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ABSTRACT: Ruptures of the rotator cuff tendons of the human shoulder are a common incidence and lead to functional impairment of the four muscles connected to the cuff, entailing profound changes of their cellular tissue composition. Most importantly, such tendon tears lead to atrophy, fatty degeneration and fibrosis of the corresponding muscles. The muscle most commonly affected with such changes is the M. supraspinatus. The present study uses biopsy samples from the supraspinatus muscle of 12 elderly patients and 6 controls to examine the rupture-induced muscle change at both the cellular and the intracellular (ultrastructural) levels. Amounts of fatty tissue, connective tissue and muscle were assessed by light microscopy-based morphometry and stereology. Stereology of electron micrographs was employed to determine volume densities of muscle fibre mitochondria, myofibrils and intracellular lipid. Results demonstrate that the supraspinatus muscles of patients with a massive rupture contain significantly higher amounts not only of fatty tissue but also of intracellular lipid than those of control subjects. These patients further exhibit a major decrease in relative amounts of myofibrils, thus confirming that change of intracellular composition is a major component of the observed muscle degeneration. The results contribute to establish the true spectrum of supraspinatus muscle damage in humans induced by tendon rupture.
Tissue and Cell 09/2009; 42(1):37-41. · 1.04 Impact Factor
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ABSTRACT: Muscle development in teleost embryos has been shown to depend on myogenic cell recruitment from the dermomyotome (DM). However, little is known as to the cellular mechanisms that account for myotome growth after the dissociation of the DM. Here we combine immunolabeling for cell-specific markers with quantitative analysis to determine the sources and patterns of activation of myogenic cells in pearlfish larvae. Results demonstrate that appearance of mitotically active myogenic precursors inside the myotome coincides with the dissociation of the DM. Such cells are preferentially aggregated within the posterior lateral fast muscle. We therefore propose a growth model in which a pool of proliferative DM-derived precursors transferred to the posterior lateral fast muscle functions as an important source of myogenic cell spread to carry forward stratified fast muscle hyperplasia. This indicates that postembryonic teleost muscle growth includes a cellular mechanism that has no direct equivalent in the amniotes.
Developmental Dynamics 09/2009; 238(9):2442-8. · 2.54 Impact Factor
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ABSTRACT: Muscle development in teleost embryos has been shown to depend on myogenic cell recruitment from the dermomyotome (DM). However, little is known as to the cellular mechanisms that account for myotome growth after the dissociation of the DM. Here we combine immunolabeling for cell-specific markers with quantitative analysis to determine the sources and patterns of activation of myogenic cells in pearlfish larvae. Results demonstrate that appearance of mitotically active myogenic precursors inside the myotome coincides with the dissociation of the DM. Such cells are preferentially aggregated within the posterior lateral fast muscle. We therefore propose a growth model in which a pool of proliferative DM-derived precursors transferred to the posterior lateral fast muscle functions as an important source of myogenic cell spread to carry forward stratified fast muscle hyperplasia. This indicates that postembryonic teleost muscle growth includes a cellular mechanism that has no direct equivalent in the amniotes. Developmental Dynamics 238:2442–2448, 2009. © 2009 Wiley-Liss, Inc.
Developmental Dynamics 08/2009; 238(9):2442 - 2448. · 2.54 Impact Factor
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ABSTRACT: The predominant source of myogenic cells in vertebrates is the dermomyotome (DM). In teleost fish, recent research has provided a useful but limited picture of how myogenic precursors originate from the DM and how they develop into muscle fibers. Here, we combine detailed morphological analysis with examination of molecular markers in trout to describe the cellular mechanisms by which the lateral fast muscle growth zone is created during second phase myogenesis. Results suggest that this occurs by lateral-to-medial immigration of myogenic cells de-epithelializing from the posterior DM lip. These cells then appear to stop proliferation and migrate anteriorly to finally differentiate into muscle fibres. This seems to be a continuation of the rotational cell movement that creates the teleost DM during early somite development. These findings suggest an evolutionary conserved role of the posterior DM lip in amniotes and fish.
