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Sample records for human body muscles

  1. Glycogen synthesis in human gastrocnemius muscle is not representative of whole-body muscle glycogen synthesis.

    NARCIS (Netherlands)

    Serlie, M.J.; Haan, J.H.A. de; Tack, C.J.J.; Verberne, H.J.; Ackermans, M.T.; Heerschap, A.; Sauerwein, H.P.

    2005-01-01

    The introduction of 13C magnetic resonance spectroscopy (MRS) has enabled noninvasive measurement of muscle glycogen synthesis in humans. Conclusions based on measurements by the MRS technique assume that glucose metabolism in gastrocnemius muscle is representative for all skeletal muscles and thus

  2. Finite element crash simulations of the human body: Passive and active muscle modelling

    Indian Academy of Sciences (India)

    S Mukherjee; A Chawla; B Karthikeyan; A Soni

    2007-08-01

    Conventional dummy based testing procedures suffer from known limitations. This report addresses issues in finite element human body models in evaluating pedestrian and occupant crash safety measures. A review of material properties of soft tissues and characterization methods show a scarcity of material properties for characterizing soft tissues in dynamic loading. Experiments imparting impacts to tissues and subsequent inverse finite element mapping to extract material properties are described. The effect of muscle activation due to voluntary and non-voluntary reflexes on injuries has been investigated through finite element modelling.

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

    Science.gov (United States)

    Clark, Richard V; 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

    2014-06-15

    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.

  4. Automated segmentation of muscle and adipose tissue on CT images for human body composition analysis

    Science.gov (United States)

    Chung, Howard; Cobzas, Dana; Birdsell, Laura; Lieffers, Jessica; Baracos, Vickie

    2009-02-01

    The ability to compute body composition in cancer patients lends itself to determining the specific clinical outcomes associated with fat and lean tissue stores. For example, a wasting syndrome of advanced disease associates with shortened survival. Moreover, certain tissue compartments represent sites for drug distribution and are likely determinants of chemotherapy efficacy and toxicity. CT images are abundant, but these cannot be fully exploited unless there exist practical and fast approaches for tissue quantification. Here we propose a fully automated method for segmenting muscle, visceral and subcutaneous adipose tissues, taking the approach of shape modeling for the analysis of skeletal muscle. Muscle shape is represented using PCA encoded Free Form Deformations with respect to a mean shape. The shape model is learned from manually segmented images and used in conjunction with a tissue appearance prior. VAT and SAT are segmented based on the final deformed muscle shape. In comparing the automatic and manual methods, coefficients of variation (COV) (1 - 2%), were similar to or smaller than inter- and intra-observer COVs reported for manual segmentation.

  5. Estimate of the lower-limb-specific muscle parameters during bipedal walking for humans, apes and early hominids with the implications for the evolution of body proportion

    Institute of Scientific and Technical Information of China (English)

    Wang Weijie

    2007-01-01

    Modern human has different body proportion from early hominids and great apes. Comparing with others, in general, modern human adults have relatively long lower limb and heavier body weight. Since the lower limbs provide support to the whole body and play an important role in walking, it is proposed that the ratio of the lower limb to the whole body for modern human could be beneficial to bipedal walking. This study tried to estimate the muscle parameters of the lower limb in walking for the subjects with various body proportions. Using a simplified musculoskeletal model, some muscle parameters of the lower limb, e.g. muscle force, stress, work and power, were estimated for modern human adult, child, AL 288-1 (the fossil specimens of Australopithecus afarensis, 3.18 million years old) and apes. The results show that with the body proportion modern human adult spends less muscle work and power in walking than other subjects. The results imply that using the cost of transport (i.e. the muscle work of the lower limb per unit of displacement) as the criteria, the early hominids, if their body proportions were structurally similar to AL 288-1, could evolve towards what modern human adult looks like, in order to save energy during bipedal walking.

  6. Human Muscle Power Output during Upper- and Lower-Body Exercises.

    Science.gov (United States)

    Siegel, Judith A.; Gilders, Roger M.; Staron, Robert S.; Hagerman, Fredrick C.

    2002-01-01

    Evaluated the use of traditional resistance training equipment in measuring muscular power, measuring the velocity of movement through a measured distance during maximal effort lifts using a Smith rack. Data collected on male volunteers indicated that this method of evaluating muscle power was reliable, although it was not predictive of muscle…

  7. Growth hormone signaling in muscle and adipose tissue of obese human subjects: associations with measures of body composition and interaction with resveratrol treatment.

    Science.gov (United States)

    Clasen, Berthil F; Poulsen, Morten M; Escande, Carlos; Pedersen, Steen B; Møller, Niels; Chini, Eduardo N; Jessen, Niels; Jørgensen, Jens O L

    2014-12-01

    Growth hormone (GH) secretion is reduced in obesity, despite normal serum insulin-like growth factor I (IGF-1) levels, but the association between obesity and the GH signaling is unknown. Furthermore, SIRT1, an nicotinamide adenine dinucleotide-dependent protein deacetylase, reduces hepatic IGF-1 production in mice via blunting of GH-induced STAT5 signaling. To study GH signaling in muscle and fat in obese subjects and the interaction with concomitant administration of the putative SIRT1 activator resveratrol, and to assess the effects of inhibiting or knocking down SIRT1 on GH regulated genes in vitro. Twenty-four obese males were examined in a randomized, double blinded, parallel-group study with resveratrol or placebo treatment for 5 weeks followed by a GH bolus. Muscle and fat biopsies were collected before and after GH. Body composition was assessed by DEXA and MRI. (1) Effect of body composition and age on GH-stimulated STAT5b phosphorylation and IGF-1, SOCS2, and CISH mRNA in muscle and fat. (2) The impact of resveratrol treatment on GH activity. (3) Impact of inhibiting or knocking down SIRT1 on effects of GH in vitro. Significant GH-induced STAT5b phosphorylation in muscle and fat in obese subjects was recorded together with increased CISH and SOCS2 mRNA. GH-induced STAT5b phosphorylation in muscle correlated positively with age [r = 0.53, p < 0.01], but not with body composition. Resveratrol administration had no impact on body composition, serum IGF-1, or GH signaling in vivo, and SIRT1 knock down or inhibition did not affect GH signaling in vitro. (1) GH induced STAT5b phosphorylation is detectable in muscle and fat in adult males with simple obesity, but is not determined by body composition. (2) Resveratrol supplementation does not impact circulating IGF-1 levels or GH signaling in human muscle and fat. (3) Our data speak against a major impact of SIRT1on GH action in human subjects.

  8. The potential for mitochondrial fat oxidation in human skeletal muscle influences whole body fat oxidation during low-intensity exercise.

    Science.gov (United States)

    Sahlin, K; Mogensen, M; Bagger, M; Fernström, M; Pedersen, P K

    2007-01-01

    The purpose of this study was to investigate fatty acid (FA) oxidation in isolated mitochondrial vesicles (mit) and its relation to training status, fiber type composition, and whole body FA oxidation. Trained (Vo(2 peak) 60.7 +/- 1.6, n = 8) and untrained subjects (39.5 +/- 2.0 ml.min(-1).kg(-1), n = 5) cycled at 40, 80, and 120 W, and whole body relative FA oxidation was assessed from respiratory exchange ratio (RER). Mit were isolated from muscle biopsies, and maximal ADP stimulated respiration was measured with carbohydrate-derived substrate [pyruvate + malate (Pyr)] and FA-derived substrate [palmitoyl-l-carnitine + malate (PC)]. Fiber type composition was determined from analysis of myosin heavy-chain (MHC) composition. The rate of mit oxidation was lower with PC than with Pyr, and the ratio between PC and Pyr oxidation (MFO) varied greatly between subjects (49-93%). MFO was significantly correlated to muscle fiber type distribution, i.e., %MHC I (r = 0.62, P = 0.03), but was not different between trained (62 +/- 5%) and untrained subjects (72 +/- 2%). MFO was correlated to RER during submaximal exercise at 80 (r = -0.62, P = 0.02) and 120 W (r = -0.71, P = 0.007) and interpolated 35% Vo(2 peak) (r = -0.74, P = 0.004). ADP sensitivity of mit respiration was significantly higher with PC than with Pyr. It is concluded that MFO is influenced by fiber type composition but not by training status. The inverse correlation between RER and MFO implies that intrinsic mit characteristics are of importance for whole body FA oxidation during low-intensity exercise. The higher ADP sensitivity with PC than that with Pyr may influence fuel utilization at low rate of respiration.

  9. Physics of the Human Body

    CERN Document Server

    Herman, Irving P

    2007-01-01

    Physics of the Human Body comprehensively addresses the physical and engineering aspects of human physiology by using and building on first-year college physics and mathematics. Topics include the mechanics of the static body and the body in motion, the materials properties of the body, muscles in the body, the energetics of body metabolism, fluid flow in the cardiovascular and respiratory systems, the acoustics of sound waves in speaking and hearing, vision and the optics of the eye, the electrical properties of the body, and the basic engineering principles of feedback and control in regulating all aspects of function. The goal of this text is to understand physical issues concerning the human body, in part by developing and then using simple and subsequently more refined models of the macrophysics of the human body. Many chapters include a brief review of the necessary physical principles. There are problems at the end of each chapter; solutions to selected problems are also provided. This text is geared t...

  10. Plasma adiponectin concentration is associated with skeletal muscle insulin receptor tyrosine phosphorylation, and low plasma concentration precedes a decrease in whole-body insulin sensitivity in humans.

    Science.gov (United States)

    Stefan, Norbert; Vozarova, Barbora; Funahashi, Tohru; Matsuzawa, Yuji; Weyer, Christian; Lindsay, Robert S; Youngren, Jack F; Havel, Peter J; Pratley, Richard E; Bogardus, Clifton; Tataranni, P Antonio

    2002-06-01

    Adiponectin, the most abundant adipose-specific protein, has been found to be negatively associated with degree of adiposity and positively associated with insulin sensitivity in Pima Indians and other populations. Moreover, adiponectin administration to rodents has been shown to increase insulin-induced tyrosine phosphorylation of the insulin receptor (IR) and also increase whole-body insulin sensitivity. To further characterize the relationship between plasma adiponectin concentration and insulin sensitivity in humans, we examined 1) the cross-sectional association between plasma adiponectin concentration and skeletal muscle IR tyrosine phosphorylation and 2) the prospective effect of plasma adiponectin concentration at baseline on change in insulin sensitivity. Fasting plasma adiponectin concentration, body composition (hydrodensitometry or dual energy X-ray absorptiometry), insulin sensitivity (insulin-stimulated glucose disposal, hyperinsulinemic clamp), and glucose tolerance (75-g oral glucose tolerance test) were measured in 55 Pima Indians (47 men and 8 women, aged 31 +/- 8 years, body fat 29 +/- 8% [mean +/- SD]; 50 with normal glucose tolerance, 3 with impaired glucose tolerance, and 2 with diabetes). Group 1 (19 subjects) underwent skeletal muscle biopsies for the measurement of basal and insulin-stimulated tyrosine phosphorylation of the IR (stimulated by 100 nmol/l insulin). The fold increase after insulin stimulation was calculated as the ratio between maximal and basal phosphorylation. Group 2 (38 subjects) had follow-up measurements of insulin-stimulated glucose disposal. Cross-sectionally, plasma adiponectin concentration was positively associated with insulin-stimulated glucose disposal (r = 0.58, P < 0.0001) and negatively associated with percent body fat (r = -0.62, P < 0.0001) in the whole group. In group 1 plasma adiponectin was negatively associated with the basal (r = -0.65, P = 0.003) and positively associated with the fold increase in IR

  11. Plasma adiponectin concentration is associated with skeletal muscle insulin receptor tyrosine phosphorylation, and low plasma concentration precedes a decrease in whole-body insulin sensitivity in humans

    DEFF Research Database (Denmark)

    Stefan, Norbert; Vozarova, Barbora; Funahashi, Tohru;

    2002-01-01

    -induced tyrosine phosphorylation of the insulin receptor (IR) and also increase whole-body insulin sensitivity. To further characterize the relationship between plasma adiponectin concentration and insulin sensitivity in humans, we examined 1) the cross-sectional association between plasma adiponectin......Adiponectin, the most abundant adipose-specific protein, has been found to be negatively associated with degree of adiposity and positively associated with insulin sensitivity in Pima Indians and other populations. Moreover, adiponectin administration to rodents has been shown to increase insulin...... concentration and skeletal muscle IR tyrosine phosphorylation and 2) the prospective effect of plasma adiponectin concentration at baseline on change in insulin sensitivity. Fasting plasma adiponectin concentration, body composition (hydrodensitometry or dual energy X-ray absorptiometry), insulin sensitivity...

  12. Effects of acute pinitol supplementation on plasma pinitol concentration, whole body glucose tolerance, and activation of the skeletal muscle insulin receptor in older humans.

    Science.gov (United States)

    Stull, A J; Wood, K V; Thyfault, J P; Campbell, W W

    2009-05-01

    Limited research with rodents and humans suggests that oral ingestion of pinitol (3- O-methyl- D- CHIRO-inositol) might positively influence glucose tolerance. This double-blinded, placebo-controlled, and cross-over study assessed the effects of acute pinitol supplementation on plasma pinitol concentration, glucose tolerance, insulin sensitivity, and activation of the skeletal muscle insulin receptor. Fifteen older, nondiabetic subjects (62+/-1 years, mean+/-SEM) completed four, 1-day trials. Subjects consumed a non-nutritive beverage with nothing (placebo) or 1,000 mg pinitol. Sixty minutes later, the subjects consumed beverages that were either energy- and carbohydrate-free (Sham) or contained 75 g glucose (OGTT). Blood samples were collected frequently over the 240-min testing period. For the OGTT trials only, vastus lateralis samples were obtained before the placebo and pinitol supplementation and 60 min after consuming the 75 g glucose beverage. Plasma pinitol concentration increased and was maintained for 240 min. Pinitol did not influence the fasting state and 180-min area under the curves for plasma glucose and insulin during the Sham and OGTT trials or hepatic (placebo 0.83+/-0.08; pinitol 0.80+/-0.08) and whole-body (placebo 6.10+/-0.54; pinitol 6.22+/-0.52) insulin sensitivities. Activation of the muscle insulin receptor was increased by 140% with glucose ingestion (Pre 0.62+/-0.12; Post 1.49+/-0.35), but pinitol did not influence this response. These results show that the pinitol supplement was quickly absorbed, but did not acutely influence indices of whole-body glucose tolerance and insulin sensitivity, or the activation of the skeletal muscle insulin receptor in older, nondiabetic humans.

  13. Physics of the human body

    CERN Document Server

    Herman, Irving P

    2016-01-01

    This book comprehensively addresses the physics and engineering aspects of human physiology by using and building on first-year college physics and mathematics. Topics include the mechanics of the static body and the body in motion, the mechanical properties of the body, muscles in the body, the energetics of body metabolism, fluid flow in the cardiovascular and respiratory systems, the acoustics of sound waves in speaking and hearing, vision and the optics of the eye, the electrical properties of the body, and the basic engineering principles of feedback and control in regulating all aspects of function. The goal of this text is to clearly explain the physics issues concerning the human body, in part by developing and then using simple and subsequently more refined models of the macrophysics of the human body. Many chapters include a brief review of the underlying physics. There are problems at the end of each chapter; solutions to selected problems are also provided. This second edition enhances the treat...

  14. Regulation of Metabolic Signaling in Human Skeletal Muscle

    DEFF Research Database (Denmark)

    Albers, Peter Hjorth

    sensitivity in type I muscle fibers possibly reflects a superior effect of insulin on metabolic signaling compared to type II muscle fibers. This was investigated in the present thesis by examining muscle biopsies from lean and obese healthy subjects as well as patients with type 2 diabetes. From these muscle...... enzymes. Skeletal muscle consists of thousands of muscle fibers. These fibers can roughly be classified into type I and type II muscle fibers. The overall aim of this PhD thesis was to investigate the effect of insulin and exercise on human muscle fiber type specific metabolic signaling. The importance...... of human type I muscle fibers is illustrated by the finding of a positive correlation between the relative distribution of type I fibers in the muscle and whole-body insulin sensitivity. This suggests, that type I muscle fibers are more insulin sensitive than type II muscle fibers. Improved insulin...

  15. The Human Skeletal Muscle Proteome Project

    DEFF Research Database (Denmark)

    Gonzalez-Freire, Marta; Semba, Richard D.; Ubaida-Mohien, Ceereena

    2017-01-01

    Skeletal muscle is a large organ that accounts for up to half the total mass of the human body. A progressive decline in muscle mass and strength occurs with ageing and in some individuals configures the syndrome of ‘sarcopenia’, a condition that impairs mobility, challenges autonomy, and is a risk...... factor for mortality. The mechanisms leading to sarcopenia as well as myopathies are still little understood. The Human Skeletal Muscle Proteome Project was initiated with the aim to characterize muscle proteins and how they change with ageing and disease. We conducted an extensive review...... of the literature and analysed publically available protein databases. A systematic search of peer-reviewed studies was performed using PubMed. Search terms included ‘human’, ‘skeletal muscle’, ‘proteome’, ‘proteomic(s)’, and ‘mass spectrometry’, ‘liquid chromatography-mass spectrometry (LC-MS/MS)’. A catalogue...

  16. Multichannel Human Body Communication

    Science.gov (United States)

    Przystup, Piotr; Bujnowski, Adam; Wtorek, Jerzy

    2016-01-01

    Human Body Communication is an attractive alternative for traditional wireless communication (Bluetooth, ZigBee) in case of Body Sensor Networks. Low power, high data rates and data security makes it ideal solution for medical applications. In this paper, signal attenuation for different frequencies, using FR4 electrodes, has been investigated. Performance of single and multichannel transmission with frequency modulation of analog signal has been tested. Experiment results show that HBC is a feasible solution for transmitting data between BSN nodes.

  17. Computational human body models

    NARCIS (Netherlands)

    Wismans, J.S.H.M.; Happee, R.; Dommelen, J.A.W. van

    2005-01-01

    Computational human body models are widely used for automotive crashsafety research and design and as such have significantly contributed to a reduction of traffic injuries and fatalities. Currently crash simulations are mainly performed using models based on crash-dummies. However crash dummies dif

  18. Computational human body models

    NARCIS (Netherlands)

    Wismans, J.S.H.M.; Happee, R.; Dommelen, J.A.W. van

    2005-01-01

    Computational human body models are widely used for automotive crashsafety research and design and as such have significantly contributed to a reduction of traffic injuries and fatalities. Currently crash simulations are mainly performed using models based on crash-dummies. However crash dummies

  19. Evaluation of Body Weight, Body Condition, and Muscle Condition in Cats with Hyperthyroidism.

    Science.gov (United States)

    Peterson, M E; Castellano, C A; Rishniw, M

    2016-11-01

    The contribution of fat loss versus muscle wasting to the loss of body weight seen in hyperthyroid cats is unknown. To investigate body weight, body condition score (BCS), and muscle condition score (MCS) in hyperthyroid cats. Four hundred sixty-two cats with untreated hyperthyroidism, 117 of which were reevaluated after treatment. Prospective cross-sectional and before-after studies. Untreated hyperthyroid cats had body composition evaluated (body weight, BCS, and MCS). A subset of these cats were reevaluated 3-12 months after treatment when euthyroid. Pretreatment body weight (median, 4.36 kg; IQR, 3.5 to 5.2 kg) was lower than premorbid weight (5.45 kg; IQR, 4.6 to 6.4 kg, P weight (median, 4.1 kg to 5.0 kg), BCS (median, 3/5 to 3.5/5), and MCS (2/3 to 3/3) after treatment (P weight but maintain an ideal or overweight BCS, with only a third being underweight. As in human hyperthyroid patients, this weight loss is associated with muscle wasting, which affects >75% of hyperthyroid cats. Successful treatment leads to weight gain and increase of BCS in most cats, but almost half fail to regain normal muscle mass. Copyright © 2016 The Authors. Journal of Veterinary Internal Medicine published by Wiley Periodicals, Inc. on behalf of the American College of Veterinary Internal Medicine.

  20. Insulin does not stimulate muscle protein synthesis during increased plasma branched-chain amino acids alone but still decreases whole body proteolysis in humans.

    Science.gov (United States)

    Everman, Sarah; Meyer, Christian; Tran, Lee; Hoffman, Nyssa; Carroll, Chad C; Dedmon, William L; Katsanos, Christos S

    2016-10-01

    Insulin stimulates muscle protein synthesis when the levels of total amino acids, or at least the essential amino acids, are at or above their postabsorptive concentrations. Among the essential amino acids, branched-chain amino acids (BCAA) have the primary role in stimulating muscle protein synthesis and are commonly sought alone to stimulate muscle protein synthesis in humans. Fourteen healthy young subjects were studied before and after insulin infusion to examine whether insulin stimulates muscle protein synthesis in relation to the availability of BCAA alone. One half of the subjects were studied in the presence of postabsorptive BCAA concentrations (control) and the other half in the presence of increased plasma BCAA (BCAA). Compared with that prior to the initiation of the insulin infusion, fractional synthesis rate of muscle protein (%/h) did not change (P > 0.05) during insulin in either the control (0.04 ± 0.01 vs 0.05 ± 0.01) or the BCAA (0.05 ± 0.02 vs. 0.05 ± 0.01) experiments. Insulin decreased (P BCAA (0.89 ± 0.07 vs 0.61 ± 0.03) experiments, but the change was not different between the two experiments (P > 0.05). In conclusion, insulin does not stimulate muscle protein synthesis in the presence of increased circulating levels of plasma BCAA alone. Insulin's suppressive effect on proteolysis is observed independently of the levels of circulating plasma BCAA.

  1. Trichinella spiralis in human muscle (image)

    Science.gov (United States)

    This is the parasite Trichinella spiralis in human muscle tissue. The parasite is transmitted by eating undercooked ... produce large numbers of larvae that migrate into muscle tissue. The cysts may cause muscle pain and ...

  2. Simulation of rear end impact with a full body human model with a detailed neck: role of passive muscle properties and initial seating posture

    NARCIS (Netherlands)

    Happee, R.; Wismans, J.S.H.M.; Horst, M.J. van der; Bovendeerd, P.H.M.; Kingma, H.

    2001-01-01

    To study the mechanics of the neck during rear end impact, in this paper an existing global human body model and an existing detailed submodel of the neck were combined into a new model. The combined model is validated with responses of volunteers and post mortem human subjects (PMHSs) subjected to

  3. Effects of Acute Pinitol Supplementation on Plasma Pinitol Concentration, Whole Body Glucose Tolerance, and Activation of the Skeletal Muscle Insulin Receptor in Older Humans

    OpenAIRE

    Stull, A. J.; Wood, K V; Thyfault, J. P.; Campbell, W.W.

    2009-01-01

    Limited research with rodents and humans suggests that oral ingestion of pinitol (3-O-methyl-d-chiro-inositol) might positively influence glucose tolerance. This double-blinded, placebo-controlled, and cross-over study assessed the effects of acute pinitol supplementation on plasma pinitol concentration, glucose tolerance, insulin sensitivity, and activation of the skeletal muscle insulin receptor. Fifteen older, nondiabetic subjects (62 ± 1 years, mean ± SEM) completed four, 1-day trials. Su...

  4. Determining the Sub-Cellular Localization of Proteins within Caenorhabditis elegans Body Wall Muscle

    Science.gov (United States)

    Viveiros, Ryan; Warner, Adam; Plastino, Lorena; Lorch, Adam; Granger, Laure; Segalat, Laurent; Moerman, Donald G.

    2011-01-01

    Determining the sub-cellular localization of a protein within a cell is often an essential step towards understanding its function. In Caenorhabditis elegans, the relatively large size of the body wall muscle cells and the exquisite organization of their sarcomeres offer an opportunity to identify the precise position of proteins within cell substructures. Our goal in this study is to generate a comprehensive “localizome” for C. elegans body wall muscle by GFP-tagging proteins expressed in muscle and determining their location within the cell. For this project, we focused on proteins that we know are expressed in muscle and are orthologs or at least homologs of human proteins. To date we have analyzed the expression of about 227 GFP-tagged proteins that show localized expression in the body wall muscle of this nematode (e.g. dense bodies, M-lines, myofilaments, mitochondria, cell membrane, nucleus or nucleolus). For most proteins analyzed in this study no prior data on sub-cellular localization was available. In addition to discrete sub-cellular localization we observe overlapping patterns of localization including the presence of a protein in the dense body and the nucleus, or the dense body and the M-lines. In total we discern more than 14 sub-cellular localization patterns within nematode body wall muscle. The localization of this large set of proteins within a muscle cell will serve as an invaluable resource in our investigation of muscle sarcomere assembly and function. PMID:21611156

  5. Human body communication performance simulations

    OpenAIRE

    Mufti, H. (Haseeb)

    2016-01-01

    Human Body Communication (HBC) is a novel communication method between devices which use human body as a transmission medium. This idea is mostly based on the concept of wireless biomedical monitoring system. The on-body sensor nodes can monitor vital signs of a human body and use the body as a transmission medium. This technology is convenient for long durations of clinical monitoring with the option of more mobility and freedom for the user. In this thesis, IEEE 802.15.6-2012 phy...

  6. Development of the ventral body wall in the human embryo.

    Science.gov (United States)

    Mekonen, Hayelom K; Hikspoors, Jill P J M; Mommen, Greet; Köhler, S Eleonore; Lamers, Wouter H

    2015-11-01

    Migratory failure of somitic cells is the commonest explanation for ventral body wall defects. However, the embryo increases ~ 25-fold in volume in the period that the ventral body wall forms, so that differential growth may, instead, account for the observed changes in topography. Human embryos between 4 and 10 weeks of development were studied, using amira reconstruction and cinema 4D remodeling software for visualization. Initially, vertebrae and ribs had formed medially, and primordia of sternum and hypaxial flank muscle primordium laterally in the body wall at Carnegie Stage (CS)15 (5.5 weeks). The next week, ribs and muscle primordium expanded in ventrolateral direction only. At CS18 (6.5 weeks), separate intercostal and abdominal wall muscles differentiated, and ribs, sterna, and muscles began to expand ventromedially and caudally, with the bilateral sternal bars fusing in the midline after CS20 (7 weeks) and the rectus muscles reaching the umbilicus at CS23 (8 weeks). The near-constant absolute distance between both rectus muscles and approximately fivefold decline of this distance relative to body circumference between 6 and 10 weeks identified dorsoventral growth in the dorsal body wall as determinant of the 'closure' of the ventral body wall. Concomitant with the straightening of the embryonic body axis after the 6th week, the abdominal muscles expanded ventrally and caudally to form the infraumbilical body wall. Our data, therefore, show that the ventral body wall is formed by differential dorsoventral growth in the dorsal part of the body.

  7. Esterase profile of human masseter muscle

    DEFF Research Database (Denmark)

    Kirkeby, S; Moe, D; Vilmann, H

    1988-01-01

    The esterase profile of fresh human masseter muscle was investigated by use of histochemistry and electrophoresis. The histochemical methods included reactions for alpha-naphthyl esterase, myofibrillar ATPase, reverse myofibrillar ATPase and succinic dehydrogenase. In frozen sections of the muscl...

  8. Breathing modes, body positions, and suprahyoid muscle activity.

    Science.gov (United States)

    Takahashi, S; Ono, T; Ishiwata, Y; Kuroda, T

    2002-12-01

    To determine (1) how electromyographic activities of the genioglossus and geniohyoid muscles can be differentiated, and (2) whether changes in breathing modes and body positions have effects on the genioglossus and geniohyoid muscle activities. Ten normal subjects participated in the study. Electromyographic activities of both the genioglossus and geniohyoid muscles were recorded during nasal and oral breathing, while the subject was in the upright and supine positions. The electromyographic activities of the genioglossus and geniohyoid muscles were compared during jaw opening, swallowing, mandibular advancement, and tongue protrusion. The geniohyoid muscle showed greater electromyographic activity than the genioglossus muscle during maximal jaw opening. In addition, the geniohyoid muscle showed a shorter (P breathing modes and body positions, while there were no significant differences in the geniohyoid muscle activity. Electromyographic activities from the genioglossus and geniohyoid muscles are successfully differentiated. In addition, it appears that changes in the breathing mode and body position significantly affect the genioglossus muscle activity, but do not affect the geniohyoid muscle activity.

  9. Muscle fiber and motor unit behavior in the longest human skeletal muscle.

    Science.gov (United States)

    Harris, A John; Duxson, Marilyn J; Butler, Jane E; Hodges, Paul W; Taylor, Janet L; Gandevia, Simon C

    2005-09-14

    The sartorius muscle is the longest muscle in the human body. It is strap-like, up to 600 mm in length, and contains five to seven neurovascular compartments, each with a neuromuscular endplate zone. Some of its fibers terminate intrafascicularly, whereas others may run the full length of the muscle. To assess the location and timing of activation within motor units of this long muscle, we recorded electromyographic potentials from multiple intramuscular electrodes along sartorius muscle during steady voluntary contraction and analyzed their activity with spike-triggered averaging from a needle electrode inserted near the proximal end of the muscle. Approximately 30% of sartorius motor units included muscle fibers that ran the full length of the muscle, conducting action potentials at 3.9 +/- 0.1 m/s. Most motor units were innervated within a single muscle endplate zone that was not necessarily near the midpoint of the fiber. As a consequence, action potentials reached the distal end of a unit as late as 100 ms after initiation at an endplate zone. Thus, contractile activity is not synchronized along the length of single sartorius fibers. We postulate that lateral transmission of force from fiber to endomysium and a wide distribution of motor unit endplates along the muscle are critical for the efficient transmission of force from sarcomere to tendon and for the prevention of muscle injury caused by overextension of inactive regions of muscle fibers.

  10. Muscle spindles in the human bulbospongiosus and ischiocavernosus muscles.

    Science.gov (United States)

    Peikert, Kevin; May, Christian Albrecht

    2015-07-01

    Muscle spindles are crucial for neuronal regulation of striated muscles, but their presence and involvement in the superficial perineal muscles is not known. Bulbospongiosus and ischiocavernosus muscle specimens were obtained from 31 human cadavers. Serial sections were stained with hematoxylin and eosin, Sirius red, antibodies against Podocalyxin, myosin heavy chain isoforms (MyHC-slow tonic, S46; MyHC-2a/2x, A4.74), and neurofilament for the purpose of muscle spindle screening, counting, and characterization. A low but consistent number of spindles were detected in both muscles. The muscles contained few intrafusal fibers, but otherwise showed normal spindle morphology. The extrafusal fibers of both muscles were small in diameter. The presence of muscle spindles in bulbospongiosus and ischiocavernosus muscles supports physiological models of pelvic floor regulation and may provide a basis for further clinical observations regarding sexual function and micturition. The small number of muscle spindles points to a minor level of proprioceptive regulation. © 2014 Wiley Periodicals, Inc.

  11. Satellite cells in human skeletal muscle plasticity.

    Science.gov (United States)

    Snijders, Tim; Nederveen, Joshua P; McKay, Bryon R; Joanisse, Sophie; Verdijk, Lex B; van Loon, Luc J C; Parise, Gianni

    2015-01-01

    Skeletal muscle satellite cells are considered to play a crucial role in muscle fiber maintenance, repair and remodeling. Our knowledge of the role of satellite cells in muscle fiber adaptation has traditionally relied on in vitro cell and in vivo animal models. Over the past decade, a genuine effort has been made to translate these results to humans under physiological conditions. Findings from in vivo human studies suggest that satellite cells play a key role in skeletal muscle fiber repair/remodeling in response to exercise. Mounting evidence indicates that aging has a profound impact on the regulation of satellite cells in human skeletal muscle. Yet, the precise role of satellite cells in the development of muscle fiber atrophy with age remains unresolved. This review seeks to integrate recent results from in vivo human studies on satellite cell function in muscle fiber repair/remodeling in the wider context of satellite cell biology whose literature is largely based on animal and cell models.

  12. What is a Human Body?

    DEFF Research Database (Denmark)

    Nissen, Ulrik Becker

    2016-01-01

    The essay offers an overview of different understandings of what a body is. As such, it can be read as an overview of what we mean, when we speak of a “human body”. However, the article also goes a step further; in the last section, a responsive understanding of the human body is outlined....... This is understood as responsiveness in three ways: viz an embodied self that responds to natural life, other human beings and, ultimately, to God....

  13. A REVIEW ON LOWER APPENDICULAR MUSCULOSKELETAL SYSTEM OF HUMAN BODY

    Directory of Open Access Journals (Sweden)

    M. Akhtaruzzaman

    2016-04-01

    Full Text Available Rehabilitation engineering plays an important role in designing various autonomous robots to provide better therapeutic exercise to disabled patients. Hence it is necessary to study human musculoskeletal system and also needs to be presented in scientific manner in order to describe and analyze the biomechanics of human body motion. This review focuses on lower appendicular musculoskeletal structure of human body to represent joints and links architectures; to identify muscle attachments and functions; and to illustrate muscle groups which are responsible for a particular joint movement. Firstly, human lower skeletal structure, linking systems, joint mechanisms, and their functions are described with a conceptual representation of joint architecture of human skeleton. This section also represents joints and limbs by comparing with mechanical systems. Characteristics of ligaments and their functions to construct skeletal joints are also discussed briefly in this part. Secondly, the study focuses on muscular system of human lower limbs where muscle structure, functions, roles in moving endoskeleton structure, and supporting mechanisms are presented ellaborately. Thirdly, muscle groups are tabulated based on functions that provide mobility to different joints of lower limbs. Finally, for a particular movement action of lower extremity, muscles are also grouped and tabulated to have a better understanding on functions of individual muscle. Basically the study presents an overview of the structure of human lower limbs by characterizing and classifying skeletal and muscular systems.KEYWORDS:   Musculoskeletal system; Human lower limbs; Muscle groups; Joint motion; Biomechatronics; Rehabilitation.

  14. Analysis and Modelling of Muscles Motion during Whole Body Vibration

    Directory of Open Access Journals (Sweden)

    La Gatta A

    2010-01-01

    Full Text Available The aim of the study is to characterize the local muscles motion in individuals undergoing whole body mechanical stimulation. In this study we aim also to evaluate how subject positioning modifies vibration dumping, altering local mechanical stimulus. Vibrations were delivered to subjects by the use of a vibrating platform, while stimulation frequency was increased linearly from 15 to 60 Hz. Two different subject postures were here analysed. Platform and muscles motion were monitored using tiny MEMS accelerometers; a contra lateral analysis was also presented. Muscle motion analysis revealed typical displacement trajectories: motion components were found not to be purely sinusoidal neither in phase to each other. Results also revealed a mechanical resonant-like behaviour at some muscles, similar to a second-order system response. Resonance frequencies and dumping factors depended on subject and his positioning. Proper mechanical stimulation can maximize muscle spindle solicitation, which may produce a more effective muscle activation.

  15. Hyper-elastic properties of the human sternocleidomastoideus muscle in tension

    OpenAIRE

    Gras, Laure-Lise; MITTON, David; VIOT, Philippe; Laporte, Sébastien

    2012-01-01

    Numerical models of the human body require realistic mechanical properties of the muscles as input, but, generally, such data are available only for animals’ muscles. As a consequence, the aim of this study was to identify the hyper-elastic behavior of the human sternocleidomastoideus muscle in tension using different constitutive laws. Ten sternocleidomastoideus muscles were tested in vitro. The hyper-elastic behavior was modeled with an exponential law and a hyper-elastic constitutive...

  16. Muscle fibre type composition and body composition in hammer throwers.

    Science.gov (United States)

    Terzis, Gerasimos; Spengos, Konstantinos; Kavouras, Stavros; Manta, Panagiota; Georgiadis, Giorgos

    2010-01-01

    Aim of the present study was to describe the muscle fibre type composition and body composition of well-trained hammer throwers. Six experienced hammer throwers underwent the following measurements: one repetition maximum in squat, snatch, and clean, standing broad jump, backward overhead shot throw and the hammer throw. Dual x-ray absorptiometry was used for body composition analysis. Fibre type composition and cross sectional area was determined in muscle biopsy samples of the right vastus lateralis. Eight physical education students served as a control group. One repetition maximum in squat, snatch and clean for the hammer throwers was 245 ± 21, 132 ± 13 and 165 ± 12kg, respectively. Lean body mass was higher in hammer throwers (85.9 ± 3. 9kg vs. 62.7 ± 5.1kg (p < 0.01). The percentage area of type II muscle fibres was 66.1 ± 4% in hammer throwers and 51 ± 8% in the control group (p < 0.05). Hammer throwers had significantly larger type IIA fibres (7703 ± 1171 vs. 5676 ± 1270μm(2), p < 0.01). Hammer throwing performance correlated significantly with lean body mass (r = 0.81, p < 0.05). These data indicate that hammer throwers have larger lean body mass and larger muscular areas occupied by type II fibres, compared with relatively untrained subjects. Moreover, it seems that the enlarged muscle mass of the hammer throwers contributes significantly to the hammer throwing performance. Key pointsWell-trained hammer throwers had increased lean body mass, higher type IIA muscle fibres cross sectional areas, as well as higher bone mineral density, compared to controls.Increased lean body mass was closely related with hammer throwing performance.The relative high percentage of type IIX muscle fibres in vastus lateralis in hammer throwers warrants further investigation.

  17. Whole-Body Reaching Movements Formulated by Minimum Muscle-Tension Change Criterion.

    Science.gov (United States)

    Kudo, Naoki; Choi, Kyuheong; Kagawa, Takahiro; Uno, Yoji

    2016-05-01

    It is well known that planar reaching movements of the human shoulder and elbow joints have invariant features: roughly straight hand paths and bell-shaped velocity profiles. The optimal control models with the criteria of smoothness or precision, which determine a unique movement pattern, predict such features of hand trajectories. In this letter on expanding the research on simple arm reaching movements, we examine whether the smoothness criteria can be applied to whole-body reaching movements with many degrees of freedom. Determining a suitable joint trajectory in the whole-body reaching movement corresponds to the optimization problem with constraints, since body balance must be maintained during a motion task. First, we measured human joint trajectories and ground reaction forces during whole-body reaching movements, and confirmed that subjects formed similar movements with common characteristics in the trajectories of the hand position and body center of mass. Second, we calculated the optimal trajectories according to the criteria of torque and muscle-tension smoothness. While the minimum torque change trajectories were not consistent with the experimental data, the minimum muscle-tension change model was able to predict the stereotyped features of the measured trajectories. To explore the dominant effects of the extension from the torque change to the muscle-tension change, we introduced a weighted torque change cost function. Considering the maximum voluntary contraction (MVC) force of the muscle as the weighting factor of each joint torque, we formulated the weighted torque change cost as a simplified version of the minimum muscle-tension change cost. The trajectories owing to the minimum weighted torque change criterion also showed qualitative agreement with the common features of the measured data. Proper estimation of the MVC forces in the body joints is essential to reproduce human whole-body movements according to the minimum muscle-tension change

  18. Human skeletal muscle releases leptin in vivo

    DEFF Research Database (Denmark)

    Wolsk, Emil; Grøndahl, Thomas Sahl; Pedersen, Bente Klarlund

    2012-01-01

    and adipose tissue leptin release in vivo. We recruited 16 healthy male human participants. Catheters were inserted into the femoral artery and vein draining skeletal muscle, as well as an epigastric vein draining the abdominal subcutaneous adipose tissue. By combining the veno-arterial differences in plasma......Leptin is considered an adipokine, however, cultured myocytes have also been found to release leptin. Therefore, as proof-of-concept we investigated if human skeletal muscle synthesized leptin by measuring leptin in skeletal muscle biopsies. Following this, we quantified human skeletal muscle...... leptin with measurements of blood flow, leptin release from both tissues was quantified. To induce changes in leptin, the participants were infused with either saline or adrenaline in normo-physiological concentrations. The presence of leptin in skeletal muscle was confirmed by western blotting. Leptin...

  19. Lactate oxidation in human skeletal muscle mitochondria

    DEFF Research Database (Denmark)

    Jacobs, Robert A; Meinild, Anne-Kristine; Nordsborg, Nikolai B

    2013-01-01

    Lactate is an important intermediate metabolite in human bioenergetics and is oxidized in many different tissues including the heart, brain, kidney, adipose tissue, liver, and skeletal muscle. The mechanism(s) explaining the metabolism of lactate in these tissues, however, remains unclear. Here, we...... analyze the ability of skeletal muscle to respire lactate by using an in situ mitochondrial preparation that leaves the native tubular reticulum and subcellular interactions of the organelle unaltered. Skeletal muscle biopsies were obtained from vastus lateralis muscle in 16 human subjects. Samples were...... of exogenous LDH failed to increase lactate-stimulated respiration (P = 1.0). The results further demonstrate that human skeletal muscle mitochondria cannot directly oxidize lactate within the mitochondrial matrix. Alternately, these data support previous claims that lactate is converted to pyruvate within...

  20. MUSCLE FIBRE TYPE COMPOSITION AND BODY COMPOSITION IN HAMMER THROWERS

    Directory of Open Access Journals (Sweden)

    Gerasimos Terzis

    2010-03-01

    Full Text Available Aim of the present study was to describe the muscle fibre type composition and body composition of well-trained hammer throwers. Six experienced hammer throwers underwent the following measurements: one repetition maximum in squat, snatch, and clean, standing broad jump, backward overhead shot throw and the hammer throw. Dual x-ray absorptiometry was used for body composition analysis. Fibre type composition and cross sectional area was determined in muscle biopsy samples of the right vastus lateralis. Eight physical education students served as a control group. One repetition maximum in squat, snatch and clean for the hammer throwers was 245 ± 21, 132 ± 13 and 165 ± 12kg, respectively. Lean body mass was higher in hammer throwers (85.9 ± 3. 9kg vs. 62.7 ± 5.1kg (p < 0.01. The percentage area of type II muscle fibres was 66.1 ± 4% in hammer throwers and 51 ± 8% in the control group (p < 0.05. Hammer throwers had significantly larger type IIA fibres (7703 ± 1171 vs. 5676 ± 1270μm2, p < 0.01. Hammer throwing performance correlated significantly with lean body mass (r = 0.81, p < 0.05. These data indicate that hammer throwers have larger lean body mass and larger muscular areas occupied by type II fibres, compared with relatively untrained subjects. Moreover, it seems that the enlarged muscle mass of the hammer throwers contributes significantly to the hammer throwing performance

  1. Variability in human body size

    Science.gov (United States)

    Annis, J. F.

    1978-01-01

    The range of variability found among homogeneous groups is described and illustrated. Those trends that show significantly marked differences between sexes and among a number of racial/ethnic groups are also presented. Causes of human-body size variability discussed include genetic endowment, aging, nutrition, protective garments, and occupation. The information is presented to aid design engineers of space flight hardware and equipment.

  2. Effects of whole-body vibration after eccentric exercise on muscle soreness and muscle strength recovery.

    Science.gov (United States)

    Timon, Rafael; Tejero, Javier; Brazo-Sayavera, Javier; Crespo, Carmen; Olcina, Guillermo

    2016-06-01

    [Purpose] The aim of this study was to investigate whether or not a single whole-body vibration treatment after eccentric exercise can reduce muscle soreness and enhance muscle recovery. [Subjects and Methods] Twenty untrained participants were randomly assigned to two groups: a vibration group (n=10) and control group (n=10). Participants performed eccentric quadriceps training of 4 sets of 5 repetitions at 120% 1RM, with 4 min rest between sets. After that, the vibration group received 3 sets of 1 min whole body vibration (12 Hz, 4 mm) with 30 s of passive recovery between sets. Serum creatine kinase, blood urea nitrogen, muscle soreness (visual analog scale) and muscle strength (peak isometric torque) were assessed. [Results] Creatine kinase was lower in the vibration group than in the control group at 24 h (200.2 ± 8.2 vs. 300.5 ± 26.1 U/L) and at 48 h (175.2 ± 12.5 vs. 285.2 ± 19.7 U/L) post-exercise. Muscle soreness decreased in vibration group compared to control group at 48 h post-exercise (34.1 ± 11.4 vs. 65.2 ± 13.2 mm). [Conclusion] Single whole-body vibration treatment after eccentric exercise reduced delayed onset muscle soreness but it did not affect muscle strength recovery.

  3. Deletion of muscle GRP94 impairs both muscle and body growth by inhibiting local IGF production.

    Science.gov (United States)

    Barton, Elisabeth R; Park, SooHyun; James, Jose K; Makarewich, Catherine A; Philippou, Anastassios; Eletto, Davide; Lei, Hanqin; Brisson, Becky; Ostrovsky, Olga; Li, Zihai; Argon, Yair

    2012-09-01

    Insulin-like growth factors (IGFs) are critical for development and growth of skeletal muscles, but because several tissues produce IGFs, it is not clear which source is necessary or sufficient for muscle growth. Because it is critical for production of both IGF-I and IGF-II, we ablated glucose-regulated protein 94 (GRP94) in murine striated muscle to test the necessity of local IGFs for normal muscle growth. These mice exhibited smaller skeletal muscles with diminished IGF contents but with normal contractile function and no apparent endoplasmic reticulum stress response. This result shows that muscles rely on GRP94 primarily to support local production of IGFs, a pool that is necessary for normal muscle growth. In addition, body weights were ∼30% smaller than those of littermate controls, and circulating IGF-I also decreased significantly, yet glucose homeostasis was maintained with little disruption to the growth hormone pathway. The growth defect was complemented on administration of recombinant IGF-I. Thus, unlike liver production of IGF-I, muscle IGF-I is necessary not only locally but also globally for whole-body growth.

  4. [Wireless human body communication technology].

    Science.gov (United States)

    Sun, Lei; Zhang, Xiaojuan

    2014-12-01

    The Wireless Body Area Network (WBAN) is a key part of the wearable monitoring technologies, which has many communication technologies to choose from, like Bluetooth, ZigBee, Ultra Wideband, and Wireless Human Body Communication (WHBC). As for the WHBC developed in recent years, it is worthy to be further studied. The WHBC has a strong momentum of growth and a natural advantage in the formation of WBAN. In this paper, we first briefly describe the technical background of WHBC, then introduce theoretical model of human-channel communication and digital transmission machine based on human channel. And finally we analyze various of the interference of the WHBC and show the AFH (Adaptive Frequency Hopping) technology which can effectively deal with the interference.

  5. Muscle contributions to center of mass excursion in ankle and hip strategies during forward body tilting.

    Science.gov (United States)

    Ogaya, Shinya; Okita, Yusuke; Fuchioka, Satoshi

    2016-10-03

    Humans employ two distinct strategies to maintain balance during standing: the ankle and hip strategies. People with a high fall risk tend to alter their motion patterns during forward body tilting from a hip to an ankle strategy. Improved knowledge regarding how muscles control the center of mass (COM) during balancing would facilitate clinical assessment. The present study aimed to investigate individual muscle contributions to COM motion during forward body tilting with both ankle and hip strategies in 16 healthy adults. While standing, participants were instructed to oscillate their bodies and touch anterior and posterior targets at 0.5Hz. The anterior target was positioned at the sternum height level in a HIGH and 5% lower in a LOW condition to induce ankle and hip strategies, respectively. The muscle tension force was calculated from measured angle data using a two-dimensional, muscle-driven forward simulation model. Muscle contributions to COM acceleration during forward body tilting were calculated via induced acceleration analysis. Long hamstrings were found to increase upward-contributing action and forward COM acceleration in the LOW condition during forward tilting. In contrast, the contribution of the soleus to backward COM acceleration was reduced. These results imply that the contribution of hamstrings to forward COM acceleration is disadvantageous to fore-aft COM control and balance recovery during forward body tilting.

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

    African Journals Online (AJOL)

    Noha Abdel Kader Abdel Kader Hasan

    2016-02-01

    Feb 1, 2016 ... time to fatigue to evaluate endurance time. ... a positive correlation between muscle strength and body mass index ... Isokinetic dynamometry, hand-held dynamometry, field tests, .... dominant side of each child was selected and attached. ... toward elbow flexion (since the elbow flexors were not measured.

  7. Human Muscle Fatigue Model in Dynamic Motions

    CERN Document Server

    Ma, Ruina; Bennis, Fouad; Ma, Liang

    2012-01-01

    Human muscle fatigue is considered to be one of the main reasons for Musculoskeletal Disorder (MSD). Recent models have been introduced to define muscle fatigue for static postures. However, the main drawbacks of these models are that the dynamic effect of the human and the external load are not taken into account. In this paper, each human joint is assumed to be controlled by two muscle groups to generate motions such as push/pull. The joint torques are computed using Lagrange's formulation to evaluate the dynamic factors of the muscle fatigue model. An experiment is defined to validate this assumption and the result for one person confirms its feasibility. The evaluation of this model can predict the fatigue and MSD risk in industry production quickly.

  8. Measurement of foot intrinsic muscle morphology and its relationship with human body static balance stability%足部内在肌形态的测量和与人体静态平衡稳定性的关系

    Institute of Scientific and Technical Information of China (English)

    许正勇; 张先熠

    2016-01-01

    为探究采用超声波技术测量足部内在肌形态的可重复性,并通过对足部内在肌形态与闭眼单腿站立时间的相关性分析探讨足部内在肌对维持人体稳定性的影响。对15名健康青年受试者采用B型超声波技术重复测量趾短屈肌、拇短屈肌、拇展肌及小趾展肌等4个足部内在肌的纵向图像以及横截面图像,用ImageJ图像处理软件测量肌肉厚度及横截面积,用SPSS数据处理软件对两次测量数据进行组内相关系数(ICC)分析,以检测该测试方式的可重复性;同时还测量了闭眼单腿站立时间用以评价平衡稳定性,并对其与4个足部内在肌的形态进行Pearson相关系数分析,探讨内在肌形态对静态平衡能力的影响。结果发现:采用超声波技术对足部内在肌厚度与横截面积的两次测量值的ICC值大部分大于0.9,表明该测试方法的可重复性良好;拇展肌厚度、趾短屈肌及小趾展肌的横截面积与闭眼单腿站立时间成显著性相关,而拇展肌横截面积与其成非常显著相关;足部内在肌横截面积越大,闭眼单腿站立时间越久。结果说明:采用B型超声波技术测量足部内在肌形态的可靠性良好;足部内在肌的形态会影响人体静态平衡控制,对足部核心区稳定性的作用不可忽视。%In order to probe into the repeatability of measuring foot intrinsic muscle morphology by using ultrasonic technology, and to study the effects of foot intrinsic muscles on maintaining human body stability by analyzing the correlation between foot intrinsic muscle morphology and eyes closed single leg standing time, the authors repeat-edly measured the longitudinal and cross-sectional images of such 4 foot intrinsic muscles as flexor digitorum bre-vis, flexor hallucis brevis, abductor hallucis and abductor digiti minimi of 15 healthy young testees by using type B ultrasonic technology, measured muscle thicknesses

  9. Effects of real and sham whole-body mechanical vibration on spinal excitability at rest and during muscle contraction

    NARCIS (Netherlands)

    Hortobagyi, T.; Rider, P.; DeVita, P.

    2014-01-01

    We examined the effects of whole-body mechanical vibration (WBV) on indices of motoneuronal excitability at rest and during muscle contraction in healthy humans. Real and sham WBV at 30Hz had no effect on reflexes measured during muscle contraction. Real WBV at 30 and 50Hz depressed the H-reflex app

  10. Muscle contributions to whole-body sagittal plane angular momentum during walking.

    Science.gov (United States)

    Neptune, R R; McGowan, C P

    2011-01-01

    Walking is a complex dynamic task that requires the regulation of whole-body angular momentum to maintain dynamic balance while performing walking subtasks such as propelling the body forward and accelerating the leg into swing. In human walking, the primary mechanism to regulate angular momentum is muscle force generation. Muscles accelerate body segments and generate ground reaction forces that alter angular momentum about the body's center-of-mass to restore and maintain dynamic stability. In addition, gravity contributes to whole-body angular momentum through its contribution to the ground reaction forces. The purpose of this study was to generate a muscle-actuated forward dynamics simulation of normal walking to quantify how individual muscles and gravity contribute to whole-body angular momentum in the sagittal plane. In early stance, the uniarticular hip and knee extensors (GMAX and VAS), biarticular hamstrings (HAM) and ankle dorsiflexors (TA) generated backward angular momentum while the ankle plantar flexors (SOL and GAS) generated forward momentum. In late stance, SOL and GAS were the primary contributors and generated angular momentum in opposite directions. SOL generated primarily forward angular momentum while GAS generated backward angular momentum. The difference between muscles was due to their relative contributions to the horizontal and vertical ground reaction forces. Gravity contributed to the body's angular momentum in early stance and to a lesser extent in late stance, which was counteracted primarily by the plantar flexors. These results may provide insight into balance and movement disorders and provide a basis for developing locomotor therapies that target specific muscle groups.

  11. Skeletal muscle

    Science.gov (United States)

    There are approximately 650-850 muscles in the human body these include skeletal (striated), smooth and cardiac muscle. The approximation is based on what some anatomists consider separate muscle or muscle systems. Muscles are classified based on their anatomy (striated vs. smooth) and if they are v...

  12. Nutrition and muscle loss in humans during spaceflight

    Science.gov (United States)

    Stein, T. P.

    1999-01-01

    The protein loss in humans during spaceflight is partly due to a normal adaptive response to a decreased work load on the muscles involved in weight bearing. The process is mediated by changes in prostaglandin release, secondary to the decrease in tension on the affected muscles. On missions, where there is a high level of physical demands on the astronauts, there tends to be an energy deficit, which adds to the muscle protein loss and depletes the body fat reserves. While the adaptive response is a normal part of homeostasis, the additional protein loss from an energy deficit can, in the long run, have a negative effect on health and capability of humans to live and work in space and afterward return to Earth.

  13. Multi-frequency bioimpedance in human muscle assessment

    DEFF Research Database (Denmark)

    Bartels, Else Marie; Sørensen, Emma Rudbæk; Harrison, Adrian Paul

    2015-01-01

    Bioimpedance analysis (BIA) is a well-known and tested method for body mass and muscular health assessment. Multi-frequency BIA (mfBIA) equipment now makes it possible to assess a particular muscle as a whole, as well as looking at a muscle at the fiber level. The aim of this study was to test...... healthy human control subjects and three selected cases were examined to demonstrate the extent to which this method may be used clinically, and in relation to training in sport. The electrode setup is shown to affect the mfBIA parameters recorded. Our recommendation is the use of noble metal electrodes...

  14. GLUT-3 expression in human skeletal muscle

    Science.gov (United States)

    Stuart, C. A.; Wen, G.; Peng, B. H.; Popov, V. L.; Hudnall, S. D.; Campbell, G. A.

    2000-01-01

    Muscle biopsy homogenates contain GLUT-3 mRNA and protein. Before these studies, it was unclear where GLUT-3 was located in muscle tissue. In situ hybridization using a midmolecule probe demonstrated GLUT-3 within all muscle fibers. Fluorescent-tagged antibody reacting with affinity-purified antibody directed at the carboxy-terminus demonstrated GLUT-3 protein in all fibers. Slow-twitch muscle fibers, identified by NADH-tetrazolium reductase staining, possessed more GLUT-3 protein than fast-twitch fibers. Electron microscopy using affinity-purified primary antibody and gold particle-tagged second antibody showed that the majority of GLUT-3 was in association with triads and transverse tubules inside the fiber. Strong GLUT-3 signals were seen in association with the few nerves that traversed muscle sections. Electron microscopic evaluation of human peripheral nerve demonstrated GLUT-3 within the axon, with many of the particles related to mitochondria. GLUT-3 protein was found in myelin but not in Schwann cells. GLUT-1 protein was not present in nerve cells, axons, myelin, or Schwann cells but was seen at the surface of the peripheral nerve in the perineurium. These studies demonstrated that GLUT-3 mRNA and protein are expressed throughout normal human skeletal muscle, but the protein is predominantly found in the triads of slow-twitch muscle fibers.

  15. A 3-Dimensional Atlas of Human Tongue Muscles

    Science.gov (United States)

    SANDERS, IRA; MU, LIANCAI

    2013-01-01

    The human tongue is one of the most important yet least understood structures of the body. One reason for the relative lack of research on the human tongue is its complex anatomy. This is a real barrier to investigators as there are few anatomical resources in the literature that show this complex anatomy clearly. As a result, the diagnosis and treatment of tongue disorders lags behind that for other structures of the head and neck. This report intended to fill this gap by displaying the tongue’s anatomy in multiple ways. The primary material used in this study was serial axial images of the male and female human tongue from the Visible Human (VH) Project of the National Library of Medicine. In addition, thick serial coronal sections of three human tongues were rendered translucent. The VH axial images were computer reconstructed into serial coronal sections and each tongue muscle was outlined. These outlines were used to construct a 3-dimensional computer model of the tongue that allows each muscle to be seen in its in vivo anatomical position. The thick coronal sections supplement the 3-D model by showing details of the complex interweaving of tongue muscles throughout the tongue. The graphics are perhaps the clearest guide to date to aid clinical or basic science investigators in identifying each tongue muscle in any part of the human tongue. PMID:23650264

  16. A three-dimensional atlas of human tongue muscles.

    Science.gov (United States)

    Sanders, Ira; Mu, Liancai

    2013-07-01

    The human tongue is one of the most important yet least understood structures of the body. One reason for the relative lack of research on the human tongue is its complex anatomy. This is a real barrier to investigators as there are few anatomical resources in the literature that show this complex anatomy clearly. As a result, the diagnosis and treatment of tongue disorders lags behind that for other structures of the head and neck. This report intended to fill this gap by displaying the tongue's anatomy in multiple ways. The primary material used in this study was serial axial images of the male and female human tongue from the Visible Human (VH) Project of the National Library of Medicine. In addition, thick serial coronal sections of three human tongues were rendered translucent. The VH axial images were computer reconstructed into serial coronal sections and each tongue muscle was outlined. These outlines were used to construct a three-dimensional (3D) computer model of the tongue that allows each muscle to be seen in its in vivo anatomical position. The thick coronal sections supplement the 3D model by showing details of the complex interweaving of tongue muscles throughout the tongue. The graphics are perhaps the clearest guide to date to aid clinical or basic science investigators in identifying each tongue muscle in any part of the human tongue.

  17. Robotic Powered Transfer Mechanism modeling on Human Muscle Structure

    Science.gov (United States)

    Saito, Yukio

    It is considered in engineering that one power source can operate one joint. However, support movement mechanism of living organism is multi joint movement mechanism. Considerably different from mechanical movement mechanism, two pairs of uni-articular muscles and a pair of bi-articular muscles are involved in it. In leg, movements observed in short run including leg idling, heel contact and toeing are operated by bi-articular muscles of the thigh showing strong legs to support body weight. Pursuit of versatility in welfare robot brings its comparison with conventional machinery or industrial robot to the fore. Request for safety and technology allowing elderly people to operate the robot is getting stronger in the society. The robot must be safe when it is used together with other welfare equipment and simpler system avoiding difficult operation has to be constructed. Appearance of recent care and assistance robot is getting similar to human arm in comparison with industrial robot. Being easily able to imagine from industrial robot, mid-heavyweight articulated robot to support 60-70kgf combined with large output motor and reduction gears is next to impossible to be installed in the bath room. This research indicated that upper limb arm and lower limb thigh of human and animals are holding coalitional muscles and movement of uni-artcular muscle and bi-articular muscle conjure the image of new actuators.

  18. Analysis of Muscle Activity Utilizing Bench Presses in the AnyBody Simulation Modelling System

    Directory of Open Access Journals (Sweden)

    Zhongqiu Ji

    2016-01-01

    Full Text Available Using the AnyBody human modeling system with identical weights and varying grip distance (40.0 cm, 50.0 cm, and 60.0 cm, the stress distribution for the pectoralis and the muscle of upper extremity during a bench press was simulated, and the surface myoelectricity (EMG method was validated. Methods. The physical parameters driving the model of the human body were selected as weights of 35.0% (25.0 kg and grip distances. Conclusion. The validation of AnyBody software was proved as a high validity by using EMG test of four muscles’ activity compared to AnyBody software. During a bench press, the pectoralis major is the main muscle, the pectoralis major discharge increases with the height of barbell increases, and the pectoralis major discharge decreases as the short grip width increases. When the grip width equals the shoulder width, the value of pectoralis minor is lowest; when the grip width is smaller or larger than the shoulder width, the value is larger. As the short grip distance increases, the discharge of posterior deltoid muscle and triceps surface myoelectricity increases; thus, as the short grip distance increases, the deltoid muscle and triceps assist the pectoralis major during a bench press.

  19. Muscle Carnosine Is Associated with Cardiometabolic Risk Factors in Humans.

    Directory of Open Access Journals (Sweden)

    Barbora de Courten

    Full Text Available Carnosine is a naturally present dipeptide abundant in skeletal muscle and an over-the counter food additive. Animal data suggest a role of carnosine supplementation in the prevention and treatment of obesity, insulin resistance, type 2 diabetes and cardiovascular disease but only limited human data exists.Samples of vastus lateralis muscle were obtained by needle biopsy. We measured muscle carnosine levels (high-performance liquid chromatography, % body fat (bioimpedance, abdominal subcutaneous and visceral adiposity (magnetic resonance imaging, insulin sensitivity (euglycaemic hyperinsulinemic clamp, resting energy expenditure (REE, indirect calorimetry, free-living ambulatory physical activity (accelerometers and lipid profile in 36 sedentary non-vegetarian middle aged men (45±7 years with varying degrees of adiposity and glucose tolerance. Muscle carnosine content was positively related to % body fat (r = 0.35, p = 0.04 and subcutaneous (r = 0.38, p = 0.02 but not visceral fat (r = 0.17, p = 0.33. Muscle carnosine content was inversely associated with insulin sensitivity (r = -0.44, p = 0.008, REE (r = -0.58, p<0.001 and HDL-cholesterol levels (r = -0.34, p = 0.048. Insulin sensitivity and physical activity were the best predictors of muscle carnosine content after adjustment for adiposity.Our data shows that higher carnosine content in human skeletal muscle is positively associated with insulin resistance and fasting metabolic preference for glucose. Moreover, it is negatively associated with HDL-cholesterol and basal energy expenditure. Intervention studies targeting insulin resistance, metabolic and cardiovascular disease risk factors are necessary to evaluate its putative role in the prevention and management of type 2 diabetes and cardiovascular disease.

  20. Noninvasive analysis of human neck muscle function

    Science.gov (United States)

    Conley, M. S.; Meyer, R. A.; Bloomberg, J. J.; Feeback, D. L.; Dudley, G. A.

    1995-01-01

    selected muscles that have been examined in human electromyographic studies. Neck muscle function and morphology can be studied at a detailed level using exercise-induced shifts in magnetic resonance images.

  1. Muscle sonography in six patients with hereditary inclusion body myopathy

    Energy Technology Data Exchange (ETDEWEB)

    Adler, Ronald S. [Weill Medical College of Cornell University, Division of Ultrasound and Body Imaging, Hospital for Special Surgery, New York, NY (United States); Garolfalo, Giovanna [Ospedale Residenza Sanitaria Riabilitativa, Fermo, AP (Italy); Paget, Stephen; Kagen, Lawrence [Weill Medical College of Cornell University, Rheumatology Division, Hospital for Special Surgery, New York, NY (United States)

    2008-01-15

    To evaluate the morphological changes of muscle with sonography in six patients affected by hereditary inclusion body myopathy (HIBM). We studied a group of six Persian Jews diagnosed with HIBM. All were homozygous for the GNE mutation M712T. Ultrasonographic examinations of the quadriceps femoris and hamstring muscle groups were performed. A follow-up ultrasound examination was performed, after an interval of 3 years, in four of these patients. Muscles were assessed subjectively as to echogenicity, determined by gray-scale assessment, and loss of normal muscle morphology. Power Doppler sonography (PDS) was used to assess vascularity. A sonographic finding of central atrophy and peripheral sparing resulting in a target-like appearance was noted in the hamstring compartment of all six patients. The quadriceps compartment also showed involvement of the rectus femoris of all patients, which, in some cases, was the only muscle involved in the quadriceps. Vascularity was markedly reduced in the affected areas, with blood flow demonstrated in the peripherally spared areas. The severity of atrophy increased with disease duration. In this case series, we describe a new sonographic finding as well as document progression of HIBM disease, which has generally been described as quadriceps sparing. The myopathic target lesion, as well as isolated rectus femoris atrophy, may provide a useful adjunct to disease diagnosis. (orig.)

  2. Anisotropic photon migration in human skeletal muscle

    Energy Technology Data Exchange (ETDEWEB)

    Binzoni, T [Departement de Neurosciences Fondamentales, University of Geneva (Switzerland); Department of Radiology, University Hospital, Geneva (Switzerland); Courvoisier, C [Departement d' optique PM Duffieux, Institut FEMTO-ST, UMR CNRS 6174, Universite de Franche Comte, Besancon (France); Giust, R [Departement d' optique PM Duffieux, Institut FEMTO-ST, UMR CNRS 6174, Universite de Franche Comte, Besancon (France); Tribillon, G [Departement d' optique PM Duffieux, Institut FEMTO-ST, UMR CNRS 6174, Universite de Franche Comte, Besancon (France); Gharbi, T [Departement d' optique PM Duffieux, Institut FEMTO-ST, UMR CNRS 6174, Universite de Franche Comte, Besancon (France); Hebden, J C [Department of Medical Physics and Bioengineering, University College London (United Kingdom); Leung, T S [Department of Medical Physics and Bioengineering, University College London (United Kingdom); Roux, J [Hamamatsu Photonics, Grenoble (France); Delpy, D T [Department of Medical Physics and Bioengineering, University College London (United Kingdom)

    2006-03-07

    It is demonstrated in the short head of the human biceps brachii of 16 healthy subjects (12 males and 4 females) that near infrared photon migration is anisotropic. The probability for a photon to travel along the direction of the muscle fibres is higher ({approx}0.4) than that of travelling along a perpendicular axis ({approx}0.3) while in the adipose tissue the probability is the same ({approx}0.33) in all directions. Considering that the muscle fibre orientation is different depending on the type of muscle considered, and that inside a given skeletal muscle the orientation may change, the present findings in part might explain the intrasubject variability observed in the physiological parameters measured by near infrared spectroscopy techniques. In other words, the observed regional differences might not only be physiological differences but also optical artefacts. (note)

  3. Restrictions in systemic and locomotor skeletal muscle perfusion, oxygen supply and VO2 during high-intensity whole-body exercise in humans

    DEFF Research Database (Denmark)

    Mortensen, S.P.; Damsgaard, R.; Dawson, E.A.

    2008-01-01

    supramaximal cycling (498 +/- 16 W; 110% of peak power; mean +/- S.E.M.) in addition to both incremental cycling and knee-extensor exercise to exhaustion in 13 trained males. During supramaximal cycling, cardiac output (Q), leg blood flow (LBF), and systemic and leg O(2) delivery and reached peak values after...... 60-90 s and thereafter levelled off at values similar to or approximately 6% (P cycling, while upper body blood flow remained unchanged (approximately 5.5 l min(-1)). In contrast, Q and LBF increased linearly until exhaustion during one-legged knee-extensor exercise accompanying...... increases in non-locomotor tissue blood flow to approximately 12 l min(-1). At exhaustion during cycling compared to knee-extensor exercise, Q, LBF, leg vascular conductance, leg O(2) delivery and leg for a given power were reduced by 32-47% (P

  4. Muscle pain: animal and human experimental and clinical studies.

    Science.gov (United States)

    Marchettini, P

    1993-10-01

    The search for the identification of the sensory apparatus encoding muscle pain sensation in humans is recounted. Basic neurophysiologic animal studies, leading to a description of slowly conducting afferent from muscle and definition of high threshold polymodal muscle nociceptors, and pioneer psychophysic human studies together with recent microneurographic experiments in humans are described. The phenomena of muscle pain broad localization and distant referral are discussed, and clinical implications are extrapolated to interpret muscle pain as a localizing sign of mononeuropathy or radiculopathy. The identification of human muscle nociceptors has defined the scientific standard to test emerging clinical descriptions having muscle pain as a symptom.

  5. Skeletal muscle responses to unweighting in humans

    Science.gov (United States)

    Dudley, Gary A.

    1991-01-01

    An overview of earth-based studies is presented emphasizing the data on muscular strength and size derived from experiments under simulated microgravity. The studies involve the elimination of weight-bearing responsibility of lower-limb human musculature to simulate the unweighting effects of space travel in the absence of exercise. Reference is given to bedrest and unilateral lower-limb suspension, both of which provide data that demonstrate the decreased strength of the knee extensors of 20-25 percent. The response is related to the decrease in cross-sectional area of the knee extensors which is a direct indication of muscle-fiber atrophy. Most of the effects of unweighting are associated with extensor muscles in the lower limbs and not with postural muscles. Unweighting is concluded to cause significant adaptations in the human neuromuscular system that require further investigation.

