scholarly journals The effects of aging on biceps brachii muscle fibers: a morphometrical study from biopsies and autopsies

2003 ◽  
Vol 61 (3A) ◽  
pp. 555-560 ◽  
Author(s):  
Ana Cláudia Mattiello-Sverzut ◽  
Leila Chimelli ◽  
Maria Silvia de Assis Moura ◽  
Silvia Teixeira ◽  
José Alberto Mello de Oliveira
Keyword(s):  
Cross Sections ◽  
Biceps Brachii ◽  
Muscle Fibers ◽  
Atpase Reaction ◽  
Fiber Size ◽  
Effects Of Aging ◽  
Sixth Decade ◽  
Morphometrical Study

OBJECTIVES: In order to study the morphology and size of muscle fibers, cross sections of biceps brachii samples from autopsies, up to 9 hours after death, and biopsies of 72 subjects were compared. The subjects aged 13 to 84 years in both sexes. METHODS: The samples obtained from autopsies (n=47) were from subjects with sudden death, or who died after acute disease without evidence of neuromuscular involvement. The biopsies (n=25) were from patients with symptoms suggestive of inflammatory or metabolic myopathy, not confirmed morphologically. The lesser diameter of muscle fibers was measured using the ATPase reaction. RESULTS: Morphological analysis showed that aging changes were present from the sixth decade in autopsies, and consisted of atrophy and/or type-grouping. The statistical models adjusted for females in both autopsies and biopsies were linear straight with no variation in fiber size with increasing age. The models adjusted for males in both groups were quadratic, indicating that age influenced the size of different type fibers. In males type 2 were larger than type 1 fibers, and than fibers in females. CONCLUSIONS: These values might be useful as controls, helping interpretation of changes in fiber size in samples obtained from biopsies and autopsies.

A semi-automated measurement of muscle fiber size using the Imaris software

2021 ◽  
Author(s):  
Jennifer E. Gilda ◽  
Joon-Hyuk Ko ◽  
Aviv-Yvonne Elfassy ◽  
Nadav Tropp ◽  
Anna Parnis ◽  
...  
Keyword(s):  
Muscle Atrophy ◽  
Muscle Fiber ◽  
Cross Sections ◽  
Statistical Tests ◽  
Muscle Fibers ◽  
Fluorescent Labeling ◽  
Cross Sectional ◽  
Short Period ◽  
Fiber Size ◽  
Specific Protease

The size and shape of skeletal muscle fibers are affected by various physiological and pathological conditions, such as muscle atrophy, hypertrophy, regeneration, and dystrophies. Hence, muscle fiber cross-sectional area (CSA) is an important determinant of muscle health and plasticity. We adapted the Imaris software to automatically segment muscle fibers based on fluorescent labeling of the plasma membrane, and measure muscle fiber CSA. Analysis of muscle cross sections by the Imaris semi-automated and manual approaches demonstrated a similar decrease in CSA of atrophying muscles from fasted mice compared with fed controls. In addition, we previously demonstrated that downregulation of the Ca2+-specific protease calpain-1 attenuates muscle atrophy. Accordingly, both the Imaris semi-automated and manual approaches showed a similar increase in CSA of fibers expressing calpain-1 shRNA compared with adjacent non-transfected fibers in the same muscle cross section. Although both approaches seem valid for measurements of muscle fiber size, the manual marking method is less preferable because it is highly time-consuming, subjective, and limits the number of cells that can be analyzed. The Imaris semi-automated approach is user-friendly, requires little training or optimization, and can be used to efficiently and accurately mark thousands of fibers in a short period of time. As a novel addition to the commonly used statistics, we also describe statistical tests that quantify the strength of an effect on fiber size, enabling detection of significant differences between skewed distributions that would otherwise not be detected using typical methods.

