Imaging skeletal muscle

FIGURE 17.23 The mechanism of skeletal muscle contraction. The free energy of ATP hydrolysis drives a conformational change in the myosin head, resulting in net movement of the myosin heads along the actin filament. Inset) A ribbon and space-filling representation of the actin—myosin interaction. (SI myosin image courtesy of Ivan Rayment and Hazel M. Holden, University of Wiseonsin, Madison.)... 

I. Sack, J. Bernarding and J. Braun, Analysis of wave patterns in MR elastography of skeletal muscle using coupled harmonic oscillator simulations, Magn. reson. Imaging, 2002, 20, 95-104. 

C. Thomsen, K. E. Jensen and O. Henriksen, In vivo measurements of T1 relaxation times of 31P-metabolites in human skeletal muscle. Magn. Reson. Imaging, 1989, 7, 231-234. 

U. Sharma, V. Kumar, S. Wadhwa and N. R. Jagannathan, In vivo MRS study of skeletal muscle metabolism in patients with postpolio residual paralysis. Magn. Resort. Imaging, 2007, 25,244 249. 

Figure 16.21. In vivo 31P spectrum of skeletal muscle. (Reprinted with permission from Edleman RR, Hesselink JR, Zlatkin MB, eds. Clinical Magnetic Resonance Imaging, vol. 1. W. B. Saunders Company, Philadelphia, 1996. Copyright 1996 W. B. Saunders Company.)...

In this context, the Ca + sensitivity of the RyRs, as well as the evaluation of the local Ca + concentration to which they are exposed, is a key factor in determining the excitability of the muscle fiber and the efficiency and duration of contraction. As a result, a great deal of work has concentrated on identifying the fundamental Ca + signaling. Rapid Ca + imaging of both cardiac and skeletal muscle has revealed the occurrence of transient, local increases in Ca + concentration, denominated Ca + sparks (9) that were attributed to the opening of single RyR channels, or more likely, a cluster of RyRs (10, 11). 

Tsugorka A, Rios E, Blatter LA. Imaging elementary events of calcium release in skeletal muscle cells. Science 1995 269 1723-1726. 

Jarajapu YPR, Macdonald A, Hillier C, McGrath JC, Mackenzie JF, Daly CJ. Quantitative imaging of QAPB-associated fluorescence in smooth muscle cells from human skeletal muscle resistance arteries. Br J Pharmacol 2002 135 303P. 

Fig. 4 Utilization of Morphology Explorer to determine optimal time point of differentiated myotubes. Images of human skeletal muscle cells stained by immunofluorescence of a-myosin heavy chain (a-MHC), Titin, Vimentin, and nuclei by Hoechst 33342 were acquired at 2 days before cell confluence (-2), at cell confluence (0), and at day 3,7,10, and 14 post cell confluence (a-r) Quantitative readouts of cell culture features, obtained from four selected output parameters from the Morphology Explorer bio-application, showed that peak of differentiated myotubes were obtained on day 3 post confluence (s-v)...

Within the context of muscle tissue, FT-IR and Raman imaging have each been applied more often to smooth muscle than to skeletal muscle. Both, FT-IR and Raman imaging of blood vessels were used to obtain chemical and spatial information about atherosclerosis [14—16]. Raman images of bronchial tissue containing not only cartilage and epithelium but also smooth muscle were reported [17]. Other FT-IR and Raman imaging studies on the esophagus, intestine and uterus concentrated rather on the epithelium than on smooth muscle, mainly because carcinomas arise in the epithehal tissues. 

Fig. 20. Average spatial temperature profiles produced by ultrasound sonications given in tumours implanted in the skeletal muscle of rabbits, (left) Phase difference image showing a localized area of heating, (middle) corresponding temperature profile across the focus (right) profile across the focus with a plastic lens placed in front of the transducer. (Reprinted from ref. 273 by permission of Wiley-Liss, Inc., a subsidiary of John Wiley Sons, Inc., Copyright 1998 John Wiley.)...

Meanwhile, on T2-weighted images, tumor intensity brighter than that of skeletal muscle compared to those equal to or lower than that of skeletal muscle was predictive of good response (p=0.007), echoed also by deSouza and Williams [27]. High... 

Brandejsky et al have shown the possibility of using proton magnetic resonance spectroscopy to investigate the in vim properties of intramyo-cellular lipids in human skeletal muscle. Last, but not least, Narayan et al developed a novel 3-point Dixon technique base on the analysis of 7T magnetic resonance images in the presence of field inhomogeneity to study metabolic disorders in small animals. 

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