  6. MuscleBuilder:A Modeling Tool for Human Anatomy

    Institute of Scientific and Technical Information of China (English)

    Amaury Aubel; Daniel Thalmann

    2004-01-01

    A traditional multi-layered approach is adopted to human body modeling and deformation. The model is split into three general anatomical structures: the skeleton, musculature and skin. It is shown that each of these layers is modeled and deformed by using fast, procedural, ad-hoc methods that can painlessly be reimplemented. The modeling approach is generic enough to handle muscles of varying shape, size and characteristics and does not break in extreme skeleton poses. It is also described that the integrated MuscleBuilder system whose main features are: i) easy and quick creation of muscle deformation models; ii) automatic deformation of an overlying skin. It is shown that visually realistic results can be obtained at interactive frame rates with very little input from the designer.

  7. Modeling human muscle disease in zebrafish

    OpenAIRE

    Guyon, Jeffrey R.; Steffen, Leta S; Howell, Melanie H.; Pusack, Timothy J; Lawrence, Chris; Kunkel, Louis M

    2007-01-01

    Modeling human muscle disease in zebrafish correspondence: Corresponding author. Children's Hospital Boston, Enders Bldg, Rm 570, 300 Longwood Ave Boston, MA 02115. Tel.: +1 617 355 7576. (Kunkel, Louis M.) (Kunkel, Louis M.) Program in Genomics and Howard Hughes Medical Institute at Children's Hospital Boston - Boston--> , MA 02115--> - UNITED STATES (Guyon, Jeffrey R.) Program in Genomics a...

  8. Electromyogram premotion silent period and tension development in human muscle.

    Science.gov (United States)

    Kawahats, K; Miyashita, M

    1983-11-01

    The EMG silent period has been observed frequently just before rapid movement from a slightly sustained contraction of the muscle. Our experiments were designed to show the relation between the tension developed in an intact human muscle and the occurrence of this silent period. Tension in the knee extensor was obtained from the floor reaction force of a living subject in a squatting position on the basis of a lever ratio-joint angle diagram obtained directly from measurements on an isolated knee extensor muscle of a human cadaver. The muscle tension was calculated under the condition that the floor reaction force in the squatting position passed through the anklebone, and decreased from 8.7 to 0.8 kN with an increase in the knee joint angle from 1.13 to 2.74 rad. When the center of pressure was not assumed, the increased knee extensor muscle torque with a decrease in the knee angle was estimated biomechanically from the free body diagram. Consistently, the EMG recordings confirmed an increased muscle activity with a reduction in the joint angle. The premotion silent period for the knee extensors and their antagonist with movement from the squatting position appeared to be limited to a knee joint angle of 2.44 to 3.07 rad, where the requirement for tension in those muscles was low. This silent period could be interpreted as an electromyographic transitional phase attributable to a switching mechanism in central nervous activity. The premotion silent period was most likely to appear prior to a swift, well coordinated movement.

  9. Human intersegmental reflexes from intercostal afferents to scalene muscles.

    Science.gov (United States)

    McBain, Rachel A; Taylor, Janet L; Gorman, Robert B; Gandevia, Simon C; Butler, Jane E

    2016-10-01

    What is the central question of this study? The aim was to determine whether specific reflex connections operate between intercostal afferents and the scalene muscles in humans, and whether these connections operate after a clinically complete cervical spinal cord injury. What is the main finding and its importance? This is the first description of a short-latency inhibitory reflex connection between intercostal afferents from intercostal spaces to the scalene muscles in able-bodied participants. We suggest that this reflex is mediated by large-diameter afferents. This intercostal-to-scalene inhibitory reflex is absent after cervical spinal cord injury and may provide a way to monitor the progress of the injury. Short-latency intersegmental reflexes have been described for various respiratory muscles in animals. In humans, however, only short-latency reflex responses to phrenic nerve stimulation have been described. Here, we examined the reflex connections between intercostal afferents and scalene muscles in humans. Surface EMG recordings were made from scalene muscles bilaterally, in seven able-bodied participants and seven participants with motor- and sensory-complete cervical spinal cord injury (median 32 years postinjury, range 5 months to 44 years). We recorded the reflex responses produced by stimulation of the eighth or tenth left intercostal nerve. A short-latency (∼38 ms) inhibitory reflex was evident in able-bodied participants, in ipsilateral and contralateral scalene muscles. This bilateral intersegmental inhibitory reflex occurred in 46% of recordings at low stimulus intensities (at three times motor threshold). It was more frequent (in 75-85% of recordings) at higher stimulus intensities (six and nine times motor threshold), but onset latency (38 ± 9 ms, mean ± SD) and the size of inhibition (23 ± 10%) did not change with stimulus intensity. The reflex was absent in all participants with spinal cord injury. As the intercostal

  10. Plasticity in mitochondrial cristae density allows metabolic capacity modulation in human skeletal muscle

    DEFF Research Database (Denmark)

    Nielsen, Joachim; Gejl, Kasper D; Hey-Mogensen, Martin;

    2016-01-01

    that this mechanism allows evasion of the trade-off between cell occupancy by mitochondria and other cellular constituents and improved metabolic capacity and fuel catabolism during prolonged elevated energy requirements. This article is protected by copyright. All rights reserved.......-body level, muscle mitochondrial cristae density is a better predictor of maximal oxygen uptake rate than muscle mitochondrial volume. Our findings establish elevating mitochondrial cristae density as a regulatory mechanism for increasing metabolic power in human skeletal muscle. We propose...

  11. A microcalorimetric study of the sodium-potassium-pump and thermogenesis in human skeletal muscle.

    Science.gov (United States)

    Fagher, B; Sjögren, A; Monti, M

    1987-11-01

    Thermogenesis in human skeletal muscle was monitored by measurement of heat production using perfusion microcalorimetry. Heat production significantly correlated with relative body weight. The energy expenditure of the Na-K-pump (delta P), assessed after inhibition by ouabain in Krebs-Ringer phosphate buffer containing glucose and insulin, amounted to 6% of the total heat production in vastus lateralis muscle. Muscle potassium positively correlated with delta P (r = 0.84, P less than 0.005). For rectus abdominis muscle delta P was 8-15%; 95% confidence interval for the difference was 3-5% when comparison was made with vastus lateralis. The finding of a positive relationship between delta P and muscle magnesium (r = 0.68, P less than 0.04) is possibly explained by the dependence of ATP hydrolysis on internal magnesium. Our data on resting thermogenesis in small muscle samples agree to previous estimates of O2 consumption in human skeletal muscle in vivo.

  12. Muscle mitochondrial capacity exceeds maximal oxygen delivery in humans

    DEFF Research Database (Denmark)

    Boushel, Robert Christopher; Gnaiger, Erich; Calbet, Jose A L

    2011-01-01

    Across a wide range of species and body mass a close matching exists between maximal conductive oxygen delivery and mitochondrial respiratory rate. In this study we investigated in humans how closely in-vivo maximal oxygen consumption (VO(2) max) is matched to state 3 muscle mitochondrial...... respiration. High resolution respirometry was used to quantify mitochondrial respiration from the biopsies of arm and leg muscles while in-vivo arm and leg VO(2) were determined by the Fick method during leg cycling and arm cranking. We hypothesized that muscle mitochondrial respiratory rate exceeds...... that of systemic oxygen delivery. The state 3 mitochondrial respiration of the deltoid muscle (4.3±0.4 mmol o(2)kg(-1) min(-1)) was similar to the in-vivo VO(2) during maximal arm cranking (4.7±0.5 mmol O(2) kg(-1) min(-1)) with 6 kg muscle. In contrast, the mitochondrial state 3 of the quadriceps was 6.9±0.5 mmol...

  13. Independent Aftereffects of Fat and Muscle: Implications for neural encoding, body space representation, and body image disturbance.

    Science.gov (United States)

    Sturman, Daniel; Stephen, Ian D; Mond, Jonathan; Stevenson, Richard J; Brooks, Kevin R

    2017-01-10

    Although research addressing body size misperception has focused on socio-cognitive processes, such as internalization of the "ideal" images of bodies in the media, the perceptual basis of this phenomenon remains largely unknown. Further, most studies focus on body size per se even though this depends on both fat and muscle mass - variables that have very different relationships with health. We tested visual adaptation as a mechanism for inducing body fat and muscle mass misperception, and assessed whether these two dimensions of body space are processed independently. Observers manipulated the apparent fat and muscle mass of bodies to make them appear "normal" before and after inspecting images from one of four adaptation conditions (increased fat/decreased fat/increased muscle/decreased muscle). Exposure resulted in a shift in the point of subjective normality in the direction of the adapting images along the relevant (fat or muscle) axis, suggesting that the neural mechanisms involved in body fat and muscle perception are independent. This supports the viability of adaptation as a model of real-world body size misperception, and extends its applicability to clinical manifestations of body image disturbance that entail not only preoccupation with thinness (e.g., anorexia nervosa) but also with muscularity (e.g., muscle dysmorphia).

  14. Independent Aftereffects of Fat and Muscle: Implications for neural encoding, body space representation, and body image disturbance

    Science.gov (United States)

    Sturman, Daniel; Stephen, Ian D.; Mond, Jonathan; Stevenson, Richard J; Brooks, Kevin R.

    2017-01-01

    Although research addressing body size misperception has focused on socio-cognitive processes, such as internalization of the “ideal” images of bodies in the media, the perceptual basis of this phenomenon remains largely unknown. Further, most studies focus on body size per se even though this depends on both fat and muscle mass – variables that have very different relationships with health. We tested visual adaptation as a mechanism for inducing body fat and muscle mass misperception, and assessed whether these two dimensions of body space are processed independently. Observers manipulated the apparent fat and muscle mass of bodies to make them appear “normal” before and after inspecting images from one of four adaptation conditions (increased fat/decreased fat/increased muscle/decreased muscle). Exposure resulted in a shift in the point of subjective normality in the direction of the adapting images along the relevant (fat or muscle) axis, suggesting that the neural mechanisms involved in body fat and muscle perception are independent. This supports the viability of adaptation as a model of real-world body size misperception, and extends its applicability to clinical manifestations of body image disturbance that entail not only preoccupation with thinness (e.g., anorexia nervosa) but also with muscularity (e.g., muscle dysmorphia). PMID:28071712

  15. Motor endplate cholinesterase in human skeletal muscle.

    Directory of Open Access Journals (Sweden)

    Fujii,Masafumi

    1982-08-01

    Full Text Available The activity and properties of cholinesterase (ChE of the motor endplate and its fractions were studied in isolated human skeletal muscle. This preparation was used since the ChE activity of the membrane preparation was localized only in the motor endplate. The endplate ChE was stable in the isolated membrane for 4 weeks at 4 degrees C. The specific activity of the extracted ChE of human muscle membrane was 29.6% higher than that of the original membrane. Studies with specific substrates and ChE inhibitors indicated that most of the ChE of human muscle membrane and its fractions was acetylcholinesterase, and that the minor component was pseudocholinesterase. A Michaelis-Menten constant of 3.82 mM was estimated in the endplate ChE, and 0.88 mM in the extracted ChE of the endplate. The extracted human endplate ChE was separated into three fractions by Sephadex G-200 chromatography, and into two fractions by acrylamide gel electrophoresis.

  16. Forward dynamics simulation of human body under tilting perturbations

    Science.gov (United States)

    Naderi, D.; Pasha Zanoosi, A. A.; Sadeghi-Mehr, M.

    2012-02-01

    Human body uses different strategies to maintain its stability and these strategies vary from fixed-foot strategies to strategies which foot is moved in order to increase the support base. Tilting movement of foot is one type of the perturbations usually is exposed to human body. In the presence of such perturbations human body must employ appropriate reactions to prevent threats like falling. But it is not clear that how human body maintains its stability by central nervous system (CNS). At present study it is tried that by presenting a musculoskeletal model of human lower extremity with four links, three degrees of freedom (DOF) and eight skeletal muscles, the level of muscle activations causes the maintenance of stability, be investigated. Using forward dynamics solution, leads to a more general problem, rather than inverse dynamics. Hence, forward dynamics solution by forward optimization has been used for solving this highly nonlinear problem. To this end, first the system's equations of motion has been derived using lagrangian dynamics. Eight Hill-type muscles as actuators of the system were modeled. Because determination of muscle forces considering their number is an undetermined problem, optimization of an appropriate goal function should be practiced. For optimization problem, the characteristics of genetic algorithms as a method based on direct search, and the direct collocation method, has been profited. Also by considering requirements of problem, some constraints such as conservation of model stability are entered into optimization procedure. Finally to investigate validation of model, the results from optimization and experimental data are compared and good agreements are obtained.

  17. BODY PRESSURE DISTRIBUTION OF AUTOMOBILE DRIVING HUMAN MACHINE CONTACT INTERFACE

    Institute of Scientific and Technical Information of China (English)

    CHEN Juan; HONG Jun; ZHANG E; LIANG Jian; LU Bingheng

    2007-01-01

    Aiming at the fatigue and comfort issues of human-machine contact Interface in automobile driving and based on physiological and anatomical principle, the physiological and biochemical process of muscles and nerves in the formation and development of fatigue is analyzed systematically. The fatigue-causing physiological characteristic Indexes are mapped to biomechanical Indexes like muscle stress-strain, the compression deformation of Wood vessels and nerves etc.from the perspective of formation mechanism. The geometrical model of skeleton and parenchyma is established by applying CT-scanned body data and MRI images. The general rule of comfort body pressure distribution is acquired through the analysis of anatomical structure of buttocks and femoral region. The comprehensive lest platform for sitting comfort of 3D adjustable contact Interface is constructed. The lest of body pressure distribution of human-machine contact interface and its comparison with subjective evaluation indicates that the biomechanical Indexes of automobile driving human-machine contact interface and body pressure distribution rule studied can effectively evaluate the fatigue and comfort issues of human-machine contact interface and provide theoretical basis for the optimal design of human-machine contact interface.

  18. A Human Body Analysis System

    Directory of Open Access Journals (Sweden)

    Girondel Vincent

    2006-01-01

    Full Text Available This paper describes a system for human body analysis (segmentation, tracking, face/hands localisation, posture recognition from a single view that is fast and completely automatic. The system first extracts low-level data and uses part of the data for high-level interpretation. It can detect and track several persons even if they merge or are completely occluded by another person from the camera's point of view. For the high-level interpretation step, static posture recognition is performed using a belief theory-based classifier. The belief theory is considered here as a new approach for performing posture recognition and classification using imprecise and/or conflicting data. Four different static postures are considered: standing, sitting, squatting, and lying. The aim of this paper is to give a global view and an evaluation of the performances of the entire system and to describe in detail each of its processing steps, whereas our previous publications focused on a single part of the system. The efficiency and the limits of the system have been highlighted on a database of more than fifty video sequences where a dozen different individuals appear. This system allows real-time processing and aims at monitoring elderly people in video surveillance applications or at the mixing of real and virtual worlds in ambient intelligence systems.

  19. Effects of whole body vibration training on body composition, skeletal muscle strength, and cardiovascular health

    OpenAIRE

    Park, Song-Young; Son, Won-Mok; Kwon, Oh-Sung

    2015-01-01

    Whole body vibration training (WBVT) has been used as a supplement to conventional exercise training such as resistance exercise training to improve skeletal muscle strength, specifically, in rehabilitation field. Recently, this exercise modality has been utilized by cardiovascular studies to examine whether WBVT can be a useful exercise modality to improve cardiovascular health. These studies reported that WBVT has not only beneficial effects on muscular strength but also cardiovascular heal...

  20. Myofibre damage in human skeletal muscle

    DEFF Research Database (Denmark)

    Crameri, R M; Aagaard, P; Qvortrup, K

    2007-01-01

    Disruption to proteins within the myofibre after a single bout of unaccustomed eccentric exercise is hypothesized to induce delayed onset of muscle soreness and to be associated with an activation of satellite cells. This has been shown in animal models using electrical stimulation but not in hum......Disruption to proteins within the myofibre after a single bout of unaccustomed eccentric exercise is hypothesized to induce delayed onset of muscle soreness and to be associated with an activation of satellite cells. This has been shown in animal models using electrical stimulation...... but not in humans using voluntary exercise. Untrained males (n=8, range 22-27 years) performed 210 maximal eccentric contractions with each leg on an isokinetic dynamometer, voluntarily (VOL) with one leg and electrically induced (ES) with the other leg. Assessments from the skeletal muscle were obtained prior...... to exercise and at 5, 24, 96 and 192 h postexercise. Muscle tenderness rose in VOL and ES after 24 h, and did not differ between groups. Maximal isometric contraction strength, rate of force development and impulse declined in the VOL leg from 4 h after exercise, but not in ES (except at 24 h). In contrast...

  1. Whole-body magnetic resonance imaging in skeletal muscle disease.

    Science.gov (United States)

    Shelly, Martin J; Bolster, Ferdia; Foran, Paul; Crosbie, Ian; Kavanagh, Eoin C; Eustace, Stephen J

    2010-03-01

    The evaluation of muscle diseases has traditionally integrated clinical with biochemical findings, occasionally resorting to muscle biopsy. This article reviews the role and imaging appearances of muscle diseases at MRI, specifically emphasising the role of WBMRI in global assessment of muscle abnormality, and in particular its role in determining distribution and extent of muscle abnormality.

  2. Neural correlates of human body perception.

    Science.gov (United States)

    Aleong, Rosanne; Paus, Tomás

    2010-03-01

    The objective of this study was to investigate potential sex differences in the neural response to human bodies using fMRI carried out in healthy young adults. We presented human bodies in a block-design experiment to identify body-responsive regions of the brain, namely, extrastriate body area (EBA) and fusiform body area (FBA). In a separate event-related "adaptation" experiment, carried out in the same group of subjects, we presented sets of four human bodies of varying body size and shape. Varying levels of body morphing were introduced to assess the degree of morphing required for adaptation release. Analysis of BOLD signal in the block-design experiment revealed significant Sex x Hemisphere interactions in the EBA and the FBA responses to human bodies. Only women showed greater BOLD response to bodies in the right hemisphere compared with the left hemisphere for both EBA and FBA. The BOLD response in right EBA was higher in women compared with men. In the adaptation experiment, greater right versus left hemisphere response for EBA and FBA was also identified among women but not men. These findings are particularly novel in that they address potential sex differences in the lateralization of EBA and FBA responses to human body images. Although previous studies have found some degree of right hemisphere dominance in body perception, our results suggest that such a functional lateralization may differ between men and women.

  3. Electric Shock and the Human Body.

    Science.gov (United States)

    Brown, Colin

    1986-01-01

    Discusses electricity's documented effects on the human body, including both the dangers to human health and the medical application of electrical stimulation to heart problems. Discusses the teaching of such physics topics to potential medical students. (TW)

  4. Modeling Forces on the Human Body.

    Science.gov (United States)

    Pagonis, Vasilis; Drake, Russel; Morgan, Michael; Peters, Todd; Riddle, Chris; Rollins, Karen

    1999-01-01

    Presents five models of the human body as a mechanical system which can be used in introductory physics courses: human arms as levers, humans falling from small heights, a model of the human back, collisions during football, and the rotating gymnast. Gives ideas for discussions and activities, including Interactive Physics (TM) simulations. (WRM)

  5. Ultrasonic range measurements on the human body

    NARCIS (Netherlands)

    Weenk, D.; Beijnum, van B.J.F.; Droog, A.; Hermens, H.J.; Veltink, P.H.

    2013-01-01

    Ambulatory range estimation on the human body is important for the assessment of the performance of upper- and lower limb tasks outside a laboratory. In this paper an ultrasound sensor for estimating ranges on the human body is presented and validated during gait. The distance between the feet is e

  6. Ultrasonic range measurements on the human body

    NARCIS (Netherlands)

    Weenk, D.; van Beijnum, Bernhard J.F.; Droog, Adriaan; Hermens, Hermanus J.; Veltink, Petrus H.

    2013-01-01

    Ambulatory range estimation on the human body is important for the assessment of the performance of upper- and lower limb tasks outside a laboratory. In this paper an ultrasound sensor for estimating ranges on the human body is presented and validated during gait. The distance between the feet is

  7. A Circuit Model of Real Time Human Body Hydration.

    Science.gov (United States)

    Asogwa, Clement Ogugua; Teshome, Assefa K; Collins, Stephen F; Lai, Daniel T H

    2016-06-01

    Changes in human body hydration leading to excess fluid losses or overload affects the body fluid's ability to provide the necessary support for healthy living. We propose a time-dependent circuit model of real-time human body hydration, which models the human body tissue as a signal transmission medium. The circuit model predicts the attenuation of a propagating electrical signal. Hydration rates are modeled by a time constant τ, which characterizes the individual specific metabolic function of the body part measured. We define a surrogate human body anthropometric parameter θ by the muscle-fat ratio and comparing it with the body mass index (BMI), we find theoretically, the rate of hydration varying from 1.73 dB/min, for high θ and low τ to 0.05 dB/min for low θ and high τ. We compare these theoretical values with empirical measurements and show that real-time changes in human body hydration can be observed by measuring signal attenuation. We took empirical measurements using a vector network analyzer and obtained different hydration rates for various BMI, ranging from 0.6 dB/min for 22.7 [Formula: see text] down to 0.04 dB/min for 41.2 [Formula: see text]. We conclude that the galvanic coupling circuit model can predict changes in the volume of the body fluid, which are essential in diagnosing and monitoring treatment of body fluid disorder. Individuals with high BMI would have higher time-dependent biological characteristic, lower metabolic rate, and lower rate of hydration.

  8. Topography of Lymphatic Markers in Human Iris and Ciliary Body.

    Science.gov (United States)

    Kaser-Eichberger, Alexandra; Schrödl, Falk; Trost, Andrea; Strohmaier, Clemens; Bogner, Barbara; Runge, Christian; Motloch, Karolina; Bruckner, Daniela; Laimer, Martin; Schlereth, Simona L; Heindl, Ludwig M; Reitsamer, Herbert A

    2015-07-01

    Reports of lymphatics in the anterior human uvea are contradictory. This might be caused due to a certain topography, which has not been considered yet. Therefore, here we systematically analyze iris and adjacent ciliary body with immunohistochemistry by combining various lymphatic markers. Human iris and ciliary body were obtained from cornea donors and prepared for cryosectioning. Cross sections of tissue blocks at 12/3/6/9 o'clock position and at corresponding intersections (1:30/4:30/7:30/10:30) were processed for immunohistochemistry of LYVE-1, PDPN, PROX1, FOXC2, VEGFR3, and CCL21, and when necessary, these lymphatic markers were combined with CD31, α-smooth muscle-actin, CD68, and 4',6-diamidino-2 phenylindole dihydrochloride (DAPI). Double, triple, and quadruple marker combinations were documented using confocal microscopy. Numerous podoplanin+ cells were mainly located at the anterior border of the iris while LYVE-1+ cells were distributed throughout the nonpigmented part. Both cell populations were PROX1/FOXC2/CCL21/VEGFR3-. Blood vessels, iris smooth muscles, and individual cells were VEGFR3+. While PDPN+ cells were rarely detected posteriorly of the iris root, many LYVE-1+ cells were present within the ciliary body muscle and villi. Within the muscle, occasionally PDPN+ vessel-like structures were detectable, but these were never colocalized with LYVE-1. Similar vessel-like structures were VEGFR3+/PROX1-/CCL21-, but CD31+. Further, ciliary muscle fibers and ciliary epithelium were immunoreactive for VEGFR3/CCL21, but were LYVE-1/PDPN-. A certain topography of structures at the various uvea-positions investigated was not obvious. The majority of LYVE-1+ cells displayed immunoreactivity for CD68. Lymphatic vessels colocalizing for at least two lymphatic markers were not detectable. Therefore, if present, putative lymphatic channels of the anterior uvea might display a different marker panel than generally presumed.

  9. Glucose transporter expression in human skeletal muscle fibers

    DEFF Research Database (Denmark)

    Gaster, M; Handberg, A; Beck-Nielsen, H

    2000-01-01

    amplification (TSA) technique to detect the localization of glucose transporter expression in human skeletal muscle. We found expression of GLUT-1, GLUT-3, and GLUT-4 in developing human muscle fibers showing a distinct expression pattern. 1) GLUT-1 is expressed in human skeletal muscle cells during gestation......, but its expression is markedly reduced around birth and is further reduced to undetectable levels within the first year of life; 2) GLUT-3 protein expression appears at 18 wk of gestation and disappears after birth; and 3) GLUT-4 protein is diffusely expressed in muscle cells throughout gestation, whereas...... after birth, the characteristic subcellular localization is as seen in adult muscle fibers. Our results show that GLUT-1, GLUT-3, and GLUT-4 seem to be of importance during muscle fiber growth and development. GLUT-5 protein was undetectable in fetal and adult skeletal muscle fibers. In adult muscle...

  10. Biodynamics of deformable human body motion

    Science.gov (United States)

    Strauss, A. M.; Huston, R. L.

    1976-01-01

    The objective is to construct a framework wherein the various models of human biomaterials fit in order to describe the biodynamic response of the human body. The behavior of the human body in various situations, from low frequency, low amplitude vibrations to impact loadings in automobile and aircraft crashes, is very complicated with respect to all aspects of the problem: materials, geometry and dynamics. The materials problem is the primary concern, but the materials problem is intimately connected with geometry and dynamics.

  11. Upper Body Venous Compliance Exceeds Lower Body Venous Compliance in Humans

    Science.gov (United States)

    Watenpaugh, Donald E.

    1996-01-01

    Human venous compliance hypothetically decreases from upper to lower body as a mechanism for maintenance of the hydrostatic indifference level 'headward' in the body, near the heart. This maintains cardiac filling pressure, and thus cardiac output and cerebral perfusion, during orthostasis. This project entailed four steps. First, acute whole-body tilting was employed to alter human calf and neck venous volumes. Subjects were tilted on a tilt table equipped with a footplate as follows: 90 deg, 53 deg, 30 deg, 12 deg, O deg, -6 deg, -12 deg, -6 deg, O deg, 12 deg, 30 deg, 53 deg, and 90 deg. Tilt angles were held for 30 sec each, with 10 sec transitions between angles. Neck volume increased and calf volume decreased during head-down tilting, and the opposite occurred during head-up tilt. Second, I sought to cross-validate Katkov and Chestukhin's (1980) measurements of human leg and neck venous pressures during whole-body tilting, so that those data could be used with volume data from the present study to calculate calf and neck venous compliance (compliance = (Delta)volume/(Delta)pressure). Direct measurements of venous pressures during postural chances and whole-body tilting confirmed that the local changes in venous pressures seen by Katkov and Chestukhin (1980) are valid. The present data also confirmed that gravitational changes in calf venous pressure substantially exceed those changes in upper body venous pressure. Third, the volume and pressure data above were used to find that human neck venous compliance exceeds calf venous compliance by a factor of 6, thereby upholding the primary hypothesis. Also, calf and neck venous compliance correlated significantly with each other (r(exp 2) = 0.56). Fourth, I wished to determine whether human calf muscle activation during head-up tilt reduces calf venous compliance. Findings from tilting and from supine assessments of relaxed calf venous compliance were similar, indicating that tilt-induced muscle activation is

  12. Whole body and muscle energy metabolism in preruminant calves: effects of nutrient synchrony and physical activity

    NARCIS (Netherlands)

    Borne, van den J.J.G.C.; Hocquette, J.F.; Verstegen, M.W.A.; Gerrits, W.J.J.

    2007-01-01

    The effects of asynchronous availability of amino acids and glucose on muscle composition and enzyme activities in skeletal muscle were studied in preruminant calves. It was hypothesized that decreased oxidative enzyme activities in muscle would explain a decreased whole body heat production with

  13. Secreted Protein Acidic and Rich in Cysteine (SPARC) in Human Skeletal Muscle

    DEFF Research Database (Denmark)

    Jørgensen, Louise H; Petersson, Stine J; Sellathurai, Jeeva

    2009-01-01

    indicated a function of SPARC in skeletal muscle. We therefore found it of interest to study SPARC expression in human skeletal muscle during development and in biopsies from Duchenne and Becker muscular dystrophy and congenital muscular dystrophy, congenital myopathy, inclusion body myositis...... in the majority of analyzed muscle biopsies (23 of 24), mainly in mononuclear cells of which few were pax7 positive. Myotubes and regenerating myofibers also expressed SPARC. The expression-degree seemed to reflect the severity of the lesion. In accordance with these in vivo findings, primary human...

  14. Molecular biology of human muscle disease

    Energy Technology Data Exchange (ETDEWEB)

    Dunne, P.W.; Epstein, H.F. (Baylor Coll. of Medicine, Houston, TX (United States))

    1991-01-01

    The molecular revolution that is transforming the entire biomedical field has had far-reaching impact in its application to inherited human muscle disease. The gene for Duchenne muscular dystrophy was one of the first cloned without knowledge of the defective protein product. This success was based upon the availability of key chromosomal aberrations that provided molecular landmarks for the disease locus. Subsequent discoveries regarding the mode of expression for this gene, the structure and localization of its protein product dystrophin, and molecular diagnosis of affected and carrier individuals constitute a paradigm for investigation of human genetics. Finding the gene for myotonic muscular dystrophy is requiring the brute force approach of cloning several million bases of DNA, identifying expressed sequences, and characterizing candidate genes. The gene that causes hypertrophic cardiomyopathy has been found serendipitously to be one of the genetic markers on chromosome 14, the {beta} myosin heavy chain.

  15. The Body Action Coding System I : Muscle activations during the perception and expression of emotion

    NARCIS (Netherlands)

    Huis In 't Veld, E.M.J.; van Boxtel, G.J.M.; de Gelder, B.

    2014-01-01

    Body postures provide clear signals about emotional expressions, but so far it is not clear what muscle patterns are associated with specific emotions. This study lays the groundwork for a Body Action Coding System by investigating what combinations of muscles are used for emotional bodily

  16. Testosterone and growth hormone improve body composition and muscle performance in older men

    Science.gov (United States)

    CONTEXT: Impairments in the pituitary-gonadal axis with aging are associated with loss of muscle mass and function and accumulation of upper body fat. OBJECTIVES: We tested the hypothesis that physiological supplementation with testosterone and GH together improves body composition and muscle perfor...

  17. Regulation of Metabolic Signaling in Human Skeletal Muscle

    DEFF Research Database (Denmark)

    Albers, Peter Hjorth

    Regulation of glucose metabolism, despite intense research through decades, is still not clear. Skeletal muscle is highly important for maintaining glucose homeostasis. Regulation of skeletal muscle glucose metabolism is influenced by protein signaling and changes in the activity of metabolic enz...... interval exercise). The abundance of signaling proteins and metabolic enzymes are in most cases different in type I and type II muscle fibers, indicating that their glucose metabolism is different.......Regulation of glucose metabolism, despite intense research through decades, is still not clear. Skeletal muscle is highly important for maintaining glucose homeostasis. Regulation of skeletal muscle glucose metabolism is influenced by protein signaling and changes in the activity of metabolic...... enzymes. Skeletal muscle consists of thousands of muscle fibers. These fibers can roughly be classified into type I and type II muscle fibers. The overall aim of this PhD thesis was to investigate the effect of insulin and exercise on human muscle fiber type specific metabolic signaling. The importance...

  18. Relationships among muscle dysmorphia characteristics, body image quality of life, and coping in males.

    Science.gov (United States)

    Tod, D; Edwards, C

    2015-09-01

    The purpose of this study was to examine relationships among bodybuilding dependence, muscle satisfaction, body image-related quality of life and body image-related coping strategies, and test the hypothesis that muscle dysmorphia characteristics may predict quality of life via coping strategies. Participants (294 males, Mage=20.5 years, SD=3.1) participated in a cross-sectional survey. Participants completed questionnaires assessing muscle satisfaction, bodybuilding dependence, body image-related quality of life and body image-related coping. Quality of life was correlated positively with muscle satisfaction and bodybuilding dependence but negatively with body image coping (Plife both directly and indirectly via body image coping strategies (as evidenced by the bias corrected and accelerated bootstrapped confidence intervals). These results provide preliminary evidence regarding the ways that muscularity concerns might influence body image-related quality of life. Copyright © 2014 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.

  19. Single muscle fibre contractile properties differ between body-builders, power athletes and control subjects

    OpenAIRE

    Meijer, J.P; Jaspers, R.T.; Rittweger, Jörn; SEYNNES, OLIVIER R.; Kamandulis, Sigitas; Brazaitis, M.; Skurvydas, A.; Pisot, Rado; Šimunič, Boštjan; Narici, Maco V.; Degens, Hans

    2016-01-01

    What is the central question of this study? Do the contractile properties of single muscle fibres differ between body-builders, power athletes and control subjects? •What is the main finding and its importance? Peak power normalized for muscle fibre volume in power athletes is higher than in control subjects. Compared with control subjects, maximal isometric tension (normalized for muscle fibre cross-sectional area) is lower in body-builders. Although this difference may be cause...

  20. Xanthine oxidase in human skeletal muscle following eccentric exercise

    DEFF Research Database (Denmark)

    Hellsten, Ylva; Frandsen, Ulrik; Orthenblad, N.

    1997-01-01

    1. The present study tested the hypothesis that the level of xanthine oxidase is elevated in injured human skeletal muscle in association with inflammatory events. Seven male subjects performed five bouts of strenuous one-legged eccentric exercise. Muscle biopsies from both the exercised and the ......1. The present study tested the hypothesis that the level of xanthine oxidase is elevated in injured human skeletal muscle in association with inflammatory events. Seven male subjects performed five bouts of strenuous one-legged eccentric exercise. Muscle biopsies from both the exercised...... the increase in xanthine oxidase in the muscle there were no detectable changes in the levels of muscle malondialdehyde or in plasma antioxidant capacity up to 4 days post-exercise. 5. It is concluded that eccentric exercise leads to an increased level of xanthine oxidase in human muscle and that the increase...

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

    Science.gov (United States)

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

    2016-07-01

    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.

  2. New Window into the Human Body

    Science.gov (United States)

    1985-01-01

    Michael Vannier, MD, a former NASA engineer, recognized the similarity between NASA's computerized image processing technology and nuclear magnetic resonance. With technical assistance from Kennedy Space Center, he developed a computer program for Mallinckrodt Institute of Radiology enabling Nuclear Magnetic Resonance (NMR) to scan body tissue for earlier diagnoses. Dr. Vannier feels that "satellite imaging" has opened a new window into the human body.

  3. Body composition in Pan paniscus compared with Homo sapiens has implications for changes during human evolution.

    Science.gov (United States)

    Zihlman, Adrienne L; Bolter, Debra R

    2015-06-16

    The human body has been shaped by natural selection during the past 4-5 million years. Fossils preserve bones and teeth but lack muscle, skin, fat, and organs. To understand the evolution of the human form, information about both soft and hard tissues of our ancestors is needed. Our closest living relatives of the genus Pan provide the best comparative model to those ancestors. Here, we present data on the body composition of 13 bonobos (Pan paniscus) measured during anatomical dissections and compare the data with Homo sapiens. These comparative data suggest that both females and males (i) increased body fat, (ii) decreased relative muscle mass, (iii) redistributed muscle mass to lower limbs, and (iv) decreased relative mass of skin during human evolution. Comparison of soft tissues between Pan and Homo provides new insights into the function and evolution of body composition.

  4. The expression of HSP in human skeletal muscle. Effects of muscle fiber phenotype and training background

    DEFF Research Database (Denmark)

    Folkesson, Mattias; Mackey, Abigail L; Langberg, Henning;

    2013-01-01

    AIM: Exercise-induced adaptations of skeletal muscle are related to training mode and can be muscle fibre type specific. This study aimed to investigate heat shock protein expression in type I and type II muscle fibres in resting skeletal muscle of subjects with different training backgrounds...... HSPs in human skeletal muscle is influenced by muscle fibre phenotype. The fibre type specific expression of HSP70 is influenced by resistance and endurance training whereas those of αB-crystallin and HSP27 are influenced only by endurance training suggesting the existence of a training......-modality specific action on the adaptive processes including heat shock proteins in human skeletal muscle. This article is protected by copyright. All rights reserved....

  5. Muscle triacylglycerol and hormone-sensitive lipase activity in untrained and trained human muscles

    DEFF Research Database (Denmark)

    Helge, Jørn Wulff; Biba, Taus O; Galbo, Henrik

    2006-01-01

    During exercise, triacylglycerol (TG) is recruited in skeletal muscles. We hypothesized that both muscle hormone-sensitive lipase (HSL) activity and TG recruitment would be higher in trained than in untrained subjects in response to prolonged exercise. Healthy male subjects (26 +/- 1 years, body ...

  6. Comparison of rotator cuff muscle architecture between humans and other selected vertebrate species

    Science.gov (United States)

    Mathewson, Margie A.; Kwan, Alan; Eng, Carolyn M.; Lieber, Richard L.; Ward, Samuel R.

    2014-01-01

    In this study, we compare rotator cuff muscle architecture of typically used animal models with that of humans and quantify the scaling relationships of these muscles across mammals. The four muscles that correspond to the human rotator cuff – supraspinatus, infraspinatus, subscapularis and teres minor – of 10 commonly studied animals were excised and subjected to a series of comparative measurements. When body mass among animals was regressed against physiological cross-sectional area, muscle mass and normalized fiber length, the confidence intervals suggested geometric scaling but did not exclude other scaling relationships. Based on the architectural difference index (ADI), a combined measure of fiber length-to-moment arm ratio, fiber length-to-muscle length ratio and the fraction of the total rotator cuff physiological cross-sectional area contributed by each muscle, chimpanzees were found to be the most similar to humans (ADI=2.15), followed closely by capuchins (ADI=2.16). Interestingly, of the eight non-primates studied, smaller mammals such as mice, rats and dogs were more similar to humans in architectural parameters compared with larger mammals such as sheep, pigs or cows. The force production versus velocity trade-off (indicated by fiber length-to-moment arm ratio) and the excursion ability (indicated by fiber length-to-muscle length ratio) of humans were also most similar to those of primates, followed by the small mammals. Overall, primates provide the best architectural representation of human muscle architecture. However, based on the muscle architectural parameters of non-primates, smaller rather than larger mammals may be better models for studying muscles related to the human rotator cuff. PMID:24072803

  7. Comparison of rotator cuff muscle architecture between humans and other selected vertebrate species.

    Science.gov (United States)

    Mathewson, Margie A; Kwan, Alan; Eng, Carolyn M; Lieber, Richard L; Ward, Samuel R

    2014-01-15

    In this study, we compare rotator cuff muscle architecture of typically used animal models with that of humans and quantify the scaling relationships of these muscles across mammals. The four muscles that correspond to the human rotator cuff - supraspinatus, infraspinatus, subscapularis and teres minor - of 10 commonly studied animals were excised and subjected to a series of comparative measurements. When body mass among animals was regressed against physiological cross-sectional area, muscle mass and normalized fiber length, the confidence intervals suggested geometric scaling but did not exclude other scaling relationships. Based on the architectural difference index (ADI), a combined measure of fiber length-to-moment arm ratio, fiber length-to-muscle length ratio and the fraction of the total rotator cuff physiological cross-sectional area contributed by each muscle, chimpanzees were found to be the most similar to humans (ADI=2.15), followed closely by capuchins (ADI=2.16). Interestingly, of the eight non-primates studied, smaller mammals such as mice, rats and dogs were more similar to humans in architectural parameters compared with larger mammals such as sheep, pigs or cows. The force production versus velocity trade-off (indicated by fiber length-to-moment arm ratio) and the excursion ability (indicated by fiber length-to-muscle length ratio) of humans were also most similar to those of primates, followed by the small mammals. Overall, primates provide the best architectural representation of human muscle architecture. However, based on the muscle architectural parameters of non-primates, smaller rather than larger mammals may be better models for studying muscles related to the human rotator cuff.

  8. Investigation of the effects of human body stability on joint angles’ prediction

    Energy Technology Data Exchange (ETDEWEB)

    Pasha Zanoosi, A. A., E-mail: aliakbar.pasha@yahoo.com, E-mail: aliakbar.pasha@qiau.ac.ir [Islamic Azad University, Faculty of Industrial & Mechanical Engineering, Qazvin Branch (Iran, Islamic Republic of); Naderi, D.; Sadeghi-Mehr, M.; Feri, M. [Bu Ali-Sina University, Mechanical Engineering Department, Faculty of Engineering (Iran, Islamic Republic of); Beheshtiha, A. Sh. [Leibniz Universität Hannover, Institute of Mechanics and Computational Mechanics (Germany); Fallahnejad, K. [Flinders University, Discipline of Mechanical Engineering, School of Computer Science, Engineering and Mathematics (Australia)

    2015-10-15

    Loosing stability control in elderly or paralyzed has motivated researchers to study how a stability control system works and how to determine its state at every time instant. Studying the stability of a human body is not only an important problem from a scientific viewpoint, but also finally leads to new designs of prostheses and orthoses and rehabilitation methods. Computer modeling enables researchers to study and describe the reactions and propose a suitable and optimized motion pattern to strengthen the neuromuscular system and helps a human body maintain its stability. A perturbation as a tilting is exposed to an underfoot plate of a musculoskeletal model of the body to study the stability. The studied model of a human body included four links and three degrees of freedom with eight muscles in the sagittal plane. Lagrangian dynamics was used for deriving equations of motion and muscles were modeled using Hill’s model. Using experimental data of joint trajectories for a human body under tilting perturbation, forward dynamics has been applied to predict joint trajectories and muscle activation. This study investigated the effects of stability on predicting body joints’ motion. A new stability function for a human body, based on the zero moment point, has been employed in a forward dynamics procedure using a direct collocation method. A multi-objective optimization based on genetic algorithm has been proposed to employ stability as a robotic objective function along with muscle stresses as a biological objective function. The obtained results for joints’ motion were compared to experimental data. The results show that, for this type of perturbations, muscle stresses are in conflict with body stability. This means that more body stability requires more stresses in muscles and reverse. Results also show the effects of the stability objective function in better prediction of joint trajectories.

  9. A muscle stem cell for every muscle: variability of satellite cell biology among different muscle groups

    OpenAIRE

    Matthew Emerson Randolph; Pavlath, Grace K.

    2015-01-01

    The human body contains approximately 640 individual skeletal muscles. Despite the fact that all of these muscles are composed of striated muscle tissue, the biology of these muscles and their associated muscle stem cell populations are quite diverse. Skeletal muscles are affected differentially by various muscular dystrophies, such that certain genetic mutations specifically alter muscle function in only a subset of muscles. Additionally, defective muscle stem cells have been implicated in t...

  10. Localization of nitric oxide synthase in human skeletal muscle

    DEFF Research Database (Denmark)

    Frandsen, Ulrik; Lopez-Figueroa, M.; Hellsten, Ylva

    1996-01-01

    The present study investigated the cellular localization of the neuronal type I and endothelial type III nitric oxide synthase in human skeletal muscle. Type I NO synthase immunoreactivity was found in the sarcolemma and the cytoplasm of all muscle fibres. Stronger immunoreactivity was expressed...... I NO synthase immunoreactivity and NADPH diaphorase activity. Type III NO synthase immunoreactivity was observed both in the endothelium of larger vessels and of microvessels. The results establish that human skeletal muscle expresses two different constitutive isoforms of NO synthase in different...... endothelium is consistent with a role for NO in the control of blood flow in human skeletal muscle....

  11. Cryopreservation of human skeletal muscle impairs mitochondrial function

    DEFF Research Database (Denmark)

    Larsen, Steen; Wright-Paradis, C; Gnaiger, E

    2012-01-01

    Previous studies have investigated if cryopreservation is a viable approach for functional mitochondrial analysis. Different tissues have been studied, and conflicting results have been published. The aim of the present study was to investigate if mitochondria in human skeletal muscle maintain...... loss from the mitochondria. The results from this study demonstrate that normal mitochondrial functionality is not maintained in cryopreserved human skeletal muscle samples....... functionality after long term cryopreservation (1 year). Skeletal muscle samples were preserved in dimethyl sulfoxide (DMSO) for later analysis. Human skeletal muscle fibres were thawed and permeabilised with saponin, and mitochondrial respiration was measured by high-resolution respirometry. The capacity...

  12. Cryopreservation of human skeletal muscle impairs mitochondrial function

    DEFF Research Database (Denmark)

    Larsen, S; Wright-Paradis, C; Gnaiger, E

    2012-01-01

    Previous studies have investigated if cryopreservation is a viable approach for functional mitochondrial analysis. Different tissues have been studied, and conflicting results have been published. The aim of the present study was to investigate if mitochondria in human skeletal muscle maintain...... functionality after long term cryopreservation (1 year). Skeletal muscle samples were preserved in dimethyl sulfoxide (DMSO) for later analysis. Human skeletal muscle fibres were thawed and permeabilised with saponin, and mitochondrial respiration was measured by high-resolution respirometry. The capacity...... loss from the mitochondria. The results from this study demonstrate that normal mitochondrial functionality is not maintained in cryopreserved human skeletal muscle samples....

  13. Light bodies in human pituitary adenomas

    DEFF Research Database (Denmark)

    Holck, S; Wewer, U M; Albrechtsen, R

    1987-01-01

    Light bodies are large cytoplasmic granules originally described in the gonadotrophic cells of the rat pituitary gland. In order to determine whether similar bodies occur in the human anterior pituitary gland, 89 pituitary adenomas and periadenomatous tissue from 20 cases were examined by transmi......Light bodies are large cytoplasmic granules originally described in the gonadotrophic cells of the rat pituitary gland. In order to determine whether similar bodies occur in the human anterior pituitary gland, 89 pituitary adenomas and periadenomatous tissue from 20 cases were examined...... by transmission electron microscopy. Double membrane bound bodies with filamentous internal structure identical to rodent light bodies were identified in 10 hormone-producing adenomas: 5 PRL, 1 PRL-GH, 2 GH, and 2 ACTH-producing tumours. No light bodies were found in the remaining 79 tumours nor in the pituitary...... cells in periadenomatous tissue from 20 cases. These results show that some human pituitary adenomas may contain light bodies identical to those seen in gonadotrophs of rat pituitary....

  14. Vanadium in foods and in human body fluids and tissues.

    Science.gov (United States)

    Byrne, A R; Kosta, L

    1978-07-01

    Using neutron activation analysis, vanadium was analysed in a range of foods, human body fluids and tissues. On the basis of these results and those of other workers, it was concluded that daily dietary intake amounts to some tens of micrograms. Analysis of body fluids (including milk, blood and excreta) and organs and tissues provided an estimate for the total body pool of vanadium in man of about 100 microgram. Vanadium was not detectable in blood and urine at the level of 0.3 ng/g, while low levels were found in muscle, fat, bone, teeth and other tissues. The relationship between dietary intake to pulmonary absorption is discussed in relation to the occurrence of vanadium in man-made air particulates. The very low levels found in milks and eggs suggest minimal vanadium requirements in growth. The findings are discussed in the light of previous results and also in relation to the possible essentiality of vanadium.

  15. Avian pectoral muscle size rapidly tracks body mass changes during flight, fasting and fuelling.

    Science.gov (United States)

    Lindström, A; Kvist, A; Piersma, T; Dekinga, A; Dietz, M W

    2000-03-01

    We used ultrasonic imaging to monitor short-term changes in the pectoral muscle size of captive red knots Calidris canutus. Pectoral muscle thickness changed rapidly and consistently in parallel with body mass changes caused by flight, fasting and fuelling. Four knots flew repeatedly for 10 h periods in a wind tunnel. Over this period, pectoral muscle thickness decreased in parallel with the decrease in body mass. The change in pectoral muscle thickness during flight was indistinguishable from that during periods of natural and experimental fasting and fuelling. The body-mass-related variation in pectoral muscle thickness between and within individuals was not related to the amount of flight, indicating that changes in avian muscle do not require power-training as in mammals. Our study suggests that it is possible for birds to consume and replace their flight muscles on a time scale short enough to allow these muscles to be used as part of the energy supply for migratory flight. The adaptive significance of the changes in pectoral muscle mass cannot be explained by reproductive needs since our knots were in the early winter phase of their annual cycle. Instead, pectoral muscle mass changes may reflect (i) the breakdown of protein during heavy exercise and its subsequent restoration, (ii) the regulation of flight capacity to maintain optimal flight performance when body mass varies, or (iii) the need for a particular protein:fat ratio in winter survival stores.

  16. Red muscle function in stiff-bodied swimmers: there and almost back again.

    Science.gov (United States)

    Syme, Douglas A; Shadwick, Robert E

    2011-05-27

    Fishes with internalized and endothermic red muscles (i.e. tunas and lamnid sharks) are known for a stiff-bodied form of undulatory swimming, based on unique muscle-tendon architecture that limits lateral undulation to the tail region even though the red muscle is shifted anteriorly. A strong convergence between lamnid sharks and tunas in these features suggests that thunniform swimming might be evolutionarily tied to this specialization of red muscle, but recent observations on the common thresher shark (Alopias vulpinus) do not support this view. Here, we review the fundamental features of the locomotor systems in lamnids and tunas, and present data on in vivo muscle function and swimming mechanics in thresher sharks. These results suggest that the presence of endothermic and internalized red muscles alone in a fish does not predict or constrain the swimming mode to be thunniform and, indeed, that the benefits of this type of muscle may vary greatly as a consequence of body size.

  17. Human skeletal muscle fibroblasts stimulate in vitro myogenesis and in vivo muscle regeneration.

    Science.gov (United States)

    Mackey, Abigail L; Magnan, Mélanie; Chazaud, Bénédicte; Kjaer, Michael

    2017-08-01

    Accumulation of skeletal muscle extracellular matrix is an unfavourable characteristic of many muscle diseases, muscle injury and sarcopenia. The extent of cross-talk between fibroblasts, as the source of matrix protein, and satellite cells in humans is unknown. We studied this in human muscle biopsies and cell-culture studies. We observed a strong stimulation of myogenesis by human fibroblasts in cell culture. In biopsies collected 30 days after a muscle injury protocol, fibroblast number increased to four times control levels, where fibroblasts were found to be preferentially located immediately surrounding regenerating muscle fibres. These novel findings indicate an important role for fibroblasts in supporting the regeneration of muscle fibres, potentially through direct stimulation of satellite cell differentiation and fusion, and contribute to understanding of cell-cell cross-talk during physiological and pathological muscle remodelling. Accumulation of skeletal muscle extracellular matrix is an unfavourable characteristic of many muscle diseases, muscle injury and sarcopenia. In addition to the indispensable role satellite cells play in muscle regeneration, there is emerging evidence in rodents for a regulatory influence on fibroblast activity. However, the influence of fibroblasts on satellite cells and muscle regeneration in humans is unknown. The purpose of this study was to investigate this in vitro and during in vivo regeneration in humans. Following a muscle injury protocol in young healthy men (n = 7), the number of fibroblasts (TCF7L2+), satellite cells (Pax7+), differentiating myogenic cells (myogenin+) and regenerating fibres (neonatal/embryonic myosin+) was determined from biopsy cross-sections. Fibroblasts and myogenic precursor cells (MPCs) were also isolated from human skeletal muscle (n = 4) and co-cultured using different cell ratios, with the two cell populations either in direct contact with each other or separated by a permeable

  18. Closing the Loop: Integrating Body, Muscle and Environment with Locomotion Central Pattern Generators

    Science.gov (United States)

    2013-06-30

    simple closed-loop model in which a CPG produces a pattern of muscle activation which is modified by sensory feedback related to body curvature . (a...by a complex interaction of the neural circuits in the spinal cord and brain, the body, the muscles, sensory organs and the environment. With- out...feedback related to body curvature . 2.1 Computation of optimal feedback for the control of locomotion We have a developed a general method of computing

  19. Pronounced effects of acute endurance exercise on gene expression in resting and exercising human skeletal muscle.

    Directory of Open Access Journals (Sweden)

    Milène Catoire

    Full Text Available Regular physical activity positively influences whole body energy metabolism and substrate handling in exercising muscle. While it is recognized that the effects of exercise extend beyond exercising muscle, it is unclear to what extent exercise impacts non-exercising muscles. Here we investigated the effects of an acute endurance exercise bouts on gene expression in exercising and non-exercising human muscle. To that end, 12 male subjects aged 44-56 performed one hour of one-legged cycling at 50% W(max. Muscle biopsies were taken from the exercising and non-exercising leg before and immediately after exercise and analyzed by microarray. One-legged cycling raised plasma lactate, free fatty acids, cortisol, noradrenalin, and adrenalin levels. Surprisingly, acute endurance exercise not only caused pronounced gene expression changes in exercising muscle but also in non-exercising muscle. In the exercising leg the three most highly induced genes were all part of the NR4A family. Remarkably, many genes induced in non-exercising muscle were PPAR targets or related to PPAR signalling, including PDK4, ANGPTL4 and SLC22A5. Pathway analysis confirmed this finding. In conclusion, our data indicate that acute endurance exercise elicits pronounced changes in gene expression in non-exercising muscle, which are likely mediated by changes in circulating factors such as free fatty acids. The study points to a major influence of exercise beyond the contracting muscle.

  20. Topography of the femoral nerve in relation to components of the iliopsoas muscle in human fetuses.

    Science.gov (United States)

    Jakubowicz, M

    1991-01-01

    Studies were performed on 60 human fetuses of both sexes of 35 to 365 mm C.-R. length (9-40 weeks). The psoas minor muscle was found in 25.8% of cases independently of sex and body side. In 6.45% of cases the muscle continued into psoas major muscle by short, weakly developed tendon. In 97.5% of studied fetuses junctions between tendons of psoas major and iliacus muscles was observed. In 2.5% of cases an independent, short tendon was found in the half of length of the iliacus muscle. In 7.5% of cases connection between the psoas major and iliacus muscles was found. In all cases femoral nerve originated from the lumbar plexus between two layers of the psoas major muscle and it ran in the groove between the psoas major and iliacus muscles towards the muscular lacuna. In 5.0% of cases the nerve divided into crura. In 2.5% of cases the crura embraced anteriorly and posteriorly bundles of the psoas major muscle as well as in 2.5% of cases bundles of the iliacus muscle.

  1. The proprioceptive senses: their roles in signaling body shape, body position and movement, and muscle force.

    Science.gov (United States)

    Proske, Uwe; Gandevia, Simon C

    2012-10-01

    This is a review of the proprioceptive senses generated as a result of our own actions. They include the senses of position and movement of our limbs and trunk, the sense of effort, the sense of force, and the sense of heaviness. Receptors involved in proprioception are located in skin, muscles, and joints. Information about limb position and movement is not generated by individual receptors, but by populations of afferents. Afferent signals generated during a movement are processed to code for endpoint position of a limb. The afferent input is referred to a central body map to determine the location of the limbs in space. Experimental phantom limbs, produced by blocking peripheral nerves, have shown that motor areas in the brain are able to generate conscious sensations of limb displacement and movement in the absence of any sensory input. In the normal limb tendon organs and possibly also muscle spindles contribute to the senses of force and heaviness. Exercise can disturb proprioception, and this has implications for musculoskeletal injuries. Proprioceptive senses, particularly of limb position and movement, deteriorate with age and are associated with an increased risk of falls in the elderly. The more recent information available on proprioception has given a better understanding of the mechanisms underlying these senses as well as providing new insight into a range of clinical conditions.

  2. Dark Matter collisions with the Human Body

    CERN Document Server

    Freese, Katherine

    2012-01-01

    We investigate the interactions of Weakly Interacting Massive Particles (WIMPs) with nuclei in the human body. We are motivated by the fact that WIMPs are excellent candidates for the dark matter in the Universe. Our estimates use a 70 kg human and a variety of WIMP masses and cross-sections. The contributions from individual elements in the body are presented and it is found that the dominant contribution is from scattering off of oxygen (hydrogen) nuclei for the spin-independent (spin-dependent) interactions. For the case of 60 GeV WIMPs, we find that, of the billions of WIMPs passing through a human body per second, roughly ~10 WIMPs hit one of the nuclei in the human body in an average year, if the scattering is at the maximum consistent with current bounds on WIMP interactions. We also study the 10-20 GeV WIMPs with much larger cross-sections that best fit the DAMA, COGENT, and CRESST data sets and find much higher rates: in this case as many as $10^5$ WIMPs hit a nucleus in the human body in an average ...

  3. Multi-frequency bioimpedance in human muscle assessment

    DEFF Research Database (Denmark)

    Bartels, Else Marie; Sørensen, Emma Rudbæk; Harrison, Adrian Paul

    2015-01-01

    Bioimpedance analysis (BIA) is a well-known and tested method for body mass and muscular health assessment. Multi-frequency BIA (mfBIA) equipment now makes it possible to assess a particular muscle as a whole, as well as looking at a muscle at the fiber level. The aim of this study was to test......, contracted state, and cell transport/metabolic activity, which relate to muscle performance. Our findings indicate that mfBIA provides a noninvasive, easily measurable and very precise momentary assessment of skeletal muscles....

  4. THE CAPILLARY PATTERN IN HUMAN MASSETER MUSCLE DURING AGEING

    Directory of Open Access Journals (Sweden)

    Erika Cvetko

    2013-10-01

    Full Text Available The effect of ageing on the capillary network in skeletal muscles has produced conflicting results in both, human and animals studies. Some of the inconsistencies are due to non-comparable and biased methods that were applied on thin transversal sections, especially in muscles with complicated morphological structures, such as in human masseter muscle. We present a new immunohistochemical method for staining capillaries and muscle fibres in 100 µm thick sections as well as novel approach to 3D visualization of capillaries and muscle fibres. Applying confocal microscopy and virtual 3D stereological grids, or tracing capillaries in virtual reality, length of capillaries within a muscle volume or length of capillaries adjacent to muscle fibre per fibre length, fibre surface or fibre volume were evaluated in masseter muscle of young and old subjects by an unbiased approach. Our findings show that anatomic capillarity is well maintained in masseter muscle in old subjects; however, vascular remodelling occurs with age, which could be a response to changed muscle function and age-related muscle fibre type transformations.

  5. Determination of human muscle protein fractional synthesis rate

    DEFF Research Database (Denmark)

    Bornø, Andreas; Hulston, Carl J; van Hall, Gerrit

    2014-01-01

    In the present study, different MS methods for the determination of human muscle protein fractional synthesis rate (FSR) using [ring-(13)C6 ]phenylalanine as a tracer were evaluated. Because the turnover rate of human skeletal muscle is slow, only minute quantities of the stable isotopically......-MS/MS) and GC-tandem MS (GC-MS/MS) have made these techniques an option for human muscle FSR measurements. Human muscle biopsies were freeze dried, cleaned, and hydrolyzed, and the amino acids derivatized using either N-acetyl-n-propyl, phenylisothiocyanate, or N.......89 ± 0.01, P muscle FSR, (2) LC-MS/MS comes quite close and is a good alternative when tissue quantities are too small for GC-C-IRMS, and (3) If GC-MS/MS is to be used, then the HFBA derivative should be used instead...

  6. Muscle fascicle strains in human gastrocnemius during backward downhill walking.

    Science.gov (United States)

    Hoffman, B W; Cresswell, A G; Carroll, T J; Lichtwark, G A

    2014-06-01

    Extensive muscle damage can be induced in isolated muscle preparations by performing a small number of stretches during muscle activation. While typically these fiber strains are large and occur over long lengths, the extent of exercise-induced muscle damage (EIMD) observed in humans is normally less even when multiple high-force lengthening actions are performed. This apparent discrepancy may be due to differences in muscle fiber and tendon dynamics in vivo; however, muscle and tendon strains have not been quantified during muscle-damaging exercise in humans. Ultrasound and an infrared motion analysis system were used to measure medial gastrocnemius fascicle length and lower limb kinematics while humans walked backward, downhill for 1 h (inducing muscle damage), and while they walked briefly forward on the flat (inducing no damage). Supramaximal tibial nerve stimulation, ultrasound, and an isokinetic dynamometer were used to quantify the fascicle length-torque relationship pre- and 2 h postexercise. Torque decreased ~23%, and optimal fascicle length shifted rightward ~10%, indicating that EIMD occurred during the damage protocol even though medial gastrocnemius fascicle stretch amplitude was relatively small (~18% of optimal fascicle length) and occurred predominantly within the ascending limb and plateau region of the length-torque curve. Furthermore, tendon contribution to overall muscle-tendon unit stretch was ~91%. The data suggest the compliant tendon plays a role in attenuating muscle fascicle strain during backward walking in humans, thus minimizing the extent of EIMD. As such, in situ or in vitro mechanisms of muscle damage may not be applicable to EIMD of the human gastrocnemius muscle. Copyright © 2014 the American Physiological Society.

  7. GH receptor signaling in skeletal muscle and adipose tissue in human subjects following exposure to an intravenous GH bolus

    DEFF Research Database (Denmark)

    Jørgensen, Jens O L; Jessen, Niels; Pedersen, Steen Bønløkke

    2006-01-01

    Growth hormone (GH) regulates muscle and fat metabolism, which impacts on body composition and insulin sensitivity, but the underlying GH signaling pathways have not been studied in vivo in humans. We investigated GH signaling in biopsies from muscle and abdominal fat obtained 30 (n = 3) or 60 (n...... in vivo model may be used to study the mechanisms subserving the actions of GH on substrate metabolism and insulin sensitivity in muscle and fat....

  8. Molecular aging and rejuvenation of human muscle stem cells

    DEFF Research Database (Denmark)

    Carlson, Morgan E; Suetta, Charlotte; Conboy, Michael J

    2009-01-01

    Very little remains known about the regulation of human organ stem cells (in general, and during the aging process), and most previous data were collected in short-lived rodents. We examined whether stem cell aging in rodents could be extrapolated to genetically and environmentally variable humans....... Our findings establish key evolutionarily conserved mechanisms of human stem cell aging. We find that satellite cells are maintained in aged human skeletal muscle, but fail to activate in response to muscle attrition, due to diminished activation of Notch compounded by elevated transforming growth...... factor beta (TGF-beta)/phospho Smad3 (pSmad3). Furthermore, this work reveals that mitogen-activated protein kinase (MAPK)/phosphate extracellular signal-regulated kinase (pERK) signalling declines in human muscle with age, and is important for activating Notch in human muscle stem cells. This molecular...

  9. A comparison between muscle function and body composition in anorexia nervosa: the effect of refeeding.

    Science.gov (United States)

    Russell, D M; Prendergast, P J; Darby, P L; Garfinkel, P E; Whitwell, J; Jeejeebhoy, K N

    1983-08-01

    Skeletal muscle function, body composition (total body nitrogen and total body potassium) and standard parameters of nutritional assessment were measured in six severely depleted patients with primary anorexia nervosa, both on admission and during oral refeeding. The function of the adductor pollicis muscle was assessed by electrical stimulation of the ulnar nerve. On admission muscle function was markedly abnormal in the patients with anorexia nervosa (n = 6) compared with normal subjects (n = 22), with a significant increase in the force of contraction at 10 Hz, with a mean +/- SEM of 48.0 +/- 3.7% and 28.8 +/- 1.2%, respectively (p less than 0.001). There was slowing of the maximal relaxation rate, 6.6 +/- 0.6% and 9.6 +/- 0.2%, respectively (p less than 0.001) and increased muscle fatigue 18.6 +/- 5.9% and 3.5 +/- 0.8%, respectively (p less than 0.01). Initially, the mean serum albumin was normal (4.0 +/- 0.1 g/dl), although there was evidence of severe depletion of somatic protein stores, with a low total body nitrogen and creatinine-height index. Within 4 wk of oral refeeding, maximal relaxation rate and muscle fatigability were restored to normal, and within 8 wk all parameters of muscle function were normal. During the study total body nitrogen increased by only 13% and was still 19.4% below the predicted normal total body nitrogen, whereas total body potassium increased by 32% and body fat by 46%. Normalization of muscle function may be related to restoration of muscle electrolytes rather than repletion of body nitrogen.

  10. Communication channel modeling of human forearm with muscle fiber tissue characteristics.

    Science.gov (United States)

    Zhang, Shuang; Pun, Sio Hang; Mak, Peng Un; Qin, Yu-Ping; Liu, Yi-He; Vai, Mang I

    2016-09-14

    Human-Body Communication (HBC) is a wireless communication method using the human body tissue as a transmission medium for signals. This paper on the basis of human muscle fiber tissues' characteristics, it is first proposed to establish the analytical model of galvanic coupling human-body communication channel. In this model, the parallel and the transverse electrical characteristics of muscular tissue are fully considered, and the model accurately presents the transmission mechanism of galvanic coupling human-body communication signals in the channel. At last, through compare with the experimental results and calculation results, the maximum error of the model is 22.4% and the average error is 14.2% within the frequency range.

  11. Tirasemtiv amplifies skeletal muscle response to nerve activation in humans

    OpenAIRE

    Hansen,Richard; Saikali, Khalil G; Chou, Willis; Alan J Russell; Chen, Michael M.; Vijayakumar, Vipin; Stoltz, Randall R.; Baudry, Stephane; Enoka, Roger M.; Morgans, David J; Wolff, Andrew A.; Malik, Fady I

    2014-01-01

    Introduction: In this study we tested the hypothesis that tirasemtiv, a selective fast skeletal muscle troponin activator that sensitizes the sarcomere to calcium, could amplify the response of muscle to neuromuscular input in humans. Methods: Healthy men received tirasemtiv and placebo in a randomized, double-blind, 4-period, crossover design. The deep fibular nerve was stimulated transcutaneously to activate the tibialis anterior muscle and produce dorsiflexion of the foot. The force–freque...

  12. Muscle-specific expression of hypoxia-inducible factor in human skeletal muscle

    DEFF Research Database (Denmark)

    Mounier, Rémi; Pedersen, Bente Klarlund; Plomgaard, Peter

    2010-01-01

    from triceps brachii (characterized by a high proportion of type II fibres), from soleus (characterized by a high proportion of type I fibres) and from vastus lateralis (characterized by an equal proportion of type I and II fibres). The hypothesis was that type I muscle fibres would have lower HIF-1...... a significantly higher VEGF protein content than vastus lateralis and triceps muscle. In conclusion, we have shown that there are muscle-specific differences in HIF-1alpha and VEGF expression within human skeletal muscle at rest in normoxic conditions. Recent results, when combined with the findings described...

  13. Avian pectoral muscle size rapidly tracks body mass changes during flight, fasting and fuelling

    NARCIS (Netherlands)

    Lindstrom, A; Kvist, A; Piersma, T; Dekinga, A; Dietz, MW; Lindström, Åke

    2000-01-01

    We used ultrasonic imaging to monitor short-term changes in the pectoral muscle size of captive red knots Calidris canutus. Pectoral muscle thickness changed rapidly and consistently in parallel with body mass changes caused by flight, fasting;and fuelling. Four knots hew repeatedly for 10h periods

  14. Physical activity is associated with retained muscle metabolism in human myotubes challenged with palmitate

    DEFF Research Database (Denmark)

    Green, C J; Bunprajun, T; Pedersen, B K

    2013-01-01

      The aim of this study was to investigate whether physical activity is associated with preserved muscle metabolism in human myotubes challenged with saturated fatty acids. Human muscle satellite cells were isolated from sedentary or active individuals and differentiated into myocytes in culture...... and correlated positively to JNK phosphorylation. In conclusion, muscle satellite cells retain metabolic differences associated with physical activity. Physical activity partially protects myocytes from fatty acid-induced insulin resistance and inactivity is associated with dysregulation of metabolism...... in satellite cells challenged with palmitate. Although the benefits of physical activity on whole body physiology have been well investigated, this paper presents novel findings that both diet and exercise impact satellite cells directly. Given the fact that satellite cells are important for muscle maintenance...

  15. Simultaneous 31P NMR spectroscopy and EMG in exercising and recovering human skeletal muscle: technical aspects

    DEFF Research Database (Denmark)

    Vestergaard-Poulsen, P; Thomsen, C; Sinkjaer, T

    1994-01-01

    . A nonmagnetic ergometer was used for ankle dorsiflexions that activated only the anterior tibial muscle as verified by post exercise imaging. The coil design and the adiabatic sech/tanh pulse improved sensitivity by 45% and 56% respectively, compared with standard techniques. Simultaneous electromyographic......The bioenergetics of human skeletal muscle can be studied by 31P NMR spectroscopy (31P-MRS) and by surface electromyography (SEMG). Simultaneous 31P-MRS and SEMG permit accurate and noninvasive studies of the correlation between metabolic and electrical changes in exercising and recovering human...... skeletal muscle, a relationship that is still poorly understood. This study describes the optimization of skeletal muscle 31P-MRS in a whole-body magnet, involving surface coil design, utilization of adiabatic radio frequency pulses and advanced time-domain fitting, to the technical design of SEMG...

  16. [The solidarity of the human body].