Developmental Dynamics 11/2008; 237(11):3233-9. · 2.54 Impact Factor
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ABSTRACT: The predominant source of myogenic cells in vertebrates is the dermomyotome (DM). In teleost fish, recent research has provided a useful but limited picture of how myogenic precursors originate from the DM and how they develop into muscle fibers. Here, we combine detailed morphological analysis with examination of molecular markers in trout to describe the cellular mechanisms by which the lateral fast muscle growth zone is created during second phase myogenesis. Results suggest that this occurs by lateral-to-medial immigration of myogenic cells de-epithelializing from the posterior DM lip. These cells then appear to stop proliferation and migrate anteriorly to finally differentiate into muscle fibres. This seems to be a continuation of the rotational cell movement that creates the teleost DM during early somite development. These findings suggest an evolutionary conserved role of the posterior DM lip in amniotes and fish. Developmental Dynamics 237:3233–3239, 2008. © 2008 Wiley-Liss, Inc.
Developmental Dynamics 10/2008; 237(11):3233 - 3239. · 2.54 Impact Factor
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ABSTRACT: Muscle cell recruitment (hyperplasia) during myogenesis in the vertebrate embryo is known to occur in three consecutive phases. In teleost fish (including zebrafish), however, information on myogenic precursor cell activation is largely fragmentary, and comprehensive characterization of the myogenic phases has only been fully undertaken in a single slow-growing cyprinid species by examination of MEF2D expression. Here, we use molecular techniques to provide a comprehensive characterization of MyoD and Myogenin expression during myogenic cell activation in embryos and larvae of brown trout, a fast-growing salmonid with exceptionally large embryos. Results confirm the three-phase pattern, but also demonstrate that the second and third phases begin simultaneously and progress vigorously, which is different from the previously described consecutive activation of these phases. Furthermore, we suggest that Pax7 is expressed in myogenic progenitor cells that account for second- and third-phase myogenesis. These findings are discussed in relation to teleost myotome development and to teleost growth strategies.
Developmental Dynamics 05/2007; 236(4):1106-14. · 2.54 Impact Factor
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ABSTRACT: Present knowledge indicates that fibre recruitment (hyperplasia) in developing teleost fish occurs in three distinct phases. However, the origin and relationship of the myogenic precursors activated during the different phases remains unclear. Here, we address this issue using molecular techniques on embryos and larvae of pearlfish, a large cyprinid species. Results provide comprehensive molecular characterisation of cell recruitment over the three phases of myogenesis, identifying muscle types as they arise. Specifically, we show that the myogenic cells arising during 2nd phase myogenesis are clearly different from the myogenic cells arising during the 3rd phase and that the dermomyotome is a major source of myogenic cells driving 2nd phase hyperplasia. These findings are discussed in relation to their implications for the generality of vertebrate developmental patterns.
Developmental Dynamics 12/2006; 235(11):3132-43. · 2.54 Impact Factor
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ABSTRACT: Patterns of initial muscle formation are well documented for teleost fish. Here, attention is focused upon sturgeons, which arose close to the base of the actinopterygian radiation and whose early development has remained largely unresearched. We demonstrate that some features of muscle development are common to both groups of fish, the most important being the origin and form of migration of adaxial cells to establish the superficial slow fibre layer. This, together with information on initial innervation and capillarisation, strongly suggests a common basis for muscle developmental mechanisms among fish. An important feature that is different between sturgeons and teleosts is that sturgeons lack any cellular dorsal-ventral separation of the myotome that involves the insertion of muscle pioneer (MP)-like cells at the site of the future horizontal septum. This, and information from other fish and from sarcopterygians, permits the supposition that such MP-defined dorsal-ventral separation is a teleost apomorphism. These and other findings are discussed in relation to their significance for the evolution of fish muscle developmental patterns.
