to investigate how the dependences between sEMG signals within the same muscle change spatially during fatigue.

  6. Decreased rate of protein synthesis, caspase-3 activity, and ubiquitin-proteasome proteolysis in soleus muscles from growing rats fed a low-protein, high-carbohydrate diet.

    Batistela, Emanuele; Pereira, Mayara Peron; Siqueira, Juliany Torres; Paula-Gomes, Silvia; Zanon, Neusa Maria; Oliveira, Eduardo Brandt; Navegantes, Luiz Carlos Carvalho; Kettelhut, Isis C; Andrade, Claudia Marlise Balbinotti; Kawashita, Nair Honda; Baviera, Amanda Martins

    2014-06-01

    The aim of this study was to investigate the changes in the rates of both protein synthesis and breakdown, and the activation of intracellular effectors that control these processes in soleus muscles from growing rats fed a low-protein, high-carbohydrate (LPHC) diet for 15 days. The mass and the protein content, as well as the rate of protein synthesis, were decreased in the soleus from LPHC-fed rats. The availability of amino acids was diminished, since the levels of various essential amino acids were decreased in the plasma of LPHC-fed rats. Overall rate of proteolysis was also decreased, explained by reductions in the mRNA levels of atrogin-1 and MuRF-1, ubiquitin conjugates, proteasome activity, and in the activity of caspase-3. Soleus muscles from LPHC-fed rats showed increased insulin sensitivity, with increased levels of insulin receptor and phosphorylation levels of AKT, which probably explains the inhibition of both the caspase-3 activity and the ubiquitin-proteasome system. The fall of muscle proteolysis seems to represent an adaptive response that contributes to spare proteins in a condition of diminished availability of dietary amino acids. Furthermore, the decreased rate of protein synthesis may be the driving factor to the lower muscle mass gain in growing rats fed the LPHC diet.

  7. Associations between lower extremity muscle mass and multiplanar knee laxity and stiffness: a potential explanation for sex differences in frontal and transverse plane knee laxity.

    Shultz, Sandra J; Pye, Michele L; Montgomery, Melissa M; Schmitz, Randy J

    2012-12-01

    Compared with men, women have disproportionally greater frontal (varus-valgus) and transverse (internal-external) plane laxity and lower stiffness, despite having similar sagittal (anterior-posterior) plane laxity and stiffness. While the underlying cause is unclear, the amount of lower extremity lean mass (LELM) may be a contributing factor. Lower extremity lean mass would be a stronger predictor of frontal and transverse plane laxity and incremental stiffness than the sagittal plane. Associations between LELM and stiffness would be stronger at lower force increments. Descriptive laboratory study. Sixty-three women and 30 men with no history of ligament injury were measured for knee laxity and incremental stiffness in the sagittal (-90- to 130-N posterior-to-anterior directed loads), frontal (±10-N·m varus-valgus torques), and transverse (±5-N·m internal-external rotation torques) planes and underwent dual-energy X-ray absorptiometry scans to measure LELM. Linear regressions examined the extent to which LELM predicted each laxity and stiffness value, while also accounting for a person's sex. Females (vs males) had greater laxity and less stiffness in the frontal and transverse planes but not the sagittal plane. Lower extremity lean mass was a poor predictor of sagittal laxity and stiffness (R (2) range = .021-.081; P > .06) but was a stronger predictor of frontal (R (2) range = .215-.567; P plane laxity and stiffness. Associations were stronger for low (R (2) = .495-.504) versus high (R (2) = .215-.435) frontal plane stiffness but were similar for low (R (2) = .233-.293) versus high (R (2) = .224-.356) transverse plane stiffness. Once we accounted for a person's LELM, sex had little effect on laxity and stiffness (change in R (2) after removal = .01-.08; P = .027-.797). Less LELM was associated with greater laxity and less stiffness in frontal and transverse planes, which may contribute to the disproportionally higher laxities and reduced stiffnesses observed

  8. The high mass frontier: limits on heavy neutrinos

    Gronau, M.

    1984-01-01

    The theoretical motivation for a search for heavy neutrinos is discussed followed by the presentation of typical model dependent expectations for the mixing of the latter with ordinary neutrinos. Present mass and mixing limits on such heavy neutral leptons are based on search for secondary peaks in π and K leptonic decays and on the absence of neutrino decay signatures in neutrino beams from conventional sources and beam dumps. While these limits are quite poor for masses above 1 GeV, we describe methods to extend the limits to masses in the many GeV region. Such limits may be derived from search in b decays, high statistics neutrino experiments, search in ep colliders, W and Z decays and finally - decays of very heavy gauge bosons (if such exist in the TeV region) when produced in multi-TeV pp and antipp colliders

  9. High mass-asymmetry distributions of fissioning nuclei

    Sandulescu, A.; Lusting, H.J.; Hahn, J.; Greiner, W.

    1978-07-01

    It is shown that new mass-asymmetry valleys are appearing in the fragmentation potential V(l,eta) as function of the length l and mass-asymmetry coordinate eta = (A 1 - A 2 )to a correct treatment of the shell effects such that for separated fragments the shell effects equal the sum of the shell effects of the individual fragments and correspond to the double magic fragments 48 Ca, 78 Ni, 132 Sn and 208 Pb or may be 56 Ni. Also is shown that the fission mass-distributions have additional peaks corresponding to the bottom of these new valleys. The calculations are illustrated for 252 No and 238 U. The preliminary results show for 238 U relatively high percent yields in agreement with present available experimental data. (author)

  10. Shear wave elastography for breast masses is highly reproducible.

    Cosgrove, David O; Berg, Wendie A; Doré, Caroline J; Skyba, Danny M; Henry, Jean-Pierre; Gay, Joel; Cohen-Bacrie, Claude

    2012-05-01

    To evaluate intra- and interobserver reproducibility of shear wave elastography (SWE) for breast masses. For intraobserver reproducibility, each observer obtained three consecutive SWE images of 758 masses that were visible on ultrasound. 144 (19%) were malignant. Weighted kappa was used to assess the agreement of qualitative elastographic features; the reliability of quantitative measurements was assessed by intraclass correlation coefficients (ICC). For the interobserver reproducibility, a blinded observer reviewed images and agreement on features was determined. Mean age was 50 years; mean mass size was 13 mm. Qualitatively, SWE images were at least reasonably similar for 666/758 (87.9%). Intraclass correlation for SWE diameter, area and perimeter was almost perfect (ICC ≥ 0.94). Intraobserver reliability for maximum and mean elasticity was almost perfect (ICC = 0.84 and 0.87) and was substantial for the ratio of mass-to-fat elasticity (ICC = 0.77). Interobserver agreement was moderate for SWE homogeneity (κ = 0.57), substantial for qualitative colour assessment of maximum elasticity (κ = 0.66), fair for SWE shape (κ = 0.40), fair for B-mode mass margins (κ = 0.38), and moderate for B-mode mass shape (κ = 0.58), orientation (κ = 0.53) and BI-RADS assessment (κ = 0.59). SWE is highly reproducible for assessing elastographic features of breast masses within and across observers. SWE interpretation is at least as consistent as that of BI-RADS ultrasound B-mode features. • Shear wave ultrasound elastography can measure the stiffness of breast tissue • It provides a qualitatively and quantitatively interpretable colour-coded map of tissue stiffness • Intraobserver reproducibility of SWE is almost perfect while intraobserver reproducibility of SWE proved to be moderate to substantial • The most reproducible SWE features between observers were SWE image homogeneity and maximum elasticity.

  11. Masseter muscle surface electromyography in college students with a high degree of anxiety and temporomandibular disorder

    Eduarda de Lima Amarante

    Full Text Available ABSTRACT Objective: to compare the electrical activity of masseter muscles, bilaterally, according to the presence or absence of Temporomandibular Disorder (TMD in college students with a high degree of anxiety. Methods: the study was conducted with a randomized sample of 31 Speech Therapy students aged between 17 and 32 years; 61.3% (n = 19 were females and 38.7% (n = 12 were males. They were divided into two groups, Group 1 (G1, comprising 11 students with TMD, and Group 2 (G2, composed of 20 students without TMD. The college students answered the State-Trait Anxiety Inventory (STAI for anxiety investigation, and were evaluated by the protocol Research Diagnostic Criteria for Temporomandibular Disorders (RDC/TMD for TMD diagnosis. The evaluation of muscular electrical activity took into account the records in the conditions of rest, Sustained Maximum Voluntary Activity (SMVA and habitual chewing (HC. The data were analyzed using the version 22 IBM Statistical Package for Social Sciences (SPSS software. The statistical analysis was performed using Student t test to compare means between groups, considering < 0,05 as the significant p-value. Results: college students, of both groups, presented high levels of anxiety traits. Significant statistical differences were observed on the percentage of electrical activity of right masseter muscle in chewing function, as well as muscle fibers recruitment during chewing, which were higher on the group without TMD. Conclusion: college students with TMD and a high degree of anxiety presented lower means of masseter muscle electromyografic activity during chewing, in most conditions assessed, as compared to volunteers without TMD, except for the left masseter muscle in rest and chewing.