    Science.gov (United States)

    Bioy, Xavier

    2014-06-01

    The legal and bioethical regulation of the uses of the elements of the human body can be described by means of the concept of solidarity. From the French example, we can so show that the State tries to frame solidarities which already exist, for example between people who share the same genome, in the family, or, on the contrary, tent to impose or to direct the sharing of the human biological resources (organs, tissues, gametes, stem cell...).

  17. Effect of whole-body vibration on muscle strength, spasticity, and ...

    African Journals Online (AJOL)

    Effect of whole-body vibration on muscle strength, spasticity, and motor performance in spastic diplegic cerebral palsy children. ... program for spastic diplegic CP and the WBV group received the same program in addition to WBV training.

  18. High efficiency in human muscle: an anomaly and an opportunity?

    Science.gov (United States)

    Nelson, Frank E; Ortega, Justus D; Jubrias, Sharon A; Conley, Kevin E; Kushmerick, Martin J

    2011-08-15

    Can human muscle be highly efficient in vivo? Animal muscles typically show contraction-coupling efficiencies FDI) muscle of the hand has an efficiency value in vivo of 68%. We examine two key factors that could account for this apparently high efficiency value: (1) transfer of cross-bridge work into mechanical work and (2) the use of elastic energy to do external work. Our analysis supports a high contractile efficiency reflective of nearly complete transfer of muscular to mechanical work with no contribution by recycling of elastic energy to mechanical work. Our survey of reported contraction-coupling efficiency values puts the FDI value higher than typical values found in small animals in vitro but within the range of values for human muscle in vivo. These high efficiency values support recent studies that suggest lower Ca(2+) cycling costs in working contractions and a decline in cost during repeated contractions. In the end, our analysis indicates that the FDI muscle may be exceptional in having an efficiency value on the higher end of that reported for human muscle. Thus, the FDI muscle may be an exception both in contraction-coupling efficiency and in Ca(2+) cycling costs, which makes it an ideal muscle model system offering prime conditions for studying the energetics of muscle contraction in vivo.

  19. Observational Study on the Occurrence of Muscle Spindles in Human Digastric and Mylohyoideus Muscles

    Directory of Open Access Journals (Sweden)

    Daniele Saverino

    2014-01-01

    Full Text Available Although the occurrence of muscle spindles (MS is quite high in most skeletal muscles of humans, few MS, or even absence, have been reported in digastric and mylohyoideus muscles. Even if this condition is generally accepted and quoted in many papers and books, observational studies are scarce and based on histological sections of a low number of specimens. The aim of the present study is to confirm previous data, assessing MS number in a sample of digastric and mylohyoideus muscles. We investigated 11 digastric and 6 mylohyoideus muscles from 13 donors. Muscle samples were embedded in paraffin wax, cross-sectioned in a rostrocaudal direction, and stained using haematoxylin-eosin. A mean of 5.1 ± 1.1 (range 3–7 MS was found in digastric muscles and mean of 0.5 ± 0.8 (range 0–2 in mylohyoideus muscles. A significant difference (P<0.001 was found with the control sample, confirming the correctness of the histological procedure. Our results support general belief that the absolute number of spindles is sparse in digastric and mylohyoideus muscles. External forces, such as food resistance during chewing or gravity, do not counteract jaw-opening muscles. It is conceivable that this condition gives them a limited proprioceptive importance and a reduced need for having specific receptors as MS.

  20. Human bipedalism and body-mass index.

    Science.gov (United States)

    Yi, Su Do; Noh, Jae Dong; Minnhagen, Petter; Song, Mi-Young; Chon, Tae-Soo; Kim, Beom Jun

    2017-06-16

    Body-mass index, abbreviated as BMI and given by M/H (2) with the mass M and the height H, has been widely used as a useful proxy to measure a general health status of a human individual. We generalise BMI in the form of M/H (p) and pursue to answer the question of the value of p for populations of animal species including human. We compare values of p for several different datasets for human populations with the ones obtained for other animal populations of fish, whales, and land mammals. All animal populations but humans analyzed in our work are shown to have p ≈ 3 unanimously. In contrast, human populations are different: As young infants grow to become toddlers and keep growing, the sudden change of p is observed at about one year after birth. Infants younger than one year old exhibit significantly larger value of p than two, while children between one and five years old show p ≈ 2, sharply different from other animal species. The observation implies the importance of the upright posture of human individuals. We also propose a simple mechanical model for a human body and suggest that standing and walking upright should put a clear division between bipedal human (p ≈ 2) and other animals (p ≈ 3).

  1. Mathematical human body modelling for impact loading

    NARCIS (Netherlands)

    Happee, R.; Morsink, P.L.J.; Wismans, J.S.H.M.

    1999-01-01

    Mathematical modelling of the human body is widely used for automotive crash safety research and design. Simulations have contributed to a reduction of injury numbers by optimisation of vehicle structures and restraint systems. Currently such simulations are largely performed using occupant models

  2. Visuals and Visualisation of Human Body Systems

    Science.gov (United States)

    Mathai, Sindhu; Ramadas, Jayashree

    2009-01-01

    This paper explores the role of diagrams and text in middle school students' understanding and visualisation of human body systems. We develop a common framework based on structure and function to assess students' responses across diagram and verbal modes. Visualisation is defined in terms of understanding transformations on structure and relating…

  3. Mathematical human body modelling for impact loading

    NARCIS (Netherlands)

    Happee, R.; Morsink, P.L.J.; Wismans, J.S.H.M.

    1999-01-01

    Mathematical modelling of the human body is widely used for automotive crash safety research and design. Simulations have contributed to a reduction of injury numbers by optimisation of vehicle structures and restraint systems. Currently such simulations are largely performed using occupant models b

  4. Human body modeling in injury biomechanics

    NARCIS (Netherlands)

    Happee, R.; Morsink, P.L.J.; Horst, M.J. van der; Wismans, J.S.H.M.

    1999-01-01

    Mathematical modelling is widely used for crash-safety research and design. However, most occupant models used in crash simulations are based on crash dummies and thereby inherit their apparent limitations. This paper describes a mathematical model of the real human body for impact loading. A combin

  5. IMP metabolism in human skeletal muscle after exhaustive exercise

    DEFF Research Database (Denmark)

    Tullson, P. C.; Bangsbo, Jens; Hellsten, Ylva

    1995-01-01

    This study addressed whether AMP deaminase (AMPD)myosin binding occurs with deamination during intense exercise in humans and the extent of purine loss from muscle during the initial minutes of recovery. Male subjects performed cycle exercise (265 +/- 2 W for 4.39 +/- 0.04 min) to stimulate muscle...

  6. Regression of polyneural innervation in the human psoas muscle

    NARCIS (Netherlands)

    Gramsbergen, A; IjkemaPaassen, J; Nikkels, PGJ; HaddersAlgra, M

    1997-01-01

    During the early stages of mammalian ontogeny muscle fibres are innervated by more than one axon. This polyneural innervation is replaced by mononeural innervation in the course of development. The regression of polyneural innervation in the psoas muscle in the human is the topic of the present stud

  7. Beyond muscles: unexplored parts of men's body image.

    Science.gov (United States)

    Tiggemann, Marika; Martins, Yolanda; Churchett, Libby

    2008-11-01

    Thus far the study of men's body image has been largely restricted to the dimensions of adiposity and muscularity. The aim of this study was to investigate in a systematic way multiple aspects of men's body images, in particular, head hair, body hair, height and penis size, in addition to body weight and muscularity. Questionnaires were completed online by 200 heterosexual men. It was found that men were dissatisfied with all six aspects of their bodies, and worried primarily about body weight, penis size and height. In addition, aspects of weight, muscularity, height and penis size, but not head or body hair, were related to overall appearance self-esteem. It was concluded that men's body image is both multi-faceted and complex.

  8. Reflex control of human jaw muscles.

    Science.gov (United States)

    Türker, Kemal S

    2002-01-01

    The aim of this review is to discuss what is known about the reflex control of the human masticatory system and to propose a method for standardized investigation. Literature regarding the current knowledge of activation of jaw muscles, receptors involved in the feedback control, and reflex pathways is discussed. The reflexes are discussed under the headings of the stimulation conditions. This was deliberately done to remind the reader that under each stimulation condition, several receptor systems are activated, and that it is not yet possible to stimulate only one afferent system in isolation in human mastication experiments. To achieve a method for uniform investigation, we need to set a method for stimulation of the afferent pathway under study with minimal simultaneous activation of other receptor systems. This stimulation should also be done in an efficient and reproducible way. To substantiate our conviction to standardize the stimulus type and parameters, we discuss the advantages and disadvantages of mechanical and electrical stimuli. For mechanical stimulus to be delivered in a reproducible way, the following precautions are suggested: The stimulus delivery system (often a probe attached to a vibrator) should be brought into secure contact with the area of stimulation. To minimize the slack between the probe, the area to be stimulated should be taken up by the application of pre-load, and the delivered force should be recorded in series. Electrical stimulus has advantages in that it can be delivered in a reproducible way, though its physiological relevance can be questioned. It is also necessary to standardize the method for recording and analyzing the responses of the motoneurons to the stimulation. For that, a new technique is introduced, and its advantages over the currently used methods are discussed. The new method can illustrate the synaptic potential that is induced in the motoneurons without the errors that are unavoidable in the current

  9. [Microbiota and representations of the human body].

    Science.gov (United States)

    Dodet, Betty

    2016-11-01

    Although the presence of an intestinal flora has been known for a long time, the discovery of the role of gut microbiota in human health and disease has been widely recognized as one of the most important advances in the recent years. Chronic diseases may result from dysbiosis, i.e. a disruption of the balance within the bacterial population hosted by the human body. These developments open new prospects in terms of prevention and treatment, including the design of adapted diets, the development of functional foods and fecal transplantation. These discoveries have profoundly altered our view of microbes, of health and disease, of self and non-self, as well as our representations of the body and its relationship with its ecosystem. Gut microbiota is now generally considered as an organ in its own right. A model of the "microbiotic person" thus arises, in which the human organism is defined as an ecosystem, a chimeric superorganism with a double genome, both human and microbial. Thought should be given to the way in which these new paradigms modify lay perceptions of the human body.

  10. The relationship between skeletal muscle mitochondrial citrate synthase activity and whole body oxygen uptake adaptations in response to exercise training

    DEFF Research Database (Denmark)

    Vigelsø, Andreas; Andersen, Nynne B; Dela, Flemming

    2014-01-01

    Citrate synthase (CS) activity is a validated biomarker for mitochondrial density in skeletal muscle. CS activity is also used as a biochemical marker of the skeletal muscle oxidative adaptation to a training intervention, and a relationship between changes in whole body aerobic capacity and chan......Citrate synthase (CS) activity is a validated biomarker for mitochondrial density in skeletal muscle. CS activity is also used as a biochemical marker of the skeletal muscle oxidative adaptation to a training intervention, and a relationship between changes in whole body aerobic capacity...... and changes in CS activity is often assumed. However, this relationship and absolute values of CS and maximal oxygen uptake (V.O2max) has never been assessed across different studies. A systematic PubMed search on literature published from 1983 to 2013 was performed. The search profile included: citrate......, synthase, human, skeletal, muscle, training, not electrical stimulation, not in-vitro, not rats. Studies that reported changes in CS activity and V.O2max were included. Different training types and subject populations were analyzed independently to assess correlation between relative changes in V.O2max...

  11. ATP economy of force maintenance in human tibialis anterior muscle

    DEFF Research Database (Denmark)

    Nakagawa, Yoshinao; Ratkevicius, Aivaras; Mizuno, Masao

    2005-01-01

    PURPOSE: The aim of this study was investigate ATP economy of force maintenance in the human tibialis anterior muscle during 60 s of anaerobic voluntary contraction at 50% of maximum voluntary contraction (MVC). METHODS: ATP turnover rate was evaluated using P magnetic resonance spectroscopy (P......-MRS). The total volume of ankle dorsiflexor muscles was assessed by H magnetic resonance imaging (MRI) (H-MRI), and the fiber type composition of the tibialis anterior muscle was evaluated using histochemical analysis of muscle biopsies. RESULTS: The tibialis anterior muscle occupied 59.7 +/- 0.6% (mean +/- SEM......) of the total ankle dorsiflexor muscle volume, which was 267 +/- 10 cm. Relative cross-sectional areas occupied by Type I, IIA, and IIB fibers in the tibialis anterior were 69.3 +/- 2.2, 27.4 +/- 2.76, and 3.2 +/- 1.0%, respectively. ATP economy of force maintenance did not change significantly during the 60-s...

  12. Prolonged bed rest decreases skeletal muscle and whole body protein synthesis

    Science.gov (United States)

    Ferrando, A. A.; Lane, H. W.; Stuart, C. A.; Davis-Street, J.; Wolfe, R. R.

    1996-01-01

    We sought to determine the extent to which the loss of lean body mass and nitrogen during inactivity was due to alterations in skeletal muscle protein metabolism. Six male subjects were studied during 7 days of diet stabilization and after 14 days of stimulated microgravity (-6 degrees bed rest). Nitrogen balance became more negative (P growth factor I, and testosterone values did not change. Arteriovenous model calculations based on the infusion of L-[ring-13C6]-phenylalanine in five subjects revealed a 50% decrease in muscle protein synthesis (PS; P muscle protein also decreased by 46% (P muscle PS and that this decrease is reflected in both whole body and skeletal muscle measures.

  13. The intramuscular nerve supply of the human lateral cricoarytenoid muscle.

    Science.gov (United States)

    Sanders, I; Mu, L; Wu, B L; Biller, H F

    1993-09-01

    The lateral cricoarytenoid (LCA) muscle is one of the adductors of the vocal cords; however, some investigators believe that the lateral edge of the muscle may be involved in abduction. The possibility of functionally distinct compartments within the LCA was investigated by observing the pattern of the intramuscular nerve supply. This technique has previously clearly demonstrated neural compartments in the posterior cricoarytenoid, thyroarytenoid and cricothyroid muscles. Five adult human larynges were processed by the Sihler's stain which clears all soft tissue while counterstaining the nerves. The results of our study showed that the innervation pattern of the human LCA muscle is composed of a homogenous nerve plexus localized to the middle region of the muscle. This pattern correlates with the location of motor endplates described by prior investigators. The consistent neural pattern suggests that the LCA is composed of a single neuromuscular compartment.

  14. Zebrafish models for nemaline myopathy reveal a spectrum of nemaline bodies contributing to reduced muscle function.

    Science.gov (United States)

    Sztal, Tamar E; Zhao, Mo; Williams, Caitlin; Oorschot, Viola; Parslow, Adam C; Giousoh, Aminah; Yuen, Michaela; Hall, Thomas E; Costin, Adam; Ramm, Georg; Bird, Phillip I; Busch-Nentwich, Elisabeth M; Stemple, Derek L; Currie, Peter D; Cooper, Sandra T; Laing, Nigel G; Nowak, Kristen J; Bryson-Richardson, Robert J

    2015-09-01

    Nemaline myopathy is characterized by muscle weakness and the presence of rod-like (nemaline) bodies. The genetic etiology of nemaline myopathy is becoming increasingly understood with mutations in ten genes now known to cause the disease. Despite this, the mechanism by which skeletal muscle weakness occurs remains elusive, with previous studies showing no correlation between the frequency of nemaline bodies and disease severity. To investigate the formation of nemaline bodies and their role in pathogenesis, we generated overexpression and loss-of-function zebrafish models for skeletal muscle α-actin (ACTA1) and nebulin (NEB). We identify three distinct types of nemaline bodies and visualize their formation in vivo, demonstrating these nemaline bodies not only exhibit different subcellular origins, but also have distinct pathological consequences within the skeletal muscle. One subtype is highly dynamic and upon breakdown leads to the accumulation of cytoplasmic actin contributing to muscle weakness. Examination of a Neb-deficient model suggests this mechanism may be common in nemaline myopathy. Another subtype results from a reduction of actin and forms a more stable cytoplasmic body. In contrast, the final type originates at the Z-disk and is associated with myofibrillar disorganization. Analysis of zebrafish and muscle biopsies from ACTA1 nemaline myopathy patients demonstrates that nemaline bodies also possess a different protein signature. In addition, we show that the ACTA1(D286G) mutation causes impaired actin incorporation and localization in the sarcomere. Together these data provide a novel examination of nemaline body origins and dynamics in vivo and identifies pathological changes that correlate with muscle weakness.

  15. Afferent contribution to locomotor muscle activity during unconstrained overground human walking: an analysis of triceps surae muscle fascicles

    DEFF Research Database (Denmark)

    Klint, Richard af; Cronin, Neil J.; Ishikawa, Masaki

    2010-01-01

    Plantar flexor series elasticity can be used to dissociate muscle fascicle and muscle tendon behaviour and, therefore, afferent feedback during human walking. We used electromyography (EMG) and high speed ultrasonography concomitantly to monitor muscle activity and muscle fascicle behaviour in ni...

  16. Decellularized Human Skeletal Muscle as Biologic Scaffold for Reconstructive Surgery

    Directory of Open Access Journals (Sweden)

    Andrea Porzionato

    2015-07-01

    Full Text Available Engineered skeletal muscle tissues have been proposed as potential solutions for volumetric muscle losses, and biologic scaffolds have been obtained by decellularization of animal skeletal muscles. The aim of the present work was to analyse the characteristics of a biologic scaffold obtained by decellularization of human skeletal muscles (also through comparison with rats and rabbits and to evaluate its integration capability in a rabbit model with an abdominal wall defect. Rat, rabbit and human muscle samples were alternatively decellularized with two protocols: n.1, involving sodium deoxycholate and DNase I; n.2, trypsin-EDTA and Triton X-NH4OH. Protocol 2 proved more effective, removing all cellular material and maintaining the three-dimensional networks of collagen and elastic fibers. Ultrastructural analyses with transmission and scanning electron microscopy confirmed the preservation of collagen, elastic fibres, glycosaminoglycans and proteoglycans. Implantation of human scaffolds in rabbits gave good results in terms of integration, although recellularization by muscle cells was not completely achieved. In conclusion, human skeletal muscles may be effectively decellularized to obtain scaffolds preserving the architecture of the extracellular matrix and showing mechanical properties suitable for implantation/integration. Further analyses will be necessary to verify the suitability of these scaffolds for in vitro recolonization by autologous cells before in vivo implantation.

  17. Recombinant growth hormone enhances muscle myosin heavy-chain mRNA accumulation and amino acid accrual in humans.

    OpenAIRE

    Fong, Y; M. Rosenbaum; Tracey, K J; Raman, G.; Hesse, D G; Matthews, D. E.; Leibel, R. L.; Gertner, J M; Fischman, D. A.; Lowry, S F

    1989-01-01

    A potentially lethal complication of trauma, malignancy, and infection is a progressive erosion of muscle protein mass that is not readily reversed by nutritional support. Growth hormone is capable of improving total body nitrogen balance, but its role in myofibrillar protein synthesis in humans is unknown. The acute, in situ muscle protein response to an infusion of methionyl human growth hormone was investigated in the limbs of nutritionally depleted subjects during a period of intravenous ...

  18. Human Satellite Cell Transplantation and Regeneration from Diverse Skeletal Muscles

    Directory of Open Access Journals (Sweden)

    Xiaoti Xu

    2015-09-01

    Full Text Available Identification of human satellite cells that fulfill muscle stem cell criteria is an unmet need in regenerative medicine. This hurdle limits understanding how closely muscle stem cell properties are conserved among mice and humans and hampers translational efforts in muscle regeneration. Here, we report that PAX7 satellite cells exist at a consistent frequency of 2–4 cells/mm of fiber in muscles of the human trunk, limbs, and head. Xenotransplantation into mice of 50–70 fiber-associated, or 1,000–5,000 FACS-enriched CD56+/CD29+ human satellite cells led to stable engraftment and formation of human-derived myofibers. Human cells with characteristic PAX7, CD56, and CD29 expression patterns populated the satellite cell niche beneath the basal lamina on the periphery of regenerated fibers. After additional injury, transplanted satellite cells robustly regenerated to form hundreds of human-derived fibers. Together, these findings conclusively delineate a source of bona-fide endogenous human muscle stem cells that will aid development of clinical applications.

  19. TUNING IN TO FISH SWIMMING WAVES - BODY FORM, SWIMMING MODE AND MUSCLE FUNCTION

    NARCIS (Netherlands)

    WARDLE, CS; VIDELER, JJ; ALTRINGHAM, JD

    1995-01-01

    Most fish species swim with lateral body undulations running from head to tail, These waves run more slowly than the waves of muscle activation causing them, reflecting the effect of the interaction between the fish's body and the reactive forces from the water, The coupling between both waves depen

  20. TUNING IN TO FISH SWIMMING WAVES - BODY FORM, SWIMMING MODE AND MUSCLE FUNCTION

    NARCIS (Netherlands)

    WARDLE, CS; VIDELER, JJ; ALTRINGHAM, JD

    1995-01-01

    Most fish species swim with lateral body undulations running from head to tail, These waves run more slowly than the waves of muscle activation causing them, reflecting the effect of the interaction between the fish's body and the reactive forces from the water, The coupling between both waves depen

  1. TUNING IN TO FISH SWIMMING WAVES - BODY FORM, SWIMMING MODE AND MUSCLE FUNCTION

    NARCIS (Netherlands)

    WARDLE, CS; VIDELER, JJ; ALTRINGHAM, JD

    Most fish species swim with lateral body undulations running from head to tail, These waves run more slowly than the waves of muscle activation causing them, reflecting the effect of the interaction between the fish's body and the reactive forces from the water, The coupling between both waves

  2. A general-purpose framework to simulate musculoskeletal system of human body: using a motion tracking approach.

    Science.gov (United States)

    Ehsani, Hossein; Rostami, Mostafa; Gudarzi, Mohammad

    2016-02-01

    Computation of muscle force patterns that produce specified movements of muscle-actuated dynamic models is an important and challenging problem. This problem is an undetermined one, and then a proper optimization is required to calculate muscle forces. The purpose of this paper is to develop a general model for calculating all muscle activation and force patterns in an arbitrary human body movement. For this aim, the equations of a multibody system forward dynamics, which is considered for skeletal system of the human body model, is derived using Lagrange-Euler formulation. Next, muscle contraction dynamics is added to this model and forward dynamics of an arbitrary musculoskeletal system is obtained. For optimization purpose, the obtained model is used in computed muscle control algorithm, and a closed-loop system for tracking desired motions is derived. Finally, a popular sport exercise, biceps curl, is simulated by using this algorithm and the validity of the obtained results is evaluated via EMG signals.

  3. In vivo passive mechanical behaviour of muscle fascicles and tendons in human gastrocnemius muscle-tendon units.

    Science.gov (United States)

    Herbert, Robert D; Clarke, Jillian; Kwah, Li Khim; Diong, Joanna; Martin, Josh; Clarke, Elizabeth C; Bilston, Lynne E; Gandevia, Simon C

    2011-11-01

    Ultrasound imaging was used to measure the length of muscle fascicles in human gastrocnemius muscles while the muscle was passively lengthened and shortened by moving the ankle. In some subjects the muscle belly 'buckled' at short lengths. When the gastrocnemius muscle-tendon unit was passively lengthened from its shortest in vivo length by dorsiflexing the ankle, increases in muscle-tendon length were not initially accompanied by increases in muscle fascicle lengths (fascicle length remained constant), indicating muscle fascicles were slack at short muscle-tendon lengths. The muscle-tendon length at which slack is taken up differs among fascicles: some fascicles begin to lengthen at very short muscle-tendon lengths whereas other fascicles remain slack over a large range of muscle-tendon lengths. This suggests muscle fascicles are progressively 'recruited' and contribute sequentially to muscle-tendon stiffness during passive lengthening of the muscle-tendon unit. Even above their slack lengths muscle fascicles contribute only a small part (tendon length. The contribution of muscle fascicles to muscle-tendon length increases with muscle length. The novelty of this work is that it reveals a previously unrecognised phenomenon (buckling at short lengths), posits a new mechanism of passive mechanical properties of muscle (recruitment of muscle fascicles), and confirms with high-resolution measurements that the passive compliance of human gastrocnemius muscle-tendon units is due largely to the tendon. It would be interesting to investigate if adaptations of passive properties of muscles are associated with changes in the distribution of muscle lengths at which fascicles fall slack.

  4. Morphology of muscle attachment sites in the modern human hand does not reflect muscle architecture.

    Science.gov (United States)

    Williams-Hatala, E M; Hatala, K G; Hiles, S; Rabey, K N

    2016-06-23

    Muscle attachment sites (entheses) on dry bones are regularly used by paleontologists to infer soft tissue anatomy and to reconstruct behaviors of extinct organisms. This method is commonly applied to fossil hominin hand bones to assess their abilities to participate in Paleolithic stone tool behaviors. Little is known, however, about how or even whether muscle anatomy and activity regimes influence the morphologies of their entheses, especially in the hand. Using the opponens muscles from a sample of modern humans, we tested the hypothesis that aspects of hand muscle architecture that are known to be influenced by behavior correlate with the size and shape of their associated entheses. Results show no consistent relationships between these behaviorally-influenced aspects of muscle architecture and entheseal morphology. Consequently, it is likely premature to infer patterns of behavior, such as stone tool making in fossil hominins, from these same entheses.

  5. Muscle specific microRNAs are regulated by endurance exercise in human skeletal muscle

    DEFF Research Database (Denmark)

    Nielsen, Søren; Scheele, Camilla; Yfanti, Christina;

    2010-01-01

    of all four myomiRs (P training expression levels 14 days after ceasing the training programme. Components of major pathways involved in endurance adaptation such as MAPK and TGF-ß were predicted to be targeted by the myomiRs examined. Tested......, but their role in regulating human skeletal muscle adaptation remains unknown.......Muscle specific miRNAs, myomiRs, have been shown to control muscle development in vitro and are differentially expressed at rest in diabetic skeletal muscle. Therefore, we investigated the expression of these myomiRs, including miR-1, miR-133a, miR-133b and miR-206 in muscle biopsies from vastus...

  6. Identification and characterization of uncoupling protein 4 in fat body and muscle mitochondria from the cockroach Gromphadorhina cocquereliana.

    Science.gov (United States)

    Slocinska, Malgorzata; Antos-Krzeminska, Nina; Rosinski, Grzegorz; Jarmuszkiewicz, Wieslawa

    2011-12-01

    We have identified and characterized an uncoupling protein in mitochondria isolated from leg muscle and from fat body, an insect analogue tissue of mammalian liver and adipose tissue, of the cockroach Gromphadorhina coquereliana (GcUCP). This is the first functional characterization of UCP activity in isolated insect mitochondria. Bioenergetic studies clearly indicate UCP function in both insect tissues. In resting (non-phosphorylating) mitochondria, cockroach GcUCP activity was stimulated by the addition of micromolar concentrations of palmitic acid and inhibited by the purine nucleotide GTP. Moreover, in phosphorylating mitochondria, GcUCP activity was able to divert energy from oxidative phosphorylation. Functional studies indicate a higher activity of GcUCP-mediated uncoupling in cockroach muscle mitochondria compared to fat body mitochondria. GcUCP activation by palmitic acid resulted in a decrease in superoxide anion production, suggesting that protection against mitochondrial oxidative stress may be a physiological role of UCPs in insects. GcUCP protein was immunodetected using antibodies raised against human UCP4 as a single band of around 36 kDa. GcUCP protein expression in cockroach muscle mitochondria was significantly higher compared to mitochondria isolated from fat body. LC-MS/MS analyses revealed 100% sequence identities for peptides obtained from GcUCP to UCP4 isoforms from D. melanogaster (the highest homology), human, rat or other insect mitochondria. Therefore, it can be proposed that cockroach GcUCP corresponds to the UCP4 isoforms of other animals.

  7. Effect of exercise on insulin action in human skeletal muscle

    DEFF Research Database (Denmark)

    Richter, Erik; Mikines, K J; Galbo, Henrik

    1989-01-01

    The effect of 1 h of dynamic one-legged exercise on insulin action in human muscle was studied in 6 healthy young men. Four hours after one-legged knee extensions, a three-step sequential euglycemic hyperinsulinemic clamp combined with arterial and bilateral femoral vein catheterization was perfo...... recovery of human skeletal muscle.......The effect of 1 h of dynamic one-legged exercise on insulin action in human muscle was studied in 6 healthy young men. Four hours after one-legged knee extensions, a three-step sequential euglycemic hyperinsulinemic clamp combined with arterial and bilateral femoral vein catheterization...... consumption and at some insulin concentrations on potassium exchange. In contrast, no change in insulin effects on limb exchange of free fatty acids, glycerol, alanine or tyrosine were found after exercise. Glycogen concentration in rested vastus lateralis muscle did not increase measurably during the clamp...

  8. [An interactive three-dimensional model of the human body].

    Science.gov (United States)

    Liem, S L

    2009-01-01

    Driven by advanced computer technology, it is now possible to show the human anatomy on a computer. On the internet, the Visible Body programme makes it possible to navigate in all directions through the anatomical structures of the human body, using mouse and keyboard. Visible Body is a wonderful tool to give insight in the human structures, body functions and organs.

  9. Prolonged bed rest decreases skeletal muscle and whole body protein synthesis

    Science.gov (United States)

    Ferrando, A. A.; Lane, H. W.; Stuart, C. A.; Davis-Street, J.; Wolfe, R. R.

    1996-01-01

    We sought to determine the extent to which the loss of lean body mass and nitrogen during inactivity was due to alterations in skeletal muscle protein metabolism. Six male subjects were studied during 7 days of diet stabilization and after 14 days of stimulated microgravity (-6 degrees bed rest). Nitrogen balance became more negative (P protein synthesis (PS; P protein also decreased by 46% (P protein breakdown and inward transport. Whole body protein synthesis determined by [15N]alanine ingestion on six subjects also revealed a 14% decrease (P protein breakdown change significantly. These results indicate that the loss of body protein with inactivity is predominantly due to a decrease in muscle PS and that this decrease is reflected in both whole body and skeletal muscle measures.

  10. Intramuscular architecture of the autochthonous back muscles in humans.

    Science.gov (United States)

    Stark, Heiko; Fröber, Rosemarie; Schilling, Nadja

    2013-02-01

    Many training concepts take muscle properties such as contraction speed or muscle topography into account to achieve an optimal training outcome. Thus far, the internal architecture of muscles has largely been neglected, although it is well known that parameters such as pennation angles or the lengths of fascicles but also the proportions of fleshy and tendinous fascicle parts have a major impact on the contraction behaviour of a muscle. Here, we present the most detailed description of the intramuscular fascicle architecture of the human perivertebral muscles available so far. For this, one adult male cadaver was studied. Our general approach was to digitize the geometry of each fascicle of the muscles of back proper (Erector spinae) - the Spinalis thoracis, Iliocostalis lumborum, Longissimus thoracis and the Multifidus thoracis et lumborum - and of the deep muscles of the abdomen - Psoas minor, Psoas major and Quadratus lumborum - during a layerwise dissection. Architectural parameters such as fascicle angles to the sagittal and the frontal planes as well as fascicle lengths were determined for each fascicle, and are discussed regarding their consequences for the function of the muscle. For example, compared with the other dorsovertebral muscles, the Longissimus thoracis can produce greater shortening distances because of its relatively long fleshy portions, and it can store more elastic energy due to both its relatively long fleshy and tendinous fascicle portions. The Quadratus lumborum was outstanding because of its many architectural subunits defined by distinct attachment sites and fascicle lengths. The presented database will improve biomechanical models of the human trunk by allowing the incorporation of anisotropic muscle properties such as the fascicle direction into finite element models. This information will help to increase our understanding of the functionality of the human back musculature, and may thereby improve future training concepts.

  11. Shared muscle synergies in human walking and cycling.

    Science.gov (United States)

    Barroso, Filipe O; Torricelli, Diego; Moreno, Juan C; Taylor, Julian; Gomez-Soriano, Julio; Bravo-Esteban, Elisabeth; Piazza, Stefano; Santos, Cristina; Pons, José L

    2014-10-15

    The motor system may rely on a modular organization (muscle synergies activated in time) to execute different tasks. We investigated the common control features of walking and cycling in healthy humans from the perspective of muscle synergies. Three hypotheses were tested: 1) muscle synergies extracted from walking trials are similar to those extracted during cycling; 2) muscle synergies extracted from one of these motor tasks can be used to mathematically reconstruct the electromyographic (EMG) patterns of the other task; 3) muscle synergies of cycling can result from merging synergies of walking. A secondary objective was to identify the speed (and cadence) at which higher similarities emerged. EMG activity from eight muscles of the dominant leg was recorded in eight healthy subjects during walking and cycling at four matched cadences. A factorization technique [nonnegative matrix factorization (NNMF)] was applied to extract individual muscle synergy vectors and the respective activation coefficients behind the global muscular activity of each condition. Results corroborated hypotheses 2 and 3, showing that 1) four synergies from walking and cycling can successfully explain most of the EMG variability of cycling and walking, respectively, and 2) two of four synergies from walking appear to merge together to reconstruct one individual synergy of cycling, with best reconstruction values found for higher speeds. Direct comparison of the muscle synergy vectors of walking and the muscle synergy vectors of cycling (hypothesis 1) produced moderated values of similarity. This study provides supporting evidence for the hypothesis that cycling and walking share common neuromuscular mechanisms.

  12. Small-bodied humans from Palau, Micronesia.

    Directory of Open Access Journals (Sweden)

    Lee R Berger

    Full Text Available UNLABELLED: Newly discovered fossil assemblages of small bodied Homo sapiens from Palau, Micronesia possess characters thought to be taxonomically primitive for the genus Homo. BACKGROUND: Recent surface collection and test excavation in limestone caves in the rock islands of Palau, Micronesia, has produced a sizeable sample of human skeletal remains dating roughly between 940-2890 cal ybp. PRINCIPLE FINDINGS: Preliminary analysis indicates that this material is important for two reasons. First, individuals from the older time horizons are small in body size even relative to "pygmoid" populations from Southeast Asia and Indonesia, and thus may represent a marked case of human insular dwarfism. Second, while possessing a number of derived features that align them with Homo sapiens, the human remains from Palau also exhibit several skeletal traits that are considered to be primitive for the genus Homo. SIGNIFICANCE: These features may be previously unrecognized developmental correlates of small body size and, if so, they may have important implications for interpreting the taxonomic affinities of fossil specimens of Homo.

  13. The Body Action Coding System II: Muscle activations during the perception and expression of emotion

    Directory of Open Access Journals (Sweden)

    Elisabeth M.J. Huis in 't Veld

    2014-09-01

    Full Text Available Research into the expression and perception of emotions has mostly focused on facial expressions. Recently, body postures have become increasingly important in research, but knowledge on muscle activity during the perception or expression of emotion is lacking. The current study continues the development of a Body Action Coding System (BACS, which was initiated in a previous study, and described the involvement of muscles in the neck, shoulders and arms during expression of fear and anger. The current study expands the BACS by assessing the activity patterns of three additional muscles. Surface electromyography of muscles in the neck (upper trapezius descendens, forearms (extensor carpi ulnaris, lower back (erector spinae longissimus and calves (peroneus longus were measured during active expression and passive viewing of fearful and angry body expressions. The muscles in the forearm were strongly active for anger expression and to a lesser extent for fear expression. In contrast, muscles in the calves were recruited slightly more for fearful expressions. It was also found that muscles automatically responded to the perception of emotion, without any overt movement. The observer’s forearms responded to the perception of fear, while the muscles used for leaning backwards were activated when faced with an angry adversary. Lastly, the calf responded immediately when a fearful person was seen, but responded slower to anger. There is increasing interest in developing systems that are able to create or recognize emotional body language for the development of avatars, robots, and online environments. To that end, multiple coding systems have been developed that can either interpret or create bodily expressions based on static postures, motion capture data or videos. However, the BACS is the first coding system based on muscle activity.

  14. The Body Action Coding System II: muscle activations during the perception and expression of emotion.

    Science.gov (United States)

    Huis In 't Veld, Elisabeth M J; van Boxtel, Geert J M; de Gelder, Beatrice

    2014-01-01

    Research into the expression and perception of emotions has mostly focused on facial expressions. Recently, body postures have become increasingly important in research, but knowledge on muscle activity during the perception or expression of emotion is lacking. The current study continues the development of a Body Action Coding System (BACS), which was initiated in a previous study, and described the involvement of muscles in the neck, shoulders and arms during expression of fear and anger. The current study expands the BACS by assessing the activity patterns of three additional muscles. Surface electromyography of muscles in the neck (upper trapezius descendens), forearms (extensor carpi ulnaris), lower back (erector spinae longissimus) and calves (peroneus longus) were measured during active expression and passive viewing of fearful and angry body expressions. The muscles in the forearm were strongly active for anger expression and to a lesser extent for fear expression. In contrast, muscles in the calves were recruited slightly more for fearful expressions. It was also found that muscles automatically responded to the perception of emotion, without any overt movement. The observer's forearms responded to the perception of fear, while the muscles used for leaning backwards were activated when faced with an angry adversary. Lastly, the calf responded immediately when a fearful person was seen, but responded slower to anger. There is increasing interest in developing systems that are able to create or recognize emotional body language for the development of avatars, robots, and online environments. To that end, multiple coding systems have been developed that can either interpret or create bodily expressions based on static postures, motion capture data or videos. However, the BACS is the first coding system based on muscle activity.

  15. Physical function and muscle strength in sporadic inclusion body myositis

    DEFF Research Database (Denmark)

    Jørgensen, Anders N; Aagaard, Per; Nielsen, Jakob L

    2017-01-01

    chair stand performance were evaluated. In addition, patients were tested for knee extensor muscle strength (isokinetic dynamometer) and leg extension power (Nottingham power rig). RESULTS: TUG performance was the strongest predictor of self-reported physical function (r(2) = 0.56, P ... extension strength and between-limb strength asymmetry were the strongest multi-regression indicators of TUG performance (r(2) = 0.51, P 2) = 0.49, P

  16. Preliminary observations on the microarchitecture of the human abdominal muscles.

    Science.gov (United States)

    Woodley, Stephanie J; Duxson, Marilyn J; Mercer, Susan R

    2007-10-01

    Precise knowledge of muscle architecture and innervation patterns is essential for the development of accurate clinical and biomechanical models. Although the gross anatomy of the human abdominal muscles has been investigated, the finer details of their microanatomy are not well described. Fascicles were systematically sampled from each of the human abdominal muscles, and small fiber bundles from selected fascicles stained with acetylcholinesterase to determine the location of motor endplate bands, myomyonal junctions, and myotendinous junctions. Statistical analysis was used to ascertain the association between fascicular length and number of endplate bands. The number of endplate bands along a fascicle was variable between different portions of each muscle, but was strongly correlated with fascicular length (r = 0.814). In fascicles less than 50 millimeters (mm) in length, only a single endplate band was generally present, while multiple endplate bands (usually two or three) were found in fascicles longer than 50 mm. The presence of myomyonal junctions throughout the longer (>50 mm) fascicles verified that they were composed of short, intrafascicularly terminating fibers, while shorter fascicles comprised fibers spanning the entire fascicular length. This preliminary study provides evidence that multiple endplate bands are contained in some regions of the abdominal muscles, an arrangement that differs from most human appendicular muscles. It is not clear whether the variations in the described fine architectural features reflect regional differences in muscle function.

  17. Expiratory muscle loading increases intercostal muscle blood flow during leg exercise in healthy humans

    Science.gov (United States)

    Athanasopoulos, Dimitris; Louvaris, Zafeiris; Cherouveim, Evgenia; Andrianopoulos, Vasilis; Roussos, Charis; Zakynthinos, Spyros

    2010-01-01

    We investigated whether expiratory muscle loading induced by the application of expiratory flow limitation (EFL) during exercise in healthy subjects causes a reduction in quadriceps muscle blood flow in favor of the blood flow to the intercostal muscles. We hypothesized that, during exercise with EFL quadriceps muscle blood flow would be reduced, whereas intercostal muscle blood flow would be increased compared with exercise without EFL. We initially performed an incremental exercise test on eight healthy male subjects with a Starling resistor in the expiratory line limiting expiratory flow to ∼ 1 l/s to determine peak EFL exercise workload. On a different day, two constant-load exercise trials were performed in a balanced ordering sequence, during which subjects exercised with or without EFL at peak EFL exercise workload for 6 min. Intercostal (probe over the 7th intercostal space) and vastus lateralis muscle blood flow index (BFI) was calculated by near-infrared spectroscopy using indocyanine green, whereas cardiac output (CO) was measured by an impedance cardiography technique. At exercise termination, CO and stroke volume were not significantly different during exercise, with or without EFL (CO: 16.5 vs. 15.2 l/min, stroke volume: 104 vs. 107 ml/beat). Quadriceps muscle BFI during exercise with EFL (5.4 nM/s) was significantly (P = 0.043) lower compared with exercise without EFL (7.6 nM/s), whereas intercostal muscle BFI during exercise with EFL (3.5 nM/s) was significantly (P = 0.021) greater compared with that recorded during control exercise (0.4 nM/s). In conclusion, increased respiratory muscle loading during exercise in healthy humans causes an increase in blood flow to the intercostal muscles and a concomitant decrease in quadriceps muscle blood flow. PMID:20507965

  18. Muscle activity and acceleration during whole body vibration: effect of frequency and amplitude.

    Science.gov (United States)

    Pollock, Ross D; Woledge, Roger C; Mills, Kerry R; Martin, Finbarr C; Newham, Di J

    2010-10-01

    Whole body vibration may improve muscle and bone strength, power and balance although contradictory findings have been reported. Prolonged exposure may result in adverse effects. We investigated the effects of high (5.5 mm) and low (2.5mm) amplitude whole body vibration at various frequencies (5-30 Hz) on muscle activity and acceleration throughout the body. Surface electromyographic activity was recorded from 6 leg muscles in 12 healthy adults (aged 31.3 (SD 12.4) years). The average rectified acceleration of the toe, ankle, knee, hip and head was recorded from 15 healthy adults (36 (SD 12.1) years) using 3D motion analysis. Whole body vibration increased muscle activity 5-50% of maximal voluntary contraction with the greatest increase in the lower leg. Activity was greater with high amplitude at all frequencies, however this was not always significant (P 15 Hz acceleration decreased with distance from the platform. This was associated with increased muscle activity, presumably due to postural control and muscle tuning mechanisms. The minimal acceleration at the head reduces the likelihood of adverse reactions. The levels of activation are unlikely to cause hypertrophy in young healthy individuals but may be sufficient in weak and frail people. 2010 Elsevier Ltd. All rights reserved.

  19. Interplay between body stabilisation and quadriceps muscle activation capacity.

    Science.gov (United States)

    Bampouras, Theodoros M; Reeves, Neil D; Baltzopoulos, Vasilios; Maganaris, Constantinos N

    2017-03-22

    The study aimed to distinguish the effect of stabilisation and muscle activation on quadriceps maximal isometric voluntary contraction (MVC) torque generation. Nine subjects performed (a) an MVC with restrained leg and pelvis (Typical MVC), (b) a Typical MVC with handgrip (Handgrip MVC), (c) an MVC focusing on contracting the knee extensors only (Isolated knee extension MVC), and (d) an MVC with unrestrained leg and pelvis (Unrestrained MVC). Torque and activation capacity between conditions were compared with repeated measures ANOVA and dependent t-tests. EMG (from eleven remote muscles) was compared using Friedman's and Wilcoxon. Typical MVC (277.2±49.6Nm) and Handgrip MVC (261.0±55.4Nm) were higher than Isolated knee extension MVC (210.2±48.3Nm, pMVC (195.2±49.7Nm, pMVC (83.1±15.9%) activation was higher than Isolated knee extension MVC (68.9±24.3%, pMVC and Handgrip MVC (81.8±17.4%) were higher than Unrestrained MVC (64.9±16.2%, pMVC consistently lower than Typical MVC or Handgrip MVC. Stabilisation of the involved segments is the prime concern allowing fuller activation of the muscle, reinforcing the need for close attention to stabilisation during dynamometry-based knee joint functional assessment.

  20. Muscle biopsies from human muscle diseases with myopathic pathology reveal common alterations in mitochondrial function.

    Science.gov (United States)

    Sunitha, Balaraju; Gayathri, Narayanappa; Kumar, Manish; Keshava Prasad, Thottethodi Subrahmanya; Nalini, Atchayaram; Padmanabhan, Balasundaram; Srinivas Bharath, Muchukunte Mukunda

    2016-07-01

    Muscle diseases are clinically and genetically heterogeneous and manifest as dystrophic, inflammatory and myopathic pathologies, among others. Our previous study on the cardiotoxin mouse model of myodegeneration and inflammation linked muscle pathology with mitochondrial damage and oxidative stress. In this study, we investigated whether human muscle diseases display mitochondrial changes. Muscle biopsies from muscle disease patients, represented by dysferlinopathy (dysfy) (dystrophic pathology; n = 43), polymyositis (PM) (inflammatory pathology; n = 24), and distal myopathy with rimmed vacuoles (DMRV) (distal myopathy; n = 31) were analyzed. Mitochondrial damage (ragged blue and COX-deficient fibers) was revealed in dysfy, PM, and DMRV cases by enzyme histochemistry (SDH and COX-SDH), electron microscopy (vacuolation and altered cristae) and biochemical assays (significantly increased ADP/ATP ratio). Proteomic analysis of muscle mitochondria from all three muscle diseases by isobaric tag for relative and absolute quantitation labeling and liquid chromatography-tandem mass spectrometry (LC-MS/MS) analysis demonstrated down-regulation of electron transport chain (ETC) complex subunits, assembly factors and Krebs cycle enzymes. Interestingly, 80 of the under-expressed proteins were common among the three pathologies. Assay of ETC and Krebs cycle enzyme activities validated the MS data. Mitochondrial proteins from muscle pathologies also displayed higher tryptophan (Trp) oxidation and the same was corroborated in the cardiotoxin model. Molecular modeling predicted Trp oxidation to alter the local structure of mitochondrial proteins. Our data highlight mitochondrial alterations in muscle pathologies, represented by morphological changes, altered mitochondrial proteome and protein oxidation, thereby establishing the role of mitochondrial damage in human muscle diseases. We investigated whether human muscle diseases display mitochondrial changes. Muscle biopsies

  1. Muscle function and body composition profile in adolescents with restrictive anorexia nervosa: does resistance training help?

    Science.gov (United States)

    Fernández-del-Valle, Maria; Larumbe-Zabala, Eneko; Morande-Lavin, Gonzalo; Perez Ruiz, Margarita

    2016-01-01

    The aim of this study was to analyze the effects of short-term resistance training on the body composition profile and muscle function in a group of Anorexia Nervosa restricting type (AN-R) patients. The sample consisted of AN-R female adolescents (12.8 ± 0.6 years) allocated into the control and intervention groups (n = 18 each). Body composition and relative strength were assessed at baseline, after 8 weeks and 4 weeks following the intervention. Body mass index (BMI) increased throughout the study (p = 0.011). Significant skeletal muscle mass (SMM) gains were found in the intervention group (p = 0.045, d = 0.6) that correlated to the change in BMI (r = 0.51, p  0.60) with change in BMI in both the groups. Significant relative strength increases (p strength when resistance training is prescribed. Although FM, relative body fat (%BF), BMI and body weight (BW) are used to monitor nutritional progress. Based on our results, we suggest to monitor SMM and relative strength ratios for a better estimation of body composition profile and muscle function recovery. Implications for Rehabilitation Anorexia Nervosa Restricting Type (AN-R) AN-R is a psychiatric disorder that has a major impact on muscle mass content and function. However, little or no attention has been paid to muscle recovery. High intensity resistance training is safe for AN-R after hospitalization and enhances the force generating capacity as well as muscle mass gains. Skeletal muscle mass content and muscular function improvements are partially maintained for a short period of time when the exercise program ceases.

  2. Computation of trunk muscle forces, spinal loads and stability in whole-body vibration

    Science.gov (United States)

    Bazrgari, B.; Shirazi-Adl, A.; Kasra, M.

    2008-12-01

    Whole-body vibration has been indicated as a risk factor in back disorders. Proper prevention and treatment management, however, requires a sound knowledge of associated muscle forces and loads on the spine. Previous trunk model studies have either neglected or over-simplified the trunk redundancy with time-varying unknown muscle forces. Trunk stability has neither been addressed. A novel iterative dynamic kinematics-driven approach was employed to evaluate muscle forces, spinal loads and system stability in a seated subject under a random vertical base excitation with ˜±1 g peak acceleration contents. This iterative approach satisfied equations of motion in all directions/levels while accounting for the nonlinear passive resistance of the ligamentous spine. The effect of posture, co-activity in abdominal muscles and changes in buttocks stiffness were also investigated. The computed vertical accelerations were in good agreement with measurements. The input base excitation, via inertial and muscle forces, substantially influenced spinal loads and system stability. The flexed posture in sitting increased the net moment, muscle forces and passive spinal loads while improving the trunk stability. Similarly, the introduction of low to moderate antagonistic coactivity in abdominal muscles increased the passive spinal loads and improved the spinal stability. A trade-off, hence, exists between lower muscle forces and spinal loads on one hand and more stable spine on the other. Base excitations with larger peak acceleration contents substantially increase muscle forces/spinal loads and, hence, the risk of injury.

  3. Body size and countermovement depth confound relationship between muscle power output and jumping performance

    Science.gov (United States)

    Markovic, Srdjan; Dragan, Mirkov; Nedeljkovic, Aleksandar; Jaric, Slobodan

    2013-01-01

    A number of studies based on maximum vertical jumps have presumed that the maximum jump height reveals the maximum power of lower limb muscles, as well as the tested muscle power output predicts the jumping performance. The objective of the study was to test the hypothesis that both the body size and countermovement depth confound the relationship between the muscle power output and performance of maximum vertical jumps. Sixty young and physically active males were tested on the maximum countermovement (CMJ) and squat jumps (SJ). The jumping performance (Hmax), peak (Ppeak) and the average power output (Pavg) during the concentric phase, countermovement depth (only in CMJ) and body mass as an index of body size were assessed. To assess the power-performance relationship, the correlations between Hmax with both Ppeak and Pavg were calculated without and with controlling for the effects of body mass, as well as for the countermovement depth. The results revealed moderate power-performance relationships (range 0.55body mass, the same values were markedly higher (0.61body mass and countermovement depth, CMJ revealed r=0.88 and r=0.77 for Ppeak and Pavg, respectively. Both jumps revealed stronger relationships with Ppeak than with Pavg (p<0.05) when controlled for either body mass or both body mass and countermovement depth. We conclude that both body size (in CMJ and SJ) and countermovement depth (in CMJ) confound the relationship between the muscle power output with the performance of maximum vertical jumps. Regarding routine assessments of muscle power from jumping performance and vice versa, the use of CMJ is recommended, while Ppeak, rather than Pavg, should be the variable of choice. PMID:24280557

  4. Peak muscle perfusion and oxygen uptake in humans: importance of precise estimates of muscle mass.

    Science.gov (United States)

    Râdegran, G; Blomstrand, E; Saltin, B

    1999-12-01

    The knee extensor exercise model was specifically developed to enable in vivo estimates of peak muscle blood flow and O(2) uptake in humans. The original finding, using thermodilution measurements to measure blood flow in relation to muscle mass [P. Andersen and B. Saltin. J. Physiol. (Lond.) 366: 233-249, 1985], was questioned, however, as the measurements were two- to threefold higher than those previously obtained with the (133)Xe clearance and the plethysmography technique. As thermodilution measurements have now been confirmed by other methods and independent research groups, we aimed to address the impact of muscle mass estimates on the peak values of muscle perfusion and O(2) uptake. In the present study, knee extensor volume was determined from multiple measurements with computer tomography along the full length of the muscle. In nine healthy humans, quadriceps muscle volume was 2.36 +/- 0.17 (range 1. 31-3.27) liters, corresponding to 2.48 +/- 0.18 (range 1.37-3.43) kg. Anthropometry overestimated the muscle volume by approximately 21-46%, depending on whether quadriceps muscle length was estimated from the patella to either the pubic bone, inguinal ligament, or spina iliaca anterior superior. One-legged, dynamic knee extensor exercise up to peak effort of 67 +/- 7 (range 55-100) W rendered peak values for leg blood flow (thermodilution) of 5.99 +/- 0.66 (range 4.15-9.52) l/min and leg O(2) uptake of 856 +/- 109 (range 590-1,521) ml/min. Muscle perfusion and O(2) uptake reached peak values of 246 +/- 24 (range 149-373) and 35.2 +/- 3.7 (range 22.6-59. 6) ml. min(-1). 100 g muscle(-1), respectively. These peak values are approximately 19-33% larger than those attained by applying anthropometric muscle mass estimates. In conclusion, the present findings emphasize that peak perfusion and O(2) uptake in human skeletal muscle may be up to approximately 30% higher than previous anthropometric-based estimates that use equivalent techniques for blood flow

  5. Increased Plin2 Expression in Human Skeletal Muscle Is Associated with Sarcopenia and Muscle Weakness

    Science.gov (United States)

    Conte, Maria; Vasuri, Francesco; Trisolino, Giovanni; Bellavista, Elena; Santoro, Aurelia; Degiovanni, Alessio; Martucci, Ermanno; D’Errico-Grigioni, Antonia; Caporossi, Daniela; Capri, Miriam; Maier, Andrea B.; Seynnes, Olivier; Barberi, Laura; Musarò, Antonio; Narici, Marco V.; Franceschi, Claudio; Salvioli, Stefano

    2013-01-01

    Human aging is associated with a progressive loss of muscle mass and strength and a concomitant fat accumulation in form of inter-muscular adipose tissue, causing skeletal muscle function decline and immobilization. Fat accumulation can also occur as intra-muscular triglycerides (IMTG) deposition in lipid droplets, which are associated with perilipin proteins, such as Perilipin2 (Plin2). It is not known whether Plin2 expression changes with age and if this has consequences on muscle mass and strength. We studied the expression of Plin2 in the vastus lateralis (VL) muscle of both healthy subjects and patients affected by lower limb mobility limitation of different age. We found that Plin2 expression increases with age, this phenomenon being particularly evident in patients. Moreover, Plin2 expression is inversely correlated with quadriceps strength and VL thickness. To investigate the molecular mechanisms underpinning this phenomenon, we focused on IGF-1/p53 network/signalling pathway, involved in muscle physiology. We found that Plin2 expression strongly correlates with increased p53 activation and reduced IGF-1 expression. To confirm these observations made on humans, we studied mice overexpressing muscle-specific IGF-1, which are protected from sarcopenia. These mice resulted almost negative for the expression of Plin2 and p53 at two years of age. We conclude that fat deposition within skeletal muscle in form of Plin2-coated lipid droplets increases with age and is associated with decreased muscle strength and thickness, likely through an IGF-1- and p53-dependent mechanism. The data also suggest that excessive intramuscular fat accumulation could be the initial trigger for p53 activation and consequent loss of muscle mass and strength. PMID:23977392

  6. Increased Plin2 expression in human skeletal muscle is associated with sarcopenia and muscle weakness.

    Directory of Open Access Journals (Sweden)

    Maria Conte

    Full Text Available Human aging is associated with a progressive loss of muscle mass and strength and a concomitant fat accumulation in form of inter-muscular adipose tissue, causing skeletal muscle function decline and immobilization. Fat accumulation can also occur as intra-muscular triglycerides (IMTG deposition in lipid droplets, which are associated with perilipin proteins, such as Perilipin2 (Plin2. It is not known whether Plin2 expression changes with age and if this has consequences on muscle mass and strength. We studied the expression of Plin2 in the vastus lateralis (VL muscle of both healthy subjects and patients affected by lower limb mobility limitation of different age. We found that Plin2 expression increases with age, this phenomenon being particularly evident in patients. Moreover, Plin2 expression is inversely correlated with quadriceps strength and VL thickness. To investigate the molecular mechanisms underpinning this phenomenon, we focused on IGF-1/p53 network/signalling pathway, involved in muscle physiology. We found that Plin2 expression strongly correlates with increased p53 activation and reduced IGF-1 expression. To confirm these observations made on humans, we studied mice overexpressing muscle-specific IGF-1, which are protected from sarcopenia. These mice resulted almost negative for the expression of Plin2 and p53 at two years of age. We conclude that fat deposition within skeletal muscle in form of Plin2-coated lipid droplets increases with age and is associated with decreased muscle strength and thickness, likely through an IGF-1- and p53-dependent mechanism. The data also suggest that excessive intramuscular fat accumulation could be the initial trigger for p53 activation and consequent loss of muscle mass and strength.

  7. The relationships among jaw-muscle fiber architecture, jaw morphology, and feeding behavior in extant apes and modern humans.

    Science.gov (United States)

    Taylor, Andrea B; Vinyard, Christopher J

    2013-05-01

    The jaw-closing muscles are responsible for generating many of the forces and movements associated with feeding. Muscle physiologic cross-sectional area (PCSA) and fiber length are two architectural parameters that heavily influence muscle function. While there have been numerous comparative studies of hominoid and hominin craniodental and mandibular morphology, little is known about hominoid jaw-muscle fiber architecture. We present novel data on masseter and temporalis internal muscle architecture for small- and large-bodied hominoids. Hominoid scaling patterns are evaluated and compared with representative New- (Cebus) and Old-World (Macaca) monkeys. Variation in hominoid jaw-muscle fiber architecture is related to both absolute size and allometry. PCSAs scale close to isometry relative to jaw length in anthropoids, but likely with positive allometry in hominoids. Thus, large-bodied apes may be capable of generating both absolutely and relatively greater muscle forces compared with smaller-bodied apes and monkeys. Compared with extant apes, modern humans exhibit a reduction in masseter PCSA relative to condyle-M1 length but retain relatively long fibers, suggesting humans may have sacrificed relative masseter muscle force during chewing without appreciably altering muscle excursion/contraction velocity. Lastly, craniometric estimates of PCSAs underestimate hominoid masseter and temporalis PCSAs by more than 50% in gorillas, and overestimate masseter PCSA by as much as 30% in humans. These findings underscore the difficulty of accurately estimating jaw-muscle fiber architecture from craniometric measures and suggest models of fossil hominin and hominoid bite forces will be improved by incorporating architectural data in estimating jaw-muscle forces.

  8. Regenerating human muscle fibres express GLUT3 protein

    DEFF Research Database (Denmark)

    Gaster, M; Beck-Nielsen, H; Schrøder, H D

    2002-01-01

    The presence of the GLUT3 glucose transporter protein in human muscle cells is a matter of debate. The present study was designed to establish whether GLUT3 is expressed in mature human skeletal muscle fibres and, if so, whether its expression changes under different conditions, such as metabolic...... stress (obesity, obese non-insulin-dependent diabetes mellitus), hypertrophy (training), de- and reinnervation (amyotrophic lateral sclerosis) or regeneration (polymyositis). We used an immunohistochemical approach to detect and localise GLUT3. GLUT3 immunoreactivity was not detectable in adult skeletal...... muscle fibres, nor did metabolic stress, training or de- and re-innervation induce GLUT3 expression, while a few GLUT3 expressing fibres were seen in some cases of polymyositis. In contrast, GLUT4 was expressed in all investigated muscle fibres. GLUT3 immunoreactivity was found in perineural...

  9. INFLUENCE OF UPPER-BODY EXERCISE ORDER ON MUSCLE DAMAGE IN UNTRAINED MEN

    Directory of Open Access Journals (Sweden)

    Kazem Sotoode

    2013-10-01

    Full Text Available Aim : The purpose of this study was to examine acute muscle damage after different sequences of an upper-body resistance exercise session. Methods : Twelve untrained men completed two sessions (three sets; 80% one repetition maximum; two min passive rest between sets of the same exercises in opposite sequences (larger to smaller vs. smaller to larger muscle group exercises. For each session, serum creatine kinase (CK concentrations were measured before exercise (pre and 24, 48 hours after each sequence (24P, 48P. Results: Within sequence (larger to smaller muscle-group exercises, significant differences in CK concentrations were demonstrated between most time points (P0.05. Conclusion: These results suggest that muscle damage was similar between sequences (larger to smaller vs. smaller to larger muscle-group exercises.

  10. Glutamine attenuates post-traumatic glutathione depletion in human muscle.

    Science.gov (United States)

    Fläring, U B; Rooyackers, O E; Wernerman, J; Hammarqvist, F

    2003-03-01

    Glutathione is quantitatively the most important endogenous scavenger system. Glutathione depletion in skeletal muscle is pronounced following major trauma and sepsis in intensive care unit patients. Also, following elective surgery, glutathione depletion occurs in parallel with a progressive decline in muscle glutamine concentration. The present study was designed to test the hypothesis that glutamine supplementation may counteract glutathione depletion in a human trauma model. A homogeneous group of patients (n = 17) undergoing a standardized surgical procedure were prospectively randomly allocated to receive glutamine (0.56 g x day(-1) x kg(-1)) or placebo as part of isonitrogenous and isocaloric nutrition. Percutaneous muscle biopsies and blood samples were taken pre-operatively and at 24 and 72 h after surgery. The concentrations of muscle glutathione and related amino acids were determined in muscle tissue and plasma. In the control (unsupplemented) subjects, total muscle glutathione had decreased by 47+/-8% and 37+/-11% and reduced glutathione had decreased by 53+/-10% and 45+/-16% respectively at 24 and 72 h after surgery (P glutamine supplementation attenuates glutathione depletion in skeletal muscle in humans following standardized surgical trauma.

  11. Variation of neck muscle strength along the human cervical spine.

    Science.gov (United States)

    Oi, Nelson; Pandy, Marcus G; Myers, Barry S; Nightingale, Roger W; Chancey, Valeta Carol

    2004-11-01

    The aim of this study was to describe and explain the variation of neck muscle strength along the cervical spine. A three-dimensional model of the head-neck complex was developed to test the hypothesis that the moment-generating capacity of the neck musculature is lower in the upper cervical spine than in the lower cervical spine. The model calculations suggest that the neck muscles can protect the lower cervical spine from injury during extension and lateral bending. The maximum flexor moment developed in the lower cervical spine was 2 times higher than that developed in the upper spine. The model also predicted that the neck musculature is 30% stronger in the lower cervical spine during lateral bending. Peak compressive forces (up to 3 times body weight) were higher in the lower cervical spine. These results are consistent with the clinical finding that extension loading of the neck often leads to injuries in the upper cervical spine. Analysis of the model results showed that neck flexor strength was greater in the lower cervical spine because of the relatively large size of the sternocleidomastoid muscle. The hyoid muscles developed significant flexor moments about the joints of the upper cervical spine, as these muscles had relatively large flexor moment arms; however, this effect was offset by the action of the sternocleidomastoid, which exerted a large extensor moment in the upper spine. Lateral bending strength of the neck muscles was governed by geometry (i.e., moment arms) rather than by muscle size.

  12. Myosin Heavy Chain Composition of the Human Genioglossus Muscle

    Science.gov (United States)

    Daugherty, Megan; Luo, Qingwei; Sokoloff, Alan J.

    2012-01-01

    Background: The human tongue muscle genioglossus (GG) is active in speech, swallowing, respiration, and oral transport, behaviors encompassing a wide range of tongue shapes and movement speeds. Studies demonstrate substantial diversity in patterns of human GG motor unit activation, but whether this is accompanied by complex expression of muscle…

  13. Myosin Heavy Chain Composition of the Human Genioglossus Muscle

    Science.gov (United States)

    Daugherty, Megan; Luo, Qingwei; Sokoloff, Alan J.

    2012-01-01

    Background: The human tongue muscle genioglossus (GG) is active in speech, swallowing, respiration, and oral transport, behaviors encompassing a wide range of tongue shapes and movement speeds. Studies demonstrate substantial diversity in patterns of human GG motor unit activation, but whether this is accompanied by complex expression of muscle…

  14. Human muscle proteins: analysis by two-dimensional electrophoresis

    Energy Technology Data Exchange (ETDEWEB)

    Giometti, C.S.; Danon, M.J.; Anderson, N.G.

    1983-09-01

    Proteins from single frozen sections of human muscle were separated by two-dimensional gel electrophoresis and detected by fluorography or Coomassie Blue staining. The major proteins were identical in different normal muscles obtained from either sex at different ages, and in Duchenne and myotonic dystrophy samples. Congenital myopathy denervation atrophy, polymyositis, and Becker's muscular dystrophy samples, however, showed abnormal myosin light chain compositions, some with a decrease of fast-fiber myosin light chains and others with a decrease of slow-fiber light chains. These protein alterations did not correlate with any specific disease, and may be cause by generalized muscle-fiber damage.

  15. Reducing body fat with altitude hypoxia training in swimmers: role of blood perfusion to skeletal muscles.

    Science.gov (United States)

    Chia, Michael; Liao, Chin-An; Huang, Chih-Yang; Lee, Wen-Chih; Hou, Chien-Wen; Yu, Szu-Hsien; Harris, M Brennan; Hsu, Tung-Shiung; Lee, Shin-Da; Kuo, Chia-Hua

    2013-02-28

    Swimmers tend to have greater body fat than athletes from other sports. The purpose of the study was to examine changes in body composition after altitude hypoxia exposure and the role of blood distribution to the skeletal muscle in swimmers. With a constant training volume of 12.3 km/day, young male swimmers (N = 10, 14.8 ± 0.5 years) moved from sea-level to a higher altitude of 2,300 meters. Body composition was measured before and after translocation to altitude using dual-energy X-ray absorptiometry (DXA) along with 8 control male subjects who resided at sea level for the same period of time. To determine the effects of hypoxia on muscle blood perfusion, total hemoglobin concentration (THC) was traced by near-infrared spectroscopy (NIRS) in the triceps and quadriceps muscles under glucose-ingested and insulin-secreted conditions during hypoxia exposure (16% O2) after training. While no change in body composition was found in the control group, subjects who trained at altitude had unequivocally decreased fat mass (-1.7 ± 0.3 kg, -11.4%) with increased lean mass (+0.8 ± 0.2 kg, +1.5%). Arterial oxygen saturation significantly decreased with increased plasma lactate during hypoxia recovery mimicking 2,300 meters at altitude (~93% versus ~97%). Intriguingly, hypoxia resulted in elevated muscle THC, and sympathetic nervous activities occurred in parallel with greater-percent oxygen saturation in both muscle groups. In conclusion, the present study provides evidence that increased blood distribution to the skeletal muscle under postprandial condition may contribute to the reciprocally increased muscle mass and decreased body mass after a 3-week altitude exposure in swimmers.

  16. Human skeletal muscle digitalis glycoside receptors (Na,K-ATPase)--importance during digitalization.

    Science.gov (United States)

    Schmidt, T A; Holm-Nielsen, P; Kjeldsen, K

    1993-02-01

    The aims of the present study were to evaluate in humans the putative importance of skeletal muscle digitalis glycoside receptors (Na,K-ATPase) in the volume of distribution of digoxin and to assess whether therapeutic digoxin exposure might cause digitalis receptor upregulation in skeletal muscle. Samples of the vastus lateralis were obtained postmortem from 11 long-term (9 months to 9 years) digitalized (125-187.5 micrograms daily) and eight undigitalized subjects. In intact samples from digitalized patients, vanadate-facilitated 3H-ouabain binding increased 15% (p 0.30) before and after washing in specific digoxin antibody fragments, respectively. Thus, the present study indicates a approximately 13% occupancy of skeletal muscle digitalis glycoside receptors with digoxin during digitalization. In light of the large skeletal muscle contribution to body mass, this indicates that the skeletal muscle Na,K-ATPase pool constitutes a major volume of distribution for digoxin during digitalization. The results gave no indication of skeletal muscle digitalis glycoside receptor upregulation in response to digoxin treatment. On the contrary, there was evidence of significantly lower (37%, p digitalized patients, which may be of importance for skeletal muscle incapacity in heart failure.

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

    Science.gov (United States)

    Spanjaard, M; Reeves, N D; van Dieën, 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 different step-heights (changing the kinematic constraints): standard (17 cm), 50% decreased, 50% increased and 75% increased. At the standard height, subjects also ascended the stairs wearing a weighted jacket, adding 20% of their body mass (changing the kinetic constraints). During stair ascent, kinematics and kinetics of the lower legs were determined using motion capture and ground reaction force measurements. The GM muscle fascicle length was measured during the task with ultrasonography. The amount of GM muscle fascicle shortening increased with step-height, coinciding with an increase in ankle joint moment. The increase in body mass resulted in an increased ankle joint moment, but the amount of GM muscle fascicle shortening during the lift-off phase did not increase, instead, the fascicles were shorter over the whole stride cycle. Increasing demands of stair ascent, by increasing step-height or body mass, requires higher joint moments. The increased ankle joint moment with increasing demands is, at least in part, produced by the increase in GM muscle fascicle shortening.

