Top PDF Method for measuring muscle mass

Method for measuring muscle mass

Method for measuring muscle mass

A method for determining muscle mass in a human subject useful for monitoring athletic conditioning, weight loss programs, nutritional deficiencies, and disease states which cause muscle wasting is provided comprising administration of a bolus dose of a metabolic marker for 3-methylhistidine, the use of a three- compartment model to describe data from blood samples collected periodically thereafter, and calculation of muscle mass as a function of specific values generated by the model.

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Electrical muscle stimulation preserves the muscle mass of critically ill patients: a randomized study

Electrical muscle stimulation preserves the muscle mass of critically ill patients: a randomized study

This study aimed to assess the role of EMS for the preserva- tion of muscle mass. Although the role of physical, occupa- tional and mobility therapy has been increased in recent years [40,41], EMS is an alternative method of exercise causing min- imal discomfort to patients who are not able to perform any form of physical exercise, as is often the case in critically ill patients. Functional evaluation and muscle strength would have been the most appropriate endpoints in our study. How- ever, functional and muscle strength evaluation requires patient cooperation, which was not feasible for the majority of critically ill patients on the seventh or eighth day after admis- sion. It is a limitation of this study that it did not evaluate the effect of EMS on the functional recovery or the muscle strength of critically ill patients, which would have been clini- cally significant endpoints. Further studies are needed to explore the possible role of EMS as a tool for preserving the muscle strength, the muscle properties and preventing CIPNM in critically ill patients and to define which patients would benefit most from this intervention.
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Comparisons between different techniques for measuring mass segregation

Comparisons between different techniques for measuring mass segregation

In this Section we run our four methods for quanti- fying mass segregation on a synthetic dataset containing N = 300 stars to match the small-N statistics of many young regions. We distribute the stars in a fractal distribu- tion according to the prescription in Goodwin & Whitworth (2004), Allison et al. (2010) and Parker et al. (2014). We refer the reader to those papers for a detailed description of how the fractal is set up, but we briefly summarise the method here. The fractal is built by creating a cube con- taining ‘parents’, which spawn a number of ‘children’ de- pending on the desired fractal dimension, D. The amount of substructure is then set by the number of children that are allowed to mature (the lower the fractal dimension, the fewer children mature and the cube has more substructure). We choose a fractal distribution because the Λ MSR ,
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A CFD and experimental investigation into a non intrusive method for measuring cooling air mass flow rate through a synchronous generator

A CFD and experimental investigation into a non intrusive method for measuring cooling air mass flow rate through a synchronous generator

This paper presents a detailed methodology for a non-intrusive measurement of cooling air mass flow rate that enables an overall machine evaluation. This approach enables the simultaneous measurement of air mass flow with shaft torque at differing operating points, while minimising the change in air flow introduced by the measurement system. The impact of geometric parameters in the designed system are investigated using a detailed 180° CFD model. Special attention was paid to minimising their influence on pressure drop, mass flow rate through the machine and measurement uncertainty. Based on the results of this investigation, the system was designed and manufactured and the experimentally measured data was used to validate the CFD predictions. For the as optimal identified configuration, the flow rate is predicted to decrease by 2.2 % relative to unrestricted operation. The achieved measurement uncertainty is ±2.6 % at synchronous speed.
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Muscle strength and its relationship with skeletal muscle mass indices as determined by segmental bio-impedance analysis

Muscle strength and its relationship with skeletal muscle mass indices as determined by segmental bio-impedance analysis

Muscle function, athletic profiles, or functional movement performance assessed by muscle strength are likely to be confounded by the effect of body or limb muscle mass indicating the importance of using body-size-independent indices of muscle strength. However, there is no consensus on the method by which strength measurements are best normalized, and as a result, conventional normalization to different measures of body size has been applied by different studies. 10,13,17,19 Bazett-Jones et al 17 examined various normalisation methods for the hip strength and described force normalization to body mass as the most effective body-size- independent measure. In a study of shoulder rotation strength, Hurd et al 18 compared normalization techniques using a spectrum of anthropometric parameters and reported the body weight as the most effective parameter for strength normalisation.
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Assessment of lower extremity muscle mass, muscle strength, and exercise therapy in elderly patients with diabetes mellitus

Assessment of lower extremity muscle mass, muscle strength, and exercise therapy in elderly patients with diabetes mellitus

