2J-5 Ultrafast Ultrasonic Imaging of In Vivo Muscle Contraction

2006 ◽  
Author(s):  
T. Deffieux ◽  
J.-L. Gennisson ◽  
M. Tanter ◽  
M. Fink
Keyword(s):  
Muscle Contraction ◽  
Ultrasonic Imaging

scholarly journals MP06-12 GHRELIN-MEDIATED PROMOTION OF PROSTATE GROWTH AND PROSTATE SMOOTH MUSCLE CONTRACTION: EVIDENCE FROM FUNCTIONAL, IN VIVO, AND GENOMIC APPROACHES

2019 ◽  
Vol 201 (Supplement 4) ◽  
Author(s):  
Xiaolong Wang* ◽  
Yiming Wang ◽  
Christian Gratzke ◽  
Bingsheng Li ◽  
Qingfeng Yu ◽  
...  
Keyword(s):  
Smooth Muscle ◽  
Muscle Contraction ◽  
Smooth Muscle Contraction ◽  
Prostate Growth

Myogenic mechanism for peristalsis in the cat esophagus

1999 ◽  
Vol 277 (2) ◽  
pp. G306-G313 ◽  
Author(s):  
Harold G. Preiksaitis ◽  
Nicholas E. Diamant
Keyword(s):  
Muscle Contraction ◽  
Slow Wave ◽  
Circular Muscle ◽  
Smooth Muscle Contraction ◽  
Slow Waves ◽  
Mechanical Activity ◽  
Control Mechanisms ◽  
Slow Wave Oscillations

A myogenic control system (MCS) is a fundamental determinant of peristalsis in the stomach, small bowel, and colon. In the esophagus, attention has focused on neuronal control, the potential for a MCS receiving less attention. The myogenic properties of the cat esophagus were studied in vitro with and without nerves blocked by 1 μM TTX. Muscle contraction was recorded, while electrical activity was monitored by suction electrodes. Spontaneous, nonperistaltic, electrical, and mechanical activity was seen in the longitudinal muscle and persisted after TTX. Spontaneous circular muscle activity was minimal, and peristalsis was not observed without pharmacological activation. Direct electrical stimulation (ES) in the presence of bethanechol or tetraethylammonium chloride (TEA) produced slow-wave oscillations and spike potentials accompanying smooth muscle contraction that progressed along the esophagus. Increased concentrations of either drug in the presence of TTX produced slow waves and spike discharges, accompanied by peristalsis in 5 of 8 TEA- and 2 of 11 bethanechol-stimulated preparations without ES. Depolarization of the muscle by increasing K+ concentration also produced slow waves but no peristalsis. We conclude that the MCS in the esophagus requires specific activation and is manifest by slow-wave oscillations of the membrane potential, which appear to be necessary, but are not sufficient for myogenic peristalsis. In vivo, additional control mechanisms are likely supplied by nerves.

Ultrasonic imaging of in vivo bubbles in decompression sickness

Ultrasonics ◽  
1971 ◽  
Vol 9 (4) ◽  
pp. 225-234 ◽  
Author(s):  
G.J. Rubissow ◽  
R.S. Mackay
Keyword(s):  
Decompression Sickness ◽  
Ultrasonic Imaging

scholarly journals Combined diffusion and strain tensor MRI reveals a heterogeneous, planar pattern of strain development during isometric muscle contraction

2011 ◽  
Vol 300 (5) ◽  
pp. R1079-R1090 ◽  
Author(s):  
Erin K. Englund ◽  
Christopher P. Elder ◽  
Qing Xu ◽  
Zhaohua Ding ◽  
Bruce M. Damon
Keyword(s):  
Muscle Contraction ◽  
Muscle Fiber ◽  
Diffusion Tensor ◽  
Strain Tensor ◽  
Three Dimensional ◽  
Fiber Direction ◽  
Strain Pattern ◽  
Isometric Muscle Contraction ◽  
Diffusion Tensors