  18. Scandinavian Semantics and the Human Body

    DEFF Research Database (Denmark)

    Levisen, Carsten

    2015-01-01

    , it is demonstrated that Scandinavian and English systems differ significantly in some aspects of the way in which the construe the human body with words. The study ventures an innovative combination of methods, pairing the Natural Semantic Metalanguage (NSM) approach to linguistic and conceptual analysis...... in closely related languages can differ substantially in their semantics. In related languages, where shared lexical form does not always mean shared semantics, ethnolinguistic studies in semantic change and shifts in polysemy patterns can help to reveal and explain the roots of semantic diversity.......This paper presents an ethnolinguistic analysis of how the space between the head and the body is construed in Scandinavian semantic systems vis-a-vis the semantic system of English. With an extensive case study of neck-related meanings in Danish, and with cross-Scandinavian reference...

  19. [The human body in Michelangelo's Moses].

    Science.gov (United States)

    Figueroa, Gustavo

    2013-10-01

    What grips us so powerfully to a work of art is the artist's intention, if he succeeds to express it in his work and we are able to understand it. Michelangelo's Moses established the essential structures of an animate organism and the embodiment of consciousness in the world. Since the body is an expressive unit, it is possible to reconstruct a highly feasible sequence of movements that might have preceded the moment caught in the statue. It is an expression of the highest ideal of mental and spiritual achievement through the controlled tension between action and restraint. The phenomenon of embodiment and feeling the body as own is the basis of concrete human existence.

  20. Skeletal muscle TLR4 and TACE are associated with body fat percentage in older adults.

    Science.gov (United States)

    Timmerman, Kyle L; Connors, Ian D; Deal, Michael A; Mott, Rachael E

    2016-04-01

    Elevated skeletal muscle expression of toll-like receptor 4 (TLR4) has been linked to increased inflammation in clinical populations. TNFα converting enzyme (TACE), which cleaves membrane-bound TNFα (mTNFα) to its soluble (sTNFα) and more bioactive form, has been linked to chronic disease. In contrast, higher physical activity level is associated with decreased chronic disease risk and inflammation. The purpose of the present study was to examine the relationship between physical activity and skeletal muscle TLR4, TACE, and TNFα in older adults. In 26 older adults (age = 68 ± 4 years, body mass index = 26 ± 3 kg·m(-2)), self-reported physical activity (kcal·week(-1)), estimated maximal oxygen consumption, and body composition (air plethysmography) were measured. TLR4, TACE, mTNFα, and sTNFα were measured in skeletal muscle biopsies (vastus lateralis) using western blot analyses. Pearson product-moment correlations were run between variables. Significance was set at p muscle TACE was directly associated with sTNFα (r = 0.53, p fat was directly associated with skeletal muscle TLR4 (r = 0.52, p fat was directly associated with TLR4 and TACE expression in skeletal muscle of older adults. These findings suggest that elevated skeletal muscle expression of TLR4 and TACE may contribute to the augmented inflammation and chronic disease risk observed with increased adiposity.

  1. Earthing the human body influences physiologic processes.

    Science.gov (United States)

    Sokal, Karol; Sokal, Pawel

    2011-04-01

    This study was designed to answer the question: Does the contact of the human organism with the Earth via a copper conductor affect physiologic processes? Subjects and experiments: Five (5) experiments are presented: experiment 1-effect of earthing on calcium-phosphate homeostasis and serum concentrations of iron (N = 84 participants); experiment 2-effect of earthing on serum concentrations of electrolytes (N = 28); experiment 3-effect of earthing on thyroid function (N = 12); experiment 4-effect of earthing on glucose concentration (N = 12); experiment 5-effect of earthing on immune response to vaccine (N = 32). Subjects were divided into two groups. One (1) group of people was earthed, while the second group remained without contact with the Earth. Blood and urine samples were examined. Earthing of an electrically insulated human organism during night rest causes lowering of serum concentrations of iron, ionized calcium, inorganic phosphorus, and reduction of renal excretion of calcium and phosphorus. Earthing during night rest decreases free tri-iodothyronine and increases free thyroxine and thyroid-stimulating hormone. The continuous earthing of the human body decreases blood glucose in patients with diabetes. Earthing decreases sodium, potassium, magnesium, iron, total protein, and albumin concentrations while the levels of transferrin, ferritin, and globulins α1, α2, β, and γ increase. These results are statistically significant. Earthing the human body influences human physiologic processes. This influence is observed during night relaxation and during physical activity. Effect of the earthing on calcium-phosphate homeostasis is the opposite of that which occurs in states of weightlessness. It also increases the activity of catabolic processes. It may be the primary factor regulating endocrine and nervous systems.

  2. Human body region enhancement method based on Kinect infrared imaging

    Science.gov (United States)

    Yang, Lei; Fan, Yubo; Song, Xiaowei; Cai, Wenjing

    2016-10-01

    To effectively improve the low contrast of human body region in the infrared images, a combing method of several enhancement methods is utilized to enhance the human body region. Firstly, for the infrared images acquired by Kinect, in order to improve the overall contrast of the infrared images, an Optimal Contrast-Tone Mapping (OCTM) method with multi-iterations is applied to balance the contrast of low-luminosity infrared images. Secondly, to enhance the human body region better, a Level Set algorithm is employed to improve the contour edges of human body region. Finally, to further improve the human body region in infrared images, Laplacian Pyramid decomposition is adopted to enhance the contour-improved human body region. Meanwhile, the background area without human body region is processed by bilateral filtering to improve the overall effect. With theoretical analysis and experimental verification, the results show that the proposed method could effectively enhance the human body region of such infrared images.

  3. Cyclooxygenase products sensitize muscle mechanoreceptors in humans with heart failure.

    Science.gov (United States)

    Middlekauff, Holly R; Chiu, Josephine; Hamilton, Michele A; Fonarow, Gregg C; Maclellan, W Robb; Hage, Antoine; Moriguchi, Jaime; Patel, Jignesh

    2008-04-01

    Prior work in animals and humans suggests that muscle mechanoreceptor control of sympathetic activation [muscle sympathetic nerve activity (MSNA)] during exercise in heart failure (HF) patients is heightened compared with that of healthy humans and that muscle mechanoreceptors are sensitized by metabolic by-products. We sought to determine whether cyclooxygenase products and/or endogenous adenosine, two metabolites of ischemic exercise, sensitize muscle mechanoreceptors during rhythmic handgrip (RHG) exercise in HF patients. Indomethacin, which inhibits the production of prostaglandins, and saline control were infused in 12 HF patients. In a different protocol, aminophylline, which inhibits adenosine receptors, and saline control were infused in 12 different HF patients. MSNA was recorded (microneurography). During exercise following saline, MSNA increased in the first minute of exercise, consistent with baseline heightened mechanoreceptor sensitivity. MSNA continued to increase during 3 min of RHG, indicative that muscle mechanoreceptors are sensitized by ischemia metabolites. Indomethacin, but not aminophylline, markedly attenuated the increase in MSNA during the entire 3 min of low-level rhythmic exercise, consistent with the sensitization of muscle mechanoreceptors by cyclooxygenase products. Interestingly, even the early increase in MSNA was abolished by indomethacin infusion, indicative of the very early generation of cyclooxygenase products after the onset of exercise in HF patients. In conclusion, muscle mechanoreceptors mediate the increase in MSNA during low-level RHG exercise in HF. Cyclooxygenase products, but not endogenous adenosine, play a central role in muscle mechanoreceptor sensitization. Finally, muscle mechanoreceptors in patients with HF have heightened basal sensitivity to mechanical stimuli, which also appears to be mediated by the early generation of cyclooxygenase products, resulting in exaggerated early increases in MSNA.

  4. Signaling pathways in failing human heart muscle cells.

    Science.gov (United States)

    Drexler, H; Hasenfuss, G; Holubarsch, C

    1997-07-01

    Experimental studies have delineated important signaling pathways in cardiomyocytes and their alterations in heart failure; however, there is now evidence that these observations are not necessarily applicable to human cardiac muscle cells. For example, angiotensin II (A II) does not exert positive inotropic effects in human ventricular muscle cells, in contrast to observation in rats. Thus, it is important to elucidate cardiac signaling pathways in humans in order to appreciate the functional role of neurohumoral or mechanical stimulation in human myocardium in health and disease. In the present article, we review signal pathways in the failing human heart based on studies in human cardiac tissues and in vivo physiological studies related to A II, nitric oxide, and β-adrenergic stimulation. (Trends Cardiovasc Med 1997; 7:151-160). © 1997, Elsevier Science Inc.

  5. A modular approach to numerical human body modeling

    NARCIS (Netherlands)

    Forbes, P.A.; Griotto, G.; Rooij, L. van

    2007-01-01

    The choice of a human body model for a simulated automotive impact scenario must take into account both accurate model response and computational efficiency as key factors. This study presents a "modular numerical human body modeling" approach which allows the creation of a customized human body mod

  6. A modular approach to numerical human body modeling

    NARCIS (Netherlands)

    Forbes, P.A.; Griotto, G.; Rooij, L. van

    2007-01-01

    The choice of a human body model for a simulated automotive impact scenario must take into account both accurate model response and computational efficiency as key factors. This study presents a "modular numerical human body modeling" approach which allows the creation of a customized human body

  7. Calorie restriction increases muscle mitochondrial biogenesis in healthy humans.

    Directory of Open Access Journals (Sweden)

    Anthony E Civitarese

    2007-03-01

    Full Text Available Caloric restriction without malnutrition extends life span in a range of organisms including insects and mammals and lowers free radical production by the mitochondria. However, the mechanism responsible for this adaptation are poorly understood.The current study was undertaken to examine muscle mitochondrial bioenergetics in response to caloric restriction alone or in combination with exercise in 36 young (36.8 +/- 1.0 y, overweight (body mass index, 27.8 +/- 0.7 kg/m(2 individuals randomized into one of three groups for a 6-mo intervention: Control, 100% of energy requirements; CR, 25% caloric restriction; and CREX, caloric restriction with exercise (CREX, 12.5% CR + 12.5% increased energy expenditure (EE. In the controls, 24-h EE was unchanged, but in CR and CREX it was significantly reduced from baseline even after adjustment for the loss of metabolic mass (CR, -135 +/- 42 kcal/d, p = 0.002 and CREX, -117 +/- 52 kcal/d, p = 0.008. Participants in the CR and CREX groups had increased expression of genes encoding proteins involved in mitochondrial function such as PPARGC1A, TFAM, eNOS, SIRT1, and PARL (all, p < 0.05. In parallel, mitochondrial DNA content increased by 35% +/- 5% in the CR group (p = 0.005 and 21% +/- 4% in the CREX group (p < 0.004, with no change in the control group (2% +/- 2%. However, the activity of key mitochondrial enzymes of the TCA (tricarboxylic acid cycle (citrate synthase, beta-oxidation (beta-hydroxyacyl-CoA dehydrogenase, and electron transport chain (cytochrome C oxidase II was unchanged. DNA damage was reduced from baseline in the CR (-0.56 +/- 0.11 arbitrary units, p = 0.003 and CREX (-0.45 +/- 0.12 arbitrary units, p = 0.011, but not in the controls. In primary cultures of human myotubes, a nitric oxide donor (mimicking eNOS signaling induced mitochondrial biogenesis but failed to induce SIRT1 protein expression, suggesting that additional factors may regulate SIRT1 content during CR.The observed increase in

  8. Relationships Between Lower-Body Muscle Structure and, Lower-Body Strength, Explosiveness and Eccentric Leg Stiffness in Adolescent Athletes

    Directory of Open Access Journals (Sweden)

    Josh L. Secomb, Sophia Nimphius, Oliver R.L. Farley, Lina E. Lundgren, Tai T. Tran, Jeremy M. Sheppard

    2015-12-01

    Full Text Available The purpose of the present study was to determine whether any relationships were present between lower-body muscle structure and, lower-body strength, variables measured during a countermovement jump (CMJ and squat jump (SJ, and eccentric leg stiffness, in adolescent athletes. Thirty junior male (n = 23 and female (n = 7 surfing athletes (14.8 ± 1.7 y; 1.63 ± 0.09 m; 54.8 ± 12.1 kg undertook lower-body muscle structure assessment with ultrasonography and performed a; CMJ, SJ and an isometric mid-thigh pull (IMTP. In addition, eccentric leg stiffness was calculated from variables of the CMJ and IMTP. Moderate to very large relationships (r = 0.46-0.73 were identified between the thickness of the vastus lateralis (VL and lateral gastrocnemius (LG muscles, and VL pennation angle and; peak force (PF in the CMJ, SJ and IMTP. Additionally, moderate to large relationships (r = 0.37-0.59 were found between eccentric leg stiffness and; VL and LG thickness, VL pennation angle, and LG fascicle length, with a large relationship (r = 0.59 also present with IMTP PF. These results suggest that greater thickness of the VL and LG were related to improved maximal dynamic and isometric strength, likely due to increased hypertrophy of the extensor muscles. Furthermore, this increased thickness was related to greater eccentric leg stiffness, as the associated enhanced lower-body strength likely allowed for greater neuromuscular activation, and hence less compliance, during a stretch-shortening cycle.

  9. Fetuses of lean and obese swine in late gestation: body composition, plasma hormones and muscle development.

    Science.gov (United States)

    Hoffman, E C; Wangsness, P J; Hagen, D R; Etherton, T D

    1983-09-01

    The development of obesity in porcine fetuses was investigated using a lean and obese strain of pigs at 80, 90, 100 and 110 d of gestation. In absolute terms, fetuses of obese gilts (FO) generally had lower carcass weight and contained less total protein, dry matter and ash than fetuses of lean gilts (FL). In relative terms (percentage of wet carcass weight) FO, compared with FL, generally had decreased percentages of water and increased percentages of protein and lipid. Comparisons based on absolute terms revealed body composition of the strains to be different at 90 d, indicating that factors responsible for obese-type growth were active before that time. Both body composition and hormone concentration differences were most pronounced at later gestation ages. Depressed growth hormone, elevated cortisol, and a tendency toward elevated insulin concentrations in fetal plasma were apparent in late gestation for FO compared with FL. These hormonal patterns are consistent with onset of obesity in FO in late gestation. Greater weights of semitendinosus and longissimus muscles were observed in FL vs FO at 90, 100 and 110 d of gestation (P less than .05). These greater muscle weights were generally accompanied by greater contents of RNA, DNA and protein in FL muscles at these same ages. However, at 80 d, FL had greater absolute DNA content in semitendinosus muscle whereas muscle weight was similar between the strains. This suggests that greater muscle weights for FL than FO were caused by more nuclei in muscle of FL. In general, indices of hypertrophy (protein/DNA) and protein synthetic capacity (RNA/DNA) of muscle were usually similar for both strains at all gestation ages. It is concluded that decreased muscle growth in late gestation of FO compared with FL is more related to fewer total nuclei and perhaps fewer myofibers than to an impaired cellular capacity for protein synthesis.

  10. Isomap transform for segmenting human body shapes.

    Science.gov (United States)

    Cerveri, P; Sarro, K J; Marchente, M; Barros, R M L

    2011-09-01

    Segmentation of the 3D human body is a very challenging problem in applications exploiting volume capture data. Direct clustering in the Euclidean space is usually complex or even unsolvable. This paper presents an original method based on the Isomap (isometric feature mapping) transform of the volume data-set. The 3D articulated posture is mapped by Isomap in the pose of Da Vinci's Vitruvian man. The limbs are unrolled from each other and separated from the trunk and pelvis, and the topology of the human body shape is recovered. In such a configuration, Hoshen-Kopelman clustering applied to concentric spherical shells is used to automatically group points into the labelled principal curves. Shepard interpolation is utilised to back-map points of the principal curves into the original volume space. The experimental results performed on many different postures have proved the validity of the proposed method. Reliability of less than 2 cm and 3° in the location of the joint centres and direction axes of rotations has been obtained, respectively, which qualifies this procedure as a potential tool for markerless motion analysis.

  11. Development of digastric muscles in human fetuses: a review and findings in the flexor digitorum superficialis muscle.

    Science.gov (United States)

    Rodríguez-Vázquez, José Francisco; Jin, Zhe Wu; Zhao, Peng; Murakami, Gen; Li, Xiang Wu; Jin, Yu

    2017-09-04

    The digastricus and omohyoideus muscles are digastric muscles with two muscle bellies. An insertion tendon of the posterior belly becomes an intermediate tendon in digastricus muscles, whereas a single band-like muscle in omohyoideus muscles may later be interrupted by an intermediate tendon, possibly due to muscle cell death caused by mechanical stress. In human fetuses, an intermediate tendon provides the temporal origins of the tensor veli palatini and tensor tympani muscles. Some reptiles, including snakes, carry multiple series of digastric-like axial muscles, in which each intersegmental septum is likely to become an intermediate tendon. These findings indicate that many pathways are involved in the development of digastric muscles. A review of these morphologies suggested that the flexor digitorum superficialis (FDS) muscle was a digastric muscle, although the intermediate tendon may not be visible in the surface view in adults. The present observations support the hypothesis that the proximal anlage at the elbow develops into a deep muscle slip to a limited finger, while the distal anlage at the wrist develops into the other slips. The findings suggest that, in the FDS muscle, the proximal and distal bellies of the embryonic digastric muscle fuse together to form a laminar structure, in which muscle slips accumulate from the palmar to the deep side of the forearm.

  12. Calprotectin is released from human skeletal muscle tissue during exercise

    DEFF Research Database (Denmark)

    Mortensen, Ole Hartvig; Andersen, Kasper; Fischer, Christian

    2008-01-01

    Skeletal muscle has been identified as a secretory organ. We hypothesized that IL-6, a cytokine secreted from skeletal muscle during exercise, could induce production of other secreted factors in skeletal muscle. IL-6 was infused for 3 h into healthy young males (n = 7) and muscle biopsies obtained...... at time points 0, 3 and 6 h in these individuals and in resting controls. Affymetrix microarray analysis of gene expression changes in skeletal muscle biopsies identified a small set of genes changed by IL-6 infusion. RT-PCR validation confirmed that S100A8 and S100A9 mRNA were up-regulated 3-fold...... in skeletal muscle following IL-6 infusion compared to controls. Furthermore, S100A8 and S100A9 mRNA levels were up-regulated 5-fold in human skeletal muscle following cycle ergometer exercise for 3 h at approximately 60% of in young healthy males (n = 8). S100A8 and S100A9 form calprotectin, which is known...

  13. Postmortem muscle protein degradation in humans as a tool for PMI delimitation.

    Science.gov (United States)

    Pittner, Stefan; Ehrenfellner, Bianca; Monticelli, Fabio C; Zissler, Angela; Sänger, Alexandra M; Stoiber, Walter; Steinbacher, Peter

    2016-11-01

    Forensic estimation of time since death relies on diverse approaches, including measurement and comparison of environmental and body core temperature and analysis of insect colonization on a dead body. However, most of the applied methods have practical limitations or provide insufficient results under certain circumstances. Thus, new methods that can easily be implemented into forensic routine work are required to deliver more and discrete information about the postmortem interval (PMI). Following a previous work on skeletal muscle degradation in the porcine model, we analyzed human postmortem skeletal muscle samples of 40 forensic cases by Western blotting and casein zymography. Our results demonstrate predictable protein degradation processes in human muscle that are distinctly associated with temperature and the PMI. We provide information on promising degradation markers for certain periods of time postmortem, which can be useful tools for time since death delimitation. In addition, we discuss external influencing factors such as age, body mass index, sex, and cause of death that need to be considered in future routine application of the method in humans.

  14. INSULIN HORMONE EFFECTS ON FT&ST MUSCLES OF BODY BULDING ATHLETS AND DIABETIC PEOPLE TYPE

    Directory of Open Access Journals (Sweden)

    MEHDI GHORBANI

    2014-07-01

    Full Text Available Insulin is a Hormone that is secreted from pancreas and has an undeniable role in regulating blood - suger. In medicine, the injection samples of this Hormone are used for controlling diabetes disease. But recently, it has been used by athletes for driving G lucose and Amino Acids in to muscle - cells in industrial and injection forms for fast development of muscle volume and power among potency athletes specially body - builders. The present study, is reviewing consumption consequences of this drug by athletes and it’s important and of course hidden hazards. In this study, the Hormone’s impression and it’s high secretion and mechanism imbalance in body - builders bodies are analyzed by following Dosage and period of Insulin consumption among athletes and body - b uilders and studying different forms and injection amounts of Insulin, and comparing them with diabetes disease. Results show that Insulin is a Hormone with high Anabolic effect and it is responsible for nutrient materials transmission into blood stream an d muscle - cells. The blood - suger is saved as glycogen in muscles on this hormone effect and Amino acid transmission is developed in body’s muscle system. This features by muscle manufacturing apparent of athletes and muscle exhausting delay in fast contra cting muscle fibers and enthusiasm of practicing for hours, dosen’t cause to ignore the dangerous disadvantageous of this hormone including: imbalance of metabolism such as extra lipid burning and glycogen saving in body. Because of Insulin long consumptio n body produces little amount of glycogen and adrenaline hormones to re increase the amount of blood - suger, therefore increasing blood - suger isn’t declared with warning signals such as: trembling and nervousness, and athletes encounter with the shock of decreasing blood - suger (Hyper - glysemia and die. This study shows that in correct consumption of diabetes drugs are hazardous in body. Builders in different

  15. Duchenne Muscular Dystrophy Gene Expression in Normal and Diseased Human Muscle

    Science.gov (United States)

    Oronzi Scott, M.; Sylvester, J. E.; Heiman-Patterson, T.; Shi, Y.-J.; Fieles, W.; Stedman, H.; Burghes, A.; Ray, P.; Worton, R.; Fischbeck, K. H.

    1988-03-01

    A probe for the 5' end of the Duchenne muscular dystrophy (DMD) gene was used to study expression of the gene in normal human muscle, myogenic cell cultures, and muscle from patients with DMD. Expression was found in RNA from normal fetal muscle, adult cardiac and skeletal muscle, and cultured muscle after myoblast fusion. In DMD muscle, expression of this portion of the gene was also revealed by in situ RNA hybridization, particularly in regenerating muscle fibers.

  16. Training affects muscle phospholipid fatty acid composition in humans

    DEFF Research Database (Denmark)

    Helge, Jørn Wulff; Wu, B J; Willer, Mette

    2001-01-01

    Training improves insulin sensitivity, which in turn may affect performance by modulation of fuel availability. Insulin action, in turn, has been linked to specific patterns of muscle structural lipids in skeletal muscle. This study investigated whether regular exercise training exerts an effect...... on the muscle membrane phospholipid fatty acid composition in humans. Seven male subjects performed endurance training of the knee extensors of one leg for 4 wk. The other leg served as a control. Before, after 4 days, and after 4 wk, muscle biopsies were obtained from the vastus lateralis. After 4 wk......, the phospholipid fatty acid contents of oleic acid 18:1(n-9) and docosahexaenoic acid 22:6(n-3) were significantly higher in the trained (10.9 +/- 0.5% and 3.2 +/- 0.4% of total fatty acids, respectively) than the untrained leg (8.8 +/- 0.5% and 2.6 +/- 0.4%, P

  17. Relationship between Human Aging Muscle and Oxidative System Pathway

    Directory of Open Access Journals (Sweden)

    Enrico Doria

    2012-01-01

    Full Text Available Ageing is a complex process that in muscle is usually associated with a decrease in mass, strength, and velocity of contraction. One of the most striking effects of ageing on muscle is known as sarcopenia. This inevitable biological process is characterized by a general decline in the physiological and biochemical functions of the major systems. At the cellular level, aging is caused by a progressive decline in mitochondrial function that results in the accumulation of reactive oxygen species (ROS generated by the addition of a single electron to the oxygen molecule. The aging process is characterized by an imbalance between an increase in the production of reactive oxygen species in the organism and the antioxidant defences as a whole. The goal of this review is to examine the results of existing studies on oxidative stress in aging human skeletal muscles, taking into account different physiological factors (sex, fibre composition, muscle type, and function.

  18. Exercise-induced metallothionein expression in human skeletal muscle fibres

    DEFF Research Database (Denmark)

    Penkowa, Milena; Keller, Pernille; Keller, Charlotte;

    2005-01-01

    in both type I and II muscle fibres. This is the first report demonstrating that MT-I + II are significantly induced in human skeletal muscle fibres following exercise. As MT-I + II are antioxidant factors that protect various tissues during pathological conditions, the MT-I + II increases post exercise......Exercise induces free oxygen radicals that cause oxidative stress, and metallothioneins (MTs) are increased in states of oxidative stress and possess anti-apoptotic effects. We therefore studied expression of the antioxidant factors metallothionein I and II (MT-I + II) in muscle biopsies obtained...... in response to 3 h of bicycle exercise performed by healthy men and in resting controls. Both MT-I + II proteins and MT-II mRNA expression increased significantly in both type I and II muscle fibres after exercise. Moreover, 24 h after exercise the levels of MT-II mRNA and MT-I + II proteins were still highly...

  19. DNA and RNA analysis of blood and muscle from bodies with variable postmortem intervals

    DEFF Research Database (Denmark)

    Hansen, Jakob; Lesnikova, Iana; Funder, Anette Mariane Daa

    2014-01-01

    ranging from one to more than 14 days. It was not possible to collect blood from 38 % of the autopsy cases due to severe coagulation and hemolysis, whereas muscle tissue was available for all cases. PCR-amplifiable DNA could be extracted from 96 % of the frozen muscle specimens and from 93......The breakdown of DNA and RNA in decomposing human tissue represents a major obstacle for postmortem forensic molecular analysis. This study investigated the feasibility of performing PCR-based molecular analysis of blood and muscle tissue from 45 autopsy cases with defined postmortem intervals......) DNA fragments from all samples with postmortem intervals below 3 days whereas 400-600 bp long fragments typically could be amplified from the most decomposed muscle specimens. RNA was less stable than DNA in postmortem muscle tissue, yet selected mRNA molecules could be detected by reverse...

  20. Red muscle function in stiff-bodied swimmers: there and almost back again

    Science.gov (United States)

    Syme, Douglas A.; Shadwick, Robert E.

    2011-01-01

    Fishes with internalized and endothermic red muscles (i.e. tunas and lamnid sharks) are known for a stiff-bodied form of undulatory swimming, based on unique muscle–tendon architecture that limits lateral undulation to the tail region even though the red muscle is shifted anteriorly. A strong convergence between lamnid sharks and tunas in these features suggests that thunniform swimming might be evolutionarily tied to this specialization of red muscle, but recent observations on the common thresher shark (Alopias vulpinus) do not support this view. Here, we review the fundamental features of the locomotor systems in lamnids and tunas, and present data on in vivo muscle function and swimming mechanics in thresher sharks. These results suggest that the presence of endothermic and internalized red muscles alone in a fish does not predict or constrain the swimming mode to be thunniform and, indeed, that the benefits of this type of muscle may vary greatly as a consequence of body size. PMID:21502122

  1. Adaptability of elderly human muscles and tendons to increased loading.

    Science.gov (United States)

    Narici, Marco V; Maganaris, Constantinos N

    2006-04-01

    Senile sarcopenia, the loss of muscle mass associated with aging, is one of the main causes of muscle weakness and reduced locomotor ability in old age. Although this condition is mainly driven by neuropathic processes, nutritional, hormonal and immunological factors, as well as a reduction in physical activity, contribute to this phenomenon. Sarcopenia alone, however, does not fully account for the observed muscle weakness, as the loss of force is greater than that accounted for by the decrease in muscle size. As a consequence, a reduction in the force per unit area, both at single fibre and at whole muscle level, is observed. We recently suggested that at whole muscle level, this reduction in intrinsic force is the result of the combined effect of changes in (1) muscle architecture, (2) tendon mechanical properties, (3) neural drive (reduced agonist and increased antagonist muscle activity) and (4) single fibre-specific tension. Whereas several studies support the role of the last two factors in the loss of intrinsic muscle force with aging, alterations in muscle architecture and in tendon mechanical properties have also been shown to contribute to the above phenomenon. Indeed, sarcopenia of the human plantarflexors, represented by a 25% reduction in muscle volume, was found to be associated with a 10% reduction in fibre fascicle length and 13% reduction in pennation angle. These architectural alterations were accompanied by a 10% decrease in tendon stiffness, attributable to alterations in tendon material properties, as suggested by a 14% decrease in Young's modulus. Most of these changes may be reversed by 14 weeks of resistive training; both fibre fascicle length and tendon stiffness were found to be increased by 10 and 64%, respectively. Surprisingly, however, training had no effect on the estimated relative length-tension properties of the muscle, indicating that the effects of greater tendon stiffness and increased fascicle length cancelled out each other

  2. Nonlinear muscles, passive viscoelasticity and body taper conspire to create neuromechanical phase lags in anguilliform swimmers.

    Directory of Open Access Journals (Sweden)

    T McMillen

    2008-08-01

    Full Text Available Locomotion provides superb examples of cooperation among neuromuscular systems, environmental reaction forces, and sensory feedback. As part of a program to understand the neuromechanics of locomotion, here we construct a model of anguilliform (eel-like swimming in slender fishes. Building on a continuum mechanical representation of the body as an viscoelastic rod, actuated by a traveling wave of preferred curvature and subject to hydrodynamic reaction forces, we incorporate a new version of a calcium release and muscle force model, fitted to data from the lamprey Ichthyomyzon unicuspis, that interactively generates the curvature wave. We use the model to investigate the source of the difference in speeds observed between electromyographic waves of muscle activation and mechanical waves of body curvature, concluding that it is due to a combination of passive viscoelastic and geometric properties of the body and active muscle properties. Moreover, we find that nonlinear force dependence on muscle length and shortening velocity may reduce the work done by the swimming muscles in steady swimming.

  3. Body position effects on EMG activity of sternocleidomastoid and masseter muscles in healthy subjects.

    Science.gov (United States)

    Miralles, R; Palazzi, C; Ormeño, G; Giannini, R; Verdugo, F; Valenzuela, S; Santander, H

    1998-04-01

    This study was conducted in order to determine the effects of body position on integrated electromyographic (IEMG) activity of sternocleidomastoid and masseter muscles in 20 healthy subjects. EMG recordings at rest and during swallowing of saliva and maximal voluntary clenching were performed by placing surface electrodes on the sternocleidomastoid and masseter muscles (contralateral to the habitual side of sleeping of each subject), in the following body positions: standing, seated, supine, and lateral decubitus position. Significant higher EMG activities were recorded in the sternocleidomastoid muscle in the lateral decubitus position, whereas significant lower EMG activities were recorded in the masseter muscle in the supine position. This finding supports the idea that there may exist a differential modulation of the motor neuron pools of the sternocleidomastoid and masseter muscles of peripheral and/or central origin. Significant differences in the EMG pattern as well as in the levels of EMG activities upon variations in body positions were observed between healthy subjects and patients with myogenic craniomandibular dysfunction reported by Palazzi, et al.

  4. "Nutraceuticals" in relation to human skeletal muscle and exercise.

    Science.gov (United States)

    Deane, Colleen S; Wilkinson, Daniel J; Phillips, Bethan E; Smith, Kenneth; Etheridge, Timothy; Atherton, Philip J

    2017-04-01

    Skeletal muscles have a fundamental role in locomotion and whole body metabolism, with muscle mass and quality being linked to improved health and even lifespan. Optimizing nutrition in combination with exercise is considered an established, effective ergogenic practice for athletic performance. Importantly, exercise and nutritional approaches also remain arguably the most effective countermeasure for muscle dysfunction associated with aging and numerous clinical conditions, e.g., cancer cachexia, COPD, and organ failure, via engendering favorable adaptations such as increased muscle mass and oxidative capacity. Therefore, it is important to consider the effects of established and novel effectors of muscle mass, function, and metabolism in relation to nutrition and exercise. To address this gap, in this review, we detail existing evidence surrounding the efficacy of a nonexhaustive list of macronutrient, micronutrient, and "nutraceutical" compounds alone and in combination with exercise in relation to skeletal muscle mass, metabolism (protein and fuel), and exercise performance (i.e., strength and endurance capacity). It has long been established that macronutrients have specific roles and impact upon protein metabolism and exercise performance, (i.e., protein positively influences muscle mass and protein metabolism), whereas carbohydrate and fat intakes can influence fuel metabolism and exercise performance. Regarding novel nutraceuticals, we show that the following ones in particular may have effects in relation to 1) muscle mass/protein metabolism: leucine, hydroxyl β-methylbutyrate, creatine, vitamin-D, ursolic acid, and phosphatidic acid; and 2) exercise performance: (i.e., strength or endurance capacity): hydroxyl β-methylbutyrate, carnitine, creatine, nitrates, and β-alanine. Copyright © 2017 the American Physiological Society.

  5. Whole-body fat oxidation determined by graded exercise and indirect calorimetry: a role for muscle oxidative capacity?

    DEFF Research Database (Denmark)

    Nordby, P; Saltin, B; Helge, J W

    2006-01-01

    During whole-body exercise, peak fat oxidation occurs at a moderate intensity. This study investigated whole-body peak fat oxidation in untrained and trained subjects, and the presence of a relation between skeletal muscle oxidative enzyme activity and whole-body peak fat oxidation. Healthy male...... muscle oxidative capacity was not correlated to whole-body peak fat oxidation. In conclusion, whole-body peak fat oxidation occurred at a higher relative exercise load in trained compared with untrained subjects. Whole-body peak fat oxidation was not significantly related to leg muscle oxidative capacity......, but was related to lean body mass and maximal oxygen uptake. This may suggest that leg muscle oxidative activity is not the main determinant of whole-body peak fat oxidation....

  6. Whole body and skeletal muscle protein turnover in recovery from burns.

    Science.gov (United States)

    Porter, Craig; Hurren, Nicholas M; Herndon, David N; Børsheim, Elisabet

    2013-01-01

    Trauma and critical illness are associated with a stress response that results in increased skeletal muscle protein catabolism, which is thought to facilitate the synthesis of acute phase proteins in the liver as well as proteins involved in immune function. What makes burn injury a unique form of trauma is the existence of vast skin lesions, where the majority of afflicted tissue is often surgically excised post injury. Thereafter, recovery is dependent on the formation of a significant quantity of new skin, meaning that the burned patient requires a large and sustained supply of amino acids to facilitate wound healing. Skeletal muscle has the capacity to store surplus glucose and fatty acids within glycogen and triacylglycerol depots respectively, where glycogen and fatty acids can be mobilized during prolonged periods of caloric restriction or heightened metabolic demand (e.g., exercise), to be catabolized in order to maintain cellular ATP availability. Amino acids, on the other hand, are not generally considered to be stored in such a manner within skeletal muscle, i.e., in a temporary pool independent of structural proteins and cellular organelles etc. Subsequently, in response to severe thermal trauma, skeletal muscle assumes the role of an amino acid reserve where muscle protein breakdown and amino acid release from skeletal muscle serves to buffer plasma amino acid concentrations. Interestingly, it seems like aggressive feeding of the severely burned patient may not necessarily supply amino acids in sufficient abundance to normalize skeletal muscle protein metabolism, suggesting that skeletal muscle becomes an essential store of protein in patients suffering from severe burn trauma. In this article, the effects of burn injury on whole body and skeletal muscle protein metabolism will be discussed in an attempt to distill the current understanding of the impact of this debilitating injury on the redistribution of skeletal muscle protein stores.

  7. Development of the stapedius muscle and pyramidal eminence in humans.

    Science.gov (United States)

    Rodríguez-Vázquez, J F

    2009-09-01

    The aim of the study was to systematize the key developmental phases of the stapedius muscle and the pyramidal eminence to clarify their formation, as well as to understand the variations and anomalies that can affect these structures. Sixty human embryos and fetuses between 38 days and 17 weeks of development were studied. The stapedius muscle is formed by two anlagen, one for the tendon, which derives from the internal segment of the interhyale, and another for the belly, located in the second pharyngeal arch medial to the facial nerve and near the interhyale but forming a completely independent anlage. In the interhyale, two segments were differentiated, these forming an angle; at the vertex, the belly of the stapedius muscle is attached. The internal segment is located from the attachment of the belly of the stapedius muscle to the anlage of the stapes, forming the anlage of the tendon of the stapedius muscle. The external segment completely disappears at the beginning of the fetal period. The pyramidal eminence is formed by an anlage independent of Reichert's cartilage, from the mesenchymal tissue of the tympanic cavity, which condenses around the belly of the stapedius muscle from 12 weeks of post-conception development. The length of the tendon of the stapedius muscle in adults varies, depending on the attachment site of the belly of the stapedius muscle in the interhyale, which would determine the length of the internal segment (anlage of the tendon) and consequently the tendon length. This variation depends on the greater or lesser persistence of the angulation observed during development, between the tendon and the belly of the stapedius muscle.

  8. Body uneasiness, eating disorders, and muscle dysmorphia in individuals who overexercise.

    Science.gov (United States)

    Segura-García, Cristina; Ammendolia, Antonio; Procopio, Leonardo; Papaianni, Maria C; Sinopoli, Flora; Bianco, Carmelina; De Fazio, Pasquale; Capranica, Laura

    2010-11-01

    This study aimed to investigate exercise dependence, body and eating concerns of active individuals in relation to muscle dysmorphia (MD) and eating disorders (EDs). One hundred and thirty-four active individuals (86 men, 48 women) and 20 ED women were divided into 4 groups according to their sex and the difference between their actual and desired body weight (group A: men who wanted to gain weight; group B: men who wanted to lose weight; group C: women who wanted to lose weight; group D: ED women). The Eating Disorder Inventory 2, Body Uneasiness Test, and Muscle Dysmorphia Inventory questionnaires were administered. All women desired to reduce their body weight, whereas 55% of men wanted to increase their muscle mass, also using anabolic steroids and food integrators. All groups showed a similar use of diuretics and laxatives (range 10-21%). The findings highlighted the presence of minor body image disorders in groups B and C. Conversely, body image was remarkably altered in groups D and A. Recognizing main MD traits, physical trainers should recommend further psychological counseling. Information should also be provided to gym clients regarding the health risks associated with purgative behaviors, use of steroids, and abuse of food supplements.

  9. A silent period in sural muscle occurring prior to the voluntary forward inclination of the body.

    Science.gov (United States)

    Iwase, Y; Uchida, T; Takanashi, Y; Suzuki, N; Hashimoto, M; Yamamoto, Y; Takegami, T; Koyama, H

    1981-01-20

    A silent period lasting for 300-500 msec was observed in triceps surae muscle when the subject inclined forward from the normal standing. This silent period preceded 100 msec or more the beginning of the body inclination and was terminated by an abrupt refiring in the midst of the body swing. The silence was not preceded by the increase in activity of the sural muscle itself or any other leg muscles studied. H-reflex in soleus was strongly inhibited or disappeared during the silent period, indicating that the excitability of the spinal motoneurons was greatly decreased during this period. These findings suggest that the silent period was not induced by some reflex activity in the spinal cord, but was caused by the inhibitory activity based on a central program on the spinal motoneurons.

  10. Triglycerides in the human kidney cortex: relationship with body size.

    Directory of Open Access Journals (Sweden)

    Ion Alexandru Bobulescu

    Full Text Available Obesity is associated with increased risk for kidney disease and uric acid nephrolithiasis, but the pathophysiological mechanisms underpinning these associations are incompletely understood. Animal experiments have suggested that renal lipid accumulation and lipotoxicity may play a role, but whether lipid accumulation occurs in humans with increasing body mass index (BMI is unknown. The association between obesity and abnormal triglyceride accumulation in non-adipose tissues (steatosis has been described in the liver, heart, skeletal muscle and pancreas, but not in the human kidney. We used a quantitative biochemical assay to quantify triglyceride in normal kidney cortex samples from 54 patients undergoing nephrectomy for localized renal cell carcinoma. In subsets of the study population we evaluated the localization of lipid droplets by Oil Red O staining and measured 16 common ceramide species by mass spectrometry. There was a positive correlation between kidney cortex trigyceride content and BMI (Spearman R = 0.27, P = 0.04. Lipid droplets detectable by optical microscopy had a sporadic distribution but were generally more prevalent in individuals with higher BMI, with predominant localization in proximal tubule cells and to a lesser extent in glomeruli. Total ceramide content was inversely correlated with triglycerides. We postulate that obesity is associated with abnormal triglyceride accumulation (steatosis in the human kidney. In turn, steatosis and lipotoxicity may contribute to the pathogenesis of obesity-associated kidney disease and nephrolithiasis.

  11. Triglycerides in the Human Kidney Cortex: Relationship with Body Size

    Science.gov (United States)

    Bobulescu, Ion Alexandru; Lotan, Yair; Zhang, Jianning; Rosenthal, Tara R.; Rogers, John T.; Adams-Huet, Beverley; Sakhaee, Khashayar; Moe, Orson W.

    2014-01-01

    Obesity is associated with increased risk for kidney disease and uric acid nephrolithiasis, but the pathophysiological mechanisms underpinning these associations are incompletely understood. Animal experiments have suggested that renal lipid accumulation and lipotoxicity may play a role, but whether lipid accumulation occurs in humans with increasing body mass index (BMI) is unknown. The association between obesity and abnormal triglyceride accumulation in non-adipose tissues (steatosis) has been described in the liver, heart, skeletal muscle and pancreas, but not in the human kidney. We used a quantitative biochemical assay to quantify triglyceride in normal kidney cortex samples from 54 patients undergoing nephrectomy for localized renal cell carcinoma. In subsets of the study population we evaluated the localization of lipid droplets by Oil Red O staining and measured 16 common ceramide species by mass spectrometry. There was a positive correlation between kidney cortex trigyceride content and BMI (Spearman R = 0.27, P = 0.04). Lipid droplets detectable by optical microscopy had a sporadic distribution but were generally more prevalent in individuals with higher BMI, with predominant localization in proximal tubule cells and to a lesser extent in glomeruli. Total ceramide content was inversely correlated with triglycerides. We postulate that obesity is associated with abnormal triglyceride accumulation (steatosis) in the human kidney. In turn, steatosis and lipotoxicity may contribute to the pathogenesis of obesity-associated kidney disease and nephrolithiasis. PMID:25170827

  12. Soy germ protein concentrate diet decreased body fat weight and increased hindlimb muscle weight in rats.

    Science.gov (United States)

    Kataoka, Hisashi; Saito, Sanshiro; Itoh, Atsushi; Matsuo, Tatsuhiro

    2012-01-01

    The purpose of this study was to investigate the effects of soy germ protein intake on body composition. Wistar rats were fed experimental diets for 16 weeks. These consisted of soy germ protein, soy protein, or casein. Abdominal adipose tissue weights significantly lower and hindlimb muscle weights were significantly higher in the soy germ protein group than in the casein group.

  13. Erythropoietin treatment enhances muscle mitochondrial capacity in humans

    DEFF Research Database (Denmark)

    Plenge, Ulla; Belhage, Bo; Guadalupe-Grau, Amelia;

    2012-01-01

    Erythropoietin (Epo) treatment has been shown to induce mitochondrial biogenesis in cardiac muscle along with enhanced mitochondrial capacity in mice. We hypothesized that recombinant human Epo (rhEpo) treatment enhances skeletal muscle mitochondrial oxidative phosphorylation (OXPHOS) capacity...... in humans. In six healthy volunteers rhEpo was administered by sub-cutaneous injection over 8 weeks with oral iron (100 mg) supplementation taken daily. Mitochondrial OXPHOS was quantified by high-resolution respirometry in saponin-permeabilized muscle fibers obtained from biopsies of the vastus lateralis...... before and after rhEpo treatment. OXPHOS was determined with the mitochondrial complex I substrates malate, glutamate, pyruvate, and complex II substrate succinate in the presence of saturating ADP concentrations, while maximal electron transport capacity (ETS) was assessed by addition of an uncoupler...

  14. IL-6 selectively stimulates fat metabolism in human skeletal muscle

    DEFF Research Database (Denmark)

    Wolsk, Emil; Mygind, Helene; Grøndahl, Thomas S

    2010-01-01

    Interleukin (IL)-6 is chronically elevated in type 2 diabetes but also during exercise. However, the exact metabolic role, and hence the physiological significance, has not been elucidated. The objective of this study was to investigate the in vivo effect of recombinant human (rh) IL-6 on human fat...... and glucose metabolism and signaling of both adipose tissue and skeletal muscle. Eight healthy postabsorptive males were infused with either rhIL-6 or saline for 4 h, eliciting IL-6 levels of ~40 and ~1 pg/ml, respectively. Systemic, skeletal muscle, and adipose tissue fat and glucose metabolism was assessed...... in systemic lipolysis. Adipose tissue lipolysis and fatty acid kinetics were unchanged with rhIL-6 compared with saline infusion. Conversely, rhIL-6 infusion caused an increase in skeletal muscle unidirectional fatty acid and glycerol release, indicative of an increase in lipolysis. The increased lipolysis...

  15. Single muscle fibre contractile properties differ between body-builders, power athletes and control subjects.

    Science.gov (United States)

    Meijer, J P; Jaspers, R T; Rittweger, J; Seynnes, O R; Kamandulis, S; Brazaitis, M; Skurvydas, A; Pišot, R; Šimunič, B; Narici, M V; Degens, H

    2015-11-01

    What is the central question of this study? Do the contractile properties of single muscle fibres differ between body-builders, power athletes and control subjects? What is the main finding and its importance? Peak power normalized for muscle fibre volume in power athletes is higher than in control subjects. Compared with control subjects, maximal isometric tension (normalized for muscle fibre cross-sectional area) is lower in body-builders. Although this difference may be caused in part by an apparent negative effect of hypertrophy, these results indicate that the training history of power athletes may increase muscle fibre quality, whereas body-building may be detrimental. We compared muscle fibre contractile properties of biopsies taken from the vastus lateralis of 12 body-builders (BBs; low- to moderate-intensity high-volume resistance training), six power athletes (PAs; high-intensity, low-volume combined with aerobic training) and 14 control subjects (Cs). Maximal isotonic contractions were performed in single muscle fibres, typed with SDS-PAGE. Fibre cross-sectional area was 67 and 88% (P power (PP) of PA fibres was 58% higher than that of BB fibres (P < 0.05), whereas BB fibres, despite considerable hypertrophy, had similar PP to the C fibres. This work suggests that high-intensity, low-volume resistance training with aerobic exercise improves PP, while low- to moderate-intensity high-volume resistance training does not affect PP and results in a reduction in specific tension. We postulate that the decrease in specific tension is caused by differences in myofibrillar density and/or post-translational modifications of contractile proteins. © 2015 The Authors. Experimental Physiology © 2015 The Physiological Society.

  16. Analysis of mechanical interaction between human gluteal soft tissue and body supports.

    Science.gov (United States)

    Then, C; Menger, J; Benderoth, G; Alizadeh, M; Vogl, T J; Hübner, F; Silber, G

    2008-01-01

    Pressure sores are the most common complication associated with patient immobilization. They develop through sustained localized tissue strain and stress, primarily caused by body supports. Modifying support design can reduce the risk and extent of pressure sore development with computational simulations helping to provide insight into tissue stress-strain distribution. Appropriate material parameters for human soft tissue and support material, as well as precise anatomical modelling, are indispensable in this process. A finite element (FE) model of the human gluteal region based on magnetic resonance imaging (MRI) data has been developed. In vivo human gluteal skin/fat and muscle long-term material parameters as well as open-cell polyurethane foam support long-term material parameters have been characterised. The Ogden form for slightly compressible materials was employed to describe human gluteal soft tissue behaviour. Altering support geometries and support materials, effects on human gluteal soft tissue could be quantified. FE-analysis indicated maximal tissue stress at the muscle-bone interface, not at the skin. Shear strain maxima were found in the muscle layer near the fat-muscle interface. Maximum compressive stress magnitude at the sacral bone depended strongly on the behaviour of the pelvic diaphragm musculature. We hypothesize that the compliance of the muscles forming the pelvic diaphragm govern the relative motion of the buttock tissue to the adjacent bone structure under compression, thus influencing tissue stress magnitudes.

  17. Changes in joint angle, muscle-tendon complex length, muscle contractile tissue displacement, and modulation of EMG activity during acute whole-body vibration.

    Science.gov (United States)

    Cochrane, Darryl J; Loram, Ian D; Stannard, Stephen R; Rittweger, Jörn

    2009-09-01

    It has been suggested that vibration causes small changes in muscle length, but to the best of our knowledge, these have yet to be demonstrated during whole-body vibration (WBV). This was an observational study to determine whether acute WBV would result in muscle lengthening. We hypothesized that acute WBV would increase electromyography (EMG) activity concurrently with measurable changes in muscle contractile length. Nine healthy males performed two conditions on a Galileo vibration machine for 15 s at 0 HZ (resting) and 6 HZ at a set knee angle of 18 degrees. Muscle tendon complex length, contractile tissue displacement of the medial gastrocnemius muscle, and EMG of soleus, tibialis anterior, and vastus lateralis muscles were measured. At 6 HZ the medial gastrocnemius (MG) muscle tendon complex (MTC) amplitude (375 microm) was significantly greater (P EMG modulation were found for all muscles during the 6 HZ compared to the 0 HZ condition. The major finding was that approximately 50% of the elongation occurred within the muscle itself and was associated with preceding changes in EMG. This indicates muscle lengthening may be a prerequisite for eliciting stretch reflexes. In conclusion, there is a temporal association between EMG activity and muscle contractile tissue displacement where low-frequency WBV results in small muscle length changes and increases muscle activation.

  18. Ultrastructure of interstitial cells of Cajal in circular muscle of human small intestine

    DEFF Research Database (Denmark)

    Rumessen, J J; Mikkelsen, H B; Qvortrup, Klaus;

    1993-01-01

    Interstitial cells of Cajal (ICC) may be important regulatory cells in gut muscle layers. This study examined ICC within the circular muscle of human small intestine.......Interstitial cells of Cajal (ICC) may be important regulatory cells in gut muscle layers. This study examined ICC within the circular muscle of human small intestine....

  19. The accommodative ciliary muscle function is preserved in older humans

    Science.gov (United States)

    Tabernero, Juan; Chirre, Emmanuel; Hervella, Lucia; Prieto, Pedro; Artal, Pablo

    2016-05-01

    Presbyopia, the loss of the eye’s accommodation capability, affects all humans aged above 45–50 years old. The two main reasons for this to happen are a hardening of the crystalline lens and a reduction of the ciliary muscle functionality with age. While there seems to be at least some partial accommodating functionality of the ciliary muscle at early presbyopic ages, it is not yet clear whether the muscle is still active at more advanced ages. Previous techniques used to visualize the accommodation mechanism of the ciliary muscle are complicated to apply in the older subjects, as they typically require fixation stability during long measurement times and/or to have an ultrasound probe directly in contact with the eye. Instead, we used our own developed method based on high-speed recording of lens wobbling to study the ciliary muscle activity in a small group of pseudophakic subjects (around 80 years old). There was a significant activity of the muscle, clearly able to contract under binocular stimulation of accommodation. This supports a purely lenticular-based theory of presbyopia and it might stimulate the search for new solutions to presbyopia by making use of the remaining contraction force still presented in the aging eye.

  20. Impact of Hot and Cold Exposure on Human Skeletal Muscle Gene Expression

    Science.gov (United States)

    Zak, Roksana B.; Shute, Robert J.; Heesch, Matthew W.S.; La Salle, D. Taylor; Bubak, Matthew P.; Dinan, Nicholas E.; Laursen, Terence L.; Slivka, Dustin R.

    2017-01-01

    Many human diseases lead to a loss of skeletal muscle metabolic function and mass. Local and environmental temperature can modulate the exercise-stimulated response of several genes involved in mitochondrial biogenesis and skeletal muscle function in a human model. However, the impact of environmental temperature, independent of exercise, has not been addressed in a human model. Thus, the purpose of this study was to compare the effects of exposure to hot, cold, and room temperature conditions on skeletal muscle gene expression related to mitochondrial biogenesis and muscle mass. METHODS Recreationally trained male subjects (n=12) had muscle biopsies taken from the vastus lateralis before and after 3 h exposure to hot (33 °C), cold (7 °C), or room temperature (20 °C) conditions. RESULTS Temperature had no effect on most of the genes related to mitochondrial biogenesis, myogenesis, or proteolysis (p > 0.05). Core temperature was significantly higher in hot and cold environments compared to room temperature (37.2 ± 0.1 °C, p = 0.001; 37.1 ± 0.1 °C, p = 0.013; 36.9 ± 0.1 °C, respectively). Whole body oxygen consumption was also significantly higher in hot and cold compared to room temperature (0.38 ± 0.01 L·min−1, p < 0.001; 0.52 ± 0.03 L·min−1, p < 0.001; 0.35 ± 0.01 L·min−1, respectively). CONCLUSIONS These data show that acute temperature exposure alone does not elicit significant changes in skeletal muscle gene expression. When considered in conjunction with previous research, exercise appears to be a necessary component to observe gene expression alterations between different environmental temperatures in humans. PMID:28177744

  1. Male Body Image: The Role of Muscle Magazine Exposure, Body Mass Index, and Social Comparison in Men's Body Satisfaction

    National Research Council Canada - National Science Library

    Jonason, Peter K; Krcmar, Marina; Sohn, Steve

    2009-01-01

    ...). However, research on male body image tends to assume that the same theoretical models used to account for body satisfaction in women are appropriate for men (e.g., McCabe & Ricciardelli, 2004...

  2. Physiological characterization of human muscle acetylcholine receptors from ALS patients

    Science.gov (United States)

    Palma, Eleonora; Inghilleri, Maurizio; Conti, Luca; Deflorio, Cristina; Frasca, Vittorio; Manteca, Alessia; Pichiorri, Floriana; Roseti, Cristina; Torchia, Gregorio; Limatola, Cristina; Grassi, Francesca; Miledi, Ricardo

    2011-01-01

    Amyotrophic lateral sclerosis (ALS) is characterized by progressive degeneration of motor neurons leading to muscle paralysis. Research in transgenic mice suggests that the muscle actively contributes to the disease onset, but such studies are difficult to pursue in humans and in vitro models would represent a good starting point. In this work we show that tiny amounts of muscle from ALS or from control denervated muscle, obtained by needle biopsy, are amenable to functional characterization by two different technical approaches: “microtransplantation” of muscle membranes into Xenopus oocytes and culture of myogenic satellite cells. Acetylcholine (ACh)-evoked currents and unitary events were characterized in oocytes and multinucleated myotubes. We found that ALS acetylcholine receptors (AChRs) retain their native physiological characteristics, being activated by ACh and nicotine and blocked by α-bungarotoxin (α-BuTX), d-tubocurarine (dTC), and galantamine. The reversal potential of ACh-evoked currents and the unitary channel behavior were also typical of normal muscle AChRs. Interestingly, in oocytes injected with muscle membranes derived from ALS patients, the AChRs showed a significant decrease in ACh affinity, compared with denervated controls. Finally, riluzole, the only drug currently used against ALS, reduced, in a dose-dependent manner, the ACh-evoked currents, indicating that its action remains to be fully characterized. The two methods described here will be important tools for elucidating the role of muscle in ALS pathogenesis and for developing drugs to counter the effects of this disease. PMID:22128328

  3. Differential activation of sympathetic discharge to skin and skeletal muscle in humans.

    Science.gov (United States)

    Vissing, S F

    1997-01-01

    The present work provides insight into the relative contribution of different mechanisms in regulating sympathetic discharge to skin and skeletal muscle in humans. Activation of sympathetic nerve activity during common behaviours such as orthostasis and exercise was shown to be highly selective, depending on the specific sympathetic outflow under study. Regarding orthostasis, data from experiments in this thesis revoked the concept that cardiopulmonary afferents only regulate muscle vascular resistance in the forearm, not in the leg. Also the concept that the cutaneous circulation is under baroreceptor control has been challenged. Unloading cardiopulmonary afferents with lower body negative pressure elicited intensity dependent increases in peroneal sympathetic discharge to skeletal muscle, and increases in forearm and calf vascular resistances. Therefore, it was concluded that cardiopulmonary afferents regulate vascular resistance in skeletal muscle of both forearm and calf, suggesting an important role for these afferents in the reflex adjustments to upright posture. In contrast to muscle sympathetic nerve activity, baroreceptor deactivation with lower body negative pressure had no effect on skin sympathetic nerve activity or skin vascular resistance. However, assumption of upright posture increased skin vascular resistance, this increase was abolished when increased vascular transmural pressure was avoided by elevating the arm. Local cutaneous nerve blockade, but not blockade of efferent sympathetic nerve traffic, abolished the vasoconstrictor response to upright posture. Based on these experiments, it was concluded that baroreceptor afferents do not regulate sympathetic vasoconstrictor outflow to the cutaneous circulation. During upright posture at normothermia cutaneous vasoconstriction is mainly driven by a local reflex. To explain activation of sympathetic outflow during exercise two theories have been proposed. One is that a "central motor command" signal

  4. Origins and early development of human body knowledge.

    Science.gov (United States)

    Slaughter, Virginia; Heron, Michelle

    2004-01-01

    As a knowable object, the human body is highly complex. Evidence from several converging lines of research, including psychological studies, neuroimaging and clinical neuropsychology, indicates that human body knowledge is widely distributed in the adult brain, and is instantiated in at least three partially independent levels of representation. Sensorimotor body knowledge is responsible for on-line control and movement of one's own body and may also contribute to the perception of others' moving bodies; visuo-spatial body knowledge specifies detailed structural descriptions of the spatial attributes of the human body; and lexical-semantic body knowledge contains language-based knowledge about the human body. In the first chapter of this Monograph, we outline the evidence for these three hypothesized levels of human body knowledge, then review relevant literature on infants' and young children's human body knowledge in terms of the three-level framework. In Chapters II and III, we report two complimentary series of studies that specifically investigate the emergence of visuo-spatial body knowledge in infancy. Our technique is to compare infants'responses to typical and scrambled human bodies, in order to evaluate when and how infants acquire knowledge about the canonical spatial layout of the human body. Data from a series of visual habituation studies indicate that infants first discriminate scrambled from typical human body picture sat 15 to 18 months of age. Data from object examination studies similarly indicate that infants are sensitive to violations of three-dimensional human body stimuli starting at 15-18 months of age. The overall pattern of data supports several conclusions about the early development of human body knowledge: (a) detailed visuo-spatial knowledge about the human body is first evident in the second year of life, (b) visuo-spatial knowledge of human faces and human bodies are at least partially independent in infancy and (c) infants' initial

  5. Re-evaluation of sarcolemma injury and muscle swelling in human skeletal muscles after eccentric exercise.

    Science.gov (United States)

    Yu, Ji-Guo; Liu, Jing-Xia; Carlsson, Lena; Thornell, Lars-Eric; Stål, Per S

    2013-01-01

    The results regarding the effects of unaccustomed eccentric exercise on muscle tissue are often conflicting and the aetiology of delayed onset muscle soreness (DOMS) induced by eccentric exercise is still unclear. This study aimed to re-evaluate the paradigm of muscular alterations with regard to muscle sarcolemma integrity and fibre swelling in human muscles after voluntary eccentric exercise leading to DOMS. Ten young males performed eccentric exercise by downstairs running. Biopsies from the soleus muscle were obtained from 6 non-exercising controls, 4 exercised subjects within 1 hour and 6 exercised subjects at 2-3 days and 7-8 days after the exercise. Muscle fibre sarcolemma integrity, infiltration of inflammatory cells and changes in fibre size and fibre phenotype composition as well as capillary supply were examined with specific antibodies using enzyme histochemistry and immunohistochemistry. Although all exercised subjects experienced DOMS which peaked between 1.5 to 2.5 days post exercise, no significant sarcolemma injury or inflammation was detected in any post exercise group. The results do not support the prevailing hypothesis that eccentric exercise causes an initial sarcolemma injury which leads to subsequent inflammation after eccentric exercise. The fibre size was 24% larger at 7-8 days than at 2-3 days post exercise (pexercise (lower in 5 of the 6 subjects at 7-8 days than at 2-3 days; pexercise was interpreted to reflect fibre swelling. Because the fibre swelling did not appear at the time that DOMS peaked (between 1.5 to 2.5 days post exercise), we concluded that fibre swelling in the soleus muscle is not directly associated with the symptom of DOMS.

  6. Clinical Muscle Testing Compared with Whole-Body Magnetic Resonance Imaging in Facio-scapulo-humeral Muscular Dystrophy.

    Science.gov (United States)

    Regula, J U; Jestaedt, L; Jende, F; Bartsch, A; Meinck, H-M; Weber, M-A

    2016-12-01

    The objective of this study was to evaluate the clinical usefulness of whole-body magnetic resonance imaging (MRI) in facio-scapulo-humeral muscular dystrophy (FSHD). In 20 patients with genetically proven FSHD1, we prospectively assessed muscular involvement and correlated the results of semi-quantitative manual muscle testing and other parameters such as disease duration, creatine kinase (CK) levels and repeat length of the D4Z4 locus with whole-body MRI. Clinical muscle testing revealed the trapezius, pectoralis and infraspinatus as the most severely affected muscles in the shoulder, and the knee flexors and gluteus medius in the hip girdle. MRI revealed the trapezius and serratus anterior muscles in the shoulder, and the hamstrings and adductor muscles in the hip girdle, as the most severely affected muscle groups. Overall, degrees of fatty degeneration on MRI scans correlated significantly with clinical weakness. Moreover, we could detect clear affection of the trunk muscles. Corresponding to earlier reports, asymmetric involvement was frequent in both clinical examination and MRI scoring. Moreover, MRI revealed inhomogeneous muscle degeneration in a considerable proportion of both, muscles and patients. Both clinical and MRI scores significantly correlated to disease duration, but not to fragment size or CK levels. Fatty degeneration in whole-body MRI correlates well to clinical muscle testing of the extremities but gives more information on deeper or trunk muscles. It shows structural changes in muscular disorders and may become an excellent tool for assessment of muscle involvement and follow-up studies.

  7. Pericapillary basement membrane thickening in human skeletal muscles.

    Science.gov (United States)

    Baum, Oliver; Bigler, Marius

    2016-09-01

    The basement membrane (BM) surrounding capillaries in skeletal muscles varies physiologically in thickness according to age, physical fitness, and anatomical site in humans. Furthermore, the pericapillary BM thickness (CBMT) increases pathophysiologically during several common disease states, including peripheral arterial disease and diabetes mellitus. This review on CBM thickening in human skeletal muscles is two pronged. First, it addresses the advantages/disadvantages of grid- and tablet-based measuring and morphometric techniques that are implemented to assess the CBMT on transmission electron micrographs. Second, it deals with the biology of CBM thickening in skeletal muscles, particularly its possible causes, molecular mechanisms, and functional impact. CBM thickening is triggered by several physical factors, including diabetes-associated glycation, hydrostatic pressure, and inflammation. Increased biosynthesis of type IV collagen expression or repetitive cycles in pericyte or endothelial cell degeneration/proliferation appear to be most critical for CBM accumulation. A thickened CBM obviously poses a greater barrier for diffusion, lowers the microvascular elasticity, and impedes transcytosis of inflammatory cells. Our own morphometric data reveal the CBM enlargement to be not accompanied by the pericyte coverage. Owing to an overlap or redundancy in the capillary supply, CBM thickening in skeletal muscles might not be such a devastating occurrence as in organs with endarterial circulation (e.g., kidney and retina). CBM growth in skeletal muscles can be reversed by training or administration of antidiabetic drugs. In conclusion, CBM thickening in skeletal muscles is a microvascular remodeling process by which metabolic, hemodynamic, and inflammatory forces are integrated together and which could play a hitherto underestimated role in etiology/progression of human diseases.

  8. Enhanced Muscle Afferent Signals during Motor Learning in Humans.

    Science.gov (United States)

    Dimitriou, Michael

    2016-04-25

    Much has been revealed concerning human motor learning at the behavioral level [1, 2], but less is known about changes in the involved neural circuits and signals. By examining muscle spindle responses during a classic visuomotor adaptation task [3-6] performed by fully alert humans, I found substantial modulation of sensory afferent signals as a function of adaptation state. Specifically, spindle control was independent of concurrent muscle activity but was specific to movement direction (representing muscle lengthening versus shortening) and to different stages of learning. Increased spindle afferent responses to muscle stretch occurring early during learning reflected individual error size and were negatively related to subsequent antagonist activity (i.e., 60-80 ms thereafter). Relative increases in tonic afferent output early during learning were predictive of the subjects' adaptation rate. I also found that independent spindle control during sensory realignment (the "washout" stage) induced afferent signal "linearization" with respect to muscle length (i.e., signals were more tuned to hand position). The results demonstrate for the first time that motor learning also involves independent and state-related modulation of sensory mechanoreceptor signals. The current findings suggest that adaptive motor performance also relies on the independent control of sensors, not just of muscles. I propose that the "γ" motor system innervating spindles acts to facilitate the acquisition and extraction of task-relevant information at the early stages of sensorimotor adaptation. This designates a more active and targeted role for the human proprioceptive system during motor learning.

  9. Muscle strength, body composition, and performance of an elite shot-putter.

    Science.gov (United States)

    Terzis, Gerasimos; Kyriazis, Thomas; Karampatsos, Giorgos; Georgiadis, Giorgos

    2012-12-01

    Although muscle mass and strength are thought to be closely related to throwing performance, there are few scientific data about these parameters in elite shot-putters. The purpose of this case report was to present longitudinal data for muscle strength and body composition in relation to performance of an elite male shot-putter. A male national champion with the best rotational shot-put performance of 20.36 m (in 2010) was followed from 2003 to 2011 (current age: 29 y). Data regarding body composition (dual X-ray absorptiometry), as well as 1-repetition-maximum muscle strength (bench press, squat, snatch) and rotational shot-put performance, were collected every February for the last 9 y, 4 wk before the national indoor championship event. The athlete's personal-best performances in squat, bench press, and snatch were 175 kg, 210 kg, and 112.5 kg, respectively. His peak total lean body mass was 92.4 kg, bone mineral density 1.55 g/cm2, and lowest body fat 12.9%. His shot-put performance over these 9 years was significantly correlated with 1-repetition-maximum squat strength (r = .93, P snatch (r = .92, P < .01). In contrast, shot-put performance was not significantly correlated with any of the body-composition parameters. The results of this case study suggest that elite rotational shot-put performance may not be directly correlated with lean body mass. Instead, it seems that it is closely related with measures of muscle strength.

  10. Consequences of prolonged total body immersion in cold water on muscle performance and EMG activity.

    Science.gov (United States)

    Coulange, Mathieu; Hug, François; Kipson, Nathalie; Robinet, Claude; Desruelle, Anne Virginie; Melin, Bruno; Jimenez, Chantal; Galland, François; Jammes, Yves

    2006-04-01

    The consequences of a prolonged total body immersion in cold water on the muscle function have not been documented yet, and they are the object of this French Navy research program. Ten elite divers were totally immerged and stayed immobile during 6 h in cold (18 and 10 degrees C) water. We measured the maximal voluntary leg extension (maximal voluntary contraction, MVC) and evoked compound muscle potential (M wave) in vastus lateralis and soleus muscles at rest, after a submaximal (60% MVC) isometric extension allowing the measurement of the endurance time (Tlim). The power spectrum of surface electromyograms (EMG) was computed during 60% MVCs. MVCs and 60% MVC maneuvers were repeated four times during the immersion. Data were compared with those obtained in a control group studied in dry air condition during a 6-h session. Total body cooling did not affect MVC nor Tlim. The M wave duration increased in the coolest muscle (soleus), but only at 10 degrees C at rest. There were no further fatigue-induced M wave alterations in both muscles. During 60% the MVCs, a time-dependant increase in the leftward shift of the EMG spectrum occurred at the two temperatures. These EMG changes were absent in the control group of subjects studied in dry air. The plasma lactate concentration was elevated throughout the 18 and mostly the 10 degrees C immersion conditions. Throughout the 18 degrees C immersion study, the resting potassium level did not significantly vary, whereas at 10 degrees C, a significant potassium increase occurred soon and persisted throughout the study. Thus, total body immersion in cold water did not affect the global contractile properties of leg muscles during static efforts but elicited significant alterations in electromyographic events which may be related to the variations of interstitial fluid composition.

  11. Effect of creatine supplementation during rapid body mass reduction on metabolism and isokinetic muscle performance capacity.