  12. Ultrananocrystalline Diamond Membranes for Detection of High-Mass Proteins

    Kim, H.; Park, J.; Aksamija, Z.; Arbulu, M.; Blick, R. H.

    2016-12-01

    Mechanical resonators realized on the nanoscale by now offer applications in mass sensing of biomolecules with extraordinary sensitivity. The general idea is that perfect mechanical mass sensors should be of extremely small size to achieve zepto- or yoctogram sensitivity in weighing single molecules similar to a classical scale. However, the small effective size and long response time for weighing biomolecules with a cantilever restricts their usefulness as a high-throughput method. Commercial mass spectrometry (MS), on the other hand, such as electrospray ionization and matrix-assisted laser desorption and ionization (MALDI) time of flight (TOF) and their charge-amplifying detectors are the gold standards to which nanomechanical resonators have to live up to. These two methods rely on the ionization and acceleration of biomolecules and the following ion detection after a mass selection step, such as TOF. The principle we describe here for ion detection is based on the conversion of kinetic energy of the biomolecules into thermal excitation of chemical vapor deposition diamond nanomembranes via phonons followed by phonon-mediated detection via field emission of thermally emitted electrons. We fabricate ultrathin diamond membranes with large lateral dimensions for MALDI TOF MS of high-mass proteins. These diamond membranes are realized by straightforward etching methods based on semiconductor processing. With a minimal thickness of 100 nm and cross sections of up to 400 ×400 μ m2 , the membranes offer extreme aspect ratios. Ion detection is demonstrated in MALDI TOF analysis over a broad range from insulin to albumin. The resulting data in detection show much enhanced resolution as compared to existing detectors, which can offer better sensitivity and overall performance in resolving protein masses.

  13. Differential metabolic effects of constant moderate versus high intensity interval training in high-fat fed mice: possible role of muscle adiponectin.

    Martinez-Huenchullan, Sergio F; Maharjan, Babu Raja; Williams, Paul F; Tam, Charmaine S; Mclennan, Susan V; Twigg, Stephen M

    2018-02-01

    Exercise regimens may have differing effects in the presence of obesity. In addition to being fat derived, adiponectin has recently been described as a myokine that regulates insulin sensitivity, which may link to exercise-related metabolic benefits in obesity. Whether skeletal muscle adiponectin varies in different exercise modalities is unclear. This study investigated the comparative effects of 10 weeks of endurance constant-moderate intensity exercise (END) with high intensity interval training (HIIT), on metabolic outcomes, including muscle adiponectin in a mouse model of diet-induced obesity. Ten-week-old male C57BL/6 mice were fed a high-fat diet (HFD) (45% FAT) or standard CHOW diet ab libitum and underwent one of three training regimes: (1) no exercise, (2) END, or (3) HIIT (8 bouts of 2.5 min with eight periods of rest of 2.5 min) for 10 weeks (3 × 40 min sessions/week). Chow-fed mice acted as controls. Compared with HFD alone, both training programs similarly protected against body weight gain (HFD = 45 ± 2; END = 37 ± 2; HIIT = 36 ± 2 g), preserved lean/fat tissue mass ratio (HFD = 0.64 ± 0.09; END = 0.34 ± 0.13; HIIT = 0.33 ± 0.13), and improved blood glucose excursion during an insulin tolerance test (HFD = 411 ± 54; END = 350 ± 57; HIIT = 320 ± 66 arbitrary units [AU]). Alterations in fasting glycemia, insulinemia, and AST/ALT ratios were prevented only by END. END, but not HIIT increased skeletal muscle adiponectin mRNA (14-fold; P HIIT induced a milder increase (2.4-fold). Compared with HFD, neither END nor HIIT altered circulating low (LMW) or high (HMW) molecular weight adiponectin forms. Furthermore, only END prevented the HFD downregulation of PGC1α (P < 0.05) mRNA levels downstream of muscle adiponectin. These data show that different training programs affect muscle adiponectin to differing degrees. Together these results suggest that END is a more effective regimen to prevent HFD

  14. High-performance mass storage system for workstations

    Chiang, T.; Tang, Y.; Gupta, L.; Cooperman, S.

    1993-01-01

    Reduced Instruction Set Computer (RISC) workstations and Personnel Computers (PC) are very popular tools for office automation, command and control, scientific analysis, database management, and many other applications. However, when using Input/Output (I/O) intensive applications, the RISC workstations and PC's are often overburdened with the tasks of collecting, staging, storing, and distributing data. Also, by using standard high-performance peripherals and storage devices, the I/O function can still be a common bottleneck process. Therefore, the high-performance mass storage system, developed by Loral AeroSys' Independent Research and Development (IR&D) engineers, can offload a RISC workstation of I/O related functions and provide high-performance I/O functions and external interfaces. The high-performance mass storage system has the capabilities to ingest high-speed real-time data, perform signal or image processing, and stage, archive, and distribute the data. This mass storage system uses a hierarchical storage structure, thus reducing the total data storage cost, while maintaining high-I/O performance. The high-performance mass storage system is a network of low-cost parallel processors and storage devices. The nodes in the network have special I/O functions such as: SCSI controller, Ethernet controller, gateway controller, RS232 controller, IEEE488 controller, and digital/analog converter. The nodes are interconnected through high-speed direct memory access links to form a network. The topology of the network is easily reconfigurable to maximize system throughput for various applications. This high-performance mass storage system takes advantage of a 'busless' architecture for maximum expandability. The mass storage system consists of magnetic disks, a WORM optical disk jukebox, and an 8mm helical scan tape to form a hierarchical storage structure. Commonly used files are kept in the magnetic disk for fast retrieval. The optical disks are used as archive

  15. Clinical Outcomes of Living Liver Transplantation According to the Presence of Sarcopenia as Defined by Skeletal Muscle Mass, Hand Grip, and Gait Speed.

    Harimoto, N; Yoshizumi, T; Izumi, T; Motomura, T; Harada, N; Itoh, S; Ikegami, T; Uchiyama, H; Soejima, Y; Nishie, A; Kamishima, T; Kusaba, R; Shirabe, K; Maehara, Y

    2017-11-01

    Sarcopenia is an independent predictor of death after living-donor liver transplantation (LDLT). However, the ability of the Asian Working Group for Sarcopenia criteria for sarcopenia (defined as reduced skeletal muscle mass plus low muscle strength) to predict surgical outcomes in patients who have undergone LDLT has not been determined. This study prospectively enrolled 366 patients who underwent LDLT at Kyushu University Hospital. Skeletal muscle area (determined by computed tomography), hand-grip strength, and gait speed were measured in 102 patients before LDLT. We investigated the relationship between sarcopenia and surgical outcomes after LDLT performed in three time periods. The number of patients with lower skeletal muscle area has increased to 52.9% in recent years. The incidence of sarcopenia according to the Asian Working Group for Sarcopenia criteria was 23.5% (24/102). Patients with sarcopenia (defined by skeletal muscle area and functional parameters) had significantly lower skeletal muscle area and weaker hand-grip strength than did those without sarcopenia. Compared with non-sarcopenic patients, patients with sarcopenia also had significantly worse liver function, greater estimated blood loss, greater incidence of postoperative complications of Clavien-Dindo grade IV or greater (including amount of ascites on postoperative day 14, total bilirubin on postoperative day 14, and postoperative sepsis), and longer postoperative hospital stay. Multiple logistic regression analysis revealed sarcopenia as a significant predictor of 6-month mortality. The combination of skeletal muscle mass and function can predict surgical outcomes in LDLT patients. Copyright © 2017 Elsevier Inc. All rights reserved.

  16. Brachial artery protected by wrapped latissimus dorsi muscle flap in high voltage electrical injury

    Gencel, E.; Eser, C.; Kokacya, O.; Kesiktas, E.; Yavuz, M.

    2016-01-01

    Summary High voltage electrical injury can disrupt the vascular system and lead to extremity amputations. It is important to protect main vessels from progressive burn necrosis in order to salvage a limb. The brachial artery should be totally isolated from the burned area by a muscle flap to prevent vessel disruption. In this study, we report the use of a wrap-around latissimus dorsi muscle flap to protect a skeletonized brachial artery in a high voltage electrical injury in order to salvage the upper extremity and restore function. The flap wrapped around the exposed brachial artery segment and luminal status of the artery was assessed using magnetic resonance angiography. No vascular intervention was required. The flap survived completely with good elbow function. Extremity amputation was not encountered. This method using a latissimus dorsi flap allows the surgeon to protect the main upper extremity artery and reconstruct arm defects, which contributes to restoring arm function in high voltage electrical injury. PMID:28149236

  17. An ultra-sensitive instrument for collision activated dissociation mass spectrometry with high mass resolution

    Louter, G.J.