Progressive metabolite changes in individual human muscle fibers with increasing work rates

1987 ◽  
Vol 252 (6) ◽  
pp. C630-C639 ◽  
Author(s):  
J. L. Ivy ◽  
M. M. Chi ◽  
C. S. Hintz ◽  
W. M. Sherman ◽  
R. P. Hellendall ◽  
...  
Keyword(s):  
Blood Lactate ◽  
Vastus Lateralis ◽  
Muscle Fibers ◽  
Lactate Concentration ◽  
Work Load ◽  
Bicycle Ergometer ◽  
Almost All ◽  
Fast Twitch

Muscle biopsies were obtained from vastus lateralis muscles of four volunteers exercising at increasing work rates on a bicycle ergometer. Samples were taken at rest (t1), after a work load 23% below the blood lactate threshold (t2), 23% above this threshold (t3), and at exhaustion (t4). Individual muscle fibers were typed by their lactate dehydrogenase and adenylokinase levels and assayed for lactate, glucose-6-phosphate, and malate, (which preliminary data indicated to be the most responsive to increased activity) as well as ATP and phosphocreatine. The results in three of the four cases indicated that by the time of the t2 sample, almost all fibers, regardless of type, had been recruited. Additionally, there were no major differences in lactate concentration between type 1 and 2 fibers from muscle samples taken at t1, t2, and t3. It is concluded that in a muscle with fast-twitch glycolytic and slow-twitch oxidative fibers, all fibers share in the contraction to a substantial degree, even at moderate work loads, and that both the type 1 and 2 fibers contribute significantly to the initial rise in blood lactate during a graded exercise task. Metabolite responses in type 2 fibers differed in certain respects among the four participants. This is attributed to differences in their training backgrounds and consequent differences in type 2 fiber oxidative enzyme levels.

scholarly journals Expression of type-specific MHC isoforms in rat intrafusal muscle fibers.

1992 ◽  
Vol 40 (2) ◽  
pp. 293-307 ◽  
Author(s):  
J Kucera ◽  
J M Walro ◽  
L Gorza
Keyword(s):  
Muscle Fibers ◽  
Fiber Types ◽  
Hindlimb Muscles ◽  
Intrafusal Fibers ◽  
Intrafusal Muscle Fibers ◽  
Intrafusal Fiber Types ◽  
Fast Twitch ◽  
Developing Muscle

Myosin heavy chain (MHC) expression by intrafusal fibers was studied by immunocytochemistry to determine how closely it parallels MHC expression by extrafusal fibers in the soleus and tibialis anterior muscles of the rat. Among the MHC isoforms expressed in extrafusal fibers, only the slow-twitch MHC of Type 1 extrafusal fibers was expressed along much of the fibers. Monoclonal antibodies (MAb) specific for this MHC bound to the entire length of bag2 fibers and the extracapsular region of bag1 fibers. The fast-twitch MHC isoform strongly expressed by bag2 and chain fibers had an epitope not recognized by MAb to the MHC isoforms characteristic of developing muscle fibers or the three subtypes (2A, 2B, 2X) of Type 2 extrafusal fibers. Therefore, intrafusal fibers may express a fast-twitch MHC that is not expressed by extrafusal fibers. Unlike extrafusal fibers, all three intrafusal fiber types bound MAb generated against mammalian heart and chicken limb muscles. The similarity of the fast-twitch MHC of bag2 and chain fibers and the slow-tonic MHC of bag1 and bag2 fibers to the MHC isoforms expressed in avian extrafusal fibers suggests that phylogenetically primitive MHCs might persist in intrafusal fibers. Data are discussed relative to the origin and regional regulation of MHC isoforms in intrafusal and extrafusal fibers of rat hindlimb muscles.

scholarly journals Revisiting the peculiar regional distribution of muscle fiber types in rat Sternomastoid Muscle

2018 ◽  
Vol 28 (1) ◽  
Author(s):  
Barbara Ravara ◽  
Valerio Gobbo ◽  
Damiana Incendi ◽  
Andrea Porzionato ◽  
Veronica Macchi ◽  
...  
Keyword(s):  
Cross Sections ◽  
Muscle Fibers ◽  
Regional Distribution ◽  
Absolute Number ◽  
Muscle Fiber Types ◽  
Fiber Types ◽  
Types Of Muscle Fibers ◽  
Deep Region ◽  
Whole Muscle