Muscle mass is used in diagnosing sarcopenia. Computed tomography (CT) scanning and magnetic resonance im- aging (MRI) permit accurate differentiation of the bone, fat, and lean body tissue and are gold standards for muscle mass evaluation [5]. However, these methods require large, expensive, and nonportable equipment, and there- fore, there are limitations to their use in routine clinical practice. On the other hand, dual-energy X-ray absorpti- ometry (DXA) results in low radiation exposure among patients. The Health ABC study reported that participants were assessed using DXA and were classified as sarcope- nic using two different approaches of adjusting lean mass to body size: appendicular lean mass divided by height squared and appendicular lean mass adjusted for height and body fat mass (residuals) [41]. In addition, the cutoff values of skeletal muscle mass index by DXA (appendicu- lar skeletal muscle mass index (kg)/body height (m) 2 ) were 7.23 kg/m 2 for men and 5.67 kg/m 2 for women. Unfortunately, DXA is also a nonportable equipment. Another method used is bioelectrical impedance analysis (BIA), which measures fat mass and lean body mass. Although the reliability of BIA is somewhat compromised in patients with a BMI of ≥ 35 kg/m 2 , it is a relatively inexpensive and portable alternative to DXA for accurate evaluation of body composition [42]. A working group in Asia reported diagnostic criteria for sarcopenia for Asians in 2015, and the cutoff values for muscle mass measured by BIA were reported [43]. The cutoff values for BIA were 7.0 and 5.7 kg/m 2 for men and women, respectively. However, no standardized diagnostic criteria are available for sarcopenia, and results differ depending on the diagnostic criteria used.
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Test of Pressure Transducer for Measuring Cotton-Mass Flow

Test of Pressure Transducer for Measuring Cotton-Mass Flow

Cotton-Picker Tests. The apparatus consisted of a two-row John Deere cotton picker (Model 9930; John Deere, Des Moines, IA), a conveyor belt, an Omega differential pressure transducer, Model PX653-05D5V (Omega Technology Company, Stamford, CT), a National Instruments card (Model DAQ Card-1200, Austin, TX), an IBM computer, a Psychron psychrometer (Model No. 566, Belfort Instruments, Baltimore, MD), a weighing scale (1 g accuracy), tape measure, and a stop watch. An Omega differential pressure transducer was used for the cotton-picker tests because of failure of the Baratron pressure transducer. Its calibration was verified using the same method used to calibrate the Baratron pres- sure transducer. The transducer output port was con- nected by a plastic tube to the 6-mm diameter picker blockage monitor tap. The picker blockage monitor was a pressure tap on the cotton-picker conveying duct that indicated when plugging occurred.
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Pitfalls in the measurement of muscle mass: a need for a reference standard

Pitfalls in the measurement of muscle mass: a need for a reference standard

the working group were asked to prepare a literature review on the role of lean mass measurement in the assessment of sarcopenia (M.C.), the measurement of Lean Body Mass with DXA (M.V. and K.E.), with bioimpedance (S.M.), and with emerging techniques (R.F.). The topic ‘ how to produce refer- ence standards for the assessment of Lean Body Mass ’ was also discussed (E.D.). Each member prepared a list of the most important papers based on their literature search and made a set of preliminary recommendations. For each item, a complete literature search was performed to identify new or additional randomized controlled trials and systematic reviews/meta-analysis, if any, not used in the existing guide- lines. The MEDLINE (pubmed) database was searched using the name of each technique for measuring body composition as a search term, together ‘ with lean body mass ’ , limiting re- sults to ‘ humans ’ , ‘ randomized controlled trials ’ , ‘ meta- analysis ’ , ‘ systematic reviews ’ , and ‘ guidelines ’ . A similar search was adapted for the Embase database, and each item was also searched in the Cochrane Database of systematic re- views. The reference list of relevant retrieved articles was hand-searched for additional resources when member of the working group were interrogated for their knowledge on articles or congress abstract in press. A free web search was also performed and considered. Searches were per- formed from the year 2000 and updated until September 2016, with the additional evidence constantly provided to the working group members for selection of the best evi- dence according to the panel.
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Real Time Muscle Deformations Using Mass-Spring Systems