    1982-01-01

    During the last decade Collision Activated Dissociation Mass Spectrometry (CAD-MS) has developed into an important and sometimes unique technique for the structure elucidation of ions. An extensive description of the double stage MS is given, which has been especially devloped for CAD-MS. A high mass resolution and a very high sensitivity are obtained by application of special techniques like post-acceleration of fragment ions, quadrupole (Q-pole) lenses and an electro-optical, simultaneous ion detection system. The operation of the rather complex ion-optics is demonstrated by application of a computer simulation of the tandem MS. Special attention is given to the action of the four Q-pole lenses and the second sector magnet upon curvature and position of the mass focal plane. Two mass calibration methods are described for the fragment spectra. The so-called polynomial-method applies a fifth-order polynomial approximation of the functional relation between position on the detector and corresponding relative momentum of fragment ions. The second method uses the matrix model of the instrument. The detector consists of two channelplates (CEMA), a fibre optics slab, coated with a phosphor layer, a camera objective and a 1024-channels photodiode-array. A bio-chemical and an organic-chemical application of the instrument are given. As bio-chemical application the peak m/z 59 in the pyrolysis mass spectrum of complete mycobacteria is identified. As an example of organic-chemical application the fragmentation process of 2,3-butadienoic acid has been investigated. (Auth.)

  18. Applications of ambient mass spectrometry in high-throughput screening.

    Li, Li-Ping; Feng, Bao-Sheng; Yang, Jian-Wang; Chang, Cui-Lan; Bai, Yu; Liu, Hu-Wei

    2013-06-07

    The development of rapid screening and identification techniques is of great importance for drug discovery, doping control, forensic identification, food safety and quality control. Ambient mass spectrometry (AMS) allows rapid and direct analysis of various samples in open air with little sample preparation. Recently, its applications in high-throughput screening have been in rapid progress. During the past decade, various ambient ionization techniques have been developed and applied in high-throughput screening. This review discusses typical applications of AMS, including DESI (desorption electrospray ionization), DART (direct analysis in real time), EESI (extractive electrospray ionization), etc., in high-throughput screening (HTS).

  19. High-energy phosphate transfer in human muscle: diffusion of phosphocreatine.

    Gabr, Refaat E; El-Sharkawy, Abdel-Monem M; Schär, Michael; Weiss, Robert G; Bottomley, Paul A

    2011-07-01

    The creatine kinase (CK) reaction is central to muscle energetics, buffering ATP levels during periods of intense activity via consumption of phosphocreatine (PCr). PCr is believed to serve as a spatial shuttle of high-energy phosphate between sites of energy production in the mitochondria and sites of energy utilization in the myofibrils via diffusion. Knowledge of the diffusion coefficient of PCr (D(PCr)) is thus critical for modeling and understanding energy transport in the myocyte, but D(PCr) has not been measured in humans. Using localized phosphorus magnetic resonance spectroscopy, we measured D(PCr) in the calf muscle of 11 adults as a function of direction and diffusion time. The results show that the diffusion of PCr is anisotropic, with significantly higher diffusion along the muscle fibers, and that the diffusion of PCr is restricted to a ∼28-μm pathlength assuming a cylindrical model, with an unbounded diffusion coefficient of ∼0.69 × 10(-3) mm(2)/s. This distance is comparable in size to the myofiber radius. On the basis of prior measures of CK reaction kinetics in human muscle, the expected diffusion distance of PCr during its half-life in the CK reaction is ∼66 μm. This distance is much greater than the average distances between mitochondria and myofibrils. Thus these first measurements of PCr diffusion in human muscle in vivo support the view that PCr diffusion is not a factor limiting high-energy phosphate transport between the mitochondria and the myofibrils in healthy resting myocytes.

  20. Muscle Weakness Is Associated With an Increase of Left Ventricular Mass Through Excessive Blood Pressure Elevation During Exercise in Patients With Hypertension.

    Kamada, Yumi; Masuda, Takashi; Tanaka, Shinya; Akiyama, Ayako; Nakamura, Takeshi; Hamazaki, Nobuaki; Okubo, Michihito; Kobayashi, Naoyuki; Ako, Junya

    2017-08-03

    Autonomic imbalance in hypertension induces excessive blood pressure (BP) elevation during exercise, thereby increasing left ventricular mass (LVM). Although muscle weakness enhances autonomic imbalance by stimulating muscle sympathetic activity during exercise, it is unclear whether muscle weakness is associated with an increase of LVM in patients with hypertension. This study aimed to investigate the relationships between muscle weakness, BP elevation during exercise, and LVM in these patients. Eighty-six hypertensive patients aged 69 ± 8 years with controlled resting BP (ie, exercise test performed at moderate intensity (ΔNORA and ΔPWV, respectively). A difference between baseline and peak systolic BP during the exercise test was defined as BP elevation during exercise (ΔSBP). Relationships between muscle strength, ΔNORA, ΔPWV, ΔSBP, BNP, and LVMI were analyzed, and significant factors increasing LVM were identified using univariate and multivariate regression analyses. Muscle strength was negatively correlated with ΔNORA (r = -0.202, P = 0.048), ΔPWV (r = -0.328, P = 0.002), ΔSBP (r = -0.230, P = 0.033), BNP (r = -0.265, P = 0.014), and LVMI (r = -0.233, P = 0.031). LVMI was positively correlated with ΔPWV (r = 0.246, P = 0.023) and ΔSBP (r = 0.307, P = 0.004). Muscle strength was a significant independent factor associated with LVMI (β = -0.331, P = 0.010). Our findings suggest that muscle weakness is associated with an increase of LVM through excessive BP elevation during exercise in patients with hypertension.

  1. Changes in muscle cross-sectional area, muscle force, and jump performance during 6 weeks of progressive whole-body vibration combined with progressive, high intensity resistance training

    Rosenberger, A.; Beijer, Å.; Johannes, B.; Schoenau, E.; Mester, J.; Rittweger, J.; Zange, J.

    2017-01-01

    Objectives: We hypothesized that progressive whole-body vibration (WBV) superimposed to progressive high intensity resistance training has greater effects on muscle cross-sectional area (CSA), muscle force of leg muscles, and jump performance than progressive high intensity resistance training alone. Methods: Two groups of healthy male subjects performed either 6 weeks of Resistive Vibration Exercise (RVE, squats and heel raises with WBV, n=13) or Resistive Exercise (RE, squats and heel raises without WBV, n=13). Squats under RVE required indispensable weight loading on the forefoot to damp harmful vibrations to the head. Time, intervention, and interaction effects were analyzed. Results: After 6 weeks of training, knee extensor CSA, isometric knee extension force, and counter movement jump height increased equally in both groups (time effect, P<0.001, P≤0.02, and P≤0.03, respectively), whereas only in RVE ankle plantar flexor CSA and isometric ankle plantar flexion force reached significance or a tendency, respectively, (time effect, P=0.015 and P=0.069, respectively; intervention effect also for the latter, P=0.006). Drop jump contact time did significantly more improve in RVE (interaction effect, P=0.042). Conclusions: RVE showed better training effects than RE only in plantar flexor muscles. RVE seems to be suitable in professional sports with a special focus on calf muscles. PMID:28574410

  2. High Multiplicity Searches at the LHC Using Jet Masses

    Hook, Anson; /SLAC /Stanford U., Appl. Phys. Dept.; Izaguirre, Eder; /SLAC /Stanford U., Phys. Dept.; Lisanti, Mariangela; /Princeton U.; Wacker, Jay G.; /SLAC /Stanford U., ITP

    2012-04-24

    This article introduces a new class of searches for physics beyond the Standard Model that improves the sensitivity to signals with high jet multiplicity. The proposed searches gain access to high multiplicity signals by reclustering events into large-radius, or 'fat', jets and by requiring that each event has multiple massive jets. This technique is applied to supersymmetric scenarios in which gluinos are pair-produced and then subsequently decay to final states with either moderate quantities of missing energy or final states without missing energy. In each of these scenarios, the use of jet mass improves the estimated reach in gluino mass by 20% to 50% over current LHC searches.