Anatomy and Embryology 09/2006; 211(4):311-22. · 1.42 Impact Factor
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ABSTRACT: Teleost fish are known to develop small populations of muscle fibres that are assumed to be tonic in nature although their contractile properties and many other characteristics remain unknown. Here we attempt to resolve some of the ambiguity and confusions surrounding the definition and functional role of tonic fibres in teleosts and provide new information on their ontogeny. We investigate the differentiation of tonic muscle fibres in three species of cyprinid fish using electron microscopy, histochemistry, immunohistochemistry and in situ hybridization. The fine structure of the fibres defined as tonic in the larvae used in this study complies with patterns known from studies in teleost adults. This allows formal definition of tonic fibres in cyprinid larvae. The tonic fibres may be recognized by a variety of features: (1) by their characteristic position along the medial confines of the red muscle insertion at the horizontal septum, (2) their fine structure, including solid clusters of irregularly cleaved myofibrils, thick and wavy Z-lines, and T-tubules at the A-band/I-band transitions, (3) their histochemical features, specifically weak but obvious staining for mATPase after alkaline preincubation, and lack of SDH activity in the more advanced larval stages, (4) their unique immunological properties, being the only fibre type in the myotome that reacts with a serum against chicken tonic myosin (anti- T2). Expression of tonic characters usually begins within a few fibres in the dorsal domain of the superficial red muscle insertion at the horizontal septum and hence involves a high degree of dorso-ventral polarity. The present evidence indicates that tonic fibres arise from separate myogenic stem cells rather than by transdifferentiation from existing red fibres. First appearance of tonic fibres during ontogeny correlates closely with the onset of free swimming and exogeneous feeding. We use this fact to argue that tonic fibres are probably a prerequisite for efficient locomotory control during prey capture, shoaling and predator avoidance.
Anatomy and Embryology 06/2002; 205(2):113-24. · 1.42 Impact Factor
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ABSTRACT: Inflamed oral mucosa biopsies from patients with thrush and high candidal density were observed in a transmission electron microscope (TEM) using ultra-histochemical staining with ruthenium red for glycocalyx visualization. Fimbriae comprising the glycocalyx and enabling yeast adhesion to epithelial cells were clearly visualized by ruthenium red. All internalized portions of the yeast walls were devoid of glycocalyx, indicating that the growing tips of the hyphae mechanically penetrated the host cells. The attachment of Candida occurred in two ways: by fimbria-mediated adhesion enabling colonization of the epithelial surface, and by invasion of the superficial epithelial cells via hyphae. As the interaction between adhesin receptors and adhesins stimulates the production of proinflammatory cytokines, Candida adhesion itself is assumed to induce mucosal inflammation.
Oral Microbiology and Immunology 03/2002; 17(1):60-4. · 2.81 Impact Factor
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ABSTRACT: The main muscle fiber types of fish axial muscle, namely red, white, intermediate, or pink, so-called tonic, red muscle rim, transitional zone, and scattered dorsal and ventral fibers, are described with respect to their location, origin, fine structure, and biochemical and functional characteristics. Ontogenic changes in structural and functional features are discussed, as well as interspecific variations. Red muscle fibers, the most aerobic fiber type, are characterized by high amounts of oxidative enzymes, mitochondria, lipid droplets, and capillaries. In white muscle fibers, metabolic economy is less important than maximum power output, therefore their characteristics emphasize their recruitment for burst-swimming activities. Intermediate muscle fiber, as their name suggets, are between red and white muscle fibers in a variety of their characteristics. The variety of these and other fiber types is described. A further focus of attention is the plasticity of muscle phenotype. Particularly, the factors that lead to adaptational changes in fish axial muscle (seasonal, temperature, oxygen tension, and exercise training) are discussed. Cold acclimation/acclimatization, hypoxic conditions, and endurance training demonstrate a general trend for transition to more aerobic fiber types and a more aerobic type of muscle.