The sternomastoid (SM) muscle in rodents is known to have a peculiar distribution of fiber types with a steep gradient from surface to deep region. We here further characterize this peculiar regional distribution by quantitative histochemical morphometrys. In Hematoxylin-Eosin (H-E) stained transverse cryosections harvested in the medial portion of the muscle we counted around 10.000 myofibers with a mean diameter of 51.3±12.6 (μm). Cryisections of the SM stained by SDH reaction clearly show two distinct regions, toward the deep surface of the muscle a 40% area that contains packed SDH-positive myofibers, while the remaining area of the SM toward the external surface presents a more checker-board appearance. On the other hand, in the deep region of SM type 1 (slow contracting) muscle fibers, caracterized by positive acidic ATPase pH 4.35 reaction, are only the 24.5% of the fibers in the deep area of SM muscles, being restricted to the deepest region. The 75.5% of the myofibers in the deep region are of the fast contracting types (either 48.4% 2A, SDH –positive fibers or 27.1% 2B, SDH-negative fibers, respectively). As expected the 2B muscle fibers, acidic ATPase pH 4.3-negative and SDH-negative, present the largest size, while Type 1 fibers, acidic ATPase pH 4.3-positive and SDH-positive, present the smallest size in rat SM muscle. Based on present and previous observations, comparison of change in absolute number and/or percentage of the fiber types in any experimental model of muscle atrophy/hypertrophy/plasticity/pathology /recovery in the rat SM, and possibly of all mammals, will ask for morphometry of the whole muscle cross-sections, muscle sampling by bioptic approches will provide only comparable data on the size of the different types of muscle fibers.

scholarly journals Supraspinatus and deltoid muscle fiber diversity in rotator cuff tear conditions

2019 ◽  
Author(s):  
Morten Kjaer Ravn ◽  
Trine Ivarsen Ostergaard ◽  
Henrik Daa Schroeder ◽  
Jens Randel Nyengaard ◽  
Kate Lykke Lambertsen ◽  
...  
Keyword(s):  
Rotator Cuff ◽  
Muscle Fiber ◽  
Muscle Fibers ◽  
Deltoid Muscle ◽  
Cell Types ◽  
Fiber Types ◽  
Musculotendinous Junction ◽  
Fiber Atrophy

Abstract Background: Rotator cuff (RC) tears are associated with RC muscle atrophy and changes in composition that are crucial to the prognosis of RC repair. The aim of this study was to characterize muscle fiber composition in the supraspinatus (SS) muscle under tear conditions. Methods: Muscle biopsies were obtained from 21 patients undergoing surgery for RC tendon tear. Biopsies were obtained from the musculotendinous junction of the SS muscle and control biopsies were harvested from the deltoid muscle (DT). Biopsies were immunohistochemically processed for detection of type 1 (slow type) and type 2 (fast type) fibers and analyzed using unbiased, stereological principles. We counted the total numbers of type 1 and 2 muscle fibers/mm 2 and fiber diameter was used to estimate muscle fiber atrophy and hypertrophy. Results: We found significantly more type 2 cells/mm 2 in the SS compared to the DT (p<0.01). In addition, we found a significantly higher fraction of type 1 fibers than type 2 fibers in the DT (p<0.01), whereas both fiber types were equally present in the SS. The diameters of SS cells were generally smaller than those of DT cells. Atrophy of especially SS type 2 fibers was also demonstrated. Fiber atrophy was more pronounced in men than women. Discussion: The changes in the composition of SS muscle cell types suggest a shift from type 1 to type 2 muscle fibers and atrophy of both type 1 and 2 fibers. This composition indicates loss of endurance and rapid fatigue of the SS muscle under RC tear conditions.

scholarly journals Supplemental Material: Active faulting controls bedform development on a deep-water fan

2021 ◽  
Author(s):  
Vittorio Maselli ◽  
et al.
Keyword(s):  
Numerical Modeling ◽  
Cross Sections ◽  
Deep Water ◽  
Active Faulting ◽  
Additional Information ◽  
Sediment Waves ◽  
Salt Deposits

Additional information about the numerical modeling, bathymetric profiles, cross sections along type 1 and type 2 bedforms, a 3-D view of the study area, seafloor bathymetry and thickness map of post-salt deposits, and morphology of sediment waves seaward of the fan.<br>

scholarly journals Contraction-Induced Injury to Single Permeabilized Muscle Fibers from Normal and Congenitally-Clefted Goat Palates