  3. Oxidative DNA damage and repair in skeletal muscle of humans exposed to high-altitude hypoxia

    Lundby, Carsten; Pilegaard, Henriette; Hall, Gerrit van; Sander, Mikael; Calbet, Jose; Loft, Steffen; Moeller, Peter

    2003-01-01

    Recent research suggests that high-altitude hypoxia may serve as a model for prolonged oxidative stress in healthy humans. In this study, we investigated the consequences of prolonged high-altitude hypoxia on the basal level of oxidative damage to nuclear DNA in muscle cells, a major oxygen-consuming tissue. Muscle biopsies from seven healthy humans were obtained at sea level and after 2 and 8 weeks of hypoxia at 4100 m.a.s.l. We found increased levels of strand breaks and endonuclease III-sensitive sites after 2 weeks of hypoxia, whereas oxidative DNA damage detected by formamidopyrimidine DNA glycosylase (FPG) protein was unaltered. The expression of 8-oxoguanine DNA glycosylase 1 (OGG1), determined by quantitative RT-PCR of mRNA levels did not significantly change during high-altitude hypoxia, although the data could not exclude a minor upregulation. The expression of heme oxygenase-1 (HO-1) was unaltered by prolonged hypoxia, in accordance with the notion that HO-1 is an acute stress response protein. In conclusion, our data indicate high-altitude hypoxia may serve as a good model for oxidative stress and that antioxidant genes are not upregulated in muscle tissue by prolonged hypoxia despite increased generation of oxidative DNA damage

  4. High temperature mass spectrometry for thermodynamic study of radioactive materials

    Pattoret, Andre; Philippot, Joseph; Pesme, Olivier.

    1983-01-01

    Thermodynamic properties and evaporation kinetics are essential data to evaluate the nuclear fuel behaviour under accidental conditions. High temperature mass spectrometry appears as a valuable method to set up a such assessment. However, because of size, complexity and radioactivity of the irradiated samples, important improvements of the classical method are required. The device built in CEN/FAR to overcome these problems is described; performances and possible applications out of the nuclear safety field are presented [fr

  5. Liquid chromatography – tandem mass spectrometry method for the determination of ten tetracycline residues in muscle samples

    Gajda Anna

    2015-09-01

    Full Text Available A liquid chromatography – tandem mass spectrometry (LC-MS/MS method for the determination of oxytetracycline (OTC, 4-epi oxytetracycline (4-epi OTC, tetracycline (TC, 4-epi tetracycline (4-epi TC, chlortetracycline (CTC, 4-epi chlortetracycline (4-epi CTC, doxycycline (DC, minocycline (MINO, methacycline (META and rolitetracycline (ROLI residues in muscles was developed. The procedure consisted of an oxalic acid extraction followed by protein removal with trichloroacetic acid. Further solid phase clean-up on polymeric (Strata X reversed phase columns was performed to obtain an extract suitable for LC-MS/MS analysis. The tetracyclines were separated on a C 18 analytical column with mobile phase consisting of 0.01% formic acid in acetonitrile and 0.01% formic acid in water in gradient mode. The method was validated according to the Commission Decision 2002/657/EC. The recoveries of all target compounds were 91.8% – 103.6%. The decision limits were from 109.0 to 119.8 μg/kg and detection capability varied within the range of 122.2 to 137.6 μg/kg, depending on the analyte.

  6. Investigation of the high mass Drell Yan spectrum with ATLAS

    Mueller, Thomas A.

    2010-01-01

    The Large Hadron Collider started data taking at the end of 2009 and an integrated luminosity of 1fb -1 is hoped for by the end of 2011. A precise measurement of the high mass Drell Yan spectrum offers a good opportunity for a model independent search for new physics. The muon channel is well suited for this, due to the clean signature and the good muon identification in the Muon Spectrometer. Previous studies at high dimuon masses neglected all background contributions. This study investigated the impact of background on the Drell Yan spectrum and it was found that t anti t decays are the most important contribution. Various selection cuts to suppress those background contributions were studied. A method to take systematic uncertainties into account, whilst optimising these selection cuts, has been developed. It was shown that two additional selection cuts based on b-tagging and Missing Transverse Energy (E T ) will reduce the overall uncertainty for a bin from 200 GeV to 300 GeV from 19.1% to 17.2% for an integrated luminosity of 50 pb -1 . An important aspect of this analysis is to ensure that the efficiency for all selection cuts remains stable at very high dimuon masses of up to 1 TeV. This is not the case for the conventional missing E T , so a derived variable has been introduced and tested. (orig.)

  7. Investigation of the high mass Drell Yan spectrum with ATLAS

    Mueller, Thomas A

    2010-09-14

    The Large Hadron Collider started data taking at the end of 2009 and an integrated luminosity of 1fb{sup -1} is hoped for by the end of 2011. A precise measurement of the high mass Drell Yan spectrum offers a good opportunity for a model independent search for new physics. The muon channel is well suited for this, due to the clean signature and the good muon identification in the Muon Spectrometer. Previous studies at high dimuon masses neglected all background contributions. This study investigated the impact of background on the Drell Yan spectrum and it was found that t anti t decays are the most important contribution. Various selection cuts to suppress those background contributions were studied. A method to take systematic uncertainties into account, whilst optimising these selection cuts, has been developed. It was shown that two additional selection cuts based on b-tagging and Missing Transverse Energy (E{sub T}) will reduce the overall uncertainty for a bin from 200 GeV to 300 GeV from 19.1% to 17.2% for an integrated luminosity of 50 pb{sup -1}. An important aspect of this analysis is to ensure that the efficiency for all selection cuts remains stable at very high dimuon masses of up to 1 TeV. This is not the case for the conventional missing E{sub T}, so a derived variable has been introduced and tested. (orig.)

  8. Integrative Analyses of miRNA-mRNA Interactions Reveal let-7b, miR-128 and MAPK Pathway Involvement in Muscle Mass Loss in Sex-Linked Dwarf Chickens

    Luo, Wen; Lin, Shumao; Li, Guihuan; Nie, Qinghua; Zhang, Xiquan

    2016-01-01

    The sex-linked dwarf (SLD) chicken is an ideal model system for understanding growth hormone (GH)-action and growth hormone receptor (GHR) function because of its recessive mutation in the GHR gene. Skeletal muscle mass is reduced in the SLD chicken with a smaller muscle fiber diameter. Our previous study has presented the mRNA and miRNA expression profiles of the SLD chicken and normal chicken between embryo day 14 and seven weeks of age. However, the molecular mechanism of GHR-deficient induced muscle mass loss is still unclear, and the key molecules and pathways underlying the GHR-deficient induced muscle mass loss also remain to be illustrated. Here, by functional network analysis of the differentially expressed miRNAs and mRNAs between the SLD and normal chickens, we revealed that let-7b, miR-128 and the MAPK pathway might play key roles in the GHR-deficient induced muscle mass loss, and that the reduced cell division and growth are potential cellular processes during the SLD chicken skeletal muscle development. Additionally, we also found some genes and miRNAs involved in chicken skeletal muscle development, through the MAPK, PI3K-Akt, Wnt and Insulin signaling pathways. This study provides new insights into the molecular mechanism underlying muscle mass loss in the SLD chickens, and some regulatory networks that are crucial for chicken skeletal muscle development. PMID:26927061

  9. Mass Customisation and Highly Individualised Solutions. Stretching Mass Customisation Beyond the Traditional Paradigm of Industrial Production

    Morelli, Nicola; Nielsen, Louise Møller

    2007-01-01

    and consumption patterns. The reference to a paradigm shift helps emphasising the inherent limits of industrial production and the elements of changes brought about by the possibility to generate highly individualised solutions. The concept of mass customisation was introduced to extend the domain of industrial...... production beyond its original limitations, however it is strongly linked to the paradigm of industrial production and not always usable to support and explain new ways of organising value creation. This paper proposes an analysis of this paradigm shift through three cases, which emphasise some elements...... of mass customisation that are still relevant to the new paradigm. At the same time the paper emphasises the limits of this concept and the need for a new perspective view to interpret the ongoing change in production and consumption systems....

  10. Linking high resolution mass spectrometry data with exposure ...

    There is a growing need in the field of exposure science for monitoring methods that rapidly screen environmental media for suspect contaminants. Measurement and analysis platforms, based on high resolution mass spectrometry (HRMS), now exist to meet this need. Here we describe results of a study that links HRMS data with exposure predictions from the U.S. EPA's ExpoCast™ program and in vitro bioassay data from the U.S. interagency Tox21 consortium. Vacuum dust samples were collected from 56 households across the U.S. as part of the American Healthy Homes Survey (AHHS). Sample extracts were analyzed using liquid chromatography time-of-flight mass spectrometry (LC–TOF/MS) with electrospray ionization. On average, approximately 2000 molecular features were identified per sample (based on accurate mass) in negative ion mode, and 3000 in positive ion mode. Exact mass, isotope distribution, and isotope spacing were used to match molecular features with a unique listing of chemical formulas extracted from EPA's Distributed Structure-Searchable Toxicity (DSSTox) database. A total of 978 DSSTox formulas were consistent with the dust LC–TOF/molecular feature data (match score ≥ 90); these formulas mapped to 3228 possible chemicals in the database. Correct assignment of a unique chemical to a given formula required additional validation steps. Each suspect chemical was prioritized for follow-up confirmation using abundance and detection frequency results, along wi

  11. High-energy phosphate transfer in human muscle: diffusion of phosphocreatine

    Gabr, Refaat E.; El-Sharkawy, AbdEl-Monem M.; Schär, Michael; Weiss, Robert G.; Bottomley, Paul A.