    Science.gov (United States)

    Oöpik, V; Pääsuke, M; Timpmann, S; Medijainen, L; Ereline, J; Smirnova, T

    1998-06-01

    Well-trained subjects (n = 6) were studied before and after losing a mean 3.0%-4.3% of body mass to determine whether muscle performance could be maintained or even enhanced by dietary creatine supplementation. During a 5-day period of loss of mass the subjects were randomly assigned to a creatine or placebo supplemented diet. All the subjects were measured before and after loss of mass on both supplements for isokinetic peak torque (PT) and work at peak torque (W(PT)) of knee extensors, also for intermittent high intensity working capacity of the same muscle group. The latter test consisted of submaximal isokinetic knee extensions at an angular velocity of 1.57 rad x s(-1) for 45 s at the rate of 30 contractions each min (submaximal work, Ws max) followed by 15-s maximal effort (maximal work, Wmax). Total duration of the test was 3 min. Haematocrit was measured and haemoglobin, ammonia, lactate, glucose and urea concentrations were analysed in blood samples obtained at rest and after cessation of muscle performance tests. The results indicated that creatine supplementation in comparison with placebo treatment during rapid body mass reduction may help to maintain muscle PT and W(PT)1 at high angular velocities, not influencing Wmax and the rate of fatigue development during Wmax, but affecting adversely Ws max. Within the limitations of the present study the reasons for the partially detrimental effect of creatine administration remain obscure, but it is suggested that impaired creatine uptake in muscle during body mass loss as well as creatine induced changes in muscle glucose and glycogen metabolism may be involved.

  12. Total-body skeletal muscle mass determination by D3-creatine dilution in mice

    Directory of Open Access Journals (Sweden)

    Yue-bing WANG

    2017-08-01

    Full Text Available Objective To investigate the potentiality of D3-creatine dilution method to be used in detection of skeletal muscle mass, so as to provide a new method for skeletal muscle mass detection in mice. Methods Four weeks, 10 weeks and 13 months old male C57BL/6 mice (10 each were used in the present study. All mice were fed with a single dose of D3-creatine (2mg/kg after testing body composition by EchoMRITM. Urine was collected at 24h, 48h and 72h after creatine administration, and analyzed by liquid chromatography-tandem mass spectrometry mass spectrometry (LC-MS/MS that was used to determine the creatine pool size. The relationship between creatine pool size and the skeletal muscle mass determined by EchoMRITM was analyzed. Results Both lean body mass and total creatine pool size were aged mice > adult mice > juvenile mice. There was a significant correlation (r=0.687, P=0.000 between the lean body mass measured by EchoMRITM and the total creatine pool size calculated by D3-creatine dilution method. Conclusion The D3-creatine dilution method may be used to determine the skeletal muscle mass of mice. DOI: 10.11855/j.issn.0577-7402.2017.07.10

  13. Erythropoietin treatment enhances mitochondrial function in human skeletal muscle

    Directory of Open Access Journals (Sweden)

    Ulla ePlenge

    2012-03-01

    Full Text Available Abstract Erythropoietin (Epo treatment has been shown to induce mitochondrial biogenesis in cardiac muscle along with enhanced mitochondrial capacity in mice. We hypothesized that recombinant human Epo (rhEpo treatment enhances skeletal muscle mitochondrial oxidative phosphorylation (OXPHOS capacity in humans. In six healthy volunteers rhEpo was administered by sub-cutaneous injection over eight weeks with oral iron (100 mg supplementation taken daily. Mitochondrial OXPHOS was quantified by high-resolution respirometry in saponin-permeabilized muscle fibers obtained from biopsies of the vastus lateralis before and after rhEpo treatment. OXPHOS was determined with the mitochondrial complex I substrates malate, glutamate, pyruvate and complex II substrate succinate in the presence of saturating ADP concentrations, while maximal electron transport capacity (ETS was assessed by addition of an uncoupler. rhEpo treatment increased OXPHOS (from 92±5 to 113±7 pmol.sec-1.mg-1 and ETS (107±4 to 143±14 pmol.sec-1.mg-1, P<0.05, demonstrating that Epo treatment induces an upregulation of OXPHOS and ETS in human skeletal muscle.

  14. Human Body Image Edge Detection Based on Wavelet Transform

    Institute of Scientific and Technical Information of China (English)

    李勇; 付小莉

    2003-01-01

    Human dresses are different in thousands way.Human body image signals have big noise, a poor light and shade contrast and a narrow range of gray gradation distribution. The application of a traditional grads method or gray method to detect human body image edges can't obtain satisfactory results because of false detections and missed detections. According to tte peculiarity of human body image, dyadic wavelet transform of cubic spline is successfully applied to detect the face and profile edges of human body image and Mallat algorithm is used in the wavelet decomposition in this paper.

  15. Effect of whole body vibration exercise on muscle strength and proprioception in females with knee osteoarthritis

    DEFF Research Database (Denmark)

    Trans, T; Aaboe, J; Henriksen, M

    2009-01-01

    The purpose of this study was to assess the effect of whole body vibration (WBV) exercise on muscle strength and proprioception in female patients with osteoarthritis in the knee (knee-OA). A single blinded, randomised, controlled trial was performed in an outpatient clinic on 52 female patients...... groups trained twice a week for 8 weeks, with a progressively increasing intensity. The WBV groups performed unloaded static WBV exercise. The following were measured: knee muscle strength (extension/flexion) and proprioception (threshold for detection of passive movement (TDPM)). Self-reported disease...

  16. Investigation of galvanic-coupled intrabody communication using the human body circuit model.

    Science.gov (United States)

    Kibret, Behailu; Seyedi, MirHojjat; Lai, Daniel T H; Faulkner, Micheal

    2014-07-01

    Intrabody Communication (IBC) is a technique that uses the human body as a transmission medium for electrical signals to connect wearable electronic sensors and devices. Understanding the human body as the transmission medium in IBC paves way for practical implementation of IBC in body sensor networks. In this study, we propose a model for galvanic coupling-type IBC based on a simplified equivalent circuit representation of the human upper arm. We propose a new way to calculate the electrode-skin contact impedance. Based on the model and human experimental results, we discuss important characteristics of galvanic coupling-type IBC, namely, the effect of tissues, anthropometry of subjects, and electrode configuration on signal propagation. We found that the dielectric properties of the muscle primarily characterize the received signal when receiver electrodes are located close to transmitter electrodes. When receiver and transmitter electrodes are far apart, the skin dielectric property affects the received signal.

  17. The relationship between human skeletal muscle pyruvate dehydrogenase phosphatase activity and muscle aerobic capacity.

    Science.gov (United States)

    Love, Lorenzo K; LeBlanc, Paul J; Inglis, J Greig; Bradley, Nicolette S; Choptiany, Jon; Heigenhauser, George J F; Peters, Sandra J

    2011-08-01

    Pyruvate dehydrogenase (PDH) is a mitochondrial enzyme responsible for regulating the conversion of pyruvate to acetyl-CoA for use in the tricarboxylic acid cycle. PDH is regulated through phosphorylation and inactivation by PDH kinase (PDK) and dephosphorylation and activation by PDH phosphatase (PDP). The effect of endurance training on PDK in humans has been investigated; however, to date no study has examined the effect of endurance training on PDP in humans. Therefore, the purpose of this study was to examine differences in PDP activity and PDP1 protein content in human skeletal muscle across a range of muscle aerobic capacities. This association is important as higher PDP activity and protein content will allow for increased activation of PDH, and carbohydrate oxidation. The main findings of this study were that 1) PDP activity (r(2) = 0.399, P = 0.001) and PDP1 protein expression (r(2) = 0.153, P = 0.039) were positively correlated with citrate synthase (CS) activity as a marker for muscle aerobic capacity; 2) E1α (r(2) = 0.310, P = 0.002) and PDK2 protein (r(2) = 0.229, P =0.012) are positively correlated with muscle CS activity; and 3) although it is the most abundant isoform, PDP1 protein content only explained ∼ 18% of the variance in PDP activity (r(2) = 0.184, P = 0.033). In addition, PDP1 in combination with E1α explained ∼ 38% of the variance in PDP activity (r(2) = 0.383, P = 0.005), suggesting that there may be alternative regulatory mechanisms of this enzyme other than protein content. These data suggest that with higher muscle aerobic capacity (CS activity) there is a greater capacity for carbohydrate oxidation (E1α), in concert with higher potential for PDH activation (PDP activity).

  18. A muscle stem cell for every muscle: variability of satellite cell biology among different muscle groups

    Directory of Open Access Journals (Sweden)

    Matthew Emerson Randolph

    2015-10-01

    Full Text Available The human body contains approximately 640 individual skeletal muscles. Despite the fact that all of these muscles are composed of striated muscle tissue, the biology of these muscles and their associated muscle stem cell populations are quite diverse. Skeletal muscles are affected differentially by various muscular dystrophies, such that certain genetic mutations specifically alter muscle function in only a subset of muscles. Additionally, defective muscle stem cells have been implicated in the pathology of some muscular dystrophies. The biology of muscle stem cells varies depending on their embryologic origins and the muscles with which they are associated. Here we review the biology of skeletal muscle stem cell populations of eight different muscle groups. Understanding the biological variation of skeletal muscles and their resident stem cells could provide valuable insight into mechanisms underlying the susceptibility of certain muscles to myopathic disease.

  19. Regional Differences in Muscle Energy Metabolism in Human Muscle by 31P-Chemical Shift Imaging.

    Science.gov (United States)

    Kime, Ryotaro; Kaneko, Yasuhisa; Hongo, Yoshinori; Ohno, Yusuke; Sakamoto, Ayumi; Katsumura, Toshihito

    2016-01-01

    Previous studies have reported significant region-dependent differences in the fiber-type composition of human skeletal muscle. It is therefore hypothesized that there is a difference between the deep and superficial parts of muscle energy metabolism during exercise. We hypothesized that the inorganic phosphate (Pi)/phosphocreatine (PCr) ratio of the superficial parts would be higher, compared with the deep parts, as the work rate increases, because the muscle fiber-type composition of the fast-type may be greater in the superficial parts compared with the deep parts. This study used two-dimensional 31Phosphorus Chemical Shift Imaging (31P-CSI) to detect differences between the deep and superficial parts of the human leg muscles during dynamic knee extension exercise. Six healthy men participated in this study (age 27±1 year, height 169.4±4.1 cm, weight 65.9±8.4 kg). The experiments were carried out with a 1.5-T superconducting magnet with a 5-in. diameter circular surface coil. The subjects performed dynamic one-legged knee extension exercise in the prone position, with the transmit-receive coil placed under the right quadriceps muscles in the magnet. The subjects pulled down an elastic rubber band attached to the ankle at a frequency of 0.25, 0.5 and 1 Hz for 320 s each. The intracellular pH (pHi) was calculated from the median chemical shift of the Pi peak relative to PCr. No significant difference in Pi/PCr was observed between the deep and the superficial parts of the quadriceps muscles at rest. The Pi/PCr of the superficial parts was not significantly increased with increasing work rate. Compared with the superficial areas, the Pi/PCr of the deep parts was significantly higher (p<0.05) at 1 Hz. The pHi showed no significant difference between the two parts. These results suggest that muscle oxidative metabolism is different between deep and superficial parts of quadriceps muscles during dynamic exercise.

  20. Intermuscular force transmission between human plantarflexor muscles in vivo

    DEFF Research Database (Denmark)

    Bojsen-Møller, Jens; Bojsen-Møller, Jens; Schwartz, Sidse;

    2010-01-01

    of the present study was to investigate if intermuscular force transmission occurs within and between human plantarflexor muscles in vivo. Seven subjects performed four types of either active contractile tasks or passive joint manipulations: passive knee extension, voluntary isometric plantarflexion, voluntary...... isometric hallux flexion, passive hallux extension, and selective percutaneous stimulation of the gastrocnemius medialis (MG). In each experiment plantar- and hallux flexion force and corresponding EMG activity were sampled. During all tasks ultrasonography was applied at proximal and distal sites to assess...... task-induced tissue displacement (which is assumed to represent loading) for the plantarflexor muscles [MG, soleus (SOL), and flexor hallucis longus (FHL)]. Selective MG stimulation and passive knee extension resulted in displacement of both the MG and SOL muscles. Minimal displacement of the triceps...

  1. Human body composition models and methodology: theory and experiment.

    NARCIS (Netherlands)

    Wang, Z.M.

    1997-01-01

    The study of human body composition is a branch of human biology which focuses on the in vivo quantification of body components, the quantitative relationships between components, and the quantitative changes in these components related to various influencing factors. Accordingly, the study of human

  2. Specificity of insulin signalling in human skeletal muscle as revealed by small interfering RNA.

    Science.gov (United States)

    Krook, A; Zierath, J R

    2009-07-01

    Insulin action on metabolically active tissues is a complex process involving positive and negative feedback regulation to control whole body glucose homeostasis. At the cellular level, glucose and lipid metabolism, as well as protein synthesis, are controlled through canonical insulin signalling cascades. The discovery of small interfering RNA (siRNA) allows for the molecular dissection of critical components of the regulation of metabolic and gene regulatory events in insulin-sensitive tissues. The application of siRNA to tissues of human origin allows for the molecular dissection of the mechanism(s) regulating glucose and lipid metabolism. Penetration of the pathways controlling insulin action in human tissue may aid in discovery efforts to develop diabetes prevention and treatment strategies. This review will focus on the use of siRNA to validate critical regulators controlling insulin action in human skeletal muscle, a key organ important for the control of whole body insulin-mediated glucose uptake and metabolism.

  3. Mechanical stimulation improves tissue-engineered human skeletal muscle

    Science.gov (United States)

    Powell, Courtney A.; Smiley, Beth L.; Mills, John; Vandenburgh, Herman H.

    2002-01-01

    Human bioartificial muscles (HBAMs) are tissue engineered by suspending muscle cells in collagen/MATRIGEL, casting in a silicone mold containing end attachment sites, and allowing the cells to differentiate for 8 to 16 days. The resulting HBAMs are representative of skeletal muscle in that they contain parallel arrays of postmitotic myofibers; however, they differ in many other morphological characteristics. To engineer improved HBAMs, i.e., more in vivo-like, we developed Mechanical Cell Stimulator (MCS) hardware to apply in vivo-like forces directly to the engineered tissue. A sensitive force transducer attached to the HBAM measured real-time, internally generated, as well as externally applied, forces. The muscle cells generated increasing internal forces during formation which were inhibitable with a cytoskeleton depolymerizer. Repetitive stretch/relaxation for 8 days increased the HBAM elasticity two- to threefold, mean myofiber diameter 12%, and myofiber area percent 40%. This system allows engineering of improved skeletal muscle analogs as well as a nondestructive method to determine passive force and viscoelastic properties of the resulting tissue.

  4. Mechanical stimulation improves tissue-engineered human skeletal muscle

    Science.gov (United States)

    Powell, Courtney A.; Smiley, Beth L.; Mills, John; Vandenburgh, Herman H.

    2002-01-01

    Human bioartificial muscles (HBAMs) are tissue engineered by suspending muscle cells in collagen/MATRIGEL, casting in a silicone mold containing end attachment sites, and allowing the cells to differentiate for 8 to 16 days. The resulting HBAMs are representative of skeletal muscle in that they contain parallel arrays of postmitotic myofibers; however, they differ in many other morphological characteristics. To engineer improved HBAMs, i.e., more in vivo-like, we developed Mechanical Cell Stimulator (MCS) hardware to apply in vivo-like forces directly to the engineered tissue. A sensitive force transducer attached to the HBAM measured real-time, internally generated, as well as externally applied, forces. The muscle cells generated increasing internal forces during formation which were inhibitable with a cytoskeleton depolymerizer. Repetitive stretch/relaxation for 8 days increased the HBAM elasticity two- to threefold, mean myofiber diameter 12%, and myofiber area percent 40%. This system allows engineering of improved skeletal muscle analogs as well as a nondestructive method to determine passive force and viscoelastic properties of the resulting tissue.

  5. Passive heat acclimation improves skeletal muscle contractility in humans.

    Science.gov (United States)

    Racinais, S; Wilson, M G; Périard, J D

    2017-01-01

    The aim of this study was to investigate the effect of repeated passive heat exposure (i.e., acclimation) on muscle contractility in humans. Fourteen nonheat-acclimated males completed two trials including electrically evoked twitches and voluntary contractions in thermoneutral conditions [Cool: 24°C, 40% relative humidity (RH)] and hot ambient conditions in the hyperthermic state (Hot: 44-50°C, 50% RH) on consecutive days in a counterbalanced order. Rectal temperature was ~36.5°C in Cool and was maintained at ~39°C throughout Hot. Both trials were repeated after 11 days of passive heat acclimation (1 h per day, 48-50°C, 50% RH). Heat acclimation decreased core temperature in Cool (-0.2°C, P heat acclimation improved skeletal muscle contractility as evidenced by an increase in evoked peak twitch amplitude both in Cool (20.5 ± 3.6 vs. 22.0 ± 4.0 N·m) and Hot (20.5 ± 4.7 vs. 22.0 ± 4.0 N·m) (+9%, P heat acclimation improves skeletal muscle contractile function during electrically evoked and voluntary muscle contractions of different intensities both in Cool and Hot. These results suggest that repeated heat exposure may have important implications to passively maintain or even improve muscle function in a variety of performance and clinical settings. Copyright © 2017 the American Physiological Society.

  6. Purinergic effects on Na,K-ATPase activity differ in rat and human skeletal muscle

    DEFF Research Database (Denmark)

    Juel, Carsten; Nordsborg, Nikolai Baastrup; Bangsbo, Jens

    2014-01-01

    P2Y receptor activation may link the effect of purines to increased maximal in vitro activity of the Na,K-ATPase in rat muscle. The hypothesis that a similar mechanism is present in human skeletal muscle was investigated with membranes from rat and human skeletal muscle.......P2Y receptor activation may link the effect of purines to increased maximal in vitro activity of the Na,K-ATPase in rat muscle. The hypothesis that a similar mechanism is present in human skeletal muscle was investigated with membranes from rat and human skeletal muscle....

  7. Transcriptome-scale similarities between mouse and human skeletal muscles with normal and myopathic phenotypes

    Directory of Open Access Journals (Sweden)

    Kang Peter B

    2006-03-01

    Full Text Available Abstract Background Mouse and human skeletal muscle transcriptome profiles vary by muscle type, raising the question of which mouse muscle groups have the greatest molecular similarities to human skeletal muscle. Methods Orthologous (whole, sub- transcriptome profiles were compared among four mouse-human transcriptome datasets: (M six muscle groups obtained from three mouse strains (wildtype, mdx, mdx5cv; (H1 biopsied human quadriceps from controls and Duchenne muscular dystrophy patients; (H2 four different control human muscle types obtained at autopsy; and (H3 12 different control human tissues (ten non-muscle. Results Of the six mouse muscles examined, mouse soleus bore the greatest molecular similarities to human skeletal muscles, independent of the latters' anatomic location/muscle type, disease state, age and sampling method (autopsy versus biopsy. Significant similarity to any one mouse muscle group was not observed for non-muscle human tissues (dataset H3, indicating this finding to be muscle specific. Conclusion This observation may be partly explained by the higher type I fiber content of soleus relative to the other mouse muscles sampled.

  8. Interleukin-6 release is higher across arm than leg muscles during whole-body exercise

    DEFF Research Database (Denmark)

    Helge, Jørn W; Klein, Ditte K; Andersen, Thor Munch

    2011-01-01

    Exercising muscle releases interleukin-6 (IL-6), but the mechanisms controlling this process are poorly understood. This study was performed to test the hypothesis that the IL-6 release differs in arm and leg muscle during whole-body exercise, owing to differences in muscle metabolism. Sixteen...... lateralis and deltoideus. During exercise, IL-6 release was similar between men and women and higher (P 12 ng min(-1) (kg lean limb mass)(-1), respectively). Blood flow (425 ± 36 and 554 ± 35 ml min(-1) (kg lean limb mass)(-1)) and fatty acid uptake (26...... ± 7 and 47 ± 7 µmol min(-1) (kg lean limb mass)(-1)) were lower, glucose uptake similar (51 ± 12 and 41 ± 8 mmol min(-1) (kg lean limb mass)(-1)) and lactate release higher (82 ± 32 and -2 ± 12 µmol min(-1) (kg lean limb mass)(-1)) in arms than legs, respectively, during exercise (P

  9. Auto-measuring System of 3- Dimensional Human Body

    Institute of Scientific and Technical Information of China (English)

    李勇; 尚保平; 付小莉; 尚会超

    2001-01-01

    To realize the automation of fashion industry measuring,designing and manufacturing, the auto-measurement of 3D size of human body is of great importance. The auto measurement system of 3D human body based on Charge Coupled Devices (CCD) and infrared sensors is presented in this paper. The system can measure the bare size of human body that excludes the effect of clothing quickly and accurately.

  10. Carotid baroreceptor-muscle sympathetic relation in humans.

    Science.gov (United States)

    Rea, R F; Eckberg, D L

    1987-12-01

    The purpose of this study was to define the relation between carotid distending pressure and muscle sympathetic activity in humans. Carotid baroreceptors of nine healthy subjects were compressed or stretched for 5 s with graded neck pressure or suction (+40 to -65 mmHg), and muscle sympathetic nerve activity was recorded. The results delineate several features of human baroreflex function. First, the carotid-muscle sympathetic relation is well described by an inverse sigmoid function. Second, a linear relation exists between carotid distending pressure and sympathetic outflow over a range of approximately 25 mmHg. Third, sympathetic responses to changes of carotid pressures are asymmetric; increases of sympathetic activity during carotid compression are much greater than reductions of sympathetic activity during carotid stretch. Fourth, at rest, normal subjects operate near the threshold level for sympathetic excitation. Thus the carotid-muscle sympathetic baroreflex is poised to oppose reductions more effectively than elevations of arterial pressure, and the range of pressures over which the reflex is active is wider than thought hitherto.

  11. Mathematical description of human body constitution and fatness.

    Science.gov (United States)

    Sheikh-Zade, Yu R; Galenko-Yaroshevskii, P A; Cherednik, I L

    2014-02-01

    Using mathematical modeling of human body, we demonstrated logical drawbacks of body mass index (BMI1 = M/H(2); A. Quetelet, 1832) and proposed more precise body mass index (BMI2 = M/H(3)) as well as body constitution index (BCI = (M/H(3))(1/2)) and fatness index (FI = M/HC(2)), where M, H, and C are body weight, height, and wrist circumference of the individual.

  12. Morphometric and Statistical Analysis of the Palmaris Longus Muscle in Human and Non-Human Primates

    Directory of Open Access Journals (Sweden)

    Roqueline A. G. M. F. Aversi-Ferreira

    2014-01-01

    Full Text Available The palmaris longus is considered a phylogenetic degenerate metacarpophalangeal joint flexor muscle in humans, a small vestigial forearm muscle; it is the most variable muscle in humans, showing variation in position, duplication, slips and could be reverted. It is frequently studied in papers about human anatomical variations in cadavers and in vivo, its variation has importance in medical clinic, surgery, radiological analysis, in studies about high-performance athletes, in genetics and anthropologic studies. Most studies about palmaris longus in humans are associated to frequency or case studies, but comparative anatomy in primates and comparative morphometry were not found in scientific literature. Comparative anatomy associated to morphometry of palmaris longus could explain the degeneration observed in this muscle in two of three of the great apes. Hypothetically, the comparison of the relative length of tendons and belly could indicate the pathway of the degeneration of this muscle, that is, the degeneration could be associated to increased tendon length and decreased belly from more primitive primates to those most derivate, that is, great apes to modern humans. In conclusion, in primates, the tendon of the palmaris longus increase from Lemuriformes to modern humans, that is, from arboreal to terrestrial primates and the muscle became weaker and tending to be missing.

  13. Muscle hypertrophy in quadriplegics with combined electrical stimulation and body weight support training.

    Science.gov (United States)

    Carvalho de Abreu, Daniela Cristina; Júnior, Alberto Cliquet; Rondina, Jane Maryan; Cendes, Fernando

    2008-06-01

    We describe the analysis of muscle hypertrophy in complete quadriplegics after 6 months of treadmill gait training with neuromuscular electrical stimulation (NMES). We aim to evaluate the effect of treadmill gait training using NMES, with 30-50% body weight relief, on muscle mass. Fifteen quadriplegics were divided into gait (n=8) and control (n=7) groups. The gait group (GG) performed training, associated to partial body weight support, for 6 months, twice a week, for 20 min. Control group (CG) individuals performed only conventional physiotherapy, but did not perform gait training using NMES. Magnetic resonance imaging (MRI) was performed over quadriceps, at the beginning and after 6 months. The MRI was done to determine the average of cross-sectional area of the quadriceps. Moreover, a gray scale was used to separate the muscle from the conjunctive tissue (when the value is closer to 225, there is a higher amount of muscle tissue). After 6 months there was an increase of cross-sectional area in the gait group (from 49.81+/-9.36 to 57.33+/-10.32 cm2; P=0.01), but not in the control group (from 43.60+/-7.56 to 41.65 +/- 9.44 cm2; P=0.17). The gray scale did not show significant differences after 6 months; however, the mean value of the gray scale inside the quadriceps in the gait group increased by 7.7% and in the control group decreased by 11.4%. Treadmill gait associated with NMES was efficient to promove quadriceps muscle hypertrophy in quadriplegics with chronic lesions even when a partial body weight support was provided.

  14. Microwave non-contact imaging of subcutaneous human body tissues

    Science.gov (United States)

    Chernokalov, Alexander; Khripkov, Alexander; Cho, Jaegeol; Druchinin, Sergey

    2015-01-01

    A small-size microwave sensor is developed for non-contact imaging of a human body structure in 2D, enabling fitness and health monitoring using mobile devices. A method for human body tissue structure imaging is developed and experimentally validated. Subcutaneous fat tissue reconstruction depth of up to 70 mm and maximum fat thickness measurement error below 2 mm are demonstrated by measurements with a human body phantom and human subjects. Electrically small antennas are developed for integration of the microwave sensor into a mobile device. Usability of the developed microwave sensor for fitness applications, healthcare, and body weight management is demonstrated. PMID:26609415

  15. Human body capacitance: static or dynamic concept? [ESD

    DEFF Research Database (Denmark)

    Jonassen, Niels M

    1998-01-01

    A standing human body insulated from ground by footwear and/or floor covering is in principle an insulated conductor and has, as such, a capacitance, i.e. the ability to store a charge and possibly discharge the stored energy in a spark discharge. In the human body, the human body capacitance (HBC...... when a substantial part of the flux extends itself through badly defined stray fields. Since the concept of human body capacitance is normally used in a static (electric) context, it is suggested that the HBC be determined by a static method. No theoretical explanation of the observed differences...

  16. Microwave non-contact imaging of subcutaneous human body tissues.

    Science.gov (United States)

    Kletsov, Andrey; Chernokalov, Alexander; Khripkov, Alexander; Cho, Jaegeol; Druchinin, Sergey

    2015-10-01

    A small-size microwave sensor is developed for non-contact imaging of a human body structure in 2D, enabling fitness and health monitoring using mobile devices. A method for human body tissue structure imaging is developed and experimentally validated. Subcutaneous fat tissue reconstruction depth of up to 70 mm and maximum fat thickness measurement error below 2 mm are demonstrated by measurements with a human body phantom and human subjects. Electrically small antennas are developed for integration of the microwave sensor into a mobile device. Usability of the developed microwave sensor for fitness applications, healthcare, and body weight management is demonstrated.

  17. Skeletal muscle fat metabolism after exercise in humans: influence of fat availability.

    Science.gov (United States)

    Kimber, Nicholas E; Cameron-Smith, David; McGee, Sean L; Hargreaves, Mark

    2013-06-01

    The mechanisms facilitating increased skeletal muscle fat oxidation following prolonged, strenuous exercise remain poorly defined. The aim of this study was to examine the influence of plasma free fatty acid (FFA) availability on intramuscular malonyl-CoA concentration and the regulation of whole-body fat metabolism during a 6-h postexercise recovery period. Eight endurance-trained men performed three trials, consisting of 1.5 h high-intensity and exhaustive exercise, followed by infusion of saline, saline + nicotinic acid (NA; low FFA), or Intralipid and heparin [high FFA (HFA)]. Muscle biopsies were obtained at the end of exercise (0 h) and at 3 and 6 h in recovery. Ingestion of NA suppressed the postexercise plasma FFA concentration throughout recovery (P increase in whole-body fat oxidation during the 6-h period for HFA (52.2 ± 4.8 g) relative to NA (38.4 ± 3.1 g; P muscle malonyl-CoA and acetyl-CoA carboxylase (ACC)β phosphorylation, suggesting mechanisms other than phosphorylation-mediated changes in ACC activity may have a role in regulating fat metabolism in human skeletal muscle during postexercise recovery. Despite marked changes in plasma FFA availability, no significant changes in intramuscular triglyceride concentrations were detected. These data suggest that the regulation of postexercise skeletal muscle fat oxidation in humans involves factors other than the 5'AMP-activated protein kinase-ACCβ-malonyl-CoA signaling pathway, although malonyl-CoA-mediated regulation cannot be excluded completely in the acute recovery period.

  18. Does quercetin and vitamin C improve exercise performance, muscle damage, and body composition in male athletes?

    Science.gov (United States)

    Askari, Gholamreza; Ghiasvand, Reza; Karimian, Jahangir; Feizi, Awat; Paknahad, Zamzam; Sharifirad, Gholamreza; Hajishafiei, Maryam

    2012-01-01

    Background: Quercetin is a bioflavonoid occurs in many food items. Some previous studies on quercetin showed the inconsistent results on exercise performance and muscle damage in athletes. The aim of this study was to determine the effects of 8 weeks of quercetin supplementation on exercise performance and muscle damage indices in student athletes. Methods: This placebo-controlled, double-blind clinical trial was conducted on 60 male students for 8 weeks. The subjects were randomly assigned to one of the four groups: a) quercetin (500 mg/day quercetin + 200 mg/day placebo), b) quercetin+ vitamin C (500 mg/day quercetin + 200 mg/day vitamin C), vitamin C (500 mg/day placebo + 200 mg/day vitamin C), and placebo (500 mg/day placebo + 200 mg/day placebo). Time to exhaustion (TTE) for measuring performance, aspartate transaminase (AST), and creatine kinase (CK) for measuring muscle damage and body fat percent (BFP) were measured before and after intervention. Results: CK levels reduced in group 1 significantly (P=0.045) and BFP reduced in group 1, 3, and 4, significantly, too (P=0.018, P=0.013, and P=0.043, respectively). Whereas statistically significant changes between groups were not observed for TTE, AST, CK, and BFP after 8 weeks of intervention. Conclusions: Supplementation with quercetin and vitamin C for 8 weeks did not improve exercise performance but reduced muscle damage and body fat percent in healthy subjects. PMID:23267392

  19. Does quercetin and vitamin C improve exercise performance, muscle damage, and body composition in male athletes?

    Directory of Open Access Journals (Sweden)

    Gholamreza Askari

    2012-01-01

    Full Text Available Background: quercetin is a bioflavonoid occurs in many food items. Some previous studies on quercetin showed the inconsistent results on exercise performance and muscle damage in athletes. The aim of this study was to determine the effects of 8 weeks of quercetin supplementation on exercise performance and muscle damage indices in student athletes. Methods: this placebo-controlled, double-blind clinical trial was conducted on 60 male students for 8 weeks. The subjects were randomly assigned to one of the four groups: a quercetin (500 mg/day quercetin + 200 mg/day placebo, b quercetin+ vitamin C (500 mg/day quercetin + 200 mg/day vitamin C, vitamin C (500 mg/day placebo + 200 mg/day vitamin C, and placebo (500 mg/day placebo + 200 mg/day placebo. Time to exhaustion (TTE for measuring performance, aspartate transaminase (AST, and creatine kinase (CK for measuring muscle damage and body fat percent (BFP were measured before and after intervention. Results: CK levels reduced in group 1 significantly (P=0.045 and BFP reduced in group 1, 3, and 4, significantly, too (P=0.018, P=0.013, and P=0.043, respectively. Whereas statistically significant changes between groups were not observed for TTE, AST, CK, and BFP after 8 weeks of intervention. Conclusions: supplementation with quercetin and vitamin C for 8 weeks did not improve exercise performance but reduced muscle damage and body fat percent in healthy subjects.

  20. Muscle Gene Expression Patterns in Human Rotator Cuff Pathology

    Science.gov (United States)

    Choo, Alexander; McCarthy, Meagan; Pichika, Rajeswari; Sato, Eugene J.; Lieber, Richard L.; Schenk, Simon; Lane, John G.; Ward, Samuel R.

    2014-01-01

    Background: Rotator cuff pathology is a common source of shoulder pain with variable etiology and pathoanatomical characteristics. Pathological processes of fatty infiltration, muscle atrophy, and fibrosis have all been invoked as causes for poor outcomes after rotator cuff tear repair. The aims of this study were to measure the expression of key genes associated with adipogenesis, myogenesis, and fibrosis in human rotator cuff muscle after injury and to compare the expression among groups of patients with varied severities of rotator cuff pathology. Methods: Biopsies of the supraspinatus muscle were obtained arthroscopically from twenty-seven patients in the following operative groups: bursitis (n = 10), tendinopathy (n = 7), full-thickness rotator cuff tear (n = 8), and massive rotator cuff tear (n = 2). Quantitative polymerase chain reaction (qPCR) was performed to characterize gene expression pathways involved in myogenesis, adipogenesis, and fibrosis. Results: Patients with a massive tear demonstrated downregulation of the fibrogenic, adipogenic, and myogenic genes, indicating that the muscle was not in a state of active change and may have difficulty responding to stimuli. Patients with a full-thickness tear showed upregulation of fibrotic and adipogenic genes; at the tissue level, these correspond to the pathologies most detrimental to outcomes of surgical repair. Patients with bursitis or tendinopathy still expressed myogenic genes, indicating that the muscle may be attempting to accommodate the mechanical deficiencies induced by the tendon tear. Conclusions: Gene expression in human rotator cuff muscles varied according to tendon injury severity. Patients with bursitis and tendinopathy appeared to be expressing pro-myogenic genes, whereas patients with a full-thickness tear were expressing genes associated with fatty atrophy and fibrosis. In contrast, patients with a massive tear appeared to have downregulation of all gene programs except inhibition of

  1. Reflex influences on muscle spindle activity in relaxed human leg muscles.

    Science.gov (United States)

    Gandevia, S C; Miller, S; Aniss, A M; Burke, D

    1986-07-01

    The study was designed to determine whether low-threshold cutaneous and muscle afferents from the foot reflexly activate gamma-motoneurons innervating relaxed muscles of the leg. In 15 experiments multiunit recordings were made from 21 nerve fascicles innervating triceps surae or tibialis anterior. In a further nine experiments the activity of 19 identified single muscle spindle afferents was recorded, 13 from triceps surae, 5 from tibialis anterior, and 1 from extensor digitorum longus. Trains of electrical stimuli (5 stimuli, 300 Hz) were delivered to the sural nerve at the ankle (intensity, twice sensory threshold) and the posterior tibial nerve at the ankle (intensity, 1.1 times motor threshold for the small muscles of the foot). In addition, a tap on the appropriate tendon at varying times after the stimuli was used to assess the dynamic responsiveness of the afferents under study. The conditioning electrical stimuli did not change the discharge of single spindle afferents. Recordings of rectified and averaged multiunit activity also revealed no change in the overall level of background neural activity following the electrical stimuli. The afferent responses to tendon taps did not differ significantly whether or not they were preceded by stimulation of the sural or posterior tibial nerves. These results suggest that low-threshold afferents from the foot do not produce significant activation of fusimotor neurons in relaxed leg muscles, at least as judged by their ability to alter the discharge of muscle spindle afferents. As there may be no effective background activity in fusimotor neurons innervating relaxed human muscles, it is possible that these inputs from the foot could influence the fusimotor system during voluntary contractions when the fusimotor neurons have been brought to firing threshold. In one subject trains of stimuli were delivered to the posterior tibial nerve at painful levels (30 times motor threshold). They produced an acceleration of the

  2. Lumbar back muscle activity of helicopter pilots and whole-body vibration.

    Science.gov (United States)

    de Oliveira, C G; Simpson, D M; Nadal, J

    2001-10-01

    Several studies have attributed the prevalence of low back pain (LBP) in helicopter pilots mainly to poor posture in-flight and whole-body vibration, with the latter hypothesis particularly related to a cyclic response of the erector spine (ES) muscle to vibration. This work aims to determine if helicopter vibration and the pilot's normal posture during flight have significant effects on the electromyogram (EMG) of the ES muscle. The bilateral surface EMG of the ES muscle at the L3 level was collected in 10 young pilots before and during a short flight in UH-50 helicopters. The vibration was monitored by a triaxial accelerometer fixed to the pilots' seat. Prior to the flight, the EMG was recorded for relaxed seated and standing postures with 0 degrees (P0) and 35 degrees (P35) of trunk flexion. The effect of the posture during the flight was tested by comparing left and right EMG (normalized with respect to P35). The in-flight muscle stress was evaluated by histograms of EMG activity, and compared to P0 values. Only one pilot in ten showed significant (pvibration and the EMG over cycles of vibration, and no consistent causal effect was found. The pilots' posture did not show significant asymmetric muscular activity, and low EMG levels were observed during most of the duration of the flight. The results do not provide evidence that LBP in helicopter pilots is caused by ES muscle stress in the conditions studied.

  3. Whole-body muscle MRI to detect myopathies in non-extrapyramidal bent spine syndrome

    Energy Technology Data Exchange (ETDEWEB)

    Ohana, Mickael [Nouvel Hopital Civil - Hopitaux Universitaires de Strasbourg, Service de Radiologie B, Strasbourg (France); Durand, Marie-Christine [AP-HP - Hopital Raymond Poincare, Service de Neurologie, Garches (France); Marty, Catherine; Lazareth, Jean-Philippe [AP-HP - Hopital Raymond Poincare, Service de Rhumatologie, Garches (France); Maisonobe, Thierry [APH-HP - Hopital de la Pitie-Salpetriere, Service de Neuropathologie, Paris (France); Mompoint, Dominique; Carlier, Robert-Yves [AP-HP - Hopital Raymond Poincare, Service de Radiologie, Garches (France)

    2014-08-15

    Bent spine syndrome (BSS), defined as an abnormal forward flexion of the trunk resolving in supine position, is usually related to parkinsonism, but can also be encountered in myopathies. This study evaluates whole-body muscle MRI (WB-mMRI) as a tool for detecting underlying myopathy in non-extrapyramidal BSS. Forty-three patients (90 % women; 53-86 years old) with a non-extrapyramidal BSS were prospectively included. All underwent a 1.5-T WB-mMRI and a nerve conduction study. Muscle biopsy was performed if a myopathy could not be eliminated based on clinical examination and all tests. Systematic MRI interpretation focused on peripheral and axial muscle injury; spinal posture and incidental findings were also reported. WB-mMRI was completed for all patients, with 13 muscle biopsies ultimately needed and myopathy revealed as the final etiological diagnosis in five cases (12 %). All biopsy-proven myopathies were detected by the WB-mMRI. Relevant incidental MRI findings were made in seven patients. This study supports WB-mMRI as a sensitive and feasible tool for detecting myopathy in BSS patients. Associated with electroneuromyography, it can better indicate when a muscle biopsy is needed and guide it when required. Rigorous radiological interpretation is mandatory, so as not to miss incidental findings of clinical consequence. (orig.)

  4. Recognition and treatment of muscle dysmorphia and related body image disorders.

    Science.gov (United States)

    Leone, James E; Sedory, Edward J; Gray, Kimberly A

    2005-01-01

    To present the reader with various psychobehavioral characteristics of muscle dysmorphia, discuss recognition of the disorder, and describe treatment and referral options. We conducted a comprehensive review of the relevant literature in CINAHL, MEDLINE, SPORT Discus, EBSCO, PsycINFO, and PubMed. All years from 1985 to the present were searched for the terms muscle dysmorphia, bigorexia, and reverse anorexia. The incidence of muscle dysmorphia is increasing, both in the United States and in other regions of the world, perhaps because awareness and recognition of the condition have increased. Although treatment options are limited, therapy and medication do work. The primary issue is identifying the disorder, because it does not present like other psychobehavioral conditions such as anorexia or bulimia nervosa. Not only do patients see themselves as healthy, most look very healthy from an outward perspective. The causes of muscle dysmorphia are not well understood, which reinforces the need for continued investigation. Muscle dysmorphia is an emerging phenomenon in society. Pressure on males to appear more muscular and lean has prompted a trend in the area of psychobehavioral disorders often likened to anorexia and bulimia nervosa. Athletes are particularly susceptible to developing body image disorders because of the pressures surrounding sport performance and societal trends promoting muscularity and leanness. Health care professionals need to become more familiar with the common signs and symptoms of muscle dysmorphia, as well as the treatment and referral options, in order to assist in providing appropriate care. In the future, authors should continue to properly measure and document the incidence of muscle dysmorphia in athletic populations, both during and after participation.

  5. Effect of muscle length on cross-bridge kinetics in intact cardiac trabeculae at body temperature

    Science.gov (United States)

    Milani-Nejad, Nima; Xu, Ying; Davis, Jonathan P.; Campbell, Kenneth S.

    2013-01-01

    Dynamic force generation in cardiac muscle, which determines cardiac pumping activity, depends on both the number of sarcomeric cross-bridges and on their cycling kinetics. The Frank–Starling mechanism dictates that cardiac force development increases with increasing cardiac muscle length (corresponding to increased ventricular volume). It is, however, unclear to what extent this increase in cardiac muscle length affects the rate of cross-bridge cycling. Previous studies using permeabilized cardiac preparations, sub-physiological temperatures, or both have obtained conflicting results. Here, we developed a protocol that allowed us to reliably and reproducibly measure the rate of tension redevelopment (ktr; which depends on the rate of cross-bridge cycling) in intact trabeculae at body temperature. Using K+ contractures to induce a tonic level of force, we showed the ktr was slower in rabbit muscle (which contains predominantly β myosin) than in rat muscle (which contains predominantly α myosin). Analyses of ktr in rat muscle at optimal length (Lopt) and 90% of optimal length (L90) revealed that ktr was significantly slower at Lopt (27.7 ± 3.3 and 27.8 ± 3.0 s−1 in duplicate analyses) than at L90 (45.1 ± 7.6 and 47.5 ± 9.2 s−1). We therefore show that ktr can be measured in intact rat and rabbit cardiac trabeculae, and that the ktr decreases when muscles are stretched to their optimal length under near-physiological conditions, indicating that the Frank–Starling mechanism not only increases force but also affects cross-bridge cycling kinetics. PMID:23277479

  6. [The gift of human body's products: philosophical and ethical aspects].

    Science.gov (United States)

    Baertschi, B

    2014-09-01

    In continental Europe, there is a very strong moral condemnation against putting parts or products of the human body on sale-and, consequently, against putting sperms and oocytes on sale. Only a gift is morally permissible. The situation is different in Anglo-Saxon countries. Who is right? Above all, it must be noticed that two views of the human body are facing each other here: for the first, the human body is a part of the person (so, it partakes of the person's dignity), whereas for the second, the human body is a possession of the person (the person is the owner of his/her body). In my opinion, the argument of dignity comes up against serious objections, and the property argument is more consistent. However, it does not follow that it would be judicious to put parts and products of the human body for sale on a market.

  7. Muscle development and body growth in larvae and early post-larvae of shi drum, Umbrina cirrosa L., reared under different larval photoperiod: muscle structural and ultrastructural study.

    Science.gov (United States)

    Ayala, Maria D; Abellán, Emilia; Arizcun, Marta; García-Alcázar, Alicia; Navarro, F; Blanco, Alfonso; López-Albors, Octavio M

    2013-08-01

    Shi drum specimens were maintained under four different photoperiod regimes: a natural photoperiod regime (16L:8D), constant light (24L), equal durations of light and dark (12L:12D) and a reduced number of daylight hours (6L:18D) from hatching until the end of larval metamorphosis. Specimens were then kept under natural photoperiod conditions until 111 days post-hatching. Muscle and body parameters were studied. During the vitelline phase, there was little muscle growth and no photoperiod effects were reported; however, a monolayer of red muscle and immature white muscle fibres were observed in the myotome. At hatching, external cells (presumptive myogenic cells) were already present on the surface of the red muscle. At the mouth opening, some presumptive myogenic cells appeared between the red and white muscles. At 20 days, new germinal areas were observed in the apical extremes of the myotome. At this stage, the 16L:8D group (followed by the 24L group) had the longest body length, the largest cross-sectional area of white muscle and the largest white muscle fibres. Conversely, white muscle hyperplasia was most pronounced in the 24L group. Metamorphosis was complete at 33 days in the 24L and 12L:12D groups. At this moment, both groups showed numerous myogenic precursors on the surface of the myotome as well as among the adult muscle fibres (mosaic hyperplastic growth). The 16L:8D group completed metamorphosis at 50 days, showing a similar degree of structural maturity in the myotome to that described in the 24L and 12L:12D groups at 33 days. When comparing muscle growth at the end of the larval period, hypertrophy was highest in the 16L:8D group, whereas hyperplasia was higher in the 24L and 16L:8D groups. At 111 days, all groups showed the adult muscle pattern typical of teleosts; however, the cross-sectional area of white muscle, white muscle fibre hyperplasia, body length and body weight were highest in the 24L group, followed by the 12L:12D group; white muscle

  8. [Neural representation of human body schema and corporeal self-consciousness].

    Science.gov (United States)

    Naito, Eiichi; Morita, Tomoyo

    2014-04-01

    The human brain processes every sensation evoked by altered posture and builds up a constantly changing postural model of the body. This is called a body schema, and somatic signals originating from skeletal muscles and joints, i.e. proprioceptive signals, largely contribute its formation. Recent neuroimaging techniques have revealed neuronal substrates for human body schema. A dynamic limb position model seems to be computed in the central motor network (represented by the primary motor cortex). Here, proprioceptive (kinesthetic) signals from muscle spindles are transformed into motor commands, which may underlie somatic perception of limb movement and facilitate its efficient motor control. Somatic signals originating from different body parts are integrated in the course of hierarchical somatosensory processing, and activity in higher-order somatosensory parietal cortices is capable of representing a postural model of the entire body. The left fronto-parietal network associates internal motor representation with external object representation, allowing the embodiment of external objects. In contrast, the right fronto-parietal regions connected by the most inferior branch of superior longitudinal fasciculus fibers seem to have the functions of monitoring bodily states and updating body schema. We hypothesize that activity in these right-sided fronto-parietal regions is deeply involved in corporeal self-consciousness.

  9. Selective activation of neuromuscular compartments within the human trapezius muscle

    DEFF Research Database (Denmark)

    Holtermann, A; Roeleveld, K; Mork, P J

    2009-01-01

    was to investigate whether subdivisions within the human trapezius can be independently activated by voluntary command using biofeedback guidance. Bipolar electromyographical electrodes were situated on four subdivisions of the trapezius muscle. The threshold for "active" and "rest" for each subdivision was set...... to >12% and biofeedback from each of the four trapezius subdivisions, 11 of 15 subjects learned selective activation of at least one of the four anatomical subdivisions of the trapezius...

  10. Expression of human IAP-like protein in skeletal muscle: a possible explanation for the rare incidence of muscle fiber apoptosis in T-cell mediated inflammatory myopathies.

    Science.gov (United States)

    Li, M; Dalakas, M C

    2000-07-01

    In Polymyositis (PM) and sporadic Inclusion Body Myositis (s-IBM), the CD8(+) cytotoxic T cells invade the muscle membrane and release perforin and granzyme B to induce cell death. Although granzyme B is a direct activator of executioner caspases, there is no convincing evidence of apoptosis in the muscle fibers of these patients. To search for an explanation, we examined the muscle expression of the human IAP-Like Protein (hILP), an evolutionarily conserved cell death suppressor, that exerts major anti-apoptotic effects by inhibiting the executioner caspases. Muscle biopsy specimens from patients with inflammatory myopathies and controls were studied with: (a) immunocytochemistry using antibodies against hILP and caspase-3 in single and double-labeled confocal laser microscopy; (b) immunoblotting of muscle extracts immunoreacted with anti-hILP antibodies; and (c) subcellular fractionation of muscle lysates immunoreacted with antibodies against hILP. We found that hILP is expressed on the sarcolemmal region and co-localizes with dystrophin. Caspase-3 is undetectable. Subcellular fractionation of the muscle specimens confirmed that hILP is a membrane-associated protein. By immunoblotting, the 57 kD hILP was abundantly expressed in the normal as well as the diseased muscles. We conclude that in s-IBM and PM the expression of hILP, a major cell death suppressor, on the muscle membrane may prevent the induction of apoptosis by the autoinvasive cytotoxic T cells on the cell surface, by inhibiting the caspase activation.

  11. [Investigations of human body liquids in long-duration space flight].

    Science.gov (United States)

    Noskov, V B; Nichiporuk, I A; Morukov, B V; Malenchenko, Iu I

    2005-01-01

    The hydration status of a Russian member on a six-month ISS mission was evaluated by bio-impedancemetry during monthly sessions of experiment Sprut (Octopus). Body liquids tended to diminish gradually and measured minimum values on the landing day. By the end of mission the total volume of liquids reduced by 18.9 %; the intracellular and extracellular portions lost 19.0 and 20.4 %, respectively. Time history of specific body liquids was identical in flight. Reductions in the body mass and lean mass (according to impedancemetry) reached 6.9 % and 8.0 %, respectively. These results point to a decrease in the human body hydration status during long-duration space flight concurrent to losses in the muscle mass. In two weeks after landing there was an implicit trend toward regaining the pre-flight hydration status and body mass; yet, both parameters were still below pre-flight values.

  12. Influence of exercise contraction mode and protein supplementation on human skeletal muscle satellite cell content and muscle fiber growth.

    Science.gov (United States)

    Farup, Jean; Rahbek, Stine Klejs; Riis, Simon; Vendelbo, Mikkel Holm; Paoli, Frank de; Vissing, Kristian

    2014-10-15

    Skeletal muscle satellite cells (SCs) are involved in remodeling and hypertrophy processes of skeletal muscle. However, little knowledge exists on extrinsic factors that influence the content of SCs in skeletal muscle. In a comparative human study, we investigated the muscle fiber type-specific association between emergence of satellite cells (SCs), muscle growth, and remodeling in response to 12 wk unilateral resistance training performed as eccentric (Ecc) or concentric (Conc) resistance training ± whey protein (Whey, 19.5 g protein + 19.5 g glucose) or placebo (Placebo, 39 g glucose) supplementation. Muscle biopsies (vastus lateralis) were analyzed for fiber type-specific SCs, myonuclei, and fiber cross-sectional area (CSA). Following training, SCs increased with Conc in both type I and type II fibers (P hypertrophy correlated with whole muscle hypertrophy exclusively following Conc training (P eccentric resistance training while type II fiber hypertrophy was accentuated when combining concentric resistance training with whey protein supplementation.

  13. Physiological models of body composition and human obesity

    Directory of Open Access Journals (Sweden)

    Shapses Sue A

    2007-09-01

    Full Text Available Abstract Background The body mass index (BMI is the standard parameter for predicting body fat fraction and for classifying degrees of obesity. Currently available regression equations between BMI and fat are based on 2 or 3 parameter empirical fits and have not been validated for highly obese subjects. We attempt to develop regression relations that are based on realistic models of body composition changes in obesity. These models, if valid, can then be extrapolated to the high fat fraction of the morbidly obese. Methods The analysis was applied to 3 compartment (density and total body water measurements of body fat. The data was collected at the New York Obesity Research Center, Body Composition Unit, as part of ongoing studies. A total of 1356 subjects were included, with a BMI range of 17 to 50 for males and 17 to 65 for females. The body composition model assumes that obese subjects can be represented by the sum of a standard lean reference subject plus an extra weight that has a constant adipose, bone and muscle fraction. Results There is marked age and sex dependence in the relationship between BMI and fat fraction. There was no significant difference among Caucasians, Blacks and Hispanics while Asians had significantly greater fat fraction for the same BMI. A linear relationship between BMI and fat fraction provides a good description for men but overestimates the fat fraction in morbidly obese women for whom a non-linear regression should be used. New regression relations for predicting body fat just from experimental measurements of body density are described that are more accurate then those currently used. From the fits to the experimental BMI and density data, a quantitative description of the bone, adipose and muscle body composition of lean and obese subjects is derived. Conclusion Physiologically realistic models of body composition provide both accurate regression relations and new insights about changes in body composition in

  14. Increased muscle fatty acid oxidation in dairy cows with intensive body fat mobilization during early lactation.

    Science.gov (United States)

    Schäff, C; Börner, S; Hacke, S; Kautzsch, U; Sauerwein, H; Spachmann, S K; Schweigel-Röntgen, M; Hammon, H M; Kuhla, B

    2013-10-01

    The beginning of lactation requires huge metabolic adaptations to meet increased energy demands for milk production of dairy cows. One of the adaptations is the mobilization of body reserves mainly from adipose tissue as reflected by increased plasma nonesterified fatty acid (NEFA) concentrations. The capacity of the liver for complete oxidation of NEFA is limited, leading to an increased formation of ketone bodies, reesterification, and accumulation of triglycerides in the liver. As the skeletal muscle also may oxidize fatty acids, it may help to decrease the fatty acid load on the liver. To test this hypothesis, 19 German Holstein cows were weekly blood sampled from 7 wk before until 5 wk after parturition to analyze plasma NEFA concentrations. Liver biopsies were obtained at d 3, 18, and 30 after parturition and, based on the mean liver fat content, cows were grouped to the 10 highest (HI) and 9 lowest (LO). In addition, muscle biopsies were obtained at d -17, 3, and 30 relative to parturition and used to quantify mRNA abundance of genes involved in fatty acid degradation. Plasma NEFA concentrations peaked after parturition and were 1.5-fold higher in HI than LO cows. Muscle carnitine palmitoyltransferase 1α and β mRNA was upregulated in early lactation. The mRNA abundance of muscle peroxisome proliferator-activated receptor γ (PPARG) increased in early lactation and was higher in HI than in LO cows, whereas the abundance of PPARA continuously decreased after parturition. The mRNA abundance of muscle PPARD, uncoupling protein 3, and the β-oxidative enzymes 3-hydroxyacyl-coenzyme A (CoA) dehydrogenase, very long-chain acyl-CoA dehydrogenase, and 3-ketoacyl-CoA was greatest at d 3 after parturition, whereas the abundance of PPARγ coactivator 1α decreased after parturition. Our results indicate that around parturition, oxidation of fatty acids in skeletal muscle is highly activated, which may contribute to diminish the fatty acid load on the liver. The

  15. Cancer cachexia in the age of obesity: skeletal muscle depletion is a powerful prognostic factor, independent of body mass index.

    Science.gov (United States)

    Martin, Lisa; Birdsell, Laura; Macdonald, Neil; Reiman, Tony; Clandinin, M Thomas; McCargar, Linda J; Murphy, Rachel; Ghosh, Sunita; Sawyer, Michael B; Baracos, Vickie E

    2013-04-20

    Emerging evidence suggests muscle depletion predicts survival of patients with cancer. At a cancer center in Alberta, Canada, consecutive patients with cancer (lung or GI; N = 1,473) were assessed at presentation for weight loss history, lumbar skeletal muscle index, and mean muscle attenuation (Hounsfield units) by computed tomography (CT). Univariate and multivariate analyses were conducted. Concordance (c) statistics were used to test predictive accuracy of survival models. Body mass index (BMI) distribution was 17% obese, 35% overweight, 36% normal weight, and 12% underweight. Patients in all BMI categories varied widely in weight loss, muscle index, and muscle attenuation. Thresholds defining associations between these three variables and survival were determined using optimal stratification. High weight loss, low muscle index, and low muscle attenuation were independently prognostic of survival. A survival model containing conventional covariates (cancer diagnosis, stage, age, performance status) gave a c statistic of 0.73 (95% CI, 0.67 to 0.79), whereas a model ignoring conventional variables and including only BMI, weight loss, muscle index, and muscle attenuation gave a c statistic of 0.92 (95% CI, 0.88 to 0.95; P obese, overweight, normal weight, or underweight, in contrast to patients who had none of these features, who survived 28.4 months (95% CI, 24.2 to 32.6; P cancer who are cachexic by the conventional criterion (involuntary weight loss) and by two additional criteria (muscle depletion and low muscle attenuation) share a poor prognosis, regardless of overall body weight.

  16. Human body and head characteristics as a communication medium for Body Area Network.

    Science.gov (United States)

    Kifle, Yonatan; Hun-Seok Kim; Yoo, Jerald

    2015-01-01

    An in-depth investigation of the Body Channel Communication (BCC) under the environment set according to the IEEE 802.15.6 Body Area Network (BAN) standard is conducted to observe and characterize the human body as a communication medium. A thorough measurement of the human head as part of the human channel is also carried out. Human forehead, head to limb, and ear to ear channel is characterized. The channel gain of the human head follows the same bandpass profile of the human torso and limbs with the maximum channel gain occurring at 35MHz. The human body channel gain distribution histogram at given frequencies, while all the other parameters are held constant, exhibits a maximum variation of 2.2dB in the channel gain at the center frequency of the bandpass channel gain profile.

  17. Noninvasive assessment of sympathetic vasoconstriction in human and rodent skeletal muscle using near-infrared spectroscopy and Doppler ultrasound.

    Science.gov (United States)

    Fadel, Paul J; Keller, David M; Watanabe, Hitoshi; Raven, Peter B; Thomas, Gail D

    2004-04-01

    The precise role of the sympathetic nervous system in the regulation of skeletal muscle blood flow during exercise has been challenging to define in humans, partly because of the limited techniques available for measuring blood flow in active muscle. Recent studies using near-infrared (NIR) spectroscopy to measure changes in tissue oxygenation have provided an alternative method to evaluate vasomotor responses in exercising muscle, but this approach has not been fully validated. In this study, we tested the hypothesis that sympathetic activation would evoke parallel changes in tissue oxygenation and blood flow in resting and exercising muscle. We simultaneously measured tissue oxygenation with NIR spectroscopy and blood flow with Doppler ultrasound in skeletal muscle of conscious humans (n = 13) and anesthetized rats (n = 9). In resting forearm of humans, reflex activation of sympathetic nerves with the use of lower body negative pressure produced graded decreases in tissue oxygenation and blood flow that were highly correlated (r = 0.80, P blood flow velocity that were highly correlated (r = 0.93, P blood flow evoked by sympathetic activation were significantly attenuated (P < 0.05 vs. rest) but remained highly correlated in both humans (r = 0.80, P < 0.006) and rats (r = 0.92, P < 0.0001). These data indicate that, during steady-state metabolic conditions, changes in tissue oxygenation can be used to reliably assess sympathetic vasoconstriction in both resting and exercising skeletal muscle.

  18. Specialised structural descriptions for human body parts: Evidence from autotopagnosia.

    Science.gov (United States)

    Buxbaum, L J; Coslett, H B

    2001-06-01

    Previous accounts of autotopagnosia (e.g., Ogden, 1985; Pick, 1908; Semenza, 1988) propose that the disorder is attributable to deficits in "mental images," visual body schema, or semantic representations. A recent account (Sirigu, Grafman, Bressler, & Sunderland, 1991b) posits deficits in visual structural descriptions of the human body and its parts, in the context of spared semantic and proprioceptivespatio-motor body representations, but provides no evidence bearing on the nature or format of the putatively damaged representation. We report data from a man with autotopagnosia consequent to lefthemisphere brain damage which bear directly on the nature of the representation impaired in the disorder. The subject, GL, is unable to localise body parts on himself or others, whether cued by verbal or visual input. In contrast, he uses body parts precisely in reaching and grasping tasks, correctly matches items of clothing to body parts, and localises the parts of animals and man-made objects without error. We also demonstrate that GL is unable to match pictured or real human body parts across shifts in orientation or changes in visual appearance, but can perform analogous matching tasks with animal body parts and man-made object parts. The data extend the account of Sirigu et al. (1991b) in suggesting that human body part localisation depends upon structural descriptions of human (but not animal) bodies that enable viewpoint-independent body part recognition and participate in the calculation of equivalence between the body parts of self and others across transformations in orientation.

  19. Development of Preferences for the Human Body Shape in Infancy.

    Science.gov (United States)

    Slaughter, Virginia; Heron, Michelle; Sim, Susan

    2002-01-01

    Two studies investigated development of infants' visual preferences for the human body shape. Results indicated that 18-month-olds had a reliable preference for scrambled body shapes over typical body shapes in line drawings, while 12- and 15-month-olds did not respond differentially. In condition using photographs, only 18-month-olds had reliable…

  20. Water and electrolytes. [in human bodies

    Science.gov (United States)

    Greenleaf, J. E.; Harrison, M. H.

    1986-01-01

    It has been found that the performance of the strongest and fittest people will deteriorate rapidly with dehydration. The present paper is concerned with the anatomy of the fluid spaces in the body, taking into account also the fluid shifts and losses during exercise and their effects on performance. Total body water is arbitrarily divided into that contained within cells (cellular) and that located outside the cells (extracellular). The anatomy of body fluid compartments is considered along with the effects of exercise on body water, fluid shifts with exercise, the consequences of sweating, dehydration and exercise, heat acclimatization and endurance training, the adverse effects of dehydration, thirst and drinking during exercise, stimuli for drinking, and water, electrolyte, and carbohydrate replacement during exercise. It is found that the deterioration of physical exercise performance due to dehydration begins when body weight decreases by about 1 percent.

  1. Whole-Body Vibration While Squatting and Delayed-Onset Muscle Soreness in Women.

    Science.gov (United States)

    Dabbs, Nicole C; Black, Christopher D; Garner, John

    2015-12-01

    Research into alleviating muscle pain and symptoms in individuals after delayed-onset muscle soreness (DOMS) has been inconsistent and unsuccessful in demonstrating a useful recovery modality. To investigate the effects of short-term whole-body vibration (WBV) on DOMS over a 72-hour period after a high-intensity exercise protocol. Randomized controlled clinical trial. University laboratory. Thirty women volunteered to participate in 4 testing sessions and were assigned randomly to a WBV group (n = 16; age = 21.0 ± 1.9 years, height = 164.86 ± 6.73 cm, mass = 58.58 ± 9.32 kg) or a control group (n = 14; age = 22.00 ± 1.97 years, height = 166.65 ± 8.04 cm, mass = 58.69 ± 12.92 kg). Participants performed 4 sets to failure of single-legged split squats with 40% of their body weight to induce muscle soreness in the quadriceps. The WBV or control treatment was administered each day after DOMS. Unilateral pressure-pain threshold (PPT), range of motion (ROM), thigh circumference, and muscle-pain ratings of the quadriceps were collected before and for 3 days after high-intensity exercise. Each day, we collected 3 sets of measures, consisting of 1 measure before the WBV or control treatment protocol (pretreatment) and 2 sets of posttreatment measures. We observed no interactions for PPT, thigh circumference, and muscle pain (P > .05). An interaction was found for active ROM (P = .01), with the baseline pretreatment measure greater than the measures at baseline posttreatment 1 through 48 hours posttreatment 2 in the WBV group. For PPT, a main effect for time was revealed (P .05). The WBV treatment approach studied did not aid in alleviating DOMS after high-intensity exercise. Further research is needed in various populations.

  2. Bionic Humans Using EAP as Artificial Muscles Reality and Challenges

    Directory of Open Access Journals (Sweden)

    Yoseph Bar-Cohen

    2008-11-01

    Full Text Available For many years, the idea of a human with bionic muscles immediately conjures up science fiction images of a TV series superhuman character that was implanted with bionic muscles and portrayed with strength and speed far superior to any normal human. As fantastic as this idea may seem, recent developments in electroactive polymers (EAP may one day make such bionics possible. Polymers that exhibit large displacement in response to stimulation that is other than electrical signal were known for many years. Initially, EAP received relatively little attention due to their limited actuation capability. However, in the recent years, the view of the EAP materials has changed due to the introduction of effective new materials that significantly surpassed the capability of the widely used piezoelectric polymer, PVDF. As this technology continues to evolve, novel mechanisms that are biologically inspired are expected to emerge. EAP materials can potentially provide actuation with lifelike response and more flexible configurations. While further improvements in performance and robustness are still needed, there already have been several reported successes. In recognition of the need for cooperation in this multidisciplinary field, the author initiated and organized a series of international forums that are leading to a growing number of research and development projects and to great advances in the field. In 1999, he challenged the worldwide science and engineering community of EAP experts to develop a robotic arm that is actuated by artificial muscles to win a wrestling match against a human opponent. In this paper, the field of EAP as artificial muscles will be reviewed covering the state of the art, the challenges and the vision for the progress in future years.

  3. Human Body Orientation Estimation using a Committee based Approach

    NARCIS (Netherlands)

    Ichim, M; Tan, R.T.; van der Aa, N.P.; Veltkamp, R.C.

    2014-01-01

    Human body orientation estimation is useful for analyzing the activities of a single person or a group of people. Estimating body orientation can be subdivided in two tasks: human tracking and orientation estimation. In this paper, the second task of orientation estimation is accomplished by using H

  4. High School Students' Understanding of the Human Body System

    Science.gov (United States)

    Assaraf, Orit Ben-Zvi; Dodick, Jeff; Tripto, Jaklin

    2013-01-01

    In this study, 120 tenth-grade students from 8 schools were examined to determine the extent of their ability to perceive the human body as a system after completing the first stage in their biology curriculum--"The human body, emphasizing homeostasis". The students' systems thinking was analyzed according to the STH thinking model, which roughly…

  5. Human body composition models and methodology : theory and experiment

    NARCIS (Netherlands)

    Wang, Z.M.

    1997-01-01


    The study of human body composition is a branch of human biology which focuses on the in vivo quantification of body components, the quantitative relationships between components, and the quantitative changes in these components related to various influencing factors.

  6. Reduced Appendicular Lean Body Mass, Muscle Strength, and Size of Type II Muscle Fibers in Patients with Spondyloarthritis versus Healthy Controls: A Cross-Sectional Study

    Directory of Open Access Journals (Sweden)

    Kristine Røren Nordén

    2016-01-01

    Full Text Available Introduction. The purpose of this study was to investigate body composition, muscle function, and muscle morphology in patients with spondyloarthritis (SpA. Methods. Ten male SpA patients (mean ± SD age 39±4.1 years were compared with ten healthy controls matched for sex, age, body mass index, and self-reported level of physical exercise. Body composition was measured by dual energy X-ray absorptiometry. Musculus quadriceps femoris (QF strength was assessed by maximal isometric contractions prior to test of muscular endurance. Magnetic resonance imaging of QF was used to measure muscle size and calculate specific muscle strength. Percutaneous needle biopsy samples were taken from m. vastus lateralis. Results. SpA patients presented with significantly lower appendicular lean body mass (LBM (p=0.02, but there was no difference in bone mineral density, fat mass, or total LBM. Absolute QF strength was significantly lower in SpA patients (p=0.03 with a parallel trend for specific strength (p=0.08. Biopsy samples from the SpA patients revealed significantly smaller cross-sectional area (CSA of type II muscle fibers (p=0.04, but no difference in CSA type I fibers. Conclusions. Results indicate that the presence of SpA disease is associated with reduced appendicular LBM, muscle strength, and type II fiber CSA.

  7. Localization and function of ATP-sensitive potassium channels in human skeletal muscle

    DEFF Research Database (Denmark)

    Nielsen, Jens Jung; Kristensen, Michael; Hellsten, Ylva

    2003-01-01

    The present study investigated the localization of ATP-sensitive K+ (KATP) channels in human skeletal muscle and the functional importance of these channels for human muscle K+ distribution at rest and during muscle activity. Membrane fractionation based on the giant vesicle technique...

  8. Pronounced effects of accute endurance exercise on gene expression in resting and exercising human skeletal muscle

    NARCIS (Netherlands)

    Catoire, M.; Mensink, M.R.; Boekschoten, M.V.; Hangelbroek, R.W.J.; Muller, M.R.; Schrauwen, P.; Kersten, A.H.

    2012-01-01

    Regular physical activity positively influences whole body energy metabolism and substrate handling in exercising muscle. While it is recognized that the effects of exercise extend beyond exercising muscle, it is unclear to what extent exercise impacts non-exercising muscles. Here we investigated th

  9. Muscle spindle composition and distribution in human young masseter and biceps brachii muscles reveal early growth and maturation.

    Science.gov (United States)

    Osterlund, Catharina; Liu, Jing-Xia; Thornell, Lars-Eric; Eriksson, Per-Olof

    2011-04-01

    Significant changes in extrafusal fiber type composition take place in the human masseter muscle from young age, 3-7 years, to adulthood, in parallel with jaw-face skeleton growth, changes of dentitions and improvement of jaw functions. As motor and sensory control systems of muscles are interlinked, also the intrafusal fiber population, that is, muscle spindles, should undergo age-related changes in fiber type appearance. To test this hypothesis, we examined muscle spindles in the young masseter muscle and compared the result with previous data on adult masseter spindles. Also muscle spindles in the young biceps brachii muscle were examined. The result showed that muscle spindle composition and distribution were alike in young and adult masseter. As for the adult masseter, young masseter contained exceptionally large muscle spindles, and with the highest spindle density and most complex spindles found in the deep masseter portion. Hence, contrary to our hypothesis, masseter spindles do not undergo major morphological changes between young age and adulthood. Also in the biceps, young spindles were alike adult spindles. Taken together, the results showed that human masseter and biceps muscle spindles are morphologically mature already at young age. We conclude that muscle spindles in the human young masseter and biceps precede the extrafusal fiber population in growth and maturation. This in turn suggests early reflex control and proprioceptive demands in learning and maturation of jaw motor skills. Similarly, well-developed muscle spindles in young biceps reflect early need of reflex control in learning and performing arm motor behavior. Copyright © 2011 Wiley-Liss, Inc.