Fish Physiology. 01/2001;
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ABSTRACT: The Straub tail reaction in mice is an S-shaped dorsiflexion of the mouse tail, long known as a sensitive and specific bioassay for morphine (CAS 57-27-2). It is based on a contraction of the sacro-coccygeal dorsalis muscles. In the case of morphine the reaction is thought to be induced by a long-lasting stimulation of the muscle's motor innervation at the level of the lumbosacral spinal cord. A similar reaction caused by epibatidine differs pharmacologically, because in this case the reaction can be specifically inhibited by the ganglionic blocking agent mecamylamine. This points to a site of action of epibatidine (CAS 140111-52-0) at the neuromuscular junction of the sacro-coccygeal dorsalis muscles and requires the presence of muscle fibres which react to depolarization by sustained contraction. The present study provides evidence of the existence of such fibres using histochemical and immunohistochemical methods.
Arzneimittel-Forschung 09/2000; 50(8):683-7. · 0.72 Impact Factor
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ABSTRACT: As yet, our understanding of teleost muscle development has relied upon interpretation of a variety of studies of a small number of different species, spanning the tropics to the North Atlantic, sea water to fresh water. The zebrafish Danio rerio has become the most widely used model species for laboratory-based investigations of the earliest steps of developing muscle architecture. The present pattern of teleost muscle formation is likely to provide a common basis for understanding the variety of mechanisms that control myogenesis, but is not yet tested for its applicability to fish from a wide variety of teleost taxa. Using examples from different areas of developmental research in fish, it is argued that a more flexible and dynamic scheme of muscle development needs to be envisaged. This would extend the present basic pattern to encompass expression of the full spectrum of ecological and evolutionary variation, particularly in relation to rate of muscle development and final morphology.
Journal of Fish Biology 11/1999; 55(sA):84 - 99. · 1.68 Impact Factor
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ABSTRACT: The debate about the pattern of muscle formation in teleost fish has recently been heightened in the literature. Here we examine superficial muscle development in the pearlfish, a cyprinid endemic to a small area of Central Europe, and uninfluenced by economic interest and breeding. Using light and electron microscopy, histochemistry and immunohistochemistry techniques, we report that: (1) Superficial fibre precursors originate close to the notochord, are part of the same cell population as the so-called muscle pioneer cells, and are transferred laterally to end up at the surface of the myotome. (2) Superficial fibre maturation is exceptionally rapid. Structural and enzymatic functionality is attained at a time when prospective deep fibres have not passed beyond the early myotube state. This strong contrast weakens as the embryo develops. (3) Apart from the muscle pioneers, the superficial fibres appear to be capable of functioning before they receive any direct innervation, implying that signals are transferred to these fibres via cell-to-cell junctions. We suggest that the capability of rapid superficial fibre maturation is a rather general feature among teleosts and may aid pre-hatch survival under a variable environment. Our results indicate that muscle formation in teleost fish may follow a common basic pattern that is open to considerable ontogenetic and phylogenetic modification in response to habitat conditions.
Anatomy and Embryology 07/1998; 197(6):485-96. · 1.42 Impact Factor
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ABSTRACT: The debate about the pattern of muscle formation in teleost fish has recently been heightened in the literature. Here we examine superficial muscle development in the pearlfish, a cyprinid endemic to a small area of Central Europe, and uninfluenced by economic interest and breeding. Using light and electron microscopy, histochemistry and immunohistochemistry techniques, we report that: (1) Superficial fibre precursors originate close to the notochord, are part of the same cell population as the so-called muscle pioneer cells, and are transferred laterally to end up at the surface of the myotome. (2) Superficial fibre maturation is exceptionally rapid. Structural and enzymatic functionality is attained at a time when prospective deep fibres have not passed beyond the early myotube state. This strong contrast weakens as the embryo develops. (3) Apart from the muscle pioneers, the superficial fibres appear to be capable of functioning before they receive any direct innervation, implying that signals are transferred to these fibres via cell-to-cell junctions. We suggest that the capability of rapid superficial fibre maturation is a rather general feature among teleosts and may aid pre-hatch survival under a variable environment. Our results indicate that muscle formation in teleost fish may follow a common basic pattern that is open to considerable ontogenetic and phylogenetic modification in response to habitat conditions.