    2011-01-01

    The creatine kinase (CK) reaction is central to muscle energetics, buffering ATP levels during periods of intense activity via consumption of phosphocreatine (PCr). PCr is believed to serve as a spatial shuttle of high-energy phosphate between sites of energy production in the mitochondria and sites of energy utilization in the myofibrils via diffusion. Knowledge of the diffusion coefficient of PCr (DPCr) is thus critical for modeling and understanding energy transport in the myocyte, but DPC...

  12. Impact of low skeletal muscle mass on non-lung cancer mortality after stereotactic body radiotherapy for patients with stage I non-small cell lung cancer.

    Matsuo, Yukinori; Mitsuyoshi, Takamasa; Shintani, Takashi; Iizuka, Yusuke; Mizowaki, Takashi

    2018-05-17

    The purpose of the present study was to retrospectively evaluate impact of pre-treatment skeletal muscle mass (SMM) on overall survival and non-lung cancer mortality after stereotactic body radiotherapy (SBRT) for patients with stage I non-small cell lung cancer (NSCLC). One-hundred and eighty-six patients whose abdominal CT before the treatment was available were enrolled into this study. The patients were divided into two groups of SMM according to gender-specific thresholds for unilateral psoas area. Operability was judged by the treating physician or thoracic surgeon after discussion in a multi-disciplinary tumor board. Patients with low SMM tended to be elderly and underweight in body mass index compared with the high SMM. Overall survival in patients with the low SMM tended to be worse than that in the high SMM (41.1% and 55.9% at 5 years, P = 0.115). Cumulative incidence of non-lung cancer death was significantly worse in the low SMM (31.3% at 5 years compared with 9.7% in the high SMM, P = 0.006). Multivariate analysis identified SMM and operability as significant factors for non-lung cancer mortality. Impact of SMM on lung cancer death was not significant. No difference in rate of severe treatment-related toxicity was observed between the SMM groups. Low SMM is a significant risk factor for non-lung cancer death, which might lead to worse overall survival, after SBRT for stage I NSCLC. However, the low SMM does not increase lung cancer death or severe treatment-related toxicity. Copyright © 2018 Elsevier Inc. All rights reserved.

  13. Whole-body electromyostimulation as a means to impact muscle mass and abdominal body fat in lean, sedentary, older female adults: subanalysis of the TEST-III trial

    Kemmler W

    2013-10-01

    Full Text Available Wolfgang Kemmler, Simon von StengelInstitute of Medical Physics, University of Erlangen-Nürnberg, Erlangen, GermanyBackground: The primary aim of this study was to determine the effect of 12 months of whole-body electromyostimulation (WB-EMS exercise on appendicular muscle mass and abdominal fat mass in subjects specifically at risk for sarcopenia and abdominal obesity, but unable or unwilling to exercise conventionally.Methods: Forty-six lean, nonsportive (<60 minutes of exercise per week, elderly women (aged 75 ± 4 years with abdominal obesity according to International Diabetes Federation criteria were randomly assigned to either a WB-EMS group (n=23 which performed 18 minutes of intermittent, bipolar WB-EMS (85 Hz three sessions in 14 days or an "active" control group (n=23. Whole-body and regional body composition was assessed by dual energy X-ray absorptiometry to determine appendicular muscle mass, upper leg muscle mass, abdominal fat mass, and upper leg fat mass. Maximum strength of the leg extensors was determined isometrically by force plates.Results: After 12 months, significant intergroup differences were detected for the primary endpoints of appendicular muscle mass (0.5% ± 2.0% for the WB-EMS group versus −0.8% ± 2.0% for the control group, P=0.025 and abdominal fat mass (−1.2% ± 5.9% for the WB-EMS group versus 2.4% ± 5.8% for the control group, P=0.038. Further, upper leg lean muscle mass changed favorably in the WB-EMS group (0.5% ± 2.5% versus −0.9% ± 1.9%, in the control group, P=0.033, while effects for upper leg fat mass were borderline nonsignificant (−0.8% ± 3.5% for the WB-EMS group versus 1.0% ± 2.6% for the control group, P=0.050. With respect to functional parameters, the effects for leg extensor strength were again significant, with more favorable changes in the WB-EMS group (9.1% ± 11.2% versus 1.0% ± 8.1% in the control group, P=0.010.Conclusion: In summary, WB-EMS showed positive effects on the

  14. Efficacy of phosphatidic acid ingestion on lean body mass, muscle thickness and strength gains in resistance-trained men

    Hoffman Jay R

    2012-10-01

    Full Text Available Abstract Background Phosphatidic acid (PA has been reported to activate the mammalian target of rapamycin (mTOR signaling pathway and is thought to enhance the anabolic effects of resistance training. The purpose of this pilot study was to examine if oral phosphatidic acid administration can enhance strength, muscle thickness and lean tissue accruement during an 8-week resistance training program. Methods Sixteen resistance-trained men were randomly assigned to a group that either consumed 750 mg of PA (n = 7, 23.1 ± 4.4 y; 176.7 ± 6.7 cm; 86.5 ± 21.2 kg or a placebo (PL, n = 9, 22.5 ± 2.0 y; 179.8 ± 5.4 cm; 89.4 ± 13.6 kg group. During each testing session subjects were assessed for strength (one repetition maximum [1-RM] bench press and squat and body composition. Muscle thickness and pennation angle were also measured in the vastus lateralis of the subject’s dominant leg. Results Subjects ingesting PA demonstrated a 12.7% increase in squat strength and a 2.6% increase in LBM, while subjects consuming PL showed a 9.3% improvement in squat strength and a 0.1% change in LBM. Although parametric analysis was unable to demonstrate significant differences, magnitude based inferences indicated that the Δ change in 1-RM squat showed a likely benefit from PA on increasing lower body strength and a very likely benefit for increasing lean body mass (LBM. Conclusions Results of this study suggest that a combination of a daily 750 mg PA ingestion, combined with a 4-day per week resistance training program for 8-weeks appears to have a likely benefit on strength improvement, and a very likely benefit on lean tissue accruement in young, resistance trained individuals.

  15. Determination of multiresidue analysis of β-agonists in muscle and viscera using liquid chromatograph/tandem mass spectrometry with Quick, Easy, Cheap, Effective, Rugged, and Safe methodologies

    Yen-Ping Lin

    2017-04-01

    Full Text Available The official analytical method of the Taiwan Food and Drug Administration, Ministry of Health and Welfare for testing for veterinary drug residues in foods is the multiresidue analysis of β-agonists. Samples are pretreated through liquid–liquid extraction and solid-phase extraction. This method is time consuming and requires the intensive use of solvents. To improve analytical efficiency and reduce costs, our study incorporated QuEChERS (Quick, Easy, Cheap, Effective, Rugged, and Safe techniques to establish a new method of multiresidue analysis of β-agonists in animal muscle and viscera. The pretreatment time was shortened and solvent usage was minimized. The modified analysis was conducted using liquid chromatography/tandem mass spectrometry (LC–MS/MS and quantification was performed using multiple reaction monitoring. The results demonstrated that the correlation coefficients of the tissue calibration curve were higher than 0.99 and the limit of quantification (LOQ was 1 ppb. The average recoveries in spiked samples varied from 70% to 120%, and the relative difference between duplicated analysis results was lower than 10%. On the basis of the results, the proposed method was concluded to be an appropriate procedure for determining the presence of β-agonists, and demonstrated the advantages of high recovery rates in spiked samples, high precision, reduced analysis time and solvent usage, and lower costs.

  16. Searches for High-Mass $tt^-$ Resonances at CMS

    Mc Lean, Christine Angela

    2016-01-01

    We present a search for new massive particles decaying to a pair of top quarks with the CMS detector at the LHC. Proton-proton collision data recorded at a centre-of-mass energy of 13 TeV are used. The search is performed by measuring the invariant mass distribution of the top-quark pair and testing for deviations from the expected Standard Model background. Final states with 0 or 1 leptons are considered and the selection optimised accordingly. In the high mass ranges accessible by the LHC at these energies the top quarks are produced with high transverse momentum the products of hadronically decaying top quarks emerge as a single jet, whereas the products of the semileptonic decay mode are characterised by the overlap of the lepton to the b jet. Specific reconstruction algorithm and selections are employed to address the identification of boosted top quark signatures. The results are presented in terms of upper limits on the model cross section. Models of Randall-Sundrum Kaluza-Klein gluon production as wel...