  10. [BODY AND CORPORALITY IN THE HUMAN BEING: SOME INTERDISCIPLINARY REFLECTIONS].

    Science.gov (United States)

    Giménez Amaya, JosÉ Manuel

    2014-01-01

    The major purpose of this contribution is to illustrate some differential aspects between the human and the animal bodies, in order to understand the main distinctive characteristic of the human being: his or her rationality. Thus, we firstly deal with some considerations about the general anthropological framework in which the human body is going to be analysed. Next, we briefly explain the importance of the body for an adequate understanding of the intimacy and the biographical perspectives of the person. Here we show some examples of the altered human corporality to stress the importance of the relation to oneself and others as a key and fundamental aspect to look at our rational corporality.

  11. Adenosine concentrations in the interstitium of resting and contracting human skeletal muscle

    DEFF Research Database (Denmark)

    Hellsten, Ylva; Maclean, D.; Rådegran, G.

    1998-01-01

    effect remain unanswered. METHODS AND RESULTS: The interstitial adenosine concentration was determined in the vastus lateralis muscle of healthy humans via dialysis probes inserted in the muscle. The probes were perfused with buffer, and the dialysate samples were collected at rest and during graded knee...... and demonstrates that adenosine and its precursors increase in the exercising muscle interstitium, at a rate associated with intensity of muscle contraction and the magnitude of muscle blood flow....

  12. Ultrastructure of striated muscle fibers in the middle third of the human esophagus

    OpenAIRE

    Faussone-Pellegrini, M.S; Cortesini, C.

    1986-01-01

    Striated muscle fibers and .their spatial relationship to smooth muscle cells have been studied in the middle third of human esophagus. Biopsies were obtained from 3 patients during surgery. In both the circular and longitudinal layers, the muscle coat of this transition zone was composed of fascicles of uniform dimensioi~ (100-200 pm of diameter); some of these bundles were made up of striated muscle fibers, others were pure bundles of smooth muscle cells and ...

  13. Human skeletal muscle fibre types and force: velocity properties.

    Science.gov (United States)

    MacIntosh, B R; Herzog, W; Suter, E; Wiley, J P; Sokolosky, J

    1993-01-01

    It has been reported that there is a relationship between power output and fibre type distribution in mixed muscle. The strength of this relationship is greater in the range of 3-8 rad.s-1 during knee extension compared to slower or faster angular knee extensor speeds. A mathematical model of the force: velocity properties of muscle with various combinations of fast- and slow-twitch fibres may provide insight into why specific velocities may give better predictions of fibre type distribution. In this paper, a mathematical model of the force:velocity relationship for mixed muscle is presented. This model demonstrates that peak power and optimal velocity should be predictive of fibre distribution and that the greatest fibre type discrimination in human knee extensor muscles should occur with measurement of power output at an angular velocity just greater than 7 rad.s-1. Measurements of torque:angular velocity relationships for knee extension on an isokinetic dynamometer and fibre type distribution in biopsies of vastus lateralis muscles were made on 31 subjects. Peak power and optimal velocity were determined in three ways: (1) direct measurement, (2) linear regression, and (3) fitting to the Hill equation. Estimation of peak power and optimal velocity using the Hill equation gave the best correlation with fibre type distribution (r < 0.5 for peak power or optimal velocity and percentage of fast-twitch fibres). The results of this study confirm that prediction of fibre type distribution is facilitated by measurement of peak power at optimal velocity and that fitting of the data to the Hill equation is a suitable method for evaluation of these parameters.

  14. Effects of a single bout of lower-body aerobic exercise on muscle activation and performance during subsequent lower- and upper-body resistance exercise workouts.

    Science.gov (United States)

    Tan, Jeremy G; Coburn, Jared W; Brown, Lee E; Judelson, Daniel A

    2014-05-01

    A single bout of lower-body aerobic exercise may negatively affect a subsequent lower-body resistance exercise workout. However, less is known regarding the effects of a lower-body aerobic workout on muscle activation and performance during a subsequent upper-body resistance exercise workout. Therefore, the purpose of this study was to compare muscle activation and performance during lower- and upper-body resistance exercise workouts after a single bout of lower-body aerobic exercise on an elliptical machine. Fourteen men (mean age = 24.1 ± 2.3 years, height = 180.8 ± 6.9 cm, body mass = 91.9 ± 16.4 kg) completed 4 trials in random order. Two trials consisted of 30 minutes on the elliptical machine, using the lower body only, at 70% of age-predicted maximum heart rate before either a back squat or bench press workout, consisting of 3 sets to failure performed at 75% 1 repetition maximum. The other 2 trials consisted of only the back squat or bench press resistance workouts. To quantify muscle activation, bipolar surface electromyography electrodes were placed on the rectus femoris and vastus lateralis or pectoralis major. Acute lower-body aerobic exercise on an elliptical machine significantly reduced the number of repetitions completed for the back squat but not the bench press exercise. There was no significant difference in muscle activation between the elliptical and no elliptical conditions. However, for both exercises and conditions, muscle activation increased significantly between the first and final repetitions for the first 2 sets but not for the third set. These results suggest that to optimize the quality of a lower-body resistance-training workout, the workout should not be preceded by lower-body aerobic exercise.

  15. Whole body muscle activity during the FIFA 11+ program evaluated by positron emission tomography.

    Directory of Open Access Journals (Sweden)

    Junsuke Nakase

    Full Text Available PURPOSE: This study investigated the effect of the FIFA 11+ warm-up program on whole body muscle activity using positron emission tomography. METHODS: Ten healthy male volunteers were divided into a control group and a group that performed injury prevention exercises (The 11+. The subjects of the control group were placed in a sitting position for 20 min and 37 MBq of (18F-fluorodeoxyglucose (FDG was injected intravenously. The subjects then remained seated for 45 min. The subjects of the exercise group performed part 2 of the 11+for 20 min, after which FDG was injected. They then performed part 2 of the 11+for 20 min, and rested for 25 min in a sitting position. Positron emission tomography-computed tomography images were obtained 50 min after FDG injection in each group. Regions of interest were defined within 30 muscles. The standardized uptake value was calculated to examine the FDG uptake of muscle tissue per unit volume. RESULTS: FDG accumulation within the abdominal rectus, gluteus medius and minimus were significantly higher in the exercise group than in the control group (P<0.05. CONCLUSION: The hip abductor muscles and abdominal rectus were active during part 2 of the FIFA 11+ program.

  16. Is spinal excitability of the triceps surae mainly affected by muscle activity or body position?

    Science.gov (United States)

    Cattagni, T; Martin, A; Scaglioni, G

    2014-06-15

    The aim of this study was to determine how muscle activity and body orientation contribute to the triceps surae spinal transmission modulation, when moving from a sitting to a standing position. Maximal Hoffmann-reflex (Hmax) and motor potential (Mmax) were evoked in the soleus (SOL), medial and lateral gastrocnemius in 10 male subjects and in three conditions, passive sitting, active sitting and upright standing, with the same SOL activity in active sitting and upright standing. Moreover volitional wave (V) was evoked in the two active conditions (i.e., active sitting and upright standing). The results showed that SOL Hmax/Mmax was lower in active sitting than in passive sitting, while for the gastrocnemii it was not significantly altered. For the three plantar flexors, Hmax/Mmax was lower in upright standing than in active sitting, whereas V/Mmax was not modulated. SOL H-reflex is therefore affected by the increase in muscle activity and change in body orientation, while, in the gastrocnemii, it was only affected by a change in posture. In conclusion, passing from a sitting to a standing position affects the Hmax/Mmax of the whole triceps surae, but the mechanisms responsible for this change differ among the synergist muscles. The V/Mmax does not change when upright stance is assumed. This means that the increased inhibitory activity in orthostatic position is compensated by an increased excitatory inflow to the α-motoneurons of central and/or peripheral origin.

  17. Regulation of the skeletal muscle blood flow in humans

    DEFF Research Database (Denmark)

    Mortensen, Stefan; Saltin, Bengt

    2014-01-01

    In humans, skeletal muscle blood flow is regulated by an interaction between several locally formed vasodilators including nitric oxide (NO) and prostaglandins. In plasma, ATP is a potent vasodilator that stimulates the formation of NO and prostaglandins and very importantly can offset local...... sympathetic vasoconstriction. ATP is released into plasma from erythrocytes and endothelial cells and the plasma concentration increases in both the feeding artery and the vein draining the contracting skeletal muscle. Adenosine also stimulates the formation of NO and prostaglandins, but the plasma adenosine...... and endothelial cells. In the interstitium, both ATP and adenosine stimulate the formation of NO and prostaglandins, but ATP has also been suggested to induce vasoconstriction and stimulate afferent nerves that signal to increase sympathetic nerve activity. Adenosine has been shown to contribute to exercise...

  18. Muscle Disorders

    Science.gov (United States)

    Your muscles help you move and help your body work. Different types of muscles have different jobs. There are many problems that can affect muscles. Muscle disorders can cause weakness, pain or even ...

  19. Characteristics of Body Composition and Muscle Strength of North Korean Refugees during South Korean Stay

    Directory of Open Access Journals (Sweden)

    Sun Wook Cho

    2015-12-01

    Full Text Available BackgroundThe aim of this study was to investigate the changes of body composition and muscle strength of North Korean refugees (NKRs according to their duration of stay in South Korea.MethodsNKRs who volunteered and were living in South Korea, aged 20 to 75 years were recruited. Body compositions were analyzed by bioelectrical impedance analysis. Muscle strength was measured with the hand grip test. Demographic and migration information was obtained with a questionnaire.ResultsA total of 158 volunteers were recruited at a mean age of 48.3±11.4 years. The mean time from when they escaped from North Korea and arrived in South Korea was 5.8±4.3 years. Height, weight, and body surface area were significantly smaller in all NKRs compared to South Korean controls, except for women aged over 50 years. In females of younger ages (<50 years, NKRs with more than a 4-year stay in South Korea had a higher weight and fat mass than that of those who had a shorter stay (less than 4 years in South Korea. All NKRs had a weaker grip strength than that of the age-matched controls from South Korea.ConclusionThe NKRs showed relatively smaller physiques and weaker muscle strength than that of the South Korean controls. In younger female NKRs, shorter South Korean stay group showed small body weight and fat mass than that of longer South Korean stay group. Specific health support programs might be needed.

  20. Induction of GLUT-1 protein in adult human skeletal muscle fibers

    DEFF Research Database (Denmark)

    Gaster, M; Franch, J; Staehr, P

    2000-01-01

    fibers. Metabolic stress (obesity, non-insulin-dependent diabetes mellitus), contractile activity (training), and conditions of de- and reinnervation (amyotrophic lateral sclerosis) could not induce GLUT-1 expression in human muscle fibers. However, regenerating muscle fibers in polymyositis expressed...

  1. Skeletal muscle vasodilation during systemic hypoxia in humans.

    Science.gov (United States)

    Dinenno, Frank A

    2016-01-15

    In humans, the net effect of acute systemic hypoxia in quiescent skeletal muscle is vasodilation despite significant reflex increases in muscle sympathetic vasoconstrictor nerve activity. This vasodilation increases tissue perfusion and oxygen delivery to maintain tissue oxygen consumption. Although several mechanisms may be involved, we recently tested the roles of two endothelial-derived substances during conditions of sympathoadrenal blockade to isolate local vascular control mechanisms: nitric oxide (NO) and prostaglandins (PGs). Our findings indicate that 1) NO normally plays a role in regulating vascular tone during hypoxia independent of the PG pathway; 2) PGs do not normally contribute to vascular tone during hypoxia, however, they do affect vascular tone when NO is inhibited; 3) NO and PGs are not independently obligatory to observe hypoxic vasodilation when assessed as a response from rest to steady-state hypoxia; and 4) combined NO and PG inhibition abolishes hypoxic vasodilation in human skeletal muscle. When the stimulus is exacerbated via combined submaximal rhythmic exercise and systemic hypoxia to cause further red blood cell (RBC) deoxygenation, skeletal muscle blood flow is augmented compared with normoxic exercise via local dilator mechanisms to maintain oxygen delivery to active tissue. Data obtained in a follow-up study indicate that combined NO and PG inhibition during hypoxic exercise blunts augmented vasodilation and hyperemia compared with control (normoxic) conditions by ∼50%; however, in contrast to hypoxia alone, the response is not abolished, suggesting that other local substances are involved. Factors associated with greater RBC deoxygenation such as ATP release, or nitrite reduction to NO, or both likely play a role in regulating this response.

  2. Influence of exercise contraction mode and protein supplementation on human skeletal muscle satellite cell content and muscle fiber growth

    DEFF Research Database (Denmark)

    Farup, Jean; Rahbek, Stine Klejs; Riis, Simon

    2014-01-01

    -specific association between emergence of satellite cells (SCs), muscle growth, and remodeling in response to 12 wk unilateral resistance training performed as eccentric (Ecc) or concentric (Conc) resistance training ± whey protein (Whey, 19.5 g protein + 19.5 g glucose) or placebo (Placebo, 39 g glucose......Skeletal muscle satellite cells (SCs) are involved in remodeling and hypertrophy processes of skeletal muscle. However, little knowledge exists on extrinsic factors that influence the content of SCs in skeletal muscle. In a comparative human study, we investigated the muscle fiber type......) supplementation. Muscle biopsies (vastus lateralis) were analyzed for fiber type-specific SCs, myonuclei, and fiber cross-sectional area (CSA). Following training, SCs increased with Conc in both type I and type II fibers (P

  3. The effects of creatine ethyl ester supplementation combined with heavy resistance training on body composition, muscle performance, and serum and muscle creatine levels

    Directory of Open Access Journals (Sweden)

    Greenwood Mike

    2009-02-01

    Full Text Available Abstract Numerous creatine formulations have been developed primarily to maximize creatine absorption. Creatine ethyl ester is alleged to increase creatine bio-availability. This study examined how a seven-week supplementation regimen combined with resistance training affected body composition, muscle mass, muscle strength and power, serum and muscle creatine levels, and serum creatinine levels in 30 non-resistance-trained males. In a double-blind manner, participants were randomly assigned to a maltodextrose placebo (PLA, creatine monohydrate (CRT, or creatine ethyl ester (CEE group. The supplements were orally ingested at a dose of 0.30 g/kg fat-free body mass (approximately 20 g/day for five days followed by ingestion at 0.075 g/kg fat free mass (approximately 5 g/day for 42 days. Results showed significantly higher serum creatine concentrations in PLA (p = 0.007 and CRT (p = 0.005 compared to CEE. Serum creatinine was greater in CEE compared to the PLA (p = 0.001 and CRT (p = 0.001 and increased at days 6, 27, and 48. Total muscle creatine content was significantly higher in CRT (p = 0.026 and CEE (p = 0.041 compared to PLA, with no differences between CRT and CEE. Significant changes over time were observed for body composition, body water, muscle strength and power variables, but no significant differences were observed between groups. In conclusion, when compared to creatine monohydrate, creatine ethyl ester was not as effective at increasing serum and muscle creatine levels or in improving body composition, muscle mass, strength, and power. Therefore, the improvements in these variables can most likely be attributed to the training protocol itself, rather than the supplementation regimen.

  4. "Scientific peep show": the human body in contemporary science museums.

    Science.gov (United States)

    Canadelli, Elena

    2011-01-01

    The essay focuses on the discourse about the human body developed by contemporary science museums with educational and instructive purposes directed at the general public. These museums aim mostly at mediating concepts such as health and prevention. The current scenario is linked with two examples of past museums: the popular anatomical museums which emerged during the 19th century and the health museums thrived between 1910 and 1940. On the museological path about the human body self-care we went from the emotionally involving anatomical Venuses to the inexpressive Transparent Man, from anatomical specimens of ill organs and deformed subjects to the mechanical and electronic models of the healthy body. Today the body is made transparent by the new medical diagnostics and by the latest discoveries of endoscopy. The way museums and science centers presently display the human body involves computers, 3D animation, digital technologies, hands-on models of large size human parts.

  5. Human body segmentation via data-driven graph cut.

    Science.gov (United States)

    Li, Shifeng; Lu, Huchuan; Shao, Xingqing

    2014-11-01

    Human body segmentation is a challenging and important problem in computer vision. Existing methods usually entail a time-consuming training phase for prior knowledge learning with complex shape matching for body segmentation. In this paper, we propose a data-driven method that integrates top-down body pose information and bottom-up low-level visual cues for segmenting humans in static images within the graph cut framework. The key idea of our approach is first to exploit human kinematics to search for body part candidates via dynamic programming for high-level evidence. Then, by using the body parts classifiers, obtaining bottom-up cues of human body distribution for low-level evidence. All the evidence collected from top-down and bottom-up procedures are integrated in a graph cut framework for human body segmentation. Qualitative and quantitative experiment results demonstrate the merits of the proposed method in segmenting human bodies with arbitrary poses from cluttered backgrounds.

  6. Anabolic processes in human skeletal muscle: restoring the identities of growth hormone and testosterone.

    Science.gov (United States)

    West, Daniel W D; Phillips, Stuart M

    2010-10-01

    Testosterone supplementation acts via numerous mechanisms as a highly potent anabolic agent to skeletal muscle. Although growth hormone (GH) strongly affects collagen synthesis and lipolysis, as well as increasing lean body mass, it is not anabolic toward the contractile (ie, myofibrillar) muscle tissue in healthy individuals. However, there is a persistent belief (both in scientific literature and among recreational weightlifters) that exercise-induced release of GH and testosterone underpins muscular hypertrophy with resistance training. This is a premature assumption because although pharmacological GH supplementation can increase muscle strength or size in individuals with clinical GH deficiency, there is no evidence that transient exercise-induced changes in GH have the same effects in individuals with normal GH levels. Exercise paradigms are designed based on the assumption (not necessarily evidenced-based mechanisms) that GH and testosterone facilitate anabolic processes that lead to skeletal muscle protein accretion and hypertrophy. Our recent work disputes this assumption. Instead, our data indicate that exercise-induced hormonal elevations do not enhance intracellular markers of anabolic signaling or the acute postexercise elevation of myofibrillar protein synthesis. Furthermore, data from our training study demonstrate that exercise-induced increases in GH and testosterone availability are not necessary for and do not enhance strength and hypertrophy adaptations. Instead, our data lead us to conclude that local mechanisms that are intrinsic to the skeletal muscle tissue performing the resistive contractions (ie, weightlifting) are predominant in stimulating anabolism. The purpose of this article is 1) to provide a brief overview of the mechanisms of action of testosterone and GH; 2) to discuss the inability of physiological exercise-induced elevations in these hormones to have a measurable impact on skeletal muscle anabolism; and 3) to describe factors

  7. Proteomics of Skeletal Muscle

    DEFF Research Database (Denmark)

    Deshmukh, Atul

    2016-01-01

    Skeletal muscle is the largest tissue in the human body and plays an important role in locomotion and whole body metabolism. It accounts for ~80% of insulin stimulated glucose disposal. Skeletal muscle insulin resistance, a primary feature of Type 2 diabetes, is caused by a decreased ability...... of muscle to respond to circulating insulin. Physical exercise improves insulin sensitivity and whole body metabolism and remains one of the most promising interventions for the prevention of Type 2 diabetes. Insulin resistance and exercise adaptations in skeletal muscle might be a cause, or consequence...

  8. Therapeutic isolation and expansion of human skeletal muscle-derived stem cells for the use of muscle-nerve-blood vessel reconstitution

    Directory of Open Access Journals (Sweden)

    Tetsuro eTamaki

    2015-06-01

    Full Text Available Skeletal muscle makes up 40-50% of body mass, and is thus considered to be a good adult stem cell source for autologous therapy. Although, several stem/progenitor cells have been fractionated from mouse skeletal muscle showing a high potential for therapeutic use, it is unclear whether this is the case in human. Differentiation and therapeutic potential of human skeletal muscle-derived cells (Sk-Cs was examined. Samples (5-10 g were obtained from the abdominal and leg muscles of 36 patients (age, 17-79 years undergoing prostate cancer treatment or leg amputation surgery. All patients gave informed consent. Sk-Cs were isolated using conditioned collagenase solution, and were then sorted as CD34-/CD45-/CD29+ (Sk-DN/29+ and CD34+/CD45- (Sk-34 cells, in a similar manner as for the previous mouse Sk-Cs. Both cell fractions were appropriately expanded using conditioned culture medium for about 2 weeks. Differentiation potentials were then examined during cell culture and in vivo transplantation into the severely damaged muscles of athymic nude mice and rats. Interestingly, these two cell fractions could be divided into highly myogenic (Sk-DN/29+ and multipotent stem cell (Sk-34 fractions, in contrast to mouse Sk-Cs, which showed comparable capacities in both cells. At 6 weeks after the separate transplantation of both cell fractions, the former showed an active contribution to muscle fiber regeneration, but the latter showed vigorous engraftment to the interstitium associated with differentiation into Schwann cells, perineurial/endoneurial cells, and vascular endothelial cells and pericytes, which corresponded to previous observations with mouse SK-Cs. Importantly, mixed cultures of both cells resulted the reduction of tissue reconstitution capacities in vivo, whereas co-transplantation after separate expansion showed favorable results. Therefore, human Sk-Cs are potentially applicable to therapeutic autografts and show multiple differentiation

  9. Plantar flexor stretch reflex responses to whole body loading/unloading during human walking

    DEFF Research Database (Denmark)

    Grey, Michael James; van Doornik, Johannes; Sinkjær, Thomas

    2002-01-01

    was to investigate the contribution of load receptor feedback to the compensatory stretch reflex response. We examined the contribution of load receptor feedback to the magnitude of the short and medium latency components of the ankle plantar flexor stretch reflex responses following an unexpected dorsiflexion...... perturbation during human walking. Three body load conditions were investigated: normal body load, a 30% increase in body load, and a 30% decrease in body load. Healthy subjects walked on a treadmill at approximately 3.6 km/h with the left ankle attached to a portable stretching device. Dorsiflexion...... perturbations (8 degrees; 350-425 degrees/s) were generated during the late stance phase of gate (approximately 400 ms following heel contact). Electromyographic activity was recorded from the soleus, tibialis anterior, medial gastrocnemius, rectus femoris, and biceps femoris muscles using bipolar surface...

  10. Afferent contribution to locomotor muscle activity during unconstrained overground human walking: an analysis of triceps surae muscle fascicles.

    Science.gov (United States)

    af Klint, R; Cronin, N J; Ishikawa, M; Sinkjaer, T; Grey, M J

    2010-03-01

    Plantar flexor series elasticity can be used to dissociate muscle-fascicle and muscle-tendon behavior and thus afferent feedback during human walking. We used electromyography (EMG) and high-speed ultrasonography concomitantly to monitor muscle activity and muscle fascicle behavior in 19 healthy volunteers as they walked across a platform. On random trials, the platform was dropped (8 cm, 0.9 g acceleration) or held at a small inclination (up to +/-3 degrees in the parasagittal plane) with respect to level ground. Dropping the platform in the mid and late phases of stance produced a depression in the soleus muscle activity with an onset latency of about 50 ms. The reduction in ground reaction force also unloaded the plantar flexor muscles. The soleus muscle fascicles shortened with a minimum delay of 14 ms. Small variations in platform inclination produced significant changes in triceps surae muscle activity; EMG increased when stepping on an inclined surface and decreased when stepping on a declined surface. This sensory modulation of the locomotor output was concomitant with changes in triceps surae muscle fascicle and gastrocnemius tendon length. Assuming that afferent activity correlates to these mechanical changes, our results indicate that within-step sensory feedback from the plantar flexor muscles automatically adjusts muscle activity to compensate for small ground irregularities. The delayed onset of muscle fascicle movement after dropping the platform indicates that at least the initial part of the soleus depression is more likely mediated by a decrease in force feedback than length-sensitive feedback, indicating that force feedback contributes to the locomotor activity in human walking.

  11. ¹³C MRS reveals a small diurnal variation in the glycogen content of human thigh muscle.

    Science.gov (United States)

    Takahashi, Hideyuki; Kamei, Akiko; Osawa, Takuya; Kawahara, Takashi; Takizawa, Osamu; Maruyama, Katsuya

    2015-06-01

    There is marked diurnal variation in the glycogen content of skeletal muscles of animals, but few studies have addressed such variations in human muscles. (13)C MRS can be used to noninvasively measure the glycogen content of human skeletal muscle, but no study has explored the diurnal variations in this parameter. This study aimed to investigate whether a diurnal variation in glycogen content occurs in human muscles and, if so, to what extent it can be identified using (13)C MRS. Six male volunteers were instructed to maintain their normal diet and not to perform strenuous exercise for at least 3 days before and during the experiment. Muscle glycogen and blood glucose concentrations were measured six times in 24 h under normal conditions in these subjects. The glycogen content in the thigh muscle was determined noninvasively by natural abundance (13)C MRS using a clinical MR system at 3 T. Nutritional analysis revealed that the subjects' mean carbohydrate intake was 463 ± 137 g, being approximately 6.8 ± 2.4 g/kg body weight. The average sleeping time was 5.9 ± 1.0 h. The glycogen content in the thigh muscle at the starting point was 64.8 ± 20.6 mM. Although absolute and relative individual variations in muscle glycogen content were 7.0 ± 2.1 mM and 11.3 ± 4.6%, respectively, no significant difference in glycogen content was observed among the different time points. This study demonstrates that normal food intake (not fat and/or carbohydrate rich), sleep and other daily activities have a negligible influence on thigh muscle glycogen content, and that the diurnal variation of the glycogen content in human muscles is markedly smaller than that in animal muscles. Moreover, the present results also support the reproducibility and availability of (13)C MRS for the evaluation of the glycogen content in human muscles. Copyright © 2015 John Wiley & Sons, Ltd.

  12. Automatic Modeling of Virtual Humans and Body Clothing

    Institute of Scientific and Technical Information of China (English)

    Nadia Magnenat-Thalmann; Hyewon Seo; Frederic Cordier

    2004-01-01

    Highly realistic virtual human models are rapidly becoming commonplace in computer graphics.These models, often represented by complex shape and requiring labor-intensive process, challenge the problem of automatic modeling. The problem and solutions to automatic modeling of animatable virtual humans are studied. Methods for capturing the shape of real people, parameterization techniques for modeling static shape (the variety of human body shapes) and dynamic shape (how the body shape changes as it moves) of virtual humans are classified, summarized and compared. Finally, methods for clothed virtual humans are reviewed.

  13. The effect of perturbing body segment parameters on calculated joint moments and muscle forces during gait.

    Science.gov (United States)

    Wesseling, Mariska; de Groote, Friedl; Jonkers, Ilse

    2014-01-22

    This study examined the effect of body segment parameter (BSP) perturbations on joint moments calculated using an inverse dynamics procedure and muscle forces calculated using computed muscle control (CMC) during gait. BSP (i.e. segment mass, center of mass location (com) and inertia tensor) of the left thigh, shank and foot of a scaled musculoskeletal model were perturbed. These perturbations started from their nominal value and were adjusted to ±40% in steps of 10%, for both individual as well as combined perturbations in BSP. For all perturbations, an inverse dynamics procedure calculated the ankle, knee and hip moments based on an identical inverse kinematics solution. Furthermore, the effect of applying a residual reduction algorithm (RRA) was investigated. Muscle excitations and resulting muscle forces were calculated using CMC. The results show only a limited effect of an individual parameter perturbation on the calculated moments, where the largest effect is found when perturbing the shank com (MS(com,shank), the ratio of absolute difference in torque and relative parameter perturbation, is maximally -7.81 N m for hip flexion moment). The additional influence of perturbing two parameters simultaneously is small (MS(mass+com,thigh) is maximally 15.2 N m for hip flexion moment). RRA made small changes to the model to increase the dynamic consistency of the simulation (after RRA MS(com,shank) is maximally 5.01 N m). CMC results show large differences in muscle forces when BSP are perturbed. These result from the underlying forward integration of the dynamic equations.

  14. Moving human full body and body parts detection, tracking, and applications on human activity estimation, walking pattern and face recognition

    Science.gov (United States)

    Chen, Hai-Wen; McGurr, Mike

    2016-05-01

    We have developed a new way for detection and tracking of human full-body and body-parts with color (intensity) patch morphological segmentation and adaptive thresholding for security surveillance cameras. An adaptive threshold scheme has been developed for dealing with body size changes, illumination condition changes, and cross camera parameter changes. Tests with the PETS 2009 and 2014 datasets show that we can obtain high probability of detection and low probability of false alarm for full-body. Test results indicate that our human full-body detection method can considerably outperform the current state-of-the-art methods in both detection performance and computational complexity. Furthermore, in this paper, we have developed several methods using color features for detection and tracking of human body-parts (arms, legs, torso, and head, etc.). For example, we have developed a human skin color sub-patch segmentation algorithm by first conducting a RGB to YIQ transformation and then applying a Subtractive I/Q image Fusion with morphological operations. With this method, we can reliably detect and track human skin color related body-parts such as face, neck, arms, and legs. Reliable body-parts (e.g. head) detection allows us to continuously track the individual person even in the case that multiple closely spaced persons are merged. Accordingly, we have developed a new algorithm to split a merged detection blob back to individual detections based on the detected head positions. Detected body-parts also allow us to extract important local constellation features of the body-parts positions and angles related to the full-body. These features are useful for human walking gait pattern recognition and human pose (e.g. standing or falling down) estimation for potential abnormal behavior and accidental event detection, as evidenced with our experimental tests. Furthermore, based on the reliable head (face) tacking, we have applied a super-resolution algorithm to enhance

  15. Severely atrophic human muscle fibers with nuclear misplacement survive many years of permanent denervation

    Directory of Open Access Journals (Sweden)

    Ugo Carraro

    2016-06-01

    Full Text Available Likewise in rodents, after complete spinal cord injury (SCI the lower motor neuron (LMN denervated human muscle fibers lose completely the myofibrillar apparatus and the coil distribution of myonuclei that are relocated in groups (nuclear clumps in the center of severely atrophic muscle fibers. Up to two years of LMN denervation the muscle fibers with nuclear clumps are very seldom, but in this cohort of patients the severely atrophic muscle fibers are frequent in muscle biopsies harvested three to six years after SCI. Indeed, the percentage increased to 27 ± 9% (p< 0.001, and then abruptly decreased from the 6th year onward, when fibrosis takes over to neurogenic muscle atrophy. Immunohistochemical analyses shown that nuclear misplacements occurred in both fast and slow muscle fibers. In conclusion, human muscle fibers survive permanent denervation much longer than generally accepted and relocation of nuclei is a general behavior in long term denervated muscle fibers.

  16. Finite element modeling for predicting the contact pressure between a foam mattress and the human body in a supine position.

    Science.gov (United States)

    Lee, Wookjin; Won, Byeong Hee; Cho, Seong Wook

    2017-01-01

    In this paper, we generated finite element (FE) models to predict the contact pressure between a foam mattress and the human body in a supine position. Twenty-year-old males were used for three-dimensional scanning to produce the FE human models, which was composed of skin and muscle tissue. A linear elastic isotropic material model was used for the skin, and the Mooney-Rivlin model was used for the muscle tissue because it can effectively represent the nonlinear behavior of muscle. The contact pressure between the human model and the mattress was predicted by numerical simulation. The human models were validated by comparing the body pressure distribution obtained from the same human subject when he was lying on two different mattress types. The experimental results showed that the slope of the lower part of the mattress caused a decrease in the contact pressure at the heels, and the effect of bone structure was most pronounced in the scapula. After inserting a simple structure to function as the scapula, the contact pressure predicted by the FE human models was consistent with the experimental body pressure distribution for all body parts. These results suggest that the models proposed in this paper will be useful to researchers and designers of products related to the prevention of pressure ulcers.

  17. Activity of upper limb muscles during human walking.

    Science.gov (United States)

    Kuhtz-Buschbeck, Johann P; Jing, Bo

    2012-04-01

    The EMG activity of upper limb muscles during human gait has rarely been studied previously. It was examined in 20 normal volunteers in four conditions: walking on a treadmill (1) with unrestrained natural arm swing (Normal), (2) while volitionally holding the arms still (Held), (3) with the arms immobilized (Bound), and (4) with the arms swinging in phase with the ipsilateral legs, i.e. opposite-to-normal phasing (Anti-Normal). Normal arm swing involved weak rhythmical lengthening and shortening contractions of arm and shoulder muscles. Phasic muscle activity was needed to keep the unrestricted arms still during walking (Held), indicating a passive component of arm swing. An active component, possibly programmed centrally, existed as well, because some EMG signals persisted when the arms were immobilized during walking (Bound). Anti-Normal gait involved stronger EMG activity than Normal walking and was uneconomical. The present results indicate that normal arm swing has both passive and active components. Copyright © 2011 Elsevier Ltd. All rights reserved.

  18. Substance P stimulation of cultured human smooth muscle cells

    Energy Technology Data Exchange (ETDEWEB)

    Mitsuhashi, M.; Payan, D.G.

    1986-03-01

    Substance P (SP) has been shown to be mitogenic for cells active in the inflammatory response, such as lymphocytes and macrophages, and demonstrates vasodilatory and bronchoconstrictor properties, implicating SP receptor-mediated responses on smooth muscle cells. The effects of SP on cultured human vascular smooth muscle cell (HSMC) proliferative responses and protein synthesis were assessed by measuring the incorporation of (/sup 3/H)thymidine into DNA and (/sup 3/H)leucine into intracellular proteins, respectively. SP at concentrations of 10/sup -6/ to 10/sup -5/M stimulated a 40-50% increase in the incorporation of (/sup 3/H)thymidine in HMSC. In addition, the uptake of (/sup 3/H)leucine into HSMC proteins was increased significantly by SP over the concentration range 10/sup -11/ to 10/sup -6/M. Moreover, an enhancement of protein synthesis in HSMC by 10/sup -9/M SP was demonstrated by an increased incorporation of (/sup 35/S)methionine into cellular proteins of MW 40-30,000 daltons as assessed by autoradiographic analysis of HSMC lysates analyzed by SDS-PAGE. Furthermore, the uptake of (/sup 3/H)inositol into HSMC membrane phospholipid was increased significantly by SP in a dose-dependent manner over the concentration range 10/sup -11/ to 10/sup -6/M. Peptides such as SP which stimulate smooth muscle contraction, also demonstrate mitogenic properties on HSMC, suggesting that these cellular response shares common pathways of activation.

  19. Experimental neck muscle pain impairs standing balance in humans

    CERN Document Server

    Vuillerme, Nicolas; 10.1007/s00221-008-1639-7

    2009-01-01

    Impaired postural control has been reported in patients with chronic neck pain of both traumatic and non-traumatic etiologies, but whether painful stimulation of neck muscle per se can affect balance control during quiet standing in humans remains unclear. The purpose of the present experiment was thus to investigate the effect of experimental neck muscle pain on standing balance in young healthy adults. To achieve this goal, 16 male university students were asked to stand upright as still as possible on a force platform with their eyes closed in two conditions of No pain and Pain of the neck muscles elicited by experimental painful electrical stimulation. Postural control and postural performance were assessed by the displacements of the center of foot pressure (CoP) and of the center of mass (CoM), respectively. The results showed increased CoP and CoM displacements variance, range, mean velocity, and mean and median frequencies in the Pain relative to the No pain condition. The present findings emphasize t...

  20. Interleukin-6 directly increases glucose metabolism in resting human skeletal muscle

    DEFF Research Database (Denmark)

    Glund, Stephan; Deshmukh, Atul; Long, Yun Chau

    2007-01-01

    suggested to promote insulin-mediated glucose utilization. In this study, we determined the direct effects of IL-6 on glucose transport and signal transduction in human skeletal muscle. Skeletal muscle strips were prepared from vastus lateralis biopsies obtained from 22 healthy men. Muscle strips were...... incubated with or without IL-6 (120 ng/ml). We found that IL-6 increased glucose transport in human skeletal muscle 1.3-fold (P ... exposure increases glucose metabolism in resting human skeletal muscle. Insulin-stimulated glucose transport and insulin signaling were unchanged after IL-6 exposure....

  1. Research on Dynamic Model of the Human Body

    Institute of Scientific and Technical Information of China (English)

    ZHANG Chun-lin; WANG Guang-quan; LU Dun-yong

    2005-01-01

    After summarizing the current situation of the research on human body modeling, a new dynamic model containing 5 equivalent masses has been proposed and the corresponding dynamic equations has been deduced too. By using this new model, more detailed information about the situation of the human body under impact and vibration can be obtained. The new model solves the problem that transmission functions of forces inside the human body can't be deduced by using 3-equivalent-mass model. It will find its usage in many applications.

  2. Globalization and the trade in human body parts.

    Science.gov (United States)

    Harrison, T

    1999-02-01

    Since the early 1980s, the number and variety of organ transplantations has increased enormously worldwide. Accompanying this increase has been the emergence of a market for human body parts. This paper argues that, while the trade in human body parts is conditioned by technological advances, it must be understood in the broader context of globalization, specifically the extension and intensification of a capitalist mode of exchange. In this regard, it is argued that the trade in human body parts mirrors the "normal" system of unequal exchanges that mark other forms of trade between the developed and undeveloped regions of the world.

  3. Gender Recognition from Unconstrained and Articulated Human Body

    Directory of Open Access Journals (Sweden)

    Qin Wu

    2014-01-01

    human body images acquired from an unconstrained environment in the real world. A systematic study of some critical issues in body-based gender recognition, such as which body parts are informative, how many body parts are needed to combine together, and what representations are good for articulated body-based gender recognition, is also presented. This paper also pursues data fusion schemes and efficient feature dimensionality reduction based on the partial least squares estimation. Extensive experiments are performed on two unconstrained databases which have not been explored before for gender recognition.

  4. Body Basics

    Science.gov (United States)

    ... more about how the body works, what basic human anatomy is, and what happens when parts of the body don't function properly. Blood Bones, Muscles, and Joints Brain and Nervous System Digestive System Endocrine System Eyes Female Reproductive System Heart and Circulatory System Immune ...

  5. Stretch reflex instability compared in three different human muscles.

    Science.gov (United States)

    Durbaba, R; Taylor, A; Manu, C A; Buonajuti, M

    2005-06-01

    The possibility of causing instability in the stretch reflex has been examined in three different human muscles: biceps, first dorsal interosseous (FDI) of the hand and digastric. Tremor recorded as fluctuation of isometric force was compared with that occurring during contraction against a spring load. The spring compliance was selected to make the natural frequency of the part in each case appropriate for oscillations in the short latency stretch reflex. A computer model of the whole system was used to predict the frequency at which oscillations should be expected and to estimate the reflex gain required in each case to cause sustained oscillations. Estimates were computed of the autospectra of the force records and of the rectified surface EMG signals and of the coherence functions. Normal subjects showed no evidence of a distinct spectral peak during isometric recording from any of the three muscles. However, in anisometric conditions regular oscillations in force occurred in biceps, but not in FDI or digastric. The oscillations in biceps at 8-9 Hz were accompanied by similar oscillations in the EMG which were highly coherent with the force signal. The results are consistent with the presence of a strong segmental stretch reflex effect in biceps and weak or absent reflex in FDI. Digastric is known to contain no muscle spindles and therefore to lack a stretch reflex. In two subjects who volunteered that they had more tremor than normal, but had no known neurological abnormality, there was a distinct peak in the force spectrum at 8-9 Hz in biceps and FDI in isometric conditions with coherent EMG activity. The peak increased in size in anisometric conditions in biceps but not in FDI. This component appears to be of central rather than of reflex origin. No equivalent component was found in digastric records. The results are discussed in relation to the possible role of the short latency stretch reflex in the genesis of physiological tremor in different muscles.

  6. The functional architecture of the human body: assessing body representation by sorting body parts and activities.

    Science.gov (United States)

    Bläsing, Bettina; Schack, Thomas; Brugger, Peter

    2010-05-01

    We investigated mental representations of body parts and body-related activities in two subjects with congenitally absent limbs (one with, the other without phantom sensations), a wheelchair sports group of paraplegic participants, and two groups of participants with intact limbs. To analyse mental representation structures, we applied Structure Dimensional Analysis. Verbal labels indicating body parts and related activities were presented in randomized lists that had to be sorted according to a hierarchical splitting paradigm. Participants were required to group the items according to whether or not they were considered related, based on their own body perception. Results of the groups of physically intact and paraplegic participants revealed separate clusters for the lower body, upper body, fingers and head. The participant with congenital phantom limbs also showed a clear separation between upper and lower body (but not between fingers and hands). In the participant without phantom sensations of the absent arms, no such modularity emerged, but the specific practice of his right foot in communication and daily routines was reflected. Sorting verbal labels of body parts and activities appears a useful method to assess body representation in individuals with special body anatomy or function and leads to conclusions largely compatible with other assessment procedures.

  7. Expression of perilipins in human skeletal muscle in vitro and in vivo in relation to diet, exercise and energy balance

    DEFF Research Database (Denmark)

    Gjelstad, I M F; Haugen, F; Gulseth, H L

    2011-01-01

    , enhanced the expression of perilipin 2 and 3. Perilipin 1 mRNA correlated positively with body fat mass, whereas none of the perilipins were associated with insulin sensitivity. In conclusion, all perilipins mRNAs were expressed in human skeletal muscle. Diet as well as endurance exercise modulated......The perilipin proteins enclose intracellular lipid droplets. We describe the mRNA expression of the five perilipins in human skeletal muscle in relation to fatty acid supply, exercise and energy balance. We observed that all perilipins were expressed in skeletal muscle biopsies with the highest m......RNA levels of perilipin 2, 4 and 5. Cultured myotubes predominantly expressed perilipin 2 and 3. In vitro, incubation of myotubes with fatty acids enhanced mRNA expression of perilipin 1, 2 and 4. In vivo, low fat diet increased mRNA levels of perilipin 3 and 4. Endurance training, but not strength training...

  8. Numerical Modeling of Electromagnetic Field Effects on the Human Body

    Directory of Open Access Journals (Sweden)

    Zuzana Psenakova

    2006-01-01

    Full Text Available Interactions of electromagnetic field (EMF with environment and with tissue of human beings are still under discussion and many research teams are investigating it. The human simulation models are used for biomedical research in a lot of areas, where it is advantage to replace real human body (tissue by the numerical model. Biological effects of EMF are one of the areas, where numerical models are used with many advantages. On the other side, this research is very specific and it is always quite hard to simulate realistic human tissue. This paper deals with different possibilities of numerical modelling of electromagnetic field effects on the human body (especially calculation of the specific absorption rate (SAR distribution in human body and thermal effect.

  9. A real-time system for biomechanical analysis of human movement and muscle function.

    Science.gov (United States)

    van den Bogert, Antonie J; Geijtenbeek, Thomas; Even-Zohar, Oshri; Steenbrink, Frans; Hardin, Elizabeth C

    2013-10-01

    Mechanical analysis of movement plays an important role in clinical management of neurological and orthopedic conditions. There has been increasing interest in performing movement analysis in real-time, to provide immediate feedback to both therapist and patient. However, such work to date has been limited to single-joint kinematics and kinetics. Here we present a software system, named human body model (HBM), to compute joint kinematics and kinetics for a full body model with 44 degrees of freedom, in real-time, and to estimate length changes and forces in 300 muscle elements. HBM was used to analyze lower extremity function during gait in 12 able-bodied subjects. Processing speed exceeded 120 samples per second on standard PC hardware. Joint angles and moments were consistent within the group, and consistent with other studies in the literature. Estimated muscle force patterns were consistent among subjects and agreed qualitatively with electromyography, to the extent that can be expected from a biomechanical model. The real-time analysis was integrated into the D-Flow system for development of custom real-time feedback applications and into the gait real-time analysis interactive lab system for gait analysis and gait retraining.

  10. Standoff Human Identification Using Body Shape

    Energy Technology Data Exchange (ETDEWEB)

    Matzner, Shari; Heredia-Langner, Alejandro; Amidan, Brett G.; Boettcher, Evelyn J.; Lochtefeld, Darrell; Webb, Timothy

    2015-09-01

    The ability to identify individuals is a key component of maintaining safety and security in public spaces and around critical infrastructure. Monitoring an open space is challenging because individuals must be identified and re-identified from a standoff distance nonintrusively, making methods like fingerprinting and even facial recognition impractical. We propose using body shape features as a means for identification from standoff sensing, either complementing other identifiers or as an alternative. An important challenge in monitoring open spaces is reconstructing identifying features when only a partial observation is available, because of the view-angle limitations and occlusion or subject pose changes. To address this challenge, we investigated the minimum number of features required for a high probability of correct identification, and we developed models for predicting a key body feature—height—from a limited set of observed features. We found that any set of nine randomly selected body measurements was sufficient to correctly identify an individual in a dataset of 4426 subjects. For predicting height, anthropometric measures were investigated for correlation with height. Their correlation coefficients and associated linear models were reported. These results—a sufficient number of features for identification and height prediction from a single feature—contribute to developing systems for standoff identification when views of a subject are limited.

  11. Four-week cold acclimation in adult humans shifts uncoupling thermogenesis from skeletal muscles to brown adipose tissue.

    Science.gov (United States)

    Blondin, Denis P; Daoud, Amani; Taylor, Taryn; Tingelstad, Hans C; Bézaire, Véronic; Richard, Denis; Carpentier, André C; Taylor, Albert W; Harper, Mary-Ellen; Aguer, Céline; Haman, François

    2017-03-15

    Muscle-derived thermogenesis during acute cold exposure in humans consists of a combination of cold-induced increases in skeletal muscle proton leak and shivering. Daily cold exposure results in an increase in brown adipose tissue oxidative capacity coupled with a decrease in the cold-induced skeletal muscle proton leak and shivering intensity. Improved coupling between electromyography-determined muscle activity and whole-body heat production following cold acclimation suggests a maintenance of ATPase-dependent thermogenesis and decrease in skeletal muscle ATPase independent thermogenesis. Although daily cold exposure did not change the fibre composition of the vastus lateralis, the fibre composition was a strong predictor of the shivering pattern evoked during acute cold exposure. We previously showed that 4 weeks of daily cold exposure in humans can increase brown adipose tissue (BAT) volume by 45% and oxidative metabolism by 182%. Surprisingly, we did not find a reciprocal reduction in shivering intensity when exposed to a mild cold (18°C). The present study aimed to determine whether changes in skeletal muscle oxidative metabolism or shivering activity could account for these unexpected findings. Nine men participated in a 4 week cold acclimation intervention (10°C water circulating in liquid-conditioned suit, 2 h day(-1) , 5 days week(-1) ). Shivering intensity and pattern were measured continuously during controlled cold exposure (150 min at 4 °C) before and after the acclimation. Muscle biopsies from the m. vastus lateralis were obtained to measure oxygen consumption rate and proton leak of permeabilized muscle fibres. Cold acclimation elicited a modest 21% (P cold acclimation abolished the acute cold-induced increase in proton leak. Although daily cold exposure did not change the fibre composition of the m. vastus lateralis, fibre composition was a strong predictor of the shivering pattern evoked during acute cold. We conclude that muscle

  12. Erythropoietin receptor in human skeletal muscle and the effects of acute and long-term injections with recombinant human erythropoietin on the skeletal muscle

    DEFF Research Database (Denmark)

    Lundby, Carsten; Hellsten, Ylva; Jensen, Mie B. F.;

    2008-01-01

    The presence and potential physiological role of the erythropoietin receptor (Epo-R) were examined in human skeletal muscle. In this study we demonstrate that Epo-R is present in the endothelium, smooth muscle cells, and in fractions of the sarcolemma of skeletal muscle fibers. To study...... the potential effects of Epo in human skeletal muscle, two separate studies were conducted: one to study the acute effects of a single Epo injection on skeletal muscle gene expression and plasma hormones and another to study the effects of long-term (14 wk) Epo treatment on skeletal muscle structure. Subjects...... (n = 11) received a single Epo injection of 15,000 IU (double blinded, cross over, placebo). A single Epo injection reduced myoglobin and increased transferrin receptor and MRF-4 mRNA content within 10 h after injection. Plasma hormones remained unaltered. Capillarization and fiber hypertrophy...

  13. Altered skeletal muscle fiber composition and size precede whole-body insulin resistance in young men with low birth weight

    DEFF Research Database (Denmark)

    Jensen, Christine B; Storgaard, Heidi; Madsbad, Sten

    2007-01-01

    associated with LBW. DESIGN AND SUBJECTS: Vastus lateralis muscle was obtained by percutaneous biopsy from 20 healthy 19-yr-old men with birth weights at 10th percentile or lower for gestational age (LBW) and 20 normal birth weight controls, matched for body fat, physical fitness, and whole-body glucose...

  14. No Change of Body Mass, Fat Mass, and Skeletal Muscle Mass in Ultraendurance Swimmers after 12 Hours of Swimming

    Science.gov (United States)

    Knechtle, Beat; Knechtle, Patrizia; Kaul, Rene; Kohler, Gotz

    2009-01-01

    We evaluated whether ultraendurance swimmers suffer a change of body mass, fat mass, skeletal muscle mass, total body water, and specific gravity of urine during a 12-hr swim in 12 male Caucasian ultraswimmers. Proton nuclear magnetic resonance of urine samples before and after the race was performed to detect alanine, lactate, and…

  15. Dynamic Human Body Modeling Using a Single RGB Camera

    Directory of Open Access Journals (Sweden)

    Haiyu Zhu

    2016-03-01

    Full Text Available In this paper, we present a novel automatic pipeline to build personalized parametric models of dynamic people using a single RGB camera. Compared to previous approaches that use monocular RGB images, our system can model a 3D human body automatically and incrementally, taking advantage of human motion. Based on coarse 2D and 3D poses estimated from image sequences, we first perform a kinematic classification of human body parts to refine the poses and obtain reconstructed body parts. Next, a personalized parametric human model is generated by driving a general template to fit the body parts and calculating the non-rigid deformation. Experimental results show that our shape estimation method achieves comparable accuracy with reconstructed models using depth cameras, yet requires neither user interaction nor any dedicated devices, leading to the feasibility of using this method on widely available smart phones.

  16. Dynamic Human Body Modeling Using a Single RGB Camera.

    Science.gov (United States)

    Zhu, Haiyu; Yu, Yao; Zhou, Yu; Du, Sidan

    2016-03-18

    In this paper, we present a novel automatic pipeline to build personalized parametric models of dynamic people using a single RGB camera. Compared to previous approaches that use monocular RGB images, our system can model a 3D human body automatically and incrementally, taking advantage of human motion. Based on coarse 2D and 3D poses estimated from image sequences, we first perform a kinematic classification of human body parts to refine the poses and obtain reconstructed body parts. Next, a personalized parametric human model is generated by driving a general template to fit the body parts and calculating the non-rigid deformation. Experimental results show that our shape estimation method achieves comparable accuracy with reconstructed models using depth cameras, yet requires neither user interaction nor any dedicated devices, leading to the feasibility of using this method on widely available smart phones.

  17. Gender Recognition from Unconstrained and Articulated Human Body

    OpenAIRE

    Qin Wu; Guodong Guo

    2014-01-01

    Gender recognition has many useful applications, ranging from business intelligence to image search and social activity analysis. Traditional research on gender recognition focuses on face images in a constrained environment. This paper proposes a method for gender recognition in articulated human body images acquired from an unconstrained environment in the real world. A systematic study of some critical issues in body-based gender recognition, such as which body parts are informative, ho...

  18. Effects Of Whole Body Vibration On Vertical Jump Performance Following Exercise Induced Muscle Damage

    Directory of Open Access Journals (Sweden)

    Nicole C. Dabbs

    2014-01-01

    Full Text Available Enhancing vertical jump performance is critical for many sports. Following high intensity training, individuals often experience exercise induced muscle damage (EIMD. Many recovery modalities have been tested with conflicting results. The purpose of this investigation was to determine the effect of whole-body vibration (WBV on vertical jump performance following EIMD. 27 females volunteered for 7 sessions and were randomly assigned to a treatment or control group and administered each testing day. Vertical jump performance was assessed via vertical jump height (VJH, peak power output (PPO, rate of force development (RFD, relative ground reaction force (GRFz, and peak activation ratio of the vastus medialis (VM via electromyography (EMG before and after 3 days of EIMD via split squats. Two testing sets were collected each day, consisting of pre measures followed by WBV or control, and then post second measures. A 2x8 (group x time mixed factor analysis of variance (ANOVA was conducted for each variable. No significant interactions or group differences were found in any variable. Significant main effects for time were found in any variable, indicating performance declined following muscle damage. These results indicate that WBV does not aid in muscle recovery or vertical jump performance following EIMD.

  19. The Effect of Whole-body Vibration on Muscle Activity in Active and Inactive Subjects.

    Science.gov (United States)

    Lienhard, K; Vienneau, J; Friesenbichler, B; Nigg, S; Meste, O; Nigg, B M; Colson, S S

    2015-06-01

    The purpose of this study was to compare lower limb muscle activity between physically active and inactive individuals during whole-body vibration exercises. Additionally, transmissibility of the vertical acceleration to the head was quantified. 30 active and 28 inactive participants volunteered to stand in a relaxed (20°) and a squat (60°) position on a side-alternating WBV platform that induced vibrations at 16 Hz and 4 mm amplitude. Surface electromyography (sEMG) was measured in selected lower limb muscles and was normalized to the corresponding sEMG recorded during a maximal voluntary contraction. The vertical acceleration on the head was evaluated and divided by the vertical platform acceleration to obtain transmissibility values. Control trials without vibration were also assessed. The outcomes of this study showed that (1) WBV significantly increased muscle activity in the active (absolute increase: +7%, P 0.05). However, (3), transmissibility to the head was greater in the active (0.080) than the inactive participants (0.065, P active counterparts, but are at lower risk for potential side-effects of vibration exposure. © Georg Thieme Verlag KG Stuttgart · New York.

  20. Effects of lubiprostone on human uterine smooth muscle cells.

    Science.gov (United States)

    Cuppoletti, John; Malinowska, Danuta H; Chakrabarti, Jayati; Ueno, Ryuji

    2008-06-01

    Lubiprostone, a bicyclic fatty acid derivative and member of a new class of compounds called prostones, locally activates ClC-2 Cl(-) channels without activation of prostaglandin receptors. The present study was specifically designed to test and compare lubiprostone and prostaglandin effects at the cellular level using human uterine smooth muscle cells. Effects on [Ca(2+)](i), membrane potential and [cAMP](i) in human uterine smooth muscle cells were measured. 10 nM lubiprostone significantly decreased [Ca(2+)](i) from 188 to 27 nM, which was unaffected by 100 nM SC-51322, a prostaglandin EP receptor antagonist. In contrast 10nM PGE(2) and PGE(1) both increased [Ca(2+)](i) 3-5-fold which was blocked by SC-51322. Similarly, lubiprostone and prostaglandins had opposite/different effects on membrane potential and [cAMP](i). Lubiprostone caused SC-51322-insensitive membrane hyperpolarization and no effect on [cAMP](i). PGE(2) and PGE(1) both caused SC-51322-sensitive membrane depolarization and increased [cAMP](i). Lubiprostone has fundamentally different cellular effects from prostaglandins that are not mediated by EP receptors.

  1. Individualized Human CAD Models: Anthropmetric Morphing and Body Tissue Layering

    Science.gov (United States)

    2014-07-31

    torso sub-assembly may have more fat in the abdomen than in the chest. A study 18 that could help refine this feature is being developed by the US...responses to various ensembles being developed, taking 3 into account human characteristics (height, weight, body fat , etc.), physical activity levels...model of the human body in a CAD (Computer- Aided Design) format which includes both surface features as well as internal composition, e.g., the fat

  2. Whole-body vibration training induces hypertrophy of the human patellar tendon.

    Science.gov (United States)

    Rieder, F; Wiesinger, H-P; Kösters, A; Müller, E; Seynnes, O R

    2016-08-01

    Animal studies suggest that regular exposure to whole-body vibration (WBV) induces an anabolic response in bone and tendon. However, the effects of this type of intervention on human tendon properties and its influence on the muscle-tendon unit function have never been investigated. The aim of this study was to investigate the effect of WBV training on the patellar tendon mechanical, material and morphological properties, the quadriceps muscle architecture and the knee extension torque-angle relationship. Fifty-five subjects were randomized into either a vibration, an active control, or an inactive control group. The active control subjects performed isometric squats on a vibration platform without vibration. Muscle and tendon properties were measured using ultrasonography and dynamometry. Vibration training induced an increase in proximal (6.3%) and mean (3.8%) tendon cross-sectional area, without any appreciable change in tendon stiffness and modulus or in muscle architectural parameters. Isometric torque at a knee angle of 90° increased in active controls (6.7%) only and the torque-angle relation remained globally unchanged in all groups. The present protocol did not appreciably alter knee extension torque production or the musculo-tendinous parameters underpinning this function. Nonetheless, this study shows for the first time that WBV elicits tendon hypertrophy in humans.

  3. Effects of real and sham whole-body mechanical vibration on spinal excitability at rest and during muscle contraction.

    Science.gov (United States)

    Hortobágyi, T; Rider, P; DeVita, P

    2014-12-01

    We examined the effects of whole-body mechanical vibration (WBV) on indices of motoneuronal excitability at rest and during muscle contraction in healthy humans. Real and sham WBV at 30 Hz had no effect on reflexes measured during muscle contraction. Real WBV at 30 and 50 Hz depressed the H-reflex ∼45%. These depressions diminished across the five inter-bout rest intervals. The depression converted to 27% and 7% facilitation over the 15-min long recovery period following real WBV at 30 and 50 Hz, respectively. The depression, measured during the inter-bout rest, correlated r = 0.48 (P = 0.007) with the subsequent facilitation, measured during the follow-up. The depression produced by sham vs real WBV was significant but less (23%), recovered faster, and the facilitation was absent in the 15-min long follow-up period. WBV produced time-varying depression followed by facilitation of the H-reflex at rest. A lack of change in volitional wave suggests that WBV did not affect the efferent neural drive.

  4. Series elasticity of the human triceps surae muscle : Measurement by controlled-release vs. resonance methods.

    NARCIS (Netherlands)

    Hof, AL; Boom, H; Robinson, C; Rutten, W; Neuman, M; Wijkstra, H

    1997-01-01

    With a newly developed Controlled-Release Ergometer the complete characteristic of the series elastic component can be measured in human muscles. Previous estimates were based on the resonance method: muscle elasticity was assessed from the resonance frequency of the muscle elasticity connected to a

  5. [Research progress on free radicals in human body].

    Science.gov (United States)

    Wang, Q B; Xu, F P; Wei, C X; Peng, J; Dong, X D

    2016-08-10

    Free radicals are the intermediates of metabolism, widely exist in the human bodies. Under normal circumstances, the free radicals play an important role in the metabolic process on human body, cell signal pathway, gene regulation, induction of cell proliferation and apoptosis, so as to maintain the normal growth and development of human body and to inhibit the growth of bacteria, virus and cancer. However, when organic lesion occurs affected by external factors or when equilibrium of the free radicals is tipped in the human body, the free radicals will respond integratedly with lipids, protein or nucleic acid which may jeopardize the health of human bodies. This paper summarizes the research progress of the free radicals conducted in recent years, in relations to the perspective of the types, origins, test methods of the free radicals and their relationship with human's health. In addition, the possible mechanisms of environmental pollutants (such as polycyclic aromatic hydrocarbons) mediating oxidative stress and free radicals scavenging in the body were also summarized.

  6. LOCALISED MUSCLE TISSUE OXYGENATION DURING DYNAMIC EXERCISE WITH WHOLE BODY VIBRATION

    Directory of Open Access Journals (Sweden)

    Daniel Robbins

    2012-06-01

    Full Text Available Despite increasing use of whole body vibration during exercise an understanding of the exact role of vibration and the supporting physiological mechanisms is still limited. An important aspect of exercise analysis is the utilisation of oxygen, however, there have been limited studies considering tissue oxygenation parameters, particularly during dynamic whole body vibration (WBV exercise. The aim of this study was to determine the effect of adding WBV during heel raise exercises and assessing changes in tissue oxygenation parameters of the lateral gastrocnemius using Near Infra Red Spectroscopy (NIRS. Twenty healthy subjects completed ten alternating sets of 15 heel raises (vibration vs. no vibration. Synchronous oxygenation and motion data were captured prior to exercise to determine baseline levels, for the duration of the exercise and 20 sec post exercise for the recovery period. Both vibration and no vibration conditions elicited a characteristic increase in deoxyhaemoglobin and decreases in oxyhaemoglobin, total haemoglobin, tissue oxygenation index and normalised tissue haemoglobin index which are indicative of local tissue hypoxia. However, the addition of vibration elicited significantly lower (p < 0. 001 depletions in oxyhaemoglobin, total haemoglobin, normalised tissue haemoglobin index but no significant differences in deoxyhaemoglobin. These findings suggest that addition of vibration to exercise does not increase the cost of the exercise for the lateral gastrocnemius muscle, but does decrease the reduction in local muscle oxygenation parameters, potentially resulting from increased blood flow to the calf or a vasospastic response in the feet. However, further studies are needed to establish the mechanisms underlying these findings

  7. Evaluation of upper body muscle activity during cardiopulmonary resuscitation performance in simulated microgravity

    Science.gov (United States)

    Waye, A. B.; Krygiel, R. G.; Susin, T. B.; Baptista, R.; Rehnberg, L.; Heidner, G. S.; de Campos, F.; Falcão, F. P.; Russomano, T.

    2013-09-01

    Performance of efficient single-person cardiopulmonary resuscitation (CPR) is vital to maintain cardiac and cerebral perfusion during the 2-4 min it takes for deployment of advanced life support during a space mission. The aim of the present study was to investigate potential differences in upper body muscle activity during CPR performance at terrestrial gravity (+1Gz) and in simulated microgravity (μG). Muscle activity of the triceps brachii, erector spinae, rectus abdominis and pectoralis major was measured via superficial electromyography in 20 healthy male volunteers. Four sets of 30 external chest compressions (ECCs) were performed on a mannequin. Microgravity was simulated using a body suspension device and harness; the Evetts-Russomano (ER) method was adopted for CPR performance in simulated microgravity. Heart rate and perceived exertion via Borg scores were also measured. While a significantly lower depth of ECCs was observed in simulated microgravity, compared with +1Gz, it was still within the target range of 40-50 mm. There was a 7.7% decrease of the mean (±SEM) ECC depth from 48 ± 0.3 mm at +1Gz, to 44.3 ± 0.5 mm during microgravity simulation (p muscular and cardiovascular deconditioning that occurs during space travel.

  8. Relations Between Lower Body Isometric Muscle Force Characteristics and Start Performance in Elite Male Sprint Swimmers

    Directory of Open Access Journals (Sweden)

    Igor Beretić

    2013-12-01

    Full Text Available The aim of the present study was twofold. The first aim was to examine the influence of absolute and relative lower body muscle force on kinematic component which determine the start performance. The second aim was to create multiregressional model which could use as a tool for swimming coaches with the purpose to start performance control and improvement. Twenty seven high-level trained male competitive swimmers all members of the Serbian National Youth and Senior Swimming Team (Age = 21.1 ± 4.3 yrs., Height = 1. 89 ± 0.10 m, Weight = 81.6 ± 8.4 kg, 50m freestyle - long course = 24.36 ± 0.86 s performed two trials of standing leg extensors isometric muscle force testing and three swimming start trials corresponding to 10m distance. The average start time significantly correlated with variables of leg extensors maximum voluntary force (Fmax, r = -0.559, p = 0.002, leg extensors relative muscle voluntary force (Frel, r = -0.727, p < 0.001, leg extensors specific rate of force development (RFD50%, r = -0.338, p = 0.047 and leg extensors relative value of specific rate of force development (RFD50%rel, r = -0.402, p = 0.040. Regression equation for t10m prediction was defined by following variables: maximum voluntary isometric force of leg extensors muscles at absolute and relative level (Fmax and Frel, as well as a specific rate of force development of the same muscle groups (RFD50% and RFD50%rel at absolute and relative level too with 74.4% of explained variance. Contractile abilities indicators of the leg extensors muscles included consideration: Fmax, RFD50%, Frel and RFD50%rel showed significant correlation with swimming start times on 10m. Additionally, the results suggest that swimmers, who possess greater isometric maximum force and specific rate of force development at absolute and relative levels, tend to be able to swim faster on initial 10m swim start perforamnce.

  9. Automated analysis of whole skeletal muscle for muscular atrophy detection of ALS in whole-body CT images: preliminary study

    Science.gov (United States)

    Kamiya, Naoki; Ieda, Kosuke; Zhou, Xiangrong; Yamada, Megumi; Kato, Hiroki; Muramatsu, Chisako; Hara, Takeshi; Miyoshi, Toshiharu; Inuzuka, Takashi; Matsuo, Masayuki; Fujita, Hiroshi

    2017-03-01

    Amyotrophic lateral sclerosis (ALS) causes functional disorders such as difficulty in breathing and swallowing through the atrophy of voluntary muscles. ALS in its early stages is difficult to diagnose because of the difficulty in differentiating it from other muscular diseases. In addition, image inspection methods for aggressive diagnosis for ALS have not yet been established. The purpose of this study is to develop an automatic analysis system of the whole skeletal muscle to support the early differential diagnosis of ALS using whole-body CT images. In this study, the muscular atrophy parts including ALS patients are automatically identified by recognizing and segmenting whole skeletal muscle in the preliminary steps. First, the skeleton is identified by its gray value information. Second, the initial area of the body cavity is recognized by the deformation of the thoracic cavity based on the anatomical segmented skeleton. Third, the abdominal cavity boundary is recognized using ABM for precisely recognizing the body cavity. The body cavity is precisely recognized by non-rigid registration method based on the reference points of the abdominal cavity boundary. Fourth, the whole skeletal muscle is recognized by excluding the skeleton, the body cavity, and the subcutaneous fat. Additionally, the areas of muscular atrophy including ALS patients are automatically identified by comparison of the muscle mass. The experiments were carried out for ten cases with abnormality in the skeletal muscle. Global recognition and segmentation of the whole skeletal muscle were well realized in eight cases. Moreover, the areas of muscular atrophy including ALS patients were well identified in the lower limbs. As a result, this study indicated the basic technology to detect the muscle atrophy including ALS. In the future, it will be necessary to consider methods to differentiate other kinds of muscular atrophy as well as the clinical application of this detection method for early ALS

  10. Teaching exploration and practice of the human body structure course

    Institute of Scientific and Technical Information of China (English)

    Feng LI; Ming-feng CHEN; Wen-long DING

    2015-01-01

    In the 21 st century,the medical model has transformed from the biological model to the biopsycho-social medical model. The transformation of medical model raises higher requirements for the training of medical staff. Comprehensive promotion of the reform of medical education has become the consensus and trend,which breeds the integrated medical teaching that is based on modules and organ systems. As one of eight integrated modules,the human body structure course of Shanghai Jiao Tong University School of Medicine introduces morphological structures of normal human organs according to function systems( such as locomotor system,digestive system,angiological system,and nervous system) of human organs and parts of human body. This course endeavors to integrate theories with practices,contents of disciplines of basic medicine,and basic medicine with clinical medicine. The human body structure course combines basic medicine with clinical medicine and is an important part of medical science.

  11. Effects of whole-body vibration on muscle strength and power of elderly: A systematic review

    Directory of Open Access Journals (Sweden)

    Monique Opuszcka Campos

    2014-02-01

    Full Text Available The aim of this systematic review was to summarize available scientific evidence on the utilization of whole body vibration as an alternative method to promote effective modifications on muscle strength and power in the aging population.  Scientific studies were retrieved from the following databases: Medline, Scielo, Lillacs, Cochrane Library, PEDro and Science Citation Index. The PEDro scale was used to assess the quality of the included studies, while content went through a critical analysis. From the 91 studies retrieved, 75 were excluded and 16 attended the selection criteria. From the16, the majority (68.8% presented from moderate to high methodological quality. Whole-body vibration associated to both isometric and dynamic exercises seemed to constitute an alternative for therapeutic intervention to improve muscular strength and power of healthy elderly. However, due to the characteristics of the designs of the studies reviewed and the threats to their internal validity (i.e., the absence of the control condition to the vibratory stimulus it was challenging to establish the additional effects of the whole-body vibration on the target population. Divergent findings were found for the whole-body vibration effect on muscular power. It is still necessary to conduct randomized control trials to establish the real effectiveness of this kind of intervention.