Real Time Muscle Deformations Using Mass-Spring Systems

In this paper we propose a method to simulate muscle deformation in real-time, still aiming at satisfying visual results; that is, we are not attempting perfect simulation, but building a useful tool for interactive applications. Muscles are represented at 2 levels: the action lines and the muscle shape. The action line represents the force produced by a muscle on the bones, while the muscle shapes used in the simulation consist of a surface based model fitted to the boundary of medical image data. The algorithm to model muscle shapes is described. To physically simulate deformations, we used a mass-spring system with a new kind of springs called “angular springs” which were developed to control the muscle volume during simulation. Results are presented as examples at the end of the paper.
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Usefulness of circuit training at home for improving bone mass and muscle mass while losing fat mass in undergraduate female students

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

There are several limitations associated with this study. First, I used an ultrasound bone densitometer, a low-invasive technique, to measure the calcaneus QUS- SOS instead of a DXA scan (the preferred technique for measuring the BMD) because the participants were rela- tively young. Second, the sample size was relatively small. Further research will be needed to confirm how to gain greater bone mass and muscle mass while losing fat mass; the effectiveness of circuit training for improv- ing the calcaneus QUS status, such as QUS-SI, QUS- SOS, and QUS-BUA, as well as building muscle mass in young females. Third, studies involving both sexes may be needed to clarify the sex-based differences in the effect of such exercise on the calcaneus QUS status.
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Novel method for measuring induction rates

Novel method for measuring induction rates

discrepancy, but the most likely is the flow restriction that occurs under all flow conditions in the conduit. The results presented for the circular outlets in figure 7 show a clear trend of higher nominal induction rates for reducing nozzle size. For the smallest nozzle, the mass flow rate through the device is the smallest and hence the flow restriction is also the smallest. The effect of outlets geometry has also been presented in the paper and the results clearly show that the shape of the cross section of the outlet has very little or no effect on the induction ratio. The diameter ratio of the nozzle and the outlet can be clearly be extended to cover other shapes when the square root ratio of the outlet and nozzle area are used as proposed in equation 5.
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The impact of muscle function, muscle mass and sarcopenia on independent ageing in very old Swedish men

The impact of muscle function, muscle mass and sarcopenia on independent ageing in very old Swedish men

In conclusion, muscle function, but not muscle mass, was associated with independent ageing in very old men. When using the updated EWGSOP2 defin- ition, severe, but not probable or confirmed sarcope- nia, was associated with loss of independent ageing. Otherwise, none of the present definitions of sarcope- nia according to EWGSOP were associated with inde- pendent ageing. Measuring GS, HGS and CST is easy and possible to do in the clinical setting. Those assessments may identify individuals who can benefit from interventions that might at least postpone the loss of independence. However, further studies are needed to identify these possible interventions.
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Muscle strength and its relationship with skeletal muscle mass indices as determined by segmental bio-impedance analysis

Muscle strength and its relationship with skeletal muscle mass indices as determined by segmental bio-impedance analysis

The utility of sophisticated imaging techniques for estimating muscle size, such as muscle anatomical cross- sectional area and muscle physiological cross-sectional area, is limited by the availability of magnetic resonance imaging (MRI) or computed tomography (CT) equipment. A cheaper and readily available technique would therefore be desirable. Bio-impedance analysis (BIA) is a safe, non-invasive and convenient technique, originally developed to measure whole body composition using a simple electrode configuration between right wrist and leg. State-of-the-art multiple frequency BIA systems, together with recent developments in electrode configurations and analysis software, backed up with comprehensive validation studies against MRI, ultrasound (US), CT, and dual-energy X-ray absorptiometry, have established BIA as a reliable method for the measurement of segmental body composition (Miyatani et al. 2000; Miyatani et al. 2001; Shafer et al. 2009; Salinari et al. 2002; Janssen et al. 2000a; Ishiguro et al. 2006; Chien et al. 2008). Segmental BIA estimates the impedance of body segments (e.g. arm, torso, upper arm, lower arm), from which their segmental composition can be calculated.
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Reliability of diagnostic ultrasound in measuring the multifidus muscle

Reliability of diagnostic ultrasound in measuring the multifidus muscle

Methods: From January 2012 to December 2012 an inter- and intra-examiner reliability study was carried out in a clinical setting. It consisted of a total of four experiments with 30 subjects in each study. Two experienced examiners performed all measurements. Ultrasound measurements were made of: 1. the LMM in the resting state, 2. during a contracted state, 3. on subsequent days, and, before and after walking. Reliability and agreement was tested for 1. resting LMM, 2. contracted LMM, and 3. thickness change in the LMM. Mean values of three measurements were used for statistical analysis for each spinal level. The intra-class correlation coefficient (ICC) 3.1 and 3.2 was used to test for reliability, and Bland-Altman ’ s LOA method to test for agreement.
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A method for measuring electrical signals in a primary cilium