  17. Interdependence of physical inactivity, loss of muscle mass and low dietary intake: Extrapulmonary manifestations in older chronic obstructive pulmonary disease patients.

    Yoshimura, Kazuya; Sato, Susumu; Muro, Shigeo; Yamada, Minoru; Hasegawa, Koichi; Kiyokawa, Hirofumi; Mishima, Michiaki; Aoyama, Tomoki

    2018-01-01

    Extrapulmonary manifestations, such as reductions in skeletal muscle and physical inactivity, are important clinical features of patients with chronic obstructive pulmonary disease (COPD), and might depend on the severity of COPD. As it is still unclear whether the relationship between muscle loss and physical inactivity is dominated by a disease-specific relationship or caused by patient factors, including physiological aging, we aimed to investigate the pulmonary or extrapulmonary factors associated with physical inactivity among older COPD patients. A total of 38 older male COPD patients (aged ≥65 years) were enrolled, and were evaluated cross-sectionally. Skeletal muscle mass was measured using bioelectrical impedance, and physical activity and energy intake were recorded for 2 weeks using a pedometer and diary. Daily step counts were successfully evaluated in 28 participants (mean forced expiratory volume in 1 s [%predicted; %FEV 1 ]; 49.5%), and ranged widely. The mean step counts was 5166 steps/day, and found to have a significant relationship with dyspnea (r = -0.46), diffusing capacity (r = 0.47), %FEV1 (r = 0.44), skeletal muscle index (r = 0.59) and total dietary intake (r = 0.47), but not with age (P = 0.14). A stepwise multivariate analysis showed that the skeletal muscle index (β = 0.50) and total dietary intake (β = 0.35) were significant determinants of the daily step count (R 2 = 0.46, p physical activity, skeletal muscle mass and dietary intake are more closely correlated with physical activity in COPD patients. Because physical inactivity might be the strongest predictor of prognosis, the present results suggest that a comprehensive treatment strategy must be considered for older COPD patients to improve their extrapulmonary manifestations and pulmonary dysfunction. Geriatr Gerontol Int 2018; 18: 88-94. © 2017 Japan Geriatrics Society.

  18. Muscle fibre capillarization is a critical factor in muscle fibre hypertrophy during resistance exercise training in older men.

    Snijders, Tim; Nederveen, Joshua P; Joanisse, Sophie; Leenders, Marika; Verdijk, Lex B; van Loon, Luc J C; Parise, Gianni

    2017-04-01

    Adequate muscle fibre perfusion is critical for the maintenance of muscle mass; it is essential in the rapid delivery of oxygen, nutrients and growth factors to the muscle, stimulating muscle fibre growth. Muscle fibre capillarization is known to decrease substantially with advancing age. However, whether (relative) low muscle fibre capillarization negatively impacts the muscle hypertrophic response following resistance exercise training in older adults is unknown. Twenty-two healthy older men (71 ± 1 years) performed 24 weeks of progressive resistance type exercise training. To assess the change in muscle fibre characteristics, percutaneous biopsies from the vastus lateralis muscle were taken before and following 12 and 24 weeks of the intervention programme. A comparison was made between participants who had a relatively low type II muscle fibre capillary-to-fibre perimeter exchange index (CFPE; LOW group) and high type II muscle fibre CFPE (HIGH group) at baseline. Type I and type II muscle fibre size, satellite cell, capillary content and distance between satellite cells to the nearest capillary were determined by immunohistochemistry. Overall, type II muscle fibre size (from 5150 ± 234 to 6719 ± 446 µm 2 , P muscle fibre, P muscle fibre capillarization, whereas muscle fibre size (from 5170 ± 390 to 7133 ± 314 µm 2 , P muscle fibre, P muscle fibre capillarization were observed in response to 12 and 24 weeks of resistance exercise training in both the LOW and HIGH group. Type II muscle fibre capillarization at baseline may be a critical factor for allowing muscle fibre hypertrophy to occur during prolonged resistance exercise training in older men. © 2016 The Authors. Journal of Cachexia, Sarcopenia and Muscle published by John Wiley & Sons Ltd on behalf of the Society on Sarcopenia, Cachexia and Wasting Disorders.

  19. High-frequency irreversible electroporation (H-FIRE for non-thermal ablation without muscle contraction

    Arena Christopher B

    2011-11-01

    Full Text Available Abstract Background Therapeutic irreversible electroporation (IRE is an emerging technology for the non-thermal ablation of tumors. The technique involves delivering a series of unipolar electric pulses to permanently destabilize the plasma membrane of cancer cells through an increase in transmembrane potential, which leads to the development of a tissue lesion. Clinically, IRE requires the administration of paralytic agents to prevent muscle contractions during treatment that are associated with the delivery of electric pulses. This study shows that by applying high-frequency, bipolar bursts, muscle contractions can be eliminated during IRE without compromising the non-thermal mechanism of cell death. Methods A combination of analytical, numerical, and experimental techniques were performed to investigate high-frequency irreversible electroporation (H-FIRE. A theoretical model for determining transmembrane potential in response to arbitrary electric fields was used to identify optimal burst frequencies and amplitudes for in vivo treatments. A finite element model for predicting thermal damage based on the electric field distribution was used to design non-thermal protocols for in vivo experiments. H-FIRE was applied to the brain of rats, and muscle contractions were quantified via accelerometers placed at the cervicothoracic junction. MRI and histological evaluation was performed post-operatively to assess ablation. Results No visual or tactile evidence of muscle contraction was seen during H-FIRE at 250 kHz or 500 kHz, while all IRE protocols resulted in detectable muscle contractions at the cervicothoracic junction. H-FIRE produced ablative lesions in brain tissue that were characteristic in cellular morphology of non-thermal IRE treatments. Specifically, there was complete uniformity of tissue death within targeted areas, and a sharp transition zone was present between lesioned and normal brain. Conclusions H-FIRE is a feasible technique for

  20. The additional value of bioelectrical impedance analysis-derived muscle mass as a screening tool in geriatric assessment for fall prevention.

    Van Puyenbroeck, Karolien; Roelandts, Lieven; Van Deun, Thomas; Van Royen, Paul; Verhoeven, Veronique

    2012-01-01

    The decline in skeletal muscle in old age is a factor in the development of functional limitations. The objective of this study was to assess if there is a correlation between muscle mass based on bioelectrical impedance analysis (BIA) detection and the fall incidence in nursing home residents and to examine the risk factors for falling in nursing home residents. This prospective cohort study was part of a longitudinal study on nutritional issues in 52 nursing homes in Antwerp (Belgium) from October 2007 to April 2008. Two hundred and seventy-six people aged 65 years and older were included. Each subject was assessed with BIA, the timed get-up-and-go test, the Katz score, the Mini Nutritional Assessment - Short Form and the 36-Item Short Form Health Survey. The primary outcome parameter was fall incidence during the study. The prevalence of sarcopenia varied from 24.3 to 81.5% depending on which definition was used. No association was found between BIA-derived muscle mass and fall incidence. Logistic regression analysis showed that gait speed (odds ratio 1.029; p = 0.003) and mental health (odds ratio 0.981; p = 0.015) are significantly associated with fall incidence in nursing homes. A receiver operating characteristic curve showed that none of the BIA-derived muscle parameters are good predictors of the risk of falling. This study shows that there is no association between sarcopenia based on BIA and fall incidence and that BIA-derived muscle mass has no additional value in predicting fall incidents compared to the timed get-up-and-go test. Copyright © 2012 S. Karger AG, Basel.

  1. High levels of N-palmitoylethanolamide and N-stearoylethanolamide in microdialysate samples from myalgic trapezius muscle in women.

    Nazdar Ghafouri

    Full Text Available BACKGROUND: N-acylethanolamines (NAEs are endogenous compounds that regulate inflammation and pain. These include the cannabinoid ligand anandamide (AEA and the peroxisome proliferator-activated receptor-α ligand palmitoylethanolamide (PEA. Little is known as to the levels of NAEs in pain states in human, particularly in the skeletal muscle. The aim of this study was to investigate the levels of these lipid mediators in muscle dialysate from women with chronic neck-/shoulder pain compared to healthy controls. METHODS: Eleven women with chronic neck-/shoulder pain and eleven healthy women participated in this study. All participants went through microdialysis procedures in the trapezius muscle. Muscle dialysate samples were collected during four hours and analysed by nano liquid chromatography tandem mass spectrometry (nLC-MS/MS. RESULTS: We were able to detect AEA, PEA, N-stearoylethanolamine (SEA and 2-arachidonoylglycerol (2-AG in a single chromatographic run. Of the NAEs studied, PEA and SEA were clearly detectable in the muscle microdialysate samples. The muscle dialysate levels of PEA and SEA were significantly higher in myalgic subjects compared to healthy controls. CONCLUSION: This study demonstrates that microdialysis in combination with mass spectrometry can be used for analysing NAE's in human muscle tissue regularly over time. Furthermore the significant group differences in the concentration of PEA and SEA in this study might fill an important gap in our knowledge of mechanisms in chronic myalgia in humans. In the long run this expanded understanding of nociceptive and anitinociceptive processes in the muscle may provide a base for ameliorating treatment and rehabilitation of pain.