Anatomy and Embryology 04/1998; 197(6):485-496. · 1.42 Impact Factor
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ABSTRACT: This study is based on transmission electron microscopic (TEM) investigations of deep (fast, 'white') teleost fish muscle proliferation in early developmental stages of three European cyprinid species and the rainbow trout. Our fine structural findings provide evidence that early myotomal growth in these animals may utilize different mechanisms that are activated in close succession during early life history. First, initial enlargement of the deep muscle bulk in the embryo seems to be due to hypertrophy of the somite-cell derived stock of muscle fibres. Second, we suggest that deep muscle growth becomes additionally powered by attachment of presumptive myogenic cells that originate from and proliferate within the adjacent mesenchymal tissue lining. Third, mesenchyme-derived muscle cell precursors are thought to enter the myotomes via the myosepta. After migration between the pre-established muscle fibres these cells may function as myosatellite cells, thus at least partly providing the stem cell population for subsequent rapid hyperplastic growth. Finally, there is evidence that presumptive deep muscle satellite cells also proliferate by mitotic division in situ. A similar process of myogenic cell migration and proliferation may foster intermediate fibre differentiation. The model of myogenic cell migration is discussed in view of in vitro and in vivo data on satellite cell migratory power and with respect to temperature-induced and species dependent differences. As for the latter, our results indicate that patterns of muscle differentiation may diverge between a fast growing salmonid species and a moderately growing cyprinid species of similar final size. The model is compatible with the well-established idea that teleost muscle growth may rely on different subclasses of myosatellite cells.
Anatomy and Embryology 01/1997; 194(6):569-79. · 1.42 Impact Factor
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ABSTRACT: The somitic compartment that gives rise to trunk muscle and dermis in amniotes is an epithelial sheet on the external surface of the somite, and is known as the dermomyotome. However, despite its central role in the development of the trunk and limbs, the evolutionary history of the dermomyotome and its role in nonamniotes is poorly understood. We have tested whether a tissue with the morphological and molecular characteristics of a dermomyotome exists in nonamniotes. We show that representatives of the agnathans and of all major clades of gnathostomes each have a layer of cells on the surface of the somite, external to the embryonic myotome. These external cells do not show any signs of terminal myogenic or dermogenic differentiation. Moreover, in the embryos of bony fishes as diverse as sturgeons (Chondrostei) and zebrafish (Teleostei) this layer of cells expresses the pax3 and pax7 genes that mark myogenic precursors. Some of the pax7-expressing cells also express the differentiation-promoting myogenic regulatory factor Myogenin and appear to enter into the myotome. We therefore suggest that the dermomyotome is an ancient and conserved structure that evolved prior to the last common ancestor of all vertebrates. The identification of a dermomyotome in fish makes it possible to apply the powerful cellular and genetic approaches available in zebrafish to the understanding of this key developmental structure.
Evolution & Development 8(1):101-10. · 2.47 Impact Factor
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ABSTRACT: Ruptures of the rotator cuff tendons of the human shoulder are a common incidence and lead to functional impairment of the four muscles connected to the cuff, entailing profound changes of their cellular tissue composition. Most importantly, such tendon tears lead to atrophy, fatty degeneration and fibrosis of the corresponding muscles. The muscle most commonly affected with such changes is the M. supraspinatus. The present study uses biopsy samples from the supraspinatus muscle of 12 elderly patients and 6 controls to examine the rupture-induced muscle change at both the cellular and the intracellular (ultrastructural) levels. Amounts of fatty tissue, connective tissue and muscle were assessed by light microscopy-based morphometry and stereology. Stereology of electron micrographs was employed to determine volume densities of muscle fibre mitochondria, myofibrils and intracellular lipid. Results demonstrate that the supraspinatus muscles of patients with a massive rupture contain significantly higher amounts not only of fatty tissue but also of intracellular lipid than those of control subjects. These patients further exhibit a major decrease in relative amounts of myofibrils, thus confirming that change of intracellular composition is a major component of the observed muscle degeneration. The results contribute to establish the true spectrum of supraspinatus muscle damage in humans induced by tendon rupture.
Tissue and Cell.