A method for measuring electrical signals in a primary cilium

A technique that measures ciliary electrical activity will be useful in examining ciliary signaling pathways that use ion channels. Several channel proteins (TRPP2, TRPC1, TRPV4, α-epithelial sodium channel) and recep- tors (for example, epidermal growth factor receptor, type 2 vasopressin receptor) have been localized to renal pri- mary cilia [13-18,57]. A wide variety of renal stimuli have been shown to alter the activity of these channels: TRPP2 (fluid flow [12], epidermal growth factor [57], pH [58], voltage [58], cytoplasmic calcium [31,34]); the TRPP2/TRPC1 complex (G-protein coupled receptor agonists [17]); and the TRPP2/TRPV4 complex (heat, swelling, external calcium [18]). It seems likely that dif- ferent cells will have different channels localized to their primary cilia for the transduction of different stimuli. For example, TRPP2 is present on the primary cilium of the following cells and has been hypothesized or shown to transduce mechanical stimuli: embryonic node cells, ovarian granulosa cells, cholangiocytes, vascular smooth muscle cells, and vascular endothelial cells [59-63]. TRPV4 is present on the primary cilia of cholangiocytes and mediates a response to changes in osmolarity [8]. In neurons, several receptors for channel-containing path- ways have been localized to primary cilia (for example, melanin-concentrating hormone receptor 1 [64,65]), al- though corresponding ciliary channels have not yet been found. The utility of our method should increase when coupled with methods for manipulating the expression of ciliary proteins. Targeted ciliary expression has been possible in IMCD [54,66] and other cell lines [67-69]. Recording from cells treated to knock down ciliary chan- nel proteins should aid in identifying subunits contribut- ing to channel function.
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Importance and challenges of measuring intrinsic foot muscle strength

Importance and challenges of measuring intrinsic foot muscle strength

Indirect methods such as imaging modalities [6,21-24, 55-57], electromyography [3,12] and muscle biopsy [13] are able to discriminate between intrinsic and extrinsic muscles. Indirect methods can assess muscle morphology [6,21-24,55-57], activation patterns [3,12,41] and histo- chemical properties [13] of intrinsic foot muscles. However, indirect methods are unable to directly measure intrinsic muscle strength. Among the imaging modalities, MRI seems to be the most effective method to visualise intrinsic muscles of the foot because of its multiplanar views [58,59], safety [2,58,59] and high resolution [58,59]. In contrast, CT uses ionising radiation [2,58,59] and has lower contrast resolution compared to MRI [58]. Ultrasonography has the lowest resolution of the three imaging modalities [2,59,68] and the reproducibility of the image is operator dependant [59]. Muscle biopsy [13,74] and intramuscular EMG [73] assess only a small number of muscle fibres and thus the findings may not be representative of the whole muscle. Therefore, it seems MRI is the best indirect method to as- sess intrinsic muscle morphological properties such as PCSA and volume to identify muscle atrophy. A relation- ship between muscle volume and its force generating cap- acity in the foot has only been demonstrated in ankle dorsiflexor and plantar flexor muscles. Other factors such as neural drive and biomechanical consideration such as muscle-tendon length and moment arms of muscles may also impact the force generating capacity of muscles [39,75]. Biomechanical muscle modelling based on intrinsic muscle morphological data from MRI represents a promis- ing new approach for quantifying intrinsic muscle force in the future [63,65]. However, one of the main challenges with using mathematical models to predict muscle force depends on the accuracy of its parameters [65] such as muscle fibre length and pennation angle, which are often taken from cadaver studies. At present, muscle modelling has only been used to accurately predict muscle forces and torques around the ankle [65] and knee joints [63].
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Influence of muscle mass and bone mass on the mobility of elderly women: an observational study

Influence of muscle mass and bone mass on the mobility of elderly women: an observational study

This test is an effective method to evaluate the mobility and quantify the locomotor performance [18], and it is a predictor of the risk of falls and of the dynamic equilibrium of the elderly people [19]. The individual is requested to rise from a chair (45 cm) and walk as quickly and safely as possible for 3 m in a straight line and then walk back to the chair and sit as in the initial position. Literature categorizes this test on three levels from the run time: ≤10 seconds (TUG 1); between 10.01 and 20 s (TUG 2); and over 20.01 s (TUG 3) [14]; however, this research considered the time of the test as a continuous variable.
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A simple method for measuring the bilateral symmetry of leaves

