scholarly journals Muscle Fiber Diameter and Density Alterations after Stroke Examined by Single-Fiber EMG

2021 ◽  
Vol 2021 ◽  
pp. 1-7
Author(s):  
Chengjun Huang ◽  
Bo Yao ◽  
Xiaoyan Li ◽  
Sheng Li ◽  
Ping Zhou
Keyword(s):  
Muscle Fiber ◽  
Fiber Diameter ◽  
Quadratic Function ◽  
Motor Units ◽  
Single Fiber ◽  
Fiber Density ◽  
Negative Peak ◽  
Hemiparetic Stroke ◽  
Muscle Changes ◽  
Contralateral Muscle

This study presents single-fiber electromyography (EMG) analysis for assessment of paretic muscle changes after stroke. Single-fiber action potentials (SFAPs) were recorded from the first dorsal interosseous (FDI) muscle bilaterally in 12 individuals with hemiparetic stroke. The SFAP parameters, including the negative peak duration and the peak-peak amplitude, were measured and further used to estimate muscle fiber diameter through a model based on the quadratic function. The SFAP parameters, fiber density, and muscle fiber diameter derived from the model were compared between the paretic and contralateral muscles. The results show that SFAPs recorded from the paretic muscle had significantly smaller negative peak duration than that from the contralateral muscle. As a result, the derived muscle fiber diameter of the paretic muscle was significantly smaller than that of the contralateral muscle. The fiber density of the paretic muscle was significantly higher than that of the contralateral muscle. These results provide further evidence of remodeled motor units after stroke and suggest that paretic muscle weakness can be due to both complex central and peripheral neuromuscular alterations.

P62-F Estimation of the muscle fiber diameter from single fiber potentials: A simulation study

2019 ◽  
Vol 130 (7) ◽  
pp. e85
Author(s):  
Imran Goker ◽  
Mehmet Baris Baslo ◽  
Peyman Mahouti
Keyword(s):  
Muscle Fiber ◽  
Simulation Study ◽  
Fiber Diameter ◽  
Single Fiber

scholarly journals A method for determination of muscle fiber diameter using single fiber potential (SFP) analysis

2012 ◽  
Vol 50 (12) ◽  
pp. 1309-1314 ◽  
Author(s):  
Ewa Zalewska ◽  
Sanjeev D. Nandedkar ◽  
Irena Hausmanowa-Petrusewicz
Keyword(s):  
Muscle Fiber ◽  
Fiber Diameter ◽  
Single Fiber

Quantitative Diameter Measurements of Chromatin and TMV Fibers in the Freeze-Dried State

1988 ◽  
Vol 46 ◽  
pp. 170-171
Author(s):  
B. D. Athey ◽  
A. L. Stout ◽  
M. F. Smith ◽  
J. P. Langmore
Keyword(s):  
Reliable Method ◽  
Fiber Diameter ◽  
Quantitative Agreement ◽  
One Dimension ◽  
Fiber Axis ◽  
Two Dimensional ◽  
Fiber Density ◽  
Variable Diameter ◽  
Freeze Dried ◽  
Expected Values

Although there is general agreement that Inactive chromosome fibers consist of helically packed nucleosomes, the pattern of packing is still undetermined. Only one of the proposed models, the crossed-linker model, predicts a variable diameter dependent on the length of DNA between nucleosomes. Measurements of the fiber diameter of negatively-stained and frozen- hydrated- chromatin from Thyone sperm (87bp linker) and Necturus erythrocytes (48bp linker) have been previously reported from this laboratory. We now introduce a more reliable method of measuring the diameters of electron images of fibrous objects. The procedure uses a modified version of the computer program TOTAL, which takes a two-dimensional projection of the fiber density (represented by the micrograph itself) and projects it down the fiber axis onto one dimension. We illustrate this method using high contrast, in-focus STEM images of TMV and chromatin from Thyone and Necturus. The measured diameters are in quantitative agreement with the expected values for the crossed-linker model for chromatin structure

scholarly journals Effects of Dietary Paper Mulberry (Broussonetia Papyrifera) on Growth Performance and Muscle Quality of Grass Carp (Ctenopharyngodon idella)

Animals ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 1655
Author(s):  
Tao Tang ◽  
Jinhai Bai ◽  
Zhipeng Ao ◽  
Zehong Wei ◽  
Yi Hu ◽  
...  
Keyword(s):  
Growth Performance ◽  
Muscle Fiber ◽  
Grass Carp ◽  
Crude Protein ◽  
Fiber Diameter ◽  
Control Diet ◽  
Ctenopharyngodon Idella ◽  
Muscle Quality ◽  
Control Group ◽  
Broussonetia Papyrifera