2007 ◽  
Vol 44 (2) ◽  
pp. 216-222 ◽  
Author(s):  
Erik P. Rader ◽  
Paul S. Cederna ◽  
Jeffrey Weinzweig ◽  
Kip E. Panter ◽  
Deborah Yu ◽  
...  
Keyword(s):  
Fiber Type ◽  
Muscle Fibers ◽  
Fetal Head ◽  
Levator Veli Palatini ◽  
Lengthening Contraction ◽  
Velopharyngeal Incompetence ◽  
Chemically Induced ◽  
Initial Force

Objective: Levator veli palatini muscles from normal palates of adult humans and goats are predominantly slow oxidative (type 1) fibers. However, 85% of levator veli palatini fibers from cleft palates of adult goats are physiologically fast (type 2). This fiber composition difference between cleft and normal palates may have implications in palatal function. For limb muscles, type 2 muscle fibers are more susceptible to lengthening contraction-induced injury than are type 1 fibers. We tested the hypothesis that, compared with single permeabilized levator veli palatini muscle fibers from normal palates of adult goats, those from cleft palates are more susceptible to lengthening contraction-induced injury. Interventions: Congenital cleft palates were the result of chemically-induced decreased movement of the fetal head and tongue causing obstruction of palatal closure. Each muscle fiber was maximally activated and lengthened. Outcome Measures: Fiber type was determined by contractile properties and gel electrophoresis. Susceptibility to injury was assessed by measuring the decrease in maximum force following the lengthening contraction, expressed as a percentage of the initial force. Results: Compared with fibers from normal palates that were all type 1 and had force deficits of 23 ± 1%, fibers from cleft palates were all type 2 and sustained twofold greater deficits, 40 ± 1% (p = .001). Conclusion: Levator veli palatini muscles from cleft palates of goats contain predominantly type 2 fibers that are highly susceptible to lengthening contraction-induced injury. This finding may have implications regarding palatal function and the incidence of velopharyngeal incompetence.

scholarly journals Supplemental Material: Active faulting controls bedform development on a deep-water fan

2021 ◽  
Author(s):  
Vittorio Maselli ◽  
et al.
Keyword(s):  
Numerical Modeling ◽  
Cross Sections ◽  
Deep Water ◽  
Active Faulting ◽  
Additional Information ◽  
Sediment Waves ◽  
Salt Deposits

Additional information about the numerical modeling, bathymetric profiles, cross sections along type 1 and type 2 bedforms, a 3-D view of the study area, seafloor bathymetry and thickness map of post-salt deposits, and morphology of sediment waves seaward of the fan.<br>

Ultrastructure of wilt syndrome caused by Verticillium dahliae. VI. Interpretive problems in the study of vessel coatings and tyloses

1979 ◽  
Vol 57 (7) ◽  
pp. 795-821 ◽  
Author(s):  
Jane Robb ◽  
A. Smith ◽  
J. D. Brisson ◽  
Lloyd Busch
Keyword(s):  
Cross Sections ◽  
Verticillium Dahliae ◽  
Bulk Material ◽  
Accurate Identification ◽  
Coating Materials ◽  
Sem Observation ◽  
Coating Type ◽  
Type 3

When leaves of Verticillium dahliae infected chrysanthemums and sunflowers show symptoms, many of the xylem vessels in the petioles are occluded by tyloses or, partially, by vessel coating materials. Four different cytological techniques are used to study these occluding structures: (1) SEM observation of bulk material fixed in glutaraldehyde and OsO4; (2) TEM observation of thin, monitored cross sections fixed in glutaraldehyde and stained and stabilized with FeCl3; (3) TEM observation of bulk material fixed in glutaraldehyde–acrolein and OsO4; (4) SEM observation of bulk material fixed in glutaraldehyde and stabilized with FeCl3. Three different kinds of coating materials are described: (1) smooth coating (type 1), (2) fibrillar coating (type 2), and (3) bubbly coating (type 3). A possible fourth type of coating is tentatively described as irregular coating (type 4). It is concluded that accurate identification of tyloses and coating materials is impossible with currently used techniques. The interpretational problems encountered at the various levels of microscopy (i.e., LM, SEM, and TEM) are summarized.

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