  2. Modeling and experiments on the drive characteristics of high-strength water hydraulic artificial muscles

    Zhang, Zengmeng; Hou, Jiaoyi; Ning, Dayong; Gong, Xiaofeng; Gong, Yongjun

    2017-05-01

    Fluidic artificial muscles are popular in robotics and function as biomimetic actuators. Their pneumatic version has been widely investigated. A novel water hydraulic artificial muscle (WHAM) with high strength is developed in this study. WHAMs can be applied to underwater manipulators widely used in ocean development because of their environment-friendly characteristics, high force-to-weight ratio, and good bio-imitability. Therefore, the strength of WHAMs has been improved to fit the requirements of underwater environments and the work pressure of water hydraulic components. However, understanding the mechanical behaviors of WHAMs is necessary because WHAMs use work media and pressure control that are different from those used by pneumatic artificial muscles. This paper presents the static and dynamic characteristics of the WHAM system, including the water hydraulic pressure control circuit. A test system is designed and built to analyze the drive characteristics of the developed WHAM. The theoretical relationships among the amount of contraction, pressure, and output drawing force of the WHAM are tested and verified. A linearized transfer function is proposed, and the dynamic characteristics of the WHAM are investigated through simulation and inertia load experiments. Simulation results agree with the experimental results and show that the proposed model can be applied to the control of WHAM actuators.

  3. Maternal high fat diet alters skeletal muscle mitochondrial catalytic activity in adult male rat offspring.

    Chantal Anne Pileggi

    2016-11-01

    Full Text Available A maternal high-fat (HF diet during pregnancy can lead to metabolic compromise such as insulin resistance in adult offspring. Skeletal muscle mitochondrial dysfunction is one mechanism contributing to metabolic impairments in insulin resistant states. Therefore, the present study aimed to investigate whether mitochondrial dysfunction is evident in metabolically compromised offspring born to HF-fed dams. Sprague-Dawley dams were randomly assigned to receive a purified control diet (CD; 10% kcal from fat or a high fat diet (HFD; 45% kcal from fat for 10 days prior to mating, throughout pregnancy and during lactation. From weaning, all male offspring received a standard chow diet and soleus muscle was collected at day 150. Expression of the mitochondrial transcription factors nuclear respiratory factor-1 (NRF1 and mitochondrial transcription factor A (mtTFA were downregulated in HF offspring. Furthermore, genes encoding the mitochondrial electron transport system (ETS respiratory complex subunits were supressed in HF offspring. Moreover, protein expression of the complex I subunit, NDUFB8, was downregulated in HF offspring (36%, which was paralleled by decreased maximal catalytic linked activity of complex I and III (40%. Together, these results indicate that exposure to a maternal HF diet during development may elicit lifelong mitochondrial alterations in offspring skeletal muscle.

  4. Influence of hamstring muscles extensibility on spinal curvatures and pelvic tilt in highly trained cyclists.

    Muyor, José M; Alacid, Fernando; López-Miñarro, Pedro A

    2011-09-01

    The purpose of this study was to determine the influence of hamstring muscles extensibility in standing, maximal trunk flexion with knees extended and on the bicycle in lower handlebar-hands position of highly trained cyclists. Ninety-six cyclists were recruited for the study (mean ± SD, age: 30.36 ± 5.98 years). Sagittal spinal curvatures and pelvic tilt were measured in the standing position, maximal trunk flexion with knees extended (sit-and-reach test) and while sitting on a bicycle in lower handlebar-hand position using a Spinal Mouse system. Hamstring muscles extensibility was determined in both legs by passive straight leg raise test (PSLR). The sample was divided into three groups according to PSLR angle: (1) reduced extensibility (PSLR hamstring extensibility group (PSLR = 80º - 90º; n = 35), and (3) high hamstring extensibility (PSLR = > 90º; n = 31). ANOVA analysis showed significant differences among groups for thoracic (p hamstring muscles extensibility influence the thoracic and pelvic postures when maximal trunk flexion with knees extended is performed, but not when cyclists are seated on their bicycles.

  5. Concurrent Label-Free Mass Spectrometric Analysis of Dystrophin Isoform Dp427 and the Myofibrosis Marker Collagen in Crude Extracts from mdx-4cv Skeletal Muscles

    Murphy, Sandra; Zweyer, Margit; Mundegar, Rustam R.; Henry, Michael; Meleady, Paula; Swandulla, Dieter; Ohlendieck, Kay

    2015-01-01

    The full-length dystrophin protein isoform of 427 kDa (Dp427), the absence of which represents the principal abnormality in X-linked muscular dystrophy, is difficult to identify and characterize by routine proteomic screening approaches of crude tissue extracts. This is probably related to its large molecular size, its close association with the sarcolemmal membrane, and its existence within a heterogeneous glycoprotein complex. Here, we used a careful extraction procedure to isolate the total protein repertoire from normal versus dystrophic mdx-4cv skeletal muscles, in conjunction with label-free mass spectrometry, and successfully identified Dp427 by proteomic means. In contrast to a considerable number of previous comparative studies of the total skeletal muscle proteome, using whole tissue proteomics we show here for the first time that the reduced expression of this membrane cytoskeletal protein is the most significant alteration in dystrophinopathy. This agrees with the pathobiochemical concept that the almost complete absence of dystrophin is the main defect in Duchenne muscular dystrophy and that the mdx-4cv mouse model of dystrophinopathy exhibits only very few revertant fibers. Significant increases in collagens and associated fibrotic marker proteins, such as fibronectin, biglycan, asporin, decorin, prolargin, mimecan, and lumican were identified in dystrophin-deficient muscles. The up-regulation of collagen in mdx-4cv muscles was confirmed by immunofluorescence microscopy and immunoblotting. Thus, this is the first mass spectrometric study of crude tissue extracts that puts the proteomic identification of dystrophin in its proper pathophysiological context. PMID:28248273

  6. Assessment of muscle mass and its association with protein intake in a multi-ethnic Asian population: relevance in chronic kidney disease.

    Teo, Boon Wee; Toh, Qi Chun; Chan, Xue Wei; Xu, Hui; Li, Jia Liang; Lee, Evan Jc

    2014-01-01

    Clinical practice guidelines recommend objective nutritional assessments in managing chronic kidney disease (CKD) patients but were developed while referencing to a North-American population. Specific recommendations for assessing muscle mass were suggested (mid-arm circumference, MAC; corrected mid-arm muscle area, cAMA; mid-arm muscle circumference, MAMC). This study aimed to assess correlation and association of these assessments with dietary protein intake in a multi-ethnic Asian population of healthy and CKD patients. We analyzed 24-hour urine collections of selected participants to estimate total protein intake (TPI; g/day). Ideal body weight (IDW; kg) was calculated and muscle assessments conducted. Analyses involved correlation and linear regression, taking significance at ppatients and 103 healthy participants comprising of 51.0% male, 38.5% Chinese, 29.6% Malay, 23.6% Indian, and 8.4% others. The mean TPI was 58.9 ± 18.4 g/day in healthy participants and 53.6 ± 19.4 g/day in CKD patients. When normalized to ideal body weight, TPI-IDW (g/kg/day) was similar in healthy and CKD participants. Overall, TPI was associated with MAC (r=0.372, ppatients. Total protein intake was associated with muscle assessments in all participants. TPI normalized to IDW should only be used in CKD patients.

  7. Skeletal muscle collagen content in humans after high-force eccentric contractions

    Mackey, Abigail; Donnelly, Alan E; Turpeenniemi-Hujanen, Taina

    2004-01-01

    The purpose of this study was to investigate the effects of high-force eccentric muscle contractions on collagen remodeling and on circulating levels of matrix metalloproteinases (MMP) and tissue inhibitors of metalloproteinases (TIMP) in humans. Nine volunteers [5 men and 4 women, mean age 23 (SD...... 4) yr] each performed a bout of 100 maximum voluntary eccentric contractions of the knee extensors. Muscle biopsies were taken before exercise and on days 4 and 22 afterward. Image analysis of stained tissue sections was used to quantify endomysial collagen staining intensity. Maximum voluntary...... contractile force declined by 39 +/- 23% (mean +/- SD) on day 2 postexercise and recovered thereafter. Serum creatine kinase activity peaked on day 4 postexercise (P Collagen type IV staining intensity increased significantly on day 22 postexercise to 126 +/- 29% (mean +/- SD) of preexercise values...