The purposes of this study were to create a three-dimensional representation of strain during isometric contraction in vivo and to interpret it with respect to the muscle fiber direction. Diffusion tensor MRI was used to measure the muscle fiber direction of the tibialis anterior (TA) muscle of seven healthy volunteers. Spatial-tagging MRI was used to measure linear strains in six directions during separate 50% maximal isometric contractions of the TA. The strain tensor (E) was computed in the TA's deep and superficial compartments and compared with the respective diffusion tensors. Diagonalization of E revealed a planar strain pattern, with one nonzero negative strain (εN) and one nonzero positive strain (εP); both strains were larger in magnitude ( P < 0.05) in the deep compartment [εN = −40.4 ± 4.3%, εP = 35.1 ± 3.5% (means ± SE)] than in the superficial compartment (εN = −24.3 ± 3.9%, εP = 6.3 ± 4.9%). The principal shortening direction deviated from the fiber direction by 24.0 ± 1.3° and 39.8 ± 6.1° in the deep and superficial compartments, respectively ( P < 0.05, deep vs. superficial). The deviation of the shortening direction from the fiber direction was due primarily to the lower angle of elevation of the shortening direction over the axial plane than that of the fiber direction. It is concluded that three-dimensional analyses of strain interpreted with respect to the fiber architecture are necessary to characterize skeletal muscle contraction in vivo. The deviation of the principal shortening direction from the fiber direction may relate to intramuscle variations in fiber length and pennation angle.

scholarly journals In vivo recovery of muscle contraction after alpha-bungarotoxin binding.

1975 ◽  
Vol 66 (1) ◽  
pp. 209-213 ◽  
Author(s):  
H C Fertuck ◽  
W Woodward ◽  
M M Salpeter
Keyword(s):  
Fine Structure ◽  
Neuromuscular Junction ◽  
Muscle Contraction ◽  
Acetylcholine Receptors ◽  
Actinomycin D ◽  
Recovery Period ◽  
Em Autoradiography ◽  
Alpha Bungarotoxin ◽  
In Vivo Recovery

Acetylcholine receptors were inactivated in vivo at the mouse neuromuscular junction using alpha-bungarotoxin (alpha-BTX). It was found that neurally produced muscle contraction recovered within 4-8 days (halftime similar to 3 days). Actinomycin D interfered with this recovery, but did not affect normal nerve-stimulated muscle contraction. If the response was initially eliminated by [125-I]alpha-BTX and the end plates examined by EM autoradiography, no evidence of mass internalization of bound radioactivity during recovery was seen. The fine structure of the end plates and muscle was unaltered during the post-alpha-BTX recovery period.

Stabilized bubbles in the body: pressure-radius relationships and the limits to stabilization

1997 ◽  
Vol 82 (6) ◽  
pp. 2045-2053 ◽  
Author(s):  
Hugh D. Van Liew ◽  
Soumya Raychaudhuri
Keyword(s):  
Contrast Agents ◽  
Conceptual Framework ◽  
Bubble Radius ◽  
Ultrasonic Imaging ◽  
Ultrasound Contrast Agents ◽  
The Body ◽  
Strong Growth ◽  
Ultrasound Contrast ◽  
Practical Usefulness

Van Liew, Hugh D., and Soumya Raychaudhuri. Stabilized bubbles in the body: pressure-radius relationships and the limits to stabilization. J. Appl. Physiol.82(6): 2045–2053, 1997.—We previously outlined the fundamental principles that govern behavior of stabilized bubbles, such as the microbubbles being put forward as ultrasound contrast agents. Our present goals are to develop the idea that there are limits to the stabilization and to provide a conceptual framework for comparison of bubbles stabilized by different mechanisms. Gases diffuse in or out of stabilized bubbles in a limited and reversible manner in response to changes in the environment, but strong growth influences will cause the bubbles to cross a threshold into uncontrolled growth. Also, bubbles stabilized by mechanical structures will be destroyed if outside influences bring them below a critical small size. The in vivo behavior of different kinds of stabilized bubbles can be compared by using plots of bubble radius as a function of forces that affect diffusion of gases in or out of the bubble. The two ends of the plot are the limits for unstabilized growth and destruction; these and the curve’s slope predict the bubble’s practical usefulness for ultrasonic imaging or O2 carriage to tissues.

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