High-shore mussels, Mytilus californianus, have larger muscle fibers with lower aerobic capacities than low-shore conspecifics

2019 ◽  
Vol 166 (2) ◽  
Author(s):  
W. Wesley Dowd ◽  
Ana G. Jimenez
Keyword(s):  
Muscle Fibers ◽  
Mytilus Californianus ◽  
High Shore

Mitochondrial Changes in Choline-Deficient Rat Myocardium

1968 ◽  
Vol 26 ◽  
pp. 112-113
Author(s):  
F. G. Zaki
Keyword(s):  
Muscle Fibers ◽  
Liver Mitochondria ◽  
Ultrastructural Changes ◽  
Choline Deficiency ◽  
Nutritional Disorder ◽  
Low Protein ◽  
Structural Abnormalities ◽  
Cross Striation ◽  
Pericardial Edema ◽  
Myocardial Lesions

Choline-deficiency was induced in Holtzman young rats of both sexes by feeding them a high fat - low protein diet.Preliminary studies of the ultrastructural changes in the myocardium of these animals have been recently reported from this laboratory. Myocardial lesions first appeared in the form of intraventricular mural thrombi, loss of cross striation of muscle fibers and focal necrosis of muscle cells associated with interstitial myocarditis. Prolonged choline-deficiency induced cardiomegaly associated with pericardial edema.During the early phase of this nutritional disorder, heart mitochondria - despite of not showing any swelling similar to that usually encountered in liver mitochondria of the same animal - ware the most ubiquitous site of marked structural abnormalities. Early changes in mitochondria appeared as vacuolation, disorganization, disruption and loss of cristae. Degenerating mitochondria were often seen quite enlarged and their matrix was replaced by whorls of myelin figures resembling lysosomal structures especially where muscle fibers were undergoing necrosis. In some areas, mitochondria appeared to be unusually clumped together where some contained membranelined vacuoles and others enclosed dense bodies and granular inclusions.

The “KIMWIPE” Effect in Ultra-Thin Cryosections

1985 ◽  
Vol 43 ◽  
pp. 458-459
Author(s):  
I. Taylor ◽  
P. Ingram ◽  
J.R. Sommer
Keyword(s):  
Skeletal Muscle ◽  
Electrical Stimulation ◽  
Muscle Fibers ◽  
Ice Crystals ◽  
Crystal Formation ◽  
Ice Crystal ◽  
Thin Sections ◽  
Skeletal Muscle Fibers ◽  
Freeze Dried ◽  
Ice Crystal Formation

In studying quick-frozen single intact skeletal muscle fibers for structural and microchemical alterations that occur milliseconds, and fractions thereof, after electrical stimulation, we have developed a method to compare, directly, ice crystal formation in freeze-substituted thin sections adjacent to all, and beneath the last, freeze-dried cryosections. We have observed images in the cryosections that to our knowledge have not been published heretofore (Figs.1-4). The main features are that isolated, sometimes large regions of the sections appear hazy and have much less contrast than adjacent regions. Sometimes within the hazy regions there are smaller areas that appear crinkled and have much more contrast. We have also observed that while the hazy areas remain still, the regions of higher contrast visibly contract in the beam, often causing tears in the sections that are clearly not caused by ice crystals (Fig.3, arrows).

Justification of technical parameters of an ultrasonic device for improvement of meat salting efficiency

2020 ◽  
pp. 75-77
Author(s):  
Ekaterina Sergeevna Krasnikova ◽  
Natalya Lvovna Morgunova ◽  
Phelix Yakovlevich Rudik ◽  
Aleksandr Vladimirovich Krasnikov ◽  
Nikita Andreevich Semilet
Keyword(s):  
Technological Process ◽  
Muscle Tissue ◽  
Muscle Fibers ◽  
Tissue Structure ◽  
Tissue Microstructure ◽  
Technical Parameters ◽  
Ultrasonic Device ◽  
Lamb Meat ◽  
Local Destruction ◽  
Cross Striation

The results of a study of the effect of wet ultrasonic lamb meat salting on the muscle tissue microstructure are presented, and the technical parameters of the ultrasonic device are justified. It has been established that significant destruction and swelling of muscle fibers, local destruction of the sarcolemma with its pronounced rugosity are observed at ultrasonic salting with a frequency of 35 kHz, the cross-striation is poorly expressed, the tissue structure is disturbed. An ultrasonic salting with a frequency of 26 kHz was accompanied an increase in the number of transverse microcracks and crevices, loosening of muscle fibers, the formation of cavities between them while retention of the tissue structure, which contributes to the appearance of a brine between muscle fibers and accelerates its penetration into the fiber. It allows us to recommend ultrasound at a frequency of 26 kHz for cavitation activation of the brine to intensify the technological process of lamb meat salting.