  8. Effect of a high protein diet and/or resistance exercise on the preservation of fat free mass during weight loss in overweight and obese older adults : a randomized controlled trial

    Verreijen, Amely M; Engberink, Mariëlle F; Memelink, Robert G; van der Plas, Suzanne E; Visser, Marjolein; Weijs, Peter J M

    2017-01-01

    BACKGROUND: Intentional weight loss in obese older adults is a risk factor for accelerated muscle mass loss. We investigated whether a high protein diet and/or resistance exercise preserves fat free mass (FFM) during weight loss in overweight and obese older adults. METHODS: We included 100

  9. High-frequency, low-magnitude vibration does not prevent bone loss resulting from muscle disuse in mice following botulinum toxin injection.

    Manske, Sarah L; Good, Craig A; Zernicke, Ronald F; Boyd, Steven K

    2012-01-01

    High-frequency, low-magnitude vibration enhances bone formation ostensibly by mimicking normal postural muscle activity. We tested this hypothesis by examining whether daily exposure to low-magnitude vibration (VIB) would maintain bone in a muscle disuse model with botulinum toxin type A (BTX). Female 16-18 wk old BALB/c mice (N = 36) were assigned to BTX-VIB, BTX-SHAM, VIB, or SHAM. BTX mice were injected with BTX (20 µL; 1 U/100 g body mass) into the left hindlimb posterior musculature. All mice were anaesthetized for 20 min/d, 5 d/wk, for 3 wk, and the left leg mounted to a holder. Through the holder, VIB mice received 45 Hz, ± 0.6 g sinusoidal acceleration without weight bearing. SHAM mice received no vibration. At baseline and 3 wk, muscle cross-sectional area (MCSA) and tibial bone properties (epiphysis, metaphysis and diaphysis) were assessed by in vivo micro-CT. Bone volume fraction in the metaphysis decreased 12 ± 9% and 7 ± 6% in BTX-VIB and BTX-SHAM, but increased in the VIB and SHAM. There were no differences in dynamic histomorphometry outcomes between BTX-VIB and BTX nor between VIB and SHAM. Thus, vibration did not prevent bone loss induced by a rapid decline in muscle activity nor produce an anabolic effect in normal mice. The daily loading duration was shorter than would be expected from postural muscle activity, and may have been insufficient to prevent bone loss. Based on the approach used in this study, vibration does not prevent bone loss in the absence of muscle activity induced by BTX.

  10. High-frequency, low-magnitude vibration does not prevent bone loss resulting from muscle disuse in mice following botulinum toxin injection.

    Sarah L Manske

    Full Text Available High-frequency, low-magnitude vibration enhances bone formation ostensibly by mimicking normal postural muscle activity. We tested this hypothesis by examining whether daily exposure to low-magnitude vibration (VIB would maintain bone in a muscle disuse model with botulinum toxin type A (BTX. Female 16-18 wk old BALB/c mice (N = 36 were assigned to BTX-VIB, BTX-SHAM, VIB, or SHAM. BTX mice were injected with BTX (20 µL; 1 U/100 g body mass into the left hindlimb posterior musculature. All mice were anaesthetized for 20 min/d, 5 d/wk, for 3 wk, and the left leg mounted to a holder. Through the holder, VIB mice received 45 Hz, ± 0.6 g sinusoidal acceleration without weight bearing. SHAM mice received no vibration. At baseline and 3 wk, muscle cross-sectional area (MCSA and tibial bone properties (epiphysis, metaphysis and diaphysis were assessed by in vivo micro-CT. Bone volume fraction in the metaphysis decreased 12 ± 9% and 7 ± 6% in BTX-VIB and BTX-SHAM, but increased in the VIB and SHAM. There were no differences in dynamic histomorphometry outcomes between BTX-VIB and BTX nor between VIB and SHAM. Thus, vibration did not prevent bone loss induced by a rapid decline in muscle activity nor produce an anabolic effect in normal mice. The daily loading duration was shorter than would be expected from postural muscle activity, and may have been insufficient to prevent bone loss. Based on the approach used in this study, vibration does not prevent bone loss in the absence of muscle activity induced by BTX.

  11. High-temperature mechanical properties of high-purity 70 mass% Cr-Fe alloy

    Asahina, M.; Harima, N.; Takaki, S.; Abiko, K. [Tohoku Univ., Sendai (Japan). Inst. for Materials Research

    2002-01-16

    An ingot of high-purity 70 mass% Cr-Fe alloy was prepared by high-frequency induction melting in a high-purity argon atmosphere using a cold copper crucible. Its tensile properties such as hot-ductility and tensile strength were measured, and compared with the results for a high-purity 50 mass% Cr-Fe alloy, a high-purity 60 mass% Cr-Fe alloy and a Ni-based super-alloy. The formation of {sigma}-phase was also examined. The purity of a 70Cr-Fe alloy (70 mass% Cr-Fe alloy) ingot is more than 99.98 mass% and the total amount of gaseous impurities (C, N, O, S, H) in the 70Cr-Fe alloy is 69.9 mass ppm. The strength of the 70Cr-Fe alloy is higher than those of the 60Cr-Fe alloy and the 50Cr-Fe alloy at the temperatures between 293 and 1573 K, without decrease in ductility with increasing Cr content. The 70Cr-Fe alloy also possesses excellent high-temperature ductility. The {sigma}-phase was not observed after aging of 3.6 Ms at 873 K. Consequently, the 70Cr-Fe alloy is an excellent alloy as the base of super heat-resistant alloys. (orig.)

  12. A high precision semi-analytic mass function

    Del Popolo, Antonino [Dipartimento di Fisica e Astronomia, University of Catania, Viale Andrea Doria 6, I-95125 Catania (Italy); Pace, Francesco [Jodrell Bank Centre for Astrophysics, School of Physics and Astronomy, The University of Manchester, Manchester, M13 9PL (United Kingdom); Le Delliou, Morgan, E-mail: adelpopolo@oact.inaf.it, E-mail: francesco.pace@manchester.ac.uk, E-mail: delliou@ift.unesp.br [Instituto de Física Teorica, Universidade Estadual de São Paulo (IFT-UNESP), Rua Dr. Bento Teobaldo Ferraz 271, Bloco 2—Barra Funda, 01140-070 São Paulo, SP Brazil (Brazil)

    2017-03-01

    In this paper, extending past works of Del Popolo, we show how a high precision mass function (MF) can be obtained using the excursion set approach and an improved barrier taking implicitly into account a non-zero cosmological constant, the angular momentum acquired by tidal interaction of proto-structures and dynamical friction. In the case of the ΛCDM paradigm, we find that our MF is in agreement at the 3% level to Klypin's Bolshoi simulation, in the mass range M {sub vir} = 5 × 10{sup 9} h {sup −1} M {sub ⊙}–−5 × 10{sup 14} h {sup −1} M {sub ⊙} and redshift range 0 ∼< z ∼< 10. For z = 0 we also compared our MF to several fitting formulae, and found in particular agreement with Bhattacharya's within 3% in the mass range 10{sup 12}–10{sup 16} h {sup −1} M {sub ⊙}. Moreover, we discuss our MF validity for different cosmologies.

  13. Mass

    Quigg, Chris

    2007-01-01

    In the classical physics we inherited from Isaac Newton, mass does not arise, it simply is. The mass of a classical object is the sum of the masses of its parts. Albert Einstein showed that the mass of a body is a measure of its energy content, inviting us to consider the origins of mass. The protons we accelerate at Fermilab are prime examples of Einsteinian matter: nearly all of their mass arises from stored energy. Missing mass led to the discovery of the noble gases, and a new form of missing mass leads us to the notion of dark matter. Starting with a brief guided tour of the meanings of mass, the colloquium will explore the multiple origins of mass. We will see how far we have come toward understanding mass, and survey the issues that guide our research today.

  14. High body mass index is associated with impaired cognitive control.

    Sellaro, Roberta; Colzato, Lorenza S

    2017-06-01

    The prevalence of weight problems is increasing worldwide. There is growing evidence that high body mass index (BMI) is associated with frontal lobe dysfunction and cognitive deficits concerning mental flexibility and inhibitory control efficiency. The present study aims at replicating and extending these observations. We compared cognitive control performance of normal weight (BMI task tapping either inhibitory control (Experiment 1) or interference control (Experiment 2). Experiment 1 replicated previous findings that found less efficient inhibitory control in overweight individuals. Experiment 2 complemented these findings by showing that cognitive control impairments associated with high BMI also extend to the ability to resolve stimulus-induced response conflict and to engage in conflict-driven control adaptation. The present results are consistent with and extend previous literature showing that high BMI in young, otherwise healthy individuals is associated with less efficient cognitive control functioning. Copyright © 2017 Elsevier Ltd. All rights reserved.

  15. Alterations in Muscle Mass and Contractile Phenotype in Response to Unloading Models: Role of