The present study investigated the effects of dietary paper mulberry (Broussonetia Papyrifera, BP) on growth performance, muscle quality and muscle growth-related mRNA expressions of grass carp. Fish (initial weight: 50.0 ± 0.5 g) were fed diets supplemented with 0% (control diet), 5%, 10%, 15% and 20% BP for 8 weeks. The results showed that increasing levels of paper mulberry linearly and quadratically decreased the special gain rate (SGR) and increased the feed conversion rate (FCR) of grass carp (p < 0.05). Significantly positive quadratic trends were found between paper mulberry levels and muscle crude fat or crude protein of grass carp (p < 0.05). In comparison to the control diet, the 10%BP and 15%BP groups had significantly decreased muscle crude fat and increased crude protein (p < 0.05). The levels of paper mulberry resulted in a linear and quadratic increase in water loss of grass carp muscle (p < 0.05), and all groups with paper mulberry supplementation were significantly higher than the control group (p < 0.05). Significant positive linear and quadratic trends were found between the paper mulberry levels and muscle fiber diameter or density of grass carp (p < 0.05). In comparison to the control diet, the significant differences were found in the 15%BP and 20%BP groups (p < 0.05). The muscle adhesiveness and hardness linearly and quadratically increased with the increasing levels of paper mulberry (p < 0.05), and both of which increased significantly when the level of paper mulberry reached 10% (p < 0.05). In addition, the increase in paper mulberry linearly and quadratically improved the expressions of myoblast determination protein (MyoD), myogenin (MyoG), paired box protein 7 (Pax7) and myostatin 1 (MSTN1) (p < 0.05). When the supplementation of paper mulberry reached 15%, the expressions of all these mRNAs were significantly higher than those of the control group (p < 0.05). In summary, adding 5% paper mulberry did not affect the growth of grass carp. However, the supplementation of 10% paper mulberry could improve muscle quality through improving muscle hardness, reducing fat accumulation and muscle fiber diameter, at the cost of reducing growth performance.

Changes in muscle fiber conduction velocity indicate recruitment of distinct motor unit populations

2003 ◽  
Vol 95 (3) ◽  
pp. 1045-1054 ◽  
Author(s):  
C. J. Houtman ◽  
D. F. Stegeman ◽  
J. P. Van Dijk ◽  
M. J. Zwarts
Keyword(s):  
Conduction Velocity ◽  
Muscle Fiber ◽  
Tibialis Anterior Muscle ◽  
Maximum Voluntary Contraction ◽  
Isometric Exercise ◽  
Motor Units ◽  
Voluntary Contraction ◽  
Type I ◽  
Muscle Fiber Conduction Velocity ◽  
Depth Study

To obtain more insight into the changes in mean muscle fiber conduction velocity (MFCV) during sustained isometric exercise at relatively low contraction levels, we performed an in-depth study of the human tibialis anterior muscle by using multichannel surface electromyogram. The results show an increase in MFCV after an initial decrease of MFCV at 30 or 40% maximum voluntary contraction in all of the five subjects studied. With a peak velocity analysis, we calculated the distribution of conduction velocities of action potentials in the bipolar electromyogram signal. It shows two populations of peak velocities occurring simultaneously halfway through the exercise. The MFCV pattern implies the recruitment of two different populations of motor units. Because of the lowering of MFCV of the first activated population of motor units, the newly recruited second population of motor units becomes visible. It is most likely that the MFCV pattern can be ascribed to the fatiguing of already recruited predominantly type I motor units, followed by the recruitment of fresh, predominantly type II, motor units.

scholarly journals An electrophysiological investigation of skeletal muscle in human chronic Chagas' disease

1978 ◽  
Vol 36 (4) ◽  
pp. 319-326 ◽  
Author(s):  
Olga P. Sanz ◽  
A. F. Ratusnu ◽  
G. G. Aristimuño ◽  
E. M. O'Neill ◽  
R. E. P. Sica
Keyword(s):  
Chagas Disease ◽  
Electrophysiological Study ◽  
Motor Units ◽  
Normal Range ◽  
Primary Defect ◽  
Repetitive Nerve Stimulation ◽  
Conduction Velocities ◽  
Muscle Changes ◽  
Chronic Chagas Disease ◽  
Extensor Digitorum Brevis

An electrophysiological study has been made of the thenar, hypothenar, soleus and extensor digitorum brevis muscles and their inervation in 90 patients with chronic Chagas' disease. Some of them showed a reduced number of functional motor units with increased size of many of the surviving units. No decremental muscle response was found to repetitive nerve stimulation. Motor and sensory conduction velocities as well as motor terminal latencies were on the normal range. These findings suggested that the muscle changes resulted from a primary defect of the alpha spinal motoneurone soma.

Sign in / Sign up

Export Citation Format

Share Document