Effect of External Calcium and other Divalent Cations on K+ Contractures in Denervated Slow Skeletal Muscle Fibers of the Frog

2019 ◽  
Author(s):  
Leonardo Hernández
Keyword(s):  
Skeletal Muscle ◽  
Binding Capacity ◽  
Divalent Cations ◽  
Muscle Fibers ◽  
Free Calcium ◽  
Slow Skeletal Muscle ◽  
Skeletal Muscle Fibers ◽  
Free Calcium Concentration ◽  
Chronic Denervation ◽  
Denervated Muscles

The influence of Ca2+ and other divalent cations on contractile responses of slow skeletal muscle fibers of the frog (Rana pipiens) under conditions of chronic denervation was investigated.Isometric tension was recorded from slow bundles of normal and denervated cruralis muscle in normal solution and in solutions with free calcium concentration solution or in solutions where other divalent cations (Sr2+, Ni2+, Co2+ or Mn2+) substituted for calcium. In the second week after nerve section, in Ca2+-free solutions, we observed that contractures (evoked from 40 to 80 mM-K+) of non-denervated muscles showed significantly higher tensions (p<0.05), than those from denervated bundles. Likewise, in solutions where calcium was substituted by all divalent cations tested, with exception of Mn2+, the denervated bundles displayed lower tension than non-denervated, also in the second week of denervation. In this case, the Ca2+ substitution by Sr2+ caused the higher decrease in tension, followed by Co2+ and Ni2+, which were different to non-denervated bundles, as the lowest tension was developed by Mn2+, followed by Co2+, and then Ni2+ and Sr2+. After the third week, we observed a recovery in tension. These results suggest that denervation altering the binding capacity to divalent cations of the voltage sensor.

What Can We Learn from Sarcopenia with Curarisation in the Context of Cancer Surgery? A Review of the Literature

2019 ◽  
Vol 25 (28) ◽  
pp. 3005-3010
Author(s):  
Georges Samouri ◽  
Alexandre Stouffs ◽  
Lionel V. Essen ◽  
Olivier Simonet ◽  
Marc De Kock ◽  
...  
Keyword(s):  
Frail Elderly ◽  
Muscle Fibers ◽  
Motor Units ◽  
The Elderly ◽  
Hepatic Function ◽  
Volume Of Distribution ◽  
Neuromuscular Blocking ◽  
Cancer Surgery ◽  
Old People ◽  
Age Related

Introduction: The monitoring of the curarisation is a unique opportunity to investigate the function of the neuromuscular junction (NMJ) during cancer surgery, especially in frailty-induced and age-related sarcopenia. Method: We conducted a comprehensive literature review in PubMed, without any limit of time related to frailty, sarcopenia, age and response to neuromuscular blockers in the context of cancer surgery. Results: Several modifications appear with age: changes in cardiac output, a decrease in muscle mass and increase in body fat, the deterioration in renal and hepatic function, the plasma clearance and the volume of distribution in elderly are smaller. These changes can be exacerbated in cancer patients. We also find modifications of the NMJ: dysfunctional mitochondria, modifications in the innervation of muscle fibers and motor units, uncoupling of the excitation-contraction of muscle fibers, inflammation. : Neuromuscular blocking agents (NMBAs) compete with acetylcholine and prevent it from fixing itself on its receptor. Many publications reported guidelines for using NMBAs in the elderly, based on studies comparing old people with young people. : No one screened frailty before, and thus, no studies compared frail elderly and non-frail elderly undergoing cancer surgery. Conclusion: Despite many studies about curarisation in the specific populations, and many arguments for a potential interest for investigation, no studies investigated specifically the response to NMBAs in regard of the frailty-induced and age-related sarcopenia.

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