  12. Expression profiles of muscle disease-associated genes and their isoforms during differentiation of cultured human skeletal muscle cells

    Directory of Open Access Journals (Sweden)

    Abdul-Hussein Saba

    2012-12-01

    Full Text Available Abstract Background The formation of contractile myofibrils requires the stepwise onset of expression of muscle specific proteins. It is likely that elucidation of the expression patterns of muscle-specific sarcomeric proteins is important to understand muscle disorders originating from defects in contractile sarcomeric proteins. Methods We investigated the expression profile of a panel of sarcomeric components with a focus on proteins associated with a group of congenital disorders. The analyses were performed in cultured human skeletal muscle cells during myoblast proliferation and myotube development. Results Our culture technique resulted in the development of striated myotubes and the expression of adult isoforms of the sarcomeric proteins, such as fast TnI, fast TnT, adult fast and slow MyHC isoforms and predominantly skeletal muscle rather than cardiac actin. Many proteins involved in muscle diseases, such as beta tropomyosin, slow TnI, slow MyBPC and cardiac TnI were readily detected in the initial stages of muscle cell differentiation, suggesting the possibility of an early role for these proteins as constituent of the developing contractile apparatus during myofibrillogenesis. This suggests that in disease conditions the mechanisms of pathogenesis for each of the mutated sarcomeric proteins might be reflected by altered expression patterns, and disturbed assembly of cytoskeletal, myofibrillar structures and muscle development. Conclusions In conclusion, we here confirm that cell cultures of human skeletal muscle are an appropriate tool to study developmental stages of myofibrillogenesis. The expression of several disease-associated proteins indicates that they might be a useful model system for studying the pathogenesis of muscle diseases caused by defects in specific sarcomeric constituents.

  13. Electric Wheelchair Controlled by Human Body Motion Interface

    Science.gov (United States)

    Yokota, Sho; Hashimoto, Hiroshi; Ohyama, Yasuhiro; She, Jin-Hua

    This research studies the possibility of an intuitive interface for an electric wheelchair by using human body except hands. For this purpose, we focused on the human body motion which has relation to actions or behavior. This motion comes from the human stabilization function for holding expectable collapsing caused by voluntary motion. Thus this motion is considered as a kind of characteristics of human motion, and is linked to intentions unconsciously. Therefore, the interface which does not require conscious and complex motion is realized by applying this human body motion to the interface of electric wheelchair. In this paper, first, we did experiment to search a part which vividly shows the pressure change on the seat. As a result, it was confirmed that pressure change of the seat back vividly shows the human body motion. Next, we designed the prototype based on this evidence. Finally, experiment was conducted by using 10 subjects and SD method to evaluate feeling of operation. For this result, it was turned out that all subjects feel that proposed interface was intuitive, or to control at their direction. Therefore it was confirmed that human body motion interface has a possibility to be used for an interface of electric wheelchair.

  14. Exceptional evolutionary divergence of human muscle and brain metabolomes parallels human cognitive and physical uniqueness

    DEFF Research Database (Denmark)

    Bozek, Katarzyna; Wei, Yuning; Yan, Zheng

    2014-01-01

    Metabolite concentrations reflect the physiological states of tissues and cells. However, the role of metabolic changes in species evolution is currently unknown. Here, we present a study of metabolome evolution conducted in three brain regions and two non-neural tissues from humans, chimpanzees......, macaque monkeys, and mice based on over 10,000 hydrophilic compounds. While chimpanzee, macaque, and mouse metabolomes diverge following the genetic distances among species, we detect remarkable acceleration of metabolome evolution in human prefrontal cortex and skeletal muscle affecting neural and energy...... metabolism pathways. These metabolic changes could not be attributed to environmental conditions and were confirmed against the expression of their corresponding enzymes. We further conducted muscle strength tests in humans, chimpanzees, and macaques. The results suggest that, while humans are characterized...

  15. Estimation of Human Body Shape and Posture Under Clothing

    OpenAIRE

    Wuhrer, Stefanie; Pishchulin, Leonid; Brunton, Alan; Shu, Chang; Lang, Jochen

    2013-01-01

    Estimating the body shape and posture of a dressed human subject in motion represented as a sequence of (possibly incomplete) 3D meshes is important for virtual change rooms and security. To solve this problem, statistical shape spaces encoding human body shape and posture variations are commonly used to constrain the search space for the shape estimate. In this work, we propose a novel method that uses a posture-invariant shape space to model body shape variation combined with a skeleton-bas...

  16. Response to Jakobsson on Human Body Shields

    Directory of Open Access Journals (Sweden)

    Walter E. Block

    2010-10-01

    Full Text Available A grabs B and uses him as a body shield. That is, A hides behind B (A renders B helpless to resist his grasp, and from that vantage point, shoots at C. According to libertarian theory, may B shoot at C, or, is it proper that C pull the trigger at B? In the view of Rothbard (1984, the former is correct: B is entitled to gun down C. In my (Block, forthcoming view, this is incorrect. Rather, it would be lawful to C to properly kill B. (Both Rothbard and I assume that neither B nor C can end A’s reign of terror. Jakobsson (2010 supports the Rothbardian position. The present paper is at an attempt of mine to refute Jakobsson, and, thus, also, Rothbard (1984, once again.

  17. Influence of mechanical stimulation on human dermal fibroblasts derived from different body sites.

    Science.gov (United States)

    Kuang, Ruixia; Wang, Zhiguo; Xu, Quanchen; Liu, Su; Zhang, Weidong

    2015-01-01

    Mechanical stimulation is highly associated with pathogenesis of human hypertrophic scar. Although much work has focused on the influence of mechanical stress on fibroblast populations from various tissues and organs in the human body, their effects on cultured dermal fibroblasts by the area of the body have not been as well studied. In this study, cultures of skin fibroblasts from two different body sites were subjected to cyclic mechanical stimulation with a 10% stretching amplitude at a frequency of 0.1 Hz for 24, 36 and 48 hours, respectively, and thereafter harvested for experimental assays. Fibroblasts from scapular upper back skin, subjected to mechanical loads for 36 and 48 hours, respectively, were observed to proliferate at a higher rate and reach confluent more rapidly during in vitro culturing, had higher expression levels of mRNA and protein production of integrin β1, p130Cas and TGF β1 versus those from medial side of upper arm. These data indicate that skin fibroblasts, with regard to originated body sites studied in the experiments, display a diversity of mechanotransduction properties and biochemical reactions in response to applied mechanical stress, which contributes to the increased susceptibility to hypertrophic scars formation at certain areas of human body characterized by higher skin and muscle tension.

  18. Expression of nitric oxide synthase and guanylate cyclase in the human ciliary body and trabecular meshwork

    Institute of Scientific and Technical Information of China (English)

    WU Ren-yi; MA Ning

    2012-01-01

    Background The role played by the nitric oxide (NO) signaling pathway in the aqueous humor dynamics is still unclear.This study was designed to investigate the expression and distribution of NO synthase (NOS) isoforms and guanylate cyclase (GC) in human ciliary body,trabecular meshwork and the Schlemm's canal.Methods Twelve eyes after corneal transplantation were used.Expression of three NOS isoforms (i.e.neuronal NOS (nNOS),inducible NOS (iNOS) and endothelial NOS (eNOS)) and GC were assessed in 10 eyes by immunohistochemical staining using monoclonal or polyclonal antibody of NOS and GC.Ciliary bodies were dissected free and the total proteins were extracted.Western blotting was performed to confirm the protein expression of 3 NOS isoforms and GC.Results Expression of 3 NOS isoforms and GC were observed in the ciliary epithelium,ciliary muscle,trabecular meshwork and the endothelium of the Schlemm's canal.Immunoreactivity of nNOS was detected mainly along the apical cytoplasmic junction of the non-pigmented epithelium (NPE) and pigmented epithelial (PE) cells.Protein expressions of 3 NOS isoforms and GC were confirmed in isolated human ciliary body by Western blotting.Conclusions The expression of NOS isoforms and GC in human ciliary body suggest the possible involvement of NO and cyclic guanosine monophosphate (cyclic GMP,cGMP) signaling pathway in the ciliary body,and may play a role in both processes of aqueous humor formation and drainage.

  19. Load and failure behavior of human muscle samples in the context of proximal femur replacement

    OpenAIRE

    Schleifenbaum, Stefan; Schmidt, Michael; Möbius, Robert; Wolfskämpf, Thomas; Schröder, Christian; Grunert, Ronny; Hammer, Niels; Prietzel, Torsten

    2016-01-01

    Background: To ensure adequate function after orthopedic tumor reconstruction, it is important to reattach the remaining soft tissue to the implant. This study aimed at obtaining mechanical properties of textile muscle-implant and muscle-bone connections in a preliminary test. Methods: Two groups of soft-tissue attachment were mechanically tested and compared: Native bone-muscle samples obtained from human femora and muscles attached to a prosthetic implant by means of Trevira® attachment tu...

  20. Molecular basis of the myogenic profile of aged human skeletal muscle satellite cells during differentiation

    OpenAIRE

    Pietrangelo, Tiziana; Puglielli, Cristina; Mancinelli, Rosa; Beccafico, Sara; Fanò, Giorgio; Fulle, Stefania

    2009-01-01

    Abstract Sarcopenia is the age-related loss of muscle mass, strength and function. Human muscle proteins are synthesized at a slower rate in the elderly than in young adults, leading to atrophy and muscle mass loss with a decline in the functional capability. Additionally, aging is accompanied by a decrease in the ability of muscle tissue to regenerate following injury or overuse due to the impairment of intervening satellite cells, in which we previously reported oxidative damage ...

  1. Aging affects the transcriptional regulation of human skeletal muscle disuse atrophy

    DEFF Research Database (Denmark)

    Suetta, Charlotte; Frandsen, Ulrik; Nielsen, Line;

    2012-01-01

    Important insights concerning the molecular basis of skeletal muscle disuse-atrophy and aging related muscle loss have been obtained in cell culture and animal models, but these regulatory signaling pathways have not previously been studied in aging human muscle. In the present study, muscle...... atrophy was induced by immobilization in healthy old and young individuals to study the time-course and transcriptional factors underlying human skeletal muscle atrophy. The results reveal that irrespectively of age, mRNA expression levels of MuRF-1 and Atrogin-1 increased in the very initial phase (2......-4 days) of human disuse-muscle atrophy along with a marked reduction in PGC-1a and PGC-1ß (1-4 days) and a ~10% decrease in myofiber size (4 days). Further, an age-specific decrease in Akt and S6 phosphorylation was observed in young muscle within the first days (1-4 days) of immobilization. In contrast...

  2. Muscle Patterning in Mouse and Human Abdominal Wall Development and Omphalocele Specimens of Humans

    OpenAIRE

    Nichol, Peter F.; Corliss, Robert F.; Yamada, Shigehito; SHIOTA, KOHEI; Saijoh, Yukio

    2012-01-01

    Human omphalocele is a congenital defect of the abdominal wall in which the secondary abdominal wall structures (muscle and connective tissue) in an area centered around the umbilicus are replaced by a translucent membranous layer of tissue. Histological examination of omphalocele development and moreover the staging of normal human abdominal wall development has never been described. We hypothesized that omphalocele is the result of an arrest in the secondary abdominal wall development and p...

  3. Exosomes from differentiating human skeletal muscle cells trigger myogenesis of stem cells and provide biochemical cues for skeletal muscle regeneration.

    Science.gov (United States)

    Choi, Ji Suk; Yoon, Hwa In; Lee, Kyoung Soo; Choi, Young Chan; Yang, Seong Hyun; Kim, In-San; Cho, Yong Woo

    2016-01-28

    Exosomes released from skeletal muscle cells play important roles in myogenesis and muscle development via the transfer of specific signal molecules. In this study, we investigated whether exosomes secreted during myotube differentiation from human skeletal myoblasts (HSkM) could induce a cellular response from human adipose-derived stem cells (HASCs) and enhance muscle regeneration in a muscle laceration mouse model. The exosomes contained various signal molecules including myogenic growth factors related to muscle development, such as insulin-like growth factors (IGFs), hepatocyte growth factor (HGF), fibroblast growth factor-2 (FGF2), and platelet-derived growth factor-AA (PDGF-AA). Interestingly, exosome-treated HASCs fused with neighboring cells at early time points and exhibited a myotube-like phenotype with increased expression of myogenic proteins (myosin heavy chain and desmin). On day 21, mRNAs of terminal myogenic genes were also up-regulated in exosome-treated HASCs. Moreover, in vivo studies demonstrated that exosomes from differentiating HSkM reduced the fibrotic area and increased the number of regenerated myofibers in the injury site, resulting in significant improvement of skeletal muscle regeneration. Our findings suggest that exosomes act as a biochemical cue directing stem cell differentiation and provide a cell-free therapeutic approach for muscle regeneration.

  4. Attenuation of skeletal muscle wasting with recombinant human growth hormone secreted from a tissue-engineered bioartificial muscle

    Science.gov (United States)

    Vandenburgh, H.; Del Tatto, M.; Shansky, J.; Goldstein, L.; Russell, K.; Genes, N.; Chromiak, J.; Yamada, S.

    1998-01-01

    Skeletal muscle wasting is a significant problem in elderly and debilitated patients. Growth hormone (GH) is an anabolic growth factor for skeletal muscle but is difficult to deliver in a therapeutic manner by injection owing to its in vivo instability. A novel method is presented for the sustained secretion of recombinant human GH (rhGH) from genetically modified skeletal muscle implants, which reduces host muscle wasting. Proliferating murine C2C12 skeletal myoblasts stably transduced with the rhGH gene were tissue engineered in vitro into bioartificial muscles (C2-BAMs) containing organized postmitotic myofibers secreting 3-5 microg of rhGH/day in vitro. When implanted subcutaneously into syngeneic mice, C2-BAMs delivered a sustained physiologic dose of 2.5 to 11.3 ng of rhGH per milliliter of serum. rhGH synthesized and secreted by the myofibers was in the 22-kDa monomeric form and was biologically active, based on downregulation of a GH-sensitive protein synthesized in the liver. Skeletal muscle disuse atrophy was induced in mice by hindlimb unloading, causing the fast plantaris and slow soleus muscles to atrophy by 21 to 35% ( muscle-wasting disorders.

  5. Nuclear fusion-independent smooth muscle differentiation of human adipose-derived stem cells induced by a smooth muscle environment.

    Science.gov (United States)

    Zhang, Rong; Jack, Gregory S; Rao, Nagesh; Zuk, Patricia; Ignarro, Louis J; Wu, Benjamin; Rodríguez, Larissa V

    2012-03-01

    Human adipose-derived stem cells hASC have been isolated and were shown to have multilineage differentiation capacity. Although both plasticity and cell fusion have been suggested as mechanisms for cell differentiation in vivo, the effect of the local in vivo environment on the differentiation of adipose-derived stem cells has not been evaluated. We previously reported the in vitro capacity of smooth muscle differentiation of these cells. In this study, we evaluate the effect of an in vivo smooth muscle environment in the differentiation of hASC. We studied this by two experimental designs: (a) in vivo evaluation of smooth muscle differentiation of hASC injected into a smooth muscle environment and (b) in vitro evaluation of smooth muscle differentiation capacity of hASC exposed to bladder smooth muscle cells. Our results indicate a time-dependent differentiation of hASC into mature smooth muscle cells when these cells are injected into the smooth musculature of the urinary bladder. Similar findings were seen when the cells were cocultured in vitro with primary bladder smooth muscle cells. Chromosomal analysis demonstrated that microenvironment cues rather than nuclear fusion are responsible for this differentiation. We conclude that cell plasticity is present in hASCs, and their differentiation is accomplished in the absence of nuclear fusion.

  6. Attenuation of skeletal muscle wasting with recombinant human growth hormone secreted from a tissue-engineered bioartificial muscle

    Science.gov (United States)

    Vandenburgh, H.; Del Tatto, M.; Shansky, J.; Goldstein, L.; Russell, K.; Genes, N.; Chromiak, J.; Yamada, S.

    1998-01-01

    Skeletal muscle wasting is a significant problem in elderly and debilitated patients. Growth hormone (GH) is an anabolic growth factor for skeletal muscle but is difficult to deliver in a therapeutic manner by injection owing to its in vivo instability. A novel method is presented for the sustained secretion of recombinant human GH (rhGH) from genetically modified skeletal muscle implants, which reduces host muscle wasting. Proliferating murine C2C12 skeletal myoblasts stably transduced with the rhGH gene were tissue engineered in vitro into bioartificial muscles (C2-BAMs) containing organized postmitotic myofibers secreting 3-5 microg of rhGH/day in vitro. When implanted subcutaneously into syngeneic mice, C2-BAMs delivered a sustained physiologic dose of 2.5 to 11.3 ng of rhGH per milliliter of serum. rhGH synthesized and secreted by the myofibers was in the 22-kDa monomeric form and was biologically active, based on downregulation of a GH-sensitive protein synthesized in the liver. Skeletal muscle disuse atrophy was induced in mice by hindlimb unloading, causing the fast plantaris and slow soleus muscles to atrophy by 21 to 35% ( muscle-wasting disorders.

  7. Beyond body size: muscle biochemistry and body shape explain ontogenetic variation of anti-predatory behaviour in the lizard Salvator merianae.

    Science.gov (United States)

    de Barros, Fábio Cury; de Carvalho, José Eduardo; Abe, Augusto Shinya; Kohlsdorf, Tiana

    2016-06-01

    Anti-predatory behaviour evolves under the strong action of natural selection because the success of individuals avoiding predation essentially defines their fitness. Choice of anti-predatory strategies is defined by prey characteristics as well as environmental temperature. An additional dimension often relegated in this multilevel equation is the ontogenetic component. In the tegu Salvator merianae, adults run away from predators at high temperatures but prefer fighting when it is cold, whereas juveniles exhibit the same flight strategy within a wide thermal range. Here, we integrate physiology and morphology to understand ontogenetic variation in the temperature-dependent shift of anti-predatory behaviour in these lizards. We compiled data for body shape and size, and quantified enzyme activity in hindlimb and head muscles, testing the hypothesis that morphophysiological models explain ontogenetic variation in behavioural associations. Our prediction is that juveniles exhibit body shape and muscle biochemistry that enhance flight strategies. We identified biochemical differences between muscles mainly in the LDH:CS ratio, whereby hindlimb muscles were more glycolytic than the jaw musculature. Juveniles, which often use evasive strategies to avoid predation, have more glycolytic hindlimb muscles and are much smaller when compared with adults 1-2 years old. Ontogenetic differences in body shape were identified but marginally contributed to behavioural variation between juvenile and adult tegus, and variation in anti-predatory behaviour in these lizards resides mainly in associations between body size and muscle biochemistry. Our results are discussed in the ecological context of predator avoidance by individuals differing in body size living at temperature-variable environments, where restrictions imposed by the cold could be compensated by specific phenotypes. © 2016. Published by The Company of Biologists Ltd.

  8. DEVELOPMENT OF 2D HUMAN BODY MODELING USING THINNING ALGORITHM

    Directory of Open Access Journals (Sweden)

    K. Srinivasan

    2010-11-01

    Full Text Available Monitoring the behavior and activities of people in Video surveillance has gained more applications in Computer vision. This paper proposes a new approach to model the human body in 2D view for the activity analysis using Thinning algorithm. The first step of this work is Background subtraction which is achieved by the frame differencing algorithm. Thinning algorithm has been used to find the skeleton of the human body. After thinning, the thirteen feature points like terminating points, intersecting points, shoulder, elbow, and knee points have been extracted. Here, this research work attempts to represent the body model in three different ways such as Stick figure model, Patch model and Rectangle body model. The activities of humans have been analyzed with the help of 2D model for the pre-defined poses from the monocular video data. Finally, the time consumption and efficiency of our proposed algorithm have been evaluated.

  9. Categorical discrimination of human body parts by magnetoencephalography.

    Science.gov (United States)

    Nakamura, Misaki; Yanagisawa, Takufumi; Okamura, Yumiko; Fukuma, Ryohei; Hirata, Masayuki; Araki, Toshihiko; Kamitani, Yukiyasu; Yorifuji, Shiro

    2015-01-01

    Humans recognize body parts in categories. Previous studies have shown that responses in the fusiform body area (FBA) and extrastriate body area (EBA) are evoked by the perception of the human body, when presented either as whole or as isolated parts. These responses occur approximately 190 ms after body images are visualized. The extent to which body-sensitive responses show specificity for different body part categories remains to be largely clarified. We used a decoding method to quantify neural responses associated with the perception of different categories of body parts. Nine subjects underwent measurements of their brain activities by magnetoencephalography (MEG) while viewing 14 images of feet, hands, mouths, and objects. We decoded categories of the presented images from the MEG signals using a support vector machine (SVM) and calculated their accuracy by 10-fold cross-validation. For each subject, a response that appeared to be a body-sensitive response was observed and the MEG signals corresponding to the three types of body categories were classified based on the signals in the occipitotemporal cortex. The accuracy in decoding body-part categories (with a peak at approximately 48%) was above chance (33.3%) and significantly higher than that for random categories. According to the time course and location, the responses are suggested to be body-sensitive and to include information regarding the body-part category. Finally, this non-invasive method can decode category information of a visual object with high temporal and spatial resolution and this result may have a significant impact in the field of brain-machine interface research.

  10. Representational Similarity of Body Parts in Human Occipitotemporal Cortex.

    Science.gov (United States)

    Bracci, Stefania; Caramazza, Alfonso; Peelen, Marius V

    2015-09-23

    Regions in human lateral and ventral occipitotemporal cortices (OTC) respond selectively to pictures of the human body and its parts. What are the organizational principles underlying body part responses in these regions? Here we used representational similarity analysis (RSA) of fMRI data to test multiple possible organizational principles: shape similarity, physical proximity, cortical homunculus proximity, and semantic similarity. Participants viewed pictures of whole persons, chairs, and eight body parts (hands, arms, legs, feet, chests, waists, upper faces, and lower faces). The similarity of multivoxel activity patterns for all body part pairs was established in whole person-selective OTC regions. The resulting neural similarity matrices were then compared with similarity matrices capturing the hypothesized organizational principles. Results showed that the semantic similarity model best captured the neural similarity of body parts in lateral and ventral OTC, which followed an organization in three clusters: (1) body parts used as action effectors (hands, feet, arms, and legs), (2) noneffector body parts (chests and waists), and (3) face parts (upper and lower faces). Whole-brain RSA revealed, in addition to OTC, regions in parietal and frontal cortex in which neural similarity was related to semantic similarity. In contrast, neural similarity in occipital cortex was best predicted by shape similarity models. We suggest that the semantic organization of body parts in high-level visual cortex relates to the different functions associated with the three body part clusters, reflecting the unique processing and connectivity demands associated with the different types of information (e.g., action, social) different body parts (e.g., limbs, faces) convey. Significance statement: While the organization of body part representations in motor and somatosensory cortices has been well characterized, the principles underlying body part representations in visual cortex

  11. Relationship between alertness, performance, and body temperature in humans

    Science.gov (United States)

    Wright, Kenneth P Jr; Hull, Joseph T.; Czeisler, Charles A.

    2002-01-01

    Body temperature has been reported to influence human performance. Performance is reported to be better when body temperature is high/near its circadian peak and worse when body temperature is low/near its circadian minimum. We assessed whether this relationship between performance and body temperature reflects the regulation of both the internal biological timekeeping system and/or the influence of body temperature on performance independent of circadian phase. Fourteen subjects participated in a forced desynchrony protocol allowing assessment of the relationship between body temperature and performance while controlling for circadian phase and hours awake. Most neurobehavioral measures varied as a function of internal biological time and duration of wakefulness. A number of performance measures were better when body temperature was elevated, including working memory, subjective alertness, visual attention, and the slowest 10% of reaction times. These findings demonstrate that an increased body temperature, associated with and independent of internal biological time, is correlated with improved performance and alertness. These results support the hypothesis that body temperature modulates neurobehavioral function in humans.

  12. Molecular networks of human muscle adaptation to exercise and age.

    Directory of Open Access Journals (Sweden)

    Bethan E Phillips

    2013-03-01

    Full Text Available Physical activity and molecular ageing presumably interact to precipitate musculoskeletal decline in humans with age. Herein, we have delineated molecular networks for these two major components of sarcopenic risk using multiple independent clinical cohorts. We generated genome-wide transcript profiles from individuals (n = 44 who then undertook 20 weeks of supervised resistance-exercise training (RET. Expectedly, our subjects exhibited a marked range of hypertrophic responses (3% to +28%, and when applying Ingenuity Pathway Analysis (IPA up-stream analysis to ~580 genes that co-varied with gain in lean mass, we identified rapamycin (mTOR signaling associating with growth (P = 1.4 × 10(-30. Paradoxically, those displaying most hypertrophy exhibited an inhibited mTOR activation signature, including the striking down-regulation of 70 rRNAs. Differential analysis found networks mimicking developmental processes (activated all-trans-retinoic acid (ATRA, Z-score = 4.5; P = 6 × 10(-13 and inhibited aryl-hydrocarbon receptor signaling (AhR, Z-score = -2.3; P = 3 × 10(-7 with RET. Intriguingly, as ATRA and AhR gene-sets were also a feature of endurance exercise training (EET, they appear to represent "generic" physical activity responsive gene-networks. For age, we found that differential gene-expression methods do not produce consistent molecular differences between young versus old individuals. Instead, utilizing two independent cohorts (n = 45 and n = 52, with a continuum of subject ages (18-78 y, the first reproducible set of age-related transcripts in human muscle was identified. This analysis identified ~500 genes highly enriched in post-transcriptional processes (P = 1 × 10(-6 and with negligible links to the aforementioned generic exercise regulated gene-sets and some overlap with ribosomal genes. The RNA signatures from multiple compounds all targeting serotonin, DNA topoisomerase antagonism, and RXR activation were significantly related to

  13. [How does music affect the human body?].

    Science.gov (United States)

    Myskja, A; Lindbaek, M

    2000-04-10

    Music therapy has developed its practice and research approaches within a qualitative framework more related to humanistic traditions than to medical science. Music medicine has therefore developed as a separate discipline, endeavouring to incorporate the legitimate therapeutic use of music within a medical framework. This paper argues that more extensive communication and collaboration between the methods developed within the music therapy community, and research based on medical science, could lead to a better understanding of the place of music as a therapeutic tool, both as regards its efficacy and its limits. Research has shown that music may influence central physiological variables like blood pressure, heart rate, respiration, EEG measurements, body temperature and galvanic skin response. Music influences immune and endocrine function. The existing research literature shows growing knowledge of how music can ameliorate pain, anxiety, nausea, fatigue and depression. There is less research done on how music, and what type of music, is utilized and administered specifically for optimum effect in specific clinical situations.

  14. Size variation in small-bodied humans from palau, micronesia.

    Directory of Open Access Journals (Sweden)

    Andrew Gallagher

    Full Text Available BACKGROUND: Recent discoveries on Palau are claimed to represent the remains of small-bodied humans that may display evidence insular size reduction. This claim has yet to be statistically validated METHODOLOGY/PRINCIPAL FINDINGS: Published postcranial specimens (n = 16 from Palau were assessed relative to recent small-bodied comparative samples. Resampling statistical approaches were employed to test specific hypotheses relating to body size in the Palau sample. Results confirm that the Palau postcranial sample is indisputably small-bodied. CONCLUSIONS/SIGNIFICANCE: A single, homogenous body size morph is represented in early prehistoric postcrania from Palau. Small body size in early Palauans is an ancestral characteristic and was likely not a consequence of in-situ size reduction. Specimens from Palau have little bearing upon hypothesised insular size reduction in the ancestral lineage of Homo floresiensis.

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

    Directory of Open Access Journals (Sweden)

    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.

  16. RUNNING 338 KILOMETRES WITHIN FIVE DAYS HAS NO EFFECT ON BODY MASS AND BODY FAT BUT REDUCES SKELETAL MUSCLE MASS - THE ISARRUN 2006

    Directory of Open Access Journals (Sweden)

    Beat Knechtle

    2007-12-01

    Full Text Available We investigated the change of body composition in ultra- endurance runners during a multi-stage ultra-endurance run, the Isarrun 2006 in Bavaria, Germany, where athletes had to run 338 km within 5 days. Body mass, skin fold thicknesses and circumferences of extremities were measured in 21 well-experienced extreme endurance male runners (mean ± SD, 41.5 ± 6.9 years, 72.6 ± 6.4 kg, 178 ± 5 cm, BMI 23.0 ± 2.0 kg/m2, who finished mainly within the first half of the ranking, in order to calculate skeletal muscle mass and body fat mass to prove changes after the race. Body mass and calculated fat mass did not change significantly (p>0.05, but, calculated skeletal muscle mass decreased significantly (p<0.05 by 0.63 ± 0.79 kg by the end of the race. The most apparent decline (p<0.01 of the calculated skeletal muscle mass was during the first stage, and no changes were observed during the last 4 stages. We conclude, that a multi- stage ultra-endurance run over 338 km within 5 days leads to no changes of body mass or body fat mass, but a statistically significant decrease of skeletal muscle mass of 0.63 ± 0.79 kg by the end of the race in well-trained and well-experienced ultra-endurance runners. The change of skeletal muscle mass has to be evaluated in further studies at ultra-endurance races with suitable methods to detect changes in hydration status and water metabolism

  17. Natural User Interface Sensors for Human Body Measurement

    Science.gov (United States)

    Boehm, J.

    2012-08-01

    The recent push for natural user interfaces (NUI) in the entertainment and gaming industry has ushered in a new era of low cost three-dimensional sensors. While the basic idea of using a three-dimensional sensor for human gesture recognition dates some years back it is not until recently that such sensors became available on the mass market. The current market leader is PrimeSense who provide their technology for the Microsoft Xbox Kinect. Since these sensors are developed to detect and observe human users they should be ideally suited to measure the human body. We describe the technology of a line of NUI sensors and assess their performance in terms of repeatability and accuracy. We demonstrate the implementation of a prototype scanner integrating several NUI sensors to achieve full body coverage. We present the results of the obtained surface model of a human body.

  18. Trains of electrical stimulation of the trapezius muscles redistribute the frequencies of body oscillations during stance.

    Science.gov (United States)

    Nhouvannasak, V; Clément, S; Manto, M

    2015-09-01

    We investigated the postural effects of trains of electrical stimulation (TES) applied unilaterally or bilaterally on the trapezius muscle in 20 healthy subjects (mean age: 23.1 ± 1.33 years; F/M: 8/12). The anterior-posterior (AP) displacements (AP axis), medio-lateral displacements (ML axis) and total travelled distances (TTW) of the centre of pressure (COP) remained unchanged with TES. However, detailed spectral analysis of COP oscillations revealed a marked decrease of the magnitudes of peak power spectral density (peak PSD) following application of TES. Peak PSD was highly correlated with the intensity of stimulation (P 0.30) and the integrals of the sub-band 8-10 Hz were significantly increased (P < 0.001). The ratios of the integrals of sub-bands 8-10 Hz/0-3 Hz were markedly enhanced with bilateral TES (P < 0.001). For the ML axis, the effects were striking (P < 0.001) for the sub-bands 0-0.4, 0.4-1.5 and 8-10 Hz. For both the AP and ML axes, a significant inverse linear relationship was found between the intensity of TES and the average speed of COP. We show that TES applied over the trapezius muscles exerts significant and so far unrecognised effects upon oscillations of the COP, decreasing low-frequency oscillations and enhancing high-frequency oscillations. Our data unravel a novel property of the trapezius muscles upon postural control. We suggest that this muscle plays a role of a distributor of low-frequency versus high-frequency sub-bands of frequency during stance. Previous studies have shown that patients with supra-tentorial stroke show an increased peak PSD in low frequencies of body oscillations. Therefore, our findings provide a rationale to assess neurostimulation of the trapezius muscle in the rehabilitation of postural deficits in supra-tentorial stroke.

  19. Whole-Body Vibration and the Prevention and Treatment of Delayed-Onset Muscle Soreness

    Science.gov (United States)

    Aminian-Far, Atefeh; Hadian, Mohammad-Reza; Olyaei, Gholamreza; Talebian, Saeed; Bakhtiary, Amir Hoshang

    2011-01-01

    Abstract Context: Numerous recovery strategies have been used in an attempt to minimize the symptoms of delayed-onset muscle soreness (DOMS). Whole-body vibration (WBV) has been suggested as a viable warm-up for athletes. However, scientific evidence to support the protective effects of WBV training (WBVT) on muscle damage is lacking. Objective: To investigate the acute effect of WBVT applied before eccentric exercise in the prevention of DOMS. Design: Randomized controlled trial. Setting: University laboratory. Patients or Other Participants: A total of 32 healthy, untrained volunteers were randomly assigned to either the WBVT (n  =  15) or control (n  =  17) group. Intervention(s): Volunteers performed 6 sets of 10 maximal isokinetic (60°/s) eccentric contractions of the dominant-limb knee extensors on a dynamometer. In the WBVT group, the training was applied using a vibratory platform (35 Hz, 5 mm peak to peak) with 100° of knee flexion for 60 seconds before eccentric exercise. No vibration was applied in the control group. Main Outcome Measure(s): Muscle soreness, thigh circumference, and pressure pain threshold were recorded at baseline and at 1, 2, 3, 4, 7, and 14 days postexercise. Maximal voluntary isometric and isokinetic knee extensor strength were assessed at baseline, immediately after exercise, and at 1, 2, 7, and 14 days postexercise. Serum creatine kinase was measured at baseline and at 1, 2, and 7 days postexercise. Results: The WBVT group showed a reduction in DOMS symptoms in the form of less maximal isometric and isokinetic voluntary strength loss, lower creatine kinase levels, and less pressure pain threshold and muscle soreness (P < .05) compared with the control group. However, no effect on thigh circumference was evident (P < .05). Conclusions: Administered before eccentric exercise, WBVT may reduce DOMS via muscle function improvement. Further investigation should be undertaken to ascertain the effectiveness of WBVT in

  20. Body mass estimates of hominin fossils and the evolution of human body size.

    Science.gov (United States)

    Grabowski, Mark; Hatala, Kevin G; Jungers, William L; Richmond, Brian G

    2015-08-01

    Body size directly influences an animal's place in the natural world, including its energy requirements, home range size, relative brain size, locomotion, diet, life history, and behavior. Thus, an understanding of the biology of extinct organisms, including species in our own lineage, requires accurate estimates of body size. Since the last major review of hominin body size based on postcranial morphology over 20 years ago, new fossils have been discovered, species attributions have been clarified, and methods improved. Here, we present the most comprehensive and thoroughly vetted set of individual fossil hominin body mass predictions to date, and estimation equations based on a large (n = 220) sample of modern humans of known body masses. We also present species averages based exclusively on fossils with reliable taxonomic attributions, estimates of species averages by sex, and a metric for levels of sexual dimorphism. Finally, we identify individual traits that appear to be the most reliable for mass estimation for each fossil species, for use when only one measurement is available for a fossil. Our results show that many early hominins were generally smaller-bodied than previously thought, an outcome likely due to larger estimates in previous studies resulting from the use of large-bodied modern human reference samples. Current evidence indicates that modern human-like large size first appeared by at least 3-3.5 Ma in some Australopithecus afarensis individuals. Our results challenge an evolutionary model arguing that body size increased from Australopithecus to early Homo. Instead, we show that there is no reliable evidence that the body size of non-erectus early Homo differed from that of australopiths, and confirm that Homo erectus evolved larger average body size than earlier hominins. Copyright © 2015 Elsevier Ltd. All rights reserved.

  1. Validation of Shoulder Response of Human Body Finite-Element Model (GHBMC) Under Whole Body Lateral Impact Condition.

    Science.gov (United States)

    Park, Gwansik; Kim, Taewung; Panzer, Matthew B; Crandall, Jeff R

    2016-08-01

    In previous shoulder impact studies, the 50th-percentile male GHBMC human body finite-element model was shown to have good biofidelity regarding impact force, but under-predicted shoulder deflection by 80% compared to those observed in the experiment. The goal of this study was to validate the response of the GHBMC M50 model by focusing on three-dimensional shoulder kinematics under a whole-body lateral impact condition. Five modifications, focused on material properties and modeling techniques, were introduced into the model and a supplementary sensitivity analysis was done to determine the influence of each modification to the biomechanical response of the body. The modified model predicted substantially improved shoulder response and peak shoulder deflection within 10% of the observed experimental data, and showed good correlation in the scapula kinematics on sagittal and transverse planes. The improvement in the biofidelity of the shoulder region was mainly due to the modifications of material properties of muscle, the acromioclavicular joint, and the attachment region between the pectoralis major and ribs. Predictions of rib fracture and chest deflection were also improved because of these modifications.

  2. Human skeletal muscle fatty acid and glycerol metabolism during rest, exercise and recovery

    DEFF Research Database (Denmark)

    Van Hall, Gerrit; Sacchetti, M; Rådegran, G

    2002-01-01

    This study was conducted to investigate skeletal muscle fatty acid (FA) and glycerol kinetics and to determine the contribution of skeletal muscle to whole body FA and glycerol turnover during rest, 2 h of one-leg knee-extensor exercise at 65 % of maximal leg power output, and 3 h of recovery....... To this aim, the leg femoral arterial-venous difference technique was used in combination with a continuous infusion of [U-(13)C]palmitate and [(2)H(5)]glycerol in five post-absorptive healthy volunteers (22 +/- 3 years). The influence of contamination from non-skeletal muscle tissues, skin and subcutaneous...... glycerol uptake was observed, which was substantially higher during exercise. Total body skeletal muscle FA and glycerol uptake/release was estimated to account for 18-25 % of whole body R(d) or R(a). In conclusion: (1) skeletal muscle FA and glycerol metabolism, using the leg arterial-venous difference...

  3. Effect of repeated forearm muscle cooling on the adaptation of skeletal muscle metabolism in humans

    Science.gov (United States)

    Wakabayashi, Hitoshi; Nishimura, Takayuki; Wijayanto, Titis; Watanuki, Shigeki; Tochihara, Yutaka

    2017-01-01

    This study aimed to investigate the effect of repeated cooling of forearm muscle on adaptation in skeletal muscle metabolism. It is hypothesized that repeated decreases of muscle temperature would increase the oxygen consumption in hypothermic skeletal muscle. Sixteen healthy males participated in this study. Their right forearm muscles were locally cooled to 25 °C by cooling pads attached to the skin. This local cooling was repeated eight times on separate days for eight participants (experimental group), whereas eight controls received no cold exposure. To evaluate adaptation in skeletal muscle metabolism, a local cooling test was conducted before and after the repeated cooling period. Change in oxy-hemoglobin content in the flexor digitorum at rest and during a 25-s isometric handgrip (10% maximal voluntary construction) was measured using near-infrared spectroscopy at every 2 °C reduction in forearm muscle temperature. The arterial blood flow was occluded for 15 s by upper arm cuff inflation at rest and during the isometric handgrip. The oxygen consumption in the flexor digitorum muscle was evaluated by a slope of the oxy-hemoglobin change during the arterial occlusion. In the experimental group, resting oxygen consumption in skeletal muscle did not show any difference between pre- and post-intervention, whereas muscle oxygen consumption during the isometric handgrip was significantly higher in post-intervention than in pre-test from thermoneutral baseline to 31 °C muscle temperature (P < 0.05). This result indicated that repeated local muscle cooling might facilitate oxidative metabolism in the skeletal muscle. In summary, skeletal muscle metabolism during submaximal isometric handgrip was facilitated after repeated local muscle cooling.

  4. Effect of repeated forearm muscle cooling on the adaptation of skeletal muscle metabolism in humans

    Science.gov (United States)

    Wakabayashi, Hitoshi; Nishimura, Takayuki; Wijayanto, Titis; Watanuki, Shigeki; Tochihara, Yutaka

    2017-07-01

    This study aimed to investigate the effect of repeated cooling of forearm muscle on adaptation in skeletal muscle metabolism. It is hypothesized that repeated decreases of muscle temperature would increase the oxygen consumption in hypothermic skeletal muscle. Sixteen healthy males participated in this study. Their right forearm muscles were locally cooled to 25 °C by cooling pads attached to the skin. This local cooling was repeated eight times on separate days for eight participants (experimental group), whereas eight controls received no cold exposure. To evaluate adaptation in skeletal muscle metabolism, a local cooling test was conducted before and after the repeated cooling period. Change in oxy-hemoglobin content in the flexor digitorum at rest and during a 25-s isometric handgrip (10% maximal voluntary construction) was measured using near-infrared spectroscopy at every 2 °C reduction in forearm muscle temperature. The arterial blood flow was occluded for 15 s by upper arm cuff inflation at rest and during the isometric handgrip. The oxygen consumption in the flexor digitorum muscle was evaluated by a slope of the oxy-hemoglobin change during the arterial occlusion. In the experimental group, resting oxygen consumption in skeletal muscle did not show any difference between pre- and post-intervention, whereas muscle oxygen consumption during the isometric handgrip was significantly higher in post-intervention than in pre-test from thermoneutral baseline to 31 °C muscle temperature ( P muscle cooling might facilitate oxidative metabolism in the skeletal muscle. In summary, skeletal muscle metabolism during submaximal isometric handgrip was facilitated after repeated local muscle cooling.

  5. Skin Sensitive Difference of Human Body Sections under Clothing --Comparative Judging of Body Sections' Cold Sensitivity Sequence

    Institute of Scientific and Technical Information of China (English)

    LI Jun; WANG Yun-yi; WU Hai-yan

    2005-01-01

    Skin sensitive difference of human body sections under clothing is the theoretic foundation of thermal insulation clothing design. By a new psychological & physical researching method, the subjective psychological perception of human body sections affected by the same cold stimulus are studied, and with Thurstone comparative judgement the main human body sections' cold sensitivity sequences are obtained. Furthermore the physiological causes for skin sensitive difference of human body sections under clothing are suggested.

  6. Characterization of human carbonic anhydrase III from skeletal muscle.

    Science.gov (United States)

    Carter, N; Jeffery, S; Shiels, A; Edwards, Y; Tipler, T; Hopkinson, D A

    1979-10-01

    A third form of human carbonic anhydrase (CA III), found at high concentrations in skeletal muscle, has been purified and characterized. This isozyme shows relatively poor hydratase and esterase activities compared to the red cell isozymes, CA I and CA II, but is similar to these isozymes in subunit structure (monomer) and molecular size (28,000). CA III is liable to posttranslational modification by thiol group interaction. Monomeric secondary isozymes, sensitive to beta-mercaptoethanol, are found in both crude and purified material and can be generated in vitro by the addition of thiol reagents. Active dimeric isozymes, generated apparently by the formation of intermolecular disulfide bridges, also occur but account for only a small proportion of the total protein and appear only when the concentration of CA III is particularly high.

  7. Regional neuromuscular regulation within human rectus femoris muscle during gait.

    Science.gov (United States)

    Watanabe, Kohei; Kouzaki, Motoki; Moritani, Toshio

    2014-11-01

    The spatial distribution pattern of neuromuscular activation within the human rectus femoris (RF) muscle was investigated during gait by multi-channel surface electromyography (surface EMG). Eleven healthy men walked on a treadmill with three gait speeds (4, 5, and 6 km/h) and gradients (0°, 12.5°, and 25°). The spatial distribution of surface EMG was tested by central locus activation (CLA), which is calculated from 2-D multi-channel surface EMG with 46 surface electrodes. For all conditions, CLA was around the middle regions during the swing-to-stance transition and moved in a proximal direction during the stance phase and stance-to-swing transition (pphase significantly moved to proximal site with increasing gait speed (pphases, with increasing grade, CLA significantly moved distally (pgait cycle and is non-uniformly regulated longitudinally.

  8. Human eosinophil–airway smooth muscle cell interactions

    Directory of Open Access Journals (Sweden)

    J. Margaret Hughes

    2000-01-01

    Full Text Available Eosinophils are present throughout the airway wall of asthmatics. The nature of the interaction between human airway smooth muscle cells (ASMC and eosinophils was investigated in this study. We demonstrated, using light microscopy, that freshly isolated eosinophils from healthy donors rapidly attach to ASMC in vitro. Numbers of attached eosinophils were highest at 2 h, falling to 50% of maximum by 20 h. Eosinophil attachment at 2 h was reduced to 72% of control by anti-VCAM-1, and to 74% at 20 h by anti-ICAM-1. Pre-treatment of ASMC for 24 h with TNF-α, 10 nM, significantly increased eosinophil adhesion to 149 and 157% of control after 2 and 20 h. These results provide evidence that eosinophil interactions with ASMC involve VCAM-1 and ICAM-1 and are modulated by TNF-α.

  9. A Drosophila model of dominant inclusion body myopathy type 3 shows diminished myosin kinetics that reduce muscle power and yield myofibrillar defects.

    Science.gov (United States)

    Suggs, Jennifer A; Melkani, Girish C; Glasheen, Bernadette M; Detor, Mia M; Melkani, Anju; Marsan, Nathan P; Swank, Douglas M; Bernstein, Sanford I

    2017-06-01

    Individuals with inclusion body myopathy type 3 (IBM3) display congenital joint contractures with early-onset muscle weakness that becomes more severe in adulthood. The disease arises from an autosomal dominant point mutation causing an E706K substitution in myosin heavy chain type IIa. We have previously expressed the corresponding myosin mutation (E701K) in homozygous Drosophila indirect flight muscles and recapitulated the myofibrillar degeneration and inclusion bodies observed in the human disease. We have also found that purified E701K myosin has dramatically reduced actin-sliding velocity and ATPase levels. Since IBM3 is a dominant condition, we now examine the disease state in heterozygote Drosophila in order to gain a mechanistic understanding of E701K pathogenicity. Myosin ATPase activities in heterozygotes suggest that approximately equimolar levels of myosin accumulate from each allele. In vitro actin sliding velocity rates for myosin isolated from the heterozygotes were lower than the control, but higher than for the pure mutant isoform. Although sarcomeric ultrastructure was nearly wild type in young adults, mechanical analysis of skinned indirect flight muscle fibers revealed a 59% decrease in maximum oscillatory power generation and an approximately 20% reduction in the frequency at which maximum power was produced. Rate constant analyses suggest a decrease in the rate of myosin attachment to actin, with myosin spending decreased time in the strongly bound state. These mechanical alterations result in a one-third decrease in wing beat frequency and marginal flight ability. With aging, muscle ultrastructure and function progressively declined. Aged myofibrils showed Z-line streaming, consistent with the human heterozygote phenotype. Based upon the mechanical studies, we hypothesize that the mutation decreases the probability of the power stroke occurring and/or alters the degree of movement of the myosin lever arm, resulting in decreased in vitro

  10. A Drosophila model of dominant inclusion body myopathy type 3 shows diminished myosin kinetics that reduce muscle power and yield myofibrillar defects

    Directory of Open Access Journals (Sweden)

    Jennifer A. Suggs

    2017-06-01

    Full Text Available Individuals with inclusion body myopathy type 3 (IBM3 display congenital joint contractures with early-onset muscle weakness that becomes more severe in adulthood. The disease arises from an autosomal dominant point mutation causing an E706K substitution in myosin heavy chain type IIa. We have previously expressed the corresponding myosin mutation (E701K in homozygous Drosophila indirect flight muscles and recapitulated the myofibrillar degeneration and inclusion bodies observed in the human disease. We have also found that purified E701K myosin has dramatically reduced actin-sliding velocity and ATPase levels. Since IBM3 is a dominant condition, we now examine the disease state in heterozygote Drosophila in order to gain a mechanistic understanding of E701K pathogenicity. Myosin ATPase activities in heterozygotes suggest that approximately equimolar levels of myosin accumulate from each allele. In vitro actin sliding velocity rates for myosin isolated from the heterozygotes were lower than the control, but higher than for the pure mutant isoform. Although sarcomeric ultrastructure was nearly wild type in young adults, mechanical analysis of skinned indirect flight muscle fibers revealed a 59% decrease in maximum oscillatory power generation and an approximately 20% reduction in the frequency at which maximum power was produced. Rate constant analyses suggest a decrease in the rate of myosin attachment to actin, with myosin spending decreased time in the strongly bound state. These mechanical alterations result in a one-third decrease in wing beat frequency and marginal flight ability. With aging, muscle ultrastructure and function progressively declined. Aged myofibrils showed Z-line streaming, consistent with the human heterozygote phenotype. Based upon the mechanical studies, we hypothesize that the mutation decreases the probability of the power stroke occurring and/or alters the degree of movement of the myosin lever arm, resulting in

  11. Skeletal muscle contractile function and neuromuscular performance in Zmpste24 -/- mice, a murine model of human progeria.

    Science.gov (United States)

    Greising, Sarah M; Call, Jarrod A; Lund, Troy C; Blazar, Bruce R; Tolar, Jakub; Lowe, Dawn A

    2012-08-01

    Human progeroid syndromes and premature aging mouse models present as segmental, accelerated aging because some tissues and not others are affected. Skeletal muscle is detrimentally changed by normal aging but whether it is an affected tissue in progeria has not been resolved. We hypothesized that mice which mimic Hutchinson-Gilford progeria syndrome would exhibit age-related alterations of skeletal muscle. Zmpste24 (-/-) and Zmpste24 (+/+) littermates were assessed for skeletal muscle functions, histo-morphological characteristics, and ankle joint mechanics. Twenty-four-hour active time, ambulation, grip strength, and whole body tension were evaluated as markers of neuromuscular performance, each of which was at least 33% lower in Zmpste24 (-/-) mice compared with littermates (p normal. Ankle range of motion was 70% lower and plantar- and dorsiflexion passive torques were nearly 3-fold greater in Zmpste24 (-/-) than Zmpste24 (+/+) mice (p ≤ 0.01). The combined factors of muscle atrophy, collagen accumulation, and perturbed joint mechanics likely contributed to poor neuromuscular performance and selective muscle weakness displayed by Zmpste24 (-/-)mice. In summary, these characteristics are similar to those of aged mice indicating accelerated aging of skeletal muscle in progeria.

  12. The commerce of human body parts: an Eastern Orthodox response.

    Science.gov (United States)

    Reardon, P H

    2000-08-01

    The Orthodox Church teaches that the bodies of those in Christ are to be regarded as sanctified by the hearing of the Word and faithful participation in the Sacraments, most particularly the Holy Eucharist; because of the indwelling of the Holy Spirit the consecrated bodies of Christians do not belong to them but to Christ; with respect to the indwelling Holy Spirit there is no difference between the bodies of Christians before and after death; whether before or after death, the Christian body is also to receive the same veneration; and notwithstanding the physical corruptions that the body endures by reason of death, there remains a strict continuity between the body in which the Christian dies and the body in which the Christian will rise again. That is to say, it is the very same reality that is sown in corruption and will be raised in incorruption. Given such consideration, the notion of "selling" and integral part of a human being is simply outside the realm of rational comprehension. Indeed, it is profoundly repugnant to those Orthodox Christian sentiments that are formed and nourished by the Church's sacramental teaching and liturgical worship. One does not sell or purchase that which has been consecrated in those solemn ways that the Church consecrates the human body.

  13. Barriers in contribution of human mesenchymal stem cells to murine muscle regeneration.

    Science.gov (United States)

    de la Garza-Rodea, Anabel S; Boersma, Hester; Dambrot, Cheryl; de Vries, Antoine Af; van Bekkum, Dirk W; Knaän-Shanzer, Shoshan

    2015-05-20

    To study regeneration of damaged human and murine muscle implants and the contribution of added xenogeneic mesenchymal stem cells (MSCs). Minced human or mouse skeletal muscle tissues were implanted together with human or mouse MSCs subcutaneously on the back of non-obese diabetic/severe combined immunodeficient mice. The muscle tissues (both human and murine) were minced with scalpels into small pieces (< 1 mm(3)) and aliquoted in portions of 200 mm(3). These portions were either cryopreserved in 10% dimethylsulfoxide or freshly implanted. Syngeneic or xenogeneic MSCs were added to the minced muscles directly before implantation. Implants were collected at 7, 14, 30 or 45 d after transplantation and processed for (immuno)histological analysis. The progression of muscle regeneration was assessed using a standard histological staining (hematoxylin-phloxin-saffron). Antibodies recognizing Pax7 and von Willebrand factor were used to detect the presence of satellite cells and blood vessels, respectively. To enable detection of the bone marrow-derived MSCs or their derivatives we used MSCs previously transduced with lentiviral vectors expressing a cytoplasmic LacZ gene. X-gal staining of the fixed tissues was used to detect β-galactosidase-positive cells and myofibers. Myoregeneration in implants of fresh murine muscle was evident as early as day 7, and progressed with time to occupy 50% to 70% of the implants. Regeneration of fresh human muscle was slower. These observations of fresh muscle implants were in contrast to the regeneration of cryopreserved murine muscle that proceeded similarly to that of fresh tissue except for day 45 (P < 0.05). Cryopreserved human muscle showed minimal regeneration, suggesting that the freezing procedure was detrimental to human satellite cells. In fresh and cryopreserved mouse muscle supplemented with LacZ-tagged mouse MSCs, β-galactosidase-positive myofibers were identified early after grafting at the well-vascularized periphery of

  14. Effect of Vitamin D Supplement Consumption on Muscle Strength, Muscle Function and Body Composition in Vitamin D-deficient Middle-aged Women: A Randomized Clinical Trial

    Directory of Open Access Journals (Sweden)

    Behnaz Abiri

    2016-07-01

    Full Text Available Background and Objectives: Sarcopenia is explained as the loss of muscle strength and muscle mass with aging‚ and is one of the major risk factors for metabolic diseases. Cross-sectional studies demonstrate that vitamin D is associated with sarcopenia in both men and women. The aim of this study was to investigate the effect of vitamin D supplement consumption on muscle strength, muscle function and body composition in middle-aged women. Materials and Methods: In this randomized double-blind placebo-controlled trial, 71 women aged 40-55 years old, with the serum 25(OH-D <25 ng/ml, were divided in two groups randomly, and received a 1000 IU vitamin D tablet (n=37 or a placebo (n=34, daily for 12 weeks. At the beginning and at the end of the study, dietary intake, anthropometric indices, muscle strength and function, serum 25(OH-D, physical activity level and sun exposure were assessed. Statistical analysis was performed with SPSS version 20. Results: A significant difference in serum 25(OH-D was found between the intervention and placebo groups at the end of the study (P<0.001. In the vitamin D group, handgrip strength was improved, while hand grip strength (P=0.233 and knee extension strength (P=0.337 between the two groups did not differ significantly after 12 weeks. The mean of timed get up and go test, decreased significantly in the vitamin D group compared to the controls (P<0.001. Within the intervention group, body fat content decreased significantly after 12 weeks (P<0.001, but did not result a significant difference between the two groups (P=0.051. Conclusions: It seems in this vitamin D-deficient middle-aged women group, 1000 IU vitamin D consumption daily for 12 weeks resulted in improvement of muscle function and body composition, but had no significant effect on muscle strength. Keywords: Vitamin D, Muscle strength, Muscle function, Middle-aged women

  15. Interstitial pH in human skeletal muscle during and after dynamic graded exercise

    DEFF Research Database (Denmark)

    Street, D; Bangsbo, Jens; Juel, Carsten

    2001-01-01

    In this study a new method has been used to measure interstitial pH continuously in human muscle during graded exercise. Human subjects performed 5 min of one-legged knee-extensor exercise at power outputs of 30, 50 and 70 W. Muscle interstitial pH was measured continuously in microdialysis...

  16. Growth factor-induced contraction of human bronchial smooth muscle is Rho-kinase-dependent

    NARCIS (Netherlands)

    Gosens, Reinout; Schaafsma, D.; Grootte Bromhaar, M.M; Vrugt, B.; Zaagsma, Hans; Meurs, Herman; Nelemans, Herman

    2004-01-01

    Growth factors have been implicated in the pathophysiology of asthma. However, the putative effects of these growth factors on human airway smooth muscle tone are still largely unknown. We performed contraction experiments using human bronchial smooth muscle ring preparations. The growth factor

  17. Proteomics of Skeletal Muscle

    DEFF Research Database (Denmark)

    Deshmukh, Atul

    2016-01-01

    Skeletal muscle is the largest tissue in the human body and plays an important role in locomotion and whole body metabolism. It accounts for ~80% of insulin stimulated glucose disposal. Skeletal muscle insulin resistance, a primary feature of Type 2 diabetes, is caused by a decreased ability...... of muscle to respond to circulating insulin. Physical exercise improves insulin sensitivity and whole body metabolism and remains one of the most promising interventions for the prevention of Type 2 diabetes. Insulin resistance and exercise adaptations in skeletal muscle might be a cause, or consequence......, of altered protein expressions profiles and/or their posttranslational modifications (PTMs). Mass spectrometry (MS)-based proteomics offer enormous promise for investigating the molecular mechanisms underlying skeletal muscle insulin resistance and exercise-induced adaptation; however, skeletal muscle...

  18. Biomarkers of mitochondrial content in skeletal muscle of healthy young human subjects

    DEFF Research Database (Denmark)

    Larsen, Steen; Nielsen, Joachim; Neigaard Nielsen, Christina

    2012-01-01

    closely associated these commonly used biochemical measures are to muscle mitochondrial content and muscle oxidative capacity (OXPHOS).Sixteen young healthy male subjects were recruited for this study. Subjects completed a graded exercise test to determine maximal oxygen uptake (VO(2peak)) and muscle......Skeletal muscle mitochondrial content varies extensively between human subjects. Biochemical measures of mitochondrial proteins, enzyme activities and lipids are often used as markers of mitochondrial content and muscle oxidative capacity (OXPHOS). The purpose of this study was to determine how...... to muscle oxidative capacity followed by complex II activity.We conclude that cardiolipin content, CS and complex I activity are the biomarkers that exhibit the strongest association to mitochondrial content, while complex IV activity is strongly associated with OXPHOS capacity in human skeletal muscle....

  19. Subcellular localization and mechanism of secretion of vascular endothelial growth factor in human skeletal muscle

    DEFF Research Database (Denmark)

    Høier, Birgitte; Prats Gavalda, Clara; Qvortrup, Klaus

    2013-01-01

    The subcellular distribution and secretion of vascular endothelial growth factor (VEGF) was examined in skeletal muscle of healthy humans. Skeletal muscle biopsies were obtained from m.v. lateralis before and after a 2 h bout of cycling exercise. VEGF localization was conducted on preparations...... of teased muscle fibers by transmission electron microscopy (TEM) and confocal microscopy (CM). Muscle interstitial fluid was sampled from microdialysis probes placed in the thigh muscle. TEM and CM analysis revealed two primary sites of localization of VEGF: in vesicles located in the subsarcolemmal...... regions and between the contractile elements within the muscle fibers; and in pericytes situated on the skeletal muscle capillaries. Quantitation of the subsarcolemmal density of VEGF vesicles, calculated on top of myonuclei, in the muscle fibers revealed a ∼50% increase (P...

  20. Microvascular responses to body tilt in cutaneous maximus muscle of conscious rats

    Science.gov (United States)

    Puri, Rohit K.; Segal, Steven S.

    1994-01-01

    We investigated microvascular responses to head-up tilt (HUT) and head-down tilt (HDT) in striated muscle of conscious male rats. To observe the microcirculation in the cutaneous maximus muscle, a transparent polycarbonate chamber was implanted aseptically into a skin fold created between the shoulders. Rats were trained to sit quietly during HUT and HDT while positioned on a horizontal microscope that rotated in the sagittal plane. At 4-5 days after surgery, arteriole and venule diameters were recorded using videomicroscopy while the rat experienced 10 min each (in random order) of HUT or HDT at 20 deg or 40 deg separated by 2-h rest periods. HUT had no affect on microvessel diameter; 20 deg HDT had little affect. In response to 40 deg HDT, 'large' arterioles constricted by 18 +/- 2% and 'small' arterioles dilated by 21 +/- 3%; this difference suggested variation in mechanisms controlling arteriolar responses. Venules exhibited a larger fluctuation in diameter during 40 deg HDT compared with other body positions, suggesting that venomotor activity may be induced with sufficient fluid shift or change in central venous pressure. These observations illustrate a viable model for studying microvascular responses to gravitational stress in conscious rats.

  1. Effect of HMB supplementation on body composition, fitness, hormonal profile and muscle damage indices.

    Science.gov (United States)

    Portal, Shawn; Eliakim, Alon; Nemet, Dan; Halevy, Orna; Zadik, Zvi

    2010-07-01

    There is a huge market for ergogenic supplements for athletes. However, only a few products have been proven to have ergogenic effects and to be effective at improving muscle strength and body composition. One such supplement is beta-hydroxy beta-methylbutyrate (HMB). Derived from the amino acid leucine and its keto acid alpha-ketoisocaproate (KIC), HMB has been well documented as an oral ergogenic supplement commonly used by athletes. Several studies have shown that combining exercise training with HMB supplementation leads to increased muscle mass and strength, and there is some anecdotal evidence of aerobic improvement. However, HMB supplementation has been found to be effective mainly for untrained individuals. While previous reviews have emphasized three main pathways for HMB's mode of action: 1) enhancement of sarcolemmal integrity via cytosolic cholesterol, 2) inhibition of protein degradation via proteasomes, and 3) increased protein synthesis via the mTOR pathway, more recent studies have suggested additional possible mechanisms for its physiological effects. These include decreased cell apoptosis and enhanced cell survival, increased proliferation, differentiation and fusion via the MAPK/ERK and PI3K/Akt pathways, and enhanced IGF-I transcription. These are described here, and hormonal interactions are discussed, along with HMB dosage and safety issues.

  2. The role of human ankle plantar flexor muscle-tendon interaction and architecture in maximal vertical jumping examined in vivo.

    Science.gov (United States)

    Farris, Dominic James; Lichtwark, Glen A; Brown, Nicholas A T; Cresswell, Andrew G

    2016-02-01

    Humans utilise elastic tendons of lower limb muscles to store and return energy during walking, running and jumping. Anuran and insect species use skeletal structures and/or dynamics in conjunction with similarly compliant structures to amplify muscle power output during jumping. We sought to examine whether human jumpers use similar mechanisms to aid elastic energy usage in the plantar flexor muscles during maximal vertical jumping. Ten male athletes performed maximal vertical squat jumps. Three-dimensional motion capture and a musculoskeletal model were used to determine lower limb kinematics that were combined with ground reaction force data in an inverse dynamics analysis. B-mode ultrasound imaging of the lateral gastrocnemius (GAS) and soleus (SOL) muscles was used to measure muscle fascicle lengths and pennation angles during jumping. Our results highlighted that both GAS and SOL utilised stretch and recoil of their series elastic elements (SEEs) in a catapult-like fashion, which likely serves to maximise ankle joint power. The resistance of supporting of body weight allowed initial stretch of both GAS and SOL SEEs. A proximal-to-distal sequence of joint moments and decreasing effective mechanical advantage early in the extension phase of the jumping movement were observed. This facilitated a further stretch of the SEE of the biarticular GAS and delayed recoil of the SOL SEE. However, effective mechanical advantage did not increase late in the jump to aid recoil of elastic tissues. © 2016. Published by The Company of Biologists Ltd.

  3. An improved method to determine neuromuscular properties using force laws - From single muscle to applications in human movements.

    Science.gov (United States)

    Siebert, T; Sust, M; Thaller, S; Tilp, M; Wagner, H

    2007-04-01

    We evaluate an improved method for individually determining neuromuscular properties in vivo. The method is based on Hill's equation used as a force law combined with Newton's equation of motion. To ensure the range of validity of Hill's equation, we first perform detailed investigations on in vitro single muscles. The force-velocity relation determined with the model coincides well with results obtained by standard methods (r=.99) above 20% of the isometric force. In addition, the model-predicted force curves during work loop contractions very well agree with measurements (mean difference: 2-3%). Subsequently, we deduce theoretically under which conditions it is possible to combine several muscles of the human body to model muscles. This leads to a model equation for human leg extension movements containing parameters for the muscle properties and for the activation. To numerically determine these invariant neuromuscular properties we devise an experimental method based on concentric and isometric leg extensions. With this method we determine individual muscle parameters from experiments such that the simulated curves agree well with experiments (r=.99). A reliability test with 12 participants revealed correlations r=.72-.91 for the neuromuscular parameters (p<.01). Predictions of similar movements under different conditions show mean errors of about 5%. In addition, we present applications in sports practise and theory.

  4. Governing the postmortem procurement of human body material for research.

    Science.gov (United States)

    Van Assche, Kristof; Capitaine, Laura; Pennings, Guido; Sterckx, Sigrid

    2015-03-01

    Human body material removed post mortem is a particularly valuable resource for research. Considering the efforts that are currently being made to study the biochemical processes and possible genetic causes that underlie cancer and cardiovascular and neurodegenerative diseases, it is likely that this type of research will continue to gain in importance. However, post mortem procurement of human body material for research raises specific ethical concerns, more in particular with regard to the consent of the research participant. In this paper, we attempt to determine which consent regime should govern the post mortem procurement of body material for research. In order to do so, we assess the various arguments that could be put forward in support of a duty to make body material available for research purposes after death. We argue that this duty does in practice not support conscription but is sufficiently strong to defend a policy of presumed rather than explicit consent.

  5. The Human-Body-in-Coordination as Perceptual Instrument

    Directory of Open Access Journals (Sweden)

    Harrison Steven J.

    2011-12-01

    Full Text Available Recent evidence suggests that the human body in locomotor coordination performs dual roles, acting to propel the body over the surface of support, and embodying haptic information arising from and specific to the movement of the body as a whole with respect to the substrate. Here we show that blindfolded human subjects, trained to crawl using gait patterns that differed in the spatio-temporal symmetries defined with respect to the arms and legs in coordination, perceived distance travelled quadrupedally. These results suggest that 1 the body in coordination gives rise to a haptic measure of how one is moving through the world relative to the substrate and 2 that the measure that results is specific to the softly assembled global organization of the locomotor action system.

  6. Metabolic control of muscle blood flow during exercise in humans

    DEFF Research Database (Denmark)

    Boushel, Robert Christopher

    2003-01-01

    During muscle contraction, several mechanisms regulate blood flow to ensure a close coupling between muscle oxygen delivery and metabolic demand. No single factor has been identified to constitute the primary metabolic regulator, yet there are signal transduction pathways between skeletal muscle...

  7. A predictive model of muscle excitations based on muscle modularity for a large repertoire of human locomotion conditions

    Directory of Open Access Journals (Sweden)

    Jose eGonzalez-Vargas

    2015-09-01

    Full Text Available Humans can efficiently walk across a large variety of terrains and locomotion conditions with little or no mental effort. It has been hypothesized that the nervous system simplifies neuromuscular control by using muscle synergies, thus organizing multi-muscle activity into a small number of coordinative co-activation modules. In the present study we investigated how muscle modularity is structured across a large repertoire of locomotion conditions including five different speeds and five different ground elevations. For this we have used the non-negative matrix factorization technique in order to explain EMG experimental data with a low-dimensional set of four motor components. In this context each motor components is composed of a non-negative factor and the associated muscle weightings. Furthermore, we have investigated if the proposed descriptive analysis of muscle modularity could be translated into a predictive model that could: 1 Estimate how motor components modulate across locomotion speeds and ground elevations. This implies not only estimating the non-negative factors temporal characteristics, but also the associated muscle weighting variations. 2 Estimate how the resulting muscle excitations modulate across novel locomotion conditions and subjects.The results showed three major distinctive features of muscle modularity: 1 the number of motor components was preserved across all locomotion conditions, 2 the non-negative factors were consistent in shape and timing across all locomotion conditions, and 3 the muscle weightings were modulated as distinctive functions of locomotion speed and ground elevation. Results also showed that the developed predictive model was able to reproduce well the muscle modularity of un-modeled data, i.e. novel subjects and conditions. Muscle weightings were reconstructed with a cross-correlation factor greater than 70% and a root mean square error less than 0.10. Furthermore, the generated muscle excitations

  8. A predictive model of muscle excitations based on muscle modularity for a large repertoire of human locomotion conditions.