A simple method for measuring the bilateral symmetry of leaves

Bilateral symmetry in biology has attracted much attention, and some methods for measuring the bilateral symmetry of objects have been proposed [1–9]. The leaf is the most important organ of plants for photosynthesis, and leaf shape has been demonstrated to be linked to photosynthetic rates and temperature optima in some plants [10]. Many plants have leaves that exhibit bilateral symmetry. Thompson [1] studied the leaf shape of Begonia daedalea Lem. and proposed a hypothesis that the left side of the lamina is proportional to its right side. This hypothesis was confirmed by using the experimental data of Begonia loranthoides Hook. f. [11]. There are two kinds of bilateral symmetry: matching symmetry and object symmetry [5]. The former denotes the symmetry of two body parts of the same creature (e.g., left and right wings of a bird, left and right hands of a person), and the latter denotes that of two sides of the same organ (e.g., left and right sides of a human face, left and right sides of a leaf). A method for measuring bilateral symmetry was developed in Mardia et al. [5], which requires measuring several paired landmarks of the object and involves a complex calculation based on Procrustes superimposition. There is some shape information lost in measuring bilateral symmetry, because some edge points (non-landmarks) are neglected. The leaf shapes of some trees are rather complex (e.g., the toothed leaf), and there may be many landmarks that will be too time-consuming to measure in practice. In addition, for the leaf which has an edge that forms a smooth arc (e.g.,
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Glucogold: supports the maintenance of lean muscle mass and the immune system

Glucogold: supports the maintenance of lean muscle mass and the immune system

Prolonged exercise is known to cause an elevation in plasma cortisol concentration, which stimulates not only protein catabolism and glutamine release but also increases gluconeogenesis in the liver, gastrointestinal tract, and kidneys [14]. Increased hepatic, gastrointestinal, and renal uptake of glutamine could place a significant drain on plasma glutamine availability after prolonged exercise. Similar changes in plasma stress hormones occur after starvation, surgical trauma, sepsis, burns, and prolonged exercise, and all of these states of catabolic stress are characterized by lowered plasma glutamine concentrations, depressed cellular immunity, and increased gluconeogenesis [8]. In conditions of metabolic acidosis, the renal uptake of glutamine increases to provide for ammoniagenesis. Dietinduced metabolic acidosis with a high-protein (24% of energy): high-fat (72% of energy) diet for 4 d led to a 25% reduction in the concentrations of glutamine in both plasma and muscle (15). In this situation, it seems likely that release of glutamine from muscle may have increased, along with renal uptake, in an attempt to maintain acid-base balance. Walsh et al. [9] have suggested that a common mechanism may be responsible for depletion of plasma glutamine after prolonged exercise, starvation, and physical trauma, namely, increased hepatic and gastrointestinal uptake of glutamine for gluconeogenesis at a time when muscle release of glutamine remains constant or falls.
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The age related loss of skeletal muscle mass and function: measurement and physiology of muscle fibre atrophy and muscle fibre loss in humans

The age related loss of skeletal muscle mass and function: measurement and physiology of muscle fibre atrophy and muscle fibre loss in humans

Finally, the production of reactive oxygen and nitrogen species (RONS) and oxidative damage has long been thought of as a potential mechanism of age-related muscle atrophy through the radical theory of ageing, whereby RONS damage proteins, lipids and DNA leading to dysfunction of the tissues (Harman, 1956). Moreover, an essential role has been proposed for ROS in regulating the IGF-AKT-mTOR signalling pathway (Nacarelli et al., 2015), which in turn can directly impact control of muscle protein turnover. Although much of this work has been performed in genetic pre-clinical models (e.g. knocking out genes involved in scavenging free radicals), a recent human study looking at levels of protein carbonylation - a marker of oxidative damage - in muscle showed that levels of protein carbonyls increased with age, but no difference was observed between those designated as sarcopenic and non-sarcopenic (Beltran Valls et al., 2015). Therefore the contribution of RONS to age related muscle decline remains debatable, while the use of antioxidant therapies has proved largely unsuccessful (Deane et al., 2017), and with antioxidants potentially having adverse effects on muscle (Gomez-Cabrera et al., 2008). As such, while their role is difficult to define in humans, there is little evidence that redox imbalances are key drivers of age- related muscle atrophy, nor in response human disuse atrophy (Glover et al., 2010).
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