    Science.gov (United States)

    Gonzalez-Vargas, Jose; Sartori, Massimo; Dosen, Strahinja; Torricelli, Diego; Pons, Jose L; Farina, Dario

    2015-01-01

    Humans can efficiently walk across a large variety of terrains and locomotion conditions with little or no mental effort. It has been hypothesized that the nervous system simplifies neuromuscular control by using muscle synergies, thus organizing multi-muscle activity into a small number of coordinative co-activation modules. In the present study we investigated how muscle modularity is structured across a large repertoire of locomotion conditions including five different speeds and five different ground elevations. For this we have used the non-negative matrix factorization technique in order to explain EMG experimental data with a low-dimensional set of four motor components. In this context each motor components is composed of a non-negative factor and the associated muscle weightings. Furthermore, we have investigated if the proposed descriptive analysis of muscle modularity could be translated into a predictive model that could: (1) Estimate how motor components modulate across locomotion speeds and ground elevations. This implies not only estimating the non-negative factors temporal characteristics, but also the associated muscle weighting variations. (2) Estimate how the resulting muscle excitations modulate across novel locomotion conditions and subjects. The results showed three major distinctive features of muscle modularity: (1) the number of motor components was preserved across all locomotion conditions, (2) the non-negative factors were consistent in shape and timing across all locomotion conditions, and (3) the muscle weightings were modulated as distinctive functions of locomotion speed and ground elevation. Results also showed that the developed predictive model was able to reproduce well the muscle modularity of un-modeled data, i.e., novel subjects and conditions. Muscle weightings were reconstructed with a cross-correlation factor greater than 70% and a root mean square error less than 0.10. Furthermore, the generated muscle excitations matched

  9. Segmentation of human upper body movement using multiple IMU sensors.

    Science.gov (United States)

    Aoki, Takashi; Lin, Jonathan Feng-Shun; Kulic, Dana; Venture, Gentiane

    2016-08-01

    This paper proposes an approach for the segmentation of human body movements measured by inertial measurement unit sensors. Using the angular velocity and linear acceleration measurements directly, without converting to joint angles, we perform segmentation by formulating the problem as a classification problem, and training a classifier to differentiate between motion end-point and within-motion points. The proposed approach is validated with experiments measuring the upper body movement during reaching tasks, demonstrating classification accuracy of over 85.8%.

  10. Reduced short-interval intracortical inhibition after eccentric muscle damage in human elbow flexor muscles.

    Science.gov (United States)

    Pitman, Bradley M; Semmler, John G

    2012-09-01

    The purpose of this study was to use paired-pulse transcranial magnetic stimulation (TMS) to examine the effect of eccentric exercise on short-interval intracortical inhibition (SICI) after damage to elbow flexor muscles. Nine young (22.5 ± 0.6 yr; mean ± SD) male subjects performed maximal eccentric exercise of the elbow flexor muscles until maximal voluntary contraction (MVC) force was reduced by ∼40%. TMS was performed before, 2 h after, and 2 days after exercise under Rest and Active (5% MVC) conditions with motor-evoked potentials (MEPs) recorded from the biceps brachii (BB) muscle. Peripheral electrical stimulation of the brachial plexus was used to assess maximal M-waves, and paired-pulse TMS with a 3-ms interstimulus interval was used to assess changes in SICI at each time point. The eccentric exercise resulted in a 34% decline in strength (P muscle strength (27%, P muscle soreness (P muscle damage. When the test MEP amplitudes were matched between sessions, we found that SICI was reduced by 27% in resting and 23% in active BB muscle 2 h after exercise. SICI recovered 2 days after exercise when muscle pain and soreness were present, suggesting that delayed onset muscle soreness from eccentric exercise does not influence SICI. The change in SICI observed 2 h after exercise suggests that eccentric muscle damage has widespread effects throughout the motor system that likely includes changes in motor cortex.

  11. Fat Body dSir2 Regulates Muscle Mitochondrial Physiology and Energy Homeostasis Nonautonomously and Mimics the Autonomous Functions of dSir2 in Muscles

    Science.gov (United States)

    Banerjee, Kushal K.; Ayyub, Champakali; Sengupta, Samudra

    2013-01-01

    Sir2 is an evolutionarily conserved NAD+-dependent deacetylase which has been shown to play a critical role in glucose and fat metabolism. In this study, we have perturbed Drosophila Sir2 (dSir2) expression, bidirectionally, in muscles and the fat body. We report that dSir2 plays a critical role in insulin signaling, glucose homeostasis, and mitochondrial functions. Importantly, we establish the nonautonomous functions of fat body dSir2 in regulating mitochondrial physiology and insulin signaling in muscles. We have identified a novel interplay between dSir2 and dFOXO at an organismal level, which involves Drosophila insulin-like peptide (dILP)-dependent insulin signaling. By genetic perturbations and metabolic rescue, we provide evidence to illustrate that fat body dSir2 mediates its effects on the muscles via free fatty acids (FFA) and dILPs (from the insulin-producing cells [IPCs]). In summary, we show that fat body dSir2 is a master regulator of organismal energy homeostasis and is required for maintaining the metabolic regulatory network across tissues. PMID:23129806

  12. Regulation of skeletal muscle energy/nutrient-sensing pathways during metabolic adaptation to fasting in healthy humans.

    Science.gov (United States)

    Wijngaarden, Marjolein A; Bakker, Leontine E H; van der Zon, Gerard C; 't Hoen, Peter A C; van Dijk, Ko Willems; Jazet, Ingrid M; Pijl, Hanno; Guigas, Bruno

    2014-11-15

    During fasting, rapid metabolic adaptations are required to maintain energy homeostasis. This occurs by a coordinated regulation of energy/nutrient-sensing pathways leading to transcriptional activation and repression of specific sets of genes. The aim of the study was to investigate how short-term fasting affects whole body energy homeostasis and skeletal muscle energy/nutrient-sensing pathways and transcriptome in humans. For this purpose, 12 young healthy men were studied during a 24-h fast. Whole body glucose/lipid oxidation rates were determined by indirect calorimetry, and blood and skeletal muscle biopsies were collected and analyzed at baseline and after 10 and 24 h of fasting. As expected, fasting induced a time-dependent decrease in plasma insulin and leptin levels, whereas levels of ketone bodies and free fatty acids increased. This was associated with a metabolic shift from glucose toward lipid oxidation. At the molecular level, activation of the protein kinase B (PKB/Akt) and mammalian target of rapamycin pathways was time-dependently reduced in skeletal muscle during fasting, whereas the AMP-activated protein kinase activity remained unaffected. Furthermore, we report some changes in the phosphorylation and/or content of forkhead protein 1, sirtuin 1, and class IIa histone deacetylase 4, suggesting that these pathways might be involved in the transcriptional adaptation to fasting. Finally, transcriptome profiling identified genes that were significantly regulated by fasting in skeletal muscle at both early and late time points. Collectively, our study provides a comprehensive map of the main energy/nutrient-sensing pathways and transcriptomic changes during short-term adaptation to fasting in human skeletal muscle.

  13. Air temperature investigation in microenvironment around a human body

    DEFF Research Database (Denmark)

    Licina, Dusan; Melikov, Arsen Krikor; Sekhar, Chandra;

    2015-01-01

    The aim of this study is to investigate the temperature boundary layer around a human body in a quiescent indoor environment. The air temperature, mean in time and standard deviation of the temperature fluctuations around a breathing thermal manikin are examined in relation to the room temperature......, body posture and human respiratory flow. To determine to what extent the experiments represent the realistic scenario, the additional experiments were performed with a real human subject. The results show that at a lower room air temperature (20°C), the fluctuations of air temperature increased close...... to the surface of the body. The large standard deviation of air temperature fluctuations, up to 1.2°C, was recorded in the region of the chest, and up to 2.9°C when the exhalation was applied. The manikin leaned backwards increased the air temperature in the breathing zone, which was opposite from the forward...

  14. Optimization study of using PTC for human body heating dissipation

    Directory of Open Access Journals (Sweden)

    Tiberiu Adrian SALAORU

    2014-06-01

    Full Text Available A better knowledge of the human body heat loses mechanisms is important for both diminishing the number of deaths during the surgical procedures of the patients under effect of full anaesthesia and increasing the efficiency of the Heating, Ventilation and Air Conditioning (HVAC systems. For these studies it is necessary to manufacture a human body mannequin having its surface temperature maintained on a value close to the real human body temperature. A number of PTC (Positive Temperature Coefficient thermistors placed on the entire external surface of the mannequin can be used for this purpose. This paper presents a study of the transient heating regime and the stability of the maintained temperature, performed on these devices.

  15. The physiological role of fat body and muscle tissues in response to cold stress in the tropical cockroach Gromphadorhina coquereliana.

    Science.gov (United States)

    Chowański, Szymon; Lubawy, Jan; Paluch-Lubawa, Ewelina; Spochacz, Marta; Rosiński, Grzegorz; Słocińska, Małgorzata

    2017-01-01

    Protective mechanisms against cold stress are well studied in terrestrial and polar insects; however, little is known about these mechanisms in tropical insects. In our study, we tested if a tropical cockroach Gromphadorhina coquereliana, possesses any protective mechanisms against cold stress. Based on the results of earlier studies, we examined how short-term (3 h) cold (4°C) influences biochemical parameters, mitochondrial respiration activity, and the level of HSPs and aquaporins expression in the fat body and leg muscles of G. coquereliana. Following cold exposure, we found that the level of carbohydrates, lipids and proteins did not change significantly. Nevertheless, we observed significant changes in mitochondrial respiration activity. The oxygen consumption of resting (state 4) and phosphorylating (state 3) mitochondria was altered following cold exposure. The increase in respiratory rate in state 4 respiration was observed in both tissues. In state 3, oxygen consumption by mitochondria in fat body was significantly lower compared to control insects, whereas there were no changes observed for mitochondria in muscle tissue. Moreover, there were cold-induced changes in UCP protein activity, but the changes in activity differed in fat body and in muscles. Additionally, we detected changes in the level of HSP70 and aquaporins expression. Insects treated with cold had significantly higher levels of HSP70 in fat body and muscles. On the other hand, there were lower levels of aquaporins in both tissues following exposure to cold. These results suggest that fat body play an important role in protecting tropical insects from cold stress.

  16. Gender recognition from unconstrained and articulated human body.

    Science.gov (United States)

    Wu, Qin; Guo, Guodong

    2014-01-01

    Gender recognition has many useful applications, ranging from business intelligence to image search and social activity analysis. Traditional research on gender recognition focuses on face images in a constrained environment. This paper proposes a method for gender recognition in articulated human body images acquired from an unconstrained environment in the real world. A systematic study of some critical issues in body-based gender recognition, such as which body parts are informative, how many body parts are needed to combine together, and what representations are good for articulated body-based gender recognition, is also presented. This paper also pursues data fusion schemes and efficient feature dimensionality reduction based on the partial least squares estimation. Extensive experiments are performed on two unconstrained databases which have not been explored before for gender recognition.

  17. Identification of rheological properties of human body surface tissue.

    Science.gov (United States)

    Benevicius, Vincas; Gaidys, Rimvydas; Ostasevicius, Vytautas; Marozas, Vaidotas

    2014-04-11

    According to World Health Organization obesity is one of the greatest public health challenges of the 21st century. It has tripled since the 1980s and the numbers of those affected continue to rise at an alarming rate, especially among children. There are number of devices that act as a prevention measure to boost person's motivation for physical activity and its levels. The placement of these devices is not restricted thus the measurement errors that appear because of the body rheology, clothes, etc. cannot be eliminated. The main objective of this work is to introduce a tool that can be applied directly to process measured accelerations so human body surface tissue induced errors can be reduced. Both the modeling and experimental techniques are proposed to identify body tissue rheological properties and prelate them to body mass index. Multi-level computational model composed from measurement device model and human body surface tissue rheological model is developed. Human body surface tissue induced inaccuracies can increase the magnitude of measured accelerations up to 34% when accelerations of the magnitude of up to 27 m/s(2) are measured. Although the timeframe of those disruptions are short - up to 0.2 s - they still result in increased overall measurement error.

  18. No release of interstitial glutamate in experimental human model of muscle pain

    DEFF Research Database (Denmark)

    Ashina, M.; Jørgensen, M.; Stallknecht, Bente;

    2005-01-01

    Glutamate may be released from muscle nociceptors and thereby contribute to mechanisms underlying acute and chronic muscle pain. In vivo concentration of glutamate during muscle pain has not previously been studied in either animals or humans. In the present study, we aimed to study the in vivo...... flow increased significantly over time in response to infusion of chemical mixture and placebo (p = 0.001). However, we found no difference in changes in muscle blood flow between chemical mixture and placebo (p > 0.05). In conclusion, the present study demonstrates no signs of increased release...... of glutamate from myofascial nociceptors during and after acute experimentally induced muscle pain and tenderness....

  19. More-Realistic Digital Modeling of a Human Body

    Science.gov (United States)

    Rogge, Renee

    2010-01-01

    A MATLAB computer program has been written to enable improved (relative to an older program) modeling of a human body for purposes of designing space suits and other hardware with which an astronaut must interact. The older program implements a kinematic model based on traditional anthropometric measurements that do provide important volume and surface information. The present program generates a three-dimensional (3D) whole-body model from 3D body-scan data. The program utilizes thin-plate spline theory to reposition the model without need for additional scans.

  20. Emergency Handling for MAC Protocol in Human Body Communication

    Directory of Open Access Journals (Sweden)

    Kwon Youngmi

    2011-01-01

    Full Text Available The human body communication (HBC is a technology that enables short range data communication using the human body as a medium, like an electrical wire. Thus it removes the need for a traditional antenna. HBC may be used as a type of data communication in body area network (BAN, while the devices are being in contact with body. One of important issues in BAN is an emergency alarm because it may be closely related to human life. For emergency data communication, the most critical factor is the time constraint. IEEE 802.15.6 specifies that the emergency alarm for the BAN must be notified in less than 1 sec and must provide prioritization mechanisms for emergency traffic and notification. As one type of BAN, the HBC must follow this recommendation, too. Existing emergency handling methods in BAN are based on the carrier sensing capability on radio frequencies to detect the status of channels. However, PHY protocol in HBC does not provide the carrier sensing. So the previous methods are not well suitable for HBC directly. Additionally, in the environment that the emergency rate is very low, the allocation of dedicated slot(s for emergency in each superframe is very wasteful. In this work, we proposed specific emergency handling operation for human body communication's medium access control (HBC-MAC protocol to meet the emergency requirements for BAN. We also showed the optimal number of emergency slots for the various combinations of beacon intervals and emergency rates.

  1. Expression of interleukin-15 in human skeletal muscle effect of exercise and muscle fibre type composition

    DEFF Research Database (Denmark)

    Nielsen, Anders Rinnov; Mounier, Remi; Plomgaard, Peter

    2007-01-01

    of recovery without any changes in muscle IL-15 protein content or plasma IL-15 at any of the investigated time points. In conclusion, IL-15 mRNA level is enhanced in skeletal muscles dominated by type 2 fibres and resistance exercise induces increased muscular IL-15 mRNA levels. IL-15 mRNA levels in skeletal......The cytokine interleukin-15 (IL-15) has been demonstrated to have anabolic effects in cell culture systems. We tested the hypothesis that IL-15 is predominantly expressed by type 2 skeletal muscle fibres, and that resistance exercise regulates IL-15 expression in muscle. Triceps brachii, vastus...... lateralis quadriceps and soleus muscle biopsies were obtained from normally physically active, healthy, young male volunteers (n = 14), because these muscles are characterized by having different fibre-type compositions. In addition, healthy, normally physically active male subjects (n = 8) not involved...

  2. Biostereometric Data Processing In ERGODATA: Choice Of Human Body Models

    Science.gov (United States)

    Pineau, J. C.; Mollard, R.; Sauvignon, M.; Amphoux, M.

    1983-07-01

    The definition of human body models was elaborated with anthropometric data from ERGODATA. The first model reduces the human body into a series of points and lines. The second model is well adapted to represent volumes of each segmentary element. The third is an original model built from the conventional anatomical points. Each segment is defined in space by a tri-angular plane located with its 3-D coordinates. This new model can answer all the processing possibilities in the field of computer-aided design (C.A.D.) in ergonomy but also biomechanics and orthopaedics.

  3. Three-dimensional modeling of supine human and transport system under whole-body vibration.

    Science.gov (United States)

    Wang, Yang; Rahmatalla, Salam

    2013-06-01

    The development of predictive computer human models in whole-body vibration has shown some success in predicting simple types of motion, mostly for seated positions and in the uniaxial vertical direction. The literature revealed only a handful of papers that tackled supine human modeling in response to vertical vibration. The objective of this work is to develop a predictive, multibody, three-dimensional human model to simulate the supine human and underlying transport system in response to multidirectional whole-body vibration. A three-dimensional dynamic model of a supine human and its underlying transport system is presented in this work to predict supine-human biodynamic response under three-dimensional input random whole-body vibration. The proposed supine-human model consists of three interconnected segments representing the head, torso-arms, and pelvis-legs. The segments are connected via rotational and translational joints that have spring-damper components simulating the three-dimensional muscles and tissuelike connecting elements in the three x, y, and z directions. Two types of transport systems are considered in this work, a rigid support and a long spinal board attached to a standard military litter. The contact surfaces between the supine human and the underlying transport system are modeled using spring-damper components. Eight healthy supine human subjects were tested under combined-axis vibration files with a magnitude of 0.5 m/s2 (rms) and a frequency content of 0.5-16 Hz. The data from seven subjects were used in parameter identification for the dynamic model using optimization schemes in the frequency domain that minimize the differences between the magnitude and phase of the predicted and experimental transmissibility. The predicted accelerations in the time and frequency domains were comparable to those gathered from experiments under different anthropometric, input vibration, and transport conditions under investigation. Based on the

  4. The Reconfigured Body. Human-animal relations in xenotransplantation

    Directory of Open Access Journals (Sweden)

    Kristofer Hansson

    2011-12-01

    Full Text Available The article explores issues concerning the reconfiguration of human and animal bodies in modern biotechnology. The examples are based on xenotransplantation: Transplantation of cells, tissue and organs from animals to humans. Three thematic issues that emerged from xenotransplantation research in Sweden in the 1990s and early 2000s are examined in the article. The first issue concerns how the pig was introduced as a donor animal in xenotransplantation and, at the same time, dehumanized in relation to what is human. Baboons and chimpanzees that had previously been used in xenotransplantation now became an ethically problematic choice, and were in stead humanized. The second issue concerns the introduction of transgenic and cloned pigs as commoditized objects. The biotechnological development reconfigured the pig’s cells, tissue and organs to become more human-like. The third issue concerns the risk that pigs contain retrovirus that could infect the transplanted patients. The human body became part of a network of both animal and retrovirus. Boundlessness between human and animal bodies appears in these three thematic phases and is analysed from a cultural perspective.

  5. Inclusion bodies in loggerhead erythrocytes are associated with unstable hemoglobin and resemble human Heinz bodies.

    Science.gov (United States)

    Basile, Filomena; Di Santi, Annalisa; Caldora, Mercedes; Ferretti, Luigi; Bentivegna, Flegra; Pica, Alessandra

    2011-08-01

    The aim of this study was to clarify the role of the erythrocyte inclusions found during the hematological screening of loggerhead population of the Mediterranean Sea. We studied the erythrocyte inclusions in blood specimens collected from six juvenile and nine adult specimens of the loggerhead turtle, Caretta caretta, from the Adriatic and Tyrrhenian Seas. Our study indicates that the percentage of mature erythrocytes containing inclusions ranged from 3 to 82%. Each erythrocyte contained only one round inclusion body. Inclusion bodies stained with May Grünwald-Giemsa show that their cytochemical and ultrastructure characteristics are identical to those of human Heinz bodies. Because Heinz bodies originate from the precipitation of unstable hemoglobin (Hb) and cause globular osmotic resistance to increase, we analyzed loggerhead Hb using electrophoresis and high-performance liquid chromatography to detect and quantitate Hb fractions. We also tested the resistance of Hb to alkaline pH, heat, isopropanol denaturation, and globular osmosis. Our hemogram results excluded the occurrence of any infection, which could be associated with an inclusion body, in all the specimens. Negative Feulgen staining indicated that the inclusion bodies are not derived from DNA fragmentation. We hypothesize that amino acid substitutions could explain why loggerhead Hb precipitates under normal physiologic conditions, forming Heinz bodies. The identification of inclusion bodies in loggerhead erythrocytes allow us to better understand the haematological characteristics and the physiology of these ancient reptiles, thus aiding efforts to conserve such an endangered species. Copyright © 2011 Wiley-Liss, Inc., A Wiley Company.

  6. Muscle activation during maximal effort tasks: evidence of the selective forces that shaped the musculoskeletal system of humans.

    Science.gov (United States)

    Carrier, David R; Schilling, Nadja; Anders, Christoph

    2015-11-04

    The selective forces that played a role in the evolution of the musculoskeletal system of the genus Homo have long been debated and remain poorly understood. In this investigation, we introduce a new approach for testing alternative hypotheses. Our analysis is based on the premise that natural selection can be expected to have resulted in muscles that are large enough to achieve necessary levels of maximum performance in essential behaviors, but not larger. We used surface electromyography in male subjects to identify maximum activation levels in 13 muscles of the back and leg during eight behaviors that have been suggested to have been important to foraging, hunting and fighting performance in early humans. We asked two questions: (1) what behaviors produce maximum activation in each of the investigated muscles and (2) are there specific behaviors that elicit maximum recruitment from all or most of the muscles? We found that in eight of the 13 muscles, the highest activity occurred during maximal effort vertical jumping (i.e. whole-body acceleration). Punching produced the highest median activity in the other five muscles. Together, jumping and punching accounted for 73% of the incidences of maximum activity among all of the muscles and from all of the subjects. Thus, the size of the muscles of the back and leg appear to be more related to the demands of explosive behaviors rather than those of high speed sprinting or sustained endurance running. These results are consistent with the hypothesis that selection on aggressive behavior played an important role in the evolution of the genus Homo.

  7. Muscle activation during maximal effort tasks: evidence of the selective forces that shaped the musculoskeletal system of humans

    Directory of Open Access Journals (Sweden)

    David R. Carrier

    2015-12-01

    Full Text Available The selective forces that played a role in the evolution of the musculoskeletal system of the genus Homo have long been debated and remain poorly understood. In this investigation, we introduce a new approach for testing alternative hypotheses. Our analysis is based on the premise that natural selection can be expected to have resulted in muscles that are large enough to achieve necessary levels of maximum performance in essential behaviors, but not larger. We used surface electromyography in male subjects to identify maximum activation levels in 13 muscles of the back and leg during eight behaviors that have been suggested to have been important to foraging, hunting and fighting performance in early humans. We asked two questions: (1 what behaviors produce maximum activation in each of the investigated muscles and (2 are there specific behaviors that elicit maximum recruitment from all or most of the muscles? We found that in eight of the 13 muscles, the highest activity occurred during maximal effort vertical jumping (i.e. whole-body acceleration. Punching produced the highest median activity in the other five muscles. Together, jumping and punching accounted for 73% of the incidences of maximum activity among all of the muscles and from all of the subjects. Thus, the size of the muscles of the back and leg appear to be more related to the demands of explosive behaviors rather than those of high speed sprinting or sustained endurance running. These results are consistent with the hypothesis that selection on aggressive behavior played an important role in the evolution of the genus Homo.

  8. HMGB1 and RAGE in skeletal muscle inflammation: Implications for protein accumulation in inclusion body myositis.

    Science.gov (United States)

    Muth, Ingrid E; Zschüntzsch, Jana; Kleinschnitz, Konstanze; Wrede, Arne; Gerhardt, Ellen; Balcarek, Peter; Schreiber-Katz, Olivia; Zierz, Stephan; Dalakas, Marinos C; Voll, Reinhard E; Schmidt, Jens

    2015-09-01

    Inflammation is associated with protein accumulation in IBM, but precise mechanisms are elusive. The "alarmin" HMGB1 is upregulated in muscle inflammation. Its receptor RAGE is crucial for β-amyloid-associated neurodegeneration. Relevant signaling via HMGB1/RAGE is expected in IBM pathology. By real-time-PCR, mRNA-expression levels of HMGB1 and RAGE were upregulated in muscle biopsies of patients with IBM and PM, but not in muscular dystrophy or non-myopathic controls. By immunohistochemistry, both molecules displayed the highest signal in IBM, where they distinctly co-localized to intra-fiber accumulations of β-amyloid and neurofilament/tau. In these fibers, identification of phosphorylated Erk suggested that relevant downstream activation is present upon HMGB1 signaling via RAGE. Protein expressions of HMGB1, RAGE, Erk and phosphorylated Erk were confirmed by Western blot. In a well established cell-culture model for pro-inflammatory cell-stress, exposure of human muscle-cells to IL-1β+IFN-γ induced cytoplasmic translocation of HMGB1 and subsequent release as evidenced by ELISA. Upregulation of RAGE on the cell surface was demonstrated by immunocytochemistry and flow-cytometry. Recombinant HMGB1 was equally potent as IL-1β+IFN-γ in causing amyloid-accumulation and cell-death, and both were abrogated by the HMGB1-blocker BoxA. The findings strengthen the concept of unique interactions between degenerative and inflammatory mechanisms and suggest that HMGB1/RAGE signaling is a critical pathway in IBM pathology.

  9. The relationship between skeletal muscle mitochondrial citrate synthase activity and whole body oxygen uptake adaptations in response to exercise training

    DEFF Research Database (Denmark)

    Vigelsø Hansen, Andreas; Andersen, Nynne Bjerre; Dela, Flemming

    2014-01-01

    Citrate synthase (CS) activity is a validated biomarker for mitochondrial density in skeletal muscle. CS activity is also used as a biochemical marker of the skeletal muscle oxidative adaptation to a training intervention, and a relationship between changes in whole body aerobic capacity and chan.......4). Training induced changes in whole body oxidative capacity is matched by changes in muscle CS activity in a nearly 1:1 relationship. Absolute values of CS across different studies cannot be compared unless a standardized analytical method is used by all laboratories......Citrate synthase (CS) activity is a validated biomarker for mitochondrial density in skeletal muscle. CS activity is also used as a biochemical marker of the skeletal muscle oxidative adaptation to a training intervention, and a relationship between changes in whole body aerobic capacity...... and changes in CS activity is often assumed. However, this relationship and absolute values of CS and maximal oxygen uptake (V.O2max) has never been assessed across different studies. A systematic PubMed search on literature published from 1983 to 2013 was performed. The search profile included: citrate...

  10. The relationship between skeletal muscle mitochondrial citrate synthase activity and whole body oxygen uptake adaptations in response to exercise training

    DEFF Research Database (Denmark)

    Vigelsø, Andreas; Andersen, Nynne B; Dela, Flemming

    2014-01-01

    Citrate synthase (CS) activity is a validated biomarker for mitochondrial density in skeletal muscle. CS activity is also used as a biochemical marker of the skeletal muscle oxidative adaptation to a training intervention, and a relationship between changes in whole body aerobic capacity and chan.......4). Training induced changes in whole body oxidative capacity is matched by changes in muscle CS activity in a nearly 1:1 relationship. Absolute values of CS across different studies cannot be compared unless a standardized analytical method is used by all laboratories.......Citrate synthase (CS) activity is a validated biomarker for mitochondrial density in skeletal muscle. CS activity is also used as a biochemical marker of the skeletal muscle oxidative adaptation to a training intervention, and a relationship between changes in whole body aerobic capacity...... and changes in CS activity is often assumed. However, this relationship and absolute values of CS and maximal oxygen uptake (V.O2max) has never been assessed across different studies. A systematic PubMed search on literature published from 1983 to 2013 was performed. The search profile included: citrate...

  11. Body position effects on EMG activity of sternocleidomastoid and masseter muscles in patients with myogenic cranio-cervical-mandibular dysfunction.

    Science.gov (United States)

    Palazzi, C; Miralles, R; Soto, M A; Santander, H; Zuñiga, C; Moya, H

    1996-07-01

    This study was conducted in order to determine the effects of body position on integrated electromyographic (IEMG) activity of sternocleidomastoid and masseter muscles in 17 patients with myogenic cranio-cervical-mandibular dysfunction. EMG recordings at rest and during swallowing of saliva and maximal voluntary clenching were performed by placing surface electrodes on the sternocleidomastoid and masseter muscles (contralateral to the habitual side of sleeping of each patient), in the following body positions: standing, seated, supine, and lateral decubitus position. Significant higher EMG activities were recorded in the sternocleidomastoid muscle in the lateral decubitus position and in the supine position (except during swallowing), whereas a significant higher EMG activity was recorded in the masseter muscle during maximal voluntary clenching in standing and seated positions. The EMG pattern observed suggests that the presence of parafunctional habits and body position could be closely correlated with the clinical symptomatology in the sternocleidomastoid and masseter muscles at wakening and during waking hours, respectively, in patients with myogenic cranio-cervical-mandibular dysfunction.

  12. Skeletal muscle characterization of Japanese quail line selectively bred for lower body weight as an avian model of delayed muscle growth with hypoplasia.

    Science.gov (United States)

    Choi, Young Min; Suh, Yeunsu; Shin, Sangsu; Lee, Kichoon

    2014-01-01

    This study was designed to extensively characterize the skeletal muscle development in the low weight (LW) quail selected from random bred control (RBC) Japanese quail in order to provide a new avian model of impaired and delayed growth in physically normal animals. The LW line had smaller embryo and body weights than the RBC line in all age groups (Pmuscle (PM), mainly resulting from lower fiber numbers compared to the RBC line (Pgrowth with prolonged expression of Pax7 and lower expression levels of MyoD, Myf-5, and myogenin (Pmuscle fiber formation. Additionally, the LW line had delayed transition of neonatal to adult myosin heavy chain isoform, suggesting delayed muscle maturation. This is further supported by the finding that the LW line continued to grow unlike the RBC line; difference in the percentages of PMW to body weights between both quail lines diminished with increasing age from 42 to 75 d post-hatch. This delayed muscle growth in the LW line is accompanied by higher levels of myogenin expression at 42 d (Pmuscle development of the LW quail line provided a well-characterized avian model for future identification of the responsible genes and for studying mechanisms of hypoplasia and delayed muscle growth.

  13. Suction-modified needle biopsy technique for the human soleus muscle.

    Science.gov (United States)

    Cotter, Joshua A; Yu, Alvin; Kreitenberg, Arthur; Haddad, Fadia H; Baker, Michael J; Fox, John C; Adams, Gregory R

    2013-10-01

    The needle biopsy technique for the soleus muscle is of particular interest because of the muscle's unique fiber type distribution, contractile properties, and sensitivity to unloading. Unlike other commonly biopsied muscles, the soleus is not fully superficial and is in close proximity to neurovascular structures, resulting in a more challenging biopsy. Because of this, a standardized protocol for performing needle biopsies on the human soleus muscle that is safe, reliable, and repeatable is presented. Ultrasonography was used on an initial set of 12 subjects to determine the optimal biopsy zone, thereby guiding the location of the incision site. There were 45 subjects recruited who attended 2 separate biopsy sessions. Each biopsy session incorporated 3 passes of the biopsy needle proximal, posterior, and distal using suction from a portable vacuum source producing 3 separate muscle specimens. There were 84 soleus muscle biopsy procedures which were successfully conducted yielding 252 total samples without complication. Ultrasonography was used to confirm biopsy needle infiltration of the soleus muscle. Average sample weight obtained per pass was 61.5 +/- 15.7 mg. Histochemistry and molecular analyses demonstrated a considerably higher amount of slow type I MHC in comparison to the vastus lateralis, providing verification for the successful sampling of the soleus muscle. The procedure presented consists of a detailed protocol to accurately and consistently obtain muscle biopsy samples from the human soleus muscle. We have demonstrated that the human soleus biopsy is a safe, reliable, and repeatable procedure providing ample tissue for multiple types of analyses.

  14. A long term model of circulation. [human body

    Science.gov (United States)

    White, R. J.

    1974-01-01

    A quantitative approach to modeling human physiological function, with a view toward ultimate application to long duration space flight experiments, was undertaken. Data was obtained on the effect of weightlessness on certain aspects of human physiological function during 1-3 month periods. Modifications in the Guyton model are reviewed. Design considerations for bilateral interface models are discussed. Construction of a functioning whole body model was studied, as well as the testing of the model versus available data.

  15. Dynamic bending of bionic flexible body driven by pneumatic artificial muscles(PAMs) for spinning gait of quadruped robot

    Science.gov (United States)

    Lei, Jingtao; Yu, Huangying; Wang, Tianmiao

    2016-01-01

    The body of quadruped robot is generally developed with the rigid structure. The mobility of quadruped robot depends on the mechanical properties of the body mechanism. It is difficult for quadruped robot with rigid structure to achieve better mobility walking or running in the unstructured environment. A kind of bionic flexible body mechanism for quadruped robot is proposed, which is composed of one bionic spine and four pneumatic artificial muscles(PAMs). This kind of body imitates the four-legged creatures' kinematical structure and physical properties, which has the characteristic of changeable stiffness, lightweight, flexible and better bionics. The kinematics of body bending is derived, and the coordinated movement between the flexible body and legs is analyzed. The relationship between the body bending angle and the PAM length is obtained. The dynamics of the body bending is derived by the floating coordinate method and Lagrangian method, and the driving force of PAM is determined. The experiment of body bending is conducted, and the dynamic bending characteristic of bionic flexible body is evaluated. Experimental results show that the bending angle of the bionic flexible body can reach 18°. An innovation body mechanism for quadruped robot is proposed, which has the characteristic of flexibility and achieve bending by changing gas pressure of PAMs. The coordinated movement of the body and legs can achieve spinning gait in order to improve the mobility of quadruped robot.

  16. An electromyographic evaluation of dual role breathing and upper body muscles in response to front crawl swimming.

    Science.gov (United States)

    Lomax, M; Tasker, L; Bostanci, O

    2015-10-01

    The upper body trunk musculature is key in supporting breathing, propulsion, and stabilization during front crawl swimming. The aim of this study was to determine if the latissimus dorsi, pectoralis major, and serratus anterior contributed to the development of inspiratory muscle fatigue observed following front crawl swimming. Fourteen trained swimmers completed a 200-m front crawl swim at 90% of race pace. Maximal inspiratory and expiratory mouth pressures (PImax and PEmax) were assessed before (baseline) and after each swim, and electromyography was recorded from the three muscles. Post-swim PImax fell by 11% (P inspiratory muscle fatigue was partly caused by fatigue of these muscles, and that breathing frequency and stroke rate particularly affect the serratus anterior.

  17. Heparin inhibits human coronary artery smooth muscle cell migration.

    Science.gov (United States)

    Kohno, M; Yokokawa, K; Yasunari, K; Minami, M; Kano, H; Mandal, A K; Yoshikawa, J

    1998-09-01

    Heparin, an anticoagulant, has been shown to reduce neointimal proliferation and restenosis following vascular injury in experimental studies, but the clinical trials of heparin in coronary balloon angioplasty have been negative. The current study, therefore, examined the effect of heparin on basal or stimulated migration by serum and platelet-derived growth factor (PDGF)-BB in cultured human coronary artery smooth muscle cells (SMCs) by Boyden's chamber method. In addition, the reversibility of the heparin effect on human coronary artery SMC migration was examined. Fetal calf serum (FCS) and PDGF-BB stimulated SMC migration in a concentration-dependent manner. Heparin in moderate to high concentration (10 to 100 U/mL) exhibited concentration-related inhibition of FCS- and PDGF-BB-stimulated SMC migration; however, a low concentration (1 U/mL) of heparin had no inhibitory effects. Heparin also had weak inhibitory effects on nonstimulated SMC migration. The SMCs that were exposed to a high concentration (100 U/mL) of heparin for 6 hours were capable of migrating after a short lag period of removal of heparin from the culture medium. These SMCs also showed recovery of responses to FCS and PDGF-BB by migrating significantly greater than the nonstimulated level. Furthermore, heparin-containing medium did not contain detached cells. These results indicate that heparin inhibits human coronary artery SMC migration, especially when stimulated by FCS or PDGF-BB, and that this inhibitory effect of heparin is reversible and not simply a function of killing cells.

  18. A mathematical high bar-human body model for analysing and interpreting mechanical-energetic processes on the high bar.

    Science.gov (United States)

    Arampatzis, A; Brüggemann, G P

    1998-12-01

    The aims of this study were: 1. To study the transfer of energy between the high bar and the gymnast. 2. To develop criteria from the utilisation of high bar elasticity and the utilisation of muscle capacity to assess the effectiveness of a movement solution. 3. To study the influence of varying segment movement upon release parameters. For these purposes a model of the human body attached to the high bar (high bar-human body model) was developed. The human body was modelled using a 15-segment body system. The joint-beam element method (superelement) was employed for modelling the high bar. A superelement consists of four rigid segments connected by joints (two Cardan joints and one rotational-translational joint) and springs (seven rotation springs and one tension-compression spring). The high bar was modelled using three superelements. The input data required for the high bar human body model were collected with video-kinematographic (50 Hz) and dynamometric (500 Hz) techniques. Masses and moments of inertia of the 15 segments were calculated using the data from the Zatsiorsky et al. (1984) model. There are two major phases characteristic of the giant swing prior to dismounts from the high bar. In the first phase the gymnast attempts to supply energy to the high bar-humanbody system through muscle activity and to store this energy in the high bar. The difference between the energy transferred to the high bar and the reduction in the total energy of the body could be adopted as a criterion for the utilisation of high bar elasticity. The energy previously transferred into the high bar is returned to the body during the second phase. An advantageous increase in total body energy at the end of the exercise could only be obtained through muscle energy supply. An index characterising the utilisation of muscle capacity was developed out of the difference between the increase in total body energy and the energy returned from the high bar. A delayed and initially slow but

  19. Task-dependent spatial distribution of neural activation pattern in human rectus femoris muscle.

    Science.gov (United States)

    Watanabe, Kohei; Kouzaki, Motoki; Moritani, Toshio

    2012-04-01

    Compartmentalization of skeletal muscle by multiple motor nerve branches, named as neuromuscular compartment (NMC), has been demonstrated in animals as well as humans. While different functional roles among individual NMCs were reported in the animal studies, no studies have clarified the region-specific functional role within a muscle related with NMCs arrangement in human skeletal muscle. It was reported that the rectus femoris (RF) muscle is innervated by two nerve branches attached at proximal and distal parts of the muscle. The purpose of the present study is to clarify the possible region-specific functional role in the human RF muscle. Multi-channel surface electromyography (SEMG) were recorded from the RF muscle by using 128 electrodes during two different submaximal isometric contractions that the muscle contributes, i.e. isometric knee extension and hip flexion, at 20%, 40%, 60% and 80% of maximal voluntary contraction (MVC). Results indicated that the central locus activation for the amplitude map of SEMG during hip flexion located at more proximal region compared with that during knee extension. Significant higher normalized root mean square (RMS) values were observed at the proximal region during the hip flexion in comparison to those at middle and distal regions at 60% and 80% of MVC (pMVC (p<0.05). The results of the present study suggest possible region-specific functional role in the human RF muscle.

  20. Human and animal sounds influence recognition of body language.

    Science.gov (United States)

    Van den Stock, Jan; Grèzes, Julie; de Gelder, Beatrice

    2008-11-25

    In naturalistic settings emotional events have multiple correlates and are simultaneously perceived by several sensory systems. Recent studies have shown that recognition of facial expressions is biased towards the emotion expressed by a simultaneously presented emotional expression in the voice even if attention is directed to the face only. So far, no study examined whether this phenomenon also applies to whole body expressions, although there is no obvious reason why this crossmodal influence would be specific for faces. Here we investigated whether perception of emotions expressed in whole body movements is influenced by affective information provided by human and by animal vocalizations. Participants were instructed to attend to the action displayed by the body and to categorize the expressed emotion. The results indicate that recognition of body language is biased towards the emotion expressed by the simultaneously presented auditory information, whether it consist of human or of animal sounds. Our results show that a crossmodal influence from auditory to visual emotional information obtains for whole body video images with the facial expression blanked and includes human as well as animal sounds.

  1. Muscle adiposity and body fat distribution in type 1 and type 2 diabetes: varying relationships according to diabetes type.

    Science.gov (United States)

    Dubé, M C; Joanisse, D R; Prud'homme, D; Lemieux, S; Bouchard, C; Pérusse, L; Lavoie, C; Weisnagel, S J

    2006-12-01

    To compare the relationships between markers of total and regional adiposity with muscle fat infiltration in type 1 diabetic and type 2 diabetic subjects and their respective nondiabetic controls, and to document these relationships in type 1 diabetic subjects. Cross-sectional study. In total, 86 healthy, with type 1 diabetes, type 2 diabetes or control subjects. Each diabetic group was matched for age, sex and body mass index with its respective nondiabetic control group. Measures of body composition (hydrodensitometry), fat distribution (waist circumference, abdominal and mid-thigh computed tomography scans) and blood lipid profiles were assessed. Low attenuation mid-thigh muscle surface correlated similarly with markers of adiposity and body composition in all groups, regardless of diabetes status, except for visceral adipose tissue and waist circumference. Indeed, relationships between visceral adiposity and muscle adiposity were significantly stronger in type 2 vs type 1 diabetic subjects (P<0.05 for comparison of slopes). In addition, in well-controlled type 1 diabetic subjects (mean HbA(1c) of 6.8%), daily insulin requirements tended to correlate with low attenuation mid-thigh muscle surface, a specific component of fat-rich muscle (r=0.36, P=0.08), but not with glycemic control (HbA(1c)). This study suggests that the relationship of central adiposity and muscle adiposity is modulated by diabetes status and is stronger in the insulin resistant diabetes type (type 2 diabetes). In well-controlled nonobese type 1 diabetic subjects, the relationship between muscle fat accumulation and insulin sensitivity was also maintained.

  2. Alterations in Whole-Body Insulin Sensitivity Resulting From Repeated Eccentric Exercise of a Single Muscle Group: A Pilot Investigation.

    Science.gov (United States)

    Gonzalez, Javier T; Barwood, Martin J; Goodall, Stuart; Thomas, Kevin; Howatson, Glyn

    2015-08-01

    Unaccustomed eccentric exercise using large muscle groups elicits soreness, decrements in physical function and impairs markers of whole-body insulin sensitivity; although these effects are attenuated with a repeated exposure. Eccentric exercise of a small muscle group (elbow flexors) displays similar soreness and damage profiles in response to repeated exposure. However, it is unknown whether damage to small muscle groups impacts upon whole-body insulin sensitivity. This pilot investigation aimed to characterize whole-body insulin sensitivity in response to repeated bouts of eccentric exercise of the elbow flexors. Nine healthy males completed two bouts of eccentric exercise separated by 2 weeks. Insulin resistance (updated homeostasis model of insulin resistance, HOMA2-IR) and muscle damage profiles (soreness and physical function) were assessed before, and 48 h after exercise. Matsuda insulin sensitivity indices (ISI Matsuda) were also determined in 6 participants at the same time points as HOMA2-IR. Soreness was elevated, and physical function impaired, by both bouts of exercise (both p Eccentric exercise decreased ISI Matsuda after the first but not the second bout of eccentric exercise (time x bout interaction p Eccentric exercise performed with an isolated upper limb impairs whole-body insulin sensitivity after the first, but not the second, bout.

  3. Whole body 3-methylhistidine production and proteinase activities in porcine muscle after protein-free feeding and realimentation.

    NARCIS (Netherlands)

    Hemel-Grooten, van den H.N.A.; Rathmacher, J.A.; Garssen, G.J.; Schreurs, V.V.A.M.; Verstegen, M.W.A.

    1998-01-01

    Whole body 3-methylhistidine (3MH) production rates and proteinase activities in porcine skeletal muscles were studied during a protein-free feeding period and subsequent realimentation. Out of 54 castrated male pigs (35 kg on day 0), six pigs were slaughtered on day 0, and 48 were randomly divided

  4. Raloxifene and body composition and muscle strength in postmenopausal women: a randomized, double-blind, placebo-controlled trial.

    NARCIS (Netherlands)

    Jacobsen, D.E.; Samson, M.M.; Emmelot-Vonk, M.H.; Verhaar, H.J.

    2010-01-01

    OBJECTIVE: To compare the effects of raloxifene and placebo on body composition and muscle strength. DESIGN: Randomized, double-blind, placebo-controlled trial involving 198 healthy women aged 70 years or older conducted between July 2003 and January 2008 at the University Medical Centre, Utrecht, T

  5. SUPERNORMAL MUSCLE-FIBER CONDUCTION-VELOCITY DURING INTERMITTENT ISOMETRIC-EXERCISE IN HUMAN MUSCLE

    NARCIS (Netherlands)

    VANDERHOEVEN, JH; LANGE, F

    1994-01-01

    Muscle fiber conduction velocity (MFCV) and surface electromyographic parameters were studied in the brachial biceps muscle of healthy males during voluntary intermittent isometric contractions at 50% of maximum force. Recovery in the following 15 min was then observed. The measurements were perform

  6. Provocation of delayed-onset muscle soreness in the human jaw-closing muscles

    NARCIS (Netherlands)

    Türker, K.S.; Koutris, M.; Sümer, N.C.; Atis, E.S.; Linke, I.R.; Lobbezoo, F.; Naeije, M.

    2010-01-01

    Eccentric contractions of jaw-closing muscles are difficult to perform. This may explain why fatigue-inducing experiments performed so far suggest the jaw-closing muscles to be fatigue resistant. Aim of this study was to construct an apparatus that can impose intense eccentric contractions to the ja

  7. Muscles within muscles: a tensiomyographic and histochemical analysis of the normal human vastus medialis longus and vastus medialis obliquus muscles.

    Science.gov (United States)

    Travnik, Ludvik; Djordjevič, Srdjan; Rozman, Sergej; Hribernik, Marija; Dahmane, Raja

    2013-06-01

    The aim of this study was to show the connection between structure (anatomical and histochemical) and function (muscle contraction properties) of vastus medialis obliquus (VMO) and vastus medialis longus (VML). The non-invasive tensiomyography (TMG) method was used to determine the contractile properties (contraction time; T(c)) of VML and VMO muscle, as a reflection of the ratio between the slow and fast fibers in two groups of nine young men. VML and VMO significantly (P knee, and to the VMO, which maintains the stable position of the patella in the femoral groove. Our results obtained by TMG provided additional evidence that muscle fibers within the segments of VM muscle were not homogenous with regard to their contractile properties, thereby confirming the histochemical results. T(c) can be attributed to the higher percentage of slow-twitch fibers - type 1. The statistically shorter T(c) (P ≤ 0.001) of VMO (22.8 ± 4.0 ms) compared with VML (26.7 ± 4.0 ms) in our study is consistent with previously found differences in histochemical, morphological and electrophysiological data. In conclusion, the results of this study provide evidence that the VML and VMO muscles are not only anatomically and histochemically different muscles, but also functionally different biological structures.

  8. Alterations to mTORC1 signaling in the skeletal muscle differentially affect whole-body metabolism.

    Science.gov (United States)

    Guridi, Maitea; Kupr, Barbara; Romanino, Klaas; Lin, Shuo; Falcetta, Denis; Tintignac, Lionel; Rüegg, Markus A

    2016-01-01

    The mammalian target of rapamycin complex 1 (mTORC1) is a central node in a network of signaling pathways controlling cell growth and survival. This multiprotein complex integrates external signals and affects different nutrient pathways in various organs. However, it is not clear how alterations of mTORC1 signaling in skeletal muscle affect whole-body metabolism. We characterized the metabolic phenotype of young and old raptor muscle knock-out (RAmKO) and TSC1 muscle knock-out (TSCmKO) mice, where mTORC1 activity in skeletal muscle is inhibited or constitutively activated, respectively. Ten-week-old RAmKO mice are lean and insulin resistant with increased energy expenditure, and they are resistant to a high-fat diet (HFD). This correlates with an increased expression of histone deacetylases (HDACs) and a downregulation of genes involved in glucose and fatty acid metabolism. Ten-week-old TSCmKO mice are also lean, glucose intolerant with a decreased activation of protein kinase B (Akt/PKB) targets that regulate glucose transporters in the muscle. The mice are resistant to a HFD and show reduced accumulation of glycogen and lipids in the liver. Both mouse models suffer from a myopathy with age, with reduced fat and lean mass, and both RAmKO and TSCmKO mice develop insulin resistance and increased intramyocellular lipid content. Our study shows that alterations of mTORC1 signaling in the skeletal muscle differentially affect whole-body metabolism. While both inhibition and constitutive activation of mTORC1 induce leanness and resistance to obesity, changes in the metabolism of muscle and peripheral organs are distinct. These results indicate that a balanced mTORC1 signaling in the muscle is required for proper metabolic homeostasis.

  9. Low muscle glycogen and elevated plasma free fatty acid modify but do not prevent exercise-induced PDH activation in human skeletal muscle

    DEFF Research Database (Denmark)

    Kiilerich, Kristian; Gudmundsson, Mikkel; Birk, Jesper Bratz;

    2010-01-01

    Objective: Test the hypothesis that FFA and muscle glycogen modify exercise-induced regulation of PDH in human skeletal muscle through regulation of PDK4 expression. Research Design and Methods: On two occasions, healthy male subjects lowered (by exercise) muscle glycogen in one leg (LOW) relativ...

  10. Fusion of Multiple Pyroelectric Characteristics for Human Body Identification

    Directory of Open Access Journals (Sweden)

    Wanchun Zhou

    2014-12-01

    Full Text Available Due to instability and poor identification ability of single pyroelectric infrared (PIR detector for human target identification, this paper proposes a new approach to fuse the information collected from multiple PIR sensors for human identification. Firstly, Fast Fourier Transform (FFT, Short Time Fourier Transform (STFT, Wavelet Transform (WT and Wavelet Packet Transform (WPT are adopted to extract features of the human body, which can be achieved by single PIR sensor. Then, we apply Principal Component Analysis (PCA and Support Vector Machine (SVM to reduce the characteristic dimensions and to classify the human targets, respectively. Finally, Fuzzy Comprehensive Evaluation (FCE is utilized to fuse recognition results from multiple PIR sensors to finalize human identification. The pyroelectric characteristics under scenarios with different people and/or different paths are analyzed by various experiments, and the recognition results with/without fusion procedure are also shown and compared. The experimental results demonstrate our scheme has improved efficiency for human identification.

  11. Effects of muscle activation on shear between human soleus and gastrocnemius muscles.

    Science.gov (United States)

    Finni, T; Cronin, N J; Mayfield, D; Lichtwark, G A; Cresswell, A G

    2017-01-01

    Lateral connections between muscles provide pathways for myofascial force transmission. To elucidate whether these pathways have functional roles in vivo, we examined whether activation could alter the shear between the soleus (SOL) and lateral gastrocnemius (LG) muscles. We hypothesized that selective activation of LG would decrease the stretch-induced shear between LG and SOL. Eleven volunteers underwent a series of knee joint manipulations where plantar flexion force, LG, and SOL muscle fascicle lengths and relative displacement of aponeuroses between the muscles were obtained. Data during a passive full range of motion were recorded, followed by 20° knee extension stretches in both passive conditions and with selective electrical stimulation of LG. During active stretch, plantar flexion force was 22% greater (P muscles, at least at flexed knee joint angles, which may serve to facilitate myofascial force transmission. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  12. Exceptional evolutionary divergence of human muscle and brain metabolomes parallels human cognitive and physical uniqueness

    DEFF Research Database (Denmark)

    Bozek, Katarzyna; Wei, Yuning; Yan, Zheng;

    2014-01-01

    Metabolite concentrations reflect the physiological states of tissues and cells. However, the role of metabolic changes in species evolution is currently unknown. Here, we present a study of metabolome evolution conducted in three brain regions and two non-neural tissues from humans, chimpanzees......, macaque monkeys, and mice based on over 10,000 hydrophilic compounds. While chimpanzee, macaque, and mouse metabolomes diverge following the genetic distances among species, we detect remarkable acceleration of metabolome evolution in human prefrontal cortex and skeletal muscle affecting neural and energy...

  13. Medical Sequencing at the extremes of Human Body Mass

    Energy Technology Data Exchange (ETDEWEB)

    Ahituv, Nadav; Kavaslar, Nihan; Schackwitz, Wendy; Ustaszewski,Anna; Martin, Joes; Hebert, Sybil; Doelle, Heather; Ersoy, Baran; Kryukov, Gregory; Schmidt, Steffen; Yosef, Nir; Ruppin, Eytan; Sharan,Roded; Vaisse, Christian; Sunyaev, Shamil; Dent, Robert; Cohen, Jonathan; McPherson, Ruth; Pennacchio, Len A.

    2006-09-01

    Body weight is a quantitative trait with significantheritability in humans. To identify potential genetic contributors tothis phenotype, we resequenced the coding exons and splice junctions of58 genes in 379 obese and 378 lean individuals. Our 96Mb survey included21 genes associated with monogenic forms of obesity in humans or mice, aswell as 37 genes that function in body weight-related pathways. We foundthat the monogenic obesity-associated gene group was enriched for rarenonsynonymous variants unique to the obese (n=46) versus lean (n=26)populations. Computational analysis further predicted a significantlygreater fraction of deleterious variants within the obese cohort.Consistent with the complex inheritance of body weight, we did notobserve obvious familial segregation in the majority of the 28 availablekindreds. Taken together, these data suggest that multiple rare alleleswith variable penetrance contribute to obesity in the population andprovide a deep medical sequencing based approach to detectthem.

  14. Intellectual property rights and detached human body parts.

    Science.gov (United States)

    Pila, Justine

    2014-01-01

    This paper responds to an invitation by the editors to consider whether the intellectual property (IP) regime suggests an appropriate model for protecting interests in detached human body parts. It begins by outlining the extent of existing IP protection for body parts in Europe, and the relevant strengths and weaknesses of the patent system in that regard. It then considers two further species of IP right of less obvious relevance. The first are the statutory rights of ownership conferred by domestic UK law in respect of employee inventions, and the second are the economic and moral rights recognised by European and international law in respect of authorial works. In the argument made, both of these species of IP right may suggest more appropriate models of sui generis protection for detached human body parts than patent rights because of their capacity better to accommodate the relevant public and private interests in respect of the same.

  15. A low power wearable transceiver for human body communication.

    Science.gov (United States)

    Huang, Jin; Chen, Lian-Kang; Zhang, Yuan-Ting

    2009-01-01

    This paper reports a low power transceiver designed for wearable medical healthcare system. Based on a novel energy-efficient wideband wireless communication scheme that uses human body as a transmission medium, the transceiver can achieve a maximum 15 Mbps data rate with total receiver sensitivity of -30 dBm. The chip measures only 0.56 mm(2) and was fabricated in the SMIC 0.18um 1P6M RF CMOS process. The RX consumes 5mW and TX dissipates 1mW with delivering power up to 10uW, which is suitable for the body area network short range application. Real-time medical information collecting through the human body is fully simulated. Architecture of the chip together with the detail characterizes from its wireless analog front-end are presented.

  16. Mechanism of toppling instability of the human body in floodwaters

    Science.gov (United States)

    Shu, C. W.; Han, S. S.; Kong, W. N.; Dong, B. L.

    2016-08-01

    Extreme urban flood events occur frequently in China, often leading to heavy casualties. Thus, it is of great importance to study the mechanism of the instability of the human body in floodwaters. The results of such research can provide scientific reference for city flood control standards. In this paper, a formula for the incipient velocity of the human body, during toppling instability in floodwaters, was derived based on mechanical characteristics, instability mechanism, and critical conditions during instability. A series of flume experiments were conducted to investigate the incipient velocity of two 3D printed human body models of different sizes; the resultant experimental data was used to determine parameters in the derived formula. Additionally, grip strength was taken as a standard of a person's ability to withstand floodwaters. Finally, crowd factors were introduced, and based on this study, a criterion for the toppling instability of different subjects in floodwaters was proposed. Compared to the results of previous studies, the proposed formula can better predict the instability of the human body in floodwaters.

  17. Language Functions and Medical Communication: The Human Body as Text

    Science.gov (United States)

    Kantz, Deirdre; Marenzi, Ivana

    2016-01-01

    This article presents the findings of a field experiment in medical English with first-year medical students at the University of Pavia, Northern Italy. Working in groups of 8-10, the students were asked to produce a corpus of medical texts in English demonstrating how the human body is itself a meaningful text (Baldry and Thibault 2006: Ch. 1).…

  18. Of Human Bodies in Scientific Communication and Enculturation

    Science.gov (United States)

    Hwang, SungWon; Roth, Wolff-Michael

    2008-01-01

    How do students become enculturated and come to enact culture in ways that are new to them? This study probes the dialectical processes of enculturation, the central aspect of which is the role of human bodies in communication. For students, as for any individual, culture exists in terms of action possibilities that presuppose their…

  19. Scanning 3D full human bodies using Kinects.

    Science.gov (United States)

    Tong, Jing; Zhou, Jin; Liu, Ligang; Pan, Zhigeng; Yan, Hao

    2012-04-01

    Depth camera such as Microsoft Kinect, is much cheaper than conventional 3D scanning devices, and thus it can be acquired for everyday users easily. However, the depth data captured by Kinect over a certain distance is of extreme low quality. In this paper, we present a novel scanning system for capturing 3D full human body models by using multiple Kinects. To avoid the interference phenomena, we use two Kinects to capture the upper part and lower part of a human body respectively without overlapping region. A third Kinect is used to capture the middle part of the human body from the opposite direction. We propose a practical approach for registering the various body parts of different views under non-rigid deformation. First, a rough mesh template is constructed and used to deform successive frames pairwisely. Second, global alignment is performed to distribute errors in the deformation space, which can solve the loop closure problem efficiently. Misalignment caused by complex occlusion can also be handled reasonably by our global alignment algorithm. The experimental results have shown the efficiency and applicability of our system. Our system obtains impressive results in a few minutes with low price devices, thus is practically useful for generating personalized avatars for everyday users. Our system has been used for 3D human animation and virtual try on, and can further facilitate a range of home–oriented virtual reality (VR) applications.

  20. Students' Conceptions about Energy and the Human Body

    Science.gov (United States)

    Mann, Michael; Treagust, David F.

    2010-01-01

    Students' understanding of energy has been primarily within the domain of physics. This study sought to examine students' understanding of concepts relating to energy and the human body using pencil and paper questionnaires administered to 610 students in Years 8-12. From students' responses to the questionnaires, conceptual patterns were…

  1. Science Teachers' Drawings of What Is inside the Human Body

    Science.gov (United States)

    Patrick, Patricia G.; Tunnicliffe, Sue Dale

    2010-01-01

    The purpose of this study was to report United States of America (USA) science teachers' understandings of the internal structures of the human body. The 71 science teachers who participated in this study attended a frog/pig, two-hour dissection workshop at the 2004 National Science Teachers Association (NSTA) conference in Atlanta, Georgia. The…

  2. Attenuation of skeletal muscle wasting with recombinant human growth hormone secreted from a tissue-engineered bioartificial muscle

    Science.gov (United States)

    Vandenburgh, H.; Del Tatto, M.; Shansky, J.; Goldstein, L.; Russell, K.; Genes, N.; Chromiak, J.; Yamada, S.

    1998-01-01

    Skeletal muscle wasting is a significant problem in elderly and debilitated patients. Growth hormone (GH) is an anabolic growth factor for skeletal muscle but is difficult to deliver in a therapeutic manner by injection owing to its in vivo instability. A novel method is presented for the sustained secretion of recombinant human GH (rhGH) from genetically modified skeletal muscle implants, which reduces host muscle wasting. Proliferating murine C2C12 skeletal myoblasts stably transduced with the rhGH gene were tissue engineered in vitro into bioartificial muscles (C2-BAMs) containing organized postmitotic myofibers secreting 3-5 microg of rhGH/day in vitro. When implanted subcutaneously into syngeneic mice, C2-BAMs delivered a sustained physiologic dose of 2.5 to 11.3 ng of rhGH per milliliter of serum. rhGH synthesized and secreted by the myofibers was in the 22-kDa monomeric form and was biologically active, based on downregulation of a GH-sensitive protein synthesized in the liver. Skeletal muscle disuse atrophy was induced in mice by hindlimb unloading, causing the fast plantaris and slow soleus muscles to atrophy by 21 to 35% ( < 0.02). This atrophy was significantly attenuated 41 to 55% (p < 0.02) in animals that received C2-BAM implants, but not in animals receiving daily injections of purified rhGH (1 mg/kg/day). These data support the concept that delivery of rhGH from BAMs may be efficacious in treating muscle-wasting disorders.

  3. Functional Compartmentalization of the Human Superficial Masseter Muscle

    OpenAIRE

    Guzmán-Venegas, Rodrigo A.; Biotti Picand, Jorge L.; Francisco J Berral de la Rosa

    2015-01-01

    Some muscles have demonstrated a differential recruitment of their motor units in relation to their location and the nature of the motor task performed; this involves functional compartmentalization. There is little evidence that demonstrates the presence of a compartmentalization of the superficial masseter muscle during biting. The aim of this study was to describe the topographic distribution of the activity of the superficial masseter (SM) muscle's motor units using high-density surface e...

  4. Mechanical impedance of the human body in vertical direction.

    Science.gov (United States)

    Holmlund, P; Lundström, R; Lindberg, L

    2000-08-01

    The mechanical impedance of the human body in sitting posture and vertical direction was measured during different experimental conditions, such as vibration level (0.5-1.4 m/s2), frequency (2-100 Hz), body weight (57-92 kg), relaxed and erect upper body posture. The outcome shows that impedance increases with frequency up to a peak at about 5 Hz after which it decreases in a complex manner which includes two additional peaks. The frequency at which the first and second impedance peak occurs decreases with higher vibration level. Erect, compared with relaxed body posture resulted in higher impedance magnitudes and with peaks located at somewhat higher frequencies. Heavy persons show higher impedance magnitudes and peaks at lower frequencies.

  5. [Mechanism of heat transfer in various regions of human body].

    Science.gov (United States)

    Luchakov, Iu I; Nozdrachev, A D

    2009-01-01

    The processes of heat transfer in a human body were studied with the use of a mathematical model. It has been shown that only conductive or only convective heat transfer may occur in different body areas. The rate of blood-mediated heat transfer in the presence of blood circulation is many times higher than heat transfer due to temperature gradient; therefore, the convective process prevails over the conductive process. The body core contains a variety of blood vessels, and the bulk of blood concentrates there in the norm. Hence, heat transfer in it is mainly convective. In surface tissues, where the rate of blood circulation is lower and the vasculature has certain specific features, heat transfer is mainly conductive. Hence, the core and surface tissues are absolutely different body zones in terms of heat transfer.

  6. Combined volatolomics for monitoring of human body chemistry.

    Science.gov (United States)

    Broza, Yoav Y; Zuri, Liat; Haick, Hossam

    2014-04-09

    Analysis of volatile organic compounds (VOCs) is a promising approach for non-invasive, fast and potentially inexpensive diagnostics. Here, we present a new methodology for profiling the body chemistry by using the volatile fraction of molecules in various body fluids. Using mass spectrometry and cross-reactive nanomaterial-based sensors array, we demonstrate that simultaneous VOC detection from breath and skin would provide complementary, non-correlated information of the body's volatile metabolites profile. Eventually with further wide population validation studies, such a methodology could provide more accurate monitoring of pathological changes compared to the information provided by a single body fluid. The qualitative and quantitative methods presented here offers a variety of options for novel mapping of the metabolic properties of complex organisms, including humans.

  7. Functional Echomyography of the human denervated muscle: first results

    Directory of Open Access Journals (Sweden)

    Riccardo Zanato

    2011-03-01

    Full Text Available In this study we followed with ultrasound three patients with permanent denervation to evaluate changes in morphology, thickness, contraction and vascularisation of muscles undergoing the home-based electrical stimulation program of the Rise2-Italy project. During a period of 1 year for the first subject, 6 months for the second subject and 3 months for the third subject we studied with ultrasound the denervated muscle comparing it (if possible to the contralateral normal muscle. We evaluated: 1. Changes in morphology and sonographic structure of the pathologic muscle; 2. Muscular thickness in response to the electrical stimulation therapy; 3. Short-term modifications in muscle perfusion and arterial flow patterns after stimulation; 4. Contraction-relaxation kinetic induced by volitional activity or electrical stimulation. Morphology and ultrasonographic structure of the denervated muscles changed during the period of stimulation from a pattern typical of complete muscular atrophy to a pattern which might be considered “normal” when detected in an old patient. Thickness improved significantly more in the middle third than in the proximal and distal third of the denervated muscle, reaching in the last measurements of the first subject approximately the same thickness as the contralateral normal muscle. In all the measurements done within this study, arterial flow of the denervated muscle showed at rest a low-resistance pattern with Doppler Ultra Sound (US, and a pulsed pattern after electrical stimulation. The stimulation- induced pattern is similar to the trifasic high-resistance pattern of the normal muscle. Contraction- relaxation kinetic, measured by recording the muscular movements during electrical stimulation, showed an abnormal behaviour of the denervated muscle during the relaxation phase, which resulted to be significantly longer than in normal muscle (880 msec in the denervated muscle vs 240 msec in the contralateral normal one

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

    Directory of Open Access Journals (Sweden)

    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. Robot and Human Surface Operations on Solar System Bodies

    Science.gov (United States)

    Weisbin, C. R.; Easter, R.; Rodriguez, G.

    2001-01-01

    This paper presents a comparison of robot and human surface operations on solar system bodies. The topics include: 1) Long Range Vision of Surface Scenarios; 2) Human and Robots Complement Each Other; 3) Respective Human and Robot Strengths; 4) Need More In-Depth Quantitative Analysis; 5) Projected Study Objectives; 6) Analysis Process Summary; 7) Mission Scenarios Decompose into Primitive Tasks; 7) Features of the Projected Analysis Approach; and 8) The "Getting There Effect" is a Major Consideration. This paper is in viewgraph form.

  10. Silk fibroin scaffolds with muscle-like elasticity support in vitro differentiation of human skeletal muscle cells.

    Science.gov (United States)

    Chaturvedi, Vishal; Naskar, Deboki; Kinnear, Beverley F; Grenik, Elizabeth; Dye, Danielle E; Grounds, Miranda D; Kundu, Subhas C; Coombe, Deirdre R

    2016-11-22

    Human adult skeletal muscle has a limited ability to regenerate after injury and therapeutic options for volumetric muscle loss are few. Technologies to enhance regeneration of tissues generally rely upon bioscaffolds to mimic aspects of the tissue extracellular matrix (ECM). In the present study, silk fibroins from four Lepidoptera (silkworm) species engineered into three-dimensional scaffolds were examined for their ability to support the differentiation of primary human skeletal muscle myoblasts. Human skeletal muscle myoblasts (HSMMs) adhered, spread and deposited extensive ECM on all the scaffolds, but immunofluorescence and quantitative polymerase chain reaction analysis of gene expression revealed that myotube formation occurred differently on the various scaffolds. Bombyx mori fibroin scaffolds supported formation of long, well-aligned myotubes, whereas on Antheraea mylitta fibroin scaffolds the myotubes were thicker and shorter. Myotubes were oriented in two perpendicular layers on Antheraea assamensis scaffolds, and scaffolds of Philosamia/Samia ricini (S. ricini) fibroin poorly supported myotube formation. These differences were not caused by fibroin composition per se, as HSMMs adhered to, proliferated on and formed striated myotubes on all four fibroins presented as two-dimensional fibroin films. The Young's modulus of A. mylitta and B. mori scaffolds mimicked that of normal skeletal muscle, but A. assamensis and S. ricini scaffolds were more flexible. The present study demonstrates that although myoblasts deposit matrix onto fibroin scaffolds and create a permissive environment for cell proliferation, a scaffold elasticity resembling that of normal muscle is required for optimal myotube length, alignment, and maturation. © 2016 The Authors Journal of Tissue Engineering and Regenerative Medicine Published by John Wiley & Sons Ltd. © 2016 The Authors Journal of Tissue Engineering and Regenerative Medicine Published by John Wiley & Sons Ltd.

  11. Parameter estimation of the Huxley cross-bridge muscle model in humans.

    Science.gov (United States)

    Vardy, Alistair N; de Vlugt, Erwin; van der Helm, Frans C T

    2012-01-01

    The Huxley model has the potential to provide more accurate muscle dynamics while affording a physiological interpretation at cross-bridge level. By perturbing the wrist at different velocities and initial force levels, reliable Huxley model parameters were estimated in humans in vivo using a Huxley muscle-tendon complex. We conclude that these estimates may be used to investigate and monitor changes in microscopic elements of muscle functioning from experiments at joint level.

  12. Aging affects the transcriptional regulation of human skeletal muscle disuse atrophy.

    Directory of Open Access Journals (Sweden)

    Charlotte Suetta

    Full Text Available Important insights concerning the molecular basis of skeletal muscle disuse-atrophy and aging related muscle loss have been obtained in cell culture and animal models, but these regulatory signaling pathways have not previously been studied in aging human muscle. In the present study, muscle atrophy was induced by immobilization in healthy old and young individuals to study the time-course and transcriptional factors underlying human skeletal muscle atrophy. The results reveal that irrespectively of age, mRNA expression levels of MuRF-1 and Atrogin-1 increased in the very initial phase (2-4 days of human disuse-muscle atrophy along with a marked reduction in PGC-1α a